Science.gov

Sample records for cone penetration tests

  1. Analysis: Prediction of Pile Capacity Using the Cone Penetration Test

    DTIC Science & Technology

    1989-01-01

    capacity measurements with frictional resistance measurements, many theoretical and empirical correlations have been developed to determine various...geotechnical parameters. Cone penetration test results have been commonly used to determine such parameters as soil classification, friction angle ...tensile strength were added to the sand resulting in an increased stiffness, but the friction angle of the sand remained essentially unchanged. In

  2. Probabilistic liquefaction triggering based on the cone penetration test

    USGS Publications Warehouse

    Moss, R.E.S.; Seed, R.B.; Kayen, R.E.; Stewart, J.P.; Tokimatsu, K.

    2005-01-01

    Performance-based earthquake engineering requires a probabilistic treatment of potential failure modes in order to accurately quantify the overall stability of the system. This paper is a summary of the application portions of the probabilistic liquefaction triggering correlations proposed recently proposed by Moss and co-workers. To enable probabilistic treatment of liquefaction triggering, the variables comprising the seismic load and the liquefaction resistance were treated as inherently uncertain. Supporting data from an extensive Cone Penetration Test (CPT)-based liquefaction case history database were used to develop a probabilistic correlation. The methods used to measure the uncertainty of the load and resistance variables, how the interactions of these variables were treated using Bayesian updating, and how reliability analysis was applied to produce curves of equal probability of liquefaction are presented. The normalization for effective overburden stress, the magnitude correlated duration weighting factor, and the non-linear shear mass participation factor used are also discussed.

  3. Discrete Element Method (DEM) Application to The Cone Penetration Test Using COUPi Model

    NASA Astrophysics Data System (ADS)

    Kulchitsky, A. V.; Johnson, J.; Wilkinson, A.; DeGennaro, A. J.; Duvoy, P.

    2011-12-01

    The cone penetration test (CPT) is a soil strength measurement method to determine the tip resistance and sleeve friction versus depth while pushing a cone into regolith with controlled slow quasi-static speed. This test can also be used as an excellent tool to validate the discrete element method (DEM) model by comparing tip resistance and sleeve friction from experiments to model results. DEM by nature requires significant computational resources even for a limited number of particles. Thus, it is important to find particle and ensemble parameters that produce valuable results within reasonable computation times. The Controllable Objects Unbounded Particles Interaction (COUPi) model is a general physical DEM code being developed to model machine/regolith interactions as part of a NASA Lunar Science Institute sponsored project on excavation and mobility modeling. In this work, we consider how different particle shape and size distributions defined in the DEM influence the cone tip and friction sleeve resistance in a CPT DEM simulation. The results are compared to experiments with cone penetration in JSC-1A lunar regolith simulant. The particle shapes include spherical particles, particles composed from the union of three spheres, and some simple polyhedra. This focus is driven by the soil mechanics rule of thumb that particle size and shape distributions are the two most significant factors affecting soil strength. In addition to the particle properties, the packing configuration of an ensemble strongly affects soil strength. Bulk density of the regolith is an important characteristic that significantly influences the tip resistance and sleeve friction (Figure 1). We discuss different approaches used to control granular density in the DEM, including how to obtain higher bulk densities, using numerical "shaking" techniques and varying the friction coefficient during computations.

  4. Cone penetration and bevameter geotechnical tests in lunar regolith simulants: discrete element method analysis and experimentation

    NASA Astrophysics Data System (ADS)

    Kulchitsky, A. V.; Johnson, J.; Duvoy, P.; Wilkinson, A.; Creager, C. M.

    2012-12-01

    For in situ resource utilization on the Moon, asteroids, Mars, or other space body it is necessary to be able to simulate the interaction of mobile platforms and excavation machines with the regolith for engineering design, planning, and operations. For accurate simulations, tools designed to measure regolith properties will need to be deployed and interpreted. Two such tools are the penetrometer, used to measure a soil strength index as a function of depth, and the bevameter, used to characterize regolith surface properties of strength, friction and sinkage. The penetrometer interrogates regolith properties from the surface to a depth limited only by the capabilities of the instrument to penetrate the regolith while a bevameter interrogates only the upper few centimeters needed to describe a mobility platform's traction and sinkage. Interpretation of penetrometer and bevameter data can be difficult, especially on low gravity objects. We use the discrete element method (DEM) model to simulate the large regolith deformations and failures associated with the tests to determine regolith properties. The DEM simulates granular material behavior using large aggregates of distinct particles. Realistic physics of particle-particle interaction introduces many granular specific phenomena such as interlocking and force chain formation that cannot be represented using continuum methods. In this work, experiments using a cone penetrometer test (CPT) and bevameter on lunar simulants JSC-1A and GRC-1 were performed at NASA Glenn Research Center. These tests were used to validate the physics in the COUPi DEM model. COUPi is a general physical DEM code being developed to model machine/regolith interactions as part of a NASA Lunar Science Institute sponsored project on excavation and mobility modeling. The experimental results were used in this work to build an accurate model to simulate the lunar regolith. The CPT consists of driving an instrumented cone with opening angle of 60

  5. Cone penetration tests and soil borings at the Mason Road site in Green Valley, Solano County, California

    USGS Publications Warehouse

    Bennett, Michael J.; Noce, Thomas E.; Lienkaemper, James J.

    2011-01-01

    In support of a study to investigate the history of the Green Valley Fault, 13 cone penetration test soundings and 3 auger borings were made at the Mason Road site in Green Valley, Solano County, California. Three borings were made at or near two of the cone penetration test soundings. The soils are mostly clayey with a few sandy layers or lenses. Fine-grained soils range from low plasticity sandy lean clay to very plastic fat clay. Lack of stratigraphic correlation in the subsurface prevented us from determining whether any channels had been offset at this site. Because the soils are generally very clayey and few sand layers or lenses are loose, the liquefaction potential at the site is very low.

  6. Cone Penetration Testing, a new approach to quantify coastal-deltaic land subsidence by peat consolidation

    NASA Astrophysics Data System (ADS)

    Koster, Kay; Erkens, Gilles; Zwanenburg, Cor

    2016-04-01

    It is undisputed that land subsidence threatens coastal-deltaic lowlands all over the world. Any loss of elevation (on top of sea level rise) increases flood risk in these lowlands, and differential subsidence may cause damage to infrastructure and constructions. Many of these settings embed substantial amounts of peat, which is, due to its mechanically weak organic composition, one of the main drivers of subsidence. Peat is very susceptible to volume reduction by loading and drainage induced consolidation, which dissipates pore water, resulting in a tighter packing of the organic components. Often, the current state of consolidation of peat embedded within coastal-deltaic subsidence hotspots (e.g. Venice lagoon, Mississippi delta, San Joaquin delta, Kalimantan peatlands), is somewhere between its initial (natural) and maximum compressed stage. Quantifying the current state regarding peat volume loss, is of utmost importance to predict potential (near) future subsidence when draining or loading an area. The processes of subsidence often afflict large areas (>103 km2), thus demanding large datasets to assess the current state of the subsurface. In contrast to data describing the vertical motions of the actual surface (geodesy, satellite imagery), subsurface information applicable for subsidence analysis are often lacking in subsiding deltas. This calls for new initiatives to bridge that gap. Here we introduce Cone Penetration Testing (CPT) to quantify the amount of volume loss peat layers embedded within the Holland coastal plain (the Netherlands) experienced. CPT measures soil mechanical strength, and hundreds of thousands of CPTs are conducted each year on all continents. We analyzed 28 coupled CPT-borehole observations, and found strong empirical relations between volume loss and increased peat mechanical strength. The peat lost between ~20 - 95% of its initial thickness by dissipation of excess pore water. An increase in 0.1 - 0.4 MPa of peat strength is

  7. Applications of the Electronic Cone Penetration Test for the Geotechnical Site Investigation of Florida Soils

    DTIC Science & Technology

    1989-09-30

    SITE + + + ALFa X X X ALFb ** FMYER OOO C1 SCNOO 0 0 0 SGAR AA A SGARb # SGARc Figure 3-2. Cone Resistance Data for Local Variability Study ~ 300 0...Garage ( SGAR ) CO06A CO06B 1.4 West Palm Beach (WPBa) C015A C015C 8.4 West Palm Beach (WPBb) C015B C015C 11.2 West Palm Beach (WPBc) C017B CO17A 7.9... SGAR # # WPBa YYY WPBb ZZZ WPBc Figure 6-1. Cone Resistance Data for Size Comparability Study 600 CU -500- 5 400 V 300 #~Z Z z 200 Z Z Y Z 0- CD

  8. The cone penetration test and 2D imaging resistivity as tools to simulate the distribution of hydrocarbons in soil

    NASA Astrophysics Data System (ADS)

    Pérez-Corona, M.; García, J. A.; Taller, G.; Polgár, D.; Bustos, E.; Plank, Z.

    2016-02-01

    The purpose of geophysical electrical surveys is to determine the subsurface resistivity distribution by making measurements on the ground surface. From these measurements, the true resistivity of the subsurface can be estimated. The ground resistivity is related to various geological parameters, such as the mineral and fluid content, porosity and degree of water saturation in the rock. Electrical resistivity surveys have been used for many decades in hydrogeological, mining and geotechnical investigations. More recently, they have been used for environmental surveys. To obtain a more accurate subsurface model than is possible with a simple 1-D model, a more complex model must be used. In a 2-D model, the resistivity values are allowed to vary in one horizontal direction (usually referred to as the x direction) but are assumed to be constant in the other horizontal (the y) direction. A more realistic model would be a fully 3-D model where the resistivity values are allowed to change in all three directions. In this research, a simulation of the cone penetration test and 2D imaging resistivity are used as tools to simulate the distribution of hydrocarbons in soil.

  9. Cone Penetration Test and Soil Boring at the Bayside Groundwater Project Site in San Lorenzo, Alameda County, California

    USGS Publications Warehouse

    Bennett, Michael J.; Sneed, Michelle; Noce, Thomas E.; Tinsley, John C.

    2009-01-01

    were drilled at the BGP for the purpose of monitoring pore-fluid pressure changes and aquifer-system deformation. One 308-m deep borehole contains six piezometers, the other two boreholes are 182 and 299 m deep and contain a dual-stage extensometer. To investigate the physical properties of the sediments, two phases of subsurface exploration were conducted. In the first phase, a USGS drilling crew obtained numerous core samples, 5.8 cm in diameter by 1.5 m long. The samples were extracted between July 28, 2006, and August 5, 2006; nine samples were tested for this study at the USGS soils laboratory in Menlo Park, California. Phase two began on June 22, 2006, when a seismic cone penetration test (SCPT) sounding was made to a depth of 32.3 m. Additional field work was completed May 8, 2007, with a hollow-stem auger boring that took continuous 9.8-cm-diameter samples from the depth interval of 6.1 to 10.7 m to supplement poor recovery from the first phase of sampling. These samples were also tested in the soils laboratory at the USGS.

  10. Validation of impact penetrometer data by cone penetration testing and shallow seismic data within the regional geology of the Southern North Sea

    NASA Astrophysics Data System (ADS)

    Stephan, Sebastian; Kaul, Norbert; Villinger, Heinrich

    2015-06-01

    This study presents the assessment of total cone resistance from in situ deceleration measurements using the Lance Insertion Retardation meter (LIRmeter) in the Southern North Sea. The penetrometer is equipped with a measurement lance that is up to 6 m in length. The aim was to validate LIRmeter data interpretation within the regional geological context by comparison with static velocity cone penetration testing (CPT) and sub-bottom profiles. In total, 13 datasets were taken, in addition to preexisting hydroacoustical and static velocity CPT datasets. The dynamically acquired data were processed and compared to the reference static velocity data. The validation encourages the use of acceleration-based dynamic penetration tests, since a high degree of agreement was demonstrated between independently acquired dynamic and static cone resistance data. Moreover, the results reveal evidence of two successive formations with different geotechnical properties, consistent with existing knowledge on the regional setting. Additionally, there is novel indication of an incised glacial valley with muddy low-permeability sediments extending much further than reported to date, which would necessitate updating of older maps. The main advantage of penetrometer-based deceleration measurements lies in the robustness of the method, and the reliability of the sensors. However, penetration depth is, for dimensioning reasons, limited to the order of a few meters. Additionally, data processing includes the dependency of knowledge about the soil type to correct the dynamic data. These limitations can be satisfactorily outweighed by combination with reference data from static velocity tests, as demonstrated by integrating these data into a soil classification scheme.

  11. Task summary for cone penetrating testing sounding and soil and groundwater sampling Salmon Site, Lamar County, Mississippi

    SciTech Connect

    Not Available

    1994-10-01

    The Salmon Site (SS), located in Mississippi, was the site of two nuclear and two gas explosion testes conducted deep underground in the Tatum Salt Dome between 1964 and 1970. As a consequence radionuclides generated during the testing were released into the salt dome. During reentry drilling and other site activities, incidental liquid and solid wastes that contained radioactivity were generated, resulting in some soil, ground water and equipment contamination. US DOE is conducting a series of investigations as a part of the Remedial Investigation and Feasibility Study (under CERCLA) This report summarizes the cone penetrometer testing (CPT) and sampling program conducted in fall 1993, providing a description of the activities and a discussion of the results. The objectives of the CPT program were to determine subsurface conditions and stratification; determine the depth to the potentiometric surface; obtain soil samples from predetermined depths; obtain groundwater samples at predetermined depths.

  12. Characterization of subsoil heterogeneity, estimation of grain size distribution and hydraulic conductivity at the Krauthausen test site using Cone Penetration Test.

    PubMed

    Tillmann, A; Englert, A; Nyari, Z; Fejes, I; Vanderborght, J; Vereecken, H

    2008-01-07

    A Cone Penetration Test (CPT) survey with a high spatial resolution was performed in order to investigate the stratigraphy as well as the spatial variability of various soil properties of the Krauthausen test site. Analyses of the CPT measurements showed the subsurface to be dominated by a planar layered structure. Variogram analysis of the various CPT parameters disclosed that within each layer the soil properties have an anisotropic spatial correlation structure. A correlation analysis of the measured CPT data and co-located grain size distributions from soil samples was performed. Since the correlation coefficients were greater equal to 0.7, a reliable empirical relationship between the data sets could be developed. Based on this empirical relationship grain size distributions were estimated at CPT locations. The statistical processing of estimated and measured grain size distributions with respect to their spatial correlation structure disclosed good agreement between the data sets. The estimated grain size distributions from CPT data were used to estimate the hydraulic conductivity in the aquifer. The results provide detailed information of the spatial heterogeneity of the hydraulic conductivity at Krauthausen test site. The validation of these results, using a prior investigation of hydraulic conductivity statistics, suggests the CPT a fast and inexpensive tool for the estimation of three dimensional hydraulic conductivity fields with sufficient accuracy.

  13. Experimental study of penetration-cavity expansion soil bioturbation models using miniature cone penetrometers

    NASA Astrophysics Data System (ADS)

    Ruiz, Siul; Or, Dani; Schymanski, Stan

    2015-04-01

    A recently developed model of soil penetration mechanics and energetics by earthworms and plant roots is based on analogy with cone penetration and cavity expansion. Model predicted resistive forces for different geometries were tested using miniature cone penetrometers at sizes compatible with burrowing earthworms and growing roots. Experiments using cones of different radii (1.0 to 2.5 mm) and different semi-apex angles (15-300) were conducted using an apparatus enabling insertion at constant (prescribed) rates while obtaining highly resolved penetration resistance force measurements. Penetration experiments used soils at different water contents where soil mechanical parameters were determined independently using Oedometer tests under confined and unconfined conditions. Measurements were compared with predictions by analytical expressions for earthworm or root burrowing mechanics. Model predictions for the insertion force as a function of cone geometry and soil mechanical properties were in excellent agreement with cone penetration measurements. The study provides the necessary experimental confirmation to support energetic estimates of bioturbation costs in terms of soil organic carbon consumption. The study provides a better understanding of the fundamental duality nature between penetration forces and stresses and the dependency on cone angle. The measurements suggest that friction plays a relatively minor role as confirmed by experiments using recessed cones (no soil-shaft friction). Differences in application of the model to plant roots and earthworms will be discussed.

  14. INFLUENCE OF CONSOLIDATION CHARACTERISTICS ON CONE PENETRATION RESISTANCE AND LIQUEFACTION RESISTANCE IN SILTY SOILS

    NASA Astrophysics Data System (ADS)

    Ecemis, N.; Thevanayagam, S.

    2009-12-01

    A unique correlation between liquefaction resistance and penetration resistance is not possible to justify without considering the effects of hydraulic conductivity, k, compressibility, mv, and coefficient of consolidation, ch on cone penetration resistance (Thevanayagam and Martin 2002). Therefore, CPT liquefaction screening chart revised to take into account the consolidation characteristics on penetration resistance. Recently, it has been observed that k and ch magnitudes vary between sand and sand-silt mixtures even evaluated at the same liquefaction resistance. The combined effects of penetration rate, v, cone diameter, d, and ch also influences the cone penetration resistance. Silt content affects the liquefaction resistance as well. Several numerical simulations performed by Thevanayagam and Ecemis in 2008 to explore the transition from undrained to drained conditions by varying the non-dimensional parameter T(=vd/ch) with a range of coefficient of consolidation for a single soil type, Ottawa sand-silt mix. Numerical simulation suggested the drained and undrained limits for T are respectively around 0.01 and 10. Tests on circular foundations reported by Finnie and Randolph (1994) suggested the limits of 0.01 and 30. Tests with a cylindrical T-bar penetrometer suggested narrower limits of 0.1 and 10 (House et al. 2001). Finally, the correlation between T, normalized cone resistance and cyclic resistance to liquefaction is proposed and compared with the current liquefaction screening method by CPT (Fig.1). Fig.1: Proposed & Current Liquefaction Screening Method

  15. Evaluation of offshore penetration tests at El Palito refinery, Venezuela

    SciTech Connect

    Rodriguez, J.I.; Simone, A.; Tichatscheck, C.; Boggess, R.

    1995-12-01

    Data from an offshore study in the western part of Venezuela are presented in terms of the penetration test data and liquefaction evaluation. Two types of penetration test were performed (SPT and DCPT) and the results of each are compared. This was made possible by the comparison testing performed at two different locations where the separation between boreholes with different penetration tests was small enough to allow direct comparison of the results. To the authors` knowledge, this is the first time that dynamic cone measurements have been made in an offshore environment. Comments in relation to the evaluation of liquefaction resistance based on the results of the offshore penetration testing are made.

  16. Measuring fuel contamination using high speed gas chromatography and cone penetration techniques

    SciTech Connect

    Farrington, S.P.; Bratton, W.L.; Akard, M.L.

    1995-10-01

    Decision processes during characterization and cleanup of hazardous waste sites are greatly retarded by the turnaround time and expense incurred through the use of conventional sampling and laboratory analyses. Furthermore, conventional soil and groundwater sampling procedures present many opportunities for loss of volatile organic compounds (VOC) by exposing sample media to the atmosphere during transfers between and among sampling devices and containers. While on-site analysis by conventional gas chromatography can reduce analytical turnaround time, time-consuming sample preparation procedures are still often required, and the potential for loss of VOC is not reduced. This report describes the development of a high speed gas chromatography and cone penetration testing system which can detect and measure subsurface fuel contamination in situ during the cone penetration process.

  17. Cone Penetrometer N Factor Determination Testing Results

    SciTech Connect

    Follett, Jordan R.

    2014-03-05

    This document contains the results of testing activities to determine the empirical 'N Factor' for the cone penetrometer in kaolin clay simulant. The N Factor is used to releate resistance measurements taken with the cone penetrometer to shear strength.

  18. Penetration Testing of the OPRA Regolith Penetrator

    NASA Astrophysics Data System (ADS)

    El Shafie, A.; Kegege, O.; Barrows, S.; Roe, L.; Ulrich, R.

    2008-03-01

    Our work focuses on the mechanical design and penetration forces for the Optical Probe for Regolith Analysis. This is a spike-shaped probe delivered to a planet, asteroid, or cometary body by a lander to provide IR spectroscopy of the subsurface.

  19. Fragment Penetration Tests of Armor

    DTIC Science & Technology

    1983-03-15

    Identify by block numbhr) Provides techniques for evaluating armor resistance to attack by HE projectile fragments. Includes static detonations of shell...DISTRIBUTION D. REFERENCES * . . . ........ . ........... D-1 1. SCOPE. This TOP describes the available techniques for testing armor for resistance to attack by...Projectiles Against Armor Plates ("Yankee Stadium" Test-). 4.1.1 hCjective. The objective is to determine the resistance to penetration of various armor

  20. Network Penetration Testing and Research

    NASA Technical Reports Server (NTRS)

    Murphy, Brandon F.

    2013-01-01

    This paper will focus the on research and testing done on penetrating a network for security purposes. This research will provide the IT security office new methods of attacks across and against a company's network as well as introduce them to new platforms and software that can be used to better assist with protecting against such attacks. Throughout this paper testing and research has been done on two different Linux based operating systems, for attacking and compromising a Windows based host computer. Backtrack 5 and BlackBuntu (Linux based penetration testing operating systems) are two different "attacker'' computers that will attempt to plant viruses and or NASA USRP - Internship Final Report exploits on a host Windows 7 operating system, as well as try to retrieve information from the host. On each Linux OS (Backtrack 5 and BlackBuntu) there is penetration testing software which provides the necessary tools to create exploits that can compromise a windows system as well as other operating systems. This paper will focus on two main methods of deploying exploits 1 onto a host computer in order to retrieve information from a compromised system. One method of deployment for an exploit that was tested is known as a "social engineering" exploit. This type of method requires interaction from unsuspecting user. With this user interaction, a deployed exploit may allow a malicious user to gain access to the unsuspecting user's computer as well as the network that such computer is connected to. Due to more advance security setting and antivirus protection and detection, this method is easily identified and defended against. The second method of exploit deployment is the method mainly focused upon within this paper. This method required extensive research on the best way to compromise a security enabled protected network. Once a network has been compromised, then any and all devices connected to such network has the potential to be compromised as well. With a compromised

  1. Universal penetration test apparatus with fluid penetration sensor

    DOEpatents

    Johnson, P.W.; Stampfer, J.F.; Bradley, O.D.

    1999-02-02

    A universal penetration test apparatus is described for measuring resistance of a material to a challenge fluid. The apparatus includes a pad saturated with the challenge fluid. The apparatus includes a compression assembly for compressing the material between the pad and a compression member. The apparatus also includes a sensor mechanism for automatically detecting when the challenge fluid penetrates the material. 23 figs.

  2. Universal penetration test apparatus with fluid penetration sensor

    DOEpatents

    Johnson, Phillip W.; Stampfer, Joseph F.; Bradley, Orvil D.

    1999-01-01

    A universal penetration test apparatus for measuring resistance of a material to a challenge fluid. The apparatus includes a pad saturated with the challenge fluid. The apparatus includes a compression assembly for compressing the material between the pad and a compression member. The apparatus also includes a sensor mechanism for automatically detecting when the challenge fluid penetrates the material.

  3. Scoria Cone and Tuff Ring Stratigraphy Interpreted from Ground Penetrating Radar, Rattlesnake Crater, Arizona

    NASA Astrophysics Data System (ADS)

    Kruse, S. E.; McNiff, C. M.; Marshall, A. M.; Courtland, L. M.; Connor, C.; Charbonnier, S. J.; Abdollahzadeh, M.; Connor, L.; Farrell, A. K.; Harburger, A.; Kiflu, H. G.; Malservisi, R.; Njoroge, M.; Nushart, N.; Richardson, J. A.; Rookey, K.

    2013-12-01

    Numerous recent studies have demonstrated that detailed investigation of scoria cone and maar morphology can reveal rich details the eruptive and erosion histories of these volcanoes. A suite of geophysical surveys were conducted to images Rattlesnake Crater in the San Francisco Volcanic Field, AZ, US. We report here the results of ~3.4 km of ground penetrating radar (GPR) surveys that target the processes of deposition and erosion on the pair of cinder cones that overprint the southeast edge of Rattlesnake crater and on the tuff ring that forms the crater rim. Data were collected with 500, 250, 100, and 50 MHz antennas. The profiles were run in a radial direction down the northeast flanks of the cones (~1 km diameter, ~120 meters height) , and on the inner and outer margins of the oblong maar rim (~20-80 meters height). A maximum depth of penetration of GPR signal of ~15m was achieved high on the flanks of scoria cones. A minimum depth of essentially zero penetration occurred in the central crater. We speculate that maximum penetration occurs near the peaks of the cones and crater rim because ongoing erosion limits new soil formation. Soil formation would tend to increase surface conductivity and hence decrease GPR penetration. Soil is probably better developed within the crater, precluding significant radar penetration there. On the northeast side of the gently flattened rim of the easternmost scoria cone, the GPR profile shows internal layering that dips ~20 degrees northeast relative to the current ground surface. This clearly indicates that the current gently dipping surface is not a stratigraphic horizon, but reflects instead an erosive surface into cone strata that formed close to the angle of repose. Along much of the cone flanks GPR profiles show strata dipping ~4-5 degrees more steeply than the current surface, suggesting erosion has occurred over most of the height of the cone. An abrupt change in strata attitude is observed at the gradual slope

  4. In-place HEPA filter penetration test

    SciTech Connect

    Bergman, W.; Wilson, K.; Elliott, J.

    1997-08-01

    We have demonstrated the feasibility of conducting penetration tests on high efficiency particulate air (HEPA) filters as installed in nuclear ventilation systems. The in-place penetration test, which is designed to yield equivalent penetration measurements as the standard DOP efficiency test, is based on measuring the aerosol penetration of the filter installation as a function of particle size using a portable laser particle counter. This in-place penetration test is compared to the current in-place leak test using light scattering photometers for single HEPA filter installations and for HEPA filter plenums using the shroud method. Test results show the in-place penetration test is more sensitive than the in-place leak test, has a similar operating procedure, but takes longer to conduct. Additional tests are required to confirm that the in-place penetration test yields identical results as the standard dioctyl phthalate (DOP) penetration test for HEPA filters with controlled leaks in the filter and gasket and duct by-pass leaks. Further development of the procedure is also required to reduce the test time before the in-place penetration test is practical. 14 refs., 14 figs., 3 tabs.

  5. Cone penetrometer acceptance test report

    SciTech Connect

    Boechler, G.N.

    1996-09-19

    This Acceptance Test Report (ATR) documents the results of acceptance test procedure WHC-SD-WM-ATR-151. Included in this report is a summary of the tests, the results and issues, the signature and sign- off ATP pages, and a summarized table of the specification vs. ATP section that satisfied the specification.

  6. Into the Cone: A Ground Penetrating Radar Investigation of Near Vent Processes at Cerro Negro Volcano

    NASA Astrophysics Data System (ADS)

    Courtland, L. M.; Kruse, S. E.; Connor, C.

    2009-12-01

    Cinder cones are often assumed to grow via Strombolian activity as described by McGetchin et al (1974). Data with which to evaluate this and other models has historically been collected via eyewitness accounts, photography of eruptions, and mapping of exposed deposits. However, the dangerous nature of eruptions often prohibits near vent observations and accessible deposits are rare. Therefore, in order to gain a better understanding of near vent processes which may be used in volcanic modeling and hazard assessment, new data collection techniques must be implemented. Ground penetrating radar (GPR) imaging of tephra can reveal details of deposits at depths of approximately 2-20+ meters. Data collected in the fall of 2007 is here used to investigate the near vent processes of Cerro Negro, an active basaltic cinder cone in Nicaragua. Each of three GPR profiles begins at the crater rim and continues down the cone to the tephra blanket. One transect follows the prevailing wind direction (SW) while the other two head off at angles to the first: one to the NW and one to the SSW. The data display evidence of cone steepening over time, patterns of ballistic and tephra dispersal, and faulting within the cone, among other features.

  7. Water depth penetration film test

    NASA Technical Reports Server (NTRS)

    Lockwood, H. E.; Perry, L.; Sauer, G. E.; Lamar, N. T.

    1974-01-01

    As part of the National Aeronautics and Space Administration Earth Resources Program, a comparative and controlled evaluation of nine film-filter combinations was completed to establish the relative effectiveness in recording water subsurface detail if exposed from an aerial platform over a typical water body. The films tested, with one exception, were those which prior was suggested had potential. These included an experimental 2-layer positive color film, a 2-layer (minus blue layer) film, a normal 3-layer color film, a panchromatic black-and-white film, and a black-and-white infrared film. Selective filtration was used with all films.

  8. Hydroburst test of a carbon-carbon involute exit cone

    NASA Technical Reports Server (NTRS)

    Sullivan, Roy M.

    1986-01-01

    A hydroburst test of the aft portion of the PAM-D exit cone and the test procedure are described in detail. The hydrostatic pressure required to buckle the cone was 9.75 psi. Meanwhile, the PAM-D exit cone was modeled using the finite element method and a theoretical bucking pressure (8.76 psi) was predicted using the SPAR finite element code. The modeling technique employed is discussed. By comparing the theoretical to predicted critical pressures, this report verifies the modeling technique and calculates a material knockdown factor for the carbon-carbon exit cone.

  9. Non-Linear finite element analysis of cone penetration in layered sandy loam soil-considering precompression stress state

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Axisymmetric finite element (FE) method was developed using a commercial computer program to simulate cone penetration process in layered granular soil. Soil was considered as a non-linear elastic plastic material which was modeled using variable elastic parameters of Young’s Modulus and Poisson’s r...

  10. Engineering and Design: Standard Penetration Test

    DTIC Science & Technology

    2007-11-02

    Penetration TestDe Contract Number Grant Number Program Element Number Author(s) Project Number Task Number Work Unit Number Performing Organization Name...jsfi I I US* of drlXXi~ mucl -r*ueusiog In I Decrm8e8 hcrea8ea Zither Increases Increases Increeses Decrea8es lncreeaes Increases Increeaes Zither &creases DecrU8e* nem8*s hcruses Xnt-ses tieee Utber k~ee Enclosure 2

  11. Where can cone penetrometer technology be applied? Development of a map of Europe regarding the soil penetrability.

    PubMed

    Fleischer, Matthias; van Ree, Derk; Leven, Carsten

    2014-01-01

    Over the past decades, significant efforts have been invested in the development of push-in technology for site characterization and monitoring for geotechnical and environmental purposes and have especially been undertaken in the Netherlands and Germany. These technologies provide the opportunity for faster, cheaper, and collection of more reliable subsurface data. However, to maximize the technology both from a development and implementation point of view, it is necessary to have an overview of the areas suitable for the application of this type of technology. Such an overview is missing and cannot simply be read from existing maps and material. This paper describes the development of a map showing the feasibility or applicability of Direct Push/Cone Penetrometer Technology (DPT/CPT) in Europe which depends on the subsurface and its extremely varying properties throughout Europe. Subsurface penetrability is dependent on a range of factors that have not been mapped directly or can easily be inferred from existing databases, especially the maximum depth reachable would be of interest. Among others, it mainly depends on the geology, the soil mechanical properties, the type of equipment used as well as soil-forming processes. This study starts by looking at different geological databases available at the European scale. Next, a scheme has been developed linking geological properties mapped to geotechnical properties to determine basic penetrability categories. From this, a map of soil penetrability is developed and presented. Validating the output by performing field tests was beyond the scope of this study, but for the country of the Netherlands, this map has been compared against a database containing actual cone penetrometer depth data to look for possible contradictory results that would negate the approach. The map for the largest part of Europe clearly shows that there is a much wider potential for the application of Direct Push Technology than is currently

  12. Asbestos penetration test system for clothing materials

    SciTech Connect

    Bradley, O.D.; Stampfer, J.F.; Sandoval, A.N.; Heath, C.A.; Cooper, M.H.

    1997-04-01

    For hazardous work such as asbestos abatement, there is a need to assess protective clothing fabrics and seam constructions to assure an adequate barrier against hazardous material. The penetration of aerosols through fabrics usually is measured by challenging fabric samples with an aerosol stream at a constant specified airflow. To produce the specified airflow, pressure differentials across the samples often are higher than exist in a work environment. This higher airflow results in higher aerosol velocities through the fabric and, possibly, measured penetration values not representative of those actually experienced in the field. The objective of the reported work was to develop a test method that does not require these higher airflows. The authors have designed and fabricated a new system that tests fabric samples under a low, constant, specified pressure differential across the samples. This differential is adjustable from tenths of a mm Water Gauge (hundredths of an in WG) to over 25-mm WG (1-in WG). The system operates at a pressure slightly lower than its surroundings. Although designed primarily for asbestos, the system is equally applicable to the testing of other aerosols by changing the aerosol generator and detector. Through simple modification of the sample holders, the test apparatus would be capable of evaluating seam and closure constructions.

  13. Severe accident testing of electrical penetration assemblies

    SciTech Connect

    Clauss, D.B. )

    1989-11-01

    This report describes the results of tests conducted on three different designs of full-size electrical penetration assemblies (EPAs) that are used in the containment buildings of nuclear power plants. The objective of the tests was to evaluate the behavior of the EPAs under simulated severe accident conditions using steam at elevated temperature and pressure. Leakage, temperature, and cable insulation resistance were monitored throughout the tests. Nuclear-qualified EPAs were produced from D. G. O'Brien, Westinghouse, and Conax. Severe-accident-sequence analysis was used to generate the severe accident conditions (SAC) for a large dry pressurized-water reactor (PWR), a boiling-water reactor (BWR) Mark I drywell, and a BWR Mark III wetwell. Based on a survey conducted by Sandia, each EPA was matched with the severe accident conditions for a specific reactor type. This included the type of containment that a particular EPA design was used in most frequently. Thus, the D. G. O'Brien EPA was chosen for the PWR SAC test, the Westinghouse was chosen for the Mark III test, and the Conax was chosen for the Mark I test. The EPAs were radiation and thermal aged to simulate the effects of a 40-year service life and loss-of-coolant accident (LOCA) before the SAC tests were conducted. The design, test preparations, conduct of the severe accident test, experimental results, posttest observations, and conclusions about the integrity and electrical performance of each EPA tested in this program are described in this report. In general, the leak integrity of the EPAs tested in this program was not compromised by severe accident loads. However, there was significant degradation in the insulation resistance of the cables, which could affect the electrical performance of equipment and devices inside containment at some point during the progression of a severe accident. 10 refs., 165 figs., 16 tabs.

  14. Operational Based Vision Assessment Cone Contrast Test: Description and Operation

    DTIC Science & Technology

    2016-06-02

    test for identifying and classifying protanomalous and deuteranomalous (red/ green ) color deficient individuals. 15. SUBJECT TERMS Color vision...protanomalous and deuteranomalous (red/ green ) color deficient individuals. 2.0 PURPOSE/BACKGROUND The Operational Based Vision Assessment cone contrast...clearly demonstrated that observed colors on the Rabin CCT change dramatically with head movement . These changes will, of course, invalidate the test

  15. Cone Penetrometer Load Cell Temperature and Radiation Testing Results

    SciTech Connect

    Follett, Jordan R.

    2013-08-28

    This report summarizes testing activities performed at the Pacific Northwest National Laboratory to verify the cone penetrometer load cell can withstand the tank conditions present in 241-AN-101 and 241-AN-106. The tests demonstrated the load cell device will operate under the elevated temperature and radiation levels expected to be encountered during tank farm deployment of the device.

  16. Fire Resistance Testing of Bulkhead and Deck Penetrations. Phase 2

    DTIC Science & Technology

    1988-12-01

    thick steel plate. All sample 12 construction was representative of Class A-0 construction. The UL staff secured insulation ( rockwool batts) to the...designated side of the steel plates and penetrants for testing as Class A-60 deck assemblies. The rockwool batts complied with the Class A-60...insulated with rockwool batts and tested for a Class A-60 rating. This group consisted of one steel penetration, eight copper penetrations, four PVC

  17. Miniature penetrator (MinPen) acceleration recorder development test

    SciTech Connect

    Franco, R.J.; Platzbecker, M.R.

    1998-08-01

    The Telemetry Technology Development Department at Sandia National Laboratories actively develops and tests acceleration recorders for penetrating weapons. This new acceleration recorder (MinPen) utilizes a microprocessor-based architecture for operational flexibility while maintaining electronics and packaging techniques developed over years of penetrator testing. MinPen has been demonstrated to function in shock environments up to 20,000 Gs. The MinPen instrumentation development has resulted in a rugged, versatile, miniature acceleration recorder and is a valuable tool for penetrator testing in a wide range of applications.

  18. Violent Strombolian or not? Using ground-penetrating radar to distinguish deposits of low- and high-energy scoria cone eruptions

    NASA Astrophysics Data System (ADS)

    Courtland, Leah; Kruse, Sarah; Connor, Charles

    2013-12-01

    Scoria cones often grow by the accumulation of individual particles transported ballistically in Strombolian-type eruptions. Alternative models of cone formation suggest that cones are built primarily of fallout from the eruption column in more explosive eruptions, often termed violent Strombolian. Currently, the distinction between normal Strombolian and violent Strombolian is based on direct observations of eruptions or by inference of eruption characteristics from mapping of tephra fall deposits. Unfortunately, medial to distal tephra fall deposits erode rapidly, leaving behind only the near-vent facies of scoria cones which are thicker and less easily eroded. Therefore, a tool that is capable of delineating differences between low-energy Strombolian deposits and higher energy violent Strombolian deposits from investigation of the preserved scoria edifice is necessary. Ground-penetrating radar imaging of Cerro Negro, an active basaltic scoria cone in Nicaragua, has revealed details of cone deposits at depths of up to 12 m. The record of the 1992 eruption, which was observed to be violent Strombolian, shows quantifiable differences from normal Strombolian near-vent facies, including reflections in the downwind profile that are continuous for hundreds of meters and through the slope break. The ability to differentiate between tephra fallout and ballistically emplaced deposits at Cerro Negro suggests ground-penetrating radar imaging may be useful in distinguishing eruptive style in older scoria cones, where the medial to distal tephra deposits are eroded or buried.

  19. Development and testing of a Europa Penetrator for Astrobiology

    NASA Astrophysics Data System (ADS)

    Vijendran, S.; Perkinson, M.-C.; Waugh, L.; Ratcliffe, A.; Kennedy, T.; Church, P.; Fielding, J.; Taylor, N.

    2014-04-01

    Two phases of Penetrator development activities have been funded by ESA. The first phase focussed on the mission and system definition of a penetrator and delivery system for a mission to Europa and the second phase provided an update of the penetrator design for a larger suite of instruments focused on astrobiology and the demonstration of key system technologies through a programme of small scale and full scale testing. The science focus for the Europa penetrator is Astrobiology while the key science goals can be achieved within the first day of operation but a longer lifetime is required for the transmission of the science data to the orbiter. The extreme temperature environment of the Europan surface drove the design to a solution of a Penetrator with two separate bays. The front bay will be a short lifetime bay which will sample the surface and complete all analysis and data transfer within 10 hours. The rear bay is a warm bay which will house EPSC Abstracts Vol. 9, EPSC2014-642, 2014 European Planetary Science Congress 2014 c Author(s) 2014 EPSC European Planetary Science Congress the penetrator support systems required to transmit all collected data to the orbiter. The scientific instruments housed by the penetrator includeds a optical microimager, a habitability package and a mass spectrometer. A drilling and sampling mechanism is used for accessing the icy material outside the Penetrator for analysis. Small scale trails have been undertaken at the University of Cambridge Cavendish Laboratory to validate the impact modelling techniques and the robustness of critical components. A range of trials have been carried out to assess survivability of key elements of the design, including the sampling mechanism, potting compounds, accelerometers, shell, batteries and Torlon suspension springs. Full scale trials have been carried out to test the overall structural integrity of the system and the penetration profile. This programme was carried out in June 2013 at the

  20. Results of the mole penetration tests in different materials

    NASA Astrophysics Data System (ADS)

    Wawrzaszek, Roman; Seweryn, Karol; Grygorczuk, Jerzy; Banaszkiewicz, Marek; Rybus, Tomasz; Wisniewski, Lukasz; Neal, Clive R.; Huang, Shaopeng

    2010-05-01

    Mole devices are low velocity, medium to high energy, self-driven penetrators, designed as a carrier of different sensors for in situ investigations of subsurface layers of planetary bodies. The maximum insertion depth of such devices is limited by energy of single mole's stroke and soil resistance for the dynamic penetration. A mole penetrator ‘KRET' has been designed, developed, and successfully tested at Space Research Centre PAS in Poland. The principle of operation of the mole bases on the interaction between three masses: the cylindrical casing, the hammer, and the rest of the mass, acting as a support mass. This approach takes advantage of the MUPUS penetrator (a payload of Philae lander on Rosetta mission) insertion tests knowledge. Main parameters of the mole KRET are listed below: - outer diameter: 20.4mm, - length: 330mm, - total mass: 488g, - energy of the driving spring: 2.2J, - average power consumption: 0.28W, - average insertion progress/stroke: 8.5mm, The present works of Space Research Center PAS team are focused on three different activities. First one includes investigations of the mole penetration effectiveness in the lunar analogues (supported by ESA PECS project). Second activity, supported by Polish national fund, is connected with numerical calculation of the heat flow investigations and designing and developing the Heat Flow Probe Hardware Component (HPHC) for L-GIP NASA project. It's worth noting that L-GIP project refers to ILN activity. Last activity focuses on preparing the second version of the mole ready to work in low thermal and pressure conditions. Progress of a mole penetrator in granular medium depends on the mechanical properties of this medium. The mole penetrator ‘KRET' was tested in different materials: dry quartz sand (0.3 - 0.8 grain size), wet quartz sand, wheat flour and lunar regolith mechanical simulant - Chemically Enhanced OB-1 (CHENOBI). Wheat flour was selected due to its high cohesion rate and small grain size

  1. Depth of penetration achieved by instrumented seabed penetrators during initial systems demonstration tests

    SciTech Connect

    Calloway, T.M.

    1984-02-01

    Two versions of a gun-launched Instrumented Seabed Penetrator (ISP-1 and ISP-2) were tested in the Gulf of Mexico in May 1982. In each case the gun was loaded with propellant and a penetrator, lowered to the seabed, then fired. ISP-1 traveled 28 m into the seabed, and ISP-2 traveled 36 m. ISP-1 determined its displacement from the gun by means of an on-board accelerometer and microprocessor; after coming to rest, it used an Explosive Acoustic Telemetry System to transmit this information. ISP-2 was connected to the gun with a wire rope which unspooled during flight, allowing the instrumentation package to be retrieved. The measured deceleration profiles from the instrumentation's data memory were then processed off-line to compute the speed and displacement of ISP-2 as a function of time. 14 references, 5 figures, 4 tables.

  2. Testing the reliability of ice-cream cone model

    NASA Astrophysics Data System (ADS)

    Pan, Zonghao; Shen, Chenglong; Wang, Chuanbing; Liu, Kai; Xue, Xianghui; Wang, Yuming; Wang, Shui

    2015-04-01

    Coronal Mass Ejections (CME)'s properties are important to not only the physical scene itself but space-weather prediction. Several models (such as cone model, GCS model, and so on) have been raised to get rid of the projection effects within the properties observed by spacecraft. According to SOHO/ LASCO observations, we obtain the 'real' 3D parameters of all the FFHCMEs (front-side full halo Coronal Mass Ejections) within the 24th solar cycle till July 2012, by the ice-cream cone model. Considering that the method to obtain 3D parameters from the CME observations by multi-satellite and multi-angle has higher accuracy, we use the GCS model to obtain the real propagation parameters of these CMEs in 3D space and compare the results with which by ice-cream cone model. Then we could discuss the reliability of the ice-cream cone model.

  3. Testing the reliability of ice-cream cone model

    NASA Astrophysics Data System (ADS)

    Pan, Z.; Shen, C.; Wang, Y.; Liu, K.

    2013-12-01

    Coronal Mass Ejections (CME)'s properties are important to not only the physical scene itself but spaceweather prediction. Several models(such as cone model, GCS model, and so on) have been raised to get rid of the projection effects within the properties observated by spacecraft. According to SOHO/ LASCO observations, we obtain the 'real' 3D parameters of 33 FFHCMEs (front-side full halo Coronal Mass Ejections) within the 24th solar cycle by the ice-cream cone model. Considering that the method to obtain 3D parameters from the CME observations by multi-satellite and multi-angle has higher accuracy, we use the GCS model to obtain the real propagation parameters of these CMEs in 3D space and compare the results with which by ice-cream cone model. It was demonstrated that the correlation coefficient for the speeds by using these both methods is 0.97.

  4. Three-dimensional analysis of a developing sinkhole using GPR and dynamic cone penetrometer (DCP) testing

    NASA Astrophysics Data System (ADS)

    Brook, Martin; Gaines, Andrew; Nobes, David

    2016-04-01

    Ground penetrating radar (GPR) imaging is one of the most promising non-destructive and non-invasive methods that have offered new opportunities for mapping shallow subsurface disturbances in urbanized and industrialized zones. However, difficulties often arise in choosing the optimum antenna frequency to image subsurface features. While high frequency antennas may provide lots of detail, lower frequency antennas may provide information on larger-scale features that provide more site context. In this study, we performed GPR surveys to investigate a zone of subtle surface subsidence and pavement cracking on reclaimed land at a quayside. A 3-stage approach was used, and included: (1) a 250 MHz antenna survey to delineate the spatial extent of the area of interest; (2) a 500 MHz antenna survey to yield greater detail; and (3) direct verification of some of the key features using dynamic cone penetrometer (DCP) testing to "ground-truth" anomalies. This staged approach proved successful in imaging the sub-grade, and minor voids within approximately 2 m depth. Moreover, the quality of the data can be further improved by using GPR-Slice software in conjunction with DCP data to develop a 3D ground model. Through this approach, a combination of GPR survey and direct testing, we demonstrate the efficiency and quality of this method in mapping shallow subsidence features. An interpretation of the process-origin of the collapse feature is also proposed.

  5. Prediction of coning phenomena for irregular particles in paddle dissolution test.

    PubMed

    Higuchi, Mizuki; Nishida, Shunki; Yoshihashi, Yasuo; Tarada, Katsuhide; Sugano, Kiyohiko

    2015-08-30

    The purpose of the present study was to investigate the applicability of the Zwietering equation to predict the occurrence of coning phenomena for non-spherical, porous, and swell-able particles in the paddle dissolution test. For non-spherical particles, the minimum rotation speed at which the coning phenomena disappear (no coning rpm, NCrpm) was appropriately predicted by using the Stokes diameter or the short side length of the particles. For porous and swell-able particles, NCrpm was appropriately predicted by using the Stokes density of the particles. The accuracy of the Zwietering equation was sufficient to be used for development of a dissolution test method.

  6. Field Testing the STRATA Ground Penetrating Radar for Mars

    NASA Astrophysics Data System (ADS)

    Williams, K. K.; Grant, J. A.; Leuschen, C. J.; Schutz, A. E.

    2005-12-01

    With the MARSIS and SHARAD orbital radar sounders now in operation at and in transit to Mars, respectively, radar investigation of the deep structure of Mars down to several kilometers is underway. By contrast, optical and thermal instruments both in orbit and on the surface have provided information about the top several millimeters and the Mars Exploration Rovers have dug to several cm with their wheels. Nevertheless, little is known about the shallow subsurface of Mars to depths of meters except at locations where continuation of outcrop into the subsurface can be extrapolated. As the methods for exploring Mars evolve, the utility of ground penetrating radar (GPR) for investigating the shallow subsurface of that planet is being considered. GPR has been used for several decades on Earth as a non-invasive tool for studying subsurface structures and stratigraphy for applications in geology, engineering, and archaeology. The STRATA GPR for Mars has been developed as an adaptable, low power, compact, rover-mounted instrument capable of penetrating 10-20 m to reveal subsurface information. Field-testing of this instrument has taken place in volcanic, cratered, permafrost, and deltaic settings, and data collected at 400 MHz possess vertical resolutions of a few cm, sufficient to interpret the subsurface geologic setting. Results from the permafrost environment showed detection of buried massive ground ice as well as the base of the active layer. GPR analysis of this ice distribution was confirmed by resistivity measurements. The fine vertical resolution and good penetration in a variety of geologic settings show that the STRATA instrument provides data quality indistinguishable from commercial systems used on Earth. Most recently, the STRATA instrument has been tested in aeolian and filled crater environments. Data were collected over a sand dune overlying a basalt lava flow near St. Anthony, ID, and at the Campo del Cielo impact crater field in Chaco Province

  7. Test Re-Test Reliability of Four Versions of the 3-Cone Test in Non-Athletic Men

    PubMed Central

    Langley, Jason G.; Chetlin, Robert D.

    2017-01-01

    Until recently, measurement and evaluation in sport science, especially agility testing, has not always included key elements of proper test construction. Often tests are published without reporting reliability and validity analysis for a specific population. The purpose of the present study was to examine the test re-test reliability of four versions of the 3-Cone Test (3CT), and provide guidance on proper test construction for testing agility in athletic populations. Forty male students enrolled in classes in the Department of Physical Education at a mid-Atlantic university participated. On each of test day participants performed 10 trials. In random order, they performed three trials to the right (3CTR, standard test), three to the left (3CTL), and two modified trials (3CTAR and 3CTAL), which included a reactive component in which a visual cue was given to indicate direction. Intra-class correlation coefficients (ICC) indicated a moderate to high reliability for the four tests, 3CTR 0.79 (0.64-0.88, 95%CI), 3CTL 0.73 (0.55-0.85), 3CTAR 0.85(0.74-0.92), and 3CTAL 0.79 (0.64-0.88). Small standard error of the measurement (SEM) was found; range 0.09 to 0.10. Pearson correlations between tests were high (0.82-0.92) on day one as well as day two (0.72-0.85). These results indicate each version of the 3-Cone Test is reliable; however, further tests are needed with specific athletic populations. Only the 3CTAR and 3CTAL are tests of agility due to the inclusion of a reactive component. Future studies examining agility testing and training should incorporate technological elements, including automated timing systems and motion capture analysis. Such instrumentation will allow for optimal design of tests that simulate sport-specific game conditions. Key points The commonly used 3-cone test (upside down “L” to the right”) is a reliable change of direction speed (CODS) test when evaluating collegiate males. A modification of the CODS 3-cone test (upside down

  8. Penetration tests to study the mechanical tribological properties of chisel type knife

    NASA Astrophysics Data System (ADS)

    Vlăduţoiu, L.; Chişiu, G.; Andrei, T.; Predescu, A.; Muraru, C.; Vlăduţ, V.

    2017-02-01

    The goal of this study was to analyze the behaviour of chisel knife type penetration in a certain type of sand. A series of penetration tests were carried out with chisel knife type, the answer to penetration depending mainly on nature, shape, size of knife and operating parameters such as speed, depth and working conditions. Tests were conducted in work conditions with wet sand and dry sand and determined force of resistance to penetration of the chisel knife type to a certain depth.

  9. Low Velocity Earth-Penetration Test and Analysis

    NASA Technical Reports Server (NTRS)

    Fasanella, Edwin L.; Jones, Yvonne; Knight, Norman F., Jr.; Kellas, Sotiris

    2001-01-01

    Modeling and simulation of structural impacts into soil continue to challenge analysts to develop accurate material models and detailed analytical simulations to predict the soil penetration event. This paper discusses finite element modeling of a series of penetrometer drop tests into soft clay. Parametric studies are performed with penetrometers of varying diameters, masses, and impact speeds to a maximum of 45 m/s. Parameters influencing the simulation such as the contact penalty factor and the material model representing the soil are also studied. An empirical relationship between key parameters is developed and is shown to correlate experimental and analytical results quite well. The results provide preliminary design guidelines for Earth impact that may be useful for future space exploration sample return missions.

  10. Testing techniques and comparisons between theory and test for vibration modes of ring stiffened truncated-cone shells.

    NASA Technical Reports Server (NTRS)

    Naumann, E. C.

    1972-01-01

    Vibration tests were carried out on truncated-cone shells with widely spaced ring stiffeners. The models were excited by an air shaker for LF modes and by small electrodynamic shakers for HF modes. The Novozhilov thin shell theory according to which a ring is an assembly of an arbitrary number of segments, each being a short truncated-cone shell of uniform thickness, is used in the analysis of the results. A mobile, noncontacting, displacement-sensitive sensor system developed by the author was used in the tests. Tests results are given for a free-free 60-deg cone and for a clamped-free 60-deg cone. The tests are characterized as having considerable value for the classification of prevalent multimode responses in shells of this type.

  11. Low Force Penetration of Icy Regolith

    NASA Technical Reports Server (NTRS)

    Mantovani, J. G.; Galloway, G. M.; Zacny, K.

    2016-01-01

    A percussive cone penetrometer measures the strength of granular material by using percussion to deliver mechanical energy into the material. A percussive cone penetrometer was used in this study to penetrate a regolith ice mixture by breaking up ice and decompacting the regolith. As compared to a static cone penetrometer, percussion allows low reaction forces to push a penetrometer probe tip more easily into dry regolith in a low gravity environment from a planetary surface rover or a landed spacecraft. A percussive cone penetrates icy regolith at ice concentrations that a static cone cannot penetrate. In this study, the percussive penetrator was able to penetrate material under 65 N of down-force which could not be penetrated using a static cone under full body weight. This paper discusses using a percussive cone penetrometer to discern changes in the concentration of water-ice in a mixture of lunar regolith simulant and ice to a depth of one meter. The rate of penetration was found to be a function of the ice content and was not significantly affected by the down-force. The test results demonstrate that this method may be ideal for a small platform in a reduced gravity environment. However, there are some cases where the system may not be able to penetrate the icy regolith, and there is some risk of the probe tip becoming stuck so that it cannot be retracted. It is also shown that a percussive cone penetrometer could be used to prospect for water ice in regolith at concentrations as high as 8 by weight.

  12. Modified Truncated Cone Target Hyperthermal Atomic Oxygen Test Results

    NASA Technical Reports Server (NTRS)

    Vaughn, J. A.; Kamenetsky, R. R.; Finckenor, M. M.

    1999-01-01

    The modified truncated cone target is a docking target planned for use on the International Space Station. The current design consists of aluminum treated with a black dye anodize, then crosshairs are laser etched for a silvery color. Samples of the treated aluminum were exposed to laboratory simulation of atomic oxygen and ultraviolet radiation to determine if significant degradation might occur. Durability was evaluated based on the contrast ratio between the black and silvery white areas of the target. Degradation of optical properties appeared to level off after an initial period of exposure to atomic oxygen. The sample that was not alodined according to MIL-C-5541, type 1A, performed better than alodined samples.

  13. Fire Resistance Testing of Bulkhead and Deck Penetrations.

    DTIC Science & Technology

    1985-10-01

    consisted of a steel plate identical to that used in the Class A-0 assembly, but rockwool insulation was applied to the fire side of the steel plate and...penetration samples were then insulated with rockwool batts to form a Class A-60 assembly (Figure 2). Between nine and twenty-eight temperature readings...representative of Class A-O construction. The UL staff secured insulation ( rockwool batts) to the fire side of the steel plates and penetrating items to prepare

  14. Piezo-resistivity electric cone penetration technology investigation of the M-basin at the Savannah River Site, Aiken, South Carolina. Progress report, May 1, 1992--October 31, 1992

    SciTech Connect

    Bowers, B.; Rossabi, J.; Shinn, J.D. II; Bratton, W.L.

    1997-05-01

    This report documents the results of a combined field and laboratory investigation program to: (1) delineate the geologic layering and (2) determine the location of a dense non-aqueous liquid-phase (DNAPL) contaminated plume beneath the M Area Hazardous Waste Management Facility at the Savannah River Plant. During April of 1991, DNAPLs were detected in monitoring well (MSB-3D), located adjacent to the capped M-Area Settling Basin. Solvents in the well consisted mainly of tetrachloroethylene and trichloroethylene, which are also the main solvents found in groundwater in the M Area. In permeable soils, DNAPLs move downward rapidly due to their high density and low viscosity as compared to water. Within the vadose zone, DNAPLs tend to be held by the less permeable clay and silts by capillary force. In the saturated zone, the downward movement is slowed by clays and silts and the DNAPL tends to pool on this layer, then spread laterally. The lateral movement continues until a permeable layer is encountered, which can be a sand lens, fracture or other high conductivity seam. The DNAPL then moves downward, until another low permeability layer is encountered. Applied Research Associates was contracted to conduct a program to: (1) field demonstrate the utility of Cone Penetration Technology to investigate DOE contaminant sites and, (2) conduct a laboratory and field program to evaluate the use of electric resistivity surveys to locate DNAPL contaminated soils. The field program was conducted in the M-Basin and laboratory tests were conducted on samples from the major stratigraphy units as identified in Eddy et. al. Cone Penetration Technology was selected to investigate the M-Basin as it: (1) is minimally invasive, (2) generates minimal waste, (3) is faster and less costly than drilling, (4) provides continuous, detailed in situ characterization data, (5) permits real-time data processing, and (6) can obtain soil, soil gas, and water samples without the need for a boring.

  15. Deciphering Deposits: Using Ground Penetrating Radar and Numerical Modeling to Characterize the Emplacement Mechanisms and Associated Energetics of Scoria Cone Eruption and Construction

    NASA Astrophysics Data System (ADS)

    Courtland, Leah M.

    Our understanding of tephra depositional processes is significantly improved by high-resolution ground-penetrating radar (GPR) data collected at Cerro Negro volcano, Nicaragua. The data reveal three depositional regimes: (1) a near-vent region on the cone itself, where 10 GPR radargrams collected on the western flank show quantifiable differences between facies formed from low energy normal Strombolian and higher energy violent Strombolian processes, indicating imaging of scoria cone deposits may be useful in distinguishing eruptive style in older cones where the proximal to distal tephra blanket has eroded away; (2) a proximal zone in which horizons identified in crosswind profiles collected at distances of 700 and 1,000 m from the vent exhibit Gaussian distributions with a high degree of statistical confidence, with tephra thickness decreasing exponentially downwind from the cone base (350 m) to ~ 1,200 m from the vent, and where particles fall from a height of less than ~2 km; and (3) a medial zone, in which particles fall from ~4 to 7 km and the deposit is thicker than expected based on thinning trends observed in the proximal zone of the deposit, indicating a transition from sedimentation dominated by fallout from plume margins to that dominated by fallout from the buoyant eruption cloud. Horizons identified in a crosswind profile at 1600 m from vent exhibit Gaussian distributions, again with high degrees of statistical confidence. True diffusion coefficients are calculated from Gaussian fits of crosswind profiles and do not show any statistical variation between zones (2) and (3). Data display thinning trends that agree with the morphology predicted by the advection-diffusion equation to a high degree of statistical confidence, validating the use of this class of models in tephra forecasting. One such model, the Tephra2 model, is reformulated for student use. A strategy is presented for utilizing this research-caliber model to introduce university

  16. Static penetration resistance of soils

    NASA Technical Reports Server (NTRS)

    Durgunoglu, H. T.; Mitchell, J. K.

    1973-01-01

    Model test results were used to define the failure mechanism associated with the static penetration resistance of cohesionless and low-cohesion soils. Knowledge of this mechanism has permitted the development of a new analytical method for calculating the ultimate penetration resistance which explicitly accounts for penetrometer base apex angle and roughness, soil friction angle, and the ratio of penetration depth to base width. Curves relating the bearing capacity factors to the soil friction angle are presented for failure in general shear. Strength parameters and penetrometer interaction properties of a fine sand were determined and used as the basis for prediction of the penetration resistance encountered by wedge, cone, and flat-ended penetrometers of different surface roughness using the proposed analytical method. Because of the close agreement between predicted values and values measured in laboratory tests, it appears possible to deduce in-situ soil strength parameters and their variation with depth from the results of static penetration tests.

  17. Test Re-Test Reliability of Four Versions of the 3-Cone Test in Non-Athletic Men.

    PubMed

    Langley, Jason G; Chetlin, Robert D

    2017-03-01

    Until recently, measurement and evaluation in sport science, especially agility testing, has not always included key elements of proper test construction. Often tests are published without reporting reliability and validity analysis for a specific population. The purpose of the present study was to examine the test re-test reliability of four versions of the 3-Cone Test (3CT), and provide guidance on proper test construction for testing agility in athletic populations. Forty male students enrolled in classes in the Department of Physical Education at a mid-Atlantic university participated. On each of test day participants performed 10 trials. In random order, they performed three trials to the right (3CTR, standard test), three to the left (3CTL), and two modified trials (3CTAR and 3CTAL), which included a reactive component in which a visual cue was given to indicate direction. Intra-class correlation coefficients (ICC) indicated a moderate to high reliability for the four tests, 3CTR 0.79 (0.64-0.88, 95%CI), 3CTL 0.73 (0.55-0.85), 3CTAR 0.85(0.74-0.92), and 3CTAL 0.79 (0.64-0.88). Small standard error of the measurement (SEM) was found; range 0.09 to 0.10. Pearson correlations between tests were high (0.82-0.92) on day one as well as day two (0.72-0.85). These results indicate each version of the 3-Cone Test is reliable; however, further tests are needed with specific athletic populations. Only the 3CTAR and 3CTAL are tests of agility due to the inclusion of a reactive component. Future studies examining agility testing and training should incorporate technological elements, including automated timing systems and motion capture analysis. Such instrumentation will allow for optimal design of tests that simulate sport-specific game conditions.

  18. Rods affect S-cone discrimination on the Farnsworth-Munsell 100-hue test.

    PubMed

    Knight, R; Buck, S L; Fowler, G A; Nguyen, A

    1998-11-01

    Rod influence on hue discrimination was assessed by the Farnsworth-Munsell 100-hue test. Rod influence was taken as the difference in error scores obtained after complete dark adaptation and during the cone plateau at three mesopic (23, 9, 3 td) and one standard (158 td) light level. On the FM 100, rods produced a differential discrimination loss along a tritan axis as compared with a red-green axis without any bias toward a rod confusion axis. Rods appear to impair discrimination mediated by S-cone pathways, which at moderate levels of illumination can differentially elevate tritan errors on the FM 100.

  19. 49 CFR Appendix E to Part 178 - Flame Penetration Resistance Test

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Flame Penetration Resistance Test E Appendix E to Part 178 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS... PACKAGINGS Pt. 178, App. E Appendix E to Part 178—Flame Penetration Resistance Test (a) Criteria...

  20. 49 CFR Appendix E to Part 178 - Flame Penetration Resistance Test

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Flame Penetration Resistance Test E Appendix E to Part 178 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS.... 178, App. E Appendix E to Part 178—Flame Penetration Resistance Test (a) Criteria for Acceptance....

  1. 49 CFR Appendix E to Part 178 - Flame Penetration Resistance Test

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Flame Penetration Resistance Test E Appendix E to Part 178 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS.... 178, App. E Appendix E to Part 178—Flame Penetration Resistance Test (a) Criteria for Acceptance....

  2. 49 CFR Appendix E to Part 178 - Flame Penetration Resistance Test

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Flame Penetration Resistance Test E Appendix E to Part 178 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS.... 178, App. E Appendix E to Part 178—Flame Penetration Resistance Test (a) Criteria for Acceptance....

  3. 49 CFR Appendix E to Part 178 - Flame Penetration Resistance Test

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Flame Penetration Resistance Test E Appendix E to Part 178 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS.... 178, App. E Appendix E to Part 178—Flame Penetration Resistance Test (a) Criteria for Acceptance....

  4. Correlations Between Shear Wave Velocity and In-Situ Penetration Test Results for Korean Soil Deposits

    NASA Astrophysics Data System (ADS)

    Sun, Chang-Guk; Cho, Chang-Soo; Son, Minkyung; Shin, Jin Soo

    2013-03-01

    Shear wave velocity ( V S) can be obtained using seismic tests, and is viewed as a fundamental geotechnical characteristic for seismic design and seismic performance evaluation in the field of earthquake engineering. To apply conventional geotechnical site investigation techniques to geotechnical earthquake engineering, standard penetration tests (SPT) and piezocone penetration tests (CPTu) were undertaken together with a variety of borehole seismic tests for a range of sites in Korea. Statistical modeling of the in-situ testing data identified correlations between V S and geotechnical in-situ penetration data, such as blow counts ( N value) from SPT and CPTu data including tip resistance ( q t), sleeve friction ( f s), and pore pressure ratio ( B q). Despite the difference in strain levels between conventional geotechnical penetration tests and borehole seismic tests, it is shown that the suggested correlations in this study is applicable to the preliminary determination of V S for soil deposits.

  5. Development of Cone Wedge Ring Expansion Test to Evaluate Mechanical Properties of Clad Tubing Structure

    SciTech Connect

    Wang, Jy-An John

    2016-10-01

    To determine the hoop tensile properties of irradiated fuel cladding in a hot cell, a cone wedge ring expansion test method was developed. A four-piece wedge insert was designed with tapered angles matched to the cone shape of a loading piston. The ring specimen was expanded in the radial direction by the lateral expansion of the wedges under the downward movement of the piston. The advantages of the proposed method are that implementation of the test setup in a hot cell is simple and easy, and that it enables a direct strain measurement of the test specimen from the piston’s vertical displacement soon after the wedge-clad contact resistance is initiated.

  6. Multispectral analysis and cone signal modelling of pseudoisochromatic test plates

    NASA Astrophysics Data System (ADS)

    Luse, K.; Ozolinsh, M.; Fomins, S.; Gutmane, A.

    2013-12-01

    The aim of the study is to determine the consistency of the desired colour reproduction of the stimuli using calibrated printing technology available to anyone (EpsonStylus Pro 7800 printer was). 24 colour vision assessment plates created in the University of Latvia were analysed right after their fabrication on august 2012 and after intense use for 7 months (colour vision screening on 700 people). Multispectral imagery results indicate that the alignment of the samples after seven months of use has maintained on the CIExy confusion lines of deutan deficiency type, but the shift towards achromatic area in the diagram indicate decrease in the total colour difference (ΔE*ab) of test background (achromatic) areas and stimuli (chromatic) areas, thus affecting the testing outcome and deficiency severity level classification ability of the plates.

  7. Initial basalt target site selection evaluation for the Mars penetrator drop test

    NASA Technical Reports Server (NTRS)

    Bunch, T. E.; Quaide, W. L.; Polkowski, G.

    1976-01-01

    Potential basalt target sites for an air drop penetrator test were described and the criteria involved in site selection were discussed. A summary of the background field geology and recommendations for optimum sites are also presented.

  8. Long rod penetration test of hot isostatically pressed Ti-based targets

    NASA Astrophysics Data System (ADS)

    Nesterenko, Vitali F.; Indrakanti, Sastry S.; Brar, Singh; Gu, YaBei

    2000-04-01

    Hot Isostatic Pressing (HIP) is one of the most efficient techniques to produce high quality materials from powders. Nevertheless there is a shortage of data on high-strain-rate behavior and penetration resistance of such materials. In this paper the results of penetration test with tungsten (93%) heavy alloy penetrators of solid and porous composite samples of Ti-6Al-4V alloy with different microstructures (Widmanstatten pattern and equiaxed) are presented. Penetration depth for HIPed materials is smaller than in baseline samples of Ti-6Al-4V alloy (forged rod MIL-T-9047G). Composite materials with alumina rods and tubes filled with B4C powders demonstrated a new features of penetration: projectile deflection with self sealing of hole and forced shear localization caused by tubes fracture. The results demonstrate the applicability of HIPing for Ti-based armor materials.

  9. A new penetration test method: protection efficiency of glove and clothing materials against diphenylmethane diisocyanate (MDI).

    PubMed

    Henriks-Eckerman, Maj-Len; Mäkelä, Erja

    2015-03-01

    Reported cases of allergic contact dermatitis caused by methylenediphenyl diisocyanate (MDI) have increased and thereby increased the need for adequate skin protection. Current standardized permeation and penetration test methods give information about efficacy of protective materials against individual components of the polyurethane systems. They do not give information of what kind of clothing materials workers should wear against splashes when handling mixed MDI-polyurethane formulations, which contain MDI, its oligomers, and polyols. The aim of this study was to develop and validate a sensitive penetration test method that can be used to select clothing that is protective enough against uncured splashes of MDI-polyurethane, still easy to use, and also, to find affordable glove materials that provide adequate protection during a short contact. The penetration of MDI through eight representative glove or clothing materials was studied with the developed test procedure. One MDI hardener and two polymeric MDI (PMDI)-polyol formulations representing different curing times were used as test substances. The materials tested included work clothing (woven) fabric, arm shields (nonwoven fabric), old T-shirt, winter gloves, and gloves of nitrile rubber, leather, vinyl (PVC), and natural rubber. A drop (50 µl) of test substance was added to the outer surface of the glove/clothing material, which had Tape Fixomull attached to the inner surface as a collection medium. After penetration times of 5 or 20min, the collecting material was removed and immediately immersed into acetonitrile containing 1-(2-methoxyphenyl)-piperazine for derivatization. The formed urea derivatives of 2,4'-MDI and 4,4'-MDI were analysed using liquid chromatography with mass spectrometric and UV detection. The precision of the test method was good for the material with high penetration (work clothing fabric) of MDI, as the relative standard deviation (RSD) was 14 and 20%. For the arm shield with a low

  10. Validity and cost-effectiveness of cone adaptation test as a screening tool to detect retinitis pigmentosa

    PubMed Central

    Deshpande, Rahul; Save, Prajakta; Deshpande, Madan; Shegunashi, Mahadev; Chougule, Marium; Khandekar, Rajiv

    2016-01-01

    Background: The cone adaptation test is to detect retinitis pigmentosa (RP) cases confirmed by electroretinogram (ERG). We present the validity and cost-effectiveness of cone adaptation test as a screening tool for detecting RP. Methods: This cross-sectional study was conducted between November 2013 and December 2013. All RP cases diagnosed by ophthalmologists of H. V. Desai Eye Hospital in the last 5 years were participated in this study. The cone adaptation test was done in photopic and scotopic illumination. Failed test means 10 s or more to complete the test under scotopic illumination. A technician who was masked for cone adaptation test finding carried out ERG. Demographics, symptoms, and history of treatment were inquired. Those with flat ERG wave in scotopic condition and corresponding clinical findings were defined as having RP. Sensitivity, specificity, and false-positive and false-negative parameters of validity were estimated. The unit cost of performing test and ERG was calculated. Results: All 32 RP patients (28 male, age median 23.5 ± 14.5 years) had a vision more than 6/60 and flat wave in ERG under mesopic/scotopic illumination. Thirty-one participants failed cone adaptation test. The sensitivity was 31/32 × 100 = 97%. The specificity was 100%. There was no false-positive case. Consanguinity rate among parents was 43%. The cost of testing one child using “cone adaptation test kit” was 2.5 US $. The unit cost of diagnosing RP using ERG was 10 US $. Conclusion: Cone adaptation is a valid and cost-effective screening tool test for RP. The consanguinity rate among parents of an RP patient was high. PMID:27843226

  11. Calorimeter testing of thermal degradation of multilayer insulation due to the presence of penetrations

    NASA Astrophysics Data System (ADS)

    Johnson, W. L.; Kelly, A. O.; Heckle, K. W.; Jumper, K. M.; Fesmire, J. E.

    2014-01-01

    Cryogenic multilayer insulation (MLI) has been studied thoroughly over the last 60 years. Numerous tank and calorimeter tests have been performed using many different insulation approaches. However, a large majority of these tests have been on ideal or nearly ideal insulation systems. There are several important factors such as seams or penetrations through the insulation that can drive up the heat load on the entire system, for full system design, these factors must be accounted for. Several attempts have been made to identify the performance losses due to structural integration with a real system. These specific cases were tied to specific programs and configuration dependent. In an effort to understand the complex heat transfer mechanisms surrounding such systems, a calorimeter testing program coupled with thermal modeling of the experimental results tests was performed. A new boil-off calorimeter was developed for measurement of the two dimensional heat transfer effects. The corresponding methodology was devised to calculate the thermal losses within the MLI due to the presence of the penetration and determine the affected area within the blanket. The test matrix included multiple integration methods, materials, penetration materials, and penetrations sizes. Results of the testing were used to anchor a thermal model of the system that allows for characterization of a wider range of situations.

  12. Performance Assessment of Hard Rock TBM and Rock Boreability Using Punch Penetration Test

    NASA Astrophysics Data System (ADS)

    Jeong, Ho-Young; Cho, Jung-Woo; Jeon, Seokwon; Rostami, Jamal

    2016-04-01

    Rock indentation tests are often called punch penetration tests and are known to be related to penetration rates of drilling equipment and hard rock tunnel boring machines (TBMs). Various indices determined from analysis of the force-penetration plot generated from indentation tests have been used to represent the drillability, boreability, and brittleness of rocks. However, no standard for the punch penetration test procedure or method for calculating the related indices has been suggested or adopted in the rock mechanics community. This paper introduces new indices based on the punch test to predict the performance of hard rock TBMs. A series of punch tests was performed on rock specimens representing six rock formations in Korea with different dimensions, i.e., the core specimens had different lengths and diameters. Of the indices obtained from the punch tests, the peak load index and mean load index showed good correlations with the cutting forces measured in full-scale linear cutting machine tests on the same rock types. The indices also showed good linear correlations with the ratio of uniaxial strength to Brazilian tensile strength, which indicates the brittleness of rock. The scale effect of using core specimens was investigated, and a preferred dimension for the punch test specimens is proposed. This paper also discusses the results of the punch test and full-scale rock cutting tests using LCM. The results of this study confirm that the proposed indices from the punch tests can be used to provide a reliable prediction of the cutting forces that act on a disc cutter. The estimated cutting forces can then be used for optimization of cutter-head design and performance prediction of hard rock TBMs.

  13. Subsonic wind-tunnel tests of a trailing-cone device for calibrating aircraft static pressure systems

    NASA Technical Reports Server (NTRS)

    Jordan, F. L., Jr.; Ritchie, V. S.

    1973-01-01

    A trailing-cone device for calibrating aircraft static-pressure systems was tested in a transonic wind tunnel to investigate the pressure-sensing characteristics of the device including effects of several configuration changes. The tests were conducted at Mach numbers from 0.30 to 0.95 with Reynolds numbers from (0.9 x one million to 4.1 x one million per foot). The results of these tests indicated that the pressures sensed by the device changed slightly but consistently as the distance between the device pressure orifices and cone was varied from 4 to 10 cone diameters. Differences between such device-indicated pressures and free-stream static pressure were small, however, and corresponded to Mach number differences of less than 0.001 for device configurations with pressure orifices located 5 or 6 cone diameters ahead of the cone. Differences between device-indicated and free-stream static pressures were not greatly influenced by a protection skid at the downstream end of the pressure tube of the device nor by a 2-to-1 change in test Reynolds number.

  14. Ballistic penetration test results for Ductal and ultra-high performance concrete samples.

    SciTech Connect

    Reinhart, William Dodd; Thornhill, Tom Finley, III

    2010-03-01

    This document provides detailed test results of ballistic impact experiments performed on several types of high performance concrete. These tests were performed at the Sandia National Laboratories Shock Thermodynamic Applied Research Facility using a 50 caliber powder gun to study penetration resistance of concrete samples. This document provides test results for ballistic impact experiments performed on two types of concrete samples, (1) Ductal{reg_sign} concrete is a fiber reinforced high performance concrete patented by Lafarge Group and (2) ultra-high performance concrete (UHPC) produced in-house by DoD. These tests were performed as part of a research demonstration project overseen by USACE and ERDC, at the Sandia National Laboratories Shock Thermodynamic Applied Research (STAR) facility. Ballistic penetration tests were performed on a single stage research powder gun of 50 caliber bore using a full metal jacket M33 ball projectile with a nominal velocity of 914 m/s (3000 ft/s). Testing was observed by Beverly DiPaolo from ERDC-GSL. In all, 31 tests were performed to achieve the test objectives which were: (1) recovery of concrete test specimens for post mortem analysis and characterization at outside labs, (2) measurement of projectile impact velocity and post-penetration residual velocity from electronic and radiographic techniques and, (3) high-speed photography of the projectile prior to impact, impact and exit of the rear surface of the concrete construct, and (4) summarize the results.

  15. NASA Ames Laminar Flow Supersonic Wind Tunnel (LFSWT) Tests of a 10 deg Cone at Mach 1.6

    NASA Technical Reports Server (NTRS)

    Wolf, Stephen W. D.; Laub, James A.

    1997-01-01

    This work is part of the ongoing qualification of the NASA Ames Laminar Flow Supersonic Wind Tunnel (LFSWT) as a low-disturbance (quiet) facility suitable for transition research. A 10 deg cone was tested over a range of unit Reynolds numbers (Re = 2.8 to 3.8 million per foot (9.2 to 12.5 million per meter)) and angles of incidence (O deg to 10 deg) at Mach 1.6. The location of boundary layer transition along the cone was measured primarily from surface temperature distributions, with oil flow interferometry and Schlieren flow visualization providing confirmation measurements. With the LFSWT in its normal quiet operating mode, no transition was detected on the cone in the test core, over the Reynolds number range tested at zero incidence and yaw. Increasing the pressure disturbance levels in the LFSWT test section by a factor of five caused transition onset on the cone within the test core, at zero incidence and yaw. When operating the LFSWT in its normal quiet mode, transition could only be detected in the test core when high angles of incidence (greater than 5 deg) for cones were set. Transition due to elevated pressure disturbances (Tollmien-Schlichting) and surface trips produced a skin temperature rise of order 4 F (2.2 C). Transition due to cross flows on the leeward side of the cone at incidence produced a smaller initial temperature rise of only order 2.5 F (1.4 C), which indicates a slower transition process. We can conclude that these cone tests add further proof that the LFSWT test core is normally low-disturbance (pressure fluctuations greater than 0.1%), as found by associated direct flow quality measurements discussed in this report. Furthermore, in a quiet test environment, the skin temperature rise is sensitive to the type of dominant instability causing transition. The testing of a cone in the LFSWT provides an excellent experiment for the development of advanced transition detection techniques.

  16. Protective clothing for pesticide operators: part I--selection of a reference test chemical for penetration testing.

    PubMed

    Shaw, Anugrah; Schiffelbein, Paul

    2016-01-01

    A systematic approach was taken to develop a database for protective clothing for pesticide operators; results are reported as a two-part series. Part I describes the research studies that led to identification of a pesticide formulation that could serve as a reference test chemical for further testing. Measurement of pesticide penetration was conducted using different types of pesticide formulations. Six fabrics were tested using 10 formulations at different concentrations. Three formulations were subsequently selected for further testing. Analysis of the data indicated that, when compared with other formulations, mean percent penetration of 5% Prowl 3.3 EC [emulsifiable concentrate diluted to 5% active ingredient (pendimethalin)] is either similar to or higher than most test chemicals. Those results led to choosing 5% Prowl 3.3 EC as a reference test liquid. Part II of the study, published as a separate paper, includes data on a wide range of textile materials.

  17. ASP (AntiSubmarine Penetrator) base plate redesign and explosive bolt test

    SciTech Connect

    Cole, J.K.; Wolfe, W.P.

    1988-10-01

    This report presents the results of a post-flight investigation of the Rocket Antisubmarine Penetrator (RAP) tests of the AntiSubmarine Penetrator (ASP). It focuses on the cause for the premature deployment of the on-board recovery system and the failure of the base pressure transducers. As a result of the investigation, the base plate of the ASP vehicle was modified to increase its structural stiffness. Also, an instrumented test was conducted to assess the environment that is created when the three explosive bolts are activated to separate the vehicle from the interstage adapter and the rocket booster. The results of this test are presented and discussed. 5 refs., 15 figs.

  18. First laboratory perforating tests in coal show lower-than-expected penetration

    SciTech Connect

    Snider, P.M.; Walton, I.C.; Skinner, T.K.; Atwood, D.C.; Grove, B.M.; Graham, C.

    2008-06-15

    Worldwide Coal Bed Methane (CBM) resources are huge, estimated at 3,000 to 9,000 Tcf. The production rate from CBM reservoirs is low, perhaps 50-100 mcf/day. Various completion methods are being evaluated and new technologies are being developed with the aim of increasing production rates. Considering this interest and activity level, little attention has been paid to the CBM completion fundamentals. Perforating is a critical part of this process, especially considering the PRB development migration from single-coal, open-hole completions into multi-zone, cased-hole completions. This paper describes the first known laboratory-testing program to investigate shaped charge penetration in coal targets. We describe mechanical properties of the coals tested, and penetration results for different shaped charges (of different designs), shot at various stress conditions. CT scan and cutaway imaging of the perforation tunnels are also discussed. Tests were conducted under dry and saturated conditions. The preliminary experiments reported here indicate that shaped charge penetration in coal is significantly less than expected, considering the target's density and strength. The authors provide insight into what may be the reasons for these unexpected results and recommend a path forward for shaped charge testing, designs, predictive tools, and how to optimize CBM completions.

  19. Bolivia-Brazil gas pipeline about to take off; seen as litmus test for Southern Cone gas grid

    SciTech Connect

    1995-08-07

    After more than 4 decades of studies, plans, and shelved projects, the proposed Bolivia-Brazil gas pipeline is finally about to get off the ground. The 3,700 km gas pipeline will require an investment of at least $2 billion and is viewed by many as a litmus test for the developing gas market and energy integration of South America`s Southern Cone countries. Overall, industry officials see eventual emergence of two large integrated gas grids serving South America: one for the northern countries and another for the Southern Cone. This will enable the six countries with gas surplus to their needs to export the surplus to neighboring, gas-short countries. The northern gas-long countries are Venezuela, Colombia, and Trinidad and Tobago; those in the Southern Cone are Argentina, Bolivia, and Peru. The paper discusses financial details, project details, pipeline construction, the Petrobras strategy, Argentine pipeline projects, and other pipeline proposals.

  20. Persistent radiographic cone cuts: a simple test to avoid the frustrating problem.

    PubMed

    Shivanandappa, Santosh Gowdru; Mushannavar, Lata Shankarappa; Katti, Girish

    2014-01-01

    In routine dental radiography, one may encounter numerous radiographic errors, one of which may be partial images or cone cuts. These cones cut errors although may appear as simple problems, but often persistent cone cuts may be frustrating to the dental practitioner. In this study, our main aim was to find and solve the origin of the problem. This study was conducted with two different intraoral X-ray machines with 12 inch length position indicating devices (PIDs) with four No. 2 intraoral films. If the problem is originated in the X-ray machine, it can be solved by either tapping the collimator or by repositioning the PID.

  1. Testing Penetration of Epoxy Resin and Diamine Hardeners through Protective Glove and Clothing Materials.

    PubMed

    Henriks-Eckerman, Maj-Len; Mäkelä, Erja A; Suuronen, Katri

    2015-10-01

    Efficient, comfortable, yet affordable personal protective equipment (PPE) is needed to decrease the high incidence of allergic contact dermatitis arising from epoxy resin systems (ERSs) in industrial countries. The aim of this study was to find affordable, user-friendly glove and clothing materials that provide adequate skin protection against splashes and during the short contact with ERS that often occurs before full cure. We studied the penetration of epoxy resin and diamine hardeners through 12 glove or clothing materials using a newly developed test method. The tests were carried out with two ERS test mixtures that had a high content of epoxy resin and frequently used diamine hardeners of different molar masses. A drop (50 µl) of test mixture was placed on the outer surface of the glove/clothing material, which had a piece of Fixomull tape or Harmony protection sheet attached to the inner surface as the collection medium. The test times were 10 and 30 min. The collecting material was removed after the test was finished and immersed into acetone. The amounts of diglycidyl ether of bisphenol A (DGEBA), isophorone diamine (IPDA), and m-xylylenediamine (XDA) in the acetone solution were determined by gas chromatography with mass spectrometric detection. The limit for acceptable penetration of XDA, IPDA, and DGEBA through glove materials was set at 2 µg cm(-2). Penetration through the glove materials was 1.4 µg cm(-2) or less. The three tested chemical protective gloves showed no detectable penetration (<0.5 µg cm(-2)). Several affordable glove and clothing materials were found to provide adequate protection during short contact with ERS, in the form of, for example, disposable gloves or clothing materials suitable for aprons and as additional protective layers on the most exposed parts of clothing, such as the front of the legs and thighs and under the forearms. Every ERS combination in use should be tested separately to find the best skin protection material

  2. Phylogenetic test of speciation by host shift in leaf cone moths (Caloptilia) feeding on maples (Acer).

    PubMed

    Nakadai, Ryosuke; Kawakita, Atsushi

    2016-07-01

    The traditional explanation for the exceptional diversity of herbivorous insects emphasizes host shift as the major driver of speciation. However, phylogenetic studies have often demonstrated widespread host plant conservatism by insect herbivores, calling into question the prevalence of speciation by host shift to distantly related plants. A limitation of previous phylogenetic studies is that host plants were defined at the family or genus level; thus, it was unclear whether host shifts predominate at a finer taxonomic scale. The lack of a statistical approach to test the hypothesis of host-shift-driven speciation also hindered studies at the species level. Here, we analyze the radiation of leaf cone moths (Caloptilia) associated with maples (Acer) using a newly developed, phylogeny-based method that tests the role of host shift in speciation. This method has the advantage of not requiring complete taxon sampling from an entire radiation. Based on 254 host plant records for 14 Caloptilia species collected at 73 sites in Japan, we show that major dietary changes are more concentrated toward the root of the phylogeny, with host shift playing a minor role in recent speciation. We suggest that there may be other roles for host shift in promoting herbivorous insect diversification rather than facilitating speciation per se.

  3. Geologic Investigations Spurred by Analog Testing at the 7504 Cone-SP Mountain Area of the San Francisco Volcanic Field

    NASA Technical Reports Server (NTRS)

    Eppler, Dean B.

    2015-01-01

    The SP Mountain area of the San Francisco Volcanic Field, AZ, has been used as an analog mission development site for NASA since 1998. This area consists of basaltic cinder cones, lava flows and maar craters that have been active since mid-Miocene, with the youngest events occurring within the last 10,000 years. The area has been used because its geologic and topographic resemblance to lunar and Martian terrains provides an ideal venue for testing hardware and science operations practices that might be employed on planetary surfaces, as well as training astronauts in field geology. Analog operations have often led to insights that spurred new scientific investigations. Most recently, an investigation of the 7504 cone was initiated due to perceptions that Apollo-style traverse plans executed during the Desert RATS 2010 mission had characterized the area incorrectly, leading to concerns that the Apollo traverse planning process was scientifically flawed. This investigation revealed a complex history of fissure eruptions of lava and cinders, cinder cone development, a cone-fill-and-spill episode, extensive rheomorphic lava flow initiation and emplacement, and cone sector collapse that led to a final lava flow. This history was not discernible on pre-RATS mission photogeology, although independent analysis of RATS 2010 data and samples develped a "75% complete solution" that validated the pre-RATS mission planning and Apollo traverse planning and execution. The study also pointed out that the development of scientific knowledge with time in a given field area is not linear, but may follow a functional form that rises steeply in the early period of an investigation but flattens out in the later period, asymptotically approaching a theoretical "complete knowledge" point that probably cannot be achieved. This implies that future human missions must be prepared to shift geographic areas of investigation regularly if significant science returns are to be forthcoming.

  4. Geologic Investigations Spurred by Analog Testing at the 7504 Cone-Sp Mountain Area of the San Francisco Volcanic Field

    NASA Astrophysics Data System (ADS)

    Bleacher, J. E.; Eppler, D. B.; Needham, D. H.; Evans, C. A.; Skinner, J. A.; Feng, W.

    2015-12-01

    The SP Mountain area of the San Francisco Volcanic Field, AZ, has been used as an analog mission development site for NASA since 1998. This area consists of basaltic cinder cones, lava flows and maar craters that have been active since mid-Miocene, with the youngest events occurring within the last 10,000 years. The area has been used because its geologic and topographic resemblance to lunar and Martian terrains provides an ideal venue for testing hardware and science operations practices that might be employed on planetary surfaces, as well as training astronauts in field geology. Analog operations have often led to insights that spurred new scientific investigations. Most recently, an investigation of the 7504 cone was initiated due to perceptions that Apollo-style traverse plans executed during the Desert RATS 2010 mission had characterized the area incorrectly, leading to concerns that the Apollo traverse planning process was scientifically flawed. This investigation revealed a complex history of fissure eruptions of lava and cinders, cinder cone development, a cone-fill-and-spill episode, extensive rheomorphic lava flow initiation and emplacement, and cone sector collapse that led to a final lava flow. This history was not discernible on pre-RATS mission photogeology, although independent analysis of RATS 2010 data and samples develped a "75% complete solution" that validated the pre-RATS mission planning and Apollo traverse planning and execution. The study also pointed out that the development of scientific knowledge with time in a given field area is not linear, but may follow a functional form that rises steeply in the early period of an investigation but flattens out in the later period, asymptotically approaching a theoretical "complete knowledge" point that probably cannot be achieved. This implies that future human missions must be prepared to shift geographic areas of investigation regularly if significant science returns are to be forthcoming.

  5. Development of an in vitro modified skin absorption test for the investigation of the follicular penetration pathway of caffeine.

    PubMed

    Trauer, S; Lademann, J; Knorr, F; Richter, H; Liebsch, M; Rozycki, C; Balizs, G; Büttemeyer, R; Linscheid, M; Patzelt, A

    2010-01-01

    The Organization for Economic Cooperation and Development (OECD) recommends caffeine as a reference substance for in vitro skin absorption tests using Franz diffusion cells (FDC). However, it has not been possible to investigate the follicular penetration pathway using this method until now. The aim of this study was to develop a technique to allow the examination of the follicular penetration pathway of a substance penetrating into the skin. The OECD standard method was therefore combined with the follicle closing technique (FCT), an established in vivo method. By using test skin of varying follicular densities, different penetration values were obtained for the test substance caffeine. The follicular penetration rate was determined by an indirect calculation after modifying the in vivo FCT for use in the in vitro FDC. This method is the first to allow the differentiation of penetration pathways by combining the OECD standard method (using the FDC) and the FCT. Caffeine showed a surprisingly high rate of penetration through the follicular shunts in vitro.

  6. Can the biogenicity of Europa's surfical sulfur be tested simultaneously with penetrators and ion traps?

    NASA Astrophysics Data System (ADS)

    Chela-Flores, J.; Bhattacherjee, A. B.; Dudeja, S.; Kumar, N.; Seckbach, J.

    2009-04-01

    with microbial mats—well understood in the context of the Antarctic dry valley lakes for the expulsion of a large quantity of sulfur—are used in tests on the icy surface of Europa, it is pertinent to evaluate the stopping-depth for the harsh radiation on the Europan surface. Recently, we have estimated the stopping-depth that should be probed by penetrators in proposed missions, such as LAPLACE, or in future projects. We find, in agreement with others (Greenberg, 2005), that beyond a few millimeters a penetrator would be testing biogeochemistry without any interference from radiation effects (Dudeja et al., 2009). Simultaneously with the penetrators there is an alternative suitable technology available. The isotopic S fractionation on the cloud surrounding Europa should reflect to a large extent the same biogenically-driven S fractionation that is taking place on the surface. We should recall that the origin of the cloud is due to particles that have been expelled by hypervelocity impacts of micrometeoroids on the surface. The instrumentation of ion-trap mass spectrometry has already been successfully completed for tests on a comet nucleus (the Ptolemy instrument and the Rosetta space mission). Ion traps have once again been in the planning stages for their eventual application in LAPLACE, or elsewhere (Todd et al., 2006; Taylor et al., 2007). Since the cloud around Europa is constantly being replenished by the above-mentioned micrometeorites, it would be reasonable to expect the cloud to mirror the large S-isotope deviations that may be caused locally by the assumed sulfate-reducing microorganisms. Consequently, dust detectors in orbit around this satellite should record similar large fluctuations of the Luria-Delbrück type that we have conjectured to take place on Europa's icy surface. This possibility has been explained in detail recently (Chela-Flores and Kumar, 2008). Consequently, we argue in favor that the instrumentation to be selected should include

  7. Cold knife cone biopsy

    MedlinePlus

    ... biopsy; Pap smear - cone biopsy; HPV - cone biopsy; Human papilloma virus - cone biopsy; Cervix - cone biopsy; Colposcopy - cone biopsy Images Female reproductive anatomy Cold cone biopsy Cold cone removal References American ...

  8. Analysis of pumping tests: Significance of well diameter, partial penetration, and noise

    USGS Publications Warehouse

    Heidari, M.; Ghiassi, K.; Mehnert, E.

    1999-01-01

    The nonlinear least squares (NLS) method was applied to pumping and recovery aquifer test data in confined and unconfined aquifers with finite diameter and partially penetrating pumping wells, and with partially penetrating piezometers or observation wells. It was demonstrated that noiseless and moderately noisy drawdown data from observation points located less than two saturated thicknesses of the aquifer from the pumping well produced an exact or acceptable set of parameters when the diameter of the pumping well was included in the analysis. The accuracy of the estimated parameters, particularly that of specific storage, decreased with increases in the noise level in the observed drawdown data. With consideration of the well radii, the noiseless drawdown data from the pumping well in an unconfined aquifer produced good estimates of horizontal and vertical hydraulic conductivities and specific yield, but the estimated specific storage was unacceptable. When noisy data from the pumping well were used, an acceptable set of parameters was not obtained. Further experiments with noisy drawdown data in an unconfined aquifer revealed that when the well diameter was included in the analysis, hydraulic conductivity, specific yield and vertical hydraulic conductivity may be estimated rather effectively from piezometers located over a range of distances from the pumping well. Estimation of specific storage became less reliable for piezemeters located at distances greater than the initial saturated thickness of the aquifer. Application of the NLS to field pumping and recovery data from a confined aquifer showed that the estimated parameters from the two tests were in good agreement only when the well diameter was included in the analysis. Without consideration of well radii, the estimated values of hydraulic conductivity from the pumping and recovery tests were off by a factor of four.The nonlinear least squares method was applied to pumping and recovery aquifer test data in

  9. Evaluation of a highway pavement using non destructive tests: Falling Weight Deflectometer and Ground Penetrating Radar

    NASA Astrophysics Data System (ADS)

    Marecos, Vania; Fontul, Simona; de Lurdes Antunes, Maria

    2015-04-01

    This paper presents the results of the application of Falling Weight Deflectometer (FWD) and Ground Penetrating Radar (GPR) to assess the bearing capacity of a rehabilitated flexible highway pavement that began to show the occurrence of cracks in the surface layer, about one year after the improvement works. A visual inspection of the surface of the pavement was performed to identify and characterize the cracks. Several core drills were done to analyse the cracks propagation in depth, these cores were also used for GPR data calibration. From the visual inspection it was concluded that the development of the cracks were top-down and that the cracks were located predominantly in the wheel paths. To determine the thickness of the bituminous and granular layers GPR tests were carried out using two horn antennas of 1,0 GHz and 1,8 GHz and a radar control unit SIR-20, both from GSSI. FWD load tests were performed on the wheel paths and structural models were established, based on the deflections measured, through back calculation. The deformation modulus of the layers was calculated and the bearing capacity of the pavement was determined. Summing up, within this study the GPR was used to continuously detect the layer thickness and the GPR survey data was calibrated with core drills. The results showed variations in the bituminous layer thickness in comparison to project data. From the load tests it was concluded that the deformation modulus of the bituminous layers were also vary variable. Limitations on the pavement bearing capacity were detected in the areas with the lower deformation modulus. This abstract is of interest for COST Action TU1208 Civil Engineering Applications of Ground Penetrating Radar.

  10. Hanford tank initiative cone penetrometer stand alone grouting module

    SciTech Connect

    CALLAWAY, W.S.

    1998-10-15

    The HTI subsurface characterization task will use the Hanford Cone Penetrometer platform (CPP) to deploy contaminant sensor and soil sampling probes into the vadose zone surrounding SST 241-AX-104. Closure of the resulting penetration holes may be stipulated by WAC requirements. A stand alone grouting capability deployable by the CPP has been developed. This qualification test plan defines testing of this capability to be performed at the Immobilized Low Activity Waste Disposal Complex.

  11. Geohydrology of rocks penetrated by test well USW H-4, Yucca Mountain, Nye County, Nevada

    USGS Publications Warehouse

    Whitfield, M.S.; Eshom, E.P.; Thordarson, William; Schaefer, D.H.

    1985-01-01

    Test well USW H-4 is one of several wells drilled in the southwestern part of the Nevada Test Site for hydraulic testing, hydrologic monitoring, and geophysical logging. The work was performed in cooperation with the U.S. Department of Energy. The rocks penetrated by the well to a total depth of 1,219 m were volcanic tuffs of Tertiary age. Hydraulic coefficients calculated from pumping test data indicate that transmissivity ranged from 200 to 790 sq m/day. A radioactive tracer, borehole flow survey indicated that the two most productive zones during this borehole flow survey occurred in the upper part of the Bullfrog Member of the Crater Flat Tuff, depth interval from 721 to 731.5m, and in the underlying part of the Tram Member, depth interval from 864 to 920m. The water is predominantly a sodium biocarbonate type with small concentrations of calcium, magnesium, and sulfate. The apparent age of this composite water sample was determined by carbon-14 date of 17,200 years before present. (USGS)

  12. Use of Ground Penetrating Radar at the FAA's National Airport Pavement Test Facility

    NASA Astrophysics Data System (ADS)

    Injun, Song

    2015-04-01

    The Federal Aviation Administration (FAA) in the United States has used a ground-coupled Ground Penetrating Radar (GPR) at the National Airport Pavement Test Facility (NAPTF) since 2005. One of the primary objectives of the testing at the facility is to provide full-scale pavement response and failure information for use in airplane landing gear design and configuration studies. During the traffic testing at the facility, a GSSI GPR system was used to develop new procedures for monitoring Hot Mix Asphalt (HMA) pavement density changes that is directly related to pavement failure. After reviewing current setups for data acquisition software and procedures for identifying different pavement layers, dielectric constant and pavement thickness were selected as dominant parameters controlling HMA properties provided by GPR. A new methodology showing HMA density changes in terms of dielectric constant variations, called dielectric sweep test, was developed and applied in full-scale pavement test. The dielectric constant changes were successfully monitored with increasing airplane traffic numbers. The changes were compared to pavement performance data (permanent deformation). The measured dielectric constants based on the known HMA thicknesses were also compared with computed dielectric constants using an equation from ASTM D4748-98 Standard Test Method for Determining the Thickness of Bound Pavement Layers Using Short-Pulse Radar. Six inches diameter cylindrical cores were taken after construction and traffic testing for the HMA layer bulk specific gravity. The measured bulk specific gravity was also compared to monitor HMA density changes caused by aircraft traffic conditions. Additionally this presentation will review the applications of the FAA's ground-coupled GPR on embedded rebar identification in concrete pavement, sewer pipes in soil, and gage identifications in 3D plots.

  13. Nuclear Weapon Initiatives: Low-Yield R&D, Advanced Concepts, Earth Penetrators, Test Readiness

    DTIC Science & Technology

    2007-11-02

    weapon-produced collateral effects . The current nuclear weapons stockpile, while possessing some limited ground penetration capability and lower ...RNEP bar use of the weapon? . . . . . . . . . . . . . . . 54 Would RNEP have an adverse effect on nuclear nonproliferation? . . 56 Will Targets Be...73 List of Figures Figure 1. Earth penetration reduces yield needed to destroy buried targets . . . . 45 Figure 2. Lower yield

  14. Automation of Cyber Penetration Testing Using the Detect, Identify, Predict, React Intelligence Automation Model

    DTIC Science & Technology

    2013-09-01

    With increased computing power available, intelligent automation is a clear choice for simplifying the lives of both administrators and developers...with manual cyber penetration [1]. With increased computing power available, intelligent automation is a clear choice for simplifying the lives... power intensive, and basic automation has the limitation of only finding the specific vulnerabilities which it is programmed to find. Penetration

  15. Analysis of partially penetrating slug tests in a stratified formation by alternating piezometer and tube methods

    NASA Astrophysics Data System (ADS)

    Sakata, Yoshitaka; Imai, Toshikazu; Ikeda, Ryuji; Nishigaki, Makoto

    2015-09-01

    In partially penetrating slug tests, hydraulic conductivity (K) estimates might not necessarily be valid because of vertical flows in heterogeneous formations. We assess the error in hypothetical stratified formations by numerical sensitivity analysis, and propose an effective method for compensation by incorporating two types of casing configuration (piezometer and tube). The hypothetical stratified formation consists of completely horizontal layers, each 1 m thick; the permeability is different between, but not within, layers. In this study, conductivity estimates in the piezometer and tube methods are calculated by assigning various patterns of conductivity to the test, upper, and lower layers: KT, KU, and KL. The effect of vertical flow becomes significant when KT is small relative to KU or KL, and KL is more important than KU because the base of the borehole is open to the lower formation. The conductivity ratios (estimate over actual value) are treated as approximately linearly dependent on logarithms of KT/KU and KT/KL, so that conductivity estimates can be straightforwardly derived from one piezometer measurement and two tube measurements at the top and bottom of the screen. The linear relations are evaluated and constant parameters are determined under specific conditions. This study also recommends alternating piezometer and tube methods in the drilling procedure because the actual variation of K with depth is larger than that found using isolated measurements, as shown in a field study of alluvial fan gravel deposits in Sapporo, Japan.

  16. Ground penetrating radar and direct current resistivity evaluation of the desiccation test cap, Savannah River Site

    SciTech Connect

    Wyatt, D.E.; Cumbest, R.J.

    1996-04-01

    The Savannah River Site (SRS) has a variety of waste units that may be temporarily or permanently stabilized by closure using an impermeable cover to prevent groundwater infiltration. The placement of an engineered kaolin clay layer over a waste unit is an accepted and economical technique for providing an impermeable cover but the long term stability and integrity of the clay in non-arid conditions is unknown. A simulated kaolin cap has been constructed at the SRA adjacent to the Burial Ground Complex. The cap is designed to evaluate the effects of desiccation on clay integrity, therefore half of the cap is covered with native soil to prevent drying, while the remainder of the cap is exposed. Measurements of the continuing impermeability of a clay cap are difficult because intrusive techniques may locally compromise the structure. Point measurements made to evaluate clay integrity, such as those from grid sampling or coring and made through a soil cover, may miss cracks, joints or fissures, and may not allow for mapping of the lateral extent of elongate features. Because of these problems, a non-invasive technique is needed to map clay integrity, below a soil or vegetation cover, which is capable of moderate to rapid investigation speeds. Two non-intrusive geophysical techniques, direct current resistivity and ground penetrating radar (GPR), have been successful at the SRS in geologically mapping shallow subsurface clay layers. The applicability of each technique in detecting the clay layer in the desiccation test cap and associated anomalies was investigated.

  17. Standard penetration test-based probabilistic and deterministic assessment of seismic soil liquefaction potential

    USGS Publications Warehouse

    Cetin, K.O.; Seed, R.B.; Der Kiureghian, A.; Tokimatsu, K.; Harder, L.F.; Kayen, R.E.; Moss, R.E.S.

    2004-01-01

    This paper presents'new correlations for assessment of the likelihood of initiation (or triggering) of soil liquefaction. These new correlations eliminate several sources of bias intrinsic to previous, similar correlations, and provide greatly reduced overall uncertainty and variance. Key elements in the development of these new correlations are (1) accumulation of a significantly expanded database of field performance case histories; (2) use of improved knowledge and understanding of factors affecting interpretation of standard penetration test data; (3) incorporation of improved understanding of factors affecting site-specific earthquake ground motions (including directivity effects, site-specific response, etc.); (4) use of improved methods for assessment of in situ cyclic shear stress ratio; (5) screening of field data case histories on a quality/uncertainty basis; and (6) use of high-order probabilistic tools (Bayesian updating). The resulting relationships not only provide greatly reduced uncertainty, they also help to resolve a number of corollary issues that have long been difficult and controversial including: (1) magnitude-correlated duration weighting factors, (2) adjustments for fines content, and (3) corrections for overburden stress. ?? ASCE.

  18. A bayesian approach for determining velocity and uncertainty estimates from seismic cone penetrometer testing or vertical seismic profiling data

    USGS Publications Warehouse

    Pidlisecky, A.; Haines, S.S.

    2011-01-01

    Conventional processing methods for seismic cone penetrometer data present several shortcomings, most notably the absence of a robust velocity model uncertainty estimate. We propose a new seismic cone penetrometer testing (SCPT) data-processing approach that employs Bayesian methods to map measured data errors into quantitative estimates of model uncertainty. We first calculate travel-time differences for all permutations of seismic trace pairs. That is, we cross-correlate each trace at each measurement location with every trace at every other measurement location to determine travel-time differences that are not biased by the choice of any particular reference trace and to thoroughly characterize data error. We calculate a forward operator that accounts for the different ray paths for each measurement location, including refraction at layer boundaries. We then use a Bayesian inversion scheme to obtain the most likely slowness (the reciprocal of velocity) and a distribution of probable slowness values for each model layer. The result is a velocity model that is based on correct ray paths, with uncertainty bounds that are based on the data error. ?? NRC Research Press 2011.

  19. Development of phased array ultrasonic testing in lieu of radiography for testing complete joint penetration (CJP) welds

    NASA Astrophysics Data System (ADS)

    Haldipur, P.; Boone, Shane D.

    2014-04-01

    The past decade has seen new, emerging innovation of Ultrasonic Testing (UT). Specifically, multiple manufacturers have produced Phased Array Ultrasonic Testing (PAUT) systems. The PAUT systems embed a matrix of multiple (some up to 128) single transducers into one probe used for scanning elastic materials. Simultaneously exciting multiple transducers offers distinct advantages; depending on the sequencing of transducer excitation, the ultrasonic beam could be steered within the material and multiple beams help develop extra dimensional data to assist with visualization of possible flaws including the discontinuity size, shape and location. Unfortunately, there has not been broad acceptance of PAUT in the bridge fabrication industry because it is currently not a recognized inspection technology in AWS D1.5. One situation in which the technology would excel would be inspection of Complete Joint Penetration (CJP) butt welds. Currently, AWS D1.5 required CJP welds subjected to tensile or reversal stresses only be inspected by Radiographic Testing (RT). However, discontinuities normally seen by RT can also be seen with PAUT. Until specification language is adopted into D1.5, there will continue to be hesitancy to use PAUT for the inspection of CJP butt welds. Developmental work must first be performed to develop the acceptance criteria and the specification language. The developmental work from the inspections carried out on butt-weld specimens and transition butt-weld specimens are presented in this paper. Specific scan plans were developed using the ES-Beam simulation software for each of the test specimens. In depth analysis of PAUT data obtained to determine exact location and sizing information of the defects was performed. The results also present the comparison of results from PAUT to those obtained using conventional UT and radiography.

  20. Molecular diagnostic tests for ascertainment of genotype at the rod cone dysplasia 1 (rcd1) locus in Irish setters.

    PubMed

    Ray, K; Baldwin, V J; Acland, G M; Aguirre, G D

    1995-03-01

    Rod-cone dysplasia type 1 (rcd1) is one of several canine photoreceptor degenerations, collectively termed progressive retinal atrophy (PRA), that afflict different breeds of dogs. The rcd1 phenotype is an early onset autosomal recessive disease caused by a nonsense amber mutation, at codon 807, in the canine gene for the beta-subunit of rod cyclic GMP phosphodiesterase (canine PDEB). The mutation involves a G to A transition at nucleotide position 2420, which presumably would cause premature termination of the canine PDEB protein by 49 amino acid residues. In both a small pedigree study of Irish setters from the United Kingdom and in larger canine pedigree studies in the United States, this gene defect has been found to be the only mutation causing rcd1. Here we report development of a diagnostic test which unequivocally distinguishes the three genotypes at the rcd1 locus: rcd1/rcd1 (homozygous mutant, affected); rcd1/+ (heterozygous, carrier); and +/+ (homozygous normal, wildtype).

  1. Autosomal dominant retinitis pigmentosa with apparent incomplete penetrance: a clinical, electrophysiological, psychophysical, and molecular genetic study.

    PubMed Central

    Moore, A T; Fitzke, F; Jay, M; Arden, G B; Inglehearn, C F; Keen, T J; Bhattacharya, S S; Bird, A C

    1993-01-01

    Twenty five symptomatic individuals and six asymptomatic obligate gene carriers from four families with autosomal dominant retinitis pigmentosa (adRP) showing apparent incomplete penetrance have been studied. Symptomatic individuals from three families showed early onset of night blindness, non-recordable rod electroretinograms, and marked elevation of both rod and cone thresholds in all subjects tested. In the fourth family, there was more variation in the age of onset of night blindness and some symptomatic individuals showed well preserved rod and cone function in some retinal areas. All asymptomatic individuals tested had evidence of mild abnormalities of rod and cone function, indicating that these families show marked variation in expressivity rather than true non-penetrance of the adRP gene. No mutations of the rhodopsin or RDS genes were found in these families and the precise genetic mutation(s) remain to be identified. PMID:8025041

  2. Geomechanics of penetration :laboratory analog experiments using a modified split hopkinson pressure bar/impact testing procedure.

    SciTech Connect

    Holcomb, David Joseph; Gettemy, Glen L.; Bronowski, David R.

    2005-11-01

    This research continues previous efforts to re-focus the question of penetrability away from the behavior of the penetrator itself and toward understanding the dynamic, possibly strain-rate dependent, behavior of the affected materials. A modified split Hopkinson pressure bar technique is prototyped to determine the value of reproducing the stress states, and mechanical responses, of geomaterials observed in actual penetrator tests within a laboratory setting. Conceptually, this technique simulates the passage of the penetrator surface past any fixed point in the penetrator trajectory by allowing for a controlled stress-time function to be transmitted into a sample, thereby mimicking the 1D radial projection inherent to analyses of the cavity expansion problem. Test results from a suite of weak (unconfined compressive strength, or UCS, of 22 MPa) concrete samples, with incident strain rates of 100-250 s{sup -1}, show that the complex mechanical response includes both plastic and anelastic wave propagation, and is critically dependent on incident particle velocity and saturation state. For instance, examination of the transmitted stress-time data, and post-test volumetric measurements of pulverized material, provide independent estimates of the plasticized zone length (1-2 cm) formed for incident particle velocity of {approx}16.7 m/s. The results also shed light on the elastic or energy propagation property changes that occur in the concrete. For example, the pre- and post-test zero-stress elastic wave propagation velocities show that the Young's modulus drops from {approx}19 GPa to <8 GPa for material within the first centimeter from the plastic transition front, while the Young's modulus of the dynamically confined, axially-stressed (in 6-18 MPa range) plasticized material drops to 0.5-0.6 GPa. The data also suggest that the critical particle velocity for formation of a plastic zone in the weak concrete is 13-15 m/s, with increased saturation tending to increase

  3. A Scalable and Dynamic Testbed for Conducting Penetration-Test Training in a Laboratory Environment

    DTIC Science & Technology

    2015-03-01

    capabilities. C. Support for tactical technologies : a way to incorporate tactical Army networks including wireless sensor networks and mobile ad-hoc networks... security of computer networks. This testbed was generated based on an informal study of the common needs of real-life penetration testers. Only open-source... technologies are used and step-by-step instructions are provided on how to create the testbed. A case study is also included with a sample scenario

  4. The SORA Experiment: Testing the Subsurface Penetration Radar SHARAD on the Earth

    NASA Astrophysics Data System (ADS)

    Flamini, E.; Ori, G.; Seu, R.; Angrilli, F.

    2006-12-01

    Two subsurface penetrating radars are currently working on Mars: MARSIS and SHARAD. MARSIS displays deep penetration and low resolution and SHARAD exhibits low penetration and high resolution. SHARAD is able to depicts relatively detailed internal features and stratal patterns. In order to fully understand the SHARAD capability, the data interpretations, and possible future developments the Italian Space Agency is organising an experiment to fly a SHARAD model in a stratospheric ballon. The experiment will consists in a no-space qualified model of SHARAD installed on a stratospheric balloon flying over the Arctic from the Spitsbergen. The fly will circumnavigate the Arctic passing over Greenland, the Canadian Arctic Arcipelago, New Zelmya and probably Spitsbergen itself. The fly altitude will be 35000 m and the cruise will last about a week. The investigated aareas includes ice sheets, glaciers, permafrost areas, plutonic to sedimentary rocks. And sedimentary natural environments. Sea ice will be probably too thin to be detected by the instrument. Frequency will be chosen to mimic the SAHARD ones. The experiment is planned for June 2007 with backup on September 2007 or June 2008.

  5. Penetration of rod projectiles in semi-infinite targets : a validation test for Eulerian X-FEM in ALEGRA.

    SciTech Connect

    Park, Byoung Yoon; Leavy, Richard Brian; Niederhaus, John Henry J.

    2013-03-01

    The finite-element shock hydrodynamics code ALEGRA has recently been upgraded to include an X-FEM implementation in 2D for simulating impact, sliding, and release between materials in the Eulerian frame. For validation testing purposes, the problem of long-rod penetration in semi-infinite targets is considered in this report, at velocities of 500 to 3000 m/s. We describe testing simulations done using ALEGRA with and without the X-FEM capability, in order to verify its adequacy by showing X-FEM recovers the good results found with the standard ALEGRA formulation. The X-FEM results for depth of penetration differ from previously measured experimental data by less than 2%, and from the standard formulation results by less than 1%. They converge monotonically under mesh refinement at first order. Sensitivities to domain size and rear boundary condition are investigated and shown to be small. Aside from some simulation stability issues, X-FEM is found to produce good results for this classical impact and penetration problem.

  6. Subsonic stability and control flight test results of the Space Shuttle /tail cone off/

    NASA Technical Reports Server (NTRS)

    Cooke, D. R.

    1980-01-01

    The subsonic stability and control testing of the Space Shuttle Orbiter in its two test flights in the tailcone-off configuration is discussed, and test results are presented. Flight test maneuvers were designed to maximize the quality and quantity of stability and control data in the minimal time allotted using the Space Shuttle Functional Simulator and the Modified Maximum Likelihood Estimator (MMLE) programs, and coefficients were determined from standard sensor data sets using the MMLE, despite problems encountered in timing due to the different measurement systems used. Results are included for lateral directional and longitudinal maneuvers as well as the Space Shuttle aerodynamic data base obtained using the results of wind tunnel tests. The flight test data are found to permit greater confidence in the data base since the differences found are well within control system capability. It is suggested that the areas of major differences, including lateral directional data with open speedbrake, roll due to rudder and normal force due to elevon, be investigated in any further subsonic flight testing. Improvements in sensor data and data handling techniques for future orbital test flights are indicated.

  7. Geohydrology of volcanic tuff penetrated by test well UE-25b#1, Yucca Mountain, Nye County, Nevada

    USGS Publications Warehouse

    Lahoud, R.G.; Lobmeyer, D.H.; Whitfield, M.S.

    1984-01-01

    Test well UE-25bNo1, located on the east side of Yucca Mountain in the southwestern part of the Nevada Test Site, was drilled to a total depth of 1,220 meters and hydraulically tested as part of a program to evaluate the suitability of Yucca Mountain as a nuclear-waste repository. The well penetrated almost 46 meters of alluvium and 1,174 meters of Tertiary volcanic tuffs. The composite hydraulic head for aquifers penetrated by the well was 728.9 meters above sea level (471.4 meters below land surface) with a slight decrease in loss of hydraulic head with depth. Average hydraulic conductivities for stratigraphic units determined from pumping tests, borehole-flow surveys, and packer-injection tests ranged from less than 0.001 meter per day for the Tram Member of the Crater Flat Tuff to 1.1 meters per day for the Bullfrog Member of the Crater Flat Tuff. The small values represented matrix permeability of unfractured rock; the large values probably resulted from fracture permeability. Chemical analyses indicated that the water is a soft sodium bicarbonate type, slightly alkaline, with large concentrations of dissolved silica and sulfate. Uncorrected carbon-14 age dates of the water were 14,100 and 13,400 years. (USGS)

  8. Effect of ProTaper and Reciproc preparation and gutta-percha cone on cold lateral compaction

    PubMed Central

    Tanomaru-Filho, Mario; Trindade, Daniela Vilas Boas; de Almeida, Larissa Torres; Espir, Camila Galletti; Bonetti-Filho, Idomeo; Guerreiro-Tanomaru, Juliane Maria

    2016-01-01

    Context: The effectiveness of cold lateral compaction depends on the root canal preparation and used gutta-percha cone. Aims: The aim of this study is to evaluate finger spreader penetration into root canals prepared with ProTaper (PT) or Reciproc (Rec) systems and filled with gutta-percha cones with different tapers. Materials and Methods: Twenty-four simulated root canals in resin blocks with 30° curvature were prepared up to PT F2 or Rec R25. They were divided into four experimental groups according to the master gutta-percha cone and preparation (25.02 or F2/PT, and 25.02 or R25/Rec). Cold lateral compaction was performed using a stainless steel finger spreader size B. The set cone-finger spreader-resin block was placed in a universal test machine, and a load up to 1.5 kg was applied on the finger spreader. The final distance between the finger spreader and apical preparation after load application was obtained. For comparison among the groups, data were submitted to ANOVA and Tukey's tests, with a significance level of 5%. Results: Greater finger spreader penetration was observed for 0.02/Rec and 0.02/PT, followed by F2/PT and R25/Rec. Conclusion: The use of cones associated with PT and Rec preparations does not allow the finger spreader penetration up to the apical third. PMID:27656057

  9. Spectral Analysis of Surface Waves and Standard Penetration Test for Sub-Soil Characterization: A Comparison Study.

    NASA Astrophysics Data System (ADS)

    Villagomez, Jessica

    2016-04-01

    Spectral Analysis of Surface Waves (SASW) is a method used for sub-soil characterization. SASW has the advantage of being non-intrusive and non-invasive. Commonly used in current geotechnical engineering for being faster and cheaper than other laboratory tests. Standard Penetration test (SPT), which is used to obtain stratigraphic profiles of the sub-soil, contrary to SASW test, is invasive, destructive and not less important, expensive. The SASW method uses dispersive characteristics of Rayleigh waves in stratified or half-space media to obtain their physical parameters and henceforward its characterization. From this, a soil profile is estimated. A comparison between a geophysical method, Spectral Analysis of Surface Waves (SASW), and the N-value obtained from a classic geotechnical test (SPT) to estimate and characterize the in-site sub-soil properties at Patillas Dam, Puerto Rico, will be given in this work.

  10. Field drilling tests on improved geothermal unsealed roller-cone bits. Final report

    SciTech Connect

    Hendrickson, R.R.; Jones, A.H.; Winzenried, R.W.; Maish, A.B.

    1980-05-01

    The development and field testing of a 222 mm (8-3/4 inch) unsealed, insert type, medium hard formation, high-temperature bit are described. Increased performance was gained by substituting improved materials in critical bit components. These materials were selected on bases of their high temperature properties, machinability and heat treatment response. Program objectives required that both machining and heat treating could be accomplished with existing rock bit production equipment. Six of the experimental bits were subjected to air drilling at 240/sup 0/C (460/sup 0/F) in Franciscan graywacke at the Geysers (California). Performances compared directly to conventional bits indicate that in-gage drilling time was increased by 70%. All bits at the Geysers are subjected to reaming out-of-gage hole prior to drilling. Under these conditions the experimental bits showed a 30% increase in usable hole drilled, compared with the conventional bits. The materials selected improved roller wear by 200%, friction per wear by 150%, and lug wear by 150%. These tests indicate a potential well cost savings of 4 to 8%. Savings of 12% are considered possible with drilling procedures optimized for the experimental bits.

  11. Model for collisional fast ion diffusion into Tokamak Fusion Test Reactor loss cone

    SciTech Connect

    Chang, C.S. |; Zweben, S.J.; Schivell, J.; Budny, R.; Scott, S.

    1994-08-01

    An analytic model is developed to estimate the classical pitch angle scattering loss of energetic fusion product ions into prompt loss orbits in a tokamak geometry. The result is applied to alpha particles produced by deutrium-tritium fusion reactions in a plasma condition relevant to Tokamak Fusion Test Reactor (TFTR). A poloidal angular distribution of collisional fast ion loss at the first wall is obtained and the numerical result from the TRANSP code is discussed. The present model includes the effect that the prompt loss boundary moves away from the slowing-down path due to reduction in banana thickness, which enables us to understand, for the first time. the dependence of the collisional loss rate on Z{sub eff}.

  12. Suitability of energy cone for probabilistic volcanic hazard assessment: validation tests at Somma-Vesuvius and Campi Flegrei (Italy)

    NASA Astrophysics Data System (ADS)

    Tierz, Pablo; Sandri, Laura; Costa, Antonio; Zaccarelli, Lucia; Di Vito, Mauro Antonio; Sulpizio, Roberto; Marzocchi, Warner

    2016-11-01

    Pyroclastic density currents (PDCs) are gravity-driven hot mixtures of gas and volcanic particles which can propagate at high speed and cover distances up to several tens of kilometers around a given volcano. Therefore, they pose a severe hazard to the surroundings of explosive volcanoes able to produce such phenomena. Despite this threat, probabilistic volcanic hazard assessment (PVHA) of PDCs is still in an early stage of development. PVHA is rooted in the quantification of the large uncertainties (aleatory and epistemic) which characterize volcanic hazard analyses. This quantification typically requires a big dataset of hazard footprints obtained from numerical simulations of the physical process. For PDCs, numerical models range from very sophisticated (not useful for PVHA because of their very long runtimes) to very simple models (criticized because of their highly simplified physics). We present here a systematic and robust validation testing of a simple PDC model, the energy cone (EC), to unravel whether it can be applied to PVHA of PDCs. Using past PDC deposits at Somma-Vesuvius and Campi Flegrei (Italy), we assess the ability of EC to capture the values and variability in some relevant variables for hazard assessment, i.e., area of PDC invasion and maximum runout. In terms of area of invasion, the highest Jaccard coefficients range from 0.33 to 0.86 which indicates an equal or better performance compared to other volcanic mass-flow models. The p values for the observed maximum runouts vary from 0.003 to 0.44. Finally, the frequencies of PDC arrival computed from the EC are similar to those determined from the spatial distribution of past PDC deposits, with high PDC-arrival frequencies over an ˜8-km radius from the crater area at Somma-Vesuvius and around the Astroni crater at Campi Flegrei. The insights derived from our validation tests seem to indicate that the EC is a suitable candidate to compute PVHA of PDCs.

  13. A Highly Sensitive Assay Using Synthetic Blood Containing Test Microbes for Evaluation of the Penetration Resistance of Protective Clothing Material under Applied Pressure.

    PubMed

    Shimasaki, Noriko; Hara, Masayuki; Kikuno, Ritsuko; Shinohara, Katsuaki

    2016-01-01

    To prevent nosocomial infections caused by even either Ebola virus or methicillin-resistant Staphylococcus aureus (MRSA), healthcare workers must wear the appropriate protective clothing which can inhibit contact transmission of these pathogens. Therefore, it is necessary to evaluate the performance of protective clothing for penetration resistance against infectious agents. In Japan, some standard methods were established to evaluate the penetration resistance of protective clothing fabric materials under applied pressure. However, these methods only roughly classified the penetration resistance of fabrics, and the detection sensitivity of the methods and the penetration amount with respect to the relationship between blood and the pathogen have not been studied in detail. Moreover, no standard method using bacteria for evaluation is known. Here, to evaluate penetration resistance of protective clothing materials under applied pressure, the detection sensitivity and the leak amount were investigated by using synthetic blood containing bacteriophage phi-X174 or S. aureus. And the volume of leaked synthetic blood and the amount of test microbe penetration were simultaneously quantified. Our results showed that the penetration detection sensitivity achieved using a test microbial culture was higher than that achieved using synthetic blood at invisible leak level pressures. This finding suggested that there is a potential risk of pathogen penetration even when visual leak of contaminated blood through the protective clothing was not observed. Moreover, at visible leak level pressures, it was found that the amount of test microbe penetration varied at least ten-fold among protective clothing materials classified into the same class of penetration resistance. Analysis of the penetration amount revealed a significant correlation between the volume of penetrated synthetic blood and the amount of test microbe penetration, indicating that the leaked volume of synthetic

  14. Nugget hardfacing toughens roller cone bits

    SciTech Connect

    1996-11-25

    A new hardfacing material made of pure sintered tungsten carbide nuggets has improved roller cone rock bit performance in extremely hard lithologies, increasing penetration rates and extending bit life through multiple formations. In a recent test run in the Shushufindi 95 wells in Ecuador, a Security DBS 9 7/8-in. MPSF IADC 117M (International Association of Drilling Contractors bit code) bit with this new hardfacing drilled out the float equipment, cement, and show and then 3,309 ft of hard formations. The bit drilled through the Orteguaza claystone/shale/sand and chert formations and then to total depth at 6,309 ft in the Tiyuyacu shale/sand. The 3,309-ft interval was drilled at an average penetration rate (ROP) of 52.5 ft/hr. The proprietary nugget material was tested according to the American Society for Testing Materials (ASTM) G65 wear test method, a standard industry method of measuring wear resistance. The nugget material had ASTM wear test resistance more than twice that of standard hardfacing from conventional tungsten carbide.

  15. Test operations procedure (TOP) 8-2-501, permeation and penetration of air-permeable, semipermeable, and impermeable materials with chemical agents or simulants (swatch testing). Final report

    SciTech Connect

    1997-03-03

    This test operations procedure (TOP) provides the current standard for planning and conducting tests to measure the permeation or penetration of swatches of materials by chemical agents such as distilled mustard (HD), or the nerve agents sarin (GB), or V-agent (VX). The swatches may be single or multi-layered, inert, sorptive or reactive. Swatches may be taken from candidate or standardized fabrics, in which case application of this TOP can provide relative ranking or screening information about the ability of the standardized and/or candidate materials to resist permeation or penetration by chemical agents. Swatches may also be taken from garments that are new, have been stored, or have been worn for various times under different conditions. Testing these material swatches using the procedures in the TOP can provide data to evaluate the effects of the different condition of wear. This TOP is not adequate for the assessment of the ability of an end item clothing made from any tested material to protect the wearer. The data obtained by these procedures cannot be correlated to field conditions. One or more of the test procedures given may be required in a detailed test plan (DTP).

  16. Soft-tissue detectability in cone-beam CT: Evaluation by 2AFC tests in relation to physical performance metrics

    SciTech Connect

    Tward, D. J.; Siewerdsen, J. H.; Daly, M. J.; Richard, S.; Moseley, D. J.; Jaffray, D. A.; Paul, N. S.

    2007-11-15

    Soft-tissue detectability in cone-beam computed tomography (CBCT) was evaluated via two-alternative forced-choice (2AFC) tests. Investigations included the dependence of detectability on radiation dose, the influence of the asymmetric three-dimensional (3D) noise-power spectrum (NPS) in axial and sagittal or coronal planes, and the effect of prior knowledge on detectability. Custom-built phantoms ({approx}15 cm diameter cylinders) containing soft-tissue-simulating spheres of variable contrast and diameter were imaged on an experimental CBCT bench. The proportion of correct responses (P{sub corr}) in 2AFC tests was analyzed as a figure of merit, ideally equal to the area under the receiver operating characteristic curve. P{sub corr} was evaluated as a function of the sphere diameter (1.6-12.7 mm), contrast (20-165 HU), dose (1-7 mGy), plane of visualization (axial/sagittal), apodization filter (Hanning and Ram-Lak), and prior knowledge provided to the observer [ranging from stimulus known exactly (SKE) to stimulus unknown (SUK)]. Detectability limits were characterized in terms of the dose required to achieve a given level of P{sub corr} (e.g., 70%). For example, a 20 HU stimulus of diameter down to {approx}6 mm was detected with P{sub corr} 70% at dose {>=}2 mGy. Detectability tended to be greater in axial than in sagittal planes, an effect amplified by sharper apodization filters in a manner consistent with 3D NPS asymmetry. Prior knowledge had a marked influence on detectability - e.g., P{sub corr} for a {approx}6 mm(20 HU) sphere was {approx}55%-65% under SUK conditions, compared to {approx}70%-85% for SKE conditions. Human observer tests suggest practical implications for implementation of CBCT: (i) Detectability limits help to define minimum-dose imaging techniques for specific imaging tasks; (ii) detectability of a given structure can vary between axial and sagittal/coronal planes, owing to the spatial-frequency content of the 3D NPS in relation to the

  17. Soft-tissue detectability in cone-beam CT: evaluation by 2AFC tests in relation to physical performance metrics.

    PubMed

    Tward, D J; Siewerdsen, J H; Daly, M J; Richard, S; Moseley, D J; Jaffray, D A; Paul, N S

    2007-11-01

    Soft-tissue detectability in cone-beam computed tomography (CBCT) was evaluated via two-alternative forced-choice (2AFC) tests. Investigations included the dependence of detectability on radiation dose, the influence of the asymmetric three-dimensional (3D) noise-power spectrum (NPS) in axial and sagittal or coronal planes, and the effect of prior knowledge on detectability. Custom-built phantoms (approximately 15 cm diameter cylinders) containing soft-tissue-simulating spheres of variable contrast and diameter were imaged on an experimental CBCT bench. The proportion of correct responses (Pcorr) in 2AFC tests was analyzed as a figure of merit, ideally equal to the area under the receiver operating characteristic curve. Pcorr was evaluated as a function of the sphere diameter (1.6-12.7 mm), contrast (20-165 HU), dose (1-7 mGy), plane of visualization (axial/sagittal), apodization filter (Hanning and Ram-Lak), and prior knowledge provided to the observer [ranging from stimulus known exactly (SKE) to stimulus unknown (SUK)]. Detectability limits were characterized in terms of the dose required to achieve a given level of Pcorr (e.g., 70%). For example, a 20 HU stimulus of diameter down to approximately 6 mm was detected with Pcorr 70% at dose > or =2 mGy. Detectability tended to be greater in axial than in sagittal planes, an effect amplified by sharper apodization filters in a manner consistent with 3D NPS asymmetry. Prior knowledge had a marked influence on detectability--e.g., Pcorr for a approximately 6 mm (20 HU) sphere was approximately 55%-65% under SUK conditions, compared to approximately 70%-85% for SKE conditions. Human observer tests suggest practical implications for implementation of CBCT: (i) Detectability limits help to define minimum-dose imaging techniques for specific imaging tasks; (ii) detectability of a given structure can vary between axial and sagittal/coronal planes, owing to the spatial-frequency content of the 3D NPS in relation to the

  18. Measuring blood-brain barrier penetration using the NeuroCart, a CNS test battery.

    PubMed

    Groeneveld, Geert Jan; Hay, Justin Luke; Van Gerven, Johannes Marinus

    2016-06-01

    To systematically study the pharmacodynamics of a CNS drug early in the development process, we developed and validated a battery of drug-sensitive CNS tests, which we call NeuroCart. Using this test battery, data-intensive phase 1 studies in healthy subjects can be performed to demonstrate the specific, time- and dose-dependent, neurophysiological and/or neuropsychological effects of a compound, thereby confirming whether the test compound reaches its intended target in the CNS - or does not reach its intended target. We use this test battery to demonstrate that a compound passes the blood-brain barrier.

  19. Autonomous regulation of growth cone filopodia.

    PubMed

    Rehder, V; Cheng, S

    1998-02-05

    The fan-shaped array of filopodia is the first site of contact of a neuronal growth cone with molecules encountered during neuronal pathfinding. Filopodia are highly dynamic structures, and the "action radius" of a growth cone is strongly determined by the length and number of its filopodia. Since interactions of filopodia with instructive cues in the vicinity of the growth cone can have effects on growth cone morphology within minutes, it has to be assumed that a large part of the signaling underlying such morphological changes resides locally within the growth cone proper. In this study, we tested the hypothesis that two important growth cone parameters-namely, the length and number of its filopodia-are regulated autonomously in the growth cone. We previously demonstrated in identified neurons from the snail Helisoma trivolvis that filopodial length and number are regulated by intracellular calcium. Here, we investigated filopodial dynamics and their regulation by the second-messenger calcium in growth cones which were physically isolated from their parent neuron by neurite transection. Our results show that isolated growth cones have longer but fewer filopodia than growth cones attached to their parent cell. These isolated growth cones, however, are fully capable of undergoing calcium-induced cytoskeletal changes, suggesting that the machinery necessary to perform changes in filopodial length and number is fully intrinsic to the growth cone proper.

  20. Minnesota GPR Project 1998: testing ground penetrating radar technology on Minnesota roads and highways

    NASA Astrophysics Data System (ADS)

    Saarenketo, Timo; van Deusen, David; Maijala, Pekka

    2000-04-01

    During May 1998, Roadscanners Oy together with the Office of Minnesota Road Research performed a series of GPR tests in Minnesota, in order to determine the level of accuracy of the GPR technology in pavement and subgrade soil testing. The project involved a total of 195 km of GPR surveys carried out in different locations throughout Minnesota. The test sections represented a range of pavement materials, structures and soils found in the state. A number of GPR tests were performed to evaluate different types of pavement defect and ascertain their causes. The results of the Minnesota GPR Project 1998 clearly show the potential benefits that GPR techniques could offer the Minnesota Department of Transportation (DOT). The results of the Mn/ROAD tests show that GPR can be applied in measuring the layer thickness of various pavement structures. The surface reflection technique can be used to determine the signal velocity of both asphalt and concrete pavement structures. Mn/ROAD surveys also revealed evidence of some previously unknown defects in test cells, e.g. stripping, voids and moisture anomalies. A good example of the benefits the GPR technique can offer in detecting stripping is the T.H. 23, T.H. 71 Willmar case, where reference data, drill cores and FWD data matched almost perfectly with the GPR data. Another notable case presented in the paper is U.S. 52, Oronoco, where defects due to differential frost heave were located.

  1. Application of Poisson distribution theory to the zona-free hamster oocyte penetration test to assess sperm function of men with asthenozoospermia.

    PubMed

    Aitken, R J; Elton, R A

    1986-05-01

    Assessments of the penetrating potential of human spermatozoa were carried out using the zona-free hamster oocyte penetration test on 4 groups of subjects exhibiting normal fertility, idiopathic asthenozoospermia(less than 40% motility), asthenozoospermia associated with varicocele and oligoaesthenozoospermia (less than 20 X 10(6) spermatozoa/ml and less than 40% motility). When the Poisson model was used to correct the results of the in-vitro penetration experiments for differences in motile sperm concentration, significant differences were apparent between the normal fertile controls and all 3 categories of asthenozoospermic patient. Furthermore, the penetrating ability of the motile spermatozoa from patients presenting with a varicocele or oligoaesthenozoospermia was significantly less than that for the group in which asthenozoospermia was the only detectable defect. These results emphasize the practical significance of the Poisson model in the analysis of male fertility and demonstrate that the asthenozoospermic condition is associated with a significant reduction in the fertilizing potential of the motile spermatozoa.

  2. Metallurgy, Visual Inspection, Hardness and Liquid Penetrant Testing, Aviation Quality Control 2: 9227.01.

    ERIC Educational Resources Information Center

    Dade County Public Schools, Miami, FL.

    The course consists of the basic and simpler methods of inspecting and nondestructive testing of parts and materials to insure the quality and reliability of the finished product. The outline consists of six blocks totaling 135 hours: (1) defects in the metal ingot, (2) defects resulting from processing metals, (3) defects in metals in service,…

  3. GENERALIZED CONVEXITY CONES.

    DTIC Science & Technology

    Contents: Introduction The dual cone of C (psi sub 1,..., psi sub n) Extreme rays The cone dual to an intersection of generalized convexity cones... Generalized difference quotients and multivariate convexity Miscellaneous applications of generalized convexity.

  4. Penetration equations

    SciTech Connect

    Young, C.W.

    1997-10-01

    In 1967, Sandia National Laboratories published empirical equations to predict penetration into natural earth materials and concrete. Since that time there have been several small changes to the basic equations, and several more additions to the overall technique for predicting penetration into soil, rock, concrete, ice, and frozen soil. The most recent update to the equations was published in 1988, and since that time there have been changes in the equations to better match the expanding data base, especially in concrete penetration. This is a standalone report documenting the latest version of the Young/Sandia penetration equations and related analytical techniques to predict penetration into natural earth materials and concrete. 11 refs., 6 tabs.

  5. Improved seismic profiling by minimally invasive multimodal surface wave method with standard penetration test source (MMSW-SPT)

    NASA Astrophysics Data System (ADS)

    Lin, Shibin; Ashlock, Jeramy C.

    2017-03-01

    Surface waves propagating in layered media inherently possess multimodal dispersion characteristics. However, traditional surface wave testing methods employing measurements at the free surface usually capture only a single apparent dispersion curve, especially when using short geophone arrays common to near surface and geotechnical-scale investigations. Such single-mode or fragmented multimode apparent dispersion curves contain only a fraction of the possible dispersion information, thus limiting the accuracy of inverted profiles. To enable more robust measurement of higher Rayleigh-wave modes, a recently developed hybrid minimally invasive multimodal surface wave method is combined herein with the widely used geotechnical standard penetration test (SPT), which is employed as a practical and ubiquitous downhole source. Upon superimposing surface wave dispersion data for a range of SPT impact depths within the soil, higher modes can be measured more consistently and reliably relative to traditional non-invasive testing methods. As a result, misidentification of multiple dispersion modes can be practically eliminated, significantly improving the accuracy and certainty of inversion results.

  6. Integration of ground-penetrating radar, ultrasonic tests and infrared thermography for the analysis of a precious medieval rose window

    NASA Astrophysics Data System (ADS)

    Nuzzo, L.; Calia, A.; Liberatore, D.; Masini, N.; Rizzo, E.

    2010-04-01

    The integration of high-resolution, non-invasive geophysical techniques (such as ground-penetrating radar or GPR) with emerging sensing techniques (acoustics, thermography) can complement limited destructive tests to provide a suitable methodology for a multi-scale assessment of the state of preservation, material and construction components of monuments. This paper presents the results of the application of GPR, infrared thermography (IRT) and ultrasonic tests to the 13th century rose window of Troia Cathedral (Apulia, Italy), affected by widespread decay and instability problems caused by the 1731 earthquake and reactivated by recent seismic activity. This integrated approach provided a wide amount of complementary information at different scales, ranging from the sub-centimetre size of the metallic joints between the various architectural elements, narrow fractures and thin mortar fillings, up to the sub-metre scale of the internal masonry structure of the circular ashlar curb linking the rose window to the façade, which was essential to understand the original building technique and to design an effective restoration strategy.

  7. Validation and comparison between the low diffusion and DSMC method based on the 70° blunted cone test case

    NASA Astrophysics Data System (ADS)

    Mirza, A.; Nizenkov, P.; Fasoulas, S.

    2016-11-01

    Two particle-based methods, the established Direct Simulation Monte Carlo (DSMC) method and the novel Low Diffusion (LD) method, are compared in terms of accuracy and performance. While DSMC enables the physically accurate simulation of rarefied gas flows, LD enables the efficient simulation of dense flows under the continuum assumption. Both methods have been utilized to simulate the gas flow around a 70° blunted cone in a wide range of Knudsen numbers from 0.001 to 0.1, and are validated against existing experimental heat flux measurements. Additionally, flow field variables in front of the heat shield as well as surface properties are compared. Finally, the research towards a coupled application of both methods to enable the efficient and physically accurate simulation of flows with large density gradients is addressed.

  8. The First Three Dimensional Digital Models of Shatter Cones

    NASA Astrophysics Data System (ADS)

    Baratoux, D.; Bouley, S.; Reimold, W. U.; Baratoux, L.

    2014-09-01

    Shatter cones are used as a diagnostic evidence for impact, but model of formation is unclear. Geometrical parameters may offer critical tests. The first 3-D models of 30 shatter cones from 16 different impact structures are reported here.

  9. Results of Flight Tests to Determine Drag of Parabolic and Cone-cylinder Bodies of Very Large Fineness Ratios at Supersonic Speeds

    NASA Technical Reports Server (NTRS)

    Welsh, Clement J; Demoraes, Carlos A

    1951-01-01

    Results of a free-flight investigation at supersonic speeds to determine zero-lift drag of a series of bodies of revolution are presented. Configurations tested included two parabolic bodies with fineness ratios of 17.78 and 24.5 and two 8 degree cone-cylinder bodies with fineness ratios of 17.2 and 21.2. Results of previous tests of similar parabolic bodies but with lower fineness ratios are included in this paper for comparison. All bodies for which data are presented in this paper had a base-to-maximum-diameter ratio of 0.437. Calculated drag coefficients are shown for all bodies for which data are presented. (author)

  10. Cone-based electrical resistivity tomography

    NASA Astrophysics Data System (ADS)

    Pidlisecky, Adam

    Determining the 3-D spatial distribution of subsurface properties is a critical part of managing the clean-up of contaminated sites. Most standard hydrologic methods sample small regions immediately adjacent to wells or testing devices. This provides data which are not representative of the entire region of interest. Furthermore, at many contaminated sites invasive methods are not acceptable, due to the risks associated with contacting and spreading the contaminants. To address these issues, I have developed a minimally invasive technology that provides information about the 3-D distribution of electrical conductivity. This new technique, cone-based electrical resistivity tomography (C-bert), integrates the existing technologies of resistivity cone penetration testing (RCPT) with electrical resistivity tomography. Development of this tool included the creation of new software and modeling algorithms, the design of field equipment, field testing, and processing and interpretation of the resulting data. I present a 2.5-D forward modeling algorithm that incorporates an effective correction for the errors caused by boundary effects and source singularities. The algorithm includes an optimization technique for acquiring the Fourier coefficients required for the solution. A 3-D inversion algorithm is presented that has two major improvements over existing algorithms. First, it includes a 3-D version of the boundary correction/source singularity correction developed for the 2.5-D problem. Second, the algorithm can handle any type of acquisition geometry; this was a requirement for the development of C-bert. C-bert involves placing several permanent current electrodes in the subsurface and using electrodes mounted on a cone penetrometer and at the surface to measure the resultant potential field. In addition to these measurements, we obtain the standard suite of RCPT data, including high resolution resistivity logs. The RCPT data can be used to generate a realistic

  11. Optimization of Deep Drilling Performance - Development and Benchmark Testing of Advanced Diamond Product Drill Bits & HP/HT Fluids to Significantly Improve Rates of Penetration

    SciTech Connect

    Alan Black; Arnis Judzis

    2005-09-30

    This document details the progress to date on the OPTIMIZATION OF DEEP DRILLING PERFORMANCE--DEVELOPMENT AND BENCHMARK TESTING OF ADVANCED DIAMOND PRODUCT DRILL BITS AND HP/HT FLUIDS TO SIGNIFICANTLY IMPROVE RATES OF PENETRATION contract for the year starting October 2004 through September 2005. The industry cost shared program aims to benchmark drilling rates of penetration in selected simulated deep formations and to significantly improve ROP through a team development of aggressive diamond product drill bit--fluid system technologies. Overall the objectives are as follows: Phase 1--Benchmark ''best in class'' diamond and other product drilling bits and fluids and develop concepts for a next level of deep drilling performance; Phase 2--Develop advanced smart bit-fluid prototypes and test at large scale; and Phase 3--Field trial smart bit--fluid concepts, modify as necessary and commercialize products. As of report date, TerraTek has concluded all Phase 1 testing and is planning Phase 2 development.

  12. Whiskers, cones and pyramids created in sputtering by ion bombardment

    NASA Technical Reports Server (NTRS)

    Wehner, G. K.

    1979-01-01

    A thorough study of the role which foreign atoms play in cone formation during sputtering of metals revealed many experimental facts. Two types of cone formation were distinquished, deposit cones and seed cones. Twenty-six combinations of metals for seed cone formation were tested. The sputtering yield variations with composition for combinations which form seed cones were measured. It was demonstrated that whisker growth becomes a common occurrence when low melting point material is sputter deposited on a hot nonsputtered high melting point electrode.

  13. System design description cone penetrometer system

    SciTech Connect

    Seda, R.Y., Westinghouse Hanford

    1996-08-12

    The system design description documents in detail the design of the cone penetrometer system. The systems includes the cone penetrometer physical package, raman spectroscopy package and moisture sensor package. Information pertinent to the system design, development, fabrication and testing is provided.

  14. Cone Beam X-Ray Luminescence Tomography Imaging Based on KA-FEM Method for Small Animals

    PubMed Central

    Chen, Dongmei; Meng, Fanzhen; Zhao, Fengjun

    2016-01-01

    Cone beam X-ray luminescence tomography can realize fast X-ray luminescence tomography imaging with relatively low scanning time compared with narrow beam X-ray luminescence tomography. However, cone beam X-ray luminescence tomography suffers from an ill-posed reconstruction problem. First, the feasibility of experiments with different penetration and multispectra in small animal has been tested using nanophosphor material. Then, the hybrid reconstruction algorithm with KA-FEM method has been applied in cone beam X-ray luminescence tomography for small animals to overcome the ill-posed reconstruction problem, whose advantage and property have been demonstrated in fluorescence tomography imaging. The in vivo mouse experiment proved the feasibility of the proposed method. PMID:27868068

  15. Conception of a course for professional training and education in the field of computer and mobile forensics, part III: network forensics and penetration testing

    NASA Astrophysics Data System (ADS)

    Kröger, Knut; Creutzburg, Reiner

    2014-02-01

    IT security and computer forensics are important components in the information technology. From year to year, incidents and crimes increase that target IT systems or were done with their help. More and more companies and authorities have security problems in their own IT infrastructure. To respond to these incidents professionally, it is important to have well trained staff. The fact that many agencies and companies work with very sensitive data make it necessary to further train the own employees in the field of network forensics and penetration testing. Motivated by these facts, this paper - a continuation of a paper of January 2012 [1], which showed the conception of a course for professional training and education in the field of computer and mobile forensics - addresses the practical implementation important relationships of network forensic and penetration testing.

  16. Funnel cone for focusing intense ion beams on a target

    SciTech Connect

    Bieniosek, F.M.; Henestroza, E.; Ni, P.

    2009-10-05

    We describe a funnel cone for concentrating an ion beam on a target. The cone utilizes the reflection characteristic of ion beams on solid walls to focus the incident beam andincrease beam intensity on target. The cone has been modeled with the TRIM code. A prototype has been tested and installed for use in the 350-keV K+ NDCX target chamber.

  17. Supersonic Testing of 0.8 m Disk Gap Band Parachutes in the Wake of a 70 Deg Sphere Cone Entry Vehicle

    NASA Technical Reports Server (NTRS)

    Sengupta, Anita; Wernet, Mark; Roeder, James; Kelsch, Richard; Witkowski, Al; Jones, Thomas

    2009-01-01

    Supersonic wind tunnel testing of Viking-type 0.8 m Disk-Gap-Band (DGB) parachutes was conducted in the NASA Glenn Research Center 10'x10' wind-tunnel. The tests were conducted in support of the Mars Science Laboratory Parachute Decelerator System development and qualification program. The aerodynamic coupling of the entry-vehicle wake to parachute flow-field is under investigation to determine the cause and functional dependence of a supersonic canopy breathing phenomenon referred to as area oscillations, characteristic of DGB's above Mach 1.5 operation. Four percent of full-scale parachutes (0.8 m) were constructed similar to the flight-article in material and construction techniques. The parachutes were attached to a 70-deg sphere-cone entry-vehicle to simulate the Mars flight configuration. The parachutes were tested in the wind-tunnel from Mach 2 to 2.5 in a Reynolds number range of 2x105 to 1x106, representative of a Mars deployment. Three different test configurations were investigated. In the first two configurations, the parachutes were constrained horizontally through the vent region to measure canopy breathing and wake interaction for fixed trim angles of 0 and 10 degrees from the free-stream. In the third configuration the parachute was unconstrained, permitted to trim and cone, similar to free-flight (but capsule motion is constrained), varying its alignment relative to the entry-vehicle wake. Non-intrusive test diagnostics were chosen to quantify parachute performance and provide insight into the flow field structure. An in-line loadcell provided measurement of unsteady and mean drag. Shadowgraph of the upstream parachute flow field was used to capture bow-shock motion and wake coupling. Particle image velocimetry provided first and second order flow field statistics over a planar region of the flow field, just upstream of the parachute. A photogrammetric technique was used to quantify fabric motion using multiple high speed video cameras to record

  18. Microencapsulated Fluorescent Dye Penetrant.

    DTIC Science & Technology

    1979-07-01

    Microencapsulated fluorescent dye pentrant materials were evaluated for feasibility as a technique to detect cracks on metal surfaces when applied as...a free flowing dry powder. Various flourescent dye solutions in addition to a commercial penetrant (Zyglo ZL-30) were microencapsulated and tested on

  19. Deployable Wireless Camera Penetrators

    NASA Technical Reports Server (NTRS)

    Badescu, Mircea; Jones, Jack; Sherrit, Stewart; Wu, Jiunn Jeng

    2008-01-01

    A lightweight, low-power camera dart has been designed and tested for context imaging of sampling sites and ground surveys from an aerobot or an orbiting spacecraft in a microgravity environment. The camera penetrators also can be used to image any line-of-sight surface, such as cliff walls, that is difficult to access. Tethered cameras to inspect the surfaces of planetary bodies use both power and signal transmission lines to operate. A tether adds the possibility of inadvertently anchoring the aerobot, and requires some form of station-keeping capability of the aerobot if extended examination time is required. The new camera penetrators are deployed without a tether, weigh less than 30 grams, and are disposable. They are designed to drop from any altitude with the boost in transmitting power currently demonstrated at approximately 100-m line-of-sight. The penetrators also can be deployed to monitor lander or rover operations from a distance, and can be used for surface surveys or for context information gathering from a touch-and-go sampling site. Thanks to wireless operation, the complexity of the sampling or survey mechanisms may be reduced. The penetrators may be battery powered for short-duration missions, or have solar panels for longer or intermittent duration missions. The imaging device is embedded in the penetrator, which is dropped or projected at the surface of a study site at 90 to the surface. Mirrors can be used in the design to image the ground or the horizon. Some of the camera features were tested using commercial "nanny" or "spy" camera components with the charge-coupled device (CCD) looking at a direction parallel to the ground. Figure 1 shows components of one camera that weighs less than 8 g and occupies a volume of 11 cm3. This camera could transmit a standard television signal, including sound, up to 100 m. Figure 2 shows the CAD models of a version of the penetrator. A low-volume array of such penetrator cameras could be deployed from an

  20. Single wall penetration equations

    NASA Technical Reports Server (NTRS)

    Hayashida, K. B.; Robinson, J. H.

    1991-01-01

    Five single plate penetration equations are compared for accuracy and effectiveness. These five equations are two well-known equations (Fish-Summers and Schmidt-Holsapple), two equations developed by the Apollo project (Rockwell and Johnson Space Center (JSC), and one recently revised from JSC (Cour-Palais). They were derived from test results, with velocities ranging up to 8 km/s. Microsoft Excel software was used to construct a spreadsheet to calculate the diameters and masses of projectiles for various velocities, varying the material properties of both projectile and target for the five single plate penetration equations. The results were plotted on diameter versus velocity graphs for ballistic and spallation limits using Cricket Graph software, for velocities ranging from 2 to 15 km/s defined for the orbital debris. First, these equations were compared to each other, then each equation was compared with various aluminum projectile densities. Finally, these equations were compared with test results performed at JSC for the Marshall Space Flight Center. These equations predict a wide variety of projectile diameters at a given velocity. Thus, it is very difficult to choose the 'right' prediction equation. The thickness of a single plate could have a large variation by choosing a different penetration equation. Even though all five equations are empirically developed with various materials, especially for aluminum alloys, one cannot be confident in the shield design with the predictions obtained by the penetration equations without verifying by tests.

  1. Gas-jet and tangent-slot film cooling tests of a 12.5 deg cone at Mach number of 6.7

    NASA Technical Reports Server (NTRS)

    Nowak, Robert J.

    1988-01-01

    Tests were conducted in the Langley 8-Foot High Temperature Tunnel to determine the aerothermal effects of gaseous nitrogen-coolant ejection on a 3-ft base-diameter, 12.5 degree half-angle cone. Free-stream Mach number, total temperature, and unit Reynolds number per foot were 6.7, 3300 deg R, and 1.4 million, respectively. Two coolant ejection noses were tested, an ogive frustum with a forward-facing 0.8-in radius gas-jet tip, and a 3-in radius hemisphere with a 0.243-in high rearward-facing tangent slot. Data include surface pressures and heating rates, shock shapes, and shock-layer profiles; results are compared with no-cooling data obtained with 1-in and 3-in radius solid noses. Surface pressures were reduced with gas-jet ejection but were affected little by tangent-slot ejection. For both gas-jet and tangent-slot ejection, high coolant flow rates reduced heating even far downstream from the region of ejection; however, low coolant rates caused transition to turbulence and increased heating. Shock-layer profiles of pitot pressure, Mach number, and total temperature were reduced for both gas-jet and tangent-slot ejection. Insight into the gas-jet heat-flux mechanisms was obtained by using shock-layer rake data and established, no-cooling, heat-transfer equations.

  2. Genetic testing in Tunisian families with heritable retinoblastoma using a low cost approach permits accurate risk prediction in relatives and reveals incomplete penetrance in adults.

    PubMed

    Ayari Jeridi, Hajer; Bouguila, Hédi; Ansperger-Rescher, Birgit; Baroudi, Olfa; Mdimegh, Imen; Omran, Ines; Charradi, Khaoula; Bouzayene, Hssan; Benammar-Elgaaïed, Amel; Lohmann, Dietmar R

    2014-07-01

    Heritable retinoblastoma is caused by oncogenic mutations in the RB1 tumor suppressor gene. Identification of these mutations in patients is important for genetic counseling and clinical management of relatives at risk. In order to lower analytical efforts, we designed a stepwise mutation detection strategy that was adapted to the spectrum of oncogenic RB1 gene mutations. We applied this strategy on 20 unrelated patients with familial and/or de novo bilateral retinoblastoma from Tunisia. In 19 (95%) patients, we detected oncogenic mutations including base substitutions, small length mutations, and large deletions. Further analyses on the origin of the mutations showed mutational mosaicism in one unilaterally affected father of a bilateral proband and incomplete penetrance in two mothers. In a large family with several retinoblastoma patients, the mutation identified in the index patient was also detected in several non-penetrant relatives. RNA analyses showed that this mutation results in an in-frame loss of exon 9. In summary, our strategy can serve as a model for RB1 mutation identification with high analytical sensitivity. Our results point out that genetic testing is needed to reveal or exclude incomplete penetrance specifically in parents of patients with sporadic disease.

  3. Aerothermodynamic Testing of Protuberances and Penetrations on the NASA Crew Exploration Vehicle Heat Shield in the NASA Langley 20-Inch Mach 6 Air Tunnel

    NASA Technical Reports Server (NTRS)

    Liechty, Derek S.

    2008-01-01

    An experimental wind tunnel program is being conducted in support of an Agency wide effort to develop a replacement for the Space Shuttle and to support the NASA s long-term objective of returning to the moon and then on to Mars. This paper documents experimental measurements made on several scaled ceramic heat transfer models of the proposed Crew Exploration Vehicle. Global heat transfer images and heat transfer distributions obtained using phosphor thermography were used to infer interference heating on the Crew Exploration Vehicle Cycle 1 heat shield from local protuberances and penetrations for both laminar and turbulent heating conditions. Test parametrics included free stream Reynolds numbers of 1.0x10(exp 6)/ft to 7.25x10(exp 6)/ft in Mach 6 air at a fixed angle-of-attack. Single arrays of discrete boundary layer trips were used to trip the boundary layer approaching the protuberances/penetrations to a turbulent state. Also, the effects of three compression pad diameters, two radial locations of compression pad/tension tie location, compression pad geometry, and rotational position of compression pad/tension tie were examined. The experimental data highlighted in this paper are to be used to validate CFD tools that will be used to generate the flight aerothermodynamic database. Heat transfer measurements will also assist in the determination of the most appropriate engineering methods that will be used to assess local flight environments associated with protuberances/penetrations of the CEV thermal protection system.

  4. Berkeley Lighting Cone

    SciTech Connect

    Lask, Kathleen; Gadgil, Ashok

    2016-10-24

    A lighting cone is a simple metal cone placed on the fuel bed of a stove during ignition to act as a chimney, increasing the draft through the fuel bed. Many stoves tend to be difficult to light due to poor draft through the fuel bed, so lighting cones are used in various parts of the world as an inexpensive accessory to help with ignition.

  5. In vitro study on the softening of gutta-percha cones in endodontic retreatment.

    PubMed

    Pécora, J D; Spanó, J C; Barbin, E L

    1993-01-01

    Softening time of gutta-percha cones was studied in vitro using five chemical solvents: xylol, chloroform, turpentine, eucalyptol, and orange oil. An apparatus which reproduces the penetration force of an endodontic file was used on the sectioned roots of previously filled teeth. The most rapid chemical solvent of gutta-percha cones was chloroform and the slowest was eucalyptol.

  6. Modal content of living human cone photoreceptors

    PubMed Central

    Liu, Zhuolin; Kocaoglu, Omer P.; Turner, Timothy L.; Miller, Donald T.

    2015-01-01

    Decades of experimental and theoretical investigations have established that photoreceptors capture light based on the principles of optical waveguiding. Yet considerable uncertainty remains, even for the most basic prediction as to whether photoreceptors support more than a single waveguide mode. To test for modal behavior in human cone photoreceptors in the near infrared, we took advantage of adaptive-optics optical coherence tomography (AO-OCT, λc = 785 nm) to noninvasively image in three dimensions the reflectance profile of cones. Modal content of reflections generated at the cone inner segment and outer segment junction (IS/OS) and cone outer segment tip (COST) was examined over a range of cone diameters in 1,802 cones from 0.6° to 10° retinal eccentricity. Second moment analysis in conjunction with theoretical predictions indicate cone IS and OS have optical properties consistent of waveguides, which depend on segment diameter and refractive index. Cone IS was found to support a single mode near the fovea (≤3°) and multiple modes further away (>4°). In contrast, no evidence of multiple modes was found in the cone OSs. The IS/OS and COST reflections share a common optical aperture, are most circular near the fovea, show no orientation preference, and are temporally stable. We tested mode predictions of a conventional step-index fiber model and found that in order to fit our AO-OCT results required a lower estimate of the IS refractive index and introduction of an IS focusing/tapering effect. PMID:26417509

  7. Explosive shaped charge penetration into tuff rock

    SciTech Connect

    Vigil, M.G.

    1988-10-01

    Analysis and data for the use of Explosive Shaped Charges (ESC) to generate holes in tuff rock formation is presented. The ESCs evaluated include Conical Shaped Charges (CSC) and Explosive Formed Projectiles (EFP). The CSCs vary in size from 0.158 to 9.1 inches inside cone diameter. The EFPs were 5.0 inches in diameter. Data for projectile impact angles of 30 and 90 degrees are presented. Analytically predicted depth of penetration data generally compared favorably with experimental data. Predicted depth of penetration versus ESC standoff data and hole profile dimensions in tuff are also presented. 24 refs., 45 figs., 6 tabs.

  8. Penetration Mechanics of Composites

    DTIC Science & Technology

    1992-04-01

    distribution for tensile strength of hollow virgin filaments, based on 128 tests (source: Owens / Corning Fiberglas Corp). 14 1.2 Schematic of split Hopkinson...These were supplied by Owens / Corning Fiberglas Corporation, Granville, Ohio in two forms: 463AA750 (750 yd/lb) roving tow and G150 (1500 yd/lb...penetration of 12.7-mm thick (25-ply) GRP. Targets were fabricated by Owens Corning Fiberglas (OCF) by a licensed process designated HJ1. This complies

  9. An Earth Penetrating Modeling Assessment

    SciTech Connect

    Stokes, E; Yarrington, P; Glenn, L

    2005-06-21

    Documentation of a study to assess the capability of computer codes to predict lateral loads on earth penetrating projectiles under conditions of non-normal impact. Calculations simulated a set of small scale penetration tests into concrete targets with oblique faces at angles of 15 and 30 degrees to the line-of-flight. Predictive codes used by the various calculational teams cover a wide range of modeling approaches from approximate techniques, such as cavity expansion, to numerical methods, such as finite element codes. The modeling assessment was performed under the auspices of the Phenomenology Integrated Product Team (PIPT) for the Robust Nuclear Earth Penetrator Program (RNEP). Funding for the penetration experiments and modeling was provided by multiple earth penetrator programs.

  10. Optimization of Deep Drilling Performance--Development and Benchmark Testing of Advanced Diamond Product Drill Bits & HP/HT Fluids to Significantly Improve Rates of Penetration

    SciTech Connect

    Alan Black; Arnis Judzis

    2003-10-01

    This document details the progress to date on the OPTIMIZATION OF DEEP DRILLING PERFORMANCE--DEVELOPMENT AND BENCHMARK TESTING OF ADVANCED DIAMOND PRODUCT DRILL BITS AND HP/HT FLUIDS TO SIGNIFICANTLY IMPROVE RATES OF PENETRATION contract for the year starting October 2002 through September 2002. The industry cost shared program aims to benchmark drilling rates of penetration in selected simulated deep formations and to significantly improve ROP through a team development of aggressive diamond product drill bit--fluid system technologies. Overall the objectives are as follows: Phase 1--Benchmark ''best in class'' diamond and other product drilling bits and fluids and develop concepts for a next level of deep drilling performance; Phase 2--Develop advanced smart bit--fluid prototypes and test at large scale; and Phase 3--Field trial smart bit--fluid concepts, modify as necessary and commercialize products. Accomplishments to date include the following: 4Q 2002--Project started; Industry Team was assembled; Kick-off meeting was held at DOE Morgantown; 1Q 2003--Engineering meeting was held at Hughes Christensen, The Woodlands Texas to prepare preliminary plans for development and testing and review equipment needs; Operators started sending information regarding their needs for deep drilling challenges and priorities for large-scale testing experimental matrix; Aramco joined the Industry Team as DEA 148 objectives paralleled the DOE project; 2Q 2003--Engineering and planning for high pressure drilling at TerraTek commenced; 3Q 2003--Continuation of engineering and design work for high pressure drilling at TerraTek; Baker Hughes INTEQ drilling Fluids and Hughes Christensen commence planning for Phase 1 testing--recommendations for bits and fluids.

  11. Some Effects of Air Flow on the Penetration and Distribution of Oil Sprays

    NASA Technical Reports Server (NTRS)

    Rothrock, A M; Beardsley, E G

    1929-01-01

    Tests were made to determine the effects of air flow on the characteristics of fuel sprays from fuel injection valves. Curves and photographs are presented showing the airflow throughout the chamber and the effects of the air flow on the fuel spray characteristics. It was found that the moving air had little effect on the spray penetration except with the 0.006 inch orifice. The moving air did, however, affect the oil particles on the outside of the spray cone. After spray cut-off, the air flow rapidly distributed the atomized fuel throughout the spray chamber.

  12. Pneumatic and Percussive Penetration Approaches for Heat Flow Probe Emplacement on Robotic Lunar Missions

    NASA Astrophysics Data System (ADS)

    Zacny, K.; Nagihara, S.; Hedlund, M.; Paulsen, G.; Shasho, J.; Mumm, E.; Kumar, N.; Szwarc, T.; Chu, P.; Craft, J.; Taylor, P.; Milam, M.

    2013-11-01

    In this paper, the development of heat flow probes for measuring the geothermal gradient and conductivity of lunar regolith are presented. These two measurements are the required information for determining the heat flow of a planetary body. Considering the Moon as an example, heat flow properties are very important information for studying the radiogenic isotopes, the thermal evolution and differentiation history, and the mechanical properties of the interior. In order to obtain the best measurements, the sensors must be extended to a depth of at least 3 m, i.e. beyond the depth of significant thermal cycles. Two approaches to heat flow deployment and measurement are discussed in this paper: a percussive approach and a pneumatic approach. The percussive approach utilizes a high frequency hammer to drive a cone penetrometer into the lunar simulant. Ring-like thermal sensors (heaters and temperature sensors) on the penetrometer rod are deployed into the simulant every 30 cm as the penetrometer penetrates to the required 3 m depth. Once the target depth has been achieved, the deployment rod is removed from the simulant, eliminating any thermal path to the lander. The pneumatic approach relies on pressurized gas to excavate, using a cone-shaped nozzle to penetrate the simulant. The nozzle is attached to a coiled stem with thermal sensors embedded along the length of the stem. As the simulant is being lofted out of the hole by the escaping gas, the stem is progressively reeled out from a spool, thus moving the cone deeper into the hole. Thermal conductivity is measured using a needle probe attached to the end of the cone. Breadboard prototypes of these two heat flow probe systems have been constructed and successfully tested under lunar-like conditions to approximately 70 cm, which was the maximum possible depth allowed by the size of the test bin and the chamber.

  13. OPTIMIZATION OF DEEP DRILLING PERFORMANCE--DEVELOPMENT AND BENCHMARK TESTING OF ADVANCED DIAMOND PRODUCT DRILL BITS & HP/HT FLUIDS TO SIGNIFICANTLY IMPROVE RATES OF PENETRATION

    SciTech Connect

    Alan Black; Arnis Judzis

    2004-10-01

    The industry cost shared program aims to benchmark drilling rates of penetration in selected simulated deep formations and to significantly improve ROP through a team development of aggressive diamond product drill bit--fluid system technologies. Overall the objectives are as follows: Phase 1--Benchmark ''best in class'' diamond and other product drilling bits and fluids and develop concepts for a next level of deep drilling performance; Phase 2--Develop advanced smart bit-fluid prototypes and test at large scale; and Phase 3--Field trial smart bit-fluid concepts, modify as necessary and commercialize products. As of report date, TerraTek has concluded all major preparations for the high pressure drilling campaign. Baker Hughes encountered difficulties in providing additional pumping capacity before TerraTek's scheduled relocation to another facility, thus the program was delayed further to accommodate the full testing program.

  14. SU-E-J-109: Testing the KV Imaging Center Congruence with Radiation Isocenter of Small MLC and SRS Cone Field On Two Machines

    SciTech Connect

    Fu,; Chen, Y; Yu, Y; Liu, H

    2014-06-01

    Purpose: Orthogonal kV image pairs are used for target localization when fiducial markers are implanted. CBCT is used to verify cone SRS setup. Therefore it is necessary to evaluate the isocenter congruence between radiation fields and kV imaging center. This study used a simple method to evaluate the isocenter congruence, and compared the results for MLC and cone fields on two different Linacs. Methods: Varian OBI block was attached on the couch. It has a central 1mm BB with markers on three surfaces to align with laser. KV and MV images were taken at four cardinal angles. A 3x3cm2 MLC field and a 20mm cone field were irradiated respectively. On each kV image, the distance from BB center to the kV graticule center were measured. On the MV image of MLC field, the center of radiation field was determined manually, while for cone field, the Varian AM maintenance software was used to analyze the distance between BB and radiation field. The subtraction of the two distances gives the discrepancy between kV and radiation centers. Each procedure was repeated on five days at Trilogy and TrueBeam respectively. Results: The maximum discrepancy was found in the longitudinal direction at 180° gantry angel. It was 1.5±0.1mm for Trilogy and 0.6±0.1mm for TrueBeam. For Trilogy, although radiation center wobbled only 0.7mm and image center wobbled 0.8mm, they wobbled to the opposite direction. KV Pair using gantry 180° should be avoided in this case. Cone vs. kV isocenter has less discrepancy than MLC for Trilogy. Conclusion: Radiation isocenter of MLC and cone field is different, so is between Trilogy and TrueBeam. The method is simple and reproducible to check kV and radiation isocenter congruence.

  15. Arias intensity assessment of liquefaction test sites on the east side of San Francisco Bay affected by the Loma Prieta, California, earthquake of 17 October 1989

    USGS Publications Warehouse

    Kayen, R.E.

    1997-01-01

    Abstract. Uncompacted artificial-fill deposits on the east side of San Francisco Bay suffered severe levels of soil liquefaction during the Loma Prieta earthquake of 17 October 1989. Damaged areas included maritime-port facilities, office buildings, and shoreline transportation arteries, ranging from 65 to 85 km from the north end of the Loma Prieta rupture zone. Typical of all these sites, which represent occurrences of liquefaction-induced damage farthest from the rupture zone, are low cone penetration test and Standard Penetration Test resistances in zones of cohesionless silty and sandy hydraulic fill, and underlying soft cohesive Holocene and Pleistocene sediment that strongly amplified ground motions. Postearthquake investigations at five study sites using standard penetration tests and cone penetration tests provide a basis for evaluation of the Arias intensity-based methodology for assessment of liquefaction susceptibility. ?? 1997 Kluwer Academic Publishers.

  16. Growth cone collapse assay.

    PubMed

    Cook, Geoffrey M W; Jareonsettasin, Prem; Keynes, Roger J

    2014-01-01

    The growth cone collapse assay has proved invaluable in detecting and purifying axonal repellents. Glycoproteins/proteins present in detergent extracts of biological tissues are incorporated into liposomes, added to growth cones in culture and changes in morphology are then assessed. Alternatively purified or recombinant molecules in aqueous solution may be added directly to the cultures. In both cases after a defined period of time (up to 1 h), the cultures are fixed and then assessed by inverted phase contrast microscopy for the percentage of growth cones showing a collapsed profile with loss of flattened morphology, filopodia, and lamellipodia.

  17. Prediction of alumina penetration

    SciTech Connect

    Mandell, D A

    1993-02-01

    The MESA hydrocode was used to predict two-dimensional tests of L/D 10 and L/D 15 tungsten rods impacting AD 90 alumina with a steel backing. The residual penetration into the steel is the measured quantity in these experiments conducted at the Southwest Research Institute (SWR). The interface velocity as a function of time between an alumina target and a lithium fluoride window, impacted by an alumina disk at velocities between 544 m/s and 2329 m/s, was also predicted. These one-dimensional flyer plate experiments were conducted at Sandia National Laboratories using Coors AD 995 alumina. The material strength and fracture models are important in the prediction of ceramic experiments. The models used in these predictions are discussed. The penetrations in the two-dimensional tests were predicted to 11.4 percent or better. In five of the six experiments, the predicted penetration depth was deeper than the measured value. This trend is expected since the calculation is based on ideal conditions. The results show that good agreement between the 1-D flyer plate data and the MESA predictions exists at the lower impact velocities, but the maximum velocity is overpredicted as the flyer plate velocity increases. At a flyer plate velocity of 2329 m/s the code overpredicted the data by 12.3 percent.

  18. Use of Sandia's Central Receiver Test Facility as a high-intensity heat source for testing missile nose-cone (Radome) radar systems

    SciTech Connect

    Porter, D.R.

    1981-09-01

    A series of tests at Sandia's Central Receiver Test Facility in support of the US Navy's SM-2 Blk 2 Radome Improvement Program is described. The CRTF was the source of high-intensity solar radiation for testing onboard radar-tracking systems under heating conditions intended to simulate those that occur in supersonic flight. Also discussed are the hardware used and the software developed at the CRTF.

  19. Effect of gravity and capillarity on human saliva penetration in coronally unsealed obturated root canals

    PubMed Central

    Karamifar, Kasra; Khayat, Akbar; Mogharrabi, Sara; Rajaei, Yasaman; Saghiri, Mohammad Ali

    2012-01-01

    Aim The purpose of this study was to evaluate the effect of gravity and capillarity on penetration of human salivary bacteria into the entire length of obturated root canals, and to demonstrate the dye penetration configuration. Materials and methods Fifty single-rooted premolars were decoronated, prepared to a standardized length of 15 mm, instrumented, and randomly divided into two groups (A and B) of 25 teeth each. Each group consisted of experimental (15 samples) and negative and positive controls (five samples each). The experimental groups were obturated with gutta-percha and root canal sealer. The positive control groups were obturated with a single cone of gutta-percha and root canal sealer. The outer surfaces (except for the apical 2 mm) were covered with two layers of nail varnish. An apparatus containing Brain Heart Infusion broth was designed, in which the teeth were placed. The samples in Group A were placed upside down, while Group B was placed normally. The coronal portions of the samples were placed in contact with fresh saliva. The number of days required for bacteria to penetrate the entire length of canals was determined. The samples were then immersed in India ink to determine the dye penetration configuration. Data were analyzed using Student’s t-test. Results The extent of dye penetration was significantly greater in Group B compared to Group A, and they were in a pattern rather than linear form. Conclusions Gravity and capillarity insignificantly affected bacterial leakage. Although gravity and capillarity did not affect bacterial penetration when applied to the coronal access of endodontically treated teeth, it seems that they can promote penetration of India ink into the canal after the bacterial test on the same tooth. PMID:23960545

  20. Testing for viral penetration of non-latex surgical and examination gloves: a comparison of three methods.

    PubMed

    O'Connell, K P; El-Masri, M; Broyles, J B; Korniewicz, D M

    2004-04-01

    Currently, there are no international standards based on microbiological methodology for testing the ability of medical examination or surgical gloves to prevent the passage of viruses. Three protocols for the direct examination of the viral barrier properties of non-latex gloves were compared with 1080 gloves (270 gloves from each of two surgical brands and two medical examination brands). In two of the methods, gloves were filled with and suspended in a nutrient broth solution, and bacteriophage phiX174 was placed either inside or outside the glove, while the entire test vessel was agitated. Gloves tested using the third method were filled with a suspension of bacteriophage and allowed to rest in a vessel containing nutrient broth. Gloves were tested directly from the manufacturer's packaging, or after being punctured intentionally or subjected to a stress protocol. The passage of bacteriophage was detected with plaque assays. Significant differences in failure rates between glove brands were apparent only among gloves that had been subjected to the stress protocol. Overall, the two methods in which bacteriophage were placed inside the gloves provided more sensitivity than the method in which bacteriophage was spiked into broth outside the gloves. Thus the placement of bacteriophage inside test gloves (or the use of pressure across the glove barrier during testing), and the use of a standardised stress protocol, will improve significantly the ability of a glove test protocol to determine the relative quality of the barrier offered by medical examination and surgical gloves. Further research is needed to provide test methods that can incorporate reproducibly both the use of bacteriophage and simulated glove use in an industrial quality control setting.

  1. 2017 Eclipse Shadow Cones

    NASA Video Gallery

    A solar eclipse occurs when the Moon's shadow falls on the Earth. The shadow comprises two concentric cones called the umbra and the penumbra. Within the smaller, central umbra, the Sun is complete...

  2. HSURIA Cone Centration.

    DTIC Science & Technology

    1981-09-01

    laser. b. Interferometer configuration. This configuration (Fig. 4) uses a Twyman -Green interferometer to measure the cone centration for comparison...autocollimator. The interferometer mode, as was explained in Section Ill-l, gave very little information about the alignment of the cone. c. Physical...the camera turning flat (5) must be removed and the centration sensor laser is used. The interferometer laser is turned off. For the interferometer

  3. Soil properties and performance of landmine detection by metal detector and ground-penetrating radar — Soil characterisation and its verification by a field test

    NASA Astrophysics Data System (ADS)

    Takahashi, Kazunori; Preetz, Holger; Igel, Jan

    2011-04-01

    Metal detectors have commonly been used for landmine detection, and ground-penetrating radar (GPR) is about to be deployed for this purpose. These devices are influenced by the magnetic and electric properties of soil, since both employ electromagnetic techniques. Various soil properties and their spatial distributions were measured and determined with geophysical methods in four soil types where a test of metal detectors and GPR systems took place. By analysing the soil properties, these four soils were classified based on the expected influence of each detection technique and predicted soil difficulty. This classification was compared to the detection performance of the detectors and a clear correlation between the predicted soil difficulty and performance was observed. The detection performance of the metal detector and target identification performance of the GPR systems degraded in soils that were expected to be problematic. Therefore, this study demonstrated that the metal detector and GPR performance for landmine detection can be assessed qualitatively by geophysical analyses.

  4. Penetration of Rod Projectiles in Semi-Infinite Targets: A Validation Test for Eulerian X-FEM in Alegra

    DTIC Science & Technology

    2013-03-12

    NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND...ADDRESS(ES) Sandia National Laboratories,Geomechanics Department,P.O. Box 5800,Albuquerque,NM,87185 8. PERFORMING ORGANIZATION REPORT NUMBER 9...testing in environments that are representative of the software application space. One application for which ALEGRA is used is high-velocity impact

  5. Rod-cone interactions and analysis of retinal disease.

    PubMed Central

    Arden, G B; Hogg, C R

    1985-01-01

    Cone flicker threshold rises as the rods dark adapt, though the cone threshold to continuous light remains constant. The rise is normally about 1 log unit, but in certain patients who complain of night blindness it may be as great as 2.5 log units. In these persons the kinetics of the rod-cone interaction are those of the recovery of rod sensitivity. The rods impose a low-pass filter on the cones. This effect is absent in congenital nyctalopia and X-linked retinoschisis. We suggest that cone flicker is maintained through a feedback system involving horizontal cells, and when the rod dark current returns in dark adaptation this feedback is altered. Rod cone interaction thus tests rod dark current, and cases of abnormal interaction in patients with retinitis pigmentosa occur, which indicate that the transduction mechanism and the membrane dark current may be differentially affected. Images PMID:3873959

  6. Optimal shapes of axisymmetric bodies penetrating into soil

    NASA Astrophysics Data System (ADS)

    Kotov, V. L.; Linnik, E. Yu.; Tarasova, A. A.

    2016-09-01

    This paper presents the results of a study of the shapes of axisymmetric bodies with minimum drag and maximum depth of penetration into the plastic soils. Optimal shapes of bodies of revolution of given length and cross-sectional radius with generatrices represented by line segments are obtained by a modified method of local variations. The problem is solved using a binomial quadratic model of local interaction, including inertial and strength terms containing constant and Coulomb frictions. The drag forces and the penetration depth of cones and the obtained bodies of optimal shape are determined at different penetration velocities.

  7. The cone dysfunction syndromes

    PubMed Central

    Aboshiha, Jonathan; Dubis, Adam M; Hardcastle, Alison J; Michaelides, Michel

    2016-01-01

    The cone dysfunction syndromes are a heterogeneous group of inherited, predominantly stationary retinal disorders characterised by reduced central vision and varying degrees of colour vision abnormalities, nystagmus and photophobia. This review details the following conditions: complete and incomplete achromatopsia, blue-cone monochromatism, oligocone trichromacy, bradyopsia and Bornholm eye disease. We describe the clinical, psychophysical, electrophysiological and imaging findings that are characteristic to each condition in order to aid their accurate diagnosis, as well as highlight some classically held notions about these diseases that have come to be challenged over the recent years. The latest data regarding the genetic aetiology and pathological changes observed in the cone dysfunction syndromes are discussed, and, where relevant, translational avenues of research, including completed and anticipated interventional clinical trials, for some of the diseases described herein will be presented. Finally, we briefly review the current management of these disorders. PMID:25770143

  8. Numerical Modeling of Shatter Cones Development in Impact Craters

    NASA Astrophysics Data System (ADS)

    Baratoux, D.; Melosh, H. J.

    2003-03-01

    We present a new model for the formation of shatter cones in impact craters. Our model has been tested by means of numerical simulations. Our results are consistent with the observations of shatter cones in natural impact craters and explosions experiments.

  9. Double-Plate Penetration Equations

    NASA Technical Reports Server (NTRS)

    Hayashida, K. B.; Robinson, J. H.

    2000-01-01

    This report compares seven double-plate penetration predictor equations for accuracy and effectiveness of a shield design. Three of the seven are the Johnson Space Center original, modified, and new Cour-Palais equations. The other four are the Nysmith, Lundeberg-Stern-Bristow, Burch, and Wilkinson equations. These equations, except the Wilkinson equation, were derived from test results, with the velocities ranging up to 8 km/sec. Spreadsheet software calculated the projectile diameters for various velocities for the different equations. The results were plotted on projectile diameter versus velocity graphs for the expected orbital debris impact velocities ranging from 2 to 15 km/sec. The new Cour-Palais double-plate penetration equation was compared to the modified Cour-Palais single-plate penetration equation. Then the predictions from each of the seven double-plate penetration equations were compared to each other for a chosen shield design. Finally, these results from the equations were compared with test results performed at the NASA Marshall Space Flight Center. Because the different equations predict a wide range of projectile diameters at any given velocity, it is very difficult to choose the "right" prediction equation for shield configurations other than those exactly used in the equations' development. Although developed for various materials, the penetration equations alone cannot be relied upon to accurately predict the effectiveness of a shield without using hypervelocity impact tests to verify the design.

  10. Penetration of concrete targets

    SciTech Connect

    Forrestal, M.J.; Cargile, J.D.; Tzou, R.D.Y.

    1993-08-01

    We developed penetration equations for ogive-nosed projectiles that penetrated concrete targets after normal impact. Our penetration equations predict axial force on the projectile nose, rigid-body motion, and final penetration depth. For target constitutive models, we conducted triaxial material experiments to confining pressures of 600 MPa and curve-fit these data with a linear pressure-volumetric strain relation and with a linear Mohr-Coulomb, shear strength-pressure relation. To verify our penetration equations, we conducted eleven penetration experiments with 0.90 kg, 26.9-mm-diameter, ogive-nosed projectiles into 1.37-m-diameter concrete targets with unconfined compressive strengths between 32-40 MPa. Predictions from our penetration equation are compared with final penetration depth measurements for striking velocities between 280--800 m/s.

  11. Heat-transfer test results for a .0275-scale space shuttle external tank with a 10 deg/40 deg double cone-ogive nose in the NASA/AMES 3.5-foot hypersonic wind tunnel (FH14), volume 2

    NASA Technical Reports Server (NTRS)

    Carroll, H. R.

    1977-01-01

    A .0275 scale forebody model of the new baseline configuration of the space shuttle external tank vent cap configuration was tested to determine the flow field due to the double cone configuration. The tests were conducted in a 3.5 foot hypersonic wind tunnel at alpha = -5 deg, -4.59 deg, 0 deg, 5 deg, and 10 deg; beta = 0 deg, -3 deg, -5.51 deg, -6 deg, -9 deg, and +6 deg; nominal freestream Reynolds numbers per foot of 1.5 x 1 million, 3.0 x 1 million, and 5.0 x 1 million; and a nominal Mach number of 5. Separation and reattached flow from thermocouple data, shadowgraphs, and oil flows indicate that separation begins about 80% from the tip of the 10 deg cone, then reattaches on the vent cap and produces fully turbulent flow over most of the model forebody. The hardware disturbs the flow over a much larger area than present TPS application has assumed. A correction to the flow disturbance was experimentally suggested from the results of an additional test run.

  12. AX Tank farm closure settlement estimates and soil testing

    SciTech Connect

    BECKER, D.L.

    1999-03-25

    This study provides a conservative three-dimensional settlement study of the AX Tank Farm closure with fill materials and a surface barrier. The finite element settlement model constructed included the interaction of four tanks and the surface barrier with the site soil and bedrock. Also addressed are current soil testing techniques suitable for the site soil with recommendations applicable to the AX Tank Farm and the planned cone penetration testing.

  13. The absolute threshold of cone vision

    PubMed Central

    Koeing, Darran; Hofer, Heidi

    2013-01-01

    We report measurements of the absolute threshold of cone vision, which has been previously underestimated due to sub-optimal conditions or overly strict subjective response criteria. We avoided these limitations by using optimized stimuli and experimental conditions while having subjects respond within a rating scale framework. Small (1′ fwhm), brief (34 msec), monochromatic (550 nm) stimuli were foveally presented at multiple intensities in dark-adapted retina for 5 subjects. For comparison, 4 subjects underwent similar testing with rod-optimized stimuli. Cone absolute threshold, that is, the minimum light energy for which subjects were just able to detect a visual stimulus with any response criterion, was 203 ± 38 photons at the cornea, ∼0.47 log units lower than previously reported. Two-alternative forced-choice measurements in a subset of subjects yielded consistent results. Cone thresholds were less responsive to criterion changes than rod thresholds, suggesting a limit to the stimulus information recoverable from the cone mosaic in addition to the limit imposed by Poisson noise. Results were consistent with expectations for detection in the face of stimulus uncertainty. We discuss implications of these findings for modeling the first stages of human cone vision and interpreting psychophysical data acquired with adaptive optics at the spatial scale of the receptor mosaic. PMID:21270115

  14. A novel discontinuous Galerkin time-domain method for ground-penetrating radar simulation with applications to the ASSESS-GPR test site

    NASA Astrophysics Data System (ADS)

    Fahlke, J.; Buchner, J.; Ippisch, O.; Roth, K.; Bastian, P.

    2012-04-01

    The simulation of ground-penetrating radar (GPR) measurements requires the solution of Maxwell's equations. While finite-differences time-domain (FDTD) solvers are faster on structured grids, finite-element time-domain (FETD) and discontinuous Galerkin time-domain (DGTD) allow to resolve complicated structures and avoid staircase approximations. Soil horizon boundaries can be resolved exactly by the finite element mesh. In this contribution 3D simulations are compared with measurements from the ASSESS-GPR test site which is an artificial GPR testbed with a well known geometry and ground-truth on volumetric water content provided by 32 TDR probes. For the simulations a DGTD method is used in a dual-field formulation and compared to a standard FETD method with conforming edge-based finite elements. The software for the simulation has been developed using the Distributed and Unified Numerics Environment (DUNE) and its PDELab discretization module. The programs have been parallelized using MPI to make computations on the size of 108 unknowns feasible.

  15. Tilted cone beam VCT reconstruction algorithm

    NASA Astrophysics Data System (ADS)

    Hsieh, Jiang; Tang, Xiangyang

    2005-04-01

    Reconstruction algorithms for volumetric CT have been the focus of many studies. Several exact and approximate reconstruction algorithms have been proposed for step-and-shoot and helical scanning trajectories to combat cone beam related artifacts. In this paper, we present a closed form cone beam reconstruction formula for tilted gantry data acquisition. Although several algorithms were proposed to compensate for errors induced by the gantry tilt, none of the algorithms addresses the case in which the cone beam geometry is first rebinned to a set of parallel beams prior to the filtered backprojection. Because of the rebinning process, the amount of iso-center adjustment depends not only on the projection angle and tilt angle, but also on the reconstructed pixel location. The proposed algorithm has been tested extensively on both 16 and 64 slice VCT with phantoms and clinical data. The efficacy of the algorithm is clearly demonstrated by the experiments.

  16. Overview: Hard Rock Penetration

    SciTech Connect

    Dunn, J.C.

    1992-08-01

    The Hard Rock Penetration program is developing technology to reduce the costs of drilling and completing geothermal wells. Current projects include: lost circulation control, rock penetration mechanics, instrumentation, and industry/DOE cost shared projects of the Geothermal Drilling organization. Last year, a number of accomplishments were achieved in each of these areas. A new flow meter being developed to accurately measure drilling fluid outflow was tested extensively during Long Valley drilling. Results show that this meter is rugged, reliable, and can provide useful measurements of small differences in fluid inflow and outflow rates. By providing early indications of fluid gain or loss, improved control of blow-out and lost circulation problems during geothermal drilling can be expected. In the area of downhole tools for lost circulation control, the concept of a downhole injector for injecting a two-component, fast-setting cementitious mud was developed. DOE filed a patent application for this concept during FY 91. The design criteria for a high-temperature potassium, uranium, thorium logging tool featuring a downhole data storage computer were established, and a request for proposals was submitted to tool development companies. The fundamental theory of acoustic telemetry in drill strings was significantly advanced through field experimentation and analysis. A new understanding of energy loss mechanisms was developed.

  17. Overview - Hard Rock Penetration

    SciTech Connect

    Dunn, James C.

    1992-03-24

    The Hard Rock Penetration program is developing technology to reduce the costs of drilling and completing geothermal wells. Current projects include: lost circulation control, rock penetration mechanics, instrumentation, and industry/DOE cost shared projects of the Geothermal Drilling Organization. Last year, a number of accomplishments were achieved in each of these areas. A new flow meter being developed to accurately measure drilling fluid outflow was tested extensively during Long Valley drilling. Results show that this meter is rugged, reliable, and can provide useful measurements of small differences in fluid inflow and outflow rates. By providing early indications of fluid gain or loss, improved control of blow-out and lost circulation problems during geothermal drilling can be expected. In the area of downhole tools for lost circulation control, the concept of a downhole injector for injecting a two-component, fast-setting cementitious mud was developed. DOE filed a patent application for this concept during FY 91. The design criteria for a high-temperature potassium, uranium, thorium logging tool featuring a downhole data storage computer were established, and a request for proposals was submitted to tool development companies. The fundamental theory of acoustic telemetry in drill strings was significantly advanced through field experimentation and analysis. A new understanding of energy loss mechanisms was developed.

  18. Overview: Hard Rock Penetration

    SciTech Connect

    Dunn, J.C.

    1992-01-01

    The Hard Rock Penetration program is developing technology to reduce the costs of drilling and completing geothermal wells. Current projects include: lost circulation control, rock penetration mechanics, instrumentation, and industry/DOE cost shared projects of the Geothermal Drilling organization. Last year, a number of accomplishments were achieved in each of these areas. A new flow meter being developed to accurately measure drilling fluid outflow was tested extensively during Long Valley drilling. Results show that this meter is rugged, reliable, and can provide useful measurements of small differences in fluid inflow and outflow rates. By providing early indications of fluid gain or loss, improved control of blow-out and lost circulation problems during geothermal drilling can be expected. In the area of downhole tools for lost circulation control, the concept of a downhole injector for injecting a two-component, fast-setting cementitious mud was developed. DOE filed a patent application for this concept during FY 91. The design criteria for a high-temperature potassium, uranium, thorium logging tool featuring a downhole data storage computer were established, and a request for proposals was submitted to tool development companies. The fundamental theory of acoustic telemetry in drill strings was significantly advanced through field experimentation and analysis. A new understanding of energy loss mechanisms was developed.

  19. Final design report for cone penetrometer platform

    SciTech Connect

    Seda, R.Y., Westinghouse Hanford

    1996-08-13

    The final design report documents the completion of the design review meetings for acceptance of the cone penetrometer from the vendor. All design comments have been dispositioned and closed. Open items dealt with completion of the safety assessment,operational procedures, operational testing and readiness review.

  20. Aerodynamic characteristics of the standard dynamics model in coning motion at Mach 0.6

    NASA Technical Reports Server (NTRS)

    Jermey, C.; Schiff, L. B.

    1985-01-01

    A wind tunnel test was conducted on the Standard Dynamics Model (a simplified generic fighter aircraft shape) undergoing coning motion at Mach 0.6. Six component force and moment data are presented for a range of angle of attack, sideslip, and coning rates. At the relatively low non-dimensional coning rate employed (omega b/2V less than or equal to 0.04), the lateral aerodynamic characteristics generally show a linear variation with coning rate.

  1. The novel, selective, brain-penetrant neuropeptide Y Y2 receptor antagonist, JNJ-31020028, tested in animal models of alcohol consumption, relapse, and anxiety.

    PubMed

    Cippitelli, Andrea; Rezvani, Amir H; Robinson, J Elliott; Eisenberg, Lindsay; Levin, Edward D; Bonaventure, Pascal; Motley, S Timothy; Lovenberg, Timothy W; Heilig, Markus; Thorsell, Annika

    2011-09-01

    Neuropeptide Y (NPY) signaling has been shown to modulate stress responses and to be involved in regulation of alcohol intake and dependence. The present study explores the possibility that blockade of NPY Y2 autoreceptors using a novel, blood-brain barrier penetrant NPY Y2 receptor antagonist, JNJ-31020028 (N-(4-{4-[2-(diethylamino)-2-oxo-1-phenylethyl]piperazin-1-yl}-3-fluorophenyl)-2-pyridin-3-ylbenzamide), may achieve a therapeutically useful activation of the NPY system in alcohol- and anxiety-related behavioral models. We examined JNJ-31020028 in operant alcohol self-administration, stress-induced reinstatement to alcohol seeking, and acute alcohol withdrawal (hangover)-induced anxiety. Furthermore, we tested its effects on voluntary alcohol consumption in a genetic animal model of alcohol preference, the alcohol-preferring (P) rat. Neither systemic (0, 15, 30, and 40 mg/kg, subcutaneously [s.c.]) nor intracerebroventricular (0.0, 0.3, and 1.0 nmol/rat) administration of JNJ-31020028 affected alcohol-reinforced lever pressing or relapse to alcohol seeking behavior following stress exposure. Also, when its effects were tested on unlimited access to alcohol in P rats, preference for alcohol solution was transiently suppressed but without affecting voluntary alcohol intake. JNJ-31020028 (15 mg/kg, s.c.) did reverse the anxiogenic effects of withdrawal from a single bolus dose of alcohol on the elevated plus-maze, confirming the anxiolytic-like properties of NPY Y2 antagonism. Our data do not support Y2 antagonism as a mechanism for reducing alcohol consumption or relapse-like behavior, but the observed effects on withdrawal-induced anxiety suggest that NPY Y2 receptor antagonists may be a putative treatment for the negative affective states following alcohol withdrawal.

  2. Development of Partial Ontogenic Resistance to Powdery Mildew in Hop Cones and Its Management Implications

    PubMed Central

    Twomey, Megan C.; Wolfenbarger, Sierra N.; Woods, Joanna L.; Gent, David H.

    2015-01-01

    Knowledge of processes leading to crop damage is central to devising rational approaches to disease management. Multiple experiments established that infection of hop cones by Podosphaera macularis was most severe if inoculation occurred within 15 to 21 days after bloom. This period of infection was associated with the most pronounced reductions in alpha acids, cone color, and accelerated maturation of cones. Susceptibility of cones to powdery mildew decreased progressively after the transition from bloom to cone development, although complete immunity to the disease failed to develop. Maturation of cone tissues was associated with multiple significant affects on the pathogen manifested as reduced germination of conidia, diminished frequency of penetration of bracts, lengthening of the latent period, and decreased sporulation. Cones challenged with P. macularis in juvenile developmental stages also led to greater frequency of colonization by a complex of saprophytic, secondary fungi. Since no developmental stage of cones was immune to powdery mildew, the incidence of powdery mildew continued to increase over time and exceeded 86% by late summer. In field experiments with a moderately susceptible cultivar, the incidence of cones with powdery mildew was statistically similar when fungicide applications were made season-long or targeted only to the juvenile stages of cone development. These studies establish that partial ontogenic resistance develops in hop cones and may influence multiple phases of the infection process and pathogen reproduction. The results further reinforce the concept that the efficacy of a fungicide program may depend largely on timing of a small number of sprays during a relatively brief period of cone development. However in practice, targeting fungicide and other management tactics to periods of enhanced juvenile susceptibility may be complicated by a high degree of asynchrony in cone development and other factors that are situation

  3. Development of partial ontogenic resistance to powdery mildew in hop cones and its management implications.

    PubMed

    Twomey, Megan C; Wolfenbarger, Sierra N; Woods, Joanna L; Gent, David H

    2015-01-01

    Knowledge of processes leading to crop damage is central to devising rational approaches to disease management. Multiple experiments established that infection of hop cones by Podosphaera macularis was most severe if inoculation occurred within 15 to 21 days after bloom. This period of infection was associated with the most pronounced reductions in alpha acids, cone color, and accelerated maturation of cones. Susceptibility of cones to powdery mildew decreased progressively after the transition from bloom to cone development, although complete immunity to the disease failed to develop. Maturation of cone tissues was associated with multiple significant affects on the pathogen manifested as reduced germination of conidia, diminished frequency of penetration of bracts, lengthening of the latent period, and decreased sporulation. Cones challenged with P. macularis in juvenile developmental stages also led to greater frequency of colonization by a complex of saprophytic, secondary fungi. Since no developmental stage of cones was immune to powdery mildew, the incidence of powdery mildew continued to increase over time and exceeded 86% by late summer. In field experiments with a moderately susceptible cultivar, the incidence of cones with powdery mildew was statistically similar when fungicide applications were made season-long or targeted only to the juvenile stages of cone development. These studies establish that partial ontogenic resistance develops in hop cones and may influence multiple phases of the infection process and pathogen reproduction. The results further reinforce the concept that the efficacy of a fungicide program may depend largely on timing of a small number of sprays during a relatively brief period of cone development. However in practice, targeting fungicide and other management tactics to periods of enhanced juvenile susceptibility may be complicated by a high degree of asynchrony in cone development and other factors that are situation-dependent.

  4. Microcomputed tomography and shock microdeformation studies on shatter cones

    NASA Astrophysics Data System (ADS)

    Zaag, Patrice Tristan; Reimold, Wolf Uwe; Hipsley, Christy Anna

    2016-08-01

    One of the aspects of impact cratering that are still not fully understood is the formation of shatter cones and related fracturing phenomena. Yet, shatter cones have been applied as an impact-diagnostic criterion for decades without the role of shock waves and target rock defects in their formation having been elucidated ever. We have tested the application of the nondestructive microcomputed tomography (μCT) method to visualize the interior of shatter cones in order to possibly resolve links between fracture patterns and shatter cone surface features (striations and intervening "valleys"). Shatter-coned samples from different impact sites and in different lithologies were investigated for their μCT suitability, with a shatter cone in sandstone from the Serra da Cangalha impact structure (Brazil) remaining as the most promising candidate because of the fracture resolution achieved. To validate the obtained CT data, the scanned specimen was cut into three orthogonal sets of thin sections. Scans with 13 μm resolution were obtained. μCT scans and microscopic analysis unraveled an orientation of subplanar fractures and related fluid inclusion trails, and planar fracture (PF) orientations in the interior of shatter cones. Planar deformation features (PDF) were observed predominantly near the shatter cone surface. Previously undescribed varieties of feather features (FF), in the form of lamellae emanating from curviplanar and curved fractures, as well as an "arrowhead"-like FF development with microlamellae originating from both sides of a PF, were observed. The timing of shatter cone formation was investigated by establishing temporal relations to the generation of various shock microscopic effects. Shatter cones are, thus, generated post- or syn-formation of PF, FF, subplanar fractures, and PDF. The earliest possible time for shatter cone formation is during the late stage of the compressional phase, that is, shock wave passage, of an impact event.

  5. Individual variations in human cone photoreceptor packing density

    PubMed Central

    Chui, Toco Yuen Ping; Song, HongXin; Burns, Stephen A.

    2008-01-01

    PURPOSE To measure the variation in human cone photoreceptor packing density across the retina both within an individual and between individuals with different refractive errors. METHODS A high resolution adaptive optics scanning laser ophthalmoscope was used to image the cones of eleven human eyes. Five emmetropes and six myopes were tested (+0.50D to -7.50D). For each subject we obtained four approximately 10 degree by 1.5 degree strips of cone images. Each strip started at the fovea, and proceeded towards the periphery along the four primary meridians. The position of each cone within the sampling windows was digitized manually by the investigator. From these cone counts, the density of cones was calculated for a set of fixed distances from the fovea for locations throughout the image. RESULTS Cone photoreceptor packing density decreased from 27,712 cells/mm2 to 7,070 cells/mm2 from the retinal eccentricity of 0.30mm to 3.40mm along the superior meridian in five emmetropic eyes. Cone photoreceptor packing density in cells/mm2 was significantly lower in myopic eyes than in emmetropic eyes. At a given location, there was considerable individual variation in cone photoreceptor packing density, although more than 20% of the variance could be accounted for by differences in axial length. CONCLUSIONS Our results provide a baseline analysis of individual difference in cone photoreceptor packing density in healthy human eyes. As predicted by retinal stretching models, cone photoreceptor packing density is lower in highly myopic eyes than in emmetropic eyes. PMID:18552378

  6. Horizontal Cells of the Primate Retina: Cone Specificity Without Spectral Opponency

    NASA Astrophysics Data System (ADS)

    Dacey, Dennis M.; Lee, Barry B.; Stafford, Donna K.; Pokorny, Joel; Smith, Vivianne C.

    1996-02-01

    The chromatic dimensions of human color vision have a neural basis in the retina. Ganglion cells, the output neurons of the retina, exhibit spectral opponency; they are excited by some wavelengths and inhibited by others. The hypothesis that the opponent circuitry emerges from selective connections between horizontal cell interneurons and cone photoreceptors sensitive to long, middle, and short wavelengths (L-, M-, and S-cones) was tested by physiologically and anatomically characterizing cone connections of horizontal cell mosaics in macaque monkeys. H1 horizontal cells received input only from L- and M-cones, whereas H2 horizontal cells received a strong input from S-cones and a weaker input from L- and M-cones. All cone inputs were the same sign, and both horizontal cell types lacked opponency. Despite cone type selectivity, the horizontal cell cannot be the locus of an opponent transformation in primates, including humans.

  7. Light cone matrix product

    SciTech Connect

    Hastings, Matthew B

    2009-01-01

    We show how to combine the light-cone and matrix product algorithms to simulate quantum systems far from equilibrium for long times. For the case of the XXZ spin chain at {Delta} = 0.5, we simulate to a time of {approx} 22.5. While part of the long simulation time is due to the use of the light-cone method, we also describe a modification of the infinite time-evolving bond decimation algorithm with improved numerical stability, and we describe how to incorporate symmetry into this algorithm. While statistical sampling error means that we are not yet able to make a definite statement, the behavior of the simulation at long times indicates the appearance of either 'revivals' in the order parameter as predicted by Hastings and Levitov (e-print arXiv:0806.4283) or of a distinct shoulder in the decay of the order parameter.

  8. Seismic Site Classification and Correlation between Standard Penetration Test N Value and Shear Wave Velocity for Lucknow City in Indo-Gangetic Basin

    NASA Astrophysics Data System (ADS)

    Anbazhagan, P.; Kumar, Abhishek; Sitharam, T. G.

    2013-03-01

    Subsurface lithology and seismic site classification of Lucknow urban center located in the central part of the Indo-Gangetic Basin (IGB) are presented based on detailed shallow subsurface investigations and borehole analysis. These are done by carrying out 47 seismic surface wave tests using multichannel analysis of surface waves (MASW) and 23 boreholes drilled up to 30 m with standard penetration test (SPT) N values. Subsurface lithology profiles drawn from the drilled boreholes show low- to medium-compressibility clay and silty to poorly graded sand available till depth of 30 m. In addition, deeper boreholes (depth >150 m) were collected from the Lucknow Jal Nigam (Water Corporation), Government of Uttar Pradesh to understand deeper subsoil stratification. Deeper boreholes in this paper refer to those with depth over 150 m. These reports show the presence of clay mix with sand and Kankar at some locations till a depth of 150 m, followed by layers of sand, clay, and Kankar up to 400 m. Based on the available details, shallow and deeper cross-sections through Lucknow are presented. Shear wave velocity (SWV) and N-SPT values were measured for the study area using MASW and SPT testing. Measured SWV and N-SPT values for the same locations were found to be comparable. These values were used to estimate 30 m average values of N-SPT ( N 30) and SWV ( V {s/30}) for seismic site classification of the study area as per the National Earthquake Hazards Reduction Program (NEHRP) soil classification system. Based on the NEHRP classification, the entire study area is classified into site class C and D based on V {s/30} and site class D and E based on N 30. The issue of larger amplification during future seismic events is highlighted for a major part of the study area which comes under site class D and E. Also, the mismatch of site classes based on N 30 and V {s/30} raises the question of the suitability of the NEHRP classification system for the study region. Further, 17 sets

  9. Shatter cones: Diagnostic impact signatures

    NASA Technical Reports Server (NTRS)

    Mchone, J. F.; Dietz, R. S.

    1988-01-01

    Uniquely fractured target rocks known as shatter cones are associated with more than one half the world's 120 or so presently known impact structures. Shatter cones are a form of tensile rock failure in which a positive conical plug separates from a negative outer cup or mold and delicate ornaments radiating from an apex are preserved on surfaces of both portions. Although distinct, shatter cones are sometimes confused with other striated geologic features such as ventifacts, stylolites, cone-in-cone, slickensides, and artificial blast plumes. Complete cones or solitary cones are rare, occurrences are usually as swarms in thoroughly fractured rock. Shatter cones may form in a zone where an expanding shock wave propagating through a target decays to form an elastic wave. Near this transition zone, the expanding primary wave may strike a pebble or other inhomogeneity whose contrasting transmission properties produce a scattered secondary wave. Interference between primary and secondary scattered waves produce conical stress fields with axes perpendicular to the plane of an advancing shock front. This model supports mechanism capable of producing such shatter cone properties as orientation, apical clasts, lithic dependence, and shock pressure zonation. Although formational mechanics are still poorly understood, shatter cones have become the simplest geologic field criterion for recognizing astroblemes (ancient terrestrial impact structures).

  10. Shatter cones: Diagnostic impact signatures

    NASA Astrophysics Data System (ADS)

    McHone, J. F.; Dietz, R. S.

    Uniquely fractured target rocks known as shatter cones are associated with more than one half the world's 120 or so presently known impact structures. Shatter cones are a form of tensile rock failure in which a positive conical plug separates from a negative outer cup or mold and delicate ornaments radiating from an apex are preserved on surfaces of both portions. Although distinct, shatter cones are sometimes confused with other striated geologic features such as ventifacts, stylolites, cone-in-cone, slickensides, and artificial blast plumes. Complete cones or solitary cones are rare, occurrences are usually as swarms in thoroughly fractured rock. Shatter cones may form in a zone where an expanding shock wave propagating through a target decays to form an elastic wave. Near this transition zone, the expanding primary wave may strike a pebble or other inhomogeneity whose contrasting transmission properties produce a scattered secondary wave. Interference between primary and secondary scattered waves produce conical stress fields with axes perpendicular to the plane of an advancing shock front. This model supports mechanism capable of producing such shatter cone properties as orientation, apical clasts, lithic dependence, and shock pressure zonation. Although formational mechanics are still poorly understood, shatter cones have become the simplest geologic field criterion for recognizing astroblemes (ancient terrestrial impact structures).

  11. Chemical penetration enhancers.

    PubMed

    Newton, Stephen J

    2013-01-01

    Chemical penetration enhancers are utilized in topical preparations as a method for enhancing permeation of drugs across the skin. In particular, they are utilized for transdermal delivery of medications in an attempt to produce a systemic response, to avoid first-pass metabolism, and to decrease the gastrointestinal transit time observed with oral medications. A review of the selection of chemical penetration enhancers, their mechanism of action, the most common chemical penetration enhancers in each class, and alternatives will be discussed in detail.

  12. Evaluation of nano- and submicron particle penetration through ten nonwoven fabrics using a wind-driven approach.

    PubMed

    Gao, Pengfei; Jaques, Peter A; Hsiao, Ta-Chih; Shepherd, Angie; Eimer, Benjamin C; Yang, Mengshi; Miller, Adam; Gupta, Bhupender; Shaffer, Ronald

    2011-01-01

    Existing face mask and respirator test methods draw particles through materials under vacuum to measure particle penetration. However, these filtration-based methods may not simulate conditions under which protective clothing operates in the workplace, where airborne particles are primarily driven by wind and other factors instead of being limited to a downstream vacuum. This study was focused on the design and characterization of a method simulating typical wind-driven conditions for evaluating the performance of materials used in the construction of protective clothing. Ten nonwoven fabrics were selected, and physical properties including fiber diameter, fabric thickness, air permeability, porosity, pore volume, and pore size were determined. Each fabric was sealed flat across the wide opening of a cone-shaped penetration cell that was then housed in a recirculation aerosol wind tunnel. The flow rate naturally driven by wind through the fabric was measured, and the sampling flow rate of the Scanning Mobility Particle Sizer used to measure the downstream particle size distribution and concentrations was then adjusted to minimize filtration effects. Particle penetration levels were measured under different face velocities by the wind-driven method and compared with a filtration-based method using the TSI 3160 automated filter tester. The experimental results show that particle penetration increased with increasing face velocity, and penetration also increased with increasing particle size up to about 300 to 500 nm. Penetrations measured by the wind-driven method were lower than those obtained with the filtration method for most of the fabrics selected, and the relative penetration performances of the fabrics were very different due to the vastly different pore structures.

  13. Session: Hard Rock Penetration

    SciTech Connect

    Tennyson, George P. Jr.; Dunn, James C.; Drumheller, Douglas S.; Glowka, David A.; Lysne, Peter

    1992-01-01

    This session at the Geothermal Energy Program Review X: Geothermal Energy and the Utility Market consisted of five presentations: ''Hard Rock Penetration - Summary'' by George P. Tennyson, Jr.; ''Overview - Hard Rock Penetration'' by James C. Dunn; ''An Overview of Acoustic Telemetry'' by Douglas S. Drumheller; ''Lost Circulation Technology Development Status'' by David A. Glowka; ''Downhole Memory-Logging Tools'' by Peter Lysne.

  14. Follicular penetration and targeting.

    PubMed

    Lademann, Jürgen; Otberg, Nina; Jacobi, Ute; Hoffman, Robert M; Blume-Peytavi, Ulrike

    2005-12-01

    In the past, intercellular penetration was assumed to be the most important penetration pathway of topically applied substances. First hints that follicular penetration needs to be taken into consideration were confirmed by recent investigations, presented during the workshop "Follicular Penetration and Targeting" at the 4th Intercontinental Meeting of Hair Research Societies", in Berlin 2004. Hair follicles represent an efficient reservoir for the penetration of topically applied substances with subsequent targeting of distinct cell populations, e.g., nestin-expressing follicular bulge cells. The volume of this reservoir can be determined by differential stripping technology. The follicular penetration processes are significantly influenced by the state of the follicular infundibulum; recent experimental investigations could demonstrate that it is essential to distinguish between open and closed hair follicles. Topically applied substances can only penetrate into open hair follicle. Knowledge of follicular penetration is of high clinical relevance for functional targeting of distinct follicular regions. Human hair follicles show a hair-cycle-dependent variation of the dense neuronal and vascular network. Moreover, during hair follicle cycling with initiation of anagen, newly formed vessels occur. Thus, the potential of nestin-expressing hair follicle stem cells to form neurons and blood vessels was investigated.

  15. Development of a Deep-Penetrating, Compact Geothermal Heat Flow System for Robotic Lunar Geophysical Missions

    NASA Technical Reports Server (NTRS)

    Nagihara, Seiichi; Zacny, Kris; Hedlund, Magnus; Taylor, Patrick T.

    2012-01-01

    Geothermal heat flow measurements are a high priority for the future lunar geophysical network missions recommended by the latest Decadal Survey of the National Academy. Geothermal heat flow is obtained as a product of two separate measurements of geothermal gradient and thermal conductivity of the regolith/soil interval penetrated by the instrument. The Apollo 15 and 17 astronauts deployed their heat flow probes down to 1.4-m and 2.3-m depths, respectively, using a rotary-percussive drill. However, recent studies show that the heat flow instrument for a lunar mission should be capable of excavating a 3-m deep hole to avoid the effect of potential long-term changes of the surface thermal environment. For a future robotic geophysical mission, a system that utilizes a rotary/percussive drill would far exceed the limited payload and power capacities of the lander/rover. Therefore, we are currently developing a more compact heat flow system that is capable of 3-m penetration. Because the grains of lunar regolith are cohesive and densely packed, the previously proposed lightweight, internal hammering systems (the so-called moles ) are not likely to achieve the desired deep penetration. The excavation system for our new heat flow instrumentation utilizes a stem which winds out of a pneumatically driven reel and pushes its conical tip into the regolith. Simultaneously, gas jets, emitted from the cone tip, loosen and blow away the soil. Lab tests have demonstrated that this proboscis system has much greater excavation capability than a mole-based heat flow system, while it weighs about the same. Thermal sensors are attached along the stem and at the tip of the penetrating cone. Thermal conductivity is measured at the cone tip with a short (1- to 1.5-cm long) needle sensor containing a resistance temperature detector (RTD) and a heater wire. When it is inserted into the soil, the heater is activated. Thermal conductivity of the soil is obtained from the rate of temperature

  16. Internal Reflection Sensor for the Cone Penetrometer

    SciTech Connect

    Job Bello

    1998-05-29

    The objectives of this project are to design, assemble, test, and demonstrate a prototype Internal Reflection Sensor (IRS) for the cone penetrometer. The sensor will ultimately be deployed during site characterization with the goal of providing real-time, in situ detection of NonAqueous Phase Liquids (NAPLs) in the subsurface. In the first phase of this program, we have designed and assembled an IRS module that interfaces directly to a standard cone penetrometer system. Laboratory tests demonstrated that the sensor responds in real-time to a wide variety of free phase NAPLs without interference from natural materials such as water and soil of various types or dissolved contaminants. In a preliminary field test, the sensor was able to locate NAPLs at thin, discrete depths in a soil test pit when deployed with a cone penetrometer. Ruggedness of the device was tested with a series of penetrometer pushes to the depth of refusal at a clean location. There was no visible damage to the sensor and its performance did not change in the course of these experiments. Based on the successes of the Phase I program, it is recommended that the project proceed to full-scale demonstration in Phase II.

  17. Dynamic Site Characterization and Correlation of Shear Wave Velocity with Standard Penetration Test ` N' Values for the City of Agartala, Tripura State, India

    NASA Astrophysics Data System (ADS)

    Sil, Arjun; Sitharam, T. G.

    2014-08-01

    Seismic site characterization is the basic requirement for seismic microzonation and site response studies of an area. Site characterization helps to gauge the average dynamic properties of soil deposits and thus helps to evaluate the surface level response. This paper presents a seismic site characterization of Agartala city, the capital of Tripura state, in the northeast of India. Seismically, Agartala city is situated in the Bengal Basin zone which is classified as a highly active seismic zone, assigned by Indian seismic code BIS-1893, Indian Standard Criteria for Earthquake Resistant Design of Structures, Part-1 General Provisions and Buildings. According to the Bureau of Indian Standards, New Delhi (2002), it is the highest seismic level (zone-V) in the country. The city is very close to the Sylhet fault (Bangladesh) where two major earthquakes ( M w > 7) have occurred in the past and affected severely this city and the whole of northeast India. In order to perform site response evaluation, a series of geophysical tests at 27 locations were conducted using the multichannel analysis of surface waves (MASW) technique, which is an advanced method for obtaining shear wave velocity ( V s) profiles from in situ measurements. Similarly, standard penetration test (SPT-N) bore log data sets have been obtained from the Urban Development Department, Govt. of Tripura. In the collected data sets, out of 50 bore logs, 27 were selected which are close to the MASW test locations and used for further study. Both the data sets ( V s profiles with depth and SPT-N bore log profiles) have been used to calculate the average shear wave velocity ( V s30) and average SPT-N values for the upper 30 m depth of the subsurface soil profiles. These were used for site classification of the study area recommended by the National Earthquake Hazard Reduction Program (NEHRP) manual. The average V s30 and SPT-N classified the study area as seismic site class D and E categories, indicating that

  18. The Holographic Entropy Cone

    SciTech Connect

    Bao, Ning; Nezami, Sepehr; Ooguri, Hirosi; Stoica, Bogdan; Sully, James; Walter, Michael

    2015-09-21

    We initiate a systematic enumeration and classification of entropy inequalities satisfied by the Ryu-Takayanagi formula for conformal field theory states with smooth holographic dual geometries. For 2, 3, and 4 regions, we prove that the strong subadditivity and the monogamy of mutual information give the complete set of inequalities. This is in contrast to the situation for generic quantum systems, where a complete set of entropy inequalities is not known for 4 or more regions. We also find an infinite new family of inequalities applicable to 5 or more regions. The set of all holographic entropy inequalities bounds the phase space of Ryu-Takayanagi entropies, defining the holographic entropy cone. We characterize this entropy cone by reducing geometries to minimal graph models that encode the possible cutting and gluing relations of minimal surfaces. We find that, for a fixed number of regions, there are only finitely many independent entropy inequalities. To establish new holographic entropy inequalities, we introduce a combinatorial proof technique that may also be of independent interest in Riemannian geometry and graph theory.

  19. The Holographic Entropy Cone

    DOE PAGES

    Bao, Ning; Nezami, Sepehr; Ooguri, Hirosi; ...

    2015-09-21

    We initiate a systematic enumeration and classification of entropy inequalities satisfied by the Ryu-Takayanagi formula for conformal field theory states with smooth holographic dual geometries. For 2, 3, and 4 regions, we prove that the strong subadditivity and the monogamy of mutual information give the complete set of inequalities. This is in contrast to the situation for generic quantum systems, where a complete set of entropy inequalities is not known for 4 or more regions. We also find an infinite new family of inequalities applicable to 5 or more regions. The set of all holographic entropy inequalities bounds the phasemore » space of Ryu-Takayanagi entropies, defining the holographic entropy cone. We characterize this entropy cone by reducing geometries to minimal graph models that encode the possible cutting and gluing relations of minimal surfaces. We find that, for a fixed number of regions, there are only finitely many independent entropy inequalities. To establish new holographic entropy inequalities, we introduce a combinatorial proof technique that may also be of independent interest in Riemannian geometry and graph theory.« less

  20. Kinematics of Cone-In-Cone Growth, with Implications for Timing and Formation Mechanism

    NASA Astrophysics Data System (ADS)

    Hooker, J. N.; Cartwright, J. A.

    2015-12-01

    Cone-in-cone is an enigmatic structure. Similar to many fibrous calcite veins, cone-in-cone is generally formed of calcite and present in bedding-parallel vein-like accumulations within fine-grained rocks. Unlike most fibrous veins, cone-in-cone contains conical inclusions of host-rock material, creating nested, parallel cones throughout. A long-debated aspect of cone-in-cone structures is whether the calcite precipitated with its conical form (primary cone-in-cone), or whether the cones formed afterwards (secondary cone-in-cone). Trace dolomite within a calcite cone-in-cone structure from the Cretaceous of Jordan supports the primary hypothesis. The host sediment is a siliceous mud containing abundant rhombohedral dolomite grains. Dolomite rhombohedra are also distributed throughout the cone-in-cone. The rhombohedra within the cones are randomly oriented yet locally have dolomite overgrowths having boundaries that are aligned with calcite fibers. Evidence that dolomite co-precipitated with calcite, and did not replace calcite, includes (i) preferential downward extension of dolomite overgrowths, in the presumed growth-direction of the cone-in-cone, and (ii) planar, vertical borders between dolomite crystals and calcite fibers. Because dolomite overgrows host-sediment rhombohedra and forms fibers within the cones, it follows that the host-sediment was included within the growing cone-in-cone as the calcite precipitated, and not afterward. The host-sediment was not injected into the cone-in-cone along fractures, as the secondary-origin hypothesis suggests. This finding implies that cone-in-cone in general does not form over multiple stages, and thus has greater potential to preserve the chemical signature of its original precipitation. Because cone-in-cone likely forms before complete lithification of the host, and because the calcite displaces the host material against gravity, this chemical signature can preserve information about early overpressures in fine

  1. Making An Impact: Shatter Cones

    ERIC Educational Resources Information Center

    Blank, Lisa M.; Plautz, Michael R.; Crews, Jeffrey W.

    2004-01-01

    In 1990, a group of geologists discovered a large number of shatter cones in southwestern Montana. Shatter cones are a type of metamorphosed rock often found in impact structures (the remains of a crater after a meteor impact and years of Earth activity). Scientists have discovered only 168 impact craters around the world. If rocks could talk,…

  2. An Industry/DOE Program to Develop and Benchmark Advanced Diamond Product Drill Bits and HP/HT Drilling Fluids to Significantly Improve Rates of Penetration

    SciTech Connect

    TerraTek

    2007-06-30

    A deep drilling research program titled 'An Industry/DOE Program to Develop and Benchmark Advanced Diamond Product Drill Bits and HP/HT Drilling Fluids to Significantly Improve Rates of Penetration' was conducted at TerraTek's Drilling and Completions Laboratory. Drilling tests were run to simulate deep drilling by using high bore pressures and high confining and overburden stresses. The purpose of this testing was to gain insight into practices that would improve rates of penetration and mechanical specific energy while drilling under high pressure conditions. Thirty-seven test series were run utilizing a variety of drilling parameters which allowed analysis of the performance of drill bits and drilling fluids. Five different drill bit types or styles were tested: four-bladed polycrystalline diamond compact (PDC), 7-bladed PDC in regular and long profile, roller-cone, and impregnated. There were three different rock types used to simulate deep formations: Mancos shale, Carthage marble, and Crab Orchard sandstone. The testing also analyzed various drilling fluids and the extent to which they improved drilling. The PDC drill bits provided the best performance overall. The impregnated and tungsten carbide insert roller-cone drill bits performed poorly under the conditions chosen. The cesium formate drilling fluid outperformed all other drilling muds when drilling in the Carthage marble and Mancos shale with PDC drill bits. The oil base drilling fluid with manganese tetroxide weighting material provided the best performance when drilling the Crab Orchard sandstone.

  3. Optimization of brain penetrant 11β-hydroxysteroid dehydrogenase type I inhibitors and in vivo testing in diet-induced obese mice.

    PubMed

    Goldberg, Frederick W; Dossetter, Alexander G; Scott, James S; Robb, Graeme R; Boyd, Scott; Groombridge, Sam D; Kemmitt, Paul D; Sjögren, Tove; Gutierrez, Pablo Morentin; deSchoolmeester, Joanne; Swales, John G; Turnbull, Andrew V; Wild, Martin J

    2014-02-13

    11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1) has been widely considered by the pharmaceutical industry as a target to treat metabolic syndrome in type II diabetics. We hypothesized that central nervous system (CNS) penetration might be required to see efficacy. Starting from a previously reported pyrimidine compound, we removed hydrogen-bond donors to yield 3, which had modest CNS penetration. More significant progress was achieved by changing the core to give 40, which combines good potency and CNS penetration. Compound 40 was dosed to diet-induced obese (DIO) mice and gave excellent target engagement in the liver and high free exposures of drug, both peripherally and in the CNS. However, no body weight reduction or effects on glucose or insulin were observed in this model. Similar data were obtained with a structurally diverse thiazole compound 51. This work casts doubt on the hypothesis that localized tissue modulation of 11β-HSD1 activity alleviates metabolic syndrome.

  4. Ichthyotoxicity caused by marine cone snail venoms?

    PubMed

    Mebs, Dietrich; Kauferstein, Silke

    2005-09-01

    Ten venoms from marine cone snails were tested for ichthyotoxic effects on zebra fish (Brachydanio rerio) when added to the water. Only two venoms, from Conus capitaneus and Conus episcopatus, produced lethal effects at high concentrations (50-300 microg/ml) within 20-90 min. No sedative or hypnotic symptoms were observed. The experiments confirm that Conus venoms exert a quick and prompt activity only by parenteral injection into the prey as it is performed by the snail.

  5. Laser range profile of cones

    NASA Astrophysics Data System (ADS)

    Zhou, Wenzhen; Gong, Yanjun; Wang, Mingjun; Gong, Lei

    2016-10-01

    technology. Laser one-dimensional range profile can reflect the characteristics of the target shape and surface material. These techniques were motivated by applications of laser radar to target discrimination in ballistic missile defense. The radar equation of pulse laser about cone is given in this paper. This paper demonstrates the analytical model of laser one-dimensional range profile of cone based on the radar equation of the pulse laser. Simulations results of laser one-dimensional range profiles of some cones are given. Laser one-dimensional range profiles of cone, whose surface material with diffuse lambertian reflectance, is given in this paper. Laser one-dimensional range profiles of cone, whose surface mater with diffuse materials whose retroreflectance can be modeled closely with an exponential term that decays with increasing incidence angles, is given in this paper. Laser one-dimensional range profiles of different pulse width of cone is given in this paper. The influences of surface material, pulse width, attitude on the one-dimensional range are analyzed. The laser two-dimensional range profile is two-dimensional scattering imaging of pulse laser of target. The two-dimensional range profile of roughness target can provide range resolved information. An analytical model of two-dimensional laser range profile of cone is proposed. The simulations of two-dimensional laser range profiles of some cones are given. Laser two-dimensional range profiles of cone, whose surface mater with diffuse lambertian reflectance, is given in this paper. Laser two-dimensional range profiles of cone, whose surface mater with diffuse materials whose retroreflectance can be modeled closely with an exponential term that decays with increasing incidence angles, is given in this paper. The influence of pulse width, surface material on laser two-dimensional range profile is analyzed. Laser one-dimensional range profile and laser two-dimensional range profile are called as laser

  6. Advanced Penetrator Materials

    DTIC Science & Technology

    2007-11-02

    development • Uranium (U-V-X) Alloys • Alternative Matrix (adiabatic shearing) Tungsten Composites • Amorphous and Nanocrystalline Alloys • Severe Deformation...WIDER CHANNEL • MUSHROOM NOSE • LESS DEPTH • REMAINS SHARP • NARROW CHANNEL • DEEPER CAVITY TUNGSTEN HEAVY ALLOY U-3/4 Ti ALLOY U-8Mo ALLOYW-Ni-Fe...martensite (from Staker)(from Staker) • U-V alloys have the potential to maintain penetration capability while reducing penetrator density and mass. Tungsten

  7. Clinical S-cone ERG recording with a commercial hand-held full-field stimulator.

    PubMed

    Marmor, Michael F; Cabael, Lorella; Shukla, Shefalee; Hwang, John C; Marcus, Mira

    2004-07-01

    Our purpose was to explore S-cone ERG protocols for a commercial full-field hand-held stimulator that contains colored LEDs, and to see whether the test would be useful as a part of routine ERG testing. S-cone responses were elicited by blue flashes over a longer-wavelength background. With the standard stimulator containing blue (461 nm), green (513 nm) and red (652 nm) LEDs, we were unable to obtain satisfactory responses. Reproducible S-cone ERGs were obtained with a stimulator that had been custom-fitted with shorter-wavelength blue (440 nm) LEDs for stimulation, and orange (590 nm) LEDs for background adaptation. S-cone responses took only a few minutes to record, and the typical waveform showed a slow peak at 45-50 ms with amplitude 3-9 microV, but ranging from 0 microV to more than 10 microV. Larger waves appeared in a patient with enhanced S-cone syndrome. S-cone responses could also be obtained with an alternating blue-orange flicker protocol. We added the S-cone response to our regular ERG protocol for a number of months. Although most normal subjects and patients showed recognizable S-cone responses with this stimulator, the amplitudes were small and there was too much variability to make the technique effective for routine clinical testing. In general, the S-cone responses followed the standard cone ERG responses in disease.

  8. Reflection and Ground Penetrating Radar for Environmental Site Characterization

    SciTech Connect

    Steeples, Don W.

    2000-06-01

    (1) To examine the complementary site-characterization capabilities of modern, three-component shallow seismic reflection (SSR) techniques and ground-penetrating radar (GPR) methods at depths ranging from 2 to 8 m at an existing test site; (2) To demonstrate the usefulness of the two methods when used in concert to characterize, in three dimensions, the cone of depression of a pumping well that will serve as a proxy site for fluid-flow at an actual, polluted site; (3) To use the site as an outdoor mesoscale laboratory to validate existing three-dimensional ground-penetrating radar and seismic-reflection computer models developed at the University of Kansas. To do this, seismic and GPR data are being collected along the same line(s) and within the same depth range. The principal investigators selected a site in central Kansas as a primary location. Although the site itself is not environmentally sensitive, the area offers attributes that are particularly useful for this research and allow the site to serve as a proxy for areas that are contaminated. As part of an effort to evaluate the strengths of each method, the seismic and GPR surveys have been repeated on a seasonal basis to establish how the complementary information obtained varies over time. Because the water table fluctuates seasonally at this site, variations in the two types of data over time also can be observed. Such noninvasive, in-situ methods of identifying and characterizing the hydrologic flow regimes at contaminated sites support the prospect of developing effective, cost-conscious cleanup strategies in the future.

  9. Surface penetrators for planetary exploration: Science rationale and development program

    NASA Technical Reports Server (NTRS)

    Murphy, J. P.; Reynolds, R. T.; Blanchard, M. B.; Clanton, U. S.

    1981-01-01

    Work on penetrators for planetary exploration is summarized. In particular, potential missions, including those to Mars, Mercury, the Galilean satellites, comets, and asteroids are described. A baseline penetrator design for the Mars mission is included, as well as potential instruments and their status in development. Penetration tests in soft soil and basalt to study material eroded from the penetrator; changes in the structure, composition, and physical properties of the impacted soil; seismic coupling; and penetrator deflection caused by impacting rocks, are described. Results of subsystem studies and tests are given for design of entry decelerators, high-g components, thermal control, data acquisition, and umbilical cable deployment.

  10. Conifer ovulate cones accumulate pollen principally by simple impaction

    PubMed Central

    Cresswell, James E.; Henning, Kevin; Pennel, Christophe; Lahoubi, Mohamed; Patrick, Michael A.; Young, Phillipe G.; Tabor, Gavin R.

    2007-01-01

    In many pine species (Family Pinaceae), ovulate cones structurally resemble a turbine, which has been widely interpreted as an adaptation for improving pollination by producing complex aerodynamic effects. We tested the turbine interpretation by quantifying patterns of pollen accumulation on ovulate cones in a wind tunnel and by using simulation models based on computational fluid dynamics. We used computer-aided design and computed tomography to create computational fluid dynamics model cones. We studied three species: Pinus radiata, Pinus sylvestris, and Cedrus libani. Irrespective of the approach or species studied, we found no evidence that turbine-like aerodynamics made a significant contribution to pollen accumulation, which instead occurred primarily by simple impaction. Consequently, we suggest alternative adaptive interpretations for the structure of ovulate cones. PMID:17986613

  11. Shape measurement and vibration analysis of moving speaker cone

    NASA Astrophysics Data System (ADS)

    Zhang, Qican; Liu, Yuankun; Lehtonen, Petri

    2014-06-01

    Surface three-dimensional (3-D) shape information is needed for many fast processes such as structural testing of material, standing waves on loudspeaker cone, etc. Usually measurement is done from limited number of points using electrical sensors or laser distance meters. Fourier Transform Profilometry (FTP) enables fast shape measurement of the whole surface. Method is based on angled sinusoidal fringe pattern projection and image capturing. FTP requires only one image of the deformed fringe pattern to restore the 3-D shape of the measured object, which makes real-time or dynamic data processing possible. In our experiment the method was used for loudspeaker cone distortion measurement in dynamic conditions. For sound quality issues it is important that the whole cone moves in same phase and there are no partial waves. Our imaging resolution was 1280x1024 pixels and frame rate was 200 fps. Using our setup we found unwanted spatial waves in our sample cone.

  12. Conifer ovulate cones accumulate pollen principally by simple impaction.

    PubMed

    Cresswell, James E; Henning, Kevin; Pennel, Christophe; Lahoubi, Mohamed; Patrick, Michael A; Young, Phillipe G; Tabor, Gavin R

    2007-11-13

    In many pine species (Family Pinaceae), ovulate cones structurally resemble a turbine, which has been widely interpreted as an adaptation for improving pollination by producing complex aerodynamic effects. We tested the turbine interpretation by quantifying patterns of pollen accumulation on ovulate cones in a wind tunnel and by using simulation models based on computational fluid dynamics. We used computer-aided design and computed tomography to create computational fluid dynamics model cones. We studied three species: Pinus radiata, Pinus sylvestris, and Cedrus libani. Irrespective of the approach or species studied, we found no evidence that turbine-like aerodynamics made a significant contribution to pollen accumulation, which instead occurred primarily by simple impaction. Consequently, we suggest alternative adaptive interpretations for the structure of ovulate cones.

  13. Ejecta evolution during cone impact

    NASA Astrophysics Data System (ADS)

    Marston, Jeremy; Vakarelski, Ivan; Thoroddsen, Sigurdur

    2013-11-01

    We present results from an experimental study of the impact of conical shaped bodies into a pool of liquid. By varying the cone angle, impact speed and liquid physical properties, we examine a broad parameter space and seek to find conditions when self-similarity can be observed during this phenomena. We use high-speed imaging to capture the early-time motion of the liquid ejecta which emanates from the tip of the cone and travels up along the cone surface. Surprisingly, we find that the detachment of the ejecta can be simply described by air entrainment relationships derived from coating experiments.

  14. Transonic Flow Past Cone Cylinders

    NASA Technical Reports Server (NTRS)

    Solomon, George E

    1955-01-01

    Experimental results are presented for transonic flow post cone-cylinder, axially symmetric bodies. The drag coefficient and surface Mach number are studied as the free-stream Mach number is varied and, wherever possible, the experimental results are compared with theoretical predictions. Interferometric results for several typical flow configurations are shown and an example of shock-free supersonic-to-subsonic compression is experimentally demonstrated. The theoretical problem of transonic flow past finite cones is discussed briefly and an approximate solution of the axially symmetric transonic equations, valid for a semi-infinite cone, is presented.

  15. Design and testing of Ground Penetrating Radar equipment dedicated for civil engineering applications: ongoing activities in Working Group 1 of COST Action TU1208

    NASA Astrophysics Data System (ADS)

    Pajewski, Lara; Manacorda, Guido; Persico, Raffaele

    2015-04-01

    This work aims at presenting the ongoing research activities carried out in Working Group 1 'Novel GPR instrumentation' of the COST (European COoperation in Science and Technology) Action TU1208 'Civil Engineering Applications of Ground Penetrating Radar' (www.GPRadar.eu). The principal goal of the COST Action TU1208 is to exchange and increase scientific-technical knowledge and experience of GPR techniques in civil engineering, simultaneously promoting throughout Europe the effective use of this safe and non-destructive technique in the monitoring of infrastructures and structures. Working Group 1 (WG1) of the Action focuses on the development of innovative GPR equipment dedicated for civil engineering applications. It includes three Projects. Project 1.1 is focused on the 'Design, realisation and optimisation of innovative GPR equipment for the monitoring of critical transport infrastructures and buildings, and for the sensing of underground utilities and voids.' Project 1.2 is concerned with the 'Development and definition of advanced testing, calibration and stability procedures and protocols, for GPR equipment.' Project 1.3 deals with the 'Design, modelling and optimisation of GPR antennas.' During the first year of the Action, WG1 Members coordinated between themselves to address the state of the art and open problems in the scientific fields identified by the above-mentioned Projects [1, 2]. In carrying our this work, the WG1 strongly benefited from the participation of IDS Ingegneria dei Sistemi, one of the biggest GPR manufacturers, as well as from the contribution of external experts as David J. Daniels and Erica Utsi, sharing with the Action Members their wide experience on GPR technology and methodology (First General Meeting, July 2013). The synergy with WG2 and WG4 of the Action was useful for a deep understanding of the problems, merits and limits of available GPR equipment, as well as to discuss how to quantify the reliability of GPR results. An

  16. Real-Gas Effects on the Aerodynamics of Blunt Cones as Measured in a Hypervelocity Range

    DTIC Science & Technology

    1979-10-01

    and 0.3. The cones tested had nominal base diameters of either 1.0 or 1.5 in. and were fabricated of aluminum except for the nosetlps. All cones...high aerodynamic heating conditions. Sabots used were of a conventional four-component design and were fabricated o f Lexan ® . All cones were...whereas the test cones were fabricated with a nominal edge radius of 0.03 in. "Provided b.’, E. O. Marchand, formerly of ARO, Inc. 15 A E D C - T R

  17. Experimental investigation of penetration performance of shaped charge into concrete targets

    NASA Astrophysics Data System (ADS)

    Wang, Cheng; Ma, Tianbao; Ning, Jianguo

    2008-06-01

    In order to develop a tandem warhead that can effectively destroy concrete targets, this paper explores the penetration performance of shaped charges with different cone angles and liner materials into concrete targets by means of experiments. The penetration process and the destruction mechanism of concrete targets by shaped charges and kinetic energy projectiles are analyzed and compared. Experimental results suggest that both kinetic energetic projectile and shaped charge are capable of destroying concrete targets, but the magnitudes of damage are different. Compared with a kinetic energy projectile, a shaped charge has more significant effect of penetration into the target, and causes very large spalling area. Hence, a shaped charge is quite suitable for first-stage charge of tandem warhead. It is also found that, with the increase of shaped charge liner cone angle, the depth of penetration decreases gradually while the hole diameter becomes larger. Penetration depth with copper liner is larger than of aluminum liner but hole diameter is relatively smaller, and the shaped charge with steel liner is between the above two cases. The shaped charge with a cone angle of 100° can form a jet projectile charge (JPC). With JPC, a hole with optimum depth and diameter on concrete targets can be formed, which guarantees that the second-stage warhead smoothly penetrates into the hole and explodes at the optimum depth to achieve the desired level of destruction in concrete targets.

  18. A review of an attempt to create shatter cones with magnetic flyer plate technology

    NASA Technical Reports Server (NTRS)

    Linnerud, H. J.

    1981-01-01

    The feasibility of creating shatter cones in a controlled laboratory environment is discussed. Magnetic flyer plate technology, which generates high amplitude shock waves in test materials is discribed. Considerable sample shear and break up was observed, however, no shatter cones are found in the tested samples.

  19. Penetration Physics of Armor Glass

    DTIC Science & Technology

    2009-11-30

    around impact site .....................................5 Figure 3. Off-center section showing in-situ fragments formed by intersecting cone and lateral...Closely-spaced cone cracks beneath the nose of an arrested projectile ....................8 Figure 6. Agglomerated glass fragments attached to a projectile...fragments. All targets showed cone cracks, radial cracks, ring cracks, and lateral cracks typical of particle or rod impact. A cylindrically “tunnel” of

  20. Embryonic markers of cone differentiation

    PubMed Central

    Rodgers, Helen M.; Belcastro, Marycharmain; Sokolov, Maxim

    2016-01-01

    Purpose Photoreceptor cells are born in two distinct phases of vertebrate retinogenesis. In the mouse retina, cones are born primarily during embryogenesis, while rod formation occurs later in embryogenesis and early postnatal ages. Despite this dichotomy in photoreceptor birthdates, the visual pigments and phototransduction machinery are not reactive to visual stimulus in either type of photoreceptor cell until the second postnatal week. Several markers of early cone formation have been identified, including Otx2, Crx, Blimp1, NeuroD, Trβ2, Rorβ, and Rxrγ, and all are thought to be involved in cellular determination. However, little is known about the expression of proteins involved in cone visual transduction during early retinogenesis. Therefore, we sought to characterize visual transduction proteins that are expressed specifically in photoreceptors during mouse embryogenesis. Methods Eye tissue was collected from control and phosducin-null mice at embryonic and early postnatal ages. Immunohistochemistry and quantitative reverse transcriptase-PCR (qPCR) were used to measure the spatial and temporal expression patterns of phosducin (Pdc) and cone transducin γ (Gngt2) proteins and transcripts in the embryonic and early postnatal mouse retina. Results We identified the embryonic expression of phosducin (Pdc) and cone transducin γ (Gngt2) that coincides temporally and spatially with the earliest stages of cone histogenesis. Using immunohistochemistry, the phosducin protein was first detected in the retina at embryonic day (E)12.5, and cone transducin γ was observed at E13.5. The phosducin and cone transducin γ proteins were seen only in the outer neuroblastic layer, consistent with their expression in photoreceptors. At the embryonic ages, phosducin was coexpressed with Rxrγ, a known cone marker, and with Otx2, a marker of photoreceptors. Pdc and Gngt2 mRNAs were detected as early as E10.5 with qPCR, although at low levels. Conclusions Visual transduction

  1. Visual Pigments of Goldfish Cones

    PubMed Central

    Hárosi, Ferenc I.; MacNichol, Edward F.

    1974-01-01

    Freshly isolated retinal photoreceptors of goldfish were studied microspectrophotometrically. Absolute absorptance spectra obtained from dark-adapted cone outer segments reaffirm the existence of three spectrally distinct cone types with absorption maxima at 455 ± 3,530 ± 3, and 625 ± 5 nm. These types were found often recognizable by gross cellular morphology. Side-illuminated cone outer segments were dichroic. The measured dichroic ratio for the main absorption band of each type was 2–3:1. Rapidly bleached cells revealed spectral and dichroic transitions in regions near 400–410, 435–455, and 350–360 nm. These photoproducts decay about fivefold as fast as the intermediates in frog rods. The spectral maxima of photoproducts, combined with other evidence, indicate that retinene2 is the chromophore of all three cone pigments. The average specific optical density for goldfish cone outer segments was found to be 0.0124 ± 0.0015/µm. The spectra of the blue-, and green-absorbing cones appeared to match porphyropsin standards with half-band width Δν = 4,832 ± 100 cm–1. The red-absorbing spectrum was found narrower, having Δν = 3,625 ± 100 cm–1. The results are consistent with the notion that visual pigment concentration within the outer segments is about the same for frog rods and goldfish cones, but that the blue-, and green-absorbing pigments possess molar extinctions of 30,000 liter/mol cm. The red-absorbing pigment was found to have extinction of 40,000 liter/mol cm, assuming invariance of oscillator strength among the three cone spectra. PMID:4817352

  2. Tests of ground-penetrating radar and induced polarization for mapping fluvial mine tailings on the floor of the Couer d'Alene River, Idaho

    USGS Publications Warehouse

    Campbell, David L.; Wynn, Jefferey C.; Box, Stephen E.; Bookstrom, Arthur A.; Horton, Robert J.

    1997-01-01

    In order to investigate sequences of toxic mine tailings that have settled in the bed of the Coeur d'Alene River, Idaho, (see figure 1) we improvised ways to make geophysical measurements on the river floor. To make ground penetrating radar (GPR) profiles, we mounted borehole antennas on a skid that was towed along the river bottom. To make induced polarization (IP) profiles, we devised a bottom streamer from a garden hose, lead strips, PVC standoffs, and insulated wire. Each approach worked and provided uniquely different information about the buried toxic sediments. GPR showed shallow stratigraphy, but did not directly detect the presence of contaminating metals. IP showed a zone of high chargeability that is probably due to pockets of relatively higher metal content. Neither method was able to define the base of the fluvial tailings section, at least in part because the IP streamer was deliberately designed to sample only the top three meters of sediments to maximize horizontal resolution.

  3. Large-Cone Nonnegative Matrix Factorization.

    PubMed

    Liu, Tongliang; Gong, Mingming; Tao, Dacheng

    2016-06-15

    Nonnegative matrix factorization (NMF) has been greatly popularized by its parts-based interpretation and the effective multiplicative updating rule for searching local solutions. In this paper, we study the problem of how to obtain an attractive local solution for NMF, which not only fits the given training data well but also generalizes well on the unseen test data. Based on the geometric interpretation of NMF, we introduce two large-cone penalties for NMF and propose large-cone NMF (LCNMF) algorithms. Compared with NMF, LCNMF will obtain bases comprising a larger simplicial cone, and therefore has three advantages. 1) the empirical reconstruction error of LCNMF could mostly be smaller; (2) the generalization ability of the proposed algorithm is much more powerful; and (3) the obtained bases of LCNMF have a low-overlapping property, which enables the bases to be sparse and makes the proposed algorithms very robust. Experiments on synthetic and real-world data sets confirm the efficiency of LCNMF.

  4. Transition from fractal cracking to fragmentation due to projectile penetration

    NASA Astrophysics Data System (ADS)

    Kun, F.; Halász, Z.

    2014-12-01

    We present a theoretical study of the fracture of two-dimensional disc-shaped samples due to the penetration of a projectile focusing on the dynamics of fracturing and on the geometrical structure of the generated crack pattern. The penetration of a cone is simulated into a plate of circular shape using a discrete element model of heterogeneous brittle materials varying the speed of penetration in a broad range. As the cone penetrates a destroyed zone is created from which cracks run to the external boundary of the plate. Computer simulations revealed that in the low speed limit of loading two cracks are generated with nearly straight shape. Increasing the penetration speed the crack pattern remains regular, however, both the number of cracks and their fractal dimension increases. High speed penetration gives rise to a crack network such that the sample gets fragmented into a large number of pieces. We give a quantitative analysis of the evolution of the system from simple cracking through fractal cracks to fragmentation with a connected crack network. Simulations showed that in the low speed limit of loading the growing cracks proceed in discrete jumps separated by periods when the crack tips are pinned. The statistics of the size of jumps and of the waitng times shows scale free behaviour, i.e. power law distributions are obtained with universal exponents. Dependence on the loading speed was pointed out only for the cutoffs of the distributions. In the high speed limit of loading the sample falls apart forming a large number of fragments. The size of fragments proved to be power law distributed where dependence on the loading speed is observed only for the cutoffs. The value of the exponent has good agreement with experiments.

  5. Cone size is related to branching architecture in conifers.

    PubMed

    Leslie, Andrew B; Beaulieu, Jeremy M; Crane, Peter R; Donoghue, Michael J

    2014-09-01

    The relationship between branch diameter and leaf size has been widely used to understand how vegetative resources are allocated in plants. Branching architecture influences reproductive allocation as well, but fewer studies have explored this relationship at broad phylogenetic or ecological scales. In this study, we tested whether pollen-producing and seed-producing cone size scales with branch diameter in conifers, a diverse and globally distributed lineage of nonflowering seed plants. Branch diameter and cone size were analyzed using multiple regression models and evolutionary models of trait evolution for a data set of 293 extant conifer species within an explicit phylogenetic framework. Branch diameter is a strong predictor of cone size across conifer species, particularly for pollen cones and dry seed cones. However, these relationships are complex in detail because leaf morphology and seed dispersal biology influence the specific ways in which they are expressed. The ubiquity and strength of these scaling relationships across conifers suggest that reproductive and vegetative morphologies are coupled in the group, and it is therefore difficult to disentangle the evolution of cone size from the evolution of branching architecture.

  6. Numerical Modeling of Shatter Cones Development in Impact Craters

    NASA Technical Reports Server (NTRS)

    Baratoux, D.; Melosh, H. J.

    2003-01-01

    Shatter cones are the characteristic forms of rock fractures in impact structures. They have been used for decades as unequivocal fingerprints of meteoritic impacts on Earth. The abundant data about shapes, apical angles, sizes and distributions of shatter cones for many terrestrial impact structures should provide insights for the determination of impact conditions and characteristics of shock waves produced by high-velocity projectiles in geologic media. However, previously proposed models for the formation of shatter cones do not agree with observations. For example, the widely accepted Johnson-Talbot mechanism requires that the longitudinal stress drops to zero between the arrival of the elastic precursor and the main plastic wave. Unfortunately, observations do not support such a drop. A model has been also proposed to explain the striated features on the surface of shatter cones but can not invoked for their conical shape. The mechanism by which shatter cones form thus remains enigmatic to date. In this paper we present a new model for the formation of shatter cones. Our model has been tested by means of numerical simulations using the hydrocodes SALE 2D enhanced with the Grady-Kipp-Melosh fragmentation model.

  7. Hadronic wavefunctions in light-cone quantization

    SciTech Connect

    Hyer, T.

    1994-05-01

    The analysis of light-cone wavefunctions seems the most promising theoretical approach to a detailed understanding of the structure of relativistic bound states, particularly hadrons. However, there are numerous complications in this approach. Most importantly, the light-cone approach sacrifices manifest rotational invariance in exchange for the elimination of negative-energy states. The requirement of rotational invariance of the full theory places important constraints on proposed light-cone wavefunctions, whether they are modelled or extracted from some numerical procedure. A formulation of the consequences of the hidden rotational symmetry has been sought for some time; it is presented in Chapter 2. In lattice gauge theory or heavy-quark effective theory, much of the focus is on the extraction of numerical values of operators which are related to the hadronic wavefunction. These operators are to some extent interdependent, with relations induced by fundamental constraints on the underlying wavefunction. The consequences of the requirement of unitarity are explored in Chapter 3, and are found to have startling phenomenological relevance. To test model light-cone wavefunctions, experimental predictions must be made. The reliability of perturbative QCD as a tool for making such predictions has been questioned. In Chapter 4, the author presents a computation of the rates for nucleon-antinucleon annihilation, improving the reliability of the perturbative computation by taking into account the Sudakov suppression of exclusive processes at large transverse impact parameter. In Chapter 5, he develops the analysis of semiexclusive production. This work focuses on processes in which a single isolated meson is produced perturbatively and recoils against a wide hadronizing system. At energies above about 10 GeV, semiexclusive processes are shown to be the most sensitive experimental probes of hadronic structure.

  8. Preliminary Drag and Heat-transfer Data Obtained from Air-launched Cone-cylinder Test Vehicle over Mach Number Range from 1.5 to 5.18

    NASA Technical Reports Server (NTRS)

    Messing, Wesley E; Rabb, Leonard; Disher, John H

    1953-01-01

    An air-launched cone-cylinder test vehicle designed to obtain data at Mach numbers above 4.0 was rocket boosted from a release Mach number of 5.18. The vehicle was launched at an altitude of 35,000 feet and reached peak velocity of 5150 feet per second at 28,500 feet. The total-drag coefficient (based on maximum cross-sectional area) decreased gradually from 0.31 at a Mach number of 1.75 to 0.145 at a Mach number of 5.18, while the Reynold's number (based on body length) increased from 31 x 10 to the 6th power to 107 x 10 to the 6th power. The skin friction coefficients, in general, were slightly lower than Van Driest's theoretical values for similar wall-temperature conditions. Convective heat-transfer coefficients were obtained from a single skin-thermocouple measurement. The maximum wall temperature recorded was 1240 degrees r.

  9. Soil penetrometers and penetrability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil penetrometers are useful tools that measure the penetrability, or strength, of a soil. They can be as simple as a rod or shaft with a blunt or sharp end, or complicated mechanically driven instruments with digital data collection systems. Regardless of their design, soil penetrometers measure s...

  10. Penetration resistant barrier

    DOEpatents

    Hoover, William R.; Mead, Keith E.; Street, Henry K.

    1977-01-01

    The disclosure relates to a barrier for resisting penetration by such as hand tools and oxy-acetylene cutting torches. The barrier comprises a layer of firebrick, which is preferably epoxy impregnated sandwiched between inner and outer layers of steel. Between the firebrick and steel are layers of resilient rubber-like filler.

  11. Characterization of nuclear reactor containment penetrations. Preliminary report

    SciTech Connect

    Bump, T.R.; Seidensticker, R.W.; Shackelford, M.A.; Gambhir, V.K.; McLennan, G.L.

    1984-06-01

    This report summarizes the survey work conducted by Argonne National Laboratory on the design and details of major penetrations in 22 nuclear power plants. The survey includes all containment types and materials in current use. It also includes details of all types of penetrations (except for electrical penetration assemblies and valves) and the seals and gaskets used in them. The report provides a test matrix for testing major penetrations and for testing seals and gaskets in order to evaluate their leakage potential under severe accident conditions.

  12. Using the inertia of spacecraft during landing to penetrate regoliths of the Solar System

    NASA Astrophysics Data System (ADS)

    Paton, M. D.; Green, S. F.; Ball, A. J.; Zarnecki, J. C.; Harri, A.-M.

    2015-09-01

    The high inertia, i.e. high mass and low speed, of a landing spacecraft has the potential to drive a penetrometer into the subsurface without the need for a dedicated deployment mechanism, e.g., during Huygens landing on Titan. Such a method could complement focused subsurface exploration missions, particularly in the low gravity environments of comets and asteroids, as it is conducive to conducting surveys and to the deployment of sensor networks. We make full-scale laboratory simulations of a landing spacecraft with a penetrometer attached to its base plate. The tip design is based on that used in terrestrial Cone Penetration Testing (CPT) with a large enough shaft diameter to house instruments for analysing pristine subsurface material. Penetrometer measurements are made in a variety of regolith analogue materials and target compaction states. For comparison a copy of the ACC-E penetrometer from the Huygens mission to Titan is used. A test rig at the Open University is used and is operated over a range of speeds from 0.9 to 3 m s-1 and under two gravitational accelerations. The penetrometer was found to be sensitive to the target's compaction state with a high degree of repeatability. The penetrometer measurements also produced unique pressure profile shapes for each material. Measurements in limestone powder produced an exponential increase in pressure with depth possibly due to increasing compaction with depth. Measurements in sand produced an almost linear increase in pressure with depth. Iron powder produced significantly higher pressures than sand presumably due to the rough surface of the grains increasing the grain-grain friction. Impacts into foamglas produced with both ACC-E and the large penetrometer produced an initial increase in pressure followed by a leveling off as expected in a consolidated material. Measurements in sand suggest that the pressure on the tip is not significantly dependent on speed over the range tested, which suggests bearing

  13. Ground-penetrating radar images of a dye tracer test within the unsaturated zone at the Susquehanna-Shale Hills CZO

    NASA Astrophysics Data System (ADS)

    Pitman, Lacey M.

    Dye tracer and time-lapse ground-penetrating radar (GPR) were used to image preferential flow paths in the shallow, unsaturated zone on hillslopes in two adjacent watersheds within the Susquehanna-Shale Hills Critical Zone Observatory (CZO). At each site we injected about 50 L of water mixed with brilliant blue dye (4 g/L) into a trench cut perpendicular to the slope (˜1.0 m long by ˜0.20 m wide by ˜0.20 m deep) to create a line of infiltration. GPR (800 MHz antennae with constant offset) was used to monitor the movement of the dye tracer downslope on a 1.0 m x 2.0 m grid with a 0.05 m line spacing. The site was then excavated and the stained pathways photographed to document the dye movement. We saw a considerable difference in the pattern of shallow preferential flow between the two sites despite similar soil characteristics and slope position. Both sites showed dye penetrating down to saprolite (˜0.40 m); however, lateral flow migration between the two sites was different. At the Missed Grouse field site, the lateral migration was ˜0.55 m as an evenly dispersed plume, but at distance of 0.70 m a finger of dye was observed. At the Shale Hills field site, the total lateral flow was ˜0.40 m, dye was barely visible until the excavation reached ˜0.10 m, and there was more evidence of distinct fingering in the vertical direction. Based on laboratory and field experiments as well as processing of the radargrams, the following conclusions were drawn: 1) time-lapse GPR successfully delineated the extent of lateral flow, but the GPR resolution was insufficient to detect small fingers of dye; 2) there was not a distinct GPR reflection at the regolith-saprock boundary, but this interface could be estimated from the extent of signal attenuation; 3) the preliminary soil moisture conditions may explain differences in the extent of infiltration at the two sites; 4) rapid infiltration into the underlying saprock limited the extent of shallow lateral flow at both sites and

  14. Subsurface investigation with ground penetrating radar

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ground penetrating radar (GPR) data was collected on a small test plot at the OTF/OSU Turfgrass Research & Education Facility in Columbus, Ohio. This test plot was built to USGA standards for a golf course green, with a constructed sand layer just beneath the surface overlying a gravel layer, that i...

  15. Hydrovolcanic (Tuff?) Rings and Cones on Mars: Evidence for Phreatomagmatic Explosive Eruptions?

    NASA Astrophysics Data System (ADS)

    Broz, P.; Hauber, E.

    2012-09-01

    We present observations of two fields of small pitted and mostly breached cones; one located along the dichotomy boundary in the Amenthes region (southern Utopia); the second located in an unnamed impact crater in the Xanthe Terra region. The aim of our study is to test the hypothesis of a (hydro)volcanic origin of these cones, which would be an alternative to the mud volcano scenario put forward by [1] for cones in Amenthes region. To aid our analysis, we also examine morphological and morphometrical data of possible terrestrial analogues (tuff rings and cones, mud volcanoes in Azerbaijan).

  16. Initial testing of advanced ground-penetrating radar technology for the inspection of bridge decks: the HERMES and PERES Bridge Inspectors

    NASA Astrophysics Data System (ADS)

    Davidson, Nigel C.; Chase, Steven B.

    1999-02-01

    Since early 1995 the Federal Highway Administration (FHWA) has been sponsoring the development of ground-penetrating radar technology to produce a tool for the non-destructive evaluation of bridge decks. Under contract with the FHWA, Lawrence Livermore National Laboratory designed and built a system capable of recording data over a 2 meter width during normal traffic flow. The derived system is called `The HERMES Bridge Inspector' (High-speed Electromagnetic Roadway Measurement and Evaluation System) and includes a 64 channel antenna array within a 30 ft trailer. For detailed investigation of portions of a bridge deck, a robotic cart mounted radar has been developed. This cart system is named `The PERES Bridge Inspector' (Precision Electromagnetic Roadway Evaluation System). PERES records data over the chosen area by rastering a single transceiver over the road. Images of the deck interior are reconstructed from the original synthetic aperture data using diffraction tomography. The work presented herein describes the findings of initial experiments conducted to determine the inspection capabilities of these systems. Internal defects such as delaminations, voids and disbonds; and construction details including deck thickness, asphalt overlay thickness and reinforcement layout were the features targeted. The final goal is for these systems, and other non-destructive technologies, to provide information on the condition of the nation's bridges for input to bridge management systems.

  17. A spectral isoperimetric inequality for cones

    NASA Astrophysics Data System (ADS)

    Exner, Pavel; Lotoreichik, Vladimir

    2017-04-01

    In this note, we investigate three-dimensional Schrödinger operators with δ -interactions supported on C^2-smooth cones, both finite and infinite. Our main results concern a Faber-Krahn-type inequality for the principal eigenvalue of these operators. The proofs rely on the Birman-Schwinger principle and on the fact that circles are unique minimizers for a class of energy functionals. The main novel idea consists in the way of constructing test functions for the Birman-Schwinger principle.

  18. Cognitive Penetration and Attention

    PubMed Central

    Gross, Steven

    2017-01-01

    Zenon Pylyshyn argues that cognitively driven attentional effects do not amount to cognitive penetration of early vision because such effects occur either before or after early vision. Critics object that in fact such effects occur at all levels of perceptual processing. We argue that Pylyshyn’s claim is correct—but not for the reason he emphasizes. Even if his critics are correct that attentional effects are not external to early vision, these effects do not satisfy Pylyshyn’s requirements that the effects be direct and exhibit semantic coherence. In addition, we distinguish our defense from those found in recent work by Raftopoulos and by Firestone and Scholl, argue that attention should not be assimilated to expectation, and discuss alternative characterizations of cognitive penetrability, advocating a kind of pluralism. PMID:28275358

  19. Antibody tumor penetration

    PubMed Central

    Thurber, Greg M.; Schmidt, Michael M.; Wittrup, K. Dane

    2009-01-01

    Antibodies have proven to be effective agents in cancer imaging and therapy. One of the major challenges still facing the field is the heterogeneous distribution of these agents in tumors when administered systemically. Large regions of untargeted cells can therefore escape therapy and potentially select for more resistant cells. We present here a summary of theoretical and experimental approaches to analyze and improve antibody penetration in tumor tissue. PMID:18541331

  20. Shatter cones: (Mis)understood?

    PubMed Central

    Osinski, Gordon R.; Ferrière, Ludovic

    2016-01-01

    Meteorite impact craters are one of the most common geological features in the solar system. An impact event is a near-instantaneous process that releases a huge amount of energy over a very small region on a planetary surface. This results in characteristic changes in the target rocks, from vaporization and melting to solid-state effects, such as fracturing and shock metamorphism. Shatter cones are distinctive striated conical fractures that are considered unequivocal evidence of impact events. They are one of the most used and trusted shock-metamorphic effects for the recognition of meteorite impact structures. Despite this, there is still considerable debate regarding their formation. We show that shatter cones are present in several stratigraphic settings within and around impact structures. Together with the occurrence of complete and “double” cones, our observations are most consistent with shatter cone formation due to tensional stresses generated by scattering of the shock wave due to heterogeneities in the rock. On the basis of field mapping, we derive the relationship Dsc = 0.4 Da, where Dsc is the maximum spatial extent of in situ shatter cones, and Da is the apparent crater diameter. This provides an important, new, more accurate method to estimate the apparent diameter of eroded complex craters on Earth. We have reestimated the diameter of eight well-known impact craters as part of this study. Finally, we suggest that shatter cones may reduce the strength of the target, thus aiding crater collapse, and that their distribution in central uplifts also records the obliquity of impact. PMID:27532050

  1. Shatter cones: (Mis)understood?

    PubMed

    Osinski, Gordon R; Ferrière, Ludovic

    2016-08-01

    Meteorite impact craters are one of the most common geological features in the solar system. An impact event is a near-instantaneous process that releases a huge amount of energy over a very small region on a planetary surface. This results in characteristic changes in the target rocks, from vaporization and melting to solid-state effects, such as fracturing and shock metamorphism. Shatter cones are distinctive striated conical fractures that are considered unequivocal evidence of impact events. They are one of the most used and trusted shock-metamorphic effects for the recognition of meteorite impact structures. Despite this, there is still considerable debate regarding their formation. We show that shatter cones are present in several stratigraphic settings within and around impact structures. Together with the occurrence of complete and "double" cones, our observations are most consistent with shatter cone formation due to tensional stresses generated by scattering of the shock wave due to heterogeneities in the rock. On the basis of field mapping, we derive the relationship D sc = 0.4 D a, where D sc is the maximum spatial extent of in situ shatter cones, and D a is the apparent crater diameter. This provides an important, new, more accurate method to estimate the apparent diameter of eroded complex craters on Earth. We have reestimated the diameter of eight well-known impact craters as part of this study. Finally, we suggest that shatter cones may reduce the strength of the target, thus aiding crater collapse, and that their distribution in central uplifts also records the obliquity of impact.

  2. [Penetrating abdominal injuries].

    PubMed

    Nesbakken, A; Pillgram-Larsen, J; Naess, F; Gerner, T; Solheim, K; Stadaas, J O; Gjøra, O

    1990-02-28

    We have reviewed the medical records of 111 patients treated for abdominal stab wounds during the period 1980-87. Our two hospitals serve a catchment area of about 450,000 people. Exploratory laparotomy was performed in 89 patients with suspected peritoneal penetration. In 16 patients the laparotomy was negative, and in 15 patients only minor injuries were noted. There were no serious complications in these 31 patients. Twenty-seven patients had thoracic wounds below the fourth intercostal space, 15 with intraabdominal injuries. The most common injuries were lacerations of the liver, the small bowel and the diaphragm. The mortality in the series was 2%. Stab wounds are infrequent in Norway, and most surgeons have limited experience of such injuries. We discuss whether to employ immediate exploratory laparotomy or selective management when the peritoneum has been penetrated. When there is no evidence of evisceration or omental protrusion, local exploration of the wound should be performed in order to confirm or exclude peritoneal penetration. Injury to the diaphragm and intraabdominal viscera should always be suspected in thoracic stab wounds below the fourth intercostal space.

  3. Mars penetrator: Subsurface science mission

    NASA Technical Reports Server (NTRS)

    Lumpkin, C. K.

    1974-01-01

    A penetrator system to emplace subsurface science on the planet Mars is described. The need for subsurface science is discussed, and the technologies for achieving successful atmospheric entry, Mars penetration, and data retrieval are presented.

  4. Real Gas/Blunt Cone. Phase 2

    NASA Technical Reports Server (NTRS)

    Deiwert, George S.; Eitelberg, Georg

    1998-01-01

    In this chapter recent activity in real-gas database definition and code validation will be summarized. In the Phase I report of the Working Group (WG) 181, aerothermodynamic problems were classified, for purpose of discussion, into seven types: aerodynamic parameters, viscous/shock interaction, boundary-layer transition, forebody-heating/heat-transfer, radiation and ablation, lee and base-region flow, and low-density flow. Several of these problem types were the subject of various chapters of the Phase 1 report describing real-gas effects and ground test facility issues. In this chapter some background and objectives outlined in the real-Gas effects Chapter V of the Phase 1 report will be reviewed. The results of the blunt cone test campaign developed under the auspices of the WG18 activity to study real-gas phenomena will be summarized, including the experimental and computational programs, issues and questions, and recommendations. Further, recent progress in other real-gas areas beyond the blunt cone test campaign will be discussed. Finally, a summary in which the present status of our understanding of real-gas issues will be presented.

  5. Regulation of neuronal growth cone filopodia by nitric oxide.

    PubMed

    Van Wagenen, S; Rehder, V

    1999-05-01

    Nitric oxide (NO) has been proposed to play an important role during neuronal development. Since many of its effects occur during the time of growth cone pathfinding and target interaction, we here test the hypothesis that part of NO's effects might be exerted at the growth cone. We found that low concentrations of the NO-donors DEA/NO, SIN-1, and SNP caused a rapid and transient elongation of filopodia as well as a reduction in filopodial number. These effects resulted from distinct changes in filopodial extension and retraction rates. Our novel findings suggest that NO could play a physiological role by temporarily changing a growth cone's morphology and switching its behavior from a close-range to a long-range exploratory mode. We subsequently dissected the pathway by which NO acted on growth cones. The effect of NO donors on filopodial length could be blocked by 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one, an inhibitor of soluble guanylyl cyclase (sGC), indicating that NO acted via sGC. Supporting this idea, injection of cyclic GMP (cGMP) mimicked the effect of NO donors on growth cone filopodia. Moreover, application of NO-donors as well as injection of cGMP elicited a rapid and transient rise in intracellular calcium in growth cones, indicating that NO acted via cGMP to elevate calcium. This calcium rise, as well as the morphological effects of SIN-1 on filopodia, were blocked by preventing calcium entry. Given the role of filopodia in axonal guidance, our new data suggest that NO could function at the neuronal growth cone as an intracellular and/or intercellular signaling molecule by affecting steering decisions during neuronal pathfinding.

  6. PHIL Inverter Test Report: Analysis of High-Penetration Levels of PV into the Distribution Grid in California, March 12 - March 16, 2012

    SciTech Connect

    Kromer, M.

    2013-06-01

    This report describes power hardware-in-the-loop simulation testing of a 500 kW Satcon photovoltaic inverter, conducted at the Center for Advanced Power Systems at Florida State University from March 12th through March 16th, 2012. Testing was led by a team from the National Renewable Energy Laboratory. The report reviews the results of data captured during the course of testing. The tests were used to demonstrate operation of and gather data from the inverter in a simulated operational environment. Testing demonstrated the ability of the inverter to operate in either a Power Factor Control Mode or a Reactive Power Command Mode, and to respond to real power limits.

  7. IMPLOSION OF INDIRECTLY DRIVEN REENTRANT CONE SHELL TARGET

    SciTech Connect

    STEPHENS,RB

    2003-08-01

    OAK-B135 The authors have examined the implosion of an indirectly driven reentrant-cone shell target to clarify the issues attendant on compressing fuel for a fast ignition target. The target design is roughly hydrodynamic equivalent to a NIF cryo-ignition target, but scaled down to be driven by Omega. A sequence of backlit x-radiographs recorded each implosion. The collapse was also modeled with LASNEX, generating simulated radiographs. They compare experimental and simulated diameter, density and symmetry as functions of time near stagnation. The simulations were generally in good agreement with the experiments with respect to the shell, but did not show the opacity due to ablation of gold off the cone; non-thermal gold M-line radiation from the hohlraum wall penetrates the shell and drives this ablation causing some Au to mix into the low density center of the core and into the region between the core and cone. This might be a problem in a cryo-ignition target.

  8. The effect of a planetary surface penetrator on the soil column surrounding the impacting body

    NASA Technical Reports Server (NTRS)

    Blanchard, M. B.; Shade, H. D.

    1975-01-01

    A prototype penetrator instrument was impacted into a dry lake bed. Laboratory studies of the soil surrounding the penetrator revealed that the soil was contaminated by paint and metal from the penetrator's casing. Paint pigment rich in titanium and sulfur was found in the adjacent soil. The highly mobile paint pigment migrated onto viewing ports in the penetrator's exterior. Bulk analysis of the soil adjacent to the impactor showed a significant increase in both elements, as well as the presence of metal chips from the casing and nose cone. It is recommended that great care be taken in the use of coating materials and the metal alloys selected for the penetrator's exterior, or the accuracy of any experiment requiring an uncontaminated in situ sample may be adversely affected.

  9. Hydrovolcanic tuff rings and cones as indicators for phreatomagmatic explosive eruptions on Mars

    NASA Astrophysics Data System (ADS)

    Brož, P.; Hauber, E.

    2013-08-01

    is a common natural phenomenon on Earth and should be common on Mars, too, since its surface shows widespread evidence for volcanism and near-surface water. We investigate fields of pitted cones in the Nephentes/Amenthes region at the southern margin of the ancient impact basin, Utopia, which were previously interpreted as mud volcanoes. The cone fields contain pitted and breached cones with associated outgoing flow-like landforms. Based on stratigraphic relations, we determined a Hesperian or younger model age. We test the hypothesis of a (hydro)volcanic origin. Based on a detailed morphological and morphometrical analysis and an analysis of the regional context, an igneous volcanic origin of these cones as hydrovolcanic edifices produced by phreatomagmatic eruptions is plausible. Several lines of evidence suggest the existence of subsurface water ice. The pitted cones display well-developed wide central craters with floor elevations below the preeruptive surface. Their morphometry and the overall appearance are analogous to terrestrial tuff cones and tuff rings. Mounds that are also observed in the same region resemble terrestrial lava domes. The hydrovolcanic interaction between ascending magma and subsurface water and/or water ice may explain the formation of the pitted cones, although other scenarios such as mud volcanism cannot be ruled out. Together with the mounds, the cones might represent effusive and explosive edifices of a monogenetic volcanic field composed of lava domes, tuff rings, tuff cones, and possibly maars.

  10. Pit Latrine Fecal Sludge Resistance Using a Dynamic Cone Penetrometer in Low Income Areas in Mzuzu City, Malawi.

    PubMed

    Chirwa, Charles F C; Hall, Ralph P; Krometis, Leigh-Anne H; Vance, Eric A; Edwards, Adam; Guan, Ting; Holm, Rochelle H

    2017-02-03

    Pit latrines can provide improved household sanitation, but without effective and inexpensive emptying options, they are often abandoned once full and may pose a public health threat. Emptying techniques can be difficult, as the sludge contents of each pit latrine are different. The design of effective emptying techniques (e.g., pumps) is limited by a lack of data characterizing typical in situ latrine sludge resistance. This investigation aimed to better understand the community education and technical engineering needs necessary to improve pit latrine management. In low income areas within Mzuzu city, Malawi, 300 pit latrines from three distinct areas were assessed using a dynamic cone penetrometer to quantify fecal sludge strength, and household members were surveyed to determine their knowledge of desludging procedures and practices likely to impact fecal sludge characteristics. The results demonstrate that there is a significant difference in sludge strength between lined and unlined pits within a defined area, though sludge hardened with depth, regardless of the pit type or region. There was only limited association between cone penetration depth and household survey data. To promote the adoption of pit emptying, it is recommended that households be provided with information that supports pit emptying, such as latrine construction designs, local pit emptying options, and cost. This study indicates that the use of a penetrometer test in the field prior to pit latrine emptying may facilitate the selection of appropriate pit emptying technology.

  11. Pit Latrine Fecal Sludge Resistance Using a Dynamic Cone Penetrometer in Low Income Areas in Mzuzu City, Malawi

    PubMed Central

    Chirwa, Charles F. C.; Hall, Ralph P.; Krometis, Leigh-Anne H.; Vance, Eric A.; Edwards, Adam; Guan, Ting; Holm, Rochelle H.

    2017-01-01

    Pit latrines can provide improved household sanitation, but without effective and inexpensive emptying options, they are often abandoned once full and may pose a public health threat. Emptying techniques can be difficult, as the sludge contents of each pit latrine are different. The design of effective emptying techniques (e.g., pumps) is limited by a lack of data characterizing typical in situ latrine sludge resistance. This investigation aimed to better understand the community education and technical engineering needs necessary to improve pit latrine management. In low income areas within Mzuzu city, Malawi, 300 pit latrines from three distinct areas were assessed using a dynamic cone penetrometer to quantify fecal sludge strength, and household members were surveyed to determine their knowledge of desludging procedures and practices likely to impact fecal sludge characteristics. The results demonstrate that there is a significant difference in sludge strength between lined and unlined pits within a defined area, though sludge hardened with depth, regardless of the pit type or region. There was only limited association between cone penetration depth and household survey data. To promote the adoption of pit emptying, it is recommended that households be provided with information that supports pit emptying, such as latrine construction designs, local pit emptying options, and cost. This study indicates that the use of a penetrometer test in the field prior to pit latrine emptying may facilitate the selection of appropriate pit emptying technology. PMID:28165378

  12. Cone Photoreceptor Structure in Patients With X-Linked Cone Dysfunction and Red-Green Color Vision Deficiency

    PubMed Central

    Patterson, Emily J.; Wilk, Melissa; Langlo, Christopher S.; Kasilian, Melissa; Ring, Michael; Hufnagel, Robert B.; Dubis, Adam M.; Tee, James J.; Kalitzeos, Angelos; Gardner, Jessica C.; Ahmed, Zubair M.; Sisk, Robert A.; Larsen, Michael; Sjoberg, Stacy; Connor, Thomas B.; Dubra, Alfredo; Neitz, Jay; Hardcastle, Alison J.; Neitz, Maureen; Michaelides, Michel; Carroll, Joseph

    2016-01-01

    Purpose Mutations in the coding sequence of the L and M opsin genes are often associated with X-linked cone dysfunction (such as Bornholm Eye Disease, BED), though the exact color vision phenotype associated with these disorders is variable. We examined individuals with L/M opsin gene mutations to clarify the link between color vision deficiency and cone dysfunction. Methods We recruited 17 males for imaging. The thickness and integrity of the photoreceptor layers were evaluated using spectral-domain optical coherence tomography. Cone density was measured using high-resolution images of the cone mosaic obtained with adaptive optics scanning light ophthalmoscopy. The L/M opsin gene array was characterized in 16 subjects, including at least one subject from each family. Results There were six subjects with the LVAVA haplotype encoded by exon 3, seven with LIAVA, two with the Cys203Arg mutation encoded by exon 4, and two with a novel insertion in exon 2. Foveal cone structure and retinal thickness was disrupted to a variable degree, even among related individuals with the same L/M array. Conclusions Our findings provide a direct link between disruption of the cone mosaic and L/M opsin variants. We hypothesize that, in addition to large phenotypic differences between different L/M opsin variants, the ratio of expression of first versus downstream genes in the L/M array contributes to phenotypic diversity. While the L/M opsin mutations underlie the cone dysfunction in all of the subjects tested, the color vision defect can be caused either by the same mutation or a gene rearrangement at the same locus. PMID:27447086

  13. Cone positioning device for oral radiation therapy.

    PubMed

    Mahanna, G K; Ivanhoe, J R; Attanasio, R A

    1994-06-01

    This article describes the fabrication and modification of a peroral cone-positioning device. The modification provides added cone stability and prevents tongue intrusion into the radiation field. This device provides a repeatable accurate cone/lesion relationship and the fabrication technique is simplified, accurate, and minimizes patient discomfort.

  14. Small Molecules in the Cone Snail Arsenal.

    PubMed

    Neves, Jorge L B; Lin, Zhenjian; Imperial, Julita S; Antunes, Agostinho; Vasconcelos, Vitor; Olivera, Baldomero M; Schmidt, Eric W

    2015-10-16

    Cone snails are renowned for producing peptide-based venom, containing conopeptides and conotoxins, to capture their prey. A novel small-molecule guanine derivative with unprecedented features, genuanine, was isolated from the venom of two cone snail species. Genuanine causes paralysis in mice, indicating that small molecules and not just polypeptides may contribute to the activity of cone snail venom.

  15. Cone selectivity derived from the responses of the retinal cone mosaic to natural scenes.

    PubMed

    Wachtler, Thomas; Doi, Eizaburo; Lee, Te- Won; Sejnowski, Terrence J

    2007-06-18

    To achieve color vision, the brain has to process signals of the cones in the retinal photoreceptor mosaic in a cone-type-specific way. We investigated the possibility that cone-type-specific wiring is an adaptation to the statistics of the cone signals. We analyzed estimates of cone responses to natural scenes and found that there is sufficient information in the higher order statistics of L- and M-cone responses to distinguish between cones of different types, enabling unsupervised learning of cone-type specificity. This was not the case for a fourth cone type with spectral sensitivity between L and M cones, suggesting an explanation for the lack of strong tetrachromacy in heterozygous carriers of color deficiencies.

  16. Cone selectivity derived from the responses of the retinal cone mosaic to natural scenes

    PubMed Central

    Doi, Eizaburo; Lee, Te-Won; Sejnowski, Terrence J.

    2010-01-01

    To achieve color vision, the brain has to process signals of the cones in the retinal photoreceptor mosaic in a cone-type-specific way. We investigated the possibility that cone-type-specific wiring is an adaptation to the statistics of the cone signals. We analyzed estimates of cone responses to natural scenes and found that there is sufficient information in the higher order statistics of L- and M-cone responses to distinguish between cones of different types, enabling unsupervised learning of cone-type specificity. This was not the case for a fourth cone type with spectral sensitivity between L and M cones, suggesting an explanation for the lack of strong tetrachromacy in heterozygous carriers of color deficiencies. PMID:17685813

  17. DOS cones along atomic chains

    NASA Astrophysics Data System (ADS)

    Kwapiński, Tomasz

    2017-03-01

    The electron transport properties of a linear atomic chain are studied theoretically within the tight-binding Hamiltonian and the Green’s function method. Variations of the local density of states (DOS) along the chain are investigated. They are crucial in scanning tunnelling experiments and give important insight into the electron transport mechanism and charge distribution inside chains. It is found that depending on the chain parity the local DOS at the Fermi level can form cone-like structures (DOS cones) along the chain. The general condition for the local DOS oscillations is obtained and the linear behaviour of the local density function is confirmed analytically. DOS cones are characterized by a linear decay towards the chain which is in contrast to the propagation properties of charge density waves, end states and Friedel oscillations in one-dimensional systems. We find that DOS cones can appear due to non-resonant electron transport, the spin–orbit scattering or for chains fabricated on a substrate with localized electrons. It is also shown that for imperfect chains (e.g. with a reduced coupling strength between two neighboring sites) a diamond-like structure of the local DOS along the chain appears.

  18. Gene Therapy Rescues Cone Structure and Function in the 3-Month-Old rd12 Mouse: A Model for Midcourse RPE65 Leber Congenital Amaurosis

    PubMed Central

    Li, Xia; Li, Wensheng; Dai, Xufeng; Kong, Fansheng; Zheng, Qinxiang; Zhou, Xiangtian; Lü, Fan; Chang, Bo; Rohrer, Bärbel; Hauswirth, William. W.; Qu, Jia; Pang, Ji-jing

    2011-01-01

    Purpose. RPE65 function is necessary in the retinal pigment epithelium (RPE) to generate chromophore for all opsins. Its absence results in vision loss and rapid cone degeneration. Recent Leber congenital amaurosis type 2 (LCA with RPE65 mutations) phase I clinical trials demonstrated restoration of vision on RPE65 gene transfer into RPE cells overlying cones. In the rd12 mouse, a naturally occurring model of RPE65-LCA early cone degeneration was observed; however, some peripheral M-cones remained. A prior study showed that AAV-mediated RPE65 expression can prevent early cone degeneration. The present study was conducted to test whether the remaining cones in older rd12 mice can be rescued. Methods. Subretinal treatment with the scAAV5-smCBA-hRPE65 vector was initiated at postnatal day (P)14 and P90. After 2 months, electroretinograms were recorded, and cone morphology was analyzed by using cone-specific peanut agglutinin and cone opsin–specific antibodies. Results. Cone degeneration started centrally and spread ventrally, with cells losing cone-opsin staining before that for the PNA-lectin–positive cone sheath. Gene therapy starting at P14 resulted in almost wild-type M- and S-cone function and morphology. Delaying gene-replacement rescued the remaining M-cones, and most important, more M-cone opsin–positive cells were identified than were present at the onset of gene therapy, suggesting that opsin expression could be reinitiated in cells with cone sheaths. Conclusions. The results support and extend those of the previous study that gene therapy can stop early cone degeneration, and, more important, they provide proof that delayed treatment can restore the function and morphology of the remaining cones. These results have important implications for the ongoing LCA2 clinical trials. PMID:21169527

  19. Hypersonic convective heat transfer over 140-deg blunt cones in different gases

    SciTech Connect

    Stewart, D.A.; Chen, Y.K.

    1994-09-01

    Large-angle blunt cones, with various corner radii, were tested in dissociated air, CO2, and CO2-Ar gas mixtures. These experiments were conducted at angles of attack from 0 to 20 deg. The heating distribution data and how shock-waved geometry were obtained during the cone`s exposure to the three gases. The data can be used to partially validate two-dimensional (2-D) axisymmetric and three-dimensional Navier-Stokes solutions of the heating distribution over a 140-deg blunt cone in a simulated Martian atmosphere. The predicted heating distribution over the cones and estimated bow shock standoff distances using a 2-D axisymmetric Navier-Stokes code were compared with test data taken at zero angle of attack. 18 refs.

  20. Penetrating neck traumas

    PubMed Central

    Kaczmarski, Jacek; Brzeziński, Daniel; Cieślik-Wolski, Bartosz; Kozak, Józef

    2014-01-01

    Aim of the study Aim of the study is to present our own experiences in the treatment of people suffering from penetrating neck traumas. Material and methods In the years 1996-2012, 10 patients with penetrating neck traumas were treated, including 3 women and 7 men. The patients’ age ranged from 16 to 55 (the average age being 40.7 years). In 9 cases the wound was caused by cutting or stabbing, while in one case it was inflicted by a gunshot. In 8 patients it was a single cut wound, while one patient suffered from 34 stab wounds to the neck, chest and stomach. Two cut wounds resulted from a suicide attempt. The remaining injuries were the result of a crime. Results All patients underwent immediate surgery, which involved revision of the neck wounds in 8 cases, one longitudinal sternotomy and one left-sided thoracotomy. The indications for surgery included increased subcutaneous emphysema in 5 patients, bleeding from the wound in 3 patients, and mediastinal hematoma in 2 patients. The damage assessed intraoperatively included tracheal damage in 6 patients, damage to carotid vessels in 3 patients, larynx in 2 patients, thoracic vessels in 2 patients, oesophagus in 1 patient and thyroid gland in 1 patient. In 9 patients, the treatment yielded positive results. The patient with a gunshot wound died during the surgery due to massive bleeding from the aorta. Conclusions In patients with penetrating neck wounds, early and rapid diagnostics allows one to determine the indications for surgery and prevent serious fatal complications. PMID:26336390

  1. Penetrating Fire Extinguisher

    NASA Technical Reports Server (NTRS)

    1985-01-01

    When Feecon Corporation, a manufacturer of fire protection systems, needed a piercing nozzle for larger aircraft, they were assisted by Kennedy Space Center who provided the company with a fire extinguisher with a hard pointed tip that had been developed in case of an orbiter crash landing. The nozzle can penetrate metal skins of aircraft, trains, etc. Feecon obtained a license and now markets its cobra ram piercing nozzle to airport firefighters. Its primary advantage is that the nozzle can be held in one spot during repeated blows of the ram. *This product has been discontinued and is no longer commercially available.

  2. The deep penetrating nevus.

    PubMed

    Strazzula, Lauren; Senna, Maryanne Makredes; Yasuda, Mariko; Belazarian, Leah

    2014-12-01

    The deep penetrating nevus (DPN), also known as the plexiform spindle cell nevus, is a pigmented lesion that commonly arises on the head and neck in the first few decades of life. Histopathologically, the DPN is wedge-shaped and contains melanocytes that exhibit deep infiltration into the dermis. Given these features, DPN may clinically and histopathologically mimic malignant melanoma, sparking confusion about the appropriate evaluation and management of these lesions. The goal of this review is to summarize the clinical and histopathological features of DPN and to discuss diagnostic and treatment strategies for dermatologists.

  3. CONE - An STS-based cryogenic fluid management experiment

    NASA Technical Reports Server (NTRS)

    Bell, R. S.; Vento, D. M.; Hanna, G. J.

    1992-01-01

    An overview of the CONE program is presented which includes a definition of the technology addressed by CONE and a baseline experiment set, a description of the experimental and support subsystems, interface requirements between the STS and the experiment carrier (Hitchhiker M), and the reusability and expansion capacity for additional experiment flights. CONE evaluates three primary technologies: the active thermodynamic vent system, the passive thermodynamic vent system, and liquid acquisition device performance. The cryogenic fluid management technology database that the system offers will allow for efficient subcritical cryogenic system designs for operation in a low-gravity environment. This system maximizes the balance between existing component technology and the need for the development of a cryogenic-fluid-management (CFM) test bed to investigate and demonstrate methods of storage and handling arenas.

  4. 63. Historic detail drawing of inlet duct cone on exhaust ...

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

    63. Historic detail drawing of inlet duct cone on exhaust scrubber at building 202, June 18, 1955. NASA GRC drawing no. CD-101266. (On file at NASA Glenn Research Center). - Rocket Engine Testing Facility, GRC Building No. 202, NASA Glenn Research Center, Cleveland, Cuyahoga County, OH

  5. Directional imaging of the retinal cone mosaic.

    PubMed

    Vohnsen, Brian; Iglesias, Ignacio; Artal, Pablo

    2004-05-01

    We describe a near-IR scanning laser ophthalmoscope that allows the retinal cone mosaic to be imaged in the human eye in vivo without the use of wave-front correction techniques. The method takes advantage of the highly directional quality of cone photoreceptors that permits efficient coupling of light to individual cones and subsequent detection of most directional components of the backscattered light produced by the light-guiding effect of the cones. We discuss details of the system and describe cone-mosaic images obtained under different conditions.

  6. Monolithic ballasted penetrator

    DOEpatents

    Hickerson, Jr., James P.; Zanner, Frank J.; Baldwin, Michael D.; Maguire, Michael C.

    2001-01-01

    The present invention is a monolithic ballasted penetrator capable of delivering a working payload to a hardened target, such as reinforced concrete. The invention includes a ballast made from a dense heavy material insert and a monolithic case extending along an axis and consisting of a high-strength steel alloy. The case includes a nose end containing a hollow portion in which the ballast is nearly completely surrounded so that no movement of the ballast relative to the case is possible during impact with a hard target. The case is cast around the ballast, joining the two parts together. The ballast may contain concentric grooves or protrusions that improve joint strength between the case and ballast. The case further includes a second hollow portion; between the ballast and base, which has a payload fastened within this portion. The penetrator can be used to carry instrumentation to measure the geologic character of the earth, or properties of arctic ice, as they pass through it.

  7. Penetration in GTA welding

    SciTech Connect

    Heiple, C.R.; Burgardt, P.

    1990-01-01

    The size and shape of the weld bead produced in GTA welding depends on the magnitude and distribution of the energy incident on the workpiece surfaces as well as the dissipation of that energy in the workpiece. The input energy is largely controllable through the welding parameters selected, however the dissipation of that energy in the workpiece is less subject to control. Changes in energy dissipation can produce large changes in weld shape or penetration. Heat transport away from the weld pool is almost entirely by conduction, but heat transport in the weld pool is more complicated. Heat conduction through the liquid is an important component, but heat transport by convection (mass transport) is often the dominant mechanism. Convective heat transport is directional and changes the weld pool shape from that produced by conduction alone. Surface tension gradients are often the dominant forces driving fluid flow in GTA weld pools. These gradients are sensitive functions of weld pool chemistry and the energy input distribution to the weld. Experimental and theoretical work conducted primarily in the past decade has greatly enhanced our understanding of weld pool fluid flow, the forces which drive it, and its effects on weld pool shape. This work is reviewed here. While less common, changes in energy dissipation through the unmelted portion of the workpiece can also affect fusion zone shape or penetration. These effects are also described. 41 refs., 9 figs.

  8. Superior cell penetration by a rigid and anisotropic synthetic protein.

    PubMed

    Nakayama, Norihisa; Hagiwara, Kyoji; Ito, Yoshihiro; Ijiro, Kuniharu; Osada, Yoshihito; Sano, Ken-Ichi

    2015-03-10

    Molecules with structural anisotropy and rigidity, such as asbestos, demonstrate high cell-penetrating activity but also high toxicity. Here we synthesize a biodegradable, rigid, and fibrous artificial protein, CCPC 140, as a potential vehicle for cellular delivery. CCPC 140 penetrated 100% of cells tested in vitro, even at a concentration of 3.1 nM-superior to previously reported cell-penetrating peptides. The effects of cell-strain-dependency and aspect ratio on the cell-penetrating activity of CCPC 140 were also investigated.

  9. Journey of water in pine cones

    PubMed Central

    Song, Kahye; Yeom, Eunseop; Seo, Seung-Jun; Kim, Kiwoong; Kim, Hyejeong; Lim, Jae-Hong; Joon Lee, Sang

    2015-01-01

    Pine cones fold their scales when it rains to prevent seeds from short-distance dispersal. Given that the scales of pine cones consist of nothing but dead cells, this folding motion is evidently related to structural changes. In this study, the structural characteristics of pine cones are studied on micro-/macro-scale using various imaging instruments. Raindrops fall along the outer scales to the three layers (bract scales, fibers and innermost lignified structure) of inner pine cones. However, not all the layers but only the bract scales get wet and then, most raindrops move to the inner scales. These systems reduce the amount of water used and minimize the time spent on structural changes. The result shows that the pine cones have structural advantages that could influence the efficient motion of pine cones. This study provides new insights to understand the motion of pine cones and would be used to design a novel water transport system. PMID:25944117

  10. Journey of water in pine cones

    NASA Astrophysics Data System (ADS)

    Song, Kahye; Yeom, Eunseop; Seo, Seung-Jun; Kim, Kiwoong; Kim, Hyejeong; Lim, Jae-Hong; Joon Lee, Sang

    2015-05-01

    Pine cones fold their scales when it rains to prevent seeds from short-distance dispersal. Given that the scales of pine cones consist of nothing but dead cells, this folding motion is evidently related to structural changes. In this study, the structural characteristics of pine cones are studied on micro-/macro-scale using various imaging instruments. Raindrops fall along the outer scales to the three layers (bract scales, fibers and innermost lignified structure) of inner pine cones. However, not all the layers but only the bract scales get wet and then, most raindrops move to the inner scales. These systems reduce the amount of water used and minimize the time spent on structural changes. The result shows that the pine cones have structural advantages that could influence the efficient motion of pine cones. This study provides new insights to understand the motion of pine cones and would be used to design a novel water transport system.

  11. Modeling of Oblique Penetration into Geologic Targets Using Cavity Expansion Penetrator Loading with Target free-Surface Effects

    SciTech Connect

    Jung, Joe; Longcope, Donald B.; Tabbara, Mazen R.

    1999-05-03

    A procedure has been developed to represent the loading on a penetrator and its motion during oblique penetration into geologic media. The penetrator is modeled with the explicit dynamics, finite element computer program PRONTO 3D and the coupled pressure on the penetrator is given in a new loading option based on a separate cavity expansion (CE) solution that accounts for the pressure-reduction from a nearby target free surface. The free-surface influ- ence distance is selected in a predictive manner by considering the pressure to expand a spherical cavity in a finite radius sphere of the target material. The CE/PRONTO 3D procedure allows a detailed description of the penetrator for predicting shock environments or structural failure dur- ing the entire penetration event and is sufficiently rapid to be used in design optimization. It has been evaluated by comparing its results with data from two field tests of a full-scale penetrator into frozen soil at an impact angles of 49.6 and 52.5 degrees from the horizontal. The measured penetrator rotations were 24 and 22 degrees, respectively. In the simulation, the rotation was21 degrees and predominately resulted from the pressure reduction of the free surface. Good agree- ment was also found for the penetration depth and axial and lateral acceleration at two locations in the penetrator.

  12. Calcium regulates vesicle replenishment at the cone ribbon synapse.

    PubMed

    Babai, Norbert; Bartoletti, Theodore M; Thoreson, Wallace B

    2010-11-24

    Cones release glutamate-filled vesicles continuously in darkness, and changing illumination modulates this release. Because sustained release in darkness is governed by vesicle replenishment rates, we analyzed how cone membrane potential regulates replenishment. Synaptic release from cones was measured by recording postsynaptic currents in Ambystoma tigrinum horizontal or OFF bipolar cells evoked by depolarization of simultaneously voltage-clamped cones. We measured replenishment after attaining a steady state between vesicle release and replenishment using trains of test pulses. Increasing Ca(2+) currents (I(Ca)) by changing the test step from -30 to -10 mV increased replenishment. Lengthening -30 mV test pulses to match the Ca(2+) influx during 25 ms test pulses to -10 mV produced similar replenishment rates. Reducing Ca(2+) driving force by using test steps to +30 mV slowed replenishment. Using UV flashes to reverse inhibition of I(Ca) by nifedipine accelerated replenishment. Increasing [Ca(2+)](i) by flash photolysis of caged Ca(2+) also accelerated replenishment. Replenishment, but not the initial burst of release, was enhanced by using an intracellular Ca(2+) buffer of 0.5 mm EGTA rather than 5 mm EGTA, and diminished by 1 mm BAPTA. This suggests that although release and replenishment exhibited similar Ca(2+) dependencies, release sites are <200 nm from Ca(2+) channels but replenishment sites are >200 nm away. Membrane potential thus regulates replenishment by controlling Ca(2+) influx, principally by effects on replenishment mechanisms but also by altering releasable pool size. This in turn provides a mechanism for converting changes in light intensity into changes in sustained release at the cone ribbon synapse.

  13. Finite Element Modeling of Transient Head Field Associated with Partially Penetrating, Slug Tests in a Heterogeneous Aquifer with Low Permeability, Stratigraphic Zones and Faults

    NASA Astrophysics Data System (ADS)

    Cheng, J.; Johnson, B.; Everett, M.

    2003-12-01

    Preliminary field work shows slug interference tests using an array of multilevel active and monitoring wells have potential of permitting enhanced aquifer characterization. Analysis of these test data, however, ultimately will rely on numerical geophysical inverse models. In order to gain insight as well as to provide synthetic data sets, we use a 3-D finite element analysis (code:FEHM-LANL) to explore the effect of idealized, low permeability, stratigraphical and structural (faults) heterogeneities on the transient head field associated with a slug test in a packer-isolated interval of an open borehole. The borehole and packers are modeled explicitly; wellbore storage is selected to match values of field tests. The homogeneous model exhibits excellent agreement with that of the semi-analytical model of Liu and Butler (1995). Models are axisymmetric with a centrally located slugged interval within a homogenous, isotropic, confined aquifer with embedded, horizontal or vertical zones of lower permeability that represent low permeability strata or faults, respectively. Either one or two horizontal layers are located opposite the borehole packers, which is a common situation at the field site; layer thickness (0.15-0.75 m), permeability contrast (up to 4 orders of magnitude contrast) and lateral continuity of layers are varied between models. The effect of a "hole" in a layer also is assessed. Fault models explore effects of thickness (0.05-0.75 m) and permeability contrast as well as additional effects associated with the offset of low permeability strata. Results of models are represented most clearly by contour maps of time of arrival and normalized amplitude of peak head perturbation, but transient head histories at selected locations provide additional insight. Synthesis of the models is on-going but a few points can be made at present. Spatial patterns are distinctive and allow easy discrimination between stratigraphic and structural impedance features. Time

  14. Physical properties of thin-film field emission cathodes with molybdenum cones

    NASA Technical Reports Server (NTRS)

    Spindt, C. A.; Brodie, I.; Humphrey, L.; Westerberg, E. R.

    1976-01-01

    Field emission cathodes fabricated using thin-film techniques and electron beam microlithography are described, together with effects obtained by varying the fabrication parameters. The emission originates from the tip of molybdenum cones that are about 1.5 micron tall with a tip radius around 500 A. Such cathodes have been produced in closely packed arrays containing 100 and 5000 cones as well as singly. Maximum currents in the range 50-150 microamp per cone can be drawn. Life tests with the 100-cone arrays drawing 2 mA total emission (or 3 A per sq cm) have proceeded in excess of 7000 hr with about a 10% drop in emission current. Studies are presented of the emission characteristics and current fluctuation phenomena. It is tentatively concluded that the emission arises from only one or a few atomic sites on the cone tips.

  15. Minimum rotation speed to prevent coning phenomena in compendium paddle dissolution apparatus.

    PubMed

    Higuchi, Mizuki; Yoshihashi, Yasuo; Tarada, Katsuhide; Sugano, Kiyohiko

    2014-12-18

    The purpose of the present study was to investigate the applicability of the Zwietering equation to coning phenomena which often occur during dissolution testing. The minimum rotation speed at which coning phenomena disappeared (no coning rpm, NCrpm) was experimentally determined for various particle and fluid properties in a compendium paddle apparatus with a round-bottom unbaffled vessel. The particle size, relative density and kinematic viscosity exponents in the Zwietering equation were optimized for NCrpm. The particle size and relative density exponents were found to be similar with those for the general tank configurations of cylindrical flat-bottom baffled vessels. However, the kinematic viscosity exponent was significantly different. The equation obtained in this study showed sufficient accuracy (r(2)=0.98, average error=12rpm) to estimate the occurrence of coning. The Zwietering equation was found to be applicable to the coning phenomena in the compendium paddle apparatus.

  16. S-cone discrimination in the presence of two adapting fields: data and model.

    PubMed

    Cao, Dingcai

    2014-04-01

    This study investigated S-cone discrimination using a test annulus surrounded by an inner and outer adapting field with systematic manipulation of the adapting l=L/(L+M) or s=S/(L+M) chromaticities. The results showed that different adapting l chromaticities altered S-cone discrimination for a high adapting s chromaticity due to parvocellular input to the koniocellular pathway. In addition, S-cone discrimination was determined by the combined spectral signals arising from both adapting fields. The "white" adapting field or an adapting field with a different l chromaticity from the other fields was more likely to have a stronger influence on discrimination thresholds. These results indicated that the two cardinal axes are not independent in S-cone discrimination, and the two adapting fields jointly contribute to S-cone discrimination through a cortical summation mechanism.

  17. Diagnosis of Normal and Abnormal Color Vision with Cone-Specific VEPs

    PubMed Central

    Rabin, Jeff C.; Kryder, Andrew C.; Lam, Dan

    2016-01-01

    Purpose Normal color vision depends on normal long wavelength (L), middle wavelength (M), and short wavelength sensitive (S) cones. Hereditary “red-green” color vision deficiency (CVD) is due to a shift in peak sensitivity or lack of L or M cones. Hereditary S cone CVD is rare but can be acquired as an early sign of disease. Current tests detect CVD but few diagnose type or severity, critical for linking performance to real-world demands. The anomaloscope and newer subjective tests quantify CVD but are not applicable to infants or cognitively impaired patients. Our purpose was to develop an objective test of CVD with sensitivity and specificity comparable to current tests. Methods A calibrated visual-evoked potential (VEP) display and Food and Drug Administration-approved system was used to record L, M, and S cone-specific pattern-onset VEPs from 18 color vision normals (CVNs) and 13 hereditary CVDs. VEP amplitudes and latencies were compared between groups to establish VEP sensitivity and specificity. Results Cone VEPs show 100% sensitivity for diagnosis of CVD and 94% specificity for confirming CVN. L cone (protan) CVDs showed a significant increase in L cone latency (53.1 msec, P < 0.003) and decreased amplitude (10.8 uV, P < 0.0000005) but normal M and S cone VEPs (P > 0.31). M cone (deutan) CVDs showed a significant increase in M cone latency (31.0 msec, P < 0.000004) and decreased amplitude (8.4 uV, P < 0.006) but normal L and S cone VEPs (P > 0.29). Conclusions Cone-specific VEPs offer a rapid, objective test to diagnose hereditary CVD and show potential for detecting acquired CVD in various diseases. Translational Relevance This paper describes the efficacy of cone-specific color VEPs for quantification of normal and abnormal color vision. The rapid, objective nature of this approach makes it suitable for detecting color sensitivity loss in infants and the cognitively impaired. PMID:27226932

  18. Cardiac cone-beam CT

    SciTech Connect

    Manzke, Robert . E-mail: robert.manzke@philips.com

    2005-10-15

    This doctoral thesis addresses imaging of the heart with retrospectively gated helical cone-beam computed tomography (CT). A thorough review of the CT reconstruction literature is presented in combination with a historic overview of cardiac CT imaging and a brief introduction to other cardiac imaging modalities. The thesis includes a comprehensive chapter about the theory of CT reconstruction, familiarizing the reader with the problem of cone-beam reconstruction. The anatomic and dynamic properties of the heart are outlined and techniques to derive the gating information are reviewed. With the extended cardiac reconstruction (ECR) framework, a new approach is presented for the heart-rate-adaptive gated helical cardiac cone-beam CT reconstruction. Reconstruction assessment criteria such as the temporal resolution, the homogeneity in terms of the cardiac phase, and the smoothness at cycle-to-cycle transitions are developed. Several reconstruction optimization approaches are described: An approach for the heart-rate-adaptive optimization of the temporal resolution is presented. Streak artifacts at cycle-to-cycle transitions can be minimized by using an improved cardiac weighting scheme. The optimal quiescent cardiac phase for the reconstruction can be determined automatically with the motion map technique. Results for all optimization procedures applied to ECR are presented and discussed based on patient and phantom data. The ECR algorithm is analyzed for larger detector arrays of future cone-beam systems throughout an extensive simulation study based on a four-dimensional cardiac CT phantom. The results of the scientific work are summarized and an outlook proposing future directions is given. The presented thesis is available for public download at www.cardiac-ct.net.

  19. Missile and Spacecraft Coning Instabilities

    DTIC Science & Technology

    2007-11-02

    181-192. "Mingori, D. L., and Yam, T., " Nutational Stability of a Spinning Space- craft with Internal Mass Motion and Axial Thrust," AIAA Paper 86...Nomenclature 1 Introduction 1 Equations of Motion 2 Yaw Moment Damping or Undamping 2 Spacecraft Precession Damper 3 Vehicle Coning with Axial ...with Axial Thrust and Variable Mass The variable mass accompanying thrust from a spin-stabilized rocket motor or PAM produces a destabilizing effect

  20. Bursting the Taylor cone bubble

    NASA Astrophysics Data System (ADS)

    Pan, Zhao; Truscott, Tadd

    2014-11-01

    A soap bubble fixed on a surface and placed in an electric field will take on the shape of a cone rather than constant curvature (dome) when the electrical field is not present. The phenomenon was introduced by J. Zeleny (1917) and studied extensively by C.T. Wilson & G.I. Taylor (1925). We revisit the Taylor cone problem by studying the deformation and bursting of soap bubbles in a point charge electric field. A single bubble takes on the shape of a cone in the electric field and a high-speed camera equipped with a micro-lens is used to observe the unsteady dynamics at the tip. Rupture occurs as a very small piece of the tip is torn away from the bubble toward the point charge. Based on experiments, a theoretical model is developed that predicts when rupture should occur. This study may help in the design of foam-removal techniques in engineering and provide a better understanding of an electrified air-liquid interface.

  1. Spatial structure of cone inputs to receptive fields in primate lateral geniculate nucleus

    NASA Astrophysics Data System (ADS)

    Reid, R. Clay; Shapley, Robert M.

    1992-04-01

    HUMAN colour vision depends on three classes of cone photoreceptors, those sensitive to short (S), medium (M) or long (L) wavelengths, and on how signals from these cones are combined by neurons in the retina and brain. Macaque monkey colour vision is similar to human, and the receptive fields of macaque visual neurons have been used as an animal model of human colour processing1. P retinal ganglion cells and parvocellular neurons are colour-selective neurons in macaque retina and lateral geniculate nucleus. Interactions between cone signals feeding into these neurons are still unclear. On the basis of experimental results with chromatic adaptation, excitatory and inhibitory inputs from L and M cones onto P cells (and parvocellular neurons) were thought to be quite specific2,3 (Fig. la). But these experiments with spatially diffuse adaptation did not rule out the 'mixed-surround' hypothesis: that there might be one cone-specific mechanism, the receptive field centre, and a surround mechanism connected to all cone types indiscriminately (Fig. le). Recent work has tended to support the mixed-surround hypothesis4-8. We report here the development of new stimuli to measure spatial maps of the linear L-, M- and S-cone inputs to test the hypothesis definitively. Our measurements contradict the mixed-surround hypothesis and imply cone specificity in both centre and surround.

  2. Temperature matching of multilayer insulation to penetrations

    NASA Astrophysics Data System (ADS)

    Johnson, W. L.; Plachta, D. W.; Rhys, N. O.; Kelly, A. O.

    2014-01-01

    To accurately predict the heat load into a cryogenic tank or cold mass which includes multilayer insulation (MLI), heat loads other than just through the pristine MLI must be accounted for. One such type of heat load is the integration of the MLI system around penetrations. While a number of different methods that have been developed, the ideal solution would be one in which there are zero thermal losses due to the integration. Theoretically, the be st method to achieving zero integration losses is to match the individual MLI temperature layers with the corresponding penetration location having the same temperature; this method is known as temperature matching. Recently, NASA has employed temperature matching integration of multilayer insulation systems onto several different cryogenic tanks with different structural elements and attachments. T esting included the Methane Lunar Surface Thermal Control testing at Glenn Research Center, the CRYOTE Ground Test Article testing at Marshall Space Flight Center, and the Penetration Calorimetery work done at Kennedy Space Center. Each test was instrumented to determine the effects of temperature matching within MLI and each system was designed in a different manner. The testing showed that temperature matching can indeed produce nearly zero thermal losses. However, our findings show that there are many practical limitations to this approach. Temperature matching integration schemes were found to be very sensitive to thermal environmental changes and even tank liquid level changes. The approach is therefore considered useful only for a select few cases and not useful for most engineering applications.

  3. Mechanical sensing of the penetration of various nanoneedles into a living cell using atomic force microscopy.

    PubMed

    Obataya, Ikuo; Nakamura, Chikashi; Han, SungWoong; Nakamura, Noriyuki; Miyake, Jun

    2005-02-15

    Mechanical responses during insertion of a silicon nanoneedle into a living melanocyte were observed by using an atomic force microscope (AFM). In order to study the dependence of the mechanical response on the shape of the nanoneedle, we prepared various shapes of silicon AFM tips by focused-ion beam (FIB) etching. The force curves showed increases up to 0.65-1.9 nN after contact on the cell surface, and then the force dropped corresponding with the penetration of the needle through the cell membrane. The force required for penetration was significantly smaller than that using a normal pyramidal tip. The force curves with a cylindrical tip showed a shorter indenting distance before penetration than that with the cone-shaped tip. It is considered that the information about the geometry of penetrating material leads to the development of more suitable micro- and nano-materials to insert into a living cell for cell surgery.

  4. Cone Penetrometer Off-Surface Sensor

    SciTech Connect

    Smail, T.R.; French, p.J.; Huffman, R.K.; Hebert, P.S.

    1999-10-20

    Cone penetrometer technology accounts for approximately 50 percent of the subsurface drilling done at the Savannah River Site. This technology provides a means of collecting data for use in the characterization of the subsurface. The cone penetrometer consists of a steel cone attached to a pipe column that is hydraulically inserted into the ground. To allow researchers to accurately measure subsurface properties, without the inherent problems of cone penetrometer equipment, the Savannah River Technology Center has developed the Cone Penetrometer Off-Surface Sensor (CPOSS). The CPOSS design consists of a knife-blade mechanism mounted along the surface of a module capable of attaching to existing cone penetrometer equipment and being deployed at depths of up to 200 feet. CPOSS development is the subject of this report.

  5. Sidewall penetrator for oil wells

    NASA Technical Reports Server (NTRS)

    Collins, E. R., Jr.

    1981-01-01

    Penetrator bores horizontal holes in well casing to increase trapped oil drainage. Several penetrators operated by common drive are inserted into well at once. Shaft, made from spiraling cable, rotates and thrusts simultaneously through rigid curvilinear guide tube forcing bit through casing into strata. Device pierces more deeply than armor-piercing bullets and shaped explosive charges.

  6. Failure Engineered Heavy Metal Penetrators

    DTIC Science & Technology

    1992-12-01

    ARMY RESEARCH LABORATORY Failure Engineered Heavy Metal Penetrators, Phase I, SBIR ARL-CR-5· R. Cavalieri, W. Tiarn, and D. Nicholson prepared...REPORT DATE S. REPORT TYPE AND DATES COVERED December 1992 Final Report-1/1/92 - 7/31/92 4. TITLE AND SUBTITLE FAILURE ENGINEERED HEAVY METAL PENETRATORS

  7. Electromagnetic Field Penetration Studies

    NASA Technical Reports Server (NTRS)

    Deshpande, M.D.

    2000-01-01

    A numerical method is presented to determine electromagnetic shielding effectiveness of rectangular enclosure with apertures on its wall used for input and output connections, control panels, visual-access windows, ventilation panels, etc. Expressing EM fields in terms of cavity Green's function inside the enclosure and the free space Green's function outside the enclosure, integral equations with aperture tangential electric fields as unknown variables are obtained by enforcing the continuity of tangential electric and magnetic fields across the apertures. Using the Method of Moments, the integral equations are solved for unknown aperture fields. From these aperture fields, the EM field inside a rectangular enclosure due to external electromagnetic sources are determined. Numerical results on electric field shielding of a rectangular cavity with a thin rectangular slot obtained using the present method are compared with the results obtained using simple transmission line technique for code validation. The present technique is applied to determine field penetration inside a Boeing-757 by approximating its passenger cabin as a rectangular cavity filled with a homogeneous medium and its passenger windows by rectangular apertures. Preliminary results for, two windows, one on each side of fuselage were considered. Numerical results for Boeing-757 at frequencies 26 MHz, 171-175 MHz, and 428-432 MHz are presented.

  8. Top Sounder Ice Penetration

    NASA Astrophysics Data System (ADS)

    Porter, D. L.; Goemmer, S. A.; Sweeney, J. H.

    2014-12-01

    Ice draft measurements are made as part of normal operations for all US Navy submarines operating in the Arctic Ocean. The submarine ice draft data are unique in providing high resolution measurements over long transects of the ice covered ocean. The data has been used to document a multidecadal drop in ice thickness, and for validating and improving numerical sea-ice models. A submarine upward-looking sonar draft measurement is made by a sonar transducer mounted in the sail or deck of the submarine. An acoustic beam is transmitted upward through the water column, reflecting off the bottom of the sea ice and returning to the transducer. Ice thickness is estimated as the difference between the ship's depth (measured by pressure) and the acoustic range to the bottom of the ice estimated from the travel time of the sonar pulse. Digital recording systems can provide the return off the water-ice interface as well as returns that have penetrated the ice. Typically, only the first return from the ice hull is analyzed. Information regarding ice flow interstitial layers provides ice age information and may possibly be derived with the entire return signal. The approach being investigated is similar to that used in measuring bottom sediment layers and will involve measuring the echo level from the first interface, solving the reflection loss from that transmission, and employing reflection loss versus impedance mismatch to ascertain ice structure information.

  9. Programming Retinal Stem Cells into Cone Photoreceptors

    DTIC Science & Technology

    2015-12-01

    to program human stem cells directly into cones. Using RNA -seq, we identified several genes that are upregulated in advance of the earliest...reverse vision loss. 15. SUBJECT TERMS Cone photoreceptor, retina, retinal stem cell, Otx2, Onecut1, Blimp1, RNA -seq., transcription factors, and...1 Keywords: 1. Cone photoreceptor 2. Retina 3. Retinal stem cell 4. Otx2 5. Onecut1 6. Blimp1 7. RNA -seq. 8. Transcription factors 9

  10. Cone opsins, colour blindness and cone dystrophy: Genotype-phenotype correlations.

    PubMed

    Gardner, J C; Michaelides, M; Hardcastle, A J

    2016-05-25

    X-linked cone photoreceptor disorders caused by mutations in the OPN1LW (L) and OPN1MW (M) cone opsin genes on chromosome Xq28 include a range of conditions from mild stable red-green colour vision deficiencies to severe cone dystrophies causing progressive loss of vision and blindness. Advances in molecular genotyping and functional analyses of causative variants, combined with deep retinal phenotyping, are unravelling genetic mechanisms underlying the variability of cone opsin disorders.

  11. Unilateral retinitis pigmentosa and cone-rod dystrophy

    PubMed Central

    Farrell, Donald F

    2009-01-01

    Purpose: The purpose of this paper is to report 14 new cases of unilateral retinitis pigmentosa and three new cases of cone-rod dystrophy and to compare the similarities and dissimilarities to those found in the bilateral forms of these disorders. Methods: A total of 272 cases of retinitis pigmentosa and 167 cases of cone-rod dystrophy were studied by corneal full field electroretinograms and electrooculograms. The student t-test was used to compare categories. Results: The percentage of familial and nonfamilial cases was the same for the bilateral and unilateral forms of the disease. In our series, unilateral retinitis pigmentosa makes up approximately 5% of the total population of retinitis pigmentosa, while unilateral cone-rod dystrophy makes up only about 2% of the total. In the familial forms of unilateral retinitis pigmentosa the most common inheritance pattern was autosomal dominant and all affected relatives had bilateral disease. Conclusion: Unilateral retinitis pigmentosa and cone-rod dystrophy appear to be directly related to the more common bilateral forms of these disorders. The genetic mechanisms which account for asymmetric disorders are not currently understood. It may be a different unidentified mutation at a single loci or it is possible that nonlinked mutations in multiple loci account for this unusual disorder. PMID:19668577

  12. ASC-AD penetration modeling FY05 status report.

    SciTech Connect

    Kistler, Bruce L.; Ostien, Jakob T.; Chiesa, Michael L.; Bhutani, Nipun; Ohashi, Yuki; Marin, Esteban B.; Korellis, John S.; Settgast, Randy; Antoun, Bonnie R.

    2006-04-01

    Sandia currently lacks a high fidelity method for predicting loads on and subsequent structural response of earth penetrating weapons. This project seeks to test, debug, improve and validate methodologies for modeling earth penetration. Results of this project will allow us to optimize and certify designs for the B61-11, Robust Nuclear Earth Penetrator (RNEP), PEN-X and future nuclear and conventional penetrator systems. Since this is an ASC Advanced Deployment project the primary goal of the work is to test, debug, verify and validate new Sierra (and Nevada) tools. Also, since this project is part of the V&V program within ASC, uncertainty quantification (UQ), optimization using DAKOTA [1] and sensitivity analysis are an integral part of the work. This project evaluates, verifies and validates new constitutive models, penetration methodologies and Sierra/Nevada codes. In FY05 the project focused mostly on PRESTO [2] using the Spherical Cavity Expansion (SCE) [3,4] and PRESTO Lagrangian analysis with a preformed hole (Pen-X) methodologies. Modeling penetration tests using PRESTO with a pilot hole was also attempted to evaluate constitutive models. Future years work would include the Alegra/SHISM [5] and AlegrdEP (Earth Penetration) methodologies when they are ready for validation testing. Constitutive models such as Soil-and-Foam, the Sandia Geomodel [6], and the K&C Concrete model [7] were also tested and evaluated. This report is submitted to satisfy annual documentation requirements for the ASC Advanced Deployment program. This report summarizes FY05 work performed in the Penetration Mechanical Response (ASC-APPS) and Penetration Mechanics (ASC-V&V) projects. A single report is written to document the two projects because of the significant amount of technical overlap.

  13. Standard Penetration Test and Relative Density

    DTIC Science & Technology

    1971-02-01

    Se OPSeS Debido a que el agua subterranea granclemente influve la resistencia a suelo, se establecio una relacion empirica entre el nurmero de golpes ...sobre el nivel freatico) con la misma densidad relativa. Asimisnmo, porque se encontr6 que el nu.- mero de golpes depende no solo de la densidad

  14. Penetration Testing Curriculum Development in Practice

    ERIC Educational Resources Information Center

    Li, Chengcheng

    2015-01-01

    As both the frequency and the severity of network breaches have increased in recent years, it is essential that cybersecurity is incorporated into the core of business operations. Evidence from the U.S. Bureau of Labor Statistics (Bureau of Labor Statistics, 2012) indicates that there is, and will continue to be, a severe shortage of cybersecurity…

  15. Nested-cone transformer antenna

    DOEpatents

    Ekdahl, C.A.

    1991-05-28

    A plurality of conical transmission lines are concentrically nested to form an output antenna for pulsed-power, radio-frequency, and microwave sources. The diverging conical conductors enable a high power input density across a bulk dielectric to be reduced below a breakdown power density at the antenna interface with the transmitting medium. The plurality of cones maintain a spacing between conductors which minimizes the generation of high order modes between the conductors. Further, the power input feeds are isolated at the input while enabling the output electromagnetic waves to add at the transmission interface. Thus, very large power signals from a pulse rf, or microwave source can be radiated. 6 figures.

  16. Nested-cone transformer antenna

    DOEpatents

    Ekdahl, Carl A.

    1991-01-01

    A plurality of conical transmission lines are concentrically nested to form n output antenna for pulsed-power, radio-frequency, and microwave sources. The diverging conical conductors enable a high power input density across a bulk dielectric to be reduced below a breakdown power density at the antenna interface with the transmitting medium. The plurality of cones maintain a spacing between conductors which minimizes the generation of high order modes between the conductors. Further, the power input feeds are isolated at the input while enabling the output electromagnetic waves to add at the transmission interface. Thus, very large power signals from a pulse rf, or microwave source can be radiated.

  17. Fertilization in Discoglossus pictus (Anura). I. Sperm-egg interactions in distinct regions of the dimple and occurrence of a late stage of sperm penetration.

    PubMed

    Talevi, R; Campanella, C

    1988-12-01

    The heterogeneity of the egg surface with respect to receptivity to sperm was investigated in Discoglossus pictus; in this species fertilization occurs only in an indentation called the dimple, at the center of the animal hemisphere. Following insemination sperm are seen in the outermost jelly layers and in the lens-shaped jelly plug, converging to the dimple center, D1. A fertilization potential (FP) is recorded 30 sec following insemination. About 30 min after fertilization, when fertilization cones can be detected easily, immotile sperm are found at the center of the cone, where 10 min later they accomplish penetration. After 15 min the cone regresses and the second polar body is extruded. In eggs where the plug was experimentally displaced with respect to the dimple, spermatozoa contacted the sides of the dimple and simple protrusions formed but not cones. Spermatozoa do not elicit a normal FP in these regions but small step depolarizations which may be followed by a gradual rise to a positive plateau potential. Such eggs do not develop. In the protrusions, sperm may be only partially incorporated and the unpenetrated portion appears to degenerate. We conclude that at least two regions exist in the dimple: D1, where the FP is triggered, cones are formed, sperm penetration is fully accomplished and development is initiated; and D2 + D3 where the electrical response is not a normal FP, cones do not form, total sperm penetration does not occur, and development is not initiated.

  18. Elevated Temperature Fracture Toughness and Fatigue Testing of Steels for Geothermal Applications

    SciTech Connect

    Cutler, R.A.; Goodman, E.C.; Hendrickson, R.R.

    1981-10-01

    Conventional drill bit steels exhibit increased wear and decreased toughness when run at elevated temperatures in geothermal wells. Bits are therefore run at lower speeds and lighter loads, resulting in lower penetration rates for geothermal drilling than for conventional rock drilling. Carpenter EX-00053, Timken CBS 600, Timken CBS 1000M and Vasco X-2M steels with improved hot hardness (improved wear resistance), were tested in conjunction with the steels used for cones (AISI 4829, 3915 and EX55) in conventional roller cones and lugs (AISI 8620, 9315 and EX55) in conventional roller cone rock bits. Short-rod fracture toughness measurements were made on each of these steels between room temperature and 400{degree}C. Fatigue crack resistance was determined at 300{degree}C for high-temperature steels and at room temperature for conventional steels. Scanning electron microscopy analyses of the fractured short-rod specimens were correlated with observed crack behavior from the test records. Materials testing results are discussed and steel selections made for improved geothermal bits. Carpenter EX-00053 and Timken CBS 1000M steels meet all design requirements for use in stabilizers, lugs and cones at temperatures to 400{degree}C. It is recommended that EX-00053 and CBS 1000M be manufactured for geothermal drilling at the Geysers site. [DJE 2005

  19. Evaporation and skin penetration characteristics of mosquito repellent formulations

    SciTech Connect

    Reifenrath, W.G.; Hawkins, G.S.; Kurtz, M.S.

    1989-03-01

    Formulations of the mosquito repellent N,N-diethyl-3-methylbenzamide (deet) in combination with a variety of additives were developed to control repellent evaporation and percutaneous penetration. Deet was also formulated with the repellent dimethyl phthalate to study the interaction of the two compounds on the skin. The evaporation and penetration processes were evaluated on whole and split-thickness pig skin using radiolabeled repellents with an in vitro apparatus. Under essentially still air and air flow conditions, one of the deet formulations resulted in significantly reduced total evaporation and percutaneous penetration of deet as compared to unformulated repellent. When deet and dimethyl phthalate were combined, neither repellent affected the total amount of evaporation and penetration of the other compound. However, initial percutaneous penetration and evaporation rates were slightly less and decayed less rapidly than when both chemicals were tested separately at the same dose. These results indicated a degree of competition of the two compounds for the same avenues of loss.

  20. Phenotypic Characteristics Including In Vivo Cone Photoreceptor Mosaic in KCNV2-Related “Cone Dystrophy with Supernormal Rod Electroretinogram”

    PubMed Central

    Vincent, Ajoy; Wright, Tom; Garcia-Sanchez, Yaiza; Kisilak, Marsha; Campbell, Melanie; Westall, Carol; Héon, Elise

    2013-01-01

    Purpose To report phenotypic characteristics including macular cone photoreceptor morphology in KCNV2-related “cone dystrophy with supernormal rod electroretinogram” (CDSR). Methods Seven patients, aged 9 to 18 years at last visit, with characteristic full-field electroretinographic (ERG) features of CDSR were screened for mutations in the KCNV2 gene. All patients underwent detailed ophthalmological evaluation, which included distance and color vision testing, contrast sensitivity measurement, fundus photography, fundus auto-fluorescence (FAF) imaging, and spectral domain-optical coherence tomography (SD-OCT). Follow-up visits were available in six cases. Rod photoreceptor function was assessed using a bright white flash ERG protocol (240 cd·s/m2). Macular cone photoreceptor morphology was assessed from 2° by 2° zonal images obtained using adaptive optics scanning laser ophthalmoscopy (AOSLO) in six cases. Results Pathogenic mutations in KCNV2 were identified in all seven cases. Best corrected vision was 20/125 or worse in all cases at the latest visit (20/125–20/400). Vision loss was progressive in two cases. Color vision and contrast sensitivity was abnormal in all cases. Retinal exam revealed minimal pigment epithelial changes at the fovea in four cases. A peri- or parafoveal ring of hyperfluorescence was the most common FAF abnormality noted (five cases). The SD-OCT showed outer retinal abnormalities in all cases. The rod photoreceptor maximal response was reduced but rod sensitivity was normal. AOSLO showed markedly reduced cone density in all six patients tested. Conclusions Central vision parameters progressively worsen in CDSR. Structural retinal and lipofuscin accumulation abnormalities are commonly present. Macular cone photoreceptor mosaic is markedly disrupted early in the disease. PMID:23221069

  1. Possible Tuff Cones In Isidis Planitia, Mars

    NASA Astrophysics Data System (ADS)

    Seabrook, A. M.; Rothery, D. A.; Bridges, J. C.; Wright, I. P.

    The Beagle 2 lander of the ESA Mars Express mission will touch down on the martian surface in December 2003 to conduct a primarily exobiological mission. The landing site will be within Isidis Planitia, an 1100 km diameter impact basin. Isidis contains many sub-kilometre-sized cones. These can be found singly, in clusters, and in straight or arcuate chains extending many kilometres. In some areas of the basin these cones can occupy over 10% of the surface, with the most densely populated areas being in the older western half of the basin. There are few cones around the basin rim. There is also variation in the erosional state of the cones both across the basin, and within smaller areas, implying a range in time of formation for the cones. We currently favour a tuff cone origin as an explanation for these features. Tuff cones on Earth are rooted volcanic features formed at vents by the interaction between magma or magmatic heat and surface or near-surface water. Lava flows likely to be associated with at least some of the cones if they had a cinder cone (rooted eruptions at vents in a dry environment) origin are absent. This suggests the involvement of suffi- cient volatiles both to explosively fragment the erupting magma, and to cool the ejecta enough to prevent the formation of clastogenic flows. If our tuff cone interpretation is correct, this has implications for the presence, abundance and long-term persistence of sub-surface volatiles (water or carbon dioxide) on Mars. An understanding of the mechanism of formation of the Isidis cones will assist the characterisation of the basin in preparation for the landing of Beagle 2, by providing information about the history of volatiles and volcanism in the basin, and the processes that resulted in the surface we see today.

  2. USDC-based rapid penetrator of packed soil

    NASA Astrophysics Data System (ADS)

    Bao, X.; Bar-Cohen, Y.; Chang, Z.; Sherrit, S.; Badescu, M.; Du, S.; Song, T.; Peterson, T.

    2006-03-01

    Environment protection requires more testing and analysis tools. To detect buried chemical containers or other objects embedded in soil and avoid possible damage to them, a penetrator was developed for packed soil that requires low penetration force (the force needed to push rod probe into the soil). The design was based on the novel mechanism used by the ultrasonic/sonic driller/corer (USDC) that was developed jointly by scientists at the NDEAA lab at JPL and engineers at Cybersonics, Inc. [Bar-Cohen et al 2001, Bao et al 2003]. In the penetrator, a small free-flying mass is energized by a piezoelectric transducer and impacts a rod probe on its shoulder at frequencies of several hundred Hetz. The impacts help the probe to penetrate the packed soil with low pushing force. A large reduction of the penetration force was achieved. Preliminary tests show that the effects of the penetrator on plastic containers and other objectors are minimal. The details of the design of the prototype penetrator and the results of performance tests are presented.

  3. Evaluation of Microencapsulated Penetrant Inspection.

    DTIC Science & Technology

    1980-12-01

    AD-A9b 826 GENERAL ELECTRIC CO CINCINNATI OH AIRCRAFT ENGINE GROUP F/6 IA/2ADG EVALUATION OF MICROENCAPSULATED PENETRANT INSPECTION.(U) DEC 80 J M...4156 ADA096826 EVALUATION OF MICROENCAPSULATED PENETRANT INSPECTION i :I J.M. Portaz Aircraft Engine Group General Electric Company Cincinnati, Ohio... Microencapsulated Penetrant 5 7riJF-Iehica17 = Inspection p un May@84 -1 ---- --- ---- 19AMFGK657j7 7. AiJTHOR(s) nVCWRACT OR GRANT m 𔃻 " JO J.M./Portaz

  4. Radon penetration of concrete slab cracks, joints, pipe penetrations, and sealants.

    PubMed

    Nielson, K K; Rogers, V C; Holt, R B; Pugh, T D; Grondzik, W A; de Meijer, R J

    1997-10-01

    Radon movement through 12 test slabs with different cracks, pipe penetrations, cold joints, masonry blocks, sealants, and tensile stresses characterized the importance of these anomalous structural domains. Diffusive and advective radon transport were measured with steady-state air pressure differences controlled throughout the deltaP = 0 to 60 Pa range. Diffusion coefficients (deltaP = 0) initially averaged 6.5 x 10(-8) m2 s(-1) among nine slabs with only 8% standard deviation, but increased due to drying by 0.16% per day over a 2-y period to an average of 2.0 x 10(-7) m2 s(-1). An asphalt coating reduced diffusion sixfold but an acrylic surface sealant had no effect. Diffusion was 42 times higher in solid masonry blocks than in concrete and was not affected by small cracks. Advective transport (deltaP < or = 60 Pa) was negligible for the slabs (10(-16) m2 permeability), pipe penetrations, and caulked gaps, but was significant for cracks, disturbed pipe penetrations, cold joints, masonry blocks, and concrete under tensile stress. Crack areas calculated to be as small as 10(-7) m2 significantly increased radon advection. Algebraic expressions predict air velocity and effective crack width from enhanced radon transport and air pressures. Masonry blocks, open cracks, and slab cold joints enhance radon penetration but stressed slabs, undisturbed pipe penetrations, and sealed cracks may not.

  5. Heterologous ovum penetration by human spermatozoa.

    PubMed

    Tyler, J P; Pryor, J P; Collins, W P

    1981-11-01

    An evaluation of a method utilizing zona-free hamster ova to test the fertility of human spermatozoa has shown that (i) the induction of superovulation in immature animals provides the most convenient method of obtaining mature ova for study; (ii) motile spermatozoa are best prepared by the technique of layering; (iii) an 18 h incubation at 37 degrees C (which is associated with capacitation) in an atmosphere of air (pH of medium 8.2) is preferable to one of 5% CO2 (pH of medium 7.2); (iv) the incubation and insemination densities of spermatozoa should be greater than 1 X 10(6) and less than 10 X 10(6)/ml; (v) spermatozoa do not remain motile, or capable of binding to or penetrating ova, after about 30 h in culture; and (vi) intra- and inter-assay variations are acceptable. The spermatozoa from 15 healthy men of proven fertility and 15 subfertile patients with normal spermiograms were evaluated for their ability to bind to and penetrate zona-free hamster ova. Of the 476 ova inseminated with spermatozoa from the fertile men greater than 5 spermatozoa/ovum consistently bound to the vitelline membrane and 284 ova (59.7%) had swollen sperm heads to pronuclei (still with tails attached) in their ooplasm. The range of individual penetration rates was 23.5-88.9%. Of the 586 ova tested with spermatozoa from the infertile subjects only 11 (1.9%) showed any evidence of penetration (range of individual penetration rates 0-8.7%) and binding to the vitelline membrane was poor (0 or less than 5 spermatozoa/ovum). Spermatozoa from a further 9 infertile men who had abnormal spermiograms also gave poor penetration rates (4/300 ova, 1.3%). It is concluded that this bioassay has a useful role as an additional test to the classic spermiogram, but that its routine use is best reserved for selected cases of unexplained infertility.

  6. Panoramic cone beam computed tomography

    SciTech Connect

    Chang Jenghwa; Zhou Lili; Wang Song; Clifford Chao, K. S.

    2012-05-15

    Purpose: Cone-beam computed tomography (CBCT) is the main imaging tool for image-guided radiotherapy but its functionality is limited by a small imaging volume and restricted image position (imaged at the central instead of the treatment position for peripheral lesions to avoid collisions). In this paper, the authors present the concept of ''panoramic CBCT,'' which can image patients at the treatment position with an imaging volume as large as practically needed. Methods: In this novel panoramic CBCT technique, the target is scanned sequentially from multiple view angles. For each view angle, a half scan (180 deg. + {theta}{sub cone} where {theta}{sub cone} is the cone angle) is performed with the imaging panel positioned in any location along the beam path. The panoramic projection images of all views for the same gantry angle are then stitched together with the direct image stitching method (i.e., according to the reported imaging position) and full-fan, half-scan CBCT reconstruction is performed using the stitched projection images. To validate this imaging technique, the authors simulated cone-beam projection images of the Mathematical Cardiac Torso (MCAT) thorax phantom for three panoramic views. Gaps, repeated/missing columns, and different exposure levels were introduced between adjacent views to simulate imperfect image stitching due to uncertainties in imaging position or output fluctuation. A modified simultaneous algebraic reconstruction technique (modified SART) was developed to reconstruct CBCT images directly from the stitched projection images. As a gold standard, full-fan, full-scan (360 deg. gantry rotation) CBCT reconstructions were also performed using projection images of one imaging panel large enough to encompass the target. Contrast-to-noise ratio (CNR) and geometric distortion were evaluated to quantify the quality of reconstructed images. Monte Carlo simulations were performed to evaluate the effect of scattering on the image quality and

  7. Shock detachment process on cones in hypervelocity flows

    NASA Astrophysics Data System (ADS)

    Leyva, Ivett Alejandra

    1999-11-01

    The shock detachment process on cones in hypervelocity flows is one of the most sensitive flows to relaxation effects. The critical angle for shock detachment under frozen conditions can be very different from the critical angle under chemical and thermal equilibrium. The rate of increase of the detachment distance with cone angle is also affected by the relaxation rate. The purpose of this study is to explain the effects of nonequilibrium on the shock detachment distance and its growth rate on cones in hypervelocity flows. The study consists of an experimental and a computational program. The experimental part has been carried out at Caltech's hypervelocity reflected shock tunnel. Six free-stream conditions were chosen, using both N2 and CO2 as test gases. The experimental data obtained are holographic interferograms, surface temperature, and pressure measurements. The code employed for the numerical simulations is a Navier-Stokes solver that can account for thermal and chemical nonequilibrium in axisymmetric flows. The data obtained for the shock detachment distance confirms a previous theoretical model that predicts the detachment distance will grow more slowly for relaxing flows than for frozen or equilibrium flows. This difference is due to the behavior of the sonic line inside the shock layer. Different growth rates result when the detachment distance is controlled by the diameter of the cone (frozen and equilibrium cases) than when it is controlled by the relaxation length (nonequilibrium flows). The behavior of the detachment distance from the frozen to equilibrium limits for a given cone half-angle and free-stream condition has also been studied. It was confirmed that the ratio of the detachment distance to the cone diameter is constant in the two extremes and rapidly switches from one value to the other for cone diameters of about 2 cm to 16 cm. The experimental interferograms are also compared with numerical ones in terms of the detachment distance, the

  8. Functional significance of the taper of vertebrate cone photoreceptors

    PubMed Central

    Hárosi, Ferenc I.

    2012-01-01

    Vertebrate photoreceptors are commonly distinguished based on the shape of their outer segments: those of cones taper, whereas the ones from rods do not. The functional advantages of cone taper, a common occurrence in vertebrate retinas, remain elusive. In this study, we investigate this topic using theoretical analyses aimed at revealing structure–function relationships in photoreceptors. Geometrical optics combined with spectrophotometric and morphological data are used to support the analyses and to test predictions. Three functions are considered for correlations between taper and functionality. The first function proposes that outer segment taper serves to compensate for self-screening of the visual pigment contained within. The second function links outer segment taper to compensation for a signal-to-noise ratio decline along the longitudinal dimension. Both functions are supported by the data: real cones taper more than required for these compensatory roles. The third function relates outer segment taper to the optical properties of the inner compartment whereby the primary determinant is the inner segment’s ability to concentrate light via its ellipsoid. In support of this idea, the rod/cone ratios of primarily diurnal animals are predicted based on a principle of equal light flux gathering between photoreceptors. In addition, ellipsoid concentration factor, a measure of ellipsoid ability to concentrate light onto the outer segment, correlates positively with outer segment taper expressed as a ratio of characteristic lengths, where critical taper is the yardstick. Depending on a light-funneling property and the presence of focusing organelles such as oil droplets, cone outer segments can be reduced in size to various degrees. We conclude that outer segment taper is but one component of a miniaturization process that reduces metabolic costs while improving signal detection. Compromise solutions in the various retinas and retinal regions occur between

  9. Recoverin depletion accelerates cone photoresponse recovery

    PubMed Central

    Zang, Jingjing; Keim, Jennifer; Kastenhuber, Edda; Gesemann, Matthias; Neuhauss, Stephan C. F.

    2015-01-01

    The neuronal Ca2+-binding protein Recoverin has been shown to regulate phototransduction termination in mammalian rods. Here we identify four recoverin genes in the zebrafish genome, rcv1a, rcv1b, rcv2a and rcv2b, and investigate their role in modulating the cone phototransduction cascade. While Recoverin-1b is only found in the adult retina, the other Recoverins are expressed throughout development in all four cone types, except Recoverin-1a, which is expressed only in rods and UV cones. Applying a double flash electroretinogram (ERG) paradigm, downregulation of Recoverin-2a or 2b accelerates cone photoresponse recovery, albeit at different light intensities. Exclusive recording from UV cones via spectral ERG reveals that knockdown of Recoverin-1a alone has no effect, but Recoverin-1a/2a double-knockdowns showed an even shorter recovery time than Recoverin-2a-deficient larvae. We also showed that UV cone photoresponse kinetics depend on Recoverin-2a function via cone-specific kinase Grk7a. This is the first in vivo study demonstrating that cone opsin deactivation kinetics determine overall photoresponse shut off kinetics. PMID:26246494

  10. Cone penetrometer demonstration standard startup review checklist

    SciTech Connect

    KRIEG, S.A.

    1998-11-09

    Startup readiness for the Cone Penetrometer Demonstration in AX Tank Farm will be verified through the application of a Standard Startup Review Checklist. This is a listing of those items essential to demonstrating readiness to start the Cone Penetrometer Demonstration in AX Tank Farm.

  11. Morphology of pyroclastic cones and tectonics

    NASA Astrophysics Data System (ADS)

    Tibaldi, Alessandro

    1995-12-01

    The relationships between morphology and spatial distribution of 1315 Quaternary pyroclastic cones and coeval faulting of the volcanic substrate are analyzed in the following regions with different structural settings: Tepic Rift (Mexico), Ethiopian Rift, Mexican Volcanic Belt, Canary Archipelago, and Mount Etna. Field data and analog experiments of tephra cone emplacement and collapse enable the definition of a number of parameters which can be used to infer the geometry of the fracture feeding the magma to a pyroclastic cone. The strike of the feeding plane is directly related to: (1) the elongation of cone base and crater, (2) the location of depressions on the crater rim, and (3) the alignment of pyroclastic cones in relation to a given vent spacing. In addition, the strike and dip of faults affect the direction of cone breaching. These relationships are valid for volcanic substrate topographic surfaces with an inclination of less than 9° and are especially sensitive to fault escarpment and cone height, lava and cone density, and fault orientation with respect to the dip of the volcanic substrate topography. Relations 1 and 2 become more pronounced for regions undergoing extensional tectonics, where edifices also have a larger dimension. Whereas breaching in the direction of the fault dip is more widespread in regions under extension, breaching along the fault strike as well as the coincidence between fault strike and vent alignment are more frequent in regions with transcurrent or transtensional tectonics.

  12. Targeting gene expression to cones with human cone opsin promoters in recombinant AAV.

    PubMed

    Komáromy, A M; Alexander, J J; Cooper, A E; Chiodo, V A; Glushakova, L G; Acland, G M; Hauswirth, W W; Aguirre, G D

    2008-07-01

    Specific cone-directed therapy is of high priority in the treatment of human hereditary retinal diseases. However, not much information exists about the specific targeting of photoreceptor subclasses. Three versions of the human red cone opsin promoter (PR0.5, 3LCR-PR0.5 and PR2.1), and the human blue cone opsin promoter HB569, were evaluated for their specificity and robustness in targeting green fluorescent protein (GFP) gene expression to subclasses of cones in the canine retina when used in recombinant adeno-associated viral vectors of serotype 5. The vectors were administered by subretinal injection. The promoter PR2.1 led to most effective and specific expression of GFP in the long- and medium-wavelength-absorbing cones (L/M cones) of normal and diseased retinas. The PR0.5 promoter was not effective. Adding three copies of the 35-bp LCR in front of PR0.5 lead to weak GFP expression in L/M cones. The HB569 promoter was not specific, and GFP was expressed in a few L/M cones, some rods and the retinal pigment epithelium. These results suggest that L/M cones, the predominant class of cone photoreceptors in the retinas of dogs and most mammalian species can be successfully targeted using the human red cone opsin promoter.

  13. CTH analyses of steel rod penetration into aluminum and concrete targets with comparisons to experimental data

    SciTech Connect

    Kmetyk, L.N.; Yarrington, P.

    1994-10-01

    Calculational results are presented here for a class of intermediate-velocity penetration problems. The problems of interest involve penetration of moderate-strength target materials by high-strength projectiles. Two series of metal penetration experiments and a series of concrete slab perforation tests were simulated in this study. The computer code used for the calculations was the CTH code, which employs a recently-developed ``boundary layer`` algorithm for treating penetration problems such as these.

  14. RPE65 gene therapy slows cone loss in Rpe65-deficient dogs.

    PubMed

    Mowat, F M; Breuwer, A R; Bartoe, J T; Annear, M J; Zhang, Z; Smith, A J; Bainbridge, J W B; Petersen-Jones, S M; Ali, R R

    2013-05-01

    Recent clinical trials of retinal pigment epithelium gene (RPE65) supplementation therapy in Leber congenital amaurosis type 2 patients have demonstrated improvements in rod and cone function, but it may be some years before the effects of therapy on photoreceptor survival become apparent. The Rpe65-deficient dog is a very useful pre-clinical model in which to test efficacy of therapies, because the dog has a retina with a high degree of similarity to that of humans. In this study, we evaluated the effect of RPE65 gene therapy on photoreceptor survival in order to predict the potential benefit and limitations of therapy in patients. We examined the retinas of Rpe65-deficient dogs after RPE65 gene therapy to evaluate the preservation of rods and cone photoreceptor subtypes. We found that gene therapy preserves both rods and cones. While the moderate loss of rods in the Rpe65-deficient dog retina is slowed by gene therapy, S-cones are lost extensively and gene therapy can prevent that loss, although only within the treated area. Although LM-cones are not lost extensively, cone opsin mislocalization indicates that they are stressed, and this can be partially reversed by gene therapy. Our results suggest that gene therapy may be able to slow cone degeneration in patients if intervention is sufficiently early and also that it is probably important to treat the macula in order to preserve central function.

  15. Ground Penetrating Radar, Barrow, Alaska

    DOE Data Explorer

    John Peterson

    2015-03-06

    This is 500 MHz Ground Penetrating Radar collected along the AB Line in Intensive Site 1 beginning in October 2012 and collected along L2 in Intensive Site 0 beginning in September 2011. Both continue to the present.

  16. Investigations into Monochloramine Biofilm Penetration

    EPA Science Inventory

    Biofilm in drinking water systems is undesirable. Free chlorine and monochloramine are commonly used as secondary drinking water disinfectants, but monochloramine is perceived to penetrate biofilm better than free chlorine. However, this hypothesis remains unconfirmed by direct b...

  17. Mechanochemical regulation of growth cone motility

    PubMed Central

    Kerstein, Patrick C.; Nichol, Robert H.; Gomez, Timothy M.

    2015-01-01

    Neuronal growth cones are exquisite sensory-motor machines capable of transducing features contacted in their local extracellular environment into guided process extension during development. Extensive research has shown that chemical ligands activate cell surface receptors on growth cones leading to intracellular signals that direct cytoskeletal changes. However, the environment also provides mechanical support for growth cone adhesion and traction forces that stabilize leading edge protrusions. Interestingly, recent work suggests that both the mechanical properties of the environment and mechanical forces generated within growth cones influence axon guidance. In this review we discuss novel molecular mechanisms involved in growth cone force production and detection, and speculate how these processes may be necessary for the development of proper neuronal morphogenesis. PMID:26217175

  18. Unique characteristics of cones in Central Elysium Planitia, Mars

    NASA Astrophysics Data System (ADS)

    Noguchi, Rina; Kurita, Kei

    2015-06-01

    Martian magmatism within recent several hundreds of millions years is still controversial. Central Elysium Planitia (CEP) is suspected as a site of the latest magmatism on Mars, but hot debates have been caused as for the origin of this flat plain. Cones in CEP are expected to be a key to resolve this controversy. In previous works, there are 2 models proposed for the origin of CEP cones: volcanic rootless cone (e.g. Jaeger et al., 2007) and periglacial pingo (e.g. Burr et al., 2002; Page et al., 2009). In this study, we described detail morphology, distribution and size of CEP cones by using high-resolution images and topographic data. CEP cones are classified into 3 morphological types: Single Cone (SC), Double Cone (DC), and Lotus Fruit Cone (LC). DC has an inner cone in the summit crater of the outer cone, and LC has several inner cones in the summit crater of the outer cone. Several cones have moat structure around the edifice with peripheral rise. DCs and LCs are located in very flat areas of Athabasca Valles in the vicinity of Cerberus Fossae, while SCs distribute in the entire region of CEP. We compared CEP cones with terrestrial rootless cones and pingos in aerial photos. In Lake Myvatn, Iceland, there exist rootless cones which resemble DCs and LCs in CEP. Based on the similarities with terrestrial analogies, we concluded that the most feasible origin of CEP cones is rootless cones.

  19. Seismic-Reflection and Ground Penetrating Radar for Environmental Site Characterization

    SciTech Connect

    Steeples, Don W.; Plumb, Richard

    1999-06-01

    The goals of the project are: (1) To examine the complementary site-characterization capabilities of modern, three component shallow seismic reflection (SSR) techniques and ground-penetrating radar (GPR) methods at depths ranging from 2 to 8 m at an existing test site; (2) To demonstrate the usefulness of the two methods when used in concert to characterize, in three dimensions, the cone of depression of a pumping well that will serve as a proxy site for fluid-flow at an actual, polluted site; (3) To use the site as an outdoor mesoscale laboratory to validate existing three dimensional ground-penetrating radar and seismic-reflection computer models developed at the University of Kansas. To do this, seismic and GPR data are being collected along the same line(s) and within the same depth range. The principal investigators selected a site in central Kansas as a primary location, and although the site itself is not environmentally sensitive, the area offers attributes that are particularly useful for this research and allow the site to serve as a proxy for areas that are contaminated. As part of an effort to evaluate the strengths of each method, the seismic and GPR surveys are repeated on a seasonal basis to establish how the complementary information obtained varies over time. Because the water table fluctuates seasonally at this site, variations in the two types of data over time also can be observed. Such noninvasive, in-situ methods of identifying and characterizing the hydrologic flow regimes at contaminated sites support the prospect of developing effective, cost conscious cleanup strategies in the near future.

  20. Shock detachment process on cones in hypervelocity flows

    NASA Astrophysics Data System (ADS)

    Leyva, Ivett A.

    1999-11-01

    The shock detachment process on cones in hypervelocity flows is one of the most sensitive flows to relaxation effects. The critical angle for shock detachment under frozen conditions can be very different from the critical angle under chemical and thermal equilibrium. The rate of increase of the detachment distance with cone angle is also affected by the relaxation rate. The purpose of this study is to explain the effects of nonequilibrium on the shock detachment distance and its growth rate on cones in hypervelocity flows. The study consists of an experimental and a computational program. The experimental part has been carried out at Caltech's hypervelocity reflected shock tunnel (T5). Six different free-stream conditions have been chosen, four using N2 as the test gas and two using CO2. About 170 shots were performed on 24 cones. The cones range in diameter from 2 cm to 16 cm with half-angles varying from 55° to 75°. The experimental data obtained are holographic interferograms of every shot, and surface temperature and pressure measurements for the bigger cones. Extensive numerical simulations were made for the N2 flows and some were also made for the CO2 flows. The code employed is a Navier-Stokes solver that can account for thermal and chemical nonequilibrium in axisymmetric flows. The experimental and computational data obtained for the shock detachment distance confirms a previous theoretical model that predicts the detachment distance will grow more slowly for relaxing flows than for frozen or equilibrium flows. This difference is explained in terms of the behavior of the sonic line inside the shock layer. Different growth rates result when the detachment distance is controlled by the diameter of the cone (frozen and equilibrium cases) than when it is controlled by the extent of the relaxation zone inside the shock layer (nonequilibrium flows). The experimental data are also complemented with computational data to observe the behavior of the detachment

  1. Toroidal modeling of penetration of the resonant magnetic perturbation field

    SciTech Connect

    Liu Yueqiang; Kirk, A.

    2013-04-15

    A toroidal, quasi-linear model is proposed to study the penetration dynamics of the resonant magnetic perturbation (RMP) field into the plasma. The model couples the linear, fluid plasma response to a toroidal momentum balance equation, which includes torques induced by both fluid electromagnetic force and by (kinetic) neoclassical toroidal viscous (NTV) force. The numerical results for a test toroidal equilibrium quantify the effects of various physical parameters on the field penetration and on the plasma rotation braking. The neoclassical toroidal viscous torque plays a dominant role in certain region of the plasma, for the RMP penetration problem considered in this work.

  2. Toroidal modeling of penetration of the resonant magnetic perturbation field

    NASA Astrophysics Data System (ADS)

    Liu, Yueqiang; Kirk, A.; Sun, Y.

    2013-04-01

    A toroidal, quasi-linear model is proposed to study the penetration dynamics of the resonant magnetic perturbation (RMP) field into the plasma. The model couples the linear, fluid plasma response to a toroidal momentum balance equation, which includes torques induced by both fluid electromagnetic force and by (kinetic) neoclassical toroidal viscous (NTV) force. The numerical results for a test toroidal equilibrium quantify the effects of various physical parameters on the field penetration and on the plasma rotation braking. The neoclassical toroidal viscous torque plays a dominant role in certain region of the plasma, for the RMP penetration problem considered in this work.

  3. Penetration and lateral diffusion characteristics of polycrystalline graphene barriers.

    PubMed

    Yoon, Taeshik; Mun, Jeong Hun; Cho, Byung Jin; Kim, Taek-Soo

    2014-01-07

    We report penetration and lateral diffusion behavior of environmental molecules on synthesized polycrystalline graphene. Penetration occurs through graphene grain boundaries resulting in local oxidation. However, when the penetrated molecules diffuse laterally, the oxidation region will expand. Therefore, we measured the lateral diffusion rate along the graphene-copper interface for the first time by the environment-assisted crack growth test. It is clearly shown that the lateral diffusion is suppressed due to the high van der Waals interaction. Finally, we employed bilayer graphene for a perfect diffusion barrier facilitated by decreased defect density and increased lateral diffusion path.

  4. Evolutionary transformation of rod photoreceptors in the all-cone retina of a diurnal garter snake.

    PubMed

    Schott, Ryan K; Müller, Johannes; Yang, Clement G Y; Bhattacharyya, Nihar; Chan, Natalie; Xu, Mengshu; Morrow, James M; Ghenu, Ana-Hermina; Loew, Ellis R; Tropepe, Vincent; Chang, Belinda S W

    2016-01-12

    Vertebrate retinas are generally composed of rod (dim-light) and cone (bright-light) photoreceptors with distinct morphologies that evolved as adaptations to nocturnal/crepuscular and diurnal light environments. Over 70 years ago, the "transmutation" theory was proposed to explain some of the rare exceptions in which a photoreceptor type is missing, suggesting that photoreceptors could evolutionarily transition between cell types. Although studies have shown support for this theory in nocturnal geckos, the origins of all-cone retinas, such as those found in diurnal colubrid snakes, remain a mystery. Here we investigate the evolutionary fate of the rods in a diurnal garter snake and test two competing hypotheses: (i) that the rods, and their corresponding molecular machinery, were lost or (ii) that the rods were evolutionarily modified to resemble, and function, as cones. Using multiple approaches, we find evidence for a functional and unusually blue-shifted rhodopsin that is expressed in small single "cones." Moreover, these cones express rod transducin and have rod ultrastructural features, providing strong support for the hypothesis that they are not true cones, as previously thought, but rather are modified rods. Several intriguing features of garter snake rhodopsin are suggestive of a more cone-like function. We propose that these cone-like rods may have evolved to regain spectral sensitivity and chromatic discrimination as a result of ancestral losses of middle-wavelength cone opsins in early snake evolution. This study illustrates how sensory evolution can be shaped not only by environmental constraints but also by historical contingency in forming new cell types with convergent functionality.

  5. Evolutionary transformation of rod photoreceptors in the all-cone retina of a diurnal garter snake

    PubMed Central

    Schott, Ryan K.; Müller, Johannes; Yang, Clement G. Y.; Bhattacharyya, Nihar; Chan, Natalie; Xu, Mengshu; Morrow, James M.; Ghenu, Ana-Hermina; Loew, Ellis R.; Tropepe, Vincent; Chang, Belinda S. W.

    2016-01-01

    Vertebrate retinas are generally composed of rod (dim-light) and cone (bright-light) photoreceptors with distinct morphologies that evolved as adaptations to nocturnal/crepuscular and diurnal light environments. Over 70 years ago, the “transmutation” theory was proposed to explain some of the rare exceptions in which a photoreceptor type is missing, suggesting that photoreceptors could evolutionarily transition between cell types. Although studies have shown support for this theory in nocturnal geckos, the origins of all-cone retinas, such as those found in diurnal colubrid snakes, remain a mystery. Here we investigate the evolutionary fate of the rods in a diurnal garter snake and test two competing hypotheses: (i) that the rods, and their corresponding molecular machinery, were lost or (ii) that the rods were evolutionarily modified to resemble, and function, as cones. Using multiple approaches, we find evidence for a functional and unusually blue-shifted rhodopsin that is expressed in small single “cones.” Moreover, these cones express rod transducin and have rod ultrastructural features, providing strong support for the hypothesis that they are not true cones, as previously thought, but rather are modified rods. Several intriguing features of garter snake rhodopsin are suggestive of a more cone-like function. We propose that these cone-like rods may have evolved to regain spectral sensitivity and chromatic discrimination as a result of ancestral losses of middle-wavelength cone opsins in early snake evolution. This study illustrates how sensory evolution can be shaped not only by environmental constraints but also by historical contingency in forming new cell types with convergent functionality. PMID:26715746

  6. Space station integrated wall design and penetration damage control

    NASA Technical Reports Server (NTRS)

    Coronado, A. R.; Gibbins, M. N.; Wright, M. A.; Stern, P. H.

    1987-01-01

    A methodology was developed to allow a designer to optimize the pressure wall, insulation, and meteoroid/debris shield system of a manned spacecraft for a given spacecraft configuration and threat environment. The threat environment consists of meteoroids and orbital debris, as specified for an arbitrary orbit and expected lifetime. An overall probability of no penetration is calculated, as well as contours of equal threat that take into account spacecraft geometry and orientation. Techniques, tools, and procedures for repairing an impacted and penetrated pressure wall were developed and tested. These techniques are applied from the spacecraft interior and account for the possibility of performing the repair in a vacuum. Hypervelocity impact testing was conducted to: (1) develop and refine appropriate penetration functions, and (2) determine the internal effects of a penetration on personnel and equipment.

  7. Soil Penetration by Earthworms and Plant Roots—Mechanical Energetics of Bioturbation of Compacted Soils

    PubMed Central

    2015-01-01

    We quantify mechanical processes common to soil penetration by earthworms and growing plant roots, including the energetic requirements for soil plastic displacement. The basic mechanical model considers cavity expansion into a plastic wet soil involving wedging by root tips or earthworms via cone-like penetration followed by cavity expansion due to pressurized earthworm hydroskeleton or root radial growth. The mechanical stresses and resulting soil strains determine the mechanical energy required for bioturbation under different soil hydro-mechanical conditions for a realistic range of root/earthworm geometries. Modeling results suggest that higher soil water content and reduced clay content reduce the strain energy required for soil penetration. The critical earthworm or root pressure increases with increased diameter of root or earthworm, however, results are insensitive to the cone apex (shape of the tip). The invested mechanical energy per unit length increase with increasing earthworm and plant root diameters, whereas mechanical energy per unit of displaced soil volume decreases with larger diameters. The study provides a quantitative framework for estimating energy requirements for soil penetration work done by earthworms and plant roots, and delineates intrinsic and external mechanical limits for bioturbation processes. Estimated energy requirements for earthworm biopore networks are linked to consumption of soil organic matter and suggest that earthworm populations are likely to consume a significant fraction of ecosystem net primary production to sustain their subterranean activities. PMID:26087130

  8. Soil Penetration by Earthworms and Plant Roots--Mechanical Energetics of Bioturbation of Compacted Soils.

    PubMed

    Ruiz, Siul; Or, Dani; Schymanski, Stanislaus J

    2015-01-01

    We quantify mechanical processes common to soil penetration by earthworms and growing plant roots, including the energetic requirements for soil plastic displacement. The basic mechanical model considers cavity expansion into a plastic wet soil involving wedging by root tips or earthworms via cone-like penetration followed by cavity expansion due to pressurized earthworm hydroskeleton or root radial growth. The mechanical stresses and resulting soil strains determine the mechanical energy required for bioturbation under different soil hydro-mechanical conditions for a realistic range of root/earthworm geometries. Modeling results suggest that higher soil water content and reduced clay content reduce the strain energy required for soil penetration. The critical earthworm or root pressure increases with increased diameter of root or earthworm, however, results are insensitive to the cone apex (shape of the tip). The invested mechanical energy per unit length increase with increasing earthworm and plant root diameters, whereas mechanical energy per unit of displaced soil volume decreases with larger diameters. The study provides a quantitative framework for estimating energy requirements for soil penetration work done by earthworms and plant roots, and delineates intrinsic and external mechanical limits for bioturbation processes. Estimated energy requirements for earthworm biopore networks are linked to consumption of soil organic matter and suggest that earthworm populations are likely to consume a significant fraction of ecosystem net primary production to sustain their subterranean activities.

  9. An evaluation of the utility of four in situ test methods for transmission line foundation design

    SciTech Connect

    Mullen, W.G. Jr.

    1991-01-01

    This research examines four existing in-situ soil strength testing methods; standard penetration test (SPT), the cone penetrometer (CPT), the flat plate dilatometer (DMT), and the pressuremeter (PMT). Soils data were collected at eight separate sites using each of the devices. The test sites were chosen to mirror soil conditions encountered within the service territory of Virginia Power, the project sponsor. A total of 19 standard soil borings, 30 cone penetrometer soundings, 26 dilatometer soundings, and 33 pressuremeter tests were undertaken in residual, alluvial and marine clay soil conditions. The testing program was conducted with five areas of concern: (1) comparison of the penetration/stiffness data from the four tests, (2) comparison of values of undrained shear strength and angle of internal friction developed from each of the test methods, (3) determination if pressuremeter data can be correlated to and thereby developed from one of the more rapid tests, (4) comparison of indirect soil type identifications from the standard borings, (5) development of information on the relative effort required for each test. Comparison of the penetration resistance stiffness data produced useful correlations among the CPT and DMT, with the SPT data yielding more erratic results. Shear strength data was most consistent for the marine clay sites, while the CPT and DMT returned useful friction angle data in the alluvial sands. PMT data correlated well to both the CPT and DMT test results. Correlation of PMT results to the SPT was more erratic. Indirect soil identification from the CPT and DMT was fully adequate for transmission line foundation design purposes, and finally, useful comparative data on the relative testing time required for the four in-situ tests was developed.

  10. The role of short-wavelength sensitive cones and chromatic aberration in the response to stationary and step accommodation stimuli.

    PubMed

    Rucker, Frances J; Kruger, Philip B

    2004-01-01

    The aim of the experiment was to test for a contribution from short-wavelength sensitive cones to the static and step accommodation response, to compare responses from short and long- plus middle-wavelength sensitive cone types, and to examine the contribution of a signal from longitudinal chromatic aberration to the accommodation response. Accommodation was monitored continuously (eight subjects) to a square-wave grating (2.2 c/d; 0.57 contrast) in a Badal optometer. The grating stepped (1.00 D) randomly towards or away from the eye from a starting position of 2.00 D. Five illumination conditions were used to isolate cone responses, and combine them with or without longitudinal chromatic aberration. Accuracy of the response before the step, step amplitude, latencies and time-constants, were compared between conditions using single factor ANOVA and t-test comparisons. Both S-cones and LM-cones mediated static and step accommodation responses. S-cone contrast drives "static" accommodation for near, but the S-cone response is too slow to influence step dynamics when LM-cones participate.

  11. The Cone-specific Visual Cycle

    PubMed Central

    Wang, Jin-Shan; Kefalov, Vladimir J

    2010-01-01

    Cone photoreceptors mediate our daytime vision and function under bright and rapidly-changing light conditions. As their visual pigment is destroyed in the process of photoactivation, the continuous function of cones imposes the need for rapid recycling of their chromophore and regeneration of their pigment. The canonical retinoid visual cycle through the retinal pigment epithelium cells recycles chromophore and supplies it to both rods and cones. However, shortcomings of this pathway, including its slow rate and competition with rods for chromophore, have led to the suggestion that cones might use a separate mechanism for recycling of chromophore. In the past four decades biochemical studies have identified enzymatic activities consistent with recycling chromophore in the retinas of cone-dominant animals, such as chicken and ground squirrel. These studies have led to the hypothesis of a cone-specific retina visual cycle. The physiological relevance of these studies was controversial for a long time and evidence for the function of this visual cycle emerged only in very recent studies and will be the focus of this review. The retina visual cycle supplies chromophore and promotes pigment regeneration only in cones but not in rods. This pathway is independent of the pigment epithelium and instead involves the Müller cells in the retina, where chromophore is recycled and supplied selectively to cones. The rapid supply of chromophore through the retina visual cycle is critical for extending the dynamic range of cones to bright light and for their rapid dark adaptation following exposure to light. The importance of the retina visual cycle is emphasized also by its preservation through evolution as its function has now been demonstrated in species ranging from salamander to zebrafish, mouse, primate, and human. PMID:21111842

  12. Effectiveness of four chemical solutions in eliminating Bacillus subtilis spores on gutta-percha cones.

    PubMed

    Siqueira, J F; da Silva, C H; Cerqueira M das, D; Lopes, H P; de Uzeda, M

    1998-06-01

    Gutta-percha cones should be free of pathogenic micro-organisms before being used for root canal filling. This study was carried out to evaluate the effectiveness of four chemical agents in eliminating Bacillus subtilis spores from gutta-percha cones. The solutions tested were 5.25% sodium hypochlorite, 2% glutaraldehyde, 2% chlorhexidine digluconate, and 70% ethyl alcohol. The gutta-percha cones coated with spores were placed into contact with the chemical agents for 1, 3, 5 and 10 min. The results showed that 5.25% sodium hypochlorite was effective in destroying the spores after 1 min of contact. Glutaraldehyde, chlorhexidine and ethyl alcohol did not decontaminate the gutta-percha cones even after 10 min of contact.

  13. Feasibility study for the Cryogenic Orbital Nitrogen Experiment (CONE)

    NASA Technical Reports Server (NTRS)

    Bell, R. S.; Crouch, M. A.; Hanna, G. J.; Cady, E. C.; Meserole, J. S.

    1991-01-01

    An improved understanding of low gravity subcritical cryogenic fluid behavior is critical for the continued development of space based systems. Although early experimental programs provided some fundamental understanding of zero gravity cryogenic fluid behavior, more extensive flight data are required to design space based cryogenic liquid storage and transfer systems with confidence. As NASA's mission concepts evolve, the demand for optimized in-space cryogenic systems is increasing. Cryogenic Orbital Nitrogen Experiment (CONE) is an attached shuttle payload experiment designed to address major technological issues associated with on-orbit storage and supply of cryogenic liquids. During its 7 day mission, CONE will conduct experiments and technology demonstrations in active and passive pressure control, stratification and mixing, liquid delivery and expulsion efficiency, and pressurant bottle recharge. These experiments, conducted with liquid nitrogen as the test fluid, will substantially extend the existing low gravity fluid data base and will provide future system designers with vital performance data from an orbital environment.

  14. Active sample acquisition system for micro-penetrators

    NASA Astrophysics Data System (ADS)

    Voorhees, Chris; Potsaid, Benjamin

    1998-05-01

    This paper summarizes the design and development of a sub-surface sample acquisition system for use in micro-penetrators. The system was developed for flight use under NASA's New Millennium Program, Deep Space 2 project. The system goal is to acquire approximately 100 mg of Martian sub-surface soil and return it to the inside of the micro-penetrator for analysis to determine the presence of water. Various passive and active sampling techniques that were tested during the development cycle are described. After significant testing, a side bore drill mechanism was chosen to be developed for use in the flight penetrators. The design, development, and testing of mechanism element are outlined, with particular emphasis placed on actuator development, drill stem design, impact testing, and mechanism testing in various soil types. The other system elements, a pyrotechnically actuated door mechanism to seal the sample and an impact restraint mechanism, are also described.

  15. Static strain and vibration characteristics of a metal semimonocoque helicopter tail cone of moderate size

    NASA Technical Reports Server (NTRS)

    Bielawa, Richard L.; Hefner, Rachel E.; Castagna, Andre

    1991-01-01

    The results are presented of an analytic and experimental research program involving a Sikorsky S-55 helicopter tail cone directed ultimately to the improved structural analysis of airframe substructures typical of moderate sized helicopters of metal semimonocoque construction. Experimental static strain and dynamic shake-testing measurements are presented. Correlation studies of each of these tests with a PC-based finite element analysis (COSMOS/M) are described. The tests included static loadings at the end of the tail cone supported in the cantilever configuration as well as vibrational shake-testing in both the cantilever and free-free configurations.

  16. Investigation of flow pattern downstream of spiral grooved runner cone in pump-turbine

    NASA Astrophysics Data System (ADS)

    Sano, T.; Maekawa, M.; Okamoto, N.; Yano, H.; Miyagawa, K.

    2012-11-01

    High amplitude of pressure fluctuation is observed in a draft tube of a hydraulic turbine and a pump-turbine, for the case of partial load operation. Several methods had been reported to mitigate the amplitude so far, such as, air or water injection to the draft tube, fins on the draft tube surface, or runner replacement with optimized velocity profile at runner exit. However, several problems for each method can be considered, such as, negative influence on efficiency, high cost, technical difficulties for installation, and so on. To solve these problems and satisfy the demand for mitigating the amplitude of pressure fluctuation simultaneously, a new runner cone with spiral grooves on the surface was developed. It was developed with unsteady draft tube calculation based on Design of Experiment (DOE) method, and the effect was confirmed by model tests. Finally, developed runner cone was installed to the prototype pump turbine, and predicted performance was confirmed by on-site tests. However, the reason why the grooved runner cone can mitigate the amplitude of pressure fluctuation in draft tube was not clarified. Therefore, numerical investigation focusing around runner cone was carried out. As a result, it was clarified that the velocity profile at runner outlet was modified by the grooved runner cone, such as, reverse flow downstream of runner cone and tangential velocity was reduced. It means the shear stress between main stream and dead water core region was weakened, therefore, it can be estimated that the amplitude of draft pressure fluctuation was reduced.

  17. Cell-penetrating peptides transport therapeutics into cells.

    PubMed

    Ramsey, Joshua D; Flynn, Nicholas H

    2015-10-01

    Nearly 30years ago, certain small, relatively nontoxic peptides were discovered to be capable of traversing the cell membrane. These cell-penetrating peptides, as they are now called, have been shown to not only be capable of crossing the cell membrane themselves but can also carry many different therapeutic agents into cells, including small molecules, plasmid DNA, siRNA, therapeutic proteins, viruses, imaging agents, and other various nanoparticles. Many cell-penetrating peptides have been derived from natural proteins, but several other cell-penetrating peptides have been developed that are either chimeric or completely synthetic. How cell-penetrating peptides are internalized into cells has been a topic of debate, with some peptides seemingly entering cells through an endocytic mechanism and others by directly penetrating the cell membrane. Although the entry mechanism is still not entirely understood, it seems to be dependent on the peptide type, the peptide concentration, the cargo the peptide transports, and the cell type tested. With new intracellular disease targets being discovered, cell-penetrating peptides offer an exciting approach for delivering drugs to these intracellular targets. There are hundreds of cell-penetrating peptides being studied for drug delivery, and ongoing studies are demonstrating their success both in vitro and in vivo.

  18. Ballistic penetration response of intermetallic matrix composites

    SciTech Connect

    Kumar, K.S.; DiPietro, M.S. )

    1995-03-01

    Titanium aluminides and their composites exhibit about the same density as alumina, are tougher and can be produced by conventional casting and powder metallurgy techniques; further, they can be ground and machined more easily than alumina and lend themselves to better microstructural manipulation via heat treatments. Graded composite tiles with a high refractory reinforcement content on the outside and a lower amount on the inside may provide the desired abrasion resistance and toughness to effectively stop an incoming projectile. Likewise, alternating layers of hard and soft materials (e.g. Ti foils and TiAl) suitably graded in their spacings can serve as an effective armor tile. Testing of these materials gave the following conclusions: (1) Titanium aluminide composites are comparable to alumina in ballistic penetration resistance (for BS-41 and M-61 AP threats, and from the work of Chin and Woolsey, to long-rod penetrators) with perhaps improved resistance to shattering. (2) Incorporation of a residual compressive stress in the titanium aluminide composite tile significantly improved its penetration resistance. This concept could be utilized to decrease the required minimum tile thickness and hence, overall system weight.

  19. Composition and Biological Activity of Picea pungens and Picea orientalis Seed and Cone Essential Oils.

    PubMed

    Wajs-Bonikowska, Anna; Szoka, Łukasz; Karna, Ewa; Wiktorowska-Owczarek, Anna; Sienkiewicz, Monika

    2017-03-01

    The increasing consumption of natural products lead us to discover and study new plant materials, such as conifer seeds and cones, which could be easily available from the forest industry as a waste material, for their potential uses. The chemical composition of the essential oils of Picea pungens and Picea orientalis was fully characterized by GC and GC/MS methods. Seed and cone oils of both tree species were composed mainly of monoterpene hydrocarbons, among which limonene, α- and β-pinene were the major, but in different proportions in the examined conifer essential oils. The levorotary form of chiral monoterpene molecules was predominant over the dextrorotary form. The composition of oils from P. pungens seeds and cones was similar, while the hydrodistilled oils of P. orientalis seeds and cones differed from each other, mainly by a higher amount of oxygenated derivatives of monoterpenes and by other higher molar mass terpenes in seed oil. The essential oils showed mild antimicrobial action, however P. orientalis cone oil exhibited stronger antimicrobial properties against tested bacterial species than those of P. pungens. Effects of the tested cone essential oils on human skin fibroblasts and microvascular endothelial cells (HMEC-1) were similar: in a concentration of 0 - 0.075 μl/ml the oils were rather safe for human skin fibroblasts and 0 - 0.005 μl/ml for HMEC-1 cells. IC50 value of Picea pungens oils was 0.115 μl/ml, while that of Picea orientalis was 0.105 μl/ml. The value of IC50 of both oils were 0.035 μl/ml for HMEC-1 cells. The strongest effect on cell viability had the oil from Picea orientalis cones, while on DNA synthesis the oil from Picea pungens cones.

  20. Effectiveness of 2% peracetic acid for the disinfection of gutta-percha cones.

    PubMed

    Salvia, Ana Carolina Rodrigues Danzi; Teodoro, Guilherme Rodrigues; Balducci, Ivan; Koga-Ito, Cristiane Yumi; Oliveira, Simone Helena Gonçalves de

    2011-01-01

    The aim of this study was to evaluate the effectiveness of 2% peracetic acid for the disinfection of gutta-percha cones contaminated in vitro with Escherichia coli, Staphylococcus aureus, Streptococcus mutans, Candida albicans and Bacillus subtilus (in spore form). Two hundred and twenty-five gutta-percha cones were contaminated with standardized suspensions of each microorganism and incubated at 37°C for 24 h. The cones were divided into 10 experimental groups (n = 15), according to the microorganism tested and disinfection testing times. The disinfection procedure consisted of immersing each cone in a plastic tube containing the substance. The specimens remained in contact with the substance for 1 or 2.5 minutes. Afterwards, each cone was transferred to a 10% sodium thiosulphate solution (Na(2)S(2)O(3)) to neutralize the disinfectant. Microbial biofilms adhering to the cones were dispersed by agitation. Aliquots of 0.1 ml of the suspensions obtained were plated on Sabouraud dextrose agar, or brain and heart infusion agar, and incubated at 37°C for 24 h. The results were expressed in colony forming units (CFU/ml) and the data were submitted to the Wilcoxon Signed Rank Test (level of significance at 0.05). A significant reduction was observed, after 1 minute of exposure, in the test solution for C. albicans (p = 0.0190), S. aureus (p = 0.0001), S. mutans (p = 0.0001), B. subtilis (p = 0.0001), and E. coli (p = 0.0001). After 2.5 minutes of exposure, 100% of the microbial inocula were eliminated. It was concluded that the 2% peracetic acid solution was effective against the biofilms of the tested microorganisms on gutta-percha cones at 1 minute of exposure.

  1. Verification of RSRM Nozzle Thermal Models With ETM-3 Aft Exit Cone In-depth Temperature Measurements

    NASA Technical Reports Server (NTRS)

    Maw, Joel F.; Lui, Robbie C.; Totman, Peter D.

    2004-01-01

    One of the goals of the Engineering Test Motor (ETM-3) static test was to verify analytical models through the use of instrumentation that provide real-time transient temperature response of ablating phenolic liners. Accurate measurement of in-depth temperature is critical for validating the analytical models and assessing design safety margins for nozzle insulation materials. Recent developments of in-depth thermocouple plugs have been made to more accurately measure temperature response of nozzle Liners. Thermocouple plugs were installed at two axial stations (four plugs circumferentially at each station) near the end of the ETM-3 nozzle aft exit cone to gather temperature histories during and after motor operation. The thermocouple plugs were placed at depths that bounded the reusable solid rocket motor nominal measured char depth in order to portray the carbon phenolic temperature response during the charring process. The data were used to verify the analytical models during motor operation and to better define char penetration during heat soak after motor burn out.

  2. Mars surface penetrator: System description

    NASA Technical Reports Server (NTRS)

    Manning, L. A. (Editor)

    1977-01-01

    A point design of a penetrator system for a Mars mission is described. A strawman payload which is to conduct measurements of geophysical and meteorological parameters is included in the design. The subsystems used in the point design are delineated in terms of power, mass, volume, data, and functional modes. The prospects for survival of the rigors of emplacement are described. Data handling and communications plans are presented to allow consideration of the requirements placed by the penetrator on the orbiter and ground operations. The point design is technically feasible and the payload selection scientifically desirable.

  3. Fluconazole Penetration into the Pancreas

    PubMed Central

    Shrikhande, Shailesh; Friess, Helmut; Issenegger, Claudia; Martignoni, Marcus E.; Yong, Huang; Gloor, Beat; Yeates, Rodney; Kleeff, Jörg; Büchler, Markus W.

    2000-01-01

    Because of antibiotic prophylaxis for necrotizing pancreatitis, the frequency of fungal superinfection in patients with pancreatic necrosis is increasing. In this study we analyzed the penetration of fluconazole into the human pancreas and in experimental acute pancreatitis. In human pancreatic tissues, the mean fluconazole concentration was 8.19 ± 3.38 μg/g (96% of the corresponding concentration in serum). In experimental edematous and necrotizing pancreatitis, 88 and 91% of the serum fluconazole concentration was found in the pancreas. These data show that fluconazole penetration into the pancreas is sufficient to prevent and/or treat fungal contamination in patients with pancreatic necrosis. PMID:10952621

  4. Cone Quasi-Concave Multi-Objective Programming Theory and Dominance Cone Constructions.

    DTIC Science & Technology

    1988-08-01

    4 Cone Quasi-Concave Multi-Objective Prog ramm in(I Theory and Dominance Cone Constructions by A. Chames Z. M. Huang J. J. Rousseau 0. B. Sun 0. L...Report 606 Cone Quasi-Concave Multi-Objective Programming: Theory and Dominance Cone Constructions by A. Chames Z. M. Huang J. J. Rousseau D. B. Sun...permitted for any purpose of the U.S. Govemement. Tr% C CENTER FOR CYBERNETIC STUDIES cV- A. Chames , Director V 3 D 1 College of Business Administration

  5. Homologies among Coniferophyte cones: further observations

    NASA Astrophysics Data System (ADS)

    Grauvogel-Stamm, Léa; Galtier, Jean

    1998-04-01

    A reinvestigation of the Triassic conifer pollen cone of Darneya shows evidence that clusters of pollen sacs are attached (adnate), at regular intervals, to the upper side of the stalk and that the distribution of stomata is restricted to the apical part of the abaxial side of the peltate scale. These features and others, such as the commissure visible on the stalk and the scale, suggest a dual nature of the male scale complex of Darneya which therefore is interpreted as an abaxial bract fused with an adaxial fertile shoot bearing several clusters of pollen sacs. This conifer pollen cone is thus considered as a compound strobilus (inflorescence) homologous with the female cone of the conifers and therefore with the cones, both male and female, of the cordaites.

  6. A comparison of observed and analytically derived remote sensing penetration depths for turbid water

    NASA Technical Reports Server (NTRS)

    Morris, W. D.; Usry, J. W.; Witte, W. G.; Whitlock, C. H.; Guraus, E. A.

    1981-01-01

    The depth to which sunlight will penetrate in turbid waters was investigated. The tests were conducted in water with a single scattering albedo range, and over a range of solar elevation angles. Two different techniques were used to determine the depth of light penetration. It showed little change in the depth of sunlight penetration with changing solar elevation angle. A comparison of the penetration depths indicates that the best agreement between the two methods was achieved when the quasisingle scattering relationship was not corrected for solar angle. It is concluded that sunlight penetration is dependent on inherent water properties only.

  7. Exploring the topographic evolution of cinder cones

    NASA Astrophysics Data System (ADS)

    Arrowsmith, R.; Zibart, S.; Gleeman, E.; Alfano, F.; Clarke, A. B.; De'Michieli Vitturi, M.; Dekko, R.

    2013-12-01

    The simple original form and monogenetic character of cinder cones make them interesting targets for the study of landscape evolution. Topographic metrics such as cone height-width ratios and histograms of topographic slope yield useful and portable characterizations of cinder cone relative ages. We explored the topographic evolution of cinder cones by simulating surface processes using numerical and physical experimentation approaches and by collecting high resolution topography over exemplary elements of the San Francisco Volcanic field in northern Arizona. We identified a clear distinction in cone form development between those composed of transport-limited cinder only and those with a capping hard agglutinated rim. We employed a fully 2 dimensional numerical implementation of non linear diffusion with spatially variable transport rates. The agglutinate was idealized as an annulus of diminished transport rate. In the laboratory, we used a simple erosion model consisting of fine mist over a cone of fine sand. The agglutinate was represented with a spray adhesive cap. Non-agglutinated cones show a steady decrease in height and increase in width over time, resulting in a lower height-to-width ratios and greater rounding of profiles than agglutinated cones. The presence of an agglutinate top lessens the degree of rounding, producing a concave profile with a resistant 'neck' as the cone flank erodes, in contrast with non-agglutinated cones which develop into convex-concave profiles. The resistant agglutinate protects itself and the material directly underneath it from erosion; this material stays in place while the sediments around it are transported downslope. The slope distributions start out as bimodal: flat and angle of repose. In the non-agglutinated case, the rounding of the cone and broadening of the base produces a more continuous slope distribution with overall progressive slope decrease from the angle of repose and slope increase from the flat base. The

  8. DEFORMATION OF SCORIA CONE BY CONDUIT PRESSURIZATION

    SciTech Connect

    E.S. Gaffney; B. Damjanac; D. Krier; G. Valentine

    2005-08-26

    A simplified mechanical model is used to simulate the deformation of a scoria cone due to pressurization of magma in a feeder conduit. The scoria cone is modeled as consisting of a cone of stabilized scoria with an axial region of loose scoria (height h{sub 1}), all overlying a vertically oriented cylindrical conduit intruded into rhyolite tuff country rock. For our analyses, the conduit is filled with basalt magma, usually with the upper length (h{sub 2}) solidified. The style of deformation of the cone depends on both h{sub 1} and h{sub 2}. If magma is prevented from hydrofracturing out of the conduit (as, for example, might be the case if the magma is surrounded by a solidified, but plastically deformable layer acting as a gasket backed up by the brittle country rock) pressures in the magma can build to 10s of MPa. When h{sub 1} is 100 m, not unusual for a small isolated basaltic cinder cone, the magma pressure needed to destabilize the cone when molten magma extends all the way to the original ground surface (h{sub 2} = 0) is only about one-third of the pressure when the upper part of the conduit is solidified (h{sub 2} = 25m). In the former case, almost the entire upper third of the cone is at failure in tension when the configuration becomes unstable. In the latter case, small portions of the surface of the cone are failing in tension when instability occurs, but a large volume in the central core of the cone is failing in shear or compressions. These results may provide insight into the status of volcanic plumbing, either past or present, beneath scoria cones. Field observations at the Lathrop Wells volcano in southern Nevada identify structures at the outer edge just below the crater rim that appear to be inward-dipping listric normal faults. This may indicate that, near the end of its active stage, the cone was close to failing in this fashion. A companion paper suggests that such a failure could have been quite energetic had it occurred.

  9. Tantalum Cones in Revision Total Knee Arthroplasty.

    PubMed

    Kim, Eric G; Patel, Nirav K; Chughtai, Morad; Elmallah, Randa D K; Delanois, Ronald E; Harwin, Steven F; Mont, Michael A

    2016-11-01

    The best strategy to address large bony defects in revision total knee arthroplasty has yet to be determined. The relatively recent development of porous tantalum cones and their use to address massive bone loss in knee arthroplasty has shown promising short- and intermediate-term results. The purpose of this review is to present the current literature on: (1) basic science of porous tantalum, (2) classification and treatment for bone loss, (3) clinical results, and (4) evolution of newer generation cones.

  10. Causes and consequences of inherited cone disorders.

    PubMed

    Roosing, Susanne; Thiadens, Alberta A H J; Hoyng, Carel B; Klaver, Caroline C W; den Hollander, Anneke I; Cremers, Frans P M

    2014-09-01

    Hereditary cone disorders (CDs) are characterized by defects of the cone photoreceptors or retinal pigment epithelium underlying the macula, and include achromatopsia (ACHM), cone dystrophy (COD), cone-rod dystrophy (CRD), color vision impairment, Stargardt disease (STGD) and other maculopathies. Forty-two genes have been implicated in non-syndromic inherited CDs. Mutations in the 5 genes implicated in ACHM explain ∼93% of the cases. On the contrary, only 21% of CRDs (17 genes) and 25% of CODs (8 genes) have been elucidated. The fact that the large majority of COD and CRD-associated genes are yet to be discovered hints towards the existence of unknown cone-specific or cone-sensitive processes. The ACHM-associated genes encode proteins that fulfill crucial roles in the cone phototransduction cascade, which is the most frequently compromised (10 genes) process in CDs. Another 7 CD-associated proteins are required for transport processes towards or through the connecting cilium. The remaining CD-associated proteins are involved in cell membrane morphogenesis and maintenance, synaptic transduction, and the retinoid cycle. Further novel genes are likely to be identified in the near future by combining large-scale DNA sequencing and transcriptomics technologies. For 31 of 42 CD-associated genes, mammalian models are available, 14 of which have successfully been used for gene augmentation studies. However, gene augmentation for CDs should ideally be developed in large mammalian models with cone-rich areas, which are currently available for only 11 CD genes. Future research will aim to elucidate the remaining causative genes, identify the molecular mechanisms of CD, and develop novel therapies aimed at preventing vision loss in individuals with CD in the future.

  11. A novel mechanism of cone photoreceptor adaptation.

    PubMed

    Howlett, Marcus H C; Smith, Robert G; Kamermans, Maarten

    2017-04-01

    An animal's ability to survive depends on its sensory systems being able to adapt to a wide range of environmental conditions, by maximizing the information extracted and reducing the noise transmitted. The visual system does this by adapting to luminance and contrast. While luminance adaptation can begin at the retinal photoreceptors, contrast adaptation has been shown to start at later stages in the retina. Photoreceptors adapt to changes in luminance over multiple time scales ranging from tens of milliseconds to minutes, with the adaptive changes arising from processes within the phototransduction cascade. Here we show a new form of adaptation in cones that is independent of the phototransduction process. Rather, it is mediated by voltage-gated ion channels in the cone membrane and acts by changing the frequency response of cones such that their responses speed up as the membrane potential modulation depth increases and slow down as the membrane potential modulation depth decreases. This mechanism is effectively activated by high-contrast stimuli dominated by low frequencies such as natural stimuli. However, the more generally used Gaussian white noise stimuli were not effective since they did not modulate the cone membrane potential to the same extent. This new adaptive process had a time constant of less than a second. A critical component of the underlying mechanism is the hyperpolarization-activated current, Ih, as pharmacologically blocking it prevented the long- and mid- wavelength sensitive cone photoreceptors (L- and M-cones) from adapting. Consistent with this, short- wavelength sensitive cone photoreceptors (S-cones) did not show the adaptive response, and we found they also lacked a prominent Ih. The adaptive filtering mechanism identified here improves the information flow by removing higher-frequency noise during lower signal-to-noise ratio conditions, as occurs when contrast levels are low. Although this new adaptive mechanism can be driven by

  12. Simple Amides of Oleanolic Acid as Effective Penetration Enhancers

    PubMed Central

    Bednarczyk-Cwynar, Barbara; Partyka, Danuta; Zaprutko, Lucjusz

    2015-01-01

    Transdermal transport is now becoming one of the most convenient and safe pathways for drug delivery. In some cases it is necessary to use skin penetration enhancers in order to allow for the transdermal transport of drugs that are otherwise insufficiently skin-permeable. A series of oleanolic acid amides as potential transdermal penetration enhancers was formed by multistep synthesis and the synthesis of all newly prepared compounds is presented. The synthetized amides of oleanolic acid were tested for their in vitro penetration promoter activity. The above activity was evaluated by means of using the Fürst method. The relationships between the chemical structure of the studied compounds and penetration activity are presented. PMID:26010090

  13. Penetration and lateral diffusion characteristics of polycrystalline graphene barriers

    NASA Astrophysics Data System (ADS)

    Yoon, Taeshik; Mun, Jeong Hun; Cho, Byung Jin; Kim, Taek-Soo

    2013-12-01

    We report penetration and lateral diffusion behavior of environmental molecules on synthesized polycrystalline graphene. Penetration occurs through graphene grain boundaries resulting in local oxidation. However, when the penetrated molecules diffuse laterally, the oxidation region will expand. Therefore, we measured the lateral diffusion rate along the graphene-copper interface for the first time by the environment-assisted crack growth test. It is clearly shown that the lateral diffusion is suppressed due to the high van der Waals interaction. Finally, we employed bilayer graphene for a perfect diffusion barrier facilitated by decreased defect density and increased lateral diffusion path.We report penetration and lateral diffusion behavior of environmental molecules on synthesized polycrystalline graphene. Penetration occurs through graphene grain boundaries resulting in local oxidation. However, when the penetrated molecules diffuse laterally, the oxidation region will expand. Therefore, we measured the lateral diffusion rate along the graphene-copper interface for the first time by the environment-assisted crack growth test. It is clearly shown that the lateral diffusion is suppressed due to the high van der Waals interaction. Finally, we employed bilayer graphene for a perfect diffusion barrier facilitated by decreased defect density and increased lateral diffusion path. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr03849a

  14. Microspectrophotometric evidence for cone monochromacy in sharks

    NASA Astrophysics Data System (ADS)

    Hart, Nathan Scott; Theiss, Susan Michelle; Harahush, Blake Kristin; Collin, Shaun Patrick

    2011-03-01

    Sharks are apex predators, and their evolutionary success is in part due to an impressive array of sensory systems, including vision. The eyes of sharks are well developed and function over a wide range of light levels. However, whilst close relatives of the sharks—the rays and chimaeras—are known to have the potential for colour vision, an evolutionary trait thought to provide distinct survival advantages, evidence for colour vision in sharks remains equivocal. Using single-receptor microspectrophotometry, we measured the absorbance spectra of visual pigments located in the retinal photoreceptors of 17 species of shark. We show that, while the spectral tuning of the rod (wavelength of maximum absorbance, λmax 484-518 nm) and cone (λmax 532-561 nm) visual pigments varies between species, each shark has only a single long-wavelength-sensitive cone type. This suggests that sharks may be cone monochromats and, therefore, potentially colour blind. Whilst cone monochromacy on land is rare, it may be a common strategy in the marine environment: many aquatic mammals (whales, dolphins and seals) also possess only a single, green-sensitive cone type. It appears that both sharks and marine mammals may have arrived at the same visual design by convergent evolution. The spectral tuning of the rod and cone pigments of sharks is also discussed in relation to their visual ecology.

  15. Microspectrophotometric evidence for cone monochromacy in sharks.

    PubMed

    Hart, Nathan Scott; Theiss, Susan Michelle; Harahush, Blake Kristin; Collin, Shaun Patrick

    2011-03-01

    Sharks are apex predators, and their evolutionary success is in part due to an impressive array of sensory systems, including vision. The eyes of sharks are well developed and function over a wide range of light levels. However, whilst close relatives of the sharks-the rays and chimaeras-are known to have the potential for colour vision, an evolutionary trait thought to provide distinct survival advantages, evidence for colour vision in sharks remains equivocal. Using single-receptor microspectrophotometry, we measured the absorbance spectra of visual pigments located in the retinal photoreceptors of 17 species of shark. We show that, while the spectral tuning of the rod (wavelength of maximum absorbance, λ(max) 484-518 nm) and cone (λ(max) 532-561 nm) visual pigments varies between species, each shark has only a single long-wavelength-sensitive cone type. This suggests that sharks may be cone monochromats and, therefore, potentially colour blind. Whilst cone monochromacy on land is rare, it may be a common strategy in the marine environment: many aquatic mammals (whales, dolphins and seals) also possess only a single, green-sensitive cone type. It appears that both sharks and marine mammals may have arrived at the same visual design by convergent evolution. The spectral tuning of the rod and cone pigments of sharks is also discussed in relation to their visual ecology.

  16. Design of a Trichromatic Cone Array

    PubMed Central

    Klein, Jennifer M.; Sterling, Peter; Brainard, David H.; Balasubramanian, Vijay

    2010-01-01

    Cones with peak sensitivity to light at long (L), medium (M) and short (S) wavelengths are unequal in number on the human retina: S cones are rare (<10%) while increasing in fraction from center to periphery, and the L/M cone proportions are highly variable between individuals. What optical properties of the eye, and statistical properties of natural scenes, might drive this organization? We found that the spatial-chromatic structure of natural scenes was largely symmetric between the L, M and S sensitivity bands. Given this symmetry, short wavelength attenuation by ocular media gave L/M cones a modest signal-to-noise advantage, which was amplified, especially in the denser central retina, by long-wavelength accommodation of the lens. Meanwhile, total information represented by the cone mosaic remained relatively insensitive to L/M proportions. Thus, the observed cone array design along with a long-wavelength accommodated lens provides a selective advantage: it is maximally informative. PMID:20168996

  17. Photonic Landau levels on cones

    NASA Astrophysics Data System (ADS)

    Schine, Nathan; Ryou, Albert; Gromov, Andrey; Sommer, Ariel; Simon, Jonathan

    2016-05-01

    Creating photonic materials with nontrivial topological characteristics has seen burgeoning interest in recent years; however, a major route to topology, a magnetic field for continuum photons, has remained elusive. We present the first experimental realization of a bulk magnetic field for optical photons. By using a non-planar ring resonator, we induce an image rotation on each round trip through the resonator. This results in a Coriolis/Lorentz force and a centrifugal anticonfining force, the latter of which is cancelled by mirror curvature. Spatial- and energy- resolved spectroscopy tracks photonic eigenstates as residual trapping is reduced, and we observe photonic Landau levels as the eigenstates become degenerate. We will discuss the conical geometry of the resulting manifold for photon dynamics and present a measurement of the local density of states that is consistent with Landau levels on a cone. While our work already demonstrates an integer quantum Hall material composed of photons, we have ensured compatibility with strong photon-photon interactions, which will allow quantum optical studies of entanglement and correlation in manybody systems including fractional quantum Hall fluids.

  18. Photonic Landau levels on cones

    NASA Astrophysics Data System (ADS)

    Schine, Nathan; Ryou, Albert; Gromov, Andrey; Sommer, Ariel; Simon, Jonathan

    2016-05-01

    We present the first experimental realization of a bulk magnetic field for optical photons. By using a non-planar ring resonator, we induce an image rotation on each round trip through the resonator. This results in a Coriolis/Lorentz force and a centrifugal anticonfining force, the latter of which is cancelled by mirror curvature. Using a digital micromirror device to control both amplitude and phase, we inject arbitrary optical modes into our resonator. Spatial- and energy- resolved spectroscopy tracks photonic eigenstates as residual trapping is reduced, and we observe photonic Landau levels as the eigenstates become degenerate. We show that there is a conical geometry of the resulting manifold for photon dynamics and present a measurement of the local density of states that is consistent with Landau levels on a cone. While our work already demonstrates an integer quantum Hall material composed of photons, we have ensured compatibility with strong photon-photon interactions, which will allow quantum optical studies of entanglement and correlation in manybody systems including fractional quantum Hall fluids.

  19. Distributional geometry of squashed cones

    NASA Astrophysics Data System (ADS)

    Fursaev, Dmitri V.; Patrushev, Alexander; Solodukhin, Sergey N.

    2013-08-01

    A regularization procedure developed by D. V. Fursaev and S. N. Solodukhin, [Phys. Rev. D 52, 2133 (1995)PRVDAQ0556-2821] for the integral curvature invariants on manifolds with conical singularities is generalized to the case of squashed cones. In general, the squashed conical singularities do not have rotational O(2) symmetry in a subspace orthogonal to a singular surface Σ so that the surface is allowed to have extrinsic curvatures. A new feature of the squashed conical singularities is that the surface terms in the integral invariants, in the limit of a small angle deficit, now depend also on the extrinsic curvatures of Σ. A case of invariants which are quadratic polynomials of the Riemann curvature is elaborated in different dimensions and applied to several problems related to entanglement entropy. The results are in complete agreement with computations of the logarithmic terms in entanglement entropy of 4D conformal theories [S. N. Solodukhin, Phys. Lett. B 665, 305 (2008)PYLBAJ0370-2693]. Among other applications of the suggested method are logarithmic terms in entanglement entropy of nonconformal theories and a holographic formula for entanglement entropy in theories with gravity duals.

  20. Centrifuge Modeling of Projectile Penetration in Granular Soils

    DTIC Science & Technology

    1989-04-01

    Dry test samples were prepared by slowly pouring sand into the sample container from an overhead crane. Wet test samples were prepared by separately...to rest along the top of the sample buckets fore, dry test saMple5, the impact crater was carefully excavated by hand until the top surface of the...Florida Beach Sand; MX = Soil Blend 140 Table F-2. PENETRATION TEST DATA’ - MOIST SAND Proj. Soil Dry Test G Depth Velocity2 Soil Density Moisture

  1. Effect of DOP heterodispersion on HEPA-filter-penetration measurements

    SciTech Connect

    Bergman, W.; Biermann, A.

    1984-08-09

    The accuracy of the standard US test method for certifying High-Efficiency Particulate Air (HEPA) filters has been in question since the finding by Hinds, et al. that the dioctyl phthalate (DOP) aerosol used in the test is not monodisperse as had been assumed and that particle-size analyzers, or owls, could not distinguish between different particle-size distributions with the same owl reading. We have studied theoretically and experimentally the filter efficiency for different DOP size distributions with the same owl reading. Our studies show that the effect of varying DOP size distributions on the measured HEPA-filter penetration depends on the light-scattering-photometer response and on the HEPA-filter penetration curve, both measured as a function of particle size. HEPA-filter penetration for a heterodisperse DOP aerosol may be increased, decreased, or remain the same when compared to the filter penetration for monodisperse aerosols. Using experimental HEPA-filter penetration and photometer response curves, we show that heterodisperse DOP aerosols (D/sub cmd/ 0.19 and sigma g = 1.4) yield 24% lower penetrations than that for monodisperse DOP aerosols (D/sub cmd/ = 0.3 and sigma g = 1.0). This surprisingly small effect of the DOP heterodispersion on HEPA-filter penetration is due to the response function of the owl that is similar to the response of the photometer. Changes in the particle-size distribution are therefore seen in a similar fashion by both the photometer and the owl. We also show that replacing the owl with modern particle-size spectrometers may lead to large errors in filter penetration because the particle-size spectrometers do not provide measurements that correspond to the photometer measurements. 15 references, 16 figures.

  2. Localizing Ground-Penetrating Radar

    DTIC Science & Technology

    2014-11-01

    determine the vehicles location when adverse conditions, such as heavy rain or fog , snow-covered roads, or lost GPS signals, hamper the...penetrate rain, fog , dust, and snow. LGPR Methodology For subsurface sensing, GPR is one of the most versatile and prolific sensing modal- ities today

  3. Magnetically-Guided Penetrant Applicator

    NASA Technical Reports Server (NTRS)

    Molina, Orlando G.

    1990-01-01

    Small wheeled vehicle moved inside nonmagnetic enclosure. Miniature magnetically guided truck uses foam-rubber sponge pads to apply penetrant fluid for inspection of welds in hidden surfaces of nonmagnetic tubes. Risk of explosion less than if electric motor used to drive vehicle. Inexpensive to make and made in range of sizes.

  4. Opsin switch reveals function of the ultraviolet cone in fish foraging

    PubMed Central

    Novales Flamarique, Iñigo

    2013-01-01

    Although several studies have shown that ultraviolet (UV) wavelengths are important in naturally occurring, visually guided behaviours of vertebrates, the function of the UV cone in such behaviours is unknown. Here, I used thyroid hormone to transform the UV cones of young rainbow trout into blue cones, a phenomenon that occurs naturally as the animal grows, to test whether the resulting loss of UV sensitivity affected the animal's foraging performance on Daphnia magna, a prey zooplankton. The distances and angles at which prey were located (variables that are known indicators of foraging performance) were significantly reduced for UV knock-out fish compared with controls. Optical measurements and photon-catch calculations revealed that the contrast of Daphnia was greater when perceived by the visual system of control versus that of thyroid-hormone-treated fish, demonstrating that the UV cone enhanced the foraging performance of young rainbow trout. Because most juvenile fishes have UV cones and feed on zooplankton, this finding has wide implications for understanding the visual ecology of fishes. The enhanced target contrast provided by UV cones could be used by other vertebrates in various behaviours, including foraging, mate selection and communication. PMID:23222448

  5. Diminished foraging performance of a mutant zebrafish with reduced population of ultraviolet cones

    PubMed Central

    Novales Flamarique, Iñigo

    2016-01-01

    Ultraviolet (UV) cones are photoreceptors that sense light in the range 300–450 nm and are found in the retinas of non-mammalian vertebrates and small mammals. Despite their widespread presence across taxa, the functions that these cones exert in the lives of animals remain largely unknown. In this study, I used the zebrafish lor (lots of rods) mutant, characterized by a diminished UV cone population compared to that of wild-type zebrafish, to test whether its foraging performance differed from that of the wild-type (control). The mean location distance and angle (variables that are reliable indicators of foraging performance) at which control fish detected zooplankton prey were, on average, 24 and 90% greater than corresponding measures for lor fish. Such inferior foraging performance of the mutant could be explained by reduced contrast perception of the prey, resulting from the diminished population of UV cones and associated sensitivity. Thus, UV cones enhance the foraging performance of zebrafish, a crucial ecological function that may explain why small zooplanktivorous fishes retain UV cones throughout their lives. PMID:26936243

  6. Prevention of retrograde calculus migration with the Stone Cone.

    PubMed

    Pardalidis, N P; Papatsoris, A G; Kosmaoglou, E V

    2005-02-01

    Retrograde calculus migration during ureteroscopic lithotripsy remains a problem in 5-40% of cases. We assessed the safety and efficacy of the Stone Cone device, in comparison with the standard flat wire basket. A total of 56 consecutive patients with ureteral calculi, suitable for ureteroscopic extraction and/or lithotripsy, where included in this prospective study. Patients were randomly allocated into two groups. In group A (30 patients), we used the Stone Cone, while in group B (26 patients) we used the standard flat wire basket. The Stone Cone was placed through a cystoscope under fluoroscopic guidance, or when necessary under direct ureteroscopic control. Whenever necessary, intracorporeal electrohydraulic lithotripsy took place in both groups. Statistical significance was assessed by the paired t-test. The mean operative time was 48.5 min in group A, and 42.4 min in group B. Intact calculus extraction was possible in 16.6% in group A, and in 7.6% in group B (P < 0.01). Retrograde stone migration was revealed in 23% in group B only (P < 0.001). Also, residual fragments > 3 mm were recorded in 30.7% in group B only (P < 0.001). None of the patients in group A required auxiliary procedures, in contrary to 23% in group B (P < 0.001). No major complications were recorded in group A, while in group B a case of major ureteral mucosal abrasion was recorded. The Stone Cone is safe and efficient in preventing retrograde stone migration and in minimizing residual fragments during ureteroscopic lithotripsy in comparison with the flat wire basket.

  7. Nonhost Root Penetration by Soybean Cyst Nematode

    PubMed Central

    Riggs, R. D.

    1987-01-01

    A total of 66 plants in 50 species were inoculated with eggs and juveniles of soybean cyst nematode, Heterodera glycines. Roots were stained and observed for penetration and development of the nematode. Twenty-six plants were not penetrated; twenty-three were penetrated, but there was no development of the nematode; eight were penetrated with some nematode development; two were penetrated and had considerable nematode development, but few nematodes, if any, matured; and seven were penetrated with many nematodes maturing. The penetration of nonhosts may imply some susceptibility and that populations eventually would build up on the penetrated plants. Plants not penetrated may be useful as rotation plants because no reproduction would occur. PMID:19290137

  8. 40 CFR 1065.376 - Chiller NO2 penetration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... CONTROLS ENGINE-TESTING PROCEDURES Calibrations and Verifications Nox and N2o Measurements § 1065.376... this verification for chiller NO2 penetration. Perform this verification after initial installation and... would before emission testing. (ii) Select an NO2 calibration gas, balance gas of dry air, that has...

  9. 40 CFR 1065.376 - Chiller NO2 penetration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... CONTROLS ENGINE-TESTING PROCEDURES Calibrations and Verifications Nox and N2o Measurements § 1065.376... this verification for chiller NO2 penetration. Perform this verification after initial installation and... would before emission testing. (ii) Select an NO2 calibration gas, balance gas of dry air, that has...

  10. 40 CFR 1065.376 - Chiller NO2 penetration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... CONTROLS ENGINE-TESTING PROCEDURES Calibrations and Verifications Nox and N2o Measurements § 1065.376... this verification for chiller NO2 penetration. Perform this verification after initial installation and... would before emission testing. (ii) Select an NO2 calibration gas, balance gas of dry air, that has...

  11. 40 CFR 1065.376 - Chiller NO2 penetration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... CONTROLS ENGINE-TESTING PROCEDURES Calibrations and Verifications Nox and N2o Measurements § 1065.376... this verification for chiller NO2 penetration. Perform this verification after initial installation and... would before emission testing. (ii) Select an NO2 calibration gas, balance gas of dry air, that has...

  12. Multiple rod-cone and cone-rod photoreceptor transmutations in snakes: evidence from visual opsin gene expression.

    PubMed

    Simões, Bruno F; Sampaio, Filipa L; Loew, Ellis R; Sanders, Kate L; Fisher, Robert N; Hart, Nathan S; Hunt, David M; Partridge, Julian C; Gower, David J

    2016-01-27

    In 1934, Gordon Walls forwarded his radical theory of retinal photoreceptor 'transmutation'. This proposed that rods and cones used for scotopic and photopic vision, respectively, were not fixed but could evolve into each other via a series of morphologically distinguishable intermediates. Walls' prime evidence came from series of diurnal and nocturnal geckos and snakes that appeared to have pure-cone or pure-rod retinas (in forms that Walls believed evolved from ancestors with the reverse complement) or which possessed intermediate photoreceptor cells. Walls was limited in testing his theory because the precise identity of visual pigments present in photoreceptors was then unknown. Subsequent molecular research has hitherto neglected this topic but presents new opportunities. We identify three visual opsin genes, rh1, sws1 and lws, in retinal mRNA of an ecologically and taxonomically diverse sample of snakes central to Walls' theory. We conclude that photoreceptors with superficially rod- or cone-like morphology are not limited to containing scotopic or photopic opsins, respectively. Walls' theory is essentially correct, and more research is needed to identify the patterns, processes and functional implications of transmutation. Future research will help to clarify the fundamental properties and physiology of photoreceptors adapted to function in different light levels.

  13. Comparative analysis between mandibular positions in centric relation and maximum intercuspation by cone beam computed tomography (CONE-BEAM).

    PubMed

    Ferreira, Amanda de Freitas; Henriques, João César Guimarães; Almeida, Guilherme Araújo; Machado, Asbel Rodrigues; Machado, Naila Aparecida de Godoi; Fernandes Neto, Alfredo Júlio

    2009-01-01

    This research consisted of a quantitative assessment, and aimed to measure the possible discrepancies between the maxillomandibular positions for centric relation (CR) and maximum intercuspation (MI), using computed tomography volumetric cone beam (cone beam method). The sample of the study consisted of 10 asymptomatic young adult patients divided into two types of standard occlusion: normal occlusion and Angle Class I occlusion. In order to obtain the centric relation, a JIG device and mandible manipulation were used to deprogram the habitual conditions of the jaw. The evaluations were conducted in both frontal and lateral tomographic images, showing the condyle/articular fossa relation. The images were processed in the software included in the NewTom 3G device (QR NNT software version 2.00), and 8 tomographic images were obtained per patient, four laterally and four frontally exhibiting the TMA's (in CR and MI, on both sides, right and left). By means of tools included in another software, linear and angular measurements were performed and statistically analyzed by student t test. According to the methodology and the analysis performed in asymptomatic patients, it was not possible to detect statistically significant differences between the positions of centric relation and maximum intercuspation. However, the resources of cone beam tomography are of extreme relevance to the completion of further studies that use heterogeneous groups of samples in order to compare the results.

  14. Penetration of nanoparticles into human skin.

    PubMed

    Liang, Xiao Wen; Xu, Zhi Ping; Grice, Jeffrey; Zvyagin, Andrei V; Roberts, Michael S; Liu, Xin

    2013-01-01

    Exposure of human skin to nanoparticles (NPs) is increasing with the development of nanotechnology and new applications of NPs in medicine. Safety concerns have sparked debate on the capacity of NPs to penetrate through skin and enter into the body. This article attempts to summarize the recent evidence on whether NPs penetrate human skin and the factors that may affect the penetration. Skin structure and penetration mechanisms are reviewed to provide background information. Size, shape, formulation, surface properties and application methods and their effects on skin penetration are specifically discussed. Finally, the relationship between skin penetration and nanotoxicity is reviewed to further emphasise the importance of the research in this area.

  15. Akon - A Penetrator for Europa

    NASA Astrophysics Data System (ADS)

    Jones, Geraint

    2016-04-01

    Jupiter's moon Europa is one of the most intriguing objects in our Solar System. This 2000km-wide body has a geologically young solid water ice crust that is believed to cover a global ocean of liquid water. The presence of this ocean, together with a source of heating through tidal forces, make Europa a conceivable location for extraterrestrial life. The science case for exploring all aspects of this icy world is compelling. NASA has selected the Europa Mission (formerly Europa Clipper) to study Europa in detail in the 2020s through multiple flybys, and ESA's JUICE mission will perform two flybys of the body in the 2030s. The US agency has extended to the European Space Agency an invitation to provide a contribution to their mission. European scientists interested in Europa science and exploration are currently organizing themselves, in the framework of a coordinated Europa M5 Inititative to study concurrently the main options for this ESA contribution, from a simple addition of individual instruments to the NASA spacecraft, to a lander to investigate Europa's surface in situ. A high speed lander - a penetrator - is by far the most promising technology to achieve this latter option within the anticipated mass constraints, and studies of such a hard lander, many funded by ESA, are now at an advanced level. An international team to formally propose an Europa penetrator to ESA in response to the anticipated ESA M5 call is growing. The working title of this proposal is Akon (Άκων), named after the highly accurate javelin gifted to Europa by Zeus in ancient Greek mythology. We present plans for the Akon penetrator, which would impact Europa's surface at several hundred metres per second, and travel up to several metres into the moon's subsurface. To achieve this, the penetrator would be delivered to the surface by a dedicated descent module, to be destroyed on impact following release of the penetrator above the surface. It is planned that the instruments to be

  16. Polymorphism of the long-wavelength cone in normal human colour vision

    NASA Astrophysics Data System (ADS)

    Neitz, Jay; Jacobs, Gerald H.

    1986-10-01

    Colour vision is based on the presence of multiple classes of cone each of which contains a different type of photopigment1. Colour matching tests have long revealed that the normal human has three cone types. Results from these tests have also been used to provide estimates of cone spectral sensitivities2. There are significant variations in colour matches made by individuals whose colour vision is classified as normal3-6. Some of this is due to individual differences in preretinal absorption and photopigment density, but some is also believed to arise because there is variation in the spectral positioning of the cone pigments among those who have normal colour vision. We have used a sensitive colour matching test to examine the magnitude and nature of this individual variation and here report evidence for the existence of two different long-wavelength cone mechanisms in normal humans. The different patterns of colour matches made by male and female subjects indicate these two mechanisms are inherited as an X-chromosome linked trait.

  17. Comparative evaluation of tensile strength of Gutta-percha cones with a herbal disinfectant

    PubMed Central

    Mahali, Raghunandhan Raju; Dola, Binoy; Tanikonda, Rambabu; Peddireddi, Suresh

    2015-01-01

    Aim: To evaluate and compare the tensile strength values and influence of taper on the tensile strength of Gutta-percha (GP) cones after disinfection with sodium hypochlorite (SH) and Aloe vera gel (AV). Materials and Methods: Sixty GP cones of size 110, 2% taper, 60 GP cones F3 ProTaper, and 60 GP of size 30, 6% taper were obtained from sealed packs as three different groups. Experimental groups were disinfected with 5.25% SH and 90% AV gel except the control group. Tensile strengths of GP were measured using the universal testing machine. Results: The mean tensile strength values for Group IA, IIA and IIIA are 11.8 MPa, 8.69 MPa, and 9.24 MPa, respectively. Results were subjected to statistical analysis one-way analysis of variance test and Tukey post-hoc test. 5.25% SH solutions decreased the tensile strength of GP cones whereas with 90% AV gel it was not significantly altered. Conclusion: Ninety percent Aloe vera gel as a disinfectant does not alter the tensile strength of GP cones PMID:26752842

  18. Pulsating Electrohydrodynamic Cone-Jets: from Choked Jet to Oscillating Cone

    NASA Astrophysics Data System (ADS)

    Bober, David; Chen, Chuan-Hua

    2011-11-01

    Pulsating cone-jets occur in a variety of electrostatic spraying and printing systems. We report an experimental study of the pulsation frequency to reconcile two models based on a choked jet and an oscillating cone, respectively. The two regimes are demarcated by the ratio of the supplied flow rate (Qs) to the minimum flow rate (Qm) required for a steady Taylor cone-jet. When Qs Qm , the Taylor cone anchored at the nozzle experiences a capillary oscillation analogous to the Rayleigh mode of a free drop; the pulsation frequency in the oscillating cone regime plateaus to the capillary oscillation frequency which is independent of Qs /Qm .

  19. A bioassay to estimate root penetration by nematodes.

    PubMed

    Kaplan, D T; Davis, E L

    1991-10-01

    An in vitro bioassay with a 96-well microtiter plate was used to study the effect of lectins on burrowing nematode penetration of citrus roots. In each well, one 4-mm root segment, excised from the zone of elongation of rough lemon roots, was buried in 0.88 g dry sand. Addition of a Radopholus citrophilus suspension containing ca. 300 nematodes in 50 mu1 test solution completely moistened the sand in each well. The technique assured uniform treatment concentration throughout the medium. Within 16-24 hours, burrowing nematodes penetrated citrus root pieces, primarily through the cut ends. The lectins (100 mug/ml) Concanavalin A (Con A), soybean agglutinin (SBA), wheat germ agglutinin (WGA), and Lotus tetragonolobus agglutinin (LOT) stimulated an increase in penetration of citrus root segments by Radopholus citrophilus. Concentrations as low as 12.5 mug/ml Con A, LOT, and WGA stimulated burrowing nematode penetration of citrus roots. Heat denaturation of the lectins reversed their effect on penetration; however, incubation of nematodes in lectin (25 mug/ml) with 25 mM competitive sugars did not. The reason for enhanced penetration associated with lectins is unclear.

  20. Design study of fiber-composite penetrator cases

    SciTech Connect

    Logan, R.W.; Groves, S.E.; Lyon, R.E.

    1993-10-22

    A design study was conducted to demonstrate the viability of carbon-fiber reinforced epoxy composites as structural case materials for penetrating warheads. The objective was to conduct well-instrumented experimental studies of composite-body penetrators perforating mild steel plates and quantitatively model these plate penetrations using two- and three-dimensional finite element codes over a wide range of velocities and impact conditions in order to develop predictive capability for composite design and for use in tradeoff studies with existing case materials. Understanding of the failure of composite-body penetrators would be demonstrated by a rational design iteration which significantly improved performance. Initial studies utilized existing 1-degree tapered cylindrical carbon fiber/epoxy composite cases fabricated by wet-filament winding. These sharp-tipped, steel-nose, composite penetrators were strain-gaged, piggy-backed with 57 kilograms, and impacted into steel plates in a velocity-boosted droptower at impact velocities ranging from 3 to 18 meters per second. Load, time, and position data were recorded during the impact event as well as the axial and hoop strains in the composite case. Monolithic 4340 hardened steel penetrators with both sharp- and flat-tip 3-caliber ogive noses were also impacted into mild steel plates. Data from the composite-case and steel penetrators were used to calibrate a multiaxial, rate-dependent, flow and failure model for the mild steel plates in NIKE2D. The authors were then able to successfully predict survival and failure of the composite-case penetrators in normal-incidence droptower tests for different target thickness and velocity combinations.

  1. Supersonic Free-Flight Measurements of Heat Transfer and Transition on a 10 degree Cone having a Low Temperature Ratio

    NASA Technical Reports Server (NTRS)

    Merlet, Charles F.; Rumsey, Charles B.

    1961-01-01

    Heat-transfer coefficients in the form of Stanton number and boundary-layer transition data were obtained from a free-flight test of a 100-inch-long 10 deg. total-angle cone with a 1/16-inch tip radius which penetrated deep into the region of infinite stability of laminar boundary layer over a range of wall-to-local-stream temperature radius and for local Mach numbers from 1.8 to 3.5. Experimental heat-transfer coefficients, obtained at Reynolds numbers up to 160 x 10(exp 6), were in general somewhat higher than theoretical values. A maximum Reynolds number of transition of only 33 x 10(exp 6) was obtained. Contrary to theoretical and some other experimental investigations, the transition Reynolds number initially increased while the wall temperature ratio increased at relatively constant Mach number. Further increases in wall temperature ratio were accompanied by a decrease in transition Reynolds number. Increasing transition Reynolds number with increasing Mach number was also indicated at a relatively constant wall temperature ratio.

  2. Factors affecting penetrating captive bolt gun performance.

    PubMed

    Gibson, Troy J; Mason, Charles W; Spence, Jade Y; Barker, Heather; Gregory, Neville G

    2015-01-01

    Captive bolt stunning is used for rendering livestock insensible at slaughter. The mechanical factors relating to performance of 6 penetrating captive bolt gun (CBG) models were examined. The Matador Super Sécurit 3000 and the .25 Cash Euro Stunner had the highest kinetic energy values (443 J and 412 J, respectively) of the CBGs tested. Ninety percent (27/30) of CBGs held at a government gun repository (United Kingdom) were found to have performed at a normal standard for the model, while 53% (10/19) of commercial contractor CBGs tested were found to underperform for the gun model. When the .22 Cash Special was fired 500 times at 4 shots per min, the gun reached a peak temperature of 88.8°C after 2.05 hr. Repeat firing during extended periods significantly reduced the performance of the CBG. When deciding on the appropriate CBG/cartridge combination, the kinetic energy delivered to the head of the nonhuman animal, bolt penetration depth, and species/animal type must be considered. It is recommended that CBGs are routinely checked for wear to the bolt and barrel if they are repeatedly fired in a session.

  3. Study of multilayered insulation pipe penetration. Thermal acoustic oscillation

    NASA Technical Reports Server (NTRS)

    Lovin, J. K.

    1974-01-01

    Tests were conducted to determine the net heat leak to a source of liquid nitrogen caused by a metal penetration through the blanket of multilayer insulation. The conditions under which the tests were conducted are described. A graph of the theoretical and experimental temperature distribution is developed for comparison. The variables involved in the computer program to process the data are defined. A study was conducted to develop analytical methods for predicting the effect and magnitudes of thermoacoustic oscillations on the penetration heat leak to cryogens. The oscillations develop as a result of large thermal gradients imposed on a compressible fluid. The predominant amplitudes and frequencies of the thermal acoustic oscillations were investigated.

  4. IPMN penetration of the stomach.

    PubMed

    Nakano, Masakazu; Tominaga, Keiichi; Watanabe, Hidetaka; Kanke, Kazunari; Tamano, Masaya; Hiraishi, Hideyuki

    2010-01-01

    An 83-year old Japanese man was transferred to our hospital due to a 1-week history of melena and signs of disordered awareness. Esophagogastroduodenoscopy showed a villous tumor associated with massive white mucous discharge in the posterior wall of the gastric corpus, where pathologically identified mucin-producing epithelium with nuclear atypia had developed into a papillary form. An abdominal enhanced computed tomography scan demonstrated communication between the dilated main pancreatic duct and the gastric lumen. Based on these findings, we reached a diagnosis of gastric penetration by an intraductal papillary mucinous neoplasm (IPMN) of the main pancreatic duct. IPMN is partly characterized by expansive mucinous growth that may result in penetration into adjacent organs.

  5. EFFECT OF NOSE SHAPE ON LONG ROD PENETRATION INTO DRY SAND

    SciTech Connect

    Collins, Adam; Addiss, John; Proud, William

    2009-12-28

    Flat, hemispherical and ogive-2 nosed mild steel projectiles (10 mm diameter, 100 mm length) were fired at 200 m s{sup -1} into the end face of cylindrically confined dry sand (100 mm diameter, 150 mm length). Projectiles were tracked through the sand using flash radiography and high speed photography. By seeding a horizontal plane of randomly dispersed lead shot (<1.5 mm diameter) across the centre of the cylinder, the displacement field induced by the impact was mapped using Digital Speckle Radiography (DSR). By imaging at successive time intervals, a temporal history of the penetration was generated. DSR reveals a cone of displacement emanating from the impact point in all cases, leaving areas unmoved during the early stages of penetration. The magnitude and extent of the displacement cone is observed to be greatest in the flat nosed case. Initial rapid deceleration is seen in all nose cases, relaxing to an approximately steady velocity as the projectile reaches the end of the target. Ogive nosed projectiles suffer the least initial deceleration, and perforate the target with greatest speed. This combined behaviour is attributed to the blunt projectiles transferring more energy into movement of sand in the early stages of penetration, and hence experiencing more effective drag. Following this, the projectile moves through a moving body of sand at approximately constant velocity.

  6. Strain engineering of Dirac cones in graphyne

    SciTech Connect

    Wang, Gaoxue; Kumar, Ashok; Pandey, Ravindra; Si, Mingsu

    2014-05-26

    6,6,12-graphyne, one of the two-dimensional carbon allotropes with the rectangular lattice structure, has two kinds of non-equivalent anisotropic Dirac cones in the first Brillouin zone. We show that Dirac cones can be tuned independently by the uniaxial compressive strain applied to graphyne, which induces n-type and p-type self-doping effect, by shifting the energy of the Dirac cones in the opposite directions. On the other hand, application of the tensile strain results into a transition from gapless to finite gap system for the monolayer. For the AB-stacked bilayer, the results predict tunability of Dirac-cones by in-plane strains as well as the strain applied perpendicular to the plane. The group velocities of the Dirac cones show enhancement in the resistance anisotropy for bilayer relative to the case of monolayer. Such tunable and direction-dependent electronic properties predicted for 6,6,12-graphyne make it to be competitive for the next-generation electronic devices at nanoscale.

  7. Jeeps Penetrating a Hostile Desert

    ERIC Educational Resources Information Center

    Bailey, Herb

    2009-01-01

    Several jeeps are poised at base camp on the edge of a desert aiming to escort one of them as far as possible into the desert, while the others return to camp. They all have full tanks of gas and share their fuel to maximize penetration. In a friendly desert it is best to leave caches of fuel along the way to help returning jeeps. We solve the…

  8. Computational Model for Armor Penetration

    DTIC Science & Technology

    1987-10-01

    the penetration calculation with a slide line in the target, the impact velocity was artificially raised to avoid impact of the projectile sides onto...Lagrangian equations governing motion of a continuous medium. The solution technique is called the method of artificial viscosity because of the...fronts, although no discontinuities occur in the computed flow field. With this artificial viscosity method, the equations of continuous flow can be

  9. Soil Penetration Rates by Earthworms and Plant Roots- Mechanical and Energetic Considerations

    NASA Astrophysics Data System (ADS)

    Ruiz, Siul; Schymanski, Stan; Or, Dani

    2016-04-01

    We analyze the implications of different soil burrowing rates by earthworms and growing plant roots using mechanical models that consider soil rheological properties. We estimate the energetic requirements for soil elasto-viscoplastic displacement at different rates for similar burrows and water contents. In the core of the mechanical model is a transient cavity expansion into viscoplastic wet soil that mimic an earthworm or root tip cone-like penetration and subsequent cavity expansion due to pressurized earthworm hydrostatic skeleton or root radial growth. Soil matrix viscoplatic considerations enable separation of the respective energetic requirements for earthworms penetrating at 2 μm/s relative to plant roots growing at 0.2 μm/s . Typical mechanical and viscous parameters are obtained inversely for soils under different fixed water contents utilizing custom miniaturized cone penetrometers at different fixed penetration rates (1 to 1000 μm/s). Experimental results determine critical water contents where soil exhibits pronounced viscoplatic behavior (close to saturation), bellow which the soil strength limits earthworms activity and fracture propagation by expanding plant roots becomes the favorable mechanical mode. The soil mechanical parameters in conjunction with earthworm and plant root physiological pressure limitations (200 kPa and 2000 kPa respectively) enable delineation of the role of soil saturation in regulating biotic penetration rates for different soil types under different moisture contents. Furthermore, this study provides a quantitative framework for estimating rates of energy expenditure for soil penetration, which allowed us to determine maximum earthworm population densities considering soil mechanical properties and the energy stored in soil organic matter.

  10. Fast electron generation in cones with ultraintense laser pulses

    SciTech Connect

    Van Woerkom, L.; Chowdhury, E.; Link, A.; Offermann, D.; Ovchinnikov, V.; Schumacher, D. W.; Akli, K. U.; Stephens, R. B.; Bartal, T.; Beg, F. N.; Chawla, S.; King, J. A.; Ma, T.; Chen, C. D.; Freeman, R. R.; Hey, D.; Key, M. H.; MacKinnon, A. J.; MacPhee, A. G.; Patel, P. K.

    2008-05-15

    Experimental results from copper cones irradiated with ultraintense laser light are presented. Spatial images and total yields of Cu K{sub {alpha}} fluorescence were measured as a function of the laser focusing properties. The fluorescence emission extends into the cone approximately 300 {mu}m from the cone tip and cannot be explained by ray tracing including cone wall absorption. In addition, the total fluorescence yield from cones is an order of magnitude higher than for equivalent mass foil targets. Indications are that the physics of the laser-cone interaction is dominated by preplasma created from the long duration, low-energy prepulse from the laser.

  11. Behavior of Segmented Rods during Penetration

    DTIC Science & Technology

    1990-07-01

    full-scale penetrators which had been swaged 24%. The density of this tungsten alloy was 17.2 Mg/m 3. Gold-alloy penetrators were composed of 92Au-4.9Ag...of behavior. Segmented rods of tungsten alloy always penetrated less than the equivalent unitary rod. Successive rod segments were found to...gold-alloy penetrators because unitary rods of this material surpassed the perform- ance of unitary tungsten -alloy rods, while leaving almost no

  12. Problems in the NDT world: The penetrant inspection method

    SciTech Connect

    Marks, D. )

    1994-10-01

    When discussing a subject like non-destructive testing (NDT) with other professionals who have basically the same qualifications and certifications as yourself, it becomes apparent that the liquid penetrant method of examination is often chosen as the simplest and easiest method for many applications. No matter how simple an NDT application may seem, however, the bottom line is that the desired results of the application reveal the true status of the item under inspection. Therefore, it is very important that the personnel performing any NDT function possess the skills and knowledge of the specific discipline being applied. This article addresses some basic questions concerning liquid penetrant testing. It is the intent of this paper to help NDT personnel obtain a better understanding of the many approaches industry has in developing guidelines for the penetrant discipline.

  13. Experimental Study of Second-Mode Instabilities on a 7-Degree Cone at Mach 6

    NASA Technical Reports Server (NTRS)

    Rufer, Shann J.; Berridge, Dennis C.

    2011-01-01

    Experiments have been carried out in the NASA Langley Research Center 20-Inch Mach 6 Air Tunnel to measure the second-mode boundary-layer instability on a 7deg half-angle cone using high-frequency pressure sensors. Data were obtained with both blunt and sharp nosetips installed on the cone. The second-mode wave amplitudes were observed to saturate and then begin to decrease in the Langley tunnels, indicating wave breakdown. Pressure fluctuation measurements and thermocouple data indicated the location of transition along the cone at the different conditions tested. Comparisons between the power density spectra obtained during the current test and previous data from the Langley 15-Inch Mach 6 High Temperature Tunnel and the Boeing/AFOSR Mach 6 Quiet tunnel illustrate the effect of tunnel noise on instability growth and transition.

  14. In vitro human skin penetration model for organophosphorus compounds with different physicochemical properties.

    PubMed

    Thors, L; Koch, B; Koch, M; Hägglund, L; Bucht, A

    2016-04-01

    A flow-through diffusion cell was validated for in vitro human epidermal penetration studies of organophosphorus compounds (OPCs) applied by infinite dosing. By testing OPCs with similar molecular weight but different physicochemical properties, it was shown that hydrophilic and lipophilic properties are major determinants for the penetration rate. Lipophilic OPCs displayed maximum cumulative penetration in the 20-75% agent concentration range whereas the hydrophilic OPCs displayed maximum cumulative penetration at 10 or 20% agent concentration. Low penetration was observed for all agents at 1% agent concentration or when applied as neat agents. The impact of the receptor solution composition was evaluated by comparing the penetration using receptor solutions of different ratios of ethanol and water. For diluted OPCs, a high concentration of ethanol in the receptor solution significantly increased the penetration compared to lower concentrations. When OPCs were applied as neat agents, the composition of the receptor solution only affected the penetration for one of four tested compounds. In conclusion, the flow-through diffusion cell was useful for examining the penetration of OPCs through the epidermal membrane. It was also demonstrated that the penetration rates of OPCs are strongly influenced by dilution in water and the receptor fluid composition.

  15. Optimization over Multi-order Cones

    DTIC Science & Technology

    2011-02-01

    Department of Mathematics Technical Report 2011-1 Optimization over multi-order cones Baha ’ M. Alzalg and K. A. Ariyawansa February 2011 Postal...Prescribed by ANSI Std Z39-18 Optimization over multi-order cones Baha M. Alzalg∗ and K. A. Ariyawansa† Abstract In this paper we propose multi-order cone...that x ∈ Qnp , and x 〈n〉 〈p〉 y to mean that x− y 〈n〉 〈p〉 0. Given 1 ≤ pi ≤ ∞ for i = 1, 2, · · · , r. Let Q 〈n1,n2,··· ,nr〉 〈p1,p2,··· ,pr〉 := Qn1p1

  16. Hygroscopic motions of fossil conifer cones

    PubMed Central

    Poppinga, Simon; Nestle, Nikolaus; Šandor, Andrea; Reible, Bruno; Masselter, Tom; Bruchmann, Bernd; Speck, Thomas

    2017-01-01

    Conifer cones represent natural, woody compliant structures which move their scales as passive responses to changes in environmental humidity. Here we report on water-driven opening and closing motions in coalified conifer cones from the Eemian Interglacial (approx. 126,000–113,000 years BP) and from the Middle Miocene (approx. 16.5 to 11.5 million years BP). These cones represent by far the oldest documented evidence of plant parts showing full functionality of such passive hydraulically actuated motion. The functional resilience of these structures is far beyond the biological purpose of seed dispersal and protection and is because of a low level of mineralization of the fossils. Our analysis emphasizes the functional-morphological integrity of these biological compliant mechanisms which, in addition to their biological fascination, are potentially also role models for resilient and maintenance-free biomimetic applications (e.g., adaptive and autonomously moving structures including passive hydraulic actuators). PMID:28074936

  17. Hygroscopic motions of fossil conifer cones.

    PubMed

    Poppinga, Simon; Nestle, Nikolaus; Šandor, Andrea; Reible, Bruno; Masselter, Tom; Bruchmann, Bernd; Speck, Thomas

    2017-01-11

    Conifer cones represent natural, woody compliant structures which move their scales as passive responses to changes in environmental humidity. Here we report on water-driven opening and closing motions in coalified conifer cones from the Eemian Interglacial (approx. 126,000-113,000 years BP) and from the Middle Miocene (approx. 16.5 to 11.5 million years BP). These cones represent by far the oldest documented evidence of plant parts showing full functionality of such passive hydraulically actuated motion. The functional resilience of these structures is far beyond the biological purpose of seed dispersal and protection and is because of a low level of mineralization of the fossils. Our analysis emphasizes the functional-morphological integrity of these biological compliant mechanisms which, in addition to their biological fascination, are potentially also role models for resilient and maintenance-free biomimetic applications (e.g., adaptive and autonomously moving structures including passive hydraulic actuators).

  18. Hygroscopic motions of fossil conifer cones

    NASA Astrophysics Data System (ADS)

    Poppinga, Simon; Nestle, Nikolaus; Šandor, Andrea; Reible, Bruno; Masselter, Tom; Bruchmann, Bernd; Speck, Thomas

    2017-01-01

    Conifer cones represent natural, woody compliant structures which move their scales as passive responses to changes in environmental humidity. Here we report on water-driven opening and closing motions in coalified conifer cones from the Eemian Interglacial (approx. 126,000–113,000 years BP) and from the Middle Miocene (approx. 16.5 to 11.5 million years BP). These cones represent by far the oldest documented evidence of plant parts showing full functionality of such passive hydraulically actuated motion. The functional resilience of these structures is far beyond the biological purpose of seed dispersal and protection and is because of a low level of mineralization of the fossils. Our analysis emphasizes the functional-morphological integrity of these biological compliant mechanisms which, in addition to their biological fascination, are potentially also role models for resilient and maintenance-free biomimetic applications (e.g., adaptive and autonomously moving structures including passive hydraulic actuators).

  19. Hurricane track forecast cones from fluctuations.

    PubMed

    Meuel, T; Prado, G; Seychelles, F; Bessafi, M; Kellay, H

    2012-01-01

    Trajectories of tropical cyclones may show large deviations from predicted tracks leading to uncertainty as to their landfall location for example. Prediction schemes usually render this uncertainty by showing track forecast cones representing the most probable region for the location of a cyclone during a period of time. By using the statistical properties of these deviations, we propose a simple method to predict possible corridors for the future trajectory of a cyclone. Examples of this scheme are implemented for hurricane Ike and hurricane Jimena. The corridors include the future trajectory up to at least 50 h before landfall. The cones proposed here shed new light on known track forecast cones as they link them directly to the statistics of these deviations.

  20. Hydrogeologic structure underlying a recharge pond delineated with shear-wave seismic reflection and cone penetrometer data

    USGS Publications Warehouse

    Haines, S.S.; Pidlisecky, A.; Knight, R.

    2009-01-01

    With the goal of improving the understanding of the subsurface structure beneath the Harkins Slough recharge pond in Pajaro Valley, California, USA, we have undertaken a multimodal approach to develop a robust velocity model to yield an accurate seismic reflection section. Our shear-wave reflection section helps us identify and map an important and previously unknown flow barrier at depth; it also helps us map other relevant structure within the surficial aquifer. Development of an accurate velocity model is essential for depth conversion and interpretation of the reflection section. We incorporate information provided by shear-wave seismic methods along with cone penetrometer testing and seismic cone penetrometer testing measurements. One velocity model is based on reflected and refracted arrivals and provides reliable velocity estimates for the full depth range of interest when anchored on interface depths determined from cone data and borehole drillers' logs. A second velocity model is based on seismic cone penetrometer testing data that provide higher-resolution ID velocity columns with error estimates within the depth range of the cone penetrometer testing. Comparison of the reflection/refraction model with the seismic cone penetrometer testing model also suggests that the mass of the cone truck can influence velocity with the equivalent effect of approximately one metre of extra overburden stress. Together, these velocity models and the depth-converted reflection section result in a better constrained hydrologic model of the subsurface and illustrate the pivotal role that cone data can provide in the reflection processing workflow. ?? 2009 European Association of Geoscientists & Engineers.

  1. Assessing mechanical properties from cone indentation hardness

    NASA Astrophysics Data System (ADS)

    Dicarlo, Anthony Albert

    This dissertation investigates methods for assessing the mechanical properties of materials using hardness values obtained from cone indentations. A broad range of isotropic metallic materials was simulated using finite element analysis. In particular, the elastic and plastic bulk properties, which define the stress-strain behavior of materials that exhibit power law hardening, are studied. Other investigators have found that the Young's modulus, E, can be determined from the unloading data of a cone indentation. Therefore, the remaining properties of interest, in this study, are the yield strength, Y, and the work hardening exponent, n. Atkins and Tabor have conducted pioneering work in the area of determining the stress-strain behavior of a metallic material from cone indentation experiments. This work has been re-visited in this study using computational models implementing an expanded range of mechanical properties. Consequently, discrepancies in this prediction method were uncovered when the mechanical properties were outside of the original range studied. As a result, two new prediction methods have been developed using the data collected from the finite element simulations in conjunction with a regression technique. The first method correlates the non-dimensional hardness values, H/E, collected from five cone indentations to the non-dimensional mechanical properties, Y/E and n. The second method is similar in principle, but uses two hardness values as opposed to five. The yield strength can be estimated with a priori knowledge of E. Both of these methods are compared to the method developed by Atkins and Tabor. Although the majority of the work mentioned is focused on the macro-scale, bulk mechanical properties, there is some investigation of meso-scale cone indentations. At the meso-scale, the number of geometric dislocations is significant enough to noticeably increase the strength of a material. This length scale effect is studied for various angled cone

  2. Aerosol penetration through filtering facepieces and respirator cartridges.

    PubMed

    Chen, C C; Lehtimäki, M; Willeke, K

    1992-09-01

    Air-purifying respirators must be certified following the National Institute for Occupational Safety and Health (NIOSH) filter test criteria (30 CFR 11). The criteria specify a range for the mean particle size and the measure of spread permissible for the test aerosol. The authors' experiments have shown that aerosol penetration as a function of particle size differs considerably among certified respirators of the same type. Filtering facepieces (disposable respirators) and cartridges of the dust-mist, dust-mist-fume, and high-efficiency particulate air type were tested. The respirators were sealed to mannequins in a test chamber. The aerosol concentrations inside and outside the respirator were measured by an aerodynamic particle sizer and a laser aerosol spectrometer over a particle size range of 0.1 to 15 microns. Five flow rates ranging from 5 to 100 L/min were used to study flow dependency. The aerosol penetration through the filters is presented as a function of particle size. Aerosol penetration and pressure drop are combined to express the performance of each filter in terms of "quality factor." Under the same test conditions, the quality factor of one respirator may be as much as 6.6 times more than that of another respirator of the same type. The filter quality factor has a greater aerosol size dependency as airflow and aerosol size increase. In general, cartridges have a larger surface area than filtering facepieces but not necessarily lower filter penetration or higher filter quality.(ABSTRACT TRUNCATED AT 250 WORDS)

  3. Understanding Cone Photoreceptor Cell Death in Achromatopsia.

    PubMed

    Carvalho, Livia S; Vandenberghe, Luk H

    2016-01-01

    Colour vision is only achieved in the presence of healthy and functional cone photoreceptors found in the retina. It is an essential component of human vision and usually the first complaint patients undergoing vision degeneration have is the loss of daylight colour vision. Therefore, an understanding of the biology and basic mechanisms behind cone death under the degenerative state of retinal dystrophies and how the activation of the apoptotic pathway is triggered will provide valuable knowledge. It will also have broader applications for a spectrum of visual disorders and will be critical for future advances in translational research.

  4. Electric-field magnitudes of whistler-mode waves near the resonance cone

    NASA Astrophysics Data System (ADS)

    James, G.

    The theory of dipole-antenna radiation in a magnetoplasma has been tested through the analysis of the data from the two-point propagation experiment OEDIPUS C (OC). One of the first phenomena to attract attention was whistler-mode propagation near the lower oblique resonance at 25 kHz. Signal strengths of waves propagating near the resonance cone were considerably stronger than those inside the cone. Those signal strengths have been explained using a new application of the reciprocity principle to estimate the receiving dipole's effective length, which is found to be much larger than its physical length. Recently, data analysis uncovered the same enhancement of resonance-cone signals around 100 kHz. Evidence of the linear polarization of the wave electric field was obtained from both the 25- and 100-kHz data. The magnitudes of dipole effective lengths deduced from the OC observations cast a new light on past investigations of phenomena involving whistler-mode propagation near the resonance cone. One example is tests of the theory for auroral-hiss generation. In these tests, theoretical electric-field magnitudes were compared with values inferred from receiving dipole voltages when the dipole was assumed to have an effective length equal to its physical length, L. The ratio of the observed to theoretical field strengths was about 20 dB, which led to the conclusion that the test-particle theory was not applicable. It now appears that the observed fields were overestimated because of the incorrect effective-length assumption. There are other instances of perceived magnitudes of electric fields of waves propagating near the lower- or upper-oblique resonance cone. Two-point active propagation experiments using the ISIS topside sounders during rendezvous produced observations of strong, highly dispersed pulses that appeared to carry an unusually large total energy. These results signal a need for caution in the interpretation of signal levels of resonance-cone

  5. Development of topographic asymmetry: Insights from dated cinder cones in the western United States

    NASA Astrophysics Data System (ADS)

    McGuire, Luke A.; Pelletier, Jon D.; Roering, Joshua J.

    2014-08-01

    Topographic asymmetry, that is, differences in the morphology of landscapes as a function of slope aspect, can be used to infer ecohydrogeomorphic feedback relationships. In this study, we document the dependence of topographic gradients and drainage densities on slope aspect and time/age in four Quaternary cinder cone fields in Arizona, Oregon, and California. Cinder cones are particularly useful as natural experiments in geomorphic evolution because they begin their evolution at a known time in the past (many have been radiometrically dated) and because they often have simple, well-constrained initial morphologies. North-facing portions of cinder cones have steeper topographic gradients and higher mean vegetation cover (i.e., Normalized Difference Vegetation Index, or NDVI, values) under current climatic conditions compared with corresponding south-facing portions of cones within each volcanic field. Drainage density is also higher on north-facing portions of cones in three of the four volcanic fields. These differences in topography were not present initially but developed progressively over time, indicating that the asymmetry is a result of post-eruption geomorphic processes. To test alternative hypotheses for the slope-aspect control of topography, we developed a numerical model for cinder cone evolution and a methodology for estimating local paleovegetation cover as a function of elevation, slope aspect, and time within the Quaternary. The numerical model results demonstrate that rates of colluvial transport were higher on south-facing hillslopes in at least three of the four cinder cones fields. Our paleovegetation analysis suggests that in the two Arizona volcanic fields we studied, higher rates of colluvial transport on south-facing hillslopes were the result of greater time-averaged vegetation cover and hence higher rates of sediment transport by floral bioturbation. Our results illustrate the profound impact that relatively small variations in solar

  6. Attenuation of S-cone function at high altitude assessed by electroretinography.

    PubMed

    Schatz, Andreas; Dominik Fischer, M; Schommer, Kai; Zrenner, Eberhart; Bartz-Schmidt, Karl-Ulrich; Gekeler, Florian; Willmann, Gabriel

    2014-04-01

    As impaired S-cone function has been reported psychophysically this study assessed S-cone function during high altitude exposure using electroretinography (ERG) and investigated a possible association with severity of acute mountain sickness (AMS). This work is related to the Tübingen High Altitude Ophthalmology (THAO) study. Standard ERG equipment was used (Diagnosys LLC, Cambridge, UK) with special protocol settings to extract S-cone function. Twelve subjects were analyzed in the current study and examinations were performed in Tübingen, Germany (341m) as baseline and thereafter at the Capanna Margherita, Italy (4559m) at high altitude. Results were compared using a paired t-test. Correlations between ERG measurements and oxygen saturation (SpO2), heart rate (HR) and scores of acute mountain sickness (AMS-C and LL) were calculated using Pearson's correlation coefficients. Amplitudes of S-cone b-waves decreased significantly at high altitude (p=0.02). No significant changes were observed for implicit times of b-waves (p=0.63), a-waves (p=0.75) or for a-wave amplitudes (p=0.78). The incidence of AMS was 50% at high altitude according to AMS-C and LL scores (AMS-C⩾0.7 and LL⩾5). Heart rate increased to 84±10min(-1) and SpO2 decreased to 71.9±5.7% at high altitude. No significant correlation was found between S-cone ERG parameters and SpO2, HR, AMS-C and LL. For the first time our study defines a significant impairment of S-cone function at high altitude time using objective state of the art examination methods. No correlation between the functional impairment of S-cones and levels of AMS was detected.

  7. Submicrometer Hollow Bioglass Cones Deposited by Radio Frequency Magnetron Sputtering: Formation Mechanism, Properties, and Prospective Biomedical Applications.

    PubMed

    Popa, A C; Stan, G E; Besleaga, C; Ion, L; Maraloiu, V A; Tulyaganov, D U; Ferreira, J M F

    2016-02-01

    This work reports on the unprecedented magnetron sputtering deposition of submicrometric hollow cones of bioactive glass at low temperature in the absence of any template or catalyst. The influence of sputtering conditions on the formation and development of bioglass cones was studied. It was shown that larger populations of well-developed cones could be achieved by increasing the argon sputtering pressure. A mechanism describing the growth of bioglass hollow cones is presented, offering the links for process control and reproducibility of the cone features. The composition, structure, and morphology of the as-synthesized hollow cones were investigated by energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), grazing incidence geometry X-ray diffraction (GIXRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM)-selected area electron diffraction (SAED). The in vitro biological performance, assessed by degradation tests (ISO 10993-14) and cytocompatibility assays (ISO 10993-5) in endothelial cell cultures, was excellent. This allied with resorbability and the unique morphological features make the submicrometer hollow cones interesting candidate material devices for focal transitory permeabilization of the blood-brain barrier in the treatment of carcinoma and neurodegenerative disorders.

  8. Results of Aquifer Tests Performed Near R-Area, Savannah River Site

    SciTech Connect

    Hiergesell, R.A.

    2001-01-31

    The aquifer testing described in this report was conducted in response to USEPA comments (WSRC, 1998) on the Rev. 0 R-Reactor Seepage Basins RFI/RI Report (WSRC, 1998a), Appendix G, Groundwater Contaminant Transport Modeling for the R-Reactor Seepage Basins (RRSB)/108-4R Overflow Basin Operable Unit. The R-area regional flow model described in Appendix G of the RFI/RI is based on small-scale and/or indirect measures of hydraulic conductivity, including laboratory tests, slug tests, cone penetration testing (CPT) and lithologic core descriptions. The USEPA proposed and SRS- agreed that large-scale conductivity estimates from multiple well pumping tests would be beneficial for validating the model conductivity field. Overall, the aquifer test results validate the 1998 R-area regional groundwater flow model.

  9. Basaltic Cone Suggests Constructional Origin of Some Guyots.

    PubMed

    Christensen, M N; Gilbert, C M

    1964-01-17

    A basaltic cinder cone was built beneath the waters of Mono Lake in Pleistocene time. This cone is now exposed. Its internal structure, external form, and petrography suggest that it was constructed with a flat top.

  10. FAA Fluorescent Penetrant Activities - An Update

    SciTech Connect

    Moore, D.G.

    1998-10-20

    The Federal Aviation Administration's Airworthiness Assurance NDI Validation Center (AANC) is currently characterizing low cycle fatigue specimens that will support the needs of penetrant manufacturers, commercial airline industry and the Federal Aviation Administration. The main focus of this characterization is to maintain and enhance the evaluation of penetrant inspection materials and apply resources to support the aircraft community needs. This paper discusses efforts to-date to document the Wright Laboratory penetrant evaluation process and characterize penetrant brightness readings in the initial set of sample calibration panels using Type 1 penetrant.

  11. Fiscal year 1976 progress report on a feasibility study evaluating the use of surface penetrators for planetary exploration

    NASA Technical Reports Server (NTRS)

    Blanchard, M. B.; Oberbeck, V. R.; Bunch, T. E.; Reynolds, R. T.; Canning, T. N.; Jackson, R. W.

    1976-01-01

    The feasibility of employing penetrators for exploring Mars was examined. Eight areas of interest for key scientific experiments were identified. These include: seismic activity, imaging, geochemistry, water measurement, heatflow, meteorology, magnetometry, and biochemistry. In seven of the eight potential experiment categories this year's progress included: conceptual design, instrument fabrication, instrument performance evaluation, and shock loading of important components. Most of the components survived deceleration testing with negligible performance changes. Components intended to be placed inside the penetrator forebody were tested up to 3,500 g and components intended to be placed on the afterbody were tested up to 21,000 g. A field test program was conducted using tentative Mars penetrator mission constraints. Drop tests were performed at two selected terrestrial analog sites to determine the range of penetration depths for anticipated common Martian materials. Minimum penetration occurred in basalt at Amboy, California. Three full-scale penetrators penetrated 0.4 to 0.9 m into the basalt after passing through 0.3 to 0.5 m of alluvial overburden. Maximum penetration occurred in unconsolidated sediments at McCook, Nebraska. Two full-scale penetrators penetrated 2.5 to 8.5 m of sediment. Impact occurred in two kinds of sediment: loess and layered clay. Deceleration g loads of nominally 2,000 for the forebody and 20,000 for the afterbody did not present serious design problems for potential experiments. Penetrators have successfully impacted into terrestrial analogs of the probable extremes of potential Martian sites.

  12. Restoration of cone vision in a mouse model of achromatopsia.

    PubMed

    Alexander, John J; Umino, Yumiko; Everhart, Drew; Chang, Bo; Min, Seok H; Li, Qiuhong; Timmers, Adrian M; Hawes, Norman L; Pang, Ji-Jing; Barlow, Robert B; Hauswirth, William W

    2007-06-01

    Loss of cone function in the central retina is a pivotal event in the development of severe vision impairment for many prevalent blinding diseases. Complete achromatopsia is a genetic defect resulting in cone vision loss in 1 in 30,000 individuals. Using adeno-associated virus (AAV) gene therapy, we show that it is possible to target cones and rescue both the cone-mediated electroretinogram response and visual acuity in the Gnat2 ( cpfl3 ) mouse model of achromatopsia.

  13. Effect of Crack Opening on Penetrant Crack Detectability

    NASA Technical Reports Server (NTRS)

    Weaver, Devin

    2009-01-01

    Results: From the testing we were able to determine all the cracks within the test range were detectable or better with developer. Many of the indications after development lost their linearity and gave circular indications. Our tests were performed in a laboratory and our procedure would be difficult in an industrial setting. Conclusions: The "V" did not significantly affect our ability to detect the POD cracks with fluorescent penetrant. Conduct same experiment with more cracks. The 0.025 and 0.050 POD specimens are clean and documented with the SEM. Conduct water-wash fluorescent penetrant test at EAFB. The poppet cracks are tighter than the POD specimen cracks. Flight FCV poppets: 0.01 mils (0.3 microns) Langley fatigue cracked poppets: 0.02 mils (0.5 microns) POD specimen (post 5 mils): 0.05 mils (1.4 microns) We could not detect cracks in Langley fatigue-cracked poppets with fluorescent penetrant. Investigate inability of penetrant to wet the poppet surface.

  14. The extract from hop cones (Humulus lupulus) as a modulator of oxidative stress in blood platelets.

    PubMed

    Olas, Beata; Kolodziejczyk, Joanna; Wachowicz, Barbara; Jędrejek, Dariusz; Stochmal, Anna; Oleszek, Wiesław

    2011-01-01

    The plant Humulus lupulus is known as the raw material of the brewing industry. Hop cones, rich in polyphenolic compounds and acyl phloroglucides, are widely used to preserve beer and to give it a characteristic aroma and flavor. Hop cones have long been used for medicinal purposes. In particular, hop preparations were mainly recommended for the treatment of sleeping disorders. The antioxidative action of hop cones, however, is poorly understood. The aim of our present study was to investigate in vitro changes in human blood platelets induced by peroxynitrite (ONOO(-), the compound of particular importance for vascular thrombosis and inflammatory process) in the presence of hop cone extract (Humulus lupulus). The antioxidative action of the extract was also compared with the properties of a well-characterized antioxidative commercial monomeric polyphenol, resveratrol (3,4',5-trihydroxystilbene) in a model system in vitro. Various biomarkers of oxidative/nitrative stress, such as carbonyl groups, 3-nitrotyrosine and thiobarbituric acid reactive substances (TBARS) were estimated. The 3-nitrotyrosine formation and carbonyl group generation was assessed by the use of a competition ELISA test and ELISA test, respectively. Tested plant extract (12.5-50 µg/ml), like resveratrol, significantly inhibited protein carbonylation and nitration in the blood platelets treated with ONOO(-) (0.1 mM). The extract from hop cones, like resveratrol, also caused a distinct reduction of platelet lipid peroxidation induced by ONOO(-). The present results indicate that the hope cone extract has in vitro protective effects against ONOO(-), such as induced oxidative/nitrative damage to the human platelet proteins and lipids. However, in comparative studies the extract was not found to be a more effective antioxidant than the solution of pure resveratrol.

  15. Low Activation and Fast Inactivation of Transducin in Carp Cones*

    PubMed Central

    Tachibanaki, Shuji; Yonetsu, Shin-Ichi; Fukaya, Satoshi; Koshitani, Yuki; Kawamura, Satoru

    2012-01-01

    Cone photoreceptors show lower light sensitivity and briefer light responses than rod photoreceptors. The light detection signal in these cells is amplified through a phototransduction cascade. The first step of amplification in the cascade is the activation of a GTP-binding protein, transducin (Tr), by light-activated visual pigment (R*). We quantified transducin activation by measuring the binding of GTPγS in purified carp rod and cone membrane preparations with the use of a rapid quench apparatus and found that transducin activation by an R* molecule is ∼5 times less efficient in cones than in rods. Transducin activation terminated in less than 1 s in cones, more quickly than in rods. The rate of GTP hydrolysis in Tr*, and thus the rate of Tr* inactivation, was ∼25 times higher in cones than in rods. This faster inactivation of Tr* ensures briefer light responses in cones. The expression level of RGS9 was found to be ∼20 times higher in cones than in rods, which explains higher GTP hydrolytic activity and, thus, faster Tr* inactivation in cones than in rods. Although carp rods and cones express rod- or cone-versions of visual pigment and transducin, these molecules themselves do not seem to induce the differences significantly in the transducin activation and Tr* inactivation in rods and cones. Instead, the differences seem to be brought about in a rod or cone cell-type specific manner. PMID:23045532

  16. OSM's cone design and installation experience

    SciTech Connect

    Van Dyke, M.W.

    1983-06-29

    The concrete filled steel cone offers an alternative solution in sealing vertical mine shafts. This paper gives the design and installation experiences of the Office of Surface Mining when dealing with abandoned coal mines. This same solution can also be used with other types of shaft closures. 4 figures.

  17. Epigenomic landscapes of retinal rods and cones

    PubMed Central

    Mo, Alisa; Luo, Chongyuan; Davis, Fred P; Mukamel, Eran A; Henry, Gilbert L; Nery, Joseph R; Urich, Mark A; Picard, Serge; Lister, Ryan; Eddy, Sean R; Beer, Michael A; Ecker, Joseph R; Nathans, Jeremy

    2016-01-01

    Rod and cone photoreceptors are highly similar in many respects but they have important functional and molecular differences. Here, we investigate genome-wide patterns of DNA methylation and chromatin accessibility in mouse rods and cones and correlate differences in these features with gene expression, histone marks, transcription factor binding, and DNA sequence motifs. Loss of NR2E3 in rods shifts their epigenomes to a more cone-like state. The data further reveal wide differences in DNA methylation between retinal photoreceptors and brain neurons. Surprisingly, we also find a substantial fraction of DNA hypo-methylated regions in adult rods that are not in active chromatin. Many of these regions exhibit hallmarks of regulatory regions that were active earlier in neuronal development, suggesting that these regions could remain undermethylated due to the highly compact chromatin in mature rods. This work defines the epigenomic landscapes of rods and cones, revealing features relevant to photoreceptor development and function. DOI: http://dx.doi.org/10.7554/eLife.11613.001 PMID:26949250

  18. Programming Retinal Stem Cells into Cone Photoreceptors

    DTIC Science & Technology

    2015-12-01

    this grant, we sought to investigate the mechanisms that regulate the earliest events in cone photoreceptor development and to exploit this knowledge ...identified 236 genes that were differentially expressed (P < 0.01, false discovery rate < 0.25) between DMSO and DAPT conditions at times that preceded

  19. Novel pharmacological targets from Indian cone snails.

    PubMed

    Ramasamy, M Santhana; Manikandan, S

    2011-02-01

    The oceans are a source of combinatorial library of unique natural products, 'not found in the terrestrial environment'. Marine invertebrates such as sponges, molluscs, bryozoans, tunicates (Urochordata) and their associated microorganisms are the major representatives of promising bioactive compounds. Among these, the predatory molluscan cone snails have evolved with highly structured small and complex array of peptides (more than 50,000) linked to their prey capture and defence. These peptides have become a valuable source of neuro pharmacological targets as many of them selectively modulate ion channels and transporters. A group of scientists from United States, Europe, Australia, Israel and China have been characterized drugs for neuropathic pain and pharmacological targets from the peptides of a few cone snail species. Several are now in Clinical and preclinical development. Less than 1% of the cono peptides are pharmacologically characterized. India has a diversity of 20-30% of total cone snail species distributed worldwide. A group of Indian Scientists have made promising drug discovery programs from Conus peptides. This review will focus on the Conus peptides from Indian cone snails species, their neuro pharmacological targets and future directions.

  20. AAV-mediated cone rescue in a naturally occurring mouse model of CNGA3-achromatopsia.

    PubMed

    Pang, Ji-jing; Deng, Wen-Tao; Dai, Xufeng; Lei, Bo; Everhart, Drew; Umino, Yumiko; Li, Jie; Zhang, Keqing; Mao, Song; Boye, Sanford L; Liu, Li; Chiodo, Vince A; Liu, Xuan; Shi, Wei; Tao, Ye; Chang, Bo; Hauswirth, William W

    2012-01-01

    Achromatopsia is a rare autosomal recessive disorder which shows color blindness, severely impaired visual acuity, and extreme sensitivity to bright light. Mutations in the alpha subunits of the cone cyclic nucleotide-gated channels (CNGA3) are responsible for about 1/4 of achromatopsia in the U.S. and Europe. Here, we test whether gene replacement therapy using an AAV5 vector could restore cone-mediated function and arrest cone degeneration in the cpfl5 mouse, a naturally occurring mouse model of achromatopsia with a CNGA3 mutation. We show that gene therapy leads to significant rescue of cone-mediated ERGs, normal visual acuities and contrast sensitivities. Normal expression and outer segment localization of both M- and S-opsins were maintained in treated retinas. The therapeutic effect of treatment lasted for at least 5 months post-injection. This study is the first demonstration of substantial, relatively long-term restoration of cone-mediated light responsiveness and visual behavior in a naturally occurring mouse model of CNGA3 achromatopsia. The results provide the foundation for development of an AAV5-based gene therapy trial for human CNGA3 achromatopsia.

  1. Reionization on large scales. IV. Predictions for the 21 cm signal incorporating the light cone effect

    SciTech Connect

    La Plante, P.; Battaglia, N.; Natarajan, A.; Peterson, J. B.; Trac, H.; Cen, R.; Loeb, A.

    2014-07-01

    We present predictions for the 21 cm brightness temperature power spectrum during the Epoch of Reionization (EoR). We discuss the implications of the 'light cone' effect, which incorporates evolution of the neutral hydrogen fraction and 21 cm brightness temperature along the line of sight. Using a novel method calibrated against radiation-hydrodynamic simulations, we model the neutral hydrogen density field and 21 cm signal in large volumes (L = 2 Gpc h {sup –1}). The inclusion of the light cone effect leads to a relative decrease of about 50% in the 21 cm power spectrum on all scales. We also find that the effect is more prominent at the midpoint of reionization and later. The light cone effect can also introduce an anisotropy along the line of sight. By decomposing the 3D power spectrum into components perpendicular to and along the line of sight, we find that in our fiducial reionization model, there is no significant anisotropy. However, parallel modes can contribute up to 40% more power for shorter reionization scenarios. The scales on which the light cone effect is relevant are comparable to scales where one measures the baryon acoustic oscillation. We argue that due to its large comoving scale and introduction of anisotropy, the light cone effect is important when considering redshift space distortions and future application to the Alcock-Paczyński test for the determination of cosmological parameters.

  2. Auto calibration of a cone-beam-CT

    SciTech Connect

    Gross, Daniel; Heil, Ulrich; Schulze, Ralf; Schoemer, Elmar; Schwanecke, Ulrich

    2012-10-15

    Purpose: This paper introduces a novel autocalibration method for cone-beam-CTs (CBCT) or flat-panel CTs, assuming a perfect rotation. The method is based on ellipse-fitting. Autocalibration refers to accurate recovery of the geometric alignment of a CBCT device from projection images alone, without any manual measurements. Methods: The authors use test objects containing small arbitrarily positioned radio-opaque markers. No information regarding the relative positions of the markers is used. In practice, the authors use three to eight metal ball bearings (diameter of 1 mm), e.g., positioned roughly in a vertical line such that their projection image curves on the detector preferably form large ellipses over the circular orbit. From this ellipse-to-curve mapping and also from its inversion the authors derive an explicit formula. Nonlinear optimization based on this mapping enables them to determine the six relevant parameters of the system up to the device rotation angle, which is sufficient to define the geometry of a CBCT-machine assuming a perfect rotational movement. These parameters also include out-of-plane rotations. The authors evaluate their method by simulation based on data used in two similar approaches [L. Smekal, M. Kachelriess, S. E, and K. Wa, 'Geometric misalignment and calibration in cone-beam tomography,' Med. Phys. 31(12), 3242-3266 (2004); K. Yang, A. L. C. Kwan, D. F. Miller, and J. M. Boone, 'A geometric calibration method for cone beam CT systems,' Med. Phys. 33(6), 1695-1706 (2006)]. This allows a direct comparison of accuracy. Furthermore, the authors present real-world 3D reconstructions of a dry human spine segment and an electronic device. The reconstructions were computed from projections taken with a commercial dental CBCT device having two different focus-to-detector distances that were both calibrated with their method. The authors compare their reconstruction with a reconstruction computed by the manufacturer of the CBCT device to

  3. Jet penetration of high explosive

    SciTech Connect

    Poulsen, P

    1999-08-11

    It is found that a transition between two flow patterns takes place in thick HE targets. In this case, the jet will initially propagate into the HE at the same rate as into an inert material of the same density. The part of the jet that has stagnated and is flowing nearly co-axially with the incoming jet (but at a much lower speed) is being forced toward the surface of the incoming jet by the pressure of the reaction products but has not as yet made contact. After it makes contact, both axial and perpendicular momentum transfer takes place between the two jet components. After this transition, a new steady state will develop for the propagating jet, with the unperturbed front of the jet propagating at a slower rate than previously. The perturbed front of the jet is still propagating at or near the original rate, having had relatively little axial momentum exchange. However, it has acquired radial momentum and is spreading out as it is propagating; it is therefore becoming less capable of penetrating downstream targets. It is the unperturbed part of the jet that is capable of penetrating downstream targets. A calculational method for predicting this case is presented in this report.

  4. Field studies of beach cones as coastal erosion control/reversal devices for areas with significant oil and gas activities. Annual report, February 24, 1993--February 23, 1994

    SciTech Connect

    Law, V.J.

    1994-07-07

    The primary objective of this project was to evaluate the utility of a device called the ``beach cone`` in combating coastal erosion. Seven initial sites were selected for testing beach cones in a variety of geometric configurations, and six sites were actually used. Six hundred beach cones were installed at the six sites in late July and early August, 1992. An additional 109 cones were installed at an eighth site in December of 1992. Findings indicate that beach cones accreted significant amounts of materials along the beach of a barrier island. At the eighth installation the amount of accreted material was measured by surveys to be 2200 cubic meters (2900 cubic yards) in February of 1993, when the cones were found to have been completely covered by the material. The average increase in elevation was about 7 inches (0. 18 in) with a maximum buildup of 3 ft. (I in). At other test sites, accretion rates have been less dramatic but importantly, no significant additional erosion has occurred, which is a positive result. The cost of sediment accretion using beach cones was found to be about $13.72 per cubic yard of sand or approximately $500,000 per mile of beach, which would be much lower if the cones were mass produced. The survival of the cones through the fringes of Hurricane Andrew indicates that they can be anchored sufficiently to survive significant storms. The measurements of the cones settling rates indicate that this effect is negligible, does not hinder their effectiveness. We do not yet have sufficient data to state the categorical success of the beach cones, but results to date are encouraging.

  5. Validated models for predicting skin penetration from different vehicles.

    PubMed

    Ghafourian, Taravat; Samaras, Eleftherios G; Brooks, James D; Riviere, Jim E

    2010-12-23

    The permeability of a penetrant though skin is controlled by the properties of the penetrants and the mixture components, which in turn relates to the molecular structures. Despite the well-investigated models for compound permeation through skin, the effect of vehicles and mixture components has not received much attention. The aim of this Quantitative Structure Activity Relationship (QSAR) study was to develop a statistically validated model for the prediction of skin permeability coefficients of compounds dissolved in different vehicles. Furthermore, the model can help with the elucidation of the mechanisms involved in the permeation process. With this goal in mind, the skin permeability of four different penetrants each blended in 24 different solvent mixtures were determined from diffusion cell studies using porcine skin. The resulting 96 kp values were combined with a previous dataset of 288 kp data for QSAR analysis. Stepwise regression analysis was used for the selection of the most significant molecular descriptors and development of several regression models. The selected QSAR employed two penetrant descriptors of Wiener topological index and total lipole moment, boiling point of the solvent and the difference between the melting point of the penetrant and the melting point of the solvent. The QSAR was validated internally, using a leave-many-out procedure, giving a mean absolute error of 0.454 for the logkp value of the test set.

  6. PENETRATION OF COAL SLAGS INTO HIGH-CHROMIA REFRACTORIES

    SciTech Connect

    Longanbach, Sara C.; Matyas, Josef; Sundaram, S. K.

    2009-10-05

    Slagging coal gasifiers are used for the production of electricity and synthetic gases, as well as chemicals. High temperatures in the reaction chamber, typically between 1250ºC and 1600ºC, high pressure, generally greater than 400 psi, and corrosive slag place severe demands on the refractory materials. Slag produced during the combustion of coal flows over the refractory surface and penetrates the porous material. Slag penetration is typically followed by spalling of a brick that significantly decreases the service life of gasifier refractories. Laboratory tests were conducted to determine the penetration depth of slags into high-chromia refractories as a function of time and temperature for various refractory-slag combinations.

  7. Experiments and Simulations of Penetration into Granite by an Aluminum Shaped Charge

    SciTech Connect

    Murphy, M J; Randers-Pehrson, G; Kuklo, R M; Rambur, T A; Switzer, L L; Summes, M A

    2003-07-27

    This paper describes experimental results and numerical simulations of jet penetration into granite from an aluminum lined shaped charge. Several penetration versus standoff experiments were conducted into an in-situ granite formation located in the Climax Ridge region of the Nevada Test Site. Simulations of the jet penetration were modeled with a two dimensional arbitrary lagrange eulerian hydrocode. The effects of variations in the granite flow stress, porosity, and EOS have been evaluated. The work described in this paper is a continuation of our studies on jet penetration and modeling into high strength concrete.

  8. Perturbation theory in light-cone quantization

    SciTech Connect

    Langnau, A.

    1992-01-01

    A thorough investigation of light-cone properties which are characteristic for higher dimensions is very important. The easiest way of addressing these issues is by analyzing the perturbative structure of light-cone field theories first. Perturbative studies cannot be substituted for an analysis of problems related to a nonperturbative approach. However, in order to lay down groundwork for upcoming nonperturbative studies, it is indispensable to validate the renormalization methods at the perturbative level, i.e., to gain control over the perturbative treatment first. A clear understanding of divergences in perturbation theory, as well as their numerical treatment, is a necessary first step towards formulating such a program. The first objective of this dissertation is to clarify this issue, at least in second and fourth-order in perturbation theory. The work in this dissertation can provide guidance for the choice of counterterms in Discrete Light-Cone Quantization or the Tamm-Dancoff approach. A second objective of this work is the study of light-cone perturbation theory as a competitive tool for conducting perturbative Feynman diagram calculations. Feynman perturbation theory has become the most practical tool for computing cross sections in high energy physics and other physical properties of field theory. Although this standard covariant method has been applied to a great range of problems, computations beyond one-loop corrections are very difficult. Because of the algebraic complexity of the Feynman calculations in higher-order perturbation theory, it is desirable to automatize Feynman diagram calculations so that algebraic manipulation programs can carry out almost the entire calculation. This thesis presents a step in this direction. The technique we are elaborating on here is known as light-cone perturbation theory.

  9. Discretized light-cone quantization: e sup + e minus (. gamma. ) model for positronium

    SciTech Connect

    Kaluza, M. Center for Applied Mathematics and Theoretical Physics, University of Maribor, Krekova 2, YU-62000 Maribor, Slovenia ); Pauli, H.C. )

    1992-04-15

    The method of discretized light-cone quantization is applied to gauge theory in 3+1 dimensions and tested by calculating the spectrum and the wave functions for positronium. Working in a Fock-space expansion, only the electron-positron and the electron-positron-photon states are included. The light-cone Hamiltonian matrix is constructed blockwise, and diagonalized using the Bauer-Rutishauser simultaneous iteration algorithm for sparse matrices. At the current level of accuracy of about 10%, the model reproduces the binding energy and the charge radius of the positronium ground state for the coupling constant of {alpha}=0.3. The distribution functions for fermions and photons are presented for the ground state. In addition the light-cone Schroedinger equation has been solved.

  10. Rod-cone interactions and the temporal impulse response of the cone pathway

    PubMed Central

    Zele, Andrew J.; Cao, Dingcai; Pokorny, Joel

    2008-01-01

    Dark-adapted rods suppress cone-mediated flicker detection. This study evaluates the effect that rod activity has on cone temporal processing by investigating whether rod mediated suppression changes the cone pathway impulse response function, regardless of the form of the temporal signal. Stimuli were generated with a 2-channel photostimulator that has four primaries for the central field and four primaries for the surround. Cone pathway temporal impulse response functions were derived from temporal contrast sensitivity data with periodic stimuli, and from two-pulse discrimination data in which pairs of briefly pulsed stimuli were presented successively at a series of stimulus onset asynchronies. Dark-adapted rods altered the amplitude and timing of cone pathway temporal impulse response functions, irrespective of whether they were derived from measurements with temporally periodic stimuli or in a brief presentation temporal resolution task with pulsed stimuli. Rod-cone interactions are a fundamental operation in visual temporal processing under mesopic light levels, acting to decrease the temporal bandwidth of the visual system. PMID:18486960

  11. Estimation of penetrance from twin data.

    PubMed

    Praxedes, L A; Otto, P A

    2000-12-01

    A simple method for estimating the gene frequency p and the penetrance value K from data on polymorphic monogenic characteristics on monozygotic twin pairs is presented. In spite of the method here presented having limited value because the results it yields cannot be evaluated on their own, the estimates of p and K it provides can be indirectly tested by comparing them to the ones obtained in familial aggregates through classical segregation analysis or by using the latter to calculate the expected proportions of dominant-dominant, dominant-recessive and recessive-recessive monozygotic twin pairs. When the method is applied to data on tongue-rolling ability published in the literature, a good agreement is observed between twin and familial estimates, thus indicating that the method is reliable and that it can be used as an ancillary way of corroborating or otherwise evidence of monogenic autosomal dominant mechanism inferred from the analysis of familial data.

  12. Noncationic Rigid and Anisotropic Coiled-Coil Proteins Exhibit Cell-Penetration Activity.

    PubMed

    Nakayama, Norihisa; Hagiwara, Kyoji; Ito, Yoshihiro; Ijiro, Kuniharu; Osada, Yoshihito; Sano, Ken-ichi

    2015-08-04

    Numerous cationic peptides that penetrate cells have been studied intensively as drug delivery system carriers for cellular delivery. However, cationic molecules tend to be cytotoxic and cause inflammation, and their stability in the blood is usually low. We have previously demonstrated that a rigid and fibrous cationic coiled-coil protein exhibited cell-penetrating ability superior to that of previously reported cell-penetrating peptides. Making use of structural properties, here we describe the cell-penetrating activity of a rigid and fibrous coiled-coil protein with a noncationic surface. A fibrous coiled-coil protein of pI 6.5 penetrated 100% of the cells tested in vitro at a concentration of 500 nM, which is comparable to that of previously reported cell-penetrating peptides. We also investigated the effect of cell-strain dependency and short-term cytotoxicity.

  13. Study of high-strength CFRP bolted joints with failure-monitoring cone washers

    NASA Astrophysics Data System (ADS)

    Katsumata, Tsukasa; Mizutani, Yoshihiro; Todoroki, Akira; Matsuzaki, Ryosuke

    2011-09-01

    To increase the strength of carbon-fiber-reinforced plastic (CFRP) bolted joints, a method to increase the friction force between carbon-fiber-reinforced plastic members was proposed. The increase in failure load for the proposed joint was confirmed in finite-element method analyses and joint tests. Additionally, the feasibility of damage monitoring using surface strains of the cone washer was demonstrated.

  14. Benign Prostatic Hyperplasia: Cone-Beam CT in Conjunction with DSA for Identifying Prostatic Arterial Anatomy.

    PubMed

    Wang, Mao Qiang; Duan, Feng; Yuan, Kai; Zhang, Guo Dong; Yan, Jieyu; Wang, Yan

    2017-01-01

    Purpose To describe findings in prostatic arteries (PAs) at digital subtraction angiography (DSA) and cone-beam computed tomography (CT) that allow identification of benign prostatic hyperplasia and to determine the value added with the use of cone-beam CT. Materials and Methods This retrospective single-institution study was approved by the institutional review board, and the requirement for written informed consent was waived. From February 2009 to December 2014, a total of 148 patients (mean age ± standard deviation, 70.5 years ± 14.5) underwent DSA of the internal iliac arteries and cone-beam CT with a flat-detector angiographic system before they underwent prostate artery embolization. Both the DSA and cone-beam CT images were evaluated by two interventional radiologists to determine the number of independent PAs and their origins and anastomoses with adjacent arteries. The exact McNemar test was used to compare the detection rate of the PAs and the anastomoses with DSA and with cone-beam CT. Results The PA anatomy was evaluated successfully by means of cone-beam CT in conjunction with DSA in all patients. Of the 296 pelvic sides, 274 (92.6%) had only one PA. The most frequent PA origin was the common gluteal-pudendal trunk with the superior vesicular artery in 118 (37.1%), followed by the anterior division of the internal iliac artery in 99 (31.1%), and the internal pudendal artery in 77 (24.2%) pelvic sides. In 67 (22.6%) pelvic sides, anastomoses to adjacent arteries were documented. The numbers of PA origins and anastomoses, respectively, that could be identified were significantly higher with cone-beam CT (301 of 318 [94.7%] and 65 of 67 [97.0%]) than with DSA (237 [74.5%] and 39 [58.2%], P < .05). Cone-beam CT provided essential information that was not available with DSA in 90 of 148 (60.8%) patients. Conclusion Cone-beam CT is a useful adjunctive technique to DSA for identification of the PA anatomy and provides information to help treatment planning

  15. An electrochemical modeling of lithium-ion battery nail penetration

    NASA Astrophysics Data System (ADS)

    Chiu, Kuan-Cheng; Lin, Chi-Hao; Yeh, Sheng-Fa; Lin, Yu-Han; Chen, Kuo-Ching

    2014-04-01

    Nail penetration into a battery pack, resulting in a state of short-circuit and thus burning, is likely to occur in electric car collisions. To demonstrate the behavior of a specific battery when subject to such incidents, a standard nail penetration test is usually performed; however, conducting such an experiment is money consuming. The purpose of this study is to propose a numerical electrochemical model that can simulate the test accurately. This simulation makes two accurate predictions. First, we are able to model short-circuited lithium-ion batteries (LIBs) via electrochemical governing equations so that the mass and charge transfer effect could be considered. Second, the temperature variation of the cell during and after nail penetration is accurately predicted with the help of simulating the temperature distribution of thermal runaway cells by thermal abuse equations. According to this nail penetration model, both the onset of battery thermal runaway and the cell temperature profile of the test are obtained, both of which are well fitted with our experimental results.

  16. Seismic-reflection and ground penetrating radar for environmental site characterization. 1998 annual progress report

    SciTech Connect

    Steeples, D.W.; Plumb, R.

    1998-06-01

    'The project''s goals are threefold: (1) to examine the complementary site-characterization capabilities of modern, three-component shallow-seismic techniques and ground-penetrating radar (GPR) methods at depths ranging from 2 to 8 m at an existing test site; (2) to demonstrate the usefulness of the two methods when used in concert to characterize, in three-dimensions, the cone of depression of a pumping well, which will serve as a proxy site for fluid-flow at an actual, polluted site; and (3) to use the site as an outdoor mesoscale laboratory to validate existing three-dimensional ground-penetrating radar and seismic-reflection computer models developed at the Univ. of Kansas. To do this, useful seismic and GPR data are being collected along the same line(s) and within the same depth range. The principal investigators selected a site in central Kansas as a primary location and, although the site itself is not environmentally sensitive, the location chosen offers particularly useful attributes for this research and will serve as a proxy site for areas that are contaminated. As part of an effort to evaluate the strengths of each method, the authors will repeat the seismic and GPR surveys on a seasonal basis to establish how the complementary information obtained varies over time. Because the water table fluctuates at this site on a seasonal basis, variations in the two types of data over time also can be observed. Such noninvasive in-situ methods of identifying and characterizing the hydrologic flow regimes at contaminated sites support the prospect of developing effective, cost-conscious cleanup strategies in the near future. As of the end of May 1998, the project is on schedule. The first field work was conducted using both of the geophysical survey methods in October of 1997, and the second field survey employed both methods in March of 1998. One of the stated tasks is to reoccupy the same survey line on a quarterly basis for two years to examine change in both

  17. Simulated and empiric wind pollination patterns of conifer ovulate cones

    PubMed Central

    Niklas, Karl J.

    1982-01-01

    Wind tunnel analyses of conifer ovulate cones indicate that the total geometry of the cone enhances the probability of pollen entrapment. Aerodynamic characteristics of cone scale-bract complexes are such that suspended pollen is directed toward the micropyles of attached ovules. Within the taxa examined, there appears to be a preferential entrapment by ovulate cones of pollen of the same species. The data are interpreted as evidence for an aerodynamic reciprocity between wind-suspended pollen and the structure of ovulate cones which increases the frequency of pollination and the potential for fertilization. Images PMID:16593147

  18. Unpaired Dirac cones in photonic lattices and networks (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Chong, Yidong; Leykam, Daniel; Rechtsman, Mikael C.

    2016-09-01

    Unpaired Dirac cones are bandstructures with two bands crossing at a single point in the Brillouin zone. It is known that photonic bandstructures can exhibit pairs of Dirac cones, similar to graphene; unpaired cones, however, have not observed in photonics, and have been observed in condensed-matter systems only among topological insulator surface states. We show that unpaired Dirac cones occur in a 2D photonic lattice that is not the surface of a 3D system. These modes have unusual properties, including conical diffraction and antilocalization immune to short-range disorder, due to the absence of "intervalley" scattering between Dirac cones.

  19. Hydraulic conductivity assessment of slurry wall using piezocone test

    SciTech Connect

    Manassero, M. )

    1994-10-01

    Cone-penetration tests (CPTs) with pore pressure (u) measurement or piezocone tests (CPTUs) are carried out inside a cutoff wall for polluted-groundwater containment. The backfilling material for the cutoff wall is a typical cement-bentonite (CB) self-hardening slurry whose composition is 76.8% water, 19.2% blast furnace cement, and 4% sodium bentonite. A tentative framework for interpretation of CPTUs in terms of hydraulic conductivity (k) is developed. In particular, a continuous assessment of hydraulic conductivity along a vertical profile is attempted by combining the piezocone penetration parameters (i.e., total point resistance (q[sub t]), pore-pressure increment ([Delta]u), and sleeve friction (f[sub s])). The obtained k results are comparable with results from CPTU dissipation tests, in-situ borehole infiltration tests, and laboratory tests performed on the same CB mixture. The test results indicate that the CPTUs are a promising tool for in-situ quality control of cutoff walls in terms of evaluating the actual hydraulic conductivity of the completed cutoff wall and, to some extent, of detecting and locating hydraulic defects that, in many cases, are the main causes of poor in-situ performance.

  20. Prospects for retinal cone-targeted gene therapy.

    PubMed

    Alexander, John J; Hauswirth, William W

    2008-06-01

    Gene therapy strategies that target therapeutic genes to retinal cones are a worthy goal both because cone photoreceptor diseases are severely vision limiting and because many retinal diseases that do not affect cones directly eventually lead to cone loss, the reason for eventual blindness. Human achromatopsia is a genetic disease of cones that renders them nonfunctional but otherwise intact. Thus, animal models of achromatopsia were used in conjunction with adeno-associated virus (AAV) vectors whose serotype efficiently transduces cones and with a promoter that limits transgene expression to cones. In the Gnat2(cpfl3) mouse model of one genetic form of human achromatopsia, we were able to demonstrate recovery of normal cone function and visual acuity after a single subretinal treatment of vector that supplied wild-type Gnat2 protein to cones. This validates the overall strategy of targeting cones using recombinant viral vectors and justifies a more complete examination of animal models of cone disease as a prelude to considering a clinical gene therapy trial.

  1. A lightweight ground penetrating radar

    SciTech Connect

    Koppenjan, S.K.; Allen, C.M.; Gardner, D.; Wong, H.R.

    1998-12-31

    The detection of buried objects, particularly unexploded ordnance (UXO), has gained significant interest in the US in the late 1990s. The desire to remediate the thousands of sites worldwide has become an increasing humanitarian concern. The application of radar to this problem has received renewed attention. Bechtel Nevada, Special Technologies Laboratory (STL) has developed several frequency modulated, continuous wave (FM-CW) ground penetrating radar (GPR) units for the US Department of Energy since 1984. To meet these new technical requirements for high resolution data and UXO detection, STL is moving forward with advances to GPR technology, signal processing, and imaging with the development of an innovative system. The goal is to design and fabricate a lightweight, battery operated unit that does not require surface contact and can be operated by a novice user.

  2. Cable Braid Electromagnetic Penetration Model.

    SciTech Connect

    Warne, Larry K.; Langston, William L.; Basilio, Lorena I.; Johnson, W. A.

    2015-06-01

    The model for penetration of a wire braid is rigorously formulated. Integral formulas are developed from energy principles and reciprocity for both self and transfer immittances in terms of potentials for the fields. The detailed boundary value problem for the wire braid is also setup in a very efficient manner; the braid wires act as sources for the potentials in the form of a sequence of line multipoles with unknown coefficients that are determined by means of conditions arising from the wire surface boundary conditions. Approximations are introduced to relate the local properties of the braid wires to a simplified infinite periodic planar geometry. This is used in a simplified application of reciprocity to be able to treat nonuniform coaxial geometries including eccentric interior coaxial arrangements and an exterior ground plane.

  3. Tissue Penetration of Antifungal Agents

    PubMed Central

    Felton, Timothy; Troke, Peter F.

    2014-01-01

    SUMMARY Understanding the tissue penetration of systemically administered antifungal agents is critical for a proper appreciation of their antifungal efficacy in animals and humans. Both the time course of an antifungal drug and its absolute concentrations within tissues may differ significantly from those observed in the bloodstream. In addition, tissue concentrations must also be interpreted within the context of the pathogenesis of the various invasive fungal infections, which differ significantly. There are major technical obstacles to the estimation of concentrations of antifungal agents in various tissue subcompartments, yet these agents, even those within the same class, may exhibit markedly different tissue distributions. This review explores these issues and provides a summary of tissue concentrations of 11 currently licensed systemic antifungal agents. It also explores the therapeutic implications of their distribution at various sites of infection. PMID:24396137

  4. ENAM Mutations with Incomplete Penetrance

    PubMed Central

    Seymen, F.; Lee, K.-E.; Koruyucu, M.; Gencay, K.; Bayram, M.; Tuna, E.B.; Lee, Z.H.; Kim, J.-W.

    2014-01-01

    Amelogenesis imperfecta (AI) is a genetic disease affecting tooth enamel formation. AI can be an isolated entity or a phenotype of syndromes. To date, more than 10 genes have been associated with various forms of AI. We have identified 2 unrelated Turkish families with hypoplastic AI and performed mutational analysis. Whole-exome sequencing identified 2 novel heterozygous nonsense mutations in the ENAM gene (c.454G>T p.Glu152* in family 1, c.358C>T p.Gln120* in family 2) in the probands. Affected individuals were heterozygous for the mutation in each family. Segregation analysis within each family revealed individuals with incomplete penetrance or extremely mild enamel phenotype, in spite of having the same mutation with the other affected individuals. We believe that these findings will broaden our understanding of the clinical phenotype of AI caused by ENAM mutations. PMID:25143514

  5. Bodily action penetrates affective perception

    PubMed Central

    Rigutti, Sara; Gerbino, Walter

    2016-01-01

    Fantoni & Gerbino (2014) showed that subtle postural shifts associated with reaching can have a strong hedonic impact and affect how actors experience facial expressions of emotion. Using a novel Motor Action Mood Induction Procedure (MAMIP), they found consistent congruency effects in participants who performed a facial emotion identification task after a sequence of visually-guided reaches: a face perceived as neutral in a baseline condition appeared slightly happy after comfortable actions and slightly angry after uncomfortable actions. However, skeptics about the penetrability of perception (Zeimbekis & Raftopoulos, 2015) would consider such evidence insufficient to demonstrate that observer’s internal states induced by action comfort/discomfort affect perception in a top-down fashion. The action-modulated mood might have produced a back-end memory effect capable of affecting post-perceptual and decision processing, but not front-end perception. Here, we present evidence that performing a facial emotion detection (not identification) task after MAMIP exhibits systematic mood-congruent sensitivity changes, rather than response bias changes attributable to cognitive set shifts; i.e., we show that observer’s internal states induced by bodily action can modulate affective perception. The detection threshold for happiness was lower after fifty comfortable than uncomfortable reaches; while the detection threshold for anger was lower after fifty uncomfortable than comfortable reaches. Action valence induced an overall sensitivity improvement in detecting subtle variations of congruent facial expressions (happiness after positive comfortable actions, anger after negative uncomfortable actions), in the absence of significant response bias shifts. Notably, both comfortable and uncomfortable reaches impact sensitivity in an approximately symmetric way relative to a baseline inaction condition. All of these constitute compelling evidence of a genuine top-down effect on

  6. Effect of Spray Cone Angle on Flame Stability in an Annular Gas Turbine Combustor

    NASA Astrophysics Data System (ADS)

    Mishra, R. K.; Kumar, S. Kishore; Chandel, Sunil

    2016-04-01

    Effect of fuel spray cone angle in an aerogas turbine combustor has been studied using computational fluid dynamics (CFD) and full-scale combustor testing. For CFD analysis, a 22.5° sector of an annular combustor is modeled and the governing equations are solved using the eddy dissipation combustion model in ANSYS CFX computational package. The analysis has been carried out at 125 kPa and 303 K inlet conditions for spray cone angles from 60° to 140°. The lean blowout limits are established by studying the behavior of combustion zone during transient engine operation from an initial steady-state condition. The computational study has been followed by testing the practical full-scale annular combustor in an aerothermal test facility. The experimental result is in a good agreement with the computational predictions. The lean blowout fuel-air ratio increases as the spray cone angle is decreased at constant operating pressure and temperature. At higher spray cone angle, the flame and high-temperature zone moves upstream close to atomizer face and a uniform flame is sustained over a wide region causing better flame stability.

  7. Cone beam geometry for small objects in phase contrast tomography

    NASA Astrophysics Data System (ADS)

    Jonas, P.; Louis, A. K.

    2013-09-01

    Phase contrast tomography has developed rapidly within the last ten years. The new method enables the reconstruction of the refraction index in addition to the attenuation coefficient and can therefore be very well applied to samples which are only weakly absorbing. First studies in phase contract tomography were done using synchrotron devices which are modeled by the so-called parallel geometry. Samples studied so far are special foams and fiber materials, see Cloetens et al (1999 App. Phys. Lett. 75 2912-4), which give almost no contrast due to absorption but provide excellent images in phase contrast. Recently tubes were successfully applied to a variety of applications. These laboratory devices no longer fulfil the requirement of a parallel geometry but need to be treated as a fan/cone beam geometry. In this paper we derive a mathematical model for cone beam geometry in phase contrast tomography in two and three dimensions for objects small compared to the two distances of object to detector and x-ray source to object. All approximations needed are analyzed and an efficient reconstruction method providing both phase and absorption in a single step is derived, based on the method by Louis and Maaß (1990 Inverse Problems 6 427-39). The reconstruction method is successfully tested using numerical examples with simulated phantom data.

  8. Skin penetration assessment of less lethal kinetic energy munitions.

    PubMed

    Bir, Cynthia A; Stewart, Shelby J; Wilhelm, Marianne

    2005-11-01

    The development of less-lethal technologies has provided law enforcement personnel with an alternative to lethal force. Although the less lethal projectile was produced to engender non-penetrating wounds, case studies show that there have been a number of reported penetrating injuries ranging from minor to significant in morbidity. The objective of this study was to determine the energy per unit area required to penetrate various regions of the body. Eight unembalmed postmortem human specimens were procured for this testing. Each specimen sustained a maximum of 25 impacts consisting of shots to the anterior and posterior thorax, abdomen, and legs. A 12-gauge, fin-stabilized, rubber rocket round was used as the impactor for all of the conducted tests. The energy density required for 50% risk of penetration varied from 23.99 J/cm2 for the location on the anterior rib (p = 0.000) to 52.74 J/cm2 for the location on the posterior rib (p = 0.001).

  9. k-cones and kirigami metamaterials.

    PubMed

    Seffen, Keith A

    2016-09-01

    We are inspired by the tensile buckling of a thin sheet with a slit to create a foldable planar metamaterial. The buckled shape comprises two pairs of identical e-cones connected to the slit, which we refer to as a k-cone. We approximate this shape as discrete vertices that can be folded out of plane as the slit is pulled apart. We determine their kinematics and we calculate generic shape properties using a simple elastic model of the folded shape. We then show how the folded sheet may be tessellated as a unit cell within a larger sheet, which may be constructed a priori by cutting and folding the latter in a regular way, in order to form a planar kirigami structure with a single degree of freedom.

  10. k-cones and kirigami metamaterials

    NASA Astrophysics Data System (ADS)

    Seffen, Keith A.

    2016-09-01

    We are inspired by the tensile buckling of a thin sheet with a slit to create a foldable planar metamaterial. The buckled shape comprises two pairs of identical e-cones connected to the slit, which we refer to as a k-cone. We approximate this shape as discrete vertices that can be folded out of plane as the slit is pulled apart. We determine their kinematics and we calculate generic shape properties using a simple elastic model of the folded shape. We then show how the folded sheet may be tessellated as a unit cell within a larger sheet, which may be constructed a priori by cutting and folding the latter in a regular way, in order to form a planar kirigami structure with a single degree of freedom.

  11. Using electrostatic modelling to study cone discharges

    NASA Astrophysics Data System (ADS)

    Azizi, W.

    2015-10-01

    Cone discharges, also known as bulking brush discharges, can arise when charged insulating powder accumulates in a heap in silos. They can be an effective ignition source to relatively ignition sensitive powders and therefore represent a possible electrostatic hazard. The current international guidance on control of electrostatic hazards (IEC/TS 60079-32-1 [1]), endorses the usage of electrostatic modelling to estimate the electric field above the powder heap. “Such model calculations should be based on the charge to mass ratio, bulk density and filling rate of the powder, the relative permittivity and resistivity of the bulked powder as well as the silo geometry.” This study shows a practical demonstration of this modelling technique. It also examines whether the shape of the heap affects the strength of the electric field above the powder heap, and thus the likelihood of cone discharges from occurring.

  12. Limonene: attractant kairomone for white pine cone beetles (Coleoptera: Scolytidae) in an eastern white pine seed orchard in western North Carolina.

    PubMed

    Miller, Daniel R

    2007-06-01

    I report on the attraction of the white pine cone beetle, Conophthoru.s coniperda (Schwarz) (Coleoptera: Scolytidae), to traps baited with the host monoterpene limonene in western North Carolina. Both (+)- and (-)-limonene attracted male and female cone beetles to Japanese beetle traps in an eastern white pine, Pinus strobus L., seed orchard near Murphy, NC. Catches of cone beetles were directly proportional to the release rate of (-)-limonene; (+)-limonene was not tested for dose response. Attraction of cone beetles to the pheromone (+/-)-trans-pityol was increased significantly by both enantiomers of limonene. In all experiments, catches of C. coniperda were strongly male biased with no treatment effect on sex ratio. (- )-Limonene had no effect on trap catches of the predator Enoclerus nigripes (Say) to pityol, whereas (+)-limonene interrupted the attraction of E. nigripes to traps baited with pityol. Of six monoterpenes commonly found in white pine cones, only (-)-alpha-pinene elicited attraction of E. nigripes to Japanese beetle traps.

  13. Rod photoreceptors protect from cone degeneration-induced retinal remodeling and restore visual responses in zebrafish

    PubMed Central

    Saade, Carole J.; Alvarez-Delfin, Karen; Fadool, James M.

    2013-01-01

    Humans are largely dependent upon cone-mediated vision. However, death or dysfunction of rods, the predominant photoreceptor subtype, results in secondary loss of cones, remodeling of retinal circuitry and blindness. The changes in circuitry may contribute to the vision deficit and undermine attempts at restoring sight. We exploit zebrafish larvae as a genetic model to specifically characterize changes associated with photoreceptor degenerations in a cone-dominated retina. Photoreceptors form synapses with two types of second order neurons, bipolar cells and horizontal cells. Using cell-specific reporter gene expression and immunolabeling for postsynaptic glutamate receptors, significant remodeling is observed following cone degeneration in the pde6cw59 larval retina but not rod degeneration in the Xops:mCFPq13 line. In adults, rods and cones are present in approximately equal numbers, and in pde6cw59 mutants glutamate receptor expression and synaptic structures in the outer plexiform layer are preserved, and visual responses are gained in these once-blind fish. We propose that the abundance of rods in the adult protects the retina from cone degeneration-induced remodeling. We test this hypothesis by genetically manipulating the number of rods in larvae. We show that an increased number and uniform distribution of rods in lor/tbx2bp22bbtl or six7 morpholino-injected larvae protect from pde6cw59-induced secondary changes. The observations that remodeling is a common consequence of photoreceptor death across species, and that in zebrafish a small number of surviving photoreceptors afford protection from degeneration-induced changes provides a model for systematic analysis of factors that slow or even prevent the secondary deteriorations associated with neural degenerative disease. PMID:23365220

  14. Structural and Function Correlation of Cone Packing Utilizing Adaptive Optics and Microperimetry

    PubMed Central

    Supriya, Dabir; Shwetha, Mangalesh; Kiran Anupama, Kumar; Kummelil Mathew, Kurian; Berendschot, Tos T. J. M.; Schouten, Jan S. A. G.; Bharamshetter, Roopa; Naresh, Yadav K.; Rohit, Shetty; Hegde, Bharath

    2015-01-01

    Aim. To assess the functional aspects of cone mosaic and correlate cone packing with retinal sensitivity utilizing microperimetry in emmetropes at different eccentricities. Methods. Twenty-four healthy volunteers underwent microperimetry (MAIA Centervue, Italy) and assessment of photoreceptors using adaptive optics retinal camera, rtx1 (Imagine Eyes, Orsay, France), at 2 and 3 degrees from the foveal centre in 4 quadrants: superior, inferior, temporal, and nasal. Data was analyzed using SPSS version 17 (IBM). Spearman's correlation tests were used to establish correlation between mean cone packing density and retinal sensitivity at different quadrants. Results. Thirteen females and 11 males (age range 20–40 years) were included. The cone density was found to be significantly different among all quadrants (temporal = 25786.68/mm2 ± 4367.07/mm2, superior = 23009.35/mm2 ± 5415.81/mm2, nasal = 22838.09/mm2 ± 4166.22/mm2, and inferior = 21097.53/mm2 ± 4235.84/mm2). A statistical significance (P < 0.008) was found between orthogonal meridians, that is, temporal, nasal (48624.77/mm2)> superior, inferior (44106.88/mm2). A drop in retinal sensitivity was observed as the eccentricity increased (P < 0.05). It was also found that as cone packing density decreased retinal sensitivity also decreased (P < 0.05) in all quadrants. This was observed at both 2 and 3 degrees. Conclusion. It is of crucial importance to establish normative variations in cone structure-function correlation. This may help in detection of subtle pathology and its early intervention. PMID:26167509

  15. Evaluation of radiosurgery techniques–Cone-based linac radiosurgery vs tomotherapy-based radiosurgery

    SciTech Connect

    Yip, Ho Yin; Mui, Wing Lun A.; Lee, Joseph W.Y.; Fung, Winky Wing Ki; Chan, Jocelyn M.T.; Chiu, G.; Law, Maria Y.Y.

    2013-07-01

    Performances of radiosurgery of intracranial lesions between cone-based Linac system and Tomotherapy-based system were compared in terms of dosimetry and time. Twelve patients with single intracranial lesion treated with cone-based Linac radiosurgery system from 2005 to 2009 were replanned for Tomotherapy-based radiosurgery treatment. The conformity index, homogeneity index (HI), and gradient score index (GSI) of each case was calculated. The Wilcoxon matched-pair test was used to compare the 3 indices between both systems. The cases with regular target (n = 6) and those with irregular target (n = 6) were further analyzed separately. The estimated treatment time between both systems was also compared. Significant differences were found in HI (p = 0.05) and in GSI (p = 0.03) for the whole group. Cone-based radiosurgery was better in GSI whereas Tomotherapy-based radiosurgery was better in HI. Cone-based radiosurgery was better in conformity index (p = 0.03) and GSI (p = 0.03) for regular targets, whereas Tomotherapy-based radiosurgery system performed significantly better in HI (p = 0.03) for irregular targets. The estimated total treatment time for Tomotherapy-based radiosurgery ranged from 24 minutes to 35 minutes, including 15 minutes of pretreatment megavoltage computed tomography (MVCT) and image registration, whereas that for cone-based radiosurgery ranged from 15 minutes for 1 isocenter to 75 minutes for 5 isocenters. As a rule of thumb, Tomotherapy-based radiosurgery system should be the first-line treatment for irregular lesions because of better dose homogeneity and shorter treatment time. Cone-based Linac radiosurgery system should be the treatment of choice for regular targets because of the better dose conformity, rapid dose fall-off, and reasonable treatment time.

  16. Cone beam computed tomography use in orthodontics.

    PubMed

    Nervina, J M

    2012-03-01

    Cone beam computed tomography (CBCT) is widely used by orthodontists to obtain three-dimensional (3-D) images of their patients. This is of value as malocclusion results from discrepancies in three planes of space. This review tracks the use of CBCT in orthodontics, from its validation as an accurate and reliable tool, to its use in diagnosing and treatment planning, and in assessing treatment outcomes in orthodontics.

  17. The resistance to chloride penetration of concrete containing nano-particles for pavement

    NASA Astrophysics Data System (ADS)

    Zhang, Mao-hua; Li, Hui

    2006-03-01

    The resistance to chloride penetration of concrete containing nano-particles (TiO II and SiO II) for pavement is experimentally investigated and compared with that of plain concrete, the concrete containing polypropylene (PP) fibers and the concrete containing both nano-particles and PP fibers. The test results indicate that the addition of nano-particles (TiO II and SiO II) improves the resistance to chloride penetration of concrete. The effectiveness of nano-TiO II in improving the resistance to chloride penetration reduces with increasing content of nano-TiO II, and the similar results can be found for the concrete containing nano-SiO II. The resistance to chloride penetration of concrete containing nano-TiO II is better than that containing the same amount of nano-SiO II. However, the resistance to chloride penetration of concrete containing PP fibers is decreased. The larger the content of PP fibers is, the lower the resistance to chloride penetration of concrete is. For the concrete containing both nano-particles and PP fibers, the resistance to chloride penetration is also reduced and even lower than the concrete only containing the same amount of PP fibers. The relationship between the chloride diffusion coefficient and compressive strength of concrete approaches hyperbola basically, which shows that the resistance to chloride penetration of concrete enhances with increasing compressive strength and proves that compressive strength is an important factor influencing the resistance to chloride penetration of concrete.

  18. Reliable simulation of metal surface penetration by lightning continuing currents

    SciTech Connect

    Zischank, W.; Drumm, F.; Fisher, R.J.; Schnetzer, G.H.; Morris, M.E.

    1995-08-01

    Of specific interest to Sandia National Laboratories is the assessment and reduction of the potential safety threat posed by the penetration of metallic casings of munitions due to the direct attachment of lightning strikes. A program with the ultimate aim of quantifying the fidelity of laboratory test techniques used to simulate the penetration of metallic surfaces by lightning continuing currents has been undertaken. Descriptions of the program methodology, dominant factors found to influence test results, and data obtained so far are given. Based on considerations of fundamental arc phenomenology and on the acquired experimental data, a standard test configuration has been established, which has been demonstrated at two independent laboratories to produce consistent results that are generally corroborative of techniques suggested elsewhere in the lightning literature.

  19. Reconfiguration of broad leaves into cones

    NASA Astrophysics Data System (ADS)

    Miller, Laura

    2013-11-01

    Flexible plants, fungi, and sessile animals are thought to reconfigure in the wind and water to reduce the drag forces that act upon them. Simple mathematical models of a flexible beam immersed in a two-dimensional flow will also exhibit this behavior. What is less understood is how the mechanical properties of a leaf in a three-dimensional flow will passively allow roll up and reduce drag. This presentation will begin by examining how leaves roll up into drag reducing shapes in strong flow. The dynamics of the flow around the leaf of the wild ginger Hexastylis arifolia are described using particle image velocimetry. The flows around the leaves are compared with those of simplified sheets using 3D numerical simulations and physical models. For some reconfiguration shapes, large forces and oscillations due to strong vortex shedding are produced. In the actual leaf, a stable recirculation zone is formed within the wake of the reconfigured cone. In physical and numerical models that reconfigure into cones, a similar recirculation zone is observed with both rigid and flexible tethers. These results suggest that the three-dimensional cone structure in addition to flexibility is significant to both the reduction of vortex-induced vibrations and the forces experienced by the leaf.

  20. Inverted cones and their elastic creases

    NASA Astrophysics Data System (ADS)

    Seffen, Keith A.

    2016-12-01

    We study the elastic inversion of a right circular cone, in particular, the uniform shape of the narrow crease that divides its upright and inverted parts. Our methodology considers a cylindrical shell analogy for simplicity where the crease is the boundary layer deformation. Solution of its governing equation of deformation requires careful crafting of the underlying assumptions and boundary conditions in order to reveal an expression for the crease shape in closed form. We can then define the characteristic width of crease exactly, which is compared to a geometrically nonlinear, large displacement finite element analysis. This width is shown to be accurately predicted for shallow and steep cones, which imparts confidence to our original assumptions. Using the shape of crease, we compute the strain energy stored in the inverted cone, in order to derive an expression for the applied force of inversion by a simple energy method. Again, our predictions match finite element data very well. This study may complement other studies of creases traditionally formed in a less controlled manner, for example, during crumpling of lightweight sheets.

  1. CRALBP supports the mammalian retinal visual cycle and cone vision

    PubMed Central

    Xue, Yunlu; Shen, Susan Q.; Jui, Jonathan; Rupp, Alan C.; Byrne, Leah C.; Hattar, Samer; Flannery, John G.; Corbo, Joseph C.; Kefalov, Vladimir J.

    2015-01-01

    Mutations in the cellular retinaldehyde–binding protein (CRALBP, encoded by RLBP1) can lead to severe cone photoreceptor–mediated vision loss in patients. It is not known how CRALBP supports cone function or how altered CRALBP leads to cone dysfunction. Here, we determined that deletion of Rlbp1 in mice impairs the retinal visual cycle. Mice lacking CRALBP exhibited M-opsin mislocalization, M-cone loss, and impaired cone-driven visual behavior and light responses. Additionally, M-cone dark adaptation was largely suppressed in CRALBP-deficient animals. While rearing CRALBP-deficient mice in the dark prevented the deterioration of cone function, it did not rescue cone dark adaptation. Adeno-associated virus–mediated restoration of CRALBP expression specifically in Müller cells, but not retinal pigment epithelial (RPE) cells, rescued the retinal visual cycle and M-cone sensitivity in knockout mice. Our results identify Müller cell CRALBP as a key component of the retinal visual cycle and demonstrate that this pathway is important for maintaining normal cone–driven vision and accelerating cone dark adaptation. PMID:25607845

  2. Ultrasonic/Sonic Impacting Penetrators

    NASA Technical Reports Server (NTRS)

    Bao, Xiaoqi; Bar-Cohen, Yoseph; Chang, Zensheu; Sherrit, Stewart; Stark, Randall A.

    2008-01-01

    Ultrasonic/sonic impacting penetrators (USIPs) are recent additions to the series of apparatuses based on ultrasonic/sonic drill corers (USDCs). A USIP enables a rod probe to penetrate packed soil or another substance of similar consistency, without need to apply a large axial force that could result in buckling of the probe or in damage to some buried objects. USIPs were conceived for use in probing and analyzing soil to depths of tens of centimeters in the vicinity of buried barrels containing toxic waste, without causing rupture of the barrels. USIPs could also be used for other purposes, including, for example, searching for pipes, barrels, or other hard objects buried in soil; and detecting land mines. USDCs and other apparatuses based on USDCs have been described in numerous previous NASA Tech Briefs articles. The ones reported previously were designed, variously, for boring into, and/or acquiring samples of, rock or other hard, brittle materials of geological interest. To recapitulate: A USDC can be characterized as a lightweight, low-power, piezoelectrically driven jackhammer in which ultrasonic and sonic vibrations are generated and coupled to a tool bit. As shown in the figure, a basic USDC includes a piezoelectric stack, a backing and a horn connected to the stack, a free mass (free in the sense that it can slide axially a short distance between the horn and the shoulder of tool bit), and a tool bit, i.e., probe for USIP. The piezoelectric stack is driven at the resonance frequency of the stack/horn/backing assembly to create ultrasonic vibrations that are mechanically amplified by the horn. To prevent fracture during operation, the piezoelectric stack is held in compression by a bolt. The bouncing of the free mass between the horn and the tool bit at sonic frequencies generates hammering actions to the bit that are more effective for drilling than is the microhammering action of ultrasonic vibrations in ordinary ultrasonic drills. The hammering actions

  3. Residual Foveal Cone Structure in CNGB3-Associated Achromatopsia

    PubMed Central

    Langlo, Christopher S.; Patterson, Emily J.; Higgins, Brian P.; Summerfelt, Phyllis; Razeen, Moataz M.; Erker, Laura R.; Parker, Maria; Collison, Frederick T.; Fishman, Gerald A.; Kay, Christine N.; Zhang, Jing; Weleber, Richard G.; Yang, Paul; Wilson, David J.; Pennesi, Mark E.; Lam, Byron L.; Chiang, John; Chulay, Jeffrey D.; Dubra, Alfredo; Hauswirth, William W.; Carroll, Joseph

    2016-01-01

    Purpose Congenital achromatopsia (ACHM) is an autosomal recessive disorder in which cone function is absent or severely reduced. Gene therapy in animal models of ACHM have shown restoration of cone function, though translation of these results to humans relies, in part, on the presence of viable cone photoreceptors at the time of treatment. Here, we characterized residual cone structure in subjects with CNGB3-associated ACHM. Methods High-resolution imaging (optical coherence tomography [OCT] and adaptive optics scanning light ophthalmoscopy [AOSLO]) was performed in 51 subjects with CNGB3-associated ACHM. Peak cone density and inter-cone spacing at the fovea was measured using split-detection AOSLO. Foveal outer nuclear layer thickness was measured in OCT images, and the integrity of the photoreceptor layer was assessed using a previously published OCT grading scheme. Results Analyzable images of the foveal cones were obtained in 26 of 51 subjects, with nystagmus representing the major obstacle to obtaining high-quality images. Peak foveal cone density ranged from 7,273 to 53,554 cones/mm2, significantly lower than normal (range, 84,733–234,391 cones/mm2), with the remnant cones being either contiguously or sparsely arranged. Peak cone density was correlated with OCT integrity grade; however, there was overlap of the density ranges between OCT grades. Conclusions The degree of residual foveal cone structure varies greatly among subjects with CNGB3-associated ACHM. Such measurements may be useful in estimating the therapeutic potential of a given retina, providing affected individuals and physicians with valuable information to more accurately assess the risk-benefit ratio as they consider enrolling in experimental gene therapy trials. (www.clinicaltrials.gov, NCT01846052.) PMID:27479814

  4. Plume effects on the flow around a blunted cone at hypersonic speeds

    NASA Technical Reports Server (NTRS)

    Atcliffe, P.; Kumar, D.; Stollery, J. L.

    1992-01-01

    Tests at M = 8.2 show that a simulated rocket plume at the base of a blunted cone can cause large areas of separated flow, with dramatic effects on the heat transfer rate distribution. The plume was simulated by solid discs of varying sizes or by an annular jet of gas. Flow over the cone without a plume is fully laminar and attached. Using a large disc, the boundary layer is laminar at separation at the test Reynolds number. Transition occurs along the separated shear layer and the boundary layer quickly becomes turbulent. The reduction in heat transfer associated with a laminar separated region is followed by rising values as transition occurs and the heat transfer rates towards the rear of the cone substantially exceed the values obtained without a plume. With the annular jet or a small disc, separation occurs much further aft, so that heat transfer rates at the front of the cone are comparable with those found without a plume. Downstream of separation the shear layer now remains laminar and the heat transfer rates to the surface are significantly lower than the attached flow values.

  5. Why do seals have cones? Behavioural evidence for colour-blindness in harbour seals.

    PubMed

    Scholtyssek, Christine; Kelber, Almut; Dehnhardt, Guido

    2015-03-01

    All seals and cetaceans have lost at least one of two ancestral cone classes and should therefore be colour-blind. Nevertheless, earlier studies showed that these marine mammals can discriminate colours and a colour vision mechanism has been proposed which contrasts signals from cones and rods. However, these earlier studies underestimated the brightness discrimination abilities of these animals, so that they could have discriminated colours using brightness only. Using a psychophysical discrimination experiment, we showed that a harbour seal can solve a colour discrimination task by means of brightness discrimination alone. Performing a series of experiments in which two harbour seals had to discriminate the brightness of colours, we also found strong evidence for purely scotopic (rod-based) vision at light levels that lead to mesopic (rod-cone-based) vision in other mammals. This finding speaks against rod-cone-based colour vision in harbour seals. To test for colour-blindness, we used a cognitive approach involving a harbour seal trained to use a concept of same and different. We tested this seal with pairs of isoluminant stimuli that were either same or different in colour. If the seal had perceived colour, it would have responded to colour differences between stimuli. However, the seal responded with "same", providing strong evidence for colour-blindness.

  6. FRACTIONAL PENETRATION OF PAINT OVERSPRAY ARRESTORS

    EPA Science Inventory

    The report describes the development of fractional penetration curves for liquid droplet penetration of overspray arrestors for discrete droplet diameters from 0.3 to 10 micrometers. (NOTE: Fine particulates are particles with diameters of 10 micrometers or less.) These data poin...

  7. Social Penetration: A Description, Research, and Evaluation.

    ERIC Educational Resources Information Center

    Allensworth, Nicole J.

    Social penetration has been described by S.W. Littlejohn (1992) as "the process of increasing disclosure and intimacy in a relationship." The phrase "social penetration" originated with I. Altman and D. Taylor, the foremost researchers in this area. From other theories, Altman and Taylor developed a unified theory which…

  8. Parametric study on mass loss of penetrators

    NASA Astrophysics Data System (ADS)

    He, Li-Ling; Chen, Xiao-Wei; He, Xiang

    2010-08-01

    Earth penetration weapon (EPW) is applicable for attacking underground targets protected by reinforced concrete and rocks. With increasing impact velocity, the mass loss/abrasion of penetrator increases, which significantly decreases the penetration efficiency due to the change of nose shape. The abrasion may induce instability of the penetrator, and lead to failure of its structure. A common disadvantage, i.e. dependence on corresponding experimental results, exists in all the available formulae, which limits their ranges of application in estimating the mass loss of penetrator. In this paper, we conduct a parametric study on the mass loss of penetrator, and indicate that the mass loss of penetrator can be determined by seven variables, i.e., the initial impact velocity, initial nose shape, melting heat, shank diameter of projectile and density and strength of target as well as the aggregate hardness of target. Further discussion on factors dominant in the mass abrasion of penetrator are given, which may be helpful for optimizing the target or the projectile for defensive or offensive objectives, respectively.

  9. Penetrating Wounds of Great Vessels

    PubMed Central

    Symbas, P. N.; Kourias, E.; Tyras, D. H.; Hatcher, C. R.

    1974-01-01

    Thirty-six patients with penetrating wounds of the great vessels treated at Grady Memorial Hospital during a 7-year period were reviewed. In more than 50% of the cases, diagnosis of the injury was made at the time of emergency thoracotomy for massive bleeding. In the remaining patients the diagnosis was suspected: 1) when the pulse distal to the vascular injury was absent or weak; 2) when the patient had symptoms and signs of impaired central nervous system perfusion; 3) when the missile had traversed the mediastinum and there was roentgenographic evidence of widening of the mediastinal shadow; or, 4) when a new murmur appeared. In all suspected cases with great vessel injury, the diagnosis was confirmed arteriographically. Arteriography in such patients should be performed to define the type and site of vascular injury so that its repair can be properly planned. Twenty-nine patients recovered from their injury, 6 succumbed as a result of it and 1 required midforearm amputation following repair of a subclavian artery and vein injury. Most of these patients underwent autotransfusion which greatly contributed to their successful outcome. Local temporary shunt was used for protection of the spinal cord and/or brain when impairment of their perfusion was required for the repair of the vascular wounds. ImagesFig. 1.Fig. 3.Fig. 4. PMID:17859862

  10. Stepped frequency ground penetrating radar

    DOEpatents

    Vadnais, Kenneth G.; Bashforth, Michael B.; Lewallen, Tricia S.; Nammath, Sharyn R.

    1994-01-01

    A stepped frequency ground penetrating radar system is described comprising an RF signal generating section capable of producing stepped frequency signals in spaced and equal increments of time and frequency over a preselected bandwidth which serves as a common RF signal source for both a transmit portion and a receive portion of the system. In the transmit portion of the system the signal is processed into in-phase and quadrature signals which are then amplified and then transmitted toward a target. The reflected signals from the target are then received by a receive antenna and mixed with a reference signal from the common RF signal source in a mixer whose output is then fed through a low pass filter. The DC output, after amplification and demodulation, is digitized and converted into a frequency domain signal by a Fast Fourier Transform. A plot of the frequency domain signals from all of the stepped frequencies broadcast toward and received from the target yields information concerning the range (distance) and cross section (size) of the target.

  11. Grepafloxacin: pharmacokinetics and tissue penetration.

    PubMed

    Wise, Richard

    1998-03-01

    Pharmacokinetic and tissue penetration studies of grepafloxacin, a new broad-spectrum fluoroquinolone, show that it has useful properties for the treatment of respiratory tract infections. Grepafloxacin has a volume of distribution that is larger than those of many of the other fluoroquinolones and is concentrated in alveolar macrophages, bronchial mucosa and epithelial lining fluid to a greater extent than are certain other fluoroquinolones. Grepafloxacin concentrations achieved in plasma after a 400-mg oral dose are well in excess of those required to inhibit the respiratory pathogens Staphylococcus aureus, Haemophilus influenzae and Moraxella catarrhalis. Streptococcus pneumoniae is also covered for most of the dosing interval, but at normal dose levels grepafloxacin might not inhibit Enterococcus faecalis. The maximum plasma concentrations and area under the concentration---time curve achieved with grepafloxacin suggest that it will be effective for the treatment of community-acquired pneumonia and acute exacerbations of chronic bronchitis. The pharmacokinetics of fluoroquinolones are among their most useful properties. The aim of this paper is to demonstrate whether the differences between grepafloxacin and the other fluoroquinolones are of therapeutic significance.

  12. Evaluation of filter media for particle number, surface area and mass penetrations.

    PubMed

    Li, Lin; Zuo, Zhili; Japuntich, Daniel A; Pui, David Y H

    2012-07-01

    The National Institute for Occupational Safety and Health (NIOSH) developed a standard for respirator certification under 42 CFR Part 84, using a TSI 8130 automated filter tester with photometers. A recent study showed that photometric detection methods may not be sensitive for measuring engineered nanoparticles. Present NIOSH standards for penetration measurement are mass-based; however, the threshold limit value/permissible exposure limit for an engineered nanoparticle worker exposure is not yet clear. There is lack of standardized filter test development for engineered nanoparticles, and development of a simple nanoparticle filter test is indicated. To better understand the filter performance against engineered nanoparticles and correlations among different tests, initial penetration levels of one fiberglass and two electret filter media were measured using a series of polydisperse and monodisperse aerosol test methods at two different laboratories (University of Minnesota Particle Technology Laboratory and 3M Company). Monodisperse aerosol penetrations were measured by a TSI 8160 using NaCl particles from 20 to 300 nm. Particle penetration curves and overall penetrations were measured by scanning mobility particle sizer (SMPS), condensation particle counter (CPC), nanoparticle surface area monitor (NSAM), and TSI 8130 at two face velocities and three layer thicknesses. Results showed that reproducible, comparable filtration data were achieved between two laboratories, with proper control of test conditions and calibration procedures. For particle penetration curves, the experimental results of monodisperse testing agreed well with polydisperse SMPS measurements. The most penetrating particle sizes (MPPSs) of electret and fiberglass filter media were ~50 and 160 nm, respectively. For overall penetrations, the CPC and NSAM results of polydisperse aerosols were close to the penetration at the corresponding median particle sizes. For each filter type, power

  13. Penetration of aflatoxins through isolated human epidermis

    SciTech Connect

    Riley, R.T.; Kemppainen, B.W.; Norred, W.P.

    1985-01-01

    The purpose of this study was to determine if aflatoxin B1 (AFB1) could penetrate through isolated human epidermis (stratum corneum plus viable epidermis). ( UC)AFB1 (7.5-9.3 micrograms) was applied to the stratum corneum of epidermal disks mounted in Teflon diffusion cells. ( UC)AFB1 penetrated chemically unaltered through the isolated epidermis. Chloroform-extractable radioactivity accounted for 82.5 +/- 3.7% of the total penetrating radioactivity in the receptor fluid of the diffusion cells. The rate of penetration was very slow when experiments were conducted under nonoccluded conditions, but was approximately 40 times greater under conditions of occlusion. Penetration after 46 h was less than 0.05% and 3.41% of the applied dose under nonoccluded and occluded conditions, respectively. Total recovery expressed as a percentage of the applied radioactivity was 98.6 +/- 6.4%.

  14. Restoration of cone vision in the CNGA3-/- mouse model of congenital complete lack of cone photoreceptor function.

    PubMed

    Michalakis, Stylianos; Mühlfriedel, Regine; Tanimoto, Naoyuki; Krishnamoorthy, Vidhyasankar; Koch, Susanne; Fischer, M Dominik; Becirovic, Elvir; Bai, Lin; Huber, Gesine; Beck, Susanne C; Fahl, Edda; Büning, Hildegard; Paquet-Durand, François; Zong, Xiangang; Gollisch, Tim; Biel, Martin; Seeliger, Mathias W

    2010-12-01

    Congenital absence of cone photoreceptor function is associated with strongly impaired daylight vision and loss of color discrimination in human achromatopsia. Here, we introduce viral gene replacement therapy as a potential treatment for this disease in the CNGA3(-/-) mouse model. We show that such therapy can restore cone-specific visual processing in the central nervous system even if cone photoreceptors had been nonfunctional from birth. The restoration of cone vision was assessed at different stages along the visual pathway. Treated CNGA3(-/-) mice were able to generate cone photoreceptor responses and to transfer these signals to bipolar cells. In support, we found morphologically that treated cones expressed regular cyclic nucleotide-gated (CNG) channel complexes and opsins in outer segments, which previously they did not. Moreover, expression of CNGA3 normalized cyclic guanosine monophosphate (cGMP) levels in cones, delayed cone cell death and reduced the inflammatory response of Müller glia cells that is typical of retinal degenerations. Furthermore, ganglion cells from treated, but not from untreated, CNGA3(-/-) mice displayed cone-driven, light-evoked, spiking activity, indicating that signals generated in the outer retina are transmitted to the brain. Finally, we demonstrate that this newly acquired sensory information was translated into cone-mediated, vision-guided behavior.

  15. Three-dimensional computed tomography from interferometric measurements within a narrow cone of views

    NASA Technical Reports Server (NTRS)

    Decker, Arthur J.; Izen, Steven H.

    1991-01-01

    A theory to determine the properties of a fluid from measurements of its projections was developed and tested. Viewing cones as small as 10 degrees were evaluated, with the only assumption being that the property was space limited. The results of applying the theory to numerical and actual interferograms of a spherical discontinuity of refractive index are presented. The theory was developed to test the practicality and limits of using three-dimensional computer tomography in internal fluid dynamics.

  16. APPLICATION OF STEEL PIPE PILE LOADING TESTS TO DESIGN VERIFICATION OF FOUNDATION OF THE TOKYO GATE BRIDGE

    NASA Astrophysics Data System (ADS)

    Saitou, Yutaka; Kikuchi, Yoshiaki; Kusakabe, Osamu; Kiyomiya, Osamu; Yoneyama, Haruo; Kawakami, Taiji

    Steel sheet pipe pile foundations with large diameter steel pipe sheet pile were used for the foundation of the main pier of the Tokyo Gateway bridge. However, as for the large diameter steel pipe pile, the bearing mechanism including a pile tip plugging effect is still unclear due to lack of the practical examinations even though loading tests are performed on Trans-Tokyo Bay Highway. In the light of the foregoing problems, static pile loading tests both vertical and horizontal directions, a dynamic loading test, and cone penetration tests we re conducted for determining proper design parameters of the ground for the foundations. Design parameters were determined rationally based on the tests results. Rational design verification was obtained from this research.

  17. Leak test adapter for containers

    DOEpatents

    Hallett, Brian H.; Hartley, Michael S.

    1996-01-01

    An adapter is provided for facilitating the charging of containers and leak testing penetration areas. The adapter comprises an adapter body and stem which are secured to the container's penetration areas. The container is then pressurized with a tracer gas. Manipulating the adapter stem installs a penetration plug allowing the adapter to be removed and the penetration to be leak tested with a mass spectrometer. Additionally, a method is provided for using the adapter.

  18. Tantalum cones and bone defects in revision total knee arthroplasty.

    PubMed

    Boureau, F; Putman, S; Arnould, A; Dereudre, G; Migaud, H; Pasquier, G

    2015-04-01

    Management of bone loss is a major challenge in revision total knee arthroplasty (TKA). The development of preformed porous tantalum cones offers new possibilities, because they seem to have biological and mechanical qualities that facilitate osseointegration. Compared to the original procedure, when metaphyseal bone defects are too severe, a single tantalum cone may not be enough and we have developed a technique that could extend the indications for this cone in these cases. We used 2 cones to fill femoral bone defects in 7 patients. There were no complications due to wear of the tantalum cones. Radiological follow-up did show any migration or loosening. The short-term results confirm the interest of porous tantalum cones and suggest that they can be an alternative to allografts or megaprostheses in case of massive bone defects.

  19. Pulsar average waveforms and hollow cone beam models

    NASA Technical Reports Server (NTRS)

    Backer, D. C.

    1975-01-01

    An analysis of pulsar average waveforms at radio frequencies from 40 MHz to 15 GHz is presented. The analysis is based on the hypothesis that the observer sees one cut of a hollow-cone beam pattern and that stationary properties of the emission vary over the cone. The distributions of apparent cone widths for different observed forms of the average pulse profiles (single, double/unresolved, double/resolved, triple and multiple) are in modest agreement with a model of a circular hollow-cone beam with random observer-spin axis orientation, a random cone axis-spin axis alignment, and a small range of physical hollow-cone parameters for all objects.

  20. Nonallelic heterogeneity in autosomal dominant retinitis pigmentosa with incomplete penetrance

    SciTech Connect

    Kim, S.K.; Berson, E.L.; Dryja, T.P.

    1994-08-01

    Retinitis pigmentosa is a group of retinal diseases in which photoreceptor cells throughout the retina degenerate. Although there is considerable genetic heterogeneity (autosomal dominant, autosomal recessive, and X-linked forms exist), there is a possibility that some clinically defined subtypes of the disease may be the result of mutations at the same locus. One possible clinically defined subtype is that of autosomal dominant retinitis pigmentosa (ADRP) with incomplete penetrance. Whereas in most families with ADRP, carriers can be clearly identified because of visual loss, ophthalmological findings, or abnormal electroretinograms (ERGs), in occasional families some obligate carriers are asymptomatic and have normal or nearly normal ERGs even late in life. A recent paper reported the mapping of the diseases locus in one pedigree (designated adRP7) with ADRP with incomplete penetrance to chromosome 7p. To test the idea that ADRP with incomplete penetrance may be genetically homogeneous, we have evaluated whether a different family with incomplete penetrance also has a disease gene linked to the same region. 4 refs., 1 fig., 1 tab.

  1. New scheme for enhancement of maximum proton energy with a cone-hole target irradiated by a short intense laser pulse

    NASA Astrophysics Data System (ADS)

    Yang, Siqian; Zhou, Weimin; Jiao, Jinlong; Zhang, Zhimeng; Cao, Leifeng; Gu, Yuqiu; Zhang, Baohan

    2017-03-01

    Improvement of proton energy from short intense laser interaction with a new proposal of a cone-hole target is investigated via two-dimensional particle-in-cell simulations. The configuration of the target is a cone structure with a hole of changeable diameter through the center of the tip, with proton layers contaminated both on the target rear surface and at the rear part of the hole. In the interacting process, the cone-hole geometry enables the focus of the laser pulse by the cone structure and the consequent penetration of the intensified laser through the tip along the hole instead of reflection, which can increase the energy coupling from laser field to plasmas. The heated electrons, following the target normal sheath acceleration scheme, induce a much stronger electrostatic field in the longitudinal direction at the rear surface of the target than that in the traditional foil case. The simulation results indicate that the accelerated proton beam from the cone-hole target has a cutoff energy about 5.7 and 2.1 times larger than the foil case and the hollow cone case, respectively. Furthermore, the case of the cone-hole target without the proton layer in the hole is also analyzed to demonstrate the effect of the proton layer position and the results show that not only can the existence of the central proton layer improve the proton energy but also lead to a better collimation. The dependence of proton energy on the hole diameter and the scaling law of the maximum proton energy relative to laser intensity are also presented.

  2. Enabling kinetic micro-penetrator technology for Solar System research

    NASA Astrophysics Data System (ADS)

    Gowen, R. A.

    2008-09-01

    Whilst the concept of high speed impacting penetrator probes is not new, recent highly successful ground test results have considerably improved the perception that these can be a viable and useful addition to the current toolbox of planetary probes. Previous developments only led to a single deployment (Deep Space-2 to Mars on the ill fated NASA Mars Polar Lander mission in 1999) where neither the soft lander nor penetrator was ever heard from, which is not a logical basis for dismissing penetrator technology. Other space penetrator programmes have included the Russian Mars'96 ~80m/s penetrators for which the whole mission was lost before the spacecraft left Earth orbit, and the Japanese Lunar-A program which was cancelled after a lengthy development program which however saw multiple successful ground trials. The Japanese penetrators were designed for ~300m/s impact. The current UK penetrator developments are actively working towards full space qualification for a Lunar penetrators (MoonLITE mission), which would also provide a significant technical demonstration towards the development of smaller, shorter lived penetrators for exploring other solar system objects. We are advocating delivered micro-penetrators in the mass range ~4-10Kg, (preceded by ~13Kg Lunar penetrator MoonLITE development program), impacting at around 100-500m/s and carrying a scientific payload of around 2Kg. Additional mass is required to deliver the probes from `orbit' to surface which is dependent upon the particular planetary body in question. The mass per descent module therefore involves and additional element which, for a descent through an atmosphere could be quite modest, while for a flyby deployment, can be substantial. For Europa we estimate a descent module mass of ~13 Kg, while for Enceladus the value is ~40Kg for Enceladus since a deceleration of ~3.8 kms-1 is needed from a Titan orbit. The delivery system could consist of a rocket deceleration motor and attitude control system

  3. Proper bit design improves penetration rate in abrasive horizontal wells

    SciTech Connect

    Gentges, R.J. )

    1993-08-09

    Overall drilling penetration rates nearly tripled, and drill bit life nearly doubled compared to conventional bits when specially designed natural diamond and polycrystalline diamond compact (PDC) bits were used during a seven-well horizontal drilling program. The improvement in drilling performance from better-designed bits lowered drilling costs at ANR Pipeline Co.'s Reed City gas storage field in Michigan. Laboratory tests with scaled down bits used on abrasive cores helped determine the optimum design for drilling the gas storage wells. The laboratory test results and actual field data were used to develop a matrix-body natural diamond bit, which was later modified to become a matrix-body, blade-type polycrystalline diamond compact bit. This bit had excellent penetration rates and abrasion resistance. The paper describes the background to the project, bit selection, natural diamond bits, field results, new bit designs, and field results from the new design.

  4. Correct use of cone penetrometer sensors to predict subsurface conditions

    SciTech Connect

    Walker, J.L.; Rose, C.M.; Armstrong, S.C.; Burton, J.C.

    1997-09-01

    When cone penetrometer testing (CPT) technology is used with in-situ sensors and probes to characterize subsurface conditions in environmental investigations, each sensor must be calibrated with high quality, site specific data to establish essential interpretation criteria. Mechanical, geophysical, and chemical sensor data collected for a site in South Carolina without such controls were misleading. Core logs obtained subsequently had major lithologic discrepancies with the soil classification based on the CPT sensor data. In addition, detailed core sampling and laboratory analysis showed that the sensor data on chemical contaminants included false positive and false negative results. In contrast, for a site in Nebraska, CPT data calibrated with high quality site controls provided a detailed interpretation of subsurface conditions relevant to contaminant fate and transport. On the basis of the work in Nebraska, Argonne scientists are continuing to develop criteria to improve the interpretation of complex subsurface stratigraphy.

  5. Hypersonic Flows About a 25 degree Sharp Cone

    NASA Technical Reports Server (NTRS)

    Moss, James N.

    2001-01-01

    This paper presents the results of a numerical study that examines the surface heating discrepancies observed between computed and measured values along a sharp cone. With Mach numbers of an order of 10 and the freestream length Reynolds number of an order of 10 000, the present computations have been made with the direct simulation Monte Carlo (DSMC) method by using the G2 code of Bird. The flow conditions are those specified for two experiments conducted in the Veridian 48-inch Hypersonic Shock Tunnel. Axisymmetric simulations are made since the test model was assumed to be at zero incidence. Details of the current calculations are presented, along with comparisons between the experimental data, for surface heating and pressure distributions. Results of the comparisons show major differences in measured and calculated results for heating distributions, with differences in excess of 25 percent for the two cases examined.

  6. Mach Cones in Weakly and Strongly Coupled Dusty Magnetoplasmas

    SciTech Connect

    Mamun, A.A.; Shukla, P.K.

    2005-10-31

    A theoretical investigation on the formation of Mach cones in weakly and strongly coupled dusty magnetoplasmas has been presented. The salient features of dust-acoustic and dust-magnetoacoustic Mach cones in a weakly coupled dusty magnetoplasma as well as dust-acoustic Mach cones in a strongly coupled dusty magnetoplasma have been clearly explained. The relevance of this theoretical investigation to the formation of such dust-acoustic and dust-magnetoacoustic Mach cones in Saturn's dusty rings and laboratory dusty plasma experiments are discussed.

  7. Identifying Dirac cones in carbon allotropes with square symmetry.

    PubMed

    Wang, Jinying; Huang, Huaqing; Duan, Wenhui; Liu, Zhirong

    2013-11-14

    A theoretical study is conducted to search for Dirac cones in two-dimensional carbon allotropes with square symmetry. By enumerating the carbon atoms in a unit cell up to 12, an allotrope with octatomic rings is recognized to possess Dirac cones under a simple tight-binding approach. The obtained Dirac cones are accompanied by flat bands at the Fermi level, and the resulting massless Dirac-Weyl fermions are chiral particles with a pseudospin of S = 1, rather than the conventional S = 1∕2 of graphene. The spin-1 Dirac cones are also predicted to exist in hexagonal graphene antidot lattices.

  8. Rapid Measurement of Individual Cone Photoreceptor Pointing using Focus Diversity

    PubMed Central

    Morris, Hugh J.; Codona, Johanan L.; Blanco, Leonardo; Doble, Nathan

    2015-01-01

    A novel method is presented to rapidly measure the pointing direction of individual human cone photoreceptors using adaptive optics (AO) retinal imaging. For a fixed entrance pupil position, the focal plane is rapidly modulated to image the guided light in various axial planes. For cones with different pointing directions, this focus diversity will cause a shift in their apparent position, allowing for their relative pointing to be determined. For four normal human subjects, retinal images were acquired, registered and the positions of individual cones tracked throughout the dataset. Variation in cone tilt was 0.02 radians, agreeing with other objective measurements on the same subjects at the same retinal locations. PMID:26368692

  9. The trip of the tip: understanding the growth cone machinery

    PubMed Central

    Lowery, Laura Anne; Van Vactor, David

    2009-01-01

    Preface The central player in the road trip of axon guidance is the growth cone, a dynamic structure located at the tip of the growing axon. During its journey, the growth cone comprises both `vehicle' and `navigator'. Whereas the `vehicle' maintains growth cone movement and provides the cytoskeletal structural elements of its framework, a motor to move forward, and a mechanism to provide traction on the road, the `navigator' aspect guides this system in a spatially-biased way to translate environmental signals into directional movement. Understanding the functions and regulation of the vehicle and navigator provides new insights into the cell biology of growth cone guidance. PMID:19373241

  10. Dynamics on the cone: Closed orbits and superintegrability

    SciTech Connect

    Brihaye, Y.; Kosiński, P.

    2014-05-15

    The generalization of Bertrand’s theorem to the case of the motion of point particle on the surface of a cone is presented. The superintegrability of such models is discussed. The additional integrals of motion are analysed for the case of Kepler and harmonic oscillator potentials. -- Highlights: •Bertrand’s theorem is generalized to the case of the motion on a cone. •The superintegrability of the dynamics on a cone is discussed. •The W-algebra of integrals of motion for Kepler and harmonic oscillator problems on a cone is derived.

  11. High Penetration PV: How High Can We Go?

    SciTech Connect

    2016-01-01

    Brochure highlighting NREL's partnership with SolarCity and Hawaiian Electric (HECO) to increase the penetration of solar photovoltaics on the electricity grid. To better understand the potential impact of transient overvoltages due to load rejection, NREL collaborated with SolarCity and HECO to run a series of tests measuring the magnitude and duration of load rejection overvoltage events and demonstrating the ability of advanced PV inverters to mitigate their impacts.

  12. Field measurement of penetrator seismic coupling in sediments and volcanic rocks

    NASA Technical Reports Server (NTRS)

    Nakamura, Y.; Latham, G. V.; Frohlich, C.

    1979-01-01

    Field experiments were conducted to determine experimentally how well a seismometer installed using a penetrator would be coupled to the ground. A dry lake bed and a lava bed were chosen as test sites to represent geological environments of two widely different material properties. At each site, two half-scale penetrators were fired into the ground, a three-component geophone assembly was mounted to the aft end of each penetrator, and dummy penetrators were fired at various distances to generate seismic signals. The recorded signals were digitized, and cross-spectral analyses were performed to compare the observed signals in terms of power spectral density ratio, coherence and phase difference. The analyses indicate that seismometers deployed by penetrators will be as well coupled to the ground as are seismometers installed by conventional methods for the frequency range of interest in earthquake seismology, although some minor differences were observed at frequencies near the upper limit of the frequency band.

  13. Antimicrobial effect of three disinfecting agents on Resilon cones and their effect on surface topography: An in vitro study

    PubMed Central

    Chandrappa, Mahesh Martur; Meharwade, Prasanna Mahadevasa; Srinivasan, Raghu; Bhandary, Shreetha; Nasreen, Farhat

    2016-01-01

    Aim: The objective of this study was to evaluate the effectiveness of 5.25% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX), and 2% peracetic acid (PAA) in disinfecting Resilon cones and to evaluate topographical changes microscopically under scanning electron microscope (SEM) after rapid chemical disinfection. Materials and Methods: Resilon cones were disinfected in an ultraviolet (UV) light chamber for 20 min and contaminated by immersing in a microbial suspension of Enterococcus faecalis for 30 min. The contaminated cones were then immersed in the 5.25% NaOCl, 2% CHX, and 2% PAA for 1 min, 5 min, and 10 min, separately. The cones were then incubated at 37°C in thioglycollate broth for 7 days and examined for turbidity. The samples showing turbidity were subcultured on blood agar and incubated at 37°C for 48 h. Gram staining was done to confirm that the cultured bacteria were E. faecalis. Surface changes of disinfected Resilon cones were evaluated under SEM. Statistical Analysis Used: The data were analyzed statistically using Kruskal-Wallis, analysis of variance (ANOVA), and Mann–Whitney U-test. Result: In eliminating E. faecalis, 5.25% NaOCl was most effective followed by 2% PAA and 2% CHX. Topographic examination of tested Resilon cones revealed some surface deposits after disinfection with 5.25% NaOCl and 2% CHX, whereas 2% PAA caused surface erosion. Conclusion: In disinfecting Resilon cones, 5.25% NaOCl is most effective followed by 2% PAA and 2% CHX. PMID:27099418

  14. Modeling pollutant penetration across building envelopes

    SciTech Connect

    Liu, De-Ling; Nazaroff, William W.

    2001-04-01

    As air infiltrates through unintentional openings in building envelopes, pollutants may interact with adjacent surfaces. Such interactions can alter human exposure to air pollutants of outdoor origin. We present modeling explorations of the proportion of particles and reactive gases (e.g., ozone) that penetrate building envelopes as air enters through cracks and wall cavities. Calculations were performed for idealized rectangular cracks, assuming regular geometry, smooth inner crack surface and steady airflow. Particles of 0.1-1.0 {micro}m diameter are predicted to have the highest penetration efficiency, nearly unity for crack heights of 0.25 mm or larger, assuming a pressure difference of 4 Pa or greater and a flow path length of 3 cm or less. Supermicron and ultrafine particles are significantly removed by means of gravitational settling and Brownian diffusion, respectively. In addition to crack geometry, ozone penetration depends on its reactivity with crack surfaces, as parameterized by the reaction probability. For reaction probabilities less than {approx}10{sup -5}, penetration is complete for cracks heights greater than 1 mm. However, penetration through mm scale cracks is small if the reaction probability is {approx}10{sup -4} or greater. For wall cavities, fiberglass insulation is an efficient particle filter, but particles would penetrate efficiently through uninsulated wall cavities or through insulated cavities with significant airflow bypass. The ozone reaction probability on fiberglass fibers was measured to be 10{sup -7} for fibers previously exposed to high ozone levels and 6 x 10{sup -6} for unexposed fibers. Over this range, ozone penetration through fiberglass insulation would vary from >90% to {approx}10-40%. Thus, under many conditions penetration is high; however, there are realistic circumstances in which building envelopes can provide substantial pollutant removal. Not enough is yet known about the detailed nature of pollutant penetration

  15. Point spread function modeling and image restoration for cone-beam CT

    NASA Astrophysics Data System (ADS)

    Zhang, Hua; Huang, Kui-Dong; Shi, Yi-Kai; Xu, Zhe

    2015-03-01

    X-ray cone-beam computed tomography (CT) has such notable features as high efficiency and precision, and is widely used in the fields of medical imaging and industrial non-destructive testing, but the inherent imaging degradation reduces the quality of CT images. Aimed at the problems of projection image degradation and restoration in cone-beam CT, a point spread function (PSF) modeling method is proposed first. The general PSF model of cone-beam CT is established, and based on it, the PSF under arbitrary scanning conditions can be calculated directly for projection image restoration without the additional measurement, which greatly improved the application convenience of cone-beam CT. Secondly, a projection image restoration algorithm based on pre-filtering and pre-segmentation is proposed, which can make the edge contours in projection images and slice images clearer after restoration, and control the noise in the equivalent level to the original images. Finally, the experiments verified the feasibility and effectiveness of the proposed methods. Supported by National Science and Technology Major Project of the Ministry of Industry and Information Technology of China (2012ZX04007021), Young Scientists Fund of National Natural Science Foundation of China (51105315), Natural Science Basic Research Program of Shaanxi Province of China (2013JM7003) and Northwestern Polytechnical University Foundation for Fundamental Research (JC20120226, 3102014KYJD022)

  16. Coherent imaging of the cone mosaic in the living human eye.

    PubMed

    Marcos, S; Navarro, R; Artal, P

    1996-05-01

    A new system for the recording of high-resolution images of the cone mosaic in the living room fovea has been developed. The experimental method is inspired by stellar speckle interferometry, used in astronomy to resolve binary stars. Series of short-exposure images of small areas of the fovea are registered under coherent illumination. These images show speckle patterns that have some correlation with the topography of the cone mosaic and retain high-resolution information. Such correlation is better revealed in the power spectrum (square modulus of the Fourier transform). The signal-to-noise ratio is increased, without loss of high frequencies, by averaging the power spectra of a number of such speckle patterns. The average power spectra show, in most of the cases, an elliptical ring (or hexagon), whose mean radius corresponds to the characteristic spatial frequency of the cone mosaic (or the inverse of the mean row-to-row cone spacing) at a given retinal location. Good results are obtained in the five normal observers tested, at various retinal eccentricities, up to 1 visual degree, including the center of the fovea for two eyes. We find a decrease in the spatial frequency of the mosaic with the eccentricity and an important intersubject variability, in agreement with anatomical studies.

  17. Unsteady pressure measurements of decelerated swirling flow in a discharge cone at lower runner speeds

    NASA Astrophysics Data System (ADS)

    Bosioc, A. I.; Muntean, S.; Tanasa, C.; Susan-Resiga, R.; Vékás, L.

    2014-03-01

    The decelerated swirling flow in the draft tube cone of hydraulic turbines (especially turbines with fixed blades) is responsible for self-induced instabilities which generates pressure pulsations that hinder the turbine operation. An experimental test rig was developed in order to investigate the flow instabilities. A new method was implemented to slow down the runner using a magneto rheological brake in order to be extended the flow regimes investigated. As a result, the experimental investigations are performed for 7 operating regimes in order to quantify the flow behaviour from part load operation to overload operation. The unsteady pressure measurements are carried out on 4 levels in the cone. The unsteady pressure measurements on the cone wall consist in quantifying of three aspects: i) the pressure recovery coefficient obtained based on mean pressure provides the energetic assessment on the draft tube cone; ii) the unsteady quantities (dominant amplitude and frequency) are determined revealing the dynamic behaviour; iii) the plunging and rotating components of the pressure pulsation. As a result, this new method helps us to investigate in detail the flow instability for different operating regimes and allows investigating various flow control solutions.

  18. Two Dimensional Heat Transfer around Penetrations in Multilayer Insulation

    NASA Technical Reports Server (NTRS)

    Johnson, Wesley L.; Kelly, Andrew O.; Jumper, Kevin M.

    2012-01-01

    The objective of this task was to quantify thermal losses involving integrating MLI into real life situations. Testing specifically focused on the effects of penetrations (including structural attachments, electrical conduit/feedthroughs, and fluid lines) through MLI. While there have been attempts at quantifying these losses both analytically and experimentally, none have included a thorough investigation of the methods and materials that could be used in such applications. To attempt to quantify the excess heat load coming into the system due to the integration losses, a calorimeter was designed to study two dimensional heat transfer through penetrated MLI. The test matrix was designed to take as many variables into account as was possible with the limited test duration and system size. The parameters varied were the attachment mechanism, the buffer material (for buffer attachment mechanisms only), the thickness of the buffer, and the penetration material. The work done under this task is an attempt to measure the parasitic heat loads and affected insulation areas produced by system integration, to model the parasitic loads, and from the model produce engineering equations to allow for the determination of parasitic heat loads in future applications. The methods of integration investigated were no integration, using a buffer to thermally isolate the strut from the MLI, and temperature matching the MLI on the strut. Several materials were investigated as a buffer material including aerogel blankets, aerogel bead packages, cryolite, and even an evacuated vacuum space (in essence a no buffer condition).

  19. Pressure enhanced penetration with shaped charge perforators

    DOEpatents

    Glenn, Lewis A.

    2001-01-01

    A downhole tool, adapted to retain a shaped charge surrounded by a superatmospherically pressurized light gas, is employed in a method for perforating a casing and penetrating reservoir rock around a wellbore. Penetration of a shaped charge jet can be enhanced by at least 40% by imploding a liner in the high pressure, light gas atmosphere. The gas pressure helps confine the jet on the axis of penetration in the latter stages of formation. The light gas, such as helium or hydrogen, is employed to keep the gas density low enough so as not to inhibit liner collapse.

  20. Sphere impact and penetration into wet sand.

    PubMed

    Marston, J O; Vakarelski, I U; Thoroddsen, S T

    2012-08-01

    We present experimental results for the penetration of a solid sphere when released onto wet sand. We show, by measuring the final penetration depth, that the cohesion induced by the water can result in either a deeper or shallower penetration for a given release height compared to dry granular material. Thus the presence of water can either lubricate or stiffen the granular material. By assuming the shear rate is proportional to the impact velocity and using the depth-averaged stopping force in calculating the shear stress, we derive effective viscosities for the wet granular materials.