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Sample records for mass properties testing

  1. NASA Dryden: Flight Loads Lab Capabilities and Mass Properties Testing

    NASA Technical Reports Server (NTRS)

    Wolfe, David Michael; Bakalyar, John A.

    2011-01-01

    This presentation covers the basic capabilities of the Dryden Flight Loads Lab. It also covers in detail the mass properties capabilities of the loads lab, focusing on the recent mass properties testing of the X-48B, and the recent tests of the Dynamic Inertia Measurement method (DIMM). Presentation focuses on the test methods and issues discovered during the mass properties testing of the X-48B leading to the requirement of new instrumentation on all conventional mass properties testing. Presentation also focuses on development of DIMM for replacement of conventional mass properties tests.

  2. Frequency Shift During Mass Properties Testing Using Compound Pendulum Method

    NASA Technical Reports Server (NTRS)

    Wolfe, David; Regan, Chris

    2012-01-01

    During mass properties testing on the X-48B Blended Wing Body aircraft (The Boeing Company, Chicago, Illinois) at the National Aeronautics and Space Administration Dryden Flight Research Center, Edwards, California, large inertia measurement errors were observed in results from compound pendulum swings when compared to analytical models. By comparing periods of oscillations as measured from an average over the test period versus the period of each oscillation, it was noticed that the frequency of oscillation was shifting significantly throughout the test. This phenomenon was only noticed during compound pendulum swings, and not during bifilar pendulum swings. The frequency shift was only visible upon extensive data analysis of the frequency for each oscillation, and did not appear in averaged frequency data over the test period. Multiple test articles, test techniques, and hardware setups were used in attempts to eliminate or identify the cause of the frequency shift. Plotting the frequency of oscillation revealed a region of minimal shift that corresponded to a larger amplitude range. This region of minimal shift provided the most accurate results compared to a known test article; however, the amplitudes that produce accurate inertia measurements are amplitudes larger than those generally accepted in mass properties testing. This paper examines two case studies of the frequency shift, using mass properties testing performed on a dummy test article, and on the X-48B Blended Wing Body aircraft.

  3. Mass properties calibration of the NASA Langley low frequency vibration test apparatus

    NASA Technical Reports Server (NTRS)

    Javeed, Mehzad; Russell, James W.

    1995-01-01

    This report presents a description and calibration results of the modified NASA Langley Low Frequency Vibration Test Apparatus. The description includes both the suspension system and the data acquisition system. The test apparatus consists of a 2 inch thick, 21 inch diameter aluminum plate that is suspended from an advanced suspension system using a 40 foot long cable system. The test apparatus employed three orthogonally aligned pairs of Sundstrand QA-700 servo accelerometers that can measure accelerations as low as 1 micro-g. The calibration involved deriving the mass and moments of inertia of the test platform from measured input forces and measured acceleration responses. The derived mass and moments were compared to test platform mass properties obtained initially from measurements with a special mass properties instrument. Results of the calibration tests showed that using the product of the test apparatus mass and the measured accelerations, the disturbance force at the center of gravity (CG) can be determined within 4 percent on all three axes. Similarly the disturbance moments about the X, Y, and Z axes can be determined within 5 percent by using the product of the measured moments of inertia and the angular accelerations about the X, Y, and Z axes.

  4. Apollo Soyuz Test Project Weights and Mass Properties Operational Management System

    NASA Technical Reports Server (NTRS)

    Collins, M. A., Jr.; Hischke, E. R.

    1975-01-01

    The Apollo Soyuz Test Project (ASTP) Weights and Mass Properties Operational Management System was established to assure a timely and authoritative method of acquiring, controlling, generating, and disseminating an official set of vehicle weights and mass properties data. This paper provides an overview of the system and its interaction with the various aspects of vehicle and component design, mission planning, hardware and software simulations and verification, and real-time mission support activities. The effect of vehicle configuration, design maturity, and consumables updates is discussed in the context of weight control.

  5. Apollo Soyuz Test Project Weights and Mass Properties Operational Management System

    NASA Technical Reports Server (NTRS)

    Collins, M. A., Jr.; Hischke, E. R.

    1975-01-01

    The Apollo Soyuz Test Project (ASTP) Weights and Mass Properties Operational Management System was established to assure a timely and authoritative method of acquiring, controlling, generating, and disseminating an official set of vehicle weights and mass properties data. This paper provides an overview of the system and its interaction with the various aspects of vehicle and component design, mission planning, hardware and software simulations and verification, and real-time mission support activities. The effect of vehicle configuration, design maturity, and consumables updates is discussed in the context of weight control.

  6. Mass Properties Testing and Evaluation for the Multi-Mission Radioisotope Thermoelectric Generator

    SciTech Connect

    Felicione, Frank S.

    2009-12-01

    Mass properties (MP) measurements were performed for the Multi-Mission Radioisotope Thermoelectric Generator (MMRTG), serial number (S/N) 0X730401, the power system designated for the Mars Science Laboratory (MSL) mission. Measurements were made using new mounting fixtures at the mass properties testing station in the Idaho National Laboratory (INL) Space and Security Power Systems Facility (SSPSF). The objective of making mass properties measurements was to determine the generator’s flight configured mass and center of mass or center of gravity (CG). Using an extremely accurate platform scale, the mass of the as-tested generator was determined to be 100.117 ± 0.007 lb. Weight accuracy was determined by checking the platform scale with calibrated weights immediately prior to weighing the MMRTG.a CG measurement accuracy was assessed by surrogate testing using an inert mass standard for which the CG could be readily determined analytically. Repeated testing using the mass standard enabled the basic measurement precision of the system to be quantified in terms of a physical confidence interval about the measured CG position. However, repetitious testing with the MMRTG itself was not performed in deference to the gamma and neutron radiation dose to operators and the damage potential to the flight unit from extra handling operations. Since the mass standard had been specially designed to have a total weight and CG location that closely matched the MMRTG, the uncertainties determined from its testing were assigned to the MMRTG as well. On this basis, and at the 99% confidence level, a statistical analysis found the direct, as-measured MMRTG-MSL CG to be located at 10.816 ± 0.0011 in. measured perpendicular from the plane of the lower surface of the generator’s mounting lugs (Z direction), and offset from the generator’s long axis centerline in the X and Y directions by 0.0968 ± 0.0040 in. and 0.0276 ± 0.0026 in., respectively. These uncertainties are based

  7. Apollo/Soyuz test project operational data book. Volume 2: ASTP mass properties data book

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Spacecraft mass properties data are provided for use in mission planning, trajectory documentation, mission simulations, and consumable loading. Spacecraft for use in determining locations of spacecraft components and the relationship to coordinate systems in the launch and docked configuration. Mass properties and consumable loading data for the ASTP mission are included along with consumables mass property data and mission independent consumable loading information for the CSM and DM.

  8. Orion Pad Abort 1 Crew Module Mass Properties Test Approach and Results

    NASA Technical Reports Server (NTRS)

    Herrera, Claudia; Harding, Adam

    2012-01-01

    The Flight Loads Laboratory at the Dryden Flight Research Center conducted tests to measure the inertia properties of the Orion Pad Abort 1 (PA-1) Crew Module (CM). These measurements were taken to validate analytical predictions of the inertia properties of the vehicle and assist in reducing uncertainty for derived aero performance coefficients to be calculated post-launch. The first test conducted was to determine the Ixx of the Crew Module. This test approach used a modified torsion pendulum test setup that allowed the suspended Crew Module to rotate about the x axis. The second test used a different approach to measure both the Iyy and Izz properties. This test used a Knife Edge fixture that allowed small rotation of the Crew Module about the y and z axes. Discussions of the techniques and equations used to accomplish each test are presented. Comparisons with the predicted values used for the final flight calculations are made. Problem areas, with explanations and recommendations where available, are addressed. Finally, an evaluation of the value and success of these techniques to measure the moments of inertia of the Crew Module is provided.

  9. Experimental Validation of the Dynamic Inertia Measurement Method to Find the Mass Properties of an Iron Bird Test Article

    NASA Technical Reports Server (NTRS)

    Chin, Alexander W.; Herrera, Claudia Y.; Spivey, Natalie D.; Fladung, William A.; Cloutier, David

    2015-01-01

    The mass properties of an aerospace vehicle are required by multiple disciplines in the analysis and prediction of flight behavior. Pendulum oscillation methods have been developed and employed for almost a century as a means to measure mass properties. However, these oscillation methods are costly, time consuming, and risky. The NASA Armstrong Flight Research Center has been investigating the Dynamic Inertia Measurement, or DIM method as a possible alternative to oscillation methods. The DIM method uses ground test techniques that are already applied to aerospace vehicles when conducting modal surveys. Ground vibration tests would require minimal additional instrumentation and time to apply the DIM method. The DIM method has been validated on smaller test articles, but has not yet been fully proven on large aerospace vehicles.

  10. Experimental Validation of the Dynamic Inertia Measurement Method to Find the Mass Properties of an Iron Bird Test Article

    NASA Technical Reports Server (NTRS)

    Chin, Alexander; Herrera, Claudia; Spivey, Natalie; Fladung, William; Cloutier, David

    2015-01-01

    This presentation describes the DIM method and how it measures the inertia properties of an object by analyzing the frequency response functions measured during a ground vibration test (GVT). The DIM method has been in development at the University of Cincinnati and has shown success on a variety of small scale test articles. The NASA AFRC version was modified for larger applications.

  11. Mass properties measurement system dynamics

    NASA Technical Reports Server (NTRS)

    Doty, Keith L.

    1993-01-01

    The MPMS mechanism possess two revolute degrees-of-freedom and allows the user to measure the mass, center of gravity, and the inertia tensor of an unknown mass. The dynamics of the Mass Properties Measurement System (MPMS) from the Lagrangian approach to illustrate the dependency of the motion on the unknown parameters.

  12. a Tool Development of Mass Properties Database of a Satellite

    NASA Astrophysics Data System (ADS)

    Moon, Hong-Youl; Kim, Gyu-Sun

    2003-12-01

    One of the mechanical system engineer's tasks of a satellite design and development is to make the control plan, keep track and estimate the characteristics of system mass properties. As the design phases are go, mass properties related activities also transit as like a data collection, system mass property estimation and measurement. Fidelity of mass properties database should be confirmed through measurement test. In this paper the control plan and estimation of system mass properties are explained by the actual data and experience of the development of satellite and the fidelity of mass properties database was confirmed through measurement test.

  13. ACTOMP - AUTOCAD TO MASS PROPERTIES

    NASA Technical Reports Server (NTRS)

    Jones, A.

    1994-01-01

    AutoCAD to Mass Properties was developed to facilitate quick mass properties calculations of structures having many simple elements in a complex configuration such as trusses or metal sheet containers. Calculating the mass properties of structures of this type can be a tedious and repetitive process, but ACTOMP helps automate the calculations. The structure can be modelled in AutoCAD or a compatible CAD system in a matter of minutes using the 3-Dimensional elements. This model provides all the geometric data necessary to make a mass properties calculation of the structure. ACTOMP reads the geometric data of a drawing from the Drawing Interchange File (DXF) used in AutoCAD. The geometric entities recognized by ACTOMP include POINTs, 3DLINEs, and 3DFACEs. ACTOMP requests mass, linear density, or area density of the elements for each layer, sums all the elements and calculates the total mass, center of mass (CM) and the mass moments of inertia (MOI). AutoCAD utilizes layers to define separate drawing planes. ACTOMP uses layers to differentiate between multiple types of similar elements. For example if a structure is made of various types of beams, modeled as 3DLINEs, each with a different linear density, the beams can be grouped by linear density and each group placed on a separate layer. The program will request the linear density of 3DLINEs for each new layer it finds as it processes the drawing information. The same is true with POINTs and 3DFACEs. By using layers this way a very complex model can be created. POINTs are used for point masses such as bolts, small machine parts, or small electronic boxes. 3DLINEs are used for beams, bars, rods, cables, and other similarly slender elements. 3DFACEs are used for planar elements. 3DFACEs may be created as 3 or 4 Point faces. Some examples of elements that might be modelled using 3DFACEs are plates, sheet metal, fabric, boxes, large diameter hollow cylinders and evenly distributed masses. ACTOMP was written in Microsoft

  14. Test masses for the G-POEM test of the weak equivalence principle

    NASA Astrophysics Data System (ADS)

    Reasenberg, Robert D.; Phillips, James D.; Popescu, Eugeniu M.

    2011-11-01

    We describe the design of the test masses that are used in the ‘ground-based principle of equivalence measurement’ test of the weak equivalence principle. The main features of the design are the incorporation of corner cubes and the use of mass removal and replacement to create pairs of test masses with different test substances. The corner cubes allow for the vertical separation of the test masses to be measured with picometer accuracy by SAO's unique tracking frequency laser gauge, while the mass removal and replacement operations are arranged so that the test masses incorporating different test substances have nominally identical gravitational properties.

  15. Error analysis of system mass properties

    NASA Technical Reports Server (NTRS)

    Brayshaw, J.

    1984-01-01

    An attempt is made to verify the margin of system mass properties over values that are sufficient for the support of such other critical system requirements as those of dynamic control. System nominal mass properties are designed on the basis of an imperfect understanding of the mass and location of constituent elements; the effect of such element errors is to introduce net errors into calculated system mass properties. The direct measurement of system mass properties is, however, impractical. Attention is given to these issues in the case of the Galileo spacecraft.

  16. Computing Mass Properties From AutoCAD

    NASA Technical Reports Server (NTRS)

    Jones, A.

    1990-01-01

    Mass properties of structures computed from data in drawings. AutoCAD to Mass Properties (ACTOMP) computer program developed to facilitate quick calculations of mass properties of structures containing many simple elements in such complex configurations as trusses or sheet-metal containers. Mathematically modeled in AutoCAD or compatible computer-aided design (CAD) system in minutes by use of three-dimensional elements. Written in Microsoft Quick-Basic (Version 2.0).

  17. Innovative mechanism for measuring the mass properties of an object

    NASA Technical Reports Server (NTRS)

    Wolcott, Kedron R.; Graham, Todd A.; Doty, Keith L.

    1994-01-01

    The Kennedy Space Center Robotics Group recently completed development and testing on a novel approach to measure the mass properties of a rigid body. This unique design can measure the payload's weight, mass center location, and moments of inertia about three orthogonal axes. Furthermore, these measurements only require a single torque sensor and a single angular position sensor.

  18. Celotex Structural Properties Tests

    SciTech Connect

    Smith, A.C.

    2001-01-26

    In the course of regulatory review of the 9975 packaging, the question of the effects environmental conditions on performance of the packaging was raised. The results of previous tests of the Celotex material, used for impact absorption and thermal insulation, indicated that the effect of temperature variation was small. Accordingly, performance under ambient conditions was judged to be representative of performance under temperature extremes. To extend the database to include other effects, and in response to the questions, a series of materials tests were performed on the Celotex brand cellulose fiberboard material.

  19. NERVA mass properties computer methodology

    NASA Technical Reports Server (NTRS)

    Hall, I. K.

    1972-01-01

    The computer codes are presented that were used for the weight, center of gravity, and mass moment of inertia calculations and documentation for the NERVA. The two programs, E15301 and 12001B, are the basic tools used for weights work on the NERVA program. Used in conjunction with one another, they allow for rapid weights estimates for new concepts or changes while allowing for orderly documentation, which is a necessity in any effective weights effort. Program E15301 requires that each component be resolved into a collection of standard shapes. Separate subroutines then process geometric and material density data for each entry. The master program the performs all calculations necessary to combine these results into a total weight, center of gravity, and moment of inertia for the component. Program 12001B accepts previously calculated weight and center of gravity data for individual components. The program sums weights and calculates center of gravities and moments of inertia for systems of up to four levels of assemblies. The output identifies the engine parts in a format usable directly in a formal report.

  20. MASPROP- MASS PROPERTIES OF A RIGID STRUCTURE

    NASA Technical Reports Server (NTRS)

    Hull, R. A.

    1994-01-01

    The computer program MASPROP was developed to rapidly calculate the mass properties of complex rigid structural systems. This program's basic premise is that complex systems can be adequately described by a combination of basic elementary structural shapes. Thirteen widely used basic structural shapes are available in this program. They are as follows: Discrete Mass, Cylinder, Truncated Cone, Torus, Beam (arbitrary cross section), Circular Rod (arbitrary cross section), Spherical Segment, Sphere, Hemisphere, Parallelepiped, Swept Trapezoidal Panel, Symmetric Trapezoidal Panels, and a Curved Rectangular Panel. MASPROP provides a designer with a simple technique that requires minimal input to calculate the mass properties of a complex rigid structure and should be useful in any situation where one needs to calculate the center of gravity and moments of inertia of a complex structure. Rigid body analysis is used to calculate mass properties. Mass properties are calculated about component axes that have been rotated to be parallel to the system coordinate axes. Then the system center of gravity is calculated and the mass properties are transferred to axes through the system center of gravity by using the parallel axis theorem. System weight, moments of inertia about the system origin, and the products of inertia about the system center of mass are calculated and printed. From the information about the system center of mass the principal axes of the system and the moments of inertia about them are calculated and printed. The only input required is simple geometric data describing the size and location of each element and the respective material density or weight of each element. This program is written in FORTRAN for execution on a CDC 6000 series computer with a central memory requirement of approximately 62K (octal) of 60 bit words. The development of this program was completed in 1978.

  1. New Rotary Table Providing Improved Mass Property Measurements

    NASA Astrophysics Data System (ADS)

    Messing, R.; Appolloni, M.; Sablerolle, S.; Tavares, A.; Hervieu, M.

    2014-06-01

    ESA Test Centre at ESTEC, Noordwijk is a unique place in Europe, which is geared to perform environmental tests on large spacecraft at system level. The Test Centre includes the whole environmental facilities family: shakers, acoustic chamber, mass properties measurement facilities, electro-magnetic compatibility facilities and thermal vacuum chambers.Center of gravity (CoG) measurements require at least two force measurements in combination with a mass measurement to determine the CoG in the horizontal x-y plane. To achieve more quickly two or more orientations of the specimen with respect to the force cell the Test Centre implemented a rotary table on top of its W50/M6 mass property machine. This paper focuses on the acceptance and implementation of the rotary table and how by its use the CoG measurements could be improved in terms of measurement time, measurement uncertainty and measurement reliability.

  2. Testing Young Children's Ideas of Mass Measurement

    ERIC Educational Resources Information Center

    Cheeseman, Jill; McDonough, Andrea

    2013-01-01

    This article reports an innovative use of photographs in a pencil-and-paper test which was developed to assess young children's understanding of mass measurement. Two hundred and ninety-five tests were administered by thirteen teachers of Years 1 and 2 children in 3 urban and rural schools. Many of these children of 6-8 years of age were able to…

  3. Mass Property Measurements of the Mars Science Laboratory Rover

    NASA Technical Reports Server (NTRS)

    Fields, Keith

    2012-01-01

    The NASA/JPL Mars Science Laboratory (MSL) spacecraft mass properties were measured on a spin balance table prior to launch. This paper discusses the requirements and issues encountered with the setup, qualification, and testing using the spin balance table, and the idiosyncrasies encountered with the test system. The final mass measurements were made in the Payload Hazardous Servicing Facility (PHSF) at Kennedy Space Center on the fully assembled and fueled spacecraft. This set of environmental tests required that the control system for the spin balance machine be at a remote location, which posed additional challenges to the operation of the machine

  4. Mass Property Measurements of the Mars Science Laboratory Rover

    NASA Technical Reports Server (NTRS)

    Fields, Keith

    2012-01-01

    The NASA/JPL Mars Science Laboratory (MSL) spacecraft mass properties were measured on a spin balance table prior to launch. This paper discusses the requirements and issues encountered with the setup, qualification, and testing using the spin balance table, and the idiosyncrasies encountered with the test system. The final mass measurements were made in the Payload Hazardous Servicing Facility (PHSF) at Kennedy Space Center on the fully assembled and fueled spacecraft. This set of environmental tests required that the control system for the spin balance machine be at a remote location, which posed additional challenges to the operation of the machine

  5. E-Standards For Mass Properties Engineering

    NASA Technical Reports Server (NTRS)

    Cerro, Jeffrey A.

    2008-01-01

    A proposal is put forth to promote the concept of a Society of Allied Weight Engineers developed voluntary consensus standard for mass properties engineering. This standard would be an e-standard, and would encompass data, data manipulation, and reporting functionality. The standard would be implemented via an open-source SAWE distribution site with full SAWE member body access. Engineering societies and global standards initiatives are progressing toward modern engineering standards, which become functioning deliverable data sets. These data sets, if properly standardized, will integrate easily between supplier and customer enabling technically precise mass properties data exchange. The concepts of object-oriented programming support all of these requirements, and the use of a JavaTx based open-source development initiative is proposed. Results are reported for activity sponsored by the NASA Langley Research Center Innovation Institute to scope out requirements for developing a mass properties engineering e-standard. An initial software distribution is proposed. Upon completion, an open-source application programming interface will be available to SAWE members for the development of more specific programming requirements that are tailored to company and project requirements. A fully functioning application programming interface will permit code extension via company proprietary techniques, as well as through continued open-source initiatives.

  6. Mass variation tests for coating tablets and hard capsules: rational application of mass variation tests.

    PubMed

    Katori, Noriko; Aoyagi, Nobuo; Kojima, Shigeo

    2002-09-01

    The mass variation test is a simplified alternative test version of the content uniformity test. In the case of coating tablets and capsules, the mass variation test is principally applied to test the inner cores or fillings containing the active ingredient. However, some exceptions exist in pharmacopoeias. The effects of tablet coating and capsule shell on the results of the mass variation test were studied. The mass variation of outer crusts (coatings, capsule shells) and inner cores (core tablets, fillings) was measured separately in several products. The effects of coating on weight variability were very large for sugar-coated tablets. Relative standard deviation (RSD) of the formulation weight (RSD(W)) of sugar-coated tablets (2.73%) was larger than that of plain tablets (0.77%). The cause of the large RSD(W) is the large variation the weight of sugar-coating accounting for 44% of formulation weight. In the case of film-coated tablets, the effect of coating weight on the mass variation test was very small because the rate of coating in comparison to the whole weight was small. In the case of hard capsules, the usage of whole formulation weight resulted in underestimation of variations of filling weight. The differences between dosage forms in the applicability of the mass variation test are caused by differing weight proportions and variability of the outer coatings or shells. To avoid the underestimation of mass variation for hard capsules, a corrected acceptance value is useful. For all the dosage units, the mass variation test can principally be applied to determine which mass is expected to be proportional to the content of the active ingredient. However, some modification of acceptance values enables application of the mass variation tests to inapplicable cases, such as when the RSD of drug concentration (RSD(C)) is larger than 2%.

  7. Fundamental Properties of Low-Mass Stars and Brown Dwarfs

    SciTech Connect

    Liu, Michael C.; Dupuy, Trent J.; Stassun, Keivan G.; Allard, France; Blake, Cullen H.; Bonnefoy, M.; Cody, Ann Marie; Kraus, Adam; Day-Jones, A. C.; Lopez-Morales, Mercedes

    2009-02-16

    Precise measurements of the fundamental properties of low-mass stars and brown dwarfs are key to understanding the physics underlying their formation and evolution. While there has been great progress over the last decade in studying the bulk spectrophotometric properties of low-mass objects, direct determination of their masses, radii, and temperatures have been very sparse. Thus, theoretical predictions of low-mass evolution and ultracool atmospheres remain to be rigorously tested. The situation is alarming given that such models are widely used, from the determination of the low-mass end of the initial mass function to the characterization of exoplanets.An increasing number of mass, radius, and age determinations are placing critical constraints on the physics of low-mass objects. A wide variety of approaches are being pursued, including eclipsing binary studies, astrometric-spectroscopic orbital solutions, interferometry, and characterization of benchmark systems. In parallel, many more systems suitable for concerted study are now being found, thanks to new capabilities spanning both the very widest (all-sky surveys) and very narrowest (diffraction-limited adaptive optics) areas of the sky. This Cool Stars 15 splinter session highlighted the current successes and limitations of this rapidly growing area of precision astrophysics.

  8. Radiation pressure calibration and test mass reflectivities for LISA Pathfinder

    NASA Astrophysics Data System (ADS)

    Korsakova, Natalia; Kaune, Brigitte; LPF Collaboration

    2017-05-01

    This paper describes a series of experiments which were carried out during the main operations of LISA Pathfinder. These experiments were performed by modulating the power of the measurement and reference beams. In one series of experiments the beams were sequentially switched on and off. In the other series of experiments the powers of the beams were modulated within 0.1% and 1% of the constant power. These experiments use recordings of the total power measured on the photodiodes to infer the properties of the Optical Metrology System (OMS), such as reflectivities of the test masses and change of the photodiode efficiencies with time. In the first case the powers are back propagated from the different photodiodes to the same place on the optical bench to express the unknown quantities in the measurement with the complimentary photodiode measurements. They are combined in the way that the only unknown left is the test mass reflectivities. The second experiment compared two estimates of the force applied to the test masses due to the radiation pressure that appears because of the beam modulations. One estimate of the force is inferred from the measurements of the powers on the photodiodes and propagation of this measurement to the test masses. The other estimation of the force is done by calculating it from the change in the main scientific output of the instrument - differential displacement of the two test masses.

  9. AGN Host Galaxy Properties And Mass Function

    NASA Astrophysics Data System (ADS)

    Bongiorno, Angela

    2016-10-01

    Supermassive black hole growth, nuclear activity, and galaxy evolution have been found to be closely related. In the context of AGN-galaxy coevolution, I will discuss about the relation found between the host galaxy properties and the central BH and I will present the latest determination of the host galaxy stellar mass function (HGMF), and the specific accretion rate distribution function (SARDF), derived from the XMM-COSMOS sample up to z˜2.5, with particular focus on AGN feedback as possible responsible mechanism for galaxy quenching.

  10. Variability in properties of Salado Mass Concrete

    SciTech Connect

    Wakeley, L.D.; Harrington, P.T.; Hansen, F.D.

    1995-08-01

    Salado Mass Concrete (SMC) has been developed for use as a seal component in the Waste Isolation Pilot Plant. This concrete is intended to be mixed from pre-bagged materials, have an initial slump of 10 in., and remain pumpable and placeable for two hours after mixing. It is a mass concrete because it will be placed in monoliths large enough that the heat generated during cement hydration has the potential to cause thermal expansion and subsequent cracking, a phenomenon to avoid in the seal system. This report describes effects on concrete properties of changes in ratio of water to cement, batch size, and variations in characteristics of different lots of individual components of the concrete. The research demonstrates that the concrete can be prepared from laboratory-batched or pre-bagged dry materials in batches from 1.5 ft{sup 3} to 5.0 yd{sup 3}, with no chemical admixtures other than the sodium chloride added to improve bonding with the host rock, at a water-to-cement ratio ranging from 0.36 to 0.42. All batches prepared according to established procedures had adequate workability for at least 1.5 hours, and achieved or exceeded the target compressive strength of 4500 psi at 180 days after casting. Portland cement and fly ash from different lots or sources did not have a measurable effect on concrete properties, but variations in a shrinkage-compensating cement used as a component of the concrete did appear to affect workability. A low initial temperature and the water-reducing and set-retarding functions of the salt are critical to meeting target properties.

  11. The mass storage testing laboratory at GSFC

    NASA Technical Reports Server (NTRS)

    Venkataraman, Ravi; Williams, Joel; Michaud, David; Gu, Heng; Kalluri, Atri; Hariharan, P. C.; Kobler, Ben; Behnke, Jeanne; Peavey, Bernard

    1998-01-01

    Industry-wide benchmarks exist for measuring the performance of processors (SPECmarks), and of database systems (Transaction Processing Council). Despite storage having become the dominant item in computing and IT (Information Technology) budgets, no such common benchmark is available in the mass storage field. Vendors and consultants provide services and tools for capacity planning and sizing, but these do not account for the complete set of metrics needed in today's archives. The availability of automated tape libraries, high-capacity RAID systems, and high- bandwidth interconnectivity between processor and peripherals has led to demands for services which traditional file systems cannot provide. File Storage and Management Systems (FSMS), which began to be marketed in the late 80's, have helped to some extent with large tape libraries, but their use has introduced additional parameters affecting performance. The aim of the Mass Storage Test Laboratory (MSTL) at Goddard Space Flight Center is to develop a test suite that includes not only a comprehensive check list to document a mass storage environment but also benchmark code. Benchmark code is being tested which will provide measurements for both baseline systems, i.e. applications interacting with peripherals through the operating system services, and for combinations involving an FSMS. The benchmarks are written in C, and are easily portable. They are initially being aimed at the UNIX Open Systems world. Measurements are being made using a Sun Ultra 170 Sparc with 256MB memory running Solaris 2.5.1 with the following configuration: 4mm tape stacker on SCSI 2 Fast/Wide; 4GB disk device on SCSI 2 Fast/Wide; and Sony Petaserve on Fast/Wide differential SCSI 2.

  12. The mass storage testing laboratory at GSFC

    NASA Technical Reports Server (NTRS)

    Venkataraman, Ravi; Williams, Joel; Michaud, David; Gu, Heng; Kalluri, Atri; Hariharan, P. C.; Kobler, Ben; Behnke, Jeanne; Peavey, Bernard

    1998-01-01

    Industry-wide benchmarks exist for measuring the performance of processors (SPECmarks), and of database systems (Transaction Processing Council). Despite storage having become the dominant item in computing and IT (Information Technology) budgets, no such common benchmark is available in the mass storage field. Vendors and consultants provide services and tools for capacity planning and sizing, but these do not account for the complete set of metrics needed in today's archives. The availability of automated tape libraries, high-capacity RAID systems, and high- bandwidth interconnectivity between processor and peripherals has led to demands for services which traditional file systems cannot provide. File Storage and Management Systems (FSMS), which began to be marketed in the late 80's, have helped to some extent with large tape libraries, but their use has introduced additional parameters affecting performance. The aim of the Mass Storage Test Laboratory (MSTL) at Goddard Space Flight Center is to develop a test suite that includes not only a comprehensive check list to document a mass storage environment but also benchmark code. Benchmark code is being tested which will provide measurements for both baseline systems, i.e. applications interacting with peripherals through the operating system services, and for combinations involving an FSMS. The benchmarks are written in C, and are easily portable. They are initially being aimed at the UNIX Open Systems world. Measurements are being made using a Sun Ultra 170 Sparc with 256MB memory running Solaris 2.5.1 with the following configuration: 4mm tape stacker on SCSI 2 Fast/Wide; 4GB disk device on SCSI 2 Fast/Wide; and Sony Petaserve on Fast/Wide differential SCSI 2.

  13. Mass Properties for Space Systems Standards Development

    NASA Technical Reports Server (NTRS)

    Beech, Geoffrey

    2013-01-01

    Current Verbiage in S-120 Applies to Dry Mass. Mass Margin is difference between Required Mass and Predicted Mass. Performance Margin is difference between Predicted Performance and Required Performance. Performance estimates and corresponding margin should be based on Predicted Mass (and other inputs). Contractor Mass Margin reserved from Performance Margin. Remaining performance margin allocated according to mass partials. Compliance can be evaluated effectively by comparison of three areas (preferably on a single sheet). Basic and Predicted Mass (including historical trend). Aggregate potential changes (threats and opportunities) which gives Mass Forecast. Mass Maturity by category (Estimated/Calculated/Actual).

  14. New Mass Properties Engineers Aerospace Ballasting Challenge Facilitated by the SAWE Community

    NASA Technical Reports Server (NTRS)

    Cutright, Amanda; Shaughnessy, Brendan

    2010-01-01

    The discipline of Mass Properties Engineering tends to find the engineers; not typically vice versa. In this case, two engineers quickly found their new responsibilities deep in many aspects of mass properties engineering and required to meet technical challenges in a fast paced environment. As part of NASA's Constellation Program, a series of flight tests will be conducted to evaluate components of the new spacecraft launch vehicles. One of these tests is the Pad Abort 1 (PA-1) flight test which will test the Launch Abort System (LAS), a system designed to provide escape for astronauts in the event of an emergency. The Flight Test Articles (FTA) used in this flight test are required to match mass properties corresponding to the operational vehicle, which has a continually evolving design. Additionally, since the structure and subsystems for the Orion Crew Module (CM) FTA are simplified versions of the final product, thousands of pounds of ballast are necessary to achieve the desired mass properties. These new mass properties engineers are responsible for many mass properties aspects in support of the flight test, including meeting the ballasting challenge for the CM Boilerplate FTA. SAWE expert and experienced mass properties engineers, both those that are directly on the team and many that supported via a variety of Society venues, significantly contributed to facilitating the success of addressing this particular mass properties ballasting challenge, in addition to many other challenges along the way. This paper discusses the details regarding the technical aspects of this particular mass properties challenge, as well as identifies recommendations for new mass properties engineers that were learned from the SAWE community along the way.

  15. Mass Properties Measurement in the X-38 Project

    NASA Technical Reports Server (NTRS)

    Peterson, Wayne L.

    2004-01-01

    This paper details the techniques used in measuring the mass properties for the X-38 family of test vehicles. The X-38 Project was a NASA internal venture in which a series of test vehicles were built in order to develop a Crew Return Vehicle (CRV) for the International Space Station. Three atmospheric test vehicles and one spaceflight vehicle were built to develop the technologies required for a CRV. The three atmospheric test vehicles have undergone flight-testing by a combined team from the NASA Johnson Space Center and the NASA Dryden Flight Research Center. The flight-testing was performed at Edward's Air Force Base in California. The X-38 test vehicles are based on the X-24A, which flew in the '60s and '70s. Scaled Composites, Inc. of Mojave, California, built the airframes and the vehicles were outfitted at the NASA Johnson Space Center in Houston, Texas. Mass properties measurements on the atmospheric test vehicles included weight and balance by the three-point suspension method, four-point suspension method, three load cells on jackstands, and on three in-ground platform scales. Inertia measurements were performed as well in which Ixx, Iyy, Izz, and Ixz were obtained. This paper describes each technique and the relative merits of each. The proposed measurement methods for an X-38 spaceflight test vehicle will also be discussed. This vehicle had different measurement challenges, but integrated vehicle measurements were never conducted. The spaceflight test vehicle was also developed by NASA and was scheduled to fly on the Space Shuttle before the project was cancelled.

  16. Testing galaxy formation models with galaxy stellar mass functions

    NASA Astrophysics Data System (ADS)

    Lim, S. H.; Mo, H. J.; Lan, T.-W.; Ménard, B.

    2017-01-01

    We compare predictions of a number of empirical models and numerical simulations of galaxy formation to the conditional stellar mass functions of galaxies in groups of different masses obtained recently by Lan et al. to test how well different models accommodate the data. The observational data clearly prefer a model in which star formation in low-mass haloes changes behaviour at a characteristic redshift zc ˜ 2. There is also tentative evidence that this characteristic redshift depends on environment, becoming zc ˜ 4 in regions that eventually evolve into rich clusters of galaxies. The constrained model is used to understand how galaxies form and evolve in dark matter haloes, and to make predictions for other statistical properties of the galaxy population, such as the stellar mass functions of galaxies at high z, the star formation, and stellar mass assembly histories in dark matter haloes. A comparison of our model predictions with those of other empirical models shows that different models can make vastly different predictions, even though all of them are tuned to match the observed stellar mass functions of galaxies.

  17. Survey and Experimental Testing of Nongravimetric Mass Measurement Devices

    NASA Technical Reports Server (NTRS)

    Oakey, W. E.; Lorenz, R.

    1977-01-01

    Documentation presented describes the design, testing, and evaluation of an accelerated gravimetric balance, a low mass air bearing oscillator of the spring-mass type, and a centrifugal device for liquid mass measurement. A direct mass readout method was developed to replace the oscillation period readout method which required manual calculations to determine mass. A protoype 25 gram capacity micro mass measurement device was developed and tested.

  18. High Precision Atomic Mass Measurements: Tests of CVC and IMME

    NASA Astrophysics Data System (ADS)

    Eronen, Tommi

    2011-11-01

    Atomic mass is one of the key ingredients in testing the Conserved Vector Current (CVC) hypothesis and Isobaric Mass Multiplet Equation (IMME). With JYFLTRAP Penning trap installation at the University of Jyväskylä, Finland, several atomic massses related to these studies have been measured. The performed atomic mass measurements for CVC tests cover almost all the nuclei that are relevant for these studies. To test IMME, masses in two isobaric mass chains (A = 23 and A = 32) have been determined.

  19. High Precision Atomic Mass Measurements: Tests of CVC and IMME

    SciTech Connect

    Eronen, Tommi; Collaboration: JYFLTRAP Collaboration

    2011-11-30

    Atomic mass is one of the key ingredients in testing the Conserved Vector Current (CVC) hypothesis and Isobaric Mass Multiplet Equation (IMME). With JYFLTRAP Penning trap installation at the University of Jyvaeskylae, Finland, several atomic massses related to these studies have been measured. The performed atomic mass measurements for CVC tests cover almost all the nuclei that are relevant for these studies. To test IMME, masses in two isobaric mass chains (A = 23 and A = 32) have been determined.

  20. Determination of HART I Blade Structural Properties by Laboratory Testing

    NASA Technical Reports Server (NTRS)

    Jung, Sung N.; Lau, Benton H.

    2012-01-01

    The structural properties of higher harmonic Aeroacoustic Rotor Test (HART I) blades were measured using the original set of blades tested in the German-dutch wind tunnel (DNW) in 1994. the measurements include bending and torsion stiffness, geometric offsets, and mass and inertia properties of the blade. the measured properties were compared to the estimated values obtained initially from the blade manufacturer. The previously estimated blade properties showed consistently higher stiffness, up to 30 percent for the flap bending in the blade inboard root section.

  1. Mass properties report on 156-inch diameter SRM

    NASA Technical Reports Server (NTRS)

    1972-01-01

    Mass properties data for 156-in.-dia SRM booster with two segments are presented. The SRM baseline booster has a fixed 15 degrees canted nozzle and no thrust neutralization system. Summary mass properties data for alternative booster configurations are included.

  2. MASSES, RADII, AND CLOUD PROPERTIES OF THE HR 8799 PLANETS

    SciTech Connect

    Marley, Mark S.; Saumon, Didier; Cushing, Michael; Ackerman, Andrew S.; Fortney, Jonathan J.; Freedman, Richard E-mail: dsaumon@lanl.gov E-mail: andrew.ackerman@nasa.gov E-mail: freedman@darkstar.arc.nasa.gov

    2012-08-01

    The near-infrared colors of the planets directly imaged around the A star HR 8799 are much redder than most field brown dwarfs of the same effective temperature. Previous theoretical studies of these objects have concluded that the atmospheres of planets b, c, and d are unusually cloudy or have unusual cloud properties. Some studies have also found that the inferred radii of some or all of the planets disagree with expectations of standard giant planet evolution models. Here, we compare the available data to the predictions of our own set of atmospheric and evolution models that have been extensively tested against observations of field L and T dwarfs, including the reddest L dwarfs. Unlike some previous studies, we require mutually consistent choices for effective temperature, gravity, cloud properties, and planetary radius. This procedure thus yields plausible values for the masses, effective temperatures, and cloud properties of all three planets. We find that the cloud properties of the HR 8799 planets are not unusual but rather follow previously recognized trends, including a gravity dependence on the temperature of the L to T spectral transition-some reasons for which we discuss. We find that the inferred mass of planet b is highly sensitive to whether or not we include the H- and the K-band spectrum in our analysis. Solutions for planets c and d are consistent with the generally accepted constraints on the age of the primary star and orbital dynamics. We also confirm that, like in L and T dwarfs and solar system giant planets, non-equilibrium chemistry driven by atmospheric mixing is also important for these objects. Given the preponderance of data suggesting that the L to T spectral type transition is gravity dependent, we present an exploratory evolution calculation that accounts for this effect. Finally we recompute the bolometric luminosity of all three planets.

  3. Mass properties survey of solar array technologies

    NASA Technical Reports Server (NTRS)

    Kraus, Robert

    1991-01-01

    An overview of the technologies, electrical performance, and mass characteristics of many of the presently available and the more advanced developmental space solar array technologies is presented. Qualitative trends and quantitative mass estimates as total array output power is increased from 1 kW to 5 kW at End of Life (EOL) from a single wing are shown. The array technologies are part of a database supporting an ongoing solar power subsystem model development for top level subsystem and technology analyses. The model is used to estimate the overall electrical and thermal performance of the complete subsystem, and then calculate the mass and volume of the array, batteries, power management, and thermal control elements as an initial sizing. The array types considered here include planar rigid panel designs, flexible and rigid fold-out planar arrays, and two concentrator designs, one with one critical axis and the other with two critical axes. Solar cell technologies of Si, GaAs, and InP were included in the analyses. Comparisons were made at the array level; hinges, booms, harnesses, support structures, power transfer, and launch retention mountings were included. It is important to note that the results presented are approximations, and in some cases revised or modified performance and mass estimates of specific designs.

  4. Observational Properties of Coronal Mass Ejections

    DTIC Science & Technology

    2006-01-01

    disconnection leads to interplan- etary magnetic fields completely unattached to the corona , for which solar wind signatures are rarely, if ever, seen...the properties over the solar cycle. The corona - active region, Astrophys. J., 575, 1116, 2002. graph observations have been supplemented with ground...Approved for Public Release; Distribution Unlimited. 13. SUPPLEMENTARY NOTES REPRINTED FROM: SOLAR ERUPTIONS AND ENERGETIC PARTICLES, Geophysical Monograph

  5. IMP: Interactive mass properties program. Volume 1: Program description

    NASA Technical Reports Server (NTRS)

    Stewart, W. A.

    1976-01-01

    A method of computing a weights and center of gravity analysis of a flight vehicle using interactive graphical capabilities of the Adage 340 computer is described. The equations used to calculate area, volume, and mass properties are based on elemental surface characteristics. The input/output methods employ the graphic support of the Adage computer. Several interactive program options are available for analyzing the mass properties of a vehicle. These options are explained.

  6. Mass properties measurement system: Dynamics and statics measurements

    NASA Technical Reports Server (NTRS)

    Doty, Keith L.

    1993-01-01

    This report presents and interprets experimental data obtained from the Mass Properties Measurement System (MPMS). Statics measurements yield the center-of-gravity of an unknown mass and dynamics measurements yield its inertia matrix. Observations of the MPMS performance has lead us to specific design criteria and an understanding of MPMS limitations.

  7. Kinematical properties of coronal mass ejections

    NASA Astrophysics Data System (ADS)

    Temmer, M.

    2016-11-01

    Coronal mass ejections (CMEs) are the most dynamic phenomena in our solar system. They abruptly disrupt the continuous outflow of solar wind by expelling huge clouds of magnetized plasma into interplanetary space with velocities enabling to cross the Sun-Earth distance within a few days. Earth-directed CMEs may cause severe geomagnetic storms when their embedded magnetic fields and the shocks ahead compress and reconnect with the Earth's magnetic field. The transit times and impacts in detail depend on the initial CME velocity, size, and mass, as well as on the conditions and coupling processes with the ambient solar wind flow in interplanetary space. The observed CME parameters may be severely affected by projection effects and the constant changing environmental conditions are hard to derive. This makes it difficult to fully understand the physics behind CME evolution, preventing to do a reliable forecast of Earth-directed events. This short review focusing on observational data, shows recent methods which were developed to derive the CME kinematical profile for the entire Sun-Earth distance range as well as studies which were performed to shed light on the physical processes that CMEs encounter when propagating from Sun to Earth.

  8. Thermorefractive noise of finite-sized cylindrical test masses

    NASA Astrophysics Data System (ADS)

    Heinert, D.; Gurkovsky, A. G.; Nawrodt, R.; Vyatchanin, S. P.; Yamamoto, K.

    2011-09-01

    We present an analytical solution for the effect of thermorefractive noise considering finite-sized cylindrical test masses. For crystalline materials at low temperatures, the effect of finite dimensions becomes important. The calculations are independently performed using the Fluctuation-Dissipation-Theorem and Langevin’s approach. Our results are applied to the input test mass of the current and future cryogenic gravitational wave detectors CLIO, LCGT, and ET and are compared to the respective standard quantum limit. For a substrate temperature of 10 K, we find that the thermorefractive noise amplitude of the silicon input test mass in ET is only a factor of 2 below the standard quantum limit for frequencies above 500 Hz. Thus, thermorefractive noise of the input test mass could become a severe limitation if one uses techniques to beat the standard quantum limit like, e.g., squeezing. In contrast, the effect of thermorefractive noise of the input test mass is negligible for CLIO and LCGT.

  9. Inficon Transpector MPH Mass Spectrometer Random Vibration Test Report

    NASA Technical Reports Server (NTRS)

    Santiago-Bond, Jo; Captain, Janine

    2015-01-01

    The purpose of this test report is to summarize results from the vibration testing of the INFICON Transpector MPH100M model Mass Spectrometer. It also identifies requirements satisfied, and procedures used in the test. As a payload of Resource Prospector, it is necessary to determine the survivability of the mass spectrometer to proto-qualification level random vibration. Changes in sensitivity of the mass spectrometer can be interpreted as a change in alignment of the instrument. The results of this test will be used to determine any necessary design changes as the team moves forward with flight design.

  10. Geometrical Properties of Coronal Mass Ejections

    NASA Astrophysics Data System (ADS)

    Cremades, Hebe; Bothmer, Volker

    Based on the SOHO/LASCO dataset, a collection of "structured" coronal mass ejections (CMEs) has been compiled within the period 1996-2002, in order to analyze their three-dimensional configuration. These CME events exhibit white-light fine structures, likely indicative of their possible 3D topology. From a detailed investigation of the associated low coronal and photospheric source regions, a generic scheme has been deduced, which considers the white-light topology of a CME projected in the plane of the sky as being primarily dependent on the orientation and position of the source region's neutral line on the solar disk. The obtained results imply that structured CMEs are essentially organized along a symmetry axis, in a cylindrical manner. The measured dimensions of the cylinder's base and length yield a ratio of 1.6. These CMEs seem to be better approximated by elliptic cones, rather than by the classical ice cream cone, characterized by a circular cross section.

  11. Thermal modelling of Advanced LIGO test masses

    NASA Astrophysics Data System (ADS)

    Wang, H.; Blair, C.; Dovale Álvarez, M.; Brooks, A.; Kasprzack, M. F.; Ramette, J.; Meyers, P. M.; Kaufer, S.; O'Reilly, B.; Mow-Lowry, C. M.; Freise, A.

    2017-06-01

    High-reflectivity fused silica mirrors are at the epicentre of today’s advanced gravitational wave detectors. In these detectors, the mirrors interact with high power laser beams. As a result of finite absorption in the high reflectivity coatings the mirrors suffer from a variety of thermal effects that impact on the detectors’ performance. We propose a model of the Advanced LIGO mirrors that introduces an empirical term to account for the radiative heat transfer between the mirror and its surroundings. The mechanical mode frequency is used as a probe for the overall temperature of the mirror. The thermal transient after power build-up in the optical cavities is used to refine and test the model. The model provides a coating absorption estimate of 1.5-2.0 ppm and estimates that 0.3 to 1.3 ppm of the circulating light is scattered onto the ring heater.

  12. Masses, Radii, and Cloud Properties of the HR 8799 Planets

    NASA Technical Reports Server (NTRS)

    Marley, Mark S.; Saumon, Didier; Cushing, Michael; Ackerman, Andrew S.; Fortney, Jonathan J.; Freedman, Richard

    2012-01-01

    The near-infrared colors of the planets directly imaged around the A star HR 8799 are much redder than most field brown dwarfs of the same effective temperature. Previous theoretical studies of these objects have compared the photometric and limited spectral data of the planets to the predictions of various atmosphere and evolution models and concluded that the atmospheres of planets b, c, and d are unusually cloudy or have unusual cloud properties. Most studies have also found that the inferred radii of some or all of the planets disagree with expectations of standard giant planet evolution models. Here we compare the available data to the predictions of our own set of atmospheric and evolution models that have been extensively tested against field L and T dwarfs, including the reddest L dwarfs. Unlike almost all previous studies we specify mutually self-consistent choices for effective temperature, gravity, cloud properties, and planetary radius. This procedure yields plausible and self-consistent values for the masses, effective temperatures, and cloud properties of all three planets. We find that the cloud properties of the HR 8799 planets are in fact not unusual but rather follow previously recognized trends including a gravity dependence on the temperature of the L to T spectral transition, some reasons for which we discuss. We find that the inferred mass of planet b is highly sensitive to the H and K band spectrum. Solutions for planets c and particularly d are less certain but are consistent with the generally accepted constraints on the age of the primary star and orbital dynamics. We also confirm that as for L and T dwarfs and solar system giant planets, non-equilibrium chemistry driven by atmospheric mixing is also important for these objects. Given the preponderance of data suggesting that the L to T spectral type transition is gravity dependent, we present a new evolution calculation that predicts cooling tracks on the near-infrared color

  13. A Residual Mass Ballistic Testing Method to Compare Armor Materials or Components (Residual Mass Ballistic Testing Method)

    SciTech Connect

    Benjamin Langhorst; Thomas M Lillo; Henry S Chu

    2014-05-01

    A statistics based ballistic test method is presented for use when comparing multiple groups of test articles of unknown relative ballistic perforation resistance. The method is intended to be more efficient than many traditional methods for research and development testing. To establish the validity of the method, it is employed in this study to compare test groups of known relative ballistic performance. Multiple groups of test articles were perforated using consistent projectiles and impact conditions. Test groups were made of rolled homogeneous armor (RHA) plates and differed in thickness. After perforation, each residual projectile was captured behind the target and its mass was measured. The residual masses measured for each test group were analyzed to provide ballistic performance rankings with associated confidence levels. When compared to traditional V50 methods, the residual mass (RM) method was found to require fewer test events and be more tolerant of variations in impact conditions.

  14. Using Photographs and Diagrams to Test Young Children's Mass Thinking

    ERIC Educational Resources Information Center

    Cheeseman, Jill; McDonough, Andrea

    2013-01-01

    This paper reports the results of a pencil-and-paper test developed to assess young children's understanding of mass measurement. The innovative element of the test was its use of photographs. We found many children of the 295 6-8 year-old children tested could "read" the photographs and diagrams and recognise the images as…

  15. ENVIRONMENTAL DEPENDENCE OF OTHER GALAXY PROPERTIES FOR HIGH STELLAR MASS AND LOW STELLAR MASS GALAXIES

    SciTech Connect

    Deng Xinfa; Wen Xiaoqing; Xu Jianying; Ding Yingping; Huang Tong

    2010-06-10

    At a stellar mass of 3 x 10{sup 10} M {sub {Theta}} we divide the volume-limited Main galaxy sample of the Sloan Digital Sky Survey Data Release 6 (SDSS DR6) into two distinct families and explore the environmental dependence of galaxy properties for High Stellar Mass (HSM) and Low Stellar Mass (LSM) galaxies. It is found that for HSM and LSM galaxies, the environmental dependence of some typical galaxy properties, such as color, morphologies, and star formation activities, is still very strong, which at least shows that the stellar mass is not fundamental in correlations between galaxy properties and the environment. We also note that the environmental dependence of the size for HSM and LSM galaxies is fairly weak, which is mainly due to the galaxy size being insensitive to environment.

  16. Physical properties of erupting plasma associated with coronal mass ejections

    NASA Astrophysics Data System (ADS)

    Lee, J.; Raymond, J. C.; Reeves, K. K.; Moon, Y.; Kim, K.

    2013-12-01

    We investigate the physical properties (temperature, density, and mass) of erupting plasma observed in X-rays and EUV, which are all associated with coronal mass ejections observed by SOHO/LASCO. The erupting plasmas are observed as absorption or emission features in the low corona. The absorption feature provides a lower limit to the cold mass while the emission feature provides an upper limit to the mass of observed plasma in X-ray and EUV. We compare the mass constraints for each temperature response and find that the mass estimates in EUV and XRT are smaller than the total mass in the coronagraph. Several events were observed by a few passbands in the X-rays, which allows us to determine the temperature of the eruptive plasma using a filter ratio method. The temperature of one event is estimated at about 8.6 MK near the top of the erupting plasma. This measurement is possibly an average temperature for higher temperature plasma because the XRT is more sensitive at higher temperatures. In addition, a few events show that the absorption features of a prominence or a loop change to emission features with the beginning of their eruptions in all EUV wavelengths of SDO/AIA, which indicates the heating of the plasma. By estimating the physical properties of the erupting plasmas, we discuss the heating of the plasmas associated with coronal mass ejections in the low corona.

  17. Compression mass gauge testing in a liquid hydrogen dewar

    NASA Technical Reports Server (NTRS)

    Jurns, J. M.; Rogers, A. C.

    1995-01-01

    This paper describes testing that was conducted using a mass gauge in a liquid hydrogen environment. The mass gauge, herein referred to as the 'compressibility gauge,' is being developed as a means to accurately determine the mass of liquid contained in a tank in a low-gravity environment. The concept is based on the thermodynamic principle that the pressure of gas or vapor changes when its volume changes. Previous work has been conducted by Southwest Research Institute in collaboration with NASA Lewis Research Center. This consisted of testing the concept with water and other cryogenic simulant fluids. The purpose of conducting liquid hydrogen tests is to test the concept in actual cryogenic conditions, and address hardware issues that arise in fabricating a test article for use in liquid hydrogen.

  18. High-speed impact test using an inertial mass and an optical interferometer

    NASA Astrophysics Data System (ADS)

    Jin, T.; Watanabe, K.; Prayogi, I. A.; Takita, A.; Mitatha, S.; Djamal, M.; Jia, H. Z.; Hou, W. M.; Fujii, Y.

    2013-07-01

    A high-speed impact testing method for evaluating mechanical properties of materials is proposed using an inertial mass and a dual beat-frequencies laser Doppler interferometer (DB-LDI). In this method, an inertial mass levitated using an aerostatic linear bearing is made to collide with the material being tested at a high initial velocity. During the collision, the velocity of the mass, which is even higher than the critical velocity (±0.56 m/s) defined by the frequency difference of the Zeeman laser, is accurately measured using the DB-LDI. The position, acceleration, and impact force of the mass are calculated from the measured velocity. Using the proposed method, the mechanical properties of a visco-elastic material under a high-speed impact loading condition can be accurately evaluated.

  19. Investigation of sources, properties and preparation of distillate test fuels

    NASA Technical Reports Server (NTRS)

    Bowden, J. N.; Erwin, J.

    1983-01-01

    Distillate test fuel blends were generated for prescribed variations in composition and physical properties. Fuels covering a wide range in properties and composition which would provide a matrix of fuels for possible use in future combustion research programs were identified. Except for tetralin the blending components were all from typical refinery streams. Property variation blends span a boiling range within 150 C to 335 C, freezing point -23 C to -43 C, aromatic content 20 to 50 volume percent, hydrogen content 11.8 to 14.2 mass percent, viscosity 4 and 11 cSt (-20 C), and naphthalenes 8 and 16 volume percent. Composition variation blends were made with two base stocks, one paraffinic and the other napthenic. To each base stock was added each of three aromatic type fuels (alkyl benzenes, tetralin, and naphthalenes) for assigned initial boiling point, final boiling point, and hydrogen content. The hydrogen content was 13.5 mass percent for the paraffinic base stock blends and 12.5 mass percent and 11.5 mass percent for the naphthenic base stock blends. Sample 5-gallon quantities of all blends were prepared and analyzed.

  20. Test of pressure transducer for measuring cotton-mass flow

    USDA-ARS?s Scientific Manuscript database

    In this study, a cotton harvester yield monitor was developed based on the relationship between air pressure and the mass of seed cotton conveyed. The sensor theory was verified by laboratory tests. The sensor was tested on a cotton picker with seed cotton at two moisture contents, 5.9% and 8.5% we...

  1. Supermassive Black Hole Masses and Global Properties of Disk Galaxies

    NASA Astrophysics Data System (ADS)

    Castillo, Y. S.; Funes, J. G.; Díaz, R. J.

    2006-06-01

    Different scaling laws are known for the mass of supermassive black holes (M_{BH}): M_{BH}-σ M_{BH}-M_{Bulge}; M_{BH}-M_{DM}. We have reviewed these correlations for 17 disk galaxies and tried to find any correlation between M_{BH} and other disk properties (HI and H_2 masses, far infrared luminosity, star formation rate, etc.). The sample was taken from Marconi and Hunt (2003). For these galaxies we have done a search in the literature for the following properties: A) in the nucleus: star formation rates, and luminosities in Hα ; B) in the bulge: luminosity in B-band; C) in the disk: HI and H_2 total masses, total luminosities in X-ray, B band and far infrared, and total star formation rate. In this work we present the compiled data from the literature and the plots of M_{BH} against galaxy HI total mass, M_{BH} against galaxy H_2 total mass, and M_{BH} against disk blue luminosity. We did not find any evident correlation between the M_{BH} and the properties of the disk.

  2. Munition Mass Properties Measurement Procedures Using a Spin Balance Machine

    DTIC Science & Technology

    2015-03-09

    determines the mass properties, balance configurations, and balance specification(s) of live or inert munitions; namely, the Center of Gravity (CG...the Moment of Inertia (MOI), and the Product of Inertia (POI). 15. SUBJECT TERMS Center of Gravity Product of Inertia Moment of Inertia Spin...B-1 C. CENTER OF GRAVITY ...................................................... C-1 D

  3. Quadrotor Control in the Presence of Unknown Mass Properties

    NASA Astrophysics Data System (ADS)

    Duivenvoorden, Rikky Ricardo Petrus Rufino

    Quadrotor UAVs are popular due to their mechanical simplicity, as well as their capability to hover and vertically take-off and land. As applications diversify, quadrotors are increasingly required to operate under unknown mass properties, for example as a multirole sensor platform or for package delivery operations. The work presented here consists of the derivation of a generalized quadrotor dynamic model without the typical simplifying assumptions on the first and second moments of mass. The maximum payload capacity of a quadrotor in hover, and the observability of the unknown mass properties are discussed. A brief introduction of L1 adaptive control is provided, and three different L 1 adaptive controllers were designed for the Parrot AR.Drone quadrotor. Their tracking and disturbance rejection performance was compared to the baseline nonlinear controller in experiments. Finally, the results of the combination of L1 adaptive control with iterative learning control are presented, showing high performance trajectory tracking under uncertainty.

  4. RSRM-11 (36OW011) ballistics mass properties (STS-35)

    NASA Technical Reports Server (NTRS)

    Hutchinson, B. J.; Gruet, L. P.; Richards, M. C.

    1991-01-01

    The propulsion performance and reconstructed mass properties data from Thiolol's RSRM-11 motors which were assigned to the STS-35 launch are contained. The Thiokol manufacturing designations for the motors were 360W011A/360W011B, which are referred to as RSRM-11A and RSRM-B, respectively. The launch of STS-35 occurred on 2 December 1990 at the Eastern Test Range (ETR). The data contained herein was input to the STS-35 Flight Evaluation Report. The SRM propellant, TP-H1148, is a composite type solid propellants, formulated of polybutediene acrylic acid, acryonitrile terpolymer binder, epoxy curing agent, ammonium perchlorate oxidizer, and aluminum powder fuel. A small amount of burning rate catalyst (iron oxide) was added to achieve the desired propellant burn rate. The propellant evaluation and raw material information for the RSRM-11 are included. The ballistic performance presented was based on the Operational Flight Instrumentation (OFI) 12.5 sample per second pressure data for the steady state and tail off portion of the pressure trace. Recent studies have shown that the transducers are affected by the measuring system at KSC and temperature gradients created by the igniter heaters. Therefore, an adjustment to the data from each transducer is made to make the initial reading match the atmospheric pressure at the time of launch.

  5. Machining as a mechanical property test revisited

    NASA Astrophysics Data System (ADS)

    Smith, David L.

    There is much need for data on mechanical behavior of metals at high strains and strain rates. This need is dictated by modeling of processes like forming and machining, wherein the material in the deformation zone is subjected to severe deformation conditions atypical of conventional material property tests such as tension and torsion. Accurate flow stress data is an essential input for robust prediction of process outputs. Similar requirements arise from applications in high speed ballistic penetration and design of materials for armor. Since the deformation zone in cutting of metals is characterized by unique and extreme combinations of strain, strain rate and temperature, an opportunity exists for using plane-strain cutting as a mechanical property test for measuring flow properties of metals. The feasibility of using plane-strain cutting to measure flow properties of metals is revisited in the light of recent data showing controllability of the deformation conditions in chip formation by systematic variation of process input parameters. A method is outlined as to how the deformation conditions can be varied by changing the process parameters. The method is applied to cutting of commercially pure copper (FCC), iron (BCC) and zinc (HCP). Forces and chip geometries are measured, in conjunction with particle image velocimetry characterization of the deformation using high speed image sequences. The flow stresses are estimated from these measurements. The measured flow stress and its dependence on strain are shown to agree well with prior measurements of these parameters using conventional tests, and flow stress inferred from hardness characterization. The method is also demonstrated to be able to measure properties of metals that recrystallize at room temperature (zinc), wherein quasi-static tests predict much lower strength. Sources of variability and uncertainty in the application of this measurement technique are discussed. Future work in the context of further

  6. ESTEC wiring test programme materials related properties

    NASA Technical Reports Server (NTRS)

    Judd, M. D.

    1994-01-01

    Electrical wires are considered as EEE parts and are covered within the ESA SCC specification series (ESA SCC 3901/XXX). This specification defines the principal properties of the wires including insulation/lay-up and electrical properties. Some additional space related materials requirements are also included, requirements such as outgassing and silver plating thickness. If a project has additional materials requirements over and above those covered by the relevant SCC specification, then additional testing is required. This is especially true for crewed spacecraft. The following topics are discussed in this context: additional requirements for manned spacecraft; flammability; arc tracking; thermal decomposition; microbial surface growth; and ageing.

  7. ESTEC wiring test programme materials related properties

    NASA Technical Reports Server (NTRS)

    Judd, M. D.

    1994-01-01

    Electrical wires are considered as EEE parts and are covered within the ESA SCC specification series (ESA SCC 3901/XXX). This specification defines the principal properties of the wires including insulation/lay-up and electrical properties. Some additional space related materials requirements are also included, requirements such as outgassing and silver plating thickness. If a project has additional materials requirements over and above those covered by the relevant SCC specification, then additional testing is required. This is especially true for crewed spacecraft. The following topics are discussed in this context: additional requirements for manned spacecraft; flammability; arc tracking; thermal decomposition; microbial surface growth; and ageing.

  8. COMPREHENSIVE ANALYSIS OF CORONAL MASS EJECTION MASS AND ENERGY PROPERTIES OVER A FULL SOLAR CYCLE

    SciTech Connect

    Vourlidas, A.; Howard, R. A.; Esfandiari, E.; Patsourakos, S.; Yashiro, S.; Michalek, G.

    2010-10-20

    The LASCO coronagraphs, in continuous operation since 1995, have observed the evolution of the solar corona and coronal mass ejections (CMEs) over a full solar cycle with high-quality images and regular cadence. This is the first time that such a data set becomes available and constitutes a unique resource for the study of CMEs. In this paper, we present a comprehensive investigation of the solar cycle dependence on the CME mass and energy over a full solar cycle (1996-2009) including the first in-depth discussion of the mass and energy analysis methods and their associated errors. Our analysis provides several results worthy of further studies. It demonstrates the possible existence of two event classes: 'normal' CMEs reaching constant mass for >10 R{sub sun} and {sup p}seudo{sup -}CMEs which disappear in the C3 field of view. It shows that the mass and energy properties of CME reach constant levels and therefore should be measured only above {approx}10 R{sub sun}. The mass density (g/R {sup 2}{sub sun}) of CMEs varies relatively little (< order of magnitude) suggesting that the majority of the mass originates from a small range in coronal heights. We find a sudden reduction in the CME mass in mid-2003 which may be related to a change in the electron content of the large-scale corona and we uncover the presence of a 6 month periodicity in the ejected mass from 2003 onward.

  9. Mass-Flow-Meter Leak-Testing System

    NASA Technical Reports Server (NTRS)

    Sorensen, Eric B.; Polidori, Andre V.; Heman, Joe R.; Dresser, Holland L.; Hellum, John

    1996-01-01

    Improved leak-testing system incorporates mass-flow meter as primary sensor for measurement of leakage rate. System easier to use and more reliable and enables leak tests to be completed in less time. Produces test data more plentiful, more accurate, and better suited to leak detection and diagnosis. Operates over range of test conditions, including pressures from atmospheric to 1,000 psi, temperatures from 50 to 120 degrees F and volumes from less than 1 in.(sup3) to 22 in.(sup3). Sensitive enough to measure absorbed gas seeping from O-ring seals after test pressure released.

  10. Note: Discharging fused silica test masses with ionized nitrogen

    NASA Astrophysics Data System (ADS)

    Ugolini, D.; Funk, Q.; Amen, T.

    2011-04-01

    We have developed a technique for discharging fused silica test masses in a gravitational-wave interferometer with nitrogen ionized by an electron beam. The electrons are produced from a heated filament by thermionic emission in a low-pressure region to avoid contamination and burnout. Some electrons then pass through a small aperture and ionize nitrogen in a higher-pressure region, and this ionized gas is pumped across the test mass surface, neutralizing both polarities of charge. The discharge rate varies exponentially with charge density and filament current, quadratically with filament potential, and has an optimal working pressure of ˜8 mT. Adapting the technique to larger test mass chambers is also discussed.

  11. 240 nm UV LEDs for LISA test mass charge control

    NASA Astrophysics Data System (ADS)

    Olatunde, Taiwo; Shelley, Ryan; Chilton, Andrew; Serra, Paul; Ciani, Giacomo; Mueller, Guido; Conklin, John

    2015-05-01

    Test Masses inside the LISA Gravitational Reference Sensor must maintain almost pure geodesic motion for gravitational waves to be successfully detected. LISA requires residual test mass accelerations below 3 fm/s2/√Hz at all frequencies between 0.1 and 3 mHz. One of the well-known noise sources is associated with the charges on the test masses which couple to stray electrical potentials and external electromagnetic fields. LISA Pathfinder will use Hg-discharge lamps emitting mostly around 254 nm to discharge the test masses via photoemission in its 2015/16 flight. A future LISA mission launched around 2030 will likely replace the lamps with newer UV-LEDs. Presented here is a preliminary study of the effectiveness of charge control using latest generation UV-LEDs which produce light at 240 nm with energy above the work function of pure Au. Their lower mass, better power efficiency and small size make them an ideal replacement for Hg lamps.

  12. Lithophysal Rock Mass Mechanical Properties of the Repository Host Horizon

    SciTech Connect

    D. Rigby

    2004-11-10

    The purpose of this calculation is to develop estimates of key mechanical properties for the lithophysal rock masses of the Topopah Spring Tuff (Tpt) within the repository host horizon, including their uncertainties and spatial variability. The mechanical properties to be characterized include an elastic parameter, Young's modulus, and a strength parameter, uniaxial compressive strength. Since lithophysal porosity is used as a surrogate property to develop the distributions of the mechanical properties, an estimate of the distribution of lithophysal porosity is also developed. The resulting characterizations of rock parameters are important for supporting the subsurface design, developing the preclosure safety analysis, and assessing the postclosure performance of the repository (e.g., drift degradation and modeling of rockfall impacts on engineered barrier system components).

  13. Computer program for determining mass properties of a rigid structure

    NASA Technical Reports Server (NTRS)

    Hull, R. A.; Gilbert, J. L.; Klich, P. J.

    1978-01-01

    A computer program was developed for the rapid computation of the mass properties of complex structural systems. The program uses rigid body analyses and permits differences in structural material throughout the total system. It is based on the premise that complex systems can be adequately described by a combination of basic elemental shapes. Simple geometric data describing size and location of each element and the respective material density or weight of each element were the only required input data. From this minimum input, the program yields system weight, center of gravity, moments of inertia and products of inertia with respect to mutually perpendicular axes through the system center of gravity. The program also yields mass properties of the individual shapes relative to component axes.

  14. Mechanical Properties of Mass Concrete at Early Ages

    DTIC Science & Technology

    1991-08-01

    material properties during the time that concrete is undergoing the greatest amount of thermal activity and physical change (i.e. early ages, less than 3...Type II, low alkali (LA) portland cement meeting ASTM C 150 and a Class C fly ash meeting ASTM C 618 [11 i]. The fine aggregate was a natural sand...usually require that specially developed or modified models be used. It should also be noted that the use- of high percentages of pozzolans in mass

  15. Mass Testing and the Underdevelopment of Inner-City Communities.

    ERIC Educational Resources Information Center

    Hesch, Rick

    2000-01-01

    Mass testing as a phenomena of global educational restructuring exacerbates social class differences. This phenomenon is examined via inner-city Winnipeg's experience, cross-cultural educational literature, and the Manitoba government's tendency to reinforce the underdevelopment of core area regions. Emerging resistance to educational…

  16. Estimating the Deformability and Strength of Rock Masses - In-Situ Tests, and Related Procedures

    SciTech Connect

    Heuze, F E

    2003-06-01

    This report was prepared for presentation at the STRATCOM Advanced Concept Technology Demonstration (ACTD) meeting held in Albuquerque, New Mexico, May 21, 2003. It discusses the methods that can be used to estimate the mechanical properties of rock masses, such as deformability and strength. Special emphasis is put on the fact that rock mass properties are subject to an effect of scale, i.e. the properties measured on laboratory-scale samples are not representative of in-situ properties because of the presence of geologic discontinuities. This information is relevant to the planning of new field tests to assess the effects of explosions in the ground that are part of the on-going ACTD.

  17. Unsaturated hydraulic properties determined from geocentrifuge tests

    NASA Astrophysics Data System (ADS)

    Nakajima, H.; Mattson, E. D.; Stadler, A. T.

    2003-12-01

    The geocentrifuge is a useful tool for studying flow in unsaturated soil under well-controlled, repeatable conditions. The high-gravity field generated by the geocentrifuge increases the self-weight of pore fluids to produce: (1) very low saturation conditions at high capillary pressures, (2) a wide range of saturation profiles in multi-dimension, and (3) enhanced seepage velocities. Geocentrifuge experiments can be used to generate experimental data to validate mathematical models. However, if an unsaturated flow experiment is performed in the elevated gravity environment of the geocentrifuge, the unsaturated hydraulic properties must first be obtained at the target centrifugal acceleration. This information can be determined from relatively simple, one-dimensional column experiments and will provide the unsaturated hydraulic properties required as input into mathematical models. These one-dimensional column experiments will also provide insight into the influence of gravity on the flow field. In this study, a series of one-dimensional column experiments was performed to obtain the water retention characteristics of a uniform fine sand. Cumulative outflow and temporal changes of capillary pressures were measured during gravity driven drainage. The measured data were used as input data for an inverse analysis using HYDRUS 1-D to obtain unsaturated permeability and saturation-pressure parameters of the tested sand. The geocentrifuge experimental measurements were also compared with data obtained independently from conventional hanging-column tests. The suitability of the centrifuge test method was evaluated by comparing results from the two different experimental methods. In addition, the centrifuge experiments were conducted in different gravity fields to verify the scale similitude of the hydraulic properties in elevated gravity environments.

  18. Bound nucleons have unique masses that govern elemental properties

    NASA Astrophysics Data System (ADS)

    Pamfiloff, Eugene

    2005-07-01

    It is known that measured binding energies associated with elements require equivalent energy to break the nuclear bond of a nucleus. Based upon the proposals contained in recent published works [1] [2] and with support from experimental high-energy data, it can be shown that a portion of listed binding energies are attributable to bound nucleons having a unique mass for every element. The figures show, relative to the hydrogen proton, that of the: a) 1.112 MeV binding energy per nucleon for 2H, 44% or 0.486 MeV represents a change in mass (δm) for the proton or neutron; b) of 5.629 MeV binding energy per nucleon for 7Li, 87% or 4.890 MeV represents a change of mass for each nucleon; c) likewise, 56Fe has 8.811 MeV binding energy per nucleon and of this 92% or 8.119 MeV represents a change in mass for each nucleon, and 232Th has 7.639 MeV binding energy per nucleon and of this, 90% or 6.848 MeV represents a change in mass for each nucleon. This demonstrates that the nucleons of each element have unique masses. It has been shown that if three protons are removed from 82Pb the result is not 79Au; therefore, we conclude and predict that in addition to the Z number, elemental properties are determined by the unique proton and neutron masses for each element. mailto:megforce@physast.uga.edumegforce@physast.uga.edu [1] ``The Order of the Forces'', [2] ``The Geatron Nuclear Model''

  19. Bound nucleons have unique masses that govern elemental properties

    NASA Astrophysics Data System (ADS)

    Pamfiloff, Eugene

    2005-04-01

    It is know that measured binding energies associated with elements require equivalent energy to break the nuclear bond of a nucleus. Based upon the proposals contained in a recent published work [1] and with support from experimental high-energy data, it can be shown that a portion of listed binding energies are attributed to bound nucleons having a unique mass for every element. The figures show, relative to the hydrogen proton, that of the: a) 1.112 MeV binding energy per nucleon for ^2H, 44% or 0.486 MeV represents a change in mass for the proton and neutron; b) of 5.629 MeV binding energy per nucleon for ^7Li, 87% or 4.890 MeV represents a change of mass for each nucleon; c) likewise, ^56Fe has 8.811 MeV binding energy per nucleon and of this 92% or 8.119 MeV represents a change in mass for each nucleon; and ^232Th has 7.639 MeV binding energy per nucleon and of this, 90% or 6.848 MeV represents a change in mass for each nucleon. This demonstrates that the nucleons of each element have unique masses. It can be shown that if three protons are removed from 82Pb the result is not 79Au. We conclude and predict that in addition to the Z number, elemental properties are determined by the unique proton and neutron masses for each element. [1] mailto:megforce@physast.uga.edumegforce@physast.uga.edu ``The Order of the Forces''

  20. Bound nucleons have unique masses that govern elemental properties

    NASA Astrophysics Data System (ADS)

    Pamfiloff, Eugene

    2005-03-01

    It is known that measured binding energies associated with elements require equivalent energy to break the nuclear bond of a nucleus. Based upon the proposals contained in recent published works [1] [2] and with support from experimental high-energy data, it can be shown that a portion of listed binding energies are attributable to bound nucleons having a unique mass for every element. The figures show, relative to the hydrogen proton, that of the: a) 1.112 MeV binding energy per nucleon for 2H, 44% or 0.486 MeV represents a change in mass (δm) for the proton or neutron; b) of 5.629 MeV binding energy per nucleon for 7Li, 87% or 4.890 MeV represents a change of mass for each nucleon; c) likewise, 56Fe has 8.811 MeV binding energy per nucleon and of this 92% or 8.119 MeV represents a change in mass for each nucleon, and 232Th has 7.639 MeV binding energy per nucleon and of this, 90% or 6.848 MeV represents a change in mass for each nucleon. This demonstrates that the nucleons of each element have unique masses. It has been shown that if three protons are removed from 82Pb the result is not 79Au; therefore, we conclude and predict that in addition to the Z number, elemental properties are determined by the unique proton and neutron masses for each element. mailto:megforce@physast.uga.edumegforce@physast.uga.edu [1] ``The Order of the Forces'', [2] ``The Geatron Nuclear Model''

  1. Validation of a Compression Mass Gauge using ground tests for liquid propellant mass measurements

    NASA Astrophysics Data System (ADS)

    Fu, Juan; Chen, Xiaoqian; Huang, Yiyong; Li, Xiaolong

    2014-05-01

    To properly estimate orbital lifetimes and predict the maneuverability of spacecraft, the remaining liquid propellant mass must be accurately known at every moment of a space mission. This paper studies the Compression Mass Gauge (CMG) method to determine the mass of liquid contained in a tank in a low-gravity environment with high accuracy. CMG is a thermodynamic method used to determine the quantity of liquid by measuring the gas pressure change when the tank volume changes, and has been previously theoretically and experimentally studied by researchers. The primary objective of this investigation is to explore the effects of attitude disturbance and the spacecraft thermal environment on the accuracy of the method. A ground test system, consisting of several test apparatuses, was fabricated and described as part of this study. The test results and analyses indicate that the CMG performs well and has an accuracy of ±1%. Additionally, demonstrations were performed to show that measurement errors do not increase drastically or exceed ±1% when the test system is vibrated to simulate the tank being perturbed as a result of an attitude disturbance. Liquid sloshing resonance was found to have a significant effect on the gauging accuracy. Measurements in a real thermal environment in which heat transfers into and out of the propellant tank were also conducted. The results show that the gauging accuracy is acceptable for normal liquid propellant. Furthermore, theoretical research shows that heat leakage has a significant influence on cryogenic propellant mass gauging.

  2. The Wind and Mass-loss Properties of the Most Massive Stars

    NASA Astrophysics Data System (ADS)

    Bestenlehner, Joachim; Vink, Jorick; Gräfener, Götz; Najarro, Francisco

    2013-06-01

    Mass-loss rates play an important role in the evolution of massive stars. The initial, present day and the mass at their end of their lifetime is considerable different as a result of mass loss. Different stages of evolution have different mass-loss rates. The understanding of massive star evolution is tightly connected to the understanding of their mass loss properties. In the context of the VLT-Flames Tarantula Survey I will present the results from our spectral analysis of stars in the transition region from O-stars to very massive WN(h)-stars. WN(h)-stars are very young and massive stars which develop already in the earliest stages of their evolution WR-star like winds. For the analysis we used the non-LTE radiative transfer code CMFGEN to investigate the wind and mass-loss properties of these very massive stars. This analysis also tests theoretical predictions which suggest a notable change of the mass-loss behaviour at a certain Eddington factor in the transition region from O to WN(h)-stars (Bestenlehner et al. 2011, Bestenlehner et al. in prep.)

  3. Properties of nuclear matter from macroscopic-microscopic mass formulas

    NASA Astrophysics Data System (ADS)

    Wang, Ning; Liu, Min; Ou, Li; Zhang, Yingxun

    2015-12-01

    Based on the standard Skyrme energy density functionals together with the extended Thomas-Fermi approach, the properties of symmetric and asymmetric nuclear matter represented in two macroscopic-microscopic mass formulas: Lublin-Strasbourg nuclear drop energy (LSD) formula and Weizsäcker-Skyrme (WS*) formula, are extracted through matching the energy per particle of finite nuclei. For LSD and WS*, the obtained incompressibility coefficients of symmetric nuclear matter are K∞ = 230 ± 11 MeV and 235 ± 11 MeV, respectively. The slope parameter of symmetry energy at saturation density is L = 41.6 ± 7.6 MeV for LSD and 51.5 ± 9.6 MeV for WS*, respectively, which is compatible with the liquid-drop analysis of Lattimer and Lim [4]. The density dependence of the mean-field isoscalar and isovector effective mass, and the neutron-proton effective masses splitting for neutron matter are simultaneously investigated. The results are generally consistent with those from the Skyrme Hartree-Fock-Bogoliubov calculations and nucleon optical potentials, and the standard deviations are large and increase rapidly with density. A better constraint for the effective mass is helpful to reduce uncertainties of the depth of the mean-field potential.

  4. The core mass-radius relation for giants - A new test of stellar evolution theory

    NASA Technical Reports Server (NTRS)

    Joss, P. C.; Rappaport, S.; Lewis, W.

    1987-01-01

    It is demonstrated here that the measurable properties of systems containing degenerate dwarfs can be used as a direct test of the core mass-radius relation for moderate-mass giants if the final stages of the loss of the envelope of the progenitor giant occurred via stable critical lobe overflow. This relation directly probes the internal structure of stars at a relatively advanced evolutionary state and is only modestly influenced by adjustable parameters. The measured properties of six binary systems, including such diverse systems as Sirius and Procyon and two millisecond pulsars, are utilized to derive constraints on the empirical core mass-radius relation, and the constraints are compared to the theoretical relation. The possibility that the final stages of envelope ejection of the giant progenitor of Sirius B occurred via critical lobe overflow in historical times is considered.

  5. The core mass-radius relation for giants - A new test of stellar evolution theory

    NASA Technical Reports Server (NTRS)

    Joss, P. C.; Rappaport, S.; Lewis, W.

    1987-01-01

    It is demonstrated here that the measurable properties of systems containing degenerate dwarfs can be used as a direct test of the core mass-radius relation for moderate-mass giants if the final stages of the loss of the envelope of the progenitor giant occurred via stable critical lobe overflow. This relation directly probes the internal structure of stars at a relatively advanced evolutionary state and is only modestly influenced by adjustable parameters. The measured properties of six binary systems, including such diverse systems as Sirius and Procyon and two millisecond pulsars, are utilized to derive constraints on the empirical core mass-radius relation, and the constraints are compared to the theoretical relation. The possibility that the final stages of envelope ejection of the giant progenitor of Sirius B occurred via critical lobe overflow in historical times is considered.

  6. Unbalanced rock mass vibration generator and its bench testing

    NASA Astrophysics Data System (ADS)

    Rybalkin, LA; Azarov, AV; Serdyukov, AS

    2017-02-01

    This work presents an unbalanced borehole vibration source with the pneumatic actuator to affect the rock mass bottomhole zone in the seismic frequency range. The modulus-type source consists of the vibration generator with automatic step regulation of static moment, clamping node and built-in pneumatic device to transfer equipment in uncased boreholes. There are test results on the source prototype, amplitude and frequency characteristics and spectral content of the source signal.

  7. Relation between mass balance aperture and hydraulic properties from field experiments in fractured rock in Sweden

    NASA Astrophysics Data System (ADS)

    Hjerne, Calle; Nordqvist, Rune

    2014-09-01

    Results from tracer tests are often used to infer connectivity and transport properties in bedrock. However, the amount of site-specific data from tracer tests is often very limited, while data from hydraulic tests are more abundant. It is therefore of great interest for predictive transport modeling to use hydraulic data to infer transport properties. In this study, data from cross-hole tracer tests carried out in crystalline bedrock in Sweden were compiled and analysed. The tests were performed within investigations made by the Swedish Nuclear Fuel and Waste Management Company (SKB) between 1978 and 2009 at five different locations. An empirical relationship between mass balance aperture and transmissivity was found and quantified by using 74 observations. The empirical relationship deviates considerably from the cubic law aperture, as mass balance aperture is found to be at least one order of magnitude larger than cubic law aperture. Hence, usage of cubic law aperture, derived from hydraulic testing, for transport predictions is unsuitable, as the advective transport time will be considerably underestimated. Another result, from the data set studied, is that mass balance aperture appears to correlate better to apparent storativity than to transmissivity.

  8. Force Limited Random Vibration Test of TESS Camera Mass Model

    NASA Technical Reports Server (NTRS)

    Karlicek, Alexandra; Hwang, James Ho-Jin; Rey, Justin J.

    2015-01-01

    The Transiting Exoplanet Survey Satellite (TESS) is a spaceborne instrument consisting of four wide field-of-view-CCD cameras dedicated to the discovery of exoplanets around the brightest stars. As part of the environmental testing campaign, force limiting was used to simulate a realistic random vibration launch environment. While the force limit vibration test method is a standard approach used at multiple institutions including Jet Propulsion Laboratory (JPL), NASA Goddard Space Flight Center (GSFC), European Space Research and Technology Center (ESTEC), and Japan Aerospace Exploration Agency (JAXA), it is still difficult to find an actual implementation process in the literature. This paper describes the step-by-step process on how the force limit method was developed and applied on the TESS camera mass model. The process description includes the design of special fixtures to mount the test article for properly installing force transducers, development of the force spectral density using the semi-empirical method, estimation of the fuzzy factor (C2) based on the mass ratio between the supporting structure and the test article, subsequent validating of the C2 factor during the vibration test, and calculation of the C.G. accelerations using the Root Mean Square (RMS) reaction force in the spectral domain and the peak reaction force in the time domain.

  9. Control System Upgrade for a Mass Property Measurement Facility

    NASA Technical Reports Server (NTRS)

    Chambers, William; Hinkle, R. Kenneth (Technical Monitor)

    2002-01-01

    The Mass Property Measurement Facility (MPMF) at the Goddard Space Flight Center has undergone modifications to ensure the safety of Flight Payloads and the measurement facility. The MPMF has been technically updated to improve reliability and increase the accuracy of the measurements. Modifications include the replacement of outdated electronics with a computer based software control system, the addition of a secondary gas supply in case of a catastrophic failure to the gas supply and a motor controlled emergency stopping feature instead of a hard stop.

  10. Kalman Filter for Mass Property and Thrust Identification (MMS)

    NASA Technical Reports Server (NTRS)

    Queen, Steven

    2015-01-01

    The Magnetospheric Multiscale (MMS) mission consists of four identically instrumented, spin-stabilized observatories, elliptically orbiting the Earth in a tetrahedron formation. For the operational success of the mission, on-board systems must be able to deliver high-precision orbital adjustment maneuvers. On MMS, this is accomplished using feedback from on-board star sensors in tandem with accelerometers whose measurements are dynamically corrected for errors associated with a spinning platform. In order to determine the required corrections to the measured acceleration, precise estimates of attitude, rate, and mass-properties is necessary. To this end, both an on-board and ground-based Multiplicative Extended Kalman Filter (MEKF) were formulated and implemented in order to estimate the dynamic and quasi-static properties of the spacecraft.

  11. Observed Properties of Exoplanets: Masses, Orbits, and Metallicities

    NASA Astrophysics Data System (ADS)

    Marcy, G.; Butler, R. P.; Fischer, D.; Vogt, S.; Wright, J. T.; Tinney, C. G.; Jones, H. R. A.

    We review the observed properties of exoplanets found by the Doppler technique that has revealed 152 planets to date. We focus on the ongoing 18-year survey of 1330 FGKM type stars at Lick, Keck, and the Anglo-Australian Telescopes that offers both uniform Doppler precision (3 m s-1) and long duration. The 104 planets detected in this survey have minimum masses (M sin i) as low as 6 MEarth, orbiting between 0.02 and 6 AU. The core-accretion model of planet formation is supported by four observations: 1) The mass distribution rises toward the lowest detectable masses, dN/dM ∝ M-1.0. 2) Stellar metallicity correlates strongly with the presence of planets. 3) One planet (1.3 MSat) has a massive rocky core, MCore ≈ 70 MEarth. 4) A super-Earth of ˜ 7 MEarth has been discovered. The distribution of semi-major axes rises from 0.3 -- 3.0 AU (dN/d log a) and extrapolation suggests that ˜12% of the FGK stars harbor gas-giant exoplanets within 20 AU. The median orbital eccentricity is < e > = 0.25, and even planets beyond 3 AU reside in eccentric orbits, suggesting that the circular orbits in our Solar System are unusual. The occurrence ``hot Jupiters'' within 0.1 AU of FGK stars is 1.2 ± 0.2%. Among stars with one planet, 14% have at least one additional planet, occasionally locked in resonances. Kepler and COROT will measure the occurrence of earth-sized planets. The Space Interferometry Mission (SIM) will detect planets with masses as low as 3 MEarth orbiting within 2 AU of stars within 10 pc, and it will measure masses, orbits, and multiplicity. The candidate rocky planets will be amenable to follow-up spectroscopy by the ``Terrestrial Planet Finder'' and Darwin.

  12. Analysis of borehole expansion and gallery tests in anisotropic rock masses

    USGS Publications Warehouse

    Amadei, B.; Savage, W.Z.

    1991-01-01

    Closed-form solutions are used to show how rock anisotropy affects the variation of the modulus of deformation around the walls of a hole in which expansion tests are conducted. These tests include dilatometer and NX-jack tests in boreholes and gallery tests in tunnels. The effects of rock anisotropy on the modulus of deformation are shown for transversely isotropic and regularly jointed rock masses with planes of transverse isotropy or joint planes parallel or normal to the hole longitudinal axis for plane strain or plane stress condition. The closed-form solutions can also be used when determining the elastic properties of anisotropic rock masses (intact or regularly jointed) in situ. ?? 1991.

  13. Expanded newborn screening by mass spectrometry: New tests, future perspectives.

    PubMed

    Ombrone, Daniela; Giocaliere, Elisa; Forni, Giulia; Malvagia, Sabrina; la Marca, Giancarlo

    2016-01-01

    Tandem mass spectrometry (MS/MS) has become a leading technology used in clinical chemistry and has shown to be particularly sensitive and specific when used in newborn screening (NBS) tests. The success of tandem mass spectrometry is due to important advances in hardware, software and clinical applications during the last 25 years. MS/MS permits a very rapid measurement of many metabolites in different biological specimens by using filter paper spots or directly on biological fluids. Its use in NBS give us the chance to identify possible treatable metabolic disorders even when asymptomatic and the benefits gained by this type of screening is now recognized worldwide. Today the use of MS/MS for second-tier tests and confirmatory testing is promising especially in the early detection of new disorders such as some lysosomal storage disorders, ADA and PNP SCIDs, X-adrenoleucodistrophy (X-ALD), Wilson disease, guanidinoacetate methyltransferase deficiency (GAMT), and Duchenne muscular dystrophy. The new challenge for the future will be reducing the false positive rate by using second-tier tests, avoiding false negative results by using new specific biomarkers and introducing new treatable disorders in NBS programs.

  14. Wiring test program insulation material related properties

    NASA Technical Reports Server (NTRS)

    Reher, Heinz-Josef

    1995-01-01

    This viewgraph presentation provides an overview of activities at DASA-RI concerning the testing of wires for manned spacecraft, including test facilities, arc-tracking tests, flammability tests, microgravity tests, and standardization, and outlines future activities.

  15. Testing and Validation of Computational Methods for Mass Spectrometry.

    PubMed

    Gatto, Laurent; Hansen, Kasper D; Hoopmann, Michael R; Hermjakob, Henning; Kohlbacher, Oliver; Beyer, Andreas

    2016-03-04

    High-throughput methods based on mass spectrometry (proteomics, metabolomics, lipidomics, etc.) produce a wealth of data that cannot be analyzed without computational methods. The impact of the choice of method on the overall result of a biological study is often underappreciated, but different methods can result in very different biological findings. It is thus essential to evaluate and compare the correctness and relative performance of computational methods. The volume of the data as well as the complexity of the algorithms render unbiased comparisons challenging. This paper discusses some problems and challenges in testing and validation of computational methods. We discuss the different types of data (simulated and experimental validation data) as well as different metrics to compare methods. We also introduce a new public repository for mass spectrometric reference data sets ( http://compms.org/RefData ) that contains a collection of publicly available data sets for performance evaluation for a wide range of different methods.

  16. The Effect of Scale on the Mechanical Properties of Jointed Rock Masses

    SciTech Connect

    Heuze, F E

    2004-05-24

    These notes were prepared for presentation at the Defense Threat Reduction Agency's (DTRA) Hard Target Research and Analysis Center (HTRAC), at the occasion of a short course held on June 14-15, 2004. The material is intended for analysts who must evaluate the geo-mechanical characteristics of sites of interest, in order to provide appropriate input to calculations of ground shock effects on underground facilities in rock masses. These analysts are associated with the Interagency Geotechnical Assessment Team (IGAT). Because geological discontinuities introduce scale effects on the mechanical properties of rock formations, these large-scale properties cannot be estimated on the basis of tests on small cores.

  17. Method For Testing Properties Of Corrosive Lubricants

    DOEpatents

    Ohi, James; De La Cruz, Jose L.; Lacey, Paul I.

    2006-01-03

    A method of testing corrosive lubricating media using a wear testing apparatus without a mechanical seal. The wear testing apparatus and methods are effective for testing volatile corrosive lubricating media under pressure and at high temperatures.

  18. Testing galaxy quenching theories with scatter in the stellar-to-halo mass relation

    NASA Astrophysics Data System (ADS)

    Tinker, Jeremy L.

    2017-05-01

    We use the scatter in the stellar-to-halo mass relation to constrain galaxy evolution models. If the efficiency of converting accreted baryons into stars varies with time, haloes of the same present-day mass but different formation histories will have different z = 0 galaxy stellar mass. This is one of the sources of scatter in stellar mass at fixed halo mass, σlog M*. For massive haloes that undergo rapid quenching of star formation at z ˜ 2, different mechanisms that trigger this quenching yield different values of σlog M*. We use this framework to test various models in which quenching begins after a galaxy crosses a threshold in one of the following physical quantities: redshift, halo mass, stellar mass and stellar-to-halo mass ratio. Our model is highly idealized, with other sources of scatter likely to arise as more physics is included. Thus, our test is whether a model can produce scatter lower than observational bounds, leaving room for other sources. Recent measurements find σlog M* = 0.16 dex for 1011 M⊙ galaxies. Under the assumption that the threshold is constant with time, such a low value of σlog M* rules out all of these models with the exception of quenching by a stellar mass threshold. Most physical quantities, such as metallicity, will increase scatter if they are uncorrelated with halo formation history. Thus, to decrease the scatter of a given model, galaxy properties would correlate tightly with formation history, creating testable predictions for their clustering. Understanding why σlog M* is so small may be key to understanding the physics of galaxy formation.

  19. Experimental study on the mechanical properties of simulated columnar jointed rock masses

    NASA Astrophysics Data System (ADS)

    Xiao, Wei-min; Deng, Rong-gui; Zhong, Zhi-bin; Fu, Xiao-min; Wang, Cong-yan

    2015-02-01

    Columnar jointed rock mass is a kind of structural rock mass commonly encountered in igneous rocks. Due to the effects of columnar joint networks, anisotropy is the typical mechanical property of columnar jointed rock mass, i.e. deformation and strength varying with loading direction. Correct understanding of the mechanical anisotropy of columnar jointed rock mass is a key problem that should be solved for demonstration and design of large scale rock mass projects such as dams and underground cavern excavations constructed in it. Plaster simulated columnar jointed rock mass specimens at dip angles varying from 0° to 90° with respect to the axial stress were tested under uniaxial compression conditions to investigate the mechanical anisotropy and failure modes. Based on analyses of experimental results, it was found that the strength and deformation of columnar jointed rock masses had pronounced ‘U-shaped’ anisotropy. In the anisotropic curves, the maximum and minimum values occurred at β = 90° and β = 45°, respectively. It was also shown that the lateral strain ratio was relatively high, especially when the dip angle was close to (45° - φj/2), where φj was the joint friction angle. An empirical expression was adopted to predict the ‘U-shaped’ anisotropy of deformation and strength and the predicted anisotropic curves agreed reasonably well with experimental data. Furthermore, four types of failure modes were summarized based on experimental results and corresponding mechanisms were also discussed.

  20. The direct measurement of structural mass, stiffness and damping properties

    NASA Astrophysics Data System (ADS)

    Lee, H. G.; Dobson, B. J.

    1991-02-01

    A method is described for directly evaluating the spatial properties (i.e., mass, stiffness and damping) of a structure from experimentally measured frequency response data. The resulting structural model can be compared directly with an equivalent finite element idealization. The effects of model reduction, such as the Guyan method, which can be employed to ensure that the experimental and theoretical models contain comparable degrees of freedom, are discussed. It is shown that it is possible to detect regions within the structure at which differences exist between the experimental and theoretical models. Further, it is demonstrated that the resulting experimentally derived models can be used to predict the effects of structural modifications upon the frequency response behaviour of the structure.

  1. Atom Interferometry in the Presence of an External Test Mass

    SciTech Connect

    Dubetsky, Boris; Libby, Stephen; Berman, Paul

    2016-04-21

    The influence of an external test mass on the phase of the signal of an atom interferometer is studied theoretically. Using traditional techniques in atom optics based on the density matrix equations in the Wigner representation, we are able to extract the various contributions to the phase of the signal associated with the classical motion of the atoms, the quantum correction to this motion resulting from atomic recoil that is produced when the atoms interact with Raman field pulses and quantum corrections to the atomic motion that occur in the time between the Raman field pulses. Thus, by increasing the effective wave vector associated with the Raman field pulses using modified field parameters, we can increase the sensitivity of the signal to the point where such quantum corrections can be measured. Furthermore, the expressions that are derived can be evaluated numerically to isolate the contribution to the signal from an external test mass. The regions of validity of the exact and approximate expressions are determined.

  2. Atom Interferometry in the Presence of an External Test Mass

    DOE PAGES

    Dubetsky, Boris; Libby, Stephen; Berman, Paul

    2016-04-21

    The influence of an external test mass on the phase of the signal of an atom interferometer is studied theoretically. Using traditional techniques in atom optics based on the density matrix equations in the Wigner representation, we are able to extract the various contributions to the phase of the signal associated with the classical motion of the atoms, the quantum correction to this motion resulting from atomic recoil that is produced when the atoms interact with Raman field pulses and quantum corrections to the atomic motion that occur in the time between the Raman field pulses. Thus, by increasing themore » effective wave vector associated with the Raman field pulses using modified field parameters, we can increase the sensitivity of the signal to the point where such quantum corrections can be measured. Furthermore, the expressions that are derived can be evaluated numerically to isolate the contribution to the signal from an external test mass. The regions of validity of the exact and approximate expressions are determined.« less

  3. Thermophysical Property Testing Using Transient Techniques.

    DTIC Science & Technology

    1984-06-29

    Indiana or T1..* * !i!II~~iiiiI~i!IsiIIIui 103 un! - ~ ~- ."--.... THERMOPHYSICAL PROPERTIES RESEARCH LABORATORY School of Mechanical Engineering...diffusivity of mixtures of oxidizer plus binder and comparison to the results of computations based on the constituent properties . In order to accomplish...Temperatures- High Pressures, June 1984. 6. "Measurement of Thermal Transport Properties of Selected Solid Rocket Propellant Components", Stark, J.A., Master

  4. 21 CFR 866.6050 - Ovarian adnexal mass assessment score test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Ovarian adnexal mass assessment score test system... immunological Test Systems § 866.6050 Ovarian adnexal mass assessment score test system. (a) Identification. An ovarian/adnexal mass assessment test system is a device that measures one or more proteins in serum or...

  5. 21 CFR 866.6050 - Ovarian adnexal mass assessment score test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Ovarian adnexal mass assessment score test system... immunological Test Systems § 866.6050 Ovarian adnexal mass assessment score test system. (a) Identification. An ovarian/adnexal mass assessment test system is a device that measures one or more proteins in serum or...

  6. 21 CFR 866.6050 - Ovarian adnexal mass assessment score test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Ovarian adnexal mass assessment score test system... immunological Test Systems § 866.6050 Ovarian adnexal mass assessment score test system. (a) Identification. An ovarian/adnexal mass assessment test system is a device that measures one or more proteins in serum or...

  7. Higgs mass from D-terms: a litmus test

    NASA Astrophysics Data System (ADS)

    Cheung, Clifford; Roberts, Hannes L.

    2013-12-01

    We explore supersymmetric theories in which the Higgs mass is boosted by the non-decoupling D-terms of an extended U(1) X gauge symmetry, defined here to be a general linear combination of hypercharge, baryon number, and lepton number. Crucially, the gauge coupling, g X , is bounded from below to accommodate the Higgs mass, while the quarks and leptons are required by gauge invariance to carry non-zero charge under U(1) X . This induces an irreducible rate, σBR, for pp → X → ℓℓ relevant to existing and future resonance searches, and gives rise to higher dimension operators that are stringently constrained by precision electroweak measurements. Combined, these bounds define a maximally allowed region in the space of observables, ( σBR, m X ), outside of which is excluded by naturalness and experimental limits. If natural supersymmetry utilizes non-decoupling D-terms, then the associated X boson can only be observed within this window, providing a model independent `litmus test' for this broad class of scenarios at the LHC. Comparing limits, we find that current LHC results only exclude regions in parameter space which were already disfavored by precision electroweak data.

  8. Some attributes of a language for property-based testing.

    SciTech Connect

    Neagoe, Vicentiu; Bishop, Matt

    2004-11-01

    Property-based testing is a testing technique that evaluates executions of a program. The method checks that specifications, called properties, hold throughout the execution of the program. TASpec is a language used to specify these properties. This paper compares some attributes of the language with the specification patterns used for model-checking languages, and then presents some descriptions of properties that can be used to detect common security flaws in programs. This report describes the results of a one year research project at the University of California, Davis, which was funded by a University Collaboration LDRD entitled ''Property-based Testing for Cyber Security Assurance''.

  9. Human Mars Mission: Weights and Mass Properties. Pt. 1

    NASA Technical Reports Server (NTRS)

    Brothers, Bobby

    1999-01-01

    This paper presents a final report on The Human Mars Mission Weights and Measures. The topics included in this report are: 1) Trans-Earth Injection Storage Human Mars Mission (HMM) Chemical Design Reference Mission (DRM) v4.0a Weight Breakout; 2) Ascent Stage HMM Chemical DRM v4.0a Weight Breakout; 3) Descent Stages HMM Chemical DRM v4.0a Weight Breakout; 4) Trans-Mars Injection Stages HMM Chemical DRM v4.0a Weight Breakout; 5) Trans-Earth Injection Stage HMM Solar Electric Propulsion (SEP) DRM v4.0a Weight Breakout; 6) Ascent Stage HMM SEP DRM v4.0a Weight Breakout; 7) Descent Stages HMM SEP DRM v4.0a Weight Breakout; 8) Trans-Mars Injection Stages HMM SEP DRM v4.0a Weight Breakout; 9) Crew Taxi Stage HMM SEP DRM v4.0 Weight Breakout; 10)Trans-Earth Injection Stage HMM Nuclear DRM v4.0a Weight Breakout; 11) Ascent Stage HMM Nuclear DRM v4.0a Weight Breakout; 12) Descent Stages HMM Nuclear DRM v4.0a Weight Breakout; 13) Trans-Mars Injection Stages HMM Nuclear DRM v4.0a Weight Breakout; and 14) HMM Mass Properties Coordinate System.

  10. RSRM-9 (360L009): Ballistics mass properties

    NASA Technical Reports Server (NTRS)

    Drendel, Albert S.; Richards, M. C.

    1990-01-01

    The propulsion performance and reconstructed mass properties data from Thiokol's RSRM-9 motors which were assigned to the STS-36 launch are presented. The SRM propellant, TP-H1148, is a composite type solid propellant, formulated of polybutadiene acrylic acid acryonitrile terpolymer binder (PBAN), epoxy curing agent, ammonium perchlorate oxidizer and aluminum powder fuel. A small amount of burning rate catalyst (iron oxide) was added to achieve the desired propellant burn rate. The propellant evaluation and raw material information for the RSRM-9 are included. The propellant grain design consists of four segments. There is a forward segment with an eleven point star with a transition into a tapered circular perforated (CP) configuration. There are two center segments that result in a double tapered CP configuration and an aft segment with a triple taper CP configuration and a cutout for the partially submerged nozzle. The ballistic performance presented is based on the Operational Flight Instrumentation (OFI) 12.5 sample per second pressure data for the steady state and tail off portion of the pressure trace. No high sample rate pressure gauges, Development Flight Instrumentation (DFI), were used on this flight and therefore no ignition data is presented.

  11. On-ground testing of the role of adhesion in the LISA-Pathfinder test mass injection phase

    NASA Astrophysics Data System (ADS)

    Bortoluzzi, D.; Zanoni, C.; Conklin, J. W.

    2017-05-01

    Many space missions share the need to fly a free-falling body inside the spacecraft, as a reference for navigation and/or as a probe for the local gravitational field. When a mechanism is required to cage such an object during the launch phase, the need arises to release it to free-fall once the operational phase must be initiated in orbit. The criticality of this phase increases when the mechanical interfaces between the body and the mechanism are affected by adhesion and the actuation authority of the control system on the free-falling body is limited. Both conditions are realized in the LISA Pathfinder mission, which aims at injecting a gold-coated 2 kg cubic test mass into a nearly perfect geodesic trajectory to demonstrate the readiness of the developed technology for in-space gravity wave detection. The criticality of adhesion is widely recognized in space technology, because it can affect and jeopardize the functionality of mechanisms, when arising between moving parts. In the LISA Pathfinder case, metallic adhesion potentially plays a relevant role, mainly for two reasons. First, thanks to its properties (ductility, high surface energy) the gold coating on the proof mass easily produces cold weldings, especially in vacuum conditions. Second, the detachment of the proof mass from the releasing device occurs abruptly and a relevant influence of the separation velocity is expected on the strength of the welding. This can produce an excessive velocity of the proof mass at the retraction of the releasing device for the following capture and centring phase on behalf of the control system. A testing activity is performed to characterize the dynamic behaviour of the adhesive bonds between the proof mass and the releasing device, which can be used to predict their contribution on the residual velocity of the proof mass after in-flight release. The study of such a dynamic phenomenon sets some challenging requirements on the measurement technique, both on the

  12. Psychometric Properties of the Eating Attitudes Test

    ERIC Educational Resources Information Center

    Ocker, Liette B.; Lam, Eddie T. C.; Jensen, Barbara E.; Zhang, James J.

    2007-01-01

    The study was designed to examine the construct validity and internal consistency reliability of the Eating Attitudes Test (EAT) using a confirmatory factor analysis (CFA). Two widely adopted EAT models were tested: three-factor (Dieting, Bulimia and Food Preoccupation, and Oral Control) with 26 items (Garner, Olmsted, Bohr, & Garfinkel, 1982),…

  13. Psychometric Properties of the Eating Attitudes Test

    ERIC Educational Resources Information Center

    Ocker, Liette B.; Lam, Eddie T. C.; Jensen, Barbara E.; Zhang, James J.

    2007-01-01

    The study was designed to examine the construct validity and internal consistency reliability of the Eating Attitudes Test (EAT) using a confirmatory factor analysis (CFA). Two widely adopted EAT models were tested: three-factor (Dieting, Bulimia and Food Preoccupation, and Oral Control) with 26 items (Garner, Olmsted, Bohr, & Garfinkel, 1982),…

  14. WHAT DO DARK MATTER HALO PROPERTIES TELL US ABOUT THEIR MASS ASSEMBLY HISTORIES?

    SciTech Connect

    Wong, Anson W. C.; Taylor, James E. E-mail: taylor@uwaterloo.ca

    2012-09-20

    Individual dark matter halos in cosmological simulations vary widely in their detailed structural properties, properties such as concentration, shape, spin, and degree of internal relaxation. Recent non-parametric (principal component) analyses suggest that a few principal components explain a large fraction of the scatter in these structural properties. The main principal component is closely aligned with concentration, which in turn is known to be related to the mass accretion history (MAH) of the halo, as described by its merger tree. Here, we examine more generally the connection between the MAH and structural parameters. The space of mass accretion histories has principal components of its own. The strongest, accounting for almost 60% of the scatter between individual histories, can be interpreted as the age of the system. We give an analytic fit for this first component, which provides a rigorous way of defining the dynamical age of a halo. The second strongest component, representing acceleration or deceleration of growth at late times, accounts for 25% of the scatter. Relating structural parameters to formation history, we find that concentration correlates strongly with the early history of the halo, while shape and degree of relaxation or dynamical equilibrium correlate with the later history. We examine the inferences about formation history that can be drawn by splitting halos into sub-samples based on observable properties such as concentration and shape. Applications include the definition young and old samples of galaxy clusters in a quantitative way, or empirical tests of environmental processing rates in clusters.

  15. Tandem configuration of differential mobility and centrifugal particle mass analysers for investigating aerosol hygroscopic properties

    NASA Astrophysics Data System (ADS)

    Vlasenko, Sergey S.; Su, Hang; Pöschl, Ulrich; Andreae, Meinrat O.; Mikhailov, Eugene F.

    2017-03-01

    A tandem arrangement of Differential Mobility Analyser and Humidified Centrifugal Particle Mass Analyser (DMA-HCPMA) was developed to measure the deliquescence and efflorescence thresholds and the water uptake of submicron particles over the relative humidity (RH) range from 10 to 95 %. The hygroscopic growth curves obtained for ammonium sulfate and sodium chloride test aerosols are consistent with thermodynamic model predictions and literature data. The DMA-HCPMA system was applied to measure the hygroscopic properties of urban aerosol particles, and the kappa mass interaction model (KIM) was used to characterize and parameterize the concentration-dependent water uptake observed in the 50-95 % RH range. For DMA-selected 160 nm dry particles (modal mass of 3.5 fg), we obtained a volume-based hygroscopicity parameter, κv ≈ 0.2, which is consistent with literature data for freshly emitted urban aerosols.Overall, our results show that the DMA-HCPMA system can be used to measure size-resolved mass growth factors of atmospheric aerosol particles upon hydration and dehydration up to 95 % RH. Direct measurements of particle mass avoid the typical complications associated with the commonly used mobility-diameter-based HTDMA technique (mainly due to poorly defined or unknown morphology and density).

  16. System for testing properties of a network

    DOEpatents

    Rawle, Michael; Bartholomew, David B.; Soares, Marshall A.

    2009-06-16

    A method for identifying properties of a downhole electromagnetic network in a downhole tool sting, including the step of providing an electromagnetic path intermediate a first location and a second location on the electromagnetic network. The method further includes the step of providing a receiver at the second location. The receiver includes a known reference. The analog signal includes a set amplitude, a set range of frequencies, and a set rate of change between the frequencies. The method further includes the steps of sending the analog signal, and passively modifying the signal. The analog signal is sent from the first location through the electromagnetic path, and the signal is modified by the properties of the electromagnetic path. The method further includes the step of receiving a modified signal at the second location and comparing the known reference to the modified signal.

  17. Psychometric properties of the Halstead Category Test.

    PubMed

    Lopez, M N; Charter, R A; Newman, R J

    2000-05-01

    Using the Kuder-Richardson formula 20 (KR-20) corrected for item difficulty, the internal consistency reliability of the Halstead Category Test (HCT) was calculated for a sample (N = 398) of normal patients and volunteers, diffusely brain-damaged patients, and undiagnosed patients sent for neuropsychological assessment. The HCT Total Score reliability was.9716 and the subtest reliabilities ranged from.4587 to.9590. An item analysis found that most of the test items, except for those from Subtests I and II, were within established criteria for item difficulty and the discrimination index.

  18. Correlation of elastomer material properties from small specimen tests and scale-size bearing tests

    SciTech Connect

    Kulak, R.F.; Hughes, T.H.

    1994-06-01

    Tests were performed on small-size elastomer specimens and scale-size laminated elastomeric bearings to correlate the material properties in shear between the two types of tests. An objective of the tests was to see how well the material properties that were determined from specimen tests could predict the response of scale-size laminated elastomeric bearings. Another objective was to compare the results of specimen test and scale-size bearing test conducted by different testing organizations. A comparison between the test results from different organizations on small specimens showed very good agreement. In contrast, the correlation of scale-size bearing tests showed differences in bearing stiffness.

  19. A Wald test with enhanced selectivity properties in homogeneous environments

    NASA Astrophysics Data System (ADS)

    Liu, Weijian; Xie, Wenchong; Wang, Yongliang

    2013-12-01

    A Wald test with enhanced selectivity capabilities is proposed in homogeneous environments. At the design stage, we assume that the cell under test contains a noise-like interferer in addition to colored noise and possible signal of interest. We show that the Wald test is equivalent to a recently proposed Rao test. We also observe that this Rao/Wald test possesses constant false alarm rate property in homogeneous environments.

  20. Study of solid rocket motors for a space shuttle booster. Volume 4: Mass properties report

    NASA Technical Reports Server (NTRS)

    Vonderesch, A. H.

    1972-01-01

    Mass properties data for the 156 inch diameter, parallel burn, solid propellant rocket engine for the space shuttle booster are presented. Design ground rules and assumptions applicable to generation of the mass properties data are described, together with pertinent data sources.

  1. Oligomers Modulate Interfibril Branching and Mass Transport Properties of Collagen Matrices

    PubMed Central

    Whittington, Catherine F.; Brandner, Eric; Teo, Ka Yaw; Han, Bumsoo; Nauman, Eric; Voytik-Harbin, Sherry L.

    2013-01-01

    Mass transport within collagen-based matrices is critical to tissue development, repair, and pathogenesis as well as the design of next generation tissue engineering strategies. This work shows how collagen precursors, specified by intermolecular cross-link composition, provide independent control of collagen matrix mechanical and transport properties. Collagen matrices were prepared from tissue-extracted monomers or oligomers. Viscoelastic behavior was measured in oscillatory shear and unconfined compression. Matrix permeability and diffusivity were measured using gravity-driven permeametry and integrated optical imaging, respectively. Both collagen types showed an increase in stiffness and permeability hindrance with increasing collagen concentration (fibril density); however, different physical property-concentration relationships were noted. Diffusivity wasn’t affected by concentration for either collagen type over the range tested. In general, oligomer matrices exhibited a substantial increase in stiffness and only a modest decrease in transport properties when compared to monomer matrices prepared at the same concentration. The observed differences in viscoelastic and transport properties were largely attributed to increased levels of interfibril branching within oligomer matrices. The ability to relate physical properties to relevant microstructure parameters, including fibril density and interfibril branching, is expected to advance the understanding of cell-matrix signaling as well as facilitate model-based prediction and design of matrix-based therapeutic strategies. PMID:23842082

  2. Estimating mass properties of dinosaurs using laser imaging and 3D computer modelling.

    PubMed

    Bates, Karl T; Manning, Phillip L; Hodgetts, David; Sellers, William I

    2009-01-01

    biomechanical assessments of extinct taxa should be preceded by a detailed investigation of the plausible range of mass properties, in which sensitivity analyses are used to identify a suite of possible values to be tested as inputs in analytical models.

  3. Estimating Mass Properties of Dinosaurs Using Laser Imaging and 3D Computer Modelling

    PubMed Central

    Bates, Karl T.; Manning, Phillip L.; Hodgetts, David; Sellers, William I.

    2009-01-01

    biomechanical assessments of extinct taxa should be preceded by a detailed investigation of the plausible range of mass properties, in which sensitivity analyses are used to identify a suite of possible values to be tested as inputs in analytical models. PMID:19225569

  4. Concrete Property and Radionuclide Migration Tests

    SciTech Connect

    Wellman, Dawn M.; Mattigod, Shas V.; Powers, Laura; Parker, Kent E.; Clayton, Libby N.; Wood, Marcus I.

    2008-10-01

    The Waste Management Project provides safe, compliant, and cost-effective waste management services for the Hanford Site and the DOE Complex. Part of theses services includes safe disposal of LLW and MLLW at the Hanford Low-Level Waste Burial Grounds (LLBG) in accordance with the requirements listed in DOE Order 435.1, Radioactive Waste Management. To partially satisfy these requirements, a Performance Assessment (PA) analyses were completed and approved. DOE Order 435.1 also requires that continuing data collection be conducted to enhance confidence in the critical assumptions used in these analyses to characterize the operational features of the disposal facility that are relied upon to satisfy the performance objectives identified in the Order. One critical assumption is that concrete will frequently be used as waste form or container material to control and minimize the release of radionuclide constituents in waste into the surrounding environment. Data was collected to (1) quantify radionuclide migration through concrete materials similar to those used to encapsulate waste in the LLBG, (2) measure the properties of the concrete materials, especially those likely to influence radionuclide migration, and (3) quantify the stability of U-bearing solid phases of limited solubility in concrete.

  5. Expendable second stage reusable space shuttle booster. Volume 4: Detail mass properties data

    NASA Technical Reports Server (NTRS)

    1971-01-01

    Mass properties data are presented to describe the characteristics of an expendable second stage with a reusable space shuttle booster. The final mass characteristics of the vehicle configurations for three specified payloads are presented in terms of weight, center of gravity, and mass moments of inertia. Three basic subjects are the integrated vehicle system, the expendable second stage, and the booster modifications.

  6. Tests of timing properties of silicon photomultipliers

    SciTech Connect

    Ronzhin, A.; Albrow, M.; Byrum, K.; Demarteau, M.; Los, S.; May, E.; Ramberg, A.; Va'vra, J.; Zatserklyaniy, A.; /Puerto Rico U., Mayaguez

    2010-03-01

    Timing measurements of Silicon Photomultipliers (SiPM) [1] and [2] at the picosecond level were performed at Fermilab. The core timing resolution of the electronic measurement technique is approximately 2 ps. The single photoelectron time resolution (SPTR) was measured for the signals coming from the SiPM's. A SPTR of about one hundred picoseconds was obtained for SiPM's illuminated by laser pulses. The dependence of the SPTR on applied bias voltage and on the wavelength of the light was measured. A simple model is proposed to explain the difference in the SPTR for blue and red light. A time of flight system based on the SiPM's, with quartz Cherenkov radiators, was tested in a proton beam at Fermilab. The time resolution obtained is 35 ps per SiPM. Finally, requirements for the SiPM's temperature and bias voltage stability to maintain the time resolution are discussed.

  7. Carotenoids in bird testes: links to body carotenoid supplies, plumage coloration, body mass and testes mass in house finches (Carpodacus mexicanus).

    PubMed

    Rowe, Melissah; Tourville, Elizabeth A; McGraw, Kevin J

    2012-01-01

    Carotenoid pigments can be allocated to different parts of the body to serve specific functions. In contrast to other body tissues, studies of carotenoid resources in the testes of animals are relatively scarce. We used high-performance liquid chromatography to determine the types and concentrations of carotenoids in the testes of house finches (Carpodacus mexicanus). Additionally, we examined the relationships between testes carotenoid concentrations and carotenoid pools in other body tissues, as well as body mass, testes mass and plumage coloration. We detected low concentrations of several carotenoids - lutein (the predominant carotenoid), zeaxanthin, anhydrolutein, β-cryptoxanthin, β-carotene and an unknown carotene - in the testes of wild house finches. We also found that testes lutein levels were significantly and positively associated with circulating lutein levels, while the concentration of zeaxanthin in testes was positively associated with zeaxanthin levels in liver, though in this instance the relationship was much weaker and only marginally significant. Furthermore, lutein levels in testes were significantly negatively associated with testes mass. Finally, plumage coloration was not associated with either the concentration of carotenoids in the testes or relative testes mass. These results suggest that testes carotenoids are reflective of the pool of circulating carotenoids in house finches, and that plumage coloration is unlikely to signal either the carotenoid content of testes tissue or a male's capacity for sperm production. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. The Identification of Radex Properties in Objective Test Items.

    ERIC Educational Resources Information Center

    Seddon, G. M.; And Others

    1981-01-01

    In a Monte Carlo simulation, a methodology was developed to investigate the existence of radex properties among objective test items. In an experiment with items covering four categories of Bloom's cognitive domain taxonomy, the items did not have the factorial properties of a radex with four levels of complexity. (Author/BW)

  9. Means for ultrasonic testing when material properties vary

    DOEpatents

    Beller, Laurence S.

    1979-01-01

    A device is provided for maintaining constant sensitivity in an ultrasonic testing device, despite varying attenuation due to the properties of the material being tested. The device includes a sensor transducer for transmitting and receiving a test signal and a monitor transducer positioned so as to receive ultrasonic energy transmitted through the material to be tested. The received signal of the monitor transducer is utilized in analyzing data obtained from the sensor transducer.

  10. Mass loss from red giants: its development, dust properties, and dependence on the stellar parameters mass, luminosity and metallicity

    NASA Astrophysics Data System (ADS)

    Wood, Peter; Blommaert, Joris; Cioni, Maria-Rosa; Feast, Michael; Groenewegen, Martin; Habing, Harm; Hony, Sacha; Loup, Cecile; Matsuura, Mikako; Omont, Alain; Waters, Rens; Whitelock, Patricia; Zijlstra, Albert; van Loon, Jacco

    2004-09-01

    We wish to obtain low resolution IRS spectra of highly evolved, low and intermediate mass stars in the Large and Small Magellanic Clouds. Our sample of stars consists of asymptotic giant branch (AGB) stars in both the general field of the Clouds and in clusters, and it complements the GTO samples of Houck and Kemper. The stars range from lower luminosity stars with small mass loss rates in the two clusters NGC419 and NGC1978 to dust-enshrouded stars in the "superwind" phase. The stars have been studied from the ground (mostly by members of this team) in order to determine spectral types, pulsation periods and amplitudes, and optical and near-infrared fluxes. Our aim is to use the IRS spectra to empirically determine the dependence of mass loss rate on stellar mass, luminosity, pulsation period and amplitude, and metallicity. We will also examine the dust properties as a function of mass loss rate, luminosity and photospheric chemical type. The AGB mass loss law resulting from this study will allow accurate AGB stellar evolution calculations to be made, meaning that reliable estimates can be made of the total mass loss from an AGB star, the stellar remnant mass, and the amounts of nucleosynthetic products ejected. Since the rate of mass return to, and enrichment of, the interstellar medium by low and intermediate mass stars depends critically on the mass loss rate and surface enrichment during the AGB phase, an accurate mass loss law will greatly enhance the reliability of galactic enrichment models. Our total request is for 31.4 hours.

  11. Oligomers modulate interfibril branching and mass transport properties of collagen matrices.

    PubMed

    Whittington, Catherine F; Brandner, Eric; Teo, Ka Yaw; Han, Bumsoo; Nauman, Eric; Voytik-Harbin, Sherry L

    2013-10-01

    Mass transport within collagen-based matrices is critical to tissue development, repair, and pathogenesis, as well as the design of next-generation tissue engineering strategies. This work shows how collagen precursors, specified by intermolecular cross-link composition, provide independent control of collagen matrix mechanical and transport properties. Collagen matrices were prepared from tissue-extracted monomers or oligomers. Viscoelastic behavior was measured in oscillatory shear and unconfined compression. Matrix permeability and diffusivity were measured using gravity-driven permeametry and integrated optical imaging, respectively. Both collagen types showed an increase in stiffness and permeability hindrance with increasing collagen concentration (fibril density); however, different physical property–concentration relationships were noted. Diffusivity was not affected by concentration for either collagen type over the range tested. In general, oligomer matrices exhibited a substantial increase in stiffness and only a modest decrease in transport properties when compared with monomer matrices prepared at the same concentration. The observed differences in viscoelastic and transport properties were largely attributed to increased levels of interfibril branching within oligomer matrices. The ability to relate physical properties to relevant microstructure parameters, including fibril density and interfibril branching, is expected to advance the understanding of cell–matrix signaling, as well as facilitate model-based prediction and design of matrix-based therapeutic strategies.

  12. Large-scale inhomogeneity in sapphire test masses revealed by Rayleigh scattering imaging

    NASA Astrophysics Data System (ADS)

    Yan, Zewu; Ju, Li; Eon, François; Gras, Slawomir; Zhao, Chunnong; Jacob, John; Blair, David G.

    2004-03-01

    Rayleigh scattering in test masses can introduce noise and reduce the sensitivity of laser interferometric gravitational wave detectors. In this paper, we present laser Rayleigh scattering imaging as a technique to investigate sapphire test masses. The system provides three-dimensional Rayleigh scattering mapping of entire test masses and quantitative evaluation of the Rayleigh scattering coefficient. Rayleigh scattering mapping of two sapphire samples reveals point defects as well as inhomogeneous structures in the samples. We present results showing significant non-uniform scattering within two 4.5 kg sapphire test masses manufactured by the heat exchanger method.

  13. Massed Group Desensitization in Reduction of Test-Anxiety

    ERIC Educational Resources Information Center

    Dawley, Harold H., Jr.; Wenrich, W. W.

    1973-01-01

    The results of this study of two groups of nursing students, one administered desensitization sessions, the other not, agree with earlier studies which indicate that massed group desensitization is an efficient and efficacious procedure for the reduction of anxiety-based disorders. (Author/KM)

  14. Tuning The Properties of Quantum Dots Via The Effective Mass

    NASA Astrophysics Data System (ADS)

    Singh, R. A.; Sinha, Abhinav; Pathak, Praveen

    2011-07-01

    In the present work we revisit effective mass theory (EMT) for a semiconductor quantum dot (QD) and employ the BenDaniel-Duke (BDD) boundary condition. In effective mass theory mass mi inside the dot of radius R is different from the mass mo outside the dot. That gives us a crucial factor in determining the electronic spectrum namely β = mi/m0. We show both by numerical calculations and asymptotic analysis that the ground state energy and the surface charge density, ρ(r) can be large. We also show that the dependence of the ground state energy on the radius of the well is infraquadratic. We demonstrate that the significance of BDD condition is pronounced at large R. We also study the dependence of excited state on the radius as well as the difference between energy states. Both exhibit an infra quadratic behavior with radius. The energy difference is important in study of absorption and emission spectra. We find that the BDD condition substantially alters the energy difference. Hence the interpretation of experimental result may need to be reexamined.

  15. Tuning The Properties of Quantum Dots Via The Effective Mass

    SciTech Connect

    Singh, R. A.; Sinha, Abhinav; Pathak, Praveen

    2011-07-15

    In the present work we revisit effective mass theory (EMT) for a semiconductor quantum dot (QD) and employ the BenDaniel-Duke (BDD) boundary condition. In effective mass theory mass m{sub i} inside the dot of radius R is different from the mass m{sub o} outside the dot. That gives us a crucial factor in determining the electronic spectrum namely {beta} = m{sub i}/m{sub 0}. We show both by numerical calculations and asymptotic analysis that the ground state energy and the surface charge density, {rho}(r) can be large. We also show that the dependence of the ground state energy on the radius of the well is infraquadratic. We demonstrate that the significance of BDD condition is pronounced at large R. We also study the dependence of excited state on the radius as well as the difference between energy states. Both exhibit an infra quadratic behavior with radius. The energy difference is important in study of absorption and emission spectra. We find that the BDD condition substantially alters the energy difference. Hence the interpretation of experimental result may need to be reexamined.

  16. PROPERTIES IMPORTANT TO MIXING FOR WTP LARGE SCALE INTEGRATED TESTING

    SciTech Connect

    Koopman, D.; Martino, C.; Poirier, M.

    2012-04-26

    Large Scale Integrated Testing (LSIT) is being planned by Bechtel National, Inc. to address uncertainties in the full scale mixing performance of the Hanford Waste Treatment and Immobilization Plant (WTP). Testing will use simulated waste rather than actual Hanford waste. Therefore, the use of suitable simulants is critical to achieving the goals of the test program. External review boards have raised questions regarding the overall representativeness of simulants used in previous mixing tests. Accordingly, WTP requested the Savannah River National Laboratory (SRNL) to assist with development of simulants for use in LSIT. Among the first tasks assigned to SRNL was to develop a list of waste properties that matter to pulse-jet mixer (PJM) mixing of WTP tanks. This report satisfies Commitment 5.2.3.1 of the Department of Energy Implementation Plan for Defense Nuclear Facilities Safety Board Recommendation 2010-2: physical properties important to mixing and scaling. In support of waste simulant development, the following two objectives are the focus of this report: (1) Assess physical and chemical properties important to the testing and development of mixing scaling relationships; (2) Identify the governing properties and associated ranges for LSIT to achieve the Newtonian and non-Newtonian test objectives. This includes the properties to support testing of sampling and heel management systems. The test objectives for LSIT relate to transfer and pump out of solid particles, prototypic integrated operations, sparger operation, PJM controllability, vessel level/density measurement accuracy, sampling, heel management, PJM restart, design and safety margin, Computational Fluid Dynamics (CFD) Verification and Validation (V and V) and comparison, performance testing and scaling, and high temperature operation. The slurry properties that are most important to Performance Testing and Scaling depend on the test objective and rheological classification of the slurry (i

  17. Fluid and porous media property effects on dense nonaqueous phase liquid migration and contaminant mass flux.

    PubMed

    Totten, C T; Annable, M D; Jawitz, J W; Delfinot, J J

    2007-03-01

    The effects of fluid and porous media properties on dense nonaqueous phase liquid (DNAPL) migration and associated contaminant mass flux generation were evaluated. Relationships between DNAPL mass and solute mass flux were generated by measuring steady-state mass flux following stepwise injection of perchloroethylene (PCE) into flow chambers packed with homogeneous porous media. The effects of fluid properties including density and interfacial tension (IFT), and media properties including grain size and wettability were evaluated by varying the density contrast and interfacial tension properties between PCE and water, and by varying the porous media mean grain diameter and wettability characteristics. Contaminant mass flux was found to increase as grain size decreased, suggesting enhanced lateral and vertical DNAPL spreading with higher fluid entry pressure. Mass flux showed a slight increase as the DNAPL approached neutral buoyancy, likely due to enhanced vertical spreading above the injection point. DNAPL spatial distribution and contaminant mass flux were only minimally affected by IFT and by intermediate-level wettability changes, but were dramatically affected by wettability reversal. The relationship between DNAPL loading and flux generation became more linear as grain size decreased and density contrast between fluids decreased. These results imply that capillary flow characteristics of the porous media and fluid properties will control mass flux generation from source zones.

  18. Initial experimental test of a helicon plasma based mass filter

    SciTech Connect

    Gueroult, R.; Evans, E. S.; Zweben, S. J.; Fisch, N. J.; Levinton, F.

    2016-05-12

    High throughput plasma mass separation requires rotation control in a high density multi-species plasmas. A preliminary mass separation device based on a helicon plasma operating in gas mixtures and featuring concentric biasable ring electrodes is introduced. Plasma profile shows strong response to electrode biasing. In light of floating potential measurements, the density response is interpreted as the consequence of a reshaping of the radial electric field in the plasma. This field can be made confining or de-confining depending on the imposed potential at the electrodes, in a way which is consistent with single particle orbit radial stability. In conclusion, concurrent spatially resolved spectroscopic measurements suggest ion separation, with heavy to light ion emission line ratio increasing with radius when a specific potential gradient is applied to the electrodes.

  19. Initial experimental test of a helicon plasma based mass filter

    SciTech Connect

    Gueroult, R.; Evans, E. S.; Zweben, S. J.; Fisch, N. J.; Levinton, F.

    2016-05-12

    High throughput plasma mass separation requires rotation control in a high density multi-species plasmas. A preliminary mass separation device based on a helicon plasma operating in gas mixtures and featuring concentric biasable ring electrodes is introduced. Plasma profile shows strong response to electrode biasing. In light of floating potential measurements, the density response is interpreted as the consequence of a reshaping of the radial electric field in the plasma. This field can be made confining or de-confining depending on the imposed potential at the electrodes, in a way which is consistent with single particle orbit radial stability. In conclusion, concurrent spatially resolved spectroscopic measurements suggest ion separation, with heavy to light ion emission line ratio increasing with radius when a specific potential gradient is applied to the electrodes.

  20. Initial experimental test of a helicon plasma based mass filter

    DOE PAGES

    Gueroult, R.; Evans, E. S.; Zweben, S. J.; ...

    2016-05-12

    High throughput plasma mass separation requires rotation control in a high density multi-species plasmas. A preliminary mass separation device based on a helicon plasma operating in gas mixtures and featuring concentric biasable ring electrodes is introduced. Plasma profile shows strong response to electrode biasing. In light of floating potential measurements, the density response is interpreted as the consequence of a reshaping of the radial electric field in the plasma. This field can be made confining or de-confining depending on the imposed potential at the electrodes, in a way which is consistent with single particle orbit radial stability. In conclusion, concurrentmore » spatially resolved spectroscopic measurements suggest ion separation, with heavy to light ion emission line ratio increasing with radius when a specific potential gradient is applied to the electrodes.« less

  1. Prediction of Mass Evaporation of During Measurements of Thermophysical Properties Using an Electrostatic Levitator

    NASA Astrophysics Data System (ADS)

    Lee, J.; Matson, D. M.

    2014-10-01

    This paper describes the prediction of mass evaporation of at% alloys during thermophysical property measurements using the electrostatic levitator at NASA Marshall Space Flight Center in Huntsville, AL. The final mass, final composition, and activity of individual component are considered in the calculation of mass evaporation. The predicted reduction in mass and variation in composition are validated with six ESL samples which underwent different thermal cycles. The predicted mass evaporation and composition shift show good agreement with experiments with the maximum relative errors of 4.8 % and 1.7 %, respectively.

  2. Determination of densified biomass mass properties using 3D laser scanning and image analysis

    USDA-ARS?s Scientific Manuscript database

    Biomass densification is viewed as the indispensable feedstock preprocessing operation for efficient transport, storage, material flow through machines, and handling activities. Accurate mass properties of densified biomass such as surface area, volume, and envelope density form fundamental data for...

  3. Testing the Injection of the LISA Pathfinder Test Mass into Geodesic Conditions

    NASA Astrophysics Data System (ADS)

    Zanoni, C.; Bortoluzzi, D.; Conklin, J. W.; Koker, I.; Marirrodriga, C. G.; Nellen, P. M.; Vitale, S.

    2013-09-01

    LISA Pathfinder is a technology demonstration mission aimed at testing the free-fall purity level of a reference mass (or test mass, TM). Such an object can be used as a geodesic tracker for the detection of gravitational waves and is the core of the Gravitational Reference Sensor (GRS). The low acceleration noise level pursued for the tracker sets tight design constraints on the GRS. Any non-gravitational force has to be reduced to the level of 10 fN in the measurement bandwidth (1-30 mHz).The TM is firmly constrained by the Caging and Venting Mechanism (CVM) during the spacecraft launch and is then handed over to the Grabbing Positioning and Release Mechanism (GPRM). This mechanism is designed to handle the TM during in-orbit operations and inject it into the geodesic trajectory (or free-fall condition) by means of a quick retraction of two release tips on two opposed sides of the TM. After these operations, the TM residual velocity must be below 5 μm/s, otherwise the GRS capacitive position control is not able to capture and centre the TM in its electrode housing. Due to this criticality, the requirement on the maximum release velocity is verified on-ground both by means of an experimental apparatus (the Transferred Momentum Measurement Facility, TMMF) and by means of simulations. The TMMF is specifically designed to assess the contribution of adhesion between TM and release tips to the total TM momentum. On top of this contribution, any deviation from a symmetrical action of the two opposed release mechanisms determines an extra transferred momentum. Great care must be taken to correlate the experimental results with the in-flight conditions, where a different actuator is used to perform the TM injection. The extrapolation of the experimental results to in-flight conditions and the Montecarlo simulation of the GPRM-TM combined dynamics show the presence of a 2.4 margin factor with respect to the 5 μm/s requirement.The on-ground measured and simulated

  4. Ecotoxicity testing of microplastics: Considering the heterogeneity of physicochemical properties.

    PubMed

    Lambert, Scott; Scherer, Christian; Wagner, Martin

    2017-05-01

    "Microplastic" is an umbrella term that covers many particle shapes, sizes, and polymer types, and as such the physical and chemical properties of environmental microplastics will differ from the primary microbeads commonly used for ecotoxicity testing. In the present article, we discuss the physical and chemical properties of microplastics that are potentially relevant to their ecotoxicity, including particle size, particle shape, crystallinity, surface chemistry, and polymer and additive composition. Overall, there is a need for a structured approach to the testing of different properties to identify which are the most relevant drivers of microplastic toxicity. In addition, the properties discussed will be influenced by and change depending on environmental conditions and degradation pathways. Future challenges include new technologies that will enter the plastic production cycle and the impact of these changes on the composition of environmental microplastics. Integr Environ Assess Manag 2017;13:470-475. © 2017 SETAC. © 2017 SETAC.

  5. Cyclic material properties tests supporting elastic-plastic analysis development

    SciTech Connect

    Hodge, S.C.; Minicucci, J.M.

    1996-11-01

    Correlation studies have shown that hardening models currently available in the ABAQUS finite element code (isotropic, kinematic) do not accurately capture the inelastic strain reversals that occur due to structural rebounding from a rapidly applied transient dynamic load. The purpose of the Cyclic Material properties Test program was to obtain response data for the first several cycles of inelastic strain reversal from a cyclic properties test. This data is needed to develop elastic-plastic analysis methods that can accurately predict strains and permanent sets in structures due to rapidly applied transient dynamic loading. Test specimens were cycled at inelastic strain levels typical of rapidly applied transient dynamic analyses (0.5% to 4.0%). In addition to the inelastic response data, cyclic material properties for high yield strength (80 ksi) steel were determined including a cyclic stress-strain curve for a stabilized specimen. Two test methods, the Incremental Step method and the Companion specimen Method, were sued to determine cyclic properties. The incrementally decreasing strain amplitudes in the first loading block of the Incremental Step method test is representative of the response of structures subjected to rapidly applied transient dynamic loads. The inelastic strain history data generated by this test program will be used to support development of a material model that can accurately predict inelastic material behavior including inelastic strain reversals. Additionally, this data can be used to verify material model enhancements to elastic-plastic finite element analysis codes.

  6. Testing General Relativity with Spherical Resonant Mass Detectors

    NASA Astrophysics Data System (ADS)

    Sylvester, Alex J.

    2015-08-01

    Gravitational waves in f(R) gravity excite monopole and m = 0+/-2 quadrupole resonance modes of a spherical detector. This document reviews the basic ideas of general relativity and gravitational waves, and then applies those concepts to an f( R) gravitational wave. The acoustic response of a GW incident with a spherical detector is reviewed in detail, and the absorption cross section for an f(R) GW impinging on the spherical detector is calculated. Minimum detectable scalar wave amplitudes are explored for the Mario Schenberg detector. The mass of the scalar mode affects its detectability.

  7. Method for simultaneous measurement of mass loading and fluid property changes using a quartz crystal microbalance

    DOEpatents

    Granstaff, Victoria E.; Martin, Stephen J.

    1993-01-01

    A method, using a quartz crystal microbalance, to obtain simultaneous measurement of solid mass accumulation and changes in liquid density-viscosity product. The simultaneous real-time measurements of electrical parameters yields that changes in surface mass can be differentiated from changes in solution properties. Two methods to obtain the admittance/frequency data are employed.

  8. Method for simultaneous measurement of mass loading and fluid property changes using a quartz crystal microbalance

    DOEpatents

    Granstaff, V.E.; Martin, S.J.

    1993-04-13

    A method is described, using a quartz crystal microbalance, to obtain simultaneous measurement of solid mass accumulation and changes in liquid density-viscosity product. The simultaneous real-time measurements of electrical parameters yields that changes in surface mass can be differentiated from changes in solution properties. Two methods to obtain the admittance/frequency data are employed.

  9. Some exact tests for manifest properties of latent trait models

    PubMed Central

    De Gooijer, Jan G.; Yuan, Ao

    2011-01-01

    Item response theory is one of the modern test theories with applications in educational and psychological testing. Recent developments made it possible to characterize some desired properties in terms of a collection of manifest ones, so that hypothesis tests on these traits can, in principle, be performed. But the existing test methodology is based on asymptotic approximation, which is impractical in most applications since the required sample sizes are often unrealistically huge. To overcome this problem, a class of tests is proposed for making exact statistical inference about four manifest properties: covariances given the sum are non-positive (CSN), manifest monotonicity (MM), conditional association (CA), and vanishing conditional dependence (VCD). One major advantage is that these exact tests do not require large sample sizes. As a result, tests for CSN and MM can be routinely performed in empirical studies. For testing CA and VCD, the exact methods are still impractical in most applications, due to the unusually large number of parameters to be tested. However, exact methods are still derived for them as an exploration toward practicality. Some numerical examples with applications of the exact tests for CSN and MM are provided. PMID:21562625

  10. Correlation Results for a Mass Loaded Vehicle Panel Test Article Finite Element Models and Modal Survey Tests

    NASA Technical Reports Server (NTRS)

    Maasha, Rumaasha; Towner, Robert L.

    2012-01-01

    High-fidelity Finite Element Models (FEMs) were developed to support a recent test program at Marshall Space Flight Center (MSFC). The FEMs correspond to test articles used for a series of acoustic tests. Modal survey tests were used to validate the FEMs for five acoustic tests (a bare panel and four different mass-loaded panel configurations). An additional modal survey test was performed on the empty test fixture (orthogrid panel mounting fixture, between the reverb and anechoic chambers). Modal survey tests were used to test-validate the dynamic characteristics of FEMs used for acoustic test excitation. Modal survey testing and subsequent model correlation has validated the natural frequencies and mode shapes of the FEMs. The modal survey test results provide a basis for the analysis models used for acoustic loading response test and analysis comparisons

  11. Statistical properties of the USP dissolution test with pooled samples.

    PubMed

    Saccone, Carlos D; Meneces, Nora S; Tessore, Julio

    2005-01-01

    The Montecarlo simulation method is used to study the statistical properties of the USP pooled dissolution test. In this paper, the statistical behavior of the dissolution test for pooled samples is studied, including: a) the operating characteristic curve showing the probability of passing the test versus the mean amount dissolved, b) the influence of measurement uncertainty on the result of the test, c) an analysis of the dependence of the statistical behavior on the underlying distribution of the individual amounts dissolved, d) a comparison of the statistical behavior of the unit dissolution test versus the pooled dissolution test, e) the average number of stages needed to reach a decision presented as a function of parameters of the lot, f) the relative influence of the three stages of the test on the probability of acceptance.

  12. Mass extinctions and cosmic collisions - A lunar test

    NASA Technical Reports Server (NTRS)

    Horz, F.

    1985-01-01

    The possibility has been considered that some or all major mass extinctions in the geologic record of earth are caused by the collision of massive, cosmic objects. Thus, it has been proposed that the unusual concentration of siderophile elements in strata at which the boundary between the Cretaceous (K) and Tertiary (T) geologic time periods has been placed must represent the remnants of a gigantic meteorite. However, a large 65-m.y.-old crater which could have been the result of the impact of this meteorite is not presently known on earth. One approach to evaluate the merits of the collisional hypothesis considered is based on the study of the probability of collision between a cosmic object of a suitable size and the earth. As moon and earth were subject to the same bombardment history and the preservation of craters on the moon is much better than on earth, a consideration of the lunar cratering record may provide crucial information.

  13. Mass extinctions and cosmic collisions - A lunar test

    NASA Technical Reports Server (NTRS)

    Horz, F.

    1985-01-01

    The possibility has been considered that some or all major mass extinctions in the geologic record of earth are caused by the collision of massive, cosmic objects. Thus, it has been proposed that the unusual concentration of siderophile elements in strata at which the boundary between the Cretaceous (K) and Tertiary (T) geologic time periods has been placed must represent the remnants of a gigantic meteorite. However, a large 65-m.y.-old crater which could have been the result of the impact of this meteorite is not presently known on earth. One approach to evaluate the merits of the collisional hypothesis considered is based on the study of the probability of collision between a cosmic object of a suitable size and the earth. As moon and earth were subject to the same bombardment history and the preservation of craters on the moon is much better than on earth, a consideration of the lunar cratering record may provide crucial information.

  14. Estimation of Mechanical Properties of Stainless Steel AISI 410 by Small-Punch Testing (Erickson Test)

    NASA Astrophysics Data System (ADS)

    Hassan, A.-P.

    2014-07-01

    The small-punch testing (SPT) method is used for determining the mechanical properties of AISI 410 (0.14% C, 12% Cr) stainless steel. A thin disc-shaped specimen with known mechanical properties is pressed with a small ball until the appearance of cracks in the former. The load - displacement curves are recorded. Computation of the yield strength and fracture energy by the curve obtained and by known formulas shows good convergence with the characteristics obtained by standard testing.

  15. Venus cloud properties - Infrared opacity and mass mixing ratio

    NASA Technical Reports Server (NTRS)

    Samuelson, R. E.; Hanel, R. A.; Herath, L. W.; Kunde, V. G.; Maguire, W. C.

    1975-01-01

    By using the Mariner 5 temperature profile and a homogeneous cloud model, and assuming that CO2 and cloud particles are the only opacity sources, the wavelength dependence of the Venus cloud opacity is inferred from the infrared spectrum of the planet between 450 and 1250 per cm. Volume extinction coefficients varying from 0.000005 to 0.000015 per cm, depending on the wavelength, are determined at the tropopause level of 6110 km. By using all available data, a cloud mass mixing ratio of approximately 0.000005 and a particle concentration of about 900 particles per cu cm at this level are also inferred. The derived cloud opacity compares favorably with that expected for a haze of droplets of a 75% aqueous solution of sulfuric acid.

  16. Tests of blending and correlation of distillate fuel properties

    NASA Technical Reports Server (NTRS)

    Erwin, J.; Bowden, J. N.

    1982-01-01

    The development of a fuel test matrix, results from tests of several blends of distillate aircraft fuels, and the use of correlations in formulation determination during a NASA-sponsored program to identify new aircraft fuels are described. The program was initiated in order to characterize fuel blends which are appropriate for different types of combustors in use and under development. The fuels were required to feature a specified range of properties. Attention is given to fuel volatility, hydrogen content, aromatic content, freezing point, kinematic viscosity, and naphthalene content. Paraffinic and naphtenic base stocks were employed, using alkyl benzene, naphthene benzenes, and naphthalenes to adjust the blend properties. Categories for the test fuels comprised source-controlled and composition controlled fuels. Test results and compositions of various fuels are provided.

  17. Systematic characterization of porosity and mass transport and mechanical properties of porous polyurethane scaffolds.

    PubMed

    Wang, Yu-Fu; Barrera, Carlos M; Dauer, Edward A; Gu, Weiyong; Andreopoulos, Fotios; Huang, C-Y Charles

    2017-01-01

    One of the key challenges in porous scaffold design is to create a porous structure with desired mechanical function and mass transport properties which support delivery of biofactors and development of function tissue substitute. In recent years, polyurethane (PU) has become one of the most popular biomaterials in various tissue engineering fields. However, there are no studies fully investigating the relations between porosity and both mass transport and mechanical properties of PU porous scaffolds. In this paper, we fabricated PU scaffolds by combining phase inversion and salt (sodium chloride) leaching methods. The tensile and compressive moduli were examined on PU scaffolds fabricated with different PU concentrations (25%, 20% and 15% w/v) and salt/PU weight ratios (9/1, 6/1, 3/1 and 0/1). The mass transport properties of PU scaffolds including hydraulic permeability and glucose diffusivity were also measured. Furthermore, the relationships between the porosity and mass transport and mechanical properties of porous PU scaffold were systemically investigated. The results demonstrated that porosity is a key parameter which governs both mass transport and mechanical properties of porous PU scaffolds. With similar pore sizes, the mass transport and mechanical properties of porous PU scaffold can be described as single functions of porosity regardless of initial PU concentration. The relationships between scaffold porosity and properties can be utilized to facilitate porous PU scaffold fabrication with specific mass transport and mechanical properties. The systematic approach established in this study can be applied to characterization of other biomaterials for scaffold design and fabrication.

  18. Southeast Atlantic Cloud Properties in a Multivariate Statistical Model - How Relevant is Air Mass History for Local Cloud Properties?

    NASA Astrophysics Data System (ADS)

    Fuchs, Julia; Cermak, Jan; Andersen, Hendrik

    2017-04-01

    This study aims at untangling the impacts of external dynamics and local conditions on cloud properties in the Southeast Atlantic (SEA) by combining satellite and reanalysis data using multivariate statistics. The understanding of clouds and their determinants at different scales is important for constraining the Earth's radiative budget, and thus prominent in climate-system research. In this study, SEA stratocumulus cloud properties are observed not only as the result of local environmental conditions but also as affected by external dynamics and spatial origins of air masses entering the study area. In order to assess to what extent cloud properties are impacted by aerosol concentration, air mass history, and meteorology, a multivariate approach is conducted using satellite observations of aerosol and cloud properties (MODIS, SEVIRI), information on aerosol species composition (MACC) and meteorological context (ERA-Interim reanalysis). To account for the often-neglected but important role of air mass origin, information on air mass history based on HYSPLIT modeling is included in the statistical model. This multivariate approach is intended to lead to a better understanding of the physical processes behind observed stratocumulus cloud properties in the SEA.

  19. PPT-DB: the protein property prediction and testing database

    PubMed Central

    Wishart, David S.; Arndt, David; Berjanskii, Mark; Guo, An Chi; Shi, Yi; Shrivastava, Savita; Zhou, Jianjun; Zhou, You; Lin, Guohui

    2008-01-01

    The protein property prediction and testing database (PPT-DB) is a database housing nearly 30 carefully curated databases, each of which contains commonly predicted protein property information. These properties include both structural (i.e. secondary structure, contact order, disulfide pairing) and dynamic (i.e. order parameters, B-factors, folding rates) features that have been measured, derived or tabulated from a variety of sources. PPT-DB is designed to serve two purposes. First it is intended to serve as a centralized, up-to-date, freely downloadable and easily queried repository of predictable or ‘derived’ protein property data. In this role, PPT-DB can serve as a one-stop, fully standardized repository for developers to obtain the required training, testing and validation data needed for almost any kind of protein property prediction program they may wish to create. The second role that PPT-DB can play is as a tool for homology-based protein property prediction. Users may query PPT-DB with a sequence of interest and have a specific property predicted using a sequence similarity search against PPT-DB's extensive collection of proteins with known properties. PPT-DB exploits the well-known fact that protein structure and dynamic properties are highly conserved between homologous proteins. Predictions derived from PPT-DB's similarity searches are typically 85–95% correct (for categorical predictions, such as secondary structure) or exhibit correlations of >0.80 (for numeric predictions, such as accessible surface area). This performance is 10–20% better than what is typically obtained from standard ‘ab initio’ predictions. PPT-DB, its prediction utilities and all of its contents are available at http://www.pptdb.ca PMID:17916570

  20. PPT-DB: the protein property prediction and testing database.

    PubMed

    Wishart, David S; Arndt, David; Berjanskii, Mark; Guo, An Chi; Shi, Yi; Shrivastava, Savita; Zhou, Jianjun; Zhou, You; Lin, Guohui

    2008-01-01

    The protein property prediction and testing database (PPT-DB) is a database housing nearly 30 carefully curated databases, each of which contains commonly predicted protein property information. These properties include both structural (i.e. secondary structure, contact order, disulfide pairing) and dynamic (i.e. order parameters, B-factors, folding rates) features that have been measured, derived or tabulated from a variety of sources. PPT-DB is designed to serve two purposes. First it is intended to serve as a centralized, up-to-date, freely downloadable and easily queried repository of predictable or 'derived' protein property data. In this role, PPT-DB can serve as a one-stop, fully standardized repository for developers to obtain the required training, testing and validation data needed for almost any kind of protein property prediction program they may wish to create. The second role that PPT-DB can play is as a tool for homology-based protein property prediction. Users may query PPT-DB with a sequence of interest and have a specific property predicted using a sequence similarity search against PPT-DB's extensive collection of proteins with known properties. PPT-DB exploits the well-known fact that protein structure and dynamic properties are highly conserved between homologous proteins. Predictions derived from PPT-DB's similarity searches are typically 85-95% correct (for categorical predictions, such as secondary structure) or exhibit correlations of >0.80 (for numeric predictions, such as accessible surface area). This performance is 10-20% better than what is typically obtained from standard 'ab initio' predictions. PPT-DB, its prediction utilities and all of its contents are available at http://www.pptdb.ca.

  1. Hanford Apatite Treatability Test Report Errata: Apatite Mass Loading Calculation

    SciTech Connect

    Szecsody, James E.; Vermeul, Vincent R.; Williams, Mark D.; Truex, Michael J.

    2014-05-19

    The objective of this errata report is to document an error in the apatite loading (i.e., treatment capacity) estimate reported in previous apatite treatability test reports and provide additional calculation details for estimating apatite loading and barrier longevity. The apatite treatability test final report (PNNL-19572; Vermeul et al. 2010) documents the results of the first field-scale evaluation of the injectable apatite PRB technology. The apatite loading value in units of milligram-apatite per gram-sediment is incorrect in this and some other previous reports. The apatite loading in units of milligram phosphate per gram-sediment, however, is correct, and this is the unit used for comparison to field core sample measurements.

  2. Applicability of geomechanical classifications for estimation of strength properties in Brazilian rock masses.

    PubMed

    Santos, Tatiana B; Lana, Milene S; Santos, Allan E M; Silveira, Larissa R C

    2017-01-01

    Many authors have been proposed several correlation equations between geomechanical classifications and strength parameters. However, these correlation equations have been based in rock masses with different characteristics when compared to Brazilian rock masses. This paper aims to study the applicability of the geomechanical classifications to obtain strength parameters of three Brazilian rock masses. Four classification systems have been used; the Rock Mass Rating (RMR), the Rock Mass Quality (Q), the Geological Strength Index (GSI) and the Rock Mass Index (RMi). A strong rock mass and two soft rock masses with different degrees of weathering located in the cities of Ouro Preto and Mariana, Brazil; were selected for the study. Correlation equations were used to estimate the strength properties of these rock masses. However, such correlations do not always provide compatible results with the rock mass behavior. For the calibration of the strength values obtained through the use of classification systems, ​​stability analyses of failures in these rock masses have been done. After calibration of these parameters, the applicability of the various correlation equations found in the literature have been discussed. According to the results presented in this paper, some of these equations are not suitable for the studied rock masses.

  3. Numerical Calibration of Mass Flow Plug for Inlet Testing

    NASA Technical Reports Server (NTRS)

    Sasson, Jonathan; Barnhart, Paul; Davis, David O.

    2015-01-01

    A simple control volume model has been developed to calculate the discharge coefficient through a mass flow plug (MFP) and validated with a calibration experiment. The maximum error of the model within the operating region of the MFP is 0.54%. The control volume analysis developed work is comprised of a sequence of flow calculations through the MFP. The model uses the MFP geometry and operating pressure and temperature to couple continuity, momentum, energy, an equation of state, and wall shear. The discharge coefficient calculation also includes the effects of boundary layer growth, including the reduction in cross-sectional flow area as characterized by the boundary layer displacement thickness. The last calculation in the sequence uses an integral method to calculate the growth of the boundary layer, from which the displacement thickness is then determined. The result of these successive calculations is an accurate one-dimension model of the velocity, pressure, and temperature through the MFP. For comparison, a computational fluid dynamic (CFD) calibration is shown, which when compared to the presented numerical model, had a lower accuracy with a maximum error of 1.35% in addition to being slower by a factor of 100."

  4. Mechanical properties testing and results for thermal barrier coatings

    NASA Technical Reports Server (NTRS)

    Cruse, Thomas A.; Johnsen, B. P.; Nagy, Andrew

    1995-01-01

    The paper reports on several years of mechanical testing of thermal barrier coatings. The test results were generated to support the development of durability models for the coatings in heat engine applications. The test data that are reviewed include modulus, static strength, and fatigue strength data. The test methods and results are discussed, along with the significant difficulties inherent in mechanical testing of thermal barrier coating materials. The materials include 7 percent wt. and 8 percent wt. yttria, partially stabilized zirconia as well as a cermet material. Both low pressure plasma spray and electron-beam physical vapor deposited coatings were tested. The data indicate the basic trends in the mechanical properties of the coatings over a wide range of isothermal conditions. Some of the trends are correlated with material density.

  5. Mechanical properties testing and results for thermal barrier coatings

    NASA Technical Reports Server (NTRS)

    Cruse, Thomas A.; Johnsen, B. P.; Nagy, Andrew

    1995-01-01

    The paper reports on several years of mechanical testing of thermal barrier coatings. The test results were generated to support the development of durability models for the coatings in heat engine applications. The test data that are reviewed include modulus, static strength, and fatigue strength data. The test methods and results are discussed, along with the significant difficulties inherent in mechanical testing of thermal barrier coating materials. The materials include 7 percent wt. and 8 percent wt. yttria, partially stabilized zirconia as well as a cermet material. Both low pressure plasma spray and electron-beam physical vapor deposited coatings were tested. The data indicate the basic trends in the mechanical properties of the coatings over a wide range of isothermal conditions. Some of the trends are correlated with material density.

  6. Properties of Boolean networks and methods for their tests

    PubMed Central

    2013-01-01

    Transcriptional regulation networks are often modeled as Boolean networks. We discuss certain properties of Boolean functions (BFs), which are considered as important in such networks, namely, membership to the classes of unate or canalizing functions. Of further interest is the average sensitivity (AS) of functions. In this article, we discuss several algorithms to test the properties of interest. To test canalizing properties of functions, we apply spectral techniques, which can also be used to characterize the AS of functions as well as the influences of variables in unate BFs. Further, we provide and review upper and lower bounds on the AS of unate BFs based on the spectral representation. Finally, we apply these methods to a transcriptional regulation network of Escherichia coli, which controls central parts of the E. coli metabolism. We find that all functions are unate. Also the analysis of the AS of the network reveals an exceptional robustness against transient fluctuations of the binary variables.a PMID:23311536

  7. Venus cloud properties: Infrared opacity and mass mixing ratio

    NASA Technical Reports Server (NTRS)

    Samuelson, R. E.; Hanel, R. A.; Herath, L. W.; Kunde, V. G.; Maguire, W. C.

    1974-01-01

    By using the Mariner 5 temperature profile and a homogeneous cloud model, and assuming that CO2 and cloud particles are the only opacity sources, the wavelength dependence of the Venus cloud opacity is inferred from the infrared spectrum of the planet between 450 and 1250/cm. Justification for applying the homogeneous cloud model is found in the fact that numerous polarization and infrared data are mutually consistent within the framework of such a model; on the other hand, dense cloud models are not satisfactory. Volume extinction coefficients varying from 0.000005 to 0.000015/cm depending on the wavelength, are determined at the tropopause level of 6110 km. By using all available data, a cloud mass mixing ratio of approximately 0.000005 and a particle concentration of about 900 particles per cu cm at this level are also inferred. The derived cloud opacity compares favorably with that expected for a haze of droplets of a 75% aqueous solution of sulfuric acid.

  8. The influence of body mass index and gender on the impact attenuation properties of flooring systems.

    PubMed

    Bhan, Shivam; Levine, Iris; Laing, Andrew C

    2013-12-01

    The biomechanical effectiveness of safety floors has never been assessed during sideways falls with human volunteers. Furthermore, the influence of body mass index (BMI) and gender on the protective capacity of safety floors is unknown. The purpose of this study was to test whether safety floors provide greater impact attenuation compared with traditional flooring, and whether BMI and gender modify their impact attenuation properties. Thirty participants (7 men and 7 women of low BMI; 7 men and 9 women of high BMI) underwent lateral pelvis release trials on 2 common floors and 4 safety floors. As a group, the safety floors reduced peak force (by up to 11.7%), and increased the time to peak force (by up to 25.5%) compared with a traditional institutional grade floor. Force attenuation was significantly higher for the low BMI group, and for males. Force attenuation was greatest for the low BMI males, averaging 26.5% (SD = 3.0) across the safety floors. These findings demonstrate an overall protective effect of safety floors during lateral falls on the pelvis, but also suggest augmented benefits for frail older adults (often with low body mass) who are at an increased risk of hip fracture.

  9. Mass transport growth and optical emission properties of hydride vapor phase epitaxy GaN

    NASA Astrophysics Data System (ADS)

    Paskova, T.; Goldys, E. M.; Paskov, P. P.; Wahab, Q.; Wilzen, L.; de Jong, M. P.; Monemar, B.

    2001-06-01

    The optical emission properties of mass-transport regions of GaN grown by hydride vapor phase epitaxy are studied by cathodoluminescence imaging and spectroscopy. A strong donor-acceptor pair emission is observed from the mass-transport regions. Spatially resolved cathodoluminescence reveals a strong intensity contrast between the exciton and donor-acceptor bands from mass-transport and nontransport regions. Focused Auger electron and x-ray photoelectron spectroscopies were employed to investigate the impurity incorporation in the different regions. A preferential moderate increase of residual impurity incorporation or redistribution in mass-transport regions is suggested to be responsible for the observed change of the dominant radiative mechanism.

  10. Discordant recovery of bone mass and mechanical properties during prolonged recovery from disuse.

    PubMed

    Shirazi-Fard, Yasaman; Kupke, Joshua S; Bloomfield, Susan A; Hogan, Harry A

    2013-01-01

    Profound bone loss at weight bearing sites is a primary effect of long-duration spaceflight. Moreover, a significant increase in estimated fracture risk remains even 1 year after returning to Earth; hence, it is important to define how quickly bone integrity can recover following prolonged disuse. This study characterized the loss and recovery dynamics of bone following a period of rodent hindlimb unloading in three anatomic sites. We hypothesized that the rat femoral neck would exhibit a discordant recovery dynamic most similar to that observed in astronauts' proximal femur; that is, bone mineral content (absolute mass) at this site would recover faster and more completely than would bone density and cortical area, and they will all recover before bone strength does. We characterized loss and long-term recovery of densitometric properties at the femoral neck, proximal tibia metaphysis, and tibia diaphysis, and also mechanical properties at the femoral neck and tibia diaphysis for which mechanical testing is amenable. We assessed the relationship between calculated strength indices and measured mechanical properties. Adult male Sprague-Dawley rats (6 months) were assigned to baseline, age-matched control (AC), and hindlimb unloaded (HU) groups. The HU group was unloaded for 28 days and then returned to normal cage activity for 84 days of weight bearing recovery (3 times the duration of HU). Fifteen animals were euthanized from each of the HU and AC groups on days 28, 56, 84, and 112 of the study. At baseline and then every 28 days in vivo longitudinal pQCT scans were taken at proximal tibia metaphysis (PTM) and tibia diaphysis (TD); ex vivo pQCT scans were taken later at the femoral neck (FN). TD and FN were tested to failure to measure mechanical properties. The hypothesis that the femoral neck in rats will exhibit a discordant recovery dynamic most similar to that observed in astronauts' proximal femurs was not supported by our data. At the femoral neck

  11. Galaxy and Mass Assembly (GAMA): merging galaxies and their properties

    NASA Astrophysics Data System (ADS)

    De Propris, Roberto; Baldry, Ivan K.; Bland-Hawthorn, Joss; Brough, Sarah; Driver, Simon P.; Hopkins, Andrew M.; Kelvin, Lee; Loveday, Jon; Phillipps, Steve; Robotham, Aaron S. G.

    2014-11-01

    We derive the close pair fractions and volume merger rates for galaxies in the Galaxy and Mass Assembly (GAMA) survey with -23 < Mr < -17 (ΩM = 0.27, ΩΛ = 0.73, H0 = 100 km s-1 Mpc-1) at 0.01 < z < 0.22 (look-back time of <2 Gyr). The merger fraction is approximately 1.5 per cent Gyr-1 at all luminosities (assuming 50 per cent of pairs merge) and the volume merger rate is ≈3.5 × 10-4 Mpc-3 Gyr-1. We examine how the merger rate varies by luminosity and morphology. Dry mergers (between red/spheroidal galaxies) are found to be uncommon and to decrease with decreasing luminosity. Fainter mergers are wet, between blue/discy galaxies. Damp mergers (one of each type) follow the average of dry and wet mergers. In the brighter luminosity bin (-23 < Mr < -20), the merger rate evolution is flat, irrespective of colour or morphology, out to z ˜ 0.2. The makeup of the merging population does not appear to change over this redshift range. Galaxy growth by major mergers appears comparatively unimportant and dry mergers are unlikely to be significant in the buildup of the red sequence over the past 2 Gyr. We compare the colour, morphology, environmental density and degree of activity (BPT class, Baldwin, Phillips & Terlevich) of galaxies in pairs to those of more isolated objects in the same volume. Galaxies in close pairs tend to be both redder and slightly more spheroid dominated than the comparison sample. We suggest that this may be due to `harassment' in multiple previous passes prior to the current close interaction. Galaxy pairs do not appear to prefer significantly denser environments. There is no evidence of an enhancement in the AGN fraction in pairs, compared to other galaxies in the same volume.

  12. Rock mass mechanical property estimations for the Yucca Mountain Site Characterization Project; Yucca Mountain Site Characterization Project

    SciTech Connect

    Lin, M.; Hardy, M.P.; Bauer, S.J.

    1993-06-01

    Rock mass mechanical properties are important in the design of drifts and ramps. These properties are used in evaluations of the impacts of thermomechanical loading of potential host rock within the Yucca Mountain Site Characterization Project. Representative intact rock and joint mechanical properties were selected for welded and nonwelded tuffs from the currently available data sources. Rock mass qualities were then estimated using both the Norwegian Geotechnical Institute (Q) and Geomechanics Rating (RMR) systems. Rock mass mechanical properties were developed based on estimates of rock mass quality, the current knowledge of intact properties, and fracture/joint characteristics. Empirical relationships developed to correlate the rock mass quality indices and the rock mass mechanical properties were then used to estimate the range of rock mass mechanical properties.

  13. Testing techniques for determining static mechanical properties of Pneumatic tires

    NASA Technical Reports Server (NTRS)

    Dodge, R. N.; Larson, R. B.; Clark, S. K.; Nybakken, G. H.

    1974-01-01

    Fore-aft, lateral, and vertical spring rates of model and full-scale pneumatic tires were evaluated by testing techniques generally employed by industry and various testing groups. The purpose of this experimental program was to investigate what effects the different testing techniques have on the measured values of these important static tire mechanical properties. The testing techniques included both incremental and continuous loadings applied at various rates over half, full, and repeated cycles. Of the three properties evaluated, the fore-aft stiffness was demonstrated to be the most affected by the different testing techniques used to obtain it. Appreciable differences in the fore-aft spring rates occurred using both the increment- and continuous-loading techniques; however, the most significant effect was attributed to variations in the size of the fore-aft force loop. The dependence of lateral stiffness values on testing techniques followed the same trends as that for fore-aft stiffness, except to a lesser degree. Vertical stiffness values were found to be nearly independent of testing procedures if the nonlinear portion of the vertical force-deflection curves is avoided.

  14. Transport processes in partially saturate concrete: Testing and liquid properties

    NASA Astrophysics Data System (ADS)

    Villani, Chiara

    The measurement of transport properties of concrete is considered by many to have the potential to serve as a performance criterion that can be related to concrete durability. However, the sensitivity of transport tests to several parameters combined with the low permeability of concrete complicates the testing. Gas permeability and diffusivity test methods are attractive due to the ease of testing, their non-destructive nature and their potential to correlate to in-field carbonation of reinforced concrete structures. This work was aimed at investigating the potential of existing gas transport tests as a way to reliably quantify transport properties in concrete. In this study gas permeability and diffusivity test methods were analyzed comparing their performance in terms of repeatability and variability. The influence of several parameters was investigated such as moisture content, mixture proportions and gas flow. A closer look to the influence of pressure revealed an anomalous trend of permeability with respect to pressure. An alternative calculation is proposed in an effort to move towards the determination of intrinsic material properties that can serve as an input for service life prediction models. The impact of deicing salts exposure was also analyzed with respect to their alteration of the degree of saturation as this may affect gas transport in cementitious materials. Limited information were previously available on liquid properties over a wide range of concentrations. To overcome this limitation, this study quantified surface tension, viscosity in presence of deicing salts in a broad concentration range and at different temperatures. Existing models were applied to predict the change of fluid properties during drying. Vapor desorption isotherms were obtained to investigate the influence of deicing salts presence on the non-linear moisture diffusion coefficient. Semi-empirical models were used to quantify the initiation and the rate of drying using liquid

  15. Molecular outflows driven by low-mass protostars. I. Correcting for underestimates when measuring outflow masses and dynamical properties

    SciTech Connect

    Dunham, Michael M.; Arce, Héctor G.; Mardones, Diego; Lee, Jeong-Eun; Matthews, Brenda C.; Stutz, Amelia M.; Williams, Jonathan P.

    2014-03-01

    We present a survey of 28 molecular outflows driven by low-mass protostars, all of which are sufficiently isolated spatially and/or kinematically to fully separate into individual outflows. Using a combination of new and archival data from several single-dish telescopes, 17 outflows are mapped in {sup 12}CO (2-1) and 17 are mapped in {sup 12}CO (3-2), with 6 mapped in both transitions. For each outflow, we calculate and tabulate the mass (M {sub flow}), momentum (P {sub flow}), kinetic energy (E {sub flow}), mechanical luminosity (L {sub flow}), and force (F {sub flow}) assuming optically thin emission in LTE at an excitation temperature, T {sub ex}, of 50 K. We show that all of the calculated properties are underestimated when calculated under these assumptions. Taken together, the effects of opacity, outflow emission at low velocities confused with ambient cloud emission, and emission below the sensitivities of the observations increase outflow masses and dynamical properties by an order of magnitude, on average, and factors of 50-90 in the most extreme cases. Different (and non-uniform) excitation temperatures, inclination effects, and dissociation of molecular gas will all work to further increase outflow properties. Molecular outflows are thus almost certainly more massive and energetic than commonly reported. Additionally, outflow properties are lower, on average, by almost an order of magnitude when calculated from the {sup 12}CO (3-2) maps compared to the {sup 12}CO (2-1) maps, even after accounting for different opacities, map sensitivities, and possible excitation temperature variations. It has recently been argued in the literature that the {sup 12}CO (3-2) line is subthermally excited in outflows, and our results support this finding.

  16. Testing the Recovery of Intrinsic Galaxy Sizes and Masses of z ˜ 2 Massive Galaxies Using Cosmological Simulations

    NASA Astrophysics Data System (ADS)

    Price, Sedona H.; Kriek, Mariska; Feldmann, Robert; Quataert, Eliot; Hopkins, Philip F.; Faucher-Giguère, Claude-André; Kereš, Dušan; Barro, Guillermo

    2017-07-01

    Accurate measurements of galaxy masses and sizes are key to tracing galaxy evolution over time. Cosmological zoom-in simulations provide an ideal test bed for assessing the recovery of galaxy properties from observations. Here, we utilize galaxies with {M}* ˜ {10}10{--}{10}11.5 {M}⊙ at z ˜ 1.7-2 from the MassiveFIRE cosmological simulation suite, part of the Feedback in Realistic Environments (FIRE) project. Using mock multi-band images, we compare intrinsic galaxy masses and sizes to observational estimates. We find that observations accurately recover stellar masses, with a slight average underestimate of ˜ 0.06 {dex} and {{a}}˜ 0.15 {dex} scatter. Recovered half-light radii agree well with intrinsic half-mass radii when averaged over all viewing angles, with a systematic offset of ˜ 0.1 {dex} (with the half-light radii being larger) and a scatter of ˜ 0.2 {dex}. When using color gradients to account for mass-to-light variations, recovered half-mass radii also exceed the intrinsic half-mass radii by ˜ 0.1 {dex}. However, if not properly accounted for, aperture effects can bias size estimates by ˜ 0.1 {dex}. No differences are found between the mass and size offsets for star-forming and quiescent galaxies. Variations in viewing angle are responsible for ˜25% of the scatter in the recovered masses and sizes. Our results thus suggest that the intrinsic scatter in the mass-size relation may have previously been overestimated by ˜25%. Moreover, orientation-driven scatter causes the number density of very massive galaxies to be overestimated by ˜ 0.5 {dex} at {M}* ˜ {10}11.5 {M}⊙ .

  17. Selective mass labeling for linking the optical properties of chromophoric dissolved organic matter to structure and composition via ultrahigh resolution electrospray ionization mass spectrometry.

    PubMed

    Baluha, Daniel R; Blough, Neil V; Del Vecchio, Rossana

    2013-09-03

    The mass spectra acquired by ESI FT-ICR MS of untreated, borohydride-reduced, and borodeuteride-reduced samples of Suwannee River fulvic acid (SRFA) and a C18 extract from the upper Delaware Bay were compared to one another. Treatment of these samples with sodium borodeuteride was shown to produce unique mass labels for species which contain one or two ketone/aldehyde moieties. Approximately 30% of all identified peaks in the two samples were shown to comprise ketone/aldehyde-containing species. The molecular formulas of the majority of these species had O/C and H/C molar ratios typically attributed to lignin-derived compounds and/or carboxylic rich alicyclic molecules (CRAM). However, the significant loss of UV-vis absorption following reduction supports a lignin-based origin for the optical (and photochemical) properties of these samples. The mass-labeling method described and tested herein shows great promise as a means to further characterize the structure and composition of complex natural samples, especially in terms of identifying specific subsets of chemical species that contribute significantly to the optical and photochemical properties of such samples.

  18. Tracer mass recovery in fractured aquifers estimated from multiple well tests.

    PubMed

    Sanford, William E; Cook, Peter G; Robinson, Neville I; Weatherill, Douglas

    2006-01-01

    Forced-gradient tracer tests in fractured aquifers often report low mass recoveries. In fractured aquifers, fractures intersected by one borehole may not be intersected by another. As a result (1) injected tracer can follow pathways away from the withdrawal well causing low mass recovery and (2) recovered water can follow pathways not connected to the injection well causing significant tracer dilution. These two effects occur along with other forms of apparent mass loss. If the strength of the connection between wells and the amount of dilution can be predicted ahead of time, tracer tests can be designed to optimize mass recovery and dilution. A technique is developed to use hydraulic tests in fractured aquifers to calculate the conductance (strength of connection) between well pairs and to predict mass recovery and amount of dilution during forced gradient tracer tests. Flow is considered to take place through conduits, which connect the wells to each other and to distant sources or sinks. Mass recovery is related to the proportion of flow leaving the injection well and arriving at the withdrawal well, and dilution is related to the proportion of the flow from the withdrawal well that is derived from the injection well. The technique can be used to choose well pairs for tracer tests, what injection and withdrawal rates to use, and which direction to establish the hydraulic gradient to maximize mass recovery and/or minimize dilution. The method is applied to several tracer tests in fractured aquifers in the Clare Valley, South Australia.

  19. Heat-flow properties of systems with alternate masses or alternate on-site potentials.

    PubMed

    Pereira, Emmanuel; Santana, Leonardo M; Ávila, Ricardo

    2011-07-01

    We address a central issue of phononics: the search of properties or mechanisms to manage the heat flow in reliable materials. We analytically study standard and simple systems modeling the heat flow in solids, namely, the harmonic, self-consistent harmonic and also anharmonic chains of oscillators, and we show an interesting insulating effect: While in the homogeneous models the heat flow decays as the inverse of the particle mass, in the chain with alternate masses it decays as the inverse of the square of the mass difference, that is, it decays essentially as the mass ratio (between the smaller and the larger one) for a large mass difference. A similar effect holds if we alternate on-site potentials instead of particle masses. The existence of such behavior in these different systems, including anharmonic models, indicates that it is a ubiquitous phenomenon with applications in the heat flow control.

  20. Aircraft Structural Mass Property Prediction Using Conceptual-Level Structural Analysis

    NASA Technical Reports Server (NTRS)

    Sexstone, Matthew G.

    1998-01-01

    This paper describes a methodology that extends the use of the Equivalent LAminated Plate Solution (ELAPS) structural analysis code from conceptual-level aircraft structural analysis to conceptual-level aircraft mass property analysis. Mass property analysis in aircraft structures has historically depended upon parametric weight equations at the conceptual design level and Finite Element Analysis (FEA) at the detailed design level ELAPS allows for the modeling of detailed geometry, metallic and composite materials, and non-structural mass coupled with analytical structural sizing to produce high-fidelity mass property analyses representing fully configured vehicles early in the design process. This capability is especially valuable for unusual configuration and advanced concept development where existing parametric weight equations are inapplicable and FEA is too time consuming for conceptual design. This paper contrasts the use of ELAPS relative to empirical weight equations and FEA. ELAPS modeling techniques are described and the ELAPS-based mass property analysis process is detailed Examples of mass property stochastic calculations produced during a recent systems study are provided This study involved the analysis of three remotely piloted aircraft required to carry scientific payloads to very high altitudes at subsonic speeds. Due to the extreme nature of this high-altitude flight regime,few existing vehicle designs are available for use in performance and weight prediction. ELAPS was employed within a concurrent engineering analysis process that simultaneously produces aerodynamic, structural, and static aeroelastic results for input to aircraft performance analyses. The ELAPS models produced for each concept were also used to provide stochastic analyses of wing structural mass properties. The results of this effort indicate that ELAPS is an efficient means to conduct multidisciplinary trade studies at the conceptual design level.

  1. Aircraft Structural Mass Property Prediction Using Conceptual-Level Structural Analysis

    NASA Technical Reports Server (NTRS)

    Sexstone, Matthew G.

    1998-01-01

    This paper describes a methodology that extends the use of the Equivalent LAminated Plate Solution (ELAPS) structural analysis code from conceptual-level aircraft structural analysis to conceptual-level aircraft mass property analysis. Mass property analysis in aircraft structures has historically depended upon parametric weight equations at the conceptual design level and Finite Element Analysis (FEA) at the detailed design level. ELAPS allows for the modeling of detailed geometry, metallic and composite materials, and non-structural mass coupled with analytical structural sizing to produce high-fidelity mass property analyses representing fully configured vehicles early in the design process. This capability is especially valuable for unusual configuration and advanced concept development where existing parametric weight equations are inapplicable and FEA is too time consuming for conceptual design. This paper contrasts the use of ELAPS relative to empirical weight equations and FEA. ELAPS modeling techniques are described and the ELAPS-based mass property analysis process is detailed. Examples of mass property stochastic calculations produced during a recent systems study are provided. This study involved the analysis of three remotely piloted aircraft required to carry scientific payloads to very high altitudes at subsonic speeds. Due to the extreme nature of this high-altitude flight regime, few existing vehicle designs are available for use in performance and weight prediction. ELAPS was employed within a concurrent engineering analysis process that simultaneously produces aerodynamic, structural, and static aeroelastic results for input to aircraft performance analyses. The ELAPS models produced for each concept were also used to provide stochastic analyses of wing structural mass properties. The results of this effort indicate that ELAPS is an efficient means to conduct multidisciplinary trade studies at the conceptual design level.

  2. Target Capturing Control for Space Robots with Unknown Mass Properties: A Self-Tuning Method Based on Gyros and Cameras.

    PubMed

    Li, Zhenyu; Wang, Bin; Liu, Hong

    2016-08-30

    Satellite capturing with free-floating space robots is still a challenging task due to the non-fixed base and unknown mass property issues. In this paper gyro and eye-in-hand camera data are adopted as an alternative choice for solving this problem. For this improved system, a new modeling approach that reduces the complexity of system control and identification is proposed. With the newly developed model, the space robot is equivalent to a ground-fixed manipulator system. Accordingly, a self-tuning control scheme is applied to handle such a control problem including unknown parameters. To determine the controller parameters, an estimator is designed based on the least-squares technique for identifying the unknown mass properties in real time. The proposed method is tested with a credible 3-dimensional ground verification experimental system, and the experimental results confirm the effectiveness of the proposed control scheme.

  3. Target Capturing Control for Space Robots with Unknown Mass Properties: A Self-Tuning Method Based on Gyros and Cameras

    PubMed Central

    Li, Zhenyu; Wang, Bin; Liu, Hong

    2016-01-01

    Satellite capturing with free-floating space robots is still a challenging task due to the non-fixed base and unknown mass property issues. In this paper gyro and eye-in-hand camera data are adopted as an alternative choice for solving this problem. For this improved system, a new modeling approach that reduces the complexity of system control and identification is proposed. With the newly developed model, the space robot is equivalent to a ground-fixed manipulator system. Accordingly, a self-tuning control scheme is applied to handle such a control problem including unknown parameters. To determine the controller parameters, an estimator is designed based on the least-squares technique for identifying the unknown mass properties in real time. The proposed method is tested with a credible 3-dimensional ground verification experimental system, and the experimental results confirm the effectiveness of the proposed control scheme. PMID:27589748

  4. Spatiotemporal properties of microsaccades: Model predictions and experimental tests

    NASA Astrophysics Data System (ADS)

    Zhou, Jian-Fang; Yuan, Wu-Jie; Zhou, Zhao

    2016-10-01

    Microsaccades are involuntary and very small eye movements during fixation. Recently, the microsaccade-related neural dynamics have been extensively investigated both in experiments and by constructing neural network models. Experimentally, microsaccades also exhibit many behavioral properties. It’s well known that the behavior properties imply the underlying neural dynamical mechanisms, and so are determined by neural dynamics. The behavioral properties resulted from neural responses to microsaccades, however, are not yet understood and are rarely studied theoretically. Linking neural dynamics to behavior is one of the central goals of neuroscience. In this paper, we provide behavior predictions on spatiotemporal properties of microsaccades according to microsaccade-induced neural dynamics in a cascading network model, which includes both retinal adaptation and short-term depression (STD) at thalamocortical synapses. We also successfully give experimental tests in the statistical sense. Our results provide the first behavior description of microsaccades based on neural dynamics induced by behaving activity, and so firstly link neural dynamics to behavior of microsaccades. These results indicate strongly that the cascading adaptations play an important role in the study of microsaccades. Our work may be useful for further investigations of the microsaccadic behavioral properties and of the underlying neural dynamical mechanisms responsible for the behavioral properties.

  5. Chemical, mass spectrometric, and spectrochemical analysis of, and physical tests on, beryllium oxide powder

    SciTech Connect

    Not Available

    1981-01-01

    Beryllium oxide is used in the fabrication of nuclear components. In order to be suitable for this purpose, the material must meet certain criteria for impurity content and physical properties. The analytical and physical testing procedures in this standard are designed to show whether or not a given material meets accepted specifications. Test methods described in detail are: total carbon by the combustion-thermal conductivity method; iron by colorimetric (orthophenanthroline) method; nitride nitrogen by the micro Kjeldahl method; chloride by nephelometry; lithium by atomic absorption spectrophotometry; sulfur by combustion-iodometric titration method; beryllium oxide in beryllium oxide powders by impurity correction method; trace elements by the complete-burning spectrochemical method; impurity elements by a spark-source mass spectrographic method; density by toluene displacement method; density (pour and tap) by the tap-pak volumetric method; particle size distribution analysis by the coulter counter method; sieve analysis; bulk and real densities, porosity, and pore size-pore volume distribution mercury-penetration porosimetry; surface area by nitrogen absorption method. (JMT)

  6. Mass

    SciTech Connect

    Quigg, Chris

    2007-12-05

    In the classical physics we inherited from Isaac Newton, mass does not arise, it simply is. The mass of a classical object is the sum of the masses of its parts. Albert Einstein showed that the mass of a body is a measure of its energy content, inviting us to consider the origins of mass. The protons we accelerate at Fermilab are prime examples of Einsteinian matter: nearly all of their mass arises from stored energy. Missing mass led to the discovery of the noble gases, and a new form of missing mass leads us to the notion of dark matter. Starting with a brief guided tour of the meanings of mass, the colloquium will explore the multiple origins of mass. We will see how far we have come toward understanding mass, and survey the issues that guide our research today.

  7. Mass

    SciTech Connect

    Chris Quigg

    2007-12-05

    In the classical physics we inherited from Isaac Newton, mass does not arise, it simply is. The mass of a classical object is the sum of the masses of its parts. Albert Einstein showed that the mass of a body is a measure of its energy content, inviting us to consider the origins of mass. The protons we accelerate at Fermilab are prime examples of Einsteinian matter: nearly all of their mass arises from stored energy. Missing mass led to the discovery of the noble gases, and a new form of missing mass leads us to the notion of dark matter. Starting with a brief guided tour of the meanings of mass, the colloquium will explore the multiple origins of mass. We will see how far we have come toward understanding mass, and survey the issues that guide our research today.

  8. Summary of the results of the LISA-Pathfinder Test Mass release

    NASA Astrophysics Data System (ADS)

    Zanoni, C.; Bortoluzzi, D.; Conklin, J. W.; Köker, I.; Seutchat, B.; Vitale, S.

    2015-05-01

    The challenging goal of LISA-Pathfinder in terms of maximum non-gravitational forces applied on the test mass poses tight constraints on the design of the Gravitational Reference Sensor. In particular, large gaps (3-4 mm) must exist between the test mass and its housing and any system there located must be either gold coated or made of a gold-based material. As a consequence, a significant adhesion may arise between the test mass and the mechanism designed to cage it during the spacecraft launch and to release it to free-fall. The criticality of the latter phase is enhanced by the control force authority exerted to the test mass by the surrounding electrodes. Such a force is limited by the large gaps (order of μN). Since the expected adhesion force between the test mass and its holding devices is much larger than the force authority, a dynamic release must be realized. However, following this procedure adhesion converts into test mass velocity, which can be controlled by the capacitive force only if it is smaller than 5 μm/s. At the University of Trento (Italy) the Transferred Momentum Measurement Facility has been designed and developed to measure the impulse produced by metallic adhesion upon quick rupture, in representative conditions of the LISA-Pathfinder test mass release to free-fall. Large sets of data have been collected and a mathematical model of the in-flight release dynamics has been developed, in order to estimate the test mass release velocity. A summary of the results is presented, together with an overview of the recent developments and a prediction of the in-flight performance.

  9. Mass transport properties of Pu/DT mixtures from orbital free molecular dynamics simulations

    SciTech Connect

    Kress, Joel David; Ticknor, Christopher; Collins, Lee A.

    2015-09-16

    Mass transport properties (shear viscosity and diffusion coefficients) for Pu/DT mixtures were calculated with Orbital Free Molecular Dynamics (OFMD). The results were fitted to simple functions of mass density (for ρ=10.4 to 62.4 g/cm3) and temperature (for T=100 up to 3,000 eV) for Pu/DT mixtures consisting of 100/0, 25/75, 50/50, and 75/25 by number.

  10. Psychometric properties of the Pyramids and Palm Trees Test.

    PubMed

    Klein, Liesa A; Buchanan, Jeffrey A

    2009-10-01

    The Pyramids and Palm Trees Test (PPT) is a nonverbal measure of semantic memory that has been frequently used in previous aphasia, agnosia, and dementia research. Very little psychometric information regarding the PPT is available. The purpose of this study was to investigate the psychometric properties of the PPT in a population of healthy college students. Results indicated that the PPT achieved poor test-retest reliability, failed to obtain adequate internal consistency, and demonstrated poor convergent validity, but showed acceptable discriminant validity. The results of this study suggest that the PPT lacks acceptable reliability and validity for use with a college student population.

  11. Methodology for Mechanical Property Testing of Fuel Cladding Using a Expanded Plug Wedge Test

    SciTech Connect

    Jiang, Hao; Wang, Jy-An John

    2014-01-01

    An expanded plug method was developed earlier for determining the tensile properties of irradiated fuel cladding. This method tests fuel rod cladding ductility by utilizing an expandable plug to radially stretch a small ring of irradiated cladding material. The circumferential or hoop strain is determined from the measured diametrical expansion of the ring. A developed procedure is used to convert the load circumferential strain data from the ring tests into material pseudo-stress-strain curves, from which material properties of the cladding can be extracted. However, several deficiencies existed in this expanded-plug test that can impact the accuracy of test results, such as that the large axial compressive stress resulted from the expansion plug test can potentially induce the shear failure mode of the tested specimen. Moreover, highly nonuniform stress and strain distribution in the deformed clad gage section and significant compressive stresses, induced by bending deformation due to clad bulging effect, will further result in highly nonconservative estimates of the mechanical properties for both strength and ductility of the tested clad. To overcome the aforementioned deficiencies associated with the current expansion plug test, systematic studies have been conducted. By optimizing the specific geometry designs, selecting the appropriate material for the expansion plug, and adding new components into the testing system, a modified expansion plug testing protocol has been developed. A general procedure was also developed to determine the hoop stress in the tested ring specimen. A scaling factor, -factor, was used to convert the ring load Fring into hoop stress , and is written as _ = F_ring/tl , where t is the clad thickness and l is the clad length. The generated stress-strain curve agrees well with the associated tensile test data in both elastic and plastic deformation regions.

  12. Mass property identification - A comparison study between extended Kalman filter and neuro-filter approaches

    NASA Technical Reports Server (NTRS)

    Lam, Quang; Chipman, Richard; Sunkel, John

    1991-01-01

    Two algorithms, extended Kalman filter and neuro-filter, are formulated to perform mass property identification for the Space Station Freedom. Control moment gyros that are part of the Station's basic momentum management system are chosen to provide input excitation in the form of applied torques. These torques together with the measured angular body rate responses are supplied to the filters. From these data, both algorithms are shown to accurately identify the station mass properties when excitation levels are high and balanced between axes. The neuro-filter, however, is shown to be more robust and to perform well even with weakly persistent, unbalanced signals contaminated with noise.

  13. Dynamic Modeling Accuracy Dependence on Errors in Sensor Measurements, Mass Properties, and Aircraft Geometry

    NASA Technical Reports Server (NTRS)

    Grauer, Jared A.; Morelli, Eugene A.

    2013-01-01

    A nonlinear simulation of the NASA Generic Transport Model was used to investigate the effects of errors in sensor measurements, mass properties, and aircraft geometry on the accuracy of dynamic models identified from flight data. Measurements from a typical system identification maneuver were systematically and progressively deteriorated and then used to estimate stability and control derivatives within a Monte Carlo analysis. Based on the results, recommendations were provided for maximum allowable errors in sensor measurements, mass properties, and aircraft geometry to achieve desired levels of dynamic modeling accuracy. Results using other flight conditions, parameter estimation methods, and a full-scale F-16 nonlinear aircraft simulation were compared with these recommendations.

  14. Modeling and Simulation of a Spinning Spherical Test Mass for Modular Gravitational Reference Sensor

    NASA Astrophysics Data System (ADS)

    Sun, Ke-Xun; Conklin, John; Allen, Graham; Buchman, Sasha; Byer, Robert; Debra, Dan

    In a drag-free spacecraft, the spacecraft computer uses input from displacement sensors to fly at a constant distance from a free- floating test mass inside the spcaecraft. Optical sensors offer higher resolution and zero stiffness compared to capacitive sensors, but the small spot size makes them much more sensitive to test mass surface irregularities. Except for these residual geometric irregularities, the sphere is orientation invariant. Consequently, with a spherical test mass, we can eliminate electrostatic suspension for orientation control, which can cause unwanted forcing of the test mass. Spinning a sphere spectrally shifts the surface irregularities as well as the mass center offset from the geometric center out of the desired sensing band. Given that the outof-roundness and mass center offset of a sphere can be 105 larger than the desired resolution, special care must be taken to avoid aliasing spin frequency information into the science band. An analytical model for the output of a drag-free sensor using a spherical test mass including all first order contributions is developed. With this model, we evaluate systematic errors in the mass center measurement due to geometric variations which place requirements on spacecraft attitude and test mass dynamics. We also present a fast and reliable algorithm for recovering the mass center location and spin frequency of the test mass, in real-time, to picometer level from the sensor data. This algorithm involves fitting and removing the spin harmonics from the sensor output and uses the phase of the fitted harmonics to track the test mass spin frequency in real-time. A numerical simulation is developed to compared this algorithm to other possible data processing methods including a straight-forward tuned digital filter and a surface mapping algorithm. The computational complexity of each algorithm is analyzed since in there is limited CPU power on a satellite, and there is insufficient bandwidth for transmitting

  15. Analysis of Marshall test behavior with triaxial test determined material properties

    SciTech Connect

    Low, Boonhwee; Tan, Siewann; Fwa, Tienfang )

    1993-01-01

    The Marshall test is one of the most common methods used for mix design and quality control of asphalt concrete mixtures. However, this method is empirical in nature and does not provide fundamental engineering properties. Fundamental engineering properties provide a basis for rational analysis and design of asphalt concrete pavements. The triaxial test method described in this paper allows engineering properties such as internal angle of friction, [phi], cohesion, c, and elastic modulus, E, to be determined. The method of specimen preparation and the triaxial test setup are briefly described. A numerical simulation of the Marshall test is performed using a plane-stress finite element analysis with triaxial test determined properties as input parameters. A constitutive plasticity model based on the Drucker-Prager yield condition is used to describe the elasto-plastic behavior of the specimen. Analysis shows that the model very well describes the deformation progression before failure and can predict experimental Marshall stability value very closely. There is some underprediction of the Marshall flow, probably due to the idealization of an elastic-perfectly-plastic stress-strain relationship for asphalt concrete.

  16. Properties and testing of loose-fill cellulosic insulation

    SciTech Connect

    Yarbrough, D.W.; McElroy, D.L.; Harris, W.W.

    1982-02-01

    New methods for measuring thermal resistance, permeability to air, settled density, and compressibility of loose-fill cellulosic insulation (LFCI) are described. The resultant property measurements are discussed. Chemical analyses were completed on the LFCI in the sampling. The results represent a first attempt to assess the variability of products and fire-retardant formulations. Chemical characteristics have been compared with test performance. Compounds present in the insulations tested were not identified directly but were deduced from elemental analyses. The amount of water-soluble fire retardant in LFCI products were found to vary from 14 to 36 wt %. Formulations containing from one to five separate compounds were identified. It was observed that products containing above 20 wt % fire-retardant chemicals had the highest acceptance (pass) rate for the combustion tests specified by federal specification HH-I-515D. The overall performance of the LFCI materials tested was poor as measured by HH-I-515D methods. Results for the important smoldering-combustion test yielded passing rates from 30.6 to 62.7%. Seventy-five percent of the LFCI specimens passed the radiant panel test. The percentage of the sample that passed both the smoldering-combustion and the radiant panel test ranged from 42 to 50%. The blower-cyclone-shaker (BCS) test for settled density has been subjected to continued interlaboratory evaluation.Laboratory results have been compared with field measurements to determine the applicability of the test as a predictor. The average of the results of the BCS Test compares very closely (<1%) with field data from four cities. Individual materials, however, can show differences between field and laboratory results of up to 20%.

  17. TESTING THE ASTEROSEISMIC MASS SCALE USING METAL-POOR STARS CHARACTERIZED WITH APOGEE AND KEPLER

    SciTech Connect

    Epstein, Courtney R.; Johnson, Jennifer A.; Tayar, Jamie; Pinsonneault, Marc; Elsworth, Yvonne P.; Chaplin, William J.; Shetrone, Matthew; Mosser, Benoît; Hekker, Saskia; Harding, Paul; Silva Aguirre, Víctor; Basu, Sarbani; Beers, Timothy C.; Bizyaev, Dmitry; Bedding, Timothy R.; Frinchaboy, Peter M.; García, Rafael A.; and others

    2014-04-20

    Fundamental stellar properties, such as mass, radius, and age, can be inferred using asteroseismology. Cool stars with convective envelopes have turbulent motions that can stochastically drive and damp pulsations. The properties of the oscillation frequency power spectrum can be tied to mass and radius through solar-scaled asteroseismic relations. Stellar properties derived using these scaling relations need verification over a range of metallicities. Because the age and mass of halo stars are well-constrained by astrophysical priors, they provide an independent, empirical check on asteroseismic mass estimates in the low-metallicity regime. We identify nine metal-poor red giants (including six stars that are kinematically associated with the halo) from a sample observed by both the Kepler space telescope and the Sloan Digital Sky Survey-III APOGEE spectroscopic survey. We compare masses inferred using asteroseismology to those expected for halo and thick-disk stars. Although our sample is small, standard scaling relations, combined with asteroseismic parameters from the APOKASC Catalog, produce masses that are systematically higher (<ΔM > =0.17 ± 0.05 M {sub ☉}) than astrophysical expectations. The magnitude of the mass discrepancy is reduced by known theoretical corrections to the measured large frequency separation scaling relationship. Using alternative methods for measuring asteroseismic parameters induces systematic shifts at the 0.04 M {sub ☉} level. We also compare published asteroseismic analyses with scaling relationship masses to examine the impact of using the frequency of maximum power as a constraint. Upcoming APOKASC observations will provide a larger sample of ∼100 metal-poor stars, important for detailed asteroseismic characterization of Galactic stellar populations.

  18. Ground testing and flight demonstration of charge management of insulated test masses using UV-LED electron photoemission

    NASA Astrophysics Data System (ADS)

    Saraf, Shailendhar; Buchman, Sasha; Balakrishnan, Karthik; Lui, Chin Yang; Soulage, Michael; Faied, Dohy; Hanson, John; Ling, Kuok; Jaroux, Belgacem; Suwaidan, Badr Al; AlRashed, Abdullah; Al-Nassban, Badr; Alaqeel, Faisal; Harbi, Mohammed Al; Salamah, Badr Bin; Othman, Mohammed Bin; Qasim, Bandar Bin; Alfauwaz, Abdulrahman; Al-Majed, Mohammed; DeBra, Daniel; Byer, Robert

    2016-12-01

    The UV-LED mission demonstrates the precise control of the potential of electrically isolated test masses. Test mass charge control is essential for the operation of space accelerometers and drag-free sensors which are at the core of geodesy, aeronomy and precision navigation missions as well as gravitational wave experiments and observatories. Charge management using photoelectrons generated by the 254 nm UV line of Hg was first demonstrated on Gravity Probe B and is presently part of the LISA Pathfinder technology demonstration. The UV-LED mission and prior ground testing demonstrates that AlGaN UVLEDs operating at 255 nm are superior to Hg lamps because of their smaller size, lower power draw, higher dynamic range, and higher control authority. We show laboratory data demonstrating the effectiveness and survivability of the UV-LED devices and performance of the charge management system. We also show flight data from a small satellite experiment that was one of the payloads on KACST’s SaudiSat-4 mission that demonstrates ‘AC charge control’ (UV-LEDs and bias are AC modulated with adjustable relative phase) between a spherical test mass and its housing. The result of the mission brings the UV-LED device Technology Readiness Level (TRL) to TRL-9 and the charge management system to TRL-7. We demonstrate the ability to control the test mass potential on an 89 mm diameter spherical test mass over a 20 mm gap in a drag-free system configuration, with potential measured using an ultra-high impedance contact probe. Finally, the key electrical and optical characteristics of the UV-LEDs showed less than 7.5% change in performance after 12 months in orbit.

  19. The Relationship between Lean Mass and Contractile Properties of the Quadriceps in Elderly and Young Adults.

    PubMed

    Mau-Moeller, Anett; Bruhn, Sven; Bader, Rainer; Behrens, Martin

    2015-01-01

    Aging is associated with a loss of muscle mass (sarcopenia) and function. The twitch torque evoked by supramaximal electrical stimulation of peripheral nerves has been frequently used to analyse age-related modulations at the skeletal muscle level, such as changes in muscle mass. However, only one study has investigated the association between twitch contractile properties and skeletal muscle mass. A significant positive correlation between cross-sectional area and twitch parameters was found for the plantar flexors in young adults when using supramaximal doublet stimulation. It remains unclear whether this relationship exists for the quadriceps in elderly and young subjects when using single and doublet stimulation. The aim of the present study was to investigate the relationship between the lean mass of the thigh and evoked twitch properties of the quadriceps using single and doublet stimulation in two age groups. Fifteen young (aged 25.3 ± 3.6 years) and 15 elderly (aged 69.6 ± 3.1 years) subjects were recruited to participate in this study. The lean mass of the thigh was measured by dual-energy X-ray absorptiometry. Supramaximal single and doublet electrical stimulation was used to assess the contractile properties of the quadriceps. We observed no significant associations between lean mass and contractile properties when using single stimulation. Significant positive correlations were shown between lean mass and peak twitch torque evoked by doublet stimulation in young (r = 0.56; p = 0.030) and elderly (r = 0.54; p = 0.040) subjects. The analysis of twitch time and slope parameters demonstrated no significant correlations with lean mass. The peak twitch torque evoked by doublet electrical stimulation seems to be an appropriate measure to assess modulations in muscle mass in elderly and young subjects. The use of supramaximal single stimulation and the analysis of time and slope parameters may not be recommended for estimating changes in muscle mass

  20. Properties of bootstrap tests for N-of-1 studies.

    PubMed

    Lin, Sharon X; Morrison, Leanne; Smith, Peter W F; Hargood, Charlie; Weal, Mark; Yardley, Lucy

    2016-11-01

    N-of-1 study designs involve the collection and analysis of repeated measures data from an individual not using an intervention and using an intervention. This study explores the use of semi-parametric and parametric bootstrap tests in the analysis of N-of-1 studies under a single time series framework in the presence of autocorrelation. When the Type I error rates of bootstrap tests are compared to Wald tests, our results show that the bootstrap tests have more desirable properties. We compare the results for normally distributed errors with those for contaminated normally distributed errors and find that, except when there is relatively large autocorrelation, there is little difference between the power of the parametric and semi-parametric bootstrap tests. We also experiment with two intervention designs: ABAB and AB, and show the ABAB design has more power. The results provide guidelines for designing N-of-1 studies, in the sense of how many observations and how many intervention changes are needed to achieve a certain level of power and which test should be performed. © 2016 The Authors British Journal of Mathematical and Statistical Psychology published by John Wiley & Sons Ltd on behalf of British Psychological Society.

  1. Furniture wood wastes: experimental property characterisation and burning tests.

    PubMed

    Tatàno, Fabio; Barbadoro, Luca; Mangani, Giovanna; Pretelli, Silvia; Tombari, Lucia; Mangani, Filippo

    2009-10-01

    Referring to the industrial wood waste category (as dominant in the provincial district of Pesaro-Urbino, Marche Region, Italy), this paper deals with the experimental characterisation and the carrying out of non-controlled burning tests (at lab- and pilot-scale) for selected "raw" and primarily "engineered" ("composite") wood wastes. The property characterisation has primarily revealed the following aspects: potential influence on moisture content of local weather conditions at outdoor wood waste storage sites; generally, higher ash contents in "engineered" wood wastes as compared with "raw" wood wastes; and relatively high energy content values of "engineered" wood wastes (ranging on the whole from 3675 to 5105 kcal kg(-1) for HHV, and from 3304 to 4634 kcal kg(-1) for LHV). The smoke qualitative analysis of non-controlled lab-scale burning tests has primarily revealed: the presence of specific organic compounds indicative of incomplete wood combustion; the presence exclusively in "engineered" wood burning tests of pyrroles and amines, as well as the additional presence (as compared with "raw" wood burning) of further phenolic and containing nitrogen compounds; and the potential environmental impact of incomplete industrial wood burning on the photochemical smog phenomenon. Finally, non-controlled pilot-scale burning tests have primarily given the following findings: emission presence of carbon monoxide indicative of incomplete wood combustion; higher nitrogen oxide emission values detected in "engineered" wood burning tests as compared with "raw" wood burning test; and considerable generation of the respirable PM(1) fraction during incomplete industrial wood burning.

  2. 76 FR 82129 - Medical Devices; Ovarian Adnexal Mass Assessment Score Test System; Labeling; Black Box Restrictions

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-30

    ..., or as a test to determine whether or not to proceed with surgery. DATES: Effective Date: January 30... likelihood that an adnexal pelvic mass in a woman for whom surgery is planned, is malignant. The test is for... identification of patients whose gynecologic surgery requires oncology expertise and resources. B....

  3. VAMP: A computer program for calculating volume, area, and mass properties of aerospace vehicles

    NASA Technical Reports Server (NTRS)

    Norton, P. J.; Glatt, C. R.

    1974-01-01

    A computerized procedure developed for analyzing aerospace vehicles evaluates the properties of elemental surface areas with specified thickness by accumulating and combining them with arbitrarily specified mass elements to form a complete evaluation. Picture-like images of the geometric description are capable of being generated.

  4. Aerosol properties and radiative forcing for three air masses transported in Summer 2011 to Sopot, Poland

    NASA Astrophysics Data System (ADS)

    Rozwadowska, Anna; Stachlewska, Iwona S.; Makuch, P.; Markowicz, K. M.; Petelski, T.; Strzałkowska, A.; Zieliński, T.

    2013-05-01

    Properties of atmospheric aerosols and solar radiation reaching the Earth's surface were measured during Summer 2011 in Sopot, Poland. Three cloudless days, characterized by different directions of incoming air-flows, which are typical transport pathways to Sopot, were used to estimate a radiative forcing due to aerosols present in each air mass.

  5. Controlling false positive rates in mass-multivariate tests for electromagnetic responses.

    PubMed

    Barnes, Gareth R; Litvak, Vladimir; Brookes, Matt J; Friston, Karl J

    2011-06-01

    We address the problem of controlling false positive rates in mass-multivariate tests for electromagnetic responses in compact regions of source space. We show that mass-univariate thresholds based on sensor level multivariate thresholds (approximated using Roy's union-intersection principle) are unduly conservative. We then consider a Bonferroni correction for source level tests based on the number of unique lead-field extrema. For a given source space, the sensor indices corresponding to the maxima and minima (for each dipolar lead field) are listed, and the number of unique extrema is given by the number of unique pairs in this list. Using a multivariate beamformer formulation, we validate this heuristic against empirical permutation thresholds for mass-univariate and mass-multivariate tests (of induced and evoked responses) for a variety of source spaces, using simulated and real data. We also show that the same approximations hold when dealing with a cortical manifold (rather than a volume) and for mass-multivariate minimum norm solutions. We demonstrate that the mass-multivariate framework is not restricted to tests on a single contrast of effects (cf, Roy's maximum root) but also accommodates multivariate effects (cf, Wilk's lambda). Copyright © 2011 Elsevier Inc. All rights reserved.

  6. Controlling false positive rates in mass-multivariate tests for electromagnetic responses

    PubMed Central

    Barnes, Gareth R.; Litvak, Vladimir; Brookes, Matt J.; Friston, Karl J.

    2011-01-01

    We address the problem of controlling false positive rates in mass-multivariate tests for electromagnetic responses in compact regions of source space. We show that mass-univariate thresholds based on sensor level multivariate thresholds (approximated using Roy's union–intersection principle) are unduly conservative. We then consider a Bonferroni correction for source level tests based on the number of unique lead-field extrema. For a given source space, the sensor indices corresponding to the maxima and minima (for each dipolar lead field) are listed, and the number of unique extrema is given by the number of unique pairs in this list. Using a multivariate beamformer formulation, we validate this heuristic against empirical permutation thresholds for mass-univariate and mass-multivariate tests (of induced and evoked responses) for a variety of source spaces, using simulated and real data. We also show that the same approximations hold when dealing with a cortical manifold (rather than a volume) and for mass-multivariate minimum norm solutions. We demonstrate that the mass-multivariate framework is not restricted to tests on a single contrast of effects (cf, Roy's maximum root) but also accommodates multivariate effects (cf, Wilk's lambda). PMID:21396458

  7. Testing psychometric properties of the 30-item general health questionnaire.

    PubMed

    Klainin-Yobas, Piyanee; He, Hong-Gu

    2014-01-01

    This study aimed to evaluate the psychometric properties of the General Health Questionnaire (GHQ-30) given conflicting findings in the literature. A cross-sectional, nonexperimental research was used with a convenience sample of 271 American female health care professionals. Data were collected by using self-reported questionnaires. A series of exploratory factor analyses (EFAs), confirmatory factor analyses (CFAs), and structural equation modeling (SEM) were performed to examine underlying dimensions of the GHQ-30. Results from EFAs and CFAs revealed the three-factor composition (positive affect, anxiety, and depressed mood). All factor loadings were statistically significant, and one pair of error variance was allowed to be correlated. All factors contained questionnaire items with acceptable face validity and demonstrated good internal consistency reliability. Results from SEM further confirmed underlying constructs of the scale. To our knowledge, this is the first study that extensively tested the psychometric properties of the GHQ-30, taking both statistical and substantive issues into consideration.

  8. A non-contacting vertical alignment system for mass properties measuring instruments

    SciTech Connect

    James, G.H. III; Suazo, J.E.; Varga, R.C.

    1993-11-01

    A non-contact system for alignment of objects on mass properties measuring instruments is described. Test parts can be aligned to within the capabilities of the user and the fixture to make the adjustments. The current implementation can align objects to less than .001 inches at two points with final requested adjustments of a few ten-thousands of an inch. The non-contact capability allows the alignment of objects which are too compliant or fragile for traditional contacting measurement methods. Also, this system allows the definition of a reference axis on objects which are not perfectly symmetric. The reference axis is defined at the top of the object by an appropriate marker and defined at the bottom by a best fit circle through the surface at a specified height. A general description of the hardware, procedures, and results are presented for the non-user. Appendices which contain a complete description of the software, usage, and mathematical implementation are provided for the reader who is interested in using or further developing the system.

  9. Effects of functional group mass variance on vibrational properties and thermal transport in graphene

    DOE PAGES

    Lindsay, L.; Kuang, Y.

    2017-03-13

    Intrinsic thermal resistivity critically depends on features of phonon dispersions dictated by harmonic interatomic forces and masses. We present the effects of functional group mass variance on vibrational properties and thermal conductivity (κ ) of functionalized graphene from first principles calculations. We also use graphane, a buckled graphene backbone with covalently bonded Hydrogen atoms on both sides, as the base material and vary the mass of the Hydrogen atoms to simulate the effect of mass variance from other functional groups. We find non-monotonic behavior of κ with increasing mass of the functional group and an unusual cross-over from acoustic-dominated tomore » optic-dominated thermal transport behavior. We connect this cross-over to changes in the phonon dispersion with varying mass which suppress acoustic phonon velocities, but also give unusually high velocity optic modes. Further, we show that out-of-plane acoustic vibrations contribute significantly more to thermal transport than in-plane acoustic modes despite breaking of a reflection symmetry based scattering selection rule responsible for their large contributions in graphene. Our work demonstrates the potential for manipulation and engineering of thermal transport properties in two dimensional materials toward targeted applications.« less

  10. Impact of thermal energy storage properties on solar dynamic space power conversion system mass

    NASA Technical Reports Server (NTRS)

    Juhasz, Albert J.; Coles-Hamilton, Carolyn E.; Lacy, Dovie E.

    1987-01-01

    A 16 parameter solar concentrator/heat receiver mass model is used in conjunction with Stirling and Brayton Power Conversion System (PCS) performance and mass computer codes to determine the effect of thermal energy storage (TES) material property changes on overall PCS mass as a function of steady state electrical power output. Included in the PCS mass model are component masses as a function of thermal power for: concentrator, heat receiver, heat exchangers (source unless integral with heat receiver, heat sink, regenerator), heat engine units with optional parallel redundancy, power conditioning and control (PC and C), PC and C radiator, main radiator, and structure. Critical TES properties are: melting temperature, heat of fusion, density of the liquid phase, and the ratio of solid-to-liquid density. Preliminary results indicate that even though overalll system efficiency increases with TES melting temperature up to 1400 K for concentrator surface accuracies of 1 mrad or better, reductions in the overall system mass beyond that achievable with lithium fluoride (LiF) can be accomplished only if the heat of fusion is at least 800 kJ/kg and the liquid density is comparable to that of LiF (1880 kg/cu m.

  11. Impact of thermal energy storage properties on solar dynamic space power conversion system mass

    NASA Technical Reports Server (NTRS)

    Juhasz, Albert J.; Coles-Hamilton, Carolyn E.; Lacy, Dovie E.

    1987-01-01

    A 16 parameter solar concentrator/heat receiver mass model is used in conjunction with Stirling and Brayton Power Conversion System (PCS) performance and mass computer codes to determine the effect of thermal energy storage (TES) material property changes on overall PCS mass as a function of steady state electrical power output. Included in the PCS mass model are component masses as a function of thermal power for: concentrator, heat receiver, heat exchangers (source unless integral with heat receiver, heat sink, regenerator), heat engine units with optional parallel redundancy, power conditioning and control (PC and C), PC and C radiator, main radiator, and structure. Critical TES properties are: melting temperature, heat of fusion, density of the liquid phase, and the ratio of solid-to-liquid density. Preliminary results indicate that even though overall system efficiency increases with TES melting temperature up to 1400 K for concentrator surface accuracies of 1 mrad or better, reductions in the overall system mass beyond that achievable with lithium fluoride (LiF) can be accomplished only if the heat of fusion is at least 800 kJ/kg and the liquid density is comparable to that of LiF (1800 kg/cu m).

  12. Impact of thermal energy storage properties on solar dynamic space power conversion system mass

    NASA Technical Reports Server (NTRS)

    Juhasz, Albert J.; Coles-Hamilton, Carolyn E.; Lacy, Dovie E.

    1987-01-01

    A 16 parameter solar concentrator/heat receiver mass model is used in conjunction with Stirling and Brayton Power Conversion System (PCS) performance and mass computer codes to determine the effect of thermal energy storage (TES) material property changes on overall PCS mass as a function of steady state electrical power output. Included in the PCS mass model are component masses as a function of thermal power for: concentrator, heat receiver, heat exchangers (source unless integral with heat receiver, heat sink, regenerator), heat engine units with optional parallel redundancy, power conditioning and control (PC and C), PC and C radiator, main radiator, and structure. Critical TES properties are: melting temperature, heat of fusion, density of the liquid phase, and the ratio of solid-to-liquid density. Preliminary results indicate that even though overall system efficiency increases with TES melting temperature up to 1400 K for concentrator surface accuracies of 1 mrad or better, reductions in the overall system mass beyond that achievable with lithium fluoride (LiF) can be accomplished only if the heat of fusion is at least 800 kJ/kg and the liquid density is comparable to that of LiF (1800 kg/cu m).

  13. Effects of functional group mass variance on vibrational properties and thermal transport in graphene

    NASA Astrophysics Data System (ADS)

    Lindsay, L.; Kuang, Y.

    2017-03-01

    Intrinsic thermal resistivity critically depends on features of phonon dispersions dictated by harmonic interatomic forces and masses. Here we present the effects of functional group mass variance on vibrational properties and thermal conductivity (κ ) of functionalized graphene from first-principles calculations. We use graphane, a buckled graphene backbone with covalently bonded hydrogen atoms on both sides, as the base material and vary the mass of the hydrogen atoms to simulate the effect of mass variance from other functional groups. We find nonmonotonic behavior of κ with increasing mass of the functional group and an unusual crossover from acoustic-dominated to optic-dominated thermal transport behavior. We connect this crossover to changes in the phonon dispersion with varying mass which suppress acoustic phonon velocities, but also give unusually high velocity optic modes. Further, we show that out-of-plane acoustic vibrations contribute significantly more to thermal transport than in-plane acoustic modes despite breaking of a reflection-symmetry-based scattering selection rule responsible for their large contributions in graphene. This work demonstrates the potential for manipulation and engineering of thermal transport properties in two-dimensional materials toward targeted applications.

  14. Properties and Star Formation Histories of Intermediate Redshift Dwarf Low-Mass Star-Forming Galaxies

    NASA Astrophysics Data System (ADS)

    Rodríguez-Muñoz, L.; Gallego, J.; Pacifici, C.; Tresse, L.; Charlot, S.; Gil de Paz, A.; Barro, G.; Villar, V.

    2017-03-01

    The epoch when low-mass star-forming galaxies (LMSFGs) form the bulk of their stellar mass is uncertain. While some models predict an early formation, others favor a delayed scenario until later ages of the Universe. We present improved constraints on the physical properties and star formation histories (SFHs) of a sample of intermediate redshift LMSFGs selected by their stellar mass or blue-compact-dwarf-like properties. Our work takes advantage of the deep UV-to-FIR photometric coverage available on the Extended-Chandra Deep Field South and our own dedicated deep VLT/VIMOS optical spectroscopy programs. On the one hand, we estimate the stellar mass (M_{*}), star formation rate (SFR), and SFH of each galaxy modeling its spectral energy distribution. We use a novel approach by Pacifici et al. 2012, that (1) consistently combines photometric (broad-band) and spectroscopic (emission line fluxes and equivalent widths) data, and (2) uses physically-motivated SFHs with non-uniform variations of the SFR as a function of time. On the other hand, we characterize the properties of their interstellar medium by analyzing the emission line features visible in the VIMOS spectroscopy. The final sample includes 91 spectroscopically confirmed LMSFGs (7.3 ≤ logM_{*}/M_{⊙} ≤ 9.5) at 0.3 mass, and high specific-SFR. Furthermore, they are characterized by strong emission lines, low metallicity, and an enhanced level of excitation. Our selection criterion based on mass gathers galaxies within a wide range of properties, and possibly, different evolutionary stages. Despite the individual differences, the average SFH that we obtain suggests a late and fast (˜2 Gyr prior their observation) assembly scenario for this type of system.

  15. Psychometric properties of 2-minute walk test: a systematic review.

    PubMed

    Pin, Tamis W

    2014-09-01

    To systematically review the psychometric evidence on the 2-minute walk test (2MWT). Electronic searches of databases including MEDLINE, CINAHL, Academic Search Premier, SPORTDiscus, PsycINFO, EMBASE, the Cochrane Library, and DARE were done until February 2014 using a combination of subject headings and free texts. Studies were included if psychometric properties of the 2MWT were (1) evaluated; (2) written as full reports; and (3) published in English language peer-reviewed journals. A modified consensus-based standard for the selection of health measurement instruments checklist was used to rate the methodological quality of the included studies. A quality assessment for statistical outcomes was used to assess the measurement properties of the 2MWT. Best-evidence synthesis was collated from 25 studies of 14 patient groups. Only 1 study was found that examined the 2MWT in the pediatric population. The testing procedures of the 2MWT varied across the included studies. Reliability, validity (construct and criterion), and responsiveness of the 2MWT also varied across different patient groups. Moderate to strong evidence was found for reliability, convergent validity, discriminative validity, and responsiveness of the 2MWT in frail elderly patients. Moderate to strong evidence for reliability, convergent validity, and responsiveness was found in adults with lower limb amputations. Moderate to strong evidence for validity (convergent and discriminative) was found in adults who received rehabilitation after hip fractures or cardiac surgery. Limited evidence for the psychometric properties of the 2MWT was found in other population groups because of methodological flaws. There is inadequate breadth and depth of psychometric evidence of the 2MWT for clinical and research purposes-specifically, minimal clinically important changes and responsiveness. More good-quality studies are needed, especially in the pediatric population. Consensus on standardized testing procedures of

  16. The different decomposition properties of diazolidinyl urea in cosmetics and patch test materials.

    PubMed

    Doi, Takahiro; Kajimura, Keiji; Taguchi, Shuzo

    2011-08-01

    Diazolidinyl urea is a formaldehyde-releasing compound that releases formaldehyde through its decomposition. However, there have been few reports about the decomposition properties of diazolidinyl urea in cosmetics and patch test materials. The aim of this study was to show how diazolidinyl urea decomposes in cosmetics and patch test vehicles, and to determine which cosmetic compounds should be evaluated in patch test studies of diazolidinyl urea. We fractionated diazolidinyl urea-dissolving buffers or diazolidinyl urea-containing cosmetics with high-performance liquid chromatography-photodiode array detector (HPLC-PDA), and characterized them in liquid chromatography-mass spectrometry (LC-MS) and (1) H-nuclear magnetic resonance studies. Diazolidinyl urea-containing cosmetics and diazolidinyl urea patch test materials were also analysed with HPLC-PDA and LC-MS. Diazolidinyl urea was decomposed to (4-hydroxymethyl-2,5-dioxo-imidazolidine-4-yl)-urea (HU) and (3,4-bis-hydroxymethyl-2,5-dioxo-imidazolidine-4-yl)-urea (3,4-BHU) in most of the cosmetic samples tested. The peak patterns of the patch test materials analysed with the HPLC-PDA were different from those of the cosmetic samples. CONCLUSIONS. The diazolidinyl urea-derived decomposition products differed between the cosmetics and patch test preparations. To test the contact sensitivity of the diazolidinyl urea present in cosmetics, patch tests with HU and 3,4-BHU in petrolatum should be performed. © 2011 John Wiley & Sons A/S.

  17. Physical properties of high-mass clumps in different stages of evolution

    NASA Astrophysics Data System (ADS)

    Giannetti, A.; Brand, J.; Sánchez-Monge, Á.; Fontani, F.; Cesaroni, R.; Beltrán, M. T.; Molinari, S.; Dodson, R.; Rioja, M. J.

    2013-08-01

    Context. The details of the process of massive star formation are still elusive. A complete characterization of the first stages of the process from an observational point of view is needed to constrain theories on the subject. In the past 20 years we have made a thorough investigation of colour-selected IRAS sources over the whole sky. The sources in the northern hemisphere were studied in detail and used to derive an evolutionary sequence based on their spectral energy distribution. Aims: To investigate the first stages of the process of high-mass star formation, we selected a sample of massive clumps previously observed with the Swedish-ESO Submillimetre Telescope at 1.2 mm and with the ATNF Australia Telescope Compact Array at 1.3 cm. We want to characterize the physical conditions in such sources, and test whether their properties depend on the evolutionary stage of the clump. Methods: With ATCA we observed the selected sources in the NH3(1, 1) and (2, 2) transitions and in the H2O(616-523) maser line. Ammonia lines are a very good temperature probe that allow us to accurately determine the mass and the column, volume, and surface densities of the clumps. We also collected all data available to construct the spectral energy distribution of the individual clumps and to determine if star formation is already occurring through observations of its most common signposts, thus putting constraints on the evolutionary stage of the source. We fitted the spectral energy distribution between 1.2 mm and 70 μm with a modified black body to derive the dust temperature and independently determine the mass. Results: We find that the clumps are cold (T ~ 10-30 K), massive (M ~ 102-103 M⊙), and dense (n(H2) ≳ 105 cm-3) and that they have high column densities (N(H2) ~ 1023 cm-2). All clumps appear to be potentially able to form high-mass stars. The most massive clumps appear to be gravitationally unstable, if the only sources of support against collapse are turbulence and

  18. EPRI High-Sulfur Test Center: Wet FGD (flue gas desulfurization) sodium carbonate mass-transfer tests: Final report

    SciTech Connect

    Jarvis, J.B.; Burke, J.M.

    1988-10-01

    HSTC contains pilot- and mini-pilot-scale systems for investigating wet FGD technologies, as well as dry-injection and spray-drying pilot systems for investigating dry FGD technologies. A series of sodium carbonate (Na/sub 2/CO/sub 3/) mass-transfer tests is the first step in characterizing the SO/sub 2/ removal capabilities of wet FGD systems at HSTC. By using sodium as the SO/sub 2/ absorbent, an excess of liquid-phase alkalinity is provided to assure that gas-limited mass transfer alone will control SO/sub 2/ removal. Objectives of this project were to determine the maximum possible SO/sub 2/ removal capabilities of the HSTC wet FGD systems under different configurations; to provide data for modeling SO/sub 2/ absorption under gas-limited mass-transfer conditions. Sodium mass-transfer tests were conducted using slurry with a high concentration of liquid-phase alkalinity, established by adding sodium carbonate and maintained with a unique, in situ, dual-alkali operating system that continuously regenerated slurry alkalinity with slaked quicklime (Ca(OH)/sub 2/). This process allows testing of a slurry, simulating a lime or limestone scrubber, while maintaining an excess of liquid-phase alkalinity to assure gas-limited mass-transfer conditions. SO/sub 2/ removal efficiencies were measured of the mini-pilot and pilot systems for three absorber configurations---spray tower, tray tower, and packed tower. More than 300 tests were conducted over a wide range of operating conditions, using various types of spray nozzles characterized for spray distribution patterns. 5 refs., 74 figs., 23 tabs.

  19. Methodology for Mechanical Property Testing on Fuel Cladding Using an Expanded Plug Wedge Test

    SciTech Connect

    Wang, Jy-An John; Jiang, Hao

    2013-08-01

    To determine the tensile properties of irradiated fuel cladding in a hot cell, a simple test was developed at ORNL and is described fully in US Patent Application 20060070455, Expanded plug method for developing circumferential mechanical properties of tubular materials. This method is designed for testing fuel rod cladding ductility in a hot cell utilizing an expandable plug to stretch a small ring of irradiated cladding material. The specimen strain is determined using the measured diametrical expansion of the ring. This method removes many complexities associated with specimen preparation and testing. The advantages are the simplicity of measuring the test component assembly in the hot cell and the direct measurement of specimen strain. It was also found that cladding strength could be determined from the test results. The basic approach of this test method is to apply an axial compressive load to a cylindrical plug of polyurethane (or other materials) fitted inside a short ring of the test material to achieve radial expansion of the specimen. The diameter increase of the specimen is used to calculate the circumferential strain accrued during the test. The other two basic measurements are total applied load and amount of plug compression (extension). A simple procedure is used to convert the load circumferential strain data from the ring tests into material pseudo-stress-strain curves. However, several deficiencies exist in this expanded-plug loading ring test, which will impact accuracy of test results and introduce potential shear failure of the specimen due to inherited large axial compressive stress from the expansion plug test. First of all, the highly non-uniform stress and strain distribution resulted in the gage section of the clad. To ensure reliable testing and test repeatability, the potential for highly non-uniform stress distribution or displacement/strain deformation has to be eliminated at the gage section of the specimen. Second, significant

  20. Physical Properties of the Narrow-line Region of Low-mass Active Galaxies

    NASA Astrophysics Data System (ADS)

    Ludwig, Randi R.; Greene, Jenny E.; Barth, Aaron J.; Ho, Luis C.

    2012-09-01

    We present spectroscopic observations of 27 active galactic nuclei (AGNs) with some of the lowest black hole (BH) masses known. We use the high spectral resolution and small aperture of our Keck data, taken with the Echellette Spectrograph and Imager, to isolate the narrow-line regions (NLRs) of these low-mass BHs. We investigate their emission-line properties and compare them with those of AGNs with higher-mass BHs. While we are unable to determine absolute metallicities, some of our objects plausibly represent examples of the low-metallicity AGNs described by Groves et al., based on their [N II]/Hα ratios and their consistency with the Kewley & Ellison mass-metallicity relation. We find tentative evidence for steeper far-UV spectral slopes in lower-mass systems. Overall, NLR emission lines in these low-mass AGNs exhibit trends similar to those seen in AGNs with higher-mass BHs, such as increasing blueshifts and broadening with increasing ionization potential. Additionally, we see evidence of an intermediate-line region whose intensity correlates with L/L Edd, as seen in higher-mass AGNs. We highlight the interesting trend that, at least in these low-mass AGNs, the [O III] equivalent width (EW) is highest in symmetric NLR lines with no blue wing. This trend of increasing [O III] EW with line symmetry could be explained by a high covering factor of lower-ionization gas in the NLR. In general, low-mass AGNs preserve many well-known trends in the structure of the NLR, while exhibiting steeper ionizing continuum slopes and somewhat lower gas-phase metallicities.

  1. Low band gap frequencies and multiplexing properties in 1D and 2D mass spring structures

    NASA Astrophysics Data System (ADS)

    Aly, Arafa H.; Mehaney, Ahmed

    2016-11-01

    This study reports on the propagation of elastic waves in 1D and 2D mass spring structures. An analytical and computation model is presented for the 1D and 2D mass spring systems with different examples. An enhancement in the band gap values was obtained by modeling the structures to obtain low frequency band gaps at small dimensions. Additionally, the evolution of the band gap as a function of mass value is discussed. Special attention is devoted to the local resonance property in frequency ranges within the gaps in the band structure for the corresponding infinite periodic lattice in the 1D and 2D mass spring system. A linear defect formed of a row of specific masses produces an elastic waveguide that transmits at the narrow pass band frequency. The frequency of the waveguides can be selected by adjusting the mass and stiffness coefficients of the materials constituting the waveguide. Moreover, we pay more attention to analyze the wave multiplexer and DE-multiplexer in the 2D mass spring system. We show that two of these tunable waveguides with alternating materials can be employed to filter and separate specific frequencies from a broad band input signal. The presented simulation data is validated through comparison with the published research, and can be extended in the development of resonators and MEMS verification.

  2. Models for predicting the mass of lime fruits by some engineering properties.

    PubMed

    Miraei Ashtiani, Seyed-Hassan; Baradaran Motie, Jalal; Emadi, Bagher; Aghkhani, Mohammad-Hosein

    2014-11-01

    Grading fruits based on mass is important in packaging and reduces the waste, also increases the marketing value of agricultural produce. The aim of this study was mass modeling of two major cultivars of Iranian limes based on engineering attributes. Models were classified into three: 1-Single and multiple variable regressions of lime mass and dimensional characteristics. 2-Single and multiple variable regressions of lime mass and projected areas. 3-Single regression of lime mass based on its actual volume and calculated volume assumed as ellipsoid and prolate spheroid shapes. All properties considered in the current study were found to be statistically significant (ρ < 0.01). The results indicated that mass modeling of lime based on minor diameter and first projected area are the most appropriate models in the first and the second classifications, respectively. In third classification, the best model was obtained on the basis of the prolate spheroid volume. It was finally concluded that the suitable grading system of lime mass is based on prolate spheroid volume.

  3. Improving the repeatability of replicate analyses in the laser mass spectroscopy of powdered geological test samples

    SciTech Connect

    Oksenoid, K.G.; Ramendik, G.I.; Shuranova, N.G.

    1995-11-01

    During laser mass-spectroscopic analysis of powdered geological test samples, the conditions of ion formation vary because the optical units of the source focusing the laser beam onto the test sample become dusty. These variations result in the inadequate repeatability of replicate measurements at different exposures. It is shown that the change in the total number of ions generated changes the shape of the mass-calibration curve of a mass spectrometer, which is among the reasons for variations in the analytical signals of elements in the course of analysis. A technique proposed for the consideration of such ion discriminations is based on the concept of the predominant effect of a scattered magnetic field on their formation. The technique was tested in a set of twelve analyses of the International Geological Standard W-2 (diabase). With the use of this technique, the relative standard deviation was decreased several times to 13% averaged over 30 elements.

  4. Testing the Correlation between Spiral Arm Pitch Angle and Central Black Hole Mass

    NASA Astrophysics Data System (ADS)

    Shields, Douglas W.; Hughes, J. A.; Barrows, R. S.; Berrier, J.; Davis, B.; Kennefick, D.; Kennefick, J.; Ring, W.; Seigar, M.; Galaxy Evolution Survey, Arkansas

    2010-01-01

    In order to address the "cosmic downsizing problem," or the underpopulation of highly massive quasars in the current epoch, we are exploring a correlation between the pitch angle of a galaxy's spiral arms and the mass of its central supermassive black hole (SMBH). The goal is to generate a census of SMBH masses using only photographic images. This study presents preliminary results testing the relationship between mass and pitch angle by comparing the masses of a sample of active spiral galaxies as calculated by the pitch angle method with those calculated by the mass scaling relationship. Additionally, we present the null correlation between the pitch angle of spiral galaxies and redshift. The data set includes 225 galaxies from the GOODS North and South fields with redshifts out to z 1. There does not appear to be any dependence of pitch angle on redshift. Consequently, if the relationship between pitch angle and SMBH mass has not evolved since z 1, then the mean mass of SMBH has also remained constant. If, on the other hand, the relationship has evolved, then the mean mass has evolved inversely with the relationship. This conclusion is subject to further studies on possible selection effects. This research was funded by NASA/EPSCOR.

  5. Furniture wood wastes: Experimental property characterisation and burning tests

    SciTech Connect

    Tatano, Fabio Barbadoro, Luca; Mangani, Giovanna; Pretelli, Silvia; Tombari, Lucia; Mangani, Filippo

    2009-10-15

    Referring to the industrial wood waste category (as dominant in the provincial district of Pesaro-Urbino, Marche Region, Italy), this paper deals with the experimental characterisation and the carrying out of non-controlled burning tests (at lab- and pilot-scale) for selected 'raw' and primarily 'engineered' ('composite') wood wastes. The property characterisation has primarily revealed the following aspects: potential influence on moisture content of local weather conditions at outdoor wood waste storage sites; generally, higher ash contents in 'engineered' wood wastes as compared with 'raw' wood wastes; and relatively high energy content values of 'engineered' wood wastes (ranging on the whole from 3675 to 5105 kcal kg{sup -1} for HHV, and from 3304 to 4634 kcal kg{sup -1} for LHV). The smoke qualitative analysis of non-controlled lab-scale burning tests has primarily revealed: the presence of specific organic compounds indicative of incomplete wood combustion; the presence exclusively in 'engineered' wood burning tests of pyrroles and amines, as well as the additional presence (as compared with 'raw' wood burning) of further phenolic and containing nitrogen compounds; and the potential environmental impact of incomplete industrial wood burning on the photochemical smog phenomenon. Finally, non-controlled pilot-scale burning tests have primarily given the following findings: emission presence of carbon monoxide indicative of incomplete wood combustion; higher nitrogen oxide emission values detected in 'engineered' wood burning tests as compared with 'raw' wood burning test; and considerable generation of the respirable PM{sub 1} fraction during incomplete industrial wood burning.

  6. Quasi-Uniform High Speed Foam Crush Testing Using a Guided Drop Mass Impact

    NASA Technical Reports Server (NTRS)

    Jones, Lisa E. (Technical Monitor); Kellas, Sotiris

    2004-01-01

    A relatively simple method for measuring the dynamic crush response of foam materials at various loading rates is described. The method utilizes a drop mass impact configuration with mass and impact velocity selected such that the crush speed remains approximately uniform during the entire sample crushing event. Instrumentation, data acquisition, and data processing techniques are presented, and limitations of the test method are discussed. The objective of the test method is to produce input data for dynamic finite element modeling involving crash and energy absorption characteristics of foam materials.

  7. BEYOND THE MAIN SEQUENCE: TESTING THE ACCURACY OF STELLAR MASSES PREDICTED BY THE PARSEC EVOLUTIONARY TRACKS

    SciTech Connect

    Ghezzi, Luan; Johnson, John Asher

    2015-10-20

    Characterizing the physical properties of exoplanets and understanding their formation and orbital evolution requires precise and accurate knowledge of their host stars. Accurately measuring stellar masses is particularly important because they likely influence planet occurrence and the architectures of planetary systems. Single main-sequence stars typically have masses estimated from evolutionary tracks, which generally provide accurate results due to their extensive empirical calibration. However, the validity of this method for subgiants and giants has been called into question by recent studies, with suggestions that the masses of these evolved stars could have been overestimated. We investigate these concerns using a sample of 59 benchmark evolved stars with model-independent masses (from binary systems or asteroseismology) obtained from the literature. We find very good agreement between these benchmark masses and the ones estimated using evolutionary tracks. The average fractional difference in the mass interval ∼0.7–4.5 M{sub ⊙} is consistent with zero (−1.30 ± 2.42%), with no significant trends in the residuals relative to the input parameters. A good agreement between model-dependent and -independent radii (−4.81 ± 1.32%) and surface gravities (0.71 ± 0.51%) is also found. The consistency between independently determined ages for members of binary systems adds further support for the accuracy of the method employed to derive the stellar masses. Taken together, our results indicate that determination of masses of evolved stars using grids of evolutionary tracks is not significantly affected by systematic errors, and is thus valid for estimating the masses of isolated stars beyond the main sequence.

  8. Mass Transfer Testing of a 12.5-cm Rotor Centrifugal Contactor

    SciTech Connect

    D. H. Meikrantz; T. G. Garn; J. D. Law; N. R. Mann; T. A. Todd

    2008-09-01

    TRUEX mass transfer tests were performed using a single stage commercially available 12.5 cm centrifugal contactor and stable cerium (Ce) and europium (Eu). Test conditions included throughputs ranging from 2.5 to 15 Lpm and rotor speeds of 1750 and 2250 rpm. Ce and Eu extraction forward distribution coefficients ranged from 13 to 19. The first and second stage strip back distributions were 0.5 to 1.4 and .002 to .004, respectively, throughout the dynamic test conditions studied. Visual carryover of aqueous entrainment in all organic phase samples was estimated at < 0.1 % and organic carryover into all aqueous phase samples was about ten times less. Mass transfer efficiencies of = 98 % for both Ce and Eu in the extraction section were obtained over the entire range of test conditions. The first strip stage mass transfer efficiencies ranged from 75 to 93% trending higher with increasing throughput. Second stage mass transfer was greater than 99% in all cases. Increasing the rotor speed from 1750 to 2250 rpm had no significant effect on efficiency for all throughputs tested.

  9. Mechanical properties and supporting effect of CRLD bolts under static pull test conditions

    NASA Astrophysics Data System (ADS)

    Sun, Xiao-ming; Zhang, Yong; Wang, Dong; Yang, Jun; Xu, Hui-chen; He, Man-chao

    2017-01-01

    A device for supporting soft rock masses combined with a constant resistance structure characterized by constant resistance and large deformation at the end of a steel bar, known as the constant resistance and large deformation (CRLD) bolt, has recently been developed to counteract soft rock swelling that often occurs during deep mining. In order to further study the mechanical properties of the CRLD bolt, we investigated its mechanical properties by comparison with the conventional strength bolt (rebar) using static pull tests on many aspects, including supporting capacity, elongation, radial deformation, and energy absorption. The tests verified that the mechanical defects of the rebar, which include the decrease of bolt diameter, reduction of supporting capacity, and emergence and evolution of fracture until failure during the whole pull process, were caused by the Poisson's ratio effect. Due to the special structure set on the CRLD bolt, the bolt presents a seemingly unusual phenomenon of the negative Poisson's ratio effect, i.e., the diameter of the constant resistance structure increases while under-pulling. It is the very effect that ensures the extraordinary mechanical properties, including high resistance, large elongation, and strong energy absorption. According to the comparison and analysis of numerical simulation and field test, we can conclude that the CRLD bolt works better than the rebar bolt.

  10. Testing Fundamental Properties of Ionic Liquids for Colloid Microthruster Applications

    NASA Technical Reports Server (NTRS)

    Anderson, John R.; Plett, Gary; Anderson, Mark; Ziemer, John

    2006-01-01

    NASA's New Millennium Program is scheduled to test a Disturbance Reduction System (DRS) on Space Technology 7 (ST7) as part of the European Space Agency's (ESA's) LISA Pathfinder Mission in late 2009. Colloid Micronewton Thrusters (CMNTs) will be used to counteract forces, mainly solar photon pressure, that could disturb gravitational reference sensors as part of the DRS. The micronewton thrusters use an ionic liquid, a room temperature molten salt, as propellant. The ionic liquid has a number of unusual properties that have a direct impact on thruster design. One of the most important issues is bubble formation before and during operation, especially during rapid pressure transitions from atmospheric to vacuum conditions. Bubbles have been observed in the feed system causing variations in propellant flow rate that can adversely affect thruster control. Bubbles in the feed system can also increase the likelihood that propellant will spray onto surfaces that can eventually lead to shorting high voltage electrodes. Two approaches, reducing the probability of bubble formation and removing bubbles with a new bubble eliminator device in the flow system, were investigated at Busek Co., Inc. and the Jet Propulsion Laboratory (JPL) to determine the effectiveness of both approaches. Results show that bubble formation is mainly caused by operation at low pressure and volatile contaminants in the propellant coming out of solution. A specification for the maximum tolerable level of contamination has been developed, and procedures for providing system cleanliness have been tested and implemented. The bubble eliminator device has also been tested successfully and has been implemented in recent thruster designs at Busek. This paper focuses on the propellant testing work at JPL, including testing of a breadboard level bubble eliminator device.

  11. Testing Fundamental Properties of Ionic Liquids for Colloid Microthruster Applications

    NASA Technical Reports Server (NTRS)

    Anderson, John R.; Plett, Gary; Anderson, Mark; Ziemer, John

    2006-01-01

    NASA's New Millennium Program is scheduled to test a Disturbance Reduction System (DRS) on Space Technology 7 (ST7) as part of the European Space Agency's (ESA's) LISA Pathfinder Mission in late 2009. Colloid Micronewton Thrusters (CMNTs) will be used to counteract forces, mainly solar photon pressure, that could disturb gravitational reference sensors as part of the DRS. The micronewton thrusters use an ionic liquid, a room temperature molten salt, as propellant. The ionic liquid has a number of unusual properties that have a direct impact on thruster design. One of the most important issues is bubble formation before and during operation, especially during rapid pressure transitions from atmospheric to vacuum conditions. Bubbles have been observed in the feed system causing variations in propellant flow rate that can adversely affect thruster control. Bubbles in the feed system can also increase the likelihood that propellant will spray onto surfaces that can eventually lead to shorting high voltage electrodes. Two approaches, reducing the probability of bubble formation and removing bubbles with a new bubble eliminator device in the flow system, were investigated at Busek Co., Inc. and the Jet Propulsion Laboratory (JPL) to determine the effectiveness of both approaches. Results show that bubble formation is mainly caused by operation at low pressure and volatile contaminants in the propellant coming out of solution. A specification for the maximum tolerable level of contamination has been developed, and procedures for providing system cleanliness have been tested and implemented. The bubble eliminator device has also been tested successfully and has been implemented in recent thruster designs at Busek. This paper focuses on the propellant testing work at JPL, including testing of a breadboard level bubble eliminator device.

  12. Tester Board for testing mass-produced SMB modules for CMS Preshower

    NASA Astrophysics Data System (ADS)

    Velikzhanin, Y. S.; Chou, C. H.; Hsiung, Y. B.; Lee, Y. J.; Shiu, J. G.; Sun, C. D.; Wang, Y. Z.

    2007-09-01

    We have developed a Tester Board to test the electrical characteristics of the System Motherboard (SMB) for the CMS Preshower detector at CERN. The board is designed to test input resistances, output resistances, connections, interconnections and possible short- circuits of a module having up to 640 connector pins. The Tester Board is general-purpose in nature: it could be used to test any electronic module or cable by using dedicated cable sets. The module can detect a variety of problems not detected by either functional tests or the "flying probes" technique. The design, algorithms and results of using the Tester Board during mass production of CMS Preshower SMBs are presented.

  13. Testing Horava-Lifshitz gravity using thin accretion disk properties

    SciTech Connect

    Harko, Tiberiu; Kovacs, Zoltan; Lobo, Francisco S. N.

    2009-08-15

    Recently, a renormalizable gravity theory with higher spatial derivatives in four dimensions was proposed by Horava. The theory reduces to Einstein gravity with a nonvanishing cosmological constant in IR, but it has improved UV behaviors. The spherically symmetric black hole solutions for an arbitrary cosmological constant, which represent the generalization of the standard Schwarzschild-(anti) de Sitter solution, have also been obtained for the Horava-Lifshitz theory. The exact asymptotically flat Schwarzschild-type solution of the gravitational field equations in Horava gravity contains a quadratic increasing term, as well as the square root of a fourth order polynomial in the radial coordinate, and it depends on one arbitrary integration constant. The IR-modified Horava gravity seems to be consistent with the current observational data, but in order to test its viability more observational constraints are necessary. In the present paper we consider the possibility of observationally testing Horava gravity by using the accretion disk properties around black holes. The energy flux, the temperature distribution, the emission spectrum, as well as the energy conversion efficiency are obtained, and compared to the standard general relativistic case. Particular signatures can appear in the electromagnetic spectrum, thus leading to the possibility of directly testing Horava gravity models by using astrophysical observations of the emission spectra from accretion disks.

  14. Synchrotron based mass spectrometry to investigate the molecular properties of mineral-organic associations

    SciTech Connect

    Liu, Suet Yi; Kleber, Markus; Takahashi, Lynelle K.; Nico, Peter; Keiluweit, Marco; Ahmed, Musahid

    2013-04-01

    Soil organic matter (OM) is important because its decay drives life processes in the biosphere. Analysis of organic compounds in geological systems is difficult because of their intimate association with mineral surfaces. To date there is no procedure capable of quantitatively separating organic from mineral phases without creating artifacts or mass loss. Therefore, analytical techniques that can (a) generate information about both organic and mineral phases simultaneously and (b) allow the examination of predetermined high-interest regions of the sample as opposed to conventional bulk analytical techniques are valuable. Laser Desorption Synchrotron Postionization (synchrotron-LDPI) mass spectrometry is introduced as a novel analytical tool to characterize the molecular properties of organic compounds in mineral-organic samples from terrestrial systems, and it is demonstrated that when combined with Secondary Ion Mass Spectrometry (SIMS), can provide complementary information on mineral composition. Mass spectrometry along a decomposition gradient in density fractions, verifies the consistency of our results with bulk analytical techniques. We further demonstrate that by changing laser and photoionization energies, variations in molecular stability of organic compounds associated with mineral surfaces can be determined. The combination of synchrotron-LDPI and SIMS shows that the energetic conditions involved in desorption and ionization of organic matter may be a greater determinant of mass spectral signatures than the inherent molecular structure of the organic compounds investigated. The latter has implications for molecular models of natural organic matter that are based on mass spectrometric information.

  15. Physical Properties Of The NLR In Low-mass Active Galaxies

    NASA Astrophysics Data System (ADS)

    Ludwig, Randi R.; Greene, J. E.; Barth, A. J.; Ho, L. C.

    2012-01-01

    We present high-resolution spectroscopic observations of 27 active galactic nuclei (AGN) with black hole masses M_BH < 2 × 10^6 M⊙. We investigate their narrow emission line properties and compare them with those of AGN with higher mass black holes. While we are unable to determine absolute metallicities, these low-luminosity objects plausibly represent AGN with sub-solar metallicities, based on their [N II]/Hα ratios and their consistency with the Kewley et al. (2008) mass-metallicity relation. We find that these low-mass AGN have UV continuum slopes similar to those of more massive AGN based on their He II/Hβ ratio, similar blueshifts and broadening in their narrow lines with respect to ionization potential, and we see evidence of an intermediate line region whose intensity correlates with L/L_Edd in these objects. In contrast to higher-mass AGN, we find that the low-mass AGN have selectively high narrow line EWs when [O III] shows no blue wing, which could be explained by a high covering factor of lower ionization gas in the narrow-line region of objects with symmetric emission lines.

  16. THE MASS DISTRIBUTION AND ASSEMBLY OF THE MILKY WAY FROM THE PROPERTIES OF THE MAGELLANIC CLOUDS

    SciTech Connect

    Busha, Michael T.; Marshall, Philip J.; Wechsler, Risa H.; Klypin, Anatoly; Primack, Joel E-mail: pjm@slac.stanford.edu E-mail: aklypin@nmsu.edu

    2011-12-10

    We present a new measurement of the mass of the Milky Way (MW) based on observed properties of its largest satellite galaxies, the Magellanic Clouds (MCs), and an assumed prior of a {Lambda}CDM universe. The large, high-resolution Bolshoi cosmological simulation of this universe provides a means to statistically sample the dynamical properties of bright satellite galaxies in a large population of dark matter halos. The observed properties of the MCs, including their circular velocity, distance from the center of the MW, and velocity within the MW halo, are used to evaluate the likelihood that a given halo would have each or all of these properties; the posterior probability distribution function (PDF) for any property of the MW system can thus be constructed. This method provides a constraint on the MW virial mass, 1.2{sup +0.7}{sub -0.4} (stat.){sup +0.3}{sub -0.3} (sys.) Multiplication-Sign 10{sup 12} M{sub Sun} (68% confidence), which is consistent with recent determinations that involve very different assumptions. In addition, we calculate the posterior PDF for the density profile of the MW and its satellite accretion history. Although typical satellites of 10{sup 12} M{sub Sun} halos are accreted over a wide range of epochs over the last 10 Gyr, we find a {approx}72% probability that the MCs were accreted within the last Gyr, and a 50% probability that they were accreted together.

  17. The Mass Distribution and Assembly of the Milky Way from the Properties of the Magellanic Clouds

    SciTech Connect

    Busha, Michael T.; Marshall, Philip J.; Wechsler, Risa H.; Klypin, Anatoly; Primack, Joel; /UC, Santa Cruz, Phys. Dept.

    2012-02-29

    We present a new measurement of the mass of the Milky Way (MW) based on observed properties of its largest satellite galaxies, the Magellanic Clouds (MCs), and an assumed prior of a {Lambda}CDM universe. The large, high-resolution Bolshoi cosmological simulation of this universe provides a means to statistically sample the dynamical properties of bright satellite galaxies in a large population of dark matter halos. The observed properties of the MCs, including their circular velocity, distance from the center of the MW, and velocity within the MW halo, are used to evaluate the likelihood that a given halo would have each or all of these properties; the posterior probability distribution function (PDF) for any property of the MW system can thus be constructed. This method provides a constraint on the MW virial mass, 1.2{sup +0.7} - {sub 0.4}(stat.){sup +0.3} - {sub 0.3}(sys.) x 10{sup 12} M {circle_dot} (68% confidence), which is consistent with recent determinations that involve very different assumptions. In addition, we calculate the posterior PDF for the density profile of the MW and its satellite accretion history. Although typical satellites of 10{sup 12} M {circle_dot} halos are accreted over a wide range of epochs over the last 10 Gyr, we find a {approx}72% probability that the MCs were accreted within the last Gyr, and a 50% probability that they were accreted together.

  18. Journal: A Review of Some Tracer-Test Design Equations for Tracer-Mass Estimation and Sample Collection Frequency

    EPA Science Inventory

    Determination of necessary tracer mass, initial sample-collection time, and subsequent sample-collection frequency are the three most difficult aspects to estimate for a proposed tracer test prior to conducting the tracer test. To facilitate tracer-mass estimation, 33 mass-estima...

  19. Journal: A Review of Some Tracer-Test Design Equations for Tracer-Mass Estimation and Sample Collection Frequency

    EPA Science Inventory

    Determination of necessary tracer mass, initial sample-collection time, and subsequent sample-collection frequency are the three most difficult aspects to estimate for a proposed tracer test prior to conducting the tracer test. To facilitate tracer-mass estimation, 33 mass-estima...

  20. Microstructure and mechanical properties of Ti-40 mass % Nb alloy after megaplastic deformation effect

    NASA Astrophysics Data System (ADS)

    Sharkeev, Yurii P.; Eroshenko, Anna Yu.; Glukhov, Ivan A.; Sun, Zeming; Zhu, Qifang; Danilov, Vladimir I.; Tolmachev, Alexei I.

    2015-10-01

    The microstructure and mechanical properties of Ti alloy contained 40 mass % Nb at megaplastic deformation effect is described. It was proved that the deformation effect including the multiple abc-pressing and multi-pass rolling and further pre-recrystallizing annealing enhances the formation of ultra-fine grained structures with mean element size of 0.3 μm or less, involving stable (β + α)-phase composition and metastable nanosized ω-phase in the alloy. This, in its turn, significantly improves the mechanical properties and simultaneously preserves low elastic modulus level.

  1. Developing mass spectrometric techniques for boundary layer measurement in hypersonic high enthalpy test facilities

    NASA Technical Reports Server (NTRS)

    Wood, G. M., Jr.; Lewis, B. W.; Nowak, R. J.; Eide, D. G.; Paulin, P. A.; Upchurch, B. T.

    1983-01-01

    Thermodynamic flow properties of gases in the boundary layer or the flowfield have been mainly deduced from pressures and temperatures measured on a model. However, further progress with respect to an understanding of these properties requires a more complete characterization of the layer including determination of the gas composition and chemistry. Most attempts to measure boundary layer chemistry involve the employment of a mass spectrometer and an associated gas sampling system. The three major limiting factors which must be addressed for species measurement in aerothermodynamic investigations on models at reentry stream velocities, are gas sampling effects, instrument limitations, and problems with data acquisition. The present investigation is concerned with a concentrated effort to quantitatively identify and correct for instrument and sampling system effects, and to develop a miniaturized high performance mass spectrometer for on-model real-time analysis of the boundary layer and its associated atmosphere.

  2. Test of IMME in fp shell via direct mass measurements of nuclides

    NASA Astrophysics Data System (ADS)

    Zhang, Y. H.; Xu, H. S.; Litvinov, Yu A.; Tu, X. L.; Yan, X. L.; Typel, S.; Blaum, K.; Wang, M.; Zhou, X. H.; Sun, Y.; Brown, B. A.; Yuan, Y. J.; Xia, J. W.; Yang, J. C.; Audi, G.; Chen, X. C.; Jia, G. B.; Hu, Z. G.; Ma, X. W.; Mao, R. S.; Mei, B.; Shuai, P.; Sun, Z. Y.; Wang, S. T.; Xiao, G. Q.; Xu, X.; Yamaguchi, T.; Yamaguchi, Y.; Zang, Y. D.; Zhao, H. W.; Zhao, T. C.; Zhang, W.; Zhan, W. L.

    2013-03-01

    Isochronous mass spectrometry has been applied to neutron-deficient 58Ni projectile fragments at the HIRFL-CSR facility in Lanzhou, China. Masses of four shortlived Tz = -3/2 nuclides 41Ti, 45Cr, 49Fe, and 53Ni have been measured with a precision of 20 — 40 keV. The new mass data enabled for the first time to test the isobaric multiplet mass equation (IMME) in fp-shell nuclei. We observed that the IMME is inconsistent with the generally accepted quadratic form for the A = 53, T = 3/2 quartet. We performed full space shell model calculations and compared them with the new experimental results. The main results were published in Y.H. Zhang et al., Physical Review Letters 109 (2012). Here we give details on the experiment and data analysis as well as summarize the main findings.

  3. Pulsating low-mass white dwarfs in the frame of new evolutionary sequences. I. Adiabatic properties

    NASA Astrophysics Data System (ADS)

    Córsico, A. H.; Althaus, L. G.

    2014-09-01

    Context. Many low-mass white dwarfs with masses M∗/M⊙ ≲ 0.45, including the so-called extremely low-mass white dwarfs (M∗/M⊙ ≲ 0.20 - 0.25), have recently been discovered in the field of our Galaxy through dedicated photometric surveys. The subsequent discovery of pulsations in some of them has opened the unprecedented opportunity of probing the internal structure of these ancient stars. Aims: We present a detailed adiabatic pulsational study of these stars based on full evolutionary sequences derived from binary star evolution computations. The main aim of this study is to provide a detailed theoretical basis of reference for interpreting present and future observations of variable low-mass white dwarfs. Methods: Our pulsational analysis is based on a new set of He-core white-dwarf models with masses ranging from 0.1554 to 0.4352 M⊙ derived by computing the non-conservative evolution of a binary system consisting of an initially 1 M⊙ ZAMS star and a 1.4 M⊙ neutron star. We computed adiabatic radial (ℓ = 0) and non-radial (ℓ = 1,2) p and g modes to assess the dependence of the pulsational properties of these objects on stellar parameters such as the stellar mass and the effective temperature, as well as the effects of element diffusion. Results: We found that for white dwarf models with masses below ~ 0.18 M⊙, g modes mainly probe the core regions and p modes the envelope, therefore pulsations offer the opportunity of constraining both the core and envelope chemical structure of these stars via asteroseismology. For models with M∗ ≳ 0.18 M⊙, on the other hand, g modes are very sensitive to the He/H compositional gradient and therefore can be used as a diagnostic tool for constraining the H envelope thickness. Because both types of objects have not only very distinct evolutionary histories (according to whether the progenitor stars have experienced CNO-flashes or not), but also have strongly different pulsation properties, we propose to

  4. Testing the white dwarf mass-radius relationship with eclipsing binaries

    NASA Astrophysics Data System (ADS)

    Parsons, S. G.; Gänsicke, B. T.; Marsh, T. R.; Ashley, R. P.; Bours, M. C. P.; Breedt, E.; Burleigh, M. R.; Copperwheat, C. M.; Dhillon, V. S.; Green, M.; Hardy, L. K.; Hermes, J. J.; Irawati, P.; Kerry, P.; Littlefair, S. P.; McAllister, M. J.; Rattanasoon, S.; Rebassa-Mansergas, A.; Sahman, D. I.; Schreiber, M. R.

    2017-10-01

    We present high-precision, model-independent, mass and radius measurements for 16 white dwarfs in detached eclipsing binaries and combine these with previously published data to test the theoretical white dwarf mass-radius relationship. We reach a mean precision of 2.4 per cent in mass and 2.7 per cent in radius, with our best measurements reaching a precision of 0.3 per cent in mass and 0.5 per cent in radius. We find excellent agreement between the measured and predicted radii across a wide range of masses and temperatures. We also find the radii of all white dwarfs with masses less than 0.48 M⊙ to be fully consistent with helium core models, but they are on average 9 per cent larger than those of carbon-oxygen core models. In contrast, white dwarfs with masses larger than 0.52 M⊙ all have radii consistent with carbon-oxygen core models. Moreover, we find that all but one of the white dwarfs in our sample have radii consistent with possessing thick surface hydrogen envelopes (10-5 ≥ MH/MWD ≥ 10-4), implying that the surface hydrogen layers of these white dwarfs are not obviously affected by common envelope evolution.

  5. Testing the Correlation between Spiral Arm Pitch Angle and Central Black Hole Mass

    NASA Astrophysics Data System (ADS)

    Shields, Douglas W.; Hughes, J. Adam; Barrows, Scott R.; Davis, Ben; Kennefick, Daniel; Kennefick, Julia; Ring, William; Seigar, Marc

    2010-11-01

    In order to address the ``cosmic downsizing problem,'' or the underpopulation of highly massive quasars in the current epoch, the Arkansas Galaxy Evolution Survey is exploring a correlation, the M-P relation, between the pitch angle of a galaxy's spiral arms and the mass of its central supermassive black hole (SMBH). The goal is to add to the census of SMBH masses using only images, without relying on spectra. We present the null correlation between the pitch angle of spiral arms and redshift. The data set includes 225 galaxies from the GOODS North and South fields with redshifts out to z~1.2. There does not appear to be any dependence of pitch angle on redshift. Consequently, if the relationship between pitch angle and SMBH mass has not evolved since z~1.2, then the mean mass of SMBH has also remained constant. If, on the other hand, the relationship has evolved, then the mean mass has evolved inversely with the relationship. This conclusion is subject to further studies on possible selection effects. Additionally, we present preliminary results testing the M-P relation by comparing the masses of a sample of active spiral galaxies as calculated by the pitch angle method with those calculated by the mass scaling relationship.

  6. Hybrid Residual Flexibility/Mass-Additive Method for Structural Dynamic Testing

    NASA Technical Reports Server (NTRS)

    Tinker, M. L.

    2003-01-01

    A large fixture was designed and constructed for modal vibration testing of International Space Station elements. This fixed-base test fixture, which weighs thousands of pounds and is anchored to a massive concrete floor, initially utilized spherical bearings and pendulum mechanisms to simulate Shuttle orbiter boundary constraints for launch of the hardware. Many difficulties were encountered during a checkout test of the common module prototype structure, mainly due to undesirable friction and excessive clearances in the test-article-to-fixture interface bearings. Measured mode shapes and frequencies were not representative of orbiter-constrained modes due to the friction and clearance effects in the bearings. As a result, a major redesign effort for the interface mechanisms was undertaken. The total cost of the fixture design, construction and checkout, and redesign was over $2 million. Because of the problems experienced with fixed-base testing, alternative free-suspension methods were studied, including the residual flexibility and mass-additive approaches. Free-suspension structural dynamics test methods utilize soft elastic bungee cords and overhead frame suspension systems that are less complex and much less expensive than fixed-base systems. The cost of free-suspension fixturing is on the order of tens of thousands of dollars as opposed to millions, for large fixed-base fixturing. In addition, free-suspension test configurations are portable, allowing modal tests to be done at sites without modal test facilities. For example, a mass-additive modal test of the ASTRO-1 Shuttle payload was done at the Kennedy Space Center launch site. In this Technical Memorandum, the mass-additive and residual flexibility test methods are described in detail. A discussion of a hybrid approach that combines the best characteristics of each method follows and is the focus of the study.

  7. Dependence of Dynamic Modeling Accuracy on Sensor Measurements, Mass Properties, and Aircraft Geometry

    NASA Technical Reports Server (NTRS)

    Grauer, Jared A.; Morelli, Eugene A.

    2013-01-01

    The NASA Generic Transport Model (GTM) nonlinear simulation was used to investigate the effects of errors in sensor measurements, mass properties, and aircraft geometry on the accuracy of identified parameters in mathematical models describing the flight dynamics and determined from flight data. Measurements from a typical flight condition and system identification maneuver were systematically and progressively deteriorated by introducing noise, resolution errors, and bias errors. The data were then used to estimate nondimensional stability and control derivatives within a Monte Carlo simulation. Based on these results, recommendations are provided for maximum allowable errors in sensor measurements, mass properties, and aircraft geometry to achieve desired levels of dynamic modeling accuracy. Results using additional flight conditions and parameter estimation methods, as well as a nonlinear flight simulation of the General Dynamics F-16 aircraft, were compared with these recommendations

  8. Direct measurements of the fundamental properties of low-mass stars and brown dwarfs

    NASA Astrophysics Data System (ADS)

    Dupuy, Trent J.

    2010-10-01

    Detailed theoretical models of stars, developed and observationally tested over the last century, now underlie most of modern astronomy. In contrast, models of lower temperature objects, brown dwarfs and gas giant planets, have only recently been developed and remained largely unconstrained by observations. Despite this lack of empirical validation, these models have become entrenched in many active areas of astronomical research, and thus rigorously testing them is imperative. Dynamical masses from visual binaries are central to this effort, but such measurements have been previously been impeded by observational limitations (ultracool binaries are faint, and their orbital separations are very small). This dissertation presents results from our program to test models using precise dynamical masses (as good as 2%) for ultracool binaries, based on infrared parallaxes, near-infrared spectroscopy, and Keck laser guide star adaptive optics astrometry for a sample of over 30 objects. In just the last 2 years, we have more than tripled the number of ultracool binaries with dynamical masses, extending these measurements to much lower temperatures in previously unexplored areas of parameter space. Our main results are summarized as follows: (1) For most field binaries, based on direct measurements of their luminosities and masses, we find that the temperatures predicted by evolutionary models are discrepant with those derived from fitting the observed spectra with model atmospheres, indicating systematic errors of [approximate]200 K in temperature (or 15%-20% in radius). We have also devised alternative model tests for these systems using their space motion and chromospheric activity to constrain their ages. (2) For the only field binary with an independent age determination from the solar-type primary in its hierarchical triple system (from age-activity-rotation relations), we find that evolutionary models systematically underpredict luminosities by a factor of

  9. Sweat testing for cocaine, codeine and metabolites by gas chromatography-mass spectrometry.

    PubMed

    Huestis, M A; Oyler, J M; Cone, E J; Wstadik, A T; Schoendorfer, D; Joseph, R E

    1999-10-15

    Sweat testing for drugs of abuse provides a convenient and considerably less invasive method for monitoring drug exposure than blood or urine. Numerous devices have been developed for collection of sweat specimens. The most common device in current use is the PharmChek Sweat Patch, which usually is worn by an individual for five to ten days. This device has been utilized in several field trials comparing sweat test results to conventional urinalysis and the results have been favorable. Two new Fast Patch devices have been developed and tested that allow rapid collection of sweat specimens. The Hand-held Fast Patch was applied to the palm of the hand and the Torso Fast Patch was applied to the abdomen or the sides of the trunk (flanks) of volunteer subjects participating in a research study. Both patches employed heat-induced sweat stimulation and a larger cellulose pad for increased drug collection. Sweat specimens were collected for 30 min at various times following administration of cocaine or codeine in controlled dosing studies. After patch removal, the cellulose pad was extracted with sodium acetate buffer, followed by solid-phase extraction. Extracts were derivatized and analyzed by gas chromatography mass spectrometry (GC-MS) simultaneously for cocaine, codeine and metabolites. Cocaine and codeine were the primary analytes detected in sweat. Peak cocaine and codeine concentrations ranged from 33 to 3579 ng/patch and 11 to 1123 ng/patch, respectively, across all doses for the Hand-held Patch compared to 22-1463 ng/patch and 12-360 ng/patch, respectively, for the Torso Fast Patch. Peak concentrations generally occurred 4.5-24 h after dosing. Both drugs could be detected for at least 48 h after dosing. Considerably smaller concentrations of metabolites of cocaine and codeine were also present in some patches. Generally, concentrations of cocaine and codeine were higher in sweat specimens collected with the Hand-held Fast Patch than for the Torso Fast Patch

  10. Testing the Environmental Dependence of the Stellar Initial Mass Function - the Case of L1641

    NASA Astrophysics Data System (ADS)

    Hsu, Wen-hsin; Hartmann, L.; Allen, L.; Hernandez, J.; Megeath, T.

    2012-01-01

    To test the proposition that the stellar initial mass function (IMF) depends on the environmental density, we conducted an optical spectroscopic and photometric survey of the young stellar population in L1641, a low-density, star-forming region of the Orion A cloud south of the dense Orion Nebula Cluster (ONC). We used low-resolution optical spectra and optical photometry, as well as the Spitzer IRAC photometry (Megeath et al. 2011) to identify members and obtain spectral types. As of now, we have confirmed and spectral-typed 648 members and project a total number of 780 members with moderate extinction. Our study suggests a comparison between L1641 and the ONC can yield a statistically-significant test of the dependence of the upper mass portion of the stellar initial mass function upon environment. Our preliminary results indicate that L1641 may well be deficient in O and early B stars.

  11. Numerical Tests and Properties of Waves in Radiating Fluids

    SciTech Connect

    Johnson, B M; Klein, R I

    2009-09-03

    We discuss the properties of an analytical solution for waves in radiating fluids, with a view towards its implementation as a quantitative test of radiation hydrodynamics codes. A homogeneous radiating fluid in local thermodynamic equilibrium is periodically driven at the boundary of a one-dimensional domain, and the solution describes the propagation of the waves thus excited. Two modes are excited for a given driving frequency, generally referred to as a radiative acoustic wave and a radiative diffusion wave. While the analytical solution is well known, several features are highlighted here that require care during its numerical implementation. We compare the solution in a wide range of parameter space to a numerical integration with a Lagrangian radiation hydrodynamics code. Our most significant observation is that flux-limited diffusion does not preserve causality for waves on a homogeneous background.

  12. Properties of high-energy isoscalar monopole excitations in medium-heavy mass spherical nuclei

    SciTech Connect

    Gorelik, M. L. Shlomo, Sh. Tulupov, B. A. Urin, M. H.

    2015-07-15

    The recently developed particle-hole dispersive optical model is applied to describe properties of high-energy isoscalar monopole excitations in medium-heavy mass spherical nuclei. In particular, the double transition density averaged over the energy of the isoscalar monopole excitations is considered for {sup 208}Pb in a wide energy interval, which includes the isoscalar giant monopole resonance and its overtone. The energy-averaged strength functions of these resonances are also analyzed.

  13. Magnetic properties of low mass stars: new discoveries and future prospects

    NASA Astrophysics Data System (ADS)

    Shulyak, Denis

    2017-05-01

    Measuring properties of surface magnetic fields is the path towards our understanding of stellar dynamos and environment of stars with convective envelopes. In this talk I will summarize what have we learned about magnetism in low-mass stars over last decades from numerous spectroscopic and polarimetric studies, and discuss on newest discoveries of strongest magnetic fields ever found in these objects since early eightees.

  14. Properties of the outer crust of neutron stars from Hartree-Fock-Bogoliubov mass models

    SciTech Connect

    Pearson, J. M.; Goriely, S.; Chamel, N.

    2011-06-15

    We have calculated the zero-temperature properties of the outer crust of neutron stars for four nuclear-mass models based on the Hartree-Fock-Bogoliubov method: the three most recent Skyrme-force models (HFB-19, HFB-20, and HFB-21) and the Gogny-force model D1M. While the equation of state is substantially the same for the four models, the nuclidic composition varies considerably from one model to another. We solve the Tolman-Oppenheimer-Volkoff equations by integrating inward from the surface and thereby determine the abundance of each nuclide in the outer crust of a typical neutron star of mass 1.5M{sub {center_dot}} and radius 13 km. Although the total mass of the outer crust is slightly model dependent, its thickness is essentially the same for all four models.

  15. HRR Upgrade to mass loss calorimeter and modified Schlyter test for FR Wood

    Treesearch

    Mark A. Dietenberger; Charles R. Boardman

    2013-01-01

    Enhanced Heat Release Rate (HRR) methodology has been extended to the Mass Loss Calorimeter (MLC) and the Modified Schlyter flame spread test to evaluate fire retardant effectiveness used on wood based materials. Modifications to MLC include installation of thermopile on the chimney walls to correct systematic errors to the sensible HRR calculations to account for...

  16. Effects of Lumbar Spine Assemblies and Body-Borne Equipment Mass on Anthropomorphic Test Device Responses During Drop Tests.

    PubMed

    Aggromito, Daniel; Jaffrey, Mark; Chhor, Allen; Chen, Bernard; Yan, Wenyi

    2017-10-01

    When simulating or conducting land mine blast tests on armored vehicles to assess potential occupant injury, the preference is to use the Hybrid III anthropomorphic test device (ATD). In land blast events, neither the effect of body-borne equipment (BBE) on the ATD response nor the dynamic response index (DRI) is well understood. An experimental study was carried out using a drop tower test rig, with a rigid seat mounted on a carriage table undergoing average accelerations of 161 g and 232 g over 3 ms. A key aspect of the work looked at the various lumbar spine assemblies available for a Hybrid III ATD. These can result in different load cell orientations for the ATD which in turn can affect the load measurement in the vertical and horizontal planes. Thirty-two tests were carried out using two BBE mass conditions and three variations of ATDs. The latter were the Hybrid III with the curved (conventional) spine, the Hybrid III with the pedestrian (straight) spine, and the Federal Aviation Administration (FAA) Hybrid III which also has a straight spine. The results showed that the straight lumbar spine assemblies produced similar ATD responses in drop tower tests using a rigid seat. In contrast, the curved lumbar spine assembly generated a lower pelvis acceleration and a higher lumbar load than the straight lumbar spine assemblies. The maximum relative displacement of the lumbar spine occurred after the peak loading event, suggesting that the DRI is not suitable for assessing injury when the impact duration is short and an ATD is seated on a rigid seat on a drop tower. The peak vertical lumbar loads did not change with increasing BBE mass because the equipment mass effects did not become a factor during the peak loading event.

  17. Mass property control of a spin stabilized spacecraft with restrictive mission and weight constraints

    NASA Technical Reports Server (NTRS)

    Lang, W. E.; Ardvini, C.

    1985-01-01

    In the primary experiment of the spin stabilized San Marco D/L spacecraft, the drag effects on a light spherical shell coupled to a relatively massive center body will be measured. To achieve the precise mass property control, the centroids of both the shell and the center body must coincide with each other and with the center of pressure of the shell. Precise spin balancing is needed for launch and orbital stability, and the deployable antennas need accurate alignment. Corrective measures, developed after the preliminary mass measurements showed flaws in the mass property control, are described in detail. Inertia booms and a yo-yo despin system were developed as add-on units, spin balance measurements about all three geometric axes were used to define weight minimized correction within the outer shell envelope, and boom tip mass differentials were optimized for the most favorable inertia ratio margin achievable within the mission weight constraints. The weight versus orbital lifetime trade-offs were also considered.

  18. Mass-transfer properties of insulin on core-shell and fully porous stationary phases.

    PubMed

    Lambert, Nándor; Kiss, Ibolya; Felinger, Attila

    2014-10-31

    The mass-transfer properties of three superficially-porous packing materials, with 2.6 and 3.6μm particle and 1.9, 2.6, and 3.2μm inner core diameter, respectively, were investigated and compared with those of fully porous packings with similar particle properties. Several sources of band spreading in the chromatographic bed have been identified and studied according to the general rate model of chromatography. Besides the axial dispersion in the stream of the mobile phase, and the external mass transfer resistance, the intraparticle diffusion was studied in depth. The first absolute and the second central moments of the peaks of human insulin, over a wide range of mobile phase velocities were measured and used for the calculation of the mass-transfer coefficients. The experimental data were also analyzed using the stochastic or molecular dynamic model of Giddings and Eyring. The dissimilarities of the mass-transfer observed in the different columns were identified and evaluated.

  19. Test environments and mechanical properties of Zr-base bulk amorphous alloys

    SciTech Connect

    Liu, C.T.; Heatherly, L.; Easton, D.S.

    1998-07-01

    The mechanical properties of two Zr-base bulk amorphous alloys (BAA), Zr-10Al-30Cu-5Ni (BAA-10) and Zr-10Al-5Ti-17.9Cu-14.6Ni (BAA-11), were studied by both tensile and compressive tests at room temperature in various test environments. The BAA ingots up to 7 mm in diameter were successfully produced by both arc melting and drop casting and induction melting and injection casting. The BAA specimens deformed mainly elastically, followed by catastrophic failure along shear bands. Examination of the fracture region revealed ductile fracture features resulting from a substantial increase in temperature, which was attributable to the conversion of the stored elastic strain energy to heat. Surprisingly, liquid droplets located at major shear-band cracks adjacent to the fracture section were observed, indicating the occurrence of local melting during fracture. The angle orientation of shear bands, shear-band cracks, and fracture surfaces relative to the stress axis is quite different for BAA specimens tested in tension and compression. This suggests that both shear stress and normal stress may play a role in developing shear bands during plastic deformation. The tensile properties of BAAs were found to be insensitive to the test environment at room temperature. However, the reaction of BAAs with distilled water and heavy water was detected by laser desorption mass spectrometry (LDMS). These results suggest that moisture-induced hydrogen embrittlement in BAAs may be masked by catastrophic fracture following shear bands.

  20. Meso-scale testing and development of test procedures to maintain mass balance.

    PubMed

    Bonner, James; Page, Cheryl; Fuller, Chris

    2003-01-01

    The Conrad Blucher Institute for Surveying and Science (Texas A&M University--Corpus Christi) has conducted numerous petroleum experiments at the Shoreline Environmental Research Facility (Corpus Christi, Texas, USA). The meso-scale facility has multiple wave tanks, permitting some control in experimental design of the investigations, but allowing for real-world conditions. This paper outlines the evolution of a materials balance approach in conducting petroleum experiments at the facility. The first attempt at a materials balance was during a 1998 study on the fate/effects of dispersant use on crude oil. Both water column and beach sediment samples were collected. For the materials balance, the defined environmental compartments for oil accumulation were sediments, water column, and the water surface, while the discharge from the tanks was presumed to be the primary sink. The "lessons learned" included a need to quantify oil adhesion to the tank surfaces. This was resolved by adhering strips of the polymer tank lining to the tank sides that could be later removed and extracted for oil. Also, a protocol was needed to quantify any floating oil on the water surface. A water surface (oil slick) quantification protocol was developed, involving the use of solid-phase extraction disks. This protocol was first tested during a shoreline cleaner experiment, and later refined in subsequent dispersant effectiveness studies. The effectiveness tests were designed to simulate shallow embayments which created the need for additional adjustments in the tanks. Since dispersant efficacy is largely affected by hydrodynamics, it was necessary to scale the hydrodynamic conditions of the tanks to those expected in our prototype system (Corpus Christi Bay, Texas). The use of a scaled model permits the experiment to be reproduced and/or evaluated under different conditions. To minimize wave reflection in the tank, a parabolic wave dissipater was built. In terms of materials balance, this

  1. Development of Testing Methodologies for the Mechanical Properties of MEMS

    NASA Technical Reports Server (NTRS)

    Ekwaro-Osire, Stephen

    2003-01-01

    This effort is to investigate and design testing strategies to determine the mechanical properties of MicroElectroMechanical Systems (MEMS) as well as investigate the development of a MEMS Probabilistic Design Methodology (PDM). One item of potential interest is the design of a test for the Weibull size effect in pressure membranes. The Weibull size effect is a consequence of a stochastic strength response predicted from the Weibull distribution. Confirming that MEMS strength is controlled by the Weibull distribution will enable the development of a probabilistic design methodology for MEMS - similar to the GRC developed CARES/Life program for bulk ceramics. However, the primary area of investigation will most likely be analysis and modeling of material interfaces for strength as well as developing a strategy to handle stress singularities at sharp corners, filets, and material interfaces. This will be a continuation of the previous years work. The ultimate objective of this effort is to further develop and verify the ability of the Ceramics Analysis and Reliability Evaluation of Structures Life (CARES/Life) code to predict the time-dependent reliability of MEMS structures subjected to multiple transient loads.

  2. Ethnobotany/ethnopharmacology and mass bioprospecting: issues on intellectual property and benefit-sharing.

    PubMed

    Soejarto, D D; Fong, H H S; Tan, G T; Zhang, H J; Ma, C Y; Franzblau, S G; Gyllenhaal, C; Riley, M C; Kadushin, M R; Pezzuto, J M; Xuan, L T; Hiep, N T; Hung, N V; Vu, B M; Loc, P K; Dac, L X; Binh, L T; Chien, N Q; Hai, N V; Bich, T Q; Cuong, N M; Southavong, B; Sydara, K; Bouamanivong, S; Ly, H M; Thuy, Tran Van; Rose, W C; Dietzman, G R

    2005-08-22

    Ethnobotany/ethnopharmacology has contributed to the discovery of many important plant-derived drugs. Field explorations to seek and document indigenous/traditional medical knowledge (IMK/TMK), and/or the biodiversity with which the IMK/TMK is attached, and its conversion into a commercialized product is known as bioprospecting or biodiversity prospecting. When performed in a large-scale operation, the effort is referred to as mass bioprospecting. Experiences from the mass bioprospecting efforts undertaken by the United States National Cancer Institute, the National Cooperative Drug Discovery Groups (NCDDG) and the International Cooperative Biodiversity Groups (ICBG) programs demonstrate that mass bioprospecting is a complex process, involving expertise from diverse areas of human endeavors, but central to it is the Memorandum of Agreement (MOA) that recognizes issues on genetic access, prior informed consent, intellectual property and the sharing of benefits that may arise as a result of the effort. Future mass bioprospecting endeavors must take heed of the lessons learned from past and present experiences in the planning for a successful mass bioprospecting venture.

  3. Precision Test of the Isobaric Multiplet Mass Equation in the A = 32, T = 2 Quintet

    NASA Astrophysics Data System (ADS)

    Ferrer, R.; Kwiatkowski, A. A.; Bollen, G.; Campbell, C. M.; Folden, C. M., III; Lincoln, D.; Morrissey, D. J.; Pang, G. K.; Prinke, A.; Savory, J.; Schwarz, S.

    2008-10-01

    Masses of the radionuclides ^32,33Si and ^34P and of the stable nuclide ^32S have been measured with the Low Energy Beam and Ion Trap (LEBIT) Penning trap mass spectrometer. Relative mass uncertainties of 3 x 10-8 and better have been achieved. The measured mass value of ^32Si differs from the literature value [1,2] by four standard deviations. The precise mass determination of ^32Si and ^32S have been employed to test the isobaric multiplet mass equation for the A = 32, T= 2 isospin quintet. The experimental results indicate a significant deviation from the quadratic form. This work has been supported by Michigan State University, the NSF under contract number PHY- 0606007, and the DOE under the contract DE-FG02-00ER41144. References: 1. G. Audi, A.H. Wapstra, and C. Thibault, Nucl. Phys. A729 (2003) 337 2. A. Paul, S. R"ottger, A. Zimbal, and U. Keyser, Hyperfine Interact. 132 (2001) 189

  4. Hydrogen exchange-mass spectrometry measures stapled peptide conformational dynamics and predicts pharmacokinetic properties.

    PubMed

    Shi, Xiangguo Eric; Wales, Thomas E; Elkin, Carl; Kawahata, Noriyuki; Engen, John R; Annis, D Allen

    2013-12-03

    Peptide drugs have traditionally suffered from poor pharmacokinetic properties due to their conformational flexibility and the interaction of proteases with backbone amide bonds. "Stapled Peptides" are cyclized using an all-hydrocarbon cross-linking strategy to reinforce their α-helical conformation, yielding improved protease resistance and drug-like properties. Here we demonstrate that hydrogen exchange-mass spectrometry (HX-MS) effectively probes the conformational dynamics of Stapled Peptides derived from the survivin-borealin protein-protein interface and predicts their susceptibility to proteolytic degradation. In Stapled Peptides, amide exchange was reduced by over five orders-of-magnitude versus the native peptide sequence depending on staple placement. Furthermore, deuteration kinetics correlated directly with rates of proteolysis to reveal the optimal staple placement for improved drug properties.

  5. Neutrino mass, proton decay, and neutron oscillations as crucial tests of unification models (A Review)

    PubMed Central

    Marshak, R. E.

    1982-01-01

    Several crucial tests of three popular unification models (of strong, electromagnetic, and weak interactions) are described. The models are SU(5) and SO(10) at the grand unification theory (GUT) level and SU(4)C × SU(2)L × SU(2)R at the partial unification theory (PUT) level. The tests selected for discussion are the finiteness of the neutrino mass in the electron volt region, the decay of protons into antileptons in the range of 1031± yr, and the detectability of neutron oscillations at all. The PUT group can also be tested by establishing the existence of four generations of quarks and leptons.

  6. Revisiting the Bulge-Halo Conspiracy. I. Dependence on Galaxy Properties and Halo Mass

    NASA Astrophysics Data System (ADS)

    Shankar, Francesco; Sonnenfeld, Alessandro; Mamon, Gary A.; Chae, Kyu-Hyun; Gavazzi, Raphael; Treu, Tommaso; Diemer, Benedikt; Nipoti, Carlo; Buchan, Stewart; Bernardi, Mariangela; Sheth, Ravi; Huertas-Company, Marc

    2017-05-01

    We carry out a systematic investigation of the total mass density profile of massive ({log} {M}{star}/{M}⊙ ≳ 11.3) early-type galaxies and its dependence on galactic properties and host halo mass with the aid of a variety of lensing/dynamical data and large mock galaxy catalogs. The latter are produced via semi-empirical models that, by design, are based on just a few basic input assumptions. Galaxies with measured stellar masses, effective radii, and Sérsic indices, are assigned, via abundance matching relations, host dark matter halos characterized by a typical ΛCDM profile. Our main results are as follows. (1) In line with observational evidence, our semi-empirical models naturally predict that the total, mass-weighted density slope at the effective radius γ‧ is not universal, steepening for more compact and/or massive galaxies, but flattening with increasing host halo mass. (2) Models characterized by a Salpeter or variable initial mass function (IMF) and uncontracted dark matter profiles are in good agreement with the data, while a Chabrier IMF and/or adiabatic contractions/expansions of the dark matter halos are highly disfavored. (3) Currently available data on the mass density profiles of very massive galaxies ({log} {M}{star}/{M}⊙ ≳ 12), with {M}{halo}≳ 3× {10}14 {M}⊙ , favor instead models with a stellar profile flatter than a Sérsic one in the very inner regions (r ≲ 3-5 kpc), and a cored NFW or Einasto dark matter profile with median halo concentration a factor of ˜2 or ≲1.3, respectively, higher than those typically predicted by N-body numerical simulations.

  7. Mass spectrometer measurements of test gas composition in a shock tunnel

    NASA Technical Reports Server (NTRS)

    Skinner, K. A.; Stalker, R. J.

    1995-01-01

    Shock tunnels afford a means of generating hypersonic flow at high stagnation enthalpies, but they have the disadvantage that thermochemical effects make the composition of the test flow different to that of ambient air. The composition can be predicted by numerical calculations of the nozzle flow expansion, using simplified thermochemical models and, in the absence of experimental measurements, it has been necessary to accept the results given by these calculations. This note reports measurements of test gas composition, at stagnation enthalpies up to 12.5 MJ.kg(exp -1), taken with a time-of-flight mass spectrometer. Limited results have been obtained in previous measurements. These were taken at higher stagnation enthalpies, and used a quadruple mass spectrometer. The time-of-flight method was preferred here because it enabled a number of complete mass spectra to be obtained in each test, and because it gives good mass resolution over the range of interest with air (up to 50 a.m.a.).

  8. TESTING MASS LOSS IN LARGE MAGELLANIC CLOUD CEPHEIDS USING INFRARED AND OPTICAL OBSERVATIONS. II. PREDICTIONS AND TESTS OF THE OGLE-III FUNDAMENTAL-MODE CEPHEIDS

    SciTech Connect

    Neilson, Hilding R.; Ngeow, Chow-Choong; Kanbur, Shashi M.; Lester, John B.

    2010-06-20

    In this paper, we test the hypothesis that Cepheids have infrared excesses due to mass loss. We fit a model using the mass-loss rate and the stellar radius as free parameters to optical observations from the OGLE-III survey and infrared observations from the Two Micron All Sky Survey and SAGE data sets. The sample of Cepheids has predicted minimum mass-loss rates ranging from 0 to 10{sup -8} M{sub sun} yr{sup -1}, where the rates depend on the chosen dust properties. We use the predicted radii to compute the period-radius relation for LMC Cepheids and to estimate the uncertainty caused by the presence of infrared excess for determining angular diameters with the infrared surface brightness technique. Finally, we calculate the linear and nonlinear period-luminosity (P-L) relations for the LMC Cepheids at VIJHK + IRAC wavelengths and find that the P-L relations are consistent with being nonlinear at infrared wavelengths contrary to previous results.

  9. Cost-Effectiveness between Double and Single Fecal Immunochemical Test(s) in a Mass Colorectal Cancer Screening

    PubMed Central

    Cai, Shan-Rong; Zhu, Hong-Hong; Huang, Yan-Qin; Li, Qi-Long; Ma, Xin-Yuan; Zhang, Su-Zhan; Zheng, Shu

    2016-01-01

    This study investigated the cost-effectiveness between double and single Fecal Immunochemical Test(s) (FIT) in a mass CRC screening. A two-stage sequential screening was conducted. FIT was used as a primary screening test and recommended twice by an interval of one week at the first screening stage. We defined the first-time FIT as FIT1 and the second-time FIT as FIT2. If either FIT1 or FIT2 was positive (+), then a colonoscopy was recommended at the second stage. Costs were recorded and analyzed. A total of 24,419 participants completed either FIT1 or FIT2. The detection rate of advanced neoplasm was 19.2% among both FIT1+ and FIT2+, especially high among men with age ≥55 (27.4%). About 15.4% CRC, 18.9% advanced neoplasm, and 29.9% adenoma missed by FIT1 were detected by FIT2 alone. Average cost was $2,935 for double FITs and $2,121 for FIT1 to detect each CRC and $901 for double FITs and $680 for FIT1 to detect each advanced neoplasm. Double FITs are overall more cost-effective, having significantly higher positive and detection rates with an acceptable higher cost, than single FIT. Double FITs should be encouraged for the first screening in a mass CRC screening, especially in economically and medically underserved populations/areas/countries. PMID:27144171

  10. Cost-Effectiveness between Double and Single Fecal Immunochemical Test(s) in a Mass Colorectal Cancer Screening.

    PubMed

    Cai, Shan-Rong; Zhu, Hong-Hong; Huang, Yan-Qin; Li, Qi-Long; Ma, Xin-Yuan; Zhang, Su-Zhan; Zheng, Shu

    2016-01-01

    This study investigated the cost-effectiveness between double and single Fecal Immunochemical Test(s) (FIT) in a mass CRC screening. A two-stage sequential screening was conducted. FIT was used as a primary screening test and recommended twice by an interval of one week at the first screening stage. We defined the first-time FIT as FIT1 and the second-time FIT as FIT2. If either FIT1 or FIT2 was positive (+), then a colonoscopy was recommended at the second stage. Costs were recorded and analyzed. A total of 24,419 participants completed either FIT1 or FIT2. The detection rate of advanced neoplasm was 19.2% among both FIT1+ and FIT2+, especially high among men with age ≥55 (27.4%). About 15.4% CRC, 18.9% advanced neoplasm, and 29.9% adenoma missed by FIT1 were detected by FIT2 alone. Average cost was $2,935 for double FITs and $2,121 for FIT1 to detect each CRC and $901 for double FITs and $680 for FIT1 to detect each advanced neoplasm. Double FITs are overall more cost-effective, having significantly higher positive and detection rates with an acceptable higher cost, than single FIT. Double FITs should be encouraged for the first screening in a mass CRC screening, especially in economically and medically underserved populations/areas/countries.

  11. Development Strategies for Herbal Products Reducing the Influence of Natural Variance in Dry Mass on Tableting Properties and Tablet Characteristics

    PubMed Central

    Qusaj, Ylber; Leng, Andreas; Alshihabi, Firas; Krasniqi, Blerim; Vandamme, Thierry

    2012-01-01

    One “Quality by Design” approach is the focus on the variability of the properties of the active substance. This is crucially important for active substances that are obtained from natural resources such as herbal plant material and extracts. In this paper, we present various strategies for the development of herbal products especially taking into account the natural batch-to-batch variability (mainly of the dry mass) of tablets that contain a fixed amount of tincture. The following steps in the development have been evaluated for the outcome of the physico-chemical properties of the resulting tablets and intermediates: concentration of the tincture extracted from Echinacea fresh plant, loading of the concentrate onto an inert carrier, the respective wet granulation and drying step, including milling, and the adjuvant excipients for the tablet compression step. The responses that were investigated are the mean particle size of the dried and milled granulates, compaction properties and disintegration time of the tablets. Increased particle size showed a significant increase of the disintegration time and a decrease of the compaction properties. In addition, our results showed that the particle size has a great dependency on the ratio of liquid to carrier during the wet granulation process. Thus, the variability of the respective parameters tested was influenced by the performed strategies, which is how the tincture correlated to its dry mass and the relation of the amount of carrier used. In order to optimize these parameters, a strategy considering the above-mentioned points has to be chosen. PMID:24300367

  12. Testes Mass, but Not Sperm Length, Increases with Higher Levels of Polyandry in an Ancient Sex Model

    PubMed Central

    Vrech, David E.; Olivero, Paola A.; Mattoni, Camilo I.; Peretti, Alfredo V.

    2014-01-01

    There is strong evidence that polyandrous taxa have evolved relatively larger testes than monogamous relatives. Sperm size may either increase or decrease across species with the risk or intensity of sperm competition. Scorpions represent an ancient direct mode with spermatophore-mediated sperm transfer and are particularly well suited for studies in sperm competition. This work aims to analyze for the first time the variables affecting testes mass, ejaculate volume and sperm length, according with their levels of polyandry, in species belonging to the Neotropical family Bothriuridae. Variables influencing testes mass and sperm length were obtained by model selection analysis using corrected Akaike Information Criterion. Testes mass varied greatly among the seven species analyzed, ranging from 1.6±1.1 mg in Timogenes dorbignyi to 16.3±4.5 mg in Brachistosternus pentheri with an average of 8.4±5.0 mg in all the species. The relationship between testes mass and body mass was not significant. Body allocation in testes mass, taken as Gonadosomatic Index, was high in Bothriurus cordubensis and Brachistosternus ferrugineus and low in Timogenes species. The best-fitting model for testes mass considered only polyandry as predictor with a positive influence. Model selection showed that body mass influenced sperm length negatively but after correcting for body mass, none of the variables analyzed explained sperm length. Both body mass and testes mass influenced spermatophore volume positively. There was a strong phylogenetic effect on the model containing testes mass. As predicted by the sperm competition theory and according to what happens in other arthropods, testes mass increased in species with higher levels of sperm competition, and influenced positively spermatophore volume, but data was not conclusive for sperm length. PMID:24736525

  13. Testes mass, but not sperm length, increases with higher levels of polyandry in an ancient sex model.

    PubMed

    Vrech, David E; Olivero, Paola A; Mattoni, Camilo I; Peretti, Alfredo V

    2014-01-01

    There is strong evidence that polyandrous taxa have evolved relatively larger testes than monogamous relatives. Sperm size may either increase or decrease across species with the risk or intensity of sperm competition. Scorpions represent an ancient direct mode with spermatophore-mediated sperm transfer and are particularly well suited for studies in sperm competition. This work aims to analyze for the first time the variables affecting testes mass, ejaculate volume and sperm length, according with their levels of polyandry, in species belonging to the Neotropical family Bothriuridae. Variables influencing testes mass and sperm length were obtained by model selection analysis using corrected Akaike Information Criterion. Testes mass varied greatly among the seven species analyzed, ranging from 1.6 ± 1.1 mg in Timogenes dorbignyi to 16.3 ± 4.5 mg in Brachistosternus pentheri with an average of 8.4 ± 5.0 mg in all the species. The relationship between testes mass and body mass was not significant. Body allocation in testes mass, taken as Gonadosomatic Index, was high in Bothriurus cordubensis and Brachistosternus ferrugineus and low in Timogenes species. The best-fitting model for testes mass considered only polyandry as predictor with a positive influence. Model selection showed that body mass influenced sperm length negatively but after correcting for body mass, none of the variables analyzed explained sperm length. Both body mass and testes mass influenced spermatophore volume positively. There was a strong phylogenetic effect on the model containing testes mass. As predicted by the sperm competition theory and according to what happens in other arthropods, testes mass increased in species with higher levels of sperm competition, and influenced positively spermatophore volume, but data was not conclusive for sperm length.

  14. An optimal property of the repeated significance test

    PubMed Central

    Lerche, Hans Rudolf

    1986-01-01

    It is shown that the repeated significance test is a Bayes test for testing sequentially the sign of the drift of a Brownian motion. Its relation to Wald's sequential probability ratio test is studied. PMID:16593662

  15. The seismic properties of low-mass He-core white dwarf stars

    NASA Astrophysics Data System (ADS)

    Córsico, A. H.; Romero, A. D.; Althaus, L. G.; Hermes, J. J.

    2012-11-01

    Context. In recent years, many low-mass (≲ 0.45 M⊙) white dwarf stars expected to harbor He cores have been detected in the field of the Milky Way and in several galactic globular and open clusters. Until recently, no objects of this kind showed pulsations. This situation has changed recently with the exciting discovery of SDSS J184037.78+642312.3, the first pulsating low-mass white dwarf star. Aims: Motivated by this extremely important finding, and in view of the very valuable asteroseismological potential of these objects, we present here a detailed pulsational study applied to low-mass He-core white dwarfs with masses ranging from 0.17 to 0.46 M⊙, based on full evolutionary models representative of these objects. This study is aimed to provide a theoretical basis from which to interpret future observations of variable low-mass white dwarfs. Methods: The background stellar models on which our pulsational analysis was carried out were derived by taking into account the complete evolutionary history of the progenitor stars, with special emphasis on the diffusion processes acting during the white dwarf cooling phase. We computed nonradial g-modes to assess the dependence of the pulsational properties of these objects with stellar parameters such as the stellar mass and the effective temperature, and also with element diffusion processes. We also performed a g- and p-mode pulsational stability analysis on our models and found well-defined blue edges of the instability domain, where these stars should start to exhibit pulsations. Results: We found substantial differences in the seismic properties of white dwarfs with M∗ ≳ 0.20 M⊙ and the extremely low-mass (ELM) white dwarfs (M∗ ≲ 0.20 M⊙). Specifically, g-mode pulsation modes in ELM white dwarfs mainly probe the core regions and are not dramatically affected by mode-trapping effects by the He/H interface, whereas the opposite is true for more massive He-core white dwarfs. We found that element

  16. Physical properties of low-mass star-forming galaxies at intermediate redshifts (z <1)

    NASA Astrophysics Data System (ADS)

    Gallego, J.; Rodríguez-Muñoz, L.; Pacifici, C.; Tresse, L.; Charlot, S.; Gil de Paz, A.; Barro, G.; Villar, V.

    2015-05-01

    In this poster we present the physical properties of a sample of low-mass star-forming galaxies at intermediate redshifts (z<1). We selected a population of dwarf galaxies because dwarf galaxies play a key role in galaxy formation and evolution: (1) they resemble the first structures that hierarchical models predict to form first in the Universe (Dekel & Silk 1986) and that are responsible for the reionization process (Bouwens et al. 2012); and (2) the way or epoch they form and how they evolve are still open questions of modern astrophysics. We selected the sample on the CDFS field. Photometry (40 bands, from UV to far-IR) and preliminary photometric redshifts and stellar masses were obtained from RAINBOW database (Pérez-González et al. 2008). Morphology fom Griffith et al. (2012). Main selection was done by stellar mass, selecting those galaxies with stellar mass M_*<10^8 {M}_⊙. Spectroscopic redshifts were obtained from deep (4 h) MOS spectroscopy with the VIMOS spectrograph at VLT. The average spectrum is characterized by a faint, blue and flat continuum and strong emission lines, revealing that the systems are dominated by an undergoing star formation burst. SFRs and stellar masses are consistent with the SF main-squence over a 2 dex range. More massive objects show higher SFRs than low-mass objects, following the SF main sequence. Distant dwarfs and BCDs follow the overall star-forming sequence in the excitation-luminosity diagram, populating the high excitation, low metallicity and high strength region.

  17. Effective-mass model and magneto-optical properties in hybrid perovskites

    NASA Astrophysics Data System (ADS)

    Yu, Z. G.

    2016-06-01

    Hybrid inorganic-organic perovskites have proven to be a revolutionary material for low-cost photovoltaic applications. They also exhibit many other interesting properties, including giant Rashba splitting, large-radius Wannier excitons, and novel magneto-optical effects. Understanding these properties as well as the detailed mechanism of photovoltaics requires a reliable and accessible electronic structure, on which models of transport, excitonic, and magneto-optical properties can be efficiently developed. Here we construct an effective-mass model for the hybrid perovskites based on the group theory, experiment, and first-principles calculations. Using this model, we relate the Rashba splitting with the inversion-asymmetry parameter in the tetragonal perovskites, evaluate anisotropic g-factors for both conduction and valence bands, and elucidate the magnetic-field effect on photoluminescence and its dependence on the intensity of photoexcitation. The diamagnetic effect of exciton is calculated for an arbitrarily strong magnetic field. The pronounced excitonic peak emerged at intermediate magnetic fields in cyclotron resonance is assigned to the 3D±2 states, whose splitting can be used to estimate the difference in the effective masses of electron and hole.

  18. Effective-mass model and magneto-optical properties in hybrid perovskites.

    PubMed

    Yu, Z G

    2016-06-24

    Hybrid inorganic-organic perovskites have proven to be a revolutionary material for low-cost photovoltaic applications. They also exhibit many other interesting properties, including giant Rashba splitting, large-radius Wannier excitons, and novel magneto-optical effects. Understanding these properties as well as the detailed mechanism of photovoltaics requires a reliable and accessible electronic structure, on which models of transport, excitonic, and magneto-optical properties can be efficiently developed. Here we construct an effective-mass model for the hybrid perovskites based on the group theory, experiment, and first-principles calculations. Using this model, we relate the Rashba splitting with the inversion-asymmetry parameter in the tetragonal perovskites, evaluate anisotropic g-factors for both conduction and valence bands, and elucidate the magnetic-field effect on photoluminescence and its dependence on the intensity of photoexcitation. The diamagnetic effect of exciton is calculated for an arbitrarily strong magnetic field. The pronounced excitonic peak emerged at intermediate magnetic fields in cyclotron resonance is assigned to the 3D±2 states, whose splitting can be used to estimate the difference in the effective masses of electron and hole.

  19. Reconnection Properties of Large-scale Current Sheets During Coronal Mass Ejection Eruptions

    NASA Astrophysics Data System (ADS)

    Lynch, B. J.; Edmondson, J. K.; Kazachenko, M. D.; Guidoni, S. E.

    2016-07-01

    We present a detailed analysis of the properties of magnetic reconnection at large-scale current sheets (CSs) in a high cadence version of the Lynch & Edmondson 2.5D MHD simulation of sympathetic magnetic breakout eruptions from a pseudostreamer source region. We examine the resistive tearing and break-up of the three main CSs into chains of X- and O-type null points and follow the dynamics of magnetic island growth, their merging, transit, and ejection with the reconnection exhaust. For each CS, we quantify the evolution of the length-to-width aspect ratio (up to ˜100:1), Lundquist number (˜103), and reconnection rate (inflow-to-outflow ratios reaching ˜0.40). We examine the statistical and spectral properties of the fluctuations in the CSs resulting from the plasmoid instability, including the distribution of magnetic island area, mass, and flux content. We show that the temporal evolution of the spectral index of the reconnection-generated magnetic energy density fluctuations appear to reflect global properties of the CS evolution. Our results are in excellent agreement with recent, high-resolution reconnection-in-a-box simulations even though our CSs’ formation, growth, and dynamics are intrinsically coupled to the global evolution of sequential sympathetic coronal mass ejection eruptions.

  20. Coupled Continuous Time Random Walks for Anomalous Transport in Media Characterized by Heterogeneous Mass Transfer Properties

    NASA Astrophysics Data System (ADS)

    Comolli, A.; Dentz, M.

    2015-12-01

    Solute transport in geological media is in general non-Fickian as it cannot be explained in terms of equivalent homogeneous media. This anomalous character can be traced back to the existence of multiscale heterogeneity and strong correlations within the medium. Here we investigate the impact of fast heterogeneous mass transfer properties as represented by a spatially varying retardation coefficient (mass exchange between mobile and immobile regions, linear sorption-desorption reactions, variable porosity). In order to estimate the effects of spatial correlation, and disorder distribution on the average transport, we consider 2D media characterized by complex multiscale geometries and point distributions of retardation of increasing heterogeneity. Within a Lagrangian framework, we coarse-grain the Langevin equation for the transport of solute particles due to advection and diffusion in the heterogeneous medium. The large-scale transport properties are derived within a stochastic modeling approach by ensemble averaging of the coarse-grained Langevin equation . This approach shows that the effective particle motion can be described by a coupled CTRW that is fully parametrized by the distribution of the retardation coefficient and the spatial medium organization. This allows for the explicit relation of the heterogeneous medium properties to observed anomalous transport in terms of solute dispersion, breakthrough curves and spatial concentration profiles.

  1. Effective-mass model and magneto-optical properties in hybrid perovskites

    PubMed Central

    Yu, Z. G.

    2016-01-01

    Hybrid inorganic-organic perovskites have proven to be a revolutionary material for low-cost photovoltaic applications. They also exhibit many other interesting properties, including giant Rashba splitting, large-radius Wannier excitons, and novel magneto-optical effects. Understanding these properties as well as the detailed mechanism of photovoltaics requires a reliable and accessible electronic structure, on which models of transport, excitonic, and magneto-optical properties can be efficiently developed. Here we construct an effective-mass model for the hybrid perovskites based on the group theory, experiment, and first-principles calculations. Using this model, we relate the Rashba splitting with the inversion-asymmetry parameter in the tetragonal perovskites, evaluate anisotropic g-factors for both conduction and valence bands, and elucidate the magnetic-field effect on photoluminescence and its dependence on the intensity of photoexcitation. The diamagnetic effect of exciton is calculated for an arbitrarily strong magnetic field. The pronounced excitonic peak emerged at intermediate magnetic fields in cyclotron resonance is assigned to the 3D±2 states, whose splitting can be used to estimate the difference in the effective masses of electron and hole. PMID:27338834

  2. Testing sub-gravitational forces on atoms from a miniature in-vacuum source mass

    NASA Astrophysics Data System (ADS)

    Jaffe, Matt; Haslinger, Philipp; Xu, Victoria; Hamilton, Paul; Upadhye, Amol; Elder, Benjamin; Khoury, Justin; Müller, Holger

    2017-10-01

    Traditional gravity measurements use bulk masses to both source and probe gravitational fields. Matter-wave interferometers enable the use of probe masses as small as neutrons, atoms and molecular clusters, but still require fields generated by masses ranging from hundreds of kilograms to the entire Earth. Shrinking the sources would enable versatile configurations, improve positioning accuracy, enable tests for beyond-standard-model (`fifth') forces, and allow observation of non-classical effects of gravity. Here we detect the gravitational force between freely falling caesium atoms and an in-vacuum, miniature (centimetre-sized, 0.19 kg) source mass using atom interferometry. Sensitivity down to gravitational strength forces accesses the natural scale for a wide class of cosmologically motivated scalar field models of modified gravity and dark energy. We improve the limits on two such models, chameleons and symmetrons, by over two orders of magnitude. We expect further tests of dark energy theories, and measurements of Newton's gravitational constant and the gravitational Aharonov-Bohm effect.

  3. Testing a Predictive Theoretical Model for the Mass Loss Rates of Cool Stars

    NASA Astrophysics Data System (ADS)

    Cranmer, Steven R.; Saar, Steven H.

    2011-11-01

    The basic mechanisms responsible for producing winds from cool, late-type stars are still largely unknown. We take inspiration from recent progress in understanding solar wind acceleration to develop a physically motivated model of the time-steady mass loss rates of cool main-sequence stars and evolved giants. This model follows the energy flux of magnetohydrodynamic turbulence from a subsurface convection zone to its eventual dissipation and escape through open magnetic flux tubes. We show how Alfvén waves and turbulence can produce winds in either a hot corona or a cool extended chromosphere, and we specify the conditions that determine whether or not coronal heating occurs. These models do not utilize arbitrary normalization factors, but instead predict the mass loss rate directly from a star's fundamental properties. We take account of stellar magnetic activity by extending standard age-activity-rotation indicators to include the evolution of the filling factor of strong photospheric magnetic fields. We compared the predicted mass loss rates with observed values for 47 stars and found significantly better agreement than was obtained from the popular scaling laws of Reimers, Schröder, and Cuntz. The algorithm used to compute cool-star mass loss rates is provided as a self-contained and efficient computer code. We anticipate that the results from this kind of model can be incorporated straightforwardly into stellar evolution calculations and population synthesis techniques.

  4. Tinetti mobility test is related to muscle mass and strength in non-institutionalized elderly people.

    PubMed

    Curcio, Francesco; Basile, Claudia; Liguori, Ilaria; Della-Morte, David; Gargiulo, Gaetano; Galizia, Gianluigi; Testa, Gianluca; Langellotto, Assunta; Cacciatore, Francesco; Bonaduce, Domenico; Abete, Pasquale

    2016-12-01

    Elderly people are characterized by a high prevalence of falls and sarcopenia. However, the relationship among Tinetti mobility test (TMT) score, a powerful tool to detect elderly people at risk of falls, and sarcopenia is still not thoroughly investigated. Thus, to determine the relationship between TMT score and muscle mass and strength, 337 elderly participants (mean age 77.1 ± 6.9 years) admitted to comprehensive geriatric assessment were enrolled. TMT score, muscle mass by bioimpedentiometer, and muscle strength by grip strength were evaluated. Muscle mass progressively decreased as TMT score decreased (from 15.3 ± 3.7 to 8.8 ± 1.8 kg/m(2); p for trend <0.001). Similarly, muscle strength decreased progressively as Tinetti score decreased (from 34.7 ± 8.0 to 23.7 ± 8.7 kg; p for trend 0.001). Linear regression analysis demonstrated that TMT score is linearly related with muscle mass (y = 4.5x + 0.4, r = 0.61; p < 0.01) and strength (y = 14.0x + 0.8, r = 0.53; p < 0.01). Multivariate analysis confirms the strong relationship between the TMT score and muscle mass (r = 0.48, p = 0.024) and strength (r = 0.39, p = 0.046). The present study indicates that TMT score is significantly related to muscle mass and strength in non-institutionalized elderly participants. This evidence suggests that TMT score, together with evaluation of muscle mass and strength, may identify sarcopenic elderly participants at high risk of falls.

  5. Testing Low-Mass Stellar Models: Three New Detached Eclipsing Binaries below 0.75Msun

    NASA Astrophysics Data System (ADS)

    López-Morales, M.; Shaw, J. S.

    2007-06-01

    Full tests of stellar models below 1Msun have been hindered until now by the scarce number of precise measurements of the stars' most fundamental parameters: their masses and radii. With current observational techniques, the required precision to distinguish between different models (errors < 2-3 %) can only be achieved using detached eclipsing binaries where 1) both stars are similar in mass, i.e. q = M1/M2 ˜ 1.0, and 2) each star is a main sequence object below 1Msun. Until 2003 only three such binaries had been found and analyzed in detail. Two new systems were published in 2005 (Creevey et al.; López-Morales & Ribas), almost doubling the previous number of data points. Here we present preliminary results for 3 new low-mass detached eclipsing binaries. These are the first studied systems from our sample of 41 new binaries (Shaw & López-Morales, this proceedings). We also provide an updated comparison between the Mass-Radius and the Mass-Teff relations predicted by the models and the observational data from detached eclipsing binaries.

  6. TESTING A SCALE-INDEPENDENT METHOD TO MEASURE THE MASS OF BLACK HOLES

    SciTech Connect

    Gliozzi, M.; Titarchuk, L.; Satyapal, S.; Price, D.; Jang, I.

    2011-07-01

    Estimating the black hole mass at the center of galaxies is a fundamental step not only for understanding the physics of accretion, but also for the cosmological evolution of galaxies. Recently, a new method, based solely on X-ray data, was successfully applied to determine the black hole mass in Galactic systems. Since X-rays are thought to be produced via Comptonization process both in stellar and supermassive black holes, in principle, the same method may be applied to estimate the mass in supermassive black holes. In this work we test this hypothesis by performing a systematic analysis of a sample of active galactic nuclei, whose black hole mass has been already determined via reverberation mapping and which possess high-quality XMM-Newton archival data. The good agreement obtained between the black hole masses derived with this novel scaling technique and the reverberation mapping values suggests that this method is robust and works equally well on stellar and supermassive black holes, making it a truly scale-independent technique for black hole determination.

  7. Effects of Mass Fluctuation on Thermal Transport Properties in Bulk Bi2Te3

    NASA Astrophysics Data System (ADS)

    Huang, Ben; Zhai, Pengcheng; Yang, Xuqiu; Li, Guodong

    2016-10-01

    In this paper, we applied large-scale molecular dynamics and lattice dynamics to study the influence of mass fluctuation on thermal transport properties in bulk Bi2Te3, namely thermal conductivity (K), phonon density of state (PDOS), group velocity (v g), and mean free path (l). The results show that total atomic mass change can affect the relevant vibrational frequency on the micro level and heat transfer rate in the macro statistic, hence leading to the strength variation of the anharmonic phonon processes (Umklapp scattering) in the defect-free Bi2Te3 bulk. Moreover, it is interesting to find that the anharmonicity of Bi2Te3 can be also influenced by atomic differences of the structure such as the mass distribution in the primitive cell. Considering the asymmetry of the crystal structure and interatomic forces, it can be concluded by phonon frequency, lifetime, and velocity calculation that acoustic-optical phonon scattering shows the structure-sensitivity to the mass distribution and complicates the heat transfer mechanism, hence resulting in the low lattice thermal conductivity of Bi2Te3. This study is helpful for designing the material with tailored thermal conductivity via atomic substitution.

  8. Study of parametric instability in gravitational wave detectors with silicon test masses

    NASA Astrophysics Data System (ADS)

    Zhang, Jue; Zhao, Chunnong; Ju, Li; Blair, David

    2017-03-01

    Parametric instability is an intrinsic risk in high power laser interferometer gravitational wave detectors, in which the optical cavity modes interact with the acoustic modes of the mirrors, leading to exponential growth of the acoustic vibration. In this paper, we investigate the potential parametric instability for a proposed next generation gravitational wave detector, the LIGO Voyager blue design, with cooled silicon test masses of size 45 cm in diameter and 55 cm in thickness. It is shown that there would be about two unstable modes per test mass at an arm cavity power of 3 MW, with the highest parametric gain of  ∼76. While this is less than the predicted number of unstable modes for Advanced LIGO (∼40 modes with max gain of  ∼32 at the designed operating power of 830 kW), the importance of developing suitable instability suppression schemes is emphasized.

  9. Equilibrium quality and mass flux distributions in an adiabatic three-subchannel test section

    SciTech Connect

    Yadigaroglu, G.; Maganas, A.

    1995-12-01

    An experiment was designed to measure the fully developed quality and mass flux distributions in an adiabatic three-subchannel test section. The three subchannels had the geometrical characteristics of the corner, side, and interior subchannels of a boiling water reactor (BWR-5) rod bundle. Data collected with Refrigerant-114 at pressures ranging from 7 to 14 bars, simulating operation with water in the range 55 to 103 bars are reported. The average mass flux and quality in the test section were in the ranges 1,300 to 1,750 kg/m{sup 2} {center_dot} s and {minus}0.03 to 0.25, respectively. The data are analyzed and presented in various forms.

  10. Born-Oppenheimer approximation for mass scaling of cold-collision properties

    SciTech Connect

    Falke, Stephan; Tiemann, Eberhard; Lisdat, Christian

    2007-07-15

    Asymptotic levels of the A {sup 1}{sigma}{sub u}{sup +} state of the two isotopomers {sup 39}K{sub 2} and {sup 39}K{sup 41}K up to the dissociation limit are investigated with a Doppler-free high resolution laser-spectroscopic experiment in a molecular beam. The observed level structure can be reproduced correctly only if a mass dependent correction term is introduced for the interaction potential. The applied relative correction in the depth of the potential is 10{sup -6}, which is in the order of magnitude expected for corrections of the Born-Oppenheimer approximation. A similar change in ground state potentials might lead to significant changes of mass-scaled properties describing cold collisions like the s-wave scattering length.

  11. Mass spectrum and decay properties of heavy-light mesons: D, Ds, B and Bs mesons

    NASA Astrophysics Data System (ADS)

    Yazarloo, B. H.; Mehraban, H.

    2017-02-01

    We present a study of mass spectrum and decay properties of heavy-light mesons in the non-relativistic potential model. We consider a new type of potential for the mesonic system, the combination of harmonic and Yukawa-type potentials. To obtain the wave function of the system, we use the perturbation method. We take the harmonic term as parent and the Yukawa term as perturbation for the generation of wave function for the meson. For calculating the parent wave function, the Nikiforov-Uvarov (NU) approach is used and thereby we obtained a series solution for the perturbative wave function and then reported the total wave function. With this wave function, we then study the mass spectrum, the decay constant, the leptonic and semileptonic decay widths of heavy-light mesons.

  12. Localization properties of random-mass Dirac fermions from real-space renormalization group.

    PubMed

    Mkhitaryan, V V; Raikh, M E

    2011-06-24

    Localization properties of random-mass Dirac fermions for a realization of mass disorder, commonly referred to as the Cho-Fisher model, are studied on the D-class chiral network. We show that a simple renormalization group (RG) description captures accurately a rich phase diagram: thermal metal and two insulators with quantized σ(xy), as well as transitions (including critical exponents) between them. Our main finding is that, even with small transmission of nodes, the RG block exhibits a sizable portion of perfect resonances. Delocalization occurs by proliferation of these resonances to larger scales. Evolution of the thermal conductance distribution towards a metallic fixed point is synchronized with evolution of signs of transmission coefficients, so that delocalization is accompanied with sign percolation.

  13. Absorption spectrum, mass spectrometric properties, and electronic structure of 1,2-benzoquinone.

    PubMed

    Albarran, Guadalupe; Boggess, William; Rassolov, Vitaly; Schuler, Robert H

    2010-07-22

    Absorption spectrophotometric and mass spectrometric properties of 1,2-benzoquinone, prepared in aqueous solution by the hexachloroiridate(IV) oxidation of catechol and isolated by HPLC, are reported. Its absorption spectrum has a broad moderately intense band in the near UV with an extinction coefficient of 1370 M(-1)cm(-1) at its 389 nm maximum. The oscillator strength of this band contrasts with those of the order-of-magnitude stronger approximately 250 nm bands of most 1,4-benzoquinones. Gaussian analysis of its absorption spectrum indicates that it also has modestly intense higher energy bands in the 250-320 nm region. In atmospheric pressure mass spectrometric studies 1,2-benzoquinone exhibits very strong positive and negative mass 109 signals that result from the addition of protons and hydride ions in APCI and ESI ion sources. It is suggested that the hydride adduct is formed as the result of the highly polar character of ortho-quinone. On energetic collision the hydride adduct loses an H atom to produce the 1,2-benzosemiquinone radical anion. The present studies also show that atmospheric pressure mass spectral patterns observed for catechol are dominated by signals of 1,2-benzoquinone resulting from oxidation of catechol in the ion sources. Computational studies of the electronic structures of 1,2-benzoquinone, its proton and hydride ion adducts, and 1,2-benzosemiquinone radical anion are reported. These computational studies show that the structures of the proton and hydride adducts are similar and indicate that the hydride adduct is the proton adduct of a doubly negatively charged 1,2-benzoquinone. The contrast between the properties of 1,2- and 1,4-benzoquinone provides the basis for considerations on the effects of conjugation in aromatic systems.

  14. Laboratory procedures and data reduction techniques to determine rheologic properties of mass flows

    USGS Publications Warehouse

    Holmes, R.R.; Huizinga, R.J.; Brown, S.M.; Jobson, H.E.

    1993-01-01

    Determining the rheologic properties of coarse- grained mass flows is an important step to mathematically simulate potential inundation zones. Using the vertically rotating flume designed and built by the U.S. Geological Survey, laboratory procedures and subsequent data reduction have been developed to estimate shear stresses and strain rates of various flow materials. Although direct measurement of shear stress and strain rate currently (1992) are not possible in the vertically rotating flume, methods were derived to estimate these values from measurements of flow geometry, surface velocity, and flume velocity.

  15. The fermionic projector in a time-dependent external potential: Mass oscillation property and Hadamard states

    SciTech Connect

    Finster, Felix E-mail: simone.murro@ur.de Murro, Simone E-mail: simone.murro@ur.de Röken, Christian E-mail: simone.murro@ur.de

    2016-07-15

    We give a non-perturbative construction of the fermionic projector in Minkowski space coupled to a time-dependent external potential which is smooth and decays faster than quadratically for large times. The weak and strong mass oscillation properties are proven. We show that the integral kernel of the fermionic projector is of the Hadamard form, provided that the time integral of the spatial sup-norm of the potential satisfies a suitable bound. This gives rise to an algebraic quantum field theory of Dirac fields in an external potential with a distinguished pure quasi-free Hadamard state.

  16. A new class of Fermionic Projectors: Møller operators and mass oscillation properties

    NASA Astrophysics Data System (ADS)

    Drago, Nicoló; Murro, Simone

    2017-09-01

    Recently, a new functional analytic construction of quasi-free states for a self-dual CAR algebra has been presented in Finster and Reintjes (Adv Theor Math Phys 20:1007, 2016). This method relies on the so-called strong mass oscillation property. We provide an example where this requirement is not satisfied, due to the nonvanishing trace of the solutions of the Dirac equation on the horizon of Rindler space, and we propose a modification of the construction in order to weaken this condition. Finally, a connection between the two approaches is built.

  17. Testing the suitability of geologic frameworks for extrapolating hydraulic properties across regional scales

    DOE PAGES

    Mirus, Benjamin B.; Halford, Keith J.; Sweetkind, Donald; ...

    2016-02-18

    The suitability of geologic frameworks for extrapolating hydraulic conductivity (K) to length scales commensurate with hydraulic data is difficult to assess. A novel method is presented for evaluating assumed relations between K and geologic interpretations for regional-scale groundwater modeling. The approach relies on simultaneous interpretation of multiple aquifer tests using alternative geologic frameworks of variable complexity, where each framework is incorporated as prior information that assumes homogeneous K within each model unit. This approach is tested at Pahute Mesa within the Nevada National Security Site (USA), where observed drawdowns from eight aquifer tests in complex, highly faulted volcanic rocks providemore » the necessary hydraulic constraints. The investigated volume encompasses 40 mi3 (167 km3) where drawdowns traversed major fault structures and were detected more than 2 mi (3.2 km) from pumping wells. Complexity of the five frameworks assessed ranges from an undifferentiated mass of rock with a single unit to 14 distinct geologic units. Results show that only four geologic units can be justified as hydraulically unique for this location. The approach qualitatively evaluates the consistency of hydraulic property estimates within extents of investigation and effects of geologic frameworks on extrapolation. Distributions of transmissivity are similar within the investigated extents irrespective of the geologic framework. In contrast, the extrapolation of hydraulic properties beyond the volume investigated with interfering aquifer tests is strongly affected by the complexity of a given framework. As a result, testing at Pahute Mesa illustrates how this method can be employed to determine the appropriate level of geologic complexity for large-scale groundwater modeling.« less

  18. Testing the suitability of geologic frameworks for extrapolating hydraulic properties across regional scales

    SciTech Connect

    Mirus, Benjamin B.; Halford, Keith J.; Sweetkind, Donald; Fenelon, Joseph M.

    2016-02-18

    The suitability of geologic frameworks for extrapolating hydraulic conductivity (K) to length scales commensurate with hydraulic data is difficult to assess. A novel method is presented for evaluating assumed relations between K and geologic interpretations for regional-scale groundwater modeling. The approach relies on simultaneous interpretation of multiple aquifer tests using alternative geologic frameworks of variable complexity, where each framework is incorporated as prior information that assumes homogeneous K within each model unit. This approach is tested at Pahute Mesa within the Nevada National Security Site (USA), where observed drawdowns from eight aquifer tests in complex, highly faulted volcanic rocks provide the necessary hydraulic constraints. The investigated volume encompasses 40 mi3 (167 km3) where drawdowns traversed major fault structures and were detected more than 2 mi (3.2 km) from pumping wells. Complexity of the five frameworks assessed ranges from an undifferentiated mass of rock with a single unit to 14 distinct geologic units. Results show that only four geologic units can be justified as hydraulically unique for this location. The approach qualitatively evaluates the consistency of hydraulic property estimates within extents of investigation and effects of geologic frameworks on extrapolation. Distributions of transmissivity are similar within the investigated extents irrespective of the geologic framework. In contrast, the extrapolation of hydraulic properties beyond the volume investigated with interfering aquifer tests is strongly affected by the complexity of a given framework. As a result, testing at Pahute Mesa illustrates how this method can be employed to determine the appropriate level of geologic complexity for large-scale groundwater modeling.

  19. Testing the suitability of geologic frameworks for extrapolating hydraulic properties across regional scales

    USGS Publications Warehouse

    Mirus, Benjamin B.; Halford, Keith J.; Sweetkind, Donald; Fenelon, Joseph M.

    2016-01-01

    The suitability of geologic frameworks for extrapolating hydraulic conductivity (K) to length scales commensurate with hydraulic data is difficult to assess. A novel method is presented for evaluating assumed relations between K and geologic interpretations for regional-scale groundwater modeling. The approach relies on simultaneous interpretation of multiple aquifer tests using alternative geologic frameworks of variable complexity, where each framework is incorporated as prior information that assumes homogeneous K within each model unit. This approach is tested at Pahute Mesa within the Nevada National Security Site (USA), where observed drawdowns from eight aquifer tests in complex, highly faulted volcanic rocks provide the necessary hydraulic constraints. The investigated volume encompasses 40 mi3 (167 km3) where drawdowns traversed major fault structures and were detected more than 2 mi (3.2 km) from pumping wells. Complexity of the five frameworks assessed ranges from an undifferentiated mass of rock with a single unit to 14 distinct geologic units. Results show that only four geologic units can be justified as hydraulically unique for this location. The approach qualitatively evaluates the consistency of hydraulic property estimates within extents of investigation and effects of geologic frameworks on extrapolation. Distributions of transmissivity are similar within the investigated extents irrespective of the geologic framework. In contrast, the extrapolation of hydraulic properties beyond the volume investigated with interfering aquifer tests is strongly affected by the complexity of a given framework. Testing at Pahute Mesa illustrates how this method can be employed to determine the appropriate level of geologic complexity for large-scale groundwater modeling.

  20. Testing the suitability of geologic frameworks for extrapolating hydraulic properties across regional scales

    NASA Astrophysics Data System (ADS)

    Mirus, Benjamin B.; Halford, Keith; Sweetkind, Don; Fenelon, Joe

    2016-08-01

    The suitability of geologic frameworks for extrapolating hydraulic conductivity ( K) to length scales commensurate with hydraulic data is difficult to assess. A novel method is presented for evaluating assumed relations between K and geologic interpretations for regional-scale groundwater modeling. The approach relies on simultaneous interpretation of multiple aquifer tests using alternative geologic frameworks of variable complexity, where each framework is incorporated as prior information that assumes homogeneous K within each model unit. This approach is tested at Pahute Mesa within the Nevada National Security Site (USA), where observed drawdowns from eight aquifer tests in complex, highly faulted volcanic rocks provide the necessary hydraulic constraints. The investigated volume encompasses 40 mi3 (167 km3) where drawdowns traversed major fault structures and were detected more than 2 mi (3.2 km) from pumping wells. Complexity of the five frameworks assessed ranges from an undifferentiated mass of rock with a single unit to 14 distinct geologic units. Results show that only four geologic units can be justified as hydraulically unique for this location. The approach qualitatively evaluates the consistency of hydraulic property estimates within extents of investigation and effects of geologic frameworks on extrapolation. Distributions of transmissivity are similar within the investigated extents irrespective of the geologic framework. In contrast, the extrapolation of hydraulic properties beyond the volume investigated with interfering aquifer tests is strongly affected by the complexity of a given framework. Testing at Pahute Mesa illustrates how this method can be employed to determine the appropriate level of geologic complexity for large-scale groundwater modeling.

  1. Analgesic properties of Epilobium angustifolium, evaluated by the hot plate test and the writhing test.

    PubMed

    Tita, B; Abdel-Haq, H; Vitalone, A; Mazzanti, G; Saso, L

    2001-01-01

    The analgesic properties of Epilobium angustifolium (Ea), a plant containing flavonoids with anti-inflammatory activity, have not been sufficiently studied so far. Thus, we decided to evaluate, by the classical hot plate test and the writhing test, the analgesic effect of a dry extract of Ea obtained by evaporating a commercially available mother tincture. In the former assay, the effect of Ea (380 mg/kg) was slightly lower than that of morphine (10 mg/kg s.c.). In the writhing test, which is more sensitive for non-steroidal analgesics, the effect of Ea was already significant (P < 0.05) at 95 mg/kg while at doses > or = 190 mg/kg, its activity was similar to that of lysine acetylsalicylate (300 mg/kg). The LD50 of this dry extract of Ea was 1.4+/-0.1 g/kg. Further studies are necessary for the identification of the active principles and the elucidation of their mechanism of action.

  2. Effective Heat and Mass Transport Properties of Anisotropic Porous Ceria for Solar Thermochemical Fuel Generation

    PubMed Central

    Haussener, Sophia; Steinfeld, Aldo

    2012-01-01

    High-resolution X-ray computed tomography is employed to obtain the exact 3D geometrical configuration of porous anisotropic ceria applied in solar-driven thermochemical cycles for splitting H2O and CO2. The tomography data are, in turn, used in direct pore-level numerical simulations for determining the morphological and effective heat/mass transport properties of porous ceria, namely: porosity, specific surface area, pore size distribution, extinction coefficient, thermal conductivity, convective heat transfer coefficient, permeability, Dupuit-Forchheimer coefficient, and tortuosity and residence time distributions. Tailored foam designs for enhanced transport properties are examined by means of adjusting morphologies of artificial ceria samples composed of bimodal distributed overlapping transparent spheres in an opaque medium. PMID:28817039

  3. Effective Heat and Mass Transport Properties of Anisotropic Porous Ceria for Solar Thermochemical Fuel Generation.

    PubMed

    Haussener, Sophia; Steinfeld, Aldo

    2012-01-19

    High-resolution X-ray computed tomography is employed to obtain the exact 3D geometrical configuration of porous anisotropic ceria applied in solar-driven thermochemical cycles for splitting H2O and CO2. The tomography data are, in turn, used in direct pore-level numerical simulations for determining the morphological and effective heat/mass transport properties of porous ceria, namely: porosity, specific surface area, pore size distribution, extinction coefficient, thermal conductivity, convective heat transfer coefficient, permeability, Dupuit-Forchheimer coefficient, and tortuosity and residence time distributions. Tailored foam designs for enhanced transport properties are examined by means of adjusting morphologies of artificial ceria samples composed of bimodal distributed overlapping transparent spheres in an opaque medium.

  4. Examining the relation between rock mass cuttability index and rock drilling properties

    NASA Astrophysics Data System (ADS)

    Yetkin, Mustafa E.; Özfırat, M. Kemal; Yenice, Hayati; Şimşir, Ferhan; Kahraman, Bayram

    2016-12-01

    Drilling rate is a substantial index value in drilling and excavation operations at mining. It is not only a help in determining physical and mechanical features of rocks, but also delivers strong estimations about instantaneous cutting rates. By this way, work durations to be finished on time, proper machine/equipment selection and efficient excavation works can be achieved. In this study, physical and mechanical properties of surrounding rocks and ore zones are determined by investigations carried out on specimens taken from an underground ore mine. Later, relationships among rock mass classifications, drillability rates, cuttability, and abrasivity have been investigated using multi regression analysis. As a result, equations having high regression rates have been found out among instantaneous cutting rates and geomechanical properties of rocks. Moreover, excavation machine selection for the study area has been made at the best possible interval.

  5. Budget impact analysis of chronic kidney disease mass screening test in Japan.

    PubMed

    Kondo, Masahide; Yamagata, Kunihiro; Hoshi, Shu-Ling; Saito, Chie; Asahi, Koichi; Moriyama, Toshiki; Tsuruya, Kazuhiko; Konta, Tsuneo; Fujimoto, Shouichi; Narita, Ichiei; Kimura, Kenjiro; Iseki, Kunitoshi; Watanabe, Tsuyoshi

    2014-12-01

    Our recently published cost-effectiveness study on chronic kidney disease mass screening test in Japan evaluated the use of dipstick test, serum creatinine (Cr) assay or both in specific health checkup (SHC). Mandating the use of serum Cr assay additionally, or the continuation of current policy mandating dipstick test only was found cost-effective. This study aims to examine the affordability of previously suggested reforms. Budget impact analysis was conducted assuming the economic model would be good for 15 years and applying a population projection. Costs expended by social insurers without discounting were counted as budgets. Annual budget impacts of mass screening compared with do-nothing scenario were calculated as ¥79-¥-1,067 million for dipstick test only, ¥2,505-¥9,235 million for serum Cr assay only and ¥2,517-¥9,251 million for the use of both during a 15-year period. Annual budget impacts associated with the reforms were calculated as ¥975-¥4,129 million for mandating serum Cr assay in addition to the currently used mandatory dipstick test, and ¥963-¥4,113 million for mandating serum Cr assay only and abandoning dipstick test. Estimated values associated with the reform from ¥963-¥4,129 million per year over 15 years are considerable amounts of money under limited resources. The most impressive finding of this study is the decreasing additional expenditures in dipstick test only scenario. This suggests that current policy which mandates dipstick test only would contain medical care expenditure.

  6. Sensitivity of simulated snow cloud properties to mass-diameter parameterizations.

    NASA Astrophysics Data System (ADS)

    Duffy, G.; Nesbitt, S. W.; McFarquhar, G. M.

    2015-12-01

    Mass to diameter (m-D) relationships are used in model parameterization schemes to represent ice cloud microphysics and in retrievals of bulk cloud properties from remote sensing instruments. One of the most common relationships, used in the current Global Precipitation Measurement retrieval algorithm for example, assigns the density of snow as a constant tenth of the density of ice (0.1g/m^3). This assumption stands in contrast to the results of derived m-D relationships of snow particles, which imply decreasing particle densities at larger sizes and result in particle masses orders of magnitude below the constant density relationship. In this study, forward simulations of bulk cloud properties (e.g., total water content, radar reflectivity and precipitation rate) derived from measured size distributions using several historical m-D relationships are presented. This expands upon previous studies that mainly focused on smaller ice particles because of the examination of precipitation-sized particles here. In situ and remote sensing data from the GPM Cold season Experiment (GCPEx) and Canadian CloudSAT/Calypso Validation Program (C3VP), both synoptic snowstorm field experiments in southern Ontario, Canada, are used to evaluate the forward simulations against total water content measured by the Nevzorov and Cloud Spectrometer and Impactor (CSI) probe, radar reflectivity measured by a C band ground based radar and a nadir pointing Ku/Ka dual frequency airborne radar, and precipitation rate measured by a 2D video disdrometer. There are differences between the bulk cloud properties derived using varying m-D relations, with constant density assumptions producing results differing substantially from the bulk measured quantities. The variability in bulk cloud properties derived using different m-D relations is compared against the natural variability in those parameters seen in the GCPEx and C3VP field experiments.

  7. The evaluation of properties of coal mass from the viewpoint of environment

    SciTech Connect

    Foniok, R.; Lukes, M.

    1995-12-01

    This paper deals with the evaluation of several various coal kinds from the Czech coalfields from the viewpoint of the development of thermal processes in coal mass due to their tendency towards self- ignition during storing. In such a case that no self-ignition during storing occurs, gaseous products are liberated into air, the quantity and composition of which depend upon fuel type and its temperature as well. From the environmental viewpoint, substances washed from stored coal are of a certain interest, too. In accordance with this fact, the importance of measures against self-heating of stored coal mass and the importance of a detailed observation of coal quality are concluded. The tables, which compare various coal kinds from the viewpoint of their behavior at self-ignition processes, are the integral part of this presented paper. Our greatest attention is paid to both the quantity and composition of gases being liberated in dependence upon the temperature of coal mass, and at its crushing with regard to selected methods and means of milling circuits before and explosion. Oxygen sorption by means of coal mass is also observed, being of a great importance for self-inertization of closed tanks. All the above-mentioned processes are demonstrated in form of graphic plots. Qualitative signs of coal mass are the basic means for its assessment from the viewpoint of emissions at burning/combustion, and the evaluation of explosive properties. A great attention is paid to explosion-proof means being produced in the Czech Republic. These means can be used for protection of milling circuits of power plants and heating plants or for safety systems of combustion chamber by means of insulation to secondary air main. Explosion-proof quci-acting valves, a special type of safety membrane and device for explosion suppression nip in the bud do represent the latest explosion-proof means.

  8. Mapping the mechanical properties of rocks using automated microindentation tests

    NASA Astrophysics Data System (ADS)

    Masson, Yder; Pride, Steven R.

    2015-10-01

    A microindentation scanner is constructed that measures the spatial fluctuation in the elastic properties of natural rocks. This novel instrument performs automated indentation tests on the surface of a rock slab and outputs 2-D maps of the indentation modulus at submillimeter resolution. Maps obtained for clean, well-consolidated, sandstone are presented and demonstrate the capabilities of the instrument. We observe that the elastic structure of sandstones correlates well with their visual appearance. Further, we show that the probability distribution of the indentation modulus fluctuations across the slab surfaces can be modeled using a lognormal probability density function. To illustrate possible use of the data obtained with the microindentation scanner, we use roughly 10 cm × 10 cm scans with millimeter resolution over four sandstone planar slabs to numerically compute the overall drained elastic moduli for each sandstone sample. We show that such numerically computed moduli are well modeled using the multicomponent form of the Hashin-Shtrikman lower bound that employs the observed lognormal probability distribution for the mesoscopic-scale moduli (the geometric mean works almost the same). We also compute the seismic attenuation versus frequency associated with wave-induced fluid flow between the heterogeneities in the scanned sandstones and observe relatively small values for the inverse quality factor (Q-1<10-2) in the seismic frequency band 102 Hz

  9. Anisotropic Effective Mass, Optical Property, and Enhanced Band Gap in BN/Phosphorene/BN Heterostructures.

    PubMed

    Hu, Tao; Hong, Jisang

    2015-10-28

    Phosphorene is receiving great research interests because of its peculiar physical properties. Nonetheless, the phosphorus has a trouble of degradation due to oxidation. Hereby, we propose that the electrical and optical anisotropic properties can be preserved by encapsulating into hexagonal boron nitride (h-BN). We found that the h-BN contributed to enhancing the band gap of the phosphorene layer. Comparing the band gap of the pristine phosphorene layer, the band gap of the phosphorene/BN(1ML) system was enhanced by 0.15 eV. It was further enhanced by 0.31 eV in the BN(1ML)/phosphorene/BN(1ML) trilayer structure. However, the band gap was not further enhanced when we increased the thickness of the h-BN layers even up to 4 MLs. Interestingly, the anisotropic effective mass and optical property were still preserved in BN/phosphorene/BN heterostructures. Overall, we predict that the capping of phosphorene by the h-BN layers can be an excellent solution to protect the intrinsic properties of the phosphorene.

  10. A modified triple test for palpable breast masses: the value of ultrasound and core needle biopsy.

    PubMed

    Wai, Christina J; Al-Mubarak, Ghada; Homer, Marc J; Goldkamp, Allison; Samenfeld-Specht, Marja; Lee, Yoojin; Logvinenko, Tanya; Rothschild, Janice G; Graham, Roger A

    2013-03-01

    The original triple test score (TTS)--clinical examination, mammogram, and fine-needle aspiration (FNA) biopsy--has long been used to evaluate palpable breast masses. We modified the original TTS to include ultrasound (US) and core biopsy to determine their role in evaluating palpable breast masses. A retrospective chart review of 320 female patients was performed. We developed a modified triple test score (mTTS) that included physical examination, mammogram and/or US, and FNA and/or core biopsy. For the examination and imaging score, 1-3 points were given for low, moderate, or high suspicion. Biopsy scores were characterized as benign, atypical, or malignant. Final outcome was determined by open biopsy or follow-up greater than 1 year. Physical examination was 92% accurate (95% confidence interval [CI] 0.89-0.96, p < 0.0001) at predicting whether a mass was benign or malignant. Imaging was 88% accurate (95% CI 0.84-0.92, p < 0.0001) and needle biopsy was 95% accurate (95% CI 0.92-0.98, p < 0.0001). The modified triple test was 99% accurate (95% CI 0.98-1.00, p < 0.0001). Each 1-point increment in the mTTS was associated with an increased risk of cancer, with an odds ratio of 9.73 (CI 5.16-18.4, p < 0.0001). For 150 patients, we compared the original TTS with the mTTS. US and core biopsy changed the scores of 24 patients; only three changed clinical management. For patients with a palpable breast mass and a mTTS score of 3-4, no further assessment is necessary. Those with a mTTS of 8-9 can proceed to definitive therapy. Patients with a mTTS of 5-7 require further assessment. US and/or core biopsy added little to the accuracy or predictive value of the original TTS.

  11. Active and passive seismic methods for characterization and monitoring of unstable rock masses: field surveys, laboratory tests and modeling.

    NASA Astrophysics Data System (ADS)

    Colombero, Chiara; Baillet, Laurent; Comina, Cesare; Jongmans, Denis; Vinciguerra, Sergio

    2016-04-01

    Appropriate characterization and monitoring of potentially unstable rock masses may provide a better knowledge of the active processes and help to forecast the evolution to failure. Among the available geophysical methods, active seismic surveys are often suitable to infer the internal structure and the fracturing conditions of the unstable body. For monitoring purposes, although remote-sensing techniques and in-situ geotechnical measurements are successfully tested on landslides, they may not be suitable to early forecast sudden rapid rockslides. Passive seismic monitoring can help for this purpose. Detection, classification and localization of microseismic events within the prone-to-fall rock mass can provide information about the incipient failure of internal rock bridges. Acceleration to failure can be detected from an increasing microseismic event rate. The latter can be compared with meteorological data to understand the external factors controlling stability. On the other hand, seismic noise recorded on prone-to-fall rock slopes shows that the temporal variations in spectral content and correlation of ambient vibrations can be related to both reversible and irreversible changes within the rock mass. We present the results of the active and passive seismic data acquired at the potentially unstable granitic cliff of Madonna del Sasso (NW Italy). Down-hole tests, surface refraction and cross-hole tomography were carried out for the characterization of the fracturing state of the site. Field surveys were implemented with laboratory determination of physico-mechanical properties on rock samples and measurements of the ultrasonic pulse velocity. This multi-scale approach led to a lithological interpretation of the seismic velocity field obtained at the site and to a systematic correlation of the measured velocities with physical properties (density and porosity) and macroscopic features of the granitic cliff (fracturing, weathering and anisotropy). Continuous

  12. Correlation of Drug-Testing Results - Immunoassay versus Gas Chromatography-Mass Spectrometry.

    PubMed

    Huang, M H; Liu, R H; Chen, Y L; Rhodes, S L

    2006-01-01

    The need for and prevalence of workplace drug-testing programs mandate the development of an effective and efficient two-step test strategy. Successful implementation of the two-step test strategy relies on the establishment of a reasonable correlation between the preliminary and the confirmatory test data and the selection of an appropriate cutoff for each test step. Correlations of test data derived form these two test steps were most commonly studied qualitatively by comparing the positive/negative test result concluded by these two test steps; however, when instrument-based immunoassays (IA) are used in the preliminary test step, the resulting "semiquantitative" and "apparent" concentration of the targeted analyte can be quantitatively correlated to the analyte concentration as determined by gas chromatography-mass spectrometry (GC-MS). Specimens selected for quantitative correlation studies should be clinical specimens with the distributions of metabolites similar to that present in test specimens; if the resulting correlation data are to be used for selecting appropriate/corresponding cutoffs for these two test steps, the concentrations of the targeted analyte in these specimens should also be within a narrow range centering on the proposed GC-MS cutoff concentration. Among the very significant number of reports correlating IA and GC-MS test data, cannabis and urine are the most common drug category and test specimen studied. The degree of correlation between IA and the GC-MS test data varies with the IA reagent manufacturers, and even with manufacture dates/lots of those supplied by the same manufacturer. The most important factors underlying the observed degree of correlation are undoubtedly the cross-reacting characteristics of the antibody and the metabolite distribution pattern of the drug of concern. Over time, specificities of IA reagents have been optimized so that the two-step test strategy can be most effectively and efficiently applied using the

  13. Vadose Zone VOC Mass Transfer Testing At The SRS Miscellaneous Chemical Basin

    SciTech Connect

    Riha, B

    2005-10-30

    will aid in answering the question ''How clean is protective of the environment''? For this study, a field test was developed to measure a mass transfer factor by injecting clean air into the subsurface through a sample port or well and measuring the rebound VOC concentration over time. Interpretation of the he results of these tests will provide a mass transfer rate that will be used to determine the appropriate type of SVE for the area (passive, enhanced or active SVE), a measured field parameter to estimate mass loading to the groundwater, and time frame for cleanup.

  14. Expanding analytical options in sports drug testing: Mass spectrometric detection of prohibited substances in exhaled breath.

    PubMed

    Thevis, Mario; Krug, Oliver; Geyer, Hans; Schänzer, Wilhelm

    2017-08-15

    Continuously refining and advancing the strategies and methods employed in sports drug testing is critical for efficient doping controls. Besides improving and expanding the spectrum of target analytes, alternative test matrices have warranted in-depth evaluation as they commonly allow for minimal-/non-invasive and non-intrusive sample collection. In this study, the potential of exhaled breath (EB) as doping control specimen was assessed. EB collection devices employing a non-woven electret-based air filter unit were used to generate test specimens, simulating a potential future application in doping controls. A multi-analyte sports drug testing approach configured for a subset of 12 model compounds that represent specific classes of substances prohibited in sports (anabolic agents, hormone and metabolic modulators, stimulants, and beta-blockers) was established using unispray liquid chromatography/tandem mass spectrometry (LC/MS/MS) and applied to spiked and elimination study EB samples. The test method was characterized concerning specificity, assay imprecision, and limits of detection. The EB collection device allowed for retaining and extracting all selected model compounds from the EB aerosol. Following elution and concentration, LC/MS/MS analysis enabled detection limits between 5 and 100 pg/filter and imprecisions ranging from 3% to 20% for the 12 selected model compounds. By means of EB samples from patients and participants of administration studies, the elimination of relevant compounds and, thus, their traceability in EB for doping control purposes, was investigated. Besides stimulants such as methylhexaneamine and pseudoephedrine, also the anabolic-androgenic steroid dehydrochloromethyltestosterone, the metabolic modulator meldonium, and the beta-blocker bisoprolol was detected in exhaled breath. The EB aerosol has provided a promising proof-of-concept suggesting the expansion of this testing strategy as a complement to currently utilized sports drug

  15. Novel models on fluid's variable thermo-physical properties for extensive study on convection heat and mass transfer

    NASA Astrophysics Data System (ADS)

    Shang, De-Yi; Zhong, Liang-Cai

    2017-01-01

    Our novel models for fluid's variable physical properties are improved and reported systematically in this work for enhancement of theoretical and practical value on study of convection heat and mass transfer. It consists of three models, namely (1) temperature parameter model, (2) polynomial model, and (3) weighted-sum model, respectively for treatment of temperature-dependent physical properties of gases, temperature-dependent physical properties of liquids, and concentration- and temperature-dependent physical properties of vapour-gas mixture. Two related components are proposed, and involved in each model for fluid's variable physical properties. They are basic physic property equations and theoretical similarity equations on physical property factors. The former, as the foundation of the latter, is based on the typical experimental data and physical analysis. The latter is built up by similarity analysis and mathematical derivation based on the former basic physical properties equations. These models are available for smooth simulation and treatment of fluid's variable physical properties for assurance of theoretical and practical value of study on convection of heat and mass transfer. Especially, so far, there has been lack of available study on heat and mass transfer of film condensation convection of vapour-gas mixture, and the wrong heat transfer results existed in widespread studies on the related research topics, due to ignorance of proper consideration of the concentration- and temperature-dependent physical properties of vapour-gas mixture. For resolving such difficult issues, the present novel physical property models have their special advantages.

  16. A new approach to the correlation of boundary layer mass transfer rates with thermal diffusion and/or variable properties

    NASA Technical Reports Server (NTRS)

    Srivastava, R.; Rosner, D. E.

    1979-01-01

    A rational approach to the correlation of boundary layer mass transport rates, applicable to many commonly encountered laminar flow conditions with thermal diffusion and/or variable properties, is outlined. The correlation scheme builds upon already available constant property blowing/suction solutions by introducing appropriate correction factors to account for the additional ('pseudo' blowing and source) effects identified with variable properties and thermal diffusion. Applications of the scheme to the particular laminar boundary layer mass transfer problems considered herein (alkali and transition metal compound vapor transport) indicates satisfactory accuracy up to effective blowing factors equivalent to about one third of the 'blow off' value. As a useful by-product of the variable property correlation, we extend the heat-mass transfer analogy, for a wide range of Lewis numbers, to include variable property effects.

  17. A new approach to the correlation of boundary layer mass transfer rates with thermal diffusion and/or variable properties

    NASA Technical Reports Server (NTRS)

    Srivastava, R.; Rosner, D. E.

    1979-01-01

    A rational approach to the correlation of boundary layer mass transport rates, applicable to many commonly encountered laminar flow conditions with thermal diffusion and/or variable properties, is outlined. The correlation scheme builds upon already available constant property blowing/suction solutions by introducing appropriate correction factors to account for the additional ('pseudo' blowing and source) effects identified with variable properties and thermal diffusion. Applications of the scheme to the particular laminar boundary layer mass transfer problems considered herein (alkali and transition metal compound vapor transport) indicates satisfactory accuracy up to effective blowing factors equivalent to about one third of the 'blow off' value. As a useful by-product of the variable property correlation, we extend the heat-mass transfer analogy, for a wide range of Lewis numbers, to include variable property effects.

  18. A hybrid approach to urine drug testing using high-resolution mass spectrometry and select immunoassays.

    PubMed

    McMillin, Gwendolyn A; Marin, Stephanie J; Johnson-Davis, Kamisha L; Lawlor, Bryan G; Strathmann, Frederick G

    2015-02-01

    The major objective of this research was to propose a simplified approach for the evaluation of medication adherence in chronic pain management patients, using liquid chromatography time-of-flight (TOF) mass spectrometry, performed in parallel with select homogeneous enzyme immunoassays (HEIAs). We called it a "hybrid" approach to urine drug testing. The hybrid approach was defined based on anticipated positivity rates, availability of commercial reagents for HEIAs, and assay performance, particularly analytical sensitivity and specificity for drug(s) of interest. Subsequent to implementation of the hybrid approach, time to result was compared with that observed with other urine drug testing approaches. Opioids, benzodiazepines, zolpidem, amphetamine-like stimulants, and methylphenidate metabolite were detected by TOF mass spectrometry to maximize specificity and sensitivity of these 37 drug analytes. Barbiturates, cannabinoid metabolite, carisoprodol, cocaine metabolite, ethyl glucuronide, methadone, phencyclidine, propoxyphene, and tramadol were detected by HEIAs that performed adequately and/or for which positivity rates were very low. Time to result was significantly reduced compared with the traditional approach. The hybrid approach to urine drug testing provides a simplified and analytically specific testing process that minimizes the need for secondary confirmation. Copyright© by the American Society for Clinical Pathology.

  19. Observational tests of convective core overshooting in stars of intermediate to high mass in the Galaxy

    NASA Technical Reports Server (NTRS)

    Stothers, Richard B.

    1991-01-01

    This study presents the results of 14 tests for the presence of convective overshooting in large convecting stellar cores for stars with masses of 4-17 solar masses which are members of detached close binary systems and of open clusters in the Galaxy. A large body of theoretical and observational data is scrutinized and subjected to averaging in order to minimize accidental and systematic errors. A conservative upper limit of d/HP less than 0.4 is found from at least four tests, as well as a tighter upper limit of d/HP less than 0.2 from one good test that is subject to only mild restrictions and is based on the maximum observed effective temperature of evolved blue supergiants. It is concluded that any current uncertainty about the distance scale for these stars is unimportant in conducting the present tests for convective core overshooting. The correct effective temperature scale for the B0.5-B2 stars is almost certainly close to one of the proposed hot scales.

  20. Design of virtual display and testing system for moving mass electromechanical actuator

    NASA Astrophysics Data System (ADS)

    Gao, Zhigang; Geng, Keda; Zhou, Jun; Li, Peng

    2015-12-01

    Aiming at the problem of control, measurement and movement virtual display of moving mass electromechanical actuator(MMEA), the virtual testing system of MMEA was developed based on the PC-DAQ architecture and the software platform of LabVIEW, and the comprehensive test task such as drive control of MMEA, tests of kinematic parameter, measurement of centroid position and virtual display of movement could be accomplished. The system could solve the alignment for acquisition time between multiple measurement channels in different DAQ cards, then on this basis, the researches were focused on the dynamic 3D virtual display by the LabVIEW, and the virtual display of MMEA were realized by the method of calling DLL and the method of 3D graph drawing controls. Considering the collaboration with the virtual testing system, including the hardware drive, the measurement software of data acquisition, and the 3D graph drawing controls method was selected, which could obtained the synchronization measurement, control and display. The system can measure dynamic centroid position and kinematic position of movable mass block while controlling the MMEA, and the interface of 3D virtual display has realistic effect and motion smooth, which can solve the problem of display and playback about MMEA in the closed shell.

  1. Mass spectrometry in sports drug testing: Structure characterization and analytical assays.

    PubMed

    Thevis, Mario; Schänzer, Wilhelm

    2007-01-01

    Owing to the sensitive, selective, and unambiguous nature of mass spectrometric analyses, chromatographic techniques interfaced to various kinds of mass spectrometers have become the most frequently employed strategy in the fight against doping. To obtain utmost confidence in analytical assays, mass spectrometric characterization of target analytes and typical dissociation pathways have been utilized as basis for the development of reliable and robust screening as well as confirmation procedures. Methods for qualitative and/or quantitative determinations of prohibited low and high molecular weight drugs have been established in doping control laboratories preferably employing gas or liquid chromatography combined with electron, chemical, or atmospheric pressure ionization followed by analyses using quadrupole, ion trap, linear ion trap, or hyphenated techniques. The versatility of modern mass spectrometers enable specific as well as comprehensive measurements allowing sports drug testing laboratories to determine the misuse of therapeutics such as anabolic-androgenic steroids, stimulants, masking agents or so-called designer drugs in athletes' blood or urine specimens, and a selection of recent developments is summarized in this review.

  2. Test Sample for the Spatially Resolved Quantification of Illicit Drugs on Fingerprints Using Imaging Mass Spectrometry.

    PubMed

    Muramoto, Shin; Forbes, Thomas P; van Asten, Arian C; Gillen, Greg

    2015-01-01

    A novel test sample for the spatially resolved quantification of illicit drugs on the surface of a fingerprint using time-of-flight secondary ion mass spectrometry (ToF-SIMS) and desorption electrospray ionization mass spectrometry (DESI-MS) was demonstrated. Calibration curves relating the signal intensity to the amount of drug deposited on the surface were generated from inkjet-printed arrays of cocaine, methamphetamine, and heroin with a deposited-mass ranging nominally from 10 pg to 50 ng per spot. These curves were used to construct concentration maps that visualized the spatial distribution of the drugs on top of a fingerprint, as well as being able to quantify the amount of drugs in a given area within the map. For the drugs on the fingerprint on silicon, ToF-SIMS showed great success, as it was able to generate concentration maps of all three drugs. On the fingerprint on paper, only the concentration map of cocaine could be constructed using ToF-SIMS and DESI-MS, as the signals of methamphetamine and heroin were completely suppressed by matrix and substrate effects. Spatially resolved quantification of illicit drugs using imaging mass spectrometry is possible, but the choice of substrates could significantly affect the results.

  3. Accretion disks around a mass with quadrupole

    NASA Astrophysics Data System (ADS)

    Abishev, M.; Boshkayev, K.; Quevedo, H.; Toktarbay, S.

    We consider the stability properties of circular orbits of test particles moving around a mass with quadrupole. We show that the quadrupole modifies drastically the properties of an accretion disk made of such test particles.

  4. Influence of air mass origin on aerosol properties at a remote Michigan forest site

    NASA Astrophysics Data System (ADS)

    VanReken, T. M.; Mwaniki, G. R.; Wallace, H. W.; Pressley, S. N.; Erickson, M. H.; Jobson, B. T.; Lamb, B. K.

    2015-04-01

    The northern Great Lakes region of North America is a large, relatively pristine area. To date, there has only been limited study of the atmospheric aerosol in this region. During summer 2009, a detailed characterization of the atmospheric aerosol was conducted at the University of Michigan Biological Station (UMBS) as part of the Community Atmosphere-Biosphere Interactions Experiment (CABINEX). Measurements included particle size distribution, water-soluble composition, and CCN activity. Aerosol properties were strongly dependent on the origin of the air masses reaching the site. For ∼60% of the study period, air was transported from sparsely populated regions to the northwest. During these times aerosol loadings were low, with mean number and volume concentrations of 1630 cm-3 and 1.91 μm3 cm-3, respectively. The aerosol during clean periods was dominated by organics, and exhibited low hygroscopicities (mean κ = 0.18 at s = 0.3%). When air was from more populated regions to the east and south (∼29% of the time), aerosol properties reflected a stronger anthropogenic influence, with 85% greater particle number concentrations, 2.5 times greater aerosol volume, six times more sulfate mass, and increased hygroscopicity (mean k = 0.24 at s = 0.3%). These trends are have the potential to influence forest-atmosphere interactions and should be targeted for future study.

  5. Influence of air mass origin on aerosol properties at a remote Michigan forest site

    DOE PAGES

    VanReken, T. M.; Mwaniki, G. R.; Wallace, H. W.; ...

    2015-02-10

    The northern Great Lakes region of North America is a large, relatively pristine area. To date, there has only been limited study of the atmospheric aerosol in this region. During summer 2009, a detailed characterization of the atmospheric aerosol was conducted at the University of Michigan Biological Station (UMBS) as part of the Community Atmosphere–Biosphere Interactions Experiment (CABINEX). Measurements included particle size distribution, water-soluble composition, and CCN activity. Aerosol properties were strongly dependent on the origin of the air masses reaching the site. For ~60% of the study period, air was transported from sparsely populated regions to the northwest. Duringmore » these times aerosol loadings were low, with mean number and volume concentrations of 1630 cm-3 and 1.91 μm3 cm-3, respectively. The aerosol during clean periods was dominated by organics, and exhibited low hygroscopicities (mean κ = 0.18 at s = 0.3%). When air was from more populated regions to the east and south (~29% of the time), aerosol properties reflected a stronger anthropogenic influence, with 85% greater particle number concentrations, 2.5 times greater aerosol volume, six times more sulfate mass, and increased hygroscopicity (mean к = 0.24 at s = 0.3%). Furthermore, these trends are have the potential to influence forest–atmosphere interactions and should be targeted for future study.« less

  6. Influence of air mass origin on aerosol properties at a remote Michigan forest site

    SciTech Connect

    VanReken, T. M.; Mwaniki, G. R.; Wallace, H. W.; Pressley, S. N.; Erickson, M. H.; Jobson, B. T.; Lamb, B. K.

    2015-02-10

    The northern Great Lakes region of North America is a large, relatively pristine area. To date, there has only been limited study of the atmospheric aerosol in this region. During summer 2009, a detailed characterization of the atmospheric aerosol was conducted at the University of Michigan Biological Station (UMBS) as part of the Community Atmosphere–Biosphere Interactions Experiment (CABINEX). Measurements included particle size distribution, water-soluble composition, and CCN activity. Aerosol properties were strongly dependent on the origin of the air masses reaching the site. For ~60% of the study period, air was transported from sparsely populated regions to the northwest. During these times aerosol loadings were low, with mean number and volume concentrations of 1630 cm-3 and 1.91 μm3 cm-3, respectively. The aerosol during clean periods was dominated by organics, and exhibited low hygroscopicities (mean κ = 0.18 at s = 0.3%). When air was from more populated regions to the east and south (~29% of the time), aerosol properties reflected a stronger anthropogenic influence, with 85% greater particle number concentrations, 2.5 times greater aerosol volume, six times more sulfate mass, and increased hygroscopicity (mean к = 0.24 at s = 0.3%). Furthermore, these trends are have the potential to influence forest–atmosphere interactions and should be targeted for future study.

  7. Temperature effects on mass-scaling exponents in colonial animals: a manipulative test.

    PubMed

    Barneche, Diego R; White, Craig R; Marshall, Dustin J

    2017-01-01

    Body size and temperature are fundamental drivers of ecological processes because they determine metabolic rates at the individual level. Whether these drivers act independently on individual-level metabolic rates remains uncertain. Most studies of intraspecific scaling of unitary organisms must rely on preexisting differences in size to examine its relationship with metabolic rate, thereby potentially confounding size-correlated traits (e.g., age, nutrition) with size, which can affect metabolic rate. Here, we use a size manipulation approach to test whether metabolic mass scaling and temperature dependence interact in four species (two phyla) of colonial marine invertebrates. Size manipulation in colonial organisms allows tests of how ecological processes (e.g., predation) affect individual physiology and consequently population- and community-level energy flux. Body mass and temperature interacted in two species, with one species exhibiting decreased and the other increased mass-scaling exponents with increasing temperature. The allometric scaling of metabolic rate that we observe in three species contrasts with the isometric scaling of ingestion rates observed in some colonial marine invertebrates. Thus, we suggest that the often observed competitive superiority of colonial over unitary organisms may arise because the difference between energy intake and expenditure increases more strongly with size in colonial organisms.

  8. A new class of equivalence principle test masses, with application to SR-POEM

    NASA Astrophysics Data System (ADS)

    Reasenberg, Robert D.

    2014-09-01

    We describe a new class of test masses (TMs) for use in a Galilean test of the equivalence principle, principally in space. These TMs have n\\geqslant 2 vertical bars that are joined by an off-center connector. A pair of TMs will be positioned to have interleaved bars. For n\\geqslant 3, the principal moments of inertia of a TM can be made equal. With their centers of mass aligned, a TM pair shows decreasing susceptibility to differential acceleration from local mass as n increases. For the Sounding Rocket based Principle Of Equivalence Measurement (SR-POEM), the mission requirements are well met with n=3, but not met with n=2. For a 1 kg SR-POEM TM, vibration frequencies can be made to be above 1 kHz and thus not interfere with the operation of the TM suspension system. The SR-POEM housing supports electrodes for a set of capacitance gauges that observes all six kinematic degrees of freedom of each TM.

  9. Effect of seismic waves on the hydro-mechanical properties of fractured rock masses

    NASA Astrophysics Data System (ADS)

    Lak, Meysam; Baghbanan, Alireza; Hashemolhoseini, Hamid

    2017-07-01

    The transmission of seismic waves in a particular region may influence the hydraulic properties of a rock mass, including permeability, which is one of the most important. To determine the effect of a seismic wave on the hydraulic behavior of a fractured rock mass, systematic numerical modeling was conducted. A number of discrete fracture network (DFN) models with a size of 20 m × 20 m were used as geometrical bases, and a discrete element method (DEM) was employed as a numerical simulation tool. Three different boundary conditions without (Type I) and with static (Type II) and dynamic (Type III) loading were performed on the models, and then their permeability was calculated. The results showed that permeability in Type III models was respectively 62.7% and 44.2% higher than in Type I and Type II models. This study indicates that seismic waves can affect deep earth, and, according to the results, seismic waves increase the permeability and change the flow rate patterns in a fractured rock mass.

  10. Core mass at the helium flash from observations and a new bound on neutrino electromagnetic properties

    NASA Technical Reports Server (NTRS)

    Raffelt, Georg G.

    1990-01-01

    Existing measurements of the bolometric magnitudes of the brightest red giants in 26 globular clusters are used to determine the brightness difference between the tip of the red giant branch (on average found to be 0.1 mag brighter than the brightest red giant) and RR Lyrae stars. The metallicity variation of the result agrees perfectly with theoretical predictions. In conjunction with previous determinations of the number ratio of horizontal-branch versus red giant stars, with statistical parallax determinations of RR Lyrae absolute luminosities, and with theoretical predictions based on the Sweigart and Gross evolutionary sequences, this result yields an allowed range for a hypothetical core mass variation relative to the standard results of (0.009 + or - 0.012) solar mass. If neutrinos had anomalous electromagnetic dipole moments, the increased energy loss near the helium flash would lead to an increased core mass. Constraints on neutrino electromagnetic properties are determined from the color-magnitude diagrams of the globular clusters.

  11. Core mass at the helium flash from observations and a new bound on neutrino electromagnetic properties

    NASA Technical Reports Server (NTRS)

    Raffelt, Georg G.

    1990-01-01

    Existing measurements of the bolometric magnitudes of the brightest red giants in 26 globular clusters are used to determine the brightness difference between the tip of the red giant branch (on average found to be 0.1 mag brighter than the brightest red giant) and RR Lyrae stars. The metallicity variation of the result agrees perfectly with theoretical predictions. In conjunction with previous determinations of the number ratio of horizontal-branch versus red giant stars, with statistical parallax determinations of RR Lyrae absolute luminosities, and with theoretical predictions based on the Sweigart and Gross evolutionary sequences, this result yields an allowed range for a hypothetical core mass variation relative to the standard results of (0.009 + or - 0.012) solar mass. If neutrinos had anomalous electromagnetic dipole moments, the increased energy loss near the helium flash would lead to an increased core mass. Constraints on neutrino electromagnetic properties are determined from the color-magnitude diagrams of the globular clusters.

  12. Water mass properties and chemical signatures in the central Mediterranean region

    NASA Astrophysics Data System (ADS)

    Astraldi, M.; Conversano, F.; Civitarese, G.; Gasparini, G. P.; Ribera d'Alcalà, M.; Vetrano, A.

    2002-06-01

    During the last 15 years, the knowledge of Mediterranean physical dynamics as well as of atmospheric forcing underwent a tremendous improvement because of the action within several international programs and the development of remote sensing and modelling approaches. Curiously, it is still very difficult to build up a climatological database for chemical and basic biological parameters for the whole basin because most of the data published in the open literature were preferentially related to meso- to small-scale processes. Within the European Union project Mass Transfer and Ecosystem Response (MATER), systematic measurements of routine chemical parameters, such as dissolved oxygen and nutrients, have been conducted. They will fill the existing gap between physical and chemical information. In this paper, we analyze the hydrographic data from a cruise conducted in the fall 1996 in the Central Mediterranean region and report, for the first time, on oxygen and nutrient concentrations, ranges and distributions. The joint analysis of T- S properties and chemical data also allows a better definition of water mass characteristics in this crucial area and hints at basic mechanisms relevant to water mass transformation and biological production in the basin.

  13. Advantages and Challenges of Dried Blood Spot Analysis by Mass Spectrometry Across the Total Testing Process

    PubMed Central

    Zakaria, Rosita; Allen, Katrina J.; Koplin, Jennifer J.; Roche, Peter

    2016-01-01

    Introduction Through the introduction of advanced analytical techniques and improved throughput, the scope of dried blood spot testing utilising mass spectrometric methods, has broadly expanded. Clinicians and researchers have become very enthusiastic about the potential applications of dried blood spot based mass spectrometric applications. Analysts on the other hand face challenges of sensitivity, reproducibility and overall accuracy of dried blood spot quantification. In this review, we aim to bring together these two facets to discuss the advantages and current challenges of non-newborn screening applications of dried blood spot quantification by mass spectrometry. Methods To address these aims we performed a key word search of the PubMed and MEDLINE online databases in conjunction with individual manual searches to gather information. Keywords for the initial search included; “blood spot” and “mass spectrometry”; while excluding “newborn”; and “neonate”. In addition, databases were restricted to English language and human specific. There was no time period limit applied. Results As a result of these selection criteria, 194 references were identified for review. For presentation, this information is divided into: 1) clinical applications; and 2) analytical considerations across the total testing process; being pre-analytical, analytical and post-analytical considerations. Conclusions DBS analysis using MS applications is now broadly applied, with drug monitoring for both therapeutic and toxicological analysis being the most extensively reported. Several parameters can affect the accuracy of DBS measurement and further bridge experiments are required to develop adjustment rules for comparability between dried blood spot measures and the equivalent serum/plasma values. Likewise, the establishment of independent reference intervals for dried blood spot sample matrix is required. PMID:28149263

  14. Mass spectrometric analysis and aerodynamic properties of various types of combustion-related aerosol particles

    NASA Astrophysics Data System (ADS)

    Schneider, J.; Weimer, S.; Drewnick, F.; Borrmann, S.; Helas, G.; Gwaze, P.; Schmid, O.; Andreae, M. O.; Kirchner, U.

    2006-12-01

    Various types of combustion-related particles in the size range between 100 and 850 nm were analyzed with an aerosol mass spectrometer and a differential mobility analyzer. The measurements were performed with particles originating from biomass burning, diesel engine exhaust, laboratory combustion of diesel fuel and gasoline, as well as from spark soot generation. Physical and morphological parameters like fractal dimension, effective density, bulk density and dynamic shape factor were derived or at least approximated from the measurements of electrical mobility diameter and vacuum aerodynamic diameter. The relative intensities of the mass peaks in the mass spectra obtained from particles generated by a commercial diesel passenger car, by diesel combustion in a laboratory burner, and by evaporating and re-condensing lubrication oil were found to be very similar. The mass spectra from biomass burning particles show signatures identified as organic compounds like levoglucosan but also others which are yet unidentified. The aerodynamic behavior yielded a fractal dimension (Df) of 2.09 +/- 0.06 for biomass burning particles from the combustion of dry beech sticks, but showed values around three, and hence more compact particle morphologies, for particles from combustion of more natural oak. Scanning electron microscope images confirmed the finding that the beech combustion particles were fractal-like aggregates, while the oak combustion particles displayed a much more compact shape. For particles from laboratory combusted diesel fuel, a Df value of 2.35 was found, for spark soot particles, Df [approximate] 2.10. The aerodynamic properties of fractal-like particles from dry beech wood combustion indicate an aerodynamic shape factor [chi] that increases with electrical mobility diameter, and a bulk density of 1.92 g cm-3. An upper limit of [chi] [approximate] 1.2 was inferred for the shape factor of the more compact particles from oak combustion.

  15. Nondestructive characterization of tie-rods by means of dynamic testing, added masses and genetic algorithms

    NASA Astrophysics Data System (ADS)

    Gentilini, C.; Marzani, A.; Mazzotti, M.

    2013-01-01

    The structural characterization of tie-rods is crucial for the safety assessments of historical buildings. The main parameters that characterize the behavior of tie-rods are the tensile force, the modulus of elasticity of the material and the rotational stiffness at both restraints. Several static, static-dynamic and pure dynamic nondestructive methods have been proposed in the last decades to identify such parameters. However, none of them is able to characterize all the four mentioned parameters. To fill this gap, in this work a procedure based on dynamic testing, added masses and genetic algorithms (GA) is proposed. The identification is driven by GA where the objective function is a metric of the discrepancy between the experimentally determined (by dynamic impact testing) and the numerically computed (by a fast and reliable finite element formulation) frequencies of vibration of some modified systems obtained from the tie-rod by adding a concentrated mass in specific positions. It is shown by a comprehensive numerical testing campaign in which several cases spanning from short, low-stressed, and almost hinged tie-rods to long, high-tensioned, and nearly clamped tie-rods, that the proposed strategy is reliable in the identification of the four unknowns. Finally, the procedure has been applied to characterize a metallic tie-rod located in Palazzo Paleotti, Bologna (Italy).

  16. Correction factors for body mass bias in military physical fitness tests.

    PubMed

    Vanderburgh, Paul M

    2007-07-01

    Recent research findings combined with the theoretical laws of biological similarity make the compelling case that all physical fitness test items for the Army, Air Force, and Navy impose a 15 to 20% physiological bias against heavier, not fatter, men and women. Using the published findings that actual scores of muscle and aerobic endurance scale by body mass raised to the 1/3 power, correction factor tables were developed. This correction factor can be multiplied by one's actual score (e.g., push-ups, sit-ups, abdominal crunches, or curl-up repetitions or distance run time) to yield adjusted scores that are free of body mass bias. These adjusted scores eliminate this bias, become better overall indicators of physical fitness relevant to military tasks, are easily applied to the scoring tables used in the present physical fitness tests, and do not reward body fatness. Use of these correction factors should be explored by all military services to contribute to more relevant fitness tests.

  17. A HUPO test sample study reveals common problems in mass spectrometry-based proteomics

    PubMed Central

    Bell, Alexander W.; Deutsch, Eric W.; Au, Catherine E.; Kearney, Robert E.; Beavis, Ron; Sechi, Salvatore; Nilsson, Tommy; Bergeron, John J.M.

    2009-01-01

    We carried out a test sample study to try to identify errors leading to irreproducibility, including incompleteness of peptide sampling, in LC-MS-based proteomics. We distributed a test sample consisting of an equimolar mix of 20 highly purified recombinant human proteins, to 27 laboratories for identification. Each protein contained one or more unique tryptic peptides of 1250 Da to also test for ion selection and sampling in the mass spectrometer. Of the 27 labs, initially only 7 labs reported all 20 proteins correctly, and only 1 lab reported all the tryptic peptides of 1250 Da. Nevertheless, a subsequent centralized analysis of the raw data revealed that all 20 proteins and most of the 1250 Da peptides had in fact been detected by all 27 labs. The centralized analysis allowed us to determine sources of problems encountered in the study, which include missed identifications (false negatives), environmental contamination, database matching, and curation of protein identifications. Improved search engines and databases are likely to increase the fidelity of mass spectrometry-based proteomics. PMID:19448641

  18. Field testing of lake water chemistry with a portable and an AUV-based mass spectrometer.

    PubMed

    Hemond, Harry F; Mueller, Amy V; Hemond, Michael

    2008-10-01

    Two mass spectrometers (MS) are tested for the measurement of volatile substances, such as hydrocarbons and metabolic gases, in natural waters. KOALA is a backpackable MS operated from above the water surface, in which samples are pumped through a flow cell using a syringe. NEREUS is an underwater instrument hosted by an autonomous underwater vehicle (AUV) that is linked to a communications network to provide chemical data in real time. The mass analyzers of the two MS are nearly identical cycloids, and both use flat-plate membrane inlets. Testing took place in an eutrophic, thermally stratified lake exhibiting steep chemical gradients and significant levels of methane. KOALA provided rapid multispecies analysis of dissolved gases, with a detection limit for methane of 0.1 ppm (readily extendable to 0.01 ppm) and savings of time of at least a factor of 10 compared to that of conventional analysis. The AUV-mounted NEREUS additionally provided rapid spatial coverage and the capability of performing chemical surveys autonomously. Tests demonstrated the need for temperature control of a membrane inlet when steep thermal gradients are present in a water body, as well as the benefits of co-locating all sensors on the AUV to avoid interference from chemically different waters entering and draining from the free-flooding outer hull. The ability to measure dissolved volatiles provided by MS offers potential for complementarity with ionic sensors in the study of natural waters, such as in the case of the carbonate system.

  19. Testing the predicted mass-loss bi-stability jump at radio wavelengths

    NASA Astrophysics Data System (ADS)

    Benaglia, P.; Vink, J. S.; Martí, J.; Maíz Apellániz, J.; Koribalski, B.; Crowther, P. A.

    2007-06-01

    Context: Massive stars play a dominant role in the Universe, but one of the main drivers for their evolution, their mass loss, remains poorly understood. Aims: In this study, we test the theoretically predicted mass-loss behaviour as a function of stellar effective temperature across the so-called “bi-stability” jump. Methods: We observe OB supergiants in the spectral range O8-B3 at radio wavelengths to measure their thermal radio flux densities, and complement these measurements with data from the literature. We derive the radio mass-loss rates and wind efficiencies, and compare our results with Hα mass-loss rates and predictions based on radiation-driven wind models. Results: The wind efficiency shows the possible presence of a local maximum around an effective temperature of 21 000 K - in qualitative agreement with predictions. Furthermore, we find that the absolute values of the radio mass-loss rates show good agreement with empirical Hα rates derived assuming homogeneous winds - for the spectral range under consideration. However, the empirical mass-loss rates are larger (by a factor of a few) than the predicted rates from radiation-driven wind theory for objects above the bi-stability jump (BSJ) temperature, whilst they are smaller (by a factor of a few) for stars below the BSJ temperature. The reason for these discrepancies remains as yet unresolved. A new wind momenta-luminosity relation (WLR) for O8-B0 stars has been derived using the radio observations. The validity of the WLR as a function of the fitting parameter related to the force multiplier α_eff (Kudritzki & Puls, 2000, ARA&A, 629) is discussed. Conclusions: Our most interesting finding is that the qualitative behaviour of the empirical wind efficiencies with effective temperature is in line with the predicted behaviour, and this presents the first hint of empirical evidence for the predicted mass-loss bi-stability jump. However, a larger sample of stars around the BSJ needs to be observed

  20. Concentration Dependent Speciation and Mass Transport Properties of Switchable Polarity Solvents

    SciTech Connect

    Aaron D. Wilson; Christopher J. Orme

    2014-12-01

    Tertiary amine switchable polarity solvents (SPS) consisting of predominantly water, tertiary amine, and tertiary ammonium and bicarbonate ions were produced at various concentrations for three different amines: N,N-dimethylcyclohexylamine, N,N-dimethyloctylamine, and 1 cyclohexylpiperidine. For all concentrations, physical properties were measured including viscosity, molecular diffusion coefficients, freezing point depression, and density. Based on these measurements a variation on the Mark Houwink equation was developed to predict the viscosity of any tertiary amine SPS as a function of concentration using the amine’s molecular mass. The observed physical properties allowed the identification of solution state speciation of non-osmotic SPS, where the amine to carbonic acid ratio is significantly greater than one. These results indicate that at most concentrations the stoichiometric excess amine is involved in solvating a proton with two amines. The physical properties of osmotic SPS have consistent concentration dependence behavior over a wide range of concentrations; this consistence suggests osmotic pressures based on low concentrations freezing point studies can be reliably extrapolated to higher concentrations.

  1. Effects of humidity on the interaction between a fused silica test mass and an electrostatic drive

    NASA Astrophysics Data System (ADS)

    Koptsov, D. V.; Prokhorov, L. G.; Mitrofanov, V. P.

    2015-10-01

    Interaction of a fused silica test mass with electric field of an electrostatic drive with interdigitated electrodes and influence of ambient air humidity on this interaction are investigated. The key element of the experimental setup is the fused silica torsional oscillator. Time dependent increase of the torque acting on the oscillator's plate after application of DC voltage to the drive is demonstrated. The torque relaxation is presumably caused by the redistribution of electric charges on the fused silica plate. The numerical model has been developed to compute the time evolution of the plate's surface charge distribution and the corresponding torque.

  2. Comparing interferometry techniques for multi-degree of freedom test mass readout

    NASA Astrophysics Data System (ADS)

    Isleif, Katharina-Sophie; Gerberding, Oliver; Mehmet, Moritz; Schwarze, Thomas S.; Heinzel, Gerhard; Danzmann, Karsten

    2016-05-01

    Laser interferometric readout systems with 1pm/Hz precision over long time scales have successfully been developed for LISA and LISA Pathfinder. Future gravitational physics experiments, for example in the fields of gravitational wave detection and geodesy, will potentially require similar levels of displacement and tilt readouts of multiple test masses in multiple degrees of freedom. In this article we compare currently available classic interferometry schemes with new techniques using phase modulations and complex readout algorithms. Based on a simple example we show that the new techniques have great potential to simplify interferometric readouts.

  3. Cerumen of Australian stingless bees ( Tetragonula carbonaria): gas chromatography-mass spectrometry fingerprints and potential anti-inflammatory properties

    NASA Astrophysics Data System (ADS)

    Massaro, Flavia Carmelina; Brooks, Peter Richard; Wallace, Helen Margaret; Russell, Fraser Donald

    2011-04-01

    Cerumen, or propolis, is a mixture of plant resins enriched with bee secretions. In Australia, stingless bees are important pollinators that use cerumen for nest construction and possibly for colony's health. While extensive research attests to the therapeutic properties of honeybee ( Apis mellifera) propolis, the biological and medicinal properties of Australian stingless bee cerumen are largely unknown. In this study, the chemical and biological properties of polar extracts of cerumen from Tetragonula carbonaria in South East Queensland, Australia were investigated using gas chromatography-mass spectrometry (GC-MS) analyses and in vitro 5-lipoxygenase (5-LOX) cell-free assays. Extracts were tested against comparative (commercial tincture of A. mellifera propolis) and positive controls (Trolox and gallic acid). Distinct GC-MS fingerprints of a mixed diterpenic profile typical of native bee cerumen were obtained with pimaric acid (6.31 ± 0.97%, w/w), isopimaric acid (12.23 ± 3.03%, w/w), and gallic acid (5.79 ± 0.81%, w/w) tentatively identified as useful chemical markers. Characteristic flavonoids and prenylated phenolics found in honeybee propolis were absent. Cerumen extracts from T. carbonaria inhibited activity of 5-LOX, an enzyme known to catalyse production of proinflammatory mediators (IC50 19.97 ± 2.67 μg/ml, mean ± SEM, n = 4). Extracts had similar potency to Trolox (IC50 12.78 ± 1.82 μg/ml), but were less potent than honeybee propolis (IC50 5.90 ± 0.62 μg/ml) or gallic acid (IC50 5.62 ± 0.35 μg/ml, P < 0.001). These findings warrant further investigation of the ecological and medicinal properties of this stingless bee cerumen, which may herald a commercial potential for the Australian beekeeping industry.

  4. Cerumen of Australian stingless bees (Tetragonula carbonaria): gas chromatography-mass spectrometry fingerprints and potential anti-inflammatory properties.

    PubMed

    Massaro, Flavia Carmelina; Brooks, Peter Richard; Wallace, Helen Margaret; Russell, Fraser Donald

    2011-04-01

    Cerumen, or propolis, is a mixture of plant resins enriched with bee secretions. In Australia, stingless bees are important pollinators that use cerumen for nest construction and possibly for colony's health. While extensive research attests to the therapeutic properties of honeybee (Apis mellifera) propolis, the biological and medicinal properties of Australian stingless bee cerumen are largely unknown. In this study, the chemical and biological properties of polar extracts of cerumen from Tetragonula carbonaria in South East Queensland, Australia were investigated using gas chromatography-mass spectrometry (GC-MS) analyses and in vitro 5-lipoxygenase (5-LOX) cell-free assays. Extracts were tested against comparative (commercial tincture of A. mellifera propolis) and positive controls (Trolox and gallic acid). Distinct GC-MS fingerprints of a mixed diterpenic profile typical of native bee cerumen were obtained with pimaric acid (6.31 ± 0.97%, w/w), isopimaric acid (12.23 ± 3.03%, w/w), and gallic acid (5.79 ± 0.81%, w/w) tentatively identified as useful chemical markers. Characteristic flavonoids and prenylated phenolics found in honeybee propolis were absent. Cerumen extracts from T. carbonaria inhibited activity of 5-LOX, an enzyme known to catalyse production of proinflammatory mediators (IC₅₀ 19.97 ± 2.67 μg/ml, mean ± SEM, n = 4). Extracts had similar potency to Trolox (IC₅₀ 12.78 ± 1.82 μg/ml), but were less potent than honeybee propolis (IC₅₀ 5.90 ± 0.62 g/ml) or gallic acid (IC₅₀ 5.62 ± 0.35 μg/ml, P < 0.001). These findings warrant further investigation of the ecological and medicinal properties of this stingless bee cerumen, which may herald a commercial potential for the Australian beekeeping industry.

  5. Estimating initial contaminant mass based on fitting mass-depletion functions to contaminant mass discharge data: Testing method efficacy with SVE operations data

    NASA Astrophysics Data System (ADS)

    Mainhagu, J.; Brusseau, M. L.

    2016-09-01

    The mass of contaminant present at a site, particularly in the source zones, is one of the key parameters for assessing the risk posed by contaminated sites, and for setting and evaluating remediation goals and objectives. This quantity is rarely known and is challenging to estimate accurately. This work investigated the efficacy of fitting mass-depletion functions to temporal contaminant mass discharge (CMD) data as a means of estimating initial mass. Two common mass-depletion functions, exponential and power functions, were applied to historic soil vapor extraction (SVE) CMD data collected from 11 contaminated sites for which the SVE operations are considered to be at or close to essentially complete mass removal. The functions were applied to the entire available data set for each site, as well as to the early-time data (the initial 1/3 of the data available). Additionally, a complete differential-time analysis was conducted. The latter two analyses were conducted to investigate the impact of limited data on method performance, given that the primary mode of application would be to use the method during the early stages of a remediation effort. The estimated initial masses were compared to the total masses removed for the SVE operations. The mass estimates obtained from application to the full data sets were reasonably similar to the measured masses removed for both functions (13 and 15% mean error). The use of the early-time data resulted in a minimally higher variation for the exponential function (17%) but a much higher error (51%) for the power function. These results suggest that the method can produce reasonable estimates of initial mass useful for planning and assessing remediation efforts.

  6. Monitoring water masses properties by Glider in Sardinia Channel during summer 2014

    NASA Astrophysics Data System (ADS)

    Gana, Slim; Iudicone, Daniele; Ghenim, Leila; Mortier, Laurent; Testor, Pierre; Tintoré, Joaquin; Olita, Antonio

    2015-04-01

    1. Summary In the framework of the EC funded project, PERSEUS (WP3, Subtask 3.3.1: Repeated glider sections in key channels and sub-basin) and with the support of JERICO TNA (EU-FP7), a deep water glider (up to 1000m) was deployed from the R/V Tethys in the Sardinia Channel and has carried out 3 return trips during the period spanning from the 16th of August 2014 to the 19th of September 2014. The Gilder was equipped with CTD, O2 sensors, Fluorometers (ChlA), back scattering from 470 to 880 nm and was programmed to follow a path close to SARAL satellite track #887. During this experiment, a significant dataset, as never obtained before for this area, has been collected. The innovation stands in the high spatial resolution, in the temporal repetitivity and in the number of parameters sampled simultaneously. The first step of the work will focuses on the analysis of the hydrological properties of the existing water masses in the area. 2. Frame and aim of the experiment The Sardinia Channel is a zonally oriented passage connecting the Algerian and the Tyrrhenian basins, with a sill depth of about 1900 m. In spite of the considerable amount of work achieved and accurate results obtained about the circulation in the Western Mediterranean Sea, during the last 20 years, the Sardinia Channel is still one of the region where the dynamical processes and water exchanges are not clearly identified. Previous studies (Garzoli S. and C. Maillard, 1979, and Ozturgut Erdogan, 1975) pointed out the complexity of the processes in the region and the role of the bottom topography in sustaining them, and provided a first estimation of the involved fluxes. The main knowledge about the water masses crossing this region mostly concerns the AW (Atlantic Water) and the LIW (Levantine Intermediate Water). Along the Algerian coast, the AW is transported mainly by the Algerian current (AC Millot, 1985) from which the anticyclonic Algerian eddies (AEs, Puillat et al., 2002; Taupier-Letage et al

  7. Elastic properties of graphene obtained by computational mechanical tests

    NASA Astrophysics Data System (ADS)

    Hartmann, Markus A.; Todt, Melanie; Rammerstorfer, Franz G.; Fischer, Franz D.; Paris, Oskar

    2013-09-01

    The basic building block of many carbon nanostructures like fullerenes, carbon onions or nanotubes is the truly two-dimensional material graphene. Commercial finite element codes, widely used to predict the mechanical properties of these structures, rely on the knowledge of the mechanical properties of the basic material. In this paper using an atomistic simulation approach we determine the membrane and bending stiffness of graphene, as well as the corresponding effective parameters: the effective elastic modulus E=2.4\\ \\text{TPa} , Poisson ratio \

  8. Confirmatory tests for drugs in the workplace by gas chromatography-mass spectrometry.

    PubMed

    Goldberger, B A; Cone, E J

    1994-07-15

    The Mandatory Guidelines for Federal Workplace Drug Testing Programs require the use of gas chromatography-mass spectrometry (GC-MS) for the confirmation of presumptive positive urine specimens. This review focuses upon GC-MS methods developed specifically for forensic confirmation of amphetamine, methamphetamine, 11-nor-delta 9-tetrahydrocannabinol-9-carboxylic acid (THC-acid), benzoylecgonine, morphine, codeine and phencyclidine in urine for purposes of workplace drug testing. In addition, current laboratory issues pertaining to each drug class are reviewed. Generally, drug assays utilized either liquid-liquid or solid-phase extraction methods, derivatization if necessary, and GC-MS detection operating in the selected ion monitoring mode or by full scan acquisition.

  9. Influence of Mass Transfer Kinetics on Interpretation of Push-Pull Partitioning Tracer Tests

    NASA Astrophysics Data System (ADS)

    Ervin, R. E.; Boroumand, A.; Abriola, L. M.; Ramsburg, C. A.

    2012-12-01

    There is now considerable interest in predicting plume response to various levels of treatment applied within a DNAPL source zone. An important component to the development of this predictive capability is the ability to characterize the distribution of DNAPL within the source zone. Metrics developed for description of source zone architecture are frequently based upon some combination of downgradient contaminant concentrations and in source testing. One option for in source testing is the use of partition tracers in either interwell or push-pull test configurations. Push-pull tracer tests are advantageous for obtaining more localized information that can be integrated with other observations to reduce the uncertainty related the links between the architecture of a source and its associated plume. Here we examined push-pull tracer tests in a series of aquifer cell experiments to evaluate the potential of this type of test to quantify metrics of the DNAPL distribution at the local-scale (i.e., 1 m flow path). Three DNAPL architectures were characterized by conducting push-pull tracer tests using a solution which comprised three partitioning tracers (1-pentanol, 1-hexanol, and 2-octanol) and one non-partitioning tracer (bromide). Each architecture was characterized using three flow regimes that employed combinations of fast (~30 cm/hr) and slow (~2 cm/hr) velocities. Production curves (i.e., tracer concentrations during the pull phase of the test) for the partitioning tracers were found to be asymmetric. This asymmetry severely degraded the ability of an analytical solution employing the local equilibrium assumption to predict the overall saturations. Saturation estimates from the analytical solution were found to be improved when the application of the model was restricted to later time data (Vext/Vinj >1). This observation suggests it is important to better understand the factors influencing the early time data. Experiments were also simulated using a numerical

  10. PHYSICAL PROPERTIES OF THE LOW-MASS ECLIPSING BINARY NSVS 02502726

    SciTech Connect

    Lee, Jae Woo; Youn, Jae-Hyuck; Kim, Seung-Lee; Lee, Chung-Uk E-mail: jhyoon@kasi.re.kr E-mail: leecu@kasi.re.kr

    2013-01-01

    NSVS 02502726 has been known as a double-lined, detached eclipsing binary that consists of two low-mass stars. We obtained BVRI photometric follow-up observations in 2009 and 2011 to measure improved physical properties of the binary star. Each set of light curves, including the 2008 data given by Cakirli et al., was simultaneously analyzed with the previously published radial velocity curves using the Wilson-Devinney binary code. The conspicuous seasonal light variations of the system are satisfactorily modeled by a two-spot model with one starspot on each component and by changes of the spot parameters with time. Based on 23 eclipse timings calculated from the synthetic model and one ephemeris epoch, an orbital period study of NSVS 02502726 reveals that the period has experienced a continuous decrease of -5.9 Multiplication-Sign 10{sup -7} day yr{sup -1} or a sinusoidal variation with a period and semi-amplitude of 2.51 yr and 0.0011 days, respectively. The timing variations could be interpreted as either the light-travel-time effect due to the presence of an unseen third body, or as the combination of this effect and angular momentum loss via magnetic stellar wind braking. Individual masses and radii of both components are determined to be M{sub 1} = 0.689 {+-} 0.016 M{sub Sun }, M{sub 2} = 0.341 {+-} 0.009 M{sub Sun }, R{sub 1} = 0.707 {+-} 0.007 R{sub Sun }, and R{sub 2} = 0.657 {+-} 0.008 R{sub Sun }. The results are very different from those of Cakirli et al. with the primary's radius (0.674 {+-} 0.006 R{sub Sun }) smaller the secondary's (0.763 {+-} 0.007 R{sub Sun }). We compared the physical parameters presented in this paper with current low-mass stellar models and found that the measured values of the primary star are best fitted to a 79 Myr isochrone. The primary is in good agreement with the empirical mass-radius relation from low-mass binaries, but the secondary is oversized by about 85%.

  11. Thermal properties of holmium-implanted gold films for a neutrino mass experiment with cryogenic microcalorimeters

    SciTech Connect

    Prasai, K.; Yanardag, S. Basak; Galeazzi, M.; Uprety, Y.; Alves, E.; Rocha, J.; Bagliani, D.; Biasotti, M.; Gatti, F.; Gomes, M. Ribeiro

    2013-08-15

    In a microcalorimetric neutrino mass experiment using the radioactive decay of {sup 163}Ho, the radioactive material must be fully embedded in the microcalorimeter absorber. One option that is being investigated is to implant the radioactive isotope into a gold absorber, as gold is successfully used in other applications. However, knowing the thermal properties at the working temperature of microcalorimeters is critical for choosing the absorber material and for optimizing the detector performance. In particular, it is paramount to understand if implanting the radioactive material in gold changes its heat capacity. We used a bolometric technique to measure the heat capacity of gold films, implanted with various concentrations of holmium and erbium (a byproduct of the {sup 163}Ho fabrication), in the temperature range 70 mK–300 mK. Our results show that the specific heat capacity of the gold films is not affected by the implant, making this a viable option for a future microcalorimeter holmium experiment.

  12. Monitoring of Water Masses Properties in the Channel of Sardinia by Glider and Satellites Observations

    NASA Astrophysics Data System (ADS)

    Gana, Slim; Iudicone, Daniele; Ghenim, Leila; Mortier, Laurent; Testor, Pierre; Olita, Antonio; Buongiono-Nardelli, Bruno; Tintore, Joaquin

    2015-12-01

    In the framework of the EC funded project, PERSEUS (Subtask 3.3.1: Repeated glider sections in key channels and sub-basin) and with the support of JERICO TNA (EU-FP7), a deep water glider (up to 1000m) was deployed from the R/V Tethys in the Sardinia Channel and has carried out 3 return trips during the period from the 16th of August 2014 to the 19th of September 2014. The Gilder was programmed to follow a path close to SARAL satellite track #887. In this paper, after an overview of the hydrological properties of the water masses in the area highlighted by the glider data, we are focusing on a joint analysis of in-situ and satellite data to understand the behavior of a cyclonic eddy observed in the area.

  13. Ground state properties of electron-hole bilayer: Mass-asymmetric effect

    NASA Astrophysics Data System (ADS)

    Sharma, R. O.; Saini, L. K.; Bahuguna, Bhagwati Prasad

    2016-11-01

    We study the effects of mass asymmetry on the ground state properties of an electron-hole bilayer (EHBL) system at T =0 by using the quantum Monte Carlo method. Particularly, we use the variational Monte Carlo method to calculate the pair-correlation function g (r ) and the condensation fraction c at a fixed density for different values of interplaner distance d and extract the phases of the EHBL system. We use a single trial wave function that can describe fluid, excitonic, and biexcitonic phases. We find that the excitonic fluid phase is stable in the region of d ≥0.25 a .u . and a transition from the excitonic fluid phase to the biexcitonic fluid phase at d =0.24 a .u .

  14. Upgrade of the Goddard Space Flight Center's Mass Properties Measuring Facility

    NASA Technical Reports Server (NTRS)

    Ross, Brian P.; McLeod, Christopher

    2004-01-01

    Goddard Space Flight Center has a Mass Properties Measuring Facility (MPMF), which is used to measure weight, center of gravity, moment of inertia, and product of inertia of satellites and space flight hardware. The system was originally purchased more than 30 years ago. While the MPMF was still in good mechanical condition, the measurement and control subsystem had begun to experience more frequent component failures. Many of the outdated, discrete components in the system are no longer available for replacement. A decision was made to upgrade the measurement and control subsystem of the MPMF to improve its reliability and reduce the chance of component failures leading to extended facility outages. This paper will describe details of the upgraded subsystems and summarize the new performance capabilities of the system.

  15. Multi-wavelength properties and SMBH's masses of the isolated AGNs in the Local Universe

    NASA Astrophysics Data System (ADS)

    Vavilova, I. B.; Vasylenko, A. A.; Babyk, Iu. V.; Pulatova, N. G.

    2016-08-01

    The sample of 36 nearest isolated AGNs was cross-matched by 2MIG and Veron-Cetty catalogues and limited to Ks ≤ 12.0m and Vr < 15 000 km/s in the northern sky (δ ≥ -15°). These objects were in isolation during ~ 3 Gyrs. For revealing their multi-wavelength properties we used all the available databases obtained with ground-based and space observatories (from radio to X-ray ranges). It is allowed us to separate the internal evolution mechanisms from the environment influence and consider them as two separate processes related to fueling nuclear activity and accretion on the SMBHs outside of the environment. In this report we present briefly main results, which were already published (Pulatova N., Vavilova I., Sawangwit U. et al. The 2MIG isolated AGNs - I. General and multiwavelength properties of AGNs and host galaxies in the northern sky, MNRAS, 447, Issue 3, p. 2209-2223 (2015)). We accentuate that for the first time we revealed that the host isolated galaxies with AGNs of Sy1 type (without faint companions) appear to possess the bar morphological features (e.g., the interaction with neighboring galaxies is not necessary condition for broad-line region formation). We give also current results as concerns with more detail X-ray analysis, emission features and spectral models for several AGNs for which a cumulative soft and hard energy spectrum was reconstructed. The estimates of SMBH masses show that are systematically lower than the SMBH masses of AGNs located in a dense environment.

  16. Charge-Induced Force Noise on Free-Falling Test Masses: Results from LISA Pathfinder

    NASA Astrophysics Data System (ADS)

    Armano, M.; Audley, H.; Auger, G.; Baird, J. T.; Binetruy, P.; Born, M.; Bortoluzzi, D.; Brandt, N.; Bursi, A.; Caleno, M.; Cavalleri, A.; Cesarini, A.; Cruise, M.; Danzmann, K.; de Deus Silva, M.; Diepholz, I.; Dolesi, R.; Dunbar, N.; Ferraioli, L.; Ferroni, V.; Fitzsimons, E. D.; Flatscher, R.; Freschi, M.; Gallegos, J.; García Marirrodriga, C.; Gerndt, R.; Gesa, L.; Gibert, F.; Giardini, D.; Giusteri, R.; Grimani, C.; Grzymisch, J.; Harrison, I.; Heinzel, G.; Hewitson, M.; Hollington, D.; Hueller, M.; Huesler, J.; Inchauspé, H.; Jennrich, O.; Jetzer, P.; Johlander, B.; Karnesis, N.; Kaune, B.; Killow, C. J.; Korsakova, N.; Lloro, I.; Liu, L.; López-Zaragoza, J. P.; Maarschalkerweerd, R.; Madden, S.; Mance, D.; Martín, V.; Martin-Polo, L.; Martino, J.; Martin-Porqueras, F.; Mateos, I.; McNamara, P. W.; Mendes, J.; Mendes, L.; Moroni, A.; Nofrarias, M.; Paczkowski, S.; Perreur-Lloyd, M.; Petiteau, A.; Pivato, P.; Plagnol, E.; Prat, P.; Ragnit, U.; Ramos-Castro, J.; Reiche, J.; Romera Perez, J. A.; Robertson, D. I.; Rozemeijer, H.; Rivas, F.; Russano, G.; Sarra, P.; Schleicher, A.; Slutsky, J.; Sopuerta, C.; Sumner, T. J.; Texier, D.; Thorpe, J. I.; Trenkel, C.; Vetrugno, D.; Vitale, S.; Wanner, G.; Ward, H.; Wass, P. J.; Wealthy, D.; Weber, W. J.; Wittchen, A.; Zanoni, C.; Ziegler, T.; Zweifel, P.; LISA Pathfinder Collaboration

    2017-04-01

    We report on electrostatic measurements made on board the European Space Agency mission LISA Pathfinder. Detailed measurements of the charge-induced electrostatic forces exerted on free-falling test masses (TMs) inside the capacitive gravitational reference sensor are the first made in a relevant environment for a space-based gravitational wave detector. Employing a combination of charge control and electric-field compensation, we show that the level of charge-induced acceleration noise on a single TM can be maintained at a level close to 1.0 fm s-2 Hz-1 /2 across the 0.1-100 mHz frequency band that is crucial to an observatory such as the Laser Interferometer Space Antenna (LISA). Using dedicated measurements that detect these effects in the differential acceleration between the two test masses, we resolve the stochastic nature of the TM charge buildup due to interplanetary cosmic rays and the TM charge-to-force coupling through stray electric fields in the sensor. All our measurements are in good agreement with predictions based on a relatively simple electrostatic model of the LISA Pathfinder instrument.

  17. Model test of anchoring effect on zonal disintegration in deep surrounding rock masses.

    PubMed

    Chen, Xu-Guang; Zhang, Qiang-Yong; Wang, Yuan; Liu, De-Jun; Zhang, Ning

    2013-01-01

    The deep rock masses show a different mechanical behavior compared with the shallow rock masses. They are classified into alternating fractured and intact zones during the excavation, which is known as zonal disintegration. Such phenomenon is a great disaster and will induce the different excavation and anchoring methodology. In this study, a 3D geomechanics model test was conducted to research the anchoring effect of zonal disintegration. The model was constructed with anchoring in a half and nonanchoring in the other half, to compare with each other. The optical extensometer and optical sensor were adopted to measure the displacement and strain changing law in the model test. The displacement laws of the deep surrounding rocks were obtained and found to be nonmonotonic versus the distance to the periphery. Zonal disintegration occurs in the area without anchoring and did not occur in the model under anchoring condition. By contrasting the phenomenon, the anchor effect of restraining zonal disintegration was revealed. And the formation condition of zonal disintegration was decided. In the procedure of tunnel excavation, the anchor strain was found to be alternation in tension and compression. It indicates that anchor will show the nonmonotonic law during suppressing the zonal disintegration.

  18. Charge-Induced Force Noise on Free-Falling Test Masses: Results from LISA Pathfinder.

    PubMed

    Armano, M; Audley, H; Auger, G; Baird, J T; Binetruy, P; Born, M; Bortoluzzi, D; Brandt, N; Bursi, A; Caleno, M; Cavalleri, A; Cesarini, A; Cruise, M; Danzmann, K; de Deus Silva, M; Diepholz, I; Dolesi, R; Dunbar, N; Ferraioli, L; Ferroni, V; Fitzsimons, E D; Flatscher, R; Freschi, M; Gallegos, J; García Marirrodriga, C; Gerndt, R; Gesa, L; Gibert, F; Giardini, D; Giusteri, R; Grimani, C; Grzymisch, J; Harrison, I; Heinzel, G; Hewitson, M; Hollington, D; Hueller, M; Huesler, J; Inchauspé, H; Jennrich, O; Jetzer, P; Johlander, B; Karnesis, N; Kaune, B; Killow, C J; Korsakova, N; Lloro, I; Liu, L; López-Zaragoza, J P; Maarschalkerweerd, R; Madden, S; Mance, D; Martín, V; Martin-Polo, L; Martino, J; Martin-Porqueras, F; Mateos, I; McNamara, P W; Mendes, J; Mendes, L; Moroni, A; Nofrarias, M; Paczkowski, S; Perreur-Lloyd, M; Petiteau, A; Pivato, P; Plagnol, E; Prat, P; Ragnit, U; Ramos-Castro, J; Reiche, J; Romera Perez, J A; Robertson, D I; Rozemeijer, H; Rivas, F; Russano, G; Sarra, P; Schleicher, A; Slutsky, J; Sopuerta, C; Sumner, T J; Texier, D; Thorpe, J I; Trenkel, C; Vetrugno, D; Vitale, S; Wanner, G; Ward, H; Wass, P J; Wealthy, D; Weber, W J; Wittchen, A; Zanoni, C; Ziegler, T; Zweifel, P

    2017-04-28

    We report on electrostatic measurements made on board the European Space Agency mission LISA Pathfinder. Detailed measurements of the charge-induced electrostatic forces exerted on free-falling test masses (TMs) inside the capacitive gravitational reference sensor are the first made in a relevant environment for a space-based gravitational wave detector. Employing a combination of charge control and electric-field compensation, we show that the level of charge-induced acceleration noise on a single TM can be maintained at a level close to 1.0  fm s^{-2} Hz^{-1/2} across the 0.1-100 mHz frequency band that is crucial to an observatory such as the Laser Interferometer Space Antenna (LISA). Using dedicated measurements that detect these effects in the differential acceleration between the two test masses, we resolve the stochastic nature of the TM charge buildup due to interplanetary cosmic rays and the TM charge-to-force coupling through stray electric fields in the sensor. All our measurements are in good agreement with predictions based on a relatively simple electrostatic model of the LISA Pathfinder instrument.

  19. Model Test of Anchoring Effect on Zonal Disintegration in Deep Surrounding Rock Masses

    PubMed Central

    Chen, Xu-Guang; Zhang, Qiang-Yong; Wang, Yuan; Liu, De-Jun; Zhang, Ning

    2013-01-01

    The deep rock masses show a different mechanical behavior compared with the shallow rock masses. They are classified into alternating fractured and intact zones during the excavation, which is known as zonal disintegration. Such phenomenon is a great disaster and will induce the different excavation and anchoring methodology. In this study, a 3D geomechanics model test was conducted to research the anchoring effect of zonal disintegration. The model was constructed with anchoring in a half and nonanchoring in the other half, to compare with each other. The optical extensometer and optical sensor were adopted to measure the displacement and strain changing law in the model test. The displacement laws of the deep surrounding rocks were obtained and found to be nonmonotonic versus the distance to the periphery. Zonal disintegration occurs in the area without anchoring and did not occur in the model under anchoring condition. By contrasting the phenomenon, the anchor effect of restraining zonal disintegration was revealed. And the formation condition of zonal disintegration was decided. In the procedure of tunnel excavation, the anchor strain was found to be alternation in tension and compression. It indicates that anchor will show the nonmonotonic law during suppressing the zonal disintegration. PMID:23997683

  20. LISA Pathfinder test-mass charging during galactic cosmic-ray flux short-term variations

    NASA Astrophysics Data System (ADS)

    Grimani, C.; Fabi, M.; Lobo, A.; Mateos, I.; Telloni, D.

    2015-02-01

    Metal free-floating test masses aboard the future interferometers devoted to gravitational wave detection in space are charged by galactic and solar cosmic rays with energies \\gt 100 MeV/n. This process represents one of the main sources of noise in the lowest frequency band (\\lt 10-3 Hz) of these experiments. We study here the charging of the LISA Pathfinder (LISA-PF) gold-platinum test masses due to galactic cosmic-ray (GCR) protons and helium nuclei with the Fluka Monte Carlo toolkit. Projections of the energy spectra of GCRs during the LISA-PF operations in 2015 are considered. This work was carried out on the basis of the solar activity level and solar polarity epoch expected for LISA-PF. The effects of GCR short-term variations are evaluated here for the first time. Classical Forbush decreases, GCR variations induced by the Sun rotation, and fluctuations in the LISA-PF frequency bandwidth are discussed.

  1. Interpolation of the magnetic field at the test masses in eLISA

    NASA Astrophysics Data System (ADS)

    Mateos, I.; Díaz-Aguiló, M.; Ramos-Castro, J.; García-Berro, E.; Lobo, A.

    2015-08-01

    A feasible design for a magnetic diagnostics subsystem for eLISA will be based on that of its precursor mission, LISA Pathfinder. Previous experience indicates that magnetic field estimation at the positions of the test masses has certain complications. This is due to two reasons. The first is that magnetometers usually back-act due to their measurement principles (i.e., they also create their own magnetic fields), while the second is that the sensors selected for LISA Pathfinder have a large size, which conflicts with space resolution and with the possibility of having a sufficient number of them to properly map the magnetic field around the test masses. However, high-sensitivity and small-sized sensors that significantly mitigate the two aforementioned limitations exist, and have been proposed to overcome these problems. Thus, these sensors will be likely selected for the magnetic diagnostics subsystem of eLISA. Here we perform a quantitative analysis of the new magnetic subsystem, as it is currently conceived, and assess the feasibility of selecting these sensors in the final configuration of the magnetic diagnostic subsystem.

  2. Some Properties of a Bayesian Adaptive Ability Testing Strategy.

    ERIC Educational Resources Information Center

    McBride, James R.; Weiss, David J.

    Four monte carlo simulation studies of Owen's Bayesian sequential procedure for adaptive mental testing were conducted. Whereas previous simulation studies of this procedure have concentrated on evaluating it in terms of the correlation of its test scores with simulated ability in a normal population, these four studies explored a number of…

  3. Optimal Partitioning of Testing Time: Theoretical Properties and Practical Implications

    ERIC Educational Resources Information Center

    Wang, Tianyou; Zhang, Jiawei

    2006-01-01

    This paper deals with optimal partitioning of limited testing time in order to achieve maximum total test score. Nonlinear optimization theory was used to analyze this problem. A general case using a generic item response model is first presented. A special case that applies a response time model proposed by Wang and Hanson (2005) is also…

  4. Bacteria Buster: Testing Antibiotic Properties of Silver Nanoparticles

    ERIC Educational Resources Information Center

    Gardner, Grant E.; Jones, M. Gail

    2009-01-01

    Nanoscale science and engineering are disciplines that examine the unique behaviors and properties of materials that emerge at the size range of 1 to 100 nanometers (a billionth of a meter). Nanobiotechnology is a sub-discipline of nanoscience that has arisen more recently. Nanobiotechnology is already impacting the fields of healthcare and…

  5. Bacteria Buster: Testing Antibiotic Properties of Silver Nanoparticles

    ERIC Educational Resources Information Center

    Gardner, Grant E.; Jones, M. Gail

    2009-01-01

    Nanoscale science and engineering are disciplines that examine the unique behaviors and properties of materials that emerge at the size range of 1 to 100 nanometers (a billionth of a meter). Nanobiotechnology is a sub-discipline of nanoscience that has arisen more recently. Nanobiotechnology is already impacting the fields of healthcare and…

  6. Color film spectral properties test experiment for target simulation

    NASA Astrophysics Data System (ADS)

    Liu, Xinyue; Ming, Xing; Fan, Da; Guo, Wenji

    2017-04-01

    In hardware-in-loop test of the aviation spectra camera, the liquid crystal light valve and digital micro-mirror device could not simulate the spectrum characteristics of the landmark. A test system frame was provided based on the color film for testing the spectra camera; and the spectrum characteristics of the color film was test in the paper. The result of the experiment shows that difference was existed between the landmark and the film spectrum curse. However, the spectrum curse peak should change according to the color, and the curse is similar with the standard color traps. So, if the quantity value of error between the landmark and the film was calibrated and the error could be compensated, the film could be utilized in the hardware-in-loop test for the aviation spectra camera.

  7. Reflectivity properties of graphene with a nonzero mass-gap parameter

    NASA Astrophysics Data System (ADS)

    Klimchitskaya, G. L.; Mostepanenko, V. M.

    2016-05-01

    The reflectivity properties of graphene with a nonzero mass-gap parameter are investigated in the framework of a Dirac model using the polarization tensor in (2 +1 ) -dimensional space-time. For this purpose, a more simple explicit representation for the polarization tensor along the real frequency axis is found. The approximate analytic expressions for the polarization tensor and for the reflectivities of graphene are obtained in different frequency regions at any temperature. We show that the nonzero mass-gap parameter has a profound effect on the reflectivity of graphene. Specifically, at zero temperature the reflectivity of gapped graphene goes to zero with vanishing frequency. At nonzero temperature the same reflectivities are equal to unity at zero frequency. We also find the resonance behavior of the reflectivities of gapped graphene at both zero and nonzero temperature at the border frequency determined by the width of the gap. At nonzero temperature the reflectivities of graphene drop to zero in the vicinity of some frequency smaller than the border frequency. Our analytic results are accompanied with numerical computations performed over a wide frequency region. The developed formalism can be used in devising nanoscale optical detectors and optoelectronic switches and in other optical applications of graphene.

  8. Galaxy and mass assembly (GAMA): Mid-infrared properties and empirical relations from WISE

    SciTech Connect

    Cluver, M. E.; Jarrett, T. H.; Hopkins, A. M.; Gunawardhana, M. L. P.; Bauer, A. E.; Lara-López, M. A.; Driver, S. P.; Robotham, A. S. G.; Liske, J.; Taylor, E. N.; Alpaslan, M.; Baldry, I.; Brown, M. J. I.; Peacock, J. A.; Popescu, C. C.; Tuffs, R. J.; Bland-Hawthorn, J.; Colless, M.; Holwerda, B. W.; Leschinski, K.; and others

    2014-02-20

    The Galaxy And Mass Assembly (GAMA) survey furnishes a deep redshift catalog that, when combined with the Wide-field Infrared Survey Explorer (WISE), allows us to explore for the first time the mid-infrared properties of >110, 000 galaxies over 120 deg{sup 2} to z ≅ 0.5. In this paper we detail the procedure for producing the matched GAMA-WISE catalog for the G12 and G15 fields, in particular characterizing and measuring resolved sources; the complete catalogs for all three GAMA equatorial fields will be made available through the GAMA public releases. The wealth of multiwavelength photometry and optical spectroscopy allows us to explore empirical relations between optically determined stellar mass (derived from synthetic stellar population models) and 3.4 μm and 4.6 μm WISE measurements. Similarly dust-corrected Hα-derived star formation rates can be compared to 12 μm and 22 μm luminosities to quantify correlations that can be applied to large samples to z < 0.5. To illustrate the applications of these relations, we use the 12 μm star formation prescription to investigate the behavior of specific star formation within the GAMA-WISE sample and underscore the ability of WISE to detect star-forming systems at z ∼ 0.5. Within galaxy groups (determined by a sophisticated friends-of-friends scheme), results suggest that galaxies with a neighbor within 100 h {sup –1} kpc have, on average, lower specific star formation rates than typical GAMA galaxies with the same stellar mass.

  9. The impact of air mass advection on aerosol optical properties over Gotland (Baltic Sea)

    NASA Astrophysics Data System (ADS)

    Zdun, Agnieszka; Rozwadowska, Anna; Kratzer, Susanne

    2016-12-01

    In the present paper, measurements of aerosol optical properties from the Gotland station of the AERONET network, combined with a two-stage cluster analysis of back trajectories of air masses moving over Gotland, were used to identify the main paths of air mass advection to the Baltic Sea and to relate them to aerosol optical properties, i.e. the aerosol optical thickness at the wavelength λ = 500 nm, AOT (500) and the Ångström exponent for the spectral range from 440 to 870 nm, α(440,870). One- to six-day long back trajectories ending at 300, 500 and 3000 m above the station were computed using the HYSPLIT model. The study shows that in the Gotland region, variability in aerosol optical thickness AOT(500) is more strongly related to advections in the boundary layer than to those in the free troposphere. The observed variability in AOT(500) was best explained by the advection speeds and directions given by clustering of 4-day backward trajectories of air arriving in the boundary layer at 500 m above the station. 17 clusters of 4-day trajectories arriving at altitude 500 m above the Gotland station (sea level) derived using two-stage cluster analysis differ from each other with respect to trajectory length, the speed of air mass movement and the direction of advection. They also show different cluster means of AOT(500) and α(440,870). The cluster mean AOT(500) ranges from 0.342 ± 0.012 for the continental clusters M2 (east-southeast advection with moderate speed) and 0.294 ± 0.025 for S5 (slow south-southeast advection) to 0.064 ± 0.002 and 0.069 ± 0.002 for the respective marine clusters L3 (fast west-northwest advection) and M3 (north-northwest advection with moderate speed). The cluster mean α(440,870) varies from 1.65-1.70 for the short-trajectory clusters to 0.98 ± 0.03 and 1.06 ± 0.03 for the Arctic marine cluster L4 (fast inflow from the north) and marine cluster L5 (fast inflow from the west) respectively.

  10. DEFLECTIONS OF FAST CORONAL MASS EJECTIONS AND THE PROPERTIES OF ASSOCIATED SOLAR ENERGETIC PARTICLE EVENTS

    SciTech Connect

    Kahler, S. W.; Akiyama, S.; Gopalswamy, N.

    2012-08-01

    The onset times and peak intensities of solar energetic particle (SEP) events at Earth have long been thought to be influenced by the open magnetic fields of coronal holes (CHs). The original idea was that a CH lying between the solar SEP source region and the magnetic footpoint of the 1 AU observer would result in a delay in onset and/or a decrease in the peak intensity of that SEP event. Recently, Gopalswamy et al. showed that CHs near coronal mass ejection (CME) source regions can deflect fast CMEs from their expected trajectories in space, explaining the appearance of driverless shocks at 1 AU from CMEs ejected near solar central meridian (CM). This suggests that SEP events originating in CME-driven shocks may show variations attributable to CH deflections of the CME trajectories. Here, we use a CH magnetic force parameter to examine possible effects of CHs on the timing and intensities of 41 observed gradual E {approx} 20 MeV SEP events with CME source regions within 20 Degree-Sign of CM. We find no systematic CH effects on SEP event intensity profiles. Furthermore, we find no correlation between the CME leading-edge measured position angles and SEP event properties, suggesting that the widths of CME-driven shock sources of the SEPs are much larger than the CMEs. Independently of the SEP event properties, we do find evidence for significant CME deflections by CH fields in these events.

  11. Deflections of Fast Coronal Mass Ejections and the Properties of Associated Solar Energetic Particle Events

    NASA Technical Reports Server (NTRS)

    Kahler, S. W.; Akiyama, S.; Gopalswamy, N.

    2012-01-01

    The onset times and peak intensities of solar energetic particle (SEP) events at Earth have long been thought to be influenced by the open magnetic fields of coronal holes (CHs). The original idea was that a CH lying between the solar SEP source region and the magnetic footpoint of the 1 AU observer would result in a delay in onset and/or a decrease in the peak intensity of that SEP event. Recently, Gopalswamy et al. showed that CHs near coronal mass ejection (CME) source regions can deflect fast CMEs from their expected trajectories in space, explaining the appearance of driverless shocks at 1 AU from CMEs ejected near solar central meridian (CM). This suggests that SEP events originating in CME-driven shocks may show variations attributable to CH deflections of the CME trajectories. Here, we use a CH magnetic force parameter to examine possible effects of CHs on the timing and intensities of 41 observed gradual E approx 20 MeV SEP events with CME source regions within 20 deg. of CM. We find no systematic CH effects on SEP event intensity profiles. Furthermore, we find no correlation between the CME leading-edge measured position angles and SEP event properties, suggesting that the widths of CME-driven shock sources of the SEPs are much larger than the CMEs. Independently of the SEP event properties, we do find evidence for significant CME deflections by CH fields in these events

  12. Dynamics, kinetics, and transport properties of the one-dimensional mass-disordered harmonic lattice.

    PubMed

    Likhachev, Vladimir N; Vinogradov, George A; Astakhova, Tatyana Yu; Yakovenko, Andrey E

    2006-01-01

    In the present paper we thoroughly investigated the dynamics, kinetics, and the transport properties of the one-dimensional (1D) mass-disordered lattice of harmonic oscillators with the number of particles N < or =5000. The thermostat is simulated by the Langevin sources. Our method is adequate to any 1D lattice with linear equations of motion. Two accurate methods to calculate the temporal behavior of pair correlation functions were developed. The feature of the considered disordered model is an existence of localized states with great relaxation times tau to their stationary states. The exponential growth tau proportional variant exp(N) is observed. A method which allows us to extend the range of computed relaxation times up to tau approximately =(10)300 is suggested. The stationary state is unique. The thermal conduction x has the nonmonotonic character versus N: for the number of particles N < 300 the thermal conduction increases as x proportional variant ln N and reaches the maximal value at N approximately =300. At larger values the decreasing asymptotic is observed: x proportional variant N -alpha, and alpha approximately 0.27. An influence of parameters on the calculated properties was analyzed. Mathematical problems associated with the computation of very large times of establishing the stationary states were extensively studied.

  13. Anxiolytic effects of short- and long-term administration of cacao mass on rat elevated T-maze test.

    PubMed

    Yamada, Takashi; Yamada, Yasushi; Okano, Yasuyo; Terashima, Takehiko; Yokogoshi, Hidehiko

    2009-12-01

    We demonstrated the effects of short- and long-term administration of cacao mass on anxiety in the elevated T-maze test, which is an animal model of anxiety. In the first study, we administered cacao mass (100 mg/100 g body weight) per os and immediately performed the elevated T-maze test. Short-term cacao mass significantly abolished delayed avoidance latency compared with the control but did not change escape latency. This result suggested that cacao mass administration reduced conditional fear-relating behavior. Short-term cacao mass administration did not affect the concentration of brain monoamines, emotion-related neurotransmitters such as norepinephrine, serotonin and dopamine, in the rat brain. In the next study, we fed a cacao mass-containing diet to rats for 2 weeks and performed the elevated T-maze test. Contrary to short-term administration, chronic consumption of cacao mass tended to increase avoidance latency and did not change escape latency. Brain serotonin concentration and its turnover were enhanced by chronic consumption of cacao mass. These results suggested that chronic consumption of cacao did not affect fear-related behavior but was involved in brain monoamine metabolism. In conclusion, we suggest that short-term cacao mass consumption showed an anxiolytic effect but chronic consumption did not.

  14. How to report and interpret screening test properties: guidelines for driving researchers.

    PubMed

    Weaver, Bruce; Walter, Stephen D; Bédard, Michel

    2014-01-01

    One important goal of driving research is the development of a short but valid office-based screening test for fitness to drive of aging drivers. Several candidate tests have been proposed already, and no doubt others will be proposed in the future. It might seem obvious that authors advocating for the adoption of a particular screening test or procedure should report sensitivity, specificity, and other common screening test properties. Unfortunately, driving researchers have frequently failed to report any screening test properties. Others have reported screening test properties but have made basic mistakes such as calculating predictive values of positive and negative tests but reporting them incorrectly as sensitivity and specificity. These omissions and errors suggest that some driving researchers may be unaware of the importance of accurately reporting test properties when proposing a screening procedure and that others may need a refresher on how to calculate and interpret the most common screening test properties. Many good learning resources for screening and diagnostic tests are available, but most of them are intended for students and researchers in medicine, epidemiology, or public health. We hope that this tutorial in a prominent transportation journal will help lead to improved reporting and interpretation of screening test properties in articles that assess the usefulness of potential screening tools for fitness to drive.

  15. Mass physical properties of muddy intertidal sediments: some applications, misapplications and non-applications

    NASA Astrophysics Data System (ADS)

    Flemming, B. W.; Delafontaine, M. T.

    2000-07-01

    Mass physical properties of sediments are increasingly receiving attention outside the traditional fields of soil mechanics, geotechnical engineering and engineering geology because they are being recognised as important physical process-response parameters in sediment dynamics, benthic ecology, microbiology and biogeochemistry. In this study systematic relationships between bulk density, water content and sediment composition are presented for a variety of geographic environments. In all cases high correlations between these parameters are observed, all regions showing characteristic trends reflecting local environmental conditions. In this context, absolute water content is shown to be a universal master variable by means of which differences between individual environments can be normalised. It is postulated that relationships between water content and any other sediment parameter can be established by generating calibrations validated by carefully selected data bases which cover local ranges of sediment composition. Such site-specific calibrations can be used in regional and inter-regional modelling exercises. Thus, a universal negative relationship between absolute water content ( Wa) and dry bulk density (BD d) of common terrigenous material is expressed by the equation BD d =2.6596369 - 0.0886164 Wa+0.0088041 W1.5a - 0.0002594 W2a ( r=-0.9991, n=112). An extensive literature survey reveals that the term "concentration", which refers to a mass per unit volume, is frequently confused with the term "content" which refers to a mass per unit mass. It is demonstrated that this widespread malpractice has been responsible for serious misinterpretations of otherwise perfectly good data because quantitative comparisons are being made between parameters having different physical dimensions. In other cases, it has prevented the recognition of well-correlated relationships, resulting in incomplete arguments or unfounded speculations. In view of this, we advocate a

  16. Structural mass irregularities and fiber volume influence on morphology and mechanical properties of unsaturated polyester resin in matrix composites

    PubMed Central

    Ahmed, Khalil; Nasir, Muhammad; Fatima, Nasreen; Khan, Khalid M.; Zahra, Durey N.

    2014-01-01

    This paper presents the comparative results of a current study on unsaturated polyester resin (UPR) matrix composites processed by filament winding method, with cotton spun yarn of different mass irregularities and two different volume fractions. Physical and mechanical properties were measured, namely ultimate stress, stiffness, elongation%. The mechanical properties of the composites increased significantly with the increase in the fiber volume fraction in agreement with the Counto model. Mass irregularities in the yarn structure were quantitatively measured and visualized by scanning electron microscopy (SEM). Mass irregularities cause marked decrease in relative strength about 25% and 33% which increases with fiber volume fraction. Ultimate stress and stiffness increases with fiber volume fraction and is always higher for yarn with less mass irregularities. PMID:26644920

  17. Mechanical properties of dental Ti-Ag alloys with 22.5, 25, 27.5, and 30 mass% Ag.

    PubMed

    Takahashi, Masatoshi; Kikuchi, Masafumi; Takada, Yukyo

    2015-01-01

    The mechanical properties -tensile strength, yield strength, elongation after fracture, Vickers hardness, and Young's modulus-and the phases of Ti-Ag alloys were investigated, as prepared with 22.5, 25, 27.5, and 30 mass% Ag. The tensile strength, yield strength, hardness, and Young's modulus of the alloys increase with their Ag content up to 25 mass%, but their breaking elongation decreases. These changes in the mechanical properties are attributed to solid-solution strengthening of the α-titanium phase, to Ti2Ag precipitation, and to the formation of eutectic structures composed of α+Ti2Ag. The addition of Ag, at 25 mass% in particular, improves the mechanical properties of these alloys, making them suitable for high strength dental prostheses, such as implantretained superstructures and narrow-diameter implants.

  18. Psychometric properties of the benton visual form discrimination test.

    PubMed

    Lopez, Michael N; Charter, Richard A; Oh, Sindy; Lazar, Michael D; Imperio, Shellah M

    2005-01-01

    Coefficient alpha and an item analysis were calculated for the 16-item Benton Visual Form Discrimination Test (VFDT) using a heterogeneous sample (N = 293) of mostly elderly medical patients who were suspected of having cognitive impairment. The total score reliability was .74. An item analysis found that 15 of the items were within established criteria for item difficulty, however, 5 items were found to be poor discriminators. Through the use of confidence intervals around observed scores, it was shown that the current classification criterion for the VFDT demands a higher reliability coefficient than what was found. Also, evidence for the test's insufficient level of difficulty is presented. It is difficult to recommend this test for clinical use.

  19. Psychometric Properties of the Practical Skills Test (PST)

    PubMed Central

    Helfrich, Christine A.; Coster, Wendy J.

    2013-01-01

    The Practical Skills Test (PST) is a new assessment of individuals’ knowledge of life skills. We evaluated the PST’s reliability, validity, and sensitivity to change among a homeless population. Participants were 123 homeless persons in a longitudinal experimental study who were assessed before and after intervention with the PST, Allen Cognitive Level Screen–2000 (ACLS–2000), and Impact of Event Scale–Revised (IES–R). The PST showed generally good internal consistency, no floor effects, and limited ceiling effects (<20% on each test). Supportive evidence for the PST’s convergent validity was seen in its moderate correlations with the ACLS–2000; we found no significant correlation with the IES–R. Paired t tests indicated that the PST is sensitive to changes in life skills after intervention, but effect sizes were small. The results suggest that the PST has generally good reliability and validity. However, ceiling effects suggest an area for further development. PMID:23433280

  20. Self-testing properties of Gisin's elegant Bell inequality

    NASA Astrophysics Data System (ADS)

    Andersson, Ole; Badzi&aogo; g, Piotr; Bengtsson, Ingemar; Dumitru, Irina; Cabello, Adán

    2017-09-01

    An experiment in which the Clauser-Horne-Shimony-Holt inequality is maximally violated is self-testing (i.e., it certifies in a device-independent way both the state and the measurements). We prove that an experiment maximally violating Gisin's elegant Bell inequality is not similarly self-testing. The reason can be traced back to the problem of distinguishing an operator from its complex conjugate. We provide a complete and explicit characterization of all scenarios in which the elegant Bell inequality is maximally violated. This enables us to see exactly how the problem plays out.

  1. Testing Fundamental Properties of Space with the Fermilab Holometer

    NASA Astrophysics Data System (ADS)

    Kamai, Brittany

    2017-05-01

    Precision length measurements provide valuable insights about the fundamental properties of space-time. The Holometer is a research program to both experimentally probe signatures of the Planck scale and to extend the accessible frequency range from kHz up to MHz for gravitational wave searches. The instrument consists of separate yet identical 39-meter Michelson interferometers operated at Fermi National Accelerator Laboratory, which can reach length sensitivities better than {10}-20{m/}\\sqrt{{Hz}} within the 1-10 MHz frequency range. The Holometer is fully operational with 130 of hours of science quality data obtained during the first observational campaign.

  2. A unified theory of impact crises and mass extinctions: quantitative tests.

    PubMed

    Rampino, M R; Haggerty, B M; Pagano, T C

    1997-05-30

    Several quantitative tests of a general hypothesis linking impacts of large asteroids and comets with mass extinctions of life are possible based on astronomical data, impact dynamics, and geological information. The waiting times of large-body impacts on the Earth derived from the flux of Earth-crossing asteroids and comets, and the estimated size of impacts capable of causing, large-scale environmental disasters, predict the impacts of objects > or = 5 km in diameter (> or = 10(7) Mt TNT equivalent) could be sufficient to explain the record of approximately 25 extinction pulses in the last 540 Myr, with the 5 recorded major mass extinctions related to impacts of the largest objects of > or = 10 km in diameter (> or = 10(8) Mt events). Smaller impacts (approximately 10(6) Mt), with significant regional environmental effects, could be responsible for the lesser boundaries in the geologic record. Tests of the "kill curve" relationship for impact-induced extinctions based on new data on extinction intensities, and several well-dated large impact craters, also suggest that major mass extinctions require large impacts, and that a step in the kill curve may exist at impacts that produce craters of approximately 100 km diameter, smaller impacts being capable of only relatively weak extinction pulses. Single impact craters less than approximately 60 km in diameter should not be associated with detectable global extinction pulses (although they may explain stage and zone boundaries marked by lesser faunal turnover), but multiple impacts in that size range may produce significant stepped extinction pulses. Statistical tests of the last occurrences of species at mass-extinction boundaries are generally consistent with predictions for abrupt or stepped extinctions, and several boundaries are known to show "catastrophic" signatures of environmental disasters and biomass crash, impoverished postextinction fauna and flora dominated by stress-tolerant and opportunistic species

  3. Carbon isotope ratio mass spectrometry for detection of endogenous steroid use: a testing strategy.

    PubMed

    Ahrens, Brian D; Butch, Anthony W

    2013-07-01

    Isotope ratio mass spectrometry (IRMS) testing is performed to determine if an atypical steroid profile is due to administration of an endogenous steroid. Androsterone (Andro) and etiocholanolone (Etio), and/or the androstanediols (5α- and 5β-androstane-3α,17β-diol) are typically analyzed by IRMS to determine the (13) C/(12) C ratio. The ratios of these target compounds are compared to the (13) C/(12) C ratio of an endogenous reference compound (ERC) such as 5β-pregnane-3α,20α-diol (Pdiol). Concentrations of Andro and Etio are high so (13) C/(12) C ratios can easily be measured in most urine samples. Despite the potentially improved sensitivity of the androstanediols for detecting the use of some testosterone formulations, additional processing steps are often required that increase labour costs and turnaround times. Since this can be problematic when performing large numbers of IRMS measurements, we established thresholds for Andro and Etio that can be used to determine the need for additional androstanediol testing. Using these criteria, 105 out of 2639 urine samples exceeded the Andro and/or Etio thresholds, with 52 of these samples being positive based on Andro and Etio IRMS testing alone. The remaining 53 urine samples had androstanediol IRMS testing performed and 3 samples were positive based on the androstanediol results. A similar strategy was used to establish a threshold for Pdiol to identify athletes with relatively (13) C-depleted values so that an alternative ERC can be used to confirm or establish a true endogenous reference value. Adoption of a similar strategy by other laboratories can significantly reduce IRMS sample processing and analysis times, thereby increasing testing capacity.

  4. Design, fabrication and test of a microfluidic nebulizer chip for desorption electrospray ionization mass spectrometry

    PubMed Central

    Sen, A K; Darabi, J; Knapp, D R

    2009-01-01

    This paper presents design, microfabrication, and test of a microfluidic nebulizer chip for desorption electrospray ionization mass spectrometry (DESI-MS) in proteomic analysis. The microfluidic chip is fabricated using cyclic olefin copolymer (COC) substrates. The fluidic channels are thermally embossed onto a base substrate using a nickel master and then a top substrate is thermally bonded to seal the channels. Carbon ink embossed into the top COC substrate is used to established electrical connection between the external power supply and the liquid in the channel. The microfluidic chip to external capillary connection is fabricated using Nanoport™ interconnection system. Preliminary leakage test was performed to demonstrate the interconnection system is leak-free and pressure test was performed to evaluate the burst pressure. Finally, the nebulizer chip was used to perform DESI-MS for analyzing peptides (BSA and bradykinin) and reserpine on the nanoporous alumina surface. DESI-MS performance of the microfluidic nebulizer chip is compared with that obtained using a conventional DESI nebulizer. PMID:20161284

  5. Prediction of Lateral Ankle Sprains in Football Players Based on Clinical Tests and Body Mass Index.

    PubMed

    Gribble, Phillip A; Terada, Masafumi; Beard, Megan Q; Kosik, Kyle B; Lepley, Adam S; McCann, Ryan S; Pietrosimone, Brian G; Thomas, Abbey C

    2016-02-01

    The lateral ankle sprain (LAS) is the most common injury suffered in sports, especially in football. While suggested in some studies, a predictive role of clinical tests for LAS has not been established. To determine which clinical tests, focused on potentially modifiable factors of movement patterns and body mass index (BMI), could best demonstrate risk of LAS among high school and collegiate football players. Case-control study; Level of evidence, 3. A total of 539 high school and collegiate football players were evaluated during the preseason with the Star Excursion Balance Test (SEBT) and Functional Movement Screen as well as BMI. Results were compared between players who did and did not suffer an LAS during the season. Logistic regression analyses and calculated odds ratios were used to determine which measures predicted risk of LAS. The LAS group performed worse on the SEBT-anterior reaching direction (SEBT-ANT) and had higher BMI as compared with the noninjured group (P < .001). The strongest prediction models corresponded with the SEBT-ANT. Low performance on the SEBT-ANT predicted a risk of LAS in football players. BMI was also significantly higher in football players who sustained an LAS. Identifying clinical tools for successful LAS injury risk prediction will be a critical step toward the creation of effective prevention programs to reduce risk of sustaining an LAS during participation in football. © 2015 The Author(s).

  6. A Unified Theory of Impact Crises and Mass Extinctions: Quantitative Tests

    NASA Technical Reports Server (NTRS)

    Rampino, Michael R.; Haggerty, Bruce M.; Pagano, Thomas C.

    1997-01-01

    Several quantitative tests of a general hypothesis linking impacts of large asteroids and comets with mass extinctions of life are possible based on astronomical data, impact dynamics, and geological information. The waiting of large-body impacts on the Earth derive from the flux of Earth-crossing asteroids and comets, and the estimated size of impacts capable of causing large-scale environmental disasters, predict that impacts of objects greater than or equal to 5 km in diameter (greater than or equal to 10 (exp 7) Mt TNT equivalent) could be sufficient to explain the record of approximately 25 extinction pulses in the last 540 Myr, with the 5 recorded major mass extinctions related to impacts of the largest objects of greater than or equal to 10 km in diameter (greater than or equal to 10(exp 8) Mt Events). Smaller impacts (approximately 10 (exp 6) Mt), with significant regional environmental effects, could be responsible for the lesser boundaries in the geologic record.

  7. A Unified Theory of Impact Crises and Mass Extinctions: Quantitative Tests

    NASA Technical Reports Server (NTRS)

    Rampino, Michael R.; Haggerty, Bruce M.; Pagano, Thomas C.

    1997-01-01

    Several quantitative tests of a general hypothesis linking impacts of large asteroids and comets with mass extinctions of life are possible based on astronomical data, impact dynamics, and geological information. The waiting of large-body impacts on the Earth derive from the flux of Earth-crossing asteroids and comets, and the estimated size of impacts capable of causing large-scale environmental disasters, predict that impacts of objects greater than or equal to 5 km in diameter (greater than or equal to 10 (exp 7) Mt TNT equivalent) could be sufficient to explain the record of approximately 25 extinction pulses in the last 540 Myr, with the 5 recorded major mass extinctions related to impacts of the largest objects of greater than or equal to 10 km in diameter (greater than or equal to 10(exp 8) Mt Events). Smaller impacts (approximately 10 (exp 6) Mt), with significant regional environmental effects, could be responsible for the lesser boundaries in the geologic record.

  8. Experimental test of the mass dependence of the heuristic drift model

    NASA Astrophysics Data System (ADS)

    Makowski, M. A.; Osborne, T. H.; Leonard, A. W.; Bortolon, A.; Nazikian, R.

    2016-10-01

    An empirical scaling for the heat flux scrape-off-layer (SOL) width has been developed, but the physics setting the heat flux width has yet to be established. However, a heuristic model for the width scaling has been developed which is consistent with currently available data. Recent experiments in helium discharges and in which the pedestal and SOL had > 75 % impurity (He, Li, C, N, or Ne) content, provide a means of testing the mass scaling of the heuristic model. Preliminary results indicate either no or a weakly negative scaling of the measured heat flux width with mass. This result lies between the predicted approximate √{ A / Z } (electron drift dominated) and √{ A /Z3 } (ion drift dominated) dependencies predicted by the model, indicating a complicated interplay between the electrons and multiple ion species present in the SOL. These and other results related to the heuristic model will be presented. Supported by US DOE under DE AC52 07NA27344, DE-FC02-04ER54698, and DE-AC02-09CH11466.

  9. Testing mixed action approaches to meson spectroscopy with twisted mass sea quarks

    NASA Astrophysics Data System (ADS)

    Berlin, J.; Palao, D.; Wagner, M.

    We explore and compare three mixed action setups with Wilson twisted mass sea quarks and different valence quark actions: (1) Wilson twisted mass, (2) Wilson twisted mass + clover and (3) Wilson + clover. Our main goal is to reduce lattice discretization errors in mesonic spectral quantities, in particular to reduce twisted mass parity and isospin breaking.

  10. Automatic Rayleigh scattering mapping system for optical quality evaluation of test masses for gravity wave detectors

    NASA Astrophysics Data System (ADS)

    Yan, Zewu; Zhao, Chunnong; Ju, Li; Gras, Slawomir; Baringa, Pablo; Blair, David G.

    2005-01-01

    This article describes an automatic Rayleigh scattering mapping system (ARSMS), which enables quantitative high-resolution three-dimensional mapping of inhomogeneities in optical materials. The ARSMS allows large high-grade test mass samples for gravitational wave detectors to be evaluated to ensure that an adequate low level of scattering is achieved. The ARSMS combines proprietary camera software with data analysis software and control software to achieve fully automatic operation with graphical user interfaces. This article presents the instrument concept and examples of the output. Device mapping in all degrees of freedom is shown to be better than 0.5mm, with scattering sensitivity better than 0.5ppm/cm. This system is able to scan and map the Rayleigh scattering of large samples in both of cylindrical and rectangular samples using cylindrical and Cartesian coordinates.

  11. Kinematic properties of solar coronal mass ejections: Correction for projection effects in spacecraft coronagraph measurements

    NASA Astrophysics Data System (ADS)

    Howard, T. A.; Nandy, D.; Koepke, A. C.

    2008-01-01

    One of the main sources of uncertainty in quantifying the kinematic properties of coronal mass ejections (CMEs) using coronagraphs is the fact that coronagraph images are projected into the sky plane, resulting in measurements which can differ significantly from their actual values. By identifying solar surface source regions of CMEs using X-ray and Hα flare and disappearing filament data, and through considerations of CME trajectories in three-dimensional (3-D) geometry, we have devised a methodology to correct for the projection effect. We outline this method here. The methodology was automated and applied to over 10,000 CMEs in the Coordinated Data Analysis Workshop (CDAW) (SOHO Large Angle Spectroscopic Coronagraph) catalog spanning 1996-2005, in which we could associate 1961 CMEs with an appropriate surface event. In the latter subset, deprojected speeds, accelerations, and launch angles were determined to study CME kinematics. Our analysis of this subset of events reconfirms some important trends, notably that previously uncovered solar cycle variation of CME properties are preserved, CMEs with greater width have higher speeds, and slower CMEs tend to accelerate while faster CMEs tend to decelerate. This points out that statistical trends in CME properties, recovered from plane-of-sky measurements, may be preserved even in the face of more sophisticated 3-D measurements from spacecrafts such as STEREO, if CME trajectories are predominantly radial. However, our results also show that the magnitude of corrected measurements can differ significantly from the projected plane-of-sky measurements on a case-by-case basis and that acceleration is more sensitive to the deprojection process than speed. Average corrected speed and acceleration tend to be a factor of 1.7 and 4.4 higher than their projected values, with mean corrected speed and acceleration magnitudes being on the order of 1000 km/s and 50 m/s2, respectively. We conclude that while using the plane

  12. Measuring test mass acceleration noise in space-based gravitational wave astronomy

    NASA Astrophysics Data System (ADS)

    Congedo, Giuseppe

    2015-03-01

    The basic constituent of interferometric gravitational wave detectors—the test-mass-to-test-mass interferometric link—behaves as a differential dynamometer measuring effective differential forces, comprising an integrated measure of gravity curvature, inertial effects, as well as nongravitational spurious forces. This last contribution is going to be characterized by the LISA Pathfinder mission, a technology precursor of future space-borne detectors like eLISA. Changing the perspective from displacement to acceleration can benefit the data analysis of LISA Pathfinder and future detectors. The response in differential acceleration to gravitational waves is derived for a space-based detector's interferometric link. The acceleration formalism can also be integrated into time delay interferometry by building up the unequal-arm Michelson differential acceleration combination. The differential acceleration is nominally insensitive to the system's free evolution dominating the slow displacement dynamics of low-frequency detectors. Working with acceleration also provides an effective way to subtract measured signals acting as systematics, including the actuation forces. Because of the strong similarity with the equations of motion, the optimal subtraction of systematic signals, known within some amplitude and time shift, with the focus on measuring the noise provides an effective way to solve the problem and marginalize over nuisance parameters. The F statistic, in widespread use throughout the gravitation waves community, is included in the method and suitably generalized to marginalize over linear parameters and noise at the same time. The method is applied to LPF simulator data and, thanks to its generality, can also be applied to the data reduction and analysis of future gravitational wave detectors.

  13. Tensile mechanical properties tests of non-standard component in high temperature

    NASA Astrophysics Data System (ADS)

    Su, Wei; Liu, Renhuai; Song, Fangfang; Zhu, Junhua

    2017-05-01

    This paper makes research on tensile mechanical properties tests of heater component in electron gun. Tests are studied to get tensile property of heater component at the room and elevated temperature. Though improving test clamping appliance and experimental methods, discussing tensile fracture analysis, rupture mechanism is obtained by in situ observation using scanning electron microscope (SEM). To facilitate engineering application, materials suggestion is given at the end of the paper.

  14. Thermal and mechanical analysis on the cold mass support assembly of test cryomodule for IMP ADS-injector-II

    NASA Astrophysics Data System (ADS)

    Guo, X. L.; Wang, L.; Wang, J.; Wang, S. Y.; Liu, Y. Y.; Sun, S.

    2014-01-01

    The Injector-II of ADS project will include two cryomodules, each of which consists of eight HWR cavities and nine SC solenoid magnets. A test cryomodule (TCM1) containing one HWR cavity and two SC magnets was developed for verification of related technique at the first stage. The TCM1 cryostat was designed by Shanghai Institute of Applied Physics of Chinese Academy of Sciences (SINAP, CAS). The cold mass support assembly in the test cryomodule should accommodate the unbalanced loads induced by each cold mass assembly, the deformation induced by thermal shrinkage, and the thermal stress between different materials. In order to validate the structure design, coupled thermal and mechanical analysis on the cold mass support assembly was performed. The temperature, deformation and stress of the cold mass support assembly were obtained. The results effectively provide the guideline for the design and improvement of the cold mass support assembly.

  15. Long-term monitoring of rock mass properties in the underground excavation

    NASA Astrophysics Data System (ADS)

    Vilhelm, Jan; Jirků, Jaroslav; Slavík, Lubomír; Bárta, Jaroslav

    2015-04-01

    It is generally agreed today that hazardous waste should be placed in repositories hundreds of meters below the Earth's surface. In our research we deal with the long-term monitoring of the underground excavation by seismic and electrical resistivity measurements. Permanent measuring system was developed and installed at the Bedřichov gallery test site (northern Bohemia). The gallery was excavated using TBM (Tunnel Boring Machine) in granitic rocks. Realized repeated measurements include ultrasonic time of flight measurement and electrical resistivity tomography (ERT). The seismic measurements are performed by pulse-transmission technique directly on the rock wall using one seismic source and three receivers in the distances of 1, 2 and 3 m. The main emphasis is devoted to P-waves; however, recording of full waveform enables analyzing of S- waves and other types of waves as well. The comparison of repeated measurements is used for an assessment of changes in seismic velocities with very high-accuracy. The repetition rate of measurements can be selected from seconds; however such fast changes in the rock mass are unexpected. The ERT measurement is performed on the same rock wall using 48 electrodes. The spacing between electrodes is 20 centimeters. The conductivity of undisturbed granitic rocks is extremely low. Therefore the observed local increase of conductivity can be associated with joints and fractures saturated with water, resulting in their ionic conductivity. Repeated ERT measurement can reveal some changes in the rock mass. Due to time requirements of ERT measurement the repetition rate can be about three hours. The data collected by measuring system is transferred by means of computer network and can be accessed via internet. This contribution deals with preliminary results gained so far during the testing of developed monitoring system. Acknowledgments: This work was partially supported by the Technology Agency of the Czech Republic, project No. TA

  16. Testing Theoretical Evolutionary Models with AB Doradus C and the Initial Mass Function

    NASA Astrophysics Data System (ADS)

    Luhman, K. L.; Potter, D.

    2006-02-01

    We assess the constraints on the evolutionary models of young low-mass objects that are provided by the measurements of the companion AB Dor C by Close and coworkers and by a new comparison of model-derived IMFs of star-forming regions to the well-calibrated IMF of the solar neighborhood. After performing an independent analysis of all of the imaging and spectroscopic data for AB Dor C that were obtained by Close, we find that AB Dor C (which has no methane) is not detected at a significant level (S/N~1.2) in the SDI data when one narrowband image is subtracted from another but that it does appear in the individual SDI frames, as well as the images at J, H, and Ks. Although our broadband photometry for AB Dor C is consistent with that of Close, the uncertainties that we measure are larger. Using the age of τ=75-150 Myr recently estimated for AB Dor by Luhman and coworkers, the luminosity predicted by the models of Chabrier and Baraffe is consistent with the value that we estimate from the photometry for AB Dor C. We measure a spectral type of M6+/-1 from the K-band spectrum of AB Dor C, which is earlier than the value of M8+/-1 reported by Close and is consistent with the model predictions when a dwarf temperature scale is adopted. In a test of these evolutionary models at much younger ages, we show that the low-mass IMFs that they produce for star-forming regions are similar to the IMF of the solar neighborhood. If the masses of the low-mass stars and brown dwarfs in these IMFs of star-forming regions were underestimated by a factor of 2 as suggested by Close, then the IMF characterizing the current generation of Galactic star formation would have to be radically different from the IMF of the solar neighborhood. Based on observations made with ESO telescopes at the Paranal Observatories under program ID 60.A-9026. This publication makes use of data products from the Two Micron All Sky Survey, which is a joint project of the University of Massachusetts and the

  17. Testing Thermal Properties of the Cooling Device with Heat Pipes

    NASA Astrophysics Data System (ADS)

    Nemec, P.; Čaja, A.; Malcho, M.

    2013-04-01

    Paper deal about testing of device with heat pipes and about research alternative possible applications of heat pipes and potential improvements in purpose effective heat sink from power switches of device. This device is used in various static and moveable applications. Testing device is part of control unit in rail vehicle. The amount of heat produced by power switches depend from working conditions of static converter. Great impact on heat sink has, how as season also this if the vehicle is moving or don't moving. If the vehicle is moving the heat transfer form energy converter to surrounding is caused by forced convection of air flow around device. But the critical conditions occur if the vehicle doesn't move, because the application of this cooling device is based on natural convection. The study deal solution of the problem heat transfer from energy converter to surrounding by natural convection.

  18. Laboratory test methods for combustion stability properties of solid propellants

    NASA Technical Reports Server (NTRS)

    Strand, L. D.; Brown, R. S.

    1992-01-01

    An overview is presented of experimental methods for determining the combustion-stability properties of solid propellants. The methods are generally based on either the temporal response to an initial disturbance or on external methods for generating the required oscillations. The size distribution of condensed-phase combustion products are characterized by means of the experimental approaches. The 'T-burner' approach is shown to assist in the derivation of pressure-coupled driving contributions and particle damping in solid-propellant rocket motors. Other techniques examined include the rotating-valve apparatus, the impedance tube, the modulated throat-acoustic damping burner, and the magnetic flowmeter. The paper shows that experimental methods do not exist for measuring the interactions between acoustic velocity oscillations and burning propellant.

  19. Testing Fundamental Properties of Space with the Fermilab Holometer

    DOE PAGES

    Kamai, Brittany

    2017-06-01

    Precision length measurements provide valuable insights about the fundamental properties of space-time. The Holometer is a research program to both experimentally probe signatures of the Planck scale and to extend the accessible frequency range from kHz up to MHz for gravitational wave searches. The instrument consists of separate yet identical 39-meter Michelson interferometers operated at Fermi National Accelerator Laboratory, which can reach length sensitivities better thanmore » $${10}^{-20}\\mathrm{m/}\\sqrt{\\mathrm{Hz}}$$ within the 1-10 MHz frequency range. Lastly, the Holometer is fully operational with 130 of hours of science quality data obtained during the first observational campaign.« less

  20. RESULTS OF CESIUM MASS TRANSFER TESTING FOR NEXT GENERATION SOLVENT WITH HANFORD WASTE SIMULANT AP-101

    SciTech Connect

    Peters, T.; Washington, A.; Fink, S.

    2011-09-27

    SRNL has performed an Extraction, Scrub, Strip (ESS) test using the next generation solvent and AP-101 Hanford Waste simulant. The results indicate that the next generation solvent (MG solvent) has adequate extraction behavior even in the face of a massive excess of potassium. The stripping results indicate poorer behavior, but this may be due to inadequate method detection limits. SRNL recommends further testing using hot tank waste or spiked simulant to provide for better detection limits. Furthermore, strong consideration should be given to performing an actual waste, or spiked waste demonstration using the 2cm contactor bank. The Savannah River Site currently utilizes a solvent extraction technology to selectively remove cesium from tank waste at the Multi-Component Solvent Extraction unit (MCU). This solvent consists of four components: the extractant - BoBCalixC6, a modifier - Cs-7B, a suppressor - trioctylamine, and a diluent, Isopar L{trademark}. This solvent has been used to successfully decontaminate over 2 million gallons of tank waste. However, recent work at Oak Ridge National Laboratory (ORNL), Argonne National Laboratory (ANL), and Savannah River National Laboratory (SRNL) has provided a basis to implement an improved solvent blend. This new solvent blend - referred to as Next Generation Solvent (NGS) - is similar to the current solvent, and also contains four components: the extractant - MAXCalix, a modifier - Cs-7B, a suppressor - LIX-79{trademark} guanidine, and a diluent, Isopar L{trademark}. Testing to date has shown that this 'Next Generation' solvent promises to provide far superior cesium removal efficiencies, and furthermore, is theorized to perform adequately even in waste with high potassium concentrations such that it could be used for processing Hanford wastes. SRNL has performed a cesium mass transfer test in to confirm this behavior, using a simulant designed to simulate Hanford AP-101 waste.

  1. Statistical properties of solar flares and coronal mass ejections through the solar cycle

    SciTech Connect

    Telloni, Daniele; Antonucci, Ester; Carbone, Vincenzo; Lepreti, Fabio

    2016-03-25

    Waiting Time Distributions (WTDs) of solar flares are investigated all through the solar cycle. The same approach applied to Coronal Mass Ejections (CMEs) in a previous work is considered here for flare occurrence. Our analysis reveals that flares and CMEs share some common statistical properties, which result dependent on the level of solar activity. Both flares and CMEs seem to independently occur during minimum solar activity phases, whilst their WTDs significantly deviate from a Poisson function at solar maximum, thus suggesting that these events are correlated. The characteristics of WTDs are constrained by the physical processes generating those eruptions associated with flares and CMEs. A scenario may be drawn in which different mechanisms are actively at work during different phases of the solar cycle. Stochastic processes, most likely related to random magnetic reconnections of the field lines, seem to play a key role during solar minimum periods. On the other hand, persistent processes, like sympathetic eruptions associated to the variability of the photospheric magnetism, are suggested to dominate during periods of high solar activity. Moreover, despite the similar statistical properties shown by flares and CMEs, as it was mentioned above, their WTDs appear different in some aspects. During solar minimum periods, the flare occurrence randomness seems to be more evident than for CMEs. Those persistent mechanisms generating interdependent events during maximum periods of solar activity can be suggested to play a more important role for CMEs than for flares, thus mitigating the competitive action of the random processes, which seem instead strong enough to weaken the correlations among flare event occurrence during solar minimum periods. However, it cannot be excluded that the physical processes at the basis of the origin of the temporal correlation between solar events are different for flares and CMEs, or that, more likely, more sophisticated effects are

  2. Effects of Role Demands and Test Cue Properties on Personality Test Performance: Replication and Extension

    ERIC Educational Resources Information Center

    Kroger, Rolf O.; Turnbull, William

    1970-01-01

    In a replication of earlier findings by Kroger, the hypothesis was tested that the situation affects test performance by generating a set of role demands. Community college students described themselves on the SVIB, Taylor Manifest Anxiety Scale, and Welsh Figure Preference Test after being exposed to implicit social cues intended to induce…

  3. Test Methods for Measuring Material Properties of Composite Materials in all Three Material Axes

    DTIC Science & Technology

    2012-01-24

    Elastic Properties Strength Properties ASTM Ref. In-Plane Tension Ex, Ey, νxy STx, STy D 3039 In-Plane Compression ECx, ECy, νCxy SCx, SCy D 6641 In...as required. The in-plane tension test was conducted using ASTM D 3039 /D 3039M “Standard Test Method for Tensile Properties of Polymer Composite...properties were determined for fiber-reinforced polymers (FRPs) with respect to all three material orientations using existing ASTM standards when

  4. Comparison of a stool antigen test and serology for the diagnosis of Helicobacter pylori infection in mass survey.

    PubMed

    Shimoyama, Tadashi; Oyama, Takao; Matsuzaka, Masashi; Danjo, Kazuma; Nakaji, Shigeyuki; Fukuda, Shinsaku

    2009-04-01

    Serum antibody to Helicobacter pylori is tested in mass screening for gastric cancer along with the level of serum pepsinogens (PG) I and II. Recently, stool antigen tests have been developed as a new non-invasive test. We examined H. pylori infection by both serology and stool antigen test in a mass survey and compared the results to estimate applicability of stool antigen test for mass survey. A total of 994 healthy adults who received mass survey in April 2005 were tested. There were 379 men and 615 women, and the mean age was 57.7 years old. Stool samples were used to measure a H. pylori-specific antigen by enzyme immunoassay. Serum samples were tested for the prevalence of IgG antibody to H. pylori, and the level of PGs I and II was also measured to determine the presence of atrophic gastritis. Infection of H. pylori was defined as positive 61.4% and 56.4% by serology and stool antigen test, respectively. The concordance of both tests was not affected by gender and age of the subjects but difference was seen in subjects with atrophic gastritis. In particular, positivity of stool antigen test (81.8%) was significantly lower than that of serology (88.7%, p < .05) in 303 subjects with severe atrophic gastritis. Stool antigen test, which detects present but not previous infection of H. pylori, would be applicable to diagnose H. pylori infection in mass survey. Usefulness of stool antigen tests for the screening of gastric cancer should be examined.

  5. Dynamic properties of municipal solid waste landfills from surface wave tests

    SciTech Connect

    Haker, C.D.; Rix, G.J.; Lai, C.G.

    1997-10-01

    The seismic stability of municipal solid waste (MSW) landfills is often a significant consideration in landfill design. However, until recently, the dynamic properties of the waste material itself, which govern the seismic response of MSW landfills, have often been approximated or assumed. Tests to determine the dynamic properties of the material directly have been limited. Measurements of seismic surface waves were used to determine the dynamic properties of MSW, which are the initial tangent shear modulus and low-strain hysteretic damping ratio. Surface wave tests were performed at three MSW landfills to determine their shear modulus and damping ratio profiles. Surface wave tests are ideal for measuring the near-surface shear modulus and damping profiles of MSW landfills because the tests are non-invasive, an advantage for testing environmentally sensitive waste material. Factors which influence the dynamic properties of waste including density, confinement, age, and placement techniques are used to interpret the measured shear modulus and damping ratio profiles.

  6. Plant diversity does not buffer drought effects on early-stage litter mass loss rates and microbial properties.

    PubMed

    Vogel, Anja; Eisenhauer, Nico; Weigelt, Alexandra; Scherer-Lorenzen, Michael

    2013-09-01

    Human activities are decreasing biodiversity and changing the climate worldwide. Both global change drivers have been shown to affect ecosystem functioning, but they may also act in concert in a non-additive way. We studied early-stage litter mass loss rates and soil microbial properties (basal respiration and microbial biomass) during the summer season in response to plant species richness and summer drought in a large grassland biodiversity experiment, the Jena Experiment, Germany. In line with our expectations, decreasing plant diversity and summer drought decreased litter mass loss rates and soil microbial properties. In contrast to our hypotheses, however, this was only true for mass loss of standard litter (wheat straw) used in all plots, and not for plant community-specific litter mass loss. We found no interactive effects between global change drivers, that is, drought reduced litter mass loss rates and soil microbial properties irrespective of plant diversity. High mass loss rates of plant community-specific litter and low responsiveness to drought relative to the standard litter indicate that soil microbial communities were adapted to decomposing community-specific plant litter material including lower susceptibility to dry conditions during summer months. Moreover, higher microbial enzymatic diversity at high plant diversity may have caused elevated mass loss of standard litter. Our results indicate that plant diversity loss and summer drought independently impede soil processes. However, soil decomposer communities may be highly adapted to decomposing plant community-specific litter material, even in situations of environmental stress. Results of standard litter mass loss moreover suggest that decomposer communities under diverse plant communities are able to cope with a greater variety of plant inputs possibly making them less responsive to biotic changes.

  7. Rotating Unbalanced-Mass devices for scanning: Results from the proof-of-concept test

    NASA Technical Reports Server (NTRS)

    Alhorn, Dean C.; Polites, Michael E.

    1994-01-01

    Rotating unbalanced-mass (RUM) devices are a new way to scan space-based, balloon-borne, and ground-based gimbaled payloads, like x-ray and gamma-ray telescopes. They can also be used to scan free-flying spacecraft. Circular scans, linear scans, and raster scans can be generated. A pair of RUM devices generates the basic scan motion and an auxiliary control system using torque motors, control moment gyros, or reaction wheels keeps the scan centered on the target and produces some complementary motion for raster scanning. Previous analyses and simulation results show that this approach offers significant power savings compared to scanning only with the auxiliary control system, especially with large payloads and high scan frequencies. However, these claims have never been proven until now. This paper describes a laboratory experiment which tests the concept of scanning a gimbaled payload with RUM devices. The test results are compared with those from a computer simulation model of the experiment and the differences are discussed.

  8. Floating wetland islands as a method of nitrogen mass reduction: results of a 1 year test.

    PubMed

    Vázquez-Burney, Rafael; Bays, James; Messer, Ryan; Harris, Jeffrey

    2015-01-01

    Floating wetland islands (FWIs) were tested in Pasco County, Florida, as a method of reducing total nitrogen (TN) in reclaimed water during reservoir storage. The Pasco County Master Reuse System (PCMRS) is a regional reclaimed-water transmission and distribution system providing wastewater effluent disposal for the county. Total daily mass loading from reclaimed water is limited by nitrogen content in the PCMRS watershed. To test TN reduction efficacy, 20 FWIs were constructed, installed, and monitored in a lined pond receiving PCMRS reclaimed water. In total, 149 m2 of FWIs were installed, distributed as a connected network covering 1,122 m2, or 7% of pond area. Pond hydraulic residence time averaged 15.7 days. Treatment performance was assessed during three consecutive periods: establishment (first 6 months of grow-in), performance (8 months immediately following grow-in), and control (3 months after the FWIs were removed from the pond). The FWIs enhanced pond nitrogen removal capacity by 32%. The primary effect of the FWIs was to decrease organic nitrogen in the pond outflow. By evaluating the difference between the performance and control periods, an incremental TN removal rate for the FWIs was calculated to be 4.2 kg N/m2 FWI per year.

  9. Psychometric properties of the Internet Addiction Test in Turkish.

    PubMed

    Kaya, Fatih; Delen, Erhan; Young, Kimberly S

    2015-12-21

    Background and aims In this study, the Internet Addiction Test (IAT) was adapted to Turkish language, which was originally developed by Young (1998) in English to measure the presence and severity of the Internet dependency. The main purpose was to ensure that the psychometric features and the factor structure of the test were suitable for Turkish university students. Method The study was conducted in two sequent phases. Participants were 990 undergraduate students from several public universities in Turkey. Results In the first phase, an exploratory factor analysis (EFA) was applied to figure out the factor structure of the Turkish version of the IAT. The EFA revealed four factors, which explained 46.02% of the total variance. In the following phase, a confirmatory factor analysis (CFA) was conducted with a different sample, to verify the factor structure that was found in the initial EFA. The CFA resulted four-factor model was satisfactory for the Turkish version of the IAT. These four factors were named as Mood, Relationship, Responsibilities, and Duration. Conclusions Based on the findings, the administration of Turkish version of the IAT provided acceptable results on undergraduate students.

  10. Psychometric properties of the Internet Addiction Test in Turkish.

    PubMed

    Kaya, Fatih; Delen, Erhan; Young, Kimberly S

    2016-03-01

    Background and aims In this study, the Internet Addiction Test (IAT) was adapted to Turkish language, which was originally developed by Young (1998) in English to measure the presence and severity of the Internet dependency. The main purpose was to ensure that the psychometric features and the factor structure of the test were suitable for Turkish university students. Method The study was conducted in two sequent phases. Participants were 990 undergraduate students from several public universities in Turkey. Results In the first phase, an exploratory factor analysis (EFA) was applied to figure out the factor structure of the Turkish version of the IAT. The EFA revealed four factors, which explained 46.02% of the total variance. In the following phase, a confirmatory factor analysis (CFA) was conducted with a different sample, to verify the factor structure that was found in the initial EFA. The CFA resulted four-factor model was satisfactory for the Turkish version of the IAT. These four factors were named as Mood, Relationship, Responsibilities, and Duration. Conclusions Based on the findings, the administration of Turkish version of the IAT provided acceptable results on undergraduate students.

  11. Psychometric properties of the Internet Addiction Test in Turkish

    PubMed Central

    Kaya, Fatih; Delen, Erhan; Young, Kimberly S.

    2016-01-01

    Background and aims In this study, the Internet Addiction Test (IAT) was adapted to Turkish language, which was originally developed by Young (1998) in English to measure the presence and severity of the Internet dependency. The main purpose was to ensure that the psychometric features and the factor structure of the test were suitable for Turkish university students. Method The study was conducted in two sequent phases. Participants were 990 undergraduate students from several public universities in Turkey. Results In the first phase, an exploratory factor analysis (EFA) was applied to figure out the factor structure of the Turkish version of the IAT. The EFA revealed four factors, which explained 46.02% of the total variance. In the following phase, a confirmatory factor analysis (CFA) was conducted with a different sample, to verify the factor structure that was found in the initial EFA. The CFA resulted four-factor model was satisfactory for the Turkish version of the IAT. These four factors were named as Mood, Relationship, Responsibilities, and Duration. Conclusions Based on the findings, the administration of Turkish version of the IAT provided acceptable results on undergraduate students. PMID:28092191

  12. Multilayer material properties of aorta determined from nanoindentation tests

    PubMed Central

    Hemmasizadeh, Ali; Autieri, Michael; Darvish, Kurosh

    2013-01-01

    In a wide range of biomechanical modeling of aorta from traumatic injury to stent grafts, the arterial wall has been considered as a single homogeneous layer vessel, ignoring the fact that arteries are composed of distinct anatomical layers with different mechanical characteristics. In this study, using a custom-made nanoindentation technique, changes in the mechanical properties of porcine thoracic aorta wall in the radial direction were characterized using a quasi-linear viscoelastic model. Two layers of equal thickness were mechanically distinguishable in descending aorta based on the radial variations in the instantaneous Young's modulus E and reduced relaxation function G(t). Overall, comparison of E and G∞ of the outer half (70.27 ± 2.47 kPa and 0.35 ± 0.01) versus the inner half (60.32 ± 1.65 kPa and 0.33 ± 0.01) revealed that the outer half was stiffer and showed less relaxation. The results were used to explain local mechanisms of deformation, force transmission, tear propagation and failure in arteries. PMID:23123343

  13. Multilayer material properties of aorta determined from nanoindentation tests.

    PubMed

    Hemmasizadeh, Ali; Autieri, Michael; Darvish, Kurosh

    2012-11-01

    In a wide range of biomechanical modeling of aorta from traumatic injury to stent grafts, the arterial wall has been considered as a single homogeneous layer vessel, ignoring the fact that arteries are composed of distinct anatomical layers with different mechanical characteristics. In this study, using a custom-made nanoindentation technique, changes in the mechanical properties of porcine thoracic aorta wall in the radial direction were characterized using a quasi-linear viscoelastic model. Two layers of equal thickness were mechanically distinguishable in descending aorta based on the radial variations in the instantaneous Young's modulus E and reduced relaxation function G(t). Overall, comparison of E and G(∞) of the outer half (70.27±2.47 kPa and 0.35±0.01) versus the inner half (60.32±1.65 kPa and 0.33±0.01) revealed that the outer half was stiffer and showed less relaxation. The results were used to explain local mechanisms of deformation, force transmission, tear propagation and failure in arteries.

  14. Implementing the Computer-Adaptive Sequential Testing (CAST) Framework To Mass Produce High Quality Computer-Adaptive and Mastery Tests.

    ERIC Educational Resources Information Center

    Luecht, Richard M.

    Computerized testing has created new challenges for the production and administration of test forms. This paper describes a multi-stage, testlet-based framework for test design, assembly, and administration called computer-adaptive sequential testing (CAST). CAST is a structured testing approach that is amenable to both adaptive and mastery…

  15. Predictive Properties of the Gesell School Readiness Screening Test within Samples from Two Treatment Contexts.

    ERIC Educational Resources Information Center

    Banerji, Madhabi

    The predictive properties of the Gesell School Readiness Screening Test (GSRT) were examined, taking into account the stated purposes of the test and the context of test use. Two samples were used: (1) a control sample of 55 students (21 males and 34 females) whose GSRT scores were not used for placement or tracking; and (2) a treatment sample of…

  16. Models for determining the geometrical properties of halo coronal mass ejections

    NASA Astrophysics Data System (ADS)

    Zhao, X.; Liu, Y.

    2005-12-01

    To this day, the prediction of space weather effects near the Earth suffer from a fundamental problem: the necessary condition for determining whether or not and when a part of the huge interplanetary counterpart (ICME) of frontside halo coronal mass ejections (CMEs) is able to hit the Earth and generate goemagnetic storms, i.e., the real angular width, the propagation direction and speed of the CMEs, cannot be measured directly because of the unfavorable geometry. To inverse these geometrical and kinematical properties we have recently developed a few geometrical models, such as the cone model, the ice cream cone model, and the spherical cone model. The inversing solution of the cone model for the 12 may 1997 halo CME has been used as an input to the ENLIL model (a 3D MHD solar wind code) and successfully predicted the ICME near the Earth (Zhao, Plukett & Liu, 2002; Odstrcil, Riley & Zhao, 2004). After briefly describing the geometrical models this presentation will discuss: 1. What kind of halo CMEs can be inversed? 2. How to select the geometrical models given a specific halo CME? 3. Whether or not the inversing solution is unique?

  17. Three-Dimensional Properties of Coronal Mass Ejections from STEREO/SECCHI Observations

    NASA Astrophysics Data System (ADS)

    Bosman, E.; Bothmer, V.; Nisticò, G.; Vourlidas, A.; Howard, R. A.; Davies, J. A.

    2012-11-01

    We identify 565 coronal mass ejections (CMEs) between January 2007 and December 2010 in observations from the twin STEREO/SECCHI/COR2 coronagraphs aboard the STEREO mission. Our list is in full agreement with the corresponding SOHO/LASCO CME Catalog (http://cdaw.gsfc.nasa.gov/CME_list/) for events with angular widths of 45∘ and up. The monthly event rates behave similarly to sunspot rates showing a three- to fourfold rise between September 2009 and March 2010. We select 51 events with well-defined white-light structure and model them as three-dimensional (3D) flux ropes using a forward-modeling technique developed by Thernisien, Howard and Vourlidas (Astrophys. J. 652, 763 - 773, 2006). We derive their 3D properties and identify their source regions. We find that the majority of the CME flux ropes (82 %) lie within 30∘ of the solar equator. Also, 82 % of the events are displaced from their source region, to a lower latitude, by 25∘ or less. These findings provide strong support for the deflection of CMEs towards the solar equator reported in earlier observations, e.g. by Cremades and Bothmer ( Astron. Astrophys. 422, 307 - 322, 2004).

  18. A laboratory test setup for in situ measurements of the dielectric properties of catalyst powder samples under reaction conditions by microwave cavity perturbation: set up and initial tests.

    PubMed

    Dietrich, Markus; Rauch, Dieter; Porch, Adrian; Moos, Ralf

    2014-09-10

    The catalytic behavior of zeolite catalysts for the ammonia-based selective catalytic reduction (SCR) of nitrogen oxides (NOX) depends strongly on the type of zeolite material. An essential precondition for SCR is a previous ammonia gas adsorption that occurs on acidic sites of the zeolite. In order to understand and develop SCR active materials, it is crucial to know the amount of sorbed ammonia under reaction conditions. To support classical temperature-programmed desorption (TPD) experiments, a correlation of the dielectric properties with the catalytic properties and the ammonia sorption under reaction conditions appears promising. In this work, a laboratory test setup, which enables direct measurements of the dielectric properties of catalytic powder samples under a defined gas atmosphere and temperature by microwave cavity perturbation, has been developed. Based on previous investigations and computational simulations, a resonator cavity and a heating system were designed, installed and characterized. The resonator cavity is designed to operate in its TM010 mode at 1.2 GHz. The first measurement of the ammonia loading of an H-ZSM-5 zeolite confirmed the operating performance of the test setup at constant temperatures of up to 300 °C. It showed how both real and imaginary parts of the relative complex permittivity are strongly correlated with the mass of stored ammonia.

  19. A Laboratory Test Setup for in Situ Measurements of the Dielectric Properties of Catalyst Powder Samples under Reaction Conditions by Microwave Cavity Perturbation: Set up and Initial Tests

    PubMed Central

    Dietrich, Markus; Rauch, Dieter; Porch, Adrian; Moos, Ralf

    2014-01-01

    The catalytic behavior of zeolite catalysts for the ammonia-based selective catalytic reduction (SCR) of nitrogen oxides (NOX) depends strongly on the type of zeolite material. An essential precondition for SCR is a previous ammonia gas adsorption that occurs on acidic sites of the zeolite. In order to understand and develop SCR active materials, it is crucial to know the amount of sorbed ammonia under reaction conditions. To support classical temperature-programmed desorption (TPD) experiments, a correlation of the dielectric properties with the catalytic properties and the ammonia sorption under reaction conditions appears promising. In this work, a laboratory test setup, which enables direct measurements of the dielectric properties of catalytic powder samples under a defined gas atmosphere and temperature by microwave cavity perturbation, has been developed. Based on previous investigations and computational simulations, a resonator cavity and a heating system were designed, installed and characterized. The resonator cavity is designed to operate in its TM010 mode at 1.2 GHz. The first measurement of the ammonia loading of an H-ZSM-5 zeolite confirmed the operating performance of the test setup at constant temperatures of up to 300 °C. It showed how both real and imaginary parts of the relative complex permittivity are strongly correlated with the mass of stored ammonia. PMID:25211199

  20. The Low-mass Population in the Young Cluster Stock 8: Stellar Properties and Initial Mass Function

    NASA Astrophysics Data System (ADS)

    Jose, Jessy; Herczeg, Gregory J.; Samal, Manash R.; Fang, Qiliang; Panwar, Neelam

    2017-02-01

    The evolution of H ii regions/supershells can trigger a new generation of stars/clusters at their peripheries, with environmental conditions that may affect the initial mass function, disk evolution, and star formation efficiency. In this paper we study the stellar content and star formation processes in the young cluster Stock 8, which itself is thought to be formed during the expansion of a supershell. We present deep optical photometry along with JHK and 3.6 and 4.5 μm photometry from UKIDSS and Spitzer-IRAC. We use multicolor criteria to identify the candidate young stellar objects in the region. Using evolutionary models, we obtain a median log(age) of ∼6.5 (∼3.0 Myr) with an observed age spread of ∼0.25 dex for the cluster. Monte Carlo simulations of the population of Stock 8, based on estimates for the photometric uncertainty, differential reddening, binarity, and variability, indicate that these uncertainties introduce an age spread of ∼0.15 dex. The intrinsic age spread in the cluster is ∼0.2 dex. The fraction of young stellar objects surrounded by disks is ∼35%. The K-band luminosity function of Stock 8 is similar to that of the Trapezium cluster. The initial mass function (IMF) of Stock 8 has a Salpeter-like slope at >0.5 M ⊙ and flattens and peaks at ∼0.4 M ⊙, below which it declines into the substellar regime. Although Stock 8 is surrounded by several massive stars, there seems to be no severe environmental effect in the form of the IMF due to the proximity of massive stars around the cluster.

  1. A large scale test dataset to determine optimal retention index threshold based on three mass spectral similarity measures

    PubMed Central

    Zhang, Jun; Koo, Imhoi; Wang, Bing; Gao, Qing-Wei; Zheng, Chun-Hou; Zhang, Xiang

    2012-01-01

    Retention index (RI) is useful for metabolite identification. However, when RI is integrated with mass spectral similarity for metabolite identification, many controversial RI threshold setup are reported in literatures. In this study, a large scale test dataset of 5844 compounds with both mass spectra and RI information were created from National Institute of Standards and Technology (NIST) repetitive mass spectra (MS) and RI library. Three MS similarity measures: NIST composite measure, the real part of Discrete Fourier Transform (DFT.R) and the detail of Discrete Wavelet Transform (DWT.D) were used to investigate the accuracy of compound identification using the test dataset. To imitate real identification experiments, NIST MS main library was employed as reference library and the test dataset was used as search data. Our study shows that the optimal RI thresholds are 22, 15, and 15 i.u. for the NIST composite, DFT.R and DWT.D measures, respectively, when the RI and mass spectral similarity are integrated for compound identification. Compared to the mass spectrum matching, using both RI and mass spectral matching can improve the identification accuracy by 1.7%, 3.5%, and 3.5% for the three mass spectral similarity measures, respectively. It is concluded that the improvement of RI matching for compound identification heavily depends on the method of MS spectral similarity measure and the accuracy of RI data. PMID:22771253

  2. Test of timing properties of the Photek 240 PMT

    SciTech Connect

    Ronzhin, A.; Albrow, M.; Demarteau, M.; Pronko, S.; Ramberg, E.; Zatserklyaniy, A.; /Puerto Rico U., Mayaguez

    2010-01-01

    Timing measurements of Silicon Photomultipliers (SiPM) at the picosecond level were performed at Fermilab. The core timing resolution of the electronic measurement technique is approximately 2 picoseconds. The single photoelectron time resolution (SPTR) was measured for the signals coming from the SiPM's. A SPTR of about one hundred picoseconds was obtained for SiPM's illuminated by laser pulses. The dependence of the SPTR on applied bias voltage and on the wavelength of the light was measured. A simple model is proposed to explain the difference in the SPTR for blue and red light. A time of flight system based on the SiPM's, with quartz Cherenkov radiators, was tested in a proton beam at Fermilab. The time resolution obtained is 35 picoseconds per SiPM. Finally, requirements for the SiPM's temperature and bias voltage stability to maintain the time resolution are discussed.

  3. Peanut protein reduces body protein mass and alters skeletal muscle contractile properties and lipid metabolism in rats.

    PubMed

    Jacques, Hélène; Leblanc, Nadine; Papineau, Roxanne; Richard, Denis; Côté, Claude H

    2010-05-01

    It is well known that diets high in nuts or peanuts favourably affect plasma lipid concentrations. However, few studies have examined the effects of nut and peanut protein (PP) on body composition and skeletal muscle properties. The present study was aimed at evaluating the effect of dietary PP compared with two animal proteins, casein (C) and cod protein (CP) on body composition, skeletal muscle contractile properties and lipid metabolism in rats. Thirty-two male rats were assigned to one of the following four diets containing either C, CP, PP or C+peanut protein (CPP, 50:50) mixture. After 28 d of ad libitum feeding and after 12-h fast, blood, liver and muscle were collected for measurements of plasma and hepatic cholesterol and TAG, plasma glucose and insulin and contractile properties. Rats fed with the low-quality protein, PP, had lower body weight gain, body protein mass, soleus mass and liver weight than those fed with the high-quality dietary proteins, C and CP. PP also caused a deficit in contractile properties in soleus. Likewise, PP increased plasma cholesterol and body fat mass compared with CP. However, these elevations were accompanied with increased hepatic TAG concentrations and lowered intestinal fat excretion. These results show that PP intake alters body composition by reducing skeletal muscle mass and liver weight as well as muscle contractility and lipid metabolism. Adding a complete protein such as C might partially counteract these adverse effects.

  4. Soil test phosphorus dynamics in animal waste amended soils: using P mass balance approach.

    PubMed

    Shafqat, Mustafa N; Pierzynski, Gary M

    2013-01-01

    Soil test phosphorus (STP) is commonly used for phosphorus (P) fertilizer recommendations in agriculture and in risk assessment of offsite P movement from environmental perspectives. Present guidelines do not differentiate between the P sources and assume that P added to the soil would behave alike. The objective of this study was to understand the influence of different animal P sources applied at three different rates on changes in STP in many different soils using P mass balance approach. Six P sources consisting of three types of monogastric, two ruminant and triple super phosphate (TSP) applied at 0, 50, and 150 mg P kg(-1) in six different soils. Corn (Zea mays L.) was used to remove P and total of seven harvests were achieved. The STP (Bray 1P) was monitored at T(0) and after each harvest and relationship was developed between STP and net P addition/removal to compute the slope. Prior to crop P removal, the Turkey (Meleagris gallopava) litter (TL) produced the smallest slope at both rates and across all soils. Most P sources resulted large slope values in the Woodson soil. The slope value progressively decreased from higher rate to lower rate to the control treatment in P mass balance study. Soil clay content, initial STP, soil pH, and soil organic matter levels were involved in explaining variations in slope value in TL, while initial STP and clay content in Hog (Sus scrofa) manure (HM) and biosolid (SS) amended soils in net P addition/removal study. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. The relationship between body mass index and cardiopulmonary exercise testing in chronic systolic heart failure.

    PubMed

    Horwich, Tamara B; Leifer, Eric S; Brawner, Clinton A; Fitz-Gerald, Meredith B; Fonarow, Gregg C

    2009-10-01

    Cardiopulmonary exercise testing (CPX) in patients with systolic heart failure (HF) is important for determining HF prognosis and helping guide timing of heart transplantation. Although approximately 20% to 30% of patients with HF are obese (body mass index [BMI] >30 kg/m(2)), the impact of BMI on CPX results is not well established. The objective of this study was to assess the relationship between BMI and CPX variables, including peak oxygen uptake (VO(2)) at ventilatory threshold, oxygen pulse, and ventilation-carbon dioxide production ratio. Consecutive patients with systolic HF (n = 2,324) enrolled in the Heart Failure and A Controlled Trial Investigating Outcomes of Exercise Training trial who had baseline BMI recorded were included in this study. Subjects were divided into strata based on BMI: underweight (BMI <18.5 kg/m(2)), normal weight (BMI 18.5-24.9 kg/m(2)), overweight (BMI 25.0-29.9 kg/m(2)), obese I (BMI 30-34.9 kg/m(2)), obese II (BMI 35-39.9 kg/m(2)), and obese III (BMI > or = 40 kg/m(2)). Obese III, but not overweight; obese I; or obese II was associated with decreased peak VO(2) (mL kg(-1) min(-1)) compared to normal weight status. Increasing BMI category was inversely related to ventilation/carbon dioxide production (V(E)/V(CO2)) ratio (P < .0001). On multivariable analysis, BMI was a significant independent predictor of peak VO(2) (partial R(2) = 0.07, P < .0001) and V(E)/V(CO2) slope (partial R(2) = 0.03, P < .0001) in patients with chronic systolic HF. Body mass index is significantly associated with key CPX fitness variables in patients with HF. The influence of BMI on the prognostic value of CPX in HF requires further evaluation in longitudinal studies.

  6. On-Line, Gyro-Based, Mass-Property Identification for Thruster-Controlled Spacecraft Using Recursive Least Squares

    NASA Technical Reports Server (NTRS)

    Wilson, Edward; Lages, Chris; Mah, Robert; Clancy, Daniel (Technical Monitor)

    2002-01-01

    Spacecraft control, state estimation, and fault-detection-and-isolation systems are affected by unknown v aerations in the vehicle mass properties. It is often difficult to accurately measure inertia terms on the ground, and mass properties can change on-orbit as fuel is expended, the configuration changes, or payloads are added or removed. Recursive least squares -based algorithms that use gyro signals to identify the center of mass and inverse inertia matrix are presented. They are applied in simulation to 3 thruster-controlled vehicles: the X-38 and Mini-AERCam under development at NASA-JSC, and the SAM, an air-bearing spacecraft simulator at the NASA-Ames Smart Systems Research Lab (SSRL).

  7. Recent developments in testing techniques for elastic mechanical properties of 1-D nanomaterials.

    PubMed

    Wang, Weidong; Li, Shuai; Zhang, Hongti; Lu, Yang

    2015-01-01

    One-dimensional (1-D) nanomaterials exhibit great potentials in their applications to functional materials, nano-devices and systems owing to their excellent properties. In the past decade, considerable studies have been done, with new patents being developed, on these 1-D building blocks for for their mechanical properties, especially elastic properties, which provide a solid foundation for the design of nanoelectromechanical systems (NEMS) and predictions of reliability and longevity for their devices. This paper reviews some of the recent investigations on techniques as well as patents available for the quantitative characterization of the elastic behaviors of various 1-D nanomaterials, with particular focus on on-chip testing system. The review begins with an overview of major testing methods for 1-D nanostructures' elastic properties, including nanoindentation testing, AFM (atomic force microscopy) testing, in situ SEM (scanning electron microscopy) testing, in situ TEM (transmission electron microscopy) testing and the testing system on the basis of MEMS (micro-electro-mechanical systems) technology, followed by advantages and challenges of each testing approach. This review also focuses on the MEMS-based testing apparatus, which can be actuated and measured inside SEM and TEM with ease, allowing users to highly magnify the continuous images of the specimen while measuring load electronically and independently. The combination of on-chip technologies and the in situ electron microscopy is expected to be a potential testing technique for nanomechanics. Finally, details are presented on the key challenges and possible solutions in the implementation of the testing techniques referred above.

  8. Pseudo-automatic characterization of the morphological and kinematical properties of coronal mass ejections using a texture-based technique

    NASA Astrophysics Data System (ADS)

    Braga, Carlos Roberto; Dal Lago, Alisson; Stenborg, Guillermo

    2013-05-01

    The white light coronagraphs onboard SOHO (LASCO-C2 and -C3) and most recently STEREO (SECCHI -COR1 and -COR2) have detected a myriad of coronal mass ejections (CME). They are a key component of space weather and under certain conditions they can become geo-effective, hence the importance of their kinematic characterization to help predict their effects. However, there is still a lot of debate on how to define the event boundaries for space weather purposes, which in turn makes it difficult to agree on their kinematic properties. That lack of agreement is reflected in both the manual and automated CME catalogs in existence. To contribute to a more objective definition and characterization of white-light coronagraph events, Goussies et al. (2010) introduced recently the concept of "texture of the event". Based on that property, they developed a supervised segmentation algorithm to allow the automatic tracking of dynamic events observed in the coronagraphs field of view, which is called CORonal SEgmentation Technique (CORSET). In this work, we have enhanced the capabilities of the algorithm by adding several new functionalities, namely the automatic computation of different morphological and kinematic parameters. We tested its performance on 57 well-studied limb CME events observed with the LASCO coronagraphs between 1997 and 2001, and compared the parameters obtained with those from three existent CME lists: two of them obtained from an observer-based detection and tracking method (i.e., two manual catalogs), and the other one based on the automated detection and characterization of the CME events (i.e., a fully automated catalog). We found that 51 events could be tracked and quantified in agreement with the CME definition. In general terms, the position angle, and the radial and expansion speeds are in agreement with the manual catalogs used for comparison. On the other hand, some discrepancies between CORSET and the automated catalog were found, which can be

  9. Pseudo-automatic characterization of the morphological and kinematical properties of Coronal Mass Ejections using a texture-based technique

    NASA Astrophysics Data System (ADS)

    Braga, Carlos Roberto; Dal Lago, Alisson; Stenborg, Guillermo

    2012-07-01

    The white light coronagraphs onboard SOHO (LASCO-C2 and -C3) and most recently STEREO (SECCHI -COR1 and -COR2) have detected a myriad of coronal events. They are a key component of space weather and under certain conditions they can become geo-effective, hence the importance of their kinematical characterization to help predict their effects. However, there is still a lot of debate on how to define the event boundaries for space weather purposes, which in turn makes it difficult to agree on their kinematical properties. That lack of agreement is reflected in both manual and automated Coronal Mass Ejections (CME) catalogs in existence. To contribute to a more objective definition and characterization of white-light coronagraph events, Goussies et al. (2010) introduced the concept of "texture of the event". Based on that property, they developed a supervised segmentation algorithm to allow the automatic tracking of dynamic coronal events observed in the field of view of a coronagraph instrument. In this work, we have enhanced the capabilities of the algorithm by adding several new functionalities, namely the automatic computation of different morphological and kinematical parameters. We tested its performance on 57 well-studied limb CME events observed with the LASCO coronagraphs between 1997 and 2001, and compared the parameters obtained with those from two manual catalogs. We found that 51 events could be tracked and quantified in agreement with the CME definition. In general terms, the position angle, and the radial and expansion speeds are all in agreement within the observational error with the values in the manual catalogs used for comparison. The width of the events although, exhibits a significant difference in some events. This technique can be applied to any new set of CMEs been observed in the last years using both data from STEREO and SOHO.

  10. Study on properties and testing methods of thermo-responsive cementing system for well cementing in heavy oil thermal recovery

    NASA Astrophysics Data System (ADS)

    Li, Lianjiang

    2017-08-01

    In this paper, thermo-responsive cement slurry system were being developed, the properties of conventional cement slurry, compressive strength high temperature of cement sheath, mechanical properties of cement sheath and thermal properties of cement sheath were being tested. Results were being used and simulated by Well-Life Software, Thermo-responsive cement slurry system can meet the requirements of heavy oil thermal recovery production. Mechanical and thermal properties of thermo-responsive cement sheath were being tested. Tensile fracture energy of the thermo-responsive cement sheath is larger than conventional cement. The heat absorption capacity of conventional cement sheath is larger than that of thermo-responsive cement sheath, this means more heat is needed for the unit mass once increasing 1.0 °C, which also indicates that thermo-responsive cement own good heat insulating and preservation effects. The heat conductivity coefficient and thermal expansion coefficient of thermo-responsive cement is less than and conventional cement, this means that thermo-responsive cement have good heat preservation and insulation effects with good thermal expansion stabilities.

  11. Mechanical properties test data of Alloy 718 for liquid metal fast breeder reactor applications

    SciTech Connect

    Korth, G.E.

    1983-01-01

    Mechanical property test data are reported for Alloy 718 with two heat treatments: conventional heat treatment (CHT) for base metal and Idaho National Engineering Laboratory (INEL) heat treatment (IHT) for base and weld metal. Tests were conducted in air from 24 to 704{degree}C and include elastic properties (Young's modulus, shear modulus, Poisson's ratio), tensile properties, creep-rupture properties, fatigue properties, creep-fatigue properties, and Charpy impact behavior. Effects of long term thermal aging at 538, 593, 649, and 704{degree}C for times to 25,000 h are also reported for CHT material (tensile, creep-rupture, fatigue, and Charpy), and IHT material (tensile, and Charpy). 18 refs., 63 figs., 36 tabs.

  12. Optimizing tuning masses for helicopter rotor blade vibration reduction including computed airloads and comparison with test data

    NASA Technical Reports Server (NTRS)

    Pritchard, Jocelyn I.; Adelman, Howard M.; Walsh, Joanne L.; Wilbur, Matthew L.

    1992-01-01

    The development and validation of an optimization procedure to systematically place tuning masses along a rotor blade span to minimize vibratory loads are described. The masses and their corresponding locations are the design variables that are manipulated to reduce the harmonics of hub shear for a four-bladed rotor system without adding a large mass penalty. The procedure incorporates a comprehensive helicopter analysis to calculate the airloads. Predicting changes in airloads due to changes in design variables is an important feature of this research. The procedure was applied to a one-sixth, Mach-scaled rotor blade model to place three masses and then again to place six masses. In both cases the added mass was able to achieve significant reductions in the hub shear. In addition, the procedure was applied to place a single mass of fixed value on a blade model to reduce the hub shear for three flight conditions. The analytical results were compared to experimental data from a wind tunnel test performed in the Langley Transonic Dynamics Tunnel. The correlation of the mass location was good and the trend of the mass location with respect to flight speed was predicted fairly well. However, it was noted that the analysis was not entirely successful at predicting the absolute magnitudes of the fixed system loads.

  13. Antibacterial properties of aged dental cements evaluated by direct-contact and agar diffusion tests.

    PubMed

    Lewinstein, Israel; Matalon, Shlomo; Slutzkey, Shimshon; Weiss, Ervin I

    2005-04-01

    Since failure of fixed partial dentures is most frequently caused by caries, it would be advantageous if cements possessed antibacterial properties. The purpose of this study was to evaluate the antibacterial properties of 3 dental cements using the direct-contact test and agar diffusion test. For the direct-contact test, wells (n = 4) of microtiter plates were coated with the tested cements (Harvard cement, Duralon, and Ketac-Cem) while Streptococcus mutans suspension was placed directly on the cements. Bacterial growth was evaluated by a temperature-controlled microplate spectrophotometer. Eight wells of bacteria without the tested cements served as the positive control. Six wells of the tested cement without bacteria served as the negative control. For the agar diffusion test, triplicate specimens of freshly mixed cements were poured into uniform wells (5 mm in diameter) punched in the agar plates inoculated with Streptococcus mutans . After incubation at 37 degrees C for 24 hours, the agar plates were examined for bacterial growth and the diameter of the halo formed in the bacterial lawn was measured. In both tests, each cement was mixed in 2 different powder/liquid ratios. For the direct-contact test, data were initially recorded after 1 hour of incubation. Additional experiments were performed on specimens that were aged for 24 hours, 1 week, 1 month, and 3 months before assessment by either direct-contact test or agar diffusion test. The data were subjected to 1-way ANOVA with the Tukey post hoc test (alpha=.05). Compared with the control group, Duralon and Harvard cements demonstrated antibacterial properties even after 3 months with the direct-contact test (P <.002), while Ketac-Cem exhibited no antibacterial properties. In the agar diffusion test, no antibacterial activity was observed for any of the tested cements. The different powder/liquid ratios had a negligible effect on the antibacterial properties of the tested cements. Within the limitations of

  14. Test system accurately determines tensile properties of irradiated metals at cryogenic temperatures

    NASA Technical Reports Server (NTRS)

    Levine, P. J.; Skalka, R. J.; Vandergrift, E. F.

    1967-01-01

    Modified testing system determines tensile properties of irradiated brittle-type metals at cryogenic temperatures. The system includes a lightweight cryostat, split-screw grips, a universal joint, and a special temperature control system.

  15. Evolution of Intermediate Redshift Galaxies Physical Properties and Mass-Metallicity Relation

    NASA Astrophysics Data System (ADS)

    Xia, Lifang

    The first part of this dissertation presents the implementation of Bayesian statistics with galaxy surface luminosity (SL) prior probabilities to improve the accuracy of photometric redshifts. The addition of the SL prior probability helps break the degeneracy of spectro-photometric redshifts (SPZs) between low redshift 4000 A break galaxies and high redshift Lyman break galaxies which are mostly catastrophic outliers. For a sample of 1138 galaxies with spectroscopic redshifts in the GOODS North and South fields at z < 1.6, the application of the surface luminosity prior reduces the fraction of galaxies with redshift deviation sigma(z) > 0.2 from 15.0% to 10.4%. The second part of this dissertation presents the study of the chemical evolution of the star-forming galaxies. The Hubble Space Telescope Probing Evolution and Reionization Spectroscopically (PEARS) grism Survey effectively selects emission line galaxies (ELGs) to m AB ˜ 27. Follow-up Magellan LDSS3+IMACS spectroscopy of the HST/ACS PEARS ELGs confirms an accuracy of sigma_z = 0.006 for the HST/ACS PEARS grism redshifts. The luminosity-metallicity (L-Z) relation and the mass-metallicity (M-Z) relation of the PEARS ELGs at z ˜ 0.6 are offset by ˜ - 0.8 dex in metallicity for a given rest-frame B absolute magnitude and stellar mass relative to the local relations from SDSS galaxies. The offsets in both relations are ˜ - 0.4 dex larger than that given by other samples at same redshifts, which are demonstrated to be due to the selection of different physical properties of the PEARS ELGs: low metallicities, very blue colors, small sizes, compact disturbed morphologies, high SSFR > 10-9 yr-1, and high gas fraction. The downsizing effect, the tidal interacting induced inflow of metal-poor gas, and the SNe driven galactic winds outflows, may account for the significant offset of the PEARS galaxies in the L-Z and the M-Z relations relative to the local relations. The detection of the emission lines of ELGs down

  16. Psychometric Properties of Raw and Scale Scores on Mixed-Format Tests

    ERIC Educational Resources Information Center

    Kolen, Michael J.; Lee, Won-Chan

    2011-01-01

    This paper illustrates that the psychometric properties of scores and scales that are used with mixed-format educational tests can impact the use and interpretation of the scores that are reported to examinees. Psychometric properties that include reliability and conditional standard errors of measurement are considered in this paper. The focus is…

  17. Psychometric Properties of Raw and Scale Scores on Mixed-Format Tests

    ERIC Educational Resources Information Center

    Kolen, Michael J.; Lee, Won-Chan

    2011-01-01

    This paper illustrates that the psychometric properties of scores and scales that are used with mixed-format educational tests can impact the use and interpretation of the scores that are reported to examinees. Psychometric properties that include reliability and conditional standard errors of measurement are considered in this paper. The focus is…

  18. Physical properties and evolutionary time scales of disks around solar-type and intermediate mass stars

    NASA Technical Reports Server (NTRS)

    Strom, Stephen E.; Edwards, Suzan

    1993-01-01

    Recent observations of circumstellar disks and their evolutionary timescales are reviewed. It is concluded that disks appear to be a natural outcome of the star-formation process. The disks surrounding young stars initially are massive, with optically thick structures comprised of gas and micron-sized grains. Disk masses are found to range from 0.01 to 0.2 solar masses for solar-type PMS stars, and from 0.01 to 6 solar masses for young, intermediate mass stars. Massive, optically thick accretion disks have accretion rates between 10 exp -8 and 10 exp -6 solar masses/yr for solar type PMS stars and between 10 exp -6 and 10 exp -4 solar masses/yr for intermediate stars. The results suggest that a significant fraction of the mass comprising the star may have passed through a circumstellar accretion disk.

  19. Polymeric spatial resolution test patterns for mass spectrometry imaging using nano-thermal analysis with atomic force microscopy

    DOE PAGES

    Tai, Tamin; Kertesz, Vilmos; Lin, Ming -Wei; ...

    2017-05-11

    As the spatial resolution of mass spectrometry imaging technologies has begun to reach into the nanometer regime, finding readily available or easily made resolution reference materials has become particularly challenging for molecular imaging purposes. This study describes the fabrication, characterization and use of vertical line array polymeric spatial resolution test patterns for nano-thermal analysis/atomic force microscopy/mass spectrometry chemical imaging.

  20. Polymer-Oxygen Compatibility Testing: Effect of Oxygen Aging on Ignition and Combustion Properties

    NASA Technical Reports Server (NTRS)

    Waller, Jess M.; Haas, Jon P.; Wilson, D. Bruce; Fries, Joseph (Technical Monitor)

    2000-01-01

    The oxygen compatibility of six polymers used in oxygen service was evaluated after exposure for 48 hours to oxygen pressures ranging from 350 to 6200 kPa (50 to 900 psia), and temperatures ranging from 50 to 250 C (122 to 302 F). Three elastomers were tested: CR rubber (C873-70), FKM fluorocarbon rubber (Viton A), and MPQ silicone rubber (MIL-ZZ-765, Class 2); and three thermoplastics were tested: polyhexamethylene adipamide (Zytel 42), polytetrafluoroethylene (Teflon TFE), and polychlorotrifluoroethylene (Neoflon CTFE M400H). Post-aging changes in mass, dimensions, tensile strength, elongation at break, and durometer hardness were determined. Also, the compression set was determined for the three elastomers. Results show that the properties under investigation were more sensitive to oxygen pressure at low to moderate temperatures, and more sensitive to temperature at low to moderate oxygen pressures. Inspection of the results also suggested that both chain scissioning and cross-linking processes were operative, consistent with heterogeneous oxidation. Attempts are underway to verify conclusively the occurrence of heterogeneous oxidation using a simple modulus profiling technique. Finally, the effect of aging at 620 kpa (90 psia) and 121 C (250 F) on ignition and combustion resistance was determined. As expected, aged polymers were less ignitable and combustible (had higher AlTs and lower heats of combustion). Special attention was given to Neoflon CTFE. More specifically, the effect of process history (compression versus extrusion molding) and percent crystallinity (quick- versus slow-quenched) on the AIT, heat of combustion, and impact sensitivity of Neoflon CTFE was investigated. Results show the AIT, heat of combustion, and impact sensitivity to be essentially independent of Neoflon CTFE process history and structure.

  1. Dynamical and Physical Properties of a Post-Coronal Mass Ejection Current Sheet

    NASA Astrophysics Data System (ADS)

    Ko, Yuan-Kuen; Raymond, John C.; Lin, Jun; Lawrence, Gareth; Li, Jing; Fludra, Andrzej

    2003-09-01

    In the eruptive process of the Kopp-Pneuman type, the closed magnetic field is stretched by the eruption so much that it is usually believed to be ``open'' to infinity. Formation of the current sheet in such a configuration makes it possible for the energy in the coronal magnetic field to quickly convert into thermal and kinetic energies and cause significant observational consequences, such as growing postflare/CME loop system in the corona, separating bright flare ribbons in the chromosphere, and fast ejections of the plasma and the magnetic flux. An eruption on 2002 January 8 provides us a good opportunity to look into these observational signatures of and place constraints on the theories of eruptions. The event started with the expansion of a magnetic arcade over an active region, developed into a coronal mass ejection (CME), and left some thin streamer-like structures with successively growing loop systems beneath them. The plasma outflow and the highly ionized states of the plasma inside these streamer-like structures, as well as the growing loops beneath them, lead us to conclude that these structures are associated with a magnetic reconnection site, namely, the current sheet, of this eruptive process. We combine the data from the Ultraviolet Coronagraph Spectrometer, Large Angle and Spectrometric Coronagraph Experiment, EUV Imaging Telescope, and Coronal Diagnostic Spectrometer on board the Solar and Heliospheric Observatory, as well as from the Mauna Loa Solar Observatory Mark IV K-coronameter, to investigate the morphological and dynamical properties of this event, as well as the physical properties of the current sheet. The velocity and acceleration of the CME reached up to 1800 km s-1 and 1 km s-2, respectively. The acceleration is found to occur mainly at the lower corona (<2.76 Rsolar). The post-CME loop systems showed behaviors of both postflare loops (upward motion with decreasing speed) and soft X-ray giant arches (upward motion with constant

  2. Dynamical and Physical Properties of a Post-Coronal Mass Ejection Current Sheet

    NASA Technical Reports Server (NTRS)

    Ko, Yuan-Kuen; Raymond, John C.; Lin, Jun; Lawrence, Gareth; Li, Jing; Fludra, Andrzej

    2003-01-01

    In the eruptive process of the Kopp-Pneuman type, the closed magnetic field is stretched by the eruption so much that it is usually believed to be " open " to infinity. Formation of the current sheet in such a configuration makes it possible for the energy in the coronal magnetic field to quickly convert into thermal and kinetic energies and cause significant observational consequences, such as growing postflare/CME loop system in the corona, separating bright flare ribbons in the chromosphere, and fast ejections of the plasma and the magnetic flux. An eruption on 2002 January 8 provides us a good opportunity to look into these observational signatures of and place constraints on the theories of eruptions. The event started with the expansion of a magnetic arcade over an active region, developed into a coronal mass ejection (CME), and left some thin streamer-like structures with successively growing loop systems beneath them. The plasma outflow and the highly ionized states of the plasma inside these streamer-like structures, as well as the growing loops beneath them, lead us to conclude that these structures are associated with a magnetic reconnection site, namely, the current sheet, of this eruptive process. We combine the data from the Ultraviolet Coronagraph Spectrometer, Large Angle and Spectrometric Coronagraph Experiment, EUV Imaging Telescope, and Coronal Diagnostic Spectrometer on board the Solar and Heliospheric Observatory, as well is from the Mauna Loa Solar Observatory Mark IV K-coronameter, to investigate the morphological and dynamical properties of this event, as well as the physical properties of the current sheet. The velocity and acceleration of the CME reached up to 1800 km/s and 1 km/sq s, respectively. The acceleration is found to occur mainly at the lower corona (<2.76 Solar Radius). The post-CME loop systems showed behaviors of both postflare loops (upward motion with decreasing speed) and soft X-ray giant arches (upward motion with constant

  3. Dynamical and Physical Properties of a Post-Coronal Mass Ejection Current Sheet

    NASA Technical Reports Server (NTRS)

    Ko, Yuan-Kuen; Raymond, John C.; Lin, Jun; Lawrence, Gareth; Li, Jing; Fludra, Andrzej

    2003-01-01

    In the eruptive process of the Kopp-Pneuman type, the closed magnetic field is stretched by the eruption so much that it is usually believed to be " open " to infinity. Formation of the current sheet in such a configuration makes it possible for the energy in the coronal magnetic field to quickly convert into thermal and kinetic energies and cause significant observational consequences, such as growing postflare/CME loop system in the corona, separating bright flare ribbons in the chromosphere, and fast ejections of the plasma and the magnetic flux. An eruption on 2002 January 8 provides us a good opportunity to look into these observational signatures of and place constraints on the theories of eruptions. The event started with the expansion of a magnetic arcade over an active region, developed into a coronal mass ejection (CME), and left some thin streamer-like structures with successively growing loop systems beneath them. The plasma outflow and the highly ionized states of the plasma inside these streamer-like structures, as well as the growing loops beneath them, lead us to conclude that these structures are associated with a magnetic reconnection site, namely, the current sheet, of this eruptive process. We combine the data from the Ultraviolet Coronagraph Spectrometer, Large Angle and Spectrometric Coronagraph Experiment, EUV Imaging Telescope, and Coronal Diagnostic Spectrometer on board the Solar and Heliospheric Observatory, as well is from the Mauna Loa Solar Observatory Mark IV K-coronameter, to investigate the morphological and dynamical properties of this event, as well as the physical properties of the current sheet. The velocity and acceleration of the CME reached up to 1800 km/s and 1 km/sq s, respectively. The acceleration is found to occur mainly at the lower corona (<2.76 Solar Radius). The post-CME loop systems showed behaviors of both postflare loops (upward motion with decreasing speed) and soft X-ray giant arches (upward motion with constant

  4. Applications and statistical properties of minimum significant difference-based criterion testing in a toxicity testing program

    SciTech Connect

    Wang, Q.; Denton, D.L.; Shukla, R.

    2000-01-01

    As a follow up to the recommendations of the September 1995 SETAC Pellston Workshop on Whole Effluent Toxicity (WET) on test methods and appropriate endpoints, this paper will discuss the applications and statistical properties of using a statistical criterion of minimum significant difference (MSD). The authors examined the upper limits of acceptable MSDs as acceptance criterion in the case of normally distributed data. The implications of this approach are examined in terms of false negative rate as well as false positive rate. Results indicated that the proposed approach has reasonable statistical properties. Reproductive data from short-term chronic WET test with Ceriodaphnia dubia tests were used to demonstrate the applications of the proposed approach. The data were collected by the North Carolina Department of Environment, Health, and Natural Resources (Raleigh, NC, USA) as part of their National Pollutant Discharge Elimination System program.

  5. An Experimental Investigation of Shale Mechanical Properties Through Drained and Undrained Test Mechanisms

    NASA Astrophysics Data System (ADS)

    Islam, Md. Aminul; Skalle, Paal

    2013-11-01

    Shale mechanical properties are evaluated from laboratory tests after a complex workflow that covers tasks from sampling to testing. Due to the heterogeneous nature of shale, it is common to obtain inconsistent test results when evaluating the mechanical properties. In practice, this variation creates errors in numerical modeling when test results differ significantly, even when samples are from a similar core specimen. This is because the fundamental models are based on the supplied test data and a gap is, therefore, always observed during calibration. Thus, the overall goal of this study was to provide additional insight regarding the organization of the non-linear model input parameters in borehole simulations and to assist other researchers involved in the rock physics-related research fields. To achieve this goal, the following parallel activities were carried out: (1) perform triaxial testing with different sample orientations, i.e., 0°, 45°, 60°, and 90°, including the Brazilian test and CT scans, to obtain a reasonably accurate description of the anisotropic properties of shale; (2) apply an accurate interpretative method to evaluate the elastic moduli of shale; (3) evaluate and quantify the mechanical properties of shale by accounting for the beddings plane, variable confinement pressures, drained and undrained test mechanisms, and cyclic versus monotonic test effects. The experimental results indicate that shale has a significant level of heterogeneity. Postfailure analysis confirmed that the failure plane coincides nicely with the weak bedding plane. The drained Poisson’s ratios were, on average, 40 % or lower than the undrained rates. The drained Young’s modulus was approximately 48 % that of the undrained value. These mechanical properties were significantly impacted by the bedding plane orientation. Based on the Brazilian test, the predicted tensile strength perpendicular to the bedding plane was 12 % lower than the value obtained using the

  6. Relation between heart rate recovery after exercise testing and body mass index.

    PubMed

    Barbosa Lins, Tereza Cristina; Valente, Lucila Maria; Sobral Filho, Dário Celestino; Barbosa e Silva, Odwaldo

    2015-01-01

    Impaired heart rate (HR) recovery after exercise testing is considered a predictor of cardiovascular mortality as it reflects vagus nerve dysfunction. To assess the relationship between body mass index (BMI) and HR recovery after exercise. We analyzed the records of 2443 patients of both sexes, aged between 20 and 59 years, in sinus rhythm, not using negative chronotropic agents and with no myocardial ischemic response to exercise testing carried out at a specialist clinic, between 2005 and 2011. BMI was categorized as normal (18.5-<25 kg/m(2)), overweight (25-≤30 kg/m(2)) or obese (>30 kg/m(2)). The different BMI groups were compared in terms of HR recovery after exercise, which was calculated as the difference between maximum HR during exercise and in the first minute of recovery. Recovery was considered impaired when the difference was ≤12 bpm. Eighty-seven (3.6%) patients presented impaired recovery, which was three times more prevalent in the obese group and twice as prevalent in the overweight group compared with the normal group (p<0.001 and p=0.010, respectively). Obese patients presented higher basal HR and lower maximum HR, as well as reduced chronotropic reserve (p<0.001). In multivariate analysis, impaired HR recovery was associated with overweight (relative risk [RR]=1.8; p=0.035), obesity (RR=2; p=0.016), number of metabolic equivalents (RR=0.82; p<0.001) and resting HR (RR=1.05; p<0.001). The hazard ratio for hypertension was 2 (p=0.083, NS). Impaired HR recovery was associated with higher BMI, demonstrating that obese individuals present vagus nerve dysfunction. Copyright © 2014 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

  7. TESTS OF DYNAMICAL FLUX EMERGENCE AS A MECHANISM FOR CORONAL MASS EJECTION INITIATION

    SciTech Connect

    Leake, James E.; Linton, Mark G.; Antiochos, Spiro K. E-mail: mark.linton@nrl.navy.mi

    2010-10-10

    Current coronal mass ejection (CME) models set their lower boundary to be in the lower corona. They do not calculate accurately the transfer of free magnetic energy from the convection zone to the magnetically dominated corona because they model the effects of flux emergence using kinematic boundary conditions or simply assume the appearance of flux at these heights. We test the importance of including dynamical flux emergence in CME modeling by simulating, in 2.5D, the emergence of sub-surface flux tubes into different coronal magnetic field configurations. We investigate how much free magnetic energy, in the form of shear magnetic field, is transported from the convection zone to the corona, and whether dynamical flux emergence can drive CMEs. We find that multiple coronal flux ropes can be formed during flux emergence, and although they carry some shear field into the corona, the majority of shear field is confined to the lower atmosphere. Less than 10% of the magnetic energy in the corona is in the shear field, and this, combined with the fact that the coronal flux ropes bring up significant dense material, means that they do not erupt. Our results have significant implications for all CME models which rely on the transfer of free magnetic energy from the lower atmosphere into the corona but which do not explicitly model this transfer. Such studies of flux emergence and CMEs are timely, as we have new capabilities to observe this with Hinode and the Solar Dynamics Observatory, and therefore to test the models against observations.

  8. Cubical Mass-Spring Model design based on a tensile deformation test and nonlinear material model.

    PubMed

    San-Vicente, Gaizka; Aguinaga, Iker; Tomás Celigüeta, Juan

    2012-02-01

    Mass-Spring Models (MSMs) are used to simulate the mechanical behavior of deformable bodies such as soft tissues in medical applications. Although they are fast to compute, they lack accuracy and their design remains still a great challenge. The major difficulties in building realistic MSMs lie on the spring stiffness estimation and the topology identification. In this work, the mechanical behavior of MSMs under tensile loads is analyzed before studying the spring stiffness estimation. In particular, the performed qualitative and quantitative analysis of the behavior of cubical MSMs shows that they have a nonlinear response similar to hyperelastic material models. According to this behavior, a new method for spring stiffness estimation valid for linear and nonlinear material models is proposed. This method adjusts the stress-strain and compressibility curves to a given reference behavior. The accuracy of the MSMs designed with this method is tested taking as reference some soft-tissue simulations based on nonlinear Finite Element Method (FEM). The obtained results show that MSMs can be designed to realistically model the behavior of hyperelastic materials such as soft tissues and can become an interesting alternative to other approaches such as nonlinear FEM.

  9. Effects of strain rate, test temperature and test environment on tensile properties of vandium alloys

    SciTech Connect

    Gubbi, A.N.; Rowcliffe, A.F.; Eatherly, W.S.; Gibson, L.T.

    1996-10-01

    Tensile testing was carried out on SS-3 tensile specimens punched from 0.762-mm-thick sheets of the large heat of V-4Cr-4Ti and small heats of V-3Cr-3Ti and V-6Cr-6Ti. The tensile specimens were annealed at 1000{degrees} for 2 h to obtain a fully recrystallized, fine grain microstructure with a grain size in the range of 10-19 {mu}m. Room temperature tests at strain rates ranging from 10{sup {minus}3} to 5 x 10{sup {minus}1}/s were carried out in air; elevated temperature testing up to 700{degrees}C was conducted in a vacuum better than 1 x 10{sup {minus}5} torr (<10{sup {minus}3} Pa). To study the effect of atomic hydrogen on ductility, tensile tests were conducted at room temperature in an ultra high vacuum chamber (UHV) with a hydrogen leak system.

  10. A comparison of solar energetic particle event timescales with properties of associated coronal mass ejections

    SciTech Connect

    Kahler, S. W.

    2013-06-01

    The dependence of solar energetic proton (SEP) event peak intensities Ip on properties of associated coronal mass ejections (CMEs) has been extensively examined, but the dependence of SEP event timescales is not well known. We define three timescales of 20 MeV SEP events and ask how they are related to speeds v {sub CME} or widths W of their associated CMEs observed by LASCO/SOHO. The timescales of the EPACT/Wind 20 MeV events are TO, the onset time from CME launch to SEP onset; TR, the rise time from onset to half the peak intensity (0.5Ip); and TD, the duration of the SEP intensity above 0.5Ip. This is a statistical study based on 217 SEP-CME events observed during 1996-2008. The large number of SEP events allows us to examine the SEP-CME relationship in five solar-source longitude ranges. In general, we statistically find that TO declines slightly with v {sub CME}, and TR and TD increase with both v {sub CME} and W. TO is inversely correlated with log Ip, as expected from a particle background effect. We discuss the implications of this result and find that a background-independent parameter TO+TR also increases with v {sub CME} and W. The correlations generally fall below the 98% significance level, but there is a significant correlation between v {sub CME} and W which renders interpretation of the timescale results uncertain. We suggest that faster (and wider) CMEs drive shocks and accelerate SEPs over longer times to produce the longer TR and TD SEP timescales.

  11. Optical Properties of High Area-to-Mass Objects at GEO

    NASA Technical Reports Server (NTRS)

    Seitzer, Patrick; Schildknecht, Thomas; Musci, Reto; Flohrer, Tim; Barker, Ed; Stansbery, Eugene; Agapov, Vladimir; Rumyantsev, Vasilij; Biryukov, Vadym; Abercromby, Kira; hide

    2007-01-01

    There exists at GEO a significant population of faint debris (R > 15th magnitude) with high area-to-mass ratios (AMR) (1 to 30 sq m/kg). Their orbital elements (particularly eccentricity and inclination) are observed to change on the time-scale of a week. The consensus is that these objects may be fragments of multi-layer insulation (MLI) blankets. Their orbits are primarily perturbed by solar radiation pressure. In this paper we will report preliminary results from an international collaboration to investigate the unresolved optical properties of these objects. This population was originally discovered by the ESA Space Debris Telescope, and the bulk of the objects to be described here are based on discoveries made with this telescope. Additional objects were supplied by both Russia and the US Air Force. Follow-up optical observations were obtained for a sample of a dozen objects by MODEST (the Michigan Orbital DEbris Survey Telescope) located at Cerro Tololo Inter-American Observatory in Chile. Sequences of calibrated observations in filters B, V, Broad R, and I were obtained under photometric conditions. Multi-color photometric observations in B, V, R, and I band of the same objects were also acquired at the Zimmerwald 1-meter telescope, located near Bern, Switzerland. Light curves of selected high AMR objects will be shown with a temporal resolution of a few seconds and typically span about 10 minutes. Photometric observations of these objects were acquired at the Crimean Astrophysical Observatory (CrAO). This data set includes light curves of objects having high variability of brightness and observed with 2.6 m and 0.64 m class instruments. We will present an analysis of the observed magnitudes and colors, and their correlations (or lack of correlation) with orbital elements, and with predicted values for MLI fragments. This represents the first such collaborative observational program on faint debris at GEO.

  12. A Comparison of Solar Energetic Particle Event Timescales with Properties of Associated Coronal Mass Ejections

    NASA Astrophysics Data System (ADS)

    Kahler, S. W.

    2013-06-01

    The dependence of solar energetic proton (SEP) event peak intensities Ip on properties of associated coronal mass ejections (CMEs) has been extensively examined, but the dependence of SEP event timescales is not well known. We define three timescales of 20 MeV SEP events and ask how they are related to speeds v CME or widths W of their associated CMEs observed by LASCO/SOHO. The timescales of the EPACT/Wind 20 MeV events are TO, the onset time from CME launch to SEP onset; TR, the rise time from onset to half the peak intensity (0.5Ip); and TD, the duration of the SEP intensity above 0.5Ip. This is a statistical study based on 217 SEP-CME events observed during 1996-2008. The large number of SEP events allows us to examine the SEP-CME relationship in five solar-source longitude ranges. In general, we statistically find that TO declines slightly with v CME, and TR and TD increase with both v CME and W. TO is inversely correlated with log Ip, as expected from a particle background effect. We discuss the implications of this result and find that a background-independent parameter TO+TR also increases with v CME and W. The correlations generally fall below the 98% significance level, but there is a significant correlation between v CME and W which renders interpretation of the timescale results uncertain. We suggest that faster (and wider) CMEs drive shocks and accelerate SEPs over longer times to produce the longer TR and TD SEP timescales.

  13. Mass spectrometry assay for studying kinetic properties of dipeptidases: characterization of human and yeast dipeptidases.

    PubMed

    Pandya, Vaibhav; Ekka, Mary Krishna; Dutta, Rajesh Kumar; Kumaran, S

    2011-11-01

    Chemical modifications of substrate peptides are often necessary to monitor the hydrolysis of small bioactive peptides. We developed an electrospray ionization mass spectrometry (ESI-MS) assay for studying substrate distributions in reaction mixtures and determined steady-state kinetic parameters, the Michaelis-Menten constant (K(m)), and catalytic turnover rate (V(max)/[E](t)) for three metallodipeptidases: two carnosinases (CN1 and CN2) from human and Dug1p from yeast. The turnover rate (V(max)/[E](t)) of CN1 and CN2 determined at pH 8.0 (112.3 and 19.5s(-1), respectively) suggested that CN1 is approximately 6-fold more efficient. The turnover rate of Dug1p for Cys-Gly dipeptide at pH 8.0 was found to be slightly lower (73.8s(-1)). In addition, we determined kinetic parameters of CN2 at pH 9.2 and found that the turnover rate was increased by 4-fold with no significant change in the K(m). Kinetic parameters obtained by the ESI-MS method are consistent with results of a reverse-phase high-performance liquid chromatography (RP-HPLC)-based assay. Furthermore, we used tandem MS (MS/MS) analyses to characterize carnosine and measured its levels in CHO cell lines in a time-dependent manner. The ESI-MS method developed here obviates the need for substrate modification and provides a less laborious, accurate, and rapid assay for studying kinetic properties of dipeptidases in vitro as well as in vivo. Copyright © 2011 Elsevier Inc. All rights reserved.

  14. Overview of aerosol properties associated with air masses sampled by the ATR-42 during the EUCAARI campaign (2008)

    NASA Astrophysics Data System (ADS)

    Crumeyrolle, S.; Schwarzenboeck, A.; Sellegri, K.; Burkhart, J. F.; Stohl, A.; Gomes, L.; Quennehen, B.; Roberts, G.; Weigel, R.; Roger, J. C.; Villani, P.; Pichon, J. M.; Bourrianne, T.; Laj, P.

    2012-04-01

    Within the frame of the European Aerosol Cloud Climate and Air Quality Interactions (EUCAARI) project the Météo-France aircraft ATR-42 performed 22 research flights, over central Europe and the North Sea during the intensive observation period in May 2008. For the campaign, the ATR-42 was equipped in order to study aerosol physical, chemical and optical properties, as well as cloud microphysics. During the campaign, continental air masses from Eastern and Western Europe were encountered, along with polar and Scandinavian air masses. For the 22 research flights, retroplume analyses along the flight tracks were performed with FLEXPART in order to classify air masses into five sectors of origin which allows for a qualitative evaluation of emission influence on the respective air parcel. In the polluted boundary layer (BL), typical concentrations of particles with diameters larger than 10 nm (N10) are of the order of 5000-6000 cm-3, whereas N10 concentrations of clean air masses were lower than 1300 cm-3. The detection of the largest particle number concentrations occurred in air masses coming from Polar and Scandinavian regions for which an elevated number of nucleation mode (25-28 nm) particles was observed and attributed to new particle formation over open sea. In the free troposphere (FT), typical observed N10 are of the order of 900 cm-3 in polluted air masses and 400-600 cm-3 in clean air masses, respectively. In both layers, the chemical composition of submicron aerosol particles is dominated by organic matter and nitrate in polluted air masses, while, sulphate and ammonium followed by organics dominate the submicron aerosols in clean air masses. The highest CCN/CN ratios were observed within the polar air masses while the CCN concentration values are the highest within the polluted air masses. Within the five air mass sectors defined and the two layers (BL and FT), observations have been distinguished into anticyclonic (first half of May 2008) and cyclonic

  15. Development of small punch testing technique and its application to evaluation of mechanical properties degradation

    SciTech Connect

    Kameda, J.

    1993-10-01

    The present paper summarizes a small punch (SP) testing technique developed and its application to mechanical properties characterization. It has been clearly shown on ferritic alloys that the SP test was evaluate the intergranular embrittling potency of segregated solute, such as P, Sn and Sb causing temper embrittlement, and the effects of neutron irradiation and post-irradiation annealing, giving rise to changes in the hardness and intergranular solute segregation, on the fracture properties in terms of the ductile-brittle transition temperature (DBTT). A linear relation of the DBTT determined by the SP test to that by Charpy V-notched tests has been theoretically and experimentally established. In Al alloy substrates coated with amorphous and overlaying ceramics, moreover, the global and local fracture properties were well characterized by the SP test together with acoustic emission techniques.

  16. Analysis of three-point-bend test for materials with unequal tension and compression properties

    NASA Technical Reports Server (NTRS)

    Chamis, C. C.

    1974-01-01

    An analysis capability is described for the three-point-bend test applicable to materials of linear but unequal tensile and compressive stress-strain relations. The capability consists of numerous equations of simple form and their graphical representation. Procedures are described to examine the local stress concentrations and failure modes initiation. Examples are given to illustrate the usefulness and ease of application of the capability. Comparisons are made with materials which have equal tensile and compressive properties. The results indicate possible underestimates for flexural modulus or strength ranging from 25 to 50 percent greater than values predicted when accounting for unequal properties. The capability can also be used to reduce test data from three-point-bending tests, extract material properties useful in design from these test data, select test specimen dimensions, and size structural members.

  17. Application of the Split Hopkinson Resonant Bar Test for Seismic Property Characterization of Hydrate-bearing Sand Undergoing Water Saturation

    SciTech Connect

    Nakagawa, S.; Kneafsey, T.J.

    2011-05-03

    Conventional resonant bar tests allow the measurement of seismic properties of rocks and sediments at low frequencies (several kilohertz). However, the tests require a long, slender sample which is often difficult to obtain from the deep subsurface and weak and fractured formations. We present an alternative low-frequency measurement technique to the conventional resonant bar tests. This technique involves a jacketed core sample placed between a pair of long, metal extension rods with attached seismic source and receiver—the same geometry as the split Hopkinson pressure bar test for large-strain, dynamic impact experiments. Because of the added length and mass to the sample, the resonance frequency of the entire system can be lowered significantly, compared to the sample alone. The proposed “Split Hopkinson Resonant Bar (SHRB)” test is applied in two steps. In the first step, extension and torsion-mode resonance frequencies and attenuation of the system are measured. Then, numerical inversions for the compressional and shear wave velocities and attenuation are performed. We initially applied the SHRB test to synthetic materials (plastics) for testing its accuracy, then used it for measuring the seismic velocities and attenuation of a rock core containing supercritical CO{sub 2}, and a sediment core while methane hydrate formed in the pore space.

  18. Testing multimass dynamical models of star clusters with real data: mass segregation in three Galactic globular clusters

    NASA Astrophysics Data System (ADS)

    Sollima, A.; Dalessandro, E.; Beccari, G.; Pallanca, C.

    2017-02-01

    We present the results of the analysis of deep photometric data for a sample of three Galactic globular clusters (NGC5466, NGC6218 and NGC 6981) with the aim of estimating their degree of mass segregation and testing the predictions of analytic dynamical models. The adopted data set, composed of both Hubble Space Telescope and ground-based data, reaches the low-mass end of the mass functions of these clusters from the centre up to their tidal radii allowing us to derive the radial distribution of stars with different masses. All the analysed clusters show evidence of mass segregation with the most massive stars being more concentrated than the low-mass ones. The structures of NGC5466 and NGC6981 are well reproduced by multimass dynamical models adopting a lowered Maxwellian distribution function and the prescription for mass segregation given by Gunn & Griffin. Instead, NGC6218 appears to be more mass segregated than model predictions. By applying the same technique to mock observations derived from snapshots selected from suitable N-body simulations, we show that the deviation from the behaviour predicted by these models depends on the particular stage of dynamical evolution regardless of initial conditions.

  19. Test methods for the dynamic mechanical properties of polymeric materials. Final report

    SciTech Connect

    Baker, G.K.

    1980-06-01

    Various test geometries and procedures for the dynamic mechanical analysis of polymers employing a mechanical spectrometer have been evaluated. The methods and materials included in this work are forced torsional pendulum testing of Kevlar/epoxy laminates and rigid urethane foams, oscillatory parallel plate testing to determine the kinetics of the cure of VCE with Hylene MP, oscillatory compressive testing of B-3223 cellular silicone, and oscillatory tensile testing of Silastic E and single Kevlar filaments. Fundamental dynamic mechanical properties, including the storage and loss moduli and loss tangent of the materials tested, were determined as a function of temperature and sometimes of frequency.

  20. Properties of mass-loading shocks. II - Magnetohydrodynamics. [of Giacobini-Zinner and Halley comets

    NASA Technical Reports Server (NTRS)

    Zank, G. P.; Oughton, S.; Neubauer, F. M.; Webb, G. M.

    1992-01-01

    The one-dimensional magnetohydrodynamics of mass-loading shocks is examined. These shocks, which are distinct from MHD shocks of classical nonreacting fluid dynamics and of combustion theory and which are characterized by the addition of mass within the shock transition, are to be found at comets and, depending upon circumstances, at nonmagnetized and weakly magnetized planets such as Venus and Mars. A completely general mass-loading form of the Hugoniot equation is derived, and some of the most important differences between mass-loading and nonreacting classical MHD shocks are identified. Two new types of MHD shocks are described which have no classical MHD analogues.

  1. Biomechanical properties of the mid-shaft femur in middle-aged hypophysectomized rats as assessed by bending test.

    PubMed

    Bozzini, Clarisa; Picasso, Emilio O; Champin, Graciela M; Alippi, Rosa María; Bozzini, Carlos E

    2012-10-01

    Both stiffness and strength of bones are thought to be controlled by the "bone mechanostat". Its natural stimuli would be the strains of bone tissue (sensed by osteocytes) that are induced by both gravitational forces (body weight) and contraction of regional muscles. Body weight and muscle mass increase with age. Biomechanical performance of load-bearing bones must adapt to these growth-induced changes. Hypophysectomy in the rat slows the rate of body growth. With time, a great difference in body size is established between a hypophysectomized rat and its age-matched control, which makes it difficult to establish the real effect of pituitary ablation on bone biomechanics. The purpose of the present investigation was to compare mid-shaft femoral mechanical properties between hypophysectomized and weight-matched normal rats, which will show similar sizes and thus will be exposed to similar habitual loads. Two groups of 10 female rats each (H and C) were established. H rats were 12-month-old that had been hypophysectomized 11 months before. C rats were 2.5-month-old normals. Right femur mechanical properties were tested in 3-point bending. Structural (load-bearing capacity and stiffness), geometric (cross-sectional area, cortical sectional area, and moment of inertia), and material (modulus of elasticity and maximum elastic stress) properties were evaluated. The left femur was ashed for calcium content. Comparisons between parameters were performed by the Student's t test. Average body weight, body length, femur weight, femur length, and gastrocnemius weight were not significantly different between H and C rats. Calcium content in ashes was significantly higher in H than in C rats. Cross-sectional area, medullary area, and cross-sectional moment of inertia were higher in C rats, whereas cortical area did not differ between groups. Structural properties (diaphyseal stiffness, elastic limit, and load at fracture) were about four times higher in hypophysectomized rats

  2. Neutrino mass

    SciTech Connect

    Robertson, R.G.H.

    1992-01-01

    Despite intensive experimental work since the neutrino's existence was proposed by Pauli 60 years ago, and its first observation by Reines and Cowan almost 40 years ago, the neutrino's fundamental properties remain elusive. Among those properties are the masses of the three known flavors, properties under charge conjugation, parity and time-reversal, and static and dynamic electromagnetic moments. Mass is perhaps the most fundamental, as it constrains the other properties. The present status of the search for neutrino mass is briefly reviewed.

  3. Cyclic Material Properties Test to Determine Hardening/Softening Characteristics of HY-80 Steel

    SciTech Connect

    S.C. Hodge; J.M. Minicucci; T.F. Trimble

    2003-04-30

    The Cyclic Material Properties Test was structured to obtain and provide experimental data for determining cyclic hardening/softening characteristics of HY-80 steel. The inelastic strain history data generated by this test program and the resulting cyclic stress-strain curve will be used to enhance material models in the finite element codes used to perform nonlinear elastic-plastic analysis.

  4. Indentation testing and optimized property identification for viscoelastic materials using the finite element method

    NASA Astrophysics Data System (ADS)

    Resapu, Rajeswara Reddy

    The most common approaches to determining mechanical material properties of materials are tension and compression tests. However, tension and compression testing cannot be implemented under certain loading conditions (immovable object, not enough space to hold object for testing, etc). Similarly, tensile and compression testing cannot be performed on certain types of materials (delicate, bulk, non-machinable, those that cannot be separated from a larger structure, etc). For such cases, other material testing methods need to be implemented. Indentation testing is one such method; this approach is often non-destructive and can be used to characterize regions that are not compatible with other testing methods. However, indentation testing typically leads to force-displacement data as opposed to the direct stress-strain data normally used for the mechanical characterization of materials; this data needs to be analyzed using a suitable approach to determine the associated material properties. As such, methods to establish material properties from force-displacement indentation data need to be identified. In this work, a finite element approach using parameter optimization is developed to determine the mechanical properties from the experimental indentation data. Polymers and tissues tend to have time-dependent mechanical behavior; this means that their mechanical response under load changes with time. This dissertation seeks to characterize the properties of these materials using indentation testing under the assumption that they are linear viscoelastic. An example of a material of interest is the polymer poly vinyl chloride (PVC) that is used as the insulation of some aircraft wiring. Changes in the mechanical properties of this material over years of service can indicate degradation and a potential hazard to continued use. To investigate the validity of using indentation testing to monitor polymer insulation degradation, PVC film and PVC-insulated aircraft wiring are

  5. Determining Seed Cotton Mass Flow Rate by Pressure Drop Across a Blowbox: Gin Testing

    USDA-ARS?s Scientific Manuscript database

    Accurate measurement of the mass flow rate of seed cotton is needed for control and monitoring purposes in gins. A system was developed that accurately predicted mass flow rate based on the static pressure drop measured across the blowbox and the air velocity and temperature entering the blowbox. Ho...

  6. Testing the Reliability of Cluster Mass Indicators with a Systematics Limited Dataset

    NASA Technical Reports Server (NTRS)

    Juett, Adrienne M.; Davis, David S.; Mushotzky, Richard

    2009-01-01

    We present the mass X-ray observable scaling relationships for clusters of galaxies using the XMM-Newton cluster catalog of Snowden et al. Our results are roughly consistent with previous observational and theoretical work, with one major exception. We find 2-3 times the scatter around the best fit mass scaling relationships as expected from cluster simulations or seen in other observational studies. We suggest that this is a consequence of using hydrostatic mass, as opposed to virial mass, and is due to the explicit dependence of the hydrostatic mass on the gradients of the temperature and gas density profiles. We find a larger range of slope in the cluster temperature profiles at radii 500 than previous observational studies. Additionally, we find only a weak dependence of the gas mass fraction on cluster mass, consistent with a constant. Our average gas mass fraction results also argue for a closer study of the systematic errors due to instrumental calibration and modeling method variations between analyses. We suggest that a more careful study of the differences between various observational results and with cluster simulations is needed to understand sources of bias and scatter in cosmological studies of galaxy clusters.

  7. Determining Seed Cotton Mass Flow Rate by Pressure Drop Across the Blowbox: Gin Testing

    USDA-ARS?s Scientific Manuscript database

    Accurate measurement of the mass flow rate of seed cotton is needed for control and monitoring purposes in gins. A system was developed that accurately predicted mass flow rate based on the static pressure drop measured across the blowbox and the air velocity and temperature entering the blowbox usi...

  8. Testing the Reliability of Cluster Mass Indicators with XMM High to Noise Observations

    NASA Astrophysics Data System (ADS)

    Mushotzky, Richard; Juett, A. M.; Davis, D.

    2010-01-01

    We present the mass-X-ray observable scaling relationships for clusters of galaxies using the XMM-Newton cluster catalog of Snowden et al.. Our results are roughly consistent with previous observational and theoretical work, with one major exception. We find 2-3 times the scatter around the best fit mass scaling relationships as expected from cluster simulations or seen in other observational studies. We suggest that this is a consequence of using hydrostatic mass, as opposed to virial mass, and is due to the explicit dependence of the hydrostatic mass on the gradients of the temperature and gas density profiles. We find a larger range of slope in the cluster temperature profiles at r500 than previous observational studies. Additionally, we find a weak dependence of the gas mass fraction on cluster mass, consistent with a constant. Our average gas mass fraction results also argue for a closer study of the systematic errors due to instrumental calibration and modeling method variations between analyses.

  9. Testing the Reliability of Cluster Mass Indicators with a Systematics Limited Data Set

    NASA Astrophysics Data System (ADS)

    Juett, Adrienne M.; Davis, David S.; Mushotzky, Richard

    2010-02-01

    We present the mass-X-ray observable scaling relationships for clusters of galaxies using the XMM-Newton cluster catalog of Snowden et al. Our results are roughly consistent with previous observational and theoretical work, with one major exception. We find two to three times the scatter around the best-fit mass scaling relationships as expected from cluster simulations or seen in other observational studies. We suggest that this is a consequence of using hydrostatic mass, as opposed to virial mass, and is due to the explicit dependence of the hydrostatic mass on the gradients of the temperature and gas density profiles. We find a larger range of slope in the cluster temperature profiles at r 500 than previous observational studies. Additionally, we find only a weak dependence of the gas mass fraction on cluster mass, consistent with a constant. Our average gas mass fraction results argue for a closer study of the systematic errors due to instrumental calibration and analysis method variations. We suggest that a more careful study of the differences between various observational results and with cluster simulations is needed to understand sources of bias and scatter in cosmological studies of galaxy clusters.

  10. Mass Balance. Operational Control Tests for Wastewater Treatment Facilities. Instructor's Manual [and] Student Workbook.

    ERIC Educational Resources Information Center

    Carnegie, John W.

    This module describes the process used to determine solids mass and location throughout a waste water treatment plant, explains how these values are used to determine the solids mass balance around single treatment units and the entire system, and presents calculations of solids in pounds and sludge units. The instructor's manual contains a…

  11. Numerical test concerning bone mass apposition under electrical and mechanical stimulus

    PubMed Central

    2012-01-01

    This article proposes a model of bone remodeling that encompasses mechanical and electrical stimuli. The remodeling formulation proposed by Weinans and collaborators was used as the basis of this research, with a literature review allowing a constitutive model evaluating the permittivity of bone tissue to be developed. This allowed the mass distribution that depends on mechanical and electrical stimuli to be obtained. The remaining constants were established through numerical experimentation. The results demonstrate that mass distribution is altered under electrical stimulation, generally resulting in a greater deposition of mass. In addition, the frequency of application of an electric field can affect the distribution of mass; at a lower frequency there is more mass in the domain. These numerical experiments open up discussion concerning the importance of the electric field in the remodeling process and propose the quantification of their effects. PMID:22578031

  12. Numerical test concerning bone mass apposition under electrical and mechanical stimulus.

    PubMed

    Garzón-Alvarado, Diego A; Ramírez-Martínez, Angélica M; Cardozo de Martínez, Carmen Alicia

    2012-05-11

    This article proposes a model of bone remodeling that encompasses mechanical and electrical stimuli. The remodeling formulation proposed by Weinans and collaborators was used as the basis of this research, with a literature review allowing a constitutive model evaluating the permittivity of bone tissue to be developed. This allowed the mass distribution that depends on mechanical and electrical stimuli to be obtained. The remaining constants were established through numerical experimentation. The results demonstrate that mass distribution is altered under electrical stimulation, generally resulting in a greater deposition of mass. In addition, the frequency of application of an electric field can affect the distribution of mass; at a lower frequency there is more mass in the domain. These numerical experiments open up discussion concerning the importance of the electric field in the remodeling process and propose the quantification of their effects.

  13. The ELM Survey. VII. Orbital Properties of Low-Mass White Dwarf Binaries

    NASA Astrophysics Data System (ADS)

    Brown, Warren R.; Gianninas, A.; Kilic, Mukremin; Kenyon, Scott J.; Allende Prieto, Carlos

    2016-02-01

    We present the discovery of 15 extremely low-mass (5\\lt {log}g\\lt 7) white dwarf (WD) candidates, 9 of which are in ultra-compact double-degenerate binaries. Our targeted extremely low-mass Survey sample now includes 76 binaries. The sample has a lognormal distribution of orbital periods with a median period of 5.4 hr. The velocity amplitudes imply that the binary companions have a normal distribution of mass with 0.76 M⊙ mean and 0.25 M⊙ dispersion. Thus extremely low-mass WDs are found in binaries with a typical mass ratio of 1:4. Statistically speaking, 95% of the WD binaries have a total mass below the Chandrasekhar mass, and thus are not type Ia supernova progenitors. Yet half of the observed binaries will merge in less than 6 Gyr due to gravitational wave radiation; probable outcomes include single massive WDs and stable mass transfer AM CVn binaries. Based on observations obtained at the MMT Observatory, a joint facility of the Smithsonian Institution and the University of Arizona.

  14. Testing Students with Special Educational Needs in Large-Scale Assessments – Psychometric Properties of Test Scores and Associations with Test Taking Behavior

    PubMed Central

    Pohl, Steffi; Südkamp, Anna; Hardt, Katinka; Carstensen, Claus H.; Weinert, Sabine

    2016-01-01

    Assessing competencies of students with special educational needs in learning (SEN-L) poses a challenge for large-scale assessments (LSAs). For students with SEN-L, the available competence tests may fail to yield test scores of high psychometric quality, which are—at the same time—measurement invariant to test scores of general education students. We investigated whether we can identify a subgroup of students with SEN-L, for which measurement invariant competence measures of adequate psychometric quality may be obtained with tests available in LSAs. We furthermore investigated whether differences in test-taking behavior may explain dissatisfying psychometric properties and measurement non-invariance of test scores within LSAs. We relied on person fit indices and mixture distribution models to identify students with SEN-L for whom test scores with satisfactory psychometric properties and measurement invariance may be obtained. We also captured differences in test-taking behavior related to guessing and missing responses. As a result we identified a subgroup of students with SEN-L for whom competence scores of adequate psychometric quality that are measurement invariant to those of general education students were obtained. Concerning test taking behavior, there was a small number of students who unsystematically picked response options. Removing these students from the sample slightly improved item fit. Furthermore, two different patterns of missing responses were identified that explain to some extent problems in the assessments of students with SEN-L. PMID:26941665

  15. Testing Students with Special Educational Needs in Large-Scale Assessments - Psychometric Properties of Test Scores and Associations with Test Taking Behavior.

    PubMed

    Pohl, Steffi; Südkamp, Anna; Hardt, Katinka; Carstensen, Claus H; Weinert, Sabine

    2016-01-01

    Assessing competencies of students with special educational needs in learning (SEN-L) poses a challenge for large-scale assessments (LSAs). For students with SEN-L, the available competence tests may fail to yield test scores of high psychometric quality, which are-at the same time-measurement invariant to test scores of general education students. We investigated whether we can identify a subgroup of students with SEN-L, for which measurement invariant competence measures of adequate psychometric quality may be obtained with tests available in LSAs. We furthermore investigated whether differences in test-taking behavior may explain dissatisfying psychometric properties and measurement non-invariance of test scores within LSAs. We relied on person fit indices and mixture distribution models to identify students with SEN-L for whom test scores with satisfactory psychometric properties and measurement invariance may be obtained. We also captured differences in test-taking behavior related to guessing and missing responses. As a result we identified a subgroup of students with SEN-L for whom competence scores of adequate psychometric quality that are measurement invariant to those of general education students were obtained. Concerning test taking behavior, there was a small number of students who unsystematically picked response options. Removing these students from the sample slightly improved item fit. Furthermore, two different patterns of missing responses were identified that explain to some extent problems in the assessments of students with SEN-L.

  16. Intrinsic tensile properties of cocoon silk fibres can be estimated by removing flaws through repeated tensile tests

    PubMed Central

    Rajkhowa, Rangam; Kaur, Jasjeet; Wang, Xungai; Batchelor, Warren

    2015-01-01

    Silk fibres from silkworm cocoons have lower strength than spider silk and have received less attention as a source of high-performance fibres. In this work, we have used an innovative procedure to eliminate the flaws gradually of a single fibre specimen by retesting the unbroken portion of the fibre, after each fracture test. This was done multiple times so that the final test may provide the intrinsic fibre strength. During each retest, the fibre specimen began to yield once the failure load of the preceding test was exceeded. For each fibre specimen, a composite curve was constructed from multiple tests. The composite curves and analysis show that strengths of mass-produced Muga and Eri cocoon silk fibres increased from 446 to 618 MPa and from 337 to 452 MPa, respectively. Similarly, their toughness increased from 84 to 136 MJ m−3 and from 61 to 104 MJ m−3, respectively. Composite plots produced significantly less inter-specimen variations compared to values from single tests. The fibres with reduced flaws as a result of retests in the tested section have a tensile strength and toughness comparable to naturally spun dragline spider silk with a reported strength of 574 MPa and toughness of 91–158 MJ m−3, which is used as a benchmark for developing high-performance fibres. This retesting approach is likely to provide useful insights into discrete flaw distributions and intrinsic mechanical properties of other fatigue-resistant materials. PMID:25948613

  17. On the stability of the fragments and associated properties at the peak center-of-mass energy of light fragments

    SciTech Connect

    Bansal, Preeti

    2016-05-06

    We simulate semi-central symmetric system reactions, for center-of-mass energies at which maximal number of light fragments (2 ≤ A ≤ 4) occurs and at a fixed E{sub c.m.} = 60 AMeV. The study was carried out with soft EOS using isospin-dependent quantum molecular dynamics (IQMD) model. We studied various properties of fragments at peak E{sub c.m.} and also at constant energy (E{sub c.m.} = 60 AMeV) to find out the relative difference between the properties at both energies.

  18. Windows-based guided data capture software for mass-scale thermophysical and thermochemical property data collection.

    PubMed

    Diky, Vladimir V; Chirico, Robert D; Wilhoit, Randolph C; Dong, Qian; Frenkel, Michael

    2003-01-01

    Guided data capture software (GDC) is described for mass-scale abstraction from the literature of experimental thermophysical and thermochemical property data for organic chemical systems involving one, two, and three components, chemical reactions, and chemical equilibria. Property values are captured with a strictly hierarchical system based upon rigorous application of the thermodynamic constraints of the Gibbs phase rule with full traceability to source documents. Key features of the program and its adherence to scientific principles are described with particular emphasis on data-quality issues, both in terms of data accuracy and database integrity.

  19. Structure and properties of the egg mass of the ommastrephid squid Todarodes pacificus

    PubMed Central

    Puneeta, Pandey; Yamamoto, Jun; Adachi, Kohsuke; Kato, Yoshiki; Sakurai, Yasunori

    2017-01-01

    The Japanese flying squid, Todarodes pacificus, is thought to spawn neutrally buoyant egg masses that retain a specific location in the water column by floating at the interface between water layers of slightly different densities. It is important to understand the physical process that determines the vertical distribution of the egg masses to predict their horizontal drift in relation to embryo survival and subsequent recruitment. Here, mesocosm experiments were conducted in a 300 m3 tank by creating a thermally stratified (17–22°C) water column to obtain egg masses. A cage net methodology was developed to sustain egg masses for detailed observation. We measured the density of the egg masses of T. pacificus, and used this information to infer the vertical distribution patterns of the egg masses at the spawning grounds (Tsushima Strait, Japan). When measured separately, the density of the outer jelly of each egg mass was 2.7 σ units higher than that of the surrounding water. The outer jelly and the specific gravity of embedded individual eggs (~1.10) cause the egg masses to have very slight negative buoyancy relative to the water in which they are formed. Analysis of the vertical profile of the spawning ground showed that water density (σθ) increased sharply at ~30 m depth; thus, egg masses might settle above the pycnocline layer. In conclusion, we suggest that T. pacificus egg masses might retain their location in the water column by floating at the interface between water layers of slightly different densities, which happen to be above the pycnocline layer (actual depth varies seasonally/annually) in the Tsushima Strait between Korea and Japan. PMID:28767686

  20. Installation of a Devonian Shale Reservoir Testing Facility and acquisition of reservoir property measurements. Final report

    SciTech Connect

    Locke, C.D.; Salamy, S.P.

    1991-09-01

    In October, a contract was awarded for the Installation of a Devonian Shale Reservoir Testing Facility and Acquisition of Reservoir Property measurements from wells in the Michigan, Illinois, and Appalachian Basins. Geologic and engineering data collected through this project will provide a better understanding of the mechanisms and conditions controlling shale gas production. This report summarizes the results obtained from the various testing procedures used at each wellsite and the activities conducted at the Reservoir Testing Facility.

  1. Installation of a Devonian Shale Reservoir Testing Facility and acquisition of reservoir property measurements

    SciTech Connect

    Locke, C.D.; Salamy, S.P.

    1991-09-01

    In October, a contract was awarded for the Installation of a Devonian Shale Reservoir Testing Facility and Acquisition of Reservoir Property measurements from wells in the Michigan, Illinois, and Appalachian Basins. Geologic and engineering data collected through this project will provide a better understanding of the mechanisms and conditions controlling shale gas production. This report summarizes the results obtained from the various testing procedures used at each wellsite and the activities conducted at the Reservoir Testing Facility.

  2. Entanglement properties of kaons and tests of hidden-variable models

    SciTech Connect

    Genovese, M.

    2004-02-01

    In this paper we discuss entanglement properties of neutral kaons systems and their use for testing local realism. In particular, we analyze a Hardy-type scheme [A. Bramon and G. Garbarino, Phys. Rev. Lett. 89, 160401 (2002)] recently suggested for performing a test of hidden-variable theories against standard quantum mechanics. Our result is that this scheme could, in principle, lead to a conclusive test of local realism, but only if higher identification efficiencies than in today's experiments will be reached.

  3. ITER Model Coil Tests Overview: Nb3Sn Strand Properties in Cable-in-Conduit-Conductors

    SciTech Connect

    Martovetsky, N N

    2003-04-14

    During the ITER Model Coil Program two large coils and three Insert coils were built and tested. The test campaigns provided very valuable data on the Conductor in Conduit Cable (CICC) properties. The tests showed that the Nb3Sn strands in CICC behave differently than so-called witness strands, which underwent the same heat treatment. The paper describes Volt-temperature characteristics (VTC) and Volt-Ampere characteristics (VAC) measured in the tests, presents comparisons with the witness strands, and interprets the test results.

  4. Exploring Mass Flux Response to Local Source Zone Properties Using a Coupled-Process Adjoint Sensitivity Method

    NASA Astrophysics Data System (ADS)

    Tang, T.; Miller, E. L.; Abriola, L. M.

    2016-12-01

    Contaminant plumes emanating from DNAPL source zones pose substantial risks to the general population by transporting pollutants to receptor points. Thus, to assess potential risk, the quantification of down gradient mass flux and mass discharge has been identified as a critical component of source zone characterization. These metrics, however, are difficult to measure directly and are typically controlled by the complex interplay of a number of transport mechanisms. In an effort to improve the accuracy and efficiency of site characterization, this work employs an adjoint sensitivity method to quantify the importance of local system properties, given some initial site characterization information, on down gradient mass flux and plume persistence. Local properties that are considered in this research include: permeability, DNAPL saturation, and dissolved and sorbed contaminant mass concentrations. The utility of the adjoint sensitivity method is examined using, numerically generated, 3D heterogeneous DNAPL source zones. Conditioned spatial distributions of the four properties are generated using a joint probabilistic model associated with texture simulations based on field borehole measurements. An existing modular three-dimensional transport simulator, MT3DMS, is applied to solve the transport equation considering both DNAPL dissolution and linear and rate-limited sorption. Consistent with this process coupling, a subroutine is added to the code to solve the adjoint states, which evolves backward in time. Sensitivity analyses are developed to investigate the down-gradient plume response to the perturbation of the four local system properties. In addition, sensitivities corresponding to these four properties at different times are also compared, to explore the influence of DNAPL dissolution and desorption over time. Results demonstrate that the initial aqueous phase concentration will have a larger impact on downstream mass flux at early times after a DNAPL release

  5. Relationships among the muscle strength properties as assessed through various tests and variables

    PubMed Central

    Prebeg, Goran; Cuk, Ivan; Suzovic, Dejan; Stojiljkovic, Stanimir; Mitic, Dusan; Jaric, Slobodan

    2012-01-01

    We tested the hypotheses that the individual strength properties depend on the applied test and the variable extracted, rather than on the muscle group tested. Flexor and extensor muscles acting in the knee and elbow joint were tested in 58 participants. The standard strength test (SST; based on sustained maximum contraction) and alternating consecutive maximum contractions (ACMC; alternating contractions of antagonistic muscles) performed under static conditions were separately applied to provide the maximum force (F) and the rate of force development (RFD) of each tested muscle. The principal component analysis applied on all 16 variables revealed 3 factors that explained 85.5% of the total variance. Contrary to our hypotheses, the individual factors were loaded with the variables recorded from individual muscles, rather than with either the particular variables or tests. The present findings suggest that recording both F and RFD in routine strength testing procedures could be redundant since they may assess the same strength property of the tested muscle. In addition, ACMC may be a feasible alternative to SST since it could assess the same strength properties from two antagonist muscles through a single trial, while being based on relatively low and transient forces. PMID:23182793

  6. CMOS-MEMS Test-Key for Extracting Wafer-Level Mechanical Properties

    PubMed Central

    Chuang, Wan-Chun; Hu, Yuh-Chung; Chang, Pei-Zen

    2012-01-01

    This paper develops the technologies of mechanical characterization of CMOS-MEMS devices, and presents a robust algorithm for extracting mechanical properties, such as Young’s modulus, and mean stress, through the external electrical circuit behavior of the micro test-key. An approximate analytical solution for the pull-in voltage of bridge-type test-key subjected to electrostatic load and initial stress is derived based on Euler’s beam model and the minimum energy method. Then one can use the aforesaid closed form solution of the pull-in voltage to extract the Young’s modulus and mean stress of the test structures. The test cases include the test-key fabricated by a TSMC 0.18 μm standard CMOS process, and the experimental results refer to Osterberg’s work on the pull-in voltage of single crystal silicone microbridges. The extracted material properties calculated by the present algorithm are valid. Besides, this paper also analyzes the robustness of this algorithm regarding the dimension effects of test-keys. This mechanical properties extracting method is expected to be applicable to the wafer-level testing in micro-device manufacture and compatible with the wafer-level testing in IC industry since the test process is non-destructive. PMID:23235449

  7. Flight and Static Exhaust Flow Properties of an F110-GE-129 Engine in an F-16XL Airplane During Acoustic Tests

    NASA Technical Reports Server (NTRS)

    Holzman, Jon K.; Webb, Lannie D.; Burcham, Frank W., Jr.

    1996-01-01

    The exhaust flow properties (mass flow, pressure, temperature, velocity, and Mach number) of the F110-GE-129 engine in an F-16XL airplane were determined from a series of flight tests flown at NASA Dryden Flight Research Center, Edwards, California. These tests were performed in conjunction with NASA Langley Research Center, Hampton, Virginia (LARC) as part of a study to investigate the acoustic characteristics of jet engines operating at high nozzle pressure conditions. The range of interest for both objectives was from Mach 0.3 to Mach 0.9. NASA Dryden flew the airplane and acquired and analyzed the engine data to determine the exhaust characteristics. NASA Langley collected the flyover acoustic measurements and correlated these results with their current predictive codes. This paper describes the airplane, tests, and methods used to determine the exhaust flow properties and presents the exhaust flow properties. No acoustics results are presented.

  8. Assessment for the Masses: A Historical Critique of High-Stakes Testing in Reading

    ERIC Educational Resources Information Center

    Huddleston, Andrew P.; Rockwell, Elizabeth C.

    2015-01-01

    This historical critique of high-stakes testing in reading focuses on selected events from three historical movements: 1) the history of standardized testing, 2) the history of standardized reading tests, and 3) the history of high-stakes testing. These three interrelated histories have produced the high-stakes, standardized reading tests used in…

  9. Comparing the asteroseismic properties of pulsating extremely low-mass pre-white dwarf stars and δ Scuti stars

    NASA Astrophysics Data System (ADS)

    Arias, J. P. Sánchez; Córsico, A. H.; Romero, A. D.; Althaus, L. G.

    2017-09-01

    We present the first results of a detailed comparison between the pulsation properties of pulsating Extremely Low-Mass pre-white dwarf stars (the pre-ELMV variable stars) and δ Scuti stars. The instability domains of these very different kinds of stars nearly overlap in the log Teff vs. log g diagram, leading to a degeneracy in the classification of the stars. Our aim is to provide asteroseismic tools for their correct classification.

  10. Membrane-Introduction Mass Spectrometry Analysis of Desflurane, Propofol and Fentanyl in Plasma and Cerebrospinal Fluid for Estimation BBB Properties

    PubMed Central

    Cherebillo, Vyacheslav Yu.; Polegaev, Andrei V.

    2015-01-01

    A possibility to use the Membrane-Introduction Mass Spectrometry (MIMS) with membrane separator interface has evolved into a powerful method for measurement of anaesthetic agents absolute concentration in blood plasma and cerebrospinal fluid for the study of blood-brain barrier (BBB) properties. Recent advanced a new membrane material was used for drug concentration measurement in biologic fluids. A hydrophobic membrane was used in the interface to separate anaesthetic agents from biological fluids: inhalational anaesthetic desflurane,hypnotic propofol, analgesic fentanyl. The selective detection of volatile anesthetic agents in blood does not require long-term sample processing before injecting the sample into mass-spectrometer interface, in contrast to chromatographic methods. Mass-spectrometric interface for the measurement of anaesthetic agent concentration in biological fluids (blood plasma and cerebrospinal fluid) is described. Sampling of biological fluids was performed during balanced inhalational (desflurane, fentanyl) anaesthesia and total intravenous (propofol, fentanyl) anaesthesia. PMID:26412969

  11. Impact of mass-loss on the evolution and pre-supernova properties of red supergiants

    NASA Astrophysics Data System (ADS)

    Meynet, G.; Chomienne, V.; Ekström, S.; Georgy, C.; Granada, A.; Groh, J.; Maeder, A.; Eggenberger, P.; Levesque, E.; Massey, P.

    2015-03-01

    Context. The post-main-sequence evolution of massive stars is very sensitive to many parameters of the stellar models. Key parameters are the mixing processes, the metallicity, the mass-loss rate, and the effect of a close companion. Aims: We study the change in the red supergiant (RSG) lifetimes, the tracks in the Hertzsprung-Russel diagram (HRD), the positions in this diagram of the pre-supernova progenitor and the structure of the stars at that time for various mass-loss rates during the RSG phase and for two different initial rotation velocities. Methods: Stellar models were computed with the Geneva code for initial masses between 9 and 25 M⊙ at solar metallicity (Z = 0.014) with 10 times and 25 times the standard mass-loss rates during the RSG phase, with and without rotation. Results: The surface abundances of RSGs are much more sensitive to rotation than to the mass-loss rates during that phase. A change of the RSG mass-loss rate has a strong impact on the RSG lifetimes and in turn on the luminosity function of RSGs. An observed RSG is associated with a model of higher initial mass when models with an enhanced RSG mass-loss rate are used to deduce that mass. At solar metallicity, models with an enhanced mass-loss rate produce significant changes in the populations of blue, yellow, and RSGs. When extended blue loops or blueward excursions are produced by enhanced mass-loss, the models predict that a majority of blue (yellow) supergiants are post-RSG objects. These post-RSG stars are predicted to show much lower surface rotational velocities than similar blue supergiants on their first crossing of the HR gap. Enhanced mass-loss rates during the RSG phase have little impact on the Wolf-Rayet populations. The position in the HRD of the end point of the evolution depends on the mass of the hydrogen envelope. More precisely, whenever at the pre-supernova stage the H-rich envelope contains more than about 5% of the initial mass, the star is a RSG, and whenever

  12. CP violating phase from minimal texture neutrino mass matrix: Test of the phase relevant to leptogenesis

    NASA Astrophysics Data System (ADS)

    Fukugita, Masataka; Kaneta, Yuya; Shimizu, Yusuke; Tanimoto, Morimitsu; Yanagida, Tsutomu T.

    2017-01-01

    The model of neutrino mass matrix with minimal texture is now tightly constrained by experiment so that it can yield a prediction for the phase of CP violation. This phase is predicted to lie in the range δCP = 0.77 π- 1.24 π. If neutrino oscillation experiment would find the CP violation phase outside this range, this means that the minimal-texture neutrino mass matrix, the element of which is all real, fails and the neutrino mass matrix must be complex, i.e., the phase must be present that is responsible for leptogenesis.

  13. Projected color slides as a method for mass screening test for color vision deficiency (a preliminary study).

    PubMed

    Gündogan, Nimet Unay; Durmazlar, Nezih; Gümüş, Koray; Ozdemir, Pinar Geyik; Altintaş, Ayşe Gül; Durur, Irmak; Acaroglu, Gölge

    2005-08-01

    This article compared the efficiency of the mass screening test with projected color slides in detecting color-blindness with the authentic classic method of Ishihara. The study was conducted in a randomly selected lecture room with 104 students aged between 19-25 years (median 21). Using Ishihara projected slides, performed mass screening test. Re-testing was done individually with printed Ishihara plates. Six male and one female with color-blindness were detected. The frequency of color-blindness was 13.6% among males, with a total incidence of 6.7%. The results of two testing methods were compared statistically. Sensitivities and specificities of both tests were 100%. Using projected slides of Ishihara plates instead of the authentic method is an effective and timesaving method for detecting color-blindness. This method can be suggested as a mass-screening test and might be beneficial in detecting color-blindness in large populations such as students, soldiers, and so on.

  14. Experimental validation of damping properties and solar pressure effects on flexible, high area-to-mass ratio debris model

    NASA Astrophysics Data System (ADS)

    Channumsin, Sittiporn; Ceriotti, Matteo; Radice, Gianmarco; Watson, Ian

    2017-09-01

    Multilayer insulation (MLI) is a recently-discovered type of debris originating from delamination of aging spacecraft; it is mostly detected near the geosynchronous orbit (GEO). Observation data indicates that these objects are characterised by high reflectivity, high area-to-mass ratio (HAMR), fast rotation, high sensitivity to perturbations (especially solar radiation pressure) and change of area-to-mass ratio (AMR) over time. As a result, traditional models (e.g. cannonball) are unsuitable to represent and predict this debris' orbital evolution. Previous work by the authors effectively modelled the flexible debris by means of multibody dynamics to improve the prediction accuracy. The orbit evolution with the flexible model resulted significantly different from using the rigid model. This paper aims to present a methodology to determine the dynamic properties of thin membranes with the purpose to validate the deformation characteristics of the flexible model. A high-vacuum chamber (10-4 mbar) to significantly decrease air friction, inside which a thin membrane is hinged at one end but free at the other provides the experimental setup. A free motion test is used to determine the damping characteristics and natural frequency of the thin membrane via logarithmic decrement and frequency response. The membrane can swing freely in the chamber and the motion is tracked by a static, optical camera, and a Kalman filter technique is implemented in the tracking algorithm to reduce noise and increase the tracking accuracy of the oscillating motion. Then, the effect of solar radiation pressure on the thin membrane is investigated: a high power spotlight (500-2000 W) is used to illuminate the sample and any displacement of the membrane is measured by means of a high-resolution laser sensor. Analytic methods from the natural frequency response and Finite Element Analysis (FEA) including multibody simulations of both experimental setups are used for the validation of the

  15. Negative, positive, and infinite mass properties of a rotating electron beam

    SciTech Connect

    French, David M.; Lau, Y. Y.; Gilgenbach, R. M.; Hoff, Brad W.

    2010-09-13

    An electron rotating under a uniform axial magnetic field and a radial electric field exhibits an effective mass that may be negative, positive, or infinite, in response to an azimuthal electric field. This paper reports simulation results that show instability and stability when the effective mass are negative and positive, respectively, depending on the magnitude and orientation of the radial electric field. Thus, the inverted magnetron would have a much faster startup than the conventional magnetron, an important consideration for pulsed operation. When the effective mass is infinite, the electrons hardly respond to an azimuthal ac electric field.

  16. Flammability properties and radiant fraction of FRT wood plastic composites using mass loss calorimeter under HRR hood

    Treesearch

    Mark A. Dietenberger; Charles R. Boardman; Nicole Stark

    2017-01-01

    A special test arrangement was used to assess the flammability of 4 different wood plastic composites (WPC), most with fire retardants, all of which has a tendency to high smoke production leading to high radiant energy losses to the apparatus walls. The mass loss calorimeter (MLC) was modified to include a thermopile on the exhaust pipe stack to compensate for radiant...

  17. The relationship of conodont biofacies to spatially variable water mass properties in the Late Pennsylvanian Midcontinent Sea

    NASA Astrophysics Data System (ADS)

    Herrmann, Achim D.; Barrick, James E.; Algeo, Thomas J.

    2015-03-01

    Molybdenum and uranium enrichment factors and nitrogen isotopes suggest that an interplay of open ocean upwelling and riverine runoff led to distinct spatial and secular variations in water mass properties within the epicontinental Late Pennsylvanian Midcontinent Sea of North America. In particular, the intensity of continental runoff influenced the flux of bulk organic matter to the sediment. Benthic anoxia appears to have been controlled by the vertical density gradient in the water column associated with continental runoff combined with the advection of basinal water. Anoxic conditions were stronger in proximal (i.e., more shoreward) areas of the Midcontinent Shelf, indicating that anoxia did not develop primarily due to upwelling of nutrient-rich waters along the southern shelf margin, as previously suggested. Changes in water mass redox conditions not only drove authigenic enrichment of redox-sensitive trace elements across the basin but also had a strong effect on the spatial distribution of various conodont taxa. Our analysis suggests that the widely accepted depth-stratification model for the distribution of conodonts is incomplete. Conodont biofacies distributions seem to have been controlled by physicochemical properties of the water mass (e.g., salinity, temperature, nutrients, turbidity, and/or dissolved oxygen levels) that may correspond less directly to water depth. The proximity to terrestrial freshwater influx and the strength of anoxia/euxinia in the subpycnoclinal water mass played significant roles in the spatial and temporal distributions of conodont taxa.

  18. Collective properties of neutron-star X-ray binary populations of galaxies. II. Pre-low-mass X-ray binary properties, formation rates, and constraints

    SciTech Connect

    Bhadkamkar, H.; Ghosh, P.

    2014-04-01

    We continue our exploration of the collective properties of neutron-star X-ray binaries in the stellar fields (i.e., outside globular clusters) of normal galaxies. In Paper I of this series, we considered high-mass X-ray binaries (HMXBs). In this paper (Paper II), we consider low-mass X-ray binaries (LMXBs), whose evolutionary scenario is very different from that of HMXBs. We consider the evolution of primordial binaries up to the stage where the neutron star just formed in the supernova explosion of the primary is in a binary with its low-mass, unevolved companion, and this binary has circularized tidally, producing what we call a pre-low-mass X-ray binary (pre-LMXB). We study the constraints on the formation of such pre-LMXBs in detail (since these are low-probability events), and calculate their collective properties and formation rates. To this end, we first consider the changes in the binary parameters in the various steps involved, viz., the common-envelope phase, the supernova, and the tidal evolution. This naturally leads to a clarification of the constraints. We then describe our calculation of the evolution of the distributions of primordial binary parameters into those of pre-LMXB parameters, following the standard evolutionary scenario for individual binaries. We display the latter as both bivariate and monovariate distributions, discuss their essential properties, and indicate the influences of some essential factors on these. Finally, we calculate the formation rate of these pre-LMXBs. The results of this paper will be used in a subsequent one to compute the expected X-ray luminosity function of LMXBs.

  19. Psychometric properties of the eating attitudes test and children's eating attitudes test in Croatia.

    PubMed

    Ambrosi-Randić, N; Pokrajac-Bulian, A

    2005-12-01

    The factor structure of the children's version of the Eating Attitudes Test (ChEAT) and Eating Attitudes Test (EAT-26) were examined in Croatian girls of different ages. A self-report survey was given to 225 girls (Grades 5 to 8), 525 high school girls (Grades 9 to 12), and 646 female university students. Factor analysis revealed the existence of four factors for ChEAT, and three interpretable factors for EAT-26. Internal consistency of both instruments was satisfactory. 10.3% of school girls scored 20 or higher on ChEAT, when 7.6% of high school girls and 11.3% of university students had elevated EAT-26 scores. The ChEAT and EAT-26 were useful for screening large non-clinical groups and measuring disturbed eating behaviours. Those with elevated ChEAT and EAT-26 scores were more likely than those with lower scores to be engaged in extreme weight control methods (e.g. vomiting, binging).

  20. Testing neutrino mass generation mechanisms from the lepton flavor violating decay of the Hig