Science.gov

Sample records for 0-10 cm depth

  1. Estimation of CO2 diffusion coefficient at 0-10 cm depth in undisturbed and tilled soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diffusion coefficients (D) of CO2 at 0 – 10 cm layers in undisturbed and tilled soil conditions were estimated using Penman, Millington-Quirk, Ridgwell et al. (1999), Troeh et al., and Moldrup et al. models. Soil bulk density and volumetric soil water content ('v) at 0 – 10 cm were measured on April...

  2. Creation of 0.10 cm-1 Resolution, Quantitative, Infrared Spectral Libraries for Gas Samples

    SciTech Connect

    Sharpe, Steven W.; Sams, Robert L.; Johnson, Timothy J.; Chu, P M.; Rhoderick, G C.; Guenther, F R.; Steven D. Christensen; Arthur J. Sedlacek

    2002-02-01

    The National Institute of Standards and Technology (NIST) and the Pacific Northwest National Laboratory (PNNL) are independently creating quantitative, approximately 0.10 cm-1 resolution, infrared spectral libraries of vapor phase compounds. The NIST library will consist of approximately 100 vapor phase spectra of volatile hazardous air pollutants (HAPs) and suspected greenhouse gases. The PNNL library will consist of approximately 400 vapor phase spectra associated with DOE's remediation mission. A critical part of creating and validating any quantitative work involves independent verification based on inter-laboratory comparisons. The two laboratories use significantly different sample preparation and handling techniques. NIST uses gravimetric dilution and a continuous flowing sample while PNNL uses partial pressure dilution and a static sample. Agreement is generally found to be within the statistical uncertainties of the Beer's law fit and less than 3 percent of the total integrate d band areas for the 4 chemicals used in this comparison. There does appear to be a small systematic difference between the PNNL and NIST data, however. Possible sources of the systematic difference will be discussed as well as technical details concerning the sample preparation and the procedures for overcoming instrumental artifacts.

  3. Muon and neutrino results from KGF experiment at a depth of 7000 hg/square cm

    NASA Technical Reports Server (NTRS)

    Krishnaswamy, M. R.; Menon, M. G. K.; Mondal, N. K.; Narasimham, V. S.; Streekantan, B. V.; Hayashi, Y.; Ito, N.; Kawakami, S.; Miyake, S.

    1985-01-01

    The KGF nucleon decay experiment at a depth of 7000 hg/sq cm has provided valuable data on muons and neutrinos. The detector comprised of 34 crossed layers of proportional counters (cross section 10 x 10 sq cm; lengths 4m and 6m) sandwiched between 1.2 cm thick iron plates can record tracks of charged particles to an accuracy of 1 deg from tracks that traverse the whole of the detector. A special two-fold coincidence system enables the detector to record charged particles that enter at very large zenith angles. In a live time of 3.6 years about 2600 events have been recorded. These events include atmospheric muons, neutrino induced muons from rock, stopping muons, showers and events which have their production vertex inside the detectors. The results on atmospheric muons and neutrino events are presented.

  4. A case study demonstration of the soil temperature extrema recovery rates after precipitation cooling at 10-cm soil depth

    NASA Technical Reports Server (NTRS)

    Welker, Jean Edward

    1991-01-01

    Since the invention of maximum and minimum thermometers in the 18th century, diurnal temperature extrema have been taken for air worldwide. At some stations, these extrema temperatures were collected at various soil depths also, and the behavior of these temperatures at a 10-cm depth at the Tifton Experimental Station in Georgia is presented. After a precipitation cooling event, the diurnal temperature maxima drop to a minimum value and then start a recovery to higher values (similar to thermal inertia). This recovery represents a measure of response to heating as a function of soil moisture and soil property. Eight different curves were fitted to a wide variety of data sets for different stations and years, and both power and exponential curves were fitted to a wide variety of data sets for different stations and years. Both power and exponential curve fits were consistently found to be statistically accurate least-square fit representations of the raw data recovery values. The predictive procedures used here were multivariate regression analyses, which are applicable to soils at a variety of depths besides the 10-cm depth presented.

  5. Precise Measurement of the Reionization Optical Depth from the Global 21 cm Signal Accounting for Cosmic Heating

    NASA Astrophysics Data System (ADS)

    Fialkov, Anastasia; Loeb, Abraham

    2016-04-01

    As a result of our limited data on reionization, the total optical depth for electron scattering, τ, limits precision measurements of cosmological parameters from the Cosmic Microwave Background (CMB). It was recently shown that the predicted 21 cm signal of neutral hydrogen contains enough information to reconstruct τ with sub-percent accuracy, assuming that the neutral gas was much hotter than the CMB throughout the entire epoch of reionization (EoR). Here we relax this assumption and use the global 21 cm signal alone to extract τ for realistic X-ray heating scenarios. We test our model-independent approach using mock data for a wide range of ionization and heating histories and show that an accurate measurement of the reionization optical depth at a sub-percent level is possible in most of the considered scenarios even when heating is not saturated during the EoR, assuming that the foregrounds are mitigated. However, we find that in cases where heating sources had hard X-ray spectra and their luminosity was close to or lower than what is predicted based on low-redshift observations, the global 21 cm signal alone is not a good tracer of the reionization history.

  6. Depth

    PubMed Central

    Koenderink, Jan J; van Doorn, Andrea J; Wagemans, Johan

    2011-01-01

    Depth is the feeling of remoteness, or separateness, that accompanies awareness in human modalities like vision and audition. In specific cases depths can be graded on an ordinal scale, or even measured quantitatively on an interval scale. In the case of pictorial vision this is complicated by the fact that human observers often appear to apply mental transformations that involve depths in distinct visual directions. This implies that a comparison of empirically determined depths between observers involves pictorial space as an integral entity, whereas comparing pictorial depths as such is meaningless. We describe the formal structure of pictorial space purely in the phenomenological domain, without taking recourse to the theories of optics which properly apply to physical space—a distinct ontological domain. We introduce a number of general ways to design and implement methods of geodesy in pictorial space, and discuss some basic problems associated with such measurements. We deal mainly with conceptual issues. PMID:23145244

  7. Depth.

    PubMed

    Koenderink, Jan J; van Doorn, Andrea J; Wagemans, Johan

    2011-01-01

    Depth is the feeling of remoteness, or separateness, that accompanies awareness in human modalities like vision and audition. In specific cases depths can be graded on an ordinal scale, or even measured quantitatively on an interval scale. In the case of pictorial vision this is complicated by the fact that human observers often appear to apply mental transformations that involve depths in distinct visual directions. This implies that a comparison of empirically determined depths between observers involves pictorial space as an integral entity, whereas comparing pictorial depths as such is meaningless. We describe the formal structure of pictorial space purely in the phenomenological domain, without taking recourse to the theories of optics which properly apply to physical space-a distinct ontological domain. We introduce a number of general ways to design and implement methods of geodesy in pictorial space, and discuss some basic problems associated with such measurements. We deal mainly with conceptual issues.

  8. Droplet size spectra and water-vapor concentration of laboratory water clouds: inversion of Fourier transform infrared (500-5000 cm(-1)) optical-depth measurement.

    PubMed

    Arnott, W P; Schmitt, C; Liu, Y; Hallett, J

    1997-07-20

    Infrared extinction optical depth (500-5000 cm(-1)) has been measured with a Fourier transform infrared spectrometer for clouds produced with an ultrasonic nebulizer. Direct measurement of the cloud droplet size spectra agree with size spectra retrieved from inversion of the extinction measurements. Both indicate that the range of droplet sizes is 1-14 mum. The retrieval was accomplished with an iterative algorithm that simultaneously obtains water-vapor concentration. The basis set of droplet extinction functions are computed once by using numerical integration of the Lorenz-Mie theory over narrow size bins, and a measured water-vapor extinction curve was used. Extinction and size spectra are measured and computed for both steady-state and dissipating clouds. It is demonstrated that anomalous diffraction theory produces relatively poor droplet size and synthetic extinction spectra and that extinction measurements are helpful in assessing the validity of various theories. Calculations of cloud liquid-water content from retrieved size distributions agree with a parameterization based on optical-depth measurements at a wave number of 906 cm(-1) for clouds that satisfy the size spectral range assumptions of the parameterization. Significance of droplet and vapor contribution to the total optical depth is used to evaluate the reliability of spectral inversions. PMID:18259335

  9. Droplet size spectra and water-vapor concentration of laboratory water clouds: inversion of Fourier transform infrared (500-5000 cm(-1)) optical-depth measurement.

    PubMed

    Arnott, W P; Schmitt, C; Liu, Y; Hallett, J

    1997-07-20

    Infrared extinction optical depth (500-5000 cm(-1)) has been measured with a Fourier transform infrared spectrometer for clouds produced with an ultrasonic nebulizer. Direct measurement of the cloud droplet size spectra agree with size spectra retrieved from inversion of the extinction measurements. Both indicate that the range of droplet sizes is 1-14 mum. The retrieval was accomplished with an iterative algorithm that simultaneously obtains water-vapor concentration. The basis set of droplet extinction functions are computed once by using numerical integration of the Lorenz-Mie theory over narrow size bins, and a measured water-vapor extinction curve was used. Extinction and size spectra are measured and computed for both steady-state and dissipating clouds. It is demonstrated that anomalous diffraction theory produces relatively poor droplet size and synthetic extinction spectra and that extinction measurements are helpful in assessing the validity of various theories. Calculations of cloud liquid-water content from retrieved size distributions agree with a parameterization based on optical-depth measurements at a wave number of 906 cm(-1) for clouds that satisfy the size spectral range assumptions of the parameterization. Significance of droplet and vapor contribution to the total optical depth is used to evaluate the reliability of spectral inversions.

  10. 16 CFR 0.10 - Office of the Executive Director.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Section 0.10 Commercial Practices FEDERAL TRADE COMMISSION ORGANIZATION, PROCEDURES AND RULES OF PRACTICE... policies, programs and directives for the Commission. The Executive Director works closely with the Bureaus.... In addition, the Executive Director manages the Commission's facilities and administrative...

  11. 16 CFR 0.10 - Office of the Executive Director.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Section 0.10 Commercial Practices FEDERAL TRADE COMMISSION ORGANIZATION, PROCEDURES AND RULES OF PRACTICE... policies, programs and directives for the Commission. The Executive Director works closely with the Bureaus.... In addition, the Executive Director manages the Commission's facilities and administrative...

  12. 16 CFR 0.10 - Office of the Executive Director.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Section 0.10 Commercial Practices FEDERAL TRADE COMMISSION ORGANIZATION, PROCEDURES AND RULES OF PRACTICE... policies, programs and directives for the Commission. The Executive Director works closely with the Bureaus.... In addition, the Executive Director manages the Commission's facilities and administrative...

  13. 16 CFR 0.10 - Office of the Executive Director.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Section 0.10 Commercial Practices FEDERAL TRADE COMMISSION ORGANIZATION, PROCEDURES AND RULES OF PRACTICE... policies, programs and directives for the Commission. The Executive Director works closely with the Bureaus.... In addition, the Executive Director manages the Commission's facilities and administrative...

  14. 16 CFR 0.10 - Office of the Executive Director.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Section 0.10 Commercial Practices FEDERAL TRADE COMMISSION ORGANIZATION, PROCEDURES AND RULES OF PRACTICE... policies, programs and directives for the Commission. The Executive Director works closely with the Bureaus.... In addition, the Executive Director manages the Commission's facilities and administrative...

  15. A CM chondrite cluster and CM streams

    NASA Technical Reports Server (NTRS)

    Dodd, R. T.; Lipschutz, M. E.

    1993-01-01

    An elongate year-day concentration of CM meteoroid falls between 1921 and 1969 is inconsistent with a random flux of CM meteoroids and suggests that most or all such meteorites, and perhaps the Kaidun C-E chondrite breccia, resulted from streams of meteoroids in nearly circular, Earth-like orbits. To establish whether the post-1920 cluster might have arisen from random sampling, we determined the year-day distribution of 14 falls between 1879 and 1969 by treating each as the corner of a cell of specified dimensions (e.g. 30 years x 30 days) and calculated how many falls occurred in that cell. We then compared the CM cell distribution with random distributions over the same range of years. The results show that for 30 x 30 and 45 x 45 cells, fewer than 5 percent of random sets match the CM distribution with respect to maximum cell content and number of one-fall cells.

  16. Irrigation depth far exceeds water uptake depth in an oasis cropland in the middle reaches of Heihe River Basin

    NASA Astrophysics Data System (ADS)

    Yang, Bin; Wen, Xuefa; Sun, Xiaomin

    2015-10-01

    Agricultural irrigation in the middle reaches of the Heihe River Basin consumes approximately 80% of the total river water. Whether the irrigation depth matches the water uptake depth of crops is one of the most important factors affecting the efficiency of irrigation water use. Our results indicated that the influence of plastic film on soil water δ18O was restricted to 0-30 cm soil depth. Based on a Bayesian model (MixSIR), we found that irrigated maize acquired water preferentially from 0-10cm soil layer, with a median uptake proportion of 87 ± 15%. Additionally, maize utilised a mixture of irrigation and shallow soil water instead of absorbing the irrigation water directly. However, only 24.7 ± 5.5% of irrigation water remained in 0-10cm soil layer, whereas 29.5 ± 2.8% and 38.4 ± 3.3% of the irrigation water infiltrated into 10-40 cm and 40-80 cm layers. During the 4 irrigation events, approximately 39% of the irrigation and rainwater infiltrated into soil layers below 80 cm. Reducing irrigation amount and developing water-saving irrigation methods will be important strategies for improving the efficiency of irrigation water use in this area.

  17. Irrigation depth far exceeds water uptake depth in an oasis cropland in the middle reaches of Heihe River Basin.

    PubMed

    Yang, Bin; Wen, Xuefa; Sun, Xiaomin

    2015-01-01

    Agricultural irrigation in the middle reaches of the Heihe River Basin consumes approximately 80% of the total river water. Whether the irrigation depth matches the water uptake depth of crops is one of the most important factors affecting the efficiency of irrigation water use. Our results indicated that the influence of plastic film on soil water δ(18)O was restricted to 0-30 cm soil depth. Based on a Bayesian model (MixSIR), we found that irrigated maize acquired water preferentially from 0-10 cm soil layer, with a median uptake proportion of 87 ± 15%. Additionally, maize utilised a mixture of irrigation and shallow soil water instead of absorbing the irrigation water directly. However, only 24.7 ± 5.5% of irrigation water remained in 0-10 cm soil layer, whereas 29.5 ± 2.8% and 38.4 ± 3.3% of the irrigation water infiltrated into 10-40 cm and 40-80 cm layers. During the 4 irrigation events, approximately 39% of the irrigation and rainwater infiltrated into soil layers below 80 cm. Reducing irrigation amount and developing water-saving irrigation methods will be important strategies for improving the efficiency of irrigation water use in this area.

  18. 28 CFR 0.10 - Attorney General's Advisory Committee of U.S. Attorneys.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... the Associate Attorney General in formulating new programs for improvement of the criminal justice... U.S. Attorneys. 0.10 Section 0.10 Judicial Administration DEPARTMENT OF JUSTICE ORGANIZATION OF THE DEPARTMENT OF JUSTICE Office of the Attorney General § 0.10 Attorney General's Advisory Committee of...

  19. 28 CFR 0.10 - Attorney General's Advisory Committee of U.S. Attorneys.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... the Associate Attorney General in formulating new programs for improvement of the criminal justice... U.S. Attorneys. 0.10 Section 0.10 Judicial Administration DEPARTMENT OF JUSTICE ORGANIZATION OF THE DEPARTMENT OF JUSTICE Office of the Attorney General § 0.10 Attorney General's Advisory Committee of...

  20. 28 CFR 0.10 - Attorney General's Advisory Committee of U.S. Attorneys.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... the Associate Attorney General in formulating new programs for improvement of the criminal justice... U.S. Attorneys. 0.10 Section 0.10 Judicial Administration DEPARTMENT OF JUSTICE ORGANIZATION OF THE DEPARTMENT OF JUSTICE Office of the Attorney General § 0.10 Attorney General's Advisory Committee of...

  1. 28 CFR 0.10 - Attorney General's Advisory Committee of U.S. Attorneys.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... the Associate Attorney General in formulating new programs for improvement of the criminal justice... U.S. Attorneys. 0.10 Section 0.10 Judicial Administration DEPARTMENT OF JUSTICE ORGANIZATION OF THE DEPARTMENT OF JUSTICE Office of the Attorney General § 0.10 Attorney General's Advisory Committee of...

  2. 28 CFR 0.10 - Attorney General's Advisory Committee of U.S. Attorneys.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... the Associate Attorney General in formulating new programs for improvement of the criminal justice... U.S. Attorneys. 0.10 Section 0.10 Judicial Administration DEPARTMENT OF JUSTICE ORGANIZATION OF THE DEPARTMENT OF JUSTICE Office of the Attorney General § 0.10 Attorney General's Advisory Committee of...

  3. Ubiquitous CM and DM

    NASA Technical Reports Server (NTRS)

    Crowley, Sandra L.

    2000-01-01

    Ubiquitous is a real word. I thank a former Total Quality Coach for my first exposure some years ago to its existence. My version of Webster's dictionary defines ubiquitous as "present, or seeming to be present, everywhere at the same time; omnipresent." While I believe that God is omnipresent, I have come to discover that CM and DM are present everywhere. Oh, yes; I define CM as Configuration Management and DM as either Data or Document Management. Ten years ago, I had my first introduction to the CM world. I had an opportunity to do CM for the Space Station effort at the NASA Lewis Research Center. I learned that CM was a discipline that had four areas of focus: identification, control, status accounting, and verification. I was certified as a CMIl graduate and was indoctrinated about clear, concise, and valid. Off I went into a world of entirely new experiences. I was exposed to change requests and change boards first hand. I also learned about implementation of changes, and then of technical and CM requirements.

  4. Magnetic, dielectric, magnetoelectric properties and impedance spectroscopy of multiferroic Bi1-xNdxFe1-yCoyO3 (x=0, 0.10, 0.15, 0.20, y=0, 0.10) nanoceramics

    NASA Astrophysics Data System (ADS)

    Bera, K. P.; Mandal, P. R.; Nath, T. K.

    2015-06-01

    Single phase multiferroic Bi1-xNdxFe1-yCoyO3 (x=0, 0.10, 0.15, 0.20; y = 0, 0.10) nanoparticles (average particle size 20-80 nm) were synthesized by novel chemical sol-gel route. The detailed microstructural analysis has been performed using HRXRD, HRTEM and FESEM techniques. The Rietveld refinement of the XRD data reveals that the samples are well crystalline with distorted rhombohedral structure having R3c space group without having any iron rich impurity phases. A noticeably large value of dielectric constant (880) and low tan δ loss (0.04) are observed for the sample Bi0.9Nd0.1Fe0.9Co0.1O3 at 100 Hz at room temperature. An anomaly near the Neel temperature in dielectric measurement has been observed for the samples with x = 0.10 and y = 0.0, 0.10. This anomaly has also been found in temperature dependent dielectric loss curve. A spectacular enhancement of Ms (7.26 emu/gm) and coercivity Hc (1.75 T) has been observed for Bi0.9Nd0.1Fe0.9Co0.1O3 nanoceramics revealing ferromagnetic ordering at the ground state (5 K). We have also observed well saturated P-E Hystersis loops with a remanent polarization (Pr) of 0.2 µC/ cm2 and coercive field Ec of 5 kV/cm for Bi0.9Nd0.1Fe0.9Co0.1O3 nanoceramics.

  5. Halogens in CM Chondrites

    NASA Astrophysics Data System (ADS)

    Menard, J. M.; Caron, B.; Jambon, A.; Michel, A.; Villemant, B.

    2013-09-01

    We set up an extraction line of halogens (fluorine, chlorine) by pyrohydrolysis with 50 mg of rock. We analyzed 7 CM2 chondrites found in Antarctica and found that the Cl content of meteorites with an intact fusion crust is higher than those without.

  6. Measurements of Output Factors For Small Photon Fields Up to 10 cm x 10 cm

    NASA Astrophysics Data System (ADS)

    Bacala, Angelina

    Field output factors (OF) for photon beams from a 6 MV medical accelerator were measured using five different detectors in a scanning water phantom. The measurements were taken for square field sizes of integral widths ranging from 1 cm to 10 cm for two reference source-to-surface distances (SSD) and depths in water. For the diode detectors, square field widths as small as 2.5 mm were also studied. The photon beams were collimated by using either the jaws or the multileaf collimators. Measured OFs are found to depend upon the field size, SSD, depth and also upon the type of beam collimation, size and type of detector used. For field sizes larger than 3 cm x 3 cm, the OF measurements agree to within 1% or less. The largest variation in OF occurs for jawsshaped field of size 1 cm x 1cm, where a difference of more than 18% is observed.

  7. Shallow (0-10) seismic investigation of a distressed earthen levee, New Orleans, USA

    NASA Astrophysics Data System (ADS)

    Lorenzo, J. M.; Hicks, J.; Vera, E. E.

    2009-12-01

    Both deep- and near-surface hydrogeologic processes can contribute to the structural failure of artificial earthen levees. Recently, seismic geophysical methods have attempted to develop a proxy for engineering shear strength, by mapping changes in the transmission velocity of shear waves. High fluid content may indicate both weak, under-compacted materials and/or organic-rich sediments. In the absence of electromagnetic methods, Vp/Vs ratios can be used as good indicators of variations in the fluid (water, and air or gas) saturation. Cone penetration borehole tests measure the resistance of soils to penetration of the cone tip and its frictional sliding that can be correlated to sediment types and their physical properties. A distressed section of an artificial earthen levee, suitable for seismic investigation, lies ~15 km S of the city of New Orleans, Louisiana, USA. Open curvilinear fissures, 10 cm wide, 30 cm deep, and up to 100 m in length, exist along the crest at two sites. Between September 2007 and February 2008 we collect horizontally (SH) polarized shear and compressional wave (P) data in pseudo-walkaway tests for the upper 100 m of the subsurface along the protected (west) side of the earthen levee, within 30 m of its crest. One profile lies parallel and adjacent to the damaged levee crest and, for reference, two profiles lie nearby adjacent to undamaged portions of the artificial earthen levee. In the first ~30 m of sediment below the lower delta plain of the Greater New Orleans area, a complex and dynamic interaction of freshwater and marine sedimentary environments juxtaposes a diverse set of facies. We combine of Vp and Vs velocity maps, sedimentary environment interpretations, and cone-penetration-derived sediment/soil and laboratory-derived physical properties to locate possible zones of high fluid concentration, (and perhaps seepage), weak engineering materials, and natural foundation soil shear strength. Under the distressed portion of the

  8. Apparent Depth.

    ERIC Educational Resources Information Center

    Nassar, Antonio B.

    1994-01-01

    Discusses a well-known optical refraction problem where the depth of an object in a liquid is determined. Proposes that many texts incorrectly solve the problem. Provides theory, equations, and diagrams. (MVL)

  9. Process advances to achieve ultra-shallow junctions for 0.10 μm technology requirements

    NASA Astrophysics Data System (ADS)

    Bertuch, Adam F.; Zhao, Zhiyong; Downey, Daniel F.; Falk, Scott W.

    1999-06-01

    Ion implants of 11B+, 49BF2+, 31P+ and 75As+ at energies as low as 0.25 keV at various doses were implanted and rapid thermal annealed (RTA) with controlled O2 levels in N2 ambient to investigate the effects of oxygen during anneal. For each of these implant species, an optimal RTA ambient of O2 in N2 is established which maximizes retained dose and uniformity while minimizing oxidation enhanced diffusion (OED) and other oxygen related diffusion effects. TEM analysis was performed for all species and energy thresholds identified (at 1e15/cm2), below which no extended-defects or loops were observed to form and hence a regime where transient enhanced diffusion (TED) should not affect dopant diffusion. In this energy regime with anneals in a low ppm O2 in N2 ambient, the contributions from TED, OED, BED (boridation enhanced diffusion or other dopant enhanced diffusion effects) are minimized/eliminated. With these enhanced diffusion mechanisms under control, the effects of minimizing the thermal diffusion by controlled "slow" and "fast" spike anneals (<0.1s) are investigated. Taking advantage of these various processing techniques, source/drain extension requirements to satisfy the National Technology Roadmap (NTRS) requirements at the 0.10 μm node are satisfied for the p-extension by both B (0.25 to 0.5 keV) and BF2 (1.1 to 2.2 keV). In addition, n-extension requirements are meet for As+ (1.0 to 2.0 keV), and P+ (1.0 to 5.0 keV) for contact junctions are reviewed for the NTRS requirements at 0.10μm geometries.

  10. Fabrication, spectral and laser performance of 5 at.% Yb3+ doped (La0.10Y0.90)2O3 transparent ceramic

    NASA Astrophysics Data System (ADS)

    Zhang, Haojia; Yang, Qiuhong; Lu, Shenzhou; Huang, Dongdong; Wang, Yonggang; Wei, Zhiyi; Wang, Qing; Zhang, Yongdong

    2013-02-01

    A 5 at.% Yb3+ doped (La0.10Y0.90)2O3 transparent ceramic was fabricated with nano-powders and sintered in H2 atmosphere. Spectroscopic properties and laser performance of Yb:(La0.10Y0.90)2O3 ceramic were studied. The ceramic exhibits excellent spectroscopic properties, with broad absorption and emission bands, and its refractive index (n) is close to 2. The gain cross-section (σg) was calculated at different population inversion ratio (β) values. In addition, among Yb3+ doped YAG crystal, Y2O3 and (YLa)2O3 ceramic, (YLa)2O3 ceramic has the least pump intensity (Imin) of 1.25 KW cm-2. Furthermore, a diode-pumped C-W ceramic laser output has been demonstrated at 1075 nm with a slope-efficiency of 60.2%.

  11. 17 CFR 270.0-10 - Small entities under the Investment Company Act for purposes of the Regulatory Flexibility Act.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 17 Commodity and Securities Exchanges 4 2014-04-01 2014-04-01 false Small entities under the Investment Company Act for purposes of the Regulatory Flexibility Act. 270.0-10 Section 270.0-10 Commodity... Regulatory Flexibility Act. (a) General. For purposes of Commission rulemaking in accordance with...

  12. 17 CFR 270.0-10 - Small entities under the Investment Company Act for purposes of the Regulatory Flexibility Act.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 17 Commodity and Securities Exchanges 3 2011-04-01 2011-04-01 false Small entities under the Investment Company Act for purposes of the Regulatory Flexibility Act. 270.0-10 Section 270.0-10 Commodity... Regulatory Flexibility Act. (a) General. For purposes of Commission rulemaking in accordance with...

  13. 17 CFR 270.0-10 - Small entities under the Investment Company Act for purposes of the Regulatory Flexibility Act.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 17 Commodity and Securities Exchanges 3 2012-04-01 2012-04-01 false Small entities under the Investment Company Act for purposes of the Regulatory Flexibility Act. 270.0-10 Section 270.0-10 Commodity... Regulatory Flexibility Act. (a) General. For purposes of Commission rulemaking in accordance with...

  14. 17 CFR 270.0-10 - Small entities under the Investment Company Act for purposes of the Regulatory Flexibility Act.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Small entities under the Investment Company Act for purposes of the Regulatory Flexibility Act. 270.0-10 Section 270.0-10 Commodity... Regulatory Flexibility Act. (a) General. For purposes of Commission rulemaking in accordance with...

  15. 17 CFR 270.0-10 - Small entities under the Investment Company Act for purposes of the Regulatory Flexibility Act.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 17 Commodity and Securities Exchanges 3 2013-04-01 2013-04-01 false Small entities under the Investment Company Act for purposes of the Regulatory Flexibility Act. 270.0-10 Section 270.0-10 Commodity... Regulatory Flexibility Act. (a) General. For purposes of Commission rulemaking in accordance with...

  16. Serpentine Nanotubes in CM Chondrites

    NASA Technical Reports Server (NTRS)

    Zega, Thomas J.; Garvie, Laurence A. J.; Dodony, Istvan; Buseck, Peter R.

    2004-01-01

    The CM chondrites are primitive meteorites that formed during the early solar system. Although they retain much of their original physical character, their matrices and fine-grained rims (FGRs) sustained aqueous alteration early in their histories [1- 3]. Serpentine-group minerals are abundant products of such alteration, and information regarding their structures, compositions, and spatial relationships is important for determining the reactions that produced them and the conditions under which they formed. Our recent work on FGRs and matrices of the CM chondrites has revealed new information on the structures and compositions of serpentine-group minerals [4,5] and has provided insights into the evolution of these primitive meteorites. Here we report on serpentine nanotubes from the Mighei and Murchison CM chondrites [6].

  17. 344 cm x 86 cm low mass vacuum window

    SciTech Connect

    Reimers, R.M.; Porter, J.; Meneghetti, J.; Wilde, S.; Miller, R.

    1983-08-01

    The LBL Heavy Ion Spectrometer System (HISS) superconducting magnet contains a 1 m x 3.45 m x 2 m vacuum tank in its gap. A full aperture thin window was needed to minimize background as the products of nuclear collisions move from upstream targets to downstream detectors. Six windows were built and tested in the development process. The final window's unsupported area is 3m/sup 2/ with a 25 cm inward deflection. The design consists of a .11 mm Nylon/aluminum/polypropylene laminate as a gas seal and .55 mm woven aramid fiber for strength. Total mass is 80 milligrams per cm/sup 2/. Development depended heavily on past experience and testing. Safety considerations are discussed.

  18. Stereo depth distortions in teleoperation

    NASA Technical Reports Server (NTRS)

    Diner, Daniel B.; Vonsydow, Marika

    1988-01-01

    In teleoperation, a typical application of stereo vision is to view a work space located short distances (1 to 3m) in front of the cameras. The work presented here treats converged camera placement and studies the effects of intercamera distance, camera-to-object viewing distance, and focal length of the camera lenses on both stereo depth resolution and stereo depth distortion. While viewing the fronto-parallel plane 1.4 m in front of the cameras, depth errors are measured on the order of 2cm. A geometric analysis was made of the distortion of the fronto-parallel plane of divergence for stereo TV viewing. The results of the analysis were then verified experimentally. The objective was to determine the optimal camera configuration which gave high stereo depth resolution while minimizing stereo depth distortion. It is found that for converged cameras at a fixed camera-to-object viewing distance, larger intercamera distances allow higher depth resolutions, but cause greater depth distortions. Thus with larger intercamera distances, operators will make greater depth errors (because of the greater distortions), but will be more certain that they are not errors (because of the higher resolution).

  19. 13C(n,α0)10Be cross section measurement with sCVD diamond detector

    NASA Astrophysics Data System (ADS)

    Kavrigin, P.; Griesmayer, E.; Belloni, F.; Plompen, A. J. M.; Schillebeeckx, P.; Weiss, C.

    2016-06-01

    This paper presents 13C(n, α0)10Be cross section measurements performed at the Van de Graaff facility of the Joint Research Centre Geel. The 13C(n, α0)10Be cross section was measured relative to the 12C(n, α0)9Be cross section at 14.3 MeV and 17.0 MeV neutron energies. The measurements were performed with an sCVD (single-crystal chemical vapor deposition) diamond detector which acted as sample and as sensor simultaneously. A novel analysis technique was applied, which is based on the pulse-shape analysis of the detector's ionization current. This technique resulted in an efficient separation of background events and consequently in a well-determined selection of the nuclear reaction channels 12C(n, α0)9Be and 13C(n, α0)10Be.

  20. Catalytic behaviour and copper leaching of Cu0.10Zn0.90Al1.90Fe0.10O4 spinel for catalytic wet air oxidation of phenol.

    PubMed

    Xu, Aihua; Sun, Chenglin

    2012-06-01

    A Cu0.10Zn0.90Al1.90Fe0.10O4 spinel catalyst prepared by the sol-gel method was tested for catalytic wet air oxidation (CWAO) of phenol. The catalyst showed high activity for phenol degradation. During successive test at 170 degrees C, 100% phenol conversion and 95% chemical oxygen demand (COD) removal were observed. Results from scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) indicated that the catalyst structure remained unchanged during reaction. From the analysis of temperature programmed reduction (TPR), diffuse reflectance UV-Vis spectra (DR UV-Vis) and activity assay at basic solution pH, it can be suggested that the highly dispersed copper ions on the catalyst surface were almost completely dissolved into the reaction solution, whereas the tetra-coordinated copper ions were not only stable against leaching but also active towards phenol degradation.

  1. Catalytic behaviour and copper leaching of Cu0.10Zn0.90Al1.90Fe0.10O4 spinel for catalytic wet air oxidation of phenol.

    PubMed

    Xu, Aihua; Sun, Chenglin

    2012-06-01

    A Cu0.10Zn0.90Al1.90Fe0.10O4 spinel catalyst prepared by the sol-gel method was tested for catalytic wet air oxidation (CWAO) of phenol. The catalyst showed high activity for phenol degradation. During successive test at 170 degrees C, 100% phenol conversion and 95% chemical oxygen demand (COD) removal were observed. Results from scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) indicated that the catalyst structure remained unchanged during reaction. From the analysis of temperature programmed reduction (TPR), diffuse reflectance UV-Vis spectra (DR UV-Vis) and activity assay at basic solution pH, it can be suggested that the highly dispersed copper ions on the catalyst surface were almost completely dissolved into the reaction solution, whereas the tetra-coordinated copper ions were not only stable against leaching but also active towards phenol degradation. PMID:22856307

  2. Spectral reflectance properties of carbonaceous chondrites: 2. CM chondrites

    NASA Astrophysics Data System (ADS)

    Cloutis, E. A.; Hudon, P.; Hiroi, T.; Gaffey, M. J.; Mann, P.

    2011-11-01

    We have examined the spectral reflectance properties and available modal mineralogies of 39 CM carbonaceous chondrites to determine their range of spectral variability and to diagnose their spectral features. We have also reviewed the published literature on CM mineralogy and subclassification, surveyed the published spectral literature and added new measurements of CM chondrites and relevant end members and mineral mixtures, and measured 11 parameters and searched pair-wise for correlations between all quantities. CM spectra are characterized by overall slopes that can range from modestly blue-sloped to red-sloped, with brighter spectra being generally more red-sloped. Spectral slopes, as measured by the 2.4:0.56 μm and 2.4 μm:visible region peak reflectance ratios, range from 0.90 to 2.32, and 0.81 to 2.24, respectively, with values <1 indicating blue-sloped spectra. Matrix-enriched CM spectra can be even more blue-sloped than bulk samples, with ratios as low as 0.85. There is no apparent correlation between spectral slope and grain size for CM chondrite spectra - both fine-grained powders and chips can exhibit blue-sloped spectra. Maximum reflectance across the 0.3-2.5 μm interval ranges from 2.9% to 20.0%, and from 2.8% to 14.0% at 0.56 μm. Matrix-enriched CM spectra can be darker than bulk samples, with maximum reflectance as low as 2.1%. CM spectra exhibit nearly ubiquitous absorption bands near 0.7, 0.9, and 1.1 μm, with depths up to 12%, and, less commonly, absorption bands in other wavelength regions (e.g., 0.4-0.5, 0.65, 2.2 μm). The depths of the 0.7, 0.9, and 1.1 μm absorption features vary largely in tandem, suggesting a single cause, specifically serpentine-group phyllosilicates. The generally high Fe content, high phyllosilicate abundance relative to mafic silicates, and dual Fe valence state in CM phyllosilicates, all suggest that the phyllosilicates will exhibit strong absorption bands in the 0.7 μm region (due to Fe 3+-Fe 2+ charge

  3. 77 FR 8877 - ICD-9-CM Coordination and Maintenance (C&M) Committee Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-15

    ... HUMAN SERVICES Centers for Disease Control and Prevention ICD-9-CM Coordination and Maintenance (C&M... Standards Staff, announces the following meeting. Name: ICD-9-CM Coordination and Maintenance (C&M... attend the ICD- 9-CM C&M meeting on March 5, 2012, must submit their name and organization by February...

  4. Blood alcohol concentration at 0.06 and 0.10% causes a complex multifaceted deterioration of body movement control.

    PubMed

    Modig, Fredrik; Fransson, Per-Anders; Magnusson, Måns; Patel, Mitesh

    2012-02-01

    Alcohol-related falls are recognized as a major contributor to the occurrence of traumatic brain injury. The control of upright standing balance is complex and composes of contributions from several partly independent mechanisms such as appropriate information from multiple sensory systems and correct feedback and feed forward movement control. Analysis of multisegmented body movement offers a rarely used option for detecting the fine motor problems associated with alcohol intoxication. The study aims were to investigate whether (1) alcohol intoxication at 0.06 and 0.10% blood alcohol concentration (BAC) affected the body movements under unperturbed and perturbed standing; and (2) alcohol affected the ability for sensorimotor adaptation. Body movements were recorded in 25 participants (13 women and 12 men, mean age 25.1 years) at five locations (ankle, knee, hip, shoulder, and head) during quiet standing and during balance perturbations from pseudorandom pulses of calf muscle vibration over 200s with eyes closed or open. Tests were performed at 0.00, 0.06, and 0.10% BAC. The study revealed several significant findings: (1) an alcohol dose-specific effect; (2) a direction-specific stability decrease from alcohol intoxication; (3) a movement pattern change related to the level of alcohol intoxication during unperturbed standing and perturbed standing; (4) a sensorimotor adaptation deterioration with increased alcohol intoxication; and (5) that vision provided a weaker contribution to postural control during alcohol intoxication. Hence, alcohol intoxication at 0.06 and 0.10% BAC causes a complex multifaceted deterioration of human postural control.

  5. Compositional Homogeneity of CM Parent Bodies

    NASA Astrophysics Data System (ADS)

    Vernazza, P.; Marsset, M.; Beck, P.; Binzel, R. P.; Birlan, M.; Cloutis, E. A.; DeMeo, F. E.; Dumas, C.; Hiroi, T.

    2016-09-01

    CM chondrites are the most common type of hydrated meteorites, making up ˜1.5% of all falls. Whereas most CM chondrites experienced only low-temperature (˜0°C–120°C) aqueous alteration, the existence of a small fraction of CM chondrites that suffered both hydration and heating complicates our understanding of the early thermal evolution of the CM parent body(ies). Here, we provide new constraints on the collisional and thermal history of CM-like bodies from a comparison between newly acquired spectral measurements of main-belt Ch/Cgh-type asteroids (70 objects) and existing laboratory spectral measurements of CM chondrites. It first appears that the spectral variation observed among CM-like bodies is essentially due to variations in the average regolith grain size. Second, the spectral properties of the vast majority (unheated) of CM chondrites resemble both the surfaces and the interiors of CM-like bodies, implying a “low” temperature (<300°C) thermal evolution of the CM parent body(ies). It follows that an impact origin is the likely explanation for the existence of heated CM chondrites. Finally, similarly to S-type asteroids and (2) Pallas, the surfaces of large (D > 100 km)—supposedly primordial—Ch/Cgh-type main-belt asteroids likely expose the interiors of the primordial CM parent bodies, a possible consequence of impacts by small asteroids (D < 10 km) in the early solar system.

  6. Compositional Homogeneity of CM Parent Bodies

    NASA Astrophysics Data System (ADS)

    Vernazza, P.; Marsset, M.; Beck, P.; Binzel, R. P.; Birlan, M.; Cloutis, E. A.; DeMeo, F. E.; Dumas, C.; Hiroi, T.

    2016-09-01

    CM chondrites are the most common type of hydrated meteorites, making up ˜1.5% of all falls. Whereas most CM chondrites experienced only low-temperature (˜0°C-120°C) aqueous alteration, the existence of a small fraction of CM chondrites that suffered both hydration and heating complicates our understanding of the early thermal evolution of the CM parent body(ies). Here, we provide new constraints on the collisional and thermal history of CM-like bodies from a comparison between newly acquired spectral measurements of main-belt Ch/Cgh-type asteroids (70 objects) and existing laboratory spectral measurements of CM chondrites. It first appears that the spectral variation observed among CM-like bodies is essentially due to variations in the average regolith grain size. Second, the spectral properties of the vast majority (unheated) of CM chondrites resemble both the surfaces and the interiors of CM-like bodies, implying a “low” temperature (<300°C) thermal evolution of the CM parent body(ies). It follows that an impact origin is the likely explanation for the existence of heated CM chondrites. Finally, similarly to S-type asteroids and (2) Pallas, the surfaces of large (D > 100 km)—supposedly primordial—Ch/Cgh-type main-belt asteroids likely expose the interiors of the primordial CM parent bodies, a possible consequence of impacts by small asteroids (D < 10 km) in the early solar system.

  7. Gas-Phase Oxidation of Cm+ and Cm2+ -- Thermodynamics of neutral and ionized CmO

    SciTech Connect

    Gibson, John K; Haire, Richard G.; Santos, Marta; Pires de Matos, Antonio; Marcalo, Joaquim

    2008-12-08

    Fourier transform ion cyclotron resonance mass spectrometry was employed to study the products and kinetics of gas-phase reactions of Cm+ and Cm2+; parallel studies were carried out with La+/2+, Gd+/2+ and Lu+/2+. Reactions with oxygen-donor molecules provided estimates for the bond dissociation energies, D[M+-O](M = Cm, Gd, Lu). The first ionization energy, IE[CmO], was obtained from the reactivity of CmO+ with dienes, and the second ionization energies, IE[MO+](M = Cm, La, Gd, Lu), from the rates of electron-transfer reactions from neutrals to the MO2+ ions. The following thermodynamic quantities for curium oxide molecules were obtained: IE[CmO]= 6.4+-0.2 eV; IE[CmO+]= 15.8+-0.4 eV; D[Cm-O]= 710+-45 kJ mol-1; D[Cm+-O]= 670+-40 kJ mol-1; and D[Cm2+-O]= 342+-55 kJ mol-1. Estimates for the M2+-O bond energies for M = Cm, La, Gd and Lu are all intermediate between D[N2-O]and D[OC-O]--i.e., 167 kJ mol-1< D[M2+-O]< 532 kJ mol-1 -- such that the four MO2+ ions fulfill the thermodynamic requirement for catalytic O-atom transport from N2O to CO. It was demonstrated that the kinetics are also favorable and that the CmO2+, LaO2+, GdO2+ and LuO2+ dipositive ions each catalyze the gas-phase oxidation of CO to CO2 by N2O. The CmO2+ ion appeared during the reaction of Cm+ with O2 when the intermediate, CmO+, was not collisionally cooled -- although its formation is kinetically and/or thermodynamically unfavorable, CmO2+ is a stable species.

  8. Structural and functional changes with depth in microbial communities in a tropical Malaysian peat swamp forest.

    PubMed

    Jackson, Colin R; Liew, Kong Cheng; Yule, Catherine M

    2009-04-01

    Tropical peat swamp forests are important and endangered ecosystems, although little is known of their microbial diversity and ecology. We used molecular and enzymatic techniques to examine patterns in prokaryotic community structure and overall microbial activity at 0-, 10-, 20-, and 50-cm depths in sediments in a peat swamp forest in Malaysia. Denaturing gradient gel electrophoresis profiles of amplified 16S ribosomal ribonucleic acid (rRNA) gene fragments showed that different depths harbored different bacterial assemblages and that Archaea appeared to be limited to the deeper samples. Cloning and sequencing of longer 16S rRNA gene fragments suggested reduced microbial diversity in the deeper samples compared to the surface. Bacterial clone libraries were largely dominated by ribotypes affiliated with the Acidobacteria, which accounted for at least 27-54% of the sequences obtained. All of the sequenced representatives from the archaeal clone libraries were Crenarchaeota. Activities of microbial extracellular enzymes involved in carbon, nitrogen, and phosphorus cycling declined appreciably with depth, the only exception being peroxidase. These results show that tropical peat swamp forests are unusual systems with microbial assemblages dominated by members of the Acidobacteria and Crenarchaeota. Microbial communities show clear changes with depth, and most microbial activity is likely confined to populations in the upper few centimeters, the site of new leaf litter fall, rather than the deeper, older, peat layers.

  9. Morphologies of ˜190,000 Galaxies at z = 0-10 Revealed with HST Legacy Data. I. Size Evolution

    NASA Astrophysics Data System (ADS)

    Shibuya, Takatoshi; Ouchi, Masami; Harikane, Yuichi

    2015-08-01

    We present the redshift evolution of the galaxy effective radius re obtained from the Hubble Space Telescope (HST) samples of ˜190,000 galaxies at z = 0-10. Our HST samples consist of 176,152 photo-z galaxies at z = 0-6 from the 3D-HST+CANDELS catalog and 10,454 Lyman break galaxies (LBGs) at z = 4-10 identified in the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS), HUDF 09/12, and HFF parallel fields, providing the largest data set to date for galaxy size evolution studies. We derive re with the same technique over the wide redshift range of z = 0-10, evaluating the optical-to-UV morphological K correction and the selection bias of photo-z galaxies+LBGs as well as the cosmological surface-brightness dimming effect. We find that re values at a given luminosity significantly decrease toward high z, regardless of statistics choices (e.g., {r}{{e}}\\propto {(1+z)}-1.10+/- 0.06 for median). For star-forming galaxies, there is no evolution of the power-law slope of the size-luminosity relation and the median Sérsic index (n˜ 1.5). Moreover, the re distribution is well represented by log-normal functions whose standard deviation {σ }{ln{r}{{e}}} does not show significant evolution within the range of {σ }{ln{r}{{e}}}˜ 0.45-0.75. We calculate the stellar-to-halo size ratio from our re measurements and the dark-matter halo masses estimated from the abundance-matching study, and we obtain a nearly constant value of {r}{{e}}/{r}{vir}=1.0%-3.5% at z = 0-8. The combination of the re-distribution shape+standard deviation, the constant {r}{{e}}/{r}{vir}, and n˜ 1.5 suggests a picture in which typical high-z star-forming galaxies have disk-like stellar components in a sense of dynamics and morphology over cosmic time of z˜ 0-6. If high-z star-forming galaxies are truly dominated by disks, the {r}{{e}}/{r}{vir} value and the disk-formation model indicate that the specific angular momentum of the disk normalized by the host halo is {j

  10. Carbon amendment and soil depth affect the distribution and abundance of denitrifiers in agricultural soils.

    PubMed

    Barrett, M; Khalil, M I; Jahangir, M M R; Lee, C; Cardenas, L M; Collins, G; Richards, K G; O'Flaherty, V

    2016-04-01

    The nitrite reductase (nirS and nirK) and nitrous oxide reductase-encoding (nosZ) genes of denitrifying populations present in an agricultural grassland soil were quantified using real-time polymerase chain reaction (PCR) assays. Samples from three separate pedological depths at the chosen site were investigated: horizon A (0-10 cm), horizon B (45-55 cm), and horizon C (120-130 cm). The effect of carbon addition (treatment 1, control; treatment 2, glucose-C; treatment 3, dissolved organic carbon (DOC)) on denitrifier gene abundance and N2O and N2 fluxes was determined. In general, denitrifier abundance correlated well with flux measurements; nirS was positively correlated with N2O, and nosZ was positively correlated with N2 (P < 0.03). Denitrifier gene copy concentrations per gram of soil (GCC) varied in response to carbon type amendment (P < 0.01). Denitrifier GCCs were high (ca. 10(7)) and the bac:nirK, bac:nirS, bac:nir (T) , and bac:nosZ ratios were low (ca. 10(-1)/10) in horizon A in all three respective treatments. Glucose-C amendment favored partial denitrification, resulting in higher nir abundance and higher N2O fluxes compared to the control. DOC amendment, by contrast, resulted in relatively higher nosZ abundance and N2 emissions, thus favoring complete denitrification. We also noted soil depth directly affected bacterial, archaeal, and denitrifier abundance, possibly due to changes in soil carbon availability with depth.

  11. Oxygen depth profiling with subnanometre depth resolution

    NASA Astrophysics Data System (ADS)

    Kosmata, Marcel; Munnik, Frans; Hanf, Daniel; Grötzschel, Rainer; Crocoll, Sonja; Möller, Wolfhard

    2014-10-01

    A High-depth Resolution Elastic Recoil Detection (HR-ERD) set-up using a magnetic spectrometer has been taken into operation at the Helmholtz-Zentrum Dresden-Rossendorf for the first time. This instrument allows the investigation of light elements in ultra-thin layers and their interfaces with a depth resolution of less than 1 nm near the surface. As the depth resolution is highly influenced by the experimental measurement parameters, sophisticated optimisation procedures have been implemented. Effects of surface roughness and sample damage caused by high fluences need to be quantified for each kind of material. Also corrections are essential for non-equilibrium charge state distributions that exist very close to the surface. Using the example of a high-k multilayer SiO2/Si3N4Ox/SiO2/Si it is demonstrated that oxygen in ultra-thin films of a few nanometres thickness can be investigated by HR-ERD.

  12. Intensity Mapping During Reionization: 21 cm and Cross-correlations

    NASA Astrophysics Data System (ADS)

    Aguirre, James E.; HERA Collaboration

    2016-01-01

    The first generation of 21 cm epoch of reionization (EoR) experiments are now reaching the sensitivities necessary for a detection of the power spectrum of plausible reionization models, and with the advent of next-generation capabilities (e.g. the Hydrogen Epoch of Reionization Array (HERA) and the Square Kilometer Array Phase I Low) will move beyond the power spectrum to imaging of the EoR intergalactic medium. Such datasets provide context to galaxy evolution studies for the earliest galaxies on scales of tens of Mpc, but at present wide, deep galaxy surveys are lacking, and attaining the depth to survey the bulk of galaxies responsible for reionization will be challenging even for JWST. Thus we seek useful cross-correlations with other more direct tracers of the galaxy population. I review near-term prospects for cross-correlation studies with 21 cm and CO and CII emission, as well as future far-infrared misions suchas CALISTO.

  13. Studies of dished accelerator grids for 30-cm ion thrusters

    NASA Technical Reports Server (NTRS)

    Rawlin, V. K.

    1973-01-01

    Eighteen geometrically different sets of dished accelerator grids were tested on five 30-cm thrusters. The geometric variation of the grids included the grid-to-grid spacing, the screen and accelerator hole diameters and thicknesses, the screen and accelerator open area fractions, ratio of dish depth to dish diameter, compensation, and aperture shape. In general, the data taken over a range of beam currents for each grid set included the minimum total accelerating voltage required to extract a given beam current and the minimum accelerator grid voltage required to prevent electron backstreaming.

  14. Studies of dished accelerator grids for 30-cm ion thrusters

    NASA Technical Reports Server (NTRS)

    Rawlin, V. K.

    1973-01-01

    Geometrically different sets of dished accelerator grids were tested on five 30-cm thrusters. The geometric variation of the grids included the grid-to-grid spacing, the screen and accelerator hole diameters and thicknesses, the screen and accelerator open area fractions, ratio of dish depth to the dish diameter, compensation, and aperture shape. In general, the data taken over a range of beam currents for each grid set included the minimum total accelerating voltage required to extract a given beam current and the minimum accelerator grid voltage required to prevent electron backstreaming.

  15. The effect of drought and interspecific interactions on depth of water uptake in deep- and shallow-rooting grassland species as determined by δ18O natural abundance

    NASA Astrophysics Data System (ADS)

    Hoekstra, N. J.; Finn, J. A.; Hofer, D.; Lüscher, A.

    2014-08-01

    Increased incidence of drought, as predicted under climate change, has the potential to negatively affect grassland production. Compared to monocultures, vertical belowground niche complementarity between shallow- and deep-rooting species may be an important mechanism resulting in higher yields and higher resistance to drought in grassland mixtures. However, very little is known about the belowground responses in grassland systems and increased insight into these processes may yield important information both to predict the effect of future climate change and better design agricultural systems to cope with this. This study assessed the effect of a 9-week experimental summer drought on the depth of water uptake of two shallow-rooting species (Lolium perenne L. and Trifolium repens L.) and two deep-rooting species (Cichorium intybus L. and Trifolium pratense L.) in grassland monocultures and four-species mixtures by using the natural abundance δ18O isotope method. We tested the following three hypotheses: (1) drought results in a shift of water uptake to deeper soil layers, (2) deep-rooting species take up a higher proportion of water from deeper soil layers relative to shallow-rooting species, and (3) as a result of interspecific interactions in mixtures, the water uptake of shallow-rooting species becomes shallower when grown together with deep-rooting species and vice versa, resulting in reduced niche overlap. The natural abundance δ18O technique provided novel insights into the depth of water uptake of deep- and shallow- rooting grassland species and revealed large shifts in depth of water uptake in response to drought and interspecific interactions. Compared to control conditions, drought reduced the proportional water uptake from 0-10 cm soil depth (PCWU0-10) of L. perenne, T. repens and C. intybus in monocultures by on average 54%. In contrast, the PCWU0-10 of T. pratense in monoculture increased by 44%, and only when grown in mixture did the PCWU0-10 of T

  16. Chilled Mirror Dew Point Hygrometer (CM) Handbook

    SciTech Connect

    Ritsche, MT

    2005-01-01

    The CM systems have been developed for the ARM Program to act as a moisture standard traceable to National Institute of Standards and Technology (NIST). There are three CM systems that are each fully portable, self-contained, and require only 110 V AC power. The systems include a CM sensor, air sampling and filtration system, a secondary reference (Rotronic HP043 temperature and relative humidity sensor) to detect system malfunctions, a data acquisition system, and data storage for more than one month of 1-minute data. The CM sensor directly measures dew point temperature at 1 m, air temperature at 2 m, and relative humidity at 2 m. These measurements are intended to represent self-standing data streams that can be used independently or in combinations.

  17. Stereoscopic depth constancy

    PubMed Central

    Guan, Phillip

    2016-01-01

    Depth constancy is the ability to perceive a fixed depth interval in the world as constant despite changes in viewing distance and the spatial scale of depth variation. It is well known that the spatial frequency of depth variation has a large effect on threshold. In the first experiment, we determined that the visual system compensates for this differential sensitivity when the change in disparity is suprathreshold, thereby attaining constancy similar to contrast constancy in the luminance domain. In a second experiment, we examined the ability to perceive constant depth when the spatial frequency and viewing distance both changed. To attain constancy in this situation, the visual system has to estimate distance. We investigated this ability when vergence, accommodation and vertical disparity are all presented accurately and therefore provided veridical information about viewing distance. We found that constancy is nearly complete across changes in viewing distance. Depth constancy is most complete when the scale of the depth relief is constant in the world rather than when it is constant in angular units at the retina. These results bear on the efficacy of algorithms for creating stereo content. This article is part of the themed issue ‘Vision in our three-dimensional world’. PMID:27269596

  18. Stereoscopic depth constancy.

    PubMed

    Guan, Phillip; Banks, Martin S

    2016-06-19

    Depth constancy is the ability to perceive a fixed depth interval in the world as constant despite changes in viewing distance and the spatial scale of depth variation. It is well known that the spatial frequency of depth variation has a large effect on threshold. In the first experiment, we determined that the visual system compensates for this differential sensitivity when the change in disparity is suprathreshold, thereby attaining constancy similar to contrast constancy in the luminance domain. In a second experiment, we examined the ability to perceive constant depth when the spatial frequency and viewing distance both changed. To attain constancy in this situation, the visual system has to estimate distance. We investigated this ability when vergence, accommodation and vertical disparity are all presented accurately and therefore provided veridical information about viewing distance. We found that constancy is nearly complete across changes in viewing distance. Depth constancy is most complete when the scale of the depth relief is constant in the world rather than when it is constant in angular units at the retina. These results bear on the efficacy of algorithms for creating stereo content.This article is part of the themed issue 'Vision in our three-dimensional world'.

  19. Detection of Thermal 2 cm and 1 cm Formaldehyde Emission in NGC 7538

    NASA Astrophysics Data System (ADS)

    Yuan, Liang; Araya, E. D.; Hofner, P.; Kurtz, S.; Pihlstrom, Y.

    2011-05-01

    Formaldehyde is a tracer of high density gas in massive star forming regions. The K-doublet lines from the three lowest rotational energy levels of ortho-formaldehyde correspond to wavelengths of 6, 2 and 1 cm. Thermal emission of these transitions is rare, and maser emission has only been detected in the 6 cm line. NGC 7538 is an active site of massive star formation in the Galaxy, and one of only a few regions known to harbor 6 cm formaldehyde (H2CO) masers. Using the NRAO 100 m Green Bank Telescope (GBT), we detected 2 cm H2CO emission toward NGC 7538 IRS1. The velocity of the 2 cm H2CO line is very similar to the velocity of one of the 6 cm H2CO masers but the linewidth is greater. To investigate the nature of the 2 cm emission, we conducted observations of the 1 cm H2CO transition, and obtained a cross-scan map of the 2 cm line. We detected 1 cm emission and found that the 2 cm emission is extended (greater than 30"), which implies brightness temperatures of ˜0.2 K. Assuming optically thin emission, LTE, and that the 1 cm and 2 cm lines originate from the same volume of gas, both these detections are consistent with thermal emission of gas at ˜30 K. We conclude that the 1 cm and 2 cm H2CO lines detected with the GBT are thermal, which implies molecular densities above ˜105 cm-3. LY acknowledges support from WIU. PH acknowledges partial support from NSF grant AST-0908901.

  20. Probing lepton asymmetry with 21 cm fluctuations

    SciTech Connect

    Kohri, Kazunori; Oyama, Yoshihiko; Sekiguchi, Toyokazu; Takahashi, Tomo E-mail: oyamayo@post.kek.jp E-mail: tomot@cc.saga-u.ac.jp

    2014-09-01

    We investigate the issue of how accurately we can constrain the lepton number asymmetry ξ{sub ν}=μ{sub ν}/T{sub ν} in the Universe by using future observations of 21 cm line fluctuations and cosmic microwave background (CMB). We find that combinations of the 21 cm line and the CMB observations can constrain the lepton asymmetry better than big-bang nucleosynthesis (BBN). Additionally, we also discuss constraints on ξ{sub ν} in the presence of some extra radiation, and show that the 21 cm line observations can substantially improve the constraints obtained by CMB alone, and allow us to distinguish the effects of the lepton asymmetry from the ones of extra radiation.

  1. Motivation with Depth.

    ERIC Educational Resources Information Center

    DiSpezio, Michael A.

    2000-01-01

    Presents an illusional arena by offering experience in optical illusions in which students must apply critical analysis to their innate information gathering systems. Introduces different types of depth illusions for students to experience. (ASK)

  2. CV and CM chondrite impact melts

    NASA Astrophysics Data System (ADS)

    Lunning, Nicole G.; Corrigan, Catherine M.; McSween, Harry Y.; Tenner, Travis J.; Kita, Noriko T.; Bodnar, Robert J.

    2016-09-01

    Volatile-rich and typically oxidized carbonaceous chondrites, such as CV and CM chondrites, potentially respond to impacts differently than do other chondritic materials. Understanding impact melting of carbonaceous chondrites has been hampered by the dearth of recognized impact melt samples. In this study we identify five carbonaceous chondrite impact melt clasts in three host meteorites: a CV3red chondrite, a CV3oxA chondrite, and a regolithic howardite. The impact melt clasts in these meteorites respectively formed from CV3red chondrite, CV3oxA chondrite, and CM chondrite protoliths. We identified these impact melt clasts and interpreted their precursors based on their texture, mineral chemistry, silicate bulk elemental composition, and in the case of the CM chondrite impact melt clast, in situ measurement of oxygen three-isotope signatures in olivine. These impact melts typically contain euhedral-subhedral olivine microphenocrysts, sometimes with relict cores, in glassy groundmasses. Based on petrography and Raman spectroscopy, four of the impact melt clasts exhibit evidence for volatile loss: these melt clasts either contain vesicles or are depleted in H2O relative to their precursors. Volatile loss (i.e., H2O) may have reduced the redox state of the CM chondrite impact melt clast. The clasts that formed from the more oxidized precursors (CV3oxA and CM chondrites) exhibit phase and bulk silicate elemental compositions consistent with higher intrinsic oxygen fugacities relative to the clast that formed from a more reduced precursor (CV3red chondrite). The mineral chemistries and assemblages of the CV and CM chondrite impact melt clasts identified here provide a template for recognizing carbonaceous chondrite impact melts on the surfaces of asteroids.

  3. Depth Optimization Study

    DOE Data Explorer

    Kawase, Mitsuhiro

    2009-11-22

    The zipped file contains a directory of data and routines used in the NNMREC turbine depth optimization study (Kawase et al., 2011), and calculation results thereof. For further info, please contact Mitsuhiro Kawase at kawase@uw.edu. Reference: Mitsuhiro Kawase, Patricia Beba, and Brian Fabien (2011), Finding an Optimal Placement Depth for a Tidal In-Stream Conversion Device in an Energetic, Baroclinic Tidal Channel, NNMREC Technical Report.

  4. Carbon storage potential in size-density fractions from semi-natural grassland ecosystems with different productivities over varying soil depths.

    PubMed

    Breulmann, Marc; Boettger, Tatjana; Buscot, François; Gruendling, Ralf; Schulz, Elke

    2016-03-01

    Researchers have increasingly recognised a profound need for more information on SOC stocks in the soil and the factors governing their stability and dynamics. Many questions still remain unanswered about the interplay between changes in plant communities and the extent to which changes in aboveground productivity affect the carbon dynamics in soils through changes in its quantity and quality. Therefore, the main aim of this research was to examine the SOC accumulation potential of semi-natural grasslands of different productivities and determine the distribution of SOM fractions over varying soil depth intervals (0-10, 10-20, 20-30 30-50 50-80 and 80+cm). SOM fractionation was considered as a relative measure of stability to separate SOM associated with clay minerals from SOM of specific light densities less than 2 g cm(-3) (size-density fractionation). Two clay-associated fractions (CF1, <1 μm; and CF2, 1-2 μm) and two light fractions (LF1, <1.8 g cm(-3); and LF2, 1.8-2.0 g cm(-3)) were separated. The stability of these fractions was characterised by their carbon hot water extractability (CHWE) and stable carbon isotope composition. In the semi-natural grasslands studied, most OC was stored in the top 30 cm, where turnover is rapid. Effects of low productivity grasslands became only significantly apparent when fractional OC contributions of total SOM was considered (CF1 and LF1). In deeper soil depths OC was largely attributed to the CF1 fraction of low productivity grasslands. We suggest that the majority of OM in deeper soil depth intervals is microbially-derived, as evidenced by decreasing C/N ratios and decreasing δ(13)C values. The hot water extraction and natural δ(13)C abundance, employed here allowed the characterisation of SOM stabilisation properties, however how climatic changes affect the fate of OM within different soil depth intervals is still unknown.

  5. Characterization of 8-cm engineering model thruster

    NASA Technical Reports Server (NTRS)

    Williamson, W. S.

    1984-01-01

    Development of 8 cm ion thruster technology which was conducted in support of the Ion Auxiliary Propulsion System (IAPS) flight contract (Contract NAS3-21055) is discussed. The work included characterization of thruster performance, stability, and control; a study of the effects of cathode aging; environmental qualification testing; and cyclic lifetesting of especially critical thruster components.

  6. The Multidimensional Curriculum Model (MdCM)

    ERIC Educational Resources Information Center

    Vidergor, Hava E.

    2010-01-01

    The multidimensional Curriculum Model (MdCM) helps teachers to better prepare gifted and able students for our changing world, acquiring much needed skills. It is influenced by general learning theory of constructivism, notions of preparing students for 21st century, Teaching the Future Model, and current comprehensive curriculum models for…

  7. Double-exposure strategy using OPC and simulation and the performance on wafer with sub-0.10-μm design rule in ArF lithography

    NASA Astrophysics Data System (ADS)

    Oh, Se-Young; Kim, Wan-Ho; Yune, Hyoung-Soon; Kim, Hee-Bom; Kim, Seo-Min; Ahn, Chang-Nam; Shin, Ki-Soo

    2002-07-01

    , registration between two stitched regions and stitching itself in the boundary. It is found from the experiment that total DOF of DE (double exposure) is 0.5 um and the total EL of DE is 10.0% in this paper. At present, it is very difficult to ensure stable process margin for the sub-0.10 um patterning. But there is a promising technology called stitching with special optimization. In addition, this technology will be nominated as an eternal candidate process whenever our lithography is in the adversity at the limits of his days.

  8. Interpreting Sky-Averaged 21-cm Measurements

    NASA Astrophysics Data System (ADS)

    Mirocha, Jordan

    2015-01-01

    Within the first ~billion years after the Big Bang, the intergalactic medium (IGM) underwent a remarkable transformation, from a uniform sea of cold neutral hydrogen gas to a fully ionized, metal-enriched plasma. Three milestones during this epoch of reionization -- the emergence of the first stars, black holes (BHs), and full-fledged galaxies -- are expected to manifest themselves as extrema in sky-averaged ("global") measurements of the redshifted 21-cm background. However, interpreting these measurements will be complicated by the presence of strong foregrounds and non-trivialities in the radiative transfer (RT) modeling required to make robust predictions.I have developed numerical models that efficiently solve the frequency-dependent radiative transfer equation, which has led to two advances in studies of the global 21-cm signal. First, frequency-dependent solutions facilitate studies of how the global 21-cm signal may be used to constrain the detailed spectral properties of the first stars, BHs, and galaxies, rather than just the timing of their formation. And second, the speed of these calculations allows one to search vast expanses of a currently unconstrained parameter space, while simultaneously characterizing the degeneracies between parameters of interest. I find principally that (1) physical properties of the IGM, such as its temperature and ionization state, can be constrained robustly from observations of the global 21-cm signal without invoking models for the astrophysical sources themselves, (2) translating IGM properties to galaxy properties is challenging, in large part due to frequency-dependent effects. For instance, evolution in the characteristic spectrum of accreting BHs can modify the 21-cm absorption signal at levels accessible to first generation instruments, but could easily be confused with evolution in the X-ray luminosity star-formation rate relation. Finally, (3) the independent constraints most likely to aide in the interpretation

  9. Balloon observations of the radiance of the earth between 2100 cm(-1) and 2700 cm(-1).

    PubMed

    Shaw, J H; McClatchey, R A; Schaper, P W

    1967-02-01

    A grating spectrometer capable of measuring small radiation fluxes with a spectral resolution of 95 at 4.3 micro is described. Bands of CO(2), N(2)O, and O(3) are identified in spectra between 2100 cm(-1) and 2700 cm(-1) of the earth and lower atmosphere obtained from an altitude of 30 km with this instrument. Scattering of solar radiation by clouds was observed between 2400 cm(-1) and 2700 cm(-1). A temperature profile of the atmosphere to 30 km determined from an analysis of the measurements in the region of the 4.3 micro CO(2) band is compared with radiosonde observations made during the flight.

  10. Hydrogen-Broadened Water from 50 to 300 cm-1 and 1300 to 4000 cm-1

    NASA Technical Reports Server (NTRS)

    Brown, L.; Peterson, D.; Plymate, C.

    1995-01-01

    To support remote sensing of the outer planets, absorption spectra of H2O broadened by H2 were recorded at room temperature using two Fourier transform spectrometers. The data from 1300 to 4000 cm-1 were obtained at 0.012 cm-1 resolution with the McMath FTS located at Kitt Peak National Observatory/National Solar Observatory. The remainder of the spectral data from 55 to 320 cm-1 were taken at 0.0056 cm-1 with the Bruker FTS.

  11. Magnetic susceptibility of curium pnictides. [/sup 248/CmP, /sup 248/CmSb

    SciTech Connect

    Nave, S.E.; Huray, P.G.; Peterson, J.R.; Damien, D.A.; Haire, R.G.

    1981-09-01

    The magnetic susceptibility of microgram quantities of /sup 248/CmP and /sup 248/CmSb has been determined with the use of a SQUID micromagnetic susceptometer over the temperature range 4.2 to 340 K and in the applied magnetic field range of 0.45 to 1600 G. The fcc (NaCl-type) samples yield magnetic transitions at 73K and 162 K for the phosphide and antimonide, respectively. Together with published magnetic data for CmN and CmAs, these results indicate spatially extended exchange interactions between the relatively localized 5f electrons of the metallic actinide atoms.

  12. Extended Performance 8-cm Mercury Ion Thruster

    NASA Technical Reports Server (NTRS)

    Mantenieks, M. A.

    1981-01-01

    A slightly modified 8-cm Hg ion thruster demonstrated significant increase in performance. Thrust was increased by almost a factor of five over that of the baseline thruster. Thruster operation with various three grid ion optics configurations; thruster performance as a function of accelerator grid open area, cathode baffle, and cathode orifice size; and a life test of 614 hours at a beam current of 250 mA (17.5 mN thrust) are discussed. Highest thruster efficiency was obtained with the smallest open area accelerator grid. The benefits in efficiency from the low neutral loss grids were mitigated, however, by the limitation such grids place on attainable ion beam current densities. The thruster components suffered negligible weight losses during a life test, which indicated that operation of the 8-cm thruster at extended levels of thrust and power is possible with no significant loss of lifetime.

  13. Depth profiles of methane oxidation potentials and methanotrophic community in a lab-scale biocover.

    PubMed

    Lee, Eun-Hee; Moon, Kyung-Eun; Kim, Tae Gwan; Cho, Kyung-Suk

    2014-08-20

    The depth profiles of the CH4 oxidation potentials and the methanotrophic community were characterized in a lab-scale soil mixture biocover. The soil mixture samples were collected from the top (0-10cm), middle (10-40cm), and bottom (40-50cm) layers of the biocover where most of methane was oxidized at the top layer due to consumption of O2. Batch tests using serum bottles showed that the middle and bottom samples displayed CH4 oxidation activity under aerobic conditions, and their CH4 oxidation rates were 85 and 71% of the rate of top sample (8.40μmolgdry sample(-1)h(-1)), respectively. The numbers of methanotrophs in the middle and bottom were not significantly different from those in the top sample. There was no statistical difference in the community stability indices (diversity and evenness) among the methanotrophic communities of the three layer samples, even though the community structures were distinguished from each other. Based on microarray analysis, type I and type II methanotrophs were equally present in the top sample, while type I was more dominant than type II in the middle and bottom samples. We suggested that the qualitative difference in the community structures was probably caused by the difference in the depth profiles of the CH4 and O2 concentrations. The results for the CH4 oxidation potential, methanotrophic biomass, and community stability indices in the middle and bottom layer samples indicated that the deeper layer in the methanotrophic biocover serves as a bioresource reservoir for sustainable CH4 mitigation.

  14. 15 cm multipole gas ion thruster

    NASA Technical Reports Server (NTRS)

    Isaacson, G. C.; Kaufman, H. R.

    1976-01-01

    A 15-cm multipole thruster was operated on argon and xenon. The multipole approach used has been shown capable of low discharge losses and flat ion beam profiles with a minimum of redesign. This approach employs low magnetic field strengths and flat or cylindrical sheet-metal parts, hence is suited to rapid optimization and scaling. Only refractory metal cathodes were used in this investigation.

  15. Late type close binary system CM Dra

    NASA Astrophysics Data System (ADS)

    Kalomeni, Belinda

    2015-08-01

    In this study, we present new observations of the close binary system CM Dra. We analyzed all the available data of the system and estimated the physical parameters of the system stars highly accurately. Using the newly obtained parameters the distance of the system is determined to be 11.6 pc. A possible giant planet orbiting the close binary system has been detected. This orbital period would likely make it one of the longest known orbital period planet.

  16. Constraining dark matter through 21-cm observations

    NASA Astrophysics Data System (ADS)

    Valdés, M.; Ferrara, A.; Mapelli, M.; Ripamonti, E.

    2007-05-01

    Beyond reionization epoch cosmic hydrogen is neutral and can be directly observed through its 21-cm line signal. If dark matter (DM) decays or annihilates, the corresponding energy input affects the hydrogen kinetic temperature and ionized fraction, and contributes to the Lyα background. The changes induced by these processes on the 21-cm signal can then be used to constrain the proposed DM candidates, among which we select the three most popular ones: (i) 25-keV decaying sterile neutrinos, (ii) 10-MeV decaying light dark matter (LDM) and (iii) 10-MeV annihilating LDM. Although we find that the DM effects are considerably smaller than found by previous studies (due to a more physical description of the energy transfer from DM to the gas), we conclude that combined observations of the 21-cm background and of its gradient should be able to put constrains at least on LDM candidates. In fact, LDM decays (annihilations) induce differential brightness temperature variations with respect to the non-decaying/annihilating DM case up to ΔδTb = 8 (22) mK at about 50 (15) MHz. In principle, this signal could be detected both by current single-dish radio telescopes and future facilities as Low Frequency Array; however, this assumes that ionospheric, interference and foreground issues can be properly taken care of.

  17. Polyhedral Serpentine Grains in CM Chondrites

    NASA Technical Reports Server (NTRS)

    Zega, Thomas J.; Garvie, Laurence A. J.; Dodony, Istvan; Stroud, Rhonda M.; Buseck, Peter R.

    2005-01-01

    CM chondrites are primitive rocks that experienced aqueous alteration in the early solar system. Their matrices and fine-grained rims (FGRs) sustained the effects of alteration, and the minerals within them hold clues to the aqueous reactions. Sheet silicates are an important product of alteration, and those of the serpentine group are abundant in the CM2 chondrites. Here we expand on our previous efforts to characterize the structure and chemistry of serpentines in CM chondrites and report results on a polyhedral form that is structurally similar to polygonal serpentine. Polygonal serpentine consists of tetrahedral (T) sheets joined to M(2+)-centered octahedral (O) sheets (where (M2+) is primarily Mg(2+) and Fe(2+)), which give rise to a 1:1 (TO) layered structure with a 0.7-nm layer periodicity. The structure is similar to chrysotile in that it consists of concentric lizardite layers wrapped around the fiber axis. However, unlike the rolled-up chrysotile, the tetrahedral sheets of the lizardite layers are periodically inverted and kinked, producing sectors. The relative angles between sectors result in 15- and 30-sided polygons in terrestrial samples.

  18. Decay Data Evaluation Project (DDEP): evaluation of the main 243Cm and 245Cm decay characteristics.

    PubMed

    Chechev, Valery P

    2012-09-01

    The results of new decay data evaluations are presented for (243)Cm (α) decay to nuclear levels in (239)Pu and (245)Cm (α) decay to nuclear levels in (241)Pu. These evaluated data have been obtained within the Decay Data Evaluation Project using information published up to 2011.

  19. A young region on Enceladus revealed by 2 cm radiometry?

    NASA Astrophysics Data System (ADS)

    Ries, P.; Janssen, M.

    2014-04-01

    On 5 November 2011, the Cassini spacecraft had a flyby of Enceladus dedicated to its synthetic aperture radar (SAR) instrument. In the course of that flyby, approximately 80% of Enceladus' surface was also observed serendipitously with the microwave radiometer operating concurrently at 2.2 cm. The radiometry data is analyzed and shown to drop sharply in the leading hemisphere's smooth terrain. This drop is also demonstrated in a series of unresolved distant radiometry measurements spread out over the ten years of the Cassini mission. However, the anomaly is absent from distant unresolved RADAR measurements and not visible in SAR imaging. The anomaly is most likely caused by a young surface (<100MYr in age) which has not yet been processed by micrometeoroid impacts below the electromagnetic skin depth (3 m).

  20. An engineering model 30 cm ion thruster

    NASA Technical Reports Server (NTRS)

    Poeschel, R. L.; King, H. J.; Schnelker, D. E.

    1973-01-01

    Thruster development at Hughes Research Laboratories and NASA Lewis Research Center has brought the 30-cm mercury bombardment ion thruster to the state of an engineering model. This thruster has been designed to have sufficient internal strength for direct mounting on gimbals, to weigh 7.3 kg, to operate with a corrected overall efficiency of 71%, and to have 10,000 hours lifetime. Subassemblies, such as the ion optical system, isolators, etc., have been upgraded to meet launch qualification standards. This paper presents a summary of the design specifications and performance characteristics which define the interface between the thruster module and the remainder of the propulsion system.

  1. Magneto-transport studies on Bi2Te2+xSe1-x (x = 0.05 and 0.10) topological insulators

    NASA Astrophysics Data System (ADS)

    Irfan, Bushra; Chatterjee, Ratnamala

    2016-09-01

    Bi2Te2Se is one of the most promising three dimensional topological insulators, for the study of surface states. In this work, we report the results of transport and magneto-transport behavior of Bi2Te2+xSe1-x (x =0.05 and 0.10) single crystals grown using modified Bridgeman technique. Resistance versus temperature measurements show semiconducting behavior for x = 0.05 and 0.10 crystals. Linear magnetoresistance is observed for Bi2Te2.05Se0.95 (i.e. x =0.05 ) whereas, Bi2Te2.10Se0.90 (x =0.10 ) single crystal shows a conductance fluctuations at low magnetic field.

  2. Redundant Array Configurations for 21 cm Cosmology

    NASA Astrophysics Data System (ADS)

    Dillon, Joshua S.; Parsons, Aaron R.

    2016-08-01

    Realizing the potential of 21 cm tomography to statistically probe the intergalactic medium before and during the Epoch of Reionization requires large telescopes and precise control of systematics. Next-generation telescopes are now being designed and built to meet these challenges, drawing lessons from first-generation experiments that showed the benefits of densely packed, highly redundant arrays—in which the same mode on the sky is sampled by many antenna pairs—for achieving high sensitivity, precise calibration, and robust foreground mitigation. In this work, we focus on the Hydrogen Epoch of Reionization Array (HERA) as an interferometer with a dense, redundant core designed following these lessons to be optimized for 21 cm cosmology. We show how modestly supplementing or modifying a compact design like HERA’s can still deliver high sensitivity while enhancing strategies for calibration and foreground mitigation. In particular, we compare the imaging capability of several array configurations, both instantaneously (to address instrumental and ionospheric effects) and with rotation synthesis (for foreground removal). We also examine the effects that configuration has on calibratability using instantaneous redundancy. We find that improved imaging with sub-aperture sampling via “off-grid” antennas and increased angular resolution via far-flung “outrigger” antennas is possible with a redundantly calibratable array configuration.

  3. THE METALLICITY OF THE CM DRACONIS SYSTEM

    SciTech Connect

    Terrien, Ryan C.; Fleming, Scott W.; Mahadevan, Suvrath; Deshpande, Rohit; Bender, Chad F.; Ramsey, Lawrence W.; Feiden, Gregory A.

    2012-11-20

    The CM Draconis system comprises two eclipsing mid-M dwarfs of nearly equal mass in a 1.27 day orbit. This well-studied eclipsing binary has often been used for benchmark tests of stellar models, since its components are among the lowest mass stars with well-measured masses and radii ({approx}< 1% relative precision). However, as with many other low-mass stars, non-magnetic models have been unable to match the observed radii and effective temperatures for CM Dra at the 5%-10% level. To date, the uncertain metallicity of the system has complicated comparison of theoretical isochrones with observations. In this Letter, we use data from the SpeX instrument on the NASA Infrared Telescope Facility to measure the metallicity of the system during primary and secondary eclipses, as well as out of eclipse, based on an empirical metallicity calibration in the H and K near-infrared (NIR) bands. We derive an [Fe/H] = -0.30 {+-} 0.12 that is consistent across all orbital phases. The determination of [Fe/H] for this system constrains a key dimension of parameter space when attempting to reconcile model isochrone predictions and observations.

  4. Combining galaxy and 21-cm surveys

    NASA Astrophysics Data System (ADS)

    Cohn, J. D.; White, Martin; Chang, Tzu-Ching; Holder, Gil; Padmanabhan, Nikhil; Doré, Olivier

    2016-04-01

    Acoustic waves travelling through the early Universe imprint a characteristic scale in the clustering of galaxies, QSOs and intergalactic gas. This scale can be used as a standard ruler to map the expansion history of the Universe, a technique known as baryon acoustic oscillations (BAO). BAO offer a high-precision, low-systematics means of constraining our cosmological model. The statistical power of BAO measurements can be improved if the `smearing' of the acoustic feature by non-linear structure formation is undone in a process known as reconstruction. In this paper, we use low-order Lagrangian perturbation theory to study the ability of 21-cm experiments to perform reconstruction and how augmenting these surveys with galaxy redshift surveys at relatively low number densities can improve performance. We find that the critical number density which must be achieved in order to benefit 21-cm surveys is set by the linear theory power spectrum near its peak, and corresponds to densities achievable by upcoming surveys of emission line galaxies such as eBOSS and DESI. As part of this work, we analyse reconstruction within the framework of Lagrangian perturbation theory with local Lagrangian bias, redshift-space distortions, {k}-dependent noise and anisotropic filtering schemes.

  5. The Metallicity of the CM Draconis System

    NASA Astrophysics Data System (ADS)

    Terrien, Ryan C.; Fleming, Scott W.; Mahadevan, Suvrath; Deshpande, Rohit; Feiden, Gregory A.; Bender, Chad F.; Ramsey, Lawrence W.

    2012-11-01

    The CM Draconis system comprises two eclipsing mid-M dwarfs of nearly equal mass in a 1.27 day orbit. This well-studied eclipsing binary has often been used for benchmark tests of stellar models, since its components are among the lowest mass stars with well-measured masses and radii (lsim 1% relative precision). However, as with many other low-mass stars, non-magnetic models have been unable to match the observed radii and effective temperatures for CM Dra at the 5%-10% level. To date, the uncertain metallicity of the system has complicated comparison of theoretical isochrones with observations. In this Letter, we use data from the SpeX instrument on the NASA Infrared Telescope Facility to measure the metallicity of the system during primary and secondary eclipses, as well as out of eclipse, based on an empirical metallicity calibration in the H and K near-infrared (NIR) bands. We derive an [Fe/H] = -0.30 ± 0.12 that is consistent across all orbital phases. The determination of [Fe/H] for this system constrains a key dimension of parameter space when attempting to reconcile model isochrone predictions and observations.

  6. Fuel elements of research reactor CM

    SciTech Connect

    Kozlov, A.V.; Morozov, A.V.; Vatulin, A.V.; Ershov, S.A.

    2013-07-01

    In 1961 the CM research reactor was commissioned at the Research Institute of Atomic Reactors (Dimitrovgrad, Russia), it was intended to carry on investigations and the production of transuranium nuclides. The reactor is of a tank type. Original fuel assembly contained plate fuels that were spaced with vanes and corrugated bands. Nickel was used as a cladding material, fuel meat was produced from UO{sub 2} + electrolytic nickel composition. Fuel plates have been replaced by self-spacing cross-shaped dispersion fuels clad in stainless steel. In 2005 the reactor was updated. The purpose of this updating was to increase the quantity of irradiation channels in the reactor core and to improve the neutron balance. The updating was implemented at the expense of 20 % reduction in the quantity of fuel elements in the core which released a space for extra channels and decreased the mass of structural materials in the core. The updated reactor is loaded with modified standard fuel elements with 20 % higher uranium masses. At the same time stainless steel in fuel assembly shrouds was substituted by zirconium alloy. Today in progress are investigations and work to promote the second stage of reactor updating that involve developments of cross-shaped fuel elements having low neutron absorption matrix materials. This article gives an historical account of the design and main technical changes that occurred for the CM reactor since its commissioning.

  7. Aliphatic amines in Antarctic CR2, CM2, and CM1/2 carbonaceous chondrites

    NASA Astrophysics Data System (ADS)

    Aponte, José C.; McLain, Hannah L.; Dworkin, Jason P.; Elsila, Jamie E.

    2016-09-01

    Meteoritic water-soluble organic compounds provide a unique record of the processes that occurred during the formation of the solar system and the chemistry preceding the origins of life on Earth. We have investigated the molecular distribution, compound-specific δ13C isotopic ratios and enantiomeric compositions of aliphatic monoamines present in the hot acid-water extracts of the carbonaceous chondrites LAP 02342 (CR2), GRA 95229 (CR2), LON 94101 (CM2), LEW 90500 (CM2), and ALH 83100 (CM1/2). Analyses of the concentration of monoamines in these meteorites revealed: (a) the CR2 chondrites studied here contain higher concentrations of monoamines relative to the analyzed CM2 chondrites; (b) the concentration of monoamines decreases with increasing carbon number; and (c) isopropylamine is the most abundant monoamine in these CR2 chondrites, while methylamine is the most abundant amine species in these CM2 and CM1/2 chondrites. The δ13C values of monoamines in CR2 chondrite do not correlate with the number of carbon atoms; however, in CM2 and CM1/2 chondrites, the 13C enrichment decreases with increasing monoamine carbon number. The δ13C values of methylamine in CR2 chondrites ranged from -1 to +10‰, while in CM2 and CM1/2 chondrites the δ13C values of methylamine ranged from +41 to +59‰. We also observed racemic compositions of sec-butylamine, 3-methyl-2-butylamine, and sec-pentylamine in the studied carbonaceous chondrites. Additionally, we compared the abundance and δ13C isotopic composition of monoamines to those of their structurally related amino acids. We found that monoamines are less abundant than amino acids in CR2 chondrites, with the opposite being true in CM2 and CM1/2 chondrites. We used these collective data to evaluate different primordial synthetic pathways for monoamines in carbonaceous chondrites and to understand the potential common origins these molecules may share with meteoritic amino acids.

  8. Burn Depth Monitor

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Supra Medical Systems is successfully marketing a device that detects the depth of burn wounds in human skin. To develop the product, the companyused technology developed by NASA Langley physicists looking for better ultrasonic detection of small air bubbles and cracks in metal. The device is being marketed to burn wound analysis and treatment centers. Through a Space Act agreement, NASA and the company are also working to further develop ultrasonic instruments for new medical applications.

  9. Burn Depth Monitor

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Supra Medical Systems is successfully marketing a device that detects the depth of burn wounds in human skin. To develop the product, the company used technology developed by NASA Langley physicists looking for better ultrasonic detection of small air bubbles and cracks in metal. The device is being marketed to burn wound analysis and treatment centers. Through a Space Act agreement, NASA and the company are also working to further develop ultrasonic instruments for new medical applications

  10. Burn Depth Monitor

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Supra Medical Systems is successfully marketing a device that detects the depth of burn wounds in human skin. To develop the product, the company used technology developed by NASA Langley physicists looking for better ultrasonic detection of small air bubbles and cracks in metal. The device is being marketed to burn wound analysis and treatment centers. Through a Space Act agreement, NASA and the company are also working to further develop ultrasonic instruments for new medical applications.

  11. Variable depth core sampler

    DOEpatents

    Bourgeois, P.M.; Reger, R.J.

    1996-02-20

    A variable depth core sampler apparatus is described comprising a first circular hole saw member, having longitudinal sections that collapses to form a point and capture a sample, and a second circular hole saw member residing inside said first hole saw member to support the longitudinal sections of said first hole saw member and prevent them from collapsing to form a point. The second hole saw member may be raised and lowered inside said first hole saw member. 7 figs.

  12. Variable depth core sampler

    DOEpatents

    Bourgeois, Peter M.; Reger, Robert J.

    1996-01-01

    A variable depth core sampler apparatus comprising a first circular hole saw member, having longitudinal sections that collapses to form a point and capture a sample, and a second circular hole saw member residing inside said first hole saw member to support the longitudinal sections of said first hole saw member and prevent them from collapsing to form a point. The second hole saw member may be raised and lowered inside said first hole saw member.

  13. Probing patchy reionization through τ-21 cm correlation statistics

    SciTech Connect

    Meerburg, P. Daniel; Spergel, David N.; Dvorkin, Cora E-mail: dns@astro.princeton.edu

    2013-12-20

    We consider the cross-correlation between free electrons and neutral hydrogen during the epoch of reionization (EoR). The free electrons are traced by the optical depth to reionization τ, while the neutral hydrogen can be observed through 21 cm photon emission. As expected, this correlation is sensitive to the detailed physics of reionization. Foremost, if reionization occurs through the merger of relatively large halos hosting an ionizing source, the free electrons and neutral hydrogen are anticorrelated for most of the reionization history. A positive contribution to the correlation can occur when the halos that can form an ionizing source are small. A measurement of this sign change in the cross-correlation could help disentangle the bias and the ionization history. We estimate the signal-to-noise ratio of the cross-correlation using the estimator for inhomogeneous reionization τ-hat {sub ℓm} proposed by Dvorkin and Smith. We find that with upcoming radio interferometers and cosmic microwave background (CMB) experiments, the cross-correlation is measurable going up to multipoles ℓ ∼ 1000. We also derive parameter constraints and conclude that, despite the foregrounds, the cross-correlation provides a complementary measurement of the EoR parameters to the 21 cm and CMB polarization autocorrelations expected to be observed in the coming decade.

  14. Variable depth core sampler

    SciTech Connect

    Bourgeois, P.M.; Reger, R.J.

    1994-12-31

    This invention relates to a sampling means, more particularly to a device to sample hard surfaces at varying depths. Often it is desirable to take samples of a hard surface wherein the samples are of the same diameter but of varying depths. Current practice requires that a full top-to-bottom sample of the material be taken, using a hole saw, and boring a hole from one end of the material to the other. The sample thus taken is removed from the hole saw and the middle of said sample is then subjected to further investigation. This paper describes a variable depth core sampler comprimising a circular hole saw member, having longitudinal sections that collapse to form a point and capture a sample, and a second saw member residing inside the first hole saw member to support the longitudinal sections of the first member and prevent them from collapsing to form a point. The second hole saw member may be raised and lowered inside the the first hole saw member.

  15. Phosphogypsum capping depth affects revegetation and hydrology in Western Canada.

    PubMed

    Jackson, Mallory E; Naeth, M Anne; Chanasyk, David S; Nichol, Connie K

    2011-01-01

    Phosphogypsum (PG), a byproduct of phosphate fertilizer manufacturing, is commonly stacked and capped with soil at decommissioning. Shallow (0, 8, 15, and 30 cm) and thick (46 and 91 cm) sandy loam caps on a PG stack near Fort Saskatchewan, Alberta, Canada, were studied in relation to vegetation establishment and hydrologic properties. Plant response was evaluated over two growing seasons for redtop ( L.), slender wheatgrass ( (Link) Malte ex H.F. Lewis), tufted hairgrass ( (L.) P. Beauv.), and sheep fescue ( L.) and for a mix of these grasses with alsike clover ( L.). Water content below the soil-PG interface was monitored with time-domain reflectometry probes, and leachate water quantity and quality at a depth of 30 cm was measured using lysimeters. Vegetation responded positively to all cap depths relative to bare PG, with few significant differences among cap depths. Slender wheatgrass performed best, and tufted hairgrass performed poorly. Soil caps <1 m required by regulation were sufficient for early revegetation. Soil water fluctuated more in shallow than in thick caps, and water content was generally between field capacity and wilting point regardless of cap depth. Water quality was not affected by cap depths ≤30 cm. Leachate volumes at 30 cm from distinct rainfall events were independent of precipitation amount and cap depth. The study period had lower precipitation than normal, yet soil caps were hospitable for plant growth in the first 2 yr of establishment.

  16. Overcoming the Challenges of 21cm Cosmology

    NASA Astrophysics Data System (ADS)

    Pober, Jonathan

    The highly-redshifted 21cm line of neutral hydrogen is one of the most promising and unique probes of cosmology for the next decade and beyond. The past few years have seen a number of dedicated experiments targeting the 21cm signal from the Epoch of Reionization (EoR) begin operation, including the LOw-Frequency ARray (LOFAR), the Murchison Widefield Array (MWA), and the Donald C. Backer Precision Array for Probing the Epoch of Reionization (PAPER). For these experiments to yield cosmological results, they require new calibration and analysis algorithms which will need to achieve unprecedented levels of separation between the 21cm signal and contaminating foreground emission. Although much work has been spent developing these algorithms over the past decade, their success or failure will ultimately depend on their ability to overcome the complications associated with real-world systems and their inherent complications. The work in this dissertation is closely tied to the late-stage commissioning and early observations with PAPER. The first two chapters focus on developing calibration algorithms to overcome unique problems arising in the PAPER system. To test these algorithms, I rely on not only simulations, but on commissioning observations, ultimately tying the success of the algorithm to its performance on actual, celestial data. The first algorithm works to correct gain-drifts in the PAPER system caused by the heating and cooling of various components (the amplifiers and above ground co-axial cables, in particular). It is shown that a simple measurement of the ambient temperature can remove ˜ 10% gain fluctuations in the observed brightness of calibrator sources. This result is highly encouraging for the ability of PAPER to remove a potentially dominant systematic in its power spectrum and cataloging measurements without resorting to a complicated system overhaul. The second new algorithm developed in this dissertation solves a major calibration challenge not

  17. Study on energy density of gold-vapor laser and necrosis depth of mouse malignant tumor (S180)

    NASA Astrophysics Data System (ADS)

    Guo, Yong; Wang, Ze-shi; Yang, Yonghua; Wang, Yongjiang

    1993-03-01

    Gold-vapor laser glass type is a new laser for photodynamic therapy (PDT). Its chief characteristics are pulse type, 6000 - 7000 Hz of frequency, 627.8 nm in wavelength, 3 - 4 watts output, etc. By changing laser energy density, we noticed changes of necrosis depth and surface temperature. The results show that the depth of groups of 500, 1000, 1500, and 2000 Jol/cm2 were 0.62 +/- 0.21, 0.72 +/- 0.05, 0.97 +/- 0.10, and 1.56 +/- 0.13 cm (p < 0.05), respectively. This study indicates that the pulse laser energy density should be larger than that of a continuant one in PDT, thus photodynamic effect may be improved in the clinic. The surface tumor temperature was changed during the treatment, reaching as high as 39.13 degree(s)C, 43.78 degree(s)C, 44.16 degree(s)C, and 43.5 degree(s)C in different groups. This paper also discusses the coordinated effects of hyperthermia and photodynamic therapy.

  18. Studies of electrical conductivity and complex initial permeability of multiferroic xBa0.95Sr0.05TiO3-(1-x)BiFe0.90Gd0.10O3 ceramics

    NASA Astrophysics Data System (ADS)

    Miah, Mohammad J.; Khan, M. N. I.; Hossain, A. K. M. Akther

    2016-07-01

    Multiferroic xBa0.95Sr0.05TiO3-(1-x)BiFe0.90Gd0.10O3 [xBST-(1-x)BFGO] (x = 0.00, 0.10 and 0.20) ceramics were prepared by the standard solid-state reaction technique. Crystal structure of the ceramics was determined by X-ray diffraction pattern. All the compositions exhibited rhombohedral crystal structure. The tolerance factor `t' varied from 0.847 to 0.864. The AC conductivity spectrum followed the Jonscher's power law. The Nyquist plots indicated that only grains have the contribution to the resistance in this material and the values of grain resistance (Rg) increased with BST content. The real part of complex initial permeability decreased with the increase in frequency and increased with increasing BST content. Magnetoelectric coefficient was determined for all compositions. The maximum value of magnetoelectric coefficient was found to be 1.467 mV.cm-1.Oe-1 for x = 0.20.

  19. Acute potentiating effect of depth jumps on sprint performance.

    PubMed

    Byrne, Paul J; Kenny, John; O' Rourke, Brian

    2014-03-01

    The purpose of this investigation was to determine whether the addition of 3 depth jumps to a dynamic warm-up (DYNDJ) protocol would significantly improve 20-m sprint performance when compared with a cardiovascular (C) warm-up protocol or a dynamic (DYN) stretching protocol alone. The first part of the study identified optimal drop height for all subjects using the maximum jump height method. The identified optimal drop heights were later used during the DYNDJ protocol. The second part compared the 3 warm-up protocols above to determine their effect on 20-m sprint performance. Twenty-nine subjects (age, 20.8 ± 4.4 years; weight, 82.6 ± 9.9 kg; height, 180.3 ± 6.2 cm) performed 3 protocols of a C protocol, a DYN protocol, and a DYNDJ protocol in a randomized order. A 20-m sprint was performed 1 minute after the completion of each of the 3 protocols. Results displayed significant differences between each of the 3 protocols. A significant improvement (p = 0.001) of 2.2% was obtained in sprint time between the C protocol (3.300 ± 0.105 seconds) and the DYN protocol (3.227 ± 0.116 seconds), a further significant improvement of 5.01% was attained between the C and the DYNDJ protocols (3.300 ± 0.10 vs. 3.132 ± 0.120 seconds; p = 0.001). In addition, a significant improvement (p = 0.001) of 2.93% was observed between the DYN protocol (3.227 ± 0.116 seconds) and the DYNDJ protocol (3.132 ± 0.116 seconds). The data from this study advocate the use of DYNDJ protocol as a means of significantly improving 20-m sprint performance 1 minute after the DYNDJ protocol. PMID:23799423

  20. 70-cm radar observations of 433 Eros

    NASA Technical Reports Server (NTRS)

    Campbell, D. B.; Pettengill, G. H.; Shapiro, I. I.

    1976-01-01

    Radar observations of 433 Eros were made at the Arecibo Observatory using a wavelength of 70 cm during the close approach of Eros to earth in mid-January, 1975. A peak radar cross section of plus or minus 15 sq km was observed. The spectral broadening obtained was approximately 30 Hz, which is consistent with a value of 16 km for the maximum radius of the asteroid. The surface of Eros appears to be relatively rough at the scale of a wavelength as compared to the surfaces of the terrestrial planets and the moon. The composition of the surface is not well determined, except that it cannot be a highly conducting metal. A single measurement each of round-trip echo times delay and Doppler shift was made.

  1. NASA 30 Cm Ion Thruster Development Status

    NASA Technical Reports Server (NTRS)

    Patterson, Michael J.; Haag, Thomas W.; Rawlin, Vincent K.; Kussmaul, Michael T.

    1995-01-01

    A 30 cm diameter xenon ion thruster is under development at NASA to provide an ion propulsion option for missions of national interest and it is an element of the NASA Solar Electric Propulsion Technology Applications Readiness (NSTAR) program established to validate ion propulsion for space flight applications. The thruster has been developed to an engineering model level and it incorporates innovations in design, materials, and fabrication techniques compared to those employed to conventional ion thrusters. The performance of both functional and engineering model thrusters has been assessed including thrust stand measurements, over an input power range of 0.5-2.3 kW. Attributes of the engineering model thruster include an overall mass of 6.4 kg, and an efficiency of 65 percent and thrust of 93 mN at 2.3 kW input power. This paper discusses the design, performance, and lifetime expectations of the functional and engineering model thrusters under development at NASA.

  2. 21 Cm Tomography With the Alfalfa Survey

    NASA Astrophysics Data System (ADS)

    Fry, Alexander B.; Boutan, C.; Carroll, P. A.; Hazelton, B.; Morales, M. F.

    2011-01-01

    Neutral hydrogen (HI) 21cm intensity mapping, or HI tomography is a promising technique being utilized by several upcoming experiments (LOFAR, MWA, SKA). The measurement of volume averaged neutral hydrogen mass density in synoptic sky surveys can be applied to the study of the HI mass function, the distribution of large scale structure, the reionization of the universe, and the expansion history of the universe through such standard rulers as baryonic acoustic oscillations. In order to prepare for future experiments, in particular the Murchison Widefield Array (MWA), we analyze the Arecbo Legacy Fast ALFA (Arecibo L-Band Feed Array) Feed Array (ALFALFA) survey data to probe the spatial density variations of HI in our local universe (z <0.06) where data is currently available. We address challenges unique to data of this kind, such as identifying and subtracting out signal from RFI and local galactic sources, and characterizing the ALFA array beam pattern which dictates sensitivity and resolution.

  3. The 30-cm ion thruster power processor

    NASA Technical Reports Server (NTRS)

    Herron, B. G.; Hopper, D. J.

    1978-01-01

    A power processor unit for powering and controlling the 30 cm Mercury Electron-Bombardment Ion Thruster was designed, fabricated, and tested. The unit uses a unique and highly efficient transistor bridge inverter power stage in its implementation. The system operated from a 200 to 400 V dc input power bus, provides 12 independently controllable and closely regulated dc power outputs, and has an overall power conditioning capacity of 3.5 kW. Protective circuitry was incorporated as an integral part of the design to assure failure-free operation during transient and steady-state load faults. The implemented unit demonstrated an electrical efficiency between 91.5 and 91.9 at its nominal rated load over the 200 to 400 V dc input bus range.

  4. Outreach program by measurements of frost depth in Japan

    NASA Astrophysics Data System (ADS)

    Harada, K.; Yoshikawa, K.; Iwahana, G.; Stanilovskaya, J. V.; Sawada, Y.

    2015-12-01

    In order to emphasis their interest for earth sciences, an outreach program through measurements of frost depth is conducting in Japan since 2011. This program is made at elementary, junior high and high schools in Hokkaido, northern part of Japan where seasonal ground freezing occurs in winter. At schools, a lecture was made and a frost tube was set at schoolyard, as the same tube and protocol as UAF's Permafrost Outreach Program, using clear tube with blue-colored water. Frost depth was measured directly once a week at each school by students during ground freezing under no snow-removal condition. In 2011 season, we started this program at three schools, and the number of participated school is extended to 29 schools in 2014 winter season, 23 elementary schools, 5 junior high schools and one high school. We visited schools summer time and just before frost season to talk about the method of measurement. After the end of measured period, we also visited schools to explain measured results by each school and the other schools in Japan, Alaska, Canada and Russia. The measured values of frost depth in Hokkaido were ranged between 0cm and more than 50cm. We found that the frost depth depends on air temperature and snow depth. We discussed with student why the frost depth ranged widely and explained the effect of snow by using the example of igloo. In order to validate the effect of snow and to compare frost depths, we tried to measure frost depths under snow-removal and no snow-removal conditions at one elementary school. At the end of December, depths had no significant difference between these conditions, 11cm and 10cm, and the difference went to 14cm, 27cm and 13cm after one month, with about 30cm of snow depth. After these measurements and lectures, students noticed snow has a role as insulator and affects the frost depth. The network of this program will be expected to expand, finally more than a hundred schools.

  5. Statistical classification of vegetation and water depths in montane wetlands

    USGS Publications Warehouse

    Sharp, Julia L.; Sodja, Richard S.; Greenwood, Mark; Rosenberry, Donald O.; Warren, Jeffrey M.

    2013-01-01

    Relationships between water depths and density of submergent vegetation were studied in montane wetlands using statistical techniques based on clustering and an extension of regression trees. Sago pondweed (Stuckenia pectinata) was associated with lower average water depths than water milfoil (Myriophyllum sibiricum). We detected a nonlinear relationship when average water depths were used to predict percent cover in S. pectinata, with depths of 30–40 cm, producing the highest predicted average percent cover of S. pectinata; higher and lower depths resulted in lower percent cover predictions. For M. sibiricum, higher water depths were monotonically associated with higher average percent cover. To foster more S. pectinata and less M. sibiricum, managers might employ water control structures to reduce water depths below 1 m, using both temporary drawdowns and average depths of 30–40 cm. Other species responded less markedly to water depth variation. Should decreased water depths become more common, these results suggest an increase in S. pectinata and a decrease in M. sibiricum.

  6. Evaluation of Argonne 9-cm and 10-cm Annular Centrifugal Contactors for SHINE Solution Processing

    SciTech Connect

    Wardle, Kent E.; Pereira, Candido; Vandegrift, George

    2015-02-01

    Work is in progress to evaluate the SHINE Medical Technologies process for producing Mo-99 for medical use from the fission of dissolved low-enriched uranium (LEU). This report addresses the use of Argonne annular centrifugal contactors for periodic treatment of the process solution. In a letter report from FY 2013, Pereira and Vandegrift compared the throughput and physical footprint for the two contactor options available from CINC Industries: the V-02 and V-05, which have rotor diameters of 5 cm and 12.7 cm, respectively. They suggested that an intermediately sized “Goldilocks” contactor might provide a better balance between throughput and footprint to meet the processing needs for the uranium extraction (UREX) processing of the SHINE solution to remove undesired fission products. Included with the submission of this letter report are the assembly drawings for two Argonne-design contactors that are in this intermediate range—9-cm and 10-cm rotors, respectively. The 9-cm contactor (drawing number CE-D6973A, stamped February 15, 1978) was designed as a single-stage unit and built and tested in the late 1970s along with other size units, both smaller and larger. In subsequent years, a significant effort to developed annular centrifugal contactors was undertaken to support work at Hanford implementing the transuranic extraction (TRUEX) process. These contactors had a 10-cm rotor diameter and were fully designed as multistage units with four stages per assembly (drawing number CMT-E1104, stamped March 14, 1990). From a technology readiness perspective, these 10-cm units are much farther ahead in the design progression and, therefore, would require significantly less re-working to make them ready for UREX deployment. Additionally, the overall maximum throughput of ~12 L/min is similar to that of the 9-cm unit (10 L/min), and the former could be efficiently operated over much of the same range of throughput. As a result, only the 10-cm units are considered here

  7. Cycling Stability Performance of La0.75Mg0.25Ni3.5Si0.10 Hydrogen Storage Alloy in Discharge-Charge System

    NASA Astrophysics Data System (ADS)

    Liu, Zhaojiang; Huang, Lei; Wan, Qi; Li, Xu; Guang, Ma; Li, Ping

    2014-12-01

    La0.75Mg0.25Ni3.5Si0.10 hydrogen storage alloy was prepared by vacuum induction melting furnace and subsequently heated treatment at 940°C for 8 h and cooled to room temperature in the oven. The electrochemical properties of La0.75Mg0.25Ni3.5Si0.10 compound were measured by LAND CT2001A battery test system. The morphologies of the samples were characterized by scanning electron microscopy (SEM). The surface state of samples was analyzed by X-ray photoelectron spectroscopy (XPS). It was found that the charge-discharge rate plays the key impact on the cycling stability of the alloy. During the cycle test, the prepared La0.75Mg0.25Ni3.5Si0.10 compound presented an excellent capacity retention at the charge-discharge of 1 C while the capacity of sample declined rapidly at 0.2 C. The excellent cycling stability performance of La0.75Mg0.25Ni3.5Si0.10 electrode at 1 C could be attributed to the less powder and less oxidation of surface effective active elements. The pulverization inevitably leads to the separation of the part of the cracking alloy and the electrode, resulting in reduction of the effective active substance and increasing attenuation of the capacity per cycle. In addition, on the analysis of the different cut-off potential effects on the electrode, it was found that the La0.75Mg0.25Ni3.5Si0.10 electrode shows good comprehensive electrochemical properties at 1 C cut-off 0.6-0.7 V. During charging, heavy overcharge will not be conducive to cycling stability performance during the charging test.

  8. ICD-9-CM to ICD-10-CM Codes: What? Why? How?

    PubMed Central

    Cartwright, Donna J.

    2013-01-01

    The wound care industry will gain many benefits when International Classification of Diseases (ICD)-10-Clinical Modification (CM) is implemented. One of the main benefits is that the disease classifications will be consistent with current clinical practice and medical technology advances. The new classification codes will be very granular, which means the level of specificity will greatly improve. Numerous new codes will represent more specific anatomic sites, etiologies, comorbidities, and complications, and will improve the ability to demonstrate severity of illness. For instance, the new feature of laterality is directly built into the new codes: separate codes will distinguish right, left, and bilateral, where needed. The increased granularity will provide better analysis of disease patterns and outbreak of disease. Additionally, the United States will finally be using the same diagnosis coding system as the rest of the world. This article will describe what the ICD-9-CM/ICD-10-CM codes are, why they are so important, and how clinicians and researchers will convert from ICD-9-CM to ICD-10-CM effective October 1, 2014. PMID:24761333

  9. The 15 cm diameter ion thruster research

    NASA Technical Reports Server (NTRS)

    Wilbur, P. J.

    1974-01-01

    The startup reliability of a 15 cm diameter mercury bombardment ion thruster which employs a pulsed high voltage tickler electrode on the main and neutralizer cathodes is examined. Startup of the thruster is achieved 100% of the time on the main cathode and 98.7% of the time on the neutralizer cathode over a 3640 cycle test. The thruster was started from a 20 C initial condition and operated for an hour at a 600 mA beam current. An energy efficiency of 75% and a propellant utilization efficiency of 77% was achieved over the complete cycle. The effect of a single cusp magnetic field thruster length on its performance is discussed. Guidelines are formulated for the shaping of magnetic field lines in thrusters. A model describing double ion production in mercury discharges is presented. The production route is shown to occur through the single ionic ground state. Photographs of the interior of an operating-hollow cathode are presented. A cathode spot is shown to be present if the cathode is free of low work-function surfaces. The spot is observed if a low work-function oxide coating is applied to the cathode insert. Results show that low work-function oxide coatings tend to migrate during thruster operation.

  10. Engineering model 8-cm thruster subsystem

    NASA Technical Reports Server (NTRS)

    Herron, B. G.; Hyman, J.; Hopper, D. J.; Williamson, W. S.; Dulgeroff, C. R.; Collett, C. R.

    1978-01-01

    An Engineering Model (EM) 8 cm Ion Thruster Propulsion Subsystem was developed for operation at a thrust level 5 mN (1.1 mlb) at a specific impulse 1 sub sp = 2667 sec with a total system input power P sub in = 165 W. The system dry mass is 15 kg with a mercury-propellant-reservoir capacity of 8.75 kg permitting uninterrupted operation for about 12,500 hr. The subsystem can be started from a dormant condition in a time less than or equal to 15 min. The thruster has a design lifetime of 20,000 hr with 10,000 startup cycles. A gimbal unit is included to provide a thrust vector deflection capability of + or - 10 degrees in any direction from the zero position. The EM subsystem development program included thruster optimization, power-supply circuit optimization and flight packaging, subsystem integration, and subsystem acceptance testing including a cyclic test of the total propulsion package.

  11. The effect of drought and interspecific interactions on the depth of water uptake in deep- and shallow-rooting grassland species as determined by δ18O natural abundance

    NASA Astrophysics Data System (ADS)

    Hoekstra, N. J.; Finn, J. A.; Lüscher, A.

    2014-03-01

    Increased incidence of weather drought, as predicted under climate change, has the potential to negatively affect grassland production. Compared to monocultures, vertical belowground niche complementarity between shallow- and deep-rooting species may be an important mechanism resulting in higher yields and higher resistance to drought in grassland mixtures. However, very little is known about the belowground responses in grassland systems and increased insight into these processes may yield important information both to predict the effect of future climate change and better design agricultural systems to cope with this. This study assessed the effect of a 10-week experimental summer drought on the depth of water uptake of two shallow-rooting species (Lolium perenne L. and Trifolium repens L.) and two deep-rooting species (Chicorium intybus L. and Trifolium pratense L.) in grassland monocultures and four-species-mixtures by using the natural abundance δ18O isotope method. We tested the following hypotheses: (1) drought results in a shift of water uptake to deeper soil layers, (2) deep-rooting species take up a higher proportion of water from deeper soil layers relative to shallow-rooting species, (3) as a result of interspecific interactions in mixtures, the water uptake of shallow-rooting species become shallower when grown together with deep-rooting species and vice versa, resulting in reduced niche overlap. The natural abundance δ18O technique provided novel insights into the depth of water uptake of deep- and shallow- rooting grassland species and revealed large shifts in response to drought and interspecific interactions. Compared to control conditions, drought reduced the proportional water uptake from 0-10 cm soil depth (PCWU0-10) of L. perenne, T. repens and C. intybus in monocultures by on average 54%. In contrast, the PCWU0-10 of T. pratense in monoculture increased by 44%, and only when grown in mixture did the PCWU0-10 of T. pratense decrease under

  12. Efficient multiview depth video coding using depth synthesis prediction

    NASA Astrophysics Data System (ADS)

    Lee, Cheon; Choi, Byeongho; Ho, Yo-Sung

    2011-07-01

    The view synthesis prediction (VSP) method utilizes interview correlations between views by generating an additional reference frame in the multiview video coding. This paper describes a multiview depth video coding scheme that incorporates depth view synthesis and additional prediction modes. In the proposed scheme, we exploit the reconstructed neighboring depth frame to generate an additional reference depth image for the current viewpoint to be coded using the depth image-based-rendering technique. In order to generate high-quality reference depth images, we used pre-processing on depth, depth image warping, and two types of hole filling methods depending on the number of available reference views. After synthesizing the additional depth image, we encode the depth video using the proposed additional prediction modes named VSP modes; those additional modes refer to the synthesized depth image. In particular, the VSP_SKIP mode refers to the co-located block of the synthesized frame without the coding motion vectors and residual data, which gives most of the coding gains. Experimental results demonstrate that the proposed depth view synthesis method provides high-quality depth images for the current view and the proposed VSP modes provide high coding gains, especially on the anchor frames.

  13. A sub-cm micromachined electron microscope

    NASA Technical Reports Server (NTRS)

    Feinerman, A. D.; Crewe, D. A.; Perng, D. C.; Shoaf, S. E.; Crewe, A. V.

    1993-01-01

    A new approach for fabricating macroscopic (approximately 10x10x10 mm(exp 3)) structures with micron accuracy has been developed. This approach combines the precision of semiconductor processing and fiber optic technologies. A (100) silicon wafer is anisotropically etched to create four orthogonal v-grooves and an aperture on each 10x12 mm die. Precision 308 micron optical fibers are sandwiched between the die to align the v-grooves. The fiber is then anodically bonded to the die above and below it. This procedure is repeated to create thick structures and a stack of 5 or 6 die will be used to create a miniature scanning electron microscope (MSEM). Two die in the structure will have a segmented electrode to deflect the beam and correct for astigmatism. The entire structure is UHV compatible. The performance of an SEM improves as its length is reduced and a sub-cm 2 keV MSEM with a field emission source should have approximately 1 nm resolution. A low voltage high resolution MSEM would be useful for the examination of biological specimens and semiconductors with a minimum of damage. The first MSEM will be tested with existing 6 micron thermionic sources. In the future a micromachined field emission source will be used. The stacking technology presented in this paper can produce an array of MSEMs 1 to 30 mm in length with a 1 mm or larger period. A key question being addressed by this research is the optimum size for a low voltage MSEM which will be determined by the required spatial resolution, field of view, and working distance.

  14. Pressure distributions obtained on a 0.10-scale model of the space shuttle Orbiter's forebody in the AEDC 16T propulsion wind tunnel

    NASA Technical Reports Server (NTRS)

    Siemers, P. M., III; Henry, M. W.

    1986-01-01

    Pressure distribution test data obtained on a 0.10-scale model of the forward fuselage of the Space Shuttle Orbiter are presented without analysis. The tests were completed in the AEDC 16T Propulsion Wind Tunnel. The 0.10-scale model was tested at angles of attack from -2 deg to 18 deg and angles of side slip from -6 to 6 deg at Mach numbers from 0.25 to 1/5 deg. The tests were conducted in support of the development of the Shuttle Entry Air Data System (SEADS). In addition to modeling the 20 SEADS orifices, the wind-tunnel model was also instrumented with orifices to match Development Flight Instrumentation (DFI) port locations that existed on the Space Shuttle Orbiter Columbia (OV-102) during the Orbiter Flight Test program. This DFI simulation has provided a means of comparisons between reentry flight pressure data and wind-tunnel and computational data.

  15. Going the distance: validation of Acuros and AAA at an extended SSD of 400 cm.

    PubMed

    Lamichhane, Narottam; Patel, Vivek N; Studenski, Matthew T

    2016-01-01

    Accurate dose calculation and treatment delivery is essential for total body irradiation (TBI). In an effort to verify the accuracy of TBI dose calculation at our institution, we evaluated both the Varian Eclipse AAA and Acuros algorithms to predict dose distributions at an extended source-to-surface distance (SSD) of 400 cm. Measurements were compared to calculated values for a 6 MV beam in physical and virtual phantoms at 400 cm SSD using open beams for both 5 × 5 and 40 × 40cm2 field sizes. Inline and crossline profiles were acquired at equivalent depths of 5 cm, 10 cm, and 20 cm. Depth-dose curves were acquired using EBT2 film and an ion chamber for both field sizes. Finally, a RANDO phantom was used to simulate an actual TBI treatment. At this extended SSD, care must be taken using the planning system as there is good relative agreement between measured and calculated profiles for both algorithms, but there are deviations in terms of the absolute dose. Acuros has better agreement than AAA in the penumbra region. PMID:27074473

  16. Neutron powder diffraction study and magnetic properties in LaMn1-xCuxO3 (x=0.05, 0.10 and 0.15)

    NASA Astrophysics Data System (ADS)

    Samantaray, B.; Srivastava, S. K.; Mohanty, S.; Ravi, S.; Dhiman, I.; Das, A.

    2010-05-01

    LaMn1-xCuxO3 (x=0.05 to 0.15) samples were prepared and their crystal structure and magnetic properties were studied by recording neutron powder diffraction patterns and M-H loops at different temperatures. Even though the samples were free from impurity, the x=0.05 and 0.10 samples are found to crystallize in mixture of R3¯c and Pnma space group with dominate fraction of former one. The phase fraction for x=0.10 sample is found to vary with temperature especially below the ferromagnetic TC. The x=0.15 sample could be refined based on Pnma space group. The patterns at low temperatures could be refined by considering magnetic reflections corresponding to ferromagnetic structure. The magnetic moments of Mn ion are found to be along b axis with typical value of 3.40(3)μB for x=0.10 sample. From the analysis of the diffraction patterns and the magnetization data, it is found that x=0.15 sample exhibit spin canting.

  17. Natural fracturing, by depth

    NASA Astrophysics Data System (ADS)

    Hooker, John; Laubach, Stephen

    2013-04-01

    Natural opening-mode fractures commonly fall upon a spectrum whose end-members are veins, which have wide ranges of sizes and are mostly or thoroughly cemented, and joints, which have little opening displacement and little or no cement. The vein end-member is common in metamorphic rocks, whose high temperature and pressure of formation place them outside typical reservoir settings; conversely, many uncemented joints likely form near the surface and so too have limited relevance to subsurface exploration. Sampling of cores retrieved from tight-gas sandstone reservoirs suggest that it is intermediate fractures, not true joints or veins, that provide natural porosity and permeability. Such fractures have abundant pore space among fracture-bridging cements, which may hold fractures open despite varying states of stress through time. Thus the more sophisticated our understanding of the processes that form veins and joints, i.e., how natural fracturing varies by depth, the better our ability to predict intermediate fractures. Systematic differences between veins and joints, in terms of size-scaling and lateral and stratigraphic spatial arrangement, have been explained in the literature by the mechanical effects of sedimentary layering, which likely exert more control over fracture patterns at shallower depths. Thus stratabound joints commonly have narrow size ranges and regular spacing; non-stratabound veins have a wide range of sizes and spacings. However, new fieldwork and careful literature review suggest that the effects of mechanical layering are only half the story. Although atypical, veins may be highly stratabound and yet spatially clustered; non-stratabound fractures may nonetheless feature narrow size ranges. These anomalous fracture arrangements are better explained by the presence of precipitating cements during fracture opening than by mechanical layering. Cement is thought to be highly important for fracture permeability, but potential effects of

  18. No shift to a deeper water uptake depth in response to summer drought of two lowland and sub-alpine C₃-grasslands in Switzerland.

    PubMed

    Prechsl, Ulrich E; Burri, Susanne; Gilgen, Anna K; Kahmen, Ansgar; Buchmann, Nina

    2015-01-01

    Temperate C3-grasslands are of high agricultural and ecological importance in Central Europe. Plant growth and consequently grassland yields depend strongly on water supply during the growing season, which is projected to change in the future. We therefore investigated the effect of summer drought on the water uptake of an intensively managed lowland and an extensively managed sub-alpine grassland in Switzerland. Summer drought was simulated by using transparent shelters. Standing above- and belowground biomass was sampled during three growing seasons. Soil and plant xylem waters were analyzed for oxygen (and hydrogen) stable isotope ratios, and the depths of plant water uptake were estimated by two different approaches: (1) linear interpolation method and (2) Bayesian calibrated mixing model. Relative to the control, aboveground biomass was reduced under drought conditions. In contrast to our expectations, lowland grassland plants subjected to summer drought were more likely (43-68%) to rely on water in the topsoil (0-10 cm), whereas control plants relied less on the topsoil (4-37%) and shifted to deeper soil layers (20-35 cm) during the drought period (29-48%). Sub-alpine grassland plants did not differ significantly in uptake depth between drought and control plots during the drought period. Both approaches yielded similar results and showed that the drought treatment in the two grasslands did not induce a shift to deeper uptake depths, but rather continued or shifted water uptake to even more shallower soil depths. These findings illustrate the importance of shallow soil depths for plant performance under drought conditions.

  19. PROCESS OF PRODUCING Cm$sup 244$ AND Cm$sup 24$$sup 5$

    DOEpatents

    Manning, W.M.; Studier, M.H.; Diamond, H.; Fields, P.R.

    1958-11-01

    A process is presented for producing Cm and Cm/sup 245/. The first step of the process consists in subjecting Pu/sup 2339/ to a high neutron flux and subsequently dissolving the irradiated material in HCl. The plutonium is then oxidized to at least the tetravalent state and the solution is contacted with an anion exchange resin, causing the plutonium values to be absorbed while the fission products and transplutonium elements remain in the effluent solution. The effluent solution is then contacted with a cation exchange resin causing the transplutonium, values to be absorbed while the fission products remain in solution. The cation exchange resin is then contacted with an aqueous citrate solution and tbe transplutonium elements are thereby differentially eluted in order of decreasing atomic weight, allowing collection of the desired fractions.

  20. Effect of local crosstalk on depth perception

    NASA Astrophysics Data System (ADS)

    Watanabe, Hiroshi; Ujike, Hiroyasu; Penczek, John; Boynton, Paul A.

    2014-03-01

    Interocular crosstalk has a significant undesirable effect on the quality of 3D displays that utilize horizontal disparity. This study investigates observer sensitivity when judging the depth order of two horizontally aligned dots on a 3D display and assesses 3D display uniformity by obtaining this index for various locations on the display. Visual stimulus is two horizontally disparate dots, with nine steps of horizontal disparity. A dot pair is presented at five screen locations. An observer wearing polarized glasses sits 57 cm from a display, observes it through a slit, and judges the depth order of two dots. Each of the 20 observers responds 16 times per disparate dot pair, and we calculate the rate at which observers judge the dot on the right to be nearer in 16 trials for each display, screen location, and disparity. We then plot the rate as a function of the left-right dot disparity and fit a psychometric function to the plot. A curve slope at a response probability of 50% is used to gauge the sensitivity of depth order judgment. Results show the depth sensitivity variation across the display surface depends on interocular-crosstalk variation across the display thus its uniformity of the display.

  1. Airborne Surveys of Snow Depth over Arctic Sea Ice

    NASA Technical Reports Server (NTRS)

    Kwok, R.; Panzer, B.; Leuschen, C.; Pang, S.; Markus, T.; Holt, B.; Gogineni, S.

    2011-01-01

    During the spring of 2009, an ultrawideband microwave radar was deployed as part of Operation IceBridge to provide the first cross-basin surveys of snow thickness over Arctic sea ice. In this paper, we analyze data from three approx 2000 km transects to examine detection issues, the limitations of the current instrument, and the regional variability of the retrieved snow depth. Snow depth is the vertical distance between the air \\snow and snow-ice interfaces detected in the radar echograms. Under ideal conditions, the per echogram uncertainty in snow depth retrieval is approx 4 - 5 cm. The finite range resolution of the radar (approx 5 cm) and the relative amplitude of backscatter from the two interfaces limit the direct retrieval of snow depths much below approx 8 cm. Well-defined interfaces are observed over only relatively smooth surfaces within the radar footprint of approx 6.5 m. Sampling is thus restricted to undeformed, level ice. In early April, mean snow depths are 28.5 +/- 16.6 cm and 41.0 +/- 22.2 cm over first-year and multiyear sea ice (MYI), respectively. Regionally, snow thickness is thinner and quite uniform over the large expanse of seasonal ice in the Beaufort Sea, and gets progressively thicker toward the MYI cover north of Ellesmere Island, Greenland, and the Fram Strait. Snow depth over MYI is comparable to that reported in the climatology by Warren et al. Ongoing improvements to the radar system and the utility of these snow depth measurements are discussed.

  2. Effects of Zn Substitution on Dielectric and Piezoelectric Properties of (Na0.54K0.46)0.96Li0.04(Nb0.90Ta0.10)O3 Ceramics

    NASA Astrophysics Data System (ADS)

    Byeon, Sunmin; Yoo, Juhyun

    2012-09-01

    In this study, in order to develop lead-free composition ceramics for piezoelectric actuator and sensor applications, (Na0.54K0.46)0.96Li0.04(Nb0.90Ta0.10)1-2x/5ZnxO3 (x = 0-1.5 mol %) composition ceramics were fabricated by a conventional sintering technique at 1110 °C for 5 h. The piezoelectric properties of resultant ceramics were studied with a special emphasis on the influence of Zn-substitution amount. The crystal structure of the specimen exhibited a pure perovskite phase with the coexistence of two phases (orthorhombic and tetragonal phases). However, the phases included tetragonal-rich phases to some extent. The scanning electron microscopy (SEM) images indicated that grain size increased with increasing the content of Zn substitution. High physical properties, namely, piezoelectric constant d33 = 265 pC/N, electromechanical coupling factor kp = 47.5%, dielectric constant ɛr = 1223, and measured density ρ= 4.84 g/cm3 were obtained from the composition ceramic with x = 0.5 mol %. The mechanical quality factor (Qm) was improved from 54 of pure (Na0.54K0.46)0.96Li0.04(Nb0.90Ta0.10)O3 (abbreviated as NKLNT) to 106 by 1.5 mol % Zn substitution. The results reflect that the material is a promising candidate for lead-free high-performance piezoelectric device applications, such as piezoelectric actuators and sensors.

  3. Ozone concentration and pulmonary response relationships for 6. 6-hour exposures with five hours of moderate exercise to 0. 08, 0. 10, and 0. 12 ppm

    SciTech Connect

    Horstman, D.H.; Folinsbee, L.J.; Ives, P.J.; Abdul-Salaam, S.; McDonnell, W.F. )

    1990-11-01

    The magnitudes of pulmonary responses we previously observed (1) following 6.6-h exposures to 0.12 ppm ozone (O3) suggested that responses would also occur with similar exposures at lower O3 concentrations. The objective of this study was to determine the extent of pulmonary function decrements, respiratory discomfort, and increased airway reactivity to methacholine induced by exposure to O3 below 0.12 ppm. Separate 6.6-h chamber exposures to 0.00, 0.08, 0.10, and 0.12 ppm O3 included six 50-min periods of moderate exercise (VE approximately equal to 39 L/min, HR approximately equal to 115 bpm, and VO2 approximately equal to 1.5 L/min). Each exercise period was followed by 10 min of rest. A 35-min lunch break was included midway through the exposure. Although not intended as an exact simulation, the overall duration, intensity, and metabolic requirements of the exercise performed were representative of a day of moderate to heavy work or play. Preexposure FEV1 averaged 4.39 L, and essentially no change (+0.03 L) occurred with exposure to 0.00 ppm O3. Significant decreases (p less than 0.01) of -0.31, -0.30, and -0.54 L were observed with exposures to 0.08, 0.10, and 0.12 ppm, respectively. The provocative dose of methacholine required to increase airway resistance by 100% (PD100) was 58 cumulative inhalation units (CIU) following exposure to 0.00 ppm and was significantly reduced (p less than 0.01) to 37 CIU at 0.08, 31 CIU at 0.10, and 26 CIU at 0.12 ppm O3; reductions in PD100 are considered indicative of increases in nonspecific airway responsiveness.

  4. Sub-cm Particles in Saturn's Rings from VIMS, UVIS, and RSS occultations

    NASA Astrophysics Data System (ADS)

    Jerousek, Richard Gregory; Colwell, Josh E.; Hedman, Matthew M.; Marouf, Essam A.; Esposito, Larry W.; Nicholson, Philip D.; French, Richard G.

    2016-10-01

    Particles sizes in Saturn's rings roughly follow a truncated power law. One way to determine the governing parameters of the size distribution is through the analysis of differential optical depths (Zebker et al. 1983). Non-axisymmetric self-gravity wakes complicate this approach when optical depth measurements at different wavelengths are not made at same viewing geometry. Using occultations spanning a wide range of viewing angles and from multiple instruments onboard Cassini (the Ultraviolet Imaging Spectrograph (UVIS), the Visual and Infrared Mapping Spectrometer (VIMS), and the Radio Science Subsystem (RSS)), we forward-model the properties of the self-gravity wakes in Saturn's A and B rings while simultaneously constraining the parameters of the cm – sub-cm particle size distribution. In the absence of wakes, and in regions where particles smaller than ~ 8.86 mm are present, VIMS stellar occultations measure larger optical depths than UVIS stellar occultations due to the diffraction of 2.9 μm light out of the small (0.25 × 0.5 mrad) VIMS field of view compared with UVIS which measures shorter wavelength (0.15 μm) light over a much larger (6.4 × 6.0 mrad) field of view. This excess optical depth combined with RSS X-band (λ = 3.6 cm) optical depths provides a way to probe both the power law slope and the minimum particle size. In the A and B rings where self-gravity wakes are prevalent, we use the wake model of Colwell et al. (2006, 2007) with an additional free parameter representing the excess optical depth which would be measured through the gaps between opaque wakes, by VIMS compared to UVIS. In the B ring and inner A ring we find and absence of sub-cm particles and power law slopes of q ~ 2.8. In the trans-Encke region, where there are a multitude of satellite driven resonances, we find an increasing abundance of sub-cm particles as the outer edge of the A ring is approached. In the C Ring and the Cassini Division, where self-gravity wakes are absent

  5. A depth dependence determination of the wedge transmission factor for 4-10 MV photon beams.

    PubMed

    McCullough, E C; Gortney, J; Blackwell, C R

    1988-01-01

    The depth dependence (up to 25 cm) of the in-phantom wedge transmission factor (WTF) has been determined for three medical linear accelerator x-ray beams with energies of 4, 6, and 10 MV containing 15 degrees-60 degrees (nominal) brass wedges. All measurements were made with a cylindrical ionization chamber in water, for a field size of 10 X 10 cm2 with a source-skin distance of 80 or 100 cm. We conclude that, for the accelerators studied, the WTF factor at depth is less than 2% different from that determined at dmax (for the nominal wedge angles and photon energies studied) unless the depth of interest is greater than 10 cm. Up to the maximum depth studied (25 cm) the relative wedge factor--that is, wedge factor at depth compared to that determined at dmax--was about equal to or less than 1.02 for the 15 degrees and 30 degrees wedges and any of the photon beam energies studied. For the seldom utilized combination of a nominal wedge angle in excess of 45 degrees with a depth greater than 10 cm, the WTF at depth can differ from the WTF determined at dmax, by up to 5%. Since the wedge transmission factor is reflective of relative percent dose data, our results also indicate that it is in error to use open field percent depth doses for certain combinations of wedge angle, photon energy, and depth. PMID:3211057

  6. MAPPING THE DYNAMICS OF COLD GAS AROUND SGR A* THROUGH 21 cm ABSORPTION

    SciTech Connect

    Christian, Pierre; Loeb, Abraham

    2015-11-20

    The presence of a circumnuclear stellar disk around Sgr A* and megamaser systems near other black holes indicates that dense neutral disks can be found in galactic nuclei. We show that depending on their inclination angle, optical depth, and spin temperature, these disks could be observed spectroscopically through 21 cm absorption. Related spectroscopic observations of Sgr A* can determine its HI disk parameters and the possible presence of gaps in the disk. Clumps of dense gas similar to the G2 could could also be detected in 21 cm absorption against Sgr A* radio emission.

  7. Jupiter Clouds in Depth

    NASA Technical Reports Server (NTRS)

    2000-01-01

    [figure removed for brevity, see original site] 619 nm [figure removed for brevity, see original site] 727 nm [figure removed for brevity, see original site] 890 nm

    Images from NASA's Cassini spacecraft using three different filters reveal cloud structures and movements at different depths in the atmosphere around Jupiter's south pole.

    Cassini's cameras come equipped with filters that sample three wavelengths where methane gas absorbs light. These are in the red at 619 nanometer (nm) wavelength and in the near-infrared at 727 nm and 890 nm. Absorption in the 619 nm filter is weak. It is stronger in the 727 nm band and very strong in the 890 nm band where 90 percent of the light is absorbed by methane gas. Light in the weakest band can penetrate the deepest into Jupiter's atmosphere. It is sensitive to the amount of cloud and haze down to the pressure of the water cloud, which lies at a depth where pressure is about 6 times the atmospheric pressure at sea level on the Earth). Light in the strongest methane band is absorbed at high altitude and is sensitive only to the ammonia cloud level and higher (pressures less than about one-half of Earth's atmospheric pressure) and the middle methane band is sensitive to the ammonia and ammonium hydrosulfide cloud layers as deep as two times Earth's atmospheric pressure.

    The images shown here demonstrate the power of these filters in studies of cloud stratigraphy. The images cover latitudes from about 15 degrees north at the top down to the southern polar region at the bottom. The left and middle images are ratios, the image in the methane filter divided by the image at a nearby wavelength outside the methane band. Using ratios emphasizes where contrast is due to methane absorption and not to other factors, such as the absorptive properties of the cloud particles, which influence contrast at all wavelengths.

    The most prominent feature seen in all three filters is the polar stratospheric haze that makes Jupiter

  8. Depth Matters: Soil pH and dilution effects in the northern Great Plains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the northern Great Plans (NGP), surface sampling depths of 0-15.2 cm or 0-20.3 cm are suggested for testing soil characteristics such as pH. However, acidification is often most pronounced near-surface (e.g., <10 cm). Thus, sampling deeper can potentially dilute (increase) pH measurements and the...

  9. Organic matter evolution throughout a 100-cm ombrotrophic profile from an Italian floating mire

    NASA Astrophysics Data System (ADS)

    Zaccone, Claudio; D'Orazio, Valeria; Lobianco, Daniela; Miano, Teodoro M.

    2015-04-01

    The curious sight of an island floating and moving on a lake naturally, already described by Pliny the Elder in his Naturalis historia (AD 77-79), fascinated people from time immemorial. Floating mires are defined by the occurrence of emergent vegetation rooted in highly organic buoyant mats that rise and fall with changes in water level. Peat-forming floating mires could provide an exceptional tool for environmental studies, since much of their evolution, as well as the changes of the surrounding areas, is recorded in their peat deposits. A complete, 4-m deep peat core was collected in July 2012 from the floating island of Posta Fibreno, a relic mire in the Central Italy. This floating island has a diameter of ca. 30 m, a submerged thickness of about 3 m, and the vegetation is organized in concentric belts, from the Carex paniculata palisade to the Sphagnum centre. Here, some of the southernmost Italian populations of Sphagnum palustre occur. The 14C age dating of macrofossils removed from the sample at 360 cm of depth revealed that the island probably formed more than 500 yrs ago (435±20 yr BP). In the present work, we show preliminary results regarding the evolution of the organic matter along the first, ombrotrophic 100 cm of depth, hoping also to provide some insight into the possible mechanism of the evolution of this floating island. The 100 cm monolith was collected using a Wardenaar corer and cut frozen in 1-cm layers. It consists almost exclusively of Sphagnum mosses, often spaced out, in the top 20-30 cm, by leaves of Populus tremula that annually fell off. This section shows a very low bulk density, ranging from 0.017 and 0.059 g cm-3 (avg. value, 0.03±0.01 g cm-3), an average water content of 96.1±1.1%, and a gravimetric water content ranging between 14.3 and 41.5 gwater gdrypeat-1. The pH of porewaters was in the range 5-5.5. The C content along the profile ranged between 35 and 47% (avg., 41±1%), whereas the N between 0.3 and 0.9% (avg., 0.6±0

  10. Investigations on the germination depth of Johnson grass (Sorghum halepense [L.] pers).

    PubMed

    Tóth, V; Lehoczky, E

    2006-01-01

    The aim of our experiment was to gain data about the germination depth of Johnson grass, and to investigate the dynamics of germination at different sowing depths. These investigations have great importance in respect of effective weed control. The experiments were carried out in the summer of 2005, using pots, in glasshouses. 50 Sorghum halepense chaffy seeds per pot were sown at 1, 5, 10, 15, 20, 25 cm depth. Treatments were used in 4 repeats. Peat:sand mixture in 3:1 ratio was used in the experiments. From the first germination, weeds were counted in every second day for 3 weeks. Finally, we measured the length of sprouts, the fresh root and sprout weight of the weeds, and--after drying--the dry-matter weight as well. The results of the first experiment (carried out in July 2005) showed that 25% of the seeds came up from 15 cm. Most of the weeds (64%) came up from 1 cm depth. Answering to our expectations, the ratio of germination from 5 cm depth was also high: it was 56%. The ratio of germination from 10 cm depth was also good (58%). Another experiment was carried out in August 2005, where the germination of Sorghum halepense was investigated from 20 and 25 cm depth. The results show that in spite of the small size of its seeds (5-7 mm), Johnson grass is able to germinate from 20, 25 cm depth. 30% of the sown seeds germinated from 20 cm depth, and because of the slowing-down of the growth only 6% of them germinated from 25 cm depth.

  11. Irrigation depth far exceeds water uptake depth in an oasis cropland in the middle reaches of Heihe River Basin

    PubMed Central

    Yang, Bin; Wen, Xuefa; Sun, Xiaomin

    2015-01-01

    Agricultural irrigation in the middle reaches of the Heihe River Basin consumes approximately 80% of the total river water. Whether the irrigation depth matches the water uptake depth of crops is one of the most important factors affecting the efficiency of irrigation water use. Our results indicated that the influence of plastic film on soil water δ18O was restricted to 0–30 cm soil depth. Based on a Bayesian model (MixSIR), we found that irrigated maize acquired water preferentially from 0–10 cm soil layer, with a median uptake proportion of 87 ± 15%. Additionally, maize utilised a mixture of irrigation and shallow soil water instead of absorbing the irrigation water directly. However, only 24.7 ± 5.5% of irrigation water remained in 0–10 cm soil layer, whereas 29.5 ± 2.8% and 38.4 ± 3.3% of the irrigation water infiltrated into 10–40 cm and 40–80 cm layers. During the 4 irrigation events, approximately 39% of the irrigation and rainwater infiltrated into soil layers below 80 cm. Reducing irrigation amount and developing water-saving irrigation methods will be important strategies for improving the efficiency of irrigation water use in this area. PMID:26463010

  12. Soil bacterial and fungal community responses to nitrogen addition across soil depth and microhabitat in an arid shrubland.

    PubMed

    Mueller, Rebecca C; Belnap, Jayne; Kuske, Cheryl R

    2015-01-01

    Arid shrublands are stressful environments, typified by alkaline soils low in organic matter, with biologically-limiting extremes in water availability, temperature, and UV radiation. The widely-spaced plants and interspace biological soil crusts in these regions provide soil nutrients in a localized fashion, creating a mosaic pattern of plant- or crust-associated microhabitats with distinct nutrient composition. With sporadic and limited rainfall, nutrients are primarily retained in the shallow surface soil, patterning biological activity. We examined soil bacterial and fungal community responses to simulated nitrogen (N) deposition in an arid Larrea tridentata-Ambrosia dumosa field experiment in southern Nevada, USA, using high-throughput sequencing of ribosomal RNA genes. To examine potential interactions among the N application, microhabitat and soil depth, we sampled soils associated with shrub canopies and interspace biological crusts at two soil depths (0-0.5 or 0-10 cm) across the N-amendment gradient (0, 7, and 15 kg ha(-1) yr(-1)). We hypothesized that localized compositional differences in soil microbiota would constrain the impacts of N addition to a microhabitat distribution that would reflect highly localized geochemical conditions and microbial community composition. The richness and community composition of both bacterial and fungal communities differed significantly by microhabitat and with soil depth in each microhabitat. Only bacterial communities exhibited significant responses to the N addition. Community composition correlated with microhabitat and depth differences in soil geochemical features. Given the distinct roles of soil bacteria and fungi in major nutrient cycles, the resilience of fungi and sensitivity of bacteria to N amendments suggests that increased N input predicted for many arid ecosystems could shift nutrient cycling toward pathways driven primarily by fungal communities. PMID:26388845

  13. Investigation of dielectric and electrical behaviour of nanocrystalline Zn1-xMnxO (x=0 to 0.10) semiconductors synthesized by mechanical alloying

    NASA Astrophysics Data System (ADS)

    Choudhury, S.; Sain, S.; Mandal, M. K.; Pradhan, S. K.; Meikap, A. K.

    2016-07-01

    The results on the measurement of electric and dielectric behaviour and capacitance-voltage characteristics of Zn1-xMnxO (x=0 to 0.10) nanocrystalline semiconductors are reported. Direct current conductivity increases with the increase Mn concentration and its thermal behavior can be explained by adiabatic polaronic hopping model. The alternating current conductivity obeys a power law of temperature and frequency. The temperature exponent p strongly depends on Mn concentration. The temperature dependence of frequency exponent s suggests that the overlapping large polaron conduction model is the appropriate conduction mechanism for the investigated samples. The interfacial boundaries and grain contribution to the dielectric properties can be identified by the analysis of complex impedance. Relaxation behaviour of the samples can be explained from the analysis of the electric modulus. Formation of Schottky diode can be described from capacitance-voltage characteristic of the samples and different diode parameters can be extracted from it.

  14. High charge-discharge performance of Pb0.98La0.02(Zr0.35Sn0.55Ti0.10)0.995O3 antiferroelectric ceramics

    NASA Astrophysics Data System (ADS)

    Xu, Chenhong; Liu, Zhen; Chen, Xuefeng; Yan, Shiguang; Cao, Fei; Dong, Xianlin; Wang, Genshui

    2016-08-01

    The energy storage performance and charge-discharge properties of Pb0.98La0.02(Zr0.35Sn0.55Ti0.10)0.995O3 (PLZST) antiferroelectric ceramics were investigated through directly measuring the hysteresis loops and pulse discharge current-time curves. The energy density only varies 0.2% per degree from 25 °C to 85 °C, and the energy efficiency maintains at about 90%. Furthermore, an approximate calculating model of maximum power density pmax was established for the discharge process. Under a relatively high working electric field (8.2 kV/mm), this ceramics possess a greatly enhanced power density of 18 MW/cm3. Moreover, the pulse power properties did not show degradation until 1500 times of charge-discharge cycling. The large released energy density, high energy efficiency, good temperature stability, greatly enhanced power density, and excellent fatigue endurance combined together make this PLZST ceramics an ideal candidate for pulse power applications.

  15. Ozone-concentration and pulmonary-response relationships for 6. 6-hour exposures with five hours of moderate exercise to 0. 08, 0. 10, and 0. 12 ppm

    SciTech Connect

    Horstman, D.H.; Folinsbee, L.J.; Ives, P.J.; Salaam, S.A.; McDonnell, W.F.

    1990-01-01

    The magnitudes of pulmonary responses the authors previously observed (1) following 6.6-h exposure to 0.12 ppm ozone (O{sub 3}) suggested that responses would also occur with similar exposures at lower O{sub 3} concentrations. The objective of the study was to determine the extent of pulmonary function decrements, respiratory discomfort, and increased airway reactivity to methacholine induced by exposure to O{sub 3} below 0.12 ppm. Separate 6.6-h chamber exposures to 0.00, 0.08, 0.10, and 0.12 ppm O3 included six 50-min periods of moderate exercise (VE = 39 L/min, HR = 115 bpm, and VO2 = 1.5 L/min). Each exercise period was followed by 10 min of rest. A 35-min lunch break was included midway through the exposure. Although not intended as an exact simulation, the overall duration, intensity, and metabolic requirements of the exercise performed were representative of a day of moderate to heavy work or play. Preexposure FEV, averaged 4.39 L, and essentially no change (+0.03 L) occurred with exposure to 0.00 ppm O{sub 3}. Significant decreases (p<0.01) of -0.31, -0.30, and -0.54 L were observed with exposures to 0.08, 0.10, and 0.12 ppm, respectively. The study concludes that exposure to O{sub 3} at levels often found in ambient air while engaged in activity representative of a typical day of moderate to heavy work or play induced clinically meaningful pulmonary responses.

  16. Drug Resistance of Enteric Bacteria VI. Introduction of Bacteriophage P1CM into Salmonella typhi and Formation of P1dCM and F-CM Elements

    PubMed Central

    Kondo, Eiko; Mitsuhashi, Susumu

    1966-01-01

    Kondo, Eiko (Gunma University, Maebashi, Japan), and Susumu Mitsuhashi. Drug resistance of enteric bacteria. VI. Introduction of bacteriophage P1CM into Salmonella typhi and formation of P1dCM and F-CM elements. J. Bacteriol. 91:1787–1794. 1966.—Bacteriophage P1CM was introduced into Salmonella typhi by means of both phage infection and conjugation with Escherichia coli F+ lysogenic for the phage. Upon incubation with a P1CM phage lysate, S. typhi and S. abony yield CMr cells which are lysogenic for P1CM, but S. typhimurium LT2 does not. The P1CM phage is adsorbed slightly to S. typhi, but no infectious centers are formed when the phage is plated on this strain. Tests on P1CM-adsorbing capacity of the S. typhi P1CM+ strain and on plaque formation and transduction ability of the recovered phage from this strain indicated that the cell and the phage population did not have any special advantage over the original cell and phage population. Conjugation of S. typhi with E. coli F+ carrying P1CM+ gave three types of S. typhi CMr clones: those which carry the whole P1CM phage, those with the P1dCM element, and those with nontransferable CMr. The second type has the F factor and is sensitive to f phages in spite of its typical behavior, serologically and biochemically, as S. typhi. It can donate the P1dCM and F+ characters to E. coli F− or F−/P1 strains. As a consequence of conjugation with the E. coli F+ strain, the CMr character of the third type of S. typhi, the nontransferable CMr element, acquired conjugational transferability, owing to the formation of the element, F-CM. This element can be transferred to an E. coli F− strain at a very high frequency (ca. 100). Both the F and CMr determinants are jointly transduced with P1 phage and are jointly eliminated by acridine dye treatment. PMID:5327907

  17. Invariant Temperature Sensitivity of Soil Respiration with Depth

    NASA Astrophysics Data System (ADS)

    Hicks Pries, C.; Torn, M. S.; Castanha, C.; Porras, R. C.

    2015-12-01

    Over half of global soil organic carbon (SOC) is stored in subsurface soils (>30 cm), but little is known about the vulnerability of this deep SOC to climate change. Most soil warming experiments have only warmed surface soils, so the temperature sensitivity of deeper SOC and its potential to generate a positive feedback to climate change is undetermined. We are currently investigating how SOC down to 1 m deep responds to experimental in situ soil warming (+4°C). Our field site is a coniferous forest in the foothills of the Sierra Nevada in California, USA, whose soils are sandy, mixed, mesic Ultic Haploxeralfs. Our objectives are to understand (1) how the mechanisms controlling SOC turnover differ with depth and (2) how the temperature sensitivity of soil respiration differs by depth. Warming began in October 2013, and we have successfully warmed 1 m of the soil profile to 4°C (±0.5) above ambient temperatures at each depth and maintained this warming throughout different seasons. We have taken monthly surface CO2 flux measurements and monthly gas samples from stainless steel tubes at 15, 30, 50, 70, and 90 cm depths. We have collected soil water from tension lysimeters at 30 and 70 cm after large rain events. Warming has increased CO2 production at all depths of the warmed plots. Warming has also significantly increased soil respiration from the surface by 39% relative to the control and increased concentrations of dissolved organic carbon in soil water at both depths. The apparent Q10 of surface soil respiration and CO2 production at all depths is greater than 2, indicating that decomposition is similarly temperature sensitive at all depths. This study is one of the first to test whole-profile SOC responses to warming and shows that deep soil carbon is equally vulnerable to climate change in these upland mineral soils.

  18. A correlation between the H I 21-cm absorption strength and impact parameter in external galaxies

    NASA Astrophysics Data System (ADS)

    Curran, S. J.; Reeves, S. N.; Allison, J. R.; Sadler, E. M.

    2016-07-01

    By combining the data from surveys for H I 21-cm absorption at various impact parameters in near-by galaxies, we report an anti-correlation between the 21-cm absorption strength (velocity integrated optical depth) and the impact parameter. Also, by combining the 21-cm absorption strength with that of the emission, giving the neutral hydrogen column density, N_{H I}, we find no evidence that the spin temperature of the gas (degenerate with the covering factor) varies significantly across the disc. This is consistent with the uniformity of spin temperature measured across the Galactic disc. Furthermore, comparison with the Galactic N_{H I} distribution suggests that intervening 21-cm absorption preferentially arises in discs of high inclinations (near face-on). We also investigate the hypothesis that 21-cm absorption is favourably detected towards compact radio sources. Although there is insufficient data to determine whether there is a higher detection rate towards quasar, rather than radio galaxy, sight-lines, the 21-cm detections intervene objects with a mean turnover frequency of < ν _{_TO}rangle ≈ 5× 108 Hz, compared to < ν _{_TO}rangle ≈ 1× 108 Hz for the non-detections. Since the turnover frequency is anti-correlated with radio source size, this does indicate a preferential bias for detection towards compact background radio sources.

  19. Perception of relative depth interval: systematic biases in perceived depth.

    PubMed

    Harris, Julie M; Chopin, Adrien; Zeiner, Katharina; Hibbard, Paul B

    2012-01-01

    Given an estimate of the binocular disparity between a pair of points and an estimate of the viewing distance, or knowledge of eye position, it should be possible to obtain an estimate of their depth separation. Here we show that, when points are arranged in different vertical geometric configurations across two intervals, many observers find this task difficult. Those who can do the task tend to perceive the depth interval in one configuration as very different from depth in the other configuration. We explore two plausible explanations for this effect. The first is the tilt of the empirical vertical horopter: Points perceived along an apparently vertical line correspond to a physical line of points tilted backwards in space. Second, the eyes can rotate in response to a particular stimulus. Without compensation for this rotation, biases in depth perception would result. We measured cyclovergence indirectly, using a standard psychophysical task, while observers viewed our depth configuration. Biases predicted from error due either to cyclovergence or to the tilted vertical horopter were not consistent with the depth configuration results. Our data suggest that, even for the simplest scenes, we do not have ready access to metric depth from binocular disparity.

  20. Carbon storage potential in size-density fractions from semi-natural grassland ecosystems with different productivities over varying soil depths.

    PubMed

    Breulmann, Marc; Boettger, Tatjana; Buscot, François; Gruendling, Ralf; Schulz, Elke

    2016-03-01

    Researchers have increasingly recognised a profound need for more information on SOC stocks in the soil and the factors governing their stability and dynamics. Many questions still remain unanswered about the interplay between changes in plant communities and the extent to which changes in aboveground productivity affect the carbon dynamics in soils through changes in its quantity and quality. Therefore, the main aim of this research was to examine the SOC accumulation potential of semi-natural grasslands of different productivities and determine the distribution of SOM fractions over varying soil depth intervals (0-10, 10-20, 20-30 30-50 50-80 and 80+cm). SOM fractionation was considered as a relative measure of stability to separate SOM associated with clay minerals from SOM of specific light densities less than 2 g cm(-3) (size-density fractionation). Two clay-associated fractions (CF1, <1 μm; and CF2, 1-2 μm) and two light fractions (LF1, <1.8 g cm(-3); and LF2, 1.8-2.0 g cm(-3)) were separated. The stability of these fractions was characterised by their carbon hot water extractability (CHWE) and stable carbon isotope composition. In the semi-natural grasslands studied, most OC was stored in the top 30 cm, where turnover is rapid. Effects of low productivity grasslands became only significantly apparent when fractional OC contributions of total SOM was considered (CF1 and LF1). In deeper soil depths OC was largely attributed to the CF1 fraction of low productivity grasslands. We suggest that the majority of OM in deeper soil depth intervals is microbially-derived, as evidenced by decreasing C/N ratios and decreasing δ(13)C values. The hot water extraction and natural δ(13)C abundance, employed here allowed the characterisation of SOM stabilisation properties, however how climatic changes affect the fate of OM within different soil depth intervals is still unknown. PMID:26745290

  1. Multistep joint bilateral depth upsampling

    NASA Astrophysics Data System (ADS)

    Riemens, A. K.; Gangwal, O. P.; Barenbrug, B.; Berretty, R.-P. M.

    2009-01-01

    Depth maps are used in many applications, e.g. 3D television, stereo matching, segmentation, etc. Often, depth maps are available at a lower resolution compared to the corresponding image data. For these applications, depth maps must be upsampled to the image resolution. Recently, joint bilateral filters are proposed to upsample depth maps in a single step. In this solution, a high-resolution output depth is computed as a weighted average of surrounding low-resolution depth values, where the weight calculation depends on spatial distance function and intensity range function on the related image data. Compared to that, we present two novel ideas. Firstly, we apply anti-alias prefiltering on the high-resolution image to derive an image at the same low resolution as the input depth map. The upsample filter uses samples from both the high-resolution and the low-resolution images in the range term of the bilateral filter. Secondly, we propose to perform the upsampling in multiple stages, refining the resolution by a factor of 2×2 at each stage. We show experimental results on the consequences of the aliasing issue, and we apply our method to two use cases: a high quality ground-truth depth map and a real-time generated depth map of lower quality. For the first use case a relatively small filter footprint is applied; the second use case benefits from a substantially larger footprint. These experiments show that the dual image resolution range function alleviates the aliasing artifacts and therefore improves the temporal stability of the output depth map. On both use cases, we achieved comparable or better image quality with respect to upsampling with the joint bilateral filter in a single step. On the former use case, we feature a reduction of a factor of 5 in computational cost, whereas on the latter use case, the cost saving is a factor of 50.

  2. Conduction time for a 6-cm segment of the ulnar nerve across the elbow: reference values for the 6-cm conduction time test.

    PubMed

    Landau, Mark E; Campbell, William W

    2009-06-01

    Current electrodiagnostic studies for Ulnar nerve mononeuropathy at the elbow have substandard sensitivity and specificity. Reference values for a novel, screening electrodiagnostic test for ulnar nerve mononeuropathy at the elbow were obtained bilaterally from 72 subjects without any upper extremity signs or symptoms. The test used two, 3-cm straight line distances, one proximal, and one distal to the medial epicondyle to avoid a curvilinear measurement. The mean conduction times (CTE) were 1.16 +/- 0.16 milliseconds, 1.23 +/- 0.18 milliseconds, 1.33 +/- 0.24 milliseconds, for subjects 20 to 40, 40 to 60, and >60 years old, respectively. A CTE >1.50 milliseconds, >1.60 milliseconds, and >1.80 milliseconds for each age group would be considered abnormal conferring 98% specificity. The median side-to-side difference of CTE (CTE-diff) was 0.10 milliseconds with a range of 0.00 to 0.55 milliseconds. A CTE-diff >0.45 milliseconds has a specificity of 97%. Potential advantages to this method include straight-line measurement distances to reduce experimental error, and a distance less than 10 cm to improve lesion detection.

  3. [Effect of water depths on hydraulic performance of pond wetlands].

    PubMed

    Guo, Chang-Qiang; Dong, Bin; Liu, Jun-Jie; Liu, Chun-Guo; Feng, Da-Peng; Liu, Fang-Ping

    2014-11-01

    Pond wetlands have been widely used in the treatment of drainage water from paddy fields. However, wetland hydraulic performance and purification effects are affected by many factors, such as water depth, flow rate, aspect ratio and vegetation distribution, and the better understanding of these factors would be helpful to improve the quality of wetland design, operation and management. This paper analyzed the effect of three different water depths (20, 40 and 60 cm) on the hydraulic performance of pond wetland through the dye tracer experiments with Rhodamine WT. The hydraulic indices, i. e., effective volume ratio, nominal serial complete mixing tanks (N), hydraulic efficiency (λ), were selected for analysis through the hydraulic residence time distribution (RTD) curve. The results showed that the effective volume rate rose from 0.421 to 0.844 and the hydraulic efficiency from 0.281 to 0.604 when the water depth declined from 60 cm to 20 cm. This indicated that the wetland hydraulic performance improved as the water depth decreased. In addition, the hydraulic performance of the first half of the wetland was significantly better than that of the second half. The flow regime of the first half approached complete mixing because of the mixing index (N) approaching 1 and its effective volume rate was above 0.9 when the water depth was relatively low (20 and 40 cm). The normalized RTD curves demonstrated a good agreement between moment analysis parameters and hydraulic parameters, and a great consistency between the hydraulic parameters and moment index which was not affected by tail truncation error. The experimental study concluded that a lower water depth was favorable to improve the hydraulic performance of pond wetlands.

  4. [Effect of water depths on hydraulic performance of pond wetlands].

    PubMed

    Guo, Chang-Qiang; Dong, Bin; Liu, Jun-Jie; Liu, Chun-Guo; Feng, Da-Peng; Liu, Fang-Ping

    2014-11-01

    Pond wetlands have been widely used in the treatment of drainage water from paddy fields. However, wetland hydraulic performance and purification effects are affected by many factors, such as water depth, flow rate, aspect ratio and vegetation distribution, and the better understanding of these factors would be helpful to improve the quality of wetland design, operation and management. This paper analyzed the effect of three different water depths (20, 40 and 60 cm) on the hydraulic performance of pond wetland through the dye tracer experiments with Rhodamine WT. The hydraulic indices, i. e., effective volume ratio, nominal serial complete mixing tanks (N), hydraulic efficiency (λ), were selected for analysis through the hydraulic residence time distribution (RTD) curve. The results showed that the effective volume rate rose from 0.421 to 0.844 and the hydraulic efficiency from 0.281 to 0.604 when the water depth declined from 60 cm to 20 cm. This indicated that the wetland hydraulic performance improved as the water depth decreased. In addition, the hydraulic performance of the first half of the wetland was significantly better than that of the second half. The flow regime of the first half approached complete mixing because of the mixing index (N) approaching 1 and its effective volume rate was above 0.9 when the water depth was relatively low (20 and 40 cm). The normalized RTD curves demonstrated a good agreement between moment analysis parameters and hydraulic parameters, and a great consistency between the hydraulic parameters and moment index which was not affected by tail truncation error. The experimental study concluded that a lower water depth was favorable to improve the hydraulic performance of pond wetlands. PMID:25898628

  5. Structural and dynamic electromagnetic properties of Ni0.27 Cu0.10 Zn0.63 Alx Fe2-x O4

    NASA Astrophysics Data System (ADS)

    Hossen, M. Belal; Hossain, A. K. M. Akther

    2015-08-01

    The influence of Al substitution on the structural and electromagnetic properties of Ni0.27Cu0.10Zn0.63AlxFe2 - xO4; (where x = 0.0 to x = 0.16 with step = 0.02) prepared by the combustion technique, has been investigated. X-ray diffraction analysis confirms the presence of single phase cubic spinel structure without any secondary phase. The lattice constant, theoretical density, bulk density and average grain size decreases with increasing Al content. B-H loops have been traced for all the compositions and the various hysteresis parameters like saturation induction, coercivity, remanance, remanance ratio and power loss have been studied as a function of Al content. The saturation induction and the initial permeability increases with sintering temperature up to 1150 °C where the maximum bulk density is obtained, while for higher sintering temperature they decrease. The variation of complex initial permeability for Al substituted NiCuZn ferrites can be presented as a form of semicircle so called the Cole-Cole plot and the relaxation phenomena were explained with various shapes of the plots. The analysis of complex impedance spectra by an equivalent circuit model were used to separate the grain and grain boundary resistance of various Ni0.27 Cu0.10 Zn0.63 Alx Fe2 - x O4 . The impedance plot showed the first semicircle at high frequency which corresponds to grain effect and the second semicircle at lower frequency which corresponds to grain boundary (conduction phenomenon). Both grain and grain boundary resistance increases with increasing Al content and the relative increase of grain resistance is larger than the grain boundary resistance. The frequency dependent conductivity results support the double (Jonscher's modified) power law,σT (ω) = σ (o) +A1 ω n1 +A2 ω n2 , and the results showed evidence of three types of conduction process at room temperature: (i) low frequency conductivity is due to long-range ordering (frequency independent or its tendency

  6. Structure, phase transition and impedance of Zn1- x Li x O (0.10 ≤ x ≤ 0.70) ceramic

    NASA Astrophysics Data System (ADS)

    Ahmadu, U.; Salaudeen, Islamiyat Temitope

    2016-07-01

    Structural transformations of Li-doped Zn1- x Li x O (0.10 ≤ x ≤ 0.70) which was synthesised by solid-state reaction were investigated. XRD carried out on powder specimens of the samples show that they are polycrystalline in nature with a hexagonal wurtzite structure having minor impurities. The result indicates the maximum limit of substitution of Zn atoms by Li is at x = 0.4. The lattice parameter a reduced from 3.01 to 2.99 Å, while c reduced from 5.21 to 5.19 Å. However, the Zn-O bond length reduced from 1.88 to 1.87 Å for the undoped, to x = 0.60 for the doped, respectively. The c/ a ratio is 1.73 and is almost constant for all samples. The grain size of the (100) peak of the undoped ZnO is 41.73 nm and that of x = 0.10 is 41.76 nm. For x = 0.2-0.70, the grain size is 41.72 nm indicating that the grain size is almost independent of doping. The SEM results indicate a variation of grain size from 2.18 to 5.15 µm for the undoped ZnO to x = 0.50, which shows increase in grain size and reduction in grain boundaries as doping increases. The results show that x = 0.50 has the highest grain size and the one with the highest transition temperature is x = 0.6. DTA results indicate the structural phase transition temperature of the doped ZnO ranged from ~371 to ~409 K and increased as the amount of Li increases. A single arc is observed in all the impedance plots of the ZnO together with the presence of a relaxation process which is non-Debye. The impedance data show reduced resistance with increase in lithium content. A general increase in dielectric constant with increase in lithium content is observed.

  7. On evaluation of depth accuracy in consumer depth sensors

    NASA Astrophysics Data System (ADS)

    Abd Aziz, Azim Zaliha; Wei, Hong; Ferryman, James

    2015-12-01

    This paper presents an experimental study of different depth sensors. The aim is to answer the question, whether these sensors give accurate data for general depth image analysis. The study examines the depth accuracy between three popularly used depth sensors; ASUS Xtion Prolive, Kinect Xbox 360 and Kinect for Windows v2. The main attention is to study on the stability of pixels in the depth image captured at several different sensor-object distances by measuring the depth returned by the sensors within specified time intervals. The experimental results show that the fluctuation (mm) of the random selected pixels within the target area, increases with increasing distance to the sensor, especially on the Kinect for Xbox 360 and the Asus Xtion Prolive. Both of these sensors provide pixels fluctuation between 20mm and 30mm at a sensor-object distance beyond 1500mm. However, the pixel's stability of the Kinect for Windows v2 not affected much with the distance between the sensor and the object. The maximum fluctuation for all the selected pixels of Kinect for Windows v2 is approximately 5mm at sensor-object distance of between 800mm and 3000mm. Therefore, in the optimal distance, the best stability achieved.

  8. A comparative study of the growth of Tetraselmis sp. in large scale fixed depth and decreasing depth raceway ponds.

    PubMed

    Das, Probir; Thaher, Mahmoud Ibrahim; Hakim, Mohammed Abdul Quadir Mohd Abdul; Al-Jabri, Hareb Mohammed S J; Alghasal, Ghamza Saed H S

    2016-09-01

    In this study, an alternative approach was proposed where excess seawater would be added only during inoculation (DD) rather than daily addition (FD). Growth and metabolite contents of Tetraselmis sp. weren't affected for daily increase of 2% NaCl salinity. Tetraselmis sp. was then cultured in DD and FD pond. In DD pond, initial culture depth was 23.5cm and its depth reduced as no water was added; for FD pond, everyday sterilized seawater was added to maintain 20cm depth. DD pond had higher biomass productivity compared to FD pond, until DD pond was deeper than FD pond; metabolite content and FAME profile of Tetraselmis sp. were also similar in both cultures. Therefore, considering the simplicity in operation, halo tolerant microalgae can be grown in DD pond method. PMID:27235973

  9. Pressure distributions obtained on a 0.10-scale model of the Space Shuttle Orbiter's forebody in the Ames Unitary Plan Wind Tunnel

    NASA Technical Reports Server (NTRS)

    Siemers, P. M., III; Henry, M. W.

    1986-01-01

    Pressure distribution test data obtained on a 0.10-scale model of the forward fuselage of the Space Shuttle Orbiter are presented without analysis. The tests were completed in the Ames Unitary Wind Tunnel (UPWT). The UPWT tests were conducted in two different test sections operating in the continuous mode, the 8 x 7 feet and 9 x 7 feet test sections. Each test section has its own Mach number range, 1.6 to 2.5 and 2.5 to 3.5 for the 9 x 7 feet and 8 x 7 feet test section, respectively. The test Reynolds number ranged from 1.6 to 2.5 x 10 to the 6th power ft and 0.6 to 2.0 x 10 to the 6th power ft, respectively. The tests were conducted in support of the development of the Shuttle Entry Air Data System (SEADS). In addition to modeling the 20 SEADS orifices, the wind-tunnel model was also instrumented with orifices to match Development Flight Instrumentation (DFI) port locations that existed on the Space Shuttle Columbia (OV-102) during the Orbiter Flight test program. This DFI simulation has provided a means for comparisons between reentry flight pressure data and wind-tunnel and computational data.

  10. The experimental cascade curves of EAS at E sub 0 10(17) eV obtained by the method of detection of Cherenkov pulse shape

    NASA Technical Reports Server (NTRS)

    Fomin, Y. A.; Kalmykov, G. B.; Khristiansen, M. V.; Motova, M. V.; Nechin, Y. A.; Prosin, V. V.; Zhukov, V. Y.; Efimov, N. N.; Grigoriev, V. M.; Nikiforova, E. S.

    1985-01-01

    The individual cascade curves of EAS with E sub 0 10 to the 17th power eV/I to 3/ were studied by detection of EAS Cherenkov light pulses. The scintillators located at the center of the Yakutsk EAS array within a 500-m radius circle were used to select the showers and to determine the main EAS parameters. The individual cascade curves N(t) were obtained using the EAS Cherenkov light pulses satisfying the following requirements: (1) the signal-to-noise ratio fm/delta sub n 15, (2) the EAS axis-detector distance tau sub 350 m, (3) the zenith angle theta 30 deg, (4) the probability for EAS to be detected by scintillators W 0.8. Condition (1) arises from the desire to reduce the amplitude distortion of Cherenkov pulses due to noise and determines the range of EAS sizes, N(t). The resolution times of the Cherenkov pulse shape detectors are tau sub 0 approx. 23 ns which results in distortion of a pulse during the process of the detection. The distortion of pulses due to the finiteness of tau sub 0 value was estimated. It is shown that the rise time of pulse becomes greater as tau sub 0.5/tau sub 0 ratio decreases.

  11. Identifying the sources of ferromagnetism in sol-gel synthesized Zn1-xCoxO (0≤x≤0.10) nanoparticles

    NASA Astrophysics Data System (ADS)

    Beltrán, J. J.; Barrero, C. A.; Punnoose, A.

    2016-08-01

    We have carefully investigated the structural, optical and electronic properties and related them with changes in the magnetism of sol-gel synthesized Zn1-xCoxO (0≤x≤0.10) nanoparticles. Samples with x≤0.05 were free of spurious phases. Samples with x≤0.03 were found to be with only high spin Co2+ ions into ZnO structure, whereas sample with x=0.05, exhibited the presence of high spin Co2+ and low spin Co3+. We found that the intensity of the main EPR peak associated with Co2+ varies with the nominal Co content in a similar manner as the saturation magnetization and coercive field do. These results point out that the ferromagnetism in these samples should directly be correlated with the presence of divalent cobalt ions. Bound magnetic polaron (BMP) model and the charge transfer model are insufficient to explain the ferromagnetic properties of Zn1-xCoxO nanoparticles. The room temperature ferromagnetism (RTFM) may be originated from a combination of several factors such as the interaction of high spin Co2+ ions, perturbation/alteration and/or changes in the electronic structure of ZnO close to the valence band edge and grain boundary effects.

  12. Dielectric characterization of (1-x)PMN-xPT (x = 0.07 and 0.10) ceramics synthesized by an ethylene glycol-based soft chemical route.

    PubMed

    Tailor, Hamel N; Bokov, Alexei A; Ye, Zuo-Guang

    2011-09-01

    Materials based on relaxor ferroelectrics have become one of the most important families of functional materials being explored for such applications as sensors/actuators, micro-electromechanical systems (MEMS), non-volatile random access memories, and high-energy-density capacitors. Fabrication of high-quality relaxor-based ceramics remains, however, a challenging task. In this work, a new soft chemical synthetic method for the preparation of the complex perovskite-based relaxor ferroelectric solid solutions, (1-x)Pb(Mg(1/3)Nb(2/3))O(3)-xPbTiO(3) was developed using ethylene glycol as the solvent. Ceramics with compositions of x = 0.07 and 0.10 were prepared and it was found that a 10% stoichiometric excess of Pb(2+) was required to compensate for lead oxide volatility at the high temperatures used for sintering. The ceramics produced by this method show excellent dielectric properties at room temperature, such as a high dielectric constant (~20 000) and low loss over a large temperatures range (tan δ < 0.01 between 20 and 200°C). The temperature dependence of the dielectric constant exhibits typical relaxor ferroelectric behavior, fitting a quadratic law which describes the high-temperature slope of ε'(T) peak. The frequency dispersion of the temperature of maximum permittivity satisfies the Vogel-Fulcher law.

  13. Medium-depth chemical peels.

    PubMed

    Monheit, G D

    2001-07-01

    The combination medium-depth chemical peel (Jessner's solution +35% TCA) has been accepted as a safe, reliable, and effective method for the treatment of moderate photoaging skin. This article discusses the procedure in detail, including postoperative considerations. PMID:11599398

  14. Teaching Depth of Field Concept

    ERIC Educational Resources Information Center

    Ross, Frederick C.; Smith, Rodney J.

    1978-01-01

    This activity utilizes an overhead projector, a wax pencil, and a petri-dish to demonstrate the depth of field concept to students learning the use of the microscope. Illustrations and directions are included. (MA)

  15. Comparative depths of cure among various curing light types and methods.

    PubMed

    Soh, M S; Yap, Adrian U J; Siow, K S

    2004-01-01

    This study evaluated the depth of cure associated with commercial LEDs (light-emitting diodes) (Elipar FreeLight [FL], 3M-ESPE; GC e-Light [EL], GC), high intensity (Elipar TriLight [TL], 3M-ESPE) and very high intensity (Astralis 10 [AS], Ivoclar Vivadent) Quartz Tungsten Halogen (QTH) curing lights. Depth of cure of the various lights/curing modes were compared to a conventional QTH light (Max [Mx], Dentsply-Caulk). Ten exposure regimens were investigated: FL1 - 400 mW/cm2 [40 seconds]; FL2 - 0-400 mW/cm2 [12 seconds] --> 400 mW/cm2 [28 seconds]; EL1 - 750 mW/cm2 [10 pulses x 2 seconds], EL2 - 350 mW/cm2 [40 seconds]; EL3 - 600 mW/cm2 [20 seconds]; EL4 - 0 - 600 mW/cm2 [20 seconds] --> 600 mW/cm2 [20 seconds]; TL1 - 800 mW/cm2 [40 seconds]; TL2 - 100- 800 mW/cm2 [15 seconds] --> 800 mW/cm2 [25 seconds]; AS1 - 1200 mW/cm2 [10 seconds]; MX - 400 mW/cm2 [40 seconds]. Depth of cure was determined by penetration, scraping and microhardness techniques. The results were analyzed using one-way ANOVA/Scheffe's post-hoc test and Pearson's correlation at significance level 0.05 and 0.01, respectively. All light curing regimens met the ISO depth of cure requirement of 1.5 mm with the exception of EL1-EL3 with the microhardness technique. Curing with most modes of EL resulted in significantly lower depths of cure than the control [MX]. No significant difference in depth of cure was observed among the control and the two modes of FL. Curing with TL1 resulted in significantly greater depth of cure compared to MX with all testing techniques. No significant difference in depth of cure was observed between the control and AS1 for all testing techniques except for the penetration technique. The depth of composite cure is light unit and exposure mode dependent. Scraping and penetration techniques were found to correlate well but tend to overestimate depth of cure compared to microhardness.

  16. Depth perception of illusory surfaces.

    PubMed

    Kogo, Naoki; Drożdżewska, Anna; Zaenen, Peter; Alp, Nihan; Wagemans, Johan

    2014-03-01

    The perception of an illusory surface, a subjectively perceived surface that is not given in the image, is one of the most intriguing phenomena in vision. It strongly influences the perception of some fundamental properties, namely, depth, lightness and contours. Recently, we suggested (1) that the context-sensitive mechanism of depth computation plays a key role in creating the illusion, (2) that the illusory lightness perception can be explained by an influence of depth perception on the lightness computation, and (3) that the perception of variations of the Kanizsa figure can be well-reproduced by implementing these principles in a model (Kogo, Strecha, et al., 2010). However, depth perception, lightness perception, contour perception, and their interactions can be influenced by various factors. It is essential to measure the differences between the variation figures in these aspects separately to further understand the mechanisms. As a first step, we report here the results of a new experimental paradigm to compare the depth perception of the Kanizsa figure and its variations. One of the illusory figures was presented side-by-side with a non-illusory variation whose stereo disparities were varied. Participants had to decide in which of these two figures the central region appeared closer. The results indicate that the depth perception of the illusory surface was indeed different in the variation figures. Furthermore, there was a non-linear interaction between the occlusion cues and stereo disparity cues. Implications of the results for the neuro-computational mechanisms are discussed.

  17. Lessons Learned From CM-2 Modal Testing and Analysis

    NASA Technical Reports Server (NTRS)

    McNelis, Mark E.; Goodnight, Thomas W.; Carney, Kelly S.; Otten, Kim D.

    2002-01-01

    The Combustion Module-2 (CM-2) is a space experiment that launches on Shuttle mission STS-107 in the SPACEHAB Double Research Module. The CM-2 flight hardware is installed into SPACEHAB single and double racks. The CM-2 flight hardware was vibration tested in the launch configuration to characterize the structure's modal response. Cross-orthogonality between test and analysis mode shapes were used to assess model correlation. Lessons learned for pre-test planning and model verification are discussed.

  18. Energy Levels of the Nitrate Radical Below 2000 CM-1

    NASA Astrophysics Data System (ADS)

    Stanton, J. F.; Simmons, C. S.

    2012-06-01

    Highly sophisticated quantum chemistry techniques have been employed to build a three-state diabatic Hamiltonian for the nitrate radical (NO_3). Eigenvalues of this Hamiltonian (which includes effects beyond the Born-Oppenheimer approximation) are consistent with the known ``vibrational'' levels of NO_3 up to ca. 2100 cm-1 above the zero-point level; with a small empirical adjustment of the diabatic coupling strength, calculated levels are within 20 cm-1 of the measured level positions for those that have been observed experimentally. Of the eleven states with e' symmetry calculated below 2000 cm-1, nine of these have been observed either in the gas phase by Hirota and collaborators as well as Neumark and Johnston, or in frozen argon by Jacox. However, the Hamiltonian produces two levels that have not been seen experimentally: one calculated to lie at 1075 cm-1 (which is the third e' state, above ν_4 and 2ν_4) and another at 1640 cm-1 which is best assigned as one of the two e' sublevels of 4ν_4. A significant result is that the state predicted at 1075 cm-1 is not far enough above the predicted 2ν_4 level (777 cm-1 v. ca. 760 cm-1 from experiment) to be plausibly assigned as 3ν_4 (which is at 1155 cm-1: experimental position: 1173 cm-1), nor is its nodal structure consistent with such an idea. Rather, it is quite unambiguously the ν_3 level. Given the fidelity of the results generated by this model Hamiltonian as compared to experiment, it can safely be concluded that the prominent infrared band seen at 1492 cm-1 (corresponding to a calculated level at 1500 cm-1) is not ν_3, but rather a multiquantum state best viewed as a sublevel of the ν_3 + ν_4 combination.

  19. Effects of electron irradiation and temperature on 1 ohm-cm and 10 ohm-cm silicon solar cells

    NASA Technical Reports Server (NTRS)

    Nicoletta, C. A.

    1973-01-01

    One OHM-cm and 10 OHM-cm silicon solar cells were exposed to 1.0 MeV electrons at a fixed flux of 10 to the 11th power e/sq cm/sec and fluences of 10 to the 13th power, 10 to the 14th power and 10 to the 15th power e/sq.cm. 1-V curves of the cells were made at room temperature, - 63 C and + or - 143 C after each irradiation. A value of 139.5 mw/sq cm was used as AMO incident energy rate per unit area. The 10 OHM-cm cells appear more efficient than 1 OHM-cm cells after exposure to a fluence greater than 10 to the 14th power e/sq cm. The 1.0 MeV electron damage coefficients for both 1 OHM-cm and 10 OHM-cm cells are somewhat less than those for previously irradiated cells at room temperature. The values of the damage coefficients increase as the cell temperatures decrease. Efficiencies pertaining to maximum power output are about the same as those of n on p silicon cells evaluated previously.

  20. Cosmic-Ray Muon Intensity Deep Underground versus Depth

    NASA Astrophysics Data System (ADS)

    Meyer, B. S.; Sellschop, J. P. F.; Crouch, M. F.; Kropp, W. R.; Sobel, H. W.; Gurr, H. S.; Lathrop, J.; Reines, F.

    Cosmic-ray muons produced in the earth's atmosphere were measured at a depth of 8.71×104 g cm-2 with a large-area (170 m2) liquid-scintillation-detector hodoscope. These data taken together with those of other workers lead to an improved muon vertical-depth intensity curve, Iv(h)=aμe-h/λ, where Iv(h)= vertical intensity, aμ=(1.04-0.12+0.21)×10-6 cm-2 sec-1 sr-1, λ=(8.04-0.20+0.36)×104 g cm-2, and h = depth in g cm-2. A comparison of these results with those expected from the sea-level muon spectra via an improved calculation may indicate the need for an increased energy loss, probably via the photonuclear interaction as suggested by Keuffel el al. The results are not inconsistent with the presence of the X process of Keuffel et al.

  1. Large-Scale Surveys of Snow Depth on Arctic Sea Ice from Operation IceBridge

    NASA Technical Reports Server (NTRS)

    Kurtz, Nathan T.; Farrell, Sinead L.

    2011-01-01

    We show the first results of a large ]scale survey of snow depth on Arctic sea ice from NASA fs Operation IceBridge snow radar system for the 2009 season and compare the data to climatological snow depth values established over the 1954.1991 time period. For multiyear ice, the mean radar derived snow depth is 33.1 cm and the corresponding mean climatological snow depth is 33.4 cm. The small mean difference suggests consistency between contemporary estimates of snow depth with the historical climatology for the multiyear ice region of the Arctic. A 16.5 cm mean difference (climatology minus radar) is observed for first year ice areas suggesting that the increasingly seasonal sea ice cover of the Arctic Ocean has led to an overall loss of snow as the region has transitioned away from a dominantly multiyear ice cover.

  2. "The 5 cm Rule": Biopower, Sexuality and Schooling

    ERIC Educational Resources Information Center

    Allen, Louisa

    2009-01-01

    This paper explores "the 5 cm rule", a regulation around student contact discovered during an investigation of the sexual culture of schooling with 16-19-year-olds in New Zealand. Implemented to stem "inappropriate and unwanted" touching, it stipulates that students must maintain a physical distance of 5 cm at all times. It is argued this rule…

  3. Design and Performance of 40 cm Ion Optics

    NASA Technical Reports Server (NTRS)

    Soulas, George C.

    2001-01-01

    A 40 cm ion thruster is being developed at the NASA Glenn Research Center to obtain input power and propellant throughput capabilities of 10 kW and 550 kg. respectively. The technical approach here is a continuation of the "derating" technique used for the NSTAR ion thruster. The 40 cm ion thruster presently utilizes the NSTAR ion optics aperture geometry to take advantage of the large database of lifetime and performance data already available. Dome-shaped grids were chosen for the design of the 40 cm ion optics because this design is naturally suited for large-area ion optics. Ion extraction capabilities and electron backstreaming limits for the 40 cm ion optics were estimated by utilizing NSTAR 30 cm ion optics data. A preliminary service life assessment showed that the propellant throughput goal of 550 kg of xenon may be possible with molybdenum 40 cm ion optics. One 40 cm ion optics' set has been successfully fabricated to date. Additional ion optics' sets are presently being fabricated. Preliminary performance tests were conducted on a laboratory model 40 cm ion thruster.

  4. Effects of proton irradiation and temperature on 1 ohm-cm and 10 ohm-cm silicon solar cells

    NASA Technical Reports Server (NTRS)

    Nicoletta, C. A.

    1973-01-01

    The 1 ohm-cm and 10 ohm-cm silicon solar cells were exposed to 1.0 MeV protons at a fixed flux of 10 to the 9th power P/sq cm-sec and fluences of 10 to the 10th power, 10 to the 11th power, 10 to the 12th power and 3 X 10 to the 12th power P/sq cm. I-V curves of the cells were made at room temperature, 65 C and 165 C after each irradiation. A value of 139.5 mw/sq cm was taken as AMO incident energy rate per unit area. Degradation occurred for both uncovered 1 ohm-cm and 10 ohm-cm cells. Efficiencies are generally higher than those of comparable U.S. cells tested earlier. Damage (loss in maximum power efficiency) with proton fluence is somewhat higher for 10 ohm-cm cells, measured at the three temperatures, for fluences above 2 X 10 to the 11th power P/sq cm. Cell efficiency, as expected, changes drastically with temperature.

  5. Monitoring the Depth of Anaesthesia

    PubMed Central

    Musizza, Bojan; Ribaric, Samo

    2010-01-01

    One of the current challenges in medicine is monitoring the patients’ depth of general anaesthesia (DGA). Accurate assessment of the depth of anaesthesia contributes to tailoring drug administration to the individual patient, thus preventing awareness or excessive anaesthetic depth and improving patients’ outcomes. In the past decade, there has been a significant increase in the number of studies on the development, comparison and validation of commercial devices that estimate the DGA by analyzing electrical activity of the brain (i.e., evoked potentials or brain waves). In this paper we review the most frequently used sensors and mathematical methods for monitoring the DGA, their validation in clinical practice and discuss the central question of whether these approaches can, compared to other conventional methods, reduce the risk of patient awareness during surgical procedures. PMID:22163504

  6. Development of ferroelectric correlations in the quantum paraelectric and antiferrodistortive regimes in BaxSr1-xTiO3 (x ≤ 0.10)

    NASA Astrophysics Data System (ADS)

    Hassnain Jaffari, G.; Mehmood, Zahid; Iqbal, Asad M.; Hasanain, S. K.; Ismat Shah, S.

    2014-08-01

    The dielectric response ɛ ( T ) of BaxSr1-xTiO3 (x ≤ 0.1) for compositions at and below the critical composition for the ferroelectric transition has been studied. With progressive Ba substitution, the growth of ferroelectric correlations and the weakening of the Antiferrodistortive (AFD) and the quantum paraelectric (QPE) effects have been studied by monitoring the changes in both the in and out of phase parts of the dielectric response. For the compositions close to pure SrTiO3 (x = 0 and x = 0.02), the temperature dependence exhibits a continuous rise in the in-phase part and no ferroelectric peak, consistent with the QPE behavior. With increasing Ba substitution, the low temperature behavior of the in phase part ɛ ' progressively changes from a continuous rise to exhibit a weak maximum and finally to a well developed cusp. For higher Ba concentrations, the low temperature peak (T ˜ 50K), which corresponds to ferroelectric correlations, becomes increasingly sharper until at the critical composition, x = 0.10, the system shows a single well defined ferroelectric peak. However, the out of phase response of the x = 0.1 composition exhibited a succession of three BaTiO3 type ferroelectric transitions. For x ≤ 0.04, the out of phase part shows evidence of an ordering around T ˜ 100K, which is the expected AFD ordering temperature. The deviations of the ɛ ' ( T ) data from the Curie-Weiss law have been analyzed within the frame work of two different theoretical models. It was determined that the dielectric behavior for lower concentrations of Ba (up to x ≤ 0.08) was explainable in terms of a model of non-interacting regions which are themselves homogeneously polarized and undergo a second order phase transition. For the phase boundary composition, i.e., x = 0.1, on the other hand, the data are explainable in terms of the Sherrington and Kirkpatrick model which includes the effects of weak correlations between the polar regions characterized by a glassy

  7. Flexible depth of field photography.

    PubMed

    Kuthirummal, Sujit; Nagahara, Hajime; Zhou, Changyin; Nayar, Shree K

    2011-01-01

    The range of scene depths that appear focused in an image is known as the depth of field (DOF). Conventional cameras are limited by a fundamental trade-off between depth of field and signal-to-noise ratio (SNR). For a dark scene, the aperture of the lens must be opened up to maintain SNR, which causes the DOF to reduce. Also, today's cameras have DOFs that correspond to a single slab that is perpendicular to the optical axis. In this paper, we present an imaging system that enables one to control the DOF in new and powerful ways. Our approach is to vary the position and/or orientation of the image detector during the integration time of a single photograph. Even when the detector motion is very small (tens of microns), a large range of scene depths (several meters) is captured, both in and out of focus. Our prototype camera uses a micro-actuator to translate the detector along the optical axis during image integration. Using this device, we demonstrate four applications of flexible DOF. First, we describe extended DOF where a large depth range is captured with a very wide aperture (low noise) but with nearly depth-independent defocus blur. Deconvolving a captured image with a single blur kernel gives an image with extended DOF and high SNR. Next, we show the capture of images with discontinuous DOFs. For instance, near and far objects can be imaged with sharpness, while objects in between are severely blurred. Third, we show that our camera can capture images with tilted DOFs (Scheimpflug imaging) without tilting the image detector. Finally, we demonstrate how our camera can be used to realize nonplanar DOFs. We believe flexible DOF imaging can open a new creative dimension in photography and lead to new capabilities in scientific imaging, vision, and graphics. PMID:21088319

  8. Legacy effects of grassland management on soil carbon to depth.

    PubMed

    Ward, Susan E; Smart, Simon M; Quirk, Helen; Tallowin, Jerry R B; Mortimer, Simon R; Shiel, Robert S; Wilby, Andrew; Bardgett, Richard D

    2016-08-01

    The importance of managing land to optimize carbon sequestration for climate change mitigation is widely recognized, with grasslands being identified as having the potential to sequester additional carbon. However, most soil carbon inventories only consider surface soils, and most large-scale surveys group ecosystems into broad habitats without considering management intensity. Consequently, little is known about the quantity of deep soil carbon and its sensitivity to management. From a nationwide survey of grassland soils to 1 m depth, we show that carbon in grassland soils is vulnerable to management and that these management effects can be detected to considerable depth down the soil profile, albeit at decreasing significance with depth. Carbon concentrations in soil decreased as management intensity increased, but greatest soil carbon stocks (accounting for bulk density differences), were at intermediate levels of management. Our study also highlights the considerable amounts of carbon in subsurface soil below 30 cm, which is missed by standard carbon inventories. We estimate grassland soil carbon in Great Britain to be 2097 Tg C to a depth of 1 m, with ~60% of this carbon being below 30 cm. Total stocks of soil carbon (t ha(-1) ) to 1 m depth were 10.7% greater at intermediate relative to intensive management, which equates to 10.1 t ha(-1) in surface soils (0-30 cm), and 13.7 t ha(-1) in soils from 30 to 100 cm depth. Our findings highlight the existence of substantial carbon stocks at depth in grassland soils that are sensitive to management. This is of high relevance globally, given the extent of land cover and large stocks of carbon held in temperate managed grasslands. Our findings have implications for the future management of grasslands for carbon storage and climate mitigation, and for global carbon models which do not currently account for changes in soil carbon to depth with management.

  9. Legacy effects of grassland management on soil carbon to depth.

    PubMed

    Ward, Susan E; Smart, Simon M; Quirk, Helen; Tallowin, Jerry R B; Mortimer, Simon R; Shiel, Robert S; Wilby, Andrew; Bardgett, Richard D

    2016-08-01

    The importance of managing land to optimize carbon sequestration for climate change mitigation is widely recognized, with grasslands being identified as having the potential to sequester additional carbon. However, most soil carbon inventories only consider surface soils, and most large-scale surveys group ecosystems into broad habitats without considering management intensity. Consequently, little is known about the quantity of deep soil carbon and its sensitivity to management. From a nationwide survey of grassland soils to 1 m depth, we show that carbon in grassland soils is vulnerable to management and that these management effects can be detected to considerable depth down the soil profile, albeit at decreasing significance with depth. Carbon concentrations in soil decreased as management intensity increased, but greatest soil carbon stocks (accounting for bulk density differences), were at intermediate levels of management. Our study also highlights the considerable amounts of carbon in subsurface soil below 30 cm, which is missed by standard carbon inventories. We estimate grassland soil carbon in Great Britain to be 2097 Tg C to a depth of 1 m, with ~60% of this carbon being below 30 cm. Total stocks of soil carbon (t ha(-1) ) to 1 m depth were 10.7% greater at intermediate relative to intensive management, which equates to 10.1 t ha(-1) in surface soils (0-30 cm), and 13.7 t ha(-1) in soils from 30 to 100 cm depth. Our findings highlight the existence of substantial carbon stocks at depth in grassland soils that are sensitive to management. This is of high relevance globally, given the extent of land cover and large stocks of carbon held in temperate managed grasslands. Our findings have implications for the future management of grasslands for carbon storage and climate mitigation, and for global carbon models which do not currently account for changes in soil carbon to depth with management. PMID:26854892

  10. Sampling Depths, Depth Shifts, and Depth Resolutions for Bi(n)(+) Ion Analysis in Argon Gas Cluster Depth Profiles.

    PubMed

    Havelund, R; Seah, M P; Gilmore, I S

    2016-03-10

    Gas cluster sputter depth profiling is increasingly used for the spatially resolved chemical analysis and imaging of organic materials. Here, a study is reported of the sampling depth in secondary ion mass spectrometry depth profiling. It is shown that effects of the sampling depth leads to apparent shifts in depth profiles of Irganox 3114 delta layers in Irganox 1010 sputtered, in the dual beam mode, using 5 keV Ar₂₀₀₀⁺ ions and analyzed with Bi(q+), Bi₃(q+) and Bi₅(q+) ions (q = 1 or 2) with energies between 13 and 50 keV. The profiles show sharp delta layers, broadened from their intrinsic 1 nm thickness to full widths at half-maxima (fwhm's) of 8-12 nm. For different secondary ions, the centroids of the measured delta layers are shifted deeper or shallower by up to 3 nm from the position measured for the large, 564.36 Da (C₃₃H₄₆N₃O₅⁻) characteristic ion for Irganox 3114 used to define a reference position. The shifts are linear with the Bi(n)(q+) beam energy and are greatest for Bi₃(q+), slightly less for Bi₅(q+) with its wider or less deep craters, and significantly less for Bi(q+) where the sputtering yield is very low and the primary ion penetrates more deeply. The shifts increase the fwhm’s of the delta layers in a manner consistent with a linearly falling generation and escape depth distribution function (GEDDF) for the emitted secondary ions, relevant for a paraboloid shaped crater. The total depth of this GEDDF is 3.7 times the delta layer shifts. The greatest effect is for the peaks with the greatest shifts, i.e. Bi₃(q+) at the highest energy, and for the smaller fragments. It is recommended that low energies be used for the analysis beam and that carefully selected, large, secondary ion fragments are used for measuring depth distributions, or that the analysis be made in the single beam mode using the sputtering Ar cluster ions also for analysis. PMID:26883085

  11. Room temperature long range ferromagnetic ordering in Ni{sub 0.58}Zn{sub 0.42}Co{sub 0.10}Cu{sub 0.10}Fe{sub 1.8}O{sub 4} nano magnetic system

    SciTech Connect

    Sarveena, Chand, Jagdish; Verma, S.; Singh, M.; Kotnala, R. K.; Batoo, K. M.

    2015-06-24

    The structural and magnetic behavior of sol-gel autocombustion synthesized nanocrystalline Ni{sub 0.58}Zn{sub 0.42}Co{sub 0.10}Cu{sub 0.10}Fe{sub 1.8}O{sub 4} have been investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), Mössbauer spectroscopy and vibrating sample magnetometer(VSM). Sample of high purity and high homogeneity was obtained by calcination at low temperature (500°C) resulting in nanoparticles of average diameter ∼15nm as determined by XRD and further confirmed by TEM. X-ray diffraction (XRD) and selective area diffraction (SAED) confirmed the single phase of the sample. Mössbauer results are supported by magnetization data. Well defined sextets and appearance of hysteresis at room temperature indicate the existence of ferromagnetic coupling at room temperature finding material utility in magnetic storage data. The existence of iron in ferric state confirmed by isomer shift is a clear evidence of improved magnetic properties of the present system.

  12. Influence of depth and sampling time on bacterial community structure in an upland grassland soil.

    PubMed

    Griffiths, Robert I; Whiteley, Andrew S; O'Donnell, Anthony G; Bailey, Mark J

    2003-02-01

    Abstract Temporal and spatial variation of soil bacterial communities was evaluated with both molecular and metabolic profiling techniques. Soil cores (20 cm deep) were taken from an upland grassland in the Scottish Borders (UK) over 3 days in July 1999, and on single days in October 1999, April 2000, and August 2000. Cores were separated into four 5-cm depths to examine vertical spatial distribution. The 0-5-, 5-10- and 10-15-cm samples represented organic horizons whilst the 15-20-cm depths were from a mineral horizon. The potential metabolic activities were analysed using BIOLOG-GN plates, whereas genotypic diversity was evaluated using molecular profiling of amplified 16S rRNA and 16S rDNA gene fragments (denaturing gradient gel electrophoresis (DGGE)). BIOLOG-GN analysis revealed decreased substrate utilisation in the lowest depths, which was coupled with changes in the DNA and RNA DGGE profiles. Seasonal variation was pronounced in the 5-10-cm and 10-15-cm organic horizons for the July samplings whilst the 15-20-cm depths appeared more stable. Potential factors influencing the observed changes in bacterial communities resulting from soil depth and sampling time are discussed.

  13. [Pharmacological effects of CM6912 and its main metabolites].

    PubMed

    Morishita, H; Kushiku, K; Furukawa, T; Yamaki, Y; Izawa, M; Shibazaki, Y; Shibata, U

    1985-07-01

    Pharmacodynamic effects of ethyl 7-chloro-2,3-dihydro-5-(2-fluorophenyl)-2-oxo-1H-1,4- benzodiazepine-3-carboxylate (CM6912), a new benzodiazepine derivative, and its main metabolites (CM6913 = M1, CM7116 = M2) on the peripheral systems were investigated in several species of animals. In pentobarbital-anesthetized rabbits, CM6912 and M2 (1 or 5 mg/kg, i.v.) had little effect on blood pressure, heart rate and ECG, but it slightly reduced the respiration rate. M1 decreased the heart rate without affecting respiration, blood pressure and ECG. In conscious rabbits, CM6912 and M2 (1 mg/kg, i.v.) did not affect respiration, blood pressure, heart rate and ECG, but M1 (1 mg/kg, i.v.) increased the heart rate. CM6912 (5 or 30 mg/kg), when administered orally, also increased heart rate. In pentobarbital-anesthetized dogs, CM6912 and its metabolites (5 mg/kg, i.v.) decreased respiration and heart rate without affecting blood pressure and ECG. CM 6912 (5 mg/kg, i.v.) did not affect cardiovascular responses to the carotid occlusion, vagus stimulation, and pre- and post-ganglionic stimulation of cardiac ganglion in anesthetized dogs. CM6912 and its metabolites affected neither the spontaneous contraction nor the heart rate of isolated rabbit atria. These compounds also had no action on isolated aortic strips from rabbits. CM6912 and its metabolites did not affect the muscle tone of isolated guinea pig intestine, and it had no effects on the contractile responses to acetylcholine, histamine, serotonin and barium chloride. In isolated rabbit intestine, CM6912 and M2 slightly reduced the amplitude of contraction, while M1 had no effect. CM6912 and its metabolites did not affect the spontaneous motility of isolated non-pregnant and pregnant rat uteri as well as in situ non-pregnant rat uterus and isolated guinea pig vas deferens, including the contractile response to adrenaline. CM6912 and M2 relaxed isolated guinea pig trachea strips only at high concentrations. CM6912 and its

  14. Evaluation of CM5 Charges for Condensed-Phase Modeling.

    PubMed

    Vilseck, Jonah Z; Tirado-Rives, Julian; Jorgensen, William L

    2014-07-01

    The recently developed Charge Model 5 (CM5) is tested for its utility in condensed-phase simulations. The CM5 approach, which derives partial atomic charges from Hirshfeld population analyses, provides excellent results for gas-phase dipole moments and is applicable to all elements of the periodic table. Herein, the adequacy of scaled CM5 charges for use in modeling aqueous solutions has been evaluated by computing free energies of hydration (ΔG hyd) for 42 neutral organic molecules via Monte Carlo statistical mechanics. An optimal scaling factor for the CM5 charges was determined to be 1.27, resulting in a mean unsigned error (MUE) of 1.1 kcal/mol for the free energies of hydration. Testing for an additional 20 molecules gave an MUE of 1.3 kcal/mol. The high precision of the results is confirmed by free energy calculations using both sequential perturbations and complete molecular annihilation. Performance for specific functional groups is discussed; sulfur-containing molecules yield the largest errors. In addition, the scaling factor of 1.27 is shown to be appropriate for CM5 charges derived from a variety of density functional methods and basis sets. Though the average errors from the 1.27*CM5 results are only slightly lower than those using 1.14*CM1A charges, the broader applicability and easier access to CM5 charges via the Gaussian program are additional attractive features. The 1.27*CM5 charge model can be used for an enormous variety of applications in conjunction with many fixed-charge force fields and molecular modeling programs. PMID:25061445

  15. Effect of sowing depth on performance of Quercus castaneifolia seedling at different levels of canopy cover.

    PubMed

    Jalali; Gh, A; Ali-Arab, A R; Tabari, M; Akbarinia, M; Hosseini, S M

    2007-04-01

    Due to failure of oak (Quercus castaneifolia C.A. Meyer) natural regeneration, investigation on the best acorn sowing depth of this species under different levels of canopy cover is an important consideration in the Caspian forests, north of Iran. For this purpose, a study site with north-facing slope, clay-loam soil and 260-280 m a.s.l. was chosen in a mixed oak forest. The experiment was conducted as a Complete Randomized Split Plot Design (CRSPD) and the measurements made in one growing season in nine fenced circular 1000 m2 plots with three canopy densities (25, 50 and 75%) at three soil depths (5, 10 and 15 cm). The results revealed that under all canopy densities the maximum seedling emergence occurred at 5 cm depth. The highest emergence rate was appeared in June and the lowest in October. Neither canopy density nor sowing depth did prominently reduce seedling establishment, but a high quotient of mortality likely could be attributed to rodent populations, particularly Hystrix indica. Under all canopies, ground line diameter decreased with increasing sowing depth, the biggest being at 5 cm depth. Neither canopy density nor sowing depth influenced the seedling height. It can be concluded that the best performance of Q. castaneifolia seedling occurs at 5 cm sowing depth and 25% canopy cover.

  16. Ion accelerator systems for high power 30 cm thruster operation

    NASA Technical Reports Server (NTRS)

    Aston, G.

    1982-01-01

    Two and three-grid accelerator systems for high power ion thruster operation were investigated. Two-grid translation tests show that over compensation of the 30 cm thruster SHAG grid set spacing the 30 cm thruster radial plasma density variation and by incorporating grid compensation only sufficient to maintain grid hole axial alignment, it is shown that beam current gains as large as 50% can be realized. Three-grid translation tests performed with a simulated 30 cm thruster discharge chamber show that substantial beamlet steering can be reliably affected by decelerator grid translation only, at net-to-total voltage ratios as low as 0.05.

  17. Eight-cm mercury ion thruster system technology

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The technology status of 8 cm diameter electron bombardment ion thrusters is presented. Much of the technology resulting from the 5 cm diameter thruster has been adapted and improved upon to increase the reliability, durability, and efficiency of the 8 cm thruster. Technology discussed includes: dependence of neutralizer tip erosion upon neutralizer flow rate; impregnated and rolled-foil insert cathode performance and life testing; neutralizer position studies; thruster ion beam profile measurements; high voltage pulse ignition; high utilization ion machined accelerator grids; deposition internal and external to the thruster; thruster vectoring systems; thruster cycling life testing and thruster system weights for typical mission applications.

  18. Titan's surface properties inferred from the seasonal brightness variation at 2-cm wavelength

    NASA Astrophysics Data System (ADS)

    Janssen, M.; Le Gall, A.; Lopes, R.; Lorenz, R.; Malaska, M.; Neish, C.; Solomonidou, A.

    2015-10-01

    A comprehensive calibration and mapping of the thermal microwave emission from Titan's surface at 2.2-cm wavelength has been completed by the passive radiometer included in the Cassini RADAR instrument. A seasonal brightness temperature variation has been determined that is comparable to but slightly smaller than that obtained by Cassini's Composite Infrared Spectrometer (CIRS). This difference has implications for the composition and structure of Titan's surface; namely, that most of Titan's surface is covered by the deposition and possible redistribution of tholin-like atmospheric photochemical products to a depth of at least a meter.

  19. Depth dependent multiple logging system

    SciTech Connect

    Howells, A. P. S.; Angehrn, J. A.; Dienglewicz, A. M.; Viswanathan, R.

    1985-12-03

    An improved well logging technique is provided for more accurately deriving and correlating a plurality of measurements made during a single traversal of a logging instrument through subsurface formations. In one exemplary embodiment, methods and apparatus are provided for deriving a more accurate and precise measurement of depth at which real-time logging measurements are made, and in particular for correcting anomalies occurring in the depth indication from cable stretch, yo-yo of the sonde in the borehole and the like. The more accurate and precise depth measurement is then utilized for generating well logging measurements on a depth-dependent basis, deriving at least some of such measurements in digital form and alternately transmitting to the surface digital and analog representations of such measurements. Furthermore, methods and apparatus are provided for deriving measurements of subsurface earth formation from a plurality of logging instruments combined in a single tool, wherein such measurements are made during a single pass through a borehole with the resultant measurement data correlatively merged, recorded and displayed.

  20. Rotating drum variable depth sampler

    SciTech Connect

    Nance, Thomas A.; Steeper, Timothy J.

    2008-07-01

    A sampling device for collecting depth-specific samples in silt, sludge and granular media has three chambers separated by a pair of iris valves. Rotation of the middle chamber closes the valves and isolates a sample in a middle chamber.

  1. Perceived depth from shading boundaries.

    PubMed

    Kim, Juno; Anstis, Stuart

    2016-01-01

    Shading is well known to provide information the visual system uses to recover the three-dimensional shape of objects. We examined conditions under which patterns in shading promote the experience of a change in depth at contour boundaries, rather than a change in reflectance. In Experiment 1, we used image manipulation to illuminate different regions of a smooth surface from different directions. This manipulation imposed local differences in shading direction across edge contours (delta shading). We found that increasing the angle of delta shading, from 0° to 180°, monotonically increased perceived depth across the edge. Experiment 2 found that the perceptual splitting of shading into separate foreground and background surfaces depended on an assumed light source from above prior. Image regions perceived as foreground structures in upright images appeared farther in depth when the same images were inverted. We also found that the experienced break in surface continuity could promote the experience of amodal completion of colored contours that were ambiguous as to their depth order (Experiment 3). These findings suggest that the visual system can identify occlusion relationships based on monocular variations in local shading direction, but interprets this information according to a light source from above prior of midlevel visual processing.

  2. Pursuing the Depths of Knowledge

    ERIC Educational Resources Information Center

    Boyles, Nancy

    2016-01-01

    Today's state literacy standards and assessments demand deeper levels of knowledge from students. But many teachers ask, "What does depth of knowledge look like on these new, more rigorous assessments? How do we prepare students for this kind of thinking?" In this article, Nancy Boyles uses a sampling of questions from the PARCC and SBAC…

  3. Perceived depth from shading boundaries.

    PubMed

    Kim, Juno; Anstis, Stuart

    2016-01-01

    Shading is well known to provide information the visual system uses to recover the three-dimensional shape of objects. We examined conditions under which patterns in shading promote the experience of a change in depth at contour boundaries, rather than a change in reflectance. In Experiment 1, we used image manipulation to illuminate different regions of a smooth surface from different directions. This manipulation imposed local differences in shading direction across edge contours (delta shading). We found that increasing the angle of delta shading, from 0° to 180°, monotonically increased perceived depth across the edge. Experiment 2 found that the perceptual splitting of shading into separate foreground and background surfaces depended on an assumed light source from above prior. Image regions perceived as foreground structures in upright images appeared farther in depth when the same images were inverted. We also found that the experienced break in surface continuity could promote the experience of amodal completion of colored contours that were ambiguous as to their depth order (Experiment 3). These findings suggest that the visual system can identify occlusion relationships based on monocular variations in local shading direction, but interprets this information according to a light source from above prior of midlevel visual processing. PMID:27271807

  4. Constraining the redshifted 21-cm signal with the unresolved soft X-ray background

    NASA Astrophysics Data System (ADS)

    Fialkov, Anastasia; Cohen, Aviad; Barkana, Rennan; Silk, Joseph

    2016-10-01

    We use the observed unresolved cosmic X-ray background (CXRB) in the 0.5 - 2 keV band and existing upper limits on the 21-cm power spectrum to constrain the high-redshift population of X-ray sources, focusing on their effect on the thermal history of the Universe and the cosmic 21-cm signal. Because the properties of these sources are poorly constrained, we consider hot gas, X-ray binaries and mini-quasars (i.e., sources with soft or hard X-ray spectra) as possible candidates. We find that (1) the soft-band CXRB sets an upper limit on the X-ray efficiency of sources that existed before the end of reionization, which is one-to-two orders of magnitude higher than typically assumed efficiencies, (2) hard sources are more effective in generating the CXRB than the soft ones, (3) the commonly-assumed limit of saturated heating is not valid during the first half of reionization in the case of hard sources, with any allowed value of X-ray efficiency, (4) the maximal allowed X-ray efficiency sets a lower limit on the depth of the absorption trough in the global 21-cm signal and an upper limit on the height of the emission peak, while in the 21-cm power spectrum it sets a minimum amplitude and frequency for the high-redshift peaks, and (5) the existing upper limit on the 21-cm power spectrum sets a lower limit on the X-ray efficiency for each model. When combined with the 21-cm global signal, the CXRB will be useful for breaking degeneracies and helping constrain the nature of high-redshift heating sources.

  5. CM Process Improvement and the International Space Station Program (ISSP)

    NASA Technical Reports Server (NTRS)

    Stephenson, Ginny

    2007-01-01

    This viewgraph presentation reviews the Configuration Management (CM) process improvements planned and undertaken for the International Space Station Program (ISSP). It reviews the 2004 findings and recommendations and the progress towards their implementation.

  6. Benchmarking and performance analysis of the CM-2. [SIMD computer

    NASA Technical Reports Server (NTRS)

    Myers, David W.; Adams, George B., II

    1988-01-01

    A suite of benchmarking routines testing communication, basic arithmetic operations, and selected kernel algorithms written in LISP and PARIS was developed for the CM-2. Experiment runs are automated via a software framework that sequences individual tests, allowing for unattended overnight operation. Multiple measurements are made and treated statistically to generate well-characterized results from the noisy values given by cm:time. The results obtained provide a comparison with similar, but less extensive, testing done on a CM-1. Tests were chosen to aid the algorithmist in constructing fast, efficient, and correct code on the CM-2, as well as gain insight into what performance criteria are needed when evaluating parallel processing machines.

  7. Quantitative molecular biology and gas flux measurements demonstrate soil treatment and depth affects on the distribution and activity of denitrifiers

    NASA Astrophysics Data System (ADS)

    Barrett, M. M.; Jahangir, M.; Cardenas, L.; Khalil, M.; Richards, K. R.; O'Flaherty, V.

    2010-12-01

    The growing industrialisation of agriculture has led to a dramatic increase in organic and inorganic nitrogen (N) fertiliser inputs to agro-ecosystems. This increase has had negative effects on the quality of water ecosystems and greenhouse gas emissions.The study objective was to quantify denitrification and denitrifying microorganisms, using real-time PCR assays of the nitrite reductase(nir) and nitrous oxide reductase(nos) functional gene copy concentrations (GCC g[soil]-1) in Irish agricultural surface and subsoils. Soil cores from 3 soil horizons (A:0-10 cm; B:45-55 cm; C:120-130cm) were amended with 3 alternate N- and C-source amendments (NO3-; NO3-+glucose-C; NO3-+Dissolved Organic Carbon (DOC). Real-time production of N2O and N2 was recorded by gas chromatography in a specialized He/O2 environment. N2O and Total Denitrification (TDN) (N2O+N2) production was generally greater in surface soil (2.052 mg/kg/d TDN) than in subsoils (0.120 mg/kg/d TDN). The abundance of denitrifying nirS, nirK (nir) and nos genes was higher in the surface soil, decreasing with soil depth, except in incubations amended with NO3- and DOC, where the carbon source directly positively affected gene copy numbers and fluxes of N2O and N2 production. C addition increased soil denitrification rates, and resulted in higher N2O/(N2O+N2) ratios in surface soil (0.39) than subsoils (0.005), indicating that the subsoil had higher potential for complete reduction of N2O to N2. In the subsoils, complete reduction of NO3- due to glucose-C and DOC addition was observed. Interestingly, at all 3 soil depths, lower nirK abundance (2.78 105 GCC) was recorded, compared to nirS (1.45 107 GCC), but the overall abundance of nir (S+K) i.e. (1.54 107GCC), corresponded with N2O emission fluxes (3.34 mg/kg/d) Statistical analysis indicates negative correlation between nirK GCC and N2O production, but a strong positive correlation was observed between nirS GCC and N2O. We therefore hypothesize that the

  8. CmWRKY15 Facilitates Alternaria tenuissima Infection of Chrysanthemum.

    PubMed

    Fan, Qingqing; Song, Aiping; Xin, Jingjing; Chen, Sumei; Jiang, Jiafu; Wang, Yinjie; Li, Xiran; Chen, Fadi

    2015-01-01

    Abscisic acid (ABA) has an important role in the responses of plants to pathogens due to its ability to induce stomatal closure and interact with salicylic acid (SA) and jasmonic acid (JA). WRKY transcription factors serve as antagonistic or synergistic regulators in the response of plants to a variety of pathogens. Here, we demonstrated that CmWRKY15, a group IIa WRKY family member, was not transcriptionally activated in yeast cells. Subcellular localization experiments in which onion epidermal cells were transiently transfected with CmWRKY15 indicated that CmWRKY15 localized to the nucleus in vivo. The expression of CmWRKY15 could be markedly induced by the presence of Alternaria tenuissima inoculum in chrysanthemum. Furthermore, the disease severity index (DSI) data of CmWRKY15-overexpressing plants indicated that CmWRKY15 overexpression enhanced the susceptibility of chrysanthemum to A. tenuissima infection compared to controls. To illustrate the mechanisms by which CmWRKY15 regulates the response to A. tenuissima inoculation, the expression levels of ABA-responsive and ABA signaling genes, such as ABF4, ABI4, ABI5, MYB2, RAB18, DREB1A, DREB2A, PYL2, PP2C, RCAR1, SnRK2.2, SnRK2.3, NCED3A, NCED3B, GTG1, AKT1, AKT2, KAT1, KAT2, and KC1were compared between transgenic plants and controls. In summary, our data suggest that CmWRKY15 might facilitate A. tenuissima infection by antagonistically regulating the expression of ABA-responsive genes and genes involved in ABA signaling, either directly or indirectly. PMID:26600125

  9. New results on the ternary fission of 243Cm

    NASA Astrophysics Data System (ADS)

    Heyse, J.; Wagemans, C.; Vermote, S.; Serot, O.; Geltenbort, P.; Soldner, T.; Van Gils, J.

    2005-11-01

    Ternary fission is an important source of He and tritium gas in nuclear reactors and used fuel elements. Therefore a systematic study of the ternary fission yields for 4He and tritons (t) is being performed. In recent years the influence of the excitation energy of the fissioning nucleus on the triton emission probability (t/B) has been investigated for different Cm and Cf isotopes. In this paper we report on new results on the neutron induced fission of 243Cm.

  10. CmWRKY15 Facilitates Alternaria tenuissima Infection of Chrysanthemum

    PubMed Central

    Fan, Qingqing; Song, Aiping; Xin, Jingjing; Chen, Sumei; Jiang, Jiafu; Wang, Yinjie; Li, Xiran; Chen, Fadi

    2015-01-01

    Abscisic acid (ABA) has an important role in the responses of plants to pathogens due to its ability to induce stomatal closure and interact with salicylic acid (SA) and jasmonic acid (JA). WRKY transcription factors serve as antagonistic or synergistic regulators in the response of plants to a variety of pathogens. Here, we demonstrated that CmWRKY15, a group IIa WRKY family member, was not transcriptionally activated in yeast cells. Subcellular localization experiments in which onion epidermal cells were transiently transfected with CmWRKY15 indicated that CmWRKY15 localized to the nucleus in vivo. The expression of CmWRKY15 could be markedly induced by the presence of Alternaria tenuissima inoculum in chrysanthemum. Furthermore, the disease severity index (DSI) data of CmWRKY15-overexpressing plants indicated that CmWRKY15 overexpression enhanced the susceptibility of chrysanthemum to A. tenuissima infection compared to controls. To illustrate the mechanisms by which CmWRKY15 regulates the response to A. tenuissima inoculation, the expression levels of ABA-responsive and ABA signaling genes, such as ABF4, ABI4, ABI5, MYB2, RAB18, DREB1A, DREB2A, PYL2, PP2C, RCAR1, SnRK2.2, SnRK2.3, NCED3A, NCED3B, GTG1, AKT1, AKT2, KAT1, KAT2, and KC1were compared between transgenic plants and controls. In summary, our data suggest that CmWRKY15 might facilitate A. tenuissima infection by antagonistically regulating the expression of ABA-responsive genes and genes involved in ABA signaling, either directly or indirectly. PMID:26600125

  11. Depth dependence determination of the wedge transmission factor for 4--10 MV photon beams

    SciTech Connect

    McCullough, E.C.; Gortney, J.; Blackwell, C.R.

    1988-07-01

    The depth dependence (up to 25 cm) of the in-phantom wedge transmission factor (WTF) has been determined for three medical linear accelerator x-ray beams with energies of 4, 6, and 10 MV containing 15/sup 0/--60/sup 0/ (nominal) brass wedges. All measurements were made with a cylindrical ionization chamber in water, for a field size of 10 x 10 cm/sup 2/ with a source--skin distance of 80 or 100 cm. We conclude that, for the accelerators studied, the WTF factor at depth is less than 2% different from that determined at d/sub max/ (for the nominal wedge angles and photon energies studied) unless the depth of interest is greater than 10 cm. Up to the maximum depth studied (25 cm) the relative wedge factor: that is, wedge factor at depth compared to that determined at d/sub max/ : was about equal to or less than 1.02 for the 15/sup 0/ and 30/sup 0/ wedges and any of the photon beam energies studied. For the seldom utilized combination of a nominal wedge angle in excess of 45/sup 0/ with a depth greater than 10 cm, the WTF at depth can differ from the WTF determined at d/sub max/, by up to 5%. Since the wedge transmission factor is reflective of relative percent dose data, our results also indicate that it is in error to use open field percent depth doses for certain combinations of wedge angle, photon energy, and depth.

  12. Depth of soil water uptake by tropical rainforest trees during dry periods: does tree dimension matter?

    PubMed

    Stahl, Clément; Hérault, Bruno; Rossi, Vivien; Burban, Benoit; Bréchet, Claude; Bonal, Damien

    2013-12-01

    Though the root biomass of tropical rainforest trees is concentrated in the upper soil layers, soil water uptake by deep roots has been shown to contribute to tree transpiration. A precise evaluation of the relationship between tree dimensions and depth of water uptake would be useful in tree-based modelling approaches designed to anticipate the response of tropical rainforest ecosystems to future changes in environmental conditions. We used an innovative dual-isotope labelling approach (deuterium in surface soil and oxygen at 120-cm depth) coupled with a modelling approach to investigate the role of tree dimensions in soil water uptake in a tropical rainforest exposed to seasonal drought. We studied 65 trees of varying diameter and height and with a wide range of predawn leaf water potential (Ψpd) values. We confirmed that about half of the studied trees relied on soil water below 100-cm depth during dry periods. Ψpd was negatively correlated with depth of water extraction and can be taken as a rough proxy of this depth. Some trees showed considerable plasticity in their depth of water uptake, exhibiting an efficient adaptive strategy for water and nutrient resource acquisition. We did not find a strong relationship between tree dimensions and depth of water uptake. While tall trees preferentially extract water from layers below 100-cm depth, shorter trees show broad variations in mean depth of water uptake. This precludes the use of tree dimensions to parameterize functional models.

  13. Polarized and depolarized Raman spectra of liquid carbon disulfide in the pressure range 0-10 kbar. I. Vibration frequencies, C-S bond length, and Fermi resonance

    NASA Astrophysics Data System (ADS)

    Ikawa, S.; Whalley, Edward

    1986-09-01

    The effect of pressure on the polarized and depolarized Raman spectra of liquid carbon disulphide, i.e., the peak frequencies, bandwidths, and relative intensities of both the allowed ν1 and 2ν2 bands and the interaction-induced ν2 and ν3 bands, have been measured at 22 °C up to 10 kbar. This paper discusses the effect of pressure on the frequencies and on the relative isotropic intensity of the ν1 and 2ν2 bands. The frequency of the ν1 band increases linearly with pressure, within the experimental uncertainty, at the rate 0.16±0.01 cm-1 kbar-1, and the frequencies of the ν2, ν3, and 2ν2 bands decrease nonlinearly. The frequency shifts are described by second-order perturbation theory with the molecular anharmonicity and the intermolecular interaction as perturbations. The leading terms of the shifts consist of the same derivative of the interaction potential, multiplied by different anharmonicity constants, and the shifts of the ν1 and 2ν2 bands suggests that the C-S bond length decreases at the rate 2×10-4 Å kbar-1. The relative isotropic intensity of the 2ν2 and ν1 bands increases with pressure at the rate 0.050 kbar-1, whereas the anisotropic 2ν2 intensity relative to the isotropic ν1 intensity is independent of pressure to the experimental precision of ˜0.005. The effect of pressure on the second derivative of the isotropic and anisotropic parts of the polarizability with respect to the bend coordinate was estimated as 1.1×10-43 C m2 V-1 kbar-1 and ˜0, respectively, from these values.

  14. Explosion depths for phreatomagmatic eruptions

    NASA Astrophysics Data System (ADS)

    Valentine, Greg A.; Graettinger, Alison H.; Sonder, Ingo

    2014-05-01

    Subsurface phreatomagmatic explosions can result from the interaction of ascending magma with groundwater. Experiments over a wide range of energies show that for a given energy there is a depth below which an explosion will be contained within the subsurface (not erupt), and there is a corresponding shallower depth that will optimize ejecta dispersal. We combine these relationships with constraints on the energies of phreatomagmatic explosions at maar-diatreme volcanoes and show that most eruptions are likely sourced by explosions in the uppermost ~200 m, and even shallower ones (<100 m) are likely to dominate deposition onto tephra rings. Most explosions below ~200 m will not erupt but contribute to formation of, and to the vertical mixing of materials within, a diatreme (vent structure), with only rare very high energy explosions between ~200 and 500 m erupting. Similar constraints likely apply at other volcanoes that experience phreatomagmatic explosions.

  15. Ultrasonic material hardness depth measurement

    DOEpatents

    Good, Morris S.; Schuster, George J.; Skorpik, James R.

    1997-01-01

    The invention is an ultrasonic surface hardness depth measurement apparatus and method permitting rapid determination of hardness depth of shafts, rods, tubes and other cylindrical parts. The apparatus of the invention has a part handler, sensor, ultrasonic electronics component, computer, computer instruction sets, and may include a display screen. The part handler has a vessel filled with a couplant, and a part rotator for rotating a cylindrical metal part with respect to the sensor. The part handler further has a surface follower upon which the sensor is mounted, thereby maintaining a constant distance between the sensor and the exterior surface of the cylindrical metal part. The sensor is mounted so that a front surface of the sensor is within the vessel with couplant between the front surface of the sensor and the part.

  16. Photon counting compressive depth mapping.

    PubMed

    Howland, Gregory A; Lum, Daniel J; Ware, Matthew R; Howell, John C

    2013-10-01

    We demonstrate a compressed sensing, photon counting lidar system based on the single-pixel camera. Our technique recovers both depth and intensity maps from a single under-sampled set of incoherent, linear projections of a scene of interest at ultra-low light levels around 0.5 picowatts. Only two-dimensional reconstructions are required to image a three-dimensional scene. We demonstrate intensity imaging and depth mapping at 256 × 256 pixel transverse resolution with acquisition times as short as 3 seconds. We also show novelty filtering, reconstructing only the difference between two instances of a scene. Finally, we acquire 32 × 32 pixel real-time video for three-dimensional object tracking at 14 frames-per-second. PMID:24104293

  17. Ultrasonic material hardness depth measurement

    DOEpatents

    Good, M.S.; Schuster, G.J.; Skorpik, J.R.

    1997-07-08

    The invention is an ultrasonic surface hardness depth measurement apparatus and method permitting rapid determination of hardness depth of shafts, rods, tubes and other cylindrical parts. The apparatus of the invention has a part handler, sensor, ultrasonic electronics component, computer, computer instruction sets, and may include a display screen. The part handler has a vessel filled with a couplant, and a part rotator for rotating a cylindrical metal part with respect to the sensor. The part handler further has a surface follower upon which the sensor is mounted, thereby maintaining a constant distance between the sensor and the exterior surface of the cylindrical metal part. The sensor is mounted so that a front surface of the sensor is within the vessel with couplant between the front surface of the sensor and the part. 12 figs.

  18. FINAL REPORT INTEGRATED DM1200 MELTER TESTING OF BUBBLER CONFIGURATIONS USING HLW AZ-101 SIMULANTS VSL-04R4800-4 REV 0 10/5/04

    SciTech Connect

    KRUGER AA; MATLACK KS; GONG W; BARDAKCI T; D'ANGELO NA; LUTZE W; CALLOW RA; BRANDYS M; KOT WK; PEGG IL

    2011-12-29

    This report documents melter and off-gas performance results obtained on the DM1200 HLW Pilot Melter during processing of AZ-101 HLW simulants. The tests reported herein are a subset of six tests from a larger series of tests described in the Test Plan for the work; results from the other tests have been reported separately. The solids contents of the melter feeds were based on the WTP baseline value for the solids content of the feeds from pretreatment which changed during these tests from 20% to 15% undissolved solids resulting in tests conducted at two feed solids contents. Based on the results of earlier tests with single outlet 'J' bubblers, initial tests were performed with a total bubbling rate of 651 pm. The first set of tests (Tests 1A-1E) addressed the effects of skewing this total air flow rate back and forth between the two installed bubblers in comparison to a fixed equal division of flow between them. The second set of tests (2A-2D) addressed the effects of bubbler depth. Subsequently, as the location, type and number of bubbling outlets were varied, the optimum bubbling rate for each was determined. A third (3A-3C) and fourth (8A-8C) set of tests evaluated the effects of alternative bubbler designs with two gas outlets per bubbler instead of one by placing four bubblers in positions simulating multiple-outlet bubblers. Data from the simulated multiple outlet bubblers were used to design bubblers with two outlets for an additional set of tests (9A-9C). Test 9 was also used to determine the effect of small sugar additions to the feed on ruthenium volatility. Another set of tests (10A-10D) evaluated the effects on production rate of spiking the feed with chloride and sulfate. Variables held constant to the extent possible included melt temperature, plenum temperature, cold cap coverage, the waste simulant composition, and the target glass composition. The feed rate was increased to the point that a constant, essentially complete, cold cap was achieved

  19. A practical block detector for a depth encoding PET camera

    SciTech Connect

    Rogers, J.G.; Moisan, C.; Hoskinson, E.M.; Andreaco, M.S.; Williams, C.W.; Nutt, A.

    1995-10-01

    The depth-of-interaction effect in block detectors degrades the image resolution in commercial PET cameras and impedes the natural evolution of smaller, less expensive cameras. A method for correcting the measured position of each detected gamma ray by measuring its depth-of-interaction was tested and found to recover 38% of the lost resolution in a table-top 50 cm diameter camera. To obtain the desired depth sensitivity, standard commercial detectors were modified by a simple and practical process, which is suitable for mass production of the detectors. The impact of the detector modifications on central image resolution and on the ability of the camera to correct for object scatter were also measured.

  20. Radioactivities vs. depth in Apollo 16 and 17 soil

    NASA Technical Reports Server (NTRS)

    Fireman, E. L.; D'Amico, J.; Defelice, J.

    1973-01-01

    The radioactivities of Ar-37, Ar-39, and H-3 measured at a number of depths for Apollo 16 and 17 soil are reported. The Ar-37 activities vs depth in the Apollo 16 drill string increased with depth and reached a broad maximum in the neighborhood of 50 g per sq cm before decreasing. The Ar-39 activities in Apollo 17 soil were higher than in Apollo 16 soil, probably owing to the higher Fe and Ti contents. The H-3 activities in Apollo 16 and 17 soil were quite similar and indicate that the 4 August 1972 flare produced very little H-3 compared to the amount produced by solar flares during the previous 50 years.

  1. Raman spectra and cross sections of ammonia, chlorine, hydrogen sulfide, phosgene, and sulfur dioxide toxic gases in the fingerprint region 400-1400 cm-1

    NASA Astrophysics Data System (ADS)

    Aggarwal, R. L.; Farrar, L. W.; Di Cecca, S.; Jeys, T. H.

    2016-02-01

    Raman spectra of ammonia (NH3), chlorine (Cl2), hydrogen sulfide (H2S), phosgene (COCl2), and sulfur dioxide (SO2) toxic gases have been measured in the fingerprint region 400-1400 cm-1. A relatively compact (<2'x2'x2'), sensitive, 532 nm 10 W CW Raman system with double-pass laser and double-sided collection was used for these measurements. Two Raman modes are observed at 934 and 967 cm-1 in NH3. Three Raman modes are observed in Cl2 at 554, 547, and 539 cm-1, which are due to the 35/35 35/37, and 37/37 Cl isotopes, respectively. Raman modes are observed at 870, 570, and 1151 cm-1 in H2S, COCl2, and SO2, respectively. Values of 3.68 ± 0.26x10-32 cm2/sr (3.68 ± 0.26x10-36 m2/sr), 1.37 ± 0.10x10-30 cm2/sr (1.37 ± 0.10x10-34 m2/sr), 3.25 ± 0.23x10-31 cm2/sr (3.25 ± 0.23x10-35 m2/sr), 1.63 ± 0.14x10-30 cm2/sr (1.63 ± 0.14x10-34 m2/sr), and 3.08 ± 0.22x10-30 cm2/sr (and 3.08 ± 0.22x10-34 m2/sr) were determined for the differential Raman cross section of the 967 cm-1 mode of NH3, sum of the 554, 547, and 539 cm-1 modes of Cl2, 870 cm-1 mode of H2S, 570 cm-1 mode of COCl2, and 1151 cm-1 mode of SO2, respectively, using the differential Raman cross section of 3.56 ± 0.14x10-31 cm2/sr (3.56 ± 0.14x10-35 m2/sr) for the 1285 cm-1 mode of CO2 as the reference.

  2. The effectiveness of cure of LED and halogen curing lights at varying cavity depths.

    PubMed

    Soh, M S; Yap, Adrian U J; Siow, K S

    2003-01-01

    This study compared the effectiveness of cure of two LED (light-emitting diodes) lights (Elipar FreeLight [FL], 3M-ESPE and GC e-Light [EL], GC) to conventional (Max [MX] (control), Dentsply-Caulk), high intensity (Elipar TriLight [TL], 3M-ESPE) and very high intensity (Astralis 10 [AS], Ivoclar Vivadent) halogen lights at varying cavity depths. Ten light curing regimens were investigated. They include: FL1-400 mW/cm2 [40 seconds], FL2-0-400 mW/cm2 [12 seconds] --> 400 mW/cm2 [28 seconds], EL1-750 mW/cm2 [10 pulses x 2 seconds], EL2-350 mW/cm2 [40 seconds], EL3-600 mW/cm2 [20 seconds], EL4-0-600 mW/cm2 [20 seconds] --> 600 mW/cm2 [20 seconds], TL1-800 mW/cm2 [40 seconds], TL2-100-800 mW/cm2 [15 seconds] --> 800 mW/cm2 [25 seconds], AS1-1200 mW/cm2 [10 seconds], MX-400 mW/cm2 [40 seconds]. The effectiveness of cure of the different modes was determined by measuring the top and bottom surface hardness (KHN) of 2-mm, 3-mm and 4-mm thick composite (Z100, [3M-ESPE]) specimens using a digital microhardness tester (n = 5, load = 500 g; dwell time = 15 seconds). Results were analyzed using ANOVA/Scheffe's post-hoc test and Independent Samples t-Test (p < 0.05). For all lights, effectiveness of cure was found to decrease with increased cavity depths. The mean hardness ratio for all curing lights at a depth of 2 mm was found to be greater than 0.80 (the accepted minimum standard). At 3 mm, all halogen lights produced a hardness ratio greater than 0.80 but some LED light regimens did not; and at a depth of 4 mm, the mean hardness ratio observed with all curing lights was less than 0.80. Significant differences in top and bottom KHN values were observed among different curing regimens for the same light and between LED and halogen lights. While curing with most modes of EL resulted in significantly lower top and bottom KHN values than the control (MX) at all depths, the standard mode of FL resulted in significantly higher top and bottom KHN at a depth of 3 mm and 4 mm. The

  3. Cosmological signatures of tilted isocurvature perturbations: reionization and 21cm fluctuations

    SciTech Connect

    Sekiguchi, Toyokazu; Sugiyama, Naoshi; Tashiro, Hiroyuki; Silk, Joseph E-mail: hiroyuki.tashiro@asu.edu E-mail: naoshi@nagoya-u.jp

    2014-03-01

    We investigate cosmological signatures of uncorrelated isocurvature perturbations whose power spectrum is blue-tilted with spectral index 2∼depth as a powerful probe of a highly blue-tilted isocurvature primordial power spectrum. We also study the consequences for 21cm line fluctuations due to neutral hydrogens in minihalos. Combination of measurements of the reionization optical depth and 21cm line fluctuations will provide complementary probes of a highly blue-tilted isocurvature power spectrum.

  4. CM Carbonaceous Chondrite Lithologies and Their Space Exposure Ages

    NASA Technical Reports Server (NTRS)

    Zolensky, Michael; Gregory, Timothy; Takenouchi, Atsushi; Nishiizumi, Kunihiko; Trieman, Alan; Berger, Eve; Le, Loan; Fagan, Amy; Velbel, Michael; Imae, Naoya; Yamaguchi, Akira

    2015-01-01

    The CMs are the most commonly falling C chondrites, and therefore may be a major component of C-class asteroids, the targets of several current and future space missions. Previous work [1] has concluded that CM chondrites fall into at least four distinct cosmic ray space exposure (CRE) age groups (0.1 million years, 0.2 million years, 0.6 million years and greater than 2.0 million years), an unusually large number, but the meaning of these groupings is unclear. It is possible that these meteorites came from different parent bodies which broke up at different times, or instead came from the same parent body which underwent multiple break-up events, or a combination of these scenarios, or something else entirely. The objective of this study is to investigate the diversity of lithologies which make up CM chondrites, in order to determine whether the different exposure ages correspond to specific, different CM lithologies, which permit us to constrain the history of the CM parent body(ies). We have already reported significant petrographic differences among CM chondrites [2-4]. We report here our new results.

  5. Selenographic distribution of apparent crater depth

    NASA Astrophysics Data System (ADS)

    de Hon, R. A.

    If apparent crater depth is a function of crater diameter, then the frequencies of crater depth and diameter should be similar and the distribution of apparent depths of craters on the lunar surface should be random. Apparent depths of complex craters, which range from 0.2 to 4.3 km on the moon, exhibit little correlation with crater diameters. Crater frequency decreases at increasing diameters, but apparent crater depth displays a Gaussian distribution. The average crater depth for all young craters is 1.8 km. The mean depth of craters on the maria is 1.3 km, and the mean depth of craters on the highlands is 2.1 km. A contour map of apparent crater depths exhibits sufficient organization to suggest that the apparent crater depth is correlated to major lunar provinces. In general, regions of shallow craters are associated with basin interiors. Greater apparent depths are associated with highland terrains.

  6. Factors affecting the accuracy of chest compression depth estimation

    PubMed Central

    Kang, Jung Hee; Cha, Won Chul; Chae, Minjung Kathy; Park, Hang A; Hwang, Sung Yeon; Jin, Sang Chan; Lee, Tae Rim; Shin, Tae Gun; Sim, Min Seob; Jo, Ik Joon; Song, Keun Jeong; Rhee, Joong Eui; Jeong, Yeon Kwon

    2014-01-01

    Objective We aimed to estimate the accuracy of visual estimation of chest compression depth and identify potential factors affecting accuracy. Methods This simulation study used a basic life support mannequin, the Ambu man. We recorded chest compression with 7 different depths from 1 to 7 cm. Each video clip was recorded for a cycle of compression. Three different viewpoints were used to record the video. After filming, 25 clips were randomly selected. Health care providers in an emergency department were asked to estimate the depth of compressions while watching the selected video clips. Examiner determinants such as experience and cardiopulmonary resuscitation training and environment determinants such as the location of the camera (examiner) were collected and analyzed. An estimated depth was considered correct if it was consistent with the one recorded. A multivariate analysis predicting the accuracy of compression depth estimation was performed. Results Overall, 103 subjects were enrolled in the study; 42 (40.8%) were physicians, 56 (54.4%) nurses, and 5 (4.8%) emergency medical technicians. The mean accuracy was 0.89 (standard deviation, 0.76). Among examiner determinants, only subjects’ occupation and clinical experience showed significant association with outcome (P=0.03 and P=0.08, respectively). All environmental determinants showed significant association with the outcome (all P<0.001). Multivariate analysis showed that accuracy rate was significantly associated with occupation, camera position, and compression depth. Conclusions The accuracy rate of chest compression depth estimation was 0.89 and was significantly related with examiner’s occupation, camera view position, and compression depth.

  7. Simulating the 21 cm signal from reionization including non-linear ionizations and inhomogeneous recombinations

    NASA Astrophysics Data System (ADS)

    Hassan, Sultan; Davé, Romeel; Finlator, Kristian; Santos, Mario G.

    2016-04-01

    We explore the impact of incorporating physically motivated ionization and recombination rates on the history and topology of cosmic reionization and the resulting 21 cm power spectrum, by incorporating inputs from small-volume hydrodynamic simulations into our semi-numerical code, SIMFAST21, that evolves reionization on large scales. We employ radiative hydrodynamic simulations to parametrize the ionization rate Rion and recombination rate Rrec as functions of halo mass, overdensity and redshift. We find that Rion scales superlinearly with halo mass ({R_ion}∝ M_h^{1.41}), in contrast to previous assumptions. Implementing these scalings into SIMFAST21, we tune our one free parameter, the escape fraction fesc, to simultaneously reproduce recent observations of the Thomson optical depth, ionizing emissivity and volume-averaged neutral fraction by the end of reionization. This yields f_esc=4^{+7}_{-2} per cent averaged over our 0.375 h-1 Mpc cells, independent of halo mass or redshift, increasing to 6 per cent if we also constrain to match the observed z = 7 star formation rate function. Introducing superlinear Rion increases the duration of reionization and boosts small-scale 21 cm power by two to three times at intermediate phases of reionization, while inhomogeneous recombinations reduce ionized bubble sizes and suppress large-scale 21 cm power by two to three times. Gas clumping on sub-cell scales has a minimal effect on the 21 cm power. Superlinear Rion also significantly increases the median halo mass scale for ionizing photon output to ˜ 1010 M⊙, making the majority of reionizing sources more accessible to next-generation facilities. These results highlight the importance of accurately treating ionizing sources and recombinations for modelling reionization and its 21 cm power spectrum.

  8. New Development of the Online Integrated Climate-Chemistry model framwork (RegCM-CHEM4)

    NASA Astrophysics Data System (ADS)

    Zakey, A. S.; Shalaby, A. K.; Solmon, F.; Giorgi, F.; Tawfik, A. B.; Steiner, A. L.; Baklanov, A.

    2012-04-01

    The RegCM-CHEM4 is a new online integrated climate-chemistry model based on the regional climate model (RegCM4). The RegCM4 developed at the Abdus Salam International Centre for Theoretical Physics (ICTP), is a hydrostatic, sigma coordinate model. Tropospheric gas-phase chemistry is integrated into the climate model using the condensed version of the Carbon Bond Mechanism CBM-Z with lumped species that represent broad categories of organics based on carbon bond structure. The computationally rapid radical balance method RBM is coupled as a chemical solver to the gas-phase mechanism. Photolysis rates are determined as a function of meteorological and chemical inputs and interpolated from an array of pre-determined values based on the Tropospheric Ultraviolet-Visible Model (TUV) with cloud cover corrections. Cloud optical depths and cloud altitudes from RegCM-CHEM4 are used in the photolysis calculations, thereby directly coupling the photolysis rates and chemical reactions to meteorological conditions at each model time step. In this study, we evaluate the model over Europe for two different time scales: (1) an event-based analysis of the ozone episode associated with the heat wave of August 2003 and (2) a climatological analysis of a six-year simulation (2000-2005). For the episode analysis, model simulations show a good agreement with the European Monitoring and Evaluation Program (EMEP) observations of hourly ozone over different regions in Europe and capture ozone concentrations during and after the summer 2003 heat wave event. Analysis of the full six years of simulation indicates that the coupled chemistry-climate model can reproduce the seasonal cycle of ozone, with an overestimation of ozone in the non-event years of 5-15 ppb depending on the geographic region. Overall, the ozone and ozone precursor evaluation shows the feasibility of using RegCM-CHEM4 for decadal-length simulations of chemistry-climate interactions.

  9. Growth and Physiological Responses to Water Depths in Carex schmidtii Meinsh

    PubMed Central

    Yan, Hong; Liu, Ruiquan; Liu, Zinan; Wang, Xue; Luo, Wenbo; Sheng, Lianxi

    2015-01-01

    A greenhouse experiment was performed to investigate growth and physiological responses to water depth in completely submerged condition of a wetland plant Carex schmidtii Meinsh., one of the dominant species in the Longwan Crater Lake wetlands (China). Growth and physiological responses of C. schmidtii were investigated by growing under control (non-submerged) and three submerged conditions (5 cm, 15 cm and 25 cm water level). Total biomass was highest in control, intermediate in 5 cm treatment and lowest in the other two submerged treatments. Water depth prominently affected the first-order lateral root to main root mass ratio. Alcohol dehydrogenase (ADH) activity decreased but malondialdehyde (MDA) content increased as water depth increased. The starch contents showed no differences among the various treatments at the end of the experiment. However, soluble sugar contents were highest in control, intermediate in 5 cm and 15 cm treatments and lowest in 25 cm treatment. Our data suggest that submergence depth affected some aspects of growth and physiology of C. schmidtii, which can reduce anoxia damage not only through maintaining the non-elongation strategy in shoot part but also by adjusting biomass allocation to different root orders rather than adjusting root-shoot biomass allocation. PMID:26009895

  10. Growth and Physiological Responses to Water Depths in Carex schmidtii Meinsh.

    PubMed

    Yan, Hong; Liu, Ruiquan; Liu, Zinan; Wang, Xue; Luo, Wenbo; Sheng, Lianxi

    2015-01-01

    A greenhouse experiment was performed to investigate growth and physiological responses to water depth in completely submerged condition of a wetland plant Carex schmidtii Meinsh., one of the dominant species in the Longwan Crater Lake wetlands (China). Growth and physiological responses of C. schmidtii were investigated by growing under control (non-submerged) and three submerged conditions (5 cm, 15 cm and 25 cm water level). Total biomass was highest in control, intermediate in 5 cm treatment and lowest in the other two submerged treatments. Water depth prominently affected the first-order lateral root to main root mass ratio. Alcohol dehydrogenase (ADH) activity decreased but malondialdehyde (MDA) content increased as water depth increased. The starch contents showed no differences among the various treatments at the end of the experiment. However, soluble sugar contents were highest in control, intermediate in 5 cm and 15 cm treatments and lowest in 25 cm treatment. Our data suggest that submergence depth affected some aspects of growth and physiology of C. schmidtii, which can reduce anoxia damage not only through maintaining the non-elongation strategy in shoot part but also by adjusting biomass allocation to different root orders rather than adjusting root-shoot biomass allocation.

  11. CM-2 Environmental / Modal Testing of Spacehab Racks

    NASA Technical Reports Server (NTRS)

    McNelis, Mark E.; Goodnight, Thomas W.; Farkas, Michael A.

    2001-01-01

    Combined environmental/modal vibration testing has been implemented at the NASA Glenn Research Center's Structural Dynamics Laboratory. The benefits of combined vibration testing are that it facilitates test article modal characterization and vibration qualification testing. The Combustion Module-2 (CM-2) is a space experiment that launches on Shuttle mission STS 107 in the SPACEHAB Research Double Module. The CM-2 flight hardware is integrated into a SPACEHAB single and double rack. CM-2 rack level combined vibration testing was recently completed on a shaker table to characterize the structure's modal response and verify the random vibration response. Control accelerometers and limit force gauges, located between the fixture and rack interface, were used to verify the input excitation. Results of the testing were used to verify the loads and environments for flight on the Shuttle.

  12. VLA observations of Uranus at 1. 3-20 cm

    SciTech Connect

    De Pater, I.; Gulkis, S.

    1988-08-01

    Observations of Uranus, obtained with resolution 0.5-1.2 arcsec at wavelengths 1.3, 2, 6, and 20 cm using the A and B configurations of the VLA in June-July 1982, October 1983, and February 1984, are reported. The disk-averaged brightness temperatures (DABTs) are determined by model fitting, and the results are presented in extensive graphs and contour maps and characterized in detail. Findings discussed include: (1) an overall spectrum which is relatively flat above 6 cm, (2) 1.3-6-cm brightness which is concentrated nearer to the pole than to the subsolar point, and (3) small changes in DABT from 1982 to 1983/1984 (consistent with an explanation based on a pole-equator temperature gradient). 16 references.

  13. Evidence for live Cm-247 in the early solar system

    NASA Technical Reports Server (NTRS)

    Tatsumoto, M.; Shimamura, T.

    1980-01-01

    Variations of the U-238/U-235 ratio in the Allende meteorite, ranging from -35% to +19% are interpreted as evidence of live Cm-247 in the early solar system. The amounts of these and other r-products in the solar system indicate values of (9000 + or - 3000) million years for the age of the Galaxy and approximately 8 million years for the time between the end of nucleosynthesis and the formation of meteoritic grains. Three possible explanations are presented for the different values of the latter time period which are indicated by the decay of products of Cm-247, Al-27, Pu-244, and I-129.

  14. WSRC Am/Cm Stabilization Program - Cylindrical Induction Melter Studies

    SciTech Connect

    Henderson, W.A.

    1999-02-17

    1.1.1 Kilogram quantities of Americium and Curium isotopes (Am/Cm) have been produced at the U.S. Department of Energy (DOE), Savannah River Site (SRS), Aiken, South Carolina. These highly radioactive isotopes have both government and commercial value and are currently stored as a nitric acid solution at the Savannah River Site. The material represents the largest source term in the F canyon at SRS. It is proposed that the Am/Cm material be vitrified to stabilize the material for long term, recoverable storage. This paper reviews the progress made during the process development phase of this program using the Cylindrical Induction Melter.

  15. Precise measurements of primordial power spectrum with 21 cm fluctuations

    SciTech Connect

    Kohri, Kazunori; Oyama, Yoshihiko; Sekiguchi, Toyokazu; Takahashi, Tomo E-mail: oyamayo@post.kek.jp E-mail: tomot@cc.saga-u.ac.jp

    2013-10-01

    We discuss the issue of how precisely we can measure the primordial power spectrum by using future observations of 21 cm fluctuations and cosmic microwave background (CMB). For this purpose, we investigate projected constraints on the quantities characterizing primordial power spectrum: the spectral index n{sub s}, its running α{sub s} and even its higher order running β{sub s}. We show that future 21 cm observations in combinations with CMB would accurately measure above mentioned observables of primordial power spectrum. We also discuss its implications to some explicit inflationary models.

  16. Evidence for live 247Cm in the early solar system

    USGS Publications Warehouse

    Tatsumoto, M.; Shimamura, T.

    1980-01-01

    Variations of the 238U/235U ratio in the Allende meteorite, ranging from -35% to + 19%, are interpreted as evidence of live 247Cm in the early Solar System. The amounts of these and other r-products in the Solar System indicate values of (9,000??3,000) Myr for the age of the Galaxy and ??? 8 Myr for the time between the end of nucleosynthesis and the formation of meteoritic grains. Three possible explanations are presented for the different values of the latter time period which are indicated by the decay products of 247Cm, 26Al, 244Pu and 129I. ?? 1980 Nature Publishing Group.

  17. Focus cues affect perceived depth

    PubMed Central

    Watt, Simon J.; Akeley, Kurt; Ernst, Marc O.; Banks, Martin S.

    2007-01-01

    Depth information from focus cues—accommodation and the gradient of retinal blur—is typically incorrect in three-dimensional (3-D) displays because the light comes from a planar display surface. If the visual system incorporates information from focus cues into its calculation of 3-D scene parameters, this could cause distortions in perceived depth even when the 2-D retinal images are geometrically correct. In Experiment 1 we measured the direct contribution of focus cues to perceived slant by varying independently the physical slant of the display surface and the slant of a simulated surface specified by binocular disparity (binocular viewing) or perspective/texture (monocular viewing). In the binocular condition, slant estimates were unaffected by display slant. In the monocular condition, display slant had a systematic effect on slant estimates. Estimates were consistent with a weighted average of slant from focus cues and slant from disparity/texture, where the cue weights are determined by the reliability of each cue. In Experiment 2, we examined whether focus cues also have an indirect effect on perceived slant via the distance estimate used in disparity scaling. We varied independently the simulated distance and the focal distance to a disparity-defined 3-D stimulus. Perceived slant was systematically affected by changes in focal distance. Accordingly, depth constancy (with respect to simulated distance) was significantly reduced when focal distance was held constant compared to when it varied appropriately with the simulated distance to the stimulus. The results of both experiments show that focus cues can contribute to estimates of 3-D scene parameters. Inappropriate focus cues in typical 3-D displays may therefore contribute to distortions in perceived space. PMID:16441189

  18. Lunar Far Side Regolith Depth

    NASA Astrophysics Data System (ADS)

    Bart, G. D.; Melosh, H. J.

    2005-08-01

    The lunar far side contains the South Pole Aitken Basin, which is the largest known impact basin in the solar system, and is enhanced in titanium and iron compared to the rest of the lunar highlands. Although we have known of this enigmatic basin since the 60's, most lunar photography and science covered the equatorial near side where the Apollo spacecraft landed. With NASA's renewed interest in the Moon, the South Pole Aitken Basin is a likely target for future exploration. The regolith depth is a crucial measurement for understanding the source of the surface material in the Basin. On the southern far side of the Moon (20 S, 180 W), near the north edge of the Basin, we determined the regolith depth by examining 11 flat-floored craters about 200 m in diameter. We measured the ratio of the diameter of the flat floor to the diameter of the crater, and used it to calculate the regolith thickness using the method of Quaide and Oberbeck (1968). We used Apollo 15 panoramic images --- still the highest resolution images available for this region of the Moon. We found the regolith depth at that location to be about 40 m. This value is significantly greater than values for the lunar near side: 3 m (Oceanus Procellarum), 16 m (Hipparchus), and 1-10 m at the Surveyor landing sites. The thicker value obtained for the far side regolith is consistent with the older age of the far side. It also suggests that samples returned from the far side may have originated from deeper beneath the surface than their near side counterparts.

  19. Snow Depth Mapping at a Basin-Wide Scale in the Western Arctic Using UAS Technology

    NASA Astrophysics Data System (ADS)

    de Jong, T.; Marsh, P.; Mann, P.; Walker, B.

    2015-12-01

    Assessing snow depths across the Arctic has proven to be extremely difficult due to the variability of snow depths at scales from metres to 100's of metres. New Unmanned Aerial Systems (UAS) technology provides the possibility to obtain centimeter level resolution imagery (~3cm), and to create Digital Surface Models (DSM) based on the Structure from Motion method. However, there is an ongoing need to quantify the accuracy of this method over different terrain and vegetation types across the Arctic. In this study, we used a small UAS equipped with a high resolution RGB camera to create DSMs over a 1 km2 watershed in the western Canadian Arctic during snow (end of winter) and snow-free periods. To improve the image georeferencing, 15 Ground Control Points were marked across the watershed and incorporated into the DSM processing. The summer DSM was subtracted from the snowcovered DSM to deliver snow depth measurements across the entire watershed. These snow depth measurements were validated by over 2000 snow depth measurements. This technique has the potential to improve larger scale snow depth mapping across watersheds by providing snow depth measurements at a ~3 cm . The ability of mapping both shallow snow (less than 75cm) covering much of the basin and snow patches (up to 5 m in depth) that cover less than 10% of the basin, but contain a significant portion of total basin snowcover, is important for both water resource applications, as well as for testing snow models.

  20. The Complexity and Challenges of the ICD-9-CM to ICD-10-CM Transition in Emergency Departments

    PubMed Central

    Krive, Jacob; Patel, Mahatkumar; Gehm, Lisa; Mackey, Mark; Kulstad, Erik; Li, Jianrong ‘John’; Lussier, Yves A.; Boyd, Andrew D.

    2015-01-01

    Beginning October 2015, the Center for Medicare and Medicaid Services (CMS) will require medical providers to utilize the vastly expanded ICD-10-CM system. Despite wide availability of information and mapping tools for the next generation of the ICD classification system, some of the challenges associated with transition from ICD-9-CM to ICD-10-CM are not well understood. To quantify the challenges faced by emergency physicians, we analyzed a subset of a 2010 Illinois Medicaid database of emergency department ICD-9-CM codes, seeking to determine the accuracy of existing mapping tools in order to better prepare emergency physicians for the change to the expanded ICD-10-CM system. We found that 27% of 1,830 codes represented convoluted multidirectional mappings. We then analyzed the convoluted transitions and found 8% of total visit encounters (23% of the convoluted transitions) were clinically incorrect. The ambiguity and inaccuracy of these mappings may impact the work flow associated with the translation process and affect the potential mapping between ICD codes and CPT (Current Procedural Codes) codes, which determine physician reimbursement. PMID:25863652

  1. Root tip morphology, anatomy, chemistry and potential hydraulic conductivity vary with soil depth in three temperate hardwood species.

    PubMed

    Wang, Yan; Dong, Xueyun; Wang, Hongfeng; Wang, Zhengquan; Gu, Jiacun

    2016-01-01

    Root traits in morphology, chemistry and anatomy are important to root physiological functions, but the differences between shallow and deep roots have rarely been studied in woody plants. Here, we selected three temperate hardwood species, Juglans mandshurica Maxim., Fraxinus mandschurica Rupr. and Phellodendron amurense Rupr., in plantations in northeastern China and measured morphological, anatomical and chemical traits of root tips (i.e., the first-order roots) at surface (0-10cm) and subsurface (20-30 cm) soil layers. The objectives of this study were to identify how those traits changed with soil depth and to reveal potential functional differences. The results showed that root diameters in deep root tips were greater in J. mandshurica and F. mandschurica, but smaller in P. amurense. However, root stele diameter and the ratio of stele to root diameter in the subsurface layer were consistently greater in all three species, which may enhance their abilities to penetrate into soil. All deep roots exhibited lower tissue nitrogen concentration and respiration rate, which were possibly caused by lower nutrient availability in the subsurface soil layer. Significant differences between shallow and deep roots were observed in xylem structure, with deep roots having thicker stele, wider maximum conduit and greater number of conduits per stele. Compared with shallow roots, the theoretical hydraulic conductivities in deep roots were enhanced by 133% (J. mandshurica), 78% (F. mandschurica) and 217% (P. amurense), respectively, indicating higher efficiency of transportation. Our results suggest that trees' root tip anatomical structure and physiological activity vary substantially with soil environment.

  2. Static stereo vision depth distortions in teleoperation

    NASA Technical Reports Server (NTRS)

    Diner, D. B.; Von Sydow, M.

    1988-01-01

    A major problem in high-precision teleoperation is the high-resolution presentation of depth information. Stereo television has so far proved to be only a partial solution, due to an inherent trade-off among depth resolution, depth distortion and the alignment of the stereo image pair. Converged cameras can guarantee image alignment but suffer significant depth distortion when configured for high depth resolution. Moving the stereo camera rig to scan the work space further distorts depth. The 'dynamic' (camera-motion induced) depth distortion problem was solved by Diner and Von Sydow (1987), who have quantified the 'static' (camera-configuration induced) depth distortion. In this paper, a stereo image presentation technique which yields aligned images, high depth resolution and low depth distortion is demonstrated, thus solving the trade-off problem.

  3. A cm scale electret-based electrostatic wind turbine for low-speed energy harvesting applications

    NASA Astrophysics Data System (ADS)

    Perez, M.; Boisseau, S.; Gasnier, P.; Willemin, J.; Geisler, M.; Reboud, J. L.

    2016-04-01

    This paper presents a small-scale airflow energy harvester built on an axial turbine architecture and exploiting an electret-based electrostatic converter. When the airflow velocity is high enough, the windmill starts rotating and creates a periodic relative motion between a stator and a rotor which induces variations of capacitance. These ones are directly converted into electricity thanks to the use of Teflon electrets charged at -1400 V which polarize the variable capacitors. We focus our study on a 4-blade axial turbine with a diameter of D = 40 mm, a depth of W = 10 mm, for a total volume of 12.6 cm3. This windmill has been tested with various blade angles and different types of electrostatic converters and output powers up to 90 μW at 1.5 m s-1 (7.5 μW cm-3) and 1.8 mW at 10 m s-1 (111 μW cm-3) have been obtained so far. The coefficient of power reaches C p = 5.8% and among the small-scale airflow energy harvesters previously reported, this one has the lowest cut-in speed (1.5 m s-1).

  4. Search for Cm-248 in the early solar system

    NASA Technical Reports Server (NTRS)

    Lavielle, B.; Marti, K.; Pellas, P.; Perron, C.

    1992-01-01

    Possible evidence for the presence of Cm-248 in the early solar system was reported from fission gas studies (Rao and Gopalan, 1973) and recently from studies of very high nuclear track densities (not less than 5 x 10 exp 8/sq cm) in the merrillite of the H4 chondrite Forest Vale (F.V.) (Pellas et al., 1987). We report here an analysis of the isotopic abundances of xenon in F.V. phosphates and results of track studies in phosphate/pyroxene contacts. The fission xenon isotopic signature clearly identifies Pu-244 as the extinct progenitor. We calculate an upper limit Cm-248/Pu-244 to be less than 0.0015 at the beginning of Xe retention in F.V. phosphates. This corresponds to an upper limit of the ratio Cm-248/U-235 of not greater than 5 x 10 exp -5 further constraining the evidence for any late addition of freshly synthesized actinide elements just prior to solar system formation. The fission track density observed after annealing the phosphates at 290C (1 hr, which essentially erases spallation recoil tracks) is also in agreement with the Pu-244 abundance inferred from fission Xe. The spallation recoil tracks produced during the 76 Ma cosmic-ray exposure account for the very high track density in merrillites.

  5. Retrofit and acceptance test of 30-cm ion thrusters

    NASA Technical Reports Server (NTRS)

    Poeschel, R. L.

    1981-01-01

    Six 30 cm mercury thrusters were modified to the J-series design and evaluated using standardized test procedures. The thruster performance meets the design objectives (lifetime objective requires verification), and documentation (drawings, etc.) for the design is completed and upgraded. The retrofit modifications are described and the test data for the modifications are presented and discussed.

  6. Preparing for ICD-10-CM in physician practices.

    PubMed

    Kuehn, Lynn

    2009-08-01

    What will change under CD-10-CM, and what must be done to prepare? This is the year for physician practices to get their ducks in a row: become informed, assess their IT and training needs, and make a plan that leads to the October 1, 2013, deadline.

  7. Calorimetric determination of kQ factors for NE 2561 and NE 2571 ionization chambers in 5 cm × 5 cm and 10 cm × 10 cm radiotherapy beams of 8 MV and 16 MV photons

    NASA Astrophysics Data System (ADS)

    Krauss, Achim; Kapsch, Ralf-Peter

    2007-10-01

    The relative uncertainty of the ionometric determination of the absorbed dose to water, Dw, in the reference dosimetry of high-energy photon beams is in the order of 1.5% and is dominated by the uncertainty of the calculated chamber- and energy-dependent correction factors kQ. In the present investigation, kQ values were determined experimentally in 5 cm × 5 cm and 10 cm × 10 cm radiotherapy beams of 8 MV and 16 MV bremsstrahlung by means of a water calorimeter operated at 4 °C. Ionization chambers of the types NE 2561 and NE 2571 were calibrated directly in the water phantom of the calorimeter. The measurements were carried out at the linear accelerator of the Physikalisch-Technische Bundesanstalt. It is shown that the kQ factor of a single ionization chamber can be measured with a standard uncertainty of less than 0.3%. No significant variations of kQ were found for the different lateral sizes of the radiation fields used in this investigation.

  8. The 21 cm signature of a cosmic string loop

    SciTech Connect

    Pagano, Michael; Brandenberger, Robert E-mail: rhb@physics.mcgill.ca

    2012-05-01

    Cosmic string loops lead to nonlinear baryon overdensities at early times, even before the time which in the standard LCDM model corresponds to the time of reionization. These overdense structures lead to signals in 21 cm redshift surveys at large redshifts. In this paper, we calculate the amplitude and shape of the string loop-induced 21 cm brightness temperature. We find that a string loop leads to a roughly elliptical region in redshift space with extra 21 cm emission. The excess brightness temperature for strings with a tension close to the current upper bound can be as high as 1deg K for string loops generated at early cosmological times (times comparable to the time of equal matter and radiation) and observed at a redshift of z+1 = 30. The angular extent of these predicted 'bright spots' is x{sup '}. These signals should be detectable in upcoming high redshift 21 cm surveys. We also discuss the application of our results to global monopoles and primordial black holes.

  9. Adaptation of California Measure of Mental Motivation-CM3

    ERIC Educational Resources Information Center

    Özdemir, Hasan Fehmi; Demirtasli, Nükhet Çikrikçi

    2015-01-01

    Education without doubt, plays a vital role for individuals to gain the essential personal traits of the 21st century, also known as "knowledge age". One of the most important skills among these fundamental qualities which the individuals should be equipped with is critical thinking. California Measure of Mental Motivation-CM3 was…

  10. Shallow depth subsurface imaging with microwave holography

    NASA Astrophysics Data System (ADS)

    Zhuravlev, Andrei; Ivashov, Sergey; Razevig, Vladimir; Vasiliev, Igor; Bechtel, Timothy

    2014-05-01

    In this paper, microwave holography is considered as a tool to obtain high resolution images of shallowly buried objects. Signal acquisition is performed at multiple frequencies on a grid using a two-dimensional mechanical scanner moving a single transceiver over an area of interest in close proximity to the surface. The described FFT-based reconstruction technique is used to obtain a stack of plan view images each using only one selected frequency from the operating waveband of the radar. The extent of a synthetically-formed aperture and the signal wavelength define the plan view resolution, which at sounding frequencies near 7 GHz amounts to 2 cm. The system has a short depth of focus which allows easy selection of proper focusing plane. The small distance from the buried objects to the antenna does not prevent recording of clean images due to multiple reflections (as happens with impulse radars). The description of the system hardware and signal processing technique is illustrated using experiments conducted in dry sand. The microwave images of inert anti-personnel mines are demonstrated as examples. The images allow target discrimination based on the same visually-discernible small features that a human observer would employ. The demonstrated technology shows promise for modification to meet the specific practical needs required for humanitarian demining or in multi-sensor survey systems.

  11. Characterization of nano-depth junctions in silicon by using Photo-Carrier Radiometry (PCR)

    NASA Astrophysics Data System (ADS)

    Garcia, J. A.; Guo, X.; Mandelis, A.; Shaughnessy, D.; Nicolaides, L.; Salnik, A.

    2008-01-01

    Non-contact, non-intrusive Photo-Carrier Radiometry (PCR) was used for monitoring nano-depth junctions in industrial-grade silicon wafers. The silicon wafers were implanted with arsenic to the dose of 5E1014 cm-2. The junction depth was in the 30 nm to 100 nm range. Quantitative results for PCR sensitivity to the junction depth and implantation energies are presented. This laser-based carrier-wave technique monitors harmonically photo-excited and recombining carriers and shows great potential advantages for the characterization of multiple semiconductor processes such as ion implantation, ultra shallow junction (USJ) depth determination and other Si wafer process steps.

  12. Tests of the Tully-Fisher relation. 1: Scatter in infrared magnitude versus 21 cm width

    NASA Technical Reports Server (NTRS)

    Bernstein, Gary M.; Guhathakurta, Puragra; Raychaudhury, Somak; Giovanelli, Riccardo; Haynes, Martha P.; Herter, Terry; Vogt, Nicole P.

    1994-01-01

    We examine the precision of the Tully-Fisher relation (TFR) using a sample of galaxies in the Coma region of the sky, and find that it is good to 5% or better in measuring relative distances. Total magnitudes and disk axis ratios are derived from H and I band surface photometry, and Arecibo 21 cm profiles define the rotation speeds of the galaxies. Using 25 galaxies for which the disk inclination and 21 cm width are well defined, we find an rms deviation of 0.10 mag from a linear TFR with dI/d(log W(sub c)) = -5.6. Each galaxy is assumed to be at a distance proportional to its redshift, and an extinction correction of 1.4(1-b/a) mag is applied to the total I magnitude. The measured scatter is less than 0.15 mag using milder extinction laws from the literature. The I band TFR scatter is consistent with measurement error, and the 95% CL limits on the intrinsic scatter are 0-0.10 mag. The rms scatter using H band magnitudes is 0.20 mag (N = 17). The low width galaxies have scatter in H significantly in excess of known measurement error, but the higher width half of the galaxies have scatter consistent with measurement error. The H band TFR slope may be as steep as the I band slope. As the first applications of this tight correlation, we note the following: (1) the data for the particular spirals commonly used to define the TFR distance to the Coma cluster are inconsistent with being at a common distance and are in fact in free Hubble expansion, with an upper limit of 300 km/s on the rms peculiar line-of-sight velocity of these gas-rich spirals; and (2) the gravitational potential in the disks of these galaxies has typical ellipticity less than 5%. The published data for three nearby spiral galaxies with Cepheid distance determinations are inconsistent with our Coma TFR, suggesting that these local calibrators are either ill-measured or peculiar relative to the Coma Supercluster spirals, or that the TFR has a varying form in different locales.

  13. Maribo—A new CM fall from Denmark

    NASA Astrophysics Data System (ADS)

    Haack, Henning; Grau, Thomas; Bischoff, Addi; Horstmann, Marian; Wasson, John; Sørensen, Anton; Laubenstein, Matthias; Ott, Ulrich; Palme, Herbert; Gellissen, Marko; Greenwood, Richard C.; Pearson, Victoria K.; Franchi, Ian A.; Gabelica, Zelimir; Schmitt-Kopplin, Philippe

    2012-01-01

    Maribo is a new Danish CM chondrite, which fell on January 17, 2009, at 19:08:28 CET. The fall was observed by many eye witnesses and recorded by a surveillance camera, an all sky camera, a few seismic stations, and by meteor radar observatories in Germany. A single fragment of Maribo with a dry weight of 25.8 g was found on March 4, 2009. The coarse-grained components in Maribo include chondrules, fine-grained olivine aggregates, large isolated lithic clasts, metals, and mineral fragments (often olivine), and rare Ca,Al-rich inclusions. The components are typically rimmed by fine-grained dust mantles. The matrix includes abundant dust rimmed fragments of tochilinite with a layered, fishbone-like texture, tochilinite-cronstedtite intergrowths, sulfides, metals, and carbonates often intergrown with tochilinite. The oxygen isotopic composition: (δ17O = -1.27‰; δ18O = 4.96‰; Δ17O = -3.85‰) plots at the edge of the CM field, close to the CCAM line. The very low Δ17O and the presence of unaltered components suggest that Maribo is among the least altered CM chondrites. The bulk chemistry of Maribo is typical of CM chondrites. Trapped noble gases are similar in abundance and isotopic composition to other CM chondrites, stepwise heating data indicating the presence of gas components hosted by presolar diamond and silicon carbide. The organics in Maribo include components also seen in Murchison as well as nitrogen-rich components unique to Maribo.

  14. High e+/e- Ratio Dense Pair Creation with 1021W.cm-2 Laser Irradiating Solid Targets

    NASA Astrophysics Data System (ADS)

    Liang, E.; Clarke, T.; Henderson, A.; Fu, W.; Lo, W.; Taylor, D.; Chaguine, P.; Zhou, S.; Hua, Y.; Cen, X.; Wang, X.; Kao, J.; Hasson, H.; Dyer, G.; Serratto, K.; Riley, N.; Donovan, M.; Ditmire, T.

    2015-09-01

    We report results of new pair creation experiments using ~100 Joule pulses of the Texas Petawatt Laser to irradiate solid gold and platinum targets, with intensities up to ~1.9 × 1021 W.cm-2 and pulse durations as short as ~130 fs. Positron to electron (e+/e-) ratios >15% were observed for many thick disk and rod targets, with the highest e+/e- ratio reaching ~50% for a Pt rod. The inferred pair yield was ~ few ×1010 with emerging pair density reaching ~1015/cm3 so that the pair skin depth becomes < pair jet transverse size. These results represent major milestones towards the goal of creating a significant quantity of dense pair-dominated plasmas with e+/e- approaching 100% and pair skin depth ≪ pair plasma size, which will have wide-ranging applications to astrophysics and fundamental physics.

  15. The Paris meteorite, the least altered CM chondrite so far

    NASA Astrophysics Data System (ADS)

    Hewins, Roger H.; Bourot-Denise, Michèle; Zanda, Brigitte; Leroux, Hugues; Barrat, Jean-Alix; Humayun, Munir; Göpel, Christa; Greenwood, Richard C.; Franchi, Ian A.; Pont, Sylvain; Lorand, Jean-Pierre; Cournède, Cécile; Gattacceca, Jérôme; Rochette, Pierre; Kuga, Maïa; Marrocchi, Yves; Marty, Bernard

    2014-01-01

    The Paris chondrite provides an excellent opportunity to study CM chondrules and refractory inclusions in a more pristine state than currently possible from other CMs, and to investigate the earliest stages of aqueous alteration captured within a single CM bulk composition. It was found in the effects of a former colonial mining engineer and may have been an observed fall. The texture, mineralogy, petrography, magnetic properties and chemical and isotopic compositions are consistent with classification as a CM2 chondrite. There are ∼45 vol.% high-temperature components mainly Type I chondrules (with olivine mostly Fa0-2, mean Fa0.9) with granular textures because of low mesostasis abundances. Type II chondrules contain olivine Fa7 to Fa76. These are dominantly of Type IIA, but there are IIAB and IIB chondrules, II(A)B chondrules with minor highly ferroan olivine, and IIA(C) with augite as the only pyroxene. The refractory inclusions in Paris are amoeboid olivine aggregates (AOAs) and fine-grained spinel-rich Ca-Al-rich inclusions (CAIs). The CAI phases formed in the sequence hibonite, perovskite, grossite, spinel, gehlenite, anorthite, diopside/fassaite and forsterite. The most refractory phases are embedded in spinel, which also occurs as massive nodules. Refractory metal nuggets are found in many CAI and refractory platinum group element abundances (PGE) decrease following the observed condensation sequences of their host phases. Mn-Cr isotope measurements of mineral separates from Paris define a regression line with a slope of 53Mn/55Mn = (5.76 ± 0.76) × 106. If we interpret Cr isotopic systematics as dating Paris components, particularly the chondrules, the age is 4566.44 ± 0.66 Myr, which is close to the age of CAI and puts new constraints on the early evolution of the solar system. Eleven individual Paris samples define an O isotope mixing line that passes through CM2 and CO3 falls and indicates that Paris is a very fresh sample, with variation explained

  16. The 12 micron band of ethane: A spectral catalog from 765 cm(-1) to 900 cm(-1)

    NASA Technical Reports Server (NTRS)

    Atakan, A. K.; Blass, W. E.; Brault, J. W.; Daunt, S. J.; Halsey, G. W.; Jennings, D. E.; Reuter, D. C.; Susskind, J.

    1983-01-01

    The high resolution laboratory absorption spectrum of the 12 micro band of ethane gas is studied. The data were obtained using the McMath Solar Telescope 1 meter Fourier Transform interferometer at Kitt Peak National Observatory and tunable diode laser spectrometers at the University of Tennessee and NASA/Goddard Space Flight Center. Over 200 individual vibration rotation transitions were analyzed taking into account many higher order effects including torsional splitting. Line positions were reproduced to better than 0.001/cm. Both ground and upper state molecular constants were determined in the analysis. The experimental details, the analysis procedures and the results are addressed. A list of ethane transitions occurring near (14)CO2 laser lines needed for heterodyne searches for C2H6 in extraterrestrial sources is also included. A spectral catalog of the ethane nu sub g fundamental from 765/cm to 900/cm is provided. A high dispersion (1/cm 12 in.) plot of both the Kitt Peak interferometric data and a simulated spectrum with Doppler limited resolution, a table of over 8500 calculated transitions listed quantum number assignments, frequencies and intensities are provided.

  17. Foundation Depth for Bridge Piers

    NASA Astrophysics Data System (ADS)

    Veerappadevaru, G.; Gangadharaiah, T.; Jagadeesh, T. R.

    2013-09-01

    The safety of bridge piers built in rivers having the bed is one of the prime aspects in the study of scouring process around bridge piers. The stability of bridge piers depends on the depth of foundation provided below maximum scour level. The stability analysis of bridge piers is carried based on moment of forces acting on the caisson pier when the pier slides and tilts slightly in downstream from its position. The experiments are conducted for three pier shapes on two sediment beds and for different flow conditions. The curves indicating the stability limits are compared with Lacey's recommendations which are used in present day practice in India. The analysis presented here indicates that the Lacey's recommendation for railway bridges is safe and for some cases of the road bridges depends on grip length, angle of tilt and weight of caisson.

  18. Aeration equipment for small depths

    NASA Astrophysics Data System (ADS)

    Sluše, Jan; Pochylý, František

    2015-05-01

    Deficit of air in water causes complications with cyanobacteria mainly in the summer months. Cyanobacteria is a bacteria that produces poison called cyanotoxin. When the concentration of cyanobacteria increases, the phenomena "algal bloom" appears, which is very toxic and may kill all the organisms. This article describes new equipment for aeration of water in dams, ponds and reservoirs with small depth. This equipment is mobile and it is able to work without any human factor because its control is provided by a GPS module. The main part of this equipment consists of a floating pump which pumps water from the surface. Another important part of this equipment is an aerator where water and air are blended. Final aeration process runs in the nozzles which provide movement of all this equipment and aeration of the water. Simulations of the flow are solved by multiphase flow with diffusion in open source program called OpenFOAM. Results will be verified by an experiment.

  19. Development of a 60 cm Magnetic Suspension System

    NASA Astrophysics Data System (ADS)

    Sawada, Hideo; Kunimasu, Tetsuya

    A 60cm Magnetic Suspension Balance System (MSBS), which has been developed in the National Aerospace Laboratory of Japan (NAL), is described in detail. Magnetic field in the MSBS is evaluated analytically and is compared with measured one. Available magnet kinds for the MSBS are selected analytically. The optimum ratio of diameter to length of cylindrical magnet for the MSBS is also evaluated. A model position sensing and the control systems are described with calibration test results. A model holding system is also shown, which is necessary for worker’s safety at suspending a large and massive model. The control system is presented and the measured model position during suspension is examined. The balance accuracy is examined and its error of drag force can be improved by restricting the calibration test to an expected drag range. Flow of the 60cm low-speed wind tunnel equipped with the MSBS is examined to be available for wind tunnel tests.

  20. Precision measurement of cosmic magnification from 21 cm emitting galaxies

    SciTech Connect

    Zhang, Pengjie; Pen, Ue-Li; /Canadian Inst. Theor. Astrophys.

    2005-04-01

    We show how precision lensing measurements can be obtained through the lensing magnification effect in high redshift 21cm emission from galaxies. Normally, cosmic magnification measurements have been seriously complicated by galaxy clustering. With precise redshifts obtained from 21cm emission line wavelength, one can correlate galaxies at different source planes, or exclude close pairs to eliminate such contaminations. We provide forecasts for future surveys, specifically the SKA and CLAR. SKA can achieve percent precision on the dark matter power spectrum and the galaxy dark matter cross correlation power spectrum, while CLAR can measure an accurate cross correlation power spectrum. The neutral hydrogen fraction was most likely significantly higher at high redshifts, which improves the number of observed galaxies significantly, such that also CLAR can measure the dark matter lensing power spectrum. SKA can also allow precise measurement of lensing bispectrum.

  1. Lensing of 21-cm fluctuations by primordial gravitational waves.

    PubMed

    Book, Laura; Kamionkowski, Marc; Schmidt, Fabian

    2012-05-25

    Weak-gravitational-lensing distortions to the intensity pattern of 21-cm radiation from the dark ages can be decomposed geometrically into curl and curl-free components. Lensing by primordial gravitational waves induces a curl component, while the contribution from lensing by density fluctuations is strongly suppressed. Angular fluctuations in the 21-cm background extend to very small angular scales, and measurements at different frequencies probe different shells in redshift space. There is thus a huge trove of information with which to reconstruct the curl component of the lensing field, allowing tensor-to-scalar ratios conceivably as small as r~10(-9)-far smaller than those currently accessible-to be probed. PMID:23003237

  2. POLYSHIFT Communications Software for the Connection Machine System CM-200

    DOE PAGES

    George, William; Brickner, Ralph G.; Johnsson, S. Lennart

    1994-01-01

    We describe the use and implementation of a polyshift function PSHIFT for circular shifts and end-offs shifts. Polyshift is useful in many scientific codes using regular grids, such as finite difference codes in several dimensions, and multigrid codes, molecular dynamics computations, and in lattice gauge physics computations, such as quantum chromodynamics (QCD) calculations. Our implementation of the PSHIFT function on the Connection Machine systems CM-2 and CM-200 offers a speedup of up to a factor of 3–4 compared with CSHIFT when the local data motion within a node is small. The PSHIFT routine is included in the Connection Machine Scientificmore » Software Library (CMSSL).« less

  3. 21 cm cosmology in the 21st century.

    PubMed

    Pritchard, Jonathan R; Loeb, Abraham

    2012-08-01

    Imaging the Universe during the first hundreds of millions of years remains one of the exciting challenges facing modern cosmology. Observations of the redshifted 21 cm line of atomic hydrogen offer the potential of opening a new window into this epoch. This will transform our understanding of the formation of the first stars and galaxies and of the thermal history of the Universe. A new generation of radio telescopes is being constructed for this purpose with the first results starting to trickle in. In this review, we detail the physics that governs the 21 cm signal and describe what might be learnt from upcoming observations. We also generalize our discussion to intensity mapping of other atomic and molecular lines.

  4. 21 cm cosmology in the 21st century.

    PubMed

    Pritchard, Jonathan R; Loeb, Abraham

    2012-08-01

    Imaging the Universe during the first hundreds of millions of years remains one of the exciting challenges facing modern cosmology. Observations of the redshifted 21 cm line of atomic hydrogen offer the potential of opening a new window into this epoch. This will transform our understanding of the formation of the first stars and galaxies and of the thermal history of the Universe. A new generation of radio telescopes is being constructed for this purpose with the first results starting to trickle in. In this review, we detail the physics that governs the 21 cm signal and describe what might be learnt from upcoming observations. We also generalize our discussion to intensity mapping of other atomic and molecular lines. PMID:22828208

  5. SU-E-J-197: Investigation of Microsoft Kinect 2.0 Depth Resolution for Patient Motion Tracking

    SciTech Connect

    Silverstein, E; Snyder, M

    2015-06-15

    Purpose: Investigate the use of the Kinect 2.0 for patient motion tracking during radiotherapy by studying spatial and depth resolution capabilities. Methods: Using code written in C#, depth map data was abstracted from the Kinect to create an initial depth map template indicative of the initial position of an object to be compared to the depth map of the object over time. To test this process, simple setup was created in which two objects were imaged: a 40 cm × 40 cm board covered in non reflective material and a 15 cm × 26 cm textbook with a slightly reflective, glossy cover. Each object, imaged and measured separately, was placed on a movable platform with object to camera distance measured. The object was then moved a specified amount to ascertain whether the Kinect’s depth camera would visualize the difference in position of the object. Results: Initial investigations have shown the Kinect depth resolution is dependent on the object to camera distance. Measurements indicate that movements as small as 1 mm can be visualized for objects as close as 50 cm away. This depth resolution decreases linearly with object to camera distance. At 4 m, the depth resolution had decreased to observe a minimum movement of 1 cm. Conclusion: The improved resolution and advanced hardware of the Kinect 2.0 allows for increase of depth resolution over the Kinect 1.0. Although obvious that the depth resolution should decrease with increasing distance from an object given the decrease in number of pixels representing said object, the depth resolution at large distances indicates its usefulness in a clinical setting.

  6. OH 18 cm TRANSITION AS A THERMOMETER FOR MOLECULAR CLOUDS

    SciTech Connect

    Ebisawa, Yuji; Inokuma, Hiroshi; Yamamoto, Satoshi; Sakai, Nami; Menten, Karl M.; Maezawa, Hiroyuki

    2015-12-10

    We have observed the four hyperfine components of the 18 cm OH transition toward the translucent cloud eastward of Heiles Cloud 2 (HCL2E), the cold dark cloud L134N, and the photodissociation region of the ρ-Ophiuchi molecular cloud with the Effelsberg 100 m telescope. We have found intensity anomalies among the hyperfine components in all three regions. In particular, an absorption feature of the 1612 MHz satellite line against the cosmic microwave background has been detected toward HCL2E and two positions of the ρ-Ophiuchi molecular cloud. On the basis of statistical equilibrium calculations, we find that the hyperfine anomalies originate from the non-LTE population of the hyperfine levels, and can be used to determine the kinetic temperature of the gas over a wide range of H{sub 2} densities (10{sup 2}–10{sup 7} cm{sup −3}). Toward the center of HCL2E, the gas kinetic temperature is determined to be 53 ± 1 K, and it increases toward the cloud peripheries (∼60 K). The ortho-to-para ratio of H{sub 2} is determined to be 3.5 ± 0.9 from the averaged spectrum for the eight positions. In L134N, a similar increase of the temperature is also seen toward the periphery. In the ρ-Ophiuchi molecular cloud, the gas kinetic temperature decreases as a function of the distance from the exciting star HD 147889. These results demonstrate a new aspect of the OH 18 cm line that can be used as a good thermometer of molecular cloud envelopes. The OH 18 cm line can be used to trace a new class of warm molecular gas surrounding a molecular cloud, which is not well traced by the emission of CO and its isotopologues.

  7. OH 18 cm Transition as a Thermometer for Molecular Clouds

    NASA Astrophysics Data System (ADS)

    Ebisawa, Yuji; Inokuma, Hiroshi; Sakai, Nami; Menten, Karl M.; Maezawa, Hiroyuki; Yamamoto, Satoshi

    2015-12-01

    We have observed the four hyperfine components of the 18 cm OH transition toward the translucent cloud eastward of Heiles Cloud 2 (HCL2E), the cold dark cloud L134N, and the photodissociation region of the ρ-Ophiuchi molecular cloud with the Effelsberg 100 m telescope. We have found intensity anomalies among the hyperfine components in all three regions. In particular, an absorption feature of the 1612 MHz satellite line against the cosmic microwave background has been detected toward HCL2E and two positions of the ρ-Ophiuchi molecular cloud. On the basis of statistical equilibrium calculations, we find that the hyperfine anomalies originate from the non-LTE population of the hyperfine levels, and can be used to determine the kinetic temperature of the gas over a wide range of H2 densities (102-107 cm-3). Toward the center of HCL2E, the gas kinetic temperature is determined to be 53 ± 1 K, and it increases toward the cloud peripheries (˜60 K). The ortho-to-para ratio of H2 is determined to be 3.5 ± 0.9 from the averaged spectrum for the eight positions. In L134N, a similar increase of the temperature is also seen toward the periphery. In the ρ-Ophiuchi molecular cloud, the gas kinetic temperature decreases as a function of the distance from the exciting star HD 147889. These results demonstrate a new aspect of the OH 18 cm line that can be used as a good thermometer of molecular cloud envelopes. The OH 18 cm line can be used to trace a new class of warm molecular gas surrounding a molecular cloud, which is not well traced by the emission of CO and its isotopologues.

  8. Control of a 30 cm diameter mercury bombardment thruster

    NASA Technical Reports Server (NTRS)

    Terdan, F. F.; Bechtel, R. T.

    1973-01-01

    Control logic functions were established for three automatic modes of operation of a 30-cm thruster using a power conditioner console with flight-like characteristics. The three modes provide: (1) automatic startup to reach thermal stability, (2) steady-state closed-loop control, and (3) the reliable recycling of the high voltages following an arc breakdown to reestablish normal operation. Power supply impedance characteristics necessary for stable operation and the effect of the magnetic baffle on the reliable recycling was studied.

  9. Semi-Lagrangian shallow water modeling on the CM-5

    SciTech Connect

    Nadiga, B.T.; Margolin, L.G.; Smolarkiewicz, P.K.

    1995-09-01

    We discuss the parallel implementation of a semi-Lagrangian shallow-water model on the massively parallel Connection Machine CM-5. The four important issues we address in this article are (i) two alternative formulations of the elliptic problem and their relative efficiencies, (ii) the performance of two successive orders of a generalized conjugate residual elliptic solver, (iii) the time spent in unstructured communication -- an unavoidable feature of semi-Lagrangian schemes, and (iv) the scalability of the algorithm.

  10. The future of primordial features with 21 cm tomography

    NASA Astrophysics Data System (ADS)

    Chen, Xingang; Meerburg, P. Daniel; Münchmeyer, Moritz

    2016-09-01

    Detecting a deviation from a featureless primordial power spectrum of fluctuations would give profound insight into the physics of the primordial Universe. Depending on their nature, primordial features can either provide direct evidence for the inflation scenario or pin down details of the inflation model. Thus far, using the cosmic microwave background (CMB) we have only been able to put stringent constraints on the amplitude of features, but no significant evidence has been found for such signals. Here we explore the limit of the experimental reach in constraining such features using 21 cm tomography at high redshift. A measurement of the 21 cm power spectrum from the Dark Ages is generally considered as the ideal experiment for early Universe physics, with potentially access to a large number of modes. We consider three different categories of theoretically motivated models: the sharp feature models, resonance models, and standard clock models. We study the improvements on bounds on features as a function of the total number of observed modes and identify parameter degeneracies. The detectability depends critically on the amplitude, frequency and scale-location of the features, as well as the angular and redshift resolution of the experiment. We quantify these effects by considering different fiducial models. Our forecast shows that a cosmic variance limited 21 cm experiment measuring fluctuations in the redshift range 30 <= z <= 100 with a 0.01-MHz bandwidth and sub-arcminute angular resolution could potentially improve bounds by several orders of magnitude for most features compared to current Planck bounds. At the same time, 21 cm tomography also opens up a unique window into features that are located on very small scales.

  11. The 21 cm signature of cosmic string wakes

    SciTech Connect

    Brandenberger, Robert H.; Danos, Rebecca J.; Hernández, Oscar F.; Holder, Gilbert P. E-mail: rjdanos@physics.mcgill.ca E-mail: holder@physics.mcgill.ca

    2010-12-01

    We discuss the signature of a cosmic string wake in 21cm redshift surveys. Since 21cm surveys probe higher redshifts than optical large-scale structure surveys, the signatures of cosmic strings are more manifest in 21cm maps than they are in optical galaxy surveys. We find that, provided the tension of the cosmic string exceeds a critical value (which depends on both the redshift when the string wake is created and the redshift of observation), a cosmic string wake will generate an emission signal with a brightness temperature which approaches a limiting value which at a redshift of z+1 = 30 is close to 400 mK in the limit of large string tension. The signal will have a specific signature in position space: the excess 21cm radiation will be confined to a wedge-shaped region whose tip corresponds to the position of the string, whose planar dimensions are set by the planar dimensions of the string wake, and whose thickness (in redshift direction) depends on the string tension. For wakes created at z{sub i}+1 = 10{sup 3}, then at a redshift of z+1 = 30 the critical value of the string tension μ is Gμ = 6 × 10{sup −7}, and it decreases linearly with redshift (for wakes created at the time of equal matter and radiation, the critical value is a factor of two lower at the same redshift). For smaller tensions, cosmic strings lead to an observable absorption signal with the same wedge geometry.

  12. A box corer 30 cm square and 4 m long

    NASA Astrophysics Data System (ADS)

    Foster Johnson, Richard

    1988-08-01

    To collect long, large-volume cores of diatomaceous sediment on the continental shelf off Namibia, we built a box corer that is 30 cm square and 4 m long. This paper describes the corer and the tools and procedures for sampling the covers. In terms of volume of sediment recovered in a single penetration, the corer may be among the largest ever used. The corer itself consists of a barrel with segments 20 cm long, a release mechanism at top and a thin fiberglass curtain at bottom. To support the large load of sediment without distortion, the curtain follows a semi-circular track, concave upward. During assembly and disassembly, the corer hangs vertically over the side, enabling it to operate from a relatively small ship. To sample the core, an extruding device pushes the sediment from each segment into boxes made of polyurethane foam. Ashore a specially designed jig helps slice these boxes into vertical slabs as thin as 1 cm. In the 6 days at sea that we had to test the corer and collect samples for the project, we took 9 cores, the longest of which was 3 m.

  13. Am/Cm Vitrification Process: Vitrification Material Balance Calculations

    SciTech Connect

    Smith, F.G.

    2000-08-15

    This report documents material balance calculations for the Americium/Curium vitrification process and describes the basis used to make the calculations. The material balance calculations reported here start with the solution produced by the Am/Cm pretreatment process as described in ``Material Balance Calculations for Am/Cm Pretreatment Process (U)'', SRT-AMC-99-0178 [1]. Following pretreatment, small batches of the product will be further treated with an additional oxalic acid precipitation and washing. The precipitate from each batch will then be charged to the Am/Cm melter with glass cullet and vitrified to produce the final product. The material balance calculations in this report are designed to provide projected compositions of the melter glass and off-gas streams. Except for decanted supernate collected from precipitation and precipitate washing, the flowsheet neglects side streams such as acid washes of empty tanks that would go directly to waste. Complete listings of the results of the material balance calculations are provided in the Appendices to this report.

  14. The wedge bias in reionization 21-cm power spectrum measurements

    NASA Astrophysics Data System (ADS)

    Jensen, Hannes; Majumdar, Suman; Mellema, Garrelt; Lidz, Adam; Iliev, Ilian T.; Dixon, Keri L.

    2016-02-01

    A proposed method for dealing with foreground emission in upcoming 21-cm observations from the epoch of reionization is to limit observations to an uncontaminated window in Fourier space. Foreground emission can be avoided in this way, since it is limited to a wedge-shaped region in k∥, k⊥ space. However, the power spectrum is anisotropic owing to redshift-space distortions from peculiar velocities. Consequently, the 21-cm power spectrum measured in the foreground avoidance window - which samples only a limited range of angles close to the line-of-sight direction - differs from the full redshift-space spherically averaged power spectrum which requires an average over all angles. In this paper, we calculate the magnitude of this `wedge bias' for the first time. We find that the bias amplifies the difference between the real-space and redshift-space power spectra. The bias is strongest at high redshifts, where measurements using foreground avoidance will overestimate the redshift-space power spectrum by around 100 per cent, possibly obscuring the distinctive rise and fall signature that is anticipated for the spherically averaged 21-cm power spectrum. In the later stages of reionization, the bias becomes negative, and smaller in magnitude (≲20 per cent).

  15. Distinct Distribution of Purines in CM and CR Carbonaceous Chondrites

    NASA Technical Reports Server (NTRS)

    Callahan, Michael P.; Stern, Jennifer C.; Glavin, Daniel P.; Smith, Karen E.; Martin, Mildred G.; Dworkin, Jason P.

    2010-01-01

    Carbonaceous meteorites contain a diverse suite of organic molecules and delivered pre biotic organic compounds, including purines and pyrimidines, to the early Earth (and other planetary bodies), seeding it with the ingredients likely required for the first genetic material. We have investigated the distribution of nucleobases in six different CM and CR type carbonaceous chondrites, including fivc Antarctic meteorites never before analyzed for nucleobases. We employed a traditional formic acid extraction protocol and a recently developed solid phase extraction method to isolate nucleobases. We analyzed these extracts by high performance liquid chromatography with UV absorbance detection and tandem mass spectrometry (HPLC-UV -MS/MS) targeting the five canonical RNAIDNA bases and hypoxanthine and xanthine. We detected parts-per-billion levels of nucleobases in both CM and CR meteorites. The relative abundances of the purines found in Antarctic CM and CR meteorites were clearly distinct from each other suggesting that these compounds are not terrestrial contaminants. One likely source of these purines is formation by HCN oligomerization (with other small molecules) during aqueous alteration inside the meteorite parent body. The detection of the purines adenine (A), guanine (0), hypoxanthine (HX), and xanthine (X) in carbonaceous meteorites indicates that these compounds should have been available on the early Earth prior to the origin of the first genetic material.

  16. BRIGHT SOURCE SUBTRACTION REQUIREMENTS FOR REDSHIFTED 21 cm MEASUREMENTS

    SciTech Connect

    Datta, A.; Bowman, J. D.; Carilli, C. L.

    2010-11-20

    The H I 21 cm transition line is expected to be an important probe into the cosmic dark ages and epoch of reionization. Foreground source removal is one of the principal challenges for the detection of this signal. This paper investigates the extragalactic point source contamination and how accurately bright sources ({approx}>1 Jy) must be removed in order to detect 21 cm emission with upcoming radio telescopes such as the Murchison Widefield Array. We consider the residual contamination in 21 cm maps and power spectra due to position errors in the sky model for bright sources, as well as frequency-independent calibration errors. We find that a source position accuracy of 0.1 arcsec will suffice for detection of the H I power spectrum. For calibration errors, 0.05% accuracy in antenna gain amplitude is required in order to detect the cosmic signal. Both sources of subtraction error produce residuals that are localized to small angular scales, k{sub perpendicular} {approx}> 0.05 Mpc{sup -1}, in the two-dimensional power spectrum.

  17. A quantile count model of water depth constraints on Cape Sable seaside sparrows

    USGS Publications Warehouse

    Cade, B.S.; Dong, Q.

    2008-01-01

    1. A quantile regression model for counts of breeding Cape Sable seaside sparrows Ammodramus maritimus mirabilis (L.) as a function of water depth and previous year abundance was developed based on extensive surveys, 1992-2005, in the Florida Everglades. The quantile count model extends linear quantile regression methods to discrete response variables, providing a flexible alternative to discrete parametric distributional models, e.g. Poisson, negative binomial and their zero-inflated counterparts. 2. Estimates from our multiplicative model demonstrated that negative effects of increasing water depth in breeding habitat on sparrow numbers were dependent on recent occupation history. Upper 10th percentiles of counts (one to three sparrows) decreased with increasing water depth from 0 to 30 cm when sites were not occupied in previous years. However, upper 40th percentiles of counts (one to six sparrows) decreased with increasing water depth for sites occupied in previous years. 3. Greatest decreases (-50% to -83%) in upper quantiles of sparrow counts occurred as water depths increased from 0 to 15 cm when previous year counts were 1, but a small proportion of sites (5-10%) held at least one sparrow even as water depths increased to 20 or 30 cm. 4. A zero-inflated Poisson regression model provided estimates of conditional means that also decreased with increasing water depth but rates of change were lower and decreased with increasing previous year counts compared to the quantile count model. Quantiles computed for the zero-inflated Poisson model enhanced interpretation of this model but had greater lack-of-fit for water depths > 0 cm and previous year counts 1, conditions where the negative effect of water depths were readily apparent and fitted better with the quantile count model.

  18. Effect of soil, sowing depth and sowing date on growth and survival of Pistacia atlantica seedlings.

    PubMed

    Gholami, Shayesteh; Hosseini, Seyed Mohsen; Sayad, Ehsan

    2007-01-15

    The effect of soil, sowing depth and sowing date on growth and survival of Pistacia atlantica seedlings was evaluated in nursery conditions. Pistacia atlantica is a deciduous tree species that belongs to the Anacardiaceae family. It is valuable in soil conservation and so suitable for plantation in dry lands. Regeneration of Pistacia atlantica in western part of Iran due to much destruction to its natural habitats has problems. Two levels of soil (Forest and nursery soil) and three levels of sowing date (9 and 29 January, 18 February) were used. In addition, seed were sown at three different depths (0, 4 and 8 cm) but no seedlings emerged when seeds were sown at 0 sowing depth. At the end of first growing season on September 2004 survival, height above the soil surface, collar diameter, shoot/root length ratio and shoot/root dry weight ratio were measured. Survival was significantly affected by sowing date and sowing depth but not by soil. Survival was greater at 4 cm than at 8 cm sowing depth and in 9 January and 29 January than in 18 February sowing dates. Collar diameter and height were significantly greater in nursery soil and 9 January and 29 January sowing date but were not different among sowing depths. Shoot/root ratio and shoot/root dry weight ratio were significantly lower in forest soil but not affected by sowing date. Shoot/root dry weight ratio was lower in 4 cm sowing depth while shoot/root ratio did not showed any difference among sowing depth. In general soil type, sowing date and sowing depth are factors that can be influence on physical and morphological traits of seedlings.

  19. The ecological response of Carex lasiocarpa community in the Riparian Wetlands to the environmental gradient of water depth in Sanjiang Plain, Northeast China.

    PubMed

    Luan, Zhaoqing; Wang, Zhongxin; Yan, Dandan; Liu, Guihua; Xu, Yingying

    2013-01-01

    The response of Carex lasiocarpa in riparian wetlands in Sanjiang Plain to the environmental gradient of water depth was analyzed by using the Gaussian Model based on the biomass and average height data, and the ecological water-depth amplitude of Carex lasiocarpa was derived. The results indicated that the optimum ecological water-depth amplitude of Carex lasiocarpa based on biomass was [13.45 cm, 29.78 cm], while the optimum ecological water-depth amplitude of Carex lasiocarpa based on average height was [2.31 cm, 40.11 cm]. The intersection of the ecological water-depth amplitudes based on biomass and height confirmed that the optimum ecological water-depth amplitude of Carex lasiocarpa was [13.45 cm, 29.78 cm] and the optimist growing water-depth of Carex lasiocarpa was 21.4 cm. The TWINSPAN, a polythetic and divisive classification tool, was used to classify the wetland ecological series into 6 associations. Result of TWINSPAN matrix classification reflected an obvious environmental gradient in these associations: water-depth gradient. The relation of biodiversity of Carex lasiocarpa community and water depth was determined by calculating the diversity index of each association.

  20. Tomicus piniperda (Coleoptera: Scolytidae) emergence in relation to burial depth of brood logs.

    PubMed

    Haack, R A; Petrice, T R; Poland, T M

    2000-04-01

    The pine shoot beetle, Tomicus piniperda (L.), is an exotic pest of pines, Pinus spp., that was first found in the United States in 1992. A federal quarantine currently regulates movement of pine Christmas trees and pine nursery stock from infested to uninfested counties. The current national Pine Shoot Beetle Compliance Management Program requires T. piniperda-infested brood material to be disposed of by burning, chipping, or burial. The burial option requires that the infested pine material be buried at a depth of at least 30 cm. We tested this requirement by burying logs with similar levels of infestation at 0, 15, 30, 45, 61 and 76 cm and then monitoring for T. piniperda emergence. Logs were buried at two times during larval development (early and late) and in two soil types (sandy loam and loam). Emergence patterns from the two soil types were similar. Overall, 1,747 T. piniperda adults were collected from the 24 exposed control logs, but only 34 adults from the 120 buried logs, including 24 adults from logs buried at 15 cm, eight adults from 30 cm, one adult from 45 cm, and one adult from 61 cm. In comparing mean emergence density from buried logs with that of exposed logs, 98.6% mortality occurred at 15 cm, 99.5% at 30 cm, and > 99.9% at > or = 45 cm. Mean date of T. piniperda emergence to the soil surface was affected by burial depth and burial date, but not soil type.

  1. 10 cm x 10 cm Single Gas Electron Multiplier (GEM) X-ray Fluorescence Detector for Dilute Elements

    NASA Astrophysics Data System (ADS)

    Shaban, E. H.; Siddons, D. P.; Seifu, D.

    2014-03-01

    We have built and tested a 10 cm × 10 cm single Gas Electron Multiplier (GEM) X-ray detector to probe dilute amounts of Fe in a prepared sample. The detector uses Argon/Carbon Dioxide (75/25) gas mixture flowing at a slow rate through a leak proof Plexi-glass enclosure held together by O-rings and screws. The Fluorescence X-ray emitted by the element under test is directed through a Mylar window into the drift region of the detector where abundant gas is flowing. The ionized electrons are separated, drifted into the high electric field of the GEM, and multiplied by impact ionization. The amplified negatively charged electrons are collected and further amplified by a Keithley amplifier to probe the absorption edge of the element under test using X-ray absorption spectroscopy technique. The results show that the GEM detector provided good results with less noise as compared with a Silicon drift detector (SDD).

  2. Visual Cues for Enhancing Depth Perception.

    ERIC Educational Resources Information Center

    O'Donnell, L. M.; Smith, A. J.

    1994-01-01

    This article describes the physiological mechanisms involved in three-dimensional depth perception and presents a variety of distance and depth cues and strategies for detecting and estimating curbs and steps for individuals with impaired vision. (Author/DB)

  3. Uterine caliper and depth gauge

    DOEpatents

    King, Loyd L.; Wheeler, Robert G.; Fish, Thomas M.

    1977-01-01

    A uterine caliper and sound consisting of an elongated body having outwardly biased resilient caliper wings and a spring-loaded slidable cervical stop. A slide on the body is operatively connected to the wings by a monofilament and operates with respect to a first scale on the body as a width indicator. A rod extending longitudinally on the body is connected to the cervical stop and cooperates with a second scale on the body as a depth indicator. The instrument can be positioned to measure the distance from the outer cervical ostium to the fundus, as read on said second scale. The wings may be allowed to open by moving the slide, and when the wings engage the utero-tubal junctions, the width may be read on said first scale. By adjustment of the caliper wings the instrument may be retracted until the resistance of the inner ostium of the cervix is felt, enabling the length of the cervical canal to be read directly by the position of the longitudinal indicator rod with respect to said second scale. The instrument may be employed to measure the width of the uterine cavity at any position between the inner ostium of the cervix and the fundus.

  4. Depth distribution of glyphosate and AMPA under diferent tillage system and soils in long-term experiments

    NASA Astrophysics Data System (ADS)

    Aparicio, Virginia; Costa, Jose Luis; De Geronimo, Eduardo

    2016-04-01

    Glyphosate (N-(phosphonomethyl glycine) is a post-emergence, non-selective, foliar herbicide. Around 200 million liters of this herbicide are applied every year in Argentina, where the main agricultural practice is no-till (NT), accounting for 78 % of the cultivated land. In this work, we studied the depth distribution of glyphosate in long-term experiments (more than 15 years) at different locations under NT and conventional tillage (CT). Samples from 0-2, 2-5, 5-10, 10-15, and 15-20 cm depth with four replication and two treatments NT CT at three locations: Balcarce (BA) a loam soil, Bordenave (BO) a sandy loam soil y Marcos Juarez a silty loam soil (MJ). The glyphosate concentration in the first 2 cm of soil was, on the average, 70% greater than in the next 2-5 cm. The mass of glyphosate in CT was higher at 2 to 10 cm depth. The depth concentration of AMPA follows the same trend than glyphosate, although its average concentration at 0-2 cm depth is 28 times higher than the glyphosate concentration at 2-5 cm (glyphosate = 147 ppb and AMPA = 4100 ppb). Beside the AMPA concentration at 0-2 cm depth is greater in NT than in CT, the mass of AMPA is higher in CT only for the Balcarce location. To our knowledge, this study is the first dealing with the depth distribution of glyphosate concentration in soils under different soil managements. In the present study, it was demonstrated that glyphosate and AMPA are present in soils under agricultural activity with maximum concentration in the first two cm of soil and the AMPA concentration at this depth is greater in NT than in CT.

  5. The Transition to ICD-10-CM: Challenges for Pediatric Practice

    PubMed Central

    Zaman, Jeffrey; Nam, Hannah; Chae, Sae-Rom; Williams, Lauren; Mathew, Gina; Burton, Michael; Li, Jiarong “John”; Lussier, Yves A.

    2014-01-01

    BACKGROUND AND OBJECTIVES: Diagnostic codes are used widely within health care for billing, quality assessment, and to measure clinical outcomes. The US health care system will transition to the International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM), in October 2015. Little is known about how this transition will affect pediatric practices. The objective of this study was to examine how the transition to ICD-10-CM may result in ambiguity of clinical information and financial disruption for pediatricians. METHODS: Using a statewide data set from Illinois Medicaid specified for pediatricians, 2708 International Classification of Diseases, Ninth Revision, Clinical Modification, diagnosis codes were identified. Diagnosis codes were categorized into 1 of 5 categories: identity, class-to-subclass, subclass-to-class, convoluted, and no translation. The convoluted and high-cost diagnostic codes (n = 636) were analyzed for accuracy and categorized into “information loss,” “overlapping categories,” “inconsistent,” and “consistent.” Finally, reimbursement by Medicaid was calculated for each category. RESULTS: Twenty-six percent of pediatric diagnosis codes are convoluted, which represents 21% of Illinois Medicaid pediatric patient encounters and 16% of reimbursement. The diagnosis codes represented by information loss (3.6%), overlapping categories (3.2%), and inconsistent (1.2%) represent 8% of Medicaid pediatric reimbursement. CONCLUSIONS: The potential for financial disruption and administrative errors from 8% of reimbursement diagnosis codes necessitates special attention to these codes in preparing for the transition to ICD-10-CM for pediatric practices. PMID:24918217

  6. Multiple precursors of secondary mineralogical assemblages in CM chondrites

    NASA Astrophysics Data System (ADS)

    Pignatelli, Isabella; Marrocchi, Yves; Vacher, Lionel. G.; Delon, RéMi; Gounelle, Matthieu

    2016-04-01

    We report a petrographic and mineralogical survey of tochilinite/cronstedtite intergrowths (TCIs) in Paris, a new CM chondrite considered to be the least altered CM identified to date. Our results indicate that type-I TCIs consist of compact tochilinite/cronstedtite rims surrounding Fe-Ni metal beads, thus confirming kamacite as the precursor of type-I TCIs. In contrast, type-II TCIs are characterized by complex compositional zoning composed of three different Fe-bearing secondary minerals: from the outside inwards, tochilinite, cronstedtite, and amakinite. Type-II TCIs present well-developed faces that allow a detailed morphological analysis to be performed in order to identify the precursors. The results demonstrate that type-II TCIs formed by pseudomorphism of the anhydrous silicates, olivine, and pyroxene. Hence, there is no apparent genetic relationship between type-I and type-II TCIs. In addition, the complex chemical zoning observed within type-II TCIs suggests that the alteration conditions evolved dramatically over time. At least three stages of alteration can be proposed, characterized by alteration fluids with varying compositions (1) Fe- and S-rich fluids; (2) S-poor and Fe- and Si-rich fluids; and (3) S- and Si-poor, Fe-rich fluids. The presence of unaltered silicates in close association with euhedral type-II TCIs suggests the existence of microenvironments during the first alteration stages of CM chondrites. In addition, the absence of Mg-bearing secondary minerals in Paris TCIs suggests that the Mg content increases during the course of alteration.

  7. Performance of 30-cm ion thrusters with dished accelerator grids

    NASA Technical Reports Server (NTRS)

    Rawlin, V. K.

    1973-01-01

    Thirteen sets of dished accelerator grids were tested on five different 30-cm diameter bombardment thrustors to evaluate the effects of grid geometry variations on thrustor discharge chamber performance. The dished grid parameters varied were: grid-to-grid spacing, screen and accelerator grid hole-diameter, screen and accelerator open area fraction, compensation for beam divergence losses, and accelerator grid thickness. Also investigated were the effects on discharge chamber performance of main magnetic field changes, magnetic baffle current cathode pole piece length and cathode position.

  8. Performance of 30-cm ion thrusters with dished accelerator grids

    NASA Technical Reports Server (NTRS)

    Rawlin, V. K.

    1973-01-01

    Thirteen sets of dished accelerator grids were treated on five different 30 cm diameter bombardment thrusters to evaluate the effects of grid geometry variations on thruster discharge chamber performance. The dished grid parameters varied were: grid-to-grid spacing, screen and accelerator grid hole diameter, screen and accelerator open area fraction, compensation for beam divergence losses, and accelerator grid thickness. The effects on discharge chamber performance of main magnetic field changes, magnetic baffle current, cathode pole piece length and cathode position were also investigated.

  9. Affordable échelle spectroscopy with a 60 cm telescope

    NASA Astrophysics Data System (ADS)

    Pribulla, T.; Garai, Z.; Hambálek, L.; Kollár, V.; Komžík, R.; Kundra, E.; Nedoroščík, J.; Sekeráš, M.; Vaňko, M

    2015-09-01

    A new fiber-fed spectrograph was installed at the 60 cm telescope of the Stará Lesná Observatory. The article presents tests of its performance (spectral resolution, signal-to-noise ratio, radial-velocity stability) and reports observations of selected variable stars and exoplanet host stars. First test observations show that the spectrograph is an ideal tool to observe bright eclipsing and spectroscopic binaries but also symbiotic and nova-like stars. The radial-velocity stability (60-80 ms-1) is sufficient to study spectroscopic binaries and to detect easily the orbital motion of hot-Jupiter extrasolar planets around bright stars.

  10. The 8-CM ion thruster characterization. [mercury ion engine

    NASA Technical Reports Server (NTRS)

    Wessel, F. J.; Williamson, W. S.

    1983-01-01

    The performance capabilities of the 8 cm diameter mercury ion thruster were increased by modifying the thruster operating parameters and component hardware. The initial performance levels, representative of the Hughes/NASA Lewis Research Center Ion Auxiliary Propulsion Subsystem (IAPS) thruster, were raised from the baseline values of thrust, T = 5 mN, and specific impulse, I sub sp = 2,900s, to thrust, T = 25 mN and specific impulse, I sub sp = 4,300 s. Performance characteristics including estmates of the erosion rates of various component surfaces are presented.

  11. Performance documentation of the engineering model 30-cm diameter thruster

    NASA Technical Reports Server (NTRS)

    Bechtel, R. T.; Rawlin, V. K.

    1976-01-01

    The results of extensive testing of two 30-cm ion thrusters which are virtually identical to the 900 series Engineering Model Thruster in an ongoing 15,000-hour life test are presented. Performance data for the nominal fullpower (2650 W) operating point; performance sensitivities to discharge voltage, discharge losses, accelerator voltage, and magnetic baffle current; and several power throttling techniques (maximum Isp, maximum thrust/power ratio, and two cases in between are included). Criteria for throttling are specified in terms of the screen power supply envelope, thruster operating limits, and control stability. In addition, reduced requirements for successful high voltage recycles are presented.

  12. Performance capabilities of the 8-cm mercury ion thruster

    NASA Technical Reports Server (NTRS)

    Mantenieks, M. A.

    1981-01-01

    A preliminary characterization of the performance capabilities of the 8-cm thruster in order to initiate an evaluation of its application to LSS propulsion requirements is presented. With minor thruster modifications, the thrust was increased by about a factor of four while the discharge voltage was reduced from 39 to 22 volts. The thruster was operated over a range of specific impulse of 1950 to 3040 seconds and a maximum total efficiency of about 54 percent was attained. Preliminary analysis of component lifetimes, as determined by temperature and spectroscopic line intensity measurements, indicated acceptable thruster lifetimes are anticipated at the high power level operation.

  13. Status of 30 cm mercury ion thruster development

    NASA Technical Reports Server (NTRS)

    Sovey, J. S.; King, H. J.

    1974-01-01

    Two engineering model 30-cm ion thrusters were assembled, calibrated, and qualification tested. This paper discusses the thruster design, performance, and power system. Test results include documentation of thrust losses due to doubly charged mercury ions and beam divergence by both direct thrust measurements and beam probes. Diagnostic vibration tests have led to improved designs of the thruster backplate structure, feed system, and harness. Thruster durability is being demonstrated over a thrust range of 97 to 113 mN at a specific impulse of about 2900 seconds. As of August 15, 1974, the thruster has successfully operated for over 4000 hours.

  14. Recycle Requirements for NASA's 30 cm Xenon Ion Thruster

    NASA Technical Reports Server (NTRS)

    Pinero, Luis R.; Rawlin, Vincent K.

    1994-01-01

    Electrical breakdowns have been observed during ion thruster operation. These breakdowns, or arcs, can be caused by several conditions. In flight systems, the power processing unit must be designed to handle these faults autonomously. This has a strong impact on power processor requirements and must be understood fully for the power processing unit being designed for the NASA Solar Electric Propulsion Technology Application Readiness program. In this study, fault conditions were investigated using a NASA 30 cm ion thruster and a power console. Power processing unit output specifications were defined based on the breakdown phenomena identified and characterized.

  15. Control of a 30 cm diameter mercury bombardment thruster

    NASA Technical Reports Server (NTRS)

    Terdan, F. F.; Bechtel, R. T.

    1973-01-01

    Increased thruster performance has made closed-loop automatic control more difficult than previously. Specifically, high perveance optics tend to make reliable recycling more difficult. Control logic functions were established for three automatic modes of operation of a 30-cm thruster using a power conditioner console with flight-like characteristics. The three modes provide (1) automatic startup to reach thermal stability, (2) steady-state closed-loop control, and (3) the reliable recycling of the high voltages following an arc breakdown to reestablish normal operation. Power supply impedance characteristics necessary for stable operation and the effect of the magnetic baffle on the reliable recycling was studied.

  16. Radiated and conducted EMI from a 30-cm ion thruster

    NASA Technical Reports Server (NTRS)

    Whittlesey, A. C.; Peer, W.

    1981-01-01

    In order to properly assess the interaction of a spacecraft with the EMI environment produced by an ion thruster, the EMI environment was characterized. Therefore, radiated and conducted emissions were measured from a 30-cm mercury ion thruster. The ion thruster beam current varied from zero to 2.0 amperes and the emissions were measured from 5 KHz to 200 MHz. Several different types of antennas were used to obtain the measurements. The various measurements that were made included: magnetic field due to neutralizer/beam current loop; radiated electric fields of thruster and plume; and conducted emissions on arc discharge, neutralizer keeper and magnetic baffle lines.

  17. Long lifetime hollow cathodes for 30-cm mercury ion thrusters

    NASA Technical Reports Server (NTRS)

    Mirtich, M. J.; Kerslake, W. R.

    1976-01-01

    An experimental investigation of hollow cathodes for 30-cm Hg bombardment thrusters was carried out. Both main and neutralizer cathode configurations were tested with both rolled foil inserts coated with low work function material and impregnated porous tungsten inserts. Temperature measurements of an impregnated insert at various positions in the cathode were made. These, along with the cathode thermal profile are presented. A theory for rolled foil and impregnated insert operation and lifetime in hollow cathodes is developed. Several endurance tests, as long as 18000 hours at emission currents of up to 12 amps were attained with no degradation in performance.

  18. Performance mapping of a 30 cm engineering model thruster

    NASA Technical Reports Server (NTRS)

    Poeschel, R. L.; Vahrenkamp, R. P.

    1975-01-01

    A 30 cm thruster representative of the engineering model design has been tested over a wide range of operating parameters to document performance characteristics such as electrical and propellant efficiencies, double ion and beam divergence thrust loss, component equilibrium temperatures, operational stability, etc. Data obtained show that optimum power throttling, in terms of maximum thruster efficiency, is not highly sensitive to parameter selection. Consequently, considerations of stability, discharge chamber erosion, thrust losses, etc. can be made the determining factors for parameter selection in power throttling operations. Options in parameter selection based on these considerations are discussed.

  19. The 100 cm solar telescope primary mirror study

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The manufacturing impact of primary mirror configuration on the performance of a 100 cm aperture solar telescope was studied. Three primary mirror configurations were considered: solid, standard lightweight, and mushroom. All of these are of low expansion material. Specifically, the study consisted of evaluating the mirrors with regard to: manufacturing metrology, manufacturing risk factors and ultimate quality assessment. As a result of this evaluation, a performance comparison of the configurations was made, and a recommendation of mirror configuration is the final output. These evaluations, comparisons and recommendations are discussed in detail. Other investigations were completed and are documented in the appendices.

  20. Human Being Imaging with cm-Wave UWB Radar

    NASA Astrophysics Data System (ADS)

    Yarovoy, A.; Zhuge, X.; Savelyev, T.; Matuzas, J.; Levitas, B.

    Possibilities of high-resolution human body imaging and concealed weapon detection using centimeter-wave microwave frequencies are investigated. Dependencies of the cross-range resolution of different imaging techniques on operational bandwidth, center frequency, imaging aperture size, and imaging topology have been studied. It has been demonstrated that the cross-range resolution of 2 cm can be achieved using frequencies below 10 GHz. These findings have been verified experimentally by producing high-resolution images of a foil-covered doll and some weapons.

  1. Interdecadal changes in snow depth on Arctic sea ice

    NASA Astrophysics Data System (ADS)

    Webster, Melinda A.; Rigor, Ignatius G.; Nghiem, Son V.; Kurtz, Nathan T.; Farrell, Sinead L.; Perovich, Donald K.; Sturm, Matthew

    2014-08-01

    Snow plays a key role in the growth and decay of Arctic sea ice. In winter, it insulates sea ice from cold air temperatures, slowing sea ice growth. From spring to summer, the albedo of snow determines how much insolation is absorbed by the sea ice and underlying ocean, impacting ice melt processes. Knowledge of the contemporary snow depth distribution is essential for estimating sea ice thickness and volume, and for understanding and modeling sea ice thermodynamics in the changing Arctic. This study assesses spring snow depth distribution on Arctic sea ice using airborne radar observations from Operation IceBridge for 2009-2013. Data were validated using coordinated in situ measurements taken in March 2012 during the Bromine, Ozone, and Mercury Experiment (BROMEX) field campaign. We find a correlation of 0.59 and root-mean-square error of 5.8 cm between the airborne and in situ data. Using this relationship and IceBridge snow thickness products, we compared the recent results with data from the 1937, 1954-1991 Soviet drifting ice stations. The comparison shows thinning of the snowpack, from 35.1 ± 9.4 to 22.2 ± 1.9 cm in the western Arctic, and from 32.8 ± 9.4 to 14.5 ± 1.9 cm in the Beaufort and Chukchi seas. These changes suggest a snow depth decline of 37 ± 29% in the western Arctic and 56 ± 33% in the Beaufort and Chukchi seas. Thinning is negatively correlated with the delayed onset of sea ice freezeup during autumn.

  2. Acoustically enriching, large-depth aquatic sampler.

    PubMed

    Jonsson, Jonas; Ogden, Sam; Johansson, Linda; Hjort, Klas; Thornell, Greger

    2012-05-01

    In marine biology, it is useful to collect water samples when exploring the distribution and diversity of microbial communities in underwater environments. In order to provide, e.g., a miniaturized submersible explorer with the capability of collecting microorganisms, a compact sample enrichment system has been developed. The sampler is 30 mm long, 15 mm wide, and just a few millimetres thick. Integrated in a multilayer steel, polyimide and glass construction is a microfluidic channel with piezoelectric transducers, where microorganism and particle samples are collected and enriched, using acoustic radiation forces for gentle and labelless trapping. High-pressure, latchable valves, using paraffin as the actuation material, at each end of the microfluidic channel keep the collected sample pristine. A funnel structure raised above the surface of the device directs water into the microfluidic channel as the vehicle propels itself or when there is a flow across its hull. The valves proved leak proof to a pressure of 2.1 MPa for 19 hours and momentary pressures of 12.5 MPa, corresponding to an ocean depth of more than 1200 metres. By reactivating the latching mechanism, small leakages through the valves could be remedied, which could thus increase the leak-less operational time. Fluorescent particles, 1.9 μm in diameter, were successfully trapped in the microfluidic channel at flow rates up to 15 μl min(-1), corresponding to an 18.5 cm s(-1) external flow rate of the sampler. In addition, liquid-suspended GFP-marked yeast cells were successfully trapped.

  3. Acoustically enriching, large-depth aquatic sampler.

    PubMed

    Jonsson, Jonas; Ogden, Sam; Johansson, Linda; Hjort, Klas; Thornell, Greger

    2012-05-01

    In marine biology, it is useful to collect water samples when exploring the distribution and diversity of microbial communities in underwater environments. In order to provide, e.g., a miniaturized submersible explorer with the capability of collecting microorganisms, a compact sample enrichment system has been developed. The sampler is 30 mm long, 15 mm wide, and just a few millimetres thick. Integrated in a multilayer steel, polyimide and glass construction is a microfluidic channel with piezoelectric transducers, where microorganism and particle samples are collected and enriched, using acoustic radiation forces for gentle and labelless trapping. High-pressure, latchable valves, using paraffin as the actuation material, at each end of the microfluidic channel keep the collected sample pristine. A funnel structure raised above the surface of the device directs water into the microfluidic channel as the vehicle propels itself or when there is a flow across its hull. The valves proved leak proof to a pressure of 2.1 MPa for 19 hours and momentary pressures of 12.5 MPa, corresponding to an ocean depth of more than 1200 metres. By reactivating the latching mechanism, small leakages through the valves could be remedied, which could thus increase the leak-less operational time. Fluorescent particles, 1.9 μm in diameter, were successfully trapped in the microfluidic channel at flow rates up to 15 μl min(-1), corresponding to an 18.5 cm s(-1) external flow rate of the sampler. In addition, liquid-suspended GFP-marked yeast cells were successfully trapped. PMID:22422039

  4. Measuring the Cosmological 21 cm Monopole with an Interferometer

    NASA Astrophysics Data System (ADS)

    Presley, Morgan E.; Liu, Adrian; Parsons, Aaron R.

    2015-08-01

    A measurement of the cosmological 21 {cm} signal remains a promising but as-of-yet unattained ambition of radio astronomy. A positive detection would provide direct observations of key unexplored epochs of our cosmic history, including the cosmic dark ages and reionization. In this paper, we concentrate on measurements of the spatial monopole of the 21 {cm} brightness temperature as a function of redshift (the “global signal”). Most global experiments to date have been single-element experiments. In this paper, we show how an interferometer can be designed to be sensitive to the monopole mode of the sky, thus providing an alternate approach to accessing the global signature. We provide simple rules of thumb for designing a global signal interferometer and use numerical simulations to show that a modest array of tightly packed antenna elements with moderately sized primary beams (FWHM of ∼ 40^\\circ ) can compete with typical single-element experiments in their ability to constrain phenomenological parameters pertaining to reionization and the pre-reionization era. We also provide a general data analysis framework for extracting the global signal from interferometric measurements (with analysis of single-element experiments arising as a special case) and discuss trade-offs with various data analysis choices. Given that interferometric measurements are able to avoid a number of systematics inherent in single-element experiments, our results suggest that interferometry ought to be explored as a complementary way to probe the global signal.

  5. Power processor for a 20CM ion thruster

    NASA Technical Reports Server (NTRS)

    Biess, J. J.; Schoenfeld, A. D.; Cohen, E.

    1973-01-01

    A power processor breadboard for the JPL 20CM Ion Engine was designed, fabricated, and tested to determine compliance with the electrical specification. The power processor breadboard used the silicon-controlled rectifier (SCR) series resonant inverter as the basic power stage to process all the power to the ion engine. The breadboard power processor was integrated with the JPL 20CM ion engine and complete testing was performed. The integration tests were performed without any silicon-controlled rectifier failure. This demonstrated the ruggedness of the series resonant inverter in protecting the switching elements during arcing in the ion engine. A method of fault clearing the ion engine and returning back to normal operation without elaborate sequencing and timing control logic was evolved. In this method, the main vaporizer was turned off and the discharge current limit was reduced when an overload existed on the screen/accelerator supply. After the high voltage returned to normal, both the main vaporizer and the discharge were returned to normal.

  6. Characterization of an 8-cm Diameter Ion Source System

    NASA Technical Reports Server (NTRS)

    Li, Zhongmin; Hawk, C. W.; Hawk, Clark W.; Buttweiler, Mark S.; Williams, John D.; Buchholtz, Brett

    2005-01-01

    Results of tests characterizing an 8-cm diameter ion source are presented. The tests were conducted in three separate vacuum test facilities at the University of Alabama-Huntsville, Colorado State University, and L3 Communications' ETI division. Standard ion optics tests describing electron backstreaming and total-voltage-limited impingement current behavior as a function of beam current were used as guidelines for selecting operating conditions where more detailed ion beam measurements were performed. The ion beam was profiled using an in-vacuum actuating probe system to determine the total ion current density and the ion charge state distribution variation across the face of the ion source. Both current density and ExB probes were utilized. The ion current density data were used to obtain integrated beam current, beam flatness parameters, and general beam profile shapes. The ExB probe data were used to determine the ratio of doubly to singly charged ion current. The ion beam profile tests were performed at over six different operating points that spanned the expected operating range of the DAWN thrusters being developed at L3. The characterization tests described herein reveal that the 8-cm ion source is suitable for use in (a) validating plasma diagnostic equipment, (b) xenon ion sputtering and etching studies of spacecraft materials, (c) plasma physics research, and (d) the study of ion thruster optics at varying conditions.

  7. Presolar grains in the CM2 chondrite Sutter's Mill

    NASA Astrophysics Data System (ADS)

    Zhao, Xuchao; Lin, Yangting; Yin, Qing-Zhu; Zhang, Jianchao; Hao, Jialong; Zolensky, Michael; Jenniskens, Peter

    2014-11-01

    The Sutter's Mill (SM) carbonaceous chondrite is a regolith breccia, composed predominantly of CM2 clasts with varying degrees of aqueous alteration and thermal metamorphism. An investigation of presolar grains in four Sutter's Mill sections, SM43, SM51, SM2-4, and SM18, was carried out using NanoSIMS ion mapping technique. A total of 37 C-anomalous grains and one O-anomalous grain have been identified, indicating an abundance of 63 ppm for presolar C-anomalous grains and 2 ppm for presolar oxides. Thirty-one silicon carbide (SiC), five carbonaceous grains, and one Al-oxide (Al2O3) were confirmed based on their elemental compositions determined by C-N-Si and O-Si-Mg-Al isotopic measurements. The overall abundance of SiC grains in Sutter's Mill (55 ppm) is consistent with those in other CM chondrites. The absence of presolar silicates in Sutter's Mill suggests that they were destroyed by aqueous alteration on the parent asteroid. Furthermore, SM2-4 shows heterogeneous distributions of presolar SiC grains (12-54 ppm) in different matrix areas, indicating that the fine-grained matrix clasts come from different sources, with various thermal histories, in the solar nebula.

  8. Altimeter error sources at the 10-cm performance level

    NASA Technical Reports Server (NTRS)

    Martin, C. F.

    1977-01-01

    Error sources affecting the calibration and operational use of a 10 cm altimeter are examined to determine the magnitudes of current errors and the investigations necessary to reduce them to acceptable bounds. Errors considered include those affecting operational data pre-processing, and those affecting altitude bias determination, with error budgets developed for both. The most significant error sources affecting pre-processing are bias calibration, propagation corrections for the ionosphere, and measurement noise. No ionospheric models are currently validated at the required 10-25% accuracy level. The optimum smoothing to reduce the effects of measurement noise is investigated and found to be on the order of one second, based on the TASC model of geoid undulations. The 10 cm calibrations are found to be feasible only through the use of altimeter passes that are very high elevation for a tracking station which tracks very close to the time of altimeter track, such as a high elevation pass across the island of Bermuda. By far the largest error source, based on the current state-of-the-art, is the location of the island tracking station relative to mean sea level in the surrounding ocean areas.

  9. Electric prototype power processor for a 30cm ion thruster

    NASA Technical Reports Server (NTRS)

    Biess, J. J.; Inouye, L. Y.; Schoenfeld, A. D.

    1977-01-01

    An electrical prototype power processor unit was designed, fabricated and tested with a 30 cm mercury ion engine for primary space propulsion. The power processor unit used the thyristor series resonant inverter as the basic power stage for the high power beam and discharge supplies. A transistorized series resonant inverter processed the remaining power for the low power outputs. The power processor included a digital interface unit to process all input commands and internal telemetry signals so that electric propulsion systems could be operated with a central computer system. The electrical prototype unit included design improvement in the power components such as thyristors, transistors, filters and resonant capacitors, and power transformers and inductors in order to reduce component weight, to minimize losses, and to control the component temperature rise. A design analysis for the electrical prototype is also presented on the component weight, losses, part count and reliability estimate. The electrical prototype was tested in a thermal vacuum environment. Integration tests were performed with a 30 cm ion engine and demonstrated operational compatibility. Electromagnetic interference data was also recorded on the design to provide information for spacecraft integration.

  10. Depth enhanced and content aware video stabilization

    NASA Astrophysics Data System (ADS)

    Lindner, A.; Atanassov, K.; Goma, S.

    2015-03-01

    We propose a system that uses depth information for video stabilization. The system uses 2D-homographies as frame pair transforms that are estimated with keypoints at the depth of interest. This makes the estimation more robust as the points lie on a plane. The depth of interest can be determined automatically from the depth histogram, inferred from user input such as tap-to-focus, or selected by the user; i.e., tap-to-stabilize. The proposed system can stabilize videos on the fly in a single pass and is especially suited for mobile phones with multiple cameras that can compute depth maps automatically during image acquisition.

  11. Is visual short-term memory depthful?

    PubMed

    Reeves, Adam; Lei, Quan

    2014-03-01

    Does visual short-term memory (VSTM) depend on depth, as it might be if information was stored in more than one depth layer? Depth is critical in natural viewing and might be expected to affect retention, but whether this is so is currently unknown. Cued partial reports of letter arrays (Sperling, 1960) were measured up to 700 ms after display termination. Adding stereoscopic depth hardly affected VSTM capacity or decay inferred from total errors. The pattern of transposition errors (letters reported from an uncued row) was almost independent of depth and cue delay. We conclude that VSTM is effectively two-dimensional. PMID:24491386

  12. PAPER-64 Constraints on Reionization: The 21 cm Power Spectrum at z = 8.4

    NASA Astrophysics Data System (ADS)

    Ali, Zaki S.; Parsons, Aaron R.; Zheng, Haoxuan; Pober, Jonathan C.; Liu, Adrian; Aguirre, James E.; Bradley, Richard F.; Bernardi, Gianni; Carilli, Chris L.; Cheng, Carina; DeBoer, David R.; Dexter, Matthew R.; Grobbelaar, Jasper; Horrell, Jasper; Jacobs, Daniel C.; Klima, Pat; MacMahon, David H. E.; Maree, Matthys; Moore, David F.; Razavi, Nima; Stefan, Irina I.; Walbrugh, William P.; Walker, Andre

    2015-08-01

    In this paper, we report new limits on 21 cm emission from cosmic reionization based on a 135 day observing campaign with a 64-element deployment of the Donald C. Backer Precision Array for Probing the Epoch of Reionization in South Africa. This work extends the work presented in Parsons et al. with more collecting area, a longer observing period, improved redundancy-based calibration, improved fringe-rate filtering, and updated power-spectral analysis using optimal quadratic estimators. The result is a new 2σ upper limit on Δ2(k) of (22.4 mK)2 in the range 0.15\\lt k\\lt 0.5h {{Mpc}}-1 at z = 8.4. This represents a three-fold improvement over the previous best upper limit. As we discuss in more depth in a forthcoming paper, this upper limit supports and extends previous evidence against extremely cold reionization scenarios. We conclude with a discussion of implications for future 21 cm reionization experiments, including the newly funded Hydrogen Epoch of Reionization Array.

  13. Estimation of optimal pediatric chest compression depth by using computed tomography

    PubMed Central

    Jin, Soo Young; Oh, Seong Beom; Kim, Young Oh

    2016-01-01

    Objective This study aimed to compare the optimal chest compression depth for infants and children with that of adults when the simulated compression depth was delivered according to the current guidelines. Methods A total of 467 consecutive chest computed tomography scans (93 infants, 110 children, and 264 adults) were reviewed. The anteroposterior diameter and compressible diameter (CD) for infants and children were measured at the inter-nipple level and at the mid-lower half of the spine for adults. Compression ratio (CR) to CD was calculated at simulated 1/4, 1/3, and 1/2 antero-posterior compressions in infants and children, and simulated 5- and 6-cm compressions in adults. Results In adults, the CRs to CD at simulated 5- and 6-cm compression depth were 41.7±0.16%, 50.0±7.3% respectively. In children and infants, the CRs to CD at 1/3 chest compression were 55.1±2.4% and 51.8±2.4%, respectively, and at 1/2 chest compression, CRs were 82.7±3.7% and 77.7±3.6%, respectively. The CRs to CD of 4-cm compression depth in infants and 5-cm compression depth in children were 74.4±10.9%, 62.5±8.7%, respectively. The CRs to CD for children and infants were significantly higher than in adults (P<0.001). The CR to CD of 4-cm compression depth in children was almost similar to that of 6-cm compression depth in adults (50.0± 6.9% vs. 50.0±7.3%, P=0.985). Conclusion Current pediatric guidelines for compression depth are too deep compared to those in adults. We suggest using 1/3 of the anteroposterior chest diameter or about 4 cm in children and less than 4 cm in infants. PMID:27752612

  14. Influence of measurement depth on the stiffness assessment of healthy liver with real-time shear wave elastography.

    PubMed

    Wang, Cong-Zhi; Zheng, Jian; Huang, Ze-Ping; Xiao, Yang; Song, Dan; Zeng, Jie; Zheng, Hai-Rong; Zheng, Rong-Qin

    2014-03-01

    The purpose of this study was to determine the measurement depth range within which liver stiffness can be reliably assessed using real-time shear wave elastography (SWE) technology. Measurements were performed on phantoms and healthy volunteers. In the first group of patients, measurements were performed at depths of 2-8 cm from the probe surface. In the second group of patients, measurements were conducted 0-7 cm below the liver capsule. Success rate of measurements (SRoM), success rate of patients (SRoS) and coefficients of variation (CVs) of repeated measurements were compared. The SRoMs at 3-7 cm and the CVs at 2-5 cm from the probe surface were significantly higher and lower than those at other depths (p < 0.001), respectively. SRoS was zero 0-1 cm below the liver capsule. Furthermore, the features of 2-D stiffness mapping images were also found to change with depth. According to our results, the depth range for the most reliable liver stiffness assessment using SWE should be 3-5 cm from the probe surface and simultaneously 1-2 cm below the liver capsule.

  15. Wavelength-dependent penetration depth of near infrared radiation into cartilage.

    PubMed

    Padalkar, M V; Pleshko, N

    2015-04-01

    Articular cartilage is a hyaline cartilage that lines the subchondral bone in the diarthrodial joints. Near infrared (NIR) spectroscopy is emerging as a nondestructive modality for the evaluation of cartilage pathology; however, studies regarding the depth of penetration of NIR radiation into cartilage are lacking. The average thickness of human cartilage is about 1-3 mm, and it becomes even thinner as OA progresses. To ensure that spectral data collected is restricted to the tissue of interest, i.e. cartilage in this case, and not from the underlying subchondral bone, it is necessary to determine the depth of penetration of NIR radiation in different wavelength (frequency) regions. In the current study, we establish how the depth of penetration varies throughout the NIR frequency range (4000-10 000 cm(-1)). NIR spectra were collected from cartilage samples of different thicknesses (0.5 mm to 5 mm) with and without polystyrene placed underneath. A separate NIR spectrum of polystyrene was collected as a reference. It was found that the depth of penetration varied from ∼1 mm to 2 mm in the 4000-5100 cm(-1) range, ∼3 mm in the 5100-7000 cm(-1) range, and ∼5 mm in the 7000-9000 cm(-1) frequency range. These findings suggest that the best NIR region to evaluate cartilage with no subchondral bone contribution is in the range of 4000-7000 cm(-1).

  16. Wavelength-Dependent Penetration Depth of Near Infrared Radiation into Cartilage

    PubMed Central

    Padalkar, M.V.; Pleshko, N.

    2015-01-01

    Articular cartilage is a hyaline cartilage that lines the subchondral bone in a diarthrodial joint. Near infrared (NIR) spectroscopy has been emerging as a nondestructive modality for evaluation of cartilage pathology. However, studies of the depth of penetration of NIR radiation into cartilage are lacking. The average thickness of human cartilage is about 1-3 mm, and it becomes even thinner as OA progresses. To ensure that the spectral data collected is restricted to the tissue of interest i.e. cartilage in this case, and not from the underlying subchondral bone, it is necessary to determine the depth of penetration of NIR radiation in different wavelength (frequency) regions. In the current study we establish how the depth of penetration varies throughout the NIR frequency range (4000-10000 cm-1). NIR spectra were collected from cartilage samples of different thicknesses (0.5 mm to 5 mm) with and without polystyrene placed underneath. A separate NIR spectrum of polystyrene was collected as a reference. It was found that the depth of penetration varied from ∼1 mm to 2 mm in the 4000-5100 cm-1 range, to ∼3 mm in the 5100-7000 cm-1 range, and to ∼5 mm in the 7000-9000 cm-1 frequency range. These findings suggest that the best NIR region to evaluate cartilage only with no subchondral bone contribution is between 4000-7000 cm-1. PMID:25630381

  17. P-O-rich sulfide phase in CM chondrites: Constraints on its origin on the CM parent body

    NASA Astrophysics Data System (ADS)

    Zhang, Ai-Cheng; Itoh, Shoichi; Yurimoto, Hisayoshi; Hsu, Wei-Biao; Wang, Ru-Cheng; Taylor, Lawrence A.

    2016-01-01

    CM chondrites are a group of primitive meteorites that have recorded the alteration history of the early solar system. We report the occurrence, chemistry, and oxygen isotopic compositions of P-O-rich sulfide phase in two CM chondrites (Grove Mountains [GRV] 021536 and Murchison). This P-O-rich sulfide is a polycrystalline aggregate of nanometer-size grains. It occurs as isolated particles or aggregates in both CM chondrites. These grains, in the matrix and in type-I chondrules from Murchison, were partially altered into tochilinite; however, grains enclosed by Ca-carbonate are much less altered. This P-O-rich sulfide in Murchison is closely associated with magnetite, FeNi phosphide, brezinaite (Cr3S4), and eskolaite (Cr2O3). In addition to sulfur as the major component, this sulfide contains ~6.3 wt% O, ~5.4 wt% P, and minor amounts of hydrogen. Analyses of oxygen isotopes by SIMS resulted in an average δ18O value of -22.5 ‰ and an average Δ17O value of 0.2 ± 9.2 ‰ (2σ). Limited variations in both chemical compositions and electron-diffraction patterns imply that the P-O-rich sulfide may be a single phase rather than a polyphase mixture. Several features indicate that this P-O-rich sulfide phase formed at low temperature on the parent body, most likely through the alteration of FeNi metal (a) close association with other low-temperature alteration products, (b) the presence of hydrogen, (c) high Δ17O values and the presence in altered mesostasis of type-I chondrules and absence in type-II chondrules. The textural relations of the P-O-rich sulfide and other low-temperature minerals reveal at least three episodic-alteration events on the parent body of CM chondrites (1) formation of P-O-rich sulfide during sulfur-rich aqueous alteration of P-rich FeNi metal, (2) formation of Ca-carbonate during local carbonation, and (3) alteration of P-O-rich sulfide and formation of tochilinite during a period of late-stage intensive aqueous alteration.

  18. A comparative study of intervening and associated H I 21-cm absorption profiles in redshifted galaxies

    NASA Astrophysics Data System (ADS)

    Curran, S. J.; Duchesne, S. W.; Divoli, A.; Allison, J. R.

    2016-08-01

    The star-forming reservoir in the distant Universe can be detected through H I 21-cm absorption arising from either cool gas associated with a radio source or from within a galaxy intervening the sight-line to the continuum source. In order to test whether the nature of the absorber can be predicted from the profile shape, we have compiled and analysed all of the known redshifted (z ≥ 0.1) H I 21-cm absorption profiles. Although between individual spectra there is too much variation to assign a typical spectral profile, we confirm that associated absorption profiles are, on average, wider than their intervening counterparts. It is widely hypothesised that this is due to high velocity nuclear gas feeding the central engine, absent in the more quiescent intervening absorbers. Modelling the column density distribution of the mean associated and intervening spectra, we confirm that the additional low optical depth, wide dispersion component, typical of associated absorbers, arises from gas within the inner parsec. With regard to the potential of predicting the absorber type in the absence of optical spectroscopy, we have implemented machine learning techniques to the 55 associated and 43 intervening spectra, with each of the tested models giving a ≳80% accuracy in the prediction of the absorber type. Given the impracticability of follow-up optical spectroscopy of the large number of 21-cm detections expected from the next generation of large radio telescopes, this could provide a powerful new technique with which to determine the nature of the absorbing galaxy.

  19. A comparative study of intervening and associated H I 21-cm absorption profiles in redshifted galaxies

    NASA Astrophysics Data System (ADS)

    Curran, S. J.; Duchesne, S. W.; Divoli, A.; Allison, J. R.

    2016-11-01

    The star-forming reservoir in the distant Universe can be detected through H I 21-cm absorption arising from either cool gas associated with a radio source or from within a galaxy intervening the sightline to the continuum source. In order to test whether the nature of the absorber can be predicted from the profile shape, we have compiled and analysed all of the known redshifted (z ≥ 0.1) H I 21-cm absorption profiles. Although between individual spectra there is too much variation to assign a typical spectral profile, we confirm that associated absorption profiles are, on average, wider than their intervening counterparts. It is widely hypothesized that this is due to high-velocity nuclear gas feeding the central engine, absent in the more quiescent intervening absorbers. Modelling the column density distribution of the mean associated and intervening spectra, we confirm that the additional low optical depth, wide dispersion component, typical of associated absorbers, arises from gas within the inner parsec. With regard to the potential of predicting the absorber type in the absence of optical spectroscopy, we have implemented machine learning techniques to the 55 associated and 43 intervening spectra, with each of the tested models giving a ≳ 80 per cent accuracy in the prediction of the absorber type. Given the impracticability of follow-up optical spectroscopy of the large number of 21-cm detections expected from the next generation of large radio telescopes, this could provide a powerful new technique with which to determine the nature of the absorbing galaxy.

  20. Investigation of extensive air shower development using large slant depth of atmosphere

    NASA Astrophysics Data System (ADS)

    Sokhoyan, S. H.; Chilingarian, A. A.; Gharagyozyan, G. V.; Ghazaryan, S. S.; Hovsepyan, G. G.; Melkumyan, L. G.

    Using the EAS size spectra measured with the MAKET ANI array on on Mt. Aragats, Armenia (3200m a.s.l., 700g · cm-2 ) in the range Ne = 105 - 107 for different angles-of-incidence, the EAS attenuation length has been determined applying different analysis methods. Energy dependence of the attenuation length at large slant depth of atmosphere (700 - 1250g/cm2 ) is obtained and discussed.

  1. Estimation of foot pressure from human footprint depths using 3D scanner

    NASA Astrophysics Data System (ADS)

    Wibowo, Dwi Basuki; Haryadi, Gunawan Dwi; Priambodo, Agus

    2016-03-01

    The analysis of normal and pathological variation in human foot morphology is central to several biomedical disciplines, including orthopedics, orthotic design, sports sciences, and physical anthropology, and it is also important for efficient footwear design. A classic and frequently used approach to study foot morphology is analysis of the footprint shape and footprint depth. Footprints are relatively easy to produce and to measure, and they can be preserved naturally in different soils. In this study, we need to correlate footprint depth with corresponding foot pressure of individual using 3D scanner. Several approaches are used for modeling and estimating footprint depths and foot pressures. The deepest footprint point is calculated from z max coordinate-z min coordinate and the average of foot pressure is calculated from GRF divided to foot area contact and identical with the average of footprint depth. Evaluation of footprint depth was found from importing 3D scanner file (dxf) in AutoCAD, the z-coordinates than sorted from the highest to the lowest value using Microsoft Excel to make footprinting depth in difference color. This research is only qualitatif study because doesn't use foot pressure device as comparator, and resulting the maximum pressure on calceneus is 3.02 N/cm2, lateral arch is 3.66 N/cm2, and metatarsal and hallux is 3.68 N/cm2.

  2. Depth of artificial Burrowing Owl burrows affects thermal suitability and occupancy

    USGS Publications Warehouse

    Nadeau, Christopher P.; Conway, Courtney J.; Rathbun, Nathan

    2015-01-01

    Many organizations have installed artificial burrows to help bolster local Burrowing Owl (Athene cunicularia) populations. However, occupancy probability and reproductive success in artificial burrows varies within and among burrow installations. We evaluated the possibility that depth below ground might explain differences in occupancy probability and reproductive success by affecting the temperature of artificial burrows. We measured burrow temperatures from March to July 2010 in 27 artificial burrows in southern California that were buried 15–76 cm below the surface (measured between the surface and the top of the burrow chamber). Burrow depth was one of several characteristics that affected burrow temperature. Burrow temperature decreased by 0.03°C per cm of soil on top of the burrow. The percentage of time that artificial burrows provided a thermal refuge from above-ground temperature decreased with burrow depth and ranged between 50% and 58% among burrows. The percentage of time that burrow temperature was optimal for incubating females also decreased with burrow depth and ranged between 27% and 100% among burrows. However, the percentage of time that burrow temperature was optimal for unattended eggs increased with burrow depth and ranged between 11% and 95% among burrows. We found no effect of burrow depth on reproductive success across 21 nesting attempts. However, occupancy probability had a non-linear relationship with burrow depth. The shallowest burrows (15 cm) had a moderate probability of being occupied (0.46), burrows between 28 and 40 cm had the highest probability of being occupied (>0.80), and burrows >53 cm had the lowest probability of being occupied (<0.43). Burrowing Owls may prefer burrows at moderate depths because these burrows provide a thermal refuge from above-ground temperatures, and are often cool enough to allow females to leave eggs unattended before the onset of full-time incubation, but not too cool for incubating females that

  3. 15 cm cusped magnetic field mercury ion thruster research

    NASA Technical Reports Server (NTRS)

    Beattie, J. R.; Wilbur, P. J.

    1975-01-01

    The importance of achieving a uniform current density in the exhaust beam of an electrostatic ion thruster is discussed in terms of thrust level and accelerator grid lifetime. A neutral residence time approach is used to propose a magnetic field geometry which should produce a highly uniform beam current density. The discharge chamber length to diameter ratio is shown to be an important optimization parameter and experimental evaluation of the cusped field thruster over a wide range of this parameter is presented. Beam profile measurements 5 cm downstream of the accelerator grid indicate a beam profile flatness parameter which is 25% greater than the SERT II value. Flatness parameters extrapolated to the plane of the accelerator grid are demonstrated to be as high as 0.9.

  4. Gravitational-wave detection using redshifted 21-cm observations

    SciTech Connect

    Bharadwaj, Somnath; Guha Sarkar, Tapomoy

    2009-06-15

    A gravitational-wave traversing the line of sight to a distant source produces a frequency shift which contributes to redshift space distortion. As a consequence, gravitational waves are imprinted as density fluctuations in redshift space. The gravitational-wave contribution to the redshift space power spectrum has a different {mu} dependence as compared to the dominant contribution from peculiar velocities. This, in principle, allows the two signals to be separated. The prospect of a detection is most favorable at the highest observable redshift z. Observations of redshifted 21-cm radiation from neutral hydrogen hold the possibility of probing very high redshifts. We consider the possibility of detecting primordial gravitational waves using the redshift space neutral hydrogen power spectrum. However, we find that the gravitational-wave signal, though present, will not be detectable on superhorizon scales because of cosmic variance and on subhorizon scales where the signal is highly suppressed.

  5. Translation Optics for 30 cm Ion Engine Thrust Vector Control

    NASA Technical Reports Server (NTRS)

    Haag, Thomas

    2002-01-01

    Data were obtained from a 30 cm xenon ion thruster in which the accelerator grid was translated in the radial plane. The thruster was operated at three different throttle power levels, and the accelerator grid was incrementally translated in the X, Y, and azimuthal directions. Plume data was obtained downstream from the thruster using a Faraday probe mounted to a positioning system. Successive probe sweeps revealed variations in the plume direction. Thruster perveance, electron backstreaming limit, accelerator current, and plume deflection angle were taken at each power level, and for each accelerator grid position. Results showed that the thruster plume could easily be deflected up to six degrees without a prohibitive increase in accelerator impingement current. Results were similar in both X and Y direction.

  6. An H I 21-cm line survey of evolved stars

    NASA Astrophysics Data System (ADS)

    Gérard, E.; Le Bertre, T.; Libert, Y.

    2011-12-01

    The HI line at 21 cm is a tracer of circumstellar matter around AGB stars, and especially of the matter located at large distances (0.1-1 pc) from the central stars. It can give unique information on the kinematics and on the physical conditions in the outer parts of circumstellar shells and in the regions where stellar matter is injected into the interstellar medium. However this tracer has not been much used up to now, due to the difficulty of separating the genuine circumstellar emission from the interstellar one. With the Nançay Radiotelescope we are carrying out a survey of the HI emission in a large sample of evolved stars. We report on recent progresses of this long term programme, with emphasis on S-type stars.

  7. Autumn at Titan's South Pole: The 220 cm-1 Cloud

    NASA Astrophysics Data System (ADS)

    Jennings, D. E.; Cottini, V.; Achterberg, R. K.; Anderson, C. M.; Flasar, F. M.; de Kok, R. J.; Teanby, N. A.; Coustenis, A.; Vinatier, S.

    2015-10-01

    Beginning in 2012 an atmospheric cloud known by its far-infrared emission has formed rapidly at Tit an's South Pole [1, 2]. The build-up of this condensate is a result of deepening temperatures and a gathering of gases as Winter approaches. Emission from the cloud in the south has been doubling each year since 2012, in contrast to the north where it has halved every 3.8 years since 2004. The morphology of the cloud in the south is quite different from that in the north. In the north, the cloud has extended over the whole polar region beyond 55 N, whereas in the south the cloud has been confined to within about 10 degrees of the pole. The cloud in the north has had the form of a uniform hood, whereas the southern cloud has been much more complex. A map from December 2014,recorded by the Composite Infrared Spectrometer (CIRS) on Cassini, showed the 220 cm-1 emission coming from a distinct ring with a maximum at about 80 S. In contrast, emissions from the gases HC3N, C4H2 and C6H6 peaked near the pole and had a ring at 70 S. The 220 cm-1 ring at 80 S coincided with the minimum in the gas emission pattern. The80 S condensate ring encompassed the vortex cloud seen by the Cassini Imaging Science Subsystem (ISS) and Visible and Infrared Mapping Spectrometer (VIMS)[3, 4]. Both the 220 cm-1 ring and the gas "bull's-eye" pattern were centered on a point that was shifted from the geographic South Pole by 4 degrees in the direction of the Sun. This corresponds to the overall tilt of Titan's atmosphere discovered from temperature maps early in the Cassini mission by Achterberg et al. [5]. The tilt may be reinforced by the presumably twice-yearly (north and south) spin-up of the atmosphere at the autumnal pole. The bull's-eye pattern of the gas emissions can be explained by the retrieved abundance distributions, which are maximum near the pole and decrease sharply toward lower latitudes, together with temperatures that are minimum at the pole and increase toward lower latitudes

  8. Rb-Sr studies of CI and CM chondrites

    NASA Technical Reports Server (NTRS)

    Mittlefehldt, D. W.; Wetherill, G. W.

    1979-01-01

    Rb-Sr whole rock analyses have been performed on 2 CI and 3 CM chondrites. Four of these stones (Ivuna, Orgueil, Cold Bokkeveld and Erakot) were previously studied in this laboratory and were shown to be discordant from a 4.6 Gyr isochron. The fifth, Murchison, was not previously studied. The new data support the discordance of the first four stones, and indicate that Murchison is also discordant. Studies of Sr isotope ratios in unspiked Orgueil show that the discordance is not due to inhomogeneities in the Sr-84/Sr-86 ratio caused by incomplete mixing of nucleosynthesis products. In order to gauge the effects of weathering, two leaching experiments were performed on fresh, interior samples of Murchison; one for a period of 1.5 hr and the other for 117 hr. The results indicate that the relative solubility of nonradiogenic Sr is approximately twice that of Rb and radiogenic Sr is more soluble than the nonradiogenic Sr.

  9. The Murchison Widefield Array 21 cm Power Spectrum Analysis Methodology

    NASA Astrophysics Data System (ADS)

    Jacobs, Daniel C.; Hazelton, B. J.; Trott, C. M.; Dillon, Joshua S.; Pindor, B.; Sullivan, I. S.; Pober, J. C.; Barry, N.; Beardsley, A. P.; Bernardi, G.; Bowman, Judd D.; Briggs, F.; Cappallo, R. J.; Carroll, P.; Corey, B. E.; de Oliveira-Costa, A.; Emrich, D.; Ewall-Wice, A.; Feng, L.; Gaensler, B. M.; Goeke, R.; Greenhill, L. J.; Hewitt, J. N.; Hurley-Walker, N.; Johnston-Hollitt, M.; Kaplan, D. L.; Kasper, J. C.; Kim, HS; Kratzenberg, E.; Lenc, E.; Line, J.; Loeb, A.; Lonsdale, C. J.; Lynch, M. J.; McKinley, B.; McWhirter, S. R.; Mitchell, D. A.; Morales, M. F.; Morgan, E.; Neben, A. R.; Thyagarajan, N.; Oberoi, D.; Offringa, A. R.; Ord, S. M.; Paul, S.; Prabu, T.; Procopio, P.; Riding, J.; Rogers, A. E. E.; Roshi, A.; Udaya Shankar, N.; Sethi, Shiv K.; Srivani, K. S.; Subrahmanyan, R.; Tegmark, M.; Tingay, S. J.; Waterson, M.; Wayth, R. B.; Webster, R. L.; Whitney, A. R.; Williams, A.; Williams, C. L.; Wu, C.; Wyithe, J. S. B.

    2016-07-01

    We present the 21 cm power spectrum analysis approach of the Murchison Widefield Array Epoch of Reionization project. In this paper, we compare the outputs of multiple pipelines for the purpose of validating statistical limits cosmological hydrogen at redshifts between 6 and 12. Multiple independent data calibration and reduction pipelines are used to make power spectrum limits on a fiducial night of data. Comparing the outputs of imaging and power spectrum stages highlights differences in calibration, foreground subtraction, and power spectrum calculation. The power spectra found using these different methods span a space defined by the various tradeoffs between speed, accuracy, and systematic control. Lessons learned from comparing the pipelines range from the algorithmic to the prosaically mundane; all demonstrate the many pitfalls of neglecting reproducibility. We briefly discuss the way these different methods attempt to handle the question of evaluating a significant detection in the presence of foregrounds.

  10. Viscoelastic hydrodynamic interactions and anomalous CM diffusion in polymer melts

    NASA Astrophysics Data System (ADS)

    Meyer, Hendrik

    We have recently discovered that anomalous center-of-mass (CM) diffusion occurring on intermediate time scales in polymer melts can be explained by the interplay of viscoelastic and hydrodynamic interactions (VHI). The theory has been solved for unentangled melts in 3D and 2D and excellent agreement between theory and simulation is found, also for alkanes with a force field optimized from neutron scattering. The physical mechanism considers that hydrodynamic interactions are not screened: they are time dependent because of increasing viscosity before the terminal relaxation time. The VHI are generally active in melts of any topology. They are most important at early times well before the terminal relaxation time and thus affect the nanosecond time range typically observable in dynamic neutron scattering experiments. We illustrate the effects with recent molecular dynamics simulations of linear, ring and star polymers. Work performed with A.N. Semenov and J. Farago.

  11. Direct thrust measurement of a 30-cm ion thruster

    NASA Technical Reports Server (NTRS)

    Banks, B.; Rawlin, V.; Weigand, A.; Walker, J.

    1975-01-01

    A direct thrust measurement of a 30-cm diameter ion thruster was accomplished by means of a laser interferometer thrust stand. The thruster was supported in a pendulum manner by three 3.65-m long wires. Electrical power was provided by means of 18 mercury filled pots. A movable 23-button planar probe rake was used to determine thrust loss due to ion beam divergence. Values of thrust, thrust loss due to ion beam divergence, and thrust loss due to multiple ionization were measured for ion beam currents ranging from 0.5 to 2.5 A. Measured thrust values indicate an accuracy of approximately 1% and are in good agreement with thrust values calculated by indirect measurements.

  12. Hollow cathode restartable 15 cm diameter ion thruster

    NASA Technical Reports Server (NTRS)

    Wilbur, P. J.

    1973-01-01

    The effects of substituting high perveance dished grids for low perveance flat ones on performance variables and plasma properties within a 15 cm modified SERT II thruster are discussed. Results suggest good performance may be achieved as an ion thruster is throttled if the screen grid transparency is decreased with propellant flow rate. Thruster startup tests, which employ a pulsed high voltage tickler electrode between the keeper and the cathode to initiate the discharge, are described. High startup reliability at cathode tip temperatures of about 500 C without excessive component wear over 2000 startup cycles is demonstrated. Testing of a single cusp magnetic field concept of discharge plasma containment is discussed. A theory which explains the observed behavior of the device is presented and proposed thruster modifications and future testing plans are discussed.

  13. HIBAYES: Global 21-cm Bayesian Monte-Carlo Model Fitting

    NASA Astrophysics Data System (ADS)

    Zwart, Jonathan T. L.; Price, Daniel; Bernardi, Gianni

    2016-06-01

    HIBAYES implements fully-Bayesian extraction of the sky-averaged (global) 21-cm signal from the Cosmic Dawn and Epoch of Reionization in the presence of foreground emission. User-defined likelihood and prior functions are called by the sampler PyMultiNest (ascl:1606.005) in order to jointly explore the full (signal plus foreground) posterior probability distribution and evaluate the Bayesian evidence for a given model. Implemented models, for simulation and fitting, include gaussians (HI signal) and polynomials (foregrounds). Some simple plotting and analysis tools are supplied. The code can be extended to other models (physical or empirical), to incorporate data from other experiments, or to use alternative Monte-Carlo sampling engines as required.

  14. Astronaut Risk Levels During Crew Module (CM) Land Landing

    NASA Technical Reports Server (NTRS)

    Lawrence, Charles; Carney, Kelly S.; Littell, Justin

    2007-01-01

    The NASA Engineering Safety Center (NESC) is investigating the merits of water and land landings for the crew exploration vehicle (CEV). The merits of these two options are being studied in terms of cost and risk to the astronauts, vehicle, support personnel, and general public. The objective of the present work is to determine the astronaut dynamic response index (DRI), which measures injury risks. Risks are determined for a range of vertical and horizontal landing velocities. A structural model of the crew module (CM) is developed and computational simulations are performed using a transient dynamic simulation analysis code (LS-DYNA) to determine acceleration profiles. Landing acceleration profiles are input in a human factors model that determines astronaut risk levels. Details of the modeling approach, the resulting accelerations, and astronaut risk levels are provided.

  15. Very Large Array observations of Uranus at 2. 0 cm

    SciTech Connect

    Berge, G.L.; Muhleman, D.O.; Linfield, R.P.

    1988-07-01

    Radio observations of Uranus obtained at 2.0 cm with the B configuration of the VLA during April 1985 are reported. The calibration and data-reduction procedures are described in detail, and the results are presented in tables, maps, and graphs and compared with IRIS 44-micron observations (Hanel et al., 1986). Features discussed include highest brightness centered on the pole rather than on the subearth point, a decrease in brightness temperature (by up to 9 K) at latitudes between -20 and -50 deg (well correlated with the IRIS data), and disk-center position (corrected for the observed radio asymmetry) in good agreement with that found on the basis of the outer contours of the image. 15 references.

  16. Cosmic (Super)String Constraints from 21 cm Radiation

    SciTech Connect

    Khatri, Rishi; Wandelt, Benjamin D.

    2008-03-07

    We calculate the contribution of cosmic strings arising from a phase transition in the early Universe, or cosmic superstrings arising from brane inflation, to the cosmic 21 cm power spectrum at redshifts z{>=}30. Future experiments can exploit this effect to constrain the cosmic string tension G{mu} and probe virtually the entire brane inflation model space allowed by current observations. Although current experiments with a collecting area of {approx}1 km{sup 2} will not provide any useful constraints, future experiments with a collecting area of 10{sup 4}-10{sup 6} km{sup 2} covering the cleanest 10% of the sky can, in principle, constrain cosmic strings with tension G{mu} > or approx. 10{sup -10}-10{sup -12} (superstring/phase transition mass scale >10{sup 13} GeV)

  17. Cosmic (Super)String Constraints from 21 cm Radiation.

    PubMed

    Khatri, Rishi; Wandelt, Benjamin D

    2008-03-01

    We calculate the contribution of cosmic strings arising from a phase transition in the early Universe, or cosmic superstrings arising from brane inflation, to the cosmic 21 cm power spectrum at redshifts z > or =30. Future experiments can exploit this effect to constrain the cosmic string tension G mu and probe virtually the entire brane inflation model space allowed by current observations. Although current experiments with a collecting area of approximately 1 km2 will not provide any useful constraints, future experiments with a collecting area of 10(4)-10(6) km2 covering the cleanest 10% of the sky can, in principle, constrain cosmic strings with tension G mu > or = 10(-10)-10(-12) (superstring/phase transition mass scale >10(13) GeV). PMID:18352691

  18. Direct thrust measurement of a 30-cm ion thruster

    NASA Technical Reports Server (NTRS)

    Banks, B.; Rawlin, V.; Weigand, A. J.; Walker, J.

    1975-01-01

    A direct thrust measurement of a 30-cm diameter ion thruster was accomplished by means of a laser interferometer thrust stand. The thruster was supported in a pendulum manner by three 3.65-m long wires. Electrical power was provided by means of 18 mercury filled pots. A movable 23-button planar probe rake was used to determine thrust loss due to ion beam divergence. Values of thrust, thrust loss due to ion beam divergence, and thrust loss due to multiple ionization were measured for ion beam currents ranging from 0.5 A to 2.5 A. Measured thrust values indicate an accuracy of approximately 1% and are in good agreement with thrust values calculated by indirect measurements.

  19. A dual frequency 10 cm Doppler weather radar

    NASA Astrophysics Data System (ADS)

    Glover, K. M.; Armstrong, G. M.; Bishop, A. W.; Banis, K. J.

    A summary is given of the design concepts underlying a new 10-cm band dual frequency Doppler weather radar under development at the Air Force Geophysics Laboratory. Primary emphasis in the design is placed on the system performance in a clutter environment, and the technique used to extend the radar's unambiguous range and velocity span is an important, but secondary, consideration. The design includes the use of fault tolerance and/or fault location methods at critical locations in the system and automated calibration techniques for quasi-continuous monitoring of system performance. The approach followed for minimizing range and velocity ambiguities used in this radar is a uniform pulse train version of the Doviak et al. (1978) dual sampling (batch) technique.

  20. Performance tests for the NASA Ames Research Center 20 cm x 40 cm oscillating flow wind tunnel

    NASA Technical Reports Server (NTRS)

    Cook, W. J.; Giddings, T. A.

    1984-01-01

    An evaluation is presented of initial tests conducted to assess the performance of the NASA Ames 20 cm x 40 cm oscillating flow wind tunnel. The features of the tunnel are described and two aspects of tunnel operation are discussed. The first is an assessment of the steady mainstream and boundary layer flows and the second deals with oscillating mainstream and boundary layer flows. Experimental results indicate that in steady flow the test section mainstream velocity is uniform in the flow direction and in cross section. The freestream turbulence intensity is about 0.2 percent. With minor exceptions the steady turbulent boundary layer generated on the top wall of the test section exhibits the characteristics of a zero pressure gradient turbulent boundary layer generated on a flat plate. The tunnel was designed to generate sinusoidal oscillating mainstream flows. Experiments confirm that the tunnel produces sinusoidal mainstream velocity variations for the range of frequencies (up to 15 Hz). The results of this study demonstrate that the tunnel essentially produces the flows that it was designed to produce.

  1. Transport of E. coli in a sandy soil as impacted by depth to water table.

    PubMed

    Stall, Christopher; Amoozegar, Aziz; Lindbo, David; Graves, Alexandria; Rashash, Diana

    2014-01-01

    Septic systems are considered a source of groundwater contamination. In the study described in this article, the fate of microbes applied to a sandy loam soil from North Carolina coastal plain as impacted by water table depth was studied. Soil materials were packed to a depth of 65 cm in 17 columns (15-cm diameter), and a water table was established at 30, 45, and 60 cm depths using five replications. Each day, 200 mL of an artificial septic tank effluent inoculated with E. coli were applied to the top of each column, a 100-mL sample was collected at the water table level and analyzed for E. coli, and 100 mL was drained from the bottom to maintain the water table. Two columns were used as control and received 200 mL/day of sterilized effluent. Neither 30 nor 45 cm of unsaturated soil was adequate to attenuate bacterial contamination, while 60 cm of separation appeared to be sufficient. Little bacterial contamination moved with the water table when it was lowered from 30 to 60 cm.

  2. Root carbon decomposition and microbial biomass response at different soil depths

    NASA Astrophysics Data System (ADS)

    Rumpel, C.

    2012-12-01

    The relationship between root litter addition and soil organic matter (SOM) formation in top- versus subsoils is unknown. The aim of this study was to investigate root litter decomposition and stabilisation in relation to microbial parameters in different soil depths. Our conceptual approach included incubation of 13C-labelled wheat roots at 30, 60 and 90 cm soil depth for 36 months under field conditions. Quantitative root carbon contribution to SOM was assessed, changes of bulk root chemistry studied by solid-state 13C NMR spectroscopy and lignin content and composition was assessed after CuO oxidation. Compound-specific isotope analysis allowed to assess the role of root lignin for soil C storage in the different soil depths. Microbial biomass and community structure was determined after DNA extraction. After three years of incubation, O-alkyl C most likely assigned to polysaccharides decreased in all soil depth compared to the initial root material. The degree of root litter decomposition assessed by the alkyl/O-alkyl ratio decreased with increasing soil depth, while aryl/O-alkyl ratio was highest at 60 cm depth. Root-derived lignin showed depth specific concentrations (30 < 90 < 60 cm). Its composition was soil depth independent suggesting that microbial communities in all three soil depths had similar degradation abilities. Microbial biomass C and fungi contribution increased after root litter addition. Their community structure changed after root litter addition and showed horizon specific dynamics. Our study shows that root litter addition can contribute to C storage in subsoils but did not influence C storage in topsoil. We conclude that specific conditions of single soil horizons have to be taken into account if root C dynamics are to be fully understood.

  3. Effects of SrRuO{sub 3} buffer layer thickness on multiferroic (Bi{sub 0.90}La{sub 0.10})(Fe{sub 0.95}Mn{sub 0.05})O{sub 3} thin films

    SciTech Connect

    Wu Jiagang; Wang, John

    2009-09-01

    Multiferroic (Bi{sub 0.90}La{sub 0.10})(Fe{sub 0.95}Mn{sub 0.05})O{sub 3} (BLFMO) thin films were deposited on SrRuO{sub 3} (SRO) buffered Pt/TiO{sub 2}/SiO{sub 2}/Si(100) substrates with variable buffer layer thicknesses by using off-axis radio frequency sputtering. The orientation of BLFMO thin films is dependent on the SRO buffer layer thickness, which leads to a change in ferroelectric behavior. Due to the low leakage currents arising from the orientation change in association with the variation in SRO buffer layer thickness and the La and Mn codoping, well saturated P-E hysteresis loops (2P{sub r}approx210.0 muC/cm{sup 2} and 2E{sub c}approx525.5 kV/cm) are shown for the (111)-oriented BLFMO thin film at room temperature and 1 kHz. It also demonstrates little ferroelectric fatigue on 10{sup 9} switching cycles. Moreover, the BLFMO thin film exhibits the enhanced magnetic behavior as compared to pure BFO thin films, due to the canting of antiferromagnetically ordered spins.

  4. Miscanthus-derived SOC: numerically declining over soil depths

    NASA Astrophysics Data System (ADS)

    Hu, Yaxian; Schäfer, Gerhard; Duplay, Joëlle; Kuhn, Nikolaus J.

    2016-04-01

    Miscanthus is one of the most efficient perennial bioenergy crops for wide establishment and distribution. Most of the previous reports had shown the benefits of Miscanthus cultivation in soil organic carbon (SOC) sequestration and greenhouse gas emissions (GHG) mitigation. However, some other papers pointed out that the Miscanthus-derived SOC is mainly of particulate organic matter and the labile quality of particulate organic matter may bear great uncertainties in GHGs emissions. This urges the necessity to investigate the quality and mineralization potential of Miscanthus-derived SOC. This study investigated soil profiles deep to 1 m from 20 yr Miscanthus fields in France and Switzerland. Soil organic carbon (SOC) concentration and δ13C compositions of all the soil layers (0-10, 10-40, 40-70 and 70-100 cm) were determined. Our results show that: 1) Miscanthus cultivation can in general increase the SOC stocks compared to the Grassland, while the benefits of SOC sequestration may only constrain to the surface soil. Isotopically, the Miscanthus-derived SOC ranged from 69% the top 10 cm soil down to only 7% in the 70 to 100 cm layer, cautioning the use of SOC stocks on the surface soil to estimate the total net benefits of Miscanthus cultivation in terms of sequestrating atmospheric CO2. 2) Compared to the Grassland soils, the surface soils on the Miscanthus fields tended to have a risk of acidification (pH values down to 6) and exceeded contents of P and K, adding another precaution to the environmental impacts of Miscanthus cultivation in the entire Upper Rhine Region. Overall, changes of soil characteristics must be included into Life Cycle Assessment to fully evaluate the environmental impacts of long-term Miscanthus cultivation.

  5. Liquid Argon Maximm Convective Heat Flux vs. Liquid Depth

    SciTech Connect

    Peterson, T.; /Fermilab

    1990-01-12

    In order to help answer questions about the magnitude of heat flux to the liquid argon in a liquid argon calorimeter which could cause boiling (bubbles), calculations estimating the heat flux which can be removed by free convection were made in February, 1988. These calculations are intended to be an estimate of the heat flux above which boiling would occur. No formal writeup was made of these calculations, although the graph dated 3 Feb 88 and revised (adding low-velocity forced convection lines) 19 Feb 88 was presented in several meetings and widely distributed. With this description of the calculations, copies of the original graph and calculations are being added to the D0 Engineering Note files. The liquid argon surface is in equilibrium with argon vapor at a pressure of 1.3 bar, so the surface is at 89.70 K. The liquid is entirely at this surface temperature throughout the bulk of the volume, except locally where it is warmed by a solid surface at a higher temperature than the bulk liquid. This surface temperature is taken to be the boiling temperature of argon at the pressure corresponding to 1.3 bar plus the liquid head; hence it is a function of depth below the surface. The free and forced convection correlations used are 'from Kreith, 'Heat Transfer', for heated flat plates in a large (i.e., no other objects nearby enough to disturb the flow) uniform volume of fluid. Heat flux is a function of plate size, really length along the flow path (since a boundary layer increases in thickness starting from the leading edge of the plate), and orientation (i.e., vertical or horizontal). The maximum heat flux which can be carried away by free convection (i.e., the heat flux above which boiling occurs) is .001 W/sq.cm. at 4 inches below the surface and 0.1 to 0.2 W/sq.cm. 15 feet below the surface. Forced convection over a 1 cm plate with a fluid velocity of 1 cm/sec, or a 10 cm plate at 10 cm/sec, is about like free convection. The line for much higher heat flux is

  6. Investigation of a new lead-free Bi0.5(Na0.40K0.10)TiO3-(Ba0.7Sr0.3)TiO3 piezoelectric ceramic

    PubMed Central

    2012-01-01

    Lead-free piezoelectric compositions of the (1-x)Bi0.5(Na0.40K0.10)TiO3-x(Ba0.7Sr0.3)TiO3 system (when x = 0, 0.05, 0.10, 0.15, and 0.20) were fabricated using a solid-state mixed oxide method and sintered between 1,050°C and 1,175°C for 2 h. The effect of (Ba0.7Sr0.3)TiO3 [BST] content on phase, microstructure, and electrical properties was investigated. The optimum sintering temperature was 1,125°C at which all compositions had densities of at least 98% of their theoretical values. X-ray diffraction patterns that showed tetragonality were increased with the increasing BST. Scanning electron micrographs showed a slight reduction of grain size when BST was added. The addition of BST was also found to improve the dielectric and piezoelectric properties of the BNKT ceramic. A large room-temperature dielectric constant, εr (1,609), and piezoelectric coefficient, d33 (214 pC/N), were obtained at an optimal composition of x = 0.10. PMID:22221833

  7. Mechanisms and depths of atlantic transform earthquakes

    NASA Technical Reports Server (NTRS)

    Engeln, J. F.; Wiens, D. A.; Stein, S.

    1986-01-01

    Mechanisms and depths of 40 earthquakes on major transforms along the Mid-Atlantic Ridge are studied in order to identify events that deviate from the transform-parallel strike-slip motion. Long and short period waves and Rayleigh wave spectral amplitudes are used to analyze focal mechanisms, depths, source time functions, and seismic moments of earthquakes. The relationship between centroid depths and transform thermal structures is examined. The data reveal that transform earthquake centroid depths occur above the predicted 400 C isotherms and the oceanic intraplate depths extend to the 750 C isotherm. Slip rates inferred from seismic moment releases are compared to those predicted by plate motions and good correlation is detected. The difference in the centroid depths of transform and interplate seismicity indicates transforms are either weaker or higher temperatures than expected.

  8. Learning the missing values in depth maps

    NASA Astrophysics Data System (ADS)

    Yin, Xuanwu; Wang, Guijin; Zhang, Chun; Liao, Qingmin

    2013-12-01

    In this paper, we consider the task of hole filling in depth maps, with the help of an associated color image. We take a supervised learning approach to solve this problem. The model is learnt from the training set, which contain pixels that have depth values. Then we apply supervised learning to predict the depth values in the holes. Our model uses a regional Markov Random Field (MRF) that incorporates multiscale absolute and relative features (computed from the color image), and models depths not only at individual points but also between adjacent points. The experiments show that the proposed approach is able to recover fairly accurate depth values and achieve a high quality depth map.

  9. Neutron depth profiling at the University of Texas

    NASA Astrophysics Data System (ADS)

    Ünlü, Kenan; Wehring, Bernard W.

    1994-12-01

    A Neutron Depth Profiling (NDP) facility has been developed at The University of Texas at Austin (UT) Nuclear Engineering Teaching Laboratory. Thermal neutrons from the tangential beam port of the UT 1-MW TRIGA Mark II research reactor are utilized. The UT-NDP facility consists of a neutron beam collimator, target chamber, beam catcher, and necessary data acquisition and process electronics. The collimator was designed to achieve a high quality thermal neutron beam with good intensity and minimum contamination of neutrons above thermal energies. A target chamber for NDP was constructed from 40.6 cm diameter aluminum tubing. The chamber can accommodate several small samples as well as a single large sample with a diameter up to 30.5 cm. Depth profiles for borophosphosilicate glass films on silicon wafers were measured using the UT-NDP facility. Other potential applications of the UT-NDP facility include the study of implanted boron in semiconductor material; study of nitrogen in metals; and study of helium behavior in metals, and metallic and amorphous alloys.

  10. The effect of burial depth on removal of seeds of Phytolacca americana.

    SciTech Connect

    Orrock, John, L.: Damschen, Ellen, I.

    2007-04-01

    Abstract - Although burial is known to have important effects on seed predation in a variety of habitats, the role of burial depth in affecting the removal of seeds in early successional systems is poorly known. Phytolacca American (pokeweed) is a model species to examine the role of burial depth in affecting seed removal because it is common in early-successional habitats, studies suggest that seed removal is indicative of seed predation, and seed predation is related to the recruitment of mature plants. To determine how burial depth affects P. americana seed removal, 20 seeds of P. americana were buried at depths of 0, 1, or 3 cm in early-successional habitats at the Savannah River Site in South Carolina for over 6 weeks. The frequency with which seeds were encountered (as measured by the removal of at least one seed) and the proportion of seeds removed was significantly greater when seeds were on the soil surface (0 cm depth) compared to seeds that were buried 1 cm or 3 cm; there was no difference in encounter or removal between seeds at 1 cm or 3 cm. Our findings suggest that burial may have important consequences for P. americana population dynamics, because seed survival depends upon whether or not the seed is buried, and relatively shallow burial can yield large increases in seed survival. Because seed limitation is known to be an important determinant of plant community composition in early successional systems, our work suggests that burial may play an unappreciated role in the dynamics of these communities by reducing predator-mediated seed limitation.

  11. A 1.3 cm line survey toward IRC +10216

    NASA Astrophysics Data System (ADS)

    Gong, Y.; Henkel, C.; Spezzano, S.; Thorwirth, S.; Menten, K. M.; Wyrowski, F.; Mao, R. Q.; Klein, B.

    2015-02-01

    Context. IRC +10216 is the prototypical carbon star exhibiting an extended molecular circumstellar envelope. Its spectral properties are therefore the template for an entire class of objects. Aims: The main goal is to systematically study the λ ~ 1.3 cm spectral line characteristics of IRC +10216. Methods: We carried out a spectral line survey with the Effelsberg-100 m telescope toward IRC +10216. It covers the frequency range between 17.8 GHz and 26.3 GHz (K-band). Results: In the circumstellar shell of IRC +10216, we find 78 spectral lines, among which 12 remain unidentified. The identified lines are assigned to 18 different molecules and radicals. A total of 23 lines from species known to exist in this envelope are detected for the first time outside the solar system and there are additional 20 lines first detected in IRC +10216. The potential orgin of "U" lines is also discussed. Assuming local thermodynamic equilibrium (LTE), we then determine rotational temperatures and column densities of 17 detected molecules. Molecular abundances relative to H2 are also estimated. A non-LTE analysis of NH3 shows that the bulk of its emission arises from the inner envelope with a kinetic temperature of 70 ± 20 K. Evidence for NH3 emitting gas with higher kinetic temperature is also obtained, and potential abundance differences between various 13C-bearing isotopologues of HC5N are evaluated. Overall, the isotopic 12C/13C ratio is estimated to be 49 ± 9. Finally, a comparison of detected molecules in the λ ~ 1.3 cm range with the dark cloud TMC-1 indicates that silicate-bearing molecules are more predominant in IRC +10216. Appendices are available in electronic form at http://www.aanda.orgSpectra as FITS files are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/574/A56

  12. Amorphous nanostructuralization in HOPG by 1014 W cm-2 laser

    NASA Astrophysics Data System (ADS)

    NISHIMURA, Yasuhiko; KITAGAWA, Yoneyoshi; MORI, Yoshitaka; ISHII, Katsuhiro; HANAYAMA, Ryohei; AZUMA, Hirozumi; HIOKI, Tatsumi; NISHI, Teppei; MOTOHIRO, Tomoyoshi; KOMEDA, Osamu; SEKINE, Takashi; SATO, Nakahiro; KURITA, Takashi; KAWASHIMA, Toshiyuki; KAN, Hirofumi; SUNAHARA, Atsushi; SENTOKU, Yasuhiko; MIURA, Eisuke

    2016-05-01

    This reports provide an amorphous nanostructuralization technique on the surface modification in Highly Oriented Pyrolytic Graphite (HOPG) by using a femtosecond laser. We showed, for the first time, that the surface of HOPG is changed to the amorphous nanostructuralization graphite by using a femtosecond laser-driven compression technique. Our results also suggest that the HOPG surface is changed until the deeper area from the surface by the laser-driven shock wave. A single shot of a femtosecond laser beam (1.27 ∼ 1.33×1014 Wcm∼2 in intensity, with 2 mm-diameter, and 110 fs in pulse width) is irradiated under the vacuum ambience onto a 2 mm-thick of HOPG. The calculated impact pressures on a sample was 8.3 ∼ 8.7 GPa. Crystal structure in the HOPG were analyzed using a Raman spectroscopy and an X-ray diffraction, those analyzing depth from the surface were 50 nm and 350 μm, respectively.

  13. Clear sky atmosphere at cm-wavelengths from climatology data

    NASA Astrophysics Data System (ADS)

    Lew, Bartosz; Uscka-Kowalkowska, Joanna

    2016-01-01

    We utilize ground-based, balloon-borne and satellite climatology data to reconstruct site and season-dependent vertical profiles of precipitable water vapour (PWV). We use these profiles to solve radiative transfer through the atmosphere, and derive atmospheric brightness temperature (Tatm) and optical depth (τ) at centimetre wavelengths. We validate the reconstruction by comparing the model column PWV with photometric measurements of PWV, performed in clear sky conditions pointed towards the Sun. Based on the measurements, we devise a selection criteria to filter the climatology data to match the PWV levels to the expectations of the clear sky conditions. We apply the reconstruction to the location of a Polish 32-metre radio telescope, and characterize Tatm and τ year round, at selected frequencies. We also derive the zenith distance dependence for these parameters, and discuss the shortcomings of using planar, single-layer and optically thin atmospheric models in continuum radio-source flux-density measurement calibrations. We obtain PWV-Tatm and PWV-τ scaling relations in clear sky conditions, and constrain limits to which the actual Tatm and τ can deviate from those derived solely from the climatological data. Finally, we suggest a statistical method to detect clear sky that involves ground-level measurements of relative humidity. Accuracy is tested using local climatological data. The method may be useful to constrain cloud cover in cases when no other (and more robust) climatological data are available.

  14. Are face representations depth cue invariant?

    PubMed

    Dehmoobadsharifabadi, Armita; Farivar, Reza

    2016-06-01

    The visual system can process three-dimensional depth cues defining surfaces of objects, but it is unclear whether such information contributes to complex object recognition, including face recognition. The processing of different depth cues involves both dorsal and ventral visual pathways. We investigated whether facial surfaces defined by individual depth cues resulted in meaningful face representations-representations that maintain the relationship between the population of faces as defined in a multidimensional face space. We measured face identity aftereffects for facial surfaces defined by individual depth cues (Experiments 1 and 2) and tested whether the aftereffect transfers across depth cues (Experiments 3 and 4). Facial surfaces and their morphs to the average face were defined purely by one of shading, texture, motion, or binocular disparity. We obtained identification thresholds for matched (matched identity between adapting and test stimuli), non-matched (non-matched identity between adapting and test stimuli), and no-adaptation (showing only the test stimuli) conditions for each cue and across different depth cues. We found robust face identity aftereffect in both experiments. Our results suggest that depth cues do contribute to forming meaningful face representations that are depth cue invariant. Depth cue invariance would require integration of information across different areas and different pathways for object recognition, and this in turn has important implications for cortical models of visual object recognition. PMID:27271993

  15. Pictorial depth probed through relative sizes

    PubMed Central

    Wagemans, Johan; van Doorn, Andrea J; Koenderink, Jan J

    2011-01-01

    In the physical environment familiar size is an effective depth cue because the distance from the eye to an object equals the ratio of its physical size to its angular extent in the visual field. Such simple geometrical relations do not apply to pictorial space, since the eye itself is not in pictorial space, and consequently the notion “distance from the eye” is meaningless. Nevertheless, relative size in the picture plane is often used by visual artists to suggest depth differences. The depth domain has no natural origin, nor a natural unit; thus only ratios of depth differences could have an invariant significance. We investigate whether the pictorial relative size cue yields coherent depth structures in pictorial spaces. Specifically, we measure the depth differences for all pairs of points in a 20-point configuration in pictorial space, and we account for these observations through 19 independent parameters (the depths of the points modulo an arbitrary offset), with no meaningful residuals. We discuss a simple formal framework that allows one to handle individual differences. We also compare the depth scale obtained by way of this method with depth scales obtained in totally different ways, finding generally good agreement. PMID:23145258

  16. Clutter depth discrimination using the wavenumber spectrum.

    PubMed

    Benjamin Reeder, D

    2014-01-01

    Clutter depth is a key parameter in mid-frequency active sonar systems to discriminate between sources of clutter and targets of interest. A method is needed to remotely discriminate clutter depth by information contained in the backscattered signal-without a priori knowledge of that depth. Presented here is an efficient approach for clutter depth estimation using the structure in the wavenumber spectrum. Based on numerical simulations for a simple test case in a shallow water waveguide, this technique demonstrates the potential capability to discriminate between a clutter source in the water column vs one on the seabed.

  17. Depth Perception In Remote Stereoscopic Viewing Systems

    NASA Technical Reports Server (NTRS)

    Diner, Daniel B.; Von Sydow, Marika

    1989-01-01

    Report describes theoretical and experimental studies of perception of depth by human operators through stereoscopic video systems. Purpose of such studies to optimize dual-camera configurations used to view workspaces of remote manipulators at distances of 1 to 3 m from cameras. According to analysis, static stereoscopic depth distortion decreased, without decreasing stereoscopitc depth resolution, by increasing camera-to-object and intercamera distances and camera focal length. Further predicts dynamic stereoscopic depth distortion reduced by rotating cameras around center of circle passing through point of convergence of viewing axes and first nodal points of two camera lenses.

  18. An Exploration of the Needling Depth in Acupuncture: The Safe Needling Depth and the Needling Depth of Clinical Efficacy

    PubMed Central

    Lin, Jaung-Geng; Chou, Pei-Chi; Chu, Heng-Yi

    2013-01-01

    Objective. To explore the existing scientific information regarding safe needling depth of acupuncture points and the needling depth of clinical efficacy. Methods. We searched the PubMed, EMBASE, Cochrane, Allied and Complementary Medicine (AMED), The National Center for Complementary and Alternative Medicine (NCCAM), and China National Knowledge Infrastructure (CNKI) databases to identify relevant monographs and related references from 1991 to 2013. Chinese journals and theses/dissertations were hand searched. Results. 47 studies were recruited and divided into 6 groups by measuring tools, that is, MRI, in vivo evaluation, CT, ultrasound, dissected specimen of cadavers, and another group with clinical efficacy. Each research was analyzed for study design, definition of safe depth, and factors that would affect the measured depths. Depths of clinical efficacy were discussed from the perspective of de-qi and other clinical observations. Conclusions. Great inconsistency in depth of each point measured from different subject groups and tools exists. The definition of safe depth should be established through standardization. There is also lack of researches to compare the clinical efficacy. A well-designed clinical trial selecting proper measuring tools to decide the actual and advisable needling depth for each point, to avoid adverse effects or complications and promote optimal clinical efficacy, is a top priority. PMID:23935678

  19. Conjugate 18 cm OH satellite lines at a cosmological distance.

    PubMed

    Kanekar, Nissim; Chengalur, Jayaram N; Ghosh, Tapasi

    2004-07-30

    We have detected the two 18 cm OH satellite lines from the z approximately 0.247 source PKS1413+135, the 1720 MHz line in emission and the 1612 MHz line in absorption. The 1720 MHz luminosity is L(OH) approximately 354L (center dot in circle), more than an order of magnitude larger than that of any other known 1720 MHz maser. The profiles of the two satellite lines are conjugate, implying that they arise in the same gas. This allows us to test for any changes in the values of fundamental constants without being affected by systematic uncertainties arising from relative motions between the gas clouds in which the different lines arise. Our data constrain changes in G identical with g(p)[alpha(2)/y](1.849), where y identical with m(e)/m(p); we find DeltaG/G=2.2+/-3.8 x 10(-5), consistent with no changes in alpha, g(p), and y.

  20. Piezo-Operated Shutter Mechanism Moves 1.5 cm

    NASA Technical Reports Server (NTRS)

    Glaser, Robert; Bamford, Robert

    2005-01-01

    The figure shows parts of a shutter mechanism designed to satisfy a number of requirements specific to its original intended application as a component of an atomic clock to be flown in outer space. The mechanism may also be suitable for use in laboratory and industrial vacuum systems on Earth for which there are similar requirements. The requirements include the following: a) To alternately close, then open, a 1.5-cm-diameter optical aperture twice per second, with a stroke time of no more than 15 ms, during a total operational lifetime of at least a year; b) To attenuate light by a factor of at least 1012 when in the closed position; c) To generate little or no magnetic field; d) To be capable of withstanding bakeout at a temperature of 200 C to minimize outgassing during subsequent operation in an ultrahigh vacuum; and e) To fit within a diameter of 12 in. (=305 mm) a size limit dictated by the size of an associated magnetic shield. The light-attenuation requirement is satisfied by use of overlapping shutter blades. The closure of the aperture involves, among other things, insertion of a single shutter blade between a pair of shutter blades. The requirement to minimize the magnetic field is satisfied by use of piezoelectric actuators. Because piezoelectric actuators cannot withstand bakeout, they must be mounted outside the vacuum chamber, and, hence, motion must be transmitted from the actuators to the shutter levers via a vacuum-chamber-wall diaphragm.

  1. Microbiological study of the Murchison CM2 meteorite

    NASA Astrophysics Data System (ADS)

    Pikuta, Elena V.; Hoover, Richard B.

    2012-10-01

    In 1864, Louis Pasteur attempted to cultivate living microorganisms from pristine samples of the Orgueil CI1 carbonaceous meteorite. His results were negative and never published, but recorded it in his laboratory notebooks. At that time, only aerobic liquid or agar-based organic reach media were used, as his research on anaerobes had just started. In our laboratory the Murchison CM2 carbonaceous meteorite was selected to expand on these studies for microbiological study by cultivation on anaerobic mineral media. Since the surface could have been more easily contaminated, interior fragments of a sample of the Murchison meteorite were extracted and crushed under sterile conditions. The resulting powder was then mixed in anoxic medium and injected into Hungate tubes containing anaerobic media with various growth substrates at different pH and salinity and incubated at different temperatures. The goal of the experiments was to determine if living cells would grow from the material of freshly fractured interior fragments of the stone. If any growth occurred, work could then be carried out to assess the nature of the environmental contamination by observations of the culture growth (rates of speed and biodiversity); live/dead fluorescent staining to determine contamination level and DNA analysis to establish the microbial species present. In this paper we report the results of that study.

  2. Sensing and characterization of explosive vapors near 700 cm -1

    NASA Astrophysics Data System (ADS)

    Ford, Alan R.; Reeve, Scott W.

    2007-04-01

    One of the technological challenges associated with trace vapor detection of explosive materials are the relatively low vapor pressures exhibited by most energetic materials under ambient conditions. For example, the vapor pressure for TNT is ~10 ppbv at room temperature, a concentration near the Limit of Detection for many of the technologies currently being deployed. In the case of improvised explosive devices, the clandestine nature of the device further serves to exacerbate the vapor pressure issue. Interestingly, the gold standard in explosives detection remains the trained canine nose. While there is still some debate as to what the dog actually smells, recent studies have indicated the alert response is triggered, not by the vapor presence of a specific explosive compound but, by a characteristic bouquet of odors from chemical impurities used to manufacture and process the explosives. Here we present high resolution infrared data for several of these volatile organic compounds in the 700 cm -1 region required for real time optical sensing of energetic materials.

  3. CM and DM in an ISO R and D Environment

    NASA Technical Reports Server (NTRS)

    Crowley, Sandra L.

    2000-01-01

    ISO 9000 - a common buzz word in industry is making inroads to government agencies. The National Aeronautics and Space Agency (NASA) achieved ISO 9001 certification at each of its nine (9) Centers and Headquarters in 1998-1999. NASA Glenn Research Center (GRC) was recommended for certification in September 1999. Since then, each of the Centers has been going through the semi-annual surveillance audits. Growing out of the manufacturing industry, successful application of the international quality standard to a research and development (R&D) environment has had its challenges. This paper will address how GRC applied Configuration Management (CM) and Data (or Document) Management (DM) to meet challenges to achieve ISO certification. One of the first challenges was to fit the ISO 9001-1994 elements to the GRC environment. Some of the elements fit well-Management Responsibility (4.1), Internal Audits (4.17), Document and Data Control (4.5). Other elements were not suited or applied easily to the R&D environment-Servicing (4.19), Statistical Techniques (4.20). Since GRC "builds" only one or two items at a time, these elements were considered not applicable to the environment.

  4. Ion thruster system (8-cm) cyclic endurance test

    NASA Technical Reports Server (NTRS)

    Dulgeroff, C. R.; Beattie, J. R.; Poeschel, R. L.; Hyman, J., Jr.

    1984-01-01

    This report describes the qualification test of an Engineering-Model 5-mN-thrust 8-cm-diameter mercury ion thruster which is representative of the Ion Auxiliary Propulsion System (IAPS) thrusters. Two of these thrusters are scheduled for future flight test. The cyclic endurance test described herein was a ground-based test performed in a vacuum facility with a liquid-nitrogen-cooled cryo-surface and a frozen mercury target. The Power Electronics Unit, Beam Shield, Gimal, and Propellant Tank that were used with the thruster in the endurance test are also similar to those of the IAPS. The IAPS thruster that will undergo the longest beam-on-time during the actual space test will be subjected to 7,055 hours of beam-on-time and 2,557 cycles during the flight test. The endurance test was successfully concluded when the mercury in the IAPS Propellant Tank was consumed. At that time, 8,471 hours of beam-on-time and 599 cycles had been accumulated. Subsequent post-test-evaluation operations were performed (without breaking vacuum) which extended the test values to 652 cycles and 9,489 hours of beam-on-time. The Power Electronic Unit (PEU) and thruster were in the same vacuum chamber throughout the test. The PEU accumulated 10,268 hr of test time with high voltage applied to the operating thruster or dummy load.

  5. The 15 cm mercury ion thruster research 1975

    NASA Technical Reports Server (NTRS)

    Wilbur, P. J.

    1975-01-01

    Doubly charged ion current measurements in the beam of a SERT II thruster are shown to introduce corrections which bring its calculated thrust into close agreement with that measured during flight testing. A theoretical model of doubly charged ion production and loss in mercury electron bombardment thrusters is discussed and is shown to yield doubly-to-singly charged ion density ratios that agree with experimental measurements obtained on a 15 cm diameter thruster over a range of operating conditions. Single cusp magnetic field thruster operation is discussed and measured ion beam profiles, performance data, doubly charged ion densities, and discharge plasma characteristics are presented for a range of operating conditions and thruster geometries. Variations in the characteristics of this thruster are compared to those observed in the divergent field thruster and the cusped field thruster is shown to yield flatter ion beam profiles at about the same discharge power and propellant utilization operating point. An ion optics test program is described and the measured effects of grid system dimensions on ion beamlet half angle and diameter are examined. The effectiveness of hollow cathode startup using a thermionically emitting filament within the cathode is examined over a range of mercury flow rates and compared to results obtained with a high voltage tickler startup technique. Results of cathode plasma property measurement tests conducted within the cathode are presented.

  6. Effect of sediment depth and sediment type on the survival of Vallisneria americana Michx grown from tubers

    USGS Publications Warehouse

    Rybicki, N.B.; Carter, V.

    1986-01-01

    Sedimentation resulting from storms may have been one of the reasons for the elimination of submersed aquatic vegetation from the tidal Potomac River in the late 1930's. Laboratory studies were conducted to investigate the effects of different depths of overlying sediment and composition of sediment on the survival of Vallisneria americana Michx (wildcelery) grown from tubers. Survival of plants grown from tubers decreased significantly with increasing sediment depth. Survival of tubers declined from 90% or more when buried in 10 cm to no survival in greater than 25 cm of sediment. Survival with depth in sand was significantly lower than in silty clay. Field investigation determined that the majority of tubers in Vallisneria beds are distributed between 10 and 20 cm in depth in silty clay and between 5 and 15 cm in depth in sand. Based on the field distribution of tubers and on the percent survival of plants growing from tubers at each depth in the laboratory experiment, we suggest that the deposition of 10 cm or more of sediment by severe storms such as occurred in the 1930s could contribute to the loss of vegetation in the tidal Potomac River. ?? 1986.

  7. Value of leads V4R and CM5 in the detection of coronary artery disease during exercise electrocardiographic test.

    PubMed

    Puurtinen, Merja; Nieminen, Tuomo; Kähönen, Mika; Lehtimäki, Terho; Lehtinen, Rami; Nikus, Kjell; Hyttinen, Jari; Viik, Jari

    2010-07-01

    The usefulness of the right precordial unipolar leads and the value of the bipolar lead CM5 in the detection of coronary artery disease (CAD) with exercise electrocardiographic (ECG) test are not well documented. The objective of this study was to evaluate the diagnostic performance of leads V4R and CM5. The study population comprised 579 patients referred for a bicycle exercise ECG test in the Finnish Cardiovascular Study. Patients were divided into three groups: angiographically proven CAD (CAD, n = 255), no CAD by angiography (NoCAD, n = 126), and low likelihood of CAD (LLC, n = 198). The maximum ST-segment depression at peak exercise was used as a parameter, and the diagnostic accuracy of different leads was assessed by receiver operating characteristic (ROC) analysis. Sensitivity and specificity values at a cut-off criterion of -0.10 mV ST-segment, 1-mm ST depression, were determined. According to the results, incorporating lead V4R with the standard leads decreased the ROC area from 0.71 to 0.69 (comparison CAD versus LLC) and from 0.55 to 0.53 (comparison CAD versus NoCAD) and had no effect on sensitivity or specificity. Adding lead CM5 to the standard leads did not affect the ROC area but increased the sensitivity and decreased the specificity. In conclusion, the use of right precordial lead V4R along with the standard 12-lead system does not improve the performance of the exercise ECG in diagnosing CAD. Adding lead CM5 to the standard leads increases the sensitivity but does not change the overall diagnostic performance. PMID:20497446

  8. Stereotactic ablative radiotherapy in the treatment of hepatocellular carcinoma >3 cm.

    PubMed

    Guarneri, Alessia; Franco, Pierfrancesco; Trino, Elisabetta; Campion, Daniela; Faletti, Riccardo; Mirabella, Stefano; Gaia, Silvia; Ragona, Riccardo; Diotallevi, Margherita; Saracco, Giorgio; Salizzoni, Mauro; Ricardi, Umberto; Carucci, Patrizia

    2016-10-01

    Stereotactic ablative radiotherapy (SABR) is a safe treatment approach for hepatocellular carcinoma (HCC) with comparable results to other local therapies. For lesions larger than 3 cm, no definitive standard treatment is present and several options are available. We retrospectively review local control (LC) and survival results of SABR in patients with HCC lesions >3 cm. Between 2012 and 2015, we treated 29 patients (39 lesions) having histological or radiological diagnosis of HCC and at least one lesion sized >3 cm. Patients were prescribed 36-48 Gy in 3-5 fractions (mainly 16 Gy × 3 fractions or 8 Gy × 5 fractions), in 3-5 consecutive days. A total of 15 lesions (52 %) had complete, while 10 (34 %) had partial remission; 3 (11 %) had a stable disease. Mean time for CR achievement was 5.8 months (range 1-17). One- and two-year actuarial LC was 100 %. Moreover, 1- and 2-year progression-free (PFS), cancer-specific and overall survival were 57.9 % [standard error (SE) 0.09; 95 % CI 36.9-74.2] and 41.2 % (SE 0.12; 95 % CI 17.7-63.5), 80.7 % (SE 0.08; 95 % CI 59.6-91.5) and 63.3 % (SE 0.11; 95 % CI 38.4-80.3), 71.7 % (SE 0.08; 95 % CI 51.2-84.7) and 56.2 % (SE 0.10; 95 % CI 33.8-73.6). On multivariate analysis, achieving a CR within the target lesion had a borderline significance with respect to PFS (HR 0.83; SE = 0.014; z -1.15; p = 0.095; 95 % CI 0.71-7.45). Time between HCC diagnosis and SABR delivery (< vs >12 months) was significantly correlated with OS (HR 16.5; SE 21.5; z = 2.14; p = 0.032; 95 % CI 1.27-213.3) as CLIP score (score: 0-1 vs 2) (HR 5.6; SE 4.6; z = 2.10; p = 0.036; 95 % CI 1.11-27.8). A total of 6 major toxic events (G3-G4) were recorded (20 %). In 2 patients (6 %), a radiation-induced liver disease was seen. In conclusion, SABR provided LC and survival rates comparable to other local therapies for patients with HCC lesion sized >3 cm, with acceptable toxicity profile. PMID:27566310

  9. Trends in extend and depth of Ordovician infauna

    SciTech Connect

    Droser, M.L.; Bottjer, D.J.

    1987-05-01

    The Ordovician radiation has been particularly well documented from analyses of trends in marine familial diversity. Trace fossil diversity also increased during this time. However, there has not previously been an attempt to document the Ordovician radiation in terms of depth and extent of bioturbation and utilization of infaunal ecospace. In order to determine the relationship between the Ordovician radiation and the development of the infaunal biological benthic boundary layer, over 600 m of Ordovician strata (Nevada and Utah) deposited in shallow subtidal shelf environments were examined. The amount of bioturbation in these rocks was ranked using the following ichnofabric indices: (1) no bioturbation; (2) discrete isolated trace fossils, up to 10% bioturbated; (3) 10 to 40% bioturbated, but bedding is generally preserved; (4) 40 to 60% bioturbated, last vestiges of bedding preserved; (5) bedding completely disrupted; and (6) bedding nearly or totally homogenized. In the Lower and Middle Ordovician the most common ichnofabric index is 3, represented by 41% of the strata, whereas ichnofabric index 5 represents only 8%. Depth of bioturbation averages 2-3 cm with a maximum of 5 cm. Flat pebble conglomerates, previously suggested to indicate limited bioturbation, are abundant in these strata. By the late Caradoc, 67% of the strata are represented by ichnofabric index 5. Depth of bioturbation ranges from centimeters to tens of centimeters, with Thalassinoides dominating trace fossil assemblages. This nearly order-of-magnitude increase in the occurrence of completely bioturbated strata through the Ordovician is consistent with the hypotheses of others who have suggested that an increase in diversity can be accompanied by an increase in utilization of ecospace.

  10. Topsoil Depth Effects on Crop Yields as Affected by Weather

    NASA Astrophysics Data System (ADS)

    Lee, Scott; Cruse, Richard

    2015-04-01

    Topsoil (A-horizon) depth is positively correlated with crop productivity; crop roots and available nutrients are concentrated in this layer; topsoil is critical for nutrient retention and water holding capacity. Its loss or reduction can be considered an irreversible impact of soil erosion. Climatic factors such as precipitation and temperature extremes that impose production stress further complicate the relationship between soil erosion and crop productivity. The primary research objective was to determine the effects of soil erosion on corn and soybean yields of loess and till-derived soils in the rain-fed farming region of Iowa. Data collection took place from 2007 to 2012 at seven farm sites located in different major soil regions. Collection consisted of 40 to 50 randomly selected georeferenced soil probe locations across varying erosion classes in well drained landscape positions. Soil probes were done to a minimum depth of 100 cm and soil organic carbon samples were obtained in the top 10 cm. Crop yields were determined utilizing georeferenced harvest maps from yield monitoring devices and cross referenced with georeferenced field data points. Data analysis targeted relationships between crop yields versus soil organic carbon contents (SOC) and crop yields versus topsoil depths (TSD). The variation of yield and growing season rainfall across multiple years were also evaluated to provide an indication of soil resiliency associated with topsoil depth and soil organic carbon levels across varying climatic conditions. Results varied between sites but generally indicated a greater yield potential at thicker TSD's and higher SOC concentrations; an annual variation in yield response as a function of precipitation amount during the growing season; largest yield responses to both TSD and SOC occurred in the driest study year (2012); and little to no significant yield responses to TSD occurred during the wettest study year (2010). These results were not

  11. Handheld White Light Interferometer for Measuring Defect Depth in Windows

    NASA Technical Reports Server (NTRS)

    Youngquist, Robert; Simmons, Stephen; Cox, Robert

    2010-01-01

    Accurate quantification of defects (scratches and impacts) is vital to the certification of flight hardware and other critical components. The amount of damage to a particular component contributes to the performance, reliability, and safety of a system, which ultimately affects the success or failure of a mission or test. The launch-commit criteria on a Space Shuttle Orbiter window are governed by the depth of the defects that are identified by a visual inspection. This measurement of a defect is not easy to obtain given the environment, size of the defect, and location of the window(s). The determination of depth has typically been performed by taking a mold impression and measuring the impression with an optical profiling instrument. Another method of obtaining an estimate of the depth is by using a refocus microscope. To use a refocus microscope, the surface of the glass and bottom of the defect are, in turn, brought into focus by the operator. The amount of movement between the two points corresponds to the depth of the defect. The refocus microscope requires a skilled operator and has been proven to be unreliable when used on Orbiter windows. White light interferometry was chosen as a candidate to replace the refocus microscope. The White Light Interferometer (WLI) was developed to replace the refocus microscope as the instrument used for measuring the depth of defects in Orbiter windows. The WLI consists of a broadband illumination source, interferometer, detector, motion control, displacement sensor, mechanical housing, and support electronics. The illumination source for the WLI is typically a visible light emitting diode (LED) or a near-infrared superluminescent diode (SLD) with power levels of less than a milliwatt. The interferometer is a Michelson configuration consisting of a 1-in. (2.5-cm) cube beam splitter, a 0.5-in. (1.3-cm) optical window as a movable leg (used to closely match the return intensity of the fixed leg from the window), and a

  12. Formation of asteroids from mm-cm sized grains

    NASA Astrophysics Data System (ADS)

    Carrera, D.; Johansen, A.; Davies, M. B.

    2014-03-01

    Context. Asteroids and comets are intricately connected to life in the universe. Asteroids are the building blocks of terrestrial planets; water-rich asteroids and comets are likely to be the primary source of water for Earth's oceans and other volatiles (Morbidelli et al. 2000; Hartogh et al. 2011); and they may play role in mass extinctions. Yet, the formation of these objects is poorly understood. There is mounting evidence that the traditional picture of the formation of asteroids must be revised. The size distribution of asteroids is hard to reconcile with a traditional bottomup formation scenario. Instead, asteroids may form top-down, with large 100 - 1000 km sized objects forming first by the gravitational collapse of dense clumps of small particles. Experiments and simulations suggest that dust grains cannot grow to sizes larger than mm-cm in protoplanetary disks (Zsom et al. 2010). Also, primitive meteorites from the asteroid belt contain a large mass fraction in chondrules of sizes from 0.1 mm to a few mm. Hence, it is desirable to find a model for asteroid formation from mm-sized particles. Aims. In this work, we model the dynamics of mm-cm sized grains in dust-enriched inner regions of protoplanetary disks. We model the dust-gas interaction to determine whether dust grains of this size can form dense, self-gravitating clouds that can collapse to form asteroids. Methods. We perform shearing box simulations of the inner disk using the Pencil Code (Brandenburg & Dobler 2002). The simulations start with a Solar-type solids-to-gas ratio of 0.01 and we gradually increase the particle concentration. In a real protoplanetary disk, solid particles are expected to migrate from the outer regions and concentrate in the inner disk. Results. Our simulations show that mm-sized particles can form very dense clumps, driven by a run-away convergence in the radial-drift flow of these particles - this dynamic is known as the streaming instability (Youdin & Goodman 2005

  13. A 1.3 cm line survey toward Orion KL

    NASA Astrophysics Data System (ADS)

    Gong, Y.; Henkel, C.; Thorwirth, S.; Spezzano, S.; Menten, K. M.; Walmsley, C. M.; Wyrowski, F.; Mao, R. Q.; Klein, B.

    2015-09-01

    Context. The nearby Orion Kleinmann-Low nebula is one of the most prolific sources of molecular line emission. It has served as a benchmark for spectral line searches throughout the (sub)millimeter regime. Aims: The main goal is to systematically study the spectral characteristics of Orion KL in the λ ~ 1.3 cm band. Methods: We carried out a spectral line survey with the Effelsberg-100 m telescope toward Orion KL. It covers the frequency range between 17.9 GHz and 26.2 GHz, i.e., the radio "K band". We also examined ALMA maps to address the spatial origin of molecules detected by our 1.3 cm line survey. Results: In Orion KL, we find 261 spectral lines, yielding an average line density of about 32 spectral features per GHz above 3σ (a typical value of 3σ is 15 mJy). The identified lines include 164 radio recombination lines (RRLs) and 97 molecular lines. The RRLs, from hydrogen, helium, and carbon, stem from the ionized material of the Orion Nebula, part of which is covered by our beam. The molecular lines are assigned to 13 different molecular species including rare isotopologues. A total of 23 molecular transitions from species known to exist in Orion KL are detected for the first time in the interstellar medium. Non-metastable (J>K) 15NH3 transitions are detected in Orion KL for the first time. Based on the velocity information of detected lines and the ALMA images, the spatial origins of molecular emission are constrained and discussed. A narrow feature is found in SO2 (81,7 - 72,6), but not in other SO2 transitions, possibly suggesting the presence of a maser line. Column densities and fractional abundances relative to H2 are estimated for 12 molecules with local thermodynamic equilibrium (LTE) methods. Rotational diagrams of non-metastable 14NH3 transitions with J = K + 1 to J = K + 4 yield different results; metastable (J = K) 15NH3 is found to have a higher excitation temperature than non-metastable 15NH3, also indicating that they may trace different

  14. Effects of soil depths on nymphal eclosion of Melanoplus sanguinipes (Fabricius)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This work reports on the use of cultural practices to influence grasshoppers nymphal emergence. Grasshopper eggs were buried at depths of 2, 14, 18, 22, and 26 cm in laboratory arenas. Nymph eclosion ranges from 77 to 87%. However, nymph emergence, measured as the number of nymphs that reached the s...

  15. 152Eu depth profiles in granite and concrete cores exposed to the Hiroshima atomic bomb.

    PubMed

    Shizuma, K; Iwatani, K; Hasai, H; Hoshi, M; Oka, T

    1997-06-01

    Two granite and two concrete core samples were obtained within 500 m from the hypocenter of the Hiroshima atomic bomb, and the depth profile of 152Eu was measured to evaluate the incident neutron spectrum. The granite cores were obtained from a pillar of the Motoyasu Bridge located 101 m from the hypocenter and from a granite rock in the Shirakami Shrine (379 m); the concrete cores were obtained from a gate in the Gokoku Shrine (398 m) and from a pillar top of the Hiroshima bank (250 m). The profiles of the specific activities of the cores were measured to a depth of 40 cm from the surface using low background germanium (Ge) spectrometers. According to the measured depth profiles, relaxation lengths of incident neutrons were derived as 13.6 cm for Motoyasu Bridge pillar (granite), 12.2 cm for Shirakami Shrine core (granite), and 9.6 cm for concrete cores of Gokoku Shrine and Hiroshima Bank. In addition, a comparison of the granite cores in Hiroshima showed good agreement with Nagasaki data. Present results indicates that the depth profile of 152Eu reflects incident neutrons not so high but in the epithermal region.

  16. Seasonal Evolution of Titan's South Pole 220 cm-1 Cloud

    NASA Astrophysics Data System (ADS)

    Jennings, Donald

    2016-06-01

    A cloud of ices that had been seen only in Titan's north during winter began to emerge at the south pole in 2012. Discovered by Voyager IRIS as an emission feature at 220 cm-1, the cloud has been studied extensively in both the north and south by Cassini CIRS. The spectral feature acts as a tracer of the seasonal changes at Titan's poles, relating to evolving composition, temperature structure and dynamics. Although candidates have been proposed, the chemical makeup of the cloud has never been identified. The cloud is composed of condensates derived from gases created at high altitude and transported to the cold, shadowed pole. In the north the cloud has diminished gradually over the Cassini mission as Titan has transitioned from winter to spring. The southern cloud, on the other hand, grew rapidly after 2012. By late 2014 it had developed a complex ring structure that was confined to latitudes poleward of 70°S within the deep temperature well that had formed at the south pole [1]. The location of the cloud coincides in latitude with the HCN cloud reported by ISS and VIMS [2,3]. CIRS also saw enhanced gas emissions at those latitudes [4]. When it first formed, the cloud was abundant at altitudes as high as 250 km, while later it was found mostly at 100-150 km, suggesting that the material that had been deposited from above had gathered at the lower altitudes. Radiance from the southern cloud increased until mid-2015 and since then has decreased. The cloud may be transitioning to the more uniform hood morphology familiar in the north. Taking the north and south together, by the end of the Cassini mission in 2017 we will have observed almost an entire seasonal cycle of the ice cloud.

  17. Molecular depth profiling in ice matrices using C 60 projectiles

    NASA Astrophysics Data System (ADS)

    Wucher, A.; Sun, S.; Szakal, C.; Winograd, N.

    2004-06-01

    The prospects of molecular sputter depth profiling using C 60+ projectiles were investigated on thick ice layers prepared by freezing aqueous solutions of histamine onto a metal substrate. The samples were analyzed in a ToF-SIMS spectrometer equipped with a liquid metal Ga + ion source and a newly developed fullerene ion source. The C 60+ beam was used to erode the surface, while static ToF-SIMS spectra were taken with both ion beams alternatively between sputtering cycles. We find that the signals both related to the ice matrix and to the histamine are about two orders of magnitude higher under 20-keV C 60 than under 15-keV Ga bombardment. Histamine related molecular signals are found to increase drastically if the freshly introduced surface is pre-sputtered with C 60 ions, until at a total ion fluence of about 10 13 cm -2 the spectra are completely dominated by the molecular ion and characteristic fragments of histamine. At larger fluence, the signal is found to decrease with a disappearance cross section of approximately 10 -14 cm 2, until at total fluences of about 10 14 cm -2 a steady state with stable molecular signals is reached. In contrast, no appreciable molecular signal could be observed if Ga + ions were used to erode the surface.

  18. Effect of acupuncture depth on muscle pain

    PubMed Central

    2011-01-01

    Background While evidence supports efficacy of acupuncture and/or dry needling in treating musculoskeletal pain, it is unclear which needling method is most effective. This study aims to determine the effects of depth of needle penetration on muscle pain. Methods A total of 22 healthy volunteers performed repeated eccentric contractions to induce muscle soreness in their extensor digital muscle. Subjects were assigned randomly to four groups, namely control group, skin group (depth of 3 mm: the extensor digital muscle), muscle group (depth of 10 mm: the extensor digital muscle) and non-segmental group (depth of 10 mm: the anterior tibial muscle). Pressure pain threshold and electrical pain threshold of the skin, fascia and muscle were measured at a point 20 mm distal to the maximum tender point on the second day after the exercise. Results Pressure pain thresholds of skin group (depth of 3 mm: the extensor digital muscle) and muscle group (depth of 10 mm: the extensor digital muscle) were significantly higher than the control group, whereas the electrical pain threshold at fascia of muscle group (depth of 10 mm: the extensor digital muscle) was a significantly higher than control group; however, there was no significant difference between the control and other groups. Conclusion The present study shows that acupuncture stimulation of muscle increases the PPT and EPT of fascia. The depth of needle penetration is important for the relief of muscle pain. PMID:21696603

  19. "Depth" Matters in High School Science Studies

    ERIC Educational Resources Information Center

    Cavanagh, Sean

    2009-01-01

    This article reports on the findings of a recent study that examines one of the most enduring debates in science instruction--whether "depth" or "breadth" of knowledge is most important. Its authors come down on the side of depth. The study found that high school students who focus more intensely on core topics within their biology, chemistry, and…

  20. Improved Boundary Layer Depth Retrievals from MPLNET

    NASA Technical Reports Server (NTRS)

    Lewis, Jasper R.; Welton, Ellsworth J.; Molod, Andrea M.; Joseph, Everette

    2013-01-01

    Continuous lidar observations of the planetary boundary layer (PBL) depth have been made at the Micropulse Lidar Network (MPLNET) site in Greenbelt, MD since April 2001. However, because of issues with the operational PBL depth algorithm, the data is not reliable for determining seasonal and diurnal trends. Therefore, an improved PBL depth algorithm has been developed which uses a combination of the wavelet technique and image processing. The new algorithm is less susceptible to contamination by clouds and residual layers, and in general, produces lower PBL depths. A 2010 comparison shows the operational algorithm overestimates the daily mean PBL depth when compared to the improved algorithm (1.85 and 1.07 km, respectively). The improved MPLNET PBL depths are validated using radiosonde comparisons which suggests the algorithm performs well to determine the depth of a fully developed PBL. A comparison with the Goddard Earth Observing System-version 5 (GEOS-5) model suggests that the model may underestimate the maximum daytime PBL depth by 410 m during the spring and summer. The best agreement between MPLNET and GEOS-5 occurred during the fall and they diered the most in the winter.

  1. Contextualizing Range and Depth in Indian English.

    ERIC Educational Resources Information Center

    D'Souza, Jean

    2001-01-01

    Examines the range and depth of English in India and argues that these Kachruvian notions go a long way towards explaining how the language is used, exploited, extended, and recreated in the sub-continent. Data, both written and spoken, are presented, and it is suggested that in-depth analyses of such data are a prerequisite to any real…

  2. Differential Cognitive Cues in Pictorial Depth Perception.

    ERIC Educational Resources Information Center

    Omari, Issa M.; Cook, Harold

    The experiment described in this report investigates the effects of various cognitive cues in questions asked regarding the relationship of elements in pictorial depth perception. The subjects of this study are 40 third grade Black and Puerto Rican children. They are confronted with four pictures from the Hudson Depth Perception Tests and asked to…

  3. [Effects of sensor's laying depth for precision irrigation on growth characteristics of maturate grapes].

    PubMed

    Wang, Yu-Ning; Fan, Jun; Li, Shi-Qing; Zheng, Chen; Wang, Quan-Jiu

    2012-08-01

    In order to approach the appropriate laying depth of soil moisture sensor to control irrigation amount, the sensors were laid at different soil depth to measure the soil moisture content, with the effects of definite irrigation amount on the growth characteristics of maturate grapes studied. The results showed that using the sensor laying at the soil depth 40 cm (SF40) to control irrigation amount, the biological characteristics of the grapes, including photosynthesis, grape yield, and water use efficiency were superior than those when the sensor was laid at the depth 20 cm (SF20) and under conventional furrow irrigation (CK). The grape brix degree in treatment SF40 was slightly lower than that in treatments SF20 and CK, but was still near 20%. In treatment SF40, the irrigated water could infiltrate or redistribute in the soil layers where the main roots of the grapes existed. It was suggested that laying soil moisture sensor at the depth 40 cm could better control the irrigation amount for the maturate grapes in the study area.

  4. On the ability of RegCM4 regional climate model to simulate surface solar radiation patterns over Europe: an assessment using satellite-based observations

    NASA Astrophysics Data System (ADS)

    Alexandri, G.; Georgoulias, A. K.; Zanis, P.; Katragkou, E.; Tsikerdekis, A.; Kourtidis, K.; Meleti, C.

    2015-07-01

    In this work, we assess the ability of RegCM4 regional climate model to simulate surface solar radiation (SSR) patterns over Europe. A decadal RegCM4 run (2000-2009) was implemented and evaluated against satellite-based observations from the Satellite Application Facility on Climate Monitoring (CM SAF) showing that the model simulates adequately the SSR patterns over the region. The bias between RegCM4 and CM SAF is +1.54 % for MFG (Meteosat First Generation) and +3.34 % for MSG (Meteosat Second Generation) observations. The relative contribution of parameters that determine the transmission of solar radiation within the atmosphere to the deviation appearing between RegCM4 and CM SAF SSR is also examined. Cloud macrophysical and microphysical properties such as cloud fractional cover (CFC), cloud optical thickness (COT) and cloud effective radius (Re) from RegCM4 are evaluated against data from CM SAF. The same procedure is repeated for aerosol optical properties such as aerosol optical depth (AOD), asymmetry factor (ASY) and single scattering albedo (SSA), as well as other parameters including surface broadband albedo (ALB) and water vapor amount (WV) using data from MACv1 aerosol climatology, from CERES satellite sensors and from ERA-Interim reanalysis. It is shown here that the good agreement between RegCM4 and satellite-based SSR observations can be partially attributed to counteracting effects among the above mentioned parameters. The contribution of each parameter to the RegCM4-CM SAF SSR deviations is estimated with the combined use of the aforementioned data and a radiative transfer model (SBDART). CFC, COT and AOD are the major determinants of these deviations; however, the other parameters also play an important role for specific regions and seasons.

  5. Depth of origin of magma in eruptions

    PubMed Central

    Becerril, Laura; Galindo, Ines; Gudmundsson, Agust; Morales, Jose Maria

    2013-01-01

    Many volcanic hazard factors - such as the likelihood and duration of an eruption, the eruption style, and the probability of its triggering large landslides or caldera collapses - relate to the depth of the magma source. Yet, the magma source depths are commonly poorly known, even in frequently erupting volcanoes such as Hekla in Iceland and Etna in Italy. Here we show how the length-thickness ratios of feeder dykes can be used to estimate the depth to the source magma chamber. Using this method, accurately measured volcanic fissures/feeder-dykes in El Hierro (Canary Islands) indicate a source depth of 11–15 km, which coincides with the main cloud of earthquake foci surrounding the magma chamber associated with the 2011–2012 eruption of El Hierro. The method can be used on widely available GPS and InSAR data to calculate the depths to the source magma chambers of active volcanoes worldwide. PMID:24067336

  6. Contour detection combined with depth information

    NASA Astrophysics Data System (ADS)

    Xiao, Jie; Cai, Chao

    2015-12-01

    Many challenging computer vision problems have been proven to benefit from the incorporation of depth information, to name a few, semantic labellings, pose estimations and even contour detection. Different objects have different depths from a single monocular image. The depth information of one object is coherent and the depth information of different objects may vary discontinuously. Meanwhile, there exists a broad non-classical receptive field (NCRF) outside the classical receptive field (CRF). The response of the central neuron is affected not only by the stimulus inside the CRF, but also modulated by the stimulus surrounding it. The contextual modulation is mediated by horizontal connections across the visual cortex. Based on the findings and researches, a biological-inspired contour detection model which combined with depth information is proposed in this paper.

  7. Depth of origin of magma in eruptions.

    PubMed

    Becerril, Laura; Galindo, Ines; Gudmundsson, Agust; Morales, Jose Maria

    2013-01-01

    Many volcanic hazard factors--such as the likelihood and duration of an eruption, the eruption style, and the probability of its triggering large landslides or caldera collapses--relate to the depth of the magma source. Yet, the magma source depths are commonly poorly known, even in frequently erupting volcanoes such as Hekla in Iceland and Etna in Italy. Here we show how the length-thickness ratios of feeder dykes can be used to estimate the depth to the source magma chamber. Using this method, accurately measured volcanic fissures/feeder-dykes in El Hierro (Canary Islands) indicate a source depth of 11-15 km, which coincides with the main cloud of earthquake foci surrounding the magma chamber associated with the 2011-2012 eruption of El Hierro. The method can be used on widely available GPS and InSAR data to calculate the depths to the source magma chambers of active volcanoes worldwide. PMID:24067336

  8. Depth perception through circular movements of dots.

    PubMed

    Ito, Hiroyuki

    2010-01-01

    Elements that move with velocity gradients have been shown to give the impression of depth. In this study, it was found that dots in circular motion around a line of sight give a depth impression corresponding to the gradients of the angular velocities of circular motion on a screen. The results of two experiments show that depth perception through circular motion is as effective as that through expansion or spiral motion, but less effective than that through lateral motion parallax when the local speed distributions on the screen are matched. The present depth effect shows that expansion-contraction, spiral, and circular motions are a continuum in terms of producing depth effects; they differ from lateral motion parallax.

  9. Depth of origin of magma in eruptions.

    PubMed

    Becerril, Laura; Galindo, Ines; Gudmundsson, Agust; Morales, Jose Maria

    2013-09-26

    Many volcanic hazard factors--such as the likelihood and duration of an eruption, the eruption style, and the probability of its triggering large landslides or caldera collapses--relate to the depth of the magma source. Yet, the magma source depths are commonly poorly known, even in frequently erupting volcanoes such as Hekla in Iceland and Etna in Italy. Here we show how the length-thickness ratios of feeder dykes can be used to estimate the depth to the source magma chamber. Using this method, accurately measured volcanic fissures/feeder-dykes in El Hierro (Canary Islands) indicate a source depth of 11-15 km, which coincides with the main cloud of earthquake foci surrounding the magma chamber associated with the 2011-2012 eruption of El Hierro. The method can be used on widely available GPS and InSAR data to calculate the depths to the source magma chambers of active volcanoes worldwide.

  10. Models of the Cosmological 21 cm Signal from the Epoch of Reionization Calibrated with Lyα and CMB Data

    NASA Astrophysics Data System (ADS)

    Kulkarni, Girish; Choudhury, Tirthankar Roy; Puchwein, Ewald; Haehnelt, Martin G.

    2016-08-01

    We present here 21 cm predictions from high dynamic range simulations for a range of reionization histories that have been tested against available Lyα and CMB data. We assess the observability of the predicted spatial 21 cm fluctuations by ongoing and upcoming experiments in the late stages of reionization in the limit in which the hydrogen spin temperature is significantly larger than the CMB temperature. Models consistent with the available Lyα data and CMB measurement of the Thomson optical depth predict typical values of 10-20 mK2 for the variance of the 21 cm brightness temperature at redshifts z = 7-10 at scales accessible to ongoing and upcoming experiments (k ≲ 1 cMpc-1h). This is within a factor of a few magnitude of the sensitivity claimed to have been already reached by ongoing experiments in the signal rms value. Our different models for the reionization history make markedly different predictions for the redshift evolution and thus frequency dependence of the 21 cm power spectrum and should be easily discernible by LOFAR (and later HERA and SKA1) at their design sensitivity. Our simulations have sufficient resolution to assess the effect of high-density Lyman limit systems that can self-shield against ionizing radiation and stay 21 cm bright even if the hydrogen in their surroundings is highly ionized. Our simulations predict that including the effect of the self-shielded gas in highly ionized regions reduces the large scale 21 cm power by about 30%.

  11. ROV seafloor surveys combining 5-cm lateral resolution multibeam bathymetry with color stereo photographic imagery

    NASA Astrophysics Data System (ADS)

    Caress, D. W.; Hobson, B.; Thomas, H. J.; Henthorn, R.; Martin, E. J.; Bird, L.; Rock, S. M.; Risi, M.; Padial, J. A.

    2013-12-01

    The Monterey Bay Aquarium Research Institute is developing a low altitude, high-resolution seafloor mapping capability that combines multibeam sonar with stereo photographic imagery. The goal is to obtain spatially quantitative, repeatable renderings of the seafloor with fidelity at scales of 5 cm or better from altitudes of 2-3 m. The initial test surveys using this sensor system are being conducted from a remotely operated vehicle (ROV). Ultimately we intend to field this survey system from an autonomous underwater vehicle (AUV). This presentation focuses on the current sensor configuration, methods for data processing, and results from recent test surveys. Bathymetry data are collected using a 400-kHz Reson 7125 multibeam sonar. This configuration produces 512 beams across a 135° wide swath; each beam has a 0.5° acrosstrack by 1.0° alongtrack angular width. At a 2-m altitude, the nadir beams have a 1.7-cm acrosstrack and 3.5 cm alongtrack footprint. Dual Allied Vision Technology GX1920 2.8 Mpixel color cameras provide color stereo photography of the seafloor. The camera housings have been fitted with corrective optics achieving a 90° field of view through a dome port. Illumination is provided by dual 100J xenon strobes. Position, depth, and attitude data are provided by a Kearfott SeaDevil Inertial Navigation System (INS) integrated with a 300 kHz RDI Doppler velocity log (DVL). A separate Paroscientific pressure sensor is mounted adjacent to the INS. The INS Kalman filter is aided by the DVL velocity and pressure data, achieving navigational drift rates less than 0.05% of the distance traveled during surveys. The sensors are mounted onto a toolsled fitted below MBARI's ROV Doc Ricketts with the sonars, cameras and strobes all pointed vertically down. During surveys the ROV flies at a 2-m altitude at speeds of 0.1-0.2 m/s. During a four-day R/V Western Flyer cruise in June 2013, we successfully collected multibeam and camera survey data from a 2-m altitude

  12. Accurate measurement of the H I column density from H I 21 cm absorption-emission spectroscopy

    NASA Astrophysics Data System (ADS)

    Chengalur, Jayaram N.; Kanekar, Nissim; Roy, Nirupam

    2013-07-01

    We present a detailed study of an estimator of the H I column density, based on a combination of H I 21 cm absorption and H I 21cm emission spectroscopy. This `isothermal' estimate is given by NHI, ISO = 1.823 × 1018 ∫ [τtot × TB / [ 1 - e-τtot]dV, where τtot is the total H I 21cm optical depth along the sightline and TB is the measured brightness temperature. We have used a Monte Carlo simulation to quantify the accuracy of the isothermal estimate by comparing the derived NHI, ISO with the true H I column density NHI. The simulation was carried out for a wide range of sightlines, including gas in different temperature phases and random locations along the path. We find that the results are statistically insensitive to the assumed gas temperature distribution and the positions of different phases along the line of sight. The median value of the ratio of the true H I column density to the isothermal estimate, NHI/NHI, ISO, is within a factor of 2 of unity while the 68.2 per cent confidence intervals are within a factor of ≈3 of unity, out to high H I column densities, ≤5 × 1023 cm-2 per 1 km s-1 channel, and high total optical depths, ≤1000. The isothermal estimator thus provides a significantly better measure of the H I column density than other methods, within a factor of a few of the true value even at the highest columns, and should allow us to directly probe the existence of high H I column density gas in the Milky Way.

  13. A depth camera for natural human-computer interaction based on near-infrared imaging and structured light

    NASA Astrophysics Data System (ADS)

    Liu, Yue; Wang, Liqiang; Yuan, Bo; Liu, Hao

    2015-08-01

    Designing of a novel depth camera is presented, which targets close-range (20-60cm) natural human-computer interaction especially for mobile terminals. In order to achieve high precision through the working range, a two-stepping method is employed to match the near infrared intensity image to absolute depth in real-time. First, we use structured light achieved by an 808nm laser diode and a Dammann grating to coarsely quantize the output space of depth values into discrete bins. Then use a learning-based classification forest algorithm to predict the depth distribution over these bins for each pixel in the image. The quantitative experimental results show that this depth camera has 1% precision over range of 20-60cm, which show that the camera suit resource-limited and low-cost application.

  14. Depth Analogy: Data-Driven Approach for Single Image Depth Estimation Using Gradient Samples.

    PubMed

    Choi, Sunghwan; Min, Dongbo; Ham, Bumsub; Kim, Youngjung; Oh, Changjae; Sohn, Kwanghoon

    2015-12-01

    Inferring scene depth from a single monocular image is a highly ill-posed problem in computer vision. This paper presents a new gradient-domain approach, called depth analogy, that makes use of analogy as a means for synthesizing a target depth field, when a collection of RGB-D image pairs is given as training data. Specifically, the proposed method employs a non-parametric learning process that creates an analogous depth field by sampling reliable depth gradients using visual correspondence established on training image pairs. Unlike existing data-driven approaches that directly select depth values from training data, our framework transfers depth gradients as reconstruction cues, which are then integrated by the Poisson reconstruction. The performance of most conventional approaches relies heavily on the training RGB-D data used in the process, and such a dependency severely degenerates the quality of reconstructed depth maps when the desired depth distribution of an input image is quite different from that of the training data, e.g., outdoor versus indoor scenes. Our key observation is that using depth gradients in the reconstruction is less sensitive to scene characteristics, providing better cues for depth recovery. Thus, our gradient-domain approach can support a great variety of training range datasets that involve substantial appearance and geometric variations. The experimental results demonstrate that our (depth) gradient-domain approach outperforms existing data-driven approaches directly working on depth domain, even when only uncorrelated training datasets are available. PMID:26529766

  15. Physical Simulation of Maximum Seasonal Soil Freezing Depth in the United States Using Routine Weather Observations.

    NASA Astrophysics Data System (ADS)

    Degaetano, Arthur T.; Cameron, Michael D.; Wilks, Daniel S.

    2001-03-01

    An existing, physically based soil freezing model applicable to humid climates is modified for use in the central and western United States. Simulations using the state-of-the-art Simultaneous Heat and Water (SHAW) model indicated that the original model required the addition of a water budgeting scheme and alteration of the equation for soil thermal conductivity. Using only daily temperature, liquid precipitation, snowfall, and snow cover, this new model allows the simulation of maximum seasonal frost depths at several thousand U.S. stations.Comparison of the model-derived maximum frost depths with observed and soil temperature-inferred soil freezing maxima at 32 arid and semiarid locations indicates excellent agreement. Observed maximum soil freezing depths, ranging from 0 to over 100 cm, are simulated, with an average absolute error of 5.4 cm. At individual stations, the seasonal penetration and thawing of soil freezing tracks that of the observations very closely, regardless of ambient soil moisture conditions.

  16. MEMS scanner enabled real-time depth sensitive hyperspectral imaging of biological tissue

    PubMed Central

    Wang, Youmin; Bish, Sheldon; Tunnell, James W; Zhang, Xiaojing

    2010-01-01

    We demonstrate a hyperspectral and depth sensitive diffuse optical imaging microsystem, where fast scanning is provided by a CMOS compatible 2-axis MEMS mirror. By using lissajous scanning patterns, large field-of-view (FOV) of 1.2cm x 1.2cm images with lateral resolution of 100µm can be taken at 1.3 frames-per-second (fps). Hyperspectral and depth-sensitive images were acquired on tissue simulating phantom samples containing quantum dots (QDs) patterned at various depths in Polydimethylsiloxane (PDMS). Device performance delivers 6 nm spectral resolution and 0.43 wavelengths per second acquisition speed. A sample of porcine epithelium with subcutaneously placed QDs was also imaged. Images of the biological sample were processed by spectral unmixing in order to qualitatively separate chromophores in the final images and demonstrate spectral performance of the imaging system. PMID:21164757

  17. Results of an air data probe investigation utilizing a 0.10 scale orbiter forebody (model 57-0) in the Ames Research Center 14-foot wind tunnel (OA220)

    NASA Technical Reports Server (NTRS)

    Esparza, V.; Thornton, D. E.

    1976-01-01

    Results are presented of a 0.10 scale orbiter forebody test with left and right mounted air data probes (ADP) as well as a flight test probe (nose boom). Left and right ADP data were obtained at Mach numbers of .3, .4, .5, .6, .7, .8, .85, .9, .95, .98, 1.05 and 1.1 through a Reynolds number range of 1.3 to 4.4 million. Nose boom data were obtained at Mach numbers of .3, .4, .5, .6, .7, .9 and .98.

  18. Luminescence and dielectric properties of c-axis oriented (Bi1.90Eu0.10)(V1-zMoz)O5.5 ferroelectric thin films

    NASA Astrophysics Data System (ADS)

    Xie, Wei; Zou, Changwei; Xie, Mubiao; Bao, Dinghua

    2016-05-01

    (Bi1.90Eu0.10)(V1-zMoz)O5.5 (z = 0, 0.05, 0.10, 0.15 and 0.20) thin films with c-axis oriented were prepared on Pt(111)/Ti/SiO2/Si substrates by using chemical solution deposition method. The effect of Mo6+ concentration on the structure, luminescence properties and dielectric properties of the thin films were characterized systematically. X-ray diffraction data indicates that the thin films with low Mo6+-doping content can remain Bi2VO5.5 structure. When the Mo6+-doping content z reaches to 0.15, the thin films are a mixture of diphase with the main phase Bi2VO5.5 and secondary phase Bi2MoO6. Under UV irradiation, all the thin films emit a bright red or orange emission which origin from Eu3+. With increasing Mo6+-doping content z, the relative intensity of the Red and Orange emissions show obviously change. The value of Red/Orange ratio first decrease, and it reached minimum when z is 0.15, then it recover to the initial value. The variation trend of the Red/Orange ratio reflects the change of the lattice symmetry. Dielectric constant of the thin films increased with the increasing of the Mo6+ concentration while dielectric loss decreased. The decrease of the quantities of oxygen vacancies and the generation of Bi2MoO6 phase are responsible for the improvement of electric properties. These results explain that Eu3+ion can be used as an effective luminescent probe in (Bi1.90Eu0.10)(V1-zMoz)O5.5 (z = 0, 0.05, 0.10, 0.15 and 0.20) thin films, and the electric properties of the thin films can be improved by Mo6+ doping.

  19. Seismic depth conversion vs. structural validation

    NASA Astrophysics Data System (ADS)

    Totake, Yukitsugu; Butler, Rob; Bond, Clare

    2016-04-01

    Interpretation based on seismic reflection data is inherently an uncertain product based on imperfect datasets, with limits in data resolution and spatial extent. This has boosted geologists to use structural validation techniques to verify their seismic interpretations for many years. Structural validation of seismic interpretations should be ideally completed on depth sections, which are converted from time domain using velocities derived from well checkshot survey, seismic velocity analysis, or even estimates. Choices of velocity model critically control the final depth image and hence structural geometry of interpretations that are used as initial datasets for structural validations. However, the depth conversion is never perfectly accurate because of absence of depth constraint. Now, how robust are structural validation techniques to depth conversion uncertainty? Here we explore how structural validation techniques respond to different versions of depth interpretations converted by different velocities. We use a seismic time-based image of a fold-thrust structure in the deepwater Niger Delta to interpret, and convert to depth using three different velocity models: constant velocity (VM1); a single layer having initial velocity v0 at layer top with vertical velocity gradient k (VM2); and three layers having each v0-k set (VM3) below seabed. Forward modelling, automated trishear modelling algorithm called 'inverse trishear modelling' and Groshong's area-depth-strain (ADS) methods are applied to test the structural geometry of the depth-converted interpretations. We find forward modelling and inverse trishear modelling reasonably 'fit' all versions of interpretation, regardless of the velocity model used for depth conversion, with multiple sets of model parameters. On the other hand, only velocity model VM3 'passes' the ADS validation method, with the detachment level interpreted concordant with the depth estimated from excess area analysis, based on interpreted

  20. Absolute intensities for the Q-branch of the 3 nu(sub 2) (-) nu(sub 1) (465.161/cm) band of nitrous oxide

    NASA Technical Reports Server (NTRS)

    Sirota, J. Marcos; Reuter, Dennis C.

    1993-01-01

    The absolute intensities of four lines, Q 15-Q 18 in the 03(sup 1)0-10(sup 0)0 band, of N2O have been measured using a tunable diode laser spectrometer at temperatures between 380 and 420 K and pressures between 4 and 15 torr. Even though these transitions are weak and produced only about 2% of absorption at the line center for a pathlength of 52 m, they were measured with a signal to noise ratio of about 20 due to the high sensitivity of the instrument. The band strength derived is 1.03 x 10(exp -24) cm/molec at 296 K.

  1. Germination and emergence of annual species and burial depth: Implications for restoration ecology

    NASA Astrophysics Data System (ADS)

    Limón, Ángeles; Peco, Begoña

    2016-02-01

    Due to the high content of viable seeds, topsoil is usually spread on ground left bare during railway and motorway construction to facilitate the regeneration of vegetation cover. However, during handling of the topsoil, seeds are often buried deeply and they cannot germinate or the seedlings cannot emerge from depth. This study experimentally explores the predictive value of seed mass for seed germination, mortality and seedling emergence at different burial depths for 13 common annual species in semiarid Mediterranean environments. We separate the effect of burial depth on germination and emergence by means of two experiments. In the germination experiment, five replicates of 20 seeds for each species were buried at depths ranging from 0 to 4 cm under greenhouse conditions. Germinated and empty or rotten seeds were counted after 8 weeks. In the emergence experiment, five replicates of four newly-germinated seeds per species were buried at the same depths under controlled conditions and emergence was recorded after 3 weeks. The effect of burial depth on percentage of germination and seedling emergence was dependent on seed size. Although all species showed a decrease in germination with burial depth, this decrease was greater for small-than large-seeded species. Percentage of emergence was positively related to seed mass but negatively related to burial depth. Seed mortality was higher for small-than large-seeded species, but there was no general effect of burial depth on this variable. Thus, the current practice of spreading 30 cm deep layers of topsoil in post-construction restoration projects is unadvisable. In this restoration scenario, thinner layers of topsoil should be used to achieve the maximum potential of the topsoil for germination and seedling establishment.

  2. Remotely Measuring Snow Depth in Inaccessible Terrain

    NASA Astrophysics Data System (ADS)

    Dixon, D.; Boon, S.

    2010-12-01

    In watershed-scale studies of snow accumulation, high alpine areas are typically important accumulation areas. While snow depth measurements may not be collected in these regions due to avalanche danger, failing to include them in basin-wide estimates of snow accumulation may lead to large underestimates of basin-scale water yield. We present a new method to measure spatially distributed point snow depths remotely. Previously described methods using terrestrial laser scanning (TLS) systems, airborne light detection and ranging (LiDAR) systems, and hand-held laser distance meters have several limitations related to cost, data processing, and accuracy, thus reducing their applicability. The use of a modern robotic total station attempts to resolve these limitations. Total stations have much greater measurement accuracy than laser distance meters, and are significantly less expensive then TLS and LiDAR systems. Data can be output in common data formats, simplifying data processing and management. Measurement points can also be resampled repeatedly throughout the season with high accuracy and precision. Simple trigonometry is used to convert total station measurements into estimates of snow depth perpendicular to the slope. We present results of remote snow depth measurements using a Leica Geosystems TCRP 1201+ robotic total station. Snow depth estimates from the station are validated against measured depths in a field trial. The method is then applied in a basin-scale study to collect and calculate high elevation snow depth, in combination with traditional snow surveys at lower elevations.

  3. Boundary Depth Information Using Hopfield Neural Network

    NASA Astrophysics Data System (ADS)

    Xu, Sheng; Wang, Ruisheng

    2016-06-01

    Depth information is widely used for representation, reconstruction and modeling of 3D scene. Generally two kinds of methods can obtain the depth information. One is to use the distance cues from the depth camera, but the results heavily depend on the device, and the accuracy is degraded greatly when the distance from the object is increased. The other one uses the binocular cues from the matching to obtain the depth information. It is more and more mature and convenient to collect the depth information of different scenes by stereo matching methods. In the objective function, the data term is to ensure that the difference between the matched pixels is small, and the smoothness term is to smooth the neighbors with different disparities. Nonetheless, the smoothness term blurs the boundary depth information of the object which becomes the bottleneck of the stereo matching. This paper proposes a novel energy function for the boundary to keep the discontinuities and uses the Hopfield neural network to solve the optimization. We first extract the region of interest areas which are the boundary pixels in original images. Then, we develop the boundary energy function to calculate the matching cost. At last, we solve the optimization globally by the Hopfield neural network. The Middlebury stereo benchmark is used to test the proposed method, and results show that our boundary depth information is more accurate than other state-of-the-art methods and can be used to optimize the results of other stereo matching methods.

  4. Meiofauna communities along an abyssal depth gradient in the Drake Passage

    NASA Astrophysics Data System (ADS)

    Gutzmann, E.; Martínez Arbizu, P.; Rose, A.; Veit-Köhler, G.

    2004-07-01

    Meiofauna standing stocks and community structure are reported for the first time for abyssal soft-sediment samples in Antarctic waters. At seven stations within a depth range of 2274-5194 m a total of 128 sediment cores were retrieved with a multiple corer (MUC) on board of the R.V. Polarstern during the ANDEEP-1 cruise (ANT XIX/3). The metazoan meiofauna (defined by a lower size limit of 40 μm) was identified and counted, and one core per station was preserved for CPE, C/N, TOM and grain size analyses. Meiofauna densities are in the range of 2731 Ind./10 cm 2 at 2290 m depth and 75 Ind./10 cm 2 at 3597 m depth, with nematodes being the dominant group at all stations. Nematodes account for 84-94% followed by copepods with 2-8% of the total meiofauna. Other frequent taxa found at each station are kinorhynchs, loriciferans, tantulocarids, ostracods and tardigrades. There is a general tendency of decreasing abundances of metazoan meiofauna with increasing depth, but not all higher level taxa displayed this pattern. In addition, a tendency of decreasing higher taxon density with increasing depth was observed. Standing stocks are higher than the average found at similar depths in other oceans.

  5. Experimental shock metamorphism of the Murchison CM carbonaceous chondrite

    NASA Astrophysics Data System (ADS)

    Tomeoka, Kazushige; Yamahana, Yasuhiro; Sekine, Toshimori

    1999-11-01

    A series of shock-recovery experiments were carried out on the Murchison CM carbonaceous chondrite by using a single-stage propellant gun. The Murchison samples were shocked in nine experiments at peak pressures from 4 to 49 GPa. The recovered samples were studied in detail by using an optical microscope, a scanning electron microscope and an electron-probe microanalyzer. Chondrules are flattened in the plane of the shock front at 4 to 30 GPa. The mean aspect ratio of chondrules increases from 1.17 to 1.57 roughly in proportion to the intensity of shock pressure up to ˜25 GPa. At 25 to 30 GPa, the mean aspect ratio does not increase further, and chondrules show increasingly more random orientations and degrade their preferred orientations, and at ˜35 GPa, they are extensively disrupted. Most coarse grains of olivine and pyroxene are irregularly fractured, fracture density increases with increasing shock pressure and at ˜30 GPa almost all are thoroughly fractured with subgrains of <1 to 5 μm in size. At ˜20 GPa, subparallel fractures begin to form in the matrix in directions roughly perpendicular to the compression axis and their densities increase with pressure, especially dramatically at 25 to 30 GPa; thus, the sample is increasingly comminuted and becomes fragile. Local shock melting occurs as melt veins and pockets at 20 to 30 GPa. Fracture-filling veins of fine grains of matrix are also produced at 25 to 30 GPa. The melts and the fine grains seem to result mainly from frictional heating due to displacement along fractures. At ˜35 GPa, melting occurs pervasively throughout the matrix. The melts are mainly produced from the matrix; however, they are consistently more enriched in Fe, S, and Ca, which indicates that these elements are selectively incorporated into the melts. The melts contain tiny spherules of Fe-Ni metal, Fe sulfide, and numerous vesicles. At 49 GPa, the matrix is totally melted and coarse grains of olivine are partially melted. The melts

  6. Improved tilt-depth method for fast estimation of top and bottom depths of magnetic bodies

    NASA Astrophysics Data System (ADS)

    Wang, Yan-Guo; Zhang, Jin; Ge, Kun-Peng; Chen, Xiao; Nie, Feng-Jun

    2016-06-01

    The tilt-depth method can be used to make fast estimation of the top depth of magnetic bodies. However, it is unable to estimate bottom depths and its every inversion point only has a single solution. In order to resolve such weaknesses, this paper presents an improved tilt-depth method based on the magnetic anomaly expression of vertical contact with a finite depth extent, which can simultaneously estimate top and bottom depths of magnetic bodies. In addition, multiple characteristic points are selected on the tilt angle map for joint computation to improve reliability of inversion solutions. Two- and threedimensional model tests show that this improved tilt-depth method is effective in inverting buried depths of top and bottom bodies, and has a higher inversion precision for top depths than the conventional method. The improved method is then used to process aeromagnetic data over the Changling Fault Depression in the Songliao Basin, and inversion results of top depths are found to be more accurate for actual top depths of volcanic rocks in two nearby drilled wells than those using the conventional tilt-depth method.

  7. Exploratory depth-of-burst experiments

    SciTech Connect

    Reichenbach, H.; Behrens, K.; Kuhl, A.

    1991-12-12

    This report describes the first small-scale explosion experiments with aerated grout (i.e., YTONG). Apart from data referring to crater depth and volume versus depth of burst (DOB), isobaric DOB curves in the range of 1.5 psi {le} p {le} 15 psi were established. The comparison with previous HOB values shows that the ground range to a given overpressure is considerably reduced with increasing depth of burst. The authors plan to continue the airblast investigations with different types of soil materials.

  8. Control of electrode depth in electroslag remelting

    DOEpatents

    Melgaard, David K.; Shelmidine, Gregory J.; Damkroger, Brian K.

    2002-01-01

    A method of and apparatus for controlling an electroslag remelting furnace by driving the electrode at a nominal speed based upon melting rate and geometry while making minor proportional adjustments based on a measured metric of the electrode immersion depth. Electrode drive speed is increased if a measured metric of electrode immersion depth differs from a set point by a predetermined amount, indicating that the tip is too close to the surface of a slag pool. Impedance spikes are monitored to adjust the set point for the metric of electrode immersion depth based upon one or more properties of the impedance spikes.

  9. Composition and temperature dependence of ferroelectric and pyroelectric properties of (1 − x)[PMN–PT(65/35)]–xPZ (0 ≤ x ≤ 0.10) ceramics

    SciTech Connect

    Jiang, Tong; Li, Qiang; Yan, Qingfeng; Luo, Nengneng; Zhang, Yiling; Chu, Xiangcheng

    2014-11-15

    Highlights: • PMN–PT–PZ ceramics with PZ content smaller than 0.10 mol% were synthesized. • T{sub rt} of the PMN–PT–PZ ceramics increased linearly with the increase of PZ constant. • A mutation of the ferroelectric and pyroelectric properties was observed near T{sub rt}. - Abstract: (1 − x)[Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}–PbTiO{sub 3} (65/35)]–xPbZrO{sub 3} (PMN–PT–PZ) ceramics near morphotropic phase boundary with 0 ≤ x ≤ 0.10 were synthesized via the conventional solid-state reaction method. X-ray diffraction and variable temperature dielectric property characterization indicated that the rhombohedral to tetragonal phase transition temperature (T{sub rt}) increased linearly with the increase of PZ constant. The composition and temperature dependence of their ferroelectric and pyroelectric properties were also investigated. The results showed that there appeared mutation for remnant polarization, coercive field, as well as pyroelectric coefficient at the temperate range near T{sub rt}, which was ascribed to the reorientation of dipoles caused by the rhombohedral–tetragonal phase transition.

  10. Multiferroic properties of Pb{sub 0.90}Sr{sub 0.10}TiO{sub 3}-CoFe{sub 2}O{sub 4} nanostructured bilayered thin film

    SciTech Connect

    Bala, Kanchan Kotnala, R. K.; Negi, N. S.

    2015-05-15

    Pb{sub 0.90}Sr{sub 0.10}TiO{sub 3}-CoFe{sub 2}O{sub 4}(PST10-CFO) nanostructured bilayered thin film were grown on Si (100) substrate by using metallo-organic decomposition chemical route and spin coating technique. Results show that PST (pervoskite structure) and CFO (spinel) phase coexist in the bilayered thin films, annealed at 650°C for 2hr and no obvious impurity phase can be detected. The structural, surface morphology and micro structural properties were confirmed by X-Ray diffraction (XRD), atomic force microscope (AFM) respectively. Excellent ferroelectric behavior at different voltage was observed, with two platinum electrodes only at surface of the bilayer thin film. A room temperature ferromagnetic behavior was observed in the bilayered Pb{sub 0.90}Sr{sub 0.10}TiO{sub 3}-CoFe{sub 2}O{sub 4} nanostructured thin film. The saturation magnetization and variation in coercivity value of the bilayer thin film is lower than that of the pure CFO film in the presence of non ferromagnetic PST layer which is the attributed that the significant coupling between the two phases.

  11. Sub-10 μm grain size, Ba1-xCaxTi0.9Zr0.1O3 (x = 0.10 and x = 0.15) piezoceramics processed using a reduced thermal treatment

    NASA Astrophysics Data System (ADS)

    Reyes-Montero, A.; Pardo, L.; López-Juárez, R.; González, A. M.; Rea-López, S. O.; Cruz, M. P.; Villafuerte-Castrejón, M. E.

    2015-06-01

    The solid-state synthesis of Ba1-xCaxTi0.9Zr0.1O3 (x = 0.10, 0.15) (BCTZ) powder and the processing method of ceramics, by the use of reduced synthesis time and temperature (1250 °C for 2 h), are reported. Homogeneous and dense (≥95%) ceramic microstructures with sub-10 μm grain size were obtained under all sintering conditions. A comparative study of their ferro-piezoelectric properties as a function of sintering temperatures is presented. The study shows the role of the grain size effect for improving both piezoelectric and ferroelectric properties of these materials. With an increase of the sintering temperature, grain growth was promoted; therefore, higher ferro-piezoelectric values were obtained (at 1400 °C, for x = 0.10: d33 = 300 pC/N, {{d}31}=-150 pC/N, kp = 48% for x = 0.15: d33 = 410 pC/N, d31 =-154 pC/N, kp = 50%). In addition, a diffuse phase transition is observed in these BCTZ ceramics with a Curie temperature near 100 °C at 1 kHz.

  12. Spring Snow Depth on Arctic Sea Ice using the IceBridge Snow Depth Product (Invited)

    NASA Astrophysics Data System (ADS)

    Webster, M.; Rigor, I. G.; Nghiem, S. V.; Kurtz, N. T.; Farrell, S. L.

    2013-12-01

    Snow has dual roles in the growth and decay of Arctic sea ice. In winter, it insulates sea ice from colder air temperatures, slowing its growth. From spring into summer, the albedo of snow determines how much insolation is transmitted through the sea ice and into the underlying ocean, ultimately impacting the progression of the summer ice melt. Knowing the snow thickness and distribution are essential for understanding and modeling sea ice thermodynamics and the surface heat budget. Therefore, an accurate assessment of the snow cover is necessary for identifying its impacts in the changing Arctic. This study assesses springtime snow conditions on Arctic sea ice using airborne snow thickness measurements from Operation IceBridge (2009-2012). The 2012 data were validated with coordinated in situ measurements taken in March 2012 during the BRomine, Ozone, and Mercury EXperiment field campaign. We find a statistically significant correlation coefficient of 0.59 and RMS error of 5.8 cm. The comparison between the IceBridge snow thickness product and the 1937, 1954-1991 Soviet drifting ice station data suggests that the snow cover has thinned by 33% in the western Arctic and 44% in the Beaufort and Chukchi Seas. A rudimentary estimation shows that a thinner snow cover in the Beaufort and Chukchi Seas translates to a mid-December surface heat flux as high as 81 W/m2 compared to 32 W/m2. The relationship between the 2009-2012 thinner snow depth distribution and later sea ice freeze-up is statistically significant, with a correlation coefficient of 0.59. These results may help us better understand the surface energy budget in the changing Arctic, and may improve our ability to predict the future state of the sea ice cover.

  13. Intermediate-depth circulation in the Gulf of Mexico estimated from direct measurements

    NASA Astrophysics Data System (ADS)

    Weatherly, Georges L.; Wienders, Nicolas; Romanou, Anastasia

    Data from 17 PALACE floats set in the Gulf of Mexico sampling the intermediate-depth (≈900 dbar) flow from April 1998 to February 2002 indicate a mean cyclonic circulation along the northern and western edges of the Gulf of Mexico. This flow intensified into a ≈0.10 m/s current in the western Bay of Campeche and was deflected around a topographic feature, called here the Campeche Bay Bump, in the southern Bay of Campeche. Floats launched in the eastern Gulf of Mexico tended to stay there, and those launched in the western Gulf tended to stay in the western Gulf, suggesting restricted connection at depth between the eastern and western Gulf of Mexico. Not surprisingly, the measured flow was stronger when the measured flow was under the Loop Current and warm-core rings, but the direction of the intermediated depth currents bore no apparent relation to the surface flow inferred from satellite altimeter maps. However, comparing the floats' surface drifts to their intermediate depth drifts, the floats at depth ended to track the surface flow in the Loop Current, and both indicate a cyclonic gyre in the Bay of Campeche.

  14. A l% and 1cm Perspective Leads to a Novel CDOM Absorption Algorithm

    NASA Technical Reports Server (NTRS)

    Morrow, J. H.; Hooker, S. B.; Matsuoka, A.

    2012-01-01

    A next-generation in-water profiler designed to measure the apparent optical properties of seawater was developed and validated across a wide dynamic range of water properties. This new Compact-Optical Profiling System (C-OPS) design uses a novel, kite-shaped, free-falling backplane with adjustable buoyancy and is based on 19 state-of-the-art microradiometers, spanning 320-780 nm. Data collected as part of the field commissioning were of a previously unachievable quality and showed that systematic uncertainties in the sampling protocols were discernible at the 1% optical and 1cm depth resolution levels. A sensitivity analysis as a function of three water types, established by the peak in the remote sensing reflectance spectra, revealed which water types and spectral domains were the most indicative of data acquisition uncertainties. The unprecedented vertical resolution of C-OPS measurements provided near-surface data products at the spectral endpoints with a quality level that has not been obtainable. The improved data allowed development of an algorithm for predicting the spectral absorption due to chromophoric dissolved organic matter (CDOM) using ratios of diffuse attenuation coefficients with over 99% of the variance in the data explained.

  15. Rooting depth and distributions of deep-rooted plants in the 200 Area control zone of the Hanford Site

    SciTech Connect

    Klepper, E.L.; Gano, K.A.; Cadwell, L.L.

    1985-01-01

    This study was conducted to document rooting depths and distributions of deep-rooted plants common to the Hanford Site 200-Area plateau. The effort concentrated on excavating plant species suspected of having deep root systems, and species that have been reported in previous studies to contain radionuclides in above ground parts. The information obtained in this study will be useful in modeling radionuclide transport by plants and in designing covers and barriers for decommissioning low-level radioactive waste burial sites. Fourteen species including 58 individual plants were excavated to measure maximum rooting depth and root density distribution (g dry root/dm/sup 3/) through the root zone. Age and canopy volumes of shrubs were also determined. Eight of the 14 species excavated had average rooting depths of 150 cm or more. The two deepest rooted plants were antelope bitterbrush and sagebrush with average depths of 296 and 200 cm, respectively. Gray rabbitbrush had an average rooting depth of 183 cm. Summer annuals, Russian thistle and bursage, had average rooting depths of 172 and 162 cm, respectively. 7 references, 4 figures, 5 tables.

  16. Capturing Motion and Depth Before Cinematography.

    PubMed

    Wade, Nicholas J

    2016-01-01

    Visual representations of biological states have traditionally faced two problems: they lacked motion and depth. Attempts were made to supply these wants over many centuries, but the major advances were made in the early-nineteenth century. Motion was synthesized by sequences of slightly different images presented in rapid succession and depth was added by presenting slightly different images to each eye. Apparent motion and depth were combined some years later, but they tended to be applied separately. The major figures in this early period were Wheatstone, Plateau, Horner, Duboscq, Claudet, and Purkinje. Others later in the century, like Marey and Muybridge, were stimulated to extend the uses to which apparent motion and photography could be applied to examining body movements. These developments occurred before the birth of cinematography, and significant insights were derived from attempts to combine motion and depth. PMID:26684420

  17. Capturing Motion and Depth Before Cinematography.

    PubMed

    Wade, Nicholas J

    2016-01-01

    Visual representations of biological states have traditionally faced two problems: they lacked motion and depth. Attempts were made to supply these wants over many centuries, but the major advances were made in the early-nineteenth century. Motion was synthesized by sequences of slightly different images presented in rapid succession and depth was added by presenting slightly different images to each eye. Apparent motion and depth were combined some years later, but they tended to be applied separately. The major figures in this early period were Wheatstone, Plateau, Horner, Duboscq, Claudet, and Purkinje. Others later in the century, like Marey and Muybridge, were stimulated to extend the uses to which apparent motion and photography could be applied to examining body movements. These developments occurred before the birth of cinematography, and significant insights were derived from attempts to combine motion and depth.

  18. Apparent extended body motions in depth

    NASA Technical Reports Server (NTRS)

    Hecht, Heiko; Proffitt, Dennis R.

    1991-01-01

    Five experiments were designed to investigate the influence of three-dimensional (3-D) orientation change on apparent motion. Projections of an orientation-specific 3-D object were sequentially flashed in different locations and at different orientations. Such an occurrence could be resolved by perceiving a rotational motion in depth around an axis external to the object. Consistent with this proposal, it was found that observers perceived curved paths in depth. Although the magnitude of perceived trajectory curvature often fell short of that required for rotational motions in depth (3-D circularity), judgments of the slant of the virtual plane on which apparent motions occurred were quite close to the predictions of a model that proposes circular paths in depth.

  19. Water depth estimation with ERTS-1 imagery

    NASA Technical Reports Server (NTRS)

    Ross, D. S.

    1973-01-01

    Contrast-enhanced 9.5 inch ERTS-1 images were produced for an investigation on ocean water color. Such images lend themselves to water depth estimation by photographic and electronic density contouring. MSS-4 and -5 images of the Great Bahama Bank were density sliced by both methods. Correlation was found between the MSS-4 image and a hydrographic chart at 1:467,000 scale, in a number of areas corresponding to water depth of less than 2 meters, 5 to 10 meters and 10 to about 20 meters. The MSS-5 image was restricted to depths of about 2 meters. Where reflective bottom and clear water are found, ERTS-1 MSS-4 images can be used with density contouring by electronic or photographic methods for estimating depths to 5 meters within about one meter.

  20. Cumulative history recorded in the depth distribution of radiocesium in sediments deposited on a sandbar.

    PubMed

    Tanaka, Kazuya; Kondo, Hiroaki; Sakaguchi, Aya; Takahashi, Yoshio

    2015-12-01

    We collected sediments deposited on a sandbar from the surface to 20 cm in depth in the Abukuma River to clarify the history of radiocesium derived from the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. We analyzed the (137)Cs concentration in the sediments from size-fractioned samples as well as bulk samples. The depth distribution of (137)Cs showed the highest concentration in the deepest sediment layer (18-20 cm) studied, which indicates that sediments with a lower (137)Cs concentration were transported and deposited on sediments having a higher (137)Cs concentration. At the same time, the depth distribution suggests a decrease in radioactivity in provenance areas of the sediments. Analysis of the size-fractioned sediments indicated that the three sediment layers at 4-6 cm, 16-18 cm and 18-20 cm intervals had similar size distribution of (137)Cs and grain size composition although the concentration levels of (137)Cs were different according to their bulk concentrations. The size distribution of (137)Cs also supported the possibility that the decrease in (137)Cs concentration in bulk sediments above 18 cm is due to a decrease in the level of radioactivity in the catchment area. A comparison of the size distribution of (137)Cs between the sediment layers above and below 18 cm suggested that the (137)Cs concentration in the transported fine sediment particles decreased more with time than the (137)Cs concentration in the coarse particles, reflecting the selective transport of the finer particles. The results of this study demonstrated that sediment layers deposited on a sandbar retained the cumulative history of the fluvial transport of radiocesium after the FDNPP accident. PMID:26360256

  1. On the ability of RegCM4 regional climate model to simulate surface solar radiation patterns over Europe: an assessment using satellite-based observations

    NASA Astrophysics Data System (ADS)

    Alexandri, G.; Georgoulias, A. K.; Zanis, P.; Katragkou, E.; Tsikerdekis, A.; Kourtidis, K.; Meleti, C.

    2015-11-01

    In this work, we assess the ability of RegCM4 regional climate model to simulate surface solar radiation (SSR) patterns over Europe. A decadal RegCM4 run (2000-2009) was implemented and evaluated against satellite-based observations from the Satellite Application Facility on Climate Monitoring (CM SAF), showing that the model simulates adequately the SSR patterns over the region. The SSR bias between RegCM4 and CM SAF is +1.5 % for MFG (Meteosat First Generation) and +3.3 % for MSG (Meteosat Second Generation) observations. The relative contribution of parameters that determine the transmission of solar radiation within the atmosphere to the deviation appearing between RegCM4 and CM SAF SSR is also examined. Cloud macrophysical and microphysical properties such as cloud fractional cover (CFC), cloud optical thickness (COT) and cloud effective radius (Re) from RegCM4 are evaluated against data from CM SAF. Generally, RegCM4 underestimates CFC by 24.3 % and Re for liquid/ice clouds by 36.1 %/28.3 % and overestimates COT by 4.3 %. The same procedure is repeated for aerosol optical properties such as aerosol optical depth (AOD), asymmetry factor (ASY) and single-scattering albedo (SSA), as well as other parameters, including surface broadband albedo (ALB) and water vapor amount (WV), using data from MACv1 aerosol climatology, from CERES satellite sensors and from ERA-Interim reanalysis. It is shown here that the good agreement between RegCM4 and satellite-based SSR observations can be partially attributed to counteracting effects among the above mentioned parameters. The potential contribution of each parameter to the RegCM4-CM SAF SSR deviations is estimated with the combined use of the aforementioned data and a~radiative transfer model (SBDART). CFC, COT and AOD are the major determinants of these deviations on a monthly basis; however, the other parameters also play an important role for specific regions and seasons. Overall, for the European domain, CFC, COT and

  2. Variations in bacterial and fungal community composition along the soil depth profiles determined by pyrosequencing

    NASA Astrophysics Data System (ADS)

    Ko, D.; Yoo, G.; Jun, S. C.; Yun, S. T.; Chung, H.

    2015-12-01

    Soil microorganisms play key roles in nutrient cycling, and are distributed throughout the soil profile. Currently, there is little information about the characteristics of the microbial communities along the soil depth because most studies focus on microorganisms inhabiting the soil surface. To better understand the functions and composition of microbial communities and the biogeochemical factors that shape them at different soil depth, we analyzed soil microbial activities and bacterial and fungal community composition in a soil profile of a fallow field located in central Korea. Soil samples were taken using 120-cm soil cores. To analyze the composition of bacterial and fungal communities, barcoded pyrosequnecing analysis of 16S rRNA genes (bacteria) and ITS region (fungi) was conducted. Among the bacterial groups, the abundance of Proteobacteria (38.5, 23.2, 23.3, 26.1 and 17.5%, at 15-, 30-, 60-, 90-, and 120-cm depth, respectively) and Firmicutes (12.8, 11.3, 8.6, 4.3 and 0.4%, at 15-, 30-, 60-, 90-, and 120-cm depth, respectively) decreased with soil depth. On the other hand, the abundance of Ascomycota (51.2, 48.6, 65.7, 46.1, and 45.7%, at 15-, 30-, 60-, 90-, and 120-cm depth, respectively), a dominant fungal group at this site, showed no significant difference along the soil profile. To examine the vertical difference of microbial activities, activity of five extracellular enzymes that take part in cycling of C, N, and P in soil ecosystems, beta-1,4-glucosidase, cellobiohydrolase, beta-1,4-xylosidase, beta-1,4-N-acetylglucosaminidase, and acid phosphatase were analyzed. The soil enzyme activity declined with soil depth. For example, acid phosphatase activity was 88.5 (± 14.6 (± 1 SE)), 30.0 (± 5.9), 18.0 (± 3.5), 14.1 (± 3.7), and 10.7 (± 3.8) nmol g-1 hr-1, at 15-, 30-, 60-, 90-, and 120-cm depth, respectively. These metagenomics studies, along with other studies on microbial functions, are expected to enhance our understanding on the complexity of

  3. Influence of variable topsoil replacement depths on soil chemical parameters within a coal mine in northeastern Wyoming, USA

    SciTech Connect

    Schladweiler, B.K.; Vance, G.F.; Legg, D.E.; Munn, L.C.; Haroian, R.

    2004-10-15

    Uniform topsoil replacement depths on coal mine reclaimed areas have been mandated by USA federal and state regulations; however, soils of the premine landscape are not naturally uniform in depth and vary in physical, chemical, and biological characteristics. In addition, uniform topsoil depths may actually hinder the development of diverse reclaimed plant communities. We studied the effect of varying topsoil replacement depth treatments (15, 30, and 56 cm) on soil and backfill pH, electrolytic conductivity (EC), and sodium adsorption ratio (SAR) within a reclaimed coal mine study area. Backfill material (also known as spoil) at this site did not possess levels of pH, EC, and SAR that were detrimental to plant growth. There was only a slight reduction in pH, EC, and SAR within the upper 15 cm depth in the reclaimed topsoil treatments with a general increase of EC and SAR in the lower portion of the replaced soil profile. Some downward movement of soluble salts within the reclaimed treatments was evident despite low precipitation. For examples, SAR in the 0-15 cm depth over all reclaimed treatments was lower in 2002 than 2000-2001, and the 0-30 cm portion of the reclaimed soil profile had reduced pH and EC, while the 30-60 cm portion had increased EC and SAR. It is anticipated that soil quality differences in terms of pH, EC, and SAR between topsoil depth treatments will be enhanced with time. Comparison of the reclaimed area to the native reference areas suggested numerous depth differences as a result of homogeneity of the replaced topsoil vs. undisturbed soil profiles.

  4. Reference surfaces for bridge scour depths

    USGS Publications Warehouse

    Landers, Mark N.; Mueller, David S.

    1993-01-01

    Depth of scour is measured as the vertical distance between scoured channel geometry and a measurement reference surface. A scour depth measurement can have a wide range depending on the method used to establish the reference surface. A consistent method to establish reference surfaces for bridge scour measurements is needed to facilitate transferability of scour data an scour analyses. This paper describes and evaluates techniques for establishing reference surfaces from which local and contraction scour are measured.

  5. RGB-D depth-map restoration using smooth depth neighborhood supports

    NASA Astrophysics Data System (ADS)

    Liu, Wei; Xue, Haoyang; Yu, Zhongjie; Wu, Qiang; Yang, Jie

    2015-05-01

    A method to restore the depth map of an RGB-D image using smooth depth neighborhood (SDN) supports is presented. The SDN supports are computed based on the corresponding color image of the depth map. Compared with the most widely used square supports, the proposed SDN supports can well-capture the local structure of the object. Only pixels with similar depth values are allowed to be included in the support. We combine our SDN supports with the joint bilateral filter (JBF) to form the SDN-JBF and use it to restore depth maps. Experimental results show that our SDN-JBF can not only rectify the misaligned depth pixels but also preserve sharp depth discontinuities.

  6. Depth-aware image seam carving.

    PubMed

    Shen, Jianbing; Wang, Dapeng; Li, Xuelong

    2013-10-01

    Image seam carving algorithm should preserve important and salient objects as much as possible when changing the image size, while not removing the secondary objects in the scene. However, it is still difficult to determine the important and salient objects that avoid the distortion of these objects after resizing the input image. In this paper, we develop a novel depth-aware single image seam carving approach by taking advantage of the modern depth cameras such as the Kinect sensor, which captures the RGB color image and its corresponding depth map simultaneously. By considering both the depth information and the just noticeable difference (JND) model, we develop an efficient JND-based significant computation approach using the multiscale graph cut based energy optimization. Our method achieves the better seam carving performance by cutting the near objects less seams while removing distant objects more seams. To the best of our knowledge, our algorithm is the first work to use the true depth map captured by Kinect depth camera for single image seam carving. The experimental results demonstrate that the proposed approach produces better seam carving results than previous content-aware seam carving methods. PMID:23893762

  7. Crack depth determination with inductive thermography

    NASA Astrophysics Data System (ADS)

    Oswald-Tranta, B.; Schmidt, R.

    2015-05-01

    Castings, forgings and other steel products are nowadays usually tested with magnetic particle inspection, in order to detect surface cracks. An alternative method is active thermography with inductive heating, which is quicker, it can be well automated and as in this paper presented, even the depth of a crack can be estimated. The induced eddy current, due to its very small penetration depth in ferro-magnetic materials, flows around a surface crack, heating this selectively. The surface temperature is recorded during and after the short inductive heating pulse with an infrared camera. Using Fourier transformation the whole IR image sequence is evaluated and the phase image is processed to detect surface cracks. The level and the local distribution of the phase around a crack correspond to its depth. Analytical calculations were used to model the signal distribution around cracks with different depth and a relationship has been derived between the depth of a crack and its phase value. Additionally, also the influence of the heating pulse duration has been investigated. Samples with artificial and with natural cracks have been tested. Results are presented comparing the calculated and measured phase values depending on the crack depth. Keywords: inductive heating, eddy current, infrared

  8. Molecular depth profiling by wedged crater beveling.

    PubMed

    Mao, Dan; Lu, Caiyan; Winograd, Nicholas; Wucher, Andreas

    2011-08-15

    Time-of-flight secondary ion mass spectrometry and atomic force microscopy are employed to characterize a wedge-shaped crater eroded by a 40-keV C(60)(+) cluster ion beam on an organic film of Irganox 1010 doped with Irganox 3114 delta layers. From an examination of the resulting surface, the information about depth resolution, topography, and erosion rate can be obtained as a function of crater depth for every depth in a single experiment. It is shown that when measurements are performed at liquid nitrogen temperature, a constant erosion rate and reduced bombardment induced surface roughness is observed. At room temperature, however, the erosion rate drops by ∼(1)/(3) during the removal of the 400 nm Irganox film and the roughness gradually increased to from 1 nm to ∼4 nm. From SIMS lateral images of the beveled crater and AFM topography results, depth resolution was further improved by employing glancing angles of incidence and lower primary ion beam energy. Sub-10 nm depth resolution was observed under the optimized conditions on a routine basis. In general, we show that the wedge-crater beveling is an important tool for elucidating the factors that are important for molecular depth profiling experiments.

  9. Performance of scalable coding in depth domain

    NASA Astrophysics Data System (ADS)

    Sjöström, Mårten; Karlsson, Linda S.

    2010-02-01

    Common autostereoscopic 3D displays are based on multi-view projection. The diversity of resolutions and number of views of such displays implies a necessary flexibility of 3D content formats in order to make broadcasting efficient. Furthermore, distribution of content over a heterogeneous network should adapt to an available network capacity. Present scalable video coding provides the ability to adapt to network conditions; it allows for quality, temporal and spatial scaling of 2D video. Scalability for 3D data extends this list to the depth and the view domains. We have introduced scalability with respect to depth information. Our proposed scheme is based on the multi-view-plus-depth format where the center view data are preserved, and side views are extracted in enhancement layers depending on depth values. We investigate the performance of various layer assignment strategies: number of layers, and distribution of layers in depth, either based on equal number of pixels or histogram characteristics. We further consider the consequences to variable distortion due to encoder parameters. The results are evaluated considering their overall distortion verses bit rate, distortion per enhancement layer, as well as visual quality appearance. Scalability with respect to depth (and views) allows for an increased number of quality steps; the cost is a slight increase of required capacity for the whole sequence. The main advantage is, however, an improved quality for objects close to the viewer, even if overall quality is worse.

  10. Depth dependence of vascular fluorescence imaging

    PubMed Central

    Davis, Mitchell A.; Shams Kazmi, S. M.; Ponticorvo, Adrien; Dunn, Andrew K.

    2011-01-01

    In vivo surface imaging of fluorescently labeled vasculature has become a widely used tool for functional brain imaging studies. Techniques such as phosphorescence quenching for oxygen tension measurements and indocyanine green fluorescence for vessel perfusion monitoring rely on surface measurements of vascular fluorescence. However, the depth dependence of the measured fluorescence signals has not been modeled in great detail. In this paper, we investigate the depth dependence of the measured signals using a three-dimensional Monte Carlo model combined with high resolution vascular anatomy. We found that a bulk-vascularization assumption to modeling the depth dependence of the signal does not provide an accurate picture of penetration depth of the collected fluorescence signal in most cases. Instead the physical distribution of microvasculature, the degree of absorption difference between extravascular and intravascular space, and the overall difference in absorption at the excitation and emission wavelengths must be taken into account to determine the depth penetration of the fluorescence signal. Additionally, we found that using targeted illumination can provide for superior surface vessel sensitivity over wide-field illumination, with small area detection offering an even greater amount of sensitivity to surface vasculature. Depth sensitivity can be enhanced by either increasing the detector area or increasing the illumination area. Finally, we see that excitation wavelength and vessel size can affect intra-vessel sampling distribution, as well as the amount of signal that originates from inside the vessel under targeted illumination conditions. PMID:22162824

  11. Motion parallax thresholds for unambiguous depth perception.

    PubMed

    Holmin, Jessica; Nawrot, Mark

    2015-10-01

    The perception of unambiguous depth from motion parallax arises from the neural integration of retinal image motion and extra-retinal eye movement signals. It is only recently that these parameters have been articulated in the form of the motion/pursuit ratio. In the current study, we explored the lower limits of the parameter space in which observers could accurately perform near/far relative depth-sign discriminations for a translating random-dot stimulus. Stationary observers pursued a translating random dot stimulus containing relative image motion. Their task was to indicate the location of the peak in an approximate square-wave stimulus. We measured thresholds for depth from motion parallax, quantified as motion/pursuit ratios, as well as lower motion thresholds and pursuit accuracy. Depth thresholds were relatively stable at pursuit velocities 5-20 deg/s, and increased at lower and higher velocities. The pattern of results indicates that minimum motion/pursuit ratios are limited by motion and pursuit signals, both independently and in combination with each other. At low and high pursuit velocities, depth thresholds were limited by inaccurate pursuit signals. At moderate pursuit velocities, depth thresholds were limited by motion signals.

  12. Depth dose perturbation by a hydrogel fiducial marker in a proton beam.

    PubMed

    Zhang, Miao; Reyhan, Meral; Kim, Leonard H

    2015-01-08

    The purpose of this study was to evaluate proton depth dose perturbation caused by a radio-opaque hydrogel fiducial marker. Electronic proton stopping powers in the hydrogel were calculated for energies 0.5-250 MeV, and Monte Carlo simulations were generated of hydrogel vs. gold markers placed at various water phantom depths in a generic proton beam. Across the studied energy range, the gel/water stopping power ratio was 1.0146 to 1.0160. In the Monte Carlo simulation, the hydrogel marker caused no discernible perturbation of the proton percent depth-dose (PDD) curve. In contrast, the gold marker caused dose reductions of as much as 20% and dose shadowing regions as long as 6.5 cm. In contrast to gold markers, the radio-opaque hydrogel marker causes negligible proton depth dose perturbation. This factor may be taken into consideration for image-guided proton therapy at facilities with suitable imaging modalities.

  13. Accuracy and Resolution of Kinect Depth Data for Indoor Mapping Applications

    PubMed Central

    Khoshelham, Kourosh; Elberink, Sander Oude

    2012-01-01

    Consumer-grade range cameras such as the Kinect sensor have the potential to be used in mapping applications where accuracy requirements are less strict. To realize this potential insight into the geometric quality of the data acquired by the sensor is essential. In this paper we discuss the calibration of the Kinect sensor, and provide an analysis of the accuracy and resolution of its depth data. Based on a mathematical model of depth measurement from disparity a theoretical error analysis is presented, which provides an insight into the factors influencing the accuracy of the data. Experimental results show that the random error of depth measurement increases with increasing distance to the sensor, and ranges from a few millimeters up to about 4 cm at the maximum range of the sensor. The quality of the data is also found to be influenced by the low resolution of the depth measurements. PMID:22438718

  14. Modeling relationships between water table depth and peat soil carbon loss in Southeast Asian plantations

    NASA Astrophysics Data System (ADS)

    Carlson, Kimberly M.; Goodman, Lael K.; May-Tobin, Calen C.

    2015-07-01

    Plantation-associated drainage of Southeast Asian peatlands has accelerated in recent years. Draining exposes the upper peat layer to oxygen, leading to elevated decomposition rates and net soil carbon losses. Empirical studies indicate positive relationships between long-term water table (WT) depth and soil carbon loss rate in peatlands. These correlations potentially enable using WT depth as a proxy for soil carbon losses from peatland plantations. Here, we compile data from published research assessing WT depth and carbon balance in tropical plantations on peat. We model net carbon loss from subsidence studies, as well as soil respiration (heterotrophic and total) from closed chamber studies, as a function of WT depth. WT depth across all 12 studies and 59 sites is 67 ± 20 cm (mean ± standard deviation). Mean WT depth is positively related to net carbon loss, as well as soil respiration rate. Our models explain 45% of net carbon loss variation and 45-63% of soil respiration variation. At a 70 cm WT depth, the subsidence model suggests net carbon loss of 20 tC ha-1 yr-1 (95% confidence interval (CI) 18-22 tC ha-1 yr-1) for plantations drained for >2 yr. Closed chamber-measured total soil respiration at this depth is 20 tC-CO2 ha-1 yr-1 (CI 17-24 tC-CO2 ha-1 yr-1) while heterotrophic respiration is 17 tC-CO2 ha-1 yr-1 (CI 14-20 tC-CO2 ha-1 yr-1), ˜82% of total respiration. While land use is not a significant predictor of soil respiration, WT depths are greater at acacia (75 ± 16 cm) than oil palm (59 ± 15 cm) sample sites. Improved spatio-temporal sampling of the full suite of peat soil carbon fluxes—including fluvial carbon export and organic fertilizer inputs—will clarify multiple mechanisms leading to carbon loss and gain, supporting refined assessments of the global warming potential of peatland drainage.

  15. Cloning of chrysanthemum high-affinity nitrate transporter family (CmNRT2) and characterization of CmNRT2.1.

    PubMed

    Gu, Chunsun; Song, Aiping; Zhang, Xiaoxue; Wang, Haibin; Li, Ting; Chen, Yu; Jiang, Jiafu; Chen, Fadi; Chen, Sumei

    2016-01-01

    The family of NITRATE TRANSPORTER 2 (NRT2) proteins belongs to the high affinity transport system (HATS) proteins which acts at low nitrate concentrations. The relevant gene content of the chrysanthemum genome was explored here by isolating the full length sequences of six distinct CmNRT2 genes. One of these (CmNRT2.1) was investigated at the functional level. Its transcription level was inducible by low concentrations of both nitrate and ammonium. A yeast two hybrid assay showed that CmNRT2.1 interacts with CmNAR2, while a BiFC assay demonstrated that the interaction occurs at the plasma membrane. Arabidopsis thaliana plants heterologously expressing CmNRT2.1 displayed an enhanced rate of labeled nitrogen uptake, suggesting that CmNRT2.1 represents a high affinity root nitrate transporter. PMID:27004464

  16. Physical Mechanisms for Earthquakes at Intermediate Depths

    NASA Astrophysics Data System (ADS)

    Green, H. W.; Green, H. W.

    2001-12-01

    Conventional brittle shear failure it is strongly inhibited by pressure because it relies on local tensile failure. In contrast, plastic flow processes are thermally activated, making them sensitive functions of temperature, but their pressure dependence is only moderate. As a consequence, in Earth, faulting by unassisted brittle failure is probably restricted to depths less than ~ 30 km because the rocks flow at lower stresses than they fracture. To enable faulting at greater depths, mineral reactions must occur that generate a fluid or fluid-like solid that is much weaker than the parent assemblage. Although a variety of plastic instabilities have been and continue to be proposed to explain earthquakes at depth, dehydration embrittlement remains the only experimentally verified faulting mechanism consistent with the pressures and compositions existing at depths of 50-300km within subducting lithosphere. However, low pressure hydrous phases potentially abundant in subducting lithosphere (e.g. chlorite and antigorite) exhibit a temperature maximum in their stability, implying that the bulk volume change at depths of more than 70-100 km. becomes negative, thereby raising questions about mechanical instability upon dehydration. Further, it is now well-accepted that intermediate-depth earthquakes occur within the descending slab (double seismic zones present in several slabs dramatically demonstrate this fact), in conflict with the maximum depth of 10-12 km accepted for hydration of the lithosphere at oceanic spreading centers. Thus, on the one hand these earthquakes may be evidence that hydrous phases exist deep within subducting slabs but on the other hand, a mechanism for hydration to such depths is not known. One possibility is that large earthquakes outboard of trenches break the surface and allow hydration of the fault zone that can later dehydrate to yield earthquakes at depth, but no mechanism is known for pumping H2O into such fault zones to depths of tens of

  17. Assessing potential of vertical average soil moisture (0-40cm) estimation for drought monitoring using MODIS data: a case study

    NASA Astrophysics Data System (ADS)

    Ma, Jianwei; Huang, Shifeng; Li, Jiren; Li, Xiaotao; Song, Xiaoning; Leng, Pei; Sun, Yayong

    2015-12-01

    Soil moisture is an important parameter in the research of hydrology, agriculture, and meteorology. The present study is designed to produce a near real time soil moisture estimation algorithm by linking optical/IR measurements to ground measured soil moisture, and then used to monitoring region drought. It has been found that the Normalized Difference Vegetation Index (NDVI) and Land Surface Temperature (LST) are related to surface soil moisture. Therefore, a relationship between ground measurement soil moisture and NDVI and LST can be developed. Six days' NDVI and LST data calculated from Terra Moderate Resolution Imaging Spectroradiometer (MODIS) of Shandong province during October in 2009 to May in 2010 were combined with ground measured volumetric soil moisture in different depth (10cm, 20cm, 40cm, and mean in vertical (0-40cm)) and different soil type to determine regression relationships at a 1 km scale. Based on the regression relationships, mean volumetric soil moisture in vertical (0-40cm) at 1 km resolution can be calculated over the Shandong province, and then drought maps were obtained. The result shows that significantly relationship exists between the NDVI and LST and soil moisture at different soil depths, and regression relationships are soil type dependent. What is more, the drought monitoring results agree well with actual situation.

  18. Analysis of the biases in the downward shortwave surface flux in the GFDL CM2.1 general circulation model

    NASA Astrophysics Data System (ADS)

    Freidenreich, Stuart M.; Ramaswamy, V.

    2011-04-01

    Simulations of downward shortwave surface fluxes by the coupled Geophysical Fluid Dynamics Laboratory (GFDL) CM2.1 general circulation model are compared against climatology derived from the Baseline Surface Radiation Network (BSRN), Global Energy Balance Archive, and International Satellite Cloud Climatology Project ISCCP-FD data sets. The spatial pattern of the model's biases is evaluated. An investigation is made of how these relate to accompanying biases in total cloud amount and aerosol optical depth and how they affect the surface temperature simulation. Comparing CM2.1's clear-sky fluxes against BSRN site values, for European, Asian, and North American locations, there are underestimates in the direct and overestimates in the diffuse, resulting in underestimates in the total flux. These are related to overestimates of sulfate aerosol optical depth, arising owing to the behavior of the parameterization function for hygroscopic growth of these aerosols at very high relative humidity. Contrastingly, flux overestimate biases at lower latitude locations are associated with underestimates in sea-salt and carbonaceous aerosol amounts. All-sky flux biases consist of underestimates for North America, Eurasia, southern Africa, and northern oceanic regions and overestimates for the Amazon region, equatorial Africa, off the west coast of the Americas, and southern oceanic regions. These biases show strong correlations with cloud amount biases. There are modest correlations of the flux biases with cool surface temperature biases over North America and Eurasia, warm biases over the Amazon region, and cool (warm) biases over the northern (southern) oceanic regions. Analyses assuming nonhygroscopicity illustrate that there is a reduction of surface temperature biases accompanying a reduction of sulfate aerosol optical depth biases, whereas a more significant improvement in the temperature simulation requires refining the model's simulation of cloudiness.

  19. Strain and vacancy cluster behavior of vanadium and tungsten-doped Ba[Zr{sub 0.10}Ti{sub 0.90}]O{sub 3} ceramics

    SciTech Connect

    Moura, F.; Simoes, A. Z.; Cavalcante, L. S.; Zampieri, M.; Varela, J. A.; Longo, E.; Zaghete, M. A.; Simoes, M. L.

    2008-01-21

    Strain and vacancy clusters behavior of polycrystalline vanadium (V) and tungsten (W)-doped Ba[Zr{sub 0.10}Ti{sub 0.90}]O{sub 3}, (BZT:2%V) and (BZT:2%W) ceramics obtained by the mixed oxide method was evaluated. Substitution of V and W reduces the distortion of octahedral clusters, decreasing the Raman modes. Electron paramagnetic resonance data indicate that the addition of dopants leads to defects and symmetry changes in the BZT lattice. Remnant polarization and coercive field are affected by V and W substitution due the electron-relaxation mode. The unipolar strain E curves as a function of electric field reach its maximum value for BZT:2%V and BZT:2%W ceramics.

  20. Synthesis, electrical and thermal properties of Bi{sub 4}V{sub 2−x}Y{sub x}O{sub 11} (x=0.0 and 0.10) ceramics

    SciTech Connect

    Sahu, S. Roy, M.

    2014-04-24

    Polycrystalline ceramic samples of Bi{sub 4}V{sub 2−x}Y{sub x}O{sub 11} (x=0.0 and 0.10) have been synthesized by standard solid state reaction method. The formation of the compounds has been verified by room temperature (RT) X-ray diffraction. The frequency and temperature dependent dielectric constant of both the compounds have been measured. The dielectric studies indicate that the materials are highly lossy. The dc conductivity of the materials has been measured as a function of temperature from RT to 653K and their activation energies were calculated using Arrhenius relation σ = σ{sub o}exp(-Ea/kT). The specific heat and heat flow of both the compounds were determined as a function of temperature using Modulated Differential Scanning Calorimetry (MDSC)

  1. High-Speed Wind-Tunnel Investigation of the Lateral Stability Characteristics of a 0.10-Scale Model of the Grumman XF9F-2 Airplane, TED No. NACA DE 301

    NASA Technical Reports Server (NTRS)

    Polhamus, Edward C.; King, Thomas J., Jr.

    1949-01-01

    An investigation was made in the Langley high-speed 7- by 10-foot tunnel to determine the high-speed lateral and directional stability characteristics of a 0.10-scale model of the Grumman XF9F-2 airplane in the Mach number range from 0.40 to 0.85. The results indicate that static lateral and directional stability is present throughout the Mach number range investigated although in the Mach number range from 0.75 to 0.85 there is an appreciable decrease in rolling moment due to sideslip. Calculations of the dynamic stability indicate that according to current flying-quality requirements the damping of the lateral oscillation, although probably satisfactory for the sea-level condition, may not be satisfactory for the majority of the altitude conditions investigated

  2. Dielectric, ferroelectrics properties and impedance spectroscopy analysis of the [(Na0.535K0.480)0.966Li0.058](Nb0.90Ta0.10)O3-based lead-free ceramics

    NASA Astrophysics Data System (ADS)

    Saidi, M.; Chaouchi, A.; D'Astorg, S.; Rguiti, M.; Courtois, C.

    2015-04-01

    Polycrystalline of [(Na0.535K0.480)0.966Li0.058](Nb0.90Ta0.10)O3 samples were prepared using the high-temperature solid-state reaction technique. X-ray diffraction (XRD) analysis indicates the formation of a single-phase with orthorhombic structure. AC impedance plots were used as tool to analyze the electrical behavior of the sample as a function of frequency at different temperatures. The AC impedance studies revealed the presence of grain effect, from 425°C onwards. Complex impedance analysis indicated non-Debye type dielectric relaxation. The Nyquist plot showed the negative temperature coefficient of resistance (NTCR) characteristic of NKLNT. The AC conductivity results were used to correlate with the barrier hopping (CBH) model to evaluate the binding energy (Wm), the minimum hopping distance (Rmin), the density of states at Fermi level (N(Ef)), and the activation energy of the compound.

  3. Real-time structured light depth extraction

    NASA Astrophysics Data System (ADS)

    Keller, Kurtis; Ackerman, Jeremy D.

    2000-03-01

    Gathering depth data using structured light has been a procedure for many different environments and uses. Many of these system are utilized instead of laser line scanning because of their quickness. However, to utilize depth extraction for some applications, in our case laparoscopic surgery, the depth extraction must be in real time. We have developed an apparatus that speeds up the raw image display and grabbing in structured light depth extraction from 30 frames per second to 60 and 180 frames per second. This results in an updated depth and texture map of about 15 times per second versus about 3. This increased update rate allows for real time depth extraction for use in augmented medical/surgical applications. Our miniature, fist-sized projector utilizes an internal ferro-reflective LCD display that is illuminated with cold light from a flex light pipe. The miniature projector, attachable to a laparoscope, displays inverted pairs of structured light into the body where these images are then viewed by a high-speed camera set slightly off axis from the projector that grabs images synchronously. The images from the camera are ported to a graphics-processing card where six frames are worked on simultaneously to extract depth and create mapped textures from these images. This information is then sent to the host computer with 3D coordinate information of the projector/camera and the associated textures. The surgeon is then able to view body images in real time from different locations without physically moving the laparoscope imager/projector, thereby, reducing the trauma of moving laparoscopes in the patient.

  4. SU-E-T-499: Comparison of Measured Tissue Phantom Ratios (TPR) Against Calculated From Percent Depth Doses (PDD) with and Without Peak Scatter Factor (PSF) in 6MV Open Beam

    SciTech Connect

    Narayanasamy, G; Cruz, W; Gutierrez, Alonso; Mavroidis, Panayiotis; Papanikolaou, N; Stathakis, S; Breton, C

    2014-06-01

    Purpose: To examine the accuracy of measured tissue phantom ratios (TPR) values with TPR calculated from percentage depth dose (PDD) with and without peak scatter fraction (PSF) correction. Methods: For 6MV open beam, TPR and PDD values were measured using PTW Semiflex (31010) ionization field and reference chambers (0.125cc volume) in a PTW MP3-M water tank. PDD curves were measured at SSD of 100cm for 7 square fields from 3cm to 30cm. The TPR values were measured up to 22cm depth for the same fields by continuous water draining method with ionization chamber static at 100cm from source. A comparison study was performed between the (a) measured TPR, (b) TPR calculated from PDD without PSF, (c) TPR calculated from PDD with PSF and (d) clinical TPR from RadCalc (ver 6.2, Sun Nuclear Corp). Results: There is a field size, depth dependence on TPR values. For 10cmx10cm, the differences in surface dose (DDs), dose at 10cm depth (DD10) <0.5%; differences in dmax (Ddmax) <2mm for the 4 methods. The corresponding values for 30cmx30cm are DDs, DD10 <0.2% and Ddmax<3mm. Even though for 3cmx3cm field, DDs and DD10 <1% and Ddmax<1mm, the calculated TPR values with and without PSF correction differed by 2% at >20cm depth. In all field sizes at depths>28cm, (d) clinical TPR values are larger than that from (b) and (c) by >3%. Conclusion: Measured TPR in method (a) differ from calculated TPR in methods (b) and (c) to within 1% for depths < 28cm in all 7 fields in open 6MV beam. The dmax values are within 3mm of each other. The largest deviation of >3% was observed in clinical TPR values in method (d) for all fields at depths < 28cm.

  5. Evaluation of detectors for acquisition of pristine depth-dose curves in pencil beam scanning.

    PubMed

    Bäumer, Christian; Koska, Benjamin; Lambert, Jamil; Timmermann, Beate; Mertens, Thierry; Takoukam Talla, Patrick

    2015-01-01

    Acquisition of quasi-monoenergetic ("pristine") depth-dose curves is an essential task in the frame of commissioning and quality assurance of a proton therapy treatment head. For pencil beam scanning delivery modes this is often accomplished by measuring the integral ionization in a plane perpendicular to the axis of an unscanned beam. We focus on the evaluation of three integral detectors: two of them are plane-parallel ionization chambers with an effective radius of 4.1 cm and 6.0 cm, respectively, mounted in a scanning water phantom. The third integral detector is a 6.0 cm radius multilayer ionization chamber. The experimental results are compared with the corresponding measurements under broad field conditions, which are performed with a small radius plane-parallel chamber and a small radius multilayer ionization chamber. We study how a measured depth-dose curve of a pristine proton field depends on the detection device, by evaluating the shape of the depth-dose curve, the relative charge collection efficiency, and intercomparing measured ranges. Our results show that increasing the radius of an integral chamber from 4.1 cm to 6.0 cm increases the collection efficiency by 0%-3.5% depending on beam energy and depth. Ranges can be determined by the large electrode multilayer ionization chamber with a typical uncertainty of 0.4 mm on a routine basis. The large electrode multilayer ionization chamber exhibits a small distortion in the Bragg Peak region. This prohibits its use for acquisition of base data, but is tolerable for quality assurance. The good range accuracy and the peak distortion are characteristics of the multilayer ionization chamber design, as shown by the direct comparison with the small electrode counterpart.

  6. Effect of soil depth and texture on fecal bacteria removal from septic effluents.

    PubMed

    Karathanasis, A D; Mueller, T G; Boone, B; Thompson, Y L

    2006-09-01

    This study evaluated the effectiveness of soils with different texture and depth to treat fecal bacteria eluted from a house-hold septic effluent. The assessments were accomplished by leaching undisturbed soil monoliths of 30, 45, and 60cm thickness and 25cm in diameter, representing the four different textural groups and hydraulic loadings recommended by the Kentucky Health Department, with domestic wastewater effluent collected regularly from a house-hold septic system. Eluent concentrations were monitored daily over a 15 day period for fecal coliform and fecal streptococci concentrations. The results of the study indicate an alarming frequency of failure to comply with United States Environmental Protection Agency (USEPA) criteria for depth to groundwater, when using a 30 cm vertical separation distance between the bottom of the drain-field and a limiting soil interface. The treatment performance was especially poor in coarse-textured soils. Although biomat development over time is expected to improve treatment, the high influent levels of fecal bacteria pose great concerns for surface and groundwater contamination. Fine-textured soils generally provided better treatment efficiency and more consistent compliance with EPA standards. Treatment efficiency and compliance usually improved with increasing soil depth, with the 60cm thickness providing the most consistent performance and compliance with maximum discharge limit (MDL) requirements. The findings of this study document a general inadequacy of the 30cm vertical separation distance to provide effective treatment of septic effluents in Kentucky soils, particularly in coarse-textured soils. Considering that increasing the soil depth thickness may be impractical in many marginal soils, complementary or alternative treatment technologies should be adopted to improve treatment efficiency and prevent further deterioration of the quality of water resources.

  7. Evaluation of detectors for acquisition of pristine depth-dose curves in pencil beam scanning.

    PubMed

    Bäumer, Christian; Koska, Benjamin; Lambert, Jamil; Timmermann, Beate; Mertens, Thierry; Takoukam Talla, Patrick

    2015-01-01

    Acquisition of quasi-monoenergetic ("pristine") depth-dose curves is an essential task in the frame of commissioning and quality assurance of a proton therapy treatment head. For pencil beam scanning delivery modes this is often accomplished by measuring the integral ionization in a plane perpendicular to the axis of an unscanned beam. We focus on the evaluation of three integral detectors: two of them are plane-parallel ionization chambers with an effective radius of 4.1 cm and 6.0 cm, respectively, mounted in a scanning water phantom. The third integral detector is a 6.0 cm radius multilayer ionization chamber. The experimental results are compared with the corresponding measurements under broad field conditions, which are performed with a small radius plane-parallel chamber and a small radius multilayer ionization chamber. We study how a measured depth-dose curve of a pristine proton field depends on the detection device, by evaluating the shape of the depth-dose curve, the relative charge collection efficiency, and intercomparing measured ranges. Our results show that increasing the radius of an integral chamber from 4.1 cm to 6.0 cm increases the collection efficiency by 0%-3.5% depending on beam energy and depth. Ranges can be determined by the large electrode multilayer ionization chamber with a typical uncertainty of 0.4 mm on a routine basis. The large electrode multilayer ionization chamber exhibits a small distortion in the Bragg Peak region. This prohibits its use for acquisition of base data, but is tolerable for quality assurance. The good range accuracy and the peak distortion are characteristics of the multilayer ionization chamber design, as shown by the direct comparison with the small electrode counterpart. PMID:26699567

  8. In vivo microcirculation imaging of the sub surface fingertip using correlation mapping optical coherence tomography (cmOCT)

    NASA Astrophysics Data System (ADS)

    Dsouza, Roshan I.; Zam, Azhar; Subhash, Hrebesh M.; Larin, Kirill V.; Leahy, Martin

    2013-02-01

    We describe a novel application of correlation mapping optical coherence tomography (cmOCT) for sub-surface fingerprint biometric identification. Fingerprint biometrics including automated fingerprint identification systems, are commonly used to recognise the fingerprint, since they constitute simple, effective and valuable physical evidence. Spoofing of biometric fingerprint devices can be easily done because of the limited information obtained from the surface topography. In order to overcome this limitation a potentially more secure source of information is required for biometric identification applications. In this study, we retrieve the microcirculation map of the subsurface fingertip by use of the cmOCT technique. To increase probing depth of the sub surface microcirculation, an optical clearing agent composed of 75% glycerol in aqueous solution was applied topically and kept in contact for 15 min. OCT intensity images were acquired from commercial research grade swept source OCT system (model OCT1300SS, Thorlabs Inc. USA). A 3D OCT scan of the fingertip was acquired over an area of 5x5 mm using 1024x1024 A-scans in approximately 70 s. The resulting volume was then processed using the cmOCT technique with a 7x7 kernel to provide a microcirculation map. We believe these results will demonstrate an enhanced security level over artificial fingertips. To the best of our knowledge, this is the first demonstration of imaging microcirculation map of the subsurface fingertip.

  9. TRENDS IN ESTIMATED MIXING DEPTH DAILY MAXIMUMS

    SciTech Connect

    Buckley, R; Amy DuPont, A; Robert Kurzeja, R; Matt Parker, M

    2007-11-12

    Mixing depth is an important quantity in the determination of air pollution concentrations. Fireweather forecasts depend strongly on estimates of the mixing depth as a means of determining the altitude and dilution (ventilation rates) of smoke plumes. The Savannah River United States Forest Service (USFS) routinely conducts prescribed fires at the Savannah River Site (SRS), a heavily wooded Department of Energy (DOE) facility located in southwest South Carolina. For many years, the Savannah River National Laboratory (SRNL) has provided forecasts of weather conditions in support of the fire program, including an estimated mixing depth using potential temperature and turbulence change with height at a given location. This paper examines trends in the average estimated mixing depth daily maximum at the SRS over an extended period of time (4.75 years) derived from numerical atmospheric simulations using two versions of the Regional Atmospheric Modeling System (RAMS). This allows for differences to be seen between the model versions, as well as trends on a multi-year time frame. In addition, comparisons of predicted mixing depth for individual days in which special balloon soundings were released are also discussed.

  10. Binocular coordination: reading stereoscopic sentences in depth.

    PubMed

    Schotter, Elizabeth R; Blythe, Hazel I; Kirkby, Julie A; Rayner, Keith; Holliman, Nicolas S; Liversedge, Simon P

    2012-01-01

    The present study employs a stereoscopic manipulation to present sentences in three dimensions to subjects as they read for comprehension. Subjects read sentences with (a) no depth cues, (b) a monocular depth cue that implied the sentence loomed out of the screen (i.e., increasing retinal size), (c) congruent monocular and binocular (retinal disparity) depth cues (i.e., both implied the sentence loomed out of the screen) and (d) incongruent monocular and binocular depth cues (i.e., the monocular cue implied the sentence loomed out of the screen and the binocular cue implied it receded behind the screen). Reading efficiency was mostly unaffected, suggesting that reading in three dimensions is similar to reading in two dimensions. Importantly, fixation disparity was driven by retinal disparity; fixations were significantly more crossed as readers progressed through the sentence in the congruent condition and significantly more uncrossed in the incongruent condition. We conclude that disparity depth cues are used on-line to drive binocular coordination during reading.

  11. Using a fixed-wing UAS to map snow depth distribution: an evaluation at peak accumulation

    NASA Astrophysics Data System (ADS)

    De Michele, Carlo; Avanzi, Francesco; Passoni, Daniele; Barzaghi, Riccardo; Pinto, Livio; Dosso, Paolo; Ghezzi, Antonio; Gianatti, Roberto; Della Vedova, Giacomo

    2016-03-01

    We investigate snow depth distribution at peak accumulation over a small Alpine area ( ˜ 0.3 km2) using photogrammetry-based surveys with a fixed-wing unmanned aerial system (UAS). These devices are growing in popularity as inexpensive alternatives to existing techniques within the field of remote sensing, but the assessment of their performance in Alpine areas to map snow depth distribution is still an open issue. Moreover, several existing attempts to map snow depth using UASs have used multi-rotor systems, since they guarantee higher stability than fixed-wing systems. We designed two field campaigns: during the first survey, performed at the beginning of the accumulation season, the digital elevation model of the ground was obtained. A second survey, at peak accumulation, enabled us to estimate the snow depth distribution as a difference with respect to the previous aerial survey. Moreover, the spatial integration of UAS snow depth measurements enabled us to estimate the snow volume accumulated over the area. On the same day, we collected 12 probe measurements of snow depth at random positions within the case study to perform a preliminary evaluation of UAS-based snow depth. Results reveal that UAS estimations of point snow depth present an average difference with reference to manual measurements equal to -0.073 m and a RMSE equal to 0.14 m. We have also explored how some basic snow depth statistics (e.g., mean, standard deviation, minima and maxima) change with sampling resolution (from 5 cm up to ˜ 100 m): for this case study, snow depth standard deviation (hence coefficient of variation) increases with decreasing cell size, but it stabilizes for resolutions smaller than 1 m. This provides a possible indication of sampling resolution in similar conditions.

  12. Estimating direction and depth of visual fixation using electrooculography.

    PubMed

    Stevenson, Cory; Tzyy-Ping Jung; Cauwenberghs, Gert

    2015-08-01

    Eye tracking is a useful method of human-computer interaction and of interest to scientific studies on cognition. An electrooculogram (EOG), measuring the changes caused by the angular rotation of the dipole moment of the eyes, contains information on the direction of each eye's movement. A known target stimulus moving in 3D space was used to calibrate an 8-channel EOG to resolve the target position and fixation depth. Linear estimations of target position, valid for small-angle deflections from center, resulted in average azimuth (horizontal) and elevation (vertical) angle errors of 2.9±2.1 and 4.4±3.3 degrees, respectively, and average fixation distance errors of 13.4±11.8%(7.5±5.6 cm). Accounting for nonlinearities from wider angles and closer fixations, estimations by a single layer, feedforward neural network, resulted in average errors for azimuth and elevation angle of 2.3±1.6 and 3.2±2.6 degrees, and average fixation distance error of 10.3±10.0% (5.7±4.7 cm). This work is the first apparent demonstration of EOG signals as a basis for eye tracking in 3D. PMID:26736393

  13. Development of cold neutron depth profiling system at HANARO

    NASA Astrophysics Data System (ADS)

    Park, B. G.; Sun, G. M.; Choi, H. D.

    2014-07-01

    A neutron depth profiling (NDP) system has been designed and developed at HANARO, a 30 MW research reactor at the Korea Atomic Energy Research Institute (KAERI). The KAERI-NDP system utilizes cold neutrons that are transported along the CG1 neutron guide from the cold neutron source and it consists of a neutron beam collimator, a target chamber, a beam stopper, and charged particle detectors along with NIM-standard modules for charged particle pulse-height analysis. A 60 cm in diameter stainless steel target chamber was designed to control the positions of the sample and detector. The energy distribution of the cold neutron beam at the end of the neutron guide was calculated by using the Monte Carlo simulation code McStas, and a neutron flux of 1.8×108 n/cm2 s was determined by using the gold foil activation method at the sample position. The performance of the charged particle detection of the KAERI-NDP system was tested by using Standard Reference Materials. The energy loss spectra of alpha particles and Li ions emitted from 10B, which was irradiated by cold neutrons, were measured. The measured peak concentration and the areal density of 10B in the Standard Reference Material are consistent with the reference values within 1% and 3.4%, respectively.

  14. Implication of Land Use and Belowground Weather on Nitrous Oxide Soil Depth Profiles and Denitrification Potential

    NASA Astrophysics Data System (ADS)

    Phillips, R. L.; Song, B.; Saliendra, N.; Liebig, M. A.

    2013-12-01

    Agricultural soils are the largest single source of anthropogenic nitrous oxide (N2O) to the atmosphere, which is largely attributed to the expansion in the use of synthetic fertilizer nitrogen (N). Alfalfa crops often do not require synthetic N addition because N is fixed symbiotically belowground. Some biologically fixed N leaks into soil, which could affect production and consumption of N2O. While many studies have reported net fluxes of N2O at the soil surface, few have quantified variation in N2O concentration at multiple soil depths under variable climatic conditions without synthetic N inputs. A no-till crop field, seeded to alfalfa (Medicago sativa) in 2009, was compared to neighboring native prairie in North Dakota, U.S.A. to determine if N2O, CO2 and CH4 concentrations varied with depth between fields for 4 years. Both fields (> 15 ha) were harvested for hay without N-fertilizer inputs between 2009 and 2013. Soils and instrumentation were similar. Sensors and soil gas well collection chambers were buried at near-surface (15 and 30 cm) and sub-surface (60 and 90 cm) soil depths. Temperature, moisture, oxygen, relative humidity, and pressure data were collected every 30 minutes, and gas well concentration data were collected twice weekly until spring 2013. Cores were collected for each depth increment in 2012, and potential rates of denitrification and anammox were measured for the 0-15 cm depth using soil slurry incubation experiments with 15N tracer treatments. We evaluated temporal variability in N2O concentration with depth and found N2O spikes beneath alfalfa tended to be an order of magnitude higher and more persistent than N2O peaks beneath prairie. Median N2O concentrations at sub-surface depths were greater than near-surface depths. Alfalfa median N2O concentrations for near-surface (24 nmols N2O L-1) and sub-soils (30 nmols N2O L-1) were higher than N2O concentrations beneath prairie (15 nmols N2O L-1 and 17 nmols N2O L-1, respectively). Soil

  15. Depth of the biologically active zone in upland habitats at the Hanford Site, Washington: Implications for remediation and ecological risk management.

    PubMed

    Sample, Bradley E; Lowe, John; Seeley, Paul; Markin, Melanie; McCarthy, Chris; Hansen, Jim; Aly, Alaa H

    2015-01-01

    Soil invertebrates, mammals, and plants penetrate and exploit the surface soil layer (i.e., the biologically active zone) to varying depths. As the US Department of Energy remediates radioactive and hazardous wastes in soil at the Hanford Site, a site-specific definition of the biologically active zone is needed to identify the depth to which remedial actions should be taken to protect the environment and avoid excessive cleanup expenditures. This definition may then be considered in developing a point of compliance for remediation in accordance with existing regulations. Under the State of Washington Model Toxic Control Act (MTCA), the standard point of compliance for soil cleanup levels with unrestricted land use is 457 cm (15 ft) below ground surface. When institutional controls are required to control excavations to protect people, MTCA allows a conditional point of compliance to protect biological resources based on the depth of the biologically active zone. This study was undertaken to identify and bound the biologically active zone based on ecological resources present at the Hanford Site. Primary data were identified describing the depths to which ants, mammals, and plants may exploit the surface soil column at the Hanford Site and other comparable locations. The maximum depth observed for harvester ants (Pogonomyrmex spp.) was 270 cm (8.9 ft), with only trivial excavation below 244 cm (8 ft). Badgers (Taxidea taxus) are the deepest burrowing mammal at the Hanford Site, with maximum burrow depths of 230 cm (7.6 ft); all other mammals did not burrow below 122 cm (4 ft). Shrubs are the deepest rooting plants with rooting depths to 300 cm (9.8 ft) for antelope bitterbrush (Purshia tridentata). The 2 most abundant shrub species did not have roots deeper than 250 cm (8.2 ft). The deepest rooted forb had a maximum root depth of 240 cm (7.9 ft). All other forbs and grasses had rooting depths of 200 cm (6.6 ft) or less. These data indicate that the biologically

  16. Depth of the biologically active zone in upland habitats at the Hanford Site, Washington: Implications for remediation and ecological risk management.

    PubMed

    Sample, Bradley E; Lowe, John; Seeley, Paul; Markin, Melanie; McCarthy, Chris; Hansen, Jim; Aly, Alaa H

    2015-01-01

    Soil invertebrates, mammals, and plants penetrate and exploit the surface soil layer (i.e., the biologically active zone) to varying depths. As the US Department of Energy remediates radioactive and hazardous wastes in soil at the Hanford Site, a site-specific definition of the biologically active zone is needed to identify the depth to which remedial actions should be taken to protect the environment and avoid excessive cleanup expenditures. This definition may then be considered in developing a point of compliance for remediation in accordance with existing regulations. Under the State of Washington Model Toxic Control Act (MTCA), the standard point of compliance for soil cleanup levels with unrestricted land use is 457 cm (15 ft) below ground surface. When institutional controls are required to control excavations to protect people, MTCA allows a conditional point of compliance to protect biological resources based on the depth of the biologically active zone. This study was undertaken to identify and bound the biologically active zone based on ecological resources present at the Hanford Site. Primary data were identified describing the depths to which ants, mammals, and plants may exploit the surface soil column at the Hanford Site and other comparable locations. The maximum depth observed for harvester ants (Pogonomyrmex spp.) was 270 cm (8.9 ft), with only trivial excavation below 244 cm (8 ft). Badgers (Taxidea taxus) are the deepest burrowing mammal at the Hanford Site, with maximum burrow depths of 230 cm (7.6 ft); all other mammals did not burrow below 122 cm (4 ft). Shrubs are the deepest rooting plants with rooting depths to 300 cm (9.8 ft) for antelope bitterbrush (Purshia tridentata). The 2 most abundant shrub species did not have roots deeper than 250 cm (8.2 ft). The deepest rooted forb had a maximum root depth of 240 cm (7.9 ft). All other forbs and grasses had rooting depths of 200 cm (6.6 ft) or less. These data indicate that the biologically

  17. Attachment for sucker rod depth adjustment

    SciTech Connect

    Collins, N.D.

    1992-04-07

    This patent describes a surface unit of an oil well pumping system, having a walking beam, a suspended carrier bar and an interconnected sucker rod assembly for stroking a reciprocating down-hole pump. It comprises a cross bar having a centrally located passage therein for the sucker rod assembly and adapted to be transversely supported by the carrier bar; a depth adjusting bar, having a centrally located passage therein for the sucker rod assembly, positioned at a selected fixed dimension above and parallel to the cross bar and adapted to operatively support the sucker rod assembly; clamping means for fixing the sucker rod relative to the depth adjusting bar; and hydraulically extendable means supportively connecting the depth adjusting bar to the cross bar on at least each side of the carrier bar for adjusting the selected fixed dimension and maintaining the adjustment during operation.

  18. Eye movements in depth to visual illusions

    NASA Astrophysics Data System (ADS)

    Wismeijer, D. A.

    2009-10-01

    We perceive the three-dimensional (3D) environment that surrounds us with deceptive effortlessness. In fact, we are far from comprehending how the visual system provides us with this stable perception of the (3D) world around us. This thesis will focus on the interplay between visual perception of depth and its closely related action system, eye movements in depth. The human visual system is comprised of a sensory (input) and an output (motor) system. Processed information from the sensory system can result in two explicit measurable response types: conscious visual perception and ocular motor behavior. It is still a matter of debate whether conscious visual perception and action (including hand- and arm-movements) use the same information or whether the visual system has separate channels processing information for perception and action. In this thesis, we study (1) if separate channels, one for eye movements and one for conscious visual perception, indeed exist, and (2) if so, if there is a direct input from the perceptual pathway to the motor pathway. Assuming that either eye movements and conscious visual perception are based on information from a common source (a negative answer to issue 1) or perception can directly influence, or guide, eye movements (an affirmative answer to research question 2), (eye) movements reflect our conscious visual perception. If so, eye movements could provide us with an alternative method to probe our conscious visual perception, making explicit perceptual reports superfluous. In this thesis we focus on depth perception and the two types of eye movements that are closest related to depth perception, namely vergence (an eye movement that gets a certain depth plane into focus) and saccades (a rapid eye movement to change gaze direction). Over the last 20 years it has been shown that depth perception is based on a weighted combination of depth cues available such as linear perspective, occlusion and binocular disparity. How eye

  19. Depth profile characterization with noncollinear beam mixing

    SciTech Connect

    Freed, Shaun L. E-mail: jeong.na@wyle.com; Na, Jeong K. E-mail: jeong.na@wyle.com

    2015-03-31

    Noncollinear beam mixing is an ultrasonic approach to quantify elastic nonlinearity within a subsurface volume of material. The technique requires interaction between two beams of specific frequency, angle, and vibration mode to generate a third beam propagating from the intersection volume. The subsurface depth to interaction zone is controlled by changing the separation distance between the two input transducers, and the amplitude of the third generated beam is proportional to the elastic nonlinearity within the interaction zone. Therefore, depth profiling is possible if a suitable parameter is established to normalize the detected signal independent of propagation distances and input amplitudes. This foundational effort has been conducted toward developing such a parameter for depth profile measurements in homogeneous aluminum that includes corrective terms for attenuation, beam overlap noise, beam spread, and input amplitudes. Experimental and analytical results are provided, and suggested applications and improvements are discussed toward characterizing subsurface material property profiles.

  20. Depth-optimized reversible circuit synthesis

    NASA Astrophysics Data System (ADS)

    Arabzadeh, Mona; Saheb Zamani, Morteza; Sedighi, Mehdi; Saeedi, Mehdi

    2013-04-01

    In this paper, simultaneous reduction of circuit depth and synthesis cost of reversible circuits in quantum technologies with limited interaction is addressed. We developed a cycle-based synthesis algorithm which uses negative controls and limited distance between gate lines. To improve circuit depth, a new parallel structure is introduced in which before synthesis a set of disjoint cycles are extracted from the input specification and distributed into some subsets. The cycles of each subset are synthesized independently on different sets of ancillae. Accordingly, each disjoint set can be synthesized by different synthesis methods. Our analysis shows that the best worst-case synthesis cost of reversible circuits in the linear nearest neighbor architecture is improved by the proposed approach. Our experimental results reveal the effectiveness of the proposed approach to reduce cost and circuit depth for several benchmarks.

  1. Depth-size tradeoffs for neural computation

    NASA Technical Reports Server (NTRS)

    Siu, Kai-Yeung; Roychowdhury, Vwani P.; Kailath, Thomas

    1991-01-01

    The tradeoffs between the depth (i.e., the time for parallel computation) and the size (i.e., the number of threshold gates) in neural networks are studied. The authors focus the study on the neural computations of symmetric Boolean functions and some arithmetic functions. It is shown that a significant reduction in the size is possible for symmetric functions and some arithmetic functions, at the expense of a small constant increase in depth. In the process, several neural networks which have the minimum size among all the known constructions have been developed. Results on implementing symmetric functions can be used to improve results about arbitrary Boolean functions. In particular, It is shown that any Boolean function can be computed in a depth-3 neural network with O(2n/2) threshold gates; it is also proven that a minimum number of threshold gates are required.

  2. Fe and O EELS Studies of Ion Irradiated Murchison CM2 Carbonaceous Chondrite Matrix

    NASA Technical Reports Server (NTRS)

    Keller, L. P.; Christofferson, R.; Dukes, C. A.; Baragiola, R. A.; Rahman, Z.

    2015-01-01

    Introduction: The physical and chemical response of hydrated carbonaceous chondrite materials to space weathering processes is poorly understood. Improving this understanding is a key part of establishing how regoliths on primitive carbonaceous asteroids respond to space weathering processes, knowledge that supports future sample return missions (Hayabusa 2 and OSIRISREx) that are targeting objects of this type. We previously reported on He+ irradiation of Murchison matrix and showed that the irradiation resulted in amorphization of the matrix phyllosilicates, loss of OH, and surface vesiculation. Here, we report electron energy-loss spectroscopy (EELS) measurements of the irradiated material with emphasis on the Fe and O speciation. Sample and Methods: A polished thin section of the Murchison CM2 carbonaceous chondrite was irradiated with 4 kilovolts He(+) (normal incidence) to a total dose of 1 x 10(exp 18) He(+) per square centimeter. We extracted thin sections from both irradiated and unirradiated regions in matrix using focused ion beam (FIB) techniques with electron beam deposition for the protective carbon strap to minimize surface damage artifacts from the FIB milling. The FIB sections were analyzed using a JEOL 2500SE scanning and transmission electron microscope (STEM) equipped with a Gatan Tridiem imaging filter. EELS spectra were collected from 50 nanometer diameter regions with an energy resolution of 0.7 electronvolts FWHM at the zero loss. EELS spectra were collected at low electron doses to minimize possible artifacts from electron-beam irradiation damage. Results and Discussion: Fe L (sub 2,3) EELS spectra from matrix phyllosilicates in CM chondrites show mixed Fe(2+)/Fe(3+) oxidation states with Fe(3+)/Sigma Fe approximately 0.5. Fe L(sub 2,3) spectra from the irradiated/ amorphized matrix phyllosilicates show higher Fe(2+)/Fe(3+) ratios compared to spectra obtained from pristine material at depths beyond the implantation/amorphization layer. We

  3. Binocular disparity magnitude affects perceived depth magnitude despite inversion of depth order.

    PubMed

    Matthews, Harold; Hill, Harold; Palmisano, Stephen

    2011-01-01

    The hollow-face illusion involves a misperception of depth order: our perception follows our top-down knowledge that faces are convex, even though bottom-up depth information reflects the actual concave surface structure. While pictorial cues can be ambiguous, stereopsis should unambiguously indicate the actual depth order. We used computer-generated stereo images to investigate how, if at all, the sign and magnitude of binocular disparities affect the perceived depth of the illusory convex face. In experiment 1 participants adjusted the disparity of a convex comparison face until it matched a reference face. The reference face was either convex or hollow and had binocular disparities consistent with an average face or had disparities exaggerated, consistent with a face stretched in depth. We observed that apparent depth increased with disparity magnitude, even when the hollow faces were seen as convex (ie when perceived depth order was inconsistent with disparity sign). As expected, concave faces appeared flatter than convex faces, suggesting that disparity sign also affects perceived depth. In experiment 2, participants were presented with pairs of real and illusory convex faces. In each case, their task was to judge which of the two stimuli appeared to have the greater depth. Hollow faces with exaggerated disparities were again perceived as deeper. PMID:22132512

  4. A new world survey expression for cosmic ray vertical intensity vs. depth in standard rock

    NASA Technical Reports Server (NTRS)

    Crouch, M.

    1985-01-01

    The cosmic ray data on vertical intensity versus depth below 10 to the 5th power g sq cm is fitted to a 5 parameter empirical formula to give an analytical expression for interpretation of muon fluxes in underground measurements. This expression updates earlier published results and complements the more precise curves obtained by numerical integration or Monte Carlo techniques in which the fit is made to an energy spectrum at the top of the atmosphere. The expression is valid in the transitional region where neutrino induced muons begin to be important, as well as at great depths where this component becomes dominant.

  5. Moho depth and age in southern Norway

    NASA Astrophysics Data System (ADS)

    Stratford, W.; Thybo, H.

    2010-05-01

    Moho ages beneath the Fennoscandian shield are highly variable due to the method of crustal accretion and to the long history of extensional and compressional tectonics. In southern Norway, the Moho and crust are inferred to be the youngest of the shield, however, it is likely that a large discrepancy between crustal age and Moho age exists beneath the high southern scandes where the Caledonian orogeny was in effect. Moho structure in southern Norway was targeted recently with a seismic refraction study (Magnus-Rex - Mantle investigations of Norwegian uplift Structure, refraction experiment). Three ~400 km long active source seismic profiles across the high southern Scandes Mountains, the youngest section of the Fennoscandian shield were recorded. Moho depths beneath the high mountains are 36-40 km, thinning towards the Atlantic Margin and the Oslo graben. A new Moho depth map is constructed for southern Norway by compiling new depth measurements with previous refraction Moho measurements. Gaining better constraint on Moho depths in this area is timely, as debate over the source of support for the mountains has provided the impetus for a new focus project, TopoScandesdeep, to find the depth and mechanisms of compensation. P and S-wave arrivals were recorded in the Magnus-Rex project, from which Poisson ratios for the crust in southern Norway are calculated. Unusually strong S-wave arrivals allow rare insight into crustal Poisson's ratio structure that is not normally available from active source data and are usually determined by earthquake tomography studies where only bulk crustal values are available. An average Poisson's ratio of 0.25 is calculated for the crust in southern Norway, suggesting it is predominantly of felsic-intermediate composition and lacks any significant mafic lower crust. This differs significantly from the adjacent crust in the Svecofennian domain of the Fennoscandian shield where Moho depths reach ~50 km and an up to 20 km thick mafic lower

  6. Depth selective acousto-optic flow measurement

    PubMed Central

    Tsalach, Adi; Schiffer, Zeev; Ratner, Eliahu; Breskin, Ilan; Zeitak, Reuven; Shechter, Revital; Balberg, Michal

    2015-01-01

    Optical based methods for non-invasive measurement of regional blood flow tend to incorrectly assess cerebral blood flow, due to contribution of extra-cerebral tissues to the obtained signal. We demonstrate that spectral analysis of phase-coded light signals, tagged by specific ultrasound patterns, enables differentiation of flow patterns at different depths. Validation of the model is conducted by Monte Carlo simulation. In-vitro experiments demonstrate good agreement with the simulations' results and provide a solid validation to depth discrimination ability. These results suggest that signal contamination originating from extra-cerebral tissue may be eliminated using spectral analysis of ultrasonically tagged light. PMID:26713201

  7. Magnetic depth profiles by neutron reflection

    SciTech Connect

    Felcher, G.P.; Gray, K.E.; Kampwirth, R.T.; Brodsky, M.B.

    1985-09-01

    Fresnel reflection of polarized neutrons was used to measure the dependence of magnetic induction B in materials as a function of depth from the surface. The penetration depth of a magnetic field is superconductors was investigated, as well as the remnant superconducting surface sheath when the applied field exceeded the critical value (H/sub c2/ < H < H/sub c3/ in type II superconductors). In addition ferromagnets in bulk and in thin layers were examined. The prototype instrument with which the measurements were made was described. 19 refs., 5 figs. (WRF)

  8. Depth selective acousto-optic flow measurement.

    PubMed

    Tsalach, Adi; Schiffer, Zeev; Ratner, Eliahu; Breskin, Ilan; Zeitak, Reuven; Shechter, Revital; Balberg, Michal

    2015-12-01

    Optical based methods for non-invasive measurement of regional blood flow tend to incorrectly assess cerebral blood flow, due to contribution of extra-cerebral tissues to the obtained signal. We demonstrate that spectral analysis of phase-coded light signals, tagged by specific ultrasound patterns, enables differentiation of flow patterns at different depths. Validation of the model is conducted by Monte Carlo simulation. In-vitro experiments demonstrate good agreement with the simulations' results and provide a solid validation to depth discrimination ability. These results suggest that signal contamination originating from extra-cerebral tissue may be eliminated using spectral analysis of ultrasonically tagged light. PMID:26713201

  9. Depth estimation using a lightfield camera

    NASA Astrophysics Data System (ADS)

    Roper, Carissa

    The latest innovation to camera design has come in the form of the lightfield, or plenoptic, camera that captures 4-D radiance data rather than just the 2-D scene image via microlens arrays. With the spatial and angular light ray data now recorded on the camera sensor, it is feasible to construct algorithms that can estimate depth of field in different portions of a given scene. There are limitations to the precision due to hardware structure and the sheer number of scene variations that can occur. In this thesis, the potential of digital image analysis and spatial filtering to extract depth information is tested on the commercially available plenoptic camera.

  10. Atmospheric Ar and Ne returned from mantle depths to the Earth's surface by forearc recycling.

    PubMed

    Baldwin, Suzanne L; Das, J P

    2015-11-17

    In subduction zones, sediments, hydrothermally altered lithosphere, fluids, and atmospheric gases are transported into the mantle, where ultrahigh-pressure (UHP) metamorphism takes place. However, the extent to which atmospheric noble gases are trapped in minerals crystallized during UHP metamorphism is unknown. We measured Ar and Ne trapped in phengite and omphacite from the youngest known UHP terrane on Earth to determine the composition of Ar and Ne returned from mantle depths to the surface by forearc recycling. An (40)Ar/(39)Ar age [7.93 ± 0.10 My (1σ)] for phengite is interpreted as the timing of crystallization at mantle depths and indicates that (40)Ar/(39)Ar phengite ages reliably record the timing of UHP metamorphism. Both phengite and omphacite yielded atmospheric (38)Ar/(36)Ar and (20)Ne/(22)Ne. Our study provides the first documentation, to our knowledge, of entrapment of atmospheric Ar and Ne in phengite and omphacite. Results indicate that a subduction barrier for atmospheric-derived noble gases does not exist at mantle depths associated with UHP metamorphism. We show that the crystallization age together with the isotopic composition of nonradiogenic noble gases trapped in minerals formed during subsolidus crystallization at mantle depths can be used to unambiguously assess forearc recycling of atmospheric noble gases. The flux of atmospheric noble gas entering the deep Earth through subduction and returning to the surface cannot be fully realized until the abundances of atmospheric noble gases trapped in exhumed UHP rocks are known. PMID:26542683

  11. Intermediate-Depth Currents Estimated From Float Measurements in the Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Weatherly, G. L.; Wienders, N.; Romano, A.

    2005-05-01

    Data from 17 PALACE floats set in the Gulf of Mexico sampling the intermediate-depth (~ 900 db) flow from April 1998 to February 2002 indicate a mean cyclonic circulation along the northern, western and southwestern edges of the Gulf of Mexico. This flow intensified into a ~ 0.10 m/s current in the western and southern Bay of Campeche and was deflected around a topographic feature, called here the Campeche Bay Bump, in the southern Bay of Campeche. Associated with this intensified flow was a small cyclonic gyre in the southwestern Bay of Campeche. Floats launched in the eastern Gulf of Mexico tended to stay there and those launched in the western Gulf of Mexico tended to stay in the western Gulf of Mexico suggesting restricted connection at depth between the eastern and western Gulf of Mexico. The current estimates made neglecting non-900 db depth drifts before first-surface fix and drifts after last-surface fix were 10% larger than those which took into account these drifts. Most of this (8%) was due to neglect of the surface drift before first and after last fix. Except for stronger flow below the Loop Current and Loop Current warm-core rings, no other pattern was seen between the intermediate depth flow and the surface flow.

  12. Atmospheric Ar and Ne returned from mantle depths to the Earth's surface by forearc recycling.

    PubMed

    Baldwin, Suzanne L; Das, J P

    2015-11-17

    In subduction zones, sediments, hydrothermally altered lithosphere, fluids, and atmospheric gases are transported into the mantle, where ultrahigh-pressure (UHP) metamorphism takes place. However, the extent to which atmospheric noble gases are trapped in minerals crystallized during UHP metamorphism is unknown. We measured Ar and Ne trapped in phengite and omphacite from the youngest known UHP terrane on Earth to determine the composition of Ar and Ne returned from mantle depths to the surface by forearc recycling. An (40)Ar/(39)Ar age [7.93 ± 0.10 My (1σ)] for phengite is interpreted as the timing of crystallization at mantle depths and indicates that (40)Ar/(39)Ar phengite ages reliably record the timing of UHP metamorphism. Both phengite and omphacite yielded atmospheric (38)Ar/(36)Ar and (20)Ne/(22)Ne. Our study provides the first documentation, to our knowledge, of entrapment of atmospheric Ar and Ne in phengite and omphacite. Results indicate that a subduction barrier for atmospheric-derived noble gases does not exist at mantle depths associated with UHP metamorphism. We show that the crystallization age together with the isotopic composition of nonradiogenic noble gases trapped in minerals formed during subsolidus crystallization at mantle depths can be used to unambiguously assess forearc recycling of atmospheric noble gases. The flux of atmospheric noble gas entering the deep Earth through subduction and returning to the surface cannot be fully realized until the abundances of atmospheric noble gases trapped in exhumed UHP rocks are known.

  13. Probing reionization with the cross-power spectrum of 21 cm and near-infrared radiation backgrounds

    SciTech Connect

    Mao, Xiao-Chun

    2014-08-01

    The cross-correlation between the 21 cm emission from the high-redshift intergalactic medium and the near-infrared (NIR) background light from high-redshift galaxies promises to be a powerful probe of cosmic reionization. In this paper, we investigate the cross-power spectrum during the epoch of reionization. We employ an improved halo approach to derive the distribution of the density field and consider two stellar populations in the star formation model: metal-free stars and metal-poor stars. The reionization history is further generated to be consistent with the electron-scattering optical depth from cosmic microwave background measurements. Then, the intensity of the NIR background is estimated by collecting emission from stars in first-light galaxies. On large scales, we find that the 21 cm and NIR radiation backgrounds are positively correlated during the very early stages of reionization. However, these two radiation backgrounds quickly become anti-correlated as reionization proceeds. The maximum absolute value of the cross-power spectrum is |Δ{sub 21,NIR}{sup 2}|∼10{sup −4} mK nW m{sup –2} sr{sup –1}, reached at ℓ ∼ 1000 when the mean fraction of ionized hydrogen is x-bar{sub i}∼0.9. We find that Square Kilometer Array can measure the 21 cm-NIR cross-power spectrum in conjunction with mild extensions to the existing CIBER survey, provided that the integration time independently adds up to 1000 and 1 hr for 21 cm and NIR observations, and that the sky coverage fraction of the CIBER survey is extended from 4 × 10{sup –4} to 0.1. Measuring the cross-correlation signal as a function of redshift provides valuable information on reionization and helps confirm the origin of the 'missing' NIR background.

  14. GIANT METREWAVE RADIO TELESCOPE DETECTION OF TWO NEW H I 21 cm ABSORBERS AT z ≈ 2

    SciTech Connect

    Kanekar, N.

    2014-12-20

    I report the detection of H I 21 cm absorption in two high column density damped Lyα absorbers (DLAs) at z ≈ 2 using new wide-band 250-500 MHz receivers on board the Giant Metrewave Radio Telescope. The integrated H I 21 cm optical depths are 0.85 ± 0.16 km s{sup –1} (TXS1755+578) and 2.95 ± 0.15 km s{sup –1} (TXS1850+402). For the z = 1.9698 DLA toward TXS1755+578, the difference in H I 21 cm and C I profiles and the weakness of the radio core suggest that the H I 21cm absorption arises toward radio components in the jet, and that the optical and radio sightlines are not the same. This precludes an estimate of the DLA spin temperature. For the z = 1.9888 DLA toward TXS1850+402, the absorber covering factor is likely to be close to unity, as the background source is extremely compact, with the entire 5 GHz emission arising from a region of ≤ 1.4 mas in size. This yields a DLA spin temperature of T{sub s} = (372 ± 18) × (f/1.0) K, lower than typical T{sub s} values in high-z DLAs. This low spin temperature and the relatively high metallicity of the z = 1.9888 DLA ([Zn/H] =(– 0.68 ± 0.04)) are consistent with the anti-correlation between metallicity and spin temperature that has been found earlier in damped Lyα systems.

  15. Modeling Ice Table Depth, Ground Ice Content, and δD-δ18O of Ground Ice in the Cold Dry Soils of Earth and Mars

    NASA Astrophysics Data System (ADS)

    Fisher, D. A.; Lacelle, D.; Pollard, W.; Davila, A.; McKay, C. P.

    2016-09-01

    In the upper McMurdo Dry Valleys, ice table depths range from 0 to 80 cm. This study explores the effects of ground temperature and humidity and advective flows on water vapour flux and ice table depth using the REGO vapour-diffusion model.

  16. Study on the Retrieval of Snow Depth from FY3B/MWRI in the Atctic

    NASA Astrophysics Data System (ADS)

    Li, Lele; Chen, Haihua; Guan, Lei

    2016-06-01

    temperatures. Given the high albedo and low thermal conductivity, snow is regarded as one of the key reasons for the amplification of the warming in polar regions. The distributions of sea ice and snow depth are essential to the whole thermal conduction in the Arctic. This study focused on the retrieval of snow depth on sea ice from brightness temperatures of the MicroWave Radiometer Imager (MWRI) onboard the FengYun (FY)-3B satellite during the period from December 1, 2010 to April 30, 2011. After cross calibrated to the Advanced Microwave Scanning Radiometer-EOS (AMSR-E) Level 2A data, the MWRI brightness temperatures were applied to calculate the sea ice concentrations based on the Arctic Radiation and Turbulence Interaction Study Sea Ice (ASI) algorithm. According to the proportional relationship between the snow depth and the surface scattering in 18.7 and 36.5 GHz, the snow depths were derived. In order to eliminate the influence of uncertainties in grain sizes of snow as well as sporadic weather effects, the seven-day averaged snow depths were calculated. Then the results were compared with the snow depths from the AMSR-E Level 3 Sea Ice products. The bias of differences between the MWRI and the AMSR-E Level 3 products are ranged between -1.09 and -0.32 cm while the standard deviations and the correlation coefficients are ranged from 2.47 to 2.88 cm and from 0.78 to 0.90 for different months. As a result, it could be summarized that FY3B/MWRI showed a promising prospect in retrieving snow depth on sea ice.

  17. Campbell penetration depth in Fe-based superconductors

    SciTech Connect

    Prommapan, Plegchart

    2011-01-01

    A 'true' critical current density, jc, as opposite to commonly measured relaxed persistent (Bean) current, jB, was extracted from the Campbell penetration depth, Λc(T,H) measured in single crystals of LiFeAs, and optimally electron-doped Ba(Fe0.954Ni0.046)2As2 (FeNi122). In LiFeAs, the effective pinning potential is nonparabolic, which follows from the magnetic field - dependent Labusch parameter α. At the equilibrium (upon field - cooling), α(H) is non-monotonic, but it is monotonic at a finite gradient of the vortex density. This behavior leads to a faster magnetic relaxation at the lower fields and provides a natural dynamic explanation for the fishtail (second peak) effect. We also find the evidence for strong pinning at the lower fields.The inferred field dependence of the pinning potential is consistent with the evolution from strong pinning, through collective pinning, and eventually to a disordered vortex lattice. The value of jc(2 K) ≅ 1.22 x 106 A/cm2 provide an upper estimate of the current carrying capability of LiFeAs. Overall, vortex behavior of almost isotropic, fully-gapped LiFeAs is very similar to highly anisotropic d-wave cuprate superconductors, the similarity that requires further studies in order to understand unconventional superconductivity in cuprates and pnictides. In addition to LiFeAs, we also report the magnetic penetration depth in BaFe2As2 based superconductors including irradiation of FeNi122. In unirradiated FeNi122, the maximum critical current value is, jc(2K) ≅ 3.3 x 106 A/cm2. The magnetic-dependent feature was observed near the transition temperature in FeTe0.53Se0.47 and irradiated FeNi122. Because of this feature, further studies are required in order to properly calibrate the Campbell penetration depth. Finally, we detected the crossing between

  18. Expansive Soil Crack Depth under Cumulative Damage

    PubMed Central

    Shi, Bei-xiao; Chen, Sheng-shui; Han, Hua-qiang; Zheng, Cheng-feng

    2014-01-01

    The crack developing depth is a key problem to slope stability of the expansive soil and its project governance and the crack appears under the roles of dry-wet cycle and gradually develops. It is believed from the analysis that, because of its own cohesion, the expansive soil will have a certain amount of deformation under pulling stress but without cracks. The soil body will crack only when the deformation exceeds the ultimate tensile strain that causes cracks. And it is also believed that, due to the combined effect of various environmental factors, particularly changes of the internal water content, the inherent basic physical properties of expansive soil are weakened, and irreversible cumulative damages are eventually formed, resulting in the development of expansive soil cracks in depth. Starting from the perspective of volumetric strain that is caused by water loss, considering the influences of water loss rate and dry-wet cycle on crack developing depth, the crack developing depth calculation model which considers the water loss rate and the cumulative damages is established. Both the proposal of water loss rate and the application of cumulative damage theory to the expansive soil crack development problems try to avoid difficulties in matrix suction measurement, which will surely play a good role in promoting and improving the research of unsaturated expansive soil. PMID:24737974

  19. Adult antarctic krill feeding at abyssal depths.

    PubMed

    Clarke, Andrew; Tyler, Paul A

    2008-02-26

    Antarctic krill (Euphausia superba) is a large euphausiid, widely distributed within the Southern Ocean [1], and a key species in the Antarctic food web [2]. The Discovery Investigations in the early 20(th) century, coupled with subsequent work with both nets and echosounders, indicated that the bulk of the population of postlarval krill is typically confined to the top 150 m of the water column [1, 3, 4]. Here, we report for the first time the existence of significant numbers of Antarctic krill feeding actively at abyssal depths in the Southern Ocean. Biological observations from the deep-water remotely operated vehicle Isis in the austral summer of 2006/07 have revealed the presence of adult krill (Euphausia superba Dana), including gravid females, at unprecedented depths in Marguerite Bay, western Antarctic Peninsula. Adult krill were found close to the seabed at all depths but were absent from fjords close inshore. At all locations where krill were detected they were seen to be actively feeding, and at many locations there were exuviae (cast molts). These observations revise significantly our understanding of the depth distribution and ecology of Antarctic krill, a central organism in the Southern Ocean ecosystem.

  20. How Item Writers Understand Depth of Knowledge

    ERIC Educational Resources Information Center

    Wyse, Adam E.; Viger, Steven G.

    2011-01-01

    An important part of test development is ensuring alignment between test forms and content standards. One common way of measuring alignment is the Webb (1997, 2007) alignment procedure. This article investigates (a) how well item writers understand components of the definition of Depth of Knowledge (DOK) from the Webb alignment procedure and (b)…

  1. Microwave interferometer controls cutting depth of plastics

    NASA Technical Reports Server (NTRS)

    Heisman, R. M.; Iceland, W. F.

    1969-01-01

    Microwave interferometer system controls the cutting of plastic materials to a prescribed depth. The interferometer is mounted on a carriage with a spindle and cutting tool. A cross slide, mounted on the carriage, allows the interferometer and cutter to move toward or away from the plastic workpiece.

  2. Modified algesimeter provides accurate depth measurements

    NASA Technical Reports Server (NTRS)

    Turner, D. P.

    1966-01-01

    Algesimeter which incorporates a standard sensory needle with a sensitive micrometer, measures needle point depth penetration in pain tolerance research. This algesimeter provides an inexpensive, precise instrument with assured validity of recordings in those biomedical areas with a requirement for repeated pain detection or ascertaining pain sensitivity.

  3. "Learning in Depth" in Teaching Education

    ERIC Educational Resources Information Center

    Egan, Kieran

    2015-01-01

    The "Learning in Depth" program is a simple but radical innovation, which was first implemented in Canada in 2008/2009 and is now being used in a dozen countries with many thousand students. The aim of the program is to ensure that every student becomes an expert on something during schooling. The unusualness of the program and the fact…

  4. 21 CFR 882.1330 - Depth electrode.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Depth electrode. 882.1330 Section 882.1330 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL... signals at, subsurface levels of the brain. (b) Classification. Class II (performance standards)....

  5. 21 CFR 882.1330 - Depth electrode.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Depth electrode. 882.1330 Section 882.1330 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL... signals at, subsurface levels of the brain. (b) Classification. Class II (performance standards)....

  6. 21 CFR 882.1330 - Depth electrode.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Depth electrode. 882.1330 Section 882.1330 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL... signals at, subsurface levels of the brain. (b) Classification. Class II (performance standards)....

  7. Sensitivity to Binocular Depth Information in Infants

    ERIC Educational Resources Information Center

    Gordon, F. Robert; Yonas, Albert

    1976-01-01

    In order to study infants' sensitivity to binocular information for depth, 11 infants, 20 to 26 weeks of age, were presented with real and stereoscopically projected virtual objects at three distances, and the infants' reaching behavior was videotaped. (Author/SB)

  8. Depth-sounding lidar: performance and models

    NASA Astrophysics Data System (ADS)

    Steinvall, Ove K.; Koppari, Kurt R.; Lejdebrink, Ulf; Winell, Johan; Nilsson, Magnus; Ellsen, Rutger; Gjellan, Einar

    1996-06-01

    This paper describes the depth surrounding activities in Sweden. These include the development of a helicopter borne lidar called FLASH as well as instrumentation for in situ measurement of the optical water parameters. The FLASH system has been further developed into two operational systems called Hawk Eye with Saab Dynamics as the main contractor and Optech Inc. as the main subcontractor. Data collection and evaluation from Hawk Eye will be discussed. The Swedish Defence Research Establishment (FOA) is member of the Hawk Eye project team together with the National Maritime Administration, the Royal Swedish Navy and the Defence Material Administration. Together with the Swedish Maritime Administration, FOA has been engaged in analysis of lidar data to determine system performance and possible ways to optimize that in relation to lidar parameters and anticipated bottom depth and topography. Examples from that analysis will be presented. The test analysis so far strongly supports the depth sounding lidar technology as being a rapid and accurate sounder fulfilling the requirement by International Hydrographic Office on depth accuracy.

  9. Expansive soil crack depth under cumulative damage.

    PubMed

    Shi, Bei-xiao; Chen, Sheng-shui; Han, Hua-qiang; Zheng, Cheng-feng

    2014-01-01

    The crack developing depth is a key problem to slope stability of the expansive soil and its project governance and the crack appears under the roles of dry-wet cycle and gradually develops. It is believed from the analysis that, because of its own cohesion, the expansive soil will have a certain amount of deformation under pulling stress but without cracks. The soil body will crack only when the deformation exceeds the ultimate tensile strain that causes cracks. And it is also believed that, due to the combined effect of various environmental factors, particularly changes of the internal water content, the inherent basic physical properties of expansive soil are weakened, and irreversible cumulative damages are eventually formed, resulting in the development of expansive soil cracks in depth. Starting from the perspective of volumetric strain that is caused by water loss, considering the influences of water loss rate and dry-wet cycle on crack developing depth, the crack developing depth calculation model which considers the water loss rate and the cumulative damages is established. Both the proposal of water loss rate and the application of cumulative damage theory to the expansive soil crack development problems try to avoid difficulties in matrix suction measurement, which will surely play a good role in promoting and improving the research of unsaturated expansive soil. PMID:24737974

  10. Lunar Regolith Depths from LROC Images

    NASA Astrophysics Data System (ADS)

    Bart, Gwendolyn D.; Nickerson, R.; Lawder, M.

    2010-10-01

    Since the 1960's, most lunar photography and science covered the equatorial near side where the Apollo spacecraft landed. As a result, our understanding of lunar regolith depth was also limited to that region. Oberbeck and Quaide (JGR 1968) found regolith depths for the lunar near side: 3 m (Oceanus Procellarum), 16 m (Hipparchus), and 1-10 m at the Surveyor landing sites. The Lunar Reconnaissance Orbiter Camera recently released high resolution images that sample regions all around the lunar globe. We examined a selection of these images across the lunar globe and determined a regolith depth for each area. To do this, we measured the ratio of the diameter of the flat floor to the diameter of the crater, and used it to calculate the regolith thickness using the method of Quaide and Oberbeck (JGR 1968). Analysis of the global distribution of lunar regolith depths will provide new insights into the evolution of the lunar surface and the frequency, distribution, and effect of impacts.

  11. 21 CFR 882.1330 - Depth electrode.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Depth electrode. 882.1330 Section 882.1330 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL... signals at, subsurface levels of the brain. (b) Classification. Class II (performance standards)....

  12. 21 CFR 882.1330 - Depth electrode.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Depth electrode. 882.1330 Section 882.1330 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL... signals at, subsurface levels of the brain. (b) Classification. Class II (performance standards)....

  13. Doping effect on the structural properties of Cu1-x(Ni, Zn, Al and Fe)xO samples (00.10): An experimental and computational study

    NASA Astrophysics Data System (ADS)

    Amaral, J. B.; Araujo, R. M.; Pedra, P. P.; Meneses, C. T.; Duque, J. G. S.; dos S. Rezende, M. V.

    2016-09-01

    In this work, the effect of insertion of transition metal, TM (=Ni, Zn, Al and Fe), ions in Cu1-xTMxO samples (00.10) prepared via co-precipitation method is studied through experimental and computational methods. The analyses of X-ray diffraction (XRD) patterns using Rietveld refinement show that i) at x=0, all samples present a monoclinic crystal system with space group C2/c and ii) for increasing the TM-doping, Ni and Zn-doped samples show a small amount of spurious phases for concentrations above x=0.05. Based on these results, a defect disorder study for using atomistic computational simulations which is based on the lattice energy minimization technique is employed to predict the location of the dopant ions in the structure. In agreement with XRD data, our computational results indicate that the trivalent (Al and Fe ions) are more favorable to be incorporated into CuO matrix than the divalent (Ni and Zn ions).

  14. Magnetic and structural characteristics of multiferroic Fe3O4/(Bi3.25Nd0.65Eu0.10)Ti3O12 composite thin films deposited by metalorganic chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Kobune, Masafumi; Furotani, Ryosuke; Fujita, Satoshi; Kikuchi, Kazuki; Kikuchi, Takeyuki; Fujisawa, Hironori; Shimizu, Masaru; Fukumuro, Naoki

    2016-10-01

    Ferromagnetic magnetite (Fe3O4) thin films for magnetoelectric multiferroic applications were deposited on (200) (Bi3.25Nd0.65Eu0.10)Ti3O12 (BNEuT)/(101) Nb:TiO2 substrates by metalorganic chemical vapor deposition (MOCVD) using an iron(III) tris(2,2,6,6-tetramethyl-3,5-heptanedionato) precursor as the iron source. The BNEuT film utilized as a ferroelectric template material was in the form of freestanding nanoplates with narrow spaces between them. The effects of deposition conditions such as the deposition time and substrate temperature on the magnetic and structural characteristics of the Fe3O4/BNEuT composite films were investigated. All the films consisted of mostly single-phase Fe3O4 with a cubic inverse-spinel structure. When deposition was carried out at temperatures of 400-420 °C, the filling rates of particles introduced into the narrow spaces between the BNEuT nanoplates exhibited high values of 76-89% including the amorphous phase. This suggested that the deposition in this temperature range made progress according to the growth mechanism of MOCVD in the surface reaction rate determining state. Room-temperature magnetic moment-magnetic field curves for Fe3O4 thin films deposited at 400-500 °C for 60 min exhibited narrow rectangular hysteresis loops, indicating typical soft magnetic characteristics.

  15. Synthesis and crystal structure of 4-(2-ammonio­eth­yl)morpholin-4-ium di­chlorido­diiodido­cadmate/chlorido­tri­iodido­cadmate (0.90/0.10)

    PubMed Central

    Mahbouli Rhouma, Najla; Rayes, Ali; Mezzadri, Francesco; Calestani, Gianluca; Loukil, Mohamed

    2016-01-01

    The crystal structure of the title compound, (C6H16N2O)[CdCl1.90I2.10], a new organic–inorganic hybrid salt synthesized in the form of single crystals, consists of discrete statistically distributed di­chlorido­diiodido­cadmate/chlorido­tri­iodido­cadmate anions (occupancy ratio 0.90:0.10) and 4-(2-ammonio­eth­yl)morpholin-4-ium cations, [NH3(CH2)2NH(CH2)4O]2+. The cations are linked by inter­molecular N—H⋯O hydrogen bonds, forming corrugated chains extending parallel to the c axis. The [CdCl1.90I2.10]2− tetra­halidocadmate anions lie between the chains to maximize the electrostatic inter­actions and are connected with the organic cations via N—H⋯Cl and C—H⋯Cl(I) hydrogen bonds developing in the ab plane and leading to the formation of a three-dimensional network structure. The tetra­coordinate CdII atom has a distorted tetra­hedral conformation, with a τ4 index of 0.87. PMID:27746929

  16. In-situ Electric Field-Induced Modulation of Photoluminescence in Pr-doped Ba0.85Ca0.15Ti0.90Zr0.10O3 Lead-Free Ceramics

    NASA Astrophysics Data System (ADS)

    Sun, Hai Ling; Wu, Xiao; Chung, Tat Hang; Kwok, K. W.

    2016-06-01

    Luminescent materials with dynamic photoluminescence activity have aroused special interest because of their potential widespread applications. One proposed approach of directly and reversibly modulating the photoluminescence emissions is by means of introducing an external electric field in an in-situ and real-time way, which has only been focused on thin films. In this work, we demonstrate that real-time electric field-induced photoluminescence modulation can be realized in a bulk Ba0.85Ca0.15Ti0.90Zr0.10O3 ferroelectric ceramic doped with 0.2 mol% Pr3+, owing to its remarkable polarization reversal and phase evolution near the morphotropic phase boundary. Along with in-situ X-ray diffraction analysis, our results reveal that an applied electric field induces not only typical polarization switching and minor crystal deformation, but also tetragonal-to-rhombohedral phase transformation of the ceramic. The electric field-induced phase transformation is irreversible and engenders dominant effect on photoluminescence emissions as a result of an increase in structural symmetry. After it is completed in a few cycles of electric field, the photoluminescence emissions become governed mainly by the polarization switching, and thus vary reversibly with the modulating electric field. Our results open a promising avenue towards the realization of bulk ceramic-based tunable photoluminescence activity with high repeatability, flexible controllability, and environmental-friendly chemical process.

  17. In-situ Electric Field-Induced Modulation of Photoluminescence in Pr-doped Ba0.85Ca0.15Ti0.90Zr0.10O3 Lead-Free Ceramics

    PubMed Central

    Sun, Hai Ling; Wu, Xiao; Chung, Tat Hang; Kwok, K. W.

    2016-01-01

    Luminescent materials with dynamic photoluminescence activity have aroused special interest because of their potential widespread applications. One proposed approach of directly and reversibly modulating the photoluminescence emissions is by means of introducing an external electric field in an in-situ and real-time way, which has only been focused on thin films. In this work, we demonstrate that real-time electric field-induced photoluminescence modulation can be realized in a bulk Ba0.85Ca0.15Ti0.90Zr0.10O3 ferroelectric ceramic doped with 0.2 mol% Pr3+, owing to its remarkable polarization reversal and phase evolution near the morphotropic phase boundary. Along with in-situ X-ray diffraction analysis, our results reveal that an applied electric field induces not only typical polarization switching and minor crystal deformation, but also tetragonal-to-rhombohedral phase transformation of the ceramic. The electric field-induced phase transformation is irreversible and engenders dominant effect on photoluminescence emissions as a result of an increase in structural symmetry. After it is completed in a few cycles of electric field, the photoluminescence emissions become governed mainly by the polarization switching, and thus vary reversibly with the modulating electric field. Our results open a promising avenue towards the realization of bulk ceramic-based tunable photoluminescence activity with high repeatability, flexible controllability, and environmental-friendly chemical process. PMID:27339815

  18. Deuteron NMR study of dynamics and of coexistence of paraelectric and ferroelectric phases in Rb0.90(ND4)0.10D2AsO4

    NASA Astrophysics Data System (ADS)

    Pinto, Nicholas J.; Howell, Francis L.; Schmidt, V. Hugo

    1993-09-01

    The deuteron glass Rb1-x(ND4)xD2AsO4 (DRADA) is a mixed crystal of RbD2AsO4 (DRDA) and ND4D2AsO4 (DADA). Deuteron nuclear magnetic resonance has been performed on the acid and ammonium deuterons. The crystal studied has an ammonium concentration (x=0.10) that puts it in the coexistence region of the phase diagram. Line-shape measurements of the ammonium deuterons show the coexistence of the ferroelectric (FE) and paraelectric (PE) phases as the temperature is lowered below the ferroelectric-phase-transition temperature Tc. The acid deuteron line shape on the other hand is found to broaden as the temperature is reduced but is unaffected by the ferroelectric transition. Spin-lattice-relaxation measurements have been performed and the activation energies for the relaxation processes have been computed. The relaxation-rate anomaly for acid deuterons in the ferroelectric-transition range indicates a short correlation length for the FE phase in the coexistence region of the phase diagram.

  19. Knee joint kinetics in relation to commonly prescribed squat loads and depths.

    PubMed

    Cotter, Joshua A; Chaudhari, Ajit M; Jamison, Steve T; Devor, Steven T

    2013-07-01

    Controversy exists regarding the safety and performance benefits of performing the squat exercise to depths beyond 90° of knee flexion. Our aim was to compare the net peak external knee flexion moments (pEKFM) experienced over typical ranges of squat loads and depths. Sixteen recreationally trained men (n = 16; age, 22.7 ± 1.1 years; body mass, 85.4 ± 2.1 kg; height, 177.6 ± 0.96 cm; mean ± SEM) with no previous lower-limb surgeries or other orthopedic issues and at least 1 year of consistent resistance training experience while using the squat exercise performed single-repetition squat trials in a random order at squat depths of above parallel, parallel, and below parallel. Less than 1 week before testing, 1RM values were found for each squat depth. Subsequent testing required the subjects to perform squats at the 3 depths with 3 different loads: unloaded, 50% 1RM, and 85% 1RM (9 total trials). Force platform and kinematic data were collected to calculate pEKFM. To assess the differences among loads and depths, a 2-factor (load and depth) repeated measures analysis of variance with significance set at the p < 0.05 level was used. Squat 1RM significantly decreased 13.6% from the above-parallel to the parallel squat and another 3.6% from the parallel to the below-parallel squat (p < 0.05). Net peak external knee flexion moments significantly increased as both squat depth and load were increased (p ≤ 0.02). Slopes of pEKFM were greater from unloaded to 50% 1RM than when progressing from 50% to 85% 1RM (p < 0.001). The results suggest that typical decreases in squat loads used with increasing depths are not enough to offset increases in pEKFM.

  20. Collisional energy deposition threshold for extended damage depths in ion-implanted silicates

    SciTech Connect

    Arnold, G.W.; Battaglin, G.; Boscolo-Boscoletto, A.; Caccavalle, F.; De Marchi, G.; Mazzoldi, P.; Miotello, A.

    1991-12-31

    Many properties of implanted fused silica (e.g., surface stress, hardness) exhibit maximum implantation-induced changes for collisional energy deposition values of {approximately}10{sup 20} keV/cm{sup 3}. We have observed a second critical energy deposition threshold value of about 10{sup 22} keV/cm{sup 3} in stress and hardness measurements as well as in many other experiments on silicate glasses (leaching, alkali depletion, etching rate, gaseous implant redistribution). The latter show evidence for damage depths exceeding TRIM ranges by about a factor of 2. For crystalline quartz, a similar threshold value has been found for extended damage depths (greater than TRIM) for 250 kev ions (H-Au) as measured by RBS and interference fringes. This phenomenon at high damage deposition energy may involve the large stress gradients between damaged and undamaged regions and the much increased diffusion coefficient for defect transport. 13 refs., 6 figs.

  1. Collisional energy deposition threshold for extended damage depths in ion-implanted silicates

    SciTech Connect

    Arnold, G.W. ); Battaglin, G. ); Boscolo-Boscoletto, A. ); Caccavalle, F.; De Marchi, G.; Mazzoldi, P. ); Miotello, A. (Consorzio INFM, Dipartiment

    1991-01-01

    Many properties of implanted fused silica (e.g., surface stress, hardness) exhibit maximum implantation-induced changes for collisional energy deposition values of {approximately}10{sup 20} keV/cm{sup 3}. We have observed a second critical energy deposition threshold value of about 10{sup 22} keV/cm{sup 3} in stress and hardness measurements as well as in many other experiments on silicate glasses (leaching, alkali depletion, etching rate, gaseous implant redistribution). The latter show evidence for damage depths exceeding TRIM ranges by about a factor of 2. For crystalline quartz, a similar threshold value has been found for extended damage depths (greater than TRIM) for 250 kev ions (H-Au) as measured by RBS and interference fringes. This phenomenon at high damage deposition energy may involve the large stress gradients between damaged and undamaged regions and the much increased diffusion coefficient for defect transport. 13 refs., 6 figs.

  2. Measurements of the half-life of 246Cm and the alpha-decay emission probabilities of 246Cm and 250Cf.

    PubMed

    Kondev, F G; Ahmad, I; Greene, J P; Kellett, M A; Nichols, A L

    2007-03-01

    The alpha-decay half-life of Cm246 has been measured to be T(1/2)=4706 (40)yr by means of the alpha-counting of ingrowth activity following the decay of a mass separated source of the Cf250 parent nuclide. The alpha-decay emission probabilities of Cm246 and Cf250 have also been determined with high precision and have been compared with results from previous measurements. A new alpha-decay branch of Cm246 to the 4(+) level of the ground-state band of the Pu242 daughter nucleus has been identified and characterized.

  3. Localization of soil depth for N uptake by Kobresia roots in Tibetan grassland

    NASA Astrophysics Data System (ADS)

    Marten Schleuß, Per-; Steingräber, Laura; Guggenberger, Georg; Kuzyakov, Yakov

    2013-04-01

    The Tibetan Plateau provides the world's largest alpine ecosystem and is dominated by Kobresia grasslands, which cover ca. 450,000 km2. Kobresia pastures are expected to be grazing-induced and are accompanied by sedge-turf varying in thickness between 5 - 30 cm. These pastoral root mat ecosystems are of global and regional importance due to its impact on global water, heat and carbon cycles, its high storage of carbon, nitrogen and other nutrients and its provision of important grazing areas, because they protect against mechanical degradation and provide a fast regrowth after heavy grazing events. Yet, less is known about the development and functioning of this Kobresia root mats. We investigated the nitrogen uptake from different soil depths mainly consisting on Kobresia root mats and N mobilisation into the soil-plant-system by localized 15N additions. A 15N pulse labeling experiment was set up in July 2012 during the vegetation period on sites of the KEMA research station (Kobresia Ecosystem Monitoring Area) near the city Nagqu. 15N urea was injected into six soil depths: 0-1 cm, 1-5 cm, 5-10 cm, 10-15 cm, 15-20 cm, 20-25 cm. Samples of soil, root and shoots were taken 45 days after the 15N labeling. Detailed description of soil profiles were carried out considering basic characteristics of single horizons. Due to low atmospheric N depositions and high N immobilization in the root mats, the study site is limited by plant available N. Hence, N uptake efficiency is assumed to be generally high and thus highest 15N amounts should be recovered in above- and belowground plant biomass. Moreover, by linking information of localization of N uptake and the morphological description of Kobresia-turf profiles, the functional purpose of single horizons can be obtained, which help to understand its successful establishment, functions and future trends with regard to change of climate and management.

  4. Depth-dependent abundance and distribution of microorganisms in forest soil

    NASA Astrophysics Data System (ADS)

    Preusser, Sebastian; Niebuhr, Jana; Angst, Gerrit; Heinze, Stefanie; Müller, Carsten W.; Kögel-Knabner, Ingrid; Marschner, Bernd; Kandeler, Ellen

    2014-05-01

    Soil microorganisms involved in carbon cycling face different habitat conditions in topsoil and subsoil environments. While the habitat conditions and mechanisms influencing the abundance of soil microorganisms and development of soil microbial communities in topsoil are well investigated, these dynamics have been largely unexplored in deeper soil horizons. Limited information is available on the effects of different environmental factors such as water content, pH and available organic carbon (OC) on soil microorganisms in subsoil. More research is needed about both the abundance and composition of microbial communities and, by extension, the microbial decomposition of soil organic matter in deeper soil horizons. We investigated both the abundance of microorganisms and the composition of the microbial communities in soil samples of a podzolic Cambisol from a European beech (Fagus sylvatica L.) forest stand in Lower Saxony, Germany. The samples were taken along three transects in a grid sampling pattern. Each transect consisted of 64 sampling points, eight vertical, from a depth of 10 cm to a depth of 185 cm, by eight horizontal, starting at the root zone of an individual beech tree, from zero to 315 cm. Environmental measurements included pH, soil water content, OC and root-associated carbon. Microbial biomass was determined using the chloroform fumigation extraction (CFE) method. Abundances of bacteria, fungi, archaea and seven of the most important taxa specific groups of bacteria in the soil samples were evaluated with quantitative PCR. In agreement with previous studies, soil microorganisms were most abundant in topsoil and decreased with depth. The composition of the total microbial community shifted significantly with increasing depth. While bacteria were detectable in all horizons, fungi exhibited patchy distribution below 60 cm and archaea were not detectable in samples below a sampling depth of 60 - 80 cm. Within the bacterial community, both taxa

  5. When depth is no refuge: cumulative thermal stress increases with depth in Bocas del Toro, Panama

    NASA Astrophysics Data System (ADS)

    Neal, B. P.; Condit, C.; Liu, G.; dos Santos, S.; Kahru, M.; Mitchell, B. G.; Kline, D. I.

    2014-03-01

    Coral reefs are increasingly affected by high-temperature stress events and associated bleaching. Monitoring and predicting these events have largely utilized sea surface temperature data, due to the convenience of using large-scale remotely sensed satellite measurements. However, coral bleaching has been observed to vary in severity throughout the water column, and variations in coral thermal stress across depths have not yet been well investigated. In this study, in situ water temperature data from 1999 to 2011 from three depths were used to calculate thermal stress on a coral reef in Bahia Almirante, Bocas del Toro, Panama, which was compared to satellite surface temperature data and thermal stress calculations for the same area and time period from the National Oceanic and Atmospheric Administration Coral Reef Watch Satellite Bleaching Alert system. The results show similar total cumulative annual thermal stress for both the surface and depth-stratified data, but with a striking difference in the distribution of that stress among the depth strata during different high-temperature events, with the greatest thermal stress unusually recorded at the deepest measured depth during the most severe bleaching event in 2005. Temperature records indicate that a strong density-driven temperature inversion may have formed in this location in that year, contributing to the persistence and intensity of bleaching disturbance at depth. These results indicate that depth may not provide a stress refuge from high water temperature events in some situations, and in this case, the water properties at depth appear to have contributed to greater coral bleaching at depth compared to near-surface locations. This case study demonstrates the importance of incorporating depth-stratified temperature monitoring and small-scale oceanographic and hydrologic data for understanding and predicting local reef responses to elevated water temperature events.

  6. C-M diagram and luminosity function of the Galactic globular cluster NGC 7099. I. Photographic photometry

    SciTech Connect

    Piotto, G.; Rosino, L.; Capaccioli, M.; Ortolani, S.; Alcaino, G.

    1987-08-01

    New photographic photometry of about 4400 stars in the field of the Galactic globular cluster NGC 7099 = M30 is presented. A C-M diagram and a luminosity function are obtained from this photometry. The distance modulus is estimated at 14.5 + or - 0.5 assuming V(HB) = 15.11 + or - 0.10 and E(B-V) = 0.03 + or - 0.03. The metallicity is (Fe/H) = 1.9 + or - 0.3 based on the dereddened color index (B-V)0,g = 0.71 + or - 0.03. The theoretical isochrones of VandenBerg and Bell (1985) give a better fit to the observations assuming (Fe/H) = -1.8, (m-M)V = 14.6, and E(B-V) = 0.02. A fair fit is also obtained using isochrones of low iron content with an oxygen enhancement of 0.7. From the fit, an age of 17 + or - 4 Gyr is deduced. 41 references.

  7. Depth distribution of cesium-137 in paddy fields across the Fukushima pollution plume in 2013.

    PubMed

    Lepage, Hugo; Evrard, Olivier; Onda, Yuichi; Lefèvre, Irène; Laceby, J Patrick; Ayrault, Sophie

    2015-09-01

    Large quantities of radiocesium were deposited across a 3000 km(2) area northwest of the Fukushima Dai-ichi nuclear power plant after the March 2011 accident. Although many studies have investigated the fate of (137)Cs in soil in the months following the accident, the depth distribution of this radioactive contaminant in rice paddy fields requires further examination after the typhoons that occurred in this region. Such investigations will help minimize potential human exposure in rice paddy fields. Radionuclide activity concentrations, organic content and particle size were analysed in 10 soil cores sampled from paddy fields in November 2013, 20 km north of the Fukushima power plant. Our results demonstrate limited depth migration of (137)Cs with the majority concentrated in the uppermost layers of soils (<5 cm). More than 30 months after the accident, between 46.8 and 98.7% of the total (137)Cs inventories was found within the top 5 cm of the soil surface, despite cumulative rainfall totalling 3300 mm. Furthermore, there were no significant correlations between (137)Cs depth distribution and the other parameters. We attributed the maximum depth penetration of (137)Cs to grass cutting (73.6-98.5% of (137)Cs in the upper 5 cm) and farming operations (tillage - 46.8-51.6% of (137)Cs in the upper 5 cm). As this area is exposed to erosive events, ongoing decontamination works may increase soil erodibility. We therefore recommend the rapid removal of the uppermost - contaminated - layer of the soil after removing the vegetation to avoid erosion of contaminated material during the subsequent rainfall events. Further analysis is required to thoroughly understand the impacts of erosion on the redistribution of radiocesium throughout the Fukushima Prefecture.

  8. Depth distribution of cesium-137 in paddy fields across the Fukushima pollution plume in 2013.

    PubMed

    Lepage, Hugo; Evrard, Olivier; Onda, Yuichi; Lefèvre, Irène; Laceby, J Patrick; Ayrault, Sophie

    2015-09-01

    Large quantities of radiocesium were deposited across a 3000 km(2) area northwest of the Fukushima Dai-ichi nuclear power plant after the March 2011 accident. Although many studies have investigated the fate of (137)Cs in soil in the months following the accident, the depth distribution of this radioactive contaminant in rice paddy fields requires further examination after the typhoons that occurred in this region. Such investigations will help minimize potential human exposure in rice paddy fields. Radionuclide activity concentrations, organic content and particle size were analysed in 10 soil cores sampled from paddy fields in November 2013, 20 km north of the Fukushima power plant. Our results demonstrate limited depth migration of (137)Cs with the majority concentrated in the uppermost layers of soils (<5 cm). More than 30 months after the accident, between 46.8 and 98.7% of the total (137)Cs inventories was found within the top 5 cm of the soil surface, despite cumulative rainfall totalling 3300 mm. Furthermore, there were no significant correlations between (137)Cs depth distribution and the other parameters. We attributed the maximum depth penetration of (137)Cs to grass cutting (73.6-98.5% of (137)Cs in the upper 5 cm) and farming operations (tillage - 46.8-51.6% of (137)Cs in the upper 5 cm). As this area is exposed to erosive events, ongoing decontamination works may increase soil erodibility. We therefore recommend the rapid removal of the uppermost - contaminated - layer of the soil after removing the vegetation to avoid erosion of contaminated material during the subsequent rainfall events. Further analysis is required to thoroughly understand the impacts of erosion on the redistribution of radiocesium throughout the Fukushima Prefecture. PMID:26026933

  9. Focal Depth of the WenChuan Earthquake Aftershocks from modeling of Seismic Depth Phases

    NASA Astrophysics Data System (ADS)

    Luo, Y.; Zeng, X.; Chong, J.; Ni, S.; Chen, Y.

    2008-12-01

    After the 05/12/2008 great WenChuan earthquake in Sichuan Province of China, tens of thousands earthquakes occurred with hundreds of them stronger than M4. Those aftershocks provide valuable information about seismotectonics and rupture processes for the mainshock, particularly accurate spatial distribution of aftershocks is very informational for determining rupture fault planes. However focal depth can not be well resolved just with first arrivals recorded by relatively sparse network in Sichuan Province, therefore 3D seismicity distribution is difficult to obtain though horizontal location can be located with accuracy of 5km. Instead local/regional depth phases such as sPmP, sPn, sPL and teleseismic pP,sP are very sensitive to depth, and be readily modeled to determine depth with accuracy of 2km. With reference 1D velocity structure resolved from receiver functions and seismic refraction studies, local/regional depth phases such as sPmP, sPn and sPL are identified by comparing observed waveform with synthetic seismograms by generalized ray theory and reflectivity methods. For teleseismic depth phases well observed for M5.5 and stronger events, we developed an algorithm in inverting both depth and focal mechanism from P and SH waveforms. Also we employed the Cut and Paste (CAP) method developed by Zhao and Helmberger in modeling mechanism and depth with local waveforms, which constrains depth by fitting Pnl waveforms and the relative weight between surface wave and Pnl. After modeling all the depth phases for hundreds of events , we find that most of the M4 earthquakes occur between 2-18km depth, with aftershocks depth ranging 4-12km in the southern half of Longmenshan fault while aftershocks in the northern half featuring large depth range up to 18km. Therefore seismogenic zone in the northern segment is deeper as compared to the southern segment. All the aftershocks occur in upper crust, given that the Moho is deeper than 40km, or even 60km west of the

  10. Heavy actinide production from the interactions of sup 40 Ar with sup 248 Cm and a comparison with the sup 44 Ca- sup 248 Cm system

    SciTech Connect

    Leyba, J.D.; Henderson, R.A.; Hall, H.L.; Gannett, C.M.; Chadwick, R.B.; Czerwinski, K.R.; Kadkhodayan, B.A.; Kreek, S.A.; Haynes, G.R.; Gregorich, K.E.; Lee, D.M.; Nurmia, M.J.; Hoffman, D.C. Nuclear Science Division, Lawrence Berkeley Laboratory, University of California, Berkeley, Berkeley, California 94720)

    1990-05-01

    Excitation functions have been measured for isotopes of Bk, Cf, Es, and Fm produced from the interactions of 207- to 286-MeV {sup 40}Ar ions with {sup 248}Cm. The measured isotopic distributions were found to be essentially symmetric with full widths at half maximum between 2.0 and 3.5 mass units. These results are comparable to those obtained in previous studies using {sup 40,44,48}Ca with {sup 248}Cm. The maxima of the isotopic distributions from the {sup 40}Ar-{sup 248}Cm system show shifts, to both heavier and lighter mass numbers, of 0 to 2 mass units relative to the corresponding maxima of the isotopic distributions from the {sup 40,44,48}Ca-{sup 248}Cm systems.

  11. 8.5 percent efficient screen-printed CdS/CdTe solar cell produced on a 5-cm x 10-cm glass substrate

    NASA Astrophysics Data System (ADS)

    Matsumoto, H.; Nakano, A.; Komatsu, Y.; Uda, H.; Kuribayashi, K.; Ikegami, S.

    1983-02-01

    The preparation conditions of CdS sintered film for 5-cm x 10-cm screen-printed CsS/CdTe solar cells were investigated. Increasing the belt speed of the belt furnace increased the residual amount of Cl ions in the CdS sintered film and lowered the efficiency of the cell. The optimum belt speed was 2 cm/min, corresponding to a sintering time of 90 min. The thickness of the CdS film was changed by changing the screen thickness. Increasing the thickness of the CdS film lowered its surface resistivity and improved the fill factor of a cell. A solar cell of 8.5 percent intrinsic efficiency was obtained from CdS film printed by an 80 mesh screen and sintered at 690 C at a belt speed of 2 cm/min.

  12. The depth dependence of earthquake duration and implications for rupture mechanisms

    USGS Publications Warehouse

    Vidale, J.E.; Houston, H.

    1993-01-01

    THE duration of rupture is a fundamental characteristic of earthquakes, and is important for understanding the mechanics of faulting1,2. The complexity of the seismic source and the incoherence of the high-frequency seismic wavefield often inhibit the identification, location and timing of features in the later part of earthquake rupture. Here we sum many teleseismic records from regional seismic arrays, producing an unusually clear depiction of the earthquake source at short periods by suppressing background noise and coda generated near the receivers. The ending, as well as the beginning, of rupture is clearly identifiable for most earthquakes examined. Measurements of 130 large earthquakes show that near 100 km depth, rupture duration averages 11s when scaled to a moment of 1026 dyn cm; this decreases to 5.5 s at 650 km depth. Models of faulting suggest that duration should be inversely proportional to the shear-wave velocity and the cube root of stress drop. Thus, to explain the observed twofold decrease in duration with depth, stress drops would have to increase by a factor of four, as shear velocity increases with depth by only about 20%. However, observed stress drops show no strong trend with depth3,4, suggesting that the faulting process changes with depth.

  13. Extinction depth and evapotranspiration from ground water under selected land covers.

    PubMed

    Shah, Nirjhar; Nachabe, Mahmood; Ross, Mark

    2007-01-01

    In many landscapes, vegetation extracts water from both the unsaturated and the saturated zones. The partitioning of evapotranspiration (ET) into vadose zone evapotranspiration and ground water evapotranspiration (GWET) is complex because it depends on land cover and subsurface characteristics. Traditionally, the GWET fraction is assumed to decay with increasing depth to the water table (DTWT), attaining a value of 0 at what is termed the extinction depth. A simple assumption of linear decay with depth is often used but has never been rigorously examined using unsaturated-saturated flow simulations. Furthermore, it is not well understood how to relate extinction depths to characteristics of land cover and soil texture. In this work, variable saturation flow theory is used to simulate GWET for three land covers and a range of soil properties under drying soil conditions. For a water table within half a meter of the land surface, nearly all ET is extracted from ground water due to the close hydraulic connection between the unsaturated and the saturated zones. For deep-rooted vegetation, the decoupling of ground water and vadose zone was found to begin at water table depths between 30 and 100 cm, depending on the soil texture. The decline of ET with DTWT is better simulated by an exponential decay function than the commonly used linear decay. A comparison with field data is consistent with the findings of this study. Tables are provided to vary the extinction depth for heterogeneous landscapes with different vegetation cover and soil properties.

  14. Aerosol Optical Depth Determinations for BOREAS

    NASA Technical Reports Server (NTRS)

    Wrigley, R. C.; Livingston, J. M.; Russell, P. B.; Guzman, R. P.; Ried, D.; Lobitz, B.; Peterson, David L. (Technical Monitor)

    1994-01-01

    Automated tracking sun photometers were deployed by NASA/Ames Research Center aboard the NASA C-130 aircraft and at a ground site for all three Intensive Field Campaigns (IFCs) of the Boreal Ecosystem-Atmosphere Study (BOREAS) in central Saskatchewan, Canada during the summer of 1994. The sun photometer data were used to derive aerosol optical depths for the total atmospheric column above each instrument. The airborne tracking sun photometer obtained data in both the southern and northern study areas at the surface prior to takeoff, along low altitude runs near the ground tracking sun photometer, during ascents to 6-8 km msl, along remote sensing flightlines at altitude, during descents to the surface, and at the surface after landing. The ground sun photometer obtained data from the shore of Candle Lake in the southern area for all cloud-free times. During the first IFC in May-June ascents and descents of the airborne tracking sun photometer indicated the aerosol optical depths decreased steadily from the surface to 3.5 kni where they leveled out at approximately 0.05 (at 525 nm), well below levels caused by the eruption of Mt. Pinatubo. On a very clear day, May 31st, surface optical depths measured by either the airborne or ground sun photometers approached those levels (0.06-0.08 at 525 nm), but surface optical depths were often several times higher. On June 4th they increased from 0.12 in the morning to 0.20 in the afternoon with some evidence of brief episodes of pollen bursts. During the second IFC surface aerosol optical depths were variable in the extreme due to smoke from western forest fires. On July 20th the aerosol optical depth at 525 nm decreased from 0.5 in the morning to 0.2 in the afternoon; they decreased still further the next day to 0.05 and remained consistently low throughout the day to provide excellent conditions for several remote sensing missions flown that day. Smoke was heavy for the early morning of July 24th but cleared partially by 10

  15. Depth distribution of radiocesium in Fukushima paddy fields three years after the accident

    NASA Astrophysics Data System (ADS)

    Lepage, Hugo; Laceby, J. Patrick; Evrard, Olivier; Onda, Yuichi; Lefèvre, Irène; Ayrault, Sophie

    2015-04-01

    Rice paddy fields located in the vicinity of the Fukushima Dai-Ichi Nuclear Power Plant (FDNPP) were contaminated by radioactive fallout from the March 2011 accident. Although many studies have investigated the fate of radiocesium in soil in the months following the accident, the potential migration of radiocesium in rice paddy fields requires further examination after major typhoons occurred in this region in 2011 and 2013. Further investigations are also required because paddy fields are typically comprised of Andosols, a soil type in which radiocesium has been known to potentially migrate deeper in the depth profile. To investigate the depth migration of radiocesium we collected soil cores in 10 paddy fields located less than 20 km from the FDNPP in November 2013. The maximum depth penetration of 137Cs was attributed to field maintenance (e.g. grass cutting) (97% of 137Cs in the upper 5-cm) and farming operations (tillage/cultivation - 83% of 137Cs in the upper 5-cm). The low migration observed in undisturbed paddy fields could be attributed to the presence of phyllosilicates that were detected by X-ray diffraction in Andosols. As radiocesium is mainly located in the uppermost soil layers, we recommend the rapid removal of these upper layers (e.g. the top 5 cm) to reduce radiocesium export during erosive events such as the major typhoons known to impact the region. Further research is required to thoroughly understand the impacts of erosion on the transfer and migration of radiocesium throughout the Fukushima Prefecture.

  16. Assessment of Density Variations of Marine Sediments with Ocean and Sediment Depths

    PubMed Central

    Tenzer, R.; Gladkikh, V.

    2014-01-01

    We analyze the density distribution of marine sediments using density samples taken from 716 drill sites of the Deep Sea Drilling Project (DSDP). The samples taken within the upper stratigraphic layer exhibit a prevailing trend of the decreasing density with the increasing ocean depth (at a rate of −0.05 g/cm3 per 1 km). Our results confirm findings of published studies that the density nonlinearly increases with the increasing sediment depth due to compaction. We further establish a 3D density model of marine sediments and propose theoretical models of the ocean-sediment and sediment-bedrock density contrasts. The sediment density-depth equation approximates density samples with an average uncertainty of about 10% and better represents the density distribution especially at deeper sections of basin sediments than a uniform density model. The analysis of DSDP density data also reveals that the average density of marine sediments is 1.70 g/cm3 and the average density of the ocean bedrock is 2.9 g/cm3. PMID:24744686

  17. Higher resolution stimulus facilitates depth perception: MT+ plays a significant role in monocular depth perception.

    PubMed

    Tsushima, Yoshiaki; Komine, Kazuteru; Sawahata, Yasuhito; Hiruma, Nobuyuki

    2014-01-01

    Today, we human beings are facing with high-quality virtual world of a completely new nature. For example, we have a digital display consisting of a high enough resolution that we cannot distinguish from the real world. However, little is known how such high-quality representation contributes to the sense of realness, especially to depth perception. What is the neural mechanism of processing such fine but virtual representation? Here, we psychophysically and physiologically examined the relationship between stimulus resolution and depth perception, with using luminance-contrast (shading) as a monocular depth cue. As a result, we found that a higher resolution stimulus facilitates depth perception even when the stimulus resolution difference is undetectable. This finding is against the traditional cognitive hierarchy of visual information processing that visual input is processed continuously in a bottom-up cascade of cortical regions that analyze increasingly complex information such as depth information. In addition, functional magnetic resonance imaging (fMRI) results reveal that the human middle temporal (MT+) plays a significant role in monocular depth perception. These results might provide us with not only the new insight of our neural mechanism of depth perception but also the future progress of our neural system accompanied by state-of- the-art technologies. PMID:25327168

  18. Reliable Fusion of Stereo Matching and Depth Sensor for High Quality Dense Depth Maps

    PubMed Central

    Liu, Jing; Li, Chunpeng; Fan, Xuefeng; Wang, Zhaoqi

    2015-01-01

    Depth estimation is a classical problem in computer vision, which typically relies on either a depth sensor or stereo matching alone. The depth sensor provides real-time estimates in repetitive and textureless regions where stereo matching is not effective. However, stereo matching can obtain more accurate results in rich texture regions and object boundaries where the depth sensor often fails. We fuse stereo matching and the depth sensor using their complementary characteristics to improve the depth estimation. Here, texture information is incorporated as a constraint to restrict the pixel’s scope of potential disparities and to reduce noise in repetitive and textureless regions. Furthermore, a novel pseudo-two-layer model is used to represent the relationship between disparities in different pixels and segments. It is more robust to luminance variation by treating information obtained from a depth sensor as prior knowledge. Segmentation is viewed as a soft constraint to reduce ambiguities caused by under- or over-segmentation. Compared to the average error rate 3.27% of the previous state-of-the-art methods, our method provides an average error rate of 2.61% on the Middlebury datasets, which shows that our method performs almost 20% better than other “fused” algorithms in the aspect of precision. PMID:26308003

  19. Higher resolution stimulus facilitates depth perception: MT+ plays a significant role in monocular depth perception.

    PubMed

    Tsushima, Yoshiaki; Komine, Kazuteru; Sawahata, Yasuhito; Hiruma, Nobuyuki

    2014-10-20

    Today, we human beings are facing with high-quality virtual world of a completely new nature. For example, we have a digital display consisting of a high enough resolution that we cannot distinguish from the real world. However, little is known how such high-quality representation contributes to the sense of realness, especially to depth perception. What is the neural mechanism of processing such fine but virtual representation? Here, we psychophysically and physiologically examined the relationship between stimulus resolution and depth perception, with using luminance-contrast (shading) as a monocular depth cue. As a result, we found that a higher resolution stimulus facilitates depth perception even when the stimulus resolution difference is undetectable. This finding is against the traditional cognitive hierarchy of visual information processing that visual input is processed continuously in a bottom-up cascade of cortical regions that analyze increasingly complex information such as depth information. In addition, functional magnetic resonance imaging (fMRI) results reveal that the human middle temporal (MT+) plays a significant role in monocular depth perception. These results might provide us with not only the new insight of our neural mechanism of depth perception but also the future progress of our neural system accompanied by state-of- the-art technologies.

  20. Light-induced changes in magnetism in a coordination polymer heterostructure, Rb0.24Co[Fe(CN)6]0.74@K0.10Co[Cr(CN)6]0.70·nH2O and the role of the shell thickness on the properties of both core and shell.

    PubMed

    Risset, Olivia N; Quintero, Pedro A; Brinzari, Tatiana V; Andrus, Matthew J; Lufaso, Michael W; Meisel, Mark W; Talham, Daniel R

    2014-11-01

    Particles of formula Rb0.24Co[Fe(CN)6]0.74@K0.10Co[Cr(CN)6]0.70·nH2O with a light-responsive rubidium cobalt hexacyanoferrate (RbCoFe) core and a magnetic potassium cobalt hexacyanochromate (KCoCr) shell have been prepared and exhibit light-induced changes in the magnetization of the normally light-insensitive KCoCr shell, a new property resulting from the synergy between the core and shell of a coordination polymer heterostructure. A single batch of 135 ± 12 nm RbCoFe particles are used as seeds to generate three different core@shell samples, with KCoCr shell thicknesses of approximately 11, 23 and 37 nm, to probe the influence of the shell thickness over the particles' morphology and structural and magnetic properties. Synchrotron powder X-ray diffraction reveals that structural changes in the shell accompany the charge transfer induced spin transition (CTIST) of the core, giving direct evidence that the photomagnetic response of the shell is magnetomechanical in origin. The depth to which the KCoCr shell contributes to changes in magnetization is estimated to be approximately 24 nm when using a model that assumes a constant magnetic response of the core within the series of particles. In turn, the presence of the shell changes the nature of the CTIST of the core. As opposed to the usually observed first order transition exhibiting hysteresis, the CTIST becomes continuous in the core@shell particles.