Lifetime Prediction of Nano-Silica based Glass Fibre/Epoxy composite by Time Temperature Superposition Principle

NASA Astrophysics Data System (ADS)

Anand, Abhijeet; Banerjee, Poulami; Prusty, Rajesh Kumar; Ray, Bankin Chandra

2018-03-01

The incorporation of nano fillers in Fibre reinforced polymer (FRP) composites has been a source of experimentation for researchers. Addition of nano fillers has been found to improve mechanical, thermal as well as electrical properties of Glass fibre reinforced polymer (GFRP) composites. The in-plane mechanical properties of GFRP composite are mainly controlled by fibers and therefore exhibit good values. However, composite exhibits poor through-thickness properties, in which the matrix and interface are the dominant factors. Therefore, it is conducive to modify the matrix through dispersion of nano fillers. Creep is defined as the plastic deformation experienced by a material for a temperature at constant stress over a prolonged period of time. Determination of Master Curve using time-temperature superposition principle is conducive for predicting the lifetime of materials involved in naval and structural applications. This is because such materials remain in service for a prolonged time period before failure which is difficult to be kept marked. However, the failure analysis can be extrapolated from its behaviour in a shorter time at an elevated temperature as is done in master creep analysis. The present research work dealt with time-temperature analysis of 0.1% SiO2-based GFRP composites fabricated through hand-layup method. Composition of 0.1% for SiO2nano fillers with respect to the weight of the fibers was observed to provide optimized flexural properties. Time and temperature dependence of flexural properties of GFRP composites with and without nano SiO2 was determined by conducting 3-point bend flexural creep tests over a range of temperature. Stepwise isothermal creep tests from room temperature (30°C) to the glass transition temperature Tg (120°C) were performed with an alternative creep/relaxation period of 1 hour at each temperature. A constant stress of 40MPa was applied during the creep tests. The time-temperature superposition principle was followed while determining the Master Curve and cumulative damage law. The purpose of a Master Curve was to determine the variation of compliance with respect to increase in time and temperature of the specimen. The shift factors at any reference temperature were determined by Arrhenius activation energy method at a far lower temperature than Tg (Glass transition temperature) and by manual shift method at a temperature near Tg (Glass transition temperature).

Age dependence of Olympic weightlifting ability.

PubMed

Meltzer, D E

1994-08-01

There is increasing interest among Masters athletes in standards for comparing performances of competitors of different ages. The goal of this study was to develop one such age-comparison method by examining the age dependence of ability in Olympic-style weightlifting. Previous research on the deterioration of muscular strength and power with increasing age offers only limited guidance toward this goal; therefore, analysis of performance data was required. The variation of weightlifting ability as a function of age was examined by two different methods. First, cross-sectional data corresponding to two separate populations of Masters weightlifters were analyzed in detail. Then, a longitudinal study of 64 U.S. male Masters weightlifters was carried out, with performance versus age curves resulting from the two methods were very similar, reflecting approximately 1.0-1.5% x yr-1 deterioration rates. These curves were characterized by common features regarding the rate of decline of muscular power with increasing age, in apparent agreement with published data regarding Masters sprinters and jumpers. We tentatively conclude that Olympic weightlifting ability in trained subjects undergoes a nonlinear decline with age, in which the second derivative of the performance versus age curve repeatedly changes sign.

Nondestructive evaluation of the complex modulus master curve of asphalt concrete specimens

NASA Astrophysics Data System (ADS)

Gudmarsson, A.; Ryden, N.; Birgisson, B.

2013-01-01

The dynamic Young's modulus of asphalt concrete is directly related to pavement quality and is used in thickness design of pavements. There is a need for a nondestructive laboratory method to evaluate the complex modulus, which can be linked to nondestructive field measurements. This study applies seismic measurements to an asphalt concrete beam where resonant acoustic spectroscopy and optimization of frequency response functions are used to estimate the complex moduli. A good estimation of the master curve is obtained.

In vitro vaccine potency testing: a proposal for reducing animal use for requalification testing.

PubMed

Brown, K; Stokes, W

2012-01-01

This paper proposes a program under which the use of animals for requalification of in vitro potency tests could be eliminated. Standard References (USDA/CVB nomenclature) would be developed, characterized, stored and monitored by selected reference laboratories worldwide. These laboratories would employ scientists skilled in protein and glycoprotein chemistry and equipped with state-of-the-art instruments for required analyses. After Standard References are established, the reference laboratories would provide them to the animal health industry as "gold standards". Companies would then establish and validate a correlation between the Standard Reference and the company Master Reference (USDA/CVB nomenclature) using an internal in vitro assay. After this correlation is established, the company could use the Standard References for qualifying, monitoring and requalifying company Master References without the use of animals. Such a program would eliminate the need for animals for requalification of Master References and the need for each company to develop and validate a battery of Master Reference Monitoring assays. It would also provide advantages in terms of reduced costs and reduced time for requalification testing. As such it would provide a strong incentive for companies to develop and use in vitro assays for potency testing.

Towards a universal master curve in magnetorheology

NASA Astrophysics Data System (ADS)

Ruiz-López, José Antonio; Hidalgo-Alvarez, Roque; de Vicente, Juan

2017-05-01

We demonstrate that inverse ferrofluids behave as model magnetorheological fluids. A universal master curve is proposed, using a reduced Mason number, under the frame of a structural viscosity model where the magnetic field strength dependence is solely contained in the Mason number and the particle concentration is solely contained in the critical Mason number (i.e. the yield stress). A linear dependence of the critical Mason number with the particle concentration is observed that is in good agreement with a mean (average) magnetization approximation, particle level dynamic simulations and micromechanical models available in the literature.

Advising Master's Students Pursuing Doctoral Study: A Survey of Counselor Educators and Supervisors

ERIC Educational Resources Information Center

Sackett, Corrine R.; Hartig, Nadine; Bodenhorn, Nancy; Farmer, Laura B.; Ghoston, Michelle R.; Graham, Jasmine; Lile, Jesse

2015-01-01

This study explored what faculty members are recommending to counselor education master's students regarding post-master's experience when considering doctoral studies and what the current faculty hiring preferences are in reference to the amount of post-master's experience needed. Advisors in counselor education master's programs encounter these…

CEBAF Superconducting Cavity RF Drive System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fugitt, Jock; Moore, Thomas

1987-03-01

The CEBAR RF system consists of 418 individual RF amplifier chains. Each superconducting cavity is phase locked to the master drive reference line to within 1 degree, and the cavity field gradient is regulated to within 1 part in 10 by a state-of-the-art RF control module. Precision, continuously adjustable, modulo 360 phase shifters are used to generate the individual phase references, and a compensated RF detector is used for level feedback. The close coupled digital system enhances system accuracy, provides self-calibration, and continuously checks the system for malfunction. Calibration curves, the operating program, and system history are stored in anmore » on board EEPROM. The RF power is generated by a 5Kw, water cooled, permanent magnet focused klystorn. The klystons are clustered in groups of 8 and powered from a common supply. RF power is transmitted to the accelerator sections by semiflexible waveguide.« less

Universal rescaling of flow curves for yield-stress fluids close to jamming

NASA Astrophysics Data System (ADS)

Dinkgreve, M.; Paredes, J.; Michels, M. A. J.; Bonn, D.

2015-07-01

The experimental flow curves of four different yield-stress fluids with different interparticle interactions are studied near the jamming concentration. By appropriate scaling with the distance to jamming all rheology data can be collapsed onto master curves below and above jamming that meet in the shear-thinning regime and satisfy the Herschel-Bulkley and Cross equations, respectively. In spite of differing interactions in the different systems, master curves characterized by universal scaling exponents are found for the four systems. A two-state microscopic theory of heterogeneous dynamics is presented to rationalize the observed transition from Herschel-Bulkley to Cross behavior and to connect the rheological exponents to microscopic exponents for the divergence of the length and time scales of the heterogeneous dynamics. The experimental data and the microscopic theory are compared with much of the available literature data for yield-stress systems.

New method for calculating a mathematical expression for streamflow recession

USGS Publications Warehouse

Rutledge, Albert T.

1991-01-01

An empirical method has been devised to calculate the master recession curve, which is a mathematical expression for streamflow recession during times of negligible direct runoff. The method is based on the assumption that the storage-delay factor, which is the time per log cycle of streamflow recession, varies linearly with the logarithm of streamflow. The resulting master recession curve can be nonlinear. The method can be executed by a computer program that reads a data file of daily mean streamflow, then allows the user to select several near-linear segments of streamflow recession. The storage-delay factor for each segment is one of the coefficients of the equation that results from linear least-squares regression. Using results for each recession segment, a mathematical expression of the storage-delay factor as a function of the log of streamflow is determined by linear least-squares regression. The master recession curve, which is a second-order polynomial expression for time as a function of log of streamflow, is then derived using the coefficients of this function.

Application of fracture toughness scaling models to the ductile-to- brittle transition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Link, R.E.; Joyce, J.A.

1996-01-01

An experimental investigation of fracture toughness in the ductile-brittle transition range was conducted. A large number of ASTM A533, Grade B steel, bend and tension specimens with varying crack lengths were tested throughout the transition region. Cleavage fracture toughness scaling models were utilized to correct the data for the loss of constraint in short crack specimens and tension geometries. The toughness scaling models were effective in reducing the scatter in the data, but tended to over-correct the results for the short crack bend specimens. A proposed ASTM Test Practice for Fracture Toughness in the Transition Range, which employs a mastermore » curve concept, was applied to the results. The proposed master curve over predicted the fracture toughness in the mid-transition and a modified master curve was developed that more accurately modeled the transition behavior of the material. Finally, the modified master curve and the fracture toughness scaling models were combined to predict the as-measured fracture toughness of the short crack bend and the tension specimens. It was shown that when the scaling models over correct the data for loss of constraint, they can also lead to non-conservative estimates of the increase in toughness for low constraint geometries.« less

A new experimental method for the accelerated characterization of composite materials

NASA Technical Reports Server (NTRS)

Brinson, H. F.; Morris, D. H.; Yeow, Y. T.

1978-01-01

A method which permits the prediction of long-term properties of graphite/epoxy laminates on the basis of short-term (15 min) laboratory tests is described. Demonstration of delayed viscoelastic fracture in one laminate configuration, and data on the time and temperature response of a matrix-dominated unidirectional laminate contributed to a characterization of the viscoelastic process in the graphite/epoxy composites. Master curves from short-term tests of certain laminate configurations can be employed to generate long-term master curves. In addition, analytical predictions from short-term results can be used to predict long-term (25-hour) laminate properties.

The Consolidated Human Activity Database — Master Version (CHAD-Master) Technical Memorandum

EPA Pesticide Factsheets

This technical memorandum contains information about the Consolidated Human Activity Database -- Master version, including CHAD contents, inventory of variables: Questionnaire files and Event files, CHAD codes, and references.

Validation of Modifications to the ANSR for Listeria Method for Improved Internal Positive Control Performance.

PubMed

Alles, Susan; Meister, Evan; Hosking, Edan; Tovar, Eric; Shaulis, Rebecca; Schonfeld, Mark; Zhang, Lei; Li, Lin; Biswas, Preetha; Mozola, Mark; Donofrio, Robert; Chen, Yi

2018-03-01

A study was conducted to validate a minor reagent formulation change to the ANSR for Listeria method, Performance Tested MethodSM 101202. This change involves increasing the master mix volume prelyophilization by 40% and addition of salmon sperm DNA (nontarget DNA) to the master mix. These changes improve the robustness of the internal positive control response and reduce the possibility of obtaining invalid results due to weak-positive control curves. When three foods (hot dogs, Mexican-style cheese, and cantaloupe) and sponge samples taken from a stainless steel surface were tested, no significant differences in performance between the ANSR and U.S. Food and Drug Administration Bacteriological Analytical Manual or U.S. Department of Agriculture-Food Safety and Inspection Service Microbiology Laboratory Guidebook reference culture procedures were observed for any of the matrixes as determined by probability of detection analysis. Inclusivity and exclusivity testing yielded 100% expected results for target and nontarget bacteria. Accelerated stability testing was carried out over a 7 week period and showed no decrease in assay performance over time.

21 CFR 814.3 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-04-01

.... (d) Master file means a reference source that a person submits to FDA. A master file may contain detailed information on a specific manufacturing facility, process, methodology, or component used in the... for a class III medical device, including all information submitted with or incorporated by reference...

A cascade feedback control approach for hypnosis.

PubMed

Puebla, Hector; Alvarez-Ramírez, José

2005-10-01

This article studies the problem of controlling the drug administration during an anesthesia process, where muscle relaxation, analgesia, and hypnosis are regulated by means of monitored administration of specific drugs. On the basis of a seventh-order nonlinear pharmacokinetic-pharmacodynamic representation of the hypnosis process dynamics, a cascade (master/slave) feedback control structure for controlling the bispectral index (BIS) is proposed. The master controller compares the measured BIS with its reference value to provide the expired isoflurane concentration reference to the slave controller. In turn, the slave controller manipulates the anesthetic isoflurane concentration entering the anesthetic system to achieve the reference from the master controller. The advantage of the proposed cascade control structure with respect to its noncascade counterpart is that the former provides operation protection against BIS measurement failures. In fact, under a BIS measurement fault, the master control feedback is broken and the slave controller operates under a safe reference value. Extensive numerical simulations are used to illustrate the functioning of the proposed cascade control structure.

Fracture-Toughness Analysis in Transition-Temperature Region of Three American Petroleum Institute X70 and X80 Pipeline Steels

NASA Astrophysics Data System (ADS)

Shin, Sang Yong; Woo, Kuk Je; Hwang, Byoungchul; Kim, Sangho; Lee, Sunghak

2009-04-01

The fracture toughness in the transition-temperature region of three American Petroleum Institute (API) X70 and X80 pipeline steels was analyzed in accordance with the American Society for Testing and Materials (ASTM) E1921-05 standard test method. The elastic-plastic cleavage fracture toughness ( K Jc ) was determined by three-point bend tests, using precracked Charpy V-notch (PCVN) specimens; the measured K Jc values were then interpreted by the three-parameter Weibull distribution. The fracture-toughness test results indicated that the master curve and the 98 pct confidence curves explained the variation in the measured fracture toughness well. The reference temperatures obtained from the fracture-toughness test and index temperatures obtained from the Charpy impact test were lowest in the X70 steel rolled in the two-phase region, because this steel had smaller effective grains and the lowest volume fraction of hard phases. In this steel, few hard phases led to a higher resistance to cleavage crack initiation, and the smaller effective grain size led to a higher possibility of crack arrest, thereby resulting in the best overall fracture properties. Measured reference temperatures were then comparatively analyzed with the index temperatures obtained from the Charpy impact test, and the effects of microstructures on these temperatures were discussed.

An Approximate Solution and Master Curves for Buckling of Symmetrically Laminated Composite Cylinders

NASA Technical Reports Server (NTRS)

Nemeth, Michael P.

2013-01-01

Nondimensional linear-bifurcation buckling equations for balanced, symmetrically laminated cylinders with negligible shell-wall anisotropies and subjected to uniform axial compression loads are presented. These equations are solved exactly for the practical case of simply supported ends. Nondimensional quantities are used to characterize the buckling behavior that consist of a stiffness-weighted length-to-radius parameter, a stiffness-weighted shell-thinness parameter, a shell-wall nonhomogeneity parameter, two orthotropy parameters, and a nondimensional buckling load. Ranges for the nondimensional parameters are established that encompass a wide range of laminated-wall constructions and numerous generic plots of nondimensional buckling load versus a stiffness-weighted length-to-radius ratio are presented for various combinations of the other parameters. These plots are expected to include many practical cases of interest to designers. Additionally, these plots show how the parameter values affect the distribution and size of the festoons forming each response curve and how they affect the attenuation of each response curve to the corresponding solution for an infinitely long cylinder. To aid in preliminary design studies, approximate formulas for the nondimensional buckling load are derived, and validated against the corresponding exact solution, that give the attenuated buckling response of an infinitely long cylinder in terms of the nondimensional parameters presented herein. A relatively small number of "master curves" are identified that give a nondimensional measure of the buckling load of an infinitely long cylinder as a function of the orthotropy and wall inhomogeneity parameters. These curves reduce greatly the complexity of the design-variable space as compared to representations that use dimensional quantities as design variables. As a result of their inherent simplicity, these master curves are anticipated to be useful in the ongoing development of buckling-design technology.

MASTER OT J004207.99+405501.1/M31LRN 2015 luminous red nova in M31: discovery, light curve, hydrodynamics and evolution

NASA Astrophysics Data System (ADS)

Lipunov, V. M.; Blinnikov, S.; Gorbovskoy, E.; Tutukov, A.; Baklanov, P.; Krushinski, V.; Tiurina, N.; Balanutsa, P.; Kuznetsov, A.; Kornilov, V.; Gorbunov, I.; Shumkov, V.; Vladimirov, V.; Gress, O.; Budnev, N. M.; Ivanov, K.; Tlatov, A.; Gabovich, A.; Yurkov, V.; Sergienko, Yu.; Zalozhnykh, I.

2017-09-01

We report the discovery and multicolour (VRIW) photometry of the rare explosive star MASTER OT J004207.99+405501.1 - a luminous red nova - in the Andromeda galaxy M31N2015-01a. We use our original light curve acquired with identical MASTER Global Robotic Net telescopes in one photometric system: VRI during the first 30 d and W (unfiltered) during 70 d. Also, we added published multicolour photometry data to estimate the mass and energy of the ejected shell and we discuss the likely formation scenarios of outbursts of this type. We propose an interpretation of the explosion that is consistent with an evolutionary scenario where the merging of stellar components or the disruption of the common envelope of a close binary can explain some luminous red novae. Radiative hydrodynamic simulations of a luminous red nova were carried out in extended parameter space to fit its light curves. We find that the multicolour passband light curves of the luminous red nova are consistent with an initial common envelope radius of 10 R⊙, a merger mass of 3 M⊙ and an explosion energy of 3 × 1048 erg. As a result, the phenomenon of novae consists of two classes: classical nuclear novae and more rare events (red novae) connected with the loss of compact common envelopes.

The intrinsic mechanical nonlinearity 3Q0(ω) of linear homopolymer melts

NASA Astrophysics Data System (ADS)

Cziep, Miriam Angela; Abbasi, Mahdi; Wilhelm, Manfred

2017-05-01

Medium amplitude oscillatory shear (MAOS) in combination with Fourier Transformation of the mechanical stress signal (FT rheology) was utilized to investigate the influence of molecular weight, molecular weight distribution and the monomer on the intrinsic nonlinearity 3Q0(ω). Nonlinear master curves of 3Q0(ω) have been created, applying the time-temperature superposition (TTS) principle. These master curves showed a characteristic shape with an increasing slope at small frequencies, a maximum 3Q0,max and a decreasing slope at high frequencies. 3Q0(De) master curves of monodisperse polymers were evaluated and quantified with the help of a semi-empiric equation, derived from predictions from the pom-pom and molecular stress function (MSF) models. This resulted in a monomer independent description of the nonlinear mechanical behavior of linear, monodisperse homopolymer melts, where 3Q0(ω,Z) is only a function of the frequency ω and the number of entanglements Z. For polydisperse samples, 3Q0(ω) showed a high sensitivity within the experimental window towards an increasing PDI. At small frequencies, the slope of 3Q0(ω) decreases until approximately zero as a plateau value is reached, starting at a PDI around 2 and higher.

A Software Tool for the Rapid Analysis of the Sintering Behavior of Particulate Bodies

DTIC Science & Technology

2017-11-01

bounded by a region that the user selects via cross hairs . Future plot analysis features, such as more complicated curve fitting and modeling functions...German RM. Grain growth behavior of tungsten heavy alloys based on the master sintering curve concept. Metallurgical and Materials Transactions A

Corresponding states law for a generalized Lennard-Jones potential.

PubMed

Orea, P; Romero-Martínez, A; Basurto, E; Vargas, C A; Odriozola, G

2015-07-14

It was recently shown that vapor-liquid coexistence densities derived from Mie and Yukawa models collapse to define a single master curve when represented against the difference between the reduced second virial coefficient at the corresponding temperature and that at the critical point. In this work, we further test this proposal for another generalization of the Lennard-Jones pair potential. This is carried out for vapor-liquid coexistence densities, surface tension, and vapor pressure, along a temperature window set below the critical point. For this purpose, we perform molecular dynamics simulations by varying the potential softness parameter to produce from very short to intermediate attractive ranges. We observed all properties to collapse and yield master curves. Moreover, the vapor-liquid curve is found to share the exact shape of the Mie and attractive Yukawa. Furthermore, the surface tension and the logarithm of the vapor pressure are linear functions of this difference of reduced second virial coefficients.

Force spectroscopy of quadruple H-bonded dimers by AFM: dynamic bond rupture and molecular time-temperature superposition.

PubMed

Zou, Shan; Schönherr, Holger; Vancso, G Julius

2005-08-17

We report on the application of the time-temperature superposition principle to supramolecular bond-rupture forces on the single-molecule level. The construction of force-loading rate master curves using atomic force microscopy (AFM)-based single-molecule force spectroscopy (SMFS) experiments carried out in situ at different temperatures allows one to extend the limited range of the experimentally accessible loading rates and hence to cross from thermodynamic nonequilibrium to quasi-equilibrium states. The approach is demonstrated for quadruple H-bonded ureido-4[1H]-pyrimidinone (UPy) moieties studied by variable-temperature SMFS in organic media. The unbinding forces of single quadruple H-bonding (UPy)2 complexes, which were identified based on a polymeric spacer strategy, were found to depend on the loading rate in the range of 5 nN/s to 500 nN/s at 301 K in hexadecane. By contrast, these rupture forces were independent of the loading rate from 5 to 200 nN/s at 330 K. These results indicate that the unbinding behavior of individual supramolecular complexes can be directly probed under both thermodynamic nonequilibrium and quasi-equilibrium conditions. On the basis of the time-temperature superposition principle, a master curve was constructed for a reference temperature of 301 K, and the crossover force (from loading-rate independent to -dependent regimes) was determined as approximately 145 pN (at a loading rate of approximately 5.6 nN/s). This approach significantly broadens the accessible loading-rate range and hence provides access to fine details of potential energy landscape of supramolecular complexes based on SMFS experiments.

Creep rupture of polymer-matrix composites

NASA Technical Reports Server (NTRS)

Brinson, H. F.; Morris, D. H.; Griffith, W. I.

1981-01-01

The time-dependent creep-rupture process in graphite-epoxy laminates is examined as a function of temperature and stress level. Moisture effects are not considered. An accelerated characterization method of composite-laminate viscoelastic modulus and strength properties is reviewed. It is shown that lamina-modulus master curves can be obtained using a minimum of normally performed quality-control-type testing. Lamina-strength master curves, obtained by assuming a constant-strain-failure criterion, are presented along with experimental data, and reasonably good agreement is shown to exist between the two. Various phenomenological delayed failure models are reviewed and two (the modified rate equation and the Larson-Miller parameter method) are compared to creep-rupture data with poor results.

CEC-normalized clay-water sorption isotherm

NASA Astrophysics Data System (ADS)

Woodruff, W. F.; Revil, A.

2011-11-01

A normalized clay-water isotherm model based on BET theory and describing the sorption and desorption of the bound water in clays, sand-clay mixtures, and shales is presented. Clay-water sorption isotherms (sorption and desorption) of clayey materials are normalized by their cation exchange capacity (CEC) accounting for a correction factor depending on the type of counterion sorbed on the mineral surface in the so-called Stern layer. With such normalizations, all the data collapse into two master curves, one for sorption and one for desorption, independent of the clay mineralogy, crystallographic considerations, and bound cation type; therefore, neglecting the true heterogeneity of water sorption/desorption in smectite. The two master curves show the general hysteretic behavior of the capillary pressure curve at low relative humidity (below 70%). The model is validated against several data sets obtained from the literature comprising a broad range of clay types and clay mineralogies. The CEC values, derived by inverting the sorption/adsorption curves using a Markov chain Monte Carlo approach, are consistent with the CEC associated with the clay mineralogy.

"Yes, Master's": A Graduate Degree's Moment in the Age of Higher Education Innovation

ERIC Educational Resources Information Center

Gallagher, Sean

2014-01-01

Over the past decade, enrollment in professional master's degree programs has grown substantially, and this category has outpaced the overall recent flattening of college enrollment. Today, 5 million more U.S. adults hold a master's degree compared with a decade ago, and in some circles the master's is being referred to as "the…

A Hierarchical Modeling for Reactive Power Optimization With Joint Transmission and Distribution Networks by Curve Fitting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ding, Tao; Li, Cheng; Huang, Can

Here, in order to solve the reactive power optimization with joint transmission and distribution networks, a hierarchical modeling method is proposed in this paper. It allows the reactive power optimization of transmission and distribution networks to be performed separately, leading to a master–slave structure and improves traditional centralized modeling methods by alleviating the big data problem in a control center. Specifically, the transmission-distribution-network coordination issue of the hierarchical modeling method is investigated. First, a curve-fitting approach is developed to provide a cost function of the slave model for the master model, which reflects the impacts of each slave model. Second,more » the transmission and distribution networks are decoupled at feeder buses, and all the distribution networks are coordinated by the master reactive power optimization model to achieve the global optimality. Finally, numerical results on two test systems verify the effectiveness of the proposed hierarchical modeling and curve-fitting methods.« less

A Hierarchical Modeling for Reactive Power Optimization With Joint Transmission and Distribution Networks by Curve Fitting

DOE PAGES

Ding, Tao; Li, Cheng; Huang, Can; ...

2017-01-09

Here, in order to solve the reactive power optimization with joint transmission and distribution networks, a hierarchical modeling method is proposed in this paper. It allows the reactive power optimization of transmission and distribution networks to be performed separately, leading to a master–slave structure and improves traditional centralized modeling methods by alleviating the big data problem in a control center. Specifically, the transmission-distribution-network coordination issue of the hierarchical modeling method is investigated. First, a curve-fitting approach is developed to provide a cost function of the slave model for the master model, which reflects the impacts of each slave model. Second,more » the transmission and distribution networks are decoupled at feeder buses, and all the distribution networks are coordinated by the master reactive power optimization model to achieve the global optimality. Finally, numerical results on two test systems verify the effectiveness of the proposed hierarchical modeling and curve-fitting methods.« less

Master's Training as a Part of Young Researcher's Professional Development: British and Ukrainian Experience

ERIC Educational Resources Information Center

Bidyuk, Natalya

2014-01-01

The problem of the professional development of young researchers in terms of Master's training has been analyzed. The analysis of the literature references, documental and other sources gave grounds to state that the basic principle of Master's professional training is a research-oriented paradigm. The necessity of using the innovative ideas of…

Direct manipulation of tool-like masters for controlling a master-slave surgical robotic system.

PubMed

Zhang, Linan; Zhou, Ningxin; Wang, Shuxin

2014-12-01

Robotic-assisted minimally invasive surgery (MIS) can benefit both patients and surgeons. However, the learning curve for robotically assisted procedures can be long and the total system costs are high. Therefore, there is considerable interest in new methods and lower cost controllers for a surgical robotic system. In this study, a knife-master and a forceps-master, shaped similarly to a surgical knife and forceps, were developed as input devices for control of a master-slave surgical robotic system. In addition, a safety strategy was developed to eliminate the master-slave orientation difference and stabilize the surgical system. Master-slave tracking experiments and a ring-and-bar experiment showed that the safety tracking strategy could ensure that the robot system moved stably without any tremor in the tracking motion. Subjects could manipulate the surgical tool to achieve the master-slave operation with less training compared to a mechanical master. Direct manipulation of the small, light and low-cost surgical tools to control a robotic system is a possible operating mode. Surgeons can operate the robotic system in their own familiar way, without long training. The main potential safety issues can be solved by the proposed safety control strategy. Copyright © 2013 John Wiley & Sons, Ltd.

Application of the compensated Arrhenius formalism to explain the dielectric constant dependence of rates for Menschutkin reactions.

PubMed

Petrowsky, Matt; Glatzhofer, Daniel T; Frech, Roger

2013-11-21

The dependence of the reaction rate on solvent dielectric constant is examined for the reaction of trihexylamine with 1-bromohexane in a series of 2-ketones over the temperature range 25-80 °C. The rate constant data are analyzed using the compensated Arrhenius formalism (CAF), where the rate constant assumes an Arrhenius-like equation that also contains a dielectric constant dependence in the exponential prefactor. The CAF activation energies are substantially higher than those obtained using the simple Arrhenius equation. A master curve of the data is observed by plotting the prefactors against the solvent dielectric constant. The master curve shows that the reaction rate has a weak dependence on dielectric constant for values approximately less than 10 and increases more rapidly for dielectric constant values greater than 10.

Creep rupture behavior of unidirectional advanced composites

NASA Technical Reports Server (NTRS)

Yeow, Y. T.

1980-01-01

A 'material modeling' methodology for predicting the creep rupture behavior of unidirectional advanced composites is proposed. In this approach the parameters (obtained from short-term tests) required to make the predictions are the three principal creep compliance master curves and their corresponding quasi-static strengths tested at room temperature (22 C). Using these parameters in conjunction with a failure criterion, creep rupture envelopes can be generated for any combination of in-plane loading conditions and ambient temperature. The analysis was validated experimentally for one composite system, the T300/934 graphite-epoxy system. This was done by performing short-term creep tests (to generate the principal creep compliance master curves with the time-temperature superposition principle) and relatively long-term creep rupture tensile tests of off-axis specimens at 180 C. Good to reasonable agreement between experimental and analytical results is observed.

Offline motion planning and simulation of two-robot welding coordination

NASA Astrophysics Data System (ADS)

Zhang, Tie; Ouyang, Fan

2012-03-01

This paper focuses on the two-robot welding coordination of complex curve seam which means one robot grasp the workpiece, the other hold the torch, the two robots work on the same workpiece simultaneously. This paper builds the dual-robot coordinate system at the beginning, and three point calibration method of two robots' relative base coordinate system is presented. After that, the non master/slave scheme is chosen for the motion planning, the non master/slave scheme sets the poses versus time function of the point u on the workpiece, and calculates the two robot end effecter trajectories through the constrained relationship matrix automatically. Moreover, downhand welding is employed which can guarantee the torch and the seam keep in good contact condition all the time during the welding. Finally, a Solidworks-Sim Mechanics simulation platform is established, and a simulation of curved steel pipe welding is conducted. The results of the simulation illustrate the welding process can meet the requirements of downhand welding, the joint displacement curves are smooth and continuous and no joint velocities are out of working scope.

Characterization of viscoelastic response and damping of composite materials used in flywheel rotors

NASA Astrophysics Data System (ADS)

Chen, Jianmin

The long-term goal for spacecraft flywheel systems with higher energy density at the system level requires new and innovative composite material concepts. Multi-Direction Composite (MDC) offers significant advantages over traditional filament-wound and multi-ring press-fit filament-wound wheels in providing higher energy density (i.e., less mass), better crack resistance, and enhanced safety. However there is a lack of systematic characterization for dynamic properties of MDC composite materials. In order to improve the flywheel materials reliability, durability and life time, it is very important to evaluate the time dependent aging effects and damping properties of MDC material, which are significant dynamic parameter for vibration and sound control, fatigue endurance, and impact resistance. The physical aging effects are quantified based on a set of creep curves measured at different aging time or different aging temperature. One parameter (tau) curve fit was proposed to represent the relationship of aging time and aging temperature between different master curves. The long term mechanical behavior was predicted by obtained master curves. The time and temperature shift factors of matrix were obtained from creep curves and the aging time shift rate were calculated. The aging effects on composite are obtained from experiments and compared with prediction. The mechanical quasi-behavior of MDC composite was analyzed. The correspondence principle was used to relate quasi-static elastic properties of composite materials to time-dependent properties of its constituent materials (i.e., fiber and matrix). The Prony series combined with the multi-data fitting method was applied to inverse Laplace transform and to calculate the time dependent stiffness matrix effectively. Accelerated time-dependent deformation of two flywheel rim designs were studied for a period equivalent to 31 years and are compared with hoop reinforcement only composite. Damping of pure resin and T700/epoxy composite lamina and laminate in longitudinal and transverse directions were investigated experimentally and analytically. The effect of aging on damping was also studied by placing samples at 60°C in an oven for extended periods. Damping master curves versus frequency were constructed from individual curves at different temperatures based on the Arrhenius equation. The damping response of the composite lamina was used to predict the response of laminate composites. Analytical results give close numerical values to experimental results from damping of cantilever beam laminated composite samples.

Information Retrieval System for Japanese Standard Disease-Code Master Using XML Web Service

PubMed Central

Hatano, Kenji; Ohe, Kazuhiko

2003-01-01

Information retrieval system of Japanese Standard Disease-Code Master Using XML Web Service is developed. XML Web Service is a new distributed processing system by standard internet technologies. With seamless remote method invocation of XML Web Service, users are able to get the latest disease code master information from their rich desktop applications or internet web sites, which refer to this service. PMID:14728364

A geometry-based approach to determining time-temperature superposition shifts in aging experiments

DOE PAGES

Maiti, Amitesh

2015-12-21

A powerful way to expand the time and frequency range of material properties is through a method called time-temperature superposition (TTS). Traditionally, TTS has been applied to the dynamical mechanical and flow properties of thermo-rheologically simple materials, where a well-defined master curve can be objectively and accurately obtained by appropriate shifts of curves at different temperatures. However, TTS analysis can also be useful in many other situations where there is scatter in the data and where the principle holds only approximately. In such cases, shifting curves can become a subjective exercise and can often lead to significant errors in themore » long-term prediction. This mandates the need for an objective method of determining TTS shifts. Here, we adopt a method based on minimizing the “arc length” of the master curve, which is designed to work in situations where there is overlapping data at successive temperatures. We examine the accuracy of the method as a function of increasing noise in the data, and explore the effectiveness of data smoothing prior to TTS shifting. In conclusion, we validate the method using existing experimental data on the creep strain of an aramid fiber and the powder coarsening of an energetic material.« less

The learning curve of laparoscopic holecystectomy in general surgery resident training: old age of the patient may be a risk factor?

PubMed

Ferrarese, Alessia; Gentile, Valentina; Bindi, Marco; Rivelli, Matteo; Cumbo, Jacopo; Solej, Mario; Enrico, Stefano; Martino, Valter

2016-01-01

A well-designed learning curve is essential for the acquisition of laparoscopic skills: but, are there risk factors that can derail the surgical method? From a review of the current literature on the learning curve in laparoscopic surgery, we identified learning curve components in video laparoscopic cholecystectomy; we suggest a learning curve model that can be applied to assess the progress of general surgical residents as they learn and master the stages of video laparoscopic cholecystectomy regardless of type of patient. Electronic databases were interrogated to better define the terms "surgeon", "specialized surgeon", and "specialist surgeon"; we surveyed the literature on surgical residency programs outside Italy to identify learning curve components, influential factors, the importance of tutoring, and the role of reference centers in residency education in surgery. From the definition of acceptable error, self-efficacy, and error classification, we devised a learning curve model that may be applied to training surgical residents in video laparoscopic cholecystectomy. Based on the criteria culled from the literature, the three surgeon categories (general, specialized, and specialist) are distinguished by years of experience, case volume, and error rate; the patients were distinguished for years and characteristics. The training model was constructed as a series of key learning steps in video laparoscopic cholecystectomy. Potential errors were identified and the difficulty of each step was graded using operation-specific characteristics. On completion of each procedure, error checklist scores on procedure-specific performance are tallied to track the learning curve and obtain performance indices of measurement that chart the trainee's progress. The concept of the learning curve in general surgery is disputed. The use of learning steps may enable the resident surgical trainee to acquire video laparoscopic cholecystectomy skills proportional to the instructor's ability, the trainee's own skills, and the safety of the surgical environment. There were no patient characteristics that can derail the methods. With this training scheme, resident trainees may be provided the opportunity to develop their intrinsic capabilities without the loss of basic technical skills.

New Korean reference for birth weight by gestational age and sex: data from the Korean Statistical Information Service (2008-2012).

PubMed

Lim, Jung Sub; Lim, Se Won; Ahn, Ju Hyun; Song, Bong Sub; Shim, Kye Shik; Hwang, Il Tae

2014-09-01

To construct new Korean reference curves for birth weight by sex and gestational age using contemporary Korean birth weight data and to compare them with the Lubchenco and the 2010 United States (US) intrauterine growth curves. Data of 2,336,727 newborns by the Korean Statistical Information Service (2008-2012) were used. Smoothed percentile curves were created by the Lambda Mu Sigma method using subsample of singleton. The new Korean reference curves were compared with the Lubchenco and the 2010 US intrauterine growth curves. Reference of the 3rd, 10th, 25th, 50th, 75th, 90th, and 97th percentiles birth weight by gestational age were made using 2,249,804 (male, 1,159,070) singleton newborns with gestational age 23-43 weeks. Separate birth weight curves were constructed for male and female. The Korean reference curves are similar to the 2010 US intrauterine growth curves. However, the cutoff values for small for gestational age (<10th percentile) of the new Korean curves differed from those of the Lubchenco curves for each gestational age. The Lubchenco curves underestimated the percentage of infants who were born small for gestational age. The new Korean reference curves for birth weight show a different pattern from the Lubchenco curves, which were made from white neonates more than 60 years ago. Further research on short-term and long-term health outcomes of small for gestational age babies based on the new Korean reference data is needed.

Nondimensional scaling of magnetorheological rotary shear mode devices using the Mason number

NASA Astrophysics Data System (ADS)

Becnel, Andrew C.; Sherman, Stephen; Hu, Wei; Wereley, Norman M.

2015-04-01

Magnetorheological fluids (MRFs) exhibit rapidly adjustable viscosity in the presence of a magnetic field, and are increasingly used in adaptive shock absorbers for high speed impacts, corresponding to high fluid shear rates. However, the MRF properties are typically measured at very low (γ ˙<1000 s-1) shear rates due to limited commercial rheometer capabilities. A custom high shear rate (γ ˙>10,000 s-1) Searle cell magnetorheometer, along with a full scale rotary-vane magnetorheological energy absorber (γ ˙>25,000 s-1) are employed to analyze MRF property scaling across shear rates using a nondimensional Mason number to generate an MRF master curve. Incorporating a Reynolds temperature correction factor, data from both experiments is shown to collapse to a single master curve, supporting the use of Mason number to correlate low- and high-shear rate characterization data.

75 FR 34526 - Petition for Waiver of Compliance

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-17

... transceivers use a master reference oscillator to determine the frequency stability of the transmitted signal... if the transmitted signal is not on frequency. The master oscillator, itself, is specified to a much..., the modulation circuitry used in the DTX radios is based upon very stable limiting operational...

Determination of dynamic modulus master curves for Oklahoma HMA mixtures.

DOT National Transportation Integrated Search

2007-12-01

The Mechanistic-Empirical Pavement Design Guide (M-EPDG) uses a hierarchical approach with three : levels of material characterization for asphalt materials. The first level provides the highest design : reliability and each succeeding level is a dro...

Ferment in Business Education: E-Commerce Master's Programs.

ERIC Educational Resources Information Center

Durlabhji, Subhash; Fusilier, Marcelline R.

2002-01-01

A review of curriculum and course descriptions of 67 Web-based electronic commerce master's programs showed that the number of programs grew 76% over 8 months. More nontechnical than technology-centered courses are offered. Business schools are apparently viewing e-commerce as a completely new discipline. (Contains 26 references.) (SK)

Transparency Master: The Annual Aphid Cycle.

ERIC Educational Resources Information Center

Sessions, Mary Lynne

1983-01-01

Aphids, often referred to as plant lice, can be found in great numbers on stems, leaves, and flowers of many plants. In many cases these organisms are potentially harmful to their plant hosts. Provided is a description of the annual life cycle of the aphid and an accompanying transparency master. (Author/JN)

Numerical simulation of photocurrent generation in bilayer organic solar cells: Comparison of master equation and kinetic Monte Carlo approaches

NASA Astrophysics Data System (ADS)

Casalegno, Mosè; Bernardi, Andrea; Raos, Guido

2013-07-01

Numerical approaches can provide useful information about the microscopic processes underlying photocurrent generation in organic solar cells (OSCs). Among them, the Kinetic Monte Carlo (KMC) method is conceptually the simplest, but computationally the most intensive. A less demanding alternative is potentially represented by so-called Master Equation (ME) approaches, where the equations describing particle dynamics rely on the mean-field approximation and their solution is attained numerically, rather than stochastically. The description of charge separation dynamics, the treatment of electrostatic interactions and numerical stability are some of the key issues which have prevented the application of these methods to OSC modelling, despite of their successes in the study of charge transport in disordered system. Here we describe a three-dimensional ME approach to photocurrent generation in OSCs which attempts to deal with these issues. The reliability of the proposed method is tested against reference KMC simulations on bilayer heterojunction solar cells. Comparison of the current-voltage curves shows that the model well approximates the exact result for most devices. The largest deviations in current densities are mainly due to the adoption of the mean-field approximation for electrostatic interactions. The presence of deep traps, in devices characterized by strong energy disorder, may also affect result quality. Comparison of the simulation times reveals that the ME algorithm runs, on the average, one order of magnitude faster than KMC.

Development of asphalt dynamic modulus master curve using falling weight deflectometer measurements.

DOT National Transportation Integrated Search

2014-06-01

The asphalt concrete (AC) dynamic modulus (|E*|) is a key design parameter in mechanistic-based pavement design : methodologies such as the American Association of State Highway and Transportation Officials (AASHTO) MEPDG/Pavement-ME Design. The obje...

Preparation of silicon target material by adding Al-B master alloy in directional solidification

NASA Astrophysics Data System (ADS)

Li, Pengting; Wang, Kai; Ren, Shiqiang; Jiang, Dachuan; Tan, Yi

2017-03-01

The silicon target material was prepared by adding Al-6B master alloy in directional solidification. The microstructure was characterized and the resistivity was studied in this work. The results showed that the purity of the silicon target material was more than 99.999% (5N). The resistivity was ranges from 0.002 to 0.030 Ω·cm along the ingot height. It was revealed that the particles of AlB2 in Al-6B master alloy would react spontaneously and generate clusters of [B] and [Al] in molten silicon at 1723 K. After directional solidification, the content of B and Al were increasing gradually with the increase of solidified fraction. The measured values of B were in good agreement with the curve of the Scheil equation below 80% of the ingot height. The mean concentration of B was about 17.20 ppmw and the mean concentration of Al was about 8.07 ppmw after directional solidification. The measured values of Al were fitting well with the curve of values which the effective segregation coefficient was 0.00378. It was observed that B co-doped Al in directional solidification polysilicon could regulate resistivity mutually. This work provides the theoretical basis and technical support for industrial production of the silicon target material.

PROBLEMS OF AMERICANS IN MASTERING THE PRONUNCIATION OF EGYPTIAN ARABIC.

ERIC Educational Resources Information Center

KENNEDY, NANCY M.

THE DIFFICULTIES ENCOUNTERED BY SPEAKERS OF AMERICAN ENGLISH IN ATTEMPTING TO MASTER THE PRONUNCIATION OF EGYPTIAN ARABIC WERE ANALYZED DURING THE REPORTED RESEARCH. THE LANGUAGE UNDER CONSIDERATION WAS THE URBAN COLLOQUIAL ARABIC OF THE EGYPTIAN DELTA. THIS STUDY DEALT WITH THE SEGMENTAL PHONEMES ONLY, WITH SOME REFERENCE TO STRESS AND…

Magnetic-sensor performance evaluated from magneto-conductance curve in magnetic tunnel junctions using in-plane or perpendicularly magnetized synthetic antiferromagnetic reference layers

NASA Astrophysics Data System (ADS)

Nakano, T.; Oogane, M.; Furuichi, T.; Ando, Y.

2018-04-01

The automotive industry requires magnetic sensors exhibiting highly linear output within a dynamic range as wide as ±1 kOe. A simple model predicts that the magneto-conductance (G-H) curve in a magnetic tunnel junction (MTJ) is perfectly linear, whereas the magneto-resistance (R-H) curve inevitably contains a finite nonlinearity. We prepared two kinds of MTJs using in-plane or perpendicularly magnetized synthetic antiferromagnetic (i-SAF or p-SAF) reference layers and investigated their sensor performance. In the MTJ with the i-SAF reference layer, the G-H curve did not necessarily show smaller nonlinearities than those of the R-H curve with different dynamic ranges. This is because the magnetizations of the i-SAF reference layer start to rotate at a magnetic field even smaller than the switching field (Hsw) measured by a magnetometer, which significantly affects the tunnel magnetoresistance (TMR) effect. In the MTJ with the p-SAF reference layer, the G-H curve showed much smaller nonlinearities than those of the R-H curve, thanks to a large Hsw value of the p-SAF reference layer. We achieved a nonlinearity of 0.08% FS (full scale) in the G-H curve with a dynamic range of ±1 kOe, satisfying our target for automotive applications. This demonstrated that a reference layer exhibiting a large Hsw value is indispensable in order to achieve a highly linear G-H curve.

38 CFR 39.32 - Plan preparation.

Code of Federal Regulations, 2011 CFR

2011-07-01

... a previously approved project and there have been no changes. Relevant information may then be shown... having other change or direction between corners) shall be referenced with curve data (including... indicated. The master plan shall analyze all factors affecting the design, including climate, soil...

Econophysics: Master curve for price-impact function

NASA Astrophysics Data System (ADS)

Lillo, Fabrizio; Farmer, J. Doyne; Mantegna, Rosario N.

2003-01-01

The price reaction to a single transaction depends on transaction volume, the identity of the stock, and possibly many other factors. Here we show that, by taking into account the differences in liquidity for stocks of different size classes of market capitalization, we can rescale both the average price shift and the transaction volume to obtain a uniform price-impact curve for all size classes of firm for four different years (1995-98). This single-curve collapse of the price-impact function suggests that fluctuations from the supply-and-demand equilibrium for many financial assets, differing in economic sectors of activity and market capitalization, are governed by the same statistical rule.

First reference curves of waist and hip circumferences in an Asian population of youths: CASPIAN study.

PubMed

Kelishadi, Roya; Gouya, Mohammad Mehdi; Ardalan, Gelayol; Hosseini, Mohsen; Motaghian, Molouk; Delavari, Alireza; Majdzadeh, Reza; Heidarzadeh, Abtin; Mahmoud-Arabi, Minou Sadat; Riazi, Mohammad Mehdi

2007-06-01

The Objective of the present study is to develop the first age- and gender-specific reference curves for waist and hip circumferences in an Asian population of youths. This cross-sectional population survey was conducted in 2003-04 on a nationally representative sample of 21111 school-students living in urban (84.6%) and rural (15.4%) areas of 23 provinces in Iran. After anthropometric measurements, smoothed reference curves for waist and hip circumference (WC, HiC) and waist-to-hip ratio (WHR) were developed by the LMS method. In both genders, WC and HiC percentile values increased with age. For girls, the 50th to 95th percentile curves for WC had a sharp increase between 8 and 13 years and 11-15 years, respectively, and began to plateau after this age, whereas for boys, these curves had a persistent and less sharp increase with age, until the age of 18 years. The WHR curves of girls decreased with age until 15 years and began to plateau thereafter, whereas for boys the 25th to 95th curves had a plateau pattern. Comparison of the current reference curves with the British ones showed that in boys, the 5th and 50th percentile curves were similar in both studies, but the 95th percentile curve of our study was higher than the British curves. For girls, the 5th percentile curves of both studies were similar, but the 50th and 95th percentile curves of our study were higher than the British ones. These curves represent the first childhood WC, HiC and WHR reference curves obtained in Asia. These curves can provide baseline data for analysis of time trends, as well as for international comparisons.

Cultural Terrain -- Mapping out the Future

DTIC Science & Technology

2007-01-01

Quantico, Virginia 22134-5068 MASTER OF OPERATIONAL STUDIES TITLE: CULTURAL TERRAIN – MAPPING OUT THE FUTURE SUBMITTED IN PARTIAL...FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF OPERATIONAL STUDIES AUTHOR: MAJOR DANIEL A. SCHMITT, UNITED STATES MARINE CORPS...GOVERNMENTAL AGENCY. REFERENCES TO THIS STUDY SHOULD INCLUDE THE FOREGOING STATEMENT. QUOTATION FROM, ABSTRACTION FROM, OR REPRODUCTION OF ALL OR ANY

Relative Age Effect in Masters Sports: Replication and Extension

ERIC Educational Resources Information Center

Medic, Nikola; Starkes, Janet L.; Weir, Patricia L.; Young, Bradley W.; Grove, J. Robert

2009-01-01

The relative age effect refers to the performance-related advantage of being born early in a cohort or selection year. Until recently it was unknown whether the relative age effect generalizes across the lifespan. Medic, Starkes, and Young (2007) reasoned that the 5-year age categories that are widely used in masters-level sports to organize…

Non-Boltzmann Modeling for Air Shock-Layer Radiation at Lunar-Return Conditions

NASA Technical Reports Server (NTRS)

Johnston, Christopher O.; Hollis, Brian R.; Sutton, Kenneth

2008-01-01

This paper investigates the non-Boltzmann modeling of the radiating atomic and molecular electronic states present in lunar-return shock-layers. The Master Equation is derived for a general atom or molecule while accounting for a variety of excitation and de-excitation mechanisms. A new set of electronic-impact excitation rates is compiled for N, O, and N2+, which are the main radiating species for most lunar-return shock-layers. Based on these new rates, a novel approach of curve-fitting the non-Boltzmann populations of the radiating atomic and molecular states is developed. This new approach provides a simple and accurate method for calculating the atomic and molecular non-Boltzmann populations while avoiding the matrix inversion procedure required for the detailed solution of the Master Equation. The radiative flux values predicted by the present detailed non-Boltzmann model and the approximate curve-fitting approach are shown to agree within 5% for the Fire 1634 s case.

A critical evaluation of theories for predicting microcracking in composite laminates

NASA Technical Reports Server (NTRS)

Nairn, John A.; Hu, Shoufeng; Bark, Jong S.

1993-01-01

We present experimental results on 21 different layups of Hercules AS4 carbon fiber/3501-6 epoxy laminates. All laminates had 90 deg plies; some had them in the middle, while some had them on a free surface. During tensile loading, the first form of damage in all laminates was microcracking of the 90 deg plies. For each laminate, we recorded both the crack density and the complete distribution of crack spacings as a function of the applied load. By rearranging various microcracking theories, we developed a master-curve approach that permitted plotting the results from all laminates on a single plot. By comparing master-curve plots for different theories, it was possible to critically evaluate the quality of those theories. We found that a critical-energy-release-rate criterion calculated using a 2D variational stress analysis gave the best results. All microcracking theories based on a strength-failure criteria gave poor results. All microcracking theories using 1D stress analyses, regardless of the failure criterion, also gave poor results.

A fractional model with parallel fractional Maxwell elements for amorphous thermoplastics

NASA Astrophysics Data System (ADS)

Lei, Dong; Liang, Yingjie; Xiao, Rui

2018-01-01

We develop a fractional model to describe the thermomechanical behavior of amorphous thermoplastics. The fractional model is composed of two parallel fractional Maxwell elements. The first fractional Maxwell model is used to describe the glass transition, while the second component is aimed at describing the viscous flow. We further derive the analytical solutions for the stress relaxation modulus and complex modulus through Laplace transform. We then demonstrate the model is able to describe the master curves of the stress relaxation modulus, storage modulus and loss modulus, which all show two distinct transition regions. The obtained parameters show that the modulus of the two fractional Maxwell elements differs in 2-3 orders of magnitude, while the relaxation time differs in 7-9 orders of magnitude. Finally, we apply the model to describe the stress response of constant strain rate tests. The model, together with the parameters obtained from fitting the master curve of stress relaxation modulus, can accurately predict the temperature and strain rate dependent stress response.

Linear and nonlinear mechanical properties of a series of epoxy resins

NASA Technical Reports Server (NTRS)

Curliss, D. B.; Caruthers, J. M.

1987-01-01

The linear viscoelastic properties have been measured for a series of bisphenol-A-based epoxy resins cured with the diamine DDS. The linear viscoelastic master curves were constructed via time-temperature superposition of frequency dependent G-prime and G-double-prime isotherms. The G-double-prime master curves exhibited two sub-Tg transitions. Superposition of isotherms in the glass-to-rubber transition (i.e., alpha) and the beta transition at -60 C was achieved by simple horizontal shifts in the log frequency axis; however, in the region between alpha and beta, superposition could not be effected by simple horizontal shifts along the log frequency axis. The different temperature dependency of the alpha and beta relaxation mechanisms causes a complex response of G-double-prime in the so called alpha-prime region. A novel numerical procedure has been developed to extract the complete relaxation spectra and its temperature dependence from the G-prime and G-double-prime isothermal data in the alpha-prime region.

Secure SCADA communication by using a modified key management scheme.

PubMed

Rezai, Abdalhossein; Keshavarzi, Parviz; Moravej, Zahra

2013-07-01

This paper presents and evaluates a new cryptographic key management scheme which increases the efficiency and security of the Supervisory Control And Data Acquisition (SCADA) communication. In the proposed key management scheme, two key update phases are used: session key update and master key update. In the session key update phase, session keys are generated in the master station. In the master key update phase, the Elliptic Curve Diffie-Hellman (ECDH) protocol is used. The Poisson process is also used to model the Security Index (SI) and Quality of Service (QoS). Our analysis shows that the proposed key management not only supports the required speed in the MODBUS implementation but also has several advantages compared to other key management schemes for secure communication in SCADA networks. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

Influence of tray rigidity and impression technique on accuracy of polyvinyl siloxane impressions.

PubMed

Hoyos, Alex; Soderholm, Karl-Johan

2011-01-01

The aim of this study was to determine how tray rigidity and impression technique affect the accuracy of polyvinyl siloxane impressions. Disposable plastic trays and metallic Rim-Lock trays were used in combination with a heavy/light body technique or with two different putty-wash techniques. For each technique-tray combination, 10 impressions were made of a master cast with two steel abutments representing the mandibular right first premolar and second molar, between which a steel rod was placed at the ridge level. Each steel abutment had five marks, while the steel rod in between the two abutments had only one mark, which served as a reference point. With a universal measuring microscope, the x-, y-, and z-coordinates were recorded for each mark on the master cast and impressions. The distances between the different marks and the reference point on the impressions were calculated and compared with those of the master cast. All techniques used with the plastic trays had distances that were significantly different from the master cast (P < .05), while for the metal trays, it was only the heavy/light body technique that resulted in distances that were significantly different from the master cast (P < .05). Plastic trays produced less accurate impressions than metal trays. When metal trays were used, putty-based impressions were dimensionally better than heavy/light body impressions.

Experimental Observation of Two Features Unexpected from the Classical Theories of Rubber Elasticity

NASA Astrophysics Data System (ADS)

Nishi, Kengo; Fujii, Kenta; Chung, Ung-il; Shibayama, Mitsuhiro; Sakai, Takamasa

2017-12-01

Although the elastic modulus of a Gaussian chain network is thought to be successfully described by classical theories of rubber elasticity, such as the affine and phantom models, verification experiments are largely lacking owing to difficulties in precisely controlling of the network structure. We prepared well-defined model polymer networks experimentally, and measured the elastic modulus G for a broad range of polymer concentrations and connectivity probabilities, p . In our experiment, we observed two features that were distinct from those predicted by classical theories. First, we observed the critical behavior G ˜|p -pc|1.95 near the sol-gel transition. This scaling law is different from the prediction of classical theories, but can be explained by analogy between the electric conductivity of resistor networks and the elasticity of polymer networks. Here, pc is the sol-gel transition point. Furthermore, we found that the experimental G -p relations in the region above C* did not follow the affine or phantom theories. Instead, all the G /G0-p curves fell onto a single master curve when G was normalized by the elastic modulus at p =1 , G0. We show that the effective medium approximation for Gaussian chain networks explains this master curve.

The Shorewood Collection Art Reference Guide.

ERIC Educational Resources Information Center

1992

This reference guide contains a descriptive critique of each of more than 900 images of paintings and drawings presented in "The Shorewood Collection." This guide is intended to be used as a reference tool in conjunction with Shorewood's art educational programs, which range from grade levels K through 12. Master works from major epochs in the…

National Nutrition Education Clearing House Reference List, Secondary Teaching Materials and Teacher References.

ERIC Educational Resources Information Center

National Nutrition Education Clearing House, Berkeley, CA.

A reference list of teaching materials and teacher guides in the field of nutrition is compiled in this pamphlet. Primary emphasis is on resources for secondary grades. The section on teaching materials includes books, pamphlets, leaflets, posters, charts, transparencies, ditto masters, kits, games, films, filmstrips, records, TV videotapes, and…

Journal Use by Graduate Students as Indicated by Master's Theses Bibliographies at an Urban Commuter College, 1991-2004

ERIC Educational Resources Information Center

Sexton, Ellen

2006-01-01

Citation analyses were carried out on master's theses in three disciplines: forensic psychology, forensic science, and criminal justice, completed and deposited in the John Jay College Library from 1991 to 2004. The aim was to determine the effect of availability of electronic journals on students' choice of references. The number of journal…

Annotated Bibliography on Transition from School to Work (1985-1991). Master Index to Volumes 1-6.

ERIC Educational Resources Information Center

Harmon, Adrienne S., Comp.

This master index provides access by title, author, and subject descriptors to items described in the first six volumes of the "Annotated Bibliography on Transition from School to Work." Volumes 1 through 6 of the bibliography annotates over 2,400 references on topics related to transition of individuals with disabilities. Examples of topics…

Effects of Work Environment on Transfer of Training: Empirical Evidence from Master of Business Administration Programs in Vietnam

ERIC Educational Resources Information Center

Pham, Nga T. P.; Segers, Mien S. R.; Gijselaers, Wim H.

2013-01-01

Practical application of newly gained knowledge and skills, also referred to as transfer of training, is an issue of great concern in training issues generally and in Master of Business Administration (MBA) programs particularly. This empirical study examined the influence of the trainees' work environment on their transfer of training, taking…

Cultural Terrain - Mapping Out the Future

DTIC Science & Technology

2007-01-01

Quantico, Virginia 22134-5068 MASTER OF OPERATIONAL STUDIES TITLE: CULTURAL TERRAIN – MAPPING OUT THE FUTURE SUBMITTED IN PARTIAL...FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF OPERATIONAL STUDIES AUTHOR: MAJOR DANIEL A. SCHMITT, UNITED STATES MARINE CORPS...AGENCY. REFERENCES TO THIS STUDY SHOULD INCLUDE THE FOREGOING STATEMENT. QUOTATION FROM, ABSTRACTION FROM, OR REPRODUCTION OF ALL OR ANY PART OF

Considering the Influence of Prerequisite Performance on Wheel Spinning

ERIC Educational Resources Information Center

Wan, Hao; Beck, Joseph Barbosa

2015-01-01

The phenomenon of wheel spinning refers to students attempting to solve problems on a particular skill, but becoming stuck due to an inability to learn the skill. Past research has found that students who do not master a skill quickly tend not to master it at all. One question is why do students wheel spin? A plausible hypothesis is that students…

Elongational viscosity of photo-oxidated LDPE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rolón-Garrido, Víctor H., E-mail: victor.h.rolongarrido@tu-berlin.de, E-mail: manfred.wagner@tu-berlin.de; Wagner, Manfred H., E-mail: victor.h.rolongarrido@tu-berlin.de, E-mail: manfred.wagner@tu-berlin.de

2014-05-15

Sheets of low-density polyethylene (LDPE) were photo-oxidatively treated at room temperature, and subsequently characterized rheologically in the melt state by shear and uniaxial extensional experiments. For photo-oxidation, a xenon lamp was used to irradiate the samples for times between 1 day and 6 weeks. Linear-viscoelastic characterization was performed in a temperature range of 130 to 220°C to obtain the master curve at 170°C, the reference temperature at which the elongational viscosities were measured. Linear viscoelasticity is increasingly affected by increasing photo-oxidation due to crosslinking of LDPE, as corroborated by an increasing gel fraction as determined by a solvent extraction method.more » The elongational measurements reveal a strong enhancement of strain hardening until a saturation level is achieved. The elongational data are analyzed in the frame work of two constitutive equations, the rubber-like liquid and the molecular stress function models. Within the experimental window, timedeformation separability is confirmed for all samples, independent of the degree of photo-oxidation.« less

Framework for analyzing hyper-viscoelastic polymers

NASA Astrophysics Data System (ADS)

Trivedi, Akash; Siviour, Clive

2017-06-01

Hyper-viscoelastic polymers have multiple areas of application including aerospace, biomedicine, and automotive. Their mechanical responses are therefore extremely important to understand, particularly because they exhibit strong rate and temperature dependence, including a low temperature brittle transition. Relationships between the response at various strain rates and temperatures are investigated and a framework developed to predict response at rates where experiments are unfeasible. A master curve of the storage modulus's rate dependence at a reference temperature is constructed using a DMA test of the polymer. A frequency sweep spanning two decades and a temperature range from pre-glass transition to pre-melt is used. A fractional derivative model is fitted to the experimental data, and this model's parameters are used to derive stress-strain relationships at a desired strain rate. Finite element simulations with this constitutive model are used for verification with experimental data. This material is based upon work supported by the Air Force Office of Scientific Research, Air Force Materiel Command, USAF under Award No. FA9550-15-1-0448.

Free volume study on the miscibility of PEEK/PEI blend using positron annihilation and dynamic mechanical thermal analysis

NASA Astrophysics Data System (ADS)

Ramani, R.; Alam, S.

2015-06-01

High performance polymer blend of poly(ether ether ketone) (PEEK) and poly(ether imide) (PEI) was examined for their free volume behaviour using positron annihilation lifetime spectroscopy and dynamic mechanical thermal analysis methods. The fractional free volume obtained from PALS shows a negative deviation from linear additivity rule implying good miscibility between PEEK and PEI. The dynamic modulus and loss tangent were obtained for the blends at three different frequencies 1, 10 and 100 Hz at temperatures close to and above their glass transition temperature. Applying Time-Temperature-Superposition (TTS) principle to the DMTA results, master curves were obtained at a reference temperature To and the WLF coefficients c01 and c02 were evaluated. Both the methods give similar results for the dependence of fractional free volume on PEI content in this blend. The results reveal that free volume plays an important role in determining the visco-elastic properties in miscible polymer blends.

Photo-oxidation of LDPE: Effects on elongational viscosity

NASA Astrophysics Data System (ADS)

Rolón-Garrido, Víctor H.; Wagner, Manfred H.

2013-04-01

Sheets of low-density polyethylene (LDPE) were photo-oxidatively treated at room temperature, and subsequently characterized rheologically in the melt state by shear and uniaxial extensional experiments. For photo-oxidation, a xenon lamp was used to irradiate the samples for times between 1 day and 6 weeks. Linear-viscoelastic characterization was performed in a temperature range of 130 to 220°C to obtain the master curve at 170°C, the reference temperature at which the elongational viscosities were measured. Linear viscoelasticity is increasingly affected by increasing photo-oxidation due to crosslinking of LDPE, as corroborated by an increasing gel fraction as determined by a solvent extraction method. The elongational measurements reveal a strong enhancement of strain hardening until a saturation level is achieved. The elongational data are analyzed in the frame work of two constitutive equations, the rubber-like liquid and the molecular stress function models. Within the experimental window, time-deformation separability is confirmed for all samples, independent of the degree of photo-oxidation.

Elongational viscosity of photo-oxidated LDPE

NASA Astrophysics Data System (ADS)

Rolón-Garrido, Víctor H.; Wagner, Manfred H.

2014-05-01

Sheets of low-density polyethylene (LDPE) were photo-oxidatively treated at room temperature, and subsequently characterized rheologically in the melt state by shear and uniaxial extensional experiments. For photo-oxidation, a xenon lamp was used to irradiate the samples for times between 1 day and 6 weeks. Linear-viscoelastic characterization was performed in a temperature range of 130 to 220°C to obtain the master curve at 170°C, the reference temperature at which the elongational viscosities were measured. Linear viscoelasticity is increasingly affected by increasing photo-oxidation due to crosslinking of LDPE, as corroborated by an increasing gel fraction as determined by a solvent extraction method. The elongational measurements reveal a strong enhancement of strain hardening until a saturation level is achieved. The elongational data are analyzed in the frame work of two constitutive equations, the rubber-like liquid and the molecular stress function models. Within the experimental window, timedeformation separability is confirmed for all samples, independent of the degree of photo-oxidation.

Common View Time Transfer Using Worldwide GPS and DMA Monitor Stations

NASA Technical Reports Server (NTRS)

Reid, Wilson G.; McCaskill, Thomas B.; Oaks, Orville J.; Buisson, James A.; Warren, Hugh E.

1996-01-01

Analysis of the on-orbit Navstar clocks and the Global Positioning System (GPS) monitor station reference clocks is performed by the Naval Research Laboratory using both broadcast and postprocessed precise ephemerides. The precise ephemerides are produced by the Defense Mapping Agency (DMA) for each of the GPS space vehicles from pseudo-range measurements collected at five GPS and at five DMA monitor stations spaced around the world. Recently, DMA established an additional site co-located with the US Naval Observatory precise time site. The time reference for the new DMA site is the DoD Master Clock. Now, for the first time, it is possible to transfer time every 15 minutes via common view from the DoD Master Clock to the 11 GPS and DMA monitor stations. The estimated precision of a single common-view time transfer measurement taken over a 15-minute interval was between 1.4 and 2.7 nanoseconds. Using the measurements from all Navstar space vehicles in common view during the 15-minute interval, typically 3-7 space vehicles, improved the estimate of the precision to between 0.65 and 1.13 nanoseconds. The mean phase error obtained from closure of the time transfer around the world using the 11 monitor stations and the 25 space vehicle clocks over a period of 4 months had a magnitude of 31 picoseconds. Analysis of the low noise time transfer from the DoD Master Clock to each of the monitor stations yields not only the bias in the time of the reference clock, but also focuses attention on structure in the behaviour of the reference clock not previously seen. Furthermore, the time transfer provides a a uniformly sampled database of 15-minute measurements that make possible, for the first time, the direct and exhaustive computation of the frequency stability of the monitor station reference clocks. To lend perspective to the analysis, a summary is given of the discontinuities in phase and frequency that occurred in the reference clock at the Master Control Station during the period covered by the analysis.

Master curve captures the effect of domain morphology on ethanol pervaporation through block copolymer membranes

USDA-ARS?s Scientific Manuscript database

We report on the effect of changing nanoscale morphology on pervaporation of ethanol/water mixtures through block copolymer membranes. Experiments were conducted using polystyrene-b-polybutadiene-b-polystyrene (SBS) copolymers with polybutadiene (PB) as the ethanol transporting block, using an 8 wt%...

Preschool children master the logic of number word meanings.

PubMed

Lipton, Jennifer S; Spelke, Elizabeth S

2006-01-01

Although children take over a year to learn the meanings of the first three number words, they eventually master the logic of counting and the meanings of all the words in their count list. Here, we ask whether children's knowledge applies to number words beyond those they have mastered: Does a child who can only count to 20 infer that number words above 'twenty' refer to exact cardinal values? Three experiments provide evidence for this understanding in preschool children. Before beginning formal education or gaining counting skill, children possess a productive symbolic system for representing number.

Mentorship, learning curves, and balance.

PubMed

Cohen, Meryl S; Jacobs, Jeffrey P; Quintessenza, James A; Chai, Paul J; Lindberg, Harald L; Dickey, Jamie; Ungerleider, Ross M

2007-09-01

Professionals working in the arena of health care face a variety of challenges as their careers evolve and develop. In this review, we analyze the role of mentorship, learning curves, and balance in overcoming challenges that all such professionals are likely to encounter. These challenges can exist both in professional and personal life. As any professional involved in health care matures, complex professional skills must be mastered, and new professional skills must be acquired. These skills are both technical and judgmental. In most circumstances, these skills must be learned. In 2007, despite the continued need for obtaining new knowledge and learning new skills, the professional and public tolerance for a "learning curve" is much less than in previous decades. Mentorship is the key to success in these endeavours. The success of mentorship is two-sided, with responsibilities for both the mentor and the mentee. The benefits of this relationship must be bidirectional. It is the responsibility of both the student and the mentor to assure this bidirectional exchange of benefit. This relationship requires time, patience, dedication, and to some degree selflessness. This mentorship will ultimately be the best tool for mastering complex professional skills and maturing through various learning curves. Professional mentorship also requires that mentors identify and explicitly teach their mentees the relational skills and abilities inherent in learning the management of the triad of self, relationships with others, and professional responsibilities.Up to two decades ago, a learning curve was tolerated, and even expected, while professionals involved in healthcare developed the techniques that allowed for the treatment of previously untreatable diseases. Outcomes have now improved to the point that this type of learning curve is no longer acceptable to the public. Still, professionals must learn to perform and develop independence and confidence. The responsibility to meet this challenge without a painful learning curve belongs to both the younger professionals, who must progress through the learning curve, and the more mature professionals who must create an appropriate environment for learning. In addition to mentorship, the detailed tracking of outcomes is an essential tool for mastering any learning curve. It is crucial to utilize a detailed database to track outcomes, to learn, and to protect both yourself and your patients. It is our professional responsibility to engage in self-evaluation, in part employing voluntary sharing of data. For cardiac surgical subspecialties, the databases now existing for The European Association for CardioThoracic Surgery and The Society of Thoracic Surgeons represent the ideal tool for monitoring outcomes. Evolving initiatives in the fields of paediatric cardiology, paediatric critical care, and paediatric cardiac anaesthesia will play similar roles.A variety of professional and personal challenges must be met by all those working in health care. The acquisition of learned skills, and the use of special tools, will facilitate the process of conquering these challenges. Choosing appropriate role models and mentors can help progression through any learning curve in a controlled and protected fashion. Professional and personal satisfaction are both necessities. Finding the satisfactory balance between work and home life is difficult, but possible with the right tools, organization skills, and support system at work and at home. The concepts of mentorship, learning curves and balance cannot be underappreciated.

National Health and Nutrition Examination Survey whole-body dual-energy X-ray absorptiometry reference data for GE Lunar systems.

PubMed

Fan, Bo; Shepherd, John A; Levine, Michael A; Steinberg, Dee; Wacker, Wynn; Barden, Howard S; Ergun, David; Wu, Xin P

2014-01-01

The National Health and Nutrition Examination Survey (NHANES 1999-2004) includes adult and pediatric comparisons for total body bone and body composition results. Because dual-energy x-ray absorptiometry (DXA) measurements from different manufacturers are not standardized, NHANES reference values currently are applicable only to a single make and model of Hologic DXA system. The purpose of this study was to derive body composition reference curves for GE Healthcare Lunar DXA systems. Published values from the NHANES 1999-2004 survey were acquired from the Centers for Disease Control and Prevention website. Using previously reported cross-calibration equations between Hologic and GE-Lunar, we converted the total body and regional bone and soft-tissue measurements from NHANES 1999-2004 to GE-Lunar values. The LMS (LmsChartMaker Pro Version 3.5) curve fitting method was used to generate GE-Lunar reference curves. Separate curves were generated for each sex and ethnicity. The reference curves were also divided into pediatric (≤20 years old) and adult (>20 years old) groups. Adult reference curves were derived as a function of age. Additional relationships of pediatric DXA values were derived as a function of height, lean mass, and bone area. Robustness was tested between Hologic and GE-Lunar Z-score values. The NHANES 1999-2004 survey included a sample of 20,672 participants' (9630 female) DXA scans. A total of 8056 participants were younger than 20 yr and were included in the pediatric reference data set. Participants enrolled in the study who weighed more than 136 kg (over scanner table limit) were excluded. The average Z-scores comparing the new GE-Lunar reference curves are close to zero, and the standard deviation of the Z-scores are close to one for all variables. As expected, all measurements on the GE-Lunar reference curves for participants younger than 20 yr increase monotonically with age. In the adult population, most of the curves are constant at younger age and drop moderately as age increases. We have presented NHANES reference curves applicable to DXA whole-body scans acquired on GE Healthcare Lunar systems by age, sex and ethnicity. Users of GE Healthcare GE-Lunar DXA systems can now benefit from the large body composition reference data set collected in the NHANES 1999-2004 study. Copyright © 2014 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

Towards a Reference Curve for the Grades of Each Course

ERIC Educational Resources Information Center

Al-Saleh, Mohammad Fraiwan; Ali, Dareen; Dahshal, Laila

2010-01-01

A grade-reference curve (GRC) can be constructed for any course based on the grades of a course in the last several years. Among other things, the reference curve of a course can be used to test for any abnormality in the current semester's grades of a course. It can be a very important document about the course that serves students, teachers and…

Master curves and radial distribution functions for shear dilatancy of liquid n-hexadecane via nonequilibrium molecular dynamics simulations.

PubMed

Tseng, Huan-Chang; Wu, Jiann-Shing; Chang, Rong-Yeu

2009-04-28

Shear dilatancy, a significant nonlinear behavior of nonequilibrium thermodynamics states, has been observed in nonequilibrium molecular dynamics (NEMD) simulations for liquid n-hexadecane fluid under extreme shear conditions. The existence of shear dilatancy is relevant to the relationship between the imposed shear rate gamma and the critical shear rate gamma(c). Consequently, as gammagamma(c), the intermolecular distance is lengthened substantially by strong shear deformation breaking the equilibrium thermodynamic state so that shear dilatancy takes place. Notably, a characteristic shear rate gamma(m), which depends on the root mean square molecular velocity and the average free molecular distance, is found in nonequilibrium thermodynamics state curves. Studies of the variations in the intermolecular radial distribution function (RDF) with respect to the shear rate provide a direct measure of the variation in the degree of intermolecular separation. Additionally, the variations of the RDF curve in the microscopic regime are consistent with those of the nonequilibrium thermodynamic state in the macroscopic world. By inspecting the overall shape of the RDF curve, it can be readily corroborated that the fluid of interest exists in the liquid state. More importantly, both primary characteristic values, the equilibrium thermodynamic state variable and a particular shear rate of gamma(p), are determined cautiously, with gamma(p) depending on the gamma(m) value and the square root of pressure. Thereby, the nonequilibrium thermodynamic state curves can be normalized as temperature-, pressure-, and density-invariant master curves, formulated by applying the Cross constitutive equation. Clearly, gamma(c) occurs at which a reduced shear rate gamma/gamma(p) approaches 0.1. Furthermore, the trends in the rates of shear dilatancy in both the constant-pressure and constant-volume NEMD systems under isothermal conditions conform to the cyclic rule of pressure, as a function of density and shear rate.

Dynamics of Li+ ions in Li2O-TeO2-P2O5 glasses

NASA Astrophysics Data System (ADS)

Chatterjee, A.; Ghosh, A.

2018-04-01

In the present work we have studied transport properties of lithium ions in 0.3Li2O-0.7[xTeO2-(1-x)P2O5] glasses, where x=0.5, 0.6, 0.7. We have measured acconductivity for a wide range offrequency and temperature. The real part of the conductivity spectra has been analyzed by the power law in Almond-West formalism. The dc conductivity has been obtained from the complex impedance plots. We have found that dc conductivity increases and activation energy decreases on increase of TeO2 for a particular Li2O content. We have also found that the dc conductivity and crossover frequency obey Arrhenius relation. The time temperature superposition has been verified using the scaling formalism of the conductivity spectra. We have found that the conductivity isotherms scaled to a single master curve with suitable scaling parameters for a particular composition at different temperatures. However the scaling to a single master curve fails for different compositions at a particular temperature.

Fracture toughness of irradiated modified 9Cr-1Mo steel

NASA Astrophysics Data System (ADS)

Kim, Sung Ho; Yoon, Ji-Hyun; Ryu, Woo Seog; Lee, Chan Bock; Hong, Jun Hwa

2009-04-01

The effects of irradiation on fracture toughness of modified 9Cr-1Mo steel in the transition region were investigated. Half size precracked Charpy specimens were irradiated up to 1.2 × 10 21n/cm 2 ( E > 0.1 MeV) at 340 °C and 400 °C in the Korean research reactor. The irradiation induced transition temperature shift for a modified 9Cr-1Mo was evaluated by using the Master Curve methodology. The T0 temperature for the unirradiated specimens were measured as -67.7 °C and -72.4 °C from the tests with standard PCVN (precracked charpy V-notch) and half sized PCVN specimens, respectively. The T0 shifts of specimens after irradiation at 340 °C and 400 °C were 70.7 °C and 66.1 °C, respectively. The Weibull slopes for the fracture toughness data obtained from the unirradiated and irradiated modified 9Cr-1Mo steels were determined to confirm the applicability of master curve methodology to modified 9Cr-1Mo steel.

Hydrodynamic entrainment in micro-confined suspensions and its implications for two-point microrheology

NASA Astrophysics Data System (ADS)

Aponte-Rivera, Christian; Zia, Roseanna N.

2017-11-01

We study hydrodynamic entrainment in spherically confined colloidal suspensions of hydrodynamically interacting particles as a model system for intracellular and other micro-confined biophysical transport. Modeling of transport and rheology in such materials requires an accurate description of the microscopic forces driving particle motion and of particle interactions with nearby boundaries. We carry out dynamic simulations of concentrated, spherically confined colloids as a model system to study the effect of 3D confinement on entrainment and rheology. We show that entrainment between two tracer particles exhibits qualitatively different functional dependence on inter-particle separation as compared to an unbound suspension, and develop a scaling theory that collapses the concentrated mobility of spherically confined suspensions for all volume fractions and particle to cavity size ratios onto a master curve. For widely separated particles, the master curve can be predicted via a Green's function, which suggests a framework with which to conduct two-point microrheology measurements near confining boundaries. The implications of these results for experiments in micro-confined biophysical systems, such as the interior of eukaryotic cells, are discussed.

Extension of the master sintering curve for constant heating rate modeling

NASA Astrophysics Data System (ADS)

McCoy, Tammy Michelle

The purpose of this work is to extend the functionality of the Master Sintering Curve (MSC) such that it can be used as a practical tool for predicting sintering schemes that combine both a constant heating rate and an isothermal hold. Rather than just being able to predict a final density for the object of interest, the extension to the MSC will actually be able to model a sintering run from start to finish. Because the Johnson model does not incorporate this capability, the work presented is an extension of what has already been shown in literature to be a valuable resource in many sintering situations. A predicted sintering curve that incorporates a combination of constant heating rate and an isothermal hold is more indicative of what is found in real-life sintering operations. This research offers the possibility of predicting the sintering schedule for a material, thereby having advanced information about the extent of sintering, the time schedule for sintering, and the sintering temperature with a high degree of accuracy and repeatability. The research conducted in this thesis focuses on the development of a working model for predicting the sintering schedules of several stabilized zirconia powders having the compositions YSZ (HSY8), 10Sc1CeSZ, 10Sc1YSZ, and 11ScSZ1A. The compositions of the four powders are first verified using x-ray diffraction (XRD) and the particle size and surface area are verified using a particle size analyzer and BET analysis, respectively. The sintering studies were conducted on powder compacts using a double pushrod dilatometer. Density measurements are obtained both geometrically and using the Archimedes method. Each of the four powders is pressed into ¼" diameter pellets using a manual press with no additives, such as a binder or lubricant. Using a double push-rod dilatometer, shrinkage data for the pellets is obtained over several different heating rates. The shrinkage data is then converted to reflect the change in relative density of the pellets based on the green density and the theoretical density of each of the compositions. The Master Sintering Curve (MSC) model is then utilized to generate data that can be utilized to predict the final density of the respective powder over a range of heating rates. The Elton Master Sintering Curve Extension (EMSCE) is developed to extend the functionality of the MSC tool. The parameters generated from the original MSC are used in tandem with the solution to the closed integral, theta ≡ 1cTo T1Texp -QRT dT, over a set range of temperatures. The EMSCE is used to generate a set of sintering curves having both constant heating rate and isothermal hold portions. The EMSCE extends the usefulness of the MSC by allowing this generation of a complete sintering schedule rather than just being able to predict the final relative density of a given material. The EMSCE is verified by generating a set of curves having both constant heating rate and an isothermal hold for the heat-treatment. The modeled curves are verified experimentally and a comparison of the model and experimental results are given for a selected composition. Porosity within the final product can hinder the product from sintering to full density. It is shown that some of the compositions studied did not sinter to full density because of the presence of large porosity that could not be eliminated in a reasonable amount of time. A statistical analysis of the volume fraction of porosity is completed to show the significance of the presence in the final product. The reason this is relevant to the MSC is that the model does not take into account the presence of porosity and assumes that the samples sinter to full density. When this does not happen, the model actually under-predicts the final density of the material.

BMI percentile curves for Chinese children aged 7-18 years, in comparison with the WHO and the US Centers for Disease Control and Prevention references.

PubMed

Ma, Jun; Wang, Zhiqiang; Song, Yi; Hu, Peijin; Zhang, Bing

2010-12-01

To establish BMI percentile curves that describe the contemporary BMI distribution among Chinese children, and to compare their BMI percentile curves with those in two recently developed international references: the WHO and the US Centers for Disease Control and Prevention (US CDC) growth references. A cross-sectional national survey. Thirty provinces, municipalities and autonomous regions in China. Nationally representative sample of 232 140 school students aged 7-18 years. BMI percentile curves were established using the LMS method, and were compared with the percentiles of the WHO and the US CDC references. BMI distributions and growth patterns in Chinese children were dramatically different from those in the two international reference populations. Compared with the international reference populations, younger Chinese boys (7-12 years of age) had higher values of the percentiles above the median and lower values of the percentiles below the median, suggesting that they had larger proportions of extreme BMI values in both directions. Chinese girls and older Chinese boys (15-18 years of age) had substantially lower BMI percentiles than their counterparts in the reference populations, particularly those high percentiles among older age groups. The present study described the unique patterns of BMI curves at the national level, and these curves are useful as a reference for comparing different regions and for monitoring changes over time in Chinese children. Higher proportions of children with extreme values in both directions indicate that China is currently facing both an increasing level of obesity and a high level of undernutrition, simultaneously.

Low-cost replicable plastic HUD combiner element

NASA Astrophysics Data System (ADS)

Kress, Bernard; Raulot, Victorien; St. Hilaire, Pierre; Meyrueis, Patrick

2009-05-01

We present a novel technique to fabricate low cost mass replicable plastic HUDs for the transportation industry. HUD are implemented in numerous sectors today (in avionics, automobile, military, machinery,...). Typical implementations include an optical combiner which produces the desired virtual image while leaving the field mostly unaffected by the optics. Such combiners optics are usually implemented as cumbersome catadioptric devices in automobile, dichroic coated curved plates, or expensive volume holograms in commercial and military aviation. We propose a novel way to design, model and fabricate combiner masters which can be replicated in mass by UV casting in plastic. We review the various design techniques required for such elements and the novel mastering technology.

Sandstone and shale compaction curves derived from sonic and gamma ray logs in offshore wells, North Slope, Alaska; parameters for basin modeling

USGS Publications Warehouse

Rowan, Elisabeth L.; Hayba, Daniel O.; Nelson, Philip H.; Burns, W. Matthew; Houseknecht, David W.

2003-01-01

Representative compaction curves for the principle lithologies are essential input for reliable models of basin history. Compaction curves influence estimates of maximum burial and erosion. Different compaction curves may produce significantly different thermal histories. Default compaction curves provided by basin modeling packages may or may not be a good proxy for the compaction properties in a given area. Compaction curves in the published literature span a wide range, even within one lithology, e.g., sandstone (see Panel 3). An abundance of geophysical well data for the North Slope, from both government and private sources, provides us with an unusually good opportunity to develop compaction curves for the Cretaceous-Tertiary Brookian sandstones, siltstones, and shales. We examined the sonic and gamma ray logs from 19 offshore wells (see map), where significant erosion is least likely to have occurred. Our data are primarily from the Cretaceous-Tertiary Brookian sequence and are less complete for older sequences. For each well, the fraction of shale (Vsh) at a given depth was estimated from the gamma ray log, and porosity was computed from sonic travel time. By compositing porosities for the near-pure sand (Vsh99%)from many individual wells we obtained data over sufficient depth intervals to define sandstone and shale 'master' compaction curves. A siltstone curve was defined using the sonic-derived porosities for Vsh values of 50%. These compaction curves generally match most of the sonic porosities with an error of 5% or less. Onshore, the curves are used to estimate the depth of maximum burial at the end of Brookian sedimentation. The depth of sonic-derived porosity profiles is adjusted to give the best match with the 'master' compaction curves. The amount of the depth adjustment is the erosion estimate. Using our compaction curves, erosion estimates on the North Slope range from zero in much of the offshore, to as much as 1500 ft along the coast, and to more than 10,000 ft in the foothills (Panel 3). Compaction curves provide an alternative to vitrinite reflectance for estimating erosion. Vitrinite reflectance data are often very sparse in contrast to well log data and are subject to inconsistencies when measurements are made by different labs. The phenomenon of 'recycling' can also make the reflectance values of dispersed vitrinite problematic for quantifying erosion. Recycling is suspected in dispersed vitrinite in North Slope rocks, particularly in the younger, Cretaceous-Tertiary section. The compaction curves defined here are being integrated into our burial history and thermal models to determine the timing of source rock maturation. An example on Panel 3 shows the results of calculating the maturity of the Shublik Fm. at the Tulaga well using two different sets of shale and siltstone compaction curves. Finally, accurate compaction curves improve a model's ability to realistically simulate the pressure regime during burial, including overpressures.

System maintenance manual for master modeling of aerodynamic surfaces by three-dimensional explicit representation

NASA Technical Reports Server (NTRS)

Gibson, A. F.

1983-01-01

A system of computer programs has been developed to model general three-dimensional surfaces. Surfaces are modeled as sets of parametric bicubic patches. There are also capabilities to transform coordinate to compute mesh/surface intersection normals, and to format input data for a transonic potential flow analysis. A graphical display of surface models and intersection normals is available. There are additional capabilities to regulate point spacing on input curves and to compute surface intersection curves. Internal details of the implementation of this system are explained, and maintenance procedures are specified.

Clarity™ digital PCR system: a novel platform for absolute quantification of nucleic acids.

PubMed

Low, Huiyu; Chan, Shun-Jie; Soo, Guo-Hao; Ling, Belinda; Tan, Eng-Lee

2017-03-01

In recent years, digital polymerase chain reaction (dPCR) has gained recognition in biomedical research as it provides a platform for precise and accurate quantification of nucleic acids without the need for a standard curve. However, this technology has not yet been widely adopted as compared to real-time quantitative PCR due to its more cumbersome workflow arising from the need to sub-divide a PCR sample into a large number of smaller partitions prior to thermal cycling to achieve zero or at least one copy of the target RNA/DNA per partition. A recently launched platform, the Clarity™ system from JN Medsys, simplifies dPCR workflow through the use of a novel chip-in-a-tube technology for sample partitioning. In this study, the performance of Clarity™ was evaluated through quantification of the single-copy human RNase P gene. The system demonstrated high precision and accuracy and also excellent linearity across a range of over 4 orders of magnitude for the absolute quantification of the target gene. Moreover, consistent DNA copy measurements were also attained using a panel of different probe- and dye-based master mixes, demonstrating the system's compatibility with commercial master mixes. The Clarity™ was then compared to the QX100™ droplet dPCR system from Bio-Rad using a set of DNA reference materials, and the copy number concentrations derived from both systems were found to be closely associated. Collectively, the results showed that Clarity™ is a reliable, robust and flexible platform for next-generation genetic analysis.

Shaping ability and safety of five different rotary nickel-titanium instruments compared with stainless steel hand instrumentation in simulated curved root canals.

PubMed

Schirrmeister, Jörg F; Strohl, Christian; Altenburger, Markus J; Wrbas, Karl-Thomas; Hellwig, Elmar

2006-06-01

To compare the shaping ability and safety of engine-driven FlexMaster, GT Rotary, ProFile, ProTaper, and RaCe rotary instrumentation and Hedström hand instrumentation in simulated root canals. One hundred fifty simulated colored root canals with a curvature of 20 degrees and a radius of 10 mm were randomly distributed among 6 groups of 25 specimens each. After preparation to apical size 30 the area of remaining color on the canal wall indicating unprepared areas was measured in mm2 using image analyzer software. Specimens treated with RaCe left least areas of remaining color compared to all other groups (P < .001), followed by ProTaper. Preparation with ProFile left behind the highest amount of unprepared areas. The ProFile group revealed significantly more remaining color than ProTaper, GT Rotary, and FlexMaster (P < .05). Four FlexMaster files separated. RaCe rotary files were safe and more effective compared to the other instruments.

[On the notes of the Xinkan Huangdimingtangjiujing (see text for symbol) in the possession of the National Diet Library].

PubMed

Amano, Yosuke

2014-12-01

This paper analyzes the notes of Xinkan huangdimingtangjiujing which are in the possession of the National Diet Library, particularly referring to those notes which include "master said", or "master's theory". Some of those are found in the answers from Manase Dosan (see text for symbol) to Hata Soha (see text for symbol) collected in the Kotei meido kyukyo hushin shosho (see text for symbol) which is the record of the question and answer letters between Manase Dosan and Hata Soha. This research indicates that this volume has a close relation to the acupuncture research of Dosan's or Soha's school. And it indicates that the "master" in the Notes of Xinkan huangdimingtangjiujing refers to Dosan. Acupuncture research has been flourishing since the Edo era and has compiled a lot of volumes on acupuncture. This volume contains some pioneering pieces of this research done in the Azuchi Momoyama era by Dosan and Soha, and is a precious material, showing that some of the state of affairs of the research done in that age still remains today.

Association of cholesterol, LDL, HDL, cholesterol/ HDL and triglyceride with all-cause mortality in life insurance applicants.

PubMed

Fulks, Michael; Stout, Robert L; Dolan, Vera F

2009-01-01

Determine the relationship between various lipid tests and all-cause mortality in life insurance applicants stratified by age and sex. By use of the Social Security Death Master File, mortality was determined in 1,488,572 life insurance applicants from whom blood samples were submitted to Clinical Reference Laboratory. There were 41,020 deaths observed in this healthy adult population during a median follow-up of 12 years (range 10 to 14 years). Results were stratified by 4 age-sex subpopulations: females, ages 20 to 59 or 60+; and males, ages 20 to 59 or 60+. Those with serum albumin < 3.6 mg/dL or fructosamine > or = 2.1 mmol/L were excluded. The middle 50% of lipid values specific to each of these 4 age-sex subpopulations was used as the reference band. The mortality rates in bands representing other percentiles of lipid values were compared with the mortality rate in the reference band within each age-sex subpopulation. In contrast to some published findings from general populations, lipid test results are only moderately predictive of all-cause mortality risk in a life insurance applicant population and that risk is dependent on age and sex. At ages below 60, HDL values are associated with a "J" shaped mortality curve and at ages 60+, total cholesterol is associated with a "U" shaped curve. The total cholesterol/HDL ratio may serve as a useful single measure to predict mortality risk, but only if stratified by age and sex, and only if high HDL values at younger ages and lower total cholesterol values at ages 60+ are recognized as being associated with increased risk as well. Using LDL or non-HDL cholesterol instead of total cholesterol does not improve mortality risk discrimination; neither does using total cholesterol or triglyceride values in addition to the total cholesterol/HDL ratio. The total cholesterol/HDL ratio is the best single measure of all-cause mortality risk among the various lipid tests but is useful only if viewed on an age- and sex-specific basis and is only a modest risk predictor.

Coeur d'Alene Tribal Production Facility, Volume I of III, 2002-2003 Progress Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anders, Paul

2003-01-01

In fulfillment of the NWPPC's 3-Step Process for the implementation of new hatcheries in the Columbia Basin, this Step 1 submission package to the Council includes four items: (1) Cover letter from the Coeur d'Alene Tribe, Interdisciplinary Team Chair, and the USFWS; (2) References to key information (Attachments 1-4); (3) The updated Master Plan for the Tribe's native cutthroat restoration project; and (4) Appendices. In support of the Master Plan submitted by the Coeur d'Alene Tribe the reference chart (Item 2) was developed to allow reviewers to quickly access information necessary for accurate peer review. The Northwest Power Planning Councilmore » identified pertinent issues to be addressed in the master planning process for new artificial production facilities. References to this key information are provided in three attachments: (1) NWPPC Program language regarding the Master Planning Process, (2) Questions Identified in the September 1997 Council Policy, and (3) Program language identified by the Council's Independent Scientific Review Panel (ISRP). To meet the need for off-site mitigation for fish losses on the mainstem Columbia River, in a manner consistent with the objectives of the Council's Program, the Coeur d'Alene Tribe is proposing that the BPA fund the design, construction, operation, and maintenance of a trout production facility located adjacent to Coeur d'Alene Lake on the Coeur d'Alene Indian Reservation. The updated Master Plan (Item 3) represents the needs associated with the re-evaluation of the Coeur d'Alene Tribe's Trout Production Facility (No.199004402). This plan addresses issues and concerns expressed by the NWPPC as part of the issue summary for the Mountain Columbia provincial review, and the 3-step hatchery review process. Finally, item 4 (Appendices) documents the 3-Step process correspondence to date between the Coeur d'Alene Tribe and additional relevant entities. Item 4 provides a chronological account of previous ISRP reviews, official Coeur d'Alene fisheries program responses to a series of ISRP reviews, master planning documentation, and annual reports dating back to 1990. Collectively, the materials provided by the Coeur d'Alene Tribe in this Step-1 submission package comprehensively assesses key research, habitat improvement activities, and hatchery production issues to best protect and enhance native cutthroat trout populations and the historically and culturally important tribal fisheries they support.« less

Master-slave mixed arrays for data-flow computations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, T.L.; Fisher, P.D.

1983-01-01

Control cells (masters) and computation cells (slaves) are mixed in regular geometric patterns to form reconfigurable arrays known as master-slave mixed arrays (MSMAS). Interconnections of the corners and edges of the hexagonal control cells and the edges of the hexagonal computation cells are used to construct synchronous and asynchronous communication networks, which support local computation and local communication. Data-driven computations result in self-directed ring pipelines within the MSMA, and composite data-flow computations are executed in a pipelined fashion. By viewing an MSMA as a computing network of tightly-linked ring pipelines, data-flow programs can be uniformly distributed over these pipelines formore » efficient resource utilisation. 9 references.« less

Computer Literacy Project 1983.

ERIC Educational Resources Information Center

El Dorado County Office of Education, Placerville, CA.

A K-12 computer literacy course of study is presented. Four basic parts are included: (1) a reference index which organizes 37 computer literacy topics into seven major categories; (2) a master index which presents goals for each topic by grade level and lists a reference number for each goal; (3) a scope and sequence organized by grade level…

Effects of Aging-Time Reference on the Long Term Behavior of the IM7/K3B Composite

NASA Technical Reports Server (NTRS)

Veazie, David R.; Gates, Thomas S.

1998-01-01

An analytical study was undertaken to investigate the effects of the time-based shift reference on the long term behavior of the graphite reinforced thermoplastic polyimide composite IM7/K3B at elevated temperature. Creep compliance and the effects of physical aging on the time dependent response was measured for uniaxial loading at several isothermal conditions below the glass transition temperature (T(sub g). Two matrix dominated loading modes, shear and transverse, were investigated in tension and compression. The momentary sequenced creep/aging curves were collapsed through a horizontal (time) shift using the shortest, middle and longest aging time curve as the reference curve. Linear viscoelasticity was used to characterize the creep/recovery behavior and superposition techniques were used to establish the physical aging related material constants. The use of effective time expressions in a laminated plate model allowed for the prediction of long term creep compliance. The effect of using different reference curves with time/aging-time superposition was most sensitive to the physical aging shift rate at lower test temperatures. Depending on the loading mode, the reference curve used can result in a more accurate long term prediction, especially at lower test temperatures.

Non-Gaussian limit fluctuations in active swimmer suspensions

NASA Astrophysics Data System (ADS)

Kurihara, Takashi; Aridome, Msato; Ayade, Heev; Zaid, Irwin; Mizuno, Daisuke

2017-03-01

We investigate the hydrodynamic fluctuations in suspensions of swimming microorganisms (Chlamydomonas) by observing the probe particles dispersed in the media. Short-term fluctuations of probe particles were superdiffusive and displayed heavily tailed non-Gaussian distributions. The analytical theory that explains the observed distribution was derived by summing the power-law-decaying hydrodynamic interactions from spatially distributed field sources (here, swimming microorganisms). The summing procedure, which we refer to as the physical limit operation, is applicable to a variety of physical fluctuations to which the classical central limiting theory does not apply. Extending the analytical formula to compare to experiments in active swimmer suspensions, we show that the non-Gaussian shape of the observed distribution obeys the analytic theory concomitantly with independently determined parameters such as the strength of force generations and the concentration of Chlamydomonas. Time evolution of the distributions collapsed to a single master curve, except for their extreme tails, for which our theory presents a qualitative explanation. Investigations thereof and the complete agreement with theoretical predictions revealed broad applicability of the formula to dispersions of active sources of fluctuations.

Cooperative Activated Transport of Dilute Penetrants in Viscous Molecular and Polymer Liquids

NASA Astrophysics Data System (ADS)

Schweizer, Kenneth; Zhang, Rui

We generalize the force-level Elastically Collective Nonlinear Langevin Equation theory of activated relaxation in one-component supercooled liquids to treat the hopping transport of a dilute penetrant in a dense hard sphere fluid. The new idea is to explicitly account for the coupling between penetrant displacement and a local matrix cage re-arrangement which facilitates its hopping. A temporal casuality condition is employed to self-consistently determine a dimensionless degree of matrix distortion relative to the penetrant jump distance using the dynamic free energy concept. Penetrant diffusion becomes increasingly coupled to the correlated matrix displacements for larger penetrant to matrix particle size ratio (R) and/or attraction strength (physical bonds), but depends weakly on matrix packing fraction. In the absence of attractions, a nearly exponential dependence of penetrant diffusivity on R is predicted in the intermediate range of 0.2

Temperature dependence of ion transport: the compensated Arrhenius equation.

PubMed

Petrowsky, Matt; Frech, Roger

2009-04-30

The temperature-dependent conductivity originating in a thermally activated process is often described by a simple Arrhenius expression. However, this expression provides a poor description of the data for organic liquid electrolytes and amorphous polymer electrolytes. Here, we write the temperature dependence of the conductivity as an Arrhenius expression and show that the experimentally observed non-Arrhenius behavior is due to the temperature dependence of the dielectric constant contained in the exponential prefactor. Scaling the experimentally measured conductivities to conductivities at a chosen reference temperature leads to a "compensated" Arrhenius equation that provides an excellent description of temperature-dependent conductivities. A plot of the prefactors as a function of the solvent dielectric constant results in a single master curve for each family of solvents. These data suggest that ion transport in these and related systems is governed by a single activated process differing only in the activation energy for each family of solvents. Connection is made to the shift factor used to describe electrical and mechanical relaxation in a wide range of phenomena, suggesting that this scaling procedure might have broad applications.

Phase-dependent Photometric and Spectroscopic Characterization of the MASTER-Net Optical Transient J212444.87+321738.3: An Oxygen-rich Mira

NASA Astrophysics Data System (ADS)

Ghosh, Supriyo; Mondal, Soumen; Das, Ramkrishna; Banerjee, D. P. K.; Ashok, N. M.; Hambsch, Franz-Josef; Dutta, Somnath

2018-05-01

We describe the time-dependent properties of a new spectroscopically confirmed Mira variable, which was discovered in 2013 as MASTER-Net Optical Transient J212444.87+321738.3 toward the Cygnus constellation. We have performed long-term optical/near-infrared (NIR) photometric and spectroscopic observations to characterize the object. From the optical/NIR light curves, we estimate a variability period of 465 ± 30 days. The wavelength-dependent amplitudes of the observed light curves range from ΔI ∼ 4 mag to ΔK ∼ 1.5 mag. The (J ‑ K) color index varies from 1.78 to 2.62 mag over phases. Interestingly, a phase lag of ∼60 days between optical and NIR light curves is also seen, as in other Miras. Our optical/NIR spectra show molecular features of TiO, VO, CO, and strong water bands that are a typical signature of oxygen-rich Mira. We rule out S- or C-type as ZrO bands at 1.03 and 1.06 μm and C2 band at 1.77 μm are absent. We estimate the effective temperature of the object from the Spectral Energy Distribution, and distance and luminosity from standard Period–Luminosity relations. The optical/NIR spectra display time-dependent atomic and molecular features (e.g., TiO, Na I, Ca I, H2O, CO), as commonly observed in Miras. Such spectroscopic observations are useful for studying pulsation variability in Miras.

Long-Term Viscoelastic Response of E-glass/Bismaleimide Composite in Seawater Environment

NASA Astrophysics Data System (ADS)

Yian, Zhao; Zhiying, Wang; Keey, Seah Leong; Boay, Chai Gin

2015-12-01

The effect of seawater absorption on the long-term viscoelastic response of E-glass/BMI composite is presented in this paper. The diffusion of seawater into the composite shows a two-stage behavior, dominated by Fickian diffusion initially and followed by polymeric relaxation. The Glass transition temperature (Tg) of the composite with seawater absorption is considerably lowered due to the plasticization effect. However the effect of water absorption at 50 °C is found to be reversible after drying process. The time-temperature superposition (TTS) was performed based on the results of Dynamic Mechanical Analysis to construct the master curve of storage modulus. The shift factors exhibit Arrhenius behavior when temperature is well below Tg and Vogel-Fulcher-Tammann (VFT) like behavior when temperature gets close to glass transition region. As a result, a semi-empirical formulation is proposed to account for the seawater absorption effect in predicting long-term viscoelastic response of BMI composites based on temperature dependent storage modulus and TTS. The predicted master curves show that the degradation of storage modulus accelerates with both seawater exposure and increasing temperature. The proposed formulation can be applied to predict the long-term durability of any thermorheologically simple composite materials in seawater environment.

Thermodynamic scaling in ionically conducting glasses and melts

NASA Astrophysics Data System (ADS)

Habasaki, Junko

2013-02-01

Molecular dynamics simulations have been performed to learn temperature, composition, pressure dependencies of the diffusivity and structures in the system having ion channels and network formers. Validity of the thermodynamic scaling in the lithium silicate glasses and melts is shown, where the scaling concept is extended with an aid of a percolation aspect of the ion channels. All diffusion coefficients of ions of different compositions, temperatures, pressures are successfully represented by a single master curve as a function of system volumes, temperatures and volume fraction of M2O part. It enables us to predict the diffusivity in different conditions. Furthermore, it suggests an applicability of scaling concept for the sub-structures in more complex systems. Nearby points on the master curve have the comparable MSD as well as self-part of the van Hove functions. Similarity is observed from an early term region. This observation is consistent to our previous claims [K. L. Ngai, J. Habasaki, D. Prevosto, S. Capaccioli, Marian Paluch, J. Chem. Phys. 137, 034511 (2012)] that the thermodynamic scaling of α-Relaxation time stems from the Johari-Goldstein β-relaxation or the primitive relaxation of the coupling model.

User's manual for master: Modeling of aerodynamic surfaces by 3-dimensional explicit representation. [input to three dimensional computational fluid dynamics

NASA Technical Reports Server (NTRS)

Gibson, S. G.

1983-01-01

A system of computer programs was developed to model general three dimensional surfaces. Surfaces are modeled as sets of parametric bicubic patches. There are also capabilities to transform coordinates, to compute mesh/surface intersection normals, and to format input data for a transonic potential flow analysis. A graphical display of surface models and intersection normals is available. There are additional capabilities to regulate point spacing on input curves and to compute surface/surface intersection curves. Input and output data formats are described; detailed suggestions are given for user input. Instructions for execution are given, and examples are shown.

Reference curves of birth weight, length, and head circumference for gestational ages in Yogyakarta, Indonesia.

PubMed

Haksari, Ekawaty L; Lafeber, Harrie N; Hakimi, Mohammad; Pawirohartono, Endy P; Nyström, Lennarth

2016-11-21

The birth weight reference curve to estimate the newborns at risk in need of assessment and monitoring has been established. The previous reference curves from Indonesia, approximately 8 years ago, were based on the data collected from teaching hospitals only with limited gestational ages. The aims of the study were to update the reference curves for birth weight, supine length and head circumference for Indonesia, and to compare birth weight curves of boys and girls, first child and later children, and the ones in the previous studies. Data were extracted from the Maternal-Perinatal database between 1998-2007. Only live singletons with recorded gestational ages of 26 to 42 weeks and the exact time of admission to the neonatal facilities delivered or referred within 24 h of age to Sardjito Hospital, five district hospitals and five health centers in Yogyakarta Special Territory were included. Newborns with severely ill conditions, congenital anomaly and chromosomal abnormality were excluded. Smoothening of the curves was accomplished using a third-order polynomial equation. Our study included 54,599 singleton live births. Growth curves were constructed for boys (53.3%) and girls (46.7%) for birth weight, supine length, and head circumference. At term, mean birth weight for each gestational age of boys was significantly higher than that of girls. While mean birth weight for each gestational age of first-born-children, on the other hand was significantly lower than that of later-born-children. The mean birth weight was lower than that of Lubchenco's study. Compared with the previous Indonesian study by Alisyahbana, no differences were observed for the aterm infants, but lower mean birth weight was observed in preterm infants. Updated neonatal reference curves for birth weight, supine length and head circumference are important to classify high risk newborns in specific area and to identify newborns requiring attention.

Nocturnal oxygen saturation profiles of healthy term infants

PubMed Central

Terrill, Philip Ian; Dakin, Carolyn; Hughes, Ian; Yuill, Maggie; Parsley, Chloe

2015-01-01

Objective Pulse oximetry is used extensively in hospital and home settings to measure arterial oxygen saturation (SpO2). Interpretation of the trend and range of SpO2 values observed in infants is currently limited by a lack of reference ranges using current devices, and may be augmented by development of cumulative frequency (CF) reference-curves. This study aims to provide reference oxygen saturation values from a prospective longitudinal cohort of healthy infants. Design Prospective longitudinal cohort study. Setting Sleep-laboratory. Patients 34 healthy term infants were enrolled, and studied at 2 weeks, 3, 6, 12 and 24 months of age (N=30, 25, 27, 26, 20, respectively). Interventions Full overnight polysomnography, including 2 s averaging pulse oximetry (Masimo Radical). Main outcome measurements Summary SpO2 statistics (mean, median, 5th and 10th percentiles) and SpO2 CF plots were calculated for each recording. CF reference-curves were then generated for each study age. Analyses were repeated with sleep-state stratifications and inclusion of manual artefact removal. Results Median nocturnal SpO2 values ranged between 98% and 99% over the first 2 years of life and the CF reference-curves shift right by 1% between 2 weeks and 3 months. CF reference-curves did not change with manual artefact removal during sleep and did not vary between rapid eye movement (REM) and non-REM sleep. Manual artefact removal did significantly change summary statistics and CF reference-curves during wake. Conclusions SpO2 CF curves provide an intuitive visual tool for evaluating whether an individual's nocturnal SpO2 distribution falls within the range of healthy age-matched infants, thereby complementing summary statistics in the interpretation of extended oximetry recordings in infants. PMID:25063836

A bill to designate the facility of the United States Postal Service located at 4000 Leap Road in Hilliard, Ohio, as the "Master Sergeant Shawn T. Hannon, Master Sergeant Jeffrey J. Rieck and Veterans Memorial Post Office Building".

THOMAS, 113th Congress

Sen. Portman, Rob [R-OH

2014-11-12

Senate - 11/12/2014 Read twice and referred to the Committee on Homeland Security and Governmental Affairs. (All Actions) Notes: For further action, see H.R.4189, which became Public Law 113-219 on 12/16/2014. Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

STEM Master Teacher Corps Act

THOMAS, 112th Congress

Rep. Bishop, Timothy H. [D-NY-1

2011-07-20

House - 09/08/2011 Referred to the Subcommittee on Early Childhood, Elementary, and Secondary Education. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Is It Time to Change Our Reference Curve for Femur Length? Using the Z-Score to Select the Best Chart in a Chinese Population

PubMed Central

Yang, Huixia; Wei, Yumei; Su, Rina; Wang, Chen; Meng, Wenying; Wang, Yongqing; Shang, Lixin; Cai, Zhenyu; Ji, Liping; Wang, Yunfeng; Sun, Ying; Liu, Jiaxiu; Wei, Li; Sun, Yufeng; Zhang, Xueying; Luo, Tianxia; Chen, Haixia; Yu, Lijun

2016-01-01

Objective To use Z-scores to compare different charts of femur length (FL) applied to our population with the aim of identifying the most appropriate chart. Methods A retrospective study was conducted in Beijing. Fifteen hospitals in Beijing were chosen as clusters using a systemic cluster sampling method, in which 15,194 pregnant women delivered from June 20th to November 30th, 2013. The measurements of FL in the second and third trimester were recorded, as well as the last measurement obtained before delivery. Based on the inclusion and exclusion criteria, we identified FL measurements from 19996 ultrasounds from 7194 patients between 11 and 42 weeks gestation. The FL data were then transformed into Z-scores that were calculated using three series of reference equations obtained from three reports: Leung TN, Pang MW et al (2008); Chitty LS, Altman DG et al (1994); and Papageorghiou AT et al (2014). Each Z-score distribution was presented as the mean and standard deviation (SD). Skewness and kurtosis and were compared with the standard normal distribution using the Kolmogorov-Smirnov test. The histogram of their distributions was superimposed on the non-skewed standard normal curve (mean = 0, SD = 1) to provide a direct visual impression. Finally, the sensitivity and specificity of each reference chart for identifying fetuses <5th or >95th percentile (based on the observed distribution of Z-scores) were calculated. The Youden index was also listed. A scatter diagram with the 5th, 50th, and 95th percentile curves calculated from and superimposed on each reference chart was presented to provide a visual impression. Results The three Z-score distribution curves appeared to be normal, but none of them matched the expected standard normal distribution. In our study, the Papageorghiou reference curve provided the best results, with a sensitivity of 100% for identifying fetuses with measurements < 5th and > 95th percentile, and specificities of 99.9% and 81.5%, respectively. Conclusions It is important to choose an appropriate reference curve when defining what is normal. The Papageorghiou reference curve for FL seems to be the best fit for our population. Perhaps it is time to change our reference curve for femur length. PMID:27458922

Skinfold reference curves and their use in predicting metabolic syndrome risk in children.

PubMed

Andaki, Alynne C R; Quadros, Teresa M B de; Gordia, Alex P; Mota, Jorge; Tinôco, Adelson L A; Mendes, Edmar L

To draw skinfold (SF) reference curves (subscapular, suprailiac, biceps, triceps) and to determine SF cutoff points for predicting the risk of metabolic syndrome (MetS) in children aged 6-10 years old. This was a cross-sectional study with a random sample of 1480 children aged 6-10 years old, 52.2% females, from public and private schools located in the urban and rural areas of the municipality of Uberaba (MG). Anthropometry, blood pressure, and fasting blood samples were taken at school, following specific protocols. The LMS method was used to draw the reference curves and ROC curve analysis to determine the accuracy and cutoff points for the evaluated skinfolds. The four SF evaluated (subscapular, suprailiac, biceps, and triceps) and their sum (∑4SF) were accurate in predicting MetS for both girls and boys. Additionally, cutoffs have been proposed and percentile curves (p5, p10, p25, p50, p75, p90, and p95) were outlined for the four SF and ∑4SF, for both genders. SF measurements were accurate in predicting metabolic syndrome in children aged 6-10 years old. Age- and gender-specific smoothed percentiles curves of SF provide a reference for the detection of risk for MetS in children. Copyright © 2017. Published by Elsevier Editora Ltda.

ASSESSMENT OF NUTRITIONAL STATUS OF CHILDREN AND ADOLESCENTS WITH SPASTIC QUADRIPLEGIC CEREBRAL PALSY.

PubMed

Caselli, Thaisa Barboza; Lomazi, Elizete Aparecida; Montenegro, Maria Augusta Santos; Bellomo-Brandão, Maria Angela

2017-01-01

Due to several factors, such as gastrointestinal's diseases and difficulty in feeding, children with Spastic Quadriplegic Cerebral Palsy tend to present nutritional deficits. To assess the nutritional status of pediatric patients with Spastic Quadriplegic Cerebral Palsy according to reference curves for this population and with the measures of folds and circumferences, obtained by the upper arm circumference and triceps skin fold. The data were obtained from: knee-height, estimated height, weight, upper arm circumference, and triceps skin fold. Values of folds and circumferences were compared with Frisancho, and specific curves for these patients were used as reference. The relationship between the values in the growth curve for healthy children, Z-Score, and comparison with the reference curve were verified by Fisher's exact test. We adopted the significance level of 5%. We evaluated 54 patients. The mean age was 10.2 years, and 34 were male, 25 fed by gastrostomy and 29, orally. The frequency of low weight by the reference curve was 22.22%. More than half of the patients presented the parameters indicating lean mass below the 5th percentile. The height of all patients was classified as adequate for the age by the reference curve. Low weight was found in 22% of patients, and there is a greater tendency to present reduced muscle mass and increased fat mass, showing the need for evaluation and appropriate interventions for patients with Spastic Quadriplegic Cerebral Palsy.

Creep-rupture of polymer-matrix composites. [graphite-epoxy laminates

NASA Technical Reports Server (NTRS)

Brinson, H. F.; Griffith, W. I.; Morris, D. H.

1980-01-01

An accelerated characterization method for resin matrix composites is reviewed. Methods for determining modulus and strength master curves are given. Creep rupture analytical models are discussed as applied to polymers and polymer matrix composites. Comparisons between creep rupture experiments and analytical models are presented. The time dependent creep rupture process in graphite epoxy laminates is examined as a function of temperature and stress level.

Analytical drafting curves provide exact equations for plotted data

NASA Technical Reports Server (NTRS)

Stewart, R. B.

1967-01-01

Analytical drafting curves provide explicit mathematical expressions for any numerical data that appears in the form of graphical plots. The curves each have a reference coordinate axis system indicated on the curve as well as the mathematical equation from which the curve was generated.

Features of a Post-Identitarian Pedagogy (with Reference to Postgraduate Student Writing and the Continuing Professional Development of Teachers)

ERIC Educational Resources Information Center

Done, Elizabeth; Knowler, Helen

2013-01-01

This article responds to Aitchson's observation that development of new pedagogic practices for teaching writing is inhibited by lack of research into how such pedagogies work in practice. The article refers to research into the introduction of a module, "Writing as Professional Development", on a part-time master's-level programme for…

STEM Master Teacher Corps Act of 2013

THOMAS, 113th Congress

Sen. Franken, Al [D-MN

2013-02-14

Senate - 02/14/2013 Read twice and referred to the Committee on Health, Education, Labor, and Pensions. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Managed Development Environment Successes for MSFC's VIPA Team

NASA Technical Reports Server (NTRS)

Finckenor, Jeff; Corder, Gary; Owens, James; Meehan, Jim; Tidwell, Paul H.

2005-01-01

This paper outlines the best practices of the Vehicle Design Team for VIPA. The functions of the VIPA Vehicle Design (VVD) discipline team are to maintain the controlled reference geometry and provide linked, simplified geometry for each of the other discipline analyses. The core of the VVD work, and the approach for VVD s first task of controlling the reference geometry, involves systems engineering, top-down, layout-based CAD modeling within a Product Data Manager (PDM) development environment. The top- down approach allows for simple control of very large, integrated assemblies and greatly enhances the ability to generate trade configurations and reuse data. The second VVD task, model simplification for analysis, is handled within the managed environment through application of the master model concept. In this approach, there is a single controlling, or master, product definition dataset. Connected to this master model are reference datasets with live geometric and expression links. The referenced models can be for drawings, manufacturing, visualization, embedded analysis, or analysis simplification. A discussion of web based interaction, including visualization, between the design and other disciplines is included. Demonstrated examples are cited, including the Space Launch Initiative development cycle, the Saturn V systems integration and verification cycle, an Orbital Space Plane study, and NASA Exploration Office studies of Shuttle derived and clean sheet launch vehicles. The VIPA Team has brought an immense amount of detailed data to bear on program issues. A central piece of that success has been the Managed Development Environment and the VVD Team approach to modeling.

[Analysis of master degree thesis of otolaryngology head and neck surgery in Xinjiang].

PubMed

Ayiheng, Qukuerhan; Niliapaer, Alimu; Yalikun, Yasheng

2010-12-01

To understand the basic situation and development of knowledge structure and ability of master degree of Otolaryngology Head and Neck Surgery in Xinjiang region in order to provide reference to further improve the quality of postgraduate students. Fourty-six papers of Otolaryngology master degree thesis were reviewed at randomly in terms of types, subject selection ranges as well as statistical methods during 1998-2009 in Xinjiang region in order to analyze and explore its advantages and characteristics and suggest a solution for its disadvantages. In 46 degree thesis, nine of them are scientific dissertations accounting for 19.57%, 37 are clinical professional degree thesis, accounting for 80.43%. Five are Experimental research papers, 30 are clinical research papers, 10 are clinical and experimental research papers, 1 of them is experimental epidemiology research paper; in this study, the kinds of diseases including every subject of ENT, various statistical methods are involved; references are 37.46 in average, 19.55 of them are foreign literatures references in nearly 5 years are 13.57; four ethnic groups are exist in postgraduate students with high teaching professional level of tutors. The clinical research should be focused in order to further research on ENT common diseases, the application of advanced research methods, the full application of the latest literature, tutors with high-level, training of students of various nationalities, basic research needs to be innovative and should be focus the subject characteristics, to avoid excessive duplication of research.

Reference curves for the Australian/Canadian Hand Osteoarthritis Index in the middle-aged Dutch population.

PubMed

Kroon, Féline P B; Ramiro, Sofia; Royston, Patrick; Le Cessie, Saskia; Rosendaal, Frits R; Kloppenburg, Margreet

2017-05-01

The aim was to establish reference curves of the Australian/Canadian Hand Osteoarthritis Index (AUSCAN), a widely used questionnaire assessing hand complaints. Analyses were performed in a population-based sample, The Netherlands Epidemiology of Obesity study (n = 6671, aged 45-65 years). Factors associated with AUSCAN scores were analysed with ordered logistic regression, because AUSCAN data were zero inflated, dividing AUSCAN into three categories (0 vs 1-5 vs >5). Age- and sex-specific reference curves for the AUSCAN (range 0-60; higher is worse) were developed using quantile regression in conjunction with fractional polynomials. Observed scores in relevant subgroups were compared with the reference curves. The median age was 56 [interquartile range (IQR): 50-61] years; 56% were women and 12% had hand OA according to ACR criteria. AUSCAN scores were low (median 1; IQR: 0-4). Reference curves where higher for women, and increased moderately with age: 95% percentiles for AUSCAN in men and women were, respectively, 5.0 and 12.3 points for a 45-year-old, and 15.2 and 33.6 points for a 65-year-old individual. Additional associated factors included hand OA, inflammatory rheumatic diseases, FM, socio-economic status and BMI. Median AUSCAN pain subscale scores of women with hand OA lay between the 75th and 90th centiles of the general population. AUSCAN scores in the middle-aged Dutch population were low overall, and higher in women than in men. AUSCAN reference curves could serve as a benchmark in research and clinical practice settings. However, the AUSCAN does not measure hand complaints specific for hand OA. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Creation of a master table for checking indication and contraindication of medicine from a knowledge base linked with a thesaurus.

PubMed

Ji, Shanmei; Matsumura, Yasushi; Kuwata, Shigeki; Nakano, Hirohiko; Chen, Yufeng; Teratani, Tadamasa; Zhang, Qiyan; Mineno, Takahiro; Takeda, Hiroshi

2004-12-01

To develop a system for checking indication and contraindication of medicines in prescription order entry system, a master table consisting of the disease names corresponding to the medicines adopted in a hospital is needed. The creation of this table requires a considerable manpower. We developed a Web-based system for constructing a medicine/disease thesaurus and a knowledge base. By authority management of users, this system enables many specialists to create the thesaurus collaboratively without confusion. It supports the creation of a knowledge base using concept names by referring to the thesaurus, which is automatically converted to the check master table. When a disease name or medicine name was added to the thesaurus, the check table was automatically updated. We constructed a thesaurus and a knowledge base in the field of circulatory system disease. The knowledge base linked with the thesaurus proved to be efficient for making the check master table for indication/contraindication of medicines.

Definitions of components of the master water data index maintained by the National Water Data Exchange

USGS Publications Warehouse

Perry, R.A.; Williams, O.O.

1982-01-01

The Master Water Data Index is a computerized data base developed and maintained by the National Water Data Exchange (NAWDEX). The Index contains information about water-data collection sites. This information includes: the identification of new sites for which water data are available, the locations of these sites, the type of site, the data-collection organization, the types of data available, the major water-data parameters for which data are available, the frequency at which these parameters are measured, the period of time for which data are available, and the medial in which the data are stored. This document, commonly referred to as the MWDI data dictionary, contains a definition and description of each component of the Master Water Data Index data base. (USGS)

Reference Curve for the Mean Uterine Artery Pulsatility Index in Singleton Pregnancies.

PubMed

Weichert, Alexander; Hagen, Andreas; Tchirikov, Michael; Fuchs, Ilka B; Henrich, Wolfgang; Entezami, Michael

2017-05-01

Doppler sonography of the uterine artery (UA) is done to monitor pregnancies, because the detected flow patterns are useful to draw inferences about possible disorders of trophoblast invasion. Increased resistance in the UA is associated with an increased risk of preeclampsia and/or intrauterine growth restriction (IUGR) and perinatal mortality. In the absence of standardized figures, the normal ranges of the various available reference curves sometimes differ quite substantially from one another. The causes for this are differences in the flow patterns of the UA depending on the position of the pulsed Doppler gates as well as branching of the UA. Because of the discrepancies between the different reference curves and the practical problems this poses for guideline recommendations, we thought it would be useful to create our own reference curves for Doppler measurements of the UA obtained from a singleton cohort under standardized conditions. This retrospective cohort study was carried out in the Department of Obstetrics of the Charité - Universitätsmedizin Berlin, the Department for Obstetrics and Prenatal Medicine of the University Hospital Halle (Saale) and the Center for Prenatal Diagnostics and Human Genetics Kurfürstendamm 199. Available datasets from the three study locations were identified and reference curves were generated using the LMS method. Measured values were correlated with age of gestation, and a cubic model and Box-Cox power transformation (L), the median (M) and the coefficient of variation (S) were used to smooth the curves. 103 720 Doppler examinations of the UA carried out in singleton pregnancies from the 11th week of gestation (10 + 1 GW) were analyzed. The mean pulsatility index (Mean PI) showed a continuous decline over the course of pregnancy, dropping to a plateau of around 0.84 between the 23rd and 27th GW, after which it decreased again. Age of gestation, placental position, position of pulsed Doppler gates and branching of the UA can all change the flow pattern. The mean pulsatility index (Mean PI) showed a continuous decrease over time. There were significant differences between our data and alternative reference curves. A system of classifying Doppler studies and a reference curve adapted to the current technology are urgently required to differentiate better between physiological and pathological findings.

Geomagnetic field secular variation in Pacific Ocean: A Bayesian reference curve based on Holocene Hawaiian lava flows

NASA Astrophysics Data System (ADS)

Tema, E.; Herrero-Bervera, E.; Lanos, Ph.

2017-11-01

Hawaii is an ideal place for reconstructing the past variations of the Earth's magnetic field in the Pacific Ocean thanks to the almost continuous volcanic activity during the last 10 000 yrs. We present here an updated compilation of palaeomagnetic data from historic and radiocarbon dated Hawaiian lava flows available for the last ten millennia. A total of 278 directional and 66 intensity reference data have been used for the calculation of the first full geomagnetic field reference secular variation (SV) curves for central Pacific covering the last ten millennia. The obtained SV curves are calculated following recent advances on curve building based on the Bayesian statistics and are well constrained for the last five millennia while for older periods their error envelopes are wide due to the scarce number of reference data. The new Bayesian SV curves show three clear intensity maxima during the last 3000 yrs that are accompanied by sharp directional changes. Such short-term variations of the geomagnetic field could be interpreted as archaeomagnetic jerks and could be an interesting feature of the geomagnetic field variation in the Pacific Ocean that should be further explored by new data.

(abstract) Precision Time and Frequency Transfer Utilizing SONET OC-3

NASA Technical Reports Server (NTRS)

Stein, Sam; Calhoun, Malcom; Kuhnle, Paul; Sydnor, Richard; Gifford, Al

1996-01-01

An innovative method of distributing precise time and reference frequency to users located several kilometers from a frequency standard and master clock has been developed by the Timing Solutions Corporation of Boulder, CO. The Optical Two-Way Time Transfer System (OTWTTS) utilizes a commercial SONET OC-3 facility interface to physically connect a master unit to multiple slave units at remote locations. Optical fiber is a viable alternative to standard copper cable and microwave transmission. This paper discusses measurements of frequency and timing stability over the OTWTTS.

Nocturnal oxygen saturation profiles of healthy term infants.

PubMed

Terrill, Philip Ian; Dakin, Carolyn; Hughes, Ian; Yuill, Maggie; Parsley, Chloe

2015-01-01

Pulse oximetry is used extensively in hospital and home settings to measure arterial oxygen saturation (SpO2). Interpretation of the trend and range of SpO2 values observed in infants is currently limited by a lack of reference ranges using current devices, and may be augmented by development of cumulative frequency (CF) reference-curves. This study aims to provide reference oxygen saturation values from a prospective longitudinal cohort of healthy infants. Prospective longitudinal cohort study. Sleep-laboratory. 34 healthy term infants were enrolled, and studied at 2 weeks, 3, 6, 12 and 24 months of age (N=30, 25, 27, 26, 20, respectively). Full overnight polysomnography, including 2 s averaging pulse oximetry (Masimo Radical). Summary SpO2 statistics (mean, median, 5th and 10th percentiles) and SpO2 CF plots were calculated for each recording. CF reference-curves were then generated for each study age. Analyses were repeated with sleep-state stratifications and inclusion of manual artefact removal. Median nocturnal SpO2 values ranged between 98% and 99% over the first 2 years of life and the CF reference-curves shift right by 1% between 2 weeks and 3 months. CF reference-curves did not change with manual artefact removal during sleep and did not vary between rapid eye movement (REM) and non-REM sleep. Manual artefact removal did significantly change summary statistics and CF reference-curves during wake. SpO2 CF curves provide an intuitive visual tool for evaluating whether an individual's nocturnal SpO2 distribution falls within the range of healthy age-matched infants, thereby complementing summary statistics in the interpretation of extended oximetry recordings in infants. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Computer program documentation user information for the RSO-tape print program (RSOPRNT)

NASA Technical Reports Server (NTRS)

Gibbs, P. M. (Principal Investigator)

1980-01-01

A user's guide for the RSOPRNT, a TRASYS Master Restart Output Tape (RSO) reader is presented. Background information and sample runstreams, as well as, references, input requirements and options, are included.

Interpretation of magnetotelluric resistivity and phase soundings over horizontal layers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patella, D.

1976-02-01

The present paper deals with a new inverse method for quantitatively interpreting magnetotelluric apparent resistivity and phase-lag sounding curves over horizontally stratified earth sections. The recurrent character of the general formula relating the wave impedance of an (n-l)-layered medium to that of an n-layered medium suggests the use of the method of reduction to a lower boundary plane, as originally termed by Koefoed in the case of dc resistivity soundings. The layering parameters are so directly derived by a simple iterative procedure. The method is applicable for any number of layers but only when both apparent resistivity and phase-lag soundingmore » curves are jointly available. Moreover no sophisticated algorithm is required: a simple desk electronic calculator together with a sheet of two-layer apparent resistivity and phase-lag master curves are sufficient to reproduce earth sections which, in the range of equivalence, are all consistent with field data.« less

An automated and objective method for age partitioning of reference intervals based on continuous centile curves.

PubMed

Yang, Qian; Lew, Hwee Yeong; Peh, Raymond Hock Huat; Metz, Michael Patrick; Loh, Tze Ping

2016-10-01

Reference intervals are the most commonly used decision support tool when interpreting quantitative laboratory results. They may require partitioning to better describe subpopulations that display significantly different reference values. Partitioning by age is particularly important for the paediatric population since there are marked physiological changes associated with growth and maturation. However, most partitioning methods are either technically complex or require prior knowledge of the underlying physiology/biological variation of the population. There is growing interest in the use of continuous centile curves, which provides seamless laboratory reference values as a child grows, as an alternative to rigidly described fixed reference intervals. However, the mathematical functions that describe these curves can be complex and may not be easily implemented in laboratory information systems. Hence, the use of fixed reference intervals is expected to continue for a foreseeable time. We developed a method that objectively proposes optimised age partitions and reference intervals for quantitative laboratory data (http://research.sph.nus.edu.sg/pp/ppResult.aspx), based on the sum of gradient that best describes the underlying distribution of the continuous centile curves. It is hoped that this method may improve the selection of age intervals for partitioning, which is receiving increasing attention in paediatric laboratory medicine. Copyright © 2016 Royal College of Pathologists of Australasia. Published by Elsevier B.V. All rights reserved.

Autonomic cardiovascular modulation in masters and young cyclists following high-intensity interval training.

PubMed

Borges, Nattai R; Reaburn, Peter R; Doering, Thomas M; Argus, Christos K; Driller, Matthew W

2017-04-01

This study aimed at examining the autonomic cardiovascular modulation in well-trained masters and young cyclists following high-intensity interval training (HIT). Nine masters (age 55.6 ± 5.0 years) and eight young cyclists (age 25.9 ± 3.0 years) completed a HIT protocol of 6 x 30 sec at 175% of peak power output, with 4.5-min' rest between efforts. Immediately following HIT, heart rate and R-R intervals were monitored for 30-min during passive supine recovery. Autonomic modulation was examined by i) heart rate recovery in the first 60-sec of recovery (HRR 60 ); ii) the time constant of the 30-min heart rate recovery curve (HRRτ); iii) the time course of the root mean square for successive 30-sec R-R interval (RMSSD 30 ); and iv) time and frequency domain analyses of subsequent 5-min R-R interval segments. No significant between-group differences were observed for HRR 60 (P = 0.096) or HRR τ (P = 0.617). However, a significant interaction effect was found for RMSSD 30 (P = 0.021), with the master cyclists showing higher RMSSD 30 values following HIT. Similar results were observed in the time and frequency domain analyses with significant interaction effects found for the natural logarithm of the RMSSD (P = 0.008), normalised low-frequency power (P = 0.016) and natural logarithm of high-frequency power (P = 0.012). Following high-intensity interval training, master cyclists demonstrated greater post-exercise parasympathetic reactivation compared to young cyclists, indicating that physical training at older ages has significant effects on autonomic function.

Composite Material Aircraft Electromagnetic Properties and Design Guidelines

DTIC Science & Technology

1981-01-01

Diode Characteristics for IN914 Diode at 220 MHz 7-6 7.5 Characteristics of a 2N2369A Transitor With and Without RF Interference on the Collector Lead...Analylsi Miser Reiponse Model Adjacent Channel Interference Summary 7. STATISTICAL AND NUMERICAL I. PROPAGATION MODELS ANALYSIS MASTER PROPAGATION SYSTEM...Propagation System lIPS) Simsulationst Smorothe Curve Smooth Earth (SCSIS) Oemtralltzd File Statistics Analyzer (Q63) flislance Free Space Spherical Raflectiot

Thermodynamic scaling of dynamic properties of liquid crystals: Verifying the scaling parameters using a molecular model

NASA Astrophysics Data System (ADS)

Satoh, Katsuhiko

2013-08-01

The thermodynamic scaling of molecular dynamic properties of rotation and thermodynamic parameters in a nematic phase was investigated by a molecular dynamic simulation using the Gay-Berne potential. A master curve for the relaxation time of flip-flop motion was obtained using thermodynamic scaling, and the dynamic property could be solely expressed as a function of TV^{γ _τ }, where T and V are the temperature and volume, respectively. The scaling parameter γτ was in excellent agreement with the thermodynamic parameter Γ, which is the logarithm of the slope of a line plotted for the temperature and volume at constant P2. This line was fairly linear, and as good as the line for p-azoxyanisole or using the highly ordered small cluster model. The equivalence relation between Γ and γτ was compared with results obtained from the highly ordered small cluster model. The possibility of adapting the molecular model for the thermodynamic scaling of other dynamic rotational properties was also explored. The rotational diffusion constant and rotational viscosity coefficients, which were calculated using established theoretical and experimental expressions, were rescaled onto master curves with the same scaling parameters. The simulation illustrates the universal nature of the equivalence relation for liquid crystals.

THE NEW ECLIPSING CV MASTER OTJ192328.22+612413.5—A POSSIBLE SW SEXTANTIS STAR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kennedy, M. R.; Callanan, P.; Bouanane, S.

2016-07-01

We present optical photometry and spectroscopy of the new eclipsing cataclysmic variable MASTER OTJ192328.22+612413.5, discovered by the MASTER team. We find the orbital period to be P = 0.16764612(5) day/4.023507(1) hr. The depth of the eclipse (2.9 ± 0.1 mag) suggests that the system is nearly edge on, and modeling of the system confirms the inclination to be between 81.°3 and 83.°6. The brightness outside the eclipse varies between observations, with a change of 1.6 ± 0.1 mag. Spectroscopy reveals double-peaked Balmer emission lines. By using spectral features matching a late M-type companion, we bound the distance to be 750more » ± 250 pc, depending on the companion’s spectral type. The source displays 2 mag brightness changes on timescales of days. The amplitude of these changes, along with the spectrum at the faint state, suggest that the system is possibly a dwarf nova. The lack of any high-excitation He ii lines suggests that this system is not magnetically dominated. The light curve in both quiescence and outburst resembles that of Lanning 386, implying MASTER OTJ192328.22+612413.5 is a possible cross between a dwarf nova and a SW Sextantis star.« less

FLUID/MASHOV--A CAI System Based on Games, Dialogue, and Feedback.

ERIC Educational Resources Information Center

Regev, Joseph

1980-01-01

A master program to manage instruction and generate the necessary control cards was designed to both teach thinking skills and assist the teacher in assessing the student's thought processes. Twelve references are cited. (MER)

The Political Role of Officers

DTIC Science & Technology

2015-06-12

fulfillment of the requirements for the degree MASTER OF MILITARY ART AND SCIENCE General Studies by BERTRAND EPSTEIN, MAJOR...other governmental agency. (References to this study should include the foregoing statement.) iv ABSTRACT THE POLITICAL ROLE OF OFFICERS, by

Regional curve development and selection of a reference reach in the non-urban, lowland sections of the Piedmont physiographic province, Pennsylvania and Maryland

USGS Publications Warehouse

White, Kirk E.

2001-01-01

Stream-restoration projects utilizing naturalstream designs frequently are based on the bankfull- channel characteristics of a stream reach that is accommodating streamflow and sediment transport without excessive erosion or deposition. The bankfull channel is identified by the use of field indicators and confirmed with tools such as regional curves. Channel dimensions were surveyed at six streamflow-measurement stations operated by the U.S. Geological Survey in the Gettysburg-Newark Lowlands Section and Piedmont Lowlands Section of the Piedmont Physiographic Province in Pennsylvania and Maryland. Regional curves were developed from regression analyses of the relation between drainage area and cross-sectional area, mean depth, width, and streamflow of the bankfull channel. Regional curves were used to confirm the identification of the bankfull channel at a reference reach. Stream dimensions and characteristics of the reference reach were measured for extrapolation into the design of a steam-restoration project on Bermudian Creek in Adams County, Pa.Dimensions for cross-sectional area, mean depth, width, and computed streamflow of the bankfull channel in all surveyed riffle cross sections in the reference reach were within the 95-percent confidence interval bounding the regression line representing bankfull channel geometry in the Lowland Sections of the Piedmont Physiographic Province. The average bankfull cross-sectional area, bankfull mean depth, and computed bankfull discharge for riffle cross sections in the reference reach ranged from 15.4 to 16.5 percent less than estimates determined from the lowland regional curves. Average bankfull channel width was about 2 percent greater than estimates. Cross-sectional area, mean depth, and computed streamflow corresponding to the bankfull stage at the reference reach were 31.4, 44.4, and 9.6 percent less, respectively, than estimates derived from the regional curves developed by Dunne and Leopold in 1978. Average bankfull channel width at the reference reach was 16.7 percent greater than the Dunne and Leopold estimate.The concepts of regional curves and reference reaches can be valuable tools to support efforts in stream restoration. Practitioners of stream restoration need to recognize them as such and realize their limitations. The small number of stations available for analysis is a major limiting factor in the strength of the results of this investigation. Subjective selection criteria may have unnecessarily eliminated streamflow-measurement stations that could have been included in the regional curves. A bankfull discharge with a recurrence interval within the 1- to 2-year range was used as a criteria for confirmation of the bankfull stage at each streamflow-measurement station. Many researchers accept this range for recurrence interval of the bankfull discharge; however, literature provides contradictory evidence. The use of channel-characteristics data from a reference reach without any monitoring data to document the stability of the reference reach over time is a topic of debate.

A Holocene paleosecular variation from 14C-dated volcanic rocks in Western North America

USGS Publications Warehouse

Hagstrum, J.T.; Champion, D.E.

2002-01-01

A paleosecular variation (PSV) curve for western North America is presented on the basis of 94 virtual geomagnetic poles (VGPs) from dated volcanic rocks sampled at 446 sites. Approximately 60% of the paleomagnetic database has been previously published. A curve defined by "spherical smoothed splines" is fitted to the VGPs, ranked by the quality of the age determinations, where the data density is highest between 3690 and -30 years before present (B.P.) (A.D. 1950), between 7800 and 7050 years B.P., and between 14,060 and 12,700 years B.P. The younger segments of the curve derived from volcanic rocks are similar but less complex than other high-resolution PSV curves derived from lacustrine sediments, particularly the record at Fish Lake, Oregon. The PSV record from lava flows (PSVL), however, is perhaps more reliable in its general shape and chronology because of the higher fidelity of volcanic rocks as magnetic field recorders and because of the greater density of 14C dates. The new PSVL record provides a partial Holocene master curve for western North America and will be of particular value in dating geological and archeological materials using paleomagnetic directions.

Tool calibration system for micromachining system

DOEpatents

Miller, Donald M.

1979-03-06

A tool calibration system including a tool calibration fixture and a tool height and offset calibration insert for calibrating the position of a tool bit in a micromachining tool system. The tool calibration fixture comprises a yokelike structure having a triangular head, a cavity in the triangular head, and a port which communicates a side of the triangular head with the cavity. Yoke arms integral with the triangular head extend along each side of a tool bar and a tool head of the micromachining tool system. The yoke arms are secured to the tool bar to place the cavity around a tool bit which may be mounted to the end of the tool head. Three linear variable differential transformer's (LVDT) are adjustably mounted in the triangular head along an X axis, a Y axis, and a Z axis. The calibration insert comprises a main base which can be mounted in the tool head of the micromachining tool system in place of a tool holder and a reference projection extending from a front surface of the main base. Reference surfaces of the calibration insert and a reference surface on a tool bar standard length are used to set the three LVDT's of the calibration fixture to the tool reference position. These positions are transferred permanently to a mastering station. The tool calibration fixture is then used to transfer the tool reference position of the mastering station to the tool bit.

High strength semi-active energy absorbers using shear- and mixedmode operation at high shear rates

NASA Astrophysics Data System (ADS)

Becnel, Andrew C.

This body of research expands the design space of semi-active energy absorbers for shock isolation and crash safety by investigating and characterizing magnetorheological fluids (MRFs) at high shear rates ( > 25,000 1/s) under shear and mixed-mode operation. Magnetorheological energy absorbers (MREAs) work well as adaptive isolators due to their ability to quickly and controllably adjust to changes in system mass or impact speed while providing fail-safe operation. However, typical linear stroking MREAs using pressure-driven flows have been shown to exhibit reduced controllability as impact speed (shear rate) increases. The objective of this work is to develop MREAs that improve controllability at high shear rates by using pure shear and mixed shear-squeeze modes of operation, and to present the fundamental theory and models of MR fluids under these conditions. A proof of concept instrument verified that the MR effect persists in shear mode devices at shear rates corresponding to low speed impacts. This instrument, a concentric cylinder Searle cell magnetorheometer, was then used to characterize three commercially available MRFs across a wide range of shear rates, applied magnetic fields, and temperatures. Characterization results are presented both as flow curves according to established practice, and as an alternate nondimensionalized analysis based on Mason number. The Mason number plots show that, with appropriate correction coefficients for operating temperature, the varied flow curve data can be collapsed to a single master curve. This work represents the first shear mode characterization of MRFs at shear rates over 10 times greater than available with commercial rheometers, as well as the first validation of Mason number analysis to high shear rate flows in MRFs. Using the results from the magnetorheometer, a full scale rotary vane MREA was developed as part of the Lightweight Magnetorheological Energy Absorber System (LMEAS) for an SH-60 Seahawk helicopter crew seat. Characterization tests were carried out on the LMEAS using a 40 vol% MRF used in the previous magnetorheometer tests. These were analyzed using both flow curves and apparent viscosity vs. Mason number diagrams. The nondimensionalized Mason number analysis resulted in data for all conditions of temperature, fluid composition, and shear rate, to collapse onto a single characteristic or master curve. Significantly, the temperature corrected Mason number results from both the bench top magnetorheometer and full scale rotary vane MREA collapse to the same master curve. This enhances the ability of designers of MRFs and MREAs to safely and effectively apply characterization data collected in low shear rate, controlled temperature environments to operational environments that may be completely different. Finally, the Searle cell magnetorheometer was modified with an enforced eccentricity to work in both squeeze and shear modes simultaneously to achieve so called squeeze strengthening of the working MRF, thereby increasing the apparent yield stress and the specific energy absorption. By squeezing the active MR fluid, particles undergo compression-assisted aggregation into stronger, more robust columns which resist shear better than single chains. A hybrid model describing the squeeze strengthening behavior is developed, and recommendations are made for using squeeze strengthening to improve practical MREA devices.

Noninertial Multirelativity

NASA Astrophysics Data System (ADS)

Smarandache, Florentin

2012-10-01

We firstly propose an extension of Einstein's thought experiment with atomic clocks of the Special Theory of Relativity: considering non-constant accelerations and arbitrary 3D-curves for both a particle's speed and trajectory inside the rocket and respectively the rocket's speed and trajectory. And secondly we propose as research multiple reference frames F1, F2, , Fn moving on respectively arbitrary 3D-curves C1, C2, , Cn with respectively arbitrary non-constant accelerations a1, a2, , an and respectively initial velocities v1, v2, , vn. The reference frame Fi is moving with a nonconstant acceleration ai and initial velocity vi on a 3D-curve Ci with respect to another reference frame Fi+1 (where 1 <= i <= n-1).

Capturing method for integral three-dimensional imaging using multiviewpoint robotic cameras

NASA Astrophysics Data System (ADS)

Ikeya, Kensuke; Arai, Jun; Mishina, Tomoyuki; Yamaguchi, Masahiro

2018-03-01

Integral three-dimensional (3-D) technology for next-generation 3-D television must be able to capture dynamic moving subjects with pan, tilt, and zoom camerawork as good as in current TV program production. We propose a capturing method for integral 3-D imaging using multiviewpoint robotic cameras. The cameras are controlled through a cooperative synchronous system composed of a master camera controlled by a camera operator and other reference cameras that are utilized for 3-D reconstruction. When the operator captures a subject using the master camera, the region reproduced by the integral 3-D display is regulated in real space according to the subject's position and view angle of the master camera. Using the cooperative control function, the reference cameras can capture images at the narrowest view angle that does not lose any part of the object region, thereby maximizing the resolution of the image. 3-D models are reconstructed by estimating the depth from complementary multiviewpoint images captured by robotic cameras arranged in a two-dimensional array. The model is converted into elemental images to generate the integral 3-D images. In experiments, we reconstructed integral 3-D images of karate players and confirmed that the proposed method satisfied the above requirements.

An in vitro study to compare the accuracy of the master cast fabricated by four different transfer impression techniques for single-tooth implant replacement.

PubMed

Lahori, Manesh; Nagrath, Rahul; Agrawal, Prateek

2014-03-01

Single tooth implant retained crowns have become a recognized technique for the replacement of the missing teeth. With the predictable integration of implants, the emphasis is shifted towards precise prosthesis. Minor movement of the impression coping retained inside the impression material can occur during all the procedures, leading to the three-dimensional spatial inaccuracies in the master casts. Therefore, the present study was undertaken with the purpose to evaluate the accuracy of single-tooth implant impression techniques using four different impression copings, so as to obtain a precise definitive cast for a single-unit implant restoration. A maxillary acrylic resin model with a standard single implant in the first molar region was used to simulate a clinical situation. A total of 60 impressions were made with polyvinylsiloxane impression material, which were divided into four groups of 15 impressions each. Group I used non-modified square impression coping, while in group II, III and IV square impression coping were modified differently. Master casts fabricated for all the groups were analyzed to detect rotational position change of the hexagon on the implant replicas in the master casts in reference to the resin model. The master casts obtained with the roughened and adhesive-coated impression copings showed a lower amount of rotational movement than the masters casts achieved with the non-modified impression copings. Hence, the clinician should use sandblasted and adhesive coated impression copings to achieve a more accurate and precise orientation of the implant replicas in the laboratory master casts in single-tooth implant restorations.

Characterization of free volume during vulcanization of styrene butadiene rubber by means of positron annihilation lifetime spectroscopy and dynamic mechanical test.

PubMed

Marzocca, A J; Cerveny, S; Salgueiro, W; Somoza, A; Gonzalez, L

2002-02-01

An experimental investigation was performed to study the effect on the free volume of the advance of the cross-linking reaction in a copolymer of styrene butadiene rubber by sulfur vulcanization. The dynamic modulus and loss tangent were evaluated over samples cured for different times at 433 K by dynamic mechanical tests over a range of frequencies between 5 and 80 Hz at temperatures between 200 and 300 K. Using the William-Landel-Ferry relationship, master curves were obtained at a reference temperature of 298 K and the coefficients c(0)(1) and c(0)(2) were evaluated. From these parameters the dependence of the free volume on the cure time is obtained. Positron annihilation lifetime spectroscopy was also used to estimate the size and number density of free volume sites in the material. The spectra were analyzed in terms of continuous distributions of free volume size. The results suggest an increase of the lower free volume size when cross linking takes place. Both techniques give similar results for the dependence of free volume on the time of cure of the polymer.

Revised Reference Curves for Bone Mineral Content and Areal Bone Mineral Density According to Age and Sex for Black and Non-Black Children: Results of the Bone Mineral Density in Childhood Study

PubMed Central

Kalkwarf, Heidi J.; Gilsanz, Vicente; Lappe, Joan M.; Oberfield, Sharon; Shepherd, John A.; Frederick, Margaret M.; Huang, Xiangke; Lu, Ming; Mahboubi, Soroosh; Hangartner, Thomas; Winer, Karen K.

2011-01-01

Context: Deficits in bone acquisition during growth may increase fracture risk. Assessment of bone health during childhood requires appropriate reference values relative to age, sex, and population ancestry to identify bone deficits. Objective: The objective of this study was to provide revised and extended reference curves for bone mineral content (BMC) and areal bone mineral density (aBMD) in children. Design: The Bone Mineral Density in Childhood Study was a multicenter longitudinal study with annual assessments for up to 7 yr. Setting: The study was conducted at five clinical centers in the United States. Participants: Two thousand fourteen healthy children (992 males, 22% African-Americans) aged 5–23 yr participated in the study. Intervention: There were no interventions. Main Outcome Measures: Reference percentiles for BMC and aBMD of the total body, lumbar spine, hip, and forearm were obtained using dual-energy x-ray absorptiometry for Black and non-Black children. Adjustment factors for height status were also calculated. Results: Extended reference curves for BMC and aBMD of the total body, total body less head, lumbar spine, total hip, femoral neck, and forearm for ages 5–20 yr were constructed relative to sex and age for Black and non-Black children. Curves are similar to those previously published for 7–17 year olds. BMC and aBMD values were greater for Black vs. non-Black children at all measurement sites. Conclusions: We provide here dual-energy x-ray absorptiometry reference data on a well-characterized cohort of 2012 children and adolescents. These reference curves provide the most robust reference values for the assessment and monitoring of bone health in children and adolescents in the literature to date. PMID:21917867

Project Management Professional Development: An Industry Led Programme.

ERIC Educational Resources Information Center

Gale, Andrew; Brown, Mike

2003-01-01

Describes a modular master's program in project management. Explores relationships between return on investment, management competencies, and learning outcomes in the context of industry-academic partnerships. Discusses the managed learning environment using WebCT. (Contains 40 references.) (SK)

Postgraduate Education for Nurses: The Middlesex Model.

ERIC Educational Resources Information Center

Caldwell, Kay

2001-01-01

A British university's curriculum model for master's and postgraduate diploma nursing education is characterized by structured collaboration among students, clinical mentors, and academic supervisors. A professional development portfolio individualizes the program and facilitates autonomous learning. (Contains 21 references.) (SK)

Phonon Confinement Effect in TiO2 Nanoparticles as Thermosensor Materials

DTIC Science & Technology

2018-01-24

TiO2 or ZnO nanoparticles (NPs) have a very strong finite-size dependency in their Raman spectra or photoluminescence (PL) spectra due to the phonon...spectrometers were used to establish the particle size versus the Raman/PL peak position master curves. Systematic isothermal and temperature- dependent heat...Thermosensor Materials", Workshop on Time- Dependent Temperature Measurements in Energy Release Processes, Chicago, IL, 2012. 11 3) Ashish Kumar Mishra

Determination of Tafel Constants in Nonlinear Polarization Curves.

DTIC Science & Technology

1987-12-01

resulted in difficulty in determining the Tafel constants from such plots. A FORTRAN based program involving numerical differentiation techniques was...MASTER OF SCIENCE IN MECHANICAL ENGINEERING from the NAVAL POSTGRADUATE SCHOOL December 1987 Auho:Th as Edr L~oughlin Approved by: J erkins hesis Advisor...Inthony J.f Healey, Chai man, Departm o Mhnical E gineering ’ Gordon E. Schacher Dean of Science and Engineering 21 ABSTRACT The presence of non-linear

Data catalog series for space science and applications flight missions. Volume 6: Master index volume

NASA Technical Reports Server (NTRS)

Horowitz, Richard; Ross, Patricia A.; King, Joseph H.

1989-01-01

The main purpose of the data catalog series is to provide descriptive references to data generated by space science flight missions. The data sets described include all of the actual holdings of the Space Science Data Center (NSSDC), all data sets for which direct contact information is available, and some data collections held and serviced by foreign investigators, NASA, and other U.S. government agencies. This volume contains the Master Index. The following spacecraft are included: Mariner, Pioneer, Pioneer Venus, Venera, Viking, Voyager, and Helios. Separate indexes to the planetary and interplanetary missions are also provided.

Investing in a master's degree.

PubMed

Hodges, L C; Ganchorre, C; Hodges, E A

1997-10-01

One of the most important decisions you will ever make is the decision to invest your time and money in a master's degree. It is a big investment and often requires real sacrifice for you and your family. Since this decision is of paramount importance over the life of your career, it should be approached as a major topic to research. The first step in the process is a thorough review of your own goals and career expectations. Once you decide returning to graduate school is right for you, then you must turn your attention to finding the school that meets your goals for specialized study, as well as the location that best suits your lifestyle. A good place to start the search is in the library among a number of up-to-date references on master's nursing programs. A second source is the Internet. To find out more about the school locations, two good sources are the city's chamber of commerce and the Internet. Acquiring a master's degree in nursing will be a challenge, but one that will pay big dividends in your future nursing career.

OSD CALS Architecture Master Plan Study. Concept Paper. Indexing. Volume 30

DOT National Transportation Integrated Search

1989-06-01

An index identifies and reference information which is exchanged between multiple users and systems. The increased automation that will take place as CALS evolves will dictate an increased use of indexes for the successful exchange of information. Th...

Optimization of Composite Structures with Curved Fiber Trajectories

NASA Astrophysics Data System (ADS)

Lemaire, Etienne; Zein, Samih; Bruyneel, Michael

2014-06-01

This paper studies the problem of optimizing composites shells manufactured using Automated Tape Layup (ATL) or Automated Fiber Placement (AFP) processes. The optimization procedure relies on a new approach to generate equidistant fiber trajectories based on Fast Marching Method. Starting with a (possibly curved) reference fiber direction defined on a (possibly curved) meshed surface, the new method allows determining fibers orientation resulting from a uniform thickness layup. The design variables are the parameters defining the position and the shape of the reference curve which results in very few design variables. Thanks to this efficient parameterization, maximum stiffness optimization numerical applications are proposed. The shape of the design space is discussed, regarding local and global optimal solutions.

The CHPRC Columbia River Protection Project Quality Assurance Project Plan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fix, N. J.

Pacific Northwest National Laboratory researchers are working on the CHPRC Columbia River Protection Project (hereafter referred to as the Columbia River Project). This is a follow-on project, funded by CH2M Hill Plateau Remediation Company, LLC (CHPRC), to the Fluor Hanford, Inc. Columbia River Protection Project. The work scope consists of a number of CHPRC funded, related projects that are managed under a master project (project number 55109). All contract releases associated with the Fluor Hanford Columbia River Project (Fluor Hanford, Inc. Contract 27647) and the CHPRC Columbia River Project (Contract 36402) will be collected under this master project. Each projectmore » within the master project is authorized by a CHPRC contract release that contains the project-specific statement of work. This Quality Assurance Project Plan provides the quality assurance requirements and processes that will be followed by the Columbia River Project staff.« less

Black start research of the wind and storage system based on the dual master-slave control

NASA Astrophysics Data System (ADS)

Leng, Xue; Shen, Li; Hu, Tian; Liu, Li

2018-02-01

Black start is the key to solving the problem of large-scale power failure, while the introduction of new renewable clean energy as a black start power supply was a new hotspot. Based on the dual master-slave control strategy, the wind and storage system was taken as the black start reliable power, energy storage and wind combined to ensure the stability of the micorgrid systems, to realize the black start. In order to obtain the capacity ratio of the storage in the small system based on the dual master-slave control strategy, and the black start constraint condition of the wind and storage combined system, obtain the key points of black start of wind storage combined system, but also provide reference and guidance for the subsequent large-scale wind and storage combined system in black start projects.

Experimental investigations into visual and electronic tooth color measurement.

PubMed

Ratzmann, Anja; Treichel, Anja; Langforth, Gabriele; Gedrange, Tomasz; Welk, Alexander

2011-04-01

The present study aimed to examine the validity of the visual color assessment and an electronic tooth color measurement system by means of Shade Inspector™ in comparison with a gold standard. Additionally, reproducibility of electronic measurements was demonstrated by means of two reference systems. Ceramic specimens of two thicknesses (h=1.6 mm, h=2.6 mm) were used. Three experienced dental technicians using the VITAPAN Classical(®) color scale carried out all visual tests. Validity of the visual assessment and the electronic measurements was confirmed separately for both thicknesses by means of lightness and hue of the VITAPAN Classical(®) color scale. Reproducibility of electronic measurements was confirmed by means of the VITAPAN Classical(®) and 3D-Master(®). The 3D-Master(®) data were calculated according to lightness, hue and chroma. Intraclass correlation coefficient (ICC) was used in assessing validity/reproducibility for lightness and chroma, Kappa statistics were used for hue. A level ≥0.75 was pre-established for ICC and ≥0.60 for the Kappa index. RESULTS OF VISUAL COLOR ASSESSMENT: Validity for lightness was good for both thicknesses; agreement rates for hue were inconsistent. ELECTRONIC MEASUREMENT: Validity for lightness was fair to good, hue values were below 0.60. Reproducibility of lightness was good to very good for both reference systems. Hue values (VITAPAN Classical(®)) for 1.6 mm test specimens were upside, for 2.6 mm below 0.60, Kappa values for 3D-Master(®) were ≥0.60 for all measurements, reproducibility of chroma was very good. Validity was better for visual than for electronic color assessment. Reproducibility of the electronic device by means of the Shade Inspector™ was given for the VITAPAN Classical(®) and 3D-Master(®) systems.

Fatigue behavior of a cross-ply ceramic matrix composite subjected to tension-tension cycling with hold time. Master`s thesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grant, S.A.

This study was carried out to investigate the elevated temperature behavior of the SiC-MAS5 cross- ply (O/9O)4S ceramic matrix composite manufactured by Corning Inc. to fatigue with loading waveforms that combine the characteristics of stress rupture and high cycle fatigue. The test results were compiled in the form of S-N (cycles to failure), S-T (exposure time versus cycles to failure), S-S (energy exposure versus cycles to failure), normalized modulus degradation, strain progression, and hysteresis loop progression. From the mechanical behavior demonstrated by these curves, relationships between the effect of the environment and loading waveform were developed. In addition, a post-mortemmore » SEM analysis of the fracture surface was conducted and the results compared to the mechanical behavior.« less

A New Method of Preparing a Master Card from the "National Union Catalog"

ERIC Educational Resources Information Center

Schertz, Morris; Shavit, David

1971-01-01

The University of Denver is employing a new method for producing copy from the National Union Catalog" which has distinct advantages over other existing methods, particularly as far as cost per copy is concerned. (1 reference) (Author)

76 FR 24464 - Federal Register Notice Requesting Nominations for the Subcommittee on Data Standardization Under...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-02

... recommendations for a standardized reference data depository representing the universe of legal and financial... individual transactions, underlying legal documents (including master agreements and credit support... agencies, industry, exchanges, academia, information technology, information systems, and groups...

Observed Statistics of Extreme Waves

DTIC Science & Technology

2006-12-01

hardware used, the reader is referred to Tinder (2000) and Ardhuin et al., (2003). SHOWEX took place during a particularly active hurricane season...c10, 5925-5938. Tinder , C. V., (2000). Swell Transformation Across the Continental Shelf. Master’s Thesis, Naval Postgraduate School, Monterey

Library Science Education in Panjab.

ERIC Educational Resources Information Center

Bansal, G. C.; Tikku, U. K.

1988-01-01

Traces the history of library education in Panjab from 1915 to the present. Topics covered include curriculum design; bachelors, masters, and postgraduate programs offered by Panjab University; state training programs; the development of polytechnic schools for women; correspondence courses; and professional organizations. (7 references) (CLB)

Reference curve for the first-year growth response to growth hormone treatment in prepubertal children with idiopathic growth hormone deficiency: validation of the KIGS first-year growth response curve using the Belgian Register for the Study of Growth and Puberty Problems.

PubMed

Straetemans, Saartje; Roelants, Mathieu; Thomas, Muriel; Rooman, Raoul; De Schepper, Jean

2014-01-01

Comparing observed and expected growth after first-year growth hormone (GH) therapy is useful for identifying a poor growth response to GH. To generate a first-year, age-specific growth response reference curve for prepubertal Belgian children with idiopathic growth hormone deficiency (iGHD) treated with a standard weight-adjusted GH dose and to compare this national reference with the response references derived from KIGS. First-year height data of 357 prepubertal children (240 males) with iGHD were analyzed. Smooth reference curves of first-year height velocity (HV) in relation to age were created. Differences with the KIGS targets were evaluated after z-score transformation. The observed first-year HVs were log-normal distributed by age and decreased significantly with age (p<0.001). No GH dose or gender effect was observed (p=0.5). Distance to target height, severity of GHD and occurrence of multiple pituitary hormone deficiencies had a positive effect (p<0.01) on the calculated HV SDS. When applying the KIGS targets for severe iGHD, mean HV SDS was close to zero (-0.09±0.84). The developed age-specific growth response curves enable rapid identification of poor response to first-year GH treatment in prepubertal iGHD children. Our results validate the published growth targets derived from the KIGS database. © 2014 S. Karger AG, Basel.

Accelerated characterization of graphite/epoxy composites

NASA Technical Reports Server (NTRS)

Griffith, W. I.; Morris, D. H.; Brinson, H. F.

1980-01-01

A method to predict the long term compliance of unidirectional off-axis laminates from short term laboratory tests is presented. The method uses an orthotropic transformation equation and the time-stress-temperature superposition principle. Short term tests are used to construct master curves for two off-axis unidirectional laminates with fiber angles of 10 and 90 degrees. Analytical predictions of long term compliance for 30 and 60 degrees laminates are made. Comparisons with experimental data are also given.

Compilation of Abstracts of Theses Submitted by Candidates for Degrees.

DTIC Science & Technology

1982-05-01

which either ti- tanium or aluminum tubes are used in the heat exchanges . Master of Science in Advisor: R. H. Nunn Mechanical Engineering Department... Testing in an Inert Environment Holihan, R. G., Jr. Investigation of Heat Transfer in 208 LCDR, USN Straight and Curved Rectangular Ducts for Laminar...for c-ft materials fatigue testing . The system uses an HP-9835 Desktop . .tnr, an HP-2240A Measurement and Control Processor and a Materials P System

On the temperature independence of statistical model parameters for cleavage fracture in ferritic steels

NASA Astrophysics Data System (ADS)

Qian, Guian; Lei, Wei-Sheng; Niffenegger, M.; González-Albuixech, V. F.

2018-04-01

The work relates to the effect of temperature on the model parameters in local approaches (LAs) to cleavage fracture. According to a recently developed LA model, the physical consensus of plastic deformation being a prerequisite to cleavage fracture enforces any LA model of cleavage fracture to observe initial yielding of a volume element as its threshold stress state to incur cleavage fracture in addition to the conventional practice of confining the fracture process zone within the plastic deformation zone. The physical consistency of the new LA model to the basic LA methodology and the differences between the new LA model and other existing models are interpreted. Then this new LA model is adopted to investigate the temperature dependence of LA model parameters using circumferentially notched round tensile specimens. With the published strength data as input, finite element (FE) calculation is conducted for elastic-perfectly plastic deformation and the realistic elastic-plastic hardening, respectively, to provide stress distributions for model calibration. The calibration results in temperature independent model parameters. This leads to the establishment of a 'master curve' characteristic to synchronise the correlation between the nominal strength and the corresponding cleavage fracture probability at different temperatures. This 'master curve' behaviour is verified by strength data from three different steels, providing a new path to calculate cleavage fracture probability with significantly reduced FE efforts.

Viscosity scaling in concentrated dispersions and its impact on colloidal aggregation.

PubMed

Nicoud, Lucrèce; Lattuada, Marco; Lazzari, Stefano; Morbidelli, Massimo

2015-10-07

Gaining fundamental knowledge about diffusion in crowded environments is of great relevance in a variety of research fields, including reaction engineering, biology, pharmacy and colloid science. In this work, we determine the effective viscosity experienced by a spherical tracer particle immersed in a concentrated colloidal dispersion by means of Brownian dynamics simulations. We characterize how the effective viscosity increases from the solvent viscosity for small tracer particles to the macroscopic viscosity of the dispersion when large tracer particles are employed. Our results show that the crossover between these two regimes occurs at a tracer particle size comparable to the host particle size. In addition, it is found that data points obtained in various host dispersions collapse on one master curve when the normalized effective viscosity is plotted as a function of the ratio between the tracer particle size and the mean host particle size. In particular, this master curve was obtained by varying the volume fraction, the average size and the polydispersity of the host particle distribution. Finally, we extend these results to determine the size dependent effective viscosity experienced by a fractal cluster in a concentrated colloidal system undergoing aggregation. We include this scaling of the effective viscosity in classical aggregation kernels, and we quantify its impact on the kinetics of aggregate growth as well as on the shape of the aggregate distribution by means of population balance equation calculations.

Colombian reference growth curves for height, weight, body mass index and head circumference.

PubMed

Durán, Paola; Merker, Andrea; Briceño, Germán; Colón, Eugenia; Line, Dionne; Abad, Verónica; Del Toro, Kenny; Chahín, Silvia; Matallana, Audrey Mary; Lema, Adriana; Llano, Mauricio; Céspedes, Jaime; Hagenäs, Lars

2016-03-01

Published Growth studies from Latin America are limited to growth references from Argentina and Venezuela. The aim of this study was to construct reference growth curves for height, weight, body mass index (BMI) and head circumference of Colombian children in a format that is useful for following the growth of the individual child and as a tool for public health. Prospective measurements from 27 209 Colombian children from middle and upper socio-economic level families were processed using the generalised additive models for location, scale and shape (GAMLSS). Descriptive statistics for length and height, weight, BMI and head circumference for age are given as raw and smoothed values. Final height was 172.3 cm for boys and 159.4 cm for girls. Weight at 18 years of age was 64.0 kg for boys and 54 kg for girls. Growth curves are presented in a ± 3 SD format using logarithmic axes. The constructed reference growth curves are a start for following secular trends in Colombia and are also in the presented layout an optimal clinical tool for health care. ©2015 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

Near room temperature magnetocaloric properties and the universal curve of MnCoGe1-xCux

NASA Astrophysics Data System (ADS)

Si, Xiaodong; Liu, Yongsheng; Lu, Xiaofei; Shen, Yulong; Wang, Wenli; Yu, Wenying; Zhou, Tao; Gao, Tian

2017-05-01

Intermetallic compounds based on MnCoGe have drawn attention due to the coupled magnetic and structural transformations and the large magnetocaloric entropy. Here, we provide a systematic comparison of experimental data under different magnetic fields with magnetic and the magnetocaloric properties. The ferromagnetic transition temperature (TC) increases from 353.4(6) K for x = 0.01 to 363.4(4) K for x = 0.04 with increasing nominal copper content. The maximum magnetic entropy change |ΔSM| in a magnetic field change of 5 T is found to be 18.3(2) J/(kg K) with a large relative cooling power (RCP) value of 292.5(4) J/kg for x = 0.01, revealing that the present system can provide an acceptable magnetocaloric effect at a cheaper price for magnetic refrigeration materials. Making attempt to contrast a master curve for the present system, we find the experimental values of magnetic field dependence of the magnetic entropy change are consistent with a phenomenological universal curve.

A two step method to treat variable winds in fallout smearing codes. Master's thesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hopkins, A.T.

1982-03-01

A method was developed to treat non-constant winds in fallout smearing codes. The method consists of two steps: (1) location of the curved hotline (2) determination of the off-hotline activity. To locate the curved hotline, the method begins with an initial cloud of 20 discretely-sized pancake clouds, located at altitudes determined by weapon yield. Next, the particles are tracked through a 300 layer atmosphere, translating with different winds in each layer. The connection of the 20 particles' impact points is the fallout hotline. The hotline location was found to be independent of the assumed particle size distribution in the stabilizedmore » cloud. The off-hotline activity distribution is represented as a two-dimensional gaussian function, centered on the curved hotline. Hotline locator model results were compared to numerical calculations of hypothetical 100 kt burst and to the actual hotline produced by the Castle-Bravo 15 Mt nuclear test.« less

Modeling Interoperable Information Systems with 3LGM² and IHE.

PubMed

Stäubert, S; Schaaf, M; Jahn, F; Brandner, R; Winter, A

2015-01-01

Strategic planning of information systems (IS) in healthcare requires descriptions of the current and the future IS state. Enterprise architecture planning (EAP) tools like the 3LGM² tool help to build up and to analyze IS models. A model of the planned architecture can be derived from an analysis of current state IS models. Building an interoperable IS, i. e. an IS consisting of interoperable components, can be considered a relevant strategic information management goal for many IS in healthcare. Integrating the healthcare enterprise (IHE) is an initiative which targets interoperability by using established standards. To link IHE concepts to 3LGM² concepts within the 3LGM² tool. To describe how an information manager can be supported in handling the complex IHE world and planning interoperable IS using 3LGM² models. To describe how developers or maintainers of IHE profiles can be supported by the representation of IHE concepts in 3LGM². Conceptualization and concept mapping methods are used to assign IHE concepts such as domains, integration profiles actors and transactions to the concepts of the three-layer graph-based meta-model (3LGM²). IHE concepts were successfully linked to 3LGM² concepts. An IHE-master-model, i. e. an abstract model for IHE concepts, was modeled with the help of 3LGM² tool. Two IHE domains were modeled in detail (ITI, QRPH). We describe two use cases for the representation of IHE concepts and IHE domains as 3LGM² models. Information managers can use the IHE-master-model as reference model for modeling interoperable IS based on IHE profiles during EAP activities. IHE developers are supported in analyzing consistency of IHE concepts with the help of the IHE-master-model and functions of the 3LGM² tool The complex relations between IHE concepts can be modeled by using the EAP method 3LGM². 3LGM² tool offers visualization and analysis features which are now available for the IHE-master-model. Thus information managers and IHE developers can use or develop IHE profiles systematically. In order to improve the usability and handling of the IHE-master-model and its usage as a reference model, some further refinements have to be done. Evaluating the use of the IHE-master-model by information managers and IHE developers is subject to further research.

On the computer analysis of structures and mechanical systems

NASA Technical Reports Server (NTRS)

Bennett, B. E.

1984-01-01

The governing equations for the analysis of open branch-chain mechanical systems are developed in a form suitable for implementation in a general purpose finite element computer program. Lagrange's form of d'Alembert's principle is used to derive the system mass matrix and force vector. The generalized coordinates are selected as the unconstrained relative degrees of freedom giving the position and orientation of each slave link with respect to their master link. Each slave link may have from zero to six degrees of freedom relative to the reference frames of its master link. A strategy for automatic generation of the system mass matrix and force vector is described.

Teaching about Oil. Contemporary Issues for Young Citizens.

ERIC Educational Resources Information Center

Brady, Holly; Arnold, Anne Jurmu

1982-01-01

This teaching unit contains background information on the history of oil use and technology, suggestions for classroom activities, and a list of resources and references for elementary and secondary grades. Reproducible masters are provided showing gasoline production and major oil producers and consumers. (FG)

Context for Communication: Teaching Expertise through Case-Based In-Basket Exercises.

ERIC Educational Resources Information Center

Stearns, James M.; Ronald, Kate; Greenlee, Timothy B.; Crespy, Charles T.

2003-01-01

Case-based in-basket exercises require students to master content as well as communicate knowledge to professional audiences. The combination of specialized content knowledge and analysis of communication contexts helps develop expertise. (Contains 23 references and an in-basket example.) (SK)

Evolutionary space platform concept study. Volume 3: Programmatics for manned space platform concepts

NASA Technical Reports Server (NTRS)

1982-01-01

The programmatic data for the reference concept of the Manned Space Platform is presented. Details regarding work breakdown structure (WBS) and dictionary, the facilities and equipment required to produce the modules, the project schedule and logic diagram, a preliminary assessment of environmental impacts and details regarding the estimated costs for the reference concept are included. The proposed WBS which was developed to provide summary and system level segregation of the nonrecurring and recurring portions of the Manned Space Platform project is also included. The accompanying dictionary outlines the function and activities contained within each WBS element. The facility and equipment required to produce the various modules is discussed. Generally, required equipment is within the existing state of the art although the size of some of the items to be manufactured is a consideration. A preliminary manufacturing flow was also provided. The project schedules presented consist of the Master Project Summary Schedule, the Master Project Phasing Chart and the Logic Network.

PubMed Central

Weichert, Alexander; Hagen, Andreas; Tchirikov, Michael; Fuchs, Ilka B.; Henrich, Wolfgang; Entezami, Michael

2017-01-01

Introduction Doppler sonography of the uterine artery (UA) is done to monitor pregnancies, because the detected flow patterns are useful to draw inferences about possible disorders of trophoblast invasion. Increased resistance in the UA is associated with an increased risk of preeclampsia and/or intrauterine growth restriction (IUGR) and perinatal mortality. In the absence of standardized figures, the normal ranges of the various available reference curves sometimes differ quite substantially from one another. The causes for this are differences in the flow patterns of the UA depending on the position of the pulsed Doppler gates as well as branching of the UA. Because of the discrepancies between the different reference curves and the practical problems this poses for guideline recommendations, we thought it would be useful to create our own reference curves for Doppler measurements of the UA obtained from a singleton cohort under standardized conditions. Material and Methods This retrospective cohort study was carried out in the Department of Obstetrics of the Charité – Universitätsmedizin Berlin, the Department for Obstetrics and Prenatal Medicine of the University Hospital Halle (Saale) and the Center for Prenatal Diagnostics and Human Genetics Kurfürstendamm 199. Available datasets from the three study locations were identified and reference curves were generated using the LMS method. Measured values were correlated with age of gestation, and a cubic model and Box-Cox power transformation (L), the median (M) and the coefficient of variation (S) were used to smooth the curves. Results 103 720 Doppler examinations of the UA carried out in singleton pregnancies from the 11th week of gestation (10 + 1 GW) were analyzed. The mean pulsatility index (Mean PI) showed a continuous decline over the course of pregnancy, dropping to a plateau of around 0.84 between the 23rd and 27th GW, after which it decreased again. Conclusion Age of gestation, placental position, position of pulsed Doppler gates and branching of the UA can all change the flow pattern. The mean pulsatility index (Mean PI) showed a continuous decrease over time. There were significant differences between our data and alternative reference curves. A system of classifying Doppler studies and a reference curve adapted to the current technology are urgently required to differentiate better between physiological and pathological findings. PMID:28579623

Evaluation of PCR and high-resolution melt curve analysis for differentiation of Salmonella isolates.

PubMed

Saeidabadi, Mohammad Sadegh; Nili, Hassan; Dadras, Habibollah; Sharifiyazdi, Hassan; Connolly, Joanne; Valcanis, Mary; Raidal, Shane; Ghorashi, Seyed Ali

2017-06-01

Consumption of poultry products contaminated with Salmonella is one of the major causes of foodborne diseases worldwide and therefore detection and differentiation of Salmonella spp. in poultry is important. In this study, oligonucleotide primers were designed from hemD gene and a PCR followed by high-resolution melt (HRM) curve analysis was developed for rapid differentiation of Salmonella isolates. Amplicons of 228 bp were generated from 16 different Salmonella reference strains and from 65 clinical field isolates mainly from poultry farms. HRM curve analysis of the amplicons differentiated Salmonella isolates and analysis of the nucleotide sequence of the amplicons from selected isolates revealed that each melting curve profile was related to a unique DNA sequence. The relationship between reference strains and tested specimens was also evaluated using a mathematical model without visual interpretation of HRM curves. In addition, the potential of the PCR-HRM curve analysis was evaluated for genotyping of additional Salmonella isolates from different avian species. The findings indicate that PCR followed by HRM curve analysis provides a rapid and robust technique for genotyping of Salmonella isolates to determine the serovar/serotype.

Computerised curve deconvolution of TL/OSL curves using a popular spreadsheet program.

PubMed

Afouxenidis, D; Polymeris, G S; Tsirliganis, N C; Kitis, G

2012-05-01

This paper exploits the possibility of using commercial software for thermoluminescence and optically stimulated luminescence curve deconvolution analysis. The widely used software package Microsoft Excel, with the Solver utility has been used to perform deconvolution analysis to both experimental and reference glow curves resulted from the GLOw Curve ANalysis INtercomparison project. The simple interface of this programme combined with the powerful Solver utility, allows the analysis of complex stimulated luminescence curves into their components and the evaluation of the associated luminescence parameters.

Body composition indices of a load-capacity model: gender- and BMI-specific reference curves.

PubMed

Siervo, Mario; Prado, Carla M; Mire, Emily; Broyles, Stephanie; Wells, Jonathan C K; Heymsfield, Steven; Katzmarzyk, Peter T

2015-05-01

Fat mass (FM) and fat-free mass (FFM) are frequently measured to define body composition phenotypes. The load-capacity model integrates the effects of both FM and FFM to improve disease-risk prediction. We aimed to derive age-, gender- and BMI-specific reference curves of load-capacity model indices in an adult population (≥18 years). Cross-sectional study. Dual-energy X-ray absorptiometry was used to measure FM, FFM, appendicular skeletal muscle mass (ASM) and truncal fat mass (TrFM). Two metabolic load-capacity indices were calculated: ratio of FM (kg) to FFM (kg) and ratio of TrFM (kg) to ASM (kg). Age-standardised reference curves, stratified by gender and BMI (<25.0 kg/m2, 25.0-29.9 kg/m2, ≥30.0 kg/m2), were constructed using an LMS approach. Percentiles of the reference curves were 5th, 15th, 25th, 50th, 75th, 85th and 95th. Secondary analysis of data from the 1999-2004 National Health and Nutrition Examination Survey (NHANES). The population included 6580 females and 6656 males. The unweighted proportions of obesity in males and females were 25.5 % and 34.7 %, respectively. The average values of both FM:FFM and TrFM:ASM were greater in female and obese subjects. Gender and BMI influenced the shape of the association of age with FM:FFM and TrFM:ASM, as a curvilinear relationship was observed in female and obese subjects. Menopause appeared to modify the steepness of the reference curves of both indices. This is a novel risk-stratification approach integrating the effects of high adiposity and low muscle mass which may be particularly useful to identify cases of sarcopenic obesity and improve disease-risk prediction.

Accelerated characterization of graphite/epoxy composites

NASA Technical Reports Server (NTRS)

Griffith, W. I.; Morris, D. H.; Brinson, H. F.

1980-01-01

A method to predict the long-term compliance of unidirectional off-axis laminates from short-term laboratory tests is presented. The method uses an orthotropic transformation equation and the time-stress-temperature superposition principle. Short-term tests are used to construct master curves for two off-axis unidirectional laminates with fiber angles of 10 deg and 90 deg. In addition, analytical predictions of long-term compliance for 30 deg and 60 deg laminates are made. Comparisons with experimental data are also given.

Prediction of long-term transverse creep compliance in high-temperature IM7/LaRC-RP46 composites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yuan, F.G.; Potter, B.D.

1994-12-31

An experimental study is performed which predicts long-term tensile transverse creep compliance of high-temperature IM7/LaRC-RP46 composites from short-term creep and recovery tests. The short-term tests were conducted for various stress levels at various fixed temperatures. Predictive nonlinear viscoelastic model developed by Schapery and experimental procedure were used to predict the long-term results in terms of master curve extrapolated from short-term tests.

46 CFR 153.933 - Chemical protective clothing.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 5 2011-10-01 2011-10-01 false Chemical protective clothing. 153.933 Section 153.933... § 153.933 Chemical protective clothing. When table 1 refers to this section, the following apply: (a) The master shall ensure that the following chemical protective clothing constructed of materials...

46 CFR 153.933 - Chemical protective clothing.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Chemical protective clothing. 153.933 Section 153.933... § 153.933 Chemical protective clothing. When table 1 refers to this section, the following apply: (a) The master shall ensure that the following chemical protective clothing constructed of materials...

Admitting At-Risk Students into a Principal Preparation Program: Predicting Success.

ERIC Educational Resources Information Center

Malone, Bobby G.; Nelson, Jacquelyn S.; Nelson, C. Van

2001-01-01

Study of graduation rates of at-risk students admitted to a master's degree program at a doctoral-degree-granting university found that the best predictor of degree completion was the product of the undergraduate GPA multiplied by the GRE Verbal score. (Contains 41 references.)

Grading for Understanding--Standards-Based Grading

ERIC Educational Resources Information Center

Zimmerman, Todd

2017-01-01

Standards-based grading (SBG), sometimes called learning objectives-based assessment (LOBA), is an assessment model that relies on students demonstrating mastery of learning objectives (sometimes referred to as standards). The goal of this grading system is to focus students on mastering learning objectives rather than on accumulating points. I…

46 CFR 153.933 - Chemical protective clothing.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 5 2014-10-01 2014-10-01 false Chemical protective clothing. 153.933 Section 153.933... § 153.933 Chemical protective clothing. When table 1 refers to this section, the following apply: (a) The master shall ensure that the following chemical protective clothing constructed of materials...

46 CFR 153.933 - Chemical protective clothing.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 5 2013-10-01 2013-10-01 false Chemical protective clothing. 153.933 Section 153.933... § 153.933 Chemical protective clothing. When table 1 refers to this section, the following apply: (a) The master shall ensure that the following chemical protective clothing constructed of materials...

46 CFR 153.933 - Chemical protective clothing.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 5 2012-10-01 2012-10-01 false Chemical protective clothing. 153.933 Section 153.933... § 153.933 Chemical protective clothing. When table 1 refers to this section, the following apply: (a) The master shall ensure that the following chemical protective clothing constructed of materials...

Thermal Pollution by Nuclear Power Plants. A Learning Experience for Coastal and Oceanic Awareness Studies, No. 320. [Project COAST].

ERIC Educational Resources Information Center

Delaware Univ., Newark. Coll. of Education.

This publication includes several activities regarding the use of nuclear power plants and possible effects on the environment. The materials are designed for secondary school students and include reference materials and masters for transparencies. (RH)

Normative Standards for HRpQCT Parameters in Chinese Men and Women.

PubMed

Zhu, Tracy Y; Yip, Benjamin Hk; Hung, Vivian Wy; Choy, Carol Wy; Cheng, Ka-Lo; Kwok, Timothy Cy; Cheng, Jack Cy; Qin, Ling

2018-06-12

Assessing bone architecture using high resolution peripheral quantitative computed tomography (HRpQCT) has the potential to improve fracture risk assessment. The Normal Reference Study aimed to establish sex-specific reference centile curves for HRpQCT parameters. This was an age-stratified cross-sectional study and 1,072 ambulatory Chinese men (n = 544) and women (n = 528) aged 20-79yrs, who were free from conditions and medications that could affect bone metabolism and had no history of fragility fracture, were recruited from local communities of Hong Kong. Reference centile curves for each HRpQCT parameter were constructed using Generalized Additive Models for Location, Scale and Shape with age as the only explanatory variable. Patterns of reference centile curves reflected age-related changes of bone density, microarchitecture, and estimated bone strength. In both sexes, loss of cortical bone was only evident in mid-adulthood, particularly in women with a more rapid fashion probably concurrent with the onset of menopause. In contrast, loss of trabecular bone was subtle or gradual or occurred at an earlier age. Expected values of HRpQCT parameters for a defined sex and age, and a defined percentile or z-score were obtained from these curves. T-scores were calculated using the population with the peak values as the reference and reflected age- or menopause-related bone loss in an older individual or the room to reach the peak potential in a younger individual. These reference centile curves produced a standard describing a norm or desirable target that enables value clinical judgements. Percentiles, z-scores and T-scores would be helpful in detecting abnormalities in bone density and microarchitecture arising from various conditions and establishing entry criteria for clinical trials. They also hold the potential to refine the diagnosis of osteoporosis and assessment of fracture risk. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Dual energy X-ray absorptiometry body composition reference values of limbs and trunk from NHANES 1999–2004 with additional visualization methods

PubMed Central

Fan, Bo; Ng, Bennett K.; Shepherd, John A.

2017-01-01

Body Mass Index has traditionally been used as a measure of health, but Fat Mass Index (FMI) and Lean Mass Index (LMI) have been shown to be more predictive of mortality and health risk. Total body FMI and LMI reference curves have particularly been useful in quantifying sarcopenia and sarcopenic obesity. Research has shown regional composition has significant associations to health outcomes. We derived FMI and LMI reference curves of the regions of the body (leg, arm, and trunk) for 15,908 individuals in the 1999–2004 National Health and Nutrition Examination Survey data for each sex and ethnicity using the Lambda-Mu-Sigma (LMS) method and developed software to visualize this regional composition. These reference curves displayed differentiation between males and females during puberty and sharper limb LMI declines during late adulthood for males. For adults ages 30–50, females had 39%, 83%, and 47% larger arm, leg, and trunk FMI values than males, respectively. Males had 49%, 20%, and 15% higher regional LMI values than females for the arms, legs, and trunk respectively. The leg FMI and LMI of black females were 14% and 15% higher respectively than those of Hispanic and white females. White and Hispanic males had 37% higher trunk FMI values than black males. Hispanic females had 20% higher trunk FMI than white and black females. These data underscore the importance of accounting for sex and ethnicity in studies of regional composition. This study is the first to produce regional LMI and FMI reference tables and curves from the NHANES dataset. These reference curves provide a framework useful in studies and research involving sarcopenia, obesity, sarcopenic obesity, and other studies of compositional phenotypes. Further, the software tool we provide for visualizing regional composition will prove useful in monitoring progress in physical therapy, diets, or other attempts to attain healthier compositions. PMID:28346492

Reference clock parameters for digital communications systems applications

NASA Technical Reports Server (NTRS)

Kartaschoff, P.

1981-01-01

The basic parameters relevant to the design of network timing systems describe the random and systematic time departures of the system elements, i.e., master (or reference) clocks, transmission links, and other clocks controlled over the links. The quantitative relations between these parameters were established and illustrated by means of numerical examples based on available measured data. The examples were limited to a simple PLL control system but the analysis can eventually be applied to more sophisticated systems at the cost of increased computational effort.

Casting and Angling.

ERIC Educational Resources Information Center

Little, Mildred J.; Bunting, Camille

The self-contained packet contains background information, lesson plans, 15 transparency and student handout masters, drills and games, 2 objective examinations, and references for teaching a 15-day unit on casting and angling to junior high and senior high school students, either as part of a regular physical education program or as a club…

Applying ABC Analysis to the Navy’s Inventory Management System

DTIC Science & Technology

2014-09-01

degree of MASTER OF SCIENCE IN OPERATIONS RESEARCH from the NAVAL POSTGRADUATE SCHOOL September 2014 Author: Benjamin May...Chair, Department of Operations Research iv THIS PAGE INTENTIONALLY LEFT BLANK v ABSTRACT ABC Analysis is an inventory categorization technique...FUTURE RESEARCH ..................................................................................75  LIST OF REFERENCES

"Forward To the Past": Africentric Rites of Passage.

ERIC Educational Resources Information Center

Hill, Paul, Jr.

No ceremony or rite exists to usher the African American male youth into proper manhood. Such ceremonies, referred to as rites of passage, mark commonly agreed-upon standards, activities, tasks, and trials that each youth must master to achieve the community-sanctioned title "man." The clear articulation and subsequent implementation of…

A Planning Guide for Instructional Networks, Part I.

ERIC Educational Resources Information Center

Daly, Kevin F.

1994-01-01

Discusses three phases in implementing a master plan for a school-based local area network (LAN): (1) network software selection; (2) hardware selection, network topology, and site preparation; and (3) implementation time table. Sample planning and specification worksheets and a list of planning guides are included. (Contains six references.) (KRN)

Experiential Education as a Teaching Strategy.

ERIC Educational Resources Information Center

Massey, Sara R.

This experiential education course was designed as part of an experimental program in education leading to a master's degree for teachers and administrators living in an isolated, rural area in Maine. Course outline, assignments, references, and lesson plans are provided. Elementary aspects of archaeology were used as the content from which to…

Literature in the Modern Languages Curriculum of British Universities.

ERIC Educational Resources Information Center

Bayley, Susan N.

1994-01-01

Examines the changes in the literature department of modern language curriculum and assesses their significance in terms of the past and future of literature as a component of the modern languages degree. The teaching of literature is trying to serve two masters: liberal humanism and utilitarianism. (32 references) (CK)

[The representation of physical pain in art and the Greek escultural group of the Laocoonte].

PubMed

Roqué, M H; Ruival, C; Roqué, C M

2006-01-01

It makes reference to the symptoms and signs of external pain and internal man suffering, masterly represented on marble by greek sculptors of Ancient Greece. A demonstration of the importance of literature and sculpture as an humanistic complement for teaching History of Medicine.

30 CFR 250.1202 - Liquid hydrocarbon measurement.

Code of Federal Regulations, 2010 CFR

2010-07-01

... the API MPMS as incorporated by reference in 30 CFR 250.198, when obtaining net standard volume and... (retrograde) condensate volumes as allocated to the individual leases or units. (b) What are the requirements... displacement (pipe) prover, master meter, or tank prover; (iii) A proportional-to-flow sampling device pulsed...

30 CFR 250.1202 - Liquid hydrocarbon measurement.

Code of Federal Regulations, 2011 CFR

2011-07-01

... chapters of the API MPMS as incorporated by reference in 30 CFR 250.198, when obtaining net standard volume... pipeline (retrograde) condensate volumes as allocated to the individual leases or units. (b) What are the... displacement (pipe) prover, master meter, or tank prover; (iii) A proportional-to-flow sampling device pulsed...

M.L.S. to Excess? Degree Requirements for ILL.

ERIC Educational Resources Information Center

Divens, W. C.

1995-01-01

Using published studies and references, shows why the requirement that a manager of interlibrary loan be a librarian with a master's degree in Library Science may be outmoded in the modern academic library. Discusses the librarian's role, certification and professional elitism, job requirements, and user needs. (AEF)

Rebalance to Asia and the Pacific: Leveraging Vietnam to Counter-Balance China

DTIC Science & Technology

2016-06-10

Army Command and General Staff College in partial fulfillment of the requirements for the degree MASTER OF MILITARY ART AND SCIENCE Strategic......the U.S. Army Command and General Staff College or any other governmental agency. (References to this study should include the foregoing statement

Rapid prototyping of interfacing microcomponents for printed circuit board-level optical interconnects

NASA Astrophysics Data System (ADS)

Van Erps, Jürgen; Vervaeke, Michael; Thienpont, Hugo

2012-01-01

One of the important challenges for the deployment of the emerging breed of nanotechnology components is interfacing them with the external world, preferably accomplished with low-cost micro-optical devices. For the fabrication of this kind of micro-optical components, we make use of deep proton writing (DPW) as a generic rapid prototyping technology. DPW consists of bombarding polymer samples with swift protons, which results after chemical processing steps in high quality micro-optical components. The strength of the DPW micro-machining technology is the ability to fabricate monolithic building blocks that include micro-optical and mechanical functionalities which can be precisely integrated into more complex photonic systems. In this paper we give an overview of the process steps of the technology and we present several examples of micro-optical and micro-mechanical components, fabricated through DPW, targeting applications in printed circuit baordlevel optical interconnections. These include: high-precision 2-D fiber connectors, discrete out-of-plane coupling structures featuring high-quality 45° and curved micro-mirrors, arrays of high aspect ratio micro-pillars and backplane connectors. While DPW is clearly not a mass fabrication technique as such, one of its assets is that once the master component has been prototyped, a metal mould can be generated from the DPW master by applying electroplating. After removal of the plastic master, this metal mould can be used as a shim in a final microinjection moulding or hot embossing step. This way, the master component can be mass-produced at low cost in a wide variety of high-tech plastics.

A nanocrystal-based formulation improves the pharmacokinetic performance and therapeutic response of albendazole in dogs.

PubMed

Paredes, Alejandro Javier; Litterio, Nicolás; Dib, Alicia; Allemandi, Daniel Alberto; Lanusse, Carlos; Bruni, Sergio Sánchez; Palma, Santiago Daniel

2018-01-01

Here, we aimed to assess the pharmacokinetic performance and therapeutic response (anthelmintic efficacy) of an albendazole (ABZ) nano-sized formulation in dogs. In the pharmacokinetic study, ABZ self-dispersible nanocrystals (SDNCS) and a control formulation were administered orally to healthy dogs (n = 6). The concentrations of the sulphoxide metabolite in plasma were determined by high-performance liquid chromatography. For the anthelmintic efficacy trial, SDNCS and a commercially available formulation of ABZ were given to naturally parasitised dogs. The number of Ancylostoma caninum eggs in the faeces was determined using the McMaster technique. The area under the curve, Tmax and Cmax for the SDNCS were improved compared to the control. The efficacy study showed no statistical differences between the SDNCS and the commercial formulation at the doses of 25 and 12.5 mg/kg. However, significant differences (P < 0.05) between the treatments were found at 6.25 mg/kg (a quarter of the reference dose) with a reduction in the faecal nematode egg counts of 62.0 ± 21.1% and 100 ± 0% for the control and SDNCS, respectively. The improved pharmacokinetic performance observed for the novel formulation of ABZ correlated with an improved in vivo therapeutic response against a model intestinal nematode parasite in dogs. © 2017 Royal Pharmaceutical Society.

Evaluation of fracture toughness master curve shifts for JMTR irradiated F82H using small specimens

NASA Astrophysics Data System (ADS)

Yamamoto, T.; Odette, G. R.; Gragg, D.; Kurishita, H.; Matsui, H.; Yang, W. J.; Narui, M.; Yamazaki, M.

2007-08-01

Small to ultra-small 1/3 size pre-cracked Charpy and 1.65 × 1.65 × 9 mm deformation and fracture minibeam (DFMB) specimens of the F82H IEA heat were irradiated to 0.02 and 0.12 dpa at 290 °C in the Japanese Materials Test Reactor. Nominal cleavage transition temperature shifts, based on the measured toughness, KJm( T), data (Δ Tm) as well as reference temperature shifts (Δ T0) found after size-adjusting the KJm( T) data yielded Δ Tm/0 ≈ 27 ± 10 and 44 ± 10 at the two doses, respectively. Using measured yield stress changes (Δ σy), the C0 = Δ T0/Δ σy = 0.58 ± 0.14 at 0.12 dpa, is in good agreement with data in the literature. The dynamic transition temperature shift, Δ Td, derived from DFMB tests, was ≈30 ± 20 °C at 0.1 dpa, also in good agreement with the estimated Δ T0 shifts. The Δ Td and Δ T0 are also in excellent agreement with a Δ T0 = C 0Δ σy (dpa, Ti) hardening-shift model, where the Δ σy (dpa, Ti) was found by fitting a large database of tensile properties.

Electronic data collection for the analysis of surgical maneuvers on patients submitted to rhinoplasty

PubMed Central

Berger, Cezar; Freitas, Renato; Malafaia, Osvaldo; Pinto, José Simão de Paula; Mocellin, Marcos; Macedo, Evaldo; Fagundes, Marina Serrato Coelho

2012-01-01

Summary Introduction: In the health field, computerization has become increasingly necessary in professional practice, since it facilitates data recovery and assists in the development of research with greater scientific rigor. Objective: the present work aimed to develop, apply, and validate specific electronic protocols for patients referred for rhinoplasty. Methods: The prospective research had 3 stages: (1) preparation of theoretical data bases; (2) creation of a master protocol using Integrated System of Electronic Protocol (SINPE©); and (3) elaboration, application, and validation of a specific protocol for the nose and sinuses regarding rhinoplasty. Results: After the preparation of the master protocol, which dealt with the entire field of otorhinolaryngology, we idealized a specific protocol containing all matters related to the patient. In particular, the aesthetic and functional nasal complaints referred for surgical treatment (i.e., rhinoplasty) were organized into 6 main hierarchical categories: anamnesis, physical examination, complementary exams, diagnosis, treatment, and outcome. This protocol utilized these categories and their sub-items: finality; access; surgical maneuvers on the nasal dorsum, tip, and base; clinical evolution after 3, 6, and 12 months; revisional surgery; and quantitative and qualitative evaluations. Conclusion: The developed electronic-specific protocol is feasible and important for information registration from patients referred to rhinoplasty. PMID:25991979

Prediction of Long-Term Strength of Thermoplastic Composites Using Time-Temperature Superposition. Degree awarded by Texas A&M Univ., May 1998

NASA Technical Reports Server (NTRS)

Reeder, James R.

2002-01-01

Accelerated tests for composite failure were investigated. Constant ramp transverse strength tests on thermoplastic composite specimens were conducted at four temperatures from 300 F to 450 F and five duration times from 0.5 sec to 24 hrs. Up to 400 F, the time-temperature-superposition method produces a master curve allowing strength at longer times to be estimated from strength tests conducted over shorter times but at higher temperatures. The shift factors derived from compliance tests applied well to the strength data. To explain why strength behaved similar to compliance, a viscoelastic fracture model was investigated based on the hypothesis that the work of fracture for crack initiation at some critical flaw remains constant with time and temperature. The model, which used compliance as input, was found to fit the strength data only if the critical fracture energy was allowed to vary with stress rate. Fracture tests using double cantilever beam specimens were conducted from 300 F to 450 F over time scales similar to the strength study. The toughness data showed a significant change with loading rate, less variation with temperature, did not form a master curve, and could not be correlated with the fracture model. Since the fracture model did not fit the fracture data, an alternative explanation based on the dilatational strain energy density was proposed. However the usefulness of this model is severely limited because it relies on a critical parameter which varies with loading rate.

Thermal aging of traditional and additively manufactured foams: analysis by time-temperature-superposition, constitutive, and finite-element models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maiti, A.; Weisgraber, T. H.; Small, W.

Cellular solids or foams are a very important class of materials with diverse applications ranging from thermal insulation and shock absorbing support cushions, to light-weight structural and floatation components, and constitute crucial components in a large number of industries including automotive, aerospace, electronics, marine, biomedical, packaging, and defense. In many of these applications the foam material is subjected to long periods of continuous stress, which can, over time, lead to a permanent change in structure and a degradation in performance. In this report we summarize our modeling efforts to date on polysiloxane foam materials that form an important component inmore » our systems. Aging of the materials was characterized by two measured quantities, i.e., compression set and load retention. Results of accelerated aging experiments were analyzed by an automated time-temperaturesuperposition (TTS) approach, which creates a master curve that can be used for long-term predictions (over decades) under ambient conditions. When comparing such master curves for traditional (stochastic) foams with those for recently 3D-printed (i.e., additively manufactured, or AM) foams, it became clear that AM foams have superior aging behavior. To gain deeper understanding, we imaged the microstructure of both foams using X-ray computed tomography, and performed finite-element analysis of the mechanical response within these microstructures. This indicates a wider stress variation in the stochastic foam with points of more extreme local stress as compared to the 3D printed material.« less

3D shape recovery of a newborn skull using thin-plate splines.

PubMed

Lapeer, R J; Prager, R W

2000-01-01

The objective of this paper is to construct a mesh-model of a newborn skull for finite element analysis to study its deformation when subjected to the forces present during labour. The current state of medical imaging technology has reached a level which allows accurate visualisation and shape recovery of biological organs and body-parts. However, a sufficiently large set of medical images cannot always be obtained, often because of practical or ethical reasons, and the requirement to recover the shape of the biological object of interest has to be met by other means. Such is the case for a newborn skull. A method to recover the three-dimensional (3D) shape from (minimum) two orthogonal atlas images of the object of interest and a homologous object is described. This method is based on matching landmarks and curves on the orthogonal images of the object of interest with corresponding landmarks and curves on the homologous or 'master'-object which is fully defined in 3D space. On the basis of this set of corresponding landmarks, a thin-plate spline function can be derived to warp from the 'master'-object space to the 'slave'-object space. This method is applied to recover the 3D shape of a newborn skull. Images from orthogonal view-planes are obtained from an atlas. The homologous object is an adult skull, obtained from CT-images made available by the Visible Human Project. After shape recovery, a mesh-model of the newborn skull is generated.

Sintering Behavior of Nanocrystalline Silicon Carbide Using a Plasma Pressure Compaction System: Master Sintering Curve Analysis

NASA Astrophysics Data System (ADS)

Bothara, Manish G.; Atre, Sundar V.; Park, Seong-Jin; German, Randall M.; Sudarshan, T. S.; Radhakrishnan, R.

2010-12-01

Nanostructured ceramics offer significant improvements in properties over corresponding materials with larger grain sizes on the order of tens to hundreds of micrometers. Silicon carbide (SiC) samples with grain sizes on the order of 100 nm can result in improved strength, chemical resistance, thermal stability, and tailored electrical resistivity. In this study, nanocrystalline SiC was processed in a plasma pressure compaction (P2C) system at a temperature of 1973 K (1700 °C) that was much lower than the temperatures reported for other sintering techniques. Microstructure of the resulting samples was studied and the hardness and the fracture toughness were measured. The grain sizes were on the order of 700 nm, the hardness between 22 and 24 GPa, and the toughness between 5 and 6.5 MPa·m1/2. The master sintering curve (MSC) analysis was used to model the densification behavior of SiC powder sintered by the P2C method. The apparent activation energies for three different pressures of 10, 30, and 50 MPa were obtained to be 1666, 1034, and 1162 kJ/mol, respectively. Although densification occurs via diffusion, the activation energies were higher than those associated with self-diffusion in SiC (between 570 and 920 kJ/mol). A validation study of the MSC was also conducted and the variation in observed density from the density predicted by the MSC was found to range from 1 to 10 pct.

An Innovative Concept for Testing Rutting Susceptibility of Asphalt Mixture

NASA Astrophysics Data System (ADS)

Mohseni, Alaeddin; Azari, Haleh

Currently, flow number (FN) is being used for measuring permanent deformation resistance of asphalt mixtures. The provisional AASHTO TP 79-10 test method specifies the requirements of the FN test; however, there are undefined levels of test variables, such as temperature, axial stress, and confinement. Therefore, agreeable FN criteria that can reliably discriminate between various mixtures have not been established yet. As the asphalt industry continues to develop more sophisticated mixtures (Warm Mix, RAP and RAS), the FN value has failed to capture the true complexity of the asphalt mixtures. These shortcomings and the unpredictable testing time of the FN test have affected its usefulness for evaluating high temperature performance of asphalt mixtures. A new test procedure for evaluation of rutting susceptibility of asphalt mixtures is being proposed. The new procedure is conducted at one temperature and multiple stresses on the same replicate in three increments of 500 cycles, which only takes 33 minutes to complete. The property of the test is the permanent strain due to the last cycle of each test increment (Minimum Strain Rate, or MSR). A master curve is developed by plotting the MSR values versus parameter TP, which is a product of Temperature and Pressure. The MSR master curve represents the unit rutting damage (rut per axle) of asphalt mixtures at any stress and temperature and can be used in laboratory for material characterization, mix design verification, ranking of the mixtures, or for pavement design applications to predict rut depth for project climate and design traffic.

Learning curves for transapical transcatheter aortic valve replacement in the PARTNER-I trial: Technical performance, success, and safety.

PubMed

Suri, Rakesh M; Minha, Sa'ar; Alli, Oluseun; Waksman, Ron; Rihal, Charanjit S; Satler, Lowell P; Greason, Kevin L; Torguson, Rebecca; Pichard, Augusto D; Mack, Michael; Svensson, Lars G; Rajeswaran, Jeevanantham; Lowry, Ashley M; Ehrlinger, John; Mick, Stephanie L; Tuzcu, E Murat; Thourani, Vinod H; Makkar, Raj; Holmes, David; Leon, Martin B; Blackstone, Eugene H

2016-09-01

Introduction of hybrid techniques, such as transapical transcatheter aortic valve replacement (TA-TAVR), requires skills that a heart team must master to achieve technical efficiency: the technical performance learning curve. To date, the learning curve for TA-TAVR remains unknown. We therefore evaluated the rate at which technical performance improved, assessed change in occurrence of adverse events in relation to technical performance, and determined whether adverse events after TA-TAVR were linked to acquiring technical performance efficiency (the learning curve). From April 2007 to February 2012, 1100 patients, average age 85.0 ± 6.4 years, underwent TA-TAVR in the PARTNER-I trial. Learning curves were defined by institution-specific patient sequence number using nonlinear mixed modeling. Mean procedure time decreased from 131 to 116 minutes within 30 cases (P = .06) and device success increased to 90% by case 45 (P = .0007). Within 30 days, 354 patients experienced a major adverse event (stroke in 29, death in 96), with possibly decreased complications over time (P ∼ .08). Although longer procedure time was associated with more adverse events (P < .0001), these events were associated with change in patient risk profile, not the technical performance learning curve (P = .8). The learning curve for TA-TAVR was 30 to 45 procedures performed, and technical efficiency was achieved without compromising patient safety. Although fewer patients are now undergoing TAVR via nontransfemoral access, understanding TA-TAVR learning curves and their relationship with outcomes is important as the field moves toward next-generation devices, such as those to replace the mitral valve, delivered via the left ventricular apex. Copyright © 2016 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

Program finds centrifugal compressor operating point

DOE Office of Scientific and Technical Information (OSTI.GOV)

Campos, M.C.M.M.; Rodrigues, P.S.B.

1990-09-01

This article presents the Scop program, a computational procedure developed using Fortran 77 language to find the operating point of centrifugal compressors starting from performance curves. Characteristics or performance curves traditionally are employed by manufacturers to inform users about turbocompressor behavior. Usually, these curves have polytropic head, H, and corresponding polytropic efficiency, {eta} plus rotation speed, N, and inlet volumetric flowrate, Q, as parameters. Two families of curves can be identified in this figure. One provides head-flow relationships for several speeds and the other refers to isoefficiency curves.

Comparison of anterior segment parameters and axial length measurements performed on a Scheimpflug device with biometry function and a reference optical biometer.

PubMed

Muzyka-Woźniak, Maria; Oleszko, Adam

2018-04-26

To compare measurements of axial length (AL), corneal curvature (K), anterior chamber depth (ACD) and white-to-white (WTW) distance on a new device combining Scheimpflug camera and partial coherence interferometry (Pentacam AXL) with a reference optical biometer (IOL Master 500). To evaluate differences between IOL power calculations based on the two biometers. Ninety-seven eyes of 97 consecutive cataract or refractive lens exchange patients were examined preoperatively on IOL Master 500 and Pentacam AXL units. Comparisons between two devices were performed for AL, K, ACD and WTW. Intraocular lens (IOL) power targeting emmetropia was calculated with SRK/T and Haigis formulas on both devices and compared. There were statistically significant differences between two devices for all measured parameters (P < 0.05), except ACD (P = 0.36). Corneal curvature measured with Pentacam AXL was significantly flatter then with IOL Master. The mean difference in AL was clinically insignificant (0.01 mm; 95% LoA 0.16 mm). Pentacam AXL yielded higher IOL power in 75% of eyes for Haigis formula and in 62% of eyes for SRK/T formula, with a mean difference within ± 0.5 D for 72 and 86% of eyes, respectively. There were statistically significant differences between AL, K and WTW measurements obtained with the compared biometers. Flatter corneal curvature measurements on Pentacam AXL necessitate formulas optimisation for Pentacam AXL.

Master's level education in Jordan: a qualitative study of key motivational factors and perceived impact on practice.

PubMed

Zahran, Zainab

2013-09-01

To explore key motivational factors of Jordanian nurses to undertake a Master's degree and explore perceived impact on practice. In Jordan, there are postgraduate educational programmes offering a Master's degree in clinical nursing for registered nurses. These programmes are intended to prepare nurses to practise at an advanced level as potential clinical nurse specialists. Little is known about the motivation of nurses to undertake such Master's degree preparation programmes and their perceived impact on practice. Using an ethnographic design, narratives from semi-structured interviews with participants (n=37) from five Jordanian hospitals and two public universities were collected and thematically analysed. Four main themes emerged from the data: self development; broadening career opportunities; developing practice; and the perceived impact of Master's level nurses on practice. The majority of Jordanian nurses chose to undertake a Master's degree because of a desire for self and practice development. The majority of participants referred to M-level nurses in terms of knowledge transfer, highlighting their clinical teaching and in-service education activities. M-level nurses were also associated with managerial and supervisory roles in clinical practice. Controversy over the impact of M-level nurses in enhancing patient care is not limited to the Jordanian setting. Future research needs to focus on comparative studies between nurses with M-level qualifications and experienced nurses without either M-level qualifications or specialist courses to establish if there is any significant relationship between practice performance and educational preparation and experience. Evaluation research could be undertaken for the purpose of developing measurable and observable criteria related to educational and skill based outcomes. Copyright © 2012 Elsevier Ltd. All rights reserved.

Reference Centile Curves for Body Fat Percentage, Fat-free Mass, Muscle Mass and Bone Mass Measured by Bioelectrical Impedance in Asian Indian Children and Adolescents.

PubMed

Chiplonkar, Shashi; Kajale, Neha; Ekbote, Veena; Mandlik, Rubina; Parthasarathy, Lavanya; Borade, Ashwin; Patel, Pinal; Patel, Prerna; Khadilkar, Vaman; Khadilkar, Anuradha

2017-12-15

To create gender-specific percentile curves for percent body fat (%BF) by Bio electrical Impedance Analysis (BIA) for screening adiposity and risk of hypertension in Indian children and generate reference curves for percent fat-free mass (%FFM), muscle mass (%LM) and bone mineral content (BMC) by using bioelectrical impedance. Secondary analysis of data from previous multicenter cross-sectional studies. Private schools from five regions of India. A random sample of 3850 healthy school children (2067 boys) (5-17 yr) from private schools in five major Indian cities. Anthropometry, blood pressure (BP) and body composition were measured by bioelectrical impedance. Reference curves were generated by the LMS method. %BF, %FFM, %LM, BMC and BP. Median %BF increased by 6% from 5 to 13 years of age and declined (around 2%) up to 17 years in boys. In girls, %BF increased by 8% from 5 to 14 years and thereafter declined by 3%. Based upon the risk of hypertension, the new cut-offs of 75th and 85th percentile of %BF were proposed for detecting over fatness and excess fatness in children. Median %FFM was 90% at 5 yrs and decreased till 12 years, and then showed a slight increase to 84% at 17 yrs in boys. In girls, it was 86% at 5 yrs and decreased till 15 yrs, and plateaued at 71.8% at 17 yrs. Reference curves for percent body fat for Indian children would be useful to screen children for health risk in clinical set up.

A study on FlexMaster : a Ni-Ti rotary engine driven system for root canal preparation.

PubMed

Alam, M S; Bashar, A K; Begumr, J A; Kinoshita, J I

2006-07-01

In the present study, the effectiveness of recently introduced rotary Nickel Titanium FlexMaster engine driven system was evaluated for cleaning and shaping of root canals in extracted human teeth and compared with that done by the Nickel Titanium Flexofile hand instruments. A total of 40 root canals from 36 extracted mandibular and maxillary teeth with curvature ranging between 20 and 30 degree were divided into two groups, consisting 20 canals in each. FlexMaster instrumentation was done in 20 canals, using crown-down technique and manual filing with Flexofile was done in other 20 canals, using conventional and step-back techniques. 5.25% sodium hypochlorite (NaOCl) solution and 17% ethelene di-amine tetra-acetic acid (EDTA) were used alternatively for irrigation after canal preparation by each instrument size. Time needed for canal preparation of individual canal was recorded. A procedural error such as instrument breakage was also noted. After preparation, all the roots were cut longitudinally by using diamond burs in turbine handpiece and examined under scanning electron microscope. Apical region was quantified for debris and smear layer based on a 5-score numerical evaluation scale. The data established for scoring the debris and smear layer and preparation time of individual canal were analyzed statistically using the Mann-Whitney U test. Completely cleaned root canals were not found with any of the two instruments and none of the instruments maintained the original canal uniformity and regular dentine surface. Because significantly less debris was found in the apical region using the manual filing technique (p< 0.05). Thus the flexmaster system was found to produce less cleaner root canal walls than manual technique. Only one FlexMaster finishing file sized 30 was separated in the apical region during preparation of 30 degree curved canal. The time taken by FlexMaster was significantly better (p< 0.01) than that of hand instruments.

Neural-adaptive control of single-master-multiple-slaves teleoperation for coordinated multiple mobile manipulators with time-varying communication delays and input uncertainties.

PubMed

Li, Zhijun; Su, Chun-Yi

2013-09-01

In this paper, adaptive neural network control is investigated for single-master-multiple-slaves teleoperation in consideration of time delays and input dead-zone uncertainties for multiple mobile manipulators carrying a common object in a cooperative manner. Firstly, concise dynamics of teleoperation systems consisting of a single master robot, multiple coordinated slave robots, and the object are developed in the task space. To handle asymmetric time-varying delays in communication channels and unknown asymmetric input dead zones, the nonlinear dynamics of the teleoperation system are transformed into two subsystems through feedback linearization: local master or slave dynamics including the unknown input dead zones and delayed dynamics for the purpose of synchronization. Then, a model reference neural network control strategy based on linear matrix inequalities (LMI) and adaptive techniques is proposed. The developed control approach ensures that the defined tracking errors converge to zero whereas the coordination internal force errors remain bounded and can be made arbitrarily small. Throughout this paper, stability analysis is performed via explicit Lyapunov techniques under specific LMI conditions. The proposed adaptive neural network control scheme is robust against motion disturbances, parametric uncertainties, time-varying delays, and input dead zones, which is validated by simulation studies.

Automated Circulation Systems in Libraries Serving the Blind and Physically Handicapped: A Reference Guide for Planning.

ERIC Educational Resources Information Center

Wanger, Judith; And Others

Designed to facilitate communications in future automation projects between library and data processing personnel, especially those projects involving the use of automated systems in the service of disabled patrons, this guide identifies and describes a master set of major circulation system requirements and design considerations, and illustrates…

A Framework of Metacognitive Scaffolding in Learning Authoring System through Facebook

ERIC Educational Resources Information Center

Jumaat, Nurul Farhana; Tasir, Zaidatun

2016-01-01

Scaffolding refers to a guidance that helps students during their learning sessions whereby it makes learning easier for them. This study aims to develop a framework of metacognitive scaffolding (MS) to guide students in learning Authoring System through Facebook. Thirty-seven master degree students who were enrolled in Authoring System course…

The GED and the Rise of Contextless Accountability

ERIC Educational Resources Information Center

Hutt, Ethan

2014-01-01

Background/Context:Policy discussions in the U.S. and abroad have become increasingly studded with reference to the results of international tests like PISA. Unlike most assessments, PISA is not designed to measure whether students have mastered a particular school curriculum but rather provide a measure of students' ability to meet future…

Students' Framing of a Reading Annotation Tool in the Context of Research-Based Teaching

ERIC Educational Resources Information Center

Dahl, Jan Erik

2016-01-01

In the studied master's course, students participated both as research objects in a digital annotation experiment and as critical investigators of this technology in their semester projects. The students' role paralleled the researcher's role, opening an opportunity for researcher-student co-learning within what is often referred to as…

Training for QSC: How McDonald's Makes Library Managers.

ERIC Educational Resources Information Center

Aycock, Anthony

2001-01-01

Written by a former McDonald's manager who earned a master's degree in library science, this article describes how "QSC"--quality, services, and cleanliness--can be applied to libraries in the same way it is used by restaurants. Argues that libraries are simply businesses that cater to customers. (Contains 42 references.) (NB)

Serious Gaming at School: Reflections on Students' Performance, Engagement and Motivation

ERIC Educational Resources Information Center

Bottino, Rosa Maria; delle Ricerche, Consiglio Nazionale; Ott, Michela; Tavella, Mauro

2014-01-01

The concept of Serious Gaming refers to the adoption of classical entertainment games for purposes other than entertainment, including learning and instruction. In this paper the authors report on a Serious Gaming field experiment where typical board games (such as battleship, master mind and domino) were employed with the shifted purpose of…

The Proximity Principle: Army Chaplains on the Fighting Line in Doctrine and History

DTIC Science & Technology

2014-12-12

U.S. Army Command and General Staff College in partial fulfillment of the requirements for the degree MASTER OF MILITARY ART AND SCIENCE Art......and do not necessarily represent the views of the U.S. Army Command and General Staff College or any other governmental agency. (References to this

Agricultural Marketing. Instructor's Guide. Volume 12, Number 9. Agdex 810, Catalog Number AG-81-I.

ERIC Educational Resources Information Center

Missouri Univ., Columbia. Instructional Materials Lab.

This instructor's guide contains twenty lessons for teaching a curriculum unit in agricultural marketing. Each lesson includes the following instructional elements: objectives, study questions, references, teaching procedures, transparency masters, exams, and answer keys. The lessons cover the following questions: (1) What is marketing? (2) What…

The M.B.A.: A Schizophrenic Graduate Program?

ERIC Educational Resources Information Center

Rinehart, Shelley M.

2007-01-01

The term "M.B.A." is globally recognized as referring to a Masters of Business Administration Program, a degree historically perceived as a graduate's ticket to employment opportunities, generous salaries and the business savvy that garners respect across industries. Recently, however, the value of an M.B.A. has come under fire from many…

The Influence of Curriculum on Master's Students' Perceived Abilities in Four Domains of Graduateness

ERIC Educational Resources Information Center

Steur, Jessica; Jansen, Ellen; Hofman, Adriaan

2016-01-01

Potentially all university graduates, regardless of the discipline they have studied, are expected to have obtained generic learning outcomes, which we refer to as "graduateness." This study investigates the extent to which learning programmes' emphasis on graduateness affects students' perceived abilities in the domains of graduateness.…

Application of a Master Equation for Quantitative mRNA Analysis Using qRT-PCR

USDA-ARS?s Scientific Manuscript database

The qRT-PCR has been widely accepted as the assay of choice for mRNA quantification. Gene expression as measured by mRNA dynamics varies in response to different conditions and environmental stimuli. For conventional practice, housekeeping genes have been applied as internal reference for data nor...

The NASA master directory: Quick reference guide

NASA Technical Reports Server (NTRS)

Satin, Karen (Editor); Kanga, Carol (Editor)

1989-01-01

This is a quick reference guide to the NASA Master Directory (MD), which is a free, online, multidisciplinary directory of space and Earth science data sets (NASA and non-NASA data) that are of potential interest to the NASA-sponsored research community. The MD contains high-level descriptions of data sets, other data systems and archives, and campaigns and projects. It provides mechanisms for searching for data sets by important criteria such as geophysical parameters, time, and spatial coverage, and provides information on ordering the data. It also provides automatic connections to a number of data systems such as the NASA Climate Data System, the Planetary Data System, the NASA Ocean Data System, the Pilot Land Data System, and others. The MD includes general information about many data systems, data centers, and coordinated data analysis projects, It represents the first major step in the Catalog Interoperability project, whose objective is to enable researchers to quickly and efficiently identify, obtain information about, and get access to space and Earth science data. The guide describes how to access, use, and exit the MD and lists its features.

Description of an 8 MW reference wind turbine

NASA Astrophysics Data System (ADS)

Desmond, Cian; Murphy, Jimmy; Blonk, Lindert; Haans, Wouter

2016-09-01

An 8 MW wind turbine is described in terms of mass distribution, dimensions, power curve, thrust curve, maximum design load and tower configuration. This turbine has been described as part of the EU FP7 project LEANWIND in order to facilitate research into logistics and naval architecture efficiencies for future offshore wind installations. The design of this 8 MW reference wind turbine has been checked and validated by the design consultancy DNV-GL. This turbine description is intended to bridge the gap between the NREL 5 MW and DTU 10 reference turbines and thus contribute to the standardisation of research and development activities in the offshore wind energy industry.

Strategies to assess the validity of recommendations: a study protocol

PubMed Central

2013-01-01

Background Clinical practice guidelines (CPGs) become quickly outdated and require a periodic reassessment of evidence research to maintain their validity. However, there is little research about this topic. Our project will provide evidence for some of the most pressing questions in this field: 1) what is the average time for recommendations to become out of date?; 2) what is the comparative performance of two restricted search strategies to evaluate the need to update recommendations?; and 3) what is the feasibility of a more regular monitoring and updating strategy compared to usual practice?. In this protocol we will focus on questions one and two. Methods The CPG Development Programme of the Spanish Ministry of Health developed 14 CPGs between 2008 and 2009. We will stratify guidelines by topic and by publication year, and include one CPG by strata. We will develop a strategy to assess the validity of CPG recommendations, which includes a baseline survey of clinical experts, an update of the original exhaustive literature searches, the identification of key references (reference that trigger a potential recommendation update), and the assessment of the potential changes in each recommendation. We will run two alternative search strategies to efficiently identify important new evidence: 1) PLUS search based in McMaster Premium LiteratUre Service (PLUS) database; and 2) a Restrictive Search (ReSe) based on the least number of MeSH terms and free text words needed to locate all the references of each original recommendation. We will perform a survival analysis of recommendations using the Kaplan-Meier method and we will use the log-rank test to analyse differences between survival curves according to the topic, the purpose, the strength of recommendations and the turnover. We will retrieve key references from the exhaustive search and evaluate their presence in the PLUS and ReSe search results. Discussion Our project, using a highly structured and transparent methodology, will provide guidance of when recommendations are likely to be at risk of being out of date. We will also assess two novel restrictive search strategies which could reduce the workload without compromising rigour when CPGs developers check for the need of updating. PMID:23967896

Reference values for body composition and associations with blood pressure in Kenyan adults aged ≥50 years old.

PubMed

Bastawrous, Madeleine C; Piernas, Carmen; Bastawrous, Andrew; Oke, Jason; Lasserson, Daniel; Mathenge, Wanjiku; Burton, Matthew J; Jebb, Susan A; Kuper, Hannah

2018-05-15

To develop age- and sex-specific centile reference curves for fat-free mass (FFM) and fat mass (FM) adjusted for height in an adult Kenyan population and to investigate the association between FM, FFM and blood pressure (BP). Measures of body composition from bioimpedance analyses and BP were collected in 1995 participants aged ≥50 years in Nakuru County, Kenya. Reference curves were produced using the LMS method. Multivariable linear regression models were used to test the cross-sectional association between body composition indexes and BP. The age- and sex-specific reference curves for body composition (FMI and FFMI) confirmed that FFMI is lower in both men and women with increasing age. FMI declines with age in women while among men the decline starts after 70 years. FFM was higher in men (47.4 ± 7.2 kg) than in women (38.8 ± 5.5 kg), while FM was lower in men (17.3 ± 8.1 kg) than in women (24.4 ± 10.2 kg). FMI, FFMI and BMI were all positively associated with systolic and diastolic BP, and after adjusting for body weight, FFMI remained positively associated with systolic BP and the FMI remained positively associated with diastolic BP. There was no evidence to suggest that FMI and FFMI were superior to measurement of BMI alone. These body composition reference curves provide normative data on body composition for older adults in Kenya. Further research should consider the prospective associations with health, including frailty-related outcomes.

Establishment of Biological Reference Intervals and Reference Curve for Urea by Exploratory Parametric and Non-Parametric Quantile Regression Models.

PubMed

Sarkar, Rajarshi

2013-07-01

The validity of the entire renal function tests as a diagnostic tool depends substantially on the Biological Reference Interval (BRI) of urea. Establishment of BRI of urea is difficult partly because exclusion criteria for selection of reference data are quite rigid and partly due to the compartmentalization considerations regarding age and sex of the reference individuals. Moreover, construction of Biological Reference Curve (BRC) of urea is imperative to highlight the partitioning requirements. This a priori study examines the data collected by measuring serum urea of 3202 age and sex matched individuals, aged between 1 and 80 years, by a kinetic UV Urease/GLDH method on a Roche Cobas 6000 auto-analyzer. Mann-Whitney U test of the reference data confirmed the partitioning requirement by both age and sex. Further statistical analysis revealed the incompatibility of the data for a proposed parametric model. Hence the data was non-parametrically analysed. BRI was found to be identical for both sexes till the 2(nd) decade, and the BRI for males increased progressively 6(th) decade onwards. Four non-parametric models were postulated for construction of BRC: Gaussian kernel, double kernel, local mean and local constant, of which the last one generated the best-fitting curves. Clinical decision making should become easier and diagnostic implications of renal function tests should become more meaningful if this BRI is followed and the BRC is used as a desktop tool in conjunction with similar data for serum creatinine.

SU-G-BRB-14: Uncertainty of Radiochromic Film Based Relative Dose Measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Devic, S; Tomic, N; DeBlois, F

2016-06-15

Purpose: Due to inherently non-linear dose response, measurement of relative dose distribution with radiochromic film requires measurement of absolute dose using a calibration curve following previously established reference dosimetry protocol. On the other hand, a functional form that converts the inherently non-linear dose response curve of the radiochromic film dosimetry system into linear one has been proposed recently [Devic et al, Med. Phys. 39 4850–4857 (2012)]. However, there is a question what would be the uncertainty of such measured relative dose. Methods: If the relative dose distribution is determined going through the reference dosimetry system (conversion of the response bymore » using calibration curve into absolute dose) the total uncertainty of such determined relative dose will be calculated by summing in quadrature total uncertainties of doses measured at a given and at the reference point. On the other hand, if the relative dose is determined using linearization method, the new response variable is calculated as ζ=a(netOD)n/ln(netOD). In this case, the total uncertainty in relative dose will be calculated by summing in quadrature uncertainties for a new response function (σζ) for a given and the reference point. Results: Except at very low doses, where the measurement uncertainty dominates, the total relative dose uncertainty is less than 1% for the linear response method as compared to almost 2% uncertainty level for the reference dosimetry method. The result is not surprising having in mind that the total uncertainty of the reference dose method is dominated by the fitting uncertainty, which is mitigated in the case of linearization method. Conclusion: Linearization of the radiochromic film dose response provides a convenient and a more precise method for relative dose measurements as it does not require reference dosimetry and creation of calibration curve. However, the linearity of the newly introduced function must be verified. Dave Lewis is inventor and runs a consulting company for radiochromic films.« less

Construction of a New Growth References for China Based on Urban Chinese Children: Comparison with the WHO Growth Standards

PubMed Central

Zong, Xin-Nan; Li, Hui

2013-01-01

Introduction Growth references for Chinese children should be updated due to the positive secular growth trends and the progress of the smoothing techniques. Human growth differs among the various ethnic groups, so comparison of the China references with the WHO standards helps to understand such differences. Methods The China references, including weight, length/height, head circumference, weight-for-length/height and body mass index (BMI) aged 0–18 years, were constructed based on 69,760 urban infants and preschool children under 7 years and 24,542 urban school children aged 6–20 years derived from two cross-sectional national surveys. The Cole’s LMS method is employed for smoothing the growth curves. Results The merged data sets resulted in a smooth transition at age 6–7 years and continuity of curves from 0 to 18 years. Varying differences were found on the empirical standard deviation (SD) curves in each indicator at nearly all ages between China and WHO. The most noticeable differences occurred in genders, final height and boundary centiles curves. Chinese boys’ weight is strikingly heavier than that of the WHO at age 6–10 years. The height is taller than that of the WHO for boys below 15 years and for girls below 13, but is significantly lower when boys over 15 years and girls over 13. BMI is generally higher than that of the WHO for boys at age 6–16 years but appreciably lower for girls at 3–18 years. Conclusions The differences between China and WHO are mainly caused by the reference populations of different ethnic backgrounds. For practitioners, the choices of the standards/references depend on the population to be assessed and the purpose of the study. The new China references could be applied to facilitate the standardization assessment of growth and nutrition for Chinese children and adolescents in clinical pediatric and public health. PMID:23527219

GENIE - Generation of computational geometry-grids for internal-external flow configurations

NASA Technical Reports Server (NTRS)

Soni, B. K.

1988-01-01

Progress realized in the development of a master geometry-grid generation code GENIE is presented. The grid refinement process is enhanced by developing strategies to utilize bezier curves/surfaces and splines along with weighted transfinite interpolation technique and by formulating new forcing function for the elliptic solver based on the minimization of a non-orthogonality functional. A two step grid adaptation procedure is developed by optimally blending adaptive weightings with weighted transfinite interpolation technique. Examples of 2D-3D grids are provided to illustrate the success of these methods.

Study of diffusion coefficient of anhydrous trehalose glasses by using PFG-NMR spectroscopy

NASA Astrophysics Data System (ADS)

Kwon, Hyun-Joung; Takekawa, Reiji; Kawamura, Junichi; Tokuyama, Michio

2013-02-01

We investigated the temperature dependent long time self-diffusion coefficient of the anhydrous trehalose supercooled liquids by using pulsed field gradient nuclear magnetic resonance (PFG-NMR) spectroscopy. At the same temperature ranges, the diffusion coefficient convoluted from the α-relaxation time as Einstein-Smoluchowski relaxation, measured by using the dielectric loss spectroscopy are well overlapped with diffusion coefficients within experimental error. The temperature dependent diffusion coefficients obtained from different methods are normalized by fictive temperature and well satisfied the single master curve, proposed by Tokuyama.

Protecting quantum Fisher information in curved space-time

NASA Astrophysics Data System (ADS)

Huang, Zhiming

2018-03-01

In this work, we investigate the quantum Fisher information (QFI) dynamics of a two-level atom interacting with quantized conformally coupled massless scalar fields in de Sitter-invariant vacuum. We first derive the master equation that governs its evolution. It is found that the QFI decays with evolution time. Furthermore, we propose two schemes to protect QFI by employing prior weak measurement (WM) and post measurement reversal (MR). We find that the first scheme can not always protect QFI and the second scheme has prominent advantage over the first scheme.

Optically induced melting of colloidal crystals and their recrystallization.

PubMed

Harada, Masashi; Ishii, Masahiko; Nakamura, Hiroshi

2007-04-15

Colloidal crystals melt by applying focused light of optical tweezers and recrystallize after removing it. The disturbed zone by the light grows radially from the focus point and the ordering starts from the interface with the crystal. Although the larger disturbed zone is observed for the higher power optical tweezers, a master curve is extracted by normalization of the disturbed zone. The temporal changes of the normalized disturbed zone are well described with exponential functions, indicating that the melting and recrystallization process is governed by a simple relaxation mechanism.

[Body mass index charts of Algerian children and adolescents (6-18 years)].

PubMed

Bahchachi, N; Dahel-Mekhancha, C-C; Rolland-Cachera, M-F; Roelants, M; Hauspie, R; Nezzal, L

2017-12-01

The body mass index (BMI) is widely accepted as a measure of overweight and obesity in children. There are no BMI reference charts for Algerian children and adolescents. The purpose of this study was to construct BMI percentile curves appropriate for children aged 6-18 years in Algeria. The weight and height of 7772 (54.9% girls) healthy schoolchildren from Constantine (eastern Algeria) were measured in 2008/2009. Weight and height for age curves based on the same sample were published previously. The BMI for age percentile curves were estimated in girls and boys separately using the LMS smoothing method. In both sexes, the median BMI increased with age. Girls had lower BMI values than boys before the age of 10 years but they were higher after this age until 18 years of age. Within the study population, the prevalence of overweight (including obesity) and obesity in girls and boys together was 13.7% and 3.0%, respectively, according to the International Obesity Task Force (IOTF) and 16.9% and 4.9% according to the World Health Organization (WHO) (2007). The median BMI curves of Algerian girls and boys were generally lower than those observed in other Arab countries. Compared with other references, the median BMI values of girls were lower than those of a Belgian Flemish population and WHO 2007 until 14 years of age and higher than the French reference between 7 and 18 years of age. The BMI values of Algerian boys were close to the Belgian (Flemish population), French and WHO 2007 references between 6 and 9 years of age and generally lower thereafter. These BMI curves are complementary to the height and weight charts published previously for the assessment of growth in children and adolescents. They were developed according to international guidelines and could serve as a national reference. They could be used as a complement to the 0- to 5-year-old WHO 2006 standards. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Conclusions about differences in linear growth between Bangladeshi boys and girls depend on the growth reference used.

PubMed

Moestue, H; de Pee, S; Hall, A; Hye, A; Sultana, N; Ishtiaque, M Z; Huq, N; Bloem, M W

2004-05-01

To examine sex differences in height-for-age z-scores and the percentage stunting among Bangladeshi children estimated using three growth references. Data collected between 1990 and 1999 by Helen Keller International's nutritional surveillance system in rural Bangladesh were analyzed for 504 358 children aged 6-59 months. Height-for-age z-scores were estimated using the 1977 NCHS, 2000 CDC and 1990 British growth references. The shape of the growth curves for Bangladeshi boys and girls, and their positions relative to one another, depend on which of the three growth references is used. At 6 months of age the British reference showed no sex difference whereas the NCHS and CDC showed girls to have higher average z-scores than boys by 0.14 and 0.28 s.d., respectively. While all references showed a faster deterioration of girls' z-scores from 6 to 24 months, the magnitude and direction of the sex differences, and how they changed with age, were different. There was greater disagreement about girls' z-scores than boys. Discontinuities at 24 months in the NCHS and CDC produced jagged curves whereas the British curves were smooth. The assessment of sex differences in linear growth depends on the growth reference used. Reasons for the different results need to be determined and may aid the final development of the new WHO international growth reference and the guidelines for its use. The findings suggest that anthropometry as a tool to explore the effects of societal gender inequality must be used with caution.

Assessing gross motor development of Brazilian infants.

PubMed

Gontijo, Ana Paula Bensemann; de Castro Magalhães, Lívia; Guerra, Miriam Queiroz Faria

2014-01-01

To determine whether the Alberta Infant Motor Scale (AIMS) requires reference values specific for Brazilian infants. A total of 660 (330 girls) healthy full-term infants from Belo Horizonte were assessed using the AIMS. Scores and percentile curves were compared with the Canadian reference values. Differences were found in the 5th percentile (9-<10 and 10-<11 months) and the 10th percentile (4-<5, 9-<10, and 10-<11 months) curves. No significant differences were found between sexes on the basis of the economic classification or the criteria of the Human Development Index. Primarily because of the corrections made to the 5th and 10th percentile curves, we recommend the use of the Brazilian infant data curves reported here for further studies conducted in Brazil. Because the Human Development Index of Belo Horizonte is similar to that for Brazil as a whole, the results of this study should be relevant for clinicians throughout Brazil.

It's time to move on from the bell curve.

PubMed

Robinson, Lawrence R

2017-11-01

The bell curve was first described in the 18th century by de Moivre and Gauss to depict the distribution of binomial events, such as coin tossing, or repeated measures of physical objects. In the 19th and 20th centuries, the bell curve was appropriated, or perhaps misappropriated, to apply to biologic and social measures across people. For many years we used it to derive reference values for our electrophysiologic studies. There is, however, no reason to believe that electrophysiologic measures should approximate a bell-curve distribution, and empiric evidence suggests they do not. The concept of using mean ± 2 standard deviations should be abandoned. Reference values are best derived by using non-parametric analyses, such as percentile values. This proposal aligns with the recommendation of the recent normative data task force of the American Association of Neuromuscular & Electrodiagnostic Medicine and follows sound statistical principles. Muscle Nerve 56: 859-860, 2017. © 2017 Wiley Periodicals, Inc.

Reference Curves for Field Tests of Musculoskeletal Fitness in U.S. Children and Adolescents: The 2012 NHANES National Youth Fitness Survey.

PubMed

Laurson, Kelly R; Saint-Maurice, Pedro F; Welk, Gregory J; Eisenmann, Joey C

2017-08-01

Laurson, KR, Saint-Maurice, PF, Welk, GJ, and Eisenmann, JC. Reference curves for field tests of musculoskeletal fitness in U.S. children and adolescents: The 2012 NHANES National Youth Fitness Survey. J Strength Cond Res 31(8): 2075-2082, 2017-The purpose of the study was to describe current levels of musculoskeletal fitness (MSF) in U.S. youth by creating nationally representative age-specific and sex-specific growth curves for handgrip strength (including relative and allometrically scaled handgrip), modified pull-ups, and the plank test. Participants in the National Youth Fitness Survey (n = 1,453) were tested on MSF, aerobic capacity (via submaximal treadmill test), and body composition (body mass index [BMI], waist circumference, and skinfolds). Using LMS regression, age-specific and sex-specific smoothed percentile curves of MSF were created and existing percentiles were used to assign age-specific and sex-specific z-scores for aerobic capacity and body composition. Correlation matrices were created to assess the relationships between z-scores on MSF, aerobic capacity, and body composition. At younger ages (3-10 years), boys scored higher than girls for handgrip strength and modified pull-ups, but not for the plank. By ages 13-15, differences between the boys and girls curves were more pronounced, with boys scoring higher on all tests. Correlations between tests of MSF and aerobic capacity were positive and low-to-moderate in strength. Correlations between tests of MSF and body composition were negative, excluding absolute handgrip strength, which was inversely related to other MSF tests and aerobic capacity but positively associated with body composition. The growth curves herein can be used as normative reference values or a starting point for creating health-related criterion reference standards for these tests. Comparisons with prior national surveys of physical fitness indicate that some components of MSF have likely decreased in the United States over time.

Observable Zitterbewegung in curved spacetimes

NASA Astrophysics Data System (ADS)

Kobakhidze, Archil; Manning, Adrian; Tureanu, Anca

2016-06-01

Zitterbewegung, as it was originally described by Schrödinger, is an unphysical, non-observable effect. We verify whether the effect can be observed in non-inertial reference frames/curved spacetimes, where the ambiguity in defining particle states results in a mixing of positive and negative frequency modes. We explicitly demonstrate that such a mixing is in fact necessary to obtain the correct classical value for a particle's velocity in a uniformly accelerated reference frame, whereas in cosmological spacetime a particle does indeed exhibit Zitterbewegung.

Native Silk Feedstock as a Model Biopolymer: A Rheological Perspective.

PubMed

Laity, Peter R; Holland, Chris

2016-08-08

Variability in silk's rheology is often regarded as an impediment to understanding or successfully copying the natural spinning process. We have previously reported such variability in unspun native silk extracted straight from the gland of the domesticated silkworm Bombyx mori and discounted classical explanations such as differences in molecular weight and concentration. We now report that variability in oscillatory measurements can be reduced onto a simple master-curve through normalizing with respect to the crossover. This remarkable result suggests that differences between silk feedstocks are rheologically simple and not as complex as originally thought. By comparison, solutions of poly(ethylene-oxide) and hydroxypropyl-methyl-cellulose showed similar normalization behavior; however, the resulting curves were broader than for silk, suggesting greater polydispersity in the (semi)synthetic materials. Thus, we conclude Nature may in fact produce polymer feedstocks that are more consistent than typical man-made counterparts as a model for future rheological investigations.

Science and Facebook: The same popularity law!

PubMed

Néda, Zoltán; Varga, Levente; Biró, Tamás S

2017-01-01

The distribution of scientific citations for publications selected with different rules (author, topic, institution, country, journal, etc…) collapse on a single curve if one plots the citations relative to their mean value. We find that the distribution of "shares" for the Facebook posts rescale in the same manner to the very same curve with scientific citations. This finding suggests that citations are subjected to the same growth mechanism with Facebook popularity measures, being influenced by a statistically similar social environment and selection mechanism. In a simple master-equation approach the exponential growth of the number of publications and a preferential selection mechanism leads to a Tsallis-Pareto distribution offering an excellent description for the observed statistics. Based on our model and on the data derived from PubMed we predict that according to the present trend the average citations per scientific publications exponentially relaxes to about 4.

Science and Facebook: The same popularity law!

PubMed Central

Varga, Levente; Biró, Tamás S.

2017-01-01

The distribution of scientific citations for publications selected with different rules (author, topic, institution, country, journal, etc…) collapse on a single curve if one plots the citations relative to their mean value. We find that the distribution of “shares” for the Facebook posts rescale in the same manner to the very same curve with scientific citations. This finding suggests that citations are subjected to the same growth mechanism with Facebook popularity measures, being influenced by a statistically similar social environment and selection mechanism. In a simple master-equation approach the exponential growth of the number of publications and a preferential selection mechanism leads to a Tsallis-Pareto distribution offering an excellent description for the observed statistics. Based on our model and on the data derived from PubMed we predict that according to the present trend the average citations per scientific publications exponentially relaxes to about 4. PMID:28678796

Effect of various features on the life cycle cost of the timing/synchronization subsystem of the DCS digital communications network

NASA Technical Reports Server (NTRS)

Kimsey, D. B.

1978-01-01

The effect on the life cycle cost of the timing subsystem was examined, when these optional features were included in various combinations. The features included mutual control, directed control, double-ended reference links, independence of clock error measurement and correction, phase reference combining, self-organization, smoothing for link and nodal dropouts, unequal reference weightings, and a master in a mutual control network. An overall design of a microprocessor-based timing subsystem was formulated. The microprocessor (8080) implements the digital filter portion of a digital phase locked loop, as well as other control functions such as organization of the network through communication with processors at neighboring nodes.

Guidelines for application of learning/cost improvement curves

NASA Technical Reports Server (NTRS)

Delionback, L. M.

1975-01-01

The differences between the terms learning curve and improvement curve are noted, as well as the differences between the Wright system and the Crawford system. Learning curve computational techniques were reviewed along with a method to arrive at a composite learning curve for a system given detail curves either by the functional techniques classification or simply categorized by subsystem. Techniques are discussed for determination of the theoretical first unit (TFU) cost using several of the currently accepted methods. Sometimes TFU cost is referred to as simply number one cost. A tabular presentation of the various learning curve slope values is given. A discussion of the various trends in the application of learning/improvement curves and an outlook for the future are presented.

Combing VFH with bezier for motion planning of an autonomous vehicle

NASA Astrophysics Data System (ADS)

Ye, Feng; Yang, Jing; Ma, Chao; Rong, Haijun

2017-08-01

Vector Field Histogram (VFH) is a method for mobile robot obstacle avoidance. However, due to the nonholonomic constraints of the vehicle, the algorithm is seldom applied to autonomous vehicles. Especially when we expect the vehicle to reach target location in a certain direction, the algorithm is often unsatisfactory. Fortunately, the Bezier Curve is defined by the states of the starting point and the target point. We can use this feature to make the vehicle in the expected direction. Therefore, we propose an algorithm to combine the Bezier Curve with the VFH algorithm, to search for the collision-free states with the VFH search method, and to select the optimal trajectory point with the Bezier Curve as the reference line. This means that we will improve the cost function in the VFH algorithm by comparing the distance between candidate directions and reference line. Finally, select the closest direction to the reference line to be the optimal motion direction.

Comparison of implant cast accuracy of multiple implant impression technique with different splinting materials: An in vitro study

PubMed Central

Selvaraj, Sunantha; Dorairaj, Jayachandran; Mohan, Jayashree; Simon, Paul

2016-01-01

Introduction: An accurate and passive fit of implant framework prosthesis, as well as the successful surgical operation is suggested as one of the critical requirements for long-term implant success. Objective: The purpose of this in vitro study was to evaluate the accuracy of the master cast using open tray impression technique with conventional and novel splinting materials. Methodology: A mandibular reference model with four ADIN implants was done. Ten custom trays were fabricated using the light curable resin sheets. Medium body polyether impression material was used. These trays were randomly divided between the two groups, with five trays in each group. Impression techniques were divided into two groups namely: Group A: Direct impression technique with open tray impression copings splinted with autopolymerizing acrylic resin (GC pattern resin). Group B: Direct impression technique with open tray impression copings splinted with Pro-temp TM 4 (bis-GMA) syringable temporization material. Thus, final impressions were made. Total of 10 master casts were fabricated. Evaluation of casts using Dynascope-Vision Engineering, TESA microhite two- dimension and coordinate measuring machine were used. Results: Statistical comparisons were made using ANOVA test and post-hoc test. Same amount of deviation values obtained with resin splinted and bis-GMA splinted impression copings. Conclusion: The master cast obtained by both the splinting material exhibits no difference from the reference model. So bis-GMA can be used, which is easy to handle, less time consuming, less technique sensitive, rigid, and readily available material in clinics. PMID:27141167

To authorize the National Science Foundation to award grants for implementing or expanding research-based reforms in master's and doctoral level STEM education that emphasize preparation for diverse careers in the STEM workforce.

THOMAS, 111th Congress

Rep. Giffords, Gabrielle [D-AZ-8

2010-03-25

House - 04/30/2010 Referred to the Subcommittee on Higher Education, Lifelong Learning, and Competitiveness. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Completed Research in Health, Physical Education, Recreation & Dance, Including International Sources. Volume 32-1990 Edition.

ERIC Educational Resources Information Center

Chamberlin, Craig, Ed.

This compilation provides 256 abstracts of research completed in the areas of health, physical education, recreation, dance, and allied areas during 1989. Master's theses and doctoral dissertations are abstracted from institutions offering graduate programs in those fields. The volume includes an index to the abstracts in which references are…

Completed Research in Health, Physical Education, Recreation & Dance; Including International Sources. Volume 27. 1985 Edition.

ERIC Educational Resources Information Center

Freedson, Patty S., Ed.

This compilation lists research completed in the areas of health, physical education, recreation, dance, and allied areas during 1984. The document is arranged in two parts. In the index, references are arranged under the subject headings in alphabetical order. Abstracts of master's and doctor's theses from institutions offering graduate programs…

45 CFR 162.1403 - Operating rules for health care claim status transaction.

Code of Federal Regulations, 2011 CFR

2011-10-01

... the following: (a) Except as specified in paragraph (b) of this section, the following CAQH CORE Phase... II CORE 250: Claim Status Rule, version 2.1.0, March 2011, and CORE v5010 Master Companion Guide, 00510, 1.2, March 2011. (Incorporated by reference in § 162.920). (2) Phase II CORE 270: Connectivity...

From Vocational Decision Making to Career Building: Blueprint, Real Games, and School Counseling.

ERIC Educational Resources Information Center

Jarvis, Phillip S.; Keeley, Ethel S.

2003-01-01

Presents ways to help students make more informed career choices and gain employability and self-management skills under a suggested career development rubric. Focuses on the importance of considering a framework for school counselors to help students become aware of and master career management skills. (Contains 21 references and 2 tables.) (GCP)

An Integrated Non-Mechanized System for Information Bulletins and a Keyword Index

ERIC Educational Resources Information Center

Whitehall, T.

1972-01-01

Described is an operating system for scanning, bulletin production and indexing which is very economical in the use of time. One typing onto offset masters is used to produce bulletins, slips for customers' personal files and for the library index. Indexing is done during scanning, not as a separate activity. (3 references) (Author/SJ)

Report on Student Academic Integrity and Allegations of Contract Cheating by University Students

ERIC Educational Resources Information Center

Australian Government Tertiary Education Quality and Standards Agency, 2015

2015-01-01

On 12 November 2014 the Fairfax media reported allegations of cheating by students at a number of Australian higher education providers through the purchase of assignments, particularly through the MyMaster website. The Honorable Christopher Pyne MP, Minister for Education and Training, referred the matter to the Tertiary Education Quality and…

26. SPILLWAY DISCHARGE DATA. CURVE NO. 3 AND NO. 4. ...

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

26. SPILLWAY DISCHARGE DATA. CURVE NO. 3 AND NO. 4. April 1928 Reference No. 108.2 - Cushman No. 1 Hydroelectric Power Plant, Spillway, North Fork of Skokomish River, 5 miles West of Hood Canal, Hoodsport, Mason County, WA

25. SPILLWAY DISCHARGE DATA. CURVE NO. 1 AND NO. 2. ...

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

25. SPILLWAY DISCHARGE DATA. CURVE NO. 1 AND NO. 2. April 1928 Reference No. BT-108.1 - Cushman No. 1 Hydroelectric Power Plant, Spillway, North Fork of Skokomish River, 5 miles West of Hood Canal, Hoodsport, Mason County, WA

Anthropomorphic Telemanipulation System in Terminus Control Mode

NASA Technical Reports Server (NTRS)

Jau, Bruno M.; Lewis, M. Anthony; Bejczy, Antal K.

1994-01-01

This paper describes a prototype anthropomorphic kinesthetic telepresence system that is being developed at JPL. It utilizes dexterous terminus devices in the form of an exoskeleton force-sensing master glove worn by the operator and a replica four finger anthropomorphic slave hand. The newly developed master glove is integrated with our previously developed non-anthropomorphic six degree of freedom (DOF) universal force-reflecting hand controller (FRHC). The mechanical hand and forearm are mounted to an industrial robot (PUMA 560), replacing its standard forearm. The notion of 'terminus control mode' refers to the fact that only the terminus devices (glove and robot hand) are of anthropomorphic nature, and the master and slave arms are non-anthropomorphic. The system is currently being evaluated, focusing on tool handling and astronaut equivalent task executions. The evaluation revealed the system's potential for tool handling but it also became evident that hand tool manipulations and space operations require a dual arm robot. This paper describes the system's principal components, its control and computing architecture, discusses findings of the tool handling evaluation, and explains why common tool handling and EVA space tasks require dual arm robots.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Field, Scott E.; Hesthaven, Jan S.; Lau, Stephen R.

In the context of metric perturbation theory for nonspinning black holes, extreme mass ratio binary systems are described by distributionally forced master wave equations. Numerical solution of a master wave equation as an initial boundary value problem requires initial data. However, because the correct initial data for generic-orbit systems is unknown, specification of trivial initial data is a common choice, despite being inconsistent and resulting in a solution which is initially discontinuous in time. As is well known, this choice leads to a burst of junk radiation which eventually propagates off the computational domain. We observe another potential consequence ofmore » trivial initial data: development of a persistent spurious solution, here referred to as the Jost junk solution, which contaminates the physical solution for long times. This work studies the influence of both types of junk on metric perturbations, waveforms, and self-force measurements, and it demonstrates that smooth modified source terms mollify the Jost solution and reduce junk radiation. Our concluding section discusses the applicability of these observations to other numerical schemes and techniques used to solve distributionally forced master wave equations.« less

Method and Excel VBA Algorithm for Modeling Master Recession Curve Using Trigonometry Approach.

PubMed

Posavec, Kristijan; Giacopetti, Marco; Materazzi, Marco; Birk, Steffen

2017-11-01

A new method was developed and implemented into an Excel Visual Basic for Applications (VBAs) algorithm utilizing trigonometry laws in an innovative way to overlap recession segments of time series and create master recession curves (MRCs). Based on a trigonometry approach, the algorithm horizontally translates succeeding recession segments of time series, placing their vertex, that is, the highest recorded value of each recession segment, directly onto the appropriate connection line defined by measurement points of a preceding recession segment. The new method and algorithm continues the development of methods and algorithms for the generation of MRC, where the first published method was based on a multiple linear/nonlinear regression model approach (Posavec et al. 2006). The newly developed trigonometry-based method was tested on real case study examples and compared with the previously published multiple linear/nonlinear regression model-based method. The results show that in some cases, that is, for some time series, the trigonometry-based method creates narrower overlaps of the recession segments, resulting in higher coefficients of determination R 2 , while in other cases the multiple linear/nonlinear regression model-based method remains superior. The Excel VBA algorithm for modeling MRC using the trigonometry approach is implemented into a spreadsheet tool (MRCTools v3.0 written by and available from Kristijan Posavec, Zagreb, Croatia) containing the previously published VBA algorithms for MRC generation and separation. All algorithms within the MRCTools v3.0 are open access and available free of charge, supporting the idea of running science on available, open, and free of charge software. © 2017, National Ground Water Association.

Molecular dynamics study of thermodynamic scaling of the glass-transition dynamics in ionic liquids over wide temperature and pressure ranges.

PubMed

Habasaki, J; Casalini, R; Ngai, K L

2010-03-25

Experimentally, superpositioning of dynamic properties such as viscosity, relaxation times, or diffusion coefficients under different conditions of temperature T, pressure P, and volume V by the scaling variable TV(gamma) (where gamma is a material constant) has been reported as a general feature of many kinds of glass-forming materials. In the present work, molecular dynamics (MD) simulations have been performed to study the scaling of dynamics near the glass-transition regime of ionic liquids. Scaling in the simulated 1-ethyl-3-methylimidazolium nitrate (EMIM-NO(3)) system has been tested over wide ranges of temperatures and pressures. TV(gamma) scaling of the dynamics is well described by master curves with gamma = 4.0 +/- 0.2 and 3.8 +/- 0.2 for cation and anion, respectively. Structures and Coulombic terms of the corresponding states are found to be quite similar. The temperature and pressure dependence of the pair correlation function show similar trends and therefore can be superpositioned onto the master curve. Although the behaviors with gamma = 4 might be expected from the relation, gamma = n/3, for the dynamics with the soft-core-type potential U = epsilon(sigma/r)(n), with n = 12, pair potentials used in the MD simulation have a more complex form, and not all the repulsive terms can play their roles in the heterogeneous structures determined by ion-ion interactions. Scaling is related to the common part of effective potentials related to the pair correlation functions, including the many-body effect in real space.

A computer program for predicting recharge with a master recession curve

USGS Publications Warehouse

Heppner, Christopher S.; Nimmo, John R.

2005-01-01

Water-table fluctuations occur in unconfined aquifers owing to ground-water recharge following precipitation and infiltration, and ground-water discharge to streams between storm events. Ground-water recharge can be estimated from well hydrograph data using the water-table fluctuation (WTF) principle, which states that recharge is equal to the product of the water-table rise and the specific yield of the subsurface porous medium. The water-table rise, however, must be expressed relative to the water level that would have occurred in the absence of recharge. This requires a means for estimating the recession pattern of the water-table at the site. For a given site there is often a characteristic relation between the water-table elevation and the water-table decline rate following a recharge event. A computer program was written which extracts the relation between decline rate and water-table elevation from well hydrograph data and uses it to construct a master recession curve (MRC). The MRC is a characteristic water-table recession hydrograph, representing the average behavior for a declining water-table at that site. The program then calculates recharge using the WTF method by comparing the measured well hydrograph with the hydrograph predicted by the MRC and multiplying the difference at each time step by the specific yield. This approach can be used to estimate recharge in a continuous fashion from long-term well records. Presented here is a description of the code including the WTF theory and instructions for running it to estimate recharge with continuous well hydrograph data.

The fundamentals of adaptive grid movement

NASA Technical Reports Server (NTRS)

Eiseman, Peter R.

1990-01-01

Basic grid point movement schemes are studied. The schemes are referred to as adaptive grids. Weight functions and equidistribution in one dimension are treated. The specification of coefficients in the linear weight, attraction to a given grid or a curve, and evolutionary forces are considered. Curve by curve and finite volume methods are described. The temporal coupling of partial differential equations solvers and grid generators was discussed.

Motion of a Point Mass in a Rotating Disc: A Quantitative Analysis of the Coriolis and Centrifugal Force

NASA Astrophysics Data System (ADS)

Haddout, Soufiane

2016-06-01

In Newtonian mechanics, the non-inertial reference frames is a generalization of Newton's laws to any reference frames. While this approach simplifies some problems, there is often little physical insight into the motion, in particular into the effects of the Coriolis force. The fictitious Coriolis force can be used by anyone in that frame of reference to explain why objects follow curved paths. In this paper, a mathematical solution based on differential equations in non-inertial reference is used to study different types of motion in rotating system. In addition, the experimental data measured on a turntable device, using a video camera in a mechanics laboratory was conducted to compare with mathematical solution in case of parabolically curved, solving non-linear least-squares problems, based on Levenberg-Marquardt's and Gauss-Newton algorithms.

Flying over uneven moving terrain based on optic-flow cues without any need for reference frames or accelerometers.

PubMed

Expert, Fabien; Ruffier, Franck

2015-02-26

Two bio-inspired guidance principles involving no reference frame are presented here and were implemented in a rotorcraft, which was equipped with panoramic optic flow (OF) sensors but (as in flying insects) no accelerometer. To test these two guidance principles, we built a tethered tandem rotorcraft called BeeRotor (80 grams), which was tested flying along a high-roofed tunnel. The aerial robot adjusts its pitch and hence its speed, hugs the ground and lands safely without any need for an inertial reference frame. The rotorcraft's altitude and forward speed are adjusted via two OF regulators piloting the lift and the pitch angle on the basis of the common-mode and differential rotor speeds, respectively. The robot equipped with two wide-field OF sensors was tested in order to assess the performances of the following two systems of guidance involving no inertial reference frame: (i) a system with a fixed eye orientation based on the curved artificial compound eye (CurvACE) sensor, and (ii) an active system of reorientation based on a quasi-panoramic eye which constantly realigns its gaze, keeping it parallel to the nearest surface followed. Safe automatic terrain following and landing were obtained with CurvACE under dim light to daylight conditions and the active eye-reorientation system over rugged, changing terrain, without any need for an inertial reference frame.

Least Squares Solution of Small Sample Multiple-Master PSInSAR System

NASA Astrophysics Data System (ADS)

Zhang, Lei; Ding, Xiao Li; Lu, Zhong

2010-03-01

In this paper we propose a least squares based approach for multi-temporal SAR interferometry that allows to estimate the deformation rate with no need of phase unwrapping. The approach utilizes a series of multi-master wrapped differential interferograms with short baselines and only focuses on the arcs constructed by two nearby points at which there are no phase ambiguities. During the estimation an outlier detector is used to identify and remove the arcs with phase ambiguities, and pseudoinverse of priori variance component matrix is taken as the weight of correlated observations in the model. The parameters at points can be obtained by an indirect adjustment model with constraints when several reference points are available. The proposed approach is verified by a set of simulated data.

Extraction and Analysis of Traditional Chinese Medicine Crops Based on Multitemporal High Resolution Data-Taking Qiaocheng District of Bozhou as AN Example

NASA Astrophysics Data System (ADS)

Yu, H.; He, J.; Zhou, H.; Guan, F.; Li, L.; Ren, B.; Wang, Z.

2018-04-01

Remote sensing technology has become an important method to rapidly acquireing of planting layout and composition of regional crops.It is very important to accurately master the planting area of Chinese medicine crops in the Characteristic planting area because it relations to accurately master the cultivation of Chinese medicine crops, formulate related policies and adjustment of crop planting structure.The author puts forward a method of using remote sencing technology for momitoring Chinese medicine which has good applicability and generalization. This paper took Qiaocheng District of Bozhou as an example to Verify the feasibility of the method, providing a reference for solving the problem of interpretation and extraction of Chinese medicinal materials in the region.

Site index curves for young-growth California white fir on the western slopes of the Sierra Nevada

Treesearch

K. Leroy Dolph

1987-01-01

Site index curves for young-growth California white fir were developed by using stem analysis data from 77 dominant and codominant trees growing in mixed-coniferstands on the western slopes of the Sierra Nevada. Site index reference age is 50 years at breast height. A family of 11 curves is presented for site index estimation. For more precise estimates, the site index...

Teacher Retention and Satisfaction: A Comparison of M.A.T. and B.S./B.A. Graduates in Teacher Education.

ERIC Educational Resources Information Center

Matthes, William A.; Duffy, William E.

1989-01-01

Reports on characteristics, career patterns, and career satisfaction of 269 teacher education graduates, 1966-1976, who completed either a bachelors degree or an M.A. in teaching. Finds that career satisfaction was related to degree program completed (masters vs. bachelors) and to school locale (rural vs. suburban). Contains 19 references. (SV)

Writing: The Research Paper. Postsecondary Intervention Model for Learning Disabilities. Study Manual #3.

ERIC Educational Resources Information Center

Friedman, Brenda G.; And Others

The manual is intended to help students with language learning disabilities master the academic task of research paper writing. A seven-step procedure is advocated for students and their tutors: (1) select a workable topic, then limit and focus it; (2) use library references to identify sources from which to prepare a working bibliography; (3)…

Postgraduate Educational Research on Violence, Gender, and HIV/AIDS in and around Schools (1995-2004)

ERIC Educational Resources Information Center

Moletsane, R.; Madiya, N.

2011-01-01

Social issues such as HIV/AIDS, bullying, and violence have recently come to the fore in schooling and related research in South Africa. This article describes and critically analyses Masters and Ph.D. research done in education in the period 1995-2004, with particular reference to the voice given to social issues, namely: gender, violence, and…

Communicative Approach: An Alternative Method Used in Improving Students' Academic Reading Achievement

ERIC Educational Resources Information Center

Irmawati, Noer Doddy

2012-01-01

Academic reading is a difficult subject to be mastered. It is needed because most of books or references are written in English. The emphasis is on academic reading which becomes a compulsory subject that must be taught and understood in Faculty of Letters UAD Yogyakarta. Communicative approach is used and applied as an alternative method in the…

A Voyage of Discovery or a Fast Track to Success: Men, Women and the MBA.

ERIC Educational Resources Information Center

Simpson, Ruth

2000-01-01

Results of a study of the personal and career benefits of a Masters of Business Administration suggest that women (n=91) value the experience and appreciate the intrinsic benefits such as enhanced confidence and self-worth. Men (n=120) value the extrinsic benefits such as increased pay and status. (Contains 52 references.) (JOW)

South Asian Students' Needs for Cantonese and Written Chinese in Hong Kong: A Linguistic Study

ERIC Educational Resources Information Center

Li, David C. S.; Chuk, Joanne Y. P.

2015-01-01

Based on qualitative data obtained from 15 South Asian (SA) B.Ed. (EL) (Bachelor of Education in English Language) students, this study reports on SA students' difficulty in mastering Mandarin-based written Chinese and the vernacular Cantonese in Hong Kong. For convenience, SA here also refers to students whose homeland is the Philippines. Since…

Mammals of the Savannah River Site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cothran, E.G.; Smith, M.H.; Wolff, J.O.

1991-12-31

This book is designed to be used as a field guide, reference book, bibliography, and introduction to the basic biology and ecology of the 54 mammal species that currently or potentially exist on or near the Savannah River Site (SRS). For 50 of these species, we present basic descriptions, distinguishing morphological features, distribution and habitat preferences, food habits, reproductive biology, social behavior, ecological relationships with other species, and economic importance to man. For those species that have been studied on the SRS, we summarize the results of these studies. Keys and illustrations are provided for whole body and skull identification.more » A selected glossary defines technical terminology. Illustrations of tracks of the more common larger mammals will assist in field identifications. We also summarize the results of two major long-term SRS studies, ``The Forbearer Census`` and ``White-tailed Deer Studies``. A cross-indexed list of over 300 SRS publications on mammals classifies each publication by 23 categories such as habitat, reproduction, genetics, etc., and also for each mammal species. The 149 Master`s theses and Ph.D. dissertations that have been conducted at the Savannah River Ecology Laboratory are provided as additional references.« less

Mindfulness Based Stress Reduction for Academic Evaluation Anxiety: A Naturalistic Longitudinal Study.

PubMed

Dundas, Ingrid; Thorsheim, Torbjørn; Hjeltnes, Aslak; Binder, Per Einar

2016-04-02

Mindfulness based stress reduction (MBSR) for academic evaluation anxiety and self-confidence in 70 help-seeking bachelor's and master's students was examined. A repeated measures analysis of covariance on the 46 students who completed pretreatment and posttreatment measures (median age = 24 years, 83% women) showed that evaluation anxiety and self-confidence improved. A growth curve analysis with all 70 original participants showed reductions in both cognitive and emotional components of evaluation anxiety, and that reduction continued postintervention. Although more research is needed, this study indicates that MBSR may reduce evaluation anxiety.

Target-based coherent beam combining of an optical phased array fed by a broadband laser source

NASA Astrophysics Data System (ADS)

Hyde, Milo W., IV; McCrae, Jack E.; Tyler, Glenn A.

2017-11-01

The target-based phasing of an optical phased array (OPA) fed by a broadband master oscillator laser source is investigated. The specific scenario examined here considers an OPA phasing through atmospheric turbulence on a rough curved object. An analytical expression for the detected or received intensity is derived. Gleaned from this expression are the conditions under which target-based phasing is possible. A detailed OPA wave optics simulation is performed to validate the theoretical findings. Key aspects of the simulation set-up as well as the results are thoroughly discussed.

Yield stress and scaling of polyelectrolyte multilayer modified suspensions: effect of polyelectrolyte conformation during multilayer assembly.

PubMed

Hess, Andreas; Aksel, Nuri

2013-09-10

The yield stress of polyelectrolyte multilayer modified suspensions exhibits a surprising dependence on the polyelectrolyte conformation of multilayer films. The rheological data scale onto a universal master curve for each polyelectrolyte conformation as the particle volume fraction, φ, and the ionic strength of the background fluid, I, are varied. It is shown that rough films with highly coiled, brushy polyelectrolytes significantly enhance the yield stress. Moreover, via the ionic strength I of the background fluid, the dynamic yield stress of brushy polyelectrolyte multilayers can be finely adjusted over 2 decades.

Velocity and structural model of the Lower Tagus Basin according to the study of environmental seismic noise

NASA Astrophysics Data System (ADS)

Gomes Torres, Ricardo Jorge; Furtado, José Augusto; Gonçalves Silva, Hugo; Borges, José Fernando; Caldeira, Bento; Bezzeghoud, Mourad; Carvalho, João

2013-04-01

Along his history the Lower Tagus Valley (LTV) region was shaken by several earthquakes, some of them produced in large ruptures of offshore structures located southwest of the Portuguese coastline. Among these is the Lisbon earthquake of 1 November 1755 (M~8.5-8.7), and other moderates earthquakes that were produced by local sources such as the 1344 (M6.0), 1531 (M7.1) and 1909 (M6.0) earthquakes. Previous simulations [1] have shown high velocity amplification in the region. The model used in the simulations was updated from low to high resolution using all the new available geophysical and geotechnical data on the area (seismic reflection, aeromagnetic, gravimetric, deep wells and geological outcrops) [2]. To confirm this model in the areas where it was derived by potential field methods we use broadband ambient noise measurements collected in about 200 points along seven profiles on the LTV basin, six perpendicular and one parallel to the basin axis. We applied the horizontal to vertical (H/V) spectral ratio method [3] to the seismic noise profiles in order to estimate the distribution of amplification in the basin. The H/V curves obtained reveals the existence of two low frequency peaks centered on 0.2 and 1 Hz [4]. These peaks are strongly related with the thickness of Cenozoic and alluvial sediments. The velocity model obtained by inversion of the H/V curves is in good agreement with borehole data, and results obtained using seismic reflection and gravimetric methods. However, aeromagnetic data overestimates the depth of the base of Cenozoic in the areas where it overlies directly the paleozoic basement, which we attribute either to the existence of Mesozoic units or higher magnetic susceptibilities than expected for the Paleozoic. References: [1] Bezzeghoud, M., Borges, J.F., M., Caldeira (2011). Ground motion simulations of the SW Iberia margin: rupture directivity and earth structure effects. Natural Hazards, pages 1-17. doi:10.1007/s11069-011-9925-2 [2] Torres, R.J.G., (2012). Modelo de velocidade da Bacia do Vale do Tejo: uma abordagem baseada no estudo do ruído sísmico ambiental, Master Thesis, Universidade de Évora, 83pp. [3] Nakamura, Y., 1989. A method for dynamic characteristics estimations of subsurface using microtremors on the ground surface, Quarterly Report, RTRI, Japan, v. 30, p. 25-33. [4] J.A. Furtado, Confirmação do modelo da estrutura 3D do Vale Inverior do Tejo a partir de dados de ruído sísmico ambiente, Master Thesis, Universidade de Évora, 136pp, 2010.

Deriving the reference value from the circadian motor active patterns in the "non-dementia" population, compared to the "dementia" population: What is the amount of physical activity conducive to the good circadian rhythm.

PubMed

Kodama, Ayuto; Kume, Yu; Tsugaruya, Megumi; Ishikawa, Takashi

2016-01-01

The circadian rhythm in older adults is commonly known to change with a decrease in physical activity. However, the association between circadian rhythm metrics and physical activity remains unclear. The objective of this study was to examine circadian activity patterns in older people with and without dementia and to determine the amount of physical activity conducive to a good circadian measurement. Circadian parameters were collected from 117 older community-dwelling people (66 subjects without dementia and 52 subjects with dementia); the parameters were measured continuously using actigraphy for 7 days. A receiver operating characteristic (ROC) curve was applied to determine reference values for the circadian rhythm parameters, consisting of interdaily stability (IS), intradaily variability (IV), and relative amplitude (RA), in older subjects. The ROC curve revealed reference values of 0.55 for IS, 1.10 for IV, and 0.82 for RA. In addition, as a result of the ROC curve in the moderate-to-vigorous physical Activity (MVPA) conducive to the reference value of the Non-parametric Circadian Rhythm Analysis per day, the optimal reference values were 51 minutes for IV and 55 minutes for RA. However, the IS had no classification accuracy. Our results demonstrated the reference values derived from the circadian parameters of older Japanese population with or without dementia. Also, we determined the MVPA conducive to a good circadian rest-active pattern. This reference value for physical activity conducive to a good circadian rhythm might be useful for developing a new index for health promotion in the older community-dwelling population.

Exploiting Orbital Data and Observation Campaigns to Improve Space Debris Models

NASA Astrophysics Data System (ADS)

Braun, V.; Horstmann, A.; Reihs, B.; Lemmens, S.; Merz, K.; Krag, H.

The European Space Agency (ESA) has been developing the Meteoroid and Space Debris Terrestrial Environment Reference (MASTER) software as the European reference model for space debris for more than 25 years. It is an event-based simulation of all known individual debris-generating events since 1957, including breakups, solid rocket motor firings and nuclear reactor core ejections. In 2014, the upgraded Debris Risk Assessment and Mitigation Analysis (DRAMA) tool suite was released. In the same year an ESA instruction made the standard ISO 24113:2011 on space debris mitigation requirements, adopted via the European Cooperation for Space Standardization (ECSS), applicable to all ESA missions. In order to verify the compliance of a space mission with those requirements, the DRAMA software is used to assess collision avoidance statistics, estimate the remaining orbital lifetime and evaluate the on-ground risk for controlled and uncontrolled reentries. In this paper, the approach to validate the MASTER and DRAMA tools is outlined. For objects larger than 1 cm, thus potentially being observable from ground, the MASTER model has been validated through dedicated observation campaigns. Recent campaign results shall be discussed. Moreover, catalogue data from the Space Surveillance Network (SSN) has been used to correlate the larger objects. In DRAMA, the assessment of collision avoidance statistics is based on orbit uncertainty information derived from Conjunction Data Messages (CDM) provided by the Joint Space Operations Center (JSpOC). They were collected for more than 20 ESA spacecraft in the recent years. The way this information is going to be used in a future DRAMA version is outlined and the comparison of estimated manoeuvre rates with real manoeuvres from the operations of ESA spacecraft is shown.

Spatial resolution measurements by Radia diagnostic software with SEDENTEXCT image quality phantom in cone beam CT for dental use.

PubMed

Watanabe, Hiroshi; Nomura, Yoshikazu; Kuribayashi, Ami; Kurabayashi, Tohru

2018-02-01

We aimed to employ the Radia diagnostic software with the safety and efficacy of a new emerging dental X-ray modality (SEDENTEXCT) image quality (IQ) phantom in CT, and to evaluate its validity. The SEDENTEXCT IQ phantom and Radia diagnostic software were employed. The phantom was scanned using one medical full-body CT and two dentomaxillofacial cone beam CTs. The obtained images were imported to the Radia software, and the spatial resolution outputs were evaluated. The oversampling method was employed using our original wire phantom as a reference. The resultant modulation transfer function (MTF) curves were compared. The null hypothesis was that MTF curves generated using both methods would be in agreement. One-way analysis of variance tests were applied to the f50 and f10 values from the MTF curves. The f10 values were subjectively confirmed by observing the line pair modules. The Radia software reported the MTF curves on the xy-plane of the CT scans, but could not return f50 and f10 values on the z-axis. The null hypothesis concerning the reported MTF curves on the xy-plane was rejected. There were significant differences between the results of the Radia software and our reference method, except for f10 values in CS9300. These findings were consistent with our line pair observations. We evaluated the validity of the Radia software with the SEDENTEXCT IQ phantom. The data provided were semi-automatic, albeit with problems and statistically different from our reference. We hope the manufacturer will overcome these limitations.

Effect of gold nanoparticles on structure and dynamics of binary Lennard-Jones liquid: direct space analysis.

PubMed

Separdar, L; Davatolhagh, S

2013-02-01

We investigate the static structure and diffusive dynamics of binary Lennard-Jones mixture upon supercooling in the presence of gold nanoparticle within the framework of the mode-coupling theory of the dynamic glass transition in the direct space by means of constant-NVT molecular dynamics simulations. It is found that the presence of gold nanoparticle causes the energy per particle and the pressure of this system to decrease with respect to the bulk binary Lennard-Jones mixture. Furthermore, the presence of nanoparticle has a direct effect on the liquid structure and causes the peaks of the radial distribution functions to become shorter with respect to the bulk binary Lennard-Jones liquid. The dynamics of the liquid at a given density is found to be consistent with the mode-coupling theory (MCT) predictions in a certain range at low temperatures. In accordance with the idealized MCT, the diffusion constants D(T) show a power-law behavior at low temperatures for both types of binary Lennard-Jones (BLJ) particles as well as the gold atoms comprising the nanoparticle. The mode-coupling crossover temperature T(c) is the same for all particle types; however, T(c)=0.4 is reduced with respect to that of the bulk BLJ liquid, and the γ exponent is found to depend on the particle type. The existence of the nanoparticle causes the short-time β-relaxation regime to shorten and the range of validity of the MCT shrinks with respect to the bulk BLJ. It is also found that at intermediate and low temperatures the curves of the mean-squared displacements (MSDs) versus tD(T) fall onto a master curve. The MSDs follow the master curve in an identical time range with the long-time α-relaxation regime of the mode-coupling theory. By obtaining the viscosity, it is observed that the Stokes-Einstein relation remains valid at high and intermediate temperatures but breaks down as the temperatures approach T(c) as a result of the cooperative motion or activated processes.

Photometric evolution of seven recent novae and the double-component characterizing the light curve of those emitting in gamma rays

NASA Astrophysics Data System (ADS)

Munari, U.; Hambsch, F.-J.; Frigo, A.

2017-08-01

The BVI light curves of seven recent novae (I.e. V1534 Sco, V1535 Sco, V2949 Oph, V3661 Oph, MASTER OT J010603.18-744715.8, TCP J1734475-240942 and ASASSN-16ma) have been extensively mapped with daily robotic observations from Atacama (Chile): five belong to the Galactic bulge, one to the Small Magellanic Cloud and another is a Galactic disc object. The two programme novae detected in γ-rays by Fermi-LAT (I.e. TCP J1734475-240942 and ASASSN-16ma) are bulge objects with unevolved companions. They distinguish themselves by showing a double-component optical light curve. The first component to develop is the fireball from freely expanding, ballistic-launched ejecta, with a time of passage through maximum that is strongly dependent on wavelength (˜1 d delay between the B and I bands). The second component, emerging simultaneously with the nova detection in γ-rays, evolves at a slower pace, its optical brightness being proportional to the γ-ray flux, and its passage through maximum not dependent on wavelength. The fact that γ-rays are detected at a flux level that differs by four times from novae at the distance of the bulge seems to suggest that γ-ray emission is not a widespread property of normal novae. We discuss the advantages offered by high-quality photometric observations collected with only one telescope (as opposed to data provided by a number of different instruments). We also observe the effects of the wavelength dependence of fireball expansion, the recombination in the flashed wind of a giant companion, the subtle presence of hiccups and plateaus, and the super-soft X-ray emission and its switch-off. Four programme novae (V2949 Oph, V3661 Oph, TCP J18102829-2729590 and ASASSN-16ma) have normal dwarf companions: V1534 Sco contains an M3 III giant, V1535 Sco a K-type giant and MASTER OT J010603.18-744715.8 a subgiant. We also comment briefly on the maximum absolute magnitude relation with decline time (MMRD).

Electrorheological suspensions of laponite in oil: rheometry studies.

PubMed

Parmar, K P S; Méheust, Y; Schjelderupsen, Børge; Fossum, J O

2008-03-04

We have studied the effect of an external direct current (DC) electric field ( approximately 1 kV/mm) on the rheological properties of colloidal suspensions consisting of aggregates of laponite particles in a silicone oil. Microscopy observations show that, under application of an electric field greater than a triggering electric field Ec approximately 0.6 kV/mm, laponite aggregates assemble into chain- and/or columnlike structures in the oil. Without an applied electric field, the steady-state shear behavior of such suspensions is Newtonian-like. Under application of an electric field larger than Ec, it changes dramatically as a result of the changes in the microstructure: a significant yield stress is measured, and under continuous shear the fluid is shear-thinning. The rheological properties, in particular the dynamic and static shear stress, were studied as a function of particle volume fraction for various strengths (including null) of the applied electric field. The flow curves at constant shear rate can be scaled with respect to both the particle fraction and electric field strength onto a master curve. This scaling is consistent with simple scaling arguments. The shape of the master curve accounts for the system's complexity; it approaches a standard power-law model at high Mason numbers. Both dynamic and static yield stresses are observed to depend on the particle fraction Phi and electric field E as PhibetaEalpha, with alpha approximately 1.85 and beta approximately 1 and 1.70 for the dynamic and static yield stresses, respectively. The yield stress was also determined as the critical stress at which there occurs a bifurcation in the rheological behavior of suspensions that are submitted to a constant shear stress; a scaling law with alpha approximately 1.84 and beta approximately 1.70 was obtained. The effectiveness of the latter technique confirms that such electrorheological (ER) fluids can be studied in the framework of thixotropic fluids. The method is very reproducible; we suggest that it could be used routinely for studying ER fluids. The measured overall yield stress behavior of the suspensions may be explained in terms of standard conduction models for electrorheological systems. Interesting prospects include using such systems for guided self-assembly of clay nanoparticles.

Bioequivalence and Pharmacokinetic Evaluation Study of Acetaminophen vs. Acetaminophen Plus Caffeine Tablets in Healthy Mexican Volunteers.

PubMed

Guzmán, Nora Angélica Núñez; Molina, Daniel Ruiz; Núñez, Benigno Figueroa; Soto-Sosa, Juan Carlos; Abarca, Jorge Eduardo Herrera

2016-12-01

The aim of this clinical trial was to establish the bioequivalence of two tablets containing acetaminophen 650 mg (reference) and acetaminophen 650 mg plus caffeine 65 mg (test), administered orally, in fasting conditions in healthy Mexican volunteers. Blood samples were taken from 21 male and five female individuals, during a 24-h period, to characterize the pharmacokinetic profile of acetaminophen. Plasma samples were quantified by ultra-performance liquid chromatography, tandem mass spectrometry. Pharmacokinetic metrics (maximum plasma concentration, area under the curve from time zero to the last sampling time, and area under the curve from time zero to infinity) were used to determine the 90 % confidence interval of the test/reference coefficient. The geometric mean values for maximum plasma concentration obtained for the reference and test products were 9.46 ± 34.21 and 9.72 ± 32.38 µg/mL, respectively, whereas for the area under the curve from time zero to the last sampling time the values obtained were 34.93 ± 32.58 and 35.89 ± 31.03 µg h/mL for the reference and test formulations, respectively. The 90 % confidence intervals were within the acceptance range (80-125 %). The test product was bioequivalent to the reference product. A faster absorption was seen in the test formulation in the Mexican population.

Use of partial AUC (PAUC) to evaluate bioequivalence--a case study with complex absorption: methylphenidate.

PubMed

Fourie Zirkelbach, Jeanne; Jackson, Andre J; Wang, Yaning; Schuirmann, Donald J

2013-01-01

Methylphenidate modified-release products produce early and late peak concentrations critical for treatment of morning and afternoon symptoms of attention deficit hyperactivity disorder (ADHD). Standard bioequivalence (BE) criteria cannot be applied to these products. The performance of partial area under the drug concentration-time curve (PAUC), Cmax and AUCINF to assess BE were independently evaluated for two products. A two-stage analysis was performed on plasma data for two methylphenidate modified-release products (Product 1 and 2). Simulations using the fitted parameters determined how changes in fast absorption rate constant (K0Fast) and fraction available (F1) affected curve shape and BE determination using Cmax, AUCINF and PAUC. The sensitivity of the mean PAUC(test)/PAUC(reference) ratios to changes in K0Fast(test) are product dependent. Product 1 mean PAUC(test)/PAUC(reference) ratios for PAUC0-4h are more responsive to both decreases and increases in K0Fast(test) than Product 2. Product 2 showed a greater response in the mean PAUC(test)/PAUC(reference) ratio for PAUC0-4h when the K0Fast(test) is decreased and less response as the value is increased. PAUC estimated curve shape is sensitive to changes in absorption and are product specific, and may require a new PAUC metric for each drug. A non-product specific metric to assess curve shape is warranted.

Software Assurance Curriculum Project Volume 1: Master of Software Assurance Reference Curriculum

DTIC Science & Technology

2010-08-01

activity by providing a check on the relevance and currency of the process used to develop the MSwA2010 curriculum content. Figure 2 is an expansion of...random oracle model, symmetric crypto primitives, modes of operations, asymmetric crypto primitives (Chapter 5) [16] Detailed design...encryption, public key encryption, digital signatures, message authentication codes, crypto protocols, cryptanalysis, and further detailed crypto

The sonata form of musical composition as a framework for thesis writing.

PubMed

Drake, Maurice C

2004-01-01

In response to Watson's challenge to view the usual in new ways, this article introduces an innovation in writing Master's research and suggests that other structures may offer new and different frameworks for reporting nursing research. This is exemplified by reference to an example of nursing research which adopted the sonata-form of musical composition as the framework for presentation of the thesis.

Flemish Students' Historical Reference Knowledge and Narratives of the Belgian National Past at the End of Secondary Education

ERIC Educational Resources Information Center

Van Havere, Timo; Wils, Kaat; Depaepe, Fien; Verschaffel, Lieven; Van Nieuwenhuyse, Karel

2017-01-01

Since the early nineteenth century, western governments have expected history education to play a vital role in the formation of a national identity and the pursuit of national cohesion, by fostering shared knowledge and a shared (master)narrative of the national past. This article reports on a qualitative study that examines which narratives…

B-Type Natriuretic Peptide Reactivity to Mental Stress and Exercise: Role of Obesity and Hemodynamics

DTIC Science & Technology

2009-08-25

both of which increase SV and CO (Figure 16). Specifically, circulating catecholamines decrease venous compliance and increase central venous pressure...t Inotropy t Central Venous Pressure , t Preload / t SV&CO 104 References 1. The Criteria Committee of the New York Heart Association...Science Degrees -Public Health Masters Degrees -Military Medical History -Public Health -Tropical Medicine & Hygiene Graduate Education Office

Constructing Quality Feedback to the Students in Distance Learning: Review of the Current Evidence with Reference to the Online Master Degree in Transplantation

ERIC Educational Resources Information Center

Halawa, Ahmed; Sharma, Ajay; Bridson, Julie M.; Lyon, Sarah; Prescott, Denise; Guha, Arpan; Taylor, David

2017-01-01

Introduction: It was a challenge to design a feedback pathway for distance learning course that deals with complex and ambiguous clinical subject like organ transplantation. This course attracts mature clinicians (n = 117 spread over three modules) from 27 countries where in addition to the time and zone barriers; there are cultural, institutional…

Strategic Munitions Planning in Non-Conventional Asymmetric Operations

DTIC Science & Technology

2010-04-01

Conventional Asymmetric Operations RTO-MP-SAS-081 16 - 3 with a clearly structured, sized and located military force. The principles of Lanchester ...stockpiles and calculated munitions requirements. REFERENCES [1] Prague Summit Declaration, November 2002. [2] J. Fletcher, The Lanchester Legacy... Lanchester battles, Journal of the Operational Research Society, Vol. 50 No. 3, March 1999. [13] W. Freeman, A Study of Ammunition Consumption, Master of

Electromagnetic Resonances of Metallic Bodies.

DTIC Science & Technology

1997-06-01

complex objects. MOM creates a discrete model of the object by dividing the object into electrically small charge and current segments referred to as the...distribution is unlimited ELECROMAGNETIC RESONANCES OF METALLIC BODIES William A. Lintz Lieutenant, United States Navy B.E.E., Villanova University, 1992...Submitted in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE IN ELECTRICAL ENGINEERING from the NAVAL POSTGRADUATE SCHOOL June

Team Attributes & Team Performance - FY14-7 Expert Performance and Measurement

DTIC Science & Technology

2014-10-26

this material are those of the author(s) and do not necessarily reflect the views of the United States Department of Defense. References herein...Abilities Personality Traits Attitudes and Beliefs Our contribution: Teamwork Skills Metacognitive Skills 12 Fall 2014 SEI Research Review...Expert Master Personality: • Curious • Self -motivated • Conscientiousness Teamwork Attitudes: • Attracted to working with smart people Abilities

Patient Satisfaction in Military Dental Treatment Facilities

DTIC Science & Technology

2006-03-07

assessing satisfaction. Dental Patient Satisfaction 58 References Abidi, H. (2003). Encyclopedia of Social Sciences Research Methods . Thousand Oaks (CA...Care System that gave me the opportunity to attend the Baylor Program and to complete the dual Masters in Business Administration program at The...Patient satisfaction is an integral component of the report cards and thus military dentistry had to develop a method of standardizing the assessment of

Improved instrumental magnitude prediction expected from version 2 of the NASA SKY2000 master star catalog

NASA Technical Reports Server (NTRS)

Sande, C. B.; Brasoveanu, D.; Miller, A. C.; Home, A. T.; Tracewell, D. A.; Warren, W. H., Jr.

1998-01-01

The SKY2000 Master Star Catalog (MC), Version 2 and its predecessors have been designed to provide the basic astronomical input data needed for satellite acquisition and attitude determination on NASA spacecraft. Stellar positions and proper motions are the primary MC data required for operations support followed closely by the stellar brightness observed in various standard astronomical passbands. The instrumental red-magnitude prediction subsystem (REDMAG) in the MMSCAT software package computes the expected instrumental color index (CI) [sensor color correction] from an observed astronomical stellar magnitude in the MC and the characteristics of the stellar spectrum, astronomical passband, and sensor sensitivity curve. The computation is more error prone the greater the mismatch of the sensor sensitivity curve characteristics and those of the observed astronomical passbands. This paper presents the preliminary performance analysis of a typical red-sensitive CCDST during acquisition of sensor data from the two Ball CT-601 ST's onboard the Rossi X-Ray Timing Explorer (RXTE). A comparison is made of relative star positions measured in the ST FOV coordinate system with the expected results computed from the recently released Tycho Catalogue. The comparison is repeated for a group of observed stars with nearby, bright neighbors in order to determine the tracker behavior in the presence of an interfering, near neighbor (NN). The results of this analysis will be used to help define a new photoelectric photometric instrumental sensor magnitude system (S) that is based on several thousand bright star magnitudes observed with the PXTE ST's. This new system will be implemented in Version 2 of the SKY2000 MC to provide improved predicted magnitudes in the mission run catalogs.

Excess entropy scaling for the segmental and global dynamics of polyethylene melts.

PubMed

Voyiatzis, Evangelos; Müller-Plathe, Florian; Böhm, Michael C

2014-11-28

The range of validity of the Rosenfeld and Dzugutov excess entropy scaling laws is analyzed for unentangled linear polyethylene chains. We consider two segmental dynamical quantities, i.e. the bond and the torsional relaxation times, and two global ones, i.e. the chain diffusion coefficient and the viscosity. The excess entropy is approximated by either a series expansion of the entropy in terms of the pair correlation function or by an equation of state for polymers developed in the context of the self associating fluid theory. For the whole range of temperatures and chain lengths considered, the two estimates of the excess entropy are linearly correlated. The scaled bond and torsional relaxation times fall into a master curve irrespective of the chain length and the employed scaling scheme. Both quantities depend non-linearly on the excess entropy. For a fixed chain length, the reduced diffusion coefficient and viscosity scale linearly with the excess entropy. An empirical reduction to a chain length-independent master curve is accessible for both dynamic quantities. The Dzugutov scheme predicts an increased value of the scaled diffusion coefficient with increasing chain length which contrasts physical expectations. The origin of this trend can be traced back to the density dependence of the scaling factors. This finding has not been observed previously for Lennard-Jones chain systems (Macromolecules, 2013, 46, 8710-8723). Thus, it limits the applicability of the Dzugutov approach to polymers. In connection with diffusion coefficients and viscosities, the Rosenfeld scaling law appears to be of higher quality than the Dzugutov approach. An empirical excess entropy scaling is also proposed which leads to a chain length-independent correlation. It is expected to be valid for polymers in the Rouse regime.

Lithium target performance evaluation for low-energy accelerator-based in vivo measurements using gamma spectroscopy.

PubMed

Aslam; Prestwich, W V; McNeill, F E

2003-03-01

The operating conditions at McMaster KN Van de Graaf accelerator have been optimized to produce neutrons via the (7)Li(p, n)(7)Be reaction for in vivo neutron activation analysis. In a number of earlier studies (development of an accelerator based system for in vivo neutron activation analysis measurements of manganese in humans, Ph.D. Thesis, McMaster University, Hamilton, ON, Canada; Appl. Radiat. Isot. 53 (2000) 657; in vivo measurement of some trace elements in human Bone, Ph.D. Thesis. McMaster University, Hamilton, ON, Canada), a significant discrepancy between the experimental and the calculated neutron doses has been pointed out. The hypotheses formulated in the above references to explain the deviation of the experimental results from analytical calculations, have been tested experimentally. The performance of the lithium target for neutron production has been evaluated by measuring the (7)Be activity produced as a result of (p, n) interaction with (7)Li. In contradiction to the formulated hypotheses, lithium target performance was found to be mainly affected by inefficient target cooling and the presence of oxides layer on target surface. An appropriate choice of these parameters resulted in neutron yields same as predicated by analytical calculations.

Ray-tracing of shape metrology data of grazing incidence x-ray astronomy mirrors

NASA Astrophysics Data System (ADS)

Zocchi, Fabio E.; Vernani, Dervis

2008-07-01

A number of future X-ray astronomy missions (e.g. Simbol-X, eROSITA) plan to utilize high throughput grazing incidence optics with very lightweight mirrors. The severe mass specifications require a further optimization of the existing technology with the consequent need of proper optical numerical modeling capabilities for both the masters and the mirrors. A ray tracing code has been developed for the simulation of the optical performance of type I Wolter masters and mirrors starting from 2D and 3D metrology data. In particular, in the case of 2D measurements, a 3D data set is reconstructed on the basis of dimensional references and used for the optical analysis by ray tracing. In this approach, the actual 3D shape is used for the optical analysis, thus avoiding the need of combining the separate contributions of different 2D measurements that require the knowledge of their interactions which is not normally available. The paper describes the proposed approach and presents examples of application on a prototype engineering master in the frame of ongoing activities carried out for present and future X-ray missions.

A Least Square Approach for Joining Persistent Scatterer InSAR Time Series Acquired by Different Satellites

NASA Astrophysics Data System (ADS)

Caro Cuenca, Miguel; Esfahany, Sami Samiei; Hanssen, Ramon F.

2010-12-01

Persistent scatterer Radar Interferometry (PSI) can provide with a wealth of information on surface motion. These methods overcome the major limitations of the antecessor technique, interferometric SAR (InSAR), such as atmospheric disturbances, by detecting the scatterers which are slightly affected by noise. The time span that surface deformation processes are observed is limited by the satellite lifetime, which is usually less than 10 years. However most of deformation phenomena last longer. In order to fully monitor and comprehend the observed signal, acquisitions from different sensors can be merged. This is a complex task for one main reason. PSI methods provide with estimations that are relative in time to one of the acquisitions which is referred to as master or reference image. Therefore, time series acquired by different sensors will have different reference images and cannot be directly compared or joint unless they are set to the same time reference system. In global terms, the operation of translating from one to another reference systems consist of calculating a vertical offset, which is the total deformation that occurs between the two master times. To estimate this offset, different strategies can be applied, for example, using additional data such as leveling or GPS measurements. In this contribution we propose to use a least squares to merge PSI time series without any ancillary information. This method treats the time series individually, i.e. per PS, and requires some knowledge of the deformation signal, for example, if a polynomial would fairly describe the expected behavior. To test the proposed approach, we applied it to the southern Netherlands, where the surface is affected by ground water processes in abandoned mines. The time series were obtained after processing images provided by ERS1/2 and Envisat. The results were validated using in-situ water measurements, which show very high correlation with deformation time series.

Monitoring hydrofrac-induced seismicity by surface arrays - the DHM-Project Basel case study

NASA Astrophysics Data System (ADS)

Blascheck, P.; Häge, M.; Joswig, M.

2012-04-01

The method "nanoseismic monitoring" was applied during the hydraulic stimulation at the Deep-Heat-Mining-Project (DHM-Project) Basel. Two small arrays in a distance of 2.1 km and 4.8 km to the borehole recorded continuously for two days. During this time more than 2500 seismic events were detected. The method of the surface monitoring of induced seismicity was compared to the reference which the hydrofrac monitoring presented. The latter was conducted by a network of borehole seismometers by Geothermal Explorers Limited. Array processing provides a outlier resistant, graphical jack-knifing localization method which resulted in a average deviation towards the reference of 850 m. Additionally, by applying the relative localization master-event method, the NNW-SSE strike direction of the reference was confirmed. It was shown that, in order to successfully estimate the magnitude of completeness as well as the b-value at the event rate and detection sensibility present, 3 h segments of data are sufficient. This is supported by two segment out of over 13 h of evaluated data. These segments were chosen so that they represent a time during the high seismic noise during normal working hours in daytime as well as the minimum anthropogenic noise at night. The low signal-to-noise ratio was compensated by the application of a sonogram event detection as well as a coincidence analysis within each array. Sonograms allow by autoadaptive, non-linear filtering to enhance signals whose amplitudes are just above noise level. For these events the magnitude was determined by the master-event method, allowing to compute the magnitude of completeness by the entire-magnitude-range method provided by the ZMAP toolbox. Additionally, the b-values were determined and compared to the reference values. An introduction to the method of "nanoseismic monitoring" will be given as well as the comparison to reference data in the Basel case study.

Brownian motion in non-equilibrium systems and the Ornstein-Uhlenbeck stochastic process.

PubMed

Donado, F; Moctezuma, R E; López-Flores, L; Medina-Noyola, M; Arauz-Lara, J L

2017-10-03

The Ornstein-Uhlenbeck stochastic process is an exact mathematical model providing accurate representations of many real dynamic processes in systems in a stationary state. When applied to the description of random motion of particles such as that of Brownian particles, it provides exact predictions coinciding with those of the Langevin equation but not restricted to systems in thermal equilibrium but only conditioned to be stationary. Here, we investigate experimentally single particle motion in a two-dimensional granular system in a stationary state, consisting of 1 mm stainless balls on a plane circular surface. The motion of the particles is produced by an alternating magnetic field applied perpendicular to the surface of the container. The mean square displacement of the particles is measured for a range of low concentrations and it is found that following an appropriate scaling of length and time, the short-time experimental curves conform a master curve covering the range of particle motion from ballistic to diffusive in accordance with the description of the Ornstein-Uhlenbeck model.

Piezoresistive strain sensing of carbon black /silicone composites above percolation threshold

NASA Astrophysics Data System (ADS)

Shang, Shuying; Yue, Yujuan; Wang, Xiaoer

2016-12-01

A series of flexible composites with a carbon black (CB) filled silicone rubber matrix were made by an improved process in this work. A low percolation threshold with a mass ratio of 2.99% CB was achieved. The piezoresistive behavior of CB/silicone composites above the critical value, with the mass ratio of carbon black to the silicone rubber ranging from 0.01 to 0.2, was studied. The piezoresistive behavior was different from each other for the composites with different CB contents. But, the composites show an excellent repeatability of piezoresistivity under cyclic compression, no matter with low filler content or with high filler content. The most interesting phenomena were that the plots of gauge factor versus strain of the composites with different CB contents constructed a master curve and the curve could be well fitted by a function. It was showed that the gauge factor of the composites was strain-controlled showing a promising prospect of application.

On the consideration of scaling properties of extreme rainfall in Madrid (Spain) for developing a generalized intensity-duration-frequency equation and assessing probable maximum precipitation estimates

NASA Astrophysics Data System (ADS)

Casas-Castillo, M. Carmen; Rodríguez-Solà, Raúl; Navarro, Xavier; Russo, Beniamino; Lastra, Antonio; González, Paula; Redaño, Angel

2018-01-01

The fractal behavior of extreme rainfall intensities registered between 1940 and 2012 by the Retiro Observatory of Madrid (Spain) has been examined, and a simple scaling regime ranging from 25 min to 3 days of duration has been identified. Thus, an intensity-duration-frequency (IDF) master equation of the location has been constructed in terms of the simple scaling formulation. The scaling behavior of probable maximum precipitation (PMP) for durations between 5 min and 24 h has also been verified. For the statistical estimation of the PMP, an envelope curve of the frequency factor ( k m ) based on a total of 10,194 station-years of annual maximum rainfall from 258 stations in Spain has been developed. This curve could be useful to estimate suitable values of PMP at any point of the Iberian Peninsula from basic statistical parameters (mean and standard deviation) of its rainfall series. [Figure not available: see fulltext.

Multidomain proteins under force

NASA Astrophysics Data System (ADS)

Valle-Orero, Jessica; Andrés Rivas-Pardo, Jaime; Popa, Ionel

2017-04-01

Advancements in single-molecule force spectroscopy techniques such as atomic force microscopy and magnetic tweezers allow investigation of how domain folding under force can play a physiological role. Combining these techniques with protein engineering and HaloTag covalent attachment, we investigate similarities and differences between four model proteins: I10 and I91—two immunoglobulin-like domains from the muscle protein titin, and two α + β fold proteins—ubiquitin and protein L. These proteins show a different mechanical response and have unique extensions under force. Remarkably, when normalized to their contour length, the size of the unfolding and refolding steps as a function of force reduces to a single master curve. This curve can be described using standard models of polymer elasticity, explaining the entropic nature of the measured steps. We further validate our measurements with a simple energy landscape model, which combines protein folding with polymer physics and accounts for the complex nature of tandem domains under force. This model can become a useful tool to help in deciphering the complexity of multidomain proteins operating under force.

Signal processing system for electrotherapy applications

NASA Astrophysics Data System (ADS)

Płaza, Mirosław; Szcześniak, Zbigniew

2017-08-01

The system of signal processing for electrotherapeutic applications is proposed in the paper. The system makes it possible to model the curve of threshold human sensitivity to current (Dalziel's curve) in full medium frequency range (1kHz-100kHz). The tests based on the proposed solution were conducted and their results were compared with those obtained according to the assumptions of High Tone Power Therapy method and referred to optimum values. Proposed system has high dynamics and precision of mapping the curve of threshold human sensitivity to current and can be used in all methods where threshold curves are modelled.

Characteristic overpressure-impulse-distance curves for vapour cloud explosions using the TNO Multi-Energy model.

PubMed

Díaz Alonso, Fernando; González Ferradás, Enrique; Sánchez Pérez, Juan Francisco; Miñana Aznar, Agustín; Ruiz Gimeno, José; Martínez Alonso, Jesús

2006-09-21

A number of models have been proposed to calculate overpressure and impulse from accidental industrial explosions. When the blast is produced by ignition of a vapour cloud, the TNO Multi-Energy model is widely used. From the curves given by this model, data are fitted to obtain equations showing the relationship between overpressure, impulse and distance. These equations, referred herein as characteristic curves, can be fitted by means of power equations, which depend on explosion energy and charge strength. Characteristic curves allow the determination of overpressure and impulse at each distance.

Optical distribution of local oscillators in future telecommunication satellite payloads

NASA Astrophysics Data System (ADS)

Benazet, Benoît; Sotom, Michel; Maignan, Michel; Berthon, Jacques

2017-11-01

The distribution of high spectral purity reference signals over optical fibre in future telecommunication satellite payloads is presented. Several types of applications are considered, including the distribution of a reference frequency at 10 MHz (Ultra-Stable Reference Oscillator) as well as the distribution of a radiofrequency oscillator around 800 MHz (Master Local Oscillator). The results of both experimental and theoretical studies are reported. In order to meet phase noise requirements for the USRO distribution, the use of an optimised receiver circuit based on an optically synchronised oscillator is investigated. Finally, the optical distribution of microwave local oscillators at frequencies exceeding 20 GHz is described. Such a scheme paves the way to more advanced sub-systems involving optical frequency-mixing and optical transmission of microwave signals, with applications to multiple-beam active antennas.

Applying critical thinking to nursing.

PubMed

Price, Bob

2015-08-19

Critical thinking and writing are skills that are not easy to acquire. The term 'critical' is used differently in social and clinical contexts. Nursing students need time to master the inquisitive and ruminative aspects of critical thinking that are required in academic environments. This article outlines what is meant by critical thinking in academic settings, in relation to both theory and reflective practice. It explains how the focus of a question affects the sort of critical thinking required and offers two taxonomies of learning, to which students can refer when analysing essay requirements. The article concludes with examples of analytical writing in reference to theory and reflective practice.

Light deflection and Gauss-Bonnet theorem: definition of total deflection angle and its applications

NASA Astrophysics Data System (ADS)

Arakida, Hideyoshi

2018-05-01

In this paper, we re-examine the light deflection in the Schwarzschild and the Schwarzschild-de Sitter spacetime. First, supposing a static and spherically symmetric spacetime, we propose the definition of the total deflection angle α of the light ray by constructing a quadrilateral Σ^4 on the optical reference geometry M^opt determined by the optical metric \\bar{g}_{ij}. On the basis of the definition of the total deflection angle α and the Gauss-Bonnet theorem, we derive two formulas to calculate the total deflection angle α ; (1) the angular formula that uses four angles determined on the optical reference geometry M^opt or the curved (r, φ ) subspace M^sub being a slice of constant time t and (2) the integral formula on the optical reference geometry M^opt which is the areal integral of the Gaussian curvature K in the area of a quadrilateral Σ ^4 and the line integral of the geodesic curvature κ _g along the curve C_{Γ}. As the curve C_{Γ}, we introduce the unperturbed reference line that is the null geodesic Γ on the background spacetime such as the Minkowski or the de Sitter spacetime, and is obtained by projecting Γ vertically onto the curved (r, φ ) subspace M^sub. We demonstrate that the two formulas give the same total deflection angle α for the Schwarzschild and the Schwarzschild-de Sitter spacetime. In particular, in the Schwarzschild case, the result coincides with Epstein-Shapiro's formula when the source S and the receiver R of the light ray are located at infinity. In addition, in the Schwarzschild-de Sitter case, there appear order O(Lambda;m) terms in addition to the Schwarzschild-like part, while order O(Λ) terms disappear.

Weight, height and body mass index of children and adolescents living at moderate altitude in Colombia.

PubMed

Díaz Bonilla, Edilberto; Torres Galvis, Claudia L; Gómez Campos, Rossana; de Arruda, Miguel; Pacheco Carrillo, Jaime; Cossio Bolaños, Marco

2018-04-01

There is increasing concern over the study of physical growth in different regions of the world, although altitude is not considered an adjustment factor. Compare physical growth variables and body mass index (BMI) patterns with the Centers for Disease Control and Prevention (CDC) 2012 reference data and develop percentiles for children and adolescents. School children living at moderate altitude in Bogotá (Colombia) were studied. Their weight and height were evaluated and their BMI was calculated. Anthropometric variables were compared against reference data of the CDC-2012, Brazil, Peru and Argentina. Curves were constructed using the least mean square (LMS) method. A total of 2241 school children (1159 girls) aged 6.0 to 17.9 years were included. There were no significant differences in weight and BMI in 6 to 8 year-olds relative to CDC-2012 reference data; in 9 to 17 year-old children, however, this sample evidenced lower values in terms of weight and BMI as compared to those of the CDC-2012. As far as height is concerned, in both sexes, values were lower than those of the CDC-2012. Comparisons against the regional curves of Argentina, Peru and Brazil yielded relatively similar results, with the exception of girls' BMI, as 13 to 17 year-old girls exhibited lower values. Growth variables of school children were lower relative to the CDC-2012 reference data. There were slight discrepancies in physical growth and BMI in relation to the curves of Argentina, Peru and Brazil. Curves were constructed to evaluate growth in school children living at moderate altitude in Colombia. Sociedad Argentina de Pediatría.

77 FR 75697 - Petition for Waiver of Compliance

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-21

... wheel loads when a rail vehicle traverses a curve. With the right combination of speed, curvature, and... wheels will be equal, i.e., balanced. The curving speed corresponding to this balanced state is referred... the outer wheel load to increase and the inner wheel load to decrease. The manifestation of this load...

Report of the River Master of the Delaware River for the period December 1, 1984 - November 30, 1985

USGS Publications Warehouse

Schaefer, F.T.; Harkness, W.E.; Cecil, L.D.

1986-01-01

A Decree of the Supreme Court of the United States in 1954 established the position of Delaware River Master. The Decree authorizes diversions of water from the Delaware River basin and requires compensating releases from certain reservoirs of the City of New York to be made under the supervision and direction of the River Master. Reports to the Court, not less frequently than annually, were stipulated. During the 1985 report year, December 1, 1984, to November 30, 1985, precipitation and runoff varied from below average to above average in the Delaware River basin. For the year as a whole, precipitation was near average. Runoff was below average. Operations were under a status of drought warning or drought from January 23, 1984, through the end of the report year. Below-normal precipitation the first half of the year resulted in decreased storage in the reservoirs to record low levels by March 1, 1985. Storage remained at record low levels from March through September. Above-normal precipitation in September and November served to break the drought and increase storage into the normal zone of the operating curves for the reservoirs. Diversions from the Delaware River basin by New York City did not exceed those authorized by the terms of the Amended Decree or those invoked by the several emergency conservation measures throughout the year. There were no diversions from the Delaware River basin by New Jersey during the year. Releases were made as directed by the River Master at rates designed to meet the Montague flow objective on 82 days between June 14 and September 28. Releases were made at conservation rates or at rates designed to relieve thermal stress in the streams downstream from the reservoirs at other times. (See also W89-04133) (USGS)

The Chandra Source Catalog: User Interface

NASA Astrophysics Data System (ADS)

Bonaventura, Nina; Evans, I. N.; Harbo, P. N.; Rots, A. H.; Tibbetts, M. S.; Van Stone, D. W.; Zografou, P.; Anderson, C. S.; Chen, J. C.; Davis, J. E.; Doe, S. M.; Evans, J. D.; Fabbiano, G.; Galle, E.; Gibbs, D. G.; Glotfelty, K. J.; Grier, J. D.; Hain, R.; Hall, D. M.; He, X.; Houck, J. C.; Karovska, M.; Lauer, J.; McCollough, M. L.; McDowell, J. C.; Miller, J. B.; Mitschang, A. W.; Morgan, D. L.; Nichols, J. S.; Nowak, M. A.; Plummer, D. A.; Primini, F. A.; Refsdal, B. L.; Siemiginowska, A. L.; Sundheim, B. A.; Winkelman, S. L.

2009-01-01

The Chandra Source Catalog (CSC) is the definitive catalog of all X-ray sources detected by Chandra. The CSC is presented to the user in two tables: the Master Chandra Source Table and the Table of Individual Source Observations. Each distinct X-ray source identified in the CSC is represented by a single master source entry and one or more individual source entries. If a source is unaffected by confusion and pile-up in multiple observations, the individual source observations are merged to produce a master source. In each table, a row represents a source, and each column a quantity that is officially part of the catalog. The CSC contains positions and multi-band fluxes for the sources, as well as derived spatial, spectral, and temporal source properties. The CSC also includes associated source region and full-field data products for each source, including images, photon event lists, light curves, and spectra. The master source properties represent the best estimates of the properties of a source, and are presented in the following categories: Position and Position Errors, Source Flags, Source Extent and Errors, Source Fluxes, Source Significance, Spectral Properties, and Source Variability. The CSC Data Access GUI provides direct access to the source properties and data products contained in the catalog. The user may query the catalog database via a web-style search or an SQL command-line query. Each query returns a table of source properties, along with the option to browse and download associated data products. The GUI is designed to run in a web browser with Java version 1.5 or higher, and may be accessed via a link on the CSC website homepage (http://cxc.harvard.edu/csc/). As an alternative to the GUI, the contents of the CSC may be accessed directly through a URL, using the command-line tool, cURL. Support: NASA contract NAS8-03060 (CXC).

Semi-automatic delineation of the spino-laminar junction curve on lateral x-ray radiographs of the cervical spine

NASA Astrophysics Data System (ADS)

Narang, Benjamin; Phillips, Michael; Knapp, Karen; Appelboam, Andy; Reuben, Adam; Slabaugh, Greg

2015-03-01

Assessment of the cervical spine using x-ray radiography is an important task when providing emergency room care to trauma patients suspected of a cervical spine injury. In routine clinical practice, a physician will inspect the alignment of the cervical spine vertebrae by mentally tracing three alignment curves along the anterior and posterior sides of the cervical vertebral bodies, as well as one along the spinolaminar junction. In this paper, we propose an algorithm to semi-automatically delineate the spinolaminar junction curve, given a single reference point and the corners of each vertebral body. From the reference point, our method extracts a region of interest, and performs template matching using normalized cross-correlation to find matching regions along the spinolaminar junction. Matching points are then fit to a third order spline, producing an interpolating curve. Experimental results demonstrate promising results, on average producing a modified Hausdorff distance of 1.8 mm, validated on a dataset consisting of 29 patients including those with degenerative change, retrolisthesis, and fracture.

Review of Jones-Wilkins-Lee equation of state

NASA Astrophysics Data System (ADS)

Baudin, G.; Serradeill, R.

The JWL EOS is widely used in different forms (two, three terms) according to the level of accuracy in the pressure-volume domain that applications need. The foundations of the relationship chosen to represent the reference curve, Chapman-Jouguet (CJ) isentrope, can be found assuming that the DP expansion isentrope issued from the CJ point is very nearly coincident with the Crussard curve in the pressure-material velocity plane. Its mathematical expression, using an appropriate relationship between shock velocity and material velocity leads to the exponential terms of the JWL EOS. It well validates the pressure-volume relationship chosen to represent the reference curves for DP. Nevertheless, the assumption of constant Gruneisen coefficient and heat capacity in the EOS thermal part remains the more restrictive assumption. A new derivation of JWL EOS is proposed, using a less restrictive assumption for the Gruneisen coefficient suggested by W.C. Davis to represent both large expansions and near-CJ states.

Growth curves of preschool children in the northeast of iran: a population based study using quantile regression approach.

PubMed

Payande, Abolfazl; Tabesh, Hamed; Shakeri, Mohammad Taghi; Saki, Azadeh; Safarian, Mohammad

2013-01-14

Growth charts are widely used to assess children's growth status and can provide a trajectory of growth during early important months of life. The objectives of this study are going to construct growth charts and normal values of weight-for-age for children aged 0 to 5 years using a powerful and applicable methodology. The results compare with the World Health Organization (WHO) references and semi-parametric LMS method of Cole and Green. A total of 70737 apparently healthy boys and girls aged 0 to 5 years were recruited in July 2004 for 20 days from those attending community clinics for routine health checks as a part of a national survey. Anthropometric measurements were done by trained health staff using WHO methodology. The nonparametric quantile regression method obtained by local constant kernel estimation of conditional quantiles curves using for estimation of curves and normal values. The weight-for-age growth curves for boys and girls aged from 0 to 5 years were derived utilizing a population of children living in the northeast of Iran. The results were similar to the ones obtained by the semi-parametric LMS method in the same data. Among all age groups from 0 to 5 years, the median values of children's weight living in the northeast of Iran were lower than the corresponding values in WHO reference data. The weight curves of boys were higher than those of girls in all age groups. The differences between growth patterns of children living in the northeast of Iran versus international ones necessitate using local and regional growth charts. International normal values may not properly recognize the populations at risk for growth problems in Iranian children. Quantile regression (QR) as a flexible method which doesn't require restricted assumptions, proposed for estimation reference curves and normal values.

Growth Curves of Preschool Children in the Northeast of Iran: A Population Based Study Using Quantile Regression Approach

PubMed Central

Payande, Abolfazl; Tabesh, Hamed; Shakeri, Mohammad Taghi; Saki, Azadeh; Safarian, Mohammad

2013-01-01

Introduction: Growth charts are widely used to assess children’s growth status and can provide a trajectory of growth during early important months of life. The objectives of this study are going to construct growth charts and normal values of weight-for-age for children aged 0 to 5 years using a powerful and applicable methodology. The results compare with the World Health Organization (WHO) references and semi-parametric LMS method of Cole and Green. Methods: A total of 70737 apparently healthy boys and girls aged 0 to 5 years were recruited in July 2004 for 20 days from those attending community clinics for routine health checks as a part of a national survey. Anthropometric measurements were done by trained health staff using WHO methodology. The nonparametric quantile regression method obtained by local constant kernel estimation of conditional quantiles curves using for estimation of curves and normal values. Results: The weight-for-age growth curves for boys and girls aged from 0 to 5 years were derived utilizing a population of children living in the northeast of Iran. The results were similar to the ones obtained by the semi-parametric LMS method in the same data. Among all age groups from 0 to 5 years, the median values of children’s weight living in the northeast of Iran were lower than the corresponding values in WHO reference data. The weight curves of boys were higher than those of girls in all age groups. Conclusion: The differences between growth patterns of children living in the northeast of Iran versus international ones necessitate using local and regional growth charts. International normal values may not properly recognize the populations at risk for growth problems in Iranian children. Quantile regression (QR) as a flexible method which doesn’t require restricted assumptions, proposed for estimation reference curves and normal values. PMID:23618470

Waist circumference percentile curves for Malaysian children and adolescents aged 6.0-16.9 years.

PubMed

Poh, Bee Koon; Jannah, Ahmad Nurul; Chong, Lai Khuen; Ruzita, Abd Talib; Ismail, Mohd Noor; McCarthy, David

2011-08-01

The prevalence of obesity is increasing rapidly and abdominal obesity especially is known to be a risk factor for metabolic syndrome and other non-communicable diseases. Waist circumference percentile curves are useful tools which can help to identify abdominal obesity among the childhood and adolescent populations. To develop age- and sex-specific waist circumference (WC) percentile curves for multi-ethnic Malaysian children and adolescents aged 6.0-16.9 years. Subjects and methods. A total of 16,203 participants comprising 8,093 boys and 8,110 girls recruited from all regions of Malaysia were involved in this study. Height, weight, WC were measured and BMI calculated. Smoothed WC percentile curves and values for the 3rd, 5th, 10th, 25th, 50th, 75th, 90th, 95th and 97th percentiles were constructed using the LMS Method. WC was found to increase with age in both sexes, but boys had higher WC values at every age and percentile. Z-scores generated using the UK reference data shows that Chinese children had the highest WC compared to Malays, Indians and other ethnicities. Comparisons with other studies indicate that at the 50th percentile, Malaysian curves did not differ from the UK, Hong Kong and Turkish curves, but at the 90th percentile, Malaysian curves were higher compared with other countries, starting at 10 years of age. The 90th percentile was adopted as the cut-off point to indicate abdominal obesity in Malaysian children and adolescents. These curves represent the first WC percentiles reported for Malaysian children, and they can serve as a reference for future studies.

Ecological quality boundary-setting procedures: the Gulf of Riga case study.

PubMed

Aigars, Juris; Müller-Karulis, Bärbel; Martin, Georg; Jermakovs, Vadims

2008-03-01

Two approaches for setting ecological class boundaries, response curves and a simplified mathematical boundary-setting protocol, were tested for coastal, transitional and open waters in the Gulf of Riga, Baltic Sea. The simplified mathematical boundary-setting protocol defines acceptable ecological status based on expert judgment by a uniform relative deviation from reference conditions. In contrast, response curves derive class boundary definitions from observed changes in biological quality elements along environmental pressure gradients for class boundary definitions. Identification of relevant environmental pressures for the construction of response curves was based on a conceptual model of eutrophication in the Gulf of Riga. Response curves were successfully established for summer chlorophyll a and transparency, as well as for macrozoobenthos abundance in the Central Gulf, macrozoobenthos biotic coefficient in the Southern Gulf, and maximum depth of phytobenthos in the Northern Gulf. In the Gulf of Riga response curves almost always permitted a larger deviation from reference conditions than the 50% deviation applied for the simplified mathematical boundary-setting protocol. The case study clearly demonstrated that class boundary definitions should take into account the sensitivity of the target water body. Also, the class boundaries for different ecological quality elements were internally more consistent than those derived by the simplified mathematical boundary-setting protocol.

Can anthropometry measure gender discrimination? An analysis using WHO standards to assess the growth of Bangladeshi children.

PubMed

Moestue, Helen

2009-08-01

To examine the potential of anthropometry as a tool to measure gender discrimination, with particular attention to the WHO growth standards. Surveillance data collected from 1990 to 1999 were analysed. Height-for-age Z-scores were calculated using three norms: the WHO standards, the 1978 National Center for Health Statistics (NCHS) reference and the 1990 British growth reference (UK90). Bangladesh. Boys and girls aged 6-59 months (n 504 358). The three sets of growth curves provided conflicting pictures of the relative growth of girls and boys by age and over time. Conclusions on sex differences in growth depended also on the method used to analyse the curves, be it according to the shape or the relative position of the sex-specific curves. The shapes of the WHO-generated curves uniquely implied that Bangladeshi girls faltered faster or caught up slower than boys throughout their pre-school years, a finding consistent with the literature. In contrast, analysis of the relative position of the curves suggested that girls had higher WHO Z-scores than boys below 24 months of age. Further research is needed to help establish whether and how the WHO international standards can measure gender discrimination in practice, which continues to be a serious problem in many parts of the world.

Tensile Properties of 17-7 PH and 12 MoV Stainless-Steel Sheet under Rapid-Heating and Constant-Temperature Conditions

NASA Technical Reports Server (NTRS)

Manning, Charles R., Jr.; Price, Howard L.

1961-01-01

Results are presented of rapid-heating tests of 17-7 PH and 12 MoV stainless-steel sheet heated to failure at temperature rates from about 1 F to 170 F per second under constant-load conditions. Yield and rupture strengths obtained from rapid-heating tests are compared with yield and tensile strengths obtained from short-time elevated-temperature tensile tests (30-minute exposure). A rate-temperature parameter was used to construct master curves from which yield and rupture stresses or temperatures can be predicted. A method for measuring strain by optical means is described.

Experience with SI units in biochemistry.

PubMed

Karnauchow, P N; Suvanto, L

1976-03-20

Use of Système International d'Unités (SI) for laboratory measurements was instituted Jan. 1, 1975 at two community hospitals. Beforehand, talks were given, pamphlets, conversion tables, new calibration curves and new master record cards were printed, computer cards were reprogrammed and conversion kits were prepared; the total cost was less than $200. After 6 months 16% of the medical staff had stopped converting SI units into conventional units, 78% were still occasionally converting units and 6% were routinely converting units. Changeover had been difficult for 25%, only a nuisance for 49% and easy for 26%. The patients' lives were not endangered by conversion.

Tensile properties of HK31XA-H24 magnesium-alloy sheet under rapid-heating conditions and constant elevated temperatures

NASA Technical Reports Server (NTRS)

Gibbs, Thomas W

1956-01-01

Specimens of HK31XA-H24 magnesium-alloy sheet from an experimental batch were heated to failure at nominal temperature rates from 0.2 F to 100 F per second under constant-load conditions. Rapid-heating yield and rupture stresses are presented and compared with the yield and ultimate stresses from elevated-temperature tensile stress-strain tests for 1/2-hour exposure. Linear temperature-rate parameters were used to correlate rapid-heating results by constructing master curves which can be used for predicting yield stresses and temperatures and for estimating rupture stresses and temperatures.

Flexural creep behaviour of jute polypropylene composites

NASA Astrophysics Data System (ADS)

Chandekar, Harichandra; Chaudhari, Vikas

2016-09-01

Present study is about the flexural creep behaviour of jute fabric reinforced polypropylene (Jute-PP) composites. The PP sheet and alkali treated jute fabric is stacked alternately and hot pressed in compression molding machine to get Jute-PP composite laminate. The flexural creep study is carried out on dynamic mechanical analyzer. The creep behaviour of the composite is modeled using four-parameter Burgers model. Short-term accelerated creep testing is conducted which is later used to predict long term creep behaviour. The feasibility of the construction of a master curve using the time-temperature superposition (TTS) principle to predict long term creep behavior of unreinforced PP and Jute-PP composite is investigated.

Development of a StandAlone Surgical Haptic Arm.

PubMed

Jones, Daniel; Lewis, Andrew; Fischer, Gregory S

2011-01-01

When performing telesurgery with current commercially available Minimally Invasive Robotic Surgery (MIRS) systems, a surgeon cannot feel the tool interactions that are inherent in traditional laparoscopy. It is proposed that haptic feedback in the control of MIRS systems could improve the speed, safety and learning curve of robotic surgery. To test this hypothesis, a standalone surgical haptic arm (SASHA) capable of manipulating da Vinci tools has been designed and fabricated with the additional ability of providing information for haptic feedback. This arm was developed as a research platform for developing and evaluating approaches to telesurgery, including various haptic mappings between master and slave and evaluating the effects of latency.

Viscoelastic properties of elastomeric materials for O-ring applications

NASA Technical Reports Server (NTRS)

Bower, Mark V.

1989-01-01

Redesign of the Space Shuttle Solid Rocket Booster necessitated re-evaluation of the material used in the field joint O-ring seals. This research project was established to determine the viscoelastic characteristics of five candidate materials. The five materials are: two fluorocarbon compounds, two nitrile compounds, and a silicon compound. The materials were tested in a uniaxial compression test to determine the characteristic relaxation functions. These tests were performed at five different temperatures. A master material curve was developed for each material from the experimental data. The results of this study are compared to tensile relaxation tests. Application of these results to the design analysis is discussed in detail.

Micromaths: Removing Euclid from the Shackles.

ERIC Educational Resources Information Center

Oldknow, Adrian

2000-01-01

Attempts to lay the groundwork for a study of curves produced as loci using dynamic geometry. Provides some sketches of ways Cabri may be used to enhance the teaching of geometry with particular reference to synthetic plane Euclidean geometry, locus, and the conics. (Contains 26 references.) (ASK)

Liver Rapid Reference Set Application (#1): David Lubman - Univ of Michigan (2009) — EDRN Public Portal

Cancer.gov

We are requesting the reference set, which includes 50 HCC cases and 50 cirrhotic controls. In our preliminary study, AFP had a AUROC of 0.66 while the AUROC for the 5 glycoproteins was 0.81. The sensitivity and specificity for the 5 glycoproteins was 79% and 72% at the point that maximizes sensitivity+specificity in the ROC curve, and it was 79% and 35%, respectively, for AFP at the same point in the ROC curve. The reference set will allow us to determine the best performance of the 5 glycoproteins by themselves or whether their combination has a better sensitivity and/or specificity and AUROC. While a direct comparison with AFP will be made, the reference set will not allow a robust comparison due to the low sample size. If the glycoproteins are complementary or have better performance than AFP, then the next step would be to test them in the entire phase 2 hepatocellular carcinoma set.

Liver Rapid Reference Set Application ( #2): Lubman - Univ of Michigan (2010) — EDRN Public Portal

Cancer.gov

We are requesting the reference set, which includes 50 HCC cases and 50 cirrhotic controls. In our preliminary study, AFP had a AUROC of 0.66 while the AUROC for the 5 glycoproteins was 0.81. The sensitivity and specificity for the 5 glycoproteins was 79% and 72% at the point that maximizes sensitivity+specificity in the ROC curve, and it was 79% and 35%, respectively, for AFP at the same point in the ROC curve. The reference set will allow us to determine the best performance of the 5 glycoproteins by themselves or whether their combination has a better sensitivity and/or specificity and AUROC. While a direct comparison with AFP will be made, the reference set will not allow a robust comparison due to the low sample size. If the glycoproteins are complementary or have better performance than AFP, then the next step would be to test them in the entire phase 2 hepatocellular carcinoma set.

Reference values for the muscle power sprint test in 6- to 12-year-old children.

PubMed

Douma-van Riet, Danielle; Verschuren, Olaf; Jelsma, Dorothee; Kruitwagen, Cas; Smits-Engelsman, Bouwien; Takken, Tim

2012-01-01

The aims of this study were (1) to develop centile reference values for anaerobic performance of Dutch children tested using the Muscle Power Sprint Test (MPST) and (2) to examine the test-retest reliability of the MPST. Children who were developing typically (178 boys and 201 girls) and aged 6 to 12 years (mean = 8.9 years) were recruited. The MPST was administered to 379 children, and test-retest reliability was examined in 47 children. MPST scores were transformed into centile curves, which were created using generalized additive models for location, scale, and shape. Height-related reference curves were created for both genders. Excellent (intraclass correlation coefficient = 0.98) test-retest reliability was demonstrated. The reference values for the MPST of children who are developing typically and aged 6 to 12 years can serve as a clinical standard in pediatric physical therapy practice. The MPST is a reliable and practical method for determining anaerobic performance in children.

Application of Control Theory in the Formation of a Timescale

DTIC Science & Technology

2004-09-01

York). [3] P. Koppang and R. Leland , 1999, “Linear quadratic stochastic control of atomic hydrogen masers,” IEEE Transactions on Ultrasonics... Koppang , D. Johns, and J. Skinner U.S. Naval Observatory Abstract We have created a timescale that joins the short-term stability of...comparison. REFERENCES [1] D. Matsakis, M. Miranian, and P. Koppang , 1999, “Steering the U.S. Naval Observatory (USNO) Master Clock,” in

Yugoslavia: Implications of an Unjust War

DTIC Science & Technology

2008-03-15

Chomsky offers insight into this issue through reference to Woodrow Wilson’s admonitions: “The masters of the government of the United States are the...and disregard of international law. This paper has argued, as Noam Chomsky and many others have, that “the gap between professional ideals of just...for its own actions. 3 Noam Chomsky is an American linguist, philosopher, political activist, author and lecturer. He is a professor emeritus of

Costs and Benefits of Software Process Improvement

DTIC Science & Technology

1997-12-01

Washington, DC 20503. 1. AGENCY USE ONLY ( Leave blank) 2. REPORT DATE December 1997 3. REPORT TYPE AND DATES COVERED Master’s Thesis 4...in this field, an organization’s chance for success depends first on having an exceptional manager and an effective development team (PEOPLE...Secondly, it depends on its effective use of TECHNOLOGY, and finally, on its PROCESS maturity. [Ref. 4] In a software organization: PEOPLE refers to

Start Your Search Engines. Part One: Taming Google--and Other Tips to Master Web Searches

ERIC Educational Resources Information Center

Adam, Anna; Mowers, Helen

2008-01-01

There are a lot of useful tools on the Web, all those social applications, and the like. Still most people go online for one thing--to perform a basic search. For most fact-finding missions, the Web is there. But--as media specialists well know--the sheer wealth of online information can hamper efforts to focus on a few reliable references.…

Check Firing of Master and Reference Propellants

DTIC Science & Technology

2014-12-08

estimate amount and color of smoke generated. s. Visually estimate amount and color of muzzle flash generated. TOP 04-2-607A 8 December 2014 10...Stargauge. TOP 04-2-607A 8 December 2014 3 e. Pressure gauge (piezoelectric preferred, and/or crusher). f. Muzzle velocity radar unit...firing: a. Provide electronics personnel with the weapon caliber and type, the weight and model of projectile, and expected muzzle velocities. b

Giovanni Schiaparelli: Visions of a colour blind astronomer

NASA Astrophysics Data System (ADS)

Sheehan, W.

1997-02-01

The greatest observer of Mars of the nineteenth century was the Italian astronomer Giovanni Virginio Schiaparelli. In his classic compilation of Martian observations, La Planete Mars, published in 1892, Camille Flammarion readily conceded that Schiaparelli's was 'the greatest work which has been carried out with regard to Mars,'1 while another eminent Martian, Percival Lowell, referred to the Italian astronomer alone as his Martian master ('cher maitre Martien').

A height-for-age growth reference for children with achondroplasia: Expanded applications and comparison with original reference data.

PubMed

Hoover-Fong, Julie; McGready, John; Schulze, Kerry; Alade, Adekemi Yewande; Scott, Charles I

2017-05-01

The height-for-age (HA) reference currently used for children with achondroplasia is not adaptable for electronic records or calculation of HA Z-scores. We report new HA curves and tables of mean and standard deviation (SD) HA, for calculating Z-scores, from birth-16 years in achondroplasia. Mixed longitudinal data were abstracted from medical records of achondroplasia patients from a single clinical practice (CIS, 1967-2004). Gender-specific height percentiles (5, 25, 50, 75, 95th) were estimated across the age continuum, using a 2 month window per time point smoothed by a quadratic smoothing algorithm. HA curves were constructed for 0-36 months and 2-16 years to optimize resolution for younger children. Mean monthly height (SD) was tabulated. These novel HA curves were compared to reference data currently in use for children with achondroplasia. 293 subjects (162 male/131 female) contributed 1,005 and 932 height measures, with greater data paucity with age. Mean HA tracked with original achondroplasia norms, particularly through mid-childhood (2-9 years), but with no evidence of a pubertal growth spurt. Standard deviation of height at each month interval increased from birth through 16 years. Birth length was lower in achondroplasia than average stature and, as expected, height deficits increased with age. A new HA reference is available for longitudinal growth assessment in achondroplasia, taking advantage of statistical modeling techniques and allowing for Z-score calculations. This is an important contribution to clinical care and research endeavors for the achondroplasia population. © 2017 Wiley Periodicals, Inc.

Slot scanning versus antiscatter grid in digital mammography: comparison of low-contrast performance using contrast-detail measurement

NASA Astrophysics Data System (ADS)

Lai, Chao-Jen; Shaw, Chris C.; Geiser, William; Kappadath, Srinivas C.; Liu, Xinming; Wang, TianPeng; Tu, Shu-Ju; Altunbas, Mustafa C.

2004-05-01

Slot scanning imaging techniques allow for effective scatter rejection without attenuating primary x-rays. The use of these techniques should generate better image quality for the same mean glandular dose (MGD) or a similar image quality for a lower MGD as compared to imaging techniques using an anti-scatter grid. In this study, we compared a slot scanning digital mammography system (SenoScan, Fisher Imaging Systems, Denver, CO) to a full-field digital mammography (FFDM) system used in conjunction with a 5:1 anti-scatter grid (SenoGraphe 2000D, General Electric Medical Systems, Milwaukee, WI). Images of a contrast-detail phantom (University Hospital Nijmegen, The Netherlands) were reviewed to measure the contrast-detail curves for both systems. These curves were measured at 100%, 71%, 49% and 33% of the reference mean glandular dose (MGD), as determined by photo-timing, for the Fisher system and 100% for the GE system. Soft-copy reading was performed on review workstations provided by the manufacturers. The correct observation ratios (CORs) were also computed and used to compare the performance of the two systems. The results showed that, based on the contrast-detail curves, the performance of the Fisher images, acquired at 100% and 71% of the reference MGD, was comparable to the GE images at 100% of the reference MGD. The CORs for Fisher images were 0.463 and 0.444 at 100% and 71% of the reference MGD, respectively, compared to 0.453 for the GE images at 100% of the reference MGD.

Physical Growth of the Shuar: Height, Weight, and BMI References for an Indigenous Amazonian Population

PubMed Central

URLACHER, SAMUEL S.; BLACKWELL, AARON D.; LIEBERT, MELISSA A.; MADIMENOS, FELICIA C.; CEPON-ROBINS, TARA J.; GILDNER, THERESA E.; SNODGRASS, J. JOSH; SUGIYAMA, LAWRENCE S.

2015-01-01

Objectives Information concerning physical growth among small-scale populations remains limited, yet such data are critical to local health efforts and to foster basic understandings of human life history and variation in childhood development. Using a large dataset and robust modeling methods, this study aims to describe growth from birth to adulthood among the indigenous Shuar of Amazonian Ecuador. Methods Mixed-longitudinal measures of height, weight, and BMI were collected from Shuar participants (n = 2,463; age 0–29 years). Centile growth curves and tables were created for each anthropometric variable of interest using GAMLSS. Pseudo-velocity and LMS curves were generated to further investigate Shuar patterns of growth and to facilitate comparison with U.S. CDC and multinational WHO growth references. Results The Shuar are small throughout life and exhibit complex patterns of growth that differ substantially from those of international references. Similar to other Amazonians, Shuar growth in weight compares more favorably to references than growth in height, resulting in BMI curves that approximate international medians. Several additional characteristics of Shuar development are noteworthy, including large observed variation in body size early in life, significant infant growth faltering, extended male growth into adulthood, and a markedly early female pubertal growth spurt in height. Phenotypic plasticity and genetic selection in response to local environmental factors may explain many of these patterns. Conclusions Providing a detailed reference of growth for the Shuar and other Amazonian populations, this study possesses direct clinical application and affords valuable insight into childhood health and the ecology of human growth. PMID:26126793

Accuracy of body mass index for age to diagnose obesity in Mexican schoolchildren.

PubMed

Mendoza Pablo, Pedro A; Valdés, Jesús; Ortiz-Hernández, Luis

2015-06-01

To compare the accuracy of three BMI-forage references (World Health Organization reference, WHO; the updated International Obesity Task Force reference, IOTF; and Centers for Disease Control and Prevention (CDC) growth charts) to diagnose obesity in Mexican children. A convenience sample of Mexican schoolchildren (n = 218) was assessed. The gold standard was the percentage of body fat estimated by deuterium dilution technique. Sensitivity and specificity of the classical cutoff point of BMI-for-age to identify obesity (i.e. > 2.00 standard deviation, SD) were estimated. The accuracy (i.e. area under the curve, AUC) of three BMI-for-age references for the diagnosis of obesity was estimated with the receiver operating characteristic (ROC) curves method. The optimal cutoff point (OCP) was determined. The cutoff points to identify obesity had low (WHO reference: 57.6%, CDC: 53.5%) to very low (IOTF reference: 40.4%) sensitivities, but adequate specificities (91.6%, 95.0%, and, 97.5%, respectively). The AUC of the three references were adequate (0.89). For the IOTF reference, the AUC was lower among the older children. The OCP for the CDC reference (1.24 SD) was lower than the OCP for WHO (1.53 SD) and IOTF charts (1.47 SD). The classical cutoff point for obesity has low sensitivity--especially for the IOTF reference. The accuracy of the three references was similar. However, to obtain comparable diagnosis of obesity different cutoff points should be used depending of the reference. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Unemployment Rates and Starting Salaries: Are Australian Graduates at the Whim of the Wage Curve?

ERIC Educational Resources Information Center

Carroll, David

2011-01-01

The existence of an inverse relationship between wage levels and regional unemployment rates, commonly referred to as the wage curve, is well established in the economic literature and was described by Card (1995) as being "close to an empirical law of economics". This microeconomic wage-unemployment relationship, first identified by…

Practical Capillary Electrophoresis, 2nd Edition by Robert Weinberger

NASA Astrophysics Data System (ADS)

Tilstra, Luanne

2001-01-01

Parts of the text are unnecessarily confusing. The confusion arises because the author assumes the reader knows some aspect of CE in detail, although the detail is not presented until a later chapter. The "Master Symbol List" in the early pages is complete for individuals who are fluent in the language of CE, but not necessarily for folks new to the field. When faced with a new abbreviation, I found it necessary to check for its presence in the master list; if the abbreviation wasn't there, I added it. For example, every CE practitioner knows that BGE stands for "background electrolyte". Although the abbreviation was clearly defined in Chapter 1, I had forgotten it by the time I got to Chapter 3. Nevertheless, the wealth of detailed information, the abundance of useful references, and the well-organized tables outweigh the few editorial problems I found.

Mastering energy to avoid drama in your healthcare practice.

PubMed

Chism, Marlene

2012-01-01

Energy takes on many meanings depending on the context, but for the purposes of the workplace, I refer to energy as the force that serves to either propel us to greater purposes or destroy us with our drama. As it relates to the healthcare setting, our energy can help us serve our patients well, manage our staff with utmost clarity and civility, and nurture an environment of impeccable customer service. Or if not mastered properly, it can trigger workplace bullying, disruptive behavior, physical burnout, or, in short-drama. With literally hundreds of scientific studies, white papers, and expert reports on how fatigue leads to serious accidents and death, it seems we are still in denial about the impact of fatigue on patient safety and employee safety and well-being. Before we can address drama issues, we must first make a commitment to support policies and a culture that preserves the physical energy of those we manage.

ArcCN-Runoff: An ArcGIS tool for generating curve number and runoff maps

USGS Publications Warehouse

Zhan, X.; Huang, M.-L.

2004-01-01

The development and the application of ArcCN-Runoff tool, an extension of ESRI@ ArcGIS software, are reported. This tool can be applied to determine curve numbers and to calculate runoff or infiltration for a rainfall event in a watershed. Implementation of GIS techniques such as dissolving, intersecting, and a curve-number reference table improve efficiency. Technical processing time may be reduced from days, if not weeks, to hours for producing spatially varied curve number and runoff maps. An application example for a watershed in Lyon County and Osage County, Kansas, USA, is presented. ?? 2004 Elsevier Ltd. All rights reserved.

Peeling behavior and spalling resistance of CFRP sheets bonded to bent concrete surfaces

NASA Astrophysics Data System (ADS)

Yuan, Hong; Li, Faping

2010-05-01

In this paper, the peeling behavior and the spalling resistance effect of carbon fiber reinforced polymer (CFRP) sheets externally bonded to bent concrete surfaces are firstly investigated experimentally. Twenty one curved specimens and seven plane specimens are studied in the paper, in which curved specimens with bonded CFRP sheets can simulate the concrete spalling in tunnel, culvert, arch bridge etc., whereas plane specimens with bonded CFRP sheets can simulate the concrete spalling in beam bridge, slab bridge and pedestrian bridge. Three kinds of curved specimens with different radii of curvature are chosen by referring to practical tunnel structures, and plane specimens are used for comparison with curved ones. A peeling load is applied on the FRP sheet by loading a circular steel tube placed into the central notch of beam to debond CFRP sheets from the bent concrete surface, meanwhile full-range load-deflection curves are recorded by a MTS 831.10 Elastomer Test System. Based on the experimental results, a theoretical analysis is also conducted for the specimens. Both theoretical and experimental results show that only two material parameters, the interfacial fracture energy of CFRP-concrete interface and the tensile stiffness of CFRP sheets, are needed for describing the interfacial spalling behavior. It is found that the radius of curvature has remarkable influence on peeling load-deflection curves. The test methods and test results given in the paper are helpful and available for reference to the designer of tunnel strengthening.

Upper arm circumference development in Chinese children and adolescents: a pooled analysis.

PubMed

Tong, Fang; Fu, Tong

2015-05-30

Upper arm development in children is different in different ethnic groups. There have been few reports on upper arm circumference (UAC) at different stages of development in children and adolescents in China. The purpose of this study was to provide a reference for growth with weighted assessment of the overall level of development. Using a pooled analysis, an authoritative journal database search and reports of UAC, we created a new database on developmental measures in children. In conducting a weighted analysis, we compared reference values for 0~60 months of development according to the World Health Organization (WHO) statistics considering gender and nationality and used Z values as interval values for the second sampling to obtain an exponential smooth curve to analyze the mean, standard deviation, and sites of attachment. Ten articles were included in the pooled analysis, and these articles included participants from different areas of China. The point of intersection with the WHO curve was 3.5 years with higher values at earlier ages and lower values at older ages. Boys curve was steeper after puberty. The curves in the studies had a merged line compatible. The Z values of exponential smoothing showed the curves were similar for body weight and had a right normal distribution. The integrated index of UAC in Chinese children and adolescents indicated slightly variations with regions. Exponential curve smoothing was suitable for assessment at different developmental stages.

Pursuit Eye-Movements in Curve Driving Differentiate between Future Path and Tangent Point Models

PubMed Central

Lappi, Otto; Pekkanen, Jami; Itkonen, Teemu H.

2013-01-01

For nearly 20 years, looking at the tangent point on the road edge has been prominent in models of visual orientation in curve driving. It is the most common interpretation of the commonly observed pattern of car drivers looking through a bend, or at the apex of the curve. Indeed, in the visual science literature, visual orientation towards the inside of a bend has become known as “tangent point orientation”. Yet, it remains to be empirically established whether it is the tangent point the drivers are looking at, or whether some other reference point on the road surface, or several reference points, are being targeted in addition to, or instead of, the tangent point. Recently discovered optokinetic pursuit eye-movements during curve driving can provide complementary evidence over and above traditional gaze-position measures. This paper presents the first detailed quantitative analysis of pursuit eye movements elicited by curvilinear optic flow in real driving. The data implicates the far zone beyond the tangent point as an important gaze target area during steady-state cornering. This is in line with the future path steering models, but difficult to reconcile with any pure tangent point steering model. We conclude that the tangent point steering models do not provide a general explanation of eye movement and steering during a curve driving sequence and cannot be considered uncritically as the default interpretation when the gaze position distribution is observed to be situated in the region of the curve apex. PMID:23894300

Effective use of outcomes data in cardiovascular surgery

NASA Astrophysics Data System (ADS)

Yasnoff, William A.; Page, U. S.

1994-12-01

We have established the Merged Cardiac Registry (MCR) containing over 100,000 cardiovascular surgery cases from 47 sites in the U.S. and Europe. MCR outcomes data are used by the contributors for clinical quality improvement. A tool for prospective prediction of mortality and stroke for coronary artery bypass graft surgery (83% of the cases), known as RiskMaster, has been developed using a Bayesian model based on 40,819 patients who had their surgery from 1988-92, and tested on 4,244 patients from 1993. In patients with mortality risks of 10% or less (92% of cases), the average risk prediction is identical to the actual 30- day mortality (p > 0.37), while risk is overestimated in higher risk patients. The receiver operating characteristic curve area for mortality prediction is 0.76 +/- 0.02. The RiskMaster prediction tool is now available online or as a standalone software package. MCR data also shows that average mortality risk is identical for a given body surface area regardless of gender. Outcomes data measure the benefits of health care, and are therefore an essential element in cost/benefit analysis. We believe their cost is justified by their use for the rational assessment of treatment alternatives.

How to establish endoscopic submucosal dissection in Western countries.

PubMed

Oyama, Tsuneo; Yahagi, Naohisa; Ponchon, Thierry; Kiesslich, Tobias; Berr, Frieder

2015-10-28

Endoscopic submucosal dissection (ESD) has been invented in Japan to provide resection for cure of early cancer in the gastrointestinal tract. Professional level of ESD requires excellent staging of early neoplasias with image enhanced endoscopy (IEE) to make correct indications for ESD, and high skills in endoscopic electrosurgical dissection. In Japan, endodiagnostic and endosurgical excellence spread through personal tutoring of skilled endoscopists by the inventors and experts in IEE and ESD. To translocate this expertise to other continents must overcome two fundamental obstacles: (1) inadequate expectations as to the complexity of IEE and ESD; and (2) lack of suitable lesions and master-mentors for ESD trainees. Leading endoscopic mucosal resection-proficient endoscopists must pioneer themselves through the long learning curve to proficient ESD experts. Major referral centers for ESD must arise in Western countries on comparable professional level as in Japan. In the second stage, the upcoming Western experts must commit themselves to teach skilled endoscopists from other referral centers, in order to spread ESD in Western countries. Respect for patients with early gastrointestinal cancer asks for best efforts to learn endoscopic categorization of early neoplasias and skills for ESD based on sustained cooperation with the masters in Japan. The strategy is discussed here.

Growth charts for Australian children with achondroplasia.

PubMed

Tofts, Louise; Das, Sandeep; Collins, Felicity; Burton, Karen L O

2017-08-01

Achondroplasia is an autosomal dominant disorder, the most common genetic cause of short stature in humans. Reference curves for head circumference, weight, height, and BMI are needed in clinical practice but none exist for the Australian population. This study aimed to produce head circumference, height, weight, and BMI reference percentile curves for Australian children and adolescents with achondroplasia. Measurements of head circumference, height and weight taken at clinical visits were retrospectively extracted from the electronic medical record. Age was corrected for prematurity. Patients were excluded from head circumference analysis if they had significant neurosurgical complications and from the weight and BMI analysis when they had a clinical diagnosis of overweight. Measurements were available on 138 individuals (69 males and 69 females) taken between 1970 and 2015, with over 50% collected since 2005. A total of 3,352 data points were available. The LMS method was used to produce growth charts with estimated centiles (10, 25, 50, 75, and 90th) separately for males and females. For females birth weight was 3 kg (2.5-3.5 kg), birth length 48 cm (44-50 cm) and head circumference 37.5 cm (36-39 cm), adult height was 125 cm (116-132 cm), weight 42 kg (34-54 kg), and head circumference 58 cm (55.5-60.5 cm) all 50th centile (10-90th). For males birth weight was 3.5 kg (3-4 kg), length 49 cm (46-52 cm) and head circumference 38.5 cm (36-41 cm), adult height was 134 cm (125-141 cm), weight 41 kg (24.5-57 kg) and head circumference 61 cm (58-64 cm). The curves are similar to previously published reference data from the USA and have expected population wide variation from curves from an Argentinian population. Despite limitations of our curves for adolescents (12 years and older) due to data paucity, these Australian growth charts for children and adolescents with achondroplasia will be a useful reference in clinical practice. © 2017 Wiley Periodicals, Inc.

Acid precipitation; an annotated bibliography

USGS Publications Warehouse

Wiltshire, Denise A.; Evans, Margaret L.

1984-01-01

This collection of 1660 bibliographies references on the causes and environmental effects of acidic atmospheric deposition was compiled from computerized literature searches of earth-science and chemistry data bases. Categories of information are (1) atmospheric chemistry (gases and aerosols), (2) precipitation chemistry, (3) transport and deposition (wet and dry), (4) aquatic environments (biological and hydrological), (5) terrestrial environments, (6) effects on materials and structures, (7) air and precipitation monitoring and data collection, and (8) modeling studies. References date from the late 1800 's through December 1981. The bibliography includes short summaries of most documents. Omitted are unpublished manuscripts, publications in press, master 's theses and doctoral dissertations, newspaper articles, and book reviews. Coauthors and subject indexes are included. (USGS)

Productivity Measurement in Research and Development Laboratories.

DTIC Science & Technology

1981-09-01

identified by Szilagyi and Wallace (67:447-453), because these concepts "refer to the adequacy of the information that is generated and employed in...specified time period. Quantitative terms are used to ex- press qualitative judgments. Szilagyi and Wallace (66:457-458) further expand on the...Scientists/Engineers." Unpublished master’s thesis, GSM/SM/76D-36, Wright-Patterson AFB OH, December 1976. ADA 036462. 67. Szilagyi , Andrew D. Jr., and Marc

1969 MLA International Bibliography of Books and Articles on the Modern Languages and Literatures. Volume I: General, English, American, Medieval and Neo-Latin, and Celtic Literatures.

ERIC Educational Resources Information Center

Meserole, Harrison T., Comp.

Volume 1 of the 4-volume, international bibliography contains some 9,000 entries referring to books and articles which focus on general, English, American, medieval and neo-Latin, and Celtic literatures. The master list of the nearly 1,500 periodicals from which entries are derived is furnished at the beginning of the volume with a table of…

Intelligence and Electronic Warfare (IEW) Streamlining Project. Volume 3. Reference Documentation (Part 5)

DTIC Science & Technology

1992-11-18

Army. He is a graduate of Henderson State Univer- sity, Arkadelphia, Arkansas, and holds a master ofspend on financial management controls. Asset...supply system, he will receive credit receipts, and making monthly reconciliations with from the tactical unit financial management infor- activi ies at...obtain financial management rather than being added to the daily batch of requests information, and provide supply status information passed to the direct

CMR Catalog Service for the Web

NASA Technical Reports Server (NTRS)

Newman, Doug; Mitchell, Andrew

2016-01-01

With the impending retirement of Global Change Master Directory (GCMD) Application Programming Interfaces (APIs) the Common Metadata Repository (CMR) was charged with providing a collection-level Catalog Service for the Web (CSW) that provided the same level of functionality as GCMD. This talk describes the capabilities of the CMR CSW API with particular reference to the support of the Committee on Earth Observation Satellites (CEOS) Working Group on Information Systems and Services (WGISS) Integrated Catalog (CWIC).

Methodology for Constructing a Modernization Roadmap for Air Force Automatic Test Systems

DTIC Science & Technology

2012-01-01

Constructing a Modernization Roadmap for Air Force Automatic Test Systems Lionel A. Galway , Rachel Rue, James M. Masters, Ben D. Van Roo, Manuel...constructing a modernization roadmap for Air Force automatic test systems / Lionel A. Galway ... [et al.]. p. cm. Includes bibliographical...references. ISBN 978-0-8330-5899-7 (pbk. : alk. paper) 1. United States. Air Force—Weapons systems—Testing. I. Galway , Lionel A., 1950- UG633.M3445

The In-Flight Frequency Behavior of Two Ultra-Stable Oscillators Onboard the New Horizons Spacecraft

DTIC Science & Technology

2007-11-01

the other is maintained in a “warm-boot” backup mode. The implementation of the transceiver for noncoherent navigation provides the opportunity for...frequency reference for the REX (Radio science Experiment) instrument and the master oscillator for the communications transceiver and the noncoherent ...byproduct of noncoherent Doppler based 79 Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection of information

The Application of a Statistical Analysis Software Package to Explosive Testing

DTIC Science & Technology

1993-12-01

deviation not corrected for test interval. M refer to equation 2. s refer to equation 3. G refer to section 2.1, C 36 Appendix I : Program Structured ...APPENDIX I: Program Structured Diagrams 37 APPENDIX II: Bruceton Reference Graphs 39 APPENDIX III: Input and Output Data File Format 44 APPENDIX IV...directly from Graph II, which has been digitised and incorporated into the program . IfM falls below 0.3, the curve that is closest to diff( eq . 3a) is

Wind-Tunnel Tests of Single- and Dual-Rotating Pusher Propellers Having from Three to Eight Blades

DTIC Science & Technology

1942-02-01

propellor, dual rotation ch.arnctorlstic curves for elx-blade propollor, sin~lo rotnt%on -charnctoristlc curves for six-l) lado propollor, (dual...results of the “pusher tests are in general agreo- “ment“with” the traetior “tests previously Feportsd (refer- ences 1 End 2) a,e regarde the effect of

The New Sun-Sky-Lunar Cimel CE318-T Multiband Photometer - A Comprehensive Performance Evaluation

NASA Technical Reports Server (NTRS)

Barreto, Africa; Cuevas, Emilio; Granados-Munoz, Maria-Jose; Alados-Arboledas, Lucas; Romero, Pedro M.; Grobner, Julian; Kouremeti, Natalia; Almansa, Antonio F.; Stone, Tom; Toledano, Carlos;

47 CFR 80.767 - Propagation curve.

Code of Federal Regulations, 2012 CFR

2012-10-01

... data for field strengths in dBu for an effective radiated power of 1 kW, over sea water, fresh water or... referred to 1 kW (dBk), as follows: EC02AP91.005 where, Pt=Transmitter output power in dB referred to 1 kW... Graph 1 for a conversion graph. G=Antenna gain in dB referred to a standard half-wave dipole, in the...

47 CFR 80.767 - Propagation curve.

Code of Federal Regulations, 2014 CFR

2014-10-01

... data for field strengths in dBu for an effective radiated power of 1 kW, over sea water, fresh water or... referred to 1 kW (dBk), as follows: EC02AP91.005 where, Pt=Transmitter output power in dB referred to 1 kW... Graph 1 for a conversion graph. G=Antenna gain in dB referred to a standard half-wave dipole, in the...

47 CFR 80.767 - Propagation curve.

Code of Federal Regulations, 2011 CFR

2011-10-01

... data for field strengths in dBu for an effective radiated power of 1 kW, over sea water, fresh water or... referred to 1 kW (dBk), as follows: EC02AP91.005 where, Pt=Transmitter output power in dB referred to 1 kW... Graph 1 for a conversion graph. G=Antenna gain in dB referred to a standard half-wave dipole, in the...

47 CFR 80.767 - Propagation curve.

Code of Federal Regulations, 2013 CFR

2013-10-01

... data for field strengths in dBu for an effective radiated power of 1 kW, over sea water, fresh water or... referred to 1 kW (dBk), as follows: EC02AP91.005 where, Pt=Transmitter output power in dB referred to 1 kW... Graph 1 for a conversion graph. G=Antenna gain in dB referred to a standard half-wave dipole, in the...

Solid-state curved focal plane arrays

NASA Technical Reports Server (NTRS)

Jones, Todd (Inventor); Nikzad, Shouleh (Inventor); Hoenk, Michael (Inventor)

2010-01-01

The present invention relates to curved focal plane arrays. More specifically, the present invention relates to a system and method for making solid-state curved focal plane arrays from standard and high-purity devices that may be matched to a given optical system. There are two ways to make a curved focal plane arrays starting with the fully fabricated device. One way, is to thin the device and conform it to a curvature. A second way, is to back-illuminate a thick device without making a thinned membrane. The thick device is a special class of devices; for example devices fabricated with high purity silicon. One surface of the device (the non VLSI fabricated surface, also referred to as the back surface) can be polished to form a curved surface.

Application of curve resolution algorithms in the study of drug photodegradation kinetics -- the example of moclobemide.

PubMed

Skibiński, Robert; Komsta, Łukasz

2012-01-01

The photodegradation of moclobemide was studied in methanolic media. Ultra-HPLC (UHPLC)/MS/MS analysis proved decomposition to 4-chlorobenzamide as a major degradation product and small amounts of Ro 16-3177 (4-chloro-N-[2-[(2-hydroxyethyl)amino] ethyl]benzamide) and 2-[(4-chlorobenzylidene)amino]-N-[2-ethoxyethenyl]ethenamine. The methanolic solution was investigated spectrophotometrically in the UV region, registering the spectra during 30 min of degradation. Using reference spectra and a multivariate chemometric method (multivariate curve resolution-alternating least squares), the spectra were resolved and concentration profiles were obtained. The obtained results were in good agreement with a quantitative approach, with UHPLC-diode array detection as the reference method.

Nutritional status and height, weight and BMI centiles of school-aged children and adolescents of 6-18-years from Kinshasa (DRC).

PubMed

Buhendwa, Rudahaba Augustin; Roelants, Mathieu; Thomis, Martine; Nkiama, Constant E

2017-09-01

The last study to establish centiles of main anthropometric measurements in Kinshasa was conducted over 60 years ago, which questions its current adequacy to describe or monitor growth in this population. To assess the nutritional status of school-aged children and adolescents and to estimate centile curves of height, weight and body mass index (BMI). A representative sample of 7541 school-aged children and adolescents (48% boys) aged 6-18 years was measured between 2010-2013. Smooth centiles of height, weight and BMI-for-age were estimated with the LMS method and compared with the WHO 2007 reference. Nutritional status was assessed by comparing measurements of height and BMI against the appropriate WHO cut-offs. Compared to the WHO reference, percentiles of height and BMI were generally lower. This difference was larger in boys than in girls and increased as they approached adolescence. The prevalence of short stature (< -2 SD) and thinness (< -2 SD) was higher in boys (9.8% and 12%) than in girls (3.4% and 6.1%), but the prevalence of overweight (> 1 SD) was higher in girls (8.6%) than in boys (4.5%). Children from Kinshasa fall below WHO centile references. This study established up-to-date centile curves for height, weight and BMI by age in children and adolescents. These reference curves describe the current status of these anthropometric markers and can be used as a basis for comparison in future studies.

Reference Standard Test and the Diagnostic Ability of Spectral Domain Optical Coherence Tomography in Glaucoma.

PubMed

Rao, Harsha L; Yadav, Ravi K; Addepalli, Uday K; Begum, Viquar U; Senthil, Sirisha; Choudhari, Nikhil S; Garudadri, Chandra S

2015-08-01

To evaluate the relationship between the reference standard used to diagnose glaucoma and the diagnostic ability of spectral domain optical coherence tomograph (SDOCT). In a cross-sectional study, 280 eyes of 175 consecutive subjects, referred to a tertiary eye care center for glaucoma evaluation, underwent optic disc photography, visual field (VF) examination, and SDOCT examination. The cohort was divided into glaucoma and control groups based on 3 reference standards for glaucoma diagnosis: first based on the optic disc classification (179 glaucoma and 101 control eyes), second on VF classification (glaucoma hemifield test outside normal limits and pattern SD with P-value of <5%, 130 glaucoma and 150 control eyes), and third on the presence of both glaucomatous optic disc and glaucomatous VF (125 glaucoma and 155 control eyes). Relationship between the reference standards and the diagnostic parameters of SDOCT were evaluated using areas under the receiver operating characteristic curve, sensitivity, and specificity. Areas under the receiver operating characteristic curve and sensitivities of most of the SDOCT parameters obtained with the 3 reference standards (ranging from 0.74 to 0.88 and 72% to 88%, respectively) were comparable (P>0.05). However, specificities of SDOCT parameters were significantly greater (P<0.05) with optic disc classification as reference standard (74% to 88%) compared with VF classification as reference standard (57% to 74%). Diagnostic parameters of SDOCT that was significantly affected by reference standard was the specificity, which was greater with optic disc classification as the reference standard. This has to be considered when comparing the diagnostic ability of SDOCT across studies.

Physical growth of the shuar: Height, Weight, and BMI references for an indigenous amazonian population.

PubMed

Urlacher, Samuel S; Blackwell, Aaron D; Liebert, Melissa A; Madimenos, Felicia C; Cepon-Robins, Tara J; Gildner, Theresa E; Snodgrass, J Josh; Sugiyama, Lawrence S

2016-01-01

Information concerning physical growth among small-scale populations remains limited, yet such data are critical to local health efforts and to foster basic understandings of human life history and variation in childhood development. Using a large dataset and robust modeling methods, this study aims to describe growth from birth to adulthood among the indigenous Shuar of Amazonian Ecuador. Mixed-longitudinal measures of height, weight, and body mass index (BMI) were collected from Shuar participants (n = 2,463; age: 0-29 years). Centile growth curves and tables were created for each anthropometric variable of interest using Generalized Additive Models for Location, Scale, and Shape (GAMLSS). Pseudo-velocity and Lambda-Mu-Sigma curves were generated to further investigate Shuar patterns of growth and to facilitate comparison with United States Center for Disease Control and Prevention and multinational World Health Organization growth references. The Shuar are small throughout life and exhibit complex patterns of growth that differ substantially from those of international references. Similar to other Amazonians, Shuar growth in weight compares more favorably to references than growth in height, resulting in BMI curves that approximate international medians. Several additional characteristics of Shuar development are noteworthy, including large observed variation in body size early in life, significant infant growth faltering, extended male growth into adulthood, and a markedly early female pubertal growth spurt in height. Phenotypic plasticity and genetic selection in response to local environmental factors may explain many of these patterns. Providing a detailed reference of growth for the Shuar and other Amazonian populations, this study possesses direct clinical application and affords valuable insight into childhood health and the ecology of human growth. © 2015 Wiley Periodicals, Inc.

On the validity of the dispersion model of hepatic drug elimination when intravascular transit time densities are long-tailed.

PubMed

Weiss, M; Stedtler, C; Roberts, M S

1997-09-01

The dispersion model with mixed boundary conditions uses a single parameter, the dispersion number, to describe the hepatic elimination of xenobiotics and endogenous substances. An implicit a priori assumption of the model is that the transit time density of intravascular indicators is approximately by an inverse Gaussian distribution. This approximation is limited in that the model poorly describes the tail part of the hepatic outflow curves of vascular indicators. A sum of two inverse Gaussian functions is proposed as an alternative, more flexible empirical model for transit time densities of vascular references. This model suggests that a more accurate description of the tail portion of vascular reference curves yields an elimination rate constant (or intrinsic clearance) which is 40% less than predicted by the dispersion model with mixed boundary conditions. The results emphasize the need to accurately describe outflow curves in using them as a basis for determining pharmacokinetic parameters using hepatic elimination models.

[Computer aided design for fixed partial denture framework based on reverse engineering technology].

PubMed

Sun, Yu-chun; Lü, Pei-jun; Wang, Yong

2006-03-01

To explore a computer aided design (CAD) route for the framework of domestic fixed partial denture (FPD) and confirm the suitable method of 3-D CAD. The working area of a dentition model was scanned with a 3-D mechanical scanner. Using the reverse engineering (RE) software, margin and border curves were extracted and several reference curves were created to ensure the dimension and location of pontic framework that was taken from the standard database. The shoulder parts of the retainers were created after axial surfaces constructed. The connecting areas, axial line and curving surface of the framework connector were finally created. The framework of a three-unit FPD was designed with RE technology, which showed smooth surfaces and continuous contours. The design route is practical. The result of this study is significant in theory and practice, which will provide a reference for establishing the computer aided design/computer aided manufacture (CAD/CAM) system of domestic FPD.

Information on the Advanced Plant Experiment (APEX) Test Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Curtis Lee

The purpose of this report provides information related to the design of the Oregon State University Advanced Plant Experiment (APEX) test facility. Information provided in this report have been pulled from the following information sources: Reference 1: R. Nourgaliev and et.al, "Summary Report on NGSAC (Next-Generation Safety Analysis Code) Development and Testing," Idaho National Laboratory, 2011. Note that this is report has not been released as an external report. Reference 2: O. Stevens, Characterization of the Advanced Plant Experiment (APEX) Passive Residual Heat Removal System Heat Exchanger, Master Thesis, June 1996. Reference 3: J. Reyes, Jr., Q. Wu, and J.more » King, Jr., Scaling Assessment for the Design of the OSU APEX-1000 Test Facility, OSU-APEX-03001 (Rev. 0), May 2003. Reference 4: J. Reyes et al, Final Report of the NRC AP600 Research Conducted at Oregon State University, NUREG/CR-6641, July 1999. Reference 5: K. Welter et al, APEX-1000 Confirmatory Testing to Support AP1000 Design Certification (non-proprietary), NUREG-1826, August 2005.« less

[Penis growth and development in children and adolescents: a study based on GAMLSS].

PubMed

Yi, Qing-Jie; Zeng, Yan; Zeng, Qing; Wang, Yi-Nan; Xiong, Feng

2017-08-01

To investigate penis development in children and adolescents aged 0-16 years, and to plot the percentile curve for penis development in different age groups. A total of 3 024 normal male neonates, children, and adolescents aged 0-16 years in Chongqing, China were selected by simple random sampling and stratified cluster sampling. The length and diameter of the penis were measured for all subjects. A descriptive statistical analysis was used to investigate the data characteristics of the penis, and the GAMLSS fitting model was used to plot the percentile curves of P 3 , P 10 , P 25 , P 50 , P 75 , P 90 , and P97 and obtain percentile reference values. The length and diameter of the penis grew rapidly before the age of 1 year, grew relatively slowly from 1 to 11 years old, and entered a rapid growth period from 11 years old. The length of the penis was positively correlated with its diameter (r=0.961, P<0.01). The percentile reference values of penis length and diameter were obtained and the percentile curve was plotted. The growth and development of penis length is consistent with that of penis diameter in male children and adolescents in Chongqing, and 0-1 year and 11-16 years are rapid growth periods of penis length and diameter. The percentile curve of penis length and diameter in children and adolescents aged 0-16 years in Chongqing which has been established will provide a reference for further studies on sexual development in children and adolescents.

Communication: Fast dynamics perspective on the breakdown of the Stokes-Einstein law in fragile glassformers

NASA Astrophysics Data System (ADS)

Puosi, F.; Pasturel, A.; Jakse, N.; Leporini, D.

2018-04-01

The breakdown of the Stokes-Einstein (SE) law in fragile glassformers is examined by Molecular-Dynamics simulations of atomic liquids and polymers and consideration of the experimental data concerning the archetypical ortho-terphenyl glassformer. All the four systems comply with the universal scaling between the viscosity (or the structural relaxation) and the Debye-Waller factor ⟨u2⟩, the mean square amplitude of the particle rattling in the cage formed by the surrounding neighbors. It is found that the SE breakdown is scaled in a master curve by a reduced ⟨u2⟩. Two approximated expressions of the latter, with no and one adjustable parameter, respectively, are derived.

Durability of base courses with mineral-cement-emulsion mixes (MCEM)

NASA Astrophysics Data System (ADS)

Kukiełka, J.; Sybilski, D.

2018-05-01

Base courses with mineral-cement-emulsion mixes (MCEM) have been the subject of research, surveys and development of e.g. new requirements included in the Guidelines of 2014 [15]. In this paper the results of sample test and survey of road sections, assessment of transverse cracks and load-bearing capacity with FWD after 13 years of exploitation are presented. On the MCEM samples the following tests were carried out: resilient modulus using NAT, complex stiffness modulus (E*), phase shift angle at various temperatures and loading frequencies thereby obtaining master curves, fatigue life and low-temperature resistance by identifying the tensile stress restrained (TSRST) which allowed for general assessment of constructed base courses.

Tensile properties of AZ11A-0 magnesium-alloy sheet under rapid-heating and constant temperature

NASA Technical Reports Server (NTRS)

Kurg, Ivo M

1956-01-01

Specimens of AZ31A-0 magnesium alloy sheet were heated to rupture at nominal rates of 0.2 F to 100 F per second under constant tensile load conditions. The data are presented and compared with the results of conventional tensile stress-strain tests at elevated temperatures after 1.2-hour exposure. A temperature-rate parameter was used to construct master curves from which stresses and temperatures for yield and rupture can be predicted under rapid-heating conditions. A comparison of the elevated-temperature tensile properties of AZ31A-0 and HK31XA-H24 magnesium-alloy sheet under both constant-temperature and rapid-heating conditions is included.

Impedance spectroscopic characterization of Sm2O3 containing lithium borate glasses.

PubMed

Ramteke, D D; Gedam, R S

2014-12-10

27.5 Li2O-(72.5-X) B2O3-X Sm2O3 (X=0.5, 1, 1.5 and 2) were prepared by conventional melt quench technique. Impedance spectroscopy (IS) is used to study the electrical properties of these prepared glasses. Modulus formalism is introduced to study relaxation behaviour of these glasses. Scaling model shows the good overlap of data on single master curve which suggests that conduction mechanism in these glasses is compositional dependent. Variation of dielectric constant and dielectric loss with the addition of Sm2O3 and frequency are discussed here. Copyright © 2014 Elsevier B.V. All rights reserved.

Modeling the Acceleration of Global Surface Temperture

NASA Astrophysics Data System (ADS)

Jones, B.

2017-12-01

A mathematical projection focusing on the changing rate of acceleration of Global Surface Temperatures. Using historical trajectory and informed expert near-term prediction, it is possible to extend this further forward drawing a reference arc of acceleration. Presented here is an example of this technique based on data found in the Summary of Findings of A New Estimate of the Average Earth Surface Land Temperature Spanning 1753 to 2011 and that same team's stated prediction to 2050. With this, we can project a curve showing future acceleration: Decade (midpoint) Change in Global Land Temp Degrees C Known Slope Projected Trend 1755 0.000 1955 0.600 0.0030 2005 1.500 0.0051 2045 3.000 0.0375 2095 5.485 0.0497 2145 8.895 0.0682 2195 13.488 0.0919 Observations: Slopes are getting steeper and doing so faster in an "acceleration of the acceleration" or an "arc of acceleration". This is consistent with the non-linear accelerating feedback loops of global warming. Such projected temperatures threaten human civilization and human life. This `thumbnail' projection is consistent with the other long term predictions based on anthropogenic greenhouse gases. This projection is low when compared to those whose forecasts include greenhouse gases released from thawing permafrost and clathrate hydrates. A reference line: This curve should be considered a point of reference. In the near term and absent significant drawdown of greenhouse gases, my "bet" for this AGU session is that future temperatures will generally be above this reference curve. For example, the decade ending 2020 - more than 1.9C and the decade ending 2030 - more than 2.3C - again measured from the 1750 start point. *Caveat: The long term curve and prediction assumes that mankind does not move quickly away from high cost fossil fuels and does not invent, mobilize and take actions drawing down greenhouse gases. Those seeking a comprehensive action plan are directed to drawdown.org

Technique Incorporating Cooling & Contraction / Expansion Analysis to Illustrate Shrinkage Tendency in Cast Irons

NASA Astrophysics Data System (ADS)

Stan, S.; Chisamera, M.; Riposan, I.; Neacsu, L.; Cojocaru, A. M.; Stan, I.

2017-06-01

With the more widespread adoption of thermal analysis testing, thermal analysis data have become an indicator of cast iron quality. The cooling curve and its first derivative display patterns that can be used to predict the characteristics of a cast iron. An experimental device was developed with a technique to simultaneously evaluate cooling curves and expansion or contraction of cast metals during solidification. Its application is illustrated with results on shrinkage tendency of ductile iron treated with FeSiMgRECa master alloy and inoculated with FeSi based alloys, as affected by mould rigidity (green sand and resin sand moulds). Undercooling at the end of solidification relative to the metastable (carbidic) equilibrium temperature and the expansion within the solidification sequence appear to have a strong influence on the susceptibility to macro - and micro - shrinkage in ductile iron castings. Green sand moulds, as less rigid moulds, encourage the formation of contraction defects, not only because of high initial expansion values, but also because of a higher cooling rate during solidification, and consequently, increased undercooling below the metastable equilibrium temperature up to the end of solidification.

Metamagnetism, sign reversal and low temperature magnetocaloric effect in single-crystalline EuV2Al20

NASA Astrophysics Data System (ADS)

Ramesh Kumar, K.; Nair, Harikrishnan S.; Bhattacharyya, A.; Thamizhavel, A.; Strydom, André M.

2018-04-01

The Frank-Kasper cage compound EuV2Al20 crystallizes in the cubic structure with Fd 3 ‾ m space group and exhibits unusual magnetic and transport properties. The system undergoes an antiferromagnetic transition below 5.6 K wherein the Eu2+ moments are aligned anti-parallel along 〈1 1 1〉 direction and the system exhibits a weak metamagetic transition at the field of 1 T. Arrott plots (M2 vs H / M) show a "S" shaped variation in the low fields below TN and the plausible reason for the occurrence of negative slope is discussed. Isothermal magnetic entropy change is estimated from both magnetization and heat capacity measurements invoking the Maxwell's thermodynamic relations. Temperature variation of ΔSm showed a weak negative minimum and a sign reversal at the field value of 1 T due to field induced metamagnetic transition. Universal master curve is constructed by rescaling the ΔSm vs T curves in the context of analysing the nature of the magnetic transition.

Dielectric behavior and AC conductivity of Cr doped α-Mn2O3

NASA Astrophysics Data System (ADS)

Chandra, Mohit; Yadav, Satish; Singh, K.

2018-05-01

The complex dielectric behavior of polycrystalline α-Mn2-xCrxO3 (x = 0.10) has been investigated isothermally at wide frequency range (4Hz-1 MHz) at different temperatures (300-390K). The dielectric spectroscopy results have been discussed in different formulism like dielectric constant, impedance and ac conductivity. The frequency dependent dielectric loss (tanδ) exhibit a clear relaxation behavior in the studied temperature range. The relaxation frequency increases with increasing temperature. These results are fitted using Arrhenius equation which suggest thermally activated process and the activation energy is 0.173±0.0024 eV. The normalized tanδ curves at different temperatures merge as a single master curve which indicate that the relaxation process follow the similar relaxation dynamics in the studied temperature range. Further, the dielectric relaxation follows non-Debye behavior. The impedance results inference that the grain boundary contribution dominate at lower frequency whereas grain contribution appeared at higher frequencies and exhibit strong temperature dependence. The ac conductivity data shows that the ac conductivity increases with increasing temperature which corroborate the semiconducting nature of the studied sample.

Universal scaling and nonlinearity of aggregate price impact in financial markets.

PubMed

Patzelt, Felix; Bouchaud, Jean-Philippe

2018-01-01

How and why stock prices move is a centuries-old question still not answered conclusively. More recently, attention shifted to higher frequencies, where trades are processed piecewise across different time scales. Here we reveal that price impact has a universal nonlinear shape for trades aggregated on any intraday scale. Its shape varies little across instruments, but drastically different master curves are obtained for order-volume and -sign impact. The scaling is largely determined by the relevant Hurst exponents. We further show that extreme order-flow imbalance is not associated with large returns. To the contrary, it is observed when the price is pinned to a particular level. Prices move only when there is sufficient balance in the local order flow. In fact, the probability that a trade changes the midprice falls to zero with increasing (absolute) order-sign bias along an arc-shaped curve for all intraday scales. Our findings challenge the widespread assumption of linear aggregate impact. They imply that market dynamics on all intraday time scales are shaped by correlations and bilateral adaptation in the flows of liquidity provision and taking.

Universal scaling and nonlinearity of aggregate price impact in financial markets

NASA Astrophysics Data System (ADS)

Patzelt, Felix; Bouchaud, Jean-Philippe

2018-01-01

How and why stock prices move is a centuries-old question still not answered conclusively. More recently, attention shifted to higher frequencies, where trades are processed piecewise across different time scales. Here we reveal that price impact has a universal nonlinear shape for trades aggregated on any intraday scale. Its shape varies little across instruments, but drastically different master curves are obtained for order-volume and -sign impact. The scaling is largely determined by the relevant Hurst exponents. We further show that extreme order-flow imbalance is not associated with large returns. To the contrary, it is observed when the price is pinned to a particular level. Prices move only when there is sufficient balance in the local order flow. In fact, the probability that a trade changes the midprice falls to zero with increasing (absolute) order-sign bias along an arc-shaped curve for all intraday scales. Our findings challenge the widespread assumption of linear aggregate impact. They imply that market dynamics on all intraday time scales are shaped by correlations and bilateral adaptation in the flows of liquidity provision and taking.

Nonlinear price impact from linear models

NASA Astrophysics Data System (ADS)

Patzelt, Felix; Bouchaud, Jean-Philippe

2017-12-01

The impact of trades on asset prices is a crucial aspect of market dynamics for academics, regulators, and practitioners alike. Recently, universal and highly nonlinear master curves were observed for price impacts aggregated on all intra-day scales (Patzelt and Bouchaud 2017 arXiv:1706.04163). Here we investigate how well these curves, their scaling, and the underlying return dynamics are captured by linear ‘propagator’ models. We find that the classification of trades as price-changing versus non-price-changing can explain the price impact nonlinearities and short-term return dynamics to a very high degree. The explanatory power provided by the change indicator in addition to the order sign history increases with increasing tick size. To obtain these results, several long-standing technical issues for model calibration and testing are addressed. We present new spectral estimators for two- and three-point cross-correlations, removing the need for previously used approximations. We also show when calibration is unbiased and how to accurately reveal previously overlooked biases. Therefore, our results contribute significantly to understanding both recent empirical results and the properties of a popular class of impact models.

The Buckling of Curved Tension-field Girders

NASA Technical Reports Server (NTRS)

Limpert, G

1938-01-01

The present paper reports on experiments made to determine the buckling load under shear of circular curved tension-field webs. The buckling load of the webs may be expressed with reference to the buckling load of the stiffeners. It is found that within the explored range the buckling load is approximately twice as great as that of the identically stiffened flat wall of equal web depth.

Height growth and site index curves for western white pine in the Cascade Range of Washington and Oregon.

Treesearch

Robert O. Curtis; Nancy M. Diaz; Gary W. Clendenen

1990-01-01

Height growth and site index curves were constructed from stem analyses of mature western white pine (Pinus monticola Dougl. ex D. Don) growing in high-elevation forests of the Cascade Range in the Mount Hood and Gifford Pinchot National Forests of Oregon and Washington, respectively. Alternate systems using reference ages for site index of 50 and...

Mixed-mode fatigue fracture of adhesive joints in harsh environments and nonlinear viscoelastic modeling of the adhesive

NASA Astrophysics Data System (ADS)

Arzoumanidis, Alexis Gerasimos

A four point bend, mixed-mode, reinforced, cracked lap shear specimen experimentally simulated adhesive joints between load bearing composite parts in automotive components. The experiments accounted for fatigue, solvent and temperature effects on a swirled glass fiber composite adherend/urethane adhesive system. Crack length measurements based on compliance facilitated determination of da/dN curves. A digital image processing technique was also utilized to monitor crack growth from in situ images of the side of the specimen. Linear elastic fracture mechanics and finite elements were used to determine energy release rate and mode-mix as a function of crack length for this specimen. Experiments were conducted in air and in a salt water bath at 10, 26 and 90°C. Joints tested in the solvent were fully saturated. In air, both increasing and decreasing temperature relative to 26°C accelerated crack growth rates. In salt water, crack growth rates increased with increasing temperature. Threshold energy release rate is shown to be the most appropriate design criteria for joints of this system. In addition, path of the crack is discussed and fracture surfaces are examined on three length scales. Three linear viscoelastic properties were measured for the neat urethane adhesive. Dynamic tensile compliance (D*) was found using a novel extensometer and results were considerably more accurate and precise than standard DMTA testing. Dynamic shear compliance (J*) was determined using an Arcan specimen. Dynamic Poisson's ratio (nu*) was extracted from strain gage data analyzed to include gage reinforcement. Experiments spanned three frequency decades and isothermal data was shifted by time-temperature superposition to create master curves spanning thirty decades. Master curves were fit to time domain Prony series. Shear compliance inferred from D* and nu* compared well with measured J*, forming a basis for finding the complete time dependent material property matrix for this isotropic material. A constitutive model is introduced which replaces time with internal energy in time-temperature superposition. Internal energy for mechanical loading was calculated from stress history and time domain Prony series representation of compliance. The model also included pressure and volume effects. Ramp loading experiments conducted at strain rates spanning three decades were effectively predicted, but unloading predictions were poor.

Overview of the TREC 2009 Legal Track

DTIC Science & Technology

2009-11-01

on the IIT CDIP 1.0 collection [9]), we turned, in 2009, to a collection of emails that had been produced by Enron in response to requests from the...collection as the 2006–2008 Legal Tracks, the IIT Complex Document Information Processing ( CDIP ) Test Collection, version 1.0 (referred to here as “IIT... CDIP 1.0”) which is based on scanned documents released under the tobacco “Master Settlement Agreement” (MSA). The University of California San

A Multigrid Approach to Embedded-Grid Solvers

DTIC Science & Technology

1992-08-01

previously as a Master’s Thesis at the University of Florida. Not edited by TESCO , Inc. 12a. DISTRIBUTION / AVAILABILITY STATEMENT 12b. DISTRIBUTION CODE...domain decomposition techniques in order to accurately model the aerodynamics of complex geometries 𔃾, 5, 11, 12, 13, 24’. Although these high...quantities subscripted by oc denote reference values in the undisturbed gas. Uv v, e e P - (10) Where • = (7b,/•)1/2, is the speed of sound in the

In Vitro Comparative Evaluation of Different Types of Impression Trays and Impression Materials on the Accuracy of Open Tray Implant Impressions: A Pilot Study

PubMed Central

Gupta, Sonam; Balakrishnan, Dhanasekar

2017-01-01

Purpose. For a precise fit of multiple implant framework, having an accurate definitive cast is imperative. The present study evaluated dimensional accuracy of master casts obtained using different impression trays and materials with open tray impression technique. Materials and Methods. A machined aluminum reference model with four parallel implant analogues was fabricated. Forty implant level impressions were made. Eight groups (n = 5) were tested using impression materials (polyether and vinylsiloxanether) and four types of impression trays, two being custom (self-cure acrylic and light cure acrylic) and two being stock (plastic and metal). The interimplant distances were measured on master casts using a coordinate measuring machine. The collected data was compared with a standard reference model and was statistically analyzed using two-way ANOVA. Results. Statistically significant difference (p < 0.05) was found between the two impression materials. However, the difference seen was small (36 μm) irrespective of the tray type used. No significant difference (p > 0.05) was observed between varied stock and custom trays. Conclusions. The polyether impression material proved to be more accurate than vinylsiloxanether impression material. The rigid nonperforated stock trays, both plastic and metal, could be an alternative for custom trays for multi-implant impressions when used with medium viscosity impression materials. PMID:28348595

[The requirements of standard and conditions of interchangeability of medical articles].

PubMed

Men'shikov, V V; Lukicheva, T I

2013-11-01

The article deals with possibility to apply specific approaches under evaluation of interchangeability of medical articles for laboratory analysis. The development of standardized analytical technologies of laboratory medicine and formulation of requirements of standards addressed to manufacturers of medical articles the clinically validated requirements are to be followed. These requirements include sensitivity and specificity of techniques, accuracy and precision of research results, stability of reagents' quality in particular conditions of their transportation and storage. The validity of requirements formulated in standards and addressed to manufacturers of medical articles can be proved using reference system, which includes master forms and standard samples, reference techniques and reference laboratories. This approach is supported by data of evaluation of testing systems for measurement of level of thyrotrophic hormone, thyroid hormones and glycated hemoglobin HB A1c. The versions of testing systems can be considered as interchangeable only in case of results corresponding to the results of reference technique and comparable with them. In case of absence of functioning reference system the possibilities of the Joined committee of traceability in laboratory medicine make it possible for manufacturers of reagent sets to apply the certified reference materials under development of manufacturing of sets for large listing of analytes.

Chandra Source Catalog: User Interface

NASA Astrophysics Data System (ADS)

Bonaventura, Nina; Evans, Ian N.; Rots, Arnold H.; Tibbetts, Michael S.; van Stone, David W.; Zografou, Panagoula; Primini, Francis A.; Glotfelty, Kenny J.; Anderson, Craig S.; Chen, Judy C.; Davis, John E.; Doe, Stephen M.; Evans, Janet D.; Fabbiano, Giuseppina; Galle, Elizabeth C.; Gibbs, Danny G., II; Grier, John D.; Hain, Roger; Hall, Diane M.; Harbo, Peter N.; He, Helen; Houck, John C.; Karovska, Margarita; Kashyap, Vinay L.; Lauer, Jennifer; McCollough, Michael L.; McDowell, Jonathan C.; Miller, Joseph B.; Mitschang, Arik W.; Morgan, Douglas L.; Mossman, Amy E.; Nichols, Joy S.; Nowak, Michael A.; Plummer, David A.; Refsdal, Brian L.; Siemiginowska, Aneta L.; Sundheim, Beth A.; Winkelman, Sherry L.

2009-09-01

The Chandra Source Catalog (CSC) is intended to be the definitive catalog of all X-ray sources detected by Chandra. For each source, the CSC provides positions and multi-band fluxes, as well as derived spatial, spectral, and temporal source properties. Full-field and source region data products are also available, including images, photon event lists, light curves, and spectra. The Chandra X-ray Center CSC website (http://cxc.harvard.edu/csc/) is the place to visit for high-level descriptions of each source property and data product included in the catalog, along with other useful information, such as step-by-step catalog tutorials, answers to FAQs, and a thorough summary of the catalog statistical characterization. Eight categories of detailed catalog documents may be accessed from the navigation bar on most of the 50+ CSC pages; these categories are: About the Catalog, Creating the Catalog, Using the Catalog, Catalog Columns, Column Descriptions, Documents, Conferences, and Useful Links. There are also prominent links to CSCview, the CSC data access GUI, and related help documentation, as well as a tutorial for using the new CSC/Google Earth interface. Catalog source properties are presented in seven scientific categories, within two table views: the Master Source and Source Observations tables. Each X-ray source has one ``master source'' entry and one or more ``source observation'' entries, the details of which are documented on the CSC ``Catalog Columns'' pages. The master source properties represent the best estimates of the properties of a source; these are extensively described on the following pages of the website: Position and Position Errors, Source Flags, Source Extent and Errors, Source Fluxes, Source Significance, Spectral Properties, and Source Variability. The eight tutorials (``threads'') available on the website serve as a collective guide for accessing, understanding, and manipulating the source properties and data products provided by the catalog.

DuPont Qualicon BAX System polymerase chain reaction assay. Performance Tested Method 100201.

PubMed

Tice, George; Andaloro, Bridget; Fallon, Dawn; Wallace, F Morgan

2009-01-01

A recent outbreak of Salmonella in peanut butter has highlighted the need for validation of rapid detection methods. A multilaboratory study for detecting Salmonella in peanut butter was conducted as part of the AOAC Research Institute Emergency Response Validation program for methods that detect outbreak threats to food safety. Three sites tested spiked samples from the same master mix according to the U.S. Food and Drug Administration's Bacteriological Analytical Manual (FDA-BAM) method and the BAX System method. Salmonella Typhimurium (ATCC 14028) was grown in brain heart infusion for 24 h at 37 degrees C, then diluted to appropriate levels for sample inoculation. Master samples of peanut butter were spiked at high and low target levels, mixed, and allowed to equilibrate at room temperature for 2 weeks. Spike levels were low [1.08 most probable number (MPN)/25 g]; high (11.5 MPN/25 g) and unspiked to serve as negative controls. Each master sample was divided into 25 g portions and coded to blind the samples. Twenty portions of each spiked master sample and five portions of the unspiked sample were tested at each site. At each testing site, samples were blended in 25 g portions with 225 mL prewarmed lactose broth until thoroughly homogenized, then allowed to remain at room temperature for 55-65 min. Samples were adjusted to a pH of 6.8 +/- 0.2, if necessary, and incubated for 22-26 h at 35 degrees C. Across the three reporting laboratories, the BAX System detected Salmonella in 10/60 low-spike samples and 58/60 high-spike samples. The reference FDA-BAM method yielded positive results for 11/60 low-spike and 58/60 high-spike samples. Neither method demonstrated positive results for any of the 15 unspiked samples.

Identifying Children at Risk of High Myopia Using Population Centile Curves of Refraction.

PubMed

Chen, Yanxian; Zhang, Jian; Morgan, Ian G; He, Mingguang

2016-01-01

To construct reference centile curves of refraction based on population-based data as an age-specific severity scale to evaluate their efficacy as a tool for identifying children at risk of developing high myopia in a longitudinal study. Data of 4218 children aged 5-15 years from the Guangzhou Refractive Error Study in Children (RESC) study, and 354 first-born twins from the Guangzhou Twin Eye Study (GTES) with annual visit were included in the analysis. Reference centile curves for refraction were constructed using a quantile regression model based on the cycloplegic refraction data from the RESC. The risk of developing high myopia (spherical equivalent ≤ -6 diopters [D]) was evaluated as a diagnostic test using the twin follow-up data. The centile curves suggested that the 3rd, 5th, and 10th percentile decreased from -0.25 D, 0.00 D and 0.25 D in 5 year-olds to -6.00 D, -5.65D and -4.63 D in 15 year-olds in the population-based data from RESC. In the GTES cohort, the 5th centile showed the most effective diagnostic value with a sensitivity of 92.9%, a specificity of 97.9% and a positive predictive value (PPV) of 65.0% in predicting high myopia onset (≤-6.00D) before the age of 15 years. The PPV was highest (87.5%) in 3rd centile but with only 50.0% sensitivity. The Mathew's correlation coefficient of 5th centile in predicting myopia of -6.0D/-5.0D/-4.0D by age of 15 was 0.77/0.51/0.30 respectively. Reference centile curves provide an age-specific estimation on a severity scale of refractive error in school-aged children. Children located under lower percentiles at young age were more likely to have high myopia at 15 years or probably in adulthood.

Fuzzy Multi-Objective Vendor Selection Problem with Modified S-CURVE Membership Function

NASA Astrophysics Data System (ADS)

Díaz-Madroñero, Manuel; Peidro, David; Vasant, Pandian

2010-06-01

In this paper, the S-Curve membership function methodology is used in a vendor selection (VS) problem. An interactive method for solving multi-objective VS problems with fuzzy goals is developed. The proposed method attempts simultaneously to minimize the total order costs, the number of rejected items and the number of late delivered items with reference to several constraints such as meeting buyers' demand, vendors' capacity, vendors' quota flexibility, vendors' allocated budget, etc. We compare in an industrial case the performance of S-curve membership functions, representing uncertainty goals and constraints in VS problems, with linear membership functions.

Method and system for real-time analysis of biosensor data

DOEpatents

Greenbaum, Elias; Rodriguez, Jr., Miguel

2014-08-19

A method of biosensor-based detection of toxins includes the steps of providing a fluid to be analyzed having a plurality of photosynthetic organisms therein, wherein chemical, biological or radiological agents alter a nominal photosynthetic activity of the photosynthetic organisms. At a first time a measured photosynthetic activity curve is obtained from the photosynthetic organisms. The measured curve is automatically compared to a reference photosynthetic activity curve to determine differences therebetween. The presence of the chemical, biological or radiological agents, or precursors thereof, are then identified if present in the fluid using the differences.

Morphometric Analysis of the Clavicles in Chinese Population

PubMed Central

Yang, Jesse Chieh-Szu; Lin, Kang-Ping

2017-01-01

The clavicle has a complex geometry that makes plate fixation technically difficult. The current study aims to measure the anatomical parameters of Chinese clavicles as reference for plate design. One hundred clavicles were analyzed. The clavicle bone model was reconstructed by using computed tomography images. The length, diameters, and curvatures of the clavicle were then measured. The female clavicle was shorter, more slender, and less curved in lateral part than the male clavicle. There was a positive relationship between height and clavicle parameters except lateral curve and depth. The measurements of Chinese clavicles were generally smaller than Caucasians. The clavicle curves were correlated with the bone length; thus consideration of the curve variations may be necessary as designing size distribution of clavicle plate. PMID:28497066

Rehabilitation reliability of the road pavement structure with recycled base course with foamed bitumen

NASA Astrophysics Data System (ADS)

Buczyński, P.

2018-05-01

This article presents a new approach to reliability assessment of the road structure in which the base layer will be constructed in the process of cold deep recycling with foamed bitumen. In order to properly assess the reliability of the structure with the recycled base, it is necessary to determine the distribution of stress and strain in typical pavement layer systems. The true stress and strain values were established for particular structural layers using the complex modulus (E*) determined based on the master curves. The complex modulus was determined by the direct tension-compression test on cylindrical specimens (DTC-CY) at five temperatures (-7°C, 5°C, 13°C, 25°C, 40°C) and six loading times (0.1 Hz, 0.3 Hz, 1 Hz, 3 Hz, 10 Hz, 20 Hz) in accordance with EN 12697-26 in the linear viscoelasticity (LVE) range for small strains ranging from 25 to 50 με. The master curves of the complex modulus were constructed using the Richards model for the mixtures typically incorporated in structural layers, i.e., SMA11, AC16W, AC22P and MCAS. The values of the modulus characterizing particular layers were determined with temperature distribution in the structure taken into account, when the surface temperature was 40°C. The stress distribution was established for those calculation models. The stress values were used to evaluate the fatigue life under controlled stress conditions (IT-FT). This evaluation, with the controlled stress corresponding to that in the structure, facilitated the quality assessment of the rehabilitated recycled base course. Results showed that the recycled base mixtures having the indirect tensile strength (ITSDRY) similar to the stress in the structure under analysis needed an additional fatigue life evaluation in the indirect tensile test ITT. This approach to the recycled base quality assessment will allow eliminating the damage induced by overloading.

Cardiovascular Effects of 1 Year of Progressive and Vigorous Exercise Training in Previously Sedentary Individuals Older Than 65 Years of Age

PubMed Central

Fujimoto, Naoki; Prasad, Anand; Hastings, Jeffrey L.; Arbab-Zadeh, Armin; Bhella, Paul S.; Shibata, Shigeki; Palmer, Dean; Levine, Benjamin D.

2013-01-01

Background Healthy but sedentary aging leads to cardiovascular stiffening, whereas life-long endurance training preserves left ventricular (LV) compliance. However, it is unknown whether exercise training started later in life can reverse the effects of sedentary behavior on the heart. Methods and Results Twelve sedentary seniors and 12 Masters athletes were thoroughly screened for comorbidities. Subjects underwent invasive hemodynamic measurements with pulmonary artery catheterization to define Starling and LV pressure-volume curves; secondary functional outcomes included Doppler echocardiography, magnetic resonance imaging assessment of cardiac morphology, arterial stiffness (total aortic compliance and arterial elastance), and maximal exercise testing. Nine of 12 sedentary seniors (70.6±3 years; 6 male, 3 female) completed 1 year of endurance training followed by repeat measurements. Pulmonary capillary wedge pressures and LV end-diastolic volumes were measured at baseline, during decreased cardiac filling with lower-body negative pressure, and increased filling with saline infusion. LV compliance was assessed by the slope of the pressure-volume curve. Before training, V̇O2max, LV mass, LV end-diastolic volume, and stroke volume were significantly smaller and the LV was less compliant in sedentary seniors than Masters athletes. One year of exercise training had little effect on cardiac compliance. However, it reduced arterial elastance and improved V̇O2 max by 19% (22.8±3.4 versus 27.2± 4.3 mL/kg/mL; P<0.001). LV mass increased (10%, 64.5±7.9 versus 71.2±12.3 g/m2; P=0.037) with no change in the mass-volume ratio. Conclusions Although 1 year of vigorous exercise training did not appear to favorably reverse cardiac stiffening in sedentary seniors, it nonetheless induced physiological LV remodeling and imparted favorable effects on arterial function and aerobic exercise capacity. PMID:20956204

Modeling the rheological behavior of thermosonic extracted guava, pomelo, and soursop juice concentrates at different concentration and temperature using a new combination model

PubMed Central

Abdullah, Norazlin; Yusof, Yus A.; Talib, Rosnita A.

2017-01-01

Abstract This study has modeled the rheological behavior of thermosonic extracted pink‐fleshed guava, pink‐fleshed pomelo, and soursop juice concentrates at different concentrations and temperatures. The effects of concentration on consistency coefficient (K) and flow behavior index (n) of the fruit juice concentrates was modeled using a master curve which utilized the concentration‐temperature shifting to allow a general prediction of rheological behaviors covering a wide concentration. For modeling the effects of temperature on K and n, the integration of two functions from the Arrhenius and logistic sigmoidal growth equations has provided a new model which gave better description of the properties. It also alleviated the problems of negative region when using the Arrhenius model alone. The fitted regression using this new model has improved coefficient of determination, R 2 values above 0.9792 as compared to using the Arrhenius and logistic sigmoidal models alone, which presented minimum R 2 of 0.6243 and 0.9440, respectively. Practical applications In general, juice concentrate is a better form of food for transportation, preservation, and ingredient. Models are necessary to predict the effects of processing factors such as concentration and temperature on the rheological behavior of juice concentrates. The modeling approach allows prediction of behaviors and determination of processing parameters. The master curve model introduced in this study simplifies and generalized rheological behavior of juice concentrates over a wide range of concentration when temperature factor is insignificant. The proposed new mathematical model from the combination of the Arrhenius and logistic sigmoidal growth models has improved and extended description of rheological properties of fruit juice concentrates. It also solved problems of negative values of consistency coefficient and flow behavior index prediction using existing model, the Arrhenius equation. These rheological data modeling provide good information for the juice processing and equipment manufacturing needs. PMID:29479123

The Assessment and Validation of Mini-Compact Tension Test Specimen Geometry and Progress in Establishing Technique for Fracture Toughness Master Curves for Reactor Pressure Vessel Steels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sokolov, Mikhail A.; Nanstad, Randy K.

Small specimens are playing the key role in evaluating properties of irradiated materials. The use of small specimens provides several advantages. Typically, only a small volume of material can be irradiated in a reactor at desirable conditions in terms of temperature, neutron flux, and neutron dose. A small volume of irradiated material may also allow for easier handling of specimens. Smaller specimens reduce the amount of radioactive material, minimizing personnel exposures and waste disposal. However, use of small specimens imposes a variety of challenges as well. These challenges are associated with proper accounting for size effects and transferability of smallmore » specimen data to the real structures of interest. Any fracture toughness specimen that can be made out of the broken halves of standard Charpy specimens may have exceptional utility for evaluation of reactor pressure vessels (RPVs) since it would allow one to determine and monitor directly actual fracture toughness instead of requiring indirect predictions using correlations established with impact data. The Charpy V-notch specimen is the most commonly used specimen geometry in surveillance programs. Assessment and validation of mini-CT specimen geometry has been performed on previously well characterized HSST Plate 13B, an A533B class 1 steel. It was shown that the fracture toughness transition temperature measured by these Mini-CT specimens is within the range of To values that were derived from various large fracture toughness specimens. Moreover, the scatter of the fracture toughness values measured by Mini-CT specimens perfectly follows the Weibull distribution function providing additional proof for validation of this geometry for the Master Curve evaluation of rector pressure vessel steels. Moreover, the International collaborative program has been developed to extend the assessment and validation efforts to irradiated weld metal. The program is underway and involves ORNL, CRIEPI, and EPRI.« less

Teaching the right hydrology with minimum resources in Ethiopia

NASA Astrophysics Data System (ADS)

Steenhuis, Tammo; Collick, Amy; Wondie, Ayalew; Jemberu, Tsehai

2010-05-01

This presentation will highlight our experience in teaching 19 Master's students from diverse backgrounds hydrology and watershed management in Ethiopia. Although the program was based at Bahir Dar University on the shores of Lake Tana in Ethiopia, the students received an US degree. The goal was to train professionals who can help to institute more effective and sustainable watershed management practices in Ethiopia. Teaching hydrology was a challenge. From the literature and personal observation, it was obvious that the traditional techniques of predicting runoff based on infiltration excess runoff and SCS curve number method were not satisfactory. Saturation excess runoff was more likely. However there was no research to prove that it actually was the case. In class we taught both runoff principles but stressed the saturation excess runoff. It was impossible to convince the students that the techniques that came from the western world be incorrect. For their Masters thesis, eight students did field research on runoff and erosion processes in watershed (some of which has a long record of discharge and sediment data). The students recorded water table heights, measured infiltration rates and determined where most erosion took place in the landscape. Based on this data they modeled the previously observed discharge successful using a saturation excess type model. From these studies we could establish that saturation in the landscape had a great effect on both runoff and sediment losses. As result of the field work, students had changed their mind about the appropriateness of using for example the SCS curve number method in Ethiopian highlands Perhaps the lesson to be learned is that we do not need a lot of funds to teach students the right hydrology. However, there is no substitute for going out in the field and experiencing what the right hydrology is by studying the processes in the landscape itself. By simply teaching in class, students will and cannot accept that the hydrologic processes that were taught for a century might be incorrect.

Effects of Average Signed Area Between Two Item Characteristic Curves and Test Purification Procedures on the DIF Detection via the Mantel-Haenszel Method

ERIC Educational Resources Information Center

Wang, Wen-Chung; Su, Ya-Hui

2004-01-01

In this study we investigated the effects of the average signed area (ASA) between the item characteristic curves of the reference and focal groups and three test purification procedures on the uniform differential item functioning (DIF) detection via the Mantel-Haenszel (M-H) method through Monte Carlo simulations. The results showed that ASA,…

Validating the weight gain of preterm infants between the reference growth curve of the fetus and the term infant

PubMed Central

2013-01-01

Background Current fetal-infant growth references have an obvious growth disjuncture around 40 week gestation overlapping where the fetal and infant growth references are combined. Graphical smoothening of the disjuncture to connect the matching percentile curves has never been validated. This study was designed to compare weight gain patterns of contemporary preterm infants with a fetal-infant growth reference (derived from a meta-analysis) to validate the previous smoothening assumptions and inform the revision of the Fenton chart. Methods Growth and descriptive data of preterm infants (23 to 31 weeks) from birth through 10 weeks post term age were collected in three cities in Canada and the USA between 2001 and 2010 (n = 977). Preterm infants were grouped by gestational age into 23–25, 26–28, and 29–31 weeks. Comparisons were made between the weight data of the preterm cohort and the fetal-infant growth reference. Results Median weight gain curves of the three preterm gestational age groups were almost identical and remained between the 3rd and the 50th percentiles of the fetal-infant-growth-reference from birth through 10 weeks post term. The growth velocity of the preterm infants decreased in a pattern similar to the decreased velocity of the fetus and term infant estimates, from a high of 17–18 g/kg/day between 31–34 weeks to rates of 4–5 g/kg/day by 50 weeks in each gestational age group. The greatest discrepancy in weight gain velocity between the preterm infants and the fetal estimate was between 37 and 40 weeks; preterm infants grew more rapidly than the fetus. The infants in this study regained their birthweight earlier compared to those in the 1999 National Institute of Child Health and Human Development report. Conclusion The weight gain velocity of preterm infants through the period of growth data disjuncture between 37 and 50 weeks gestation is consistent with and thus validates the smoothening assumptions made between preterm and post-term growth references. PMID:23758808

Validating the weight gain of preterm infants between the reference growth curve of the fetus and the term infant.

PubMed

Fenton, Tanis R; Nasser, Roseann; Eliasziw, Misha; Kim, Jae H; Bilan, Denise; Sauve, Reg

2013-06-11

Current fetal-infant growth references have an obvious growth disjuncture around 40 week gestation overlapping where the fetal and infant growth references are combined. Graphical smoothening of the disjuncture to connect the matching percentile curves has never been validated. This study was designed to compare weight gain patterns of contemporary preterm infants with a fetal-infant growth reference (derived from a meta-analysis) to validate the previous smoothening assumptions and inform the revision of the Fenton chart. Growth and descriptive data of preterm infants (23 to 31 weeks) from birth through 10 weeks post term age were collected in three cities in Canada and the USA between 2001 and 2010 (n = 977). Preterm infants were grouped by gestational age into 23-25, 26-28, and 29-31 weeks. Comparisons were made between the weight data of the preterm cohort and the fetal-infant growth reference. Median weight gain curves of the three preterm gestational age groups were almost identical and remained between the 3rd and the 50th percentiles of the fetal-infant-growth-reference from birth through 10 weeks post term. The growth velocity of the preterm infants decreased in a pattern similar to the decreased velocity of the fetus and term infant estimates, from a high of 17-18 g/kg/day between 31-34 weeks to rates of 4-5 g/kg/day by 50 weeks in each gestational age group. The greatest discrepancy in weight gain velocity between the preterm infants and the fetal estimate was between 37 and 40 weeks; preterm infants grew more rapidly than the fetus. The infants in this study regained their birthweight earlier compared to those in the 1999 National Institute of Child Health and Human Development report. The weight gain velocity of preterm infants through the period of growth data disjuncture between 37 and 50 weeks gestation is consistent with and thus validates the smoothening assumptions made between preterm and post-term growth references.

Propagation of stage measurement uncertainties to streamflow time series

NASA Astrophysics Data System (ADS)

Horner, Ivan; Le Coz, Jérôme; Renard, Benjamin; Branger, Flora; McMillan, Hilary

2016-04-01

Streamflow uncertainties due to stage measurements errors are generally overlooked in the promising probabilistic approaches that have emerged in the last decade. We introduce an original error model for propagating stage uncertainties through a stage-discharge rating curve within a Bayesian probabilistic framework. The method takes into account both rating curve (parametric errors and structural errors) and stage uncertainty (systematic and non-systematic errors). Practical ways to estimate the different types of stage errors are also presented: (1) non-systematic errors due to instrument resolution and precision and non-stationary waves and (2) systematic errors due to gauge calibration against the staff gauge. The method is illustrated at a site where the rating-curve-derived streamflow can be compared with an accurate streamflow reference. The agreement between the two time series is overall satisfying. Moreover, the quantification of uncertainty is also satisfying since the streamflow reference is compatible with the streamflow uncertainty intervals derived from the rating curve and the stage uncertainties. Illustrations from other sites are also presented. Results are much contrasted depending on the site features. In some cases, streamflow uncertainty is mainly due to stage measurement errors. The results also show the importance of discriminating systematic and non-systematic stage errors, especially for long term flow averages. Perspectives for improving and validating the streamflow uncertainty estimates are eventually discussed.

Apparatus and method for qualitative and quantitative measurements of optical properties of turbid media using frequency-domain photon migration

DOEpatents

Tromberg, B.J.; Tsay, T.T.; Berns, M.W.; Svaasand, L.O.; Haskell, R.C.

1995-06-13

Optical measurements of turbid media, that is media characterized by multiple light scattering, is provided through an apparatus and method for exposing a sample to a modulated laser beam. The light beam is modulated at a fundamental frequency and at a plurality of integer harmonics thereof. Modulated light is returned from the sample and preferentially detected at cross frequencies at frequencies slightly higher than the fundamental frequency and at integer harmonics of the same. The received radiance at the beat or cross frequencies is compared against a reference signal to provide a measure of the phase lag of the radiance and modulation ratio relative to a reference beam. The phase and modulation amplitude are then provided as a frequency spectrum by an array processor to which a computer applies a complete curve fit in the case of highly scattering samples or a linear curve fit below a predetermined frequency in the case of highly absorptive samples. The curve fit in any case is determined by the absorption and scattering coefficients together with a concentration of the active substance in the sample. Therefore, the curve fitting to the frequency spectrum can be used both for qualitative and quantitative analysis of substances in the sample even though the sample is highly turbid. 14 figs.

Apparatus and method for qualitative and quantitative measurements of optical properties of turbid media using frequency-domain photon migration

DOEpatents

Tromberg, Bruce J.; Tsay, Tsong T.; Berns, Michael W.; Svaasand, Lara O.; Haskell, Richard C.

1995-01-01

Optical measurements of turbid media, that is media characterized by multiple light scattering, is provided through an apparatus and method for exposing a sample to a modulated laser beam. The light beam is modulated at a fundamental frequency and at a plurality of integer harmonics thereof. Modulated light is returned from the sample and preferentially detected at cross frequencies at frequencies slightly higher than the fundamental frequency and at integer harmonics of the same. The received radiance at the beat or cross frequencies is compared against a reference signal to provide a measure of the phase lag of the radiance and modulation ratio relative to a reference beam. The phase and modulation amplitude are then provided as a frequency spectrum by an array processor to which a computer applies a complete curve fit in the case of highly scattering samples or a linear curve fit below a predetermined frequency in the case of highly absorptive samples. The curve fit in any case is determined by the absorption and scattering coefficients together with a concentration of the active substance in the sample. Therefore, the curve fitting to the frequency spectrum can be used both for qualitative and quantitative analysis of substances in the sample even though the sample is highly turbid.

Correcting intensity loss errors in the absence of texture-free reference samples during pole figure measurement

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saleh, Ahmed A., E-mail: asaleh@uow.edu.au

Even with the use of X-ray polycapillary lenses, sample tilting during pole figure measurement results in a decrease in the recorded X-ray intensity. The magnitude of this error is affected by the sample size and/or the finite detector size. These errors can be typically corrected by measuring the intensity loss as a function of the tilt angle using a texture-free reference sample (ideally made of the same alloy as the investigated material). Since texture-free reference samples are not readily available for all alloys, the present study employs an empirical procedure to estimate the correction curve for a particular experimental configuration.more » It involves the use of real texture-free reference samples that pre-exist in any X-ray diffraction laboratory to first establish the empirical correlations between X-ray intensity, sample tilt and their Bragg angles and thereafter generate correction curves for any Bragg angle. It will be shown that the empirically corrected textures are in very good agreement with the experimentally corrected ones. - Highlights: •Sample tilting during X-ray pole figure measurement leads to intensity loss errors. •Texture-free reference samples are typically used to correct the pole figures. •An empirical correction procedure is proposed in the absence of reference samples. •The procedure relies on reference samples that pre-exist in any texture laboratory. •Experimentally and empirically corrected textures are in very good agreement.« less

Exploring the utility of narrative analysis in diagnostic decision making: picture-bound reference, elaboration, and fetal alcohol spectrum disorders.

PubMed

Thorne, John C; Coggins, Truman E; Carmichael Olson, Heather; Astley, Susan J

2007-04-01

To evaluate classification accuracy and clinical feasibility of a narrative analysis tool for identifying children with a fetal alcohol spectrum disorder (FASD). Picture-elicited narratives generated by 16 age-matched pairs of school-aged children (FASD vs. typical development [TD]) were coded for semantic elaboration and reference strategy by judges who were unaware of age, gender, and group membership of the participants. Receiver operating characteristic (ROC) curves were used to examine the classification accuracy of the resulting set of narrative measures for making 2 classifications: (a) for the 16 children diagnosed with FASD, low performance (n = 7) versus average performance (n = 9) on a standardized expressive language task and (b) FASD (n = 16) versus TD (n = 16). Combining the rates of semantic elaboration and pragmatically inappropriate reference perfectly matched a classification based on performance on the standardized language task. More importantly, the rate of ambiguous nominal reference was highly accurate in classifying children with an FASD regardless of their performance on the standardized language task (area under the ROC curve = .863, confidence interval = .736-.991). Results support further study of the diagnostic utility of narrative analysis using discourse level measures of elaboration and children's strategic use of reference.

Variations on a simple dice game

NASA Astrophysics Data System (ADS)

Heafner, Joe

2018-04-01

I begin my introductory astronomy course with a unit on critical thinking that focuses on, among other things, the differences between the "scientific method" as frequently presented in textbooks and actual scientific practice. One particular classroom activity uses a simple dice game to simulate observation of a natural phenomenon and the process of figuring out the framework, which we have previously defined as the rules that allow us to make predictions, governing the simulated phenomenon. Using games to teach scientific methodology is not new (see Maloney and Masters and Smith and references therein). I have experimented with Maloney and Masters' games and discovered that my students found them too difficult to figure out and therefore they did not learn what I hoped they would from them. I also experimented with other card games and found that too many students already knew the rules of both well-known and obscure card games. I even tried inventing my own games with, at best, mediocre results.

Masters of adaptation: learning in late life adjustments.

PubMed

Roberson, Donald N

2005-01-01

The purpose of this research is to understand the relationship between human development in older adults and personal learning. Personal or self-directed learning (SDL) refers to a style of learning where the individual directs, controls, and evaluates what is learned. It may occur with formal classes, but most often takes place in non-formal situations. This study employed a descriptive qualitative design incorporating in-depth, semistructured interviews for data collection. The sample of 10 purposefully selected older adults from a rural area reflected diversity in gender, race, education, and employment. Data analysis was guided by the constant comparative method. The primary late life adjustments of these older adults were in response to having extra time, changes in family, and social and physical loss. This research also indicated that late life adjustments are a primary incentive for self-directed learning. The results of this study indicated that older adults become masters of adaptation through the use of self-directed learning activities.

Geopotential measurements with synchronously linked optical lattice clocks

NASA Astrophysics Data System (ADS)

Takano, Tetsushi; Takamoto, Masao; Ushijima, Ichiro; Ohmae, Noriaki; Akatsuka, Tomoya; Yamaguchi, Atsushi; Kuroishi, Yuki; Munekane, Hiroshi; Miyahara, Basara; Katori, Hidetoshi

2016-10-01

According to Einstein's theory of relativity, the passage of time changes in a gravitational field. On Earth, raising a clock by 1 cm increases its apparent tick rate by 1.1 parts in 1018, allowing chronometric levelling through comparison of optical clocks. Here, we demonstrate such geopotential measurements by determining the height difference of master and slave clocks separated by 15 km with an uncertainty of 5 cm. A subharmonic of the master clock laser is delivered through a telecom fibre to synchronously operate the distant clocks. Clocks operated under such phase coherence reject clock laser noise and facilitate proposals for linking clocks and interferometers. Taken over half a year, 11 measurements determine the fractional frequency difference between the two clocks to be 1,652.9(5.9) × 10-18, consistent with an independent measurement by levelling and gravimetry. Our system demonstrates a building block for an internet of clocks, which may constitute ‘quantum benchmarks’, serving as height references with dynamic responses.

A versatile small form factor twisted-pair TFC FMC for MTCA AMCs

NASA Astrophysics Data System (ADS)

Meder, L.; Lebedev, J.; Becker, J.

2017-03-01

In continuous readout systems of particle physics experiments, the provision of a common clock and time reference and the distribution of critical low latency messages to the processing and fronted layers of the readout are crucial tasks. In the context of the Compressed Baryonic Matter (CBM) experiment, a versatile small form factor Timing and Fast-Control (TFC) interfacing FPGA Mezzanine Card (FMC) was developed, offering bidirectional twisted-pair (TP) links for the communication between TFC nodes. Also a versatile clocking including voltage controlled oscillators and a connection to the telecommunication clock lines of mTCA crates are available. Being designed for both TFC Master and Slaves, the card allows rapid system developments without additional Slave hardware circuits. Measurements show that it is possible to transmit over cable lengths of 25 m at a rate of 240 Mbit/s for all data channels simultaneously. A TFC Master-Slave system using two of these cards can be synchronized with a precision of ±10 ps to an user-defined phase setpoint.

Evaluation of postprandial glucose excursion using a novel minimally invasive glucose area-under-the-curve monitoring system.

PubMed

Kuranuki, Sachi; Sato, Toshiyuki; Okada, Seiki; Hosoya, Samiko; Seko, Akinobu; Sugihara, Kaya; Nakamura, Teiji

2013-01-01

To develop a minimally invasive interstitial fluid extraction technology (MIET) to monitor postprandial glucose area under the curve (AUC) without blood sampling, we evaluated the accuracy of glucose AUC measured by MIET and compared with that by blood sampling after food intake. Interstitial fluid glucose AUC (IG-AUC) following consumption of 6 different types of foods was measured by MIET. MIET consisted of stamping microneedle arrays, placing hydrogel patches on the areas, and calculating IG-AUC based on glucose levels in the hydrogels. Glycemic index (GI) was determined using IG-AUC and reference AUC measured by blood sampling. IG-AUC strongly correlated with reference AUC (R = 0.91), and GI determined using IG-AUC showed good correlation with that determined by reference AUC (R = 0.88). IG-AUC obtained by MIET can accurately predict the postprandial glucose excursion without blood sampling. In addition, feasibility of GI measurement by MIET was confirmed.

Fatigue behavior of a cross-ply metal matrix composite at elevated temperature under strain controlled mode. Master`s thesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dennis, L.B.

1994-12-01

This research extends the existing knowledge of cross-ply metal matrix composites (MMC) to include fatigue behavior under strain-controlled fully reversed loading. This study investigated fatigue life, failure modes and damage mechanisms of the SCS-6/Ti-15-3, (O/9O)2s, MMC. The laminate was subjected to fully reversed fatigue at elevated temperature (427 deg C) at various strain levels. Stress, strain and modulus data were analyzed to characterize the macro-mechanical behavior of the composite. Microscopy and fractography were accomplished to identify and characterize the damage mechanisms at the microscopic level. Failure modes varied according to the maximum applied strain level showing either mixed mode (i.e.more » combination of both fiber and matrix dominated modes) or matrix dominated fatigue failures. As expected, higher strain loadings resulted in more ductility of the matrix at failure, evidenced by fracture surface features. For testing of the same composite laminate, the fatigue life under strain controlled mode slightly increased, compared to its load-controlled mode counterpart, using the effective strain range comparison basis. However, the respective fatigue life curves converged in the high cycle region, suggesting that the matrix dominated failure mode produces equivalent predicted fatigue lives for both control modes.« less

Overview of the TREC 2008 Legal Track

DTIC Science & Technology

2008-11-01

CDIP ) Test Collection, version 1.0 (referred to here as “IIT CDIP 1.0”) which is based on documents released under the tobacco “Master Settlement...repository, the Legacy Tobacco Documents Library (LTDL), for tobacco documents [9]. The IIT CDIP 1.0 collection is based on a snapshot, generated between...November 2005 and January 2006, of the MSA subcollection of the LTDL. The IIT CDIP 1.0 collection consists of 6,910,192 document records in the form of

Integrating the Master of Software Assurance Reference Curriculum into the Model Curriculum and Guidelines for Graduate Degree Programs in Information Systems

DTIC Science & Technology

2011-02-01

Model Curriculum and Guidelines for Graduate Degree Programs in Information Systems (MSIS) 2006 is the latest product of a project that has been...conducted for nearly 40 years [Gor- gone 2006]. Various organizations affiliated with the project have developed specifications for the teaching of...considerations helps ensure that an institution’s individual courses of study are relevant to the industry that its students are preparing to enter

U.S. Geological Survey National Computer Technology Meeting: Program and Abstracts, Norfolk, Virginia, May 17-22, 1992

DTIC Science & Technology

1992-05-01

formats, and character formats that can easily integrate graphics and text into one document. FrameMaker is one of few ERP software programs that has...easier and faster using ERP software. The DIS-II ERP software program is FrameMaker by Frame Technology, Incorporated. FrameMaker uses the X window...functions, calculus, relations, and other complicated math applications. FrameMaker permits the user to define formats for master pages, reference pages

The Joint Improvised Explosive Device Defeat Organization: DOD’s Fight Against IEDs Today and Tomorrow

DTIC Science & Technology

2008-11-01

In 2004, senior military commanders called for a “ Manhattan Project -like” effort against IEDs, and the Department of Defense (DOD) later...reference to the Manhattan Project by U.S. Central Command leaders was meant to convey the need for a large-scale, focused effort, combining the nation’s...of a highway in southern Iraq. USA Photo/Master Sergeant Lek Mateo. 15 JIEDDO TODAY We’ve got to have something like the Manhattan Project . General

Low Temperature Irradiation Embrittlement of Reactor Pressure Vessel Steels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Jy-An John

2015-08-01

The embrittlement trend curve development project for HFIR reactor pressure vessel (RPV) steels was carried out with three major tasks. Which are (1) data collection to match that used in HFIR steel embrittlement trend published in 1994 Journal Nuclear Material by Remec et. al, (2) new embrittlement data of A212B steel that are not included in earlier HFIR RPV trend curve, and (3) the adjustment of nil-ductility-transition temperature (NDTT) shift data with the consideration of the irradiation temperature effect. An updated HFIR RPV steel embrittlement trend curve was developed, as described below. NDTT( C) = 23.85 log(x) + 203.3 logmore » (x) + 434.7, with 2- uncertainty of 34.6 C, where parameter x is referred to total dpa. The developed update HFIR RPV embrittlement trend curve has higher embrittlement rate compared to that of the trend curve developed in 1994.« less

A Jeziorski-Monkhorst fully uncontracted multi-reference perturbative treatment. I. Principles, second-order versions, and tests on ground state potential energy curves

NASA Astrophysics Data System (ADS)

Giner, Emmanuel; Angeli, Celestino; Garniron, Yann; Scemama, Anthony; Malrieu, Jean-Paul

2017-06-01

The present paper introduces a new multi-reference perturbation approach developed at second order, based on a Jeziorski-Mokhorst expansion using individual Slater determinants as perturbers. Thanks to this choice of perturbers, an effective Hamiltonian may be built, allowing for the dressing of the Hamiltonian matrix within the reference space, assumed here to be a CAS-CI. Such a formulation accounts then for the coupling between the static and dynamic correlation effects. With our new definition of zeroth-order energies, these two approaches are strictly size-extensive provided that local orbitals are used, as numerically illustrated here and formally demonstrated in the Appendix. Also, the present formalism allows for the factorization of all double excitation operators, just as in internally contracted approaches, strongly reducing the computational cost of these two approaches with respect to other determinant-based perturbation theories. The accuracy of these methods has been investigated on ground-state potential curves up to full dissociation limits for a set of six molecules involving single, double, and triple bond breaking together with an excited state calculation. The spectroscopic constants obtained with the present methods are found to be in very good agreement with the full configuration interaction results. As the present formalism does not use any parameter or numerically unstable operation, the curves obtained with the two methods are smooth all along the dissociation path.

Diabetic retinopathy screening using deep neural network.

PubMed

Ramachandran, Nishanthan; Hong, Sheng Chiong; Sime, Mary J; Wilson, Graham A

2017-09-07

There is a burgeoning interest in the use of deep neural network in diabetic retinal screening. To determine whether a deep neural network could satisfactorily detect diabetic retinopathy that requires referral to an ophthalmologist from a local diabetic retinal screening programme and an international database. Retrospective audit. Diabetic retinal photos from Otago database photographed during October 2016 (485 photos), and 1200 photos from Messidor international database. Receiver operating characteristic curve to illustrate the ability of a deep neural network to identify referable diabetic retinopathy (moderate or worse diabetic retinopathy or exudates within one disc diameter of the fovea). Area under the receiver operating characteristic curve, sensitivity and specificity. For detecting referable diabetic retinopathy, the deep neural network had an area under receiver operating characteristic curve of 0.901 (95% confidence interval 0.807-0.995), with 84.6% sensitivity and 79.7% specificity for Otago and 0.980 (95% confidence interval 0.973-0.986), with 96.0% sensitivity and 90.0% specificity for Messidor. This study has shown that a deep neural network can detect referable diabetic retinopathy with sensitivities and specificities close to or better than 80% from both an international and a domestic (New Zealand) database. We believe that deep neural networks can be integrated into community screening once they can successfully detect both diabetic retinopathy and diabetic macular oedema. © 2017 Royal Australian and New Zealand College of Ophthalmologists.

Network global navigation satellite system survey to harmonize water-surface elevation data for the Rainy River Basin

USGS Publications Warehouse

Ziegeweid, Jeffrey R.; Silliker, R. Jason; Densmore, Brenda K.; Krahulik, Justin

2016-08-15

Continuously recording water-level streamgages in Rainy Lake and Namakan Reservoir are used to regulate water levels according to rule curves established in 2000 by the International Joint Commission; however, water levels at streamgages were referenced to a variety of vertical datums, confounding efforts to model the flow of water through the system, regulate water levels during periods of high inflow, and evaluate the effectiveness of the rule curves. In October 2014, the U.S. Geological Survey, Natural Resources Canada, International Joint Commission, and National Park Service began a joint field study with the goal of obtaining precise elevations referenced to a uniform vertical datum for all reference marks used to set water levels at streamgages throughout Rainy Lake and Namakan Reservoir. This report was prepared by the U.S. Geological Survey in cooperation with Natural Resources Canada, International Joint Commission, and National Park Service.Three field crews deployed Global Navigation Satellite System receivers statically over 16 reference marks colocated with active and discontinued water-level streamgages throughout Rainy River, Rainy Lake, Namakan Reservoir, and select tributaries of Rainy Lake and Namakan Reservoir. A Global Navigation Satellite System receiver also was deployed statically over a National Geodetic Survey cooperative base network control station for use as a quality-control reference mark. Satellite data were collected simultaneously during a 5-day period and processed independently by the U.S. Geological Survey and Natural Resources Canada to obtain accurate positioning and elevations for the 17 surveyed reference marks. Processed satellite data were used to convert published water levels to elevations above sea level referenced to the Canadian Geodetic Vertical Datum of 2013 in order to compare water-surface elevations referenced to a uniform vertical datum throughout the study area. In this report, an “offset” refers to the correction applied to published data from a particular streamgage to produce elevation data referenced to a specified vertical datum.Offsets were applied to water-level data from surveyed streamgages to further evaluate the accuracy and utility of updated reference mark elevations presented in this report. Daily mean water levels from active streamgages surveyed in this study were converted to water-surface elevations referenced to the Canadian Geodetic Vertical Datum of 2013. Graphical comparisons of water-surface elevations for streamgages in Namakan Reservoir, Rainy Lake, and selected rivers are presented (referencing the Canadian Geodetic Vertical Datum of 2013). Offsets presented in this report can be used in the evaluation of rule curves and in flood damage curves that fully assess the benefits of one regulation approach over another. In addition, offsets may be used to calibrate hydraulic models developed for four narrows that connect lakes of Namakan Reservoir, refine digital elevation models, and support modeling studies designed to assess the effects of rule curves on aquatic vegetation, benthic invertebrates, northern pike, and walleye.

Enhancing the Equating of Item Difficulty Metrics: Estimation of Reference Distribution. Research Report. ETS RR-14-07

ERIC Educational Resources Information Center

Ali, Usama S.; Walker, Michael E.

2014-01-01

Two methods are currently in use at Educational Testing Service (ETS) for equating observed item difficulty statistics. The first method involves the linear equating of item statistics in an observed sample to reference statistics on the same items. The second method, or the item response curve (IRC) method, involves the summation of conditional…

Meta-analysis of Diagnostic Accuracy and ROC Curves with Covariate Adjusted Semiparametric Mixtures.

PubMed

Doebler, Philipp; Holling, Heinz

2015-12-01

Many screening tests dichotomize a measurement to classify subjects. Typically a cut-off value is chosen in a way that allows identification of an acceptable number of cases relative to a reference procedure, but does not produce too many false positives at the same time. Thus for the same sample many pairs of sensitivities and false positive rates result as the cut-off is varied. The curve of these points is called the receiver operating characteristic (ROC) curve. One goal of diagnostic meta-analysis is to integrate ROC curves and arrive at a summary ROC (SROC) curve. Holling, Böhning, and Böhning (Psychometrika 77:106-126, 2012a) demonstrated that finite semiparametric mixtures can describe the heterogeneity in a sample of Lehmann ROC curves well; this approach leads to clusters of SROC curves of a particular shape. We extend this work with the help of the [Formula: see text] transformation, a flexible family of transformations for proportions. A collection of SROC curves is constructed that approximately contains the Lehmann family but in addition allows the modeling of shapes beyond the Lehmann ROC curves. We introduce two rationales for determining the shape from the data. Using the fact that each curve corresponds to a natural univariate measure of diagnostic accuracy, we show how covariate adjusted mixtures lead to a meta-regression on SROC curves. Three worked examples illustrate the method.

Optical properties of randomly distributed soot: improved polarimetric and intensity scattering functions

NASA Astrophysics Data System (ADS)

Renard, Jean-Baptiste; Daugeron, Daniel; Personne, Pascal; Legros, Guillaume; Baillargeat, Jacques; Hadamcik, Edith; Worms, Jean-Claude

2005-02-01

Reference scattering curves for polarization and intensity produced by aggregates and agglomerates of ethylene and kerosene soot are obtained for scattering angles in the 10-170° range. The polarization measurements were obtained with the Propriétés Optiques des Grains Astronomiques et Atmosphèriques instrument for particles that levitate in microgravity during parabolic flights and on the ground by an air draught technique. The intensity measurements were obtained also on the ground with a Laboratoire de Metéorologie Physique nephelometer. The maximum polarization is of the order of 80% at a scattering angle of 80° at lambda = 632.8 nm and approximately 75% at an angle of 90° at lambda = 543.5 nm. The polarization increases by approximately 10% when the size of the agglomerate increases from 10 μm to a few hundred micrometers. The intensity curve exhibits a strong increase at small scattering angles. These reference curves will be used in the near future for the detection of stratospheric soot by remote-sensing measurement techniques.

Lung function in North American Indian children: reference standards for spirometry, maximal expiratory flow volume curves, and peak expiratory flow.

PubMed

Wall, M A; Olson, D; Bonn, B A; Creelman, T; Buist, A S

1982-02-01

Reference standards of lung function was determined in 176 healthy North American Indian children (94 girls, 82 boys) 7 to 18 yr of age. Spirometry, maximal expiratory flow volume curves, and peak expiratory flow rate were measured using techniques and equipment recommended by the American Thoracic Society. Standing height was found to be an accurate predictor of lung function, and prediction equations for each lung function variable are presented using standing height as the independent variable. Lung volumes and expiratory flow rates in North American Indian children were similar to those previously reported for white and Mexican-American children but were greater than those in black children. In both boys and girls, lung function increased in a curvilinear fashion. Volume-adjusted maximal expiratory flow rates after expiring 50 or 75% of FVC tended to decrease in both sexes as age and height increased. Our maximal expiratory flow volume curve data suggest that as North American Indian children grow, lung volume increases at a slightly faster rate than airway size does.

Bayesian Inference of Nonstationary Precipitation Intensity-Duration-Frequency Curves for Infrastructure Design

DTIC Science & Technology

2016-03-01

design . ERDC/CHL CHETN-X-2. Vicksburg, MS: U.S. Army Engineer Research and Development Center. http://chl.erdc.usace.army. mil/chetn REFERENCES...Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, edited by S. Solomon , D. Qin, M. Manning, Z. Chen, M...Duration- Frequency Curves for Infrastructure Design by Brian E. Skahill, Amir AghaKouchak, Linyin Cheng, Aaron Byrd, and Joseph Kanney

Friction and universal contact area law for randomly rough viscoelastic contacts.

PubMed

Scaraggi, M; Persson, B N J

2015-03-18

We present accurate numerical results for the friction force and the contact area for a viscoelastic solid (rubber) in sliding contact with hard, randomly rough substrates. The rough surfaces are self-affine fractal with roughness over several decades in length scales. We calculate the contribution to the friction from the pulsating deformations induced by the substrate asperities. We also calculate how the area of real contact, A(v, p), depends on the sliding speed v and on the nominal contact pressure p, and we show how the contact area for any sliding speed can be obtained from a universal master curve A(p). The numerical results are found to be in good agreement with the predictions of an analytical contact mechanics theory.

Desmin filaments studied by quasi-elastic light scattering.

PubMed Central

Hohenadl, M; Storz, T; Kirpal, H; Kroy, K; Merkel, R

1999-01-01

We studied polymers of desmin, a muscle-specific type III intermediate filament protein, using quasi-elastic light scattering. Desmin was purified from chicken gizzard. Polymerization was induced either by 2 mM MgCl(2) or 150 mM NaCl. The polymer solutions were in the semidilute regime. We concluded that the persistence length of the filaments is between 0.1 and 1 microm. In all cases, we found a hydrodynamic diameter of desmin filaments of 16-18 nm. The filament dynamics exhibits a characteristic frequency in the sense that correlation functions measured on one sample but at different scattering vectors collapse onto a single master curve when time is normalized by the experimentally determined initial decay rate. PMID:10512839

Liquid ingress recognition in honeycomb structure by pulsed thermography

NASA Astrophysics Data System (ADS)

Chen, Dapeng; Zeng, Zhi; Tao, Ning; Zhang, Cunlin; Zhang, Zheng

2013-05-01

Pulsed thermography has been proven to be a fast and effective method to detect fluid ingress in aircraft honeycomb structure; however, water and hydraulic oil may have similar appearance in the thermal image sequence. It is meaningful to identify what kind of liquid ingress it is for aircraft maintenance. In this study, honeycomb specimens with glass fiber and aluminum skin are injected different kinds of liquids: water and oil. Pulsed thermography is adopted; a recognition method is proposed to first get the reference curve by linear fitting the beginning of the logarithmic curve, and then an algorithm based on the thermal contrast between liquid and reference is used to recognize what kind of fluid it is by calculating their thermal properties. It is verified with the results of theory and the finite element simulation.

Fuzzy Multi-Objective Transportation Planning with Modified S-Curve Membership Function

NASA Astrophysics Data System (ADS)

Peidro, D.; Vasant, P.

2009-08-01

In this paper, the S-Curve membership function methodology is used in a transportation planning decision (TPD) problem. An interactive method for solving multi-objective TPD problems with fuzzy goals, available supply and forecast demand is developed. The proposed method attempts simultaneously to minimize the total production and transportation costs and the total delivery time with reference to budget constraints and available supply, machine capacities at each source, as well as forecast demand and warehouse space constraints at each destination. We compare in an industrial case the performance of S-curve membership functions, representing uncertainty goals and constraints in TPD problems, with linear membership functions.

The Universal Transverse Mercator (UTM) grid

USGS Publications Warehouse

,

1997-01-01

The most convenient way to identify points on the curved surface of the Earth is with a system of reference lines called parallels of latitude and meridians of longitude. On some maps the meridians and parallels appear as straight lines. On most modern maps, however, the meridians and parallels may appear as curved lines. These differences are due to the mathematical treatment required to portray a curved surface on a flat surface so that important properties of the map (such as distance and areal accuracy) are shown with minimum distortion. The system used to portray a portion of the round Earth on a flat surface is called a map projection.

The Universal Transverse Mercator (UTM) grid

USGS Publications Warehouse

,

1999-01-01

The most convenient way to identify points on the curved surface of the Earth is with a system of reference lines called parallels of latitude and meridians of longitude. On some maps, the meridians and parallels appear as straight lines. On most modern maps, however, the meridians and parallels appear as curved lines. These differences sre due to the mathematical treatment required to portray a curved surface on a flat surface so that important properties of the map (such as distance and areal accuracy) are shown with minimum distortion. The system used to portray a portion of the round Earth on a flat surface is called a map projection.

Vertical rod temperatures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roy, G.M.

1951-08-14

An important factor affecting the decision on the use of a seal around the VSR on ``C`` is the temperature at which the rod can be expected to reach. Also the temperature of the rod-tip affects the choice of tip moderating material. These temperatures are calculated for a given set of conditions for ``C`` pile. The results of the calculations are best seen by referring to the attached figures. The affects of emissivity and weight of rod can be estimated by comparing the proper curves. The assumed conditions for calculating each curve are important and therefore, the basis for eachmore » curve is given separately.« less

Critical behaviour and filed dependence of magnetic entropy change in K-doped manganites Pr0.8Na0.2-xKxMnO3 (x = 0.10 and 0.15)

NASA Astrophysics Data System (ADS)

Ben Khlifa, H.; M'nassri, R.; Tarhouni, S.; Regaieg, Y.; Cheikhrouhou-Koubaa, W.; Chniba-Boudjada, N.; Cheikhrouhou, A.

2018-01-01

The orthorhombic Pr0.8Na0.2-xKxMnO3 (x = 0.10 and 0.15) manganites are prepared by using the solid state reaction at high temperatures. The critical exponents (β, γ, δ) are investigated through various techniques such as modified Arrott plot, Kouvel-Fisher method and critical isotherm analysis based on the data of the magnetic measurements recorded around the Curie temperature. The critical exponents are derived from the magnetization data using the Kouvel-Fisher method, are found to be β = 0.32(4) and γ = 1.29(2) at TC 123 K for x = 0.10 and β = 0.31(1) and γ = 1.25(2) at TC 133 K for x = 0.15. The critical exponent values obtained for both samples are comparable to the values predicted by the 3D-Ising model, and have also been verified by the scaling equation of state. Such results demonstrate the existence of ferromagnetic short-range order in our materials. The magnetic entropy changes of polycrystalline samples with a second-order phase transition are investigated. A large magnetic entropy change deduced from isothermal magnetization curves, is observed in our samples with a peak centered on their respective Curie temperatures (TC). The field dependence of the magnetic entropy changes are analyzed, which show power law dependence ΔSmax ≈ a(μ0 H) n at transition temperature. The values of n obey to the Curie Weiss law above the transition temperature. It is shown that for the investigated materials, the magnetic entropy change follow a master curve behaviour. The rescaled magnetic entropy change curves for different applied fields collapse onto a single curve for both samples.

[Customized and non-customized French intrauterine growth curves. II - Comparison with existing curves and benefits of customization].

PubMed

Ego, A; Prunet, C; Blondel, B; Kaminski, M; Goffinet, F; Zeitlin, J

2016-02-01

Our aim is to compare the new French EPOPé intrauterine growth curves, developed to address the guidelines 2013 of the French College of Obstetricians and Gynecologists, with reference curves currently used in France, and to evaluate the consequences of their adjustment for fetal sex and maternal characteristics. Eight intrauterine and birthweight curves, used in France were compared to the EPOPé curves using data from the French Perinatal Survey 2010. The influence of adjustment on the rate of SGA births and the characteristics of these births was analysed. Due to their birthweight values and distribution, the selected intrauterine curves are less suitable for births in France than the new curves. Birthweight curves led to low rates of SGA births from 4.3 to 8.5% compared to 10.0% with the EPOPé curves. The adjustment for maternal and fetal characteristics avoids the over-representation of girls among SGA births, and reclassifies 4% of births. Among births reclassified as SGA, the frequency of medical and obstetrical risk factors for growth restriction, smoking (≥10 cigarettes/day), and neonatal transfer is higher than among non-SGA births (P<0.01). The EPOPé curves are more suitable for French births than currently used curves, and their adjustment improves the identification of mothers and babies at risk of growth restriction and poor perinatal outcomes. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Synchronization of an optomechanical system to an external drive

NASA Astrophysics Data System (ADS)

Amitai, Ehud; Lörch, Niels; Nunnenkamp, Andreas; Walter, Stefan; Bruder, Christoph

2017-05-01

Optomechanical systems driven by an effective blue-detuned laser can exhibit self-sustained oscillations of the mechanical oscillator. These self-oscillations are a prerequisite for the observation of synchronization. Here, we study the synchronization of the mechanical oscillations to an external reference drive. We study two cases of reference drives: (1) an additional laser applied to the optical cavity; (2) a mechanical drive applied directly to the mechanical oscillator. Starting from a master equation description, we derive a microscopic Adler equation for both cases, valid in the classical regime in which the quantum shot noise of the mechanical self-oscillator does not play a role. Furthermore, we numerically show that, in both cases, synchronization arises also in the quantum regime. The optomechanical system is therefore a good candidate for the study of quantum synchronization.

A Bayesian CUSUM plot: Diagnosing quality of treatment.

PubMed

Rosthøj, Steen; Jacobsen, Rikke-Line

2017-12-01

To present a CUSUM plot based on Bayesian diagnostic reasoning displaying evidence in favour of "healthy" rather than "sick" quality of treatment (QOT), and to demonstrate a technique using Kaplan-Meier survival curves permitting application to case series with ongoing follow-up. For a case series with known final outcomes: Consider each case a diagnostic test of good versus poor QOT (expected vs. increased failure rates), determine the likelihood ratio (LR) of the observed outcome, convert LR to weight taking log to base 2, and add up weights sequentially in a plot showing how many times odds in favour of good QOT have been doubled. For a series with observed survival times and an expected survival curve: Divide the curve into time intervals, determine "healthy" and specify "sick" risks of failure in each interval, construct a "sick" survival curve, determine the LR of survival or failure at the given observation times, convert to weights, and add up. The Bayesian plot was applied retrospectively to 39 children with acute lymphoblastic leukaemia with completed follow-up, using Nordic collaborative results as reference, showing equal odds between good and poor QOT. In the ongoing treatment trial, with 22 of 37 children still at risk for event, QOT has been monitored with average survival curves as reference, odds so far favoring good QOT 2:1. QOT in small patient series can be assessed with a Bayesian CUSUM plot, retrospectively when all treatment outcomes are known, but also in ongoing series with unfinished follow-up. © 2017 John Wiley & Sons, Ltd.

Distribution of physical properties and timing of relative uplift in upper plate off Costa Rica: IODP Expedition 344

NASA Astrophysics Data System (ADS)

Saiki, A.; Hashimoto, Y.

2015-12-01

Evolution of physical properties in subduction zone is a key to understand lithification processes, location of decollement, and stress distribution. In this study, we examined the physical properties of sediments using on-board data and laboratory experimental data on sediments obtained off Costa Rica margin. Target sites are in the Integrate Ocean Drilling Program (IODP) Expedition 344 off Costa Rica, including reference sites (U1381 and U1414), mid-slope site (U1378, U1380) and upper-slope site (U1413). Seven samples from reference sites were analyzed. Laboratory experiments for velocity and porosity measurements were conducted with variation of effective pressure. Velocity-porosity relationships from on-board data and from laboratory experiments are comparable. The porosity-effective pressure curves under isotropic condition were converted to the curves under uniaxial condition (Teeuw, 1971). Using the normal consolidation curves under uniaxial stress conditions, we converted onboard porosity to effective pressure and fluid pressure. In reference sites, hydrostatic fluid pressure was estimated as expected as a reference sites, suggesting that porosity-effective pressure relationship was obtained correctly by experiments and it can be adapted to estimation of fluid pressure for the wedge sites. The porosity-effective pressure relationship under isotropic conditions were used for the estimation in wedge sites. In wedge sites, estimated pore pressures show lower than hydrostatic pressure, suggesting that onboard porosity was lower than that under normal compaction. The lower porosity can be caused by relative uplift from deeper portion. The amount of relative uplift can be estimated by differences in porosity-depth relationships between onboard data and experimental data. The amount of relative uplift for each site shows more than ~1000m up to ~5000m. The small error in porosity depth curve from experimental data makes relative uplift larger or smaller exponentially in the deeper portion. The increment of relative uplift, however, starts from about 1Ma in each site, suggesting some events were occurred at the timing. Laboratory experiments under differential stress should be conducted in the near future because smaller porosity is expected under differential stress conditions.

Growth references for Tsimane forager-horticulturalists of the Bolivian Amazon

PubMed Central

Blackwell, Aaron D.; Urlacher, Samuel S.; Beheim, Bret; von Rueden, Christopher; Jaeggi, Adrian; Stieglitz, Jonathan; Trumble, Benjamin C.; Gurven, Michael; Kaplan, Hillard

2016-01-01

Objectives Growth standards and references currently used to assess population and individual health are derived primarily from urban populations, including few individuals from indigenous or subsistence groups. Given environmental and genetic differences, growth may vary in these populations. Thus, there is a need to assess whether international standards are appropriate for all populations, and to produce population specific references if growth differs. Here we present and assess growth references for the Tsimane, an indigenous population of Bolivian forager-horticulturalists. Methods Mixed cross-sectional/longitudinal anthropometrics (9,614 individuals; 30,118 observations; ages 0–29 years) were used to generate centile curves and Lambda-Mu-Sigma (LMS) tables for height-for-age, weight-for-age, body mass index (BMI)-for-age, and weight-for-height (WFH) using Generalized Additive Models for Location Shape and Scale (GAMLSS). Velocity curves were generated using SuperImposition by Translation and Rotation (SITAR). Tsimane ≤5 years were compared World Health Organization (WHO) standards while those >5 years were compared to WHO school age references. All ages were compared to published references for Shuar forager-horticulturalists of the Ecuadorian Amazon. Results Tsimane growth differs from WHO values in height and weight, but is similar for BMI and WFH. Tsimane growth is characterized by slow height velocity in childhood and early adolescent peak height velocity at 11.3 and 13.2 years for girls and boys. Tsimane growth patterns are similar to Shuar, suggesting shared features of growth among indigenous South Americans. Conclusions International references for BMI-for-age and WFH are likely appropriate for Tsimane, but differences in height-for-age and weight-for-age suggest Tsimane specific references may be useful for these measures. PMID:28218400

Growth references for Tsimane forager-horticulturalists of the Bolivian Amazon.

PubMed

Blackwell, Aaron D; Urlacher, Samuel S; Beheim, Bret; von Rueden, Christopher; Jaeggi, Adrian; Stieglitz, Jonathan; Trumble, Benjamin C; Gurven, Michael; Kaplan, Hillard

2017-03-01

Growth standards and references currently used to assess population and individual health are derived primarily from urban populations, including few individuals from indigenous or subsistence groups. Given environmental and genetic differences, growth may vary in these populations. Thus, there is a need to assess whether international standards are appropriate for all populations, and to produce population specific references if growth differs. Here we present and assess growth references for the Tsimane, an indigenous population of Bolivian forager-horticulturalists. Mixed cross-sectional/longitudinal anthropometrics (9,614 individuals; 30,118 observations; ages 0-29 years) were used to generate centile curves and Lambda-Mu-Sigma (LMS) tables for height-for-age, weight-for-age, body mass index (BMI)-for-age, and weight-for-height (WFH) using Generalized Additive Models for Location Shape and Scale (GAMLSS). Velocity curves were generated using SuperImposition by Translation and Rotation (SITAR). Tsimane ≤5 years were compared to World Health Organization (WHO) standards while those >5 years were compared to WHO school age references. All ages were compared to published references for Shuar forager-horticulturalists of the Ecuadorian Amazon. Tsimane growth differs from WHO values in height and weight, but is similar for BMI and WFH. Tsimane growth is characterized by slow height velocity in childhood and early adolescent peak height velocity at 11.3 and 13.2 years for girls and boys. Tsimane growth patterns are similar to Shuar, suggesting shared features of growth among indigenous South Americans. International references for BMI-for-age and WFH are likely appropriate for Tsimane, but differences in height-for-age and weight-for-age suggest Tsimane specific references may be useful for these measures. © 2016 Wiley Periodicals, Inc.

Excimer Potential Curves

DTIC Science & Technology

1980-01-01

lasers see A. V. Phelps, JILA Report 110, "Tunable Gas Lasers Using Ground State Dissociation," (1972) and references therein. 2. This requires highly...possibility of using GaXe as a laser if the Ga can be obtained from dissociation of Gal 3 . Consequently the GaKr curves should also be of intrinsic interest... laser transitions The interest in the group IIIB-rare gas systems arises from the possibility of their use as visible laser systems. In order to judge

Spatial and temporal patterns of macrozoobenthic community inhabiting sediments under tropical fish farming

NASA Astrophysics Data System (ADS)

Aufa, Abdullah; Hadi, Mochamad; Purnomo Putro, Sapto

2018-05-01

Macrozoobenthic animals is one of biota that may be used to assess the impact of the activities. They inhabit sediment of water ecosystem and may respond vary at different spatiotemporal scales. The purpose of this study is to study spatial and temporal patterns of macrozoobenthic community under fish farming activities at coastal area of Tembelas Island, Kepulauan Riau Province, Indonesia. The macrozoobenthic assemblages were assessedat three sampling locations, i.e. policulture [IMTA], monoculture and reference sites. Each sampling location consisted of three stations with three replicates for each station. The data obtained were analyzed using PRIMER software V.6.1.5. to compare number of taxa (S), Shanon- Wiener diversity index (H’), and Pielou’s evenness index (e) and K-dominance cumulative curves between sites and times. The results showed that diversity index at fish farming locations (IMTA and monoculture) exhibited lower than those at reference site, between 1.58 – 2.19 and between 1.99-2.84, respectively. However, diversity at all locations were considered moderate diverse ecosystem. Meanwhile, Pielou’s evenness indexbetween locations and sampling time showed no majordifference, ranging between 0.96-0.98. Based on K-dominance curves, P3T2 station curve was positioned on the top among other curves, implying certain taxa has dominated the assemblages, i.e. Nassarius sp. (Gastropod).

Comparison of irradiation-induced shifts of K{sub Jc} and Charpy impact toughness for reactor pressure vessel steels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sokolov, M.A.; Nanstad, R.K.

1999-10-01

The current provisions for determination of the upward temperature shift of the lower-bound static fracture toughness curve due to irradiation of reactor pressure vessel steels are based on the assumption that they are the same as the Charpy 41-J shifts as a consequence of irradiation. The objective of this paper is to evaluate this assumption relative to data reported in open publications. Depending on the specific source, different sizes of fracture toughness specimens, procedures of the K{sub Jc} determination, and fitting functions were used. It was anticipated that the scatter might be reduced by using a consistent approach to analyzemore » the published data. A method employing Weibull statistics is applied to analyze original fracture toughness data of unirradiated and irradiated pressure vessel steels. Application of the master curve concept is used to determine shifts of fracture toughness transition curves. A hyperbolic tangent function is used to fit charpy absorbed energy data. The fracture toughness shifts are compared to Charpy impact shifts evaluated with various criteria. Linear regression analysis showed that for weld metals, on average, the fracture toughness shift is the same as the Charpy 41-J temperature shift, while for base metals, on average, the fracture toughness shift at 41 J is 16% greater than the shift of the Charpy 41-J transition temperature, with both correlations having relatively large 95% confidence intervals.« less

Strain-rate dependence of ramp-wave evolution and strength in tantalum

DOE PAGES

Lane, J. Matthew D.; Foiles, Stephen M.; Lim, Hojun; ...

2016-08-25

We have conducted molecular dynamics (MD) simulations of quasi-isentropic ramp-wave compression to very high pressures over a range of strain rates from 10 11 down to 10 8 1/s. Using scaling methods, we collapse wave profiles from various strain rates to a master profile curve, which shows deviations when material response is strain-rate dependent. Thus, we can show with precision where, and how, strain-rate dependence affects the ramp wave. We find that strain rate affects the stress-strain material response most dramatically at strains below 20%, and that above 30% strain the material response is largely independent of strain rate. Wemore » show good overall agreement with experimental stress-strain curves up to approximately 30% strain, above which simulated response is somewhat too stiff. We postulate that this could be due to our interatomic potential or to differences in grain structure and/or size between simulation and experiment. Strength is directly measured from per-atom stress tensor and shows significantly enhanced elastic response at the highest strain rates. As a result, this enhanced elastic response is less pronounced at higher pressures and at lower strain rates.« less

Developments in holographic-based scanner designs

NASA Astrophysics Data System (ADS)

Rowe, David M.

1997-07-01

Holographic-based scanning systems have been used for years in the high resolution prepress markets where monochromatic lasers are generally utilized. However, until recently, due to the dispersive properties of holographic optical elements (HOEs), along with the high cost associated with recording 'master' HOEs, holographic scanners have not been able to penetrate major scanning markets such as the laser printer and digital copier markets, low to mid-range imagesetter markets, and the non-contact inspection scanner market. Each of these markets has developed cost effective laser diode based solutions using conventional scanning approaches such as polygon/f-theta lens combinations. In order to penetrate these markets, holographic-based systems must exhibit low cost and immunity to wavelength shifts associated with laser diodes. This paper describes recent developments in the design of holographic scanners in which multiple HOEs, each possessing optical power, are used in conjunction with one curved mirror to passively correct focal plane position errors and spot size changes caused by the wavelength instability of laser diodes. This paper also describes recent advancements in low cost production of high quality HOEs and curved mirrors. Together these developments allow holographic scanners to be economically competitive alternatives to conventional devices in every segment of the laser scanning industry.

A curved surface micro-moiré method and its application in evaluating curved surface residual stress

NASA Astrophysics Data System (ADS)

Zhang, Hongye; Wu, Chenlong; Liu, Zhanwei; Xie, Huimin

2014-09-01

The moiré method is typically applied to the measurement of deformations of a flat surface while, for a curved surface, this method is rarely used other than for projection moiré or moiré interferometry. Here, a novel colour charge-coupled device (CCD) micro-moiré method has been developed, based on which a curved surface micro-moiré (CSMM) method is proposed with a colour CCD and optical microscope (OM). In the CSMM method, no additional reference grating is needed as a Bayer colour filter array (CFA) installed on the OM in front of the colour CCD image sensor performs this role. Micro-moiré fringes with high contrast are directly observed with the OM through the Bayer CFA under the special condition of observing a curved specimen grating. The principle of the CSMM method based on a colour CCD micro-moiré method and its application range and error analysis are all described in detail. In an experiment, the curved surface residual stress near a welded seam on a stainless steel tube was investigated using the CSMM method.

Quasispecies in population of compositional assemblies.

PubMed

Gross, Renan; Fouxon, Itzhak; Lancet, Doron; Markovitch, Omer

2014-12-30

The quasispecies model refers to information carriers that undergo self-replication with errors. A quasispecies is a steady-state population of biopolymer sequence variants generated by mutations from a master sequence. A quasispecies error threshold is a minimal replication accuracy below which the population structure breaks down. Theory and experimentation of this model often refer to biopolymers, e.g. RNA molecules or viral genomes, while its prebiotic context is often associated with an RNA world scenario. Here, we study the possibility that compositional entities which code for compositional information, intrinsically different from biopolymers coding for sequential information, could show quasispecies dynamics. We employed a chemistry-based model, graded autocatalysis replication domain (GARD), which simulates the network dynamics within compositional molecular assemblies. In GARD, a compotype represents a population of similar assemblies that constitute a quasi-stationary state in compositional space. A compotype's center-of-mass is found to be analogous to a master sequence for a sequential quasispecies. Using single-cycle GARD dynamics, we measured the quasispecies transition matrix (Q) for the probabilities of transition from one center-of-mass Euclidean distance to another. Similarly, the quasispecies' growth rate vector (A) was obtained. This allowed computing a steady state distribution of distances to the center of mass, as derived from the quasispecies equation. In parallel, a steady state distribution was obtained via the GARD equation kinetics. Rewardingly, a significant correlation was observed between the distributions obtained by these two methods. This was only seen for distances to the compotype center-of-mass, and not to randomly selected compositions. A similar correspondence was found when comparing the quasispecies time dependent dynamics towards steady state. Further, changing the error rate by modifying basal assembly joining rate of GARD kinetics was found to display an error catastrophe, similar to the standard quasispecies model. Additional augmentation of compositional mutations leads to the complete disappearance of the master-like composition. Our results show that compositional assemblies, as simulated by the GARD formalism, portray significant attributes of quasispecies dynamics. This expands the applicability of the quasispecies model beyond sequence-based entities, and potentially enhances validity of GARD as a model for prebiotic evolution.

Modeling the space debris environment with MASTER-2009 and ORDEM2010

NASA Astrophysics Data System (ADS)

Flegel, Sven Kevin; Krisko, Paula; Gelhaus, Johannes; Wiedemann, Carsten; Moeckel, Marek; Krag, Holger; Klinkrad, Heiner; Xu, Yu-Lin; Horstman, Matthew; Matney, Mark; Vörsmann, Peter

The two software tools MASTER-2009 and ORDEM2010 are the ESA and NASA reference software tools respectively which describe the earth's debris environment. The primary goal of both programs is to allow users to estimate the object flux onto a target object for mission planning. The current paper describes the basic distinctions in the model philosophies. At the core of each model lies the method by which the object environment is established. Cen-tral to this process is the role played by the results from radar/telescope observations or impact fluxes on surfaces returned from earth orbit. The ESA Meteoroid and Space Debris Terrestrial Environment Reference Model (MASTER) is engineered to give a realistic description of the natural and the man-made particulate environment of the earth. Debris sources are simulated based on detailed lists of known historical events such as fragmentations or solid rocket motor firings or through simulation of secondary debris such as impact ejecta or the release of paint flakes from degrading spacecraft surfaces. The resulting population is then validated against historical telescope/radar campaigns using the ESA Program for Radar and Optical Observa-tion Forecasting (PROOF) and against object impact fluxes on surfaces returned from space. The NASA Orbital Debris Engineering Model (ORDEM) series is designed to provide reliable estimates of orbital debris flux on spacecraft and through telescope or radar fields-of-view. Central to the model series is the empirical nature of the input populations. These are derived from NASA orbital debris modeling but verified, where possible, with measurement data from various sources. The latest version of the series, ORDEM2010, compiles over two decades of data from NASA radar systems, telescopes, in-situ sources, and ground tests that are analyzed by statistical methods. For increased understanding of the application ranges of the two programs, the current paper provides an overview of the two models' main program features and the methods by which simulation results are presented. This paper is written in a combined effort by ESA and NASA.

The Computational Science Education Reference Desk: A tool for increasing inquiry based learning in the science classroom

NASA Astrophysics Data System (ADS)

Joiner, D. A.; Stevenson, D. E.; Panoff, R. M.

2000-12-01

The Computational Science Reference Desk is an online tool designed to provide educators in math, physics, astronomy, biology, chemistry, and engineering with information on how to use computational science to enhance inquiry based learning in the undergraduate and pre college classroom. The Reference Desk features a showcase of original content exploration activities, including lesson plans and background materials; a catalog of websites which contain models, lesson plans, software, and instructional resources; and a forum to allow educators to communicate their ideas. Many of the recent advances in astronomy rely on the use of computer simulation, and tools are being developed by CSERD to allow students to experiment with some of the models that have guided scientific discovery. One of these models allows students to study how scientists use spectral information to determine the makeup of the interstellar medium by modeling the interstellar extinction curve using spherical grains of silicate, amorphous carbon, or graphite. Students can directly compare their model to the average interstellar extinction curve, and experiment with how small changes in their model alter the shape of the interstellar extinction curve. A simpler model allows students to visualize spatial relationships between the Earth, Moon, and Sun to understand the cause of the phases of the moon. A report on the usefulness of these models in two classes, the Computational Astrophysics workshop at The Shodor Education Foundation and the Conceptual Astronomy class at the University of North Carolina at Greensboro, will be presented.

Facilitating the development of higher-order thinking skills (HOTS) of novice nursing postgraduates in Africa.

PubMed

Roets, Lizeth; Maritz, Jeanette

2017-02-01

International research in nursing education has shown to be deficient regarding both the quality of research produced and the building of disciplinary capacity. The CHENMA (Collaboration for Higher Education of Nurses and Midwives in Africa) project aimed to strengthen nursing and midwifery expertise in Africa. Sixteen French-speaking students of the Democratic Republic of the Congo (DRC) enrolled for a master's degree in nursing midwifery at a South African university in 2008. Ten of the initial 16 students graduated with a master's degree in 2012. One student withdrew and five students completed a postgraduate diploma in midwifery. The objective of this paper is to explore the quality of the output of those master's degree students, namely their dissertation (with specific reference to the demonstration of HOTS). An exploratory, evaluative, single, descriptive case study was utilised. Realist, purposeful sampling was used. Six of the 10 completed final dissertations were evaluated as well as three reflective reports from the supervisor, translator and critical reader. The findings indicated that most dissertations fell below the expected standard, with a paucity of higher-order thinking and application skills. Language, and possibly cultural dynamics, seemed to be the largest barrier to learning and communication. The dissertations lacked conceptual skills, scientific writing skills, logical order of thought and congruency. Analysis of the dissertations revealed a limited ability of novice scholars to explore the nature of information and to interpret and manipulate the data in a novel way. Copyright © 2016 Elsevier Ltd. All rights reserved.

Parity and cobordism of free knots

DOE Office of Scientific and Technical Information (OSTI.GOV)

Manturov, Vassily O

2012-02-28

A simple invariant is constructed which obstructs a free knot to be truncated. In particular, this invariant provides an obstruction to the truncatedness of curves immersed in two-dimensional surfaces. A curve on an oriented two-dimensional surface S{sub g} is referred to as truncated (null-cobordant) if there exists a three-dimensional manifold M with boundary S{sub g} and a smooth proper map of a two-disc to M such that the image of the boundary of the disc coincides with the curve. The problem of truncatedness for free knots is solved in this paper using the notion of parity recently introduced by themore » author. Bibliography: 12 titles.« less

Photoionization Efficiencies of Five Polycyclic Aromatic Hydrocarbons.

PubMed

Johansson, K Olof; Campbell, Matthew F; Elvati, Paolo; Schrader, Paul E; Zádor, Judit; Richards-Henderson, Nicole K; Wilson, Kevin R; Violi, Angela; Michelsen, Hope A

2017-06-15

We have measured photoionization-efficiency curves for pyrene, fluoranthene, chrysene, perylene, and coronene in the photon energy range of 7.5-10.2 eV and derived their photoionization cross-section curves in this energy range. All measurements were performed using tunable vacuum ultraviolet (VUV) radiation generated at the Advanced Light Source synchrotron at Lawrence Berkeley National Laboratory. The VUV radiation was used for photoionization, and detection was performed using a time-of-flight mass spectrometer. We measured the photoionization efficiency of 2,5-dimethylfuran simultaneously with those of pyrene, fluoranthene, chrysene, perylene, and coronene to obtain references of the photon flux during each measurement from the known photoionization cross-section curve of 2,5-dimethylfuran.

Streamline curvature in supersonic shear layers

NASA Technical Reports Server (NTRS)

Kibens, V.

1992-01-01

Results of an experimental investigation in which a curved shear layer was generated between supersonic flow from a rectangular converging/diverging nozzle and the freestream in a series of open channels with varying radii of curvature are reported. The shear layers exhibit unsteady large-scale activity at supersonic pressure ratios, indicating increased mixing efficiency. This effect contrasts with supersonic flow in a straight channel, for which no large-scale vortical structure development occurs. Curvature must exceed a minimum level before it begins to affect the dynamics of the supersonic shear layer appreciably. The curved channel flows are compared with reference flows consisting of a free jet, a straight channel, and wall jets without sidewalls on a flat and a curved plate.

Structural characterization of a first-generation articulated-truss joint for space crane application

NASA Technical Reports Server (NTRS)

Sutter, Thomas R.; Wu, K. Chauncey; Riutort, Kevin T.; Laufer, Joseph B.; Phelps, James E.

1992-01-01

A first-generation space crane articulated-truss joint was statically and dynamically characterized in a configuration that approximated an operational environment. The articulated-truss joint was integrated into a test-bed for structural characterization. Static characterization was performed by applying known loads and measuring the corresponding deflections to obtain load-deflection curves. Dynamic characterization was performed using modal testing to experimentally determine the first six mode shapes, frequencies, and modal damping values. Static and dynamic characteristics were also determined for a reference truss that served as a characterization baseline. Load-deflection curves and experimental frequency response functions are presented for the reference truss and the articulated-truss joint mounted in the test-bed. The static and dynamic experimental results are compared with analytical predictions obtained from finite element analyses. Load-deflection response is also presented for one of the linear actuators used in the articulated-truss joint. Finally, an assessment is presented for the predictability of the truss hardware used in the reference truss and articulated-truss joint based upon hardware stiffness properties that were previously obtained during the Precision Segmented Reflector (PSR) Technology Development Program.

Space-based augmentation for global navigation satellite systems.

PubMed

Grewal, Mohinder S

2012-03-01

This paper describes space-based augmentation for global navigation satellite systems (GNSS). Space-based augmentations increase the accuracy and integrity of the GNSS, thereby enhancing users' safety. The corrections for ephemeris, ionospheric delay, and clocks are calculated from reference station measurements of GNSS data in wide-area master stations and broadcast via geostationary earth orbit (GEO) satellites. This paper discusses the clock models, satellite orbit determination, ionospheric delay estimation, multipath mitigation, and GEO uplink subsystem (GUS) as used in the Wide Area Augmentation System developed by the FAA.

On time scales and time synchronization using LORAN-C as a time reference signal

NASA Technical Reports Server (NTRS)

Chi, A. R.

1974-01-01

The long term performance of the eight LORAN-C chains is presented in terms of the Coordinated Universal Time (UTC) of the U.S. Naval Observatory (USNO); and the use of the LORAN-C navigation system for maintaining the user's clock to a UTC scale is described. The atomic time scale and the UTC of several national laboratories and observatories relative to the international atomic time are reported. Typical performance of several NASA tracking station clocks, relative to the USNO master clock, is also presented.

Microbial biodiversity of Tang and Pirgal mud volcanoes and evaluation of bio-emulsifier and bio-demulsifier activities of Capnophile bacteria.

PubMed

Parsia, Yasaman; Sorooshian, Shahryar

2017-12-01

The data presented in this article is related to the Master thesis; entitled "Survey Aerobic Microbial Diversity Mud Volcanoes in Chabahar and Khash Ports in Southern Iran" by the first author of this article, year 2011, Islamic Azad University, Iran (reference number (Parsia, 2011) [1] of this article). This article shows microbial biodiversity and evaluates bio-emulsifier and bio-demulsifier abilities of capnophile isolates, in order to introduce a superior isolate for the Microbial Enhanced Oil Recovery (MEOR) process in the petrochemical industry.

The Recruitment, Education, and Training of PLA Navy Personnel (China Maritime Study, Number 12)

DTIC Science & Technology

2014-08-01

as to “cultivate,” “ nurture ,” “foster,” “train,” “develop,” or “educate.”9 It is defined in this context as the process by which cadets master the...individuals with criminal records or who are otherwise barred from service and subjecting the remaining candidates to physical, political, and psy...That all recruits continue to be referred to as conscripts demonstrates the oxymoronic nature of the system and suggests a reluctance to aban- don it

A Comparison of Three Curve Intersection Algorithms

NASA Technical Reports Server (NTRS)

Sederberg, T. W.; Parry, S. R.

1985-01-01

An empirical comparison is made between three algorithms for computing the points of intersection of two planar Bezier curves. The algorithms compared are: the well known Bezier subdivision algorithm, which is discussed in Lane 80; a subdivision algorithm based on interval analysis due to Koparkar and Mudur; and an algorithm due to Sederberg, Anderson and Goldman which reduces the problem to one of finding the roots of a univariate polynomial. The details of these three algorithms are presented in their respective references.

Comparative Analysis of Virtual 3-D Visual Display Systems Contributions to Cross-Functional Team Collaboration in a Product Design Review Environment

DTIC Science & Technology

1998-01-01

including the surface they lie on and the edge curves that bind them. Also stored is topological information indicating how all these elements are connected...microchip. This technology researched by Texas Instruments is referred to as a Digital Micromirror Device (DMD) (Burdea & Coiffet, 1994). It has the...stereoscopic imaging system designed to resemble traditional designer drafting boards. The Visionarium uses a 180 degree curved screen providing users with

Fundamentals and Methods of High Angle-of-Attack Flying Qualities Research

DTIC Science & Technology

1988-01-01

the subject, Carr sites the work of Ham and Gorelick (1968) (Reference (26)) which showed that additional lift could be created by rapid pitching of...the laminar boundary layer near the leading-edge. Thicker airfoils (t/c > 0. 12), 32 NADC 88020-60 representative of figure 24b, typically create ...lift-curve can result from leading-edge flow separation as shown in figure 24a. An airplance with this type of lift-curve would exhibit little or no

Advantages of soft versus hard constraints in self-modeling curve resolution problems. Alternating least squares with penalty functions.

PubMed

Gemperline, Paul J; Cash, Eric

2003-08-15

A new algorithm for self-modeling curve resolution (SMCR) that yields improved results by incorporating soft constraints is described. The method uses least squares penalty functions to implement constraints in an alternating least squares algorithm, including nonnegativity, unimodality, equality, and closure constraints. By using least squares penalty functions, soft constraints are formulated rather than hard constraints. Significant benefits are (obtained using soft constraints, especially in the form of fewer distortions due to noise in resolved profiles. Soft equality constraints can also be used to introduce incomplete or partial reference information into SMCR solutions. Four different examples demonstrating application of the new method are presented, including resolution of overlapped HPLC-DAD peaks, flow injection analysis data, and batch reaction data measured by UV/visible and near-infrared spectroscopy (NIR). Each example was selected to show one aspect of the significant advantages of soft constraints over traditionally used hard constraints. Incomplete or partial reference information into self-modeling curve resolution models is described. The method offers a substantial improvement in the ability to resolve time-dependent concentration profiles from mixture spectra recorded as a function of time.

Studies of excited states of HeH by the multi-reference configuration-interaction method

NASA Astrophysics Data System (ADS)

Lee, Chun-Woo; Gim, Yeongrok

2013-11-01

The excited states of a HeH molecule for an n of up to 4 are studied using the multi-reference configuration-interaction method and Kaufmann's Rydberg basis functions. The advantages of using two different ways of locating Rydberg orbitals, either on the atomic nucleus or at the charge centre of molecules, are exploited by limiting their application to different ranges of R. Using this method, the difference between the experimental binding energies of the lower Rydberg states obtained by Ketterle and the ab initio results obtained by van Hemert and Peyerimhoff is reduced from a few hundreds of wave numbers to a few tens of wave numbers. A substantial improvement in the accuracy allows us to obtain quantum defect curves characterized by the correct behaviour. We obtain several Rydberg series that have more than one member, such as the ns series (n = 2, 3 and 4), npσ series (n = 3 and 4), npπ (n = 2, 3, 4) series and ndπ (n = 3, 4) series. These quantum defect curves are compared to the quantum defect curves obtained by the R-matrix or the multichannel quantum defect theory methods.

Interconversion of mechanical and dielectrical relaxation measurements for dicyclohexylmethyl-2-methyl succinate.

PubMed

Díaz-Calleja, R; Garcia-Bernabé, A; Sanchis, M J; del Castillo, L F

2005-11-01

A comparison between results of dielectrical relaxation and dynamic mechanical spectroscopies is carried out for the alpha-relaxation of the ester dicyclohexyl methyl-2-methyl succinate (DCMMS). The results for the dielectric permittivity and the shear modulus measurements are presented according to the empirical Havriliak-Negami (HN) equation. By using the time-temperature principle a master curve in each case was obtained for several temperatures. The comparative analysis presented here is based on the assumption of a relationship between rotational and shear viscosities. The former one is associated to the dielectrical relaxation, whereas the latter is associated to mechanical relaxation. Both viscosities are not necessarily equal in general, and we assume that the difference between them is an important factor to appropriately compare the dielectrical and mechanical results.

Interactions between silica particles in the presence of multivalent coions.

PubMed

Uzelac, Biljana; Valmacco, Valentina; Trefalt, Gregor

2017-08-30

Forces between charged silica particles in solutions of multivalent coions are measured with colloidal probe technique based on atomic force microscopy. The concentration of 1 : z electrolytes is systematically varied to understand the behavior of electrostatic interactions and double-layer properties in these systems. Although the coions are multivalent the Derjaguin, Landau, Verwey, and Overbeek (DLVO) theory perfectly describes the measured force profiles. The diffuse-layer potentials and regulation properties are extracted from the forces profiles by using the DLVO theory. The dependencies of the diffuse-layer potential and regulation parameter shift to lower concentration with increasing coion valence when plotted as a function of concentration of 1 : z salt. Interestingly, these profiles collapse to a master curve if plotted as a function of monovalent counterion concentration.

Pressure Effect on the Boson Peak in Deeply Cooled Confined Water: Evidence of a Liquid-Liquid Transition.

PubMed

Wang, Zhe; Kolesnikov, Alexander I; Ito, Kanae; Podlesnyak, Andrey; Chen, Sow-Hsin

2015-12-04

The boson peak in deeply cooled water confined in nanopores is studied to examine the liquid-liquid transition (LLT). Below ∼180  K, the boson peaks at pressures P higher than ∼3.5  kbar are evidently distinct from those at low pressures by higher mean frequencies and lower heights. Moreover, the higher-P boson peaks can be rescaled to a master curve while the lower-P boson peaks can be rescaled to a different one. These phenomena agree with the existence of two liquid phases with different densities and local structures and the associated LLT in the measured (P, T) region. In addition, the P dependence of the librational band also agrees with the above conclusion.

Epidemic spreading in a hierarchical social network.

PubMed

Grabowski, A; Kosiński, R A

2004-09-01

A model of epidemic spreading in a population with a hierarchical structure of interpersonal interactions is described and investigated numerically. The structure of interpersonal connections is based on a scale-free network. Spatial localization of individuals belonging to different social groups, and the mobility of a contemporary community, as well as the effectiveness of different interpersonal interactions, are taken into account. Typical relations characterizing the spreading process, like a range of epidemic and epidemic curves, are discussed. The influence of preventive vaccinations on the spreading process is investigated. The critical value of preventively vaccinated individuals that is sufficient for the suppression of an epidemic is calculated. Our results are compared with solutions of the master equation for the spreading process and good agreement of the character of this process is found.

Scaling Behavior for Ionic Transport and its Fluctuations in Individual Carbon Nanotubes.

PubMed

Secchi, Eleonora; Niguès, Antoine; Jubin, Laetitia; Siria, Alessandro; Bocquet, Lydéric

2016-04-15

In this Letter, we perform an experimental study of ionic transport and current fluctuations inside individual carbon nanotubes (CNTs). The conductance exhibits a power law behavior at low salinity, with an exponent close to 1/3 versus the salt concentration in this regime. This behavior is rationalized in terms of a salinity dependent surface charge, which is accounted for on the basis of a model for hydroxide adsorption at the (hydrophobic) carbon surface. This is in contrast to boron nitride nanotubes which exhibit a constant surface conductance. Further, we measure the low frequency noise of the ionic current in CNTs and show that the amplitude of the noise scales with the surface charge, with data collapsing on a master curve for the various studied CNTs at a given pH.

Scaling Behavior for Ionic Transport and its Fluctuations in Individual Carbon Nanotubes

NASA Astrophysics Data System (ADS)

Secchi, Eleonora; Niguès, Antoine; Jubin, Laetitia; Siria, Alessandro; Bocquet, Lydéric

2016-04-01

In this Letter, we perform an experimental study of ionic transport and current fluctuations inside individual carbon nanotubes (CNTs). The conductance exhibits a power law behavior at low salinity, with an exponent close to 1 /3 versus the salt concentration in this regime. This behavior is rationalized in terms of a salinity dependent surface charge, which is accounted for on the basis of a model for hydroxide adsorption at the (hydrophobic) carbon surface. This is in contrast to boron nitride nanotubes which exhibit a constant surface conductance. Further, we measure the low frequency noise of the ionic current in CNTs and show that the amplitude of the noise scales with the surface charge, with data collapsing on a master curve for the various studied CNTs at a given p H .

Equilibrium concentration profiles and sedimentation kinetics of colloidal gels under gravitational stress

NASA Astrophysics Data System (ADS)

Buzzaccaro, S.; Secchi, E.; Brambilla, G.; Piazza, R.; Cipelletti, L.

2012-07-01

We study the sedimentation of colloidal gels by using a combination of light scattering, polarimetry and video imaging. The asymptotic concentration profiles φ(z,t → ∞) exhibit remarkable scaling properties: profiles for gels prepared at different initial volume fractions and particle interactions can be superimposed onto a single master curve by using suitable reduced variables. We show theoretically that this behavior stems from a power law dependence of the compressive elastic modulus versus φ, which we directly test experimentally. The sedimentation kinetics comprises an initial latency stage, followed by a rapid collapse where the gel height h decreases at constant velocity and a final compaction stage characterized by a stretched exponential relaxation of h toward a plateau. Analogies and differences with previous works are briefly discussed.

Pressure Effect on the Boson Peak in Deeply Cooled Confined Water: Evidence of a Liquid-Liquid Transition

DOE PAGES

Wang, Zhe; Kolesnikov, Alexander I.; Ito, Kanae; ...

2015-12-03

We studied the boson peak in deeply cooled water confined in nanopores in order to examine the liquid-liquid transition (LLT). Below ~180 K, the boson peaks at pressures P higher than ~3.5 kbar are evidently distinct from those at low pressures by higher mean frequencies and lower heights. Moreover, the higher-P boson peaks can be rescaled to a master curve while the lower-P boson peaks can be rescaled to a different one. Moreover, these phenomena agree with the existence of two liquid phases with different densities and local structures and the associated LLT in the measured (P, T) region. Additionally,more » the P dependence of the librational band also agrees with the above conclusion.« less

Strain-rate/temperature behavior of high density polyethylene in compression

NASA Technical Reports Server (NTRS)

Clements, L. L.; Sherby, O. D.

1978-01-01

The compressive strain rate/temperature behavior of highly linear, high density polyethylene was analyzed in terms of the predictive relations developed for metals and other crystalline materials. For strains of 5 percent and above, the relationship between applied strain rate, dotted epsilon, and resulting flow stress, sigma, was found to be: dotted epsilon exp times (Q sub f/RT) = k'(sigma/sigma sub c) to the nth power; the left-hand side is the activation-energy-compensated strain rate, where Q sub f is activation energy for flow, R is gas constant, and T is temperature; k is a constant, n is temperature-independent stress exponent, and sigma/sigma sub c is structure-compensated stress. A master curve resulted from a logarithmic plot of activation-energy-compensated strain rate versus structure-compensated stress.

[The visual perception of the elements of technical drawings among masking distractions in advanced and nonadvanced students in the building and architectural professions].

PubMed

Balichev, Iu

1997-01-01

To investigation were submitted the particularities of the process of visual perception of technical drawings and schemes in advanced and backward pupils, who were mastering the specialties of "building and architecture", "hydroconstruction", "transport construction", "geodesy". The time was registered, which was necessary to advanced and backward pupils for unveiling the different elements in the drawing, scheme, and such attributes of the drawing as: orientation, length, curves of the lined, the boundary between them; time for identification of the specific designations, symbols, group of symbols, elements of the sketch from the simple to the complex ones. The results of the investigations revealed that in the advanced pupils the perception (unveiling) of the different elements of the technical drawing proceeded very rapidly, almost automatically. In the backward pupils this process elapsed reliably more slowly. It was demonstrated that the growing up pupils, who were distinguished with more rapid perception of the different elements of the drawing (advanced ones) more rapidly and more exactly dealt with solution of the technical tasks as compared with these, who more slowly unveiled the looked for elements (backwardness). Some other individual particularities were also established with respect to the visual perception of the elements of the technical drawing and its properties in advanced and backward pupils who were mastering the investigated professions.

Robotic invasion of operation theatre and associated anaesthetic issues: A review.

PubMed

Kakar, Prem N; Das, Jyotirmoy; Roy, Preeti Mittal; Pant, Vijaya

2011-01-01

A Robotic device is a powered, computer controlled manipulator with artificial sensing that can be reprogrammed to move and position tools to carry out a wide range of tasks. Robots and Telemanipulators were first developed by the National Aeronautics and Space Administration (NASA) for use in space exploration. Today's medical robotic systems were the brainchild of the United States Department of Defence's desire to decrease war casualties with the development of 'telerobotic surgery'. The 'master-slave' telemanipulator concept was developed for medical use in the early 1990s where the surgeon's (master) manual movements were transmitted to end-effector (slave) instruments at a remote site. Since then, the field of surgical robotics has undergone massive transformation and the future is even brighter. As expected, any new technique brings with it risks and the possibility of technical difficulties. The person who bears the brunt of complications or benefit from a new invention is the 'Patient'. Anaesthesiologists as always must do their part to be the patient's 'best man' in the perioperative period. We should be prepared for screening and selection of patients in a different perspective keeping in mind the steep learning curves of surgeons, long surgical hours, extreme patient positioning and other previously unknown anaesthetic challenges brought about by the surgical robot. In this article we have tried to track the development of surgical robots and consider the unique anaesthetic issues related to robot assisted surgeries.

Can the pre-operative Western Ontario and McMaster score predict patient satisfaction following total hip arthroplasty?

PubMed

Rogers, B A; Alolabi, B; Carrothers, A D; Kreder, H J; Jenkinson, R J

2015-02-01

In this study we evaluated whether pre-operative Western Ontario and McMaster Universities (WOMAC) osteoarthritis scores can predict satisfaction following total hip arthroplasty (THA). Prospective data for a cohort of patients undergoing THA from two large academic centres were collected, and pre-operative and one-year post-operative WOMAC scores and a 25-point satisfaction questionnaire were obtained for 446 patients. Satisfaction scores were dichotomised into either improvement or deterioration. Scatter plots and Spearman's rank correlation coefficient were used to describe the association between pre-operative WOMAC and one-year post-operative WOMAC scores and patient satisfaction. Satisfaction was compared using receiver operating characteristic (ROC) analysis against pre-operative, post-operative and δ WOMAC scores. We found no relationship between pre-operative WOMAC scores and one-year post-operative WOMAC or satisfaction scores, with Spearman's rank correlation coefficients of 0.16 and -0.05, respectively. The ROC analysis showed areas under the curve (AUC) of 0.54 (pre-operative WOMAC), 0.67 (post-operative WOMAC) and 0.43 (δ WOMAC), respectively, for an improvement in satisfaction. We conclude that the pre-operative WOMAC score does not predict the post-operative WOMAC score or patient satisfaction after THA, and that WOMAC scores can therefore not be used to prioritise patient care. ©2015 The British Editorial Society of Bone & Joint Surgery.

Derivative based sensitivity analysis of gamma index

PubMed Central

Sarkar, Biplab; Pradhan, Anirudh; Ganesh, T.

2015-01-01

Originally developed as a tool for patient-specific quality assurance in advanced treatment delivery methods to compare between measured and calculated dose distributions, the gamma index (γ) concept was later extended to compare between any two dose distributions. It takes into effect both the dose difference (DD) and distance-to-agreement (DTA) measurements in the comparison. Its strength lies in its capability to give a quantitative value for the analysis, unlike other methods. For every point on the reference curve, if there is at least one point in the evaluated curve that satisfies the pass criteria (e.g., δDD = 1%, δDTA = 1 mm), the point is included in the quantitative score as “pass.” Gamma analysis does not account for the gradient of the evaluated curve - it looks at only the minimum gamma value, and if it is <1, then the point passes, no matter what the gradient of evaluated curve is. In this work, an attempt has been made to present a derivative-based method for the identification of dose gradient. A mathematically derived reference profile (RP) representing the penumbral region of 6 MV 10 cm × 10 cm field was generated from an error function. A general test profile (GTP) was created from this RP by introducing 1 mm distance error and 1% dose error at each point. This was considered as the first of the two evaluated curves. By its nature, this curve is a smooth curve and would satisfy the pass criteria for all points in it. The second evaluated profile was generated as a sawtooth test profile (STTP) which again would satisfy the pass criteria for every point on the RP. However, being a sawtooth curve, it is not a smooth one and would be obviously poor when compared with the smooth profile. Considering the smooth GTP as an acceptable profile when it passed the gamma pass criteria (1% DD and 1 mm DTA) against the RP, the first and second order derivatives of the DDs (δD’, δD”) between these two curves were derived and used as the boundary values for evaluating the STTP against the RP. Even though the STTP passed the simple gamma pass criteria, it was found failing at many locations when the derivatives were used as the boundary values. The proposed derivative-based method can identify a noisy curve and can prove to be a useful tool for improving the sensitivity of the gamma index. PMID:26865761