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. Nationwide lithological interpretation of cone penetration tests using neural networks

    NASA Astrophysics Data System (ADS)

    van Maanen, Peter-Paul; Schokker, Jeroen; Harting, Ronald; de Bruijn, Renée

    2017-04-01

    The Geological Survey of the Netherlands (GSN) systematically produces 3D stochastic geological models of the Dutch subsurface. These voxel models are regarded essential in answering subsurface-related questions on, for example, aggregate resource potential, groundwater flow, land subsidence hazard and the planning and realization of large-scale infrastructural works. GeoTOP is the most recent and detailed generation of 3D voxel models. This model describes 3D stratigraphical and lithological variability up to a depth of 50 m using voxels of 100 × 100 × 0.5 m. Currently, visually described borehole samples are the primary input of these large-scale 3D geological models, both when modeling architecture and composition. Although tens of thousands of cone penetration tests (CPTs) are performed each year, mainly in the reconnaissance phase of construction activities, these data are hardly used as geological model input. There are many reasons why it is of interest to utilize CPT data for geological and lithological modeling of the Dutch subsurface, such as: 1) CPTs are more abundant than borehole descriptions, 2) CPTs are cheaper and easier to gather, and 3) CPT data are more quantitative and uniform than visual sample descriptions. This study uses CPTs and the lithological descriptions of associated nearby undisturbed drilling cores collected by the GSN to establish a nationwide reference dataset for physical and chemical properties of the shallow subsurface. The 167 CPT-core pairs were collected at 160 locations situated in the North, West and South of the Netherlands. These locations were chosen to cover the full extent of geological units and lithological composition in the upper 30 to 40 m of the subsurface in these areas. The distance between the CPT location and associated borehole is small, varying between 0 and 30 m, with an average of 6 m. For each 2 cm CPT interval the data was automatically annotated with the lithoclass from the associated core using a

  4. 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.

  5. 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

  6. 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.

  7. 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

  8. 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

  9. 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.

  10. Groundwater salinity patterns along the coast of the Western Netherlands and the application of cone penetration tests

    NASA Astrophysics Data System (ADS)

    Pauw, P. S.; Groen, J.; Groen, M. M. A.; van der Made, K. J.; Stuyfzand, P. J.; Post, V. E. A.

    2017-08-01

    Submarine groundwater discharge is an important part of the hydrological cycle, but remains under-investigated for confined aquifers with no surface outcrop at the beach. This paper considers the offshore directed flow of fresh groundwater in the unconfined and confined aquifers along the coast of the Western Netherlands. Salinity patterns based on hydrological, geological, and geophysical field data are presented in five shore-normal hydrogeological cross-sections, extending from the beach to 4 km inland. The offshore continuation of the fresh groundwater is discussed using analytical models and cone penetration tests (CPTs) performed at the beach. All CPTs taken around the low water line of the intertidal zone reveal that changes from saline to fresh groundwater are always associated with a low-permeable layer. Such a low-permeable layer, which can be as thin as a few decimetres, may form the confining layer between the unconfined and confined aquifers, or can occur within of the unconfined aquifer. Due to its high vertical resolution, a CPT is an effective method to detect these variations in salinity and lithology. At each of the investigated locations, freshwater was present in the confined aquifer. Assuming that this fresh groundwater is part of an active flow system, the submarine freshwater tongue is estimated to extend at least a few hundred meters offshore, based on analytical model calculations. Hydrochemical data from an old offshore borehole, however, suggest this may be an underestimate and that the submarine freshwater tongue originates from former times when the coastline was located further westward than nowadays.

  11. Modeling of light dynamic cone penetration test - Panda 3 ® in granular material by using 3D Discrete element method

    NASA Astrophysics Data System (ADS)

    Tran, Quoc Anh; Chevalier, Bastien; Benz, Miguel; Breul, Pierre; Gourvès, Roland

    2017-06-01

    The recent technological developments made on the light dynamic penetration test Panda 3 ® provide a dynamic load-penetration curve σp - sp for each impact. This curve is influenced by the mechanical and physical properties of the investigated granular media. In order to analyze and exploit the load-penetration curve, a numerical model of penetration test using 3D Discrete Element Method is proposed for reproducing tests in dynamic conditions in granular media. All parameters of impact used in this model have at first been calibrated by respecting mechanical and geometrical properties of the hammer and the rod. There is a good agreement between experimental results and the ones obtained from simulations in 2D or 3D. After creating a sample, we will simulate the Panda 3 ®. It is possible to measure directly the dynamic load-penetration curve occurring at the tip for each impact. Using the force and acceleration measured in the top part of the rod, it is possible to separate the incident and reflected waves and then calculate the tip's load-penetration curve. The load-penetration curve obtained is qualitatively similar with that obtained by experimental tests. In addition, the frequency analysis of the measured signals present also a good compliance with that measured in reality when the tip resistance is qualitatively similar.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Application of 2D electrical resistivity imaging and cone penetration test (CPT) to assess the harzadous effect of near surface water on foundations in Lagos Nigeria

    NASA Astrophysics Data System (ADS)

    Adewoyin, O. O.; Joshua, E. O.; Akinyemi, M. L.; Omeje, M.; Joel, E. S.

    2017-05-01

    Adequate information on the condition of the subsurface is very important for site evaluation for engineering purposes. In this study two dimensional (2D) geoelectrical resistivity survey and cone penetration tests were conducted to study the hazardous effect of excess near surface water on the foundation of building in a reclaimed land located at Victoria Island area of Lagos State. The results of the inverted 2D geoelectrical resistivity data revealed three distinct geoelectrical layers characterized by low to moderate electrical resistivity of 2.23 and 129Ωm and 9.46 to 636Ωm respectively. The topsoil is characterized by wet sandy soil, which is underlain by sandy clay and banded at the below by a geologic formation of low resistivity which is suspected to be clay. The clay material may be responsible for the excess water retention observed in the area. The CPT method on the other hand revealed a geological formation of low resistance to penetration between 2-3 kg/cm2 from the topsoil to a depth of 7 m, which may be the effect of excess water in the near surface. This study revealed that the foundation of building may not be founded directly on the soil in any reclaimed land as this may result in collapse as a result of upward migration of water to the near surface.

  17. 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.

  18. Statistical analysis of cone penetration resistance of railway ballast

    NASA Astrophysics Data System (ADS)

    Saussine, Gilles; Dhemaied, Amine; Delforge, Quentin; Benfeddoul, Selim

    2017-06-01

    Dynamic penetrometer tests are widely used in geotechnical studies for soils characterization but their implementation tends to be difficult. The light penetrometer test is able to give information about a cone resistance useful in the field of geotechnics and recently validated as a parameter for the case of coarse granular materials. In order to characterize directly the railway ballast on track and sublayers of ballast, a huge test campaign has been carried out for more than 5 years in order to build up a database composed of 19,000 penetration tests including endoscopic video record on the French railway network. The main objective of this work is to give a first statistical analysis of cone resistance in the coarse granular layer which represents a major component of railway track: the ballast. The results show that the cone resistance (qd) increases with depth and presents strong variations corresponding to layers of different natures identified using the endoscopic records. In the first zone corresponding to the top 30cm, (qd) increases linearly with a slope of around 1MPa/cm for fresh ballast and fouled ballast. In the second zone below 30cm deep, (qd) increases more slowly with a slope of around 0,3MPa/cm and decreases below 50cm. These results show that there is no clear difference between fresh and fouled ballast. Hence, the (qd) sensitivity is important and increases with depth. The (qd) distribution for a set of tests does not follow a normal distribution. In the upper 30cm layer of ballast of track, data statistical treatment shows that train load and speed do not have any significant impact on the (qd) distribution for clean ballast; they increase by 50% the average value of (qd) for fouled ballast and increase the thickness as well. Below the 30cm upper layer, train load and speed have a clear impact on the (qd) distribution.

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Geological interpretation of cone penetrometer tests in Norton Sound, Alaska

    USGS Publications Warehouse

    Hampton, M.A.; Lee, H.J.; Beard, R.M.

    1982-01-01

    In situ cone-penetrometer tests at 11 stations in Norton Sound, Alaska, complement previous studies of geologic processes and provide geotechnical data for an analysis of sediment response to loading. Assessment of the penetrometer records shows that various geologic factors influence penetration resistance. On the Yukon prodelta, penetration resistance increases with the level of storm wave or ice loading. In central and eastern Norton Sound, thermogenic and biogenic gas, as well as variations in sediment texture and composition, effect a wide range of resistance to penetration. ?? 1982 A. M. Dowden, Inc.

  5. 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

  6. 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

  7. Cone penetrometer moisture probe acceptance test report

    SciTech Connect

    Barnes, G.A.

    1996-04-23

    This Acceptance Test Report (ATR) documents the results of WHC-SD-WM-ATP-146 (Prototype Cone Penetrometer Moisture Probe Acceptance Test Procedure) and WHC-SD-WM-ATP-145 (Cone Penetrometer Moisture Probe Acceptance Test Procedure). The master copy of WHC-SD-WM-ATP-145 can be found in Appendix A and the master copy of WHC-SD-WM-ATP-146 can be found in Appendix B. Also included with this report is a matrix showing design criteria of the cone penetrometer moisture probe and the verification method used (Appendix C).

  8. 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.

  9. 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.

  10. 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

  11. Standard Penetration Test and Relative Density

    DTIC Science & Technology

    1971-02-01

    penetration resistan ( e of soil, an empirical relation was established between the number of blows applied in the standard pene- tration test to sand below...more to a change in the mean grain diameter than did the pene- trometer in the standard penetration test. CONC LUSIONS In the standard penetration

  12. 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.

  13. 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.

  14. 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.

  15. Cone penetrometer moisture probe acceptance test procedure

    SciTech Connect

    Barnes, G.A.

    1996-01-01

    This report describes the procedure to be used for acceptance testing of the Cone Penetrometer Moisture Probe (CPMP) system. The system includes the probe and detectors, the winch system, the NIM bin electronics, the thermistor, the laptop computer, Input/Output (I/O) interfaces, LabVIEW` application with automatic scanning features and the calibration chamber. This Acceptance Test Procedure (ATP) will cover the function of all the components, and demonstrate data flow through the system, winch functions, and detector and temperature sensor sub- system functions in accordance with the Functional Design Criteria (FDC) specified in WHC-SD-WM-FDC-047.

  16. 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.

  17. 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.

  18. Continuum cavity expansion and discrete micromechanical models for inferring macroscopic snow mechanical properties from cone penetration data

    NASA Astrophysics Data System (ADS)

    Ruiz, Siul; Capelli, Achille; van Herwijnen, Alec; Schneebeli, Martin; Or, Dani

    2017-08-01

    Digital cone penetration measurements can be used to infer snow mechanical properties, for instance, to study snow avalanche formation. The standard interpretation of these measurements is based on statistically inferred micromechanical interactions between snow microstructural elements and a well-calibrated penetrating cone. We propose an alternative continuum model to derive the modulus of elasticity and yield strength of snow based on the widely used cavity expansion model in soils. We compare results from these approaches based on laboratory cone penetration measurements in snow samples of different densities and structural sizes. Results suggest that the micromechanical model underestimates the snow elastic modulus for dense samples by 2 orders of magnitude. By comparison with the cavity expansion-based model, some of the discrepancy is attributed to low sensitivity of the micromechanical model to the snow elastic modulus. Reasons and implications of this discrepancy are discussed, and possibilities to enhance both methodologies are proposed.

  19. Containment penetration elastomer seal leak rate tests

    SciTech Connect

    Bridges, T.L.

    1987-07-01

    Tests were performed on three elastomer seal designs commonly used for nuclear plant containment mechanical penetrations. The objective of this research project is to obtain an understanding of the integrity and leakage behavior of these seal designs under severe accident temperature and pressure conditions. The three designs tested and the seal materials used in the tests were: (1) double tongue-and-groove design with silicone rubber seals, (2) double-O-ring design with neoprene and ethylene-propylene (EPDM) seals, and (3) double gumdrop design with neoprene and EPDM seals. The effects of thermal aging and angular rotations of flange mating surfaces were determined. The test results provide information required to characterize the leakage behavior of penetrations under severe accident conditions. 3 refs., 10 figs., 12 tabs.

  20. 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.

  1. Cone calorimeter tests of wood composites

    Treesearch

    Robert H. White; Kuma Sumathipala

    2013-01-01

    The cone calorimeter is widely used for the determination of the heat release rate (HRR) of building products and other materials. As part of an effort to increase the availability of cone calorimeter data on wood products, the U.S. Forest Products Laboratory and the American Wood Council conducted this study on composite wood products in cooperation with the Composite...

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

    USDA-ARS?s Scientific Manuscript database

    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...

  3. 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

  4. 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

  5. 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.

  6. 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.

  7. Universal framework for unmanned system penetration testing

    NASA Astrophysics Data System (ADS)

    Kobezak, Philip; Abbot-McCune, Sam; Tront, Joseph; Marchany, Randy; Wicks, Alfred

    2013-05-01

    Multiple industries, from defense to medical, are increasing their use of unmanned systems. Today, many of these systems are rapidly designed, tested, and deployed without adequate security testing. To aid the quick turnaround, commercially available subsystems and embedded components are often used. These components may introduce security vulnerabilities particularly if the designers do not fully understand their functionality and limitations. There is a need for thorough testing of unmanned systems for security vulnerabilities, which includes all subsystems. Using a penetration testing framework would help find these vulnerabilities across different unmanned systems applications. The framework should encompass all of the commonly implemented subsystems including, but not limited to, wireless networks, CAN buses, passive and active sensors, positioning receivers, and data storage devices. Potential attacks and vulnerabilities can be identified by looking at the unique characteristics of these subsystems. The framework will clearly outline the attack vectors as they relate to each subsystem. If any vulnerabilities exist, a mitigation plan can be developed prior to the completion of the design phase. Additionally, if the vulnerabilities are known in advance of deployment, monitoring can be added to the design to alert operators of any attempted or successful attacks. This proposed framework will help evaluate security risks quickly and consistently to ensure new unmanned systems are ready for deployment. Verifying that a new unmanned system has passed a comprehensive security evaluation will ensure greater confidence in its operational effectiveness.

  8. 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.

  9. Measurement of in-situ strength using projectile penetration: Tests of a new launching system

    SciTech Connect

    Hearst, J.R.; Newmark, R.L.; Charest, J.A.; Lynch, C.S.

    1987-10-01

    The Lawrence Livermore National Laboratory has a continuing need to measure rock strength in situ, both for simple prediction of cavity size, and as input to computational models. In a previous report we compared two methods for measuring formation strength in situ: projectile penetration and a cone penetrometer. We determined that the projectile method was more promising for application to our large-diameter (2-4-m) hole environment. A major practical problem has been the development of a launcher and an apparatus for measuring depth of penetration that would be suitable for use in large-diameter holes. We are developing a gas-gun launcher system that will be capable of measuring both depth of penetration and deceleration of a reusable projectile. The current version of the launcher is trailer-mounted for testing at our Nevada Test Site (NTS) in tunnels and outcrops, but its design is such that it can be readily adapted for emplacement hole use. We test the current launcher on 60-cm cubes of gypsum cement, mixed to provie a range of densities (1.64 to 2.0 g/cc) and strengths (3 to 17 MPa). We compared depth of penetration of a 84-g projectile from a ''Betsy'' seismic gun - traveling on the order of 500 m/s - with the depth of penetration of a 13-kg projectile from the gas gun - traveling on the order of 30 m/s. For projectiles with the same nose size and shape, impacting targets of approximately constant strength, penetration depth was proportional to projectile kinetic energy. The ratio of kinetic energy to penetration depth was approximately proportional to target strength. Tests in tuffs with a wide range of strengths at NTS gave a similar linear relationship between the ratio of kinetic energy to penetration and target strength, and also a linear relationship between deceleration and strength. It appears that penetration can indeed be used as a semiquantitative measure of strength.

  10. Rapid quantification of color vision: the cone contrast test.

    PubMed

    Rabin, Jeff; Gooch, John; Ivan, Douglas

    2011-02-09

    To describe the design, specificity, and sensitivity of the cone contrast test (CCT), a computer-based, cone-specific (L, M, S) contrast sensitivity test for diagnosing type and severity of color vision deficiency (CVD). The CCT presents a randomized series of colored letters visible only to L, M or S cones in decreasing steps of cone contrast to determine L, M, and S letter-recognition thresholds. Sensitivity and specificity were determined by retrospective comparison of CCT scores to anomaloscope and pseudoisochromatic plate (PIP) results in 1446 applicants for pilot training. CVD was detected in 49 (3.4%) of 1446 applicants with hereditary red-green (protan or deutan) CVD detected in 47 (3.5%) of 1359 men and blue-yellow (tritan) in 2 of 1446. In agreement with the anomaloscope, the CCT showed 100% sensitivity for detection and categorization of CVD (40 deutan, 7 protan, 2 tritan). PIP testing showed lower sensitivity (80% detected; 20% missed) due in part to the applicant's prior experience and/or pretest preparation. CCT specificity for confirming normal color vision was 100% for L and M cone tests and 99.8% for S cones. The CCT has sensitivity and specificity comparable to anomaloscope testing and exceeds PIP sensitivity in practiced observers. The CCT provides a rapid (6 minutes), clinically expedient, measure of color vision for quantifying normal color performance, diagnosing type and severity of hereditary deficiency, and detection of acquired sensitivity loss due to ocular, neurologic, and/or systemic disease, as well as injury and physiological stressors, such as altitude and fatigue.

  11. 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

  12. Cone calorimeter testing of vegetation--an update

    Treesearch

    Robert H. White; David R. Weise; Kurt Mackes; Alison C. Dibble

    2002-01-01

    As part of efforts to address fire problems in the wildland-urban interface, the cone calorimeter is being used to measure the relative flammability of different plant species. In the first two studies, we tested plants used to landscape homes in California and an assortment of plants found in Colorado. Using the effective heat of combustion and the peak heat release...

  13. 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.

  14. 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.

  15. On the measurement of ultrasound transmission through a penetrable acoustic cone

    NASA Astrophysics Data System (ADS)

    Huthwaite, P.; Simonetti, F.

    2011-03-01

    Breast ultrasound tomography (BUST) is currently being developed for the early detection of cancer. Images of mechanical properties across the breast are formed using ultrasonic signals transmitted through the breast immersed in water. This is possible because the perturbation to the free propagation of ultrasound induced by the presence of the breast encodes information about the material properties of the breast. To achieve high sensitivity with BUST it is therefore crucial that the perturbation is most sensitive to the internal lesions inside the breast. However, the perturbation is also affected by the shape of the breast which can cause significant and undesired refraction effects. To understand the effect of breast shape on the transmission of ultrasound, this paper investigates transmission through a cone with properties similar to that of breast tissue. We show that it is possible to identify two regimes of transmission depending on the physical properties of the cone and transducers. While the first regime is suitable for BUST measurements, the second regime is highly affected by the breast shape and measurements are not reliable for accurate reconstructions. We provide a physical approximation that describes transmission in the first regime and which will aid the design of future BUST systems.

  16. 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

  17. 49 CFR Appendix E to Part 178 - Flame Penetration Resistance Test

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... point 4 inches above the test specimen, centered over the burner cone, must not exceed 205 °C (400 °F... the test burner cone. (4) Thermocouples. The seven thermocouples to be used for testing must be 1/16... mounted on a suitable stand to position the exit of the burner cone a distance of 8 inches from the...

  18. 49 CFR Appendix E to Part 178 - Flame Penetration Resistance Test

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... point 4 inches above the test specimen, centered over the burner cone, must not exceed 205 °C (400 °F... the test burner cone. (4) Thermocouples. The seven thermocouples to be used for testing must be 1/16... mounted on a suitable stand to position the exit of the burner cone a distance of 8 inches from the...

  19. 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

  20. 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.

  1. 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.

  2. Pyrolysis kinetics and combustion of thin wood using advanced cone calorimetry test method

    Treesearch

    Mark A. Dietenberger

    2011-01-01

    Mechanistic pyrolysis kinetics analysis of extractives, holocellulose, and lignin in solid wood over entire heating regime was possible using specialized cone calorimeter test and new mathematical analysis tools. Added hardware components include: modified sample holder for thin specimen with tiny thermocouples, methane ring burner with stainless steel mesh above cone...

  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. 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.

  8. 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.

  9. 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.

  10. 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

  11. Testing for a Gap Junction-Mediated Bystander Effect in Retinitis Pigmentosa: Secondary Cone Death Is Not Altered by Deletion of Connexin36 from Cones

    PubMed Central

    Kranz, Katharina; Paquet-Durand, François; Weiler, Reto

    2013-01-01

    Retinitis pigmentosa (RP) relates to a group of hereditary neurodegenerative diseases of the retina. On the cellular level, RP results in the primary death of rod photoreceptors, caused by rod-specific mutations, followed by a secondary degeneration of genetically normal cones. Different mechanisms may influence the spread of cell death from one photoreceptor type to the other. As one of these mechanisms a gap junction-mediated bystander effect was proposed, i.e., toxic molecules generated in dying rods and propagating through gap junctions induce the death of healthy cone photoreceptors. We investigated whether disruption of rod-cone coupling can prevent secondary cone death and reduce the spread of degeneration. We tested this hypothesis in two different mouse models for retinal degeneration (rhodopsin knockout and rd1) by crossbreeding them with connexin36-deficient mice as connexin36 represents the gap junction protein on the cone side and lack thereof most likely disrupts rod-cone coupling. Using immunohistochemistry, we compared the progress of cone degeneration between connexin36-deficient mouse mutants and their connexin36-expressing littermates at different ages and assessed the accompanied morphological changes during the onset (rhodopsin knockout) and later stages of secondary cone death (rd1 mutants). Connexin36-deficient mouse mutants showed the same time course of cone degeneration and the same morphological changes in second order neurons as their connexin36-expressing littermates. Thus, our results indicate that disruption of connexin36-mediated rod-cone coupling does not stop, delay or spatially restrict secondary cone degeneration and suggest that the gap junction-mediated bystander effect does not contribute to the progression of RP. PMID:23468924

  12. 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.

  13. Design, synthesis, and functional testing of recombinant cell penetrating peptides

    NASA Astrophysics Data System (ADS)

    Widyaningtyas, S. T.; Soebandrio, A.; Ibrahim, F.; Bela, B.

    2017-08-01

    Cell penetrating peptides (CPP) are one of the most attractive DNA delivery systems currently in development. In this research, in silico CPP development was performed based on a literature study to look for peptides that induce endosome escape, have the ability to bind DNA, and pass through cell membranes and/or nuclear membranes with a final goal of creating a new CPP to be used as a DNA delivery system. We report herein the successful isolation of three candidate CPP molecules, which have all been successfully expressed and purified by NiNTA. One of the determinants of CPP success as a DNA carrier is the ability of the CPP to bind and protect DNA from the effects of nucleases. The DNA binding test results show that all three CPPs can bind to DNA and protect it from the effects of serum nucleases. These three CPP candidates designed in silico and synthesized in the prokaryote system are eligible candidates for further testing of their ability to deliver DNA in vitro and in vivo.

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. 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

  19. 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... MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR PACKAGINGS Pt. 178, App. E Appendix E to Part 178—Flame Penetration Resistance Test (a) Criteria for Acceptance. (1...

  20. 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....

  1. Accuracy of four commonly used color vision tests in the identification of cone disorders.

    PubMed

    Thiadens, Alberta A H J; Hoyng, Carel B; Polling, Jan Roelof; Bernaerts-Biskop, Riet; van den Born, L Ingeborgh; Klaver, Caroline C W

    2013-04-01

    To determine which color vision test is most appropriate for the identification of cone disorders. In a clinic-based study, four commonly used color vision tests were compared between patients with cone dystrophy (n = 37), controls with normal visual acuity (n = 35), and controls with low vision (n = 39) and legal blindness (n = 11). Mean outcome measures were specificity, sensitivity, positive predictive value and discriminative accuracy of the Ishihara test, Hardy-Rand-Rittler (HRR) test, and the Lanthony and Farnsworth Panel D-15 tests. In the comparison between cone dystrophy and all controls, sensitivity, specificity and predictive value were highest for the HRR and Ishihara tests. When patients were compared to controls with normal vision, discriminative accuracy was highest for the HRR test (c-statistic for PD-axes 1, for T-axis 0.851). When compared to controls with poor vision, discriminative accuracy was again highest for the HRR test (c-statistic for PD-axes 0.900, for T-axis 0.766), followed by the Lanthony Panel D-15 test (c-statistic for PD-axes 0.880, for T-axis 0.500) and Ishihara test (c-statistic 0.886). Discriminative accuracies of all tests did not further decrease when patients were compared to controls who were legally blind. The HRR, Lanthony Panel D-15 and Ishihara all have a high discriminative accuracy to identify cone disorders, but the highest scores were for the HRR test. Poor visual acuity slightly decreased the accuracy of all tests. Our advice is to use the HRR test since this test also allows for evaluation of all three color axes and quantification of color defects.

  2. 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.

  3. 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.

  4. Pyrolysis kinetics and combustion of thin wood by an advanced cone caorimetry test method

    Treesearch

    Mark Dietenberger

    2012-01-01

    Pyrolysis kinetics analysis of extractives, holocellulose, and lignin in the solid redwood over the entire heating regime was possible by specialized cone calorimeter test and new mathematical analysis tools. Added hardware components include: modified sample holder for the thin specimen with tiny thermocouples, the methane ring burner with stainless-steel mesh above...

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Electronic cone penetration testing at the Hanford Site, 200 West Area

    SciTech Connect

    Rohay, V.J.

    1993-06-04

    The 200 West Area Carbon Tetrachloride Expedited Response Action (ERA) is being conducted by the US Department of Energy (DOE) at the direction of the US Environmental Protection Agency (EPA) and the Washington Department of Ecology as a provision of both the Comprehensive Environmental Response Compensation and Liability Act of 1980 (CERCLA) and the Integrated Demonstration for Cleanup of Volatile Organic Compounds at Arid Sites (VOC-Arid ID). The ERA allows expedited response to be taken at waste sites where damage to the environment can be significantly reduced by early action to locate, identify the extent, and remediate imminent hazards. The ERA is focusing specifically on the removal of carbon tetrachloride vapor from the soil column and protection of the groundwater in the 200 West Area. The VOC-Arid ID program allows demonstration of new drilling technologies for environmental characterization monitoring and remediation. Soil vapor vacuum extraction has been proposed to remediate the site. This may require vapor extraction wells to be installed within the plume.

  10. 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.

  11. Correlation of smoke development in room tests with cone calorimeter data for wood products

    Treesearch

    Mark A. Dietenberger; Ondrej. Grexa

    2000-01-01

    A direct proportionality has been found between the smoke extinction area (SEA) for smoke of room linings and the SEA as measured in the cone calorimeter (ISO5660). The room test scenario (ISO9705) considered was the propane ignition burner at the corner with a 100/300 kW program and the specimen lined on the walls only. The mixing of smoke from propane and lining...

  12. A 40-foot static cone penetrometer

    USGS Publications Warehouse

    Beard, R.M.; Lee, H.J.

    1982-01-01

    The Navy needs a lightweight device for testing seafloor soils to sub bottom depths of 12 meters in water depths to 60 meters. To meet this need a quasistatic cone penetration device that uses water jetting to reduce friction on the cone rod has been developed. This device is called the XSP-40. The 5-ton XSP-40 stands 15 meters tall and pushes a standard 5-ton cone into the seafloor. It is remotely controlled with an electronic unit on the deck of the support vessel. All cone outputs are recorded directly as a function of penetration depth with a strip chart recorder. A full suite of gauges is provided. on the electronic unit for monitoring the XSP-40's performance during a test .. About 40 penetration tests have been performed with very good success. The XSP-40 was field tested in Norton Sound, off the west coast of Alaska. The general objective, in addition to evaluation of the device, was to gather geotechnical information on sediments that may be involved in processes potentially hazardous to offshore development. Four example penetration records are presented from gas charged sediment zones and areas near the Yukon River delta. In general it was determined that soil classification from cone data agreed well with classifications from core samples. Relative densities of the silt-sand to sandy-silt soils were usually very high. The significance of these results are discussed with respect to storm wave, liquefaction. It is concluded that the XSP-40 is a durable and reliable piece of equipment capable of achieving penetration beyond that possible when not using the water jet system.

  13. 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

  14. Direct Laser Ice Penetrator for Exploring Icy Ocean Worlds: Design, Modeling and Test Results of a Proof-of-Concept Prototype

    NASA Astrophysics Data System (ADS)

    Hogan, B.; Stone, W.; Bramall, N. E.; Siegel, V.; Lelievre, S.; Rothhammer, B.; Richmond, K.; Flesher, C.

    2016-12-01

    Subsurface exploration of icy ocean worlds requires an efficient method of penetrating ice to significant depths under extreme environment conditions. Searching for extant life dictates descent to a depth which is habitable or where biomarkers can survive and allow detection. It's anticipated that several meters to 10s of meters of shielding is required to prevent cosmic background radiation and other energetic particles from destroying biomarker evidence. We have devised, developed and demonstrated an entirely novel ice penetrating technology utilizing laser light carried by an optical fiber tether and emitted from a probe's optical nose cone and radiated directly into the volume of ice preceding the penetrator. We have termed it a "Direct Laser Penetrator" or DLP. We present design details, modeling, and test data from preliminary proof-of-concept experiments conducted at Stone Aerospace with results exceeding expectations and achieving the fastest reported thermal probe descent rate to date (> 12 m / hr). DLP has critical benefits over conventional "hot point" melt probes, which must generate large temperature gradients to force heat by conduction through the nose cone, and layers of ice and water. Additionally, hot point melt probes tested under vacuum have shown extreme difficulty initiating penetration, as virtually no thermal contact exists between the probe nose and rough ice surface. The ice simply sublimates and any transferred heat is quickly dissipated due to the low power density and extreme cold. DLP requires NO thermal contact between the probe nose and the ice surface since the laser energy is radiated directly into the volume (vs. surface) of ice preceding the penetrator. A proposed key element of the DLP is the fiber optic tether, coupled with a dedicated sensor fiber, enables "optical access" to the subsurface environment by a lander's shared or DLP dedicated on-board instruments (Raman / Fluorescence / fiber / UV / VIS / NIR spectroscopy, etc

  15. 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

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

    PubMed

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

    2016-01-01

    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. 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. 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 $. Cone adaptation is a valid and cost-effective screening tool test for RP. The consanguinity rate among parents of an RP patient was high.

  17. A coning motion apparatus for hydrodynamic model testing in a non-planar cross-flow

    NASA Astrophysics Data System (ADS)

    Johnson, David C.

    1989-06-01

    As part of continuing research into the flow about slender bodies of revolution, a coning motion apparatus for hydrodynamic model testing was built and demonstrated. This is the first known use of a rotary balance apparatus for external flow hydrodynamic applications. The vorticity shed by the hull and appendages creates a wake field that interacts with the velocity distribution over the vehicle's surface. This in turn effects the surface pressure distribution and thus, when integrated over the body's surface, the total force on the hull/appendage combination. It is this interaction that prevents a closed-form analytic solution to the problem.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. A numerical test of a high-penetrability approximation for the one-dimensional penetrable-square-well model

    NASA Astrophysics Data System (ADS)

    Fantoni, Riccardo; Giacometti, Achille; Malijevský, Alexandr; Santos, Andrés

    2010-07-01

    The one-dimensional penetrable-square-well fluid is studied using both analytical tools and specialized Monte Carlo simulations. The model consists of a penetrable core characterized by a finite repulsive energy combined with a short-range attractive well. This is a many-body one-dimensional problem, lacking an exact analytical solution, for which the usual van Hove theorem on the absence of phase transition does not apply. We determine a high-penetrability approximation complementing a similar low-penetrability approximation presented in previous work. This is shown to be equivalent to the usual Debye-Hückel theory for simple charged fluids for which the virial and energy routes are identical. The internal thermodynamic consistency with the compressibility route and the validity of the approximation in describing the radial distribution function is assessed by a comparison against numerical simulations. The Fisher-Widom line separating the oscillatory and monotonic large-distance behaviors of the radial distribution function is computed within the high-penetrability approximation and compared with the opposite regime, thus providing a strong indication of the location of the line in all possible regimes. The high-penetrability approximation predicts the existence of a critical point and a spinodal line, but this occurs outside the applicability domain of the theory. We investigate the possibility of a fluid-fluid transition by the Gibbs ensemble Monte Carlo techniques, not finding any evidence of such a transition. Additional analytical arguments are given to support this claim. Finally, we find a clustering transition when Ruelle's stability criterion is not fulfilled. The consequences of these findings on the three-dimensional phase diagrams are also discussed.

  4. 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.

  5. 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.

  6. Soft Soil Tire Model Development and Experimental Testing

    DTIC Science & Technology

    2012-09-01

    A hand-held cone penetrometer is the used to measure the compaction versus sinkage. The moisture content is measure using a simple ASTM standard... cone pene- trometer, a California Bearing Ratio ( CBR ) test was administered to measure the relative resistance to penetration of the soil [43]. The...results of this data can be closely correlated with the cone penetration data obtained during testing in the Terramechanics rig.To investi- gate

  7. 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.

  8. 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.

  9. Foam Core Particleboards with Intumescent FRT Veneer: Cone Calorimeter Testing With Varying Adhesives, Surface Layer Thicknesses, and Processing Conditions

    Treesearch

    Mark A. Dietenberger; Johannes Welling; Ali Shalbafan

    2014-01-01

    Intumescent FRT Veneers adhered to the surface of foam core particleboard to provide adequate fire protection were evaluated by means of cone calorimeter tests (ASTM E1354). The foam core particleboards were prepared with variations in surface layer treatment, adhesives, surface layer thicknesses, and processing conditions. Ignitability, heat release rate profile, peak...

  10. 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

  11. 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.

  12. 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.

  13. Preliminary lightning tests: Optical fiber penetration of an exclusion region barrier

    SciTech Connect

    Dinallo, M.A. ); Fisher, R.J. )

    1992-08-01

    As part of the Direct Optical Initiation (DOI) program, an assessment of the possibility of introducing lightning energy into an exclusion region via an Optical Barrier Feedthrough (OBF) is being carried out. One postulated penetration mechanism is the tracking of current past the OBF on the surface of the dielectric optical fiber itself. During September and October of 1991, a series of tests was conducted on a closed metallic cylindrical test object representing the electrical exclusion region of a weapon. Median-level (30-kA) and severe (200-kA) simulated lightning return strokes, singly, doubly, and in combination with a moderate continuing current, were attached directly to the exterior portion of a fiber optic cable, which penetrated through a hole of controlled size into the interior of the exclusion region. The thickness of the barrier surrounding the hole was 0.06 in. Attempts were made to measure any conducted current flowing on the fiber at distances of 1 and 4 inches from the interior surface of the stainless steel top of the cylinder. Test parameter variations included diameter of the penetration hole (475 and 500 microns), length of the exterior portion of the cable and whether or not its jacket was present, and the applied test currents. It is concluded that no signal above measurement noise was recorded on any of the data shots that made up the test series. Measurement resolution was of the order of several amperes. Based on the highest recorded response of 8.5 A, corresponding to a 200-kA input, the OBF can be characterized by a direct-strike lightning attenuation factor of approximately 5 {times} lO{sup {minus}5} or better. Based on the more typically observed noise level of a few amps, the attenuation is commensurately greater.

  14. Development of a High-Velocity Powder Gun and Analysis of Fragment Penetration Tests into Sand

    DTIC Science & Technology

    1975-10-01

    support and shock absorber systems) 10 VA uu POR -. - -. LE T MUZZLE N FigLre Hih-veociy pwde gun(muzle VaCUM crt an A AMIN Figure 5. Hivciyty oWdhser gu...and more refined penetration tests and grain-size analyses, it would represent a significant advancement in the understanding of the energy exchange...Observations with Dynamic Yield Strengths of Fragment Materials and Energy Partitioning Considerations 38. Taylor’ has demonstrated that the profile of a

  15. 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.

  16. 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.

  17. 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.

  18. A Southwide Rate Test of Azinphosmethyl (Guthion®) for Cone and Seed Insect Control In Loblolly Pine Seed Orchards

    Treesearch

    A.C. Mangini; L.R. Barber; R.S. Cameron; G.L. DeBarr; G.R. Hodge; J.B. Jett; W.L. Lowe; J.L. McConnell; J. Nord; J.W. Taylor

    1998-01-01

    A southwide efficiency test of reduced rates of azinphosmethyl (Guthion®) for control of seed and cone insects in loblolly pine seed orchards was conducted in 1992. In each of nine loblolly pine (Pinus taeda L.) seed orchards, an untreated (no protection) check and two of five possible rates of Guthion® (1.0, 1.5, 2.0, 2.5, or 3.0 lb ai/ac/...

  19. 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

  20. 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 ...

  1. 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.

  2. Effect of the characteristics of granular media on dynamic penetration test - Numerical study using 2D - DEM

    NASA Astrophysics Data System (ADS)

    Tran, Quoc Anh; Chevalier, Bastien; Breul, Pierre

    2017-06-01

    The paper presents a numerical study on the influence of the properties of granular media on light dynamic penetration test results. A numerical model based on the Discrete Element Method (DEM) in 2 dimensions has been carried out. The model is able to reproduce the penetration tests in dynamic conditions. The model provide for each impact, the load-penetration curve that presents the evolution of reaction forces of granular media acting on the tip of the penetration test. The load - penetration curves are investigated in terms of tip resistance and analyzed by using the Discrete Fourier Transform in order to study the oscillations of the curves. The influence of the properties of granular media on the load-penetration curve has been investigated. We concentrated on the influence of particle friction and sample compacity. Besides the known results obtained in the literature by the dynamic tip resistance analysis for macroscopic response, we found that for a particle friction greater than 0.5, tip resistance and oscillations of signal are stable. Concerning the sample compacity, although variation of volume fraction is tight (ϕ = 0.817 - 0.844), a clear variation in terms of tip resistance and amplitude spectrum is highlighted.

  3. 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.

  4. Investigation of the sintering rate of snow with high-resolution penetration tests

    NASA Astrophysics Data System (ADS)

    Peinke, Isabel; Hagenmuller, Pascal; Chambon, Guillaume; Roulle, Jacques; Morin, Samuel

    2017-04-01

    Sintering in snow is very active due to a high homologous temperature and has a major effect on the evolution of the snow mechanical properties. We investigated the sintering rate of snow using high-resolution penetration tests performed with the Snow Micro Penetrometer (SMP) in a cold room at -10°C. To this end, we prepared several samples by sieving rounded grain snow with different sieve sizes (0.8, 1 and 1.6 mm) and conducted numerous SMP tests at different times during the first day of sintering. The SMP was modified such that only the measuring tip was in contact to the snow and we mounted three different tips with diameters of 4, 5 and 8 mm. The increase of the measured mean penetration resistance is shown to follow a power law whose exponent is defined as the sintering rate. The sintering rate mean value is about 0.25, which is consistent with values reported in the literature and it increases with specific surface area and depth. However, the sintering rate diminishes when SMP tip size increases, which is counterintuitive for a material property. An advanced analysis is thus required to extract relevant material properties, as the deflection at rupture, individual rupture force of bonds, and spatial intensity of rupture events, out of the SMP signal. A Poisson shot noise model [Löwe and Herwijnen 2012] was used, in which a depth-dependence of the parameters was assumed. The individual rupture force follows a power law with exponents around 0.3 with almost no dependency on the tip size. In comparison, the time evolution of intensity and deflection at rupture were negligible. This approach exploits the high-resolution of the SMP to give new insights on the sintering mechanisms in snow.

  5. 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)

  6. Possibilities of ground penetrating radar usage within acceptance tests of rigid pavements

    NASA Astrophysics Data System (ADS)

    Stryk, Josef; Matula, Radek; Pospisil, Karel

    2013-10-01

    Within the road pavement acceptance tests, destructive as well as non-destructive tests of individual road layers are performed to verify the standard requirements. The article describes a method for providing quick, effective and sufficiently accurate measurements of both dowel and tie bar positions in concrete pavements, using a two-channel ground penetrating radar (GPR). Measurements were carried out in laboratory and in-situ conditions. A special hand cart for field measurements, set for the testing requirements, was designed. It was verified that following the correct measuring and assessment method, it is possible to reach accuracy of determining the in-built rebar up to 1 cm in vertical direction and up to 1.5 cm per 11.5 m of measured length in horizontal direction. In the in-situ tests, GPR identification of possible anomalies due to the phase of concrete pavement laying was presented. In the conclusion, a measurement report is mentioned. The standard requirements for the position of dowels and tie bars cover maximum possible deviation of the rebar position from the project documentation in vertical and horizontal direction, maximum deflection of rebar ends to each other, and maximum translation of rebar in the direction of its longitudinal axis.

  7. 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.

  8. 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

  9. 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

  10. 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

  11. Phenomenological Investigation of Rapid Projectile Penetration in Granular Media

    NASA Astrophysics Data System (ADS)

    Omidvar, Mehdi

    There has been a recent flurry of research in rapid penetration into granular media, motivated by military and civilian applications including underground target penetration, design of fortifications, drilling for resource extraction, offshore foundations and anchors, probing of in situ mechanical properties, and study of high strain rate response of granular media, among others. The present study contributes to the state of the art in rapid penetration into granular media, by producing data at the macro and meso scales. In-house projectile accelerators are used to launch projectiles into laboratory scale physical models. The experimental program is divided into two sections. In the first section, penetration tests are performed at impact velocities in the range of 60-300 m/s. High-speed imaging and photonic Doppler velocimetry are used to record time history of penetration. In the second section, low velocity penetration tests are performed in refractive index matched transparent soils. Images are acquired form a mid plane within the sample. Digital image correlation is employed to describe granular kinematics. Macro scale test results point to the existence of at least two transition regimes in penetration resistance. The first, occurring at penetration velocities of approximately 60- 80 m/s, may be due the role of particle crushing, while the second is linked to frictional resistance dominating over inertial resistance at penetration velocities below approximately 15 m/s. It is also found that the role of nose shape is related to particle crushing. An attached false cone forms ahead of the projectile due to significant particle crushing, rendering nose shape effects less significant. Packing density and saturation are also found to affect penetration characteristics. Penetration tests in transparent soils reveal significant differences between quasi-static and dynamic penetration. Greater vertical displacements occur ahead of the projectile in dynamic

  12. Insulin Receptor Signaling in Cones*

    PubMed Central

    Rajala, Ammaji; Dighe, Radhika; Agbaga, Martin-Paul; Anderson, Robert E.; Rajala, Raju V.S.

    2013-01-01

    In humans, age-related macular degeneration and diabetic retinopathy are the most common disorders affecting cones. In retinitis pigmentosa (RP), cone cell death precedes rod cell death. Systemic administration of insulin delays the death of cones in RP mouse models lacking rods. To date there are no studies on the insulin receptor signaling in cones; however, mRNA levels of IR signaling proteins are significantly higher in cone-dominant neural retina leucine zipper (Nrl) knock-out mouse retinas compared with wild type rod-dominant retinas. We previously reported that conditional deletion of the p85α subunit of phosphoinositide 3-kinase (PI3K) in cones resulted in age-related cone degeneration, and the phenotype was not rescued by healthy rods, raising the question of why cones are not protected by the rod-derived cone survival factors. Interestingly, systemic administration of insulin has been shown to delay the death of cones in mouse models of RP lacking rods. These observations led to the hypothesis that cones may have their own endogenous neuroprotective pathway, or rod-derived cone survival factors may be signaled through cone PI3K. To test this hypothesis we generated p85α−/−/Nrl−/− double knock-out mice and also rhodopsin mutant mice lacking p85α and examined the effect of the p85α subunit of PI3K on cone survival. We found that the rate of cone degeneration is significantly faster in both of these models compared with respective mice with competent p85α. These studies suggest that cones may have their own endogenous PI3K-mediated neuroprotective pathway in addition to the cone viability survival signals derived from rods. PMID:23673657

  13. 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.

  14. Efficient three-dimensional data inversion: Soil characterization and moisture Monitoring from cross-well ground-penetrating radar at a Vermont Test Site

    NASA Astrophysics Data System (ADS)

    Eppstein, Margaret J.; Dougherty, David E.

    1998-08-01

    We extend our methodology for three-dimensional parameter structure and value estimation and apply it to a Vermont test site. Ground-penetrating radar (GPR) cross-well travel times are inverted for estimation of heterogeneous GPR soil velocities before and after a controlled release of salt water in the unsaturated zone. The method, which is based on an approximation of the extended Kaiman filter in conjunction with data-driven zonation, automatically estimates not only distributed zone values but also the number of zones, zone geometry, and zone covariance. Resultant GPR velocity estimates are shown to reduce travel time estimation errors and to be consistent with independent cone penetrometer measurements at all five walls at the site. Comparison of velocity estimates before and after forced injection of salt water is used to detect and visualize soil moisture patterns in three dimensions. By varying the "cluster tolerance criterion" in the data-driven zonation process, the user can obtain a desired resolution of heterogeneity (number of zones used) in the resultant model.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Cone Heads

    ERIC Educational Resources Information Center

    Coy, Mary

    2005-01-01

    The author, a middle school art teacher, describes a sculpture project lesson involving Cone Heads (sculptures made from cardboard cones). Discussion of caricatures with exaggerated facial features and interesting profiles helped students understand that the more expressive the face, the better. This project took approximately four to five…

  20. 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

  1. 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).

  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. Nuclear Technology. Course 26: Nondestructive Examination (NDE) Techniques I. Module 26-4, Liquid Penetrant Tests.

    ERIC Educational Resources Information Center

    Espy, John

    This fourth in a series of seven modules for a course titled Nondestructive Examination (NDE) Techniques I describes liquid penetrant examination which provides an effective method of detecting undesired, invisible surface discontinuities. The module follows a typical format that includes the following sections: (1) introduction, (2) module…

  4. Flow to partially penetrating wells in unconfined heterogeneous aquifers: Mean head and interpretation of pumping tests

    NASA Astrophysics Data System (ADS)

    Dagan, G.; Lessoff, S. C.

    2011-06-01

    A partially penetrating well of length Lw and radius Rw starts to pump at constant discharge Qw at t = 0 from an unconfined aquifer of thickness D. The aquifer is of random and stationary conductivity characterized by KG (geometric mean), σY2 (log conductivity variance), and I and Iv (the horizontal and vertical integral scales). The flow problem is solved under a few simplifying assumptions commonly adopted in the literature for homogeneous media: Rw/Lw ≪ 1, linearization of the free surface condition, and constant drainable porosity n. Additionally, it is assumed that Rw/I < 1 and Lw/Iv ≫ 1 (to simplify the well boundary conditions) and that a first-order approximation in σY2 (extended to finite σY2 on a conjectural basis) is adopted. The solution is obtained for the mean head field and the associated water table equation. The main result of the analysis is that the flow domain can be divided into three zones for : (1) the neighborhood of the well R ≪ I, where = (Qw/LwKA)h0(R, z, tKefuv/nD), with h0 being the zero-order solution pertaining to a homogeneous and isotropic aquifer, KA being the conductivity arithmetic mean, and Kefuv being the effective vertical conductivity in mean uniform flow, (2) an exterior zone R ⪆ I in which ?H? = (Qw/LwKefuh)h0(R?, z, tKefuv/nD), with Kefuh being the horizontal effective conductivity, and (3) an intermediate zone in which the solution requires a few numerical quadratures, not carried out here. The application to pumping tests reveals that identification of the aquifer parameters for homogeneous and anisotropic aquifers by commonly used methods can be applied for the drawdown measured in an observation well of length Low?Iv (to ensure exchange of space and ensemble head averages) in the second zone in order to identify Kefuh, Kefuv, and n. In contrast, the use of the drawdown in the well (first zone) leads to an overestimation of Kefuh by the factor KA/Kefuh.

  5. Polar Cone

    NASA Image and Video Library

    2006-07-10

    This MOC image shows a cone-shaped hill, perhaps a remnant of a material that was once more laterally extensive across the area, on a textured plain in the Hyperboreus Labyrinthus region in the north polar region of Mars

  6. 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.

  7. Development of a new test system to determine penetration of multi-walled carbon nanotubes through filtering facepiece respirators

    PubMed Central

    Vo, Evanly; Zhuang, Ziqing

    2015-01-01

    Carbon nanotubes (CNTs) are currently used in numerous industrial and biomedical applications. Recent studies suggest that workers may be at risk of adverse health effects if they are exposed to CNTs. A National Institute for Occupational Safety and Health (NIOSH) survey of the carbonaceous nanomaterial industry found that 77% of the companies used respiratory protection. Elastomeric half-mask respirators and filtering facepiece respirators (FFRs) are commonly used. Although numerous respirator filtration studies have been done with surrogate engineered nanoparticles, such as sodium chloride, penetration data from engineered nanoparticles such as CNTs are lacking. The aims of this study were to develop a new CNT aerosol respirator testing system and to determine multi-walled CNT (MWCNT) penetration through FFRs. A custom-designed CNT aerosol respirator testing system (CNT-ARTS) was developed which was capable of producing a sufficient amount of airborne MWCNTs for testing of high efficiency FFRs. The size distribution of airborne MWCNTs was 20–10,000 nm, with 99% of the particles between 25 and 2840 nm. The count median diameter (CMD) was 209 nm with a geometric standard deviation (GSD) of 1.98. This particle size range is similar to those found in some work environments (particles ≤6000 nm). The penetration of MWCNTs through six tested FFR models at two constant flow rates of 30 and 85 LPM was determined. Penetration at 85 LPM (0.58–2.04% for N95, 0.15–0.32% for N99, and 0.007–0.009% for P100 FFRs) was greater compared with the values at 30 LPM (0.28–1.79% for N95, 0.10–0.24% for N99, and 0.005–0.006% for P100 FFRs). The most penetrating particle size through all six tested FFR models was found to be in the range of 25–130 nm and 35–200 nm for the 30-LPM and 85-LPM flow rates, respectively. PMID:26166842

  8. 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.

  9. Accuracy of sperm-cervical mucus penetration tests in evaluating sperm motility in semen: a systematic quantitative review.

    PubMed

    Ola, Bolarinde; Afnan, Masoud; Papaioannou, Spyros; Sharif, Khaldoun; Björndahl, Lars; Coomarasamy, Aravinthan

    2003-05-01

    Our objective was to determine the accuracy of in-vitro sperm penetration into cervical mucus or substitutes in evaluating sperm motility in semen. This was a systematic quantitative review of test accuracy studies. The Cochrane library (2000:4), Medline (1966-2001), Embase (1988-2001) and SciSearch (1981-2001) were searched, in addition to manual searches of conference papers and bibliographies of known primary and review articles. Primary studies measuring in-vitro sperm penetration into cervical mucus, or substitutes (i.e. sperm-mucus penetration test, SMPT) and comparing results with sperm motility in semen were included. There were 18 primary diagnostic studies published in 17 papers, involving a total of 2580 samples. Fourteen primary diagnostic tests used vanguard distance as diagnostic criteria (SMPT(vd)) and the pooled likelihood ratio (LR) for positive (LR+) and negative (LR-) tests were 2.29 (1.82-2.87) and 0.52 (0.44-0.63) respectively. Four studies used diagnostic criteria based directly or indirectly on swim-up sperm count per high power field (SMPT(sc)) instead. Their pooled LR+ and LR- were 5.24 (3.36-8.18) and 0.15 (0.06-0.39) respectively. SMPT(vd) has a low accuracy in the evaluation of sperm motility in semen. However, SMPT(sc) was found to be more accurate. This method of using sperm concentration, instead of vanguard distance, as diagnostic criteria of in-vitro SMPT has potential as a useful laboratory-based sperm function test.

  10. 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)

  11. 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.

  12. Testing models for lithospheric thinning in the Puna Plateau, NW Argentina using alignment and morphology of young, mafic, monogenetic cinder cones

    NASA Astrophysics Data System (ADS)

    Calhoun, J. P.; Schoenbohm, L. M.

    2009-12-01

    New methods for measuring morphology and alignment of monogenetic cinder cones as a proxy for lithospheric stresses and the location and trend of feeder dikes have been applied to 47 late Miocene (~7Ma) to present mafic cones found on the world’s second highest continental plateau, the Puna plateau of northwest Argentina. Lithospheric thinning is believed to have occurred beneath the plateau; the analysis of spatial and temporal stress patterns recorded by the cinder cones will allow for testing among the proposed models which include delamination, full convective removal, partial convective removal, piecemeal removal, and back-arc extension. These methods were applied to cinder cones in the southern Puna (24°S -27°S, 69°W-66°W) in an attempt to better understand the state of the crust and the lithospheric mantle beneath the plateau. Linear arrays of monogenetic cinder cones can reflect the orientations of subsurface feeder dikes which form parallel to the maximum horizontal stress (SH) and thus lend insight into the state of stress in the lithosphere (Paulsen and Wilson, 2009, in press). Other cone features such as elongation, can also reflect lithospheric stress, and breaching direction can reflect the strike, dip, and sense of displacement of underlying faults (e.g. Tibaldi, JGR, 1995). Mapping of these features was carried out in ArcGIS using ASTER imagery, SRTM DEMs, Google Earth imagery, and was supplemented by field observations. Ellipses were systematically created in ArcGIS using the “Directional Distribution: Standard Deviational Ellipse” tool. A series of measurements and data on each cone ellipse were collected, including: axial ratios, length of long and short axis, elongation and breaching directions, and feature coordinates. Cone fields, defined as localized clusters of similarly aged cones, were analyzed for the number of vents, alignment lengths, standard deviation of vent centers from a best fit line, number of elongate vents, standard

  13. Operational evaluation of thunderstorm penetration test flights during project Storm Hazards '80

    NASA Technical Reports Server (NTRS)

    Keyser, G. L., Jr.; Deal, P. L.; Fisher, B. D.; Crabill, N. L.

    1981-01-01

    The National Aeronautics and Space Administration is conducting a research project called Storm Hazards '80 in order to study the prediction, detectability and avoidance of the hazards of severe storms for aircraft operations. The project, using a highly instrumented NASA F-106B airplane to penetrate thunderstorms, gathered and correlated data from both airborne and ground based instrumentation. The objectives of this project are to determine the effects of lightning on the design and operation of aircraft composite structures and digital electronic systems. The data will be used to determine the correlation of lightning hazards with other severe storm hazards, such as heavy precipitation, hail, turbulence and wind-shear, in order to develop an initial data base for use in design and avoidance. The NASA F-106B was equipped with a weather radar, stormscope, lightning measurement instrumentation and air sampling equipment. This paper will focus on the operational aspects of thunderstorm penetrations and the pilot techniques used to avoid the extremely hazardous portions of the storm such as the tornadoes and hail. It will deal with the effects of the storm elements on the aircraft hardware, avionics and the crew.

  14. 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

  15. 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.

  16. How empty is an empty loss cone?

    NASA Astrophysics Data System (ADS)

    Weissbein, Amir; Sari, Re'em

    2017-06-01

    We consider two-body relaxation in a spherical system with a loss cone. Considering two-dimensional angular momentum space, we focus on 'empty loss cone' systems, where the typical scattering during a dynamical time jd is smaller than the size of the loss cone jlc. As a result, the occupation number within the loss cone is significantly smaller than outside. Classical diffusive treatment of this regime predict exponentially small occupation number deep in the loss cone. We revisit this classical derivation of occupancy distribution of objects in the empty loss cone regime. We emphasize the role of the rare large scatterings and show that the occupancy does not decay exponentially within the loss cone, but it is rather flat, with a typical value ˜[(jd/jlc)]2ln -2(jlc/jmin ) compared to the occupation in circular angular momentum (where jmin is the smallest possible scattering). Implication are that although the loss cone for tidal break of Giants or binaries is typically empty, tidal events that occur significantly inside the loss cone (β ≳ 2) are almost as common as those with β ≅ 1, where β is the ratio between the tidal radius and the periastron. The probability for event with penetration factor >β decreases only as β-1 rather than exponentially. This effect has no influence on events characterized by full loss cone, such as tidal disruption event of ˜1 m⊙ main-sequence star.

  17. Symmetrical and asymmetrical separations about a yawed cone. [tests in the Ames 1.8 x 1.8 wind tunnel

    NASA Technical Reports Server (NTRS)

    Peake, D. J.; Owen, F. K.; Higuchi, H.

    1978-01-01

    Three dimensional flow separations about a circular cone were investigated in the Mach number range 0.6 - 1.8. The cone was tested in the Ames 1.8 by 1.8 m wind tunnel at Reynolds numbers based on the cone length from 4,500,000 to 13,500,000 under nominally zero heat transfer conditions. Results indicate that: (1) the lee-side separated flow develops from initially symmetrically disposed and near-conical separation lines at angle of incidence/cone semiangle equal to approximately 1, with the free shear layers eventually rolling up into tightly coiled vortices at all Mach numbers; (2) the onset of asymmetry of the lee-side separated flow about the mean pitch plane is sensitive to Mach number, Reynolds number, and the nose bluntness; and (3) as the Mach number is increased beyond 1.8, the critical angle of incidence for the onset of asymmetry increases until at about M = 2.75 there is no longer any significant side force development.

  18. Liquid penetrants

    NASA Technical Reports Server (NTRS)

    Pasley, R. L.

    1973-01-01

    Liquid-penetrant inspection is discussed for surface defects in solids. The principle advantages are considered to be its simplicity and economy. The techniques and penetrants are described along with the developers. Commercially available equipment is also described.

  19. 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

  20. 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.

  1. 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}.

  2. 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.

  3. 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.

  4. 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).

  5. Ground penetrating radar results at the Box Canyon Site - 1996 survey as part of infiltration test

    SciTech Connect

    Peterson, J.E. Jr.; Williams, K.H.

    1997-08-01

    This data report presents a discussion of the borehole radar tomography experiment conducted at Box Canyon, Idaho. Discussion concentrates on the survey methodology, data acquisition procedures, and the resulting tomographic images and interpretations. The entire geophysics field effort for FY96 centered around the collection of the borehole radar data within the inclined boreholes R1, R2, R3, and R4 before, during, and after the ponded infiltration experiment. The well pairs R1-R2, R2-R4, and R3-R4 comprised the bulk of the field survey; however, additional data were collected between vertical boreholes within and around the infiltration basin. The intent of the inclined boreholes was to allow access beneath the infiltration basin and to enhance the ability of the radar method to image both vertical and horizontal features where flow may dominate. This data report will concentrate on the inclined borehole data and the resulting tomograms. The borehole radar method is one in which modified ground penetrating radar antennas are lowered into boreholes and high frequency electromagnetic signals are transmitted through subsurface material to a receiving antenna. The transmitted signals may be represented as multiple raypaths crossing through the zone of interest. If sufficient raypaths are recorded, a tomographic image may be obtained through computer processing. The data normally recorded are signal amplitude versus time. The information extracted from such data includes the following: (a) the transit time which depends on the wave velocity, (b) the amplitude which depends on the wave attenuation, the dispersion which indicates a change in velocity and attenuation with frequency.

  6. 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.

  7. Influence of Penetration Rate and Indenter Diameter in Strength Measurement by Indentation Testing on Small Rock Specimens

    NASA Astrophysics Data System (ADS)

    Haftani, Mohammad; Bohloli, Bahman; Nouri, Alireza; Javan, Mohammad Reza Maleki; Moosavi, Mahdi; Moradi, Majid

    2015-03-01

    Indentation testing has been developed as an unconventional method to determine intact rock strength using small rock specimens within the size of drill cuttings. In previous investigations involving indentation testing, researchers have used different indenter stylus geometries, penetration rate (PR) and specimen sizes. These dissimilarities can restrict applications of this method for strength measurement and lead to non-comparable results. This paper investigates the influence of indenter diameter (ID) and PR on indentation indices for carbonate rocks to provide objective comparison and application of the existing correlations. As part of this research, several indentation tests were conducted using different IDs and PRs. The laboratory test results showed that indentation indices can be affected by ID while PR has only minor effect on the indentation indices. Thus, a normalizing function was presented to reduce the dependency of test results to ID. Verification of the findings with independent data confirms the suitability of the suggested normalizing function in determining the rock uniaxial compressive strength using testing data obtained from various IDs and PRs.

  8. 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

  9. 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

  10. Combustion characteristics of north-eastern USA vegetation tested in the cone calorimeter: invasive versus non-invasive plants

    Treesearch

    Alison C. Dibble; Robert H. White; Patricia K. Lebow

    2007-01-01

    In the north-eastern United States, invasive plants alter forest fuels, but their combustion characteristics are largely unknown. We assessed unground samples of foliage and twigs in the cone calorimeter for 21 non-invasive, native species, paired with 21 invasive species (18 non-native). Variables included sustained ignition, peak heat release rate, total heat release...

  11. 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.

  12. 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.

  13. 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.

  14. 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,…

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

    DTIC Science & Technology

    2015-03-01

    identifying vulnerabilities: reverse engineering, debugging, and fuzz testing. Publicly known exploits are also available from online databases such...settings, as either of the DHCP server may respond (causing a race condition). For this reason, we configured the router DHCP services to respond...attacker advertises their MAC address as the default gateway. In this case, the gateway is using the first available IP address in the subnetwork

  16. 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.

  17. 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.

  18. 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.

  19. Evaluation of liquefaction potential of soil based on standard penetration test using multi-gene genetic programming model

    NASA Astrophysics Data System (ADS)

    Muduli, Pradyut; Das, Sarat

    2014-06-01

    This paper discusses the evaluation of liquefaction potential of soil based on standard penetration test (SPT) dataset using evolutionary artificial intelligence technique, multi-gene genetic programming (MGGP). The liquefaction classification accuracy (94.19%) of the developed liquefaction index (LI) model is found to be better than that of available artificial neural network (ANN) model (88.37%) and at par with the available support vector machine (SVM) model (94.19%) on the basis of the testing data. Further, an empirical equation is presented using MGGP to approximate the unknown limit state function representing the cyclic resistance ratio (CRR) of soil based on developed LI model. Using an independent database of 227 cases, the overall rates of successful prediction of occurrence of liquefaction and non-liquefaction are found to be 87, 86, and 84% by the developed MGGP based model, available ANN and the statistical models, respectively, on the basis of calculated factor of safety (F s) against the liquefaction occurrence.

  20. 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.

  1. Peripherin-2 differentially interacts with cone opsins in outer segments of cone photoreceptors.

    PubMed

    Nguyen, O N Phuong; Böhm, Sybille; Gießl, Andreas; Butz, Elisabeth S; Wolfrum, Uwe; Brandstätter, Johann H; Wahl-Schott, Christian; Biel, Martin; Becirovic, Elvir

    2016-06-15

    Peripherin-2 is a glycomembrane protein exclusively expressed in the light-sensing compartments of rod and cone photoreceptors designated as outer segments (OS). Mutations in peripherin-2 are associated with degenerative retinal diseases either affecting rod or cone photoreceptors. While peripherin-2 has been extensively studied in rods, there is only little information on its supramolecular organization and function in cones. Recently, we have demonstrated that peripherin-2 interacts with the light detector rhodopsin in OS of rods. It remains unclear, however, if peripherin-2 also binds to cone opsins. Here, using a combination of co-immunoprecipitation analyses, transmission electron microscopy (TEM)-based immunolabeling experiments, and quantitative fluorescence resonance energy transfer (FRET) measurements in cone OS of wild type mice, we demonstrate that peripherin-2 binds to both, S-opsin and M-opsin. However, FRET-based quantification of the respective interactions indicated significantly less stringent binding of peripherin-2 to S-opsin compared to its interaction with M-opsin. Subsequent TEM-studies also showed less co-localization of peripherin-2 and S-opsin in cone OS compared to peripherin-2 and M-opsin. Furthermore, quantitative FRET analysis in acutely isolated cone OS revealed that the cone degeneration-causing V268I mutation in peripherin-2 selectively reduced binding to M-opsin without affecting the peripherin-2 interaction to S-opsin or rhodopsin. The differential binding of peripherin-2 to cone opsins and the mutant-specific interference with the peripherin-2/M-opsin binding points to a novel role of peripherin-2 in cones and might contribute to understanding the differential penetrance of certain peripherin-2 mutations in rods and cones. Finally, our results provide a proof-of-principle for quantitative FRET measurements of protein-protein interactions in cone OS. © The Author 2016. Published by Oxford University Press. All rights reserved. For

  2. µCT-3D visualization analysis of resin composite polymerization and dye penetration test of composite adaptation.

    PubMed

    Yoshikawa, Takako; Sadr, Alireza; Tagami, Junji

    2017-08-25

    This study evaluated the effects of the light curing methods and resin composite composition on composite polymerization contraction behavior and resin composite adaptation to the cavity wall using μCT-3D visualization analysis and dye penetration test. Cylindrical cavities were restored using Clearfil tri-S Bond ND Quick adhesive and filled with Clearfil AP-X or Clearfil Photo Bright composite. The composites were cured using the conventional or the slow-start curing method. The light-cured resin composite, which had increased contrast ratio during polymerization, improved adaptation to the cavity wall using the slow-start curing method. In the μCT-3D visualization method, the slow-start curing method reduced polymerization shrinkage volume of resin composite restoration to half of that produced by the conventional curing method in the cavity with adhesive for both composites. Moreover, μCT-3D visualization method can be used to detect and analyze resin composite polymerization contraction behavior and shrinkage volume as 3D image in the cavity.

  3. The Super-Cone

    ERIC Educational Resources Information Center

    Fülöp, Zsolt

    2009-01-01

    Using the concept of exploded and compressed numbers the author constructs the supercone which is able to turn upon the border of three dimensional space and breaks through it. The introduction of super-cone gives a possibility for students to see the properties of traditional cone while the super-cone is not a traditional cone. Moreover we show…

  4. Measurement of microstructure and eutectic penetration rate on irradiated metallic fuel after high-temperature heating test

    NASA Astrophysics Data System (ADS)

    Kim, June-Hyung; Cheon, Jin-Sik; Lee, Byoung-Oon; Kim, Jun-Hwan; Kim, Hee-Moon; Yoo, Boung-Ok; Jung, Yang-Hong; Ahn, Sang-Bok; Lee, Chan-Bock

    2017-05-01

    Microstructural development of irradiated U-10Zr fuel slug with T92 cladding specimen was examined after thermal exposure of 750 °C for 1 h. Optical microscopy, scanning electron microcopy and electron microprobe analysis were employed to examine the microstructure, constituent migration, and eutectic penetration. Migration phenomena of U, Zr, Fe, and Cr indicative of Soret effect was observed, and Nd lanthanide fission product was found at the eutectic melting region. Eutectic penetration was quantified and correlated to a thermal activation model with a good agreement. Compared to the previously reported eutectic penetration rates for the unirradiated U-10Zr fuel slug with FMS (Ferritic Martensitic Steel, HT9) cladding specimens, the eutectic penetration rate determined from this study for the irradiated fuel specimen was higher. This phenomenon can be caused by the effect of lanthanide fission product migration into fuel slug-cladding interface during irradiation, and lowering the eutectic threshold temperature for the irradiated fuel.

  5. 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.

  6. Normal Perceptual Sensitivity Arising From Weakly Reflective Cone Photoreceptors

    PubMed Central

    Bruce, Kady S.; Harmening, Wolf M.; Langston, Bradley R.; Tuten, William S.; Roorda, Austin; Sincich, Lawrence C.

    2015-01-01

    Purpose To determine the light sensitivity of poorly reflective cones observed in retinas of normal subjects, and to establish a relationship between cone reflectivity and perceptual threshold. Methods Five subjects (four male, one female) with normal vision were imaged longitudinally (7–26 imaging sessions, representing 82–896 days) using adaptive optics scanning laser ophthalmoscopy (AOSLO) to monitor cone reflectance. Ten cones with unusually low reflectivity, as well as 10 normally reflective cones serving as controls, were targeted for perceptual testing. Cone-sized stimuli were delivered to the targeted cones and luminance increment thresholds were quantified. Thresholds were measured three to five times per session for each cone in the 10 pairs, all located 2.2 to 3.3° from the center of gaze. Results Compared with other cones in the same retinal area, three of 10 monitored dark cones were persistently poorly reflective, while seven occasionally manifested normal reflectance. Tested psychophysically, all 10 dark cones had thresholds comparable with those from normally reflecting cones measured concurrently (P = 0.49). The variation observed in dark cone thresholds also matched the wide variation seen in a large population (n = 56 cone pairs, six subjects) of normal cones; in the latter, no correlation was found between cone reflectivity and threshold (P = 0.0502). Conclusions Low cone reflectance cannot be used as a reliable indicator of cone sensitivity to light in normal retinas. To improve assessment of early retinal pathology, other diagnostic criteria should be employed along with imaging and cone-based microperimetry. PMID:26193919

  7. 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.

  8. 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)

  9. 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.

  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. 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.

  12. 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

  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. 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.

  15. Post-test analysis of a piping penetration in a 1:6-scale model of a reinforced concrete containment building

    SciTech Connect

    Weatherby, J.R.

    1988-01-01

    An overpressurization experiment was conducted on a scale-model of a reinforced concrete containment building. The test was terminated at an internal pressure of 145 psig due to excessive leakage through tears that developed in the steel liner. Virtually all leakage occurred through a 22-inch tear that propagated along the edge of a thickened insert plate that surrounded a piping penetration. This paper describes the results of a post-test finite element analysis of this region. Results of the analysis, visual observations, and thickness measurements all indicate that the 22-inch tear initiated due to high strains near a stud anchor. The results of the analysis also suggest that a relatively simple analytical technique can be used to estimate the pressure at which tears will initiate near penetrations in lined containment structures made of reinforced concrete.

  16. Phenomena after meteoroid penetration of a bumper plate

    NASA Technical Reports Server (NTRS)

    Todd, F. C.

    1971-01-01

    The analysis of hypervelocity impact of particles on a detector in space, with flow and shock penetration through fluid, plastic, and elastic zones was studied. The original paper and computer program on this topic is presented. Improvements in the program for the study of the formation of a cone of debris are discussed. The truncated apex of the cone is at the hole formed by the penetration of an initially spherical rock through a thin plate. A solution for the penetration of the thin plate was sought.

  17. 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.

  18. 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

  19. 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

  20. 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

  1. 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

  2. Regeneration of Cone Photoreceptors when Cell Ablation Is Primarily Restricted to a Particular Cone Subtype

    PubMed Central

    Fraser, Brittany; DuVal, Michèle G.; Wang, Hao; Allison, W. Ted

    2013-01-01

    We sought to characterize the regenerated cells, if any, when photoreceptor ablation was mostly limited to a particular cone subtype. This allowed us to uniquely assess whether the remaining cells influence specification of regenerating photoreceptors. The ability to replace lost photoreceptors via stem cell therapy holds promise for treating many retinal degenerative diseases. Zebrafish are potent for modelling this because they have robust regenerative capacity emanating from endogenous stem cells, and abundant cone photoreceptors including multiple spectral subtypes similar to human fovea. We ablated the homolog of the human S-cones, the ultraviolet-sensitive (UV) cones, and tested the hypothesis that the photoreceptors regenerating in their place take on identities matching those expected from normal cone mosaic development. We created transgenic fish wherein UV cones can be ablated by addition of a prodrug. Thus photoreceptors developed normally and only the UV cones expressed nitroreductase; the latter converts the prodrug metronidazole to a cell-autonomous neurotoxin. A significant increase in proliferation of progenitor cell populations (p<0.01) was observed when cell ablation was primarily limited to UV cones. In control fish, we found that BrdU primarily incorporated into rod photoreceptors, as expected. However the majority of regenerating photoreceptors became cones when retinal cell ablation was predominantly restricted to UV cones: a 2-fold increase in the relative abundance of cones (p = 0.008) was mirrored by a 35% decrease in rods. By primarily ablating only a single photoreceptor type, we show that the subsequent regeneration is biased towards restoring the cognate photoreceptor type. We discuss the hypothesis that, after cone death, the microenvironment formed by the remaining retinal cells may be influential in determining the identity of regenerating photoreceptors, though other interpretations are plausible. Our novel animal model provides

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Cone visual pigments.

    PubMed

    Imamoto, Yasushi; Shichida, Yoshinori

    2014-05-01

    Cone visual pigments are visual opsins that are present in vertebrate cone photoreceptor cells and act as photoreceptor molecules responsible for photopic vision. Like the rod visual pigment rhodopsin, which is responsible for scotopic vision, cone visual pigments contain the chromophore 11-cis-retinal, which undergoes cis-trans isomerization resulting in the induction of conformational changes of the protein moiety to form a G protein-activating state. There are multiple types of cone visual pigments with different absorption maxima, which are the molecular basis of color discrimination in animals. Cone visual pigments form a phylogenetic sister group with non-visual opsin groups such as pinopsin, VA opsin, parapinopsin and parietopsin groups. Cone visual pigments diverged into four groups with different absorption maxima, and the rhodopsin group diverged from one of the four groups of cone visual pigments. The photochemical behavior of cone visual pigments is similar to that of pinopsin but considerably different from those of other non-visual opsins. G protein activation efficiency of cone visual pigments is also comparable to that of pinopsin but higher than that of the other non-visual opsins. Recent measurements with sufficient time-resolution demonstrated that G protein activation efficiency of cone visual pigments is lower than that of rhodopsin, which is one of the molecular bases for the lower amplification of cones compared to rods. In this review, the uniqueness of cone visual pigments is shown by comparison of their molecular properties with those of non-visual opsins and rhodopsin. This article is part of a Special Issue entitled: Retinal Proteins - You can teach an old dog new tricks. © 2013 Elsevier B.V. All rights reserved.

  8. 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.

  9. Design and development testing of the bonded joint between a typical launch vehicle attachment ring and CFRP thrust cone

    NASA Astrophysics Data System (ADS)

    Sharkey, J. T.; Nayler, G. H. F.; Reynolds, J.

    1986-02-01

    The development of the principal structural joint of a Shuttle payload is described. The joint is subjected to large tension and compression loads due to the spacecraft being cantilevered perpendicular to the direction of flight of the launch vehicle. Finite element modeling was included in the investigation of joint designs. A bonded and bolted double lap shear configuration was chosen. Manufacturing and inspection methods were developed and testing of joint samples was undertaken including static, thermal and fatigue loading. The static test results were used to determine the design allowable strength of the joint.

  10. 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.

  11. 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.

  12. Spectrophotometric Evaluation of Potassium Nitrate Penetration Into the Pulp Cavity.

    PubMed

    Kwon, S R; Dawson, D V; Schenck, D M; Fiegel, J; Wertz, P W

    2015-01-01

    The aim of this study was to evaluate the penetration level of potassium nitrate-containing desensitizers or whitening materials into the pulp cavity with regard to the concentration and viscosity of the formulation. Fifty extracted human molar teeth were prepared and randomized into five groups of 10 specimens each. The control received a 30-minute treatment without any treatment material; the other four groups corresponded to treatment with DayWhite, a 14% hydrogen peroxide whitening material containing potassium nitrate; PreviDent 5000 Sensitive, a desensitizing toothpaste; Relief ACP, a desensitizing gel; or UltraEZ, a desensitizing gel. Potassium nitrate penetration levels were measured spectrophotometrically based on the Griess assay method. Treatment materials were measured for viscosity as a function of shear rate through the use of a cone-and-plate rheometer. Nitrate penetration levels were significantly different among the five groups (p<0.0001, Kruskal-Wallis test). After adjustment for multiple comparisons using an overall 0.05 level of type I error, the distribution of nitrate penetration values was found to differ significantly among all groups with the exception of DayWhite (median: 10.72 μM) and UltraEZ (median: 9.22 μM), which differed significantly from other groups but not from each other. The highest levels of nitrate penetration value were observed for PreviDent (median: 27.61 μM) followed by Relief ACP (median: 19.64 μM). The lowest penetration level was observed for the control group (median: 3.41 μM). Stable end-point viscosities of 11.43 ± 0.67 Pa/s, 1.33 ± 0.06 Pa/s, 0.85 ± 0.09 Pa/s, and 0.40 ± 0.01 Pa/s were observed for UltraEZ, ReliefACP, DayWhite, and PreviDent, respectively. Potassium nitrate included in different formulations can penetrate the enamel and dentin within 30 minutes. The level of potassium nitrate penetration is influenced by concentration and may also be partly affected by the viscosity of the material as well

  13. 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

  14. Modal content of living human cone photoreceptors.

    PubMed

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

    2015-09-01

    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.

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. Cone sampling array models

    NASA Technical Reports Server (NTRS)

    Ahumada, Albert J., Jr.; Poirson, Allen

    1987-01-01

    A model is described for positioning cones in the retina. Each cone has a circular disk of influence, and the disks are tightly packed outward from the center. This model has three parameters that can vary with eccentricity: the mean radius of the cone disk, the standard deviation of the cone disk radius, and the standard deviation of postpacking jitter. Estimates for these parameters out to 1.6 deg are found by using measurements reported by Hirsch and Hylton (1985) and Hirsch and Miller (1987) of the positions of the cone inner segments of an adult macaque. The estimation is based on fitting measures of variation in local intercone distances, and the fit to these measures is good.

  20. 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.

  1. 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.

  2. 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.

  3. [Retrograde obturation with MTA Cement and Super-EBA after apicoectomy. Sealing ability of MTA and Super-EBA in dye penetration tests].

    PubMed

    Schultz, Christoph B; Westhauser, Patrick; Nideröst, Beatrice; Klaus, W Grätz

    2005-01-01

    The present in vitro study investigated the sealing of retrograde fillings compounded of two different cements in consideration of cracking after root-end preparation of resected dental roots using diamond-coated ultrasonic retrotips. Root-end cavities were prepared in 32 resected roots using diamond-coated ultrasonic retrotips. The samples were divided into two groups. The first group was filled using zinc-oxide cement (Super-EBA-Cement), the second with mineral-trioxide-aggregate (Pro Root MTA). After resection, root-end preparation and retrograde filling, the samples were analysed using macro-zoom photography and scanning electron microscopy. The sealing quality of the filling materials was detected through dye penetration test. The average degree of penetration of the samples filled with Super-EBA-Cement was 2.19 and of the samples filled with Pro Root MTA 0.44 respectively. Accordingly the sealing of Pro Root MTA in vitro is superior to the sealing of Super-EBA-Cement. Retrograde conditioning of resected roots with ultrasonic retrotips represents an efficient and sparing alternative to conventional root-end preparation techniques.

  4. 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.

  5. 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.

  6. The color cone.

    PubMed

    Logvinenko, Alexander D

    2015-02-01

    While the notion of a color cone can be found in writings of Maxwell, Helmholtz, Grassmann, and other scientists of the nineteenth century, it has not been clearly defined as yet. In this paper, the color cone is understood as the set of points in the cone excitation space produced by all possible lights. The spectral curve representing all the monochromatic lights is shown not to entirely belong to the color cone boundary, since its ends turn into the color cone interior. The monochromatic lights represented by the fragment of the spectral curve lying on the color cone boundary make up what is called the effective visible spectrum. The color cone is shown to be a convex hull of the conical surface through the fragment of the spectral curve representing the effective visible spectrum. The effective visible spectrum ends are shown to be determined by the photopigment spectral absorbance being independent of the prereceptor filters (e.g., the spectral transmittance of the lense and macular pigment).

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

    PubMed

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

    2012-07-01

    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. 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. 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. 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.

  8. 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

  9. 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.

  10. 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.

  11. Prevalence and correlates of receiving and sharing high-penetrance cancer genetic test results: Findings from the Health Information National Trends Survey

    PubMed Central

    Taber, Jennifer M.; Chang, Christine Q.; Lam, Tram Kim; Gillanders, Elizabeth M.; Hamilton, Jada G.; Schully, Sheri D.

    2015-01-01

    Background/Aims The aim of this study was to explore the prevalence and correlates of receiving and sharing high-penetrance cancer genetic test results. Methods Participants completed the population-based, cross-sectional 2013 Health Information National Trends Survey. We examined sociodemographic characteristics of participants reporting having had BRCA1/2 or Lynch syndrome genetic testing, and sociodemographic and psychosocial correlates of sharing test results with health professionals and family members. Results Participants who underwent BRCA1/2 or Lynch syndrome genetic testing (n=77; 2.42% of respondents) were more likely to be female and to have a family or personal cancer history than those not undergoing testing. Approximately three-quarters of participants shared results with health professionals and three-quarters with their family; only 4% did not share results with anyone. Participants who shared results with health professionals reported greater optimism, self-efficacy for health management, and trust in information from their doctors. Participants who shared results with family were more likely to be female and to have a personal cancer history, and had greater self-efficacy for health management, perceived less ambiguity in cancer prevention recommendations, and lower cancer prevention fatalism. Conclusions We identified several novel psychosocial correlates of sharing genetic information. Health professionals may use this information to identify patients less likely to share information with at-risk family members. PMID:25427996

  12. 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.

  13. Scalable Asset Discovery, Vulnerability Scanning, and Penetration Testing for Remote Sites and Wireless Spectrums Utilizing an Embedded Linux Plug - PwniPlug and the Raspberry Pi B+ as a Sample Pen Test

    NASA Technical Reports Server (NTRS)

    Ganzy, Ethan G.

    2014-01-01

    All devices attached to the NASA KSC network are subject to security vulnerability scanning and/or penetration testing. In today's changing environment, vulnerable and/or unprotected systems can easily be overlooked. Systems that are not properly managed can become a potential threat to the operational integrity of our systems and networks. This includes all NASA (internal and external) information systems within NASA KSC Internet Protocol (IP) address space, and NASA KSC facilities. The Office of the Chief Information Officer (OCIO) recommends that all NASA Centers and information systems be subject to penetration testing on a regular interval in accordance with the guidelines identified by the National Institute of Standards and Technology (NIST). (ITS-HBK-2810.04-02A) Protecting information and equipment at NASA is an area of increasing concern. In addition to the CPU's on the network; Supervisory, Control and Data Acquisition (SCADA) systems are especially vulnerable because these systems have lacked standards, use embedded controllers with little computational power and informal software, are connected to physical processes, have few operators, and are increasingly also being connected to corporate networks. The scope of work is comprised of several individual components which together build upon previous work by Drew Branch, NASA KSC Intern. The Pwn Plug is the selected COTS (Commercial-Off-The-Shelf) device chosen to test simplification of mandatory IT Security tasks. The device will be utilized to provide services to NASA KSC and enable an assessment of infrastructure soundness and regulatory compliance in an efficient, economical, and business responsive manner. The Pwn Plug is designed as a pen testing appliance which provides a hardware platform that can support commercial penetration testing efforts at significantly reduced costs. The expected outcomes are: 1) External Penetration Testing, 2) Social Engineering, 3) Procedural Documentation, 4

  14. 2017 Eclipse Shadow Cones

    NASA Image and Video Library

    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...

  15. 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

  16. Technical Analysis and Characterization of Southern Cayo, Belize for Tropical Testing and Evaluation of Foliage Penetration Remote Sensing Systems

    DTIC Science & Technology

    2011-05-01

    34 (actually mainly sedges). Savanna is maintained as open vegetation by a combination of wet-season flooding, dry-season drought and fire . Typical trees...bark, covered up and colored by lichens growing on the surface. Vascular plant species, including trees, are identified to species according to their...all munitions firing must be conducted on ranges approved for all safety standards. Testing of smokes and obscurants requires a relatively flat area

  17. Cement penetration after patella venting.

    PubMed

    Jones, Christopher W; Lam, Li-On; Butler, Adam; Wood, David J; Walsh, William R

    2009-01-01

    There is a high rate of patellofemoral complications following total knee arthroplasty. Optimization of the cement-bone interface by venting and suction of the tibial plateau has been shown to improve cement penetration. Our study was designed to investigate if venting the patella prior to cementing improved cement penetration. Ten paired cadaver patellae were allocated prior to resurfacing to be vented or non-vented. Bone mineral density (BMD) was measured by DEXA scanning. In vented specimens, a 1.6 mm Kirschner wire was used to breach the anterior cortex at the center. Specimens were resurfaced with standard Profix instrumentation and Versabond bone cement (Smith and Nephew PLC, UK). Cement penetration was assessed from Faxitron and sectioned images by a digital image software package (ImageJ V1.38, NIH, USA). Wilcoxon rank sum test was used to assess the difference in cement penetration between groups. The relationship between BMD and cement penetration was analyzed by Pearson correlation coefficient. There was a strong negative correlation between peak BMD and cement penetration when analyzed independent of experimental grouping (r(2)=-0.812, p=0.004). Wilcoxon rank sum testing demonstrated no significant difference (rank sum statistic W=27, p=0.579) in cement penetration between vented (10.53%+/-4.66; mean+/-std dev) and non-vented patellae (11.51%+/-6.23; mean+/-std dev). Venting the patella using a Kirschner wire does not have a significant effect on the amount of cement penetration achieved in vitro using Profix instrumentation and Versabond cement.

  18. 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

  19. 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.

  20. Dentinal Tubule Penetration of Tricalcium Silicate Sealers.

    PubMed

    McMichael, Greer E; Primus, Carolyn M; Opperman, Lynne A

    2016-04-01

    The treatments for which mineral trioxide aggregate (MTA)-based materials can be used in dentistry are expanding. Smaller particle size and easier handling properties have allowed the advent of tricalcium silicate sealers including EndoSequence BC Sealer (Brasseler USA, Savannah, GA), QuickSet2 (Avalon Biomed, Bradenton, FL), NeoMTA Plus (Avalon Biomed), and MTA Fillapex (Angelus, Londrina, Brazil). The objective of this study was to measure the tubule penetration with these sealers using continuous wave (CW) and single-cone (SC) obturation techniques. Eighty single-rooted teeth were randomly divided into 8 groups of 10 and obturated with 1 of the previously mentioned sealers mixed with trace amounts of rhodamine using either the CW or SC technique. Teeth were sectioned at 1 mm and 5 mm from the apex and examined under a confocal laser microscope. The percentage of sealer penetration and the maximum sealer penetration were measured. The tricalcium silicate sealers penetrated tubules as deep as 2000 μm (2 mm). The percentage of sealer penetration was much higher 5 mm from the apex, with many specimens having 100% penetration for both SC and warm vertical techniques. MTA Fillapex, a resin-based sealer with less than 20% MTA particles, had significantly greater tubule penetration with a warm vertical technique versus the SC technique at the 1-mm level. Within the limitations of this study, the CW and SC techniques produced similar tubule penetration at both the 1-mm and the 5-mm level with the tricalcium silicate sealers BC Sealer, QuickSet2, and NeoMTA Plus. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. Lunar regolith penetrators and cutters

    NASA Technical Reports Server (NTRS)

    Barnes, Frank; Sture, Stein

    1991-01-01

    An apparatus was designed and built for conducting simulation experiments on cutting tool penetration in the centrifuge. This equipment is mounted on the laminar container which is used for the regolith densification study, so that the end product of the latter, i.e., a regolith bed with the proper density profile, can be used directly for the penetration tests. In this apparatus, an etching tool is suspended through a pulley system by the action of a double acting air cylinder. By adjusting the air pressure acting on each side of the cylinder, the net downward force acting on the tool can be controlled. The penetration of the tool is measured by an LVDT. This apparatus was proof-tested in the centrifuge and is ready for use in conjunction with the regolith densification experiments.

  6. Shatter Cones: (Mis)understood?

    NASA Astrophysics Data System (ADS)

    Osinski, G. R.; Ferrière, L.

    2016-08-01

    In this study we provide new observations of shatter cones from several complex impact craters in various target rocks and in different preservation states. We show that shatter cones are present in several stratigraphic settings.

  7. Water penetration study

    NASA Technical Reports Server (NTRS)

    Lockwood, H. E.

    1973-01-01

    Nine film-filter combinations have been tested for effectiveness in recording water subsurface detail when exposed from an aerial platform over a typical water body. 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 an infrared film with selected filters were tested. Results have been tabulated to show the relative capability of each film-filter combination for: (1) image contrast in shallow water (0 to 5 feet); (2) image contrast at medium depth (5 to 10 feet); (3) image contrast in deep water (10 feet plus); (4) water penetration; maximum depth where detail was discriminated; (5) image color (the spectral range of the image); (6) vegetation visible above a water background; (7) specular reflections visible from the water surface; and (8) visual compatibility; ease of discriminating image detail. Recommendations for future recording over water bodies are included.

  8. Test Results of Earth Penetrators

    DTIC Science & Technology

    1977-11-01

    in an aluminum mold shown in Figure 3 using dummy projectiles as shown. All of the projectiles had their centers of gravity 45 percent of the length...break wire on the muzzle of the gun and each of two aluminum foil switches, one on each side of a sabot stripper. Two photographic stations were...locate the center-of-gravity of the pro- jectiles at the desired point, it was necessary to use tungsten noses and aluminum afterbodies. The noses were

  9. 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.

  10. 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.

  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. 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.

  13. 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.

  14. 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.

  15. Reconstruction from cone integral transforms

    NASA Astrophysics Data System (ADS)

    Palamodov, Victor

    2017-10-01

    The paper contains new reconstruction formulas for a function on 3D space from data of its cone integrals with fixed opening and integrable weight. In the case of cone integrals with the (non integrable) weight modelling photometric law, a reconstruction is obtained for the non redundant data of cones with the apex running on a curve.

  16. FAA fluorescent penetrant activities

    SciTech Connect

    Moore, D.G.; Larson, B.F.

    1997-11-01

    The Federal Aviation Administration`s Airworthiness Assurance NDI Validation Center (AANC) and the Center for Aviation Systems Reliability (CASR) are currently working to develop a liquid penetrant inspection (LPI) system evaluation capability that will support the needs of the penetrant manufacturers, commercial airline industry and the FAA. The main focus of this facility is to support the evaluation of penetrant inspection materials, penetrant systems and to apply resources to support industry needs. This paper discusses efforts to create such a facility and an initial project to produce fatigue crack specimens for evaluation of Type 1 penetrant sensitivities.

  17. Cone on Olympus Mons

    NASA Image and Video Library

    2005-10-24

    This image from NASA 2001 Mars Odyssey spacecraft shows just a small part of the eastern flank of Olympus Mons. On the far left side of the image a small volcanic cone can be seen. The shadow helps to identify this feature.

  18. 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

  19. Shatter cones formed in large-scale experimental explosion craters

    NASA Technical Reports Server (NTRS)

    Roddy, D. J.; Davis, L. K.

    1977-01-01

    In 1968, a series of 0.5-ton and 100-ton TNT explosion experiments were conducted in granitic rock near Cedar City, Utah, as part of a basic research program on cratering and shock wave propagation. Of special interest was the formation of an important type of shock metamorphic feature, shatter cones. A description is presented of the first reported occurrence of shatter cones in high explosion trials. A background to shatter cone studies is presented and attention is given to the test program, geology and physical properties of the test medium, the observed cratering, and the formational pressures for shatter cones. The high explosion trials conducted demonstrate beyond any doubt, that shatter cones can be formed by shock wave processes during cratering and that average formational pressures in these crystalline rocks are in the 20-60 kb range.

  20. 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.

  1. Yearly rates of rod and cone functional loss in retinitis pigmentosa and cone-rod dystrophy.

    PubMed

    Birch, D G; Anderson, J L; Fish, G E

    1999-02-01

    To provide the first measures of the relative rates of rod and cone functional loss in patients with retinitis pigmentosa (RP) or cone-rod dystrophy (CRD). Five-year, prospective natural history study. Ninety-six patients (67 with RP and 29 with CRD) retaining measurable rod-mediated visual function and 5 normal subjects were tested at baseline and annually for 4 consecutive years. Tests of visual function included visual acuity, dark-adaptation thresholds, dark-adapted static perimetry, and rod and cone computer-averaged electroretinograms (ERGs), which were obtained over a range of retinal illuminances. Intervisit variability for each measure was obtained in a subset of patients who were tested twice within a 2-month interval and was used to determine whether an individual patient had shown progression, regression, or no change over a particular study interval. Over a 4-year interval, a significant number of patients with RP (60%) and CRD (62%) showed a decline in cone ERG amplitude. For rod ERG amplitude, the percentage of patients with RP or CRD showing progression was 64% and 45%, respectively. Although visual acuity, dark-adapted threshold, and rod visual field area also declined significantly over the 4-year period, the mean rate of change and the numbers of patients showing progression on these measures were lower than those for ERG measures. On specialized ERG testing, the yearly change in rod ERG threshold in RP was greater than the yearly change in cone ERG threshold, and the rate of progression varied significantly among inheritance types. For patients with CRD, the yearly change in rod threshold was comparable to the yearly change in cone ERG threshold. This study helps to define the natural progression of rod-mediated and cone-mediated functional loss in patients with RP and CRD.

  2. 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.

  3. Efinaconazole 10% and Tavaborole 5% Penetrate Across Poly-ureaurethane 16%: Results of In Vitro Release Testing and Clinical Implications of Onychodystrophy in Onychomycosis.

    PubMed

    Adigun, Chris G; Vlahovic, Tracey C; McClellan, Michael B; Thakker, Kailas D; Klein, Ryan R; Elstrom, Tuan A; Ward, Daniel B

    2016-09-01

    Poly-ureaurethane has been previously described for the management of dry, brittle, and in general, dystrophic nails. The polymer yields a waterproof, breathable barrier to protect the nail plate and prevent further damage to the nail, while regulating transonychial water loss (TOWL). Because nail dystrophy and dessication are contributing factors to onychomycosis, a barrier that protects the nail but also allows a topical antifungal to permeate its shield is potentially an advantageous combination. Oral antifungals such as terbinafine, itraconazole, and fluconazole, as well as the newer topical antifungals efinaconazole and tavaborole (although formulated to penetrate the nail unit and work with the porosity and inherent electrical charge of the nail plate), do not take into account nail damage that has been created from years of harboring a dermatophyte infection. Up to 50% of cases presumed to be onychomycosis are in fact onychodystrophy without fungal infection, and laboratory testing for fungus should be obtained prior to initiating antifungal treatment. Whether a nail has onychomycosis, or onychodystrophy due to other causes, barrier function and structural integrity are compromised in diseased nails, and should be addressed. A poly-ureaurethane barrier that protects against wetting/drying, fungal reservoirs, and microtrauma, followed by the addition of oral or topical antifungals after laboratory fungal confirmation may optimize outcomes in the treatment of onychomycosis.
    The purpose of this work was to determine through in vitro release testing (IVRT) whether poly-ureaurethane 16% allows for penetration of efinaconazole 10% or tavaborole 5%. Results could spur subsequent clinical studies which would have implications for the addition of an antifungal based on fungal confirmation, after addresssing the underlying nail dystrophy primarily.
    A vertical diffusion cell system was used to evaluate the ability of efinaconazole 10% and tavaborole 5% to

  4. 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.

  5. 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.

  6. Mitochondria Maintain Distinct Ca(2+) Pools in Cone Photoreceptors.

    PubMed

    Giarmarco, Michelle M; Cleghorn, Whitney M; Sloat, Stephanie R; Hurley, James B; Brockerhoff, Susan E

    2017-02-22

    Ca(2+) ions have distinct roles in the outer segment, cell body, and synaptic terminal of photoreceptors. We tested the hypothesis that distinct Ca(2+) domains are maintained by Ca(2+) uptake into mitochondria. Serial block face scanning electron microscopy of zebrafish cones revealed that nearly 100 mitochondria cluster at the apical side of the inner segment, directly below the outer segment. The endoplasmic reticulum surrounds the basal and lateral surfaces of this cluster, but does not reach the apical surface or penetrate into the cluster. Using genetically encoded Ca(2+) sensors, we found that mitochondria take up Ca(2+) when it accumulates either in the cone cell body or outer segment. Blocking mitochondrial Ca(2+) uniporter activity compromises the ability of mitochondria to maintain distinct Ca(2+) domains. Together, our findings indicate that mitochondria can modulate subcellular functional specialization in photoreceptors.SIGNIFICANCE STATEMENT Ca(2+) homeostasis is essential for the survival and function of retinal photoreceptors. Separate pools of Ca(2+) regulate phototransduction in the outer segment, metabolism in the cell body, and neurotransmitter release at the synaptic terminal. We investigated the role of mitochondria in compartmentalization of Ca(2+) We found that mitochondria form a dense cluster that acts as a diffusion barrier between the outer segment and cell body. The cluster is surprisingly only partially surrounded by the endoplasmic reticulum, a key mediator of mitochondrial Ca(2+) uptake. Blocking the uptake of Ca(2+) by mitochondria causes redistribution of Ca(2+) throughout the cell. Our results show that mitochondrial Ca(2+) uptake in photoreceptors is complex and plays an essential role in normal function. Copyright © 2017 the authors 0270-6474/17/372061-12$15.00/0.

  7. 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

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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).

  16. 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).

  17. 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.

  18. Cone rod dystrophies

    PubMed Central

    Hamel, Christian P

    2007-01-01

    Cone rod dystrophies (CRDs) (prevalence 1/40,000) are inherited retinal dystrophies that belong to the group of pigmentary retinopathies. CRDs are characterized by retinal pigment deposits visible on fundus examination, predominantly localized to the macular region. In contrast to typical retinitis pigmentosa (RP), also called the rod cone dystrophies (RCDs) resulting from the primary loss in rod photoreceptors and later followed by the secondary loss in cone photoreceptors, CRDs reflect the opposite sequence of events. CRD is characterized by primary cone involvement, or, sometimes, by concomitant loss of both cones and rods that explains the predominant symptoms of CRDs: decreased visual acuity, color vision defects, photoaversion and decreased sensitivity in the central visual field, later followed by progressive loss in peripheral vision and night blindness. The clinical course of CRDs is generally more severe and rapid than that of RCDs, leading to earlier legal blindness and disability. At end stage, however, CRDs do not differ from RCDs. CRDs are most frequently non syndromic, but they may also be part of several syndromes, such as Bardet Biedl syndrome and Spinocerebellar Ataxia Type 7 (SCA7). Non syndromic CRDs are genetically heterogeneous (ten cloned genes and three loci have been identified so far). The four major causative genes involved in the pathogenesis of CRDs are ABCA4 (which causes Stargardt disease and also 30 to 60% of autosomal recessive CRDs), CRX and GUCY2D (which are responsible for many reported cases of autosomal dominant CRDs), and RPGR (which causes about 2/3 of X-linked RP and also an undetermined percentage of X-linked CRDs). It is likely that highly deleterious mutations in genes that otherwise cause RP or macular dystrophy may also lead to CRDs. The diagnosis of CRDs is based on clinical history, fundus examination and electroretinogram. Molecular diagnosis can be made for some genes, genetic counseling is always advised. Currently

  19. 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.

  20. 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.

  1. Thermomechanics of Impact & Penetration

    DTIC Science & Technology

    2005-09-30

    metallic projectiles into granular targets, at high striking velocities, formulate appropriate constitutive models , and solve selected problems by...constitutive models (preliminary work only) * Multiscale Numerical Simulations (preliminary work) PROGRESS Time-Dependent Penetration Path of...theory. A dislocation based plasticity model was also developed for the impact and penetration analysis. Numerical solutions were presented for selected

  2. 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

  3. Formation of shatter cones in MEMIN impact experiments

    NASA Astrophysics Data System (ADS)

    Wilk, J.; Kenkmann, T.

    2016-08-01

    Shatter cones are the only macroscopic feature considered as evidence for shock metamorphism. Their presence is diagnostic for the discovery and verification of impact structures. The occurrence of shatter cones is heterogeneous throughout the crater record and their geometry can diverge from the typical cone shape. The precise formation mechanism of shatter cones is still not resolved. In this study, we aim at better constraining the boundary conditions of shatter cone formation in impact experiments and test a novel approach to qualitatively and quantitatively describe shatter cone geometries by white light interferometry. We recovered several ejected fragments from MEMIN cratering experiments that show slightly curved, striated surfaces and conical geometries with apices of 36°-52°. These fragments fulfilling the morphological criteria of shatter cones were found in experiments with 20-80 cm sized target cubes of sandstone, quartzite and limestone, but not in highly porous tuff. Targets were impacted by aluminum, steel, and iron meteorite projectiles at velocities of 4.6-7.8 km s-1. The projectile sizes ranged from 2.5-12 mm in diameter and produced experimental peak pressures of up to 86 GPa. In experiments with lower impact velocities shatter cones could not be found. A thorough morphometric analysis of the experimentally generated shatter cones was made with 3D white light interferometry scans at micrometer accuracy. SEM analysis of the surfaces of recovered fragments showed vesicular melt films alternating with smoothly polished surfaces. We hypothesize that the vesicular melt films predominantly form at strain releasing steps and suggest that shatter cones are probably mixed mode fractures.

  4. Evaluation of the Effect of the Volume Throughput and Maximum Flux of Low-Surface-Tension Fluids on Bacterial Penetration of 0.2 Micron-Rated Filters during Process-Specific Filter Validation Testing.

    PubMed

    Folmsbee, Martha

    2015-01-01

    Approximately 97% of filter validation tests result in the demonstration of absolute retention of the test bacteria, and thus sterile filter validation failure is rare. However, while Brevundimonas diminuta (B. diminuta) penetration of sterilizing-grade filters is rarely detected, the observation that some fluids (such as vaccines and liposomal fluids) may lead to an increased incidence of bacterial penetration of sterilizing-grade filters by B. diminuta has been reported. The goal of the following analysis was to identify important drivers of filter validation failure in these rare cases. The identification of these drivers will hopefully serve the purpose of assisting in the design of commercial sterile filtration processes with a low risk of filter validation failure for vaccine, liposomal, and related fluids. Filter validation data for low-surface-tension fluids was collected and evaluated with regard to the effect of bacterial load (CFU/cm(2)), bacterial load rate (CFU/min/cm(2)), volume throughput (mL/cm(2)), and maximum filter flux (mL/min/cm(2)) on bacterial penetration. The data set (∼1162 individual filtrations) included all instances of process-specific filter validation failures performed at Pall Corporation, including those using other filter media, but did not include all successful retentive filter validation bacterial challenges. It was neither practical nor necessary to include all filter validation successes worldwide (Pall Corporation) to achieve the goals of this analysis. The percentage of failed filtration events for the selected total master data set was 27% (310/1162). Because it is heavily weighted with penetration events, this percentage is considerably higher than the actual rate of failed filter validations, but, as such, facilitated a close examination of the conditions that lead to filter validation failure. In agreement with our previous reports, two of the significant drivers of bacterial penetration identified were the total

  5. FAA Fluorescent Penetrant Laboratory Inspections

    SciTech Connect

    WINDES,CONNOR L.; MOORE,DAVID G.

    2000-08-02

    The Federal Aviation Administration Airworthiness Assurance NDI Validation Center currently assesses the capability of various non-destructive inspection (NDI) methods used for analyzing aircraft components. The focus of one such exercise is to evaluate the sensitivity of fluorescent liquid penetrant inspection. A baseline procedure using the water-washable fluorescent penetrant method defines a foundation for comparing the brightness of low cycle fatigue cracks in titanium test panels. The analysis of deviations in the baseline procedure will determine an acceptable range of operation for the steps in the inspection process. The data also gives insight into the depth of each crack and which step(s) of the inspection process most affect penetrant sensitivities. A set of six low cycle fatigue cracks produced in 6.35-mm thick Ti-6Al-4V specimens was used to conduct the experiments to produce sensitivity data. The results will document the consistency of the crack readings and compare previous experiments to find the best parameters for water-washable penetrant.

  6. A Technique for Determining Relaxation Times by Free-Flight Tests of Low-Fineness-Ratio Cones; with Experimental Results for Air at Equilibrium Temperatures up to 3440 K

    NASA Technical Reports Server (NTRS)

    Stephenson, Jack D.

    1960-01-01

    This report describes a technique which combines theory and experiments for determining relaxation times in gases. The technique is based on the measurement of shapes of the bow shock waves of low-fineness-ratio cones fired from high-velocity guns. The theory presented in the report provides a means by which shadowgraph data showing the bow waves can be analyzed so as to furnish effective relaxation times. Relaxation times in air were obtained by this technique and the results have been compared with values estimated from shock tube measurements in pure oxygen and nitrogen. The tests were made at velocities ranging from 4600 to 12,000 feet per second corresponding to equilibrium temperatures from 35900 R (19900 K) to 6200 R (34400 K), under which conditions, at all but the highest temperatures, the effective relaxation times were determined primarily by the relaxation time for oxygen and nitrogen vibrations.

  7. Simulated meteoroid penetration of reusable surface insulation

    NASA Technical Reports Server (NTRS)

    Lehman, J. K.; Christensen, H. E.

    1973-01-01

    Meteoroid impact simulation test results on insulation tiles were used to determine penetration resistance of reusable surface insulation attached to simulated shuttle structures. The probability of no meteoroid damage to a typical shuttle orbiter was determined. Specimens were plasma jet tested to determine effects of various size meteoroid cavities on their thermal performance. None of the tiles failed catastrophically, but large, egg-shaped craters did result from meteoroid penetration. The metallic side of a specimen that was completely penetrated showed a petalled hole typical for thin gage shielded structures.

  8. 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

  9. Wide-Field Fundus Autofluorescence for Retinitis Pigmentosa and Cone/Cone-Rod Dystrophy.

    PubMed

    Oishi, Akio; Oishi, Maho; Ogino, Ken; Morooka, Satoshi; Yoshimura, Nagahisa

    2016-01-01

    Retinitis pigmentosa and cone/cone-rod dystrophy are inherited retinal diseases characterized by the progressive loss of rod and/or cone photoreceptors. To evaluate the status of rod/cone photoreceptors and visual function, visual acuity and visual field tests, electroretinogram, and optical coherence tomography are typically used. In addition to these examinations, fundus autofluorescence (FAF) has recently garnered attention. FAF visualizes the intrinsic fluorescent material in the retina, which is mainly lipofuscin contained within the retinal pigment epithelium. While conventional devices offer limited viewing angles in FAF, the recently developed Optos machine enables recording of wide-field FAF. With wide-field analysis, an association between abnormal FAF areas and visual function was demonstrated in retinitis pigmentosa and cone-rod dystrophy. In addition, the presence of "patchy" hypoautofluorescent areas was found to be correlated with symptom duration. Although physicians should be cautious when interpreting wide-field FAF results because the peripheral parts of the image are magnified significantly, this examination method provides previously unavailable information.

  10. 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.

  11. 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.

  12. Liquid penetration of barrier materials

    NASA Astrophysics Data System (ADS)

    Miller, Angela Maria

    1998-12-01

    Liquid penetration of porous materials is important for applications such as protective clothing, resin impregnation of fibers for composites, and filtration. A test apparatus for determining pressure at liquid breakthrough as a function of flow rate has been designed and constructed. Using this method, it was determined that liquid penetration of a material produces an interesting pressure curve where liquid breakthrough is followed by a peak in pressure and then a drop corresponding to equilibrium flow. This test method allows for comparison of materials in terms of barrier performance and also gives insight into the liquid saturation process. Three materials were tested with water as challenge liquids of varying viscosity and wettability. It was determined that pressure at liquid breakthrough was not dependent on the flow rate nor the viscosity of the challenge liquid but was dependent on the wettability of the challenge liquid. Also of interest was that more passages were opened through the material as flow rate was increased. A numerical model of liquid penetration of a barrier material was created based on invasion percolation. The model has been shown to be consistent with experimental results.

  13. 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.

  14. 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.

  15. 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

  16. 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

  17. Are cognitive outcome and recovery different in civilian penetrating versus non-penetrating brain injuries?

    PubMed

    Ylioja, Shelley; Hanks, Robin; Baird, Anne; Millis, Scott

    2010-10-01

    The present study sought to determine whether cognitive outcome and course of recovery in civilian penetrating brain injury due to gunshot can be distinguished from that of non-penetrating brain injury due to motor vehicle accident. Matched survivors of penetrating and non-penetrating brain injury were assessed with a brief neuropsychological test battery at inpatient rehabilitation, 1 year post-injury, and 2 years post-injury. The traumatic brain injury groups were found to have patterns of performance marked by reliably distinct differences in isolated areas, with different cognitive predictors of brain injury type present in early versus later recovery. The degree of recovery over the first 2 years appeared to be quite similar for penetrating and non-penetrating injuries.

  18. 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,…

  19. 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,…

  20. Reliability of cone counts using an adaptive optics retinal camera.

    PubMed

    Bidaut Garnier, Mélanie; Flores, Mathieu; Debellemanière, Guillaume; Puyraveau, Marc; Tumahai, Perle; Meillat, Mathieu; Schwartz, Claire; Montard, Michel; Delbosc, Bernard; Saleh, Maher

    2014-12-01

    To assess the reproducibility and repeatability of cone imaging in healthy human eyes, using the RTx-1 Adaptive Optics Retinal Camera and its proprietary cone-counting software. Single-centre, prospective study. Ten healthy adults. Macular cones were imaged. Intrasession repeatability was assessed by comparing 10 consecutive acquisitions obtained by the same operator from each subject. For the intersession study, each subject was imaged five consecutive days. Interoperator reproducibility was also evaluated by comparing the images obtained from 10 different subjects by two independent operators. Finally, intergrader agreement was evaluated by comparing the cone counts measured by two masked graders. Mean cone density (cells/mm(2) ), spacing between cells (μm) and percentage of cones with six neighbours calculated on Voronoi diagrams were measured. Correlation coefficients, intraclass correlation coefficients, and coefficients of variation were calculated. Correlation coefficient and intraclass correlation coefficient were respectively 0.81 and 0.96 between operators, and 0.97 and 0.98 between the two graders. The intrasession and intersession coefficients of variation were under 7%. The percentage of cells with six neighbours and the spacing between cones varied in the same proportion (coefficients of variation ranged from 1.66 to 10.05%). Overall, the test-retest variability of RTx-1 and its software was good in normal human eyes. Further studies in the normal clinical setting are mandatory. © 2014 Royal Australian and New Zealand College of Ophthalmologists.

  1. 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

  2. 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.

  3. 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

  4. Materials science. Dynamic mechanical behavior of multilayer graphene via supersonic projectile penetration.

    PubMed

    Lee, Jae-Hwang; Loya, Phillip E; Lou, Jun; Thomas, Edwin L

    2014-11-28

    Multilayer graphene is an exceptional anisotropic material due to its layered structure composed of two-dimensional carbon lattices. Although the intrinsic mechanical properties of graphene have been investigated at quasi-static conditions, its behavior under extreme dynamic conditions has not yet been studied. We report the high-strain-rate behavior of multilayer graphene over a range of thicknesses from 10 to 100 nanometers by using miniaturized ballistic tests. Tensile stretching of the membrane into a cone shape is followed by initiation of radial cracks that approximately follow crystallographic directions and extend outward well beyond the impact area. The specific penetration energy for multilayer graphene is ~10 times more than literature values for macroscopic steel sheets at 600 meters per second. Copyright © 2014, American Association for the Advancement of Science.

  5. 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.

  6. 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.

  7. Ignitability analysis using the cone calorimeter and lift apparatus

    Treesearch

    Mark A. Dietenberger

    1996-01-01

    The irradiance plotted as function of time to ignition for wood materials tested in the Cone Calorimeter (ASTM E1354) differs signiticantly from that tested in the Lateral Ignition and Flame spread Test (LIFT) apparatus (ASTM E1321). This difference in piloted ignitabilty is primarily due to the difference in forced convective cooling of the specimen tested in both...

  8. Cone Calorimeter Analysis of FRT Intumescent and Untreated Foam Core Particleboards

    Treesearch

    Mark A. Dietenberger; Ali Shalbafan; Johannes Welling; Charles Boardman

    2012-01-01

    The effectiveness of treatments of the surface layer of novel foam core particleboards were evaluated by means of Cone calorimeter tests. Foam core particleboards with variations of surface layer treatment, adhesives and surface layer thicknesses under similar processing conditions were used to produce the test specimen for the Cone calorimeter tests. Ignitability,...

  9. 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.

  10. Design and development of new collimator cones for fractionated stereotactic radiation therapy in Samsung Medical Center.

    PubMed

    Ahn, Y C; Ju, S G; Kim, D Y; Choi, D R; Huh, S J; Park, Y H; Lim, D H; Kim, M K

    1999-05-01

    In stereotactic radiotherapy using X-Knife system, the commercially supplied collimator cone system had a few mechanical limitations. The authors have developed new collimator cones to overcome these limitations and named them "SMC type" collimator cones. We made use of cadmium-free cerrobend alloy within the stainless steel cylinder housing. We made nine cones of relatively larger sizes (3.0 cm to 7.0 cm in diameter) and of shorter length with bigger clearance from the isocenter than the commercial cones. The cone housing and the collimator cones were designed to insert into the wedge mount of the gantry head to enable double-exposure linac-gram taking. The mechanical accuracy of pointing to the isocenter was tested by ball test and cone rotation test, and the dosimetric measurements were performed, all of which were with satisfactory results. A new innovative quality assurance procedure using linac-grams on the patients at the actual treatment setup was attempted after taking 10 sets of AP and lateral linac-grams and the overall mechanical isocenter accuracy was excellent (average error = 0.4 +/- 0.2 mm). We have developed the SMC type collimator cone system mainly for fractionated stereotactic radiation therapy use with our innovative ideas. The new cones' mechanical accuracy and physical properties were satisfactory for clinical use, and the verification of the isocenter accuracy on the actual treatment setup has become possible.

  11. Experimental Investigation of InSight HP3 Mole Interaction with Martian Regolith Simulant - Quasi-Static and Dynamic Penetration Testing

    NASA Astrophysics Data System (ADS)

    Marshall, Jason P.; Hudson, Troy L.; Andrade, José E.

    2017-05-01

    The InSight mission launches in 2018 to characterize several geophysical quantities on Mars, including the heat flow from the planetary interior. This quantity will be calculated by utilizing measurements of the thermal conductivity and the thermal gradient down to 5 meters below the Martian surface. One of the components of InSight is the Mole, which hammers into the Martian regolith to facilitate these thermal property measurements. In this paper, we experimentally investigated the effect of the Mole's penetrating action on regolith compaction and mechanical properties. Quasi-static and dynamic experiments were run with a 2D model of the 3D cylindrical mole. Force resistance data was captured with load cells. Deformation information was captured in images and analyzed using Digitial Image Correlation (DIC). Additionally, we used existing approximations of Martian regolith thermal conductivity to estimate the change in the surrounding granular material's thermal conductivity due to the Mole's penetration. We found that the Mole has the potential to cause a high degree of densification, especially if the initial granular material is relatively loose. The effect on the thermal conductivity from this densification was found to be relatively small in first-order calculations though more complete thermal models incorporating this densification should be a subject of further investigation. The results obtained provide an initial estimate of the Mole's impact on Martian regolith thermal properties.

  12. 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

  13. 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

  14. Exposing the dead cone effect with jet substructure techniques

    NASA Astrophysics Data System (ADS)

    Maltoni, Fabio; Selvaggi, Michele; Thaler, Jesse

    2016-09-01

    The dead cone is a well-known effect in gauge theories, where radiation from a charged particle of mass m and energy E is suppressed within an angular size of m /E . This effect is universal as it does not depend on the spin of the particle nor on the nature of the gauge interaction. It is challenging to directly measure the dead cone at colliders, however, since the region of suppressed radiation either is too small to be resolved or is filled by the decay products of the massive particle. In this paper, we propose to use jet substructure techniques to expose the dead cone effect in the strong-force radiation pattern around boosted top quarks at the Large Hadron Collider. Our study shows that with 300 /fb of 13-14 TeV collision data, ATLAS and CMS could obtain the first direct evidence of the dead cone effect and test its basic features.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Cone-like morphological, molecular, and electrophysiological features of the photoreceptors of the Nrl knockout mouse.

    PubMed

    Daniele, Lauren L; Lillo, Concepcion; Lyubarsky, Arkady L; Nikonov, Sergei S; Philp, Nancy; Mears, Alan J; Swaroop, Anand; Williams, David S; Pugh, Edward N

    2005-06-01

    To test the hypothesis that Nrl(-)(/)(-) photoreceptors are cones, by comparing them with WT rods and cones using morphological, molecular, histochemical, and electrophysiological criteria. The photoreceptor layer of fixed retinal tissue of 4- to 6-week-old mice was examined in plastic sections by electron microscopy, and by confocal microscopy in frozen sections immunolabeled for the mouse UV-cone pigment and colabeled with PNA. Quantitative immunoblot analysis was used to determine the levels of expression of key cone-specific proteins. Single- and paired-flash methods were used to extract the spectral sensitivity, kinetics, and amplification of the a-wave of the ERG. Outer segments of Nrl(-/-) photoreceptors ( approximately 7 mum) are shorter than those of wild-type (WT) rods ( approximately 25 mum) and cones ( approximately 15 mum); but, like WT cones, they have 25 or more basal discs open to the extracellular space, extracellular matrix sheaths stained by PNA, chromatin "clumping" in their nuclei, and mitochondria two times shorter than rods. Nrl(-/-) photoreceptors express the mouse UV cone pigment, cone transducin, and cone arrestin in amounts expected, given the relative size and density of cones in the two retinas. The ERG a-wave was used to assay the properties of the photocurrent response. The sensitivity of the Nrl(-/-) a-wave is at its maximum at 360 nm, with a secondary mode at 510 nm having approximately one-tenth the maximum sensitivity. These wavelengths are the lambda(max) of the two mouse cone pigments. The time to peak of the dim-flash photocurrent response was approximately 50 ms, more than two times faster than that of rods. Many morphological, molecular, and electrophysiological features of the Nrl(-/-) photoreceptors are cone-like, and strongly distinguish these cells from rods. This retina provides a model for the investigation of cone function and cone-specific genetic disease.

  1. 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

  2. Cone and Seed Maturation of Southern Pines

    Treesearch

    James P. Barnett

    1976-01-01

    If slightly reduced yields and viability are acceptable, loblolly and slash cone collections can begin 2 to 3 weeks before maturity if the cones are stored before processing. Longleaf(P. palestris Mill.) pine cones should be collected only when mature, as storage decreased germination of seeds from immature cones. Biochemical analyses to determine reducing sugar...

  3. 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

  4. 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.

  5. 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.

  6. Effect of Liquid Penetrant Sensitivity on Probability of Detection

    NASA Technical Reports Server (NTRS)

    Parker, Bradford H.

    2008-01-01

    The objective of the task is to investigate the effect of liquid penetrant sensitivity level on probability of crack detection (POD). NASA-STD-5009 currently requires the use of only sensitivity level 4 liquid penetrants. This requirement is based on the fact that the data generated in the NTIAC Nondestructive Evaluation (NDE) Capabilities Data Book was produced using only sensitivity level 4 penetrants. Many NDE contractors supporting NASA Centers routinely use sensitivity level 3 penetrants. Because of the new NASA-STD-5009 requirement, these contractors will have to either shift to sensitivity level 4 penetrants or perform formal POD demonstration tests to qualify their existing process.

  7. 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

  8. 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.

  9. 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

  10. A Cone Shaped Hill

    NASA Image and Video Library

    2015-10-14

    There are many hills and knobs on Mars that reveal aspects of the local geologic history. Typically, the hills in the relatively-smooth region surrounding this image are flat topped erosional remnants or mesas with irregular or even polyhedral margins. These landforms suggest wide spread erosion of the soft or weakly-cemented sedimentary layers. This hill stands out because of is circular inverted-cone shape and apparent dark streaks along its flanks visible in lower resolution images. Close inspection from HiRISE reveals that the fine soils sloping down from the peak are intersected with radiating lines of rock and eroding rubble. This formation is similar to lava intrusions that form in the core of a volcano. As lava is squeezed up into a central conduit, radiating fractures fill with lava forming rock units called dikes. As the lava cools inside the ground and in the fractures, it forms into a harder rock that is more resistant to erosion. Later, as the surrounding sediments and soils erode, the resistant volcanic rock remains standing to tell a story of what happened underground long ago. http://photojournal.jpl.nasa.gov/catalog/PIA20003

  11. 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.

  12. Soil penetrometers and penetrability

    USDA-ARS?s Scientific Manuscript database

    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...

  13. Large-Cone Nonnegative Matrix Factorization.

    PubMed

    Liu, Tongliang; Gong, Mingming; Tao, Dacheng

    2017-09-01

    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.

  14. 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.

  15. 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.

  16. 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.

  17. Hadronic wavefunctions in light-cone quantization

    SciTech Connect

    Hyer, Thomas

    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.

  18. 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.

  19. Cone and Rod Loss in Stargardt Disease Revealed by Adaptive Optics Scanning Light Ophthalmoscopy

    PubMed Central

    Song, Hongxin; Rossi, Ethan A.; Latchney, Lisa; Bessette, Angela; Stone, Edwin; Hunter, Jennifer J.; Williams, David R.; Chung, Mina

    2015-01-01

    Importance Stargardt disease (STGD1) is characterized by macular atrophy and flecks in the retinal pigment epithelium. The causative ABCA4 gene encodes a protein localizing to photoreceptor outer segments. The pathologic steps by which ABCA4 mutations lead to clinically detectable retinal pigment epithelium changes remain unclear. We investigated early STGD1 using adaptive optics scanning light ophthalmoscopy. Observations Adaptive optics scanning light ophthalmoscopy imaging of 2 brothers with early STGD1 and their unaffected parents was compared with conventional imaging. Cone and rod spacing were increased in both patients (P <.001) with a dark cone appearance. No foveal cones were detected in the older brother. In the younger brother, foveal cones were enlarged with low density (peak cone density, 48.3 × 103 cones/mm2). The ratio of cone to rod spacing was increased in both patients, with greater divergence from normal approaching the foveal center, indicating that cone loss predominates centrally and rod loss increases peripherally. Both parents had normal photoreceptor mosaics. Genetic testing revealed 3 disease-causing mutations. Conclusions and Relevance This study provides in vivo images of rods and cones in STGD1. Although the primary clinical features of STGD1 are retinal pigment epithelial lesions, adaptive optics scanning light ophthalmoscopy reveals increased cone and rod spacing in areas that appear normal in conventional images, suggesting that photoreceptor loss precedes clinically detectable retinal pigment epithelial disease in STGD1. PMID:26247787

  20. Imaging modal content of cone photoreceptors using adaptive optics optical coherence tomography

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

    It has been long established that photoreceptors capture light based on the principles of optical waveguiding. Yet after decades of experimental and theoretical investigations 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, we took advantage of adaptive-optics optical coherence tomography (AO-OCT, λc=785 nm) to noninvasively image in three dimensions the reflectance profiles generated in the inner and outer segments (IS, OS) of cones. Mode content was examined over a range of cone diameters by imaging cones from 0.6° to 10° retinal eccentricity (n = 1802). Fundamental to the method was extraction of reflections at the cone IS/OS junction and cone outer segment tip (COST). Modal content properties of size, circularity and orientation were quantified using second moment analysis. Analysis of the cone reflections indicates waveguide properties of cone IS and OS depend on segment diameter. 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, and show no orientation preference.

  1. 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

  2. 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

  3. 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.

  4. Subsurface investigation with ground penetrating radar

    USDA-ARS?s Scientific Manuscript database

    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...

  5. In-Situ Air Permeability Measurements Using the Cone Permeameter at the 200 East Area of the Hanford Site

    SciTech Connect

    TROYER, G.L.

    1999-03-31

    This report documents the field demonstration of the Cone Permeameter{trademark} (CPer) conducted at the Immobilization Low-Activity Waste (ILAW) site in the 200 East area of the Department of Energy's (DOE) Hanford facility. The demonstration was conducted using the Hanford Site Cone Penetration Platform (CPP) shown in Figure 1.1. The purpose of the technology demonstration was to (1) gather baseline data and evaluate the CPer's ability to measure air permeability in arid sands, silts and gravels; and (2) to determine the system's ability to replicate permeability profiles with multiple pushes in close proximity. The demonstration was jointly conducted by Applied Research Associates, Inc. (ARA) and Science and Engineering Associates (SEA). This report satisfies the requirements of ARA's contract No.2075 to Lockheed Martin Hanford Company. The report is organized into six major sections. This first section presents an introduction and outline to the report. Section 2 contains a discussion of the technologies used for the demonstration. Section 3 contains a brief description of the site where the demonstration was conducted. Section 4 describes the testing methodology and chronology. Section 5 presents the results obtained during the field test program. Comparisons between these results and existing site data are developed and discussed in Section 5. A conclusion and recommendation section is presented in Section 6 of the report.

  6. 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.

  7. 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).

  8. Centrifuge Modeling of Projectile Penetration in Granular Soils.

    NASA Astrophysics Data System (ADS)

    Taylor, Teresa Ann

    1988-12-01

    Investigations of the projectile penetration phenomenon in granular soils have been impeded by the difficulty in adequately quantifying and characterizing soil targets, and by the inability to directly scale results of 1-g penetration tests to full-scale conditions. The former is largely due to the failure to adequately prepare and quantify laboratory test samples, and the inherent limitations involved with testing and quantifying in situ soils. The latter is associated with an incomplete understanding of the soil parameters involved in the projectile penetration event. A series of laboratory tests on dry sands was conducted to assess the influence of confining pressure on projectile penetration depth, using a centrifuge to simulate full-scale stress levels in the soil targets. Projectiles were fired from a Thompson Contender^circler pistol at impact velocities of approximately 305 m/s into the rotating soil samples. Corresponding tests were conducted under 1-g conditions. The targets were prepared using a pluviation technique that resulted in uniform, reproducible samples of known density; this sample preparation technique contributed to the reproducibility of penetration test results that was observed in the test program. Significant differences in projectile penetration depths were obtained for different soils and for the same soils prepared at different densities. The penetration depths obtained in the test samples subjected to accelerated g-levels were compared to those obtained in corresponding 1-g tests. The test results indicate a gravity-dependence for the penetration event in granular soils. In addition, the magnitudes of penetration depths predicted by the centrifuge test results compare well to results from full-scale field tests. Thus, the centrifuge testing technique appears well-suited to further investigation of the penetration phenomenon in granular soils.

  9. Penetrating craniofacial arrow injury.

    PubMed

    Jain, Dk; Aggarwal, Gaurav; Lubana, Ps; Moses, Sonia

    2010-01-01

    Arrow injuries are an extinct form of injury in most parts of the developed world, but are still seen, albeit infrequently in developing countries. Reports of penetrating injuries of the craniofacial region secondary to projectiles are few and far between. The morbidity-free outcome of surgical removal, in case of penetrating arrow injuries, despite the delay in presentation and, moreover, in the emergency surgical practice, are the salient points to be remembered whilst managing such cases, for 'what the mind knows is what the eyes see and what the eyes see is what can be practiced'. We report the case of a patient who was attacked by a projectile fired from a crossbow. Immediate surgery under general anesthesia was required to remove the arrow, with utmost care to avoid any neurovascular compromise to the facial nerve, as well as minimize postoperative complications such as otitis media and subsequent meningitis.

  10. 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

  11. 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

  12. Shatter cones at sierra madera, Texas.

    PubMed

    Howard, K A; Offield, T W

    1968-10-11

    Shatter cones abound in the central uplift of Sierra Madera and they occur as far as 6.5 kilometers from the center. Apical angles average near 90 degrees. Whole cones and full cones represented by diversely oriented cone segments in any structural block show relatively uniform orientations of axes and a dominant direction of point. The cones predate faulting and folding in the central uplift, and, when beds are restored to horizontal, most cones point inward and upward, a pattern that supports the hypothesis of an impact origin.

  13. [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.

  14. 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.

  15. Analysis of thermal performance of penetrated multi-layer insulation

    NASA Technical Reports Server (NTRS)

    Foster, Winfred A., Jr.; Jenkins, Rhonald M.; Yoo, Chai H.; Barrett, William E.

    1988-01-01

    Results of research performed for the purpose of studying the sensitivity of multi-layer insulation blanket performance caused by penetrations through the blanket are presented. The work described in this paper presents the experimental data obtained from thermal vacuum tests of various penetration geometries similar to those present on the Hubble Space Telescope. The data obtained from these tests is presented in terms of electrical power required sensitivity factors referenced to a multi-layer blanket without a penetration. The results of these experiments indicate that a significant increase in electrical power is required to overcome the radiation heat losses in the vicinity of the penetrations.

  16. Penetration depth at green wavelengths in turbid waters

    NASA Technical Reports Server (NTRS)

    Whitlock, C. H.; Witte, W. G.; Usry, J. W.; Gurganus, E. A.

    1978-01-01

    A laboratory and field measurement program was conducted to determine apparent remote sensing penetration depths at a wavelength of 520 nm. Tests were made for various types of sediments under controlled conditions in a laboratory. Field tests were conducted in several different water bodies over a wide range of solar elevation angles. Laboratory results indicate that apparent penetration depth is significantly influenced by mineral content and/or size of suspended sediments. Field measurements show wide variation in apparent penetration depth, even when suspended solids concentration is nearly constant. Apparent penetration depth does not appear to be a strong function of solar elevation angle so long as the water mixture remains constant.

  17. Long-term retinal cone survival and delayed alteration of the cone mosaic in a transgenic mouse model of stargardt-like dystrophy (STGD3).

    PubMed

    Kuny, Sharee; Filion, Marc-André; Suh, Miyoung; Gaillard, Frédéric; Sauvé, Yves

    2014-01-21

    To examine the pattern of cone degeneration in the retina of a transgenic mouse model of Stargartd-like dystrophy (STGD3). Investigations were performed on ELOVL4/TG1-2 transgenic (TG) mice and wild-type (WT) littermates from 1 to 24 months of age. Phenotypes were assessed by fundus imaging, fatty acid analysis, and electroretinogram (ERG) recording. Cone degeneration pattern was determined on retina whole mounts using immunohistochemistry and Voronoi domain analyses. Consistent with low transgene expression, photoreceptors degenerate very slowly. At 1 month, anatomical structure and fatty acid composition of the TG retina is comparable with WT. Rod loss appears at 2 months, exhibiting a central to peripheral gradient, and fundus defects are observed at 3 months. In contrast, cone morphology, distribution and function are still normal at 12 months. Cone loss becomes apparent at 15 months when the outer nuclear layer is reduced to 3 to 4 photoreceptor rows. This process starts at the center of the retina and affects cone subtypes similarly. Very few cones remain at 24 months, after all rods have disappeared (18 months). Quantitative studies focusing on cones expressing M-opsin show a net increase in Voronoi domains and a significant decrease in regularity indexes only beyond 15 months. Photoreceptor degeneration in this STGD3 mouse model follows the time course of a slow rod-cone dystrophy. The cone mosaic is preserved for almost 1 year after the onset of rod loss. This long delay provides an opportunity to examine rod-cone interactions during retinal degeneration and to test therapeutic effectiveness at protracting cone dysfunction.

  18. 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.

  19. Quantum scattering on a cone revisited

    NASA Astrophysics Data System (ADS)

    Barroso, V. S.; Pitelli, J. P. M.

    2017-07-01

    We revisit the scattering of quantum test particles on the conical (2 +1 )-dimensional spacetime and find the scattering amplitude as a function of the boundary conditions imposed at the apex of the cone. We show that the boundary condition is responsible for a purely analytical term in the scattering amplitude, in addition to those coming from purely topological effects. Since it is possible to have nonequivalent physical evolutions for the wave packet (each one corresponding to a different boundary condition), it seems crucial to have an observable quantity specifying which evolution has been prescribed.

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. Flow pattern changes improve roller cone bit performance

    SciTech Connect

    Huffstutler, A.D.

    1996-05-06

    Improving the flow pattern through and around roller cone bits has increased penetration rate and footage while dropping the cost per foot drilled. These changes to the flow area around the bit help clean the bit and borehole more efficiently. By eliminating the protruding nozzle bosses, increasing nozzle bore size, narrowing the width of the bit arm segments, and providing a convex spherical dome, flow trajectories have been improved. These altered flow trajectories have eliminated hydraulic dead spots commonly found around current roller cone rock bit configurations. Nozzles are directed significantly more inward, toward the well bore bottom and away from the edge of the borehole. The flow impacts the bottom of the hole where it is needed most. Further performance enhancement features include an angled ramp on the shirt-tail portion of the arm to aid in lifting the cuttings upward, away from the cones and the bearing seals. Changing contours of the bit arms in the nozzle and bearing areas also improves cleaning and prevents cuttings from packing off in the bearing seal area.

  5. 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.

  6. 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.

  7. Two Shatter-Coned NWA Meteorites

    NASA Astrophysics Data System (ADS)

    McHone, J. F.; Shoemaker, C.; Killgore, M.; Killgore, K.

    2012-03-01

    Shatter cones are found in target rocks at more than 70 terrestrial impact sites and are regarded as reliable field criteria for meteoroid impact events. Shatter cones are now seen in chondritic meteorites and indicate early collision events.

  8. 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.

  9. 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

  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. Sub-microsecond vapor plume dynamics under different keyhole penetration regimes in deep penetration laser welding

    NASA Astrophysics Data System (ADS)

    Chen, Xin; Pang, Shengyong; Shao, Xinyu; Wang, Chunming; Zhang, Xiaosi; Jiang, Ping; Xiao, Jianzhong

    2017-05-01

    It is well-known that distinct vapor plume dynamics occur during deep penetration laser welding under different keyhole penetration states. However, there is little knowledge about the physical characteristics of vapor plumes (velocity, pressure, flow patterns, etc) located inside transient keyholes of varying penetration regimes in laser welding. This lack of knowledge is primarily because mesoscale vapor plumes are highly dynamic and generally invisible. Based on a well-tested three-dimensional multiphase laser welding model, we conducted a computational study on vapor plume dynamics inside transient keyholes during the fiber laser welding of 304 austenite stainless steel as a function of keyhole penetration regimes. We observed three keyhole regimes of penetration: full penetration, partial penetration and no penetration. We then physically analyzed the vapor plumes in these regimes. We determined that the vapor plume velocities and pressures in all three regimes were uneven and oscillated following the dynamic keyhole with a characteristic timescale in sub-microseconds. Only when the keyhole approached the full penetration regime did vapor plumes begin to violently eject from the bottom of the keyhole opening, whereas in the partial penetration regime, even when the bottom part of the keyhole was open, most of the vapor plume ejected from the upper keyhole opening. This latter observation was similar to that in the no penetration mode. We studied the physical mechanism of this behavior by analyzing the keyhole temperature and vapor plume velocity distributions. We determined that the upward ejection of the vapor plume from the upper keyhole opening was the result of an uneven micro-meter scale boiling phenomenon of the transient keyhole governed by Fresnel absorptions dependent on the local inclination angle of the keyhole wall. Similarly, we determined that the ejection of the vapor plume from the bottom of the keyhole opening resulted from pressure

  12. 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.

  13. Outcome measure for the treatment of cone photoreceptor diseases: orientation to a scene with cone-only contrast.

    PubMed

    Roman, Alejandro J; Cideciyan, Artur V; Matsui, Rodrigo; Sheplock, Rebecca; Schwartz, Sharon B; Jacobson, Samuel G

    2015-08-08

    Inherited retinal degenerations (IRDs) preferentially affecting cone photoreceptor function are being considered for treatment trials aiming to improve day vision. The purpose of the current work was to develop cone-specific visual orientation outcomes that can differentiate day vision improvement in the presence of retained night vision. A lighted wall (1.4 m wide, 2 m high) resembling a beaded curtain was formed with 900 individually addressable red, blue and green LED triplets placed in 15 vertical strips hanging 0.1 m apart. Under computer control, different combination of colors and intensities were used to produce the appearance of a door on the wall. Scotopically-matched trials were designed to be perceptible to the cone-, but not rod-, photoreceptor based visual systems. Unmatched control trials were interleaved at each luminance level to determine the existence of any vision available for orientation. Testing started with dark-adapted eyes and a scene luminance attenuated 8 log units from the maximum attainable, and continued with progressively increasing levels of luminance. Testing was performed with a three-alternative forced choice method in healthy subjects and patients with Leber congenital amaurosis (LCA) caused by mutations in GUCY2D, the gene that encodes retinal guanylate cyclase-1. Normal subjects could perform the orientation task using cone vision at 5 log attenuation and brighter luminance levels. Most GUCY2D-LCA patients failed to perform the orientation task with scotopically-matched test trials at any luminance level even though they were able to perform correctly with unmatched control trials. These results were consistent with a lack of cone system vision and use of the rod system under ambient conditions normally associated with cone system activity. Two GUCY2D-LCA patients demonstrated remnant cone vision but at a luminance level 2 log brighter than normal. The newly developed device can probe the existence or emergence of cone

  14. 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

  15. 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.

  16. Penetrating thoracic trauma.

    PubMed

    Bastos, Renata; Baisden, Clinton E; Harker, Lori; Calhoon, John H

    2008-01-01

    The initial approach to penetrating thoracic trauma is directed towards the pathophysiologic syndrome upon presentation. Most patients are successfully treated with drainage tubes. The unstable patient may necessitate thoracotomy at the emergency room to drain cardiac tamponade, provide cardiac massage and control bleeding. The guidelines for this procedure are reviewed. Need for further work-up of potential injuries to other mediastinal organs is frequently screened by computerized tomography. Surgery might still be needed, on a less emergent basis, in order to repair injuries to the trachea/esophagus, retained hemothorax, or to rule out diaphragmatic injury. Laparoscopic and thoracoscopic procedures may be used in specific situations.

  17. 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.

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

    PubMed

    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

    2016-07-01

    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. 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. 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. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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

  5. 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.

  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. Sand Penetration Experiments

    NASA Astrophysics Data System (ADS)

    Bless, Stephan; Berry, Don; Lawhorn, William

    2009-06-01

    In an experimental program, steel bullets and short cylinders, and tungsten alloy rods were shot into dry silica sand at 600 to 1100 m/s. The rods included finsets that were designed for aerodynamic stabilization. The fins also apparently provided trajectory stabilization within the sand as well. Time-of-arrival screens allowed measurement of velocity. Analysis of those data indicated that drag coefficients increased as projectiles slowed down. Comparison with previous data indicates there was a slight increase in drag coefficient of rods over expected values for unfinned rods; however, the net result was penetration normalized by length was as high as 40, depending on nose shape. It was found that when the velocity exceeded about 80 m/s (which is close to the speed of sound in sand) sand particles were broken down into their constituent grains, resulting in a decrease in size by about 1000. Normalized penetration is expected to scale as kinetic energy per unit area, and it was significantly higher for the rods than for the other projectiles. This is attributed to stabilization from interaction of the fins with the cavity wall.

  8. 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.

  9. 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.

  10. Ballistic variables and tissue devitalisation in penetrating injury--establishing relationship through meta-analysis of a number of pig tests.

    PubMed

    Jussila, Jorma; Kjellström, B Thomas; Leppäniemi, Ari

    2005-02-01

    Assessment of the injury potential is central to ascertaining that a law enforcement bullet does not cause unjustified and excessive injuries. There seems to prevail an understanding that tissue devitalisation correlates with kinetic energy dissipated into the tissue. Other views exist too. The purpose of the study was to find out whether such a correlation can be found and at what level of confidence. A number of reported tests done with live pigs with sufficient primary data have first been brought to the same temporally comparable level and then analysed. The tests comprise of 140 shots. To maintain consistency tests with other animals were excluded. The best correlation was obtained between excised muscle tissue and dissipated kinetic energy per millimetre of wound channel. An equation describing the relationship between dissipated energy E(d) and devitalised tissue m(deb) is presented as a regression function m(deb)=44.575xE(d)+10.319 with R2=0.293. An experimental method for estimating the energy used for bullet deformation of controlled deformation bullets is also presented. A method for using the regression function for obtaining tissue destruction figures for any point of wound channel formed in tissue simulant is presented. The figures are intended for meaningful comparison of the injury potential of various bullets and not for forecasting actual tissue injuries. The documentation of the ballistic properties in animal tests also seems somewhat lacking. Some changes in documenting firearms injuries are proposed in order to validate the methods and further enhance the fidelity of simulant testing.

  11. 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.

  12. 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.

  13. Wind-tunnel investigation of the 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 series of wind-tunnel tests have been 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 angles of attack, sideslip and coning rates. At the relatively low nondimensional coning rates employed, the lateral aerodynamic charactersitics generally show a linear variation with coning rate.

  14. 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.

  15. 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

  16. Annual and Geographic variations in cone production by longleaf pine

    Treesearch

    William D. Boyer

    1987-01-01

    Abstract.Cone production by longleaf pine (Pinus palustris Mill.) has been monitored on sample trees in shelterwood stands since 1966. Eleven locations, three each-in Alabama and Florida and one in Louisiana, Mississippi, Georgia, South Carolina, and North Carolina were included in the study. Each location had two test areas, with...

  17. 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.

  18. Mars penetrator umbilical. [to study geophysical properties of Mars

    NASA Technical Reports Server (NTRS)

    Barns, C. E.

    1979-01-01

    The device proposed to gather subsurface data on the planet Mars is a ballistic probe which penetrates the soil after a free fall through the Martian atmosphere. Highlights of the design, development, and testing of several features of the Mars Surface Penetration Probe are outlined.

  19. 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

  20. 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.

  1. 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

  2. Variation of cone photoreceptor packing density with retinal eccentricity and age.

    PubMed

    Song, Hongxin; Chui, Toco Yuen Ping; Zhong, Zhangyi; Elsner, Ann E; Burns, Stephen A

    2011-09-01

    To study the variation of cone photoreceptor packing density across the retina in healthy subjects of different ages. High-resolution adaptive optics scanning laser ophthalmoscope (AOSLO) systems were used to systematically image the retinas of two groups of subjects of different ages. Ten younger subjects (age range, 22-35 years) and 10 older subjects (age range, 50-65 years) were tested. Strips of cone photoreceptors, approximately 12° × 1.8° long were imaged for each of the four primary retinal meridians: superior, inferior, nasal, and temporal. Cone photoreceptors within the strips were counted, and cone photoreceptor packing density was calculated. Statistical analysis (three-way ANOVA) was used to calculate the interaction for cone photoreceptor packing density between age, meridian, and eccentricity. As expected, cone photoreceptor packing density was higher close to the fovea and decreased with increasing retinal eccentricity from 0.18 to 3.5 mm (∼0.6-12°). Older subjects had approximately 75% of the cone density at 0.18 mm (∼0.6°), and this difference decreased rapidly with eccentricity, with the two groups having similar cone photoreceptor packing densities beyond 0.5 mm retinal eccentricity on average. Cone packing density in the living human retina decreases as a function of age within the foveal center with the largest difference being found at our most central measurement site. At all ages, the retina showed meridional difference in cone densities, with cone photoreceptor packing density decreasing faster with increasing eccentricity in the vertical dimensions than in the horizontal dimensions.

  3. Variation of Cone Photoreceptor Packing Density with Retinal Eccentricity and Age

    PubMed Central

    Song, Hongxin; Chui, Toco Yuen Ping; Zhong, Zhangyi; Elsner, Ann E.

    2011-01-01

    Purpose. To study the variation of cone photoreceptor packing density across the retina in healthy subjects of different ages. Methods. High-resolution adaptive optics scanning laser ophthalmoscope (AOSLO) systems were used to systematically image the retinas of two groups of subjects of different ages. Ten younger subjects (age range, 22–35 years) and 10 older subjects (age range, 50–65 years) were tested. Strips of cone photoreceptors, approximately 12° × 1.8° long were imaged for each of the four primary retinal meridians: superior, inferior, nasal, and temporal. Cone photoreceptors within the strips were counted, and cone photoreceptor packing density was calculated. Statistical analysis (three-way ANOVA) was used to calculate the interaction for cone photoreceptor packing density between age, meridian, and eccentricity. Results. As expected, cone photoreceptor packing density was higher close to the fovea and decreased with increasing retinal eccentricity from 0.18 to 3.5 mm (∼0.6–12°). Older subjects had approximately 75% of the cone density at 0.18 mm (∼0.6°), and this difference decreased rapidly with eccentricity, with the two groups having similar cone photoreceptor packing densities beyond 0.5 mm retinal eccentricity on average. Conclusions. Cone packing density in the living human retina decreases as a function of age within the foveal center with the largest difference being found at our most central measurement site. At all ages, the retina showed meridional difference in cone densities, with cone photoreceptor packing density decreasing faster with increasing eccentricity in the vertical dimensions than in the horizontal dimensions. PMID:21724911

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. Effect of Liquid Penetrant Sensitivity on Probability of Detection

    NASA Technical Reports Server (NTRS)

    Parker, Bradford H.

    2011-01-01

    The objective of the task is to investigate the effect of liquid penetrant sensitivity level on probability of detection (POD) of cracks in various metals. NASA-STD-5009 currently requires the use of only sensitivity level 4 liquid penetrants for NASA Standard Level inspections. This requirement is based on the fact that the data used to establish the reliably detectable flaw sizes penetrant inspection was from studies performed in the 1970s using penetrant deemed to be equivalent only to modern day sensitivity level 4 penetrants. However, many NDE contractors supporting NASA Centers routinely use sensitivity level 3 penetrants. Because of the new NASA-STD-5009 requirement, these contractors will have to either shift to sensitivity level 4 penetrants or perform formal POD demonstration tests to qualify their existing process. We propose a study to compare the POD generated for two penetrant manufactures, Sherwin and Magnaflux, and for the two most common penetrant inspection methods, water washable and post emulsifiable, hydrophilic. NDE vendors local to GSFC will be employed. A total of six inspectors will inspect a set of crack panels with a broad range of fatigue crack sizes. Each inspector will perform eight inspections of the panel set using the combination of methods and sensitivity levels described above. At least one inspector will also perform multiple inspections using a fixed technique to investigate repeatability. The hit/miss data sets will be evaluated using both the NASA generated DOEPOD software and the MIL-STD-1823 software.

  11. Inside the cone of protection

    SciTech Connect

    Stahmann, J.R.

    1983-01-01

    Although lightning cones of protection and cones of attraction have been used for over 100 years, much confusion still remains as to their effectiveness, particularly as applied to personnel protection. At Kennedy Space Center, a 1:1 cone of protection with a straight side is standard for structure or equipment protection. However, at the launch pad, where a 400-foot lightning lightning rod on top of an insulating mast is used for pad lightning protection, the idea developed that personnel within a 400-foot radius of this mast would be safe from lightning and those outside it would not. Since it is obvious that a person 395 feet (120.4 m.) from the mast is only slightly safer than one at 405 feet (123.5 m.), an investigation was initiated to calculate the probabilities of a person being struck by lightning as he moves closer to the mast inside the cone of protection. Since the risk does not go to zero outside the structure, the risk level can then be estimated. To arrive at the expected strike frequency, it was necessary to measure the strike frequencies at KSC. Krider and others have found a mean area density of cloud-to-ground lightning at KSC of about 4.6 + or - 3.1 flashes per sq km per month in the summer. An overall frequency is estimated as about 20 flashes per sq km per year. With these data, the risk of exposure at various distances from the lightning mast can be calculated. Assuming continuous exposure during thunderstorms, this risk varies from about one strike per person in 1,400 years near the tower to one stroke per person in 300 years at about 400 foot (122 m.).

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. Light-cone quantization of quantum chromodynamics

    SciTech Connect

    Brodsky, S.J. ); Pauli, H.C. )

    1991-06-01

    We discuss the light-cone quantization of gauge theories from two perspectives: as a calculational tool for representing hadrons as QCD bound-states of relativistic quarks and gluons, and also as a novel method for simulating quantum field theory on a computer. The light-cone Fock state expansion of wavefunctions at fixed light cone time provides a precise definition of the parton model and a general calculus for hadronic matrix elements. We present several new applications of light-cone Fock methods, including calculations of exclusive weak decays of heavy hadrons, and intrinsic heavy-quark contributions to structure functions. A general nonperturbative method for numerically solving quantum field theories, discretized light-cone quantization,'' is outlined and applied to several gauge theories, including QCD in one space and one time dimension, and quantum electrodynamics in physical space-time at large coupling strength. The DLCQ method is invariant under the large class of light-cone Lorentz transformations, and it can be formulated such at ultraviolet regularization is independent of the momentum space discretization. Both the bound-state spectrum and the corresponding relativistic light-cone wavefunctions can be obtained by matrix diagonalization and related techniques. We also discuss the construction of the light-cone Fock basis, the structure of the light-cone vacuum, and outline the renormalization techniques required for solving gauge theories within the light-cone Hamiltonian formalism.

  17. Effects of Rock High Pressure Strength on Penetration

    NASA Astrophysics Data System (ADS)

    Huang, Hongfa

    2011-06-01

    Perforating of oil/gas well creates communication tunnel between reservoir and wellbore. Shaped charges are widely used as perforators in oilfield industry. The liners of the charges are mostly made of powder metal to prevent solid slug clogging the entrance hole of well casing or locking the hole in perforating gun. High speed jet from the shaped charge pierces through perforating gun, well fluid, well casing, and then penetrates into reservoir formation. Prediction of jet penetration in reservoir rock is critical in modeling of well production. An analytical penetration model developed for solid rod by Tate and Alekseevskii is applied. However, strength of formation rock at high pressure needs to be measured. Lateral stress gauge measurements in plate impact tests are conducted. Piezoelectric pressure gauges are imbedded in samples to measure the longitudinal and transverse stress. The two stresses provide Hugoniot and material compressive strength. Indiana limestone, a typical rock in perforation testing, is selected as target sample material in the plate impact tests. Since target strength effect on penetration is more significant in late stage of penetration when the strength of material becomes significant compared to the impact pressure, all the impact tests are focused on lower impact pressure up to 9 GPa. The measurements show that the strength increases with impact pressure. The results are applied in the penetration calculations. The final penetration matches testing data very well.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Psychophysical measurement of rod and cone thresholds in stargardt disease with full-field stimuli.

    PubMed

    Collison, Frederick T; Fishman, Gerald A; McAnany, J Jason; Zernant, Jana; Allikmets, Rando

    2014-09-01

    To investigate psychophysical thresholds in Stargardt disease with the full-field stimulus test (FST). Visual acuity, spectral domain optical coherence tomography, full-field electroretinogram, and FST measurements were made in 1 eye of 24 patients with Stargardt disease. Dark-adapted rod FST thresholds were measured with short-wavelength stimuli, and cone FST thresholds were obtained from the cone plateau phase of dark adaptation using long-wavelength stimuli. Correlation coefficients were calculated for FST thresholds versus macular thickness, visual acuity, and electroretinogram amplitudes. The Stargardt disease patients' FST cone thresholds correlated significantly with visual acuity, macular thickness, and electroretinogram cone response amplitudes (all P < 0.01). The patients' FST rod thresholds correlated with electroretinogram rod response amplitudes (P < 0.01) but not macular thickness (P = 0.05). All patients with Stargardt disease with flecks confined to the macula, and most of the patients with flecks extending outside of the macula had normal FST thresholds. All patients with extramacular atrophic changes had elevated FST cone thresholds and most had elevated FST rod thresholds. Full-field stimulus test rod and cone threshold elevation in patients with Stargardt disease correlated well with measures of structure and function, as well as ophthalmoscopic retinal appearance. The Full-field stimulus test appears to be a useful tool for assessing rod and cone function in Stargardt disease.

  5. Analysis of state-of-the-art single-thruster attitude control techniques for spinning penetrator

    NASA Astrophysics Data System (ADS)

    Raus, Robin; Gao, Yang; Wu, Yunhua; Watt, Mark

    2012-07-01

    The attitude dynamics and manoeuvre survey in this paper is performed for a mission scenario involving a penetrator-type spacecraft: an axisymmetric prolate spacecraft spinning around its minor axis of inertia performing a 90° spin axis reorientation manoeuvre. In contrast to most existing spacecraft only one attitude control thruster is available, providing a control torque perpendicular to the spin axis. Having only one attitude thruster on a spinning spacecraft could be preferred for spacecraft simplicity (lower mass, lower power consumption etc.), or it could be imposed in the context of redundancy/contingency operations. This constraint does yield restrictions on the thruster timings, depending on the ratio of minor to major moments of inertia among other parameters. The Japanese Lunar-A penetrator spacecraft proposal is a good example of such a single-thruster spin-stabilised prolate spacecraft. The attitude dynamics of a spinning rigid body are first investigated analytically, then expanded for the specific case of a prolate and axisymmetric rigid body and finally a cursory exploration of non-rigid body dynamics is made. Next two well-known techniques for manoeuvring a spin-stabilised spacecraft, the Half-cone/Multiple Half-cone and the Rhumb line slew, are compared with two new techniques, the Sector-Arc Slew developed by Astrium Satellites and the Dual-cone developed at Surrey Space Centre. Each technique is introduced and characterised by means of simulation results and illustrations based on the penetrator mission scenario and a brief robustness analysis is performed against errors in moments of inertia and spin rate. Also, the relative benefits of each slew algorithm are discussed in terms of slew accuracy, energy (propellant) efficiency and time efficiency. For example, a sequence of half-cone manoeuvres (a Multi-half-cone manoeuvre) tends to be more energy-efficient than one half-cone for the same final slew angle, but more time-consuming. As another

  6. 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.

  7. 40 CFR 1065.365 - Nonmethane cutter penetration fractions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... do not limit NMC penetration fractions to a certain range. However, we recommend that you optimize a... procedure on the highest range used for emission testing. (2) Start, operate, and optimize the nonmethane...

  8. Development of a Rover Deployed Ground Penetrating Radar

    NASA Technical Reports Server (NTRS)

    Grant, J. A.; Schutz, A. E.; Campbell, B. A.

    2000-01-01

    Development of a rover deployable Ground Penetrating Radar (GPR) involves: the nearly finished design and testing of a transducer array with high frequency (bistatic) and low frequency (monostatic) components; and design and development of a complete impulse GPR system.

  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. Analytical Chemistry Laboratory (ACL) procedure compendium. Volume 6, Physical testing

    SciTech Connect

    Not Available

    1993-08-01

    This volume contains the interim change notice for physical testing. Covered are: properties of solutions, slurries, and sludges; rheological measurement with cone/plate viscometer; % solids determination; particle size distribution by laser scanning; penetration resistance of radioactive waste; operation of differential scanning calorimeter, thermogravimetric analyzer, and high temperature DTA and DSC; sodium rod for sodium bonded fuel; filling SP-100 fuel capsules; sodium filling of BEATRIX-II type capsules; removal of alkali metals with ammonia; specific gravity of highly radioactive solutions; bulk density of radioactive granular solids; purification of Li by hot gettering/filtration; and Li filling of MOTA capsules.

  11. 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…

  12. 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…

  13. Light-cones, almost light-cones and almost-complex light-cones

    NASA Astrophysics Data System (ADS)

    Newman, Ezra T.

    2017-08-01

    We point out (and then apply to a general situation) an unusual relationship among a variety of null geodesic congruences; (a) the generators of ordinary light-cones and (b) certain (related) shear-free but twisting congruences in Minkowski space-time as well as (c) asymptotically shear-free null geodesic congruences that exist in the neighborhood of Penrose's I^{ +} in Einstein or Einstein-Maxwell asymptotically flat-space-times. We refer to these geodesic congruences respectively as: Lignt-Cones (LCs), as "Almost-Complex"-Light-Cones (ACLCs), [though they are real they resemble complex light-cones in complex Minkowski space] and finally to a family of congruences in asymptotically flat-spaces as ` Almost Light-Cones' (ALC). The two essential points of resemblance among the three families are: (1) they are all either shear-free or asymptotically shear-free and (2) in each family the individual members of the family can be labeled by the points in a real or complex four-dimensional manifold. As an example, the Minkowski space LCs are labeled by the (real) coordinate value of their apex. In the case of (ACLCs) (complex coordinate values), the congruences will have non-vanishing twist whose magnitude is determined by the imaginary part of the complex coordinate values. In studies of gravitational radiation, Bondi-type of null surfaces and their associated Bondi coordinates have been almost exclusively used for calculations. It turns out that some surprising relations arise if, instead of the Bondi coordinates, one uses ALCs and their associated coordinate systems in the analysis of the Einstein-Maxwell equations in the neighborhood of I+. More explicitly and surprisingly, the asymptotic Bianchi Identities (arising directly from the Einstein equations), expressed in the coordinates of the ALCs, turn directly into many of the standard definitions and equations and relations of classical mechanics coupled with Maxwell's equations. These results extend and generalize the

  14. 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.

  15. 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.

  16. Physical properties of new collimator cone system for stereotactic radiation therapy developed in samsung medical center.

    PubMed

    Kim, D Y; Ahn, Y C; Oh, D G; Choi, D R; Ju, S G; Yeo, I H; Huh, S J

    2000-09-01

    A new collimator cone system has been developed at the Samsung Medical Center that overcomes some of the limitations of present commercially supplied collimator cones. The physical properties of the newly developed cone system are described in this report. The new cones have relatively larger aperture sizes (3.0-7.0 cm in diameter) and are 16 cm in length. Each new cone is fabricated with cerrobend alloy melted and poured into a stainless steel housing that is permanently fixed to a mounting plate. The mounting plate of the new cone is designed to insert into the wedge mount slot of the gantry head. The mechanical accuracy of the central axis of the cone pointing to the isocenter was tested using film, a steel ball positioned at the isocenter by the mechanical isocenter device. For the evaluation of beam flatness and penumbra, off-axis ratios at 5 cm depth were measured by film dosimetry using polystyrene phantom. The average error of the mechanical isocenter was 0.27 mm (+/- 0.16 mm). The beam flatness was excellent in the central region of the beam, and the average penumbra width was 3.35 mm (+/- 0.25 mm). The new cone design has more clearance between the patient's head and the gantry, and can more easily be removed from the gantry head because it slides in and out of the wedge slot. This facilitates changing cone sizes during one treatment session, and makes the process of double exposure port films easier. A new collimator cone system for stereotactic radiation therapy has been developed. The mechanical accuracy and physical properties are satisfactory for clinical use, and the new design permits a wider range of clinical applications for stereotactic radiation therapy.

  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. Projectile penetration into ballistic gelatin.

    PubMed

    Swain, M V; Kieser, D C; Shah, S; Kieser, J A

    2014-01-01

    Ballistic gelatin is frequently used as a model for soft biological tissues that experience projectile impact. In this paper we investigate the response of a number of gelatin materials to the penetration of spherical steel projectiles (7 to 11mm diameter) with a range of lower impacting velocities (<120m/s). The results of sphere penetration depth versus projectile velocity are found to be linear for all systems above a certain threshold velocity required for initiating penetration. The data for a specific material impacted with different diameter spheres were able to be condensed to a single curve when the penetration depth was normalised by the projectile diameter. When the results are compared with a number of predictive relationships available in the literature, it is found that over the range of projectiles and compositions used, the results fit a simple relationship that takes into account the projectile diameter, the threshold velocity for penetration into the gelatin and a value of the shear modulus of the gelatin estimated from the threshold velocity for penetration. The normalised depth is found to fit the elastic Froude number when this is modified to allow for a threshold impact velocity. The normalised penetration data are found to best fit this modified elastic Froude number with a slope of 1/2 instead of 1/3 as suggested by Akers and Belmonte (2006). Possible explanations for this difference are discussed. © 2013 Published by Elsevier Ltd.

  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. Impact of oral melatonin on the electroretinogram cone response

    PubMed Central

    2009-01-01

    Background In the eye, melatonin plays a role in promoting light sensitivity at night and modulating many aspects of circadian retinal physiology. It is also an inhibitor of retinal dopamine, which is a promoter of day vision through the cone system. Consequently, it is possible that oral melatonin (an inhibitor of retinal dopamine) taken to alleviate circadian disorders may affect cone functioning. Our aim was to assess the impact of melatonin on the cone response of the human retina using electroretinography (ERG). Methods Twelve healthy participants aged between 18 to 52 years old were submitted to a placebo-controlled, double-blind, crossover, and counterbalanced-order design. The subjects were tested on 2 sessions beginning first with a baseline ERG, followed by the administration of the placebo or melatonin condition and then, 30 min later, a second ERG to test the effect. Results Following oral melatonin administration, a significant decrease of about 8% of the cone maximal response was observed (mean 6.9 μV ± SEM 2.0; P = 0.0065) along with a prolonged b-wave implicit time of 0.4 ms ± 0.1, 50 minutes after ingestion. Conclusion Oral melatonin appears to reach the eye through the circulation. When it is administered at a time of day when it is not usually present, melatonin appears to reduce input to retinal cones. We believe that the impact of melatonin on retinal function should be taken into consideration when used without supervision in chronic self-medication for sleep or circadian disorder treatment. PMID:19922677

  1. Impact of oral melatonin on the electroretinogram cone response.

    PubMed

    Gagné, Anne-Marie; Danilenko, Konstantin V; Rosolen, Serge G; Hébert, Marc

    2009-11-19

    In the eye, melatonin plays a role in promoting light sensitivity at night and modulating many aspects of circadian retinal physiology. It is also an inhibitor of retinal dopamine, which is a promoter of day vision through the cone system. Consequently, it is possible that oral melatonin (an inhibitor of retinal dopamine) taken to alleviate circadian disorders may affect cone functioning. Our aim was to assess the impact of melatonin on the cone response of the human retina using electroretinography (ERG). Twelve healthy participants aged between 18 to 52 years old were submitted to a placebo-controlled, double-blind, crossover, and counterbalanced-order design. The subjects were tested on 2 sessions beginning first with a baseline ERG, followed by the administration of the placebo or melatonin condition and then, 30 min later, a second ERG to test the effect. Following oral melatonin administration, a significant decrease of about 8% of the cone maximal response was observed (mean 6.9 muV +/- SEM 2.0; P = 0.0065) along with a prolonged b-wave implicit time of 0.4 ms +/- 0.1, 50 minutes after ingestion. Oral melatonin appears to reach the eye through the circulation. When it is administered at a time of day when it is not usually present, melatonin appears to reduce input to retinal cones. We believe that the impact of melatonin on retinal function should be taken into consideration when used without supervision in chronic self-medication for sleep or circadian disorder treatment.

  2. Caval penetration by retrievable inferior vena cava filters: a retrospective comparison of Option and Günther Tulip filters.

    PubMed

    Olorunsola, Olufoladare G; Kohi, Maureen P; Fidelman, Nicholas; Westphalen, Antonio C; Kolli, Pallav K; Taylor, Andrew G; Gordon, Roy L; LaBerge, Jeanne M; Kerlan, Robert K

    2013-04-01

    To compare the frequency of vena caval penetration by the struts of the Option and Günther Tulip cone filters on postplacement computed tomography (CT) imaging. All patients who had an Option or Günther Tulip inferior vena cava (IVC) filter placed between January 2010 and May 2012 were identified retrospectively from medical records. Of the 208 IVC filters placed, the positions of 58 devices (21 Option filters, 37 Günther Tulip filters [GTFs]) were documented on follow-up CT examinations obtained for reasons unrelated to filter placement. In cases when multiple CT studies were obtained after placement, each study was reviewed, for a total of 80 examinations. Images were assessed for evidence of caval wall penetration by filter components, noting the number of penetrating struts and any effect on pericaval tissues. Penetration of at least one strut was observed in 17% of all filters imaged by CT between 1 and 447 days following placement. Although there was no significant difference in the overall prevalence of penetration when comparing the Option filter and GTF (Option, 10%; GTF, 22%), only GTFs showed time-dependent penetration, with penetration becoming more likely after prolonged indwelling times. No patient had damage to pericaval tissues or documented symptoms attributed to penetration. Although the Günther Tulip and Option filters exhibit caval penetration at CT imaging, only the GTF exhibits progressive penetration over time. Copyright © 2013 SIR. Published by Elsevier Inc. All rights reserved.

  3. 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

  4. S-cones in thin shells under indentation

    NASA Astrophysics Data System (ADS)

    Nasto, Alice; Ajdari, Amin; Lazarus, Arnaud; Vaziri, Ashkan; Reis, Pedro

    2012-02-01

    We perform a hybrid experimental and numerical investigation of the localization of deformation in indented thin spherical elastic shells. Past the initial linear response, an inverted cap develops as a Pogorelov circular ridge. For further indentation, this ridge looses axis-symmetry and sharp points of localized curvature form. We refer to these localized objects as s-cones (for shell-cones), in contrast with their developable cousins in plates (d-cones). We quantify the effect of systematically varying the indenter's radius of curvature (from point to plate load) on the formation and evolution of s-cones. In our precision desktop-scale experiments we use rapid prototyped elastomeric shells and rigid indenters of various shape. The mechanical response is measured through load-displacement compression tests and the deformation process is further characterized through digital imaging. In parallel, the experimental results are contrasted against nonlinear Finite Element simulations. Merging these two complementary approaches allows us to gain further physical insight towards rationalizing this geometrically nonlinear process.

  5. Lipoprotein Uptake by Neuronal Growth Cones in Vitro

    NASA Astrophysics Data System (ADS)

    Ignatius, Michael J.; Shooter, Eric M.; Pitas, Robert E.; Mahley, Robert W.

    1987-05-01

    Macrophages that rapidly enter injured peripheral nerve synthesize and secrete large quantities of apolipoprotein E. This protein may be involved in the redistribution of lipid, including cholesterol released during degeneration, to the regenerating axons. To test this postulate, apolipoprotein E-associated lipid particles released from segments of injured rat sciatic nerve and apolipoprotein E-containing lipoproteins from plasma were used to determine whether sprouting neurites, specifically their growth cones, possessed lipoprotein receptors. Pheochromocytoma (PC12) cells, which can be stimulated to produce neurites in vitro, were used as a model system. Apolipoprotein E-containing lipid particles and lipoproteins, which had been labeled with fluorescent dye, were internalized by the neurites and their growth cones; the unmetabolized dye appeared to be localized to the lysosomes. The rapid rate of accumulation in the growth cones precludes the possibility of orthograde transport of the fluorescent particles from the PC12 cell bodies. Thus, receptor-mediated lipoprotein uptake is performed by the apolipoprotein B,E(LDL) (low density lipoprotein) receptors, and in the regenerating peripheral nerve apolipoprotein E may deliver lipids to the neurites and their growth cones for membrane biosynthesis.

  6. Ionic emission from Taylor cones

    NASA Astrophysics Data System (ADS)

    Castro Reina, Sergio

    Electrified Taylor cones have been seen as an efficient way to generate thrust for space propulsion. Especially the pure ionic regime (PIR) combines a very high specific impulse (thrust per unit mass) and efficiency, which is very important to reduce fuel transportation costs. The PIR has been primarily based on electrosprays of liquid metals [Swatik and Hendricks 1968, Swatik 1969]. However, emissions dominated by or containing exclusively ions have also been observed from nonmetallic purely ionic substances, initially sulfuric acid [Perel et al. 1969], and more recently room temperature molten salts referred to as ionic liquids (ILs) [Romero-Sanz et al. 2003]. The recent use of the liquid metal ion source (LMIS) with ILs, becoming this "new" source to be known as ionic liquid ion source (ILIS) [Lozano and Martinez-Sanchez 2005], has shown important differences on the emission from Taylor cones with the traditional hollow capillary. This new source seems to be more flexible than the capillary [Paulo, Sergio, carlos], although its low emission level (low thrust) is an important drawback from the space propulsion point of view. Throughout the thesis I have studied some aspects of the ionic emission from ionic liquid Taylor cones and the influence of the properties of the liquids and the characteristic of source on the emission. I have unraveled the reason why ILIS emits such low currents (˜200 nA) and found a way to solve this problem increasing the current up to capillary levels (˜1000 nA) [Castro and Fernandez de la Mora 2009]. I have also tried to reduce ion evaporation while reducing the emitted droplet size in order to increase the thrust generated while keeping the efficiency relatively high and I have measured the energy of evaporation of several cations composing ionic liquids, mandatory step to understand ionic evaporation.

  7. 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

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. Skin Penetration Enhancement by Natural Oils for Dihydroquercetin Delivery.

    PubMed

    Čižinauskas, Vytis; Elie, Nicolas; Brunelle, Alain; Briedis, Vitalis

    2017-09-12

    Natural oils are commonly used in topical pharmaceutical formulations as emulsifiers, stabilizers or solubility enhancers. They are presented as safe and inert components, mainly used for formulation purposes. It is confirmed that natural oils can affect the skin penetration of various substances. Fatty acids are mainly responsible for this effect. Current understanding lacks reliable scientific data on penetration of natural oils into the skin and their skin penetration enhancement potential. In the current study, fatty acid content analysis was used to determine the principal fatty acids in soybean, olive, avocado, sea-buckthorn pulp, raspberry seed and coconut oils. Time of flight secondary ion mass spectrometry bioimaging was used to determine the distribution of these fatty acids in human skin ex vivo after application of the oils. Skin penetration enhancement ratios were determined for a perspective antioxidant compound dihydroquercetin. The results demonstrated skin penetration of fatty acids from all oils tested. Only soybean and olive oils significantly increased the skin distribution of dihydroquercetin and can be used as skin penetration enhancers. However, no correlation can be determined between the fatty acids' composition and skin penetration enhancement using currently available methodological approaches. This indicates that potential chemical penetration enhancement should be evaluated during formulation of topically applied products containing natural oils.

  14. 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.

  15. THE KINETICS OF PENETRATION

    PubMed Central

    Osterhout, W. J. V.; Kamerling, S. E.

    1934-01-01

    A model is described which throws light on the mechanism of accumulation. In the model used an external aqueous phase A is separated by a non-aqueous phase B (representing the protoplasm) from the artificial sap in C. A contains KOH and C contains HCl: they tend to mix by passing through the non-aqueous layer but much more KOH moves so that most of the KCl is formed in C, where the concentration of potassium becomes much greater than in A. This accumulation is only temporary for as the system approaches equilibrium the composition of A approaches identity with that of C, since all the substances present can pass through the non-aqueous layer. Such an approach to equilibrium may be compared to the death of the cell as the result of which accumulation disappears. During the earlier stages of the experiment potassium tends to go in as KOH and at the same time to go out as KCl. These opposing tendencies do not balance until the concentration of potassium inside becomes much greater than outside (hence potassium accumulates). The reason is that KCl, although its driving force be great, moves very slowly in B because its partition coefficient is low and in consequence its concentration gradient in B is small. This illustrates the importance of partition coefficients for penetration in models and in living cells. It also indicates that accumulation depends on the fact that permeability is greater for the ingoing compound of the accumulating substance than for the outgoing compound. Other things being equal, accumulation is increased by maintaining a low pH in C. Hence we may infer that anything which checks the production of acid in the living cell may be expected to check accumulation and growth. This model recalls the situation in Valonia and in most living cells where potassium accumulates as KCl, perhaps because it enters as KOH and forms KA in the sap (where A is an organic anion). In some plants potassium accumulates as KA but when HCl exists in the external

  16. 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.

  17. Phenotypic characteristics including in vivo cone photoreceptor mosaic in KCNV2-related "cone dystrophy with supernormal rod electroretinogram".

    PubMed

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

    2013-01-30

    To report phenotypic characteristics including macular cone photoreceptor morphology in KCNV2-related "cone dystrophy with supernormal rod electroretinogram" (CDSR). 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 autofluorescence (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/m(2)). Macular cone photoreceptor morphology was assessed from 2° by 2° zonal images obtained using adaptive optics scanning laser ophthalmoscopy (AOSLO) in six cases. 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. 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.

  18. 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

  19. Patterning the cone mosaic array in zebrafish retina requires specification of ultraviolet-sensitive cones.

    PubMed

    Raymond, Pamela A; Colvin, Steven M; Jabeen, Zahera; Nagashima, Mikiko; Barthel, Linda K; Hadidjojo, Jeremy; Popova, Lilia; Pejaver, Vivek R; Lubensky, David K

    2014-01-01

    Cone photoreceptors in teleost fish are organized in precise, crystalline arrays in the epithelial plane of the retina. In zebrafish, four distinct morphological/spectral cone types occupy specific, invariant positions within a regular lattice. The cone lattice is aligned orthogonal and parallel to circumference of the retinal hemisphere: it emerges as cones generated in a germinal zone at the retinal periphery are incorporated as single-cell columns into the cone lattice. Genetic disruption of the transcription factor Tbx2b eliminates most of the cone subtype maximally sensitive to ultraviolet (UV) wavelengths and also perturbs the long-range organization of the cone lattice. In the tbx2b mutant, the other three cone types (red, green, and blue cones) are specified in the correct proportion, differentiate normally, and acquire normal, planar polarized adhesive interactions mediated by Crumbs 2a and Crumbs 2b. Quantitative image analysis of cell adjacency revealed that the cones in the tbx2b mutant primarily have two nearest neighbors and align in single-cell-wide column fragments that are separated by rod photoreceptors. Some UV cones differentiate at the dorsal retinal margin in the tbx2b mutant, although they are severely dysmorphic and are eventually eliminated. Incorporating loss of UV cones during formation of cone columns at the margin into our previously published mathematical model of zebrafish cone mosaic formation (which uses bidirectional interactions between planar cell polarity proteins and anisotropic mechanical stresses in the plane of the retinal epithelium to generate regular columns of cones parallel to the margin) reproduces many features of the pattern disruptions seen in the tbx2b mutant.

  20. Patterning the Cone Mosaic Array in Zebrafish Retina Requires Specification of Ultraviolet-Sensitive Cones

    PubMed Central

    Raymond, Pamela A.; Colvin, Steven M.; Jabeen, Zahera; Nagashima, Mikiko; Barthel, Linda K.; Hadidjojo, Jeremy; Popova, Lilia; Pejaver, Vivek R.; Lubensky, David K.

    2014-01-01

    Cone photoreceptors in teleost fish are organized in precise, crystalline arrays in the epithelial plane of the retina. In zebrafish, four distinct morphological/spectral cone types occupy specific, invariant positions within a regular lattice. The cone lattice is aligned orthogonal and parallel to circumference of the retinal hemisphere: it emerges as cones generated in a germinal zone at the retinal periphery are incorporated as single-cell columns into the cone lattice. Genetic disruption of the transcription factor Tbx2b eliminates most of the cone subtype maximally sensitive to ultraviolet (UV) wavelengths and also perturbs the long-range organization of the cone lattice. In the tbx2b mutant, the other three cone types (red, green, and blue cones) are specified in the correct proportion, differentiate normally, and acquire normal, planar polarized adhesive interactions mediated by Crumbs 2a and Crumbs 2b. Quantitative image analysis of cell adjacency revealed that the cones in the tbx2b mutant primarily have two nearest neighbors and align in single-cell-wide column fragments that are separated by rod photoreceptors. Some UV cones differentiate at the dorsal retinal margin in the tbx2b mutant, although they are severely dysmorphic and are eventually eliminated. Incorporating loss of UV cones during formation of cone columns at the margin into our previously published mathematical model of zebrafish cone mosaic formation (which uses bidirectional interactions between planar cell polarity proteins and anisotropic mechanical stresses in the plane of the retinal epithelium to generate regular columns of cones parallel to the margin) reproduces many features of the pattern disruptions seen in the tbx2b mutant. PMID:24465536

  1. Cone Storage and Seed Quality in Longleaf Pine

    Treesearch

    F.T. Bonner

    1987-01-01

    Immature cones of longleaf pine (Pinus palustris Mill.) can be stored for at least 5 weeks without adversely affecting extraction or seed quality. Cone moisture should be below 50 percent before using heat to open cones.

  2. Optimization of cone target geometry for fast ignition

    SciTech Connect

    Nakamura, Tatsufumi; Sakagami, Hitoshi; Johzaki, Tomoyuki; Nagatomo, Hideo; Mima, Kunioki; Koga, James

    2007-10-15

    Electron energy characteristics generated by the irradiation of ultraintense laser pulses onto solid targets are controlled by using cone targets. Two parameters characterizing the laser-cone interaction are introduced, which are cone angle and the ratio of the laser spot size to the cone tip size. By changing these parameters, the energy absorption rate, laser irradiance at the cone tip, and electron acceleration at the cone tip and side wall are controlled. The optimum cone targets for fast ignition are 30 deg. cone angle with double-cone geometry, and a tip size comparable to the core size, with the irradiation of a laser pulse with a spot size of about four times the cone tip size. Cone targets have the possibility to enhance the maximum energy of laser-accelerated protons by using a smaller angle cone depending on the laser f-number.

  3. 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.

  4. 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...

  5. 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.

  6. 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...

  7. Stability of hypersonic compression cones

    NASA Astrophysics Data System (ADS)

    Reed, Helen; Kuehl, Joseph; Perez, Eduardo; Kocian, Travis; Oliviero, Nicholas

    2012-11-01

    Our activities focus on the identification and understanding of the second-mode instability for representative configurations in hypersonic flight. These include the Langley 93-10 flared cone and the Purdue compression cone, both at 0 degrees angle of attack at Mach 6. Through application of nonlinear parabolized stability equations (NPSE) and linear parabolized stability equations (PSE) to both geometries, it is concluded that mean-flow distortion tends to amplify frequencies less than the peak frequency and stabilize those greater by modifying the boundary-layer thickness. As initial disturbance amplitude is increased and/or a broad spectrum disturbance is introduced, direct numerical simulations (DNS) or NPSE appear to be the proper choices to model the evolution, and relative evolution, because these computational tools include these nonlinear effects (mean-flow distortion). Support from AFOSR/NASA National Center for Hypersonic Research in Laminar-Turbulent Transition through Grant FA9550-09-1-0341 is gratefully acknowledged. The authors also thank Pointwise, AeroSoft, and Texas Advanced Computing Center (TACC).

  8. Penetrant-Indication-Measuring Compass

    NASA Technical Reports Server (NTRS)

    Schaefer, Lloyd

    1991-01-01

    Modified drafting compass well suited to measurement of length of crack or width of area stained by penetrant-dye-inspection method. Equipped with any of variety of standard curved or straight pointed tips. Modification consists in coating tips with dye that fluoresces light pink under same ultraviolet inspection light causing penetrant dye to fluoresce yellow green. Used in locations inaccessible to conventional fluorescent comparator. Eliminates errors of optical distortion in comparator, also eliminates errors of interpolation.

  9. 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

  10. Penetration through the Skin Barrier.

    PubMed

    Nielsen, Jesper Bo; Benfeldt, Eva; Holmgaard, Rikke

    2016-01-01

    The skin is a strong and flexible organ with barrier properties essential for maintaining homeostasis and thereby human life. Characterizing this barrier is the ability to prevent some chemicals from crossing the barrier while allowing others, including medicinal products, to pass at varying rates. During recent decades, the latter has received increased attention as a route for intentionally delivering drugs to patients. This has stimulated research in methods for sampling, measuring and predicting percutaneous penetration. Previous chapters have described how different endogenous, genetic and exogenous factors may affect barrier characteristics. The present chapter introduces the theory for barrier penetration (Fick's law), and describes and discusses different methods for measuring the kinetics of percutaneous penetration of chemicals, including in vitro methods (static and flow-through diffusion cells) as well as in vivo methods (microdialysis and microperfusion). Then follows a discussion with examples of how different characteristics of the skin (age, site and integrity) and of the penetrants (size, solubility, ionization, logPow and vehicles) affect the kinetics of percutaneous penetration. Finally, a short discussion of the advantages and challenges of each method is provided, which will hopefully allow the reader to improve decision making and treatment planning, as well as the evaluation of experimental studies of percutaneous penetration of chemicals. © 2016 S. Karger AG, Basel.

  11. THE PENETRATION OF STRONG ELECTROLYTES

    PubMed Central

    Cooper, W. C.; Dorcas, M. J.; Osterhout, W. J. V.

    1929-01-01

    The entrance of strong electrolytes into Valonia is very slow unless the cells are injured. This, together with the very high electrical resistance of the protoplasm, suggests that they may penetrate largely as undissociated molecules formed at the surface of the protoplasm by the collision of ions. Under favorable circumstances KCl may be absorbed to the extent of 3 x 10–8 mols per hour per sq. cm. of surface together with about 0.17 as much NaCl. Other substances which seem to penetrate to some extent are Li, Rb, Br, BrO3, I, IO3, and selenite. Little or no penetration is shown by SCN, ferricyanide, ferrocyanide, formate, salicylate, tungstate, seleniate, NO2, SO3, Sb, glycerophosphate, and many heavy metals and the alkaline earths. In sea water whose specific gravity had been increased by CsCl cells of Valonia floated for over a year and there was little or no penetration of Cs except as the result of injury. The penetration of NH4Cl decreases the specific gravity of the sap and causes the cells to float: under these circumstances they live indefinitely. It is probable that NH3 or NH4OH penetrates and is subsequently changed to NH4Cl. It would seem that if the sea contained a little more ammonia this would be a floating organism. PMID:19872471

  12. Is Color Experience Cognitively Penetrable?

    PubMed

    Brogaard, Berit; Gatzia, Dimitria E

    2017-01-01

    Is color experience cognitively penetrable? Some philosophers have recently argued that it is. In this paper, we take issue with the claim that color experience is cognitively penetrable. We argue that the notion of cognitive penetration that has recently dominated the literature is flawed since it fails to distinguish between the modulation of perceptual content by non-perceptual principles and genuine cognitive penetration. We use this distinction to show that studies suggesting that color experience can be modulated by factors of the cognitive system do not establish that color experience is cognitively penetrable. Additionally, we argue that even if color experience turns out to be modulated by color-related beliefs and knowledge beyond non-perceptual principles, it does not follow that color experience is cognitively penetrable since the experiences of determinate hues involve post-perceptual processes. We conclude with a brief discussion of the implications that these ideas may have on debates in philosophy. Copyright © 2016 Cognitive Science Society, Inc.

  13. 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

  14. 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

  15. Cone calorimeter evaluation of wood products

    Treesearch

    Robert H. White; Mark A. Dietenberger

    2004-01-01

    The Forest Products Laboratory uses the cone calorimeter for the initial evaluation of the flammability of untreated and fire retardant treated wood products. The results of various studies are reviewed using a model presented at the 12th Annual BBC Conference on Flame Retardancy. The model uses data from the cone calorimeter to provide measures of fire growth...

  16. A Hydraulically Operated Pine Cone Cutter

    Treesearch

    Carl W. Fatzinger; M.T. Proveaux

    1971-01-01

    Mature cones of slash pine (Pinus elliottii Engelm. var. elliottii) and longleaf pine (P. palustris Mill.) can be easily bisected along their longitudinal axes with the hydraulic pine cone cutter described. This cutter eliminates the two major problems of earlier models--undue operator fatigue and the...

  17. 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.

  18. 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.

  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. 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

  1. 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.

  2. 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.

  3. Shatter cone and microscopic shock-alteration evidence for a post-Paleoproterozoic terrestrial impact structure near Santa Fe, New Mexico, USA

    NASA Astrophysics Data System (ADS)

    Fackelman, Siobhan P.; Morrow, Jared R.; Koeberl, Christian; McElvain, Thornton H.

    2008-06-01

    Field mapping, morphologic description, and petrographic analysis of recently discovered shatter cones within Paleoproterozoic crystalline rocks exposed over an area > 5 km 2, located ˜ 8 km northeast of Santa Fe, New Mexico, USA, give robust evidence of a previously unrecognized terrestrial impact structure. Herein, we provisionally name this the "Santa Fe impact structure". The shatter cones are composed of nested sub-conical, curviplanar, and flat joint surfaces bearing abundant curved and bifurcating striations that strongly resemble the multiply striated joint surfaces (MSJS) documented from shatter cones at Vredefort dome. The cones occur as a penetrative feature in intrusive igneous and supracrustal metamorphic rocks, are unusually large (up to 2 m long and 0.5 m wide at the base), display upward-pointing apices, and have subvertical, northeastward-plunging axes that crosscut regional host-rock fabrics. Key characteristics of superficially similar, but non-shock-generated conical and striated features are inconsistent with the properties of the Santa Fe cones. In thin section, sub-millimeter-scale, dark, semi-opaque to isotropic veneers on cone surfaces and veinlets within cone interiors closely resemble previously described shock-induced melt features. Microscopic grain alteration, restricted generally to within 1 mm of the cone surfaces, includes random fractures, fluid micro-inclusions, sericite replacement in feldspar, rare kink bands in mica, optical mosaicism, and decorated planar fractures (PFs) and planar deformation features (PDFs) in quartz. The PFs and PDFs are dominated by a basal (0001) crystallographic orientation, which indicate a peak shock pressure of ˜ 5-10 GPa that is consistent with shatter cone formation. Regional structural and exhumation models, together with anomalous breccia units that overlie and crosscut the shatter cone-bearing rocks, may provide additional age constraints for the impact event. The observed shatter cone outcrop

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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.

  11. Penetration analysis of projectile with inclined concrete target

    NASA Astrophysics Data System (ADS)

    Kim, S. B.; Kim, H. W.; Yoo, Y. H.

    2015-09-01

    This paper presents numerical analysis result of projectile penetration with concrete target. We applied dynamic material properties of 4340 steels, aluminium and explosive for projectile body. Dynamic material properties were measured with static tensile testing machine and Hopkinson pressure bar tests. Moreover, we used three concrete damage models included in LS-DYNA 3D, such as SOIL_CONCRETE, CSCM (cap model with smooth interaction) and CONCRETE_DAMAGE (K&C concrete) models. Strain rate effect for concrete material is important to predict the fracture deformation and shape of concrete, and penetration depth for projectiles. CONCRETE_DAMAGE model with strain rate effect also applied to penetration analysis. Analysis result with CSCM model shows good agreement with penetration experimental data. The projectile trace and fracture shapes of concrete target were compared with experimental data.

  12. The Penetration of Fragments into Collection Media

    DTIC Science & Technology

    1989-01-01

    S_1-2(v/v )a dv1 (vo) = vl d0( represents the integral on the right in equation 4. In Collins’ test, the impact medium was Celotex , with a density of...8217 calibration data (Table A-I) gives v and P for numerous shots of the steel spheres into the Celotex impact medium. Tests yielding penetrations of...fragments impacting the Celotex impact medium. Collins’ data for small fragments (approximately the same mass as the calibration spheres), presented

  13. Influence of some plant extracts on the transdermal absorption and penetration of marker penetrants.

    PubMed

    Muhammad, Faqir; Wiley, June; Riviere, Jim E

    2017-03-01

    Plant extracts are commonly used in a number of cosmetics and topical pharmaceuticals. The effects on such extracts on the subsequent dermal absorption and penetration of other cosmetic ingredients needs to be evaluated. This study demonstrates the effect of some natural extracts routinely found in cosmetics on the dermal absorption and penetration of marker penetrants. Aqueous ethanolic extracts of Gingko biloba, Lavendula angustifolia, Rosmarinus officinale, Mentha piperita, Matricaria recutita, Persea Americana, Avena sativa, Zingiber officinale were prepared. (14)C-caffeine and (14)C-salicylic acid were topically dosed with either 10% solutions of natural extracts or ethanol (control) using a flow through in vitro porcine skin diffusion system. Samples were analyzed with liquid scintillation counter. The parameters of flux, permeability, and percent dose absorbed/retained were calculated and compared. The dermal absorption of (14)C-caffeine was significantly higher (p ≥ 0.05) with avocado, chamomile, ginger and peppermint extract as compared to the control ethanol; while dermal absorption of (14)C-salicylic acid was significantly greater with ginkgo and chamomile extract as compared to ethanol. Over four fold increase in flux and permeability of caffeine with avocado extract was observed while chamomile and peppermint extracts increased the flux and permeability of caffeine over three fold. Gingko and chamomile extracts increased salicylic acid's flux and permeability by two fold. Sum of %dose skin residue + %absorption in receptor fluid for different extracts exhibited the similar trend as shown by flux and permeability. The other natural extracts tested did not produce statistically significant effects on dermal penetration parameters for both caffeine and salicylic acid (p ≥ 0.05). These results emphasize the influence of natural plant extracts on the transdermal penetration of hydrophilic (caffeine) and hydrophobic (salicylic acid

  14. 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.

  15. 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

  16. 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.

  17. 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

  18. Elastic cone for Chinese calligraphy

    NASA Astrophysics Data System (ADS)

    Cai, Fenglei; Li, Haisheng

    2014-01-01

    The brush plays an important role in creating Chinese calligraphy. We regard a single bristle of a writing brush as an elastic rod and the brush tuft absorbing ink as an elastic cone, which naturally deforms according to the force exerted on it when painting on a paper, and the brush footprint is formed by the intersection region between the deformed tuft and the paper plane. To efficiently generate brush strokes, this paper introduces interpolation and texture mapping approach between two adjacent footprints, and automatically applies bristle-splitting texture to the stroke after long-time painting. Experimental results demonstrate that our method is effective and reliable. Users can create realistic calligraphy in real time.

  19. Rates of volcanic CO2 degassing from airborne determinations of SO2 Emission rates and plume CO2SO2: test study at Pu′u ′O′o Cone, Kilauea Volcano, Hawaii

    USGS Publications Warehouse

    Gerlach, Terrence M.; McGee, Kenneth A.; Sutton, A. Jefferson; Elias, Tamar

    1998-01-01

    We present an airborne method that eliminates or minimizes several disadvantages of the customary plume cross-section sampling method for determining volcanic CO2 emission rates. A LI-COR CO2analyzer system (LICOR), a Fourier transform infrared spectrometer system (FTIR), and a correlation spectrometer (COSPEC) were used to constrain the plume CO2/SO2 and the SO2 emission rate. The method yielded a CO2 emission rate of 300 td−1 (metric tons per day) for Pu′u ′O′o cone, Kilauea volcano, on 19 September 1995. The CO2/SO2 of 0.20 determined from airborne LICOR and FTIR plume measurements agreed with the CO2/SO2 of 204 ground-based samples collected from vents over a 14-year period since the Pu′u ′O′o eruption began in January 1983.

  20. A parallel-cone collimator for high-energy SPECT.

    PubMed

    Beijst, Casper; Elschot, Mattijs; Viergever, Max A; de Jong, Hugo W A M

    2015-03-01

    In SPECT using high-energy photon-emitting isotopes, such as (131)I, parallel-hole collimators with thick septa are required to limit septal penetration, at the cost of sensitivity and resolution. This study investigated a parallel-hole collimator with cone-shaped holes, which was designed to limit collimator penetration while preserving resolution and sensitivity. The objective was to demonstrate that a single-slice prototype of the parallel-cone (PC) collimator was capable of improving the image quality of high-energy SPECT. The image quality of the PC collimator was quantitatively compared with that of clinically used low-energy high-resolution (LEHR; for (99m)Tc) and high-energy general-purpose (HEGP; for (131)I and (18)F) parallel-hole collimators. First, Monte Carlo simulations of single and double point sources were performed to assess sensitivity and resolution by comparing point-spread functions (PSFs). Second, a prototype PC collimator was used in an experimental phantom study to assess and compare contrast recovery coefficients and image noise. Monte Carlo simulations showed reduced broadening of the PSF due to collimator penetration for the PC collimator as compared with the HEGP collimator (e.g., 0.9 vs. 1.4 cm in full width at half maximum for (131)I). Simulated double point sources placed 2 cm apart were separately detectable for the PC collimator, whereas this was not the case for (131)I and (18)F at distances from the collimator face of 10 cm or more for the HEGP collimator. The sensitivity, measured over the simulated profiles as the total amount of counts per decay, was found to be higher for the LEHR and HEGP collimators than for the PC collimator (e.g., 3.1 × 10(-5) vs. 2.9 × 10(-5) counts per decay for (131)I). However, at equal noise level, phantom measurements showed that contrast recovery coefficients were similar for the PC and LEHR collimators for (99m)Tc but that the PC collimator significantly improved the contrast recovery