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Sample records for ae source mechanisms

  1. AE Source Orientation by Plate Wave Analysis

    NASA Technical Reports Server (NTRS)

    Gorman, Michael R.; Prosser, William H.

    1991-01-01

    Lead breaks (Hsu-Neilsen source) were used to generate simulated acoustic emission signals in an aluminum plate at angles of 0, 30, 60, and 90 degrees with respect to the plane of the plate. This was accomplished by breaking the lead on slots cut into the plate at the respective angles. The out-of-plane and in-plane displacement components of the resulting signals were detected by broad band transducers and digitized. Analysis of the waveforms showed them to consist of the extensional and flexural plate modes. The amplitude of both components of the two modes was dependent on the source orientation angle. This suggests that plate wave analysis may be used to determine the source orientation of acoustic emission sources.

  2. A Procedure to Determine the Optimal Sensor Positions for Locating AE Sources in Rock Samples

    NASA Astrophysics Data System (ADS)

    Duca, S.; Occhiena, C.; Sambuelli, L.

    2015-03-01

    Within a research work aimed to better understand frost weathering mechanisms of rocks, laboratory tests have been designed to specifically assess a theoretical model of crack propagation due to ice segregation process in water-saturated and thermally microcracked cubic samples of Arolla gneiss. As the formation and growth of microcracks during freezing tests on rock material is accompanied by a sudden release of stored elastic energy, the propagation of elastic waves can be detected, at the laboratory scale, by acoustic emission (AE) sensors. The AE receiver array geometry is a sensitive factor influencing source location errors, for it can greatly amplify the effect of small measurement errors. Despite the large literature on the AE source location, little attention, to our knowledge, has been paid to the description of the experimental design phase. As a consequence, the criteria for sensor positioning are often not declared and not related to location accuracy. In the present paper, a tool for the identification of the optimal sensor position on a cubic shape rock specimen is presented. The optimal receiver configuration is chosen by studying the condition numbers of each of the kernel matrices, used for inverting the arrival time and finding the source location, and obtained for properly selected combinations between sensors and sources positions.

  3. Fracture Analysis Based on Quantitative Evaluation of Microcracking in Ceramics Using AE Source Characterization

    NASA Astrophysics Data System (ADS)

    Wakayama, Shuichi; Ishiwata, Kohei

    Quantitative detection of microcracks during fracture process of alumina was carried out by AE source characterization, which enables the quantitative characterization of the size, nucleation velocity and fracture mode, as well as nucleation time and location of individual microcracks. Fracture toughness tests of SENB specimens of two types of alumina with different grain size and purity were carried out in air and water. AE signals emitted from microcrackings were detected by piezoelectric transducers. The combined response function of the specimen and measurement system was experimentally determined using a pencil lead breaking as a simulated source. Then AE source function which describes the nature of microcrack nucleation was determined by the inverse calculation using obtained response function and detected signal. Consequently, it was clarified that the size of microcrack in water was larger than that in air for both alumina and larger microcracks nucleated in water resulted in the degradation of fracture resistance.

  4. Drug-resistant molecular mechanism of CRF01_AE HIV-1 protease due to V82F mutation

    NASA Astrophysics Data System (ADS)

    Liu, Xiaoqing; Xiu, Zhilong; Hao, Ce

    2009-05-01

    Human immunodeficiency virus type 1 protease (HIV-1 PR) is one of the major targets of anti-AIDS drug discovery. The circulating recombinant form 01 A/E (CRF01_AE, abbreviated AE) subtype is one of the most common HIV-1 subtypes, which is infecting more humans and is expanding rapidly throughout the world. It is, therefore, necessary to develop inhibitors against subtype AE HIV-1 PR. In this work, we have performed computer simulation of subtype AE HIV-1 PR with the drugs lopinavir (LPV) and nelfinavir (NFV), and examined the mechanism of resistance of the V82F mutation of this protease against LPV both structurally and energetically. The V82F mutation at the active site results in a conformational change of 79's loop region and displacement of LPV from its proper binding site, and these changes lead to rotation of the side-chains of residues D25 and I50'. Consequently, the conformation of the binding cavity is deformed asymmetrically and some interactions between PR and LPV are destroyed. Additionally, by comparing the interactive mechanisms of LPV and NFV with HIV-1 PR we discovered that the presence of a dodecahydroisoquinoline ring at the P1' subsite, a [2-(2,6-dimethylphenoxy)acetyl]amino group at the P2' subsite, and an N2 atom at the P2 subsite could improve the binding affinity of the drug with AE HIV-1 PR. These findings are helpful for promising drug design.

  5. Waveform Analysis of AE in Composites

    NASA Technical Reports Server (NTRS)

    Prosser, William H.

    1998-01-01

    Advanced, waveform based acoustic emission (AE) techniques have been developed to evaluate damage mechanisms in the testing of composite materials. This approach, more recently referred to as Modal AE, provides an enhanced capability to discriminate and eliminate noise signals from those generated by damage mechanisms. Much more precise source location can also be obtained in comparison to conventional, threshold crossing arrival time determination techniques. Two successful examples of the application of Modal AE are presented in this work. In the first, the initiation of transverse matrix cracking in cross-ply, tensile coupons was monitored. In these tests, it was documented that the same source mechanism, matrix cracking, can produce widely different AE signal amplitudes dependent on laminate stacking sequence and thickness. These results, taken together with well known propagation effects of attenuation and dispersion of AE signals in composite laminates, cast further doubt on the validity of simple amplitude or amplitude distribution analysis for AE source determination. For the second example, delamination propagation in composite ring specimens was monitored. Pressurization of these composite rings is used to simulate the stresses in a composite rocket motor case. AE signals from delamination propagation were characterized by large amplitude flexural plate mode components which have long signal durations because of the large dispersion of this mode.

  6. AE 941.

    PubMed

    2004-01-01

    AE 941 [Arthrovas, Neoretna, Psovascar] is shark cartilage extract that inhibits angiogenesis. AE 941 acts by blocking the two main pathways that contribute to the process of angiogenesis, matrix metalloproteases and the vascular endothelial growth factor signalling pathway. When initial development of AE 941 was being conducted, AEterna assigned the various indications different trademarks. Neovastat was used for oncology, Psovascar was used for dermatology, Neoretna was used for ophthalmology and Arthrovas was used for rheumatology. However, it is unclear if these trademarks will be used in the future and AEterna appears to only be using the Neovastat trademark in its current publications regardless of the indication. AEterna Laboratories signed commercialisation agreements with Grupo Ferrer Internacional SA of Spain and Medac GmbH of Germany in February 2001. Under the terms of the agreement, AEterna has granted exclusive commercialisation and distribution rights to AE 941 in oncology to Grupo Ferrer Internacional for the Southern European countries of France, Belgium, Spain, Greece, Portugal and Italy. It also has rights in Central and South America. Medac GmbH will have marketing rights in Germany, the UK, Scandinavia, Switzerland, Austria, Ireland, the Netherlands and Eastern Europe. In October 2002, AEterna Laboratories announced that it had signed an agreement with Australian healthcare products and services company Mayne Group for marketing AE 941 (as Neovastat) in Australia, New Zealand, Canada and Mexico. In March 2003, AEterna Laboratories announced it has signed an agreement with Korean based LG Life Sciences Ltd for marketing AE 941 (as Neovastat) in South Korea. The agreement provides AEterna with upfront and milestone payments, as well as a return on manufacturing and sales of AE 941. AEterna Laboratories had granted Alcon Laboratories an exclusive worldwide licence for AE 941 for ophthalmic products. However, this licence has been terminated. In

  7. Sources and characteristics of acoustic emissions from mechanically stressed geologic granular media — A review

    NASA Astrophysics Data System (ADS)

    Michlmayr, Gernot; Cohen, Denis; Or, Dani

    2012-05-01

    The formation of cracks and emergence of shearing planes and other modes of rapid macroscopic failure in geologic granular media involve numerous grain scale mechanical interactions often generating high frequency (kHz) elastic waves, referred to as acoustic emissions (AE). These acoustic signals have been used primarily for monitoring and characterizing fatigue and progressive failure in engineered systems, with only a few applications concerning geologic granular media reported in the literature. Similar to the monitoring of seismic events preceding an earthquake, AE may offer a means for non-invasive, in-situ, assessment of mechanical precursors associated with imminent landslides or other types of rapid mass movements (debris flows, rock falls, snow avalanches, glacier stick-slip events). Despite diverse applications and potential usefulness, a systematic description of the AE method and its relevance to mechanical processes in Earth sciences is lacking. This review is aimed at providing a sound foundation for linking observed AE with various micro-mechanical failure events in geologic granular materials, not only for monitoring of triggering events preceding mass mobilization, but also as a non-invasive tool in its own right for probing the rich spectrum of mechanical processes at scales ranging from a single grain to a hillslope. We review first studies reporting use of AE for monitoring of failure in various geologic materials, and describe AE generating source mechanisms in mechanically stressed geologic media (e.g., frictional sliding, micro-crackling, particle collisions, rupture of water bridges, etc.) including AE statistical features, such as frequency content and occurrence probabilities. We summarize available AE sensors and measurement principles. The high sampling rates of advanced AE systems enable detection of numerous discrete failure events within a volume and thus provide access to statistical descriptions of progressive collapse of systems

  8. Acoustic emission monitoring of tensile testing of corroded and un-corroded clad aluminum 2024-T3 and characterization of effects of corrosion on AE source events and material tensile properties

    NASA Astrophysics Data System (ADS)

    Okafor, A. Chukwujekwu; Natarajan, Shridhar

    2014-02-01

    Corrosion damage affects structural integrity and deteriorates material properties of aluminum alloys in aircraft structures. Acoustic Emission (AE) is an effective nondestructive evaluation (NDE) technique for monitoring such damages and predicting failure in large structures of an aircraft. For successful interpretation of data from AE monitoring, sources of AE and factors affecting it need to be identified. This paper presents results of AE monitoring of tensile testing of corroded and un-corroded clad Aluminum 2024-T3 test specimens, and characterization of the effects of strain-rate and corrosion damage on material tensile properties and AE source events. Effect of corrosion was studied by inducing corrosion in the test specimens by accelerated corrosion testing in a Q-Fog accelerated corrosion chamber for 12 weeks. Eight (8) masked dog-bone shaped specimens were placed in the accelerated corrosion chamber at the beginning of the test. Two (2) dog-bone shaped specimens were removed from the corrosion chamber after exposure time of 3, 6, 9, and 12 weeks respectively, and subjected to tension testing till specimen failure along with AE monitoring, as well as two (2) reference samples not exposed to corrosion. Material tensile properties (yield strength, ultimate tensile strength, toughness, and elongation) obtained from tension test and AE parameters obtained from AE monitoring were analyzed and characterized. AE parameters increase with increase in exposure period of the specimens in the corrosive environment. Aluminum 2024-T3 is an acoustically silent material during tensile deformation without any damage. Acoustic emission events increase with increase of corrosion damage and with increase in strain rate above a certain value. Thus AE is suitable for structural health monitoring of corrosion damage. Ultimate tensile strength, toughness and elongation values decrease with increase of exposure period in corrosion chamber.

  9. Source mechanism of volcanic tremor

    SciTech Connect

    Ferrick, M.G.; Qamar, A.; St. Lawrence, W.F.

    1982-10-10

    Low-frequency (<10 Hz) volcanic earthquakes originate at a wide range of depths and occur before, during, and after magmatic eruptions. The characteristics of these earthquakes suggest that they are not typical tectonic events. Physically analogous processes occur in hydraulic fracturing of rock formations, low-frequency icequakes in temperate glaciers, and autoresonance in hydroelectric power stations. We propose that unsteady fluid flow in volcanic conduits is the common source mechanism of low-frequency volcanic earthquakes (tremor). The fluid dynamic source mechanism explains low-frequency earthquakes of arbitrary duration, magnitude, and depth of origin, as unsteady flow is independent of physical properties of the fluid and conduit. Fluid transients occur in both low-viscosity gases and high-viscosity liquids. A fluid transient analysis can be formulated as generally as is warranted by knowledge of the composition and physical properties of the fluid, material properties, geometry and roughness of the conduit, and boundary conditions. To demonstrate the analytical potential of the fluid dynamic theory, we consider a single-phase fluid, a melt of Mount Hood andesite at 1250/sup 0/C, in which significant pressure and velocity variations occur only in the longitudinal direction. Further simplification of the conservation of mass and momentum equations presents an eigenvalue problem that is solved to determine the natural frequencies and associated damping of flow and pressure oscillations.

  10. AE Recorder Characteristics and Development.

    SciTech Connect

    Partridge, Michael E.; Curtis, Shane Keawe; McGrogan, David Paul

    2016-11-01

    The Anomalous Environment Recorder (AE Recorder) provides a robust data recording capability for multiple high-shock applications including earth penetrators. The AE Recorder, packaged as a 2.4" di ameter cylinder 3" tall, acquires 12 accelerometer, 2 auxiliary, and 6 discrete signal channels at 250k samples / second. Recording depth is 213 seconds plus 75ms of pre-trigger data. The mechanical, electrical, and firmware are described as well as support electro nics designed for the first use of the recorder.

  11. A scaling relationship between AE and natural earthquakes

    NASA Astrophysics Data System (ADS)

    Yoshimitsu, N.; Kawakata, H.; Takahashi, N.

    2013-12-01

    Micro fracture which occurs during rock fracture experiments are called acoustic emission (AE), and it help us to understand detailed processes of fault growth. However, it was unclear whether AE can be considered as a small earthquake or not. Usually, the seismic moment and the corner frequency are used for characterizing source property. It has been reported that the seismic moment is inversely proportional to the cube of corner frequency for natural earthquakes (with magnitude higher than ~ -4). In this study, we examine continuity of this relationship toward smaller magnitude of AE (around magnitude -8), estimating the source parameters of AE. Previously, it was impossible to record AE waveforms by broadband transducers under tri-axial conditions due to lack of pressure seal mechanism. Here we achieved protection of broadband transducers to use them under high pressure environments. This achievement enabled us to do spectral analysis of AE. At the same time, we also achieved multi-channel continuous recording with a high sampling rate, so as not to miss some events smaller than threshold or hide some events behind the mask times by triggered recording. We prepared a cylindrical Westerly granite sample, 50 mm in diameter and 100 mm in height. Sealed nine broadband transducers (sensitive range; 100 kHz - 2000 kHz) were attached on the sample surface. High sampling recording as 20 MS/s per channel was continued, during tri-axial loading (confining pressure: 10 MPa) which was continued to be controlled even after the peak strength. More than 6000 hypocenters were estimated from all pick data during the experiment. We clustered events around the peak strength, so that their differences of hypocenter locations were shorter than 2 mm and their cross correlation values for more than four channels were higher than 0.8. Then, we analyzed two of the largest clusters. After calibrating transducer response, we obtained displacement spectra for S waves, and estimated their

  12. Effects of Variations in Salt-Spray Conditions on the Corrosion Mechanisms of an AE44 Magnesium Alloy

    DOE PAGES

    Martin, Holly J.; Horstemeyer, M. F.; Wang, Paul T.

    2010-01-01

    The understanding of how corrosion affects magnesium alloys is of utmost importance as the automotive and aerospace industries have become interested in the use of these lightweight alloys. However, the standardized salt-spray test does not produce adequate corrosion results when compared with field data, due to the lack of multiple exposure environments. This research explored four test combinations through three sets of cycles to determine how the corrosion mechanisms of pitting, intergranular corrosion, and general corrosion were affected by the environment. Of the four test combinations, Humidity-Drying was the least corrosive, while the most corrosive test condition was Salt Spray-Humidity-Drying.more » The differences in corrosivity of the test conditions are due to the various reactions needed to cause corrosion, including the presence of chloride ions to cause pit nucleation, the presence of humidity to cause galvanic corrosion, and the drying phase which trapped chloride ions beneath the corrosion by-products.« less

  13. [Anticonvulsant and forced swim anti-immobility effects of tetrahydro-N, N-dimethyl-2,2-diphenyl-3-furanemethanamine (AE37): common action mechanism?].

    PubMed

    Vamvakidès, A

    2002-03-01

    Tetrahydro-N, N-dimethyl-2, 2-diphenyl-3-furanemethanamine (AE 37) is a newly synthesized anticonvulsant drug efficient against electrogenic (maximal electroshock: MES) or pentetrazole (PTZ) induced tonic convulsions of mice. It also antagonizes the immobility of adult or aged mice in the forced swim test (FST), which is used to detect antidepressive properties. Neurochemical changes induced by AE37 (antagonistic action on the sodium channel currents and on the receptors sensitive to N-methyl-D-aspartic acid) could generate the aforementioned pharmacological properties, whereas the partial agonistic action of AE 37 on the brain muscarinic receptors seems to confer to this drug characteristics of third generation antiepileptic.

  14. Waste tank deflagration source generation mechanisms

    SciTech Connect

    Paddleford, D.F.; Thomas, J.K.

    1995-07-01

    This paper describes the models employed and analyses performed to estimate the source terms which would result from deflagrations in waste storage and processing tanks at the Savannah River Site (SRS). It should be noted that SRS waste tank deflagrations are very low probability events. The three main source generation mechanisms associated with waste tank deflagrations are: (1) entrainment from the liquid surface, (2) vaporization from the liquid surface, and (3) solids fire ignited as a result of the deflagration. The results of this work show that entrainment would be the dominant source term generation mode for cases where the liquid waste solution level is near the vent path. Vaporization would be the dominant mode for cases where the liquid level is lower. The maximum vaporization source term is approximately an order of magnitude less than that maximum entrainment source term. The source term associated with a solids fire would be insignificant in comparison.

  15. AE-941 (AEterna).

    PubMed

    Dredge, Keith

    2004-06-01

    AEterna is developing AE-941, an angiogenesis inhibitor derived from the ultrafiltration of liquid shark cartilage, with matrix metalloprotease (MMP)-2, MMP-9 and vascular endothelial growth factor inhibitory properties, for the potential treatment of non-small-cell lung cancer.

  16. AE3D

    SciTech Connect

    Spong, Donald A

    2016-06-20

    AE3D solves for the shear Alfven eigenmodes and eigenfrequencies in a torodal magnetic fusion confinement device. The configuration can be either 2D (e.g. tokamak, reversed field pinch) or 3D (e.g. stellarator, helical reversed field pinch, tokamak with ripple). The equations solved are based on a reduced MHD model and sound wave coupling effects are not currently included.

  17. Applications of Advanced, Waveform Based AE Techniques for Testing Composite Materials

    NASA Technical Reports Server (NTRS)

    Prosser, William H.

    1996-01-01

    Advanced, waveform based acoustic emission (AE) techniques have been previously used to evaluate damage progression in laboratory tests of composite coupons. In these tests, broad band, high fidelity acoustic sensors were used to detect signals which were then digitized and stored for analysis. Analysis techniques were based on plate mode wave propagation characteristics. This approach, more recently referred to as Modal AE, provides an enhanced capability to discriminate and eliminate noise signals from those generated by damage mechanisms. This technique also allows much more precise source location than conventional, threshold crossing arrival time determination techniques. To apply Modal AE concepts to the interpretation of AE on larger composite structures, the effects of wave propagation over larger distances and through structural complexities must be well characterized and understood. In this research, measurements were made of the attenuation of the extensional and flexural plate mode components of broad band simulated AE signals in large composite panels. As these materials have applications in a cryogenic environment, the effects of cryogenic insulation on the attenuation of plate mode AE signals were also documented.

  18. Clinical epidemiology of human AE in Europe.

    PubMed

    Vuitton, D A; Demonmerot, F; Knapp, J; Richou, C; Grenouillet, F; Chauchet, A; Vuitton, L; Bresson-Hadni, S; Millon, L

    2015-10-30

    This review gives a critical update of the situation regarding alveolar echinococcosis (AE) in Europe in humans, based on existing publications and on findings of national and European surveillance systems. All sources point to an increase in human cases of AE in the "historic endemic areas" of Europe, namely Germany, Switzerland, Austria and France and to the emergence of human cases in countries where the disease had never been recognised until the end of the 20th century, especially in central-eastern and Baltic countries. Both increase and emergence could be only due to methodological biases; this point is discussed in the review. One explanation may be given by changes in the animal reservoir of the parasite, Echinococcus multilocularis (increase in the global population of foxes in Europe and its urbanisation, as well as a possible increased involvement of pet animals as definitive infectious hosts). The review also focuses onto 2 more original approaches: (1) how changes in therapeutic attitudes toward malignant and chronic inflammatory diseases may affect the epidemiology of AE in the future in Europe, since a recent survey of such cases in France showed the emergence of AE in patients with immune suppression since the beginning of the 21st century; (2) how setting a network of referral centres in Europe based on common studies on the care management of patients might contribute to a better knowledge of AE epidemiology in the future.

  19. Time-frequency Analyses of AE Signals in YBCO Superconductors

    NASA Astrophysics Data System (ADS)

    Nanato, N.; Takemoto, N.

    AE (Acoustic Emission) measurements are well known methods to detect mechanical signals from superconducting coil The mechanical signals could be generated by micro cracks of epoxy resins, the motion of superconductors and the thermal expansion of superconductors, which were generated before and/or after a quench. We have presented a time-frequency visualization of AE signals as a method to detect the quench. We can detect very small AE signals regardless of lectromagnetic noises and can find the time of the AE occurrence and the frequency bands of AE signals by using this method. Recently it has been presented that YBCO superconductors are delaminated and degraded by a transverse tensile stress. The delamination is accompanied with AE signals. Also, it is known that amplitudes and frequency bands of AE signals vary with causes of AE occurrence. In this paper, we present time-frequency analyses of AE signa s caused by the delamination of a YBCO superconductor and the micro of epoxy resins.

  20. (abstract) Airborne Emission Spectrometer (AES)

    NASA Technical Reports Server (NTRS)

    Beer, Reinhard

    1994-01-01

    AES is a low-cost analog of the TES downlooking modes. Because AES operates at ambient temperature, limb-viewing is not possible. The first flight of AES took place in April 1994 on the NASA P3B aircraft out of Wallops Island, VA. While planned as an engineering test flight, spectra were successfully acquired both over the Atlantic Ocean and the area of the Great Dismal Swamp on the Virginia-North Carolina border. At this writing (July 1994), a second series of flights on the NASA DC8 aircraft out of Ames RC,CA is in progress. By the time of the workshop, a third series using the NASA C130 should have been accomplished.

  1. Dream sources, associative mechanisms, and temporal dimension.

    PubMed

    Cavallero, C

    1987-02-01

    Using the technique of free association in an experimental setting, this author and colleagues previously found differences in the quality of memory traces involved in the production of REM and sleep onset (SO) dreams. The present study aims to answer two questions raised by those results: (a) Must the associative session be temporally contiguous to the dream production to gain access to the sources of the dream? (b) Are the differences between SO and REM associations due only to differences in structure and content of the two types of dream reports? Free associations with the same dream collected immediately after an experimental awakening were compared with those recalled 2 months later. A first group of results supports the hypothesis that free associations are sensitive to the proximity to the amount of dream production. A second group shows that the differences between SO and REM dreams noted in the previous research are not attributable to differences in formal characteristics of the report.

  2. Proposed mechanisms whereby the T3U, dialyzed fraction (%FT4) and antibody extracted (AE) T4 normalize binding protein effects in free T4 (FT4) assays do not explain the findings in monthyroidally ill (NTI) patients

    SciTech Connect

    Witherspoon, L.R.; Shuler, S.E.; Gilbert, S.

    1984-01-01

    Apparently falsely low FT4 results are observed in patients with NTI. FT4 estimates in NTI using some AE assays are lower than corresponding FTI. Both are lower than equilibrium dialysis (ED) results. These three approaches to FT4 estimation are similar - the T3U, %FT4 and %AE all are inversely related to TBG concentration. A FT4 estimate may be obtained by multiplying any of these x total T4 concentration. The mass of AE T4 may be quantitated by competitive binding, either after separation of AE T4 from serum (two step) or by employing a radiolabeled T4 analog recognized by the antibody but not by TBG. The authors made FT4 estimates in euthyroid patients with high, normal or low TBG concentrations; in hyper- and hypothyroid patients; and in NTI patients presumed euthyroid. Each approach produces similar results in euthyroid patients. The T3U and some AE assays display TBG dependence at TBG <10 and>50 ..mu..g/ml. In hyperthyroidism, the T3U is high, %FT4 normal or high, while the %AE is low. All FT4 results are high in hyperthyroidism. In hypothyroidism the T3U is low, %FT4 normal or low, while the %AE is high. All FT4 results are low in hypothyroidism. In NTI, the T3U is appropriate for the TBG concentration, %FT4 is often high and %AE is low. Furthermore, methods for quantifying the AE mass do not agree - index results are low, analog results lowers, such that %B/B is>100%, while the two step results are normal. The suggestion that the T3U, %FT4 and %AE all serve to normalize TBG effects in FT4 assays is inadequate. AE assays should be employed clinically with caution until the apparent anomalies, especially those seen in the analog systems, are explained.

  3. Role of NBCe1 and AE2 in Secretory Ameloblasts

    PubMed Central

    Paine, Michael L.; Snead, Malcolm L.; Wang, HongJun; Abuladze, Natalia; Pushkin, Alexander; Liu, Weixin; Kao, Li Yo; Wall, Susan M.; Kim, Young-Hee; Kurtz, Ira

    2008-01-01

    The H+/base transport processes that control the pH of the microenvironment adjacent to ameloblasts are not currently well understood. Mice null for the AE2 anion exchanger have abnormal enamel. In addition, patients with mutations in the electrogenic sodium bicarbonate cotransporter NBCe1 and mice lacking NBCe1 have enamel abnormalities. These observations suggest that AE2 and NBCe1 play important roles in amelogenesis. The present study aimed to understand the roles of AE2 and NBC1 in ameloblasts. The data showed that NBCe1 is expressed at the basolateral membrane of secretory ameloblasts, whereas AE2 is expressed at the apical membrane. Transcripts for AE2a and NBCe1-B were detected in RNA isolated from cultured ameloblast-like LS8 cells. Our data are the first evidence that AE2 and NBCe1 are expressed in ameloblasts in vivo in a polarized fashion thereby providing a mechanism for ameloblast transcellular bicarbonate secretion in the process of enamel formation and maturation. PMID:18362326

  4. Resolving source mechanisms of microseismic swarms induced by solution mining

    NASA Astrophysics Data System (ADS)

    Kinscher, J.; Cesca, S.; Bernard, P.; Contrucci, I.; Mangeney, A.; Piguet, J. P.; Bigarré, P.

    2016-07-01

    In order to improve our understanding of hazardous underground cavities, the development and collapse of a ˜200 m wide salt solution mining cavity was seismically monitored in the Lorraine basin in northeastern France. The microseismic events show a swarm-like behaviour, with clustering sequences lasting from seconds to days, and distinct spatiotemporal migration. Observed microseismic signals are interpreted as the result of detachment and block breakage processes occurring at the cavity roof. Body wave amplitude patterns indicated the presence of relatively stable source mechanisms, either associated with dip-slip and/or tensile faulting. Signal overlaps during swarm activity due to short interevent times, the high-frequency geophone recordings and the limited network station coverage often limit the application of classical source analysis techniques. To overcome these shortcomings, we investigated the source mechanisms through different procedures including modelling of observed and synthetic waveforms and amplitude spectra of some well-located events, as well as modelling of peak-to-peak amplitude ratios for the majority of the detected events. We extended the latter approach to infer the average source mechanism of many swarming events at once, using multiple events recorded at a single three component station. This methodology is applied here for the first time and represents a useful tool for source studies of seismic swarms and seismicity clusters. The results obtained with different methods are consistent and indicate that the source mechanisms for at least 50 per cent of the microseismic events are remarkably stable, with a predominant thrust faulting regime with faults similarly oriented, striking NW-SE and dipping around 35°-55°. This dominance of consistent source mechanisms might be related to the presence of a preferential direction of pre-existing crack or fault structures. As an interesting byproduct, we demonstrate, for the first time directly

  5. A high voltage power supply for the AE-C and D low energy electron experiment

    NASA Technical Reports Server (NTRS)

    Gillis, J. A.

    1974-01-01

    A description is given of the electrical and mechanical design and operation of high voltage power supplies for space flight use. The supply was used to generate the spiraltron high voltage for low energy electron experiment on AE-C and D. Two versions of the supply were designed and built; one design is referred to as the low power version (AE-C) and the other as the high power version (AE-D). Performance is discussed under all operating conditions.

  6. [Action mechanism of anticonvulsant and anti-immobility (forced swim) effects of 3', 4'-dihydro-N, N-dimethylspiro-[9H-fluorene-9, 2' (5'H) furane]-3'-methanamine (AE37F)].

    PubMed

    Vamvakidès, A; Antoniou, K; Daïfoti, Z

    2004-01-01

    AE37F, a new aminotetrahydrofuranic derivative, exhibited, at 10-30 mg/Kg (po) or 1-10 mg/Kg (ip), antagonism of tonic convulsions, induced by pentetrazole (130 mg/Kg, ip), and of forced swin immobility, in mice. At these doses AE37F induced a considerable (100-250%) increase of serotonin (5-HT) and its main metabolite, 5-hydroxyindolacetic acid (5-HIAA), in the rat nucleus reticularis pontis oralis (NRPO), antagonized by amantadine, which also increased 5-HT and 5-HIAA levels in the NRPO. It is suggested: a) that the anti-immobility effect of AE37F is related to its antimuscarinic properties, b) that the rate of 5-HT release in the NRPO, calculated here by a new approach (from the 5-HT and 5-HIAA brain levels) is increased by AE37F and decreased by amantadine, in the NRPO, c) that the anti-convulsant action, observed with AE37F, could be related to a NMDA-sigma mediated stimulation of serotoninergic, GABAergic and glycinergic brain neurones, antagonized by the NMDA-sigma inhibition induced by amantadine.

  7. AE mapping of engines for spatially located time series

    NASA Astrophysics Data System (ADS)

    Nivesrangsan, P.; Steel, J. A.; Reuben, R. L.

    2005-09-01

    This paper represents the first step towards using multiple acoustic emission (AE) sensors to produce spatially located time series signals for a running engine. By this it is meant the decomposition of a multi-source signal by acquiring it with an array of sensors and using source location to reconstitute the individual time series attributable to some or all of these signals. Internal combustion engines are a group of monitoring targets which would benefit from such an approach. A series of experiments has been carried out where AE from a standard source has been mapped for a large number of source-sensor pairs on a small diesel engine and on various cast iron blocks of simple geometry. The wave propagation on a typical diesel engine cylinder head or block is complex because of the heterogeneity of the cast iron and the complex geometry with variations in wall-thickness, boundaries and discontinuities. The AE signal distortion for a range of source-sensor pairs has been estimated using time-frequency analysis, and using a reference sensor placed close to the source. At this stage, the emphasis has been on determining a suitable processing scheme to recover a measure of the signal energy, which depends only on the distance of the source and not upon the path. Tentative recommendations are made on a suitable approach to sensor positioning and signal processing with reference to a limited set of data acquired from the running engine.

  8. Characterization of AE from fatigue crack growth in steel bridge components

    NASA Astrophysics Data System (ADS)

    Mejia, Felipe; Nemati, Navid; Nanni, Antonio

    2012-04-01

    Early detection of fatigue crack-growth in steel structures is an ongoing challenge. Furthermore, characterization of the different stages of the fatigue lifecycle using NDE techniques is particularly difficult. AE systems have been shown to serve as early damage detection mechanisms in bridge structures. This technology, however, is fraught with noise problems and complex datasets that are difficult to interpret. This paper attempts to design and implement a data mining scheme that can classify raw AE datasets into discrete clusters using an improved variant of the popular k-means clustering algorithm. The datasets are then augmented with the class label found during clustering, and a series of rules are inferred using a C4.5 decision tree classification algorithm. An implementation of the data mining scheme is coded in MATLAB®, with data from PAC® AE systems as the input. In order to validate this procedure, data from a pencil lead break test with a concurrent noise source is fed into the data mining program. Classification using the decision tree is compared to manual classification of the pencil lead break hits. The resulting decision tree is then applied to a similar dataset in order to evaluate the generality of the resulting rule sets. Once validated, the data mining program is applied to data belonging to a steel fatigue crack-growth test. Results of this classification are discussed, and possible improvements to the data mining scheme are suggested.

  9. Source mechanisms of a collapsing solution mine cavity

    NASA Astrophysics Data System (ADS)

    Lennart Kinscher, Jannes; Cesca, Simone; Bernard, Pascal; Contrucci, Isabelle; Mangeney, Anne; Piguet, Jack Pierre; Bigarre, Pascal

    2016-04-01

    The development and collapse of a ~200 m wide salt solution mining cavity was seismically monitored in the Lorraine basin in northeastern France. Seismic monitoring and other geophysical in situ measurements were part of a large multi-parameter research project founded by the research "group for the impact and safety of underground works" (GISOS), whose database is being integrated in the EPOS platform (European Plate Observing System). The recorded microseismic events (~ 50,000 in total) show a swarm-like behaviour, with clustering sequences lasting from seconds to days, and distinct spatiotemporal migration. The majority of swarming signals are likely related to detachment and block breakage processes, occurring at the cavity roof. Body wave amplitude patterns indicate the presence of relatively stable source mechanisms, either associated with dip-slip and/or tensile faulting. However, short inter-event times, the high frequency geophone recordings, and the limited network station coverage often limits the application of classical source analysis techniques. In order to deal with these shortcomings, we examined the source mechanisms through different procedures including modelling of observed and synthetic waveforms and amplitude spectra of some well located events, as well as modelling of peak-to-peak amplitude ratios for most of the detected events. The latter approach was used to infer the average source mechanism of many swarming events at once by using a single three component station. To our knowledge this approach is applied here for the first time and represents an useful tool for source studies of seismic swarms and seismicity clusters. The results of the different methods are consistent and show that at least 50 % of the microseismic events have remarkably stable source mechanisms, associated with similarly oriented thrust faults, striking NW-SE and dipping around 35-55°. Consistent source mechanisms are probably related to the presence of a

  10. Infrared observations of AE Aquarii

    NASA Technical Reports Server (NTRS)

    Tanzi, E. G.; Chincarini, G.; Tarenghi, M.

    1981-01-01

    Broadband infrared observations of the cataclysmic variable AE Aquarii are reported. The observations were obtained in the J, H, K and L filters with the InSb photometer attached to the 1-m telescope of the European Southern Observatory. The infrared energy distribution observed from 0.35 to 3.5 microns for phase 0.5 suggests a spectral type of K5 V for the secondary and a distance to the system of approximately 70 pc if an absolute magnitude of 7.3 is assumed. Monitoring of the flux at 2.2 microns reveals a variability with an amplitude of approximately 0.3 magnitude over one third of the orbital period, the nature of which is under investigation.

  11. Oxidative Stress in Intracerebral Hemorrhage: Sources, Mechanisms, and Therapeutic Targets

    PubMed Central

    Hu, Xin; Tao, Chuanyuan; Gan, Qi; Zheng, Jun; Li, Hao; You, Chao

    2016-01-01

    Intracerebral hemorrhage (ICH) is associated with the highest mortality and morbidity despite only constituting approximately 10–15% of all strokes. Complex underlying mechanisms consisting of cytotoxic, excitotoxic, and inflammatory effects of intraparenchymal blood are responsible for its highly damaging effects. Oxidative stress (OS) also plays an important role in brain injury after ICH but attracts less attention than other factors. Increasing evidence has demonstrated that the metabolite axis of hemoglobin-heme-iron is the key contributor to oxidative brain damage after ICH, although other factors, such as neuroinflammation and prooxidases, are involved. This review will discuss the sources, possible molecular mechanisms, and potential therapeutic targets of OS in ICH. PMID:26843907

  12. Chromosome isolation by flow sorting in Aegilops umbellulata and Ae. comosa and their allotetraploid hybrids Ae. biuncialis and Ae. geniculata.

    PubMed

    Molnár, István; Kubaláková, Marie; Šimková, Hana; Cseh, András; Molnár-Láng, Márta; Doležel, Jaroslav

    2011-01-01

    This study evaluates the potential of flow cytometry for chromosome sorting in two wild diploid wheats Aegilops umbellulata and Ae. comosa and their natural allotetraploid hybrids Ae. biuncialis and Ae. geniculata. Flow karyotypes obtained after the analysis of DAPI-stained chromosomes were characterized and content of chromosome peaks was determined. Peaks of chromosome 1U could be discriminated in flow karyotypes of Ae. umbellulata and Ae. biuncialis and the chromosome could be sorted with purities exceeding 95%. The remaining chromosomes formed composite peaks and could be sorted in groups of two to four. Twenty four wheat SSR markers were tested for their position on chromosomes of Ae. umbellulata and Ae. comosa using PCR on DNA amplified from flow-sorted chromosomes and genomic DNA of wheat-Ae. geniculata addition lines, respectively. Six SSR markers were located on particular Aegilops chromosomes using sorted chromosomes, thus confirming the usefulness of this approach for physical mapping. The SSR markers are suitable for marker assisted selection of wheat-Aegilops introgression lines. The results obtained in this work provide new opportunities for dissecting genomes of wild relatives of wheat with the aim to assist in alien gene transfer and discovery of novel genes for wheat improvement.

  13. Chromosome Isolation by Flow Sorting in Aegilops umbellulata and Ae. comosa and Their Allotetraploid Hybrids Ae. biuncialis and Ae. geniculata

    PubMed Central

    Molnár, István; Kubaláková, Marie; Šimková, Hana; Cseh, András; Molnár-Láng, Márta; Doležel, Jaroslav

    2011-01-01

    This study evaluates the potential of flow cytometry for chromosome sorting in two wild diploid wheats Aegilops umbellulata and Ae. comosa and their natural allotetraploid hybrids Ae. biuncialis and Ae. geniculata. Flow karyotypes obtained after the analysis of DAPI-stained chromosomes were characterized and content of chromosome peaks was determined. Peaks of chromosome 1U could be discriminated in flow karyotypes of Ae. umbellulata and Ae. biuncialis and the chromosome could be sorted with purities exceeding 95%. The remaining chromosomes formed composite peaks and could be sorted in groups of two to four. Twenty four wheat SSR markers were tested for their position on chromosomes of Ae. umbellulata and Ae. comosa using PCR on DNA amplified from flow-sorted chromosomes and genomic DNA of wheat-Ae. geniculata addition lines, respectively. Six SSR markers were located on particular Aegilops chromosomes using sorted chromosomes, thus confirming the usefulness of this approach for physical mapping. The SSR markers are suitable for marker assisted selection of wheat-Aegilops introgression lines. The results obtained in this work provide new opportunities for dissecting genomes of wild relatives of wheat with the aim to assist in alien gene transfer and discovery of novel genes for wheat improvement. PMID:22132127

  14. Point source solutions and coupling parameters in cratering mechanics

    NASA Technical Reports Server (NTRS)

    Holsapple, K. A.; Schmidt, R. M.

    1987-01-01

    The use of a point source of an impactor energy and momentum to replace the effects of the impactor is examined. The general framework and notation of the impact cratering problems are described; it is determined that the cratering phenomena are governed by Froude, Cauchy, and Reynolds numbers. The coupling parameter concept is defined mathematically as the measure that governs limit point source solutions. Examples of cases where coupling parameters are used are presented. The relationships of the coupling parameter concept with steady flow and the Z-model of cratering of Maxwell (1973, 1977) are studied. Crater size, ejecta distributions, growth histories, time of formation, melt volume, and shock decay for various scale factors for impact cratering mechanics are calculated, and the applicability of the coupling parameter to the study of cratering mechanics is revealed.

  15. Magnetospheric plasma - Sources, wave-particle interactions and acceleration mechanisms.

    NASA Technical Reports Server (NTRS)

    Speiser, T. W.

    1971-01-01

    Some of the basic problems associated with magnetospheric physics are reviewed. The sources of magnetospheric plasma, with auroral particles included as a subset, are discussed. The possible ways in which the solar wind plasma can gain access to the magnetosphere are outlined. Some important consequences of wave-particle interactions are examined. Finally, the basic mechanisms which energize or accelerate particles by reconnection and convection are explained.

  16. Focal Mechanisms and Seismic Source Parameters in the Jalisco Block

    NASA Astrophysics Data System (ADS)

    Gutierrez, Q. J.; Nunez-Cornu, F. J.; Escudero, C. R.

    2013-12-01

    The Jalisco Block is a very complex tectonic region delimited by the Middle America Trench at the west, the Colima grabben to the south, and the Tepic-Zacoalco grabben to the northeast. In this region great interplate and intraplate earthquakes have taken place historically. The main propose of this study is to estimate earthquake seismic source parameters with the objective of that helps to understand the physics of earthquake rupture mechanism and the tectonics in the region. We use data recorded by the MARS network (Mapping the Riviera Subduction Zone) a temporary seismic network with 50 stations installed in the states of Jalisco, Colima and Michoacán between January, 2006 and June 2007. We located more of 1000 events from February to November 2006 with magnitude between 2.0 to 4.5, using Hypo71 and a local P wave velocity model. To calculate focal mechanisms we read P-wave first motion polarity and MECFOC software was used which to determinate composite and individual mechanism. Before of apply the method for source parameters we first remove the trend, the mean and the instrument response and we corrected for attenuation; then manually chosen the S wave, the multitaper method was used to obtain the spectrum of this wave and so estimate the corner frequency and the spectra level. We substitute the obtained values in the equations of the Brune model to calculate the source parameters (the stress drop, the fault radius, the rupture area and the seismic moment).

  17. AE8/AP8 Implementations in AE9/AP9, IRBEM, and SPENVIS

    DTIC Science & Technology

    2014-02-18

    radiation belt model, SHIELDOSE, AE8/AP8 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 19a. NAME OF RESPONSIBLE...a wide range of locations within the radiation belts . The new AE9/AP9 model application includes the ability to query the legacy AE8 and AP8 models...trapped particle fluxes with the NASA models AP-8 and AE-8, Radiat . Meas., 26, pp. 947-952. International Association of Geomagnetism and Aeronomy

  18. Application of Normal Mode Expansion to AE Waves in Finite Plates

    NASA Technical Reports Server (NTRS)

    Gorman, M. R.; Prosser, W. H.

    1997-01-01

    Breckenridge et al. (1975), Hsu (1985) and Pao (1978) adapted approaches from seismology to calculate the response at the surface of an infinite half-space and an infinite plate. These approaches have found use in calibrating acoustic emission (AE) transducers. However, it is difficult to extend this theoretical approach to AE testing of practical structures. Weaver and Pao (1982) considered a normal mode solution to the Lamb equations. Hutchinson (1983) pointed out the potential relevance of Mindlin's plate theory (1951) to AE. Pao (1982) reviewed Medick s (1961) classical plate theory for a point source, but rejected it as useful for AE and no one seems to have investigated its relevance to AE any further. Herein, a normal mode solution to the classical plate bending equation was investigated for its applicability to AE. The same source-time function chosen by Weaver and Pao is considered. However, arbitrary source and receiver positions are chosen relative to the boundaries of the plate. This is another advantage of the plate theory treatment in addition to its simplicity. The source does not have to be at the center of the plate as in the axisymmetric treatment. The plate is allowed to remain finite and reflections are predicted. The importance of this theory to AE is that it can handle finite plates, realistic boundary conditions, and can be extended to composite materials.

  19. The AE-8 trapped electron model environment

    NASA Technical Reports Server (NTRS)

    Vette, James I.

    1991-01-01

    The machine sensible version of the AE-8 electron model environment was completed in December 1983. It has been sent to users on the model environment distribution list and is made available to new users by the National Space Science Data Center (NSSDC). AE-8 is the last in a series of terrestrial trapped radiation models that includes eight proton and eight electron versions. With the exception of AE-8, all these models were documented in formal reports as well as being available in a machine sensible form. The purpose of this report is to complete the documentation, finally, for AE-8 so that users can understand its construction and see the comparison of the model with the new data used, as well as with the AE-4 model.

  20. Source mechanism of the 2014 Aegean Sea earthquake

    NASA Astrophysics Data System (ADS)

    Nakano, Masaru

    2016-04-01

    Rapid determination of centroid moment tensor (CMT) of earthquakes, namely the source centroid location, focal mechanism, and magnitude is important for early disaster responses and issuing Tsunami warnings. In order to evaluate capability of Turkey seismic network for rapid determinations of CMT, I investigate the source mechanism of the 2014 Aegean Sea earthquake (Mw 6.9). Although this event occur out of Turkey seismic network, I obtained stable CMT solution. The CMT solution of this earthquake represents a strike-slip fault, consistent with the geometry of the North Anatolian Fault (NAF), and the source-time function indicates that this event comprised several distinct subevents. Each subevent is considered to have ruptured a different fault segment. This observation indicates the existence of a mechanical barrier, namely a NAF segment boundary, at the hypocenter. I also determined CMT solutions of background seismicity. CMT solutions of background seismicity beneath the Aegean Sea represent strike-slip or normal faulting along the NAF or its branch faults. The tensional axes of these events are oriented northeast-southwest, indicating a transtensional tectonic regime. Beneath the Sea of Marmara, the CMT solutions represent mostly strike-slip faulting, consistent with the motion of the NAF, but we identified a normal fault event with a tensional axis parallel to the strike of the NAF. This mechanism indicates that a pull-apart basin, marking a segment boundary of the NAF, is developing there. Because ruptures of a fault system and large earthquake magnitudes are strongly controlled by the fault system geometry and fault length, mapping fault segments along NAF can help to improve the accuracy of scenarios developed for future disastrous earthquakes in the Marmara region.

  1. Plasma and radio waves from Neptune: Source mechanisms and propagation

    NASA Technical Reports Server (NTRS)

    Wong, H. K.

    1994-01-01

    This report summarizes results obtained through the support of NASA Grant NAGW-2412. The objective of this project is to conduct a comprehensive investigation of the radio wave emission observed by the planetary radio astronomy (PRA) instrument on board Voyager 2 as if flew by Neptune. This study has included data analysis, theoretical and numerical calculations, ray tracing, and modeling to determine the possible source mechanism(s) and locations of the Neptune radio emissions. We have completed four papers, which are included in the appendix. The paper 'Modeling of Whistler Ray Paths in the Magnetosphere of Neptune' investigated the propagation and dispersion of lighting-generated whistler in the magnetosphere of Neptune by using three dimensional ray tracing. The two papers 'Numerical Simulations of Bursty Radio Emissions from Planetary Magnetospheres' and 'Numerical Simulations of Bursty Planetary Radio Emissions' employed numerical simulations to investigate an alternate source mechanism of bursty radio emissions in addition to the cyclotron maser instability. We have also studied the possible generation of Z and whistler mode waves by the temperature anisotropic beam instability and the result was published in 'Electron Cyclotron Wave Generation by Relativistic Electrons.' Besides the aforementioned studies, we have also collaborated with members of the PRA team to investigate various aspects of the radio wave data. Two papers have been submitted for publication and the abstracts of these papers are also listed in the appendix.

  2. Microwave subsecond pulses in solar flares - source localization, emission mechanism

    NASA Astrophysics Data System (ADS)

    Altyntsev, A. T.; Kardapolova, N. N.; Kuznetsov, A. A.; Lesovoi, S. V.; Meshalkina, N. S.; Yan, Y.

    The observations of bursts with fine temporal structures is one of few ways to study the primary energy release sites in solar flares. The localization of their sources in a flare region using the Siberian Solar Radio Telescope data (5.7 GHz) provide us with the unique possibility to determine plasma parameters, and to verify emission mechanisms. The simultaneous spectral observations (5.2 - 7.7 GHz) were provided by National Astronomical Observatories/Beijing spectropolarimeters. An analysis is made of the subsecond pulses of different types: short duration wide band pulses, U-type cm-bursts, the bursts with the "zebra" pattern. The suggestion is justified that in many cases the frequency drifts are response to the plasma density dynamics in the local sites in flare loops. It is argued that the conditions of emission escaping from the source strongly influent the apparent source sizes and the polarization degree of the subsecond sources. This research was supported by Grants 02-02-39030 and 03-02-16229 of RFBR, and E02-3.2-489 of Education department of Russia.

  3. Propagation of Flexural Mode AE Signals in GR/EP Composite Plates

    NASA Technical Reports Server (NTRS)

    Prosser, W. H.; Gorman, M. R.

    1992-01-01

    It has been documented that AE signals propagate in thin plates as extensional and flexural plate modes. This was demonstrated using simulated AE sources (pencil lead breaks) by Gorman on thin aluminum and gr/ep composite plates and by Gorman and Prosser on thin aluminum plates. A typical signal from a pencil lead break source which identifies these two modes is shown. AE signals from transverse matrix cracking sources in gr/ep composite plates were also shown to propagate as plate modes by Gorman and Ziola. Smith showed that crack growth events in thin aluminum plates under spectrum fatigue loading produced signals that propagated as plate modes. Additionally, Prosser et al. showed that AE signals propagated as plate modes in a thin walled composite tube.

  4. Effects of oxygen plasma source ion implantation on microstructure evolution and mechanical properties of nickel-titanium shape memory alloy

    NASA Astrophysics Data System (ADS)

    Tan, Lizhen

    Near-equiatomic NiTi is an important shape memory alloy used in both medical and non-medical applications, which are dependent upon the surface characteristics of NiTi. The work presented here is the first use of plasma source ion implantation with oxygen as the incident species to modify the surface structure of NiTi shape memory alloy. Two levels of voltage bias and three levels of ion dose were employed to investigate the effect of processing parameters on surface microstructure and surface-related properties. Several surface analytical techniques, Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and atomic force microscopy (AFM), were employed to analyze the effects of the surface modification on surface characteristics including oxide thickness, oxide constitution, phase distribution, morphology and topography. A two-layer surface structure consisting of an oxide layer and a precipitate accommodation layer was observed on modified NiTi. The surface morphology, roughness and hydrophilicity, which are considered to play important roles in affecting protein adsorption behavior, were found to be altered by surface modification. The effects of surface modification on surface-related properties including corrosion resistance, hardness and wear resistance were evaluated by cyclic potentiodynamic polarization tests, Knoop hardness microindentation and fretting wear tests, respectively. The optimum corrosion and wear resistance of NiTi were achieved with ion implantation under high bias and moderate dose. Archard's equation was modified by incorporating the pseudoelasticity effect on wear resistance in addition to hardness. The modified Archard's equation better describes the fretting wear resistance of NiTi. A combination of nanoindentation and AES was employed to understand the relationship between mechanical properties and composition of the modified material.

  5. Clarifying the dominant sources and mechanisms of cirrus cloud formation.

    PubMed

    Cziczo, Daniel J; Froyd, Karl D; Hoose, Corinna; Jensen, Eric J; Diao, Minghui; Zondlo, Mark A; Smith, Jessica B; Twohy, Cynthia H; Murphy, Daniel M

    2013-06-14

    Formation of cirrus clouds depends on the availability of ice nuclei to begin condensation of atmospheric water vapor. Although it is known that only a small fraction of atmospheric aerosols are efficient ice nuclei, the critical ingredients that make those aerosols so effective have not been established. We have determined in situ the composition of the residual particles within cirrus crystals after the ice was sublimated. Our results demonstrate that mineral dust and metallic particles are the dominant source of residual particles, whereas sulfate and organic particles are underrepresented, and elemental carbon and biological materials are essentially absent. Further, composition analysis combined with relative humidity measurements suggests that heterogeneous freezing was the dominant formation mechanism of these clouds.

  6. Mechanical model of precursory source processes for some large earthquakes

    SciTech Connect

    Dmorvska, R.; Li, V.C.

    1982-04-01

    A mechanical model is presented of precursory source processes for some large earthquakes along plate boundaries. It is assumed that the pre-seismic period consists of the upward progression of a zone of slip from lower portions of the lithosphere towards the Earth's surface. The slip front is blocked by local asperities of different size and strength; these asperities may be zones of real alteration of inherent strength, or instead may be zones which are currently stronger due to a local slowdown of a basically rate-dependent frictional response. Such blocking by a single, large asperity, or array of asperities, produces quiescence over a segment of plate boundary, until gradual increase of the stress concentration forces the slip zone through the blocked region at one end of the gap, thus nucleating a seismic rupture that propogates upwards and towards the other end. This model is proposed to explain certain distinctive seismicity patterns that have been observed before large earthquakes, notably quiescence over the gap zone followed by clustering at its end prior to the main event. A discussion of mechanical factors influencing the process is presented and some introductory modelling, performed with the use of a generalized Elsasser model for lithospheric plates and the ''line spring'' model for part-through flaws (slip zones) at plate boundaries, is outlined briefly.

  7. Microearthquake source mechanism studies at the Geysers geothermal field

    SciTech Connect

    Kirkpatrick, A.; Romero, A. Jr.; Peterson, J. Jr.; Johnson, L.; Majer, E.

    1996-04-01

    In this paper the authors discuss moment tensors obtained from inversion of MEQ waveform data recorded at the Southeast (SE) and Northwest (NW) Geysers geothermal areas by the high-resolution seismic networks operated by Lawrence Berkeley National Laboratory (Berkeley Lab) and the Coldwater Creek Geothermal Company (now CCPA). The network in the SE Geysers consists of 13 high-frequency (4.5 Hz), digital (480 samples), three-component, telemetered stations deployed on the surface in portions of the Calpine, Unocal-NEC-Thermal (U-N-T), and Northern California Power Agency (NCPA) leases. The network in the NW Geysers is a 16-station borehole array of three-component geophones (4.5 Hz), digital at 400 samples/sec, and telemetered to a central site. One of the main objectives of Berkeley Lab`s program at the Geysers is to assess the utility of MEQ monitoring as a reservoir management tool. Discrimination of the mechanisms of these events may aid in the interpretation of MEQ occurrence patterns and their significance to reservoir processes and conditions of interest to reservoir managers. Better understanding of the types of failure deduced from source mechanism studies, and their relations to production parameters, should also lead to a better understanding of the effects of injection and withdrawal.

  8. Étude comparative des techniques d'analyse par fluorescence X à dispersion d'énergie (ED-XRF) et à dispersion de longueur d'onde (WD-XRF), et par spectrométrie d'émission atomique à source plasma couplée par induction (ICP-AES)

    NASA Astrophysics Data System (ADS)

    Rahmani, A.; Benyaïch, F.; Bounakhla, M.; Bilal, E.; Moutte, J.; Gruffat, J. J.; Zahry, F.

    2004-11-01

    Dans ce travail, nous présentons une étude comparative des techniques d'analyse par fluorescence X à dispersion d'énergie (ED-XRF) et à dispersion de longueur d'onde (WD-XRF), et par spectrométrie d'émission atomique à source plasma couplée par induction (ICP-AES). Les résultats de la calibration des spectromètres à dispersion d'énergie, à excitation par sources radioactives (55Fe, 109Cd et 241Am) et à excitation secondaire (cible secondaire Mo et Cu) du Centre National pour l'Energie, les Sciences et les Techniques Nucléaires (CNESTEN, Rabat, Maroc) sur des échantillons étalons de références de l'Agence International de l'Energie Atomique (AIEA) et du Community Bureau of Référence (BCR) ont été comparés aux résultats d'analyse des mêmes échantillons étalons par la spectrométrie X à dispersion de longueur d'onde (WD-XRF) et par spectrométrie d'émission atomique à source plasma couplé par induction (ICP-AES) au département GENERIC du centre SPIN à l'Ecole des Mines de Saint-Etienne (France). Les trois techniques d'analyse utilisées donnent des résultats comparables pour le dosage des éléments majeurs, alors que pour les traces on note des déviations importantes à cause des effets de matrice qui sont difficiles à corriger dans le cas de la fluorescence X.

  9. Acoustic emissions (AE) monitoring of large-scale composite bridge components

    NASA Astrophysics Data System (ADS)

    Velazquez, E.; Klein, D. J.; Robinson, M. J.; Kosmatka, J. B.

    2008-03-01

    Acoustic Emissions (AE) has been successfully used with composite structures to both locate and give a measure of damage accumulation. The current experimental study uses AE to monitor large-scale composite modular bridge components. The components consist of a carbon/epoxy beam structure as well as a composite to metallic bonded/bolted joint. The bonded joints consist of double lap aluminum splice plates bonded and bolted to carbon/epoxy laminates representing the tension rail of a beam. The AE system is used to monitor the bridge component during failure loading to assess the failure progression and using time of arrival to give insight into the origins of the failures. Also, a feature in the AE data called Cumulative Acoustic Emission counts (CAE) is used to give an estimate of the severity and rate of damage accumulation. For the bolted/bonded joints, the AE data is used to interpret the source and location of damage that induced failure in the joint. These results are used to investigate the use of bolts in conjunction with the bonded joint. A description of each of the components (beam and joint) is given with AE results. A summary of lessons learned for AE testing of large composite structures as well as insight into failure progression and location is presented.

  10. Source regions and water release mechanisms of Martian Valley Networks

    NASA Astrophysics Data System (ADS)

    Jaumann, R.; Reiss, D.; Sander, T.; Gwinner, K.; Roatsch, T.; Matz, K.-D.; Hauber, E.; Mertens, V.; Hoffmann, H.; Neukum, G.; HRSC Co-Investigator Team

    Martian valley networks have been cited as the best evidence that Mars maintained flow of liquid water across the surface. Although internal structures associated with a fluvial origin within valleys like inner channels, terraces, slip-off and undercut slopes are extremely rare on Mars (Carr and Malin, 2000) such features can be identified in high-resolution imagery (e.g. Malin and Edgett, 2001; Jaumann et al., 2005). However, besides internal features the source regions are an important indicator for the flow processes in Martian valleys because they define the drainage area and thus constrain the amount of available water for eroding the valley network. Furthermore, the morphology of the source regions and their topographic characteristics provide information about the origin of the water. On Mars valley networks are thought to be formed by retreating erosion where the water is supplied from the sub-surface. However, the mechanisms that are responsible for the release of ground water are poorly understood. The three dimensional highly resolved data of the High Resolution Stereo Camera (HRSC) on the Mars Express Mission (Neukum et al., 2004) allow the detailed examination of valley network source regions. A valley network in the western Lybia Montes region valley between 1.4°N to 3.5°N and 81.6°E to 82.5°E originates at a highland mountain region and drains down to Isidis Planitia over a distance of 400 km. Most of its distance the valley exhibits an interior channel that allows to constraint discharge and erosion budgets (Jaumann, et al., 2005). The valley was formed in the Noachian/Hesperian between 3.7 and 3.3 billion years. However, discharge and erosion budgets restrict the erosion time to a few million years in total, indicating single events rather than continuous flow over long periods. The source region of the valley is covered by a series of lava flows. Even the upstream part of the valley is covered by lava flows that cover the interior channel

  11. 22 CFR 120.30 - The Automated Export System (AES).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false The Automated Export System (AES). 120.30... DEFINITIONS § 120.30 The Automated Export System (AES). The Automated Export System (AES) is the Department of Commerce, Bureau of Census, electronic filing of export information. The AES shall serve as the...

  12. Correlation of acoustic emission generated during uniform biaxial loading to microstructural sources in 7075-T651 aluminum and 21Cr-6Ni-9Mn stainless steel. Final report

    SciTech Connect

    Leon, E.; Mukherjee, A.K.

    1981-12-01

    This paper reports on the effect on acoustic emission (AE) of uniform biaxial loading of a thin-walled tube designed by Hamstad, Patterson and Mukherjee. The AE generated during biaxial loading of 7075-T651 aluminum and 21Cr-6Ni-9Mn stainless steel had several anomalous features relative to tensile generated AE. The biaxial AE data was of a much higher level and peaked at a lower strain than the uniaxial AE response. A particle cracking model was proposed in which inclusions with the largest projected surface area perpendicular to the principal axis of applied loading will crack before smaller inclusions, and the resulting energy released per AE will be proportional to the crack surface area. The inclusion contents were studied with respect to size, shape, density, hardness, and fracture/decohesion behavior. The inclusions in both 7075-T651 and 21-6-9 display the preferred cracking orientation predicted in the Hamstad, et al. model and are shown to be associated with the generated AE. However, other factors appear to contribute to the total AE responses. There is evidence that for 7075-T651 subjected to biaxial loading, a grain boundary-related mechanism becomes a significant source of AE in the latter stages of strain hardening. Also, for both materials, the complex applied load during biaxial loading appears to amplify the level of AE.

  13. Assessing Magnetospheric Accretion in Herbig Ae/Be Stars

    NASA Astrophysics Data System (ADS)

    Aarnio, Alicia; Monnier, John D.

    2017-01-01

    Recent large spectropolarimetric surveys have found low magnetic field detection rates in Herbig Ae/Be stars. Efforts to measure and map young stars' magnetic fields have also noted that field structure and strength dramatically change with increasing stellar mass. These results are highly suggestive that the mechanisms for accretion and outflow in Herbig Ae/Be star+disk systems may differ from the magnetospheric accretion paradigm as envisaged for T Tauri star+disk systems. We have performed a high resolution optical spectroscopic campaign of ~60 Herbig AeBe stars including some multi-epoch observations; the timescales sampled range from high cadence (~minutes) to observations taken years spart, covering a wide range of kinematic processes. We find that the strength of variability increases with the cadence of the observations, and over all timescales sampled, the strongest variability occurs within the blueshifted absorption components of the Balmer series lines. We see no inverse P-Cygni signatures as are often seen in lower mass T Tauri stars and generally thought to be diagnostic of infall in accretion streams along the line of sight. We discuss the implications of these results in context of recent spectropolarimetric surveys for our understanding of how accretion is occurring in these objects, as well as ongoing radiative transfer modeling.

  14. [Modern spectral estimation of ICP-AES].

    PubMed

    Zhang, Z; Jia, Q; Liu, S; Guo, L; Chen, H; Zeng, X

    2000-06-01

    The inductively coupled plasma atomic emission spectrometry (ICP-AES) and its signal characteristics were discussed using modern spectral estimation technique. The power spectra density (PSD) was calculated using the auto-regression (AR) model of modern spectra estimation. The Levinson-Durbin recursion method was used to estimate the model parameters which were used for the PSD computation. The results obtained with actual ICP-AES spectra and measurements showed that the spectral estimation technique was helpful for the better understanding about spectral composition and signal characteristics.

  15. Source mechanisms and source parameters of March 10 and September 13, 2007, United Arab Emirates Earthquakes

    SciTech Connect

    Marzooqi, Y A; Abou Elenean, K M; Megahed, A S; El-Hussain, I; Rodgers, A; Khatibi, E A

    2008-02-29

    On March 10 and September 13, 2007 two felt earthquakes with moment magnitudes 3.66 and 3.94 occurred in the eastern part of United Arab Emirates (UAE). The two events were accompanied by few smaller events. Being well recorded by the digital UAE and Oman digital broadband stations, they provide us an excellent opportunity to study the tectonic process and present day stress field acting on this area. In this study, we determined the focal mechanisms of the two main shocks by two methods (polarities of P and regional waveform inversion). Our results indicate a normal faulting mechanism with slight strike slip component for the two studied events along a fault plane trending NNE-SSW in consistent a suggested fault along the extension of the faults bounded Bani Hamid area. The Seismicity distribution between two earthquake sequences reveals a noticeable gap that may be a site of a future event. The source parameters (seismic moment, moment magnitude, fault radius, stress drop and displacement across the fault) were also estimated based on the far field displacement spectra and interpreted in the context of the tectonic setting.

  16. Matt Rogers on AES Energy Storage

    SciTech Connect

    Rogers, Matt

    2010-01-01

    The Department of Energy and AES Energy Storage recently agreed to a $17.1M conditional loan guarantee commitment. This project will develop the first battery-based energy storage system to provide a more stable and efficient electrical grid for New York State's high-voltage transmission network. Matt Rogers is the Senior Advisor to the Secretary for Recovery Act Implementation.

  17. Matt Rogers on AES Energy Storage

    ScienceCinema

    Rogers, Matt

    2016-07-12

    The Department of Energy and AES Energy Storage recently agreed to a $17.1M conditional loan guarantee commitment. This project will develop the first battery-based energy storage system to provide a more stable and efficient electrical grid for New York State's high-voltage transmission network. Matt Rogers is the Senior Advisor to the Secretary for Recovery Act Implementation.

  18. AE Geomagnetic Index Predictability for High Speed Solar Wind Streams: A Wavelet Decomposition Technique

    NASA Technical Reports Server (NTRS)

    Guarnieri, Fernando L.; Tsurutani, Bruce T.; Hajra, Rajkumar; Echer, Ezequiel; Gonzalez, Walter D.; Mannucci, Anthony J.

    2014-01-01

    High speed solar wind streams cause geomagnetic activity at Earth. In this study we have applied a wavelet interactive filtering and reconstruction technique on the solar wind magnetic field components and AE index series to allowed us to investigate the relationship between the two. The IMF Bz component was found as the most significant solar wind parameter responsible by the control of the AE activity. Assuming magnetic reconnection associated to southward directed Bz is the main mechanism transferring energy into the magnetosphere, we adjust parameters to forecast the AE index. The adjusted routine is able to forecast AE, based only on the Bz measured at the L1 Lagrangian point. This gives a prediction approximately 30-70 minutes in advance of the actual geomagnetic activity. The correlation coefficient between the observed AE data and the forecasted series reached values higher than 0.90. In some cases the forecast reproduced particularities observed in the signal very well.The high correlation values observed and the high efficacy of the forecasting can be taken as a confirmation that reconnection is the main physical mechanism responsible for the energy transfer during HILDCAAs. The study also shows that the IMF Bz component low frequencies are most important for AE prediction.

  19. Ice quake source mechanisms explored with paired imagery and seismograms

    NASA Astrophysics Data System (ADS)

    Bartholomaus, T. C.; Larsen, C. F.; O'Neel, S.; West, M. E.

    2010-12-01

    At Yahtse Glacier, a tidewater glacier on the Gulf of Alaska, we have used a variety of geophysical techniques to match elements of the iceberg calving process with seismograms. Individual, observed calving events, which span a size range from roughly 10 m3 up to 107 m3, can last for several minutes and often share a number of characteristics on the seismograms that record them. These features, including emergent onsets and a lack of clear P- or S- wave arrivals, confound traditional earthquake locating routines. Careful analyses of source mechanics and the potential development of an automatic “calving detector” are also hampered. We compare seismograms from ten broadband seismometers installed around the glacier margin with 3-5 Hz still and video photography, and in-person observations to match the style, magnitude, and temporal progression of calving events with their seismic data. By drawing on a subset of calving events observed during June and September 2010 fieldwork, we make distinctions about the patterns of large and small seismic events, as well as from those that proceed as simple drops, avalanches of loose ice debris, topples of intact columns or ice flakes, or submarine-generated icebergs breaking off a submerged glacier toe. We show that calving often proceeds as a cascade of discrete events, all occurring at the same location along the terminus. Larger events are preceded by smaller events, in which loose interstitial ice falls out from between otherwise undamaged flakes and columns of ice. The release of this interstitial ice destabilizes the nearby terminus and is often followed by the collapse of much larger sections of the terminal ice cliff. Each part of this process has a distinct expression on our seismograms. The identification of these cascades of linked calving events allows for a more complete understanding of the glacier calving process. Furthermore, we use our record of observed calving events to test a new ice quake

  20. Investigation of AE Features in Grinding

    NASA Astrophysics Data System (ADS)

    Chen, Xun; Mohammed, Arif; Oluwajobi, Akinjide

    2012-05-01

    This paper presents recent investigation of acoustic emission (AE) behaviours in grinding processes. It demonstrated the acoustic emission features characterized in time and frequency domain are influenced by thermal behaviours of materials. By control laser conditions, the temperature elevation under laser irradiation can be similar to that in a grinding process. Therefore, an innovative concept that grinding process can be monitored by using thermal AE signatures from laser irradiation tests has been proposed. Accordingly, an artificial neural network (ANN), built on laser irradiation tests, was applied to monitor grinding thermal performance. The results showed that grinding performance variation due to wheel wear can be identified by using the ANN. This development could bring great benefits by reducing experimental works in the preparation of an ANN for grinding monitoring.

  1. Atmosphere Explorer (AE) spacecraft system description

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The principal design and performance characteristics of the AE spacecraft system designed to support the Atmosphere Explorer C, D, and E missions are summarized. It has been prepared for the information of experimenters and other participants in the Atmosphere Explorer program as a general guide for design and operational planning. The description represents the spacecraft system as defined at the conclusion of the interface definition study.

  2. Managing with A/E Ease

    DTIC Science & Technology

    1988-07-01

    provides a very good foundation on which to build the EASE programs. EASE application programs are a supplementary menu system to Enable’s own menus...mainframe computer systems. Other Peripherals Plotters provide the color graphics output necessary for A/E drawings , which is far superior to that of...for interactive drawing on the display. The EASE program was not designed to be driven by a mouse, but this possibility is currently being studied

  3. AES Water Architecture Study Interim Results

    NASA Technical Reports Server (NTRS)

    Sarguisingh, Miriam J.

    2012-01-01

    The mission of the Advanced Exploration System (AES) Water Recovery Project (WRP) is to develop advanced water recovery systems in order to enable NASA human exploration missions beyond low earth orbit (LEO). The primary objective of the AES WRP is to develop water recovery technologies critical to near term missions beyond LEO. The secondary objective is to continue to advance mid-readiness level technologies to support future NASA missions. An effort is being undertaken to establish the architecture for the AES Water Recovery System (WRS) that meets both near and long term objectives. The resultant architecture will be used to guide future technical planning, establish a baseline development roadmap for technology infusion, and establish baseline assumptions for integrated ground and on-orbit environmental control and life support systems (ECLSS) definition. This study is being performed in three phases. Phase I of this study established the scope of the study through definition of the mission requirements and constraints, as well as indentifying all possible WRS configurations that meet the mission requirements. Phase II of this study focused on the near term space exploration objectives by establishing an ISS-derived reference schematic for long-duration (>180 day) in-space habitation. Phase III will focus on the long term space exploration objectives, trading the viable WRS configurations identified in Phase I to identify the ideal exploration WRS. The results of Phases I and II are discussed in this paper.

  4. Spatiotemporal patterns of acoustic emission (AE) activity in salt mine

    NASA Astrophysics Data System (ADS)

    Maghsoudi, S.; Cesca, S.; Hainzl, S.; Kaiser, D.; Dahm, T.

    2012-04-01

    Assessing the magnitude of completeness (Mc) is essential for the correct interpretation of earthquake catalogs. Knowledge on the spatiotemporal variation of Mc allows the mapping of other seismicity parameters, such as b-values. Spatial and temporal variations of b-values can indicate structural heterogeneities, stress perturbations and time-dependent fracturing processes. In order to precisely estimate Mc in strongly heterogeneous media, we propose a 3D development of the probabilistic magnitude of completeness (PMC) method, which relies on the analysis of network detection capabilities, to study spatial distribution of the Mc and b-value estimations for mining networks. We used a large dataset including more than 1 million acoustic emissions (AE), recorded at the Morsleben salt mine, Germany. Our study shows that the PMC estimations strongly depend on the source-receiver direction, and cannot be correctly accounted using a standard approach. The comparison between Mc using the 3D PMC method and Gutenberg-Richter methods show agreements for two reference depth ranges. Following our approach, we estimate Mc ranging between 1.25 (AE ,relative acoustic magnitude), at the center of the network, and 3.5, at further distances outside the network. Our method provides small-scale details about the capability of sensors to detect an AE event, and spatial distributions of Mc and b-value, which can be linked to the presence of structural heterogeneities or cavities in specific directions. Effects of heterogeneities on detection analysis are confirmed by synthetic tests using waveform modeling in heterogeneous media. This work has been funded by the German BMBF "Geotechnologien" project MINE (BMBF03G0737A).

  5. 3-D AE visualization of bone-cement fatigue locations.

    PubMed

    Qi, G; Pujol, J; Fan, Z

    2000-11-01

    This study addresses the visualization of crack locations in bone-cement material using a three-dimensional acoustic emission source location technique. Computer software based on an earthquake location technique was developed to determine AE source locations and was used to investigate material cracks formed at the tip of a notch in bone cement. The computed locations show that the cracks form linear features with dimensions between 0.1 and 0.2 mm although larger linear features (almost 3.5 mm) also are present. There is a difference of about 2.5 mm between the average of the event locations, and the location of the tip of the notch is 2.5 mm, which may be due to the finite size of the sensors (5 mm in diameter).

  6. 22 CFR 120.30 - The Automated Export System (AES).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false The Automated Export System (AES). 120.30 Section 120.30 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS PURPOSE AND DEFINITIONS § 120.30 The Automated Export System (AES). The Automated Export System (AES) is the Department...

  7. 22 CFR 120.30 - The Automated Export System (AES).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false The Automated Export System (AES). 120.30 Section 120.30 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS PURPOSE AND DEFINITIONS § 120.30 The Automated Export System (AES). The Automated Export System (AES) is the Department...

  8. 22 CFR 120.30 - The Automated Export System (AES).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false The Automated Export System (AES). 120.30 Section 120.30 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS PURPOSE AND DEFINITIONS § 120.30 The Automated Export System (AES). The Automated Export System (AES) is the Department...

  9. Numerical and experimental characterizations of low frequency MEMS AE sensors

    NASA Astrophysics Data System (ADS)

    Saboonchi, Hossain; Ozevin, Didem

    2013-04-01

    In this paper, new MEMS Acoustic Emission (AE) sensors are introduced. The transduction principle of the sensors is capacitance due to gap change. The sensors are numerically modeled using COMSOL Multiphysics software in order to estimate the resonant frequencies and capacitance values, and manufactured using MetalMUMPS process. The process includes thick metal layer (20 μm) made of nickel for freely vibration layer and polysilicon layer as the stationary layer. The metal layer provides a relatively heavy mass so that the spring constant can be designed high for low frequency sensor designs in order to increase the collapse voltage level (proportional to the stiffness), which increases the sensor sensitivity. An insulator layer is deposited between stationary layer and freely vibration layer, which significantly reduces the potential of stiction as a failure mode. As conventional AE sensors made of piezoelectric materials cannot be designed for low frequencies (<300 kHz) with miniature size, the MEMS sensor frequencies are tuned to 50 kHz and 200 kHz. The each sensor contained several parallel-connected cells with an overall size of approximately 250μm × 500 μm. The electromechanical characterizations are performed using high precision impedance analyzer and compared with the numerical results, which indicate a good fit. The initial mechanical characterization tests in atmospheric pressure are conducted using pencil lead break simulations. The proper sensor design reduces the squeeze film damping so that it does not require any vacuum packaging. The MEMS sensor responses are compared with similar frequency piezoelectric AE sensors.

  10. Artificial epi-Retinal Prosthesis (AeRP)

    NASA Astrophysics Data System (ADS)

    Doorish, John F.

    2006-09-01

    There are several research projects going on around the world, which are attempting to develop a prosthetic device to restore sight to the blind. This paper describes the efforts of Second Sight of New York, Inc. The device being developed is called an Artificial epi-Retinal Prosthesis (AeRP), which is basically a small optical computer that fits into the intraocular space of the eye. The AeRP is designed to draw light into the device by specially designed fibre optics. The light is ‘digitized’ by the fibre optic system and then directed to individual photodiode cells making up concentric cylinders thus providing several hundred photodiode cells in the device. The produced electrical stimulation from each cell is then delivered to the retinal ganglion cells by a specially designed delivery system utilizing electrically conducting polymer strands (ECP), which sit on an ‘umbrella’ at the back of the device. The retinal ganglion cells receive the electrical stimulation, which would then be transmitted through the visual system of the brain. There are several innovations in this approach as compared to the other projects. They include, first the design, which will allow for a high number of PC to produce electrical stimulation that will stimulate multiple RGC per PC; the use of the ECP strands has not been used in such an approach before this. Tests have revealed that nerve cells have a good affinity for the material of the ECP. The use of the ECP as well as the fact that the AeRP is completely photovoltaic, with no external power sources, implies that there will not be high heat build-up in the back of the eye, which might damage RGC. A smaller version of the AeRP called the Mini epi-Retinal Prosthesis (MeRP) is the subject of a complimentary paper. It is being built now and will be tested in cell culture studies to determine the efficacy of the design and materials. No actual implants have been performed yet.

  11. Hyperthermophilic Enzymes: Sources, Uses, and Molecular Mechanisms for Thermostability

    PubMed Central

    Vieille, Claire; Zeikus, Gregory J.

    2001-01-01

    Enzymes synthesized by hyperthermophiles (bacteria and archaea with optimal growth temperatures of >80°C), also called hyperthermophilic enzymes, are typically thermostable (i.e., resistant to irreversible inactivation at high temperatures) and are optimally active at high temperatures. These enzymes share the same catalytic mechanisms with their mesophilic counterparts. When cloned and expressed in mesophilic hosts, hyperthermophilic enzymes usually retain their thermal properties, indicating that these properties are genetically encoded. Sequence alignments, amino acid content comparisons, crystal structure comparisons, and mutagenesis experiments indicate that hyperthermophilic enzymes are, indeed, very similar to their mesophilic homologues. No single mechanism is responsible for the remarkable stability of hyperthermophilic enzymes. Increased thermostability must be found, instead, in a small number of highly specific alterations that often do not obey any obvious traffic rules. After briefly discussing the diversity of hyperthermophilic organisms, this review concentrates on the remarkable thermostability of their enzymes. The biochemical and molecular properties of hyperthermophilic enzymes are described. Mechanisms responsible for protein inactivation are reviewed. The molecular mechanisms involved in protein thermostabilization are discussed, including ion pairs, hydrogen bonds, hydrophobic interactions, disulfide bridges, packing, decrease of the entropy of unfolding, and intersubunit interactions. Finally, current uses and potential applications of thermophilic and hyperthermophilic enzymes as research reagents and as catalysts for industrial processes are described. PMID:11238984

  12. The spectrum and variability of radio emission from AE Aquarii

    NASA Technical Reports Server (NTRS)

    Abada-Simon, Meil; Lecacheux, Alain; Bastian, Tim S.; Bookbinder, Jay A.; Dulk, George A.

    1993-01-01

    The first detections of the magnetic cataclysmic variable AE Aquarii at millimeter wavelengths are reported. AE Aqr was detected at wavelengths of 3.4 and 1.25 mm. These data are used to show that the time-averaged spectrum is generally well fitted by a power law S(nu) varies as nu exp alpha, where alpha is approximately equal to 0.35-0.60, and that the power law extends to millimeter wavelengths, i.e., the spectral turnover is at a frequency higher than 240 GHz. It is suggested that the spectrum is consistent with that expected from a superposition of flarelike events where the frequency distribution of the initial flux density is a power law f (S0) varies as S0 exp -epsilon, with index epsilon approximately equal to 1.8. Within the context of this model, the high turnover frequency of the radio spectrum implies magnetic field strengths in excess of 250 G in the source.

  13. A tenuous X-ray corona enveloping AE Aquarii

    NASA Astrophysics Data System (ADS)

    Venter, L. A.; Meintjes, P. J.

    2007-06-01

    In this paper we propose that the observed unpulsed X-ray emission in AE Aquarii is the result of a very tenuous hot corona associated with the secondary star, which is pumped magnetohydrodynamically by the propeller action of the fast rotating white dwarf. It is shown that the closed coronal field of the secondary star envelops a substantial portion of the binary system, including the fast rotating magnetized white dwarf. This implies that the propeller outflow of material in AE Aquarii is initiated inside an enveloping magnetic cavity. The outflow crossing the secondary dead-zone field constitutes a βgen = (8πρv2esc/B2) >> 1 plasma, acting as a magnetohydrodynamic generator resulting in the induction of field-aligned currents in these closed magnetospheric circuits where βcir = (8πnkT/B2) << 1. The Ohmic heating of the coronal circuit can readily account for a Tx >= 107 K plasma in the coronal flux tubes connecting the generator and the stellar surface. Further, the bremsstrahlung losses of the thermal electrons in the coronal circuit can readily drive the observed unpulsed X-ray luminosity of Lx ~ 1031 ergs -1, which correlates with the luminosity and relatively large source implied by recent XMM-Newton observations.

  14. Higgs seesaw mechanism as a source for dark energy.

    PubMed

    Krauss, Lawrence M; Dent, James B

    2013-08-09

    Motivated by the seesaw mechanism for neutrinos which naturally generates small neutrino masses, we explore how a small grand-unified-theory-scale mixing between the standard model Higgs boson and an otherwise massless hidden sector scalar can naturally generate a small mass and vacuum expectation value for the new scalar which produces a false vacuum energy density contribution comparable to that of the observed dark energy dominating the current expansion of the Universe. This provides a simple and natural mechanism for producing the correct scale for dark energy, even if it does not address the long-standing question of why much larger dark energy contributions are not produced from the visible sector. The new scalar produces no discernible signatures in existing terrestrial experiments so that one may have to rely on other cosmological tests of this idea.

  15. Higgs Seesaw Mechanism as a Source for Dark Energy

    NASA Astrophysics Data System (ADS)

    Krauss, Lawrence M.; Dent, James B.

    2013-08-01

    Motivated by the seesaw mechanism for neutrinos which naturally generates small neutrino masses, we explore how a small grand-unified-theory-scale mixing between the standard model Higgs boson and an otherwise massless hidden sector scalar can naturally generate a small mass and vacuum expectation value for the new scalar which produces a false vacuum energy density contribution comparable to that of the observed dark energy dominating the current expansion of the Universe. This provides a simple and natural mechanism for producing the correct scale for dark energy, even if it does not address the long-standing question of why much larger dark energy contributions are not produced from the visible sector. The new scalar produces no discernible signatures in existing terrestrial experiments so that one may have to rely on other cosmological tests of this idea.

  16. Locating the Accretion Footprint on a Herbig Ae Star: MWC 480

    NASA Technical Reports Server (NTRS)

    Grady, C. A.; Hamaguchi, K.; Schneider, G.; Stecklum, B.; Woodgate, B. E.; McCleary, J. E.; Williger, G. M.; Sitko, M. L.; Menard, F.; Henning, Th.; Brittain, S.; Troutmann, M.; Donehew, B.; Hines, D.; Wisniewski, J. P.; Lynch, D. K.; Russell, R. W.; Rudy, R. J.; Day, A. M.; Shenoy, A.; Wilner, D.; Silverston, M.; Bouret, J.-C.; Clampin, M.; Petre, R.

    2011-01-01

    Accretion is a fundamental process which establishes the dynamics of the protoplanetary disk and the final properties of the forming star. In solar-type stars, the star-disk coupling is determined by the magnetic field structure, which is responsible for funneling material from the disk midplane to higher latitudes on the star. Here, we use pan-chromatic data for the Herbig Ae star MWC 480 to address whether similar processes occur in intermediate-mass stars. MWC 480 has X-ray emission typical of actively accreting Herbig Ae stars, but with 5-9 x more photoelectric absorption than expected from optical and FUV data. We consider 3 sources for the absorption: the disk absorption in a wind or jet, and accretion. While we detect the disk in scattered light in are-analysis of archival HST data. the data are consistent with grazing illumination of the dust disk. We find that MWC 480's disk is stratified, geometrically thin, and is not responsible for the observed photoelectric absorption. MWC 480 drives a bipolar jet, but with a mass loss rate which is low compared to other Herbig Ae stars, where the outflow is more favorably oriented and enhanced photoelectric absorption is not seen. This excludes a jet or wind origin for the enhanced photoelectric absorption. We compare MWC 480's 0 VI emission with other Herbig Ae stars. The distribution of the emission in inclination, and lack of a correlation of profile shape and system inclination excludes equatorially-confined accretion for the FUSE Herbig Ae stars. The photoelectric absorption data further suggest that the accretion footprint on MWC 480 and other Herbig Ae stars is located at high temperate, rather than polar, latitudes. These findings support the presence of funneled accretion in MWC 480 and Herbig Ae stars, strengthening the parallel to T Tauri stars.

  17. Characterization of Aes nuclear foci in colorectal cancer cells.

    PubMed

    Itatani, Yoshiro; Sonoshita, Masahiro; Kakizaki, Fumihiko; Okawa, Katsuya; Stifani, Stefano; Itoh, Hideaki; Sakai, Yoshiharu; Taketo, M Mark

    2016-01-01

    Amino-terminal enhancer of split (Aes) is a member of Groucho/Transducin-like enhancer (TLE) family. Aes is a recently found metastasis suppressor of colorectal cancer (CRC) that inhibits Notch signalling, and forms nuclear foci together with TLE1. Although some Notch-associated proteins are known to form subnuclear bodies, little is known regarding the dynamics or functions of these structures. Here, we show that Aes nuclear foci in CRC observed under an electron microscope are in a rather amorphous structure, lacking surrounding membrane. Investigation of their behaviour during the cell cycle by time-lapse cinematography showed that Aes nuclear foci dissolve during mitosis and reassemble after completion of cytokinesis. We have also found that heat shock cognate 70 (HSC70) is an essential component of Aes foci. Pharmacological inhibition of the HSC70 ATPase activity with VER155008 reduces Aes focus formation. These results provide insight into the understanding of Aes-mediated inhibition of Notch signalling.

  18. BOREAS AES READAC Surface Meteorological Data

    NASA Technical Reports Server (NTRS)

    Atkinson, G. Barrie; Funk, Barry; Hall, Forrest G. (Editor); Knapp, David E. (Editor)

    2000-01-01

    Canadian AES personnel collected and processed data related to surface atmospheric meteorological conditions over the BOREAS region. This data set contains 15-minute meteorological data from one READAC meteorology station in Hudson Bay, Saskatchewan. Parameters include day, time, type of report, sky condition, visibility, mean sea level pressure, temperature, dewpoint, wind, altimeter, opacity, minimum and maximum visibility, station pressure, minimum and maximum air temperature, a wind group, precipitation, and precipitation in the last hour. The data were collected non-continuously from 24-May-1994 to 20-Sep-1994. The data are provided in tabular ASCII files, and are classified as AFM-Staff data.

  19. BOREAS AES MARSII Surface Meteorological Data

    NASA Technical Reports Server (NTRS)

    Atkinson, G. Barrie; Funk, Barry; Hall, Forrest G. (Editor); Knapp, David E. (Editor)

    2000-01-01

    Canadian AES personnel collected several data sets related to surface and atmospheric meteorological conditions over the BOREAS region. This data set contains 15-minute meteorological data from six MARSII meteorology stations in the BOREAS region in Canada. Parameters include site, time, temperature, dewpoint, visibility, wind speed, wind gust, wind direction, two cloud groups, precipitation, and station pressure. Temporally, the data cover the period of May to September 1994. Geo-graphically, the stations are spread across the provinces of Saskatchewan and Manitoba. The data are provided in tabular ASCII files, and are classified as AFM-Staff data.

  20. Flavonoid basics: chemistry, sources, mechanisms of action, and safety.

    PubMed

    Corcoran, Michael P; McKay, Diane L; Blumberg, Jeffrey B

    2012-01-01

    In our efforts to understand how various dietary factors can influence the risk and progression of chronic disease, much recent research has focused on phytochemicals. Phytochemicals are defined as nonessential nutrients found in plant-based food, many of which have been established as bioactive and thus may affect human health. The largest group of phytochemicals is the polyphenols, comprised principally of the flavonoids, which are characterized chemically by two benzene rings joined by a linear carbon chain. Evidence from observational studies indicates that regular consumption of foods containing flavonoids may reduce the risk several chronic conditions, including neurodegenerative diseases, atherosclerosis, and certain forms of cancer. These results have generated considerable interest in flavonoids, although much basic information about their nutrient characteristics in humans remains limited, e.g., their bioavailability and metabolism, interactions with other dietary factors, mechanisms of action, and intakes associated with specific health outcomes. Although flavonoids are commonly defined as dietary antioxidants and their putative health benefits commonly attributed to this mechanism, it now appears their principal actions are mediated in vivo via other biochemical and molecular pathways.

  1. Oxidative Stress in COPD: Sources, Markers, and Potential Mechanisms

    PubMed Central

    McGuinness, Adam John Anthony; Sapey, Elizabeth

    2017-01-01

    Markers of oxidative stress are increased in chronic obstructive pulmonary disease (COPD) and reactive oxygen species (ROS) are able to alter biological molecules, signaling pathways and antioxidant molecule function, many of which have been implicated in the pathogenesis of COPD. However, the involvement of ROS in the development and progression of COPD is not proven. Here, we discuss the sources of ROS, and the defences that have evolved to protect against their harmful effects. We address the role that ROS may have in the development and progression of COPD, as well as current therapeutic attempts at limiting the damage they cause. Evidence has indicated that the function of several key cells appears altered in COPD patients, and expression levels of important oxidant and antioxidant molecules may be abnormal. Therapeutic trials attempting to restore equilibrium to these molecules have not impacted upon all facets of disease and whilst the theory behind ROS influence in COPD appears sound, current models testing relevant pathways to tissue damage are limited. The heterogeneity seen in COPD patients presents a challenge to our understanding, and further research is essential to identify potential targets and stratified COPD patient populations where ROS therapies may be maximally efficacious. PMID:28212273

  2. Announcing the Advanced Encryption Standard (AES)

    DTIC Science & Technology

    2007-11-02

    b9 da 5e 15 46 57 a7 8d 9d 84 6 90 d8 ab 00 8c bc d3 0a f7 e4 58 05 b8 b3 45 06 7 d0 2c 1e 8f ca 3f 0f 02 c1 af bd 03 01...e3 4a 46 cf 11 d6 5a d6 5a cf 11 09 63 cf d0 47 fe 7e 88 3 03 ef d2 9a 7b df b5 b8 b8 7b df b5 93 33 7c dc ⊕ 7d 3e 44 3b = 48 67 4d d6 52 85 e3 f6 52...6c fb c8 6c 4f d1 11 3a 4c d1 83 f2 f9 7f 63 35 be d2 fb 96 ae 96 ae d2 fb a9 d1 33 c0 c6 9d b8 15 5 e8 c0 50 01 9b ba 53 7c 7c 9b ba 53 ad 68 8e b0

  3. Source mechanics for monochromatic icequakes produced during iceberg calving at Columbia Glacier, AK

    USGS Publications Warehouse

    O'Neel, Shad; Pfeffer, W.T.

    2007-01-01

    Seismograms recorded during iceberg calving contain information pertaining to source processes during calving events. However, locally variable material properties may cause signal distortions, known as site and path effects, which must be eliminated prior to commenting on source mechanics. We applied the technique of horizontal/vertical spectral ratios to passive seismic data collected at Columbia Glacier, AK, and found no dominant site or path effects. Rather, monochromatic waveforms generated by calving appear to result from source processes. We hypothesize that a fluid-filled crack source model offers a potential mechanism for observed seismograms produced by calving, and fracture-processes preceding calving.

  4. Organizing for empowerment: an interview with AES's Roger Sant and Dennis Bakke. Interview by Suzy Wetlaufer.

    PubMed

    Sant, R; Bakke, D

    1999-01-01

    The topic of empowerment is receiving a lot of attention, but how many employees are truly empowered? At the global electricity giant AES Corporation, the answer is all 40,000 of them. In this interview, chairman Roger Sant and CEO Dennis Bakke reflect on their trials and triumphs in creating an exceptional company and explain how their employee-run company works. When they founded AES in 1981, Sant and Bakke set out to create a company where people could have engaging experiences on a daily basis--a company that embodied the principles of fairness, integrity, social responsibility, and fun. Putting those principles into action has created something unique--an ecosystem of real empowerment. What does that system look like? Rather than having a traditional hierarchical chain of command, AES is organized around small teams that are responsible for operations and maintenance. Moreover, AES has eliminated functional departments; there's no corporate marketing division or human resources department. For the system to work, every person must become a well-rounded generalist--a mini-CEO. That, in turn, redefines the jobs of the people at headquarters. Instead of setting strategy and making the "the big decisions," Sant and Bakke act as advisers, guardians of the principles, accountability officers, and chief encouragers. Can other companies successfully adopt the mechanics of such a system? Not unless they first adopt the shared principles that have guided AES since its inception. "Empowerment without values isn't empowerment," says Sant. "It's just technique," adds Bakke.

  5. Uses of AES and RGA to study neutron-irradiation-enhanced segregation to internal surfaces

    SciTech Connect

    Gessel, G.R.; White, C.L.

    1980-01-01

    The high flux of point defects to sinks during neutron irradiation can result in segregation of impurity or alloy additions to metals. Such segregants can be preexisting or produced by neutron-induced transmutations. This segregation is known to strongly influence swelling and mechanical properties. Over a period of years, facilities have been developed at ORNL incorporating AES and RGA to examine irradiated materials. Capabilities of this system include in situ tensile fracture at elevated temperatures under ultrahigh vacuum 10/sup -10/ torr and helium release monitoring. AES and normal incidence inert ion sputtering are exploited to examine segregation at the fracture surface and chemical gradients near the surface.

  6. AE Monitoring and Analysis of HVOF Thermal Spraying Process

    NASA Astrophysics Data System (ADS)

    Faisal, N. H.; Ahmed, R.; Reuben, R. L.; Allcock, B.

    2011-09-01

    This work presents an in situ monitoring of HVOF thermal spraying process through an acoustic emission (AE) technique in an industrial coating chamber. Single layer thermal spraying on substrate was carried out through slits. Continuous multilayer thermal spraying onto the sample without slit was also conducted. The AE was measured using a broadband piezoelectric AE sensor positioned on the back of the substrate. A mathematical model has been developed to determine the total kinetic energy of particles impacting the substrate through slits. Results of this work demonstrate that AE associated with particle impacts can be used for in situ monitoring of coating process. Results also show that the amplitude and AE energy is related to the spray gun transverse speed and the oxy-fuel pressure. The measured AE energy was found to vary with the number of particles impacting the substrate, determined using the mathematical model.

  7. BOREAS AES Campbell Scientific Surface Meteorological Data

    NASA Technical Reports Server (NTRS)

    Atkinson, G. Barrie; Funk, Barrie; Knapp. David E. (Editor); Hall, Forrest G. (Editor)

    2000-01-01

    Canadian AES personnel collected data related to surface and atmospheric meteorological conditions over the BOREAS region. This data set contains 15-minute meteorological data from 14 automated meteorology stations located across the BOREAS region. Included in this data are parameters of date, time, mean sea level pressure, station pressure, temperature, dew point, wind speed, resultant wind speed, resultant wind direction, peak wind, precipitation, maximum temperature in the last hour, minimum temperature in the last hour, pressure tendency, liquid precipitation in the last hour, relative humidity, precipitation from a weighing gauge, and snow depth. Temporally, the data cover the period of August 1993 to December 1996. The data are provided in tabular ASCII files, and are classified as AFM-Staff data.

  8. Talker identification across source mechanisms: Experiments with laryngeal and electrolarynx speech

    PubMed Central

    Perrachione, Tyler K.; Stepp, Cara E.; Hillman, Robert E.; Wong, Patrick C.M.

    2015-01-01

    Purpose To determine listeners' ability to learn talker identity from speech produced with an electrolarynx, explore source and filter differentiation in talker identification, and describe acoustic-phonetic changes associated with electrolarynx use. Method Healthy adult control listeners learned to identify talkers from speech recordings produced using talkers' normal laryngeal vocal source or an electrolarynx. Listeners' abilities to identify talkers from the trained vocal source (Experiment 1) and generalize this knowledge to the untrained source (Experiment 2) were assessed. Acoustic-phonetic measurements of spectral differences between source mechanisms were performed. Additional listeners attempted to match recordings from different source mechanisms to a single talker (Experiment 3). Results Listeners successfully learned talker identity from electrolarynx speech, but less accurately than from laryngeal speech. Listeners were unable to generalize talker identity to the untrained source mechanism. Electrolarynx use resulted in vowels with higher F1 frequencies compared to laryngeal speech. Listeners matched recordings from different sources to a single talker better than chance. Conclusions Electrolarynx speech, though lacking individual differences in voice quality, nevertheless conveys sufficient indexical information related to the vocal filter and articulation for listeners to identify individual talkers. Psychologically, perception of talker identity arises from a “gestalt” of the vocal source and filter. PMID:24801962

  9. Cluster analysis of stress corrosion mechanisms for steel wires used in bridge cables through acoustic emission particle swarm optimization.

    PubMed

    Li, Dongsheng; Yang, Wei; Zhang, Wenyao

    2017-05-01

    Stress corrosion is the major failure type of bridge cable damage. The acoustic emission (AE) technique was applied to monitor the stress corrosion process of steel wires used in bridge cable structures. The damage evolution of stress corrosion in bridge cables was obtained according to the AE characteristic parameter figure. A particle swarm optimization cluster method was developed to determine the relationship between the AE signal and stress corrosion mechanisms. Results indicate that the main AE sources of stress corrosion in bridge cables included four types: passive film breakdown and detachment of the corrosion product, crack initiation, crack extension, and cable fracture. By analyzing different types of clustering data, the mean value of each damage pattern's AE characteristic parameters was determined. Different corrosion damage source AE waveforms and the peak frequency were extracted. AE particle swarm optimization cluster analysis based on principal component analysis was also proposed. This method can completely distinguish the four types of damage sources and simplifies the determination of the evolution process of corrosion damage and broken wire signals.

  10. An unsupervised pattern recognition approach for AE data originating from fatigue tests on polymer-composite materials

    NASA Astrophysics Data System (ADS)

    Doan, D. D.; Ramasso, E.; Placet, V.; Zhang, S.; Boubakar, L.; Zerhouni, N.

    2015-12-01

    This work investigates acoustic emission generated during tension fatigue tests carried out on a carbon fiber reinforced polymer (CFRP) composite specimen. Since massive fatigue data processing, especially noise reduction, remains an important challenge in AE data analysis, a Mahalanobis distance-based noise modeling has been proposed in the present work to tackle this problem. A sequential feature selection based on Davies-Bouldin index has been implemented for fast dimensionality reduction. An unsupervised classifier offline-learned from quasi-static data is then used to classify the data to different AE sources with the possibility to dynamically accommodate with unseen ones. With an efficient proposed noise removal and automatic separation of AE events, this pattern discovery procedure provides an insight into fatigue damage development in composites in the presence of millions of AE events.

  11. Multiple Lookup Table-Based AES Encryption Algorithm Implementation

    NASA Astrophysics Data System (ADS)

    Gong, Jin; Liu, Wenyi; Zhang, Huixin

    Anew AES (Advanced Encryption Standard) encryption algorithm implementation was proposed in this paper. It is based on five lookup tables, which are generated from S-box(the substitution table in AES). The obvious advantages are reducing the code-size, improving the implementation efficiency, and helping new learners to understand the AES encryption algorithm and GF(28) multiplication which are necessary to correctly implement AES[1]. This method can be applied on processors with word length 32 or above, FPGA and others. And correspondingly we can implement it by VHDL, Verilog, VB and other languages.

  12. PDS 144: The First Confirmed Herbig Ae-Herbig Ae Wide Binary

    NASA Technical Reports Server (NTRS)

    Hornbeck, J. B.; Grady, C. A.; Perrin, M. D.; Wisniewski, J. P.; Tofflemire, B. M.; Brown, A.; Holtzman, J. A.; Arraki, K.; Hamaguchi, K.; Woodgate, B.; Petre, R.; Daly, B.; Grogin, N. A.; Bonfield, D. G.; Williger, G. M.; Lauroesch, J. T.

    2012-01-01

    PDS 144 is a pair of Herbig Ae stars that are separated by 5.35" on the sky. It has previously been shown to have an A2Ve Herbig Ae star viewed at 83 deg inclination as its northern member and an A5Ve Herbig Ae star as its southern member. Direct imagery revealed a disk occulting PDS 144 N - the first edge-on disk observed around a Herbig Ae star. The lack of an obvious disk in direct imagery suggested PDS 144 S might be viewed face-on or not physically associated with PDS 144 N. Multi-epoch HST imagery of PDS 144 with a 5 yr baseline demonstrates PDS 144 N & S are comoving and have a common proper motion with TYC 6782-878-1. TYC 6782-878-1 has previously been identified as a member of Upper Sco sub-association A at d = 145 +/- 2 pc with an age of 5 - 10 Myr. Ground-based imagery reveals jets and a string of HH knots extending 13' (possibly further) which are aligned to within 7 deg +/- 6 deg on the sky. By combining proper motion data and the absence of a dark mid-plane with radial velocity data, we measure the inclination of PDS 144 S to be i = 73 deg +/- 7 deg. The radial velocity of the jets from PDS 144 N & S indicates they, and therefore their disks, are misaligned by 25 deg +/- 9 deg.. This degree of misalignment is similar to that seen in T-Tauri wide binaries.

  13. Register of specialized sources for information on mechanics of structural failure

    NASA Technical Reports Server (NTRS)

    Carpenter, J. L., Jr.; Denny, F. J.

    1973-01-01

    Specialized information sources that generate information relative to six problem areas in aerospace mechanics of structural failure are identified. Selection for inclusion was based upon information obtained from the individual knowledge and professional contacts of Martin Marietta Aerospace staff members and the information uncovered by the staff of technical reviewers. Activities listed perform basic or applied research related to the mechanics of structural failure and publish the results of such research. The purpose of the register is to present, in easy reference form, original sources for dependable information regarding failure modes and mechanisms of aerospace structures.

  14. 15 CFR Appendix B to Part 30 - AES Filing Codes

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false AES Filing Codes B Appendix B to Part..., DEPARTMENT OF COMMERCE FOREIGN TRADE REGULATIONS Pt. 30, App. B Appendix B to Part 30—AES Filing Codes Part I—Method of Transportation Codes 10Vessel 11Vessel Containerized 12Vessel (Barge) 20Rail...

  15. 15 CFR Appendix B to Part 30 - AES Filing Codes

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 15 Commerce and Foreign Trade 1 2014-01-01 2014-01-01 false AES Filing Codes B Appendix B to Part 30 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade BUREAU OF THE CENSUS, DEPARTMENT OF COMMERCE FOREIGN TRADE REGULATIONS Pt. 30, App. B Appendix B to Part 30—AES Filing Codes Part...

  16. 15 CFR Appendix B to Part 30 - AES Filing Codes

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 15 Commerce and Foreign Trade 1 2011-01-01 2011-01-01 false AES Filing Codes B Appendix B to Part 30 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade BUREAU OF THE CENSUS, DEPARTMENT OF COMMERCE FOREIGN TRADE REGULATIONS Pt. 30, App. B Appendix B to Part 30—AES Filing Codes Part...

  17. 15 CFR Appendix B to Part 30 - AES Filing Codes

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 15 Commerce and Foreign Trade 1 2012-01-01 2012-01-01 false AES Filing Codes B Appendix B to Part 30 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade BUREAU OF THE CENSUS, DEPARTMENT OF COMMERCE FOREIGN TRADE REGULATIONS Pt. 30, App. B Appendix B to Part 30—AES Filing Codes Part...

  18. 15 CFR Appendix B to Part 30 - AES Filing Codes

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 15 Commerce and Foreign Trade 1 2013-01-01 2013-01-01 false AES Filing Codes B Appendix B to Part 30 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade BUREAU OF THE CENSUS, DEPARTMENT OF COMMERCE FOREIGN TRADE REGULATIONS Pt. 30, App. B Appendix B to Part 30—AES Filing Codes Part...

  19. Acoustic emission (AE) health monitoring of diaphragm type couplings using neural network analysis

    NASA Astrophysics Data System (ADS)

    Godinez-Azcuaga, Valery F.; Shu, Fong; Finlayson, Richard D.; O'Donnell, Bruce

    2005-05-01

    This paper presents the latest results obtained from Acoustic Emission (AE) monitoring and detection of cracks and/or damage in diaphragm couplings, which are used in some aircraft and engine drive systems. Early detection of mechanical failure in aircraft drive train components is a key safety and economical issue with both military and civil sectors of aviation. One of these components is the diaphragm-type coupling, which has been evaluated as the ideal drive coupling for many application requirements such as high speed, high torque, and non-lubrication. Its flexible axial and angular displacement capabilities have made it indispensable for aircraft drive systems. However, diaphragm-type couplings may develop cracks during their operation. The ability to monitor, detect, identify, and isolate coupling cracks on an operational aircraft system is required in order to provide sufficient advance warning to preclude catastrophic failure. It is known that metallic structures generate characteristic Acoustic Emission (AE) during crack growth/propagation cycles. This phenomenon makes AE very attractive among various monitoring techniques for fault detection in diaphragm-type couplings. However, commercially available systems capable of automatic discrimination between signals from crack growth and normal mechanical noise are not readily available. Positive classification of signals requires experienced personnel and post-test data analysis, which tend to be a time-consuming, laborious, and expensive process. With further development of automated classifiers, AE can become a fully autonomous fault detection technique requiring no human intervention after implementation. AE has the potential to be fully integrated with automated query and response mechanisms for system/process monitoring and control.

  20. The global compendium of Aedes aegypti and Ae. albopictus occurrence

    NASA Astrophysics Data System (ADS)

    Kraemer, Moritz U. G.; Sinka, Marianne E.; Duda, Kirsten A.; Mylne, Adrian; Shearer, Freya M.; Brady, Oliver J.; Messina, Jane P.; Barker, Christopher M.; Moore, Chester G.; Carvalho, Roberta G.; Coelho, Giovanini E.; van Bortel, Wim; Hendrickx, Guy; Schaffner, Francis; Wint, G. R. William; Elyazar, Iqbal R. F.; Teng, Hwa-Jen; Hay, Simon I.

    2015-07-01

    Aedes aegypti and Ae. albopictus are the main vectors transmitting dengue and chikungunya viruses. Despite being pathogens of global public health importance, knowledge of their vectors’ global distribution remains patchy and sparse. A global geographic database of known occurrences of Ae. aegypti and Ae. albopictus between 1960 and 2014 was compiled. Herein we present the database, which comprises occurrence data linked to point or polygon locations, derived from peer-reviewed literature and unpublished studies including national entomological surveys and expert networks. We describe all data collection processes, as well as geo-positioning methods, database management and quality-control procedures. This is the first comprehensive global database of Ae. aegypti and Ae. albopictus occurrence, consisting of 19,930 and 22,137 geo-positioned occurrence records respectively. Both datasets can be used for a variety of mapping and spatial analyses of the vectors and, by inference, the diseases they transmit.

  1. Some aspects of AE application in tool condition monitoring

    PubMed

    Jemielniak

    2000-03-01

    Acoustic emission (AE) is rather a well-known form of non-destructive testing. In the last few years the technology of the AE measurement has been expanded to cover the area of tool condition monitoring. The paper presents some experience of Warsaw University of Technology (WUT) in such applications of AE. It provides an interpretation of common AE signal distortions and possible solutions to avoid them. Furthermore, a characteristic study of several different AE and ultrasonic sensors being used in WUT is furnished. Evaluation of the applicability of some basic measures of acoustic emission for tool condition monitoring is also presented in the paper. Finally paper presents a method of the catastrophic tool failure detection in turning, which uses symptoms other than the direct magnitude AERMS signal. The method is based on the statistical analysis of the distributions of the AERMS signal.

  2. AE-941 (Neovastat): a novel multifunctional antiangiogenic compound.

    PubMed

    Gingras, D; Batist, G; Béliveau, R

    2001-10-01

    AE-941 (Neovastat) is a naturally occurring product extracted from cartilage and has antiangiogenic properties. It has reached Phase III clinical trial evaluation for the treatment of solid tumors (non-small cell lung cancer and renal cell carcinoma) and a pivotal Phase II clinical trial in multiple myeloma is ongoing. AE-941 inhibits several steps of the angiogenesis process, including matrix metalloproteinase activities and VEGF signaling pathways. Moreover, AE-941 induces endothelial cell apoptosis and tissue-type plasminogen activator activity, thus suggesting that it is a multifunctional antiangiogenic drug. Results from Phase I/II clinical trials indicate that AE-941, given orally, is well tolerated. Moreover, the median survival time in patients with renal cell carcinoma and non-small cell lung cancer was significantly longer in patients receiving high doses of AE-941 compared to low doses.

  3. Expression of metastasis suppressor gene AES driven by a Yin Yang (YY) element in a CpG island promoter and transcription factor YY2.

    PubMed

    Kakizaki, Fumihiko; Sonoshita, Masahiro; Miyoshi, Hiroyuki; Itatani, Yoshiro; Ito, Shinji; Kawada, Kenji; Sakai, Yoshiharu; Taketo, M Mark

    2016-11-01

    We recently found that the product of the AES gene functions as a metastasis suppressor of colorectal cancer (CRC) in both humans and mice. Expression of amino-terminal enhancer of split (AES) protein is significantly decreased in liver metastatic lesions compared with primary colon tumors. To investigate its downregulation mechanism in metastases, we searched for transcriptional regulators of AES in human CRC and found that its expression is reduced mainly by transcriptional dysregulation and, in some cases, by additional haploidization of its coding gene. The AES promoter-enhancer is in a typical CpG island, and contains a Yin-Yang transcription factor recognition sequence (YY element). In human epithelial cells of normal colon and primary tumors, transcription factor YY2, a member of the YY family, binds directly to the YY element, and stimulates expression of AES. In a transplantation mouse model of liver metastases, however, expression of Yy2 (and therefore of Aes) is downregulated. In human CRC metastases to the liver, the levels of AES protein are correlated with those of YY2. In addition, we noticed copy-number reduction for the AES coding gene in chromosome 19p13.3 in 12% (5/42) of human CRC cell lines. We excluded other mechanisms such as point or indel mutations in the coding or regulatory regions of the AES gene, CpG methylation in the AES promoter enhancer, expression of microRNAs, and chromatin histone modifications. These results indicate that Aes may belong to a novel family of metastasis suppressors with a CpG-island promoter enhancer, and it is regulated transcriptionally.

  4. Dense surface seismic data confirm non-double-couple source mechanisms induced by hydraulic fracturing

    USGS Publications Warehouse

    Pesicek, Jeremy; Cieślik, Konrad; Lambert, Marc-André; Carrillo, Pedro; Birkelo, Brad

    2016-01-01

    We have determined source mechanisms for nine high-quality microseismic events induced during hydraulic fracturing of the Montney Shale in Canada. Seismic data were recorded using a dense regularly spaced grid of sensors at the surface. The design and geometry of the survey are such that the recorded P-wave amplitudes essentially map the upper focal hemisphere, allowing the source mechanism to be interpreted directly from the data. Given the inherent difficulties of computing reliable moment tensors (MTs) from high-frequency microseismic data, the surface amplitude and polarity maps provide important additional confirmation of the source mechanisms. This is especially critical when interpreting non-shear source processes, which are notoriously susceptible to artifacts due to incomplete or inaccurate source modeling. We have found that most of the nine events contain significant non-double-couple (DC) components, as evident in the surface amplitude data and the resulting MT models. Furthermore, we found that source models that are constrained to be purely shear do not explain the data for most events. Thus, even though non-DC components of MTs can often be attributed to modeling artifacts, we argue that they are required by the data in some cases, and can be reliably computed and confidently interpreted under favorable conditions.

  5. Chandra High Energy Transmission Grating Spectrum of AE Aquarii

    NASA Astrophysics Data System (ADS)

    Mauche, Christopher W.

    2010-03-01

    The nova-like cataclysmic binary AE Aqr was observed for over two binary orbits in 2005 August with the High-Energy Transmission Grating onboard the Chandra X-ray Observatory. The resulting spectrum is reasonably well fit by an optically thin multi-temperature thermal plasma model with a Gaussian emission measure distribution that peaks at log T (K)=7.16, has a width sigma=0.4, an Fe abundance equal to 0.44 times solar, other metal abundances equal to 0.76 times solar, an emission measure EM=8.0x1053 cm-3, and a 0.5-10 keV X-ray luminosity LX=1.1x1031 erg s-1. Based on the f/(i+r) flux ratios of the He alpha triplets of N VI, O VII, Ne IX, Mg XI, and Si XIII in the XMM-Newton RGS and Chandra HETG spectra, we find that either the electron density of the plasma increases with temperature by over three orders of magnitude, from ne 6x1010 cm-3 for N VI to ne 1x1014 cm-3 for Si XIII, and/or the plasma is significantly affected by photoexcitation. The radial velocity of the X-ray emission lines varies on the white dwarf spin phase, with two oscillations per spin cycle and an amplitude K 160 km s-1 . These results appear to be inconsistent with the recent models of Itoh et al., Ikhsanov, and Venter & Meintjes of an extended, low-density source of X-rays in AE Aqr, but instead support earlier models in which the dominant source of X-rays is of high density and/or in close proximity to the white dwarf. Support for this work was provided by NASA through Chandra Award Number GO5-6020X issued by the Chandra X-ray Observatory Center, which is operated by the Smithsonian Astrophysical Observatory for and on behalf of NASA under contract NAS8-03060. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  6. Gene flow between wheat and wild relatives: empirical evidence from Aegilops geniculata, Ae. neglecta and Ae. triuncialis

    PubMed Central

    Arrigo, Nils; Guadagnuolo, Roberto; Lappe, Sylvain; Pasche, Sophie; Parisod, Christian; Felber, François

    2011-01-01

    Gene flow between domesticated species and their wild relatives is receiving growing attention. This study addressed introgression between wheat and natural populations of its wild relatives (Aegilops species). The sampling included 472 individuals, collected from 32 Mediterranean populations of three widespread Aegilops species (Aegilops geniculata, Ae. neglecta and Ae. triuncialis) and compared wheat field borders to areas isolated from agriculture. Individuals were characterized with amplified fragment length polymorphism fingerprinting, analysed through two computational approaches (i.e. Bayesian estimations of admixture and fuzzy clustering), and sequences marking wheat-specific insertions of transposable elements. With this combined approach, we detected substantial gene flow between wheat and Aegilops species. Specifically, Ae. neglecta and Ae. triuncialis showed significantly more admixed individuals close to wheat fields than in locations isolated from agriculture. In contrast, little evidence of gene flow was found in Ae. geniculata. Our results indicated that reproductive barriers have been regularly bypassed during the long history of sympatry between wheat and Aegilops. PMID:25568015

  7. Chandra High-Energy Transmission Grating Spectrum of AE Aquarii

    NASA Astrophysics Data System (ADS)

    Mauche, Christopher W.

    2009-11-01

    & Meintjes of an extended, low-density source of X-rays in AE Aqr, but instead support earlier models in which the dominant source of X-rays is of high density and/or in close proximity to the white dwarf.

  8. Characterization of Aes nuclear foci in colorectal cancer cells

    PubMed Central

    Itatani, Yoshiro; Sonoshita, Masahiro; Kakizaki, Fumihiko; Okawa, Katsuya; Stifani, Stefano; Itoh, Hideaki; Sakai, Yoshiharu; Taketo, M. Mark

    2016-01-01

    Amino-terminal enhancer of split (Aes) is a member of Groucho/Transducin-like enhancer (TLE) family. Aes is a recently found metastasis suppressor of colorectal cancer (CRC) that inhibits Notch signalling, and forms nuclear foci together with TLE1. Although some Notch-associated proteins are known to form subnuclear bodies, little is known regarding the dynamics or functions of these structures. Here, we show that Aes nuclear foci in CRC observed under an electron microscope are in a rather amorphous structure, lacking surrounding membrane. Investigation of their behaviour during the cell cycle by time-lapse cinematography showed that Aes nuclear foci dissolve during mitosis and reassemble after completion of cytokinesis. We have also found that heat shock cognate 70 (HSC70) is an essential component of Aes foci. Pharmacological inhibition of the HSC70 ATPase activity with VER155008 reduces Aes focus formation. These results provide insight into the understanding of Aes-mediated inhibition of Notch signalling. PMID:26229111

  9. Cause of the exceptionally high AE average for 2003

    NASA Astrophysics Data System (ADS)

    Prestes, A.

    2012-04-01

    In this work we focus on the year of 2003 when the AE index was extremely high (AE=341nT, with peak intensity more than 2200nT), this value is almost 100 nT higher when compared with others years of the cycle 23. Interplanetary magnetic field (IMF) and plasma data are compared with geomagnetic AE and Dst indices to determine the causes of exceptionally high AE average value. Analyzing the solar wind parameters we found that the annual average speed value was extremely high, approximately 542 km/s (peak value ~1074 km/s). These values were due to recurrent high-speed solar streams from large coronal holes, which stretch to the solar equator, and low-latitude coronal holes, which exist for many solar rotations. AE was found to increase with increasing solar wind speed and decrease when solar wind speed decrease. The cause of the high AE activity during 2003 is the presence of the high-speed corotating streams that contain large-amplitude Alfvén waves throughout the streams, which resulted in a large number of HILDCAAs events. When plasma and field of solar wind impinge on Earth's magnetosphere, the southward field turnings associated with the wave fluctuations cause magnetic reconnection and consequential high levels of AE activity and very long recovery phases on Dst, sometimes lasting until the next stream arrives.

  10. Varied skill set needed for AE (D) role.

    PubMed

    Baillie, Jonathan

    2011-05-01

    IHEEM's AE (D) Panel plays an important role in managing and administering the UK's only official register of such specialist personnel, and indeed it is the Panel that selects qualified candidates for registration, interviews those considered "the right material", and confers registered AE (D) status on those that Panel members feel have the right combination of professional experience and expertise, academic qualifications, and knowledge, to fulfil the role. HEJ editor Jonathan Baillie examines the history of the AE (D) register and Panel, and talks to the latter's chairman, Eric Thomas, to find out more.

  11. The global joule heat production rate and the AE index

    NASA Technical Reports Server (NTRS)

    Wei, S.; Ahn, B.-H.; Akasofu, S.-I.

    1985-01-01

    The degree of accuracy with which the AE index may be used as a measure of the joule heat production rate is evaluated for a typical substorm event on March 18, 1978, by estimating the global joule heat production rate as a function of time on the basis of data obtained from the IMS's six meridian chains. It is found that, although the AE index is statistically linearly related to the global joule heat production rate, caution is required when one assumes that details of AE index time variations during individual events are representative of those of the joule heat production rate.

  12. Performance evaluation of the Fiber Bragg Grating (FBG) sensing device and comparison with piezoelectric sensors for AE detection

    NASA Astrophysics Data System (ADS)

    Zhang, Chuang; Bond, Leonard J.

    2017-02-01

    Structural health monitoring (SHM) of engineering structures in service has assumed a significant role in assessing their safety and integrity. Several sensing modalities have been developed to monitor cracking, using acoustic emission (AE). Piezoelectric sensors are commonly used in AE systems, however, for some applications there are limitations and challenges. One alternative approach that is being investigated is using Fiber Bragg Grating (FBG) sensors which have emerged as a reliable, in situ and nondestructive tool in some applications for monitoring and diagnostics in large-scale structure. The main objective of this work is to evaluate and compare the AE sensing characteristics for FBG and piezoelectric sensors. A ball drop impact is used as the source for generating waves in an Aluminum plate. The source repeatability was verified and a 4-channel FBG AE detection device was used to compare with the response of PZT sensors, investigating amplitude and frequency response which can indicate sensitivity. The low sensitivity and slow sampling rate are identified, for the unit investigated, as the main factors limiting FBG engineering AE applications.

  13. Pulsational stability of the SX Phe star AE UMa

    NASA Astrophysics Data System (ADS)

    Pena, J. H.; Renteria, A.; Villarreal, C.; Pina, D. S.; Soni, A. A.; Guillen, J.; Vargas, K.; Trejo, O.

    2016-11-01

    From newly determined times of maxima of the SX Phe star AE UMa and a compilation of previous times of maxima, we were able to determine the nature of this star. With uv photometry we determined its physical parameters.

  14. 22 CFR 120.30 - The Automated Export System (AES).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Commerce, Bureau of Census, electronic filing of export information. The AES shall serve as the primary...). Also, requests for special reporting may be made by DDTC on a case-by-case basis, (e.g.,...

  15. Generating Lookup Tables from the AE9/AP9 Models

    DTIC Science & Technology

    2015-06-16

    21 iv Figures Figure 1. Visualization of AE9 integral 1 MeV...by The Aerospace Corporation. SOAP allows for a visualization of the 3D data table in 2D slices, as shown in Figure 1, and also allows for analysis of...and solar cycle. 2 Figure 1. Visualization of AE9 integral 1 MeV electrons using SOAP and a static 3D table containing data generated from

  16. AE-5 end of mission tests report. [Explorer 55 satellite

    NASA Technical Reports Server (NTRS)

    Stengle, T. H.; Kissel, F.; Schaefer, J.; Kalil, F.

    1981-01-01

    A spin up test and a TDRS tracking simulation were performed on the AE-5 spacecraft before its end of mission. the spin up test showed that the Body Horizon Scanner could be successfully used on other spacecraft with spin rates up to 10 RPM. the TDRS tracking simulation showed that an AE-5 type attitude control system could be successfully used to point the spacecraft towards a TDRS for the purpose of transmitting/relaying data via the TDRS.

  17. AE analysis in developing the Hot Fractured Rock geothermal power in Australia

    NASA Astrophysics Data System (ADS)

    Aoyagi, Y.; Kaieda, H.; Asanuma, H.; Wyborn, D.

    2004-12-01

    The hot fractured rock (HFR) geothermal power is being developed in Cooper Basin, South Australia since 2002. HFR geothermal power is one of natural energy acquiring systems, in which water is pumped into hot, crystalline rock via an injection well, becomes superheated as it flows through open joints in the hot rock reservoir, and is returned through production wells. At the surface, the useful heat is extracted by conventional processes, and the same water is re-circulated to mine more heat. Such hot granites are buried beneath 3.7 km of insulating sedimentary rocks at the site. The temperature of the granites reaches 250_E#381; or more. The first injection well Habanero#1 was drilled 720m into the granite, and a reservoir was made by the hydraulic fracturing in the vicinity of the well bottom (4421m in depth) in 2003. During the hydraulic fracturing many acoustic emissions (AE) were generated. We observed the AE activity using seismic network deployed in 8 wells around Habanero#1 to evaluate the reservoir. Total of 12000 or more AE were observed during the fracturing period from November to December, 2003. Although the AE hypocenters were located in the south side of the well at the initial stage, they finally distributed N-S to NE-SW direction at about 3km in diameter. The magnitude of the AE ranges M-2 to M1 for most events, but several felt earthquakes as maximum size of M3.7 were also generated. The hypocenters of the larger 12 events (> M2.5) were located by the seismic network of Geoscience Australia. The mechanism solution of these large events is basically E-W compression type, and it almost agrees to the regional stress estimated by borehole breakout in wells in the area. The AE generation property will help to understand earthquake dynamics and mechanics since it is controlled by hydraulic pressure. We will mainly discuss the relation between the generated regional energy and the mechanism solution of the events.

  18. A pipeline to extract drug-adverse event pairs from multiple data sources

    PubMed Central

    2014-01-01

    Background Pharmacovigilance aims to uncover and understand harmful side-effects of drugs, termed adverse events (AEs). Although the current process of pharmacovigilance is very systematic, the increasing amount of information available in specialized health-related websites as well as the exponential growth in medical literature presents a unique opportunity to supplement traditional adverse event gathering mechanisms with new-age ones. Method We present a semi-automated pipeline to extract associations between drugs and side effects from traditional structured adverse event databases, enhanced by potential drug-adverse event pairs mined from user-comments from health-related websites and MEDLINE abstracts. The pipeline was tested using a set of 12 drugs representative of two previous studies of adverse event extraction from health-related websites and MEDLINE abstracts. Results Testing the pipeline shows that mining non-traditional sources helps substantiate the adverse event databases. The non-traditional sources not only contain the known AEs, but also suggest some unreported AEs for drugs which can then be analyzed further. Conclusion A semi-automated pipeline to extract the AE pairs from adverse event databases as well as potential AE pairs from non-traditional sources such as text from MEDLINE abstracts and user-comments from health-related websites is presented. PMID:24559132

  19. Source location and mechanism analysis of an earthquake triggered by the 2016 Kumamoto, southwestern Japan, earthquake

    NASA Astrophysics Data System (ADS)

    Nakamura, Takeshi; Aoi, Shin

    2017-01-01

    The 2016 Kumamoto earthquake ( Mw 7.0) occurred in the central part of Kyushu Island, southwestern Japan, on April 16, 2016. The mainshock triggered an event of maximum acceleration 700 gal that caused severe damage to infrastructure and thousands of homes. We investigate the source location of the triggered event, and the timing of large energy release, by employing the back-projection method for strong-motion network data. The optimal location is estimated to be [33.2750°, 131.3575°] (latitude, longitude) at a depth of 5 km, which is 80 km northeast of the epicenter of the mainshock. The timing is 33.5 s after the origin time of the mainshock. We also investigate the source mechanism by reproducing observed displacement waveforms at a near-source station. The waveforms at smaller-sized events, convolved with the source time function of a pulse width 1 s, are similar to the signature of the observed waveforms of the triggered event. The observations are also reproduced by synthetic waveforms for a normal-fault mechanism and a normal-fault with strike-slip components at the estimated locations. Although our approach does not constrain the strike direction well, our waveform analysis indicates that the triggered earthquake occurred near the station that observed the strong motions, primarily via a normal-fault mechanism or a normal-fault with strike-slip components.[Figure not available: see fulltext.

  20. Oligomeric structure of bAE3 protein.

    PubMed

    Pushkin, A V; Tsuprun, V L; Abuladze, N K; Newman, D; Kurtz, I

    2000-12-01

    The "brain" form of the anion exchanger protein 3 (bAE3) has been purified to homogeneity from the rabbit kidney by differential centrifugation and immunoaffinity chromatography. A single protein band of approximately 165 kDa was detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting. Monomers, dimers (a major component), and a higher oligomeric form (apparently tetramers) were found after oxidative cross-linking of purified bAE3. The largest form of bAE3 was separated from dimers and monomers by sucrose gradient centrifugation and was studied by transmission electron microscopy to confirm a tetrameric structure. Two main types of bAE3 images were detected, round (approximately 11-14 nm) and square-shaped (approximately 12 x 12 nm). Image analysis revealed fourfold rotational symmetry of both the round and square-shaped images, indicating that bAE3 consists of multiples of 4 subunits. We conclude that bAE3 in Triton X-100 solution is predominantly a mixture of dimers and tetramers with a smaller amount of monomers.

  1. Radio continuum observations of the Herbig Ae/Be stars HD 163296 and HR 5999

    NASA Technical Reports Server (NTRS)

    Brown, D. A.; Perez, M. R.; Yusef-Zadeh, F.

    1993-01-01

    Very Large Array (VLA) observations of the two bright Herbig Ae/Be stars HD 163296 and HR 5999 have been carried out at lambda 3.6 and 20 cm. We report the detection of a radio source at lambda 3.6 cm that may be associated with HD 163296. From the peak flux density of 0.39 mJy/beam area, we estimate a mass-loss rate of 1.8 x 10(exp -8) solar mass/yr if the flux is due to free-free emission in an ionized wind with spherical symmetry, assuming a terminal wind velocity of 200 km/s. HR 5999 was not detected at either wavelength. We discuss the results in terms of the stellar-driven and accretion-driven scenarios for line and wind formation in Herbig Ae/Be stars.

  2. Laser Guide Star Adaptive Optics Imaging Polarimetry of Herbig Ae/Be Stars

    NASA Astrophysics Data System (ADS)

    Perrin, Marshall D.; Graham, James R.; Kalas, Paul; Lloyd, James P.; Max, Claire E.; Gavel, Donald T.; Pennington, Deanna M.; Gates, Elinor L.

    2004-02-01

    We have used laser guide star adaptive optics and a near-infrared dual-channel imaging polarimeter to observe light scattered in the circumstellar environment of Herbig Ae/Be stars on scales of 100 to 300 astronomical units. We revealed a strongly polarized, biconical nebula 10 arc seconds (6000 astronomical units) in diameter around the star LkHα 198 and also observed a polarized jet-like feature associated with the deeply embedded source LkHα 198-IR. The star LkHα 233 presents a narrow, unpolarized dark lane consistent with an optically thick circumstellar disk blocking our direct view of the star. These data show that the lower-mass T Tauri and intermediate mass Herbig Ae/Be stars share a common evolutionary sequence.

  3. Energy transmission and power sources for mechanical circulatory support devices to achieve total implantability.

    PubMed

    Wang, Jake X; Smith, Joshua R; Bonde, Pramod

    2014-04-01

    Left ventricular assist device therapy has radically improved congestive heart failure survival with smaller rotary pumps. The driveline used to power today's left ventricular assist devices, however, continues to be a source of infection, traumatic damage, and rehospitalization. Previous attempts to wirelessly power left ventricular assist devices using transcutaneous energy transfer systems have been limited by restrictions on separation distance and alignment between the transmit and receive coils. Resonant electrical energy transfer allows power delivery at larger distances without compromising safety and efficiency. This review covers the efforts to wirelessly power mechanical circulatory assist devices and the progress made in enhancing their energy sources.

  4. Source Mechanism Inversion of Very Long Period Strombolian Eruption Signals at Mount Erebus, Antarctica

    NASA Astrophysics Data System (ADS)

    McNamara, S. K.; Aster, R. C.; Kyle, P.

    2003-12-01

    Oscillatory, repeatable, very-long-period signals (25 s > T > 5 s) associated with strombolian eruptions of Mt. Erebus, Antarctica have been recorded by near-field broadband seismometers for several years. The eruptions are typically single, large (up to 10-m diameter), explosive bubble decompressions occurring at the surface of a phonolitic lava lake that eviscerate the lake to a depth of approximately 10 m. Associated VLP signals begin several seconds before, and continue for several minutes after, eruptions, becoming indistinguishable as lava lake recovery is achieved. We have performed waveform inversions of high signal-to-noise stacks to recover equivalent point-source moment tensor parameters and associated source time functions. Solutions are obtained by minimizing 2-norm residuals between synthetic and three-component observed seismograms using a modified version of the iterative inversion technique of Lay and Wallace (1995). We allow for varying degrees of source freedom, ranging from pure Mogi (explosive/implosive) to a complete set of six double couples and three single forces. Results suggest a shallow (<= 200 m) source region and negligible non-volumetric couple and single-force terms. During the VLP coda, the source model evolves in time towards an increasingly subhorizontal resonating crack. We will address the accuracy of using simple half-space Green's functions in such inversions and discuss source mechanism possibilities in terms of slow elastic, dynamic recharge, and other processes.

  5. The L7Ae protein binds to two kink-turns in the Pyrococcus furiosus RNase P RNA

    PubMed Central

    Lai, Stella M.; Lai, Lien B.; Foster, Mark P.; Gopalan, Venkat

    2014-01-01

    The RNA-binding protein L7Ae, known for its role in translation (as part of ribosomes) and RNA modification (as part of sn/oRNPs), has also been identified as a subunit of archaeal RNase P, a ribonucleoprotein complex that employs an RNA catalyst for the Mg2+-dependent 5′ maturation of tRNAs. To better understand the assembly and catalysis of archaeal RNase P, we used a site-specific hydroxyl radical-mediated footprinting strategy to pinpoint the binding sites of Pyrococcus furiosus (Pfu) L7Ae on its cognate RNase P RNA (RPR). L7Ae derivatives with single-Cys substitutions at residues in the predicted RNA-binding interface (K42C/C71V, R46C/C71V, V95C/C71V) were modified with an iron complex of EDTA-2-aminoethyl 2-pyridyl disulfide. Upon addition of hydrogen peroxide and ascorbate, these L7Ae-tethered nucleases were expected to cleave the RPR at nucleotides proximal to the EDTA-Fe–modified residues. Indeed, footprinting experiments with an enzyme assembled with the Pfu RPR and five protein cofactors (POP5, RPP21, RPP29, RPP30 and L7Ae–EDTA-Fe) revealed specific RNA cleavages, localizing the binding sites of L7Ae to the RPR's catalytic and specificity domains. These results support the presence of two kink-turns, the structural motifs recognized by L7Ae, in distinct functional domains of the RPR and suggest testable mechanisms by which L7Ae contributes to RNase P catalysis. PMID:25361963

  6. Source Mechanisms of Earthquakes at the Geysers Geothermal Region Using a Hierarchical Bayesian Approach

    NASA Astrophysics Data System (ADS)

    Burky, A.; Mustac, M.; Tkalcic, H.; Dreger, D. S.

    2015-12-01

    The Geysers geothermal region in northern California is a valuable resource for the production of geothermal electric power. Injection of water into the reservoir is necessary to maintain pressure and causes an increase in the number of earthquakes per day, but their source mechanisms are not well understood (Johnson, 2015). Previous studies of source mechanisms for events in the Geysers have identified a large number of events with significant isotropic and compensated linear vector dipole components. These source complexities most likely arise from the presence of pressurized liquids and gases, as well as temperature changes, at depth. The existence of non-double couple components in volcanic and geothermal environments has been extensively documented by previous studies, but it has also been shown that spurious components might occur due to a range of factors such as an inadequate knowledge of Earth structure and earthquake location, or noisy waveform data. Therefore, it is not entirely surprising that non-double-couple components from different source studies, each following a different experimental method and using different data types, do not agree well (e.g. Guilhem et al., 2014). The assessment of the solution robustness is critical for the physical interpretation of source mechanisms.Here, we apply a hierarchical Bayesian approach (Mustac and Tkalcic, 2015) to waveform data from M>4.5 events in the Geysers in order to produce moment tensor "solutions" and simultaneously estimate their robustness. By using a Bayesian inversion, we quantify the uncertainties from an ensemble of probable solutions instead of a single optimized solution and sample solutions at a range of centroid locations. Moreover, the hierarchical approach allows noise in the data to be sampled as a free parameter in the inversion. A rigorous approach in accounting for the data correlated noise covariance matrix prevents "over-interpretation" of noise, thus avoiding erroneous solutions. We

  7. Point-source idealization in classical field theories. II. Mechanical energy losses from electromagnetic radiation reaction

    NASA Astrophysics Data System (ADS)

    Kates, Ronald E.; Rosenblum, Arnold

    1982-05-01

    This paper compares the mechanical energy losses due to electromagnetic radiation reaction on a two-particle, slow-motion system, as calculated from (1) the method of matched asymptotic expansions and (2) the Lorentz-Dirac equation, which assumes point sources. The matching derivation of the preceding paper avoided the assumption of a δ-function source by using Reissner-Nordström matching zones. Despite the differing mathematical assumptions of the two methods, their results are in agreement with each other and with the electromagnetic-field energy losses calculated by the evaluation of flux integrals. Our purpose is eventually to analyze Rosenblum's use of point sources as a possible cause of disagreement between the analogous calculations of gravitational radiation on a slow-motion system of two bodies. We begin with the simpler electromagnetic problem.

  8. An evaluation of manual and mechanical methods to identify Candida spp. from human and animal sources.

    PubMed

    Oliveira, Geraldo dos Santos; Ribeiro, Elizabeth Teixeira; Baroni, Francisco de Assis

    2006-01-01

    To compare two yeast identification methods, i. e, the manual and the VITEK mechanical methods, 62 clinical samples from hemocultures and animal sources were analyzed. After identification as Candida yeasts by the VITEK method, the strains were recharacterized using manual assimilation methods and sugar fermentation tests. Our findings reveal 58% concurrent identification between the two methods for animal strains, and 51% for human hemoculture strains.

  9. Source Mechanism of Soputan Volcano based on Seismic and Magnetic Data

    NASA Astrophysics Data System (ADS)

    Suparman, Y.; Pamitro, Y.; Kriswati, E.; Akbar, W.

    2012-12-01

    Moment tensor analysis have been conducted to understand the source mechanism in Soputan Volcano during October - November 2010 period. The record shows shallow earthquakes with frequency about 5 - 9 Hz. Polarity distribution of P-wave first onset indicates that the recorded earthquakes are predominated by earthquakes where almost at all stations have same direction of P-wave first motions. In this article, the seismic source mechanism is described as the second derivative of moment tensor, approached with first motion amplitude inversion of P-wave at some seismic stations. The result of moment tensor decomposition are predominated by earthquakes with big percentage in ISO and CLVD component. Focal mechanism shows that the recorded earthquakes have the same strike in Northeast-Southwest direction with dip about 40 - 60. Inversion modeling, using weighted-damped-least-squares method, of magnetic profile shows geometry which interpreted as a fault structure. The sources of the high frequency shallow earthquakes are in the form of tensile-shear cracks or a combination between crack and tensile faulting.

  10. Driving mechanism and sources of groundwater nitrate contamination in the rapidly urbanized region of south China.

    PubMed

    Zhang, Qianqian; Sun, Jichao; Liu, Jingtao; Huang, Guanxing; Lu, Chuan; Zhang, Yuxi

    2015-11-01

    Nitrate contamination of groundwater has become an environmental problem of widespread concern in China. We collected 899 groundwater samples from a rapidly urbanized area, in order to identify the main sources and driving mechanisms of groundwater nitrate contamination. The results showed that the land use has a significant effect on groundwater nitrate concentration (P<0.001). Landfill leakage was an important source of nitrate in groundwater in the PRD (Pearl River Delta) region, since landfill yielded the highest nitrate concentration (38.14 mg/L) and the highest ratio of exceeded standard (42.50%). In this study, the driving mechanism of groundwater nitrate contamination was determined to be urban construction and the secondary and tertiary industrial development, and population growth. This study revealed that domestic wastewater and industrial wastewater were the main sources of groundwater nitrate pollution. Therefore, the priority method for relieving groundwater nitrate contamination is to control the random discharge of domestic and industrial wastewater in regions undergoing rapid urbanization. Capsule abstract. The main driving mechanism of groundwater nitrate contamination was determined to be urban construction and the secondary and tertiary industrial development, and population growth.

  11. Driving mechanism and sources of groundwater nitrate contamination in the rapidly urbanized region of south China

    NASA Astrophysics Data System (ADS)

    Zhang, Qianqian; Sun, Jichao; Liu, Jingtao; Huang, Guanxing; Lu, Chuan; Zhang, Yuxi

    2015-11-01

    Nitrate contamination of groundwater has become an environmental problem of widespread concern in China. We collected 899 groundwater samples from a rapidly urbanized area, in order to identify the main sources and driving mechanisms of groundwater nitrate contamination. The results showed that the land use has a significant effect on groundwater nitrate concentration (P < 0.001). Landfill leakage was an important source of nitrate in groundwater in the PRD (Pearl River Delta) region, since landfill yielded the highest nitrate concentration (38.14 mg/L) and the highest ratio of exceeded standard (42.50%). In this study, the driving mechanism of groundwater nitrate contamination was determined to be urban construction and the secondary and tertiary industrial development, and population growth. This study revealed that domestic wastewater and industrial wastewater were the main sources of groundwater nitrate pollution. Therefore, the priority method for relieving groundwater nitrate contamination is to control the random discharge of domestic and industrial wastewater in regions undergoing rapid urbanization. Capsule abstract. The main driving mechanism of groundwater nitrate contamination was determined to be urban construction and the secondary and tertiary industrial development, and population growth.

  12. The impact of runoff generation mechanisms on the location of critical source areas

    USGS Publications Warehouse

    Lyon, S.W.; McHale, M.R.; Walter, M.T.; Steenhuis, T.S.

    2006-01-01

    Identifying phosphorus (P) source areas and transport pathways is a key step in decreasing P loading to natural water systems. This study compared the effects of two modeled runoff generation processes - saturation excess and infiltration excess - on total phosphorus (TP) and soluble reactive phosphorus (SRP) concentrations in 10 catchment streams of a Catskill mountain watershed in southeastern New York. The spatial distribution of runoff from forested land and agricultural land was generated for both runoff processes; results of both distributions were consistent with Soil Conservation Service-Curve Number (SCS-CN) theory. These spatial runoff distributions were then used to simulate stream concentrations of TP and SRP through a simple equation derived from an observed relation between P concentration and land use; empirical results indicate that TP and SRP concentrations increased with increasing percentage of agricultural land. Simulated TP and SRP stream concentrations predicted for the 10 catchments were strongly affected by the assumed runoff mechanism. The modeled TP and SRP concentrations produced by saturation excess distribution averaged 31 percent higher and 42 percent higher, respectively, than those produced by the infiltration excess distribution. Misrepresenting the primary runoff mechanism could not only produce erroneous concentrations, it could fail to correctly locate critical source areas for implementation of best management practices. Thus, identification of the primary runoff mechanism is critical in selection of appropriate models in the mitigation of nonpoint source pollution. Correct representation of runoff processes is also critical in the future development of biogeochemical transport models, especially those that address nutrient fluxes.

  13. Localization of quenches and mechanical disturbances in the Mu2e transport solenoid prototype using acoustic emission technique

    DOE PAGES

    Marchevsky, M.; Ambrosio, G.; Lamm, M.; ...

    2016-02-12

    Acoustic emission (AE) detection is a noninvasive technique allowing the localization of the mechanical events and quenches in superconducting magnets. Application of the AE technique is especially advantageous in situations where magnet integrity can be jeopardized by the use of voltage taps or inductive pickup coils. As the prototype module of the transport solenoid (TS) for the Mu2e experiment at Fermilab represents such a special case, we have developed a dedicated six-channel AE detection system and accompanying software aimed at localizing mechanical events during the coil cold testing. The AE sensors based on transversely polarized piezoceramic washers combined with cryogenicmore » preamplifiers were mounted at the outer surface of the solenoid aluminum shell, with a 60° angular step around the circumference. Acoustic signals were simultaneously acquired at a rate of 500 kS/s, prefiltered and sorted based on their arrival time. Next, based on the arrival timing, angular and axial coordinates of the AE sources within the magnet structure were calculated. Furthermore, we present AE measurement results obtained during cooldown, spot heater firing, and spontaneous quenching of the Mu2e TS module prototype and discuss their relevance for mechanical stability assessment and quench localization.« less

  14. Localization of quenches and mechanical disturbances in the Mu2e transport solenoid prototype using acoustic emission technique

    SciTech Connect

    Marchevsky, M.; Ambrosio, G.; Lamm, M.; Tartaglia, M. A.; Lopes, M. L.

    2016-02-12

    Acoustic emission (AE) detection is a noninvasive technique allowing the localization of the mechanical events and quenches in superconducting magnets. Application of the AE technique is especially advantageous in situations where magnet integrity can be jeopardized by the use of voltage taps or inductive pickup coils. As the prototype module of the transport solenoid (TS) for the Mu2e experiment at Fermilab represents such a special case, we have developed a dedicated six-channel AE detection system and accompanying software aimed at localizing mechanical events during the coil cold testing. The AE sensors based on transversely polarized piezoceramic washers combined with cryogenic preamplifiers were mounted at the outer surface of the solenoid aluminum shell, with a 60° angular step around the circumference. Acoustic signals were simultaneously acquired at a rate of 500 kS/s, prefiltered and sorted based on their arrival time. Next, based on the arrival timing, angular and axial coordinates of the AE sources within the magnet structure were calculated. Furthermore, we present AE measurement results obtained during cooldown, spot heater firing, and spontaneous quenching of the Mu2e TS module prototype and discuss their relevance for mechanical stability assessment and quench localization.

  15. Source Mechanism of Tiny Long-Period Events at Mount St. Helens in July 2005

    NASA Astrophysics Data System (ADS)

    Matoza, R. S.; Chouet, B. A.; Dawson, P. B.; Shearer, P. M.; Haney, M. M.; Waite, G. P.; Moran, S. C.; Mikesell, T. D.

    2015-12-01

    Long-period (LP, 0.5-5 Hz) seismicity is a recognized signature of unrest and eruption at volcanoes worldwide. The characteristic seismicity during the sustained dome-building phase of the 2004-2008 eruption of Mount St. Helens (MSH), USA was cyclic LP "drumbeating". However, accompanying the LP drumbeating was a near-continuous, randomly occurring series of tiny LP seismic events (LP "subevents"), which may hold important additional information on the mechanism of seismogenesis at restless volcanoes. We employ template matching, phase-weighted stacking, and full-waveform inversion to image the source mechanism of one multiplet of these LP subevents at MSH in July 2005. We apply network-based template matching to 8 days of continuous velocity waveform data from 29 June to 7 July 2005. We stack waveforms for high-quality triggers at each station and component, using a combination of linear and phase-weighted stacking to produce clean stacks for use in waveform inversion. The derived source mechanism points to the volumetric oscillation (~10 m3) of a subhorizontal crack located at shallow depth (~30 m) in an area to the south of Crater Glacier in the southern portion of the breached MSH crater. A possible excitation mechanism is the sudden condensation of metastable steam from a shallow pressurized hydrothermal system as it encounters cool meteoric water in the outer parts of the edifice.

  16. System for Multiplexing Acoustic Emission (AE) Instrumentation

    NASA Technical Reports Server (NTRS)

    Prosser, William H. (Inventor); Perey, Daniel F. (Inventor); Gorman, Michael R. (Inventor); Scales, Edgar F. (Inventor)

    2003-01-01

    An acoustic monitoring device has at least two acoustic sensors with a triggering mechanism and a multiplexing circuit. After the occurrence of a triggering event at a sensor, the multiplexing circuit allows a recording component to record acoustic emissions at adjacent sensors. The acoustic monitoring device is attached to a solid medium to detect the occurrence of damage.

  17. Sources of noise and vibration in a mechanical system with clearances

    SciTech Connect

    Akay, A.; Bengisu, M.T.

    1982-01-01

    Inherent in the design of any mechanism with moving parts is the requirement for clearances. In the case of an engine, this requirement is enhanced by the extremes of both load and temperature under which some parts are expected to function. Collision of the parts in these connections where clearances exist are influenced by transient combustion forces as well as inertial forces. Impacts in the joints of a system are a major source of sound, vibration and wear. The mechanism of sound generation follows the dynamic response of the system components. The resulting transient acoustic field is comprised of radiation from the forced and free vibrations of the system. Radiation due to inertial forces are generally of lower frequency whereas sounds produced by the impacts exhibit higher levels with higher spectral content. This study investigates the sound and vibration response of a four-bar mechanism in the absence of external forces.

  18. Source mechanism studies of earthquakes in the Ibero-Maghrebian region and their tectonic implications

    NASA Astrophysics Data System (ADS)

    Buforn, E.; Udías, A.; Pro, C.

    2016-10-01

    Seismicity of the Ibero-Maghrebian region includes the occurrence of shallow, intermediate depth, and very deep earthquakes. This is a very rare occurrence for a region not associated to an active subduction zone. Detailed studies of the source mechanism of these three types of earthquakes have been made possible through the collaboration with Prof. Madariaga. They give important information about the complex tectonic of the region. Shallow earthquakes at the west and east ends of the region have predominant reverse faulting with NW-SE trending horizontal pressure axes. The center part is the most tectonically complex. At the Strait of Gibraltar, there is a change on focal mechanisms from reverse faulting to strike-slip motion in northern Morocco, conserving the horizontal compression on NW-SE direction. In the Alboran Sea, mechanisms are of normal faulting with E-W trending horizontal tension axes, and in south Spain, mechanisms are of mixed solutions. The intermediate depth earthquakes (40-130 km) are located at both sides of the Strait of Gibraltar, at the western part distributed in E-W direction. The most important concentration, however, is located at the east of Gibraltar in a N-S trending thin vertical body and has different mechanisms. The very deep earthquakes (650 km) are concentrated at a small volume, and their mechanism corresponds to N-S vertical planes or horizontal ones. A tectonic model for the region is presented to explain the shallow, intermediate, and deep earthquakes.

  19. 77 FR 15098 - AES Hawaii, Inc.; Notice of Petition for Temporary Waiver

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-14

    ... Energy Regulatory Commission AES Hawaii, Inc.; Notice of Petition for Temporary Waiver Take notice that... (Commission) Rules of Practice and Procedure, 18 CFR 292.205(c), AES Hawaii, Inc. (AES Hawaii) filed a Request... on the island of Oauh, Hawaii. AES Hawaii makes such a request because of a forced boiler outage...

  20. High-energy X-Ray Detection of G359.89-0.08 (Sgr A-E): Magnetic Flux Tube Emission Powered by Cosmic Rays?

    NASA Astrophysics Data System (ADS)

    Zhang, Shuo; Hailey, Charles J.; Baganoff, Frederick K.; Bauer, Franz E.; Boggs, Steven E.; Craig, William W.; Christensen, Finn E.; Gotthelf, Eric V.; Harrison, Fiona A.; Mori, Kaya; Nynka, Melania; Stern, Daniel; Tomsick, John A.; Zhang, William W.

    2014-03-01

    We report the first detection of high-energy X-ray (E > 10 keV) emission from the Galactic center non-thermal filament G359.89-0.08 (Sgr A-E) using data acquired with the Nuclear Spectroscopic Telescope Array (NuSTAR). The bright filament was detected up to ~50 keV during a NuSTAR Galactic center monitoring campaign. The featureless power-law spectrum with a photon index Γ ≈ 2.3 confirms a non-thermal emission mechanism. The observed flux in the 3-79 keV band is FX = (2.0 ± 0.1) × 10-12 erg cm-2 s-1, corresponding to an unabsorbed X-ray luminosity LX = (2.6 ± 0.8) × 1034 erg s-1 assuming a distance of 8.0 kpc. Based on theoretical predictions and observations, we conclude that Sgr A-E is unlikely to be a pulsar wind nebula (PWN) or supernova remnant-molecular cloud (SNR-MC) interaction, as previously hypothesized. Instead, the emission could be due to a magnetic flux tube which traps TeV electrons. We propose two possible TeV electron sources: old PWNe (up to ~100 kyr) with low surface brightness and radii up to ~30 pc or MCs illuminated by cosmic rays (CRs) from CR accelerators such as SNRs or Sgr A*.

  1. High-Energy X-Ray Detection of G359.89-0.08 (SGR A-E): Magnetic Flux Tube Emission Powered by Cosmic Rays?

    NASA Technical Reports Server (NTRS)

    Zhang, Shuo; Hailey, Charles J.; Baganoff, Frederick K.; Bauer, Franz E.; Boggs, Steven E.; Craig, William W.; Christensen, Finn E.; Gotthelf, Eric V.; Harrison, Fiona A.; Mori, Kaya; Nynka, Melania; Stern, Daniel; Tomsick, John A; Zhang, Will

    2014-01-01

    We report the first detection of high-energy X-ray (E (is) greater than 10 keV) emission from the Galactic center non-thermal filament G359.89-0.08 (Sgr A-E) using data acquired with the Nuclear Spectroscopic Telescope Array (NuSTAR). The bright filament was detected up to approximately 50 keV during a NuSTAR Galactic center monitoring campaign. The featureless power-law spectrum with a photon index gamma approximately equals 2.3 confirms a non-thermal emission mechanism. The observed flux in the 3-79 keV band is F(sub X) = (2.0 +/- 0.1) × 10(exp -12)erg cm(-2) s(-1) , corresponding to an unabsorbed X-ray luminosity L(sub X) = (2.6+/-0.8)×10(exp 34) erg s(-1) assuming a distance of 8.0 kpc. Based on theoretical predictions and observations, we conclude that Sgr A-E is unlikely to be a pulsar wind nebula (PWN) or supernova remnant-molecular cloud (SNR-MC) interaction, as previously hypothesized. Instead, the emission could be due to a magnetic flux tube which traps TeV electrons. We propose two possible TeV electron sources: old PWNe (up to (is) approximately 100 kyr) with low surface brightness and radii up to (is) approximately 30 pc or MCs illuminated by cosmic rays (CRs) from CR accelerators such as SNRs or Sgr A*.

  2. Transform fault earthquakes in the North Atlantic - Source mechanisms and depth of faulting

    NASA Technical Reports Server (NTRS)

    Bergman, Eric A.; Solomon, Sean C.

    1988-01-01

    The centroid depths and source mechanisms of 12 large earthquakes on transform faults of the northern Mid-Atlantic Ridge were determined from an inversion of long-period body waveforms. The earthquakes occurred on the Gibbs, Oceanographer, Hayes, Kane, 15 deg 20 min, and Vema transforms. The depth extent of faulting during each earthquake was estimated from the centroid depth and the fault width. The source mechanisms for all events in this study display the strike slip motion expected for transform fault earthquakes; slip vector azimuths agree to 2 to 3 deg of the local strike of the zone of active faulting. The only anomalies in mechanism were for two earthquakes near the western end of the Vema transform which occurred on significantly nonvertical fault planes. Secondary faulting, occurring either precursory to or near the end of the main episode of strike-slip rupture, was observed for 5 of the 12 earthquakes. For three events the secondary faulting was characterized by reverse motion on fault planes striking oblique to the trend of the transform. In all three cases, the site of secondary reverse faulting is near a compression jog in the current trace of the active transform fault zone. No evidence was found to support the conclusions of Engeln, Wiens, and Stein that oceanic transform faults in general are either hotter than expected from current thermal models or weaker than normal oceanic lithosphere.

  3. Transform fault earthquakes in the North Atlantic: Source mechanisms and depth of faulting

    NASA Technical Reports Server (NTRS)

    Bergman, Eric A.; Solomon, Sean C.

    1987-01-01

    The centroid depths and source mechanisms of 12 large earthquakes on transform faults of the northern Mid-Atlantic Ridge were determined from an inversion of long-period body waveforms. The earthquakes occurred on the Gibbs, Oceanographer, Hayes, Kane, 15 deg 20 min, and Vema transforms. The depth extent of faulting during each earthquake was estimated from the centroid depth and the fault width. The source mechanisms for all events in this study display the strike slip motion expected for transform fault earthquakes; slip vector azimuths agree to 2 to 3 deg of the local strike of the zone of active faulting. The only anomalies in mechanism were for two earthquakes near the western end of the Vema transform which occurred on significantly nonvertical fault planes. Secondary faulting, occurring either precursory to or near the end of the main episode of strike-slip rupture, was observed for 5 of the 12 earthquakes. For three events the secondary faulting was characterized by reverse motion on fault planes striking oblique to the trend of the transform. In all three cases, the site of secondary reverse faulting is near a compression jog in the current trace of the active transform fault zone. No evidence was found to support the conclusions of Engeln, Wiens, and Stein that oceanic transform faults in general are either hotter than expected from current thermal models or weaker than normal oceanic lithosphere.

  4. Source mechanisms of microearthquakes at the Southeast Geysers geothermal field, California

    SciTech Connect

    Kirkpatrick, Ann; Peterson, John E., Jr.; Majer, Ernest L.

    1996-01-24

    Source mechanisms of 985 microearthquakes at the Southeast Geysers geothermal field, are investigated using a moment tensor formulation. P- and S-wave amplitude and polarity are utilized to estimate the full, second-order moment tensor, which is then decomposed into isotropic, double-couple, and compensated linear vector dipole components. The moment tensor principal axes are used to infer the directions of principal stress associated with the double-couple component of the source mechanism. Most of the events can be modeled as primarily double-couple; however, a small but significant isotropic component, which can be either positive or negative, is also needed to explain the observed waveforms. Events with positive isotropic components and events with negative isotropic components both occur in areas of steam extraction and in areas of fluid injection. Principal axes of moment tensors with negative isotropic components are aligned with the regional stress field, while those of moment tensors with positive isotropic components differ significantly from the regional stress field. This suggests that two differing inducing mechanisms are required: negative-type events involve local stress perturbations that are small compared to the regional stress, while positive-type events involve stress perturbations which locally dominate over the regional stress.

  5. Similarity assessment of acoustic emission signals and its application in source localization.

    PubMed

    Chen, Shiwan; Yang, Chunhe; Wang, Guibin; Liu, Wei

    2017-03-01

    In conventional AE source localization acoustic emission (AE) signals are applied directly to localize the source without any waveform identification or quality evaluation, which always leads to large errors in source localization. To improve the reliability and accuracy of acoustic emission source localization, an identification procedure is developed to assess the similarity of AE signals to select signals with high quality to localize the AE source. Magnitude square coherence (MSC), wavelet coherence and dynamic timing warping (DTW) are successively applied for similarity assessment. Results show that cluster analysis based on DTW distance is effective to select AE signals with high similarity. Similarity assessment results of the proposed method are almost completely consistent with manual identification. A novel AE source localization procedure is developed combining the selected AE signals with high quality and a direct source localization algorithm. AE data from thermal-cracking tests in Beishan granite are analyzed to demonstrate the effectiveness of the proposed AE localization procedure. AE events are re-localized by the proposed AE localization procedure. And the accuracy of events localization has been improved significantly. The reliability and credibility of AE source localization will be improved by the proposed method.

  6. Sources, factors, mechanisms and possible solutions to pollutants in marine ecosystems.

    PubMed

    Mostofa, Khan M G; Liu, Cong-Qiang; Vione, Davide; Gao, Kunshan; Ogawa, Hiroshi

    2013-11-01

    Algal toxins or red-tide toxins produced during algal blooms are naturally-derived toxic emerging contaminants (ECs) that may kill organisms, including humans, through contaminated fish or seafood. Other ECs produced either naturally or anthropogenically ultimately flow into marine waters. Pharmaceuticals are also an important pollution source, mostly due to overproduction and incorrect disposal. Ship breaking and recycle industries (SBRIs) can also release various pollutants and substantially deteriorate habitats and marine biodiversity. Overfishing is significantly increasing due to the global food crisis, caused by an increasing world population. Organic matter (OM) pollution and global warming (GW) are key factors that exacerbate these challenges (e.g. algal blooms), to which acidification in marine waters should be added as well. Sources, factors, mechanisms and possible remedial measures of these challenges to marine ecosystems are discussed, including their eventual impact on all forms of life including humans.

  7. Analysis of seismic sources for different mechanisms of fracture growth for microseismic monitoring applications

    SciTech Connect

    Duchkov, A. A.; Stefanov, Yu. P.

    2015-10-27

    We have developed and illustrated an approach for geomechanic modeling of elastic wave generation (microsiesmic event occurrence) during incremental fracture growth. We then derived properties of effective point seismic sources (radiation patterns) approximating obtained wavefields. These results establish connection between geomechanic models of hydraulic fracturing and microseismic monitoring. Thus, the results of the moment tensor inversion of microseismic data can be related to different geomechanic scenarios of hydraulic fracture growth. In future, the results can be used for calibrating hydrofrac models. We carried out a series of numerical simulations and made some observations about wave generation during fracture growth. In particular when the growing fracture hits pre-existing crack then it generates much stronger microseismic event compared to fracture growth in homogeneous medium (radiation pattern is very close to the theoretical dipole-type source mechanism)

  8. PDLIM5 links kidney anion exchanger 1 (kAE1) to ILK and is required for membrane targeting of kAE1

    PubMed Central

    Su, Ya; Hiemstra, Thomas F.; Yan, Yahui; Li, Juan; Karet, Hannah I.; Rosen, Lawrence; Moreno, Pablo; Frankl, Fiona E. Karet

    2017-01-01

    Anion exchanger 1 (AE1) mediates Cl−/HCO3− exchange in erythrocytes and kidney intercalated cells where it functions to maintain normal bodily acid-base homeostasis. AE1’s C-terminal tail (AE1C) contains multiple potential membrane targeting/retention determinants, including a predicted PDZ binding motif, which are critical for its normal membrane residency. Here we identify PDLIM5 as a direct binding partner for AE1 in human kidney, via PDLIM5’s PDZ domain and the PDZ binding motif in AE1C. Kidney AE1 (kAE1), PDLIM5 and integrin-linked kinase (ILK) form a multiprotein complex in which PDLIM5 provides a bridge between ILK and AE1C. Depletion of PDLIM5 resulted in significant reduction in kAE1 at the cell membrane, whereas over-expression of kAE1 was accompanied by increased PDLIM5 levels, underscoring the functional importance of PDLIM5 for proper kAE1 membrane residency, as a crucial linker between kAE1 and actin cytoskeleton-associated proteins in polarized cells. PMID:28045035

  9. Quantifying uncertainties in location and source mechanism for Long-Period events at Mt Etna, Italy.

    NASA Astrophysics Data System (ADS)

    Cauchie, Léna; Saccorotti, Gilberto; Bean, Christopher

    2014-05-01

    The manifestation of Long-Period events is documented at many volcanoes worldwide. However the mechanism at their origin is still object of discussion. Models proposed so far involve (i) the resonance of fluid-filled cracks or conduits that are triggered by fluid instabilities or the brittle failure of high viscous magmas and (ii) the slow-rupture earthquakes in the shallow portion of volcanic edifices. Since LP activity usually precedes and accompanies volcanic eruption, the understanding of these sources is important in terms of hazard assessment and eruption early warning. The work is thus primarily aimed at the assessment of the uncertainties in the determination of LP source properties as a consequence of poor knowledge of the velocity structure and location errors. We used data from temporary networks deployed on Mt Etna in 2005. During August, 2005, about 13000 LP events were detected through a STA/LTA approach, and were classified into two families on the basis of waveform similarity. For each family of events, we located the source using three different approaches: (1) a single-station-location method based on the back-propagation of the polarization vector estimated from covariance analysis of three-component signals; (2) multi-channel analysis of data recorded by two seismic arrays; (3) relative locations based on inversion of differential times obtained through cross-correlation of similar waveforms. For all these three different methods, the solutions are very sensitive to the chosen velocity model. We thus iterated the location procedure for different medium properties; the preferred velocity is that for which the results obtained with the three different methods are consistent each other. For each family, we then defined a volume of possible source location and performed a full-waveform, moment tensor (MT) inversion for the entire catalog of events. In this manner, we obtained a MT solution for each grid node of the investigated volume. The MT

  10. Source mechanism of very-long-period signals accompanying dome growth activity at Merapi volcano, Indonesia

    USGS Publications Warehouse

    Hidayat, D.; Chouet, B.; Voight, B.; Dawson, P.; Ratdomopurbo, A.

    2002-01-01

    Very-long-period (VLP) pulses with period of 6-7s, displaying similar waveforms, were identified in 1998 from broadband seismographs around the summit crater. These pulses accompanied most of multiphase (MP) earthquakes, a type of long-period event locally defined at Merapi Volcano. Source mechanisms for several VLP pulses were examined by applying moment tensor inversion to the waveform data. Solutions were consistent with a crack striking ???70?? and dipping ???50?? SW, 100m under the active dome, suggest pressurized gas transport involving accumulation and sudden release of 10-60 m3 of gas in the crack over a 6s interval.

  11. Research on the mechanism of multiple inductively coupled plasma source for large area processing

    NASA Astrophysics Data System (ADS)

    Lee, Jangjae; Kim, Sijun; Kim, Daewoong; Kim, Kwangki; Lee, Youngseok; You, Shinjae

    2016-09-01

    In the plasma processing, inductively coupled plasma having the high-density is often used for high productivity. In large area plasma processing, the plasma can be generated by using the multi-pole connected in parallel. However, in case of this, it is difficult for power to be transferred to plasma uniformly. To solve the problem, we studied the mechanism of inductively coupled plasma connected in parallel. By using the transformer model, the multiple ICP source is treated. We also studied about the change of the plasma parameters over the time through the power balance equation and particle balance equation. Corresponding author.

  12. Loss of the AE3 Cl−/HCO−3 exchanger in mice affects rate-dependent inotropy and stress-related AKT signaling in heart

    PubMed Central

    Prasad, Vikram; Lorenz, John N.; Lasko, Valerie M.; Nieman, Michelle L.; Al Moamen, Nabeel J.; Shull, Gary E.

    2013-01-01

    Cl−/HCO−3 exchangers are expressed abundantly in cardiac muscle, suggesting that HCO−3 extrusion serves an important function in heart. Mice lacking Anion Exchanger Isoform 3 (AE3), a major cardiac Cl−/HCO−3 exchanger, appear healthy, but loss of AE3 causes decompensation in a hypertrophic cardiomyopathy (HCM) model. Using intra-ventricular pressure analysis, in vivo pacing, and molecular studies we identified physiological and biochemical changes caused by loss of AE3 that may contribute to decompensation in HCM. AE3-null mice had normal cardiac contractility under basal conditions and after β-adrenergic stimulation, but pacing of hearts revealed that frequency-dependent inotropy was blunted, suggesting that AE3-mediated HCO−3 extrusion is required for a robust force-frequency response (FFR) during acute biomechanical stress in vivo. Modest changes in expression of proteins that affect Ca2+-handling were observed, but Ca2+-transient analysis of AE3-null myocytes showed normal twitch-amplitude and Ca2+-clearance. Phosphorylation and expression of several proteins implicated in HCM and FFR, including phospholamban (PLN), myosin binding protein C, and troponin I were not altered in hearts of paced AE3-null mice; however, phosphorylation of Akt, which plays a central role in mechanosensory signaling, was significantly higher in paced AE3-null hearts than in wild-type controls and phosphorylation of AMPK, which is affected by Akt and is involved in energy metabolism and some cases of HCM, was reduced. These data show loss of AE3 leads to impaired rate-dependent inotropy, appears to affect mechanical stress-responsive signaling, and reduces activation of AMPK, which may contribute to decompensation in heart failure. PMID:24427143

  13. Evidence of a halo formation mechanism in the Spallation Neutron Source linac

    NASA Astrophysics Data System (ADS)

    Jeon, Dong-O.

    2013-04-01

    A new halo formation mechanism and its mitigation scheme [D. Jeon, J. Stovall, A. Aleksandrov, J. Wei, J. Staples, R. Keller, L. Young, H. Takeda, and S. Nath, Phys. Rev. ST Accel. Beams 5, 094201 (2002)PRABFM1098-440210.1103/PhysRevSTAB.5.094201] are verified experimentally through a series of emittance measurements performed during the drift tube linac tank 1 commissioning of the Spallation Neutron Source. This is a rare experiment evidence of a halo formation mechanism. As the simulation predicts, the emittance measurements clearly show a visible halo reduction as well as a significant rms emittance reduction when the proposed round beam optics is employed. The emittance measurement results are consistent with multiparticle simulations and also consistent with wire scanner results. These measurements serve as a valuable code benchmarking for a beam under an intense space charge effect.

  14. Estimation of The Radiation Environment Based On The NASA Ap-8 and Ae-8 Models

    NASA Technical Reports Server (NTRS)

    Morton, Thomas; Lyons, Valerie (Technical Monitor)

    2002-01-01

    In this paper, we discuss the earth's trapped radiation environment, as described by the NASA models AP-8 and AE-8. We include a description of the sources and structure of the trapped radiation belts, and their dependence on external factors. After describing how to use the models to predict the environment, we present data from various space missions, and compare those data to the models. This shows the limits and strengths of the models. Finally, we describe alternative models of the trapped radiation belts, and discuss why they have not been widely adopted yet.

  15. Inefficient Chronic Activation of Parietal Cells in Ae2a,b−/− Mice

    PubMed Central

    Recalde, Sergio; Muruzábal, Francisco; Looije, Norbert; Kunne, Cindy; Burrell, María A.; Sáez, Elena; Martínez-Ansó, Eduardo; Salas, January T.; Mardones, Pablo; Prieto, Jesús; Medina, Juan F.; Elferink, Ronald P.J. Oude

    2006-01-01

    In parietal cells, basolateral Ae2 Cl−/HCO3− exchanger (Slc4a2) appears to compensate for luminal H+ pumping while providing Cl− for apical secretion. In mouse and rat, mRNA variants Ae2a, Ae2b1, Ae2b2, and Ae2c2 are all found in most tissues (although the latter at very low levels), whereas Ae2c1 is restricted to the stomach. We studied the acid secretory function of gastric mucosa in mice with targeted disruption of Ae2a, Ae2b1, and Ae2b2 (but not Ae2c) isoforms. In the oxyntic mucosa of Ae2a,b−/− mice, total Ae2 protein was nearly undetectable, indicating low gastric expression of the Ae2c isoforms. In Ae2a,b−/− mice basal acid secretion was normal, whereas carbachol/histamine-stimulated acid secretion was impaired by 70%. These animals showed increased serum gastrin levels and hyperplasia of G cells. Immunohistochemistry and electron microscopy revealed baseline activation of parietal cells with fusion of intracellular H+/K+-ATPase-containing vesicles with the apical membrane and degenerative changes (but not substantial apoptosis) in a subpopulation of these cells. Increased expression of proliferating cell nuclear antigen in the oxyntic glands suggested enhanced Ae2a,b−/− parietal cell turnover. These data reveal a critical role of Ae2a-Ae2b1-Ae2b2 isoforms in stimulated gastric acid secretion whereas residual Ae2c isoforms could account to a limited extent for basal acid secretion. PMID:16816370

  16. Location and source mechanism of the Karlsruhe earthquake of 24 September 2014

    NASA Astrophysics Data System (ADS)

    Barth, Andreas

    2016-07-01

    On 24 September 2014, a ML 2.3 earthquake occurred southwest of the urban area of Karlsruhe, Germany, which was felt by a few people (maximum intensity I 0 = III). It was the first seismic event in this highly populated area since an I 0 = VII earthquake in 1948. Data of 35 permanent and temporary seismometers were analysed to localise the event and to determine the focal mechanism to compare it to previous seismicity. Restricting the data to P- and S-phases from 18 nearby stations and optimising the local earth model result in an epicentre in the southwest of the city at 48.986°N/8.302°E and in a hypocentral depth of 10 km. To calculate the focal mechanism, 22 P- and 5 SH-polarities were determined that constrain a stable left lateral strike-slip focal mechanism with a minor thrusting component and nodal planes striking NE-SW and NW-SE. The epicentre lies in the vicinity of the I 0 = VII earthquake of 1948. Both events are part of the graben-parallel flower structure beneath the Upper Rhine Graben, parallel to the active Rastatt source zone, which runs 5 km further east and included the epicentre of the 1933 Rastatt I 0 = VII earthquake. The focal mechanisms of the 2014 and 1948 earthquakes show NE-SW striking nodal planes that dip to the southeast. However, for the 1948 event, a normal faulting mechanism was determined earlier. Taking the uncertainty of the epicentre and focal mechanism in 1948 and its fault dimensions into account, both events might have happened on the same fault plane.

  17. Chloride Accumulators NKCC1 and AE2 in Mouse GnRH Neurons: Implications for GABAA Mediated Excitation

    PubMed Central

    Taylor-Burds, Carol; Cheng, Paul; Wray, Susan

    2015-01-01

    A developmental “switch” in chloride transporters occurs in most neurons resulting in GABAA mediated hyperpolarization in the adult. However, several neuronal cell subtypes maintain primarily depolarizing responses to GABAA receptor activation. Among this group are gonadotropin-releasing hormone-1 (GnRH) neurons, which control puberty and reproduction. NKCC1 is the primary chloride accumulator in neurons, expressed at high levels early in development and contributes to depolarization after GABAA receptor activation. In contrast, KCC2 is the primary chloride extruder in neurons, expressed at high levels in the adult and contributes to hyperpolarization after GABAA receptor activation. Anion exchangers (AEs) are also potential modulators of responses to GABAA activation since they accumulate chloride and extrude bicarbonate. To evaluate the mechanism(s) underlying GABAA mediated depolarization, GnRH neurons were analyzed for 1) expression of chloride transporters and AEs in embryonic, pre-pubertal, and adult mice 2) responses to GABAA receptor activation in NKCC1-/- mice and 3) function of AEs in these responses. At all ages, GnRH neurons were immunopositive for NKCC1 and AE2 but not KCC2 or AE3. Using explants, calcium imaging and gramicidin perforated patch clamp techniques we found that GnRH neurons from NKCC1-/- mice retained relatively normal responses to the GABAA agonist muscimol. However, acute pharmacological inhibition of NKCC1 with bumetanide eliminated the depolarization/calcium response to muscimol in 40% of GnRH neurons from WT mice. In the remaining GnRH neurons, HCO3- mediated mechanisms accounted for the remaining calcium responses to muscimol. Collectively these data reveal mechanisms responsible for maintaining depolarizing GABAA mediated transmission in GnRH neurons. PMID:26110920

  18. 19 CFR 192.11 - Description of the AES.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 2 2011-04-01 2011-04-01 false Description of the AES. 192.11 Section 192.11 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE... 30 of the Census Regulations (15 CFR part 30, subpart E), denominated Electronic Filing...

  19. The phenotype Ae1B: a probable result of chimerism.

    PubMed Central

    Longster, G H; Robinson, E A; North, D I

    1978-01-01

    An apparently normal healthy adult with the blood group phenotype Ae1B is described. The unusual ABO group is apparently the result of chimerism, the proportion of the minor population of cells being so small as to be only detectable by absorption and elution techniques. PMID:739532

  20. 15 CFR 758.2 - Automated Export System (AES).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... CLEARANCE REQUIREMENTS § 758.2 Automated Export System (AES). The Census Bureau's Foreign Trade Statistics... Administration Regulations (EAR) and Foreign Trade Statistics Regulations (FTSR). These procedures and safeguards... § 750.8(b) of the EAR, if requested; (v) Compliance with the destination control statement provisions...

  1. 15 CFR 758.2 - Automated Export System (AES).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 15 Commerce and Foreign Trade 2 2012-01-01 2012-01-01 false Automated Export System (AES). 758.2 Section 758.2 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE EXPORT ADMINISTRATION REGULATIONS...

  2. 15 CFR 758.2 - Automated Export System (AES).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 2 2010-01-01 2010-01-01 false Automated Export System (AES). 758.2 Section 758.2 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE EXPORT ADMINISTRATION REGULATIONS...

  3. Gravity waves in the thermosphere observed by the AE satellites

    NASA Technical Reports Server (NTRS)

    Gross, S. H.; Reber, C. A.; Huang, F. T.

    1983-01-01

    Atmospheric Explorer (AE) satellite data were used to investigate the spectra characteristics of wave-like structure observed in the neutral and ionized components of the thermosphere. Power spectral analysis derived by the maximum entropy method indicate the existence of a broad spectrum of scale sizes for the fluctuations ranging from tens to thousands of kilometers.

  4. 19 CFR 192.11 - Description of the AES.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) EXPORT CONTROL Filing of Export Information Through the Automated Export System (AES... commodity export information (see, 15 CFR 30.16) to submit such information electronically, rather than...

  5. An AES study of surface oxidation of zirconium

    NASA Astrophysics Data System (ADS)

    Tomita, M.; Tanabe, T.; Imoto, S.

    1989-02-01

    A clean Zr surface, prepared by several cycles of heating and Ar ion sputtering, is exposed to oxygen gas under 10 -5-10 -6 Pa at room temperature (RT), and surface oxidation behavior is examined by in-situ AES measurements. Subsequent depth profiling of the oxidized sample is carried out and the oxygen diffusion coefficient in α-Zr is evaluated. All AES peaks of Zr and O are modified with increasing oxygen exposure. The changes of the AES peaks show three stages of oxidation which are attributed to (1) oxygen solution in α-Zr, (2) nucleation and growth of ZrO 2 on the surface and (3) growth of the ZrO 2 layer. Above 9000 L, the surface is completely covered with ZrO 2 and the present AES study shows no evidence of the appearance of suboxide suggested by Sen et al. and de Gonzalez et al. The depth profiling of the oxidized sample indicates coexistence of ZrO 2 and α-Zr(O) with an oxygen content of around 30 at% over a depth of several nm without any clear-cut boundary of ZrO 2 and α-Zr(O). The apparent oxygen diffusion coefficient at RT estimated using a simple model, 10 -21 m 2 s -1, is much larger than the extrapolated value, around 10 -40 m 2 s -1, from the literature at high temperatures.

  6. The noncompetitive inhibitor WW781 senses changes in erythrocyte anion exchanger (AE1) transport site conformation and substrate binding.

    PubMed

    Knauf, P A; Raha, N M; Spinelli, L J

    2000-02-01

    WW781 binds reversibly to red blood cell AE1 and inhibits anion exchange by a two-step mechanism, in which an initial complex (complex 1) is rapidly formed, and then there is a slower equilibration to form a second complex (complex 2) with a lower free energy. According to the ping-pong kinetic model, AE1 can exist in forms with the anion transport site facing either inward or outward, and the transition between these forms is greatly facilitated by binding of a transportable substrate such as Cl(-). Both the rapid initial binding of WW781 and the formation of complex 2 are strongly affected by the conformation of AE1, such that the forms with the transport site facing outward have higher affinity than those with the transport site facing inward. In addition, binding of Cl(-) seems to raise the free energy of complex 2 relative to complex 1, thereby reducing the equilibrium binding affinity, but Cl(-) does not compete directly with WW781. The WW781 binding site, therefore, reveals a part of the AE1 structure that is sensitive to Cl(-) binding and to transport site orientation, in addition to the disulfonic stilbene binding site. The relationship of the inhibitory potency of WW781 under different conditions to the affinities for the different forms of AE1 provides information on the possible asymmetric distributions of unloaded and Cl(-)-loaded transport sites that are consistent with the ping-pong model, and supports the conclusion from flux and nuclear magnetic resonance data that both the unloaded and Cl(-)-loaded sites are very asymmetrically distributed, with far more sites facing the cytoplasm than the outside medium. This asymmetry, together with the ability of WW781 to recruit toward the forms with outward-facing sites, implies that WW781 may be useful for changing the conformation of AE1 in studies of structure-function relationships.

  7. A case of bleomycin-induced acral erythema (AE) with eccrine squamous syringometaplasia (ESS) and summary of reports of AE with ESS in the literature.

    PubMed

    Tsuboi, Hiromi; Yonemoto, Kohzoh; Katsuoka, Kensei

    2005-11-01

    Chemotherapy-induced acral erythema (AE) is primarily induced by hydroxyurea, methotrexate, and cytarabine, although there are rare reports of AE induced by combination chemotherapy containing bleomycin. It is thought that the accumulation of chemotherapeutic drugs in eccrine glands may cause eccrine squamous syringometaplasia (ESS), which is characterized by metaplasia and focal necrosis of the epithelium of the eccrine duct. ESS is occasionally detected in conjunction with AE, but such occurrences are relatively uncommon. This is the first report of AE with ESS induced by the administration of bleomycin alone. We also provide a summary of past cases of AE with ESS in the literature.

  8. Earthquake source mechanisms and transform fault tectonics in the Gulf of California

    NASA Technical Reports Server (NTRS)

    Goff, John A.; Bergman, Eric A.; Solomon, Sean C.

    1987-01-01

    The source parameters of 19 large earthquakes in the Gulf of California were determined from inversions of long-period P and SH waveforms. The goal was to understand the recent slip history of this dominantly transform boundary between the Pacific and North American plates as well as the effect on earthquake characteristics of the transition from young oceanic to continental lithosphere. For the better recorded transform events, the fault strike is resolved to + or - 4 deg at 90 percent confidence. The slip vectors thus provide important constraints on the direction of relative plate motion. Most centroid depths are poorly resolved because of tradeoffs between depth and source time function. On the basis of waveform modeling, historical seismicity, and other factors, it is appropriate to divide the Gulf into three distinct zones. The difference in seismic character among the three zones is likely the result of differing levels of maturity of the processes of rifting, generation of oceanic crust, and formation of stable oceanic transform faults. The mechanism of an earthquake on the Tres Marias Escarpment is characterized by thrust faulting and likely indicates the direction of relative motion between the Rivera and North American plates. This mechanism requires revision in plate velocity models which predict strike slip motion at this location.

  9. Source Mechanisms of Destructive Tsunamigenic Earthquakes occurred along the Major Subduction Zones

    NASA Astrophysics Data System (ADS)

    Yolsal-Çevikbilen, Seda; Taymaz, Tuncay; Ulutaş, Ergin

    2016-04-01

    Subduction zones, where an oceanic plate is subducted down into the mantle by tectonic forces, are potential tsunami locations. Many big, destructive and tsunamigenic earthquakes (Mw > 7.5) and high amplitude tsunami waves are observed along the major subduction zones particularly near Indonesia, Japan, Kuril and Aleutan Islands, Gulf of Alaska, Southern America. Not all earthquakes are tsunamigenic; in order to generate a tsunami, the earthquake must occur under or near the ocean, be large, and create significant vertical movements of the seafloor. It is also known that tsunamigenic earthquakes release their energy over a couple of minutes, have long source time functions and slow-smooth ruptures. In this study, we performed point-source inversions by using teleseismic long-period P- and SH- and broad-band P-waveforms recorded by the Federation of Digital Seismograph Networks (FDSN) and the Global Digital Seismograph Network (GDSN) stations. We obtained source mechanism parameters and finite-fault slip distributions of recent destructive ten earthquakes (Mw ≥ 7.5) by comparing the shapes and amplitudes of long period P- and SH-waveforms, recorded in the distance range of 30° - 90°, with synthetic waveforms. We further obtained finite-fault rupture histories of those earthquakes to determine the faulting area (fault length and width), maximum displacement, rupture duration and stress drop. We applied a new back-projection method that uses teleseismic P-waveforms to integrate the direct P-phase with reflected phases from structural discontinuities near the source, and customized it to estimate the spatio-temporal distribution of the seismic energy release of earthquakes. Inversion results exhibit that recent tsunamigenic earthquakes show dominantly thrust faulting mechanisms with small amount of strike-slip components. Their focal depths are also relatively shallow (h < 40 km). As an example, the September 16, 2015 Illapel (Chile) earthquake (Mw: 8.3; h: 26 km

  10. Seismic Source Mechanism of Gas-Piston Activity at Kilauea Inferred from Inversion of Broadband Waveforms

    NASA Astrophysics Data System (ADS)

    Chouet, B. A.; Dawson, P. B.

    2015-12-01

    Among the broad range of magmatic processes observed in the Overlook pit crater in Kilauea Caldera are recurring episodes of gas-piston activity. This activity is accompanied by repetitive seismic signals recorded by a broadband network deployed in the summit caldera. We use the seismic data to model the source mechanism of representative gas-piston events in a sequence that occurred on 20-25 August 2011 during a gentle inflation of the Kilauea summit. We apply a new waveform inversion method that accounts for the contributions from both translation and tilt in horizontal seismograms through the use of Green's functions representing the seismometer response to translation and tilt ground motions. This method enables a robust description of the source mechanism over the period range of 1 - 10,000 s. Most of the seismic wave field produced by gas-pistoning originates in a source region ~1 km below the eastern perimeter of Halema'uma'u pit crater. The observed waveforms are well explained by a simple volumetric source with geometry composed of two intersecting cracks featuring an east-striking crack (dike) dipping 80° to the north, intersecting a north-striking crack (inclined sheet) dipping 65° to the east. Each gas-piston event is characterized by a rapid inflation lasting a few minutes trailed by a slower deflation ramp extending up to 15 minutes, attributed to the efficient coupling at the source centroid location of the pressure and momentum changes accompanying the growth and collapse of a layer of foam at the top of the magma column. Assuming a simple lumped parameter representation of the shallow magmatic system, the observed pressure and volume variations can be modeled with the following attributes: foam thickness (10 - 50 m), foam cell diameter (0.04 - 0.10 m), and gas-injection velocity (0.01 - 0.06 m s-1). Based on the change in the period of very-long-period oscillations accompanying the onset of the gas-piston signal and tilt evidence, the height of

  11. Earthquake Source Mechanisms, Coseismic Costal Uplifts and Tsunamigenesis in the Eastern Hellenic Arc and Trench

    NASA Astrophysics Data System (ADS)

    Triantafyllou, Ioanna; Papadopoulos, Gerassimos

    2015-04-01

    The eastern segment of the Hellenic Arc and Trench (HA-T) is tectonically characterized by interplate seismic activity with mainly thrust mechanism. Large earthquakes and tsunamis are known from both the historical and geological record particularly in Rhodes Isl. (Greece). Geological observations have indicated that eastern Rhodes has systematically uplifted during the Holocene with uplift amplitude increasing from S to N with average velocity ranging from 0 at south to 1 mm/yr at the NE side of the island. In order to better understand why some large earthquakes caused tsunamis while others did not, we examined the source mechanisms and the submarine setting of historical and instrumental earthquakes occurring in the area of Rhodes. Historical sources maintain direct evidence that three, large earthquakes caused coseismic uplift with permanent sea retreat in the city of Rhodes at the NE side of the island at 227 BC, AD 142 and 12 October 1856. The average historical coseismic uplift was found around 0.7 mm/yr which is close to the geological average. We examined original documentary sources and found that these earthquakes were non-tsunamigenic, thus revising previous thoughts. We suggested that the ones of 227 BC and AD 142, both with magnitude M~7, were crustal earthquakes having their epicenters offshore but close to Rhodes city, that is in shallow water domain. The 1856 earthquake of M~7.5 very likely was of intermediate focal depth, quite similar to that of 26 June 1926, therefore it was not capable to produce a tsunami. Another set of earthquakes includes the large events of AD 1303, 1481, 1609 and 1741. It is documented from historical sources and/or geological observations that all of them caused powerful tsunamis. However, no evidence for coseismic uplift was found in Rhodes Isl. Therefore, we suggested that these earthquakes had their epicenters offshore away from the island. The 1303 earthquake was a very large event (M~8) that ruptured under deep

  12. Supraphysiologic levels of the AML1-ETO isoform AE9a are essential for transformation

    PubMed Central

    Link, Kevin A.; Lin, Shan; Shrestha, Mahesh; Bowman, Melissa; Wunderlich, Mark; Bloomfield, Clara D.; Huang, Gang; Mulloy, James C.

    2016-01-01

    Chromosomal translocation 8;21 is found in 40% of the FAB M2 subtype of acute myeloid leukemia (AML). The resultant in-frame fusion protein AML1-ETO (AE) acts as an initiating oncogene for leukemia development. AE immortalizes human CD34+ cord blood cells in long-term culture. We assessed the transforming properties of the alternatively spliced AE isoform AE9a (or alternative splicing at exon 9), which is fully transforming in a murine retroviral model, in human cord blood cells. Full activity was realized only upon increased fusion protein expression. This effect was recapitulated in the AE9a murine AML model. Cotransduction of AE and AE9a resulted in a strong selective pressure for AE-expressing cells. In the context of AE, AE9a did not show selection for increased expression, affirming observations of human t(8;21) patient samples where full-length AE is the dominant protein detected. Mechanistically, AE9a showed defective transcriptional regulation of AE target genes that was partially corrected at high expression. Together, these results bring an additional perspective to our understanding of AE function and highlight the contribution of oncogene expression level in t(8;21) experimental models. PMID:27457952

  13. REDBACK: an Open-Source Highly Scalable Simulation Tool for Rock Mechanics with Dissipative Feedbacks

    NASA Astrophysics Data System (ADS)

    Poulet, T.; Veveakis, M.; Paesold, M.; Regenauer-Lieb, K.

    2014-12-01

    Multiphysics modelling has become an indispensable tool for geoscientists to simulate the complex behaviours observed in their various fields of study where multiple processes are involved, including thermal, hydraulic, mechanical and chemical (THMC) laws. This modelling activity involves simulations that are computationally expensive and its soaring uptake is tightly linked to the increasing availability of supercomputing power and easy access to powerful nonlinear solvers such as PETSc (http://www.mcs.anl.gov/petsc/). The Multiphysics Object-Oriented Simulation Environment (MOOSE) is a finite-element, multiphysics framework (http://mooseframework.org) that can harness such computational power and allow scientists to develop easily some tightly-coupled fully implicit multiphysics simulations that run automatically in parallel on large clusters. This open-source framework provides a powerful tool to collaborate on numerical modelling activities and we are contributing to its development with REDBACK (https://github.com/pou036/redback), a module for Rock mEchanics with Dissipative feedBACKs. REDBACK builds on the tensor mechanics finite strain implementation available in MOOSE to provide a THMC simulator where the energetic formulation highlights the importance of all dissipative terms in the coupled system of equations. We show first applications of fully coupled dehydration reactions triggering episodic fluid transfer through shear zones (Alevizos et al, 2014). The dimensionless approach used allows focusing on the critical underlying variables which are driving the resulting behaviours observed and this tool is specifically designed to study material instabilities underpinning geological features like faulting, folding, boudinage, shearing, fracturing, etc. REDBACK provides a collaborative and educational tool which captures the physical and mathematical understanding of such material instabilities and provides an easy way to apply this knowledge to realistic

  14. Waste Separation Press (WSP): a mechanical pretreatment option for organic waste from source separation.

    PubMed

    Jank, Anna; Müller, Wolfgang; Schneider, Irene; Gerke, Frederic; Bockreis, Anke

    2015-05-01

    An efficient biological treatment of source separated organic waste from household kitchens and gardens (biowaste) requires an adequate upfront mechanical preparation which possibly includes a hand sorting for the separation of contaminants. In this work untreated biowaste from households and gardens and the screen overflow >60mm of the same waste were mechanically treated by a Waste Separation Press (WSP). The WSP separates the waste into a wet fraction for biological treatment and a fraction of dry contaminants for incineration. The results show that it is possible to replace a hand sorting of contaminants, the milling and a screening of organic waste before the biological treatment by using the WSP. A special focus was put on the contaminants separation. The separation of plastic film from the untreated biowaste was 67% and the separation rate of glass was about 92%. About 90% of the organics were transferred to the fraction for further biological treatment. When treating the screen overflow >60mm with the WSP 86% of the plastic film and 88% of the glass were transferred to the contaminants fraction. 32% of the organic was transferred to the contaminants fraction and thereby lost for a further biological treatment. Additionally it was calculated that national standards for glass contaminants in compost can be met when using the WSP to mechanically treat the total biowaste. The loss of biogas by transferring biodegradable organics to the contaminants fraction was about 11% when preparing the untreated biowaste with the WSP.

  15. AE-941, a multifunctional antiangiogenic compound: trials in renal cell carcinoma.

    PubMed

    Bukowski, Ronald M

    2003-08-01

    The therapy of renal cell carcinoma remains a challenge for medical oncologists and urologists. During the past 10 years, the molecular abnormalities occurring in various subtypes of renal cancer, such as clear cell renal carcinoma, have been well described. The genetic abnormalities found in clear cell tumours involve chromosome 3p and, additionally, hypermethylation of the von Hippel-Lindau (VHL) gene can be detected. The VHL protein is involved in the angiogenic cascade in non-hypoxic conditions, and the possible role of mutant or hypermethylated VHL protein in promoting angiogenesis is, therefore, of interest. The majority of patients with renal cell carcinoma who receive treatment, such as IL-2 and/or IFN, fail and develop progressive disease. Therapy is therefore inadequate and novel approaches, such as those inhibiting angiogenesis, are of interest. The agent AE-941 (Neovostat trade mark; AEterna) was developed based on the observation that shark cartilage may contain biologically active inhibitors of angiogenesis. A variety of in vitro and in vivo activities of this preparation have been identified. At the molecular level, AE-941 appears to exhibit four different potential mechanisms of action: modulation of matrix proteases; inhibition of vascular endothelial growth factor binding to its receptor; induction of endothelial cell apoptosis; and stimulation of angiostatin production. The antitumour effects of AE-941 are seen in multiple murine models and involve not only effects on primary tumour growth but also on development of metastases. AE-941 is administered orally and has an excellent toxicity profile. Of interest are the findings in patients with renal cell carcinoma. Preliminary trials in this setting have suggested that responses to AE-941 occur and that patients receiving higher doses of this agent may have improved survival. Based on these preliminary data, a large, multi-institutional, randomised, Phase III trial of this agent has now been

  16. Groundwater source contamination mechanisms: Physicochemical profile clustering, risk factor analysis and multivariate modelling

    NASA Astrophysics Data System (ADS)

    Hynds, Paul; Misstear, Bruce D.; Gill, Laurence W.; Murphy, Heather M.

    2014-04-01

    An integrated domestic well sampling and "susceptibility assessment" programme was undertaken in the Republic of Ireland from April 2008 to November 2010. Overall, 211 domestic wells were sampled, assessed and collated with local climate data. Based upon groundwater physicochemical profile, three clusters have been identified and characterised by source type (borehole or hand-dug well) and local geological setting. Statistical analysis indicates that cluster membership is significantly associated with the prevalence of bacteria (p = 0.001), with mean Escherichia coli presence within clusters ranging from 15.4% (Cluster-1) to 47.6% (Cluster-3). Bivariate risk factor analysis shows that on-site septic tank presence was the only risk factor significantly associated (p < 0.05) with bacterial presence within all clusters. Point agriculture adjacency was significantly associated with both borehole-related clusters. Well design criteria were associated with hand-dug wells and boreholes in areas characterised by high permeability subsoils, while local geological setting was significant for hand-dug wells and boreholes in areas dominated by low/moderate permeability subsoils. Multivariate susceptibility models were developed for all clusters, with predictive accuracies of 84% (Cluster-1) to 91% (Cluster-2) achieved. Septic tank setback was a common variable within all multivariate models, while agricultural sources were also significant, albeit to a lesser degree. Furthermore, well liner clearance was a significant factor in all models, indicating that direct surface ingress is a significant well contamination mechanism. Identification and elucidation of cluster-specific contamination mechanisms may be used to develop improved overall risk management and wellhead protection strategies, while also informing future remediation and maintenance efforts.

  17. Groundwater source contamination mechanisms: physicochemical profile clustering, risk factor analysis and multivariate modelling.

    PubMed

    Hynds, Paul; Misstear, Bruce D; Gill, Laurence W; Murphy, Heather M

    2014-04-01

    An integrated domestic well sampling and "susceptibility assessment" programme was undertaken in the Republic of Ireland from April 2008 to November 2010. Overall, 211 domestic wells were sampled, assessed and collated with local climate data. Based upon groundwater physicochemical profile, three clusters have been identified and characterised by source type (borehole or hand-dug well) and local geological setting. Statistical analysis indicates that cluster membership is significantly associated with the prevalence of bacteria (p=0.001), with mean Escherichia coli presence within clusters ranging from 15.4% (Cluster-1) to 47.6% (Cluster-3). Bivariate risk factor analysis shows that on-site septic tank presence was the only risk factor significantly associated (p<0.05) with bacterial presence within all clusters. Point agriculture adjacency was significantly associated with both borehole-related clusters. Well design criteria were associated with hand-dug wells and boreholes in areas characterised by high permeability subsoils, while local geological setting was significant for hand-dug wells and boreholes in areas dominated by low/moderate permeability subsoils. Multivariate susceptibility models were developed for all clusters, with predictive accuracies of 84% (Cluster-1) to 91% (Cluster-2) achieved. Septic tank setback was a common variable within all multivariate models, while agricultural sources were also significant, albeit to a lesser degree. Furthermore, well liner clearance was a significant factor in all models, indicating that direct surface ingress is a significant well contamination mechanism. Identification and elucidation of cluster-specific contamination mechanisms may be used to develop improved overall risk management and wellhead protection strategies, while also informing future remediation and maintenance efforts.

  18. MALDI In-Source Decay of Protein: The Mechanism of c-Ion Formation

    PubMed Central

    Takayama, Mitsuo

    2016-01-01

    The in-source decay (ISD) phenomenon, the fragmentation at an N–Cα bond of a peptide backbone that occurs within several tens of nanoseconds in the ion-source in matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS), is discussed from the standpoints of the discovery and early publications dealing with MALDI-ISD, the formation of c-ions in energy-sudden desorption/ionization methods, the formation of radical species in a MALDI, model construction for ISD, and matrix materials that are suitable for use in MALDI-ISD. The formation of c-ions derived from peptides and proteins in MALDI-ISD can be rationalized by a mechanism involving intermolecular hydrogen transfer, denoted as the “Takayama’s model” by De Pauw’s group (Anal. Chem. 79: 8678–8685, 2007). It should be emphasized that the model for MALDI-ISD was constructed on the basis of X-ray crystallography and scanning probe microscopy (SPM) analyses of matrix crystals, as well as the use of isotopically-labelled peptides. PMID:27162707

  19. CORONAL SOURCES, ELEMENTAL FRACTIONATION, AND RELEASE MECHANISMS OF HEAVY ION DROPOUTS IN THE SOLAR WIND

    SciTech Connect

    Weberg, Micah J.; Lepri, Susan T.; Zurbuchen, Thomas H. E-mail: slepri@umich.edu

    2015-03-10

    The elemental abundances of heavy ions (masses larger than He) in the solar wind provide information about physical processes occurring in the corona. Additionally, the charge state distributions of these heavy ions are sensitive to the temperature profiles of their respective source regions in the corona. Heavy ion dropouts are a relatively new class of solar wind events identified by both elemental and ionic charge state distributions. We have shown that their origins lie in large, closed coronal loops where processes such as gravitational settling dominate and can cause a mass-dependent fractionation pattern. In this study we consider and attempt to answer three fundamental questions concerning heavy ion dropouts: (1) 'where are the source loops located in the large-scale corona?'; (2) 'how does the interplay between coronal processes influence the end elemental abundances?'; and (3) 'what are the most probable release mechanisms'? We begin by analyzing the temporal and spatial variability of heavy ion dropouts and their correlation with heliospheric plasma and magnetic structures. Next we investigate the ordering of the elements inside dropouts with respect to mass, ionic charge state, and first ionization potential. Finally, we discuss these results in the context of the prevailing solar wind theories and the processes they posit that may be responsible for the release of coronal plasma into interplanetary space.

  20. An open source GIS-based tool to integrate the fragmentation mechanism in rockfall propagation

    NASA Astrophysics Data System (ADS)

    Matas, Gerard; Lantada, Nieves; Gili, Josep A.; Corominas, Jordi

    2015-04-01

    Rockfalls are frequent instability processes in road cuts, open pit mines and quarries, steep slopes and cliffs. Even though the stability of rock slopes can be determined using analytical approaches, the assessment of large rock cliffs require simplifying assumptions due to the difficulty of working with a large amount of joints, the scattering of both the orientations and strength parameters. The attitude and persistency of joints within the rock mass define the size of kinematically unstable rock volumes. Furthermore the rock block will eventually split in several fragments during its propagation downhill due its impact with the ground surface. Knowledge of the size, energy, trajectory… of each block resulting from fragmentation is critical in determining the vulnerability of buildings and protection structures. The objective of this contribution is to present a simple and open source tool to simulate the fragmentation mechanism in rockfall propagation models and in the calculation of impact energies. This tool includes common modes of motion for falling boulders based on the previous literature. The final tool is being implemented in a GIS (Geographic Information Systems) using open source Python programming. The tool under development will be simple, modular, compatible with any GIS environment, open source, able to model rockfalls phenomena correctly. It could be used in any area susceptible to rockfalls with a previous adjustment of the parameters. After the adjustment of the model parameters to a given area, a simulation could be performed to obtain maps of kinetic energy, frequency, stopping density and passing heights. This GIS-based tool and the analysis of the fragmentation laws using data collected from recent rockfall have being developed within the RockRisk Project (2014-2016). This project is funded by the Spanish Ministerio de Economía y Competitividad and entitled "Rockfalls in cliffs: risk quantification and its prevention"(BIA2013-42582-P).

  1. Sources and mechanisms of nitrate and orthophosphate transport in urban stormwater runoff from residential catchments.

    PubMed

    Yang, Yun-Ya; Toor, Gurpal S

    2017-04-01

    Nutrients export from residential catchments contributes to water quality impairment in urban water bodies. We investigated the concentrations, transport mechanisms, and sources of nitrate-nitrogen (NO3-N) and orthophosphate-phosphorus (PO4-P) in urban stormwater runoff generated in residential catchments in Tampa Bay, Florida, United States. Street runoff samples, collected over 21 storm events, were supplemented with rainfall and roof runoff samples from six representative residential catchments. Samples were analyzed for N and P forms, N and oxygen (O) isotopes of nitrate (δ(18)O-NO3(-) and δ(15)N-NO3(-)), and δ(18)O and hydrogen (δD) isotopes of water (H2O). We found that the main NO3-N source in street runoff was atmospheric deposition (range: 35-64%), followed by chemical N fertilizers (range: 1-39%), and soil and organic N (range: 7-33%), whereas PO4-P in the street runoff likely originated from erosion of soil particles and mineralization from organic materials (leaves, grass clippings). The variability in the sources and concentrations of NO3-N and PO4-P across catchments is attributed to different development designs and patterns, use of various fill materials during land development, and landscaping practices. This data can be useful to develop strategies to offset the impacts of urban development (e.g., designs and patterns resulting in variable impervious areas) and management (e.g., fertilizer use, landscaping practices) on NO3-N and PO4-P transport in urban residential catchments.

  2. Yosemite Conference on Ionospheric Plasma in the Magnetosphere: Sources, Mechanisms and Consequences, meeting report

    NASA Technical Reports Server (NTRS)

    Gallagher, D. L.; Burch, J. L.; Klumpar, D. M.; Moore, T. E.; Waite, J. H., Jr.

    1987-01-01

    The sixth biennial Yosemite topical conference and the first as a Chapman Conference was held on February 3 to 6, 1986. Due to the recent changes in our perception of the dynamics of the ionospheric/magnetospheric system, it was deemed timely to bring researchers together to discuss and contrast the relative importance of solar versus terrestrial sources of magnetospheric plasma. Although the solar wind was once thought to dominate the supply of plasma in the Earth's magnetosphere, it is now thought that the Earth's ionosphere is a significant contributor. Polar wind and other large volume outflows of plasma have been seen at relatively high altitudes over the polar cap and are now being correlated with outflows found in the magnetotail. The auroral ion fountain and cleft ion fountain are examples of ionospheric sources of plasma in the magnetosphere, observed by the Dynamics Explorer 1 (DE 1) spacecraft. The conference was organized into six sessions: four consisting of prepared oral presentations, one poster session, and one session for open forum discussion. The first three oral sessions dealt separately with the three major topics of the conference, i.e., the sources, mechanisms, and consequences of ionospheric plasma in the magnetosphere. A special session of invited oral presentations was held to discuss extraterrestrial ionospheric/magnetospheric plasma processes. The poster session was extended over two evenings during which presenters discussed their papers on a one-on-one basis. The last session of the conferences was reserved for open discussions of those topics or ideas considered most interesting or controversial.

  3. Source Monitoring 15 Years Later: What Have We Learned from fMRI about the Neural Mechanisms of Source Memory?

    ERIC Educational Resources Information Center

    Mitchell, Karen J.; Johnson, Marcia K.

    2009-01-01

    Focusing primarily on functional magnetic resonance imaging (fMRI), this article reviews evidence regarding the roles of subregions of the medial temporal lobes, prefrontal cortex, posterior representational areas, and parietal cortex in source memory. In addition to evidence from standard episodic memory tasks assessing accuracy for neutral…

  4. Resistance to cardiomyocyte hypertrophy in ae3 −/− mice, deficient in the AE3 Cl−/HCO3− exchanger

    PubMed Central

    2014-01-01

    Background Cardiac hypertrophy is central to the etiology of heart failure. Understanding the molecular pathways promoting cardiac hypertrophy may identify new targets for therapeutic intervention. Sodium-proton exchanger (NHE1) activity and expression levels in the heart are elevated in many models of hypertrophy through protein kinase C (PKC)/MAPK/ERK/p90RSK pathway stimulation. Sustained NHE1 activity, however, requires an acid-loading pathway. Evidence suggests that the Cl−/HCO3− exchanger, AE3, provides this acid load. Here we explored the role of AE3 in the hypertrophic growth cascade of cardiomyocytes. Methods AE3-deficient (ae3 −/− ) mice were compared to wildtype (WT) littermates to examine the role of AE3 protein in the development of cardiomyocyte hypertrophy. Mouse hearts were assessed by echocardiography. As well, responses of cultured cardiomyocytes to hypertrophic stimuli were measured. pH regulation capacity of ae3 −/− and WT cardiomyocytes was assessed in cultured cells loaded with the pH-sensitive dye, BCECF-AM. Results ae3 −/− mice were indistinguishable from wild type (WT) mice in terms of cardiovascular performance. Stimulation of ae3 −/− cardiomyocytes with hypertrophic agonists did not increase cardiac growth or reactivate the fetal gene program. ae3 −/− mice are thus protected from pro-hypertrophic stimulation. Steady state intracellular pH (pHi) in ae3 −/− cardiomyocytes was not significantly different from WT, but the rate of recovery of pHi from imposed alkalosis was significantly slower in ae3 −/− cardiomyocytes. Conclusions These data reveal the importance of AE3-mediated Cl−/HCO3− exchange in cardiovascular pH regulation and the development of cardiomyocyte hypertrophy. Pharmacological antagonism of AE3 is an attractive approach in the treatment of cardiac hypertrophy. PMID:25047106

  5. Optical spectrophotometry of oscillations and flickering in AE Aquarii

    NASA Technical Reports Server (NTRS)

    Welsh, William F.; Horne, Keith; Oke, J. B.

    1993-01-01

    We observed rapid variations in the nova-like cataclysmic variable AE Aquarii for 1.7 hr with 4.3 s time resolution using the 30-channel (3227-10494 A) spectrophotometer on the Hale 5 m telescope. The 16.5 and 33.0 s oscillations show a featureless blue spectrum that can be represented by a blackbody with temperature and area much smaller than the accretion disk. Models consisting of the sum of a K star spectrum and a hydrogen slab in LTE at T = 6000-10,000 K can fit the spectrum of AE Aquarii reasonably well. The spectrum of a flare indicates optically thin gas with T = 8000-12,000 K. The energy released by the flare is large compared to typical stellar flares.

  6. A Novel Byte-Substitution Architecture for the AES Cryptosystem.

    PubMed

    Hossain, Fakir Sharif; Ali, Md Liakot

    2015-01-01

    The performance of Advanced Encryption Standard (AES) mainly depends on speed, area and power. The S-box represents an important factor that affects the performance of AES on each of these factors. A number of techniques have been presented in the literature, which have attempted to improve the performance of the S-box byte-substitution. This paper proposes a new S-box architecture, defining it as ultra low power, robustly parallel and highly efficient in terms of area. The architecture is discussed for both CMOS and FPGA platforms, and the pipelined architecture of the proposed S-box is presented for further time savings and higher throughput along with higher hardware resources utilization. A performance analysis and comparison of the proposed architecture is also conducted with those achieved by the existing techniques. The results of the comparison verify the outperformance of the proposed architecture in terms of power, delay and size.

  7. A Novel Byte-Substitution Architecture for the AES Cryptosystem

    PubMed Central

    Hossain, Fakir Sharif; Ali, Md. Liakot

    2015-01-01

    The performance of Advanced Encryption Standard (AES) mainly depends on speed, area and power. The S-box represents an important factor that affects the performance of AES on each of these factors. A number of techniques have been presented in the literature, which have attempted to improve the performance of the S-box byte-substitution. This paper proposes a new S-box architecture, defining it as ultra low power, robustly parallel and highly efficient in terms of area. The architecture is discussed for both CMOS and FPGA platforms, and the pipelined architecture of the proposed S-box is presented for further time savings and higher throughput along with higher hardware resources utilization. A performance analysis and comparison of the proposed architecture is also conducted with those achieved by the existing techniques. The results of the comparison verify the outperformance of the proposed architecture in terms of power, delay and size. PMID:26491967

  8. HARPS spectropolarimetry of Herbig Ae/Be stars

    NASA Astrophysics Data System (ADS)

    Hubrig, S.; Ilyin, I.; Schöller, M.; Lo Curto, G.

    2013-12-01

    Our knowledge of the presence and the strength of magnetic fields in intermediate-mass pre-main-sequence stars remains very poor. We present new magnetic field measurements in six Herbig Ae/Be stars observed with HARPS in spectropolarimetric mode. We downloaded from the European Southern Observatory (ESO) archive the publically available HARPS spectra for six Herbig Ae/Be stars. Wavelength shifts between right- and left-hand side circularly polarised spectra were interpreted in terms of a longitudinal magnetic field , using the moment technique introduced by Mathys. The application of the moment technique to the HARPS spectra allowed us in addition to study the presence of the crossover effect and quadratic magnetic fields. Our search for longitudinal magnetic fields resulted in first detections of weak magnetic fields in the Herbig Ae/Be stars HD 58647 and HD 98922. Further, we confirm the previous tentative detection of a weak magnetic field in HD 104237 by Donati et al. and confirm the previous detection of a magnetic field in the Herbig Ae star HD 190073. Surprisingly, the measured longitudinal magnetic field of HD 190073, < Bz >=91±18 G at a significance level of 5σ is not in agreement with the measurement results of Alecian et al. (2013), < Bz >=-10±20 G, who applied the LSD method to exactly the same data. No crossover effect was detected for any star in the sample. Only for HD 98922 the crossover effect was found to be close to 3σ with a measured value of -4228±1443 km s-1 G. A quadratic magnetic field of the order of 10 kG was detected in HD 98922, and of ˜3.5 kG in HD 104237. Based on data obtained from the ESO Science Archive Facility under requests MSCHOELLER 51301, 51324, 36608-36611.

  9. Circumstellar matter in Herbig AeBe stars

    NASA Astrophysics Data System (ADS)

    Natta, Antonella

    1994-03-01

    I briefly summarize the observational evidence for large envelopes in the immediate environment of Herbig AeBe stars, and the results of star + envelope models. Then, I discuss two alternative possibilities to account for the observed mid-infrared fluxes, namely as the emission of very small grains (VSG) and policyclic aromatic hydrocarbons (PAH) in the envelope, or as due to the emission of circumstellar accretion disks, and suggest how MIR high spatial resolution observations can discriminate between these two hypotheses.

  10. The Use of Seismic Coda to Characterize the Source Mechanisms of Induced Earthquakes

    NASA Astrophysics Data System (ADS)

    Reiter, D. T.; Leidig, M.; Yoo, S.; Mayeda, K. M.

    2012-12-01

    In recent years the injection of wastewater from petroleum production activities into disposal wells has been implicated in some unusual local seismicity. The potential seismic hazard associated with waste fluid disposal wells is so far poorly understood. Improving our understanding of the mechanics and physics of induced earthquakes is an important goal that will help mitigate seismic risk before disposal operations begin. To address this issue we adapted a set of data analysis techniques from seismic nuclear test-ban monitoring to the local scale (i.e., on the order of several spatial kilometers). In this paper we summarize the results of applying some of the methods to data from a temporary deployment of broadband stations surrounding a saltwater disposal well (SWD) near the Dallas-Fort Worth (DFW) airport. The sequence of small events (less than M 3.3) starting in late October 2008 provides a good test bed for the application of in-depth analysis to data recorded on a very sparse seismic network. In particular, we studied the amplitude behavior of the DFW data using the scattered seismic wave field, or so-called "coda", which has unique properties that makes its use ideal for sparse station monitoring at local distances. Because local scattered waves sample the subsurface via multiple reflections and 3-D scattering, amplitude measurements made from coda envelopes reach a steady decay that is purely a function of the average medium properties that encompass the volume surrounding the source and seismic station, irrespective of source size. As such, the scattered waves behave very predictably within a region and can be used for estimates of magnitude and other source-related characteristics (e.g., earthquake stress drop, radiated seismic energy, seismic moment) that are significantly more stable than traditional approaches that utilize the direct waves such as P and S. Because the coda averages over the 3-D crustal heterogeneity as well as the source radiation

  11. Extrasynaptic exocytosis and its mechanisms: a source of molecules mediating volume transmission in the nervous system

    PubMed Central

    Trueta, Citlali; De-Miguel, Francisco F.

    2012-01-01

    We review the evidence of exocytosis from extrasynaptic sites in the soma, dendrites, and axonal varicosities of central and peripheral neurons of vertebrates and invertebrates, with emphasis on somatic exocytosis, and how it contributes to signaling in the nervous system. The finding of secretory vesicles in extrasynaptic sites of neurons, the presence of signaling molecules (namely transmitters or peptides) in the extracellular space outside synaptic clefts, and the mismatch between exocytosis sites and the location of receptors for these molecules in neurons and glial cells, have long suggested that in addition to synaptic communication, transmitters are released, and act extrasynaptically. The catalog of these molecules includes low molecular weight transmitters such as monoamines, acetylcholine, glutamate, gama-aminobutiric acid (GABA), adenosine-5-triphosphate (ATP), and a list of peptides including substance P, brain-derived neurotrophic factor (BDNF), and oxytocin. By comparing the mechanisms of extrasynaptic exocytosis of different signaling molecules by various neuron types we show that it is a widespread mechanism for communication in the nervous system that uses certain common mechanisms, which are different from those of synaptic exocytosis but similar to those of exocytosis from excitable endocrine cells. Somatic exocytosis has been measured directly in different neuron types. It starts after high-frequency electrical activity or long experimental depolarizations and may continue for several minutes after the end of stimulation. Activation of L-type calcium channels, calcium release from intracellular stores and vesicle transport towards the plasma membrane couple excitation and exocytosis from small clear or large dense core vesicles in release sites lacking postsynaptic counterparts. The presence of synaptic and extrasynaptic exocytosis endows individual neurons with a wide variety of time- and space-dependent communication possibilities

  12. SPITZER'S VIEW ON AROMATIC AND ALIPHATIC HYDROCARBON EMISSION IN HERBIG Ae STARS

    SciTech Connect

    Acke, B.; Waters, L. B. F. M.; Bouwman, J.; Juhasz, A.; Henning, Th.; Van den Ancker, M. E.; Meeus, G.; Tielens, A. G. G. M.

    2010-07-20

    The chemistry of astronomical hydrocarbons, responsible for the well-known infrared emission features detected in a wide variety of targets, remains enigmatic. Here we focus on the group of young intermediate-mass Herbig Ae stars. We have analyzed the aliphatic and polycyclic aromatic hydrocarbon (PAH) emission features in the infrared spectra of a sample of 53 Herbig Ae stars, obtained with the Infrared Spectrograph aboard the Spitzer Space Telescope. We confirm that the PAH-to-stellar luminosity ratio is higher in targets with a flared dust disk. However, a few sources with a flattened dust disk still show relatively strong PAH emission. Since PAH molecules trace the gas disk, this indicates that gas disks may still be flared, while the dust disk has settled due to grain growth. There are indications that the strength of the 11.3 {mu}m feature also depends on dust disk structure, with flattened disks being less bright in this feature. We confirm that the CC bond features at 6.2 and 7.8 {mu}m shift to redder wavelengths with decreasing stellar effective temperature. Moreover, we show that this redshift is accompanied by a relative increase of aliphatic CH emission and a decrease of the aromatic 8.6 {mu}m CH feature strength. Cool stars in our sample are surrounded by hydrocarbons with a high aliphatic/aromatic CH ratio and a low aromatic CH/CC ratio, and vice versa for the hot stars. We conclude that, while the overall hydrocarbon emission strength depends on the dust disk's geometry, the relative differences seen in the IR emission features in disks around Herbig Ae stars are mainly due to chemical differences of the hydrocarbon molecules induced by the stellar UV field. Strong UV flux reduces the aliphatic component and emphasizes the spectral signature of the aromatic molecules in the IR spectra.

  13. Multifrequency Acoustic Emissions (AE) for Monitoring the Time Evolution of Microprocesses within Solids

    NASA Astrophysics Data System (ADS)

    Paparo, Gabriele; Gregori, Giovanni P.

    2003-03-01

    Microprocesses occur like chain reactions where bonds progressively yield. The temporal evolution can be tracked by multifrequency AE. Two principle ideas. One relies on time series of AE of increasingly lower frequency. The second compares time histories of every AE event (fixed frequency) with a lognormal distribution: deviations reveal additional parameters, and the tail results modulated by external effects, envisaging what triggers every AE. Natural environmental phenomena are effective feasibility tests, for subsequent laboratory implementation.

  14. The mechanical design and simulation of a scaled H- Penning ion source

    NASA Astrophysics Data System (ADS)

    Rutter, T.; Faircloth, D.; Turner, D.; Lawrie, S.

    2016-02-01

    The existing ISIS Penning H- source is unable to produce the beam parameters required for the front end test stand and so a new, high duty factor, high brightness scaled source is being developed. This paper details first the development of an electrically biased aperture plate for the existing ISIS source and second, the design, simulation, and development of a prototype scaled source.

  15. Sources, atmospheric transport and deposition mechanism of organochlorine pesticides in soils of the Tibetan Plateau.

    PubMed

    Chen, Laiguo; Feng, Qianhua; He, Qiusheng; Huang, Yumei; Zhang, Yu; Jiang, Guo; Zhao, Wei; Gao, Bo; Lin, Kui; Xu, Zhencheng

    2017-01-15

    Because of mountain cold-trapping, the soil in the Tibetan Plateau may be an important global sink of organochlorine pesticides (OCPs). However, there are limited data on OCPs in the soils of the Tibetan Plateau. In addition, the atmospheric transport and deposition mechanisms of OCPs also need to be further studied. In this study, the sampling area covered most regions of the Tibetan Plateau. The detection frequencies of ΣChlordane (sum of trans-chlordane, cis-chlordane and oxychlordane), HCB, ΣNonachlor (sum of trans- and cis-nonachlor), DDTs, ΣEndo (sum of endosulfan-I, endosulfan-II and endosulfate), aldrin, HCHs, ΣHeptachlor (sum of heptachlor and heptachlor epoxide), mirex and dieldrin were 100%, 98.3%, 96.6%, 94.8%, 89.7%, 87.9%, 62.1%, 55.2%, 32.8% and 6.9%, respectively. DDTs (with arithmetic mean values of 1050ngkg(-1) dw) and HCHs (393ngkg(-1)) were the principal OCPs in cultivated soils, whereas ΣEndo (192ngkg(-1)) and ΣChlordane (152ngkg(-1)) were the principal OCPs in non-cultivated soils. Local use of DDTs, dicofol and HCHs may be an important source of OCP accumulation in the soil of the Tibetan Plateau. Aldrin and endosulfan are considered to be good indicators for studying atmospheric transport and deposition of OCPs from South Asia and Southeast Asia. Two zones with high OCP levels were found in the southeast and northwest of the Tibetan Plateau. The zones have dissimilar pollution sources of OCPs and are influenced by different factors that affect their precipitation scavenging efficiency. The amount of precipitation was the dominant factor in the southeast, whereas large differences in temperature and wind speed were the dominant factors in the northwest.

  16. Determining the seismic source mechanism and location for an explosive eruption with limited observational data: Augustine Volcano, Alaska

    USGS Publications Warehouse

    Dawson, P.B.; Chouet, B.A.; Power, J.

    2011-01-01

    Waveform inversions of the very-long-period components of the seismic wavefield produced by an explosive eruption that occurred on 11 January, 2006 at Augustine Volcano, Alaska constrain the seismic source location to near sea level beneath the summit of the volcano. The calculated moment tensors indicate the presence of a volumetric source mechanism. Systematic reconstruction of the source mechanism shows the source consists of a sill intersected by either a sub-vertical east-west trending dike or a sub-vertical pipe and a weak single force. The trend of the dike may be controlled by the east-west trending Augustine-Seldovia arch. The data from the network of broadband sensors is limited to fourteen seismic traces, and synthetic modeling confirms the ability of the network to recover the source mechanism. The synthetic modeling also provides a guide to the expected capability of a broadband network to resolve very-long-period source mechanisms, particularly when confronted with limited observational data. Copyright 2011 by the American Geophysical Union.

  17. Determining the seismic source mechanism and location for an explosive eruption with limited observational data: Augustine Volcano, Alaska

    NASA Astrophysics Data System (ADS)

    Dawson, Phillip B.; Chouet, Bernard A.; Power, John

    2011-02-01

    Waveform inversions of the very-long-period components of the seismic wavefield produced by an explosive eruption that occurred on 11 January, 2006 at Augustine Volcano, Alaska constrain the seismic source location to near sea level beneath the summit of the volcano. The calculated moment tensors indicate the presence of a volumetric source mechanism. Systematic reconstruction of the source mechanism shows the source consists of a sill intersected by either a sub-vertical east-west trending dike or a sub-vertical pipe and a weak single force. The trend of the dike may be controlled by the east-west trending Augustine-Seldovia arch. The data from the network of broadband sensors is limited to fourteen seismic traces, and synthetic modeling confirms the ability of the network to recover the source mechanism. The synthetic modeling also provides a guide to the expected capability of a broadband network to resolve very-long-period source mechanisms, particularly when confronted with limited observational data.

  18. Fan-head shear rupture mechanism as a source of off-fault tensile cracking

    NASA Astrophysics Data System (ADS)

    Tarasov, Boris

    2016-04-01

    ; behind this zone static microcracks are left in the wake of the propagating rupture. Unfortunately, the modern technology used in these experiments is not able to identify the shear rupture mechanism itself operated within the narrow rupture interface. However, a special analysis of side effects accompanying the shear rupture propagation (including the off-fault tensile cracking) allows supposing that the failure process was governed by the fan-mechanism. 1. Tarasov, B.G. 2014. Hitherto unknown shear rupture mechanism as a source of instability in intact hard rocks at highly confined compression. Tectonophysics, 621, 69-84. 2. Griffith, W.A., Rosakis, A., Pollard, D.D. and Ko, C.W., 2009. Dynamic rupture experiments elucidate tensile crack development during propagating earthquake ruptures, Geology, pp 795-798. 3. Ngo, D., Huang, Y., Rosakis, A., Griffith, W.A., Pollard D. 2012. Off-fault tensile cracks: A link between geological fault observations, lab experiments, and dynamic rupture models. Journal of Geophysical Research, vol. 117, B01307, doi: 10.1029/2011JB008577 (2012).

  19. Einstein X-ray observations of Herbig Ae/Be stars

    NASA Technical Reports Server (NTRS)

    Damiani, F.; Micela, G.; Sciortino, S.; Harnden, F. R., Jr.

    1994-01-01

    We have investigated the X-ray emission from Herbig Ae/Be stars, using the full set of Einstein Imaging Proportional Counter (IPC) observations. Of a total of 31 observed Herbig stars, 11 are confidently identified with X-ray sources, with four additonal dubious identifications. We have used maximum likelihood luminosity functions to study the distribution of X-ray luminosity, and we find that Be stars are significantly brighter in X-rays than Ae stars and that their X-ray luminosity is independent of projected rotational velocity v sin i. The X-ray emission is instead correlated with stellar bolometric luminosity and with effective temperature, and also with the kinetic luminosity of the stellar wind. These results seem to exclude a solar-like origin for the X-ray emission, a possibility suggested by the most recent models of Herbig stars' structure, and suggest an analogy with the X-ray emission of O (and early B) stars. We also observe correlations between X-ray luminosity and the emission at 2.2 microns (K band) and 25 microns, which strengthen the case for X-ray emission of Herbig stars originating in their circumstellar envelopes.

  20. Sodium Laser Guide Star Adaptive Optics Imaging Polarimetry of Herbig Ae/Be Stars

    SciTech Connect

    Perrin, M D; Graham, J R; Lloyd, J P; Kalas, P; Gates, E L; Gavel, D T; Pennington, D M; Max, C E

    2004-01-08

    The future of high-resolution ground-based optical and infrared astronomy requires the successful implementation of laser guide star adaptive optics systems. We present the first science results from the Lick Observatory sodium beacon laser guide star system. By coupling this system to a near-infrared (J;H;Ks bands) dual-channel imaging polarimeter, we achieve very high sensitivity to light scattered in the circumstellar enviroment of Herbig Ae/Be stars on scales of 100-300 AU. Observations of LkH{alpha} 198 reveal a highly polarized, biconical nebula 10 arcseconds in diameter (6000 AU) . We also observe a polarized jet-like feature associated with the deeply embedded source LkH{alpha} 198-IR. The star LkH{alpha} 233 presents a narrow, unpolarized dark lane dividing its characteristic butterfly-shaped polarized reflection nebulosity. This linear structure is oriented perpendicular to an optical jet and bipolar cavity and is consistent with the presence of an optically thick circumstellar disk blocking our direct view of the star. These data suggest that the evolutionary picture developed for the lower-mass T Tauri stars is also relevant to the Herbig Ae/Be stars and demonstrate the ability of laser guide star adaptive optics systems to obtain scientific results competitive with natural guide star adaptive optics or space-based telescopes.

  1. Quantification of immobilized Candida antarctica lipase B (CALB) using ICP-AES combined with Bradford method.

    PubMed

    Nicolás, Paula; Lassalle, Verónica L; Ferreira, María L

    2017-02-01

    The aim of this manuscript was to study the application of a new method of protein quantification in Candida antarctica lipase B commercial solutions. Error sources associated to the traditional Bradford technique were demonstrated. Eight biocatalysts based on C. antarctica lipase B (CALB) immobilized onto magnetite nanoparticles were used. Magnetite nanoparticles were coated with chitosan (CHIT) and modified with glutaraldehyde (GLUT) and aminopropyltriethoxysilane (APTS). Later, CALB was adsorbed on the modified support. The proposed novel protein quantification method included the determination of sulfur (from protein in CALB solution) by means of Atomic Emission by Inductive Coupling Plasma (AE-ICP). Four different protocols were applied combining AE-ICP and classical Bradford assays, besides Carbon, Hydrogen and Nitrogen (CHN) analysis. The calculated error in protein content using the "classic" Bradford method with bovine serum albumin as standard ranged from 400 to 1200% when protein in CALB solution was quantified. These errors were calculated considering as "true protein content values" the results of the amount of immobilized protein obtained with the improved method. The optimum quantification procedure involved the combination of Bradford method, ICP and CHN analysis.

  2. Laser guide star adaptive optics imaging polarimetry of Herbig Ae/Be stars

    NASA Astrophysics Data System (ADS)

    Perrin, Marshall D.; Graham, James R.; Kalas, Paul; Lloyd, James P.; Max, Claire E.; Gavel, Donald T.; Pennington, Deanna M.; Gates, Elinor L.

    2004-10-01

    Current and future large telescopes depend critically on laser guide star adaptive optics (LGS AO) to achieve their scientific goals. However, there are still relatively few scientific results reported from existing LGS AO systems. We present some of the first science results from the Lick Observatory sodium beacon LGS AO system. We achieve high sensitivity to light scattered in the circumstellar enviroment of Herbig Ae/Be stars on scales of 100-200 AU by coupling the LGS AO system to a near-infrared (J,H,Ks bands) dual channel imaging polarimeter. We describe the design, implementation, and performance of this instrument. The dominant noise source near bright stars in AO images is a "seeing halo" of uncorrected speckles, and since these speckles are unpolarized, dual-channel polarimetry achieves a significant contrast gain. Our observations reveal a wide range of morphologies, including bipolar nebulosities with and without outflow-evacuated cavities and disk-mediated interaction among members of a binary. These data suggest that the evolutionary picture developed for the lower-mass T Tauri stars is also relevant to the Herbig Ae/Be stars, and demonstrate the ability of LGS AO systems to enhance the scientific capabilities of even modest sized telescopes.

  3. Mechanisms of survival, responses and sources of Salmonella in low-moisture environments

    PubMed Central

    Finn, Sarah; Condell, Orla; McClure, Peter; Amézquita, Alejandro; Fanning, Séamus

    2013-01-01

    Some Enterobacteriaceae possess the ability to survive in low-moisture environments for extended periods of time. Many of the reported food-borne outbreaks associated with low-moisture foods involve Salmonella contamination. The control of Salmonella in low-moisture foods and their production environments represents a significant challenge for all food manufacturers. This review summarizes the current state of knowledge with respect to Salmonella survival in intermediate- and low-moisture food matrices and their production environments. The mechanisms utilized by this bacterium to ensure their survival in these dry conditions remain to be fully elucidated, however, in depth transcriptomic data is now beginning to emerge regarding this observation. Earlier research work described the effect(s) that low-moisture can exert on the long-term persistence and heat tolerance of Salmonella, however, data are also now available highlighting the potential cross-tolerance to other stressors including commonly used microbicidal agents. Sources and potential control measures to reduce the risk of contamination will be explored. By extending our understanding of these geno- and phenotypes, we may be able to exploit them to improve food safety and protect public health. PMID:24294212

  4. SOME APPLICATIONS OF SEISMIC SOURCE MECHANISM STUDIES TO ASSESSING UNDERGROUND HAZARD.

    USGS Publications Warehouse

    McGarr, A.; ,

    1984-01-01

    Various measures of the seismic source mechanism of mine tremors, such as magnitude, moment, stress drop, apparent stress, and seismic efficiency, can be related directly to several aspects of the problem of determining the underground hazard arising from strong ground motion of large seismic events. First, the relation between the sum of seismic moments of tremors and the volume of stope closure caused by mining during a given period can be used in conjunction with magnitude-frequency statistics and an empirical relation between moment and magnitude to estimate the maximum possible sized tremor for a given mining situation. Second, it is shown that the 'energy release rate,' a commonly-used parameter for predicting underground seismic hazard, may be misleading in that the importance of overburden stress, or depth, is overstated. Third, results involving the relation between peak velocity and magnitude, magnitude-frequency statistics, and the maximum possible magnitude are applied to the problem of estimating the frequency at which design limits of certain underground support equipment are likely to be exceeded.

  5. Growth mechanisms of GaAs nanowires by gas source molecular beam epitaxy

    NASA Astrophysics Data System (ADS)

    Plante, M. C.; LaPierre, R. R.

    2006-01-01

    GaAs nanowires were grown on GaAs (1 1 1)B substrates in a gas source molecular beam epitaxy system, using self-assembled Au particles with diameters between 20 and 800 nm as catalytic agents. The growth kinetics of the wires was investigated for substrate temperatures between 500 and 600 °C, and V/III flux ratios of 1.5 and 2.3. The broad distribution of Au particles enabled the first observation of two distinct growth regimes related to the size of the catalyst. The origins of this transition are discussed in terms of the various mass transport mechanisms that drive the wire growth. Diffusion of the growth species on the 2-D surface and up the wire sidewalls dominates for catalyst diameters smaller than ˜130 nm on average, while direct impingement on the catalyst followed by bulk diffusion through the Au particle appears to sustain the wire growth for larger catalyst diameters. A change in wire sidewall facets, indicating a probable transition in the crystal structure, is found to be primarily dependent on the V/III flux ratio.

  6. The mechanical design and simulation of a scaled H{sup −} Penning ion source

    SciTech Connect

    Rutter, T. Faircloth, D.; Turner, D.; Lawrie, S.

    2016-02-15

    The existing ISIS Penning H{sup −} source is unable to produce the beam parameters required for the front end test stand and so a new, high duty factor, high brightness scaled source is being developed. This paper details first the development of an electrically biased aperture plate for the existing ISIS source and second, the design, simulation, and development of a prototype scaled source.

  7. Earthquake source mechanisms and transform fault tectonics in the Gulf of California

    NASA Technical Reports Server (NTRS)

    Goff, John A.; Bergman, Eric A.; Solomon, Sean C.

    1987-01-01

    The source parameters of 19 earthquakes in the Gulf of California were determined from an inversion of long-period P and SH waveforms. The inversion procedure is described and the estimated precision of the derived source parameters is examined, with particular attention given to source complexity, the resolution of slip vector azimuth, and the resolution of centroid depth. The implications of these earthquake source characteristics for the tectonic evolution of the gulf are discussed.

  8. Mid-IR Spectra Herbig Ae/Be Stars

    NASA Technical Reports Server (NTRS)

    Wooden, Diane; Witteborn, Fred C. (Technical Monitor)

    1997-01-01

    Herbig Ae/Be stars are intermediate mass pre-main sequence stars, the higher mass analogues to the T Tauri stars. Because of their higher mass, they are expected form more rapidly than the T Tauri stars. Whether the Herbig Ae/Be stars accrete only from collapsing infalling envelopes or whether accrete through geometrically flattened viscous accretion disks is of current debate. When the Herbig Ae/Be stars reach the main sequence they form a class called Vega-like stars which are known from their IR excesses to have debris disks, such as the famous beta Pictoris. The evolutionary scenario between the pre-main sequence Herbig Ae/Be stars and the main sequence Vega-like stars is not yet revealed and it bears on the possibility of the presence of Habitable Zone planets around the A stars. Photometric studies of Herbig Ae/Be stars have revealed that most are variable in the optical, and a subset of stars show non-periodic drops of about 2 magnitudes. These drops in visible light are accompanied by changes in their colors: at first the starlight becomes reddened, and then it becomes bluer, the polarization goes from less than 0.1 % to roughly 1% during these minima. The theory postulated by V. Grinnin is that large cometary bodies on highly eccentric orbits occult the star on their way to being sublimed, for systems that are viewed edge-on. This theory is one of several controversial theories about the nature of Herbig Ae/Be stars. A 5 year mid-IR spectrophotometric monitoring campaign was begun by Wooden and Butner in 1992 to look for correlations between the variations in visible photometry and mid-IR dust emission features. Generally the approximately 20 stars that have been observed by the NASA Ames HIFOGS spectrometer have been steady at 10 microns. There are a handful, however, that have shown variable mid-IR spectra, with 2 showing variations in both the continuum and features anti-correlated with visual photometry, and 3 showing variations in the emission

  9. Evaluation of potential sources and transport mechanisms of fecal indicator bacteria to beach water, Murphy Park Beach, Door County, Wisconsin

    USGS Publications Warehouse

    Juckem, Paul F.; Corsi, Steven R.; McDermott, Colleen; Kleinheinz, Gregory; Fogarty, Lisa R.; Haack, Sheridan K.; Johnson, Heather E.

    2013-01-01

    Fecal Indicator Bacteria (FIB) concentrations in beach water have been used for many years as a criterion for closing beaches due to potential health concerns. Yet, current understanding of sources and transport mechanisms that drive FIB occurrence remains insufficient for accurate prediction of closures at many beaches. Murphy Park Beach, a relatively pristine beach on Green Bay in Door County, Wis., was selected for a study to evaluate FIB sources and transport mechanisms. Although the relatively pristine nature of the beach yielded no detection of pathogenic bacterial genes and relatively low FIB concentrations during the study period compared with other Great Lakes Beaches, its selection limited the number of confounding FIB sources and associated transport mechanisms. The primary sources of FIB appear to be internal to the beach rather than external sources such as rivers, storm sewer outfalls, and industrial discharges. Three potential FIB sources were identified: sand, swash-zone groundwater, and Cladophora mats. Modest correlations between FIB concentrations in these potential source reservoirs and FIB concentrations at the beach from the same day illustrate the importance of understanding transport mechanisms between FIB sources and the water column. One likely mechanism for transport and dispersion of FIB from sand and Cladophora sources appears to be agitation of Cladophora mats and erosion of beach sand due to storm activity, as inferred from storm indicators including turbidity, wave height, current speed, wind speed, sky visibility, 24-hour precipitation, and suspended particulate concentration. FIB concentrations in beach water had a statistically significant relation (p-value ‹0.05) with the magnitude of these storm indicators. In addition, transport of FIB in swash-zone groundwater into beach water appears to be driven by groundwater recharge associated with multiday precipitation and corresponding increased swash-zone groundwater discharge at

  10. Subaru Near-Infrared Imaging of Herbig Ae Stars

    NASA Astrophysics Data System (ADS)

    Fukagawa, Misato; Tamura, Motohide; Itoh, Yoichi; Oasa, Yumiko; Kudo, Tomoyuki; Hayashi, Saeko S.; Kato, Eri; Ootsubo, Takafumi; Itoh, Yusuke; Shibai, Hiroshi; Hayashi, Masahiko

    2010-04-01

    We report results of H-band (λ = 1.65μm) imaging observations of young intermediate-mass stars using the Subaru 8.2-m Telescope with the adaptive optics AO36 and the infrared coronagraph CIAO. The targets consist of 16 Herbig Ae/Be stars (15 Herbig Ae stars and one Herbig Be star) and four additional main-sequence stars with infrared excesses. Five protoplanetary disks have been spatially resolved around the Herbig Ae stars with ages of 2-8 Myr. The resolved disks have outer radii of several 100 AU, and their surface brightnesses range from 10 mag arcsec-2 to 18 mag arcsec-2. The images reveal various morphologies in optically thick disks: spiral arms around AB Aur, a banana-split structure with an outer arm for HD 142527, a compact circumprimary disk of HD 150193, a faint discontinuous ring around HD 163296, and an unstructured face-on disk of HD 169142. The detection of an optically thick disk in scattered light implies that it is vertically flared, and intercepts stellar light at least in the outer region where those images were obtained. However, the surface brightness distribution, the resolved structure, and other observational characteristics suggest that the disks are unlikely to be continuously flared young disks with small grains well mixed with gas. The detection rate and the disk brightness do not correlate with the stellar age and the disk mass, but there is a tendency that the brightest disks are still surrounded by long-lived envelopes (AB Aur, HD 100546, HD 142527). The significant diversity of the disk structure can be attributed to the multiplicity and the initial condition of the local star-forming environments. The detections of companion candidates around our targeted stars are also reported.

  11. The AE9/AP9 Next Generation Radiation Specification Models

    NASA Astrophysics Data System (ADS)

    O'Brien, Paul; Ginet, Gregory; Huston, Stuart; Byers, David

    A significant effort is under way to develop the next-generation trapped proton and electron models for satellite design, AP-9 and AE-9, respectively. The primary objectives of the effort are to 1) improve the overall accuracy of the models; 2) provide indicators of the uncertainty in the model due to natural variability and instrument uncertainty; 3) cover a broad energy range including hot plasma, relativistic electrons and highly energetic protons; and 4) provide complete spatial coverage. In this paper we will present background, demonstration and initial feedback from a limited-release beta version of the model.

  12. [Determination of trace elements in beans by ICP-AES].

    PubMed

    Wang, Ying; Xin, Shi-gang

    2004-02-01

    In this paper,the contents of trace elements in beans such as Ca, Mg, Mn, Sr, Fe, Co, Ni, Se and Ba were determined by ICP-AES uing nitrifying method of high pressure nitrifying pot, and compared with the results of wet method. The two methods showed no obvious differences. The method proves to be simple, rapid, highly sensitive, accurate and can be used to determine many elements at the same time. In addition, there was little environment pollution. Its recovery is 96.8%-102%, and relative standard deviation is 3.35%.

  13. STS-80 Payload WSF-3 in Hanger AE (side view)

    NASA Technical Reports Server (NTRS)

    2000-01-01

    In NASA's Building AE on Cape Canaveral Air Station, the Wake Shield Facility-3 (WSF-3) is just about ready for flight. The WSF-3 and the other primary payload of Space Shuttle Mission STS- 80, the Orbiting and Retrievable Far and Extreme Ultraviolet Spectrograph-Shuttle Pallet Satellite (ORFEUS-SPAS), will make the trip to Launch Pad 39B together, with the transfer scheduled to occur on Oct. 11. There they will await the arrival of the Space Shuttle Columbia to be installed in the orbiter payload bay. Columbia is scheduled to lift off on Mission STS-80 around Nov. 8.

  14. Using patient passports to improve A&E asthma care.

    PubMed

    Newell, Karen; Bunce, Rebecca; Hume, Shenagh

    The asthma patient passport (APP) is a patient-specific asthma plan that details what to do when asthma is out of control. It helps patients who have severe, difficult-to-manage asthma, and health professionals when these patients present at accident and emergency. This article shows that, while the APP acts as a patient's advocate, it also facilitates accessing emergency care by making it more streamlined. Case studies explore why people with asthma have avoided going to A&E, putting their lives at risk, and provide an insight into how difficult it can be for people to navigate the healthcare system when they are at their most vulnerable.

  15. Phases of Ba adsorption on Si(100)-(2×1) studied by LEED and AES

    NASA Astrophysics Data System (ADS)

    Hu, Xiaoming; Peterson, C. A.; Sarid, D.; Yu, Z.; Wang, J.; Marshall, D. S.; Droopad, R.; Hallmark, J. A.; Ooms, W. J.

    1999-05-01

    Phase transitions of Ba adsorption on a clean Si(001)-(2×1) studied by low energy electron diffraction (LEED) and Auger electron spectroscopy (AES) are reported. The depositions of the Ba were performed with (a) the substrate held at room temperature followed by annealing at elevated temperatures, and (b) the substrate held at 900°C. While confirming earlier established phases, the existence of 4× streaks in the (3×2)+c(6×2) and (2×1) phases has been identified. Also found was a real-time phase transition from a (3×2) phase to a mixture of (3×2) and c(6×2) phases during sample cooling. Finally, it was found that AES of Ba/Si peak ratios exhibit plateaus in the phase vs. temperature diagram for the (3×2), (3×2)+c(6×2), and (2×1)+4× streak phases, indicating a temperature-dependent mechanism limiting the Ba coverage.

  16. Effect of Deep Cryogenic Treatment on Microstructure and Properties of AE42 Mg Alloy

    NASA Astrophysics Data System (ADS)

    Bhale, Pranav; Shastri, H.; Mondal, A. K.; Masanta, M.; Kumar, S.

    2016-09-01

    The effect of deep cryogenic treatment (DCT) on microstructure and mechanical properties including corrosion behavior of the squeeze-cast AE42 alloy has been investigated. For comparison, the same has also been studied on the untreated alloy. Both the untreated and deep cryogenic-treated (DCTed) alloys comprised α-Mg and Al4RE phases. Volume fraction of the Al4RE phase in the AE42 alloy reduced gradually following DCT carried out from 4 to 16 h. Ductility and UTS increase significantly with a marginal increase in YS of all the DCTed alloys. The improvement was attributed to the dissolution of the brittle Al4RE phase following DCT. Among the alloys employed, the best tensile properties were obtained for the 16-h DCT alloy due to its lowest content of the brittle Al4RE phase. Creep resistance of the DCTed alloys was lower than that of the untreated alloy owing to the presence of less amount of thermally stable intermetallic Al4RE phase. Wear resistance of the alloy reduces following DCT due to reduced hardness of the DCTed alloys. The untreated alloy exhibits the best corrosion resistance, whereas poor corrosion resistance of the DCTed alloys is attributed to the reduced amount of Al4RE phase that fails to built a corrosion resistance barrier.

  17. Characterization of fold defects in AZ91D and AE42 magnesium alloy permanent mold castings

    SciTech Connect

    Bichler, L.; Ravindran, C.

    2010-03-15

    Casting premium-quality magnesium alloy components for aerospace and automotive applications poses unique challenges. Magnesium alloys are known to freeze rapidly prior to filling a casting cavity, resulting in misruns and cold shuts. In addition, melt oxidation, solute segregation and turbulent metal flow during casting contribute to the formation of fold defects. In this research, formation of fold defects in AZ91D and AE42 magnesium alloys cast via the permanent mold casting process was investigated. Computer simulations of the casting process predicted the development of a turbulent metal flow in a critical casting region with abrupt geometrical transitions. SEM and light optical microscopy examinations revealed the presence of folds in this region for both alloys. However, each alloy exhibited a unique mechanism responsible for fold formation. In the AZ91D alloy, melt oxidation and velocity gradients in the critical casting region prevented fusion of merging metal front streams. In the AE42 alloy, limited solubility of rare-earth intermetallic compounds in the {alpha}-Mg phase resulted in segregation of Al{sub 2}RE particles at the leading edge of a metal front and created microstructural inhomogeneity across the fold.

  18. Earthquakes in the Orozco transform zone: seismicity, source mechanisms, and tectonics

    USGS Publications Warehouse

    Trehu, Anne M.; Solomon, Sean C.

    1983-01-01

    As part of the Rivera Ocean Seismic Experiment, a network of ocean bottom seismometers and hydrophones was deployed in order to determine the seismic characteristics of the Orozco transform fault in the central eastern Pacific. We present hypocentral locations and source mechanisms for 70 earthquakes recorded by this network. All epicenters are within the transform region of the Orozco Fracture Zone and clearly delineate the active plate boundary. About half of the epicenters define a narrow line of activity parallel to the spreading direction and situated along a deep topographic trough that forms the northern boundary of the transform zone (region 1). Most focal depths for these events are very shallow, within 4 km of the seafloor; several well-determined focal depths, however, are as great as 7 km. No shallowing of seismic activity is observed as the rise-transform intersection is approached; to the contrary, the deepest events are within 10 km of the intersection. First motion polarities for most of the earthquakes in region 1 are compatible with right-lateral strike slip faulting along a nearly vertical plane, striking parallel to the spreading direction. Another zone of activity is observed in the central part of the transform (region 2). The apparent horizontal and vertical distribution of activity in this region is more scattered than in the first, and the first motion radiation patterns of these events do not appear to be compatible with any known fault mechanism. Pronounced lateral variations in crustal velocity structure are indicated for the transform region from refraction data and measurements of wave propagation directions. The effect of this lateral heterogeneity on hypocenters and fault plane solutions is evaluated by tracing rays through a three-dimensional velocity grid. While findings for events in region 1 are not significantly affected, in region 2, epicentral mislocations of up to 10 km and azimuthal deflections of up to 45° may result from

  19. Immunologic biomarkers in prostate cancer: the AE37 paradigm.

    PubMed

    Baxevanis, Constantin N; Papamichail, Michael; Perez, Sonia A

    2014-01-01

    One major achievement in cancer therapy is to select patients who will most likely benefit from a specific treatment. Predictive biomarkers play an important role in this respect being already useful in management of breast cancer and melanoma. For example, HER-2/neu (HER-2) overexpression selects for breast cancer patients to be treated with trastuzumab, and BRAFV600E mutations select for melanoma patients to be treated with vemurafenib. Identification of factors associated with T cell responsiveness to vaccination remains critical. Pre-existent immunity and circulating suppressor cells may regulate the levels of vaccine-specific T cell immunity after vaccination. The identification of immunologic endpoints to immunotherapy would thus considerably help guide the development of immunotherapy-based clinical trials. This commentary is based on a retrospective analysis we performed of data from prostate cancer patients vaccinated and boosted with the AE37 vaccine. The aim of these exploratory analyses was to identify factors useful in predicting which patients are more likely to respond to the treatment under study. The issue we are addressing here is to which extent common variables used pre- and/or following vaccinations with AE37 to assess the immune response status of the prostate cancer patients, may predict overall survival.

  20. Decryption-decompression of AES protected ZIP files on GPUs

    NASA Astrophysics Data System (ADS)

    Duong, Tan Nhat; Pham, Phong Hong; Nguyen, Duc Huu; Nguyen, Thuy Thanh; Le, Hung Duc

    2011-10-01

    AES is a strong encryption system, so decryption-decompression of AES encrypted ZIP files requires very large computing power and techniques of reducing the password space. This makes implementations of techniques on common computing system not practical. In [1], we reduced the original very large password search space to a much smaller one which surely containing the correct password. Based on reduced set of passwords, in this paper, we parallel decryption, decompression and plain text recognition for encrypted ZIP files by using CUDA computing technology on graphics cards GeForce GTX295 of NVIDIA, to find out the correct password. The experimental results have shown that the speed of decrypting, decompressing, recognizing plain text and finding out the original password increases about from 45 to 180 times (depends on the number of GPUs) compared to sequential execution on the Intel Core 2 Quad Q8400 2.66 GHz. These results have demonstrated the potential applicability of GPUs in this cryptanalysis field.

  1. Immunogenetics of the A-E alloantigen complex.

    PubMed

    Kopti, F; Briles, R W; Briles, W E

    1997-12-01

    The close linkage (0.5%) between the A and E erythrocyte alloantigen loci present a special challenge in the production of locus-specific typing antisera. The objective of the investigation was to determine immunogenetically the A-E haplotypes (genetically linked combinations of A and E antigens) existing in the locally maintained individuals of the New Hampshire (NH) and White Plymouth Rock (WR) breeds. The A and E alloantigens in these populations were identified using reference antisera previously produced in White Leghorns. A total of four A-E haplotypes were identified within each of the two breeds; A2E1, A6E2, A6E4, and A8E2 in WR and A2E1, A3E7, A7E4, and A8E2 in NH. Individuals of these two brown-egg breeds were backcrossed over several generations to a line of Ancona chickens homozygous at the A and E loci. Genetic segregation occurring over four generations resulted in nonrecombinant and recombinant progeny that were immunized reciprocally with the blood of siblings to raise antibodies reactive with the individual A and E antigens of the NH and WR stocks. The antisera resulting from the within-family alloimmunizations confirmed the haplotypes deduced in the WR and NH lines from the initial tests with the A and E reference antisera.

  2. The AE9/AP9/SPM Next Generation Radiation Specification Models - Progress Report

    NASA Astrophysics Data System (ADS)

    O'Brien, Paul; Johnston, William Robert; Huston, Stuart; Guild, Timothy

    2016-07-01

    The AE9/AP9/SPM model has now been released to the global satellite design community, with a recent update to version 1.2. We are working on incorporating new data sources, such as AZUR and NASA's Van Allen Probes, while also addressing critiques raised by the science and engineering communities. In particular, we are investigating discrepancies for protons at low altitude and electrons at geostationary altitudes. Finally, we are scoping out architectural improvements to enable features requested by industry: improved stitching between the plasma and radiation models, local time dependence in the plasma model, longitude dependence in the electron radiation model, and solar cycle variation in the low altitude protons. We provide a brief update on the status of the model, discrepancy investigations, and plans for the future.

  3. A new electrical and mechanically detonatable shear wave source for near surface (0-30 m) seismic acquisition

    NASA Astrophysics Data System (ADS)

    Crane, J. M.; Lorenzo, J. M.; Harris, J. B.

    2013-04-01

    We present a new, impulsive, horizontal shear source capable of performing long shot profiles in a time-efficient and repeatable manner. The new shear source is ground-coupled by eight 1/2″ (1.27 cm) × 2″ (5.08 cm) steel spikes. Blank shotshells (12-gauge) used as energy sources can be either mechanically or electrically detonated. Electrical fuses have a start time repeatability of < 50 μs. This source can be operated by a single individual, and takes only ~ 10 s between shots as opposed to ~ 30 s for six stacked hammer blows. To ensure complete safety, the shotshell holder is surrounded by a protective 6″ (15.24 cm)-thick barrel, a push-and-twist-locked breach, and a safety pin. We conducted field tests at the 17th Street Canal levee breach site in New Orleans, Louisiana (30.017° N 90.121° W) and at an instrumented test borehole at Millsaps College in Jackson, Mississippi (32.325° N 93.182° W) to compare our new source and a traditional hammer impact source. The new shear source produces a broader-band of frequencies (30-100 Hz cf. 30-60 Hz). Signal generated by the new shear source has signal-to-noise ratios equivalent to ~ 3 stacked hammer blows to the hammer impact source. Ideal source signals must be broadband in frequency, have a high SNR, be consistent, and have precise start times; all traits of the new shear source.

  4. Near-field beamforming analysis for acoustic emission source localization.

    PubMed

    He, Tian; Pan, Qiang; Liu, Yaoguang; Liu, Xiandong; Hu, Dayong

    2012-07-01

    This paper attempts to introduce a near-field acoustic emission (AE) beamforming method to estimate the AE source locations by using a small array of sensors closely placed in a local region. The propagation characteristics of AE signals are investigated based on guided wave theory to discuss the feasibility of using beamforming techniques in AE signal processing. To validate the effectiveness of the AE beamforming method, a series of pencil lead break tests at various regions of a thin steel plate are conducted. The potential of this method for engineering applications are explored through rotor-stator rubbing tests. The experimental results demonstrate that the proposed method can effectively determine the region where rubbing occurs. It is expected that the work of this paper may provide a helpful analysis tool for near-field AE source localization.

  5. Toward a probabilistic acoustic emission source location algorithm: A Bayesian approach

    NASA Astrophysics Data System (ADS)

    Schumacher, Thomas; Straub, Daniel; Higgins, Christopher

    2012-09-01

    Acoustic emissions (AE) are stress waves initiated by sudden strain releases within a solid body. These can be caused by internal mechanisms such as crack opening or propagation, crushing, or rubbing of crack surfaces. One application for the AE technique in the field of Structural Engineering is Structural Health Monitoring (SHM). With piezo-electric sensors mounted to the surface of the structure, stress waves can be detected, recorded, and stored for later analysis. An important step in quantitative AE analysis is the estimation of the stress wave source locations. Commonly, source location results are presented in a rather deterministic manner as spatial and temporal points, excluding information about uncertainties and errors. Due to variability in the material properties and uncertainty in the mathematical model, measures of uncertainty are needed beyond best-fit point solutions for source locations. This paper introduces a novel holistic framework for the development of a probabilistic source location algorithm. Bayesian analysis methods with Markov Chain Monte Carlo (MCMC) simulation are employed where all source location parameters are described with posterior probability density functions (PDFs). The proposed methodology is applied to an example employing data collected from a realistic section of a reinforced concrete bridge column. The selected approach is general and has the advantage that it can be extended and refined efficiently. Results are discussed and future steps to improve the algorithm are suggested.

  6. Transformation of AeIn4 Indides (Ae = Ba, Sr) into an AeAu2In2 Structure Type Through Gold Substitution

    SciTech Connect

    Dai, Jing-Cao; Corbett, John D.

    2007-04-17

    The title compounds were prepared from the elements by high-temperature solid-state synthesis techniques. X-ray structural analyses shows that BaAu{sub 2}In{sub 2} (1) and SrAu{sub 2}In{sub 2} (2) crystallize in a new orthorhombic structure, Pnma, Z = 4 (a = 8.755(2), 8.530(2) {angstrom}; b = 4.712(1), 4.598(1) {angstrom}; c = 12.368(3), 12.283(4) {angstrom}, respectively). Gold substitutes for 50% of the indium atoms in the tetragonal BaIn{sub 4} and monoclinic SrIn{sub 4} parents to give this new and more flexible orthorhombic structure. The Ae atoms in this structure are contained within chains of hexagonal prisms built of alternating In and Au that have additional augmenting atoms around their waists from further condensation of parallel displaced chains. The driving forces for these structural changes are in part the shorter Au-In distances (2.72 and 2.69 {angstrom}) relative to d(In-In) in the parents, presumably because of relativistic contractions with Au. Generalities about such centered prismatic building blocks and their condensation modes in these and related phases are described. Band structure calculations (EHTB) demonstrate that the two compounds are metallic, which is confirmed by measurements of the resistivity of 1 and the magnetic susceptibilities of both.

  7. Two mechanisms forming a comblike step pattern induced by a moving linear adatom source

    NASA Astrophysics Data System (ADS)

    Sato, Masahide; Miura, Hitoshi; Uwaha, Makio

    2017-03-01

    We carry out phase field simulations to study properties of the comblike step patterns induced by an adatom source. When an adatom source advances right in front of a step, step wandering is caused by the asymmetry of the surface diffusion field and small protrusions are formed. If the velocity of the source Vp is smaller than a critical value Vpc, the protrusions follow the adatom source with coarsening of the step pattern, and a regular comblike pattern with finger-like protrusions is formed. With a sufficiently small Vp, the gap of the supersaturation is large at the adatom source. Since the period of protrusions, Λ , decreases with increasing Vp, the coarsening of step pattern is irrelevant for the protrusions to catch up with the adatom source. Near Vpc, the gap of the supersaturation at the adatom source is small. Taking account of the increase in Λ with increasing Vp, the coarsening of the step pattern is essential for the protrusions to follow the adatom source.

  8. Mechanisms Supporting Superior Source Memory for Familiar Items: A Multi-Voxel Pattern Analysis Study

    ERIC Educational Resources Information Center

    Poppenk, Jordan; Norman, Kenneth A.

    2012-01-01

    Recent cognitive research has revealed better source memory performance for familiar relative to novel stimuli. Here we consider two possible explanations for this finding. The source memory advantage for familiar stimuli could arise because stimulus novelty induces attention to stimulus features at the expense of contextual processing, resulting…

  9. HIV gp120 H375 is unique to HIV-1 subtype CRF01_AE and confers strong resistance to the entry inhibitor BMS-599793, a candidate microbicide drug.

    PubMed

    Schader, Susan M; Colby-Germinario, Susan P; Quashie, Peter K; Oliveira, Maureen; Ibanescu, Ruxandra-Ilinca; Moisi, Daniela; Mespléde, Thibault; Wainberg, Mark A

    2012-08-01

    BMS-599793 is a small molecule entry inhibitor that binds to human immunodeficiency virus type 1 (HIV-1) gp120, resulting in the inhibition of CD4-dependent entry into cells. Since BMS-599793 is currently considered a candidate microbicide drug, we evaluated its efficacy against a number of primary patient HIV isolates from different subtypes and circulating recombinant forms (CRFs) and showed that activity varied between ∼3 ρM and 7 μM at 50% effective concentrations (EC(50)s). Interestingly, CRF01_AE HIV-1 isolates consistently demonstrated natural resistance against this compound. Genotypic analysis of >1,600 sequences (Los Alamos HIV sequence database) indicated that a single amino acid polymorphism in Env, H375, may account for the observed BMS-599793 resistance in CRF01_AE HIV-1. Results of site-directed mutagenesis experiments confirmed this hypothesis, and in silico drug docking simulations identified a drug resistance mechanism at the molecular level. In addition, CRF01_AE viruses were shown to be resistant to multiple broadly neutralizing monoclonal antibodies. Thus, our results not only provide insight into how Env polymorphisms may contribute to entry inhibitor resistance but also may help to elucidate how HIV can evade some broadly neutralizing antibodies. Furthermore, the high frequency of H375 in CRF01_AE HIV-1, and its apparent nonoccurrence in other subtypes, could serve as a means for rapid identification of CRF01_AE infections.

  10. Demonstration and development of control mechanism for radioactive sources in Saudi Arabia

    SciTech Connect

    Al-Kheliewi, A. S.

    2012-06-06

    Saudi Arabia have no nuclear industry. Nevertheless, many radioactive sources, for different purposes, have been used in the country. There is upswing in the number of companies that recruit nuclear technology in their daily work. The National Center for Radiation Protection (NCRP) takes the full commitment and responsibility for monitoring and regulating the movement of radioactive sources in the country. NCRP issues the licenses for import, export, and use of radioactive sources. It, also, protects the country from any trespassing radiation through a sizable net of early warning and radiation monitoring stations along the borders of Saudi Arabia. This paper talks about the procedures of licensing, importing, exporting of radioactive sources. It, also, sheds light on types of implementing radioactive sources in different practices encompass medicine, industry, research. The NCRP has established an electronic web site to ease the communication with all users in the country. This site is yet in the experimental stage.

  11. Observations of Herbig Ae/Be Stars with Herschel/PACS: The Atomic and Molecular Contents of Their Protoplanetary Discs

    NASA Technical Reports Server (NTRS)

    Meeus, G.; Montesinos, B.; Mendigutia, I.; Kamp, I.; Thi, W. F.; Eiroa, C.; Grady, C. A.; Mathews, G.; Sandell, G.; Martin-Zaidi, C.; Brittain, S.; Dent, W. R. F.; Howard, C.; Menard, F.; Pinte, C.; Roberge, A.; Vandenbussche, B.; Williams, J. P.

    2012-01-01

    We observed a sample of 20 representative Herbig Ae/Be stars and 5 A-type debris discs with PACS onboard Herschel, as part of the GAS in Protoplanetary Systems (GASPS) project. The observations were done in spectroscopic mode, and cover the far-infrared lines of [OI], [CII], CO, CH+, H20, and OH. We have a [OI]63 micro/ detection rate of 100% for the Herbig Ae/Be and 0% for the debris discs. The [OI] 145 micron line is only detected in 25% and CO J = 18-17 in 45% (and fewer cases for higher J transitions) of the Herbig Ae/Be stars, while for [CII] 157 micron, we often find spatially variable background contamination. We show the first detection of water in a Herbig Ae disc, HD 163296, which has a settled disc. Hydroxyl is detected as well in this disc. First seen in HD 100546, CH+ emission is now detected for the second time in a Herbig Ae star, HD 97048. We report fluxes for each line and use the observations as line diagnostics of the gas properties. Furthermore, we look for correlations between the strength of the emission lines and either the stellar or disc parameters, such as stellar luminosity, ultraviolet and X-ray flux. accretion rate, polycyclic aromatic hydrocarbon (PAH) band strength, and flaring. We find that the stellar ultraviolet flux is the dominant excitation mechanism of [OI] 63 micron, with the highest line fluxes being found in objects with a large amount of flaring and among the largest PAH strengths. Neither the amount of accretion nor the X-ray luminosity has an influence on the line strength. We find correlations between the line flux of [OI]63 micron and [OI] 145 micron, CO J = IS-17 and [OI] 6300 A, and between the continuum flux at 63 micron and at 1.3 mm, while we find weak correlations between the line flux. of [OI] 63 micron and the PAH luminosity, the line flux of CO J = 3-2, the continuum flux at 63 pm, the stellar effective temperature, and the Br-gamma luminosity. Finally, we use a combination of the [OI] 63 micron and C(12)O J

  12. Latitudinal variation of thermospheric hydrogen near solstice from AE-D observations

    NASA Technical Reports Server (NTRS)

    Sanatani, S.; Breig, E. L.

    1988-01-01

    Variations of thermospheric neutral atomic hydrogen with latitude during a solstice season near solar minimum were investigated using data acquired with the polar-orbiting AE-D satellite. Hydrogen concentrations at low latitude were found to be comparable to those found from observations with the AE-E satellite, but were slightly higher than concentrations derived from the 1983 mass spectrometer incoherent scatter atmospheric model. Results confirm the general summer-to-winter density increase, large latitudinal gradients in the summer hemisphere, and the winter enhancement of hydrogen observed in AE-C nighttime measurements. The AE-D data, however, show a small polar depression in hydrogen concentration at high winter latitudes, attributed to atmospheric dynamics following auroral heating. The density gradients observed by AE-D in the summer hemisphere were in sharp contrast to the more constant horizontal daytime profiles reported from OGO-6 and previous AE-C measurements, indicating the possibility of local time effects.

  13. Application of iron and zinc isotopes to track the sources and mechanisms of metal loading in a mountain watershed

    USGS Publications Warehouse

    Borrok, D.M.; Wanty, R.B.; Ian, Ridley W.; Lamothe, P.J.; Kimball, B.A.; Verplanck, P.L.; Runkel, R.L.

    2009-01-01

    Here the hydrogeochemical constraints of a tracer dilution study are combined with Fe and Zn isotopic measurements to pinpoint metal loading sources and attenuation mechanisms in an alpine watershed impacted by acid mine drainage. In the tested mountain catchment, ??56Fe and ??66Zn isotopic signatures of filtered stream water samples varied by ???3.5??? and 0.4???, respectively. The inherent differences in the aqueous geochemistry of Fe and Zn provided complimentary isotopic information. For example, variations in ??56Fe were linked to redox and precipitation reactions occurring in the stream, while changes in ??66Zn were indicative of conservative mixing of different Zn sources. Fen environments contributed distinctively light dissolved Fe (<-2.0???) and isotopically heavy suspended Fe precipitates to the watershed, while Zn from the fen was isotopically heavy (>+0.4???). Acidic drainage from mine wastes contributed heavier dissolved Fe (???+0.5???) and lighter Zn (???+0.2???) isotopes relative to the fen. Upwelling of Fe-rich groundwater near the mouth of the catchment was the major source of Fe (??56Fe ??? 0???) leaving the watershed in surface flow, while runoff from mining wastes was the major source of Zn. The results suggest that given a strong framework for interpretation, Fe and Zn isotopes are useful tools for identifying and tracking metal sources and attenuation mechanisms in mountain watersheds. ?? 2009 Elsevier Ltd.

  14. HIGH-RESOLUTION MID-INFRARED IMAGING OF THE CIRCUMSTELLAR DISKS OF HERBIG Ae/Be STARS

    SciTech Connect

    Marinas, N.; Telesco, C. M.; Packham, C.; Fisher, R. S.

    2011-08-20

    We have imaged the circumstellar environments of 17 Herbig Ae/Be stars at 12 and 18 {mu}m using MICHELLE on Gemini North and T-ReCS on Gemini South. Our sample contained eight Group I sources, those having large rising near- to far-infrared (IR) fluxes, and nine Group II sources, those having more modest mid-IR fluxes relative to their near-IR flux (in the classification of Meeus et al.). We have resolved extended emission from all Group I sources in our target list. The majority of these sources have radially symmetric mid-IR emission extending from a radius of 10 AU to hundreds of AU. Only one of the nine Group II sources is resolved at the FWHM level, with another two Group II sources resolved at fainter levels. Models by Dullemond et al. explain the observed spectral energy distribution of Group II sources using self-shadowed cold disks. If this is the case for all the Group II sources, we do not expect to detect extended emission with this study, since the IR emission measured should arise from a region only a few AU in size, which is smaller than our resolution. The fact that we do resolve some of the Group II sources implies that their disks are not completely flat, and might represent an intermediate stage. We also find that none of the more massive (>3 M{sub sun}) Herbig Ae/Be stars in our sample belongs to Group I, which may point to a relationship between stellar mass and circumstellar dust evolution. Disks around more massive stars might evolve faster so that stars are surrounded by a more evolved flat disk by the time they become optically visible, or they might follow a different evolutionary path altogether.

  15. NPS alternate techsat satellite, design project for AE-4871

    NASA Technical Reports Server (NTRS)

    1993-01-01

    This project was completed as part of AE-4871, Advanced Spacecraft Design. The intent of the course is to provide experience in the design of all the major components in a spacecraft system. Team members were given responsibility for the design of one of the six primary subsystems: power, structures, propulsion, attitude control, telemetry, tracking and control (TT&C), and thermal control. In addition, a single member worked on configuration control, launch vehicle integration, and a spacecraft test plan. Given an eleven week time constraint, a preliminary design of each subsystem was completed. Where possible, possible component selections were also made. Assistance for this project came principally from the Naval Research Laboratory's Spacecraft Technology Branch. Specific information on components was solicited from representatives in industry. The design project centers on a general purpose satellite bus that is currently being sought by the Strategic Defense Initiative.

  16. Report on the Development of the Advanced Encryption Standard (AES)

    PubMed Central

    Nechvatal, James; Barker, Elaine; Bassham, Lawrence; Burr, William; Dworkin, Morris; Foti, James; Roback, Edward

    2001-01-01

    In 1997, the National Institute of Standards and Technology (NIST) initiated a process to select a symmetric-key encryption algorithm to be used to protect sensitive (unclassified) Federal information in furtherance of NIST’s statutory responsibilities. In 1998, NIST announced the acceptance of 15 candidate algorithms and requested the assistance of the cryptographic research community in analyzing the candidates. This analysis included an initial examination of the security and efficiency characteristics for each algorithm. NIST reviewed the results of this preliminary research and selected MARS, RC™, Rijndael, Serpent and Twofish as finalists. Having reviewed further public analysis of the finalists, NIST has decided to propose Rijndael as the Advanced Encryption Standard (AES). The research results and rationale for this selection are documented in this report. PMID:27500035

  17. Coupling mechanism of interface-induced generation-recombination current with the floating source in nMOSFET

    NASA Astrophysics Data System (ADS)

    Chen, Haifeng; Xie, Duan; Guo, Lixin

    2016-11-01

    This paper presents a detailed investigation of the interface trap-induced generation-recombination current IGR in an n-type MOSFET. Under the positive drain bias VD-step-mode measurement, IGR demonstrates some abnormal changes and even transforms from the generation current to the recombination current. These phenomena ascribe to the coupling mechanism of IGR with the floating source. The core of this mechanism is that the floating source leads to the variable ΔEFN, which is the difference of the electron's quasi-Fermi levels between the source and the drain. The plus-minus sign of ΔEFN determines the function of the interface trap serving as the generation or recombination center, and the magnitude of ΔEFN determines the shape of IGR curve. Additionally, the area Ω of IGR curve is introduced to verify and quantitatively describe this coupling mechanism. It is found that Ω has the linear relationship with ΔEFN and the slope is 19 p/eV. This coupling mechanism provides a potential way to control the pA current based on the interface trap.

  18. Role of AE2 for pHi regulation in biliary epithelial cells

    PubMed Central

    Concepcion, Axel R.; Lopez, María; Ardura-Fabregat, Alberto; Medina, Juan F.

    2013-01-01

    The Cl−/HCO−3anion exchanger 2 (AE2) is known to be involved in intracellular pH (pHi) regulation and transepithelial acid-base transport. Early studies showed that AE2 gene expression is reduced in liver biopsies and blood mononuclear cells from patients with primary biliary cirrhosis (PBC), a disease characterized by chronic non-suppurative cholangitis associated with antimitochondrial antibodies (AMA) and other autoimmune phenomena. Microfluorimetric analysis of the Cl−/HCO−3 anion exchange (AE) in isolated cholangiocytes showed that the cAMP-stimulated AE activity is diminished in PBC compared to both healthy and diseased controls. More recently, it was found that miR-506 is upregulated in cholangiocytes of PBC patients and that AE2 may be a target of miR-506. Additional evidence for a pathogenic role of AE2 dysregulation in PBC was obtained with Ae2−/−a,b mice, which develop biochemical, histological, and immunologic alterations that resemble PBC (including development of serum AMA). Analysis of HCO−3 transport systems and pHi regulation in cholangiocytes from normal and Ae2−/−a,b mice confirmed that AE2 is the transporter responsible for the Cl−/HCO−3exchange in these cells. On the other hand, both Ae2+/+a,b and Ae2−/−a,b mouse cholangiocytes exhibited a Cl−-independent bicarbonate transport system, essentially a Na+-bicarbonate cotransport (NBC) system, which could contribute to pHi regulation in the absence of AE2. PMID:24478713

  19. OPTICAL MASS FLOW DIAGNOSTICS IN HERBIG AE/BE STARS

    SciTech Connect

    Cauley, P. Wilson; Johns-Krull, Christopher M. E-mail: cmj@rice.edu

    2015-09-01

    We examine a broad range of mass flow diagnostics in a large sample of Herbig Ae/Be stars (HAEBES) using high resolution optical spectra. The Hβ and He i 5876 Å lines show the highest incidence of P Cygni (30%) and inverse P Cygni (14%) morphologies, respectively. The Fe ii 4924 Å line also shows a large incidence of P Cygni profiles (11%). We find support for many of the conclusions reached in a study based on the analysis of the He i λ10830 line in a large sample of HAEBES. Namely, HAEBES exhibit smaller fractions of both blueshifted absorption (i.e., mass outflow) and redshifted absorption (i.e., mass infall or accretion) than their lower mass cousins, the classical T Tauri stars (CTTSs). In particular, the optical data supports the conclusion that HAEBES displaying redshifted absorption, in general, show maximum redshifted absorption velocities that are smaller fractions of their stellar escape velocities than is found for CTTSs. This suggests that HAEBE accretion flows are originating deeper in the gravitational potentials of their stars than in CTTS systems. In addition, we find a lack of inner disk wind signatures in the blueshifted absorption objects; only stellar wind signatures are clearly observed. These findings, along with the lack of detected magnetic fields around HAEBES, support the idea that large magnetospheres are not prevalent around HAEBES and that accretion flows are instead mediated by significantly smaller magnetospheres with relatively smaller truncation radii (e.g., 1–2 R{sub *}). Redshifted absorption is much more common around Herbig Ae stars than Be stars, suggesting that Herbig Be stars may accrete via a boundary layer rather than along magnetic field lines.

  20. Electrohydrodynamics of Charge Separation in Droplet-Based Ion Sources with Time-Varying Electrical and Mechanical Actuation

    PubMed Central

    Forbes, Thomas P.; Degertekin, F. Levent; Fedorov, Andrei G.

    2010-01-01

    Charge transport and separation in mechanically-driven, droplet-based ion sources are investigated using computational analysis and supporting experiments. A first-principles model of electrohydrodynamics (EHD) and charge migration is formulated and implemented using FLUENT CFD software for jet/droplet formation. For validation, classical experiments of electrospraying from a thin capillary are simulated, specifically, the transient EHD cone-jet formation of a fluid with finite electrical conductivity, and the Taylor cone formation in a perfectly electrically-conducting fluid. The model is also used to investigate the microscopic physics of droplet charging in mechanically-driven droplet-based ion sources, such as AMUSE (Array of Micromachined UltraSonic Electrospray). Here, AMUSE is subject to DC and AC electric fields of varying amplitude and phase, with respect to a time-varying mechanical force driving the droplet formation. For the DC-charging case, a linear relationship is demonstrated between the charge carried by each droplet and an applied electric field magnitude, in agreement with previously reported experiments. For the AC-charging case, a judiciously-chosen phase-shift in the time-varying mechanical (driving ejection) and electrical (driving charge transport) signals allows for a significantly increased amount of charge, of desired polarity, to be pumped into a droplet upon ejection. Complementary experimental measurements of electrospray electrical current and charge-per-droplet, produced by the AMUSE ion source, are performed and support theoretical predictions for both DC and AC-charging cases. The theoretical model and simulation tools provide a versatile and general analytical framework for fundamental investigations of coupled electrohydrodynamics and charge transport. The model also allows for the exploration of different configurations and operating modes to optimize charge separation in atmospheric pressure electrohydrodynamic ion sources

  1. Stomatin modulates the activity of the Anion Exchanger 1 (AE1, SLC4A1)

    PubMed Central

    Genetet, Sandrine; Desrames, Alexandra; Chouali, Youcef; Ripoche, Pierre; Lopez, Claude; Mouro-Chanteloup, Isabelle

    2017-01-01

    Anion Exchanger 1 (AE1) and stomatin are integral proteins of the red blood cell (RBC) membrane. Erythroid and kidney AE1 play a major role in HCO3− and Cl− exchange. Stomatins down-regulate the activity of many channels and transporters. Biochemical studies suggested an interaction of erythroid AE1 with stomatin. Moreover, we previously reported normal AE1 expression level in stomatin-deficient RBCs. Here, the ability of stomatin to modulate AE1-dependent Cl−/HCO3− exchange was evaluated using stopped-flow methods. In HEK293 cells expressing recombinant AE1 and stomatin, the permeabilities associated with AE1 activity were 30% higher in cells overexpressing stomatin, compared to cells with only endogenous stomatin expression. Ghosts from stomatin-deficient RBCs and controls were resealed in the presence of pH- or chloride-sensitive fluorescent probes and submitted to inward HCO3− and outward Cl− gradients. From alkalinization rate constants, we deduced a 47% decreased permeability to HCO3− for stomatin-deficient patients. Similarly, kinetics of Cl− efflux, followed by the probe dequenching, revealed a significant 42% decrease in patients. In situ Proximity Ligation Assays confirmed an interaction of AE1 with stomatin, in both HEK recombinant cells and RBCs. Here we show that stomatin modulates the transport activity of AE1 through a direct protein-protein interaction. PMID:28387307

  2. The optical counterpart of IRAS 12496 - 7650 - A highly embedded Herbig AE star

    NASA Astrophysics Data System (ADS)

    Hughes, J. D.; Hartigan, P.; Graham, J. A.; Emerson, J. P.; Marang, F.

    1991-03-01

    Optical and near-infrared observations of IRAS 12496 - 7650, an active young star and the most luminous IRAS source in the Chamaeleon II dark cloud, are reported. The object has become brighter at optical wavelengths since 1976, and has exhibited variations of more than a magnitude at K between January 1987 and May 1990. IRAS 12496 - 7650 is redder when fainter, and the amplitude of the brightness fluctuations decreases toward longer infrared wavelengths. Differing amounts of circumstellar extinction or intrinsic color variations of the source can produce most of the observed variability. Optical spectra confirm that IRAS 12496 - 7650 is an extremely active (probably Herbig Ae type) star with blueshifted forbidden lines of O I and S II and a prominent P-Cygni profile at H-alpha. The S II emission extends 3-4 arcsec on either side of the star and shows a significant velocity gradient, suggestive of a jetlike structure. The detection of outflowing material from IRAS 12496 - 7650 reinforces earlier evidence that this object is the exciting source for the HH 52 - 54 group Herbig-Haro objects. The broad spectral energy distribution suggests that IRAS 12496 - 7650 has a circumstellar disk.

  3. Source identification in acoustics and structural mechanics using Sierra/SD.

    SciTech Connect

    Walsh, Timothy Francis; Aquino, Wilkins; Ross, Michael

    2013-03-01

    In this report we derive both time and frequency-domain methods for inverse identification of sources in elastodynamics and acoustics. The inverse/design problem is cast in a PDE-constrained optimization framework with efficient computation of gradients using the adjoint method. The implementation of source inversion in Sierra/SD is described, and results from both time and frequency domain source inversion are compared to actual experimental data for a weapon store used in captive carry on a military aircraft. The inverse methodology is advantageous in that it provides a method for creating ground based acoustic and vibration tests that can reduce the actual number of flight tests, and thus, saving costs and time for the program.

  4. Sediment delivery to the Gulf of Alaska: source mechanisms along a glaciated transform margin

    USGS Publications Warehouse

    Dobson, M.R.; O'Leary, D.; Veart, M.

    1998-01-01

    Sediment delivery to the Gulf of Alaska occurs via four areally extensive deep-water fans, sourced from grounded tidewater glaciers. During periods of climatic cooling, glaciers cross a narrow shelf and discharge sediment down the continental slope. Because the coastal terrain is dominated by fjords and a narrow, high-relief Pacific watershed, deposition is dominated by channellized point-source fan accumulations, the volumes of which are primarily a function of climate. The sediment distribution is modified by a long-term tectonic translation of the Pacific plate to the north along the transform margin. As a result, the deep-water fans are gradually moved away from the climatically controlled point sources. Sets of abandoned channels record the effect of translation during the Plio-Pleistocene.

  5. Statistical studies of Pc 3-5 pulsations and their relevance for possible source mechanisms of ULF waves

    NASA Technical Reports Server (NTRS)

    Anderson, Brian J.

    1993-01-01

    A number of statistical studies using spacecraft data have been made of ULF waves in the magnetosphere. These studies provide an overview of ULF pulsation activity for r = 5-15 R(E) and allow an assessment of likely source mechanisms. In this review pulsations are categorized into five general types: compressional Pc 5, poloidal Pc 4, toroidal harmonics, toroidal Pc 5 (fundamental mode), and incoherent noise. The occurrence distributions and/or distributions of wave power of the different types suggest that compressional Pc 5 and poloidal Pc 4 derive their energy locally, most likely from energetic protons. The toroidal pulsations, both harmonic and fundamental mode, appear to be driven by an energy source outside the magnetopause - directly upstream in the sheath and solar wind for harmonics and the flanks for fundamentals. Incoherent pulsations are a prominent pulsation type but from their occurrence distribution alone it is unclear what their dominant energy source may be.

  6. Re-evaluation of focal depths and source mechanisms of selected earthquakes in the Afar depression

    NASA Astrophysics Data System (ADS)

    Hagos, L.; Shomali, H.; Roberts, R.

    2006-10-01

    We present a stepwise inversion procedure to assess the focal depth and model earthquake source complexity of seven moderate-sized earthquakes (6.2 >Mw > 5.1) that occurred in the Afar depression and the surrounding region. The Afar depression is a region of highly extended and intruded lithosphere, and zones of incipient seafloor spreading. A time-domain inversion of full moment tensor was performed to model direct P and SH waves of teleseismic data. Waveform inversion of the selected events estimated focal depths in the range of 17-22 km, deeper than previously published results. This suggests that the brittle-ductile transition zone beneath parts of the Afar depression extends more than 22 km. The effect of near-source velocity structure on the moment tensor elements was also investigated and was found to respond little to the models considered. Synthetic tests indicate that the size of the estimated, non-physical, non-isotropic source component is rather sensitive to incorrect depth estimation. The dominant double couple part of the moment tensor solutions for most of the events indicates that their occurrence is mainly due to shearing. Parameters associated with source directivity (rupture velocity and azimuth) were also investigated. Re-evaluation of the analysed events shows predominantly normal faulting consistent with the relative plate motions in the region.

  7. Lead sources to California sea otters: Industrial inputs circumvent natural lead biodepletion mechanisms

    SciTech Connect

    Smith, D.R.; Flegal, A.R. ); Niemeyer, S. )

    1992-04-01

    Lead levels (as Pb/Ca atom ratios) and stable isotopic compositions were measured in teeth of preindustrial and contemporary California sea otters (Enhydra lutris) to determine if postindustrial changes had occurred in the magnitude and source of accumulated lead. Lead/calcium atom ratios in teeth of some contemporary animals were significantly elevated and compared to level in other contemporary and preindustrial otters. The isotopic ratios revealed a change in the sources of accumulated leads, from natural continental-derived lead in the preindustrial animals ({sup 207}Pb/{sup 206}Pb = 0.820 {plus minus} 0.002) to industrial sources dominated by aerosol lead in the contemporary otters ({sup 207}Pb/{sup 206}Pb = 0.853), who contained lead derived from an industrial waste lead deposit in Monterey Harbor. These data establish distinguishable sources of lead assimilated by sea otters, and indicate that elevated exposures to some animals circumvented the natural biodepletion of lead through marine trophic pathways.

  8. Talker Identification across Source Mechanisms: Experiments with Laryngeal and Electrolarynx Speech

    ERIC Educational Resources Information Center

    Perrachione, Tyler K.; Stepp, Cara E.; Hillman, Robert E.; Wong, Patrick C. M.

    2014-01-01

    Purpose: The purpose of this study was to determine listeners' ability to learn talker identity from speech produced with an electrolarynx, explore source and filter differentiation in talker identification, and describe acoustic-phonetic changes associated with electrolarynx use. Method: Healthy adult control listeners learned to identify…

  9. Seismicity at White Island volcano, New Zealand: a revised classification and inferences about source mechanism

    NASA Astrophysics Data System (ADS)

    Sherburn, Steven; Scott, Bradley J.; Nishi, Yuji; Sugihara, Mituhiko

    1998-08-01

    The classification of earthquakes at White Island volcano, New Zealand, has been revised to address problems in existing classification schemes, to better reflect new data and to try to focus more on source processes. Seismicity generated by the direct involvement of magmatic or hydrothermal fluids are referred to as volcanic, and that generated by fault movement in response to stresses caused by those fluids, regional stresses, thermal effects and so on are referred to as volcano-tectonic. Spasmodic bursts form a separate category, as we have insufficient information to classify them as volcanic or volcano-tectonic. Volcanic seismicity is divided into short-duration, long-period volcanic earthquakes, long-duration volcanic earthquakes, and harmonic- and non-harmonic volcanic tremor, while volcano-tectonic seismicity is divided into shallow and deep volcano-tectonic earthquakes. Harmonic volcanic tremor is related to sub-surface intrusive processes, while non-harmonic volcanic tremor originates close to active craters at shallow depth, and usually occurs during eruptive activity. Short-duration, long-period volcanic earthquakes come from a single source close to the active craters, but originate deeper than non-harmonic volcanic tremor, and are not related to eruptive activity. Long-duration volcanic earthquakes often accompany larger discrete eruptions. The waveform of these events consists of an initial low-frequency part from a deep source, and a later cigar-shaped part of mixed frequencies from a shallow crater source.

  10. Structural and mutational analyses of Aes, an inhibitor of MalT in Escherichia coli.

    PubMed

    Schiefner, André; Gerber, Kinga; Brosig, Alexander; Boos, Winfried

    2014-02-01

    The acyl esterase Aes effectively inhibits the transcriptional activity of MalT-the central activator of maltose and maltodextrin utilizing genes in Escherichia coli. To provide better insight into the nature of the interaction between Aes and MalT, we determined two different crystal structures of Aes-in its native form and covalently modified by a phenylmethylsulfonyl moiety at its active site serine. Both structures show distinct space groups and were refined to a resolution of 1.8 Å and 2.3 Å, respectively. The overall structure of Aes resembles a canonical α/β-hydrolase fold, which is extended by a funnel-like cap structure that forms the substrate-binding site. The catalytic triad of Aes, comprising residues Ser165, His292, and Asp262, is located at the bottom of this funnel. Analysis of the crystal-packing contacts of the two different space groups as well as analytical size-exclusion chromatography revealed a homodimeric arrangement of Aes. The Aes dimer adopts an antiparallel contact involving both the hydrolase core and the cap, with its twofold axis perpendicular to the largest dimension of Aes. To identify the surface area of Aes that is responsible for the interaction with MalT, we performed a structure-based alanine-scanning mutagenesis to pinpoint Aes residues that are significantly impaired in MalT inhibition, but still exhibit wild-type expression and enzymatic activity. These residues map to a shallow slightly concave surface patch of Aes at the opposite site of the dimerization interface and indicate the surface area that interacts with MalT.

  11. High-resolution 25 μm Imaging of the Disks around Herbig Ae/Be Stars

    NASA Astrophysics Data System (ADS)

    Honda, M.; Maaskant, K.; Okamoto, Y. K.; Kataza, H.; Yamashita, T.; Miyata, T.; Sako, S.; Fujiyoshi, T.; Sakon, I.; Fujiwara, H.; Kamizuka, T.; Mulders, G. D.; Lopez-Rodriguez, E.; Packham, C.; Onaka, T.

    2015-05-01

    We imaged circumstellar disks around 22 Herbig Ae/Be stars at 25 μm using Subaru/COMICS and Gemini/T-ReCS. Our sample consists of an equal number of objects from each of the two categories defined by Meeus et al.; 11 group I (flaring disk) and II (flat disk) sources. We find that group I sources tend to show more extended emission than group II sources. Previous studies have shown that the continuous disk is difficult to resolve with 8 m class telescopes in the Q band due to the strong emission from the unresolved innermost region of the disk. This indicates that the resolved Q-band sources require a hole or gap in the disk material distribution to suppress the contribution from the innermost region of the disk. As many group I sources are resolved at 25 μm, we suggest that many, but not all, group I Herbig Ae/Be disks have a hole or gap and are (pre-)transitional disks. On the other hand, the unresolved nature of many group II sources at 25 μm supports the idea that group II disks have a continuous flat disk geometry. It has been inferred that group I disks may evolve into group II through the settling of dust grains into the mid-plane of the protoplanetary disk. However, considering the growing evidence for the presence of a hole or gap in the disk of group I sources, such an evolutionary scenario is unlikely. The difference between groups I and II may reflect different evolutionary pathways of protoplanetary disks. Based on data collected at the Subaru Telescope, via the time exchange program between Subaru and the Gemini Observatory. The Subaru Telescope is operated by the National Astronomical Observatory of Japan.

  12. HIGH-RESOLUTION 25 μM IMAGING OF THE DISKS AROUND HERBIG AE/BE STARS

    SciTech Connect

    Honda, M.; Maaskant, K.; Okamoto, Y. K.; Kataza, H.; Yamashita, T.; Miyata, T.; Sako, S.; Kamizuka, T.; Fujiyoshi, T.; Fujiwara, H.; Sakon, I.; Onaka, T.; Mulders, G. D.; Lopez-Rodriguez, E.; Packham, C.

    2015-05-10

    We imaged circumstellar disks around 22 Herbig Ae/Be stars at 25 μm using Subaru/COMICS and Gemini/T-ReCS. Our sample consists of an equal number of objects from each of the two categories defined by Meeus et al.; 11 group I (flaring disk) and II (flat disk) sources. We find that group I sources tend to show more extended emission than group II sources. Previous studies have shown that the continuous disk is difficult to resolve with 8 m class telescopes in the Q band due to the strong emission from the unresolved innermost region of the disk. This indicates that the resolved Q-band sources require a hole or gap in the disk material distribution to suppress the contribution from the innermost region of the disk. As many group I sources are resolved at 25 μm, we suggest that many, but not all, group I Herbig Ae/Be disks have a hole or gap and are (pre-)transitional disks. On the other hand, the unresolved nature of many group II sources at 25 μm supports the idea that group II disks have a continuous flat disk geometry. It has been inferred that group I disks may evolve into group II through the settling of dust grains into the mid-plane of the protoplanetary disk. However, considering the growing evidence for the presence of a hole or gap in the disk of group I sources, such an evolutionary scenario is unlikely. The difference between groups I and II may reflect different evolutionary pathways of protoplanetary disks.

  13. A mechanical-free 150-kHz repetition swept light source incorporated a KTN electro-optic deflector

    NASA Astrophysics Data System (ADS)

    Yagi, Shogo; Naganuma, Kazunori; Imai, Tadayuki; Shibata, Yasuo; Ishibashi, Shigeo; Sasaki, Yuzo; Sasaura, Masahiro; Fujiura, Kazuo; Kato, Kazutoshi

    2011-03-01

    We present a new light source for the swept-source OCT, that is, an external-cavity LD incorporating an electro-optic deflector. We use a KTN deflector that is unique in being very fast and simultaneously providing an appreciable deflection caused by injected carriers. Particularly, high-speed and nearly linear to the applied voltage operation is attained when KTN crystal is pre-charged. Our 1.3-μm Littman-Metcalf external-cavity laser exhibits static linewidth < 0.1 nm, and a 110-nm scanning range up to 150-kHz under a +/-200 V sinusoidal driving voltage to the deflector. Being free of mechanical resonance, the laser would hopefully realize a faster (in a separate study, deflector itself worked up to 400 kHz) and wavenumber-linear scan that is ideal for the swept-source OCT by designing the waveform of driving voltage. And as for the resolving power of deflector, while our KTN deflector has only 35 spatial resolvable points, the number of wavelength points for the swept source clearly exceeds to this limit, which we attribute to line narrowing effect accompanied by the laser operation. Preliminary OCT images taken using the swept source are also presented.

  14. Motionless electromagnetic phase stepping versus mechanical phase stepping in x-ray phase-contrast imaging with a compact source.

    PubMed

    Harmon, Katherine J; Miao, Houxun; Gomella, Andrew A; Bennett, Eric E; Foster, Barbara A; Bhandarkar, Priya; Wen, Han

    2015-04-21

    X-ray phase contrast imaging based on grating interferometers detects the refractive index distribution of an object without relying on radiation attenuation, thereby having the potential for reduced radiation absorption. These techniques belong to the broader category of optical wavefront measurement, which requires stepping the phase of the interference pattern to obtain a pixel-wise map of the phase distortion of the wavefront. While phase stepping traditionally involves mechanical scanning of a grating or mirror, we developed electromagnetic phase stepping (EPS) for imaging with compact sources to obviate the need for mechanical movement. In EPS a solenoid coil is placed outside the x-ray tube to shift its focal spot with a magnetic field, causing a relative movement between the projection of the sample and the interference pattern in the image. Here we present two embodiments of this method. We verified experimentally that electromagnetic and mechanical phase stepping give the same results and attain the same signal-to-noise ratios under the same radiation dose. We found that the relative changes of interference fringe visibility were within 3.0% when the x-ray focal spot was shifted by up to 1.0 mm in either direction. We conclude that when using x-ray tube sources, EPS is an effective means of phase stepping without the need for mechanical movement.

  15. Genetic instability in budding and fission yeast—sources and mechanisms

    PubMed Central

    Skoneczna, Adrianna; Kaniak, Aneta; Skoneczny, Marek

    2015-01-01

    Cells are constantly confronted with endogenous and exogenous factors that affect their genomes. Eons of evolution have allowed the cellular mechanisms responsible for preserving the genome to adjust for achieving contradictory objectives: to maintain the genome unchanged and to acquire mutations that allow adaptation to environmental changes. One evolutionary mechanism that has been refined for survival is genetic variation. In this review, we describe the mechanisms responsible for two biological processes: genome maintenance and mutation tolerance involved in generations of genetic variations in mitotic cells of both Saccharomyces cerevisiae and Schizosaccharomyces pombe. These processes encompass mechanisms that ensure the fidelity of replication, DNA lesion sensing and DNA damage response pathways, as well as mechanisms that ensure precision in chromosome segregation during cell division. We discuss various factors that may influence genome stability, such as cellular ploidy, the phase of the cell cycle, transcriptional activity of a particular region of DNA, the proficiency of DNA quality control systems, the metabolic stage of the cell and its respiratory potential, and finally potential exposure to endogenous or environmental stress. PMID:26109598

  16. Empirical tests of Zipf's law mechanism in open source Linux distribution.

    PubMed

    Maillart, T; Sornette, D; Spaeth, S; von Krogh, G

    2008-11-21

    Zipf's power law is a ubiquitous empirical regularity found in many systems, thought to result from proportional growth. Here, we establish empirically the usually assumed ingredients of stochastic growth models that have been previously conjectured to be at the origin of Zipf's law. We use exceptionally detailed data on the evolution of open source software projects in Linux distributions, which offer a remarkable example of a growing complex self-organizing adaptive system, exhibiting Zipf's law over four full decades.

  17. A test of a mechanical multi-impact shear-wave seismic source

    USGS Publications Warehouse

    Worley, David M.; Odum, Jack K.; Williams, Robert A.; Stephenson, William J.

    2001-01-01

    We modified two gasoline-engine-powered earth tampers, commonly used as compressional-(P) wave seismic energy sources for shallow reflection studies, for use as shear(S)-wave energy sources. This new configuration, termed ?Hacker? (horizontal Wacker?), is evaluated as an alternative to the manual sledgehammer typically used in conjunction with a large timber held down by the front wheels of a vehicle. The Hacker maximizes the use of existing equipment by a quick changeover of bolt-on accessories as opposed to the handling of a separate source, and is intended to improve the depth of penetration of S-wave data by stacking hundreds of impacts over a two to three minute period. Records were made with a variety of configurations involving up to two Hackers simultaneously then compared to a reference record made with a sledgehammer. Preliminary results indicate moderate success by the higher amplitude S-waves recorded with the Hacker as compared to the hammer method. False triggers generated by the backswing of the Hacker add unwanted noise and we are currently working to modify the device to eliminate this effect. Correlation noise caused by insufficient randomness of the Hacker impact sequence is also a significant noise problem that we hope to reduce by improving the coupling of the Hacker to the timber so that the operator has more control over the impact sequence.

  18. A mesoscale gravity wave event observed during CCOPE. III - Wave environment and probable source mechanisms

    NASA Technical Reports Server (NTRS)

    Koch, Steven E.; Dorian, Paul B.

    1988-01-01

    The multiscale environment of gravity wave events and the probable mechanisms of their origin are examined on the basis of observations taken during the Cooperative Convective Precipitation Experiment in extreme eastern Montana, during the period from 1200 UTC July 11, 1981, to 0500 UTC July 12. During this time, two distinct gravity wave episodes were diagnosed. The results of the analysis of the evolving structures in the subsynoptic-scale and mesoscale environments indicate that the observed mesoscale gravity waves were generated by geostrophic adjustment processes, with additional energy supplied through interaction with the critical level; their coherence was maintained through a ducting mechanism.

  19. Genetic effect of the Aegilops caudata plasmon on the manifestation of the Ae. cylindrica genome.

    PubMed

    Tsunewaki, Koichiro; Mori, Naoki; Takumi, Shigeo

    2014-01-01

    In the course of reconstructing Aegilops caudata from its own genome (CC) and its plasmon, which had passed half a century in common wheat (genome AABBDD), we produced alloplasmic Ae. cylindrica (genome CCDD) with the plasmon of Ae. caudata. This line, designated (caudata)-CCDD, was found to express male sterility in its second substitution backcross generation (SB2) of (caudata)-AABBCCDD pollinated three times with the Ae. cylindrica pollen. We repeatedly backcrossed these SB2 plants with the Ae. cylindrica pollen until the SB5 generation, and SB5F2 progeny were produced by self-pollination of the SB5 plants. Thirteen morphological and physiological characters, including pollen and seed fertilities, of the (caudata)-CCDD SB5F2 were compared with those of the euplasmic Ae. cylindrica. The results indicated that the male sterility expressed by (caudata)-CCDD was due to genetic incompatibility between the Ae. cylindrica genome and Ae. caudata plasmon that did not affect any other characters of Ae. cylindrica. Also, we report that the genome integrity functions in keeping the univalent transmission rate high.

  20. 15 CFR Appendix D to Part 30 - AES Filing Citation, Exemption and Exclusion Legends

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false AES Filing Citation, Exemption and Exclusion Legends D Appendix D to Part 30 Commerce and Foreign Trade Regulations Relating to Commerce and... Appendix D to Part 30—AES Filing Citation, Exemption and Exclusion Legends I. USML Proof of Filing...

  1. Draft Genome Sequence of Brevibacterium linens AE038-8, an Extremely Arsenic-Resistant Bacterium

    DOE PAGES

    Maizel, Daniela; Utturkar, Sagar M.; Brown, Steven D.; ...

    2015-04-16

    To understand the arsenic biogeocycles in the groundwaters at Tucumán, Argentina, we isolated Brevibacterium linens sp. strain AE38-8, obtained from arsenic-contaminated well water. This strain is extremely resistant to arsenicals and has arsenic resistance (ars) genes in its genome. Here, we report the draft genome sequence of B. linens AE38-8.

  2. Draft Genome Sequence of Brevibacterium linens AE038-8, an Extremely Arsenic-Resistant Bacterium.

    PubMed

    Maizel, Daniela; Utturkar, Sagar M; Brown, Steven D; Ferrero, Marcela A; Rosen, Barry P

    2015-04-16

    To understand the arsenic biogeocycles in the groundwaters at Tucumán, Argentina, we isolated Brevibacterium linens sp. strain AE38-8, obtained from arsenic-contaminated well water. This strain is extremely resistant to arsenicals and has arsenic resistance (ars) genes in its genome. Here, we report the draft genome sequence of B. linens AE38-8.

  3. Draft Genome Sequence of Brevibacterium linens AE038-8, an Extremely Arsenic-Resistant Bacterium

    PubMed Central

    Maizel, Daniela; Utturkar, Sagar M.; Brown, Steven D.; Ferrero, Marcela A.

    2015-01-01

    To understand the arsenic biogeocycles in the groundwaters at Tucumán, Argentina, we isolated Brevibacterium linens sp. strain AE38-8, obtained from arsenic-contaminated well water. This strain is extremely resistant to arsenicals and has arsenic resistance (ars) genes in its genome. Here, we report the draft genome sequence of B. linens AE38-8. PMID:25883298

  4. Characterization of an inducible amidase from Pseudomonas acidovorans AE1.

    PubMed

    Alt, J; Heymann, E; Krisch, K

    1975-05-06

    The main molecular and catalytic properties of an acetanilide-hydrolyzing enzyme from Pseudomonas acidovorans AE 1, purified to a homogeneous state, were investigated. The molecular weight was 57 500 as determined by gel filtration and 55 300 as computed from the amino acid composition. By polyacrylamide gel electrophoresis in dodecylsulfate a polypeptide chain weight of 56 700 was obtained. Based on the reaction of the highly purufied enzyme with diethyl-4-nitrophenyl phosphate an equivalent weight of approximately 59 100 was found. From these results it was concluded that the enzyme consists of a single polypeptide chain and contains one active site per molecule. The enzyme hydrolyzed esters as well as certain aromatic amides. It also catalysed the transfer of acetyl groups to phenetidine yielding phenacetin. The activities towards aliphatic esters were much smaller. The enzyme was stable at pH values ranging from 7 to 9 and its pH-optimum was about 10. It was strongly inhibited by organophosphorous compounds, like diethyl-4-nitrophenyl phosphate or diisopropylphosphorofluoridate, as well as by physostigmine sulfate and -SH-blocking reagents, like HgCl-2 or 4-chloromercuribenzoic acid. o-Nitrophenol caused a competitive inhibition and phenetidine an uncompetitive inhibition.

  5. The (BETA) Pictoris Phenomenon Among Herbig Ae/Be Stars

    NASA Technical Reports Server (NTRS)

    Grady, C. A.; Perez, M. R.; Talavera, A.; Bjorkman, K. S.; deWinter, D.; The, P.-S.; Molster, F. J.; vandenAncker, M. E.; Sitko, M. L.; Morrison, N. D.; Beaver, M. L.; McCollum, B.; Castelaz, M. W.

    1996-01-01

    We present a survey of high dispersion UV and optical spectra of Herbig Ae/Be (HAeBe) and related stars. We find accreting, circumstellar gas over the velocity range +100 to +400 km/s, and absorption profiles similar to those seen toward Beta Pic, in 36% of the 33 HAeBe stars with IUE data as well as in 3 non-emission B stars. We also find evidence of accretion in 7 HAeBe stars with optical data only. Line profile variability appears ubiquitous. As a group, the stars with accreting gas signatures have higher v sin i than the stars with outflowing material, and tend to exhibit large amplitude (greater than or equal to 1(sup m)) optical light variations. All of the program stars with polarimetric variations that are anti-correlated with the optical light, previously interpreted as the signature of a dust disk viewed close to equator-on, also show spectral signatures of accreting gas. These data imply that accretion activity in HAeBe stars is preferentially observed when the line of sight transits the circumstellar dust disk. Our data imply that the spectroscopic signatures of accreting circumstellar material seen in Beta Pic are not unique to that object, but instead are consistent with interpretation of Beta Pic as a comparatively young A star with its associated circumstellar disk.

  6. The antiangiogenic agent Neovastat (AE-941) induces endothelial cell apoptosis.

    PubMed

    Boivin, Dominique; Gendron, Sébastien; Beaulieu, Edith; Gingras, Denis; Béliveau, Richard

    2002-08-01

    Neovastat (AE-941), a naturally occurring multifunctional antiangiogenic agent, has been shown to inhibit key components of the angiogenic process, including matrix metalloproteinases and vascular endothelial growth factor-mediated signaling events. In this study, we report the presence of a proapoptotic activity within this compound. Neovastat treatment of bovine aortic endothelial cells caused cell death with characteristics of apoptosis, including chromatin condensation and DNA fragmentation. Neovastat markedly induced caspase-3, caspase-8, and caspase-9 activities, at similar levels to those measured in cells treated with tumor necrosis factor-alpha. Activation of caspases by Neovastat appears to be essential for its proapoptotic effects because all apoptotic features were blocked by zVAD-fmk, a broad-spectrum caspase inhibitor. The activation of caspases was correlated with the cleavage of the nuclear substrate poly(ADP-ribose) polymerase, and by a concomitant release of cytochrome c from mitochondria to the cytoplasm. Neovastat-induced apoptosis appears to be specific to endothelial cells because treatment of other cell types such as U-87, COS-7, NIH-3T3, and SW1353 did not result in increased caspase-3 activity. These results demonstrate that Neovastat contains a proapoptotic factor that specifically induces the activation of caspases in endothelial cells and the resulting apoptosis of these cells.

  7. On the location of the oscillations in AE Aquarii

    NASA Technical Reports Server (NTRS)

    Welsh, William F.; Horne, Keith; Gomer, Richard

    1993-01-01

    There is much recent interest on the nature of the oscillations in the cataclysmic variable AE Aquarii. Detected in the optical, UV, X-ray, and possibly gamma-ray bands, the origin of these 33-sec oscillations remains poorly understood; the oscillation time-delay curve is phase shifted by about 60 deg with respect to the emission-line radial velocity curve, although both should track the orbital motion of the white dwarf. We present simultaneous absorption and emission-line radial velocities, and from the absorption lines we derive an improved ephemeris. Our emission-line velocities are phase shifted by about 75 deg, and hence are unreliable tracers of the orbital motion of the white dwarf. However, the oscillation orbit is shifted by only 5 deg +/- 3 deg percent confirming that the oscillations arise from a region concentric with the white dwarf. Thus the arrival times of the oscillations yield a measure of the white dwarfs apparent orbital velocity, independent of emission-line radial velocity measurements.

  8. The cause of high-intensity long-duration continuous AE activity (HILDCAAS) - Interplanetary Alfven wave trains

    NASA Technical Reports Server (NTRS)

    Tsurutani, Bruce T.; Gonzalez, Walter D.

    1987-01-01

    It is shown that high intensity (AE of greater than 1,000 nT), long duration (T of greater than 2d) continuous auroral activity events are caused by outward (from the sun) propagating interplanetary Alfven wave trains. The Alfven waves are often (but not always) detected several days after major interplanetary events, such as shocks and solar wind density enhancements. Presumably, magnetic reconnection between the southward components of the Alfven wave magnetic fields and magnetospheric fields is the mechanism for transfer of solar wind energy to the magnetosphere.

  9. Earthquake source mechanisms from body-waveform inversion and intraplate tectonics in the northern Indian Ocean

    NASA Technical Reports Server (NTRS)

    Bergman, E. A.; Solomon, S. C.

    1985-01-01

    Double-couple point-source parameters for 11 of the largest intraplate earthquakes in the northern Indian Ocean during the last 20 years were determined from a formal inversion of the long-period P and SH waveforms. Two major intraplate tectonic provinces are distinguished in the northern Indian Ocean. The plate-wide stress pattern found and the high level of intraplate seismicity are probably the results of substantial resistance, along the Himalayan continental collision zone, to the continued northward motion of the western portion of the Indian plate.

  10. Proanthocyanidins Extracted from Rhododendron pulchrum Leaves as Source of Tyrosinase Inhibitors: Structure, Activity, and Mechanism

    PubMed Central

    Chai, Wei-Ming; Wang, Rui; Wei, Man-Kun; Zou, Zheng-Rong; Deng, Rong-Gen; Liu, Wei-Sheng; Peng, Yi-Yuan

    2015-01-01

    The objective of this study was to assess the structure, anti-tyrosinase activity, and mechanism of proanthocyanidins extracted from Rhododendron pulchrum leaves. Results obtained from mass spectra of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and high performance liquid chromatography electrospray ionization mass spectrometry (HPLC-ESI-MS) revealed that proanthocyanidins were complex mixtures of procyanidins, prodelphinidins, propelargonidins, and their derivatives, among which procyanidins were the main components. The anti-tyrosinase analysis results indicated that the mixtures were reversible and mixed competitive inhibitors of tyrosinase. Interactions between proanthocyanidins with substrate (L-tyrosine and 3,4-dihydroxyphenylalanine) and with copper ions were the important molecular mechanisms for explaining their efficient inhibition. This research would provide scientific evidence for the use of R. pulchrum leaf proanthocyanidins as new novel tyrosinase inhibitors. PMID:26713623

  11. A Dynamic Damage Mechanics Source Model for Explosions in Crystalline Rock

    NASA Astrophysics Data System (ADS)

    Mihaly, J. M.; Bhat, H. S.; Sammis, C. G.; Rosakis, A.

    2011-12-01

    The micromechanical damage mechanics formulated by Ashby and Sammis [PAGEOPH, 1990] and generalized by Deshpande and Evans [J. Mech. Phys. Solids, 2008] has been extended to allow for a more generalized stress state and to incorporate an experimentally motivated crack growth (damage evolution) law that is valid over a wide range of loading rates. This law is sensitive to both the crack tip stress field and its time derivative, and thus produces strain-rate sensitivity in the constitutive response. The model is experimentally verified by predicting the failure strength of Dionysus-Pentelicon marble over strain rates ranging from to . This rate-dependent damage mechanics has been implemented in the ABAQUS dynamic finite element code and used to explore the effects of burn rate (loading rate) and lithostatic stress on the spatial extent of fracture damage and S waves generated by explosions in crystalline rock. Slower rise times and longer pressure pulses produce more damage and stronger S waves.

  12. Mechanical Properties of Porous, High Temperature Structural Materials: Sources of Toughness in Reaction Bonded Silicon Nitride.

    DTIC Science & Technology

    1995-10-15

    AND ADDRESS(ES) Air Force Office of Scientific Research Directorate of Aerospace Sciences Bolling Air Force Base, DC 20332-6448 Attention: Dr. Walter F...Jones 11. SUPPLEMENTARY NOTESFinal Technical Report of Experimental and Modeling Research Conducted under AFOSR Support over the period 1/5/1991-31...Associated with the Research Program 1. A.S. Argon, Principal Investigator, Quentin Berg Professor of Mechanical Engineering. 2. J.S. Haggerty, Co

  13. Cell Source and Mechanism of Hair Cell Regeneration in the Neonatal Mouse Cochlea

    DTIC Science & Technology

    2015-09-30

    mechanism of hair cell regeneration in the neonatal mouse cochlea. Non-mammalian vertebrates such as birds , fish , and amphibians can regenerate hair...cells, and inner phalangeal cells (Figure 4). There are also cells medial to inner phalangeal cells called the greater epithelial ridge (GER) which...tetracycline-inducible mouse line ( called Atohl-rtTA) using the Atohl enhancer to drive expression of the reverse tetracycline transactivator (rtTA

  14. Aftershock source mechanisms from the June 9, 1994, Deep Bolivian Earthquake

    NASA Astrophysics Data System (ADS)

    Tinker, Mark Andrew; Wallace, Terry C.; Beck, Susan L.; Silver, Paul G.; Zandt, George

    The Mw 8.3 Bolivia earthquake occurred on June 9, 1994, at a depth of 636 km. This is the largest deep event in recorded history and ruptured a portion of the down-going Nazca slab unknown to have ruptured previously. We recorded the main shock and aftershocks on the BANJO and SEDA portable, broadband seismic arrays deployed in Bolivia during this event. Myers et al. (this issue) identified and located 36 aftershocks (M>2) for the 10-day period following the main shock. We use a grid search technique to determine focal mechanisms for 12 of these aftershocks ranging in magnitude from 2.7 to 5.3. We compare the observed P to SV and SH ratios to a series of synthetics that represent different fault plane orientations. We find consistent focal mechanisms with the T-axis roughly horizontal and oriented approximately east-west, and the P-axis predominantly vertical. The aftershock focal mechanisms indicate a rotation of the P-axis within the slab from down-dip compression prior to the main shock to a near-vertical direction afterwards. This observation is consistent with the release of shear stress on the near-horizontal rupture plane and the subsequent rotation of the maximum compressive stress to a fault -normal orientation.

  15. Wear Mechanisms in Electron Sources for Ion Propulsion, 2: Discharge Hollow Cathode

    NASA Technical Reports Server (NTRS)

    Mikellides, Ioannis G.; Katz, Ira; Goebel, Dan M.; Jameson, Kristina K.; Polk, James E.

    2008-01-01

    The wear of the keeper electrode in discharge hollow cathodes is a major impediment to the implementation of ion propulsion onboard long-duration space science missions. The development of a predictive theoretical model for hollow cathode keeper life has long been sought, but its realization has been hindered by the complexities associated with the physics of the partially ionized gas and the associated erosion mechanisms in these devices. Thus, although several wear mechanisms have been hypothesized, a quantitative explanation of life test erosion profiles has remained incomplete. A two-dimensional model of the partially ionized gas in a discharge cathode has been developed and applied to understand the mechanisms that drove the erosion of the keeper in two long-duration life tests of a 30-cm ion thruster. An extensive set of comparisons between predictions by the numerical simulations and measurements of the plasma properties and of the erosion patterns is presented. It is found that the near-plume plasma oscillations, predicted by theory and observed by experiment, effectively enhance the resistivity of the plasma as well as the energy of ions striking the keeper.

  16. Ionization mechanism of the ambient pressure pyroelectric ion source (APPIS) and its applications to chemical nerve agent detection.

    PubMed

    Neidholdt, Evan L; Beauchamp, J L

    2009-11-01

    We present studies of the ionization mechanism operative in the ambient pressure pyroelectric ionization source (APPIS), along with applications that include detection of simulants for chemical nerve agents. It is found that ionization by APPIS occurs in the gas-phase. As the crystal is thermally cycled over a narrow temperature range, electrical discharges near the surface of the crystal produce energetic species which, through reactions with atmospheric molecules, result in reactant ions such as protonated water clusters or clusters of hydroxide and water. Reactant ions can be observed directly in the mass spectrometer. These go on to react with trace neutrals via proton transfer reactions to produce the ions observed in mass spectra, which are usually singly protonated or deprotonated species. Further implicating gas-phase ionization, observed product distributions are highly dependent on the composition of ambient gases, especially the concentration of water vapor and oxygen surrounding the source. For example, basic species such as triethylamine are observed as singly protonated cations at a water partial pressure of 10 torr. At a water pressure of 4 torr, reactive oxygen species are formed and lead to observation of protonated amine oxides. The ability of the APPIS source to detect basic molecules with high proton affinities makes it highly suited for the detection of chemical nerve agents. We demonstrate this application using simulants corresponding to VX and GA (Tabun). With the present source configuration pyridine is detected readily at a concentration of 4 ppm, indicating ultimate sensitivity in the high ppb range.

  17. [Present status, mechanisms, and control techniques of nitrogen and phosphorus non-point source pollution from vegetable fields].

    PubMed

    Huang, Dong-Feng; Wang, Guo; Li, Wei-Hua; Qiu, Xiao-Xuan

    2009-04-01

    Chemical fertilizers are often excessively applied on vegetable fields to pursue higher yields. In some areas, the fertilization rates are several times of those needed by vegetables. Nitrogen and phosphorous are obviously accumulated in the vegetable soils, resulting in the malnutrition, excessive nitrate, and poor quality of vegetables. Furthermore, a series of environmental problems, e.g., deterioration of vegetable soil physical and chemical properties, nitrate pollution of groundwater, and eutrophication of surface water, are produced. This paper reviewed the present status of nitrogen and phosphorous non-point source pollution from vegetable soils (accumulation characteristics of nitrogen and phosphorous and their pollution risks to water environment and vegetables), pollution mechanisms (sources, transformation, and losses of nitrogen and phosphorous), and control techniques (fertilization, chemical addition, nitrogen catch crop cultivation, optimal planting system, spatial matching of source and sink landscapes, and grass buffer strip technology), aimed to supply references for the further study on the nitrogen and phosphorous non-point source pollution from vegetable fields.

  18. Connecting Organic Aerosol Climate-Relevant Properties to Chemical Mechanisms of Sources and Processing

    SciTech Connect

    Thornton, Joel

    2015-01-26

    The research conducted on this project aimed to improve our understanding of secondary organic aerosol (SOA) formation in the atmosphere, and how the properties of the SOA impact climate through its size, phase state, and optical properties. The goal of this project was to demonstrate that the use of molecular composition information to mechanistically connect source apportionment and climate properties can improve the physical basis for simulation of SOA formation and properties in climate models. The research involved developing and improving methods to provide online measurements of the molecular composition of SOA under atmospherically relevant conditions and to apply this technology to controlled simulation chamber experiments and field measurements. The science we have completed with the methodology will impact the simulation of aerosol particles in climate models.

  19. Source Mechanism, Stress Triggering, and Hazard Analysis of Induced Seismicity in Oil/Gas Fields in Oman and Kuwait

    NASA Astrophysics Data System (ADS)

    Gu, C.; Toksoz, M. N.; Ding, M.; Al-Enezi, A.; Al-Jeri, F.; Meng, C.

    2015-12-01

    Induced seismicity has drawn new attentions in both academia and industry in recent years as the increasing seismic activity in the regions of oil/gas fields due to fluid injection/extraction and hydraulic fracturing. Source mechanism and triggering stress of these induced earthquakes are of great importance for understanding their causes and the physics of the seismic processes in reservoirs. Previous research on the analysis of induced seismic events in conventional oil/gas fields assumed a double couple (DC) source mechanism. The induced seismic data in this study are from both Oman and Kuwait. For the Oman data, the induced seismicity is monitored by both surface network (0source mechanisms and triggering stress. We determine the full moment tensor of the induced seismicity data, based on a full-waveform inversion method (Song and Toksöz, 2011). With the full moment tensor inversion results, Coulomb stress is calculated to investigate the triggering features of the induced seismicity data. Our results show a detailed evolution of 3D triggering stress in oil/gas fields from year 1999 to 2007 for Oman, and from year 2006 to 2015 for Kuwait. In addition, the local hazard corresponding to the induced seismicity in these oil/gas fields is assessed and compared to ground motion prediction due to large (M>5.0) regional tectonic earthquakes.

  20. Inferring source regions and supply mechanisms of iron in the Southern Ocean from satellite data

    NASA Astrophysics Data System (ADS)

    Graham, Robert M.; de Boer, Agatha M.; van Sebille, Erik; kohfeld, Karen E.; Schlosser, Christian

    2016-04-01

    In many biogeochemical models a large shelf sediment iron flux is prescribed through the seafloor over all areas of bathymetry shallower than 1000 m. Here we infer the likely location of shelf sediment iron sources by identifying where mean annual satellite chlorophyll concentrations are enhanced over shallow bathymetry ( > 1000 m). We show that mean annual chlorophyll concentrations are not visibly enhanced over areas of shallow bathymetry located more than 500 km from a coastline. Chlorophyll concentrations > 2 mg m-3 are only found within 50 km of a continental or island coastline. These results suggest that large sedimentary iron fluxes only exist on continental or island shelves. Large sedimentary iron fluxes are unlikely to be found on isolated seamounts and submerged plateaus. We further compare satellite chlorophyll concentrations to the position of ocean fronts to assess the relative role of horizontal advection and upwelling for supplying iron to the ocean surface. Sharp gradients in chlorophyll concentrations are observed across western boundary currents. Large chlorophyll blooms develop where western boundary currents detach from the continental shelves and turn eastwards into the Southern Ocean. Chlorophyll concentrations are enhanced along contours of sea surface height extending off continental and island shelves. These observations support the hypothesis that bioavailable iron from continental shelves is entrained into western boundary currents and advected into the Sub-Antarctic Zone along the Dynamical Subtropical Front. Likewise, iron from island shelves is entrained into nearby fronts and advected downstream. Mean annual chlorophyll concentrations are very low in open ocean regions with large modelled upwelling velocities, where fronts cross over topographic ridges. These results suggests that open ocean upwelling is unlikely to deliver iron to the surface from deep sources such as hydrothermal vents.

  1. Volcanic Source Mechanisms from the Low Frequency End of Broadband Recordings: Examples from Fuego Volcano

    NASA Astrophysics Data System (ADS)

    Waite, G. P.; Brill, K. A.

    2014-12-01

    With the proliferation of broadband recordings from volcanoes, it has become clear that conduit processes produce seismic signals with an extensive range of frequencies. Near the low corner of broadband instruments, the affects of ground rotation can be significant; rotation dominates at periods below the corner. Unraveling the relative influence of translation and rotation on recordings of very-long-period (12 - 120 s) and ultra-long-period (120-600 s) events is an important challenge, because including tilt in inversion of VLP and ULP signals associated with small eruptions can provide constraints on the dynamics of conduit processes. At Fuego volcano in Guatemala, we recorded hundreds of small-scale explosions in field campaigns since 2008 using temporary arrays of seismometers, tiltmeters and microbarometers. Explosions are frequently preceded by 5 to 20 minutes of tilt, indicative of pressurization of the upper conduit. The onset of explosive eruptions, which last from many tens of seconds to more than two minutes, include VLPs with peak periods from less than 30 to nearly 50 seconds. The events are dominated by ash emission that suggests a vulcanian-style downward migration of the magma fragmentation front. Joint inversions of the seismic and tilt signals using synthetic tilt and displacement Green functions provides a more complete view of the eruption process at Fuego. Inversions without tilt point to a source centroid 200 m west of and 300 m below the vent. When lower frequencies are included in the inversion, the source centroid shallows and moves east to a position directly below the vent. We interpret this to reflect a process where the vent seals and pressurizes, producing the ULP signal. The VLP signal results from a rapid change in the deformation of the upper few hundred meters of the conduit due to the ejection of magma during the explosion.

  2. Microfabricated microengine for use as a mechanical drive and power source in the microdomain and fabrication process

    SciTech Connect

    Garcia, E.J.; Sniegowski, J.J.

    1994-12-31

    A microengine uses two synchronized linear actuators as a power source and converts oscillatory motion from the actuators into rotational motion via direct linkage connection to an output gear or wheel. The microengine provides output in the form of a continuously rotating output gear that is capable of delivering drive torque to a micromechanism. The microengine can be operated at varying speeds and its motion can be reversed. Linear actuators are synchronized in order to provide linear oscillatory motion to the linkage means in the X and Y directions according to a desired position, rotational direction and speed of said mechanical output means. The output gear has gear teeth on its outer perimeter for directly contacting a micromechanism requiring mechanical power. The gear is retained by a retaining means which allows said gear to rotate freely. The microengine is microfabricated of polysilicon on one wafer using surface micromachining batch fabrication.

  3. Microfabricated microengine for use as a mechanical drive and power source in the microdomain and fabrication process

    DOEpatents

    Garcia, E.J.; Sniegowski, J.J.

    1997-05-20

    A microengine uses two synchronized linear actuators as a power source and converts oscillatory motion from the actuators into rotational motion via direct linkage connection to an output gear or wheel. The microengine provides output in the form of a continuously rotating output gear that is capable of delivering drive torque to a micromechanism. The microengine can be operated at varying speeds and its motion can be reversed. Linear actuators are synchronized in order to provide linear oscillatory motion to the linkage means in the X and Y directions according to a desired position, rotational direction and speed of said mechanical output means. The output gear has gear teeth on its outer perimeter for directly contacting a micromechanism requiring mechanical power. The gear is retained by a retaining means which allows said gear to rotate freely. The microengine is microfabricated of polysilicon on one wafer using surface micromachining batch fabrication. 30 figs.

  4. Microfabricated microengine for use as a mechanical drive and power source in the microdomain and fabrication process

    DOEpatents

    Garcia, Ernest J.; Sniegowski, Jeffry J.

    1997-01-01

    A microengine uses two synchronized linear actuators as a power source and converts oscillatory motion from the actuators into rotational motion via direct linkage connection to an output gear or wheel. The microengine provides output in the form of a continuously rotating output gear that is capable of delivering drive torque to a micromechanism. The microengine can be operated at varying speeds and its motion can be reversed. Linear actuators are synchronized in order to provide linear oscillatory motion to the linkage means in the X and Y directions according to a desired position, rotational direction and speed of said mechanical output means. The output gear has gear teeth on its outer perimeter for directly contacting a micromechanism requiring mechanical power. The gear is retained by a retaining means which allows said gear to rotate freely. The microengine is microfabricated of polysilicon on one wafer using surface micromachining batch fabrication.

  5. Phylodynamic analysis of the dissemination of HIV-1 CRF01_AE in Vietnam.

    PubMed

    Liao, Huanan; Tee, Kok Keng; Hase, Saiki; Uenishi, Rie; Li, Xiao-Jie; Kusagawa, Shigeru; Thang, Pham Hong; Hien, Nguyen Tran; Pybus, Oliver G; Takebe, Yutaka

    2009-08-15

    To estimate the epidemic history of HIV-1 CRF01_AE in Vietnam and adjacent Guangxi, China, we determined near full-length nucleotide sequences of CRF01_AE from a total of 33 specimens collected in 1997-1998 from different geographic regions and risk populations in Vietnam. Phylogenetic and Bayesian molecular clock analyses were performed to estimate the date of origin of CRF01_AE lineages. Our study reconstructs the timescale of CRF01_AE expansion in Vietnam and neighboring regions and suggests that the series of CRF01_AE epidemics in Vietnam arose by the sequential introduction of founder strains into new locations and risk groups. CRF01_AE appears to have been present among heterosexuals in South-Vietnam for more than a decade prior to its epidemic spread in the early 1990s. In the late 1980s, the virus spread to IDUs in Southern Vietnam and subsequently in the mid-1990s to IDUs further north. Our results indicate the northward dissemination of CRF01_AE during this time.

  6. Mechanisms and sources of radon entry in buildings constructed with modern technologies.

    PubMed

    Zhukovsky, M V; Vasilyev, A V

    2014-07-01

    To investigate the influence of modern building construction technologies on the accumulation of radon indoor, 20 rooms in buildings constructed using mostly monolithic concrete or aerated concrete blocks have been studied. Dominance of the diffusion mechanism of radon entry in buildings constructed with modern technologies has been established. As a result of computer simulations it was found that the main contribution to the variability of radon concentration was made by changes in the ventilation rate. At a low ventilation rate (<0.2 h(-1)) radon concentration above 200 Bq m(-3) can be observed for residential buildings. There is a need for the regulation of the radium-specific activity in building materials. According to the estimates of this study, the content of 226Ra in building materials should not exceed the value of 100 Bq kg(-1).

  7. Beach tar accumulation, transport mechanisms, and sources of variability at Coal Oil Point, California.

    PubMed

    Del Sontro, Tonya S; Leifer, Ira; Luyendyk, Bruce P; Broitman, Bernardo R

    2007-09-01

    A new field method for tar quantification was used at Coal Oil Point (COP), California to study the mechanisms transporting oil/tar from the nearby COP natural marine hydrocarbon seep field. This method segregates tar pieces into six size classes and assigns them an average mass based on laboratory or direct field measurements. Tar accumulation on the 19,927m(2) survey area was well resolved spatially by recording tar mass along twelve transects segmented into 4-m(2) blocks and then integrating over the survey area. A seasonal trend was apparent in total tar in which summer accumulations were an order of magnitude higher than winter accumulations. Based on multiple regression analyses between environmental data and tar accumulation, 34% of tar variability is explained by a combination of onshore advection via wind and low swell height inhibiting slick dispersion.

  8. Comparison of nanocrystalline material produced using mechanical milling and a RF-plasma heating source

    SciTech Connect

    Breitbach, K.L.; Chumbley, L.S. )

    1991-11-01

    This paper reports on nanocrystals which are polycrystalline materials with a grain size on the order of one to ten nanometers and appear to be a new class of materials with interesting properties and characteristics. Since the grain size of these materials is so small, a large percentage of their atoms are located in the interfaces; thus, the material can be thought of as a composite consisting of a crystalline component and a boundary component. The properties of these materials are, therefore, expected to be dependent upon the relative amounts of these two components. A study has been initiated to produce nanocrystalline Cr{sub 3}Si and Ti{sub 5}Si{sub 3} material. It has been shown that by reducing the grain size to the nanometer scale, the ductility of brittle compounds increases, due presumably to the increase in the percentage of the boundary component. Thus, these materials were examined as models of how hard, brittle, high temperature intermetallic compounds may behave in the nanocrystalline state. The silicide compounds also are being studied since they have excellent properties such as low densities, high melting temperatures, good corrosion resistance at low temperatures and fairly good oxidation resistance at high temperatures. It is hoped that with this combination of characteristics, plus increased ductility due to the small grain size, these materials will find practical industrial applications. The nanocrystalline material studied was produced using mechanical milling techniques and an inductively coupled plasma (ICP) system. Mechanical milling was chosen since it has been demonstrated to be a convenient way to produce large quantities of nanocrystalline material. However, ball milling may produce a significant amount of contamination from the containment vessel and milling medium, the actual amount being dependent upon the specific method, length of milling time, container and medium used.

  9. Warm Eocene climate enhanced petroleum generation from Cretaceous source rocks: A potential climate feedback mechanism?

    NASA Astrophysics Data System (ADS)

    Kroeger, K. F.; Funnell, R. H.

    2012-02-01

    Earth surface temperatures, including in the deep sea increased by 5-10°C from the late Paleocene ca. 58 Myr ago to the Early Eocene Climatic Optimum (EECO) centered at about 51 Myr ago. A large (˜2.5‰) drop in δ13C of carbonate spans much of this interval. This suggests a long-term increase in the net flux of 13C-depleted carbon to the ocean and atmosphere that is difficult to explain by changes in surficial carbon cycling alone. We reveal a relationship between surface temperature increase and increased petroleum generation in sedimentary basins operating on 100 kyr to Myr time scales. We propose that early Eocene warming has led to a synchronization of periods of maximum petroleum generation and enhanced generation in otherwise unproductive basins through extension of the volume of source rock within the oil and gas window across hundreds of sedimentary basins globally. Modelling the thermal evolution of four sedimentary basins in the southwest Pacific predicted an up to 50% increase in petroleum generation that would have significantly increased leakage of light hydrocarbons and oil degeneration products into the atmosphere. Extrapolating our modelling results to hundreds of sedimentary basins worldwide suggests that globally increased leakage could have caused a climate feedback effect, driving or enhancing early Eocene climate warming.

  10. Effect of Coulomb collision on the negative ion extraction mechanism in negative ion sources

    SciTech Connect

    Goto, I. Nishioka, S.; Abe, S.; Hatayama, A.; Miyamoto, K.; Mattei, S.; Lettry, J.

    2016-02-15

    To improve the H{sup −} ion beam optics, it is necessary to understand the energy relaxation process of surface produced H{sup −} ions in the extraction region of Cs seeded H{sup −} ion sources. Coulomb collisions of charged particles have been introduced to the 2D3V-PIC (two dimension in real space and three dimension in velocity space particle-in-cell) model for the H{sup −} extraction by using the binary collision model. Due to Coulomb collision, the lower energy part of the ion energy distribution function of H{sup −} ions has been greatly increased. The mean kinetic energy of the surface produced H{sup −} ions has been reduced to 0.65 eV from 1.5 eV. It has been suggested that the beam optics of the extracted H{sup −} ion beam is strongly affected by the energy relaxation process due to Coulomb collision.

  11. Immortalization of human AE pre-leukemia cells by hTERT allows leukemic transformation

    PubMed Central

    Wunderlich, Mark; Chou, Fu-Sheng; Mulloy, James C.

    2016-01-01

    Human CD34+ hematopoietic stem and progenitor cells (HSPC) expressing fusion protein AML1-ETO (AE), generated by the t(8;21)(q22;q22) rearrangement, manifest enhanced self-renewal and dysregulated differentiation without leukemic transformation, representing a pre-leukemia stage. Enabling replicative immortalization via telomerase reactivation is a crucial step in cancer development. However, AE expression alone is not sufficient to maintain high telomerase activity to immortalize human HSPC cells, which may hamper transformation. Here, we investigated the cooperativity of telomerase reverse transcriptase (hTERT), the catalytic subunit of telomerase, and AE in disease progression. Enforced expression of hTERT immortalized human AE pre-leukemia cells in a telomere-lengthening independent manner, and improved the pre-leukemia stem cell function by enhancing cell proliferation and survival. AE-hTERT cells retained cytokine dependency and multi-lineage differentiation potential similar to parental AE clones. Over the short-term, AE-hTERT cells did not show features of stepwise transformation, with no leukemogenecity evident upon initial injection into immunodeficient mice. Strikingly, after extended culture, we observed full transformation of one AE-hTERT clone, which recapitulated the disease evolution process in patients and emphasizes the importance of acquiring cooperating mutations in t(8;21) AML leukemogenesis. In summary, achieving unlimited proliferative potential via hTERT activation, and thereby allowing for acquisition of additional mutations, is a critical link for transition from pre-leukemia to overt disease in human cells. AE-hTERT cells represent a tractable model to study cooperating genetic lesions important for t(8;21) AML disease progression. PMID:27509060

  12. Global temperature constraints on Aedes aegypti and Ae. albopictus persistence and competence for dengue virus transmission

    PubMed Central

    2014-01-01

    Background Dengue is a disease that has undergone significant expansion over the past hundred years. Understanding what factors limit the distribution of transmission can be used to predict current and future limits to further dengue expansion. While not the only factor, temperature plays an important role in defining these limits. Previous attempts to analyse the effect of temperature on the geographic distribution of dengue have not considered its dynamic intra-annual and diurnal change and its cumulative effects on mosquito and virus populations. Methods Here we expand an existing modelling framework with new temperature-based relationships to model an index proportional to the basic reproductive number of the dengue virus. This model framework is combined with high spatial and temporal resolution global temperature data to model the effects of temperature on Aedes aegypti and Ae. albopictus persistence and competence for dengue virus transmission. Results Our model predicted areas where temperature is not expected to permit transmission and/or Aedes persistence throughout the year. By reanalysing existing experimental data our analysis indicates that Ae. albopictus, often considered a minor vector of dengue, has comparable rates of virus dissemination to its primary vector, Ae. aegypti, and when the longer lifespan of Ae. albopictus is considered its competence for dengue virus transmission far exceeds that of Ae. aegypti. Conclusions These results can be used to analyse the effects of temperature and other contributing factors on the expansion of dengue or its Aedes vectors. Our finding that Ae. albopictus has a greater capacity for dengue transmission than Ae. aegypti is contrary to current explanations for the comparative rarity of dengue transmission in established Ae. albopictus populations. This suggests that the limited capacity of Ae. albopictus to transmit DENV is more dependent on its ecology than vector competence. The recommendations, which we

  13. Application of microwave plasma atomic emission spectrometry (MP-AES) for environmental monitoring of industrially contaminated sites in Hyderabad city.

    PubMed

    Kamala C T; Balaram V; Dharmendra V; Satyanarayanan M; Subramanyam K S V; Krishnaiah A

    2014-11-01

    Recently introduced microwave plasma-atomic emission spectroscopy (MP-AES) represents yet another and very important addition to the existing array of modern instrumental analytical techniques. In this study, an attempt is made to summarize the performance characteristics of MP-AES and its potential as an analytical tool for environmental studies with some practical examples from Patancheru and Uppal industrial sectors of Hyderabad city. A range of soil, sediment, water reference materials, particulate matter, and real-life samples were chosen to evaluate the performance of this new analytical technique. Analytical wavelengths were selected considering the interference effects of other concomitant elements present in different sample solutions. The detection limits for several elements were found to be in the range from 0.05 to 5 ng/g. The trace metals analyzed in both the sectors followed the topography with more pollution in the low-lying sites. The metal contents were found to be more in ground waters than surface waters. Since a decade, the pollutants are transfered from Patancheru industrial area to Musi River. After polluting Nakkavagu and turning huge tracts of agricultural lands barren besides making people residing along the rivulet impotent and sick, industrialists of Patancheru are shifting the effluents to downstream of Musi River through an 18-km pipeline from Patancheru. Since the effluent undergoes primary treatment at Common Effluent Treatment Plant (CETP) at Patanchru and travels through pipeline and mixes with sewage, the organic effluents will be diluted. But the inorganic pollutants such as heavy and toxic metals tend to accumulate in the environmental segments near and downstreams of Musi River. The data generated by MP-AES of toxic metals like Zn, Cu, and Cr in the ground and surface waters can only be attributed to pollution from Patancheru since no other sources are available to Musi River.

  14. Active phenomena in the pre-main sequence Herbig Ae star HD 163296

    NASA Technical Reports Server (NTRS)

    Catala, C.; Praderie, F.; Simon, T.; Talavera, A.; The, P. S.

    1989-01-01

    Observations by IUE of the short-term variability of the Mg II and Ca II resonance lines in the Herbig Ae star HD 163296 are presented. Evidence that these lines show a phenomenon of rotational modulation, similar to the one observed in AB Aur, another Herbig Ae star is found. The variations in the spectrum of HD 163296 are even more conspicuous than in the spectrum of AB Aur. Magnetically structured winds may thus be a widespread phenomenon among the pre-main sequence Herbig Ae/Be stars.

  15. Automated Estimating System (AES): Version 6.1: User`s manual. Revision 6

    SciTech Connect

    Schwarz, R.K.; Holder, D.A.

    1996-03-01

    This document describes Version 6.1 of the Automated Estimating System (AES), a personal computer-based software package. The AES is designed to aid in the creation, updating, and reporting of project cost estimates for the Estimating and Scheduling Engineering Department of Central Engineering Services of Lockheed Martin Energy Systems,Inc. AES provides formatted input screens to guide the user through the estimate creation/update process and provides several standardized reports that allow cost to be sorted and summarized in many different formats and at several levels of aggregation.

  16. Automated Estimating System (AES) version 6.0 - user`s manual. Revision 5

    SciTech Connect

    Holder, D.A.; Schwarz, R.K.

    1994-06-01

    This document describes Version 6.0 of the Automated Estimating System (AES), a personal computer-based software package. The AES is designed to aid in the creation, updating, and reporting of project cost estimates for the Estimating and Scheduling Engineering Department of Central Engineering Services of Martin Marietta Energy Systems, Inc. AES provides formatted input screens to guide the user through the estimate creation/update process and provides several standardized reports that allow cost to be sorted and summarized in many different formats and at several levels of aggregation.

  17. Application of TURBO-AE to Flutter Prediction: Aeroelastic Code Development

    NASA Technical Reports Server (NTRS)

    Hoyniak, Daniel; Simons, Todd A.; Stefko, George (Technical Monitor)

    2001-01-01

    The TURBO-AE program has been evaluated by comparing the obtained results to cascade rig data and to prediction made from various in-house programs. A high-speed fan cascade, a turbine cascade, a turbine cascade and a fan geometry that shower flutter in torsion mode were analyzed. The steady predictions for the high-speed fan cascade showed the TURBO-AE predictions to match in-house codes. However, the predictions did not match the measured blade surface data. Other researchers also reported similar disagreement with these data set. Unsteady runs for the fan configuration were not successful using TURBO-AE .

  18. Cross-correlation analysis of the AE index and the interplanetary magnetic field Bz component.

    NASA Technical Reports Server (NTRS)

    Meng, C.-I.; Tsurutani, B.; Kawasaki, K.; Akasofu, S.-I.

    1973-01-01

    A cross-correlation study between magnetospheric activity (the AE index) and the southward-directed component of the interplanetary magnetic field (IMF) is made for a total of 792 hours (33 days) with a time resolution of about 5.5 min. The peak correlation tends to occur when the interplanetary data are shifted approximately 40 min later with respect to the AE index data. Cross-correlation analysis is conducted on some idealized wave forms to illustrate that this delay between southward turning of the IMF and the AE index should not be interpreted as being the duration of the growth phase.

  19. An Open-Source Toolbox for Surrogate Modeling of Joint Contact Mechanics

    PubMed Central

    Eskinazi, Ilan

    2016-01-01

    Goal Incorporation of elastic joint contact models into simulations of human movement could facilitate studying the interactions between muscles, ligaments, and bones. Unfortunately, elastic joint contact models are often too expensive computationally to be used within iterative simulation frameworks. This limitation can be overcome by using fast and accurate surrogate contact models that fit or interpolate input-output data sampled from existing elastic contact models. However, construction of surrogate contact models remains an arduous task. The aim of this paper is to introduce an open-source program called Surrogate Contact Modeling Toolbox (SCMT) that facilitates surrogate contact model creation, evaluation, and use. Methods SCMT interacts with the third party software FEBio to perform elastic contact analyses of finite element models and uses Matlab to train neural networks that fit the input-output contact data. SCMT features sample point generation for multiple domains, automated sampling, sample point filtering, and surrogate model training and testing. Results An overview of the software is presented along with two example applications. The first example demonstrates creation of surrogate contact models of artificial tibiofemoral and patellofemoral joints and evaluates their computational speed and accuracy, while the second demonstrates the use of surrogate contact models in a forward dynamic simulation of an open-chain leg extension-flexion motion. Conclusion SCMT facilitates the creation of computationally fast and accurate surrogate contact models. Additionally, it serves as a bridge between FEBio and OpenSim musculoskeletal modeling software. Significance Researchers may now create and deploy surrogate models of elastic joint contact with minimal effort. PMID:26186761

  20. Ae2Sb2X4F2 (Ae = Sr, Ba): new members of the homologous series Ae2M(1+n)X(3+n)F2 designed from rock salt and fluorite 2D building blocks.

    PubMed

    Kabbour, Houria; Cario, Laurent

    2006-03-20

    We have designed new compounds within the homologous series Ae2F2M(1+n)X(3+n) (Ae = Sr, Ba; M = main group metal; n = integer) built up from the stacking of 2D building blocks of rock salt and fluorite types. By incrementally increasing the size of the rock salt 2D building blocks, we have obtained two new n = 1 members of this homologous series, namely, Sr2F2Sb2Se4 and Ba2F2Sb2Se4. We then succeeded in synthesizing these compounds using a high-temperature ceramic method. The structure refinements from the powder or single-crystal X-ray diffraction data confirmed presence of the expected alternating stacking of fluorite [Ae2F2] (Ae = Sr, Ba) and rock salt [Sb2Se4] 2D building blocks. However the Ba derivative shows a strong distortion of the [Sb2Se4] block and a concomitant change of the Sb atom coordination likely related to the lone-pair activity.

  1. Wear Mechanisms in Electron Sources for Ion Propulsion, 1: Neutralizer Hollow Cathode

    NASA Technical Reports Server (NTRS)

    Mikellides, Ioannis G.; Katz, Ira

    2008-01-01

    Upon the completion of two long-duration life tests of a 30-cm ion engine, the orifice channel of the neutralizer hollow cathode was eroded away to as much as twice its original diameter. Whereas the neutralizer cathode orifice opened significantly, no noticeable erosion of the discharge cathode orifice was observed. Noquantitative explanation of these erosion trends has been established since the completion of the two life tests. A two-dimensional model of the partially ionized gas inside these devices has been developed and applied to the neutralizer hollow cathode. The numerical simulations show that the main mechanism responsible for the channel erosion is sputtering by Xe+. These ions are accelerated by the sheath along the channel and bombard the surface with kinetic energy/charge of about 17 V at the beginning of cathode life. The density of the ions inside the neutralizer orifice is computed to be as high as 2.1 x 10(sup 22) m(sup -3). Because of the 3.5-times larger diameter of the discharge cathode orifice, the ion density inside the orifice is more than 40 times lower and the sheath drop 7 V lower compared with the values in the neutralizer. At these conditions, Xe+ can cause no significant sputtering of the surface.

  2. Avocado Proanthocyanidins as a Source of Tyrosinase Inhibitors: Structure Characterization, Inhibitory Activity, and Mechanism.

    PubMed

    Chai, Wei-Ming; Wei, Man-Kun; Wang, Rui; Deng, Rong-Gen; Zou, Zheng-Rong; Peng, Yi-Yuan

    2015-08-26

    Proanthocyanidins were purified from avocado (Persea americana) fruit, and their structures were analyzed by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) and high-performance liquid chromatography-electrospray ionization-QTRAP mass spectrometry (HPLC-ESI-QTRAP MS) techniques. The results obtained from mass spectrometry (MS) analysis demonstrated that the proanthocyanidins were homo- and heteropolymers of procyanidins, prodelphinidins, propelargonidins, and procyanidin gallate. From the enzyme analysis, the results showed that they could inhibit the monophenolase and diphenolase activities of tyrosinase. The inhibition mechanism of the proanthocyanidins on the enzyme was further studied, and the results indicated that they were reversible and competitive inhibitors. Finally, the results acquired from molecular docking, fluorescence quenching, and copper ion interacting tests revealed that adjacent hydroxyl groups on the B ring of proanthocyanidins could chelate the dicopper catalytic center of the enzyme. In addtion, proanthocyanidins were proven to be an efficient quencher of substrates. This study would lay a scientific foundation for their use in agriculture, food, and nutrition industries.

  3. Statin Adverse Effects: A Review of the Literature and Evidence for a Mitochondrial Mechanism

    PubMed Central

    Golomb, Beatrice A.; Evans, Marcella A.

    2009-01-01

    HMG-CoA reductase inhibitors (statins) are a widely used class of drug, and like all medications have potential for adverse effects (AEs). Here we review the statin AE literature, first focusing on muscle AEs as the most reported problem both in the literature and by patients. Evidence regarding the statin muscle AE mechanism, dose effect, drug interactions, and genetic predisposition is examined. We hypothesize, and provide evidence, that the demonstrated mitochondrial mechanisms for muscle AEs have implications to other nonmuscle AEs in patients treated with statins. In meta-analyses of randomized controlled trials (RCTs), muscle AEs are more frequent with statins than with placebo. A number of manifestations of muscle AEs have been reported, with rhabdomyolysis the most feared. AEs are dose dependent, and risk is amplified by drug interactions that functionally increase statin potency, often through inhibition of the cytochrome P450 (CYP)3A4 system. An array of additional risk factors for statin AEs are those that amplify (or reflect) mitochondrial or metabolic vulnerability, such as metabolic syndrome factors, thyroid disease, and genetic mutations linked to mitochondrial dysfunction. Converging evidence supports a mitochondrial foundation for muscle AEs associated with statins, and both theoretical and empirical considerations suggest that mitochondrial dysfunction may also underlie many non-muscle statin AEs. Evidence from RCTs and studies of other designs indicates existence of additional statin-associated AEs, such as cognitive loss, neuropathy, pancreatic and hepatic dysfunction, and sexual dysfunction. Physician awareness of statin AEs is reportedly low even for the AEs most widely reported by patients. Awareness and vigilance for AEs should be maintained to enable informed treatment decisions, treatment modification if appropriate, improved quality of patient care, and reduced patient morbidity. PMID:19159124

  4. Top-Down Control of Visual Alpha Oscillations: Sources of Control Signals and Their Mechanisms of Action.

    PubMed

    Wang, Chao; Rajagovindan, Rajasimhan; Han, Sahng-Min; Ding, Mingzhou

    2016-01-01

    Alpha oscillations (8-12 Hz) are thought to inversely correlate with cortical excitability. Goal-oriented modulation of alpha has been studied extensively. In visual spatial attention, alpha over the region of visual cortex corresponding to the attended location decreases, signifying increased excitability to facilitate the processing of impending stimuli. In contrast, in retention of verbal working memory, alpha over visual cortex increases, signifying decreased excitability to gate out stimulus input to protect the information held online from sensory interference. According to the prevailing model, this goal-oriented biasing of sensory cortex is effected by top-down control signals from frontal and parietal cortices. The present study tests and substantiates this hypothesis by (a) identifying the signals that mediate the top-down biasing influence, (b) examining whether the cortical areas issuing these signals are task-specific or task-independent, and (c) establishing the possible mechanism of the biasing action. High-density human EEG data were recorded in two experimental paradigms: a trial-by-trial cued visual spatial attention task and a modified Sternberg working memory task. Applying Granger causality to both sensor-level and source-level data we report the following findings. In covert visual spatial attention, the regions exerting top-down control over visual activity are lateralized to the right hemisphere, with the dipoles located at the right frontal eye field (FEF) and the right inferior frontal gyrus (IFG) being the main sources of top-down influences. During retention of verbal working memory, the regions exerting top-down control over visual activity are lateralized to the left hemisphere, with the dipoles located at the left middle frontal gyrus (MFG) being the main source of top-down influences. In both experiments, top-down influences are mediated by alpha oscillations, and the biasing effect is likely achieved via an inhibition

  5. Top-Down Control of Visual Alpha Oscillations: Sources of Control Signals and Their Mechanisms of Action

    PubMed Central

    Wang, Chao; Rajagovindan, Rajasimhan; Han, Sahng-Min; Ding, Mingzhou

    2016-01-01

    Alpha oscillations (8–12 Hz) are thought to inversely correlate with cortical excitability. Goal-oriented modulation of alpha has been studied extensively. In visual spatial attention, alpha over the region of visual cortex corresponding to the attended location decreases, signifying increased excitability to facilitate the processing of impending stimuli. In contrast, in retention of verbal working memory, alpha over visual cortex increases, signifying decreased excitability to gate out stimulus input to protect the information held online from sensory interference. According to the prevailing model, this goal-oriented biasing of sensory cortex is effected by top-down control signals from frontal and parietal cortices. The present study tests and substantiates this hypothesis by (a) identifying the signals that mediate the top-down biasing influence, (b) examining whether the cortical areas issuing these signals are task-specific or task-independent, and (c) establishing the possible mechanism of the biasing action. High-density human EEG data were recorded in two experimental paradigms: a trial-by-trial cued visual spatial attention task and a modified Sternberg working memory task. Applying Granger causality to both sensor-level and source-level data we report the following findings. In covert visual spatial attention, the regions exerting top-down control over visual activity are lateralized to the right hemisphere, with the dipoles located at the right frontal eye field (FEF) and the right inferior frontal gyrus (IFG) being the main sources of top-down influences. During retention of verbal working memory, the regions exerting top-down control over visual activity are lateralized to the left hemisphere, with the dipoles located at the left middle frontal gyrus (MFG) being the main source of top-down influences. In both experiments, top-down influences are mediated by alpha oscillations, and the biasing effect is likely achieved via an inhibition

  6. 19 CFR 4.76 - Procedures and responsibilities of carriers filing outbound vessel manifest information via the AES.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... outbound vessel manifest information via the AES. 4.76 Section 4.76 Customs Duties U.S. CUSTOMS AND BORDER... manifest information via the AES. (a) The sea carrier's module. The Sea Carrier's Module is a component of... information will be transmitted to Customs via AES for each shipment as far in advance of departure...

  7. Molecular oxygen measurements at 200 km from AE-D near winter solstice, 1975

    NASA Technical Reports Server (NTRS)

    Kayser, D. C.; Potter, W. E.

    1976-01-01

    Utilizing the fly-through mode, the open source neutral mass spectrometer on Atmosphere Explorer-D (AE-D) has measured O2 densities, as well as N2 densities and in situ neutral temperatures, at midmorning during winter solstice over the latitude range 90 degrees S to 90 degrees N. The expected seasonal variation in N2 was found at 200 km together with a more complex behavior in molecular oxygen than might be expected from a diffusive equilibrium model with constant lower boundary values. Under geomagnetically quiet conditions the equatorial 200 km value of O2 was about 1.7 x 10 to the 8th/cu cm. A local maximum in the 200 km O2 densities was found near 70 degrees N, where an average quiet time value was 2.5 x 10 to the 8th/cu cm, implying a 120 km density of 8.3 x 10 to the 10th/cu cm. The in situ temperature measurements confirm the presence of higher temperatures near 70 degrees N latitude, even during geomagnetically quiet conditions.

  8. Reprocessing of Archival Direct Imaging Data of Herbig Ae/Be Stars

    NASA Astrophysics Data System (ADS)

    Safsten, Emily; Stephens, Denise C.

    2017-01-01

    Herbig Ae/Be (HAeBe) stars are intermediate mass (2-10 solar mass) pre-main sequence stars with circumstellar disks. They are the higher mass analogs of the better-known T Tauri stars. Observing planets within these young disks would greatly aid in understanding planet formation processes and timescales, particularly around massive stars. So far, only one planet, HD 100546b, has been confirmed to orbit a HAeBe star. With over 250 HAeBe stars known, and several observed to have disks with structures thought to be related to planet formation, it seems likely that there are as yet undiscovered planetary companions within the circumstellar disks of some of these young stars.Direct detection of a low-luminosity companion near a star requires high contrast imaging, often with the use of a coronagraph, and the subtraction of the central star's point spread function (PSF). Several processing algorithms have been developed in recent years to improve PSF subtraction and enhance the signal-to-noise of sources close to the central star. However, many HAeBe stars were observed via direct imaging before these algorithms came out. We present here current work with the PSF subtraction program PynPoint, which employs a method of principal component analysis, to reprocess archival images of HAeBe stars to increase the likelihood of detecting a planet in their disks.

  9. [Analysis of metallic elements in refractory tantalum-niobium slag by ICP-AES].

    PubMed

    Wang, Xiao-Hui; Zheng, Shi-Li; Xu, Hong-Bin; Zhang, Yip

    2009-03-01

    A new method for analysing the contents of many metalic elements, such as Ta, Nb, Sn, Ti, W, Fe, Mn, Al, Pb, Ce, Y, Sc, Pr, Sm, Nd, U, Th etc, in refractory tantalum-niobium slag by ICP-AES was developed. The samples processing procedures involve two steps, being first decomposed by potassium carbonate and boric acid at 950 degrees C for 15 min, then leached by hydrochloride and tartaric acid at 90 degrees C for 30 min. The interference of flux and tin matrix in analyzing the other elements was eliminated by the utilization of matrix matching method. This method showed satisfactory precision and accuracy with the RSDs between 0.27% and 5.48% and the recovery rates between 94.0% and 109.6%. The analysis results indicated that highly valuable metals of Sn, Ta, Nb, Ti, W and Ce are rich in the refractory tantalum-niobium slag, showing that it has the great potential for comprehensive utilization. However, the analysis result also showed that the slag is a radioactive pollution source due to a small amount of U and Th. This method is simple and fast, and has the advantage of analyzing many elements simultaneously. The accurate analytic results provided a basis for the future researches on the comprehensive utilization of refractory tantalum-niobium slag.

  10. A Study of Ro-vibrational OH Emission from Herbig Ae/Be Stars

    NASA Astrophysics Data System (ADS)

    Brittain, Sean D.; Najita, Joan R.; Carr, John S.; Ádámkovics, Máté; Reynolds, Nickalas

    2016-10-01

    We present a study of ro-vibrational OH and CO emission from 21 disks around Herbig Ae/Be stars. We find that the OH and CO luminosities are proportional over a wide range of stellar ultraviolet luminosities. The OH and CO line profiles are also similar, indicating that they arise from roughly the same radial region of the disk. The CO and OH emission are both correlated with the far-ultraviolet luminosity of the stars, while the polycyclic aromatic hydrocarbon (PAH) luminosity is correlated with the longer wavelength ultraviolet luminosity of the stars. Although disk flaring affects the PAH luminosity, it is not a factor in the luminosity of the OH and CO emission. These properties are consistent with models of UV-irradiated disk atmospheres. We also find that the transition disks in our sample, which have large optically thin inner regions, have lower OH and CO luminosities than non-transition disk sources with similar ultraviolet luminosities. This result, while tentative given the small sample size, is consistent with the interpretation that transition disks lack a gaseous disk close to the star.

  11. AN IONIZED OUTFLOW FROM AB AUR, A HERBIG AE STAR WITH A TRANSITIONAL DISK

    SciTech Connect

    Rodríguez, Luis F.; Zapata, Luis A.; Ortiz-León, Gisela N.; Loinard, Laurent; Dzib, Sergio A.; Macías, Enrique; Anglada, Guillem

    2014-09-20

    AB Aur is a Herbig Ae star with a transitional disk. Transitional disks present substantial dust clearing in their inner regions, most probably because of the formation of one or more planets, although other explanations are still viable. In transitional objects, accretion is found to be about an order of magnitude smaller than in classical full disks. Since accretion is believed to be correlated with outflow activity, centimeter free-free jets are expected to be present in association with these systems, at weaker levels than in classical protoplanetary (full) systems. We present new observations of the centimeter radio emission associated with the inner regions of AB Aur and conclude that the morphology, orientation, spectral index, and lack of temporal variability of the centimeter source imply the presence of a collimated, ionized outflow. The radio luminosity of this radio jet is, however, about 20 times smaller than that expected for a classical system of similar bolometric luminosity. We conclude that centimeter continuum emission is present in association with stars with transitional disks, but at levels than are becoming detectable only with the upgraded radio arrays. On the other hand, assuming that the jet velocity is 300 km s{sup –1}, we find that the ratio of mass loss rate to accretion rate in AB Aur is ∼0.1, similar to that found for less evolved systems.

  12. Whistler wave-induced ionospheric plasma turbulence: Source mechanisms and remote sensing

    NASA Astrophysics Data System (ADS)

    Pradipta, R.; Rooker, L. A.; Whitehurst, L. N.; Lee, M. C.; Ross, L. M.; Sulzer, M. P.; Gonzalez, S.; Tepley, C.; Aponte, N.; See, B. Z.; Hu, K. P.

    2013-10-01

    We report a series of experiments conducted at Arecibo Observatory in the past, aimed at the investigation of 40.75 kHz whistler wave interactions with ionospheric plasmas and the inner radiation belts at L=1.35. The whistler waves are launched from a Naval transmitter (code-named NAU) operating in Aguadilla, Puerto Rico at the frequency and power of 40.75 kHz and 100 kW, respectively. Arecibo radar, CADI, and optical instruments were used to monitor the background ionospheric conditions and detect the induced ionospheric plasma effects. Four-wave interaction processes produced by whistler waves in the ionosphere can excite lower hybrid waves, which can accelerate ionospheric electrons. Furthermore, whistler waves propagating into the magnetosphere can trigger precipitation of energetic electrons from the radiation belts. Radar and optical measurements can distinguish wave-wave and wave-particle interaction processes occurring at different altitudes. Electron acceleration by different mechanisms can be verified from the radar measurements of plasma lines. To facilitate the coupling of NAU-launched 40.75 kHz whistler waves into the ionosphere, we can rely on naturally occurring spread F irregularities to serve as ionospheric ducts. We can also use HF wave-created ducts/artificial waveguides, as demonstrated in our earlier Arecibo experiments and recent Gakona experiments at HAARP. The newly constructed Arecibo HF heater will be employed in our future experiments, which can extend the study of whistler wave interactions with the ionosphere and the magnetosphere/radiation belts as well as the whistler wave conjugate propagation between Arecibo and Puerto Madryn, Argentina.

  13. Vibro-Acoustic Analysis of Computer Disk Drive Components with Emphasis on Electro-Mechanical Noise Sources.

    NASA Astrophysics Data System (ADS)

    Lee, Ming-Ran

    Vibro-acoustic characteristics of compact electro -mechanical devices are not well understood. This study examines fundamental research issues in this area through the example case of a 3.5" personal computer hard disk drive. In particular, a narrow band mathematical model of the drive has been developed to predict prominent pure tones over the high frequency range (1-6.5 KHz). Through detailed analytical studies, it has been found that the motor torque pulsation of the brushless d.c. motor is the source for this noise problem. Accordingly, a simplified disk drive model consisting of motor driving a single disk is used to investigate key components, with emphasis on the development of new mathematical models to describe the source, path and radiator characteristics. Two different mathematical models have been developed for brushless d.c. motor to predict the torque spectrum associated with invertor switching logic, pulse width modulation control scheme, eccentricity, and magnetic saturation. Frequency contents of predicted variables are identified and matched with measured sound data. Additionally, the Galerkin's method (or modified harmonic balance) is also employed successfully to develop an efficient computational scheme which predicts the Fourier coefficients of torque pulsations directly including various effects associated with inductance harmonics and the fluctuation of rotor angular velocity. For the radiator (annular disk), modal base formulations of sound radiation have been developed by approximating disk eigen-functions. Specifically, the effects of modal coupling and source rotation on radiated sound are investigated. Analytical predictions match well with numerical results obtained by using a boundary element program. New mobility transfer functions (path) are derived to couple the source and radiator formulations in order to construct an overall vibro-acoustic model. Potential areas of further research including experimental validation are discussed.

  14. Design and application of permanent magnet flux sources for mechanical testing of magnetoactive elastomers at variable field directions.

    PubMed

    Hiptmair, F; Major, Z; Haßlacher, R; Hild, S

    2015-08-01

    Magnetoactive elastomers (MAEs) are a class of smart materials whose mechanical properties can be rapidly and reversibly changed by an external magnetic field. Due to this tunability, they are useable for actuators or in active vibration control applications. An extensive magnetomechanical characterization is necessary for MAE material development and requires experiments under cyclic loading in uniform but variable magnetic fields. MAE testing apparatus typically rely on fields of adjustable strength, but fixed (transverse) direction, often provided by electromagnets. In this work, two permanent magnet flux sources were developed as an add-on for a modular test stand, to allow for mechanical testing in uniform fields of variable direction. MAE specimens, based on a silicone matrix with isotropic and anisotropic carbonyl iron particle distributions, were subjected to dynamic mechanical analysis under different field and loading configurations. The magneto-induced increase of stiffness and energy dissipation was determined by the change of the hysteresis loop area and dynamic modulus values. A distinct influence of the composite microstructure and the loading state was observed. Due to the very soft and flexible matrix used for preparing the MAE samples, the material stiffness and damping behavior could be varied over a wide range via the applied field direction and intensity.

  15. Thermo-mechanical analysis of a user filter assembly for undulator/wiggler operations at the Advanced Photon Source

    SciTech Connect

    Nian, H.L.T.; Kuzay, T.M.; Collins, J.; Shu, D.; Benson, C.; Dejus, R.

    1996-12-31

    This paper reports a thermo-mechanical study of a beamline filter (user filter) for undulator/wiggler operations. It is deployed in conjunction with the current commissioning window assembly on the APS insertion device (ID) front ends. The beamline filter at the Advanced Photon Source (APS) will eventually be used in windowless operations also. Hence survival and reasonable life expectancy of the filters under intense insertion device (ID) heat flu are crucial to the beamline operations. To accommodate various user requirements, the filter is configured to be a multi-choice type and smart to allow only those filter combinations that will be safe to operate with a given ring current and beamline insertion device gap. However, this paper addresses only the thermo-mechanical analysis of individual filter integrity and safety in all combinations possible. The current filter design is configured to have four filter frames in a cascade with each frame holding five filters. This allows a potential 625 total filter combinations. Thermal analysis for all of these combinations becomes a mammoth task considering the desired choices for filter materials (pyrolitic graphite and metallic filters), filter thicknesses, undulator gaps, and the beam currents. The paper addresses how this difficult task has been reduced to a reasonable effort and computational level. Results from thermo-mechanical analyses of the filter combinations are presented both in tabular and graphical format.

  16. Modifications in surface, structural and mechanical properties of brass using laser induced Ni plasma as an ion source

    NASA Astrophysics Data System (ADS)

    Ahmad, Shahbaz; Bashir, Shazia; Rafique, M. Shahid; Yousaf, Daniel

    2016-03-01

    Laser induced Ni plasma has been employed as source of ion implantation for surface, structural and mechanical properties of brass. Excimer laser (248 nm, 20 ns, 120mJ and 30 Hz) was used for the generation of Ni plasma. Thomson parabola technique was employed to estimate the energy of generated ions using CR39 as a detector. In response to stepwise increase in number of laser pulses from 3000 to 12000, the ion dose varies from 60 × 1013 to 84 × 1016 ions/cm2 with constant energy of 138 KeV. SEM analysis reveals the growth of nano/micro sized cavities, pores, pits, voids and cracks for the ion dose ranging from 60 × 1013 to 70 × 1015 ions/cm2. However, at maximum ion dose of 84 × 1016 ions/cm2 the granular morphology is observed. XRD analysis reveals that new phase of CuZnNi (200) is formed in the brass substrate after ion implantation. However, an anomalous trend in peak intensity, crystallite size, dislocation line density and induced stresses is observed in response to the implantation with various doses. The increase in ion dose causes to decrease the Yield Stress (YS), Ultimate Tensile Strength (UTS) and hardness. However, for the maximum ion dose the highest values of these mechanical properties are achieved. The variations in the mechanical properties are correlated with surface and crystallographical changes of ion implanted brass.

  17. 12. PWD Drawing 10,0005(463AE1)(1936), 'Electrical Lighting and Power' Mare ...

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

    12. PWD Drawing 10,000-5(463A-E-1)(1936), 'Electrical Lighting and Power' - Mare Island Naval Shipyard, Battery Test Office & Storage Facility, California Avenue & E Street, Vallejo, Solano County, CA

  18. The prediction of AE, ap, and Dst at time lags between 0 and 30 hours

    NASA Technical Reports Server (NTRS)

    Smart, D. F.; Garrett, H. B.; Shea, M. A.

    1979-01-01

    The magnetic activity indexes AE, ap, and Dst are correlated with approximately 35,000 hours of interplanetary plasma and magnetic field measurements acquired near the Earth (assembled by NASA/NSSDC into a composite data sat). Lag times between the indexes and solar wind parameters ranged from 0 to 30 hours. Correlations at lags less than 6 hours yield results in agreement with previous studies. At greater lags, the correlation coefficients between the solar wind parameters and AE and ap approach these parameters' autocorrelation (persistence) values. For Dst the correlation with solar wind parameters is lower than that with AE and ap in the 3 to 4 hour lag range whereas the autocorrelation of Dst is significantly higher over the entire 0 to 30 hour lag range. The implications of these differences between AE, ap, and Dst are discussed in terms of persistence of solar wind structure.

  19. AE analysis during corrosion, stress corrosion cracking and corrosion fatigue processes

    SciTech Connect

    Yuyama, S.; Kishi, T.

    1983-01-01

    Current theoretical and experimental research on the use of acoustic emission (AE) techniques for studying corrosion problems is reviewed. In particular, attention is given to the AE behavior of Type 304 stainless steel in aqueous environment, and a new method for analyzing corrosion, stress corrosion cracking, and corrosion fatigue in Type 304 steel is described. Results are also presented for other steels, aluminum and magnesium alloys, copper and its alloys, uranium alloys, and titanium and zirconium alloys. It is concluded that the AE method is a prommising approach to the detection and monitoring of localized corrosion in both laboratory specimens and engineering structures. Care must be taken, however, to discriminate valid AE signals from the background noise and to interpret the results correctly. 95 references.

  20. Characterization of Maize Amylose-extender (ae) Mutant Starches. Part II: Structures and Properties of Starch Residues Remaining After Enzymatic Hydrolyis at Boiling-water Temperature

    Technology Transfer Automated Retrieval System (TEKTRAN)

    GEMS-0067 maize ae-line starch developed by Truman State University and the Germplasm Enhancement of Maize (GEM) Project consisted of 39.4%-43.2% resistant-starch (RS), which was larger than the existing ae-line starches of H99ae, OH43ae, B89ae, and B84ae (11.5%-19.1%) as reported in part I of the s...

  1. Insights into the molecular level composition, sources, and formation mechanisms of dissolved organic matter in aerosols and precipitation

    NASA Astrophysics Data System (ADS)

    Altieri, Katye Elisabeth

    Atmospheric aerosols scatter and absorb light influencing the global radiation budget and climate, and are associated with adverse effects on human health. Precipitation is an important removal mechanism for atmospheric dissolved organic matter (DOM), and a potentially important input for receiving ecosystems. However, the sources, formation, and composition of atmospheric DOM in aerosols and precipitation are not well understood. This dissertation investigates the composition and formation mechanisms of secondary organic aerosol (SOA) formed through cloud processing reactions, elucidates the composition and sources of DOM in rainwater, and provides links connecting the two. Photochemical batch aqueous-phase reactions of organics with both biogenic and anthropogenic sources (i.e., methylglyoxal, pyruvic acid) and OH radical were performed to simulate cloud processing. The composition of products formed through cloud processing experiments and rainwater collected in New Jersey, USA was investigated using a combination of electrospray ionization mass spectrometry techniques, including ultra-high resolution Fourier transform ion cyclotron resonance mass spectrometry. This dissertation has resulted in the first evidence that oligomers form through cloud processing reactions, the first detailed chemical mechanism of aqueous phase oligomerization, the first identification of oligomers, organosulfates, and nitrooxy organosulfates in precipitation, and the first molecular level chemical characterization of organic nitrogen in precipitation. The formation of oligomers in SOA helps to explain the presence of large multifunctional compounds and humic like substances (HULIS) that dominate particulate organic mass. Oligomers have low vapor pressures and remain in the particle phase after cloud evaporation, enhancing SOA. The chemical properties of the oligomers suggest that they are less hygroscopic than the monomeric reaction products (i.e., organic acids). Their elemental

  2. Erecricins A-E, prenylated acylphloroglucinols from the roots of Hypericum erectum.

    PubMed

    Lu, Shuangxin; Tanaka, Naonobu; Tatano, Yutaka; Kashiwada, Yoshiki

    2016-10-01

    Six new prenylated acylphloroglucinols, erecricins A-E (1-5) and adotogirin (6), were isolated from the roots of Hypericum erectum (Hypericaceae). Their structures were assigned on the basis of spectroscopic evidences. Erecricins A-E (1-5) are bicyclic prenylated acylphloroglucinols possessing a chromane or a chromene skeleton. Adotogirin (6) is a simple achylphloroglucinol with an O-geranyl moiety. Antimicrobial activities of these acylphloroglucinols were also evaluated.

  3. Ultrasonic fatigue process analyzed by using LVD and continuous ae waveform analysis system

    NASA Astrophysics Data System (ADS)

    Shiwa, M.; Furuya, Y.; Yamawaki, H.; Ito, K.; Enoki, M.

    2012-05-01

    Non-linear ultrasonic parameter β and acoustic emission signals of ultrasonic fatigue testing were analyzed by using Laser Doppler Vibrometer and continuous AE waveform analysis system. Notched specimens of the high-strength low-alloy steel were prepared for the ultrasonic fatigue testing with exciting vibration frequency of 20 kHz. The AE events for each broken specimens were detected prior to the increase of β parameter.

  4. Stationary solutions for conservation laws with singular nonlocal sources

    NASA Astrophysics Data System (ADS)

    Coclite, Giuseppe Maria; Coclite, Mario Michele

    The existence of an a.e. positive stationary solution with bounded variation in [0,1] for an integro-differential conservation law with source depending on a function singular in the origin is proved.

  5. The structure and organization of the human erythroid anion exchanger (AE1) gene

    SciTech Connect

    Sahr, K.E.; Taylor, W.M.; Daniels, B.P.

    1994-12-01

    The AE1 (anion exchanger, band 3) protein is expressed in erythrocytes and in the A-type intercalated cells of the kidney distal collecting tubule. In both cell types it mediates the electroneutral transport of chloride and bicarbonate ions across the lipid bilayer, and, in erythrocytes, it also serves as the critical attachment site of the peripheral membrane skeleton. We have characterized the human AE1 gene using overlapping clones isolated from a phage library of human genomic DNA. The gene spans {approximately}20 kb and consists of 20 exons separated by 19 introns. The structure of the human AE1 gene corresponds closely with that of the previously characterized mouse AE1 gene, with a high degree of conservation of exon/intron junctions, as well as exon and intron nucleotide sequences. The putative upstream and internal promoter sequences of the human AE1 gene used in erythroid and kidney cells, respectively, are described. We also report the nucleotide sequence of the entire 3{prime} noncoding region of exon 20, which was lacking in the published cDNA sequences. In addition, we have characterized 9 Alu repeat elements found within the body of the human AE1 gene that are members of 4 related subfamilies that appear to have entered the genome at different times during primate evolution. 59 refs., 5 figs., 2 tabs.

  6. Rb-Sr and Sm-Nd isotope geochemistry and chronology of cherts from the Onverwacht Group (3.5 AE), South Africa

    NASA Technical Reports Server (NTRS)

    Weis, D.; Wasserburg, G. J.

    1987-01-01

    An Rb-Sr and Sm-Nd isotopic analysis of Archean chert samples from the Onverwacht Group, South Africa is presented, showing the same characteristic Rb and Sr concentrations as Phanerozoic cherts, with a very large range of Rb-87/Sr-86 ratios. A good correlation line in the Rb-87 to Sr-87 evolution diagram, corresponding to an age of about 2119 My and an initial Sr-87/Sr-86 ratio of about 0.72246, is derived which may be interpreted as reflecting the age of rehomogenization of the Sr in the protolith and the recrystallization of these cherts due to circulating hydrothermal fluids during regional metamorphism about 1.4 AE after deposition of the Onverwacht Group. The Sm-Nd systematics reflect an ancient source age of about 3.5 AE.

  7. Unified physical mechanism of frequency-domain controlled-source electromagnetic exploration on land and in ocean

    NASA Astrophysics Data System (ADS)

    Liu, Changsheng; Lin, Jun; Zhou, Fengdao; Hu, Ruihua; Sun, Caitang

    2013-12-01

    The frequency-domain controlled-source electromagnetic method (FDCSEM) has played an important role in the terrestrial and oceanic exploration. However, the measuring manners and the detecting abilities in two kinds of environment are much different. This paper analyses the electromagnetic theories of the FDCSEM exploration on land and in ocean, simulates the electromagnetic responses in the two cases based on a united physical and mathematical model, and studies the physical mechanism leading to these differences. In this study, the relationship between the propagation paths and the detecting ability is illuminated and the way to improve the detecting ability of FDCSEM is brought forward. In terrestrial exploration, FDCSEM widely adopts the measuring manner of controlled-source audio-frequency magnetotelluric method (CSAMT), which records the electromagnetic fields in the far zone in the broadside direction of an electric dipole source. This manner utilizes the airwave (i.e. the Earth surface wave) and takes the stratum wave as interference. It is sensitive to the conductive target but insensitive to the resistive one. In oceanic exploration, FDCSEM usually adopts the measuring manner of marine controlled-source electromagnetic method (MCSEM), which records the electromagnetic fields, commonly the horizontal electric fields, in the in-line direction of the electric dipole source. This manner utilizes the stratum wave (i.e. the seafloor wave and the guided wave in resistive targets) and takes the airwave as interference. It is sensitive to the resistive target but relatively insensitive to the conductive one. The numerical simulation shows that both the airwave and the stratum wave contribute to the FDCSEM exploration. United utilization of them will enhance the anomalies of targets and congregate the advantages of CSAMT and MCSEM theories. At different azimuth and different offset, the contribution of the airwave and the stratum wave to electromagnetic anomaly is

  8. Synthesis, Crystal and Electronic Structures of the Pnictides AE3TrPn3 (AE = Sr, Ba; Tr = Al, Ga; Pn = P, As)

    DOE PAGES

    Stoyko, Stanislav; Voss, Leonard; He, Hua; ...

    2015-09-24

    New ternary arsenides AE3TrAs3 (AE = Sr, Ba; Tr = Al, Ga) and their phosphide analogs Sr3GaP3 and Ba3AlP3 have been prepared by reactions of the respective elements at high temperatures. Single-crystal X-ray diffraction studies reveal that Sr3AlAs3 and Ba3AlAs3 adopt the Ba3AlSb3-type structure (Pearson symbol oC56, space group Cmce, Z = 8). This structure is also realized for Sr3GaP3 and Ba3AlP3. Likewise, the compounds Sr3GaAs3 and Ba3GaAs3 crystallize with the Ba3GaSb3-type structure (Pearson symbol oP56, space group Pnma, Z = 8). Both structures are made up of isolated pairs of edge-shared AlPn4 and GaPn4 tetrahedra (Pn = pnictogen, i.e.,more » P or As), separated by the alkaline-earth Sr2+ and Ba2+ cations. In both cases, there are no homoatomic bonds, hence, regardless of the slightly different atomic arrangements, both structures can be rationalized as valence-precise [AE2+]3[Tr3+][Pn3-]3, or rather [AE2+]6[Tr2Pn6]12-, i.e., as Zintl phases.« less

  9. Testing quantum mechanics in non-Minkowski space-time with high power lasers and 4th generation light sources

    PubMed Central

    Crowley, B. J. B.; Bingham, R.; Evans, R. G.; Gericke, D. O.; Landen, O. L.; Murphy, C. D.; Norreys, P. A.; Rose, S. J.; Tschentscher, Th; Wang, C. H.-T; Wark, J. S.; Gregori, G.

    2012-01-01

    A common misperception of quantum gravity is that it requires accessing energies up to the Planck scale of 1019 GeV, which is unattainable from any conceivable particle collider. Thanks to the development of ultra-high intensity optical lasers, very large accelerations can be now the reached at their focal spot, thus mimicking, by virtue of the equivalence principle, a non Minkowski space-time. Here we derive a semiclassical extension of quantum mechanics that applies to different metrics, but under the assumption of weak gravity. We use our results to show that Thomson scattering of photons by uniformly accelerated electrons predicts an observable effect depending upon acceleration and local metric. In the laboratory frame, a broadening of the Thomson scattered x ray light from a fourth generation light source can be used to detect the modification of the metric associated to electrons accelerated in the field of a high power optical laser. PMID:22768381

  10. A plasma source driven predator-prey like mechanism as a potential cause of spiraling intermittencies in linear plasma devices

    SciTech Connect

    Reiser, D.; Ohno, N.; Tanaka, H.; Vela, L.

    2014-03-15

    Three-dimensional global drift fluid simulations are carried out to analyze coherent plasma structures appearing in the NAGDIS-II linear device (nagoya divertor plasma Simulator-II). The numerical simulations reproduce several features of the intermittent spiraling structures observed, for instance, statistical properties, rotation frequency, and the frequency of plasma expulsion. The detailed inspection of the three-dimensional plasma dynamics allows to identify the key mechanism behind the formation of these intermittent events. The resistive coupling between electron pressure and parallel electric field in the plasma source region gives rise to a quasilinear predator-prey like dynamics where the axisymmetric mode represents the prey and the spiraling structure with low azimuthal mode number represents the predator. This interpretation is confirmed by a reduced one-dimensional quasilinear model derived on the basis of the findings in the full three-dimensional simulations. The dominant dynamics reveals certain similarities to the classical Lotka-Volterra cycle.

  11. Mechanism of hydrolysis of native and cooked starches from different botanical sources in the presence of tea extracts.

    PubMed

    Guzar, Igor; Ragaee, Sanaa; Seetharaman, Koushik

    2012-11-01

    A series of experiments were conducted to highlight the mechanism of inhibition of hydrolysis and differences in hydrolysis among starches from different sources in the presence of green or black tea extract. The first experiment showed that black tea extract was more effective at reducing final viscosity for all starches. The second experiment showed that black tea was more effective at inhibiting starch hydrolysis compared to green tea when starch, tea extract, and pancreatin were added at the beginning of pasting. The third experiment, when starches were pretreated with tea extracts, showed that both treatments reduced starch hydrolysis. Analysis of supernatant free phenolic content and of soluble dextrins showed that amyloglucosidase activity was affected, with exceptions for potato starch. These observations suggest that starch hydrolysis is affected by interactions and also by the impact on specific enzymes based on starch structure.

  12. Final design, fluid dynamic and structural mechanical analysis of a liquid hydrogen Moderator for the European Spallation Source

    NASA Astrophysics Data System (ADS)

    Bessler, Y.; Henkes, C.; Hanusch, F.; Schumacher, P.; Natour, G.; Butzek, M.; Klaus, M.; Lyngh, D.; Kickulies, M.

    2017-02-01

    The European Spallation Source (ESS) is currently in the construction phase and should have first beam on Target in 2019. ESS, located in Sweden, will be the most powerful spallation neutron source worldwide, with the goal to produce neutrons for research. As an in-kind partner the Forschungszentrum Juelich will among others, design and manufacture the four liquid hydrogen Moderators, which are located above and below the Target. Those vessels are confining the cold hydrogen used to reduce the energy level of the fast neutrons, produced by spallation in the Target, in order to make the neutrons usable for neutron scattering instruments. Due to the requirements [1], a fluid dynamic analysis with pressure and temperature depended hydrogen data, taking into account the pseudo critical phenomena and the pulsed neutronic heating (pressure waves) is necessary. With the fluid dynamic results, a structure mechanical analysis including radiation damage investigation (RCC-MRx code [5]), low temperature properties as well as strength reduction by welding can be realized. Finally, the manufacturing and welding completes the design process.

  13. Size distributions of polycyclic aromatic hydrocarbons in urban atmosphere: sorption mechanism and source contributions to respiratory deposition

    NASA Astrophysics Data System (ADS)

    Lv, Yan; Li, Xiang; Xu, Ting Ting; Cheng, Tian Tao; Yang, Xin; Chen, Jian Min; Iinuma, Yoshiteru; Herrmann, Hartmut

    2016-03-01

    In order to better understand the particle size distribution of polycyclic aromatic hydrocarbons (PAHs) and their source contribution to human respiratory system, size-resolved PAHs have been studied in ambient aerosols at a megacity Shanghai site during a 1-year period (2012-2013). The results showed the PAHs had a bimodal distribution with one mode peak in the fine-particle size range (0.4-2.1 µm) and another mode peak in the coarse-particle size range (3.3-9.0 µm). Along with the increase in ring number of PAHs, the intensity of the fine-mode peak increased, while the coarse-mode peak decreased. Plotting of log(PAH / PM) against log(Dp) showed that all slope values were above -1, suggesting that multiple mechanisms (adsorption and absorption) controlled the particle size distribution of PAHs. The total deposition flux of PAHs in the respiratory tract was calculated as being 8.8 ± 2.0 ng h-1. The highest lifetime cancer risk (LCR) was estimated at 1.5 × 10-6, which exceeded the unit risk of 10-6. The LCR values presented here were mainly influenced by accumulation mode PAHs which came from biomass burning (24 %), coal combustion (25 %), and vehicular emission (27 %). The present study provides us with a mechanistic understanding of the particle size distribution of PAHs and their transport in the human respiratory system, which can help develop better source control strategies.

  14. Mechanical Design and Analysis of a 200 MHz, Bolt-together RFQ forthe Accelerator Driven Neutron Source

    SciTech Connect

    Virostek, Steve; Hoff, Matt; Li, Derun; Staples, John; Wells,Russell

    2007-06-20

    A high-yield neutron source to screen sea-land cargocontainers for shielded Special Nuclear Materials (SNM) has been designedat LBNL [1,2]. The Accelerator-Driven Neutron Source (ADNS) uses theD(d,n)3He reaction to create a forward directed neutron beam. Keycomponents are a high-current radio-frequency quadrupole (RFQ)accelerator and a high-power target capable of producing a neutron fluxof>107 n/(cm2 cdot s) at a distance of 2.5 m. The mechanical designand analysis of the four-module, bolt-together RFQ will be presentedhere. Operating at 200 MHz, the 5.1 m long RFQ will accelerate a 40 mAdeuteron beam to 6 MeV. At a 5 percent duty factor, the time-average d+beam current on target is 1.5 mA. Each of the 1.27 m long RFQ moduleswill consist of four solid OFHC copper vanes. A specially designed 3-DO-ring will provide vacuum sealing between both the vanes and themodules. RF connections are made with canted coil spring contacts. Aseries of 60 water-cooled pi-mode rods provides quadrupole modestabilization. A set of 80 evenly spaced fixed slug tuners is used forfinal frequency adjustment and local field perturbationcorrection.

  15. Hydroacoustic records and a numerical model of the source mechanism from the first historical eruption of Anatahan Volcano, Mariana Islands

    NASA Astrophysics Data System (ADS)

    Dziak, R. P.; Park, M.; Matsumoto, H.; Byun, S.-K.

    2005-08-01

    Anatahan Volcano in the Commonwealth of the Northern Mariana Islands (CNMI) erupted for the first time in recorded history on 10 May 2003. The underwater acoustic records ( T-waves) of earthquakes, explosions, and tremor produced during the eruption were recorded on a sound channel hydrophone deployed in February 2003. Acoustic propagation models show that the seismic to acoustic conversion at Anatahan is particularly efficient, aided by the upward slope of the seamount toward the hydrophone. The hydrophone records confirm the onset of earthquake activity between 0100 and 0200Z on 10 May, with a substantial increase in seismicity beginning at ˜ 0620Z. In addition, the onset of continuous, low-frequency (3-40 Hz) acoustic energy that is likely volcanic tremor related to magma intrusion was also observed at 0620Z. The hydrophone recorded 1401 earthquakes during the first 3 days of the eruption. A histogram of seismicity indicates two main periods of explosion/eruption activity, the first beginning at ˜ 0620Z on 10 May and the second at ˜ 0000Z on 11 May. Relative earthquake depth estimates indicate that both eruption periods were accompanied by earthquake activity from deep within the Anatahan volcanic edifice. A numerical representation of the Anatahan volcano-seismic source was developed to examine the character of acoustic signals generated from the eruption governed by the geometry of the source and the physical properties of the magma. A magma pipe source mechanism is used to compute the seismo-acoustic wavefield on the flank of the Anatahan volcanic edifice (on the seafloor and in the water column) due to mode conversion by roughness scattering. A fluid-filled pipe model was chosen because it allows for a more straightforward relation between volcano geometry and spectral features of harmonic tremor as well as its morphologic similarity to a submerged volcanic edifice.

  16. Monitoring of temperature fatigue failure mechanism for polyvinyl alcohol fiber concrete using acoustic emission sensors.

    PubMed

    Li, Dongsheng; Cao, Hai

    2012-01-01

    The applicability of acoustic emission (AE) techniques to monitor the mechanism of evolution of polyvinyl alcohol (PVA) fiber concrete damage under temperature fatigue loading is investigated. Using the temperature fatigue test, real-time AE monitoring data of PVA fiber concrete is achieved. Based on the AE signal characteristics of the whole test process and comparison of AE signals of PVA fiber concretes with different fiber contents, the damage evolution process of PVA fiber concrete is analyzed. Finally, a qualitative evaluation of the damage degree is obtained using the kurtosis index and b-value of AE characteristic parameters. The results obtained using both methods are discussed.

  17. Automated logging of inspiratory and expiratory non-synchronized breathing (ALIEN) for mechanical ventilation.

    PubMed

    Chiew, Yeong Shiong; Pretty, Christopher G; Beatson, Alex; Glassenbury, Daniel; Major, Vincent; Corbett, Simon; Redmond, Daniel; Szlavecz, Akos; Shaw, Geoffrey M; Chase, J Geoffrey

    2015-01-01

    Asynchronous Events (AEs) during mechanical ventilation (MV) result in increased work of breathing and potential poor patient outcomes. Thus, it is important to automate AE detection. In this study, an AE detection method, Automated Logging of Inspiratory and Expiratory Non-synchronized breathing (ALIEN) was developed and compared between standard manual detection in 11 MV patients. A total of 5701 breaths were analyzed (median [IQR]: 500 [469-573] per patient). The Asynchrony Index (AI) was 51% [28-78]%. The AE detection yielded sensitivity of 90.3% and specificity of 88.3%. Automated AE detection methods can potentially provide clinicians with real-time information on patient-ventilator interaction.

  18. Multi-Physics Modelling of Fault Mechanics Using REDBACK: A Parallel Open-Source Simulator for Tightly Coupled Problems

    NASA Astrophysics Data System (ADS)

    Poulet, Thomas; Paesold, Martin; Veveakis, Manolis

    2017-03-01

    Faults play a major role in many economically and environmentally important geological systems, ranging from impermeable seals in petroleum reservoirs to fluid pathways in ore-forming hydrothermal systems. Their behavior is therefore widely studied and fault mechanics is particularly focused on the mechanisms explaining their transient evolution. Single faults can change in time from seals to open channels as they become seismically active and various models have recently been presented to explain the driving forces responsible for such transitions. A model of particular interest is the multi-physics oscillator of Alevizos et al. (J Geophys Res Solid Earth 119(6), 4558-4582, 2014) which extends the traditional rate and state friction approach to rate and temperature-dependent ductile rocks, and has been successfully applied to explain spatial features of exposed thrusts as well as temporal evolutions of current subduction zones. In this contribution we implement that model in REDBACK, a parallel open-source multi-physics simulator developed to solve such geological instabilities in three dimensions. The resolution of the underlying system of equations in a tightly coupled manner allows REDBACK to capture appropriately the various theoretical regimes of the system, including the periodic and non-periodic instabilities. REDBACK can then be used to simulate the drastic permeability evolution in time of such systems, where nominally impermeable faults can sporadically become fluid pathways, with permeability increases of several orders of magnitude.

  19. The puzzle of the 1996 Bárdarbunga, Iceland, earthquake: no volumetric component in the source mechanism

    USGS Publications Warehouse

    Tkalcic, Hrvoje; Dreger, Douglas S.; Foulger, Gillian R.; Julian, Bruce R.

    2009-01-01

    A volcanic earthquake with Mw 5.6 occurred beneath the Bárdarbunga caldera in Iceland on 29 September 1996. This earthquake is one of a decade-long sequence of  events at Bárdarbunga with non-double-couple mechanisms in the Global Centroid Moment Tensor catalog. Fortunately, it was recorded well by the regional-scale Iceland Hotspot Project seismic experiment. We investigated the event with a complete moment tensor inversion method using regional long-period seismic waveforms and a composite structural model. The moment tensor inversion using data from stations of the Iceland Hotspot Project yields a non-double-couple solution with a 67% vertically oriented compensated linear vector dipole component, a 32% double-couple component, and a statistically insignificant (2%) volumetric (isotropic) contraction. This indicates the absence of a net volumetric component, which is puzzling in the case of a large volcanic earthquake that apparently is not explained by shear slip on a planar fault. A possible volcanic mechanism that can produce an earthquake without a volumetric component involves two offset sources with similar but opposite volume changes. We show that although such a model cannot be ruled out, the circumstances under which it could happen are rare.

  20. Molecule formation mechanisms of strontium mono fluoride in high-resolution continuum source electrothermal atomic absorption spectrometry.

    PubMed

    Ozbek, Nil; Akman, Suleyman

    2013-01-01

    In this study, the molecule formation mechanisms of strontium mono fluoride used for the determination of fluorine in a high-resolution continuum source atomic absorption spectrophotometer was investigated. To distinguish between the gas-phase and the condensed-phase mechanisms, the analyte (F) and the molecule forming element (Sr) were injected on the solid sampling platform manually, as mixed or separately, and the absorbances/peak shapes were compared. There was no significant difference between the absorbances. In addition, the peak shapes and the appearance times were almost the same for the two cases. It was proposed that the main pathway for SrF formation is a gas-phase combination reaction between Sr and F. When Sr and F were mixed on the platform, it was expected that at first SrF2 would be formed in the condensed phase, and then at elevated temperatures it was partly decomposed while either losing one F atom to form SrF, or completely decomposed to its atoms in the gas phase.

  1. Geodetic constraints to the source mechanism of the 2011-2013 unrest at Campi Flegrei (Italy) caldera

    NASA Astrophysics Data System (ADS)

    Trasatti, Elisa; Polcari, Marco; Bonafede, Maurizio; Stramondo, Salvatore

    2016-04-01

    Campi Flegrei (Italy) is a nested caldera and together with Vesuvius is one of the Italian GEO Geohazard Supersites (GSNL). The area is characterized by one of the highest volcanic hazard of the world, due to the very high density of inhabitants (1800/km²), the persistent activity of the system and the explosive character of volcanism. A major unrest episode took place in 1982-84, when the town of Pozzuoli, located at the caldera center, was uplifted by 1.80 m. Minor uplifts of few centimeters, seismic swarms and degassing episodes took place in 1989, 2000 and 2004-06. Since 2005 Campi Flegrei is uplifting, reaching a ground velocity of 9 cm/yr in 2012, showing that the caldera is in a critical state on the verge of instability. In this work, we present results from SAR Interferometry and geodetic data modelling at Campi Flegrei in the framework of the EU's FP7 MED-SUV Project. We exploit two COSMO-SkyMed data sets to map the deformation field during 2011-2013. The spatial distributions of the cumulative displacement from COSMO-SkyMed ascending/descending orbits show similar behaviors, confirming the bell-shaped pattern of the deformation at least within the inner rim of the caldera. The resulting data, together with GPS data from the Neapolitan Volcanoes Continuous GPS network (NeVoCGPS) is fitted through a geophysical inversion process using finite element forward models to account for the 3D heterogeneous medium. The best fit model is a north dipping mixed-mode dislocation source lying at ~5 km depth. The driving mechanism is ascribable to magma input into the source of the large 1982-1984 unrest (since similar source characteristics were inferred) that generates initial inflation followed by additional shear slip accompanying the extension of crack tips. The history and the current state of the system indicate that Campi Flegrei is able to erupt again. Constraining the defomation source may have important implications in terms of civil protection and the

  2. Optimal Procurement Mechanisms for Divisible Goods with Capacitated Suppliers

    DTIC Science & Technology

    2007-08-31

    capacities satisfies a modified regularity condition (Myerson, 1981). We also present a sealed low bid implementation of the optimal direct mechanism for the...is the same as that of a buyer facing a single supplier with piece wise linear convex production cost c(x). Clearly, multi-sourcing is optimal with a...is still optimal for her to bid the cost truthfully. Since πi(ci, qi) is convex in ci, (8) implies that ∂πi(c, q) ∂c = −Xi(c, q), a.e. (9

  3. Crustal stress, seismicity, acoustic emission (AE), and tectonics: the Kefallinì;a (Greece) case study

    NASA Astrophysics Data System (ADS)

    Gregori, G. P.; Poscolieri, M.; Paparo, G.; Ventrice, G.; de Simone, S.; Rafanelli, C.

    2009-04-01

    New inferences - confirming previous results (see references)- are presented dealing with a few years Acoustic Emission (AE) records collected at Kefallinìa (Ionian Islands, Greece). A physical distinction between HF (high frequency) vs. LF (low frequency) AE is required. Step-wise changes of the AE underground conductivity are evidenced, and can be suitably handled. "Smooth" results concern (i) the annual variation, (ii) some long-lasting stress "solitons" crossing through the area, and (iii) tidal effects. In particular, every AE station can be operated like a monitoring station both for Earth's tides and for the free oscillations of the Earth. In addition, Kefallinìa exhibits a much peculiar groundwater circulation, in which conduit flow is dominant, that originates a specific (and unique) AE effect. By means of AE time-series analysis, "extreme" or "catastrophic" events can be also monitored and possibly related to relevant tectonic occurrences (either earthquakes, or maybe other occasional phenomena). They can be investigated, and have a regional - rather than local - character. Therefore, every interpretation based on a single station record - being biased by some arbitrariness - can only result indicative. A standardized procedure and software is proposed for routine AE data handling and analysis. References.: Lagios et al., 2004. In Proc. SCI 2004 (The 8th World Multi-Conference on Systemics, Cybernetics and Informatic), Orlando, Florida, July 1004, 6 pp. Poscolieri et al., 2006. In. G. Cello and B. D. Malamud, (eds), 2006. Geol. Soc. London, Special Publ., 261, 63-78. Poscolieri et al., 2006a. Nat. Hazards Earth Syst. Sci., 6, 961-971.

  4. Derivative of Extremophilic 50S Ribosomal Protein L35Ae as an Alternative Protein Scaffold

    PubMed Central

    Lomonosova, Anna V.; Ulitin, Andrei B.; Kazakov, Alexei S.; Mirzabekov, Tajib A.; Permyakov, Eugene A.

    2017-01-01

    Small antibody mimetics, or alternative binding proteins (ABPs), extend and complement antibody functionality with numerous applications in research, diagnostics and therapeutics. Given the superiority of ABPs, the last two decades have witnessed development of dozens of alternative protein scaffolds (APSs) for the design of ABPs. Proteins from extremophiles with their high structural stability are especially favorable for APS design. Here, a 10X mutant of the 50S ribosomal protein L35Ae from hyperthermophilic archaea Pyrococcus horikoshii has been probed as an APS. A phage display library of L35Ae 10X was generated by randomization of its three CDR-like loop regions (repertoire size of 2×108). Two L35Ae 10X variants specific to a model target, the hen egg-white lysozyme (HEL), were isolated from the resulting library using phage display. The affinity of these variants (L4 and L7) to HEL ranges from 0.10 μM to 1.6 μM, according to surface plasmon resonance data. While L4 has 1–2 orders of magnitude lower affinity to HEL homologue, bovine α-lactalbumin (BLA), L7 is equally specific to HEL and BLA. The reference L35Ae 10X is non-specific to both HEL and BLA. L4 and L7 are more resistant to denaturation by guanidine hydrochloride compared to the reference L35Ae 10X (mid-transition concentration is higher by 0.1–0.5 M). Chemical crosslinking experiments reveal an increased propensity of L4 and L7 to multimerization. Overall, the CDR-like loop regions of L35Ae 10X represent a proper interface for generation of functional ABPs. Hence, L35Ae is shown to extend the growing family of protein scaffolds dedicated to the design of novel binding proteins. PMID:28103321

  5. Determination of heavy metal concentrations in plants exposed to different degrees of pollution using ICP-AES.

    PubMed

    Kos, V; Budic, B; Hudnik, V; Lobnik, F; Zupan, M

    1996-03-01

    Plant samples (Plantago lanceolata - narrow leaf plantain and Cichorium endiviae - endive) were collected in the surroundings of heavy metal emission sources and in other less contaminated areas. After digestion in a closed microwave system using HNO(3), the concentrations of Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, and Zn were determined using ICP-AES. Detection limits for all the elements of interest are given. Differences in heavy metal uptake rate between both plant species were observed. The uptake is more intensive for endive than for narrow leaf plantain. High concentrations of some heavy metals were determined in the unwashed plant samples as a result of exposure to aerosols. Tukey's statistical test was used to confirm the discrepancy of Cr concentration in plant samples from various areas. Washing the leaves with water was found to remove a large amount of water-soluble aerosols.

  6. Adverse Effects (AEs) of Topical NSAIDs in Older Adults with Osteoarthritis (OA): a Systematic Review of the Literature

    PubMed Central

    Makris, UE.; Kohler, MJ.; Fraenkel, L.

    2010-01-01

    Objective To systematically review the literature on reported adverse effects (AEs) associated with topical NSAID use in older adults with osteoarthritis (OA). Methods A systematic search of Medline (1950 to November 2009), Scopus, Embase, Web of Science, Cochrane databases, Dissertation and American College of Rheumatology Meeting Abstracts was performed to identify original randomized controlled trials, case reports, observational studies, editorials or dissertations reporting AEs from topical NSAIDs in older adults with OA. Information was sought on study and participant characteristics, detailed recording of application site and systemic AEs as well as withdrawals due to AEs. Results The initial search yielded 953 articles of which 19 met eligibility criteria. Subjects receiving topical NSAIDs reported up to 39.3% application site AEs, and up to 17.5% systemic AEs. Five cases of warfarin potentiation with topical agents were reported; 1 resulting in gastrointestinal bleeding. In formal trials, the withdrawal rate from AEs ranged from 0-21% in the topical agents, 0-25% in the oral NSAIDs, and 0-16% in the placebo group. Conclusion In summary, although topical NSAIDs are safer than oral NSAIDs (fewer severe gastrointestinal AEs), a substantial proportion of older adults report systemic AEs with topical agents. Moreover, the withdrawal rate due to AEs with topical agents is comparable to that of oral NSAIDs. Given the safety profile and withdrawal rates described in this study, further data are needed to determine the incremental benefits of topical NSAIDs compared to other treatment modalities in older adults with OA. PMID:20360183

  7. Spatial Distribution of Landslides Triggered by the 2008 Wenchuan Earthquake: Implications for Landslide Fluvial Mobilization and Earthquake Source Mechanism

    NASA Astrophysics Data System (ADS)

    Li, G.; West, A.; Hilton, R. G.

    2013-12-01

    Assessing the spatial distribution of earthquake-induced landslides is important for quantifying the fluvial evacuation of landslide material [Hovius et al., 2011], for deriving information about earthquake sources [Meunier et al., 2013], and for understanding the role of earthquakes in shaping surface topography and in driving orogen evolution. The 2008 Mw 7.9 Wenchuan earthquake is characterized by large magnitude, widespread coseismic landsliding, typical mountainous ridge-and-valley topography of the region, and comprehensive geophysical observation. Previous work on landslides associated with the Wenchuan earthquake has focused on the occurrences of landslide-induced hazards and spatial relations between the landslide locations and the seismic features (i.e., the surface ruptures and the epicenter) [e.g., Dai et al., 2011; Gorum et al., 2011]. Little attention has been paid to how the landslide distribution determines the fluvial mobilization of landslide material or quantitative landslide-earthquake source mechanism inversion, even though the Wenchuan event provides an ideal case study to explore these problems for a larger magnitude earthquake than has yet been considered. We obtained a landslide inventory for the 2008 Wenchuan earthquake using high-resolution remote imagery and a semi-automated mapping algorithm. Here we report the results from spatial and statistical analysis of this landslide map using a digital elevation model (DEM) framework. We present the probability distribution of primary parameters (i.e., slope, aspect, elevation, and area density of all landslides) of the landslide inventory and discuss their relations to regional topographic features (i.e., river channels and mountain ridges). The landslide-river channel connectivity and landslide mobility were estimated using different hillslope-channel transition cutoffs. The landslide density and the probability of slope failure were calculated for all lithological units within the Longmen

  8. Complete chloroplast genomes of Aegilops tauschii Coss. and Ae. cylindrica Host sheds light on plasmon D evolution.

    PubMed

    Gogniashvili, Mari; Jinjikhadze, Tamar; Maisaia, Inesa; Akhalkatsi, Maia; Kotorashvili, Adam; Kotaria, Nato; Beridze, Tengiz; Dudnikov, Alexander Ju

    2016-11-01

    Hexaploid wheat (Triticum aestivum L., genomes AABBDD) originated in South Caucasus by allopolyploidization of the cultivated Emmer wheat T. dicoccum (genomes AABB) with the Caucasian Ae. tauschii ssp strangulata (genomes DD). Genetic variation of Ae. tauschii is an important natural resource, that is why it is of particular importance to investigate how this variation was formed during Ae. tauschii evolutionary history and how it is presented through the species area. The D genome is also found in tetraploid Ae. cylindrica Host (2n = 28, CCDD). The plasmon diversity that exists in Triticum and Aegilops species is of great significance for understanding the evolution of these genera. In the present investigation the complete nucleotide sequence of plasmon D (chloroplast DNA) of nine accessions of Ae. tauschii and two accessions of Ae. cylindrica are presented. Twenty-eight SNPs are characteristic for both TauL1 and TauL2 accessions of Ae. tauschii using TauL3 as a reference. Four SNPs are additionally observed for TauL2 lineage. The longest (27 bp) indel is located in the intergenic spacer Rps15-ndhF of SSC. This indel can be used for simple determination of TauL3 lineage among Ae. tauschii accessions. In the case of Ae. cylindrica additionally 7 SNPs were observed. The phylogeny tree shows that chloroplast DNA of TauL1 and TauL2 diverged from the TauL3 lineage. TauL1 lineage is relatively older then TauL2. The position of Ae. cylindrica accessions on Ae. tauschii phylogeny tree constructed on chloroplast DNA variation data is intermediate between TauL1 and TauL2. The complete nucleotide sequence of chloroplast DNA of Ae. tauschii and Ae. cylindrica allows to refine the origin and evolution of D plasmon of genus Aegilops.

  9. Classification of acoustic emission sources produced by carbon/epoxy composite based on support vector machine

    NASA Astrophysics Data System (ADS)

    Ding, Peng; Li, Qin; Huang, Xunlei

    2015-07-01

    Carbon/epoxy specimens were made and stretched to fracture. In the process, acoustic emission (AE) signals were collected and their parameters were set as the input parameters of the neural network. Results show that using support vector machine (SVM) network can recognize the difference of AE sources more accurately than using the BP neural network. In addition, the accuracy of the SVM increases when the number of the training set increases. It is proved that using AE signal parameters and SVM network can recognize the AE sources’ pattern well.

  10. Thermo-mechanical analysis of fixed mask 1 for the Advanced Photon Source insertion device front ends

    SciTech Connect

    Nian, H.L.T.; Shu, D.; Sheng, I.C.A.; Kuzay, T.M.

    1993-10-01

    The first fixed mask (FM1) is one of the critical elements on the insertion device front ends of the beamlines at the Advanced Photon Source (APS) now under construction at Argonne National Laboratory (ANL). The heat flux from the APS undulators is enormous. For example, FM1 placed at a distance of 16 m from the Undulator A source will be subjected to 519 W/mm{sup 2} at normal incidence with a total power of 3.8 kW. Due to a high localized thermal gradient on this component, inclined geometry (1.5{degree}) is used in the design to spread the footprint of the x-ray beam. A box-cone-shape geometry was designed due to the limited space available in the front end. The box shape is a highly constrained geometry, which induces larger stress levels than would occur in a plate or a tube. In order to handle the expected higher stress and the stress concentration at the corners, a single Glidcop block (rather than copper) was used in the construction. The FM1 uses an enhanced heat transfer mechanism developed at Argonne National Laboratory, which increases the convective heat transfer coefficient to about 3 W/cm{sup 2}{center_dot}{degree}C with single-phase water as the coolant. The authors simulated the location of the x-ray beam in several places to cover the worst possible case. The maximum temperature (about 180{degree}C) occurs when the beam hits the center of horizontal surface. The maximum effective stress (about 313 MPa) occurs when the x-ray beam hits about the corners.

  11. Data mining based full ceramic bearing fault diagnostic system using AE sensors.

    PubMed

    He, David; Li, Ruoyu; Zhu, Junda; Zade, Mikhail

    2011-12-01

    Full ceramic bearings are considered the first step toward full ceramic, oil-free engines in the future. No research on full ceramic bearing fault diagnostics using acoustic emission (AE) sensors has been reported. Unlike their steel counterparts, signal processing methods to extract effective AE fault characteristic features and fault diagnostic systems for full ceramic bearings have not been developed. In this paper, a data mining based full ceramic bearing diagnostic system using AE based condition indicators (CIs) is presented. The system utilizes a new signal processing method based on Hilbert Huang transform to extract AE fault features for the computation of CIs. These CIs are used to build a data mining based fault classifier using a k-nearest neighbor algorithm. Seeded fault tests on full ceramic bearing outer race, inner race, balls, and cage are conducted on a bearing diagnostic test rig and AE burst data are collected. The effectiveness of the developed fault diagnostic system is validated using real full ceramic bearing seeded fault test data.

  12. Assimilation and implications of AE-9/AP-9 in the design process of JPL missions

    NASA Astrophysics Data System (ADS)

    de Soria-Santacruz Pich, M.; Jun, I.

    2015-12-01

    The NASA AE-8/AP-8 has been the standard geospace environment specification for decades. This model describes the energetic particle environment around the Earth and is currently the default model used in the design of space missions at the Jet Propulsion Laboratory (JPL). Moreover, the model plays a critical role in the determination of the shielding and survivability of the satellites orbiting our planet. A recent update supported by the Air Force Research Laboratory (AFRL) and the National Reconnaissance Office (NRO), the AE-9/AP-9 model, was released in September 2012 and included many improvements like increased spatial resolution and the specification of the uncertainty due to instrument errors or space weather variability. A current effort at JPL is in place with the objective of making a decision within the Laboratory on the transition from AE-8/AP-8 to the new AE-9/AP-9. In this study we present the results of this effort, which involves the comparison between both versions of the model for different satellite orbits, the comparison between AE-9/AP-9 and in-situ satellite data from the Van Allen Probes and the OSTM/Jason 2 satellite, and the implications of adopting the new model for spacecraft design in terms of survivability, shielding, single event effects, and spacecraft charging.

  13. MEASURING THE STELLAR ACCRETION RATES OF HERBIG Ae/Be STARS

    SciTech Connect

    Donehew, Brian; Brittain, Sean E-mail: sbritt@clemson.edu

    2011-02-15

    The accretion rate of young stars is a fundamental characteristic of these systems. While accretion onto T Tauri stars has been studied extensively, little work has been done on measuring the accretion rate of their intermediate-mass analogs, the Herbig Ae/Be stars. Measuring the stellar accretion rate of Herbig Ae/Bes is not straightforward both because of the dearth of metal absorption lines available for veiling measurements and the intrinsic brightness of Herbig Ae/Be stars at ultraviolet wavelengths where the brightness of the accretion shock peaks. Alternative approaches to measuring the accretion rate of young stars by measuring the luminosity of proxies such as the Br {gamma} emission line have not been calibrated. A promising approach is the measurement of the veiling of the Balmer discontinuity. We present measurements of this veiling as well as the luminosity of Br {gamma}. We show that the relationship between the luminosity of Br {gamma} and the stellar accretion rate for classical T Tauri stars is consistent with Herbig Ae stars but not Herbig Be stars. We discuss the implications of this finding for understanding the interaction of the star and disk for Herbig Ae/Be stars.

  14. Topology of the membrane domain of human erythrocyte anion exchange protein, AE1.

    PubMed

    Fujinaga, J; Tang, X B; Casey, J R

    1999-03-05

    Anion exchanger 1 (AE1) is the chloride/bicarbonate exchange protein of the erythrocyte membrane. By using a combination of introduced cysteine mutants and sulfhydryl-specific chemistry, we have mapped the topology of the human AE1 membrane domain. Twenty-seven single cysteines were introduced throughout the Leu708-Val911 region of human AE1, and these mutants were expressed by transient transfection of human embryonic kidney cells. On the basis of cysteine accessibility to membrane-permeant biotin maleimide and to membrane-impermeant lucifer yellow iodoacetamide, we have proposed a model for the topology of AE1 membrane domain. In this model, AE1 is composed of 13 typical transmembrane segments, and the Asp807-His834 region is membrane-embedded but does not have the usual alpha-helical conformation. To identify amino acids that are important for anion transport, we analyzed the anion exchange activity for all introduced cysteine mutants, using a whole cell fluorescence assay. We found that mutants G714C, S725C, and S731C have very low transport activity, implying that this region has a structurally and/or catalytically important role. We measured the residual anion transport activity after mutant treatment with the membrane-impermeant, cysteine-directed compound, sodium (2-sulfonatoethyl)methanethiosulfonate) (MTSES). Only two mutants, S852C and A858C, were inhibited by MTSES, indicating that these residues may be located in a pore-lining region.

  15. Characterization of the extremely arsenic-resistant Brevibacterium linens strain AE038-8 isolated from contaminated groundwater in Tucumán, Argentina

    USGS Publications Warehouse

    Maizel, Daniela; Blum, Jodi S.; Ferrero, Marcela A.; Utturkar, Sagar M.; Brown, Steven D.; Rosen, Barry P.; Oremland, Ronald S.

    2015-01-01

    Brevibacterium linens AE038-8, isolated from As-contaminated groundwater in Tucumán (Argentina), is highly resistant to arsenic oxyanions, being able to tolerate up to 1 M As(V) and 75 mM As(III) in a complex medium. Strain AE038-8 was also able to reduce As(V) to As(III) when grown in complex medium but paradoxically it could not do this in a defined minimal medium with sodium acetate and ammonium sulfate as carbon and nitrogen sources, respectively. No oxidation of As(III) to As(V) was observed under any conditions. Three copies of the ars operon comprising arsenic resistance genes were found on B. linens AE038-8 genome. In addition to the well known arsC, ACR3 andarsR, two copies of the arsO gene of unknown function were detected.

  16. Comparison of NASA Team2 and AES-York Ice Concentration Algorithms Against Operational Ice Charts From the Canadian Ice Service

    NASA Technical Reports Server (NTRS)

    Shokr, Mohammed; Markus, Thorsten

    2006-01-01

    Ice concentration retrieved from spaceborne passive-microwave observations is a prime input to operational sea-ice-monitoring programs, numerical weather prediction models, and global climate models. Atmospheric Environment Service (AES)- York and the Enhanced National Aeronautics and Space Administration Team (NT2) are two algorithms that calculate ice concentration from Special Sensor Microwave/Imager observations. This paper furnishes a comparison between ice concentrations (total, thin, and thick types) output from NT2 and AES-York algorithms against the corresponding estimates from the operational analysis of Radarsat images in the Canadian Ice Service (CIS). A new data fusion technique, which incorporates the actual sensor's footprint, was developed to facilitate this study. Results have shown that the NT2 and AES-York algorithms underestimate total ice concentration by 18.35% and 9.66% concentration counts on average, with 16.8% and 15.35% standard deviation, respectively. However, the retrieved concentrations of thin and thick ice are in much more discrepancy with the operational CIS estimates when either one of these two types dominates the viewing area. This is more likely to occur when the total ice concentration approaches 100%. If thin and thick ice types coexist in comparable concentrations, the algorithms' estimates agree with CIS'S estimates. In terms of ice concentration retrieval, thin ice is more problematic than thick ice. The concept of using a single tie point to represent a thin ice surface is not realistic and provides the largest error source for retrieval accuracy. While AES-York provides total ice concentration in slightly more agreement with CIS'S estimates, NT2 provides better agreement in retrieving thin and thick ice concentrations.

  17. Transmission of Ockelbo Virus by Aedes cinereus, Ae. communis, and Ae. excrucians (Diptera: Culicidae) Collected in an Enzootic Area in Central Sweden

    DTIC Science & Technology

    1989-01-01

    their legs.the jugular vein of each chick to determine its Number of refeeding mosquitoes transmitting/number re- viremia. Engorged mosquitoes were...identified and feeding (percentage transmitting); NA. none refeeding placed in cardboard containers with netting at one end. These cages were placed in an...incubator main- tained at 17"C (the average daily temperature dur- addition to these six refeeding mosquitoes, two Ae. ing the transmission season in

  18. Synthesis, Crystal and Electronic Structures of the Pnictides AE3TrPn3 (AE = Sr, Ba; Tr = Al, Ga; Pn = P, As)

    SciTech Connect

    Stoyko, Stanislav; Voss, Leonard; He, Hua; Bobev, Svilen

    2015-09-24

    New ternary arsenides AE3TrAs3 (AE = Sr, Ba; Tr = Al, Ga) and their phosphide analogs Sr3GaP3 and Ba3AlP3 have been prepared by reactions of the respective elements at high temperatures. Single-crystal X-ray diffraction studies reveal that Sr3AlAs3 and Ba3AlAs3 adopt the Ba3AlSb3-type structure (Pearson symbol oC56, space group Cmce, Z = 8). This structure is also realized for Sr3GaP3 and Ba3AlP3. Likewise, the compounds Sr3GaAs3 and Ba3GaAs3 crystallize with the Ba3GaSb3-type structure (Pearson symbol oP56, space group Pnma, Z = 8). Both structures are made up of isolated pairs of edge-shared AlPn4 and GaPn4 tetrahedra (Pn = pnictogen, i.e., P or As), separated by the alkaline-earth Sr2+ and Ba2+ cations. In both cases, there are no homoatomic bonds, hence, regardless of the slightly different atomic arrangements, both structures can be rationalized as valence-precise [AE2+]3[Tr3+][Pn3-]3, or rather [AE2+]6[Tr2Pn6]12-, i.e., as Zintl phases.

  19. Radiation Mechanisms and Physical Properties of GeV γ-Ray Source GB 1310+487

    NASA Astrophysics Data System (ADS)

    Yang, Jianping; Zhou, Bing

    2016-04-01

    With the adoption of the synchrotron self-Compton (SSC) + external Compton (EC) model, investigation has been conducted on the radiation mechanisms of the GeV-bright active galaxy GB 1310+487 through modeling its quasi-simultaneous spectral energy distributions in active and quiescent states. We find that from the flare states to the post-flare state, the magnetic field (B) has experienced a gradual increase, whereas the electron spectrum’s prefactor (N 0) and break energy ({γ }{br}) decrease accordingly. The model indicates that the energy of the Poynting flux may be used to accelerate electrons. As for the GeV emission in the source, it is dominated by the EC process while the SSC contribution is negligible. Varying energy distribution of the emitting electrons, rather than location of the radiation blob, appears to be the driving factor for the observed changes in EC emission. Despite the similar total jet power and the same likely energy carrier (cold protons), the radiation efficiency of GB 1310+487 is lower than what is found in bright Fermi blazars.

  20. Mechanisms for dose retention in conformal arsenic doping using a radial line slot antenna microwave plasma source

    NASA Astrophysics Data System (ADS)

    Ueda, Hirokazu; Ventzek, Peter L. G.; Oka, Masahiro; Kobayashi, Yuuki; Sugimoto, Yasuhiro

    2015-06-01

    Topographic structures such as Fin FETs and silicon nanowires for advanced gate fabrication require ultra-shallow high dose infusion of dopants into the silicon subsurface. Plasma doping meets this requirement by supplying a flux of inert ions and dopant radicals to the surface. However, the helium ion bombardment needed to infuse dopants into the fin surface can cause poor dose retention. This is due to the interaction between substrate damage and post doping process wet cleaning solutions required in the front end of line large-scale integration fabrication. We present findings from surface microscopy experiments that reveal the mechanism for dose retention in arsenic doped silicon fin samples using a microwave RLSA™ plasma source. Dilute aqueous hydrofluoric acid (DHF) cleans by themselves are incompatible with plasma doping processes because the films deposited over the dosed silicon and ion bombardment damaged silicon are readily removed. Oxidizing wet cleaning chemistries help retain the dose as silica rich over-layers are not significantly degraded. Furthermore, the dosed retention after a DHF clean following an oxidizing wet clean is unchanged. Still, the initial ion bombardment energy and flux are important. Large ion fluxes at energies below the sputter threshold and above the silicon damage threshold, before the silicon surface is covered by an amorphous mixed phase layer, allow for enhanced uptake of dopant into the silicon. The resulting dopant concentration is beyond the saturation limit of crystalline silicon.

  1. A perspective on 30 years of progress in ambient noise: Source mechanisms and the characteristics of the sound field

    NASA Astrophysics Data System (ADS)

    Cato, Douglas H.

    2012-11-01

    The last 30 years has seen substantial progress in ocean ambient noise research, particularly in understanding the mechanisms of sound generation by the sources of ambient noise, the way in which the noise field is affected by sound propagation, and improvements in quantifying the relationship between noise and environmental parameters. This has led to significant improvements in noise prediction. Activity was probably strongest in the 1980s and 1990s, as evident, for example, in the Sea Surface Sound conferences and their published proceedings (four over 10 years). Although much of the application has been to sonar, there has also been interest in using ambient noise to measure properties of the environment and in its significance to marine life. There have been significant changes in the ambient noise itself over the last 30 years. The contribution from human activities appears to have increased, particularly that due to increases in shipping numbers. Biological noise has also increased with the significant increases in populations of some whale species following the cessation of broad scale whaling in the 1960s and early 1970s. Concern about the effects of noise on marine animals as well as the way they exploit the noise has led to renewed interest in ambient noise.

  2. Study of the negative ion extraction mechanism from a double-ion plasma in negative ion sources

    SciTech Connect

    Goto, I.; Nishioka, S.; Hatayama, A.; Miyamoto, K.

    2015-04-08

    We have developed a 2D3V-PIC model of the extraction region, aiming to clarify the basic extraction mechanism of H{sup −} ions from the double-ion plasma in H{sup −} negative ion sources. The result shows the same tendency of the H{sup −} ion density n{sub H{sup −}} as that observed in the experiments, i.e.,n{sub H{sup −}} in the upstream region away from the plasma meniscus (H{sup −} emitting surface) has been reduced by applying the extraction voltage. At the same time, relatively slow temporal oscillation of the electric potential compared with the electron plasma frequency has been observed in the extraction region. Results of the systematic study using a 1D3V-PIC model with the uniform magnetic field confirm the result that the electrostatic oscillation is identified to be lower hybrid wave. The effect of this oscillation on the H{sup −} transport will be studied in the future.

  3. Source mechanism characterization and integrated interpretation of microseismic data monitoring two hydraulic stimulations in pouce coupe field, Alberta

    NASA Astrophysics Data System (ADS)

    Lindholm, Garrison J.

    The study of the Pouce Coupe Field is a joint effort between the Reservoir Characterization Project (RCP) and Talisman Energy Inc. My study focuses on the hydraulic stimulation of two horizontal wells within the Montney Formation located in north-western Alberta. The Montney is an example of a modern-day tight, engineering-driven play in which recent advances in drilling of horizontal wells and hydraulic fracturing have made shale gas exploitation economical. The wells were completed in December 2008 and were part of a science driven project in which a multitude of data were collected including multicomponent seismic, microseismic, and production logs. Since this time, a number of studies have been performed by students at Colorado School of Mines to better understand the effects the completions have had on the reservoir. This thesis utilizes the microseismic data that were recorded during the stimulation of the two horizontal wells in order to understand the origin of the microseismic events themselves. The data are then used to understand and correlate to the well production. To gain insight into the source of the microseismic events, amplitude ratios of recorded seismic modes (P, Sh and Sv) for the microseismic events are studied. By fitting trends of simple end member source mechanisms (strike-slip, dip-slip, and tensile) to groups of amplitude ratio data, the events are found to be of strike-slip nature. By comparing the focal mechanisms to other independent natural fracture determination techniques (shear-wave splitting analysis, FMI log), it is shown that the source of recorded microseismic events is likely to be a portion of the shear slip along existing weak planes (fractures) within a reservoir. The technique described in this work is one that is occasionally but increasingly used but offers the opportunity to draw further information from microseismic data using results that are already part of a typical processing workflow. The microseismic events are

  4. The use of MP-AES for analysis major and micronutrients in soils

    NASA Astrophysics Data System (ADS)

    Tonutare, Tonu; Rodima, Ako; Künnapas, Allan; Kõlli, Raimo; Albre, Imbi

    2016-04-01

    The ICP with OES or MS detectors is today the most common multielement technigues for soil element analysis. Although the micro-plasma has been available for decades, there were no commercially available instruments on the market. The situation changed in 2011 when the Agilent 4100 MP-AES appeared. The use of nitrogen plasma of the MP-AES provides reduction in the operational and maintenance costs compared to ICP and therefore makes it very perspective for soil analysis. The nitrogen microwave excited plasma has diferent properties compared to ICP argon plasma and this cause the specific behaviour of elements during the excitation. Here we present the results and optimal instrumental parameters for determination of soil nutrients (K, Ca, Mg, Fe and Zn) by MP-AES.

  5. Automated Estimating System (AES), Standard Value Update Program, user`s manual

    SciTech Connect

    Schwartz, R.K.; Holder, D.A.

    1994-08-01

    This manual contains instructions for operating the Standard Value Update Program. This program is operated and controlled by selected individuals in the Estimating and Scheduling Engineering Department of the Martin Marietta Energy Systems, Inc., Engineering Division. It is used to control and standardized input into the Automated Estimating System (AES) Estimating program, a person computer-based software package designed to aid in the creation, updating, and reporting of project cost estimates. The AES Estimating program is documented in a separate user`s manual.

  6. Phase-Space Density Analysis of the AE-8 Traped Electron and the AP-8 Trapped Proton Model Environments

    SciTech Connect

    Thomas E. Cayton

    2005-08-01

    The AE-8 trapped electron and the AP-8 trapped proton models are used to examine the L-shell variation of phase-space densities for sets of transverse (or 1st) invariants, {mu}, and geometrical invariants, K (related to the first two adiabatic invariants). The motivation for this study is twofold: first, to discover the functional dependence of the phase-space density upon the invariants; and, second, to explore the global structure of the radiation belts within this context. Variation due to particle rest mass is considered as well. The overall goal of this work is to provide a framework for analyzing energetic particle data collected by instruments on Global Positioning System (GPS) spacecraft that fly through the most intense region of the radiation belt. For all considered values of {mu} and K, and for 3.5 R{sub E} < L < 6.5 R{sub E}, the AE-8 electron phase-space density increases with increasing L; this trend--the expected one for a population diffusing inward from an external source--continues to L = 7.5 R{sub E} for both small and large values of K but reverses slightly for intermediate values of K. The AP-8 proton phase-space density exhibits {mu}-dependent local minima around L = 5 R{sub E}. Both AE-8 and AP-8 exhibit critical or cutoff values for the invariants beyond which the flux and therefore the phase-space density vanish. For both electrons and protons, these cutoff values vary systematically with magnetic moment and L-shell and are smaller than those estimated for the atmospheric loss cone. For large magnetic moments, for both electrons and protons, the K-dependence of the phase-space density is exponential, with maxima at the magnetic equator (K = 0) and vanishing beyond a cutoff value, K{sub c}. Such features suggest that momentum-dependent trapping boundaries, perhaps drift-type loss cones, serve as boundary conditions for trapped electrons as well as trapped protons.

  7. Phase-Space Density Analyses of the AE-8 Trapped Electron and the AP-8 Trapped Proton Model Environments

    SciTech Connect

    T.E. Cayton

    2005-08-12

    The AE-8 trapped electron and the AP-8 trapped proton models are used to examine the L-shell variation of phase-space densities for sets of transverse (or 1st) invariants, {mu}, and geometrical invariants, K (related to the first two adiabatic invariants). The motivation for this study is twofold: first, to discover the functional dependence of the phase-space density upon the invariants; and, second, to explore the global structure of the radiation belts within this context. Variation due to particle rest mass is considered as well. The overall goal of this work is to provide a framework for analyzing energetic particle data collected by instruments on Global Positioning System (GPS) spacecraft that fly through the most intense region of the radiation belt. For all considered values of {mu} and K, and for 3.5 R{sub E} < L < 6.5 R{sub E}, the AE-8 electron phase-space density increases with increasing L; this trend--the expected one for a population diffusing inward from an external source--continues to L = 7.5 R{sub E} for both small and large values of K but reverses slightly for intermediate values of K. The AP-8 proton phase-space density exhibits {mu}-dependent local minima around L = 5 R{sub E}. Both AE-8 and AP-8 exhibit critical or cutoff values for the invariants beyond which the flux and therefore the phase-space density vanish. For both electrons and protons, these cutoff values vary systematically with magnetic moment and L-shell and are smaller than those estimated for the atmospheric loss cone. For large magnetic moments, for both electrons and protons, the K-dependence of the phase-space density is exponential, with maxima at the magnetic equator (K = 0) and vanishing beyond a cutoff value, K{sub c}. Such features suggest that momentum-dependent trapping boundaries, perhaps drift-type loss cones, serve as boundary conditions for trapped electrons as well as trapped protons.

  8. GRG5/AES Interacts with T-Cell Factor 4 (TCF4) and Downregulates Wnt Signaling in Human Cells and Zebrafish Embryos

    PubMed Central

    Costa, Ângela M. Sousa; Pereira-Castro, Isabel; Ricardo, Elisabete; Spencer, Forrest; Fisher, Shannon; da Costa, Luís Teixeira

    2013-01-01

    Transcriptional control by TCF/LEF proteins is crucial in key developmental processes such as embryo polarity, tissue architecture and cell fate determination. TCFs associate with β-catenin to activate transcription in the presence of Wnt signaling, but in its absence act as repressors together with Groucho-family proteins (GRGs). TCF4 is critical in vertebrate intestinal epithelium, where TCF4-β-catenin complexes are necessary for the maintenance of a proliferative compartment, and their abnormal formation initiates tumorigenesis. However, the extent of TCF4-GRG complexes’ roles in development and the mechanisms by which they repress transcription are not completely understood. Here we characterize the interaction between TCF4 and GRG5/AES, a Groucho family member whose functional relationship with TCFs has been controversial. We map the core GRG interaction region in TCF4 to a 111-amino acid fragment and show that, in contrast to other GRGs, GRG5/AES-binding specifically depends on a 4-amino acid motif (LVPQ) present only in TCF3 and some TCF4 isoforms. We further demonstrate that GRG5/AES represses Wnt-mediated transcription both in human cells and zebrafish embryos. Importantly, we provide the first evidence of an inherent repressive function of GRG5/AES in dorsal-ventral patterning during early zebrafish embryogenesis. These results improve our understanding of TCF-GRG interactions, have significant implications for models of transcriptional repression by TCF-GRG complexes, and lay the groundwork for in depth direct assessment of the potential role of Groucho-family proteins in both normal and abnormal development. PMID:23840876

  9. Source mechanisms of earthquakes near mid-ocean ridges from body waveform inversion - Implications for the early evolution of oceanic lithosphere

    NASA Technical Reports Server (NTRS)

    Bergman, E. A.; Solomon, S. C.

    1984-01-01

    An evaluation is presented of the tectonics of the near-ridge environment based on the source mechanisms of earthquakes in young oceanic lithosphere. A catalog of near-ridge earthquakes is presented, and source parameters are determined from body waveform inversions. Source parameter-age relations are examined, and the near-ridge seismicity of the Indian Ocean is discussed. Deep normal faulting in young oceanic lithosphere is addressed, as is the relationship between thermoelastic stress and near-ridge earthquakes. The possibility of secondary convection beneath young oceanic lithosphere is considered. Finally, the broader tectonic implications of these results for the evolution of young oceanic lithosphere are discussed.

  10. The Mechanism of Microearthquakes Related to a Gas Storage Using Differently Constrained Source Models: A Case Study of the Háje Location, Czech Republic

    NASA Astrophysics Data System (ADS)

    Jechumtálová, Zuzana; Šílený, Jan; Málek, Jiří

    2017-01-01

    The resolution of a source mechanism is investigated in terms of three differently constrained source models: the moment tensor, the shear-tensile crack source model, and the double couple source model. The moment tensor (MT) is an unconstrained description of a general dipole source; the shear-tensile crack (STC) represents a slip along a fault with an off-plane component and the double couple (DC) corresponds to a simple shear slip along a fault. The inversion of body wave amplitudes is applied on microseismic events located in the vicinity of underground gas storage Háje (Czech Republic) where volume changes in the source can be expected. The orientation of the simple shear fracture component is resolved almost always well, independently of the source model used. On the other hand, the non-shear components differ largely among the source models considered, from both the model definition and robustness of the inversion. A comparison of the inversion results for the three alternative source models permits an assessment of the reliability of the non-shear components retrieved. Application of the STC model to all events appears to be the most appropriate. The analysis confirms a shear slip for three events and a tensile fracturing for other three events.

  11. Electric Eel-Skin-Inspired Mechanically Durable and Super-Stretchable Nanogenerator for Deformable Power Source and Fully Autonomous Conformable Electronic-Skin Applications.

    PubMed

    Lai, Ying-Chih; Deng, Jianan; Niu, Simiao; Peng, Wenbo; Wu, Changsheng; Liu, Ruiyuan; Wen, Zhen; Wang, Zhong Lin

    2016-12-01

    Electric eel-skin-inspired mechanically durable and super-stretchable nanogenerator is demonstrated for the first time by using triboelectric effect. This newly designed nanogenerator can produce electricity by touch or tapping despite under various extreme mechanical deformations or even after experiencing damage. This device can be used not only as deformable and wearable power source but also as fully autonomous and self-sufficient adaptive electronic skin system.

  12. Source Mechanisms and Stress Fields of the 15-16 June 2013 Crete Earthquake Sequence Along Hellenic Subduction Zone

    NASA Astrophysics Data System (ADS)

    Görgün, Ethem

    2017-03-01

    15 June 2013 M w 6.1 off-shore southern Crete earthquake and its aftershock sequence along Hellenic Subduction Zone are examined. Centroid moment tensors (CMTs) for 40 earthquakes with moment magnitudes ( M w) between 3.5 and 6.1 are determined by applying a waveform inversion method. The mainshock is shallow focus thrust event with a minor strike-slip component at a depth of 20 km. The seismic moment ( M o) of the mainshock is estimated as 2.07 × 1018 Nm, and rupture duration of the mainshock is 4 s. The focal mechanisms of aftershocks are mainly thrust faulting with a strike-slip component. The geometry of the moment tensors ( M w ≥ 3.5) reveals a thrust faulting regime with N-S trending direction of P axis in the entire activated region. According to high-resolution CMT solutions of the off-shore southern Crete earthquake sequence, one main cluster consisting of 40 events is revealed. The aftershock activity in the observation period between 15 June and 15 July 2013 extends from N to S and NW to SE directions. Seismic cross sections indicate a complex pattern of the hypocenter distribution with the activation of two segments. The subduction interface is clearly revealed with high-resolution hypocenter source relocation and moment tensor solution. The best-constrained focal depths indicate that the aftershock sequence is mainly confined in the upper plate (depth < 30 km) and is ranging from about 5-28 km depth. A stress tensor inversion of focal mechanism data is performed to obtain a more precise picture of the off-shore southern Crete stress field. The stress tensor inversion results indicate a predominant thrust stress regime with a NE-SW-oriented maximum horizontal compressive stress ( S H). According to variance of the stress tensor inversion, to first order, the southern Crete region is characterized by a homogeneous interplate stress field. We also investigate the Coulomb stress change associated with the mainshock to evaluate any significant

  13. Two sources of dayside intense, quasi-coherent plasmaspheric hiss: A new mechanism for the slot region?

    NASA Astrophysics Data System (ADS)

    Falkowski, Barbara J.; Tsurutani, Bruce T.; Lakhina, Gurbax S.; Pickett, Jolene S.

    2017-02-01

    A study of dayside plasmaspheric hiss at frequencies from 22 Hz to 1.0 kHz was carried out by using 1 year of Polar data. It is shown that intense, dayside plasmaspheric hiss is correlated with solar wind pressure with P > 2.5 nPa. The dayside effect is most prominent in the 300 to 650 Hz range. Intense dayside waves are also present during SYM-H < -5 nT. The latter is centered at local noon, with the greatest intensities in the L = 2 to 3 region. Assuming drift of 25 keV electrons from midnight to the wave magnetic local time, plasmaspheric hiss is shown to be highly correlated with precursor AE* and SYM-H* indices, indicating that the hiss is associated with substorms and small injection events. Our hypothesis is that both sets of waves originate as outer zone (L = 6 to 10) chorus and then propagate into the plasmasphere. Fourteen high-intensity dayside plasmaspheric hiss events were analyzed to identify the wave k, polarization, and the degree of coherency. The waves are found to be obliquely propagating, elliptically polarized and quasi-coherent ( 0.5 to 0.8 correlation coefficient). It is hypothesized that the dayside plasmaspheric hiss is quasi-coherent because the chorus has been recently generated in the outer magnetosphere and have propagated directly into the plasmasphere. It is possible that the quasi-coherency of the dayside hiss at L = 2 to 3 may be an alternate explanation for the generation of the energetic particle slot region.

  14. RANKL in the osteolysis of AES total ankle replacement implants.

    PubMed

    Koivu, H; Mackiewicz, Z; Takakubo, Y; Trokovic, N; Pajarinen, J; Konttinen, Y T

    2012-09-01

    Peri-implant tissue reactions in failed total ankle replacement (TAR) are characterized by early developing peri-implant osteolysis. The hypothesis of the study was that this reaction is mediated by receptor activator of nuclear factor kappa B ligand (RANKL). Samples of peri-prosthetic tissues from failed TAR implants were stained for macrophages, RANKL, its receptor RANK and osteoprotegerin (OPG), and compared to control samples. The failed TAR implants were surrounded by implant capsule, synovial lining-like interface membrane or necrotic tissues. Infiltrating scavenger receptor I positive CD163(+) macrophages were frequent, in particular around necrotic soft tissues or bone sequestrate, and possibly in part formed due to ischemia and mechanical factors. In contrast, implant-derived wear debris was scanty. Still many RANK(+) macrophages were often seen in close contact with RANKL(+) mesenchymal cells, whereas OPG was mostly located at a distance in vascular endothelial cells. Foreign body giant cells were frequent. RANKL seems to stimulate locally accumulated CD163(+) RANK-expressing cells to fusion, which leads to the local formation of multinuclear foreign body giant cells (and probably of osteoclasts). Therefore, peri-implant osteolysis in early TAR implant failure seems to be caused by the RANKL-driven chronic foreign body inflammation directed against, not implant-derived particles, but against necrotic autologous tissues.

  15. Source Mechanism of Strombolian Explosions Determined From Moment Tensor Inversion of Very-long-period Data: Implications For Gas Transport Dynamics At Stromboli

    NASA Astrophysics Data System (ADS)

    Chouet, B.; Dawson, P.; Saccorotti, G.; Martini, M.; de Luca, G.; Milana, G.; Scarpa, R.

    During September-October 1997, 21 broadband seismometers were deployed on Stromboli Volcano to investigate the source mechanism of Strombolian explosions. In the 2-50 s band, the very-long-period (VLP) signals associated with explosions are nearly linear and point to a source centroid located beneath the northwest flank of the volcano. To determine the source-centroid location and source mechanism we mini- mize the residual error between data and synthetics calculated by the finite-difference method for a point source embedded in a homogeneous elastic medium that takes to- pography into account. The observed waveforms are well reproduced by our inversion with a residual squared error of 5%. The source centroid that best fits the data is lo- cated at an elevation of 600 m, approximately 100 m below and 80 m northwest of the crater. The source mechanism includes both moment tensor and single force compo- nents. The principal axes of the moment tensor have amplitude ratios 1:1:2, which can be interpreted as representative of a crack if one assumes the rock matrix at the source to have a Poisson ratio nu = 1/3, which is an appropriate value for hot rock. The imaged crack dips 63^circ to the northwest and strikes northeast-southwest along a direction parallel to the major axis of the crater. The crack azimuth is consistent with the trends of exposed dikes and a known zone of weakness in the edifice. The volume change estimated from the moment is 200\\>{\\rm m^3} for the largest explosion. The source-time functions of the moment components display a characteristic se- quence of inflation-deflation-inflation of the source. The initial inflation phase is con- sistent with a pressurization of the dike associated with the formation and release of a slug of gas. A stronger deflation follows, which reflects mass ejection from the con- duit during the eruption. The next inflation represents the repressurization of the dike associated with the influx of liquid drawn into the

  16. Sterostreins A-E, new terpenoids from cultures of the Basidiomycete Stereum ostrea BCC 22955.

    PubMed

    Isaka, Masahiko; Srisanoh, Urarat; Choowong, Wilunda; Boonpratuang, Thitiya

    2011-09-16

    Sterostreins A-E (1, 2, 3a/3b, 4, and 5), five novel terpenoids, were isolated from cultures of the mushroom fungus Stereum ostrea BCC 22955. Sterostrein A (1) exhibited antimalarial activity (IC(50) 2.3 μg/mL) and cytotoxicity (IC(50) 5.3-38 μg/mL).

  17. The excess infrared emission of Herbig Ae/Be stars - Disks or envelopes?

    NASA Technical Reports Server (NTRS)

    Hartmann, Lee; Kenyon, Scott J.; Calvet, Nuria

    1993-01-01

    It is suggested that the near-IR emission in many Herbig Ae/Be stars arises in surrounding dusty envelopes, rather than circumstellar disks. It is shown that disks around Ae/Be stars are likely to remain optically thick at the required accretion rates. It is proposed that the IR excesses of many Ae/Be stars originate in surrounding dust nebulae instead of circumstellar disks. It is suggested that the near-IR emission of the envelope is enhanced by the same processes that produce anomalous strong continuum emission at temperatures of about 1000 K in reflection nebulae surrounding hot stars. This near-IR emission could be due to small grains transiently heated by UV photons. The dust envelopes could be associated with the primary star or a nearby companion star. Some Ae/Be stars show evidence for the 3.3-6.3-micron emission features seen in reflection nebulae around hot stars, which lends further support to this suggestion.

  18. Sputter-induced erosion of alkali metal surfaces - AES, XPS and SIMS studies

    SciTech Connect

    Krauss, A.R.

    1982-01-01

    This paper will discuss the manner in which the techniques of Auger-electron spectroscopy (AES), X-ray-photoelectron spectroscopy (XPS), secondary-ion mass spectroscopy (SIMS) and ion-scattering spectroscopy (ISS) may be used to study the use of high secondary-ion-yield surfaces as a means of reducing plasma-impurity influx in magnetic-confinement fusion devices.

  19. 15 CFR Appendix D to Part 30 - AES Filing Citation, Exemption and Exclusion Legends

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Exclusion Legends D Appendix D to Part 30 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade BUREAU OF THE CENSUS, DEPARTMENT OF COMMERCE FOREIGN TRADE REGULATIONS Pt. 30, App. D Appendix D to Part 30—AES Filing Citation, Exemption and Exclusion Legends I. USML Proof of Filing...

  20. 15 CFR Appendix D to Part 30 - AES Filing Citation, Exemption and Exclusion Legends

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Exclusion Legends D Appendix D to Part 30 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade BUREAU OF THE CENSUS, DEPARTMENT OF COMMERCE FOREIGN TRADE REGULATIONS Pt. 30, App. D Appendix D to Part 30—AES Filing Citation, Exemption and Exclusion Legends I. USML Proof of Filing...

  1. The B[e] Phenomenon in Pre-Main-Sequence Herbig Ae/Be Stars

    NASA Astrophysics Data System (ADS)

    Oudmaijer, R. D.

    2017-02-01

    In this review I describe the intermediate mass pre-main-sequence Herbig Ae/Be stars and their role in studies of star formation. They play a particularly important part in understanding the differences between the accretion of matter onto low and high mass stars. Once these differences are understood, further progress can be made in high mass star formation. Given that the B[e] phenomenon is a spectroscopic one, I will present recent developments in the spectroscopic studies of the Herbig Ae/Be stars, and then move to the [e] phenomenon in these object. Based on a large sample, it is found that forbidden lines are present for half of the Herbig Ae/Be stars, implying that the "[e]" phenomenon is widespread in Herbig Ae/Be stars. I will describe how the presence and properties of these lines can be used to our advantage in learning about their circumstellar environments, and their disks in particular. I conclude with a forward look.

  2. Vertical Transmission of Zika Virus by Aedes aegypti and Ae. albopictus Mosquitoes.

    PubMed

    Ciota, Alexander T; Bialosuknia, Sean M; Ehrbar, Dylan J; Kramer, Laura D

    2017-05-15

    To determine the potential role of vertical transmission in Zika virus expansion, we evaluated larval pools of perorally infected Aedes. aegypti and Ae. albopictus adult female mosquitoes; ≈1/84 larvae tested were Zika virus-positive; and rates varied among mosquito populations. Thus, vertical transmission may play a role in Zika virus spread and maintenance.

  3. Production and Perception of the English /ae/-/?/ Contrast in Switched-Dominance Speakers

    ERIC Educational Resources Information Center

    Casillas, Joseph V.; Simonet, Miquel

    2016-01-01

    This study investigates how fluent second-language (L2) learners of English produce and perceive the /ae/-/?/ vowel contrast of Southwestern American English. Two learner groups are examined: (1) early, proficient English speakers who were raised by Spanish-speaking families but who became dominant in English during childhood and, as adults, lack…

  4. 15 CFR Appendix D to Part 30 - AES Filing Citation, Exemption and Exclusion Legends

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 15 Commerce and Foreign Trade 1 2012-01-01 2012-01-01 false AES Filing Citation, Exemption and Exclusion Legends D Appendix D to Part 30 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade BUREAU OF THE CENSUS, DEPARTMENT OF COMMERCE FOREIGN TRADE REGULATIONS Pt. 30, App....

  5. 15 CFR Appendix D to Part 30 - AES Filing Citation, Exemption and Exclusion Legends

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 15 Commerce and Foreign Trade 1 2014-01-01 2014-01-01 false AES Filing Citation, Exemption and Exclusion Legends D Appendix D to Part 30 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade BUREAU OF THE CENSUS, DEPARTMENT OF COMMERCE FOREIGN TRADE REGULATIONS Pt. 30, App....

  6. Microstructure and Creep Behavior of High-Pressure Die-Cast Magnesium Alloy AE44

    NASA Astrophysics Data System (ADS)

    Zhu, S. M.; Nie, J. F.; Gibson, M. A.; Easton, M. A.; Bakke, P.

    2012-11-01

    The microstructure and creep behavior of a high-pressure die-cast AE44 (Mg-4Al-4RE) alloy have been studied. The creep properties were evaluated at 423 K and 448 K (150 °C and 175 °C) under stresses in the range 90 to 110 MPa. The microstructures before and after creep were examined by transmission electron microscopy (TEM). After creep, AE44 exhibits anomalously high stress exponents ( n = 67 at 423 K [150 °C] and n = 41 at 448 K [175 °C]) and stress-dependant activation energies ranging from 221 to 286 kJ/mol. The dislocation substructure developed during creep is characterized by extensive nonbasal slip and isolated but well-defined subgrain boundaries. It is shown that the anomalously high stress exponents cannot be rationalized by the threshold stress approach that is commonly adopted in analyzing the creep behavior of dispersion-strengthened alloys or metal matrix composites. A comparison in creep resistance is also made between AE44 and AE42 (Mg-4Al-2RE).

  7. Overcoming element quality dependence of finite elements with adaptive extended stencil FEM (AES-FEM)

    NASA Astrophysics Data System (ADS)

    Conley, Rebecca; Delaney, Tristan J.; Jiao, Xiangmin

    2016-11-01

    The finite element methods (FEM) are important techniques in engineering for solving partial differential equations, but they depend heavily on element shape quality for stability and good performance. In this paper, we introduce the Adaptive Extended Stencil Finite Element Method (AES-FEM) as a means for overcoming this dependence on element shape quality. Our method replaces the traditional basis functions with a set of generalized Lagrange polynomial (GLP) basis functions, which we construct using local weighted least-squares approximations. The method preserves the theoretical framework of FEM, and allows imposing essential boundary conditions and integrating the stiffness matrix in the same way as the classical FEM. In addition, AES-FEM can use higher-degree polynomial basis functions than the classical FEM, while virtually preserving the sparsity pattern of the stiffness matrix. We describe the formulation and implementation of AES-FEM, and analyze its consistency and stability. We present numerical experiments in both 2D and 3D for the Poison equation and a time-independent convection-diffusion equation. The numerical results demonstrate that AES-FEM is more accurate than linear FEM, is also more efficient than linear FEM in terms of error versus runtime, and enables much better stability and faster convergence of iterative solvers than linear FEM over poor-quality meshes

  8. Continuous AE crack monitoring of a dissimilar metal weldment at Limerick Unit 1

    SciTech Connect

    Hutton, P.H.; Friesel, M.A.; Dawson, J.F.

    1993-12-01

    Acoustic emission (AE) technology for continuous surveillance of a reactor component(s) to detect crack initiation and/or crack growth has been developed at Pacific Northwest Laboratory (PNL). The technology was validated off-reactor in several major tests, but it had not been validated by monitoring crack growth on an operating reactor system. A flaw indication was identified during normal inservice inspection of piping at Philadelphia Electric Company (PECO) Limerick Unit 1 reactor during the 1989 refueling outage. Evaluation of the flaw indication showed that it could remain in place during the subsequent fuel cycle without compromising safety. The existence of this flaw indication offered a long sought opportunity to validate AE surveillance to detect and evaluate crack growth during reactor operation. AE instrumentation was installed by PNL and PECO to monitor the flaw indication during two complete fuel cycles. This report discusses the results obtained from the AE monitoring over the period May 1989 to March 1992 (two fuel cycles).

  9. 75 FR 7209 - Airworthiness Directives; Rolls-Royce Corporation (RRC) AE 3007A Series Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-18

    ...: The FAA proposes to adopt a new airworthiness directive (AD) for RRC AE 3007A series turbofan engines. This proposed AD would require removing or performing initial and repetitive eddy current inspections... wheels for cracks. This proposed AD also reduces the approved life limits of certain HPT stage 2...

  10. The prevalence of weak magnetic fields in Herbig Ae stars: the case of PDS 2

    NASA Astrophysics Data System (ADS)

    Hubrig, S.; Carroll, T. A.; Schöller, M.; Ilyin, I.

    2015-04-01

    Models of magnetically driven accretion and outflows reproduce many observational properties of T Tauri stars, but the picture is much less clear for the Herbig Ae/Be stars, due to the poor knowledge of their magnetic field strength and topology. The Herbig Ae star PDS 2 was previously included in two magnetic studies based on low-resolution spectropolarimetric observations. Only in one of these studies the presence of a weak mean longitudinal magnetic field was reported. In the present study, for the first time, high-resolution high accuracy radial velocity planet searcher (HARPS) spectropolarimetric observations of PDS 2 are used to investigate the presence of a magnetic field. A firm detection of a weak longitudinal magnetic field is achieved using the multiline singular value decomposition method for Stokes profile reconstruction ( = 33 ± 5 G). To gain better knowledge of typical magnetic field strengths in late Herbig Be and Herbig Ae stars, we compiled previous magnetic field measurements, revealing that only very few stars have fields stronger than 200 G, and half of the sample possesses fields of about 100 G and less. These results challenge our current understanding of the magnetospheric accretion in intermediate-mass pre-main-sequence stars as they indicate that the magnetic fields in Herbig Ae/Be stars are by far weaker than those measured in T Tauri stars.

  11. 76 FR 4089 - Proposed Information Collection; Comment Request; Automated Export System (AES) Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-24

    ... basis for the official U.S. export trade statistics. These statistics are used to determine the balance... complete and accurate export statistics, as well as strengthening export controls. In spite of new filing... the Bureau of Industry and Security when valued over $2,500 per Schedule B. The AES program is...

  12. Investigation of Participation in Adult Education in Turkey: AES Data Analysis

    ERIC Educational Resources Information Center

    Dincer, N. Nergiz; Tekin-Koru, Ayca; Askar, Petek

    2016-01-01

    The aim of this study is to identify the determinants of participation in adult education in Turkey. The analysis is conducted using the Adult Education Survey (AES), conducted by TurkStat. The results indicate that economic growth in the sector of employment significantly and positively affects the odds for adult education participation. The data…

  13. Unseen but present danger: improving the safe prescribing of anti-embolism stockings (AES).

    PubMed

    Bradley, Alison

    2014-01-01

    A strong evidence base exists supporting thromboprophylaxis for venous thromboembolism (VTE) in surgical patients. Given the ageing population, obesity epidemic, and rise in type 2 diabetes, VTE and peripheral vascular disease (PAD) are likely to become an escalating problem. PAD is a contraindication to the use of anti-embolism stockings (AES). Half of those patients diagnosed with PAD report no symptoms, potentially underestimating its prevalence. Implementation of guidelines for thromboprophylaxis, including the safe prescribing of AES, is therefore imperative. The aims of this project were to establish whether thromboprophylaxis was being prescribed correctly, and appropriately, to all surgical inpatients. This included documented evidence that peripheral pulses had been examined - and, in the case of diabetic patients, that there was documentation of full peripheral neurovascular examination - before AES were prescribed. Data were collected from case notes of all surgical inpatients. Foundation year 1 doctors (FY1s) completed a questionnaire assessing their knowledge of local guidelines. Teaching sessions and posters summarising local guidelines were delivered to FY1s. Appropriate pharmacological prescribing improved from 57.69% to 100%. AES were appropriately prescribed for 65.38% of patients. Post intervention this increased to 79.17%. 0% had documented peripheral neurovascular examination. This increased to 50% post intervention.

  14. Source areas and transport mechanisms for freshwater and Brackish-water diatoms deposited in pelagic sediments of the equatorial atlantic*1

    NASA Astrophysics Data System (ADS)

    Pokras, Edward M.

    1991-01-01

    Distributions of freshwater and brackish-water diatoms from dust samples and modern sediments of the equatorial Atlantic demonstrate different transport mechanisms and source areas. Both Melosira spp. and Stephanodiscus spp. are transported via winds from the southern Sahara and Sahel in Northern Hemisphere winter. The core-top distribution of Cyclotella striata delineates the extent of the low-salinity plume formed by runoff from the Zaire River into the extreme eastern Atlantic. The transport mechanism and source areas for Melosira spp. during arid phases have not changed appreciably in the last 130,000 yr. There is no evidence for long-distance transport of freshwater diatoms by the southeast trade winds. This study confirms the validity of paleoclimatic research which inferred eolian transport of Melosira spp. in the winter dust plume from source regions north of the equator, although fluviatile input of Melosira valves into nearshore sediments cannot be ruled out.

  15. The relative importance and distribution of Aedes polynesiensis and Ae. aegypti larval habitats in Samoa.

    PubMed

    Samarawickrema, W A; Sone, F; Kimura, E; Self, L S; Cummings, R F; Paulson, G S

    1993-01-01

    In preparation for a Filariasis Control programme in Samoa, during 1978 monthly larval surveys of the vector mosquito Aedes polynesiensis were carried out in four study villages in the main island of Upolu. A more extensive survey of larval habitat distribution was then made in twenty-two villages of Upolu and eighteen of Savai'i island, to determine the importance of habitat types according to their abundance, volume of water and whether their productivity was permanent or seasonal. Ae.aegypti larval densities and habitat distribution were also monitored and the occurrence of predatory Toxorhynchites amboinensis larvae in northern Upolu was recorded from forty-one collections. Aedes Breteau and container indices fluctuated with the pattern of rainfall in two coastal villages and an inland bush village, but not in a coconut plantation community. The five main Aedes larval habitat types encountered were: 200 litre water-storage drums, discarded tins and bottles, coconut shells, automobile tyres and treeholes. Aedes immatures occurred perennially in drums and tree holes, but breeding discontinued in tins, bottles and coconut shells during the driest month of July. For Ae. polynesiensis in Upolu the Breteau and container indices of 104.5 +/- SD 80.9 and 35.3 +/- 12.4 respectively were significantly higher than those in Savai'i: 33.1 +/- 25.0 and 24.3 +/- 20.0 respectively. Likewise for Ae.aegypti the Breteau and container indices of 50.8 +/- 32.5 and 23.9 +/- 15.6, respectively, were also significantly higher than those in Savai'i: 12.7 +/- 17.1 and 9.4 +/- 13.2 respectively. Habitat types greater or lesser importance were determined by plotting the percentage of each type of cotnainer utilized for Aedes breeding against the percentage of ech type amongst all larva-positive containers. Ae.polynesiensis preferred tree-holes but not water-storage drums. Ae.aegypti preferred drums and tyres; mixed populations of larvae of both species were commonest in these two types of

  16. Improving the estimation of detection probability and magnitude of completeness in strongly heterogeneous media, an application to acoustic emission (AE)

    NASA Astrophysics Data System (ADS)

    Maghsoudi, Samira; Cesca, Simone; Hainzl, Sebastian; Kaiser, Diethelm; Becker, Dirk; Dahm, Torsten

    2013-06-01

    Reliable estimations of magnitude of completeness (Mc) are essential for a correct interpretation of seismic catalogues. The spatial distribution of Mc may be strongly variable and difficult to assess in mining environments, owing to the presence of galleries, cavities, fractured regions, porous media and different mineralogical bodies, as well as in consequence of inhomogeneous spatial distribution of the seismicity. We apply a 3-D modification of the probabilistic magnitude of completeness (PMC) method, which relies on the analysis of network detection capabilities. In our approach, the probability to detect an event depends on its magnitude, source-receiver Euclidian distance and source-receiver direction. The suggested method is proposed for study of the spatial distribution of the magnitude of completeness in a mining environment and here is applied to a 2-months acoustic emission (AE) data set recorded at the Morsleben salt mine, Germany. The dense seismic network and the large data set, which includes more than one million events, enable a detailed testing of the method. This method is proposed specifically for strongly heterogeneous media. Besides, it can also be used for specific network installations, with sensors with a sensitivity, dependent on the direction of the incoming wave (e.g. some piezoelectric sensors). In absence of strong heterogeneities, the standards PMC approach should be used. We show that the PMC estimations in mines strongly depend on the source-receiver direction, and cannot be correctly accounted using a standard PMC approach. However, results can be improved, when adopting the proposed 3-D modification of the PMC method. Our analysis of one central horizontal and vertical section yields a magnitude of completeness of about Mc ≈ 1 (AE magnitude) at the centre of the network, which increases up to Mc ≈ 4 at further distances outside the network; the best detection performance is estimated for a NNE-SSE elongated region, which

  17. A Comparison of Van Allen Belt Radiation Environment Modeling Programs: AE8/AP8 Legacy, AE9/AP9, and SPENVIS

    NASA Technical Reports Server (NTRS)

    Reed, Evan; Pellish, Jonathan

    2016-01-01

    In the space surrounding Earth there exists an active radiation environment consisting mostly of electrons and protons that have been trapped by Earths magnetic field. This radiation, also known as the Van Allen Belts, has the potential to damage man-made satellites in orbit; thus, proper precautions must be taken to shield NASA assets from this phenomenon. Data on the Van Allen Belts has been collected continuously by a multitude of space-based instruments since the beginning of space exploration. Subsequently, using theory to fill in the gaps in the collected data, computer models have been developed that take in the orbital information of a hypothetical mission and output the expected particle fluence and flux for that orbit. However, as new versions of the modeling system are released, users are left wondering how the new version differs from the old. Therefore, we performed a comparison of three different editions of the modeling system: AE8/AP8 (legacy), which is included in the model 9 graphical user interface as an option for ones calculations, AE9/AP9, and the Space Environment Information System (SPENVIS), which is an online-based form of AE8/AP8 developed by NASA and the European Space Agency that changed the code to allow the program to extrapolate data to predict fluence and flux at higher energies. Although this evaluation is still ongoing, it is predicted that the model 8 (legacy) and SPENVIS version will have identical outputs with the exception of the extended energy levels from SPENVIS, while model 9 will provide different fluences than model 8 based on additional magnetic field descriptions and on-orbit data.

  18. Anisotropic electrical and thermal conductivity in Bi2AE2Co2O8+δ [AE = Ca, Sr1-xBax (x = 0.0, 0.25, 0.5, 0.75, 1.0)] single crystals

    NASA Astrophysics Data System (ADS)

    Dong, Song-Tao; Zhang, Bin-Bin; Xiong, Ye; Lv, Yang-Yang; Yao, Shu-Hua; Chen, Y. B.; Zhou, Jian; Zhang, Shan-Tao; Chen, Yan-Feng

    2015-09-01

    Bi2AE2Co2O8+δ (AE represents alkaline earth), constructed by stacking of rock-salt Bi2AE2O4 and triangle CoO2 layers alternatively along c-axis, is one of promising thermoelectric oxides. The most impressive feature of Bi2AE2Co2O8+δ, as reported previously, is their electrical conductivity mainly lying along CoO2 plane, adjusting Bi2AE2O4 layer simultaneously manipulates both thermal conductivity and electrical conductivity. It in turn optimizes thermoelectric performance of these materials. In this work, we characterize the anisotropic thermal and electrical conductivity along both ab-plane and c-direction of Bi2AE2Co2O8+δ (AE = Ca, Sr, Ba, Sr1-xBax) single crystals. The results substantiate that isovalence replacement in Bi2AE2Co2O8+δ remarkably modifies their electrical property along ab-plane; while their thermal conductivity along ab-plane only has a slightly difference. At the same time, both the electrical conductivity and thermal conductivity along c-axis of these materials also have dramatic changes. Certainly, the electrical resistance along c-axis is too high to be used as thermoelectric applications. These results suggest that adjusting nano-block Bi2AE2O4 layer in Bi2AE2Co2O8+δ cannot modify the thermal conductivity along high electrical conductivity plane (ab-plane here). The evolution of electrical property is discussed by Anderson localization and electron-electron interaction U. And the modification of thermal conductivity along c-axis is attributed to the microstructure difference. This work sheds more light on the manipulation of the thermal and electrical conductivity in the layered thermoelectric materials.

  19. 77 FR 6471 - Bacillus thuringiensis Cry2Ae Protein in Cotton; Exemption from the Requirement of a Tolerance

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-08

    ... AGENCY 40 CFR Part 174 Bacillus thuringiensis Cry2Ae Protein in Cotton; Exemption from the Requirement of... regulation establishes an exemption from the requirement of a tolerance for residues of Bacillus... residues of Bacillus thuringiensis Cry2Ae protein in cotton under the FFDCA. DATES: This regulation...

  20. 40 CFR 174.530 - Bacillus thuringiensis Cry2Ae protein in cotton; temporary exemption from the requirement of a...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Bacillus thuringiensis Cry2Ae protein... REQUIREMENTS FOR PLANT-INCORPORATED PROTECTANTS Tolerances and Tolerance Exemptions § 174.530 Bacillus... Bacillus thuringiensis Cry2Ae protein in or on the food commodities of cotton, cotton; cotton,...

  1. 75 FR 70742 - AES Laurel Mountain, LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-18

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission AES Laurel Mountain, LLC; Supplemental Notice That Initial Market-Based Rate... notice in the above-referenced proceeding of AES Laurel Mountain, LLC's application for market-based...

  2. Production of Mucosally Transmissible SHIV Challenge Stocks from HIV-1 Circulating Recombinant Form 01_AE env Sequences.

    PubMed

    Tartaglia, Lawrence J; Chang, Hui-Wen; Lee, Benjamin C; Abbink, Peter; Ng'ang'a, David; Boyd, Michael; Lavine, Christy L; Lim, So-Yon; Sanisetty, Srisowmya; Whitney, James B; Seaman, Michael S; Rolland, Morgane; Tovanabutra, Sodsai; Ananworanich, Jintanat; Robb, Merlin L; Kim, Jerome H; Michael, Nelson L; Barouch, Dan H

    2016-02-01

    Simian-human immunodeficiency virus (SHIV) challenge stocks are critical for preclinical testing of vaccines, antibodies, and other interventions aimed to prevent HIV-1. A major unmet need for the field has been the lack of a SHIV challenge stock expressing circulating recombinant form 01_AE (CRF01_AE) env sequences. We therefore sought to develop mucosally transmissible SHIV challenge stocks containing HIV-1 CRF01_AE env derived from acutely HIV-1 infected individuals from Thailand. SHIV-AE6, SHIV-AE6RM, and SHIV-AE16 contained env sequences that were >99% identical to the original HIV-1 isolate and did not require in vivo passaging. These viruses exhibited CCR5 tropism and displayed a tier 2 neutralization phenotype. These challenge stocks efficiently infected rhesus monkeys by the intrarectal route, replicated to high levels during acute infection, and established chronic viremia in a subset of animals. SHIV-AE16 was titrated for use in single, high dose as well as repetitive, low dose intrarectal challenge studies. These SHIV challenge stocks should facilitate the preclinical evaluation of vaccines, monoclonal antibodies, and other interventions targeted at preventing HIV-1 CRF01_AE infection.

  3. 40 CFR 174.530 - Bacillus thuringiensis Cry2Ae protein in cotton; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... in cotton; exemption from the requirement of a tolerance. 174.530 Section 174.530 Protection of... Cry2Ae protein in cotton; exemption from the requirement of a tolerance. Residues of Bacillus thuringiensis Cry2Ae protein in or on the food and feed commodities of cotton; cotton, undelinted seed;...

  4. 40 CFR 174.530 - Bacillus thuringiensis Cry2Ae protein in cotton; temporary exemption from the requirement of a...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... in cotton; temporary exemption from the requirement of a tolerance. 174.530 Section 174.530... thuringiensis Cry2Ae protein in cotton; temporary exemption from the requirement of a tolerance. Residues of Bacillus thuringiensis Cry2Ae protein in or on the food commodities of cotton, cotton; cotton,...

  5. 40 CFR 174.530 - Bacillus thuringiensis Cry2Ae protein in cotton; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... in cotton; exemption from the requirement of a tolerance. 174.530 Section 174.530 Protection of... Cry2Ae protein in cotton; exemption from the requirement of a tolerance. Residues of Bacillus thuringiensis Cry2Ae protein in or on the food and feed commodities of cotton; cotton, undelinted seed;...

  6. 40 CFR 174.530 - Bacillus thuringiensis Cry2Ae protein in cotton; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... in cotton; exemption from the requirement of a tolerance. 174.530 Section 174.530 Protection of... Cry2Ae protein in cotton; exemption from the requirement of a tolerance. Residues of Bacillus thuringiensis Cry2Ae protein in or on the food and feed commodities of cotton; cotton, undelinted seed;...

  7. The Relationship between the Use of Health Clinics in Rural Mississippi Schools and the CHIP-AE Adolescent Health Profile

    ERIC Educational Resources Information Center

    Bradford, Judith Young; O'Sullivan, Patricia S.

    2007-01-01

    School health clinics are one way to meet the objectives in "Healthy People 2010" for adolescent health. To determine the relationship between adolescent health status and use of the school health clinics in four Mississippi high schools, the Child Health and Illness Profile-Adolescent Edition (CHIP-AE) was used. The CHIP-AE identifies…

  8. 42 CFR 84.153 - Airflow resistance test, Type A and Type AE supplied-air respirators; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Airflow resistance test, Type A and Type AE... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.153 Airflow resistance test, Type A and Type AE supplied-air respirators; minimum requirements. (a) Airflow resistance will...

  9. 42 CFR 84.153 - Airflow resistance test, Type A and Type AE supplied-air respirators; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Airflow resistance test, Type A and Type AE... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.153 Airflow resistance test, Type A and Type AE supplied-air respirators; minimum requirements. (a) Airflow resistance will...

  10. 42 CFR 84.153 - Airflow resistance test, Type A and Type AE supplied-air respirators; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Airflow resistance test, Type A and Type AE... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.153 Airflow resistance test, Type A and Type AE supplied-air respirators; minimum requirements. (a) Airflow resistance will...

  11. 42 CFR 84.153 - Airflow resistance test, Type A and Type AE supplied-air respirators; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Airflow resistance test, Type A and Type AE... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.153 Airflow resistance test, Type A and Type AE supplied-air respirators; minimum requirements. (a) Airflow resistance will...

  12. 42 CFR 84.153 - Airflow resistance test, Type A and Type AE supplied-air respirators; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Airflow resistance test, Type A and Type AE... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.153 Airflow resistance test, Type A and Type AE supplied-air respirators; minimum requirements. (a) Airflow resistance will...

  13. 77 FR 71189 - AES Beaver Valley, LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-29

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission AES Beaver Valley, LLC; Supplemental Notice That Initial Market- Based Rate...-referenced proceeding, of AES Beaver Valley, LLC's application for market-based rate authority, with...

  14. Characterization of Maize Amylose-Extender (ae) Mutant Starches. Part I: Relationship Between Resistant Starch Contents and Molecular Structures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Endosperm starches were isolated from kernels of seven maize amylose-extender (ae) lines. The resistant starch (RS) contents, measured using AOAC method 991.43, showed that three new ae-mutant starch lines developed by the USDA-ARS Germplasm Enhancement (GEM) and Truman State University had larger R...

  15. Influence of depth, focal mechanism, and tectonic setting on the shape and duration of earthquake source time functions

    NASA Astrophysics Data System (ADS)

    Houston, Heidi

    2001-06-01

    Source time functions of 255 moderate to great earthquakes obtained from inversions of teleseismic body waves by Tanioka and Ruff [1997] and coworkers were compared in a systematic way. They were scaled to remove the effect of moment and to allow the direct comparison and averaging of time function shape as well as duration. Time function durations picked by Tanioka and Ruff [1997] are proportional to the cube root of seismic moment if moments from the Harvard centroid moment tensor catalog are used. The average duration of scaled time functions is shorter and the average shape has a more abrupt termination for deeper events than shallower ones, with a distinct change occurring at ˜40 km depth. The complexity of the time functions, as quantified by the number of subevents, appears to decrease below ˜40 km depth. Furthermore, among events shallower than 40 km, the average duration of scaled time functions is shorter, and their average shape has a more abrupt termination (1) for events with strike-slip focal mechanisms compared to thrust events and (2) for the few thrust events associated with an intraplate setting compared to the majority associated with an interplate (subduction) boundary. In each of these cases, events in more technically and seismically active settings have a longer duration and a more gradual termination. This can be interpreted in terms of lower stress drops and/or slower rupture velocities at active plate boundaries, suggesting that fault rheology depends on slip rate and may evolve as total fault slip accumulates. Furthermore, differences in average time function shape and duration associated with different subduction zones suggest that differences exist in the rheology on the plate boundaries at the various subduction zones. Supporting data table is available via Web browser or via Anonymous FTP from ftp://kosmos.agu.org, directory "append" (Username = "anonymous", Password = "guest"); subdirectories in the ftp site are arranged by paper

  16. HCO3−/Cl− Exchange Inactivation and Reactivation during Mouse Oocyte Meiosis Correlates with MEK/MAPK-Regulated Ae2 Plasma Membrane Localization

    PubMed Central

    Zhou, Chenxi; Tiberi, Mario; Liang, Binhui; Alper, Seth L.; Baltz, Jay M.

    2009-01-01

    Background Germinal Vesicle (GV) stage mouse oocytes in first meiotic prophase exhibit highly active HCO3−/Cl− exchange—a class of transport nearly ubiquitously involved in regulation of intracellular pH and cell volume. During meiosis, however, oocyte HCO3−/Cl− exchange becomes inactivated during first metaphase (MI), remains inactive in second metaphase (MII), and is reactivated only after egg activation. Previous work using pharmacological manipulations had indicated that activity of the MEK/MAPK signaling pathway was negatively correlated with HCO3−/Cl− exchange activity during meiosis. However, the mechanism by which the exchanger is inactivated during meiotic progression had not been determined, nor had the role of MEK/MAPK been directly established. Methodology/Principal Findings Expression of a constitutively active form of MEK (MAP kinase kinase), which prevented the normal downregulation of MAPK after egg activation, also prevented reactivation of HCO3−/Cl− exchange. Conversely, suppression of endogenous MAPK activity with dominant negative MEK activated the normally quiescent HCO3−/Cl− exchange in mature MII eggs. A GFP-tagged form of the HCO3−/Cl− exchanger isoform Ae2 (Slc4a2) was strongly expressed at the GV oocyte plasma membrane, but membrane localization decreased markedly during meiotic progression. A similar pattern for endogenous Ae2 was confirmed by immunocytochemistry. The loss of membrane-localized Ae2 appeared selective, since membrane localization of a GFP-tagged human dopamine D1 receptor did not change during meiotic maturation. Conclusions Direct manipulation of MAPK activity indicated that GFP-tagged Ae2 localization depended upon MAPK activity. Inactivation of HCO3−/Cl− exchange during the meiotic cell cycle may therefore reflect the loss of Ae2 from the oocyte plasma membrane, downstream of MEK/MAPK signaling. This identifies a novel role for MEK/MAPK-mediated cytostatic factor (CSF) activity during

  17. EUV flux variations with solar rotation observed during 1974-1976 from AE satellites C, D, and E

    NASA Technical Reports Server (NTRS)

    Hinteregger, H. E.; Bedo, D. E.; Manson, J. E.; Skillman, D. R.

    1976-01-01

    Solar EUV fluxes in the spectral range from 140 to 1850 A have been observed by spectrophotometers on the satellites AE-C, D, and E. Variations over the long period of one or two years cannot be verified quantitatively, as the observed small variations are of the same magnitude as possible variations of instrumental sensitivities and estimated uncertainties of absolute values from the rocket experiment which established the calibration of the AE-C instrument. Fortunately, no similar difficulty exists for the interpretation of observed EUV variations within smaller time periods up to that of a full solar rotation. Results from AE-C observations for many different wavelength groups for the year 1974 are shown by some detail and compared with some recent observations made by the AE-D and AE-E instruments.

  18. Realization and optimization of AES algorithm on the TMS320DM6446 based on DaVinci technology

    NASA Astrophysics Data System (ADS)

    Jia, Wen-bin; Xiao, Fu-hai

    2013-03-01

    The application of AES algorithm in the digital cinema system avoids video data to be illegal theft or malicious tampering, and solves its security problems. At the same time, in order to meet the requirements of the real-time, scene and transparent encryption of high-speed data streams of audio and video in the information security field, through the in-depth analysis of AES algorithm principle, based on the hardware platform of TMS320DM6446, with the software framework structure of DaVinci, this paper proposes the specific realization methods of AES algorithm in digital video system and its optimization solutions. The test results show digital movies encrypted by AES128 can not play normally, which ensures the security of digital movies. Through the comparison of the performance of AES128 algorithm before optimization and after, the correctness and validity of improved algorithm is verified.

  19. Temporal Chemical Variations during the Eruption Cycle at Crystal Geyser in Green River, Utah: Inverse Modeling of Fluid Sourcing and Implications to the Geyser Mechanism

    NASA Astrophysics Data System (ADS)

    Watson, Z. T.; Han, W. S.; Kampman, N.; Grundl, T.; Han, K.

    2014-12-01

    The most well-known example of a CO2-driven geyser is Crystal geyser in Green River, Utah. In situ monitoring of pressure and temperature and analysis of the elemental and isotopic composition of the emanating fluids has provided useful proxies for determining the geysering cycle, the source of water/CO2 and furthermore the physical constraints at depth which ultimately control the surficial expressions. Crystal geyser is the first geyser in the world which has been shown to go through repeated systematic chemical variations during its eruption cycle. The eruption cycle at Crystal geyser is comprised of 4 parts which follow the order of: minor eruption period (mEP), major eruption period (MEP), aftershock eruptions (Ae) and recharge period (R). Minor eruption periods are characterized by increasing specific conductivity (19.3 to 21.2 mS/cm), Na and Cl concentrations during the first half which plateau until the MEP. The beginning of the MEP denotes a sharp drop in temperature (17.4 to 16.8 ºC) Na, Cl, specific conductivity (21.2 to 18 mS/cm), and increasing concentrations of Fe, Sr, Ca, Mg and Mn. Downhole fluid sampling of the Entrada Sandstone and Navajo Sandstone provided 1 and 4 samples from the aquifers, respectively. The Entrada Sandstone in comparison to the deeper Navajo Sandstone has elevated concentrations of Sr and Fe and has lower concentrations of Na and Cl. Inverse modeling using the chemical characteristics of the Entrada Sandstone, Navajo Sandstone and brine was executed to determine the fractional inputs which comprise Crystal geyser's fluid. Variances in the fractional contribution are dependent on the depth of the sample chosen to be representative of the Navajo Sandstone because the concentration of Na and Cl, among other elements, changes over depth. During the mEP the Navajo Sandstone, Entrada Sandstone and brine supply 50-55%, 44-48% and 1-3% of the total fluid, respectively. During the MEP the Navajo Sandstone, Entrada Sandstone and brine

  20. [Quantitative surface analysis of Pt-Co, Cu-Au and Cu-Ag alloy films by XPS and AES].

    PubMed

    Li, Lian-Zhong; Zhuo, Shang-Jun; Shen, Ru-Xiang; Qian, Rong; Gao, Jie

    2013-11-01

    In order to improve the quantitative analysis accuracy of AES, We associated XPS with AES and studied the method to reduce the error of AES quantitative analysis, selected Pt-Co, Cu-Au and Cu-Ag binary alloy thin-films as the samples, used XPS to correct AES quantitative analysis results by changing the auger sensitivity factors to make their quantitative analysis results more similar. Then we verified the accuracy of the quantitative analysis of AES when using the revised sensitivity factors by other samples with different composition ratio, and the results showed that the corrected relative sensitivity factors can reduce the error in quantitative analysis of AES to less than 10%. Peak defining is difficult in the form of the integral spectrum of AES analysis since choosing the starting point and ending point when determining the characteristic auger peak intensity area with great uncertainty, and to make analysis easier, we also processed data in the form of the differential spectrum, made quantitative analysis on the basis of peak to peak height instead of peak area, corrected the relative sensitivity factors, and verified the accuracy of quantitative analysis by the other samples with different composition ratio. The result showed that the analytical error in quantitative analysis of AES reduced to less than 9%. It showed that the accuracy of AES quantitative analysis can be highly improved by the way of associating XPS with AES to correct the auger sensitivity factors since the matrix effects are taken into account. Good consistency was presented, proving the feasibility of this method.

  1. Source duration of stress and water-pressure induced seismicity derived from experimental analysis of P wave pulse width in granite

    NASA Astrophysics Data System (ADS)

    Masuda, K.

    2013-12-01

    Pulse widths of P waves in granite, measured in the laboratory, were analyzed to investigate source durations of rupture processes for water-pressure induced and stress-induced microseismicity. Much evidence suggests that fluids in the subsurface are intimately linked to faulting processes. Studies of seismicity induced by water injection are thus important for understanding the trigger mechanisms of earthquakes as well as for engineering applications such as hydraulic fracturing of rocks at depth for petroleum extraction. Determining the cause of seismic events is very important in seismology and engineering; however, water-pressure induced seismic events are difficult to distinguish from those induced by purely tectonic stress. To investigate this problem, we analyzed the waveforms of acoustic emissions (AEs) produced in the laboratory by both water-pressure induced and stress-induced microseismicity. We used a cylinder (50 mm in diameter and 100 mm in length) of medium-grained granite. We applied a differential stress of about 70% of fracture strength, to the rock sample under 40 MPa confining pressure and held it constant throughout the experiment. When the primary creep stage and acoustic emissions (AEs) caused by the initial loading had ceased, we injected distilled water into the bottom end of the sample at a constant pressure of 17 MPa until macroscopic fracture occurred. We analysed AE waveforms produced by stress-induced AEs which occurred before the water-injection and by water-pressure induced AEs which occurred after the water-injection. Pulse widths were measured from the waveform traces plotted from the digital data. To investigate the source duration of the rupture process, we estimated the pulse width at the source and normalized by event magnitude to obtain a scaled pulse width at the source. After the effects of event size and hypocentral distance were removed from observed pulse widths, the ratio of the scaled source durations of water

  2. Mechanical study of the Chartreuse Fold-and-Thrust Belt: relationships between fluids overpressure and decollement within the Toarcian source-rock

    NASA Astrophysics Data System (ADS)

    Berthelon, Josselin; Sassi, William; Burov, Evgueni

    2016-04-01

    Many source-rocks are shale and constitute potential detachment levels in Fold-and-Thrust Belts (FTB): the toarcian Schistes-Cartons in the French Chartreuse FTB for example. Their mechanical properties can change during their burial and thermal maturation, as for example when large amount of hydrocarbon fluids are generated. A structural reconstruction of the Chartreuse FTB geo-history places the Toarcian Formation as the major decollement horizon. In this work, a mechanical analysis integrating the fluids overpressuring development is proposed to discuss on the validity of the structural interpretation. At first, an analogue of the Chartreuse Toarcian Fm, the albanian Posidonia Schist, is documented as it can provide insights on its initial properties and composition of its kerogen content. Laboratory characterisation documents the vertical evolution of the mineralogical, geochemical and mechanical parameters of this potential decollement layer. These physical parameters (i.e. Total Organic Carbon (TOC), porosity/permeability relationship, friction coefficient) are used to address overpressure buildup in the frontal part of the Chartreuse FTB with TEMISFlow Arctem Basin modelling approach (Faille et al, 2014) and the structural emplacement of the Chartreuse thrust units using the FLAMAR thermo-mechanical model (Burov et al, 2014). The hydro-mechanical modeling results highlight the calendar, distribution and magnitude of the overpressure that developed within the source-rock in the footwall of a simple fault-bend fold structure localized in the frontal part of the Chartreuse FTB. Several key geological conditions are required to create an overpressure able to fracture the shale-rocks and induce a significant change in the rheological behaviour: high TOC, low permeability, favourable structural evolution. These models highlight the importance of modeling the impact of a diffuse natural hydraulic fracturing to explain fluids propagation toward the foreland within

  3. Discovery of non-radial pulsations in the spectroscopic binary Herbig Ae star RS Chamaeleontis

    NASA Astrophysics Data System (ADS)

    Böhm, T.; Zima, W.; Catala, C.; Alecian, E.; Pollard, K.; Wright, D.

    2009-04-01

    Context: To understand the origin of stellar activity in pre-main-sequence Herbig Ae/Be stars and to get a deeper insight into the interior of these enigmatic stars, the pulsational instability strip of Palla and Marconi is investigated. In this article we present a first discovery of non radial pulsations in the Herbig Ae spectroscopic binary star RS Cha. Aims: The goal of the present work is to detect non-radial pulsations in a Herbig Ae star for the first time directly by spectrographic means and to identify the largest amplitude pulsation modes. Methods: The spectroscopic binary Herbig Ae star RS Cha was monitored in quasi-continuous observations during 14 observing nights (Jan. 2006) at the 1 m Mt. John (New Zealand) telescope with the Hercules high-resolution echelle spectrograph. The cumulative exposure time on the star was 44 h, corresponding to 255 individual high-resolution echelle spectra with R = 45 000. Least-square deconvolved spectra (LSD) were obtained for each spectrum, representing the effective photospheric absorption profile modified by pulsations. Difference spectra were calculated by subtracting rotationally broadened artificial profiles, these residual spectra were analysed and non-radial pulsations detected. A subsequent analysis with two complementary methods, namely Fourier Parameter Fit (FPF) and Fourier 2D (F2D) has been performed and first constraints on the pulsation modes derived. Results: For the very first time, we discovered by direct observational means using high-resolution echelle spectroscopy, non-radial oscillations in a Herbig Ae star. In fact, both components of the spectroscopic binary are Herbig Ae stars and both show NRPs. The FPF method identified 2 modes for the primary component with (degree ℓ, azimuthal order m) couples ordered by decreasing probability: f1 = 21.11 d-1 with (ℓ, m) = (11, 11), (11, 9) or (10, 6) and f2 = 30.38 d-1 with (ℓ, m) = ( 10, 6) or (9, 5). The F2D analysis indicates for f1 a degree

  4. From one to three dimensions: corrugated ∞(1)[NiGe] ribbons as a building block in alkaline earth metal Ae/Ni/Ge phases with crystal structure and chemical bonding in AeNiGe (Ae = Mg, Sr, Ba).

    PubMed

    Hlukhyy, Viktor; Siggelkow, Lisa; Fässler, Thomas F

    2013-06-17

    The new equiatomic nickel germanides MgNiGe, SrNiGe, and BaNiGe have been synthesized from the elements in sealed tantalum tubes using a high-frequency furnace. The compounds were investigated by X-ray diffraction both on powders and single crystals. MgNiGe crystallizes with TiNiSi-type structure, space group Pnma, Z = 4, a = 6.4742(2) Å, b = 4.0716(1) Å, c = 6.9426(2) Å, wR2 = 0.033, 305 F(2) values, 20 variable parameters. SrNiGe and BaNiGe are isotypic and crystallize with anti-SnFCl-type structure (Z = 4, Pnma) with a = 5.727(1) Å, b = 4.174(1) Å, c = 11.400(3) Å, wR2 = 0.078, 354 F(2) values, 20 variable parameters for SrNiGe, and a = 5.969(4) Å, b = 4.195(1) Å, c = 11.993(5) Å, wR2 = 0.048, 393 F(2) values, 20 variable parameters for BaNiGe. The increase of the cation size leads to a reduction of the dimensionality of the [NiGe] polyanions. In the MgNiGe structure the nickel and germanium atoms build a ∞(3)[NiGe] network with magnesium atoms in the channels. In SrNiGe and BaNiGe the ∞(1)[NiGe] ribbons are separated by strontium/barium atoms, whereas in the known CaNiGe structure the ribbons are fused to two-dimmensional atom slabs. The crystal chemistry and chemical bonding in AeNiGe (Ae = Mg, Ca, Sr, Ba) are discussed. The experimental results are reconciled with electronic structure calculations performed using the tight-binding linear muffin-tin orbital (TB-LMTO-ASA) method.

  5. Functional characterization and modified rescue of novel AE1 mutation R730C associated with overhydrated cation leak stomatocytosis

    PubMed Central

    Stewart, Andrew K.; Kedar, Prabhakar S.; Shmukler, Boris E.; Vandorpe, David H.; Hsu, Ann; Glader, Bertil; Rivera, Alicia; Brugnara, Carlo

    2011-01-01

    We report the novel, heterozygous AE1 mutation R730C associated with dominant, overhydrated, cation leak stomatocytosis and well-compensated anemia. Parallel elevations of red blood cell cation leak and ouabain-sensitive Na+ efflux (pump activity) were apparently unaccompanied by increased erythroid cation channel-like activity, and defined ouabain-insensitive Na+ efflux pathways of nystatin-treated cells were reduced. Epitope-tagged AE1 R730C at the Xenopus laevis oocyte surface exhibited severely reduced Cl− transport insensitive to rescue by glycophorin A (GPA) coexpression or by methanethiosulfonate (MTS) treatment. AE1 mutant R730K preserved Cl− transport activity, but R730 substitution with I, E, or H inactivated Cl− transport. AE1 R730C expression substantially increased endogenous oocyte Na+-K+-ATPase-mediated 86Rb+ influx, but ouabain-insensitive flux was minimally increased and GPA-insensitive. The reduced AE1 R730C-mediated sulfate influx did not exhibit the wild-type pattern of stimulation by acidic extracellular pH (pHo) and, unexpectedly, was partially rescued by exposure to sodium 2-sulfonatoethyl methanethiosulfonate (MTSES) but not to 2-aminoethyl methanethiosulfonate hydrobromide (MTSEA) or 2-(trimethylammonium)ethyl methanethiosulfonate bromide (MTSET). AE1 R730E correspondingly exhibited acid pHo-stimulated sulfate uptake at rates exceeding those of wild-type AE1 and AE1 R730K, whereas mutants R730I and R730H were inactive and pHo insensitive. MTSES-treated oocytes expressing AE1 R730C and untreated oocytes expressing AE1 R730E also exhibited unprecedented stimulation of Cl− influx by acid pHo. Thus recombinant cation-leak stomatocytosis mutant AE1 R730C exhibits severely reduced anion transport unaccompanied by increased Rb+ and Li+ influxes. Selective rescue of acid pHo-stimulated sulfate uptake and conferral of acid pHo-stimulated Cl− influx, by AE1 R730E and MTSES-treated R730C, define residue R730 as critical to selectivity and

  6. An up-to-date instrumentation system for detection, location and characterization of AE signals

    NASA Astrophysics Data System (ADS)

    Belcredi, D.; Sala, A.; Tornelli, C.

    1988-11-01

    An acoustic emission data overseeing system (AEDOS) has been developed for detection, location, and multiparametrical analysis of AE events such as amplitude, rise time, duration, energy, and delay time. The equipment comprises three main sections: the 'in field part' to detect and condition the AE events; the 'front end' that collects all the signals, makes the first screening among the signals, and measures the main parameters of the events; and the 'computer' to set up the system, to store the data, to analyze and display parametric isthograms, graphics, and location maps, and to supply an easy menu driven interface to the operator. A detailed functional description including performance specification of the system is given.

  7. Localization and characterization of CYP76AE2 part of thapsigargin biosynthesis in Thapsia garganica.

    PubMed

    Andersen, Trine Bundgaard; Martinez-Swatson, Karen Agatha; Rasmussen, Silas Anselm; Boughton, Berin Alain; Jørgensen, Kirsten; Andersen-Ranberg, Johan; Nyberg, Nils; Christensen, Søren Brøgger; Simonsen, Henrik Toft

    2017-03-08

    The Mediterranean plant Thapsia garganica (dicot, Apiaceae), also known as Deadly carrot, produces the highly toxic compound thapsigargin. This compound is a potent inhibitor of the SERCA calcium pump in mammals, and is of industrial importance as the active moiety of the anticancer drug Mipsagargin, currently in clinical trials. Knowledge of thapsigargin in planta storage and biosynthesis has so far been limited. Here we present the putative second step in thapsigargin biosynthesis, by showing that the cytochrome P450 TgCYP76AE2, transiently expressed in Nicotiana benthamiana, converts epikunzeaol into epidihydrocostunolide. Furthermore, we show that thapsigargin is likely to be stored in secretory ducts in the roots. Transcripts from TgTPS2 (epikunzeaol synthase) and TgCYP76AE2 in roots were only found in the epithelial cells lining these secretory ducts. This emphasizes the involvement of these cells in the biosynthesis of thapsigargin. This study paves the way for the further studies of thapsigargin biosynthesis.

  8. BOREAS AES Five-Day Averaged Surface Meteorological and Upper Air Data

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Strub, Richard; Newcomer, Jeffrey A.

    2000-01-01

    The Canadian Atmospheric Environment Service (AES) provided BOREAS with hourly and daily surface meteorological data from 23 of the AES meteorological stations located across Canada and upper air data from 1 station at The Pas, Manitoba. Due to copyright restrictions on the full resolution surface meteorological data, this data set contains 5-day average values for the surface parameters. The upper air data are provided in their full resolution form. The 5-day averaging was performed in order to create a data set that could be publicly distributed at no cost. Temporally, the surface meteorological data cover the period of January 1975 to December 1996 and the upper air data cover the period of January 1961 to November 1996. The data are provided in tabular ASCII files, and are classified as AFM-staff data. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  9. [Application of kalman filtering based on wavelet transform in ICP-AES].

    PubMed

    Qin, Xia; Shen, Lan-sun

    2002-12-01

    Kalman filtering is a recursive algorithm, which has been proposed as an attractive alternative to correct overlapping interferences in ICP-AES. However, the noise in ICP-AES contaminates the signal arising from the analyte and hence limits the accuracy of kalman filtering. Wavelet transform is a powerful technique in signal denoising due to its multi-resolution characteristics. In this paper, first, the effect of noise on kalman filtering is discussed. Then we apply the wavelet-transform-based soft-thresholding as the pre-processing of kalman filtering. The simulation results show that the kalman filtering based on wavelet transform can effectively reduce the noise and increase the accuracy of the analysis.

  10. Application of AE techniques in the evaluation of rock anchor stability

    SciTech Connect

    Unal, E.; Hardy, H.R. Jr.

    1984-01-01

    The development of a testing facility for detailed evaluation of rock bolt behavior and the results of a series of tests carried out on expansion-type rock bolts are discussed. In developing the testing facility special emphasis was placed on the detailed monitoring of all rock bolt components, as well as the associated bolt tension and torque, and the acoustic emission (AE) generated during various stages of bolt testing. During the study various anchorage testing parameters were investigated, and a significant correlation was obtained between a number of these parameters and the observed AE. The results presented are based on a limited number of tests and a more detailed testing program is planned in the future.

  11. The AES advanced 60kW PV-diesel hybrid inverter

    SciTech Connect

    Wills, R.H.

    1997-12-31

    This paper presents the advances made in hybrid PV-Diesel power conversion under AES`s PVMaT 4A research contract. Assembly and servicing were simplified by combining advances in power electronics (higher power IGBTs, bonded fin heat sinks and a new proprietary IGBT driver board) into a single power block. The newly US manufactured inverter features locally designed magnetics, a 70% smaller floor space requirement and a flexible, expandable software control scheme based on a Visual Basic-based Windows interface and industry standard MODBUS SCADA communications. The prototype unit has been tested at Sandia National Labs and is about to be tested at NREL`s Rocky Flats Wind Test Site. Operating results for an AES hybrid inverter site in Belize are also presented.

  12. Effect of mechanical force, rotation and moving internal heat source on a two-temperature fiber-reinforced thermoelastic medium with two theories

    NASA Astrophysics Data System (ADS)

    Said, Samia M.; Othman, Mohamed I. A.

    2016-09-01

    In the present paper, the three-phase-lag model and Green-Naghdi theory without energy dissipation are used to study the effect of a mechanical force and a rotation on the wave propagation in a two-temperature fiber-reinforced thermoelastic problem for a medium with an internal heat source that is moving with a constant speed. The methodology applied here is the use of the normal mode analysis to solve the problem of a thermal shock problem to obtain the exact expressions of the displacement components, force stresses, thermal temperature, and conductivity temperature. Numerical results for the considered variables are given and illustrated graphically in the absence and presence of a rotation as well as a mechanical force. A comparison is made with the results in the context of the two theories in the absence and presence of a moving internal heat source.

  13. Source mechanism of May 24, 2013 Sea of Okhotsk deep earthquake (Mw8.3) estimated by broadband waveform modeling

    NASA Astrophysics Data System (ADS)

    Tsuboi, S.; Miyoshi, T.; Nakamura, T.; Obayashi, M.; Tono, Y.

    2013-12-01

    May 24, 2013 Sea of Okhotsk earthquake (Mw 8.3, depth 640km NEIC) is not only one of the largest events in this general region but also one of the largest deep earthquakes ever recorded. We apply the waveform inversion technique (Kikuchi & Kanamori, 1991) to obtain slip distribution in the source fault of this earthquake in the same manner as our previous work (Nakamura et al., 2010). We use 57 broadband seismograms of IRIS GSN seismic stations with epicentral distance between 30 and 90 degrees. The broadband original data are integrated into ground displacement and band-pass filtered in the frequency band 0.002-1 Hz. Assuming 1D velocity model and the fault size of 135 x 135 km (along strike and dip, respectively), we obtain source rupture model for both nodal planes with high dip angle (81 degree) and low dip angle (10 degree). In order to determine which source rupture model would explain the observations, we calculate broadband synthetic seismograms with these source models for a realistic 3D Earth model using the spectral-element method (Komatitsch & Tromp, 2001). We performed the simulations on 24,576 processors in 3072 nodes of the K-computer in RIKEN. We use a mesh with 200 million spectral-elements, for a total of 13 billion global integration grid points. This translates into an approximate grid spacing of 2.0 km along the Earth's surface. On this number of nodes, a simulation of 50 minutes of wave propagation accurate at periods of 4.5 seconds and longer requires about 5 hours of CPU time. The comparison of the synthetic waveforms with the observation shows that the source rupture model with the low dip angle fault plane better explains the observation especially at stations, which locate south of the epicenter. Our results indicate that the source rupture of this deep earthquake occurred along the horizontal fault plane inside the subducting pacific plate.

  14. Source Mechanism of May 30, 2015 Bonin Islands, Japan Deep Earthquake (Mw7.8) Estimated by Broadband Waveform Modeling

    NASA Astrophysics Data System (ADS)

    Tsuboi, S.; Nakamura, T.; Miyoshi, T.

    2015-12-01

    May 30, 2015 Bonin Islands, Japan earthquake (Mw 7.8, depth 679.9km GCMT) was one of the deepest earthquakes ever recorded. We apply the waveform inversion technique (Kikuchi & Kanamori, 1991) to obtain slip distribution in the source fault of this earthquake in the same manner as our previous work (Nakamura et al., 2010). We use 60 broadband seismograms of IRIS GSN seismic stations with epicentral distance between 30 and 90 degrees. The broadband original data are integrated into ground displacement and band-pass filtered in the frequency band 0.002-1 Hz. We use the velocity structure model IASP91 to calculate the wavefield near source and stations. We assume that the fault is squared with the length 50 km. We obtain source rupture model for both nodal planes with high dip angle (74 degree) and low dip angle (26 degree) and compare the synthetic seismograms with the observations to determine which source rupture model would explain the observations better. We calculate broadband synthetic seismograms with these source propagation models using the spectral-element method (Komatitsch & Tromp, 2001). We use new Earth Simulator system in JAMSTEC to compute synthetic seismograms using the spectral-element method. The simulations are performed on 7,776 processors, which require 1,944 nodes of the Earth Simulator. On this number of nodes, a simulation of 50 minutes of wave propagation accurate at periods of 3.8 seconds and longer requires about 5 hours of CPU time. Comparisons of the synthetic waveforms with the observation at teleseismic stations show that the arrival time of pP wave calculated for depth 679km matches well with the observation, which demonstrates that the earthquake really happened below the 660 km discontinuity. In our present forward simulations, the source rupture model with the low-angle fault dipping is likely to better explain the observations.

  15. Identifying sediment sources and delivery mechanisms using background level polycyclic aromatic hydrocarbons in the Waiapu River watershed, New Zealand

    NASA Astrophysics Data System (ADS)

    Thompson, C. E.; Nichols, E. G.; Johnson, G.; Blair, N. E.; Leithold, E. L.; Palmer, A. S.; Baisden, W. T.

    2009-12-01

    The significant contribution of small mountainous river systems to the global fluvial sediment supply motivates investigation into the processes that influence the composition of the organic carbon that they carry. Organic matter preserved in continental margin sediments originates from terrestrial sources, such as kerogen and fresh and aged soil carbon, as well as marine sources. The identification of specific terrestrial fractions buried can facilitate interpretation of the organic geochemical record and enable reconstruction of watershed history. Carbon isotopic analyses have been used to apportion terrestrial carbon fractions preserved in marine environments; however, they have been generally limited to resolving modern C and kerogen. In this study, the use of polycyclic aromatic hydrocarbons (PAHs) to examine sediment production in the Waiapu watershed, New Zealand has been investigated. A suite of 42 alkylated and non-alkylated PAH concentrations establish chemical fingerprints for likely terrestrial sources of organic matter feeding the river and margin. Principal component analysis reveals chemical similarity between source and sink based on the degree of weathering and the relative inputs of petrogenic and pyrogenic PAHs. The primary sources of terrestrial organic matter buried over recent history on the continental shelf are Cretaceous bedrock, raw riverbank soils, and pastoral topsoils. Polytopic vector analysis of marine sediment establishes PAH end-member profiles, allowing sedimentary carbon on the shelf to be apportioned to contributing sources. These end-member model profiles confirm the PCA results, corresponding to PAH fingerprints of potential terrestrial sources including (1) bedrock composed of ancient kerogen, (2) soils from riverbank profiles that are composed of mixtures of ancient, aged, and modern carbon, and (3) topsoils typically composed of modern carbon from plant or fire-derived organic matter. Resolution of these sources suggests

  16. Validation of the French version of the Acceptability E-scale (AES) for mental E-health systems.

    PubMed

    Micoulaud-Franchi, Jean-Arthur; Sauteraud, Alain; Olive, Jérôme; Sagaspe, Patricia; Bioulac, Stéphanie; Philip, Pierre

    2016-03-30

    Despite the increasing use of E-health systems for mental-health organizations, there is a lack of psychometric tools to evaluate their acceptability by patients with mental disorders. Thus, this study aimed to translate and validate a French version of the Acceptability E-scale (AES), a 6-item self-reported questionnaire that evaluates the extent to which patients find E-health systems acceptable. A forward-backward translation of the AES was performed. The psychometric properties of the French AES version, with construct validity, internal structural validity and external validity (Pearson's coefficient between AES scores and depression symptoms on the Beck Depression Inventory II) were analyzed. In a sample of 178 patients (mean age=46.51 years, SD=12.91 years), the validation process revealed satisfactory psychometric properties: factor analysis revealed two factors: "Satisfaction" (3 items) and "Usability" (3 items) and Cronbach's alpha was 0.7. No significant relation was found between AES scores and depression symptoms. The French version of the AES revealed a two-factor scale that differs from the original version. In line with the importance of acceptability in mental health and with a view to E-health systems for patients with mental disorders, the use of the AES in psychiatry may provide important information on acceptability (i.e., satisfaction and usability).

  17. Integrated Design for Marketing and Manufacturing team: An examination of LA-ICP-AES in a mobile configuration. Final report

    SciTech Connect

    Not Available

    1994-05-01

    The Department of Energy (DOE) has identified the need for field-deployable elemental analysis devices that are safer, faster, and less expensive than the fixed laboratory procedures now used to screen hazardous waste sites. As a response to this need, the Technology Integration Program (TIP) created a mobile, field-deployable laser ablation-inductively coupled plasma-atomic emission spectrometry (LA-ICP-AES) sampling and analysis prototype. Although the elemental. screening prototype has been successfully field-tested, continued marketing and technical development efforts are required to transfer LA-ICP-AES technology to the commercial sector. TIP established and supported a student research and design group called the Integrated Design for Marketing and Manufacturing (IDMM) team to advance the technology transfer of mobile, field-deployable LA-ICP-AES. The IDMM team developed a conceptual design (which is detailed in this report) for a mobile, field-deployable LA-ICP-AES sampling and analysis system, and reports the following findings: Mobile, field-deployable LA-ICP-AES is commercially viable. Eventual regulatory acceptance of field-deployable LA-ICP-AES, while not a simple process, is likely. Further refinement of certain processes and components of LA-ICP-AES will enhance the device`s sensitivity and accuracy.

  18. A Ribosomal Protein AgRPS3aE from Halophilic Aspergillus glaucus Confers Salt Tolerance in Heterologous Organisms

    PubMed Central

    Liang, Xilong; Liu, Yiling; Xie, Lixia; Liu, Xiaodan; Wei, Yi; Zhou, Xiaoyang; Zhang, Shihong

    2015-01-01

    High salt in soils is one of the abiotic stresses that significantly reduces crop yield, although saline lands are considered potential resources arable for agriculture. Currently, genetic engineering for enhancing salt tolerance is being tested as an efficient and viable strategy for crop improvement. We previously characterized a large subunit of the ribosomal protein RPL44, which is involved in osmotic stress in the extremely halophilic fungus Aspergillus glaucus. Here, we screened another ribosomal protein (AgRPS3aE) that also produced high-salt tolerance in yeast. Bioinformatics analysis indicated that AgRPS3aE encodes a 29.2 kDa small subunit of a ribosomal protein belonging to the RPS3Ae family in eukaryotes. To further confirm its protective function against salinity, we expressed AgRPS3aE in three heterologous systems, the filamentous fungus Magnaporthe oryzae and two model plants Arabidopsis and tobacco. Overexpression of AgRPS3aE in all tested transformants significantly alleviated stress symptoms compared with controls, suggesting that AgRPS3aE functions not only in fungi but also in plants. Considering that ribosomal proteins are housekeeping components in organisms from prokaryotes to eukaryotes, we propose that AgRPS3aE is one of the optimal genes for improving high-salt tolerance in crops. PMID:25642759

  19. The stability of calibration standards for ICP/AES analysis: Six-month study

    SciTech Connect

    Huff, E.A.; Huff, D.R.

    1992-05-01

    The stability of instrument calibration standards for Inductively Coupled Plasma/Atomic Emission Spectrometric (ICP/AES) analysis was studied over a six-month period. Data were obtained as functions of analyte concentration, acid type, and acidity. The impact of acid concentration on signal-to-background ratios (S/B) was also assessed. The results show that analytes maintain their integrity over extended periods with appropriate inorganic acid preservatives. Thus, frequent standard preparations become unnecessary to obtain valid analytical data.

  20. [Correction of spectral interferences by ICP-AES primary expert system].

    PubMed

    Ying, H; Yang, P; Wang, X; Huang, B

    1998-12-01

    A subpackage for spectral interference correction has been set up in ICP-AES primary expert system. Some numerical recipes have been applied in this subpackage, such as curve smoothing, derivative spectrum, FFT technique, spectral resolving etc. A comprehensive method for spectral interference correction is presented. All these numeric recipes have been tested with simulated data and also utilized in several typical examples of real spectra. Results are satisfactory.

  1. [Determination of Ag, Cu, Zn and Cd in silver brazing filler metals by ICP-AES].

    PubMed

    Yang, X

    1997-06-01

    A method of simultaneous and direct determination for Ag, Cu, Zn and Cd in silver brazing filler metals by ICP-AES is reported. The spectral interferences and effect of acidity have been investigated. Working conditions were optimized. The method has been applied to the analysis of silver brazing filler metals with RSD of 4-7% and recovery of 94-105%. This method was accurate, simple and rapid.

  2. AE Ursae Majoris - a δ Scuti Star in the Hertzsprung Gap

    NASA Astrophysics Data System (ADS)

    Niu, Jia-Shu; Fu, Jian-Ning; Li, Yan; Yang, Xiao-Hu; Zong, Weikai; Xue, Hui-Fang; Zhang, Yan-Ping; Liu, Nian; Du, Bing; Zuo, Fang

    2017-01-01

    We analyze the photometric data and spectroscopic data that collect on the δ Scuti star AE UMa. The fundamental and the first overtone frequencies are confirmed as f0 = 11.62560 c d-1 and f1 = 15.03124 c d-1, respectively, from the frequency content by analyzing of the 40 nights light curve spanning from 2009 to 2012. Additionally, another 37 frequencies are identified as either the harmonics or the linear combinations of the fundamental and the first overtone frequencies, among which 25 are newly detected. The rate of period change of the fundamental mode is determined as (1/P0)(dP0/dt) = 5.4( ± 1.9) × 10-9 yr-1 as revealed from the O - C diagram based on the 84 newly determined times of maximum light combined with those derived from the literature. The spectroscopic data suggests that AE UMa is a population I δ Scuti star. With these physical properties, we perform theoretical explorations based on the stellar evolution code MESA on this target, considering that the variation of pulsation period is caused by secular evolutionary effects. We finally constraint the AE UMa with the physical parameters as: the mass of 1.805 ± 0.055 M⊙, the radius of 1.647 ± 0.032 × 1011 cm, the luminosity of 1.381 ± 0.048 (log L/L⊙) and the age of 1.055 ± 0.095 × 109 yr. AE UMa can be the (Pop. I) δ Scuti star that locates just after the second turn-off of its evolutional track leaving the main sequence, a star in the phase of the Hertzsprung Gap with a helium core and a hydrogen-burning shell.

  3. An adaptive technique for estimating the atmospheric density profile during the AE mission

    NASA Technical Reports Server (NTRS)

    Argentiero, P.

    1973-01-01

    A technique is presented for processing accelerometer data obtained during the AE missions in order to estimate the atmospheric density profile. A minimum variance, adaptive filter is utilized. The trajectory of the probe and probe parameters are in a consider mode where their estimates are unimproved but their associated uncertainties are permitted an impact on filter behavior. Simulations indicate that the technique is effective in estimating a density profile to within a few percentage points.

  4. AE9/AP9/SPM Radiation Environment Model: User’s Guide

    DTIC Science & Technology

    2014-02-18

    calculation results . Dose calculation results are also available. The GUI program ‘testAe9Ap9Gui.exe’ provides a graphical user interface to specify an...automatically generated according to the user’s selections in the interface. Basic 2D plots of the model results may also be produced. In addition to this...interface for producing mission statistics Aggregates results of many MC scenarios (flux, fluence, mean, percentiles) Provides access to orbit

  5. Accurate Simulation of Acoustic Emission Sources in Composite Plates

    NASA Technical Reports Server (NTRS)

    Prosser, W. H.; Gorman, M. R.

    1994-01-01

    Acoustic emission (AE) signals propagate as the extensional and flexural plate modes in thin composite plates and plate-like geometries such as shells, pipes, and tubes. The relative amplitude of the two modes depends on the directionality of the source motion. For source motions with large out-of-plane components such as delaminations or particle impact, the flexural or bending plate mode dominates the AE signal with only a small extensional mode detected. A signal from such a source is well simulated with the standard pencil lead break (Hsu-Neilsen source) on the surface of the plate. For other sources such as matrix cracking or fiber breakage in which the source motion is primarily in-plane, the resulting AE signal has a large extensional mode component with little or no flexural mode observed. Signals from these type sources can also be simulated with pencil lead breaks. However, the lead must be fractured on the edge of the plate to generate an in-plane source motion rather than on the surface of the plate. In many applications such as testing of pressure vessels and piping or aircraft structures, a free edge is either not available or not in a desired location for simulation of in-plane type sources. In this research, a method was developed which allows the simulation of AE signals with a predominant extensional mode component in composite plates requiring access to only the surface of the plate.

  6. Applications of high resolution ICP-AES in the nuclear industry

    SciTech Connect

    Johnson, S.G.; Giglio, J.J.; Goodall, P.S.; Cummings, D.G.

    1998-07-01

    Application of high resolution ICP-AES to selected problems of importance in the nuclear industry is a growing field. The advantages in sample preparation time, waste minimization and equipment cost are considerable. Two examples of these advantages are presented in this paper, burnup analysis of spent fuel and analysis of major uranium isotopes. The determination of burnup, an indicator of fuel cycle efficiency, has been accomplished by the determination of {sup 139}La by high resolution inductively coupled plasma atomic emission spectroscopy (HR-ICP-AES). Solutions of digested samples of reactor fuel rods were introduced into a shielded glovebox housing an inductively coupled plasma (ICP) and the resulting atomic emission transmitted to a high resolution spectrometer by a 31 meter fiber optic bundle. Total and isotopic U determination by thermal ionization mass spectrometry (TIMS) is presented to allow for the calculation of burnup for the samples. This method of burnup determination reduces the time, material, sample handling and waste generated associated with typical burnup determinations which require separation of lanthanum from the other fission products with high specific activities. Work concerning an alternative burnup indicator, {sup 236}U, is also presented for comparison. The determination of {sup 235}U:{sup 238}U isotope ratios in U-Zr fuel alloys is also presented to demonstrate the versatility of HR-ICP-AES.

  7. Monitoring of Surface Grinding process using Acoustic Emission (AE) with emphasis on Cutting Fluid selection

    NASA Astrophysics Data System (ADS)

    Nisal, Tejas V.

    Correct selection of cutting fluid is an important step in all machining operations. In this study, experiments were designed and conducted on AISI 52100 steel to determine the effects of using different cutting fluids in Surface Grinding. The grinding parameters varied were wheel speed, feed, depth of cut and type of cutting fluid. The grinding responses studied here were Acoustic Emission (AE) Signals, Normal and Tangential Forces on the workpiece surface, Grinding Temperature and Surface Roughness. Potential of Acoustic Emission technique as a tool to provide efficient real-time knowledge and monitoring of the grinding process, is tested in this research. AERMS values were used to analyses the process characteristics. This paper proposes four different statistical models for predicting Grinding Temperature, Force, Acoustic Emission (AERMS) and Roughness, based on grinding parameters. This research concludes that the selection of Cutting Fluids influence the Surface finish, AE signals, Temperature and grinding Forces measured. Further, prediction of surface roughness during the grinding process using AE signal monitoring is demonstrated in this work.

  8. ICP-AES determination of minor- and major elements in apples after microwave assisted digestion.

    PubMed

    Juranović Cindrić, Iva; Krizman, Ivona; Zeiner, Michaela; Kampić, Štefica; Medunić, Gordana; Stingeder, Gerhard

    2012-12-15

    The aim of this paper was to determine the content of minor and major elements in apples by inductively coupled plasma atomic emission spectrometry (ICP-AES). Prior to ICP-AES measurement, dried apples were digested in a microwave assisted digestion system. The differences in the measured element concentrations after application of open and closed microwave system as sample preparation procedures are discussed. In whole apples, flesh and peel Ag, Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Sr and Zn were analysed after optimisation and validating the analytical method using ICP-AES. The accuracy of the method determined by spiking experiments was very good (recoveries 88-115%) and the limits of detection of elements of interest were from 0.01 up to 14.7 μg g(-1). The reference ranges determined in all apple samples are 39-47 mg g(-1) for K, 9-14 mg g(-1) for Na, 3-7 mg g(-1) for Mg, 3-7 μg g(-1) for Zn, 0.7-2.8 μg g(-1) for Sr. The range of Mn in peel 4-6 μg g(-1) is higher compared to whole apple from 0.7 to 1.7 μg g(-1). Cd is found only in peel, in the concentration range of 0.4-1.1 μg g(-1).

  9. LINFLUX-AE: A Turbomachinery Aeroelastic Code Based on a 3-D Linearized Euler Solver

    NASA Technical Reports Server (NTRS)

    Reddy, T. S. R.; Bakhle, M. A.; Trudell, J. J.; Mehmed, O.; Stefko, G. L.

    2004-01-01

    This report describes the development and validation of LINFLUX-AE, a turbomachinery aeroelastic code based on the linearized unsteady 3-D Euler solver, LINFLUX. A helical fan with flat plate geometry is selected as the test case for numerical validation. The steady solution required by LINFLUX is obtained from the nonlinear Euler/Navier Stokes solver TURBO-AE. The report briefly describes the salient features of LINFLUX and the details of the aeroelastic extension. The aeroelastic formulation is based on a modal approach. An eigenvalue formulation is used for flutter analysis. The unsteady aerodynamic forces required for flutter are obtained by running LINFLUX for each mode, interblade phase angle and frequency of interest. The unsteady aerodynamic forces for forced response analysis are obtained from LINFLUX for the prescribed excitation, interblade phase angle, and frequency. The forced response amplitude is calculated from the modal summation of the generalized displacements. The unsteady pressures, work done per cycle, eigenvalues and forced response amplitudes obtained from LINFLUX are compared with those obtained from LINSUB, TURBO-AE, ASTROP2, and ANSYS.

  10. Reconstituting the epidemic history of mono lineage of HIV-1 CRF01_AE in Guizhou province, Southern China.

    PubMed

    Zeng, Haiyan; Sun, Binlian; Li, Lingnuo; Li, Yanpeng; Liu, Yong; Xiao, Yao; Jiang, Yan; Yang, Rongge

    2014-08-01

    Guizhou province, located between border provinces and Central province of China, plays a crucial role in the transmission of HIV-1, implying it is important to monitor the epidemic of HIV-1 in this region. Available HIV-1 infected patients' plasma (n=78) were collected from Tongren city, Eastern Guizhou. Full-length gag, partial pol and env gene sequences were amplified and analyzed using phylogenetic, recombinant and Bayesian molecular clock approaches. Phylogenetic and recombinant analyses showed that CRF01_AE predominated among injecting drug users and heterosexuals in Tongren city with 85.9% proportion, it was followed by B' (5.1%), CRF07_BC (3.8%), CRF08_BC (3.8%), and B (1.3%). Moreover, 98.5% of CRF01_AE strains belonged to the distinct lineage CRF01_AE-v previously found in Guangxi province. To infer the most probable origin of CRF01_AE-v in Guizhou province, we download all available full length of CRF01_AE gag, pol and env gene region sequences from China in Los Alamos HIV sequence database. Phylodynamic and phylogeographic analyses revealed that the expanding CRF01_AE-v epidemic in Guizhou province was the result of local epidemic driven by multiple independent introductions of CRF01_AE-v strains from Guangxi province in early 2000s. High prevalence of CRF01_AE in Guizhou province may bridge the epidemic to Central China. It provides a new insight for the understanding of HIV-1 epidemic in Guizhou province and makes the evolutionary history of CRF01_AE in China more intact.

  11. Composition of inner-source heavy pickup ions at 1 AU: SOHO/CELIAS/CTOF observations. Implications for the production mechanisms

    NASA Astrophysics Data System (ADS)

    Taut, A.; Berger, L.; Drews, C.; Wimmer-Schweingruber, R. F.

    2015-04-01

    Context. Pickup ions in the inner heliosphere mainly originate in two sources, one interstellar and one in the inner solar system. In contrast to the interstellar source that is comparatively well understood, the nature of the inner source has not been clearly identified. Former results obtained with the Solar Wind Ion Composition Spectrometer on-board the Ulysses spacecraft revealed that the composition of inner-source pickup ions is similar, but not equal, to the elemental solar-wind composition. These observations suffered from very low counting statistics of roughly one C+ count per day. Aims: Because the composition of inner-source pickup ions could lead to identifying their origin, we used data from the Charge-Time-Of-Flight sensor on-board the Solar and Heliospheric Observatory. It offers a large geometry factor that results in about 100 C+ counts per day combined with an excellent mass-per-charge resolution. These features enable a precise determination of the inner-source heavy pickup ion composition at 1 AU. To address the production mechanisms of inner-source pickup ions, we set up a toy model based on the production scenario involving the passage of solar-wind ions through thin dust grains to explain the observed deviations of the inner-source PUI and the elemental solar-wind composition. Methods: An in-flight calibration of the sensor allows identification of heavy pickup ions from pulse height analysis data by their mass-per-charge. A statistical analysis was performed to derive the inner-source heavy pickup ion relative abundances of N+, O+, Ne+, Mg+, Mg2+, and Si+ compared to C+. Results: Our results for the inner-source pickup ion composition are in good agreement with previous studies and confirm the deviations from the solar-wind composition. The large geometry factor of the Charge-Time-of-Flight sensor even allowed the abundance ratios of the two most prominent pickup ions, C+ and O+, to be investigated at varying solar-wind speeds. We found

  12. First-principles study of structural, electronic and magnetic properties of AeX (Ae=Be, Mg, Sr, Ba; X=Si, Ge and Sn) compounds

    NASA Astrophysics Data System (ADS)

    Jaiganesh, G.; Kalpana, G.

    2013-01-01

    The first-principles study of the electronic structure and ferromagnetism of AeX (Ae=Be, Mg, Sr and Ba; X=Si, Ge and Sn) compounds have been performed in the ground-state CrB-type and hypothetical NaCl- and zinc blende-type structures by spin-polarization and non-spin-polarization calculations. The TBLMTO-ASA program was used for the purpose. In the CrB-type structure, all these compounds exhibit non-magnetic and metallic behavior. The calculations show that in the NaCl- and ZB-type structures BeSi, BeGe, BeSn, MgSi, MgGe and MgSn compounds are non-magnets whereas SrSi, SrGe, SrSn, BaSi, BaGe and BaSn compounds are ferromagnetic and metallic. Apart from this the ZB-type SrSi, SrGe, BaSi and BaGe compounds exhibit half-metallicity at their equilibrium volume with a magnetic moment of 2.0 μB per formula unit. However, ZB-type SrSn and BaSn compounds are found to exhibit half-metallic property under expansion of volume. The magnetism arises mainly from the anion p-like states and partial involvement of cation d-like states. The ground state properties like equilibrium lattice parameters, bulk modulus, cohesive energy, magnetic moment, spin-flip-gap and majority spin band gap are calculated and compared with available results. The band structure and density of states are also presented. These materials will be useful for the study of p-electron magnetism and in spintronic devices.

  13. Flow sorting of C-genome chromosomes from wild relatives of wheat Aegilops markgrafii, Ae. triuncialis and Ae. cylindrica, and their molecular organization

    PubMed Central

    Molnár, István; Vrána, Jan; Farkas, András; Kubaláková, Marie; Cseh, András; Molnár-Láng, Márta; Doležel, Jaroslav

    2015-01-01

    Background and Aims Aegilops markgrafii (CC) and its natural hybrids Ae. triuncialis (UtUtCtCt) and Ae. cylindrica (DcDcCcCc) represent a rich reservoir of useful genes for improvement of bread wheat (Triticum aestivum), but the limited information available on their genome structure and the shortage of molecular (cyto-) genetic tools hamper the utilization of the extant genetic diversity. This study provides the complete karyotypes in the three species obtained after fluorescent in situ hybridization (FISH) with repetitive DNA probes, and evaluates the potential of flow cytometric chromosome sorting. Methods The flow karyotypes obtained after the analysis of 4',6-diamidino-2-phenylindole (DAPI)-stained chromosomes were characterized and the chromosome content of the peaks on the flow karyotypes was determined by FISH. Twenty-nine conserved orthologous set (COS) markers covering all seven wheat homoeologous chromosome groups were used for PCR with DNA amplified from flow-sorted chromosomes and genomic DNA. Key Results FISH with repetitive DNA probes revealed that chromosomes 4C, 5C, 7Ct, T6UtS.6UtL-5CtL, 1Cc and 5Dc could be sorted with purities ranging from 66 to 91 %, while the remaining chromosomes could be sorted in groups of 2–5. This identified a partial wheat–C-genome homology for group 4 and 5 chromosomes. In addition, 1C chromosomes were homologous with group 1 of wheat; a small segment from group 2 indicated 1C–2C rearrangement. An extensively rearranged structure of chromosome 7C relative to wheat was also detected. Conclusions The possibility of purifying Aegilops chromosomes provides an attractive opportunity to investigate the structure and evolution of the Aegilops C genome and to develop molecular tools to facilitate the identification of alien chromatin and support alien introgression breeding in bread wheat. PMID:26043745

  14. Optical and scintillation properties of Ce:(Gd8AE2)(SiO4)6O2 (AE = Mg, Ca, Sr and Ba) crystals

    NASA Astrophysics Data System (ADS)

    Igashira, Takuya; Mori, Masaki; Okada, Go; Kawaguchi, Noriaki; Yanagida, Takayuki

    2017-02-01

    1% Ce-doped and non-doped (Gd8AE2)(SiO4)6O2 (AE = Mg, Ca, Sr and Ba) (denoted as GMS, GCS, GSrS and GBS, respectively) single crystals were grown by the Floating Zone (FZ) method to evaluate their optical and scintillation properties. The Ce:GCS and Ce:GSrS samples exhibited scintillation and photoluminescence (PL) around 400 nm due to the 5d-4f transitions of Ce3+. On the other hand, Ce:GMS and Ce:GBS showed much weaker emissions in the wavelength range of 500-650 nm, in which the origin was associated with the host matrices. The PL decay curves were approximated by a double exponential decay function for all the Ce-doped samples. The decay times ranged around 10-30 and 40-90 ns, and faster components coincided with those of the non-doped samples. The scintillation decay curves of Ce-doped samples, on the other hand, were approximated by single exponential functions with slower decay constants than those of PL decay. These constants were very similar to those of non-doped samples. In the X-ray induced afterglow measurements, Ce:GCS exhibited the lowest afterglow level. The pulse height spectrum of these samples showed a full-energy peak under 241Am 5.5 MeV α-ray irradiation. Among these samples, Ce:GSrS exhibited the highest light yield which was around 600 ph/5.5 MeV-α.

  15. [Analysis of inorganic elements in hydroponic Taraxacum mongolicum grown under different spectrum combinations by ICP-AES].

    PubMed

    Chen, Xiao-li; Morewane, M B; Xue, Xu-zhang; Guo, Wen-zhong; Wang, Li-chun

    2015-02-01

    Dandelion (Taraxacum mongolicum) was hydroponically cultured in a completely enclosed plant factory, in which fluorescence and LED emitting spectra of different bands were used as the sole light source for plant growth. Effects of spectral component on the growth of dandelion were studied and the contents of ten inorganic elements such as K, P, Ca, Mg, Na, Fe, Mn, Zn, Cu and B in dandelion were analyzed by ICP-AES technology. The results showed that: (1) Under the condition of similar photosynthetic active radiation (PAR), single R or combined spectrums of FLRB were beneficial for biomass accumulation, while single B was the contrary; (2) Macroelements content ratio in Taraxacum mongolicum grown under FLwas K:Ca:P:Mg : Na=79.74:32.39:24.32:10.55:1.00, microelements content ratio was Fe:Mn:B:Zn:Cu = 9.28:9.71:3.82:2.08:1.00; (3) Red light (peak at 660 nm) could promote the absorptions of Ca, Fe, Mn, Zn, while absorption of Cu was not closely related to spectral conditions; (4) Thehighest accumulation of Ca, Na, Mn and Zn were obtained in aerial parts of Taraxacum mongolicum plants grown under pure red spectrum R, while the accumulation of the rest six elements reached the highest level under the mixed spectrum FLRB.

  16. Validation of the new trapped environment AE9/AP9/SPM at low Earth orbit

    NASA Astrophysics Data System (ADS)

    Badavi, Francis F.

    2014-09-01

    The completion of the international space station (ISS) in 2011 has provided the space research community an ideal proving ground for future long duration human activities in space. Ionizing radiation measurements in ISS form the ideal tool for the validation of radiation environmental models, nuclear transport codes and nuclear reaction cross sections. Indeed, prior measurements on the space transportation system (STS; shuttle) provided vital information impacting both the environmental models and the nuclear transport code developments by indicating the need for an improved dynamic model of the low Earth orbit (LEO) trapped environment. Additional studies using thermo-luminescent detector (TLD), tissue equivalent proportional counter (TEPC) area monitors, and computer aided design (CAD) model of earlier ISS configurations, confirmed STS observations that, as input, computational dosimetry requires an environmental model with dynamic and directional (anisotropic) behavior, as well as an accurate six degree of freedom (DOF) definition of the vehicle attitude and orientation along the orbit of ISS. At LEO, a vehicle encounters exposure from trapped particles and attenuated galactic cosmic rays (GCR). Within the trapped field, a challenge arises from properly estimating the amount of exposure acquired. There exist a number of models to define the intensities of the trapped particles during the solar quiet and active times. At active times, solar energetic particles (SEP) generated by solar flare or coronal mass ejection (CME) also contribute to the exposure at high northern and southern latitudes. Among the more established trapped models are the historic and popular AE8/AP8, dating back to the 1980s, the historic and less popular CRRES electron/proton, dating back to 1990s and the recently released AE9/AP9/SPM. The AE9/AP9/SPM model is a major improvement over the older AE8/AP8 and CRRES models. This model is derived from numerous measurements acquired over four

  17. Effect of sintering temperature on mechanical behaviour and bioactivity of sol-gel synthesized bioglass-ceramics using rice husk ash as a silica source

    NASA Astrophysics Data System (ADS)

    Nayak, J. P.; Bera, J.

    2010-11-01

    Bioglass-ceramics with SiO2-Na2O-CaO composition was prepared by sol-gel method using rice husk ash as a silica source. Material was sintered at different temperatures ranging from 900 to 1050 °C for 2 h. Phase-formation behaviour, densification characteristics, and mechanical strength of glass-ceramics were investigated. The material sintered at 1000 °C showed a good mechanical strength. Mechanical properties were correlated with microstructural features. Both in vitro bioactivity and biodegradability of sintered material were investigated by incubating in simulated body fluid and Tris buffer solution, respectively. Scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction were used to investigate the surface deposition during body fluid incubation. Both bioactivity and degradability decreased with increase in sintering temperature.

  18. The history of mass dispersal around Herbig Ae/Be stars

    NASA Astrophysics Data System (ADS)

    Fuente, A.; Martın-Pintado, J.; Bachiller, R.; Rodrıguez-Franco, A.; Palla, F.

    2002-06-01

    We present a systematic study of the material surrounding intermediate-mass stars. Our sample includes 34 Herbig Ae/Be (HAEBE) stars of different ages and luminosities. This is a quite complete representation of the whole class of HAEBE stars and consequently, our conclusions should have a solid statistical meaning. In addition, we have observed 2 intermediate-mass protostars and included published data on 15 protostellar objects in order to determine the evolution of the circumstellar material in the early stages of stellar evolution. All the HAEBE stars have been classified according with the three Types already defined in Fuente et al. (\\cite{fuen98}): Type I stars are immersed in a dense clump and have associated bipolar outflows, their ages are ~ 0.1 Myr; Type II stars are still immersed in the molecular cloud though not in a dense clump, their ages are between ~ a few 0.1 to ~ a few Myr; Type III stars have completely dispersed the surrounding material and are located in a cavity of the molecular cloud, their ages are >1 Myr. Our observations are used to reconstruct the evolution of the circumstellar material around intermediate-mass stars and investigate the mass dispersal mechanisms at the different stages of the stellar evolution. Our results can be summarized as follows: intermediate-mass stars disperse >=90% of the mass of the parent clump during the protostellar phase. During this phase, the energetic outflows sweep out the gas and dust forming a biconical cavity while the equatorial material is infalling to feed the circumstellar disk and eventually the protostar. In this way, the density structure of the parent clump remains well described by a density law n~ r\\beta with -2 =1 Myr. Since the outflow declines and the stars are still too cold to generate UV photons, stellar

  19. Differences in the Structure and Dynamics of the Apo- and Palmitate-ligated Forms of Aedes aegypti Sterol Carrier Protein 2 (AeSCP-2)*

    PubMed Central

    Singarapu, Kiran K.; Radek, James T.; Tonelli, Marco; Markley, John L.; Lan, Que

    2010-01-01

    Sterol carrier protein-2 (SCP-2) is a nonspecific lipid-binding protein expressed ubiquitously in most organisms. Knockdown of SCP-2 expression in mosquitoes has been shown to result in high mortality in developing adults and significantly lowered fertility. Thus, it is of interest to determine the structure of mosquito SCP-2 and to identify its mechanism of lipid binding. We report here high quality three-dimensional solution structures of SCP-2 from Aedes aegypti determined by NMR spectroscopy in its ligand-free state (AeSCP-2) and in complex with palmitate. Both structures have a similar mixed α/β fold consisting of a five-stranded β-sheet and four α-helices arranged on one side of the β-sheet. Ligand-free AeSCP-2 exhibited regions of structural heterogeneity, as evidenced by multiple two-dimensional 15N heteronuclear single-quantum coherence peaks for certain amino acids; this heterogeneity disappeared upon complex formation with palmitate. The binding of palmitate to AeSCP-2 was found to decrease the backbone mobility of the protein but not to alter its secondary structure. Complex formation is accompanied by chemical shift differences and a loss of mobility for residues in the loop between helix αI and strand βA. The structural differences between the αI and βA of the mosquito and the vertebrate SCP-2s may explain the differential specificity (insect versus vertebrate) of chemical inhibitors of the mosquito SCP-2. PMID:20356842

  20. IrAE – an asparaginyl endopeptidase (legumain) in the gut of the hard tick Ixodes ricinus

    PubMed Central

    Sojka, Daniel; Hajdušek, Ondřej; Dvořák, Jan; Sajid, Mohammed; Franta, Zdeněk; Schneider, Eric L.; Craik, Charles S.; Vancová, Marie; Burešová, Veronika; Bogyo, Matthew; Sexton, Kelly B.; McKerrow, James H.; Caffrey, Conor R.; Kopáček, Petr

    2008-01-01

    Ticks are ectoparasitic blood-feeders and important vectors for pathogens including arboviruses, rickettsiae, spirochetes and protozoa. As obligate blood-feeders, one possible strategy to retard disease transmission is disruption of the parasite’s ability to digest host proteins. However, the constituent peptidases in the parasite gut and their potential interplay in the digestion of the blood meal are poorly understood. We have characterized a novel asparaginyl endopeptidase (legumain) from the hard tick Ixodes ricinus (termed IrAE), which is the first such characterization of a clan CD family C13 cysteine peptidase (protease) in arthropods. By RT-PCR of different tissues, IrAE mRNA was only expressed in the tick gut. Indirect immunofluorescence and electron microscopy localized IrAE in the digestive vesicles of gut cells and within the peritrophic matrix. IrAE was functionally expressed in Pichia pastoris and reacted with a specific peptidyl fluorogenic substrate, and acyloxymethyl ketone and aza-asparagine Michael acceptor inhibitors. IrAE activity was unstable at pH ≥ 6.0 and was shown to have a strict specificity for asparagine at P1 using a positional scanning synthetic combinatorial library. The enzyme hydrolyzed protein substrates with a pH optimum of 4.5, consistent with the pH of gut cell digestive vesicles. Thus, IrAE cleaved the major protein of the blood meal, hemoglobin, to a predominant peptide of 4 kDa. Also, IrAE trans-processed and activated the zymogen form of Schistosoma mansoni cathepsin B1 – an enzyme contributing to hemoglobin digestion in the gut of that bloodfluke. The possible functions of IrAE in the gut digestive processes of I. ricinus are compared with those suggested for other hematophagous parasites. PMID:17336985

  1. The Epidemic Dynamics of Four Major Lineages of HIV-1 CRF01_AE Strains After Their Introduction into China.

    PubMed

    Zeng, Haiyan; Li, Tingting; Wang, Yan; Sun, Binlian; Yang, Rongge

    2016-05-01

    The epidemic of HIV-1 CRF01_AE in China was driven by multiple lineages of HIV-1 viruses introduced in the 1990s and increasing; it is important to investigate their epidemic status in China. In this study, we download all available CRF01_AE sequences (n = 2,931) from China and their associated epidemiological information in the Los Alamos HIV database for our analysis to explore their epidemic status in China. The results showed there were 11 distinct clusters of CRF01_AE strains in China, and 4 major clusters that accounted for 80.0% (1,793/2,241) of Chinese CRF01_AE strains in total had led a real epidemic. Clusters 1 and 2 were epidemic among heterosexuals and injecting drug users in southern and southwestern China, while Clusters 3 and 4 were predominant among homosexuals in eastern and central China and northeastern China, respectively. HIV-1 CRF01_AE strains detected in heterosexuals had the most complex characteristic, underscoring its important role in the occurrence of multiple CRF01_AE lineages. Furthermore, epidemic history reconstruction analysis using the birth-death susceptible-infected-removed package revealed that the four clusters had gone through varying epidemic stages. Clusters 2 and 3 were near the peak of the local epidemic, while Clusters 1 and 4 were just in the very early stage of their epidemic. The epidemic status of CRF01_AE clusters in the future is mainly determined by the effect of prevention and control. Our study provides new insights into the understanding of the epidemic dynamics of CRF01_AE in China.

  2. Small Scale Earthquake Mechanisms Induced by Fluid Injection at the Enhanced Geothermal System Reservoir Soultz (Alsace) in 2003 using Alternative Source Models

    NASA Astrophysics Data System (ADS)

    Šílený, Jan; Jechumtálová, Zuzana; Dorbath, Catherine

    2014-10-01

    The geothermal reservoir at Soultz-sous-Forêts is a valuable natural laboratory for understanding the mechanisms of microearthquakes generated during stimulations and circulation tests. An ongoing effort currently exists regarding the retrieval of mechanisms aimed to indicate the type of fracturing of the rock massif. As a default, a moment tensor description has been applied. Nevertheless, the retrieval of the mode of fracturing still remains ambiguous. Recent studies indicate a prevailing shear slip but, rarely, a non-shear pattern has also been observed. The moment tensor, used today as a universal tool for descriptions of the mechanism, captures general balanced dipole sources. However, in the case of small-scale earthquakes, the moment tensor need not always be reliably determined. In an effort to fit the data, there may be notable non-shear components caused by the low quality of input data. Constraining the source model to directly determine a simpler one is convenient for describing the physical phenomena expected for a particular focus. An opening of new fractures can be described, to a first approximation, by a tensile crack, optionally combined with a shear slip. Such an alternative model is called a shear-tensile crack (STC) source model. The combination is practical, and can be used to both identify events that reflect purely mode-I (tensile) failure and to determine the dilation angle of the fracture undergoing shear. The latter is particularly important in enhanced geothermal system reservoirs such as Soultz, where shear-related dilation is believed to be the primary mechanism underpinning permeability creation during stimulation injections. We performed a synthetic case study by simulating seismic data as recorded by the actual seismic array installed at Soultz-sous-Forêts. Synthetic P and S amplitudes for several shear-tensile source models were inverted for several types of station coverage. The analysis explored how results were influenced by

  3. Damage mechanisms of MoN/SiN multilayer optics for next-generation pulsed XUV light sources.

    PubMed

    Sobierajski, R; Bruijn, S; Khorsand, A R; Louis, E; van de Kruijs, R W E; Burian, T; Chalupsky, J; Cihelka, J; Gleeson, A; Grzonka, J; Gullikson, E M; Hajkova, V; Hau-Riege, S; Juha, L; Jurek, M; Klinger, D; Krzywinski, J; London, R; Pelka, J B; Płociński, T; Rasiński, M; Tiedtke, K; Toleikis, S; Vysin, L; Wabnitz, H; Bijkerk, F

    2011-01-03

    We investigated the damage mechanism of MoN/SiN multilayer XUV optics under two extreme conditions: thermal annealing and irradiation with single shot intense XUV pulses from the free-electron laser facility in Hamburg - FLASH. The damage was studied "post-mortem" by means of X-ray diffraction, interference-polarizing optical microscopy, atomic force microscopy, and scanning transmission electron microscopy. Although the timescale of the damage processes and the damage threshold temperatures were different (in the case of annealing it was the dissociation temperature of Mo2N and in the case of XUV irradiation it was the melting temperature of MoN) the main damage mechanism is very similar: molecular dissociation and the formation of N2, leading to bubbles inside the multilayer structure.

  4. Exploring the Physical, Chemical and Thermal Characteristics of a New Potentially Insensitive High Explosive: RX-55-AE-5

    SciTech Connect

    Weese, R K; Burnham, A K; Turner, H C; Tran, T D

    2006-06-05

    Current work at the Energetic Materials Center, EMC, at Lawrence Livermore National Laboratory (LLNL) includes both understanding properties of old explosives and measuring properties of new ones [1]. The necessity to know and understand the properties of energetic materials is driven by the need to improve performance and enhance stability to various stimuli, such as thermal, friction and impact insult. This review will concentrate on the physical properties of RX-55-AE-5, which is formulated from heterocyclic explosive, 2,6-diamino-3,5-dinitropyrazine-1-oxide, LLM-105, and 2.5% Viton A. Differential scanning calorimetry (DSC) was used to measure a specific heat capacity, C{sub p}, of {approx} 0.950 J/g{center_dot} C and a thermal conductivity, {kappa}, of {approx} 0.475 W/m{center_dot} C. The LLNL kinetics modeling code Kinetics05 and the Advanced Kinetics and Technology Solutions (AKTS) code Thermokinetics were both used to calculate Arrhenius kinetics for decomposition of LLM-105. Both obtained an activation energy barrier E {approx} 180 kJ mol{sup -1} for mass loss in an open pan. Thermal mechanical analysis, TMA, was used to measure the coefficient of thermal expansion (CTE). The CTE for this formulation was calculated to be {approx} 61 {micro}m/m{center_dot} C. Impact, spark, friction are also reported.

  5. Source of human ventilatory chaos: lessons from switching controlled mechanical ventilation to inspiratory pressure support in critically ill patients.

    PubMed

    Mangin, Laurence; Fiamma, Marie-Noëlle; Straus, Christian; Derenne, Jean-Philippe; Zelter, Marc; Clerici, Christine; Similowski, Thomas

    2008-04-30

    Ventilatory flow measured at the airway opening in humans exhibits a complex dynamics that has the features of chaos. Currently available data point to a neural origin of this feature, but the role of respiratory mechanics has not been specifically assessed. In this aim, we studied 17 critically ill mechanically ventilated patients during a switch form an entirely machine-controlled assistance mode (assist-controlled ventilation ACV) to a patient-driven mode (inspiratory pressure support IPS). Breath-by-breath respiratory variability was assessed with the coefficient of variation of tidal volume, total cycle time, inspiratory time, expiratory time, mean inspiratory flow, duty cycle. The detection of chaos was performed with the noise titration technique. When present, chaos was characterized with numerical indexes (correlation dimension, irregularity; largest Lyapunov exponent, sensitivity to initial conditions). Expectedly, the coefficients of variations of the respiratory variables were higher during IPS than during ACV. During ACV, noise titration failed to detect nonlinearities in 12 patients who did not exhibit signs of spontaneous respiratory activity. This indicates that the mechanical properties of the respiratory system were not sufficient to produce ventilatory chaos in the presence of a nonlinear command (ventilator clock). A positive noise limit was found in the remaining 5 cases, but these patients exhibited signs of active expiratory control (highly variable expiratory time, respiratory frequency higher than the set frequency). A positive noise limit was also observed in 16/17 patients during IPS (p<0.001). These observations suggest that ventilatory chaos predominantly has a neural origin (intrinsic to the respiratory central pattern generators, resulting from their perturbation by respiratory afferents, or both), with little contribution of respiratory mechanics, if any.

  6. Search for Gamma-Ray Emission from AE Aquarii with Seven Years of Fermi-LAT Observations

    NASA Astrophysics Data System (ADS)

    Li, Jian; Torres, Diego F.; Rea, Nanda; de Oña Wilhelmi, Emma; Papitto, Alessandro; Hou, Xian; Mauche, Christopher W.

    2016-11-01

    AE Aquarii (AE Aqr) is a cataclysmic binary hosting one of the fastest rotating ({P}{spin} = 33.08 s) white dwarfs (WDs) known. Based on seven years of Fermi Large Area Telescope (LAT) Pass 8 data, we report on a deep search for gamma-ray emission from AE Aqr. Using X-ray observations from ASCA, XMM-Newton, Chandra, Swift, Suzaku, and NuSTAR, spanning 20 years, we substantially extend and improve the spin ephemeris of AE Aqr. Using this ephemeris, we searched for gamma-ray pulsations at the spin period of the WD. No gamma-ray pulsations were detected above 3σ significance. Neither phase-averaged gamma-ray emission nor gamma-ray variability of AE Aqr is detected by Fermi LAT. We impose the most restrictive upper limit to the gamma-ray flux from AE Aqr to date: 1.3× {10}-12 erg cm-2 s-1 in the 100 MeV-300 GeV energy range, providing constraints on models.

  7. A near-realtime forecasting for the AE index during intervals with Interplanetary Alfvén Waves

    NASA Astrophysics Data System (ADS)

    Guarnieri, Fernando

    In recent years, Interplanetary Alfvén Waves have been shown as able to produce geomagnetic effects on Earth's magnetosphere, mainly visible in the AE index. These effects may last for several days (at least 2 days) and can reach very high AE peak values (more than 1000 nT), with enhanced AE average values occurring outside main phases of geomagnetic storms. Recently, Guarnieri (2005) and Guarnieri et al. (2007) have shown that it is possible to obtain high correlation coefficients between interplanetary Bz (obtained from ACE spacecraft) and AE index using a wavelet filtering method. This methodology allowed us to develop a set of equations to obtain the AE index based on the filtered Bz. An automated routine was developed to get the realtime Bz data from ACE and identify the presence of Alfvén waves. Once verified that these waves are present, the routine applies the wavelet filtering process. The Bz filtered time series is then shifted accordingly to the solar wind speed to take in to account the structure travel time from ACE to the Earth's magnetosphere. This shifted series is fed in to the equations to obtain the AE forecast. As soon as the preliminary tests were finished, the forecasting will be made available to the general public.

  8. Investigation of the high chromosphere model for source materials of solar cosmic rays and the mechanism for heavy-ion overabundance

    SciTech Connect

    Huang Yong-nian

    1988-10-01

    This paper calculates the temperature of the source material of energetic solar particles by using the average overabundance data of heavy ions in energetic solar-particle events, and proposes a new high chromosphere model to describe the source materials of energetic solar cosmic-ray particles. Solar flare observations showed that the flare acceleration region of the solar cosmic rays was most likely near the lower corona, and could be as high as several tens of thousands of kilometers. It is noted that the source and acceleration region for the solar cosmic rays are not located in the same region. A possible mechanism for heavy-ion overabundance in energetic solar-particle events is proposed. The source material is transported from the chromosphere to the active region by the frozen force-free field of the sun spots. This leads to a large abundance of heavy ions in the acceleration region ahead of the flare, and to overabundance of heavy elements in the cosmic rays behind the flare.

  9. One-dimensional array of point-like light sources based on gold nanoparticles and tetracene: Preparation and possible operation mechanisms

    SciTech Connect

    Cherepanov, V. V.; Fedorovich, R. D.; Kiyayev, O. E.; Naumovets, A. G.; Nechytaylo, V. B. Tomchuk, P. M.; Viduta, L. V.

    2014-11-10

    A method of preparation of a linear close-packed array of point-like light sources based on a nanocomposite of gold nanoparticles and tetracene is proposed. Ordered system of microleads to the light sources with packing density up to 1000 mm{sup −1} consists of linear conducting chains of cobalt nanoparticles self-assembled in a magnetic field. The electroluminescence from the gold-tetracene nanocomposite occurs in the visible range typical of organic light-emitting field-effect transistors based on tetracene. A theoretical substantiation of the possibility of excitation of tetracene molecules by hot electrons emitted from the gold nanoparticles is suggested and compared with other possible physical mechanisms.

  10. Activities and source mechanisms of volcanic deep low-frequency earthquakes and its implication for deep crustal process in magmatic arc (Invited)

    NASA Astrophysics Data System (ADS)

    Nakamichi, H.

    2013-12-01

    Rocks under upper mantle and lower crustal temperatures and pressures typically deform in a ductile manner, therefore it is difficult to accumulate enough deviatoric stress in rocks to generate brittle failure under this condition. However earthquakes occur at upper mantle and lower crust beneath active volcanoes, and are recognized as volcanic deep low-frequency earthquakes (VDLFs). VDLFs are characterized by mostly low-frequency energy (<5 Hz), emergent arrivals and long-duration codas. VDLF activity observed at depths of 10-50 km in Japan, the Philippines, Alaska and the Western US (Power et al., 2004; Ukawa, 2005; Nichols et al. 20011), has generally been attributed to magma transport in the mid-to-lower crustal and uppermost mantle regions. However because VDLF seismicity is infrequent, with relatively weak and emergent signals, the relationship between deep magma transport and seismic radiation remains poorly understood. Borehole dense seismic observation systems, such as the high-sensitivity seismograph network 'Hi-net' in Japan (Obara et al. 2005), are effective for detecting not only non-VDLFs (Obara, 2002) but also VDLFs. Since 1997 the Japan Meteorological Agency has routinely detected and located DLFs using the Hi-net dataset, and have identified DLFs in and around most quaternary volcanoes in Japan (Takahashi and Miyamura, 2009). Several studies have attempted to estimate source mechanisms of VDLFs in Japan. The first attempt by Ukawa and Ohtake (1987), obtained a single force as the source mechanism of a VDLF beneath Izu-Ohshima by using particle motions of S-waves. Following that work strike-slip type and non-double-couple source mechanisms were obtained using waveform inversions for VDLFs in Northeast Japan (Nishidomi and Takeo 1996; Okada and Hasegawa, 2000). Nakamichi et al. (2003; 2004) estimated the source mechanisms of Mts. Iwate and Fuji through the moment tensor inversion of spectral ratios of body waves from using data from a dense seismic

  11. Identify the injury implements by SEM/EDX and ICP-AES.

    PubMed

    Bai, Rufeng; Wan, Lihua; Li, Hongwei; Zhang, Zhong; Ma, Zhihua

    2007-02-14

    The forensic investigator is frequently confronted with the discrimination and deduction of injury implements, which is one of the most important physical testimonies in courts. The usual method used in actual cases is from points of morphology. In the forensic discrimination of injury implements, such as metal implements, the analysis and comparison of elements are expected to provide excellent results, and simultaneous multi-elemental analysis is required to analyze various kinds of elements. This study was designed to establish discrimination and deduction of metal injury implements by scanning electron microscope/energy disperse X-ray microanalyzer (SEM/EDX) and inductively coupled plasma atomic emission spectrometry (ICP-AES). Examined metal particles in five wounds made on the skin of domestic pigs, respectively, using Cu-Zn or Cr-Ni coated and carbon steel kitchen implements by EDX. For carbon steel kitchen implements, analyzed five samples from the back and blade separately in the contents and varieties of elements by ICP-AES. In the wounds by the coated implements, the special particles only containing Cu, Zn or Cr, Ni were found. In the wounds by carbon steel kitchen implements, the particles containing Fe, Cr, Si or Fe, Mn, Si were found. The differences of contents of elements between the back and blade was no significant except No. 5 for carbon steel kitchen implements, and the significant differences of elements exited in Cr, Mn, Si, Cu, Mo among the stainless kitchen knives, Mn, Si among the other kitchen implements and for the blade of No. 5 knife, relative standard deviations (R.S.D.s) were significantly different in Mn, Si, Mo, Ti, S, P, Ni. Using EDX to examine the particles in wounds can deduce the categories of metal injury implements, and we can still deduce the different implements in the same category by ICP-AES.

  12. Application of the discontinuous Galerkin method to study the source mechanisms for Love waves in ambient noise

    NASA Astrophysics Data System (ADS)

    Wenk, S.; Hadziioannou, C.; Igel, H.

    2012-12-01

    To produce detailed images of the crust using noise correlation studies and to understand the ocean - solid Earth interaction processes we investigate the behavior and distribution of ambient noise sources, especially focused on the relative contribution of Love waves to the ambient noise field. Therefore, we apply the discontinuous Galerkin (DG) method, which makes use of unstructured tetrahedral meshes combined with a time integration scheme solving the arbitrary high-order derivative (ADER) Riemann problem. The ADER-DG method is high-order accurate in space and time, beneficial for reliable simulations of high-frequency wavefields over long propagation distances. Due to the ease with which tetrahedral grids can be adapted to complex geometries, undulating topography of the Earth's surface and interior interfaces can be readily implemented in the computational domain.

  13. Thermo-mechanical analysis of the white-beam slits for an undulator beamline at the Advanced Photon Source

    SciTech Connect

    Nian, H.L.T.; Shu, D.; Kuzay, T.M.

    1994-09-01

    A set of precision horizontal and vertical white-beam slits has been designed for an undulator beamline at the Advanced Photon Source. Due to the powerful x-ray heat flux emitted by the undulator, it is difficult to control the thermal distortion within the desired range of 1-2 microns. We analyzed many conceptual designs in an attempt to minimize the thermal distortion of the slits. Even with 1-mm-thick, low-Z material (graphite) coated on the heating surface of a traditional slit, the maximum thermal distortion is over 25 microns. A three-piece slit was then designed to satisfy the requirements. It consists of one large block, two tungsten knife edges, and an OFHC cooling tube (filled with copper mesh) brazed inside the large block. The thermal distortion at the knife edges of this three-piece slit has a relative displacement of less than 2 microns.

  14. Handling of Highly Radioactive Radiation Sources in a Hot Cell Using a Mechanically Driven Cell Crane - 13452

    SciTech Connect

    Klute, Stefan; Huber, Wolfgang-Bruno

    2013-07-01

    In 2010, Siempelkamp Nukleartechnik GmbH was awarded the contract for design and erection of a Hot Cell for handling and storage of highly radioactive radiation sources. This Hot Cell is part of a new hot cell laboratory, constructed for the NHZ (Neues Handhabungszentrum = New Handling Center) of the Nuclear Engineering Seibersdorf GmbH (NES). All incurring radioactive materials from Austria are collected in the NHZ, where they are safely conditioned and stored temporarily until their final storage. The main tasks of the NES include, apart from the collection, conditioning and storage of radioactive waste, also the reprocessing and the decontamination of facilities and laboratories originating from 45 years of research and development at the Seibersdorf site as well as the operation of the Hot Cell Laboratory [1]. The new Hot Cell Laboratory inside the NHZ consists of the following room areas: - One hot cell, placed in the center, for remote controlled, radiation protected handling of radioactive materials, including an integrated floor storage for the long-term temporary storage of highly radioactive radiation sources; - An anteroom for the loading and unloading of the hot cell; - One control room for the remote controlling of the hot cell equipment; - One floor storage, placed laterally to the hot cell, for burial, interim storage and removal of fissionable radioactive material in leak-proof packed units in 100 l drums. The specific design activity of the hot cell of 1.85 Pbq relating to 1-Me-Radiator including the integrated floor storage influences realization and design of the components used in the cell significantly. (authors)

  15. ENDOCRINE DISRUPTERS: A REVIEW OF SOME SOURCES, EFFECTS, AND MECHANISMS OF ACTIONS ON BEHAVIOR AND NEUROENDOCRINE SYSTEMS

    PubMed Central

    Frye, C.; Bo, E.; Calamandrei, G.; Calzà, L.; Dessì-Fulgheri, F.; Fernández, M.; Fusani, L.; Kah, O.; Kajta, M.; Le Page, Y.; Patisaul, H.B.; Venerosi, A.; Wojtowicz, A.K.; Panzica, G.C.

    2011-01-01

    Some environmental contaminants interact with hormones and may exert adverse consequences due to their actions as endocrine disrupting chemicals (EDCs). Exposure in people is typically due to contamination of the food chain, inhalation of contaminated house dust, or occupational exposure. EDCs include pesticides and herbicides (such as diphenyl-dichloro-trichloroethane, DDT, or its metabolites), methoxychlor, biocides, heat stabilizers and chemical catalysts (such as tributyltin, TBT), plastic contaminants (e.g. bisphenol A, BPA), pharmaceuticals (i.e. diethylstilbestrol, DES; 17alpha-ethynilestradiol, EE2), or dietary components (such as phytoestrogens). The goal of this review is to address sources, effects and actions of EDCs, with an emphasis on topics discussed at the International Congress on Steroids and the Nervous System. EDCs may alter reproductively-relevant or non-reproductive, sexually-dimorphic behaviors. In addition, EDCs may have significant effects on neurodevelopmental processes, influencing morphology of sexually-dimorphic cerebral circuits. Exposure to EDCs is more dangerous if it occurs during specific “critical periods” of life, such as intrauterine, perinatal, juvenile or puberty periods, when organisms are more sensitive to hormonal disruption, than in other periods. However, exposure to EDCs in adulthood also can alter physiology. Several EDCs are xenoestrogens, may alter serum lipid concentrations, or metabolism enzymes that are necessary for converting cholesterol to steroid hormones, ultimately altering production of E2 and/or other steroids. Finally, many EDCs may have actions via, or independent of, classic actions at cognate steroid receptors. EDCs may have effects through numerous other substrates, such as the aryl hydrocarbon receptor (AhR), the peroxisome proliferator-activated receptor (PPAR) and retinoid X receptor (RXR), signal transduction pathways, calcium influx, and/or neurotransmitter receptors. Thus, EDCs, from varied

  16. [Determination of constant and trace elements in Ranunculus ternatus thunb by ICP-AES].

    PubMed

    Chen, Jun; Yao, Cheng; Ouyang, Ping-kai

    2005-04-01

    The determination of twenty one kinds of constant and trace elements in Chinese herb Ranunculus ternatus thunb was performed by ICP-AES. The results show that K, Fe, Ca, Cr, Mg, Mn, Zn, Co, Cu, Ni, Se and Sr are relatively rich in Ranunculus ternatus and the content of Pb, Cd and As are very low. The ratio of the content of Zn to that of Cu is about 3, which is consistent with the relative content level of Zn and Cu contained in many anticancer Chinese traditional plants.

  17. [Simultaneous determination of trace elements in mistletoe by ICP-AES].

    PubMed

    Li, Ti; Ni, Yong-Nian; Guo, Lan; Li, Li

    2008-05-01

    A method for the simultaneous determination of elements Cu, Mg, Zn, Mn, Ni, Se, K, Na, Ca and Fe in mistletoe after HNO3-H2O2 digestion by ICP-AES was studied. The recoveries obtained by standard addition method were between 90.8% and 112.8%, while the RSD (n = 5) was in the range of 0.47%-4.59%. The results showed that there were rich K, Ca, Mg and Na in the mistletoe, and offered scientific data for the ulterior study on mistletoe.

  18. Microcystbiopterins A-E, five O-methylated biopterin glycosides from two Microcystis spp. bloom biomasses.

    PubMed

    Lifshits, Marina; Kovalerchik, Dimitri; Carmeli, Shmuel

    2016-03-01

    Five previously undescribed biopterin glycosides, microcystbiopterin A-E, were isolated from the extracts of two bloom materials of Microcystis spp. collected from a fishpond (IL-337) and Lake Kinneret (IL-347), Israel. The structure of the pterins was established by interpretation of their UV, CD, 1D and 2D NMR spectra and HR mass measurements. Microcystbiopterin D is the first heptose containing pterin glycoside to be reported in the literature. Their antimicrobial and cytotoxic properties were evaluated but all were found not active in both assays.

  19. The Environment of the Optically Brightest Herbig Ae Star, HD 104237

    NASA Astrophysics Data System (ADS)

    Grady, C. A.; Woodgate, B.; Torres, Carlos A. O.; Henning, Th.; Apai, D.; Rodmann, J.; Wang, Hongchi; Stecklum, B.; Linz, H.; Williger, G. M.; Brown, A.; Wilkinson, E.; Harper, G. M.; Herczeg, G. J.; Danks, A.; Vieira, G. L.; Malumuth, E.; Collins, N. R.; Hill, R. S.

    2004-06-01

    We investigate the environment of the nearest Herbig Ae star, HD 104237, with a multiwavelength combination of optical coronagraphic, near-IR, and mid-IR imaging supported by optical, UV, and far-ultraviolet spectroscopy. We confirm the presence of T Tauri stars associated with the Herbig Ae star HD 104237, noted by Feigelson et al. We find that two of the stars within 15" of HD 104237 have IR excesses, potentially indicating the presence of circumstellar disks, in addition to the Herbig Ae star itself. We derive a new spectral type of A7.5Ve-A8Ve for HD 104237 and find log(L/Lsolar)=1.39. With these data, HD 104237 has an age of t~5 Myr, in agreement with the estimates for the other members of the association. HD 104237 is still actively accreting, with a conspicuous UV/far-UV excess seen down to 1040 Å, and is driving a bipolar microjet termed HH 669. This makes it the second, older Herbig Ae star now known to have a microjet. The presence of the microjet enables us to constrain the circumstellar disk to r<=0.6" (70 AU) with an inclination angle of i=18deg+14-11 from pole-on. The absence of a spatially extended continuum and fluorescent H2 emission near Lyα is in agreement with the prediction of shadowed disk models for the IR spectral energy distribution. With the high spatial density of disks in this group of stars, proximity, and minimal reddening, HD 104237 and its companions should serve as ideal laboratories for probing the comparative evolution of planetary systems. Based on observations made with the NASA/ESA Hubble Space Telescope, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA Contract NAS5-26555. Based on observations made with ESO's TIMMI2 camera on La Silla, Chile, under program ID 71.C-0438. Based on observations made with the ESO VLT and the Near-IR Adaptive Optics System+Conica, under program ID 71.C-0143. Based on observations made under the ON-ESO agreement for the joint operation of the 1.52 m

  20. Prediction of AU, AL, and AE indices using solar wind parameters

    NASA Astrophysics Data System (ADS)

    Luo, B.; Li, X.; Temerin, M. A.; Liu, S.

    2013-12-01

    An empirical model that predicts the AU index, a measure of the Earth's east electrojet, derived from magnetometers in the Northern hemisphere, is introduced. In addition, we have improved the previous AL model (Li et al., 2007) and have combined it with the AU model to produce an AE model. All models are based on upstream solar wind and interplanetary magnetic field parameters that have been propagated to the magnetopause by a simple ballistic propagation scheme for the years 1995 to 2001. The AU model predicts the 10-min averaged AU index for the seven years 1995-2001 with a prediction efficiency (PE) of 0.716, a linear correlation coefficient (LC) between the AU index and the model of 0.846, and a root mean square (RMS) error of 39.3 nT. We have updated the AL model introduced in Li et al. [2007] using the same prediction functions used to predict AU but with different parameters. The new AL model predicts the seven year AL index with a PE of 0.715, an LC of 0.846, and an RMS error of 81.6 nT. Using AE = AU-AL, the AE index is predicted with a PE of 0.788, an LC of 0.888, and an RMS error of 95.7 nT. The better PE and LC of the AE model over AU and AL models is because AU and AL are better correlated then their prediction errors. It is also found that: (1) The F10.7 index modulates the growth of auroral electrojet indices; (2) AU and AL behave differently during geomagnetic storm main phases. AU can drop to a low level while the magnitude of AL does not drop as much; (3) the longer-averaged auroral electrojets indices can be predicted very well but shorter timescale variations are much less predictable; (4) auroral electrojet activity is strongly dependent on the upstream solar wind velocity and the interplanetary magnetic field but is only weakly dependent on the solar wind density.

  1. The narrow, inner CO ring around the magnetic Herbig Ae star HD 101412

    NASA Astrophysics Data System (ADS)

    Cowley, C. R.; Hubrig, S.; Castelli, F.; Wolff, B.

    2012-01-01

    We describe and model emission lines in the first overtone band of CO in the magnetic Herbig Ae star HD 101412. High-resolution CRIRES spectra reveal unusually sharp features which suggest the emission is formed in a thin disk centered at 1 AU with a width 0.32 AU or less. A wider disk will not fit the observations. Previous observations have reached similar conclusions, but the crispness of the new material brings the emitting region into sharp focus. Based on observations obtained at the European Southern Observatory (ESO programme 087.C-0124(A)).

  2. Allimacrosides A-E, new steroidal glycosides from Allium macrostemon Bunge.

    PubMed

    Kim, Yun Sik; Suh, Won Se; Park, Kyoung Jin; Choi, Sang Un; Lee, Kang Ro

    2017-02-01

    A new pregnane-type steroidal glycoside (1), two new spirostane-type steroidal glycosides (2, 3), and two new furostane-type steroidal glycosides (4, 5), named allimacrosides A-E, together with four known compounds (6-9) were isolated from a 80% MeOH extract of Allium macrostemon Bunge. The identification and structural elucidation of these compounds were based on their 1D- and 2D-NMR spectra, and HR-FAB-MS data analysis. The isolated compounds were tested for cytotoxicity against four human tumor cell lines in vitro using the sulforhodamine B bioassay.

  3. Pestalofones A-E, bioactive cyclohexanone derivatives from the plant endophytic fungus Pestalotiopsis fici.

    PubMed

    Liu, Ling; Liu, Shuchun; Chen, Xulin; Guo, Liangdong; Che, Yongsheng

    2009-01-15

    Pestalofones A-E (1-5), five new cyclohexanone derivatives, have been isolated from cultures of the plant endophytic fungus Pestalotiopsis fici, along with the known compounds, isosulochrin (6), isosulochrin dehydrate (7), and iso-A82775C (8). The structures of 1-5 were determined by NMR spectroscopy, and the absolute configuration of 1 was assigned using the modified Mosher method. Compounds 1, 2, and 5 displayed inhibitory effects on HIV-1 replication in C8166 cells, whereas 3 and 5 showed significant antifungal activity against Aspergillus fumigatus.

  4. Report on the Workshop Herbig Ae/Be Stars: The Missing Link in Star Formation

    NASA Astrophysics Data System (ADS)

    de Wit, W.-J.; Oudmaijer, R. D.; van den Ancker, M. E.; Calvet, N.

    2014-09-01

    The workshop highlighted the many recent advances within the field of Herbig Ae/Be stars and the close links to star and planet formation. Topics such as magnetospheric accretion and the evolution of dust in discs, the structure of circumstellar discs and the role of walls and gaps and their links to planet formation from many observational aspects were covered. The workshop was dedicated to the life and works of George H. Herbig, who sadly passed away at the end of last year.

  5. A study of Herbig Ae Be star HD 163296: variability in co and oh

    NASA Astrophysics Data System (ADS)

    Yoder, Diana Lyn Hubis

    Spectra of the Herbig Ae Be star HD 163296 show variability in the CO and OH ro-vibrational emission lines. Documented here is the variance of OH emission lines between measurements separated by a period of three years. By comparing this variability to the variability of CO, we aim to determine whether the two are linked through an event such as disk winds. We find the profiles of OH and CO taken within three months of each other to have exceedingly similar profile shapes. However, the variability seen between the OH data sets needs further work to verify whether the changes we see are reproducible.

  6. Synthesis of hybrid sol-gel coatings for corrosion protection of we54-ae magnesium alloy

    NASA Astrophysics Data System (ADS)

    Hernández-Barrios, C. A.; Duarte, N. Z.; Hernández, L. M.; Peña, D. Y.; Coy, A. E.; Viejo, F.

    2013-11-01

    The present work shows some preliminary results related to the synthesis, characterization and corrosion evaluation of different hybrid sol-gel coatings applied on the WE54-AE magnesium alloy attending to the two experimental variables, i.e. the precursors ratio and the aging time, which may affect the quality and the electrochemical properties of the coatings resultant. The experimental results confirmed that, under some specific experimental conditions, it was possible to obtain homogeneous and uniform, porous coatings with good corrosion resistance that also permit to accommodate corrosion inhibitors.

  7. Low-dimensional chaos in magnetospheric activity from AE time series

    NASA Technical Reports Server (NTRS)

    Vassiliadis, D. V.; Sharma, A. S.; Eastman, T. E.; Papadopoulos, K.

    1990-01-01

    The magnetospheric response to the solar-wind input, as represented by the time-series measurements of the auroral electrojet (AE) index, has been examined using phase-space reconstruction techniques. The system was found to behave as a low-dimensional chaotic system with a fractal dimension of 3.6 and has Kolmogorov entropy less than 0.2/min. These indicate that the dynamics of the system can be adequately described by four independent variables, and that the corresponding intrinsic time scale is of the order of 5 min. The relevance of the results to magnetospheric modeling is discussed.

  8. Determination of soil micronutrients (Fe, Cu, Mn, B) extracted by Mehlich 3 using MP-AES

    NASA Astrophysics Data System (ADS)

    Krebstein, Kadri; Tõnutare, Tõnu; Rodima, Ako; Kõlli, Raimo; Künnapas, Allan; Rebane, Jaanus; Penu, Priit; Vennik, Kersti; Soobik, Liina

    2015-04-01

    The total concentration of micronutrients in soils is not a good predictor of its bioavailability and solubility. Therefore, during the decades several methods for the determination of plant availability and extractable fraction of micro- and macronutrients in soil were developed. Among several methods Mehlich 3 is the most appropriate due to its suitability for extracting soil micro- and macronutrients simultaneously. The AAS (atomic absorption spectroscopic) and ICP (inductively coupled plasma) methods are widely used for the analysis of microelements today. In 2011 the third method was added to this list with the appearance of the microwave plasma atomic emission spectrometer (MP-AES). This multielemental analytical equipment has a high potential in the soil analysis. Up to now there have been made some experiments for the use of MP-AES in soil and geological material analysis. But there is no information about the analysis of soil micronutrients extracted according to Mehlich 3 method and determined with the MP-AES. Due to the differences in atomization conditions the different emission and absorption lines are used in different instrumental methods. Therefore it is very important to choose the most suitable emission lines and the best atomization conditions. From the analytical viewpoint it is important to get coincidental results with other instrumental methods and from the agronomical point of view it is important to know the difference between AAS and ICP methods. For the experiment 51 soil samples were used. The samples were collected from A horizons of agricultural lands. The pH range was from 4.7 to 7.5 and organic matter content from 1.4 to 7.8%. The content of Mehlich 3 extractable micronutrients was determined using ICP and MP instrumental methods. The micronutrient contents ranged as follows: Fe - from 170 to 470 mg kg-1, Mn - from 5 to 190 mg kg-1, Cu - from 0.3 to 4.5 mg kg-1, B - from 0.2 to 2.1 mg kg-1. The optimal instrumental settings for iron

  9. Conceptual design of the AE481 Demon Remotely Piloted Vehicle (RPV)

    NASA Technical Reports Server (NTRS)

    Hailes, Chris; Kolver, Jill; Nestor, Julie; Patterson, Mike; Selow, Jan; Sagdeo, Pradip; Katz, Kenneth

    1994-01-01

    This project report presents a conceptual design for a high speed remotely piloted vehicle (RPV). The AE481 Demon RPV is capable of performing video reconnaissance missions and electronic jamming over hostile territory. The RPV cruises at a speed of Mach 0.8 and an altitude of 300 feet above the ground throughout its mission. It incorporates a rocket assisted takeoff and a parachute-airbag landing. Missions are preprogrammed, but in-flight changes are possible. The Demon is the answer to a military need for a high speed, low altitude RPV. The design methods, onboard systems, and avionics payload are discussed in this conceptual design report along with economic viability.

  10. Source mechanism of Vulcanian degassing at Popocatépetl Volcano, Mexico, determined from waveform inversions of very long period signals

    USGS Publications Warehouse

    Chouet, Bernard A.; Dawson, Phillip B.; Arciniega-Ceballos, Alejandra

    2005-01-01

    The source mechanism of very long period (VLP) signals accompanying volcanic degassing bursts at Popocatépetl is analyzed in the 15–70 s band by minimizing the residual error between data and synthetics calculated for a point source embedded in a homogeneous medium. The waveforms of two eruptions (23 April and 23 May 2000) representative of mild Vulcanian activity are well reproduced by our inversion, which takes into account volcano topography. The source centroid is positioned 1500 m below the western perimeter of the summit crater, and the modeled source is composed of a shallow dipping crack (sill with easterly dip of 10°) intersecting a steeply dipping crack (northeast striking dike dipping 83° northwest), whose surface extension bisects the vent. Both cracks undergo a similar sequence of inflation, deflation, and reinflation, reflecting a cycle of pressurization, depressurization, and repressurization within a time interval of 3–5 min. The largest moment release occurs in the sill, showing a maximum volume change of 500–1000 m3, pressure drop of 3–5 MPa, and amplitude of recovered pressure equal to 1.2 times the amplitude of the pressure drop. In contrast, the maximum volume change in the dike is less (200–300 m3), with a corresponding pressure drop of 1–2 MPa and pressure recovery equal to the pressure drop. Accompanying these volumetric sources are single-force components with magnitudes of 108 N, consistent with melt advection in response to pressure transients. The source time histories of the volumetric components of the source indicate that significant mass movement starts within the sill and triggers a mass movement response in the dike within a few seconds. Such source behavior is consistent with the opening of a pathway for escape of pent-up gases from slow pressurization of the sill driven by magma crystallization. The opening of this pathway and associated rapid evacuation of volcanic gases induces the pressure drop. Pressure

  11. Acoustic emission source localization in thin metallic plates: A single-sensor approach based on multimodal edge reflections.

    PubMed

    Ebrahimkhanlou, A; Salamone, S

    2017-03-14

    This paper presents a new acoustic emission (AE) source localization for isotropic plates with reflecting boundaries. This approach that has no blind spot leverages multimodal edge reflections to identify AE sources with only a single sensor. The implementation of the proposed approach involves three main steps. First, the continuous wavelet transform (CWT) and the dispersion curves of the fundamental Lamb wave modes are utilized to estimate the distance between an AE source and a sensor. This step uses a modal acoustic emission approach. Then, an analytical model is proposed that uses the estimated distances to simulate the edge-reflected waves. Finally, the correlation between the experimental and the simulated waveforms is used to estimate the location of AE sources. Hsu-Nielsen pencil lead break (PLB) tests were performed on an aluminum plate to validate this algorithm and promising results were achieved. Based on these results, the paper reports the statistics of the localization errors.

  12. Knowledge Discovery Process for Characterization of Materials Failure Mechanism

    NASA Technical Reports Server (NTRS)

    Cios, Krzysztof J.

    1999-01-01

    It is the intent of this project to provide a platform to visualize the various data collected from stress-strain testing of composite ceramic matrix materials. The data collected from the stress-strain tests are acoustic emissions (AE). As a material is subjected to a stress-strain test, various failure mechanisms occur in the material. The recorded sounds emitted during the test may correspond to various failure mechanisms. This project, thus, will give a possible way to visualize the data and data derived from the recorded AE. The stress-strain testing was performed on several composite matrix material combinations. Each of these tests produced anywhere from 1000 to 10,000+ AE events. For each AE event recorded, several characteristics in both the time and frequency domains are created. This project has two goals. First, this project will provide a summation page for a selected waveform. This page will include all of the characteristics determined from the AE event waveform along with graphs of the AE event waveform and its corresponding Power Spectrum. The other function of this project is to retrieve and display selected AE event waveforms for comparison.

  13. Identifying transfer mechanisms and sources of decabromodiphenyl ether (BDE 209) in indoor environments using environmental forensic microscopy.

    PubMed

    Webster, Thomas F; Harrad, Stuart; Millette, James R; Holbrook, R David; Davis, Jeffrey M; Stapleton, Heather M; Allen, Joseph G; McClean, Michael D; Ibarra, Catalina; Abdallah, Mohamed Abou-Elwafa; Covaci, Adrian

    2009-05-01

    Although the presence of polybrominated diphenyl ethers (PBDEs) in house dust has been linked to consumer products, the mechanism of transfer remains poorly understood. We conjecture that volatilized PBDEs will be associated with dust particles containing organic matter and will be homogeneously distributed in house dust. In contrast, PBDEs arising from weathering or abrasion of polymers should remain bound to particles of the original polymer matrix and will be heterogeneously distributed within the dust. We used scanning electron microscopy and othertools of environmental forensic microscopy to investigate PBDEs in dust, examining U.S. and U.K. dust samples with extremely high levels of BDE 209 (260-2600 microg/g), a nonvolatile compound at room temperature. We found that the bromine in these samples was concentrated in widely scattered, highly contaminated particles. In the house dust samples from Boston (U.S.), bromine was associated with a polymer/organic matrix. These results suggest that the BDE 209 was transferred to dust via physical processes such as abrasion or weathering. In conjunction with more traditional tools of environmental chemistry, such as gas chromatography/mass spectrometry (GC/MS), environmental forensic microscopy provides novel insights into the origins of BDE 209 in dust and their mechanisms of transfer from products.

  14. Source mechanism and stress analysis of 23 October 2011 Van Earthquake ( Mw = 7.1) and aftershocks

    NASA Astrophysics Data System (ADS)

    Kalafat, Doğan; Kekovalı, Kıvanç; Akkoyunlu, Feyza; Ögütçü, Zafer

    2014-07-01

    On 23 October 2011 at 1341 local time, a strong earthquake ( Mw = 7.1) occurred east of Lake Van (KOERI; Kandilli Observatory and Earthquake Research Institute). The focal parameters of the main shock and 29 aftershocks with M ≥ 4.0 were obtained from regional broadband seismic data from KOERI network by using Regional Moment Tensor Inversion Code (Dreger 2002). It is confirmed that the main shock had thrust faulting mechanism. The stress tensor analysis was completed using the focal mechanism solutions and the software developed by (Gephart Comp Geosci 16: 953-989, 1990). The maximum principal stress ( P compressional) of the main shock is aligned in a N-S (NNW/SSE) direction and the tensional axis ( T dilatation) is aligned in an E-W (ENE-WSW) direction. The b value is calculated as 0.96 using the maximum likelihood method (Utsu 1999).

  15. Identifying transfer mechanisms and sources of decabromodiphenyl ether (BDE 209) in indoor environments using environmental forensic microscopy

    PubMed Central

    Webster, Thomas F.; Harrad, Stuart; Millette, James R.; Holbrook, R. David; Davis, Jeffrey M.; Stapleton, Heather M.; Allen, Joseph G.; McClean, Michael D.; Ibarra, Catalina; Abdallah, Mohamed Abou-Elwafa; Covaci, Adrian

    2009-01-01

    Although the presence of polybrominated diphenyl ethers (PBDEs) in house dust has been linked to consumer products, the mechanism of transfer remains poorly understood. We conjecture that volatilized PBDEs will be associated with dust particles containing organic matter and will be homogeneously distributed in house dust. In contrast, PBDEs arising from weathering or abrasion of polymers should remain bound to particles of the original polymer matrix and will be heterogeneously distributed within the dust. We used scanning electron microscopy and other tools of environmental forensic microscopy to investigate PBDEs in dust, examining U.S.A. and U.K. dust samples with extremely high levels of BDE 209 (260–2600 µg/g), a non-volatile compound at room temperature. We found that the bromine in these samples was concentrated in widely scattered, highly contaminated particles. In the house dust samples from Boston (U.S.), bromine was associated with a polymer/organic matrix. These results suggest that the BDE 209 was transferred to dust via physical processes such as abrasion or weathering. In conjunction with more traditional tools of environmental chemistry, such as gas chromatography-mass spectrometry (GC/MS), environmental forensic microscopy provides novel insights into the origins of BDE 209 in dust and their mechanisms of transfer from products. PMID:19534115

  16. Constraints on the physical mechanism of intermediate-depth earthquake rupture in the Cauca Cluster, Colombia, through a source parameter analysis

    NASA Astrophysics Data System (ADS)

    Chango, Robert

    Earthquakes are the result of the sudden release of elastic energy by brittle failure. Such frictional processes are controlled by temperature and pressure. Temperature and pressure within the Earth increase with depth, which should make the rock flow. Even in subduction zones, where temperatures are lower than expected, the high confining pressure should prevent ordinary brittle failure. Therefore earthquakes deeper than 60 km are not expected. In fact, 25% of worldwide seismicity occurs deeper than 60 km. Deep seismicity usually occurs within the subducting slab in subduction zones. In this study, we estimate the source parameters of intermediate-depth earthquakes (60-300 km) in the Cauca cluster ( 4° N, 76.5° W) in Colombia to understand the physical mechanism responsible for these earthquakes. A cluster is a volume of high seismic activity surrounded by a zone of low activity rates. Source parameters are quantitative estimations of the size, strength and dynamics of the earthquakes. The source parameters can be estimated from the energy spectra of earthquakes by fitting a theoretical model. To obtain the spectra we use a multitaper technique. Because the spectra is the convolution of source, receiver and attenuation, we isolate the source and receiver by iteratively stacking the spectra. The stacking is a reasonable approach since the Colombian seismic network has a dense distribution of stations recording right above the cluster. We fit our observed spectra with the theoretical Brune model to obtain corner frequencies. P-wave corner frequencies range from 5.9 to 9.1 Hz for events with ML between 2.6-4.7. S-wave corner frequencies range from 5.2 to 9.1 Hz for events with ML between 2.5-4.5. Earthquakes with larger ML seem to follow the Brune model trend for large stress drops. Even though we have inconclusive results, our small corner frequencies and high stress drops for larger magnitudes would support thermal shear instability as the physical mechanism

  17. Strategies to improve phase-stability of ultrafast swept source optical coherence tomography for single shot imaging of transient mechanical waves at 16 kHz frame rate

    NASA Astrophysics Data System (ADS)

    Song, Shaozhen; Wei, Wei; Hsieh, Bao-Yu; Pelivanov, Ivan; Shen, Tueng T.; O'Donnell, Matthew; Wang, Ruikang K.

    2016-05-01

    We present single-shot phase-sensitive imaging of propagating mechanical waves within tissue, enabled by an ultrafast optical coherence tomography (OCT) system powered by a 1.628 MHz Fourier domain mode-locked (FDML) swept laser source. We propose a practical strategy for phase-sensitive measurement by comparing the phases between adjacent OCT B-scans, where the B-scan contains a number of A-scans equaling an integer number of FDML buffers. With this approach, we show that micro-strain fields can be mapped with ˜3.0 nm sensitivity at ˜16 000 fps. The system's capabilities are demonstrated on porcine cornea by imaging mechanical wave propagation launched by a pulsed UV laser beam, promising non-contact, real-time, and high-resolution optical coherence elastography.

  18. Dental pulp stem cells express tendon markers under mechanical loading and are a potential cell source for tissue engineering of tendon-like tissue.

    PubMed

    Chen, Yu-Ying; He, Sheng-Teng; Yan, Fu-Hua; Zhou, Peng-Fei; Luo, Kai; Zhang, Yan-Ding; Xiao, Yin; Lin, Min-Kui

    2016-12-16

    Postnatal mesenchymal stem cells have the capacity to differentiate into multiple cell lineages. This study explored the possibility of dental pulp stem cells (DPSCs) for potential application in tendon tissue engineering. The expression of tendon-related markers such as scleraxis, tenascin-C, tenomodulin, eye absent homologue 2, collagens I and VI was detected in dental pulp tissue. Interestingly, under mechanical stimulation, these tendon-related markers were significantly enhanced when DPSCs were seeded in aligned polyglycolic acid (PGA) fibre scaffolds. Furthermore, mature tendon-like tissue was formed after transplantation of DPSC-PGA constructs under mechanical loading conditions in a mouse model. This study demonstrates that DPSCs could be a potential stem cell source for tissue engineering of tendon-like tissue.

  19. Dental pulp stem cells express tendon markers under mechanical loading and are a potential cell source for tissue engineering of tendon-like tissue

    PubMed Central

    Chen, Yu-Ying; He, Sheng-Teng; Yan, Fu-Hua; Zhou, Peng-Fei; Luo, Kai; Zhang, Yan-Ding; Xiao, Yin; Lin, Min-Kui

    2016-01-01

    Postnatal mesenchymal stem cells have the capacity to differentiate into multiple cell lineages. This study explored the possibility of dental pulp stem cells (DPSCs) for potential application in tendon tissue engineering. The expression of tendon-related markers such as scleraxis, tenascin-C, tenomodulin, eye absent homologue 2, collagens I and VI was detected in dental pulp tissue. Interestingly, under mechanical stimulation, these tendon-related markers were significantly enhanced when DPSCs were seeded in aligned polyglycolic acid (PGA) fibre scaffolds. Furthermore, mature tendon-like tissue was formed after transplantation of DPSC-PGA constructs under mechanical loading conditions in a mouse model. This study demonstrates that DPSCs could be a potential stem cell source for tissue engineering of tendon-like tissue. PMID:27811845

  20. Source mechanism of small long-period events at Mount St. Helens in July 2005 using template matching, phase-weighted stacking, and full-waveform inversion

    USGS Publications Warehouse

    Matoza, Robin S.; Chouet, Bernard A.; Dawson, Phillip B.; Shearer, Peter M.; Haney, Matthew M.; Waite, Gregory P.; Moran, Seth C.; Mikesell, T. Dylan

    2015-01-01

    Long-period (LP, 0.5-5 Hz) seismicity, observed at volcanoes worldwide, is a recognized signature of unrest and eruption. Cyclic LP “drumbeating” was the characteristic seismicity accompanying the sustained dome-building phase of the 2004–2008 eruption of Mount St. Helens (MSH), WA. However, together with the LP drumbeating was a near-continuous, randomly occurring series of tiny LP seismic events (LP “subevents”), which may hold important additional information on the mechanism of seismogenesis at restless volcanoes. We employ template matching, phase-weighted stacking, and full-waveform inversion to image the source mechanism of one multiplet of these LP subevents at MSH in July 2005. The signal-to-noise ratios of the individual events are too low to produce reliable waveform-inversion results, but the events are repetitive and can be stacked. We apply network-based template matching to 8 days of continuous velocity waveform data from 29 June to 7 July 2005 using a master event to detect 822 network triggers. We stack waveforms for 359 high-quality triggers at each station and component, using a combination of linear and phase-weighted stacking to produce clean stacks for use in waveform inversion. The derived source mechanism pointsto the volumetric oscillation (~10 m3) of a subhorizontal crack located at shallow depth (~30 m) in an area to the south of Crater Glacier in the southern portion of the breached MSH crater. A possible excitation mechanism is the sudden condensation of metastable steam from a shallow pressurized hydrothermal system as it encounters cool meteoric water in the outer parts of the edifice, perhaps supplied from snow melt.