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Sample records for cone penetrometer final

  1. Vacuum Compatible Percussive Dynamic Cone Penetrometer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Honeybee Robotics proposes to develop a vacuum compatible percussive dynamic cone penetrometer (PDCP), for establishing soil bin characteristics, with the ultimate...

  2. Cone penetrometer comparison testing.

    Science.gov (United States)

    2011-01-01

    A total of 61 cone penetration tests were performed at 14 sites in the state of Wisconsin. Data : reinforced conclusions from practice in Minnesota and previously performed test programs : related to the Marquette Interchange and Mitchell interchange...

  3. Cone Penetrometer N Factor Determination Testing Results

    Energy Technology Data Exchange (ETDEWEB)

    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.

  4. Cone penetrometer moisture probe acceptance test report

    Energy Technology Data Exchange (ETDEWEB)

    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).

  5. Power Analysis of an Automated Dynamic Cone Penetrometer

    Science.gov (United States)

    2015-09-01

    ARL-TR-7494 ● SEP 2015 US Army Research Laboratory Power Analysis of an Automated Dynamic Cone Penetrometer by C Wesley...Automated Dynamic Cone Penetrometer by C Wesley Tipton IV and Donald H Porschet Sensors and Electron Devices Directorate, ARL...Dynamic Cone Penetrometer 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) C Wesley Tipton IV and Donald H

  6. Cone penetrometer: Innovative technology summary report

    International Nuclear Information System (INIS)

    1996-04-01

    Cone penetrometer technology (CPT) provides cost-effective, real-time data for use in the characterization of the subsurface. Recent innovations in this baseline technology allow for improved access to the subsurface for environmental restoration applications. The technology has been improved by both industry and government agencies and is constantly advancing due to research efforts. The U.S. Department of Energy (DOE) Office of Science and Technology (formerly Technology Development) has contributed significantly to these efforts. This report focuses on the advancements made in conjunction with DOE's support but recognizes Department of Defense (DOD) and industry efforts

  7. Apparatus and process for an off-surface cone penetrometer sensor

    Science.gov (United States)

    Smail, Timothy R.; French, Phillip J.; Huffman, Russell K.

    2003-04-29

    A cone penetrometer is provided having a pivoting arm which deploys a variable distance from the surface of the cone penetrometer. Sensors placed on the end of the deployable arm provide for data collection outside a compression zone created by the insertion of the cone penetrometer.

  8. A microelectromechanical system digital 3C array seismic cone penetrometer

    NARCIS (Netherlands)

    Ghose, R.

    2012-01-01

    A digital 3C array seismic cone penetrometer has been developed for multidisciplinary geophysical and geotechnical applications. Seven digital triaxial microelectromechanical system accelerometers are installed at 0.25-m intervals to make a 1.5-m-long downhole seismic array. The accelerometers have

  9. Engineering task plan HTI [Hanford Tank Initiative] cone penetrometer

    International Nuclear Information System (INIS)

    Krieg, S.A.

    1998-01-01

    The Hanford Cone Penetrometer Platform (CPP) will be used to insert instrumented and soil sampling probes into the soil adjacent to Tank AX-104 to assist in characterizing the waste plume. The scope, deliverables, roles and responsibilities, safety, and environmental considerations are presented in the task plan

  10. Cone Penetrometer Load Cell Temperature and Radiation Testing Results

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Miniature GC for in-situ monitoring of VOC's within a cone penetrometer. Final report, July 1994--May 1996

    International Nuclear Information System (INIS)

    1996-01-01

    The open-quotes Cone-GCclose quotes was developed in response to a need for down hole, in-situ characterization of volatile organics within the soil profile, in the vadose zone, or a water headspace. A design based on the use of a miniature gas chromatograph was selected since it was believed that such an instrument would be adaptable to a broad range of analytes and could be used in complex, real-world situations where the environmental contaminants to be monitored may exist in complex mixtures with other vapors. The Cone-GC is versatile and will also fit within many other soil probes, hole liners, and minimally intrusive emplacement systems where small size in addition to high performance are required. The Cone-GC was designed to allow environmental specialists for the first time to obtain immediate, in-situ chemical measurements in a soil probe and to make real-time, on-site decisions that will greatly reduce the time (and cost) of site characterization and remediation. It will no longer be necessary to collect samples (using long sampling lines that may become contaminated), send them to an off-site laboratory for analysis, and then wait hours or days for results

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

    Science.gov (United States)

    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.

  13. Work plan for cone penetrometer comparison testing.

    Science.gov (United States)

    2011-01-01

    The work plan and experimental design are developed around aiding engineers and geologists within the : Wisconsin Department of Transportation to understand the mechanisms controlling cone penetration test : results so that they can decide when the t...

  14. Cone penetrometer fiber optic raman spectroscopy probe assembly

    Science.gov (United States)

    Kyle, Kevin R.; Brown, Steven B.

    2000-01-01

    A chemically and mechanically robust optical Raman spectroscopy probe assembly that can be incorporated in a cone penetrometer (CPT) for subsurface deployment. This assembly consists of an optical Raman probe and a penetrometer compatible optical probe housing. The probe is intended for in-situ chemical analysis of chemical constituents in the surrounding environment. The probe is optically linked via fiber optics to the light source and the detection system at the surface. A built-in broadband light source provides a strobe method for direct measurement of sample optical density. A mechanically stable sapphire window is sealed directly into the side-wall of the housing using a metallic, chemically resistant, hermetic seal design. This window permits transmission of the interrogation light beam and the resultant signal. The spectroscopy probe assembly is capable of accepting Raman, Laser induced Fluorescence, reflectance, and other optical probes with collimated output for CPT deployment.

  15. A 40-foot static cone penetrometer

    Science.gov (United States)

    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.

  16. MEASUREMENT OF TEXTURAL PROPERTIES OF FOODS WITH A CONSTANT SPEED CONE PENETROMETER.

    Science.gov (United States)

    Tanaka, M; DE Man, J M; Voisey, P W

    1971-09-01

    A constant speed cone penetrometer was used to measure textural properties of a variety of foods. Apparent viscosity and yield value were calculated from the recorded relationships of penetrating force and depth. Good agreement was found between yield values determined by this method and those obtained with a constant weight cone penetrometer.

  17. Grouting guidelines for Hanford Tanks Initiative cone penetrometer borings

    International Nuclear Information System (INIS)

    Iwatate, D.F.

    1998-01-01

    Grouting of an open cone penetrometer (CP) borehole is done to construct a barrier that prevents the vertical migration of fluids and contaminants between geologic units and aquifers intersected by the boring. Whether to grout, the types of grout, and the method of deployment are functions of the site-specific conditions. This report recommends the strategy that should be followed both before and during HTI [Hanford Tanks Initiative] CP deployment to decide specific borehole grouting needs at Hanford SST farms. Topics discussed in this report that bear on this strategy include: Regulatory guidance, hydrogeologic conditions, operational factors, specific CP grouting deployment recommendations

  18. HTI CONE PENETROMETER PROBES PREPARATION DEVELOPMENTAL TESTING REPORT

    Energy Technology Data Exchange (ETDEWEB)

    IWATATE, D.F.

    1998-10-26

    The HTI subsurface characterization task will use the Hanford Cone Penetrometer platform (CPP) to deploy soil sensor and sampling probes into the vadose zone/soils around AX-104 during FY-99. This report provides the data and information compiled during vendor field development tests and laboratory/bench checkout. This document is a vendor deliverable item identified in the ARA Statement of Work HNF-2881, Revision 1. This version of the DTR includes to-be-determined items and some incomplete sections. The Rev. 0 is being released to support the concurrent task of procedure preparation and Qualification Test Plan preparation. Revision 1 is planned to contain all data and information.

  19. Grouting guidelines for Hanford Tanks Initiative cone penetrometer borings

    Energy Technology Data Exchange (ETDEWEB)

    Iwatate, D.F.

    1998-05-18

    Grouting of an open cone penetrometer (CP) borehole is done to construct a barrier that prevents the vertical migration of fluids and contaminants between geologic units and aquifers intersected by the boring. Whether to grout, the types of grout, and the method of deployment are functions of the site-specific conditions. This report recommends the strategy that should be followed both before and during HTI [Hanford Tanks Initiative] CP deployment to decide specific borehole grouting needs at Hanford SST farms. Topics discussed in this report that bear on this strategy include: Regulatory guidance, hydrogeologic conditions, operational factors, specific CP grouting deployment recommendations.

  20. Implementation of LRFD geotechnical design for deep foundations using Texas Cone Penetrometer (TCP) test.

    Science.gov (United States)

    2015-09-01

    This study provides resistance factors (I) for design of deep foundations to implement Load and Resistance Factor Design (LRFD) for bridge foundations using Texas Cone Penetrometer (TCP) Test data. Initial efforts were made to determine resistance fa...

  1. Improved correlation between Texas cone penetrometer blow count and undrained shear strength of soft clays.

    Science.gov (United States)

    2009-01-01

    The objective of this project was to develop an improved correlation between Texas Cone Penetrometer (TCP) : blow count and undrained shear strength for soft, clay soils in the upper approximately 30 feet of the ground. Subsurface : explorations were...

  2. Evaluation of Cone Penetrometer Data for Permeability Correlation at the Savannah River Site

    International Nuclear Information System (INIS)

    Harris, M.K.

    1997-02-01

    This report documents the results of an assessment of cone penetrometer technology (CPT) use at the Savannah River Site. The study is intended to provide valuable insight into methods of increasing the utility of CPT data for site characterization

  3. Evaluation of Cone Penetrometer Data for Permeability Correlation at the Savannah River Site

    Energy Technology Data Exchange (ETDEWEB)

    Harris, M.K. [Westinghouse Savannah River Company, AIKEN, SC (United States)

    1997-02-01

    This report documents the results of an assessment of cone penetrometer technology (CPT) use at the Savannah River Site. The study is intended to provide valuable insight into methods of increasing the utility of CPT data for site characterization.

  4. Development of a Cone Penetrometer for Measuring Spectral Characteristics of Soils in Situ

    Science.gov (United States)

    Lee, Landris T., Jr.; Malone, Philip G.

    1993-01-01

    A patent was recently granted to the U.S. Army for an adaptation of a soil cone penetrometer that can be used to measure the spectral characteristics (fluorescence or reflectance) of soils adjacent to the penetrometer rod. The system can use a variety of light sources and spectral analytical equipment. A laser induced fluorescence measuring system has proven to be of immediate use in mapping the distribution of oil contaminated soil at waste disposal and oil storage areas. The fiber optic adaptation coupled with a cone penetrometer permits optical characteristics of the in-situ soil to be measured rapidly, safely, and inexpensively. The fiber optic cone penetrometer can be used to gather spectral data to a depth of approximately 25 to 30 m even in dense sands or stiff clays and can investigate 300 m of soil per day. Typical detection limits for oil contamination in sand is on the order of several hundred parts per million.

  5. A simple approach to enhance multiprobe soil cone penetrometer analyses

    Science.gov (United States)

    Soil penetrometers are used to characterize soil strength measurements for many applications related to soil conservation and management using statistical analyses of depths and row positions combined with contour graphs. Our objective was to demonstrate a method to quantify soil strength differenc...

  6. R Reactor seepage basins soil moisture and resistivity field investigation using cone penetrometer technology, Savannah River Site, Aiken, South Carolina

    International Nuclear Information System (INIS)

    Harris, M.K.

    2000-01-01

    The focus of this report is the summer 1999 investigation of the shallow groundwater system using cone penetrometer technology characterization methods to determine if the water table is perched beneath the R Reactor Seepage Basins (RRSBs)

  7. R Reactor seepage basins soil moisture and resistivity field investigation using cone penetrometer technology, Savannah River Site, Aiken, South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Harris, M.K.

    2000-02-17

    The focus of this report is the summer 1999 investigation of the shallow groundwater system using cone penetrometer technology characterization methods to determine if the water table is perched beneath the R Reactor Seepage Basins (RRSBs).

  8. Hanford Tanks Initiative AX tank farm cone penetrometer demonstration training plan

    International Nuclear Information System (INIS)

    Iwatate, D.F.

    1998-01-01

    The HTI subsurface characterization task will use the Hanford Cone Penetrometer platform (CPP) to deploy soil sensor and sampling probes into the vadose zone/soils around AX-104 during FY-99. This training plan identifies training requirements in support of the HTI task, describes specific staff training needs, and identifies how the training will be provided and by whom. Documentation of training completion is also described

  9. Maintenance of the Hanford cone penetrometer platform during fiscal year 1999

    Energy Technology Data Exchange (ETDEWEB)

    IWATATE, D.F.

    1998-11-30

    This SOW describes services requested of Applied Research and Associates, Inc. (ARA), as a commercial provider of cone penetrometer equipment and services, to provide routine inspection and minimum preventive maintenance on the Hanford CP Platform (CPP) during Fiscal Year 1999. This SOW specifically pertains to the maintenance of the CPP and associated support equipment and is limited in scope to routine preventive maintenance and identification of any deficiencies. ARA is the original manufacturer of the CPP and will conduct this work following the vendor-prepared maintenance schedule.

  10. Maintenance of the Hanford cone penetrometer platform during fiscal year 1999

    International Nuclear Information System (INIS)

    IWATATE, D.F.

    1998-01-01

    This SOW describes services requested of Applied Research and Associates, Inc. (ARA), as a commercial provider of cone penetrometer equipment and services, to provide routine inspection and minimum preventive maintenance on the Hanford CP Platform (CPP) during Fiscal Year 1999. This SOW specifically pertains to the maintenance of the CPP and associated support equipment and is limited in scope to routine preventive maintenance and identification of any deficiencies. ARA is the original manufacturer of the CPP and will conduct this work following the vendor-prepared maintenance schedule

  11. Hydrogeologic structure underlying a recharge pond delineated with shear-wave seismic reflection and cone penetrometer data

    Science.gov (United States)

    Haines, S.S.; Pidlisecky, Adam; Knight, R.

    2009-01-01

    With the goal of improving the understanding of the subsurface structure beneath the Harkins Slough recharge pond in Pajaro Valley, California, USA, we have undertaken a multimodal approach to develop a robust velocity model to yield an accurate seismic reflection section. Our shear-wave reflection section helps us identify and map an important and previously unknown flow barrier at depth; it also helps us map other relevant structure within the surficial aquifer. Development of an accurate velocity model is essential for depth conversion and interpretation of the reflection section. We incorporate information provided by shear-wave seismic methods along with cone penetrometer testing and seismic cone penetrometer testing measurements. One velocity model is based on reflected and refracted arrivals and provides reliable velocity estimates for the full depth range of interest when anchored on interface depths determined from cone data and borehole drillers' logs. A second velocity model is based on seismic cone penetrometer testing data that provide higher-resolution ID velocity columns with error estimates within the depth range of the cone penetrometer testing. Comparison of the reflection/refraction model with the seismic cone penetrometer testing model also suggests that the mass of the cone truck can influence velocity with the equivalent effect of approximately one metre of extra overburden stress. Together, these velocity models and the depth-converted reflection section result in a better constrained hydrologic model of the subsurface and illustrate the pivotal role that cone data can provide in the reflection processing workflow. ?? 2009 European Association of Geoscientists & Engineers.

  12. Evaluation of an In Situ, On-Line Purging System for the Cone Penetrometer.

    Science.gov (United States)

    Doskey, Paul V; Aldstadt, Joseph H; Kuo, Jacqueline M; Costanza, Molly S

    1996-11-01

    Materials that will be used to construct an in situ, on-line purging system for the cone penetrometer were evaluated. Transfer efficiencies for volatile organic compounds (VOCs) through stainless steel, nickel, aluminum, and Teflon® tubings were determined using a gas-phase mixture of VOCs containing trichloromethane, tetrachloromethane, 1,1,1- trichloroethane, tetrachloroethene, hexane, benzene, toluene, and 1,2-dimethylbenzene. The water content of the gas stream had an insignificant effect on the quantitative transfer of VOCs through Teflon® tubing but was critical to efficiently transfer the compounds through metal tubing, particularly nickel. Transfer efficiencies for all eight analytes in moist gas streams through stainless steel were greater than 95%. Toluene, tetrachloroethene, and 1,2-dimethylbenzene were transferred with 93%, 81%, and 80% efficiency, respectively, when they were drawn through Teflon® PFA (perfluoroalkoxy) tubing. In general, the retention of the VOCs by Teflon® increases with decreasing aqueous solubility of the analyte. The efficiencies at which VOCs were purged from aqueous standards in Teflon® PFA, Type 304 stainless steel, and glass vessels were similar. Stainless steel was superior to nickel, aluminum, and the Teflon® polymers as a material for an in situ, on-line purging system for the cone penetrometer.

  13. Cone Penetrometer Shear Strength Measurements of Sludge Waste in Tanks 241-AN-101 and 241-AN-106

    Energy Technology Data Exchange (ETDEWEB)

    Follett, Jordan R.

    2014-03-06

    This document presents the resulting shear strength profiles for sludge waste in Tanks 241-AN-101 and 241-AN-106, as determined with a full-flow cone penetrometer. Full-flow penetrometer measurements indicate shear strength profiles that increase roughly uniformly with depth. For Tank 241-AN-101, the undrained shear strength was calculated to range from 500 Pa near the sludge surface to roughly 3,300 Pa at 15 inches above the tank bottom. For 241-AN-106, the undrained shear strength was calculated to range from 500 Pa near the sludge surface to roughly 5,000 Pa at 15 inches above the tank bottom.

  14. Cone penetrometer tests and HydroPunch sampling: A screening technique for plume definition

    International Nuclear Information System (INIS)

    Smolley, M.; Kappmeyer, J.C.

    1991-01-01

    Cone penetrometer tests and HydroPunch sampling were used to define the extent of volatile organic compounds in ground water. The investigation indicated that the combination of the these techniques is effective for obtaining ground water samples for preliminary plume definition. HydroPunch samples can be collected in unconsolidated sediments and the analytical results obtained from these samples are comparable to those obtained from adjacent monitoring wells. This sampling method is a rapid and cost-effective screening technique for characterizing the extent of contaminant plumes in soft sediment environments. Use of this screening technique allowed monitoring wells to be located at the plume boundary, thereby reducing the number of wells installed and the overall cost of the plume definition program

  15. Resilient modulus prediction of soft low-plasticity Piedmont residual soil using dynamic cone penetrometer

    Directory of Open Access Journals (Sweden)

    S. Hamed Mousavi

    2018-04-01

    Full Text Available Dynamic cone penetrometer (DCP has been used for decades to estimate the shear strength and stiffness properties of the subgrade soils. There are several empirical correlations in the literature to predict the resilient modulus values at only a specific stress state from DCP data, corresponding to the predefined thicknesses of pavement layers (a 50 mm asphalt wearing course, a 100 mm asphalt binder course and a 200 mm aggregate base course. In this study, field-measured DCP data were utilized to estimate the resilient modulus of low-plasticity subgrade Piedmont residual soil. Piedmont residual soils are in-place weathered soils from igneous and metamorphic rocks, as opposed to transported or compacted soils. Hence the existing empirical correlations might not be applicable for these soils. An experimental program was conducted incorporating field DCP and laboratory resilient modulus tests on “undisturbed” soil specimens. The DCP tests were carried out at various locations in four test sections to evaluate subgrade stiffness variation laterally and with depth. Laboratory resilient modulus test results were analyzed in the context of the mechanistic-empirical pavement design guide (MEPDG recommended universal constitutive model. A new approach for predicting the resilient modulus from DCP by estimating MEPDG constitutive model coefficients (k1, k2 and k3 was developed through statistical analyses. The new model is capable of not only taking into account the in situ soil condition on the basis of field measurements, but also representing the resilient modulus at any stress state which addresses a limitation with existing empirical DCP models and its applicability for a specific case. Validation of the model is demonstrated by using data that were not used for model development, as well as data reported in the literature. Keywords: Dynamic cone penetrometer (DCP, Resilient modulus, Mechanistic-empirical pavement design guide (MEPDG, Residual

  16. Cone Penetrometer for Subsurface Heavy Metals Detection. Semiannual report, November 1, 1996--March 31, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Grisanti, Ames A.; Timpe, Ronald C.; Foster, H.J.; Eylands, Kurt E.; Crocker, Charlene R.

    1997-12-31

    Surface and subsurface contamination of soils by heavy metals, including Pb, Cr, Cu, Zn, and Cd, has become an area of concern for many industrial and government organizations (1). Conventional sampling and analysis techniques for soil provide a high degree of sensitivity and selectivity for individual analytes. However, obtaining a representative sampling and analysis from a particular site using conventional techniques is time consuming and costly (2). Additionally, conventional methods are difficult to implement in the field for in situ and/or real-time applications. Therefore, there is a need for characterization and monitoring techniques for heavy metals in soils which allow cost-effective, rapid, in situ measurements. Laser-induced breakdown spectroscopy (LIBS) has been used to successfully measure metals content in a variety of matrices (3-15) including soil (16,17). Under the Department of Energy (DOE) Federal Energy Technology Center (FETC) Industry Program, Science {ampersand} Engineering Associates (SEA) is developing a subsurface cone penetrometer (CPT) probe for heavy metals detection that employs LIBS (18). The LIES-CPT unit is to be applied to in situ, real-time sampling and analysis of heavy metals in soil. As part of its contract with DOE FETC, SEA is scheduled to field test its LIBS-CPT system in September 1997.

  17. Cone Penetrometer for Subsurface Heavy Metals Detection. Semiannual report, November 1, 1996--March 31, 1997

    International Nuclear Information System (INIS)

    Grisanti, Ames A.; Timpe, Ronald C.; Foster, H.J.; Eylands, Kurt E.; Crocker, Charlene R.

    1997-01-01

    Surface and subsurface contamination of soils by heavy metals, including Pb, Cr, Cu, Zn, and Cd, has become an area of concern for many industrial and government organizations (1). Conventional sampling and analysis techniques for soil provide a high degree of sensitivity and selectivity for individual analytes. However, obtaining a representative sampling and analysis from a particular site using conventional techniques is time consuming and costly (2). Additionally, conventional methods are difficult to implement in the field for in situ and/or real-time applications. Therefore, there is a need for characterization and monitoring techniques for heavy metals in soils which allow cost-effective, rapid, in situ measurements. Laser-induced breakdown spectroscopy (LIBS) has been used to successfully measure metals content in a variety of matrices (3-15) including soil (16,17). Under the Department of Energy (DOE) Federal Energy Technology Center (FETC) Industry Program, Science ampersand Engineering Associates (SEA) is developing a subsurface cone penetrometer (CPT) probe for heavy metals detection that employs LIBS (18). The LIES-CPT unit is to be applied to in situ, real-time sampling and analysis of heavy metals in soil. As part of its contract with DOE FETC, SEA is scheduled to field test its LIBS-CPT system in September 1997

  18. A Geostatistical Toolset for Reconstructing Louisiana's Coastal Stratigraphy using Subsurface Boring and Cone Penetrometer Test Data

    Science.gov (United States)

    Li, A.; Tsai, F. T. C.; Jafari, N.; Chen, Q. J.; Bentley, S. J.

    2017-12-01

    A vast area of river deltaic wetlands stretches across southern Louisiana coast. The wetlands are suffering from a high rate of land loss, which increasingly threats coastal community and energy infrastructure. A regional stratigraphic framework of the delta plain is now imperative to answer scientific questions (such as how the delta plain grows and decays?) and to provide information to coastal protection and restoration projects (such as marsh creation and construction of levees and floodwalls). Through years, subsurface investigations in Louisiana have been conducted by state and federal agencies (Louisiana Department of Natural Resources, United States Geological Survey, United States Army Corps of Engineers, etc.), research institutes (Louisiana Geological Survey, LSU Coastal Studies Institute, etc.), engineering firms, and oil-gas companies. This has resulted in the availability of various types of data, including geological, geotechnical, and geophysical data. However, it is challenging to integrate different types of data and construct three-dimensional stratigraphy models in regional scale. In this study, a set of geostatistical methods were used to tackle this problem. An ordinary kriging method was used to regionalize continuous data, such as grain size, water content, liquid limit, plasticity index, and cone penetrometer tests (CPTs). Indicator kriging and multiple indicator kriging methods were used to regionalize categorized data, such as soil classification. A compositional kriging method was used to regionalize compositional data, such as soil composition (fractions of sand, silt and clay). Stratigraphy models were constructed for three cases in the coastal zone: (1) Inner Harbor Navigation Canal (IHNC) area: soil classification and soil behavior type (SBT) stratigraphies were constructed using ordinary kriging; (2) Middle Barataria Bay area: a soil classification stratigraphy was constructed using multiple indicator kriging; (3) Lower Barataria

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    Pidlisecky, Adam; 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.

  1. Tank 241-AX-104 upper vadose zone cone penetrometer demonstration sampling and analysis plan

    Energy Technology Data Exchange (ETDEWEB)

    FIELD, J.G.

    1999-02-02

    This sampling and analysis plan (SAP) is the primary document describing field and laboratory activities and requirements for the tank 241-AX-104 upper vadose zone cone penetrometer (CP) demonstration. It is written in accordance with Hanford Tank Initiative Tank 241-AX-104 Upper Vadose Zone Demonstration Data Quality Objective (Banning 1999). This technology demonstration, to be conducted at tank 241-AX-104, is being performed by the Hanford Tanks Initiative (HTI) Project as a part of Tank Waste Remediation System (TWRS) Retrieval Program (EM-30) and the Office of Science and Technology (EM-50) Tanks Focus Area. Sample results obtained as part of this demonstration will provide additional information for subsequent revisions to the Retrieval Performance Evaluation (RPE) report (Jacobs 1998). The RPE Report is the result of an evaluation of a single tank farm (AX Tank Farm) used as the basis for demonstrating a methodology for developing the data and analyses necessary to support making tank waste retrieval decisions within the context of tank farm closure requirements. The RPE includes a study of vadose zone contaminant transport mechanisms, including analysis of projected tank leak characteristics, hydrogeologic characteristics of tank farm soils, and the observed distribution of contaminants in the vadose zone in the tank farms. With limited characterization information available, large uncertainties exist as to the nature and extent of contaminants that may exist in the upper vadose zone in the AX Tank Farm. Traditionally, data has been collected from soils in the vadose zone through the installation of boreholes and wells. Soil samples are collected as the bore hole is advanced and samples are screened on site and/or sent to a laboratory for analysis. Some in-situ geophysical methods of contaminant analysis can be used to evaluate radionuclide levels in the soils adjacent to an existing borehole. However, geophysical methods require compensation for well

  2. Development of an Automated Airfield Dynamic Cone Penetrometer (AADCP) Prototype and the Evaluation of Unsurfaced Airfield Seismic Surveying Using Spectral Analysis of Surface Waves (SSW) Technology.

    Science.gov (United States)

    1993-12-01

    Malaysia ," 4th Southeast Asian Conference on Soil Engineering, Kuala Lumpur, Malaysia , 7-10 April 1975, pp. 3-62 - 3-79. Ayers, M. E., Thompson, M...mnwwrowl «rlpl« Flar* Ijrp«. Longth 8.3 ft V« lgbt 1 lb. Signal Duration 7 soo. Figure 2.21 Aerial Penetrometer (Molineux 1955) 58 springs, for...Pavement Design and Evaluation,H Tyndall Air Force Base, 1990. Aun, 0. T., and Hui, T. W., "The Use of a Light Dynamic Cone Penetrometer in Malaysia ," 4th

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

    Science.gov (United States)

    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

  4. EM Task 13 -- Cone penetrometer for subsurface heavy metals detection. Semi-annual report, April 1--September 30, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Grisanti, A.A.; Timpe, R.C.; Foster, H.J.; Eylands, K.E.; Crocker, C.R.

    1997-12-31

    Surface and subsurface contamination of soils by heavy metals, including Pb, Cr, Cu, Zn, and Cd has become an area of concern for many industrial and government organizations. Conventional sampling and analysis techniques for soil provide a high degree of sensitivity and selectivity for individual analytes. However, obtaining a representative sampling and analysis from a particular site using conventional techniques is time-consuming and costly. Additionally, conventional methods are difficult to implement in the field for in situ and/or real-time applications. Therefore, there is a need for characterization and monitoring techniques for heavy metals in soils which allow cost-effective, rapid, in situ measurements. Laser induced breakdown spectroscopy (LIBS) has been used to successfully measure metals content in a variety of matrices including soil. Science and Engineering Associates (SEA) is developing a subsurface cone penetrometer (CPT) probe for heavy metal detection that employs LIBS. The LIBS/CPT unit is to be applied to in situ, real-time sampling and analysis of heavy metals in soil. The overall objectives of this project are to evaluate potential calibration techniques for the LIBS/CPT instrument and to provide a preliminary evaluation of the LIBS instrument calibration using samples obtained from the field.

  5. Soil penetrometer

    Science.gov (United States)

    Howard, E. A.; Hotz, G. M.; Bryson, R. P. (Inventor)

    1968-01-01

    An auger-type soil penetrometer for burrowing into soil formations is described. The auger, while initially moving along a predetermined path, may deviate from the path when encountering an obstruction in the soil. Alterations and modifications may be made in the structure so that it may be used for other purposes.

  6. Cone penetrometer testing and discrete-depth groundwater sampling techniques: A cost-effective method of site characterization in a multiple-aquifer setting

    International Nuclear Information System (INIS)

    Zemo, D.A.; Pierce, Y.G.; Gallinatti, J.D.

    1992-01-01

    Cone penetrometer testing (CPT), combined with discrete-depth groundwater sampling methods, can reduce significantly the time and expense required to characterize large sites that have multiple aquifers. Results from the screening site characterization can be used to design and install a cost-effective monitoring well network. At a site in northern California, it was necessary to characterize the stratigraphy and the distribution of volatile organic compounds (VOCs) to a depth of 80 feet within a 1/2 mile-by-1/4-mile residential and commercial area in a complex alluvial fan setting. To expedite site characterization, a five-week field screening program was implemented that consisted of a shallow groundwater survey, CPT soundings, and discrete-depth groundwater sampling. Based on continuous lithologic information provided by the CPT soundings, four coarse-grained water-yielding sedimentary packages were identified. Eighty-three discrete-depth groundwater samples were collected using shallow groundwater survey techniques, the BAT Enviroprobe, or the QED HydroPunch 1, depending on subsurface conditions. A 20-well monitoring network was designed and installed to monitor critical points within each sedimentary package. Understanding the vertical VOC distribution and concentrations produced substantial cost savings by minimizing the number of permanent monitoring wells and reducing the number of costly conductor casings to be installed. Significant long-term cost savings will result from reduced sampling costs. Where total VOC concentrations exceeded 20 φg/l in the screening samples, a good correlation was found between the discrete-depth screening data and data from monitoring wells. Using a screening program to characterize the site before installing monitoring wells resulted in an estimated 50-percent reduction in costs for site characterization, 65-percent reduction in time for site characterization, and 50-percent reduction in long-term monitoring costs

  7. Comparisons between vs30 and spectral response for 30 sites in Newcastle, Australia from collocated seismic cone penetrometer, active- and passive-source vs data

    Science.gov (United States)

    Volti, Theodora; Burbidge, David; Collins, Clive; Asten, Michael W.; Odum, Jackson K.; Stephenson, William J.; Pascal, Chris; Holzschuh, Josef

    2016-01-01

    Although the time‐averaged shear‐wave velocity down to 30 m depth (VS30) can be a proxy for estimating earthquake ground‐motion amplification, significant controversy exists about its limitations when used as a single parameter for the prediction of amplification. To examine this question in absence of relevant strong‐motion records, we use a range of different methods to measure the shear‐wave velocity profiles and the resulting theoretical site amplification factors (AFs) for 30 sites in the Newcastle area, Australia, in a series of blind comparison studies. The multimethod approach used here combines past seismic cone penetrometer and spectral analysis of surface‐wave data, with newly acquired horizontal‐to‐vertical spectral ratio, passive‐source surface‐wave spatial autocorrelation (SPAC), refraction microtremor (ReMi), and multichannel analysis of surface‐wave data. The various measurement techniques predicted a range of different AFs. The SPAC and ReMi techniques have the smallest overall deviation from the median AF for the majority of sites. We show that VS30 can be related to spectral response above a period T of 0.5 s but not necessarily with the maximum amplification according to the modeling done based on the measured shear‐wave velocity profiles. Both VS30 and AF values are influenced by the velocity ratio between bedrock and overlying sediments and the presence of surficial thin low‐velocity layers (0.5  s do the amplification curves consistently show higher values for soft site classes and lower for hard classes.

  8. Demonstration of the Air Force Site Characterization and Analysis Penetrometer System (AFSCAPS) at Plattsburgh AFB in Support of Bioventing and Natural Attenuation Initiatives

    National Research Council Canada - National Science Library

    Gildea, Martin

    1993-01-01

    Applied Research Associates, Inc. and Dakota Technologies, Inc. are under contract to develop an improved laser induced fluorescence cone penetrometer tool for the Air Force Site Characterization Analysis Penetrometer System (AFSCAPS...

  9. Soil penetrometers and penetrability

    Science.gov (United States)

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

  10. Procedures for One-Pass Vehicle Cone Index (VCI1) Determination for Acquisition Support

    Science.gov (United States)

    2013-08-01

    and Evolution History behind the VCI Test Procedures ............................ 29  Appendix B: The Cone Penetrometer ...11  Figure 4. Soil equipment. From left to right: trafficability cone penetrometer ...right agreement in CI. ........................................................................ 25  Figure 14. Parts of a cone penetrometer . 1. Handle 2

  11. Feasibility of using cone penetrometer truck (CPT) to install time domain reflectometry (TDR) and fiber optic slope failure detectors in pavement structures.

    Science.gov (United States)

    2011-02-01

    A new method of cable installation using a heavy-duty Cone Penetration Test : (CPT) truck was developed and practiced successfully in this study. The coaxial and fiber : optic cables were pushed along with the cone rods by the hydraulic system integr...

  12. Korelasi Pengujian Kepadatan Lapangan Dan Static Hand Penetrometer Terhadap Hasil Cbr Laboratorium Pada Beberapa Jenis Tanah

    OpenAIRE

    Yusa, Muhamad; Nugroho, S.A

    2008-01-01

    In highway design, it is necessary to check the subgrade bearing capacity since it influences the pavement thickness. There are several methods used to determine the subgrade bearing capacity such as DCP (Dynamic Cone Penetrometer) and HCP (Hand Cone Penetrometer). This research aims to compare between CBR and soil density combined with HCP; to find the initial correlation between HCP and CBR; and to find the correlation between HCP and soil density (yt). The correlation between HCP to soil d...

  13. SITE CHARACTERIZATION ANALYSIS PENETROMETER SYSTEM (SCAPS) - INNOVATIVE TECHNOLOGY EVALUATION REPORT

    Science.gov (United States)

    In August 1994, a demonstration of cone penetrometer-mounted sensor technologies took place to evaluate their effectiveness in sampling and analyzing the physical and chemical characteristics of subsurface sod at hazardous waste sites. he effectiveness of each technology was eval...

  14. Investigation on the Combined Use of Ground Penetrating Radar, Cone Penetrometer and High Resolution Seismic Data for Near Surface and Vadose Zone Characterization in the A/M Area of the Savannah River Site, South Carolina

    International Nuclear Information System (INIS)

    Wyatt, D.E.; Cumbest, R.J.; Aadland, R.K.; Syms, F.H.; Stephenson, D.E.; Sherrill, J.C.

    1997-06-01

    This study compares data from Cone Penetrometer Tests (CPT), high resolution surface reflection seismic (HRS) data and ground penetrating radar (GPR) data in the upper 120 feet (40 meters) of the A/M Area, Upper Three Runs Watershed at the Savannah River Site in South Carolina. The CPT, GPR, and HRS data were obtained along the Silverton Road in the western sector of the A/M Area groundwater plume, and adjacent to Geophysical Correlation Boring number-sign 1 (GCB-1). This location allows for multiple correlations to be made between the various data sources, and supports shallow investigations for near surface affects of the Crackerneck Fault, a major structural feature in the area. Borehole geophysical data from GCB-1 were used to provide subsurface constraints on the CPT, GPR, and HRS data. core data, natural gamma ray, spectral gamma data, multi-level induction resistivity, density and sonic data were utilized to distinguish clays, sands and silts. The CPT data provided tip bearing and sleeve stress, as an indicator of stratigraphy. Reflection seismic data provided continuous subsurface profiles of key marker horizons. Ground Penetrating Radar provided information on shallow subsurface geological features. Conclusions from this study suggest that there is a high degree of correlation between the CPT and borehole geophysical data, specifically, the Friction Ratio and gamma/spectral gamma curves. The Upland/Tobacco Road, Tobacco Road/Dry Branch, Dry Branch/Santee, Santee/Warley Hill and the Warley Hill/Congaree contacts are discernible. From these contacts it is possible to map structural relationships in the shallow subsurface that are tied to regional data. Because formation contacts are discernible, CPT, HRS, GPR, and geophysical log intra-formational anomalies are mappable. These features allow for stratigraphic and facies mapping using the GPR and HRS data for continuity and the CPT and geophysical data for lithofacies analysis. It is possible to use the

  15. Development of a Motorized Digital Cone Penetrometer

    Science.gov (United States)

    Quantification and management of variability in soil strength, or soil compaction, is an important issue in Korea, but tractor mounted on-the-go sensors that have been developed in the USA and European countries are not practical, due to the small size of typical Korean fields. Therefore, hand-opera...

  16. Steerable/distance enhanced penetrometer delivery system

    International Nuclear Information System (INIS)

    Amini, A.; Shenhar, J.; Lum, K.D.

    1995-01-01

    The first steps toward contaminant plume contaminant and remediation are detection and mapping of the plume. Penetrometers can be used to map the plume efficiently and also provide the means for in-situ sampling and remediation. In traditional penetrometer applications, the instrumentation package located at the tip measures soil resistance. However, for environmental monitoring purposes, an array of environmental sensors is packed inside the penetrometer rods for in-situ sampling and analysis, or for collection of laboratory samples. At present, penetrometer applications are limited primarily to vertical pushes and because of their heavy weight, the use of penetrometer trucks over shallow buried storage tanks is restricted. To close the technology gap in the use of penetrometers for environmental purposes, UTD took the initiative by developing a new position location device referred to as POLO (short for POsition LOcator), which provides real-time position location without blocking downhole access for environmental sensors. The next step taken was the initiation of work to make penetrometers steerable and capable of greater penetration capabilities. The product of this work will be a relatively lightweight vibratory steerable penetrometer that can provide greater penetration capability than traditional penetrometers of the same weight, permitting applications over shallow buried storage tanks

  17. Self-recording portable soil penetrometer

    Science.gov (United States)

    Costes, N. C.; Sturm, R. G.; Norton, R. H.; Campbell, G. E. (Inventor)

    1973-01-01

    A lightweight portable penetrometer for testing soil characteristics is described. The penetrometer is composed of a handle, data recording, and probe components detachably joined together. The data recording component has an easily removed recording drum which rotates according to the downward force applied on the handle, and a stylus means for marking the drum along its height according to the penetration depth of probe into the soil.

  18. Estudos com penetrometria: novos equipamentos e amostragem correta Penetrometer studies: new equipaments and correct sampling

    Directory of Open Access Journals (Sweden)

    José P. Molin

    2012-05-01

    Full Text Available RESUMO O indicador mais comumente utilizado para o diagnóstico de compactação do solo é o Índice de Cone (IC, obtido a partir de penetrômetros. No mercado estão disponíveis vários modelos, com diferentes princípios de funcionamento; ressalta-se que a comparabilidade de resultados entre eles precisa ser suficientemente conhecida. Neste trabalho objetivou-se comparar três penetrômetros com princípios diferentes de funcionamento e estabelecer um número ideal de repetições para cada ponto amostrado. Utilizaram-se um penetrômetro de impacto, um penetrômetro de registro eletrônico de dados e de acionamento manual e um de acionamento hidráulico, em três ambientes. De maneira geral, os equipamentos não produziram valores de IC comparáveis em tendências e em magnitude; no entanto não é claro se essas diferenças são relevantes para o diagnóstico de compactação do solo e a partir de 15 repetições o erro amostral dos valores de IC não sofreu decréscimo significativo, variando entre 5 e 15% entre os penetrômetros avaliados.ABSTRACT The most commonly used indicator for soil compaction diagnose is the Cone Index (CI obtained from penetrometers. Several models are available in the market with different operating principles and comparability of results among them is not sufficiently known. This study aimed to compare three cone penetrometers with different operation principles and to establish an optimal number of replications for each sampling point. The equipment used were an impact penetrometer, an electronic penetrometer manually operated and an electronic penetrometer hydraulically operated, in three environments. The equipment, in general, did not produce comparable CI values in magnitude and in tendency. However it is not clear whether these differences are relevant for diagnosis of soil compaction. It is possible yet, to affirm that after 15 replications, the sampling errors of CI values did not decrease significantly

  19. Extendable mast used in one shot soil penetrometer

    Science.gov (United States)

    Hotz, G. M.; Howard, G. A.

    1966-01-01

    Penetrometer to test soil characteristics has a piercing head with soil instrumentation equipment attached to an expandable mast actuated by compressed air. The penetrometer gives continuous measurements as the mast pushes the piercing head through the soil.

  20. Xenon Spectral Gamma Penetrometer Probe Characterization and Calibration

    National Research Council Canada - National Science Library

    Ballard, John

    2004-01-01

    .... A Site Characterization and Analysis Penetrometer System (SCAPS) spectral gamma penetrometer probe was designed using newly developed small-diameter high-pressure xenon gas gamma ray detector technology for the in situ speciation (identification...

  1. Use of a combined penetrometer-TDR moisture probe for soil compaction studies

    International Nuclear Information System (INIS)

    Pedro Vaz, C.M.

    2004-01-01

    Soil mechanical strength is an important soil parameter that affects root growth and water movement, and controls nutrient and contaminant transport below the rooting zone. The most common way to assess soil strength is by using a soil penetrometer, which characterizes the force needed to drive a cone of specific size into the soil. The measured penetration resistance (PR) depends on such soil properties as bulk density, water content and potential, texture, aggregation, cementation and mineralogy. Soil scientists have related changes in PR as caused by tillage, traffic or soil genetic pans to root growth, crop yields and soil physical properties. For example, correlation between PR and crop root growth and water and nutrient exploration have been obtained, and cone penetrometers have been used extensively in soil science studies to identify natural and induced compacted layers or to predict related soil properties. Many studies have been conducted to understand the influence of bulk density and water content on PR in the laboratory and, from which both empirical and theoretical relationships were obtained. From the many different models that have been introduced to test these relationships (polynomial, exponential, power and linear equations), it is suggested that either the power or exponential equations are the most adequate. Using dimensional analysis techniques, it was suggested a power exponential equation for prediction of the PR for a silt loam soil, but also suggested additional experimental work for its validation. However, many referenced studies lack accurate and representative data, because PR is a highly variable soil property, whereas it is usually determined from local small-scale measurements. Hence, difficulties in relating PR with other soil parameters can be attributed mostly to soil spatial variability, because available measurement techniques prevent determination of the different soil attributes at the same spatial location. To improve on the

  2. Use and interpretation of the dynamic cone penetrometer (DCP) test

    CSIR Research Space (South Africa)

    Paige-Green, P

    2009-09-01

    Full Text Available During the early 1930's the California Bearing Ratio test (CBR) was developed for the testing of material strength in the laboratory for the design of pavements. The test involves the compaction of a potential road-building material into a standard...

  3. DEVELOPMENT OF A WALKING-TYPE DIGITAL CONE PENETROMETER

    Science.gov (United States)

    Quantification and management of variability in soil strength, or soil compaction, is an important issue in Korea, but tractor mounted on-the-go sensors that have been developed in the USA and European countries are not practical, due to the small size of typical Korean fields. Therefore, hand-opera...

  4. LASER FLUORESCENCE EEM PROBE FOR CONE PENETROMETER POLLUTION ANALYSIS

    Science.gov (United States)

    A fiber optic LIF (Laser induced fluorescence) EEM (Excitation emission matrix) instrument for CPT deployment has been successfully developed and field tested. The system employs a Nd: YAG laser and Raman shifter as a rugged field portable excitation source. This excitation sou...

  5. Relating mobile sensor soil strength to penetrometer cone index

    Science.gov (United States)

    A horizontally operating on-the-go soil strength profile sensor (SSPS) was previously developed so that the within-field spatial variability in soil strength could be measured at five evenly spaced depths up to 50 cm. Force divided by the base area of the sensing tip of the SSPS was defined as a pri...

  6. Sampling plan for using a motorized penetrometer in soil compaction evaluation

    Directory of Open Access Journals (Sweden)

    Lindolfo Storck

    2016-03-01

    Full Text Available ABSTRACT This study aimed to estimate the size of blocks of observations of resistance to penetration, obtained by a motorized digital penetrometer, and the number of blocks with semi-amplitude of the confidence interval between 5 and 20% of the mean penetration resistance, for different soil depth ranges and cone diameters. Data were collected in two contrasting plots of a crop-livestock integration experiment, located in Abelardo Luz, SC, Brazil. Ten blocks were delimited and the resistance to penetration was determined in 20 points spaced by 20 cm, using a motorized digital soil penetrometer. To estimate the mean of resistance to penetration, 12 blocks of four points per experimental plot should be used for a semi-amplitude of the confidence interval equal to 10% of the mean (1 - p = 0.95. Twenty random points may be sampled to estimate mean of penetration resistance for a semiamplitude confidence interval of 10% of the man (1 - p = 0.95. The sample size for the layer of 0-10 cm is larger than in the deeper layers (0-20, 0-30 and 0-40 cm and smaller for cones with larger diameter.

  7. The AFL penetrometer study: work in progress.

    Science.gov (United States)

    Orchard, J

    2001-06-01

    Five hundred and seventy one matches in the Australian Football League [AFL] had ground hardness measured using a Penetrometer, over the period 1997-2000. The method used was 3 drops at each of 20 locations over the playing field on the morning before games. Anterior Cruciate Ligament [ACL] injuries were recorded using an ongoing injury surveillance system. There was a non-significant trend towards a higher risk of ACL injury when the 3-drop average of the Penetrometer was less (harder) than 4.5cm, RR 2.36 (95% CI 0.90-6.24). When the first drop average of the Penetrometer was less (harder) than 2.5cm, the relative risk was 2.60 (95% CI 0.94-7.20). There was also a nonsignificant trend towards an increased risk of ACL injury in games where the predominant grass type was couch (Bermuda) grass, as opposed to rye grass, RR 2.37 (95% CI 0.89-6.36). This study confirms previous findings from the AFL that early season matches and matches played at northern (warmer) venues have a higher risk of ACL injury. It is likely that ground-related variables are partially responsible for these observations, but to date, the relative contributions of ground hardness, grass type, shoe-surface traction and other confounding factors are not certain. There was a significant fall in the number of ACL injuries in the AFL (to approximately half the previous level of incidence) during seasons 1999 and 2000. It is possible that reaction to this study and related publicity has led to the preparation of ground conditions in the AFL that are less likely to produce ACL injuries.

  8. Semi-Empirical Method Interpretation of Cone Penetration Test (CPT ...

    African Journals Online (AJOL)

    The soil parameters can be obtained directly from the charts if the value of the tip resistance are known. The approach is suitable because of the insensitivity of the mechanical cone penetrometer in measuring skin friction, especially in clay deposits. Discovery and Innovation Vol. 13 no. 3/4 December (2001) pp. 213-226

  9. A steerable/distance enhanced penetrometer delivery system: Phase II. Topical report

    International Nuclear Information System (INIS)

    Amini, A.; Shenhar, J.; Lum, K.D.

    1996-05-01

    This report summarizes the phase II work on the Position Location Device (POLO) for penetrometers. Phase II was carried out to generate an integrated design of a full-scale steerable/distance enhanced penetrometer delivery system. Steering provides for the controlled and directional use of the penetrometer, while vibratory thrusting can provide greater penetration ability

  10. Investigation of Sediment Strength Characteristics in Approaches to Boston Harbor Using STING Penetrometer

    Science.gov (United States)

    2014-09-17

    Boston Harbor Using STING Penetrometer September 17, 2014 Approved for public release; distribution is unlimited. Andrei Abelev Marine Physics Branch...Investigation of Sediment Strength Characteristics in Approaches to Boston Harbor Using STING Penetrometer Andrei Abelev Naval Research Laboratory...1107 This report discusses results of two series of STING penetrometer measurements of seafloor sediment strength in areas of Boston Harbor approach

  11. Astronaut Edgar Mitchell carries penetrometer attached to handle during EVA

    Science.gov (United States)

    1971-01-01

    Astronaut Edgar D. Mitchell, lunar module pilot, carries the penetrometer attached to an extension handle during extravehicular activity on the lunar surface. The geophone alignment flag is attached to the penetrometer. Several components of the Apollo Lunar Surface Experiments Package (ALSEP) are in the background. The shadow of Astronaut Alan B. Shepard Jr., commander, who took this photograph, is in the foreground, near several prints made by lunar overshoes of the two astronauts and a long track made by a wheel of the Modularized Equipment Transporter (MET).

  12. Cone biopsy

    Science.gov (United States)

    ... biopsy; HSIL - cone biopsy; Low-grade cone biopsy; High-grade cone biopsy; Carcinoma in situ-cone biopsy; ... the cervix. In: Baggish MS, Karram MM, eds. Atlas of Pelvic Anatomy and Gynecologic Surgery . 4th ed. ...

  13. Penetrógrafo eletrônico automático Automatic electronic recording penetrometer

    Directory of Open Access Journals (Sweden)

    Aloísio Bianchini

    2002-01-01

    Full Text Available O presente trabalho relata o desenvolvimento de um penetrógrafo, construído para operar de forma automática, executando um ensaio de penetração com um simples toque no botão de partida. Ele possui incorporado, um sistema dedicado de aquisição de dados, que pode armazenar até 187 ensaios e uma interface de comunicação, dispensando a conexão ao microcomputador ou "datalogger". As condições do ensaio como, por exemplo, data, localização (latitude e longitude e profundidade, podem ser atualizadas, assim como a aferição da célula de carga, via teclado com mostrador de duas linhas. Verificou-se variação de velocidade This paper presents the development of an automatic recording penetrometer, which operates at the touch of a button. It incorporates a data acquisition system, which can store data of 187 tests and has a serial PC interface. The test characterization such as dates, location (latitude and longitude can be recorded as well. The maximum working depth may be set and the load cell calibration can be verified through a keyboard with 2 lines display. A speed variation error of < 5% compared to ASAE standard was verified for cone indices between 500 and 5,684 kPa. The equipment is compact, easy to handle and can realize one test every minute.

  14. Desenvolvimento de um penetrômetro manual eletrônico = Development of an electronic manual penetrometer

    Directory of Open Access Journals (Sweden)

    Rafael Cesar Tieppo

    2011-01-01

    Full Text Available O excesso de tráfego de máquinas pode causar compactação prejudicial ao desenvolvimento da cultura. Uma das maneiras de se obter um indicativo de compactação é a resistência do solo à penetração (RSP. Assim, desenvolveu-se um penetrômetro eletrônico, seguindo a norma S313.2 ASAE (1998, tendo a haste 0,0095 m de diâmetro e o cone de 30° com 0,01283 m de diâmetro na base. Para o desenvolvimento do penetrômetro, utilizou-se um sistema para aquisição de dados, sensor de distância, sensor de força e barras circulares de aço inox para confecção da haste e do cone. O aparelho armazena os dados coletados a campo em uma frequência de 4 Hz, sendo estes posteriormente transferidos para um microcomputador, via interface RS232. Por meio de uma planilha eletrônica, os dados podem ser processados de acordo com a necessidade do usuário. Os sensores apresentaram confiabilidade em sua utilização, os arquivos de dados gerados pelo aparelhoproporcionaram conforto e confiança no processamento de dados e os dados puderam ser reorganizados conforme a necessidade do usuário para, assim, evitar o erro de leitura pelo processo visual.Excess machine traffic can cause compaction that is harmful for crop growth. One way to obtain evidence of soil compaction is to check the mechanical resistance of soil. Thus, an electronic penetrometer was developed according to ASAE (1998 Standard S313.2, featuring a 9.53mm wide diving shaft and a 30° circular stainless steel cone with a 12.83 mm base diameter. The penetrometer was outfitted with a data acquisition system, distance and force sensors, and stainless steel circular bars to construct the diving shaft and cone. The device stores field data collected at a frequency of 4 Hz, which are later transferred onto a microcomputer via a RS232 interface. The collected data can be processed using an electronic spreadsheet according to user needs. The sensors proved reliable during use, and the data files

  15. Effect of microbial activity on penetrometer resistance and elastic modulus of soil at different temperatures.

    Science.gov (United States)

    Gao, W; Muñoz-Romero, V; Ren, T; Ashton, R W; Morin, M; Clark, I M; Powlson, D S; Whalley, W R

    2017-07-01

    We explore the effect of microbial activity stimulated by root exudates on the penetrometer resistance of soil and its elastic modulus. This is important because it is a measure of the mechanical strength of soil and it correlates closely with the rate of elongation of roots. A sandy soil was incubated with a synthetic root exudate at different temperatures, for different lengths of time and with selective suppression of either fungi or bacteria. The shape of the temperature response of penetrometer resistance in soil incubated with synthetic exudate was typical of a poikilothermic temperature response. Both penetrometer resistance and small strain shear modulus had maximum values between 25 and 30°C. At temperatures of 20°C and less, there was little effect of incubation with synthetic root exudate on the small strain shear modulus, although penetrometer resistance did increase with temperature over this range (4-20°C). This suggests that in this temperature range the increase in penetrometer resistance was related to a greater resistance to plastic deformation. At higher temperatures (> 25°C) penetrometer resistance decreased. Analysis of the DNA sequence data showed that at 25°C the number of Streptomyces (Gram-positive bacteria) increased, but selective suppression of either fungi or bacteria suggested that fungi have the greater role with respect to penetrometer resistance. Effect of microbial activity stimulated by synthetic root exudates on the mechanical properties.We compared penetrometer measurements and estimates of elastic modulus with microbial community.Penetrometer resistance of soil showed a poikilothermic temperature response.Penetrometer resistance might be affected more by fungi than bacteria.

  16. Optimum design of sustainable sealed low volume roads using the Dynamic Cone Penetrometer (DCP)

    CSIR Research Space (South Africa)

    Paige-Green, P

    2012-09-01

    Full Text Available significant degree of subgrade compaction, localised weak areas tend to become strengthened and an accumulation of residual gravel wearing course provides a sound support or foundation for the new road. Optimising the use of these conditions usually results...

  17. Applying the dynamic cone penetrometer (DCP) design method to low volume roads

    CSIR Research Space (South Africa)

    Paige-Green, P

    2011-07-01

    Full Text Available . Short periods of heavy traffic also have a disproportionate influence on the overall traffic of low volume roads. As the traffic estimate will directly influence the pavement design, this should be done as carefully as possible, taking into account... uniform section should be carried out. 2.3.2. Moisture conditions The moisture conditions at the time of the DCP survey need to be carefully estimated as discussed in Section 1.1. As the moisture content at the time of testing determines the in situ...

  18. Evaluation of Cone Penetrometer Testing (CPT) for Use with Transportation Projects Phase 1

    Science.gov (United States)

    2008-07-01

    The ODOT Office of Geotechnical Engineering (OGE) currently uses conventional drilling methods (e.g., hollow stem auger, solid stem auger) to perform subsurface investigations in unconsolidated materials. These techniques have been used for decades a...

  19. Cone penetrometer equipped with piezoelectric sensors for measurement of soil stiffness in highway pavement.

    Science.gov (United States)

    2005-11-01

    The stiffness (elastic modulus and shear modulus) and Poisson's ratio of the base and sublayers are important parameters in the design and quality assurance during construction of highway pavements. The new highway construction guide proposed by AASH...

  20. Implantation of Louisiana Electric Cone Penetrometer System (LECOPS) for design of transportation facilities : executive summary.

    Science.gov (United States)

    1994-03-01

    For several decades, the Louisiana Department of Transportation and Development (LDOTD) has been able to rely on an ample supply of labor with appropriate equipment to provide soil design data. Budget cutbacks have forced reduction in personnel and e...

  1. Tri-Service Site Characterization and Analysis Penetrometer System (SCAPS) Validation of the Hydrosparge Volatile Organic Compound Sensor

    National Research Council Canada - National Science Library

    Davis, William

    2001-01-01

    Site characterization for subsurface contaminants is time consuming and costly. The Hydrosparge VOC sensor was developed for the Tri-Services Site characterization and Analysis Penetrometer System (SCAPS...

  2. Genetic architecture of rind penetrometer resistance in two maize recombinant inbred line populations.

    Science.gov (United States)

    Li, Kun; Yan, Jianbing; Li, Jiansheng; Yang, Xiaohong

    2014-06-03

    Maize (Zea Mays L.) is one of the most important cereal crops worldwide and provides food for billions of people. Stalk lodging can greatly undermine the standability of maize plants and therefore decrease crop yields. Rind penetrometer resistance is an effective and reliable method for evaluating maize stalk strength, which is highly correlated with stalk lodging resistance. In this study, two recombinant inbred line populations were constructed from crosses between the H127R and Chang7-2 lines, and between the B73 and By804 lines. We genotyped these two populations and their parents using 3,072 single nucleotide polymorphism markers and performed phenotypic assessment of rind penetrometer resistance in multiple environments to dissect the genetic architecture of rind penetrometer resistance in maize. Based on two linkage maps of 1,397.1 and 1,600.4 cM with average interval of 1.7 and 2.1 cM between adjacent makers, respectively, seven quantitative trait loci (QTL) for rind penetrometer resistance were detected in the two recombinant inbred line populations. These QTL were distributed in seven genomic regions, and each accounted for 4.4-18.9% of the rind penetrometer resistance variation. The QTL with the largest effect on rind penetrometer resistance, qRPR3-1, was located on chromosome 3 with the flanking markers PZE-103123325 and SYN23245. This locus was further narrowed down to a 3.1-Mb interval by haplotype analysis using high-density markers in the target region. Within this interval, four genes associated with the biosynthesis of cell wall components were considered as potential candidate genes for the rind penetrometer resistance effect. The inheritance of rind penetrometer resistance is rather complex. A few large-effect quantitative trait loci, together with a several minor-effect QTL, contributed to the phenotypic variation in rind penetrometer resistance in the two recombinant inbred line populations that were examined. A potential approach for

  3. Cone Algorithm of Spinning Vehicles under Dynamic Coning Environment

    Directory of Open Access Journals (Sweden)

    Shuang-biao Zhang

    2015-01-01

    Full Text Available Due to the fact that attitude error of vehicles has an intense trend of divergence when vehicles undergo worsening coning environment, in this paper, the model of dynamic coning environment is derived firstly. Then, through investigation of the effect on Euler attitude algorithm for the equivalency of traditional attitude algorithm, it is found that attitude error is actually the roll angle error including drifting error and oscillating error, which is induced directly by dynamic coning environment and further affects the pitch angle and yaw angle through transferring. Based on definition of the cone frame and cone attitude, a cone algorithm is proposed by rotation relationship to calculate cone attitude, and the relationship between cone attitude and Euler attitude of spinning vehicle is established. Through numerical simulations with different conditions of dynamic coning environment, it is shown that the induced error of Euler attitude fluctuates by the variation of precession and nutation, especially by that of nutation, and the oscillating frequency of roll angle error is twice that of pitch angle error and yaw angle error. In addition, the rotation angle is more competent to describe the spinning process of vehicles under coning environment than Euler angle gamma, and the real pitch angle and yaw angle are calculated finally.

  4. Portable penetrometer for agricultural soil: sensitivity test to identify critical compaction depth

    Directory of Open Access Journals (Sweden)

    João Carlos Medeiros

    2010-12-01

    Full Text Available To express the negative effects of soil compaction, some researchers use critical values for soil mechanical strength that severely impair plant growth. The aim of this study was to identify this critical compaction depth, to test the functionality of a new, portable penetrometer developed from a spring dynamometer, and compare it to an electronic penetrometer traditionally used in compaction studies of agricultural soils. Three soils with distinct texture were conventionally tilled using a disk plow, and cultivated with different plant species. The critical soil resistance defined to establish critical compaction depth was equal to 1.5 MPa. The results of the new equipment were similar to the electronic penetrometer, indicating its viability as a tool for assessing the soil physical conditions for plant growth.

  5. PREDIKSI KADAR PATI UBI KAYU (Manihot esculenta PADA BERBAGAI UMUR PANEN MENGGUNAKAN PENETROMETER

    Directory of Open Access Journals (Sweden)

    Siti Nurdjanah

    2012-12-01

    Full Text Available Over the years, determination of starch content by the buyers on the field is performed based on the difference between cassava’s weight on the air and that of in the water, then counted based on the formula designed by International Starch Institute (ISI. This method has been proven to be highly correlated with the starch content determined chemically such as acid hydrolysis. However, this method is less practical due to the need of a large amount of water which is rarely found on cassava plantation. The aims of this study were : 1 to find alternative way to measure cassava’s starch content on the field using penetrometer, 2 to find correlation between starch content measurement using penetrometer and weighing method as described by ISI; correlation between hardness measured using penetrometer and acid hydrolysis. The experiment was arranged as a single treatment harvesting period consisted of 7, 8, 9 and 10 month in a complete randomized  design  with three replications. Data were analyzed using linier regression to find correlation between hardness and starch content analyzed using acid hydrolysis ; correlation between starch yield and starch content analyzed using acid hydrolysis; correlation of starch content analyzed using acid hydrolysis and that of using ISI method. The result shows that there is a high positive correlation between cassava’s hardness using penetrometer and cassava’s starch content using acid hydrolysis method. This implies that penetrometer is a potential tool for predicting cassava’s starch content. Keywords : cassava, penetrometer, hardness, starch content

  6. Field studies of beach cones as coastal erosion control/reversal devices for areas with significant oil and gas activities. Final report, February 24, 1992--September 18, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Law, V.J.

    1995-09-18

    The primary objective of this project was to evaluate the utility of a device called the {open_quotes}beach cone{close_quotes} in combating coastal erosion. Seven initial sites were selected for testing beach cones in a variety of geometric configurations. Permits were obtained from the State of Louisiana and the U.S. Army Corps of Engineers to perform the work associated with this study. Six hundred beach cones were actually installed at six of the sites in late July and early August, 1992. Findings indicate that beach cones accreted significant amounts of materials along the beach of a barrier island, and they might have been instrumental in repairing an approximately 200 meter gap in the island. At the eighth installation the amount of accreted material was measured by surveys to be 2200 cubic meters (2900 cubic yards) in February of 1993, when the cones were found to have been completely covered by the material. At other test sites, accretion rates have been less dramatic but importantly, no significant additional erosion has occurred, which is a positive result. The cost of sediment accretion using beach cones was found to be about $13.72 per cubic yard, which would be much lower if the cones were mass produced (on the order of $3.00 per cubic yard). The survival of the cones through the fringes of Hurricane Andrew indicates that they can be anchored sufficiently to survive significant storms. The measurements of the cones settling rates indicate that this effect is not significant enough to hinder their effectiveness. A subcontract to Xavier University to assess the ecological quality of the experimental sites involved the study of the biogeochemical cycle of trace metals. The highest concentration of heavy metals were near a fishing camp while the lowest levels were in the beach sand of a barrier island. This suggests that the metals do not occur naturally in these areas, but have been placed in the sediments by man`s activities.

  7. Statistical analysis of cone penetration resistance of railway ballast

    Science.gov (United States)

    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.

  8. Statistical analysis of cone penetration resistance of railway ballast

    Directory of Open Access Journals (Sweden)

    Saussine Gilles

    2017-01-01

    Full Text Available 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.

  9. Cost and Performance Report for the Tri-Service Site Characterization and Analysis Penetrometer System (SCAPS) Hydrosparge Volatile Organic Compound Sensor

    National Research Council Canada - National Science Library

    Costanza, Jed

    2001-01-01

    Site characterization for subsurface contaminants is time consuming and costly. The Hydrosparge VOC sensor was developed for the Tri-Services Site characterization and Analysis Penetrometer System (SCAPS...

  10. Estimation of the density state of anthropogenic soils using a dynamic heavy penetrometer (DPH

    Directory of Open Access Journals (Sweden)

    Czaczkowski Wojciech

    2015-09-01

    Full Text Available The loading of natural and anthropogenic soils can be determined in the field by using dynamic probing tests. This method is based on the measurement of the resistance, which the studied soil poses on the probe tip when it penetrates the soil. The most typical probe tips are cylindrical, conical and rarely cross-shaped. The penetrometer penetrates the soil by a hammer with a given mass freely falling from the height required in the test. The penetration resistance is defined by the numbers of blows required to drive the penetrometer over the defined distance (Nk, where k = 10, 15(20 or 30 cm. The paper presents the results of heavy dynamic probing tests DPH with a hammer mass of 50 kg and penetration depth up to 30 m, carried out in an anthropogenic made ground in order to determine the soil loading for the foundation of the designed building.

  11. Alternative Penetrometers to Measure the Near Surface Strength of Soft Seafloor Soils

    Science.gov (United States)

    2013-09-30

    specimens has been a key accomplishment for this project. The readied specimens were tested by advancing a standard ball penetrometer (100 cm2), mini ...simple shear testing. Digital imaging was used to observe the flow mechanism during shallow penetration. A photo of the soil flow mechanisms for the mini ...tested at a rock quarry site in Irwindale. Soft and fine grained tailings were tested in an old spreading pond at the site. A total of six spherical

  12. Effect of microbial activity on penetrometer resistance and elastic modulus of soil at different temperatures

    OpenAIRE

    Gao, W.; Mu?oz?Romero, V.; Ren, T.; Ashton, R. W.; Morin, M.; Clark, I. M.; Powlson, D. S.; Whalley, W. R.

    2017-01-01

    Summary We explore the effect of microbial activity stimulated by root exudates on the penetrometer resistance of soil and its elastic modulus. This is important because it is a measure of the mechanical strength of soil and it correlates closely with the rate of elongation of roots. A sandy soil was incubated with a synthetic root exudate at different temperatures, for different lengths of time and with selective suppression of either fungi or bacteria. The shape of the temperature response ...

  13. Strength Measurements of Archive K Basin Sludge Using a Soil Penetrometer

    Energy Technology Data Exchange (ETDEWEB)

    Delegard, Calvin H.; Schmidt, Andrew J.; Chenault, Jeffrey W.

    2011-12-06

    Spent fuel radioactive sludge present in the K East and K West spent nuclear fuel storage basins now resides in the KW Basin in six large underwater engineered containers. The sludge will be dispositioned in two phases under the Sludge Treatment Project: (1) hydraulic retrieval into sludge transport and storage containers (STSCs) and transport to interim storage in Central Plateau and (2) retrieval from the STSCs, treatment, and packaging for shipment to the Waste Isolation Pilot Plant. In the years the STSCs are stored, sludge strength is expected to increase through chemical reaction, intergrowth of sludge crystals, and compaction and dewatering by settling. Increased sludge strength can impact the type and operation of the retrieval equipment needed prior to final sludge treatment and packaging. It is important to determine whether water jetting, planned for sludge retrieval from STSCs, will be effective. Shear strength is a property known to correlate with the effectiveness of water jetting. Accordingly, the unconfined compressive strengths (UCS) of archive K Basin sludge samples and sludge blends were measured using a pocket penetrometer modified for hot cell use. Based on known correlations, UCS values can be converted to shear strengths. Twenty-six sludge samples, stored in hot cells for a number of years since last being disturbed, were identified as potential candidates for UCS measurement and valid UCS measurements were made for twelve, each of which was found as moist or water-immersed solids at least 1/2-inch deep. Ten of the twelve samples were relatively weak, having consistencies described as 'very soft' to 'soft'. Two of the twelve samples, KE Pit and KC-4 P250, were strong with 'very stiff' and 'stiff' consistencies described, respectively, as 'can be indented by a thumb nail' or 'can be indented by thumb'. Both of these sludge samples are composites collected from KE Basin floor and

  14. Design of a horizontal penetrometer for measuring on-the-go soil resistance.

    Science.gov (United States)

    Topakci, Mehmet; Unal, Ilker; Canakci, Murad; Celik, Huseyin Kursat; Karayel, Davut

    2010-01-01

    Soil compaction is one of the main negative factors that limits plant growth and crop yield. Therefore, it is important to determine the soil resistance level and map it for the field to find solutions for the negative effects of the compaction. Nowadays, high powered communication technology and computers help us on this issue within the approach of precision agriculture applications. This study is focused on the design of a penetrometer, which can make instantaneous soil resistance measurements in the soil horizontally and data acquisition software based on the GPS (Global Positioning System). The penetrometer was designed using commercial 3D parametric solid modelling design software. The data acquisition software was developed in Microsoft Visual Basic.NET programming language. After the design of the system, manufacturing and assembly of the system was completed and then a field experiment was carried out. According to the data from GPS and penetration resistance values which are collected in Microsoft SQL Server database, a Kriging method by ArcGIS was used and soil resistance was mapped in the field for a soil depth of 40 cm. During operation, no faults, either in mechanical and software parts, were seen. As a result, soil resistance values of 0.2 MPa and 3 MPa were obtained as minimum and maximum values, respectively. In conclusion, the experimental results showed that the designed system works quite well in the field and the horizontal penetrometer is a practical tool for providing on-line soil resistance measurements. This study contributes to further research for the development of on-line soil resistance measurements and mapping within the precision agriculture applications.

  15. Design of a Horizontal Penetrometer for Measuring On‑the‑Go Soil Resistance

    Directory of Open Access Journals (Sweden)

    Davut Karayel

    2010-10-01

    Full Text Available Soil compaction is one of the main negative factors that limits plant growth and crop yield. Therefore, it is important to determine the soil resistance level and map it for the field to find solutions for the negative effects of the compaction. Nowadays, high powered communication technology and computers help us on this issue within the approach of precision agriculture applications. This study is focused on the design of a penetrometer, which can make instantaneous soil resistance measurements in the soil horizontally and data acquisition software based on the GPS (Global Positioning System. The penetrometer was designed using commercial 3D parametric solid modelling design software. The data acquisition software was developed in Microsoft Visual Basic.NET programming language. After the design of the system, manufacturing and assembly of the system was completed and then a field experiment was carried out. According to the data from GPS and penetration resistance values which are collected in Microsoft SQL Server database, a Kriging method by ArcGIS was used and soil resistance was mapped in the field for a soil depth of 40 cm. During operation, no faults, either in mechanical and software parts, were seen. As a result, soil resistance values of 0.2 MPa and 3 MPa were obtained as minimum and maximum values, respectively. In conclusion, the experimental results showed that the designed system works quite well in the field and the horizontal penetrometer is a practical tool for providing on‑line soil resistance measurements. This study contributes to further research for the development of on-line soil resistance measurements and mapping within the precision agriculture applications.

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

    NARCIS (Netherlands)

    Fleischer, M; van Ree, C.C.D.F.; Leven, C

    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

  17. Cone penetrometer equipped with piezoelectric sensors for measurement of soil stiffness in highway pavement : executive summary report.

    Science.gov (United States)

    2005-11-01

    The stiffness (elastic modulus and shear modulus) and Poissons ratio of the base and : sublayers are important parameters in the design and quality assurance during construction of : highway pavements. During and after the construction of a paveme...

  18. Compared performance of penetrometers and effect of soil water content on penetration resistance measurements

    Directory of Open Access Journals (Sweden)

    Edison Aparecido Mome Filho

    2014-06-01

    Full Text Available Modern agriculture techniques have a great impact on crops and soil quality, especially by the increased machinery traffic and weight. Several devices have been developed for determining soil properties in the field, aimed at managing compacted areas. Penetrometry is a widely used technique; however, there are several types of penetrometers, which have different action modes that can affect the soil resistance measurement. The objective of this study was to compare the functionality of two penetrometry methods (manual and automated mode in the field identification of compacted, highly mechanized sugarcane areas, considering the influence of soil water volumetric content (θ on soil penetration resistance (PR. Three sugarcane fields on a Rhodic Eutrudrox were chosen, under a sequence of harvest systems: one manual harvest (1ManH, one mechanized harvest (1MH and three mechanized harvests (3MH. The different degrees of mechanization were associated to cumulative compaction processes. An electronic penetrometer was used on PR measurements, so that the rod was introduced into the soil by hand (Manual and by an electromechanical motor (Auto. The θ was measured in the field with a soil moisture sensor. Results showed an effect of θ on PR measurements and that regression models must be used to correct data before comparing harvesting systems. The rod introduction modes resulted in different mean PR values, where the "Manual" overestimated PR compared to the "Auto" mode at low θ.

  19. Curing depth of (polyacid-modified) composite resins determined by scraping and a penetrometer.

    Science.gov (United States)

    Koupis, Nikolaos S; Vercruysse, Chris W J; Marks, Luc A M; Martens, Luc C; Verbeeck, Ronald M H

    2004-12-01

    The present study aimed to compare the curing depth of polyacid-modified composite resins (PAM-C) and some representative composite resins as a function of shade and post-cure using a scraping method and a penetrometer. The curing depth of the PAM-C Hytac, F2000, Glasiosite, Dyract, Dyract AP, and Compoglass F and of the composite resins Durafill VS and Z100 were determined for shade A2 and A4 using a scraping method based on ISO 4049:2000 and a digital penetrometer. Samples were light-cured (800 mW/cm2 at 40 s) in bulk in split stainless steel molds. Immediately after light-curing or after a 24 h post-cure, the height of the cylinder of cured material was measured and taken as the curing depth. For both test methods, the curing depth was independent of post-cure (P > or = 0.05) but differed significantly among materials and shade (Ppenetrometer give comparable curing depths for PAM-C. The curing depth greatly varies among the materials and can be considerably smaller than that of a microfilled composite resin. Shade A2 results in significantly greater values for the curing depth compared to shade A4, the effect depending quantitatively on the formulation of the material.

  20. Quotient normed cones

    Indian Academy of Sciences (India)

    general setting of the space CL(X, Y ) of all continuous linear mappings from a normed cone (X, p) to a normed cone (Y, q), extending several well-known results related to open continuous linear mappings between normed linear spaces. Keywords. Normed cone; extended quasi-metric; continuous linear mapping; bicom-.

  1. Long term effect of higher soil penetrometer resistance in cow congregation zone: Implication on soils and forage quality

    Science.gov (United States)

    Higher degree of soil penetrometer resistance (SPR) can reduce crop yields and can lead to water and soil quality degradation due to increased runoff and soil structure destruction. The effect of trampling appears to be less severe on vegetated grasslands than on poor or bare soil. Understanding cat...

  2. Light-cone superspace BPS theory

    Science.gov (United States)

    Hearin, Patrick

    2011-05-01

    The BPS bound is formulated in light-cone superspace for the N=4 super-Yang-Mills theory. As a consequence of the superalgebra all momenta are shown to be expressed as a quadratic form in the relevant supertransformations, and these forms are used to derive the light-cone superspace BPS equations. Finally, the superfield expressions are expanded out to component form, and the Wu-Yang monopole boosted to the infinite momentum frame is shown to be a solution.

  3. Bornological Locally Convex Cones

    Directory of Open Access Journals (Sweden)

    Davood Ayaseh

    2014-10-01

    Full Text Available In this paper we define bornological and b-bornological cones and investigate their properties. We give some characterization for these cones. In the special case of locally convex topological vector space both these concepts reduce to the known concept  of bornological spaces. We introduce and investigate the  convex quasiuniform   structures U_{tau}, U_{sigma}(P,P* and \\U_{beta}(P,P* on locally convex cone (P,U.

  4. Chain on a cone

    Directory of Open Access Journals (Sweden)

    Zubelevich Oleg

    2017-11-01

    Full Text Available We consider a loop of a chain thrown like a lasso on a fixed right circular cone. The system is in the standard homogeneous gravity field. The axis of the cone is vertical. It is shown that under certain vertex angles chain’s loop has an oblique equilibrium.

  5. Spatial variability of detrended soil plow layer penetrometer resistance transect in a sugarcane field

    Science.gov (United States)

    Pérez, Luis D.; Cumbrera, Ramiro; Mato, Juan; Millán, Humberto; Tarquis, Ana M.

    2015-04-01

    Spatial variability of soil properties is relevant for identifying those zones with physical degradation. In this sense, one has to face the problem of identifying the origin and distribution of spatial variability patterns (Brouder et al., 2001; Millán et al., 2012). The objective of the present work was to quantify the spatial structure of soil penetrometer resistance (PR) collected from a transect data consisted of 221 points equidistant. In each sampling, readings were obtained from 0 cm till 70 cm of depth, with an interval of 5 cm (Pérez, 2012). The study was conducted on a Vertisol (Typic Hapludert) dedicated to sugarcane (Saccharum officinarum L.) production during the last sixty years (Pérez et al., 2010). Recently, scaling approach has been applied on the determination of the scaling data properties (Tarquis et al., 2008; Millán et al., 2012; Pérez, 2012). We focus in the Hurst analysis to characterize the data variability for each depth. Previously a detrended analysis was conducted in order to better study de intrinsic variability of the series. The Hurst exponent (H) for each depth was estimated showing a characteristic pattern and differentiating PR evolution in depth. References Brouder, S., Hofmann, B., Reetz, H.F., 2001. Evaluating spatial variability of soil parameters for input management. Better Crops 85, 8-11. Millán, H; AM Tarquís, Luís D. Pérez, Juan Mato, Mario González-Posada, 2012. Spatial variability patterns of some Vertisol properties at a field scale using standardized data. Soil and Tillage Research, 120, 76-84. Pérez, Luís D. 2012. Influencia de la maquinaria agrícola sobre la variabilidad espacial de la compactación del suelo. Aplicación de la metodología geoestadística-fractal. PhD thesis, UPM (In Spanish). Pérez, Luís D., Humberto Millán, Mario González-Posada 2010. Spatial complexity of soil plow layer penetrometer resistance as influenced by sugarcane harvesting: A prefractal approach. Soil and Tillage

  6. Vredefort shatter cones revisited

    Science.gov (United States)

    Nicolaysen, L. O.; Reimold, W. U.

    1999-03-01

    Shatter cones have been described from a number of circular and polygonal structures worldwide, the origin of which has been alternatively ascribed to the impacts of large extraterrestrial projectiles or to catastrophic endogenic processes. Despite their association with enigmatic, catastrophic processes, the nature of shatter cones and the physics involved in their formation have not been comprehensively researched. Results of detailed field and laboratory studies of shatter cones from three areas in the collar of the Vredefort Dome in South Africa are presented. Vredefort shatter cones are directly related to a widely displayed fracture phenomenon, termed ``multiply striated joint sets (MSJS)''. MSJs are planar to curviplanar fractures occuring at spacings of shock event that affected horizontal strata.

  7. Quotient normed cones

    Indian Academy of Sciences (India)

    E-mail: o.valero@uib.es. MS received 16 December 2005. Abstract. Given a normed cone (X, p) and a subcone Y, we construct and study the quotient normed cone (X/Y, ˜p) generated by Y. In particular we characterize the bicompleteness of (X/Y, ˜p) in terms of the bicompleteness of (X, p), and prove that the dual quotient ...

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

    Science.gov (United States)

    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

  9. Causes and consequences of inherited cone disorders

    NARCIS (Netherlands)

    Roosing, S.; Thiadens, A.A.H.J.; Hoyng, C.B.; Klaver, C.C.; Hollander, A.I. den; Cremers, F.P.M.

    2014-01-01

    Hereditary cone disorders (CDs) are characterized by defects of the cone photoreceptors or retinal pigment epithelium underlying the macula, and include achromatopsia (ACHM), cone dystrophy (COD), cone-rod dystrophy (CRD), color vision impairment, Stargardt disease (STGD) and other maculopathies.

  10. Advances in Valveless Piezoelectric Pump with Cone-shaped Tubes

    Science.gov (United States)

    Zhang, Jian-Hui; Wang, Ying; Huang, Jun

    2017-07-01

    This paper reviews the development of valveless piezoelectric pump with cone-shaped tube chronologically, which have widely potential application in biomedicine and micro-electro-mechanical systems because of its novel principles and deduces the research direction in the future. Firstly, the history of valveless piezoelectric pumps with cone-shaped tubes is reviewed and these pumps are classified into the following types: single pump with solid structure or plane structure, and combined pump with parallel structure or series structure. Furthermore, the function of each type of cone-shaped tubes and pump structures are analyzed, and new directions of potential expansion of valveless piezoelectric pumps with cone-shaped tubes are summarized and deduced. The historical argument, which is provided by the literatures, that for a valveless piezoelectric pump with cone-shaped tubes, cone angle determines the flow resistance and the flow resistance determines the flow direction. The argument is discussed in the reviewed pumps one by one, and proved to be convincing. Finally, it is deduced that bionics is pivotal in the development of valveless piezoelectric pump with cone-shaped tubes from the perspective of evolution of biological structure. This paper summarizes the current valveless piezoelectric pumps with cone-shaped tubes and points out the future development, which may provide guidance for the research of piezoelectric actuators.

  11. Developing a Penetrometer-Based Mapping System for Visualizing Silage Bulk Density from the Bunker Silo Face

    Directory of Open Access Journals (Sweden)

    Menghua Li

    2016-07-01

    Full Text Available For silage production, high bulk density (BD is critical to minimize aerobic deterioration facilitated by oxygen intrusion. To precisely assess packing quality for bunker silos, there is a desire to visualize the BD distribution within the silage. In this study, a penetrometer-based mapping system was developed. The data processing included filtering of the penetration friction component (PFC out of the penetration resistance (PR, transfer of the corrected penetration resistance (PRc to BD, incorporation of Kriged interpolation for data expansion and map generation. The experiment was conducted in a maize bunker silo (width: 8 m, middle height: 3 m. The BD distributions near the bunker silo face were represented using two map groups, one related to horizontal- and the other to vertical-density distribution patterns. We also presented a comparison between the map-based BD results and core sampling data. Agreement between the two measurement approaches (RMSE = 19.175 kg·m−3 demonstrates that the developed penetrometer mapping system may be beneficial for rapid assessment of aerobic deterioration potential in bunker silos.

  12. Developing a Penetrometer-Based Mapping System for Visualizing Silage Bulk Density from the Bunker Silo Face.

    Science.gov (United States)

    Li, Menghua; Jungbluth, Kerstin H; Sun, Yurui; Cheng, Qiang; Maack, Christian; Buescher, Wolfgang; Lin, Jianhui; Zhou, Haiyang; Wang, Zhongyi

    2016-07-05

    For silage production, high bulk density (BD) is critical to minimize aerobic deterioration facilitated by oxygen intrusion. To precisely assess packing quality for bunker silos, there is a desire to visualize the BD distribution within the silage. In this study, a penetrometer-based mapping system was developed. The data processing included filtering of the penetration friction component (PFC) out of the penetration resistance (PR), transfer of the corrected penetration resistance (PRc) to BD, incorporation of Kriged interpolation for data expansion and map generation. The experiment was conducted in a maize bunker silo (width: 8 m, middle height: 3 m). The BD distributions near the bunker silo face were represented using two map groups, one related to horizontal- and the other to vertical-density distribution patterns. We also presented a comparison between the map-based BD results and core sampling data. Agreement between the two measurement approaches (RMSE = 19.175 kg·m(-3)) demonstrates that the developed penetrometer mapping system may be beneficial for rapid assessment of aerobic deterioration potential in bunker silos.

  13. DEMONSTRATION BULLETIN: SITE CHARACTERIZATION ANALYSIS PENETROMETER SYSTEM (SCAPS) LIF SENSOR - U.S. ARMY, NAVY, AND AIR FORCE (TRI-SERVICES)

    Science.gov (United States)

    The Tri-Services Site Characterization Analysis Penetrometer System (SCAPS) was developed by the U.S. Army (U.S. Army Corps of Engineers, Waterways Experiment Station [WES] and the Army Environmental Center [AEC]), Navy (Naval Command, Control and Ocean Surveillance Center), and ...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

    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. Dimensional regularization and dimensional reduction in the light cone

    Science.gov (United States)

    Qiu, J.

    2008-06-01

    We calculate all of the 2 to 2 scattering process in Yang-Mills theory in the light cone gauge, with the dimensional regulator as the UV regulator. The IR is regulated with a cutoff in q+. It supplements our earlier work, where a Lorentz noncovariant regulator was used, and the final results bear some problems in gauge fixing. Supersymmetry relations among various amplitudes are checked by using the light cone superfields.

  17. Ejecta evolution during cone impact

    KAUST Repository

    Marston, Jeremy

    2014-07-07

    We present findings from an experimental investigation into the impact of solid cone-shaped bodies onto liquid pools. Using a variety of cone angles and liquid physical properties, we show that the ejecta formed during the impact exhibits self-similarity for all impact speeds for very low surface tension liquids, whilst for high-surface tension liquids similarity is only achieved at high impact speeds. We find that the ejecta tip can detach from the cone and that this phenomenon can be attributed to the air entrainment phenomenon. We analyse of a range of cone angles, including some ogive cones, and impact speeds in terms of the spatiotemporal evolution of the ejecta tip. Using superhydrophobic cones, we also examine the entry of cones which entrain an air layer.

  18. Light cone matrix product

    Energy Technology Data Exchange (ETDEWEB)

    Hastings, Matthew B [Los Alamos National Laboratory

    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.

  19. Shatter cones: Diagnostic impact signatures

    Science.gov (United States)

    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).

  20. Shatter cones: Diagnostic impact signatures

    International Nuclear Information System (INIS)

    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)

  1. Light cone thermodynamics

    Science.gov (United States)

    De Lorenzo, Tommaso; Perez, Alejandro

    2018-02-01

    We show that null surfaces defined by the outgoing and infalling wave fronts emanating from and arriving at a sphere in Minkowski spacetime have thermodynamical properties that are in strict formal correspondence with those of black hole horizons in curved spacetimes. Such null surfaces, made of pieces of light cones, are bifurcate conformal Killing horizons for suitable conformally stationary observers. They can be extremal and nonextremal depending on the radius of the shining sphere. Such conformal Killing horizons have a constant light cone (conformal) temperature, given by the standard expression in terms of the generalization of surface gravity for conformal Killing horizons. Exchanges of conformally invariant energy across the horizon are described by a first law where entropy changes are given by 1 /(4 ℓp2) of the changes of a geometric quantity with the meaning of horizon area in a suitable conformal frame. These conformal horizons satisfy the zeroth to the third laws of thermodynamics in an appropriate way. In the extremal case they become light cones associated with a single event; these have vanishing temperature as well as vanishing entropy.

  2. Cone rod dystrophies

    Directory of Open Access Journals (Sweden)

    Hamel Christian P

    2007-02-01

    Full Text Available Abstract 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

  3. Subtask 1.11 - Spectroscopic field screening of hazardous waste and toxic spills. Final report

    International Nuclear Information System (INIS)

    Grisanti, A.A.

    1997-10-01

    Techniques for the field characterization of soil contamination due to spillage of hazardous waste or toxic chemicals are time-consuming and expensive. Thus more economical, less time-intensive methods are needed to facilitate rapid field screening of contaminated sites. The overall objective of this project is to study the feasibility of using an evanescent field absorbance sensor Fourier transform infrared spectroscopic sensor coupled with cone penetrometry as a field screening method. The specific objectives of this project are as follows: design an accessory for use with FT-IR that interfaces the spectrometer to a cone penetrometer; characterize the response of the FT-IR accessory to selected hydrocarbons in a laboratory-simulated field environment; and determine the ability of the FT-IR-CPT instrument to measure hydrocarbon contamination in soil by direct comparison with a reference method (e.g., Soxhlet extraction followed by gas chromatography) to quantify hydrocarbons from the same soil

  4. Mouse models for cone degeneration.

    Science.gov (United States)

    Samardzija, Marijana; Grimm, Christian

    2014-01-01

    Loss of cone vision has devastating effects on everyday life. Even though much effort has been made to understand cone physiology and pathophysiology, no successful therapies are available for patients suffering from cone disorders. As complex retinal interactions cannot be studied in vitro, utilization of different animal models is inevitable. Due to recent advances in transgenesis, mice became the most popular animal model to study human diseases, also in ophthalmology. While there are similarities in retinal anatomy and pathophysiology between mice and humans, there are also differences, most importantly the lack of a cone-rich macula in mice. Instead, cones in mice are rare and distributed over the whole retina, which makes the analysis of cone pathophysiology very difficult in these animals. This hindrance is one of the reasons why our understanding of rod pathophysiological processes is much more advanced. Recently, however, the sparseness of cones was overcome by the generation of the Nrl (- / -) mouse that expresses only cone photoreceptors in the retina. This paper will give a brief overview of some of the known mouse models to study cone degeneration and discuss the current knowledge gained from the analysis of these models.

  5. Dirac cones in two-dimensional borane

    Science.gov (United States)

    Martinez-Canales, Miguel; Galeev, Timur R.; Boldyrev, Alexander I.; Pickard, Chris J.

    2017-11-01

    We introduce two-dimensional borane, a single-layered material of BH stoichiometry, with promising electronic properties. We show that, according to density functional theory calculations, two-dimensional borane is semimetallic, with two symmetry-related Dirac cones meeting right at the Fermi energy Ef. The curvature of the cones is lower than in graphene, thus closer to the ideal linear dispersion. Its structure, formed by a puckered trigonal boron network with hydrogen atoms connected to each boron atom, can be understood as distorted, hydrogenated borophene [Mannix et al., Science 350, 1513 (2015), 10.1126/science.aad1080]. Chemical bonding analysis reveals the boron layer in the network being bound by delocalized four-center two-electron σ bonds. Finally, we suggest high pressure could be a feasible route to synthesize two-dimensional borane.

  6. Null cone superspace supergravity

    International Nuclear Information System (INIS)

    Downes-Martin, S.G.

    1980-03-01

    The null cone formalism is used to derive a 2(N-1) parameter family of constraints for O(N) extended superspace supergravity. The invariance groups of these constraints is analysed and is found to be [subgroup U submanifold] contains GL(4,R) for N = 1, the submanifold being eliminated for N > 1. The invariance group defines non-Weyl rotations on the superbein which combine to form Weyl transformations on the supertangent space metric. The invariance of the supergravity Lagrangian under these transformations is discussed. (Auth.)

  7. Review on resonance cone fields

    International Nuclear Information System (INIS)

    Ohnuma, Toshiro.

    1980-02-01

    Resonance cone fields and lower hybrid heating are reviewed in this report. The resonance cone fields were reported by Fisher and Gould, and they proposed the use of the measurement of resonance cones and structure as a diagnostic tool to determine the plasma density and electron temperature in magnetoplasma. After the resonance cone, a wave-like disturbance persists. Ohnuma et al. have measured bending, reflection and ducting of resonance cones in detail. The thermal modes in inhomogeneous magnetoplasma were seen. The reflection of thermal mode near an electron plasma frequency layer and an insulating plate has been observed. The non-linear effects of resonance cones is reported. Monochromatic electron beam produces the noise of broad band whistler mode. Lower hybrid waves have been the subject of propagation from the edge of plasma to the lower hybrid layer. Linear lower hybrid waves were studied. The lower hybrid and ion acoustic waves radiated from a point source were observed. The parametric decay of finite-extent, cold electron plasma waves was studied. The lower hybrid cone radiated from a point source going along magnetic field lines was observed. Several experimental data on the lower hybrid heating in tokamak devices have been reported. The theories on resonance cones and lower hybrid waves are introduced in this report. (Kato, T.)

  8. Making An Impact: Shatter Cones

    Science.gov (United States)

    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,…

  9. The holographic entropy cone

    International Nuclear Information System (INIS)

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

    2015-01-01

    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.

  10. Dynamics of turtle cones.

    Science.gov (United States)

    Naka, K I; Itoh, M A; Chappell, R L

    1987-02-01

    The response dynamics of turtle photoreceptors (cones) were studied by the cross-correlation method using a white-noise-modulated light stimulus. Incremental responses were characterized by the kernels. White-noise-evoked responses with a peak-to-peak excursion of greater than 5 mV were linear, with mean square errors of approximately 8%, a degree of linearity comparable to the horizontal cell responses. Both a spot (0.17 mm diam) and a large field of light produced almost identical kernels. The amplitudes of receptor kernels obtained at various mean irradiances fitted approximately the Weber-Fechner relationship and the mean levels controlled both the amplitude and the response dynamics; kernels were slow and monophasic at low mean irradiance and were fast and biphasic at high mean irradiance. This is a parametric change and is a piecewise linearization. Horizontal cell kernels evoked by the small spot of light were monophasic and slower than the receptor kernels produced by the same stimulus. Larger spots of light or a steady annular illumination transformed the slow horizontal cell kernel into a fast kernel similar to those of the receptors. The slowing down of the kernel waveform was modeled by a simple low-pass circuit and the presumed feedback from horizontal cells onto cones did not appear to play a major role.

  11. QCD on the light cone

    International Nuclear Information System (INIS)

    Brodsky, S.J.

    1992-09-01

    The quantization of gauge theory at fixed light-cone time τ = t - z/c provides new perspectives for solving non-perturbative problems in quantum chromodynamics. The light-cone Fock state expansion provides both a precise definition of the relativistic wavefunctions of hadrons as bound-states of quarks and gluons and a general calculus for predicting QCD processes at the amplitude level. Applications to exclusive processes and weak decay amplitudes are discussed. The problem of computing the hadronic spectrum and the corresponding light-cone wavefunctions of QCD in one space and one time dimension has been successfully reduced to the diagonalization of a discrete representation of the light-cone Hamiltonian. The problems confronting the solution of gauge theories in 3 + 1 dimensions in the light-cone quantization formalism,, including zero modes and non-perturbative renormalization, are reviewed

  12. Cone and Seed Maturation of Southern Pines

    Science.gov (United States)

    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...

  13. Field portable petroleum analysis for validation of the site characterization and analysis penetrometer system petroleum, oil and lubricant sensor

    International Nuclear Information System (INIS)

    Davis, W.M.; Jones, P.; Porter, B.

    1995-01-01

    A petroleum, oil and lubricant (POL) sensor for the Site Characterization and Analysis Penetrometer System (SCAPS) has been developed by the Tri-Services (e.g. Army, Navy and Air Force) to characterize the distribution of POL contaminants on military sites. The sensor is based on the detection of POL contaminants using a laser induced fluorescence (LIF) spectrometer. The SCAPS POL sensor has been shown to be a valuable tool for the rapid screening of POL contamination in the subsurface. However, many factors can affect the LIF response of a particular fuel at a particular site. These include fuel type, age of spill (e.g. weathering) and soil type. The LIF sensor also detects fluorescence from any naturally occurring fluorophores, including humic substances and fluorescent minerals. These factors lead to the development of an independent procedure for the verification of the POL sensor response. This paper describes a field portable total recoverable petroleum hydrocarbon (TRPH) method based on EPA Method 418.1 and its application to on site validation of the SCAPS POL sensor response at a number of contaminated sites

  14. Light cone approach

    International Nuclear Information System (INIS)

    Brodsky, Stan

    1993-01-01

    One of the most challenging problems in theoretical high energy physics is to compute the bound state structure of the proton and other hadrons from quantum chromodynamics (QCD), the field theory of quarks and gluons. The goal is not only to calculate the spectrum of hadrons masses from first principles, but also to derive the momentum and spin distributions of the quarks and gluons which control high energy hadron interactions. One approach to these difficult calculations is to simulate QCD on an artificial lattice. Recently, several new methods based on ''light-cone'' quantization have been proposed as alternatives to lattice theory for solving non-perturbative problems in QCD and other field theories. The basic idea is a generalization of Heisenberg's pioneer matrix formulation of quantum mechanics: if one could numerically diagonalize the matrix of the Hamiltonian representing the underlying QCD interaction, then the resulting eigenvalues would give the hadron spectrum, while the corresponding eigenstates would describe each hadron in terms of its quark and gluon degrees of freedom

  15. In-situ Geotechnical Characterization of Wetland Channel Cross Sections in Coastal Louisiana Using a Portable Free-fall Penetrometer

    Science.gov (United States)

    Bilici, C.; Stark, N.; Ghose Hajra, M.

    2016-02-01

    Broader comprehension of sediment dynamics in wetland channels is essential to protect and restore wetland areas in a sustainable manner. This study focused on a wetland channel located west of Lake Borgne in coastal Louisiana. In-situ tests were performed using a portable free fall penetrometer (PFFP), targeting the characterization of wetland channel sediment characteristics and dynamics. Data were collected at 102 locations along 3 cross-channel transects. Results indicated distinct variations in sediment properties across the channel. Sediments located centrally in the channel were soft and exhibited a similar sediment strength along the channel (0.75 - 3.5 kPa at 20 cm below channel bed surface; 4 - 10 kPa at 100 cm). The sediment strength near the channel banks increased up to 20 kPa at 20 cm below channel bed, while sediment samples did not indicate a significant variation in sediment type. Thus, surficial sediments located at the center of channel appeared less consolidated than at the channel banks. This likely resulted from erosion removing looser sediments due to differences in channel flow patterns or wake waves from boat activity. Furthermore, the thickness of a loose sediment top layer varied for the opposing banks of transects. This may be related to local changes in channel shape. Particularly in meandering parts of the channels, loose sediment layers were limited up to a thickness of 5 cm at the outer bank of individual meanders, while it reached a thickness of 15 cm at the inner bank. This matched the expectations of erosion at the outer banks and deposition on the inner banks. At some locations, asymmetric sediment layers on opposing banks of channel transects were likely related to local channel tributaries. These tributaries may act as a sediment sink or source affecting sedimentation in the investigated channel.

  16. Identification of a melting type variant among peach (P. persica L. Batsch) fruit textures by a digital penetrometer.

    Science.gov (United States)

    Ciacciulli, Angelo; Chiozzotto, Remo; Attanasio, Giovanna; Cirilli, Marco; Bassi, Daniele

    2017-12-20

    The increase of peach (Prunus persica L. Batsch) fruit shelf-life is one of the most important objectives of breeding activities, as peach is a highly perishable fruit which undergoes rapid softening during ripening. The loss of fruit firmness is accompanied by a modification of textural properties. At least four distinct textures were described in peach: melting, non-melting, stony-hard, and slow-melting (better defined as "slow-softening"). Flesh textures are usually discriminated using different approaches, specific for each type. Objective of this work was the development of a reliable method to assess flesh texture variants in peach fruit, with special attention to the slow-softening type which is currently scored by sensorial evaluation. A puncture-based test using a digital penetrometer was performed on 20 accessions belonging to the four textural groups, obtaining a series of rheological measures related to mechanical flesh properties and including Young's Modulus, Upper Yield Point, and Slope of Yield Stress. Among the components of elasto-plastic behavior of the fruits, the texture dynamic index (TD) was shown to be a reliable parameter to distinguish the group of melting flesh texture from slow-softening, non-melting, and stony-hard, these last resulting characterized by similar mechanical properties. The TD index can be applied to discriminate slow-softening and melting fruits, although variability within the different texture groups suggests the existence of accessions with intermediate phenotypes and minor quantitative trait variation. The availability of an objective method to clearly distinguish the melting from the slow-softening phenotypes paves the road to phenotype segregating progenies in order to find molecular markers associated to the slow-softening trait. The TD index could be considered to determine different textures in fleshy fruits in preharvest and postharvest, to support evaluation of quality for the intended use. © 2017 Wiley

  17. Light-cone quantization and QCD phenomenology

    International Nuclear Information System (INIS)

    Brodsky, S.J.; Robertson, D.G.

    1995-01-01

    In principle, quantum chromodynamics provides a fundamental description of hadronic and nuclear structure and dynamics in terms of their elementary quark and gluon degrees of freedom. In practice, the direct application of QCD to reactions involving the structure of hadrons is extremely complex because of the interplay of nonperturbative effects such as color confinement and multi-quark coherence. A crucial tool in analyzing such phenomena is the use of relativistic light-cone quantum mechanics and Fock state methods to provide tractable and consistent treatments of relativistic many-body systems. In this article we present an overview of this formalism applied to QCD, focusing in particular on applications to the final states in deep inelastic lepton scattering that will be relevant for the proposed European Laboratory for Electrons (ELFE), HERMES, HERA, SLAC, and CEBAF. We begin with a brief introduction to light-cone field theory, stressing how it many allow the derivation of a constituent picture, analogous to the constituent quark model, from QCD. We then discuss several applications of the light-cone Fock state formalism to QCD phenomenology. The Fock state representation includes all quantum fluctuations of the hadron wavefunction, including far off-shell configurations such as intrinsic charm and, in the case of nuclei, hidden color. In some applications, such as exclusive processes at large momentum transfer, one can make first-principle predictions using factorization theorems which separate the hard perturbative dynamics from the nonpertubative physics associated with hadron binding. The Fock state components of the hadron with small transverse size, which dominate hard exclusive reactions, have small color dipole moments and thus diminished hadronic interactions. Thus QCD predicts minimal absorptive corrections, i.e., color transparency for quasi-elastic exclusive reactions in nuclear targets at large momentum transfer

  18. Gravitons and light cone fluctuations

    International Nuclear Information System (INIS)

    Ford, L.H.

    1995-01-01

    Gravitons in a squeezed vacuum state, the natural result of quantum creation in the early Universe or by black holes, will introduce metric fluctuations. These metric fluctuations will introduce fluctuations of the light cone. It is shown that when the various two-point functions of a quantized field are averaged over the metric fluctuations, the light cone singularity disappears for distinct points. The metric-averaged functions remain singular in the limit of coincident points. The metric-averaged retarded Green's function for a massless field becomes a Gaussian which is nonzero both inside and outside of the classical light cone. This implies some photons propagate faster than the classical light speed, whereas others propagate slower. The possible effects of metric fluctuations upon one-loop quantum processes are discussed and illustrated by the calculation of the one-loop electron self-energy

  19. Mach Cones in Viscous Matter

    Science.gov (United States)

    Bouras, I.; El, A.; Fochler, O.; Lauciello, F.; Reining, F.; Uphoff, J.; Wesp, C.; Molnar, E.; Niemi, H.; Xu, Z.; Greiner, C.

    2011-01-01

    Employing a microscopic transport model we investigate the evolution of high energetic jets moving through a viscous medium. For the scenario of an unstoppable jet we observe a clearly strong collective behavior for a low dissipative system η/s approx 0.005, leading to the observation of cone-like structures. Increasing the dissipation of the system to η/s approx 0.32 the Mach Cone structure vanishes. Furthermore, we investigate jet-associated particle correlations. A double-peak structure, as observed in experimental data, is even for low-dissipative systems not supported, because of the large influence of the head shock.

  20. Mach Cones in Viscous Matter

    Energy Technology Data Exchange (ETDEWEB)

    Bouras, I; El, A; Fochler, O; Lauciello, F; Reining, F; Uphoff, J; Wesp, C; Xu, Z; Greiner, C [Institut fuer Theoretische Physik, Johann Wolfgang Goethe-Universitat, Max-von-Laue-Str. 1, D-60438 Frankfurt am Main (Germany); Molnar, E; Niemi, H, E-mail: bouras@th.physik.uni-frankfurt.de [Frankfurt Institute for Advanced Studies, Ruth-Moufang-Str. 1, D-60438 Frankfurt am Main (Germany)

    2011-01-01

    Employing a microscopic transport model we investigate the evolution of high energetic jets moving through a viscous medium. For the scenario of an unstoppable jet we observe a clearly strong collective behavior for a low dissipative system {eta}/s {approx} 0.005, leading to the observation of cone-like structures. Increasing the dissipation of the system to {eta}/s {approx} 0.32 the Mach Cone structure vanishes. Furthermore, we investigate jet-associated particle correlations. A double-peak structure, as observed in experimental data, is even for low-dissipative systems not supported, because of the large influence of the head shock.

  1. Mach Cones in Viscous Matter

    International Nuclear Information System (INIS)

    Bouras, I; El, A; Fochler, O; Lauciello, F; Reining, F; Uphoff, J; Wesp, C; Xu, Z; Greiner, C; Molnar, E; Niemi, H

    2011-01-01

    Employing a microscopic transport model we investigate the evolution of high energetic jets moving through a viscous medium. For the scenario of an unstoppable jet we observe a clearly strong collective behavior for a low dissipative system η/s ∼ 0.005, leading to the observation of cone-like structures. Increasing the dissipation of the system to η/s ∼ 0.32 the Mach Cone structure vanishes. Furthermore, we investigate jet-associated particle correlations. A double-peak structure, as observed in experimental data, is even for low-dissipative systems not supported, because of the large influence of the head shock.

  2. Processing of the S-cone signals in the early visual cortex of primates.

    Science.gov (United States)

    Xiao, Youping

    2014-03-01

    The short-wavelength-sensitive (S) cones play an important role in color vision of primates, and may also contribute to the coding of other visual features, such as luminance and motion. The color signals carried by the S cones and other cone types are largely separated in the subcortical visual pathway. Studies on nonhuman primates or humans have suggested that these signals are combined in the striate cortex (V1) following a substantial amplification of the S-cone signals in the same area. In addition to reviewing these studies, this review describes the circuitry in V1 that may underlie the processing of the S-cone signals and the dynamics of this processing. It also relates the interaction between various cone signals in V1 to the results of some psychophysical and physiological studies on color perception, which leads to a discussion of a previous model, in which color perception is produced by a multistage processing of the cone signals. Finally, I discuss the processing of the S-cone signals in the extrastriate area V2.

  3. Bases for Cones and Reflexivity | Polyrakis | Quaestiones ...

    African Journals Online (AJOL)

    It is proved that a Banach space E is non-reflexive if and only if E has a closed cone with an unbounded, closed, dentable base. If E is a Banach lattice, the same characterization holds with the extra assumption that the cone is contained in E+. This article is also a survey of the geometry (dentability) of bases for cones.

  4. Intrinsic volumes of symmetric cones

    OpenAIRE

    Amelunxen, Dennis; Bürgisser, Peter

    2012-01-01

    We compute the intrinsic volumes of the cone of positive semidefinite matrices over the real numbers, over the complex numbers, and over the quaternions, in terms of integrals related to Mehta's integral. Several applications for the probabilistic analysis of semidefinite programming are given.

  5. DOS cones along atomic chains

    International Nuclear Information System (INIS)

    Kwapiński, Tomasz

    2017-01-01

    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. (paper)

  6. Seawave Slot-Cone Generator

    DEFF Research Database (Denmark)

    Vicinanza, Diego; Margheritini, Lucia; Contestabile, Pasquale

    2009-01-01

    This paper discusses a new type of Wave Energy Converter (WEC) named Seawave Slot-Cone Generator (SSG). The SSG is a WEC of the overtopping type. The structure consists of a number of reservoirs one on the top of each others above the mean water level in which the water of incoming waves is store...

  7. Comparação de penetrômetros na avaliação da compactação de latossolos Comparison of penetrometers to evaluate soil compactness in oxisols

    Directory of Open Access Journals (Sweden)

    Amauri N. Beutler

    2007-04-01

    Full Text Available Diversos penetrômetros são utilizados para avaliar a resistência do solo à penetração em sistemas de uso e manejo, no entanto os valores obtidos com os mesmos divergem. O objetivo deste estudo foi comparar os resultados obtidos com três penetrômetros, em três níveis de compactação. Utilizou-se de um Latossolo Vermelho distrófico (LVd, textura média, e um Latossolo Vermelho eutroférrico (LVef, textura argilosa, cujas amostras foram coletadas na camada de 0-20 cm e compactadas em camadas, em vasos de 25 cm de diâmetro e 20 cm de altura. Determinou-se a resistência do solo à penetração com os penetrômetros de impacto, estático de anel dinamométrico e eletrônico de laboratório. Em solo compactado, o penetrômetro de impacto apresentou valores superiores de resistência à penetração, comparado aos penetrômetros de anel dinamométrico e eletrônico, porém todos foram eficientes para caracterizar a compactação. Os resultados obtidos com os penetrômetros de anel dinamométrico e eletrônico foram semelhantes.Several penetrometers have been used to evaluate soil resistance to penetration in tillage systems. However, the values obtained with them, diverge. This research was carried out with the objective of comparing results obtained with three penetrometers in three levels of compactness, using soil samples collected at 0-20 cm depth of an Oxisol (Haplustox (LVd, medium texture, an Oxisol (Eutrustox (LVef and clayey texture. The soils were compacted in layers, in pots of 25 cm diameter and 20 cm height. Soil resistance to penetration with impact and and electronic dynamometrical ring penetrometers were determined. The impact penetrometer presented superior values of resistance to penetration in relation to the static and electronic dynamometrical ring penetrometers; moreover all were efficient to characterize soil compactness. The results obtained with the ring penetrometer and eletronic penetrometers were similar.

  8. cis Retinol oxidation regulates photoreceptor access to the retina visual cycle and cone pigment regeneration.

    Science.gov (United States)

    Sato, Shinya; Kefalov, Vladimir J

    2016-11-15

    cycle provides cones exclusively with 11-cis chromophore and this process is mediated by the 11-cis selective CRALBP in Müller cells. Finally, despite sharing the same pigment, salamander blue cones, but not green rods, recovered their sensitivity in the isolated retina. Exogenous 9-cis retinol produced robust sensitivity recovery in bleached red and blue cones but not in red and green rods, suggesting that cis retinol oxidation restricts access to the retina visual cycle to cones. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

  9. Prediction of Cone Crusher Performance Considering Liner Wear

    Directory of Open Access Journals (Sweden)

    Yanjun Ma

    2016-12-01

    Full Text Available Cone crushers are used in the aggregates and mining industries to crush rock material. The pressure on cone crusher liners is the key factor that influences the hydraulic pressure, power draw and liner wear. In order to dynamically analyze and calculate cone crusher performance along with liner wear, a series of experiments are performed to obtain the crushed rock material samples from a crushing plant at different time intervals. In this study, piston die tests are carried out and a model relating compression coefficient, compression ratio and particle size distribution to a corresponding pressure is presented. On this basis, a new wear prediction model is proposed combining the empirical model for predicting liner wear with time parameter. A simple and practical model, based on the wear model and interparticle breakage, is presented for calculating compression ratio of each crushing zone along with liner wear. Furthermore, the size distribution of the product is calculated based on existing size reduction process model. A method of analysis of product size distribution and shape in the crushing process considering liner wear is proposed. Finally, the validity of the wear model is verified via testing. The result shows that there is a significant improvement of the prediction of cone crusher performance considering liner wear as compared to the previous model.

  10. An alternative derivation of Katsevich's cone-beam reconstruction formula

    International Nuclear Information System (INIS)

    Chen Guanghong

    2003-01-01

    In this paper an alternative derivation of Katsevich's cone-beam image reconstruction algorithm is presented. The starting point is the classical Tuy's inversion formula. After (i) using the hidden symmetries of the intermediate functions, (ii) handling the redundant data by weighting them, (iii) changing the weighted average into an integral over the source trajectory parameter, and (iv) imposing an additional constraint on the weighting function, a filtered backprojection reconstruction formula from cone beam projections is derived. The following features are emphasized in the present paper: First, the nontangential condition in Tuy's original data sufficiency conditions has been relaxed. Second, a practical regularization scheme to handle the singularity is proposed. Third, the derivation in the cone beam case is in the same fashion as that in the fan-beam case. Our final cone-beam reconstruction formula is the same as the one discovered by Katsevich in his most recent paper. However, the data sufficiency conditions and the regularization scheme of singularities are different. A detailed comparison between these two methods is presented

  11. Cardiac cone-beam CT

    International Nuclear Information System (INIS)

    Manzke, Robert

    2005-01-01

    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

  12. Prescriptionless light-cone integrals

    International Nuclear Information System (INIS)

    Suzuki, A.T.; Schmidt, A.G.M.

    2000-01-01

    Perturbative quantum gauge field theory as seen within the perspective of physical gauge choices such as the light-cone gauge entails the emergence of troublesome poles of the type (k.n) -α in the Feynman integrals. These come from the boson field propagator, where α=1,2,.. and n μ is the external arbitrary four-vector that defines the gauge properly. This becomes an additional hurdle in the computation of Feynman diagrams, since any graph containing internal boson lines will inevitably produce integrands with denominators bearing the characteristic gauge-fixing factor. How one deals with them has been the subject of research over decades, and several prescriptions have been suggested and tried in the course of time, with failures and successes. However, a more recent development at this fronteer which applies the negative dimensional technique to compute light-cone Feynman integrals shows that we can altogether dispense with prescriptions to perform the calculations. An additional bonus comes to us attached to this new technique, in that not only it renders the light-cone prescriptionless but, by the very nature of it, it can also dispense with decomposition formulas or partial fractioning tricks used in the standard approach to separate pole products of the type (k.n) -α [(k-p).n] -β (β=1,2,..). In this work we demonstrate how all this can be done. (orig.)

  13. Cone-beam mammo-computed tomography from data along two tilting arcs

    International Nuclear Information System (INIS)

    Zeng Kai; Yu Hengyong; Fajardo, Laurie L.; Wang Ge

    2006-01-01

    Over the past several years there has been an increasing interest in cone-beam computed tomography (CT) for breast imaging. In this article, we propose a new scheme for theoretically exact cone-beam mammo-CT and develop a corresponding Katsevich-type reconstruction algorithm. In our scheme, cone-beam scans are performed along two tilting arcs to collect a sufficient amount of information for exact reconstruction. In our algorithm, cone-beam data are filtered in a shift-invariant fashion and then weighted backprojected into the three-dimensional space for the final reconstruction. Our approach has several desirable features, including tolerance of axial data truncation, efficiency in sequential/parallel implementation, and accuracy for quantitative analysis. We also demonstrate the system performance and clinical utility of the proposed technique in numerical simulations

  14. Programming Retinal Stem Cells into Cone Photoreceptors

    Science.gov (United States)

    2015-12-01

    researchers that want to reprogram stem cells for clinical applications. Lastly, we attempted to transplant cone photoreceptors derived from human retinal...AWARD NUMBER: W81XWH-14-1-0566 TITLE: Programming Retinal Stem Cells into Cone Photoreceptors PRINCIPAL INVESTIGATOR: Joseph A. Brzezinski IV...SUBTITLE 5a. CONTRACT NUMBER Programming Retinal Stem Cells into Cone Photoreceptors 5b. GRANT NUMBER W81XWH-14-1-0566 5c. PROGRAM ELEMENT NUMBER 6

  15. Case of Unilateral Peripheral Cone Dysfunction

    OpenAIRE

    Yujin Mochizuki; Kei Shinoda; Celso Soiti Matsumoto; Gerd Klose; Emiko Watanabe; Keisuke Seki; Itaru Kimura; Atsushi Mizota

    2012-01-01

    Purpose: Peripheral cone dystrophy is a subgroup of cone dystrophy, and only 4 cases have been reported. We present a patient with unilateral peripheral cone dysfunction and report the functional changes determined by electrophysiological tests and ultrastructural changes determined by spectral domain optical coherence tomography (SD-OCT). Case: A 34-year-old woman complained of blurred vision in both eyes. Our examination showed that her visual acuity was 0.05 OD and 0.2 OS. A relative affer...

  16. On generalized gravitational entropy, squashed cones and holography

    International Nuclear Information System (INIS)

    Bhattacharyya, Arpan; Sharma, Menika; Sinha, Aninda

    2014-01-01

    We consider generalized gravitational entropy in various higher derivative theories of gravity dual to four dimensional CFTs using the recently proposed regularization of squashed cones. We derive the universal terms in the entanglement entropy for spherical and cylindrical surfaces. This is achieved by constructing the Fefferman-Graham expansion for the leading order metrics for the bulk geometry and evaluating the generalized gravitational entropy. We further show that the Wald entropy evaluated in the bulk geometry constructed for the regularized squashed cones leads to the correct universal parts of the entanglement entropy for both spherical and cylindrical entangling surfaces. We comment on the relation with the Iyer-Wald formula for dynamical horizons relating entropy to a Noether charge. Finally we show how to derive the entangling surface equation in Gauss-Bonnet holography

  17. Cone Storage and Seed Quality in Longleaf Pine

    Science.gov (United States)

    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.

  18. Energy integration in south cone

    International Nuclear Information System (INIS)

    Ribeiro, M.A.K.

    1990-01-01

    The economic development of a geo-political region is directly related to the energy resources available to its productive system. The analysis carried out in this paper focus a region limited by Paraguay, Uruguay, the Argentina north and the Brazilian south, the core of the so called South Cone. The region has a diversified energy matrix that assures strong connections between the countries. The main resources available are hydroelectric but the approach gives a strong emphasis in coal and natural gas. The outlined model of a self sustained development of the region can be used as the foundation of the independent economic development of South America. (author)

  19. Correlation Between Cone Penetration Rate And Measured Cone Penetration Parameters In Silty Soils

    DEFF Research Database (Denmark)

    Poulsen, Rikke; Nielsen, Benjaminn Nordahl; Ibsen, Lars Bo

    2013-01-01

    This paper shows, how a change in cone penetration rate affects the cone penetration measurements, hence the cone resistance, pore pressure, and sleeve friction in silty soil. The standard rate of penetration is 20 mm/s, and it is generally accepted that undrained penetration occurs in clay while...... penetration tests with varying penetration rates conducted at a test site where the subsoil primary consists of sandy silt. It is shown how a reduced penetration rate influences the cone penetration measurements e.g. the cone resistance, pore pressure, and sleeve friction....

  20. Weighted vaginal cones for urinary incontinence.

    Science.gov (United States)

    Herbison, G Peter; Dean, Nicola

    2013-07-08

    For a long time pelvic floor muscle training (PFMT) has been the most common form of conservative (non-surgical) treatment for stress urinary incontinence (SUI). Weighted vaginal cones can be used to help women to train their pelvic floor muscles. Cones are inserted into the vagina and the pelvic floor is contracted to prevent them from slipping out. The objective of this review is to determine the effectiveness of vaginal cones in the management of female urinary stress incontinence (SUI).We wished to test the following comparisons in the management of stress incontinence: 1. vaginal cones versus no treatment; 2. vaginal cones versus other conservative therapies, such as PFMT and electrostimulation; 3. combining vaginal cones and another conservative therapy versus another conservative therapy alone or cones alone; 4. vaginal cones versus non-conservative methods, for example surgery or injectables.Secondary issues which were considered included whether:1. it takes less time to teach women to use cones than it does to teach the pelvic floor exercise; 2. self-taught use is effective;3. the change in weight of the heaviest cone that can be retained is related to the level of improvement;4. subgroups of women for whom cone use may be particularly effective can be identified. We searched the Cochrane Incontinence Group Specialised Trials Register (searched 19 September 2012), MEDLINE (January 1966 to March 2013), EMBASE (January 1988 to March 2013) and reference lists of relevant articles. Randomised or quasi-randomised controlled trials comparing weighted vaginal cones with alternative treatments or no treatment. Two reviewers independently assessed studies for inclusion and trial quality. Data were extracted by one reviewer and cross-checked by the other. Study authors were contacted for extra information. We included 23 trials involving 1806 women, of whom 717 received cones. All of the trials were small, and in many the quality was hard to judge. Outcome measures

  1. Prospective Randomized Trial for Image-Guided Biopsy Using Cone-Beam CT Navigation Compared with Conventional CT.

    Science.gov (United States)

    Abi-Jaoudeh, Nadine; Fisher, Teresa; Jacobus, John; Skopec, Marlene; Radaelli, Alessandro; Van Der Bom, Imramsjah Martijn; Wesley, Robert; Wood, Bradford J

    2016-09-01

    To compare cone-beam computed tomography (CT) navigation vs conventional CT image guidance during biopsies. Patients scheduled for image-guided biopsies were prospectively and randomly assigned to conventional CT guidance vs cone-beam CT navigation. Radiation dose, accuracy of final needle position, rate of histopathologic diagnosis, and number of needle repositions to reach the target (defined as pullback to adjust position) were compared. A total of 58 patients (mean age, 57 y; 62.1% men) were randomized: 29 patients underwent 33 biopsies with CT guidance and 29 patients with 33 lesions underwent biopsy with cone-beam CT navigation. The average body mass index (BMI) was similar between groups, at 28.8 kg/m(2) ± 6.55 (P = .18). There was no difference between groups in terms of patient and lesion characteristics (eg, size, depth). The average lesion size was 29.1 ± 12.7mm for CT group vs 32.1mm ±16.8mm for cone-beam CT group (P cone-beam CT group was 0.3 ± 0.5, compared with 1.9 ± 2.3 with conventional CT (P cone-beam CT than with conventional CT (P cone-beam CT vs conventional CT (P = .018). Accuracy, defined as the difference between planned and final needle positions, was 4.9 mm ± 4.1 for the cone-beam CT group, compared with 12.2 mm ± 8.1 for conventional CT (P cone-beam CT (P = .67). Cone-beam CT navigation for biopsies improved targeting accuracy with fewer needle repositions, lower skin entry dose, and lower effective dose for planning scan, and a comparable histopathologic diagnosis rate. Copyright © 2016 SIR. All rights reserved.

  2. A Hydraulically Operated Pine Cone Cutter

    Science.gov (United States)

    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...

  3. Cones and foci for protocol verification revisited

    NARCIS (Netherlands)

    W.J. Fokkink (Wan); J. Pang

    2002-01-01

    textabstractWe define a cones and foci proof method, which rephrases the question whether two system specifications are branching bisimilar in terms of proof obligations on relations between data objects. Compared to the original cones and foci method from Groote and Springintveld cite{GroSpr01},

  4. Cone calorimeter tests of wood composites

    Science.gov (United States)

    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...

  5. Double Dirac cones in phononic crystals

    KAUST Repository

    Li, Yan

    2014-07-07

    A double Dirac cone is realized at the center of the Brillouin zone of a two-dimensional phononic crystal (PC) consisting of a triangular array of core-shell-structure cylinders in water. The double Dirac cone is induced by the accidental degeneracy of two double-degenerate Bloch states. Using a perturbation method, we demonstrate that the double Dirac cone is composed of two identical and overlapping Dirac cones whose linear slopes can also be accurately predicted from the method. Because the double Dirac cone occurs at a relatively low frequency, a slab of the PC can be mapped onto a slab of zero refractive index material by using a standard retrieval method. Total transmission without phase change and energy tunneling at the double Dirac point frequency are unambiguously demonstrated by two examples. Potential applications can be expected in diverse fields such as acoustic wave manipulations and energy flow control.

  6. Cone penetration test for facies study: a review

    Science.gov (United States)

    Satriyo, N. A.; Soebowo, E.

    2018-02-01

    Engineering geology investigation through Cone Penetration Test (with pore-pressure measurements) approach is one of the most effective methods to find out sub surface layer. This method is generally used in Late Quaternary and typical deposit and can also be used for sedimentological purposes. CPTu and drilling core for high-resolution stratigraphy sub surface have been done in many research. These combined data can also be used to detail correlations of sub surface stratigraphy, to identify facies change and to determine the interpretation of sequence stratigraphy. The determination facies distribution research based on CPTu profile, which was included in quantitative data, is rarely done especially in Indonesia which has a different climate. Whereas drilling core description using grain size analysis will provide information on validation about physical lithology characteristics which are developed in research area. The interpretation is given using CPTu curve pattern and cone resistance parameter of CPTu’s data correlated with physical characteristics of drilling core. The cone resistance will provide the strength of the sediment layer which also gives the range of data between clay and sand. Finally, the review will show that each of developing facies characteristic provides a specific curve pattern and every sediment deposit facies can be determined by the transformation of CPTu curve profile. Despite the fact that the research using those methods are quite comprehensive, a review is presented on each of these methods related with the chronologic factor seen by the geological time and different characteristics sediment of different location.

  7. Design of a New Sensor for Determination of the Effects of Tractor Field Usage in Southern Spain: Soil Sinkage and Alterations in the Cone Index and Dry Bulk Density

    Directory of Open Access Journals (Sweden)

    Diego L. Valera

    2012-10-01

    Full Text Available Variations in sinkage and cone index are of crucial importance when planning fieldwork, and for determining the trafficability of farm machinery. Many studies have highlighted the link between higher values of these parameters and dramatic decreases in crop yield. Variations in the dry bulk density and cone index of clayey soil in Southern Spain were measured following each of five successive passes over the same land with the three types of tractor most widely used in the area (tracked, two-wheel drive and four-wheel drive. In addition, sinkage (rut depth of the running gear was measured using a laser microrelief profile meter. This device, which integrates three sensors, was specifically designed for these experiments, as was an electrical penetrometer to determine the cone index, and both instruments proved reliable and accurate in the field. The main goal of this study was to design, manufacture and test these new devices. The first pass caused most soil alteration when compared to successive passes for all types of tractor tested and soil conditions prevailing during the tests. (Heavier four-wheel drive tractors were found to cause greater soil damage (sinkage, cone index and dry bulk density than two-wheel drive and track tractors. There was no statistically significant difference between the two latter types. The greatest alterations were recorded in the top 10 cm of the soil. The results show that soil compaction should be avoided as much as possible. This can be achieved by ensuring that tractors always travel along the same tracks, especially in the wet season. At present these aspects are not considered by farmers in this area.

  8. The southern cone petroleum market

    International Nuclear Information System (INIS)

    Pisani, W.

    1992-01-01

    The Argentine oil sector has been moving strongly toward complete deregulation since 1989. Price controls on byproducts has been lifted, old petroleum contracts became into concessions, and the state oil company, YPF, is under process of privatization. In this context, the international companies scouting for opportunities can find an important menu of potential investments But here remain some problems connected with this deregulation, too. The lack of a reference crude and product market price is one of them. This paper focuses how to overcome this trouble with the establishment of an institutional market for crude and products, not only for Argentina but also for the entire Southern Cone Region (Argentina, Bolivia, Brazil, Chile, Paraguay and Uruguay), inquiring into the benefits of its creation

  9. Lyapunov Functions and Cone Families

    Science.gov (United States)

    Barreira, Luis; Dragičević, Davor; Valls, Claudia

    2012-07-01

    We describe systematically the relation between Lyapunov functions and nonvanishing Lyapunov exponents, both for maps and flows. This includes a brief survey of the existing results in the area. In particular, we consider separately the cases of nonpositive and arbitrary Lyapunov functions, thus yielding optimal criteria for negativity and positivity of the Lyapunov exponents of linear cocycles over measure-preserving transformations. Moreover, we describe converse results of these criteria with the explicit construction of eventually strict Lyapunov functions for any map or flow with nonzero Lyapunov exponents. We also construct examples showing that in general the existence of an eventually strict invariant cone family does not imply the existence of an eventually strict Lyapunov function.

  10. Dirac cones in isogonal hexagonal metallic structures

    Science.gov (United States)

    Wang, Kang

    2018-03-01

    A honeycomb hexagonal metallic lattice is equivalent to a triangular atomic one and cannot create Dirac cones in its electromagnetic wave spectrum. We study in this work the low-frequency electromagnetic band structures in isogonal hexagonal metallic lattices that are directly related to the honeycomb one and show that such structures can create Dirac cones. The band formation can be described by a tight-binding model that allows investigating, in terms of correlations between local resonance modes, the condition for the Dirac cones and the consequence of the third structure tile sustaining an extra resonance mode in the unit cell that induces band shifts and thus nonlinear deformation of the Dirac cones following the wave vectors departing from the Dirac points. We show further that, under structure deformation, the deformations of the Dirac cones result from two different correlation mechanisms, both reinforced by the lattice's metallic nature, which directly affects the resonance mode correlations. The isogonal structures provide new degrees of freedom for tuning the Dirac cones, allowing adjustment of the cone shape by modulating the structure tiles at the local scale without modifying the lattice periodicity and symmetry.

  11. Genetics Home Reference: cone-rod dystrophy

    Science.gov (United States)

    ... common cause of autosomal recessive cone-rod dystrophy , accounting for 30 to 60 percent of cases. At ... Patient Support and Advocacy Resources (4 links) American Foundation for the Blind Foundation Fighting Blindness Retina International ...

  12. On the Kleiman-Mori cone

    OpenAIRE

    Fujino, Osamu

    2005-01-01

    The Kleiman-Mori cone plays important roles in the birational geometry. In this paper, we construct complete varieties whose Kleiman-Mori cones have interesting properties. First, we construct a simple and explicit example of complete non-projective singular varieties for which Kleiman's ampleness criterion does not hold. More precisely, we construct a complete non-projective toric variety $X$ and a line bundle $L$ on $X$ such that $L$ is positive on $\\overline{\\mathit{NE...

  13. A novel mechanism of cone photoreceptor adaptation.

    Directory of Open Access Journals (Sweden)

    Marcus H C Howlett

    2017-04-01

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

  14. Modified superstring in light cone gauge

    International Nuclear Information System (INIS)

    Kamimura, Kiyoshi; Tatewaki, Machiko.

    1988-01-01

    We analyze the covariant superstring theory proposed by Siegel in light cone gauge. The physical states are the direct product of those of Green-Schwarz Superstring and the additional internal space spanned by light cone spinors. At clasical level, there is no difference among observables in Siegel's modified Superstring theory (SMST) and Green-Schwarz's one (GSST). However SMST can not be quantized with additional constraints as the physical state conditions. (author)

  15. Design of a trichromatic cone array.

    Directory of Open Access Journals (Sweden)

    Patrick Garrigan

    2010-02-01

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

  16. Human Visual Cortex Responses to Rapid Cone and Melanopsin-Directed Flicker.

    Science.gov (United States)

    Spitschan, Manuel; Datta, Ritobrato; Stern, Andrew M; Brainard, David H; Aguirre, Geoffrey K

    2016-02-03

    Signals from cones are recombined in postreceptoral channels [luminance, L + M; red-green, L - M; blue-yellow, S - (L + M)]. The melanopsin-containing retinal ganglion cells are also active at daytime light levels and recent psychophysical results suggest that melanopsin contributes to conscious vision in humans. Here, we measured BOLD fMRI responses to spectral modulations that separately targeted the postreceptoral cone channels and melanopsin. Responses to spatially uniform (27.5° field size, central 5° obscured) flicker at 0.5, 1, 2, 4, 8, 16, 32, and 64 Hz were recorded from areas V1, V2/V3, motion-sensitive area MT, and the lateral occipital complex. In V1 and V2/V3, higher temporal sensitivity was observed to L + M + S (16 Hz) compared with L - M flicker (8 Hz), consistent with psychophysical findings. Area MT was most sensitive to rapid (32 Hz) flicker of either L + M + S or L - M. We found S cone responses only in areas V1 and V2/V3 (peak frequency: 4-8 Hz). In addition, we studied an L + M modulation and found responses that were effectively identical at all temporal frequencies to those recorded for the L + M + S modulation. Finally, we measured the cortical response to melanopsin-directed flicker and compared this response with control modulations that addressed stimulus imprecision and the possibility of stimulation of cones in the shadow of retinal blood vessels (penumbral cones). For our stimulus conditions, melanopsin flicker did not elicit a cortical response exceeding that of the control modulations. We note that failure to control for penumbral cone stimulation could be mistaken for a melanopsin response. The retina contains cone photoreceptors and ganglion cells that contain the photopigment melanopsin. Cones provide brightness and color signals to visual cortex. Melanopsin influences circadian rhythm and the pupil, but its contribution to cortex and perception is less clear. We measured the response of human visual cortex with fMRI using

  17. Distinct and atypical intrinsic and extrinsic cell death pathways between photoreceptor cell types upon specific ablation of Ranbp2 in cone photoreceptors.

    Directory of Open Access Journals (Sweden)

    Kyoung-In Cho

    2013-06-01

    Full Text Available Non-autonomous cell-death is a cardinal feature of the disintegration of neural networks in neurodegenerative diseases, but the molecular bases of this process are poorly understood. The neural retina comprises a mosaic of rod and cone photoreceptors. Cone and rod photoreceptors degenerate upon rod-specific expression of heterogeneous mutations in functionally distinct genes, whereas cone-specific mutations are thought to cause only cone demise. Here we show that conditional ablation in cone photoreceptors of Ran-binding protein-2 (Ranbp2, a cell context-dependent pleiotropic protein linked to neuroprotection, familial necrotic encephalopathies, acute transverse myelitis and tumor-suppression, promotes early electrophysiological deficits, subcellular erosive destruction and non-apoptotic death of cones, whereas rod photoreceptors undergo cone-dependent non-autonomous apoptosis. Cone-specific Ranbp2 ablation causes the temporal activation of a cone-intrinsic molecular cascade highlighted by the early activation of metalloproteinase 11/stromelysin-3 and up-regulation of Crx and CoREST, followed by the down-modulation of cone-specific phototransduction genes, transient up-regulation of regulatory/survival genes and activation of caspase-7 without apoptosis. Conversely, PARP1+ -apoptotic rods develop upon sequential activation of caspase-9 and caspase-3 and loss of membrane permeability. Rod photoreceptor demise ceases upon cone degeneration. These findings reveal novel roles of Ranbp2 in the modulation of intrinsic and extrinsic cell death mechanisms and pathways. They also unveil a novel spatiotemporal paradigm of progression of neurodegeneration upon cell-specific genetic damage whereby a cone to rod non-autonomous death pathway with intrinsically distinct cell-type death manifestations is triggered by cell-specific loss of Ranbp2. Finally, this study casts new light onto cell-death mechanisms that may be shared by human dystrophies with distinct

  18. Final work plan: Expedited Site Characterization of the IES Industries, Inc., Site at Marshalltown, Iowa. Ames Expedited Site Characterization Project, Version 1.0

    Energy Technology Data Exchange (ETDEWEB)

    1994-04-04

    The overall goal of the Ames Laboratory Expedited Site Characterization (ESC) project is to evaluate and promote both innovative and state-of-the-practice site characterization and/or monitoring technologies. This will be accomplished by fielding both types of technologies together in the context of an expedited site characterization. The first site will be at a former manufactured gas plant (FMGP) in Marshalltown, Iowa. The project will field three areas of technology: geophysical, analytical, and data fusion. Geophysical technologies are designed to understand the subsurface geology to help predict fate and transport of the target contaminants. Analytical technologies/methods are designed to detect and quantify the target contaminants. Data fusion technology consists of software systems designed to rapidly integrate or fuse all site information into a conceptual site model that then becomes the decision making tool for the site team to plan subsequent sampling activity. Not all of the contaminants present can be located at the action level. Polynuclear aromatic hydrocarbons (PAHs) are the signature organics associated with the coal tar activities that took place at the site. As a result, PAHs were selected as the target compounds. Screening analytical instruments and nonintrusive geophysical techniques will be fielded to qualitatively map the spatial contaminant distribution. Soil gas surveys, immunoassay testing (IMA), innovative optical techniques, and passive organic sorbent sensors will be deployed along with the geophysical methods. Gas chromatography/mass spectrometry (GC/MS) instruments and a cone penetrometer system equipped with a laser-induced fluorescence (LIF) probe will quantitatively map the action level edges of the PAH plume(s). Samples will be taken both by the cone penetrometer test system (CPT) and the Geoprobe {reg_sign} sampler system.

  19. Problem of changing gauge in Polyakov's theory: Relation between light-cone and conformal gauges

    International Nuclear Information System (INIS)

    Tzani, R.

    1989-01-01

    The problem of the change of gauge in string theory is discussed in the context of the functional-integral formulation of the theory. The equivalence between the light-cone and conformal gauges is shown. By performing a proper change of variables in commuting and ghost fields in the functional integral of Polykov's theory, the string theory in the conformal gauge is obtained from the light-cone gauge-fixed theory. Finally, the problem of changing gauge has been generalized to the higher-genus surfaces. It has been shown that string theory in the conformal gauge is equivalent to the light-cone gauge-fixed theory of strings, for surfaces with an arbitrary number of handles

  20. Light-cone superspace BPS equations, and OSp(2, 2|16)

    Science.gov (United States)

    Hearin, Patrick

    The BPS bound is formulated in light-cone superspace for the N = 4 superYang-Mills theory. As a consequence of the superalgebra all momenta are shown to be expressed as quadratic forms in the relevant supertransformations, and these forms are used to derive the light-cone superspace BPS equations. Finally, the superfield expressions are expanded out to component form, and the Wu-Yang Monopole boosted to the infinite momentum frame is shown to be a solution. A possible non-linear realization of the OSp(2, 2|16) superconformal algebra is prescribed with methods used to derive the OSp(2, 2|8) theory in light-cone superspace. This theory is shown to have an inconsistency in the dynamical constraints which cannot be resolved, and no non-linear field theory can be consistently realized. This inconsistency is derived in the covariant OSp(2, 2|16) theory.

  1. Experimental investigations of the unsteady flow in a Francis turbine draft tube cone

    International Nuclear Information System (INIS)

    Baya, A; Muntean, S; Campian, V C; Cuzmos, A; Diaconescu, M; Balan, G

    2010-01-01

    Operating Francis turbines at partial discharge is often hindered by the development of the helical vortex (so-called vortex rope) downstream the runner, in the draft tube cone. The unsteady pressure field induced by precessing vortex rope leads to pressure fluctuations. The paper presents the experimental investigations of the unsteady pressure field generated by precessing vortex rope and its associated pressure fluctuations into a draft tube of the Francis turbine operating at partial discharge. In situ measurements are performed in order to evaluate the pressure fluctuations and vortex rope frequency at partial load operation. Three pressure taps are installed on the cone wall of the draft tube in order to record the unsteady pressure. As a result, the Fourier spectra are obtained in order to evaluate the amplitude of pressure fluctuations and vortex rope frequency. Moreover, the wall pressure recovery along to the draft tube cone is acquired. Finally, conclusions are drawn in order to present the vortex rope effects.

  2. Experimental investigations of the unsteady flow in a Francis turbine draft tube cone

    Energy Technology Data Exchange (ETDEWEB)

    Baya, A [Department of Hydraulic Machinery, ' Politehnica' University of Timisoara Bv. Mihai Viteazu 1, RO-300222, Timisoara (Romania); Muntean, S [Centre of Advanced Research in Engineering Sciences, Romanian Academy - Timisoara Branch Bv. Mihai Viteazu 24, RO-300223, Timisoara (Romania); Campian, V C; Cuzmos, A [Research Center in Hydraulics, Automation and Heat Transfer, ' Eftimie Murgu' University of Resita P-ta. Traian Vuia 1-4, RO-320085, Resita (Romania); Diaconescu, M; Balan, G, E-mail: abaya@mh.mec.upt.r [Ramnicu Valcea Subsidiary, S.C. Hidroelectrica S.A. Str. Decebal 11, RO-240255, Ramnicu Valcea (Romania)

    2010-08-15

    Operating Francis turbines at partial discharge is often hindered by the development of the helical vortex (so-called vortex rope) downstream the runner, in the draft tube cone. The unsteady pressure field induced by precessing vortex rope leads to pressure fluctuations. The paper presents the experimental investigations of the unsteady pressure field generated by precessing vortex rope and its associated pressure fluctuations into a draft tube of the Francis turbine operating at partial discharge. In situ measurements are performed in order to evaluate the pressure fluctuations and vortex rope frequency at partial load operation. Three pressure taps are installed on the cone wall of the draft tube in order to record the unsteady pressure. As a result, the Fourier spectra are obtained in order to evaluate the amplitude of pressure fluctuations and vortex rope frequency. Moreover, the wall pressure recovery along to the draft tube cone is acquired. Finally, conclusions are drawn in order to present the vortex rope effects.

  3. Yang-Mills instantons on cones and sine-cones over nearly Kähler manifolds

    Science.gov (United States)

    Gemmer, Karl-Philip; Lechtenfeld, Olaf; Nölle, Christoph; Popov, Alexander D.

    2011-09-01

    We present a unified eight-dimensional approach to instanton equations on several seven-dimensional manifolds associated to a six-dimensional homogeneous nearly Kähler manifold. The cone over the sine-cone on a nearly Kähler manifold has holonomy group Spin(7) and can befoliated by submanifolds with either holonomy group G 2, a nearly parallel G 2-structure or a cocalibrated G 2-structure. We show that there is a G 2-instanton on each of these seven-dimensional manifolds which gives rise to a Spin(7)-instanton in eight dimensions. The well-known octonionic instantons on {mathbb{R}^7} and {mathbb{R}^8} are contained in our construction as the special cases of an instanton on the cone and on the cone over the sine-cone, both over the six-sphere, respectively.

  4. CRALBP supports the mammalian retinal visual cycle and cone vision

    OpenAIRE

    Xue, Yunlu; Shen, Susan Q.; Jui, Jonathan; Rupp, Alan C.; Byrne, Leah C.; Hattar, Samer; Flannery, John G.; Corbo, Joseph C.; Kefalov, Vladimir J.

    2015-01-01

    Mutations in the cellular retinaldehyde-binding protein (CRALBP, encoded by RLBP1) can lead to severe cone photoreceptor-mediated vision loss in patients. It is not known how CRALBP supports cone function or how altered CRALBP leads to cone dysfunction. Here, we determined that deletion of Rlbp1 in mice impairs the retinal visual cycle. Mice lacking CRALBP exhibited M-opsin mislocalization, M-cone loss, and impaired cone-driven visual behavior and light responses. Additionally, M-cone dark ad...

  5. Compound pollen cone in a Paleozoic conifer.

    Science.gov (United States)

    Hernandez-Castillo, G R; Rothwell, G W; Mapes, G

    2001-06-01

    A rich fossil biota from a Pennsylvanian age deposit of eastern North America contains numerous vegetative and fertile specimens that conform to a single species of primitive walchian conifers. Among the specimens is a compound pollen cone that comprises closely spaced, helically arranged, leaf-like bracts with axillary dwarf shoots. The specimen looks superficially similar to an ultimate vegetative conifer shoot, but there are small appendages in the axil of each bract that represent the fertile dwarf shoots. Dwarf shoots consist of an axis that bears sterile scales and sporophylls with erect pollen sacs. Pollen found in the sacs is monosaccate and conforms to the sporae dispersae genus Potonieisporites Bhardwaj. This cone is a compound shoot system that is morphologically equivalent to the ovulate cones of conifers and to the pollen cones of Paleozoic cordaitaleans and modern gnetophytes. Therefore, it is fundamentally different from the simple pollen cones of other fossil and modern conifers. Discovery of this specimen unexpectedly supports molecular studies that predict a close relationship between Coniferales and Gnetales, and provides fossil evidence to help reconcile the discordant phylogenetic hypotheses of seed plant systematics that have been developed from morphological and molecular data.

  6. Resonance cones in non-Maxwellian plasmas

    International Nuclear Information System (INIS)

    Oelerich-Hill, G.; Piel, A.

    1989-01-01

    Resonance cones are studied experimentally in hot drifting plasmas and in various beam--plasma situations. In a drifting plasma the upstream--downstream asymmetry of the main cone is suitable for diagnostics of plasma drifts. The evaluation of electron temperature from the interference pattern is discussed in terms of the low-temperature--low-drift approximation (LTLDA) and by comparing with numerical kinetic theory calculations. In this way the range of applicability of this method is extended above the LTLDA. In a beam--plasma situation, the downstream resonance cone exhibits a new interference pattern, which can be attributed to resonant particle effects. The upstream resonance cone is only slightly affected and is found still applicable for T/sub e/ and n/sub e/ diagnostics. As a result of comparison with numerical calculations, in which the actual distribution function is used, the downstream interference pattern is proposed to be useful as a diagnostic method for obtaining the mean beam energy. The waves generated by the beam--plasma interaction are analyzed by digital cross-correlation techniques, and found to propagate obliquely to the magnetic field direction at the resonance cone angle

  7. Resonance cones in non-Maxwellian plasmas

    International Nuclear Information System (INIS)

    Oelerich-Hill, G.; Piel, A.

    1988-05-01

    Resonance cones are studied experimentally in hot drifting plasmas and in various beam-plasma situations. In a drifting plasma the upstream-downstream asymmetry of the main cone is suitable for diagnostics of plasma drifts. The evaluation of electron temperature from the interference pattern is discussed in terms of the low-temperature-low-drift-approximation (LTLDA) and by comparing with numerical kinetic theory calculations. In this way the range of applicability of this method is extended above the LTLDA. In a beam-plasma situation, the downstream resonance cone exhibits a new interference pattern, which can be attributed to resonant particle effects. The upstream resonance cone is only slightly affected and is found still applicable for T e and n e diagnostics. As a result of the comparison with numerical calculations, in which the actual distribution function is used, the downstream interference pattern is proposed to be useful as a diagnostic method for obtaining the mean beam energy. The waves generated by the beam plasma interaction are analyzed by digital cross-correlation techniques. They are found to be Whistler waves propagating obliquely to the magnetic field direction at the resonance cone angle. (orig.)

  8. Light-cone averages in a Swiss-cheese universe

    International Nuclear Information System (INIS)

    Marra, Valerio; Kolb, Edward W.; Matarrese, Sabino

    2008-01-01

    We analyze a toy Swiss-cheese cosmological model to study the averaging problem. In our Swiss-cheese model, the cheese is a spatially flat, matter only, Friedmann-Robertson-Walker solution (i.e., the Einstein-de Sitter model), and the holes are constructed from a Lemaitre-Tolman-Bondi solution of Einstein's equations. We study the propagation of photons in the Swiss-cheese model, and find a phenomenological homogeneous model to describe observables. Following a fitting procedure based on light-cone averages, we find that the expansion scalar is unaffected by the inhomogeneities (i.e., the phenomenological homogeneous model is the cheese model). This is because of the spherical symmetry of the model; it is unclear whether the expansion scalar will be affected by nonspherical voids. However, the light-cone average of the density as a function of redshift is affected by inhomogeneities. The effect arises because, as the universe evolves, a photon spends more and more time in the (large) voids than in the (thin) high-density structures. The phenomenological homogeneous model describing the light-cone average of the density is similar to the ΛCDM concordance model. It is interesting that, although the sole source in the Swiss-cheese model is matter, the phenomenological homogeneous model behaves as if it has a dark-energy component. Finally, we study how the equation of state of the phenomenological homogeneous model depends on the size of the inhomogeneities, and find that the equation-of-state parameters w 0 and w a follow a power-law dependence with a scaling exponent equal to unity. That is, the equation of state depends linearly on the distance the photon travels through voids. We conclude that, within our toy model, the holes must have a present size of about 250 Mpc to be able to mimic the concordance model

  9. Identifying quantitative trait loci and determining closely related stalk traits for rind penetrometer resistance in a high-oil maize population.

    Science.gov (United States)

    Hu, Haixiao; Meng, Yujie; Wang, Hongwu; Liu, Hai; Chen, Shaojiang

    2012-05-01

    Stalk lodging in maize causes annual yield losses between 5 and 20% worldwide. Many studies have indicated that maize stalk strength significantly negatively correlates with lodging observed in the field. Rind penetrometer resistance (RPR) measurements can be used to effectively evaluate maize stalk strength, but little is known about the genetic basis of this parameter. The objective of this study was to explore a genetic model and detect quantitative trait loci (QTL) of RPR and determine relationships between RPR and other stalk traits, especially cell wall chemical components. RPR is quantitative trait in nature, and both additive and non-additive effects may be important to consider for the improvement of RPR. Nine additive-effect QTLs covering nine chromosomes, except chromosome 5, and one pair of epistatic QTLs were detected for RPR. CeSA11 involved in cellulose synthesis and colorless2 involved in lignin synthesis were identified as possible candidate genes for RPR. Internode diameter (InD), fresh weight of internode (FreW), dry weight of internode (DryW), fresh weight and dry weight as well as cell wall components per unit volume significantly positively correlated with RPR. The internode water content (InW) significantly negatively correlated with RPR. Notably, these traits significantly correlated with RPR, and the QTLs of these traits co-localized with those of RPR. The corresponding results obtained from correlation analysis and QTL mapping suggested the presence of pleitropism or linkage between genes and indicated that these different approaches may be used for cross authentication of relationships between different traits.

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

    Science.gov (United States)

    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

  11. Resonance in a Cone-Topped Tube

    Directory of Open Access Journals (Sweden)

    Angus Cheng-Huan Chia

    2011-06-01

    Full Text Available The relationship between ratio of the upper opening diameter of a cone-topped cylinder to the cylinder diameter,and the ratio of the length of the air column to resonant period was examined. Plastic cones with upper openings ranging from 1.3 cm to 3.6 cm and tuning forks with frequencies ranging from 261.6 Hz to 523.3 Hz were used. The transition from a standing wave in a cylindrical column to a Helmholtz-type resonance in a resonant cavity with a narrow opening was observed.

  12. Integrity of the cone photoreceptor mosaic in oligocone trichromacy

    DEFF Research Database (Denmark)

    Michaelides, Michel; Rha, Jungtae; Dees, Elise W

    2011-01-01

    Oligocone trichromacy (OT) is an unusual cone dysfunction syndrome characterized by reduced visual acuity, mild photophobia, reduced amplitude of the cone electroretinogram with normal rod responses, normal fundus appearance, and normal or near-normal color vision. It has been proposed that these...... that these patients have a reduced number of normal functioning cones (oligocone). This paper has sought to evaluate the integrity of the cone photoreceptor mosaic in four patients previously described as having OT....

  13. Oblique cone formation in Ge by Ar+ sputtering

    International Nuclear Information System (INIS)

    Chini, T.K.; Bhattaracharyya, S.R.; Ghose, D.; Basu, D.

    1992-01-01

    Sharp oblique cones are only formed on polished germanium surfaces by 30 keV Ar + bombardment, in the presence of tungsten seed atoms; substantiating Wehner's hypothesis that higher melting point seed material is the crucial factor for cone formation. The morphology of the cone is characterized by the formation of a sloped ridge, consistent with the observations of earlier workers. Moreover, some strange wing-like structures are associated with these cones. (author)

  14. Porous metal cones: gold standard for massive bone loss in complex revision knee arthroplasty? A systematic review of current literature.

    Science.gov (United States)

    Divano, Stefano; Cavagnaro, Luca; Zanirato, Andrea; Basso, Marco; Felli, Lamberto; Formica, Matteo

    2018-04-18

    Revision knee arthroplasty is increasing, and in that case, bone loss management is still a challenging problem. In the last years, the body of literature and interest surrounding porous metal cones has grown, but few systematic evaluations of the existing evidence have been performed. The aim of our systematic review is to collect and critically analyze the available evidence about metal cones in revision knee arthroplasty especially focusing our attention on indications, results, complications, and infection rate of these promising orthopaedic devices. We performed a systematic review of the available English literature, considering the outcomes and the complications of tantalum cones. The combinations of keyword were "porous metal cones", "knee revision", "bone loss", "knee arthroplasty", "periprosthetic joint infection", and "outcome". From the starting 312 papers available, 20 manuscripts were finally included. Only one included study has a control group. The main indication for metal cones is type IIb and III defects according AORI classification. Most of the papers show good clinical and radiological outcomes with low rate of complications. The examined studies provide encouraging clinical and radiological short-to-mid-term outcomes. Clinical studies have shown a low rate of aseptic loosening, intraoperative fractures, infection rate and a lower failure rate than the previous treatment methods. Higher quality papers are needed to draw definitive conclusions about porous metal cones.

  15. Cones and craters on Mount Pavagadh, Deccan Traps: Rootless ...

    Indian Academy of Sciences (India)

    Rootless cones, also (erroneously) called pseudocraters, form due to explosions that ensue when a lava flow enters a surface water body, ice, or wet ground. They do not represent primary vents connected by vertical conduits to a subsurface magma source. Rootless cones in Iceland are well studied. Cones on Mars ...

  16. Cones and craters on Mount Pavagadh, Deccan Traps: Rootless ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Rootless cones, also (erroneously) called pseudocraters, form due to explosions that ensue when a lava flow enters a surface water body, ice, or wet ground. They do not represent primary vents connected by vertical conduits to a subsurface magma source. Rootless cones in Iceland are well studied. Cones on Mars ...

  17. Distribution of the cone insect, Dioryctria disclusa, in red pine.

    Science.gov (United States)

    William J. Mattson

    1976-01-01

    Within the crowns of red pine, Pinus resinosa Ait., trees, larvae of the cone insect, Dioryctria disclusa Heinrich, tended to follow the distributions of their foods. Between-tree distributions of larvae, however, were relatable to food distributions in only two of five years. Cone damage/tree by D. disclusa increased linearly with cone abundance per tree when insect...

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

    International Nuclear Information System (INIS)

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

    2009-01-01

    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.

  19. [Electrical stimulation of the pelvic floor versus vaginal cone therapy for the treatment of stress urinary incontinence].

    Science.gov (United States)

    Santos, Patrícia Fernandes Diniz; Oliveira, Emerson; Zanetti, Miriam Raquel Diniz; Arruda, Raquel Martins; Sartori, Marair Gracio Ferreira; Girão, Manoel João Batista Castello; Castro, Rodrigo Aquino

    2009-09-01

    to compare the effects of functional electrostimulation of the pelvic floor and therapy with cones in women with stress urinary incontinence (SUI). randomized clinical study for which 45 patients with SUI were selected. The effects of functional electrostimulation of the pelvic floor were evaluated in the SUI treatment of 24 women, with the use of clinical data (micturition diary, pad test and a questionnaire about quality of life - I-QoL). The patients were submitted to two 20' weekly sessions for four consecutive months, under the supervision of a physiotherapist. The electrode used had 10 cm length and 3.5 cm width with a double metallic ring and a cylindrical shape, positioned in the medium third of the vagina. The electric parameters used were: intensity varying from 10 to 100 mA and 50 Hz of fixed frequency, with pulse duration of 1 ms. Also, we evaluated 21 patients who were submitted to vaginal cone treatment. The cone therapy was done with two 45 minute sessions per week. The cones' weight varied from 20 to 100 gr. there was no difference between the outcomes of electrostimulation of the pelvic floor and the vaginal cones for the treatment of SUI (p>0.05). After four months, there was a significant improvement in the I-QoL index of the patients treated both with electrostimulation (40.3 versus 82.9) or with the cones (47.7 versus 84.1). There was a significant decrease in pad weight in both groups, measured before and after the treatment (28.5 and 32 g versus 2.0 and 3.0 g for the electrostimulation and cone group, respectively). Finally, there was a significant decrease in the number of urinary leakage evaluated by the micturition diary in both groups (p<0.0001). both electrostimulation and vaginal cones were effective in the treatment of women with SUI.

  20. Supersonic Laminar Viscous Flow Past a Cone at Angle of Attack in Spinning and Coning Motion

    Science.gov (United States)

    Agarwal, Ramesh; Rakich, John V.

    1982-01-01

    Computational results obtained with a parabolic Navier-Stokes marching code are presented for supersonic viscous flow past a pointed cone at angle of attack undergoing a combined spinning and coning motion. The code takes into account the asymmetries in the flowfield resulting from the motion and computes the asymmetric shock shape, crossflow and streamwise shear, heat transfer, crossflow separation and vortex structure. The side force and moment are also computed. Reasonably good agreement is obtained with the side force measurements of Schiff and Tobak. Comparison is also made with the only available numerical inviscid analysis. It is found that the asymmetric pressure loads due lo coning motion are much larger than all other viscous forces due lo spin and coning, making viscous forces negligible in the combined motion.

  1. Still in Light-Cone Superspace

    Science.gov (United States)

    Ramond, P.

    2010-01-01

    The recently formulated Bagger-Lambert-Gustavsson (BLG) theory in three dimensions is described in terms of a constrained chiral superfield in light-cone superspace. We discuss the use of Superconformal symmetry to determine the form of its interactions, in complete analogy with N = 4 Super Yang-Mills in four dimensions.

  2. Analog Experiment for rootless cone eruption

    Science.gov (United States)

    Noguchi, R.; Hamada, A.; Suzuki, A.; Kurita, K.

    2017-09-01

    Rootless cone is a unique geomorphological landmark to specify igneous origin of investigated terrane, which is formed by magma-water interaction. To understand its formation mechanism we conducted analog experiment for heat-induced vesiculation by using hot syrup and sodium bicarbonate solution.

  3. Epigenomic landscapes of retinal rods and cones

    Science.gov (United States)

    Mo, Alisa; Luo, Chongyuan; Davis, Fred P; Mukamel, Eran A; Henry, Gilbert L; Nery, Joseph R; Urich, Mark A; Picard, Serge; Lister, Ryan; Eddy, Sean R; Beer, Michael A; Ecker, Joseph R; Nathans, Jeremy

    2016-01-01

    Rod and cone photoreceptors are highly similar in many respects but they have important functional and molecular differences. Here, we investigate genome-wide patterns of DNA methylation and chromatin accessibility in mouse rods and cones and correlate differences in these features with gene expression, histone marks, transcription factor binding, and DNA sequence motifs. Loss of NR2E3 in rods shifts their epigenomes to a more cone-like state. The data further reveal wide differences in DNA methylation between retinal photoreceptors and brain neurons. Surprisingly, we also find a substantial fraction of DNA hypo-methylated regions in adult rods that are not in active chromatin. Many of these regions exhibit hallmarks of regulatory regions that were active earlier in neuronal development, suggesting that these regions could remain undermethylated due to the highly compact chromatin in mature rods. This work defines the epigenomic landscapes of rods and cones, revealing features relevant to photoreceptor development and function. DOI: http://dx.doi.org/10.7554/eLife.11613.001 PMID:26949250

  4. Chloride equilibrium potential in salamander cones

    Directory of Open Access Journals (Sweden)

    Bryson Eric J

    2004-12-01

    Full Text Available Abstract Background GABAergic inhibition and effects of intracellular chloride ions on calcium channel activity have been proposed to regulate neurotransmission from photoreceptors. To assess the impact of these and other chloride-dependent mechanisms on release from cones, the chloride equilibrium potential (ECl was determined in red-sensitive, large single cones from the tiger salamander retinal slice. Results Whole cell recordings were done using gramicidin perforated patch techniques to maintain endogenous Cl- levels. Membrane potentials were corrected for liquid junction potentials. Cone resting potentials were found to average -46 mV. To measure ECl, we applied long depolarizing steps to activate the calcium-activated chloride current (ICl(Ca and then determined the reversal potential for the current component that was inhibited by the Cl- channel blocker, niflumic acid. With this method, ECl was found to average -46 mV. In a complementary approach, we used a Cl-sensitive dye, MEQ, to measure the Cl- flux produced by depolarization with elevated concentrations of K+. The membrane potentials produced by the various high K+ solutions were measured in separate current clamp experiments. Consistent with electrophysiological experiments, MEQ fluorescence measurements indicated that ECl was below -36 mV. Conclusions The results of this study indicate that ECl is close to the dark resting potential. This will minimize the impact of chloride-dependent presynaptic mechanisms in cone terminals involving GABAa receptors, glutamate transporters and ICl(Ca.

  5. Cone beam computed tomography in veterinary dentistry

    NARCIS (Netherlands)

    van Thielen, B.; Siguenza, F.; Hassan, B.

    2012-01-01

    The purpose of this study was to assess the feasibility of cone beam computed tomography (CBCT) in imaging dogs and cats for diagnostic dental veterinary applications. CBCT scans of heads of six dogs and two cats were made. Dental panoramic and multi-planar reformatted (MPR) para-sagittal

  6. Characterization of a cone beam optical scanner

    International Nuclear Information System (INIS)

    Ravindran, P B; Thomas, H M

    2013-01-01

    The use of radiochromic FX gel for mapping 3D dose distribution is hampered by the diffusion of gel and the slow scanning techniques. The development of fast optical cone beam scanning has improved the chances of using radiochromic gel as a feasible dosimeter for radiotherapy applications. In this work an optical cone beam scanner has been developed in-house and its performance characteristics have been studied. The reconstructed image of the optical scanner was analyzed by studying the resolution, signal-to-noise ratio and contrast to noise ratio (CNR). The resolution of the optical cone beam CT scanner was studied by scanning a catheter of 1 mm outer diameter and the scanner was able to detect the catheter. The geometrical accuracy of the reconstruction was studied by placing catheters in spiral geometry in the gel phantom and measuring the distances. It has been observed that the in-house Optical Cone beam scanner is suitable for scanning radiochromic gels for radiotherapy applications.

  7. Cone beam CT, wat moet ik ermee?

    NARCIS (Netherlands)

    Hoogeveen, R.

    2013-01-01

    De cone beam-ct-scan (cbct-scan) maakt een opmars in de tandheelkunde vanwege de toegevoegde waarde van de derde dimensie in de diagnostiek. Deze extra informatie wordt verkregen ten koste van een hogere stralenbelasting en een daarmee gepaard gaand hoger risico voor de patiënt. Om de clinicus te

  8. Perturbation theory in light-cone quantization

    Energy Technology Data Exchange (ETDEWEB)

    Langnau, Alex [Stanford Univ., CA (United States)

    1992-01-01

    A thorough investigation of light-cone properties which are characteristic for higher dimensions is very important. The easiest way of addressing these issues is by analyzing the perturbative structure of light-cone field theories first. Perturbative studies cannot be substituted for an analysis of problems related to a nonperturbative approach. However, in order to lay down groundwork for upcoming nonperturbative studies, it is indispensable to validate the renormalization methods at the perturbative level, i.e., to gain control over the perturbative treatment first. A clear understanding of divergences in perturbation theory, as well as their numerical treatment, is a necessary first step towards formulating such a program. The first objective of this dissertation is to clarify this issue, at least in second and fourth-order in perturbation theory. The work in this dissertation can provide guidance for the choice of counterterms in Discrete Light-Cone Quantization or the Tamm-Dancoff approach. A second objective of this work is the study of light-cone perturbation theory as a competitive tool for conducting perturbative Feynman diagram calculations. Feynman perturbation theory has become the most practical tool for computing cross sections in high energy physics and other physical properties of field theory. Although this standard covariant method has been applied to a great range of problems, computations beyond one-loop corrections are very difficult. Because of the algebraic complexity of the Feynman calculations in higher-order perturbation theory, it is desirable to automatize Feynman diagram calculations so that algebraic manipulation programs can carry out almost the entire calculation. This thesis presents a step in this direction. The technique we are elaborating on here is known as light-cone perturbation theory.

  9. Computer aided breast density evaluation in cone beam breast CT

    Science.gov (United States)

    Zhang, Xiaohua; Ning, Ruola

    2011-03-01

    Cone Beam Breast CT is a three-dimensional breast imaging modality with high contrast resolution and no tissue overlap. With these advantages, it is possible to measure volumetric breast density accurately and quantitatively with CBBCT 3D images. Three major breast components need to be segmented: skin, fat and glandular tissue. In this research, a modified morphological processing is applied to the CBBCT images to detect and remove the skin of the breast. After the skin is removed, a 2-step fuzzy clustering scheme is applied to the CBBCT image volume to adaptively cluster the image voxels into fat and glandular tissue areas based on the intensity of each voxel. Finally, the CBBCT breast volume images are divided into three categories: skin, fat and glands. Clinical data is used and the quantitative CBBCT breast density evaluation results are compared with the mammogram-based BIRADS breast density categories.

  10. CRALBP supports the mammalian retinal visual cycle and cone vision.

    Science.gov (United States)

    Xue, Yunlu; Shen, Susan Q; Jui, Jonathan; Rupp, Alan C; Byrne, Leah C; Hattar, Samer; Flannery, John G; Corbo, Joseph C; Kefalov, Vladimir J

    2015-02-01

    Mutations in the cellular retinaldehyde-binding protein (CRALBP, encoded by RLBP1) can lead to severe cone photoreceptor-mediated vision loss in patients. It is not known how CRALBP supports cone function or how altered CRALBP leads to cone dysfunction. Here, we determined that deletion of Rlbp1 in mice impairs the retinal visual cycle. Mice lacking CRALBP exhibited M-opsin mislocalization, M-cone loss, and impaired cone-driven visual behavior and light responses. Additionally, M-cone dark adaptation was largely suppressed in CRALBP-deficient animals. While rearing CRALBP-deficient mice in the dark prevented the deterioration of cone function, it did not rescue cone dark adaptation. Adeno-associated virus-mediated restoration of CRALBP expression specifically in Müller cells, but not retinal pigment epithelial (RPE) cells, rescued the retinal visual cycle and M-cone sensitivity in knockout mice. Our results identify Müller cell CRALBP as a key component of the retinal visual cycle and demonstrate that this pathway is important for maintaining normal cone-driven vision and accelerating cone dark adaptation.

  11. Micro focusing of fast electrons with opened cone targets

    International Nuclear Information System (INIS)

    Liu Feng; Liu Xiaoxuan; Ding Wenjun; Du Fei; Li Yutong; Ma Jinglong; Liu Xiaolong; Chen Liming; Lu Xin; Dong Quanli; Wang Weimin; Wang Zhaohua; Wei Zhiyi; Liu Bicheng; Sheng Zhengming; Zhang Jie

    2012-01-01

    Using opened reentrant cone silicon targets, we have demonstrated the effect of micro focusing of fast electrons generated in intense laser-plasma interactions. When an intense femtosecond laser pulse is focused tightly onto one of the side walls of the cone, fast electron beam emitted along the side wall is observed. When a line focus spot, which is long enough to irradiate both of the side walls of the cone simultaneously, is used, two electron beams emitted along each side wall, respectively, are observed. The two beams should cross each other near the open tip of the cone, resulting in micro focusing. We use a two-dimensional Particle-In-Cell code to simulate the electron emission both in opened and closed cone targets. The simulation results of the opened cone targets are in agreement with the experimental observation while the results of the closed cone targets do not show the micro focusing effect.

  12. Micro-motion Recognition of Spatial Cone Target Based on ISAR Image Sequences

    Directory of Open Access Journals (Sweden)

    Changyong Shu

    2016-04-01

    Full Text Available The accurate micro-motions recognition of spatial cone target is the foundation of the characteristic parameter acquisition. For this reason, a micro-motion recognition method based on the distinguishing characteristics extracted from the Inverse Synthetic Aperture Radar (ISAR sequences is proposed in this paper. The projection trajectory formula of cone node strong scattering source and cone bottom slip-type strong scattering sources, which are located on the spatial cone target, are deduced under three micro-motion types including nutation, precession, and spinning, and the correctness is verified by the electromagnetic simulation. By comparison, differences are found among the projection of the scattering sources with different micro-motions, the coordinate information of the scattering sources in the Inverse Synthetic Aperture Radar sequences is extracted by the CLEAN algorithm, and the spinning is recognized by setting the threshold value of Doppler. The double observation points Interacting Multiple Model Kalman Filter is used to separate the scattering sources projection of the nutation target or precession target, and the cross point number of each scattering source’s projection track is used to classify the nutation or precession. Finally, the electromagnetic simulation data are used to verify the effectiveness of the micro-motion recognition method.

  13. Point spread function modeling and image restoration for cone-beam CT

    International Nuclear Information System (INIS)

    Zhang Hua; Shi Yikai; Huang Kuidong; Xu Zhe

    2015-01-01

    X-ray cone-beam computed tomography (CT) has such notable features as high efficiency and precision, and is widely used in the fields of medical imaging and industrial non-destructive testing, but the inherent imaging degradation reduces the quality of CT images. Aimed at the problems of projection image degradation and restoration in cone-beam CT, a point spread function (PSF) modeling method is proposed first. The general PSF model of cone-beam CT is established, and based on it, the PSF under arbitrary scanning conditions can be calculated directly for projection image restoration without the additional measurement, which greatly improved the application convenience of cone-beam CT. Secondly, a projection image restoration algorithm based on pre-filtering and pre-segmentation is proposed, which can make the edge contours in projection images and slice images clearer after restoration, and control the noise in the equivalent level to the original images. Finally, the experiments verified the feasibility and effectiveness of the proposed methods. (authors)

  14. On Krasnoselskii's Cone Fixed Point Theorem

    Directory of Open Access Journals (Sweden)

    Man Kam Kwong

    2008-04-01

    Full Text Available In recent years, the Krasnoselskii fixed point theorem for cone maps and its many generalizations have been successfully applied to establish the existence of multiple solutions in the study of boundary value problems of various types. In the first part of this paper, we revisit the Krasnoselskii theorem, in a more topological perspective, and show that it can be deduced in an elementary way from the classical Brouwer-Schauder theorem. This viewpoint also leads to a topology-theoretic generalization of the theorem. In the second part of the paper, we extend the cone theorem in a different direction using the notion of retraction and show that a stronger form of the often cited Leggett-Williams theorem is a special case of this extension.

  15. Basic principle of cone beam computed tomography

    International Nuclear Information System (INIS)

    Choi, Yong Suk; Kim, Gyu Tae; Hwang, Eui Hwan

    2006-01-01

    The use of computed tomography for dental procedures has increased recently. Cone beam computed tomography(CBCT) systems have been designed for imaging hard tissues of the dentomaxillofacial region. CBCT is capable of providing high resolution in images of high diagnostic quality. This technology allows for 3-dimensional representation of the dentomaxillofacial skeleton with minimal distortion, but at lower equipment cost, simpler image acquisition and lower patient dose. Because this technology produces images with isotropic sub-millimeter spatial resolution, it is ideally suited for dedicated dentomaxillofacial imaging. In this paper, we provide a brief overview of cone beam scanning technology and compare it with the fan beam scanning used in conventional CT and the basic principles of currently available CBCT systems

  16. Variability of silver fir (Abies alba Mill. cones – variability of cone parameters

    Directory of Open Access Journals (Sweden)

    Aniszewska Monika

    2016-09-01

    Full Text Available This study aimed at determining the shape of closed silver fir cones from the Jawor Forest District (Wroclaw, based purely on measurements of their length and thickness. Using these two parameters, the most accurate estimations were achieved with a fourth-degree polynomial fitting function. We then calculated the cones’ surface area and volume in three different ways: 1 Using the fourth-degree polynomial shape estimation, 2 Introducing indicators of compliance (k1, k2, k3 to calculate the volume and then comparing it to its actual value as measured in a pitcher filled with water, 3 Comparing the surface area of the cones as calculated with the polynomial function to the value obtained from ratios of indicators of compliance (ratios k4 and k5. We found that the calculated surface area and volume were substantially higher than the corresponding measured values. Test values of cone volume and surface area as calculated by our model were 8% and 5% lower, respectively, compared to direct measurements. We also determined the fir cones apparent density to be 0.8 g·cm-3on average. The gathered data on cone surface area, volume and bulk density is a valuable tool for optimizing the thermal peeling process in mill cabinets to acquire high quality seeds.

  17. The NLO jet vertex in the small-cone approximation for kt and cone algorithms

    Energy Technology Data Exchange (ETDEWEB)

    Colferai, D.; Niccoli, A. [Dipartimento di Fisica e Astronomia, Università di Firenze and INFN, Sezione di Firenze, 50019 Sesto Fiorentino (Italy)

    2015-04-15

    We determine the jet vertex for Mueller-Navelet jets and forward jets in the small-cone approximation for two particular choices of jet algoritms: the kt algorithm and the cone algorithm. These choices are motivated by the extensive use of such algorithms in the phenomenology of jets. The differences with the original calculations of the small-cone jet vertex by Ivanov and Papa, which is found to be equivalent to a formerly algorithm proposed by Furman, are shown at both analytic and numerical level, and turn out to be sizeable. A detailed numerical study of the error introduced by the small-cone approximation is also presented, for various observables of phenomenological interest. For values of the jet “radius” R=0.5, the use of the small-cone approximation amounts to an error of about 5% at the level of cross section, while it reduces to less than 2% for ratios of distributions such as those involved in the measure of the azimuthal decorrelation of dijets.

  18. The NLO jet vertex in the small-cone approximation for kt and cone algorithms

    International Nuclear Information System (INIS)

    Colferai, D.; Niccoli, A.

    2015-01-01

    We determine the jet vertex for Mueller-Navelet jets and forward jets in the small-cone approximation for two particular choices of jet algoritms: the kt algorithm and the cone algorithm. These choices are motivated by the extensive use of such algorithms in the phenomenology of jets. The differences with the original calculations of the small-cone jet vertex by Ivanov and Papa, which is found to be equivalent to a formerly algorithm proposed by Furman, are shown at both analytic and numerical level, and turn out to be sizeable. A detailed numerical study of the error introduced by the small-cone approximation is also presented, for various observables of phenomenological interest. For values of the jet “radius” R=0.5, the use of the small-cone approximation amounts to an error of about 5% at the level of cross section, while it reduces to less than 2% for ratios of distributions such as those involved in the measure of the azimuthal decorrelation of dijets.

  19. Hadronic wavefunctions in light-cone quantization

    International Nuclear Information System (INIS)

    Hyer, T.

    1994-05-01

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

  20. Lessons from the light-cone box

    CERN Document Server

    Leibbrandt, G

    2000-01-01

    Working in the noncovariant light-cone gauge, we discuss the explicit computation of the 1PI four-point function ("box diagram") in Yang- Mills theory. The complete box diagram which consists of 16 box subdiagrams, 8 lynx subdiagrams and 4 fish subdiagrams, yields both local and nonlocal UV divergent terms. The nonlocal terms are consistent with gauge symmetry and correspond to a nonlocal renormalization of the wave function. (14 refs).

  1. Instantons on Calabi-Yau cones

    Science.gov (United States)

    Sperling, Marcus

    2015-12-01

    The Hermitian Yang-Mills equations on certain vector bundles over Calabi-Yau cones can be reduced to a set of matrix equations; in fact, these are Nahm-type equations. The latter can be analysed further by generalising arguments of Donaldson and Kronheimer used in the study of the original Nahm equations. Starting from certain equivariant connections, we show that the full set of instanton equations reduce, with a unique gauge transformation, to the holomorphicity condition alone.

  2. Variation among individuals in cone production in Pinus palustris (Pinaceae).

    Science.gov (United States)

    Haymes, Kelly L; Fox, Gordon A

    2012-04-01

    Reproductive output varies considerably among individuals within plant populations, and this is especially so in cone production of conifers. While this variation can have substantial effects on populations, little is known about its magnitude or causes. We studied variation in cone production for 2 years within a population of Pinus palustris Mill. (longleaf pine; Pinaceae). Using hurdle models, we evaluated the importance of burn treatments, tree size (dbh), canopy status (open, dominant, subordinate), and number of conspecific neighbors within 4 m (N(4)). Cone production of individuals-even after accounting for other variables-was strongly correlated between years. Trees in plots burned every 1, 2, or 5 years produced more cones than those burned every 7 years, or unburned. Larger trees tend to produce more cones, but the large effects of the other factors studied caused substantial scatter in the dbh-cone number relationship. Among trees in the open, dbh had little explanatory power. Subordinate trees with three neighbors produced no cones. Tree size alone was a weak predictor of cone production. Interactions with neighbors play an important role in generating reproductive heterogeneity, and must be accounted for when relating cone production to size. The strong between-year correlation, together with the large variance in cone production among trees without neighbors, suggests that still more of the variance may be explainable, but requires factors outside of our study.

  3. What has driven the evolution of multiple cone classes in visual systems: object contrast enhancement or light flicker elimination?

    Science.gov (United States)

    Sabbah, Shai; Hawryshyn, Craig W

    2013-07-04

    Two competing theories have been advanced to explain the evolution of multiple cone classes in vertebrate eyes. These two theories have important, but different, implications for our understanding of the design and tuning of vertebrate visual systems. The 'contrast theory' proposes that multiple cone classes evolved in shallow-water fish to maximize the visual contrast of objects against diverse backgrounds. The competing 'flicker theory' states that multiple cone classes evolved to eliminate the light flicker inherent in shallow-water environments through antagonistic neural interactions, thereby enhancing object detection. However, the selective pressures that have driven the evolution of multiple cone classes remain largely obscure. We show that two critical assumptions of the flicker theory are violated. We found that the amplitude and temporal frequency of flicker vary over the visible spectrum, precluding its cancellation by simple antagonistic interactions between the output signals of cones. Moreover, we found that the temporal frequency of flicker matches the frequency where sensitivity is maximal in a wide range of fish taxa, suggesting that the flicker may actually enhance the detection of objects. Finally, using modeling of the chromatic contrast between fish pattern and background under flickering illumination, we found that the spectral sensitivity of cones in a cichlid focal species is optimally tuned to maximize the visual contrast between fish pattern and background, instead of to produce a flicker-free visual signal. The violation of its two critical assumptions substantially undermines support for the flicker theory as originally formulated. While this alone does not support the contrast theory, comparison of the contrast and flicker theories revealed that the visual system of our focal species was tuned as predicted by the contrast theory rather than by the flicker theory (or by some combination of the two). Thus, these findings challenge key

  4. Examination of gutta-percha cones for microbial contamination during chemical use

    Directory of Open Access Journals (Sweden)

    Guven Kayaoglu

    2009-06-01

    Full Text Available OBJECTIVE: The aim of this study was to evaluate the degree of microbial contamination in packaged gutta-percha cones before and during use in clinical conditions. MATERIAL AND METHODS: Sealed packages of #15-40 gutta-percha cones were opened under aseptic laboratory conditions. Two gutta-percha cones from each size were randomly drawn and added to tubes containing glass beads and 750 µL of saline. The tubes were vortexed, serially diluted and samples of 250 µL were cultured on agar plates. The plates were incubated at 37ºC for 3 days and colonies were counted. The initially sampled packages were distributed to 12 final year dental students. The packages were collected at the end of the first and the third clinical practice days and sampled as described above. RESULTS: Baseline microbial counts did not exceed 3 CFU. At the end of the first and the third day, additional contamination was found in five and three of the packages, respectively. The ratio of contaminated packages at the first day and the third day was not significantly different (z-test; p > 0.05. The numbers of microorganisms cultured at the first day (8 ± 9.9 CFU and the third day (4.5 ± 8.3 CFU were not significantly different (Wilcoxon signed-rank test; p > 0.05. No significant correlation was found between the number of filled root canals and cultured microorganisms at either the first day (Spearman's rho; r = 0.481, p = 0.113 or the third day (r = -0.034, p = 0.917. CONCLUSIONS: Gutta-percha cones taken directly from manufacturer's sealed package harbored microorganisms. Clinical use of the packages has been found to be associated with additional contamination of the gutta-percha cones. The counts of cultured microorganisms did not correlate well with the number of filled root canals.

  5. Polymer-Enhanced Subsurface Delivery and Distribution of Permanganate

    Science.gov (United States)

    2013-02-01

    capacity CPT Cone penetrometer test CSM Conceptual site model CSP Certified safety professional CVOC Chlorinated volatile organic compound c.y...in the test area was further investigated during site characterization activities conducted in Nov and Dec 2009. Cone penetrometer testing (CPT) was...Aboveground storage tank bgs Below ground surface CDISCO Conceptual design for ISCO (modeling tool) COC Contaminant of Concern CPT Cone penetrometer test

  6. Noise simulation in cone beam CT imaging with parallel computing

    International Nuclear Information System (INIS)

    Tu, S.-J.; Shaw, Chris C; Chen, Lingyun

    2006-01-01

    We developed a computer noise simulation model for cone beam computed tomography imaging using a general purpose PC cluster. This model uses a mono-energetic x-ray approximation and allows us to investigate three primary performance components, specifically quantum noise, detector blurring and additive system noise. A parallel random number generator based on the Weyl sequence was implemented in the noise simulation and a visualization technique was accordingly developed to validate the quality of the parallel random number generator. In our computer simulation model, three-dimensional (3D) phantoms were mathematically modelled and used to create 450 analytical projections, which were then sampled into digital image data. Quantum noise was simulated and added to the analytical projection image data, which were then filtered to incorporate flat panel detector blurring. Additive system noise was generated and added to form the final projection images. The Feldkamp algorithm was implemented and used to reconstruct the 3D images of the phantoms. A 24 dual-Xeon PC cluster was used to compute the projections and reconstructed images in parallel with each CPU processing 10 projection views for a total of 450 views. Based on this computer simulation system, simulated cone beam CT images were generated for various phantoms and technique settings. Noise power spectra for the flat panel x-ray detector and reconstructed images were then computed to characterize the noise properties. As an example among the potential applications of our noise simulation model, we showed that images of low contrast objects can be produced and used for image quality evaluation

  7. Contributions of Rod and Cone Pathways to Retinal Direction Selectivity Through Development.

    Science.gov (United States)

    Rosa, Juliana M; Morrie, Ryan D; Baertsch, Hans C; Feller, Marla B

    2016-09-14

    Direction selectivity is a robust computation across a broad stimulus space that is mediated by activity of both rod and cone photoreceptors through the ON and OFF pathways. However, rods, S-cones, and M-cones activate the ON and OFF circuits via distinct pathways and the relative contribution of each to direction selectivity is unknown. Using a variety of stimulation paradigms, pharmacological agents, and knockout mice that lack rod transduction, we found that inputs from the ON pathway were critical for strong direction-selective (DS) tuning in the OFF pathway. For UV light stimulation, the ON pathway inputs to the OFF pathway originated with rod signaling, whereas for visible stimulation, the ON pathway inputs to the OFF pathway originated with both rod and M-cone signaling. Whole-cell voltage-clamp recordings revealed that blocking the ON pathway reduced directional tuning in the OFF pathway via a reduction in null-side inhibition, which is provided by OFF starburst amacrine cells (SACs). Consistent with this, our recordings from OFF SACs confirmed that signals originating in the ON pathway contribute to their excitation. Finally, we observed that, for UV stimulation, ON contributions to OFF DS tuning matured earlier than direct signaling via the OFF pathway. These data indicate that the retina uses multiple strategies for computing DS responses across different colors and stages of development. The retina uses parallel pathways to encode different features of the visual scene. In some cases, these distinct pathways converge on circuits that mediate a distinct computation. For example, rod and cone pathways enable direction-selective (DS) ganglion cells to encode motion over a wide range of light intensities. Here, we show that although direction selectivity is robust across light intensities, motion discrimination for OFF signals is dependent upon ON signaling. At eye opening, ON directional tuning is mature, whereas OFF DS tuning is significantly reduced due

  8. Pulsar average waveforms and hollow cone beam models

    Science.gov (United States)

    Backer, D. C.

    1975-01-01

    An analysis of pulsar average waveforms at radio frequencies from 40 MHz to 15 GHz is presented. The analysis is based on the hypothesis that the observer sees one cut of a hollow-cone beam pattern and that stationary properties of the emission vary over the cone. The distributions of apparent cone widths for different observed forms of the average pulse profiles (single, double/unresolved, double/resolved, triple and multiple) are in modest agreement with a model of a circular hollow-cone beam with random observer-spin axis orientation, a random cone axis-spin axis alignment, and a small range of physical hollow-cone parameters for all objects.

  9. Techniques for optimizing nanotips derived from frozen taylor cones

    Science.gov (United States)

    Hirsch, Gregory

    2017-12-05

    Optimization techniques are disclosed for producing sharp and stable tips/nanotips relying on liquid Taylor cones created from electrically conductive materials with high melting points. A wire substrate of such a material with a preform end in the shape of a regular or concave cone, is first melted with a focused laser beam. Under the influence of a high positive potential, a Taylor cone in a liquid/molten state is formed at that end. The cone is then quenched upon cessation of the laser power, thus freezing the Taylor cone. The tip of the frozen Taylor cone is reheated by the laser to allow its precise localized melting and shaping. Tips thus obtained yield desirable end-forms suitable as electron field emission sources for a variety of applications. In-situ regeneration of the tip is readily accomplished. These tips can also be employed as regenerable bright ion sources using field ionization/desorption of introduced chemical species.

  10. The light-cone gauge in Polyakov's theory of strings and its relation to the conformal gauge

    International Nuclear Information System (INIS)

    Tzani, R.

    1989-01-01

    The author studies the string theory as a gauge theory. The analysis includes the formulation of the interacting bosonic string by fixing the Gervais-Sakita light-cone gauge in Polyakov's path-integral formulation of the theory and the study of the problem of changing gauge in string theory in the context of the functional formulation of the theory. The main results are the following: Mandelstam's picture is obtained from the light-cone gauge fixed Polyakov's theory. Due to the off-diagonal nature of the gauge, the calculation of the determinants differs from the usual (conformal gauge) case. The regularization of the functional integrals associated with these determinants is done by using the conformal-invariance principle. He then shows that the conformal anomaly associated with this new gauge fixing is canceled at dimensions of space-time d = 26. Studying the problem of changing gauge in string theory, he shows the equivalence between the light-cone and conformal gauge in the path-integral formulation of the theory. In particular, by performing a proper change of variables in the commuting and ghost fields in the Polyakov path-integral, the string theory in the conformal gauge is obtained from the light-cone gauge fixed expression. Finally, the problem of changing gauge is generalized to the higher genus surfaces. It is shown that the string theory in the conformal gauge is equivalent to the light-cone gauge fixed theory for surface with arbitrary number of handles

  11. Closed graph and open mapping theorems for normed cones

    Indian Academy of Sciences (India)

    Abstract. A quasi-normed cone is a pair (X, p) such that X is a (not necessarily cancellative) cone and q is a quasi-norm on X. The aim of this paper is to prove a closed graph and an open mapping type theorem for quasi-normed cones. This is done with the help of appropriate notions of completeness, continuity and ...

  12. Bat eyes have ultraviolet-sensitive cone photoreceptors.

    Directory of Open Access Journals (Sweden)

    Brigitte Müller

    Full Text Available Mammalian retinae have rod photoreceptors for night vision and cone photoreceptors for daylight and colour vision. For colour discrimination, most mammals possess two cone populations with two visual pigments (opsins that have absorption maxima at short wavelengths (blue or ultraviolet light and long wavelengths (green or red light. Microchiropteran bats, which use echolocation to navigate and forage in complete darkness, have long been considered to have pure rod retinae. Here we use opsin immunohistochemistry to show that two phyllostomid microbats, Glossophaga soricina and Carollia perspicillata, possess a significant population of cones and express two cone opsins, a shortwave-sensitive (S opsin and a longwave-sensitive (L opsin. A substantial population of cones expresses S opsin exclusively, whereas the other cones mostly coexpress L and S opsin. S opsin gene analysis suggests ultraviolet (UV, wavelengths <400 nm sensitivity, and corneal electroretinogram recordings reveal an elevated sensitivity to UV light which is mediated by an S cone visual pigment. Therefore bats have retained the ancestral UV tuning of the S cone pigment. We conclude that bats have the prerequisite for daylight vision, dichromatic colour vision, and UV vision. For bats, the UV-sensitive cones may be advantageous for visual orientation at twilight, predator avoidance, and detection of UV-reflecting flowers for those that feed on nectar.

  13. Cone formation on copper by ion-beam sputtering

    International Nuclear Information System (INIS)

    Den, A.K.; Ghose, D.

    1991-01-01

    The phenomenon of cone formation on solid surfaces by ion-beam sputtering has been the subject of extensive studies in recent years. The reason for this is that not only do such studies provide a better understanding of the physical processes underlying the cone formation, they also show the importance and relevance of ion-induced textured surfaces in different technologies and experimental techniques. Usually cones are formed by impurity contamination of the target surface during sputtering. In the absence of impurities, a particular target crystallography can result in a high density of cone formation. In the present work the formation and morphologies of cones were studied on a Cu substrate by seeding W-impurities during Kr + -ion sputtering. The results showed that the surface was eroded unevenly and several regions of densely populated cones were formed. The simultaneous appearance of short and tall cones apparently supports both the left-standing and the growth models of cone formation. The cone apex angle was measured and also theoretically predicted. The discrepancy between the two values is possibly due to the neglect of so-called secondary effects. (author)

  14. Chloride currents in cones modify feedback from horizontal cells to cones in goldfish retina

    NARCIS (Netherlands)

    Endeman, Duco; Fahrenfort, Iris; Sjoerdsma, Trijntje; Steijaert, Marvin; ten Eikelder, Huub; Kamermans, Maarten

    2012-01-01

    In neuronal systems, excitation and inhibition must be well balanced to ensure reliable information transfer. The cone/horizontal cell (HC) interaction in the retina is an example of this. Because natural scenes encompass an enormous intensity range both in temporal and spatial domains, the balance

  15. Revisit of combined parallel-beam/cone-beam or fan-beam/cone-beam imaging.

    Science.gov (United States)

    Zeng, Gengsheng L

    2013-10-01

    This aim of this paper is to revisit the parallel-beam/cone-beam or fan-beam/cone-beam imaging configuration, and to investigate whether this configuration has any advantages. Twenty years ago, it was suggested to simultaneously use a parallel-beam (or a fan-beam) collimator and a cone-beam collimator to acquire single photon emission computed tomography data. The motivation was that the parallel-beam (or the fan-beam) collimator can provide sufficient sampling, while the cone-beam collimator is able to provide higher photon counts. Even with higher total counts, this hybrid system does not give significant improvement (if any) in terms of image noise and artifacts reduction. If a conventional iterative maximum-likelihood expectation-maximization algorithm is used to reconstruct the image, the resultant reconstruction may be worse than the parallel-beam-only (or fan-beam-only) system. This paper uses the singular value decomposition (SVD) analysis to explain this phenomenon. The SVD results indicate that the parallel-beam-only and the fan-beam-only system outperform the combined systems. The optimal imaging system does not necessary to be the one that generates the projections with highest signal-to-noise ratio and best resolution.

  16. Mach cone in a shallow granular fluid

    International Nuclear Information System (INIS)

    Heil, Patrick; Rericha, E. C.; Goldman, Daniel I.; Swinney, Harry L.

    2004-01-01

    We study the V-shaped wake (Mach cone) formed by a cylindrical rod moving through a thin, vertically vibrated granular layer. The wake, analogous to a shock (hydraulic jump) in shallow water, appears for rod velocities v R greater than a critical velocity c. We measure the half angle θ of the wake as a function of v R and layer depth h. The angle satisfies the Mach relation, sin θ=c/v R , where c=√(gh), even for h as small as one-particle diameter

  17. Integrity of the cone photoreceptor mosaic in oligocone trichromacy

    DEFF Research Database (Denmark)

    Michaelides, Michel; Rha, Jungtae; Dees, Elise W

    2011-01-01

    Oligocone trichromacy (OT) is an unusual cone dysfunction syndrome characterized by reduced visual acuity, mild photophobia, reduced amplitude of the cone electroretinogram with normal rod responses, normal fundus appearance, and normal or near-normal color vision. It has been proposed that these...

  18. Scoria Cone Construction Mechanism, Lathrop Wells Volcano, Southern Nevada

    Energy Technology Data Exchange (ETDEWEB)

    G. Valentine; D. Krier; F. Perry; G. Heiken

    2005-01-18

    Scoria cones are commonly assumed to have been constructed by the accumulation of ballistically-ejected clasts from discrete and relatively coarse-grained Strombolian bursts and subsequent avalanching such that the cone slopes are at or near the angle of repose for loose scoria. The cone at the hawaiitic Lathrop Wells volcano, southern Nevada, contains deposits that are consistent with the above processes during early cone-building phases; these early deposits are composed mainly of coarse lapilli and fluidal bombs and are partially welded, indicating relatively little cooling during flight. However, the bulk of the cone is comprised of relatively fine-grained (ash and lapilli), planar beds with no welding, even within a few tens of meters of the vent. This facies is consistent with deposition by direct fallout from sustained eruption columns of relatively well-fragmented material, primarily mantling cone slopes and with a lesser degree of avalanching than is commonly assumed. A laterally extensive fallout deposit (up to 20 km from the vent) is inferred to have formed contemporaneously with these later cone deposits. This additional mechanism for construction of scoria cones may also be important at other locations, particularly where the magmas are relatively high in volatile content and where conditions promote the formation of abundant microlites in the rising mafic magma.

  19. Gene therapy rescues cone function in congenital achromatopsia.

    Science.gov (United States)

    Komáromy, András M; Alexander, John J; Rowlan, Jessica S; Garcia, Monique M; Chiodo, Vince A; Kaya, Asli; Tanaka, Jacqueline C; Acland, Gregory M; Hauswirth, William W; Aguirre, Gustavo D

    2010-07-01

    The successful restoration of visual function with recombinant adeno-associated virus (rAAV)-mediated gene replacement therapy in animals and humans with an inherited disease of the retinal pigment epithelium has ushered in a new era of retinal therapeutics. For many retinal disorders, however, targeting of therapeutic vectors to mutant rods and/or cones will be required. In this study, the primary cone photoreceptor disorder achromatopsia served as the ideal translational model to develop gene therapy directed to cone photoreceptors. We demonstrate that rAAV-mediated gene replacement therapy with different forms of the human red cone opsin promoter led to the restoration of cone function and day vision in two canine models of CNGB3 achromatopsia, a neuronal channelopathy that is the most common form of achromatopsia in man. The robustness and stability of the observed treatment effect was mutation independent, but promoter and age dependent. Subretinal administration of rAAV5-hCNGB3 with a long version of the red cone opsin promoter in younger animals led to a stable therapeutic effect for at least 33 months. Our results hold promise for future clinical trials of cone-directed gene therapy in achromatopsia and other cone-specific disorders.

  20. Insectos de cones y semillas de las coniferas de Mexico

    Science.gov (United States)

    David Cibrián-Tovar; Bernard H. Ebel; Harry O. Yates; José Tulio Mhdez-Montiel

    1986-01-01

    The hosts, description, damage, life cycle, habits, and importance of 54 known cone and seed destroying insects attacking Mexican conifer trees are discussed. Distribution maps and color photos are provided. New species described are three species of Cydia (seedworm), four species of Dioryctria (coneworm), and four species of cone...

  1. Polynomial Primal-Dual Cone Affine Scaling for Semidefinite Programming

    NARCIS (Netherlands)

    A.B. Berkelaar (Arjan); J.F. Sturm; S. Zhang (Shuzhong)

    1996-01-01

    textabstractIn this paper we generalize the primal--dual cone affine scaling algorithm of Sturm and Zhang to semidefinite programming. We show in this paper that the underlying ideas of the cone affine scaling algorithm can be naturely applied to semidefinite programming, resulting in a new

  2. Scatter corrections for cone beam optical CT

    Energy Technology Data Exchange (ETDEWEB)

    Olding, Tim; Holmes, Oliver [Department of Physics, Queen' s University (United Kingdom); Schreiner, L John [Medical Physics Department, Cancer Centre of Southeastern Ontario (Canada)], E-mail: Tim.Olding@krcc.on.ca

    2009-05-01

    Cone beam optical computed tomography (OptCT) employing the VISTA scanner (Modus Medical, London, ON) has been shown to have significant promise for fast, three dimensional imaging of polymer gel dosimeters. One distinct challenge with this approach arises from the combination of the cone beam geometry, a diffuse light source, and the scattering polymer gel media, which all contribute scatter signal that perturbs the accuracy of the scanner. Beam stop array (BSA), beam pass array (BPA) and anti-scatter polarizer correction methodologies have been employed to remove scatter signal from OptCT data. These approaches are investigated through the use of well-characterized phantom scattering solutions and irradiated polymer gel dosimeters. BSA corrected scatter solutions show good agreement in attenuation coefficient with the optically absorbing dye solutions, with considerable reduction of scatter-induced cupping artifact at high scattering concentrations. The application of BSA scatter corrections to a polymer gel dosimeter lead to an overall improvement in the number of pixel satisfying the (3%, 3mm) gamma value criteria from 7.8% to 0.15%.

  3. Optical coherence tomography in progressive cone dystrophy.

    Science.gov (United States)

    Zahlava, Jiri; Lestak, Jan; Karel, Ivan

    2014-12-01

    The aim of the study was to analyse different clinical pictures in patients with progressive cone dystrophy (PCD), to compare these with the results of optical coherence tomography (OCT) and to evaluate the benefits of this method for diagnosis. The group consisted of 16 patients (32 eyes) with PCD. All patients were examined for visual acuity, colour sense and visual field. We performed biomicroscopic examination, photo-documentation, fluorescein angiography, electrophysiological tests and OCT. Using biomicroscopy and fluorescein angiography, we found changes in the retinal pigment epithelium ranging from barely detectable changes up to the typical bull's eye appearance. In all the eyes, OCT established statistically significant reduction in the thickness and structural changes in the neuroretina of the macula. Atrophy was evident especially in the outer nuclear layer, in the photoreceptor inner segment/outer segment junction and in the retinal pigment epithelium. Visual acuity was mainly dependent on the degree to which the continuity of the photoreceptor inner segment/outer segment junction layer was maintained. Eyes with better preserved neuroretinal structure in the fovea centralis had generally less reduced thickness of the retina and a better visual acuity. OCT specifies the quantitative and qualitative changes in the macula and may contribute significantly to the diagnosis of the progressive cone dystrophy, particularly in the early stages of the disease which is difficult to diagnose.

  4. O grande manancial do Cone Sul

    Directory of Open Access Journals (Sweden)

    Gerôncio Albuquerque Rocha

    1997-08-01

    Full Text Available O Cone Sul abriga um manancial de águas subterrâneas de extensão continental, denominado Aqüífero Guarani, cujo volume de água doce disponível é suficiente para abastecer permanentemente os 15 milhões de habitantes de sua região de ocorrência. Neste trabalho é feita uma descrição sumária do reservatório. São estabelecidas bases para o aproveitamento dos recursos hídricos e propostos mecanismos e arranjos institucionais, em âmbito internacional, com vistas a iniciar um processo participativo de gestão do manancial.The South Cone bears a groundwater source of continental extent called Guarani Aquifer, in which the volume of freshwater available is sufficient to supply the 15 million inhabitants of the region. The present paper gives a briefing on this reservoir, establishes the basis for the good use of the water resources, as well as proposes institutional means and arrangements at international level with a view to initiating a joint process to manage the source.

  5. Cones in the Euclidean space with vanishing scalar curvature

    Directory of Open Access Journals (Sweden)

    João Lucas M. Barbosa

    2004-12-01

    Full Text Available Given a hypersurface M on a unit sphere of the Euclidean space, we define the cone based on M as the set of half-lines issuing from the origin and passing through M. By assuming that the scalar curvature of the cone vanishes, we obtain conditions under which bounded domains of such cone are stable or unstable.Dada uma hipersuperfície M de uma esfera unitária do espaço euclidiano, definimos o cone sobre M como o conjunto das semi-retas que saem da origem e passam por M. Admitindo que a curvatura escalar de um dado cone é nula, estabelecemos condições para que os seus domínios limitados sejam estáveis ou instáveis.

  6. Unsupervised learning of cone spectral classes from natural images.

    Science.gov (United States)

    Benson, Noah C; Manning, Jeremy R; Brainard, David H

    2014-06-01

    The first step in the evolution of primate trichromatic color vision was the expression of a third cone class not present in ancestral mammals. This observation motivates a fundamental question about the evolution of any sensory system: how is it possible to detect and exploit the presence of a novel sensory class? We explore this question in the context of primate color vision. We present an unsupervised learning algorithm capable of both detecting the number of spectral cone classes in a retinal mosaic and learning the class of each cone using the inter-cone correlations obtained in response to natural image input. The algorithm's ability to classify cones is in broad agreement with experimental evidence about functional color vision for a wide range of mosaic parameters, including those characterizing dichromacy, typical trichromacy, anomalous trichromacy, and possible tetrachromacy.

  7. Unsupervised learning of cone spectral classes from natural images.

    Directory of Open Access Journals (Sweden)

    Noah C Benson

    2014-06-01

    Full Text Available The first step in the evolution of primate trichromatic color vision was the expression of a third cone class not present in ancestral mammals. This observation motivates a fundamental question about the evolution of any sensory system: how is it possible to detect and exploit the presence of a novel sensory class? We explore this question in the context of primate color vision. We present an unsupervised learning algorithm capable of both detecting the number of spectral cone classes in a retinal mosaic and learning the class of each cone using the inter-cone correlations obtained in response to natural image input. The algorithm's ability to classify cones is in broad agreement with experimental evidence about functional color vision for a wide range of mosaic parameters, including those characterizing dichromacy, typical trichromacy, anomalous trichromacy, and possible tetrachromacy.

  8. A free boundary problem on three-dimensional cones

    Science.gov (United States)

    Allen, Mark

    2017-12-01

    We consider a free boundary problem on cones depending on a parameter c and study when the free boundary is allowed to pass through the vertex of the cone. We show that when the cone is three-dimensional and c is large enough, the free boundary avoids the vertex. We also show that when c is small enough but still positive, the free boundary is allowed to pass through the vertex. This establishes 3 as the critical dimension for which the free boundary may pass through the vertex of a right circular cone. In view of the well-known connection between area-minimizing surfaces and the free boundary problem under consideration, our result is analogous to a result of Morgan that classifies when an area-minimizing surface on a cone passes through the vertex.

  9. Formation of shatter cones in MEMIN impact experiments

    Science.gov (United States)

    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.

  10. Seed cone anatomy of Cheirolepidiaceae (Coniferales): reinterpreting Pararaucaria patagonica Wieland.

    Science.gov (United States)

    Escapa, Ignacio H; Rothwell, Gar W; Stockey, Ruth A; Cúneo, N Rubén

    2012-06-01

    Seed cone morphology and anatomy reflect some of the most important changes in the phylogeny and evolutionary biology of conifers. Reexamination of the enigmatic Jurassic seed cone Pararaucaria patagonica reveals previously unknown systematically informative characters that demonstrate affinities with the Cheirolepidiaceae. This paper documents, for the first time, internal anatomy for seed cones of this important extinct Mesozoic conifer family, which may represent the ghost lineage leading to modern Pinaceae. Morphology and anatomy of cones from the Jurassic La Matilde Formation in Patagonia are described from a combination of polished wafers and thin section preparations. New photographic techniques are employed to reveal histological details of thin sections in which organic cell wall remains are not preserved. Specific terminology for conifer seed cones is proposed to help clarify hypotheses of homology for the various structures of the cones. Specimens are demonstrated to have trilobed ovuliferous scale tips along with a seed enclosing pocket of ovuliferous scale tissue. Originally thought to represent a seed wing in P. patagonica, this pocket-forming tissue is comparable to the flap of tissue covering seeds of compressed cheirolepidiaceous cones and is probably the most diagnostic character for seed cones of the family. Pararaucaria patagonica is assigned to Cheirolepidiaceae, documenting anatomical features for seed cones of the family and providing evidence for the antiquity of pinoid conifers leading to the origin of Pinaceae. A list of key morphological and anatomical characters for seed cones of Cheirolepidiaceae is developed to facilitate assignment of a much broader range of fossil remains to the family. This confirms the presence of Cheirolepidiaceae in the Jurassic of the Southern Hemisphere, which was previously suspected from palynological records.

  11. High-quality 3D correction of ring and radiant artifacts in flat panel detector-based cone beam volume CT imaging

    Science.gov (United States)

    Abu Anas, Emran Mohammad; Kim, Jae Gon; Lee, Soo Yeol; Kamrul Hasan, Md

    2011-10-01

    The use of an x-ray flat panel detector is increasingly becoming popular in 3D cone beam volume CT machines. Due to the deficient semiconductor array manufacturing process, the cone beam projection data are often corrupted by different types of abnormalities, which cause severe ring and radiant artifacts in a cone beam reconstruction image, and as a result, the diagnostic image quality is degraded. In this paper, a novel technique is presented for the correction of error in the 2D cone beam projections due to abnormalities often observed in 2D x-ray flat panel detectors. Template images are derived from the responses of the detector pixels using their statistical properties and then an effective non-causal derivative-based detection algorithm in 2D space is presented for the detection of defective and mis-calibrated detector elements separately. An image inpainting-based 3D correction scheme is proposed for the estimation of responses of defective detector elements, and the responses of the mis-calibrated detector elements are corrected using the normalization technique. For real-time implementation, a simplification of the proposed off-line method is also suggested. Finally, the proposed algorithms are tested using different real cone beam volume CT images and the experimental results demonstrate that the proposed methods can effectively remove ring and radiant artifacts from cone beam volume CT images compared to other reported techniques in the literature.

  12. High-quality 3D correction of ring and radiant artifacts in flat panel detector-based cone beam volume CT imaging

    International Nuclear Information System (INIS)

    Anas, Emran Mohammad Abu; Hasan, Md Kamrul; Kim, Jae Gon; Lee, Soo Yeol

    2011-01-01

    The use of an x-ray flat panel detector is increasingly becoming popular in 3D cone beam volume CT machines. Due to the deficient semiconductor array manufacturing process, the cone beam projection data are often corrupted by different types of abnormalities, which cause severe ring and radiant artifacts in a cone beam reconstruction image, and as a result, the diagnostic image quality is degraded. In this paper, a novel technique is presented for the correction of error in the 2D cone beam projections due to abnormalities often observed in 2D x-ray flat panel detectors. Template images are derived from the responses of the detector pixels using their statistical properties and then an effective non-causal derivative-based detection algorithm in 2D space is presented for the detection of defective and mis-calibrated detector elements separately. An image inpainting-based 3D correction scheme is proposed for the estimation of responses of defective detector elements, and the responses of the mis-calibrated detector elements are corrected using the normalization technique. For real-time implementation, a simplification of the proposed off-line method is also suggested. Finally, the proposed algorithms are tested using different real cone beam volume CT images and the experimental results demonstrate that the proposed methods can effectively remove ring and radiant artifacts from cone beam volume CT images compared to other reported techniques in the literature.

  13. Physico-chemical characterization of pine cone shell and its use as biosorbent and fuel.

    Science.gov (United States)

    Almendros, A I; Martín-Lara, M A; Ronda, A; Pérez, A; Blázquez, G; Calero, M

    2015-11-01

    Physico-chemical properties of pine cone shell have been determined. Results of characterization study showed that pine cone shell could be used as biosorbent of nickel from aqueous solutions in a fixed-bed column and later as input material in thermochemical processes. To study the behavior of Ni-loaded pine cone shell as fuel, non-isothermal thermogravimetric tests were performed. These tests showed that, in nitrogen atmosphere, the main decomposition occurs from 200°C to 500°C and, in oxidant atmosphere, the behavior is of type "combustion+pyrolysis" (at higher temperatures there is a clear decomposition of residue formed during the initial steps). Finally, the effect of the presence of Ni was analyzed. Thermogravimetric curves did not change their profile and the total amount of nickel was detected in char-ash fraction and not in flue gases. These results suggest that nickel does not form volatile compounds at considered operational conditions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Bending, force recovery, and D-cones in origami inspired model geometries

    Science.gov (United States)

    Eldar, Theresa; Rozairo, Damith; Croll, Andrew B.

    The need for materials with advanced functionality has driven a considerable amount of modern materials science. One idea that has gained significant traction is combining of the ideas Origami and Kirigami with existing materials to build in advanced functionality. In most origami damage is induced in order to trap areas of high curvature in desirable locations in a material. However, the long term and dynamic consequences of local failure are largely unknown. In order to gauge the complex interplay of material properties, relaxation and failure in a set of model thin films, a series of bending and force recovery experiments were carried out. We focus on three materials; polydimethylsiloxane (PDMS), polycarbonate (PC), and polystyrene (PS) chosen for their varying responses to stress. We first measured the load bearing capacity of a single bend in each material, examining the force recovery of bends at various curvatures. Next we examined a doubly folded system in which a single developable cone was created in a similar manner. While the D-cone clearly has massive local consequences for each system, it plays an insignificant role in the system's overall behavior. Finally, we considered higher order combinations of d-cones, ridges and bends. AFOSR under the Young Investigator Program (FA9550-15-1-0168).

  15. liger: mock relativistic light cones from Newtonian simulations

    Science.gov (United States)

    Borzyszkowski, Mikolaj; Bertacca, Daniele; Porciani, Cristiano

    2017-11-01

    We introduce a method to create mock galaxy catalogues in redshift space including general relativistic effects to linear order in the cosmological perturbations. We dub our method liger, short for `light cones with general relativity'. liger takes a (N-body or hydrodynamic) Newtonian simulation as an input and outputs the distribution of galaxies in comoving redshift space. This result is achieved making use of a coordinate transformation and simultaneously accounting for lensing magnification. The calculation includes both local corrections and terms that have been integrated along the line of sight. Our fast implementation allows the production of many realizations that can be used to forecast the performance of forthcoming wide-angle surveys and to estimate the covariance matrix of the observables. To facilitate this use, we also present a variant of liger designed for large-volume simulations with low-mass resolution. In this case, the galaxy distribution on large scales is obtained by biasing the matter-density field. Finally, we present two sample applications of liger. First, we discuss the impact of weak gravitational lensing on to the angular clustering of galaxies in a Euclid-like survey. In agreement with previous analytical studies, we find that magnification bias can be measured with high confidence. Secondly, we focus on two generally neglected Doppler-induced effects: magnification and the change of number counts with redshift. We show that the corresponding redshift-space distortions can be detected at 5.5σ significance with the completed Square Kilometre Array.

  16. Variability of silver fir (Abies alba Mill.) cones – variability of cone parameters

    OpenAIRE

    Aniszewska, Monika; Błuszkowska, Urszula

    2016-01-01

    This study aimed at determining the shape of closed silver fir cones from the Jawor Forest District (Wroclaw), based purely on measurements of their length and thickness. Using these two parameters, the most accurate estimations were achieved with a fourth-degree polynomial fitting function. We then calculated the cones’ surface area and volume in three different ways: 1) Using the fourth-degree polynomial shape estimation, 2) Introducing indicators of compliance (k1, k2, k3) to calculate the...

  17. Cone beam computed tomography in endodontic

    Energy Technology Data Exchange (ETDEWEB)

    Durack, Conor; Patel, Shanon, E-mail: conordurack1@hotmail.com [Unit of Endodontology, Department of Conservative Dentistry, King' s College London, London (United Kingdom)

    2012-07-01

    Cone beam computed tomography (CBCT) is a contemporary, radiological imaging system designed specifically for use on the maxillofacial skeleton. The system overcomes many of the limitations of conventional radiography by producing undistorted, three-dimensional images of the area under examination. These properties make this form of imaging particularly suitable for use in endodontic. The clinician can obtain an enhanced appreciation of the anatomy being assessed, leading to an improvement in the detection of endodontic disease and resulting in more effective treatment planning. In addition, CBCT operates with a significantly lower effective radiation dose when compared with conventional computed tomography (CT). The purpose of this paper is to review the current literature relating to the limitations and potential applications of CBCT in endodontic practice. (author)

  18. Contact interactions for light-cone superstrings

    International Nuclear Information System (INIS)

    Restuccia, A.; Taylor, J.G.

    1990-01-01

    It was pointed out recently that the cubic interactions of the original light-cone gauge superstring field theory were incomplete. The addition of a quartic term H 4 was required in order to ensure that the total Hamiltonian, now (H 2 + H 3 + H 4 ) instead of (H 2 + H 3 ), be positive (where H n denotes a contribution to the L.C. field theory Hamiltonian of degree n in the fields). This latter is a condition guaranteed by [10]-SUSY; its violation would correspond to a violation of [10]-SUSY, which, however, the theory is supposed to possess. The construction of the full [10]-SUSY algebra was proposed in, but not completed there. These questions were analysed more fully in previous papers It is the purpose of this article to survey these developments. (author)

  19. Chemical profile of Taxodium distichum winter cones

    Directory of Open Access Journals (Sweden)

    Đapić Nina M.

    2017-01-01

    Full Text Available This work is concerned with the chemical profile of Taxodium distichum winter cones. The extract obtained after maceration in absolute ethanol was subjected to qualitative analysis by gas chromatography/mass spectrometry and quantification was done by gas chromatography/ flame ionization detector. The chromatogram revealed the presence of 53 compounds, of which 33 compounds were identified. The extract contained oxygenated monoterpenes (12.42%, sesquiterpenes (5.18%, oxygenated sesquiterpenes (17.41%, diterpenes (1.15%, and oxygenated diterpenes (30.87%, while the amount of retinoic acid was 0.32%. Monoacylglycerols were detected in the amount of 4.32%. The most abundant compounds were: caryophyllene oxide (14.27%, 6,7-dehydro-ferruginol (12.49%, bornyl acetate (10.96%, 6- deoxy-taxodione (9.50% and trans-caryophyllene (4.20%.

  20. Numerical Aspects of Cone Beam Contour Reconstruction

    Science.gov (United States)

    Louis, Alfred K.

    2017-12-01

    We describe a method for directly calculating the contours of a function from cone beam data. The algorithm is based on a new inversion formula for the gradient of a function presented in Louis (Inverse Probl 32(11):115005, 2016. http://stacks.iop.org/0266-5611/32/i=11/a=115005). The Radon transform of the gradient is found by using a Grangeat type of formula, reducing the inversion problem to the inversion of the Radon transform. In that way the influence of the scanning curve, vital for all exact inversion formulas for complete data, is avoided Numerical results are presented for the circular scanning geometry which neither fulfills the Tuy-Kirillov condition nor the much weaker condition given by the author in Louis (Inverse Probl 32(11):115005, 2016. http://stacks.iop.org/0266-5611/32/i=11/a=115005).

  1. Hybrid radial-cones trajectory for accelerated magnetic resonance imaging

    Science.gov (United States)

    Johnson, Kevin M.

    2016-01-01

    Purpose To design and develop ultra-short echo time k-space sampling schemes, radial-cones, which enable high sampling efficiency while maintaining compatibility with parallel imaging and compressed sensing reconstructions. Theory and Methods Radial-cones is a trajectory which samples 3D k-space utilizing a single base cone distributed along radial dimensions through a cost function based optimization. Trajectories were generated for highly undersampled, short readout sampling and compared to 3D radial sampling in point spread function (PSF) analysis, digital and physical phantoms, and initial human volunteers. Parallel imaging reconstructions were evaluated with and without the use of compressed sensing based regularization. Results Compared to 3D radial sampling, radial-cones reduced the peak value and energy of PSF aliasing. In both digital and physical phantoms, this improved sampling behavior corresponded to a reduction in the root-mean square error with a further reduction utilizing compressed sensing. A slight increase in noise and corresponding increase in apparent resolution was observed with radial-cones. In in-vivo feasibility testing, radial-cones reconstructed images has markedly lower apparent artifacts. Ultimate gains in imaging performance were limited by off-resonance blurring. Conclusion Radial-cones is an efficient Non-Cartesian sampling scheme enabling short echo readout with a high level of compatibility with parallel imaging and compressed sensing. PMID:27017991

  2. Optics of cone photoreceptors in the chicken (Gallus gallus domesticus).

    Science.gov (United States)

    Wilby, David; Toomey, Matthew B; Olsson, Peter; Frederiksen, Rikard; Cornwall, M Carter; Oulton, Ruth; Kelber, Almut; Corbo, Joseph C; Roberts, Nicholas W

    2015-10-06

    Vision is the primary sensory modality of birds, and its importance is evident in the sophistication of their visual systems. Coloured oil droplets in the cone photoreceptors represent an adaptation in the avian retina, acting as long-pass colour filters. However, we currently lack understanding of how the optical properties and morphology of component structures (e.g. oil droplet, mitochondrial ellipsoid and outer segment) of the cone photoreceptor influence the transmission of light into the outer segment and the ultimate effect they have on receptor sensitivity. In this study, we use data from microspectrophotometry, digital holographic microscopy and electron microscopy to inform electromagnetic models of avian cone photoreceptors to quantitatively investigate the integrated optical function of the cell. We find that pigmented oil droplets primarily function as spectral filters, not light collection devices, although the mitochondrial ellipsoid improves optical coupling between the inner segment and oil droplet. In contrast, unpigmented droplets found in violet-sensitive cones double sensitivity at its peak relative to other cone types. Oil droplets and ellipsoids both narrow the angular sensitivity of single cone photoreceptors, but not as strongly as those in human cones. © 2015 The Authors.

  3. Cadmium Removal from Aqueous Solutions by Ground Pine Cone

    Directory of Open Access Journals (Sweden)

    H Izanloo, S Nasseri

    2005-01-01

    Full Text Available A study on the removal of cadmium ions from aqueous solutions by pine cone was conducted in batch conditions. Kinetic data and equilibrium removal isotherms were obtained. The influence of different experimental parameters such as contact time, initial concentration of cadmium, pine cone mass and particle size, and temperature on the kinetics of cadmium removal was studied. Results showed that the main parameters that played an important role in removal phenomenon were initial cadmium concentration, particle size and pine cone mass. The necessary time to reach equilibrium was between 4 and 7 hours based on the initial concentration of cadmium. The capacity of cadmium adsorption at equilibrium increased with the decrease of pine cone particle size. The capacity of cadmium adsorption at equilibrium by pine cone increased with the quantity of pine cone introduced (1–4 g/L. Temperature in the range of 20-30°C showed a restricted effect on the removal kinetics (13.56 mg/g at 20°C and a low capacity of adsorption about 11.48 mg/g at 30°C. The process followed pseudo second-order kinetics. The cadmium uptake of pine cone was quantitatively evaluated using adsorption isotherms. Results indicated that the Langmuir model gave a better fit to the experimental data in comparison with the Freundlich equation.

  4. On intense proton beam generation and transport in hollow cones

    Directory of Open Access Journals (Sweden)

    J.J. Honrubia

    2017-01-01

    Full Text Available Proton generation, transport and interaction with hollow cone targets are investigated by means of two-dimensional PIC simulations. A scaled-down hollow cone with gold walls, a carbon tip and a curved hydrogen foil inside the cone has been considered. Proton acceleration is driven by a 1020 W·cm−2 and 1 ps laser pulse focused on the hydrogen foil. Simulations show an important surface current at the cone walls which generates a magnetic field. This magnetic field is dragged by the quasi-neutral plasma formed by fast protons and co-moving electrons when they propagate towards the cone tip. As a result, a tens of kT Bz field is set up at the cone tip, which is strong enough to deflect the protons and increase the beam divergence substantially. We propose using heavy materials at the cone tip and increasing the laser intensity in order to mitigate magnetic field generation and proton beam divergence.

  5. Hermitian Yang-Mills instantons on Calabi-Yau cones

    Science.gov (United States)

    Paccetti Correia, Filipe

    2009-12-01

    We study and construct non-abelian hermitian Yang-Mills (HYM) instantons on Calabi-Yau cones. By means of a particular isometry preserving ansatz, the HYM equations are reduced to a novel Higgs-Yang-Mills flow on the Einstein-Kähler base. For any 2dBbb C-dimensional Calabi-Yau cone, we find explicit solutions of the flow equations that correspond to non-trivial SU(dBbb C) HYM instantons. These can be regarded as deformations of the spin connection of the Calabi-Yau cone.

  6. Instantaneous interactions of hadrons on the light cone

    International Nuclear Information System (INIS)

    Hyer, T.

    1994-01-01

    Hadron wave functions are most naturally defined in the framework of light-cone quantization, a Hamiltonian formulation quantized at equal light-cone ''time'' τ≡t+z. One feature of the light-cone perturbation theory is the presence of instantaneous interactions, which complicate the consideration of processes involving bound states. We show that these interactions can be written in a simple and general form, parametrized by an instantaneous contribution ψ to the hadronic wave function. We use the rotational invariance of Feynman diagrams to relate this instantaneous piece of the meson wave function to the propagating part, and to obtain constraints relating wave functions and quark fragmentation amplitudes

  7. Concrescence: Cone-Beam Computed Tomography Imaging Perspective.

    Science.gov (United States)

    Syed, Ali Zakir; Alluri, LeelaSubhashini Choudary; Mallela, Dhiraj; Frazee, Troy

    2016-01-01

    Concrescence is a form of twinning, formed by the confluence of cementum of two teeth at the root level. The diagnosis of concrescence has largely relied on the conventional 2D imaging. The 2D imaging has inherent limitations such as distortion and superimposition. Cone-Beam CT eliminates these limitations. The aim of this article was to describe a case of dental abnormality using Cone-Beam CT imaging modality. Volumetric data demonstrated confluence of left mandibular third molar with a paramolar, a supernumerary tooth. To our knowledge, this is the second case in the dental literature reported demonstrating the use of Cone-Beam CT in the diagnosis of concrescence.

  8. Alopecia associated with unexpected leakage from electron cone

    Energy Technology Data Exchange (ETDEWEB)

    Wen, B.C.; Pennington, E.C.; Hussey, D.H.; Jani, S.K.

    1989-06-01

    Excessive irradiation due to unexpected leakage was found on a patient receiving electron beam therapy. The cause of this leakage was analyzed and the amount of leakage was measured for different electron beam energies. The highest leakage occurred with a 6 x 6 cm cone using a 12 MeV electron beam. The leakage dose measured along the side of the cone could be as great as 40%. Until the cones are modified or redesigned, it is advised that all patient setups be carefully reviewed to assure that no significant patient areas are in the side scatter region.

  9. Alopecia associated with unexpected leakage from electron cone

    International Nuclear Information System (INIS)

    Wen, B.C.; Pennington, E.C.; Hussey, D.H.; Jani, S.K.

    1989-01-01

    Excessive irradiation due to unexpected leakage was found on a patient receiving electron beam therapy. The cause of this leakage was analyzed and the amount of leakage was measured for different electron beam energies. The highest leakage occurred with a 6 x 6 cm cone using a 12 MeV electron beam. The leakage dose measured along the side of the cone could be as great as 40%. Until the cones are modified or redesigned, it is advised that all patient setups be carefully reviewed to assure that no significant patient areas are in the side scatter region

  10. Formation of focused laser beams with a hollow metal cone

    International Nuclear Information System (INIS)

    Wu, Pinghui; Pan, Quanjun; Wei, Kaihua; Wu, Bo; Jiang, Peipei; Li, Jia; Peng, Xuefeng

    2015-01-01

    A hollow metal cone is designed to focus a laser beam into a tiny highly localized beam spot. The finite difference time domain method has been introduced to investigate the beam focusing effect along the propagation direction. Without considering the laser–plasma nonlinear interaction, the numerical calculation results show that a focal spot with a full width at half maximum of ∼0.7λ at greatly enhanced intensity and a depth of focus of ∼3λ can be achieved. In addition, the influences of cone angle, cone tip size, metal materials, sidewall thickness and incident wavelength on the focusing properties are analyzed in detail. (letter)

  11. Pulsar average wave forms and hollow-cone beam models

    Science.gov (United States)

    Backer, D. C.

    1976-01-01

    Pulsar wave forms have been analyzed from observations conducted over a wide radio-frequency range to assess the wave-form morphologies and to measure wave-form widths. The results of the analysis compare favorably with the predictions of a model with a hollow-cone beam of fixed dimensions and with random orientation of both the observer and the cone axis with respect to the pulsar spin axis. A class of three-component wave forms is included in the model by adding a central pencil beam to the hollow-cone hypothesis. The consequences of a number of discrepancies between observations and quantitative predictions of the model are discussed.

  12. Focusing of relativistic electron beams by a solid cone

    International Nuclear Information System (INIS)

    Chen, M; Sheng, Z M; Ma, Y Y; Li, Y T; Yuan, X H; Zhang, J

    2008-01-01

    A scheme for focusing relativistic electron beams has been proposed by use of a solid cone based upon two dimensional particle-in-cell simulations. We compare the transport of hot electrons, produced during the interaction of ultra-intense laser pulse with the targets, through the cone shape target and a flat target. It is found that relativistic electrons can be confined and focused effectively in the cone target case, where both the electron density and temperature have been increased more significantly than the flat target case

  13. Impact of cone-beam computed tomography on implant planning and on prediction of implant size

    International Nuclear Information System (INIS)

    Pedroso, Ludmila Assuncao de Mello; Silva, Maria Alves Garcia Santos; Garcia, Robson Rodrigues; Leles, Jose Luiz Rodrigues; Leles, Claudio Rodrigues

    2013-01-01

    The aim was to investigate the impact of cone-beam computed tomography (CBCT) on implant planning and on prediction of final implant size. Consecutive patients referred for implant treatment were submitted to clinical examination, panoramic (PAN) radiography and a CBCT exam. Initial planning of implant length and width was assessed based on clinical and PAN exams, and final planning, on CBCT exam to complement diagnosis. The actual dimensions of the implants placed during surgery were compared with those obtained during initial and final planning, using the McNemmar test (p 0.05). It was concluded that CBCT improves the ability of predicting the actual implant length and reduces inaccuracy in surgical dental implant planning. (author)

  14. Análise espacial da ocorrência do índice de cone em área sob semeadura direta e sua relação com fatores do solo Spatial analysis of cone index under no-till and its relationship with soil physical attributes

    Directory of Open Access Journals (Sweden)

    José P. Molin

    2006-08-01

    Full Text Available O presente estudo teve o objetivo de analisar, em uma lavoura sob semeadura direta, a distribuição vertical e horizontal da resistência à penetração medida por valores georreferenciados do índice de cone (IC e a influência do teor de água do solo, permitindo a interpolação para análise de relações causa e efeito. Fatores importantes, como o teor de argila, silte, densidade, espaço poroso e teor de matéria orgânica do solo também foram mensurados. Utilizou-se de um penetrômetro hidráulico eletrônico, receptor de GPS, amostrador de solo e programas computacionais para o tratamento e obtenção dos resultados. A análise foi feita a partir dos mapas (não apresentados para a espacialização dos atributos e pela regressão entre os dados interpolados por meio da função que apresentou o coeficiente de determinação (R² mais elevado. Constatou-se a ocorrência de valores maiores para o IC nas profundidades compreendidas de 0,10 a 0,15 m, com menores valores em locais com maior teor de matéria orgânica, a qual coincidiu com maiores teores de argila e silte. O IC foi influenciado principalmente pelo teor de água, densidade e espaço poroso do solo.The objective of this study was to measure the vertical and horizontal distribution of georeferenced values of cone index (CI in a no-till field and the influence of soil water content. Data were interpolated to allow for cause and effect analysis. Other important factors as clay and silt content, bulk density, porous space and organic matter content were also measured. A penetrometer mounted on a tractor and equipped with a load cell was used together with GPS receiver, soil auger and computer programs to collect and analyze the data. Analysis was conducted based on maps of interpolated data after choosing the models with the highest determination coefficient (R² and regressions among them. High CI values were found at depths between 0.10 to 0.15 m. Lower values of CI were

  15. Summit Station Skiway Review

    Science.gov (United States)

    2013-03-01

    determine its usefulness for enhancing runway performance. We docu- mented the snow strength with a Rammsonde Cone Penetrometer and de- termined the... Penetrometer and delivered it to Summit during the Phase III turnover in February 2011 so that it would be available for testing during spring skiway...discussed current maintenance practices with the Station Manager, trained staff on proper use of the Rammsonde Cone Penetrometer , inspected current

  16. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    DeTar, Carleton [P.I.

    2012-12-10

    This document constitutes the Final Report for award DE-FC02-06ER41446 as required by the Office of Science. It summarizes accomplishments and provides copies of scientific publications with significant contribution from this award.

  17. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Gurney, Kevin R. [Arizona Univ., Mesa, AZ (United States)

    2015-01-12

    This document constitutes the final report under DOE grant DE-FG-08ER64649. The organization of this document is as follows: first, I will review the original scope of the proposed research. Second, I will present the current draft of a paper nearing submission to Nature Climate Change on the initial results of this funded effort. Finally, I will present the last phase of the research under this grant which has supported a Ph.D. student. To that end, I will present the graduate student’s proposed research, a portion of which is completed and reflected in the paper nearing submission. This final work phase will be completed in the next 12 months. This final workphase will likely result in 1-2 additional publications and we consider the results (as exemplified by the current paper) high quality. The continuing results will acknowledge the funding provided by DOE grant DE-FG-08ER64649.

  18. Propagation characteristics of resonance cone in a nonuniform magnetic field

    International Nuclear Information System (INIS)

    Ohnuma, T.; Sanuki, H.

    1984-01-01

    Propagation characteristics of resonance cone field for frequencies below the electron cyclotron frequency are described in a mirror magnetic field on the basis of fluid equation. Theoretical results are compared qualitatively with those of experiment

  19. New fixed and periodic point results on cone metric spaces

    Directory of Open Access Journals (Sweden)

    Ghasem Soleimani Rad

    2014-05-01

    Full Text Available In this paper, several xed point theorems for T-contraction of two maps on cone metric spaces under normality condition are proved. Obtained results extend and generalize well-known comparable results in the literature.

  20. Determination of the Resistance of Cone-Shaped Solid Electrodes

    DEFF Research Database (Denmark)

    Frandsen, Henrik Lund; Hendriksen, Peter Vang; Koch, Søren

    2017-01-01

    during processing can be avoided. Newman's formula for current constriction in the electrolyte is then used to deduce the active contact area based on the ohmic resistance of the cell, and from this the surface specific electro-catalytic activity. However, for electrode materials with low electrical...... conductivity (like Ce1-xPrxO2-δ), the resistance of the cell is significantly influenced by the ohmic resistance of the cone electrode, wherefore it must be included. In this work the ohmic resistance of a cone is modelled analytically based on simplified geometries. The two analytical models only differ...... by a model specific pre-factor, which is consequently determined by a finite element model. The model was applied to measurements on cones of Ce1-xPrxO2-δ  characterized on an YSZ electrolyte. Conclusively, the finite element model was used to obtain a formula for the resistance for different cone angles...

  1. Holographic entanglement entropy for hollow cones and banana shaped regions

    Energy Technology Data Exchange (ETDEWEB)

    Dorn, Harald [Institut für Physik und IRIS Adlershof, Humboldt-Universität zu Berlin,Zum Großen Windkanal 6, D-12489 Berlin (Germany)

    2016-06-09

    We consider banana shaped regions as examples of compact regions, whose boundary has two conical singularities. Their regularised holographic entropy is calculated with all divergent as well as finite terms. The coefficient of the squared logarithmic divergence, also in such a case with internally curved boundary, agrees with that calculated in the literature for infinite circular cones with their internally flat boundary. For the otherwise conformally invariant coefficient of the ordinary logarithmic divergence an anomaly under exceptional conformal transformations is observed. The construction of minimal submanifolds, needed for the entanglement entropy of cones, requires fine-tuning of Cauchy data. Perturbations of such fine-tuning leads to solutions relevant for hollow cones. The divergent parts for the entanglement entropy of hollow cones are calculated. Increasing the difference between the opening angles of their outer and inner boundary, one finds a transition between connected solutions for small differences to disconnected solutions for larger ones.

  2. Effect of loss cone on confinement in toroidal helical device

    International Nuclear Information System (INIS)

    Itoh, K.; Itoh, S.-I.; Fukuyama, A.; Hanatani, K.

    1988-12-01

    Analytical estimation is given on the loss cone in the toroidal helical devices in the presence of the radial electric field and the modulation of the helical ripple. The minimum energy of particles entering the loss cone is calculated. The modulation is not always effective in reducing the loss in the presence of the radial electric field. The plasma loss due to the loss cone is estimated in the collisionless limit. The radial electric field is estimated in the presence of the loss cone. It is found that the transition to the solution with positive radial electric field, which is necessary to achieve the high-ion-temperature mode, becomes difficult. This difficulty is large for the systems with the small helical ripple. (author)

  3. Development of pits and cones on ion bombarded copper

    International Nuclear Information System (INIS)

    Tanovic, L.A.; Carter, G.; Nobes, M.J.; Whitton, I.L.; Williams, J.S.

    1980-01-01

    The formation of pits and cones on Ar ion bombarded copper has been studied. Carefully polished surfaces of large grained 99.999% pure copper crystals have been bombarded at normal incidence with 40 keV argon ions. The cone formation has been investigated for annealed and non-annealed crystals at room temperature and at 30 K and in the case of monocrystal and polycrystal samples. Although in the most other studies the presence of impurities is as a necessary condition for generation of cones and pits the obtained experimental results show that under certain conditions these features are formed on clean surfaces. It is shown that the dominant parameter in the production of cones on copper is the crystal orientation [ru

  4. Syndecan Promotes Axon Regeneration by Stabilizing Growth Cone Migration

    Directory of Open Access Journals (Sweden)

    Tyson J. Edwards

    2014-07-01

    Full Text Available Growth cones facilitate the repair of nervous system damage by providing the driving force for axon regeneration. Using single-neuron laser axotomy and in vivo time-lapse imaging, we show that syndecan, a heparan sulfate (HS proteoglycan, is required for growth cone function during axon regeneration in C. elegans. In the absence of syndecan, regenerating growth cones form but are unstable and collapse, decreasing the effective growth rate and impeding regrowth to target cells. We provide evidence that syndecan has two distinct functions during axon regeneration: (1 a canonical function in axon guidance that requires expression outside the nervous system and depends on HS chains and (2 an intrinsic function in growth cone stabilization that is mediated by the syndecan core protein, independently of HS. Thus, syndecan is a regulator of a critical choke point in nervous system repair.

  5. Helical cardiac cone beam reconstruction using retrospective ECG gating

    International Nuclear Information System (INIS)

    Grass, M; Manzke, R; Nielsen, T; Koken, P; Proksa, R; Natanzon, M; Shechter, G

    2003-01-01

    In modern computer tomography (CT) systems, the fast rotating gantry and the increased detector width enable 3D imaging of the heart. Cardiac volume CT has a high potential for non-invasive coronary angiography with high spatial resolution and short scan time. Due to the increased detector width, true cone beam reconstruction methods are needed instead of adapted 2D reconstruction schemes. In this paper, the extended cardiac reconstruction method is introduced. It integrates the idea of retrospectively gated cardiac reconstruction for helical data acquisition into a cone beam reconstruction framework. It leads to an efficient and flexible algorithmic scheme for the reconstruction of single- and multi-phase cardiac volume datasets. The method automatically adapts the number of cardiac cycles used for the reconstruction. The cone beam geometry is fully taken into account during the reconstruction process. Within this paper, results are presented on patient datasets which have been acquired using a 16-slice cone beam CT system

  6. Theory of suppression of loss cone instabilities by electron beams

    International Nuclear Information System (INIS)

    Sinha, A.; Sinha, M.

    1981-01-01

    A new mechanism for the suppression of Drift Cyclotron Loss Cone instabilities by electron beams injected along the field lines is given. The mechanism explains some of the recent observations. (author)

  7. Direct cone beam SPECT reconstruction with camera tilt

    International Nuclear Information System (INIS)

    Jianying Li; Jaszczak, R.J.; Greer, K.L.; Coleman, R.E.; Zongjian Cao; Tsui, B.M.W.

    1993-01-01

    A filtered backprojection (FBP) algorithm is derived to perform cone beam (CB) single-photon emission computed tomography (SPECT) reconstruction with camera tilt using circular orbits. This algorithm reconstructs the tilted angle CB projection data directly by incorporating the tilt angle into it. When the tilt angle becomes zero, this algorithm reduces to that of Feldkamp. Experimentally acquired phantom studies using both a two-point source and the three-dimensional Hoffman brain phantom have been performed. The transaxial tilted cone beam brain images and profiles obtained using the new algorithm are compared with those without camera tilt. For those slices which have approximately the same distance from the detector in both tilt and non-tilt set-ups, the two transaxial reconstructions have similar profiles. The two-point source images reconstructed from this new algorithm and the tilted cone beam brain images are also compared with those reconstructed from the existing tilted cone beam algorithm. (author)

  8. Breakaway safety feature for an intra-oral cone system

    International Nuclear Information System (INIS)

    Biggs, P.J.; Wang, C.C.

    1984-01-01

    With an increasing number of high energy accelerators in operation, intra-oral electron radiotherapy is likely to become a more widely-used modality in the treatment of lesions of the oral cavity. However, there is one potential problem associated with this modality which concerns patient safety. There must never be any uncontrolled movement of the couch or gantry while the cone is in the patients's mouth, otherwise serious consequences could occur. In an effort to overcome this problem, a set of cones previously constructed by the authors for use in intra-oral electron radiotherapy has been modified to include a breakaway safety feature. This modification consists of separating the plate into which each of the treatment cones screws, into two pieces, the dividing line being in the shape of a cone frustum flaring out in the upward direction

  9. Testing the reliability of ice-cream cone model

    Science.gov (United States)

    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.

  10. A Clinical Evaluation Of Cone Beam Computed Tomography

    Science.gov (United States)

    2016-06-01

    reliability of multidetector computed tomography and cone beam computed tomography in the assessment of dental implant site dimensions. Dentomaxillofacial...A CLINICAL EVALUATION OF CONE BEAM COMPUTED TOMOGRAPHY by Bryan James Behm, D.D.S. Lieutenant, Dental Corps United States Navy A thesis...submitted to the Faculty of the Endodontic Graduate Program Naval Postgraduate Dental School Uniformed Services University of the Health Sciences in

  11. Weather effects on the success of longleaf pine cone crops

    Science.gov (United States)

    Daniel J. Leduc; Shi-Jean Susana Sung; Dale G. Brockway; Mary Anne Sword Sayer

    2016-01-01

    We used National Oceanic and Atmospheric Administration weather data and historical records of cone crops from across the South to relate weather conditions to the yield of cones in 10 longleaf pine (Pinus palustris Mill.) stands. Seed development in this species occurs over a three-year time period and weather conditions during any part of this...

  12. Delayed cone-opponent signals in the luminance pathway.

    Science.gov (United States)

    Stockman, Andrew; Henning, G Bruce; Anwar, Sharif; Starba, Robert; Rider, Andrew T

    2018-02-01

    Cone signals in the luminance or achromatic pathway were investigated by measuring how the perceptual timing of M- or L-cone-detected flicker depended on temporal frequency and chromatic adaptation. Relative timings were measured, as a function of temporal frequency, by superimposing M- or L-cone-isolating flicker on "equichromatic" flicker (flicker of the same wavelength as the background) and asking observers to vary contrast and phase to cancel the perception of flicker. Measurements were made in four observers on up to 35 different backgrounds varying in wavelength and radiance. Observers showed substantial perceptual delays or advances of L- and M-cone flicker that varied systematically with cone class, background wavelength, and radiance. Delays were largest for M-cone-isolating flicker. Although complex, the results can be characterised by a surprisingly simple model in which the representations of L- and M-cone flicker are comprised not only of a fast copy of the flicker signal, but also of a slow copy that is delayed by roughly 30 ms and varies in strength and sign with both background wavelength and radiance. The delays, which are too large to be due to selective cone adaptation by the chromatic backgrounds, must arise postreceptorally. Clear evidence for the slow signals can also be found in physiological measurements of horizontal and magnocellular ganglion cells, thus placing the origin of the slow signals in the retina-most likely in an extended horizontal cell network. Luminance-equated stimuli chosen to isolate chromatic channels may inadvertently generate slow signals in the luminance channel.

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

    Science.gov (United States)

    2016-06-02

    The primary intensities required to generate a particular cone excitation levels is determined by This application uses the CIE 2006 LMS... mathematics needed to implement the technique were published by Estevez and Spekreijse in 1982 [5]. Because a test stimulus in the OBVA CCT...at a criterion level ) is primarily determined by the most sensitive mechanism. 2. Cone-opponent mechanisms are more sensitive than the achromatic

  14. Cinder cones of Mount Slamet, Central Java, Indonesia

    Directory of Open Access Journals (Sweden)

    Igan S. SutawIdjaja

    2014-06-01

    Full Text Available http://dx.doi.org/10.17014/ijog.vol4no1.20096The Mount Slamet volcanic field in Central Java, Indonesia, contains thirty five cinder cones within an area of 90 sq. km in the east flank of the volcano. The cinder cones occur singly or in small groups, with diameter of the base ranges from 130 - 750 m and the height is around 250 m. Within the volcanic field, the cinder cones are spread over the volcanic area at the distance of 4 to 14 km from the eruption center of the Slamet Volcano. They are concentrated within latitudes 7°11’00” - 7°16’00” S,, and longitudes 109°15’00” - 109°18’00” E. The density of the cinder cones is about 1.5 cones/km2. Most of the cinder cones lie on the Tertiary sedimentary rocks along the NW-trending fault system and on radial fractures. The structural pattern may be related to the radial faults in this region. The cone surfaces are commonly blanketed by Slamet air-falls and lava flows. The deposits consist of poorly bedded, very coarse-grained, occasionally overlain by oxidized scoria, and large-sized of ballistic bombs and blocks. There are various kind of volcanic bombs originating from scoriae ballistic rock fragments. The other kind of volcanic bombs are breadcrust bomb, almond seed or contorted shape. All of the cinder cones have undergone degradation, which can be observed from the characters of gully density and surface morphology. By using Porter parameters, Hco is equal to 0.25 Wco, whilst Wcr is equal to 0.40 Wco. The Hco/Wco ratio is higher than Hco = 0.2 Wco reference line. A radiometric dating using K-Ar method carried out on a scoria bomb yields the age of 0.042 + 0.020 Ma.  

  15. A Monte Carlo investigation of dual-planar circular-orbit cone-beam SPECT

    International Nuclear Information System (INIS)

    Lalush, David S; DiMeo, Andrew J

    2002-01-01

    We use Monte Carlo simulations to study the imaging properties of a design for a dual-planar cone-beam (DPCB) single-photon emission computed tomography (SPECT) system. A dual-planar system uses a dual-camera SPECT system and two cone-beam collimators with foci in different axial planes to increase the effective axial field of view (FOV). We simulated nearly noise-free projection data from a computerized brain phantom and a phantom consisting of a series of points. Four configurations were simulated: parallel-beam low-energy high-resolution (LEHR) as a standard for comparison and DPCB at three radii of rotation (ROR) corresponding to the smallest, average and largest ROR required to clear patients' shoulders based on ergonomic data. We compared global measures of average resolution and total acquired counts for the four configurations. We also estimated local spatial frequency response for reconstructions of point sources. Finally, we estimated a local noise power spectrum by simulating 1000 noise realizations of the brain phantom and estimating a local noise covariance at selected points. The noise power spectra were used to estimate spectral signal to noise ratio (SNR) for each configuration. The resolution in the reconstructed image space ranges from 7.2 mm full-width at half-maximum (FWHM) at the minimum ROR to 9.4 mm FWHM at the maximum ROR. The efficiency is inversely related, ranging from 1.5 times that of parallel LEHR at minimum ROR to 2.5 times that of LEHR at maximum ROR. Estimates of system frequency response roughly correspond to the global resolution estimates, but the cone-beam techniques exhibit an unusual secondary peak in the axial-direction response. Estimates of spectral SNR show that the cone-beam configurations almost always result in higher SNR at all spatial frequencies regardless of ROR. The very largest ROR may be an exception. A larger ROR results in significantly higher SNR for low spatial frequencies with small reductions in SNR for mid

  16. Functional complexity of the axonal growth cone: a proteomic analysis.

    Directory of Open Access Journals (Sweden)

    Adriana Estrada-Bernal

    Full Text Available The growth cone, the tip of the emerging neurite, plays a crucial role in establishing the wiring of the developing nervous system. We performed an extensive proteomic analysis of axonal growth cones isolated from the brains of fetal Sprague-Dawley rats. Approximately 2000 proteins were identified at ≥ 99% confidence level. Using informatics, including functional annotation cluster and KEGG pathway analysis, we found great diversity of proteins involved in axonal pathfinding, cytoskeletal remodeling, vesicular traffic and carbohydrate metabolism, as expected. We also found a large and complex array of proteins involved in translation, protein folding, posttranslational processing, and proteasome/ubiquitination-dependent degradation. Immunofluorescence studies performed on hippocampal neurons in culture confirmed the presence in the axonal growth cone of proteins representative of these processes. These analyses also provide evidence for rough endoplasmic reticulum and reveal a reticular structure equipped with Golgi-like functions in the axonal growth cone. Furthermore, Western blot revealed the growth cone enrichment, relative to fetal brain homogenate, of some of the proteins involved in protein synthesis, folding and catabolism. Our study provides a resource for further research and amplifies the relatively recently developed concept that the axonal growth cone is equipped with proteins capable of performing a highly diverse range of functions.

  17. Meaning of visualizing retinal cone mosaic on adaptive optics images.

    Science.gov (United States)

    Jacob, Julie; Paques, Michel; Krivosic, Valérie; Dupas, Bénédicte; Couturier, Aude; Kulcsar, Caroline; Tadayoni, Ramin; Massin, Pascale; Gaudric, Alain

    2015-01-01

    To explore the anatomic correlation of the retinal cone mosaic on adaptive optics images. Retrospective nonconsecutive observational case series. A retrospective review of the multimodal imaging charts of 6 patients with focal alteration of the cone mosaic on adaptive optics was performed. Retinal diseases included acute posterior multifocal placoid pigment epitheliopathy (n = 1), hydroxychloroquine retinopathy (n = 1), and macular telangiectasia type 2 (n = 4). High-resolution retinal images were obtained using a flood-illumination adaptive optics camera. Images were recorded using standard imaging modalities: color and red-free fundus camera photography; infrared reflectance scanning laser ophthalmoscopy, fluorescein angiography, indocyanine green angiography, and spectral-domain optical coherence tomography (OCT) images. On OCT, in the marginal zone of the lesions, a disappearance of the interdigitation zone was observed, while the ellipsoid zone was preserved. Image recording demonstrated that such attenuation of the interdigitation zone co-localized with the disappearance of the cone mosaic on adaptive optics images. In 1 case, the restoration of the interdigitation zone paralleled that of the cone mosaic after a 2-month follow-up. Our results suggest that the interdigitation zone could contribute substantially to the reflectance of the cone photoreceptor mosaic. The absence of cones on adaptive optics images does not necessarily mean photoreceptor cell death. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. CRYOVOLCANISM AND THE MYSTERY OF THE PATOM CONE

    Directory of Open Access Journals (Sweden)

    Vladimir R. Alekseyev

    2012-01-01

    Full Text Available In the Earth’s regions with cold climate, cryovolcanism is widespread. This phenomena is manifested as eruptions of material due to freezing of closed-type or open-type water-bearing systems which is accompanied by generation of effusive topographic forms, such as «pingo». The Patom cone is a typical structure created by cryovolcanism in fractured bedrocksof the Proterozoic age. The cone was shaped a result of the long-term, possibly multistage freezing of the hydrogeological structure during continuous and complicated phase of cryo- and speleo-genesis. The ice-saturated breccia containing limestone, sandstone and shale, which composed the cone, was subject to slow spreading due to its plastic properties; the top of the mound developed into a subsidence cone bordered by ring-shaped ramparts and a knoll in the middle, while thelongitudinal profile took on an asymmetric form. The absence of soil and vegetation cover on the surface of the cone, and a relatively weak degree of weathering of the rudaceous deposits bear no evidence that the geological object is young. The question as to the age of the cone is still open.

  19. Modulation of growth cone filopodial length by carbon monoxide.

    Science.gov (United States)

    Estes, Stephen; Artinian, Liana; Rehder, Vincent

    2017-06-01

    Carbon monoxide (CO) is physiologically produced via heme degradation by heme oxygenase enzymes. Whereas CO has been identified as an important physiological signaling molecule, the roles it plays in neuronal development and regeneration are poorly understood. During these events, growth cones guide axons through a rich cellular environment to locate target cells and establish synaptic connections. Previously, we have shown that another gaseous signaling molecule, nitric oxide (NO), has potent effects on growth cone motility. With NO and CO sharing similar cellular targets, we wanted to determine whether CO affected growth cone motility as well. We assessed how CO affected growth cone filopodial length and determined the signaling pathway by which this effect was mediated. Using two well-characterized neurons from the freshwater snail, Helisoma trivolvis, it was found that the CO donor, carbon monoxide releasing molecule-2 (CORM-2), increased filopodial length. CO utilized a signaling pathway that involved the activation of soluble guanylyl cyclase, protein kinase G, and ryanodine receptors. While increases in filopodial length often occur from robust increases in intracellular calcium levels, the timing in which CO increased filopodial length corresponded with low basal calcium levels in growth cones. Taken together with findings of a heme oxygenase-like protein in the Helisoma nervous system, these results provide evidence for CO as a modulator of growth cone motility and implicate CO as a neuromodulatory signal during neuronal development and/or regeneration. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 77: 677-690, 2017. © 2016 Wiley Periodicals, Inc.

  20. A reconstruction algorithms for helical cone-beam SPECT

    International Nuclear Information System (INIS)

    Weng, Y.; Zeng, G.L.; Gullberg, G.T.

    1993-01-01

    Cone-beam SPECT provides improved sensitivity for imaging small organs like the brain and heart. However, current cone-beam tomography with the focal point traversing a planar orbit does not acquire sufficient data to give an accurate reconstruction. In this paper, the authors employ a data-acquisition method which obtains complete data for cone-beam SPECT by simultaneously rotating the gamma camera and translating the patient bed, so that cone-beam projections can be obtained with the focal point traversing a helix surrounding the patient. An implementation of Grangeat's algorithm for helical cone-beam projections is developed. The algorithm requires a rebinning step to convert cone-beam data to parallel-beam data which are then reconstructed using the 3D Radon inversion. A fast new rebinning scheme is developed which uses all of the detected data to reconstruct the image and properly normalizes any multiply scanned data. This algorithm is shown to produce less artifacts than the commonly used Feldkamp algorithm when applied to either a circular planar orbit or a helical orbit acquisition. The algorithm can easily be extended to any arbitrary orbit

  1. Singularities of plane complex curves and limits of Kähler metrics with cone singularities. I: Tangent Cones

    Directory of Open Access Journals (Sweden)

    Borbon Martin de

    2017-02-01

    Full Text Available The goal of this article is to provide a construction and classification, in the case of two complex dimensions, of the possible tangent cones at points of limit spaces of non-collapsed sequences of Kähler-Einstein metrics with cone singularities. The proofs and constructions are completely elementary, nevertheless they have an intrinsic beauty. In a few words; tangent cones correspond to spherical metrics with cone singularities in the projective line by means of the Kähler quotient construction with respect to the S1-action generated by the Reeb vector field, except in the irregular case ℂβ₁×ℂβ₂ with β₂/ β₁ ∉ Q.

  2. Computation of supersonic laminar viscous flow past a pointed cone at angle of attack in spinning and coning motion

    Science.gov (United States)

    Agarwal, R.; Rakich, J. V.

    1978-01-01

    Computational results obtained with a parabolic Navier-Stokes marching code are presented for supersonic viscous flow past a pointed cone at angle of attack undergoing a combined spinning and coning motion. The code takes into account the asymmetries in the flow field resulting from the motion and computes the asymmetric shock shape, crossflow and streamwise shear, heat transfer, crossflow separation and vortex structure. The side force and moment are also computed. Reasonably good agreement is obtained with the side force measurements of Schiff and Tobak. Comparison is also made with the only available numerical inviscid analysis. It is found that the asymmetric pressure loads due to coning motion are much larger than all other viscous forces due to spin and coning, making viscous forces negligible in the combined motion.

  3. Narrative Finality

    Directory of Open Access Journals (Sweden)

    Armine Kotin Mortimer

    1981-01-01

    Full Text Available The cloturai device of narration as salvation represents the lack of finality in three novels. In De Beauvoir's Tous les hommes sont mortels an immortal character turns his story to account, but the novel makes a mockery of the historical sense by which men define themselves. In the closing pages of Butor's La Modification , the hero plans to write a book to save himself. Through the thrice-considered portrayal of the Paris-Rome relationship, the ending shows the reader how to bring about closure, but this collective critique written by readers will always be a future book. Simon's La Bataille de Pharsale , the most radical attempt to destroy finality, is an infinite text. No new text can be written. This extreme of perversion guarantees bliss (jouissance . If the ending of De Beauvoir's novel transfers the burden of non-final world onto a new victim, Butor's non-finality lies in the deferral to a future writing, while Simon's writer is stuck in a writing loop, in which writing has become its own end and hence can have no end. The deconstructive and tragic form of contemporary novels proclaims the loss of belief in a finality inherent in the written text, to the profit of writing itself.

  4. Cone beam computed tomography in veterinary dentistry.

    Science.gov (United States)

    Van Thielen, Bert; Siguenza, Francis; Hassan, Bassam

    2012-01-01

    The purpose of this study was to assess the feasibility of cone beam computed tomography (CBCT) in imaging dogs and cats for diagnostic dental veterinary applications. CBCT scans of heads of six dogs and two cats were made. Dental panoramic and multi-planar reformatted (MPR) para-sagittal reconstructions were created using specialized software. Image quality and visibility of anatomical landmarks were subjectively assessed by two observers. Good image quality was obtained for the MPR para-sagittal reconstructions through multiple teeth. The image quality of the panoramic reconstructions of dogs was moderate while the panoramic reconstructions of cats were poor since the images were associated with an increased noise level. Segmental panoramic reconstructions of the mouth seem to be useful for studying the dental anatomy especially in dogs. The results of this study using human dental CBCT technology demonstrate the potential of this scanning technology in veterinary medicine. Unfortunately, the moderate image quality obtained with the CBCT technique reported here seems to be inferior to the diagnostic image quality obtained from 2-dimensional dental radiographs. Further research is required to optimize scanning and reconstruction protocols for veterinary applications.

  5. Traditional Beach Template vs Cross Shore Swash Zone (CSSZ) Placement Methods at Egmont Key, FL: High Silt Content Beneficial Use Placement

    Science.gov (United States)

    2015-10-15

    Time series aerials • Dredging and Placement • Volumes • Compaction - Cone Penetrometer • Mass Balance of “fines” • Fines Content, Density...Courtesy of USACE Jacksonville District BUILDING STRONG® Project Monitoring BUILDING STRONG® Cone Penetrometer • Increase in refusals due to shell

  6. Personnel and Vehicle Data Collection at Aberdeen Proving Ground (APG) and its Distribution for Research

    Science.gov (United States)

    2015-10-01

    Global positioning system (GPS) Garmin e Trex 20x 12 Camera Garmin VIRB 010-01088-10 5 Cone penetrometer Kessler DCP K-100 1 3 Actual photos...classification results of the algorithms being developed. To start out testing, a Kessler DCP K-100 cone penetrometer was used to provide a consistent

  7. Determination and verification of a 2D pencil-beam kernel for a radiosurgery system with cones

    Energy Technology Data Exchange (ETDEWEB)

    Vargas-Verdesoto, Milton Xavier, E-mail: mxvv2003@hotmail.com [Centro Oncológico de Chihuahua, Hacienda de la Esperanza, Chihuahua, México (Mexico); Universidad Autónoma del Estado de México, Paseo Tollocan, Toluca, Edo. De México, México (Mexico); Álvarez-Romero, José Trinidad [SSDL, Instituto Nacional de Invesigaciones Nucleares, La Marquesa, Ocoyoacac, México (Mexico)

    2013-07-01

    The quality and correctness of dosimetric data of small fields in stereotactic radiosurgery (SRS) depends significantly on the election of the detector employed in the measurements. This work provides an independent method of verification of these data through the determination of a polyenergetic 2-dimensional pencil-beam kernel for a BrainLAB SRS system with cones, employing the deconvolution/convolution of a reference experimental off-axis ratio (OAR) profile (cone diameter c{sub 0} = 35 mm). The kernel in real space k{sub c{sub 0}}(r,z{sub 0}) is convolved with the ideal fluence Φ for the cones 7.5 to 35 mm in diameter to obtain the OAR profiles, and the total scatter factors, S{sub t}, which are compared with experimental values of the same quantities. The experimental OARs and S{sub t} factors are measured in water with a PTW 60003 diamond detector. Additionally, the reference OAR is corrected for beam divergence and spectral fluence fluctuations defining a function of boundary correction factors (BF). The BF and Φ functions are transformed to the conjugate space with the zeroth-order Hankel transform, appropriated to the radial symmetry of the cones. Therefore, the kernel in real space k{sub c{sub 0}}(r,z{sub 0}) is the inverse Hankel transform of the ratio of the Hankel transforms of BF and Φ. Finally, an uncertainty analysis according to the Guide to the Expression of Uncertainty in Measurement is carried out for 3 different values of k{sub c{sub 0}}(r,z{sub 0}). Calculated and measured OARs agree within the dose/distance-to-agreement criteria of 2%/0.12 mm; while, S{sub t} factors agree within 2%. This procedure supplies an independent method to validate the dosimetric data necessary to feed treatment planning systems for SRS with cones.

  8. Preservation of cone photoreceptors after a rapid yet transient degeneration and remodeling in cone-only Nrl−/− mouse retina

    Science.gov (United States)

    Roger, Jerome E; Ranganath, Keerthi; Zhao, Lian; Cojocaru, Radu I; Brooks, Matthew; Gotoh, Norimoto; Veleri, Shobi; Hiriyanna, Avinash; Rachel, Rivka A; Campos, Maria Mercedes; Fariss, Robert N; Wong, Wai T; Swaroop, Anand

    2012-01-01

    Cone photoreceptors are the primary initiator of visual transduction in the human retina. Dysfunction or death of rod photoreceptors precedes cone loss in many retinal and macular degenerative diseases, suggesting a rod-dependent trophic support for cone survival. Rod differentiation and homeostasis are dependent on the basic motif leucine zipper transcription factor NRL. The loss of Nrl (Nrl−/−) in mice results in a retina with predominantly S-opsin containing cones that exhibit molecular and functional characteristics of WT cones. Here we report that Nrl−/− retina undergoes a rapid but transient period of degeneration in early adulthood, with cone apoptosis, retinal detachment, alterations in retinal vessel structure, and activation and translocation of retinal microglia. However, cone degeneration stabilizes by four months of age, resulting in a thinner but intact outer nuclear layer with residual cones expressing S- and M-opsins and a preserved photopic ERG. At this stage, microglia translocate back to the inner retina and reacquire a quiescent morphology. Gene profiling analysis during the period of transient degeneration reveals misregulation of genes related to stress response and inflammation, implying their involvement in cone death. The Nrl−/− mouse illustrates the long-term viability of cones in the absence of rods and RPE defects in a rodless retina. We propose that Nrl−/− retina may serve as a model for elucidating mechanisms of cone homeostasis and degeneration that would be relevant to understanding diseases of the cone-dominant human macula. PMID:22238088

  9. Eruptive and Geomorphic Processes at the Lathrop Wells Scoria Cone

    Energy Technology Data Exchange (ETDEWEB)

    G. Valentine; D.J. Krier; F.V. Perry; G. Heiken

    2006-08-03

    The {approx}80 ka Lathrop Wells volcano (southern Nevada, U.S.A.) preserves evidence for a range of explosive processes and emplacement mechanisms of pyroclastic deposits and lava fields in a small-volume basaltic center. Early cone building by Strombolian bursts was accompanied by development of a fan-like lava field reaching {approx}800 m distance from the cone, built upon a gently sloping surface. Lava flows carried rafts of cone deposits, which provide indirect evidence for cone facies in lieu of direct exposures in the active quarry. Subsequent activity was of a violent Strombolian nature, with many episodes of sustained eruption columns up to a few km in height. These deposited layers of scoria lapilli and ash in different directions depending upon wind direction at the time of a given episode, reaching up to {approx}20 km from the vent, and also produced the bulk of the scoria cone. Lava effusion migrated from south to north around the eastern base of the cone as accumulation of lavas successively reversed the topography at the base of the cone. Late lavas were emplaced during violent Strombolian activity and continued for some time after explosive eruptions had waned. Volumes of the eruptive products are: fallout--0.07 km{sup 3}, scoria cone--0.02 km{sup 3}, and lavas--0.03 km{sup 3}. Shallow-derived xenolith concentrations suggest an upper bound on average conduit diameter of {approx}21 m in the uppermost 335 m beneath the volcano. The volcano was constructed over a period of at least seven months with cone building occurring only during part of that time, based upon analogy with historical eruptions. Post-eruptive geomorphic evolution varied for the three main surface types that were produced by volcanic activity: (1) scoria cone, (2) low relief surfaces (including lavas) with abundant pyroclastic material, and (3) lavas with little pyroclastic material. The role of these different initial textures must be accounted for in estimating relative ages of

  10. Out-of-plane magnetized cone-shaped magnetic nanoshells

    Science.gov (United States)

    Ball, D. K.; Günther, S.; Fritzsche, M.; Lenz, K.; Varvaro, G.; Laureti, S.; Makarov, D.; Mücklich, A.; Facsko, S.; Albrecht, M.; Fassbender, J.

    2017-03-01

    The geometry of a magnetic nano-object, namely its shape and dimensions determines the complex electromagnetic responses. Here, we address the geometry-induced changes of the magnetic properties of thin ferromagnetic Co/Pd multilayers with out-of-plane magnetic anisotropy deposited on three-dimensionally curved templates. For this purpose, arrays of self-assembled cone-shaped nano-objects with a chracteristic size of either 30 or 70 nm were created in GaSb(0 0 1) by the ion erosion technique. The templates are designed in the way that the shape of the cone remains the same for all the samples; namely, we keep the opening angle at about 55° by adjusting the ratio between the cone height and its base diameter to be about 1. In this case, we are able to address the impact of the linear dimensions of the object on the magnetic properties and exclude the impact of the shape from the consideration. The deposition of 15 nm thick Co/Pd multilayers on top of the cone templates results in the formation of a close-packed array of 2D magnetic cone-shaped shells. Integral angle-dependent magnetometry measurements demonstrate that the local curvature results in the spread of the easy axes of magnetization following the shape of the nanocones independent of the linear dimensions of the cones. At the same time different local magnetic domain patterns are observed for samples prepared on 30 and 70 nm large cones. When the thickness of the magnetic shell is only half of the linear dimension of a cone, a clear multidomain state is observed. Remarkably, we find that the neighboring magnetic cone-shaped shells are exchange decoupled when the linear dimension of a cone is four times larger compared to the thickness of the magnetic shell. These findings are relevant for the further development of tilted bit patterned magnetic recording media as well as for the emergent field of magnetism in curved geometries.

  11. Eruptive and Geomorphic Processes at the Lathrop Wells Scoria Cone

    International Nuclear Information System (INIS)

    G. Valentine; D.J. Krier; F.V. Perry; G. Heiken

    2006-01-01

    The ∼80 ka Lathrop Wells volcano (southern Nevada, U.S.A.) preserves evidence for a range of explosive processes and emplacement mechanisms of pyroclastic deposits and lava fields in a small-volume basaltic center. Early cone building by Strombolian bursts was accompanied by development of a fan-like lava field reaching ∼800 m distance from the cone, built upon a gently sloping surface. Lava flows carried rafts of cone deposits, which provide indirect evidence for cone facies in lieu of direct exposures in the active quarry. Subsequent activity was of a violent Strombolian nature, with many episodes of sustained eruption columns up to a few km in height. These deposited layers of scoria lapilli and ash in different directions depending upon wind direction at the time of a given episode, reaching up to ∼20 km from the vent, and also produced the bulk of the scoria cone. Lava effusion migrated from south to north around the eastern base of the cone as accumulation of lavas successively reversed the topography at the base of the cone. Late lavas were emplaced during violent Strombolian activity and continued for some time after explosive eruptions had waned. Volumes of the eruptive products are: fallout--0.07 km 3 , scoria cone--0.02 km 3 , and lavas--0.03 km 3 . Shallow-derived xenolith concentrations suggest an upper bound on average conduit diameter of ∼21 m in the uppermost 335 m beneath the volcano. The volcano was constructed over a period of at least seven months with cone building occurring only during part of that time, based upon analogy with historical eruptions. Post-eruptive geomorphic evolution varied for the three main surface types that were produced by volcanic activity: (1) scoria cone, (2) low relief surfaces (including lavas) with abundant pyroclastic material, and (3) lavas with little pyroclastic material. The role of these different initial textures must be accounted for in estimating relative ages of volcanic surfaces, and failure to

  12. Automatic segmentation of maxillofacial cysts in cone beam CT images.

    Science.gov (United States)

    Abdolali, Fatemeh; Zoroofi, Reza Aghaeizadeh; Otake, Yoshito; Sato, Yoshinobu

    2016-05-01

    Accurate segmentation of cysts and tumors is an essential step for diagnosis, monitoring and planning therapeutic intervention. This task is usually done manually, however manual identification and segmentation is tedious. In this paper, an automatic method based on asymmetry analysis is proposed which is general enough to segment various types of jaw cysts. The key observation underlying this approach is that normal head and face structure is roughly symmetric with respect to midsagittal plane: the left part and the right part can be divided equally by an axis of symmetry. Cysts and tumors typically disturb this symmetry. The proposed approach consists of three main steps as follows: At first, diffusion filtering is used for preprocessing and symmetric axis is detected. Then, each image is divided into two parts. In the second stage, free form deformation (FFD) is used to correct slight displacement of corresponding pixels of the left part and a reflected copy of the right part. In the final stage, intensity differences are analyzed and a number of constraints are enforced to remove false positive regions. The proposed method has been validated on 97 Cone Beam Computed Tomography (CBCT) sets containing various jaw cysts which were collected from various image acquisition centers. Validation is performed using three similarity indicators (Jaccard index, Dice's coefficient and Hausdorff distance). The mean Dice's coefficient of 0.83, 0.87 and 0.80 is achieved for Radicular, Dentigerous and KCOT classes, respectively. For most of the experiments done, we achieved high true positive (TP). This means that a large number of cyst pixels are correctly classified. Quantitative results of automatic segmentation show that the proposed method is more effective than one of the recent methods in the literature. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Final Report

    DEFF Research Database (Denmark)

    Heiselberg, Per; Brohus, Henrik; Nielsen, Peter V.

    This final report for the Hybrid Ventilation Centre at Aalborg University describes the activities and research achievement in the project period from August 2001 to August 2006. The report summarises the work performed and the results achieved with reference to articles and reports published...

  14. An Analysis Model for Water Cone Subsidence in Bottom Water Drive Reservoirs

    Science.gov (United States)

    Wang, Jianjun; Xu, Hui; Wu, Shucheng; Yang, Chao; Kong, lingxiao; Zeng, Baoquan; Xu, Haixia; Qu, Tailai

    2017-12-01

    Water coning in bottom water drive reservoirs, which will result in earlier water breakthrough, rapid increase in water cut and low recovery level, has drawn tremendous attention in petroleum engineering field. As one simple and effective method to inhibit bottom water coning, shut-in coning control is usually preferred in oilfield to control the water cone and furthermore to enhance economic performance. However, most of the water coning researchers just have been done on investigation of the coning behavior as it grows up, the reported studies for water cone subsidence are very scarce. The goal of this work is to present an analytical model for water cone subsidence to analyze the subsidence of water cone when the well shut in. Based on Dupuit critical oil production rate formula, an analytical model is developed to estimate the initial water cone shape at the point of critical drawdown. Then, with the initial water cone shape equation, we propose an analysis model for water cone subsidence in bottom water reservoir reservoirs. Model analysis and several sensitivity studies are conducted. This work presents accurate and fast analytical model to perform the water cone subsidence in bottom water drive reservoirs. To consider the recent interests in development of bottom drive reservoirs, our approach provides a promising technique for better understanding the subsidence of water cone.

  15. Impact of cone-beam computed tomography on implant planning and on prediction of implant size

    Energy Technology Data Exchange (ETDEWEB)

    Pedroso, Ludmila Assuncao de Mello; Silva, Maria Alves Garcia Santos, E-mail: ludmilapedroso@hotmail.com [Universidade Federal de Goias (UFG), Goiania, GO (Brazil). Fac. de Odontologia; Garcia, Robson Rodrigues [Universidade Federal de Goias (UFG), Goiania, GO (Brazil). Fac. de Odontologia. Dept. de Medicina Oral; Leles, Jose Luiz Rodrigues [Universidade Paulista (UNIP), Goiania, GO (Brazil). Fac. de Odontologia. Dept. de Cirurgia; Leles, Claudio Rodrigues [Universidade Federal de Goias (UFG), Goiania, GO (Brazil). Fac. de Odontologia. Dept. de Prevencao e Reabilitacao Oral

    2013-11-15

    The aim was to investigate the impact of cone-beam computed tomography (CBCT) on implant planning and on prediction of final implant size. Consecutive patients referred for implant treatment were submitted to clinical examination, panoramic (PAN) radiography and a CBCT exam. Initial planning of implant length and width was assessed based on clinical and PAN exams, and final planning, on CBCT exam to complement diagnosis. The actual dimensions of the implants placed during surgery were compared with those obtained during initial and final planning, using the McNemmar test (p < 0.05). The final sample comprised 95 implants in 27 patients, distributed over the maxilla and mandible. Agreement in implant length was 50.5% between initial and final planning, and correct prediction of the actual implant length was 40.0% and 69.5%, using PAN and CBCT exams, respectively. Agreement in implant width assessment ranged from 69.5% to 73.7%. A paired comparison of the frequency of changes between initial or final planning and implant placement (McNemmar test) showed greater frequency of changes in initial planning for implant length (p < 0.001), but not for implant width (p = 0.850). The frequency of changes was not influenced by implant location at any stage of implant planning (chi-square test, p > 0.05). It was concluded that CBCT improves the ability of predicting the actual implant length and reduces inaccuracy in surgical dental implant planning. (author)

  16. Méthode analytique généralisée pour le calcul du coning. Nouvelle solution pour calculer le coning de gaz, d'eau et double coning dans les puits verticaux et horizontaux Generalized Analytical Method for Coning Calculation. New Solution to Calculation Both the Gas Coning, Water Coning and Dual Coning for Vertical and Horizontal Wells

    Directory of Open Access Journals (Sweden)

    Pietraru V.

    2006-11-01

    Full Text Available Une nouvelle méthode analytique d'évaluation du coning d'eau par bottom water drive et/ou de gaz par gas-cap drive dans les puits horizontaux et verticaux a été développée pour les réservoirs infinis [1]. Dans cet article, une généralisation de cette méthode est présentée pour les réservoirs confinés d'extension limitée dont le toit est horizontal. La généralisation proposée est basée sur la résolution des équations différentielles de la diffusivité avec prise en compte des effets de drainage par gravité et des conditions aux limites pour un réservoir confiné. La méthode est applicable aux réservoirs isotropes ou anisotropes. L'hypothèse de pression constante à la limite de l'aire de drainage dans l'eau et/ou dans le gaz a été adoptée. Les pertes de charge dans l'aquifère et dans le gas-cap sont donc négligées. Les principales contributions de cet article sont : - L'introduction de la notion de rayon de cône, différent du rayon de puits. La hauteur du cône et le débit critique dépendent du rayon de cône alors qu'ils sont indépendants du rayon du puits. - Une nouvelle corrélation pour le calcul du débit critique sous forme adimensionnelle en fonction de trois paramètres : le temps, la longueur du drain horizontal (nulle pour un puits vertical et le rayon de drainage. - Des corrélations pour le calcul du rapport des débits gaz/huile (GOR ou de la fraction en eau (fw, pendant les périodes critique et postcritique, qui tiennent compte de la pression capillaire et des perméabilités relatives. - Des corrélations pour le calcul des rapports de débits gaz/huile et eau/huile pendant les périodes pré, post et supercritique en double coning. - Des critères pour le calcul du temps de percée au puits en simple coning de gaz ou d'eau, ou en double coning de gaz et d'eau. A new analytical method for assessing water and/or gas coning in horizontal and vertical wells has been developed for infinite

  17. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Stinis, Panos [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-08-07

    This is the final report for the work conducted at the University of Minnesota (during the period 12/01/12-09/18/14) by PI Panos Stinis as part of the "Collaboratory on Mathematics for Mesoscopic Modeling of Materials" (CM4). CM4 is a multi-institution DOE-funded project whose aim is to conduct basic and applied research in the emerging field of mesoscopic modeling of materials.

  18. Elovl4 5-bp deletion does not accelerate cone photoreceptor degeneration in an all-cone mouse.

    Directory of Open Access Journals (Sweden)

    Christian Schori

    Full Text Available Mutations in the elongation of very long chain fatty acid 4 (ELOVL4 gene cause Stargardt macular dystrophy 3 (STGD3, a rare, juvenile-onset, autosomal dominant form of macular degeneration. Although several mouse models have already been generated to investigate the link between the three identified disease-causing mutations in the ELOVL4 gene, none of these models recapitulates the early-onset cone photoreceptor cell death observed in the macula of STGD3 patients. To address this specifically, we investigated the effect of mutant ELOVL4 in a mouse model with an all-cone retina. Hence, we bred mice carrying the heterozygously mutated Elovl4 gene on the R91W;Nrl-/- all-cone background and analyzed the retinal lipid composition, morphology, and function over the course of 1 year. We observed a reduction of total phosphatidylcholine-containing very long chain-polyunsaturated fatty acids (PC-VLC-PUFAs by 39% in the R91W;Nrl-/-;Elovl4 mice already at 6 weeks of age with a pronounced decline of the longest forms of PC-VLC-PUFAs. Total levels of shorter-chain fatty acids (< C26 remained unaffected. However, this reduction in PC-VLC-PUFA content in the all-cone retina had no impact on morphology or function and did not accelerate retinal degeneration in the R91W;Nrl-/-;Elovl4 mice. Taken together, mutations in the ELOVL4 gene lead to cone degeneration in humans, whereas mouse models expressing the mutant Elovl4 show predominant rod degeneration. The lack of a phenotype in the all-cone retina expressing the mutant form of the protein supports the view that aberrant function of ELOVL4 is especially detrimental for rods in mice and suggests a more subtle role of VLC-PUFAs for cone maintenance and survival.

  19. Pollen cone anatomy of Classostrobus crossii sp. nov. (Cheirolepidiaceae)

    Energy Technology Data Exchange (ETDEWEB)

    Rothwell, Gar W.; Mapes, Gene [Department of Environmental and Plant Biology, Ohio University, Athens OH 45701 (United States); Hilton, Jason [Department of Earth Sciences, School of Geography, Earth and Environmental Sciences, The University of Birmingham, Edgbaston, Birmingham, B15 2TT (United Kingdom); Hollingworth, Neville T. [Centre for Ecology and Hydrology, Winfrith Technology Centre, Winfrith Newburgh, Dorchester, Dorset, DT2 8ZD (United Kingdom)

    2007-01-02

    Discovery of a permineralized fossil cone in Mesozoic deposits of southern England provides an opportunity to document the first detailed evidence of internal pollen cone anatomy for the extinct conifer family Cheirolepidiaceae. The specimen, described here as Classostrobus crossii sp. nov., occurs in a calcareous nodule recovered from Middle Jurassic marine sediments of the Lower Callovian Sigaloceras calloviense biozone, Kellaways, near Cirencester, England. The cone is 2.0 cm long and 1.8 cm wide. Sporophylls diverge helically from the axis. Each sporophyll displays a narrow stalk and a distal lamina approx. 11 mm long that tapers to a pointed tip. There is also a basal keel that bends inward at the bottom and sides to form a shallow pocket. A single vascular bundle diverges from the cone axis, extends distally into the sporophyll stalk at the contact of two distinctly different histological zones, and further expands into the distal lamina as transfusion tracheids. Several pollen sacs are attached abaxially at the juncture of the sporophyll stalk and keel. Pollen is roughly spheroidal, 26-35 {mu}m in diameter, with unequal polar caps separated by a striated belt with a subequatorial furrow. This specimen helps clarify the range of variation in the morphology of Mesozoic conifer pollen cones. (author)

  20. Venomics-Accelerated Cone Snail Venom Peptide Discovery.

    Science.gov (United States)

    Himaya, S W A; Lewis, Richard J

    2018-03-09

    Cone snail venoms are considered a treasure trove of bioactive peptides. Despite over 800 species of cone snails being known, each producing over 1000 venom peptides, only about 150 unique venom peptides are structurally and functionally characterized. To overcome the limitations of the traditional low-throughput bio-discovery approaches, multi-omics systems approaches have been introduced to accelerate venom peptide discovery and characterisation. This "venomic" approach is starting to unravel the full complexity of cone snail venoms and to provide new insights into their biology and evolution. The main challenge for venomics is the effective integration of transcriptomics, proteomics, and pharmacological data and the efficient analysis of big datasets. Novel database search tools and visualisation techniques are now being introduced that facilitate data exploration, with ongoing advances in related omics fields being expected to further enhance venomics studies. Despite these challenges and future opportunities, cone snail venomics has already exponentially expanded the number of novel venom peptide sequences identified from the species investigated, although most novel conotoxins remain to be pharmacologically characterised. Therefore, efficient high-throughput peptide production systems and/or banks of miniaturized discovery assays are required to overcome this bottleneck and thus enhance cone snail venom bioprospecting and accelerate the identification of novel drug leads.

  1. Generalized Fourier slice theorem for cone-beam image reconstruction.

    Science.gov (United States)

    Zhao, Shuang-Ren; Jiang, Dazong; Yang, Kevin; Yang, Kang

    2015-01-01

    The cone-beam reconstruction theory has been proposed by Kirillov in 1961, Tuy in 1983, Feldkamp in 1984, Smith in 1985, Pierre Grangeat in 1990. The Fourier slice theorem is proposed by Bracewell 1956, which leads to the Fourier image reconstruction method for parallel-beam geometry. The Fourier slice theorem is extended to fan-beam geometry by Zhao in 1993 and 1995. By combining the above mentioned cone-beam image reconstruction theory and the above mentioned Fourier slice theory of fan-beam geometry, the Fourier slice theorem in cone-beam geometry is proposed by Zhao 1995 in short conference publication. This article offers the details of the derivation and implementation of this Fourier slice theorem for cone-beam geometry. Especially the problem of the reconstruction from Fourier domain has been overcome, which is that the value of in the origin of Fourier space is 0/0. The 0/0 type of limit is proper handled. As examples, the implementation results for the single circle and two perpendicular circle source orbits are shown. In the cone-beam reconstruction if a interpolation process is considered, the number of the calculations for the generalized Fourier slice theorem algorithm is O(N^4), which is close to the filtered back-projection method, here N is the image size of 1-dimension. However the interpolation process can be avoid, in that case the number of the calculations is O(N5).

  2. The photocurrent response of human cones is fast and monophasic

    Directory of Open Access Journals (Sweden)

    Lamb TD

    2006-04-01

    Full Text Available Abstract Background The precise form of the light response of human cone photoreceptors in vivo has not been established with certainty. To investigate the response shape we compare the predictions of a recent model of transduction in primate cone photoreceptors with measurements extracted from human cones using the paired-flash electroretinogram method. As a check, we also compare the predictions with previous single-cell measurements of ground squirrel cone responses. Results The predictions of the model provide a good description of the measurements, using values of parameters within the range previously determined for primate retina. The dim-flash response peaks in about 20 ms, and flash responses at all intensities are essentially monophasic. Three time constants in the model are extremely short: the two time constants for inactivation (of visual pigment and of transducin/phosphodiesterase are around 3 and 10 ms, and the time constant for calcium equilibration lies in the same range. Conclusion The close correspondence between experiment and theory, using parameters previously derived for recordings from macaque retina, supports the notion that the electroretinogram approach and the modelling approach both provide an accurate estimate of the cone photoresponse in the living human eye. For reasons that remain unclear, the responses of isolated photoreceptors from the macaque retina, recorded previously using the suction pipette method, are considerably slower than found here, and display biphasic kinetics.

  3. Venomics-Accelerated Cone Snail Venom Peptide Discovery

    Science.gov (United States)

    Himaya, S. W. A.

    2018-01-01

    Cone snail venoms are considered a treasure trove of bioactive peptides. Despite over 800 species of cone snails being known, each producing over 1000 venom peptides, only about 150 unique venom peptides are structurally and functionally characterized. To overcome the limitations of the traditional low-throughput bio-discovery approaches, multi-omics systems approaches have been introduced to accelerate venom peptide discovery and characterisation. This “venomic” approach is starting to unravel the full complexity of cone snail venoms and to provide new insights into their biology and evolution. The main challenge for venomics is the effective integration of transcriptomics, proteomics, and pharmacological data and the efficient analysis of big datasets. Novel database search tools and visualisation techniques are now being introduced that facilitate data exploration, with ongoing advances in related omics fields being expected to further enhance venomics studies. Despite these challenges and future opportunities, cone snail venomics has already exponentially expanded the number of novel venom peptide sequences identified from the species investigated, although most novel conotoxins remain to be pharmacologically characterised. Therefore, efficient high-throughput peptide production systems and/or banks of miniaturized discovery assays are required to overcome this bottleneck and thus enhance cone snail venom bioprospecting and accelerate the identification of novel drug leads. PMID:29522462

  4. Venomics-Accelerated Cone Snail Venom Peptide Discovery

    Directory of Open Access Journals (Sweden)

    S. W. A. Himaya

    2018-03-01

    Full Text Available Cone snail venoms are considered a treasure trove of bioactive peptides. Despite over 800 species of cone snails being known, each producing over 1000 venom peptides, only about 150 unique venom peptides are structurally and functionally characterized. To overcome the limitations of the traditional low-throughput bio-discovery approaches, multi-omics systems approaches have been introduced to accelerate venom peptide discovery and characterisation. This “venomic” approach is starting to unravel the full complexity of cone snail venoms and to provide new insights into their biology and evolution. The main challenge for venomics is the effective integration of transcriptomics, proteomics, and pharmacological data and the efficient analysis of big datasets. Novel database search tools and visualisation techniques are now being introduced that facilitate data exploration, with ongoing advances in related omics fields being expected to further enhance venomics studies. Despite these challenges and future opportunities, cone snail venomics has already exponentially expanded the number of novel venom peptide sequences identified from the species investigated, although most novel conotoxins remain to be pharmacologically characterised. Therefore, efficient high-throughput peptide production systems and/or banks of miniaturized discovery assays are required to overcome this bottleneck and thus enhance cone snail venom bioprospecting and accelerate the identification of novel drug leads.

  5. Large Scale Plasmonic nanoCones array For Spectroscopy Detection

    KAUST Repository

    Das, Gobind

    2015-09-24

    Advanced optical materials or interfaces are gaining attention for diagnostic applications. However, the achievement of large device interface as well as facile surface functionalization largely impairs their wide use. The present work is aimed to address different innovative aspects related to the fabrication of large area 3D plasmonic arrays, their direct and easy functionalization with capture elements and their spectroscopic verifications through enhanced Raman and enhanced fluorescence techniques. In detail we have investigated the effect of Au-based nanoCones array, fabricated by means of direct nanoimprint technique over large area (mm2), on protein capturing and on the enhancement in optical signal. A selective functionalization of gold surfaces was proposed by using a peptide (AuPi3) previously selected by phage display. In this regard, two different sequences, labeled with fluorescein and biotin, were chemisorbed on metallic surfaces. The presence of Au nanoCones array consents an enhancement in electric field on the apex of cone, enabling the detection of molecules. We have witnessed around 12-fold increase in fluorescence intensity and SERS enhancement factor around 1.75 ×105 with respect to the flat gold surface. Furthermore, a sharp decrease in fluorescence lifetime over nanoCones confirms the increase in radiative emission (i.e. an increase in photonics density at the apex of cones).

  6. Exact cone beam CT with a spiral scan

    International Nuclear Information System (INIS)

    Tam, K.C.; Samarasekera, S.; Sauer, F.

    1998-01-01

    A method is developed which makes it possible to scan and reconstruct an object with cone beam x-rays in a spiral scan path with area detectors much shorter than the length of the object. The method is mathematically exact. If only a region of interest of the object is to be imaged, a top circle scan at the top level of the region of interest and a bottom circle scan at the bottom level of the region of interest are added. The height of the detector is required to cover only the distance between adjacent turns in the spiral projected at the detector. To reconstruct the object, the Radon transform for each plane intersecting the object is computed from the totality of the cone beam data. This is achieved by suitably combining the cone beam data taken at different source positions on the scan path; the angular range of the cone beam data required at each source position can be determined easily with a mask which is the spiral scan path projected on the detector from the current source position. The spiral scan algorithm has been successfully validated with simulated cone beam data. (author)

  7. Spray cone angle and air core diameter of hollow cone swirl rocket injector

    Directory of Open Access Journals (Sweden)

    Ahmad Hussein Abdul Hamid

    2011-12-01

    Full Text Available ABSTRACT : Fuel injector for liquid rocket is a very critical component since that small difference in its design can dramatically affect the combustion efficiency. The primary function of the injector is to break the fuel up into very small droplets. The smaller droplets are necessary for fast quiet ignition and to establish a flame front close to the injector head, thus shorter combustion chamber is possible to be utilized. This paper presents an experimetal investigation of a mono-propellant hollow cone swirl injector. Several injectors with different configuration were investigated under cold flow test, where water is used as simulation fluid. This investigation reveals that higher injection pressure leads to higher spray cone angle. The effect of injection pressure on spray cone angle is more prominent for injector with least number of tangential ports. Furthermore, it was found that injector with the most number of tangential ports and with the smallest tangential port diameter produces the widest resulting spray. Experimental data also tells that the diameter of an air core that forms inside the swirl chamber is largest for the injector with smallest tangential port diameter and least number of tangential ports.ABSTRAK : Injektor bahan api bagi roket cecair merupakan satu komponen yang amat kritikal memandangkan perbezaan kecil dalam reka bentuknya akan secara langsung mempengaruhi kecekapan pembakaran. Fungsi utama injektor adalah untuk memecahkan bahan api kepada titisan yang amat kecil. Titisan kecil penting untuk pembakaran pantas secara senyap dan untuk mewujudkan satu nyalaan di hadapan, berhampiran dengan kepala injektor, maka kebuk pembakaran yang lebih pendek berkemungkinan dapat digunakan. Kertas kerja ini mebentangkan satu penyelidikan eksperimental sebuah injektor ekabahan dorong geronggang kon pusar. Beberapa injektor dengan konfigurasi berbeza telah dikaji di bawah ujian aliran sejuk, di mana air digunakan sebagai bendalir

  8. M2-branes on orbifolds of the cone over Q1,1,1

    International Nuclear Information System (INIS)

    Franco, Sebastian; Klebanov, Igor R.; RodrIguez-Gomez, Diego

    2009-01-01

    We study the N = 2 supersymmetric Chern-Simons quiver gauge theory recently introduced in arXiv:0809.3237 to describe M2-branes on a cone over the well-known Sasaki-Einstein manifold Q 1,1,1 . For Chern-Simons levels (k,k,-k,-k) we argue that this theory is dual to AdS 4 x Q 1,1,1 /Z k . We derive the Z k orbifold action and show that it preserves geometrical symmetry U(1) R x SU(2) x U(1), in agreement with the symmetry of the gauge theory. We analyze the simplest gauge invariant chiral operators, and show that they match Kaluza-Klein harmonics on AdS 4 x Q 1,1,1 /Z k . This provides a test of the gauge theory, and in particular of its sextic superpotential which plays an important role in restricting the spectrum of chiral operators. We proceed to study other quiver gauge theories corresponding to more complicated orbifolds of Q 1,1,1 . In particular, we propose two U(N) 4 Chern-Simons gauge theories whose quiver diagrams are the same as in the 4d theories describing D3-branes on a complex cone over F 0 , a Z 2 orbifold of the conifold (in 4d the two quivers are related by the Seiberg duality). The manifest symmetry of these gauge theories is U(1) R x SU(2) x SU(2). We argue that these gauge theories at levels (k,k,-k,-k) are dual to AdS 4 x Q 2,2,2 /Z k . We exhibit calculations of the moduli space and of the chiral operator spectrum which provide support for this conjecture. We also briefly discuss a similar correspondence for AdS 4 x M 3,2 /Z k . Finally, we discuss resolutions of the cones and their dual gauge theories.

  9. Region-of-interest reconstruction for a cone-beam dental CT with a circular trajectory

    International Nuclear Information System (INIS)

    Hu, Zhanli; Zou, Jing; Gui, Jianbao; Zheng, Hairong; Xia, Dan

    2013-01-01

    Dental CT is the most appropriate and accurate device for preoperative evaluation of dental implantation. It can demonstrate the quantity of bone in three dimensions (3D), the location of important adjacent anatomic structures and the quality of available bone with minimal geometric distortion. Nevertheless, with the rapid increase of dental CT examinations, we are facing the problem of dose reduction without loss of image quality. In this work, backprojection-filtration (BPF) and Feldkamp–Davis–Kress (FDK) algorithm was applied to reconstruct the 3D full image and region-of-interest (ROI) image from complete and truncated circular cone-beam data respectively by computer-simulation. In addition, the BPF algorithm was evaluated based on the 3D ROI-image reconstruction from real data, which was acquired from our developed circular cone-beam prototype dental CT system. The results demonstrated that the ROI-image quality reconstructed from truncated data using the BPF algorithm was comparable to that reconstructed from complete data. The FDK algorithm, however, created artifacts while reconstructing ROI-image. Thus it can be seen, for circular cone-beam dental CT, reducing scanning angular range of the BPF algorithm used for ROI-image reconstruction are helpful for reducing the radiation dose and scanning time. Finally, an analytical method was developed for estimation of the ROI projection area on the detector before CT scanning, which would help doctors to roughly estimate the total radiation dose before the CT examination. -- Highlights: ► BPF algorithm was applied by using dental CT for the first time. ► A method was developed for estimation of projection region before CT scanning. ► Roughly predict the total radiation dose before CT scans. ► Potential reduce imaging radiation dose, scatter, and scanning time

  10. Lentes progressivas x lentes multifocais: um estudo baseado na geometria analítica do cone

    Directory of Open Access Journals (Sweden)

    Araújo Marília Cavalcante

    2004-01-01

    Full Text Available OBJETIVO: Compreender, por meio de figuras e funções matemáticas do cone, as lentes progressivas e mostrar que elas não são lentes multifocais porque, nelas, a refração da luz não obedece as leis da geometria euclidiana. MÉTODOS: Foi feito um estudo da geometria analítica do cone, com o programa de computador Auto-CAD 14, dando enfoque óptico às figuras geométricas obtidas com a sua secção. RESULTADOS: Pela análise das figuras obtidas da secção do cone, pudemos observar as superfícies que compõem as lentes progressivas. Estas superfícies são compostas de elipse, círculo, parábola e hipérbole. Diferente do que é dito na literatura, encontramos as elipses com diâmetro maior nas ordenadas e de mesmo sentido seguida por duas superfícies inferiores que são parábola e hipérbole e não o contrário. CONCLUSÕES: As lentes progressivas diferentemente das lentes multifocais apresentam prismas nos centros ópticos como decorrência da sua estrutura. No final, fizemos análise das suas formas mostrando o limite teórico da sua evolução.

  11. Retinal cone photoreceptors of the deer mouse Peromyscus maniculatus: development, topography, opsin expression and spectral tuning.

    Directory of Open Access Journals (Sweden)

    Patrick Arbogast

    Full Text Available A quantitative analysis of photoreceptor properties was performed in the retina of the nocturnal deer mouse, Peromyscus maniculatus, using pigmented (wildtype and albino animals. The aim was to establish whether the deer mouse is a more suitable model species than the house mouse for photoreceptor studies, and whether oculocutaneous albinism affects its photoreceptor properties. In retinal flatmounts, cone photoreceptors were identified by opsin immunostaining, and their numbers, spectral types, and distributions across the retina were determined. Rod photoreceptors were counted using differential interference contrast microscopy. Pigmented P. maniculatus have a rod-dominated retina with rod densities of about 450.000/mm(2 and cone densities of 3000-6500/mm(2. Two cone opsins, shortwave sensitive (S and middle-to-longwave sensitive (M, are present and expressed in distinct cone types. Partial sequencing of the S opsin gene strongly supports UV sensitivity of the S cone visual pigment. The S cones constitute a 5-15% minority of the cones. Different from house mouse, S and M cone distributions do not have dorsoventral gradients, and coexpression of both opsins in single cones is exceptional (<2% of the cones. In albino P. maniculatus, rod densities are reduced by approximately 40% (270.000/mm(2. Overall, cone density and the density of cones exclusively expressing S opsin are not significantly different from pigmented P. maniculatus. However, in albino retinas S opsin is coexpressed with M opsin in 60-90% of the cones and therefore the population of cones expressing only M opsin is significantly reduced to 5-25%. In conclusion, deer mouse cone properties largely conform to the general mammalian pattern, hence the deer mouse may be better suited than the house mouse for the study of certain basic cone properties, including the effects of albinism on cone opsin expression.

  12. Conclusiones finales

    OpenAIRE

    Guerrero Gaitán, Manuel

    2016-01-01

    La investigación realizada permite extraer las siguientes conclusiones finales que serán agrupadas según los principales problemas abordados: 1. En relación a las cláusulas que impiden una adecuada transferencia de tecnología, en la presente investigación se demuestra: Primero. Que las cláusulas más frecuentes recogidas en los contratos internacionales de transferencia de tecnología son: la fijación de precios, las restricciones a la investigación y adaptación de la tecnología objeto del cont...

  13. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    R Paul Drake

    2004-01-12

    OAK-B135 This is the final report from the project Hydrodynamics by High-Energy-Density Plasma Flow and Hydrodynamics and Radiation Hydrodynamics with Astrophysical Applications. This project supported a group at the University of Michigan in the invention, design, performance, and analysis of experiments using high-energy-density research facilities. The experiments explored compressible nonlinear hydrodynamics, in particular at decelerating interfaces, and the radiation hydrodynamics of strong shock waves. It has application to supernovae, astrophysical jets, shock-cloud interactions, and radiative shock waves.

  14. SU-F-J-205: Effect of Cone Beam Factor On Cone Beam CT Number Accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Yao, W; Hua, C; Farr, J; Brady, S; Merchant, T [St. Jude Children’s Research Hospital, Memphis, TN (United States)

    2016-06-15

    Purpose: To examine the suitability of a Catphan™ 700 phantom for image quality QA of a cone beam computed tomography (CBCT) system deployed for proton therapy. Methods: Catphan phantoms, particularly Catphan™ 504, are commonly used in image quality QA for CBCT. As a newer product, Catphan™ 700 offers more tissue equivalent inserts which may be useful for generating the electron density – CT number curve for CBCT based treatment planning. The sensitometry-and-geometry module used in Catphan™ 700 is located at the end of the phantom and after the resolution line pair module. In Catphan™ 504 the line pair module is located at the end of the phantom and after the sensitometry-and-geometry module. To investigate the effect of difference in location on CT number accuracy due to the cone beam factor, we scanned the Catphan™ 700 with the central plane of CBCT at the center of the phantom, line pair and sensitometry-andgeometry modules of the phantom, respectively. The protocol head and thorax scan modes were used. For each position, scans were repeated 4 times. Results: For the head scan mode, the standard deviation (SD) of the CT numbers of each insert under 4 repeated scans was up to 20 HU, 11 HU, and 11 HU, respectively, for the central plane of CBCT located at the center of the phantom, line pair, and sensitometry-and-geometry modules of the phantom. The mean of the SD was 9.9 HU, 5.7 HU, and 5.9 HU, respectively. For the thorax mode, the mean of the SD was 4.5 HU, 4.4 HU, and 4.4 HU, respectively. The assessment of image quality based on resolution and spatial linearity was not affected by imaging location changes. Conclusion: When the Catphan™ 700 was aligned to the center of imaging region, the CT number accuracy test may not meet expectations. We recommend reconfiguration of the modules.

  15. String/flux tube duality on the light cone

    International Nuclear Information System (INIS)

    Brower, Richard C.; Tan, C.-I; Thorn, Charles B.

    2006-01-01

    The equivalence of quantum field theory and string theory as exemplified by the AdS/CFT correspondence is explored from the point of view of light cone quantization. On the string side we discuss the light cone version of the static string connecting a heavy external quark source to a heavy external antiquark source, together with small oscillations about the static string configuration. On the field theory side we analyze the weak/strong coupling transition in a ladder diagram model of the quark-antiquark system, also from the point of view of the light cone. Our results are completely consistent with those obtained by more standard covariant methods in the limit of infinitely massive quarks

  16. Concrescence: Cone-Beam Computed Tomography Imaging Perspective

    Directory of Open Access Journals (Sweden)

    Ali Zakir Syed

    2016-01-01

    Full Text Available Concrescence is a form of twinning, formed by the confluence of cementum of two teeth at the root level. The diagnosis of concrescence has largely relied on the conventional 2D imaging. The 2D imaging has inherent limitations such as distortion and superimposition. Cone-Beam CT eliminates these limitations. The aim of this article was to describe a case of dental abnormality using Cone-Beam CT imaging modality. Volumetric data demonstrated confluence of left mandibular third molar with a paramolar, a supernumerary tooth. To our knowledge, this is the second case in the dental literature reported demonstrating the use of Cone-Beam CT in the diagnosis of concrescence.

  17. Effect of inlet cone pipe angle in catalytic converter

    Science.gov (United States)

    Amira Zainal, Nurul; Farhain Azmi, Ezzatul; Arifin Samad, Mohd

    2018-03-01

    The catalytic converter shows significant consequence to improve the performance of the vehicle start from it launched into production. Nowadays, the geometric design of the catalytic converter has become critical to avoid the behavior of backpressure in the exhaust system. The backpressure essentially reduced the performance of vehicles and increased the fuel consumption gradually. Consequently, this study aims to design various models of catalytic converter and optimize the volume of fluid flow inside the catalytic converter by changing the inlet cone pipe angles. Three different geometry angles of the inlet cone pipe of the catalytic converter were assessed. The model is simulated in Solidworks software to determine the optimum geometric design of the catalytic converter. The result showed that by decreasing the divergence angle of inlet cone pipe will upsurge the performance of the catalytic converter.

  18. An ice-cream cone model for coronal mass ejections

    Science.gov (United States)

    Xue, X. H.; Wang, C. B.; Dou, X. K.

    2005-08-01

    In this study, we use an ice-cream cone model to analyze the geometrical and kinematical properties of the coronal mass ejections (CMEs). Assuming that in the early phase CMEs propagate with near-constant speed and angular width, some useful properties of CMEs, namely the radial speed (v), the angular width (α), and the location at the heliosphere, can be obtained considering the geometrical shapes of a CME as an ice-cream cone. This model is improved by (1) using an ice-cream cone to show the near real configuration of a CME, (2) determining the radial speed via fitting the projected speeds calculated from the height-time relation in different azimuthal angles, (3) not only applying to halo CMEs but also applying to nonhalo CMEs.

  19. Loss-cone-driven ion cyclotron waves in the magnetosphere

    International Nuclear Information System (INIS)

    Denton, R.E.; Hudson, M.K.; Roth, I.

    1992-01-01

    The theoretical properties of linear ion cyclotron waves propagating in the magnetosphere at arbitrary angles to the background magnetic field are explored. It is found that in some cases the linear wave growth of modes with oblique propagation can dominate that of the parallel propagating electromagnetic ion cyclotron (EMIC) wave. In particular, when the hot ring current protons have a loss cone and their temperature anisotropy A ≡ T perpendicular /T parallel - 1 is reduced, the parallel propagating EMIC wave becomes stable, while the obliquely propagating loss-cone-driven mode persists. The growth rate of the loss-cone-driven model depends strongly on the depth of the loss cone. Unlike the parallel propagating EMIC wave, it can be unstable with A = 0. Other conditions that favor the loss-cone-driven mode in comparison to the parallel mode are stronger background magnetic field, lower density of cold hydrogen, and a lower temperature for the hot anisotropic component of hydrogen. A simple analytical theory is presented which explains the scaling of the growth rate of the oblique mode with respect to various parameters. The loss-cone-driven mode is an electromagnetic mode which is preferentially nearly linearly polarized. It is nearly electrostatic in the sense that the wave electric field is aligned with the perpendicular (to B 0 ) component of the wave vector k and k perpendicular > k parallel . Since the electric and magnetic wave fields are perpendicular to B 0 , they would be difficult to distinguish from those of a linearly polarized parallel propagating electromagnetic wave with the same k parallel

  20. Correlation of engineering parameters of the presumpscot formation to the seismic cone penetration test (SCPTU).

    Science.gov (United States)

    2015-08-01

    The seismic cone penetration test with pore pressure measurement (SCPTu) is a geotechnical investigation technique which : involves pushing a sensitized cone into the subsurface at a constant rate while continuously measuring tip resistance, sleeve :...

  1. Evaluation of cone penetration testing (CPT) for use with transportation projects.

    Science.gov (United States)

    2011-04-01

    Cone Penetration Testing (CPT) has many advantages as a means for subsurface investigation. CPT consists of pushing a steel : cone into the ground and recording the penetration resistance using sensors. Pore pressure, shear wave velocity and other : ...

  2. Light-cone quantized QCD and novel hadron phenomenology

    International Nuclear Information System (INIS)

    Brodsky, S.J.

    1997-09-01

    The authors reviews progress made in solving gauge theories such as collinear quantum chromodynamics using light-cone Hamiltonian methods. He also shows how the light-cone Fock expansion for hadron wavefunctions can be used to compute operator matrix elements such as decay amplitudes, form factors, distribution amplitudes, and structure functions, and how it provides a tool for exploring novel features of QCD. The author also reviews commensurate scale relations, leading-twist identities which relate physical observables to each other, thus eliminating renormalization scale and scheme ambiguities in perturbative QCD predictions

  3. Gauge-invariant correlation functions in light-cone superspace

    Science.gov (United States)

    Ananth, Sudarshan; Kovacs, Stefano; arikh, Sarthak

    2012-05-01

    We initiate a study of correlation functions of gauge-invariant operators in {N} = 4 super Yang-Mills theory using the light-cone superspace formalism. Our primary aim is to develop efficient methods to compute perturbative corrections to correlation functions. This analysis also allows us to examine potential subtleties which may arise when calculating off-shell quantities in light-cone gauge. We comment on the intriguing possibility that the manifest {N} = 4 supersymmetry in this approach may allow for a compact description of entire multiplets and their correlation functions.

  4. PVC Cable Fire Toxicity using the Cone Calorimeter

    OpenAIRE

    Al-Sayegh, WA; Aljumaiah, O; Andrews, GE; Phylaktou, HN

    2017-01-01

    Electrical cables with PVC sheaths were investigated for their ignition characteristics, heat release and toxic yields using the cone calorimeter. 40 KW/m² was required to get a significant heat release for PVC. A heated Temet Gasmet FTIR was used for the toxic gas analysis. Gas samples were taken from the cone calorimeter diluted exhaust duct and transferred to the FTIR using a 190°C heated sample line, heated pump and filter and a second 190°C heated sample line between the pump and the FTI...

  5. Light-cone quantized QCD and novel hadron phenomenology

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, S.J.

    1997-09-01

    The authors reviews progress made in solving gauge theories such as collinear quantum chromodynamics using light-cone Hamiltonian methods. He also shows how the light-cone Fock expansion for hadron wavefunctions can be used to compute operator matrix elements such as decay amplitudes, form factors, distribution amplitudes, and structure functions, and how it provides a tool for exploring novel features of QCD. The author also reviews commensurate scale relations, leading-twist identities which relate physical observables to each other, thus eliminating renormalization scale and scheme ambiguities in perturbative QCD predictions.

  6. [Cone-beam pseudo lambda tomography under FDK framework].

    Science.gov (United States)

    Huang, Jing; Ma, Jian-hua; Chen, Ling-jian; Bi, Yi-ming; Chen, Wu-fan

    2009-10-01

    The medical CT scanner is rapidly evolving from the fan-beam mode to the cone-beam geometry mode. In this paper, a new cone-beam pseudo Lambda tomography was proposed based on the Noo's fan beam super-short scan formula and FDK framework. The proposed pseudo-LT algorithm, which avoids the computation of any PI line and any differential operation, has a significant practical implementation, thus leading to the images with quality improvement and reduced artifacts. The results in the simulation studies confirm the observation that the new algorithm can improve the image resolution over the traditional algorithms with noise projection data.

  7. Flat panel detector-based cone beam computed tomography with a circle-plus-two-arcs data acquisition orbit: Preliminary phantom study

    International Nuclear Information System (INIS)

    Ning Ruola; Tang Xiangyang; Conover, David; Yu Rongfeng

    2003-01-01

    different phantoms mainly in the central plane of the cone beam reconstruction. Finally, the reconstruction accuracy of using the circle-plus-two-arcs orbit and its related filtered backprojection cone beam volume CT reconstruction algorithm was evaluated with a specially designed disk phantom. The results obtained using the new cone beam acquisition orbit and the related reconstruction algorithm were compared to those obtained using a single-circle cone beam geometry and Feldkamp's algorithm in terms of reconstruction accuracy. The results of the study demonstrate that the circle-plus-two-arcs cone beam orbit is achievable in practice. Also, the reconstruction accuracy of cone beam reconstruction is significantly improved with the circle-plus-two-arcs orbit and its related exact CB-FPB algorithm, as compared to using a single circle cone beam orbit and Feldkamp's algorithm

  8. Targeted sequencing of venom genes from cone snail genomes improves understanding of conotoxin molecular evolution.

    Science.gov (United States)

    Phuong, Mark A; Mahardika, Gusti N

    2018-03-05

    To expand our capacity to discover venom sequences from the genomes of venomous organisms, we applied targeted sequencing techniques to selectively recover venom gene superfamilies and non-toxin loci from the genomes of 32 cone snail species (family, Conidae), a diverse group of marine gastropods that capture their prey using a cocktail of neurotoxic peptides (conotoxins). We were able to successfully recover conotoxin gene superfamilies across all species with high confidence (> 100X coverage) and used these data to provide new insights into conotoxin evolution. First, we found that conotoxin gene superfamilies are composed of 1-6 exons and are typically short in length (mean = ∼85bp). Second, we expanded our understanding of the following genetic features of conotoxin evolution: (a) positive selection, where exons coding the mature toxin region were often three times more divergent than their adjacent noncoding regions, (b) expression regulation, with comparisons to transcriptome data showing that cone snails only express a fraction of the genes available in their genome (24%-63%), and (c) extensive gene turnover, where Conidae species varied from 120-859 conotoxin gene copies. Finally, using comparative phylogenetic methods, we found that while diet specificity did not predict patterns of conotoxin evolution, dietary breadth was positively correlated with total conotoxin gene diversity. Overall, the targeted sequencing technique demonstrated here has the potential to radically increase the pace at which venom gene families are sequenced and studied, reshaping our ability to understand the impact of genetic changes on ecologically relevant phenotypes and subsequent diversification.

  9. A remote control neutron cone scanner and measurement of the d(T,n) α neutron cone

    International Nuclear Information System (INIS)

    Suwanakachorn, D.; Vilaithong, T.; Vilaithong, C.; Boonyawan, D.; Chimooy, T.; Sornphorm, P.; Hoyce, G.; Pairsuwan, W.; Singkarat, S.

    1988-01-01

    We have measured the neutron cone associated with alpha particles from the d(T,n)α reaction by using a remote-control cone scanner. This scanner has two principal parts. The first part is the neutron detector scanner which can move the detector in the horizontal and vertical axis using to stepping-motors. The neutron detector can be moved in 0.5 cm increments over the whole rage of 30 cm. The second part is the remote-control electronic circuit using digital ICs. The rotation of stepping-motors is controlled by pulse signals from this circuit and the position of the detector is known by counting the number of pulses. The position of the neutron detector is indicated directly on a 3 digit display at the control panel. The method of measuring the neutron cone by the Time-of-Flight technique is also described

  10. Intraretinal variability and specialization of cones in Japanese anchovy (Engraulis japonicus, Engraulidae).

    Science.gov (United States)

    Kondrashev, S L; Kornienko, M S; Gnyubkina, V P; Frolova, L T

    2016-04-01

    The retina of anchovies is characterized by an unusual arrangement and ultrastructure of cones. In the retina of Japanese anchovies, Engraulis japonicus, three types of cones are distributed into rows. The nasal, central, temporal, and ventro-temporal regions of the retina were occupied exclusively by the long and short cones. Triple cones, made up of two lateral components and one smaller central component, were found only in the dorsal and ventro-nasal retinal regions. In the outer segments of all short and long cones from the ventro-temporal region, the lamellae were oriented along the cell axis and were perpendicular to the lamellae in the long cones, providing a morphological basis for the detection of polarization. This lamellar orientation is unique to all vertebrates. The cones were examined with respect to regional differentiation in their size and spectral properties via light microscopy, transmission electron microscopy, and microspectrophotometry. Various dimensions of cones were measured in preparations of isolated cells. The cones from the ventro-temporal region had different dimensions than cones of the same type located in other retinal regions. Triple cones from the dorsal region were significantly larger than triple cones from the ventro-nasal region. The spectral absorbance of the lateral components of triple cones in the ventro-nasal retina was identical to the absorbance of all long and short cones from the ventro-temporal region. These are shifted to shorter wavelengths relative to the absorbance of the lateral components of the triple cones located in the dorsal retina. Thus, the retina of the Japanese anchovy shows some features of regional specialization common in other fishes that improves spatial resolution for the upwards and forwards visual axis and provides spectral tuning in downwelling light environment. That results from the differentiation of cone types by size and by different spectral sensitivity of various retinal areas. © 2016

  11. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Jarillo-Herrero, Pablo [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2017-02-07

    This is the final report of our research program on electronic transport experiments on Topological Insulator (TI) devices, funded by the DOE Office of Basic Energy Sciences. TI-based electronic devices are attractive as platforms for spintronic applications, and for detection of emergent properties such as Majorana excitations , electron-hole condensates , and the topological magneto-electric effect . Most theoretical proposals envision geometries consisting of a planar TI device integrated with materials of distinctly different physical phases (such as ferromagnets and superconductors). Experimental realization of physics tied to the surface states is a challenge due to the ubiquitous presence of bulk carriers in most TI compounds as well as degradation during device fabrication.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  13. Fast pyrolysis of biomass in the rotating cone reactor. Reactor development and operation. Final report

    International Nuclear Information System (INIS)

    Gansekoele, E.; Wagenaar, B.M.

    2001-07-01

    This report describes the design and characteristics of BTGs pyrolysis plant with a biomass throughput capacity of 50 kg per hour. The pilot plant has been developed for 2 reasons: to produce modest quantities of bio-oil for application purposes, and to generate know-how for the development of a larger 200 kg/hr pilot plant. The design of the 50 kg/hr plant continues the development line which started in 1995 when a similar unit was delivered to China. Major design improvements of the current pyrolysis unit are that it can be operated in a continuous mode and utilizes the combustion heat of the produced char to heat the pyrolysis process. A measurement program has meanwhile been executed as a means to characterize the pyrolysis plant. Results of the characterization study were the following: the pilot plant produces approx. 35 liters of bio-oil per hour and thus achieves a maximum oil yield of 70 weight percent. The bio-oil yield of the plant was inversely proportional with the reactor temperature and inversely proportional with the gas phase residence time. As a result of the pilot plant operation, a few tons of bio-oil have been produced; alongside with a bulk of know-how. All know-how has successfully been utilized in the development of the 200 kg per hour facility

  14. Volatile emissions from Cascade cinder cone eruptions: Implications for future hazard assessments in the Central and Southern Cascades

    Science.gov (United States)

    Walsh, L. K.; Wallace, P. J.; Cashman, K. V.

    2012-12-01

    An abundance of hazardous effects including ash fall out, basaltic lava flows and poisonous volcanic gas have been documented at active volcanic centers (e.g. Auckland Volcanic Field, New Zealand; Bebbington and Cronin 2011) and have been inferred using tools such as geologic mapping and geochemical analyses for prehistoric eruptions (e.g. Cerro Negro, Nicaragua; Hill et al. 1995; McKnight and Williams 1997). The Cascades volcanic history is also dominated by prehistoric eruptions; however the associated hazards have yet to be studied in-depth. Short recurrence rates of cinder cone volcanism (1x10-5 to 5x10-4 events/yr; Smid et al. 2009) likely intensify the probability of human experience with cinder cone hazards. Hence, it is important to understand the effects that cinder cone volcanism can have on communities near the Cascades. In this study, we estimate volatile fluxes of prehistoric Cascade cinder cone eruptions by analyzing olivine-hosted melt inclusions and rapidly quenched tephra matrix glass. The melt inclusions provide pre-eruptive volatile concentrations whereas tephra groundmass glass provides post-eruptive volatile concentrations. By comparing initial and final concentrations we can determine the amounts of sulfur, chlorine and fluorine released into the atmosphere. We have analyzed S, Cl and F concentrations in melt inclusions from cinder cones in the Central Oregon Cascades (Collier Cone, Yapoah Crater, Four-in-One Fissure, Garrison Butte) and in Northern California near Mt. Lassen (Cinder Cone, Basalt of Old Railroad Grade, Basalt of Highway 44). Analyses of volatiles in melt inclusions and matrix glasses were done using the Cameca SX100 electron microprobe at the University of Oregon. Melt inclusions and matrix glass were run under 15kV, 50nA, and 10μm-beam conditions. For F analyses, a use of an LTAP crystal and relatively long counting times (160 sec. on peak) resulted in good analytical precision. Preliminary results for melt inclusions from

  15. Effective lifetime of minority carriers in black silicon nano-textured by cones and pyramids

    DEFF Research Database (Denmark)

    Onyshchenko, V.F.; Karachevtseva, L.A.; Lytvynenko, O.O.

    2017-01-01

    We calculated the dependence of effective lifetime of minority carriers in black silicon nano-textured by cones and pyramids on the diameter of the cone base, the side of the pyramid base, the height of cone and pyramid. The numerical calculation shows that n-type polished plate of single crystal...

  16. Some Extensions of Banach's Contraction Principle in Complete Cone Metric Spaces

    Directory of Open Access Journals (Sweden)

    Raja P

    2008-01-01

    Full Text Available Abstract In this paper we consider complete cone metric spaces. We generalize some definitions such as -nonexpansive and -uniformly locally contractive functions -closure, -isometric in cone metric spaces, and certain fixed point theorems will be proved in those spaces. Among other results, we prove some interesting applications for the fixed point theorems in cone metric spaces.

  17. An Alternating Direction Method for Convex Quadratic Second-Order Cone Programming with Bounded Constraints

    Directory of Open Access Journals (Sweden)

    Xuewen Mu

    2015-01-01

    quadratic programming over second-order cones and a bounded set. At each iteration, we only need to compute the metric projection onto the second-order cones and the projection onto the bound set. The result of convergence is given. Numerical results demonstrate that our method is efficient for the convex quadratic second-order cone programming problems with bounded constraints.

  18. Screening and Validation of Highly-Efficient Insecticidal Conotoxins from a Transcriptome-Based Dataset of Chinese Tubular Cone Snail

    Directory of Open Access Journals (Sweden)

    Bingmiao Gao

    2017-07-01

    Full Text Available Most previous studies have focused on analgesic and anti-cancer activities for the conotoxins identified from piscivorous and molluscivorous cone snails, but little attention has been devoted to insecticidal activity of conotoxins from the dominant vermivorous species. As a representative vermivorous cone snail, the Chinese tubular cone snail (Conus betulinus is the dominant Conus species inhabiting the South China Sea. We sequenced related venom transcriptomes from C. betulinus using both the next-generation sequencing and traditional Sanger sequencing technologies, and a comprehensive library of 215 conotoxin transcripts was constructed. In our current study, six conotoxins with potential insecticidal activity were screened out from our conotoxin library by homologous search with a reported positive control (alpha-conotoxin ImI from C. imperialis as the query. Subsequently, these conotoxins were synthesized by chemical solid-phase and oxidative folding for further insecticidal activity validation, such as MTT assay, insect bioassay and homology modeling. The final results proved insecticidal activities of our achieved six conotoxins from the transcriptome-based dataset. Interestingly, two of them presented a lot of high insecticidal activity, which supports their usefulness for a trial as insecticides in field investigations. In summary, our present work provides a good example for high throughput development of biological insecticides on basis of the accumulated genomic resources.

  19. New observations on shatter cones in the Vredefort impact structure, South Africa, and evaluation of current hypotheses for shatter cone formation

    Science.gov (United States)

    Wieland, F.; Reimold, W. U.; Gibson, R. L.

    2006-11-01

    Shatter cones have been described from many meteorite impact structures and are widely regarded as a diagnostic macroscopic recognition feature for impact. However, the origin of this meso- to macroscopic striated fracture phenomenon has not yet been satisfactorily resolved, and the timing of shatter cone formation in the cratering process still remains enigmatic. Here, previous results from studies of shatter cones from the Vredefort impact structure and other impact structures are discussed in the light of new field observations made in the Vredefort Dome. Contrary to earlier claims, Vredefort cone fractures do not show uniform apex orientations at any given outcrop, nor do small cones show a pattern consistent with the previously postulated "master cone" concept. Simple back-rotation of impact-rotated strata to a horizontal pre-impact position also does not lead to a uniform centripetal-upward orientation of the cone apices. Striation patterns on the cone surfaces are variable, ranging from the typically diverging pattern branching off the cone apex to subparallel-to-parallel patterns on almost flat surfaces. Striation angles on shatter cones do not increase with distance from the center of the dome, as alleged in the literature. Instead, a range of striation angles is measured on individual shatter cones from a specific outcrop. New observations on small-scale structures in the collar around the Vredefort Dome confirm the relationship of shatter cones with subparallel sets of curviplanar fractures (so-called multipli-striated joint sets, MSJS). Pervasive, meter-scale tensile fractures cross-cut shatter cones and appear to have formed after the closely spaced MSJ-type fractures. The results of this study indicate that none of the existing hypotheses for the formation of shatter cones are currently able to adequately explain all characteristics of this fracturing phenomenon. Therefore, we favor a combination of aspects of different hypotheses that includes the

  20. Effect of temperature on cone bursting, seed extraction and ...

    African Journals Online (AJOL)

    Pinus roxburghii (chir pine or long-needle pine) is considered to be a fire-hardy species. In this study the effect of a wide range of elevated temperatures (from 40 °C to 150 °C) on cone bursting and subsequent seed germination was examined in five provenances of P. roxburghii in comparison to sun drying. The maximum ...

  1. Compensation of Gaussian curvature in developable cones is local

    Science.gov (United States)

    Wang, Jin W.; Witten, Thomas A.

    2009-10-01

    We use the angular deficit scheme [V. Borrelli, F. Cazals, and J.-M. Morvan, Comput. Aided Geom. Des. 20, 319 (2003)] to determine the distribution of Gaussian curvature in developable cones (d-cones) [E. Cerda, S. Chaieb, F. Melo, and L. Mahadevan, Nature (London) 401, 46 (1999)] numerically. These d-cones are formed by pushing a thin elastic sheet into a circular container. Negative Gaussian curvatures are identified at the rim where the sheet touches the container. Around the rim there are two narrow bands with positive Gaussian curvatures. The integral of the (negative) Gaussian curvature near the rim is almost completely compensated by that of the two adjacent bands. This suggests that the Gauss-Bonnet theorem which constrains the integral of Gaussian curvature globally does not explain the spontaneous curvature cancellation phenomenon [T. Liang and T. A. Witten, Phys. Rev. E 73, 046604 (2006)]. The locality of the compensation seems to increase for decreasing d-cone thickness. The angular deficit scheme also provides a way to confirm the curvature cancellation phenomenon.

  2. Cone calorimeter testing of vegetation--an update

    Science.gov (United States)

    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...

  3. Further delineation of spondylometaphyseal dysplasia with cone-rod dystrophy

    NARCIS (Netherlands)

    Sousa, Sérgio B.; Russell-Eggitt, Isabelle; Hall, Christine; Hall, Bryan D.; Hennekam, Raoul C. M.

    2008-01-01

    There are several entities that combine a skeletal dysplasia with a retinal dystrophy. Recently, another possibly autosomal recessive entity was added to this group characterized by a specific spondylometaphyseal dysplasia and a cone-rod dystrophy, without other significant impairments. The entity

  4. Game Characterizations and Lower Cones in the Weihrauch Degrees

    NARCIS (Netherlands)

    Nobrega, H.; Pauly, A.; Kari, J.; Manea, F.; Petre, I.

    2017-01-01

    We introduce generalized Wadge games and show that each lower cone in the Weihrauch degrees is characterized by such a game. These generalized Wadge games subsume (a variant of) the original Wadge game, the eraser and backtrack games as well as Semmes’s tree games. In particular, we propose that the

  5. Bi-cone vacuum chamber in the ISR

    CERN Multimedia

    CERN PhotoLab

    1976-01-01

    The "bi-cone" vacuum chamber in ISR intersection I-7, for experiment R702. Made from 0.28 mm thick titanium, it was at its time the most transparent chamber ever built. Ian Wilson is standing next to the chamber. See also 7609219.

  6. Expanded clinical spectrum of enhanced S-cone syndrome

    NARCIS (Netherlands)

    Yzer, Suzanne; Barbazetto, Irene; Allikmets, Rando; van Schooneveld, Mary J.; Bergen, Arthur; Tsang, Stephen H.; Jacobson, Samuel G.; Yannuzzi, Lawrence A.

    2013-01-01

    New funduscopic findings in patients with enhanced S-cone syndrome (ESCS) may help clinicians in diagnosing this rare autosomal recessive retinal dystrophy. To expand the clinical spectrum of ESCS due to mutations in the NR2E3 gene. Retrospective, noncomparative case series of 31 patients examined

  7. Spatial correlation length of normalized cone data in sand

    DEFF Research Database (Denmark)

    Firouzianbandpey, Sarah; Griffiths, D. V.; Ibsen, Lars Bo

    2014-01-01

    it is rarely estimated during routine site investigations. Results from two different sites in the north of Denmark are reported in this paper, indicating quite strong anisotropy due to the depositional process, with significantly shorter spatial correlation lengths in the vertical direction. It is observed...... that the normalized cone resistance is a better estimator of spatial trends than the normalized friction ratio....

  8. Cracking cone fracture after cold compaction of argillaceous particles

    Indian Academy of Sciences (India)

    In this work an experimental investigation has been focused on the `cracking cone' fracture in powder compacts. This includes studies of crack propagation and determination of operating conditions to avoid the green body fracture. The numerical modelling is implemented using a finite element method based on the Von ...

  9. Quantization on the cone and cyon-oscillator duality

    International Nuclear Information System (INIS)

    Sisakyan, A.N.; Ter-Antonyan, V.M.

    1996-01-01

    It is shown that the three-dimensional isotropic oscillator with coordinates belonging to the two-dimensional half-up cone is dual to the cyon, i.e. the planar particle-vortex bound system provided by fractional statistics. 12 refs

  10. Virginia pine seed viable two months before natural cone opening

    Science.gov (United States)

    Thomas W., Jr. Church; Edward I. Sucoff

    1960-01-01

    Virginia pine (Pinus virginiana Mill.) seed used in nurseries and for forest seeding ordinarily is collected from standing or felled trees in autumn. Some questions that concern the seed collector are: How early in the season does Virginia pine seed ripen? How does seed viability change if the cones are left on the felled trees?

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

    Science.gov (United States)

    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...

  12. Optical conductivity of disordered graphene beyond the Dirac cone approximation

    NARCIS (Netherlands)

    Yuan, Shengjun; Roldan, Rafael; De Raedt, Hans; Katsnelson, Mikhail I.

    2011-01-01

    In this paper we systemically study the optical conductivity and density of states of disordered graphene beyond the Dirac cone approximation. The optical conductivity of graphene is computed by using the Kubo formula, within the framework of a full p-band tight-binding model. Different types of

  13. Production well water coning : Is there anything we can do?

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, F.B.; Shtepani, E.; Marosi, G.; Bennion, D.B. [Hycal Energy Research Laboratories Ltd., Calgary, AB (Canada)

    2002-06-01

    It is not unusual for a reservoir to have an aquifer beneath the zone of hydrocarbon, which might end up acting as a constant-pressure lower boundary. Water coning can be described as the water drive dominating and filling the near wellbore region with water, leading to production slow downs and in certain cases, a substantial revenue loss. This phenomenon affects both oil and gas wells throughout the world. A potential solution for serious water-coning reservoirs was proposed in this paper. Chemical treatment options were included in a coning simulation model in an attempt to find the optimal treatment volume and was discussed as well. An estimation of the size of a water shut-off treatment might be accomplished through an analysis of the axial and radial velocity gradient. The authors indicated that early application of water shut-off was better after the full development of the cone. The paper reviewed the chemical solutions, as well as a sampling of the laboratory tests that can be performed in the analysis of potential treatments. 15 refs., 21 figs.

  14. Harmonic Function of Poincare Cone Condition In Solving Dirichlet ...

    African Journals Online (AJOL)

    Harmonic Function of Poincare Cone Condition In Solving Dirichlet Problem. ... Journal of the Nigerian Association of Mathematical Physics ... theorem, the dirichlet problem and maximum principle where we conclude that the application of sums , differences and scalar multiples of harmonic functions are again harmonic.

  15. Cones and craters on Mount Pavagadh, Deccan Traps: Rootless ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    The mountain is surrounded by smaller hills, some of which apparently represent individ- ual satellite vents. Rhyolite outcrops, and volcanic breccia deposits with clear quaquaversal dips, are seen in these hills. Here we describe the shal- low cones with craters that are found on the uppermost mafic lava flow of Mount ...

  16. Dirac cones beyond the honeycomb lattice : a symmetry based approach

    NARCIS (Netherlands)

    Miert, G. van; de Morais Smith, Cristiane

    2016-01-01

    Recently, several new materials exhibiting massless Dirac fermions have been proposed. However, many of these do not have the typical graphene honeycomb lattice, which is often associated with Dirac cones. Here, we present a classification of these different two-dimensional Dirac systems based on

  17. Salamander blue-sensitive cones lost during metamorphosis.

    NARCIS (Netherlands)

    Chen, Y.; Znoiko, S.; Grip, W.J. de; Crouch, R.K.; Ma, J.X.

    2008-01-01

    The tiger salamander lives in shallow water with bright light in the aquatic phase, and in dim tunnels or caves in the terrestrial phase. In the aquatic phase, there are five types of photoreceptors--two types of rods and three types of cones. Our previous studies showed that the green rods and

  18. Cone Penetration Testing: A Sound Method for Urban Archaeological Prospection

    NARCIS (Netherlands)

    Koster, K.

    2015-01-01

    Cone Penetration Testing (CPT) is a geotechnical in situ site investigation method and is widely applied in urbanized areas of the Netherlands. Approximately 20,000 CPTs are conducted in the Netherlands each year. The frequency of such testing, and the presence of archaeological deposits within the

  19. Guidelines for cone penetration test : performance and design

    Science.gov (United States)

    1978-07-01

    This manual presents procedures and guidelines applicable to the use of the cone penetration test. Dr. Schmertmann prepared this manual in February 1977 and made minor additions in May 1978. It represents his interpretation of the state-of-the-art in...

  20. Genetic Etiology and Clinical Consequences of Cone Disorders

    NARCIS (Netherlands)

    A.A.H.J. Thiadens (Alberta)

    2011-01-01

    textabstractHereditary retinal disorders constitute a large heterogeneous group of diseases in which the photoreceptors are primarily aff ected. When cone cells are aff ected, one cannot see details or perceive color. In this thesis, we focused on the three most important diseases in which the

  1. Double half-cone flap umbilicoplasty for proboscoid umbilical hernia ...

    African Journals Online (AJOL)

    Surgical repair of large umbilical hernias may present a challenging surgical problem; standard surgical techniques have proven to be inadequate for both closing the fascial defect of the umbilicus and providing a satisfactory cosmetic result. We describe here a case of double half-cone flap umbilicoplasty that was ...

  2. Are You Looking at Me? Measuring the Cone of Gaze

    Science.gov (United States)

    Gamer, Matthias; Hecht, Heiko

    2007-01-01

    The processing of gaze cues plays an important role in social interactions, and mutual gaze in particular is relevant for natural as well as video-mediated communications. Mutual gaze occurs when an observer looks at or in the direction of the eyes of another person. The authors chose the metaphor of a cone of gaze to characterize this range of…

  3. A statistical approach to motion compensated cone-beam

    DEFF Research Database (Denmark)

    Lyksborg, Mark; Hansen, Mads Fogtmann; Larsen, Rasmus

    One of the problems arising in radiotherapy planning is the quality of CT planning data. In the following attention is giving to the cone-beam scanning geometry where reconstruction of a 3D volume based on 2D projections, using the classic Feldkamp-Davis-Kress (FDK) algorithm requires a large num...

  4. Increasing Cone-beam projection usage by temporal fitting

    DEFF Research Database (Denmark)

    Lyksborg, Mark; Hansen, Mads Fogtmann; Larsen, Rasmus

    2010-01-01

    A Cone-beam CT system can be used to image the lung region. The system records 2D projections which will allow 3D reconstruction however a reconstruction based on all projections will lead to a blurred reconstruction in regions were respiratory motion occur. To avoid this the projections are typi...

  5. A Statistical Approach to Motion Compensated Cone Beam Reconstruction

    DEFF Research Database (Denmark)

    Lyksborg, Mark; Hansen, Mads Fogtmann; Larsen, Rasmus

    2010-01-01

    One of the problems arising in radiotherapy planning is the quality of CT planning data. In the following attention is giving to the cone-beam scanning geometry where reconstruction of a 3D volume based on 2D projections, using the classic Feldkamp-Davis-Kress (FDK) algorithm requires a large...

  6. Geometric studies on variable radius spiral cone-beam scanning

    International Nuclear Information System (INIS)

    Ye Yangbo; Zhu Jiehua; Wang Ge

    2004-01-01

    The goal is to perform geometric studies on cone-beam CT scanning along a three-dimensional (3D) spiral of variable radius. First, the background for variable radius spiral cone-beam scanning is given in the context of electron-beam CT/micro-CT. Then, necessary and sufficient conditions are proved for existence and uniqueness of PI lines inside the variable radius 3D spiral. These results are necessary steps toward exact cone-beam reconstruction from a 3D spiral scan of variable radius, adapting Katsevich's formula for the standard helical cone-beam scanning. It is shown in the paper that when the longitudinally projected planar spiral is not always convex toward the origin, the PI line may not be unique in the envelope defined by the tangents of the spiral. This situation can be avoided by using planar spirals whose curvatures are always positive. Using such a spiral, a longitudinally homogeneous region inside the corresponding 3D spiral is constructed in which any point is passed by one and only one PI line, provided the angle ω between planar spiral's tangent and radius is bounded by vertical bar ω-90 deg. vertical bar ≤ε for some positive ε≤32.48 deg. If the radius varies monotonically, this region is larger and one may allow ε≤51.85 deg. Examples for 3D spirals based on logarithmic and Archimedean spirals are given. The corresponding generalized Tam-Danielsson detection windows are also formulated

  7. Cone beam computed tomography in Endodontics - a review

    NARCIS (Netherlands)

    Patel, S.; Durack, C.; Abella, F.; Shemesh, H.; Roig, M.; Lemberg, K.

    2015-01-01

    Cone beam computed tomography (CBCT) produces undistorted three-dimensional information of the maxillofacial skeleton, including the teeth and their surrounding tissues with a lower effective radiation dose than computed tomography. The aim of this paper is to: (i) review the current literature on

  8. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Webb, Robert C. [Texas A& M University; Kamon, Teruki [Texas A& M University; Toback, David [Texas A& M University; Safonov, Alexei [Texas A& M University; Dutta, Bhaskar [Texas A& M University; Dimitri, Nanopoulos [Texas A& M University; Pope, Christopher [Texas A& M University; White, James [Texas A& M University

    2013-11-18

    Overview The High Energy Physics Group at Texas A&M University is submitting this final report for our grant number DE-FG02-95ER40917. This grant has supported our wide range of research activities for over a decade. The reports contained here summarize the latest work done by our research team. Task A (Collider Physics Program): CMS & CDF Profs. T. Kamon, A. Safonov, and D. Toback co-lead the Texas A&M (TAMU) collider program focusing on CDF and CMS experiments. Task D: Particle Physics Theory Our particle physics theory task is the combined effort of Profs. B. Dutta, D. Nanopoulos, and C. Pope. Task E (Underground Physics): LUX & NEXT Profs. R. Webb and J. White(deceased) lead the Xenon-based underground research program consisting of two main thrusts: the first, participation in the LUX two-phase xenon dark matter search experiment and the second, detector R&D primarily aimed at developing future detectors for underground physics (e.g. NEXT and LZ).

  9. Development and Verification of Novel Porous Titanium Metaphyseal Cones for Revision Total Knee Arthroplasty.

    Science.gov (United States)

    Faizan, Ahmad; Bhowmik-Stoker, Manoshi; Alipit, Vincent; Kirk, Amanda E; Krebs, Viktor E; Harwin, Steven F; Meneghini, R Michael

    2017-06-01

    Porous metaphyseal cones are widely used in revision knee arthroplasty. A new system of porous titanium metaphyseal cones has been designed based on the femoral and tibial morphology derived from a computed tomography-based anatomical database. The purpose of this study is to evaluate the initial mechanical stability of the new porous titanium revision cone system by measuring the micromotion under physiologic loading compared with a widely-used existing porous tantalum metaphyseal cone system. The new cones were designed to precisely fit the femoral and tibial anatomy, and 3D printing technology was used to manufacture these porous titanium cones. The stability of the new titanium cones and the widely-used tantalum cones were compared under physiologic loading conditions in bench top test model. The stability of the new titanium cones was either equivalent or better than the tantalum cones. The new titanium femoral cone construct had significantly less micromotion compared with the traditional femoral cone construct in 5 of the 12 directions measured (P titanium metaphyseal tibial cones demonstrated less micromotion in medial varus/valgus (P = .004) and posterior compressive micromotion (P = .002) compared with the traditional porous tantalum system. The findings of this biomechanical study demonstrate satisfactory mechanical stability of an anatomical-based porous titanium metaphyseal cone system for femoral and tibial bone loss as measured by micromotion under physiologic loading. The new cone design, in combination with instrumentation that facilitates surgical efficiency, is encouraging. Long-term clinical follow-up is warranted. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Cone selection by Eurasian red squirrels in mixed conifer forests in the Italian Alps

    Science.gov (United States)

    Molinari, A.; Wauters, L. A.; Airoldi, G.; Cerinotti, F.; Martinoli, A.; Tosi, G.

    2006-07-01

    Tree squirrels are arboreal granivores that harvest and consume tree seeds both prior to and after seed-dispersal. Inter- and intraspecific patterns of seed predation suggest that squirrels may exert strong selective pressure on cone morphology and patterns of cone production, and suggest coevolutionary interactions between squirrels and conifers. In some pine species (genus Pinus), mutualistic relationships have evolved between cone (seed) traits and seed-dispersal behaviour by birds and rodents. In other species, feeding by seed predators has selected for cone traits that decrease intensity of seed consumption. In mixed conifer forests, red squirrels ( Sciurus vulgaris) feed intensively in some (target) trees but avoid others (nontarget trees). Here we explore defensive cone traits and seed traits correlated with tree selection for conifer species with different seed-dispersal strategies. No selection for cone traits existed in Pinus cembra, which has large wingless seeds, dispersed by birds and rodents. In Picea abies, the most favoured species, target trees had cones with more seeds per cone than nontarget trees, and number of seeds increased with cone length. Cone selection was most pronounced in Pinus sylvestris, where target trees had bigger cones with more seeds and higher total seed mass than nontarget trees. However, ratio of seed mass on cone mass did not differ among target and nontarget trees, suggesting that bigger cones also had more protective tissue, probably increasing difficulties for seed predators to gain access to seeds. Our results suggest that cone and seed traits of P. cembra facilitate seed consumption by squirrels, but that defensive cone traits of small-seeded conifers, in combination with annual differences in seed production (masting), might be the result of coevolution with seed-eating squirrels.

  11. Relationship between foveal cone specialization and pit morphology in albinism.

    Science.gov (United States)

    Wilk, Melissa A; McAllister, John T; Cooper, Robert F; Dubis, Adam M; Patitucci, Teresa N; Summerfelt, Phyllis; Anderson, Jennifer L; Stepien, Kimberly E; Costakos, Deborah M; Connor, Thomas B; Wirostko, William J; Chiang, Pei-Wen; Dubra, Alfredo; Curcio, Christine A; Brilliant, Murray H; Summers, C Gail; Carroll, Joseph

    2014-05-20

    Albinism is associated with disrupted foveal development, though intersubject variability is becoming appreciated. We sought to quantify this variability, and examine the relationship between foveal cone specialization and pit morphology in patients with a clinical diagnosis of albinism. We recruited 32 subjects with a clinical diagnosis of albinism. DNA was obtained from 25 subjects, and known albinism genes were analyzed for mutations. Relative inner and outer segment (IS and OS) lengthening (fovea-to-perifovea ratio) was determined from manually segmented spectral domain-optical coherence tomography (SD-OCT) B-scans. Foveal pit morphology was quantified for eight subjects from macular SD-OCT volumes. Ten subjects underwent imaging with adaptive optics scanning light ophthalmoscopy (AOSLO), and cone density was measured. We found mutations in 22 of 25 subjects, including five novel mutations. All subjects lacked complete excavation of inner retinal layers at the fovea, though four subjects had foveal pits with normal diameter and/or volume. Peak cone density and OS lengthening were variable and overlapped with that observed in normal controls. A fifth hyper-reflective band was observed in the outer retina on SD-OCT in the majority of the subjects with albinism. Foveal cone specialization and pit morphology vary greatly in albinism. Normal cone packing was observed in the absence of a foveal pit, suggesting a pit is not required for packing to occur. The degree to which retinal anatomy correlates with genotype or visual function remains unclear, and future examination of larger patient groups will provide important insight on this issue. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

  12. Relationship Between Foveal Cone Specialization and Pit Morphology in Albinism

    Science.gov (United States)

    Wilk, Melissa A.; McAllister, John T.; Cooper, Robert F.; Dubis, Adam M.; Patitucci, Teresa N.; Summerfelt, Phyllis; Anderson, Jennifer L.; Stepien, Kimberly E.; Costakos, Deborah M.; Connor, Thomas B.; Wirostko, William J.; Chiang, Pei-Wen; Dubra, Alfredo; Curcio, Christine A.; Brilliant, Murray H.; Summers, C. Gail; Carroll, Joseph

    2014-01-01

    Purpose. Albinism is associated with disrupted foveal development, though intersubject variability is becoming appreciated. We sought to quantify this variability, and examine the relationship between foveal cone specialization and pit morphology in patients with a clinical diagnosis of albinism. Methods. We recruited 32 subjects with a clinical diagnosis of albinism. DNA was obtained from 25 subjects, and known albinism genes were analyzed for mutations. Relative inner and outer segment (IS and OS) lengthening (fovea-to-perifovea ratio) was determined from manually segmented spectral domain-optical coherence tomography (SD-OCT) B-scans. Foveal pit morphology was quantified for eight subjects from macular SD-OCT volumes. Ten subjects underwent imaging with adaptive optics scanning light ophthalmoscopy (AOSLO), and cone density was measured. Results. We found mutations in 22 of 25 subjects, including five novel mutations. All subjects lacked complete excavation of inner retinal layers at the fovea, though four subjects had foveal pits with normal diameter and/or volume. Peak cone density and OS lengthening were variable and overlapped with that observed in normal controls. A fifth hyper-reflective band was observed in the outer retina on SD-OCT in the majority of the subjects with albinism. Conclusions. Foveal cone specialization and pit morphology vary greatly in albinism. Normal cone packing was observed in the absence of a foveal pit, suggesting a pit is not required for packing to occur. The degree to which retinal anatomy correlates with genotype or visual function remains unclear, and future examination of larger patient groups will provide important insight on this issue. PMID:24845642

  13. Impact of oral melatonin on the electroretinogram cone response

    Directory of Open Access Journals (Sweden)

    Rosolen Serge G

    2009-11-01

    Full Text Available Abstract 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.

  14. Numerical Hermitian Yang-Mills connections and Kähler cone substructure

    Science.gov (United States)

    Anderson, Lara B.; Braun, Volker; Ovrut, Burt A.

    2012-01-01

    We further develop the numerical algorithm for computing the gauge connection of slope-stable holomorphic vector bundles on Calabi-Yau manifolds. In particular, recent work on the generalized Donaldson algorithm is extended to bundles with Kähler cone substructure on manifolds with h 1;1 > 1. Since the computation depends only on a one-dimensional ray in the Kähler moduli space, it can probe slope-stability regardless of the size of h 1;1. Suitably normalized error measures are introduced to quantitatively compare results for different directions in Kähler moduli space. A significantly improved numerical integration procedure based on adaptive refinements is described and implemented. Finally, a rapid computational check is proposed for probing the slope-stable stability properties of a given vector bundle.

  15. Metal Artifact Suppression in Dental Cone Beam Computed Tomography Images Using Image Processing Techniques.

    Science.gov (United States)

    Johari, Masoumeh; Abdollahzadeh, Milad; Esmaeili, Farzad; Sakhamanesh, Vahideh

    2018-01-01

    Dental cone beam computed tomography (CBCT) images suffer from severe metal artifacts. These artifacts degrade the quality of acquired image and in some cases make it unsuitable to use. Streaking artifacts and cavities around teeth are the main reason of degradation. In this article, we have proposed a new artifact reduction algorithm which has three parallel components. The first component extracts teeth based on the modeling of image histogram with a Gaussian mixture model. Striking artifact reduction component reduces artifacts using converting image into the polar domain and applying morphological filtering. The third component fills cavities through a simple but effective morphological filtering operation. Finally, results of these three components are combined into a fusion step to create a visually good image which is more compatible to human visual system. Results show that the proposed algorithm reduces artifacts of dental CBCT images and produces clean images.

  16. Short Wavelength Cone Opsin Is Not Expressed in the Retina of Arboreal African Pangolin (Manis tricuspis

    Directory of Open Access Journals (Sweden)

    Adejoke J. Adekanmbi

    2016-01-01

    Full Text Available This paper reports a study of cone photoreceptors present in the retina of Manis tricuspis. Specifically, the LWS (L- opsin expressed in longwave-sensitive cones and SWS1 (S- opsin shortwave-sensitive cones were targeted. Vertical sections revealed reactivity to a cone marker, peanut agglutinin (PNA, and to an LWS antibody, but not to an SWS1 antibody. This suggests that the Manis tricuspis visual system is not able to discriminate shorter wavelengths from longer wavelengths because the short wavelength cones are not expressed in their retina.

  17. Field Test Evaluation of Effect on Cone Resistance Caused by Change in Penetration Rate

    DEFF Research Database (Denmark)

    Poulsen, Rikke; Nielsen, Benjaminn Nordahl; Ibsen, Lars Bo

    2012-01-01

    This paper presents how a change in cone penetration rate affects the measured cone resistance during cone penetration testing in silty soils. Regardless of soil, type the standard rate of penetration is 20 mm/s and it is generally accepted that undrained penetration occurs in clay while drained...... in the laboratory. A change in the measured cone resistance occurs by lowering the penetration rate. This is caused by the changes in drainage conditions. Compared to the normal penetration rate of 20 mm/s, this paper illustrates that lowering the penetration rate leads to an increase in the cone resistance from 1...

  18. Cone photoreceptor structure in patients with x-linked cone dysfunction and red-green color vision deficiency

    DEFF Research Database (Denmark)

    Patterson, Emily J.; Wilk, Melissa; Langlo, Christopher S.

    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...

  19. A Smoothing Method with Appropriate Parameter Control Based on Fischer-Burmeister Function for Second-Order Cone Complementarity Problems

    Directory of Open Access Journals (Sweden)

    Yasushi Narushima

    2013-01-01

    Full Text Available We deal with complementarity problems over second-order cones. The complementarity problem is an important class of problems in the real world and involves many optimization problems. The complementarity problem can be reformulated as a nonsmooth system of equations. Based on the smoothed Fischer-Burmeister function, we construct a smoothing Newton method for solving such a nonsmooth system. The proposed method controls a smoothing parameter appropriately. We show the global and quadratic convergence of the method. Finally, some numerical results are given.

  20. Loss and gain of cone types in vertebrate ciliary photoreceptor evolution.

    Science.gov (United States)

    Musser, Jacob M; Arendt, Detlev

    2017-11-01

    Ciliary photoreceptors are a diverse cell type family that comprises the rods and cones of the retina and other related cell types such as pineal photoreceptors. Ciliary photoreceptor evolution has been dynamic during vertebrate evolution with numerous gains and losses of opsin and phototransduction genes, and changes in their expression. For example, early mammals lost all but two cone opsins, indicating loss of cone receptor types in response to nocturnal lifestyle. Our review focuses on the comparison of specifying transcription factors and cell type-specific transcriptome data in vertebrate retinae to build and test hypotheses on ciliary photoreceptor evolution. Regarding cones, recent data reveal that a combination of factors specific for long-wavelength sensitive opsin (Lws)- cones in non-mammalian vertebrates (Thrb and Rxrg) is found across all differentiating cone photoreceptors in mice. This suggests that mammalian ancestors lost all but one ancestral cone type, the Lws-cone. We test this hypothesis by a correlation analysis of cone transcriptomes in mouse and chick, and find that, indeed, transcriptomes of all mouse cones are most highly correlated to avian Lws-cones. These findings underscore the importance of specifying transcription factors in tracking cell type evolution, and shed new light on the mechanisms of cell type loss and gain in retina evolution. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  1. Development of a full ice-cream cone model for halo CME structures

    Science.gov (United States)

    Na, Hyeonock; Moon, Yong-Jae

    2015-04-01

    The determination of three dimensional parameters (e.g., radial speed, angular width, source location) of Coronal Mass Ejections (CMEs) is very important for space weather forecast. To estimate these parameters, several cone models based on a flat cone or a shallow ice-cream cone with spherical front have been suggested. In this study, we investigate which cone model is proper for halo CME morphology using 33 CMEs which are identified as halo CMEs by one spacecraft (SOHO or STEREO-A or B) and as limb CMEs by the other ones. From geometrical parameters of these CMEs such as their front curvature, we find that near full ice-cream cone CMEs (28 events) are dominant over shallow ice-cream cone CMEs (5 events). So we develop a new full ice-cream cone model by assuming that a full ice-cream cone consists of many flat cones with different heights and angular widths. This model is carried out by the following steps: (1) construct a cone for given height and angular width, (2) project the cone onto the sky plane, (3) select points comprising the outer boundary, (4) minimize the difference between the estimated projection points with the observed ones. We apply this model to several halo CMEs and compare the results with those from other methods such as a Graduated Cylindrical Shell model and a geometrical triangulation method.

  2. Cone Factors from Field Vane and Triaxial Tests in Danish Soils

    DEFF Research Database (Denmark)

    Luke, Kirsten

    1996-01-01

    Six Danish cohesive soils are investigated using Cone Penetration Test (CPT) to estimate the undrained shear strength, cu. Field vane tests and consolidated triaxial tests are used to estimate cu for the six soils. The tested soils all come up with cone factors very close to 10 when using cu from...... the triaxial tests whereas cone factors ranging from 7 to 11 are estimated by using measurements from field vane tests. A strong correlation between the cone factor, Nkt and the friction ratio, fR is obtained when the cone factor is estimated from vane tests. This relation, which is obtained using only the six...... thoroughly investigated soils, is tested on data from other Danish and international sites. Likewise the constant cone factor of Nkt = 10 obtained from the triaxial tests is evaluated and compared with cone factors obtained from triaxial tests in other countries....

  3. Glowing seashells: diversity of fossilized coloration patterns on coral reef-associated cone snail (Gastropoda: Conidae shells from the Neogene of the Dominican Republic.

    Directory of Open Access Journals (Sweden)

    Jonathan R Hendricks

    Full Text Available The biology of modern Conidae (cone snails--which includes the hyperdiverse genus Conus--has been intensively studied, but the fossil record of the clade remains poorly understood, particularly within an evolutionary framework. Here, ultraviolet light is used to reveal and characterize the original shell coloration patterns of 28 species of cone snails from three Neogene coral reef-associated deposits from the Cibao Valley, northern Dominican Republic. These fossils come from the upper Miocene Cercado Fm. and lower Pliocene Gurabo Fm., and range in age from about 6.6-4.8 Ma. Comparison of the revealed coloration patterns with those of extant species allow the taxa to be assigned to three genera of cone snails (Profundiconus, Conasprella, and Conus and at least nine subgenera. Thirteen members of these phylogenetically diverse reef faunas are described as new species. These include: Profundiconus? hennigi, Conasprella (Ximeniconus ageri, Conus anningae, Conus lyelli, Conus (Atlanticonus? franklinae, Conus (Stephanoconus gouldi, Conus (Stephanoconus bellacoensis, Conus (Ductoconus cashi, Conus (Dauciconus garrisoni, Conus (Dauciconus? zambaensis, Conus (Spuriconus? kaesleri, Conus (Spuriconus? lombardii, and Conus (Lautoconus? carlottae. Each of the three reef deposits contain a minimum of 14-16 cone snail species, levels of diversity that are similar to modern Indo-Pacific reef systems. Finally, most of the 28 species can be assigned to modern clades and thus have important implications for understanding the biogeographic and temporal histories of these clades in tropical America.

  4. Calculation and Verification of a Planar Pencil Beam Kernel Through the Hankel Transform of Measured OARs for a Radiosurgery System with Cones

    International Nuclear Information System (INIS)

    Vargas Verdesoto, Milton X.; Alvarez Romero, Jose T.

    2010-01-01

    A planar multienergetic pencil beam kernel with rotational symmetry is calculated for a stereotactic radiosurgery system, SRS, BrainLAB with cones, employing the deconvolution method of the off axis ratio profile, OAR, corresponding to the cone of 35 mm in diameter for a 6 MV photon beam produced by a linear accelerator Varian 2100 C/D. Before the deconvolution, the experimental OAR is corrected for beam divergence and variations of the spectral fluence Φ, using a boundary function BF. The function BF and the fluence Φ are transformed to the conjugate space with the zero order Hankel function, which is the appropriate transform due to the radial symmetry of the circular beams generated by the cones. The kernel in the conjugate space is obtained as the ratio of the transform of BF to the transform of Φ, therefore the kernel in the real space is calculated as the inverse transform of the kernel in the conjugate space. To validate the kernel in the real space, it is convolved with the fluence of the cones of 7.5, 12.5, 15, 17.5, 20, 22.5, 25, 30 and 35 mm in diameter. The comparison of the OARs calculated and measured shows a maximum difference of 4.5% in the zones of high gradient of dose, and a difference less than 2% in the regions of low gradient of dose. Finally, the expanded uncertainty of the kernel is estimated and reported.

  5. Avian cone photoreceptors tile the retina as five independent, self-organizing mosaics.

    Directory of Open Access Journals (Sweden)

    Yoseph A Kram

    2010-02-01

    Full Text Available The avian retina possesses one of the most sophisticated cone photoreceptor systems among vertebrates. Birds have five types of cones including four single cones, which support tetrachromatic color vision and a double cone, which is thought to mediate achromatic motion perception. Despite this richness, very little is known about the spatial organization of avian cones and its adaptive significance. Here we show that the five cone types of the chicken independently tile the retina as highly ordered mosaics with a characteristic spacing between cones of the same type. Measures of topological order indicate that double cones are more highly ordered than single cones, possibly reflecting their posited role in motion detection. Although cones show spacing interactions that are cell type-specific, all cone types use the same density-dependent yardstick to measure intercone distance. We propose a simple developmental model that can account for these observations. We also show that a single parameter, the global regularity index, defines the regularity of all five cone mosaics. Lastly, we demonstrate similar cone distributions in three additional avian species, suggesting that these patterning principles are universal among birds. Since regular photoreceptor spacing is critical for uniform sampling of visual space, the cone mosaics of the avian retina represent an elegant example of the emergence of adaptive global patterning secondary to simple local interactions between individual photoreceptors. Our results indicate that the evolutionary pressures that gave rise to the avian retina's various adaptations for enhanced color discrimination also acted to fine-tune its spatial sampling of color and luminance.

  6. Determination of HCME 3-D parameters using a full ice-cream cone model

    Science.gov (United States)

    Na, Hyeonock; Moon, Yong-Jae; Lee, Harim

    2016-05-01

    It is very essential to determine three dimensional parameters (e.g., radial speed, angular width, source location) of Coronal Mass Ejections (CMEs) for space weather forecast. Several cone models (e.g., an elliptical cone model, an ice-cream cone model, an asymmetric cone model) have been examined to estimate these parameters. In this study, we investigate which cone type is close to a halo CME morphology using 26 CMEs: halo CMEs by one spacecraft (SOHO or STEREO-A or B) and as limb CMEs by the other ones. From cone shape parameters of these CMEs such as their front curvature, we find that near full ice-cream cone type CMEs are much closer to observations than shallow ice-cream cone type CMEs. Thus we develop a new cone model in which a full ice-cream cone consists of many flat cones with different heights and angular widths. This model is carried out by the following steps: (1) construct a cone for given height and angular width, (2) project the cone onto the sky plane, (3) select points comprising the outer boundary, and (4) minimize the difference between the estimated projection speeds with the observed ones. By applying this model to 12 SOHO/LASCO halo CMEs, we find that 3-D parameters from our method are similar to those from other stereoscopic methods (a geometrical triangulation method and a Graduated Cylindrical Shell model) based on multi-spacecraft data. We are developing a general ice-cream cone model whose front shape is a free parameter determined by observations.

  7. Instantons on sine-cones over Sasakian manifolds

    Science.gov (United States)

    Bunk, Severin; Ivanova, Tatiana A.; Lechtenfeld, Olaf; Popov, Alexander D.; Sperling, Marcus

    2014-09-01

    We investigate instantons on sine-cones over Sasaki-Einstein and 3-Sasakian manifolds. It is shown that these conical Einstein manifolds are Kähler with torsion (KT) manifolds admitting Hermitian connections with totally antisymmetric torsion. Furthermore, a deformation of the metric on the sine-cone over 3-Sasakian manifolds allows one to introduce a hyper-Kähler with torsion (HKT) structure. In the large-volume limit these KT and HKT spaces become Calabi-Yau and hyper-Kähler conifolds, respectively. We construct gauge connections on complex vector bundles over conical KT and HKT manifolds which solve the instanton equations for Yang-Mills fields in higher dimensions.

  8. Heat kernel analysis for Bessel operators on symmetric cones

    DEFF Research Database (Denmark)

    Möllers, Jan

    2014-01-01

    . The heat kernel is explicitly given in terms of a multivariable $I$-Bessel function on $Ω$. Its corresponding heat kernel transform defines a continuous linear operator between $L^p$-spaces. The unitary image of the $L^2$-space under the heat kernel transform is characterized as a weighted Bergmann space...... on the complexification $G_{\\mathbb C}/K_{\\mathbb C}$ of $Ω$, the weight being expressed explicitly in terms of a multivariable $K$-Bessel function on $Ω$. Even in the special case of the symmetric cone $Ω=\\mathbb{R}_+$ these results seem to be new.......We investigate the heat equation corresponding to the Bessel operators on a symmetric cone $Ω=G/K$. These operators form a one-parameter family of elliptic self-adjoint second order differential operators and occur in the Lie algebra action of certain unitary highest weight representations...

  9. Specific heat of a particle on the cone

    International Nuclear Information System (INIS)

    Moreira, E. S. Jr.; Oliveira, E. S.

    2006-01-01

    This work investigates how a conical singularity can affect the specific heat of systems. A free nonrelativistic particle confined to the lateral surface of a cone--conical box--is taken as a toy model. Its specific heat is determined as a function of the deficit angle and the temperature. For a vanishing deficit angle, the specific heat is that of a particle in a flat disk where a characteristic temperature separates quantum and classical behaviors, as usual. By increasing the deficit angle the characteristic temperature also increases, and eventually another characteristic temperature (which does not depend on the deficit angle) arises. When the cone gets sufficiently sharp, at low and intermediate temperatures the azimuthal degree of freedom is suppressed. At low temperatures the specific heat varies discontinuously with the deficit angle. Connections between certain theorems regarding common zeros of the Bessel functions and this discontinuity are reported

  10. Cone beam computerized tomography of face. Technological assessment report

    International Nuclear Information System (INIS)

    Saint-Pierre, Francoise; Fanelli, Gaelle; Mosnegutu, Lavinia; Devaux, Frederique

    2009-12-01

    Cone beam computerized tomography is an imagery technique notably used for the maxillofacial complex or a complete or limited exploration of maxillo-mandibular and dento-alveolar structures. Typically, this technique is implemented with devices which are different from scanners in various respects (performance of several linear cuts, use of an open cone beam). Based on a literature survey, this document reports an assessment which aimed at determining technical and dosimetric performances of the device, potential benefits in terms of diagnosis and therapy with respect to existing imagery techniques, specifications and role of this technique in odonto-stomatology, maxillofacial surgery, and even in ENT, and operation conditions and training to perform this act

  11. Mandibular condyle position in cone beam computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Hyoung Joo; Kim, Gyu Tae; Choi, Yong Suk; Hwang, Eui Hwan [Kyung Hee Univ. School of Dentistry, Seoul (Korea, Republic of)

    2006-06-15

    To evaluate position of the mandibular condyle within articular fossa in an asymptomatic population radiographically by a cone beam computed tomography. Cone beam computed tomography of 60 temporomandibular joints was performed on 15 males and 15 females with no history of any temporomandibular disorders, or any other orthodontic or photoconductors treatments. Position of mandibular condyle within articular fossa at centric occlusion was evaluated. A statistical evaluation was done using a SPSS. In the sagittal views, mandibular condyle within articular fossa was laterally located at central section. Mandibular condyles in the right and left sides were showed asymmetric positional relationship at medial, central, and lateral sections. Mandibular condyle within articular fossa in an asymptomatic population was observed non-concentric position in the sagittal and coronal views.

  12. Mandibular condyle position in cone beam computed tomography

    International Nuclear Information System (INIS)

    Hwang, Hyoung Joo; Kim, Gyu Tae; Choi, Yong Suk; Hwang, Eui Hwan

    2006-01-01

    To evaluate position of the mandibular condyle within articular fossa in an asymptomatic population radiographically by a cone beam computed tomography. Cone beam computed tomography of 60 temporomandibular joints was performed on 15 males and 15 females with no history of any temporomandibular disorders, or any other orthodontic or photoconductors treatments. Position of mandibular condyle within articular fossa at centric occlusion was evaluated. A statistical evaluation was done using a SPSS. In the sagittal views, mandibular condyle within articular fossa was laterally located at central section. Mandibular condyles in the right and left sides were showed asymmetric positional relationship at medial, central, and lateral sections. Mandibular condyle within articular fossa in an asymptomatic population was observed non-concentric position in the sagittal and coronal views

  13. Clinical diagnosis of high myopia with cone dystrophy

    Directory of Open Access Journals (Sweden)

    Qing-He Li

    2014-04-01

    Full Text Available High myopia associated with cone dystrophy is relatively rare in clinical practice. Because the two diseases have a certain genetic predisposition, with the disease developed, clinical examination and clinical symptoms have some similarities, one disease diagnosis is easily confused or masked by the other diagnosis, especially in the face of patients with high myopia associated abnormalities, we should carefully screen abnormal visual function of its own or combined cone dystrophy diagnosis. In addition, the development of the disease may mutually reinforce, aggravate the symptoms of each other, which is likely to cause mission or misdiagnosis, or delay the proper treatment. Therefore, it is clinically difficult to correct and comprehensively and timely diagnosis.

  14. A Clinical Evaluation of Cone Beam Computed Tomography

    Science.gov (United States)

    2015-06-01

    morphology based on conventional imaging • Identification of root canal system anomalies and determination of root curvature • Diagnosis of dental ...A CLINICAL EVALUATION OF CONE BEAM COMPUTED TOMOGRAPHY by Thomas Patrick Cairnll, D.D.S. Commander, Dental Corps United States Navy A thesis...submitted to the Faculty of the Endodontics Graduate Program Naval Postgraduate Dental School Uniformed Services University of the Health Sciences in

  15. gVSγ coupling constant in light cone QCD

    International Nuclear Information System (INIS)

    Aydin, C.; Keskin, F.; Yilmaz, A. H.; Aydin, S. H.

    2011-01-01

    We recalculated the coupling constants g φσγ , g φa 0 γ , g ωσγ , g a 0 ωγ , g ρσγ , and g a 0 ργ by taking into account the contributions of the three-particle up to twist-4 distribution amplitudes of the photon involving quark-gluon and quark-anti-quark-photon fields in the light-cone sum-rule framework.

  16. Mitogenomic phylogeny of cone snails endemic to Senegal.

    Science.gov (United States)

    Abalde, Samuel; Tenorio, Manuel J; Afonso, Carlos M L; Zardoya, Rafael

    2017-07-01

    Cone snails attain in Senegal one of their highest peaks of species diversity throughout the continental coast of Western Africa. A total of 15 endemic species have been described, all placed in the genus Lautoconus. While there is ample data regarding the morphology of the shell and the radular tooth of these species, virtually nothing is known regarding the genetic diversity and phylogenetic relationships of one of the most endangered groups of cones. In this work, we determined the complete or near-complete (only lacking the control region) mitochondrial (mt) genomes of 17 specimens representing 11 endemic species (Lautoconus belairensis, Lautoconus bruguieresi, Lautoconus cacao, Lautoconus cloveri, Lautoconus cf. echinophilus, Lautoconus guinaicus, Lautoconus hybridus, Lautoconus senegalensis, Lautoconus mercator, Lautoconus taslei, and Lautoconus unifasciatus). We also sequenced the complete mt genome of Lautoconus guanche from the Canary Islands, which has been related to the cones endemic to Senegal. All mt genomes share the same gene arrangement, which conforms to the consensus reported for Conidae, Neogastropoda and Caenogastropoda. Phylogenetic analyses using probabilistic methods recovered three major lineages, whose divergence coincided in time with sea level and ocean current changes as well as temperature fluctuations during the Messinian salinity crisis and the Plio-Pleistocene transition. Furthermore, the three lineages corresponded to distinct types of radular tooth (robust, small, and elongated), suggesting that dietary specialization could be an additional evolutionary driver in the diversification of the cones endemic to Senegal. The reconstructed phylogeny showed several cases of phenotypic convergence (cryptic species) and questions the validity of some species (ecotypes or phenotypic plasticity), both results having important taxonomic and conservation consequences. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. The quintic interaction vertex in light-cone gravity

    International Nuclear Information System (INIS)

    Ananth, Sudarshan

    2008-01-01

    We consider pure gravity in light-cone gauge and derive the complete quintic interaction vertex. Up to quartic order, the Kawai-Lewellen-Tye (KLT) relations can be made manifest at the level of the Einstein-Hilbert Lagrangian. The quintic interaction vertex represents an essential first step in further extending the off-shell validity of the KLT relations to higher order vertices

  18. Endodontic practice management with cone-beam computed tomography

    OpenAIRE

    Priyank Sethi; Ritu Tiwari; Maneesha Das; Mahesh Pratap Singh; Manish Agarwal; Alfred Joseph Ravikumar

    2017-01-01

    Traditionally, conventional periapical radiology formed the backbone of endodontics for diagnosis, treatment planning, and management. One of the major associated gripes being the technique created two-dimensional images of three-dimensional (3D) structures, suffered magnification, superimposition, and distortion, leading to compromised diagnostic information. The need to analyze the area of interest in all the possible planes led to the introduction of cone-beam computed tomography (CBCT), a...

  19. Cone beam computed tomography in Endodontics - a review.

    Science.gov (United States)

    Patel, S; Durack, C; Abella, F; Shemesh, H; Roig, M; Lemberg, K

    2015-01-01

    Cone beam computed tomography (CBCT) produces undistorted three-dimensional information of the maxillofacial skeleton, including the teeth and their surrounding tissues with a lower effective radiation dose than computed tomography. The aim of this paper is to: (i) review the current literature on the applications and limitations of CBCT; (ii) make recommendations for the use of CBCT in Endodontics; (iii) highlight areas of further research of CBCT in Endodontics. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  20. Use of Cone Beam Computed Tomography in Endodontics

    Science.gov (United States)

    Scarfe, William C.; Levin, Martin D.; Gane, David; Farman, Allan G.

    2009-01-01

    Cone Beam Computed Tomography (CBCT) is a diagnostic imaging modality that provides high-quality, accurate three-dimensional (3D) representations of the osseous elements of the maxillofacial skeleton. CBCT systems are available that provide small field of view images at low dose with sufficient spatial resolution for applications in endodontic diagnosis, treatment guidance, and posttreatment evaluation. This article provides a literature review and pictorial demonstration of CBCT as an imaging adjunct for endodontics. PMID:20379362

  1. The Capabilities of Nurse Educators (CONE) questionnaire: Development and evaluation.

    Science.gov (United States)

    McAllister, Margaret; Flynn, Trudi

    2016-04-01

    To inspire excellent clinicians to become educators, the role of the nurse educator needs to be more fully defined. Capabilities rather than competencies may better describe advanced professional practice. To develop an effective measure of the multifaceted complexity of the nurse educator role, which will enable nurse educators to (1) self-assess their capability set, (2) identify areas for professional development, and (3) evaluate professional development interventions. A questionnaire (with 6 subsets) interrogating nurse educator capabilities was developed through wide professional consultation and an expert working group, and evaluated. Statistical analyses investigated internal consistency, internal correlation of items, relationship to professional practice data (also collected via questionnaire), and test-retest reliability of the questionnaire and subsets. Nurse educators (266) working within universities and health services in Australia and New Zealand. Analyses resulted in a 93-item Capabilities of Nurse Educators (CONE) questionnaire, with six subsets measuring Teaching Knowledge and Practice, Drawing from Nursing Knowledge, Teaching Relationships, Leadership, Research Orientation and Research Action. The questionnaire and subsets demonstrated internal validity (Cronbach's α ≥ .9). Reliability in this population was supported via significant differences between ranked questionnaire scores in ordinal categories of data collected about professional practice. The 8-week test-retest analysis supported the reliability of the CONE over time and suggested the questionnaire could be useful to evaluate the success of professional development activities. The CONE questionnaire proved useful for measuring the complex capabilities of nurse educators in the academic and health service contexts studied and may assist educators to self-assess their capability sets and identify areas for professional development. It also shows promise as an evaluation tool for

  2. Cone-beam computed tomography and the dentist.

    Science.gov (United States)

    MacDonald, David

    2017-02-01

    Although cone-beam computed tomography (CBCT) is just 15 years old, it has revolutionized the practice of dentistry, so much so, there is hardly a dental specialty which has not been affected by this technology. Nevertheless, it presents the dentist with a number of important challenges. An initial steep learning curve must be addressed without unnecessary exposure to the patient. This is particularly important when the patient is a child. © 2015 Wiley Publishing Asia Pty Ltd.

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

    Science.gov (United States)

    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.

  4. Comparison of Asymmetric and Ice-cream Cone Models for Halo Coronal Mass Ejections

    Science.gov (United States)

    Na, H.; Moon, Y.

    2011-12-01

    Halo coronal mass ejections (HCMEs) are major cause of the geomagnetic storms. To minimize the projection effect by coronagraph observation, several cone models have been suggested: an ice-cream cone model, an asymmetric cone model etc. These models allow us to determine the three dimensional parameters of HCMEs such as radial speed, angular width, and the angle between sky plane and central axis of the cone. In this study, we compare these parameters obtained from different models using 48 well-observed HCMEs from 2001 to 2002. And we obtain the root mean square error (RMS error) between measured projection speeds and calculated projection speeds for both cone models. As a result, we find that the radial speeds obtained from the models are well correlated with each other (R = 0.86), and the correlation coefficient of angular width is 0.6. The correlation coefficient of the angle between sky plane and central axis of the cone is 0.31, which is much smaller than expected. The reason may be due to the fact that the source locations of the asymmetric cone model are distributed near the center, while those of the ice-cream cone model are located in a wide range. The average RMS error of the asymmetric cone model (85.6km/s) is slightly smaller than that of the ice-cream cone model (87.8km/s).

  5. Analysis of macular cone photoreceptors in a case of occult macular dystrophy

    Directory of Open Access Journals (Sweden)

    Tojo N

    2013-05-01

    Full Text Available Naoki Tojo Tomoko Nakamura Hironori Ozaki Miyako Oka Toshihiko Oiwake Atsushi HayashiDepartment of Ophthalmology, University of Toyama, Toyama, JapanPurpose: To investigate changes in cone photoreceptors with adaptive optics (AO fundus imaging and spectral domain optical coherence tomography (SD-OCT in a case of occult macular dystrophy (OMD.Patient and methods: Both eyes of a 42-year-old woman diagnosed with OMD were examined. We used an AO fundus camera to obtain images of cone photoreceptors in the macula of the OMD subject and five healthy control subjects. Correlations between the AO images and the SD-OCT images were examined. Cone photoreceptors in eight areas in the macula of OMD and healthy control subjects were analyzed and compared.Results: SD-OCT showed a loss of the cone outer-segment tips line outside of the fovea in both eyes of the subject with OMD. The left eye with decreased visual acuity showed a discontinuous photoreceptor inner-segment and outer-segment line and cone outer-segment tips line at the fovea in SD-OCT and loss of cone mosaics as a dark spot in the AO image. In panoramic AO images and cone-density maps, less cone density was observed in a ring-like region outside the fovea than in the peripheral retina. In most of the areas examined, the cone densities were lower in the OMD eyes than in the healthy control eyes.Conclusions: Cone densities in the macula of the OMD patient were greatly decreased. AO images were found to be useful to evaluate morphologic changes in cone photoreceptors in patients with OMD.Keywords: occult macular dystrophy, adaptive optics, cone photoreceptor, cone analysis, optical coherence tomography

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

    Science.gov (United States)

    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

  7. Cone visual pigments are present in gecko rod cells.

    Science.gov (United States)

    Kojima, D; Okano, T; Fukada, Y; Shichida, Y; Yoshizawa, T; Ebrey, T G

    1992-08-01

    The Tokay gecko (Gekko gekko), a nocturnal lizard, has two kinds of visual pigments, P467 and P521. In spite of the pure-rod morphology of the photoreceptor cells, the biochemical properties of P521 and P467 resemble those of iodopsin (the chicken red-sensitive cone visual pigment) and rhodopsin, respectively. We have found that the amino acid sequence of P521 deduced from the cDNA was very similar to that of iodopsin. In addition, P467 has the highest homology with the chicken green-sensitive cone visual pigment, although it also has a relatively high homology with rhodopsins. These results give additional strength to the transmutation theory of Walls [Walls, G. L. (1934) Am. J. Ophthalmol. 17, 892-915], who proposed that the rod-shaped photoreceptor cells of lizards have been derived from ancestral cone-like photoreceptors. Apparently amino acid sequences of visual pigments are less changeable than the morphology of the photoreceptor cells in the course of evolution.

  8. Anatomical structure of lingual foramen in cone beam computed tomography

    International Nuclear Information System (INIS)

    Ki, Min Woo; Hwang, Eui Hwan; Lee, Sang Rae

    2004-01-01

    To evaluate whether cone beam computed tomography can depict the distribution, position, frequency, relative vertical dimension, and the diameter of the lingual foramen and direction of lingual bone canal. Cone beam computed tomography of mandible was performed on 25 males and 25 females with no history of any orthodontic treatments or any other dental surgeries. A statistical comparison was done on the mean values of males and females. In the location and distribution of lingual foramina, median lingual foramen was found in all subjects and lateral lingual foramen in 58%. In the lateral lingual foramen, bilateral type was found in 28% and unilateral type in 30%. In the number of lingual foramina, median lingual foramen had two foramina and lateral lingual foramen had one foramen, mostly. In the relative mean vertical dimension of lingual foramina, median lingual foramen was 0.03 ± 0.08, and both lateral lingual foramina was 0.20 ± 0.04. The mean diameter of lingual foramina, median lingual foramen was 0.9 mm ± 0.28, right lateral lingual foramen was 0.92 mm ± 0.23, and left lateral lingual foramen was 0.88 mm ± 0.27. The most frequent direction of the lingual bone canals, median lingual bone canal proceeded in anteroinferior direction and lateral lingual bone canal in anterosuperolateral direction. Cone beam computed tomography can be helpful for surgery and implantation on the mandibular area. Radiologist should be aware of this anatomical feature and its possible implications.

  9. Interpretation of Seismic Cone Penetration Testing in Silty Soil

    DEFF Research Database (Denmark)

    Holmsgaard, Rikke; Ibsen, Lars Bo; Nielsen, Benjaminn Nordahl

    2016-01-01

    Five Seismic Cone Penetration Tests (SCPT) were conducted at a test site in northern Denmark where the subsoil consists primarily of sandy silt with clay bands. A portion of the test data were collected every 0.5 m to compare the efficacy of closely-spaced down-hole data collection on the computa......Five Seismic Cone Penetration Tests (SCPT) were conducted at a test site in northern Denmark where the subsoil consists primarily of sandy silt with clay bands. A portion of the test data were collected every 0.5 m to compare the efficacy of closely-spaced down-hole data collection...... on the computation of shear wave velocity. A minimum of eight seismic tests were completed at each depth in order to examine the reliability of shear wave velocity data, as well as to assess the impact of the time interval between CPT termination and seismic test initiation on SCPT results. The shear wave velocity...... increased the variability of the shear wave velocity and that time interval between seismic tests is insignificant. Correlation between shear wave velocity and cone resistance for silty soils were also determined and assessed relative to other published data on multiple soil types....

  10. Camera Layout Design for the Upper Stage Thrust Cone

    Science.gov (United States)

    Wooten, Tevin; Fowler, Bart

    2010-01-01

    Engineers in the Integrated Design and Analysis Division (EV30) use a variety of different tools to aid in the design and analysis of the Ares I vehicle. One primary tool in use is Pro-Engineer. Pro-Engineer is a computer-aided design (CAD) software that allows designers to create computer generated structural models of vehicle structures. For the Upper State thrust cone, Pro-Engineer was used to assist in the design of a layout for two camera housings. These cameras observe the separation between the first and second stage of the Ares I vehicle. For the Ares I-X, one standard speed camera was used. The Ares I design calls for two separate housings, three cameras, and a lighting system. With previous design concepts and verification strategies in mind, a new layout for the two camera design concept was developed with members of the EV32 team. With the new design, Pro-Engineer was used to draw the layout to observe how the two camera housings fit with the thrust cone assembly. Future analysis of the camera housing design will verify the stability and clearance of the camera with other hardware present on the thrust cone.

  11. Topografia do cone medular da paca (Agouti paca, Linnaeus - 1766

    Directory of Open Access Journals (Sweden)

    Alessandra Regina Freixo Scavone

    2007-12-01

    Full Text Available Objetivamos neste trabalho determinar a esqueletopia da terminação do cone medular da paca relacionando com as vértebras lombares e sacrais, visando assim estabelecer parâmetros morfométricos e topográficos do cone medular nesta espécie. Para tanto, procedemos à dissecação, mediante incisão, rebatimento da pele, da tela subcutânea e da musculatura da região dorsal à coluna vertebral, com posterior secção e remoção dos arcos vertebrais para melhor visualização da medula espinhal. Após a individualização do cone medular, registramos os aspectos anatômicos de interesse, enfatizando seu início (base e seu término (ápice em relação às vértebras, e a partir de então efetuamos suas medidas com o auxílio de paquímetro; visando documentar nossos achados, realizamos fotografias e esquemas dos espécimes estudados.

  12. Strong Localization in Disordered Media: Analysis of the Backscattering Cone

    KAUST Repository

    Delgado, Edgar

    2012-06-01

    A very interesting effect in light propagation through a disordered system is Anderson localization of light, this phenomenon emerges as the result of multiple scattering of waves by electric inhomogeneities like spatial variations of index of refraction; as the amount of scattering is increased, light propagation is converted from quasi-diffusive to exponentially localized, with photons confined in a limited spatial region characterized by a fundamental quantity known as localization length. Light localization is strongly related to another interference phenomenon emerged from the multiple scattering effect: the coherent backscattering effect. In multiple scattering of waves, in fact, coherence is preserved in the backscattering direction and produces a reinforcement of the field flux originating an observable peak in the backscattered intensity, known as backscattering cone. The study of this peak provide quantitative information about the transport properties of light in the material. In this thesis we report a complete FDTD ab-initio study of light localization and coherent backscattering. In particular, we consider a supercontinuum pulse impinging on a sample composed of randomly positioned scatterers. We study coherent backscattering by averaging over several realizations of the sample properties. We study then the coherent backscattering cone properties as the relative permittivity of the sample is changed, relating the latter with the light localization inside the sample. We demonstrate important relationships between the width of the backscattering cone and the localization length, which shows a linear proportionality in the strong localization regime.

  13. A practical attenuation compensation method for cone beam spect

    International Nuclear Information System (INIS)

    Manglos, S.H.; Jaszczak, R.J.; Floyd, C.E.; Greer, K.L.; Coleman, R.E.

    1987-01-01

    An algorithm for attenuation compensation of cone beam SPECT images has been developed and implemented. The algorithm is based on a multiplicative post-processing method previously used for parallel and fan beam geometries. This method computes the compensation from the estimated average attenuation of photons originating from each image pixel. In the present development, a uniform attenuation coefficient inside of the body contour is assumed, although the method could be extended to include a non-uniform attenuation map. The algorithm is tested with experimental projections of a phantom obtained using a cone beam collimator. Profiles through the reconstructed images are presented as a quantitative test of the improvement due to the compensation. The algorithm provides adequate compensation for attenuation in a simple uniform cylindrical phantom, and the computational time is short compared to that expected for iterative reconstruction techniques. Also observed are image distortions in some reconstructed slices when the source distribution extends beyond the edge of the cone beam axial field-of-view

  14. An ADAM9 mutation in canine cone-rod dystrophy 3 establishes homology with human cone-rod dystrophy 9.

    Science.gov (United States)

    Goldstein, Orly; Mezey, Jason G; Boyko, Adam R; Gao, Chuan; Wang, Wei; Bustamante, Carlos D; Anguish, Lynne J; Jordan, Julie Ann; Pearce-Kelling, Susan E; Aguirre, Gustavo D; Acland, Gregory M

    2010-08-11

    To identify the causative mutation in a canine cone-rod dystrophy (crd3) that segregates as an adult onset disorder in the Glen of Imaal Terrier breed of dog. Glen of Imaal Terriers were ascertained for crd3 phenotype by clinical ophthalmoscopic examination, and in selected cases by electroretinography. Blood samples from affected cases and non-affected controls were collected and used, after DNA extraction, to undertake a genome-wide association study using Affymetrix Version 2 Canine single nucleotide polymorphism chips and 250K Sty Assay protocol. Positional candidate gene analysis was undertaken for genes identified within the peak-association signal region. Retinal morphology of selected crd3-affected dogs was evaluated by light and electron microscopy. A peak association signal exceeding genome-wide significance was identified on canine chromosome 16. Evaluation of genes in this region suggested A Disintegrin And Metalloprotease domain, family member 9 (ADAM9), identified concurrently elsewhere as the cause of human cone-rod dystrophy 9 (CORD9), as a strong positional candidate for canine crd3. Sequence analysis identified a large genomic deletion (over 20 kb) that removed exons 15 and 16 from the ADAM9 transcript, introduced a premature stop, and would remove critical domains from the encoded protein. Light and electron microscopy established that, as in ADAM9 knockout mice, the primary lesion in crd3 appears to be a failure of the apical microvilli of the retinal pigment epithelium to appropriately invest photoreceptor outer segments. By electroretinography, retinal function appears normal in very young crd3-affected dogs, but by 15 months of age, cone dysfunction is present. Subsequently, both rod and cone function degenerate. Identification of this ADAM9 deletion in crd3-affected dogs establishes this canine disease as orthologous to CORD9 in humans, and offers opportunities for further characterization of the disease process, and potential for genetic

  15. Arrival of Paleo-Indians to the Southern Cone of South America: New Clues from Mitogenomes

    Science.gov (United States)

    de Saint Pierre, Michelle; Gandini, Francesca; Perego, Ugo A.; Bodner, Martin; Gómez-Carballa, Alberto; Corach, Daniel; Angerhofer, Norman; Woodward, Scott R.; Semino, Ornella; Salas, Antonio; Parson, Walther; Moraga, Mauricio; Achilli, Alessandro; Torroni, Antonio; Olivieri, Anna

    2012-01-01

    With analyses of entire mitogenomes, studies of Native American mitochondrial DNA (mtDNA) variation have entered the final phase of phylogenetic refinement: the dissection of the founding haplogroups into clades that arose in America during and after human arrival and spread. Ages and geographic distributions of these clades could provide novel clues on the colonization processes of the different regions of the double continent. As for the Southern Cone of South America, this approach has recently allowed the identification of two local clades (D1g and D1j) whose age estimates agree with the dating of the earliest archaeological sites in South America, indicating that Paleo-Indians might have reached that region from Beringia in less than 2000 years. In this study, we sequenced 46 mitogenomes belonging to two additional clades, termed B2i2 (former B2l) and C1b13, which were recently identified on the basis of mtDNA control-region data and whose geographical distributions appear to be restricted to Chile and Argentina. We confirm that their mutational motifs most likely arose in the Southern Cone region. However, the age estimate for B2i2 and C1b13 (11–13,000 years) appears to be younger than those of other local clades. The difference could reflect the different evolutionary origins of the distinct South American-specific sub-haplogroups, with some being already present, at different times and locations, at the very front of the expansion wave in South America, and others originating later in situ, when the tribalization process had already begun. A delayed origin of a few thousand years in one of the locally derived populations, possibly in the central part of Chile, would have limited the geographical and ethnic diffusion of B2i2 and explain the present-day occurrence that appears to be mainly confined to the Tehuelche and Araucanian-speaking groups. PMID:23240014

  16. Iterative image-domain ring artifact removal in cone-beam CT

    Science.gov (United States)

    Liang, Xiaokun; Zhang, Zhicheng; Niu, Tianye; Yu, Shaode; Wu, Shibin; Li, Zhicheng; Zhang, Huailing; Xie, Yaoqin

    2017-07-01

    Ring artifacts in cone beam computed tomography (CBCT) images are caused by pixel gain variations using flat-panel detectors, and may lead to structured non-uniformities and deterioration of image quality. The purpose of this study is to propose a method of general ring artifact removal in CBCT images. This method is based on the polar coordinate system, where the ring artifacts manifest as stripe artifacts. Using relative total variation, the CBCT images are first smoothed to generate template images with fewer image details and ring artifacts. By subtracting the template images from the CBCT images, residual images with image details and ring artifacts are generated. As the ring artifact manifests as a stripe artifact in a polar coordinate system, the artifact image can be extracted by mean value from the residual image; the image details are generated by subtracting the artifact image from the residual image. Finally, the image details are compensated to the template image to generate the corrected images. The proposed framework is iterated until the differences in the extracted ring artifacts are minimized. We use a 3D Shepp-Logan phantom, Catphan©504 phantom, uniform acrylic cylinder, and images from a head patient to evaluate the proposed method. In the experiments using simulated data, the spatial uniformity is increased by 1.68 times and the structural similarity index is increased from 87.12% to 95.50% using the proposed method. In the experiment using clinical data, our method shows high efficiency in ring artifact removal while preserving the image structure and detail. The iterative approach we propose for ring artifact removal in cone-beam CT is practical and attractive for CBCT guided radiation therapy.

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

    Directory of Open Access Journals (Sweden)

    Amanda de Freitas Ferreira

    2009-01-01

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

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

    Science.gov (United States)

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

    2016-01-27

    In 1934, Gordon Walls forwarded his radical theory of retinal photoreceptor 'transmutation'. This proposed that rods and cones used for scotopic and photopic vision, respectively, were not fixed but could evolve into each other via a series of morphologically distinguishable intermediates. Walls' prime evidence came from series of diurnal and nocturnal geckos and snakes that appeared to have pure-cone or pure-rod retinas (in forms that Walls believed evolved from ancestors with the reverse complement) or which possessed intermediate photoreceptor cells. Walls was limited in testing his theory because the precise identity of visual pigments present in photoreceptors was then unknown. Subsequent molecular research has hitherto neglected this topic but presents new opportunities. We identify three visual opsin genes, rh1, sws1 and lws, in retinal mRNA of an ecologically and taxonomically diverse sample of snakes central to Walls' theory. We conclude that photoreceptors with superficially rod- or cone-like morphology are not limited to containing scotopic or photopic opsins, respectively. Walls' theory is essentially correct, and more research is needed to identify the patterns, processes and functional implications of transmutation. Future research will help to clarify the fundamental properties and physiology of photoreceptors adapted to function in different light levels. © 2016 The Author(s).

  19. Simulation of Heat Transfer in Husk Furnace with Cone Geometry Based on Conical Coordinate System

    Science.gov (United States)

    Noor, Iman; Ahmad, Faozan; Irzaman; alatas, Husin

    2017-07-01

    Simulation of Heat Transfer in Husk Furnace with Cone Geometry Based on Conical Coordinates has been performed. This simulation aimed to study the heat distribution of temperature based on conduction and convection mechanism on conical coordinate system. Fluid dynamics inside the cone of husk furnace was obtained by solving the Navier - Stokes equations with laminar flow approach. The initial temperature in all parts of the cone is room temperature, except at the bottom of the cone is 700 °C. Through numerical calculation of heat conduction and convection equation by FDM method, we got that the velocity of fluid flow at the center cone is 13.69 m/s for 45 s, 11.90 m/s for 60 s, and 7.25 m/s for 120 s, with unfixed temperature condition in the cone.

  20. Propagation of attosecond electron bunches along the cone-and-channel target

    International Nuclear Information System (INIS)

    Yang, X. H.; Shao, F. Q.; Yin, Y.; Tian, C. L.; Xu, H.; Ma, Y. Y.; Zhuo, H. B.; Yu, M. Y.

    2011-01-01

    Generation and propagation of attosecond electron bunches along a cone-and-channel target are investigated by particle-in-cell simulation. The target electrons are pulled out by the oscillating electric field of an intense laser pulse irradiating a cone target and accelerated forward along the cone walls. It is shown that the energetic electrons can be further guided and confined by a channel attached to the cone tip. The propagation of these electrons along the channel induces a strong quasistatic magnetic field as well as a sheath electric field since a part of the energetic electrons expands into the surrounding vacuum. The electromagnetic field in turn confines the surface currents. With the cone-and-channel target the energetic electrons can be much better collimated and propagate much farther than that from the classical cone target.

  1. Enhancement of the Number of Fast Electrons Generated in a Laser Inverse Cone Interaction

    International Nuclear Information System (INIS)

    Yan-Ling, Ji; Gang, Jiang; Wei-Dong, Wu; Ji-Cheng, Zhang; Yong-Jian, Tang

    2010-01-01

    Enhancement of the energy-conversion efficiency from laser to target electrons is demonstrated by two-dimensional particle-in-cell simulations in a laser-inverse cone interaction. When an intense short-pulse laser illuminates the inverse cone target, the electrons at the cone end are accelerated by the ponderomotive force. Then these electrons are guided and confined to transport along the inverse cone walls by the induced electromagnetic fields. A device consisting of inverse hollow-cone and multihole array plasma is proposed in order to increase the energy-conversion efficiency from laser to electrons. Particle-in-cell simulations present that the multiholes transpiercing the cone end help to enhance the number of fast electrons and the maximum electron energy significantly. (physics of gases, plasmas, and electric discharges)

  2. Theoretical study of laser-excited Mach cones in dusty plasmas

    International Nuclear Information System (INIS)

    Hou Lujing; Wang Younian; Miskovic, Z.L.

    2004-01-01

    A two-dimensional hydrodynamic model for a monolayer of dust particles is used to study the Mach cones excited by a moving laser beam through dusty plasmas. Numerical results for the density perturbation and the velocity distribution of dust particles exhibit both compressional and shear-wave Mach cones. It is found that the compressional Mach cones exist in cases of both supersonic and subsonic excitations, and that they consist of multiple lateral or transverse wakes. On the other hand, realization of single shear-wave Mach cones depends closely on the excitation technique, the laser scanning speed, and the discharge pressures. It is found that, when the scanning direction of the laser beam is perpendicular to the laser force, a transition from multiple compressional Mach cones to a single shear Mach cone can be achieved either by lowering the scanning speed or by increasing the discharge pressures

  3. CNTF induces regeneration of cone outer segments in a rat model of retinal degeneration.

    Directory of Open Access Journals (Sweden)

    Yiwen Li

    2010-03-01

    Full Text Available Cone photoreceptors are responsible for color and central vision. In the late stage of retinitis pigmentosa and in geographic atrophy associated with age-related macular degeneration, cone degeneration eventually causes loss of central vision. In the present work, we investigated cone degeneration secondary to rod loss in the S334ter-3 transgenic rats carrying the rhodopsin mutation S334ter.Recombinant human ciliary neurotrophic factor (CNTF was delivered by intravitreal injection to the left eye of an animal, and vehicle to the right eye. Eyes were harvested 10 days after injection. Cone outer segments (COS, and cell bodies were identified by staining with peanut agglutinin and cone arrestin antibodies in whole-mount retinas. For long-term treatment with CNTF, CNTF secreting microdevices were implanted into the left eyes at postnatal day (PD 20 and control devices into the right eyes. Cone ERG was recorded at PD 160 from implanted animals. Our results demonstrate that an early sign of cone degeneration is the loss of COS, which concentrated in many small areas throughout the retina and is progressive with age. Treatment with CNTF induces regeneration of COS and thus reverses the degeneration process in early stages of cone degeneration. Sustained delivery of CNTF prevents cones from degeneration and helps them to maintain COS and light-sensing function.Loss of COS is an early sign of secondary cone degeneration whereas cell death occurs much later. At early stages, degenerating cones are capable of regenerating outer segments, indicating the reversal of the degenerative process. Sustained delivery of CNTF preserves cone cells and their function. Long-term treatment with CNTF starting at early stages of degeneration could be a viable strategy for preservation of central vision for patients with retinal degenerations.

  4. Cone pigments in a North American marsupial, the opossum (Didelphis virginiana)

    OpenAIRE

    Jacobs, Gerald H.; Williams, Gary A.

    2010-01-01

    Only two of the four cone opsin gene families found in vertebrates are represented in contemporary eutherian and marsupial species. Recent genetic studies of two species of South American marsupial detected the presence of representatives from two of the classes of cone opsin genes and the structures of these genes predicted cone pigments with respective peaks in the ultraviolet and long-wavelength portions of the spectrum. The Virginia opossum (Didelphis virginiana), a profoundly nocturnal a...

  5. Distribution of cone density, spacing and arrangement in adult healthy retinas with adaptive optics flood illumination.

    Science.gov (United States)

    Legras, Richard; Gaudric, Alain; Woog, Kelly

    2018-01-01

    The aim of this article is to analyse cone density, spacing and arrangement using an adaptive optics flood illumination retina camera (rtx1™) on a healthy population. Cone density, cone spacing and packing arrangements were measured on the right retinas of 109 subjects at 2°, 3°, 4°, 5° and 6° of eccentricity along 4 meridians. The effects of eccentricity, meridian, axial length, spherical equivalent, gender and age were evaluated. Cone density decreased on average from 28 884 ± 3 692 cones/mm2, at 2° of eccentricity, to 15 843 ± 1 598 cones/mm2 at 6°. A strong inter-individual variation, especially at 2°, was observed. No important difference of cone density was observed between the nasal and temporal meridians or between the superior and inferior meridians. However, the horizontal and vertical meridians differed by around 14% (T-test, p<0.0001). Cone density, expressed in units of area, decreased as a function of axial length (r2 = 0.60), but remained constant (r2 = 0.05) when cone density is expressed in terms of visual angle supporting the hypothesis that the retina is stretched during the elongation of the eyeball. Gender did not modify the cone distribution. Cone density was slightly modified by age but only at 2°. The older group showed a smaller density (7%). Cone spacing increased from 6,49 ± 0,42 μm to 8,72 ± 0,45 μm respectively between 2° and 6° of eccentricity. The mosaic of the retina is mainly triangularly arranged (i.e. cells with 5 to 7 neighbors) from 2° to 6°. Around half of the cells had 6 neighbors.

  6. Formation of shatter cones by symmetric fracture bifurcation: Phenomenological modeling and validation

    Science.gov (United States)

    Kenkmann, Thomas; Hergarten, Stefan; Kuhn, Thomas; Wilk, Jakob

    2016-08-01

    Several models of shatter cone formation require a heterogeneity at the cone apex of high impedance mismatch to the surrounding bulk rock. This heterogeneity is the source of spherically expanding waves that interact with the planar shock front or the following release wave. While these models are capable of explaining the overall conical shape of shatter cones, they are not capable of explaining the subcone structure and the diverging and branching striations that characterize the surface of shatter cones and lead to the so-called horse-tailing effect. Here, we use the hierarchical arrangement of subcone ridges of shatter cone surfaces as key for understanding their formation. Tracing a single subcone ridge from its apex downward reveals that each ridge branches after some distance into two symmetrically equivalent subcone ridges. This pattern is repeated to form new branches. We propose that subcone ridges represent convex-curved fracture surfaces and their intersection corresponds to the bifurcation axis. The characteristic diverging striations are interpreted as the intersection lineations delimiting each subcone. Multiple symmetric crack branching is the result of rapid fracture propagation that may approach the Raleigh wave speed. We present a phenomenological model that fully constructs the shatter cone geometry to any order. The overall cone geometry including apex angle of the enveloping cone and the degree of concavity (horse-tailing) is largely governed by the convexity of the subcone ridges. Straight cones of various apical angles, constant slope, and constant bifurcation angles form if the subcone convexity is low (30°). Increasing subcone convexity leads to a stronger horse-tailing effect and the bifurcation angles increase with increasing distance from the enveloping cone apex. The model predicts possible triples of enveloping cone angle, bifurcation angle, and subcone angle. Measurements of these quantities on four shatter cones from different

  7. Superior performance of cone beam tomography in detecting a calcaneus fracture

    Directory of Open Access Journals (Sweden)

    Lohse, Christian

    2015-11-01

    Full Text Available Cone beam computed tomography is a state-of-the-art imaging tool, initially developed for dental and maxillofacial application. With its high resolution and low radiation dose, cone beam tomography has been expanding its application fields, for example, to diagnosis of traumata and fractures in the head and neck area. In this study, we demonstrate superior and satisfactory performance of cone beam tomography for the imaging of a calcaneus fracture in comparison to conventional and computed tomography.

  8. Topological Vector Space-Valued Cone Metric Spaces and Fixed Point Theorems

    Directory of Open Access Journals (Sweden)

    Radenović Stojan

    2010-01-01

    Full Text Available We develop the theory of topological vector space valued cone metric spaces with nonnormal cones. We prove three general fixed point results in these spaces and deduce as corollaries several extensions of theorems about fixed points and common fixed points, known from the theory of (normed-valued cone metric spaces. Examples are given to distinguish our results from the known ones.

  9. A comparative evaluation of root canal area increase using three different nickel-titanium rotary systems: An ex vivo cone-beam computed tomographic analysis.

    Science.gov (United States)

    Deka, Adrija; Bhuyan, A C; Bhuyan, Darpana

    2015-01-01

    The present study was undertaken to compare and evaluate the area increase of root canals with ProTaper, iRaCe and Revo-S systems using cone beam computed tomography for analysis. Forty five extracted human mandibular premolars having single canal and straight root were collected. Teeth were randomly assigned to three groups (n=15). Samples were decoronized by maintaining root length at 14 mm. Pre-instrumentation cone beam computed tomography scan was done after stabilizing the samples on wax blocks. The working length was determined at 1 mm short from the apical foramen by using a ISO 15 K-file tip protruding at apical foramen. Preparation was carried out according to the manufacturer's instructions. Finally, canals were instrumented upto 30/.06 apically for each group. After each instrumentation, root canals were irrigated with 2ml of 3% sodium hypochlorite solution followed by 2 ml of 17% EDTA solution. Final irrigation was done with 5ml of saline. Post instrumentation cone beam computed tomography scans of all samples in the 3 groups were acquired. Mean percentage of area increase in different thirds of the canal was highest for ProTaper followed by i-RaCe and Revo-s system which was statistically significant. Root canal area increase was highest for ProTaper followed by i-Race and Revo-S systems.

  10. A comparative evaluation of root canal area increase using three different nickel-titanium rotary systems: An ex vivo cone-beam computed tomographic analysis

    Directory of Open Access Journals (Sweden)

    Adrija Deka

    2015-01-01

    Full Text Available Background and Objectives: The present study was undertaken to compare and evaluate the area increase of root canals with ProTaper, iRaCe and Revo-S systems using cone beam computed tomography for analysis. Materials and Methodology: Forty five extracted human mandibular premolars having single canal and straight root were collected. Teeth were randomly assigned to three groups (n=15. Samples were decoronized by maintaining root length at 14 mm. Pre-instrumentation cone beam computed tomography scan was done after stabilizing the samples on wax blocks. The working length was determined at 1 mm short from the apical foramen by using a ISO 15 K-file tip protruding at apical foramen. Preparation was carried out according to the manufacturer′s instructions. Finally, canals were instrumented upto 30/.06 apically for each group. After each instrumentation, root canals were irrigated with 2ml of 3% sodium hypochlorite solution followed by 2 ml of 17% EDTA solution. Final irrigation was done with 5ml of saline. Post instrumentation cone beam computed tomography scans of all samples in the 3 groups were acquired. Results: Mean percentage of area increase in different thirds of the canal was highest for ProTaper followed by i-RaCe and Revo-s system which was statistically significant. Interpretation and Conclusion: Root canal area increase was highest for ProTaper followed by i-Race and Revo-S systems.

  11. Interactions between multiple supermassive black holes in galactic nuclei: a solution to the final parsec problem

    Science.gov (United States)

    Ryu, Taeho; Perna, Rosalba; Haiman, Zoltán; Ostriker, Jeremiah P.; Stone, Nicholas C.

    2018-01-01

    Using few-body simulations, we investigate the evolution of supermassive black holes (SMBHs) in galaxies (M* = 1010-1012 M⊙ at z = 0) at 0 orbital eccentricity. Our full loss cone treatment, albeit more approximate, suggests that the eccentricity becomes even higher when GWs become dominant, leading to rapid coalescences (binary lifetime ≲1 Gyr). Despite the lower merger rates in the empty loss cone case, due to their higher mass ratios and lower redshifts, the GWB in the full/empty loss cone models are comparable (0.70 × 10-15 and 0.53 × 10-15 at a frequency of 1 yr-1, respectively). Finally, we compute the effects of high eccentricities on the GWB spectrum.

  12. Particle simulations of high-intensity laser interaction with cone targets

    Science.gov (United States)

    Nikolić, L.; Škorić, M. M.; Ishiguro, S.; Sakagami, H.; Vidal, F.; Johnston, T.

    2008-05-01

    Hollow cone-shaped overdense plasma targets were used to investigate the generation and transport of fast particles in a high-intensity laser-matter interaction. Using 2d PIC simulations we examine cone, cone-wire and cone with an open tip target designs. Localization of electron jets and an angular spread are found in all cases of the laser-cone interaction. However, in the cone-wire geometry, at later times, the charge separation and radial electric fields around the wire collimate electron streams with an electron hot spot at the front end of the wire. The main mechanism of the electron transport in the targets is the reflection of electrons from the potential walls of the cone surface, and no significant surface electron transport is observed. Furthermore, the presence of harmonics in the reflected light suggests that the field intensity in the cone can be enhanced not only by simple multiple reflection but also by the field modulation due to harmonics generation. Moreover, it is found that the laser interaction with the open-tip cone can efficiently generate trains of short (laser axis.

  13. Mutations in PCDH21 cause autosomal recessive cone-rod dystrophy

    DEFF Research Database (Denmark)

    Østergaard, Elsebet; Batbayli, M; Dunø, Morten

    2010-01-01

    Cone-rod dystrophy is a retinal dystrophy with early loss of cone photoreceptors and a parallel or subsequent loss of rod photoreceptors. It may be syndromic, but most forms are non-syndromic with autosomal dominant, autosomal recessive or X-linked recessive inheritance.......Cone-rod dystrophy is a retinal dystrophy with early loss of cone photoreceptors and a parallel or subsequent loss of rod photoreceptors. It may be syndromic, but most forms are non-syndromic with autosomal dominant, autosomal recessive or X-linked recessive inheritance....

  14. RBX2 maintains final retinal cell position in a DAB1-dependent and -independent fashion.

    Science.gov (United States)

    Fairchild, Corinne L; Hino, Keiko; Han, Jisoo S; Miltner, Adam M; Peinado Allina, Gabriel; Brown, Caileigh E; Burns, Marie E; La Torre, Anna; Simó, Sergi

    2018-02-02

    The laminated structure of the retina is fundamental for the organization of the synaptic circuitry that translates light input into patterns of action potentials. However, the molecular mechanisms underlying cell migration and layering of the retina are poorly understood. Here, we show that RBX2, a core component of the E3 ubiquitin ligase CRL5, is essential for retinal layering and function. RBX2 regulates the final cell position of rod bipolar cells, cone photoreceptors and Muller glia. Our data indicate that sustained RELN/DAB1 signaling, triggered by depletion of RBX2 or SOCS7 - a CRL5 substrate adaptor known to recruit DAB1 - causes rod bipolar cell misposition. Moreover, whereas SOCS7 also controls Muller glia cell lamination, it is not responsible for cone photoreceptor positioning, suggesting that RBX2, most likely through CRL5 activity, controls other signaling pathways required for proper cone localization. Furthermore, RBX2 depletion reduces the number of ribbon synapses and disrupts cone photoreceptor function. Together, these results uncover RBX2 as a crucial molecular regulator of retina morphogenesis and cone photoreceptor function. © 2018. Published by The Company of Biologists Ltd.

  15. Evaluation of Faun MLC-70 Trackway Mat System Under Simulated F-15 Traffic

    Science.gov (United States)

    2014-05-01

    penetrometer (DCP) tests were conducted, according to ASTM D6951, on the test section at three quarter-point locations (10, 20, and 30 ft from the...International. 2009. Standard test method for use of the dynamic cone penetrometer in shallow pavement applications. Designation D6951/6591M -09. West

  16. An Efficient Estimation Method for Reducing the Axial Intensity Drop in Circular Cone-Beam CT

    Directory of Open Access Journals (Sweden)

    Lei Zhu

    2008-01-01

    Full Text Available Reconstruction algorithms for circular cone-beam (CB scans have been extensively studied in the literature. Since insufficient data are measured, an exact reconstruction is impossible for such a geometry. If the reconstruction algorithm assumes zeros for the missing data, such as the standard FDK algorithm, a major type of resulting CB artifacts is the intensity drop along the axial direction. Many algorithms have been proposed to improve image quality when faced with this problem of data missing; however, development of an effective and computationally efficient algorithm remains a major challenge. In this work, we propose a novel method for estimating the unmeasured data and reducing the intensity drop artifacts. Each CB projection is analyzed in the Radon space via Grangeat's first derivative. Assuming the CB projection is taken from a parallel beam geometry, we extract those data that reside in the unmeasured region of the Radon space. These data are then used as in a parallel beam geometry to calculate a correction term, which is added together with Hu’s correction term to the FDK result to form a final reconstruction. More approximations are then made on the calculation of the additional term, and the final formula is implemented very efficiently. The algorithm performance is evaluated using computer simulations on analytical phantoms. The reconstruction comparison with results using other existing algorithms shows that the proposed algorithm achieves a superior performance on the reduction of axial intensity drop artifacts with a high computation efficiency.

  17. Auto calibration of a cone-beam-CT

    International Nuclear Information System (INIS)

    Gross, Daniel; Heil, Ulrich; Schulze, Ralf; Schoemer, Elmar; Schwanecke, Ulrich

    2012-01-01

    Purpose: This paper introduces a novel autocalibration method for cone-beam-CTs (CBCT) or flat-panel CTs, assuming a perfect rotation. The method is based on ellipse-fitting. Autocalibration refers to accurate recovery of the geometric alignment of a CBCT device from projection images alone, without any manual measurements. Methods: The authors use test objects containing small arbitrarily positioned radio-opaque markers. No information regarding the relative positions of the markers is used. In practice, the authors use three to eight metal ball bearings (diameter of 1 mm), e.g., positioned roughly in a vertical line such that their projection image curves on the detector preferably form large ellipses over the circular orbit. From this ellipse-to-curve mapping and also from its inversion the authors derive an explicit formula. Nonlinear optimization based on this mapping enables them to determine the six relevant parameters of the system up to the device rotation angle, which is sufficient to define the geometry of a CBCT-machine assuming a perfect rotational movement. These parameters also include out-of-plane rotations. The authors evaluate their method by simulation based on data used in two similar approaches [L. Smekal, M. Kachelriess, S. E, and K. Wa, “Geometric misalignment and calibration in cone-beam tomography,” Med. Phys. 31(12), 3242–3266 (2004); K. Yang, A. L. C. Kwan, D. F. Miller, and J. M. Boone, “A geometric calibration method for cone beam CT systems,” Med. Phys. 33(6), 1695–1706 (2006)]. This allows a direct comparison of accuracy. Furthermore, the authors present real-world 3D reconstructions of a dry human spine segment and an electronic device. The reconstructions were computed from projections taken with a commercial dental CBCT device having two different focus-to-detector distances that were both calibrated with their method. The authors compare their reconstruction with a reconstruction computed by the manufacturer of the

  18. Quality assessment and enhancement for cone-beam computed tomography in dental imaging

    International Nuclear Information System (INIS)

    Jeon, Sung Chae

    2006-02-01

    %. In interpolation procedure in CBCT, the scatter components variation was noticeably high in the range from 40 .deg. to 140 .deg. and from 220 .deg. to 320 .deg. because of the larger variations of SPR due to the thickness of head phantom. So, Non-equiangular sampling in that range was a very effective way to reduce estimation error of interpolation as well as the number of the samples. Modern CBCT systems have commonly used FDK algorithm for volumetric reconstruction. But FDK algorithm has computational complexity that requires long reconstruction time. In order to make it applicable in a clinical setting, it is important that the development of an algorithm to reasonably reduce the required amount of time. The efficient implementation of FDK algorithm for fast reconstruction have implemented and optimized. By removing the redundant instructions which happen in circular cone-beam reconstruction procedure using the symmetry property, the reconstruction performance was considerably enhanced. Finally, maximizing the computing capability on the dual CPU computer by multi-threads, the performance for speed issue in the FDK algorithm was more efficiently optimized

  19. Spray Modeling for Outwardly-Opening Hollow-Cone Injector

    KAUST Repository

    Sim, Jaeheon

    2016-04-05

    The outwardly-opening piezoelectric injector is gaining popularity as a high efficient spray injector due to its precise control of the spray. However, few modeling studies have been reported on these promising injectors. Furthermore, traditional linear instability sheet atomization (LISA) model was originally developed for pressure swirl hollow-cone injectors with moderate spray angle and toroidal ligament breakups. Therefore, it is not appropriate for the outwardly-opening injectors having wide spray angles and string-like film structures. In this study, a new spray injection modeling was proposed for outwardly-opening hollow-cone injector. The injection velocities are computed from the given mass flow rate and injection pressure instead of ambiguous annular nozzle geometry. The modified Kelvin-Helmholtz and Rayleigh-Taylor (KH-RT) breakup model is used with adjusted initial Sauter mean diameter (SMD) for modeling breakup of string-like structure. Spray injection was modeled using a Lagrangian discrete parcel method within the framework of commercial CFD software CONVERGE, and the new model was implemented through the user-defined functions. A Siemens outwardly-opening hollow-cone spray injector was characterized and validated with existing experimental data at the injection pressure of 100 bar. It was found that the collision modeling becomes important in the current injector because of dense spray near nozzle. The injection distribution model showed insignificant effects on spray due to small initial droplets. It was demonstrated that the new model can predict the liquid penetration length and local SMD with improved accuracy for the injector under study.

  20. Spin-orbit band gaps and destruction of Dirac cones

    Science.gov (United States)

    Yakovkin, I. N.

    2017-08-01

    The relativistic band structures of the IV group honeycomb monolayers, from graphene to plumbene (C-Si-Ge-Sn-Pb), have been calculated within DFT in Local Density Approximation (LDA). Basing on the obtained results, we suggest that the spin-orbit coupling leads to opening of the band gaps and therefore will unavoidably cause the destruction of the perfect shape of Dirac cones which is responsible for the existence of the massless Fermions. The applicability of ordinary non-relativistic DFT calculations of bands for graphene-like layered structures is discussed in this regard.

  1. Viscous flow over spinning cones at angle of attack.

    Science.gov (United States)

    Lin, T. C.; Rubin, S. G.

    1973-01-01

    A numerical finite-difference method is developed for evaluating the Magnus coefficients on spinning cones in laminar flow. The merged layer, the strong interaction region, and the downstream boundary layer are all considered. The numerical method is a predictor-corrector scheme developed for three-dimensional flows with or without crossflow diffusion. This method is particularly useful in problems in which a symmetry plane does not exist. Several contributions to the Magnus force and moments are considered. These include asymmetries in displacement thickness, centrifugal force and crossflow shear, and the effects of crossflow separation and vortex formation. Comparisons are made with experimental data and other analyses.

  2. Geometry calibration method for a cone-beam CT system.

    Science.gov (United States)

    Yang, Hongkai; Kang, Kejun; Xing, Yuxiang

    2017-05-01

    The positioning accuracy of each component is important to ensure the image quality of cone-beam CT. However, accurate positioning is not easy and requires experience and time. The option is to calibrate the geometric parameters and then plug them into a reconstruction algorithm which is the preferred solution in practice. In this case, the image quality is determined by the accuracy and precision of the calibration method. This work describes a method to independently calibrate an imaging system in each pose (projection angle) for a cone-beam CT with a nonideal circular trajectory. The calibration method uses a phantom with 12 beads on 2 planes that are observed on the radiographic images. This pose-independent calibration method (PIC) can decorrelate the relationships among the geometric parameters so that the parameters can be estimated one-by-one. This simplifies the calibration process. Besides the pose-independent calibration method, this paper also describes an extended calibration method with additional constraints on the system geometry. Both methods are validated with numerical simulations and then experimentally on a practical system with a scanning object loosely supported by rotating wheels. The object rotates during the CT data acquisition. The angular and pose information of the CT system are not accurately known a priori in this case. The numerical simulations and the experiments both provide satisfactory results. The relative error of the calibrated source-to-detector distance in the simulation is less than 0.1%. The errors in the calibrated roll, pitch, and yaw angles are less than 0.04°. A sensitivity study using various bead position uncertainties in random directions shows that the pose-independent calibration method is robust to measurement errors. Tests were also done with a nonideal circular trajectory for further validation. Images reconstructed using the geometric parameters from both the pose-independent and the extended calibration

  3. Dose calculation based on Cone Beam CT images

    DEFF Research Database (Denmark)

    Slot Thing, Rune

    Cone beam CT (CBCT) imaging is frequently used in modern radiotherapy to ensure the proper positioning of the patient prior to each treatment fraction. With the increasing use of CBCT imaging for image guidance, interest has grown in exploring the potential use of these 3– or 4–D medical images...... image lag, scatter within the CBCT detector assembly, x-ray beam hardening from the patient, and truncation of the CBCT field of view were implemented for clinical CBCT imaging of lung cancer patients. Through the artefact corrections, Hounsfield Units in the CBCT images were recovered and shown...

  4. Response of Spectral Reflectances and Vegetation Indices on Varying Juniper Cone Densities

    Directory of Open Access Journals (Sweden)

    Guillermo E. Ponce-Campos

    2013-10-01

    Full Text Available Juniper trees are widely distributed throughout the world and are common sources of allergies when microscopic pollen grains are transported by wind and inhaled. In this study, we investigated the spectral influences of pollen-discharging male juniper cones within a juniper canopy. This was done through a controlled outdoor experiment involving ASD FieldSpec Pro Spectroradiometer measurements over juniper canopies of varying cone densities. Broadband and narrowband spectral reflectance and vegetation index (VI patterns were evaluated as to their sensitivity and their ability to discriminate the presence of cones. The overall aim of this research was to assess remotely sensed phenological capabilities to detect pollen-bearing juniper trees for public health applications. A general decrease in reflectance values with increasing juniper cone density was found, particularly in the Green (545–565 nm and NIR (750–1,350 nm regions. In contrast, reflectances in the shortwave-infrared (SWIR, 2,000 nm to 2,350 nm region decreased from no cone presence to intermediate amounts (90 g/m2 and then increased from intermediate levels to the highest cone densities (200 g/m2. Reflectance patterns in the Red (620–700 nm were more complex due to shifting contrast patterns in absorptance between cones and juniper foliage, where juniper foliage is more absorbing than cones only within the intense narrowband region of maximum chlorophyll absorption near 680 nm. Overall, narrowband reflectances were more sensitive to cone density changes than the equivalent MODIS broadbands. In all VIs analyzed, there were significant relationships with cone density levels, particularly with the narrowband versions and the two-band vegetation index (TBVI based on Green and Red bands, a promising outcome for the use of phenocams in juniper phenology trait studies. These results indicate that spectral indices are sensitive to certain juniper phenologic traits that can potentially be

  5. Tokay gecko photoreceptors achieve rod-like physiology with cone-like proteins.

    Science.gov (United States)

    Zhang, Xue; Wensel, Theodore G; Yuan, Ching

    2006-01-01

    The retinal photoreceptors of the nocturnal Tokay gecko (Gekko gekko) consist exclusively of rods by the criteria of morphology and key features of their light responses. Unlike cones, they display robust photoresponses and have relatively slow recovery times. Nonetheless, the major and minor visual pigments identified in gecko rods are of the cone type by sequence and spectroscopic behavior. In the ongoing search for the molecular bases for the physiological differences between cones and rods, we have characterized the molecular biology and biochemistry of the gecko rod phototransduction cascade. We have cloned cDNAs encoding all or part of major protein components of the phototransduction cascade by RT-PCR with degenerate oligonucleotides designed to amplify cone- or rod-like sequences. For all proteins examined we obtained only cone-like and never rod-like sequences. The proteins identified include transducin alpha (Galphat), phosphodiesterase (PDE6) catalytic and inhibitory subunits, cyclic nucleotide-gated channel (CNGalpha) and arrestin. We also cloned cDNA encoding gecko RGS9-1 (Regulator of G Protein Signaling 9, splice variant 1), which is expressed in both rods and cones of all species studied but is typically found at 10-fold higher concentrations in cones, and found that gecko rods contain slightly lower RGS9-1 levels than mammalian rods. Furthermore, we found that the levels of GTPase accelerating protein (GAP) activity and cyclic GMP (cGMP) phosphodiesterase activity were similar in gecko and mammalian rods. These results place substantial constraints on the critical changes needed to convert a cone into a rod in the course of evolution: The many features of phototransduction molecules conserved between those expressed in gecko rods and those expressed in cones cannot explain the physiological differences, whereas the higher levels of RGS9-1 and GAP activity in cones are likely among the essential requirements for the rapid photoresponses of cones.

  6. Technical factors influencing cone packing density estimates in adaptive optics flood illuminated retinal images.

    Directory of Open Access Journals (Sweden)

    Marco Lombardo

    Full Text Available PURPOSE: To investigate the influence of various technical factors on the variation of cone packing density estimates in adaptive optics flood illuminated retinal images. METHODS: Adaptive optics images of the photoreceptor mosaic were obtained in fifteen healthy subjects. The cone density and Voronoi diagrams were assessed in sampling windows of 320×320 µm, 160×160 µm and 64×64 µm at 1.5 degree temporal and superior eccentricity from the preferred locus of fixation (PRL. The technical factors that have been analyzed included the sampling window size, the corrected retinal magnification factor (RMFcorr, the conversion from radial to linear distance from the PRL, the displacement between the PRL and foveal center and the manual checking of cone identification algorithm. Bland-Altman analysis was used to assess the agreement between cone density estimated within the different sampling window conditions. RESULTS: The cone density declined with decreasing sampling area and data between areas of different size showed low agreement. A high agreement was found between sampling areas of the same size when comparing density calculated with or without using individual RMFcorr. The agreement between cone density measured at radial and linear distances from the PRL and between data referred to the PRL or the foveal center was moderate. The percentage of Voronoi tiles with hexagonal packing arrangement was comparable between sampling areas of different size. The boundary effect, presence of any retinal vessels, and the manual selection of cones missed by the automated identification algorithm were identified as the factors influencing variation of cone packing arrangements in Voronoi diagrams. CONCLUSIONS: The sampling window size is the main technical factor that influences variation of cone density. Clear identification of each cone in the image and the use of a large buffer zone are necessary to minimize factors influencing variation of Voronoi

  7. Application of a Pattern-based Classification System for Invasive Endocervical Adenocarcinoma in Cervical Biopsy, Cone and Loop Electrosurgical Excision (LEEP) Material: Pattern on Cone and LEEP is Predictive of Pattern in the Overall Tumor.

    Science.gov (United States)

    Djordjevic, Bojana; Parra-Herran, Carlos

    2016-09-01

    A pattern-based classification system has been recently proposed for invasive endocervical adenocarcinoma, which is predictive of the risk of nodal metastases. Identifying cases at risk of nodal involvement is most relevant at the time of biopsy and loop electrosurgical excision procedure (LEEP) to allow for optimal surgical planning, and, most importantly, consideration of lymphadenectomy. This study aims to determine the topography of patterns of stromal invasion in invasive endocervical adenocarcinoma with emphasis on patterns in biopsy, cone, and LEEP. Invasive pattern was assessed following the pattern-based classification (Patterns A, B, and C) in 47 invasive endocervical adenocarcinomas treated with hysterectomy or trachelectomy and correlated with pattern of invasion at the tumor surface (2 mm of tumor depth) and on preoperative biopsy and cone/LEEP. Patterns A, B, and C were present in 21.3%, 36.2%, and 42.5% of cases, respectively. Most pattern A cases were Stage IA (90%), whereas most Pattern B and C cases were Stage IB (76.5% and 80%, respectively). Horizontal spread was on average larger in Pattern C (24.1 mm) than in Patterns A and B (7.7 and 12.3 mm, respectively). Pattern at the tumor surface correlated with the overall pattern in 95.7% of cases. Concordance between patterns at cone/LEEP and hysterectomy was 92.8%; the only discrepant case was upgraded from Pattern A on LEEP to C on final excision. Agreement between patterns in biopsy and the overall tumor, however, was only 37.5%. In all discrepant cases, biopsy failed to reveal destructive invasion, which was evident on excision. All discrepant biopsies with pattern A showed glandular complexity resembling exophytic papillary growth but did not meet criteria for destructive invasion. On excision, marked gland confluence with papillary architecture was evident. We conclude that the pattern of invasion on cone/LEEP is a good predictor of pattern of invasion on hysterectomy, particularly if there is

  8. gdf6a is required for cone photoreceptor subtype differentiation and for the actions of tbx2b in determining rod versus cone photoreceptor fate.

    Directory of Open Access Journals (Sweden)

    Michèle G Duval

    Full Text Available Functional vision restoration is within reach via stem cell therapy, but one of the largest obstacles is the derivation of colour-sensitive cone photoreceptors that are required for high-acuity daytime vision. To enhance progress made using nocturnal murine models, we instead utilize cone-rich zebrafish and herein investigate relationships between gdf6a and tbx2b in cone photoreceptor development. Growth/differentiation factor 6a (gdf6a, a bone morphogenetic protein family ligand, is an emerging factor in photoreceptor degenerative diseases. The T-box transcription factor tbx2b is required to specify UV cone photoreceptor fate instead of rod photoreceptor fate. Interactions between these factors in cone development would be unanticipated, considering the discrete phenotypes in their respective mutants. However, gdf6a positively modulates the abundance of tbx2b transcript during early eye morphogenesis, and we extended this conclusion to later stages of retinal development comprising the times when photoreceptors differentiate. Despite this, gdf6a-/- larvae possess a normal relative number of UV cones and instead present with a low abundance of blue cone photoreceptors, approximately half that of siblings (p<0.001, supporting a differential role for gdf6a amongst the spectral subtypes of cone photoreceptors. Further, gdf6a-/- larvae from breeding of compound heterozygous gdf6a+/-;tbx2b+/- mutants exhibit the recessive lots-of-rods phenotype (which also shows a paucity of UV cones at significantly elevated rates (44% or 48% for each of two tbx2b alleles, χ2 p≤0.007 for each compared to expected Mendelian 25%. Thus the gdf6a-/- background sensitizes fish such that the recessive lots-of-rods phenotype can appear in heterozygous tbx2b+/- fish. Overall, this work establishes a novel link between tbx2b and gdf6a in determining photoreceptor fates, defining the nexus of an intricate pathway influencing the abundance of cone spectral subtypes and

  9. A note about retinal structure and visual acuity. A light microscopic study of the cones in fovea centralis

    DEFF Research Database (Denmark)

    Rostgaard, Jørgen; Qvortrup, Klaus

    1999-01-01

    Primate eye, retina, fovea centralis, cone cells, non-shrinkage methods, light microscopy, resolution......Primate eye, retina, fovea centralis, cone cells, non-shrinkage methods, light microscopy, resolution...

  10. Effect of moisture content and dry unit weight on the resilient modulus of subgrade soils predicted by cone penetration test.

    Science.gov (United States)

    2002-06-01

    The objective of this study was to investigate the effect of moisture content and dry unit weight on the resilient characteristics of subgrade soil predicted by the cone penetration test. An experimental program was conducted in which cone penetratio...

  11. Local joint-limits using distance field cones in euler angle space

    DEFF Research Database (Denmark)

    Engell-Nørregård, Morten Pol; Abel, Sarah Maria Niebe; Erleben, Kenny

    Joint–limits are often modeled too simple, causing redundancy and allowing unnatural poses. We model the boundary of the feasible region, using a geometric approach. We show how to generate fast, general joint–limit cones for kinematic figures using signed distance fields. The distance–cone joint...

  12. Pheromones in White Pine Cone Beetle, Conophthorus coniperdu (Schwarz) (Coleoptera: Scolytidae)

    Science.gov (United States)

    Goran Birgersson; Gary L. DeBarr; Peter de Groot; Mark J. Dalusky; Harold D. Pierce; John H. Borden; Holger Meyer; Wittko Francke; Karl E. Espelie; C. Wayne Berisford

    1995-01-01

    Female white pine cone beetles, Conophrhorus coniperda, attacking second-year cones of eastern white pine, Pinus strobus L., produced a sex-specific pheromone that attracted conspecific males in laboratory bioassays and to field traps. Beetle response was enhanced by host monoterpenes. The female-produced compound was identified in...

  13. Some Equivalences between Cone b-Metric Spaces and b-Metric Spaces

    Directory of Open Access Journals (Sweden)

    Poom Kumam

    2013-01-01

    Full Text Available We introduce a b-metric on the cone b-metric space and then prove some equivalences between them. As applications, we show that fixed point theorems on cone b-metric spaces can be obtained from fixed point theorems on b-metric spaces.

  14. Ablation and cone formation mechanism on CR-39 by ArF laser irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Shakeri Jooybari, B., E-mail: baninshakery@gmail.com, E-mail: hafarideh@aut.ac.ir [Department of Energy Engineering and Physics, Amirkabir University of Technology, P.O. Box 15875-4413, Tehran, Islamic Republic of Iran (Iran, Islamic Republic of); Nuclear Science and Technology Research Institute NSRT, Tehran (Iran, Islamic Republic of); Afarideh, H., E-mail: baninshakery@gmail.com, E-mail: hafarideh@aut.ac.ir [Department of Energy Engineering and Physics, Amirkabir University of Technology, P.O. Box 15875-4413, Tehran, Islamic Republic of Iran (Iran, Islamic Republic of); Lamehi-Rachti, M. [Nuclear Science and Technology Research Institute NSRT, Tehran (Iran, Islamic Republic of); Ghergherehchi, M. [Department of Energy Engineering and Physics, Amirkabir University of Technology, P.O. Box 15875-4413, Tehran, Islamic Republic of Iran (Iran, Islamic Republic of); College of Information and Communication Engineering, Sungkyunkwan University, Suwon (Korea, Republic of)

    2015-03-07

    In this work, chemical properties, surface modification, and micro structures formation on ablated polyallyl di-glycol carbonate (CR-39) polymer by ArF laser irradiation (λ = 193 nm) at various fluences and pulse number were investigated. CR-39 samples have been irradiated with an ArF laser (193 nm) at a repetition rate of 1 Hz. Threshold fluence of ablation and effective absorption coefficient of CR-39 were determined. Conical microstructures (Taylor cone) formed on laser-ablated CR-39 exhibit: smooth, Taylor cone shape walls and sharp tips together with interference and well defined fringe-structure with a period of 230 nm, around cone base. Mechanism of cone formation and cone evolution of CR-39 ablated surface were investigated by change of fluences (at a given pulse number) and pulse number (at a given fluence). Cone height, cone base, and region of interface were increased in micrometer steps by increasing the total fluence. Depression on the base of the cone and the circular fringe were simulated. FTIR spectra were measured and energy dispersive x-ray analysis of irradiated and un-irradiated samples was performed.

  15. Fixed point results in cone metric spaces endowed with a graph

    Directory of Open Access Journals (Sweden)

    Kamal Fallahi

    2017-04-01

    Full Text Available In this paper, we prove the existence of fixed point for Chatterjea type mappings under $c$-distance in cone metric spaces endowed with a graph. The main results extend, generalized and unified some fixed point theorems on $c$-distance in metric and cone metric spaces.

  16. Scoria cones on Mars: detailed investigation of morphometry based on high - resolution Digital Elevation Models

    Czech Academy of Sciences Publication Activity Database

    Brož, Petr; Čadek, O.; Hauber, E.; Rossi, A. P.

    2015-01-01

    Roč. 120, č. 9 (2015), s. 1512-1527 ISSN 2169-9097 Institutional support: RVO:67985530 Keywords : Mars surface * volcanism * pyroclastic cone * scoria cone Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 3.440, year: 2013

  17. A simplified approach for the generation of projection data for cone ...

    Indian Academy of Sciences (India)

    has been calculated to compare the image quality. Keywords. Data generation; cone beam geometry; computed tomography; emission tomography. ... Generation of projection data for cone mean geometry. O. S. Y. X η r. µ ij η. (i, j). Figure 2. A ray emanating from the source S is subsequently attenuated on passing through ...

  18. Accumulation of (3H)glycine by cone bipolar neurons in the cat retina

    International Nuclear Information System (INIS)

    Cohen, E.; Sterling, P.

    1986-01-01

    Cone bipolar neurons in the cat retina were studied in serial sections prepared as electron microscope autoradiograms following intravitreal injection of ( 3 H)glycine. The goal was to learn whether the cone bipolar types that accumulate glycine correspond to the types thought on other grounds to be inhibitory. About half of the cone bipolars in a given patch of retina showed specific accumulation of silver grains. The specificity of accumulation was similar to that shown by glycine-accumulating amacrines. All of the cone bipolars arborizing in sublamina b accumulated glycine but none of the cone bipolars arborizing in sublamina a did so. The types of cone bipolars accumulating glycine did not match the types thought to be inhibitory. Cone bipolar types CBb1 and CBb2 both form gap junctions with the glycine-accumulating AII amacrine, thus raising the possibility that glycine might accumulate in these cone bipolars by diffusion from the AII cell or vice versa. Thus it is logically impossible to tell which of these three cells contains a high-affinity uptake mechanism for glycine and consequently which of the three might actually use glycine as a neurotransmitter

  19. Blue cone monochromatism in a female due to skewed X-inactivation

    DEFF Research Database (Denmark)

    Frederiksen, Anja L; Duno, Morten; Welinder, Lotte Gjesing

    2014-01-01

    Blue cone monochromatism (BCM) is a rare cone dystrophy with recessive X-linked inheritance and therefore diagnosed in males whereas females are clinically unaffected. We present a female with clinically manifested BCM. The diagnosis was genetically verified with the identification of one single ...

  20. Analysis of New Aerodynamic Design of the Nose Cone Section Using CFD and SPH

    Directory of Open Access Journals (Sweden)

    Bogdan-Alexandru BELEGA

    2015-06-01

    Full Text Available A new nose cones concept that promises a gain in performance over existing conventional nose cones is discussed in this paper. It is shown that significant performance gains result from the adaptation of the exhaust flow to the ambient pressure. For this complex work, it was necessary to collect and study the various nose cone shapes and the equations describing them? The paper objective was to identify the types of nose cones with ejector channels and specific aerodynamic characteristics of different types of nose cones. The scope of this paper is to develop some prototype profiles with outstanding aerodynamic qualities and low cost for use in construction projects for missile increasing their range and effect on target. The motivation for such a work is caused by a lack of data on aerodynamics for profiles of some nose cones and especially improved aerodynamic qualities that can be used in designing missiles/ rockets. This design method consists of a geometry creation step in which a three-dimensional geometry is generated, a mathematical model presented and a simple flow analysis (FLUENT Simulation from SolidWorks2012 and ANSYS Simulation with SPH for fluid-structure interaction, step which predicts the air intake mass flow rate. Flow phenomena observed in numerical simulations during different nose cone operations are highlighted, critical design aspects and operation conditions are discussed, and performance characteristics of the selected nose cone are presented.

  1. Micro-cones on a liquid interface in high electric field: Ionization effects

    Science.gov (United States)

    Subbotin, Andrey V.; Semenov, Alexander N.

    2018-02-01

    We formulate and explore electrohydrodynamic equations for conductive liquids taking dissociation/recombination processes into account and discover a novel type of liquid cones which carry both surface and net bulk charge and can be formed on a liquid interface in an electric field. The bulk charge is generated by the corona discharge due to a high electric field at the cone apex. We establish correlation between the cone angle and physical parameters of the liquid on the one hand and the electric current passing through the cone on the other hand. It is shown that the current strongly increases when the cone angle tends to a critical value which is a function of the dielectric permittivity of the liquid. The cone stability with respect to axially symmetric perturbations is analyzed. It is shown that the cones with apex angles close to the critical angle are likely to be stable. The effect of the imposed flow on the cone apex stability is also discussed.

  2. Cerro Xalapaxco: An Unusual Tuff Cone with Multiple Explosion Craters, in Central Mexico (Puebla)

    Science.gov (United States)

    Abrams, M. J.; Siebe, C.

    1994-01-01

    The Xalapaxco tuff cone is located on the northeast flank of La Malinche stratovolcano in central Mexico. An unusually large number (10) of explosion craters, concentrated on the central and on the uphill side of the cone, expose alternating beds of stratified surge deposits and massive fall deposits.

  3. Direct numerical simulation of hypersonic boundary-layer flow on a flared cone

    Energy Technology Data Exchange (ETDEWEB)

    Pruett, C.D. [James Madison Univ., Harrisonburg, VA (United States). Dept. of Math. and Comput. Sci.; Chang Chau-Lyan [High Technology Corporation, Hampton, VA 23666 (United States)

    1998-03-01

    The forced transition of the boundary layer on an axisymmetric flared cone in Mach 6 flow is simulated by the method of spatial direct numerical simulation (DNS). The full effects of the flared afterbody are incorporated into the governing equations and boundary conditions; these effects include nonzero streamwise surface curvature, adverse streamwise pressure gradient, and decreasing boundary-layer edge Mach number. Transition is precipitated by periodic forcing at the computational inflow boundary with perturbations derived from parabolized stability equation (PSE) methodology and based, in part, on frequency spectra available from physical experiments. Significant qualitative differences are shown to exist between the present results and those obtained previously for a cone without afterbody flare. In both cases, the primary instability is of second-mode type; however, frequencies are much higher for the flared cone because of the decrease in boundary-layer thickness in the flared region. Moreover, Goertler modes, which are linearly stable for the straight cone, are unstable in regions of concave body flare. Reynolds stresses, which peak near the critical layer for the straight cone, exhibit peaks close to the wall for the flared cone. The cumulative effect appears to be that transition onset is shifted upstream for the flared cone. However, the length of the transition zone may possibly be greater because of the seemingly more gradual nature of the transition process on the flared cone. (orig.) With 20 figs., 28 refs.

  4. Variability of silver fir (Abies alba Mill. cones – variability structure of scale surface area

    Directory of Open Access Journals (Sweden)

    Aniszewska Monika

    2017-03-01

    Full Text Available This study was conducted on a batch of closed silver fir cones from Jawor Forest District and a mixture of scales from the seed extraction facility Grotniki. The scales were divided into three size classes corresponding to the bottom, middle and upper part of the cones and their area was measured with the Multi Scan Base v.18.03 software. Based on the sum of the inner and outer surface area of all scales, we then determined the total area of evaporation from the cones. In addition, the area of protruding scales was measured for differently sized scales from different parts of the cones. Previous studies have shown that the average outer surface of a closed cone, calculated as the sum of protruding scales, accounts for 10% of the outer surface of an open cone. Pictures of both scale surfaces with the internal seed bed and the external protrusions were taken using a scanning electron microscope. We noticed significant differences in dimension and shape of the channels and trichomes on the scale surface. On the inner side of the scales, we found a high diversity of trichomes of different lengths, whilst the outer side contained channels. Presumably, these characteristics affect the rate of water loss from the cones during desiccation and separation of the seed. In-depth knowledge on the evaporative surfaces of fir cones and scale structure will be helpful for optimizing the industrial processes of seed extraction.

  5. Partial Hamiltonian reduction of relativistic extended objects in light-cone gauge

    DEFF Research Database (Denmark)

    de Woul, Jonas; Hoppe, Jens; Lundholm, Douglas Björn Alexander

    2011-01-01

    The elimination of the non-transversal field in the standard light-cone formulation of higher-dimensional extended objects is formulated as a Hamiltonian reduction.......The elimination of the non-transversal field in the standard light-cone formulation of higher-dimensional extended objects is formulated as a Hamiltonian reduction....

  6. Range to cone length relations for light ions in CR-39

    International Nuclear Information System (INIS)

    Gil, L.R.; Marques, A.

    1988-01-01

    Curves ''range x cone lenght'' and ''diameter x cone lenght'' are calculated for tracks left by low energy light ions in CR-39. The calculations cover ions from helium to iron and are performed for 6.25 N NaOH at 70 0 C and a standard etching time but can be easily extended to other etching conditions. (author) [pt

  7. New records and new species of cones from deeper water off Fiji (Mollusca, Gastropoda, Conidae)

    NARCIS (Netherlands)

    Moolenbeek, R.G.; Röckel, D.; Bouchet, P.

    2008-01-01

    A little less than 100 species of cones are known in the literature from waters around the Fiji islands, all intertidal to subtidal. We report here on the species taken by recent offshore and deep-water benthic sampling expeditions. Samples were taken to depths of 1300 m, although cones were taken

  8. Clinical course of cone dystrophy caused by mutations in the RPGR gene

    NARCIS (Netherlands)

    Thiadens, Alberta A. H. J.; Soerjoesing, Gyan G.; Florijn, Ralph J.; Tjiam, A. G.; den Hollander, Anneke I.; van den Born, L. Ingeborgh; Riemslag, Frans C.; Bergen, Arthur A. B.; Klaver, Caroline C. W.

    2011-01-01

    Mutations in the RPGR gene predominantly cause rod photoreceptor disorders with a large variability in clinical course. In this report, we describe two families with mutations in this gene and cone involvement. We investigated an X-linked cone dystrophy family (1) with 25 affected males, 25 female

  9. Clinical course of cone dystrophy caused by mutations in the RPGR gene

    NARCIS (Netherlands)

    Thiadens, A.A.H.J.; Soerjoesing, G.G.; Florijn, R.J.; Tjiam, A.G.; Hollander, A.I. den; Born, L.I. van den; Riemslag, F.C.; Bergen, A.A.B.; Klaver, C.C.

    2011-01-01

    BACKGROUND: Mutations in the RPGR gene predominantly cause rod photoreceptor disorders with a large variability in clinical course. In this report, we describe two families with mutations in this gene and cone involvement. METHODS: We investigated an X-linked cone dystrophy family (1) with 25

  10. Clinical course of cone dystrophy caused by mutations in the RPGR gene

    NARCIS (Netherlands)

    A.A.H.J. Thiadens (Alberta); G.G. Soerjoesing (Gyan); R.J. Florijn; A.G. Tjiam; A.I. Hollander (Anneke); L.I. van den Born (Ingeborgh); F.C.C. Riemslag (Frans); A.A.B. Bergen (Arthur); C.C.W. Klaver (Caroline)

    2011-01-01

    textabstractBackground: Mutations in the RPGR gene predominantly cause rod photoreceptor disorders with a large variability in clinical course. In this report, we describe two families with mutations in this gene and cone involvement. Methods: We investigated an X-linked cone dystrophy family (1)

  11. Simulating human cones from mid-mesopic up to high-photopic luminances

    NARCIS (Netherlands)

    Hateren, J.H. van; Snippe, H.P.

    2007-01-01

    A computational model of human cones for intensities ranging from 1 td up to full bleaching levels is presented. The model conforms well with measurements made in primate horizontal cells, follows Weber's law at high intensities, and performs range compression consistent with what is known of cones

  12. Homozygosity Mapping Reveals PDE6C Mutations in Patients with Early-Onset Cone Photoreceptor Disorders

    NARCIS (Netherlands)

    A.A.H.J. Thiadens (Alberta); A.I. Hollander (Anneke); S. Roosing (Susanne); S.B. Nabuurs (Sander); R.C. Zekveld-Vroon (Renate); R.W.J. Collin (Rob); E. de Baere (Elfride); R.K. Koenekoop (Robert); M.J. Schooneveld (Mary); T.M. Strom (Tim); J.J.C. van Lith-Verhoeven (Janneke); A.J. Lotery (Andrew); N. van Moll-Ramirez (Norka); B.P. Leroy (Bart); L.I. van den Born (Ingeborgh); C. Hoyng (Carel); F.P.M. Cremers (Frans); C.C.W. Klaver (Caroline)

    2009-01-01

    textabstractCone photoreceptor disorders form a clinical spectrum of diseases that include progressive cone dystrophy (CD) and complete and incomplete achromatopsia (ACHM). The underlying disease mechanisms of autosomal recessive (ar)CD are largely unknown. Our aim was to identify causative genes

  13. Homozygosity mapping reveals PDE6C mutations in patients with early-onset cone photoreceptor disorders

    NARCIS (Netherlands)

    Thiadens, Alberta A. H. J.; den Hollander, Anneke I.; Roosing, Susanne; Nabuurs, Sander B.; Zekveld-Vroon, Renate C.; Collin, Rob W. J.; de Baere, Elfride; Koenekoop, Robert K.; van Schooneveld, Mary J.; Strom, Tim M.; van Lith-Verhoeven, Janneke J. C.; Lotery, Andrew J.; van Moll-Ramirez, Norka; Leroy, Bart P.; van den Born, L. Ingeborgh; Hoyng, Carel B.; Cremers, Frans P. M.; Klaver, Caroline C. W.

    2009-01-01

    Cone photoreceptor disorders form a clinical spectrum of diseases that include progressive cone dystrophy (CD) and complete and incomplete achromatopsia (ACHM). The underlying disease mechanisms of autosomal recessive (ar)CD are largely unknown. Our aim was to identify causative genes for these

  14. Worldsheet theory of light-cone gauge noncritical strings on higher genus Riemann surfaces

    OpenAIRE

    Ishibashi, Nobuyuki; Murakami, Koichi

    2016-01-01

    It is possible to formulate light-cone gauge string field theory in noncritical dimensions. Such a theory corresponds to conformal gauge worldsheet theory with nonstandard longitudinal part. We study the longitudinal part of the worldsheet theory on higher genus Riemann surfaces. The results in this paper shall be used to study the dimensional regularization of light-cone gauge string field theory.

  15. The stability of cones and pyramids on sputtered surfaces of copper

    International Nuclear Information System (INIS)

    Chadderton, L.T.

    1979-01-01

    Cones and pyramids are formed on surfaces during the sputtering process. The author shows that the death of cones requires neither ion wind perturbations nor the presence of defects, but lies in the more fundamental physics of the sputtering process. (G.T.H.)

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

    Science.gov (United States)

    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...

  17. CELLULAR BASIS FOR ROD-CONE INTERACTIONS IN THE OUTER RETINA

    Directory of Open Access Journals (Sweden)

    David Križaj

    2002-12-01

    Full Text Available Background. At least twice daily our retinas move between a light adapted, cone-dominated (photopic state and a dark-adapted, color-blind and highly light-sensitive roddominated (scotopic state. In between is a rather ill-defined transitional state called the mesopic state in which retinal circuits express both rod and cone signals. Consequently, in the mesopic state the retinal output to the brain contained in the firing patterns of the ganglion cells consists of information derived from both rod and cone signals. Morphology, physiology and psychophysics all contributed to an understanding that the two systems are not independent but interact extensively via both pooling and mutual inhibition. This review lays down a rationale for such rod-cone interactions in the vertebrate retinas. It suggests that the important functional roles of rod-cone interactions is in that they shorten the duration of the mesopic state. As a result, the retina is maintained in either in the (rod-dominated high sensitivity photon counting mode or in the second mode which emphasizes temporal transients and spatial resolution (the cone-dominated photopic state.Conclusions. Experimental evidence for pre- and postsynaptic mixing of rod and cone signals in the retina is shown together with the preeminent neuromodulatory role of both light and dopamine in controling inter-actions between rod and cone signals. Dopamine is shown to be both necessary and sufficient to mediate light adaptation in the retina.

  18. Determination of CME 3D parameters based on a new full ice-cream cone model

    Science.gov (United States)

    Na, Hyeonock; Moon, Yong-Jae

    2017-08-01

    In space weather forecast, it is important to determine three-dimensional properties of CMEs. Using 29 limb CMEs, we examine which cone type is close to a CME three-dimensional structure. We find that most CMEs have near full ice-cream cone structure which is a symmetrical circular cone combined with a hemisphere. We develop a full ice-cream cone model based on a new methodology that the full ice-cream cone consists of many flat cones with different heights and angular widths. By applying this model to 12 SOHO/LASCO halo CMEs, we find that 3D parameters from our method are similar to those from other stereoscopic methods (i.e., a triangulation method and a Graduated Cylindrical Shell model). In addition, we derive CME mean density (ρmean=Mtotal/Vcone) based on the full ice-cream cone structure. For several limb events, we determine CME mass by applying the Solarsoft procedure (e.g., cme_mass.pro) to SOHO/LASCO C3 images. CME volumes are estimated from the full ice-cream cone structure. From the power-law relationship between CME mean density and its height, we estimate CME mean densities at 20 solar radii (Rs). We will compare the CME densities at 20 Rs with their corresponding ICME densities.

  19. Avian ultraviolet/violet cones identified as probable magnetoreceptors.

    Directory of Open Access Journals (Sweden)

    Christine Niessner

    Full Text Available BACKGROUND: The Radical-Pair-Model postulates that the reception of magnetic compass directions in birds is based on spin-chemical reactions in specialized photopigments in the eye, with cryptochromes discussed as candidate molecules. But so far, the exact subcellular characterization of these molecules in the retina remained unknown. METHODOLOGY/PRINCIPAL FINDINGS: We here describe the localization of cryptochrome 1a (Cry1a in the retina of European robins, Erithacus rubecula, and domestic chickens, Gallus gallus, two species that have been shown to use the magnetic field for compass orientation. In both species, Cry1a is present exclusively in the ultraviolet/violet (UV/V cones that are distributed across the entire retina. Electron microscopy shows Cry1a in ordered bands along the membrane discs of the outer segment, and cell fractionation reveals Cry1a in the membrane fraction, suggesting the possibility that Cry1a is anchored along membranes. CONCLUSIONS/SIGNIFICANCE: We provide first structural evidence that Cry1a occurs within a sensory structure arranged in a way that fulfils essential requirements of the Radical-Pair-Model. Our findings, identifying the UV/V-cones as probable magnetoreceptors, support the assumption that Cry1a is indeed the receptor molecule mediating information on magnetic directions, and thus provide the Radical-Pair-Model with a profound histological background.

  20. Hollow-Cone Spray Modeling for Outwardly Opening Piezoelectric Injector

    KAUST Repository

    Sim, Jaeheon

    2016-01-04

    Linear instability sheet atomization (LISA) breakup model has been widely used for modeling hollow-cone spray. However, the model was originally developed for inwardlyopening pressure-swirl injectors by assuming toroidal ligament breakups. Therefore, LISA model is not suitable for simulating outwardly opening injectors having string-like structures at wide spray angles. Furthermore, the varying area and shape of the annular nozzle exit makes the modeling difficult. In this study, a new spray modeling was proposed for outwardly opening hollow-cone injector. The injection velocities are computed from the given mas flow rate and injection pressure regardless of ambiguous nozzle exit geometries. The modified Kelvin-Helmholtz and Rayleigh-Taylor (KH-RT) breakup model is used with adjusted initial Sauter mean diameter (SMD) for modeling breakup of string-like liquid film spray. Liquid spray injection was modeled using Lagrangian discrete parcel method within the framework of commercial CFD software CONVERGE, and the detailed model was implemented by user defined functions. It was found that the new model predicted the liquid penetration length and local SMD accurately for various fuels and chamber conditions.