Alkaline earth filled nickel skutterudite antimonide thermoelectrics
Singh, David Joseph
2013-07-16
A thermoelectric material including a body centered cubic filled skutterudite having the formula A.sub.xFe.sub.yNi.sub.zSb.sub.12, where A is an alkaline earth element, x is no more than approximately 1.0, and the sum of y and z is approximately equal to 4.0. The alkaline earth element includes guest atoms selected from the group consisting of Be, Mb, Ca, Sr, Ba, Ra and combinations thereof. The filled skutterudite is shown to have properties suitable for a wide variety of thermoelectric applications.
Wigner, E.P.; Young, G.J.
1958-09-23
ABS>A radiation shield that is suitable for the protection of personnel from both gamma rays and nentrons is described. The shield is comprised of a hollow wall and an aggregate consisting of iron and water in approximately equal amounts by volume substantially filling the wall. A means is provided to circulate the water through the wall to cool the shield when in use.
Wiley, Jeffrey B.; Evaldi, Ronald D.; Eychaner, James H.; Chambers, Douglas B.
2001-01-01
The effects of mountaintop removal coal mining and the valley fills created by this mining method in southern West Virginia were investigated by comparing data collected at valley-fill, mined, and unmined sites. Bed material downstream of valley-fill sites had a greater number of particles less than 2 millimeters and a smaller median particle size than the mined and unmined sites. At the 84th percentile of sampled data, however, bed material at each site type had about the same size particles. Bankfull cross-sectional areas at a riffle section were approximately equal at valley-fill and unmined sites, but not enough time has passed and insufficient streamflows since the land was disturbed may have prevented the stream channel at valley-fill sites from reaching equilibrium. The 90-percent flow durations at valley-fill sites generally were 6-7 times greater than at unmined sites. Some valley-fill sites, however, exhibited streamflows similar to unmined sites, and some unmined sites exhibited streamflows similar to valley-fill sites. Daily streamflows from valley-fill sites generally are greater than daily streamflows from unmined sites during periods of low streamflow. Valley-fill sites have a greater percentage of base-flow and a lower percentage of flow from storm runoff than unmined sites. Water temperatures from a valley-fill site exhibited lower daily fluctuations and seasonal variations than water temperatures from an unmined site.
Transcript for Understanding Medical Words: A Tutorial
... Echo equals using ultrasonic waves. Electro equals using electricity. Here are some endings about tests and procedures. ... Define: A picture taken of the heart using electricity. [fill in the blank] -cardio- [fill in the ...
Weiss oscillations and particle-hole symmetry at the half-filled Landau level
NASA Astrophysics Data System (ADS)
Cheung, Alfred K. C.; Raghu, S.; Mulligan, Michael
2017-06-01
Particle-hole symmetry in the lowest Landau level of the two-dimensional electron gas requires the electrical Hall conductivity to equal ±e2/2 h at half filling. We study the consequences of weakly broken particle-hole symmetry for magnetoresistance oscillations about half filling in the presence of an applied periodic one-dimensional electrostatic potential using the Dirac composite fermion theory proposed by Son [Son, Phys. Rev. X 5, 031027 (2015), 10.1103/PhysRevX.5.031027]. At fixed electron density, the oscillation minima are asymmetrically biased towards higher magnetic fields, while at fixed magnetic field the oscillations occur symmetrically as the electron density is varied about half filling. We find an approximate "sum rule" obeyed for all pairs of oscillation minima that can be tested in experiment. The locations of the magnetoresistance oscillation minima for the composite fermion theory of Halperin, Lee, and Read (HLR) and its particle-hole conjugate agree exactly. Within the current experimental resolution, the locations of the oscillation minima produced by the Dirac composite fermion coincide with those of HLR. These results may indicate that all three composite fermion theories describe the same long-wavelength physics.
Weiss oscillations and particle-hole symmetry at the half-filled Landau level
Cheung, Alfred K. C.; Raghu, S.; Mulligan, Michael
2017-06-15
Particle-hole symmetry in the lowest Landau level of the two-dimensional electron gas requires the electrical Hall conductivity to equal ± e 2/2h at half filling. Here, we study the consequences of weakly broken particle-hole symmetry for magnetoresistance oscillations about half filling in the presence of an applied periodic one-dimensional electrostatic potential using the Dirac composite fermion theory proposed by Son [Son, Phys. Rev. X 5, 031027 (2015)]. At fixed electron density, the oscillation minima are asymmetrically biased towards higher magnetic fields, while at fixed magnetic field the oscillations occur symmetrically as the electron density is varied about half filling. Wemore » find an approximate “sum rule” obeyed for all pairs of oscillation minima that can be tested in experiment. The locations of the magnetoresistance oscillation minima for the composite fermion theory of Halperin, Lee, and Read (HLR) and its particle-hole conjugate agree exactly. Within the current experimental resolution, the locations of the oscillation minima produced by the Dirac composite fermion coincide with those of HLR. These results may indicate that all three composite fermion theories describe the same long-wavelength physics.« less
Weiss oscillations and particle-hole symmetry at the half-filled Landau level
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cheung, Alfred K. C.; Raghu, S.; Mulligan, Michael
Particle-hole symmetry in the lowest Landau level of the two-dimensional electron gas requires the electrical Hall conductivity to equal ± e 2/2h at half filling. Here, we study the consequences of weakly broken particle-hole symmetry for magnetoresistance oscillations about half filling in the presence of an applied periodic one-dimensional electrostatic potential using the Dirac composite fermion theory proposed by Son [Son, Phys. Rev. X 5, 031027 (2015)]. At fixed electron density, the oscillation minima are asymmetrically biased towards higher magnetic fields, while at fixed magnetic field the oscillations occur symmetrically as the electron density is varied about half filling. Wemore » find an approximate “sum rule” obeyed for all pairs of oscillation minima that can be tested in experiment. The locations of the magnetoresistance oscillation minima for the composite fermion theory of Halperin, Lee, and Read (HLR) and its particle-hole conjugate agree exactly. Within the current experimental resolution, the locations of the oscillation minima produced by the Dirac composite fermion coincide with those of HLR. These results may indicate that all three composite fermion theories describe the same long-wavelength physics.« less
Characteristics of plasma-puff trigger for a inverse-pinch plasma switch
NASA Technical Reports Server (NTRS)
Choi, Eun H.; Venable, Demetrius D.; Han, Kwang S.; Lee, Ja H.
1993-01-01
The plasma-puff triggering mechanism based on a hypocycloidal pinch geometry was investigated to determine the optimal operating conditions for the azimuthally uniform surface flashover which initiates plasma-puff under wide ranges of fill gas pressure of Ar, He and N2. The optimal fill-gas pressure range for the azimuthally uniform plasma-puff was about 120 mTorr less than or equal to P(sub op) less than or equal to 450 Torr for He and N2. For Argon 120 mTorr is less than or equal to P(sub op) is less than or equal to 5 Torr. The inverse-pinch switch was triggered with the plasma-puff and the switching capability under various electrical parameters and working gas pressures of Ar, He and N2 was determined. The azimuthally uniform switching discharges were dependent on the type of fill gas and its fill pressure. A new concept of plasma-focus driven plasma-puff will be discussed in comparison with the current hypocycloidal-pinch plasma-puff triggering.
Infrared spectroscopy of Landau levels of graphene.
Jiang, Z; Henriksen, E A; Tung, L C; Wang, Y-J; Schwartz, M E; Han, M Y; Kim, P; Stormer, H L
2007-05-11
We report infrared studies of the Landau level (LL) transitions in single layer graphene. Our specimens are density tunable and show in situ half-integer quantum Hall plateaus. Infrared transmission is measured in magnetic fields up to B=18 T at selected LL fillings. Resonances between hole LLs and electron LLs, as well as resonances between hole and electron LLs, are resolved. Their transition energies are proportional to sqrt[B], and the deduced band velocity is (-)c approximately equal to 1.1 x 10(6) m/s. The lack of precise scaling between different LL transitions indicates considerable contributions of many-particle effects to the infrared transition energies.
Naff, Richard L.; Banta, Edward R.
2008-01-01
The preconditioned conjugate gradient with improved nonlinear control (PCGN) package provides addi-tional means by which the solution of nonlinear ground-water flow problems can be controlled as compared to existing solver packages for MODFLOW. Picard iteration is used to solve nonlinear ground-water flow equations by iteratively solving a linear approximation of the nonlinear equations. The linear solution is provided by means of the preconditioned conjugate gradient algorithm where preconditioning is provided by the modi-fied incomplete Cholesky algorithm. The incomplete Cholesky scheme incorporates two levels of fill, 0 and 1, in which the pivots can be modified so that the row sums of the preconditioning matrix and the original matrix are approximately equal. A relaxation factor is used to implement the modified pivots, which determines the degree of modification allowed. The effects of fill level and degree of pivot modification are briefly explored by means of a synthetic, heterogeneous finite-difference matrix; results are reported in the final section of this report. The preconditioned conjugate gradient method is coupled with Picard iteration so as to efficiently solve the nonlinear equations associated with many ground-water flow problems. The description of this coupling of the linear solver with Picard iteration is a primary concern of this document.
Response of the Higgs amplitude mode of superfluid Bose gases in a three-dimensional optical lattice
NASA Astrophysics Data System (ADS)
Nagao, Kazuma; Takahashi, Yoshiro; Danshita, Ippei
2018-04-01
We study the Higgs mode of superfluid Bose gases in a three-dimensional optical lattice, which emerges near the quantum phase transition to the Mott insulator at commensurate fillings. Specifically, we consider responses of the Higgs mode to temporal modulations of the onsite interaction and the hopping energy. In order to calculate the response functions including the effects of quantum and thermal fluctuations, we map the Bose-Hubbard model onto an effective pseudospin-1 model and use a perturbative expansion based on the imaginary-time Green's function theory. We also include the effects of an inhomogeneous trapping potential by means of a local density approximation. We find that the response function for the hopping modulation is equal to that for the interaction modulation within our approximation. At the unit filling rate and in the absence of a trapping potential, we show that the Higgs mode can exist as a sharp resonance peak in the dynamical susceptibilities at typical temperatures. However, the resonance peak is significantly broadened due to the trapping potential when the modulations are applied globally to the entire system. We suggest that the Higgs mode can be detected as a sharp resonance peak by partial modulations around the trap center.
36 CFR 254.11 - Exchanges at approximately equal value.
Code of Federal Regulations, 2010 CFR
2010-07-01
... equal value. 254.11 Section 254.11 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE LANDOWNERSHIP ADJUSTMENTS Land Exchanges § 254.11 Exchanges at approximately equal value. (a) The authorized officer may exchange lands which are of approximately equal value upon a determination that: (1...
Equal Pay for Comparable Work.
ERIC Educational Resources Information Center
Von Frank, Jane
1980-01-01
Argues that sex discrimination has depressed salaries for jobs filled primarily by women. Shows that under the Equal Pay Act and Title VII, workers in traditionally female occupations can establish equal pay claims. Suggests approaches for developing legal and enforcement standards to deal with discriminatory compensation in traditionally female…
NASA Astrophysics Data System (ADS)
Beck, R.; Carilli, C. L.; Holdaway, M. A.; Klein, U.
1994-12-01
Radio continuum observations of the spiral galaxy NGC 253 with the Effelsberg and Very Large Array (VLA) telescopes reveal polarized emission from the bar and halo regions. Within the bar Faraday depolarization is strong at 1.5 and 5 GHz, due to ionized gas with ne approximately equal 0.1 - 3/cu cm which is mixed with turbulent magnetic fields of approximately equal 17 microG estimated strength. Even at 10 GHz the degree of polarization in the bar is low (only approximately equal 5% east and approximately equal 2% west of the nucleus) due to beam depolarization by unresolved tangled fields. In contrast, the magnetic fields in the halo are highly uniform, as indicated by fractional polarizations up to 40% at 10 GHz. Faraday depolarization in the halo at 1.5 GHz calls for a warm, clumpy gas component with ne approximately equal 0.02/cu cm and approximately equal 6 microG turbulent fields. We detected Faraday rotation in the bar, with rotation measures absolute value of RM approximately equal 100 rad/sq m (between 10 and 5 GHz) having different signs east and west of the nucleus. Below 5 GHz Faraday rotation is strongly reduced by the limited transparency for polarized emission in the bar. Faraday rotation in the halo in two regions at approximately 5 kpc above and below the plane with RM approximately equal -7 rad/sq m between 10 and 1.5 GHz can be ascribed to hot gas with mean value of ne approximately equal 0.002/cu cm and uniform fields along the line of sight of mean value of Bu parallel approximately equal -2 microG. The magnetic field structure in the bar and halo of NGC 253 is best described by the quadrupole-type dynamo mode SO, with a ring-like field in the bar and a field mainly parallel to the plane in a co-rotating halo. A major perturbation occurs in the east where the field is perpendicular to the plane and follows a 'spur'. The galactic wind is suppressed by the dominating plane-parallel field, except along the spur.
46 CFR 38.15-1 - Filling of tanks-TB/ALL.
Code of Federal Regulations, 2010 CFR
2010-10-01
... which tank may be loaded. V=volume of tank. d r=density of cargo at the temperature required for a cargo vapor pressure equal to the relief valve setting. d L=density of cargo at the loading temperature and pressure. (b) Nonrefrigerated tanks shall be filled so that their filling densities shall not exceed the...
46 CFR 38.15-1 - Filling of tanks-TB/ALL.
Code of Federal Regulations, 2013 CFR
2013-10-01
... which tank may be loaded. V=volume of tank. d r=density of cargo at the temperature required for a cargo vapor pressure equal to the relief valve setting. d L=density of cargo at the loading temperature and pressure. (b) Nonrefrigerated tanks shall be filled so that their filling densities shall not exceed the...
46 CFR 38.15-1 - Filling of tanks-TB/ALL.
Code of Federal Regulations, 2014 CFR
2014-10-01
... which tank may be loaded. V=volume of tank. d r=density of cargo at the temperature required for a cargo vapor pressure equal to the relief valve setting. d L=density of cargo at the loading temperature and pressure. (b) Nonrefrigerated tanks shall be filled so that their filling densities shall not exceed the...
46 CFR 38.15-1 - Filling of tanks-TB/ALL.
Code of Federal Regulations, 2012 CFR
2012-10-01
... which tank may be loaded. V=volume of tank. d r=density of cargo at the temperature required for a cargo vapor pressure equal to the relief valve setting. d L=density of cargo at the loading temperature and pressure. (b) Nonrefrigerated tanks shall be filled so that their filling densities shall not exceed the...
A Distributive, Non-Destructive, Real-Time Approach to Snowpack Monitoring
NASA Technical Reports Server (NTRS)
Frolik, Jeff; Skalka, Christian
2012-01-01
This invention is designed to ascertain the snow water equivalence (SWE) of snowpacks with better spatial and temporal resolutions than present techniques. The approach is ground-based, as opposed to some techniques that are air-based. In addition, the approach is compact, non-destructive, and can be communicated with remotely, and thus can be deployed in areas not possible with current methods. Presently there are two principal ground-based techniques for obtaining SWE measurements. The first is manual snow core measurements of the snowpack. This approach is labor-intensive, destructive, and has poor temporal resolution. The second approach is to deploy a large (e.g., 3x3 m) snowpillow, which requires significant infrastructure, is potentially hazardous [uses a approximately equal to 200-gallon (approximately equal to 760-L) antifreeze-filled bladder], and requires deployment in a large, flat area. High deployment costs necessitate few installations, thus yielding poor spatial resolution of data. Both approaches have limited usefulness in complex and/or avalanche-prone terrains. This approach is compact, non-destructive to the snowpack, provides high temporal resolution data, and due to potential low cost, can be deployed with high spatial resolution. The invention consists of three primary components: a robust wireless network and computing platform designed for harsh climates, new SWE sensing strategies, and algorithms for smart sampling, data logging, and SWE computation.
2003-09-02
KENNEDY SPACE CENTER, FLA. - Storage boxes filled with Columbia debris (left) await transfer to storage in the Vehicle Assembly Building. Empty boxes at right wait to be filled with more of the approximately 83,000 pieces shipped to KSC during search and recovery efforts in East Texas.
Microstructures of Pd-containing dispersants for admixed dental amalgams.
Chern Lin, J H; Greener, E H
1991-10-01
Blended Pd-containing dispersants were developed by the utilization of a Ag-Cu eutectic into which Pd was substituted for Ag or Cu in concentrations of up to 20 wt%. Compositions were melted either in argon-filled sealed vycor tubes or in a graphite-linked carbon crucible of an induction furnace with an argon blanket. Ingots of approximately 1.5 cm in diameter were sectioned to 0.2 cm in thickness and polished through standard metallographic polishing procedures. The possible compounds were identified by XRD. The microstructures of the alloys were examined by SEM/EDS. XRD analysis of the alloys revealed the preferential dissolution of Pd in Cu when the Pd concentration was less than or equal to 10 wt%. When the Pd concentration exceeded 20 wt%, Pd was found to be dissolved in both Ag and Pd. No Cu3Pd x-ray diffraction peaks were found for alloys with Pd concentration of up to 20 wt%. SEM/EDS analysis confirmed XRD results; lamellae of Ag and Cu-Pd were found in alloys with Pd concentration less than or equal to 10 wt%.
Investigations of ionospheric sporadic Es layer using oblique sounding method
NASA Astrophysics Data System (ADS)
Minullin, R.
The characteristics of Es layer have been studied using oblique sounding at 28 radiolines at the frequencies of 34 -- 73 MHz at the transmission paths 400 -- 1600 km long during 30 years. Reflections from Es layer with a few hours duration were observed. The amplitude of the reflected signal reached 1000 μ V with the registration threshold 0,1 μ V. The borderlines between reflected and scattered signals were observed as sharp curves in 60 -- 100 s range on the distributions of duration of reflected signals for decameter waves. The duration of continuous Es reflections were decreased upon amplification of oblique sounding frequency. The distributions of duration of reflected signals for meter waves showed sharp curves in the range 200 -- 300 s, representing borderlines between signals reflected from meteoric traces and from Es layer. The filling coefficient for the oblique sounding as well as the Es layer emersion probability for the vertical sounding were shown to undergo daily, seasonal and periodic variations. The daily variations of the filling coefficient of Es signals showed clear-cut maximums at 10 -- 12 and 18 -- 20 hours and minimum at 4 -- 6 hours at all paths in summer time and the maximum at 12 -- 14 hours in winter time. The values of the filling coefficient for Es layer declined with the increase of oblique sounding frequency. The minimal values of the filling coefficient were observed in winter and early spring, while the maximal values were observed from May to August. Provided that the averaged filling coefficient is equal to one in summer, it reaches the level 0,25 in equinox and does not exceed the level 0,12 in winter as evident by the of oblique sounding. The filling coefficient relation to the value of the voltage detection threshold was approximated by power-mode law. The filling coefficients for summer period showed exponential relation with equivalent sounding frequencies. The experimental evidence was generalized in an analytical model. Using this model the averaged Es layer filling coefficients for particular season of the year can be forecasted in case of given sounding frequency, path length, and voltage threshold.
Fluid dynamics following flow shut-off in bottle filling
NASA Astrophysics Data System (ADS)
Thete, Sumeet; Appathurai, Santosh; Gao, Haijing; Basaran, Osman
2012-11-01
Bottle filling is ubiquitous in industry. Examples include filling of bottles with shampoos and cleaners, engine oil and pharmaceuticals. In these examples, fluid flows out of a nozzle to fill bottles in an assembly line. Once the required volume of fluid has flowed out of the nozzle, the flow is shut off. However, an evolving fluid thread or string may remain suspended from the nozzle following flow shut-off and persist. This stringing phenomenon can be detrimental to a bottle filling operation because it can adversely affect line speed and filling accuracy by causing uncertainty in fill volume, product loss and undesirable marring of the bottles' exterior surfaces. The dynamics of stringing are studied numerically primarily by using the 1D, slender-jet approximation of the flow equations. A novel feature entails development and use of a new boundary condition downstream of the nozzle exit to expedite the computations. While the emphasis is on stringing of Newtonian fluids and use of 1D approximations, results will also be presented for situations where (a) the fluids are non-Newtonian and (b) the full set of equations are solved without invoking the 1D approximation. Phase diagrams will be presented that identify conditions for which stringing can be problematic.
Using Thin-Film Thermometers as Heaters in Thermal Control Applications
NASA Technical Reports Server (NTRS)
Cho, Hyung J.; Penanen, Konstantin; Sukhatme, Kalyani G.; Holmes, Warren A.; Courts, Scott
2010-01-01
A cryogenic sensor maintains calibration at approximately equal to 4.2 K to better than 2 mK (< 0.5 percent resistance repeatability) after being heated to approximately equal 40 K with approximately equal 0.5 W power. The sensor withstands 4 W power dissipation when immersed in liquid nitrogen with verified resistance reproducibility of, at worst, 1 percent. The sensor maintains calibration to 0.1 percent after being heated with 1-W power at approximately equal 77 K for a period of 48 hours. When operated with a readout scheme that is capable of mitigating the self-heating calibration errors, this and similar sensors can be used for precision (mK stability) temperature control without the need of separate heaters and associated wiring/cabling.
Streptococcus mutans levels and caries prevalence in low-income schoolchildren.
Seibert, Wilda; Farmer-Dixon, Cherae; Bolden, Theodore; Stewart, James H
2002-01-01
Previous studies have shown that persons having high Streptococcus mutans levels in the saliva are "at risk" for dental caries. Most investigators agree, that if high levels of S. mutans were identified early in the life of at-risk children, dental decay could be reduced or eliminated through intervention. The purpose of this study is to show an association between S. mutans levels and caries prevalence in a sample of elementary school children. The study group consisted of 242 school children, ages 5-13 years. The subjects were divided into two age groups, 5-8 years and 9-13 years. Approximately 59 percent were African Americans. The sample of 242 children were equally females and males, 50 percent in each group. The Dentocult SM Test was used to make S. mutans determinations. The df-t index was used to determine the number of decayed and filled teeth of children ages 5-8 years; the DMF-T Index estimated the number of decayed, missing or filled teeth of children ages 9-13 years. Dental caries were found in 58 percent of the children (mean = 2.67, and range of 1-11). Approximately 47 percent of the children with caries had high S. mutans levels (100K-1M). Females had higher S. mutans levels than males in the 9-13 age group, p < .05. Analysis of Variance Test indicated that S. mutans levels for older females (ages 9-13) were significantly higher than those observed in males the same age (p < .01). This trend was not observed in younger children, ages 5-8 years. In addition, no significant difference or interaction was noted by sex for S. mutans levels and decayed or filled teeth (df-t) for younger children. We conclude that high levels of Streptococcus mutans are related to increased number of decayed teeth and conversely, low Streptococcus mutans levels are related to fewer dental caries. This study was supported in part by Colgate-Palmolive Company and the National Dental Association Foundation, Inc.
Measuring Air Leaks into the Vacuum Space of Large Liquid Hydrogen Tanks
NASA Technical Reports Server (NTRS)
Youngquist, Robert; Starr, Stanley; Nurge, Mark
2012-01-01
Large cryogenic liquid hydrogen tanks are composed of inner and outer shells. The outer shell is exposed to the ambient environment while the inner shell holds the liquid hydrogen. The region between these two shells is evacuated and typically filled with a powderlike insulation to minimize radiative coupling between the two shells. A technique was developed for detecting the presence of an air leak from the outside environment into this evacuated region. These tanks are roughly 70 ft (approx. equal 21 m) in diameter (outer shell) and the inner shell is roughly 62 ft (approx. equal 19 m) in diameter, so the evacuated region is about 4 ft (approx. equal 1 m) wide. A small leak's primary effect is to increase the boil-off of the tank. It was preferable to install a more accurate fill level sensor than to implement a boil-off meter. The fill level sensor would be composed of an accurate pair of pressure transducers that would essentially weigh the remaining liquid hydrogen. This upgrade, allowing boil-off data to be obtained weekly instead of over several months, is ongoing, and will then provide a relatively rapid indication of the presence of a leak.
29 CFR 1620.16 - Jobs requiring equal effort in performance.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 1620.16 Labor Regulations Relating to Labor (Continued) EQUAL EMPLOYMENT OPPORTUNITY COMMISSION THE... factors which cause mental fatigue and stress, as well as those which alleviate fatigue, are to be... portion of her time to performing fill-in work requiring greater dexterity—such as rearranging displays of...
29 CFR 1620.16 - Jobs requiring equal effort in performance.
Code of Federal Regulations, 2012 CFR
2012-07-01
... 1620.16 Labor Regulations Relating to Labor (Continued) EQUAL EMPLOYMENT OPPORTUNITY COMMISSION THE... factors which cause mental fatigue and stress, as well as those which alleviate fatigue, are to be... portion of her time to performing fill-in work requiring greater dexterity—such as rearranging displays of...
29 CFR 1620.16 - Jobs requiring equal effort in performance.
Code of Federal Regulations, 2014 CFR
2014-07-01
... 1620.16 Labor Regulations Relating to Labor (Continued) EQUAL EMPLOYMENT OPPORTUNITY COMMISSION THE... factors which cause mental fatigue and stress, as well as those which alleviate fatigue, are to be... portion of her time to performing fill-in work requiring greater dexterity—such as rearranging displays of...
29 CFR 1620.16 - Jobs requiring equal effort in performance.
Code of Federal Regulations, 2013 CFR
2013-07-01
... 1620.16 Labor Regulations Relating to Labor (Continued) EQUAL EMPLOYMENT OPPORTUNITY COMMISSION THE... factors which cause mental fatigue and stress, as well as those which alleviate fatigue, are to be... portion of her time to performing fill-in work requiring greater dexterity—such as rearranging displays of...
29 CFR 1620.16 - Jobs requiring equal effort in performance.
Code of Federal Regulations, 2011 CFR
2011-07-01
... 1620.16 Labor Regulations Relating to Labor (Continued) EQUAL EMPLOYMENT OPPORTUNITY COMMISSION THE... factors which cause mental fatigue and stress, as well as those which alleviate fatigue, are to be... portion of her time to performing fill-in work requiring greater dexterity—such as rearranging displays of...
NASA Technical Reports Server (NTRS)
Lehmer, B. D.; Lucy, A. B.; Alexander, D. M.; Best, P. N.; Geach, J. E.; Harrison, C. M.; Hornschemeier, A. E.; Matsuda, Y.; Mullaney, J. R.; Smail, Ian;
2013-01-01
We present results from an approximately equal 100 ks Chandra observation of the 2QZ Cluster 1004+00 structure at z = 2.23 (hereafter 2QZ Clus). 2QZ Clus was originally identified as an overdensity of four optically-selected QSOs at z = 2.23 within a 15 × 15 arcmin square region. Narrow-band imaging in the near-IR (within the K band) revealed that the structure contains an additional overdensity of 22 z = 2.23 H alpha-emitting galaxies (HAEs), resulting in 23 unique z = 2.23 HAEs/QSOs (22 within the Chandra field of view). Our Chandra observations reveal that three HAEs in addition to the four QSOs harbor powerfully accreting supermassive black holes (SMBHs), with 2-10 keV luminosities of approximately equal (8-60) × 10(exp 43) erg s(exp-1) and X-ray spectral slopes consistent with unobscured active galactic nucleus (AGN). Using a large comparison sample of 210 z = 2.23 HAEs in the Chandra-COSMOS field (C-COSMOS), we find suggestive evidence that the AGN fraction increases with local HAE galaxy density. The 2QZ Clus HAEs reside in a moderately overdense environment (a factor of approximately equal 2 times over the field), and after excluding optically-selected QSOs, we find that the AGN fraction is a factor of approximately equal 3.5(+3.8/ -2.2) times higher than C-COSMOS HAEs in similar environments. Using stacking analyses of the Chandra data and Herschel SPIRE observations at 250micrometers, we respectively estimate mean SMBH accretion rates ( M(BH)) and star formation rates (SFRs) for the 2QZ Clus and C-COSMOS samples. We find that the mean 2QZ Clus HAE stacked X-ray luminosity is QSO-like (L(2-10 keV) approximately equal [6-10] × 10(exp 43) erg s(exp -1)), and the implied M(BH)/SFR approximately equal (1.6-3.2) × 10(exp -3) is broadly consistent with the local M(BH)/Stellar Mass relation and z approximately equal 2 X-ray selected AGN. In contrast, the C-COSMOS HAEs are on average an order of magnitude less X-ray luminous and have M(BH)/SFR approximately equal (0.2-0.4) × 10(exp -3), somewhat lower than the local MBH/M relation, but comparable to that found for z approximately equal 1-2 star-forming galaxies with similar mean X-ray luminosities. We estimate that a periodic QSO phase with duty cycle approximately 2%-8% would be sufficient to bring star-forming galaxies onto the local M(BH)/Stellar Mass relation. This duty cycle is broadly consistent with the observed C-COSMOS HAE AGN fraction (Approximately equal 0.4%-2.3%) for powerful AGN with LX approximately greater than 10(exp 44) erg s(exp -1). Future observations of 2QZ Clus will be needed to identify key factors responsible for driving the mutual growth of the SMBHs and galaxies.
49 CFR 173.35 - Hazardous materials in IBCs.
Code of Federal Regulations, 2012 CFR
2012-10-01
..., cracks, cuts, or other damage which would render it unable to pass the prescribed design type test to... plastic or composite IBC may only be filled with a liquid having a vapor pressure less than or equal to... -57 portable tanks. (j) No IBC may be filled with a Packing Group I liquid. Rigid plastic, composite...
49 CFR 173.35 - Hazardous materials in IBCs.
Code of Federal Regulations, 2011 CFR
2011-10-01
... plastic or composite IBC may only be filled with a liquid having a vapor pressure less than or equal to... -57 portable tanks. (j) No IBC may be filled with a Packing Group I liquid. Rigid plastic, composite... point of 60 °C (140 °F) (closed cup) or lower, or powders with the potential for dust explosion...
VLBI observations of the nucleus of Centaurus A
NASA Technical Reports Server (NTRS)
Preston, R. A.; Wehrle, A. E.; Morabito, D. D.; Jauncey, D. L.; Batty, M. J.; Haynes, R. F.; Wright, A. E.; Nicolson, G. D.
1983-01-01
VLBI observations of the nucleus of Centaurus A made at 2.3 GHz on baselines with minimum fringe spacings of 0.15 and 0.0027 arcsec are presented. Results show that the nuclear component is elongated with a maximum extent of approximately 0.05 arcsec which is equivalent to a size of approximately 1 pc at the 5 Mpc distance of Centaurus A. The position angle of the nucleus is found to be 30 + or - 20 degrees, while the ratio of nuclear jet length to width is less than or approximately equal to 20. The nuclear flux density is determined to be 6.8 Jy, while no core component is found with an extent less than or approximately equal to 0.001 (less than or approximately equal to 0.02 pc) with a flux density of greater than or approximately equal to 20 mJy. A model of the Centaurus A nucleus composed of at least two components is developed on the basis of these results in conjunction with earlier VLBI and spectral data. The first component is an elongated source of approximately 0.05 arcsec (approximately 1 pc) size which contains most of the 2.3 GHz nuclear flux, while the second component is a source of approximately 0.0005 arcsec (approximately 0.01 pc) size which is nearly completely self-absorbed at 2.3 GHz but strengthens at higher frequencies.
Soot Superaggregates from Flaming Wildfires and Their Direct Radiative Forcing
NASA Technical Reports Server (NTRS)
Chakrabarty, Rajan K.; Beres, Nicholas D.; Moosmuller,Hans; China, Swarup; Mazzoleni, Claudio; Dubey, Manvendra K.; Liu, Li; Mishchenko, Michael I.
2014-01-01
Wildfires contribute significantly to global soot emissions, yet their aerosol formation mechanisms and resulting particle properties are poorly understood and parameterized in climate models. The conventional view holds that soot is formed via the cluster-dilute aggregation mechanism in wildfires and emitted as aggregates with fractal dimension D(sub f) approximately equals 1.8 mobility diameter D(sub m) (is) less than or equal to 1 micron, and aerodynamic diameter D(sub a) (is) less than or equal to 300 nm. Here we report the ubiquitous presence of soot superaggregates (SAs) in the outflow from a major wildfire in India. SAs are porous, low-density aggregates of cluster-dilute aggregates with characteristic D(sub f) approximately equals 2.6,D(sub m) (is) greater than 1 micron, and D(sub a) is less than or equal to 300 nm that form via the cluster-dense aggregation mechanism.We present additional observations of soot SAs in wildfire smoke-laden air masses over Northern California, New Mexico, and Mexico City. We estimate that SAs contribute, per unit optical depth, up to 35% less atmospheric warming than freshly-emitted (D(sub f) approximately equals 1.8) aggregates, and approximately equals 90% more warming than the volume-equivalent spherical soot particles simulated in climate models.
Evidence for Reduced Species Star Formation Rates in the Centers of Massive Galaxies at zeta = 4
NASA Technical Reports Server (NTRS)
Jung, Intae; Finkelstein, Steven L.; Song, Mimi; Dickinson, Mark; Dekel, Avishai; Ferguson, Henry C.; Fontana, Adriano; Koekemoer, Anton M.; Lu, Yu; Mobasher, Bahram;
2017-01-01
We perform the first spatially-resolved stellar population study of galaxies in the early universe z equals 3.5 -6.5, utilizing the Hubble Space Telescope Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) imaging dataset over the GOODS-S field. We select a sample of 418 bright and extended galaxies at z less than or approximately equal to 3.5-6.5 from a parent sample of approximately 8000 photometric-redshift selected galaxies from Finkelstein et al. We first examine galaxies at 3.5 less than or equal to z less than or approximately equal to 4.0 using additional deep K-band survey data from the HAWK-I UDS and GOODS Survey (HUGS) which covers the 4000 Angstrom break at these redshifts. We measure the stellar mass, star formation rate, and dust extinction for galaxy inner and outer regions via spatially-resolved spectral energy distribution fitting based on a Markov Chain Monte Carlo algorithm. By comparing specific star formation rates (sSFRs) between inner and outer parts of the galaxies we find that the majority of galaxies with the high central mass densities show evidence for a preferentially lower sSFR in their centers than in their outer regions, indicative of reduced sSFRs in their central regions. We also study galaxies at z approximately equal to 5 and 6 (here limited to high spatial resolution in the rest-frame ultraviolet only), finding that they show sSFRs which are generally independent of radial distance from the center of the galaxies. This indicates that stars are formed uniformly at all radii in massive galaxies at z approximately equal to 5-6, contrary tomassive galaxies at z. less than approximately equal to 4.
Rüttermann, Stefan; Krüger, Sören; Raab, Wolfgang H-M; Janda, Ralf
2007-10-01
To investigate the polymerization shrinkage and hygroscopic expansion of contemporary posterior resin-based filling materials. The densities of SureFil (SU), CeramXMono (CM), Clearfil AP-X (CF), Solitaire 2 (SO), TetricEvoCeram (TE), and Filtek P60 (FT) were measured using the Archimedes' principle prior to and 15min after curing for 20, 40 and 60s and after 1h, 24h, 7 d, and 30 d storage at 37 degrees C in water. Volumetric changes (DeltaV) in percent after polymerization and after each storage period in water were calculated from the changes of densities. Water sorption and solubility were determined after 30 d for all specimens and their curing times. Two-way ANOVA was calculated for shrinkage and repeated measures ANOVA was calculated for hygroscopic expansion (p<0.05). DeltaV depended on filler load but not on curing time (SU approximately -2.0%, CM approximately -2.6%, CF approximately -2.1%, SO approximately -3.3%, TE approximately -1.7%, FT approximately -1.8%). Hygroscopic expansion depended on water sorption and solubility. Except for SU, all materials showed DeltaV approximately +1% after water storage. Polymerization shrinkage depended on the type of resin-based filling material but not on curing time. Shrinkage was not compensated by hygroscopic expansion.
Opacity, metallicity, and Cepheid period ratios in the galaxy and Magellanic Clouds
NASA Technical Reports Server (NTRS)
Simon, Norman R.; Kanbur, Shashi M.
1994-01-01
Linear pulsation calculations are employed to reproduce the bump Cepheid resonance (P(sub 2)/P(sub 0) = 0.5 at P(sub 0) approximately equal to 10 days) and to model, individually, the P(sub 1)/P(sub 0) period ratios for the dozen known Galactic beat Cepheids. Convection is ignored. The results point to a range of metallicity among the Cepheids, perhaps as large as 0.01 approximately less than Z approximately less than 0.02, with no evidence for any star exceeding Z = 0.02. We find masses and luminosities which range from M approximately less than 4 solar mass, log(base 10) approximately less than 3.0 at P(sub 0) approximately equal to 3 days to M approximately less than 6 solar mass, log(base 10) L approximately greater than 3.5 at P(sub 0) approximately equal to 10 days. Similar parameters are indicated for the P(sub 0) approximately equal to 10 days Cepheids in the LMC and SMC, provided that the resonance for these stars occurs at a slightly longer period, P(sub 0) days, as has been suggested in the literature. Our calculations were performed mainly using OPAL opacities, but also with new opacities from the Opacity project (OP). Only small differences were found between the OPAL results and those from OP. Finally, some suggestions are made for possible future work, including evolution and pulsation calculations, and more precise observations of Cepheids in the Magellanic Clouds.
Trumble, S J; Barboza, P S; Castellini, M A
2003-08-01
We hypothesized that increased feeding frequency in captive harbor seals would increase nutrient loads and thus reduce retention time and the digestive efficiency of natural prey. We measured daily feed intake and excretion during 6 feeding trials and fed herring (49% lipid), pollock (22% lipid) or an equal mix of each diet over 24 months. Animals were accustomed to feeding at either high or low frequency. Body mass and intake did not vary with season. Although mean retention times were similar between diets and feeding frequencies, solute and particulate digesta markers separated at high feeding frequency. Consistent dry matter digestibility resulted in greater gut fill from pollock than from herring. Digestible energy intakes from pollock were approximately 25% greater than from either herring or the mixed diet. Lipid digestibility of herring declined from 90% to 50% when lipid intake exceeded 60 g kg(-0.75) day(-1). Our hypothesis of a trade-off between intake and digestion was not supported for protein but was supported for lipid. Results of this study imply that a flexible digestive system for harbor seals can compensate for ingesting prey of lower energy density by increasing gut fill and enhancing protein and lipid assimilation, to sustain digestible energy intake.
Mauda, R.; Pinchas, M.
2014-01-01
Recently a new blind equalization method was proposed for the 16QAM constellation input inspired by the maximum entropy density approximation technique with improved equalization performance compared to the maximum entropy approach, Godard's algorithm, and others. In addition, an approximated expression for the minimum mean square error (MSE) was obtained. The idea was to find those Lagrange multipliers that bring the approximated MSE to minimum. Since the derivation of the obtained MSE with respect to the Lagrange multipliers leads to a nonlinear equation for the Lagrange multipliers, the part in the MSE expression that caused the nonlinearity in the equation for the Lagrange multipliers was ignored. Thus, the obtained Lagrange multipliers were not those Lagrange multipliers that bring the approximated MSE to minimum. In this paper, we derive a new set of Lagrange multipliers based on the nonlinear expression for the Lagrange multipliers obtained from minimizing the approximated MSE with respect to the Lagrange multipliers. Simulation results indicate that for the high signal to noise ratio (SNR) case, a faster convergence rate is obtained for a channel causing a high initial intersymbol interference (ISI) while the same equalization performance is obtained for an easy channel (initial ISI low). PMID:24723813
NASA Technical Reports Server (NTRS)
Paciesas, W. S.; Baker, R.; Boclet, D.; Brown, S.; Cline, T.; Costlow, H.; Durouchoux, P.; Ehrmann, C.; Gehrels, N.; Hameury, J. M.
1983-01-01
The Low Energy Gamma ray Spectrometer (LEGS) is designed to perform fine energy resolution measurements of astrophysical sources. The instrument is configured for a particular balloon flight with either of two sets of high purity germanium detectors. In one configuration, the instrument uses an array of three coaxial detectors (effective volume equal to or approximately 230 cubic cm) inside an NaI (T1) shield and collimator (field of view equal to or approximately 16 deg FWHM) and operates in the 80 to 8000 keV energy range. In the other configuration, three planar detectors (effective area equal to or approximately square cm) surrounded by a combination of passive Fe and active NaI for shielding and collimation (field of view equal to or approximately 5 deg x 10 deg FWHM) are optimized for the 20 to 200 keV energy range. In a typical one day balloon flight, LEGS sensitivity limit (3 sigma) for narrow line features is less than or approximately .0008 ph/cm/s square (coaxial array: 80 to 2000 keV) and less than or approximately .0003 ph/square cm/s (planar array: 50 to 150 keV).
Beisner, Kimberly R.; Anning, David W.; Paul, Angela P.; McKinney, Tim S.; Huntington, Jena M.; Bexfield, Laura M.; Thiros, Susan A.
2012-01-01
Human-health concerns and economic considerations associated with meeting drinking-water standards motivated a study of the vulnerability of basin-fill aquifers to nitrate contamination and arsenic enrichment in the southwestern United States. Statistical models were developed by using the random forest classifier algorithm to predict concentrations of nitrate and arsenic across a model grid representing about 190,600 square miles of basin-fill aquifers in parts of Arizona, California, Colorado, Nevada, New Mexico, and Utah. The statistical models, referred to as classifiers, reflect natural and human-related factors that affect aquifer vulnerability to contamination and relate nitrate and arsenic concentrations to explanatory variables representing local- and basin-scale measures of source and aquifer susceptibility conditions. Geochemical variables were not used in concentration predictions because they were not available for the entire study area. The models were calibrated to assess model accuracy on the basis of measured values.Only 2 percent of the area underlain by basin-fill aquifers in the study area was predicted to equal or exceed the U.S. Environmental Protection Agency drinking-water standard for nitrate as N (10 milligrams per liter), whereas 43 percent of the area was predicted to equal or exceed the standard for arsenic (10 micrograms per liter). Areas predicted to equal or exceed the drinking-water standard for nitrate include basins in central Arizona near Phoenix; the San Joaquin Valley, the Santa Ana Inland, and San Jacinto Basins of California; and the San Luis Valley of Colorado. Much of the area predicted to equal or exceed the drinking-water standard for arsenic is within a belt of basins along the western portion of the Basin and Range Physiographic Province that includes almost all of Nevada and parts of California and Arizona. Predicted nitrate and arsenic concentrations are substantially lower than the drinking-water standards in much of the study area-about 93 percent of the area underlain by basin-fill aquifers was less than one-half the standard for nitrate as N (5.0 milligrams per liter), and 50 percent was less than one-half the standard for arsenic (5.0 micrograms per liter). The predicted concentrations and the improved understanding of the susceptibility and vulnerability of southwestern basin-fill aquifers to nitrate contamination and arsenic enrichment can be used by water managers as a qualitative tool to assess and protect the quality of groundwater resources in the Southwest.
The role of biofeedback in the treatment of gastrointestinal disorders.
Chiarioni, Giuseppe; Whitehead, William E
2008-07-01
Biofeedback is a form of treatment that has no adverse effects and can be provided by physician extenders. The therapy relies on patients' ability to learn how to influence their bodily functions through dedicated machinery and teaching. This Review provides a comprehensive overview of all potential therapeutic applications of biofeedback for functional constipation, fecal incontinence, functional anorectal pain, IBS, functional dyspepsia, and aerophagia. Practical clinical applications of biofeedback therapy supported by randomized, controlled trials (RCTs) are limited to fecal incontinence and dyssynergic defecation. For fecal incontinence, RCTs suggest that biofeedback combining strength training and sensory discrimination training is effective in approximately 75% of patients and is more effective than placebo. However, verbal feedback provided by a therapist during extended digital examination may be equally effective, and children whose fecal incontinence is associated with constipation plus fecal impaction do no better with biofeedback than medical management. For dyssynergic defecation, RCTs show that biofeedback combining pelvic floor muscle relaxation training, practice in defecating a water-filled balloon, and instruction in effective straining is effective in approximately 70% of patients who have failed to respond to laxative treatment. For both incontinence and dyssynergic defecation, the benefits of biofeedback last at least 12 months.
Anning, David W.; Paul, Angela P.; McKinney, Tim S.; Huntington, Jena M.; Bexfield, Laura M.; Thiros, Susan A.
2012-01-01
The National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey (USGS) is conducting a regional analysis of water quality in the principal aquifer systems across the United States. The Southwest Principal Aquifers (SWPA) study is building a better understanding of the susceptibility and vulnerability of basin-fill aquifers in the region to groundwater contamination by synthesizing baseline knowledge of groundwater-quality conditions in 16 basins previously studied by the NAWQA Program. The improved understanding of aquifer susceptibility and vulnerability to contamination is assisting in the development of tools that water managers can use to assess and protect the quality of groundwater resources.Human-health concerns and economic considerations associated with meeting drinking-water standards motivated a study of the vulnerability of basin-fill aquifers to nitrate contamination and arsenic enrichment in the southwestern United States. Statistical models were developed by using the random forest classifier algorithm to predict concentrations of nitrate and arsenic across a model grid that represents about 190,600 square miles of basin-fill aquifers in parts of Arizona, California, Colorado, Nevada, New Mexico, and Utah. The statistical models, referred to as classifiers, reflect natural and human-related factors that affect aquifer vulnerability to contamination and relate nitrate and arsenic concentrations to explanatory variables representing local- and basin-scale measures of source, aquifer susceptibility, and geochemical conditions. The classifiers were unbiased and fit the observed data well, and misclassifications were primarily due to statistical sampling error in the training datasets.The classifiers were designed to predict concentrations to be in one of six classes for nitrate, and one of seven classes for arsenic. Each classification scheme allowed for identification of areas with concentrations that were equal to or exceeding the U.S. Environmental Protection Agency drinking-water standard. Whereas 2.4 percent of the area underlain by basin-fill aquifers in the study area was predicted to equal or exceed this standard for nitrate (10 milligrams per liter as N; mg/L), 42.7 percent was predicted to equal or exceed the standard for arsenic (10 micrograms per liter; μg/L). Areas predicted to equal or exceed the drinking-water standard for nitrate include basins in central Arizona near Phoenix; the San Joaquin, Inland, and San Jacinto basins of California; and the San Luis Valley of Colorado. Much of the area predicted to equal or exceed the drinking-water standard for arsenic is within a belt of basins along the western portion of the Basin and Range Physiographic Province in Nevada, California, and Arizona. Predicted nitrate and arsenic concentrations are substantially lower than the drinking-water standards in much of the study area—about 93.0 percent of the area underlain by basin-fill aquifers was less than one-half the standard for nitrate (5.0 mg/L), and 50.2 percent was less than one-half the standard for arsenic (5.0 μg/L).
Plasma-puff initiation of high Coulomb transfer switches
NASA Technical Reports Server (NTRS)
Venable, D. D.; Han, K. S.
1993-01-01
The plasma-puff triggering mechanism based on a hypocycloidal pinch geometry was investigated to determine the optimal operating conditions for an azimuthally uniform surface flashover which initiates plasma-puff under wide ranges of fill gas pressures of Ar, He and N2. The optimal fill gas pressures for the azimuthally uniform plasma-puff were about 120 mTorr less than P(opt) less than 450 Torr for He and N2. For Argon 120 mTorr less than P(opt) less than 5 Torr for argon. The inverse pinch switch was triggered with the plasma-puff and the switching capability under various electrical parameters and working gas pressures of Ar, He and N2 was determined. It was also shown that the azimuthally uniform switching discharges were dependent on the type of fill gas and its fill pressure. A new concept of plasma-focus driven plasma-puff was also discussed in comparison with hypocycloidal pinch plasma-puff triggering. The main discharge of the inverse pinch switch with the plasma-focus driven plasma-puff trigger is found to be more azimuthally uniform than that with the hypocycloidal pinch plasma-puff trigger in a gas pressure region between 80 mTorr and 1 Torr. In order to assess the effects of plasma current density on material erosion of electrodes, emissions from both an inverse-pinch plasma switch (INPIStron) and from a spark gap switch under test were studied with an optical multichannel analyzer (OMA). The color temperature of the argon plasma was approximately 4,000 K which corresponded with the peak continuum emission near 750 nm. There are the strong line emissions of argon in the 650 - 800 nm range and a lack of line emissions of copper and other solid material used in the switch. This indicates that the plasma current density during closing is low and the hot spot or hot filament in the switch is negligible. This result also indicates considerable reduction of line emission with the INPIStron switch over that of a spark-gap switch. However, a strong carbon line emission exists due to vaporization of the plastic insulator used. In order to reduce the vaporization of the insulator, the plexiglass insulating material of INPIStron was replaced with Z-9 material. A comparative study of the INPIStron and a spark gap also reveals that the INPIStron, with a low impedance of Z equals 9 ohms, can transfer a high voltage pulse with a superior pulse-shape fidelity over that of a spark gap with Z equals 100 ohms.
The best-fit universe. [cosmological models
NASA Technical Reports Server (NTRS)
Turner, Michael S.
1991-01-01
Inflation provides very strong motivation for a flat Universe, Harrison-Zel'dovich (constant-curvature) perturbations, and cold dark matter. However, there are a number of cosmological observations that conflict with the predictions of the simplest such model: one with zero cosmological constant. They include the age of the Universe, dynamical determinations of Omega, galaxy-number counts, and the apparent abundance of large-scale structure in the Universe. While the discrepancies are not yet serious enough to rule out the simplest and most well motivated model, the current data point to a best-fit model with the following parameters: Omega(sub B) approximately equal to 0.03, Omega(sub CDM) approximately equal to 0.17, Omega(sub Lambda) approximately equal to 0.8, and H(sub 0) approximately equal to 70 km/(sec x Mpc) which improves significantly the concordance with observations. While there is no good reason to expect such a value for the cosmological constant, there is no physical principle that would rule out such.
A reexamination of the relationship between eddy mixing and O2 in the Martian middle atmosphere
NASA Astrophysics Data System (ADS)
Rosenqvist, Jan; Chassefiere, E.
1995-03-01
A value of the eddy diffusion coefficient K of approximately equals 1.5 x 106 sq cm/s in the middle atmosphere of Mars was obtained from Phobos 2 solar occultation measurements of dust, ozone, and clouds at low latitude. The aim of the present study is to complete this picture by using a steady photochemical one-dimensional model. The main regulation mechanism of O2 is the reaction of O with itself, whose rate depends on the value of K in the middle atmosphere. By comparing calculated and observed values of the O2 abundance, an upper limit of approximately equals 2 x 107/sq cm/s on K is inferred. By including an additional constraint provided by H2 balance, a lower limit of approximately equals 4 x 106/sq cm/s may be placed. It results from the present analysis that the most realistic value of K to be used in works resorting to one-dimensional modeling (long-term evolution, escape, surface/atmosphere exchanges) is approximately equals 107 sq cm/s rather than approximately equals 106 sq cm/s. The difference between theoretical and observational values might be due to the regular occurence of global dust storms, whose effect should be to increase the yearly average value of K. The present study suggests less than 3 precipitable micrometer (pr-micrometer) of the yearly averaged water vapor column, unless H2O is confined in a layer near the ground. Although the first possibility seems far more probable, the second hypothesis cannot be ruled out. It could reflect a continuous supply of H2O from the regolith to the atmosphere on a seasonal scale. The loss to production ratio of CO, which has a lifetime of approximately equals 5 years, is shown to depart from unity by no more than approximately equal to 10% over a wide range of atmospheric conditions. The stability of the Martian Atmosphere is therefore realized in the classical frame of homogeneous chemistry.
ERIC Educational Resources Information Center
Meyer, J. Patrick; Seaman, Michael A.
2013-01-01
The authors generated exact probability distributions for sample sizes up to 35 in each of three groups ("n" less than or equal to 105) and up to 10 in each of four groups ("n" less than or equal to 40). They compared the exact distributions to the chi-square, gamma, and beta approximations. The beta approximation was best in…
A Tidal Disruption Event in a Nearby Galaxy Hosting an Intermediate Mass Black Hole
NASA Technical Reports Server (NTRS)
Donato, D; Cenko, S. B.; Covino, S.; Troja, E.; Pursimo, T.; Cheung, C. C.; Fox, O.; Kutyrev, A.; Campana, S.; Fugazza, D.;
2014-01-01
We report the serendipitous discovery of a bright point source flare in the Abell cluster A1795 with archival EUVE and Chandra observations. Assuming the EUVE emission is associated with the Chandra source, the X-ray 0.5-7 kiloelectronvolt flux declined by a factor of approximately 2300 over a time span of 6 years, following a power-law decay with index approximately equal to 2.44 plus or minus 0.40. The Chandra data alone vary by a factor of approximately 20. The spectrum is well fit by a blackbody with a constant temperature of kiloteslas approximately equal to 0.09 kiloelectronvolts (approximately equal to 10 (sup 6) Kelvin). The flare is spatially coincident with the nuclear region of a faint, inactive galaxy with a photometric redshift consistent at the 1 sigma level with the cluster (redshift = 0.062476).We argue that these properties are indicative of a tidal disruption of a star by a black hole (BH) with log(M (sub BH) / M (sub 1 solar mass)) approximately equal to 5.5 plus or minus 0.5. If so, such a discovery indicates that tidal disruption flares may be used to probe BHs in the intermediate mass range, which are very difficult to study by other means.
Evidence that the X-Ray Plasma in Microflares is in a Sequence of Subresolution Magnetic Tubes
NASA Technical Reports Server (NTRS)
Moore, Ronald L.; Falconer, D. A.; Porter, Jason G.
1998-01-01
We analyze the cooling of the X-ray emitting thermal plasma in microflares observed in active regions by the Yohkoh Soft X-ray Telescope. A typical microflare appears to be a transient brightening of an entire small magnetic loop, often having a diameter near the limit of resolution (approximately 2 x 10(exp 8) cm) (Shimizu 1995, PASJ, 47, 251). The X-ray plasma in the loop cools by emission of XUV radiation and by heat conduction to the cooler plasma at the feet of the loop. The cooling rate is determined by the plasma temperature and density and the loop length. The plasma density is determined from the observed X-ray brightness of the loop in combination with the temperature, the loop diameter, and the filling factor. The filling factor is the volume fraction of the loop occupied by the subset of magnetic tubes that is filled by the X-ray plasma and that contains practically all of the X-ray plasma present in the microflare loop. Taking typical values from the hundreds of microflares measured by Shimizu (1995) (X-ray brightness through the thin aluminum filter approximately 4 x 10(exp 3) DN/s/pixel, lifetime approximately 5 min, temperature approximately 6 x 10(exp 6) K, loop length approximately 10(exp 9) cm, loop diameter approximately 3 x 10(exp 8) cm), we find that for filling factors greater than approximately 1% (1) the cooling time is much shorter than the duration of the microflare, and (2) conductive cooling strongly dominates over radiative cooling. Because the cooling time is so short and because the conductive heat flux goes mainly into increasing the plasma density via chromospheric evaporation, we are compelled to conclude that (1) heating to X-ray temperatures continues through nearly the entire life of a microflare, (2) the heating keeps changing to different field lines, so that any one magnetic tube in the sequence of heated tubes emits X-rays only briefly in the life of the microflare, and (3) at any instant during the microflare the tubes filled with X-ray plasma occupy only a small fraction (less than approximately 10%) of the microflare loop. Hence, we expect that coronal X-ray images with spatial resolution 2-3 times better than from Yohkoh will show plenty of rapidly changing filamentary substructure in microflares.
McIntire, Sean; Boujie, Lee
2016-01-01
Inner ear barotrauma can occur when the gas-filled chambers of the ear have difficulty equalizing pressure with the outside environment after changes in ambient pressure. This can transpire even with small pressure changes. Hypobaric or hyperbaric environments can place significant stress on the structures of the middle and inner ear. If methods to equalize pressure between the middle ear and other connected gas-filled spaces (i.e., Valsalva maneuver) are unsuccessful, middle ear overpressurization can occur. This force can be transmitted to the fluid-filled inner ear, making it susceptible to injury. Damage specifically to the structures of the vestibulocochlear system can lead to symptoms of vertigo, hearing loss, and tinnitus. This article discusses the case of a 23-year-old male Marine who presented with symptoms of nausea and gait instability after performing underwater pool competency exercises to a maximum depth of 13 feet, without breathing compressed air. Diagnosis and management of inner ear barotrauma are reviewed, as is differentiation from inner ear decompression sickness. 2016.
A negentropy minimization approach to adaptive equalization for digital communication systems.
Choi, Sooyong; Lee, Te-Won
2004-07-01
In this paper, we introduce and investigate a new adaptive equalization method based on minimizing approximate negentropy of the estimation error for a finite-length equalizer. We consider an approximate negentropy using nonpolynomial expansions of the estimation error as a new performance criterion to improve performance of a linear equalizer based on minimizing minimum mean squared error (MMSE). Negentropy includes higher order statistical information and its minimization provides improved converge, performance and accuracy compared to traditional methods such as MMSE in terms of bit error rate (BER). The proposed negentropy minimization (NEGMIN) equalizer has two kinds of solutions, the MMSE solution and the other one, depending on the ratio of the normalization parameters. The NEGMIN equalizer has best BER performance when the ratio of the normalization parameters is properly adjusted to maximize the output power(variance) of the NEGMIN equalizer. Simulation experiments show that BER performance of the NEGMIN equalizer with the other solution than the MMSE one has similar characteristics to the adaptive minimum bit error rate (AMBER) equalizer. The main advantage of the proposed equalizer is that it needs significantly fewer training symbols than the AMBER equalizer. Furthermore, the proposed equalizer is more robust to nonlinear distortions than the MMSE equalizer.
NASA Technical Reports Server (NTRS)
Harrison, F. A.; Aird, J.; Civano, F.; Lansbury, G.; Mullaney, J. R.; Ballentyne, D. R.; Alexander, D. M.; Stern, D.; Ajello, M.; Barret, D.;
2016-01-01
We present the 3-8 kiloelectronvolts and 8-24 kiloelectronvolts number counts of active galactic nuclei (AGNs) identified in the Nuclear Spectroscopic Telescope Array (NuSTAR) extragalactic surveys. NuSTAR has now resolved 33 percent -39 percent of the X-ray background in the 8-24 kiloelectronvolts band, directly identifying AGNs with obscuring columns up to approximately 10 (exp 25) per square centimeter. In the softer 3-8 kiloelectronvolts band the number counts are in general agreement with those measured by XMM-Newton and Chandra over the flux range 5 times 10 (exp -15) less than or approximately equal to S (3-8 kiloelectronvolts) divided by ergs per second per square centimeter less than or approximately equal to 10 (exp -12) probed by NuSTAR. In the hard 8-24 kiloelectronvolts band NuSTAR probes fluxes over the range 2 times 10 (exp -14) less than or approximately equal to S (8-24 kiloelectronvolts) divided by ergs per second per square centimeter less than or approximately equal to 10 (exp -12), a factor approximately 100 times fainter than previous measurements. The 8-24 kiloelectronvolts number counts match predictions from AGN population synthesis models, directly confirming the existence of a population of obscured and/or hard X-ray sources inferred from the shape of the integrated cosmic X-ray background. The measured NuSTAR counts lie significantly above simple extrapolation with a Euclidian slope to low flux of the Swift/BAT15-55 kiloelectronvolts number counts measured at higher fluxes (S (15-55 kiloelectronvolts) less than or approximately equal to 10 (exp -11) ergs per second per square centimeter), reflecting the evolution of the AGN population between the Swift/BAT local (redshift is less than 0.1) sample and NuSTAR's redshift approximately equal to 1 sample. CXB (Cosmic X-ray Background) synthesis models, which account for AGN evolution, lie above the Swift/BAT measurements, suggesting that they do not fully capture the evolution of obscured AGNs at low redshifts
NE VIII lambda 774 and time variable associated absorption in the QSO UM 675
NASA Technical Reports Server (NTRS)
Hamann, Fred; Barlow, Thomas A.; Beaver, E. A.; Burbidge, E. M.; Cohen, Ross D.; Junkkarinen, Vesa; Lyons, R.
1995-01-01
We discuss measurements of Ne VIII lambda 774 absorption and the time variability of other lines in the z(sub a) approximately equal z(sub e) absorption system of the z(sub e) = 2.15 QSO UM 675 (0150-203). The C IV lambda 1549 and N V 1240 doublets at z(sub a) = 2.1340 (shifted approximately 1500 km/s from z(sub e) strengthened by a factor of approximately 3 between observations by Sargent, Boksenberg and Steidel (1981 November) and our earliest measurements (1990 November and December). We have no information on changes in other z(sub a) approximately equal z(sub e) absorption lines. Continued monitoring since 1990 November shows no clear changes in any of the absorptions between approximately 1100 and 1640 A rest. The short timescale of the variability (less than or approximately equal to 2.9 yr rest) strongly suggests that the clouds are dense, compact, close to the QSO, and photoionized by the QSO continuum. If the line variability is caused by changes in the ionization, the timescale requires densities greater than approximately 4000/cu cm. Photoionization calculations place the absorbing clouds within approximately 200 pc of the continuum source. The full range of line ionizations (from Ne VIII lambda 774 to C III lambda 977) in optically thin gas (no Lyman limit) implies that the absorbing regions span a factor of more than approximately 10 in distance or approximately 100 in density. Across these regions, the total hydrogen (H I + H II) column ranges from a few times 10(exp 18)/sq cm in the low-ionization gas to approximately 10(exp 20)/sq cm where the Ne VIII doublet forms. The metallicity is roughly solar or higher, with nitrogen possibly more enhanced by factors of a few. The clouds might contribute significant line emission if they nearly envelop the QSO. The presence of highly ionized Ne VIII lambda 774 absorption near the QSO supports recent studies that link z(sub a) approximately equal to z(sub e) systems with X-ray 'wamr absorbers. We show that the Ne VIII absorbing gas would itself produce measurable warm absorption -- characterized by bound-free O VII or O VIII edegs near 0.8 keV -- if the column densities were N(sub H) greater than or approximately equal to 10(exp 21)/sq cm (for solar abundances).
NE VIII lambda 774 and time variable associated absorption in the QSO UM 675
NASA Astrophysics Data System (ADS)
Hamann, Fred; Barlow, Thomas A.; Beaver, E. A.; Burbidge, E. M.; Cohen, Ross D.; Junkkarinen, Vesa; Lyons, R.
1995-04-01
We discuss measurements of Ne VIII lambda 774 absorption and the time variability of other lines in the za approximately equal ze absorption system of the ze = 2.15 QSO UM 675 (0150-203). The C IV lambda 1549 and N V 1240 doublets at za = 2.1340 (shifted approximately 1500 km/s from ze strengthened by a factor of approximately 3 between observations by Sargent, Boksenberg and Steidel (1981 November) and our earliest measurements (1990 November and December). We have no information on changes in other za approximately equal ze absorption lines. Continued monitoring since 1990 November shows no clear changes in any of the absorptions between approximately 1100 and 1640 A rest. The short timescale of the variability (less than or approximately equal to 2.9 yr rest) strongly suggests that the clouds are dense, compact, close to the QSO, and photoionized by the QSO continuum. If the line variability is caused by changes in the ionization, the timescale requires densities greater than approximately 4000/cu cm. Photoionization calculations place the absorbing clouds within approximately 200 pc of the continuum source. The full range of line ionizations (from Ne VIII lambda 774 to C III lambda 977) in optically thin gas (no Lyman limit) implies that the absorbing regions span a factor of more than approximately 10 in distance or approximately 100 in density. Across these regions, the total hydrogen (H I + H II) column ranges from a few times 1018/sq cm in the low-ionization gas to approximately 1020/sq cm where the Ne VIII doublet forms. The metallicity is roughly solar or higher, with nitrogen possibly more enhanced by factors of a few. The clouds might contribute significant line emission if they nearly envelop the QSO. The presence of highly ionized Ne VIII lambda 774 absorption near the QSO supports recent studies that link za approximately equal to ze systems with X-ray 'wamr absorbers. We show that the Ne VIII absorbing gas would itself produce measurable warm absorption -- characterized by bound-free O VII or O VIII edegs near 0.8 keV -- if the column densities were NH greater than or approximately equal to 1021/sq cm (for solar abundances).
Impact of conditions at start-up on thermovibrational convective flow.
Melnikov, D E; Shevtsova, V M; Legros, J C
2008-11-01
The development of thermovibrational convection in a cubic cell filled with high Prandtl number liquid (isopropanol) is studied. Direct nonlinear simulations are performed by solving three-dimensional Navier-Stokes equations in the Boussinesq approximation. The cell is subjected to high frequency periodic oscillations perpendicular to the applied temperature gradient under zero gravity. Two types of vibrations are imposed: either as a sine or cosine function of time. It is shown that the initial vibrational phase plays a significant role in the transient behavior of thermovibrational convective flow. Such knowledge is important to interpret correctly short-duration experimental results performed in microgravity, among which the most accessible are drop towers ( approximately 5s) and parabolic flights ( approximately 20s) . It is obtained that under sine vibrations, the flow reaches steady state within less than one thermal time. Under cosine acceleration, this time is 2 times longer. For cosine excitations, the Nusselt number is approximately 10 times smaller in comparison with the sine case. Besides, in the case of cosine, the Nusselt number oscillates with double frequency. However, at the steady state, time-averaged and oscillatory characteristics of the flow are independent of the vibrational start-up. The only feature that always differs the two cases is the phase difference between the velocity, temperature, and accelerations. We have found that due to nonlinear response of the system to the imposed vibrations, the phase shift between velocity and temperature is never equal exactly to pi2 , at least in weightlessness. Thus, heat transport always exists from the beginning of vibrations, although it might be weak.
Quantitative near-infrared spectroscopy on patients with peripheral vascular disease
NASA Astrophysics Data System (ADS)
Franceschini, Maria-Angela; Fantini, Sergio; Palumbo, Renato; Pasqualini, Leonella; Vaudo, Gaetano; Franceschini, Edoardo; Gratton, Enrico; Palumbo, Barbara; Innocente, Salvatore; Mannarino, Elmo
1998-01-01
We have used near-infrared spectroscopy to measure the hemoglobin saturation at rest and during exercise on patients affected by peripheral vascular disease (PVD). The instrument used in our study is a frequency-domain tissue oximeter which employs intensity modulated (110 MHz) laser diodes. We examined 9 subjects, 3 of which were controls and 6 were patients affected by stage II PVD. The optical probe was located on the calf muscle of the subjects. The measurement protocol consisted of: (1) baseline (approximately 5 min); (2) stationary bicycle exercise (approximately 5 min); (3) recovery (approximately 15 min). The change in hemoglobin saturation during exercise ((Delta) Y) and the recovery time after exercise (trec) were significantly greater in the PVD patients ((Delta) Y equals -21 +/- 3%, trec equals 5.9 +/- 3.8 min) than in the control subjects ((Delta) Y equals 2 +/- 3%, trec equals 0.6 +/- 0.1 min).
Predicting the Redshift 2 H-Alpha Luminosity Function Using [OIII] Emission Line Galaxies
NASA Technical Reports Server (NTRS)
Mehta, Vihang; Scarlata, Claudia; Colbert, James W.; Dai, Y. S.; Dressler, Alan; Henry, Alaina; Malkan, Matt; Rafelski, Marc; Siana, Brian; Teplitz, Harry I.;
2015-01-01
Upcoming space-based surveys such as Euclid and WFIRST-AFTA plan to measure Baryonic Acoustic Oscillations (BAOs) in order to study dark energy. These surveys will use IR slitless grism spectroscopy to measure redshifts of a large number of galaxies over a significant redshift range. In this paper, we use the WFC3 Infrared Spectroscopic Parallel Survey (WISP) to estimate the expected number of H-alpha emitters observable by these future surveys. WISP is an ongoing Hubble Space Telescope slitless spectroscopic survey, covering the 0.8 - 1.65 micrometers wavelength range and allowing the detection of H-alpha emitters up to z approximately equal to 1.5 and [OIII] emitters to z approximately equal to 2.3. We derive the H-alpha-[OIII] bivariate line luminosity function for WISP galaxies at z approximately equal to 1 using a maximum likelihood estimator that properly accounts for uncertainties in line luminosity measurement, and demonstrate how it can be used to derive the H-alpha luminosity function from exclusively fitting [OIII] data. Using the z approximately equal to 2 [OIII] line luminosity function, and assuming that the relation between H-alpha and [OIII] luminosity does not change significantly over the redshift range, we predict the H-alpha number counts at z approximately equal to 2 - the upper end of the redshift range of interest for the future surveys. For the redshift range 0.7 less than z less than 2, we expect approximately 3000 galaxies per sq deg for a flux limit of 3 x 10(exp -16) ergs per sec per sq cm (the proposed depth of Euclid galaxy redshift survey) and approximately 20,000 galaxies per sq deg for a flux limit of approximately 10(exp -16) ergs per sec per sq cm (the baseline depth of WFIRST galaxy redshift survey).
7 CFR 52.3753 - Styles of canned ripe olives.
Code of Federal Regulations, 2010 CFR
2010-01-01
...) Halved. “Halved” olives are pitted olives in which each olive is cut lengthwise into two approximately equal parts. (d) Segmented. “Segmented” olives are pitted olives in which each olive is cut lengthwise into three or more approximately equal parts. (e) Sliced. “Sliced” olives consist of parallel slices of...
7 CFR 52.3753 - Styles of canned ripe olives.
Code of Federal Regulations, 2011 CFR
2011-01-01
...) Halved. “Halved” olives are pitted olives in which each olive is cut lengthwise into two approximately equal parts. (d) Segmented. “Segmented” olives are pitted olives in which each olive is cut lengthwise into three or more approximately equal parts. (e) Sliced. “Sliced” olives consist of parallel slices of...
Edelstein, P H; Pasiecznik, K A; Yasui, V K; Meyer, R D
1982-01-01
Thirty-three strains of Legionella spp., 29 of which were L. pneumophila, were tested for their susceptibilities to erythromycin (EM), rosaramicin, tylosin, mycinamicin I (Sch-27897), and mycinamicin II (Sch-27896). Testing was performed using an agar dilution method with two different types of media: buffered charcoal yeast extract medium supplemented with 0.1% alpha-ketoglutarate (BCYE alpha) and filter-sterilized yeast extract medium with 0.1% alpha-ketoglutarate (BYE alpha). The minimal inhibitory concentrations (MICs) of the drugs tested relative to the MICs of erythromycin were: rosaramicin, MIC approximately equal to 0.2 EM MIC; tylosin, MIC approximately equal to 2 EM MIC; mycinamicin I, MIC approximately equal to 0.5 EM MIC; and mycinamicin II, MIC approximately equal to EM MIC. Both types of media caused equivalent partial inactivation of the macrolides which was apparently due entirely to pH effect. MICs on BCYE alpha were one to five times more than those observed on BYE alpha; this may be due to poorer growth on BYE alpha. PMID:7125633
A Sequence of Outbursts from the Transient X-Ray Pulsar GS 0834-430
NASA Technical Reports Server (NTRS)
Wilson, Colleen A.; Finger, Mark H.; Harmon, B.Alan; Scott, D. Matthew; Wilson, Robert B.; Bildsten, Lars; Chakrabarty, Deepto; Prince, Thomas A.
1997-01-01
GS 0834-430, a 12.3 s accretion-powered pulsar, has been observed in seven outbursts with the BATSE large-area detectors on the Compton Gamma Ray Observatory. The first five outbursts observed by BATSE occurred at intervals of about 107 days, while the final two outbursts were separated by about 140 days. The photon energy spectrum, measured by Earth occultation in the 20 100 keV band, can be fitted by a power law with photon index alpha approximately equals -3.7 or by an exponential spectrum with temperature kT approximately equals 15 keV, with some variations within outbursts. The source has a low pulse fraction, less than or equal to 0.15 in the 20-50 keV band. We have observed significant temporal and energy-dependent variations in epoch folded pulse profiles. Because the intrinsic torque effects for this system are at least comparable to orbital effects, pulse timing analysis did not produce a unique orbital solution. However, confidence regions for the orbital elements yielded the following 1 sigma limits: orbital period P(sub orb) = 105.8 +/- 0.4 days and eccentricity 0.10 less than or approximately equals epsilon less than or approximately equals 0.17. GS 0834-430 is most likely a Be/X-ray binary.
The effectiveness of Hong Kong's Construction Waste Disposal Charging Scheme.
Hao, Jane L; Hills, Martin J; Tam, Vivian W Y
2008-12-01
The Hong Kong Government introduced the Construction Waste Disposal Charging Scheme in December 2005 to ensure that disposal of construction and demolition (C&D) waste is properly priced to reduce such waste. The charging scheme is not only intended to provide an economic incentive for contractors and developers to reduce waste but also to encourage reuse and recycling of waste material thereby slowing down the depletion of limited landfill and public filling capacities. This paper examines the effectiveness of the charging scheme 1 year after implementation. A survey was conducted at Tseung Kwan O Area 137 and Tuen Mun Area 38, and daily C&D waste records were collected from landfills and public filling facilities between January 2006 and December 2006. The results of the survey show that waste has been reduced by approximately 60% in landfills, by approximately 23% in public fills, and by approximately 65% in total waste between 2005 and 2006. Suggestions for improving the scheme are provided.
Study of Uneven Fills to Cure the Coupled-Bunch Instability in SRRC
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chao, Alex W.
2002-08-12
The performance of the 1.5-GeV storage ring light source TLS in SRRC has been limited by a longitudinal coupled-bunch beam instability. To improve the performance of the TLS, the beam instability has to be suppressed. One possible way considered for the TLS to suppress its coupled-bunch instability uses uneven filling patterns according to the theory of Prabhakar[1]. By knowing the harmful high-order-modes (HOMs), a special filling pattern can be designed to utilize either mode coupling or Landau damping to cure beam instability. In TLS the HOMs are contributed from the Doris RF cavity installed in the storage ring. The HOMsmore » of a 3-D Doris cavity was numerically analyzed. Filling patterns with equal bunch current according to theory had been calculated to cure the most harmful HOM. A longitudinal particle tracking program was used to simulate the coupled-bunch beam instability with both the uniform filling and the special designed filling. Filling pattern with unequal bunch current was also studied. The results of the simulation were discussed and compared to the theory.« less
Equal Plate Charges on Series Capacitors?
ERIC Educational Resources Information Center
Illman, B. L.; Carlson, G. T.
1994-01-01
Provides a line of reasoning in support of the contention that the equal charge proposition is at best an approximation. Shows how the assumption of equal plate charge on capacitors in series contradicts the conservative nature of the electric field. (ZWH)
An evaluation of a manganese bath system having a new geometry through MCNP modelling.
Khabaz, Rahim
2012-12-01
In this study, an approximate symmetric cylindrical manganese bath system with equal diameter and height was appraised using a Monte Carlo simulation. For nine sizes of the tank filled with MnSO(4).H(2)O solution of three different concentrations, the necessary correction factors involved in the absolute measurement of neutron emission rate were determined by a detailed modelling of the MCNP4C code with the ENDF/B-VII.0 neutron cross section data library. The results obtained were also used to determine the optimum dimensions of the bath for each concentration of solution in the calibration of (241)Am-Be and (252)Cf sources. Also, the amount of gamma radiation produced as a result of (n,γ) the reaction with the nuclei of the manganese sulphate solution that escaped from the boundary of each tank was evaluated. This gamma can be important for the background in NaI(Tl) detectors and issues concerned with radiation protection.
Schmutz, Bryan P; Santerre, Rexford E
2013-02-01
Unlike the pharmaceutical industry, no empirical research has focused on the factors influencing research and development (R&D) spending in the medical device industry. To fill that gap, this study examines how R&D spending is influenced by prior year cash flow and corporate market value using multiple regression analysis and a panel data set of medical device companies over the period 1962-2008. The empirical findings suggest that the elasticities of R&D spending with respect to cash flow and corporate market value equal 0.58 and 0.31, respectively. Moreover, based upon these estimates, simulations show that the recently enacted excise tax on medical devices, taken alone, will reduce R&D spending by approximately $4 billion and thereby lead to a minimum loss of $20 billion worth of human life years over the first 10 years of its enactment. Copyright © 2012 John Wiley & Sons, Ltd.
Space charge in nanostructure resonances
NASA Astrophysics Data System (ADS)
Price, Peter J.
1996-10-01
In quantum ballistic propagation of electrons through a variety of nanostructures, resonance in the energy-dependent transmission and reflection probabilities generically is associated with (1) a quasi-level with a decay lifetime, and (2) a bulge in electron density within the structure. It can be shown that, to a good approximation, a simple formula in all cases connects the density of states for the latter to the energy dependence of the phase angles of the eigen values of the S-matrix governing the propagation. For both the Lorentzian resonances (normal or inverted) and for the Fano-type resonances, as a consequence of this eigen value formula, the space charge due to filled states over the energy range of a resonance is just equal (for each spin state) to one electron charge. The Coulomb interaction within this space charge is known to 'distort' the electrical characteristics of resonant nanostructures. In these systems, however, the exchange effect should effectively cancel the interaction between states with parallel spins, leaving only the anti-parallel spin contribution.
NASA Technical Reports Server (NTRS)
Alexander, D. M.; Stern, D.; DelMoro, A.; Lansbury, G. B.; Assef, R. J.; Aird, J.; Ajello, M.; Ballantyne, D. R.; Bauer, F. E.; Boggs, S. E.;
2013-01-01
We report on the first 10 identifications of sources serendipitously detected by the Nuclear Spectroscopic Telescope Array (NuSTAR) to provide the first sensitive census of the cosmic X-ray background source population at approximately greater than 10 keV. We find that these NuSTAR-detected sources are approximately 100 times fainter than those previously detected at approximately greater than 10 keV and have a broad range in redshift and luminosity (z = 0.020-2.923 and L(sub 10-40 keV) approximately equals 4 × 10(exp 41) - 5 × 10(exp 45) erg per second; the median redshift and luminosity are z approximately equal to 0.7 and L(sub 10-40 keV) approximately equal to 3 × 10(exp 44) erg per second, respectively. We characterize these sources on the basis of broad-band approximately equal to 0.5 - 32 keV spectroscopy, optical spectroscopy, and broad-band ultraviolet-to-mid-infrared spectral energy distribution analyses. We find that the dominant source population is quasars with L(sub 10-40 keV) greater than 10(exp 44) erg per second, of which approximately 50% are obscured with N(sub H) approximately greater than 10(exp 22) per square centimeters. However, none of the 10 NuSTAR sources are Compton thick (N(sub H) approximately greater than 10(exp 24) per square centimeters) and we place a 90% confidence upper limit on the fraction of Compton-thick quasars (L(sub 10-40 keV) greater than 10(exp 44) erg per second) selected at approximately greater than 10 keV of approximately less than 33% over the redshift range z = 0.5 - 1.1. We jointly fitted the rest-frame approximately equal to 10-40 keV data for all of the non-beamed sources with L(sub 10-40 keV) greater than 10(exp 43) erg per second to constrain the average strength of reflection; we find R less than 1.4 for gamma = 1.8, broadly consistent with that found for local active galactic nuclei (AGNs) observed at approximately greater than 10 keV. We also constrain the host-galaxy masses and find a median stellar mass of approximately 10(exp 11) solar mass, a factor approximately 5 times higher than the median stellar mass of nearby high-energy selected AGNs, which may be at least partially driven by the order of magnitude higher X-ray luminosities of the NuSTAR sources. Within the low source-statistic limitations of our study, our results suggest that the overall properties of the NuSTAR sources are broadly similar to those of nearby high-energy selected AGNs but scaled up in luminosity and mass.
Studying Star and Planet Formation with the Submillimeter Probe of the Evolution of Cosmic Structure
NASA Technical Reports Server (NTRS)
Rinehart, Stephen A.
2005-01-01
The Submillimeter Probe of the Evolution of Cosmic Structure (SPECS) is a far- infrared/submillimeter (40-640 micrometers) spaceborne interferometry concept, studied through the NASA Vision Missions program. SPECS is envisioned as a 1-km baseline Michelson interferometer with two 4- meter collecting mirrors. To maximize science return, SPECS will have three operational modes: a photometric imaging mode, an intermediate spectral resolution mode (R approximately equal to 1000-3000), and a high spectral resolution mode (R approximately equal to 3 x 10(exp 5)). The first two of these modes will provide information on all sources within a 1 arcminute field-of-view (FOV), while the the third will include sources in a small (approximately equal to 5 arcsec) FOV. With this design, SPECS will have angular resolution comparable to the Hubble Space Telescope (50 mas) and sensitivity more than two orders of magnitude better than Spitzer (5sigma in 10ks of approximately equal to 3 x 10(exp 7) Jy Hz). We present here some of the results of the recently-completed Vision Mission Study for SPECS, and discuss the application of this mission to future studies of star and planet formation.
Status of lithium-filled specimen subcapsules for the HFIR-MFE-RB10J experiment
DOE Office of Scientific and Technical Information (OSTI.GOV)
Robertson, J.P.; Howell, M.; Lenox, K.E.
1998-09-01
The HFIR-MFE-RB-10J experiment will be irradiated in a Removable Beryllium position in the HFIR for 10 reactor cycles, accumulating approximately 5 dpa in steel. The upper region of the capsule contains two lithium-filled subcapsules containing vanadium specimens. This report describes the techniques developed to achieve a satisfactory lithium fill with a specimen occupancy of 26% in each subcapsule.
A spectrum of the veiled T Tauri star CY Tau
NASA Technical Reports Server (NTRS)
Stuewe, J. A.; Schultz, R.
1994-01-01
We present a flux calibrated spectrum of the star listed as CY Tau in the `General Catalog of Variable Stars 4th ed.' in the spectral range 3700 A less than or equal to lambda less than or equal to 6400 A with a resolution of approximately equals 15 A showing the Balmer-Series from H(sub beta) to H(sub 10) as well as the CaII H (in blend with H(sub epsilon) and K lines in emission. Apart from the emission lines the spectrum is composed of a continuum equivalent to that of an ordinary pre-main sequence star (i.e. a `naked' T Tau) of spectral type M2 V with emission lines plus a `blue' veiling continuum that can be described as black body radiation of temperature T(sub BL) approximately equals 7000K due to accretion onto a boundary layer at a rate of M-dot(sub acc) greater than or approximately = 2.18 10(exp -8) solar mass/a.
Behavior of rigid and flexible culvert pipes under deep fill.
DOT National Transportation Integrated Search
1977-01-01
Along a section of Interstate 77 in Carroll County, in the mountainous region of southwestern Virginia, it was necessary to construct a fill approximately 258 ft (78 m) deep. The flow of a mountain stream had to be carried through this massive embank...
Fluid Dynamics of Bottle Filling
NASA Astrophysics Data System (ADS)
McGough, Patrick; Gao, Haijing; Appathurai, Santosh; Basaran, Osman
2011-11-01
Filling of bottles is a widely practiced operation in a large number of industries. Well known examples include filling of ``large'' bottles with shampoos and cleaners in the household products and beauty care industries and filling of ``small'' bottles in the pharmaceutical industry. Some bottle filling operations have recently drawn much attention from the fluid mechanics community because of the occurrence of a multitude of complex flow regimes, transitions, and instabilities such as mounding and coiling that occur as a bottle is filled with a fluid. In this talk, we present a primarily computational study of the fluid dynamical challenges that can arise during the rapid filling of bottles. Given the diversity of fluids used in filling applications, we consider four representative classes of fluids that exhibit Newtonian, shear-thinning, viscoelastic, and yield-stress rheologies. The equations governing the dynamics of bottle filling are solved either in their full 3D but axisymmetric form or using the slender-jet approximation.
Quantified Energy Dissipation Rates in the Terrestrial Bow Shock. 2; Waves and Dissipation
NASA Technical Reports Server (NTRS)
Wilson, L. B., III; Sibeck, D. G.; Breneman, A. W.; Le Contel, O.; Cully, C.; Turner, D. L.; Angelopoulos, V.; Malaspina, D. M.
2014-01-01
We present the first quantified measure of the energy dissipation rates, due to wave-particle interactions, in the transition region of the Earth's collision-less bow shock using data from the Time History of Events and Macro-Scale Interactions during Sub-Storms spacecraft. Our results show that wave-particle interactions can regulate the global structure and dominate the energy dissipation of collision-less shocks. In every bow shock crossing examined, we observed both low-frequency (less than 10 hertz) and high-frequency (approximately or greater than10 hertz) electromagnetic waves throughout the entire transition region and into the magnetosheath. The low-frequency waves were consistent with magnetosonic-whistler waves. The high-frequency waves were combinations of ion-acoustic waves, electron cyclotron drift instability driven waves, electrostatic solitary waves, and whistler mode waves. The high-frequency waves had the following: (1) peak amplitudes exceeding delta B approximately equal to 10 nanoteslas and delta E approximately equal to 300 millivolts per meter, though more typical values were delta B approximately equal to 0.1-1.0 nanoteslas and delta E approximately equal to 10-50 millivolts per meter (2) Poynting fluxes in excess of 2000 microWm(sup -2) (micro-waves per square meter) (typical values were approximately 1-10 microWm(sup -2) (micro-waves per square meter); (3) resistivities greater than 9000 omega meters; and (4) associated energy dissipation rates greater than 10 microWm(sup -3) (micro-waves per cubic meter). The dissipation rates due to wave-particle interactions exceeded rates necessary to explain the increase in entropy across the shock ramps for approximately 90 percent of the wave burst durations. For approximately 22 percent of these times, the wave-particle interactions needed to only be less than or equal to 0.1 percent efficient to balance the nonlinear wave steepening that produced the shock waves. These results show that wave-particle interactions have the capacity to regulate the global structure and dominate the energy dissipation of collision-less shocks.
High-resolution observations of the polar magnetic fields of the sun
NASA Technical Reports Server (NTRS)
Lin, H.; Varsik, J.; Zirin, H.
1994-01-01
High-resolution magnetograms of the solar polar region were used for the study of the polar magnetic field. In contrast to low-resolution magnetograph observations which measure the polar magnetic field averaged over a large area, we focused our efforts on the properties of the small magnetic elements in the polar region. Evolution of the filling factor (the ratio of the area occupied by the magnetic elements to the total area) of these magnetic elements, as well as the average magnetic field strength, were studied during the maximum and declining phase of solar cycle 22, from early 1991 to mid-1993. We found that during the sunspot maximum period, the polar regions were occupied by about equal numbers of positive and negative magnetic elements, with equal average field strength. As the solar cycle progresses toward sunspot minimum, the magnetic field elements in the polar region become predominantly of one polarity. The average magnetic field of the dominant polarity elements also increases with the filling factor. In the meanwhile, both the filling factor and the average field strength of the non-dominant polarity elements decrease. The combined effects of the changing filling factors and average field strength produce the observed evolution of the integrated polar flux over the solar cycle. We compared the evolutionary histories of both filling factor and average field strength, for regions of high (70-80 deg) and low (60-70 deg) latitudes. For the south pole, we found no significant evidence of difference in the time of reversal. However, the low-latitude region of the north pole did reverse polarity much earlier than the high-latitude region. It later showed an oscillatory behavior. We suggest this may be caused by the poleward migration of flux from a large active region in 1989 with highly imbalanced flux.
NASA Technical Reports Server (NTRS)
Gofford, Jason; Reeves, James N.; Tombesi, Francesco; Braito, Valentina; Turner, T. Jane; Miller, Lance; Cappi, Massimo
2013-01-01
We present the results of a new spectroscopic study of Fe K-band absorption in active galactic nuclei (AGN). Using data obtained from the Suzaku public archive we have performed a statistically driven blind search for Fe XXV Healpha and/or Fe XXVI Lyalpha absorption lines in a large sample of 51 Type 1.0-1.9 AGN. Through extensive Monte Carlo simulations we find that statistically significant absorption is detected at E greater than or approximately equal to 6.7 keV in 20/51 sources at the P(sub MC) greater than or equal tov 95 per cent level, which corresponds to approximately 40 per cent of the total sample. In all cases, individual absorption lines are detected independently and simultaneously amongst the two (or three) available X-ray imaging spectrometer detectors, which confirms the robustness of the line detections. The most frequently observed outflow phenomenology consists of two discrete absorption troughs corresponding to Fe XXV Healpha and Fe XXVI Lyalpha at a common velocity shift. From xstar fitting the mean column density and ionization parameter for the Fe K absorption components are log (N(sub H) per square centimeter)) is approximately equal to 23 and log (Xi/erg centimeter per second) is approximately equal to 4.5, respectively. Measured outflow velocities span a continuous range from less than1500 kilometers per second up to approximately100 000 kilometers per second, with mean and median values of approximately 0.1 c and approximately 0.056 c, respectively. The results of this work are consistent with those recently obtained using XMM-Newton and independently provides strong evidence for the existence of very highly ionized circumnuclear material in a significant fraction of both radio-quiet and radio-loud AGN in the local universe.
NASA Astrophysics Data System (ADS)
Amami, Sadek; Ozer, Zehra N.; Dogan, Mevlut; Yavuz, Murat; Varol, Onur; Madison, Don
2016-09-01
There have been several studies of electron-impact ionization of inert gases for asymmetric final state energy sharing and normally one electron has an energy significantly higher than the other. However, there have been relatively few studies examining equal energy final state electrons. Here we report experimental and theoretical triple differential cross sections for electron impact ionization of Ar (3p) for equal energy sharing of the outgoing electrons. Previous experimental results combined with some new measurements are compared with distorted wave born approximation (DWBA) results, DWBA results using the Ward-Macek (WM) approximation for the post collision interaction (PCI), and three-body distorted wave (3DW) which includes PCI without approximation. The results show that it is crucially important to include PCI in the calculation particularly for lower energies and that the WM approximation is valid only for high energies. The 3DW, on the other hand, is in reasonably good agreement with data down to fairly low energies.
Deep HST imaging of distant weak radio and field galaxies
NASA Technical Reports Server (NTRS)
Windhorst, R. A.; Gordon, J. M.; Pascarelle, S. M.; Schmidtke, P. C.; Keel, W. C.; Burkey, J. M.; Dunlop, J. S.
1994-01-01
We present deep Hubble Space Telescope (HST) Wide-Field Camera (WFC) V- and I-band images of three distant weak radio galaxies with z = 0.311-2.390 and seven field galaxies with z = 0.131-0.58. The images were deconvolved with both the Lucy and multiresolution CLEAN methods, which yield a restoring Full Width at Half Maximum (FWHM) of less than or equal to 0.2 sec, (nearly) preserve photons and signal-to-noise ratio at low spatial frequencies, and produce consistent light profiles down to our 2 sigma surface brightness sensitivity limit of V approximately 27.2 and I approximately 25.9 mag/sq arcsec. Multi-component image modeling was used to provide deconvolution-independent estimates of structural parameters for symmetric galaxies. We present 12-band (m(sub 2750) UBVRIgriJHK) photometry for a subset of the galaxies and bootstrap the unknown FOC/48 zero point at 2750 A in three independent ways (yielding m(sub 2750) = 21.34 +/- 0.09 mag for 1.0 e(-)/s). Two radio galaxies with z = 0.311 and 0.528, as well as one field galaxy with z = 0.58, have the colors and spectra of early-type galaxies, and a(exp 1/4)-like light profiles in the HST images. The two at z greater than 0.5 have little or no color gradients in V - I and are likely giant ellipticals, while the z = 0.311 radio galaxy has a dim exponential disk and is likely an S0. Six of the seven field galaxies have light profiles that indicate (small) inner bulges following a(exp 1/4) laws and outer exponential disks, both with little or no color gradients. These are (early-type) spiral galaxies with z = 0.131-0.528. About half have faint companions or bars. One shows lumpy structure, possibly a merger. The compact narrow-line galaxy 53W002 at z = 2.390 has less than or = 30% +/- 10% of its HST V and I flux in the central kiloparsec (due to its weak Active Galactic Nucleus (AGN)). Most of its light (V approximately equal to 23.3) occurs in a symmetric envelope with a regular a(exp 1/4)-like profile of effective radius a approximately equal to 1.1 sec (approximately equal to 12 kpc for H(sub 0) = 50, q(sub 0) = 0.1. Its (HST) V - I color varies at most from approximately 0.3 mag at a approximately equal to 0.2 sec to approximately 1.2 mag at a approximately greater than 0.4 sec, and possibly to approximately greater than 2.2 mag at a approximately greater than 1.2 sec. Together with its I - K color (approximately equal to 2.5 mag for a approximately greater than 1.0 sec-2.0 sec), this is consistent with an aging stellar population approximately 0.3-0.5 Gyr old in the galaxy center (a approx. less than 2 kpc radius), and possibly approximately 0.5-1.0 Gyr old at a approximately greater than 10 kpc radius. While its outer part may thus have started to collapse at z = 2.5-4, its inner part still is aligned with its redshifted Ly(alpha) cloud and its radio axis, possibly caused by star formation associated with the radio jet, or by reflection from its AGN cone.
NASA Astrophysics Data System (ADS)
Nurfaidhi Rizalman, Ahmad; Tahir, Ng Seong Yap Mahmood Md; Mohammad, Shahrin
2018-03-01
Concrete filled hollow steel section column have been widely accepted by structural engineers and designers for high rise construction due to the benefits of combining steel and concrete. The advantages of concrete filled hollow steel section column include higher strength, ductility, energy absorption capacity, and good structural fire resistance. In this paper, comparison on the fire performance between circular and square concrete filled hollow steel section column is established. A three-dimensional finite element package, ABAQUS, was used to develop the numerical model to study the temperature development, critical temperature, and fire resistance time of the selected composite columns. Based on the analysis and comparison of typical parameters, the effect of equal cross-sectional size for both steel and concrete, concrete types, and thickness of external protection on temperature distribution and structural fire behaviour of the columns are discussed. The result showed that concrete filled hollow steel section column with circular cross-section generally has higher fire resistance than the square section.
Arakelian 564: An XMM-Newton View
NASA Technical Reports Server (NTRS)
Vignali, Cristian; Brandt, W. N.; Boller, Th.; Fabian, A. C.; Vaughan, Simon
2003-01-01
We report on two XMM-Newton observations of the bright narrow-line Seyfert 1 galaxy Ark 564 taken one year apart (2000 June and 2001 June). The 0.6-10 keV continuum is well described by a soft blackbody component (kTau approximately equal 140-150 eV) plus a steep power law (Tau approximately equal to 2.50-2.55). No significant spectral changes are observed between the two observations, although the X-ray flux in the second observation is approximately equal to 40-50 per cent lower. In both observations we detect a significant absorption edge at a rest-frame energy of approximately equal to 0.73 keV, corresponding to O VII. The presence of the absorption feature is confirmed by a simultaneous Chandra grating observation in 2000 June, although the best-fitting edge threshold is at a slightly lower energy in the Chandra data, possibly because of a different parameterization of the underlying X-ray continuum. We find tentative evidence for a broad iron emission line in the 2000 June observation. The results from an analysis of the power spectral density (PSD) function are also presented. The present XMM-Newton data support the idea that the PSD shown two breads, although the location of the high-frequency break requires further constraints.
General analysis of slab lasers using geometrical optics.
Chung, Te-yuan; Bass, Michael
2007-02-01
A thorough and general geometrical optics analysis of a slab-shaped laser gain medium is presented. The length and thickness ratio is critical if one is to achieve the maximum utilization of absorbed pump power by the laser light in such a medium; e.g., the fill factor inside the slab is to be maximized. We point out that the conditions for a fill factor equal to 1, laser light entering and exiting parallel to the length of the slab, and Brewster angle incidence on the entrance and exit faces cannot all be satisfied at the same time. Deformed slabs are also studied. Deformation along the width direction of the largest surfaces is shown to significantly reduce the fill factor that is possible.
NASA Astrophysics Data System (ADS)
Weiss, Robert M.; Otoadese, Eramosele A.; Oren, Ron M.
1995-05-01
The syndrome of constrictive pericarditis (CP) presents a diagnostic challenge to the clinician. This study was undertaken to determine whether cine computed tomography (CT), a cardiac imaging technique with excellent temporal and spatial resolution, can reliably demonstrate the unique abnormalities of pericardial anatomy and ventricular physiology present in patients with this condition. A second goal of this study was to determine whether the presence of diseased thickened pericardium, by itself, imparts cardiac impairment due to abnormalities of ventricular diastolic function. Methods: Twelve patients with CP suspected clinically, in whom invasive hemodynamic study was consistent with the diagnosis of CP, underwent cine CT. They were subdivided into Group 1 (CP, N equals 5) and Group 2 (No CP, N equals 7) based on histopathologic evaluation of tissue obtained at the time of surgery or autopsy. A third group consisted of asymptomatic patients with incidentally discovered thickened pericardium at the time of cine CT scanning: Group 3 (ThP, N equals 7). Group 4 (Nl, N equals 7) consisted of healthy volunteer subjects. Results: Pericardial thickness measurements with cine CT clearly distinguished Group 1 (mean equals 10 +/- 2 mm) from Group 2 (mean equals 2 +/- 1 mm), with diagnostic accuracy of 100% compared to histopathological findings. In addition, patients in Group 1 had significantly more brisk early diastolic filling of both left and right ventricles than those in Group 2, which clearly distinguished all patients with, from all patients without CP. Patients in Group 3 had pericardial thicknesses similar to those in Group 1 (mean equals 9 +/- 1 mm, p equals NS), but had patterns of diastolic ventricular filling that were nearly identical to Group 4 (Nl). Conclusions: The abnormalities of anatomy and ventricular function present in the syndrome of constrictive pericarditis are clearly and decisively identified by cine CT. This allows a reliable distinction between patients with constrictive pericarditis and those with cardiomyopathy. The presence of diseased thickened pericardium does not by itself impart impairment of ventricular diastolic function. Thus, definitive diagnosis of constrictive pericarditis requires demonstration of both abnormal anatomy and physiology.
Time management for preclinical safety professionals.
Wells, Monique Y
2010-08-01
A survey about time management in the workplace was distributed to obtain a sense of the level of job satisfaction among preclinical safety professionals in the current economic climate, and to encourage reflection upon how we manage time in our work environment. Roughly equal numbers of respondents (approximately 32%) identified themselves as management or staff, and approximately 27% indicated that they are consultants. Though 45.2% of respondents indicated that time management is very challenging for the profession in general, only 36.7% find it very challenging for themselves. Ten percent of respondents view time management to be exceedingly challenging for themselves. Approximately 34% of respondents indicated that prioritization of tasks was the most challenging aspect of time management for them. Focusing on an individual task was the second most challenging aspect (26%), followed equally by procrastination and delegation of tasks (12.4%). Almost equal numbers of respondents said that they would (35.2%) or might (33.3%) undertake training to improve their time management skills. Almost equal numbers of participants responded "perhaps" (44.6%) or "yes" (44.2%) to the question of whether management personnel should be trained in time management.
A nonradial pulsation model for the rapidly rotating Delta Scuti star Kappa(2) Bootis
NASA Technical Reports Server (NTRS)
Kennelly, E. J.; Walker, G. A. H.; Hubeny, I.
1991-01-01
A sectorial nonradial pulsation model is used to construct theoretical line profiles which mimic the variations for Kappa(2) Boo. Synthetic spectra generated with the appropriate Teff and log g are used as input. It is found that the data can be reproduced by the combination of a high-degree l is approximately equal to 12 mode with P(osc) aproximately equal to 0.071 d, and a low-degree mode, l is approximately equal to 0-2 with P(osc) approximately equal to 0.071-0.079 d. The projected rotational velocity (v sin i - 115 +/-5 km/s) was determined by fitting synthetic line profiles to the observed spectra. The velocity amplitude of the high-degree oscillations is estimated to be about 3.5 km/s. It is found that the ratio of the horizontal and radial pulsation amplitudes is small (about 0.02) and consistent with p-mode oscillations. Comparisons are made with models invoking starspots, and it is impossible to fit the observations of Kappa(2) Boo by a starspot model without assuming unrealistic values of radius or equatorial velocity.
NASA Technical Reports Server (NTRS)
Mcgowan, J. J.; Smith, C. W.
1974-01-01
A technique consisting of a marriage between stress freezing photoelasticity and a numerical method was used to obtain stress intensity factors for natural cracks emanating from the corner at which a hole intersects a plate surface. Geometrics studied were: crack depth to thickness ratios of approximately 0.2, 0.5, and 0.75; crack depth to crack length ratios of approximately 1.0 to 2.0. All final crack geometries were grown under monotonic loading and growth was not self similar with most of the growth occurring through the thickness under remote extension. Stress intensity plate surface K sub s factors were determined at the intersection of the flaw border with the plate surface K sub s and with the edge of the hole K sub h. Results showed that for the relatively shallow flaws K sub h approximately equal to 1.5 K sub s, for the moderately deep flaws K sub h approximately equal to K sub s, and for the deep flaws K sub h approximately equal to 0.5 K sub s, revealing a severe sensitivity of K to flaw geometry.
Carbon Nanofibers Synthesized on Selective Substrates for Nonvolatile Memory and 3D Electronics
NASA Technical Reports Server (NTRS)
Kaul, Anupama B.; Khan, Abdur R.
2011-01-01
A plasma-enhanced chemical vapor deposition (PECVD) growth technique has been developed where the choice of starting substrate was found to influence the electrical characteristics of the resulting carbon nanofiber (CNF) tubes. It has been determined that, if the tubes are grown on refractory metallic nitride substrates, then the resulting tubes formed with dc PECVD are also electrically conducting. Individual CNFs were formed by first patterning Ni catalyst islands using ebeam evaporation and liftoff. The CNFs were then synthesized using dc PECVD with C2H2:NH3 = [1:4] at 5 Torr and 700 C, and approximately equal to 200-W plasma power. Tubes were grown directly on degenerately doped silicon <100> substrates with resistivity rho approximately equal to 1-5 meterohm-centimeter, as well as NbTiN. The approximately equal to 200-nanometer thick refractory NbTiN deposited using magnetron sputtering had rho approximately equal to 113 microohm-centimeter and was also chemically compatible with CNF synthesis. The sample was then mounted on a 45 beveled Al holder, and placed inside a SEM (scanning electron microscope). A nanomanipulator probe stage was placed inside the SEM equipped with an electrical feed-through, where tungsten probes were used to make two-terminal electrical measurements with an HP 4156C parameter analyzer. The positive terminal nanoprobe was mechanically manipulated to physically contact an individual CNF grown directly on NbTiN as shown by the SEM image in the inset of figure (a), while the negative terminal was grounded to the substrate. This revealed the tube was electrically conductive, although measureable currents could not be detected until approximately equal to 6 V, after which point current increased sharply until compliance (approximately equal to 50 nA) was reached at approximately equal to 9.5 V. A native oxide on the tungsten probe tips may contribute to a tunnel barrier, which could be the reason for the suppressed transport at low biases. Currents up to approximately 100 nA could be cycled, which are likely to propagate via the tube surface, or sidewalls, rather than the body, which is shown by the I-V in figure (a). Electrical conduction via the sidewalls is a necessity for dc NEMS (nanoelectromechanical system) applications, more so than for the field emission applications of such tubes. During the tests, high conductivity was expected, because both probes were shorted to the substrate, as shown by curve 1 in the I-V characteristic in figure (b). When a tube grown on NbTiN was probed, the response was similar to the approximately equal to 100 nA and is represented by curve 2 in figure (b), which could be cycled and propagated via the tube surface or the sidewalls. However, no measureable currents for the tube grown directly on Si were observed as shown by curve 3 in figure (b), even after testing over a range of samples. This could arise from a dielectric coating on the sidewalls for tubes on Si. As a result of the directional nature of ion bombardment during dc PECVD, Si from the substrate is likely re-sputtered and possibly coats the sidewalls.
Mean circulatory filling pressure: potential problems with measurement.
Gaddis, M L; Rothe, C F; Tunin, R S; Moran, M; MacAnespie, C L
1986-10-01
Three experimental series using 22 acutely splenectomized mongrel dogs were completed to 1) compare fibrillation (Fib) and acetylcholine (ACh) injection as methods to stop the heart for the mean circulatory filling pressure (Pmcf) maneuver, and 2) test whether Pmcf equals portal venous pressure 7 s after heart stoppage (Pportal7s). Blood volume changes of -10, -20, +10, or +20 ml/kg were imposed and Pmcf and Pportal measurements were obtained. Pportal7s and Pmcf were significantly different with volume depletion but were similar under control conditions. Pmcf with ACh and Pmcf with Fib were significantly different only after a volume change of -20 ml/kg. However, severe pulmonary congestion and atelectasis were detected in animals where Ach was used to stop the heart. In some cases (with injection directly into the pulmonary artery) the damage was severe enough to cause irreversible arterial hypoxia. Thus we conclude that the repeated use of ACh may exert a detrimental influence on pulmonary function, changing the physiological status of the experimental animal. Also, the central venous pressure at 7 s of heart stoppage (Pcv7s) is not a fully accurate estimate of the true mean circulatory filling pressure during the Pmcf maneuver, because Pcv7s did not equal the Pportal7s under all experimental conditions.
Vibration Damping Circuit Card Assembly
NASA Technical Reports Server (NTRS)
Hunt, Ronald Allen (Inventor)
2016-01-01
A vibration damping circuit card assembly includes a populated circuit card having a mass M. A closed metal container is coupled to a surface of the populated circuit card at approximately a geometric center of the populated circuit card. Tungsten balls fill approximately 90% of the metal container with a collective mass of the tungsten balls being approximately (0.07) M.
Accurate expressions for solar cell fill factors including series and shunt resistances
NASA Astrophysics Data System (ADS)
Green, Martin A.
2016-02-01
Together with open-circuit voltage and short-circuit current, fill factor is a key solar cell parameter. In their classic paper on limiting efficiency, Shockley and Queisser first investigated this factor's analytical properties showing, for ideal cells, it could be expressed implicitly in terms of the maximum power point voltage. Subsequently, fill factors usually have been calculated iteratively from such implicit expressions or from analytical approximations. In the absence of detrimental series and shunt resistances, analytical fill factor expressions have recently been published in terms of the Lambert W function available in most mathematical computing software. Using a recently identified perturbative relationship, exact expressions in terms of this function are derived in technically interesting cases when both series and shunt resistances are present but have limited impact, allowing a better understanding of their effect individually and in combination. Approximate expressions for arbitrary shunt and series resistances are then deduced, which are significantly more accurate than any previously published. A method based on the insights developed is also reported for deducing one-diode fits to experimental data.
NASA Technical Reports Server (NTRS)
Fan, Xiao-Ming; Tytler, David
1994-01-01
We present optical spectra of the most luminous known quasi stellar object (QSO) HS 1946+7658 (z(sub em) = 3.051). Our spectra have both full wavelength coverage, 3240-10570 A, and in selected regions, either high signal-to-noise ratio, SNR approximately equals 40-100, or unusually high approximately 10 km/sec resolution, and in parts of the Ly alpha forest and to the red of Ly alpha emission they are among the best published. We find 113 Ly alpha systems and six metal-line systems, three of which are new. The metal systems at z(sub abs) = 2.844 and 3.050 have complex velocity structure with four and three prominent components, respectively. We find that the system at z(sub abs) = 2.844 is a damped Ly alpha absorption (DLA) system, with a neutral hydrogen column density of log N(H I) = 20.2 +/- 0.4, and it is the cause of the Lyman limit break at lambda approximately equals 3520 A. We believe that most of the H I column density in this system is in z(sub abs) = 2.8443 component which shows the strongest low-ionization absorption lines. The metal abundance in the gas phase of the system is (M/H) approximately equals -2.6 +/- 0.3, with a best estimate of (M/H) = -2.8, with ionizaion parameter log gamma = -2.75, from a photoionization model. The ratios of the logarithmic abundances of C, O, Al, and Si are all within a factor of 2 of solar, which is important for two reasons. First, we believe that the gas abundances which we measure are close to the total abundances, because the ratio of aluminum to other elements is near cosmic, and Al is a refractory element which depletes very readily like chromium, in the interstellar medium. Second, we do not see the enhancement of O with respect to C of (O/C) approximately equals 0.5-0.9 reported in three partial Lyman limit systems by Reimers et al. (1992) and Vogel & Reimers (1993); we measure (O/C) = -0.06 for observed ions and (O/C) approximately equals 0.2 after ionization corrections, which is consistent with solar abundances. We see C II*(lambda 1335) offset by 15 km/sec with respect to C II(lambda 1334), presumably because the gas density varies from 2 to 8 cm(exp -3) with changing velocity in the DLA system. These densities imply that the damped component is 6-25 pc thick, which is reasonable for a single cloud in a cold spiral disk. They also imply that the cloud is relatively highly ionized with more C III than C II, more O III than O I, and log N(H I) = 20.72, which is 3 times the H I column. The system at z(abs) = 1.7382 is also believed to be damped with N(H I) approximately equals 10(exp 21) cm(exp -2), because we see Cr II, but its Ly alpha line will never be seen because it is below the Lyman limit of the other DLA system. We see a 2.6 sigma lack of Ly alpha forest lines well away from the QSO redshift, which may be a chance fluctuation. We also see a correlation between column density N(H I) and Doppler parameter b for 96 unsaturated Ly Alpha forest absorption lines, and although this correlation persists in the 36 Ly alpha lines which lie in regions where the SNR approximately equals 8-16, we agree with Rauch et al. (1993) that it is probably a bogus effect of low supernova remnant (SNR). The same applies to lines with very low b values: in regions where SNR less than or equal to 8 we see many Ly alpha lines which appear to have 10 less than or equal to b less than or equal to 20, but when 8 less than or equal to SNR less than or equal to 16 we see only one line with b less than or equal to 15 km/sec, and two others which we believe have b less than or equal to 20, with values of 20 and 16 km/sec. Traditional Ly alpha line samples which include all lines which have W/sigma(W) greater than or equal to 4 are not adequate to explore the distribution of the properties of individual clouds, because we need much higher (W/sigma(W)) and SNR to avoid the strong biases.
NASA Technical Reports Server (NTRS)
Dobson, C. C.; Eskridge, R. H.; Lee, M. H.
2000-01-01
A four-channel laser transmissometer has been used to probe the soot content of the exhaust plume of the X-34 60k-lb thrust Fastrac rocket engine at NASA's Marshall Space Flight Center. The transmission measurements were made at an axial location approximately equal 1.65 nozzle diameters from the exit plane and are interpreted in terms of homogeneous radial zones to yield extinction coefficients from 0.5-8.4 per meter. The corresponding soot mass density, spatially averaged over the plume cross section, is, for Rayleigh particles, approximately equal 0.7 microgram/cc, and alternative particle distributions are briefly considered. Absolute plume radiance at the laser wavelength (515 nm) is estimated from the data at approximately equal 2,200 K equivalent blackbody temperature, and temporal correlations in emission from several spatial locations are noted.
Fridrich, Christopher J.; Thompson, Ren A.
2011-01-01
The Death Valley region, of southeast California and southwest Nevada, is distinct relative to adjacent regions in its structural style and resulting topography, as well as in the timing of basin-range extension. Cenozoic basin-fill strata, ranging in age from greater than or equal to 40 to approximately 2 million years are common within mountain-range uplifts in this region. The tectonic fragmentation and local uplift of these abandoned basin-fills indicate a multistage history of basin-range tectonism. Additionally, the oldest of these strata record an earlier, pre-basin-range interval of weak extension that formed broad shallow basins that trapped sediments, without forming basin-range topography. The Cenozoic basin-fill strata record distinct stratigraphic breaks that regionally cluster into tight age ranges, constrained by well-dated interbedded volcanic units. Many of these stratigraphic breaks are long recognized formation boundaries. Most are angular unconformities that coincide with abrupt changes in depositional environment. Deposits that bound these unconformities indicate they are weakly diachronous; they span about 1 to 2 million years and generally decrease in age to the west within individual basins and regionally, across basin boundaries. Across these unconformities, major changes are found in the distribution and provenance of basin-fill strata, and in patterns of internal facies. These features indicate rapid, regionally coordinated changes in strain patterns defined by major active basin-bounding faults, coincident with step-wise migrations of the belt of active basin-range tectonism. The regionally correlative unconformities thus record short intervals of radical tectonic change, here termed "tectonic reorganizations." The intervening, longer (about 3- to 5-million-year) interval of gradual, monotonic evolution in the locus and style of tectonism are called "tectonic stages." The belt of active tectonism in the Death Valley region has abruptly stepped westward during three successive tectonic reorganizations that intervened between four stages of basin-range tectonism, the youngest of which is ongoing. These three tectonic reorganizations also intervened between four stages of volcanic activity, each of which has been distinct in the compositions of magmas erupted, in eruption rates, and in the locus of volcanic activity—which has stepped progressively westward, in close coordination with the step-wise migrations in the locus of basin-range extension. The timing of the Cenozoic tectonic reorganizations in the Death Valley region correlates closely with the documented timing of episodic reorganizations of the boundary between the Pacific and North American plates, to the west and southwest. This supports models that explain the widely distributed transtensional tectonism in southwestern North America since approximately 40 million years ago as resulting from traction imposed by the adjacent, divergent Pacific plate.
Rank Weighting in Multiattribute Utility Decision Making: Avoiding the Pitfalls of Equal Weights.
1979-09-01
set change are discussed in relation to the conditions of Wainer’s (Wainer, 1976) ’ equal weights theorem’ and the resulting sensitivity to weighting of...as equal weights. Rank weighting of importance dimensions demonstrate marked improvement of approximation as reflected in both Pearson and rank order
Recent Developments in Transition-Edge Strip Detectors for Solar X-Rays
NASA Technical Reports Server (NTRS)
Rausch, Adam J.; Deiker, Steven W.; Hilton, Gene; Irwin, Kent D.; Martinez-Galarce, Dennis S.; Shing, Lawrence; Stern, Robert A.; Ullom, Joel N.; Vale, Leila R.
2008-01-01
LMSAL and NIST are developing position-sensitive x-ray strip detectors based on Transition Edge Sensor (TES) microcalorimeters optimized for solar physics. By combining high spectral (E/ delta E approximately equals 1600) and temporal (single photon delta t approximately equals 10 micro s) resolutions with imaging capabilities, these devices will be able to study high-temperature (>l0 MK) x-ray lines as never before. Diagnostics from these lines should provide significant new insight into the physics of both microflares and the early stages of flares. Previously, the large size of traditional TESs, along with the heat loads associated with wiring large arrays, presented obstacles to using these cryogenic detectors for solar missions. Implementing strip detector technology at small scales, however, addresses both issues: here, a line of substantially smaller effective pixels requires only two TESs, decreasing both the total array size and the wiring requirements for the same spatial resolution. Early results show energy resolutions of delta E(sub fwhm) approximately equals 30 eV and spatial resolutions of approximately 10-15 micron, suggesting the strip-detector concept is viable.
A comparison of visual and kinesthetic-tactual displays for compensatory tracking
NASA Technical Reports Server (NTRS)
Jagacinski, R. J.; Flach, J. M.; Gilson, R. D.
1983-01-01
Recent research on manual tracking with a kinesthetic-tactual (KT) display suggests that under certain conditions it can be an effective alternative or supplement to visual displays. In order to understand better how KT tracking compares with visual tracking, both a critical tracking and stationary single-axis tracking tasks were conducted with and without velocity quickening. In the critical tracking task, the visual displays were superior, however, the quickened KT display was approximately equal to the unquickened visual display. In stationary tracking tasks, subjects adopted lag equalization with the quickened KT and visual displays, and mean-squared error scores were approximately equal. With the unquickened displays, subjects adopted lag-lead equalization, and the visual displays were superior. This superiority was partly due to the servomotor lag in the implementation of the KT display and partly due to modality differences.
Equal Pay for Equal Work in Academic Obstetrics and Gynecology.
Eichelberger, Kacey Y
2018-02-01
The most compelling data suggest women in academic obstetrics and gynecology earn approximately $36,000 less than male colleagues per year in regression models correcting for commonly cited explanatory variables. Although residual confounding may exist, academic departments in the United States should consider rigorous examination of their own internal metrics around salary to ensure gender-neutral compensation, commonly referred to as equal pay for equal work.
NASA Technical Reports Server (NTRS)
Alloin, D.; Santos-Lleo, M.; Peterson, B. M.; Wamsteker, W.; Altieri, B.; Brinkmann, W.; Clavel, J.; Crenshaw, D. M.; George, I. M.; Glass, I. S.;
1995-01-01
To better understand the physical processes that produce the continuous emission in active galactic nuclei (AGN), a snapshot of the overall continuous energy distribution of NGC 3783, from gamma ray to radio wavelengths, has been obtained within the framework of the World Astronomy Days. The data collected in this campaign are from GRO, ROSAT, Voyager 2, IUE, HST, CTIO, SAAO, and the VLA. Great care has been taken in disentangling the genuine AGN continusous emission from other contributions; depending on the waveband, the latter might be (1) unrelated contaminating sources in cases where the instrument field of view is large (2) components within which the AGN is embedded, such as the stellar bulge population which accounts for a significant fraction of the optical continuum, and free-bound and FE2 blends wich contribute to the ultraviolet flux. After correction for these other contributins, the continuous emission of the isolated AGN appears to be rather flat (i.e., approximately equal energy per unit logarithmic frequency) from soft gamma ray to infrared wavelengths. At high energies (0.1 MeV to 0.1 keV), the AGN continuum can be fitted by a power law F nu approaches Nu(exp -a) with a spectral index of alpha approximately 1. At longer wavelengths, two excesses above this power law ('bumps') appear: in the ultraviolet, the classical big blue bump, which can be interpreted as thermal emission from the accretion disc surrounding a massive black hole, and in the infrared, a second bump which can be ascribed to thermal emission from dust in the vicinity of the AGN, heated by ultraviolet radiation from the central source. By fitting accretion-disk models to the observed AGN spectral energy distribution, we find values for the accretion disk innermost temperature, accretion rate, and black hole mass, with some differences that depend on whether or not we extrapolate the high energy power law up to infrared wavelengths. A fit to the IR bump above the extended alpha equals 1 power law suggests the presence of a dust component covering the region from a distance rho approximately equals 80 light days (hot grains at a temperature of approximately equals 1500 K) to rho approximately equals 60 light years (cool grains at T approximately equals 200 K). The total mass of dust is around 60 solar masses.
Oscillating-Linear-Drive Vacuum Compressor for CO2
NASA Technical Reports Server (NTRS)
Izenson, Michael G.; Shimko, Martin
2005-01-01
A vacuum compressor has been designed to compress CO2 from approximately equal to 1 psia (approximately equal to 6.9 kPa absolute pressure) to approximately equal to 75 psia (approximately equal to 0.52 MPa), to be insensitive to moisture, to have a long operational life, and to be lightweight, compact, and efficient. The compressor consists mainly of (1) a compression head that includes hydraulic diaphragms, a gas-compression diaphragm, and check valves; and (2) oscillating linear drive that includes a linear motor and a drive spring, through which compression force is applied to the hydraulic diaphragms. The motor is driven at the resonance vibrational frequency of the motor/spring/compression-head system, the compression head acting as a damper that takes energy out of the oscillation. The net effect of the oscillation is to cause cyclic expansion and contraction of the gas-compression diaphragm, and, hence, of the volume bounded by this diaphragm. One-way check valves admit gas into this volume from the low-pressure side during expansion and allow the gas to flow out to the high-pressure side during contraction. Fatigue data and the results of diaphragm stress calculations have been interpreted as signifying that the compressor can be expected to have an operational life of greater than 30 years with a confidence level of 99.9 percent.
40 CFR 86.232-94 - Vehicle preconditioning.
Code of Federal Regulations, 2012 CFR
2012-07-01
... vehicle shall be moved to the test area and the following operations performed: (1) The fuel tank(s) shall be filled to approximately the prescribed “tank fuel volume” with the test fuel specified § 86.213... existing fuel must be drained prior to the fuel fill. The test fuel shall be at a temperature less than or...
40 CFR 86.232-94 - Vehicle preconditioning.
Code of Federal Regulations, 2013 CFR
2013-07-01
... vehicle shall be moved to the test area and the following operations performed: (1) The fuel tank(s) shall be filled to approximately the prescribed “tank fuel volume” with the test fuel specified § 86.213... existing fuel must be drained prior to the fuel fill. The test fuel shall be at a temperature less than or...
40 CFR 86.232-94 - Vehicle preconditioning.
Code of Federal Regulations, 2010 CFR
2010-07-01
... vehicle shall be moved to the test area and the following operations performed: (1) The fuel tank(s) shall be filled to approximately the prescribed “tank fuel volume” with the test fuel specified § 86.213... existing fuel must be drained prior to the fuel fill. The test fuel shall be at a temperature less than or...
7 CFR 160.19 - Samples of rosin for grading.
Code of Federal Regulations, 2011 CFR
2011-01-01
... for grading. Samples of rosin for grading shall be approximately cubical in shape, and shall be seven... of the following methods: (a) By cutting or cleaving the same from a lump of the rosin removed from... container filled. (e) By withdrawing a quantity of molten rosin from a full drum that has been filled after...
7 CFR 160.19 - Samples of rosin for grading.
Code of Federal Regulations, 2010 CFR
2010-01-01
... for grading. Samples of rosin for grading shall be approximately cubical in shape, and shall be seven... of the following methods: (a) By cutting or cleaving the same from a lump of the rosin removed from... container filled. (e) By withdrawing a quantity of molten rosin from a full drum that has been filled after...
NASA Astrophysics Data System (ADS)
Ushakov, Anton; Orlov, Alexey; Sovach, Victor P.
2018-03-01
This article presents the results of research filling of gas centrifuge cascade for separation of the multicomponent isotope mixture with process gas by various feed flow rate. It has been used mathematical model of the nonstationary hydraulic and separation processes occurring in the gas centrifuge cascade. The research object is definition of the regularity transient of nickel isotopes into cascade during filling of the cascade. It is shown that isotope concentrations into cascade stages after its filling depend on variable parameters and are not equal to its concentration on initial isotope mixture (or feed flow of cascade). This assumption is used earlier any researchers for modeling such nonstationary process as set of steady-state concentration of isotopes into cascade. Article shows physical laws of isotope distribution into cascade stage after its filling. It's shown that varying each parameters of cascade (feed flow rate, feed stage number or cascade stage number) it is possible to change isotope concentration on output cascade flows (light or heavy fraction) for reduction of duration of further process to set of steady-state concentration of isotopes into cascade.
Effect of tank geometry on its average performance
NASA Astrophysics Data System (ADS)
Orlov, Aleksey A.; Tsimbalyuk, Alexandr F.; Malyugin, Roman V.; Leontieva, Daria A.; Kotelnikova, Alexandra A.
2018-03-01
The mathematical model of non-stationary filling of vertical submerged tanks with gaseous uranium hexafluoride is presented in the paper. There are calculations of the average productivity, heat exchange area, and filling time of various volumes tanks with smooth inner walls depending on their "height : radius" ratio as well as the average productivity, degree, and filling time of horizontal ribbing tank with volume 6.10-2 m3 with change central hole diameter of the ribs. It has been shown that the growth of "height / radius" ratio in tanks with smooth inner walls up to the limiting values allows significantly increasing tank average productivity and reducing its filling time. Growth of H/R ratio of tank with volume 1.0 m3 to the limiting values (in comparison with the standard tank having H/R equal 3.49) augments tank productivity by 23.5 % and the heat exchange area by 20%. Besides, we have demonstrated that maximum average productivity and a minimum filling time are reached for the tank with volume 6.10-2 m3 having central hole diameter of horizontal ribs 6.4.10-2 m.
Metadynamics convergence law in a multidimensional system
NASA Astrophysics Data System (ADS)
Crespo, Yanier; Marinelli, Fabrizio; Pietrucci, Fabio; Laio, Alessandro
2010-05-01
Metadynamics is a powerful sampling technique that uses a nonequilibrium history-dependent process to reconstruct the free-energy surface as a function of the relevant collective variables s . In Bussi [Phys. Rev. Lett. 96, 090601 (2006)] it is proved that, in a Langevin process, metadynamics provides an unbiased estimate of the free energy F(s) . We here study the convergence properties of this approach in a multidimensional system, with a Hamiltonian depending on several variables. Specifically, we show that in a Monte Carlo metadynamics simulation of an Ising model the time average of the history-dependent potential converge to F(s) with the same law of an umbrella sampling performed in optimal conditions (i.e., with a bias exactly equal to the negative of the free energy). Remarkably, after a short transient, the error becomes approximately independent on the filling speed, showing that even in out-of-equilibrium conditions metadynamics allows recovering an accurate estimate of F(s) . These results have been obtained introducing a functional form of the history-dependent potential that avoids the onset of systematic errors near the boundaries of the free-energy landscape.
Metadynamics convergence law in a multidimensional system.
Crespo, Yanier; Marinelli, Fabrizio; Pietrucci, Fabio; Laio, Alessandro
2010-05-01
Metadynamics is a powerful sampling technique that uses a nonequilibrium history-dependent process to reconstruct the free-energy surface as a function of the relevant collective variables s . In Bussi [Phys. Rev. Lett. 96, 090601 (2006)] it is proved that, in a Langevin process, metadynamics provides an unbiased estimate of the free energy F(s) . We here study the convergence properties of this approach in a multidimensional system, with a Hamiltonian depending on several variables. Specifically, we show that in a Monte Carlo metadynamics simulation of an Ising model the time average of the history-dependent potential converge to F(s) with the same law of an umbrella sampling performed in optimal conditions (i.e., with a bias exactly equal to the negative of the free energy). Remarkably, after a short transient, the error becomes approximately independent on the filling speed, showing that even in out-of-equilibrium conditions metadynamics allows recovering an accurate estimate of F(s) . These results have been obtained introducing a functional form of the history-dependent potential that avoids the onset of systematic errors near the boundaries of the free-energy landscape.
Aftershocks of the 13 May 1993 Shumagin Alaska earthquake
Lu, Zhong; Wyss, Max; Tytgat, Guy; McNutt, Steve; Stihler, Scott
1994-01-01
The 13 May 1993 Ms 6.9 Shumagin earthquake had an aftershock sequence of 247 earthquakes with magnitudes greater than or equal to 1.5 by 1 June 1993. Of these aftershocks, 79 were located by using S-P travel times at the only two stations within 570 km of the mainshock epicenter. The rupture area inferred from the aftershocks is about 600 km2 and we estimate for the mainshock a mean fault displacement of 1.0 m and a 28 bar stress drop. The magnitude-frequency plots give a b-value for the aftershock sequence of about 0.4, which is low compared to the background value of approximately 0.8. The decay of the aftershock sequence followed the modified Omori law with a p-value of 0.79, which is also lower than the typical values of about 1.1 observed in Alaska. Both of these facts can be interpreted as indicating relatively high ambient stress in the Shumagin seismic gap and the possibility that the 13 May earthquake was a foreshock to a larger gap-filling event to occur within the next few years.
Variability of site response in Seattle, Washington
Hartzell, S.; Carver, D.; Cranswick, E.; Frankel, A.
2000-01-01
Ground motion from local earthquakes and the SHIPS (Seismic Hazards Investigation in Puget Sound) experiment is used to estimate site amplification factors in Seattle. Earthquake and SHIPS records are analyzed by two methods: (1) spectral ratios relative to a nearby site on Tertiary sandstone, and (2) a source/site spectral inversion technique. Our results show site amplifications between 3 and 4 below 5 Hz for West Seattle relative to Tertiary rock. These values are approximately 30% lower than amplification in the Duwamish Valley on artificial fill, but significantly higher than the calculated range of 2 to 2.5 below 5 Hz for the till-covered hills east of downtown Seattle. Although spectral amplitudes are only 30% higher in the Duwamish Valley compared to West Seattle, the duration of long-period ground motion is significantly greater on the artificial fill sites. Using a three-dimensional displacement response spectrum measure that includes the effects of ground-motion duration, values in the Duwamish Valley are 2 to 3 times greater than West Seattle. These calculations and estimates of site response as a function of receiver azimuth point out the importance of trapped surface-wave energy within the shallow, low-velocity, sedimentary layers of the Duwamish Valley. One-dimensional velocity models yield spectral amplification factors close to the observations for till sites east of downtown Seattle and the Duwamish Valley, but underpredict amplifications by a factor of 2 in West Seattle. A two-dimensional finite-difference model does equally well for the till sites and the Duwamish Valley and also yields duration estimates consistent with the observations for the Duwamish Valley. The two-dimensional model, however, still underpredicts amplification in West Seattle by up to a factor of 2. This discrepancy is attributed to 3D effects, including basin-edge-induced surface waves and basin-geometry-focusing effects, caused by the proximity of the Seattle thrust fault and the sediment-filled Seattle basin.
NASA Technical Reports Server (NTRS)
Stecker, Floyd W.
2014-01-01
The observation of two PetaelectronVolt (PeV)-scale neutrino events reported by Ice Cube allows one to place constraints on Lorentz invariance violation (LIV) in the neutrino sector. After first arguing that at least one of the PetaelectronVolt IceCube events was of extragalactic origin, I derive an upper limit for the difference between putative superluminal neutrino and electron velocities of less than or equal to approximately 5.6 x 10(exp -19) in units where c = 1, confirming that the observed PetaelectronVolt neutrinos could have reached Earth from extragalactic sources. I further derive a new constraint on the superluminal electron velocity, obtained from the observation of synchrotron radiation from the Crab Nebula flare of September, 2010. The inference that the greater than 1 GigaelectronVolt gamma-rays from synchrotron emission in the flare were produced by electrons of energy up to approx. 5.1 PetaelectronVolt indicates the nonoccurrence of vacuum Cerenkov radiation by these electrons. This implies a new, strong constraint on superluminal electron velocities delta(sub e) less than or equal to approximately 5 x 10(exp -21). It immediately follows that one then obtains an upper limit on the superluminal neutrino velocity alone of delta(sub v) less than or equal to approximately 5.6 x 10(exp -19), many orders of magnitude better than the time-of-flight constraint from the SN1987A neutrino burst. However, if the electrons are subluminal the constraint on the absolute value of delta(sub e) less than or equal to approximately 8 x 10(exp -17), obtained from the Crab Nebula gamma-ray spectrum, places a weaker constraint on superluminal neutrino velocity of delta(sub v) less than or equal to approximately 8 x 10(exp -17).
[EPR study of iron status in human body during intensive physical activity].
Ibragimova, M I; Chushnikov, A I; Cherepnev, G V; Petukhov, V Iu; Zheglov, E P
2014-01-01
The iron metabolism was studied in serum blood samples collected from 26 professional sportsmen undergoing intensive physical exercises using EPR combined with haematological and biochemical laboratory tests. Only 23% of EPR spectra (n = 6) were practically normal while in the rest spectra additional abnormal absorption lines were detected. Presumably, the significant portion of new signals may be caused by different cytochromes. Moreover, the anisotropic signals with g1 approximately equal to 2.02; g2 approximately equal to 1.94 and g3 approximately equal to 1.86 registered in some spectra pointed to the sulfur-iron centers. There was nearly linear correlation between the concentration of Fe3+ in transfferin (Fe(3+)-Tf) obtained from the EPR spectra and the serum iron concentration measured by absorption photometry both for sportsmen and controls (healthy individuals and patients with different diseases). At equal serum iron concentrations the Fe(3+)-Tf level was higher in sportsmen than that in controls. The Pearson correlation coefficient (r) for Fe(3+)-Tf and serum iron values was equal to 0.89 in sportsmen versus r = 0.97 in controls. Additional new lines in serum EPR spectra of professional sportsmen prove the suitability of EPR assay for scheduled medical exams since routinebiochemical and haematological tests are insufficient to discover all abnormalities in iron metabolism under intensive physical exercises.
NASA Technical Reports Server (NTRS)
Goldberg, M.; Tadmor, E.
1986-01-01
The purpose of this paper is to achieve more versatile, convenient stability criteria for a wide class of finite-difference approximations to initial boundary value problems associated with the hyperbolic system u sub t = au sub x + Bu + f in the quarter-plane x greater than or equal to 0, t greater than or equal to 0. With these criteria, stability is easily established for a large number of examples, thus incorporating and generalizing many of the cases studied in recent literature.
Limits of Wave Runup and Corresponding Beach-Profile Change from Large-Scale Laboratory Data
2010-01-01
A nearly vertical scarp developed after 40 min of wave action, with the upper limit of beach change identified at the toe of the dune scarp. and...change UL was found to approximately equal the vertical excursion of total wave runup, Rtw. An exception was runs where beach or dune scarps were...approximately equal the vertical excursion of total wave runup, Rtw. An exception was runs where beach or dune scarps were produced, which substantially limit the
Active Response Gravity Offload System
NASA Technical Reports Server (NTRS)
Valle, Paul; Dungan, Larry; Cunningham, Thomas; Lieberman, Asher; Poncia, Dina
2011-01-01
The Active Response Gravity Offload System (ARGOS) provides the ability to simulate with one system the gravity effect of planets, moons, comets, asteroids, and microgravity, where the gravity is less than Earth fs gravity. The system works by providing a constant force offload through an overhead hoist system and horizontal motion through a rail and trolley system. The facility covers a 20 by 40-ft (approximately equals 6.1 by 12.2m) horizontal area with 15 ft (approximately equals4.6 m) of lifting vertical range.
Asymmetrical color filling-in from the nasal to the temporal side of the blind spot
Li, Hui; Luo, Junxiang; Lu, Yiliang; Kan, Janis; Spillmann, Lothar; Wang, Wei
2014-01-01
The physiological blind spot, corresponding to the optic disk in the retina, is a relatively large (6 × 8°) area in the visual field that receives no retinal input. However, we rarely notice the existence of it in daily life. This is because the blind spot fills in with the brightness, color, texture, and motion of the surround. The study of filling-in enables us to better understand the creative nature of the visual system, which generates perceptual information where there is none. Is there any retinotopic rule in the color filling-in of the blind spot? To find out, we used mono-colored and bi-colored annuli hugging the boundary of the blind spot. We found that mono-colored annuli filled in the blind spot uniformly. By contrast, bi-colored annuli, where one half had a given color, while the other half had a different one, filled in the blind spot asymmetrically. Specifically, the color surrounding the nasal half typically filled in about 75% of the blind spot area, whereas the color surrounding the temporal half filled in only about 25%. This asymmetry was dependent on the relative size of the half rings, but not the two colors used, and was absent when the bi-colored annulus was rotated by 90°. Here, the two colors on the upper and lower sides of the blind spot filled in the enclosed area equally. These results suggest that the strength of filling-in decreases with distance from the fovea consistent with the decrease of the cortical magnification factor. PMID:25100977
Asymmetrical color filling-in from the nasal to the temporal side of the blind spot.
Li, Hui; Luo, Junxiang; Lu, Yiliang; Kan, Janis; Spillmann, Lothar; Wang, Wei
2014-01-01
The physiological blind spot, corresponding to the optic disk in the retina, is a relatively large (6 × 8°) area in the visual field that receives no retinal input. However, we rarely notice the existence of it in daily life. This is because the blind spot fills in with the brightness, color, texture, and motion of the surround. The study of filling-in enables us to better understand the creative nature of the visual system, which generates perceptual information where there is none. Is there any retinotopic rule in the color filling-in of the blind spot? To find out, we used mono-colored and bi-colored annuli hugging the boundary of the blind spot. We found that mono-colored annuli filled in the blind spot uniformly. By contrast, bi-colored annuli, where one half had a given color, while the other half had a different one, filled in the blind spot asymmetrically. Specifically, the color surrounding the nasal half typically filled in about 75% of the blind spot area, whereas the color surrounding the temporal half filled in only about 25%. This asymmetry was dependent on the relative size of the half rings, but not the two colors used, and was absent when the bi-colored annulus was rotated by 90°. Here, the two colors on the upper and lower sides of the blind spot filled in the enclosed area equally. These results suggest that the strength of filling-in decreases with distance from the fovea consistent with the decrease of the cortical magnification factor.
Interior, building 810, view to west from approximately midhangar. Area ...
Interior, building 810, view to west from approximately mid-hangar. Area of photo encompasses approximately 1/4 of the interior space, with the KC-10 tanker aircraft and the figures beneath it giving an idea of scale, 90mm lens plus electronic flash fill lightening. - Travis Air Force Base, B-36 Hangar, Between Woodskill Avenue & Ellis, adjacent to Taxiway V & W, Fairfield, Solano County, CA
The Accretion Disk Wind in the Black Hole GRS 1915 + 105
NASA Technical Reports Server (NTRS)
Miller, J.M.; Raymond, J.; Fabian, A. C.; Gallo, E.; Kaastra, J.; Kallman, T.; King, A. L.; Proga, D.; Reynolds, C. S.; Zoghbi, A.
2016-01-01
We report on a 120 kiloseconds Chandra/HETG spectrum of the black hole GRS 1915+105. The observation was made during an extended and bright soft state in 2015 June. An extremely rich disk wind absorption spectrum is detected, similar to that observed at lower sensitivity in 2007. The very high resolution of the third-order spectrum reveals four components to the disk wind in the Fe K band alone; the fastest has a blueshift of v = 0.03 c (velocity equals 0.03 the speed of light). Broadened reemission from the wind is also detected in the first-order spectrum, giving rise to clear accretion disk P Cygni profiles. Dynamical modeling of the re-emission spectrum gives wind launching radii of r approximately equal to 10 (sup 2-4) GM (Gravitational constant times Mass) divided by c (sup 2) (the speed of light squared). Wind density values of n approximately equal to 10 (sup 13-16) per cubic centimeter are then required by the ionization parameter formalism. The small launching radii, high density values, and inferred high mass outflow rates signal a role for magnetic driving. With simple, reasonable assumptions, the wind properties constrain the magnitude of the emergent magnetic field to be B approximately equal to 10 (sup 3-4) G (Gravitational constant) if the wind is driven via magnetohydrodynamic (MHD) pressure from within the disk and B approximately equal to 10 (sup 4-5) G (Gravitational constant) if the wind is driven by magnetocentrifugal acceleration. The MHD estimates are below upper limits predicted by the canonical alpha-disk model. We discuss these results in terms of fundamental disk physics and black hole accretion modes.
to return to the AJCN Home page State of Alaska > DOLWD > Alaska Job Center Network > Job Job Center Network is an equal opportunity employer/program. Auxiliary aids and services are available Alaska Job Center Network (AJCN). Positions filled through AJCN are recruited at the local level through
1991-04-03
deliveries of goods from the indication lists in equal defray the costs related to setting up the new jobs . This annual amounts between 1991 and 1994, with...Development of Nuclear Energy Industry must also contain a commitment by the employer that Described the new jobs will be filled by applicants recommended by
Federal Register 2010, 2011, 2012, 2013, 2014
2011-03-11
... application filed on March 17, 2010, proposed filling approximately 700 acres of open-water benthic habitat... filling of up to 400 acres of open-water bottom in the Mississippi Sound, the construction of wharfs... the USACE in deciding whether to issue a Department of the Army permit. The purpose of this Notice of...
Simple Model of a Rolling Water-Filled Bottle on an Inclined Ramp
ERIC Educational Resources Information Center
Lin, Shihao; Hu, Naiwen; Yao, Tianchen; Chu, Charles; Babb, Simona; Cohen, Jenna; Sangiovanni, Giana; Watt, Summer; Weisman, Danielle; Klep, James; Walecki, Wojciech J.; Walecki, Eve S.; Walecki, Peter S.
2015-01-01
We investigate a water-filled bottle rolling down an incline and ask the following question: is a rolling bottle better described by a model ignoring all internal motion where the bottle is approximated by a material point sliding down an incline, or is it better described by a rigid solid cylinder rolling down the incline without skidding? The…
Dombrovski, Viatcheslav V.; Driscoll, David I.; Shovkhet, Boris A.
2001-01-01
A superconducting electromechanical rotating (SER) device, such as a synchronous AC motor, includes a superconducting field winding and a one-layer stator winding that may be water-cooled. The stator winding is potted to a support such as the inner radial surface of a support structure and, accordingly, lacks hangers or other mechanical fasteners that otherwise would complicate stator assembly and require the provision of an unnecessarily large gap between adjacent stator coil sections. The one-layer winding topology, resulting in the number of coils being equal to half the number of slots or other mounting locations on the support structure, allows one to minimize or eliminate the gap between the inner radial ends of adjacent straight sections of the stator coilswhile maintaining the gap between the coil knuckles equal to at least the coil width, providing sufficient room for electrical and cooling element configurations and connections. The stator winding may be potted to the support structure or other support, for example, by a one-step VPI process relying on saturation of an absorbent material to fill large gaps in the stator winding or by a two-step process in which small gaps are first filled via a VPI or similar operation and larger gaps are then filled via an operation that utilizes the stator as a portion of an on-site mold.
ERIC Educational Resources Information Center
Edwards, Lynne K.; Meyers, Sarah A.
Correlation coefficients are frequently reported in educational and psychological research. The robustness properties and optimality among practical approximations when phi does not equal 0 with moderate sample sizes are not well documented. Three major approximations and their variations are examined: (1) a normal approximation of Fisher's Z,…
76 FR 15007 - Proposed Collection; Comment Request
Federal Register 2010, 2011, 2012, 2013, 2014
2011-03-18
... filling out the form is approximately one hour per response and would likely be completed by an accountant... that it should take approximately one hour for an accountant or other professional to complete the form... past conversations with representatives of SBICs and accountants that have filed the form. \\3...
Investigation of Flash Fill{reg_sign} as a thermal backfill material
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ayers, P.H.; Charlton, C.B.; Frishette, C.W.
1995-09-01
Flash Fill{reg_sign} was created as a fast-setting, flowable backfill material made entirely from coal combustion by-products and water. Its quick-setting, self-leveling, self-compacting characteristics makes trench road repairs faster, easier, and more economical. Other uses include building foundations, fill around pipes, gas lines, and manholes, and replacement of weak subgrade beneath rooters. Flash Fill can be hand-excavated without the use of power assisted tools or machinery. To enhance thermal resistivity, the original Flash Fill mix was modified to include concrete sand. This resulted in a new Flash Fill, designated FSAND, with all of the aforementioned desirable characteristics of Flash Fill andmore » a thermal resistivity of approximately 50{degree} C-cm/watt. Thermal resistivity tests using conventional laboratory thermal probes, high-current thermal tests, and moisture migration tests have been performed to determine the properties of FSAND. As a result of these tests, FSAND has been approved for use as power cable thermal backfill on all AEP System distribution projects.« less
Reducing injection loss in drill strings
Drumheller, Douglas S.
2004-09-14
A system and method for transferring wave energy into or out of a periodic structure having a characteristic wave impedance profile at a prime frequency, the characteristic wave impedance profile comprising a real portion and an imaginary portion, comprising: locating one or more energy transfer elements each having a wave impedance at the prime frequency approximately equal to the real portion of the characteristic wave impedance at one or more points on the periodic structure with the imaginary portion approximately equaling zero; and employing the one or more energy transfer elements to transfer wave energy into or out of the periodic structure. The energy transfer may be repeaters. Quarter-wave transformers can be provided at one or more points on the periodic structure with the imaginary portion approximately equaling zero to transmit waves across one or more discontinuities. A terminator can be employed for cancellation of waves. The invention substantially eliminates reflections of the wave energy at the prime frequency by joints between sections of the periodic structure.
Drop impact upon micro- and nanostructured superhydrophobic surfaces.
Tsai, Peichun; Pacheco, Sergio; Pirat, Christophe; Lefferts, Leon; Lohse, Detlef
2009-10-20
We experimentally investigate drop impact dynamics onto different superhydrophobic surfaces, consisting of regular polymeric micropatterns and rough carbon nanofibers, with similar static contact angles. The main control parameters are the Weber number We and the roughness of the surface. At small We, i.e., small impact velocity, the impact evolutions are similar for both types of substrates, exhibiting Fakir state, complete bouncing, partial rebouncing, trapping of an air bubble, jetting, and sticky vibrating water balls. At large We, splashing impacts emerge forming several satellite droplets, which are more pronounced for the multiscale rough carbon nanofiber jungles. The results imply that the multiscale surface roughness at nanoscale plays a minor role in the impact events for small We less than or approximately equal 120 but an important one for large We greater than or approximately equal 120. Finally, we find the effect of ambient air pressure to be negligible in the explored parameter regime We less than or approximately equal 150.
Neiman, Andrea B; Ruppar, Todd; Ho, Michael; Garber, Larry; Weidle, Paul J; Hong, Yuling; George, Mary G; Thorpe, Phoebe G
2017-11-17
Adherence to prescribed medications is associated with improved clinical outcomes for chronic disease management and reduced mortality from chronic conditions (1). Conversely, nonadherence is associated with higher rates of hospital admissions, suboptimal health outcomes, increased morbidity and mortality, and increased health care costs (2). In the United States, 3.8 billion prescriptions are written annually (3). Approximately one in five new prescriptions are never filled, and among those filled, approximately 50% are taken incorrectly, particularly with regard to timing, dosage, frequency, and duration (4). Whereas rates of nonadherence across the United States have remained relatively stable, direct health care costs associated with nonadherence have grown to approximately $100-$300 billion of U.S. health care dollars spent annually (5,6). Improving medication adherence is a public health priority and could reduce the economic and health burdens of many diseases and chronic conditions (7).
Earth Observations taken by the Expedition 16 Crew
2007-12-29
ISS016-E-019239 (29 Dec. 2007) --- Dendi Caldera, Ethiopia is featured in this image photographed by an Expedition 16 crew member on the International Space Station. The Dendi Caldera is located on the Ethiopian Plateau, approximately 86 kilometers to the southwest of Addis Ababa. A caldera is a geological feature formed by the near-total eruption of magma from beneath a volcano, leading to collapse of the volcanic structure into the now-empty magma chamber. This collapse typically leaves a crater or depression where the volcano stood, and later volcanic activity can fill the caldera with younger lavas, ash, pyroclastic rocks, and sediments. While much of the volcanic rock in the area is comprised of basalt erupted as part of the opening of the East African Rift, more silica-rich rock types (characterized by minerals such as quartz and feldspar) are also present. According to scientists, the approximately 4 kilometers wide Dendi Caldera includes some of this silica-rich volcanic rock -- the rim of the caldera, visible in this view, is comprised mainly of poorly-consolidated ash erupted during the Tertiary Period (approximately 65 -- 2 million years ago). A notable feature of the Dendi Caldera is the presence of two shallow lakes formed within the central depression (center). This image also highlights a radial drainage pattern surrounding the remnants of the Dendi volcanic cone. Such patterns typically form around volcanoes, as rainfall has equal potential to move downslope on all sides of the cone and incise channels. No historical volcanic eruptions of Dendi are recorded, however the Wonchi Caldera 13 kilometers to the southwest (not shown) may have been active as "recently" as A.D. 550, say NASA scientists.
Effect of varying polyglutamate chain length on the structure and stability of ferricytochrome c.
Antalík, Marián; Bágel'ová, Jaroslava; Gazová, Zuzana; Musatov, Andrej; Fedunová, Diana
2003-03-21
The effect of varying polyglutamate chain length on local and global stability of horse heart ferricytochrome c was studied using scanning calorimetry and spectroscopy methods. Spectral data indicate that polyglutamate chain lengths equal or greater than eight monomer units significantly change the apparent pK(a) for the alkaline transition of cytochrome c. The change in pK(a) is comparable to the value when cytochrome c is complexed with cytochrome bc(1). Glutamate and diglutamate do not significantly alter the temperature transition for cleavage of the Met(80)-heme iron bond of cytochrome c. At low ionic strength, polyglutamates consisting of eight or more glutamate monomers increase midpoint of the temperature transition from 57.3+/-0.2 to 66.9+/-0.2 degrees C. On the other hand, the denaturation temperature of cytochrome c decreases from 85.2+/-0.2 to 68.8+/-0.2 degrees C in the presence of polyglutamates with number of glutamate monomers n >or approximately equal 8. The rate constant for cyanide binding to the heme iron of cytochrome c of cytochrome c-polyglutamate complex also decreases by approximately 42.5% with n>or approximately equal 8. The binding constant for the binding of octaglutamate (m.w. approximately 1000) to cyt c was found to be 1.15 x 10(5) M(-1) at pH 8.0 and low ionic strength. The results indicate that the polyglutamate (n>or approximately equal 8) is able to increase the stability of the methionine sulfur-heme iron bond of cytochrome c in spite of structural differences that weaken the overall stability of the cyt c at neutral and slightly alkaline pH.
Cutaneous water collection by a moisture-harvesting lizard, the thorny devil (Moloch horridus).
Comanns, Philipp; Withers, Philip C; Esser, Falk J; Baumgartner, Werner
2016-11-01
Moisture-harvesting lizards, such as the Australian thorny devil, Moloch horridus, have the remarkable ability to inhabit arid regions. Special skin structures, comprising a micro-structured surface with capillary channels in between imbricate overlapping scales, enable the lizard to collect water by capillarity and transport it to the mouth for ingestion. The ecological role of this mechanism is the acquisition of water from various possible sources such as rainfall, puddles, dew, condensation on the skin, or absorption from moist sand, and we evaluate here the potential of these various sources for water uptake by M. horridus The water volume required to fill the skin capillary system is 3.19% of body mass. Thorny devils standing in water can fill their capillary system and then drink from this water, at approximately 0.7 µl per jaw movement. Thorny devils standing on nearly saturated moist sand could only fill the capillary channels to 59% of their capacity, and did not drink. However, placing moist sand on skin replicas showed that the capillary channels could be filled from moist sand when assisted by gravity, suggesting that their field behaviour of shovelling moist sand onto the dorsal skin might fill the capillary channels and enable drinking. Condensation facilitated by thermal disequilibrium between a cool thorny devil and warm moist air provided skin capillary filling to approximately 0.22% of body weight, which was insufficient for drinking. Our results suggest that rain and moist sand seem to be ecologically likely water sources for M. horridus on a regular basis. © 2016. Published by The Company of Biologists Ltd.
Liquid gallium columns sheathed with carbon: Bulk synthesis and manipulation.
Zhan, Jinhua; Bando, Yoshio; Hu, Junqing; Golberg, Dmitri; Nakanishi, Haruyuki
2005-06-16
It is impossible to fabricate isolated gallium nanomaterials due to the low melting point of Ga (29.8 degrees C) and its high reactivity. We report the bulk synthesis of uniform liquid Ga columns encapsulated into carbon nanotubes through high-temperature chemical reaction between Ga and CH4. The diameter of filled Ga liquid columns is approximately 25 nm, and their length is up to several micrometers. The thickness of the carbon sheaths is approximately 6 nm. Simultaneous condensation of a Ga vapor and carbon clusters results in the generation of Ga-filled carbon nanotubes. A convergent 300 kV electron beam generated in a field emission high-resolution electron microscope is demonstrated to be a powerful tool for delicate manipulation of the liquid Ga nanocolumns: they can be gently joined, cut, and sealed within carbon nanotubes. The self-organization of a carbon sheath during the electron-beam irradiation is discussed. The electron-beam irradiation may also become a decent tool for Ga-filled carbon nanotube thermometer calibration.
Dye leakage of four root end filling materials: effects of blood contamination.
Torabinejad, M; Higa, R K; McKendry, D J; Pitt Ford, T R
1994-04-01
The purpose of this study was to compare the amount of dye leakage (in the presence versus absence of blood) in root end cavities filled with amalgam, Super EBA, IRM, and a mineral trioxide aggregate. After removing the anatomical crowns of 90 extracted human teeth, their roots were instrumented and obturated. Except for their apical 2 mm, the root surfaces were sealed with nail polish. After removal of the apical 2 to 3 mm of each root, a standardized root end cavity was prepared. Five root ends were filled with gutta-percha and no sealer, and another five root ends were filled with sticky wax. These served as positive and negative controls, respectively. The remaining 80 roots were divided into four equal groups and filled with the test materials. For each material, half of the root end cavities were dried prior to placing the filling material. The remaining half were filled after they were contaminated with blood. All 90 roots were then immediately placed in 1% methylene blue dye for 72 h. Finally, the roots were split and linear dye penetration was measured and statistically analyzed (analysis of variance). Presence or absence of blood had no significant effect on the amount of dye leakage. However, the results showed that there was a significant leakage difference between the root end filling materials (p < 0.0001). Mineral trioxide aggregate leaked significantly less than other materials tested with or without blood contamination of the root end cavities.
The partially filled viscous ring damper.
NASA Technical Reports Server (NTRS)
Alfriend, K. T.
1973-01-01
The problem of a spinning satellite with a partially filled viscous ring damper is investigated. It is shown that there are two distinct modes of motion, the nutation-synchronous mode and spin-synchronous mode. From an approximate solution of the equations of motion a time constant is obtained for each mode. From a consideration of the fluid dynamics several methods are developed for determining the damping constant.
Isolation and Characterization of Plasmodial and Babesial Antigens.
1979-11-10
and hygiene, 18: 836-859 pp. 952-958 (1966). (1969). 100. PRIOR. R. B. & KREIER, J. P. Experimental parasito - 74. KREIER, J. P. ET AL. Experimental...groups (Z test for equality of two proportions; 9). coat, although it obviously was in a relatively of the area filled by the matrix in the parasito
ERIC Educational Resources Information Center
Boone, Christine; Galloway, Melodie; Ruiz, Michael J.
2018-01-01
A fun activity is presented using singing wine glasses for introductory physics students. Students tune a white wine glass and a red wine glass to as many semitones as possible by filling the glasses with the appropriate amounts of water. A smart phone app is used to measure the frequencies of equal-temperament tones. Then plots of frequency…
The Pursuit of Equality: Retaining Women in Information Technology
ERIC Educational Resources Information Center
Ehlert, Teresa
2017-01-01
This qualitative study employed a three-iteration classical Delphi design to determine consensus regarding retention strategies of women in the IT industry. There is a call for the information technology (IT) industry to hire and retain more women. Retaining such a valuable educated source would help fill the ever-rising need for skilled workers…
Literary Education and Digital Learning: Methods and Technologies for Humanities Studies
ERIC Educational Resources Information Center
van Peer, Willie, Ed.; Zyngier, Sonia, Ed.; Viana, Vander, Ed.
2010-01-01
Today's popularization of modern technologies has allowed literature specialists to access an array of new opportunities in the digital medium, which have brought about an equal number of challenges and questions. This book provides insight into the most relevant issues in literary education and digital learning. This unique reference fills a gap…
30 CFR 250.456 - What safe practices must the drilling fluid program follow?
Code of Federal Regulations, 2012 CFR
2012-07-01
... circulate a volume of drilling fluid equal to the annular volume with the drill pipe just off-bottom. You... volume needed to fill the hole. Both sets of numbers must be posted near the driller's station. You must... industry-accepted practices and include density, viscosity, and gel strength; hydrogenion concentration...
30 CFR 250.456 - What safe practices must the drilling fluid program follow?
Code of Federal Regulations, 2014 CFR
2014-07-01
... circulate a volume of drilling fluid equal to the annular volume with the drill pipe just off-bottom. You... volume needed to fill the hole. Both sets of numbers must be posted near the driller's station. You must... industry-accepted practices and include density, viscosity, and gel strength; hydrogenion concentration...
30 CFR 250.456 - What safe practices must the drilling fluid program follow?
Code of Federal Regulations, 2013 CFR
2013-07-01
... circulate a volume of drilling fluid equal to the annular volume with the drill pipe just off-bottom. You... volume needed to fill the hole. Both sets of numbers must be posted near the driller's station. You must... industry-accepted practices and include density, viscosity, and gel strength; hydrogenion concentration...
Some Interesting Thermodynamics of the Thermos Flask
ERIC Educational Resources Information Center
Berger, Roland
2007-01-01
When opening a thermos flask filled with coffee, one often "hears" the equalization of the pressure difference that appears to be present between the air cavity inside the flask and the surrounding room atmosphere. Recently we discussed this phenomenon while drinking coffee and guessed about the direction of the gas stream accompanying the…
Neoliberal Education and Student Movements in Chile: Inequalities and Malaise
ERIC Educational Resources Information Center
Cabalin, Cristian
2012-01-01
This article examines the major consequences of the neoliberal education system implemented in Chile during the dictatorship of Augusto Pinochet and how two important student movements contested this structure. In 2006 and 2011, thousands of students filled the streets to demand better public education, more social justice and equal opportunities.…
NASA Technical Reports Server (NTRS)
Mather, John
2015-01-01
A: The cosmic microwave background (CMB) radiation fills the universe and travels in all directions. As we see it from here in satellite maps, it is about equally bright in all directions, and thats one of the main reasons we know its cosmic.
NASA Astrophysics Data System (ADS)
Youn, Sung-Won; Suzuki, Kenta; Hiroshima, Hiroshi
2018-06-01
A software program for modifying a mold design to obtain a uniform residual layer thickness (RLT) distribution has been developed and its validity was verified by UV-nanoimprint lithography (UV-NIL) simulation. First, the effects of granularity (G) on both residual layer uniformity and filling characteristics were characterized. For a constant complementary pattern depth and a granularity that was sufficiently larger than the minimum pattern width, filling time decreased with the decrease in granularity. For a pattern design with a wide density range and an irregular distribution, the choice of a small granularity was not always a good strategy since the etching depth required for a complementary pattern occasionally exceptionally increased with the decrease in granularity. On basis of the results obtained, the automated method was applied to a chip-scale pattern modification. Simulation results showed a marked improvement in residual layer thickness uniformity for a capacity-equalized (CE) mold. For the given conditions, the standard deviation of RLT decreased in the range from 1/3 to 1/5 in accordance with pattern designs.
Venturi, M
2006-07-01
To evaluate the quality of root canal filling when comparing two warm gutta-percha filling techniques in vivo. Human teeth were randomly divided into two equal groups, with 30 canals each. The root canals were shaped by hand and ProFile 0.04 rotary instruments to size 20-40 at the end-point and then filled with gutta-percha cones and AH-Plus. In group A, a traditional warm vertical compaction technique was performed using the Touch'n Heat, and back-filling with the Obtura II. In group B, a modified warm vertical compaction technique was used: small amounts of gutta-percha were removed, and the remaining most apical 3 mm were compacted with a 1 mm movement; then thermomechanical back-filling was performed. The teeth were extracted, stored in dye, cleared, and the distance between the apex and apical limit of the filling, linear dye penetration, and voids were measured from the buccal, lingual, mesial and distal perspective. The homogeneity of variance and means was verified using Levene's test and t-test. ANOVA and Dunnett post hoc test were used to establish the significance and to analyse the effects through multiple comparisons. Compared with the specimens of group A, the specimens of group B exhibited less mean linear dye penetration (P < 0.05), smaller void length (P < or = 0.05) and maximal width (P < or = 0.05) when examined in all four views, and a more precise filling when viewed from the buccal aspect (P < 0.05). The modified warm vertical compaction technique with apical back-filling produced a more effective and precise three-dimensional filling.
NASA Astrophysics Data System (ADS)
Zav'yalov, A. S.
2018-04-01
A variant of the method of partial waveguide filling is considered in which a sample is put into a waveguide through holes in wide waveguide walls at the distance equal to a quarter of the wavelength in the waveguide from a short-circuiter, and the total input impedance of the sample in the waveguide is directly measured. The equivalent circuit of the sample is found both without and with account of the hole. It is demonstrated that consideration of the edge effect makes it possible to obtain more exact values of the dielectric permittivity.
Energetic electrons in impulsive solar flares
NASA Technical Reports Server (NTRS)
Batchelor, D. A.
1984-01-01
A new analysis was made of a thermal flare model proposed by Brown, Melrose, and Spicer (1979) and Smith and Lilliequist (1979). They assumed the source of impulsive hard X-rays to be a plasma at a temperature of order 10 to the 8th power K, initially located at the apex of a coronal arch, and confined by ion-acoustic turbulence in a collisionless conduction front. Such a source would expand at approximately the ion-sound speed, C sub S = square root of (k T sub e/m sub i), until it filled the arch. Brown, Melrose, and Spicer and Smith and Brown (1980) argued that the source assumed in this model would not explain the simultaneous impulsive microwave emission. In contrast, the new results presented herein suggest that this model leads to the development of a quasi-Maxwellian distribution of electrons that explains both the hard X-ray and microwave emissions. This implies that the source sizes can be determined from observations of the optically-thick portions of microwave spectra and the temperatures obtained from associated hard X-ray observations. In this model, the burst emission would rise to a maximum in a time, t sub r, approximately equal to L/c sub s, where L is the half-length of the arch. New observations of these impulsive flare emissions were analyzed herein to test this prediction of the model. Observations made with the Solar Maximum Mission spacecraft and the Bern Radio Observatory are in good agreement with the model.
NASA Astrophysics Data System (ADS)
MacPhee, A. G.; Smalyuk, V. A.; Landen, O. L.; Weber, C. R.; Robey, H. F.; Alfonso, E. L.; Biener, J.; Bunn, T.; Crippen, J. W.; Farrell, M.; Felker, S.; Field, J. E.; Hsing, W. W.; Kong, C.; Milovich, J.; Moore, A.; Nikroo, A.; Rice, N.; Stadermann, M.; Wild, C.
2018-05-01
We report a reduced X-ray shadow imprint of hydrodynamic instabilities on the high-density carbon ablator surface of inertial confinement fusion (ICF) capsules using a reduced diameter fuel fill tube on the National Ignition Facility (NIF). The perturbation seed mass from hydrodynamic instabilities was reduced by approximately an order of magnitude by reducing both the diameter and wall thickness of the fill tube by ˜2×, consistent with analytical estimates. This work demonstrates a successful mitigation strategy for engineered features for ICF implosions on the NIF.
Hanson, R.T.; McLean, J.S.; Miller, Ryan S.
1994-01-01
The bolson-fill aquifer, the major water-yielding unit in the Mimbres Basin, southwestern New Mexico, ranges in thickness from 0 to about 3,700 feet. Recharge to the bolson-fill aquifer occurs by infiltration of ephemeral streams that cross the basin margin, infiltration from precipitation and streamflow, ground-water underflow from adjacent basins, and infiltration of springflow from adjacent bedrock units within the basin. Ground water generally flows southward from the northern highland areas of the basin. Ground-water discharge consists of pumpage from wells, transpiration by plants, outflow to playas and springs in the Los Muertos Basin in Mexico, discharge to the Mimbres River, and ground-water flow to the Mesilla Basin near Mason Draw. Before 1910, ground-water recharge and discharge were approximately equal; by 1975, however, about 75 percent of the 146,000 acre-feet withdrawn annually was ground water, most of it from aquifer storage. The transmissivity of the bolson-fill aquifer determined from aquifer tests and specific-capacity data ranges from 10 to 50,000 feet squared per day. Hydraulic conductivity, calculated from saturated thickness and transmissivity, ranges from 0.03 to 800 feet per day, with median values of about 18 feet per day in the Deming area and 6 feet per day elsewhere. Reported storage-coefficient values representing confined parts of the aquifer range from 0.00036 to 0.0036, and those representing unconfined parts of the aquifer range from 0.02 to 0.24. Water quality in the north and central parts of the Mimbres Basin is suitable for most uses. Due to its large salinity and alkalinity, some of the ground water in the south and southeastern areas of the bolson-fill aquifer may not be suitable for irrigation or domestic use. A preliminary two-dimensional digital model was constructed to evaluate ground-water flow in the bolson-fill aquifer. The model was divided into zones of uniform hydraulic conductivity corresponding to the major structural elements of the basin. For simulation purposes, hydraulic conductivity in the central part of the basin ranged from 2.2 to 4.4 feet per day, whereas locally along the edges of the aquifer less certain values ranged from 0.003 to 62 feet per day Analysis of the results of this predevelopment model indicated that use of the mountain-front recharge method overestimates total recharge and that evapotranspiration is substantial. The simulated total inflow was about 55 percent of that estimated in a water budget for the Mimbres Basin.Ground-water development between 1930 and 1985 was simulated using storage-coefficient values of 0.01 and 0.02 for the Gila Conglomerate, 0.04 to 0.17 for bolson-fill deposits, and 0.001 for bolson fill capped with lacustrine clay. The simulated transient water budget indicated that most of the water pumped by 1985 came from storage, and lesser but substantial amounts came from reductions in evapotranspiration.
NASA Astrophysics Data System (ADS)
Szu, Harold H.
1999-03-01
The early vision principle of redundancy reduction of 108 sensor excitations is understandable from computer vision viewpoint toward sparse edge maps. It is only recently derived using a truly unsupervised learning paradigm of artificial neural networks (ANN). In fact, the biological vision, Hubel- Wiesel edge maps, is reproduced seeking the underlying independent components analyses (ICA) among 102 image samples by maximizing the ANN output entropy (partial)H(V)/(partial)[W] equals (partial)[W]/(partial)t. When a pair of newborn eyes or ears meet the bustling and hustling world without supervision, they seek ICA by comparing 2 sensory measurements (x1(t), x2(t))T equalsV X(t). Assuming a linear and instantaneous mixture model of the external world X(t) equals [A] S(t), where both the mixing matrix ([A] equalsV [a1, a2] of ICA vectors and the source percentages (s1(t), s2(t))T equalsV S(t) are unknown, we seek the independent sources approximately equals [I] where the approximated sign indicates that higher order statistics (HOS) may not be trivial. Without a teacher, the ANN weight matrix [W] equalsV [w1, w2] adjusts the outputs V(t) equals tanh([W]X(t)) approximately equals [W]X(t) until no desired outputs except the (Gaussian) 'garbage' (neither YES '1' nor NO '-1' but at linear may-be range 'origin 0') defined by Gaussian covariance at the fixed point (partial)E/(partial)wi equals 0 resulted in an exact Toplitz matrix inversion for a stationary covariance assumption. We generalize AR by a nonlinear output vi(t+1) equals tanh(wiTX(t)) within E equals <[x(t+1) - vi(t+1)]2>, and the gradient descent (partial)E/(partial)wi equals - (partial)wi/(partial)t. Further generalization is possible because of specific image/speech having a specific histogram whose gray scale statistics departs from that of Gaussian random variable and can be measured by the fourth order cumulant, Kurtosis K(vi) equals
The CFL condition for spectral approximations to hyperbolic initial-boundary value problems
NASA Technical Reports Server (NTRS)
Gottlieb, David; Tadmor, Eitan
1991-01-01
The stability of spectral approximations to scalar hyperbolic initial-boundary value problems with variable coefficients are studied. Time is discretized by explicit multi-level or Runge-Kutta methods of order less than or equal to 3 (forward Euler time differencing is included), and spatial discretizations are studied by spectral and pseudospectral approximations associated with the general family of Jacobi polynomials. It is proved that these fully explicit spectral approximations are stable provided their time-step, delta t, is restricted by the CFL-like condition, delta t less than Const. N(exp-2), where N equals the spatial number of degrees of freedom. We give two independent proofs of this result, depending on two different choices of approximate L(exp 2)-weighted norms. In both approaches, the proofs hinge on a certain inverse inequality interesting for its own sake. The result confirms the commonly held belief that the above CFL stability restriction, which is extensively used in practical implementations, guarantees the stability (and hence the convergence) of fully-explicit spectral approximations in the nonperiodic case.
The CFL condition for spectral approximations to hyperbolic initial-boundary value problems
NASA Technical Reports Server (NTRS)
Gottlieb, David; Tadmor, Eitan
1990-01-01
The stability of spectral approximations to scalar hyperbolic initial-boundary value problems with variable coefficients are studied. Time is discretized by explicit multi-level or Runge-Kutta methods of order less than or equal to 3 (forward Euler time differencing is included), and spatial discretizations are studied by spectral and pseudospectral approximations associated with the general family of Jacobi polynomials. It is proved that these fully explicit spectral approximations are stable provided their time-step, delta t, is restricted by the CFL-like condition, delta t less than Const. N(exp-2), where N equals the spatial number of degrees of freedom. We give two independent proofs of this result, depending on two different choices of approximate L(exp 2)-weighted norms. In both approaches, the proofs hinge on a certain inverse inequality interesting for its own sake. The result confirms the commonly held belief that the above CFL stability restriction, which is extensively used in practical implementations, guarantees the stability (and hence the convergence) of fully-explicit spectral approximations in the nonperiodic case.
A Unified Theory of Impact Crises and Mass Extinctions: Quantitative Tests
NASA Technical Reports Server (NTRS)
Rampino, Michael R.; Haggerty, Bruce M.; Pagano, Thomas C.
1997-01-01
Several quantitative tests of a general hypothesis linking impacts of large asteroids and comets with mass extinctions of life are possible based on astronomical data, impact dynamics, and geological information. The waiting of large-body impacts on the Earth derive from the flux of Earth-crossing asteroids and comets, and the estimated size of impacts capable of causing large-scale environmental disasters, predict that impacts of objects greater than or equal to 5 km in diameter (greater than or equal to 10 (exp 7) Mt TNT equivalent) could be sufficient to explain the record of approximately 25 extinction pulses in the last 540 Myr, with the 5 recorded major mass extinctions related to impacts of the largest objects of greater than or equal to 10 km in diameter (greater than or equal to 10(exp 8) Mt Events). Smaller impacts (approximately 10 (exp 6) Mt), with significant regional environmental effects, could be responsible for the lesser boundaries in the geologic record.
Development of a 3D Filling Model of Low-Pressure Die-Cast Aluminum Alloy Wheels
NASA Astrophysics Data System (ADS)
Duan, Jianglan; Maijer, Daan; Cockcroft, Steve; Reilly, Carl
2013-12-01
A two-phase computational fluid dynamics model of the low-pressure die-cast process for the production of A356 aluminum alloy wheels has been developed to predict the flow conditions during die filling. The filling model represents a 36-deg section of a production wheel, and was developed within the commercial finite-volume package, ANSYS CFX, assuming isothermal conditions. To fully understand the behavior of the free surface, a novel technique was developed to approximate the vent resistances as they impact on the development of a backpressure within the die cavity. The filling model was first validated against experimental data, and then was used to investigate the effects of venting conditions and pressure curves during die filling. It was found that vent resistance and vent location strongly affected die filling time, free surface topography, and air entrainment for a given pressure fill-curve. With regard to the pressure curve, the model revealed a strong relation between the pressure curve and the flow behavior in the hub, which is an area prone to defect formation.
Faint blue counts from formation of dwarf galaxies at z approximately equals 1
NASA Technical Reports Server (NTRS)
Babul, Arif; Rees, Martin J.
1993-01-01
The nature of faint blue objects (FBO's) has been a source of much speculation since their detection in deep CCD images of the sky. Their high surface density argues against them being progenitors of present-day bright galaxies and since they are only weakly clustered on small scales, they cannot be entities that merged together to form present-day galaxies. Babul & Rees (1992) have suggested that the observed faint blue counts may be due to dwarf elliptical galaxies undergoing their initial starburst at z is approximately equal to 1. In generic hierarchical clustering scenarios, however, dwarf galaxy halos (M is approximately 10(exp 9) solar mass) are expected to form at an earlier epoch; for example, typical 10(exp 9) solar mass halos will virialize at z is approximately equal to 2.3 if the power-spectrum for the density fluctuations is that of the standard b = 2 cold dark matter (CDM) model. Under 'ordinary conditions' the gas would rapidly cool, collect in the cores, and undergo star-formation. Conditions at high redshifts are far from 'ordinary'. The intense UV background will prevent the gas in the dwarf halos from cooling, the halos being released from their suspended state only when the UV flux has diminished sufficiently.
Extreme ultraviolet explorer satellite observation of Jupiter's Io plasma torus
NASA Technical Reports Server (NTRS)
Hall, D. T; Gladstone, G. R.; Moos, H. W.; Bagenal, F.; Clarke, J. T.; Feldman, P. D.; Mcgrath, M. A.; Schneider, N. M.; Shemansky, D. E.; Strobel, D. F.
1994-01-01
We present the first Extreme Ultraviolet Explorer (EUVE) satellite observation of the Jupiter system, obtained during the 2 day period 1993 March 30 through April 1, which shows a rich emission-line spectrum from the Io plasma torus spanning wavelengths 370 to 735 A. The emission features correspond primarily to known multiplets of oxygen and sulfur ions, but a blended feature near 372 A is a plausible Na II transition. The summed detected energy flux of (7.2 +/- 0.2) x 10(exp -11) ergs/sq cm(s) corresponds to a radiated power of approximately equal to 4 x 10(exp 11) W in this spectral range. All ansa emissions show a distinct dawn-dusk brightness asymmetry and the measured dusk/dawn ratio of the bright S III lambda-680 feature is 2.3 +/- 0.3, significantly larger than the ratio measured by the Voyager spacecraft ultraviolet (UV) instruments. A preliminary estimate of ion partitioning indicates that the oxygen/sulfur ion ratio is approximately equal to 2, compared to the value approximately equal to 1.3 measured by Voyager, and that (Na(+))/(e) greater than 0.01.
Correlations among the Optical Properties of Cirrus-Cloud Particles: Microphysical Interpretation
NASA Technical Reports Server (NTRS)
Reichardt, J.; Reichardt, S.; Hess, M.; McGee, T. J.; Bhartia, P. K. (Technical Monitor)
2002-01-01
Cirrus measurements obtained with a ground-based polarization Raman lidar at 67.9 deg N in January 1997 reveal a strong positive correlation between the particle optical properties, specifically depolarization ratio delta(sub par) and extinction- to-backscatter (lidar) ratio S, for delta(sub par) less than approximately 40%, and an anti-correlation for delta(sub par) greater than approximately 40%. Over the length of the measurements the particle properties vary systematically. Initially, delta (sub par) approximately equals 60% and S approximately equals 10sr are observed. Then, with decreasing delta(sub par), S first increases to approximately 27sr (delta(sub par) approximately equals 40%) before decreasing to values around 10sr again (delta(sub par) approximately equals 20%). The analysis of lidar humidity and radiosonde temperature data shows that the measured optical properties stem from scattering by dry solid ice particles, while scattering by supercooled droplets, or by wetted or subliming ice particles can be excluded. For the microphysical interpretation of the lidar measurements, ray-tracing computations of particle scattering properties have been used. The comparison with the theoretical data suggests that the observed cirrus data can be interpreted in terms of size, shape, and, under the assumption that the lidar measurements of consecutive cloud segments can be mapped on the temporal development of a single cloud parcel moving along its trajectory, growth of the cirrus particles: Near the cloud top in the early stage of cirrus development, light scattering by nearly isometric particles that have the optical characteristics of hexagonal columns (short, column-like particles) is dominant. Over time the ice particles grow, and as the cloud base height extends to lower altitudes characterized by warmer temperatures they become morphologically diverse. For large S and depolarization values of approximately 40%, the scattering contributions of column- and plate-like particles are roughly the same. In the lower ranges of the cirrus clouds, light scattering is predominantly by plate-like ice particles. This interpretation assumes random orientation of the cirrus particles. Simulations with a simple model suggest, however, that the positive correlation between S and delta(sub par) which is observed for depolarization ratios less than 40% mainly at low cloud altitudes, can be alternatively explained by horizontal alignment of a fraction of the cirrus particle population.
Gammie, A; Abrams, P; Bevan, W; Ellis-Jones, J; Gray, J; Hassine, A; Williams, J; Hashim, H
2016-11-01
This study aimed to evaluate whether the pressure readings obtained from air-filled catheters (AFCs) are the same as the readings from simultaneously inserted water-filled catheters (WFCs). It also aimed to make any possible recommendations for the use of AFCs to conform to International Continence Society (ICS) Good Urodynamic Practices (GUP). Female patients undergoing urodynamic studies in a single center had water-filled and air-filled catheters simultaneously measuring abdominal and intravesical pressure during filling with saline and during voiding. The pressures recorded by each system at each event during the test were compared using paired t-test and Bland-Altman analyses. 62 patients were recruited, of whom 51 had pressures that could be compared during filling, and 23 during voiding. On average, the pressures measured by the two systems were not significantly different during filling and at maximum flow, but the values for a given patient were found to differ by up to 10 cmH 2 O. This study shows that AFCs and WFCs cannot be assumed to register equal values of pressure. It has further shown that even when the p det readings are compared with their value at the start of a test, a divergence of values of up to 10 cmH 2 O remains. If AFCs are used, care must be taken to compensate for any p det variations that occur during patient movement. Before AFCs are adopted, new normal values for resting pressures need to be developed to allow good quality AFC pressure readings to be made. Neurourol. Urodynam. 35:926-933, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.
ERIC Educational Resources Information Center
Randell, Stacy T.; Smith, Amy E.; Steinman, Bernard A.
2015-01-01
American youth do not have equal access to academic success and life achievements. In particular, low-income male students of color are disproportionately failing in school, filling prisons, and enduring the consequences of low social capital and poor investment in their futures. Unfortunately, many young people cope with poverty and life in…
49 CFR 393.67 - Liquid fuel tanks.
Code of Federal Regulations, 2010 CFR
2010-10-01
... section. The rules in this section apply to tanks containing or supplying fuel for the operation of... leak more than a total of one ounce by weight of fuel per minute in any position the tank assumes...) Drop test—(i) Procedure. Fill the tank with a quantity of water having a weight equal to the weight of...
Pacific Youth and Shifting Thresholds: Understanding Teen Dating Violence in Hawai'i
ERIC Educational Resources Information Center
Baker, Charlene K.; Helm, Susana
2010-01-01
The high prevalence of teen dating violence (TDV) nationally suggests that it is a public health problem in need of intervention. However, there is limited information about what constitutes TDV in the eyes of teens. Equally limited is an understanding of these parameters among diverse cultures. To fill these gaps, the current study conducted…
30 CFR 250.456 - What safe practices must the drilling fluid program follow?
Code of Federal Regulations, 2011 CFR
2011-07-01
... fluid. You must circulate a volume of drilling fluid equal to the annular volume with the drill pipe... fluid volume needed to fill the hole. Both sets of numbers must be posted near the driller's station... warrant. Your tests must conform to industry-accepted practices and include density, viscosity, and gel...
Material and Optical Densities
ERIC Educational Resources Information Center
Gluck, Paul
2007-01-01
The bending of a laser beam in a medium with a density and refractive index gradient in the same direction has been described previously. When a transparent container is half filled with a salt or sugar solution and an equal amount of water is floated on top of it, then diffusion will create a concentration gradient from top to bottom. A laser…
Visualization of Sound Waves Using Regularly Spaced Soap Films
ERIC Educational Resources Information Center
Elias, F.; Hutzler, S.; Ferreira, M. S.
2007-01-01
We describe a novel demonstration experiment for the visualization and measurement of standing sound waves in a tube. The tube is filled with equally spaced soap films whose thickness varies in response to the amplitude of the sound wave. The thickness variations are made visible based on optical interference. The distance between two antinodes is…
The Possible Impact of Problem-Solving Method of Instruction on Exceptional Students' Creativity
ERIC Educational Resources Information Center
Fard, Adnan Eshrati; Bahador, Ali; Moghadam, Mahsa Nazemi; Rajabi, Hooman; Moradi, Alinoor Noor
2014-01-01
The current study aimed at investigating the possible impact of the problem-solving method of instruction on the exceptional students' creativity. A sample of 50 male exceptional (Mild intellectual disability) students studying in the third grade of junior high school was chosen and divided into two equal groups. Both groups filled out the…
Feeding and Feedback in the Powerful Radio Galaxy 3C 120
NASA Technical Reports Server (NTRS)
Tombesi, F.; Mushotzky, R. F.; Reynolds, C. S.; Kallman, T.; Reeves, J. N.; Braito, V.; Ueda, Y.; Leutenegger, M. A.; Williams, B. J.; Stawarz, L.;
2017-01-01
We present a spectral analysis of a 200-kilosecond observation of the broad-line radio galaxy 3C 120, performed with the high-energy transmission grating spectrometer on board the Chandra X-Ray Observatory. We find (i) a neutral absorption component intrinsic to the source with a column density of log N (sub H) equals 20.67 plus or minus 0.05 square centimeters; (ii) no evidence for a warm absorber (WA) with an upper limit on the column density of just log N (sub H) less than 19.7 square centimeters, assuming the typical ionization parameter log xi approximately equal to 2.5 ergs per second per centimeter; the WA may instead be replaced by (iii) a hot emitting gas with a temperature kT approximately equal to 0.7 kiloelectronvolts observed as soft X-ray emission from ionized Fe L-shell lines, which may originate from a kiloparsec-scale shocked bubble inflated by the active galactic nucleus (AGN) wind or jet with a shock velocity of about 1000 kilometers per second determined by the emission line width; (iv) a neutral Fe K alpha line and accompanying emission lines indicative of a Compton-thick cold reflector with a low reflection fraction R approximately equal to 0.2, suggesting a large opening angle of the torus; (v) a highly ionized Fe XXV emission feature indicative of photoionized gas with an ionization parameter log xi equal to 3.75 (sup plus 0.38) (sub minus 0.27) ergs per second per centimeter and a column density of log N (sub H) greater than 22 square centimeters localized within approximately 2 pc from the X-ray source; and (vi) possible signatures of a highly ionized disk wind. Together with previous evidence for intense molecular line emission, these results indicate that 3C 120 is likely a late-state merger undergoing strong AGN feedback.
Ion beam and dual ion beam sputter deposition of tantalum oxide films
NASA Astrophysics Data System (ADS)
Cevro, Mirza; Carter, George
1994-11-01
Ion beam sputter deposition (IBS) and dual ion beam sputter deposition (DIBS) of tantalum oxide films was investigated at room temperature and compared with similar films prepared by e-gun deposition. Optical properties ie refractive index and extinction coefficient of IBS films were determined in the 250 - 1100 nm range by transmission spectrophotometry and at (lambda) equals 632.8 nm by ellipsometry. They were found to be mainly sensitive to the partial pressure of oxygen used as a reactive gas in the deposition process. The maximum value of the refractive index of IBS deposited tantalum oxide films was n equals 2.15 at (lambda) equals 550 nm and the extinction coefficient of order k equals 2 X 10-4. Films deposited by e-gun deposition had refractive index n equals 2.06 at (lambda) equals 550 nm. Films deposited using DIBS ie deposition assisted by low energy Ar and O2 ions (Ea equals 0 - 300 eV) and low current density (Ji equals 0 - 40 (mu) A/cm2) showed no improvement in the optical properties of the films. Preferential sputtering occurred at Ea(Ar) equals 300 eV and Ji equals 20 (mu) A/cm2 and slightly oxygen deficient films were formed. Different bonding states in the tantalum-oxide films were determined by x-ray spectroscopy while composition of the film and contaminants were determined by Rutherford scattering spectroscopy. Tantalum oxide films formed by IBS contained relatively high Ar content (approximately equals 2.5%) originating from the reflected argon neutrals from the sputtering target while assisted deposition slightly increased the Ar content. Stress in the IBS deposited films was measured by the bending technique. IBS deposited films showed compressive stress with a typical value of s equals 3.2 X 109 dyn/cm2. Films deposited by concurrent ion bombardment showed an increase in the stress as a function of applied current density. The maximum was s approximately equals 5.6 X 109 dyn/cm2 for Ea equals 300 eV and Ji equals 35 (mu) A/cm2. All deposited films were amorphous as measured by the x-ray diffraction method.
Fu, Chi-Yung; Petrich, Loren I.
1997-01-01
An image is compressed by identifying edge pixels of the image; creating a filled edge array of pixels each of the pixels in the filled edge array which corresponds to an edge pixel having a value equal to the value of a pixel of the image array selected in response to the edge pixel, and each of the pixels in the filled edge array which does not correspond to an edge pixel having a value which is a weighted average of the values of surrounding pixels in the filled edge array which do correspond to edge pixels; and subtracting the filled edge array from the image array to create a difference array. The edge file and the difference array are then separately compressed and transmitted or stored. The original image is later reconstructed by creating a preliminary array in response to the received edge file, and adding the preliminary array to the received difference array. Filling is accomplished by solving Laplace's equation using a multi-grid technique. Contour and difference file coding techniques also are described. The techniques can be used in a method for processing a plurality of images by selecting a respective compression approach for each image, compressing each of the images according to the compression approach selected, and transmitting each of the images as compressed, in correspondence with an indication of the approach selected for the image.
Fu, C.Y.; Petrich, L.I.
1997-03-25
An image is compressed by identifying edge pixels of the image; creating a filled edge array of pixels each of the pixels in the filled edge array which corresponds to an edge pixel having a value equal to the value of a pixel of the image array selected in response to the edge pixel, and each of the pixels in the filled edge array which does not correspond to an edge pixel having a value which is a weighted average of the values of surrounding pixels in the filled edge array which do correspond to edge pixels; and subtracting the filled edge array from the image array to create a difference array. The edge file and the difference array are then separately compressed and transmitted or stored. The original image is later reconstructed by creating a preliminary array in response to the received edge file, and adding the preliminary array to the received difference array. Filling is accomplished by solving Laplace`s equation using a multi-grid technique. Contour and difference file coding techniques also are described. The techniques can be used in a method for processing a plurality of images by selecting a respective compression approach for each image, compressing each of the images according to the compression approach selected, and transmitting each of the images as compressed, in correspondence with an indication of the approach selected for the image. 16 figs.
NASA Astrophysics Data System (ADS)
Liu, Yong Jun; Li, Chao; Zhou, When Jun
2018-06-01
This paper presents some numerical simulation results of tensile properties of reinforcing bars spliced by grout-filled coupling sleeves under fire conditions to identify the effect of load ratio on fire resistance time of spliced reinforcing bars, which provide a useful base for predicting structural behaviors of pre-cast reinforced concrete buildings in fires. A spliced rebar system investigated in this paper consists of two equal-diameter steel reinforcing bars with 25mm diameter and a straight coupling sleeve with 50mm outer and 45mm inner diameters. As a result, the thickness of grout between steel bars and sleeves are 20mm. Firstly, the temperature distributions in steel bars connected by grout- filled coupling sleeves exposed to ISO 834 standard fire were calculated utilizing finite element analysis software ANSYS. Secondly, the stress changes in heated steel bars connected by grout-filled coupling sleeves under different constant tensile loads were calculated step by step until the rebar system failed due to fire. Thus, the fire resistant time of rebar spliced by grout-filled coupling sleeves under different axial tensile loads can be determined, further, the relationship between fire resistance time and axial tensile loads ratio can could be obtained. Finally, the fire resistant times versus axial tensile load ratios curve of grout-filled splice sleeve rebars exposed to ISO 834 standard fire is presented.
Fisher, D; Markitziu, A; Fishel, D; Brayer, L
1984-07-01
Fifty-four paired, approximal amalgam fillings, extended (E) versus unextended (NE) were placed in forty-three patients and followed up to 4 years. Yearly measurements between the alveolar crest and (a) the apical margin of the fillings (E, NE), and (b) the cemento-enamel junction of the control group, were performed using bite-wing radiographs joined to a translucent grid magnified ten-fold. The rate of alveolar crest resorption was similar for the control (C) and the unextended filling (NE) and reached 0.45 mm after 4 years of follow-up. The resorption of the alveolar crest under the extended (E) filling was significantly higher and reached 0.80 mm after 4 years (P less than 0.001).
High-Temperature Crystal-Growth Cartridge Tubes Made by VPS
NASA Technical Reports Server (NTRS)
Holmes, Richard; O'Dell, Scott; McKechnie, Timothy; Power, Christopher
2008-01-01
Cartridge tubes for use in a crystal growth furnace at temperatures as high as 1,600 deg. C have been fabricated by vacuum plasma spraying (VPS). These cartridges consist mainly of an alloy of 60 weight percent molybdenum with 40 weight percent rhenium, made from molybdenum powder coated with rhenium. This alloy was selected because of its high melting temperature (approximately equal.2,550 C) and because of its excellent ductility at room temperature. These cartridges are intended to supplant tungsten/nickel-alloy cartridges, which cannot be used at temperatures above approximately equal 1,300 C.
Io Shown in Lambertian Equal Area Projection and in Approximately Natural Color
1998-06-04
NASA's Voyager 1 computer color mosaics, shown in approximately natural color and in Lambertian equal-area projections, show the Eastern (left) and Western (right) hemispheres of Io. This innermost of Jupiter's 4 major satellites is the most volcanically active object in the solar system. Io is 2263 mi (3640 km) in diameter, making it a little bigger than Earth's moon. Almost all the features visible here have volcanic origins, including several calderas and eruption plumes that were active at the time of the Voyager 1 encounter. http://photojournal.jpl.nasa.gov/catalog/PIA00318
Faulhammer, E; Llusa, M; Wahl, P R; Paudel, A; Lawrence, S; Biserni, S; Calzolari, V; Khinast, J G
2016-01-01
The objectives of this study were to develop a predictive statistical model for low-fill-weight capsule filling of inhalation products with dosator nozzles via the quality by design (QbD) approach and based on that to create refined models that include quadratic terms for significant parameters. Various controllable process parameters and uncontrolled material attributes of 12 powders were initially screened using a linear model with partial least square (PLS) regression to determine their effect on the critical quality attributes (CQA; fill weight and weight variability). After identifying critical material attributes (CMAs) and critical process parameters (CPPs) that influenced the CQA, model refinement was performed to study if interactions or quadratic terms influence the model. Based on the assessment of the effects of the CPPs and CMAs on fill weight and weight variability for low-fill-weight inhalation products, we developed an excellent linear predictive model for fill weight (R(2 )= 0.96, Q(2 )= 0.96 for powders with good flow properties and R(2 )= 0.94, Q(2 )= 0.93 for cohesive powders) and a model that provides a good approximation of the fill weight variability for each powder group. We validated the model, established a design space for the performance of different types of inhalation grade lactose on low-fill weight capsule filling and successfully used the CMAs and CPPs to predict fill weight of powders that were not included in the development set.
Spatially Complete Global Surface Albedos Derived from Terra/MODIS Data
NASA Technical Reports Server (NTRS)
King, Michael D.; Moody, Eric G.; Platnick, Steven; Schaaf, Crystal B.
2004-01-01
Spectral land surface albedo is an important parameter for describing the radiative properties of the Earth. Accordingly it reflects the consequences of natural and human interactions, such as anthropogenic, meteorological, and phenological effects, on global and local climatological trends. Consequently, albedos are integral parts in a variety of research areas, such as general circulation models (GCMs), energy balance studies, modeling of land use and land use change, and biophysical, oceanographic, and meteorological studies. Recent production of land surface anisotropy, diffuse bihemispherical (white-sky) albedo and direct beam directional hemispherical (black-sky) albedo from observations acquired by the MODIS instruments aboard NASA s Terra and Aqua satellite platforms have provided researchers with unprecedented spatial, spectral, and temporal information on the land surface's radiative characteristics. Cloud cover, which cutails retrievals, and the presence of ephemeral and seasonal snow limit the snow-free data to approximately half the global land surfaces on an annual equal-angle basis. This precludes the MOD43B3 albedo products from being used in some remote sensing and ground-based applications, climate models, and global change research projects. An ecosystem-dependent temporal interpolation technique is described that has been developed to fill missing or seasonally snow-covered data in the official MOD43B3 albedo product. The method imposes pixel-level and local regional ecosystem-dependent phenological behavior onto retrieved pixel temporal data in such a way as to maintain pixel-level spatial and spectral detail and integrity. The phenological curves are derived from statistics based on the MODIS MOD12Q1 IGBP land cover classification product geolocated with the MOD43B3 data. The resulting snow-free value-added products provide the scientific community with spatially and temporally complete global white- and black-sky surface albedo maps and statistics. These products are stored on 1'(approximately 10 km) and coarser resolution equal-angle grids, and are computed for the first seven MODIS wavelengths, ranging from 0.47 through 2.1 microns, and for three broadband wavelengths, 0.3-0.7,0.3-5.0 and 0.7-5.0 microns.
Gender equality and women empowerment.
Dargan, R
1996-01-01
This article lists 11 suggestions for empowering women that the government of India should take, if it has a sincere commitment to gender equality and women's empowerment grounded in social change and not just rhetoric: 1) education should be made compulsory for all female children and places held on a 50/50 basis in all technical institutions; 2) a uniform civil code should be adopted for all citizens regardless of cast, creed, and religion; 3) women should have an equal right to own property and receive inheritance; 4) the National Women's Commission should be enlarged, representative of diversity, and effective in making policy decisions related to welfare, education, recruitment, and promotion; 5) a State Women's Commission should be established with affiliates at the block, district, and division levels; 6) the National and State Women's Commission should be established as a Statutory Body with binding decisions mandating government action; 7) the National and State Women's Commissions should have transparent functions, be regulatory, and offer workshops and seminars for women; 8) state governments should not interfere in the functions of National and State Women's Commissions; 9) women should fill 50% of all Center and State government service posts and concessions should be made on minimum academic qualifications and completed years of service, until all positions are filled; 10) 50% of the seats of Parliament should be reserved for women in both the State Legislature, Council of Ministry Boards, Corporations, Committees, and Commissions; and 11) the Constitution should provide for women judges in courts of law.
Liquid metal boiling inception
NASA Technical Reports Server (NTRS)
Sabin, C. M.; Poppendiek, H. F.; Mouritzen, G.; Meckel, P. T.; Cloakey, J. E.
1972-01-01
An experimental study of the inception of boiling in potassium in forced convection is reported. The boiler consisted of a 0.19-inch inside diameter, niobium-1% zirconium boiler tube approximately six feet long. Heating was accomplished by direct electrical tube wall conduction. Experiments were performed with both all-liquid fill and two-phase fill startup sequences and with a range of flow rates, saturation temperatures, inert gas levels, and fill liquid temperatures. Superheat of the liquid above the equilibrium saturation temperature was observed in all the experiments. Incipient boiling liquid superheat ranged from a few degrees to several hundred. Comparisons of these data with other data and with several analytical treatments are presented.
Inelastic scattering in planetary atmospheres. I - The Ring effect, without aerosols
NASA Technical Reports Server (NTRS)
Kattawar, G. W.; Young, A. T.; Humphreys, T. J.
1981-01-01
The contribution of inelastic molecular scattering (Rayleigh-Brillouin and rotational Raman scattering) to the filling-in of Fraunhofer lines in the light of the blue sky is studied. Aerosol fluorescence is shown to be negligible, and aerosol scattering is ignored. The angular and polarization dependences of the filling-in detail for single scattering are discussed. An approximate treatment of multiple scattering, using a backward Monte Carlo technique, makes it possible to investigate the effects of the ground albedo. As the molecular scatterings alone produce more line-filling than is observed, it seems likely that aerosols dilute the effect by contributing unaltered sunlight to the observed spectra.
NASA Technical Reports Server (NTRS)
Baker, D. N.; Jaynes, A. N.; Kanekal, S. G.; Foster, J.C.; Erickson, P. J.; Fennell, Joseph; Blake, J. B.; Zhao, H.; Li, X.; Elkington, S. R.;
2016-01-01
Two of the largest geomagnetic storms of the last decade were witnessed in 2015. On 17 March 2015, a coronal mass ejection-driven event occurred with a Dst (Disturbance Storm Time Ring Current Index) value reaching 223 nanoteslas. On 22 June 2015 another strong storm (Dst reaching 204 nanoteslas) was recorded. These two storms each produced almost total loss of radiation belt high-energy (E (Energy) greater than or approximately equal to 1 millielectronvolt) electron fluxes. Following the dropouts of radiation belt fluxes there were complex and rather remarkable recoveries of the electrons extending up to nearly 10 millielectronvolts in kinetic energy. The energized outer zone electrons showed a rich variety of pitch angle features including strong butterfly distributions with deep minima in flux at alpha equals 90 degrees. However, despite strong driving of outer zone earthward radial diffusion in these storms, the previously reported impenetrable barrier at L (L-shell magnetic field line value) approximately equal to 2.8 was pushed inward, but not significantly breached, and no E (Energy) greater than or approximately equal to 2.0 millielectronvolts electrons were seen to pass through the radiation belt slot region to reach the inner Van Allen zone. Overall, these intense storms show a wealth of novel features of acceleration, transport, and loss that are demonstrated in the present detailed analysis.
WFPC2 Observations of the URSA Minor Dwarf Spheroidal Galaxy
NASA Technical Reports Server (NTRS)
Mighell, Kenneth J.; Burke, Christopher J.
1999-01-01
We present our analysis of archival Hubble Space Telescope Wide Field Planetary Camera 2 (WFPC2) observations in F555W (approximately V) and F814W (approximately I) of the central region of the Ursa Minor dwarf spheroidal galaxy. The V versus V - I color-magnitude diagram features a sparsely populated blue horizontal branch, a steep thin red giant branch, and a narrow subgiant branch. The main sequence reaches approximately 2 magnitudes below the main-sequence turnoff (V(sup UMi, sub TO) approximately equals 23.27 +/- 0.11 mag) of the median stellar population. We compare the fiducial sequence of the Galactic globular cluster M92 (NGC 6341). The excellent match between Ursa Minor and M92 confirms that the median stellar population of the UMi dSph galaxy is metal poor ([Fe/H](sub UMi) approximately equals [Fe/H](sub M92) approximately equals -2.2 dex) and ancient (age(sub UMi)approximately equalsage(sub M92) approximately equals 14 Gyr). The B - V reddening and the absorption in V are estimated to be E(B - V) = 0.03 +/- 0.01 mag and A(sup UMi, sub V) = 0.09 +/- 0.03 mag. A new estimate of the distance modulus of Ursa Minor, (m - M)(sup UMi, sub 0) = 19.18 +/- 0.12 mag, has been derived based on fiducial-sequence fitting M92 [DELTA.V(sub UMi - M92) = 4.60 +/- 0.03 mag and DELTA(V - I)(sub UMi - M92) = 0.010 +/- 0.005 mag] and the adoption of the apparent V distance modulus for M92 of (m - M)(sup M92, sub V) = 14.67 +/- 0.08 mag (Pont et al. 1998, A&A, 329, 87). The Ursa Minor dwarf spheroidal galaxy is then at a distance of 69 +/- 4 kpc from the Sun. These HST observations indicate that Ursa Minor has had a very simple star formation history consisting mainly of a single major burst of star formation about 14 Gyr ago which lasted approximately < 2 Gyr. While we may have missed minor younger stellar populations due to the small field-of-view of the WFPC2 instrument, these observations clearly show that most of the stars in the central region Ursa Minor dwarf spheroidal galaxy are ancient. If the ancient Galactic globular clusters, like M92, formed concurrently with the early formation of the Milky Way galaxy itself, then the Ursa Minor dwarf spheroidal is probably as old as the Milky Way.
Polybenzoxazole-filled nitrile butadiene rubber compositions
NASA Technical Reports Server (NTRS)
Gajiwala, Himansu M. (Inventor); Guillot, David G. (Inventor)
2008-01-01
An insulation composition that comprises at least one nitrile butadiene rubber (NBR) having an acrylonitrile content that ranges from approximately 26% by weight to approximately 35% by weight and polybenzoxazole (PBO) fibers. The NBR may be a copolymer of acrylonitrile and butadiene and may be present in the insulation composition in a range of from approximately 45% by weight to approximately 56% by weight of a total weight of the insulation composition. The PBO fibers may be present in a range of from approximately 3% by weight to approximately 10% by weight of a total weight of the insulation composition. A rocket motor including the insulation composition and a method of insulating a rocket motor are also disclosed.
Greenland meltwater storage in firn limited by near-surface ice formation
NASA Astrophysics Data System (ADS)
Machguth, Horst; Macferrin, Mike; van As, Dirk; Box, Jason E.; Charalampidis, Charalampos; Colgan, William; Fausto, Robert S.; Meijer, Harro A. J.; Mosley-Thompson, Ellen; van de Wal, Roderik S. W.
2016-04-01
Approximately half of Greenland’s current annual mass loss is attributed to runoff from surface melt. At higher elevations, however, melt does not necessarily equal runoff, because meltwater can refreeze in the porous near-surface snow and firn. Two recent studies suggest that all or most of Greenland’s firn pore space is available for meltwater storage, making the firn an important buffer against contribution to sea level rise for decades to come. Here, we employ in situ observations and historical legacy data to demonstrate that surface runoff begins to dominate over meltwater storage well before firn pore space has been completely filled. Our observations frame the recent exceptional melt summers in 2010 and 2012 (refs ,), revealing significant changes in firn structure at different elevations caused by successive intensive melt events. In the upper regions (more than ~1,900 m above sea level), firn has undergone substantial densification, while at lower elevations, where melt is most abundant, porous firn has lost most of its capability to retain meltwater. Here, the formation of near-surface ice layers renders deep pore space difficult to access, forcing meltwater to enter an efficient surface discharge system and intensifying ice sheet mass loss earlier than previously suggested.
A Simple Decontamination Approach Using Hydrogen ...
Journal article To evaluate the use of relatively low levels of hydrogen peroxide vapor (HPV) for the inactivation of Bacillus anthracis spores within an indoor environment. Methods and Results: Laboratory-scale decontamination tests were conducted using bacterial spores of both B. anthracis Ames and Bacillus atrophaeus inoculated onto several types of materials. Pilot-scale tests were also conducted using a larger chamber furnished as an indoor office. Commercial off-the-shelf (COTS) humidifiers filled with aqueous solutions of 3% or 8% hydrogen peroxide were used to generate the HPV inside the mock office. The spores were exposed to the HPV for periods ranging from 8 hours up to one week. Conclusions: Four to seven day exposures to low levels of HPV (average air concentrations of approximately 5-10 parts per million) were effective in inactivating B. anthracis spores on multiple materials. The HPV can be generated with COTS humidifiers and household H2O2 solutions. With the exception of one test/material, B. atrophaeus spores were equally or more resistant to HPV inactivation compared to those from B. anthracis Ames. Significance and Impact of Study: This simple and effective decontamination method is another option that could be widely applied in the event of a B. anthracis spore release.
NASA Astrophysics Data System (ADS)
Yongquan, Han
2016-10-01
The ideal gas state equation is not applicable to ordinary gas, it should be applied to the Electromagnetic ``gas'' that is applied to the radiation, the radiation should be the ultimate state of matter changes or initial state, the universe is filled with radiation. That is, the ideal gas equation of state is suitable for the Singular point and the universe. Maybe someone consider that, there is no vessel can accommodate radiation, it is because the Ordinary container is too small to accommodate, if the radius of your container is the distance that Light through an hour, would you still think it can't accommodates radiation? Modern scientific determinate that the radius of the universe now is about 1027 m, assuming that the universe is a sphere whose volume is approximately: V = 4.19 × 1081 cubic meters, the temperature radiation of the universe (cosmic microwave background radiation temperature of the universe, should be the closest the average temperature of the universe) T = 3.15k, radiation pressure P = 5 × 10-6 N / m 2, according to the law of ideal gas state equation, PV / T = constant = 6 × 1075, the value of this constant is the universe, The singular point should also equal to the constant Author: hanyongquan
The change law of the universe
NASA Astrophysics Data System (ADS)
Yongquan, Han
The ideal gas state equation is not applicable to ordinary gas, it should be applied to the Electromagnetic ''gas'' that is applied to the radiation, the radiation should be the ultimate state of matter changes or initial state, the universe is filled with radiation. That is, the ideal gas equation of state is suitable for the Singular point and the universe. Maybe someone consider that, there is no vessel can accommodate radiation, it is because the Ordinary container is too small to accommodate, if the radius of your container is the distance that Light through an hour, would you still think it can't accommodates radiation? Modern scientific determinate that the radius of the universe now is about 1027 m, assuming that the universe is a sphere whose volume is approximately: V = 4.19 × 1081 cubic meters, the temperature radiation of the universe (cosmic microwave background radiation temperature of the universe, should be the closest the average temperature of the universe) T = 3.15k, radiation pressure P = 5 Ã 10-6 N / m 2, according to the law of ideal gas state equation, PV / T = 6 à 1075, the value of this constant is the universe, The singular point should also equal to the constant
Spectroscopic Evidence for Nonuniform Starspot Properties on II Pegasi
NASA Technical Reports Server (NTRS)
ONeal, Douglas; Saar, Steven H.; Neff, James E.
1998-01-01
We present spectroscopic evidence for Multiple Spot temperatures on the RS CVn star II Pegasi (HD 224085). We model the strengths of the 7055 and 8860 A TiO absorption bands in the spectrum of II Peg using weighted sums of inactive comparison spectra: a K star to represent the nonspotted photosphere and an M star to represent the spots. The best fit yields independent measurements of the starspot filling factor (f(sub s) and mean spot temperature (T(sub s)) averaged over the visible hemisphere of the star. During three-fourths of a rotation of II Peg in late 1996, we measure a constant f(sub s) approximately equals 55% +/- 5%. However, (T(sub s) varies from 3350 +/- 60 to 3550 +/- 70 K. We compute (T(sub s) for two simple models: (1) a star with two distinct spot temperatures, and (2) a star with different umbral/penumbral area ratios. The changing (T(sub s) correlates with emission strengths of H(alpha) and the Ca II infrared triplet in the sense that cooler (T(sub s) accompanies weaker emission. We explore possible implications of these results for the physical properties of the spots on II Peg and for stellar surface structure in general.
Glow plasma trigger for electron cyclotron resonance ion sources.
Vodopianov, A V; Golubev, S V; Izotov, I V; Nikolaev, A G; Oks, E M; Savkin, K P; Yushkov, G Yu
2010-02-01
Electron cyclotron resonance ion sources (ECRISs) are particularly useful for nuclear, atomic, and high energy physics, as unique high current generators of multicharged ion beams. Plasmas of gas discharges in an open magnetic trap heated by pulsed (100 micros and longer) high power (100 kW and higher) high-frequency (greater than 37.5 GHz) microwaves of gyrotrons is promising in the field of research in the development of electron cyclotron resonance sources for high charge state ion beams. Reaching high ion charge states requires a decrease in gas pressure in the magnetic trap, but this method leads to increases in time, in which the microwave discharge develops. The gas breakdown and microwave discharge duration becomes greater than or equal to the microwave pulse duration when the pressure is decreased. This makes reaching the critical plasma density initiate an electron cyclotron resonance (ECR) discharge during pulse of microwave gyrotron radiation with gas pressure lower than a certain threshold. In order to reduce losses of microwave power, it is necessary to shorten the time of development of the ECR discharge. For fast triggering of ECR discharge under low pressure in an ECRIS, we initially propose to fill the magnetic trap with the plasmas of auxiliary pulsed discharges in crossed ExB fields. The glow plasma trigger of ECR based on a Penning or magnetron discharge has made it possible not only to fill the trap with plasma with density of 10(12) cm(-3), required for a rapid increase in plasma density and finally for ECR discharge ignition, but also to initially heat the plasma electrons to T(e) approximately = 20 eV.
Ion-beam and dual-ion-beam sputter deposition of tantalum oxide films
NASA Astrophysics Data System (ADS)
Cevro, Mirza; Carter, George
1995-02-01
Ion-beam sputter deposition (IBS) and dual-ion-beam sputter deposition (DIBS) of tantalum oxide films was investigated at room temperature and compared with similar films prepared by e-gun deposition. The optical properties, i.e., refractive index and extinction coefficient, of IBS films were determined in the 250- to 1100-nm range by transmission spectrophotometry and at (lambda) equals 632.8 nm by ellipsometry. They were found to be mainly sensitive to the partial pressure of oxygen used as a reactive gas in the deposition process. The maximum value of the refractive index of IBS deposited tantalum oxide films was n equals 2.15 at (lambda) equals 550 nm and the extinction coefficient of order k equals 2 X 10-4. Films deposited by e-gun deposition had refractive index n 2.06 at (lambda) equals 550 nm. Films deposited using DIBS, i.e., deposition assisted by low energy Ar and O2 ions (Ea equals 0 to 300 eV) and low current density (Ji equals 0 to 40 (mu) A/cm2), showed no improvement in the optical properties of the films. Preferential sputtering occurred at Ea(Ar) equals 300 eV and Ji equals 20 (mu) A/cm2 and slightly oxygen deficient films were formed. Different bonding states in the tantalum-oxide films were determined by x-ray spectroscopy, whereas composition of the film and contaminants were determined by Rutherford backscattering spectroscopy (RBS). Tantalum oxide films formed by IBS contained relatively high Ar content (approximately equals 2.5%) originating from the reflected argon neutrals from the sputtering target whereas assisted deposition slightly increased the Ar content. Stress in the IBS-deposited films was measured by the bending technique. IBS-deposited films showed compressive stress with a typical value of s equals 3.2 X 109 dyn/cm2. Films deposited by concurrent ion bombardment showed an increase in the stress as a function of applied current density. The maximum was s approximately equals 5.6 X 109 dyn/cm2 for Ea equals 300 eV and Ji equals 35 (mu) A/cm2. All deposited films were amorphous as measured by the x-ray diffraction (XRD) method.
Federal Register 2010, 2011, 2012, 2013, 2014
2010-07-02
... require the filling of approximately 29.7 acres of waters of the United States, including wetlands. The... projects in the Sunridge Specific Plan area have been built. The Proposed Action is the construction of the... approximately 1.4 acres of waters of the U.S., including wetlands, to construct 134 houses, roadways, and other...
Physical Conditions of the Interstellar Medium in Star-forming Galaxies at z1.5
NASA Technical Reports Server (NTRS)
Hayashi, Masao; Ly, Chun; Shimasaku, Kazuhiro; Motohara, Kentaro; Malkan, Matthew A.; Nagao, Tohru; Kashikawa, Nobunari; Goto, Ryosuke; Naito, Yoshiaki
2015-01-01
We present results from Subaru/FMOS near-infrared (NIR) spectroscopy of 118 star-forming galaxies at z approximately equal to 1.5 in the Subaru Deep Field. These galaxies are selected as [O II] lambda 3727 emitters at z approximately equal to 1.47 and 1.62 from narrow-band imaging. We detect H alpha emission line in 115 galaxies, [O III] lambda 5007 emission line in 45 galaxies, and H Beta, [N II] lambda 6584, and [S II]lambda lambda 6716, 6731 in 13, 16, and 6 galaxies, respectively. Including the [O II] emission line, we use the six strong nebular emission lines in the individual and composite rest-frame optical spectra to investigate physical conditions of the interstellar medium in star-forming galaxies at z approximately equal to 1.5. We find a tight correlation between H alpha and [O II], which suggests that [O II] can be a good star formation rate (SFR) indicator for galaxies at z approximately equal to 1.5. The line ratios of H alpha / [O II] are consistent with those of local galaxies. We also find that [O II] emitters have strong [O III] emission lines. The [O III]/[O II] ratios are larger than normal star-forming galaxies in the local Universe, suggesting a higher ionization parameter. Less massive galaxies have larger [O III]/[O II] ratios. With evidence that the electron density is consistent with local galaxies, the high ionization of galaxies at high redshifts may be attributed to a harder radiation field by a young stellar population and/or an increase in the number of ionizing photons from each massive star.
Scale Dependence of Magnetic Helicity in the Solar Wind
NASA Technical Reports Server (NTRS)
Brandenburg, Axel; Subramanian, Kandaswamy; Balogh, Andre; Goldstein, Melvyn L.
2011-01-01
We determine the magnetic helicity, along with the magnetic energy, at high latitudes using data from the Ulysses mission. The data set spans the time period from 1993 to 1996. The basic assumption of the analysis is that the solar wind is homogeneous. Because the solar wind speed is high, we follow the approach first pioneered by Matthaeus et al. by which, under the assumption of spatial homogeneity, one can use Fourier transforms of the magnetic field time series to construct one-dimensional spectra of the magnetic energy and magnetic helicity under the assumption that the Taylor frozen-in-flow hypothesis is valid. That is a well-satisfied assumption for the data used in this study. The magnetic helicity derives from the skew-symmetric terms of the three-dimensional magnetic correlation tensor, while the symmetric terms of the tensor are used to determine the magnetic energy spectrum. Our results show a sign change of magnetic helicity at wavenumber k approximately equal to 2AU(sup -1) (or frequency nu approximately equal to 2 microHz) at distances below 2.8AU and at k approximately equal to 30AU(sup -1) (or nu approximately equal to 25 microHz) at larger distances. At small scales the magnetic helicity is positive at northern heliographic latitudes and negative at southern latitudes. The positive magnetic helicity at small scales is argued to be the result of turbulent diffusion reversing the sign relative to what is seen at small scales at the solar surface. Furthermore, the magnetic helicity declines toward solar minimum in 1996. The magnetic helicity flux integrated separately over one hemisphere amounts to about 10(sup 45) Mx(sup 2) cycle(sup -1) at large scales and to a three times lower value at smaller scales.
Functional characterization of substance P receptors in the rabbit ear artery.
Illes, P; von Falkenhausen, S
1986-05-01
Rabbit isolated ear arteries were perfused at a constant flow and stimulated with field pulses (5 Hz, 5 impulses). Different tachykinins and capsaicin depressed stimulation-induced vasoconstriction, substance P (SP) being the most potent inhibitor. The rank order of potency of the tachykinins was, SP approximately equal to physalaemin approximately equal to eledoisin greater than SP-methyl ester; that of SP and its C-terminal fragments, SP approximately equal to SP-(2-11) approximately equal to SP-(4-11) greater than SP-(6-11). SP-(1-9) was inactive. The SP antagonist (Arg5,D-Trp7,9,Nle11)SP-(5-11) 10 mumol/l shifted the concentration-response curve of SP to the right (pA2 = 5.43), whereas it did not reduce the action of capsaicin. Another SP antagonist (D-Pro4,D-Trp7,9,10)SP-(4-11) 10 mumol/l failed to affect the SP depression. Neither antagonist changed vasoconstriction by itself. Pretreatment of the arteries with a mixture of yohimbine, propranolol, atropine, diphenhydramine, burimamide, methysergide and indomethacin, all 1 mumol/l, did not influence the effect of SP or capsaicin. Only the inhibition by SP, but not that by capsaicin was abolished after mechanical destruction of the endothelium. SP, physalaemin and eledoisin, all 3 mumol/l, reduced vasoconstriction by noradrenaline or histamine; capsaicin 30 mumol/l depressed noradrenaline-induced vasoconstriction. In arteries preincubated with 3H-noradrenaline, electrical stimulation (1 Hz, 120 pulses) triggered an increase in the outflow of tritium and evoked vasoconstriction. SP 1 mumol/l did not change either basal or stimulation-evoked tritium outflow, whereas it reduced vasoconstriction.(ABSTRACT TRUNCATED AT 250 WORDS)
NASA Technical Reports Server (NTRS)
Aasi, J.; Abbott, B. P.; Abbott, R.; Abbott, T.; Abernathy, M. R.; Acernese, F.; Blackburn, Lindy L.; Camp, J. B.; Gehrels, N.; Graff, P. B.
2014-01-01
We report results from a search for gravitational waves produced by perturbed intermediate mass black holes (IMBH) in data collected by LIGO and Virgo between 2005 and 2010. The search was sensitive to astrophysical sources that produced damped sinusoid gravitational wave signals, also known as ringdowns, with frequency 50 less than or equal to italic f0/Hz less than or equal to 2000 and decay timescale 0.0001 approximately less than t/s approximately less than 0.1 characteristic of those produced in mergers of IMBH pairs. No significant gravitational wave candidate was detected. We report upper limits on the astrophysical coalescence rates of IMBHs with total binary mass 50 less than or equal to M/solar mass less than or equal to 450 and component mass ratios of either 1:1 or 4:1. For systems with total mass 100 less than or equal to M/solar mass 150, we report a 90%-confidence upper limit on the rate of binary IMBH mergers with non-spinning and equal mass components of 6:9 x 10(exp 8) Mpc(exp -3)yr(exp -1). We also report a rate upper limit for ringdown waveforms from perturbed IMBHs, radiating 1% of their mass as gravitational waves in the fundamental, l=m=2, oscillation mode, that is nearly three orders of magnitude more stringent than previous results.
Progress towards a more predictive model for hohlraum radiation drive and symmetry
NASA Astrophysics Data System (ADS)
Jones, O. S.; Suter, L. J.; Scott, H. A.; Barrios, M. A.; Farmer, W. A.; Hansen, S. B.; Liedahl, D. A.; Mauche, C. W.; Moore, A. S.; Rosen, M. D.; Salmonson, J. D.; Strozzi, D. J.; Thomas, C. A.; Turnbull, D. P.
2017-05-01
For several years, we have been calculating the radiation drive in laser-heated gold hohlraums using flux-limited heat transport with a limiter of 0.15, tabulated values of local thermodynamic equilibrium gold opacity, and an approximate model for not in a local thermodynamic equilibrium (NLTE) gold emissivity (DCA_2010). This model has been successful in predicting the radiation drive in vacuum hohlraums, but for gas-filled hohlraums used to drive capsule implosions, the model consistently predicts too much drive and capsule bang times earlier than measured. In this work, we introduce a new model that brings the calculated bang time into better agreement with the measured bang time. The new model employs (1) a numerical grid that is fully converged in space, energy, and time, (2) a modified approximate NLTE model that includes more physics and is in better agreement with more detailed offline emissivity models, and (3) a reduced flux limiter value of 0.03. We applied this model to gas-filled hohlraum experiments using high density carbon and plastic ablator capsules that had hohlraum He fill gas densities ranging from 0.06 to 1.6 mg/cc and hohlraum diameters of 5.75 or 6.72 mm. The new model predicts bang times to within ±100 ps for most experiments with low to intermediate fill densities (up to 0.85 mg/cc). This model predicts higher temperatures in the plasma than the old model and also predicts that at higher gas fill densities, a significant amount of inner beam laser energy escapes the hohlraum through the opposite laser entrance hole.
NASA Technical Reports Server (NTRS)
Wilms, Joern; Nowak, Michael A.; Dove, James B.; Fender, Robert P.; DiMatteo, Tiziana
1998-01-01
We discuss a series of observations of the black hole candidate GX 339-4 in low luminosity, spectrally hard states. We present spectral analysis of three separate archival Advanced Satellite for Cosmology and Astrophysics (ASCA) data sets and eight separate Rossi X-ray Timing Explorer (RXTE) data sets. Three of the RXTE observations were strictly simultaneous with 843 Mega Hertz and 8.3-9.1 Giga Hertz radio observations. All of these observations have (3-9 keV) flux approximately less than 10(exp-9) ergs s(exp-1) CM(exp -2). The ASCA data show evidence for an approximately 6.4 keV Fe line with equivalent width approximately 40 eV, as well as evidence for a soft excess that is well-modeled by a power law plus a multicolor blackbody spectrum with peak temperature approximately equals 150-200 eV. The RXTE data sets also show evidence of an Fe line with equivalent widths approximately equal to 20-1OO eV. Reflection models show a hardening of the RXTE spectra with decreasing X-ray flux; however, these models do not exhibit evidence of a correlation between the photon index of the incident power law flux and the solid angle subtended by the reflector. 'Sphere+disk' Comptonization models and Advection Dominated Accretion Flow (ADAF) models also provide reasonable descriptions of the RXTE data. The former models yield coronal temperatures in the range 20-50 keV and optical depths of r approximately equal to 3. The model fits to the X-ray data, however, do not simultaneously explain the observed radio properties. The most likely source of the radio flux is synchrotron emission from an extended outflow of extent greater than O(10 (exp7) GM/c2).
Wende, Charles W. J.
1976-08-17
A safety rod for a nuclear reactor has an inner end portion having a gamma absorption coefficient and neutron capture cross section approximately equal to those of the adjacent shield, a central portion containing materials of high neutron capture cross section and an outer end portion having a gamma absorption coefficient at least equal to that of the adjacent shield.
ERIC Educational Resources Information Center
Kistner, Emily O.; Muller, Keith E.
2004-01-01
Intraclass correlation and Cronbach's alpha are widely used to describe reliability of tests and measurements. Even with Gaussian data, exact distributions are known only for compound symmetric covariance (equal variances and equal correlations). Recently, large sample Gaussian approximations were derived for the distribution functions. New exact…
On the Relations among Regular, Equal Unique Variances, and Image Factor Analysis Models.
ERIC Educational Resources Information Center
Hayashi, Kentaro; Bentler, Peter M.
2000-01-01
Investigated the conditions under which the matrix of factor loadings from the factor analysis model with equal unique variances will give a good approximation to the matrix of factor loadings from the regular factor analysis model. Extends the results to the image factor analysis model. Discusses implications for practice. (SLD)
7 CFR 1755.860 - RUS specification for filled buried wires.
Code of Federal Regulations, 2011 CFR
2011-01-01
... incorporations by references were approved by the Director of the Federal Register in accordance with 5 U.S.C... unclamped specimen. The temperature of specimens and surrounding shall be 23 ±1 °C. Note: Quality assurance... −40 ±1 °C with a mandrel diameter equal to 3 times the outside diameter of the insulated conductor...
7 CFR 1755.860 - RUS specification for filled buried wires.
Code of Federal Regulations, 2010 CFR
2010-01-01
... incorporations by references were approved by the Director of the Federal Register in accordance with 5 U.S.C... unclamped specimen. The temperature of specimens and surrounding shall be 23 ±1 °C. Note: Quality assurance... −40 ±1 °C with a mandrel diameter equal to 3 times the outside diameter of the insulated conductor...
The Future of Low-Wage Service Jobs and the Workers That Hold Them. IEE Brief No. 25.
ERIC Educational Resources Information Center
Bernhardt, Annette
The business press abounds with examples of innovative companies that have created high-quality jobs; however, low-wage, deskilled jobs filled by contingent workers are equally prevalent. More than one in six U.S. workers currently hold retail jobs. The effect of globalization of trade on the retail industry is unclear. The most significant…
ERIC Educational Resources Information Center
Browne, Naima, Ed.
During the early 1980s there was a lack of research regarding gender issues for early childhood and elementary education. This document attempts to fill this chasm by addressing gender issues in science and technology for primary education schooling and early-years education. The following chapters are included: (1) "Science and Technology in the…
46 CFR 151.45-6 - Maximum amount of cargo.
Code of Federal Regulations, 2010 CFR
2010-10-01
... insulated, or 115 °F if uninsulated. If specific filling densities are designated in Subpart 151.50 of this...=Maximum volume to which tank may be loaded. V =Volume of tank. d r=Density of cargo at the temperature required for a cargo vapor pressure equal to the relief valve setting. d L=Density of cargo at the loading...
The Theme of Education of Women in "The Revolution," 1868-1870.
ERIC Educational Resources Information Center
Butcher, Patricia Smith
A feminist newspaper, "The Revolution," published between 1868 and 1870 filled a void in the popular press of the time, proclaiming the necessity of equal rights for women in all areas of life. Owned by Susan B. Anthony and edited by Elizabeth Cady Stanton, the paper repeatedly emphasized the importance of education of women. Four major themes…
46 CFR 151.45-6 - Maximum amount of cargo.
Code of Federal Regulations, 2011 CFR
2011-10-01
... insulated, or 115 °F if uninsulated. If specific filling densities are designated in Subpart 151.50 of this...=Maximum volume to which tank may be loaded. V =Volume of tank. d r=Density of cargo at the temperature required for a cargo vapor pressure equal to the relief valve setting. d L=Density of cargo at the loading...
46 CFR 151.45-6 - Maximum amount of cargo.
Code of Federal Regulations, 2014 CFR
2014-10-01
... insulated, or 115 °F if uninsulated. If specific filling densities are designated in Subpart 151.50 of this...=Maximum volume to which tank may be loaded. V =Volume of tank. d r=Density of cargo at the temperature required for a cargo vapor pressure equal to the relief valve setting. d L=Density of cargo at the loading...
46 CFR 151.45-6 - Maximum amount of cargo.
Code of Federal Regulations, 2013 CFR
2013-10-01
... insulated, or 115 °F if uninsulated. If specific filling densities are designated in Subpart 151.50 of this...=Maximum volume to which tank may be loaded. V =Volume of tank. d r=Density of cargo at the temperature required for a cargo vapor pressure equal to the relief valve setting. d L=Density of cargo at the loading...
Sonar Transducer Reliability Improvement Program, FY79 First Quarter Progress
1979-06-01
The mst significant aspects are improve- ments in the gas-filling procedures for the TR155 transducers, results of accelerated aging of the TR215...thus saved the Navy approximately $19,000 during 4 months of operation. See Section 3.3.2. b. The accelerated aging of the TR-215 ( ) transducers (AN...incompatible with the various plastics and rubbers in the transducer. Further research is necessary to find and qualify fill fluids which represent the best
Nonlinear viscoelastic response of highly filled elastomers under multiaxial finite deformation
NASA Technical Reports Server (NTRS)
Peng, Steven T. J.; Landel, Robert F.
1990-01-01
A biaxial tester was used to obtain precise biaxial stress responses of highly filled, high strain capability elastomers. Stress-relaxation experiments show that the time-dependent part of the relaxation response can be reasonably approximated by a function which is strain and biaxiality independent. Thus, isochronal data from the stress-relaxation curves can be used to determine the stored energy density function. The complex behavior of the elastomers under biaxial deformation may be caused by dewetting.
Landslide assessment of Newell Creek Canyon, Oregon City, Oregon
DOE Office of Scientific and Technical Information (OSTI.GOV)
Growney, L.; Burris, L.; Garletts, D.
1993-04-01
A study has been conducted in Newell Creek Canyon near Oregon City, Oregon, T3S, T2S, R2E. A landslide inventory has located 53 landslides in the 2.8 km[sup 2] area. The landslides range in area from approximately 15,000m[sup 2] to 10m[sup 2]. Past slides cover an approximate 7% of the canyon area. Landslide processes include: slump, slump-translational, slump-earthflow and earthflow. Hard, impermeable clay-rich layers in the Troutdale Formation form the failure planes for most of the slides. Slopes composed of Troutdale material may seem to be stable, but when cuts and fills are produced, slope failure is common because of themore » perched water tables and impermeable failure planes. Good examples of cut and fill failures are present on Highway 213 which passes through Newell Creek Canyon. Almost every cut and fill has failed since the road construction began. The latest failure is in the fill located at mile-post 2.1. From data gathered, a slope stability risk map was generated. Stability risk ratings are divided into three groups: high, moderate and low. High risk of slope instability is designated to all landslides mapped in the slide inventory. Moderate risk is designated to slopes in the Troutdale Formation greater than 8[degree]. Low risk is designated to slopes in the Troutdale Formation less than 8[degree].« less
Implications of Earth analogs to Martian sulfate-filled Fractures
NASA Astrophysics Data System (ADS)
Holt, R. M.; Powers, D. W.
2017-12-01
Sulfate-filled fractures in fine-grained sediments on Mars are interpreted to be the result of fluid movement during deep burial. Fractures in the Dewey Lake (aka Quartermaster) Formation of southeastern New Mexico and west Texas are filled with gypsum that is at least partially synsedimentary. Sulfate in the Dewey Lake takes two principal forms: gypsum cement and gypsum (mainly fibrous) that fills fractures ranging from horizontal to vertical. Apertures are mainly mm-scale, though some are > 1 cm. The gypsum is antitaxial, fibrous, commonly approximately perpendicular to the wall rock, and displays suture lines and relics of the wall rock. Direct evidence of synsedimentary, near-surface origin includes gypsum intraclasts, intraclasts that include smaller intraclasts that contain gypsum clasts, intraclasts of gypsum with suture lines, gypsum concentrated in small desiccation cracks, and intraclasts that include fibrous gypsum-filled fractures that terminate at the eroded clast boundary. Dewey Lake fracture fillings suggest that their Martian analogs may also have originated in the shallow subsurface, shortly following the deposition of Martian sediments, in the presence of shallow aquifers.
Introducing Perception and Modelling of Spatial Randomness in Classroom
ERIC Educational Resources Information Center
De Nóbrega, José Renato
2017-01-01
A strategy to facilitate understanding of spatial randomness is described, using student activities developed in sequence: looking at spatial patterns, simulating approximate spatial randomness using a grid of equally-likely squares, using binomial probabilities for approximations and predictions and then comparing with given Poisson…
NASA Technical Reports Server (NTRS)
Dobson, C. C.; Eskridge, R. H.; Lee, M. H.
2000-01-01
A four-channel laser transmissometer has been used to probe the soot content of the exhaust plume of the X-34 60k-lb thrust Fastrac rocket engine at NASA's Marshall Space Flight Center. The transmission measurements were made at an axial location about equal 1.65 nozzle diameters from the exit plane and are interpreted in terms of homogeneous radial zones to yield extinction coefficients from 0.5-8.4 per meter. The corresponding soot mass density, spatially averaged over the plume cross section, is, for Rayleigh particles, approximately equal to 0.7 micrograms/cubic cm and alternative particle distributions are briefly considered. Absolute plume radiance at the laser wavelength (515 nm) is estimated from the data at approximately equal to 2.200 K equivalent blackbody temperature, and temporal correlations in emission from several spatial locations are noted.
HST WFC3 Early Release Science: Emission-Line Galaxies from IR Grism Observations
NASA Technical Reports Server (NTRS)
Straughn, A. N.; Kuntschner, H.; Kuemmel, M.; Walsh, J. R.; Cohen, S. H.; Gardner, J. P.; Windhorst, R. A.; O'Connell, R. W.; Pirzkal, N.; Meurer, G.;
2010-01-01
We present grism spectra of emission line galaxies (ELGs) from 0.6-1.6 microns from the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST). These new infrared grism data augment previous optical Advanced Camera for Surveys G800L (0.6-0.95 micron) grism data in GOODS South, extending the wavelength coverage well past the G800L red cutoff. The ERS grism field was observed at a depth of 2 orbits per grism, yielding spectra of hundreds of faint objects, a subset of which are presented here. ELGs are studied via the Ha, [O III ], and [OII] emission lines detected in the redshift ranges 0.2 less than or equal to z less than or equal to 1.6, 1.2 less than or equal to z less than or equal to 2.4 and 2.0 less than or equal to z less than or equal to 3.6 respectively in the G102 (0.8-1.1 microns; R approximately 210) and C141 (1.1-1.6 microns; R approximately 130) grisms. The higher spectral resolution afforded by the WFC3 grisms also reveals emission lines not detectable with the G800L grism (e.g., [S II] and [S III] lines). From these relatively shallow observations, line luminosities, star formation rates, and grism spectroscopic redshifts are determined for a total of 25 ELGs to M(sub AB)(F098M) approximately 25 mag. The faintest source in our sample with a strong but unidentified emission line--is MAB(F098M)=26.9 mag. We also detect the expected trend of lower specific star formation rates for the highest mass galaxies in the sample, indicative of downsizing and discovered previously from large surveys. These results demonstrate the remarkable efficiency and capability of the WFC3 NIR grisms for measuring galaxy properties to faint magnitudes.
Dispensing error rate after implementation of an automated pharmacy carousel system.
Oswald, Scott; Caldwell, Richard
2007-07-01
A study was conducted to determine filling and dispensing error rates before and after the implementation of an automated pharmacy carousel system (APCS). The study was conducted in a 613-bed acute and tertiary care university hospital. Before the implementation of the APCS, filling and dispensing rates were recorded during October through November 2004 and January 2005. Postimplementation data were collected during May through June 2006. Errors were recorded in three areas of pharmacy operations: first-dose or missing medication fill, automated dispensing cabinet fill, and interdepartmental request fill. A filling error was defined as an error caught by a pharmacist during the verification step. A dispensing error was defined as an error caught by a pharmacist observer after verification by the pharmacist. Before implementation of the APCS, 422 first-dose or missing medication orders were observed between October 2004 and January 2005. Independent data collected in December 2005, approximately six weeks after the introduction of the APCS, found that filling and error rates had increased. The filling rate for automated dispensing cabinets was associated with the largest decrease in errors. Filling and dispensing error rates had decreased by December 2005. In terms of interdepartmental request fill, no dispensing errors were noted in 123 clinic orders dispensed before the implementation of the APCS. One dispensing error out of 85 clinic orders was identified after implementation of the APCS. The implementation of an APCS at a university hospital decreased medication filling errors related to automated cabinets only and did not affect other filling and dispensing errors.
Thin, porous metal sheets and methods for making the same
Liu, Wei; Li, Xiaohong Shari; Canfield, Nathan L.
2015-07-14
Thin, porous metal sheets and methods for forming them are presented to enable a variety of applications and devices. The thin, porous metal sheets are less than or equal to approximately 200 .mu.m thick, have a porosity between 25% and 75% by volume, and have pores with an average diameter less than or equal to approximately 2 .mu.m. The thin, porous metal sheets can be fabricated by preparing a slurry having between 10 and 50 wt % solvent and between 20 and 80 wt % powder of a metal precursor. The average particle size in the metal precursor powder should be between 100 nm and 5 .mu.m.
Driver for solar cell I-V characteristic plots
NASA Technical Reports Server (NTRS)
Turner, G. B. (Inventor)
1980-01-01
A bipolar voltage ramp generator which applies a linear voltage through a resistor to a solar cell for plotting its current versus voltage (I-V) characteristic between short circuit and open circuit conditions is disclosed. The generator has automatic stops at the end points. The resistor serves the multiple purpose of providing a current sensing resistor, setting the full-scale current value, and providing a load line with a slope approximately equal to one, such that it will pass through the origin and the approximate center of the I-V curve with about equal distance from that center to each of the end points.
Engineering scale demonstration of a prospective Cast Stone process
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cozzi, A.; Fowley, M.; Hansen, E.
2014-09-30
This report documents an engineering-scale demonstration with non-radioactive simulants that was performed at SRNL using the Scaled Continuous Processing Facility (SCPF) to fill an 8.5 ft container with simulated Cast Stone grout. The Cast Stone formulation was chosen from the previous screening tests. Legacy salt solution from previous Hanford salt waste testing was adjusted to correspond to the average composition generated from the Hanford Tank Waste Operation Simulator (HTWOS). The dry blend materials, ordinary portland cement (OPC), Class F fly ash, and ground granulated blast furnace slag (GGBFS or BFS), were obtained from Lafarge North America in Pasco, WA. Overmore » three days, the SCPF was used to fill a 1600 gallon container, staged outside the facility, with simulated Cast Stone grout. The container, staged outside the building approximately 60 ft from the SCPF, was instrumented with x-, y-, and z-axis thermocouples to monitor curing temperature. The container was also fitted with two formed core sampling vials. For the operation, the targeted grout production rate was 1.5 gpm. This required a salt solution flow rate of approximately 1 gpm and a premix feed rate of approximately 580 lb/h. During the final day of operation, the dry feed rate was increased to evaluate the ability of the system to handle increased throughput. Although non-steady state operational periods created free surface liquids, no bleed water was observed either before or after operations. The final surface slope at a fill height of 39.5 inches was 1-1.5 inches across the 8.5 foot diameter container, highest at the final fill point and lowest diametrically opposed to the fill point. During processing, grout was collected in cylindrical containers from both the mixer discharge and the discharge into the container. These samples were stored in a humid environment either in a closed box proximal to the container or inside the laboratory. Additional samples collected at these sampling points were analyzed for rheological properties and density. Both the rheological properties (plastic viscosity and yield strength) and density were consistent with previous and later SCPF runs.« less
l/f Noise in the Superconducting Transition of a MgB2 Thin Film
NASA Technical Reports Server (NTRS)
Lakew, B.; Aslam, S.; Jones, H.; Stevenson, T.; Cao, N.
2010-01-01
The noise voltage spectral density in the superconducting transition of a MgB2 thin film on a SiN-coated Si thick substrate was measured over the frequency range 1 Hz-to-1 KHz. Using established bolometer noise theory the theoretical noise components due to Johnson, 1/f(excess) and phonon noise are modeled to the measured data. It is shown that for the case of a MgB2 thin film in the vicinity of the mid-point of transition, coupled to a heat sink via a fairly high thermal conductance (approximately equal to 10(sup -1) W/K)) that the measured noise voltage spectrum is 1/f limited and exhibits lit dependence with a varying between 0.3 and 0.5 in the measured frequency range. At a video frame rate frequency of 30 Hz the measured noise voltage density in the film is approximately equal to 61 nV /the square root of HZ, using this value an upper limit of electrical NEP approximately equal to 0.67pW / the square root of Hz is implied for a practical MgB2 bolometer operating at 36.1 K.
Composite superconducting wires obtained by high-rate tinning in molten Bi-Pb-Sr-Ca-Cu-O system
NASA Technical Reports Server (NTRS)
Grosav, A. D.; Konopko, L. A.; Leporda, N. I.
1991-01-01
Long lengths of metal superconductor composites were prepared by passing a copper wire through the bismuth based molten oxide system at a constant speed. The key to successful composite preparation is the high pulling speed involved, which permits minimization of the severe interaction between the unbuffered metal surface and the oxide melt. Depending on the temperature of the melt and the pulling speed, a coating with different thickness and microstructure appeared. The nonannealed thick coatings contained a Bi2(Sr,Ca)2Cu1O6 phase as a major component. After relatively short time annealing at 800 C, both resistivity and initial magnetization versus temperature measurements show superconducting transitions beginning in the 110 to 115 K region. The effects of annealing and composition on obtained results are discussed. This method of manufacture led to the fabrication of wire with a copper core in a dense covering with uniform thickness of about h approximately equal to 5 to 50 microns. Composite wires with h approximately equal to 10 microns (h/d approximately equal to 0.1) sustained bending on a 15 mm radius frame without cracking during flexing.
NASA Technical Reports Server (NTRS)
Heinrich, W.; Drechsel, H.; Brechtmann, C.; Beer, J.
1985-01-01
Charge changing nuclear collisions in plastic nuclear track detectors were studied using a new experimental technique of automatic track measurement for etched tracks in plastic detectors. Partial cross sections for the production of fragments of charge Z approximately 8 were measured for projectile nuclei of charge 9 approximately Z approximately 26 in the detector material CR39 and in silver. for this purpose three independent experiments were performed using Bevalac beams. The first one was an exposure of a stack of CR39 plastic plates to 1.8 GeV/nucl. Ar-40 nuclei. The second one was an exposure of another CR39 stack of 1.7 GeV/nucl. Fe-56 projectiles. In the third experiment a mixed stack of CR39 plates and silver foils was irradiated with 1.7 GeV/nucl. Fe-56 nuclei. Thus the measurement of nuclear cross sections in a light target (CR39 = C12H18O7) and as well in a heavy target (silver) was possible.
Bender, John F.; Schimpff, Stephen C.; Young, Viola Mae; Fortner, Clarence L.; Brouillet, Mary D.; Love, Lillian J.; Wiernik, Peter H.
1979-01-01
A total of 38 adult patients with acute leukemia who were undergoing remission induction chemotherapy in regular patient rooms were randomly allocated to one of two oral nonabsorbable antibiotic regimens for infection prophylaxis (gentamicin, vancomycin, and nystatin [GVN] or gentamicin and nystatin [GN]) to evaluate whether vancomycin was a necessary component. The patient population in both groups were comparable. Tolerance to GVN was less than GN but compliance was approximately equal (>85% in both groups). Patients receiving vancomycin demonstrated greater overall alimentary tract microbial suppression; however, acquisition of potential pathogens was approximately equal in both groups. The incidence of bacteremia, as well as the overall incidence of infection as related to the number of days at various granulocyte levels, was also approximately equal in both groups. Group D Streptococcus species were poorly suppressed by GN compared with GVN, although no patient developed an infection with these organisms. Colonization by newly acquired gram-negative bacilli was significantly less in the GN group (GN, 3 colonizations; GVN, 13 colonizations; P < 0.01). It is concluded that vancomycin may be safely eliminated from the GVN regimen provided microbiological data is monitored to detect resistant organisms. PMID:464573
RIGHT AND LEFT VENTRICULAR DIASTOLIC PRESSURE–VOLUME RELATIONS: A COMPREHENSIVE REVIEW
Pasipoularides, Ares
2012-01-01
Ventricular compliance alterations can affect cardiac performance and adaptations. Moreover, diastolic mechanics are important in assessing both diastolic and systolic function, since any filling impairment can compromise systolic function. A sigmoidal passive filling pressure-volume relationship, developed using chronically instrumented, awake-animal disease models, is clinically adaptable to evaluating diastolic dynamics using subject-specific micromanometric and volumetric data from the entire filling period of any heartbeat(s). This innovative relationship is the global, integrated expression of chamber geometry, wall thickness, and passive myocardial wall properties. Chamber and myocardial compliance curves of both ventricles can be computed by the sigmoidal methodology over the entire filling period and plotted over appropriate filling pressure ranges. Important characteristics of the compliance curves can be examined and compared between the right and the left ventricle, and for different physiological and pathological conditions. The sigmoidal paradigm is more accurate and, therefore, a better alternative to the conventional exponential pressure-volume approximation. PMID:23179133
Near equality of ion phase space densities at earth, Jupiter, and Saturn
NASA Technical Reports Server (NTRS)
Cheng, A. F.; Krimigis, S. M.; Armstrong, T. P.
1985-01-01
Energetic-ion phase-space density profiles are strikingly similar in the inner magnetospheres of earth, Jupiter, and Saturn for ions of first adiabatic invariant near 100 MeV/G and small mirror latitudes. Losses occur inside L approximately equal to 7 for Jupiter and Saturn and inside L approximately equal to 5 at earth. At these L values there exist steep plasma-density gradients at all three planets, associated with the Io plasma torus at Jupiter, the Rhea-Dione-Tethys torus at Saturn, and the plasmasphere at earth. Measurements of ion flux-tube contents at Jupiter and Saturn by the low-energy charged-particle experiment show that these are similar (for O ions at L = 5-9) to those at earth (for protons at L = 2-6). Furthermore, the thermal-ion flux-tube contents from Voyager plasma-science data at Jupiter and Saturn are also very nearly equal, and again similar to those at earth, differing by less than a factor of 3 at the respective L values. The near equality of energetic and thermal ion flux-tube contents at earth, Jupiter, and Saturn suggests the possibility of strong physical analogies in the interaction between plasma and energetic particles at the plasma tori/plasma sheets of Jupiter and Saturn and the plasmasphere of earth.
NASA Astrophysics Data System (ADS)
Pejović, Milić M.; Milosavljević, Čedomir S.; Pejović, Momčilo M.
2003-06-01
This article describes an electrical system aimed at measuring and data acquisition of breakdown voltages of vacuum and gas-filled tubes. The measurements were performed using a nitrogen-filled tube at 4 mbar pressure. Based on the measured breakdown voltage data as a function of the applied voltage increase rate, a static breakdown voltage is estimated for the applied voltage gradient ranging from 0.1 to 1 V s-1 and from 1 to 10 V s-1. The histograms of breakdown voltages versus applied voltage increase rates from 0.1 and 0.5 V s-1 are approximated by the probability density functions using a fitting procedure.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sankar, I. V., E-mail: ivshankar27@gmail.com; Chatterjee, Ashok, E-mail: ivshankar27@gmail.com
2014-04-24
The two-dimensional extended Holstein-Hubbard model (EHH) has been considered at strong correlation regime in the non-half-filled band case to understand the self-trapping transition of electrons in strongly correlated electron system. We have used the method of optimized canonical transformations to transform an EHH model into an effective extended Hubbard (EEH) model. In the strong on-site correlation limit an EH model can be transformed into a t-J model which is finally solved using Hartree-Fock approximation (HFA). We found that, for non-half-filled band case, the transition is abrupt in the adiabatic region whereas it is continuous in the anti-adiabatic region.
Nelson, George H.
1984-01-01
U.S. Army Corps of Engineers permits are required for discharges of dredged or fill-material downstream from the ' headwaters ' of specified streams. The term ' headwaters ' is defined as the point of a freshwater (non-tidal) stream above which the average flow is less than 5 cu ft/s. Maps of the Mobile District area showing (1) lines of equal average streamflow, and (2) lines of equal drainage areas required to produce an average flow of 5 cu ft/s are contained in this report. These maps are for use by the Corps of Engineers in their permitting program. (USGS)
[The distribution of health resources: a hybrid model of equality and maximization].
Farmer, Yanick
2012-01-01
In the allocation of resources for health care, it is generally acknowledged that models based exclusively either on efficiency and maximizing the cost/benefit ratio of interventions, or on equity and justice through the notion of "maximin," are unsatisfactory when taken separately. To fill this gap, this commentary suggests a hybrid model of resource allocation that integrates the idea of a random distribution of resources using a lottery. The general aim of this model is to safeguard the notions of justice and equal access to resources to the maximum extent possible in a climate where budget restrictions and the economic downturn may lead to future reductions in services.
Pawar, Ajinkya M; Thakur, Bhagyashree; Metzger, Zvi; Kfir, Anda; Pawar, Mansing
2016-01-01
Aim: The current ex vivo study compared the efficacy of removing root fillings using ProTaper retreatment files followed by either WaveOne reciprocating file or the Self-Adjusting File (SAF). Materials and Methods: Forty maxillary canines with single oval root canal were selected and sectioned to obtain 18-mm root segments. The root canals were instrumented with WaveOne primary files, followed by obturation using warm lateral compaction, and the sealer was allowed to fully set. The teeth were then divided into two equal groups (N = 20). Initial removal of the bulk of root filling material was performed with ProTaper retreatment files, followed by either WaveOne files (Group 1) or SAF (Group 2). Endosolv R was used as a gutta-percha softener. Preoperative and postoperative high-resolution cone-beam computed tomography (CBCT) was used to measure the volume of the root filling residue that was left after the procedure. Statistical analysis was performed using t-test. Results: The mean volume of root filling residue in Group 1 was 9.4 (±0.5) mm3, whereas in Group 2 the residue volume was 2.6 (±0.4) mm3, (P < 0.001; t-test). Conclusions: When SAF was used after ProTaper retreatment files, significantly less root filling residue was left in the canals compared to when WaveOne was used. PMID:26957798
Modal Filters for Infrared Interferometry
NASA Technical Reports Server (NTRS)
Ksendzov, Alexander; MacDonald, Daniel R.; Soibel, Alexander
2009-01-01
Modal filters in the approximately equal to 10-micrometer spectral range have been implemented as planar dielectric waveguides in infrared interferometric applications such as searching for Earth-like planets. When looking for a small, dim object ("Earth") in close proximity to a large, bright object ("Sun"), the interferometric technique uses beams from two telescopes combined with a 180 phase shift in order to cancel the light from a brighter object. The interferometer baseline can be adjusted so that, at the same time, the light from the dimmer object arrives at the combiner in phase. This light can be detected and its infrared (IR) optical spectra can be studied. The cancellation of light from the "Sun" to approximately equal to 10(exp 6) is required; this is not possible without special devices-modal filters- that equalize the wavefronts arriving from the two telescopes. Currently, modal filters in the approximately equal to 10-micrometer spectral range are implemented as single- mode fibers. Using semiconductor technology, single-mode waveguides for use as modal filters were fabricated. Two designs were implemented: one using an InGaAs waveguide layer matched to an InP substrate, and one using InAlAs matched to an InP substrate. Photon Design software was used to design the waveguides, with the main feature all designs being single-mode operation in the 10.5- to 17-micrometer spectral range. Preliminary results show that the filter's rejection ratio is 26 dB.
The Effects of Equal Status Cross-Sex Contact on Students' Sex Stereotyped Attitudes and Behavior.
ERIC Educational Resources Information Center
Lockheed, Marlaine E.; Harris, Abigail M.
Standard least squares regression techniques are used to estimate the effects of non-sex-role stereotypes, equal-status cross-sex interaction and female leadership on changes in children's sex stereotyped attitudes. Included are a pretest, experimental treatment, and post-test. Teachers of approximately 400 fourth and fifth grade children received…
Analysis and Technical Report of Remote Sensing Data for the USS Kinsman
2000-01-01
navigational aids in the Atchafalaya channel and filling it with an abatis of live oak trees , except for an eighty-foot passage. Barges were prepared...with additional trees to fill the gap when required. However, with the fall of New Orleans on April 25, 1862, the Confederates abandoned the...and 350 m south along the Bayou Shaffer Waterfront. The extant width of the site was approximately 8 to 10 m; however, the presence of tree stumps in
2013-06-01
outer bank threatened a Fed- eral levee that protects adjacent homes and farmland. The eroded chute bank approached the toe of the levee causing...design drawing for repairing the levee toe . Approximately 30,000 tons of riprap were placed to re-establish the bank in front of the scour hole...Sediment was needed to fill and stabilize the scour hole between the riprap bank and the toe of the levee. The volume required to fill the scour hole
Barja-Fidalgo, Fernanda; Moutinho-Ribeiro, Michele; Oliveira, Maria Angelina Amorim; de Oliveira, Branca Heloísa
2011-01-01
The aim of this systematic review was to determine whether there is a root canal filling for deciduous teeth equally or more effective than zinc oxide-eugenol cement (ZOE). Six clinical trials selected for inclusion were independently reviewed by two researchers. Only two showed statistically significant different success rates between the test and the control groups. One found that an iodoform paste with calcium hydroxide (IP + Ca) performed better than ZOE, and the other found that ZOE performed similarly to IP + Ca. The other four studies compared ZOE with an iodoform paste (IP), a calcium hydroxide cement (Ca(OH)2), or IP + Ca. In these trials, the success rates in the ZOE groups were slightly lower than in the other groups. There seems to be no convincing evidence to support the superiority of any material over ZOE, and both ZOE and IP + Ca appear to be suitable as root canal fillings for deciduous teeth. PMID:21991471
The Filled Arm Fizeau Telescope (FFT)
NASA Technical Reports Server (NTRS)
Synnott, S. P.
1991-01-01
Attention is given to the design of a Mills Cross imaging interferometer in which the arms are fully filled with mirror segments of a Ritchey-Chretien primary and which has sensitivity to 27th magnitude per pixel and resolution a factor of 10 greater than Hubble. The optical design, structural configuration, thermal disturbances, and vibration, material, control, and metrology issues, as well as scientific capabilities are discussed, and technology needs are identified. The technologies under consideration are similar to those required for the development of the other imaging interferometers that have been proposed over the past decade. A comparison of the imaging capabilities of a 30-m diameter FFT, an 8-m telescope with a collecting area equal to that of the FFT, and the HST is presented.
40 CFR 63.2872 - What definitions apply to this subpart?
Code of Federal Regulations, 2010 CFR
2010-07-01
... NESHAP General Provisions. (c) In this section as follows: Accounting month means a time interval defined... consistent and regular basis. An accounting month will consist of approximately 4 to 5 calendar weeks and each accounting month will be of approximate equal duration. An accounting month may not correspond...
The Binary Temperature-Composition Phase Diagram
ERIC Educational Resources Information Center
Sanders, Philip C.; Reeves, James H.; Messina, Michael
2006-01-01
The equations for the liquid and gas lines in the binary temperature-composition phase diagram are derived by approximating that delta(H)[subscript vap] of the two liquids are equal. It is shown that within this approximation, the resulting equations are not too difficult to present in an undergraduate physical chemistry lecture.
Ayers, Paul W; Parr, Robert G
2008-08-07
Higher-order global softnesses, local softnesses, and softness kernels are defined along with their hardness inverses. The local hardness equalization principle recently derived by the authors is extended to arbitrary order. The resulting hierarchy of equalization principles indicates that the electronegativity/chemical potential, local hardness, and local hyperhardnesses all are constant when evaluated for the ground-state electron density. The new equalization principles can be used to test whether a trial electron density is an accurate approximation to the true ground-state density and to discover molecules with desired reactive properties, as encapsulated by their chemical reactivity indicators.
ERIC Educational Resources Information Center
Hensel, Nancy
This brief report summarizes a longer report with the same title. It examines the problems of the increasingly severe shortage of qualified teachers in American higher education and the need to recruit large numbers of new faculty during the next decade and, as the potential solution to both problems, the recruiting of women to fill these faculty…
ERIC Educational Resources Information Center
Bowman, Kristi; Nantl, Jiri
2014-01-01
In 1954, the United States Supreme Court decided "Brown v. Board of Education," a case that is known throughout the US and around the world for its strong statements about equality and about the importance of education. The years since the "Brown" decision have been filled with many changes in US law and society. From the…
Dohrmann, Paul R; Manhart, Carol M; Downey, Christopher D; McHenry, Charles S
2011-11-18
Upon completion of synthesis of an Okazaki fragment, the lagging strand replicase must recycle to the next primer at the replication fork in under 0.1 s to sustain the physiological rate of DNA synthesis. We tested the collision model that posits that cycling is triggered by the polymerase encountering the 5'-end of the preceding Okazaki fragment. Probing with surface plasmon resonance, DNA polymerase III holoenzyme initiation complexes were formed on an immobilized gapped template. Initiation complexes exhibit a half-life of dissociation of approximately 15 min. Reduction in gap size to 1 nt increased the rate of dissociation 2.5-fold, and complete filling of the gap increased the off-rate an additional 3-fold (t(1/2)~2 min). An exogenous primed template and ATP accelerated dissociation an additional 4-fold in a reaction that required complete filling of the gap. Neither a 5'-triphosphate nor a 5'-RNA terminated oligonucleotide downstream of the polymerase accelerated dissociation further. Thus, the rate of polymerase release upon gap completion and collision with a downstream Okazaki fragment is 1000-fold too slow to support an adequate rate of cycling and likely provides a backup mechanism to enable polymerase release when the other cycling signals are absent. Kinetic measurements indicate that addition of the last nucleotide to fill the gap is not the rate-limiting step for polymerase release and cycling. Modest (approximately 7 nt) strand displacement is observed after the gap between model Okazaki fragments is filled. To determine the identity of the protein that senses gap filling to modulate affinity of the replicase for the template, we performed photo-cross-linking experiments with highly reactive and non-chemoselective diazirines. Only the α subunit cross-linked, indicating that it serves as the sensor. Copyright © 2011 Elsevier Ltd. All rights reserved.
SARS-related perceptions in Hong Kong.
Lau, Joseph T F; Yang, Xilin; Pang, Ellie; Tsui, H Y; Wong, Eric; Wing, Yun Kwok
2005-03-01
To understand different aspects of community responses related to severe acute respiratory syndrome (SARS), 2 population-based, random telephone surveys were conducted in June 2003 and January 2004 in Hong Kong. More than 70% of respondents would avoid visiting hospitals or mainland China to avoid contracting SARS. Most respondents believed that SARS could be transmitted through droplets, fomites, sewage, and animals. More than 90% believed that public health measures were efficacious means of prevention; 40.4% believed that SARS would resurge in Hong Kong; and approximately equals 70% would then wear masks in public places. High percentages of respondents felt helpless, horrified, and apprehensive because of SARS. Approximately 16% showed signs of posttraumatic symptoms, and approximately equals 40% perceived increased stress in family or work settings. The general public in Hong Kong has been very vigilant about SARS but needs to be more psychologically prepared to face a resurgence of the epidemic.
IUE observations of the Jovian HI Lyman alpha emission (1979 - 1982)
NASA Technical Reports Server (NTRS)
Skinner, T. E.; Durrance, S. T.; Feldman, P. D.; Moos, H. W.
1982-01-01
Observations of the Jovian H ion Lyman emission made with the IUE observatory beginning in December 1978 just before the time of the Voyager encounters and extending through January 1982 are presented. A constant disk center brightness of about 8 kR is observed for the central meridian longitude range wavelength III approximately equal 200 deg to 360 deg and a variable brightness 9-15 kR is found for the range lambda III approximately 50 deg to 150 deg. These brightness values persisted throughout the three years of observation. The hydrogen bulge near wavelength III approximately equal 100 deg appears to be a permanent feature of the Jovian atmosphere, and no long term change of the planetary Lyman emission is seen. Since the early IUE observations were made near the two Voyager encounters, this indicates that no substantial changes in the atomic hydrogen concentration or the average atmospheric conditions took place between then and now.
Band-filling of solution-synthesized CdS nanowires.
Puthussery, James; Lan, Aidong; Kosel, Thomas H; Kuno, Masaru
2008-02-01
The band edge optical characterization of solution-synthesized CdS nanowires (NWs) is described. Investigated wires are made through a solution-liquid-solid approach that entails the use of low-melting bimetallic catalyst particles to seed NW growth. Resulting diameters are approximately 14 nm, and lengths exceed 1 microm. Ensemble diameter distributions are approximately 13%, with corresponding intrawire diameter variations of approximately 5%. High-resolution transmission electron micrographs show that the wires are highly crystalline and have the wurtzite structure with growth along at least two directions: [0001] and [1010]. Band edge emission is observed with estimated quantum yields between approximately 0.05% and 1%. Complementary photoluminescence excitation spectra show structure consistent with the linear absorption. Carrier cooling dynamics are subsequently examined through ensemble lifetime and transient differential absorption measurements. The former reveals unexpectedly long band edge decays that extend beyond tens of nanoseconds. The latter indicates rapid intraband carrier cooling on time scales of 300-400 fs. Subsequent recovery at the band edge contains significant Auger contributions at high intensities which are usurped by other, possibly surface-related, carrier relaxation pathways at lower intensities. Furthermore, an unusual intensity-dependent transient broadening is seen, connected with these long decays. The effect likely stems from band-filling on the basis of an analysis of observed spectral shifts and line widths.
NASA Astrophysics Data System (ADS)
Leilaeioun, Mehdi; Holman, Zachary C.
2016-09-01
An approximate expression proposed by Green predicts the maximum obtainable fill factor (FF) of a solar cell from its open-circuit voltage (Voc). The expression was originally suggested for silicon solar cells that behave according to a single-diode model and, in addition to Voc, it requires an ideality factor as input. It is now commonly applied to silicon cells by assuming a unity ideality factor—even when the cells are not in low injection—as well as to non-silicon cells. Here, we evaluate the accuracy of the expression in several cases. In particular, we calculate the recombination-limited FF and Voc of hypothetical silicon solar cells from simulated lifetime curves, and compare the exact FF to that obtained with the approximate expression using assumed ideality factors. Considering cells with a variety of recombination mechanisms, wafer doping densities, and photogenerated current densities reveals the range of conditions under which the approximate expression can safely be used. We find that the expression is unable to predict FF generally: For a typical silicon solar cell under one-sun illumination, the error is approximately 6% absolute with an assumed ideality factor of 1. Use of the expression should thus be restricted to cells under very low or very high injection.
Mobile spin impurity in an optical lattice
NASA Astrophysics Data System (ADS)
Duncan, C. W.; Bellotti, F. F.; Öhberg, P.; Zinner, N. T.; Valiente, M.
2017-07-01
We investigate the Fermi polaron problem in a spin-1/2 Fermi gas in an optical lattice for the limit of both strong repulsive contact interactions and one dimension. In this limit, a polaronic-like behaviour is not expected, and the physics is that of a magnon or impurity. While the charge degrees of freedom of the system are frozen, the resulting tight-binding Hamiltonian for the impurity’s spin exhibits an intriguing structure that strongly depends on the filling factor of the lattice potential. This filling dependency also transfers to the nature of the interactions for the case of two magnons and the important spin balanced case. At low filling, and up until near unit filling, the single impurity Hamiltonian faithfully reproduces a single-band, quasi-homogeneous tight-binding problem. As the filling is increased and the second band of the single particle spectrum of the periodic potential is progressively filled, the impurity Hamiltonian, at low energies, describes a single particle trapped in a multi-well potential. Interestingly, once the first two bands are fully filled, the impurity Hamiltonian is a near-perfect realisation of the Su-Schrieffer-Heeger model. Our studies, which go well beyond the single-band approximation, that is, the Hubbard model, pave the way for the realisation of interacting one-dimensional models of condensed matter physics.
Production of continuous piezoelectric ceramic fibers for smart materials and active control devices
NASA Astrophysics Data System (ADS)
French, Jonathan D.; Weitz, Gregory E.; Luke, John E.; Cass, Richard B.; Jadidian, Bahram; Bhargava, Parag; Safari, Ahmad
1997-05-01
Advanced Cerametrics Inc. has conceived of and developed the Viscous-Suspension-Spinning Process (VSSP) to produce continuous fine filaments of nearly any powdered ceramic materials. VSSP lead zirconate titanate (PZT) fiber tows with 100 and 790 filaments have been spun in continuous lengths exceeding 1700 meters. Sintered PZT filaments typically are 10 - 25 microns in diameter and have moderate flexibility. Prior to carrier burnout and sintering, VSSP PZT fibers can be formed into 2D and 3D shapes using conventional textile and composite forming processes. While the extension of PZT is on the order of 20 microns per linear inch, a woven, wound or braided structure can contain very long lengths of PZT fiber and generate comparatively large output strokes from relatively small volumes. These structures are intended for applications such as bipolar actuators for fiber optic assembly and repair, vibration and noise damping for aircraft, rotorcraft, automobiles and home applications, vibration generators and ultrasonic transducers for medical and industrial imaging. Fiber and component cost savings over current technologies, such as the `dice-and-fill' method for transducer production, and the range of unique structures possible with continuous VSSP PZT fiber are discussed. Recent results have yielded 1-3 type composites (25 vol% PZT) with d33 equals 340 pC/N, K equals 470, and g33 equals 80 mV/N, kt equals 0.54, kp equals 0.19, dh equals 50.1pC/N and gh equals 13 mV/N.
Theoretical L-shell Coster-Kronig energies 11 or equal to z or equal to 103
NASA Technical Reports Server (NTRS)
Chen, M. H.; Crasemann, B.; Huang, K. N.; Aoyagi, M.; Mark, H.
1976-01-01
Relativistic relaxed-orbital calculations of L-shell Coster-Kronig transition energies have been performed for all possible transitions in atoms with atomic numbers. Hartree-Fock-Slater wave functions served as zeroth-order eigenfunctions to compute the expectation of the total Hamiltonian. A first-order approximation to the local approximation was thus included. Quantum-electrodynamic corrections were made. Each transition energy was computed as the difference between results of separate self-consistent-field calculations for the initial, singly ionized state and the final two-hole state. The following quantities are listed: total transition energy, 'electric' (Dirac-Hartree-Fock-Slater) contribution, magnetic and retardation contributions, and contributions due to vacuum polarization and self energy.
Demagnetization using a determined estimated magnetic state
Denis, Ronald J; Makowski, Nathanael J
2015-01-13
A method for demagnetizing comprising positioning a core within the electromagnetic field generated by a first winding until the generated first electrical current is not substantially increasing, thereby determining a saturation current. A second voltage, having the opposite polarity, is then applied across the first winding until the generated second electrical current is approximately equal to the magnitude of the determined saturation current. The maximum magnetic flux within the core is then determined using the voltage across said first winding and the second current. A third voltage, having the opposite polarity, is then applied across the first winding until the core has a magnetic flux equal to approximately half of the determined maximum magnetic flux within the core.
Effects of oxide additions and temperature on sinterability of milled silicon nitride
NASA Technical Reports Server (NTRS)
Arias, A.
1980-01-01
Specimens of milled alpha-Si3N4 with 0 to 5.07 equivalent percent of oxide additions were pressureless sintered at 1650 to 1820 C for 4 hours in nitrogen while covered with powdered Si3N4 + SiO2. Densities of less than or equal to 97.5 percent resulted with approximately 2.5 equivalent percent of MgO, CeO2, Y2O3, and three mixtures involving these oxides. Densities of greater than or equal to 94 percent were obtained with approximately 0.62 equivalent percent of the same additives. At most temperatures, best sinterability (density maxima) was obtained with 1.2 to 2.5 equivalent percent additive.
Optical Studies of Nd-doped benzil, a potential luminescent and laser material.
Noginov, M A; Curley, M; Noginova, N; Wang, W S; Aggarwal, M D
1998-08-20
Neodymium-doped benzil crystals have been synthesized and characterized for their absorption, emission, and kinetics properties. From Judd-Ofelt analysis, the radiative decay time of Nd emission (peaking at 1055 nm) is estimated to be equal to 441 mus. The experimental Nd lifetime (under Ar+ laser excitation) is equal to 19 mus. The broad emission band centered at approximately 700 nm (tau(decay) approximately 15 ns) and the Raman scattering with characteristic frequency shift of 1600 cm(-1) have been observed at excitation of benzil with 532-nm Q-switched laser pulses. We show that rare-earth-doped benzil can be considered as a potential candidate for luminescent and solid-state laser material.
Failure behavior of glass ionomer cement under Hertzian indentation.
Wang, Yan; Darvell, B W
2008-09-01
To investigate the load-bearing capacity and failure mode of various types of glass ionomer cement (GIC) under Hertzian indentation, exploring the relationship between the failure behavior and formulation, and examining claims of filler-reinforcement of GIC. Discs 2mm thick, 10mm diameter, 8-18 replicates, were fabricated for two filler-reinforced GICs, four unmodified and unreinforced GICs, and four resin-modified GICs, with a dental silver amalgam and a filled-resin restorative material for comparison. Testing was at 23 degrees C, wet, after 7d storage at 37 degrees C in artificial saliva at pH 6, using a 20mm diameter hard steel ball and filled-nylon substrate (E: 10GPa). First failure was detected acoustically; mode was determined visually. At least 1/3 of specimens in each case were examined under scanning electronic microscope for corroboration. Reinforced and unmodified-unreinforced GICs were indistinguishable by failure load (one-way analysis of variance, P=0.425, overall 260+/-70N) and mode. Failure loads for resin-modified GICs were 360-1150N, amalgam approximately 680N, and filled resin approximately 1200N. Resin-modified GICs tended to be tougher (incomplete fracture), all others gave complete fracture (radial cracking). The stronger materials (two resin-modified GICs and filled resin) showed some cone cracking. While resin-modified GICs showed various extents of increase of failure load over that of the plain GICs, consistent with the hybrid chemistry, filler-reinforcement was not evident for the two claimed products, consistent with structural and theoretical expectations.
Hudak, Paul F
2018-02-01
A groundwater flow and mass transport model tested the capability of shallow excavations filled with coarse, reactive media to remediate a hypothetical unconfined aquifer with a maximum saturated thickness of 5 m. Modeled as contaminant sinks, the rectangular excavations were 10 m downgradient of an initial contaminant plume originating from a source at the top of the aquifer. The initial plume was approximately 259 m long, 23 m wide, and 5 m thick, with a downgradient tip located approximately 100 m upgradient of the site boundary. The smallest trench capable of preventing offsite migration was 11 m long (measured perpendicular to groundwater flow), 4 m wide (measured parallel to groundwater flow), and 3 m deep. Results of this study suggest that shallow trenches filled with coarse filter media that partially penetrate unconfined aquifers may be a viable alternative for remediating contaminated groundwater at some sites.
NASA Astrophysics Data System (ADS)
Botelho, S. J.; Bazylak, A.
2015-04-01
In this study, the microporous layer (MPL) of the polymer electrolyte membrane (PEM) fuel cell was analysed at the nano-scale. Atomic force microscopy (AFM) was utilized to image the top layer of MPL particles, and a curve fitting algorithm was used to determine the particle size and filling radius distributions for SGL-10BB and SGL-10BC. The particles in SGL-10BC (approximately 60 nm in diameter) have been found to be larger than those in SGL-10BB (approximately 40 nm in diameter), highlighting structural variability between the two materials. The impact of the MPL particle interactions on the effective thermal conductivity of the bulk MPL was analysed using a discretization of the Fourier equation with the Gauss-Seidel iterative method. It was found that the particle spacing and filling radius dominates the effective thermal conductivity, a result which provides valuable insight for future MPL design.
High temperature ablative foam
NASA Technical Reports Server (NTRS)
Liu, Matthew T. (Inventor)
1992-01-01
An ablative foam composition is formed of approximately 150 to 250 parts by weight polymeric isocyanate having an isocyanate functionality of 2.6 to 3.2; approximately 15 to 30 parts by weight reactive flame retardant having a hydroxyl number range from 200-260; approximately 10 to 40 parts by weight non-reactive flame retardant; approximately 10 to 40 parts by weight nonhydrolyzable silicone copolymer having a hydroxyl number range from 75-205; and approximately 3 to 16 parts by weight amine initiated polyether resin having an isocyanate functionality greater than or equal to 3.0 and a hydroxyl number range from 400-800.
NASA Astrophysics Data System (ADS)
Stoitsov, M. V.; Schunck, N.; Kortelainen, M.; Michel, N.; Nam, H.; Olsen, E.; Sarich, J.; Wild, S.
2013-06-01
We describe the new version 2.00d of the code HFBTHO that solves the nuclear Skyrme-Hartree-Fock (HF) or Skyrme-Hartree-Fock-Bogoliubov (HFB) problem by using the cylindrical transformed deformed harmonic oscillator basis. In the new version, we have implemented the following features: (i) the modified Broyden method for non-linear problems, (ii) optional breaking of reflection symmetry, (iii) calculation of axial multipole moments, (iv) finite temperature formalism for the HFB method, (v) linear constraint method based on the approximation of the Random Phase Approximation (RPA) matrix for multi-constraint calculations, (vi) blocking of quasi-particles in the Equal Filling Approximation (EFA), (vii) framework for generalized energy density with arbitrary density-dependences, and (viii) shared memory parallelism via OpenMP pragmas. Program summaryProgram title: HFBTHO v2.00d Catalog identifier: ADUI_v2_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADUI_v2_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GNU General Public License version 3 No. of lines in distributed program, including test data, etc.: 167228 No. of bytes in distributed program, including test data, etc.: 2672156 Distribution format: tar.gz Programming language: FORTRAN-95. Computer: Intel Pentium-III, Intel Xeon, AMD-Athlon, AMD-Opteron, Cray XT5, Cray XE6. Operating system: UNIX, LINUX, WindowsXP. RAM: 200 Mwords Word size: 8 bits Classification: 17.22. Does the new version supercede the previous version?: Yes Catalog identifier of previous version: ADUI_v1_0 Journal reference of previous version: Comput. Phys. Comm. 167 (2005) 43 Nature of problem: The solution of self-consistent mean-field equations for weakly-bound paired nuclei requires a correct description of the asymptotic properties of nuclear quasi-particle wave functions. In the present implementation, this is achieved by using the single-particle wave functions of the transformed harmonic oscillator, which allows for an accurate description of deformation effects and pairing correlations in nuclei arbitrarily close to the particle drip lines. Solution method: The program uses the axial Transformed Harmonic Oscillator (THO) single- particle basis to expand quasi-particle wave functions. It iteratively diagonalizes the Hartree-Fock-Bogoliubov Hamiltonian based on generalized Skyrme-like energy densities and zero-range pairing interactions until a self-consistent solution is found. A previous version of the program was presented in: M.V. Stoitsov, J. Dobaczewski, W. Nazarewicz, P. Ring, Comput. Phys. Commun. 167 (2005) 43-63. Reasons for new version: Version 2.00d of HFBTHO provides a number of new options such as the optional breaking of reflection symmetry, the calculation of axial multipole moments, the finite temperature formalism for the HFB method, optimized multi-constraint calculations, the treatment of odd-even and odd-odd nuclei in the blocking approximation, and the framework for generalized energy density with arbitrary density-dependences. It is also the first version of HFBTHO to contain threading capabilities. Summary of revisions: The modified Broyden method has been implemented, Optional breaking of reflection symmetry has been implemented, The calculation of all axial multipole moments up to λ=8 has been implemented, The finite temperature formalism for the HFB method has been implemented, The linear constraint method based on the approximation of the Random Phase Approximation (RPA) matrix for multi-constraint calculations has been implemented, The blocking of quasi-particles in the Equal Filling Approximation (EFA) has been implemented, The framework for generalized energy density functionals with arbitrary density-dependence has been implemented, Shared memory parallelism via OpenMP pragmas has been implemented. Restrictions: Axial- and time-reversal symmetries are assumed. Unusual features: The user must have access to the LAPACK subroutines DSYEVD, DSYTRF and DSYTRI, and their dependences, which compute eigenvalues and eigenfunctions of real symmetric matrices, the LAPACK subroutines DGETRI and DGETRF, which invert arbitrary real matrices, and the BLAS routines DCOPY, DSCAL, DGEMM and DGEMV for double-precision linear algebra (or provide another set of subroutines that can perform such tasks). The BLAS and LAPACK subroutines can be obtained from the Netlib Repository at the University of Tennessee, Knoxville: http://netlib2.cs.utk.edu/. Running time: Highly variable, as it depends on the nucleus, size of the basis, requested accuracy, requested configuration, compiler and libraries, and hardware architecture. An order of magnitude would be a few seconds for ground-state configurations in small bases N≈8-12, to a few minutes in very deformed configuration of a heavy nucleus with a large basis N>20.
Elnaggar, Sameh Y; Tervo, Richard; Mattar, Saba M
2014-05-01
A cavity (CV) with a dielectric resonator (DR) insert forms an excellent probe for the use in electron paramagnetic resonance (EPR) spectrometers. The probe's coupling coefficient, κ, the quality factor, Q, and the filling factor, η are vital in assessing the EPR spectrometer's performance. Coupled mode theory (CMT) is used to derive general expressions for these parameters. For large permittivity the dominating factor in κ is the ratio of the DR and CV cross sectional areas rather than the dielectric constant. Thus in some cases, resonators with low dielectric constant can couple much stronger with the cavity than do resonators with a high dielectric constant. When the DR and CV frequencies are degenerate, the coupled η is the average of the two uncoupled ones. In practical EPR probes the coupled η is approximately half of that of the DR. The Q of the coupled system generally depends on the eigenvectors, uncoupled frequencies (ω1,ω2) and the individual quality factors (Q1,Q2). It is calculated for different probe configurations and found to agree with the corresponding HFSS® simulations. Provided there is a large difference between the Q1, Q2 pair and the frequencies of DR and CV are degenerate, Q is approximately equal to double the minimum of Q1 and Q2. In general, the signal enhancement ratio, Iwithinsert/Iempty, is obtained from Q and η. For low loss DRs it only depends on η1/η2. However, when the DR has a low Q, the uncoupled Qs are also needed. In EPR spectroscopy it is desirable to excite only a single mode. The separation between the modes, Φ, is calculated as a function of κ and Q. It is found to be significantly greater than five times the average bandwidth. Thus for practical probes, it is possible to excite one of the coupled modes without exciting the other. The CMT expressions derived in this article are quite general and are in excellent agreement with the lumped circuit approach and finite numerical simulations. Hence they can also be applied to a loop-gap resonator in a cavity. For the design effective EPR probes, one needs to consider the κ, Q and η parameters. Copyright © 2014 Elsevier Inc. All rights reserved.
NASA Astrophysics Data System (ADS)
Elnaggar, Sameh Y.; Tervo, Richard; Mattar, Saba M.
2014-05-01
A cavity (CV) with a dielectric resonator (DR) insert forms an excellent probe for the use in electron paramagnetic resonance (EPR) spectrometers. The probe’s coupling coefficient, κ, the quality factor, Q, and the filling factor, η are vital in assessing the EPR spectrometer’s performance. Coupled mode theory (CMT) is used to derive general expressions for these parameters. For large permittivity the dominating factor in κ is the ratio of the DR and CV cross sectional areas rather than the dielectric constant. Thus in some cases, resonators with low dielectric constant can couple much stronger with the cavity than do resonators with a high dielectric constant. When the DR and CV frequencies are degenerate, the coupled η is the average of the two uncoupled ones. In practical EPR probes the coupled η is approximately half of that of the DR. The Q of the coupled system generally depends on the eigenvectors, uncoupled frequencies (ω1, ω2) and the individual quality factors (Q1, Q2). It is calculated for different probe configurations and found to agree with the corresponding HFSS® simulations. Provided there is a large difference between the Q1, Q2 pair and the frequencies of DR and CV are degenerate, Q is approximately equal to double the minimum of Q1 and Q2. In general, the signal enhancement ratio, I/Iempty, is obtained from Q and η. For low loss DRs it only depends on η1/η2. However, when the DR has a low Q, the uncoupled Qs are also needed. In EPR spectroscopy it is desirable to excite only a single mode. The separation between the modes, Φ, is calculated as a function of κ and Q. It is found to be significantly greater than five times the average bandwidth. Thus for practical probes, it is possible to excite one of the coupled modes without exciting the other. The CMT expressions derived in this article are quite general and are in excellent agreement with the lumped circuit approach and finite numerical simulations. Hence they can also be applied to a loop-gap resonator in a cavity. For the design effective EPR probes, one needs to consider the κ, Q and η parameters.
d'Ambrosio, E; Furano, A V
1987-01-01
An approximately equal to 150-bp GC-rich (approximately equal to 60%) region is at the right end of rat long interspersed repeated DNA (LINE or L1Rn) family members. We report here that one of the DNA strands from this region contains several non-palindromic sites that strongly arrest DNA synthesis in vitro by the prokaryotic Klenow and T4 DNA polymerases, the eukaryotic alpha polymerase, and AMV reverse transcriptase. The strongest arrest sites are G-rich (approximately equal to 70%) homopurine stretches of 18 or more residues. Shorter homopurine stretches (12 residues or fewer) did not arrest DNA synthesis even if the stretch contains 11/12 G residues. Arrest of the prokaryotic polymerases was not affected by their respective single strand binding proteins or polymerase accessory proteins. The region of duplex DNA which contains DNA synthesis arrest sites reacts with bromoacetaldehyde when present in negatively supercoiled molecules. By contrast, homopurine stretches that do not arrest DNA synthesis do not react with bromoacetaldehyde. The presence of bromoacetaldehyde-reactive bases in a G-rich homopurine-containing duplex under torsional stress is thought to be caused by base stacking in the homopurine strand. Therefore, we suggest that base-stacked regions of the template arrest DNA synthesis. Images PMID:2436148
The Bolocam Galactic Plane Survey
NASA Technical Reports Server (NTRS)
Glenn, Jason; Aguirre, James; Bally, John; Battersby, Cara; Bradley, Eric Todd; Cyganowski, Claudia; Dowell, Darren; Drosback, Meredith; Dunham, Miranda K.; Evans, Neal J., II;
2009-01-01
The Bolocam Galactic Plane Survey (BGPS) is a 1.1 millimeter continuum survey of the northern Galactic Plane made with Bolocam and the Caltech Submillimeter Observatory. The coverage totals 170 square degrees, comprised of a contiguous range from -10.5 deg is less than or equal to 90.5 deg, 0.5 deg is less than or equal to b is less than or equal to 0.5 deg, with extended coverage in b in selected regions, and four targeted regions in the outer Galaxy, including: IC1396, toward the Perseus arm at l is approximately 111 deg, W3/4/5, and Gem OB1. Depths of the maps range from 30 to 60 mJy beam (sup 1). Approximately 8,400 sources were detected and the maps and source catalog have been made publicly available. Millimeter-wave thermal dust emission reveals dense regions within molecular clouds, thus the BGPS serves as a database for studies of the dense interstellar medium and star formation within the Milky Way.
NASA Astrophysics Data System (ADS)
Hannam, Mark; Husa, Sascha; Ohme, Frank; Müller, Doreen; Brügmann, Bernd
2010-12-01
We present gravitational waveforms for the last orbits and merger of black-hole-binary systems along two branches of the black-hole-binary parameter space: equal-mass binaries with equal nonprecessing spins, and nonspinning unequal-mass binaries. The waveforms are calculated from numerical solutions of Einstein’s equations for black-hole binaries that complete between six and ten orbits before merger. Along the equal-mass spinning branch, the spin parameter of each black hole is χi=Si/Mi2∈[-0.85,0.85], and along the unequal-mass branch the mass ratio is q=M2/M1∈[1,4]. We discuss the construction of low-eccentricity puncture initial data for these cases, the properties of the final merged black hole, and compare the last 8-10 gravitational-wave cycles up to Mω=0.1 with the phase and amplitude predicted by standard post-Newtonian (PN) approximants. As in previous studies, we find that the phase from the 3.5PN TaylorT4 approximant is most accurate for nonspinning binaries. For equal-mass spinning binaries the 3.5PN TaylorT1 approximant (including spin terms up to only 2.5PN order) gives the most robust performance, but it is possible to treat TaylorT4 in such a way that it gives the best accuracy for spins χi>-0.75. When high-order amplitude corrections are included, the PN amplitude of the (ℓ=2,m=±2) modes is larger than the numerical relativity amplitude by between 2-4%.
Dynamic fractals in spatial evolutionary games
NASA Astrophysics Data System (ADS)
Kolotev, Sergei; Malyutin, Aleksandr; Burovski, Evgeni; Krashakov, Sergei; Shchur, Lev
2018-06-01
We investigate critical properties of a spatial evolutionary game based on the Prisoner's Dilemma. Simulations demonstrate a jump in the component densities accompanied by drastic changes in average sizes of the component clusters. We argue that the cluster boundary is a random fractal. Our simulations are consistent with the fractal dimension of the boundary being equal to 2, and the cluster boundaries are hence asymptotically space filling as the system size increases.
MIMO equalization with adaptive step size for few-mode fiber transmission systems.
van Uden, Roy G H; Okonkwo, Chigo M; Sleiffer, Vincent A J M; de Waardt, Hugo; Koonen, Antonius M J
2014-01-13
Optical multiple-input multiple-output (MIMO) transmission systems generally employ minimum mean squared error time or frequency domain equalizers. Using an experimental 3-mode dual polarization coherent transmission setup, we show that the convergence time of the MMSE time domain equalizer (TDE) and frequency domain equalizer (FDE) can be reduced by approximately 50% and 30%, respectively. The criterion used to estimate the system convergence time is the time it takes for the MIMO equalizer to reach an average output error which is within a margin of 5% of the average output error after 50,000 symbols. The convergence reduction difference between the TDE and FDE is attributed to the limited maximum step size for stable convergence of the frequency domain equalizer. The adaptive step size requires a small overhead in the form of a lookup table. It is highlighted that the convergence time reduction is achieved without sacrificing optical signal-to-noise ratio performance.
Thivierge, M C; Chouinard, P Y; Lévesque, J; Girard, V; Seoane, J R; Brisson, G J
1998-07-01
Ten Holstein cows in early lactation were used in a replicated 5 x 5 Latin square design to study the effects of MgO and three buffers added to diets containing Ca salts of canola oil fatty acids. Treatments were 1) control (basal diet; no buffer). 2) 1.1% NaHCO3 plus 1.1% KHCO3, 3) 1.9% NaHCO3, 4) 0.5% MgO, and 5) 2.0% Na sesquicarbonate (percentage of dry matter). The control diet contained 53% grass silage, 43% concentrate, and 4% Ca salts. Body weight, intake, milk yield, and percentages of milk fat, protein, and lactose were unaffected by treatments. Buffers and MgO tended to increase triacylglycerol extraction by the mammary gland and changed the proportions of some fatty acids in milk. Arterial concentrations of acetate and triacylglycerol were correlated with their respective arteriovenous differences. Extraction by the mammary gland was high for acetate (approximately equal to 58.2%), triacylglycerol (approximately equal to 47.3%) propionate (approximately equal to 34.6%), and glucose (approximately equal to 24.3%). Extraction of free fatty acids, phospholipids, or cholesterol was negligible. Mammary triacylglycerol arteriovenous difference tended to be higher than when MgO was fed than when NaHCO3 was fed. Sodium sesquicarbonate, NaHCO3, and the blend of bicarbonate buffers increased C18:2 in milk fat when compared with the control treatment. The concentration of C18:2 in milk fat decreased when MgO was fed, but the ratio of cis-C18:1 to trans-C18:1 increased compared with effects of dietary NaHCO3. Medium-chain fatty acids in milk fat tended to be higher than Na sesquicarbonate than with NaHCO3. Buffers and MgO modified the profiles of fatty acids in milk.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Amatucci, W.E.
1994-01-01
This laboratory investigation documents the influence of transverse, localized, dc electric fields (TLE) on the excitation of ion-cyclotron waves driven by magnetic field-aligned current (FAC) in a Q-machine plasma device. A segmented disk electrode, located on axis at the end of the plasma column, is used to independently control TLE and FAC in the plasma (potassium plasma, n approximately equals 10(exp 9) cm(exp {minus}3), rho(i) approximately equals 0.2 cm, T(e) = T(i) approximately equals 0.2 eV). Ion-cyclotron waves have been characterized in both the weak-TLE and large-FAC regime and the strong-TLE and small-FAC regime. The existence of a new categorymore » of oscillation identified as the inhomogeneous energy-density driven (IEDD) instability is verified based on the properties of the waves in the latter regime. In the weak-TLE regime, current-driven electrostatic ion-cyclotron (CDEIC) waves with features in qualitative agreement with previous laboratory results have been observed at sufficiently large FAC. These waves have a frequency spectrum with a single narrow spectral feature located slightly above the ion-cyclotron frequency (omega approximately equals 1.2 Omega(i)). The waves are standing in the radial direction with peak oscillation amplitude located in the center of the FAC channel and are azimuthally symmetric (m = 0). Small magnitude TLE were found to have negligible effect on the characteristics of the waves. In the strong-TLE regime, a decrease in the threshold FAC level is observed. This transition in the instability threshold is accompanied by changes in the frequency spectra, propagation characteristics, and mode amplitude profiles. In the presence of strong-TLE, the ion-cyclotron waves propagate azimuthally in the E x B direction with k(theta) rho(i) = 0.4 and m = 1. The frequency spectrum becomes broadband and spiky, and shifts with the applied TLE strength.« less
On singlet s-wave electron-hydrogen scattering.
NASA Technical Reports Server (NTRS)
Madan, R. N.
1973-01-01
Discussion of various zeroth-order approximations to s-wave scattering of electrons by hydrogen atoms below the first excitation threshold. The formalism previously developed by the author (1967, 1968) is applied to Feshbach operators to derive integro-differential equations, with the optical-potential set equal to zero, for the singlet and triplet cases. Phase shifts of s-wave scattering are computed in the zeroth-order approximation of the Feshbach operator method and in the static-exchange approximation. It is found that the convergence of numerical computations is faster in the former approximation than in the latter.
2011-04-14
characteristics in many locations and consequently most of the base has been mapped as disturbed urban land complexes. Major soil complexes represented...at WPAFB include: Warsaw-Fill land complex, Sloan-Fill land complex, Miamian- Urban land complex, Fox- Urban land complex, Linwood Muck, Westland- Urban ...land complex, and Warsaw- Urban land complex. 3.6.1 Proposed Action The project area for the alternative includes approximately 3.7 acres of property
Angular Motion of a Spinning Projectile with a Viscous Liquid Payload
1982-08-01
with the external moments neglected. (I + 1 L ) - i$(I +1 x) = (2.9) y L) x Lx 11. C. 11. A,.pWThz, " influence of MA’oovin ,Tter•z’aria’i8 on Angular...viscous influence of the lateral wall exactly without the use of a boundary layer approximation. Its results for fully-filled cyl- inders should...Tner’tial ,•,rm on the Free Fligtht Motion of a Body Conacziinng Several L*.,,Wentrictalv ! Located, Liq:did- Filled Cylinders," BRL Report 1551, September
2008-04-10
CAPE CANAVERAL, Fla. -- On a beach on NASA's Kennedy Space Center, more than 130 volunteers from the joint NASA’s Kennedy Space Center and U.S. Fish and Wildlife Service contract organizations give up their afternoon to gather all the “unnatural” items that had accumulated on 6.1 miles of central Florida east coast shoreline during the past 12 months. Part of the center's dedication to a clean environment, volunteers gathered enough trash to fill approximately 450 garbage bags and enough recyclable plastic and glass to fill 150 bags. Photo credit: NASA/Dimitri Gerondidakis
2008-04-10
CAPE CANAVERAL, Fla. -- On a beach on NASA's Kennedy Space Center, more than 130 volunteers from the joint NASA’s Kennedy Space Center and U.S. Fish and Wildlife Service contract organizations give up their afternoon to gather all the “unnatural” items that had accumulated on 6.1 miles of central Florida east coast shoreline during the past 12 months. Part of the center's dedication to a clean environment, volunteers gathered enough trash to fill approximately 450 garbage bags and enough recyclable plastic and glass to fill 150 bags. Photo credit: NASA/Dimitri Gerondidakis
2008-04-10
CAPE CANAVERAL, Fla. -- On a beach on NASA's Kennedy Space Center, more than 130 volunteers from the joint NASA’s Kennedy Space Center and U.S. Fish and Wildlife Service contract organizations give up their afternoon to gather all the “unnatural” items that had accumulated on 6.1 miles of central Florida east coast shoreline during the past 12 months. Part of the center's dedication to a clean environment, volunteers gathered enough trash to fill approximately 450 garbage bags and enough recyclable plastic and glass to fill 150 bags. Photo credit: NASA/Dimitri Gerondidakis
2008-04-10
CAPE CANAVERAL, Fla. -- On a beach on NASA's Kennedy Space Center, more than 130 volunteers from the joint NASA’s Kennedy Space Center and U.S. Fish and Wildlife Service contract organizations give up their afternoon to gather all the “unnatural” items that had accumulated on 6.1 miles of central Florida east coast shoreline during the past 12 months. Part of the center's dedication to a clean environment, volunteers gathered enough trash to fill approximately 450 garbage bags and enough recyclable plastic and glass to fill 150 bags. Photo credit: NASA/Dimitri Gerondidakis
Organizational barriers and ethnicity in the Scottish NHS.
Sheffield, J; Hussain, A; Coleshill, P
1999-01-01
The NHS faces a crisis in terms of staffing and recruitment. Many of the ethnic minority GPs in inner city areas throughout the UK are coming up to retirement age, and there is an insufficient supply of trainees to fill estimated vacancies. Over 2,000 nursing vacancies exist across the UK, and recruitment to the profession and retention within the profession are poor. Nurses have been recruited from overseas for the past 40 years, and are currently being recruited from Finland, Malaysia, and the West Indies, whilst doctors are being sought in India, Pakistan and Africa. Overseas recruitment is not a new phenomenon, and numerous studies have been carried out to examine equal opportunities and racial discrimination within the NHS. The aim of this paper was to examine ethnicity and equal opportunities within the Scottish NHS and record the levels of organisational awareness of ethnicity and equal opportunities' issues. The paper also examines the link between health service delivery to ethnic minorities and internal cultural attitudes to staff.
Atrioventricular nonuniformity of pericardial constraint.
Hamilton, Douglas R; Sas, Rozsa; Tyberg, John V
2004-10-01
Physiologists and clinicians commonly refer to "pressure" as a measure of the constraining effects of the pericardium; however, "pericardial pressure" is really a local measurement of epicardial radial stress. During diastole, from the bottom of the y descent to the beginning of the a wave, pericardial pressure over the right atrium (P(pRA)) is approximately equal to that over the right ventricle (P(pRV)). However, in systole, during the interval between the bottom of the x descent and the peak of the v wave, these two pericardial pressures appear to be completely decoupled in that P(pRV) decreases, whereas P(pRA) remains constant or increases. This decoupling indicates considerable mechanical independence between the RA and RV during systole. That is, RV systolic emptying lowers P(pRV), but P(pRA) continues to increase, suggesting that the relation of the pericardium to the RA must allow effective constraint, even though the pericardium over the RV is simultaneously slack. In conclusion, we measured the pericardial pressure responsible for the previously reported nonuniformity of pericardial strain. P(pRA) and P(pRV) are closely coupled during diastole, but during systole they become decoupled. Systolic nonuniformity of pericardial constraint may augment the atrioventricular valve-opening pressure gradient in early diastole and, so, affect ventricular filling.
Temporal and spatial evolution of nanosecond microwave-driven plasma
NASA Astrophysics Data System (ADS)
Chang, C.; Chen, X. Q.; Zhu, M.; Pu, Y. K.
2018-06-01
In this paper, a method for simultaneously acquiring the temporal and spatial evolution of characteristic plasma spectra in a single microwave pulse is proposed and studied. By using multi-sub-beam fiber bundles coupled with a spectrometer and EMICCD (Electron-multiplying intensified charge-coupled device), the spatial distribution and time evolution of characteristic spectra of desorbed gases at the dielectric/vacuum interface during nanosecond microwave-driven plasma discharge are observed. Arrays of small align tubes punctured with metal walls of feed horn are filled with separate fibers of matched sizes and equal lengths. The output ends of fibers arranged in a single longitudinal column are connected to the entrance slit of a spectrometer, where the optical spectrum inputs to a high-speed EMICCD, to detect the rapid-varying time and space spectra of nanosecond giga-watt microwave discharges. The evolution of spectral clusters of N2 (C-B), N2+ (B-X), and the hydrogen atoms is discovered and monitored. The whole duration of light emission is much longer than the microwave pulse, and the intensities of ion N2+ (B-X) spectra increase after microwave pulses with rise times of 25-50 ns. The brightness distribution of plasma spectra in different space is observed and approximately consistent with the simulated E-field distribution.
NASA Technical Reports Server (NTRS)
2004-01-01
Topics covered include: 1) Advanced Signal Conditioners for Data-Acquisition Systems; 2) Downlink Data Multiplexer; 3) Viewing ISS Data in Real Time via the Internet; 4) Autonomous Environment-Monitoring Networks; 5) Readout of DSN Monitor Data; 6) Parallel-Processing Equalizers for Multi-Gbps Communications; 7) AIN-Based Packaging for SiC High-Temperature Electronics; 8) Software for Optimizing Quality Assurance of Other Software; 9) The TechSat 21 Autonomous Sciencecraft Experiment; 10) Software for Analyzing Laminar-to-Turbulent Flow Transitions; 11) Elastomer Filled With Single-Wall Carbon Nanotubes; 12) Modifying Ship Air-Wake Vortices for Aircraft Operations; 13) Strain-Gauge Measurement of Weight of Fluid in a Tank; 14) Advanced Docking System With Magnetic Initial Capture; 15) Blade-Pitch Control for Quieting Tilt-Rotor Aircraft; 16) Solar Array Panels With Dust-Removal Capability; 17) Aligning Arrays of Lenses and Single-Mode Optical Fibers; 18) Automatic Control of Arc Process for Making Carbon Nanotubes; 19) Curved-Focal-Plane Arrays Using Deformed-Membrane Photodetectors; 20) Role of Meteorology in Flights of a Solar-Powered Airplane; 21) Model of Mixing Layer With Multicomponent Evaporating Drops; 22) Solution-Assisted Optical Contacting; 23) Improved Discrete Approximation of Laplacian of Gaussian; 24) Utilizing Expert Knowledge in Estimating Future STS Costs; 25) Study of Rapid-Regression Liquefying Hybrid Rocket Fuels; and 26) More About the Phase-Synchronized Enhancement Method.
Smouldering Remediation (STAR) Technology: Field Pilot Tests and First Full Scale Application
NASA Astrophysics Data System (ADS)
Gerhard, J.; Kinsman, L.; Torero, J. L.
2015-12-01
STAR (Self-sustaining Treatment for Active Remediation) is an innovative remediation technology based on the principles of smoldering combustion where the contaminants are the fuel. The self-sustaining aspect means that a single, local ignition event can result in many days of contaminant destruction in situ. Presented research to date has focused on bench scale experiments, numerical modelling and process understanding. Presented here is the maturation of the in situ technology, including three field pilot tests and a full-scale implementation to treat coal tar-impacted soils. The first pilot determined a Radius of Influence (ROI) for a single ignition of approximately eight feet with an average propagation rate of the reaction of approximately one foot per day. TPH concentrations in soils were reduced from 10,000 milligrams per kilogram to a few hundred milligrams per kilogram. The second pilot was conducted in an area of significant void spaces created through the anthropogenic deposition of clay bricks and tiles. The void spaces led to pre-mature termination of the combustion reaction, limiting ROI and the effectiveness of the technology in this setting. The third case study involved the pilot testing, design, and full-scale implementation of STAR at a 37-acre former chemical manufacturing facility. Three phases of pilot testing were conducted within two hydrogeologic units at the site (i.e., surficial fill and deep alluvial sand units). Pilot testing within the fill demonstrated self-sustained coal tar destruction rates in excess of 800 kg/day supported through air injection at a single well. Deep sand unit testing (twenty-five feet below the water table) resulted in the treatment of a targeted six-foot layer of impacted fine sands to a radial distance of approximately twelve feet. These results (and additional parameters) were used to develop a full-scale STAR design consisting of approximately 1500 surficial fill ignition points and 500 deep sand ignition points and two treatment (air distribution and vapor collection / treatment) systems to remediate an approximately 14-acre footprint of contaminated soils within the project timelines (i.e., by mid-2016). Field activities began in 2014 and progress is currently on-schedule.
Nakai, Masaaki; Niinomi, Mitsuo; Ishii, Daisuke
2011-10-01
Porous titanium (pTi) can possess a low Young's modulus equal to that of human bone, depending on its porosity. However, the mechanical strength of pTi deteriorates greatly with increasing porosity. On the other hand, certain medical polymers exhibit biofunctionalities, which are not possessed intrinsically by metallic materials. Therefore, a biodegradable medical polymer, poly-L-lactic acid (PLLA), was used to fill in the pTi pores using a modified in-situ polymerization technique. The mechanical and biodegradable properties of pTi filled with PLLA (pTi/PLLA) as fabricated by this technique and the effects of the PLLA filling were evaluated in this study. The pTi pores are almost completely filled with PLLA by the developed process (i.e., technique). The tensile strength and tensile Young's modulus of pTi barely changes with the PLLA filling. However, the PLLA filling improves the compressive 0.2% proof stress of pTi having any porosity and increases the compressive Young's modulus of pTi having relatively high porosity. This difference between the tensile and compressive properties of pTi/PLLA is considered to be caused by the differing resistances of PLLA in the pores to tensile and compressive deformations. The PLLA filled into the pTi pores degrades during immersion in Hanks' solution at 310 K. The weight loss due to PLLA degradation increases with increasing immersion time. However, the rate of weight loss of pTi/PLLA during immersion decreases with increasing immersion time. Hydroxyapatite formation is observed on the surface of pTi/PLLA after immersion for ≥8 weeks. The decrease in the weight-loss rate may be caused by weight gain due to hydroxyapatite formation and/or the decrease in contact area with Hanks' solution caused by its formation on the surface of pTi/PLLA. Copyright © 2011 Elsevier Ltd. All rights reserved.
Improved Apparatus for Measuring Distance Between Axles
NASA Technical Reports Server (NTRS)
Willard, Douglas E.; Townsend, Ivan I., III
2003-01-01
An improved version of an optoelectronic apparatus for measuring distances of the order of tens of feet with an error no larger than a small fraction of an inch (a few millimeters) has been built. Like the previous version, the present improved version of the apparatus is designed to measure the distance approximately equal to 66 ft (approximately equal to 20 m) between the axes of rotation of the front and rear tires of the space shuttle orbiter as it rests in a ground-based processing facility. Like the previous version, the present version could also be adapted for similar purposes in other settings: Examples include measuring perpendicular distance from a wall in a building, placement of architectural foundations, and general alignment and measurement operations.
NASA Technical Reports Server (NTRS)
Ajello, M.; Albert, A.; Anderson, B.; Baldini, L.; Barbiellini, G.; Bastieri, D.; Bellazzini, R.; Bissaldi, E.; Blandford, R.D.; Mirabal, N.;
2016-01-01
We report on the search for spectral irregularities induced by oscillations between photons and axion-like particles (ALPs) in the gamma-ray spectrum of NGC 1275, the central galaxy of the Perseus cluster. Using 6 years of Fermi Large Area Telescope data, we find no evidence for ALPs and exclude couplings above 5 times 10 (sup -12) per gigaelectronvolt for ALP masses less than or approximately equal to 0.5 apparent magnitude (m (sub a)) less than or approximately equal to 5 nanoelectronvolts at 95 percent confidence. The limits are competitive withthe sensitivity of planned laboratory experiments, and, together with other bounds, strongly constrain thepossibility that ALPs can reduce the gamma-ray opacity of the Universe.
Observations on the effects of image processing functions on fingermark data in the Fourier domain
NASA Astrophysics Data System (ADS)
Bramble, Simon K.; Fabrizi, Paola M.
1995-09-01
One of the image processing functions used for the enhancement of laten fingermark images is the Fourier transform. This paper describes some effects of spatial resolution, zero-filling and windowing on fingermark data in the Fourier domain. It is shown that with an understanding of the fingermark structure it is possible to determine the approximate prosition of the frequency data in the Fourier domain corresponding to the fingermark image detail. The effect of attenuation of frequency data on a zero-filled image is shown to be different to the same attenuation on a non-zero-filled image. The effects of windowing spatial data on the frequency data are also highlighted and compared with the same data after the application of a Hanning window.
SOCIAL DETERMINANTS OF LOW FERTILITY IN BRAZIL.
Castanheira, Helena Cruz; Kohler, Hans-Peter
2017-11-01
An increasing number of developing countries are experiencing below replacement fertility rates. Although the factors associated with low fertility in developed countries have been widely explored in the literature, studies of low fertility in middle- and low-income countries continue to be rare. To help fill this gap, Brazil was used as a case study to assess whether human development, gender equality and the ability of mothers with young children to work are associated with the likelihood of married or cohabiting women to have a child. For this purpose, multilevel logistic regressions were estimated using the 1991, 2000 and 2010 Brazilian Demographic Censuses. It was found that human development was negatively associated with fertility in the three periods analysed. Gender equality and the ability of mothers with young children to work were positively associated with the odds of having higher order births in Brazil in 2000 and 2010. In 1991, these variables were not associated with higher order births, and gender equality was negatively associated with first births. The positive association found in 2000 and 2010 may constitute a reversal of the relationship that in all likelihood prevailed earlier in the demographic transition when gender equality was most likely negatively correlated with fertility levels.
NASA Astrophysics Data System (ADS)
Kim, Jae-Sung; Chung, Jin-Beom; Kim, In-Ah; Eom, Keun-Yong
2013-10-01
We used an endorectal balloon (ERB) for prostate immobilization during intensity-modulated radiotherapy (IMRT) for prostate cancer treatment. To investigate the dosimetric effects of ERB-filling materials, we changed the ERB Hounsfield unit (HU) from 0 to 1000 HU in 200-HU intervals to simulate the various ERB fillings; 0 HU simulated a water-filled ERB, and 1000 HU simulated the densest material-filled ERB. Dosimetric data (coverage, homogeneity, conformity, maximal dose, and typical volume dose) for the tumor and the organs at risk (OARs) were evaluated in prostate IMRT treatment plans with 6-MV and 15-MV beams. The tumor coverage appeared to differ by approximately 1%, except for the clinical target volume (CTV) V100% and the planning target volume (PTV) V100%. The largest difference for the various ERB fillings was observed in the PTV V100%. In spite of increasing HU, the prostate IMRT plans at both energies had relatively low dosimetric effects on the PTV and the CTV. However, the maximal and the typical volume doses (D25%, D30%, and D50%) to the rectal wall and the bladder increased with increasing HU. For an air-filled ERB, the maximal doses to the rectal wall and the monitor units were lower than the corresponding values for the water-filled and the densest material-filled ERBs. An air-filled ERB spared the rectal wall because of its dosimetric effect. Thus, we conclude that the use of an air-filled ERB provides a dosimetric benefit to the rectal wall without a loss of target coverage and is an effective option for prostate IMRT treatment.
Research notes : soil nailing of a bridge fill embankment.
DOT National Transportation Integrated Search
1991-11-01
A recent construction project involved widening and lowering the grade of the Swift Highway under the south end of the Oregon Slough Bridge approximately seven miles north of Portland. This project included construction of the first permanent soil na...
CTC1-mediated C-strand fill-in is an essential step in telomere length maintenance
Feng, Xuyang; Hsu, Shih-Jui; Kasbek, Christopher; Chaiken, Mary
2017-01-01
Abstract To prevent progressive telomere shortening as a result of conventional DNA replication, new telomeric DNA must be added onto the chromosome end. The de novo DNA synthesis involves elongation of the G-rich strand of the telomere by telomerase. In human cells, the CST complex (CTC1-STN1-TEN1) also functions in telomere replication. CST first aids in duplication of the telomeric dsDNA. Then after telomerase has extended the G-rich strand, CST facilitates fill-in synthesis of the complementary C-strand. Here, we analyze telomere structure after disruption of human CTC1 and demonstrate that functional CST is essential for telomere length maintenance due to its role in mediating C-strand fill-in. Removal of CTC1 results in elongation of the 3΄ overhang on the G-rich strand. This leads to accumulation of RPA and telomeric DNA damage signaling. G-overhang length increases with time after CTC1 disruption and at early times net G-strand growth is apparent, indicating telomerase-mediated G-strand extension. In contrast, C-strand length decreases continuously, indicating a deficiency in C-strand fill-in synthesis. The lack of C-strand maintenance leads to gradual shortening of the telomeric dsDNA, similar to that observed in cells lacking telomerase. Thus, telomerase-mediated G-strand extension and CST-mediated C-strand fill-in are equally important for telomere length maintenance. PMID:28334750
Study, Design and Fabricate a Cold Crucible System
1975-03-31
Fritz iuettinger Blektronik GmbH, Freiburg, Germany) tuned to operate at approximately 4 megahertz. Using kilogram charges of zirconia powder , densification...ut’. rho skull was filled with stabilized zirconia powder and approximate’Iy 10 grams of zirconium metal chips (1/8" diameter) were buried In the...show the results of Run M-tO. A 700 gram zirconia powder charge (Johnson Matthey Chemicals, Ltd., 99.992 purity) was used with 10 wt % yttria (Rare Earth
DOE Office of Scientific and Technical Information (OSTI.GOV)
Pulham, A.; Edward, W.; App, J.
1996-12-31
The Cusiana Field is located in the Llanos Foothills of Eastern Colombia. The principal reservoir is the late Eocene Mirador Formation which comprises >50% of reserves. Currently the Mirador reservoir is providing nearly all of the 150,00bopd of production from the Cusiana Field. The Mirador reservoir comprises a stack of incised valley deposits. The fills of the valleys are dominated by quartz arenite sandstones. The average porosity of the valley sandstones is 8% which reflects abundant quartz cement ({approximately}14%) and significant compaction during deep burial ({approximately}20,000feet). Single valleys are up to 70 feet thick and exhibit a distinctive bipartite fillmore » that reflects changing energy conditions during filling. Bases of valleys have the coarsest grain size and have sedimentological and trace fossil evidence for deposition in highly stressed, brackish water environments. The upper parts of the valleys are typically finer grained and were deposited in more saline settings. Despite the low porosity of the Mirador valleys, drill stem tests and production log data show that they have phenomenal performance characteristics. Rates of {ge}10,000bopd are achieved from single valleys. Bases of the valley fills are the key contributors to flow. Integration of detailed core and pore system analysis with the reservoir performance data shows that the permeability fabric of the Mirador can be explained by original depositional architecture and simple loss of primary porosity. Comparison of Cusiana with other quartz-rich sandstones from around the world suggests that it`s low porosity/high performance is predictable.« less
USSR Report, Consumer Goods and Domestic Trade, No. 77.
1983-10-24
above all to the prices of clothing, knitwear and other products manufactured by consumer service enterprises on custom or- der for individuals. In...light of the fact that filling custom orders is more time- consuming , other things being equal, than large-scale industrial produc- tion of the same...340033 JPRS 84592 24 October 1983 USSR Report CONSUMER GOODS AND DOMESTIC TRADE No. 77 flätöltö FBIS FOREIGN BROADCAST INFORMATION SERVICE
NASA Technical Reports Server (NTRS)
Tabacco, Mary Beth; Zhou, Quan
1993-01-01
Porous optical fibers include sensing regions filled with reagents. Optical-fiber chemical sensors (optrodes) developed to measure concentrations of ethylene in air in enclosed artificial plant-growth environments. Such measurements needed because ethylene acts as plant-growth hormone affecting growth at concentrations less than or equal to 20 parts per billion. Optrodes small, but exhibit sensitivities comparable to those of larger instruments. Operated safely in potentially explosive atmospheres and neither cause, nor susceptible to, electrical interference at suboptical frequencies.
Low-Density, Aerogel-Filled Thermal-Insulation Tiles
NASA Technical Reports Server (NTRS)
Santos, Maryann; Heng, Vann; Barney, Andrea; Oka, Kris; Droege, Michael
2005-01-01
Aerogel fillings have been investigated in a continuing effort to develop low-density thermal-insulation tiles that, relative to prior such tiles, have greater dimensional stability (especially less shrinkage), equal or lower thermal conductivity, and greater strength and durability. In preparation for laboratory tests of dimensional and thermal stability, prototypes of aerogel-filled versions of recently developed low-density tiles have been fabricated by impregnating such tiles to various depths with aerogel formations ranging in density from 1.5 to 5.6 lb/ft3 (about 53 to 200 kg/cu m). Results available at the time of reporting the information for this article showed that the thermal-insulation properties of the partially or fully aerogel- impregnated tiles were equivalent or superior to those of the corresponding non-impregnated tiles and that the partially impregnated tiles exhibited minimal (<1.5 percent) shrinkage after multiple exposures at a temperature of 2,300 F (1,260 C). Latest developments have shown that tiles containing aerogels at the higher end of the density range are stable after multiple exposures at the said temperature.
Determination of absorption coefficient based on laser beam thermal blooming in gas-filled tube.
Hafizi, B; Peñano, J; Fischer, R; DiComo, G; Ting, A
2014-08-01
Thermal blooming of a laser beam propagating in a gas-filled tube is investigated both analytically and experimentally. A self-consistent formulation taking into account heating of the gas and the resultant laser beam spreading (including diffraction) is presented. The heat equation is used to determine the temperature variation while the paraxial wave equation is solved in the eikonal approximation to determine the temporal and spatial variation of the Gaussian laser spot radius, Gouy phase (longitudinal phase delay), and wavefront curvature. The analysis is benchmarked against a thermal blooming experiment in the literature using a CO₂ laser beam propagating in a tube filled with air and propane. New experimental results are presented in which a CW fiber laser (1 μm) propagates in a tube filled with nitrogen and water vapor. By matching laboratory and theoretical results, the absorption coefficient of water vapor is found to agree with calculations using MODTRAN (the MODerate-resolution atmospheric TRANsmission molecular absorption database) and HITRAN (the HIgh-resolution atmospheric TRANsmission molecular absorption database).
DOE Office of Scientific and Technical Information (OSTI.GOV)
Fang, Jun; Burghardt, Wesley R.; Bubeck, Robert A.
The development of molecular orientation in thermotropic liquid crystalline polymers (TLCPs) during injection molding has been investigated using two-dimensional wide-angle X-ray scattering coordinated with numerical computations employing the Larson-Doi polydomain model. Orientation distributions were measured in 'short shot' moldings to characterize structural evolution prior to completion of mold filling, in both thin and thick rectangular plaques. Distinct orientation patterns are observed near the filling front. In particular, strong extension at the melt front results in nearly transverse molecular alignment. Far away from the flow front shear competes with extension to produce complex spatial distributions of orientation. The relative influence ofmore » shear is stronger in the thin plaque, producing orientation along the filling direction. Exploiting an analogy between the Larson-Doi model and a fiber orientation model, we test the ability of process simulation tools to predict TLCP orientation distributions during molding. Substantial discrepancies between model predictions and experimental measurements are found near the flow front in partially filled short shots, attributed to the limits of the Hele-Shaw approximation used in the computations. Much of the flow front effect is however 'washed out' by subsequent shear flow as mold filling progresses, leading to improved agreement between experiment and corresponding numerical predictions.« less
NASA Technical Reports Server (NTRS)
Sandholt, P. E.; Farrugia, C. J.; Burlaga, L. F.; Holtet, J. A.; Moen, J.; Lybekk, B.; Jacobsen, B.; Opsvik, D.; Egeland, A.; Lepping, R.
1994-01-01
Continuous optical observations of cusp/cleft auroral activities within approximately equal to 09-15 MLT and 70-76 deg magnetic latitude are studied in relation to changes in solar wind dynamic pressure and interplanetary magnetic field (IMF) variability. The observed latitudinal movements of the cusp/cleft aurora in response to IMF B(sub z) changes may be explained as an effect of a variable magnetic field intensity in the outer dayside magnetosphere associated with the changing intensity of region 1 field-aligned currents and associated closure currents. Ground magnetic signatures related to such currents were observed in the present case (January 10, 1993). Strong, isolated enhancements in solar wind dynamic pressure (Delta p/p is greater than or equal to 0.5) gave rise to equatorward shifts of the cusp/cleft aurora, characteristic auroral transients, and distinct ground magnetic signatures of enhanced convection at cleft latitudes. A sequence of auroral events of approximately equal to 5-10 min recurrence time, moving eastward along the poleward boundary of the persistent cusp/cleft aurora in the approximately equal to 10-14 MLT sector, during negative IMF B(sub z) and B(sub y) conditions, were found to be correlated with brief pulses in solar wind dynamic pressure (0.1 is less than Delta p/p is less than 0.5). Simultaneous photometer observations from Ny Alesund, Svalbard, and Danmarkshavn, Greenland, show that the events often appeared on the prenoon side (approximately equal to 10-12 MLT), before moving into the postnoon sector in the case we study here, when IMF B(sub y) is less than 0. In other cases, similar auroral event sequences have been observed to move westward in the prenoon sector, during intervals of positive B(sub y). Thus a strong prenoon/postnoon asymmetry of event occurence and motion pattern related to the IMF B(sub y) polarity is observed. We find that this category of auroral event sequence is stimulated bursts of electron precipitation that originate from magnetosheath plasma that has accessed that dayside magnetosphere in the noon or near-noon sector, possibly at high latitudes, partly governed by the IMF orientation as well as by solar wind dynamic pressure pulses.
Game of Life on the Equal Degree Random Lattice
NASA Astrophysics Data System (ADS)
Shao, Zhi-Gang; Chen, Tao
2010-12-01
An effective matrix method is performed to build the equal degree random (EDR) lattice, and then a cellular automaton game of life on the EDR lattice is studied by Monte Carlo (MC) simulation. The standard mean field approximation (MFA) is applied, and then the density of live cells is given ρ=0.37017 by MFA, which is consistent with the result ρ=0.37±0.003 by MC simulation.
Cuspal Deflection of Premolars Restored with Bulk-Fill Composite Resins.
Behery, Haytham; El-Mowafy, Omar; El-Badrawy, Wafa; Saleh, Belal; Nabih, Sameh
2016-01-01
This in vitro study compared cuspal deflection of premolars restored with three bulk-fill composite resins to that of incrementally-restored ones with a low-shrinkage silorane-based restorative material. Forty freshly-extracted intact human upper premolars were used. Reference points at buccal and palatal cusp tips were acid-etched and composite rods were horizontally bonded to them (TPH-Spectra-HV, Dentsply). Two acrylic resin guiding paths were made for each premolar to guide beaks of a digital micrometer used for cuspal deflection measurements. Standardized MOD cavities, 3 mm wide bucco-lingually and 3.5 mm deep, were prepared on each premolar. Prepared teeth were then equally divided into four groups (n = 10) and each group was assigned to one of four composite resin (QuiXX, Dentsply; X-tra fil, Voco; Tetric EvoCeram Bulk Fill, Ivoclar Vivadent; low-shrinkage Filtek LS, 3M/ESPE). Adper Single Bond-Plus, 3M/ESPE was used with all bulk-fill restoratives. LS-System Adhesive, 3M/ESPE was used with Filtek LS. For each prepared premolar, cuspal deflection was measured in microns as the difference between two readings between reference points before and after restoration completion. Means and SDs were calculated and data statistically-analyzed using One-way ANOVA and Tukey's test. Filtek LS showed the lowest mean cuspal deflection value 6.4(0.84)μm followed by Tetric EvoCeram Bulk Fill 10.1(1.2) μm and X-tra fil 12.4(1.35)μm, while QuiXX showed the highest mean 13(1.05)μm. ANOVA indicated significant difference among mean values of groups (p < 0.001). Tukey's test indicated no significant difference in mean values between QuiXX and X-tra fil (p = 0.637). Tetric EvoCeram Bulk Fill had significantly lower mean cuspal deflection compared with the two other bulk-fill composite resins tested. Filtek LS had the lowest significant mean cuspal deflection in comparison to all tested bulk-fill restoratives. The use of Tetric EvoCeram Bulk fill composite resin restorative for class II MOD cavities resulted in reduced cuspal deflection in comparison to the two other bulk-fill composite resins tested. The silorane-based Filtek LS restorative resulted in the least cuspal deflection in comparison to all tested bulk-fill composite restoratives. © 2016 Wiley Periodicals, Inc.
A Multi-Epoch Timing and Spectral Study of the Ultraluminous X-Ray NGC 5408 X-1 with XMM-Newton
NASA Technical Reports Server (NTRS)
Dheeraj, Pasham; Strohmayer, Tod E.
2012-01-01
We present results of new XMM-Newton observations of the ultraluminous X-ray source (ULX) NGC 5408 X-1, one of the few ULXs to show quasi-periodic oscillations (QPOs). We detect QPOs in each of four new (approximately equal to 100 ks) pointings, expanding the range of frequencies observed from 10 to 40 mHz. We compare our results with the timing and spectral correlations seen in stellar-mass black hole systems, and find that the qualitative nature of the timing and spectral behavior of NGC 5408 X-1 is similar to systems in the steep power-law state exhibiting Type-C QPOs. However, in order for this analogy to quantitatively hold we must only be seeing the so-called saturated portion of the QPO frequency-photon index (or disk flux) relation. Assuming this to be the case, we place a lower limit on the mass of NGC 5408 X-1 of greater than or equal to 800 solar mass. Alternatively, the QPO frequency is largely independent of the spectral parameters, in which case a close analogy with the Type-C QPOs in stellar system is problematic. Measurement of the source's timing properties over a wider range of energy spectral index is needed to definitively resolve this ambiguity. We searched all the available data for both a broad Fe emission line as well as high-frequency QPO analogs (0.1- 1 Hz), but detected neither. We place upper limits on the equivalent width of any Fe emission feature in the 6-7 keV band and of the amplitude (rms) of a high-frequency QPO analog of approximately equal to 10 eV and approximately equal to 4%, respectively.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hannam, Mark; School of Physics and Astronomy, Cardiff University, Cardiff, CF24 3AA; Husa, Sascha
We present gravitational waveforms for the last orbits and merger of black-hole-binary systems along two branches of the black-hole-binary parameter space: equal-mass binaries with equal nonprecessing spins, and nonspinning unequal-mass binaries. The waveforms are calculated from numerical solutions of Einstein's equations for black-hole binaries that complete between six and ten orbits before merger. Along the equal-mass spinning branch, the spin parameter of each black hole is {chi}{sub i}=S{sub i}/M{sub i}{sup 2}(set-membership sign)[-0.85,0.85], and along the unequal-mass branch the mass ratio is q=M{sub 2}/M{sub 1}(set-membership sign)[1,4]. We discuss the construction of low-eccentricity puncture initial data for these cases, the properties ofmore » the final merged black hole, and compare the last 8-10 gravitational-wave cycles up to M{omega}=0.1 with the phase and amplitude predicted by standard post-Newtonian (PN) approximants. As in previous studies, we find that the phase from the 3.5PN TaylorT4 approximant is most accurate for nonspinning binaries. For equal-mass spinning binaries the 3.5PN TaylorT1 approximant (including spin terms up to only 2.5PN order) gives the most robust performance, but it is possible to treat TaylorT4 in such a way that it gives the best accuracy for spins {chi}{sub i}>-0.75. When high-order amplitude corrections are included, the PN amplitude of the (l=2, m={+-}2) modes is larger than the numerical relativity amplitude by between 2-4%.« less
NASA Astrophysics Data System (ADS)
Laissue, Jean A.; Blattmann, Hans; Di Michiel, Marco; Slatkin, Daniel N.; Lyubimova, Nadia; Guzman, Raphael; Zimmermann, Werner; Birrer, Stephan; Bley, Tim; Kircher, Patrick; Stettler, Regina; Fatzer, Rosmarie; Jaggy, Andre; Smilowitz, Henry; Brauer, Elke; Bravin, Alberto; Le Duc, Geraldine; Nemoz, Christian; Renier, Michel; Thomlinson, William C.; Stepanek, Jiri; Wagner, Hans-Peter
2001-12-01
The cerebellum of the weanling piglet (Yorkshire) was used as a surrogate for the radiosensitive human infant cerebellum in a Swiss-led program of experimental microbeam radiation therapy (MRT) at the ESRF. Five weanlings in a 47 day old litter of seven, and eight weanlings in a 40 day old litter of eleven were irradiated in November, 1999 and June, 2000, respectively. A 1.5 cm-wide x 1.5 xm-high array of equally space approximately equals 20-30 micrometers wide, upright microbeams spaced at 210 micrometers intervals was propagated horizontally, left to right, through the cerebella of the prone, anesthetized piglets. Skin-entrance intra-microbeam peak adsorbed doses were uniform, either 150, 300, 425, or 600 gray (Gy). Peak and inter-microbeam (valley) absorbed doses in the cerebellum were computed with the PSI version of the Monte Carlo code GEANT and benchmarked using Gafchromic and radiochromic film microdosimetry. For approximately equals 66 weeks [first litter; until euthanasia], or approximately equals 57 weeks [second litter; until July 30, 2001] after irradiation, the littermates were developmentally, behaviorally, neurologically and radiologically normal as observed and tested by experienced farmers and veterinary scientists unaware of which piglets were irradiated or sham-irradiated. Morever, MRT implemented at the ESRF with a similar array of microbeams and a uniform skin-entrance peak dose of 625 Gy, followed by immunoprophylaxis, was shown to be palliative or curative in young adult rats bearing intracerebral gliosarcomas. These observations give further credence to MRT's potential as an adjunct therapy for brain tumors in infancy, when seamless therapeutic irradiation of the brain is hazardous.
The Algol-like binary TT Hydrae - The stars, circumstellar matter, and superionized plasma
NASA Technical Reports Server (NTRS)
Plavec, Mirek J.
1988-01-01
This paper reports on superionized UV emission lines discovered in TT Hydrae (HD 97528), a semidetached eclipsing binary system in the Southern-Hemisphere sky. The list of emission lines observed is typical for interacting nondegenerate binaries of the Algol type, but with system-specific relative-intensity characteristics. The primary component of the system is a B9.5 V main-sequence star with effective temperature of 9800 K. Its mass equals 2.25 solar masses; the radius is 1.9 solar radii; and surface gravity log g equals 4.23. The secondary star has a mass of 0.41 solar mass and fills its critical Roche lobe. Evidence obtained on mass interaction supports the conclusion that HD 97528 is a normal semidetached system.
Shashidhar, C; Shivanna, Vasundhara; Shivamurthy, Gb; Shashidhar, Jyothi
2011-01-01
The objective of this study was to compare bacterial leakage using streptococcus mutans through gutta-percha and a thermoplastic synthetic polymer based root canal filling material (Resilon) using two filling techniques. A total of 90 single-rooted extracted human teeth were subjected for the study. Teeth were divided into 6 groups of 10 and 3 control groups of 10 teeth each. All the samples were decoronated and the coronal surfaces of the roots were prepared perpendicular to the long axis of the root with a high-speed handpiece and a multipurpose bur using air water spray. The length of all the roots was prepared approximately 16 mm from the coronal surface to the apex of the root. Roots were filled using lateral and vertical condensation techniques with gutta-percha and AH26 sealer (Group 1 and 2) or with gutta-percha and epiphany sealer (Group 3 and 4). Group 5 and 6 were filled with Resilon and epiphany sealer using the lateral and vertical condensation techniques. A split chamber microbial leakage model was used in which S. mutans placed in the upper chamber could reach the lower chamber only through the filled root canal. Group 7 and 8 (positive control) were filled with Resilon and gutta-percha without sealer and tested with bacteria, whereas Group 7 (negative control) was sealed with wax to test the seal between the chambers. Data were analyzed using Kruskal-Wallis test and Mann-Whitney U test. All positive groups (Group 7 and 8) showed leakage within 1 hour of the start of the study (100%), whereas none of the negative control (Group 9) leaked. The roots obturated with Resilon and epiphany (Group 5 and 6) showed minimal leakage, i.e., each with 6 leakages, which was significantly less than gutta-percha (Group 1-4), in which approximately 80% of specimens with either sealer or techniques leaked. Kruskal-Wallis test showed statistical significance when all groups were compared (P<0.05). Mann-Whitney U test compared the respective groups and found Resilon groups superior to gutta-percha groups (P<0.05). This study demonstrated that the new polymer-based Resilon and epiphany sealer using two obturating techniques, i.e., lateral as well as vertical condensation found to be significantly better than the gutta-percha.
On the Alignment of Strain, Vorticity and Scalar Gradient in Turbulent, Buoyant, Nonpremixed Flames
NASA Technical Reports Server (NTRS)
Boratav, O. N.; Elghobashi, S. E.; Zhong, R.
1999-01-01
The alignment of vorticity and scalar gradient with the eigendirections of the rate of strain tensor is investigated in turbulent buoyant nonpremixed horizontal and vertical flames. The uniqueness of a buoyant nonpremixed flame is that it contains regions with distinct alignment characteristics. The strain-enstrophy angle Psi is used to identify these regions. Examination of the vorticity field and the vorticity production in these different regions indicates that Psi and consequently the alignment properties near the flame surface identified by the mixture fraction band F approximately equals F(sub st) differ from those in the fuel region, F > F(sub st) and the oxidizer region, F < F(sub st). The F approximately equals F(sub st) band shows strain-dominance resulting in vorticity/alpha alignment while F > F(sub st) (and F < F(sub st) for the vertical flame) band(s) show(s) vorticity/beta alignment. The implication of this result is that the scalar dissipation, epsilon(sub F), attains its maximum value always near F approximately equals F(sub st). These results are also discussed within the framework of recent dynamical results [Galanti et al., Nonlinearity 10, 1675 (1997)] suggesting that the Navier-Stokes equations evolved towards an attracting solution. It is shown that the properties of such an attracting solution are also consistent with our results of buoyant turbulent nonpremixed flames.
Approximate controllability of a system of parabolic equations with delay
NASA Astrophysics Data System (ADS)
Carrasco, Alexander; Leiva, Hugo
2008-09-01
In this paper we give necessary and sufficient conditions for the approximate controllability of the following system of parabolic equations with delay: where [Omega] is a bounded domain in , D is an n×n nondiagonal matrix whose eigenvalues are semi-simple with nonnegative real part, the control and B[set membership, variant]L(U,Z) with , . The standard notation zt(x) defines a function from [-[tau],0] to (with x fixed) by zt(x)(s)=z(t+s,x), -[tau][less-than-or-equals, slant]s[less-than-or-equals, slant]0. Here [tau][greater-or-equal, slanted]0 is the maximum delay, which is supposed to be finite. We assume that the operator is linear and bounded, and [phi]0[set membership, variant]Z, [phi][set membership, variant]L2([-[tau],0];Z). To this end: First, we reformulate this system into a standard first-order delay equation. Secondly, the semigroup associated with the first-order delay equation on an appropriate product space is expressed as a series of strongly continuous semigroups and orthogonal projections related with the eigenvalues of the Laplacian operator (); this representation allows us to reduce the controllability of this partial differential equation with delay to a family of ordinary delay equations. Finally, we use the well-known result on the rank condition for the approximate controllability of delay system to derive our main result.
MOLECULAR BONDING SYSTEM - INNOVATIVE TECHNOLOGY EVALUATION REPORT
This document presents an evaluation of the Molecular Bonding System (MBS) and its ability to chemically stabilize three metals-contaminated wstes/soils during a SITe demo. The MBS process treated approximately 500 tons each of soil/Fill, Slag, and Miscellaneous Smelter Waste wit...
Chiral interface at the finite temperature transition point of QCD
NASA Technical Reports Server (NTRS)
Frei, Z.; Patkos, A.
1990-01-01
The domain wall between coexisting chirally symmetric and broken symmetry regions is studied in a saddle point approximation to the effective three-flavor sigma model. In the chiral limit the surface tension varies in the range ((40 to -50)MeV)(exp 3). The width of the domain wall is estimated to be approximately or equal to 4.5 fm.
Annealing temperature and O2 partial pressure dependence of T(sub c) in HgBa2CuO(4+delta)
NASA Technical Reports Server (NTRS)
Xiong, Q.; Cao, Y.; Chen, F.; Xue, Y. Y.; Chu, C. W.
1994-01-01
Samples of HgBa2CuO(4+delta) (Hg-1201) were annealed under various conditions. After carefully controlling annealing time, annealing temperature (T(sub a)) and O2 partial pressure (P(sub 0)), we were able to find the reversible annealing conditions for Hg-1201. Under 1 atm O2 at 260 C less than or equal to T(sub a) less than or equal to 400 C, the obtained T(sub c) is nearly the same (approximately 97 K). However, it decreases quickly with T(sub a) greater than 300 C in high vacuum (P(sub 0) approximately 10(exp -8) atm), and reaches zero at T(sub a) = 400 C. On the other hand, T(sub c) decreases with the decrease of T(sub a) in high-pressure O2 (approximately 500 atm) and reaches approximately 20 K at about 240 C. In the entire annealing region, the oxygen surplus varies significantly from 0.03 to 0.4, and a wide range of T(sub c) variation (0 goes to 97 K goes to 20 K) was obtained with anion doping alone.
is shown that the maximum ac efficiency is equal to approximately 70% of the corresponding dc value. An illustrative example, including a proposed design for a rather unconventional transformer, is appended. (Author)
Assessing dental caries prevalence in African-American youth and adults.
Seibert, Wilda; Farmer-Dixon, Cherae; Bolden, Theodore E; Stewart, James H
2004-01-01
It has been well documented that dental caries affect millions of children in the USA with the majority experiencing decay by the late teens. This is especially true for low-income minorities. The objective of this descriptive study was to determine dental caries prevalence in a sample of low-income African-American youth and adults. A total of 1034 individuals were examined. They were divided into two age groups: youth, 9-19 years and adults, 20-39 years. Females comprised approximately 65 percent (64.5) of the study group. The DMFT Index was used to determine caries prevalence in this study population. The DMFT findings showed that approximately 73 percent (72.9 percent) of the youth had either decayed, missing or filled teeth. Male youth had slightly higher DMFT mean scores than female youth: male mean = 7.93, standard error = 0.77, female mean = 7.52, standard error = 0.36; however, as females reached adulthood their DMFT scores increased substantially, mean = 15.18, standard error = 0.36. Caries prevalence was much lower in male adults, DMFT, mean = 7.22, standard error of 0.33. The decayed component for female adults mean score was 6.81, a slight increase over adult males, mean = 6.58. Although there were few filled teeth in both age groups, female adults had slightly more filled teeth than male adults, females mean = 2.91 vs. males; however, adult males experienced slightly more missing teeth, mean = 5.62 as compared to adult females, mean = 5.46. n = 2.20. Both female and male adults had an increase in missing teeth. As age increased there was a significant correlation among decayed, missing and filled teeth as tested by Analysis of Variance (ANOVA), p < 0.01. A significant correlation was found between filled teeth by sex, p < .005. We conclude that caries prevalence was higher in female and male youth, but dental caries increased more rapidly in females as they reached adulthood.
Numerical Simulation of Convective Heat and Mass Transfer in a Two-Layer System
NASA Astrophysics Data System (ADS)
Myznikova, B. I.; Kazaryan, V. A.; Tarunin, E. L.; Wertgeim, I. I.
The results are presented of mathematical and computer modeling of natural convection in the “liquid-gas” two-layer system, filling a vertical cylinder surrounded by solid heat conductive tract. The model describes approximately the conjugate heat and mass transfer in the underground oil product storage, filled partially by a hydrocarbon liquid, with natural gas layer above the liquid surface. The geothermal gradient in a rock mass gives rise to the intensive convection in the liquid-gas system. The consideration is worked out for laminar flows, laminar-turbulent transitional regimes, and developed turbulent flows.
NASA Astrophysics Data System (ADS)
Panda, Rudrashish; Sahu, Sivabrata; Rout, G. C.
2017-05-01
We communicate here a tight binding theoretical model study of the band filling effect on the charge gap in graphene-on-substrate. The Hamiltonian consists of nearest neighbor electron hopping and substrate induced gap. Besides this the Coulomb interaction is considered here within mean-field approximation in the paramagnetic limit. The electron occupancies at two sublattices are calculated by Green's function technique and are solved self consistently. Finally the charge gap i.e. Δ ¯=U [ < na > -< nb > ] is calculated and computed numerically. The results are reported.
2008-04-10
CAPE CANAVERAL, Fla. -- A beach on NASA's Kennedy Space Center is the site designated for cleanup of debris. More than 130 volunteers from the joint NASA’s Kennedy Space Center and U.S. Fish and Wildlife Service contract organizations give up their afternoon to gather all the “unnatural” items that had accumulated on 6.1 miles of central Florida east coast shoreline during the past 12 months. Part of the center's dedication to a clean environment, volunteers gathered enough trash to fill approximately 450 garbage bags and enough recyclable plastic and glass to fill 150 bags. Photo credit: NASA/Dimitri Gerondidakis
Mass predictions from the Garvey-Kelson mass relations
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jaenecke, J.; Masson, P.J.
Part A: The transverse Garvey-Kelson mass relation represents a homogeneous third-order partial difference equation. Procedures are described for estimating masses of nuclei with Ngreater than or equal toZ from the most general solution of this difference equation subject to a chi/sup 2/ minimization, using the recent atomic mass adjustment of Wapstra, Audi, and Hoekstra as a boundary condition. A judicious division of the input data in subsets of neutron-rich and proton-rich nuclei had to be introduced to reduce systematic errors in long-range extrapolations. Approximately 5600 mass-excess values for nuclei with 2less than or equal toZless than or equal to103, 4lessmore » than or equal toNless than or equal to157, and Ngreater than or equal toZ (except N = Z odd for A<40) have been calculated. The standard deviation for reproducing the known mass-excess values is sigma/sub m/approx. =103 keV.« less
Using agency nurses to fill RN vacancies within specialized hospice and palliative care
Cozad, Melanie J.; Lindley, Lisa C.; Mixer, Sandy J.
2016-01-01
The use of agency nurses offers flexibility in filling registered nurse openings during times of shortage, yet little is known about their use in specialized palliative care. In an effort to fill this knowledge gap, this study determined whether significant relationships existed between full-time and part-time RN vacancies and the use of agency RNs within specialized hospices that deliver perinatal end of life care to women and their families in the event of miscarriage, ectopic pregnancy, or other neonatal complications resulting in death. This study used data from the 2007 National Home and Hospice Care Survey and multivariate regression methods to estimate the association between RN vacancies and agency RNs use. Approximately 13% of perinatal hospices in 2007 used agency nurses. Increases in full-time RN vacancies are associated with a significant increase in the use of agency RNs, while part-time RN vacancies are associated with a significant decrease in agency RNs. These results suggest that full-time agency RNs were used as a supplemental workforce to fill vacancies until the full-time position is recruited. However, for part-time vacancies, the responsibilities of those positions shifted onto existing staff and the position was not filled. PMID:27683508
General relativistic corrections to the weak lensing convergence power spectrum
NASA Astrophysics Data System (ADS)
Giblin, John T.; Mertens, James B.; Starkman, Glenn D.; Zentner, Andrew R.
2017-11-01
We compute the weak lensing convergence power spectrum, Cℓκκ, in a dust-filled universe using fully nonlinear general relativistic simulations. The spectrum is then compared to more standard, approximate calculations by computing the Bardeen (Newtonian) potentials in linearized gravity and partially utilizing the Born approximation. We find corrections to the angular power spectrum amplitude of order ten percent at very large angular scales, ℓ˜2 - 3 , and percent-level corrections at intermediate angular scales of ℓ˜20 - 30 .
Finite-temperature Gutzwiller approximation from the time-dependent variational principle
NASA Astrophysics Data System (ADS)
Lanatà, Nicola; Deng, Xiaoyu; Kotliar, Gabriel
2015-08-01
We develop an extension of the Gutzwiller approximation to finite temperatures based on the Dirac-Frenkel variational principle. Our method does not rely on any entropy inequality, and is substantially more accurate than the approaches proposed in previous works. We apply our theory to the single-band Hubbard model at different fillings, and show that our results compare quantitatively well with dynamical mean field theory in the metallic phase. We discuss potential applications of our technique within the framework of first-principle calculations.
Peutzfeldt, A; Mühlebach, S; Lussi, A; Flury, S
The aim of this in vitro study was to investigate the marginal gap formation of a packable "regular" resin composite (Filtek Supreme XTE [3M ESPE]) and two flowable "bulk fill" resin composites (Filtek Bulk Fill [3M ESPE] and SDR [DENTSPLY DeTrey]) along the approximal margins of Class II restorations. In each of 39 extracted human molars (n=13 per resin composite), mesial and distal Class II cavities were prepared, placing the gingival margins below the cemento-enamel junction. The cavities were restored with the adhesive system OptiBond FL (Kerr) and one of the three resin composites. After restoration, each molar was cut in half in the oro-vestibular direction between the two restorations, resulting in two specimens per molar. Polyvinylsiloxane impressions were taken and "baseline" replicas were produced. The specimens were then divided into two groups: At the beginning of each month over the course of six months' tap water storage (37°C), one specimen per molar was subjected to mechanical toothbrushing, whereas the other was subjected to thermocycling. After artificial ageing, "final" replicas were produced. Baseline and final replicas were examined under the scanning electron microscope (SEM), and the SEM micrographs were used to determine the percentage of marginal gap formation in enamel or dentin. Paramarginal gaps were registered. The percentages of marginal gap formation were statistically analyzed with a nonparametric analysis of variance followed by Wilcoxon-Mann-Whitney tests and Wilcoxon signed rank tests, and all p-values were corrected with the Bonferroni-Holm adjustment for multiple testing (significance level: α=0.05). Paramarginal gaps were analyzed descriptively. In enamel, significantly lower marginal gap formation was found for Filtek Supreme XTE compared to Filtek Bulk Fill ( p=0.0052) and SDR ( p=0.0289), with no significant difference between Filtek Bulk Fill and SDR ( p=0.4072). In dentin, significantly lower marginal gap formation was found for SDR compared to Filtek Supreme XTE ( p<0.0001) and Filtek Bulk Fill ( p=0.0015), with no significant difference between Filtek Supreme XTE and Filtek Bulk Fill ( p=0.4919). Marginal gap formation in dentin was significantly lower than in enamel ( p<0.0001). The percentage of restorations with paramarginal gaps varied between 0% and 85%, and for all three resin composites the percentages were markedly higher after artificial ageing. The results from this study suggest that in terms of marginal gap formation in enamel, packable resin composites may be superior to flowable "bulk fill" resin composites, while in dentin some flowable "bulk fill" resin composites may be superior to packable ones.
Scaling differences between large interplate and intraplate earthquakes
NASA Technical Reports Server (NTRS)
Scholz, C. H.; Aviles, C. A.; Wesnousky, S. G.
1985-01-01
A study of large intraplate earthquakes with well determined source parameters shows that these earthquakes obey a scaling law similar to large interplate earthquakes, in which M sub o varies as L sup 2 or u = alpha L where L is rupture length and u is slip. In contrast to interplate earthquakes, for which alpha approximately equals 1 x .00001, for the intraplate events alpha approximately equals 6 x .0001, which implies that these earthquakes have stress-drops about 6 times higher than interplate events. This result is independent of focal mechanism type. This implies that intraplate faults have a higher frictional strength than plate boundaries, and hence, that faults are velocity or slip weakening in their behavior. This factor may be important in producing the concentrated deformation that creates and maintains plate boundaries.
Eyewitness accuracy rates in police showup and lineup presentations: a meta-analytic comparison.
Steblay, Nancy; Dysart, Jennifer; Fulero, Solomon; Lindsay, R C
2003-10-01
Meta-analysis is used to compare identification accuracy rates in showups and lineups. Eight papers were located, providing 12 tests of the hypothesis and including 3013 participants. Results indicate that showups generate lower choosing rates than lineups. In target present conditions, showups and lineups yield approximately equal hit rates, and in target absent conditions, showups produce a significantly higher level of correct rejections. False identification rates are approximately equal in showups and lineups when lineup foil choices are excluded from analysis. Dangerous false identifications are more numerous for showups when an innocent suspect resembles the perpetrator. Function of lineup foils, assessment strategies for false identifications, and the potential impact of biases in lineup practice are suggested as additional considerations in evaluation of showup versus lineup efficacy.
Low Noise in a Diffusion-Cooled Hot-Electron Mixer at 2.5 THz
NASA Technical Reports Server (NTRS)
Karasik, B. S.; Gaidis, M. C.; McGrath, W. R.; Bumble, B.; LeDuc, H. G.
1997-01-01
The noise performance of a Nb hot-electron bolometer mixer at 2.5 THz has been investigated. The devices are fabricated from a 12-nm-thick Nb film, and have a 0.30 micrometer x 0.15 micrometer in-plane size, thus exploiting diffusion as the electron cooling mechanism. The rf coupling was provided by a twin-slot planar antenna on an elliptical Si lens. The experimentally measured double sideband noise temperature of the receiver was as low as 2750 +/- 250 K with an estimated mixer noise temperature of approximately equal 900 K. The mixer bandwidth derived from both noise bandwidth and IF impedance measurements was approximately equal 1.4 GHz. These results demonstrate the low-noise operation of the diffusion-cooled bolometer mixer above 2 THz.
Method and apparatus for ion sequestration and a nanostructured metal phosphate
Mattigod, Shas V [Richland, WA; Fryxell, Glen E [Kennewic, WA; Li, Xiaohong [Richland, WA; Parker, Kent E [Kennewick, WA; Wellman, Dawn M [West Richland, WA
2010-04-06
A nanostructured substance, a process for sequestration of ionic waste, and an ion-sequestration apparatus are disclosed in the specification. The nanostructured substance can comprise a Lewis acid transition metal bound to a phosphate, wherein the phosphate comprises a primary structural component of the substance and the Lewis acid transition metal is a reducing agent. The nanostructured substance has a Brunner-Emmet-Teller (BET) surface area greater than or equal to approximately 100 m.sup.2/g, and a distribution coefficient for an analyte, K.sub.d, greater than or equal to approximately 5000 ml/g. The process can comprise contacting a fluid and a nanostructured metal phosphate. The apparatus can comprise a vessel and a nanostructured metal phosphate. The vessel defines a volume wherein a fluid contacts the nanostructured metal phosphate.
NASA Astrophysics Data System (ADS)
Kel'manov, A. V.; Motkova, A. V.
2018-01-01
A strongly NP-hard problem of partitioning a finite set of points of Euclidean space into two clusters is considered. The solution criterion is the minimum of the sum (over both clusters) of weighted sums of squared distances from the elements of each cluster to its geometric center. The weights of the sums are equal to the cardinalities of the desired clusters. The center of one cluster is given as input, while the center of the other is unknown and is determined as the point of space equal to the mean of the cluster elements. A version of the problem is analyzed in which the cardinalities of the clusters are given as input. A polynomial-time 2-approximation algorithm for solving the problem is constructed.
Hamiltonian theory of gaps, masses, and polarization in quantum Hall states
NASA Astrophysics Data System (ADS)
Shankar, R.
2001-02-01
In two short papers I had described an extension, to all length scales, of the Hamiltonian theory of composite fermions (CF) that Murthy and I developed for the infrared, and applied it to compute finite-temperature quantities for quantum Hall fractions. I furnish details of the extended theory and apply it to Jain fractions ν=p/(2ps+1). The explicit operator description in terms of the CF allows one to answer quantitative and qualitative issues, some of which cannot even be posed otherwise. I compute activation gaps for several potentials, exhibit their particle-hole symmetry, the profiles of charge density in states with a quasiparticle or hole (all in closed form), and compare to results from trial wave functions and exact diagonalization. The Hartree-Fock approximation is used, since much of the nonperturbative physics is built-in at tree level. I compare the gaps to experiment, and comment on the rough equality of normalized masses near half- and quarter-filling. I compute the critical fields at which the Hall system will jump from one quantized value of polarization to another, and the polarization and relaxation rates for half-filling as a function of temperature and propose a Korringa-like law. After providing some plausibility arguments, I explore the possibility of describing several magnetic phenomena in dirty systems with an effective potential, by extracting a free parameter describing the potential from one data point and then using it to predict all the others from that sample. This works to the accuracy typical of this theory (10-20 %). I explain why the CF behaves like a free particle in some magnetic experiments when it is not, what exactly the CF is made of, what one means by its dipole moment, and how the comparison of theory to experiment must be modified to fit the peculiarities of the quantized Hall problem.
Cell dialysis by sharp electrodes can cause nonphysiological changes in neuron properties
Hooper, Scott L.; Guschlbauer, Christoph; Schmidt, Joachim; Büschges, Ansgar
2015-01-01
We recorded from lobster and leech neurons with two sharp electrodes filled with solutions often used with these preparations (lobster: 0.6 M K2SO4 or 2.5 M KAc; leech: 4 M KAc), with solutions approximately matching neuron cytoplasm ion concentrations, and with 6.5 M KAc (lobster, leech) and 0.6 M KAc (lobster). We measured membrane potential, input resistance, and transient and sustained depolarization-activated outward current amplitudes in leech and these neuron properties and hyperpolarization-activated current time constant in lobster, every 10 min for 60 min after electrode penetration. Neuron properties varied with electrode fill. For fills with molarities ≥2.5 M, neuron properties also varied strongly with time after electrode penetration. Depending on the property being examined, these variations could be large. In leech, cell size also increased with noncytoplasmic fills. The changes in neuron properties could be due to the ions being injected from the electrodes during current injection. We tested this possibility in lobster with the 2.5 M KAc electrode fill by making measurements only 10 and 60 min after penetration. Neuron properties still changed, although the changes were less extreme. Making measurements every 2 min showed that the time-dependent variations in neuron properties occurred in concert with each other. Neuron property changes with high molarity electrode-fill solutions were great enough to decrease neuron firing strongly. An experiment with 14C-glucose electrode fill confirmed earlier work showing substantial leak from sharp electrodes. Sharp electrode work should thus be performed with cytoplasm-matched electrode fills. PMID:26063785
Cell dialysis by sharp electrodes can cause nonphysiological changes in neuron properties.
Hooper, Scott L; Thuma, Jeffrey B; Guschlbauer, Christoph; Schmidt, Joachim; Büschges, Ansgar
2015-08-01
We recorded from lobster and leech neurons with two sharp electrodes filled with solutions often used with these preparations (lobster: 0.6 M K2SO4 or 2.5 M KAc; leech: 4 M KAc), with solutions approximately matching neuron cytoplasm ion concentrations, and with 6.5 M KAc (lobster, leech) and 0.6 M KAc (lobster). We measured membrane potential, input resistance, and transient and sustained depolarization-activated outward current amplitudes in leech and these neuron properties and hyperpolarization-activated current time constant in lobster, every 10 min for 60 min after electrode penetration. Neuron properties varied with electrode fill. For fills with molarities ≥2.5 M, neuron properties also varied strongly with time after electrode penetration. Depending on the property being examined, these variations could be large. In leech, cell size also increased with noncytoplasmic fills. The changes in neuron properties could be due to the ions being injected from the electrodes during current injection. We tested this possibility in lobster with the 2.5 M KAc electrode fill by making measurements only 10 and 60 min after penetration. Neuron properties still changed, although the changes were less extreme. Making measurements every 2 min showed that the time-dependent variations in neuron properties occurred in concert with each other. Neuron property changes with high molarity electrode-fill solutions were great enough to decrease neuron firing strongly. An experiment with (14)C-glucose electrode fill confirmed earlier work showing substantial leak from sharp electrodes. Sharp electrode work should thus be performed with cytoplasm-matched electrode fills. Copyright © 2015 the American Physiological Society.
17. INTERIOR VIEW OF THE GENERATOR HOUSE, LOOKING NORTHEAST TOWARD ...
17. INTERIOR VIEW OF THE GENERATOR HOUSE, LOOKING NORTH-EAST TOWARD THE ENCLOSED ROOM HOUSING A BACK-FILLED SHAFT. - Tower Hill No. 2 Mine, Approximately 0.47 mile Southwest of intersection of Stone Church Road & Township Route 561, Hibbs, Fayette County, PA
16 CFR 1209.2 - Definitions and measurements.
Code of Federal Regulations, 2011 CFR
2011-01-01
...) As used in this part 1209, Cellulose insulation means cellulosic fiber, loose fill, thermal... with the technical requirements of this standard, the figures are given in the metric system of measurement. The inch-pound system approximations of these figures are provided in parentheses for convenience...
16 CFR 1209.2 - Definitions and measurements.
Code of Federal Regulations, 2010 CFR
2010-01-01
...) As used in this part 1209, Cellulose insulation means cellulosic fiber, loose fill, thermal... with the technical requirements of this standard, the figures are given in the metric system of measurement. The inch-pound system approximations of these figures are provided in parentheses for convenience...
Potential problems on I-77 concrete culvert.
DOT National Transportation Integrated Search
1976-01-01
Along a section of Interstate 77 in Carroll County, it was necessary to construct a fill approximately 256 ft deep. The flow of a mountain stream had to be carried through this massive embankment and, because of the nature of the terrain, it was deci...
NASA Astrophysics Data System (ADS)
Sorokin, Vladislav V.; Stepanov, Gennady V.; Shamonin, Mikhail; Monkman, Gareth J.; Kramarenko, Elena Yu
2017-03-01
Magnetoactive elastomers (MAE) based on soft silicone matrices, filled with various proportions of large diameter (approximately 50 μm) iron and small diameter (approximately 0.5 μm) magnetite particles are synthesized. Their rheological behavior in homogeneous magnetic fields up to 600 mT is studied in detail. The addition of small magnetite particles facilitates fabrication of uniformly distributed magnetic elastomer composites by preventing aggregation and sedimentation of large particles during curing. It is shown that using the proposed bimodal filler particles it is possible to tailor various magnetorheological (MR) properties which can be useful for different target applications. In particular, either absolute or relative magnetorheological effects can be tuned. The value of the damping factor as well as the range of deformation amplitudes for the linear viscoelastic regime can be chosen. The interdependencies between different MR properties of bimodal MAEs are considered. The results are discussed in the model framework of particle network formation under the simultaneous influence of external magnetic fields and mechanical deformation.
Redbank and Fancher Creeks, California: General Design Memorandum
1986-02-01
agricultural areas not adjacent to mainstream channels. The runoff for these areas, which are downstream of the Enterprise Canal, was assumed to be zero ...for Dry Creek near Lemon Cove. The skews were negative for all the shorter durations and approached a skew of zero for the Dry Creek at Academy and...potentially non-conservative. However, since the cohesion intercept for the design "R" strength was set equal to zero , the impervious fill design strength
Investigation of the spreading of diesel injection jets using a new high-speed 3D drum camera
NASA Astrophysics Data System (ADS)
Eisfeld, Fritz
1997-05-01
To improve the combustion of the diesel engine it is important that the combustion chamber is equally filled with fuel and vapor of fuel. The investigation of the spatial spreading of the injection jet is possible with optical methods. Therefore a drum camera for 3D was developed to take this spatial event. The camera and the first results of the investigations of different injection nozzles are described.
NASA Astrophysics Data System (ADS)
Jansen, E. Duco; Asshauer, Thomas; Frenz, Martin; Delacretaz, Guy P.; Motamedi, Massoud; Welch, Ashley J.
1995-05-01
Mechanical injury during pulsed laser ablation of tissue is caused by rapid bubble expansions and collapse or by laser-induced pressure waves. In this study the effect of material elasticity on the ablation process has been investigated. Polyacrylamide tissue phantoms with various water concentrations (75-95%) were made. The Young's moduli of the gels were determined by measuring the stress-strain relationship. An optical fiber (200 or 400 micrometers ) was translated into the clear gel and one pulse of holmium:YAG laser radiation was given. The laser was operated in either the Q-switched mode (tau) p equals 500 ns, Qp equals 14 +/- 1 mJ, 200 micrometers fiber, Ho equals 446 mJ/mm2) or the free-running mode ((tau) p equals 100 microsecond(s) , Qp equals 200 +/- 5 mJ, 400 micrometers fiber, Ho equals 1592 mJ/mm2). Bubble formation inside the gels was recorded using a fast flash photography setup while simultaneously recording pressures with a PVDP needle hydrophone (40 ns risetime) positioned in the gel, approximately 2 mm away from the fibertip. A thermo-elastic expansion wave was measured only during Q-switched pulse delivery. The amplitude of this wave (approximately equals 40 bar at 1 mm from the fiber) did not vary significantly in any of the phantoms investigated. Rapid bubble formation and collapse was observed inside the clear gels. Upon bubble collapse, a pressure transient was emitted; the amplitude of this transient depended strongly on bubble size and geometry. It was found that (1) the bubble was almost spherical for the Q-switched pulse and became more elongated for the free-running pulse, and (2) the maximum bubble size and thus the collapse amplitude decreased with an increase in Young's modulus (from 68 +/- 11 bar at 1 mm in 95% water gel to 25 +/- 10 bar at 1 mm in 75% water gel).
NASA Technical Reports Server (NTRS)
Zhang, Y.-C.; Rossow, W. B.; Lacis, A. A.
1995-01-01
The largest uncertainty in upwelling shortwave (SW) fluxes (approximately equal 10-15 W/m(exp 2), regional daily mean) is caused by uncertainties in land surface albedo, whereas the largest uncertainty in downwelling SW at the surface (approximately equal 5-10 W/m(exp 2), regional daily mean) is related to cloud detection errors. The uncertainty of upwelling longwave (LW) fluxes (approximately 10-20 W/m(exp 2), regional daily mean) depends on the accuracy of the surface temperature for the surface LW fluxes and the atmospheric temperature for the top of atmosphere LW fluxes. The dominant source of uncertainty is downwelling LW fluxes at the surface (approximately equal 10-15 W/m(exp 2)) is uncertainty in atmospheric temperature and, secondarily, atmospheric humidity; clouds play little role except in the polar regions. The uncertainties of the individual flux components and the total net fluxes are largest over land (15-20 W/m(exp 2)) because of uncertainties in surface albedo (especially its spectral dependence) and surface temperature and emissivity (including its spectral dependence). Clouds are the most important modulator of the SW fluxes, but over land areas, uncertainties in net SW at the surface depend almost as much on uncertainties in surface albedo. Although atmospheric and surface temperature variations cause larger LW flux variations, the most notable feature of the net LW fluxes is the changing relative importance of clouds and water vapor with latitude. Uncertainty in individual flux values is dominated by sampling effects because of large natrual variations, but uncertainty in monthly mean fluxes is dominated by bias errors in the input quantities.
Composite superconducting wires obtained by high-rate tinning in molten Bi-Pb-Sr-Ca-Cu-O system
NASA Technical Reports Server (NTRS)
Grozav, A. D.; Konopko, L. A.; Leporda, N. I.
1990-01-01
The preparation of high-T(sub c) superconducting long composite wires by short-time tinning of the metal wires in a molten Bi-Pb-Sr-Ca-Cu-O compound is discussed. The application of this method to the high-T(sub c) materials is tested, possibly for the first time. The initial materials used for this experiment were ceramic samples with nominal composition Bi(1.5)Pb(0.5)Sr2Ca2Cu3O(x) and T(sub c) = 80 K prepared by the ordinary solid-state reaction, and industrial copper wires from 100 to 400 microns in diameter and from 0.5 to 1 m long. The continuously moving wires were let through a small molten zone (approximately 100 cubic mm). The Bi-based high-T(sub c) ceramics in a molten state is a viscous liquid and it has a strongly pronounced ability to spread on metal wire surfaces. The maximum draw rate of the Cu-wire, at which a dense covering is still possible, corresponds to the time of direct contact of wire surfaces and liquid ceramics for less than 0.1 s. A high-rate draw of the wire permits a decrease in the reaction of the oxide melt and Cu-wire. This method of manufacture led to the fabrication of wire with a copper core in a dense covering with uniform thickness of about h approximately equal to 5 to 50 microns. Composite wires with h approximately equal to 10 microns (h/d approximately equal to 0.1) sustained bending on a 15 mm radius frame without cracking during flexing.
NASA Technical Reports Server (NTRS)
Zdziarski, Andrzej A.; Johnson, W. Neil; Done, Chris; Smith, David; Mcnaron-Brown, Kellie
1995-01-01
We have obtained the first average 2-500 keV spectra of Seyfert galaxies, using the data from Ginga and Compton Gamma-Ray Observatory's (CGRO) Oriented Scintillation Spectrometer Experiment (OSSE). Our sample contains three classes of objects with markedly different spectra: radio-quiet Seyfert 1's and 2's, and radio-loud Seyfert 1's. The average radio-quiet Seyfert 1 spectrum is well-fitted by a power law continuum with the energy spectral index alpha approximately equals 0.9, a Compton reflection component corresponding to a approximately 2 pi covering solid angle, and ionized absorption. There is a high-energy cutoff in the incident power law continuum: the e-folding energy is E(sub c) approximately equals 0.6(sup +0.8 sub -0.3) MeV. The simplest model that describes this spectrum is Comptonization in a relativistic optically-thin thermal corona above the surface of an accretion disk. Radio-quiet Seyfert 2's show strong netural absorption, and there is an indication that their X-ray power laws are intrinsically harder. Finally, the radio-loud Seyfert spectrum has alpha approximately equals 0.7, moderate neutral absorption E(sub C) = 0.4(sup +0.7 sub -0.2) MeV, and no or little Compton reflection. This is incompatible with the radio-quiet Seyfert 1 spectrum, and probably indicating that the X-rays are beamed away from the accretion disk in these objects. The average spectra of Seyferts integrated over redshift with a power-law evolution can explain the hard X-ray spectrum of the cosmic background.
Cone structure and focusing of VLF and LF electromagnetic waves at high altitudes in the ionosphere
NASA Technical Reports Server (NTRS)
Alpert, Ya. L.; Green, J. L.
1994-01-01
The frequency and angle dependencies of the electric field radiated by an electric dipole E = E(sub 0) cos omega(t) are studied through numerical calculations of absolute value of E in the VLF and LF frequency bands where F is less than or equal 0.02 to 0.05 f(sub b) in a model ionosphere over an altitude region of 800-6000 km where the wave frequency and electron gyrofrequency varies between F approximately 4-500 kHz and f(sub b) is approximately equal (1.1 to 0.2) MHz respectively. It is found that the amplitudes of the electric field have large maxima in four regions: close to the direction of the Earth magnetic field line B(sub 0) (it is called the axis field E(sub 0), in the Storey E(sub St), reversed Storey E(sub RevSt), and resonance E(sub Res) cones. The maximal values of E(sub 0), E(sub Res), and E(sub RevSt) are the most pronounced close to the lower hybrid frequency, F approximately F(sub L). The flux of the electric field is concentrated in very narrow regions, with the apex angles of the cones Delta-B is approximately (0.1-1) deg. The enhancement and focusing of the electric field increases with altitude starting at Z greater than 800 km. At Z greater than or equal to 1000 up to 6000 km, the relative value of absolute value of E, in comparison with its value at Z = 800 km is about (10(exp 2) to 10(exp 4)) times larger. Thus the flux of VLF and LF electromagnetic waves generated at high altitudes in the Earth's ionosphere are trapped into very narrow conical beams similar to laser beams.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kirschner, J.; Kerherve, G.; Winkler, C.
In this article, a novel time-of-flight spectrometer for two-electron-emission (e,2e/{gamma},2e) correlation spectroscopy from surfaces at low electron energies is presented. The spectrometer consists of electron optics that collect emitted electrons over a solid angle of approximately 1 sr and focus them onto a multichannel plate using a reflection technique. The flight time of an electron with kinetic energy of E{sub kin}{approx_equal}25 eV is around 100 ns. The corresponding time- and energy resolution are typically {approx_equal}1 ns and {approx_equal}0.65 eV, respectively. The first (e,2e) data obtained with the present setup from a LiF film are presented.
Nustar and Chandra Insight into the Nature of the 3-40 Kev Nuclear Emission in Ngc 253
NASA Technical Reports Server (NTRS)
Lehmer, Bret D.; Wik, Daniel R.; Hornschemeier, Ann E.; Ptak, Andrew; Antoniu, V.; Argo, M.K.; Bechtol, K.; Boggs, S.; Christensen, F.E.; Craig, W.W.;
2013-01-01
We present results from three nearly simultaneous Nuclear Spectroscopic Telescope Array (NuSTAR) and Chandra monitoring observations between 2012 September 2 and 2012 November 16 of the local star-forming galaxy NGC 253. The 3-40 kiloelectron volt intensity of the inner approximately 20 arcsec (approximately 400 parsec) nuclear region, as measured by NuSTAR, varied by a factor of approximately 2 across the three monitoring observations. The Chandra data reveal that the nuclear region contains three bright X-ray sources, including a luminous (L (sub 2-10 kiloelectron volt) approximately few × 10 (exp 39) erg per s) point source located approximately 1 arcsec from the dynamical center of the galaxy (within the sigma 3 positional uncertainty of the dynamical center); this source drives the overall variability of the nuclear region at energies greater than or approximately equal to 3 kiloelectron volts. We make use of the variability to measure the spectra of this single hard X-ray source when it was in bright states. The spectra are well described by an absorbed (power-law model spectral fit value, N(sub H), approximately equal to 1.6 x 10 (exp 23) per square centimeter) broken power-law model with spectral slopes and break energies that are typical of ultraluminous X-ray sources (ULXs), but not active galactic nuclei (AGNs). A previous Chandra observation in 2003 showed a hard X-ray point source of similar luminosity to the 2012 source that was also near the dynamical center (Phi is approximately equal to 0.4 arcsec); however, this source was offset from the 2012 source position by approximately 1 arcsec. We show that the probability of the 2003 and 2012 hard X-ray sources being unrelated is much greater than 99.99% based on the Chandra spatial localizations. Interestingly, the Chandra spectrum of the 2003 source (3-8 kiloelectron volts) is shallower in slope than that of the 2012 hard X-ray source. Its proximity to the dynamical center and harder Chandra spectrum indicate that the 2003 source is a better AGN candidate than any of the sources detected in our 2012 campaign; however, we were unable to rule out a ULX nature for this source. Future NuSTAR and Chandra monitoring would be well equipped to break the degeneracy between the AGN and ULX nature of the 2003 source, if again caught in a high state.
A Simple Analytical Model for Asynchronous Dense WDM/OOK Systems
1994-06-01
asynchronous dense WDM systems employing an external OOK modulator. Our model is based upon a close approximation of the optical Fabry - Perot filter in the...receiver as a single-pole RC filter for signals that are bandlimitr i, & -equency band approximately equal to one sixtieth of the Fabry - Perot filter’s...4 A. INPUT SIGNAL ............................................................................................... 4 B. FABRY - PEROT FILTERED OUTPUT
Elevated temperature creep properties of NiAl cryomilled with and without Y2O3
NASA Technical Reports Server (NTRS)
Whittenberger, J. Daniel; Luton, Michael J.
1995-01-01
The creep properties of lots of NiAl cryomilled with and without Y2O3 have been determined in compression and tension. Although identical cryomilling procedures were used, differences in composition were found between the lot ground with 0.5 vol% yttria and the lot ground without Y2O3. Compression testing between 1000 and 1300 K yielded similar creep strengths for both materials, while tensile creep rupture testing indicated that the yttria-containing alloy was slightly stronger than the Y2O3-free version. Both compression and tensile testing showed two deformation regimes; whereas the stress state did not affect the high stress exponent (n approximately equals 10) mechanism, the low stress exponent regime n was approximately 6 in tension and approximately 2 in compression. The strengths in tension were somewhat less than those measured in compression, but the estimated activation energies (Q) of approximately 600 kJ/mol for tensile testing were closer to the previously measured values (approximately 700 kJ/mol) for NiAl-AlN and very different from the Q's of 400 and 200 kJ/mol for compression tests in the high and low stress exponent regimes, respectively. A Larson-Miller comparison indicated that cryomilling can produce an alloy with long-term, high-temperature strength at least equal to conventional superalloys.
Interstellar detection of the intersystem line Si II lambda 2335 toward zeta Ophiuchi
NASA Technical Reports Server (NTRS)
Cardelli, Jason A.; Sofia, Ulysses J.; Savage, Blair D.; Keenan, Francis P.; Dufton, Philip L.
1994-01-01
We report on the detection of the weak intersystem transistion of Si II lambda 2335 A in the sight line toward zeta Oph using the Ech-B mode (3.5 km/s resolution) of the Goddard High Resolution Spectrograph. The high-quality spectrum is characterized by an empirically measured signal-to-noise of 450, in excellent agreement with that expected from photon-statistics. The measured equivalent width of the Si II line is W(sub lambda) = 0.48 +/- 0.12 mA. Using the new experimental f-value of Calamai, Smith, and Bergeson, we find a Si II column density of 2.34 (+/- 0.58) x 10(exp 15) atoms/sq cm and (Si/H)(sub zeta Oph) = 1.78 (+/- 0.44) x 10(exp -6) for the principal absorbing component(s) at v(sub sun) approx. = -15 km/s. Analysis of the Si II lambda 1808 absorption over the same velocity range using the new experimental f-value of Bergeson & Lawler yields a column density (corrected for saturation) that is consistent within the weak line errors and confirms the relative accuracies of these new f-values. Furthermore, these results indicate that accurate abundances can now be derived for Si II, particularly from the weak Si II lambda 2335 A since it is free of saturation effects. For the zeta Oph v(sub sun) approx. = -15 km/s component(s), we find that greater than 95% of the available cosmic abundance (i.e. the 1989 meteoritic abundances of Anders & Grevesse) of Mg, Fe, and Si is 'missing' from the gas phase and is presumably locked up in the dust. These elements are present in the dust grains in ratios of Fe/Si approximately equals 0.9 and Mg/Si approximately equals 1.1, consistent with the ratio of their cosmic abundances. These ratios are in sharp contrast to more diffuse clouds like those seen toward the high-latitude halo star HD 93521 where in the dust Fe/Si approximately equals 1.8 and Mg/Si approximately equals 2.1.
Östberg, Anna-Lena; Kjellström, Anna N; Petzold, Max
2017-06-01
The objective was to examine associations between a primary Care Need Index (CNI) and dental caries experience. Dental journal records for 300 988 individuals in western Sweden, aged 3-19 years in 2007-09, were completed with official socioeconomic information. The CNI (independent variable), originally developed for assessing primary care need, was calculated for residential areas (small areas, parishes, dental clinics) based on markers of material deprivation, sociodemographic characteristics, social instability and cultural needs. Dental caries (dependent variable) was registered using the decayed, missing, filled teeth (DMFT) system. Multilevel Poisson regression and logistic regression models were used. All analyses were adjusted for age and gender. In the most deprived areas, the incidence rate ratio (IRR) for dental caries was up to five times higher than in the most affluent areas (reference); in small areas, the IRR for decayed teeth (DT) was 3.74 (95% CI: 3.39-4.12) and 5.11 (CI: 4.45-5.87) for decayed surfaces approximally (DSa). Caries indices including fillings (decayed filled teeth [DFT], decayed filled surfaces approximally [DFSa]) produced lower IRRs, with similar pictures at the parish and dental clinic level. The intracluster correlation was low overall, but stronger at lower geographical levels. The odds ratios for ≥3 caries lesions in the two most deprived areas of the CNI deciles were high, with a DT OR of 3.55 in small areas (95% CI: 3.39-3.73), compared with the eight more affluent deciles. There were strong associations between an index for assessing need in primary care, the CNI and dental caries in Swedish children and adolescents. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Nanoscale Capillary Flows in Alumina: Testing the Limits of Classical Theory.
Lei, Wenwen; McKenzie, David R
2016-07-21
Anodic aluminum oxide (AAO) membranes have well-formed cylindrical channels, as small as 10 nm in diameter, in a close packed hexagonal array. The channels in AAO membranes simulate very small leaks that may be present for example in an aluminum oxide device encapsulation. The 10 nm alumina channel is the smallest that has been studied to date for its moisture flow properties and provides a stringent test of classical capillary theory. We measure the rate at which moisture penetrates channels with diameters in the range of 10 to 120 nm with moist air present at 1 atm on one side and dry air at the same total pressure on the other. We extend classical theory for water leak rates at high humidities by allowing for variable meniscus curvature at the entrance and show that the extended theory explains why the flow increases greatly when capillary filling occurs and enables the contact angle to be determined. At low humidities our measurements for air-filled channels agree well with theory for the interdiffusive flow of water vapor in air. The flow rate of water-filled channels is one order of magnitude less than expected from classical capillary filling theory and is coincidentally equal to the helium flow rate, validating the use of helium leak testing for evaluating moisture flows in aluminum oxide leaks.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Stockstill, R.L.; George, J.F.
1996-09-01
Tests were conducted on two different 1:25-scale models of the New Bonneville Lock located on the Columbia River in Oregon. The lock models were built to study the filling and emptying systems, which consisted of designs utilizing bottom longitudinal floor culverts. The first design studied, defined as the H-H pattern system, consisted of four longitudinal flood culverts in each end of the lock chamber. The second system studied had two longitudinal floor culverts in each end of the lock chamber and was defined as the H pattern system. In the H-H pattern system, the filling culverts, which were located undermore » the lock chamber floor, connected to a crossover culvert with a horizontal splitter wall dividing the flow to upstream and downstream splitter manifolds were equal divisions led into four longitudinal flood culverts in each end of the lock chamber. With the type 6 (recommended) design and a 1-min valve opening time, the lock chamber filled in 8.7 min and emptied in 12.1 min. Due to differences in friction losses, the prototype can be expected to fill and empty about 20 percent faster than the model (7.0 min and 9.7 min, respectively). Modifications involving installing a slope in the lower sill and a v-notch design in the high sill were significant factors that resulted in fast filling and emptying times, low hawser forces, and only minor movement with various tow arrangements for different operating scenarios.« less
NASA Astrophysics Data System (ADS)
Kadioglu, Selma; Kagan Kadioglu, Yusuf
2016-04-01
Ordu-Giresun (OGU) is a newly-constructed airport, the first sea-filled airport in Turkey and in Europe, and the second airport in the world after Osaca-Japan. The airport is between Gulyalı district in Ordu city and Piraziz district in Giresun city in Black Sea -Turkey. A protection breakwater has been constructed by filling a rock approximately 7.435-m long and with an average height of 5.5 m. Then, the Black Sea has been filled until 1 m over the sea level, approximately the area is 1.770.000 m2 wide and includes a runway, aprons and taxiway covered by breakwater. The runway has a 1-m thickness, 3-km length and 45-m width, PCN84 strength, and stone mastic asphalt surface. The aprons has a 240 x 110 m length and PCN110 strength, the taxiway is 250 x 24 m wide. The airport was started to be constructed in July 2011 and it began to serve on 22th May 2015. The aim of this study was to determine the depth of the rock-filled layer and the amount of sinking of the bathymetry which has been determined before filling processing. In addition, before bathymetry determination, unconsolidated sediments had been removed from the bottom of the sea. There were four drilling points to control the sinking of the bathymetry. Therefore, six suitable Ground Penetrating Radar (GPR) profiles were measured, crossing these points with runway and aprons, using 250-MHz and 100-MHz shielded antennas. Starting points of the profiles were in the middle of the runway to merge between depth and thickness changing of the filled layer and bathymetry along the profiles. Surface topography changing was measured spaced 1 m apart with 1 cm sensitivity on each profile. At the same time, similarly the topography changing, bathymetry coordinates was re-arranged along the each profile. Topography corrections were applied to the processed radargrams and then the bottom boundary lines of the rock-filled layer were determined. The maximum height was 3.5 m according to the sea level, which was on the middle point of the runway, representing zero depth of the radargrams of the profiles. To determine the amount of the sinking of the rock filled layer, the first sea level were lined at 3.5 m in depth on the right side depth axes of the radargrams. The second, bathymetry changing lines were placed on the interested radargrams. Finally, differences between the bottom boundary lines of the filled layer and bathymetry lines were compared. The results showed that GPR method could be applied successfully to determine the depth of the rock filled layer in Black Sea and the small amount of the sinking of the bathymetry. Acknowledgement This project has been supported by Cengiz - Içtaş Joint Venture-Turkey. This study is a contribution to the EU funded COST action TU1208 "Civil Engineering Applications of Ground Penetrating Radar" (www.GPRadar.eu, www.cost.eu).
7. VIEW OF THE FAN HOUSE, LOOKING SOUTHWEST. A PARTIALLY ...
7. VIEW OF THE FAN HOUSE, LOOKING SOUTHWEST. A PARTIALLY FILLED AIR SHAFT IS SITUATED TO THE REAR (WEST) OF THE BUILDING. - Tower Hill No. 2 Mine, Approximately 0.47 mile Southwest of intersection of Stone Church Road & Township Route 561, Hibbs, Fayette County, PA
DOT National Transportation Integrated Search
2007-09-01
Resin Modified Pavement (RMP) is a composite paving material consisting of a thin layer (2 inches) : of open graded hot mix asphalt (HMA) whose internal air voids (approximately 30% voids) are : filled with a latex rubber-modified portland cement gro...
DOT National Transportation Integrated Search
2013-03-01
Coal power plants generate approximately 50% of the electricity in the : United States. As a result, large amounts of coal combustion byproducts, : especially fly ash, are produced annually. Only 40% of the fly ash : (mainly C and F-type classificati...
Thousands gather to watch a Space Shuttle Main Engine Test
2001-04-21
Approximately 13,000 people fill the grounds at NASA's John C. Stennis Space Center for the first-ever evening public engine test of a Space Shuttle Main Engine. The test marked Stennis Space Center's 20th anniversary celebration of the first Space Shuttle mission.
This document presents an evaluation of the Molecular Bonding System (MBS) and its ability to chemically stabilize three metals-contaminated wstes/soils during a SITe demo. The MBS process treated approximately 500 tons each of soil/Fill, Slag, and Miscellaneous Smelter Waste wit...
ECO-FRIENDLY GOLF TEES FILLED WITH CORN-BASED DDGS
The ethanol industry in the United States currently produces approximately 10,000,000 tons of corn processing co-products, namely distillers dried grains with solubles (DDGS). The primary use of DDGS to date has been in animal feed applications. However, there are limits to th...
Analytic approximations to the modon dispersion relation. [in oceanography
NASA Technical Reports Server (NTRS)
Boyd, J. P.
1981-01-01
Three explicit analytic approximations are given to the modon dispersion relation developed by Flierl et al. (1980) to describe Gulf Stream rings and related phenomena in the oceans and atmosphere. The solutions are in the form of k(q), and are developed in the form of a power series in q for small q, an inverse power series in 1/q for large q, and a two-point Pade approximant. The low order Pade approximant is shown to yield a solution for the dispersion relation with a maximum relative error for the lowest branch of the function equal to one in 700 in the q interval zero to infinity.
NASA Technical Reports Server (NTRS)
Frehlich, Rod
1993-01-01
Calculations of the exact Cramer-Rao Bound (CRB) for unbiased estimates of the mean frequency, signal power, and spectral width of Doppler radar/lidar signals (a Gaussian random process) are presented. Approximate CRB's are derived using the Discrete Fourier Transform (DFT). These approximate results are equal to the exact CRB when the DFT coefficients are mutually uncorrelated. Previous high SNR limits for CRB's are shown to be inaccurate because the discrete summations cannot be approximated with integration. The performance of an approximate maximum likelihood estimator for mean frequency approaches the exact CRB for moderate signal to noise ratio and moderate spectral width.
Ackermann, Mark R [Albuquerque, NM; McGraw, John T [Placitas, NM; Zimmer, Peter C [Albuquerque, NM
2008-01-15
A wide field of view telescope having two concave and two convex reflective surfaces, each with an aspheric surface contour, has a flat focal plane array. Each of the primary, secondary, tertiary, and quaternary reflective surfaces are rotationally symmetric about the optical axis. The combination of the reflective surfaces results in a wide field of view in the range of approximately 3.8.degree. to approximately 6.5.degree.. The length of the telescope along the optical axis is approximately equal to or less than the diameter of the largest of the reflective surfaces.
The formation of low-ionization emission in the halo of NGC 891
NASA Technical Reports Server (NTRS)
Sokolowski, James; Bland-Hawthorn, Jonathan
1993-01-01
Imaging and Spectroscopic study first revealed the presence of a diffuse ionized medium (DIM), having unusual excitation, pervading the lower halo of the edge-on spiral galaxy NGC 891. Emission from this DIM is strongest northeast of the nucleus, at radii between 2 and 8 kpc (hereafter region 1). The (N2)(lambda)6583/H(alpha) and (S2)(lambda) (lambda)6716,6731/H(alpha) ratios increase dramatically with z in region 1, from 0.6 and 0.5 respectively at z is approximately equal to 500 pc to 1.1 and 1.0 at z is approximately equal to 1 kpc, while nondetections of (O1)(lambda)6300 and (O3)(lambda)5007 emission yield upper limits of (O1)(lambda)6300/H(alpha) less than or equal to 0.05 and (O3)(lambda)5007/H(alpha) less than or equal to 0.15 for z less than 1 kpc. Previous photoionization models, using the radiation field from disk O and B stars, have been successful in reproducing the elevated (N2)(lambda)6583/H(alpha) and (S2)(lambda)(lambda)6716.6731/H(alpha) ratios observed. However, these radiation bounded models also produce significant (O3)(lambda)5007 emission, in conflict with the observed upper limit. Here, we report the results of new, matter bounded models for the photoionization of the DIM in region 1 of NGC 891.
The Surface Brightness Contribution of II Peg: A Comparison of TiO Band Analysis and Doppler Imaging
NASA Astrophysics Data System (ADS)
Senavci, H. V.; O'Neal, D.; Hussain, G. A. J.; Barnes, J. R.
2015-01-01
We investigate the surface brightness contribution of the very well known active SB1 binary II Pegasi , to determine the star spot filling factor and the spot temperature parameters. In this context, we analyze 54 spectra of the system taken over 6 nights in September - October of 1996, using the 2.1m Otto Struve Telescope equipped with SES at the McDonald Observatory. We measure the spot temperatures and spot filling factors by fitting TiO molecular bands in this spectroscopic dataset, with model atmosphere approximation using ATLAS9 and with proxy stars obtained with the same instrument. The same dataset is then used to also produce surface spot maps using the Doppler imaging technique. We compare the spot filling factors obtained with the two independent techniques in order to better characterise the spot properties of the system and to better assess the limitations inherent to both techniques. The results obtained from both techniques show that the variation of spot filling factor as a function of phase agree well with each other, while the amount of TiO and DI spot
A comparison of tracking with visual and kinesthetic-tactual displays
NASA Technical Reports Server (NTRS)
Jagacinski, R. J.; Flach, J. M.; Gilson, R. D.
1981-01-01
Recent research on manual tracking with a kinesthetic-tactual (KT) display suggests that under appropriate conditions it may be an effective means of providing visual workload relief. In order to better understand how KT tracking differs from visual tracking, both a critical tracking task and stationary single-axis tracking tasks were conducted with and without velocity quickening. On the critical tracking task, the visual displays were superior; however, the KT quickened display was approximately equal to the visual unquickened display. Mean squared error scores in the stationary tracking tasks for the visual and KT displays were approximately equal in the quickened conditions, and the describing functions were very similar. In the unquickened conditions, the visual display was superior. Subjects using the unquickened KT display exhibited a low frequency lead-lag that may be related to sensory adaptation.
Comparison of the biological H2S removal characteristics among four inorganic packing materials.
Hirai, M; Kamamoto, M; Yani, M; Shoda, M
2001-01-01
Four inorganic packing materials were evaluated in terms of their availability as packing materials of a packed tower deodorization apparatus (biofilter) from the viewpoints of biological H2S removal characteristics and some physical properties. Among porous ceramics (A), calcinated cristobalite (B), calcinated and formed obsidian (C), granulated and calcinated soil (D), the superiority of these packing materials determined based on the values of non-biological removal per unit weight or unit volume of packing material, complete removal capacity of H2S per unit weight of packing material per day or unit volume of packing material per day and pressure drop of the packed bed was in the order of A approximately equal to C > D approximately equal to B, which is correlated with the maximum water content, porosity, and mean pore diameter.
Trends of Measured Climate Forcing Agents
NASA Technical Reports Server (NTRS)
Hansen, James E.; Sato, Makiko; Einaudi, Franco (Technical Monitor)
2002-01-01
The growth rate of climate forcing by measured greenhouse gases peaked near 1980 at almost 5 W/sq m per century. This growth rate has since declined to approximately equal to 3 W/sq m per century, largely because of cooperative international actions. We argue that trends can be reduced to the level needed for the moderate "alternative" climate scenario (approximately equal to 2 W/M2 per century for the next 50 years) by means of concerted actions that have other benefits, but the forcing reductions are not automatic "co-benefits" of actions that slow CO2 emissions. Current trends of climate forcings by aerosols remain very uncertain. Nevertheless, practical constraints on changes in emission levels suggest that global warming at a rate + 0.15 +/- 0.05 C per decade will occur over the next several decades.
Comparison of C-band and Ku-band scatterometry for medium-resolution tropical forest inventory
NASA Astrophysics Data System (ADS)
Hardin, Perry J.; Long, David G.
1993-08-01
Since 1978, AVHRR imagery from NOAA polar orbiters has provided coverage of tropical regions at this desirable resolution, but much of the imagery is plagued with heavy cloud cover typical of equatorial regions. Clearly a medium resolution radar sensor would be a useful addition to AVHRR, but none are planned to fly in the future. In contrast, scatterometers are an important radar component of many future earth remote sensing systems, but the inherent resolution of these instruments is too low (approximately equals 50 km) for monitoring earth's land surfaces. However, a recently developed image reconstruction technique can increase the spatial resolution of scatterometer data to levels (approximately equals 4 to 14 km) approaching AVHRR global area coverage (approximately equals 4 km). When reconstructed, scatterometer data may prove to be an important asset in evaluating equatorial land cover. In this paper, the authors compare the utility of reconstructed Seasat scatterometer (SASS), Ku-band microwave data to reconstructed ERS-1 C-band scatterometer imagery for discrimination and monitoring of tropical vegetation formations. In comparative classification experiments conducted on reconstructed images of Brasil, the ERS-1 C-band imagery was slightly superior to its reconstructed SASS Ku-band counterpart for discriminating between several equatorial land cover classes. A classification accuracy approaching .90 was achieved when the two scatterometer images were combined with an AVHRR normalized difference vegetation index (NDVI) image. The success of these experiments indicates that further research into reconstructed image applications to tropical forest monitoring is warranted.
NASA Technical Reports Server (NTRS)
Talbot, Robert W.; Dibb, Jack E.
1999-01-01
The SASS Ozone and Nitrogen Oxides Experiment (SONEX) over the North Atlantic during October/November 1997 offered an excellent opportunity to examine the budget of total reactive nitrogen (NO(sub y)) in the upper troposphere (8 - 12 km altitude). The median measured NO(sub y) mixing ratio was 425 parts per trillion by volume (pptv). Two different methods were used to measure HNO3: (1) the mist chamber technique and, (2) chemical ionization mass spectrometry. Two merged data sets using these HNO3 measurements were used to calculate NO(sub y) by summing the reactive nitrogen species (a combination of measured plus modeled results) and comparing the resultant values to measured NO(sub y) (gold catalytic reduction method). Both comparisons showed good agreement in the two quantities (slope > 0.9 and r(exp 2) > 0.9). Thus, the total reactive nitrogen budget in the upper troposphere over the North Atlantic can be explained in a general manner as a simple mixture of NO(sub x). (NO + NO2), HNO3, and PAN. Median values of NO(sub x)/NO(sub y) were approximately equal to 0.25, HNO3/NO(sub y) were approximately equal to 0.35 and Peroxyacetyl Nitrate (PAN)/NO(sub y) were approximately equal to 0. 17. Particulate NO3 and alkyl nitrates together composed <10 % of NO(sub y), while model estimated HNO4 averaged 12%.
NASA Technical Reports Server (NTRS)
Alpert, Yakov L.
1991-01-01
The altitude dependencies of the moduli of the electric field E in the VLF and LF frequency bands (f sub B much less than F less than f sub B) and in the altitude range of the ionosphere Z equals (400 to 2500) km up to Z equals 6000 km (the bottom of the magnetosphere) were calculated by the linear theory. The amplitudes of the field have large maxima in four regions: the axis field (E sub o) close to the direction of the Earth's magnetic field line B sub o, beta approximately 0 degrees, the fields (E sub St), (E sub RevSt) and (E sub Res) in the Storey, Reversed Story and Resonance cones, beta approximately (0 approaches 20) degrees. Their maxima are very pronounced close to the low hybrid frequency F sub L. The nonlinear heating of the magnetoplasma under the action of an electric field Ee (sup iwt) was recently expanded by the macroscopic theory by the author. The velocities, collision frequencies and temperatures of all the constituents of a magnetoplasma - electrons, ions, and neutral particles - are taken into account. Formulae and numerical results are presented for the ionosphere in the frequency band F equals (1 to 10 exp 4) kHz and altitude range Z approximately (100 - 1000) km. Some results of calculations by the self consistent solution of the basis system of equations are also discussed.
Very High Current Density Nb/AlN/Nb Tunnel Junctions for Low-Noise Submillimeter Mixers
NASA Technical Reports Server (NTRS)
Kawamura, Jonathan; Miller, David; Chen, Jian; Zmuidzinas, Jonas; Bumble, Bruce; LeDuc, Henry G.; Stern, Jeff A.
2000-01-01
We have fabricated and tested submillimeter-wave superconductor-insulator-superconductor (SIS) mixers using very high current density Nb/AlN/Nb tunnel junctions (J(sub c) approximately equal 30 kA/sq cm) . The junctions have low resistance-area products (R(sub N)A approximately 5.6 Omega.sq micron), good subgap to normal resistance ratios R(sub sg)/R(sub N) approximately equal 10, and good run-to-run reproducibility. From Fourier transform spectrometer measurements, we infer that omega.R(sub N)C = 1 at 270 GHz. This is a factor of 2.5 improvement over what is generally available with Nb/AlO(x)/Nb junctions suitable for low-noise mixers. The AlN-barrier junctions are indeed capable of low-noise operation: we measure an uncorrected receiver noise temperature of T(sub RX) = 110 K (DSB) at 533 GHz for an unoptimized device. In addition to providing wider bandwidth operation at lower frequencies, the AlN-barrier junctions will considerably improve the performance of THz SIS mixers by reducing RF loss in the tuning circuits.
Directional Radio-Frequency Identification Tag Reader
NASA Technical Reports Server (NTRS)
Medelius, Pedro J.; Taylor, John D.; Henderson, John J.
2004-01-01
A directional radio-frequency identification (RFID) tag reader has been designed to facilitate finding a specific object among many objects in a crowded room. The device could be an adjunct to an electronic inventory system that tracks RFID-tagged objects as they move through reader-equipped doorways. Whereas commercial RFID-tag readers do not measure directions to tagged objects, the device is equipped with a phased-array antenna and a received signal-strength indicator (RSSI) circuit for measuring direction. At the beginning of operation, it is set to address only the RFID tag of interest. It then continuously transmits a signal to interrogate that tag while varying the radiation pattern of the antenna. It identifies the direction to the tag as the radiation pattern direction of peak strength of the signal returned by the tag. An approximate distance to the tag is calculated from the peak signal strength. The direction and distance can be displayed on a screen. A prototype containing a Yagi antenna was found to be capable of detecting a 915.5-MHz tag at a distance of approximately equal to 15 ft (approximately equal to 4.6 m).
A source with a 10{sup 13} DT neutron yield on the basis of a spherical plasma focus chamber
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zavyalov, N. V.; Maslov, V. V.; Rumyantsev, V. G., E-mail: rumyantsev@expd.vniief.ru
2013-03-15
Results from preliminary experimental research of neutron emission generated by a spherical plasma focus chamber filled with an equal-component deuterium-tritium mixture are presented. At a maximum current amplitude in the discharge chamber of {approx}1.5 MA, neutron pulses with a full width at half-maximum of 75-80 ns and an integral yield of {approx}1.3 Multiplication-Sign 10{sup 13} DT neutrons have been recorded.
Silver Recycling in the United States in 2000
Hilliard, Henry E.
2003-01-01
In 2000, the global silver supply deficit (the difference between mine and scrap supply and silver demand) was more than 3,000 metric tons. U.S. silver demand for photographic applications alone was nearly equal to annual U.S. silver production. Until 1968, the U.S. silver deficit was filled by withdrawals from the U.S. Treasury reserves. In 2000, the deficit was filled by destocking, imports, and recycling. Photographic wastes, spent catalysts, and electronic scrap are the major sources of materials for silver recycling. Nearly 1,800 tons of silver contained in these materials were available for recycling in 2000. Other recyclable silver-bearing materials include dental alloys, jewelry, and silverware. In 2000, an estimated 1,700 tons of silver were recovered from secondary sources in the United States. The U.S. recycling efficiency for old scrap was calculated to have been 97 percent in 2000; the recycling rate was estimated to be 32 percent.
Silver recycling in the United States in 2000
Hilliard, Henry E.
2003-01-01
In 2000, the global silver supply deficit (the difference between mine and scrap supply and silver demand) was more than 3,000 metric tons. U.S. silver demand for photographic applications alone was nearly equal to annual U.S. silver production. Until 1968, the U.S. silver deficit was filled by withdrawals from the U.S. Treasury reserves. In 2000, the deficit was filled by destocking, imports, and recycling. Photographic wastes, spent catalysts, and electronic scrap are the major sources of materials for silver recycling. Nearly 1,800 metric tons of silver contained in these materials were available for recycling in 2000. Other recyclable silver-bearing materials include dental alloys, jewelry, and silverware. In 2000, an estimated 1,700 tons of silver were recovered from secondary sources in the United States. The U.S. recycling efficiency for old scrap was calculated to have been 97 percent in 2000; the recycling rate was estimated to be 32 percent.
Stable density stratification solar pond
NASA Technical Reports Server (NTRS)
Lansing, F. L. (Inventor)
1985-01-01
A stable density-stratification solar pond for use in the collection and storage of solar thermal energy including a container having a first section characterized by an internal wall of a substantially cylindrical configuration and a second section having an internal wall of a substantially truncated conical configuration surmounting the first section in coaxial alignment therewith, the second section of said container being characterized by a base of a diameter substantially equal to the diameter of the first section and a truncated apex defining a solar energy acceptance opening is discussed. A body of immiscible liquids is disposed within the container and comprises a lower portion substantially filling the first section of the container and an upper portion substantially filling the second section of the container, said lower portion being an aqueous based liquid of a darker color than the upper portion and of a greater density. A protective cover plate is removably provided for covering the acceptance opening.
Mark, Tami L; Dilonardo, Joan; Vandivort, Rita; Miller, Kay
2013-01-01
This study describes the comorbidities and health care utilization of individuals treated with buprenorphine using the 2007-2009 MarketScan Research Databases. Buprenorphine recipients had a high prevalence of comorbidities associated with chronic pain, including back problems (42%), connective tissue disease (24-27%), and nontraumatic joint disorders (20-23%). Approximately 69% of recipients filled prescriptions for opioid agonist medications in the 6 months before buprenorphine initiation. Buprenorphine recipients were frequently diagnosed with anxiety (23-42%) and mood disorders (39-51%) and filled prescriptions for antidepressants (47-56%) and benzodiazepines (47-56%) at high rates. Surprisingly, only 53-54% of patients filling a prescription for buprenorphine had a coded opioid abuse/dependence diagnosis. Research is needed to better understand buprenorphine's effectiveness in the context of prescription drug abuse and the best way to coordinate services to address the patient's comorbid addiction, pain, and psychiatric illnesses. Copyright © 2013 Elsevier Inc. All rights reserved.
NASA Astrophysics Data System (ADS)
Wang, Kai; Cao, Qing; Zhang, Huifang; Shen, Pengcheng; Xing, Lujing
2018-06-01
Based on the TE01 mode of a rectangular metal waveguide and the Gaussian mode of a fiber, we propose the cos-Gaussian mode of a terahertz rectangular metal waveguide filled with multiple slices of dielectric. First, we consider a rectangular metal waveguide filled with an ideal graded-index dielectric along one direction. Furthermore, we replace the graded-index dielectric with multiple slices of dielectric according to the effective medium theory. The modal field, the effective index, and the coupling efficiency of this waveguide are investigated. It is found that the approximately linearly polarized electric field is Gaussian along one dimensionality and cosine along the other one. In addition, the low loss and high coupling efficiency with a Gaussian beam can be acquired at 0.9 THz. By optimization, the coupling efficiency could reach 88.5%.
A Grammar of Inupiaq Morphosyntax
ERIC Educational Resources Information Center
Lanz, Linda A.
2010-01-01
This dissertation is a reference grammar of the Malimiut Coastal dialect of Inupiaq (ISO: ESI, ESK, IPK), an Eskimo-Aleut language of northwestern Alaska spoken by the Inupiat people. It complements existing descriptions of Inupiaq by filling gaps in documentation. With approximately 2000 speakers, mainly above 50 years of age, Inupiaq is…
CONTEXT VIEW FROM UNDER REAR OF HULETTS LOOKING OUT INTO ...
CONTEXT VIEW FROM UNDER REAR OF HULETTS LOOKING OUT INTO THE ORE YARD FILLED WITH ORE, SHOWING SELF-UNLOADING SHIP BOOM IN ACTION. LOOKING EAST. - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH
30 CFR 715.14 - Backfilling and grading.
Code of Federal Regulations, 2012 CFR
2012-07-01
... grade all spoil material to eliminate all highwalls, spoil piles, and depressions. Cut-and-fill terraces... approximate original contour, all highwalls, spoil piles, and depressions except as provided in paragraphs (d... the provisions of § 716.3 of this chapter. (d) Small depressions. The requirement of this section to...
30 CFR 715.14 - Backfilling and grading.
Code of Federal Regulations, 2013 CFR
2013-07-01
... grade all spoil material to eliminate all highwalls, spoil piles, and depressions. Cut-and-fill terraces... approximate original contour, all highwalls, spoil piles, and depressions except as provided in paragraphs (d... the provisions of § 716.3 of this chapter. (d) Small depressions. The requirement of this section to...
30 CFR 715.14 - Backfilling and grading.
Code of Federal Regulations, 2014 CFR
2014-07-01
... grade all spoil material to eliminate all highwalls, spoil piles, and depressions. Cut-and-fill terraces... approximate original contour, all highwalls, spoil piles, and depressions except as provided in paragraphs (d... the provisions of § 716.3 of this chapter. (d) Small depressions. The requirement of this section to...
Prevalence of periradicular periodontitis in a Scottish subpopulation found on CBCT images.
Dutta, A; Smith-Jack, F; Saunders, W P
2014-09-01
To investigate the prevalence of periradicular periodontitis (PRP) using cone-beam computed tomography (CBCT) scans in a retrospective cross-sectional epidemiological study in a Scottish subpopulation. Of the 319 CBCT scans performed at Dundee Dental Hospital between November 2009 and July 2012, 245 dentate scans of patients over 18 years of age were included and 3595 teeth examined. Odds ratios were calculated, and the association between root filling and posts with PRP was determined. Radiological signs of PRP were detected in 209 teeth (5.8%) in 96 patients (male = 53, female = 43) of which 145 (69.4%) were measurable and 64 (30.6%) appeared as periapical widening. Most lesions were seen in the 46-55-year age group and in maxillary anterior teeth (35.4%); 47.4% (n = 81) of the total root filled teeth (n = 171) had PRP. Of the root filled teeth with lesions, approximately half (50.6%) had an inadequate root filling. Teeth with crowns, but not root filled, accounted for 17.7% of PRP. Periapical changes were detected on a high proportion of teeth with post-retained crowns (70.7%). The presence of a root filling was significantly associated with PRP (z = 17.689 P < 0.0001; odds ratio 16.36 < 23.17 < 32.83, 95% CI) and the presence of a post (z = 10.901 P < 0.0001; odds ratio 21.36 < 41.8021 < 81.78, 95% CI). The prevalence of PRP in a Scottish subpopulation was 5.8%. The presence of a root filling or a post-retained crown was significantly associated with the presence of PRP as determined by CBCT scans. The prevalence of periradicular disease in root filled teeth remains high in the Scottish population. © 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.
NASA Astrophysics Data System (ADS)
Meng, Fanzhen; Zhou, Hui; Wang, Zaiquan; Zhang, Liming; Kong, Liang; Li, Shaojun; Zhang, Chuanqing
2017-08-01
Filled joints, which are characterized by high deformability and low shear strength, are among the most critical discontinuities in rock mass and may be sheared repeatedly when subject to cyclic loading. Shear tests were carried out on tension splitting joints, with soil and granular cement mortar particles used as infillings, and the effects of the shear history on the mechanical behavior and acoustic emission (AE) of clean and filled joints were studied. The maximum strength in the subsequent shears was approximately 60% of the peak strength of the first shear for a clean joint, and the friction angle degraded from 63° to 45° after the first shear. The maximum shear strength of the filled joints was lower than 35% of the peak strength of the clean joint under the same normal stress. The change in the shear strength of filled joints with the number of shearing cycles was closely related to the transformation of the shear medium. Rolling friction occurred and the shear strength was low for the granular particle-filled joint, but the strength was elevated when the particles were crushed and sliding friction occurred. The AEs were significantly reduced during the second shear for the clean joint, and the peak AEs were mainly obtained at or near the turning point of the shear stress curve for the filled joint. The AEs were the highest for the cement particle-filled joint and lowest for the dry soil-filled joint; when subjected to repeated shears, the AEs were more complex because of the continuous changes to the shear medium. The evolution of the AEs with the shear displacement can accurately reflect the shear failure mechanism during a single shear process.
NASA Technical Reports Server (NTRS)
Harris, Michael J.; Share, Gerald H.; Leising, Mark D.
1994-01-01
We have search spectra obtained by the Solar Maximum Mission Gamma-Ray Spectrometer during 1981-1988 for evidence of transient gamma-ray lines from the Crab Nebula which have been reported by previous experiments at energies 400-460 keV and 539 keV. We find no evidence for significant emission in any of these lines on time scales between aproximately 1 day and approximately 1 yr. Our 3 sigma upper limits on the transient flux during 1 d intervals are approximately equal to 2.2 x 10(exp -3) photons/sq cm/s for narrow lines at any energy, and approximately equal to 2.9 x 10(exp -3) photons/sq cm/s for the 539 keV line if it is as broad as 42 keV Full Width at Half Maximum (FWHM). We also searched our data during the approximately 5 hr period on 1981 June 6 during which Owens, Myers, & Thompson (1985) reported a strong line at 405 keV. We detected no line down to a 3 upper sigma limit of 3.3 x 10(exp -3) photons/sq cm/s in disagreement with the flux 7.2 +/- 2.1 x 10(exp -3) photos/sq cm/s measured by Owens et al.
NASA Technical Reports Server (NTRS)
Haas, J. E.; Roelke, R. J.; Hermann, P.
1981-01-01
The reasons for the low aerodynamic performance of a 13.5 cm tip diameter aircraft engine starter turbine were investigated. Both the stator and the stage were evaluated. Approximately 10 percent improvement in turbine efficiency was obtained when the honeycomb shroud over the rotor blade tips was filled to obtain a solid shroud surface. Efficiency improvements were obtained for three rotor configurations when the shroud was filled. It is suggested that the large loss associated with the open honeycomb shroud is due primarily to energy loss associated with gas transportation as a result of the blade to blade pressure differential at the tip section.
A rack is installed in MPLM Leonardo
NASA Technical Reports Server (NTRS)
2000-01-01
Workers inside the Multi-Purpose Logistics Module Leonardo check installation of a laboratory rack inside the Multi-Purpose Logistics Module Leonardo. The pressurized module is the first of three that will serve as the International Space Station's '''moving vans,''' carrying laboratory racks filled with equipment, experiments and supplies to and from the Space Station aboard the Space Shuttle. Approximately 21 feet long and 15 feet in diameter, Leonardo will be launched on Shuttle mission STS-102 March 1, 2001. On that flight, Leonardo will be filled with equipment and supplies to outfit the U.S. laboratory module, being carried to the ISS on the Jan. 19, 2001, launch of STS-98.
A rack is installed in MPLM Leonardo
NASA Technical Reports Server (NTRS)
2000-01-01
Workers inside the Multi-Purpose Logistics Module Leonardo check connections while installing a laboratory rack. Leonardo is the first of three such pressurized modules that will serve as the International Space Station's '''moving vans,''' carrying laboratory racks filled with equipment, experiments and supplies to and from the Space Station aboard the Space Shuttle. Approximately 21 feet long and 15 feet in diameter, Leonardo will be launched on Shuttle mission STS-102 March 1, 2001. On that flight, Leonardo will be filled with equipment and supplies to outfit the U.S. laboratory module, being carried to the ISS on the Jan. 19, 2001, launch of STS-98.
Forward multiple scattering corrections as function of detector field of view
NASA Astrophysics Data System (ADS)
Zardecki, A.; Deepak, A.
1983-06-01
The theoretical formulations are given for an approximate method based on the solution of the radiative transfer equation in the small angle approximation. The method is approximate in the sense that an approximation is made in addition to the small angle approximation. Numerical results were obtained for multiple scattering effects as functions of the detector field of view, as well as the size of the detector's aperture for three different values of the optical depth tau (=1.0, 4.0 and 10.0). Three cases of aperture size were considered--namely, equal to or smaller or larger than the laser beam diameter. The contrast between the on-axis intensity and the received power for the last three cases is clearly evident.
The relation between the Gross Pitaevskii and Bogoliubov descriptions of a dilute Bose gas
NASA Astrophysics Data System (ADS)
Leggett, A. J.
2003-07-01
I formulate a 'pseudo-paradox' in the theory of a dilute Bose gas with repulsive interactions: the standard expression for the ground state energy within the Gross-Pitaevskii (GP) approximation is lower than that in the Bogoliubov approximation, and hence, by the standard variational argument, the former should prima facie be a better approximation than the latter to the true ground state—a conclusion which is of course opposite to the established wisdom concerning this problem. It is shown that the pseudo-paradox is (unsurprisingly) resolved by a correct transcription of the two-body scattering theory to the many-body case; however, contrary to what appears to be a widespread belief, the resolution has nothing to do with any spurious ultraviolet divergences which result from the replacement of the true interatomic potential by a delta-function pseudopotential. Rather, it relates to an infrared divergence which has the consequence that (a) the most obvious form of the GP 'approximation' actually does not correspond to any well-defined ansatz for the many-body wavefunction, and (b) that the 'best shot' at such a wavefunction always produces an energy which exceeds, or at best equals, that calculated in the Bogoliubov approximation. In fact, the necessity of the latter may be seen as a consequence of the need to reduce the Fock term in the energy, which is absent in the two-particle problem but dominant in the many-body case; it does this by increasing the density correlations, at distances less than or approximately equal to the correlation length \\xi , above the value extrapolated from the two-body case. As a by-product I devise an alternative formulation of the Bogoliubov approximation which does not require the explicit replacement of the true interatomic potential by a delta-function pseudopotential.
Optimizing parameter of particle damping based on Leidenfrost effect of particle flows
NASA Astrophysics Data System (ADS)
Lei, Xiaofei; Wu, Chengjun; Chen, Peng
2018-05-01
Particle damping (PD) has strongly nonlinearity. With sufficiently vigorous vibration conditions, it always plays excellent damping performance and the particles which are filled into cavity are on Leidenfrost state considered in particle flow theory. For investigating the interesting phenomenon, the damping effect of PD on this state is discussed by the developed numerical model which is established based on principle of gas and solid. Furtherly, the numerical model is reformed and applied to study the relationship of Leidenfrost velocity with characteristic parameters of PD such as particle density, diameter, mass packing ratio and diameter-length ratio. The results indicate that particle density and mass packing ratio can drastically improve the damping performance as opposed as particle diameter and diameter-length ratio, mass packing ratio and diameter-length ratio can low the excited intensity for Leidenfrost state. For discussing the application of the phenomenon in engineering, bound optimization by quadratic approximation (BOBYQA) method is employed to optimize mass packing ratio of PD for minimize maximum amplitude (MMA) and minimize total vibration level (MTVL). It is noted that the particle damping can drastically reduce the vibrating amplitude for MMA as Leidenfrost velocity equal to the vibrating velocity relative to maximum vibration amplitude. For MTVL, larger mass packing ratio is best option because particles at relatively wide frequency range is adjacent to Leidenfrost state.
Bullard, S A; Frasca, S; Benz, G W
2001-10-01
Gill lesions associated with infections of Erpocotyle tiburonis (Brooks, 1934) (Monogenea: Hexabothriidae) on wild bonnethead sharks (Sphyrna tiburo (L., 1758) (Carcharhiniformes: Sphyrinidae)) were compared with those on aquarium-held ones using light and scanning electron microscopy. Uninfected gill filaments had slender, triangular, smooth-surfaced lamellae and interlamellar water channels that were approximately equal in size. Four wild sharks were each infected by 3-11 widely separated adult E. tiburonis, and 1 of these sharks hosted a juvenile specimen. Lamellae flanking or touching adult E. tiburonis were pushed aside or bent, but were otherwise identical to those of uninfected filaments. Two aquarium-held sharks were each infected by hundreds of juvenile and adult E. tiburonis. In these sharks, lamellae near juveniles were pushed apart or bent, but were otherwise normal, whereas a thick, ragged-surfaced layer of hyperplastic epithelium both filled interlamellar water channels and partially or completely covered lamellae near adults. Results of this study suggest that the intense infections of E. tiburonis were facilitated by captivity and caused severe hyperplastic lesions that ultimately led to the death of the sharks by reducing or blocking the respiratory water flow over lamellae and thus reducing the exchange of gases and ions across the lamellar epithelium. In contrast, the wild sharks were infected by fewer worms and exhibited relatively minor lesions.
The interaction between hot and cold gas in early-type galaxies
NASA Technical Reports Server (NTRS)
Bregman, Joel N.; Hogg, David E.; Roberts, Morton S.
1995-01-01
SO and Sa galaxies have approximately equal masses of H I and X-ray emitting gas and are ideal sites for studying the interaction between hot and cold gas. An X-ray observation of the Sa galaxy NGC 1291 with the ROSAT position sensitive proportional counter (PSPC) shows a striking spatial anticorrelation between hot and cold gas where X-ray emitting material fills the large central black hole in the H I disk. This supports a previous suggestion that hot gas is a bulge phenomenon and neutral hydrogen is a disk phenomenon. The X-ray luminosity (1.5 x 10(exp 40) ergs/s) and radial surface brightness distribution (beta = 0.51) is the same as for elliptical galaxies with optical luminosities and velocity dispersions like that of the bulge of NGC 1291. Modeling of the X-ray spectrum requires a component with a temperature of 0.15 keV, similar to that expected from the velocity dispersion of the stars, and with a hotter component where kT = 1.07 keV. This hotter component is not due to emission from stars and its origin remains unclear. PSPC observations are reported for the SO NGC 4203, where a nuclear point source dominates the emission, preventing a study of the radial distribution of the hot gas relative to the H I.
NASA Astrophysics Data System (ADS)
Rodrıguez-Guzmán, R.; Robledo, L. M.
2017-12-01
The parametrization D1M of the Gogny energy density functional is used to study fission in the odd-mass Uranium and Plutonium isotopes with A=233, \\ldots , 249 within the framework of the Hartree-Fock-Bogoliubov (HFB) Equal Filling Approximation (EFA). Ground state quantum numbers and deformations, pairing energies, one-neutron separation energies, barrier heights and fission isomer excitation energies are given. Fission paths, collective masses and zero point rotational and vibrational quantum corrections are used to compute the systematic of the spontaneous fission half-lives t_{SF}, the masses and charges of the fission fragments as well as their intrinsic shapes. Although there exits a strong variance of the predicted fission rates with respect to the details involved in their computation, it is shown that both the specialization energy and the pairing quenching effects, taken into account fully variationally within the HFB-EFA blocking scheme, lead to larger spontaneous fission half-lives in odd-mass U and Pu nuclei as compared with the corresponding even-even neighbors. It is shown that modifications of a few percent in the strengths of the neutron and proton pairing fields can have a significant impact on the collective masses leading to uncertainties of several orders of magnitude in the predicted t_{SF} values. Alpha-decay lifetimes have also been computed using a parametrization of the Viola-Seaborg formula.
NASA Astrophysics Data System (ADS)
Stigebrandt, Anders
1990-10-01
Baroclinic water exchange through a fjord mouth, driven by a slowly varying density field outside the mouth, is modelled by a simple quasi-steady frictionless model. It is assumed that a certain fraction of the horizontal pressure difference between the coastal water and the fjord is used to accelerate the fluid into the mouth. The continuous vertical density distribution in the fjord, which changes in response to the water exchange, is modelled using a time-dependent, one-dimensional advective-diffusive 'filling-box' type of model. The model has been tested against an almost one-year-long time series of salinity and temperature from the Ørsta fjord (horizontal surface area about 15km2) on the Norwegian west coast. It is found that for this particular fjord, the mean externally forced baroclinic water exchange is one order of magnitude greater than the mean water exchange driven by the estuarine circulation (600 and 60m3 s
1 respectively). Such a vigorous water exchange between a fjord and the external area implies that the time-averaged concentrations of many biological and chemical species above the sill level in the fjord are approximately equal to those in the coastal water outside the fjords.
Relation between the ion size and pore size for an electric double-layer capacitor.
Largeot, Celine; Portet, Cristelle; Chmiola, John; Taberna, Pierre-Louis; Gogotsi, Yury; Simon, Patrice
2008-03-05
The research on electrochemical double layer capacitors (EDLC), also known as supercapacitors or ultracapacitors, is quickly expanding because their power delivery performance fills the gap between dielectric capacitors and traditional batteries. However, many fundamental questions, such as the relations between the pore size of carbon electrodes, ion size of the electrolyte, and the capacitance have not yet been fully answered. We show that the pore size leading to the maximum double-layer capacitance of a TiC-derived carbon electrode in a solvent-free ethyl-methylimmidazolium-bis(trifluoro-methane-sulfonyl)imide (EMI-TFSI) ionic liquid is roughly equal to the ion size (approximately 0.7 nm). The capacitance values of TiC-CDC produced at 500 degrees C are more than 160 F/g and 85 F/cm(3) at 60 degrees C, while standard activated carbons with larger pores and a broader pore size distribution present capacitance values lower than 100 F/g and 50 F/cm(3) in ionic liquids. A significant drop in capacitance has been observed in pores that were larger or smaller than the ion size by just an angstrom, suggesting that the pore size must be tuned with sub-angstrom accuracy when selecting a carbon/ion couple. This work suggests a general approach to EDLC design leading to the maximum energy density, which has been now proved for both solvated organic salts and solvent-free liquid electrolytes.
NASA Technical Reports Server (NTRS)
Tripp, Todd M.; Giroux, Mark L.; Stocke, John T.; Tumlinson, Jason; Oegerle, William R.; Fisher, Richard R. (Technical Monitor)
2001-01-01
We use high-resolution UV (ultraviolet) spectra of the radio-quiet QSO (quasi-stellar object) H1821+643 (z(sub em) = 0.297), obtained with the Space Telescope Imaging Spectrograph (STIS) and the Far Ultraviolet Spectroscopic Explorer (FUSE), to study the ionization and metallicity of an intervening O VI absorption line system at z(sub abs) = 0.1212. This absorber has the following notable properties: (1) Several galaxies are close to the sight line at the absorber redshift, including an actively star-forming galaxy at a projected distance of 144 h(sub 75)(exp -1) kpc. (2) There is a complex cluster of H I Ly(alpha) absorption lines near the O VI redshift, including at least five components spread over a velocity range of approximately 700 km s(exp -1). (3) The strongest Ly(alpha) line in the cluster appears to be composed of a mildly saturated component with a typical b-value blended with a remarkably broad component with b approximately equals 85 km s(exp -1). (4) The O VI absorption is not aligned with the strongest (saturated) H I absorption, but instead is well-aligned with the very broad component. (5) The only detected species (at the 4(sigma) level) are O VI and H I despite coverage of strong transitions of abundant elements (e.g., C II, C III, and C IV). Based on these constraints, we find that the absorption line properties can be produced in collisionally ionized gas with 10(exp 5.3) is equal to or less than T is equal to or less than 10(exp 5.6) K and -1.8 is equal to or less than [O/H] is equal to or less than -0.6. However, we find that photoionization is also viable if the pathlength l through the absorbing gas is long enough; simple photoionization models require 85 is equal to or less than l is equal to or less than 1900 kpc and -1.1 is equal to or less than [O/H] is equal to or less than -0.3. We briefly discuss how observations of X-ray absorption lines due to O VII and O VIII could be used, in principle, to break the ionization mechanism degeneracy, and we conclude with some comments regarding the nature of O VI absorbers.
Hangai, Yoshihiko; Saito, Masaki; Utsunomiya, Takao; Kitahara, Soichiro; Kuwazuru, Osamu; Yoshikawa, Nobuhiro
2014-09-19
Aluminum foam has received considerable attention in various fields and is expected to be used as an engineering material owing to its high energy absorption properties and light weight. To improve the mechanical properties of aluminum foam, combining it with dense tubes, such as aluminum foam-filled tubes, was considered necessary. In this study, an aluminum foam-filled steel tube, which consisted of ADC12 aluminum foam and a thin-wall steel tube, was successfully fabricated by friction welding. It was shown that a diffusion bonding layer with a thickness of approximately 10 μm was formed, indicating that strong bonding between the aluminum foam and the steel tube was realized. By the X-ray computed tomography observation of pore structures, the fabrication of an aluminum foam-filled tube with almost uniform pore structures over the entire specimen was confirmed. In addition, it was confirmed that the aluminum foam-filled steel tube exhibited mechanical properties superior to those of the ADC12 aluminum foam and steel tube. This is considered to be attributed to the combination of the aluminum foam and steel tube, which particularly prevents the brittle fracture and collapse of the ADC12 foam by the steel tube, along with the strong metal bonding between the aluminum foam and the steel tube.
A study of the discrepant QSO X-ray luminosity function from the HEAO-2 data archive
NASA Technical Reports Server (NTRS)
Margon, B.
1986-01-01
Sensitive X-ray information for approximately 90 previously uncataloged Quasi-Stellar Objects (QSOs) in the redshift range 1.8 is less than or equal to z which is less than or equal to 3. Even with the longest esixting Einstein Observatory X-ray exposures, only 25% of these objects are positively detected in X-rays. The data were used to investigate the ensemble X-ray properties of high redshift QSOs, and the QSO population in general.
CDC6600 subroutine for normal random variables. [RVNORM (RMU, SIG)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Amos, D.E.
1977-04-01
A value y for a uniform variable on (0,1) is generated and a table of 96-percent points for the (0,1) normal distribution is interpolated for a value of the normal variable x(0,1) on 0.02 less than or equal to y less than or equal to 0.98. For the tails, the inverse normal is computed by a rational Chebyshev approximation in an appropriate variable. Then X = x sigma + ..mu.. gives the X(..mu..,sigma) variable.
Numerical Field Model Simulation of Fire and Heat Transfer in a Rectangular Compartment
1992-09-01
zero . However, due to the approximation inherent in the numerical scheme, we will be satisfied if S,, tends toward zero as determined by comparison... zero , the appropriate coefficient (A) corresponding to that boundary is also set equal to zero . After the local pressure correction (P’) is determined...chamber just prior to starting the fire. It is assumed that the air is uni- formly at rest, thus all components of velocity are set equal to zero
ROSAT X-ray sources embedded in the rho Ophiuchi cloud core
NASA Astrophysics Data System (ADS)
Casanova, Sophie; Montmerle, Thierry; Feigelson, Eric D.; Andre, Philippe
1995-02-01
We present a deep ROSAT Position Sensitive Proportional Counter (PSPC) image of the central region of the rho Oph star-forming region. The selected area, about 35 x 35 arcmins in size, is rich with dense molecular cores and young stellar objects (YSOs). Fifty-five reliable X-ray sources are detected (and up to 50 more candidates may be present) above approximately 1 keV,, doubling the number of Einstein sources in this area. These sources are cross-identified with an updated list of 88 YSOs associated with the rho Oph cloud core. A third of the reliable X-ray sources do not have optical counterparts on photographic plates. Most can be cross-identified wth Class II and Class III infrared (IR) sources, which are embedded T Tauri stars, but three reliable X-ray sources and up to seven candidate sources are tentatively identified with Class I protostars. Eighteen reliable, and up to 20 candidate, X-ray sources are probably new cloud members. The overall detection rate of the bona fide cloud population is very high (73% for the Class II and Class III objects). The spatial distribution of the X-ray sources closely follows that of the moleclar gas. The visual extinctions Av estimated from near-IR data) of the ROSAT sources can be as high as 50 or more, confirming that most are embedded in the cloud core and are presumably very young. Using bolometric luminosities Lbol estimated from J-magnitudes a tight correlation between Lx and Lbol is found, similar to that seen for older T Tauri stars in the Cha I cloud: Lx approximately 10-4 Lbol. A general relation Lxproportional to LbolLj seems to apply to all T Tauri-like YSOs. The near equality of the extintion in the IR J band and in the keV X-ray rage implies that this relation is valid for the detected fluxes as well as for the dereddened fluxes. The X-ray luminosity function of the embedded sourced in rho Oph spans a range of Lx approximately 1028.5 to approximately equal to or greater than 1031.5 ergs/s and is statistically indistinguishable from that of X-ray-detected visile T Tauri stars. We estimate a total X-ray luminosity Lx, Oph approximately equal to or greater than 6 x 10 32 ergs/s from approximately equal to 200 X-ray sources in the cloud core, down to Lbol approximately 0.1 solar luminosity or Mstar approximately 0.3 solar mass. We discuss several consequences of in situ irradiation of molecular clouds by X-rays from embedded YSOs. These X-rays must partially ionize the inner regions of circumstellar disk coronae, possibly playing an important role in coupling magnetic ionize the fields and wind or bipolar outflows. Photon-stimulated deportion of large molecules by YSO X-rays may be partly responsible for the bright 12 micrometer halos seen in some molecular clouds.
Blind equalization with criterion with memory nonlinearity
NASA Astrophysics Data System (ADS)
Chen, Yuanjie; Nikias, Chrysostomos L.; Proakis, John G.
1992-06-01
Blind equalization methods usually combat the linear distortion caused by a nonideal channel via a transversal filter, without resorting to the a priori known training sequences. We introduce a new criterion with memory nonlinearity (CRIMNO) for the blind equalization problem. The basic idea of this criterion is to augment the Godard [or constant modulus algorithm (CMA)] cost function with additional terms that penalize the autocorrelations of the equalizer outputs. Several variations of the CRIMNO algorithms are derived, with the variations dependent on (1) whether the empirical averages or the single point estimates are used to approximate the expectations, (2) whether the recent or the delayed equalizer coefficients are used, and (3) whether the weights applied to the autocorrelation terms are fixed or are allowed to adapt. Simulation experiments show that the CRIMNO algorithm, and especially its adaptive weight version, exhibits faster convergence speed than the Godard (or CMA) algorithm. Extensions of the CRIMNO criterion to accommodate the case of correlated inputs to the channel are also presented.
Electro-mechanical Properties of Carbon Nanotubes: Effect of Small Tensile and Torsional Strains
NASA Technical Reports Server (NTRS)
Anantram, M. P.; Yang, Liu; Han, Jie; Liu, J. P.; Saini, Subhash (Technical Monitor)
1999-01-01
We present a simple picture to calculate the bandgap ($E_g$) of carbon nanotubes (CNT) in the presence of uniform torsional and tensile strain ($\\sigma$). We find that under tensile strain, $ absolute value of dE_g/d\\sigma$ of zig-zag tubes is approximately equal to $3t_0$, where $t_0$ is the hopping parameter. Further, $ absolute value of dE_g/d\\sigma$ decreases as the chirality changes to armchair, where it takes the value zero. The sign of $dE_g/d\\sigma$ follows the $(N_x-N_y) *mod 3$(equal to - 1, 0 and +1) rule. In contrast to the above, we show that under torsional strain, $absolute value of dE_g/d\\sigma$ of armchair tubes is approximately equal to $3t_0$ and continually decreases as the chirality changes to zig-zag, where is takes a small value. The sign of $dE_g/d\\sigma$ again follows the $(N_x-N_y)*mod 3$ rule. Finally, we predict a change in the sign of $dE_g/d\\sigma$ as function of strain, corresponding to a change in the value of $q$ that corresponds to the bandgap minimum.
Chemical properties which control selectivity and efficacy of aromatic N-oxide bioreductive drugs.
Wardman, P.; Priyadarsini, K. I.; Dennis, M. F.; Everett, S. A.; Naylor, M. A.; Patel, K. B.; Stratford, I. J.; Stratford, M. R.; Tracy, M.
1996-01-01
Pulse radiolysis was used to generate radicals from one electron reduction of 1,2,4-benzotriazine-1,4-dioxides (derivatives of tirapazamine), and of imidazo [1,2-a]quinoxaline-4-oxides (analogues of RB90740), which have selective toxicity towards hypoxic cells. Radicals from the mono N-oxides (from the latter compounds) react with oxygen approximately 10-40 times faster than does the tirapazamine radical. Radicals from the tirapazamine analogues studied react with oxygen up to approximately 10 times slower than tirapazamine radicals. The quinoxaline N-oxide radicals are involved in prototropic equilibria with pK(a) values (5.5 to 7.4) spanning that reported for tirapazamine (6.0). Generation of radicals radiolytically in the presence of H donors (formate, 2-propanol, deoxyribose) indicate a chain reaction ascribed to H abstraction by the drug radical. The protonated drug radical is much more reactive than the radical anion (H abstraction rate constant approximately equal to 10(2) - 10(3) dm3 mol-1 s-1). Chain termination is ascribed to drug radical-radical reactions, i.e. radical stability in anoxia, with rate constants 2k approximately equal to 1 x 10(7) to 2 x 10(8) dm3 mol-1 s-1 at pH approximately 7.4. Estimates of the reduction potentials of the drug-radical couples in water at pH 7 for two of the mono-N-oxides were in the range-0.7 to 0.8 V vs NHE at pH 7. PMID:8763850
Active magnetic refrigerants based on Gd-Si-Ge material and refrigeration apparatus and process
Gschneidner, Jr., Karl A.; Pecharsky, Vitalij K.
1998-04-28
Active magnetic regenerator and method using Gd.sub.5 (Si.sub.x Ge.sub.1-x).sub.4, where x is equal to or less than 0.5, as a magnetic refrigerant that exhibits a reversible ferromagnetic/antiferromagnetic or ferromagnetic-II/ferromagnetic-I first order phase transition and extraordinary magneto-thermal properties, such as a giant magnetocaloric effect, that renders the refrigerant more efficient and useful than existing magnetic refrigerants for commercialization of magnetic regenerators. The reversible first order phase transition is tunable from approximately 30 K to approximately 290 K (near room temperature) and above by compositional adjustments. The active magnetic regenerator and method can function for refrigerating, air conditioning, and liquefying low temperature cryogens with significantly improved efficiency and operating temperature range from approximately 10 K to 300 K and above. Also an active magnetic regenerator and method using Gd.sub.5 (Si.sub.x Ge.sub.1-x).sub.4, where x is equal to or greater than 0.5, as a magnetic heater/refrigerant that exhibits a reversible ferromagnetic/paramagnetic second order phase transition with large magneto-thermal properties, such as a large magnetocaloric effect that permits the commercialization of a magnetic heat pump and/or refrigerant. This second order phase transition is tunable from approximately 280 K (near room temperature) to approximately 350 K by composition adjustments. The active magnetic regenerator and method can function for low level heating for climate control for buildings, homes and automobile, and chemical processing.
Active magnetic refrigerants based on Gd-Si-Ge material and refrigeration apparatus and process
Gschneidner, K.A. Jr.; Pecharsky, V.K.
1998-04-28
Active magnetic regenerator and method using Gd{sub 5} (Si{sub x}Ge{sub 1{minus}x}){sub 4}, where x is equal to or less than 0.5, as a magnetic refrigerant that exhibits a reversible ferromagnetic/antiferromagnetic or ferromagnetic-II/ferromagnetic-I first order phase transition and extraordinary magneto-thermal properties, such as a giant magnetocaloric effect, that renders the refrigerant more efficient and useful than existing magnetic refrigerants for commercialization of magnetic regenerators. The reversible first order phase transition is tunable from approximately 30 K to approximately 290 K (near room temperature) and above by compositional adjustments. The active magnetic regenerator and method can function for refrigerating, air conditioning, and liquefying low temperature cryogens with significantly improved efficiency and operating temperature range from approximately 10 K to 300 K and above. Also an active magnetic regenerator and method using Gd{sub 5} (Si{sub x} Ge{sub 1{minus}x}){sub 4}, where x is equal to or greater than 0.5, as a magnetic heater/refrigerant that exhibits a reversible ferromagnetic/paramagnetic second order phase transition with large magneto-thermal properties, such as a large magnetocaloric effect that permits the commercialization of a magnetic heat pump and/or refrigerant. This second order phase transition is tunable from approximately 280 K (near room temperature) to approximately 350 K by composition adjustments. The active magnetic regenerator and method can function for low level heating for climate control for buildings, homes and automobile, and chemical processing. 27 figs.
Zhang, Qiao; Jing, Dai; Zhang, Yufeng; Miron, Richard J
Bone grafting materials are frequently utilized in oral surgery and periodontology to fill bone defects and augment lost or missing bone. The purpose of this study was to compare new bone formation in bone defects created in both normal and osteoporotic animals loaded with three types of bone grafts from different origins. Forty-eight female Wistar rats were equally divided into control normal and ovariectomized animals. Bilateral 2.5-mm femur defects were created and filled with an equal weight of (1) natural bone mineral (NBM, BioOss) of bovine origin, (2) demineralized freeze-dried bone allograft (DFDBA, LifeNet), or (3) biphasic calcium phosphate (BCP, Vivoss). Following 3 and 6 weeks of healing, hematoxylin and eosin and TRAP staining was performed to determine new bone formation, material degradation, and osteoclast activity. All bone substitutes demonstrated osteoconductive potential at 3 and 6 weeks with higher osteoclast numbers observed in all ovariectomized animals. NBM displayed continual new bone formation with little to no sign of particle degradation, even in osteoporotic animals. DFDBA particles showed similar levels of new bone formation but rapid particle degradation rates with lower levels of mineralized tissue. BCP bone grafts demonstrated significantly higher new bone formation when compared with both NBM and DFDBA particles; however, the material was associated with higher osteoclast activity and particle degradation. Interestingly, in osteoporotic animals, BCP displayed synergistically and markedly more rapid rates of particle degradation. Recent modifications to synthetically fabricated materials were shown to be equally or more osteopromotive than NBM and DFDBA. However, the current BCP utilized demonstrated much faster resorption properties in osteoporotic animals associated with a decrease in total bone volume when compared with the slowly/nonresorbing NBM. The results from this study point to the clinical relevance of minimizing fast-resorbing bone grafting materials in osteoporotic phenotypes due to the higher osteoclastic activity and greater material resorption.
Very High Resolution Solar X-ray Imaging Using Diffractive Optics
NASA Technical Reports Server (NTRS)
Dennis, B. R.; Skinner, G. K.; Li, M. J.; Shih, A. Y.
2012-01-01
This paper describes the development of X-ray diffractive optics for imaging solar flares with better than 0.1 arcsec angular resolution. X-ray images with this resolution of the greater than or equal to 10 MK plasma in solar active regions and solar flares would allow the cross-sectional area of magnetic loops to be resolved and the coronal flare energy release region itself to be probed. The objective of this work is to obtain X-ray images in the iron-line complex at 6.7 keV observed during solar flares with an angular resolution as fine as 0.1 arcsec - over an order of magnitude finer than is now possible. This line emission is from highly ionized iron atoms, primarily Fe xxv, in the hottest flare plasma at temperatures in excess of approximately equal to 10 MK. It provides information on the flare morphology, the iron abundance, and the distribution of the hot plasma. Studying how this plasma is heated to such high temperatures in such short times during solar flares is of critical importance in understanding these powerful transient events, one of the major objectives of solar physics.We describe the design, fabrication, and testing of phase zone plate X-ray lenses with focal lengths of approximately equal to 100 m at these energies that would be capable of achieving these objectives. We show how such lenses could be included on a two-spacecraft formation-flying mission with the lenses on the spacecraft closest to the Sun and an X-ray imaging array on the second spacecraft in the focal plane approximately equal to 100 m away. High resolution X-ray images could be obtained when the two spacecraft are aligned with the region of interest on the Sun. Requirements and constraints for the control of the two spacecraft are discussed together with the overall feasibility of such a formation-flying mission.
Relaxation Phenomena in Optically Pumped Mercury Isotopes.
1981-08-31
transmitting envelope, containing a small quantity of 1991tg and 2 0 11g in approximately equal amounts. A variety of ultraviolet- transmitting glasses ...is male from a glass , Corning 9741. During the course of this project approximately 300 cells from a number of materials were made and tested in... glass and fused silica surfaces. The general pattern of the dependence of relaxation times as a function of temperature in "stable" NMR cells has
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mantese, J.V.
1986-01-01
Thin film metal-insulator composites were used to study how the resistivity and fluctuations in the resistivity were altered by changes in conduction mechanism so as to understand the source of the fluctuations and to better understand the conduction processes themselves. Metal-insulator composites were prepared by co-evaporation of platinum and aluminum oxide in a high vacuum system to create a series of films which had a range of metal volume fill fractions, p, from 23 to 100%. The samples were patterned using standard photolithographic techniques to form sample geometries of typical dimensions, length approx.40 ..mu..m, width approx.2 ..mu..m, and thickness approx.1500more » A. The resistivity rho, and power spectral density of the resistivity fluctuations, S/sub rho/(f), were measured as a function of p and temperature, T. Rho(p,T) was found to be a rapidly increasing function of decreasing p, rising monotonically by more than 7 orders of magnitude as p was decreased from 100% to 23%. For p greater than or equal to 59% the resistivity decreased linearly with decreasing temperature until limited by impurity scattering. The resistivities for the low metal fill fraction materials (P greater than or equal to 50%) increased as the temperature was reduced as expected of thermally assisted tunneling conduction in metal-insulator composites. The transition from metallic conduction to thermally assisted tunneling occurred at a critical value, p/sub c/, between 59% and 50% Pt.« less
Baryonic dark clusters in galactic halos and their observable consequences
NASA Technical Reports Server (NTRS)
Wasserman, Ira; Salpeter, Edwin E.
1994-01-01
We consider the possibility that approximately 10% of the mass of a typical galaxy halo is in the form of massive (approximately 10(exp 7) solar masses), compact (escape speeds approximately 100 km/s) baryonic clusters made of neutron stars (approximately 10% by mass), black holes (less than or approximately equal to 1%) and brown dwarfs, asteroids, and other low-mass debris (approximately 90%). These general properties are consistent with several different observational and phenomenological constraints on cluster properties subject to the condition that neutron stars comprise approximately 1% of the total halo mass. Such compact, dark clusters could be the sites of a variety of collisional phenomena involving neutron stars. We find that integrated out to the Hubble distance approximately one neutron star-neutron star or neutron star-black hole collision occurs daily. Of order 0.1-1 asteroid-neutron star collisions may also happen daily in the halo of the Milky Way if there is roughly equal cluster mass per logarithmic particle mass interval between asteroids and brown dwarfs. These event rates are comparable to the frequency of gamma-ray burst detections by the Burst and Transient Source Experiment (BATSE) on the Compton Observatory, implying that if dark halo clusters are the sites of most gamma-ray bursts, perhaps approximately 90% of all bursts are extragalactic, but approximately 10% are galactic. It is possible that dark clusters of the kind discussed here could be detected directly by the Infrared Space Observatory (ISO) or Space Infrared Telescope Facility (SIRTF). If the clusters considered in this paper exist, they should produce spatially correlated gravitational microlensing of stars in the Large Magellanic Cloud (LMC). If 10% of the halo is in the form of dark baryonic clusters, and the remaining 90% is in brown dwarfs and other dark objects which are either unclustered or collected into low-mass clusters, then we expect that two events within approximately 1 min of one another are likely to be seen after a total of order 20-30 microlenses have been detected.
NASA Astrophysics Data System (ADS)
Cunico, M. L.; Walder, J. S.; Fountain, A. G.; Trabant, D. C.
2001-12-01
During the summer of 2000, we measured displacements of 22 survey targets on the surface of Kennicott Glacier, Alaska, in the vicinity of Hidden Creek Lake, an ice-dammed lake in a tributary valley that fills and drains annually. Targets were distributed over a domain about equal in width to the lake, from near the glacier/lake margin to a distance of about 1 km from the margin. Targets were surveyed over a 24-day period as the lake filled and then drained. Lake stage was independently monitored. Vertical movement of targets generally fell off with distance d from the lake. As the lake filled, targets with d < 300 to 400 m rose at nearly the same rate as the lake--typically about 0.5 m/d--with a few targets rising slightly faster than the lake. The rate of vertical movement fell off rapidly with distance from the lake: for d = ca. 600 m--roughly twice the local ice thickness--targets moved upward only about 10% as fast as lake stage. Vertical movement of targets with d > ca. 1 km seemed to be uncorrelated with lake stage. The general pattern is consistent with the idea that a wedge of water extended beneath the glacier to a distance of perhaps 300 to 400 m from the visible margin of the lake and exerts buoyant stresses on the ice that were transmitted into the main body of the glacier and caused flexure. This scenario bears some resemblance to tidal deflections of ice shelves or tidewater glaciers. For a given value of lake stage, target elevations were invariably higher as the lake drained than as the lake filled. Moreover, survey targets at a distance of about 400 m or more from the lake continued to rise for some time even after the lake began to drain. The lag time between the beginning of lake drainage and the beginning of target downdrop increased with distance from the lake, with the lag being about 14 hours at a distance of 400 m from the lake. (The lake drained completely in approximately 75 hours.) The likeliest explanations for the departure from reversibility and the existence of the time lag are either (i) a "viscous" response of the glacier to the flexural stresses imposed by the subglacial water wedge, or (ii) movement of water from the lake into temporary storage--a sort of hydraulic jacking. We favor the latter explanation and suggest that as the lake drained, water "backed up" from a main drainage channel into a basal cavity system and perhaps englacial voids as well; the stored water then drained back out as pressure eventually fell in the main channel. Assuming that all the vertical downdrop of the ice is due to the evacuation of water, the total volume of the putative subglacial "wedge" plus the water released from distributed storage is about 7 to 11 million cubic meters, or about 25 to 40% of the volume of the subaerial lake.
NASA Astrophysics Data System (ADS)
Wang, Miao; Wang, Jin; Wang, Jiajin; Shi, Cheng
2018-02-01
A three-dimensional (3D) numerical model is established and validated for cooling performance optimization between a high-level water collecting natural draft wet cooling tower (HNDWCT) and a usual natural draft wet cooling tower (UNDWCT) under the actual operation condition at Wanzhou power plant, Chongqing, China. User defined functions (UDFs) of source terms are composed and loaded into the spray, fill and rain zones. Considering the conditions of impact on three kinds of corrugated fills (Double-oblique wave, Two-way wave and S wave) and four kinds of fill height (1.25 m, 1.5 m, 1.75 m and 2 m), numerical simulation of cooling performance are analysed. The results demonstrate that the S wave has the highest cooling efficiency in three fills for both towers, indicating that fill characteristics are crucial to cooling performance. Moreover, the cooling performance of the HNDWCT is far superior to that of the UNDWCT with fill height increases of 1.75 m and above, because the air mass flow rate in the fill zone of the HNDWCT improves more than that in the UNDWCT, as a result of the rain zone resistance declining sharply for the HNDWCT. In addition, the mass and heat transfer capacity of the HNDWCT is better in the tower centre zone than in the outer zone near the tower wall under a uniform fill layout. This behaviour is inverted for the UNDWCT, perhaps because the high-level collection devices play the role of flow guiding in the inner zone. Therefore, when non-uniform fill layout optimization is applied to the HNDWCT, the inner zone increases in height from 1.75 m to 2 m, the outer zone reduces in height from 1.75 m to 1.5 m, and the outlet water temperature declines approximately 0.4 K compared to that of the uniform layout.
The Berry phase and the phase of the determinant
DOE Office of Scientific and Technical Information (OSTI.GOV)
Braverman, Maxim
2014-04-15
We show that under very general assumptions the adiabatic approximation of the phase of the zeta-regularized determinant of the imaginary-time Schrödinger operator with periodic Hamiltonian is equal to the Berry phase.
On approximate formulas for the electrostatic force between two conducting spheres
NASA Astrophysics Data System (ADS)
Sliško, Josip; Brito-Orta, Raúl A.
1998-04-01
A series expression for the electrostatic force between two charged conducting spheres having equal radii and charges is derived using the method of electrical images. This expression is a special case of that for two spheres with arbitrary charges and radii, found by Maxwell using zonal harmonics. Keeping in mind the use of approximate formulas for the interpretation of classroom measurements of the electrostatic force between spheres, we comment on two incorrect approximate formulas and examine the contribution of the first few non-Coulomb terms of the correct formula by comparing with values obtained using a computational approach.
Nuclear spin relaxation in Au/sup 51/V: spin dynamics of a Kondo alloy
DOE Office of Scientific and Technical Information (OSTI.GOV)
Narath, A.; Follstaedt, D.
1977-01-01
The temperature dependent spin dynamics of vanadium impurities in the Kondo alloy AuV (theta/sub K/ approximately equal to 300K) have been studied by means of measurements of /sup 51/V transverse relaxation rates (T/sub 2//sup -1/) for the temperature range 1 to 260 K and vanadium concentrations of 0.2 and 0.5 at.%. Contrary to published reports, we find the quantity T/sub 2/T to increase markedly with increasing temperature. Its magnitude at 260 K (15(+-5) msec-K) exceeds the limiting low-temperature value by a factor of 10. The observed increase in T/sub 2/T indicates a large reduction in the impurity spin-correlation time, e.g.,more » tau/sub e/(theta/sub K/)/tau/sub e/(0) approximately equal to 0.2.« less
Plasma entry into the earth's magnetosphere
NASA Technical Reports Server (NTRS)
Frank, L. A.
1972-01-01
Both high- and low-altitude measurements are used to establish the salient features of the three regions presently thought to be the best candidates for the entry of magnetosheath plasma into the magnetosphere, and hence the primal sources of charged particles for the plasma sheet and its earthward termination in the ring current. These three regions are (1) the polar cusps and their extensions into the nighttime magnetosphere, (2) the downstream flanks of the magnetosphere at geocentric radial distances approximately equal to 10 to 50 earth radii along the plasma sheet-magnetosheath interface, and (3) the distant magnetotail at radial distances greater than or approximately equal to 50 earth radii. Present observational knowledge of each of these regions is discussed critically as to evidences for charged particle entry into the magnetosphere from the magnetosheath. The possibility that all three of these magnetospheric domains share an intimate topological relationship is also examined.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jarząbek, D. M., E-mail: djarz@ippt.pan.pl
2015-01-15
A direct method for the evaluation of the torsional spring constants of the atomic force microscope cantilevers is presented in this paper. The method uses a nanoindenter to apply forces at the long axis of the cantilever and in the certain distance from it. The torque vs torsion relation is then evaluated by the comparison of the results of the indentations experiments at different positions on the cantilever. Next, this relation is used for the precise determination of the torsional spring constant of the cantilever. The statistical analysis shows that the standard deviation of the calibration measurements is equal tomore » approximately 1%. Furthermore, a simple method for calibration of the photodetector’s lateral response is proposed. The overall procedure of the lateral calibration constant determination has the accuracy approximately equal to 10%.« less
Microwave fixation versus formalin fixation of surgical and autopsy tissue.
Login, G R
1978-05-01
Microwave irradiation of surgical and autopsy tissue penetrates, fixes, and hardens the tissue almost immediately (the fluid media used in the microwave consisted of saline, ten percent phosphate buffered formalin, and distilled water). Tissue sections from a representative sample of organs were tested. Comparable sections were simultaneously fixed in a phosphate buffered ten percent formalin bath in a vaccum oven as a control. Hematoxylin and eosin were used to stain the sections. Results equal to and superior to the control method were obtained. Saline microwave fixation was superior to formalin microwave fixation. Tissues placed in Zenker's solution and fixed in standard microwave oven (for approximately one minute) yielded results at least equal to conventional Zenker fixation (approximately two hours). No tissue hardening resulted from Zenker microwave fixation. A unique time versus temperature graph (microwave heating curve) reduces individual variation with this technique.
NASA Technical Reports Server (NTRS)
Schwerdt, Helen N.; Chae, Junseok; Miranda, Felix A.
2012-01-01
This paper reports the wireless performance of a biocompatible fully passive microsystem implanted in phantom media simulating the dispersive dielectric properties of the human head, for potential application in recording cortical neuropotentials. Fully passive wireless operation is achieved by means of backscattering electromagnetic (EM) waves carrying 3rd order harmonic mixing products (2f(sub 0) plus or minus f(sub m)=4.4-4.9 GHZ) containing targeted neuropotential signals (fm approximately equal to 1-1000 Hz). The microsystem is enclosed in 4 micrometer thick parylene-C for biocompatibility and has a footprint of 4 millimeters x 12 millimeters x 500 micrometers. Preliminary testing of the microsystem implanted in the lossy biological simulating media results in signal-to-noise ratio's (SNR) near 22 (SNR approximately equal to 38 in free space) for millivolt level neuropotentials, demonstrating the potential for fully passive wireless microsystems in implantable medical applications.
Baur, Alexander Daniel Jacques; Kunz, Florian; Schwenke, Carsten; Pschowski, René; Röpke, Torsten Kai; Pavel, Marianne; Denecke, Timm
2016-01-01
The aim of this study was to evaluate signs of right-sided heart dysfunction on staging computed tomography (CT) as indirect indicators of carcinoid heart disease. Patients with functionally active neuroendocrine neoplasm and different grades of tricuspid valve regurgitation (TR) were identified. Two readers independently reviewed contrast-enhanced staging CT performed within 90 days before or after echocardiography. Logistic regression and receiver operating analyses were used to asses the predictive value of right ventricle-left ventricle ratio (RV-LV ratio), ventricular septal bowing, retrograde contrast filling of the hepatic veins during contrast injection, and time to aortal enhancement greater than 100 Hounsfield units during bolus tracking for TR. Forty-four examinations were evaluated (11 with TR = 0, 16 with TR = 1, 9 with TR = 2, and 8 with TR = 3). Right ventricle-LV ratio was found to predict TR less than or equal to 1 versus TR greater than 1 (P = 0.0188) and TR less than or equal to 1 versus TR equals 2 (P = 0.0082). A prolonged time to aortal enhancement greater than 100 Hounsfield units during bolus tracking predicted TR less than or equal to 1 versus TR greater than 1 (P = 0.0077). Area under the curve for RV-LV ratio was 0.86 when differentiating TR less than or equal to 1 versus TR equals 2. With a cutoff of 1.07, sensitivity was 0.89, and specificity was 0.72. In patients with functionally active neuroendocrine neoplasm, an RV-LV ratio of more than 1.07 predicted TR with a relatively high sensitivity and moderate specificity and thus could serve as an indicator of subclinical carcinoid heart disease on routine staging CT.
Convection in an ideal gas at high Rayleigh numbers.
Tilgner, A
2011-08-01
Numerical simulations of convection in a layer filled with ideal gas are presented. The control parameters are chosen such that there is a significant variation of density of the gas in going from the bottom to the top of the layer. The relations between the Rayleigh, Peclet, and Nusselt numbers depend on the density stratification. It is proposed to use a data reduction which accounts for the variable density by introducing into the scaling laws an effective density. The relevant density is the geometric mean of the maximum and minimum densities in the layer. A good fit to the data is then obtained with power laws with the same exponent as for fluids in the Boussinesq limit. Two relations connect the top and bottom boundary layers: The kinetic energy densities computed from free fall velocities are equal at the top and bottom, and the products of free fall velocities and maximum horizontal velocities are equal for both boundaries.
How to Fill Your Toy Shelves Without Emptying Your Pocketbook: 70 Inexpensive Things to Do or Make.
ERIC Educational Resources Information Center
Southwest Educational Development Lab., Austin, TX.
Designed for parents and teachers, the manual contains suggestions for approximately 70 inexpensively constructed games, activities, and manipulative materials for use with handicapped and non handicapped young children. Suggested are procedures for conducting materials workshops for parents and teachers. Instructions are provided for items…
Federal Register 2010, 2011, 2012, 2013, 2014
2011-05-25
... involvement associated with the proposed action is the discharge or dredged or fill material into waters of... affect navigable waters. Federal authorizations for the proposed project would constitute a ``major... sedimentation settling basin. c. An approximate 20-acre sedimentation settling and storage basin. d. An...
2013-03-01
training aircraft in the USAF inventory has steadily decreased over time from approximately 2,700 in the 1970s, to 1,800 in the 1980s , and finally to...Ibid., 93 34 Ibid., 97 35 Ibid., 84 28 36 Kenneth T. Hislop , QF-16 Program Manager, Eglin AFB, FL, e-mail message to author, January 17, 2013
Spectral weight of excitations in Bose Hubbard model
NASA Astrophysics Data System (ADS)
Alavani, Bhargav K.; Pai, Ramesh V.
2017-05-01
We obtain excitation spectra in the superfluid and the Mott Insulator phases of Bose Hubbard model near unit filling within Random Phase Approximation (RPA) and calculate its spectral weight. This gives a transparent description of contribution of each excitation towards the total Density of States (DOS) which we calculate from these spectral weights.
Federal Register 2010, 2011, 2012, 2013, 2014
2011-10-07
... reservoir, termed ``South,'' ``Tejon,'' ``Horsethief,'' and ``Sawmill.'' Water for the initial fill of each of the alternatives would be obtained from local water agency infrastructure via a route that would...) reversible pump turbines and located 900 feet below ground level, approximately midway between the upper and...
Approximate Value of Buoyant Force: A Water-Filled Balloon Demonstration
ERIC Educational Resources Information Center
Radovanovic, Jelena; Slisko, Josip
2012-01-01
Floating and sinking might be common phenomena, encountered on a daily basis, but still represent conceptually complex scientific topics. Research has shown that most students have certain experiences and their own "theories" that explain why objects sink or float. Unfortunately, many of these "theories" are either misconceptions or are valid only…
NASA Astrophysics Data System (ADS)
Pan, Xiao-Min; Wei, Jian-Gong; Peng, Zhen; Sheng, Xin-Qing
2012-02-01
The interpolative decomposition (ID) is combined with the multilevel fast multipole algorithm (MLFMA), denoted by ID-MLFMA, to handle multiscale problems. The ID-MLFMA first generates ID levels by recursively dividing the boxes at the finest MLFMA level into smaller boxes. It is specifically shown that near-field interactions with respect to the MLFMA, in the form of the matrix vector multiplication (MVM), are efficiently approximated at the ID levels. Meanwhile, computations on far-field interactions at the MLFMA levels remain unchanged. Only a small portion of matrix entries are required to approximate coupling among well-separated boxes at the ID levels, and these submatrices can be filled without computing the complete original coupling matrix. It follows that the matrix filling in the ID-MLFMA becomes much less expensive. The memory consumed is thus greatly reduced and the MVM is accelerated as well. Several factors that may influence the accuracy, efficiency and reliability of the proposed ID-MLFMA are investigated by numerical experiments. Complex targets are calculated to demonstrate the capability of the ID-MLFMA algorithm.
Jeaidi, Zaid Al
2016-01-01
To assess the fracture resistance of endodontically treated teeth with a novel Zirconia (Zr) nano-particle filler containing bulk fill resin composite. Forty-five freshly extracted maxillary central incisors were endodontically treated using conventional step back preparation and warm lateral condensation filling. Post space preparation was performed using drills compatible for fiber posts (Rely X Fiber Post) on all teeth (n=45), and posts were cemented using self etch resin cement (Rely X Unicem). Samples were equally divided into three groups (n=15) based on the type of core materials, ZirconCore (ZC) MulticCore Flow (MC) and Luxacore Dual (LC). All specimens were mounted in acrylic resin and loads were applied (Universal testing machine) at 130° to the long axis of teeth, at a crosshead speed of 0.5 mm/min until failure. The loads and the site at which the failures occurred were recorded. Data obtained was tabulated and analyzed using a statistical program. The means and standard deviations were compared using ANOVA and Multiple comparisons test. The lowest and highest failure loads were shown by groups LC (18.741±3.02) and MC (25.16±3.30) respectively. Group LC (18.741±3.02) showed significantly lower failure loads compared to groups ZC (23.02±4.21) and MC (25.16±3.30) (p<0.01). However groups ZC (23.02±4.21) and MC (25.16±3.30) showed comparable failure loads (p=0.23). Fracture resistance of endodontically treated teeth restored with Zr filler containing bulk fill composite cores was comparable to teeth restored with conventional Zr free bulk fill composites. Zr filled bulk fill composites are recommended for restoration of endodontically treated teeth as they show comparable fracture resistance to conventional composite materials with less catastrophic failures.
Reliability of cystometrically obtained intravesical pressures in patients with neurogenic bladders.
Hess, Marika J; Lim, Lance; Yalla, Subbarao V
2002-01-01
Urodynamic studies in patients with neurogenic bladder detect and categorize neurourodynamic states, identify the risk for urologic sequelae, and determine the necessity for interventions. Because urodynamic studies serves as a prognostic indicator and guides patient management, pressure measurements during the study must accurately represent bladder function under physiologic conditions. Because nonphysiologic bladder filling used during conventional urodynamic studies may alter the bladder's accommodative properties, we studied how closely the intravesical pressures obtained before filling cystometry resembled those obtained during the filling phase of the cystometrogram. Twenty-two patients (21 men, 1 woman) with neurogenic bladders underwent standard urodynamic studies. A 16F triple-lumen catheter was inserted into the bladder, and the intravesical pressures were recorded (physiologic volume-specific pressures, PVSP). After emptying the bladder, an equal volume of normal saline solution was reinfused, and the pressures were recorded again (cystometric volume-specific pressure, CVSP). All patients underwent routine fluoroscopically assisted urodynamic testing. The PVSP and the CVSP were compared using the Wilcoxon signed ranks test. P value of .05 was significant. The mean PVSP was 14.5 cmH2O (range, 4-42 cmH2O) and mean CVSP was 20.6 cmH2O (range, 6-70 cmH2O). The CVSP was significantly higher than the PVSP (P = .01). Filling pressures during cystometry (CVSP) were significantly higher than the pressures measured at rest (PVSP). This study also suggests a strong correlation between PVSP and CVSP.
NASA Astrophysics Data System (ADS)
Wakefield, Oliver J. W.; Mountney, Nigel P.
2013-12-01
The Pennsylvanian to Permian lower Cutler beds collectively form the lowermost stratigraphic unit of the Cutler Group in the Paradox Basin, southeast Utah. The lower Cutler beds represent a tripartite succession comprising lithofacies assemblages of aeolian, fluvial and shallow-marine origin, in near equal proportion. The succession results from a series of transgressive-regressive cycles, driven by repeated episodes of climatic variation and linked changes in relative sea-level. Relative sea-level changes created a number of incised-valleys, each forming through fluvial incision during lowered base-level. Aeolian dominance during periods of relative sea-level lowstand aids incised-valley identification as the erosive bounding surface juxtaposes incised-valley infill against stacked aeolian faces. Relative sea-level rises resulted in back-flooding of the incised-valleys and their infill via shallow-marine and estuarine processes. Back-flooded valleys generated marine embayments within which additional local accommodation was exploited. Back-filling is characterised by a distinctive suite of lithofacies arranged into a lowermost, basal fill of fluvial channel and floodplain architectural elements, passing upwards into barform elements with indicators of tidal influence, including inclined heterolithic strata and reactivation surfaces. The incised-valley fills are capped by laterally extensive and continuous marine limestone elements that record the drowning of the valleys and, ultimately, flooding and accumulation across surrounding interfluves (transgressive surface). Limestone elements are characterised by an open-marine fauna and represent the preserved expression of maximum transgression.
Rupert, Michael G.; Plummer, Niel
2009-01-01
This vector data set delineates the approximate boundary of the Eagle River watershed valley-fill aquifer (ERWVFA). This data set was developed by a cooperative project between the U.S. Geological Survey, Eagle County, the Eagle River Water and Sanitation District, the Town of Eagle, the Town of Gypsum, and the Upper Eagle Regional Water Authority. This project was designed to evaluate potential land-development effects on groundwater and surface-water resources so that informed land-use and water management decisions can be made. The boundary of the ERWVFA was developed by combining information from two data sources. The first data source was a 1:250,000-scale geologic map of the Leadville quadrangle developed by Day and others (1999). The location of Quaternary sediments was used as a first approximation of the ERWVFA. The boundary of the ERWVFA was further refined by overlaying the geologic map with Digital Raster Graphic (DRG) scanned images of 1:24,000 topographic maps (U.S. Geological Survey, 2001). Where appropriate, the boundary of the ERWVFA was remapped to correspond with the edge of the valley-fill aquifer marked by an abrupt change in topography at the edge of the valley floor throughout the Eagle River watershed. The boundary of the ERWVFA more closely resembles a hydrogeomorphic region presented by Rupert (2003, p. 8) because it is based upon general geographic extents of geologic materials and not on an actual aquifer location as would be determined through a rigorous hydrogeologic investigation.
ASCA Observations of the T Tauri Star SU Aurigae and the Surrounding L1517 Dark Cloud
NASA Technical Reports Server (NTRS)
Skinner, Stephen L.; Walter, Frederick M.
1998-01-01
We present the results of a approximately equals 40 ks pointed Advanced Satellite for Cosmology and Astrophysics (ASCA) observation of the L1517 star-forming region, centered on the X-ray-bright T Tauri star SU Aurigae. This star has the highest X-ray luminosity of any classical T Tauri star in the Taurus-Auriga region, and its optical spectra show evidence for both mass inflow and outflow. Strong X-ray emission was detected from SU Aur (L(sub x) = 10(exp 30.9) ergs s(exp -1)) as well as weaker emission from five other pre-main-sequence stars. Although no large-amplitude flares were detected, the X-ray emission of SU Aur showed clear variability in the form of a slow decline in count rate during the 1.3 day observation. We provide the first direct comparison of the coronal differential emission measure (DEM) distribution of a classical T Tauri star with that of a young main-sequence star of similar spectral type. The DEM distributions of SU Aur (G2; age 3 Myr) and the young solar-like star EK Draconis (GO V; age 70 Myr) are qualitatively similar, with both showing a bimodal temperature distribution characterized by a cool plasma component peaking at approximately 8-9 MK and a hot component peaking at approximately 20-21 MK. However, there is a striking difference in the relative proportion of plasma at high temperatures in the two stars, with hot plasma (>20 MK) accounting for approximately equals 80% of the volume emission measure of SU Aur, compared to only approximately equals 40% in EK Dra. These results provide new insight into the changes that will occur in the corona of a T Tauri star as it descends onto the main sequence. A sharp decline in the fraction of coronal plasma at flarelike temperatures will occur during the late-T Tauri and post-T Tauri phases, and other recent X-ray studies have shown that this decline will continue after the young solar-like star reaches the main sequence.
The radio emission from the ultraluminous far-infrared galaxy NGC 6240
NASA Technical Reports Server (NTRS)
Colbert, Edward J. M.; Wilson, Andrew S.; Bland-Hawthorn, Jonathan
1994-01-01
We present new radio observations of the 'prototypical' ultraluminous far-infrared galaxy NGC 6240, obtained using the Very Large Array (VLA) at lambda = 20 cm in B-configuration and at lambda = 3.6 cm in A-configuration. These data, along with those from four previous VLA observations, are used to perform a comprehensive study of the radio emission from NGC 6240. Approximately 70% (approximately 3 x 10(exp 23) W/Hz) of the total radio power at 20 cm originates from the nuclear region (approximately less than 1.5 kpc), of which half is emitted by two unresolved (R approximately less than 36 pc) cores and half by a diffuse component. The radio spectrum of the nuclear emission is relatively flat (alpha approximately equals 0.6; S(sub nu) proportional to nu(exp -alpha). The supernova rate required to power the diffuse component is consistent with that predicted by the stellar evolution models of Rieke et al. (1985). If the radio emission from the two compact cores is powered by supernova remnants, then either the remnants overlap and form hot bubbles in the cores, or they are very young (approximately less than 100 yr.) Nearly all of the remaining 30% of the total radio power comes from an 'armlike' region extending westward from the nuclear region. The western arm emission has a steep spectrum (alpha approximately equals 1.0), suggestive of aging effects from synchrotron or inverse-Compton losses, and is not correlated with starlight; we suggest that it is synchrotron emission from a shell of material driven by a galactic superwind. Inverse Compton scattering of far-infrared photons in the radio sources is expected to produce an X-ray flux of approximately 2 - 6 x 10(exp -14) ergs/s/sq cm in the 2 - 10 keV band. No significant radio emission is detected from or near the possible ultramassive 'dark core'.
NASA Astrophysics Data System (ADS)
Ciz, Radim; Saenger, Erik H.; Gurevich, Boris; Shapiro, Serge A.
2009-03-01
We develop a new model for elastic properties of rocks saturated with heavy oil. The heavy oil is represented by a viscoelastic material, which at low frequencies and/or high temperatures behaves as a Newtonian fluid, and at high frequencies and/or low temperatures as a nearly elastic solid. The bulk and shear moduli of a porous rock saturated with such viscoelastic material are then computed using approximate extended Gassmann equations of Ciz and Shapiro by replacing the elastic moduli of the pore filling material with complex and frequency-dependent moduli of the viscoelastic pore fill. We test the proposed model by comparing its predictions with numerical simulations based on a direct finite-difference solution of equations of dynamic viscoelasticity. The simulations are performed for the reflection coefficient from an interface between a homogeneous fluid and a porous medium. The numerical tests are performed both for an idealized porous medium consisting of alternating solid and viscoelastic layers, and for a more realistic 3-D geometry of the pore space. Both sets of numerical tests show a good agreement between the predictions of the proposed viscoelastic workflow and numerical simulations for relatively high viscosities where viscoelastic effects are important. The results confirm that application of extended Gassmann equations in conjunction with the complex and frequency-dependent moduli of viscoelastic pore filling material, such as heavy oil, provides a good approximation for the elastic moduli of rocks saturated with such material. By construction, this approximation is exactly consistent with the classical Gassmann's equation for sufficiently low frequencies or high temperature when heavy oil behaves like a fluid. For higher frequencies and/or lower temperatures, the predictions are in good agreement with the direct numerical solution of equations of dynamic viscoelasticity on the microscale. This demonstrates that the proposed methodology provides realistic estimates of elastic properties of heavy oil rocks.
Al-khwarizmi: a new-found basin on the lunar far side.
El-Baz, F
1973-06-15
Apollo 16 and Apollo 17 photographs of the far side of the moon reveal a double-ringed basin 500 kilometers in diameter centered at 1 degrees N, 112 degrees E. The structure is very old and subdued; it is probably Pre-Nectarian in age and appears to have been filled and modified by younger events. The heights of the basin's rings are based on laser altimeter data from Apollo missions 15 through 17; these data suggest a third outer ring, approximately 1000 kilometers in diameter. Laser measurements also indicate that the filled basin separates the relatively low terrain on the eastern limb of the moon from the higher, more rugged highlands to the east.
Characterization of Adhesives for Attaching Reusable Surface Insulation on Space Shuttle Vehicles
NASA Technical Reports Server (NTRS)
Owen, H. P.; Carroll, M. T.
1973-01-01
An extensive development and testing program on adhesive systems shows that: (1) A closed cell silicone rubber sponge bonded to substrates with thin bond lines of glass filled adhesive exhibits density and modulus values approximately one third that of solid silicone adhesives; (2) utilization of glass or phenolic microballoons as fillers in silicone adhesives reduces density but increases moduli of the vulcanized materials; (3) the silicone elastomer based adhesives appear to be complex systems rather than homogeneous, isotropic materials. Tensile, shear, and compression properties plotted versus temperature verify this conjecture; and (4) constant strain-stress relaxation tests on glass-filled adhesive show that stress relaxation is most pronounced near the glass transition temperature.
NASA Technical Reports Server (NTRS)
2004-01-01
9 September 2004 Northeastern Arabia Terra is a heavily eroded portion of the martian cratered highlands. Layered rock, containing filled and buried valleys and ancient impact craters, has been eroded such that these once-buried features are now partially exposed at the martian surface. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows an example of a field of circular and somewhat circular features that once were impact craters that were subsequently filled, buried, then exhumed to form the patterns exhibited here. The image is located near 25.6oN, 290.2oW. The image covers an area approximately 3 km (1.9 mi) across and is illuminated by sunlight from the lower left.A rack is installed in MPLM Leonardo
NASA Technical Reports Server (NTRS)
2000-01-01
Workers (right, left and center) in the Space Station Processing Facility wait to install a laboratory rack in the Multi-Purpose Logistics Module Leonardo (background). Leonardo is the first of three such pressurized modules that will serve as the International Space Station's '''moving vans,''' carrying laboratory racks filled with equipment, experiments and supplies to and from the Space Station aboard the Space Shuttle. Approximately 21 feet long and 15 feet in diameter, Leonardo will be launched on Shuttle mission STS-102 March 1, 2001. On that flight, Leonardo will be filled with equipment and supplies to outfit the U.S. laboratory module, being carried to the ISS on the Jan. 19, 2001, launch of STS-98.
A rack is installed in MPLM Leonardo
NASA Technical Reports Server (NTRS)
2000-01-01
In the Space Station Processing Facility, the Multi-Purpose Logistics Module Leonardo (right) is ready for installation of a laboratory rack (left center). Leonardo is the first of three such pressurized modules that will serve as the International Space Station's '''moving vans,''' carrying laboratory racks filled with equipment, experiments and supplies to and from the Space Station aboard the Space Shuttle. Approximately 21 feet long and 15 feet in diameter, Leonardo will be launched on Shuttle mission STS-102 March 1, 2001. On that flight, Leonardo will be filled with equipment and supplies to outfit the U.S. laboratory module, being carried to the ISS on the Jan. 19, 2001, launch of STS-98.
NASA Technical Reports Server (NTRS)
Pani, Shantanu Kumar; Wang, Sheng-Hsiang; Lin, Neng-Huei; Lee, Chung-Te; Tsay, Si-Chee; Holben, Brent N.; Janjai, Serm; Hsiao, Ta-Chih; Chuang, Ming-Tung; Chantara, Somporn
2016-01-01
The direct aerosol radiative effects of biomass-burning (BB) aerosols over northern Indochina were estimated by using aerosol properties (physical, chemical, and optical) along with the vertical profile measurements from ground-based measurements with integration of an optical and a radiative transfer model during the Seven South East Asian Studies Biomass-Burning Aerosols Stratocumulus Environment: Lifecycles Interactions Experiment (7-SEASBASELInE) conducted in spring 2013. Cluster analysis of backward trajectories showed the air masses arriving at mountainous background site (Doi Ang Khang; 19.93degN, 99.05degE, 1536 m above mean sea level) in northern Indochina, mainly from near-source inland BB activities and being confined in the planetary boundary layer. The PM(sub10) and black carbon (BC)mass were 87 +/- 28 and 7 +/- 2 micrograms m(exp -3), respectively. The aerosol optical depth (AOD (sub 500) was found to be 0.26--1.13 (0.71 +/- 0.24). Finer (fine mode fraction is approximately or equal to 0.95, angstrom-exponent at 440-870 nm is approximately or equal to 1.77) and significantly absorbing aerosols(single scattering albedo is approximately or equal to 0.89, asymmetry-parameter is approximately or equal to 0.67, and absorption AOD 0.1 at 440 nm) dominated over this region. BB aerosols (water soluble and BC) were the main contributor to the aerosol radiative forcing (ARF), while others (water insoluble, sea salt and mineral dust) were negligible mainly due to their low extinction efficiency. BC contributed only 6 to the surface aerosol mass but its contribution to AOD was 12 (2 times higher). The overall mean ARF was 8.0 and -31.4 W m(exp -2) at top-of-atmosphere (TOA) and at the surface (SFC), respectively. Likely, ARF due to BC was +10.7 and -18.1 W m(exp -2) at TOA and SFC, respectively. BC imposed the heating rate of +1.4 K d(exp -1) within the atmosphere and highlighting its pivotal role in modifying the radiation budget. We propose that to upgrade our knowledge on BB aerosol radiative effects in BB source region, the long-term and extensive field measurements are needed.
Paterson, Janis E; Gao, Wanzhen; Sundborn, Gerhard; Cartwright, Susan
2011-02-01
To examine maternal and socio-demographic factors associated with oral health practices and experiences in six-year-old Pacific children. The longitudinal Pacific Islands Families (PIF) study is following a cohort of Pacific children born in Auckland, New Zealand in 2000. At approximately six years postpartum maternal reports (n = 1001) on child oral health practices and experiences of fillings and extractions were gathered. Forty-five per cent of mothers reported that their child had experienced fillings or extractions. After adjusting for confounding factors, we found that Tongan children were almost twice as likely to have their teeth filled or extracted than Samoan children (OR, 1.93; 95%, 1.34-2.77). Differences between Samoan children and children of other ethnic groups were not significant. Children of mothers who had secondary qualifications were significantly less likely to have their teeth filled or extracted compared to children of mothers who had postsecondary qualifications (OR, 0.634; 95%, 0.44-0.90). Prolonged duration of breastfeeding was associated with an increased likelihood of filling or extraction experience. In terms of maternal oral hygiene, maternal tooth brushing frequency of less that once a day was significantly associated with increased odds of fillings and/or extractions in their children (OR, 1.35; 95% CI, 1.02-1.79). Children who were sometimes supervised for tooth brushing were significantly more likely to have fillings or extractions than children who were not provided supervision. These findings highlight the role of cultural factors and maternal hygiene in child oral health outcomes and suggest that health promotion efforts should encompass the whole family and embrace a culturally appropriate approach. © 2010 John Wiley & Sons A/S.
Maghaireh, G A; Price, R B; Abdo, N; Taha, N A; Alzraikat, H
2018-06-28
This study compared light transmission through different thicknesses of bulk-fill resin-based composites (RBCs) using a polywave and a single-peak light-emitting diode light-curing unit (LCU). The effect on the surface hardness was also evaluated. Five bulk-fill RBCs were tested. Specimens (n=5) of 1-, 2-, 4-, or 6-mm thickness were photopolymerized for 10 seconds from the top using a polywave (Bluephase Style) or single-peak (Elipar S10) LCU, while a spectrophotometer monitored in real time the transmitted irradiance and radiant exposure reaching the bottom of the specimen. After 24 hours of storage in distilled water at 37°C, the Vickers microhardness (VH) was measured at top and bottom. Results were analyzed using multiple-way analysis of variance, Tukey post hoc tests, and multivariate analysis (α=0.05). The choice of LCU had no significant effect on the total amount of light transmitted through the five bulk-fill RBCs at each thickness. There was a significant decrease in the amount of light transmitted as the thickness increased for all RBCs tested with both LCUs ( p<0.001). Effect of LCU on VH was minimal (η p 2 =0.010). The 1-, 2-, and 4-mm-thick specimens of SDR, X-tra Fill, and Filtek Bulk Restorative achieved a VH bottom/top ratio of approximately 80% when either LCU was used. The total amount of light transmitted through the five bulk-fill RBCs was similar at the different thicknesses using either LCU. The polywave LCU used in this study did not enhance the polymerization of the tested bulk-fill RBCs when compared with the single-peak LCU.
HST images of very compact blue galaxies at z approximately 0.2
NASA Technical Reports Server (NTRS)
Koo, David C.; Bershady, Matthew A.; Wirth, Gregory D.; Stanford, S. Adam; Majewski, Steven R.
1994-01-01
We present the results of Hubble Space Telescope (HST) Wide-Field Camera (WFC) imaging of seven very compact, very blue galaxies with B less than or equal to 21 and redshifts z approximately 0.1 to 0.35. Based on deconvolved images, we estimate typical half-light diameters of approximately 0.65 sec, corresponding to approximately 1.4 h(exp -1) kpc at redshifts z approximately 0.2. The average rest frame surface brightness within this diameter is mu(sub v) approximately 20.5 mag arcsec(exp -2), approximately 1 mag brighter than that of typical late-type blue galaxies. Ground-based spectra show strong, narrow emission lines indicating high ionization; their very blue colors suggest recent bursts of star-formation; their typical luminosities are approximately 4 times fainter than that of field galaxies. These characteristics suggest H II galaxies as likely local counterparts of our sample, though our most luminous targets appear to be unusually compact for their luminosities.
Approximate Genealogies Under Genetic Hitchhiking
Pfaffelhuber, P.; Haubold, B.; Wakolbinger, A.
2006-01-01
The rapid fixation of an advantageous allele leads to a reduction in linked neutral variation around the target of selection. The genealogy at a neutral locus in such a selective sweep can be simulated by first generating a random path of the advantageous allele's frequency and then a structured coalescent in this background. Usually the frequency path is approximated by a logistic growth curve. We discuss an alternative method that approximates the genealogy by a random binary splitting tree, a so-called Yule tree that does not require first constructing a frequency path. Compared to the coalescent in a logistic background, this method gives a slightly better approximation for identity by descent during the selective phase and a much better approximation for the number of lineages that stem from the founder of the selective sweep. In applications such as the approximation of the distribution of Tajima's D, the two approximation methods perform equally well. For relevant parameter ranges, the Yule approximation is faster. PMID:17182733
Binary Black Hole Late Inspiral: Simulations for Gravitational Wave Observations
NASA Technical Reports Server (NTRS)
Baker, John G.; vanMeter, James R.; Centrella, Joan; Choi, Dae-Il; Kelly, Bernard J.; Koppitz, Michael
2006-01-01
Coalescing binary black hole mergers are expected to be the strongest gravitational wave sources for ground-based interferometers, such as the LIGO, VIRGO, and GEO600, as well as the spacebased interferometer LISA. Until recently it has been impossible to reliably derive the predictions of General Relativity for the final merger stage, which takes place in the strong-field regime. Recent progress in numerical relativity simulations is, however, revolutionizing our understanding of these systems. We examine here the specific case of merging equal-mass Schwarzschild black holes in detail, presenting new simulations in which the black holes start in the late inspiral stage on orbits with very low eccentricity and evolve for approximately 1200M through approximately 7 orbits before merging. We study the accuracy and consistency of our simulations and the resulting gravitational waveforms, which encompass approximately 14 cycles before merger, and highlight the importance of using frequency (rather than time) to set the physical reference when comparing models. Matching our results to PN calculations for the earlier parts of the inspiral provides a combined waveform with less than half a cycle of accumulated phase error through the entire coalescence. Using this waveform, we calculate signal-to-noise ratios (SNRs) for iLIGO, adLIGO, and LISA, highlighting the contributions from the late-inspiral and merger-ringdown parts of the waveform which can now be simulated numerically. Contour plots of SNR as a function of z and M show that adLIGO can achieve SNR 2 10 for some IMBBHs out to z approximately equals 1, and that LISA can see MBBHs in the range 3 x 10(exp 4) approximately < M/Mo approximately < 10(exp 7) at SNR > 100 out to the earliest epochs of structure formation at z > 15.
Preservative loss from silicone tubing during filling processes.
Saller, Verena; Matilainen, Julia; Rothkopf, Christian; Serafin, Daniel; Bechtold-Peters, Karoline; Mahler, Hanns-Christian; Friess, Wolfgang
2017-03-01
Significant loss of preservative was observed during filling of drug products during filling line stops. This study evaluated the losses of three commonly used preservatives in protein drugs, i.e. benzyl alcohol, phenol, and m-cresol. Concentration losses during static incubation were quantified and interpreted with regard to the potential driving forces for the underlying sorption, diffusion, and desorption steps. Partitioning from the solution into the silicone polymer was identified as the most decisive parameter for the extent of preservative loss. Additionally, the influence of tubing inner diameter, starting concentration as well as silicone tubing type was evaluated. Theoretical calculations assuming equilibrium between solution and tubing inner surface and one-directional diffusion following Fick's first law were used to approximate experimental data. Since significant losses were found already after few minutes, adequate measures must be taken to avoid deviations during filling of preservative-containing protein solutions that may impact product quality or antimicrobial efficacy. As a possible alternative to the highly permeable silicone tubing, a specific make of fluoropolymer tubing was identified being suitable for peristaltic pumps and not showing any preservative losses. Copyright © 2016 Elsevier B.V. All rights reserved.
NASA Technical Reports Server (NTRS)
Lehmer, B. D.; Berkeley, M.; Zezas, A.; Alexander, D. M.; Basu-Zych, A.; Bauer, F. E.; Brandt, W. N.; Fragos, T.; Hornschemeier, A. E.; Kalogera, V.;
2014-01-01
We present direct constraints on how the formation of low-mass X-ray binary (LMXB) populations in galactic fields depends on stellar age. In this pilot study, we utilize Chandra and Hubble Space Telescope (HST) data to detect and characterize the X-ray point source populations of three nearby early-type galaxies: NGC 3115, 3379, and 3384. The luminosity-weighted stellar ages of our sample span approximately equal to 3-10 Gyr. X-ray binary population synthesis models predict that the field LMXBs associated with younger stellar populations should be more numerous and luminous per unit stellar mass than older populations due to the evolution of LMXB donor star masses. Crucially, the combination of deep Chandra and HST observations allows us to test directly this prediction by identifying and removing counterparts to X-ray point sources that are unrelated to the field LMXB populations, including LMXBs that are formed dynamically in globular clusters, Galactic stars, and background AGN/galaxies. We find that the "young" early-type galaxy NGC 3384 (approximately equals 2-5 Gyr) has an excess of luminous field LMXBs (L(sub x) approximately greater than (5-10) × 10(exp 37) erg s(exp -1)) per unit K-band luminosity (L(sub K); a proxy for stellar mass) than the "old" early-type galaxies NGC 3115 and 3379 (approximately equals 8-10 Gyr), which results in a factor of 2-3 excess of L(sub X)/L(sub K) for NGC 3384. This result is consistent with the X-ray binary population synthesis model predictions; however, our small galaxy sample size does not allow us to draw definitive conclusions on the evolution field LMXBs in general. We discuss how future surveys of larger galaxy samples that combine deep Chandra and HST data could provide a powerful new benchmark for calibrating X-ray binary population synthesis models.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Horsten, N., E-mail: niels.horsten@kuleuven.be; Baelmans, M.; Dekeyser, W.
2016-01-15
We derive fluid neutral approximations for a simplified 1D edge plasma model, suitable to study the neutral behavior close to the target of a nuclear fusion divertor, and compare its solutions to the solution of the corresponding kinetic Boltzmann equation. The plasma is considered as a fixed background extracted from a detached 2D simulation. We show that the Maxwellian equilibrium distribution is already obtained very close to the target, justifying the use of a fluid approximation. We compare three fluid neutral models: (i) a diffusion model; (ii) a pressure-diffusion model (i.e., a combination of a continuity and momentum equation) assumingmore » equal neutral and ion temperatures; and (iii) the pressure-diffusion model coupled to a neutral energy equation taking into account temperature differences between neutrals and ions. Partial reflection of neutrals reaching the boundaries is included in both the kinetic and fluid models. We propose two methods to obtain an incident neutral flux boundary condition for the fluid models: one based on a diffusion approximation and the other assuming a truncated Chapman-Enskog distribution. The pressure-diffusion model predicts the plasma sources very well. The diffusion boundary condition gives slightly better results overall. Although including an energy equation still improves the results, the assumption of equal ion and neutral temperature already gives a very good approximation.« less
The imprint of proper motion of nonlinear structures on the cosmic microwave background
NASA Technical Reports Server (NTRS)
Tuluie, Robin; Laguna, Pablo
1995-01-01
We investigate the imprint of nonlinear matter condensations on the cosmic microwave background (CMB) in an Omega = 1, cold dark matter (CDM) model universe. Temperature anisotropies are obtained by numerically evolving matter inhomogeneities and CMB photons from the beginning of decoupling until the present epoch. The underlying density field produced by the inhomogeneities is followed from the linear, through the weakly clustered, into the fully nonlinear regime. We concentrate on CMB temperature distortions arising from variations in the gravitational potentials of nonlinear structures. We find two sources of temperature fluctuations produced by time-varying potentials: (1) anisotropies due to intrinsic changes in the gravitational potentials of the inhomogeneities and (2) anisotropies generated by the peculiar, bulk motion of the structures across the microwave sky. Both effects generate CMB anisotropies in the range of 10(exp -7) approximately less than or equal to (Delta T/T) approximately less than or equal to 10(exp -6) on scales of approximately 1 deg. For isolated structures, anisotropies due to proper motion exhibit a dipole-like signature in the CMB sky that in principle could yield information on the transverse velocity of the structures.
The Age of the Inner Halo Globular Cluster NGC 6652
NASA Technical Reports Server (NTRS)
Chaboyer, Brian; Sarajedini, Ata; Armandroff, Taft E.
2000-01-01
Hubble Space Telescope (HST) (V,I) photometry has been obtained for the inner halo globular cluster NGC 6652. The photometry reaches approximately 4 mag below the turn-off and includes a well populated horizontal branch (HB). This cluster is located close to the Galactic center at RGC approximately equal to 2.0 kpc with a reddening of E(V-I) = 0.15 +/- 0.02 and has a metallicity of [Fe/H] approximately equal to -0.85. Based upon DELTA V (sup SGB) (sub HB), NGC 6652 is 11.7 plus or minus 1.6 Gyr old. Using A HB precise differential ages for 47 Tuc (a thick disk globular), M107 and NGC 1851 (both halo clusters) were obtained. NGC 6652 appears to be the same age as 47 Tuc and NGC 1851 (within +/- 1.2 Gyr), while there is a slight suggestion that M107 is older than NGC 6652 by 2.3 +/- 1.5 Gyr. As this is a less than 2 sigma result, this issue needs to be investigated further before a definitive statement regarding the relative age of M107 and NGC 6652 may be made.
Sculpting a Pre-Planetary Nebula with a Precessing Jet: IRAS 16342-3814
NASA Technical Reports Server (NTRS)
Sahai, R.; Le Mignant, D.; Sanchez Contreras, C.; Campbell, R. D.; Chaffee, F. H.
2005-01-01
We have imaged the bipolar pre-planetary nebula IRAS 16342-3814 with the Keck adaptive optics (AO) system in four near-infrared bands in the 1.6-4.7 (micro)m range. The lobes, which showed smoothly varying brightness distributions in previous optical images taken with the Hubble Space Telescope, have a limb-brightened appearance in the AO images, with a remarkable corkscrew structure inscribed on the lobe walls. A well-collimated, precessing jet with a diameter less than or approximately equal to 100 AU and a precession period less than or approximately equal to 50 yr, interacting with ambient circumstellar material, is most likely responsible for the corkscrew structure and the lobes, as indicated by a detailed comparison of our observations with published numerical simulations. The very red colors of the lobes in the near-infrared, coupled with their visibility at optical wavelengths, require that at least half, but not all, of the light of the central star be trapped by a compact circumstellar dust cloud heated to approximately 600-700 K and reradiated in the infrared. The lobes are thus illuminated both by the infrared light from this dust cloud as well as by the optical light from the central star.
Localization-delocalization transition in a system of quantum kicked rotors.
Creffield, C E; Hur, G; Monteiro, T S
2006-01-20
The quantum dynamics of atoms subjected to pairs of closely spaced delta kicks from optical potentials are shown to be quite different from the well-known paradigm of quantum chaos, the single delta-kick system. We find the unitary matrix has a new oscillating band structure corresponding to a cellular structure of phase space and observe a spectral signature of a localization-delocalization transition from one cell to several. We find that the eigenstates have localization lengths which scale with a fractional power L approximately h(-0.75) and obtain a regime of near-linear spectral variances which approximate the "critical statistics" relation summation2(L) approximately or equal to chi(L) approximately 1/2 (1-nu)L, where nu approximately 0.75 is related to the fractal classical phase-space structure. The origin of the nu approximately 0.75 exponent is analyzed.
NASA Astrophysics Data System (ADS)
Schmitt, D. R.; Welz, M.; Rokosh, C. D.; Pontbriand, M.-C.; Smith, D. G.
2004-05-01
Two-dimensional electric resistivity imaging (ERI) is the most exciting and promising geological tool in geomorphology and stratigraphy since development of ground-penetrating radar. Recent innovations in 2-D ERI provides a non-intrusive mean of efficiently resolving complex shallow subsurface structures under a number of different geological scenarios. In this paper, we test the capacity of ERI to image two large pre-late Wisconsinan-aged valley-fills in central Alberta and north-central Montana. Valley-fills record the history of pre-glacial and glacial sedimentary deposits. These fills are of considerable economical value as groundwater aquifers, aggregate resources (sand and gravel), placers (gold, diamond) and sometime gas reservoirs in Alberta. Although the approximate locations of pre-glacial valley-fills have been mapped, the scarcity of borehole (well log) information and sediment exposures make accurate reconstruction of their stratigraphy and cross-section profiles difficult. When coupled with borehole information, ERI successfully imaged three large pre-glacial valley-fills representing three contrasting geological settings. The Sand Coulee segment of the ancestral Missouri River, which has never been glaciated, is filled by electrically conductive pro-glacial lacustrine deposits over resistive sandstone bedrock. By comparison, the Big Sandy segment of the ancestral Missouri River valley has a complex valley-fill composed of till units interbedded with glaciofluvial gravel and varved clays over conductive shale. The fill is capped by floodplain, paludal and low alluvial fan deposits. The pre-glacial Onoway Valley (the ancestral North Saskatchewan River valley) is filled with thick, resistive fluvial gravel over conductive shale and capped with conductive till. The cross-sectional profile of each surveyed pre-glacial valley exhibits discrete benches (terraces) connected by steep drops, features that are hard to map using only boreholes. Best quality ERI results were obtained along the Sand Coulee and Onoway transects where the contrast between the bedrock and valley-fill was large and the surficial sediment was homogeneous. The effects of decreasing reliability with depth, 3-D anomalies, principles of equivalence and suppression, and surface inhomogeneity on the image quality are discussed.
Defect reduction of high-density full-field patterns in jet and flash imprint lithography
NASA Astrophysics Data System (ADS)
Singh, Lovejeet; Luo, Kang; Ye, Zhengmao; Xu, Frank; Haase, Gaddi; Curran, David; LaBrake, Dwayne; Resnick, Douglas; Sreenivasan, S. V.
2011-04-01
Imprint lithography has been shown to be an effective technique for replication of nano-scale features. Jet and Flash Imprint Lithography (J-FIL) involves the field-by-field deposition and exposure of a low viscosity resist deposited by jetting technology onto the substrate. The patterned mask is lowered into the fluid which then quickly flows into the relief patterns in the mask by capillary action. Following this filling step, the resist is crosslinked under UV radiation, and then the mask is removed leaving a patterned resist on the substrate. Acceptance of imprint lithography for manufacturing will require demonstration that it can attain defect levels commensurate with the defect specifications of high end memory devices. Typical defectivity targets are on the order of 0.10/cm2. This work summarizes the results of defect inspections focusing on two key defect types; random non-fill defects occurring during the resist filling process and repeater defects caused by interactions with particles on the substrate. Non-fill defectivity must always be considered within the context of process throughput. The key limiting throughput step in an imprint process is resist filling time. As a result, it is critical to characterize the filling process by measuring non-fill defectivity as a function of fill time. Repeater defects typically have two main sources; mask defects and particle related defects. Previous studies have indicated that soft particles tend to cause non-repeating defects. Hard particles, on the other hand, can cause either resist plugging or mask damage. In this work, an Imprio 500 twenty wafer per hour (wph) development tool was used to study both defect types. By carefully controlling the volume of inkjetted resist, optimizing the drop pattern and controlling the resist fluid front during spreading, fill times of 1.5 seconds were achieved with non-fill defect levels of approximately 1.2/cm2. Longevity runs were used to study repeater defects and a nickel contamination was identified as the key source of particle induced repeater defects.
Hangai, Yoshihiko; Saito, Masaki; Utsunomiya, Takao; Kitahara, Soichiro; Kuwazuru, Osamu; Yoshikawa, Nobuhiro
2014-01-01
Aluminum foam has received considerable attention in various fields and is expected to be used as an engineering material owing to its high energy absorption properties and light weight. To improve the mechanical properties of aluminum foam, combining it with dense tubes, such as aluminum foam-filled tubes, was considered necessary. In this study, an aluminum foam-filled steel tube, which consisted of ADC12 aluminum foam and a thin-wall steel tube, was successfully fabricated by friction welding. It was shown that a diffusion bonding layer with a thickness of approximately 10 μm was formed, indicating that strong bonding between the aluminum foam and the steel tube was realized. By the X-ray computed tomography observation of pore structures, the fabrication of an aluminum foam-filled tube with almost uniform pore structures over the entire specimen was confirmed. In addition, it was confirmed that the aluminum foam-filled steel tube exhibited mechanical properties superior to those of the ADC12 aluminum foam and steel tube. This is considered to be attributed to the combination of the aluminum foam and steel tube, which particularly prevents the brittle fracture and collapse of the ADC12 foam by the steel tube, along with the strong metal bonding between the aluminum foam and the steel tube. PMID:28788213
2012-03-22
location is varied from the aft end of the detonation tube to the middle of the detonation tube while the crossover width is varied from 2.5 in to 0.5...the other end where the tube is connected to a source of fuel, oxidizer, and ignition .7 The engine cycle is divided into three equal phases: fill...location and width of the crossover duct for hydrogen, ethylene and an n-alkane. The crossover location is varied from the aft end of the
Concentration of sunlight to solar-surface levels using non-imaging optics
NASA Astrophysics Data System (ADS)
Gleckman, Philip; O'Gallagher, Joseph; Winston, Roland
1989-05-01
An account is given of the design and operational principles of a solar concentrator that employs nonimaging optics to achieve a solar flux equal to 56,000 times that of ambient sunlight, yielding temperatures comparable to, and with further development of the device, exceeding those of the solar surface. In this scheme, a parabolic mirror primary concentrator is followed by a secondary concentrator, designed according to the edge-ray method, which is filled with a transparent oil. The device may be used in materials-processing, waste-disposal, and solar-pumped laser applications.
[Behavior of different strains of Staphylococcus aureus against root canal filling cements].
Pumarola, J; Berástegui, E; Canalda, C; Brau, E
1991-01-01
The mean goal of this study is the determination of the conduct of 120 strains of Staphylococcus aureus against seven root canal sealers: Traitement Spad, Endométhasone, N2 Universal, AH26 with silver, Diaket-A, Tubli Seal and Sealapex. The agar diffusion test was employed in the determination of its bacterial growth inhibition. The results obtained have demonstrated values very different between the tested strains. Therefore we recommended to employ strains with reference in the investigation of the bacterial growth inhibition in order to repeat equal experimentation conditions.
Blood filling and flow in lungs during change in body position in space
NASA Technical Reports Server (NTRS)
Pogodin, A. S.; Mazhbich, B. I.
1980-01-01
In the horizontal position (supine and lateral), in the upright position (head up and head down) and during change of the cat body position in space, quantitative responses of regional blood volume and blood flow in the lungs (ml/100 cu cm) revealed presence of the gradient in the gravitation direction. Blood volume and blood flow of different lung portions changed qualitatively and quantitatively in different ways. These changes occurred only in the direction producing the equality of regional hydrostatical and hemodynamic loads in the lungs at either horizontal level.
Evaluation of Catalytic and Thermal Cracking in a JP-8 Fueled Pulsed Detonation Engine (Postprint)
2007-09-01
this research. Each 0.91-m-long heat exchanger was fabricated with a 50.8-mm-dia, inconel - 625 , Schedule-10 inner tube and a 63.5-mm-dia, inconel -600...detonation tube had an inconel heat exchanger (described later). The PDE cycle consisted of three equally timed phases--fill, fire, and purge, as shown in...prevent phase change. The fuel was pressure fed to the inlet of the fuel heating system (FHS). The FHS consisted of two inconel heat exchangers, a
Guiomar, Fernando P; Reis, Jacklyn D; Carena, Andrea; Bosco, Gabriella; Teixeira, António L; Pinto, Armando N
2013-01-14
Employing 100G polarization-multiplexed quaternary phase-shift keying (PM-QPSK) signals, we experimentally demonstrate a dual-polarization Volterra series nonlinear equalizer (VSNE) applied in frequency-domain, to mitigate intra-channel nonlinearities. The performance of the dual-polarization VSNE is assessed in both single-channel and in wavelength-division multiplexing (WDM) scenarios, providing direct comparisons with its single-polarization version and with the widely studied back-propagation split-step Fourier (SSF) approach. In single-channel transmission, the optimum power has been increased by about 1 dB, relatively to the single-polarization equalizers, and up to 3 dB over linear equalization, with a corresponding bit error rate (BER) reduction of up to 63% and 85%, respectively. Despite of the impact of inter-channel nonlinearities, we show that intra-channel nonlinear equalization is still able to provide approximately 1 dB improvement in the optimum power and a BER reduction of ~33%, considering a 66 GHz WDM grid. By means of simulation, we demonstrate that the performance of nonlinear equalization can be substantially enhanced if both optical and electrical filtering are optimized, enabling the VSNE technique to outperform its SSF counterpart at high input powers.
Single phase four pole/six pole motor
Kirschbaum, Herbert S.
1984-01-01
A single phase alternating current electric motor is provided with a main stator winding having two coil groups each including the series connection of three coils. These coil groups can be connected in series for six pole operation and in parallel for four pole operation. The coils are approximately equally spaced around the periphery of the machine but are not of equal numbers of turns. The two coil groups are identically wound and spaced 180 mechanical degrees apart. One coil of each group has more turns and a greater span than the other two coils.
Throat quantization of the Schwarzschild-Tangherlini(-AdS) black hole
NASA Astrophysics Data System (ADS)
Maeda, Hideki
2018-01-01
By the throat quantization pioneered by Louko and Mäkelä, we derive the mass and area/entropy spectra for the Schwarzschild-Tangherlini-type asymptotically flat or AdS vacuum black hole in arbitrary dimensions. Using the WKB approximation for black holes with large mass, we show that area/entropy is equally spaced for asymptotically flat black holes, while mass is equally spaced for asymptotically AdS black holes. Exact spectra can be obtained for toroidal AdS black holes in arbitrary dimensions including the three-dimensional BTZ black hole.
Crystallization Kinetics of Amorphous AgInS2 Film
NASA Astrophysics Data System (ADS)
Kerimova, N. K.; Mamedova, A. Ch.
2018-04-01
The paper deals with crystallization kinetics of amorphous AgInS2 film. The dependence between lnln(V0 / (V0 -Vt) and lnt is obtained for 423, 448 and 468 K temperatures, which shows a linear arrangement of points for these temperatures, i.e. 2.80 2.87 and 2.93, respectively. The approximate equality of these values indicates that during AgInS2 film crystallization, a two-dimensional crystal growth occurs and the reaction rate constant equals (1/3π) {η}_n{η}_c^2.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Oliveira, Ednilton S.; Crispino, Luis C. B.; Higuchi, Atsushi
2011-10-15
The absorption cross section of Reissner-Nordstroem black holes for the gravitational field is computed numerically, taking into account the coupling of the electromagnetic and gravitational perturbations. Our results are in excellent agreement with low- and high-frequency approximations. We find equality between gravitational and electromagnetic absorption cross sections of extreme Reissner-Nordstroem black holes for all frequencies, which we explain analytically. This gives the first example of objects in general relativity in four dimensions that absorb the electromagnetic and gravitational waves in exactly the same way.
The benefits auditor and the detective.
Gerver, Howard
2003-09-01
As health care grows more complex, the ability to discover overpayments has grown equally challenging. Given the high cost of health care and the expected annual trend of approximately 15% for the next several years, stopping profit losses is critical in any organization.
Costs and Benefits of Fly Ash Control (1973)
The purpose of this paper is to provide qualified answers to these questions: What level of charge will induce a power plant operator to meet the standards? Is the standard one at which marginal costs are approximately equal to marginal benefits?
2010-09-22
An Omega 100-ohm RTD was mounted underneath the port wing of the O-2A for total temperature measurements. The five-hole probe was always mounted to...turbulence. At -5.07 degrees AoA, the entire model starts to fill in with a turbulent transition front that creeps forward slightly to approximately
40 CFR 86.232-94 - Vehicle preconditioning.
Code of Federal Regulations, 2011 CFR
2011-07-01
... vehicle shall be moved to the test area and the following operations performed: (1) The fuel tank(s) shall be filled to approximately the prescribed “tank fuel volume” with the test fuel specified § 86.213. If the existing fuel in the fuel tank(s) does not meet the specifications contained in § 86.213, the...
Garrell E. Nicholes
1980-01-01
Today I would like to start this part of my program by generally describing the vehicles, the users, and the current problems. Later on I will break out specifically motorcycles and snowmobiles to discuss. When I was asked, approximately a year ago, to fill this assignment, I began by telephoning those I knew in public and private ORV management positions. I sent...
16 CFR 1631.62 - Wool flokati carpets and rugs-alternative washing procedure.
Code of Federal Regulations, 2014 CFR
2014-01-01
... restore surface and fluff up fibers. 3. Spot cleaning: Remove greasy stains with a household grease remover. Remove soluble stains with lukewarm water (approximately 105 °F.) and detergent by immersing spot... a shallow pan which has been filled to a depth of 2” with a wash solution of 1.1 grams of AATCC...
16 CFR 1631.62 - Wool flokati carpets and rugs-alternative washing procedure.
Code of Federal Regulations, 2011 CFR
2011-01-01
... restore surface and fluff up fibers. 3. Spot cleaning: Remove greasy stains with a household grease remover. Remove soluble stains with lukewarm water (approximately 105 °F.) and detergent by immersing spot... a shallow pan which has been filled to a depth of 2” with a wash solution of 1.1 grams of AATCC...
16 CFR 1630.62 - Wool flokati carpets and rugs-alternative washing procedure.
Code of Federal Regulations, 2012 CFR
2012-01-01
... restore surface and fluff up fibers. 3. Spot cleaning: Remove greasy stains with a household grease remover. Remove soluble stains with lukewarm water (approximately 105 °F.) and detergent by immersing spot... a shallow pan which has been filled to a depth of 2″ with a wash solution of 1.1 grams of AATCC...
16 CFR 1630.62 - Wool flokati carpets and rugs-alternative washing procedure.
Code of Federal Regulations, 2014 CFR
2014-01-01
... restore surface and fluff up fibers. 3. Spot cleaning: Remove greasy stains with a household grease remover. Remove soluble stains with lukewarm water (approximately 105 °F.) and detergent by immersing spot... a shallow pan which has been filled to a depth of 2″ with a wash solution of 1.1 grams of AATCC...
16 CFR 1631.62 - Wool flokati carpets and rugs-alternative washing procedure.
Code of Federal Regulations, 2010 CFR
2010-01-01
... restore surface and fluff up fibers. 3. Spot cleaning: Remove greasy stains with a household grease remover. Remove soluble stains with lukewarm water (approximately 105 °F.) and detergent by immersing spot... a shallow pan which has been filled to a depth of 2” with a wash solution of 1.1 grams of AATCC...
16 CFR 1630.62 - Wool flokati carpets and rugs-alternative washing procedure.
Code of Federal Regulations, 2010 CFR
2010-01-01
... restore surface and fluff up fibers. 3. Spot cleaning: Remove greasy stains with a household grease remover. Remove soluble stains with lukewarm water (approximately 105 °F.) and detergent by immersing spot... a shallow pan which has been filled to a depth of 2″ with a wash solution of 1.1 grams of AATCC...
16 CFR 1631.62 - Wool flokati carpets and rugs-alternative washing procedure.
Code of Federal Regulations, 2012 CFR
2012-01-01
... restore surface and fluff up fibers. 3. Spot cleaning: Remove greasy stains with a household grease remover. Remove soluble stains with lukewarm water (approximately 105 °F.) and detergent by immersing spot... a shallow pan which has been filled to a depth of 2” with a wash solution of 1.1 grams of AATCC...
16 CFR 1630.62 - Wool flokati carpets and rugs-alternative washing procedure.
Code of Federal Regulations, 2011 CFR
2011-01-01
... restore surface and fluff up fibers. 3. Spot cleaning: Remove greasy stains with a household grease remover. Remove soluble stains with lukewarm water (approximately 105 °F.) and detergent by immersing spot... a shallow pan which has been filled to a depth of 2″ with a wash solution of 1.1 grams of AATCC...
Carbon Nanotube Thermal Interfaces Enhanced with Sprayed on Nanoscale Polymer Coatings
2013-02-20
temperature of the growth stage was lowered to 750 ◦C (a pyrometer measured the actual sample temperature to be approximately 630 ◦C, which is less than the...the heat is absorbed at the sample surface it is conducted both downward through the sample and upward into an acoustic chamber filled with He gas. The
Fiber optic refractive index monitor
Weiss, Jonathan David
2002-01-01
A sensor for measuring the change in refractive index of a liquid uses the lowest critical angle of a normal fiber optic to achieve sensitivity when the index of the liquid is significantly less than the index of the fiber core. Another embodiment uses a liquid filled core to ensure that its index is approximately the same as the liquid being measured.
De Deus, Gustavo A; Gurgel-Filho, Eduardo Diogo; Maniglia-Ferreira, Cláudio; Coutinho-Filho, Tauby
2004-04-01
The purpose of this study was to compare the depth of sealer penetration into dentinal tubules by three root-filling techniques using light microscopy and digital image processing. Thirty-two maxillary central incisors were prepared. Two teeth were separated for the control group. The rest were divided into three equal groups and obturated as following--G1: lateral condensation; G2: warm vertical compaction of gutta-percha and G3: Thermafil system. Each sample was sectioned longitudinally and prepared for microscopic analysis. A sequence of photomicrographs with magnifications of X50, X200 and X500 were taken. Through digital image analysis and processing, measurements for each field were obtained. A non-parametric ANOVA Kruskal-Wallis analysis was used to determine whether there were significant differences among the groups. Significant differences between G2 and G1 (p = 0.034) and between G3 and G1 (p = 0.021) were identified. There were no significant differences between G2 and G3 (p > 0.05). The results of this research suggest that samples root-filled by thermoplasticised gutta-percha techniques lead to deeper penetration of the root canal sealer into the dentinal tubules.
Investigation of two-phase thermosyphon performance filled with modern HFC refrigerants
NASA Astrophysics Data System (ADS)
Gorecki, Grzegorz
2018-02-01
Two-phase closed thermosyphons (TPCTs) are widely utilized as heat exchanger elements in waste heat recovery systems and as passive heating/cooling devices. They are popular because of their high thermal conductivity, simple construction and reliability. Previous researches indicate that refrigerants are performing better than typical TPCT working fluids like deionized water or alcohols in the low temperature range. In the present study three HFC (Hydrofluorocarbons) refrigerants were tested: R134a, R404A and R407C. The total length of the investigated TPCT is 550 mm with equal length (245 mm) condenser and evaporator sections. Its outer diameter is 22 mm with 1 mm wall thickness. The evaporator section was heated by hot water with varying inlet temperature by 5 K step in the range of 288 K - 323 K. The condenser was cooled by cold water with inlet temperature kept at a constant value of 283 K. It was found that using R134a and R404A as working fluids heat transfer rates are the highest. For both refrigerants 10% is optimal filling ratio. They can be utilized interchangeably because the differences between their throughputs are within uncertainty bands. R407C performance was 50% lower. Other disadvantages of using this refrigerant are relatively high working pressures and higher optimal filling ratio (30%).
Investigation of two-phase thermosyphon performance filled with modern HFC refrigerants
NASA Astrophysics Data System (ADS)
Gorecki, Grzegorz
2018-07-01
Two-phase closed thermosyphons (TPCTs) are widely utilized as heat exchanger elements in waste heat recovery systems and as passive heating/cooling devices. They are popular because of their high thermal conductivity, simple construction and reliability. Previous researches indicate that refrigerants are performing better than typical TPCT working fluids like deionized water or alcohols in the low temperature range. In the present study three HFC (Hydrofluorocarbons) refrigerants were tested: R134a, R404A and R407C. The total length of the investigated TPCT is 550 mm with equal length (245 mm) condenser and evaporator sections. Its outer diameter is 22 mm with 1 mm wall thickness. The evaporator section was heated by hot water with varying inlet temperature by 5 K step in the range of 288 K - 323 K. The condenser was cooled by cold water with inlet temperature kept at a constant value of 283 K. It was found that using R134a and R404A as working fluids heat transfer rates are the highest. For both refrigerants 10% is optimal filling ratio. They can be utilized interchangeably because the differences between their throughputs are within uncertainty bands. R407C performance was 50% lower. Other disadvantages of using this refrigerant are relatively high working pressures and higher optimal filling ratio (30%).
Design and biocompatibility of endovascular aneurysm filling devices
Rodriguez, Jennifer N.; Hwang, Wonjun; Horn, John; ...
2014-08-04
We report that the rupture of an intracranial aneurysm, which can result in severe mental disabilities or death, affects approximately 30,000 people in the United States annually. The traditional surgical method of treating these arterial malformations involves a full craniotomy procedure, wherein a clip is placed around the aneurysm neck. In recent decades, research and device development have focused on new endovascular treatment methods to occlude the aneurysm void space. These methods, some of which are currently in clinical use, utilize metal, polymeric, or hybrid devices delivered via catheter to the aneurysm site. In this review, we present several suchmore » devices, including those that have been approved for clinical use, and some that are currently in development. We present several design requirements for a successful aneurysm filling device and discuss the success or failure of current and past technologies. Lastly, we also present novel polymeric based aneurysm filling methods that are currently being tested in animal models that could result in superior healing.« less
NASA Astrophysics Data System (ADS)
Behmand, Saleh Alaei; Mirsalehi, Seyyed Ehsan; Omidvar, Hamid; Safarkhanian, Mohammad Ali
2016-10-01
In this article, filling friction stir welding (FFSW) of the remaining exit holes of AA5456 alloy friction-stir-welded lap joints was studied. For this purpose, the influences of different rotating speeds, holding times, and pin materials, AA5456 and AA2024, on the metallurgical structure and joint strength were investigated. The observations showed that defect-free lap joints are successfully obtainable by this method using similar and dissimilar consumable pins. The results indicated that the higher rotating speed and holding time adversely affect the weld performance. The best result was achieved for 30 seconds holding time, 500 rpm rotating speed, and AA2024 consumable pin. In this condition, a lap shear strength of 10 pct higher than that of the nonfilled joint, equivalent to about 94 pct of the original defect-free FSW joint, was obtained, whereas the GTAW filled joint showed only approximately 87 pct of the continuous FSW joint strength.
Design and biocompatibility of endovascular aneurysm filling devices
Rodriguez, Jennifer N.; Hwang, Wonjun; Horn, John; Landsman, Todd L.; Boyle, Anthony; Wierzbicki, Mark A.; Hasan, Sayyeda M.; Follmer, Douglas; Bryant, Jesse; Small, Ward; Maitland, Duncan J.
2014-01-01
The rupture of an intracranial aneurysm, which can result in severe mental disabilities or death, affects approximately 30,000 people in the United States annually. The traditional surgical method of treating these arterial malformations involves a full craniotomy procedure, wherein a clip is placed around the aneurysm neck. In recent decades, research and device development have focused on new endovascular treatment methods to occlude the aneurysm void space. These methods, some of which are currently in clinical use, utilize metal, polymeric, or hybrid devices delivered via catheter to the aneurysm site. In this review, we present several such devices, including those that have been approved for clinical use, and some that are currently in development. We present several design requirements for a successful aneurysm filling device and discuss the success or failure of current and past technologies. We also present novel polymeric based aneurysm filling methods that are currently being tested in animal models that could result in superior healing. PMID:25044644
Optical properties of anisotropic 3D nanoparticles arrays
NASA Astrophysics Data System (ADS)
Santiago, E. Y.; Esquivel-Sirvent, R.
2017-07-01
The optical properties of 3D periodic arrays of spheroidal Au nanoparticles are calculated using a Bruggeman effective medium approximation. The optical response of the supra-crystal depends on the volume fraction of the nanoparticles and their aspect or size ratio (major/minor axis). All the nanoparticles have the same orientation, and this defines an anisotropic dielectric function of the crystal. As a function of the filling fraction, while keeping the size ratio fixed, the maximum in the extinction spectra along the major and minor axes does not show a significant change. However, for a fixed filling fraction, varying the aspect ratio of the particles induces a shift of several hundred of nanometers in the maximum of the extinction spectra along the major axis and almost no changes along the minor axis. Depending on the aspect ratio and the filling fraction, we show that the supra-crystal has three regimes with different values of an effective plasma frequency. Contribution to the Focus Issue Self-assemblies of Inorganic and Organic Nanomaterials edited by Marie-Paule Pileni.
NASA Technical Reports Server (NTRS)
Stauffer, John R.; Liebert, James; Giampapa, Mark
1995-01-01
We have determined H alpha equivalent widths and radial velocities with 1 sigma accuracies of approximately 5 km/s for approximately 20 candidate very low mass members of the Pleiades cluster and for a few proposed very low mass members of the Hyades. Most of the Pleiades targets were selected from the recent Hambly, Hawkins, and Jameson proper motion survey, where they were identified as probable Pleiades brown dwarfs with an age spread from 3 to 70 Myr. Our spectroscopic data and a reinterpretation of the photometric data confirm that these objects are indeed likely Pleiades members; however, we believe that they more likely have masses slightly above the hydrogen burning mass limit and that there is no firm evidence for an age spread amongst these stars. All of the very low mass Pleiades and Hyades members show H alpha in emission. However, the ratio of H alpha flux to biometric flux in the Pleiades shows a maximum near M(sub Bol) approximately equal to 9.5 (M approximately equal to 0.3 solar mass) and a sharp decrease to lower masses. This break occurs at the approximate mass where low mass stars are expected to become fully convective, and it is tempting to assume that the decrease in H alpha flux is caused by some change in the behavior of stellar dynamos at this mass. We do not see a similar break in activity at this mass in the Hyades. We discuss possible evolutionary explanations for this difference in the H alpha activity between the two clusters.
Effect of twist on single-mode fiber-optic 3 × 3 couplers
NASA Astrophysics Data System (ADS)
Chen, Dandan; Ji, Minning; Peng, Lei
2018-01-01
In the fabricating process of a 3 × 3 fused tapered coupler, the three fibers are usually twisted to be close-contact. The effect of twist on 3 × 3 fused tapered couplers is investigated in this paper. It is found that though a linear 3 × 3 coupler may realize equal power splitting ratio theoretically by twisting a special angle, it is hard to be fabricated actually because the twist angle and the coupler's length must be determined in advance. While an equilateral 3 × 3 coupler can not only realize approximate equal power splitting ratio theoretically but can also be fabricated just by controlling the elongation length. The effect of twist on the equilateral 3 × 3 coupler lies in the relationship between the equal ratio error and the twist angle. The more the twist angle is, the larger the equal ratio error may be. The twist angle usually should be no larger than 90° on one coupling period length in order to keep the equal ratio error small enough. The simulation results agree well with the experimental data.
Noniterative estimation of a nonlinear parameter
NASA Technical Reports Server (NTRS)
Bergstroem, A.
1973-01-01
An algorithm is described which solves the parameters X = (x1,x2,...,xm) and p in an approximation problem Ax nearly equal to y(p), where the parameter p occurs nonlinearly in y. Instead of linearization methods, which require an approximate value of p to be supplied as a priori information, and which may lead to the finding of local minima, the proposed algorithm finds the global minimum by permitting the use of series expansions of arbitrary order, exploiting an a priori knowledge that the addition of a particular function, corresponding to a new column in A, will not improve the goodness of the approximation.
Vasin, A L
2003-01-01
Appropriateness of representation of a biological object surface as an equipotential surface has been proved for conditions of a quasistatic exposure to EMF of frequencies lower than 1 MHz. The conditions, at which a self capacitance of a biological object is its basic electrical parameter, have been considered. A factor of animal-to-human approximation of low-frequency EMF exposure conditions was estimated on the basis of equal dose loading in biological objects of different geometric sizes.
Evidence for crustacean cardioactive peptide-like innervation of the gut in Locusta migratoria.
Donini, Andrew; Ngo, Caroline; Lange, Angela B
2002-11-01
Hindguts from female Vth instar larvae, young adults (1-2 days) and old adults (>10 days) are equally sensitive to the crustacean cardioactive peptide (CCAP), with changes in contraction occurring at a threshold concentration of 10(-9)M and maximal responses observed at concentrations ranging between 10(-7) and 5x10(-6)M. An immunohistochemical examination of the gut of Locusta migratoria with an antiserum raised against CCAP revealed an extensive network of CCAP-like immunoreactive processes on the hindgut and posterior midgut via the 11th sternal nerve arising from the terminal abdominal ganglion. Anterograde filling of the 11th sternal nerve with neurobiotin revealed extensive processes and terminals on the hindgut. Retrograde filling of the branch of the 11th sternal nerve which innervates the hindgut with neurobiotin revealed two bilaterally paired cells in the terminal abdominal ganglion which co-localized with CCAP-like immunoreactivity. Results suggest that a CCAP-like substance acts as a neurotransmitter/neuromodulator at the locust hindgut.
Theoretical analysis of start-up power in helium pulsating heat pipe
NASA Astrophysics Data System (ADS)
Li, Monan; Huang, Rongjin; Xu, Dong; Li, Laifeng
2017-02-01
An analytical model for one-turn helium pulsating heat pipes (PHPs) with single liquid slug and vapor plug is established in present study. When an additional heat power takes place in the evaporating section, temperature and pressure will increase. The pressure wave travels through vapor and liquid phases at different speed, producing a pressure difference in the system, which acts as an exciting force to start up the oscillating motion. Results show that the start-up power of helium PHP is related to the filling ratio. The start-up power increases with the filling ration. However, there exist an upper limit. Furthermore, the start-up power also depends on the inclination angle of PHP. When the inclination angle increases, the heat input needed to start up the oscillating motion decreases. But for one-turn helium PHP, it can not be started up when the inclination angle is up to 90°, equalling to horizontal position,. While the inclination angle ranges between 0° (vertical position) and 75°, it can operate successfully.
Self Diffusion in Nano Filled Polymer Melts: a Molecular Dynamics Simulation Study
NASA Astrophysics Data System (ADS)
Desai, Tapan; Keblinski, Pawel
2003-03-01
SELF DIFFUSION IN NANO FILLED POLYMER MELTS: A MOLECULAR DYNAMICS SIMULATION STUDY* T. G. Desai,P. Keblinski, Material Science and Engineering Department, Rensselaer Polytechnic Institute, Troy, NY. Using molecular dynamics simulations, we studied the dynamics of the polymeric systems containing immobile and analytically smooth spherical nanoparticles. Each chain consisted of N monomers connected by an anharmonic springs described by the finite extendible nonlinear elastic, FENE potential. The system comprises of 3nanoparticles and the rest by freely rotating but not overlapping chains. The longest chain studied has a Radius of gyration equal to particle size radius and comparable to inter-particle distance. There is no effect on the structural characteristics such as Radius of gyration or end to end distance due to the nanoparticles. Diffusion of polymeric chains is not affected by the presence of either attractive or repulsive nanoparticles. In all cases Rouse dynamics is observed for short chains with a crossover to reptation dynamics for longer chains.
NASA Astrophysics Data System (ADS)
Houjoh, Haruo
1992-12-01
One specific feature of the aerodynamic sound produced at the face end region is that the radiation becomes equally weak by filling root spaces as by shortening the center distance. However, one can easily expect that such actions make the air flow faster, and consequently make the sound louder. This paper attempts to reveal the reason for such a feature. First, air flow induced by the pumping action of the gear pair was analyzed regarding a series of root spaces as volume varying cavities which have channels to adjacent cavities as well as the exit/inlet at the face ends. The numerical analysis was verified by the hot wire anemometer measurement. Next, from the obtained flow response, the sound source was estimated to be a combination of symmetrically distributed simple sources. Taking the effect of either the center distance or root filling into consideration, it is shown that the simplified model can explain such a feature rationally.
Refractive index investigation of poly(vinyl alcohol) films with TiO2 nanoparticle inclusions.
Yovcheva, Temenuzhka; Vlaeva, Ivanka; Bodurov, Ivan; Dragostinova, Violeta; Sainov, Simeon
2012-11-10
The refractive index (RI) of polymer nanocomposite of poly(vinyl alcohol) films with TiO(2) nanoparticle inclusions with low concentration up to 1.2 wt. % was investigated. Accurate refractometric measurements, by a specially designed laser microrefractometer, were performed at wavelengths 532 and 632.8 nm. The influence of TiO(2) concentration on the RI dispersion curves was predicted based on the well-known Sellmeier model. The theoretical analysis, in a small filling factor approximation, was performed, and a relation between the effective RI of the nanocomposite and weight concentrations of the TiO(2) nanofiller was derived. The experimental values were approximated by two different functions (linear and a quadratic polynom). The polynomial approximation yields better result, where R(2)=0.90.
Chen, Feng-Jing; Etzler, Frank M; Ubben, Johanna; Birch, Amy; Zhong, Li; Schwabe, Robert; Dudhedia, Mayur S
2010-01-01
The present study investigated the effect of lipophilic components on the compatibility of propylene glycol (PG)-containing lipid-based drug delivery system (LBDDS) formulations with hard gelatin capsules. The presence of a lipophilic active pharmaceutical ingredient (API) (log P approximately 6.1) and an additional lipophilic excipient (Capmul MCM) significantly affected the activity of PG in the fills and the equilibrium of PG between capsule shells and fills. These changes in activity and equilibrium of PG were furthermore correlated to the mechanical and thermal properties of the liquid-filled capsules and subsequently linked to the shelf-life of the capsules on stability with respect to capsule deformation. The present study also investigated the mechanism by which lipophilic component(s) might affect the activity of PG in the fill formulations and the equilibrium of PG between capsule shells and fills. The activities of PG in two series of "binary" mixtures with Capmul MCM and with Cremophor EL were measured, respectively. The mixtures of PG containing Capmul MCM were found to be more nearly ideal than those containing Cremophor EL. The observed negative deviation from Rauolt's law indicates that the excess free energies of mixing are less then zero indicating favorable interaction between PG and the other component. It is speculated that enhanced hydrogen bonding opportunities with Cremophor EL are responsible for the decreased excess free energy of mixing. Replacement of Cremophor EL with lipophilic API also reduces the hydrogen bonding opportunities for PG in the mixtures. This hypothesis may further explain the increased activity of PG in the fills and the shifted equilibrium of PG toward the capsule shells. Activity determination utilizing headspace gas chromatography (GC) using short 30 min incubation time seems to be a time-efficient approach for assessing capsule-fill compatibility. Direct measurements of PG migration and other physical properties of the capsules took much longer time (7 weeks) for ranking the predicted capsule deformation at 40 degrees C. Asides from the time savings, activity determination can be considered to be material sparing by offering capsule-fill compatibility assessment even without the need for preparing liquid-filled capsules once appropriate positive and negative references are established. With further optimization, this approach should enable high throughput screening of LBDDS for capsule-fill compatibility in liquid-filled capsule development.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
1994-08-01
This document is a report on the remedial investigation (RI) of Chestnut Ridge Operable Unit (OU) 2 at the Oak Ridge Y-12 Plant. Chestnut Ridge OU 2 consists of Upper McCoy Branch (UMB), the Filled Coal Ash Pond (FCAP), and the area surrounding the Sluice Channel formerly associated with coal ash disposal in the FCAP. Chestnut Ridge OU 2 is located within the U.S. Department of Energy`s (DOE`s) Oak Ridge Reservation in Anderson County, Tennessee, approximately 24 miles west of Knoxville. The pond is an 8.5-acre area on the southern slope of Chestnut Ridge, 0.5 mile south of the mainmore » Y-12 Plant and geographically separated from the Y-12 Plant by Chestnut Ridge. The elevation of the FCAP is {approximately} 950 ft above mean sea level (msl), and it is relatively flat and largely vegetated. Two small ponds are usually present at the northeast and northwest comers of the FCAP. The Sluice Channel Area extends {approximately}1000 ft from the northern margin of the FCAP to the crest of Chestnut Ridge, which has an elevation of {approximately}1100 ft above msl. The Sluice Channel Area is largely vegetated also. McCoy Branch runs from the top of Chestnut Ridge across the FCAP into Rogers Quarry and out of the quarry where it runs a short distance into Milton Hill Lake at McCoy Embayment, termed UMB. The portion south of Rogers Quarry, within Chestnut Ridge OU 4, is termed Lower McCoy Branch. The DOE Oak Ridge Y-12 Plant disposed of coal ash from its steam plant operations as a slurry that was discharged into an ash retention impoundment; this impoundment is the FCAP. The FCAP was built in 1955 to serve as a settling basin after coal ash slurried over Chestnut Ridge from the Y-12 Plant. The FCAP was constructed by building an earthen dam across the northern tributary of McCoy Branch. The dam was designed to hold 20 years of Y-12 steam plant ash. By July 1967, ash had filled up the impoundment storage behind the dam to within 4 ft of the top.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kauweloa, Kevin I., E-mail: Kauweloa@livemail.uthscsa.edu; Gutierrez, Alonso N.; Bergamo, Angelo
2014-07-15
Purpose: There is a growing interest in the radiation oncology community to use the biological effective dose (BED) rather than the physical dose (PD) in treatment plan evaluation and optimization due to its stronger correlation with radiobiological effects. Radiotherapy patients may receive treatments involving a single only phase or multiple phases (e.g., primary and boost). Since most treatment planning systems cannot calculate the analytical BED distribution in multiphase treatments, an approximate multiphase BED expression, which is based on the total physical dose distribution, has been used. The purpose of this paper is to reveal the mathematical properties of the approximatemore » BED formulation, relative to the true BED. Methods: The mathematical properties of the approximate multiphase BED equation are analyzed and evaluated. In order to better understand the accuracy of the approximate multiphase BED equation, the true multiphase BED equation was derived and the mathematical differences between the true and approximate multiphase BED equations were determined. The magnitude of its inaccuracies under common clinical circumstances was also studied. All calculations were performed on a voxel-by-voxel basis using the three-dimensional dose matrices. Results: Results showed that the approximate multiphase BED equation is accurate only when the dose-per-fractions (DPFs) in both the first and second phases are equal, which occur when the dose distribution does not significantly change between the phases. In the case of heterogeneous dose distributions, which significantly vary between the phases, there are fewer occurrences of equal DPFs and hence the inaccuracy of the approximate multiphase BED is greater. These characteristics are usually seen in the dose distributions being delivered to organs at risk rather than to targets. Conclusions: The finding of this study indicates that the true multiphase BED equation should be implemented in the treatment planning systems due to the inconsistent accuracy of the approximate multiphase BED equation in most of the clinical situations.« less
NASA Technical Reports Server (NTRS)
Smith, Peter L.; Stark, G.; Yoshino, K.; Ito, K.
1994-01-01
Band oscillator strengths (f-values) for four bands of the Fourth Positive system (A (1)Pi - Chi(sup 1) Sigma(+)) of CO have been determined from high-resolution (lambda/Delta lambda approximately equal to 150,000) absorption spectra. The bands, (14, 0) through (11, 0), are at wavelengths between 121 and 127 nm. Our f-values for the (11, 0) and (12, 0) bands support those of Chan, Cooper, & Brion (1993), which have been shown to be consistent with observations of CO in the clouds in the line of sight to zeta Oph. Our f-values for the (13, 0) and (14, 0) bands are the first directly measured values for these bands.
Evidence for the equality of the solar photospheric and coronal abundance of iron
NASA Technical Reports Server (NTRS)
Phillips, K. J. H.; Pike, C. D.; Lang, J.; Zarro, D. M.; Fludra, A.; Watanabe, T.; Takahashi, M.
1995-01-01
The Fe K-alpha and K-beta X-ray lines (wavelengths 1.94 and 1.76 A) in the solar X-ray spectrum are formed by fluoroescence of photospheric iron atoms, and the ratio of the intensity of either to the He-like iron (Fe XXV) resonance line at 1.85 A is a function of the photospheric-to-coronal abundance of iron. The temperature dependence of this ratio is weak as long as the flare temperature T(sub e) greater than or approximately equal to 15 x 10(exp 6)K. Comparison of the theoretical value of this intensity ratio with observations from crystal spectrometers on Yohkoh, Solar Maximum Mission (SMM) and P78-1 are consistent with the photospheric abundance of Fe being equal to the coronal.