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.

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.

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.

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.

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

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.

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.

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

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.

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.

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.

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.

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.

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.

Volcanic facies architecture of an intra-arc strike-slip basin, Santa Rita Mountains, Southern Arizona

NASA Astrophysics Data System (ADS)

Busby, Cathy J.; Bassett, Kari N.

2007-09-01

The three-dimensional arrangement of volcanic deposits in strike-slip basins is not only the product of volcanic processes, but also of tectonic processes. We use a strike-slip basin within the Jurassic arc of southern Arizona (Santa Rita Glance Conglomerate) to construct a facies model for a strike-slip basin dominated by volcanism. This model is applicable to releasing-bend strike-slip basins, bounded on one side by a curved and dipping strike-slip fault, and on the other by curved normal faults. Numerous, very deep unconformities are formed during localized uplift in the basin as it passes through smaller restraining bends along the strike-slip fault. In our facies model, the basin fill thins and volcanism decreases markedly away from the master strike-slip fault (“deep” end), where subsidence is greatest, toward the basin-bounding normal faults (“shallow” end). Talus cone-alluvial fan deposits are largely restricted to the master fault-proximal (deep) end of the basin. Volcanic centers are sited along the master fault and along splays of it within the master fault-proximal (deep) end of the basin. To a lesser degree, volcanic centers also form along the curved faults that form structural highs between sub-basins and those that bound the distal ends of the basin. Abundant volcanism along the master fault and its splays kept the deep (master fault-proximal) end of the basin overfilled, so that it could not provide accommodation for reworked tuffs and extrabasinally-sourced ignimbrites that dominate the shallow (underfilled) end of the basin. This pattern of basin fill contrasts markedly with that of nonvolcanic strike-slip basins on transform margins, where clastic sedimentation commonly cannot keep pace with subsidence in the master fault-proximal end. Volcanic and subvolcanic rocks in the strike-slip basin largely record polygenetic (explosive and effusive) small-volume eruptions from many vents in the complexly faulted basin, referred to here as multi-vent complexes. Multi-vent complexes like these reflect proximity to a continuously active fault zone, where numerous strands of the fault frequently plumb small batches of magma to the surface. Releasing-bend extension promotes small, multivent styles of volcanism in preference to caldera collapse, which is more likely to form at releasing step-overs along a strike-slip fault.

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.

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.

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

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.

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

Modelling of Asphalt Concrete Stiffness in the Linear Viscoelastic Region

NASA Astrophysics Data System (ADS)

Mazurek, Grzegorz; Iwański, Marek

2017-10-01

Stiffness modulus is a fundamental parameter used in the modelling of the viscoelastic behaviour of bituminous mixtures. On the basis of the master curve in the linear viscoelasticity range, the mechanical properties of asphalt concrete at different loading times and temperatures can be predicted. This paper discusses the construction of master curves under rheological mathematical models i.e. the sigmoidal function model (MEPDG), the fractional model, and Bahia and co-workers’ model in comparison to the results from mechanistic rheological models i.e. the generalized Huet-Sayegh model, the generalized Maxwell model and the Burgers model. For the purposes of this analysis, the reference asphalt concrete mix (denoted as AC16W) intended for the binder coarse layer and for traffic category KR3 (5×105

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

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.

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.

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.

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.

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...

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.

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.

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.

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...

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.

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.

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.

Fracture toughness testing of Linde 1092 reactor vessel welds in the transition range using Charpy-sized specimens

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

Pavinich, W.A.; Yoon, K.K.; Hour, K.Y.

1999-10-01

The present reference toughness method for predicting the change in fracture toughness can provide over estimates of these values because of uncertainties in initial RT{sub NDT} and shift correlations. It would be preferable to directly measure fracture toughness. However, until recently, no standard method was available to characterize fracture toughness in the transition range. ASTM E08 has developed a draft standard that shows promise for providing lower bound transition range fracture toughness using the master curve approach. This method has been successfully implemented using 1T compact fracture specimens. Combustion Engineering reactor vessel surveillance programs do not have compact fracture specimens.more » Therefore, the CE Owners Group developed a program to validate the master curve method for Charpy-sized and reconstituted Charpy-sized specimens for future application on irradiated specimens. This method was validated for Linde 1092 welds using unirradiated Charpy-sized and reconstituted Charpy-sized specimens by comparison of results with those from compact fracture specimens.« less

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.

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.

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.

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%...

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.

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.

Master plot analysis of microcracking in graphite/epoxy and graphite/PEEK laminates

NASA Technical Reports Server (NTRS)

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

1993-01-01

We used a variational stress analysis and an energy release rate failure criterion to construct a master plot analysis of matrix microcracking. In the master plot, the results for all laminates of a single material are predicted to fall on a single line whose slope gives the microcracking toughness of the material. Experimental results from 18 different layups of AS4/3501-6 laminates show that the master plot analysis can explain all observations. In particular, it can explain the differences between microcracking of central 90 deg plies and of free-surface 90 deg plies. Experimental results from two different AS4/PEEK laminates tested at different temperatures can be explained by a modified master plot that accounts for changes in the residual thermal stresses. Finally, we constructed similar master plot analyses for previous literature microcracking models. All microcracking theories that ignore the thickness dependence of the stresses gave poor results.

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.

Fractional calculus applied to the analysis of spectral electrical conductivity of clay-water system.

PubMed

Korosak, Dean; Cvikl, Bruno; Kramer, Janja; Jecl, Renata; Prapotnik, Anita

2007-06-16

The analysis of the low-frequency conductivity spectra of the clay-water mixtures is presented. The frequency dependence of the conductivity is shown to follow the power-law with the exponent n=0.67 before reaching the frequency-independent part. When scaled with the value of the frequency-independent part of the spectrum the conductivity spectra for samples at different water content values are shown to fit to a single master curve. It is argued that the observed conductivity dispersion is a consequence of the anomalously diffusing ions in the clay-water system. The fractional Langevin equation is then used to describe the stochastic dynamics of the single ion. The results indicate that the experimentally observed dielectric properties originate in anomalous ion transport in clay-water system characterized with time-dependent diffusion coefficient.

Viscoelastic characterization of thin-film polymers exposed to low Earth orbit

NASA Technical Reports Server (NTRS)

Letton, Alan; Farrow, Allan; Strganac, Thomas

1993-01-01

The materials made available through the Long Duration Exposure Facility (LDEF) satellite provide a set of specimens that can be well characterized and have a known exposure history with reference to atomic oxygen and ultraviolet radiation exposure. Mechanical characteristics measured from control samples and exposed samples provide a data base for predicting the behavior of polymers in low earth orbit. Samples of 1.0 mil thick low density polyethylene were exposed to the low earth orbit environment for a period of six years. These materials were not directly exposed to ram atomic oxygen and offer a unique opportunity for measuring the effect of atomic oxygen and UV radiation on mechanical properties with little concern to the effect of erosion. The viscoelastic characteristics of these materials were measured and compared to the viscoelastic characteristics of control samples. To aid in differentiating the effects of changes in crystallinity resulting from thermal cycling, from the effects of changes in chemical structure resulting from atomic oxygen/UV attack to the polymer, a second set of control specimens, annealed to increase crystallinity, were measured as well. The resulting characterization of these materials will offer insight into the impact of atomic oxygen/UV on the mechanical properties of polymeric materials. The viscoelastic properties measured for the control, annealed, and exposed specimens were the storage and loss modulus as a function of frequency and temperature. From these datum is calculated the viscoelastic master curve derived using the principle of time/temperature superposition. Using the master curve, the relaxation modulus is calculated using the method of Ninomiya and Ferry. The viscoelastic master curve and the stress relaxation modulus provide a direct measure of the changes in the chemical or morphological structure. In addition, the effect of these changes on long-term and short-term mechanical properties is known directly. It should be noted that the dependence on directionality for the polymer films was considered since these films were manufactured by a blown-film process.

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.

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.

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.

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.

Trends in Distance Education: A Content Analysis of Master's Thesis

ERIC Educational Resources Information Center

Durak, Gürhan; Çankaya, Serkan; Yunkul, Eyup; Urfa, Mehmet; Toprakliklioglu, Kivanç; Arda, Yagmur; Inam, Nazmiye

2017-01-01

The present study aimed at presenting the results of content analysis on Master's Theses carried out in the field of distance education at higher education level in Turkey between 1986 and 2015. A total of 285 Master's Theses were examined to determine the key words, academic disciplines, research areas, theoretical frameworks, research designs…

Pressure Pulsation in a High Head Francis Turbine Operating at Variable Speed

NASA Astrophysics Data System (ADS)

Sannes, D. B.; Iliev, I.; Agnalt, E.; Dahlhaug, O. G.

2018-06-01

This paper presents the preliminary work of the master thesis of the author, written at the Norwegian University of Science and Technology. Today, many Francis turbines experience formations of cracks in the runner due to pressure pulsations. This can eventually cause failure. One way to reduce this effect is to change the operation point of the turbine, by utilizing variable speed technology. This work presents the results from measurements of the Francis turbine at the Waterpower Laboratory at NTNU. Measurements of pressure pulsations and efficiency were done for the whole operating range of a high head Francis model turbine. The results will be presented in a similar diagram as the Hill Chart, but instead of constant efficiency curves there will be curves of constant peak-peak values. This way, it is possible to find an optimal operation point for the same power production, were the pressure pulsations are at its lowest. Six points were chosen for further analysis to instigate the effect of changing the speed by ±50 rpm. The analysis shows best results for operation below BEP when the speed was reduced. The change in speed also introduced the possibility to have other frequencies in the system. It is therefore important avoid runner speeds that can cause resonance in the system.

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.

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.

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.

A master manipulator with a remote-center-of-motion kinematic structure for a minimally invasive robotic surgical system.

PubMed

Lee, Hyunyoung; Cheon, Byungsik; Hwang, Minho; Kang, Donghoon; Kwon, Dong-Soo

2018-02-01

In robotic surgical systems, commercial master devices have limitations owing to insufficient workspace and lack of intuitiveness. To overcome these limitations, a remote-center-of-motion (RCM) master manipulator was proposed. The feasibility of the proposed RCM structure was evaluated through kinematic analysis using a conventional serial structure. Two performance comparison experiments (peg transfer task and objective transfer task) were conducted for the developed master and Phantom Omni. The kinematic analysis results showed that compared with the serial structure, the proposed RCM structure has better performance in terms of design efficiency (19%) and workspace quality (59.08%). Further, in comparison with Phantom Omni, the developed master significantly increased task efficiency and significantly decreased workload in both experiments. The comparatively better performance in terms of intuitiveness, design efficiency, and operability of the proposed master for a robotic system for minimally invasive surgery was confirmed through kinematic and experimental analysis. Copyright © 2017 John Wiley & Sons, Ltd.

A Discourse Analysis of Master's Theses across Disciplines with a Focus on Introductions

ERIC Educational Resources Information Center

Samraj, Betty

2008-01-01

There have been a growing number of discourse studies in recent years on written academic genres produced by students. However, the master's thesis has not received as much attention as the PhD dissertation. This investigation of master's theses from three disciplines, biology, philosophy and linguistics, employs both discourse analysis and…

Who wants to enroll in health care PhD programs? An analysis of a nationwide graduate destination survey.

PubMed

Pan, Ying-Ju; Lee, Lung-Sheng

2012-06-01

PhD training is important for national human resource development in the era of the "knowledge economy". However, it is not clear what factors are associated with the decision of a master's degree graduate to pursue a PhD degree in health care, including medicine, public health, and nursing. It is postulated that the intention to pursue a PhD degree in health care is associated with a graduate's attributes, academic publication, socioeconomic status, and extent of financial support. A cross-sectional investigation was conducted to analyze data from the 2007 nationwide graduate destination survey in Taiwan. Logistic regression with a forward stepwise model selection strategy was applied to identify those significant factors related to the intention of master's degree graduates to pursue a PhD degree in health care. The predictive validity of the selected model was evaluated using the receiver operating characteristics curve analysis. Of the 1668 master's degree graduates who responded to the survey, only 240 (14.4%) indicated a desire to pursue a PhD degree. Seven factors are identified to be independently associated with the intention to pursue a PhD degree in health care, including female gender [odds ratio (OR)=0.18, 95% confidence interval: 0.13-0.26], more than 2 years in graduate school (OR=0.46), working during graduate school (OR=0.47), submission of conference and journal articles (OR=1.61 and 1.48, respectively), tuition source, and parents' educational level. The predictive validity of the selected model was 0.77. These findings provide an overview of potential PhD students in the field of health care. Based on this assessment, effective strategies need to be developed to attract and retain qualified candidates, as well as other types of PhD students who are in demand in this field. Copyright © 2012. Published by Elsevier B.V.

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.

Development and Comparison of a Rapid Isothermal Nucleic Acid Amplification Test for Typing of Herpes Simplex Virus Types 1 and 2 on a Portable Fluorescence Detector

PubMed Central

Tong, Yanhong; McCarthy, Kaitlin; Kong, Huimin; Lemieux, Bertrand

2013-01-01

We have developed a rapid and simple molecular test, the IsoGlow HSV Typing assay, for the detection and typing of herpes simplex virus (type 1 and 2) from genital or oral lesions. Clinical samples suspended in viral transport mediums are simply diluted and then added to a helicase-dependent amplification master mix. The amplification and detection were performed on a portable fluorescence detector called the FireFly instrument. Detection of amplification products is based on end-point analysis using cycling probe technology. An internal control nucleic acid was included in the amplification master mix to monitor the presence of amplification inhibitors in the samples. Because the device has only two fluorescence detection channels, two strategies were developed and compared to detect the internal control template: internal control detected by melting curve analysis using a dual-labeled probe, versus internal control detection using end-point fluorescence release by a CPT probe at a lower temperature. Both have a total turnaround time of about 1 hour. Clinical performance relative to herpes viral culture was evaluated using 176 clinical specimens. Both formats of the IsoGlow HSV typing assay had sensitivities comparable to that of the Food and Drug Administration–cleared IsoAmp HSV (BioHelix Corp., Beverly MA) test and specificity for the two types of HSV comparable to that of ELVIS HSV (Diagnostic Hybrids, Athens, OH). PMID:22951487

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.

Why Bother about Writing a Masters Dissertation? Assumptions of Faculty and Masters Students in an Iranian Setting

ERIC Educational Resources Information Center

Hasrati, Mostafa

2013-01-01

This article reports the results of a mixed methodology analysis of the assumptions of academic staff and Masters students in an Iranian university regarding various aspects of the assessment of the Masters degree thesis, including the main objective for writing the thesis, the role of the students, supervisors and advisors in writing the…

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

Near-peer mentorship for undergraduate training in Ugandan medical schools: views of undergraduate students

PubMed Central

Rukundo, Godfrey Zari; Burani, Aluonzi; Kasozi, Jannat; Kirimuhuzya, Claude; Odongo, Charles; Mwesigwa, Catherine; Byona, Wycliff; Kiguli, Sarah

2016-01-01

Introduction Masters Students are major stakeholders in undergraduate medical education but their contribution has not been documented in Uganda. The aim of the study was to explore and document views and experiences of undergraduate students regarding the role of masters students as educators in four Ugandan medical schools. Methods This was a cross-sectional descriptive study using qualitative data collection methods. Eight Focus Group Discussions were conducted among eighty one selected preclinical and clinical students in the consortium of four Ugandan medical schools: Mbarara University of Science and Technology, Makerere College of Health Sciences, Gulu University and Kampala International University, Western Campus. Data analysis was done using thematic analysis. Participants’ privacy and confidentiality were respected and participant identifiers were not included in data analysis. Results Undergraduate students from all the medical schools viewed the involvement of master's students as very important. Frequent contact between masters and undergraduate students was reported as an important factor in undergraduate students’ motivation and learning. Despite the useful contribution, master’ students face numerous challenges like heavy workload and conflicting priorities. Conclusion According to undergraduate students in Ugandan medical schools, involvement of master's students in the teaching and learning of undergraduate students is both useful and challenging to masters and undergraduate students. Masters students provide peer mentorship to the undergraduate students. The senior educators are still needed to do their work and also to support the master's students in their teaching role. PMID:27347289

Hydrograph monitoring and analysis for sustainable karst water management in Nyadeng Spring, East Borneo

NASA Astrophysics Data System (ADS)

Widyastuti, M.; Fatchurohman, H.; Fathoni, W. A.; Hakim, A. A.; Haryono, E.

2018-04-01

Karst aquifer stores abundant water resources within its matrix, conduits, and intergranular pores. Karst aquifer plays an important role in providing water supply, especially in the areas nearby that commonly dry and lack of surface water resources. Karst spring hydrograph analysis is very fundamental step to–assess and determines the condition of the catchment area in karst terrain. Recession curve is believed to be the most stable part in single flood hydrograph that represents the aquifer characteristics. Nyadeng is one of the most significant karst springs that located in Merabu Karst Area, East Borneo. Villagers in Merabu highly depend on Nyadeng Spring for fulfilled their freshwater need. Hydrograph monitoring has been initiated for one year in Nyadeng Spring as a preliminary action for karst water management in Merabu. Water level data series obtained using automatic water level data logger and then correlated with manual discharge measurement to generate stage-discharge rating curve. The stage-discharge rating curve formula for Nyadeng Spring calculated as y = 0,0102e5,8547x with r2 value = 0.8759. From the combination of several single flood events, Master Recession Curve (MRC) was generated to determine flow regime as the main consideration for karstification degree calculation. From the MRC result, flow regimes formula determined as Qt = 3.2-0.001t + 1.2(1-0.012t)+1.6(1-0.035t) indicated that one sub-regime with laminar flow and two sub-regimes with turbulent flow existed. From the MRC formula, the degree of karstification in Nyadeng Spring classified at seventh scale (developed karstification of the aquifer) based on Malik’s karstification degree (2012). The degree of karstification in Nyadeng Spring indicates that the aquifer formed by large conduit channels, fissures, and macro fissures which are able to provide significant water sources that can be utilized for multi purposes. Therefore, it is concluded that spring hydrograph monitoring provide essential information in order to establish a careful water resources management actions.

Baseflow index assessment and master recession curve analysis for karst water management in Kakap Spring, Gunung Sewu

NASA Astrophysics Data System (ADS)

Fatchurohman, H.; Adji, T. N.; Haryono, E.; Wijayanti, P.

2018-04-01

Karst terrain occurs in combination of high solubility rock and well developed secondary porosity. Over the time, groundwater resources have not been well managed including karst aquifers. Karst aquifers formed in a very complex hydrological system. Developed in fracture media and soluble rocks have led karst aquifers into various porosity types and aquifer properties. Karst spring hydrograph is an essential element for water resource management. The form of karst spring hydrograph reflects the aquifer characteristics. The shapes of flood discharge hydrographs represent aquifer responses to recharge and contain information about the interior condition of karst drainage basin. Every year, Gunung Sewu karst area is suffering to severe water scarcity. The development of sub-terrain drainage networks lead into the minimum surface water resources. Kakap Spring is perennial gravity spring that located adjacently to the border of Gunung Sewu and the alluvial formation of Baturetno. Kakap spring play vital role regarding water supply in Giriwoyo sub-district as the spring fulfill most of the water needs in Giriwoyo sub-district. Kakap Spring utilized by the local authorities as the main source for pipeline water and distributed to the households. Water level data series obtained using automatic water level data logger and then correlated with manual discharge measurement to generate stage-discharge rating curve. The stage-discharge rating curve formula for Kakap Spring calculated as y = 14,504e8,9763x with r2 value = 0.8582. From the MRC result, flow regimes formula determined as + 400 (1-0,005t) + 700 (1-0,01t)., indicated that the aquifer dominated by turbulent flow regime. From the MRC formula, the degree of karstification in Kakap Spring classified at eighth scale. The average baseflow index in Kakap Spring calculated using recession curve analysis with the BFI index = 0,7485.

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.

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

Buckling Analysis for Stiffened Anisotropic Circular Cylinders Based on Sanders Nonlinear Shell Theory

NASA Technical Reports Server (NTRS)

Nemeth, Michael P.

2014-01-01

Nonlinear and bifurcation buckling equations for elastic, stiffened, geometrically perfect, right-circular cylindrical, anisotropic shells subjected to combined loads are presented that are based on Sanders' shell theory. Based on these equations, a three-parameter approximate Rayleigh-Ritz solution and a classical solution to the buckling problem are presented for cylinders with simply supported edges. Extensive comparisons of results obtained from these solutions with published results are also presented for a wide range of cylinder constructions. These comparisons include laminated-composite cylinders with a wide variety of shell-wall orthotropies and anisotropies. Numerous results are also given that show the discrepancies between the results obtained by using Donnell's equations and variants of Sanders' equations. For some cases, nondimensional parameters are identified and "master" curves are presented that facilitate the concise representation of results.

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.

A search for periodicity in the x ray spectrum of black hole candidate A0620-00

NASA Technical Reports Server (NTRS)

Clark, George W.; Plaks, Kenneth

1991-01-01

The archived data from the SAS-3 observations of the X-ray nova A0620-00, the best of the stellar blackhole candidates, were exhaustively examined for evidence of variable phenomena correlated with the orbital motion of the binary system of which it is a member. The original analysis of these data was completed before discovery of the binary companion and determination of the orbital period of the system. New interest was drawn to the task of a reexamination of the archive data by the recent discovery of the massive nature of the X-ray source through analysis of the Doppler variations and ellipsoidal light variations of the faint K-star companion by McClintock and Remillard. The archive research, carried out under the supervision of the principal investigator, was the topic of the thesis submitted to the MIT Department of Physics by Kenneth Plaks in partial fulfillment of the requirements for the degree of Master of Science. Plaks' effort was focused on the elimination of fluctuations in the data due to errors in attitude solutions and other extraneous causes. The first products of his work were long-term light curves of the X-ray intensities in the various energy channels as functions of time during the time from outbursts in August 1975 to quiescence approximately 6 months later. These curves, are refined versions of the preliminary results published in 1976 (Matilsky et al. 1976). Smooth exponentials were fitted to these long term light curves to provide the basis for detrending the data, thereby permitting a calculation of residuals derived by subtracting the fitted curve from the data. The residuals were then analyzed by Fourier analysis to search for variations with the period of the binary orbit, namely 7.75 hours. No evidence of an orbital periodicity was found. However, the refined light curve provides a much clearer picture of the outburst and subsequent decay of the X-ray luminosity. In fact, there were two outbursts, each followed by an exponential decay with similar time constants of about 25 days. Previous evidence of a three-oscillation variation with a 7.8 day period were confirmed. Substantial theoretical effort has been devoted to attempts to account for the decay characteristics as the result of the gradual eating up of an accretion disk by a stellar-mass blackhole (e.g., Huang and Wheeler 1989). The improved decay curves will provide significant new constraints on the theoretical analyses.

Creep-rupture reliability analysis

NASA Technical Reports Server (NTRS)

Peralta-Duran, A.; Wirsching, P. H.

1984-01-01

A probabilistic approach to the correlation and extrapolation of creep-rupture data is presented. Time temperature parameters (TTP) are used to correlate the data, and an analytical expression for the master curve is developed. The expression provides a simple model for the statistical distribution of strength and fits neatly into a probabilistic design format. The analysis focuses on the Larson-Miller and on the Manson-Haferd parameters, but it can be applied to any of the TTP's. A method is developed for evaluating material dependent constants for TTP's. It is shown that optimized constants can provide a significant improvement in the correlation of the data, thereby reducing modelling error. Attempts were made to quantify the performance of the proposed method in predicting long term behavior. Uncertainty in predicting long term behavior from short term tests was derived for several sets of data. Examples are presented which illustrate the theory and demonstrate the application of state of the art reliability methods to the design of components under creep.

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.

Mechanical relaxation in a Zr-based bulk metallic glass: Analysis based on physical models

NASA Astrophysics Data System (ADS)

Qiao, J. C.; Pelletier, J. M.

2012-08-01

The mechanical relaxation behavior in a Zr55Cu30Ni5Al10 bulk metallic glass is investigated by dynamic mechanical analysis in both temperature and frequency domains. Master curves can be obtained for the storage modulus G' and for the loss modulus G'', confirming the validity of the time-temperature superposition principle. Different models are discussed to describe the main (α) relaxation, e.g., Debye model, Havriliak-Negami (HN) model, Kohlrausch-Williams-Watt (KWW) model, and quasi-point defects (QPDs) model. The main relaxation in bulk metallic glass cannot be described using a single relaxation time. The HN model, the KWW model, and the QPD theory can be used to fit the data of mechanical spectroscopy experiments. However, unlike the HN model and the KWW model, some physical parameters are introduced in QPD model, i.e., atomic mobility and correlation factor, giving, therefore, a new physical approach to understand the mechanical relaxation in bulk metallic glasses.

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.

Kinetic analysis of overlapping multistep thermal decomposition comprising exothermic and endothermic processes: thermolysis of ammonium dinitramide.

PubMed

Muravyev, Nikita V; Koga, Nobuyoshi; Meerov, Dmitry B; Pivkina, Alla N

2017-01-25

This study focused on kinetic modeling of a specific type of multistep heterogeneous reaction comprising exothermic and endothermic reaction steps, as exemplified by the practical kinetic analysis of the experimental kinetic curves for the thermal decomposition of molten ammonium dinitramide (ADN). It is known that the thermal decomposition of ADN occurs as a consecutive two step mass-loss process comprising the decomposition of ADN and subsequent evaporation/decomposition of in situ generated ammonium nitrate. These reaction steps provide exothermic and endothermic contributions, respectively, to the overall thermal effect. The overall reaction process was deconvoluted into two reaction steps using simultaneously recorded thermogravimetry and differential scanning calorimetry (TG-DSC) curves by considering the different physical meanings of the kinetic data derived from TG and DSC by P value analysis. The kinetic data thus separated into exothermic and endothermic reaction steps were kinetically characterized using kinetic computation methods including isoconversional method, combined kinetic analysis, and master plot method. The overall kinetic behavior was reproduced as the sum of the kinetic equations for each reaction step considering the contributions to the rate data derived from TG and DSC. During reproduction of the kinetic behavior, the kinetic parameters and contributions of each reaction step were optimized using kinetic deconvolution analysis. As a result, the thermal decomposition of ADN was successfully modeled as partially overlapping exothermic and endothermic reaction steps. The logic of the kinetic modeling was critically examined, and the practical usefulness of phenomenological modeling for the thermal decomposition of ADN was illustrated to demonstrate the validity of the methodology and its applicability to similar complex reaction processes.

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

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.

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

Development and comparison of a rapid isothermal nucleic acid amplification test for typing of herpes simplex virus types 1 and 2 on a portable fluorescence detector.

PubMed

Tong, Yanhong; McCarthy, Kaitlin; Kong, Huimin; Lemieux, Bertrand

2012-11-01

We have developed a rapid and simple molecular test, the IsoGlow HSV Typing assay, for the detection and typing of herpes simplex virus (type 1 and 2) from genital or oral lesions. Clinical samples suspended in viral transport mediums are simply diluted and then added to a helicase-dependent amplification master mix. The amplification and detection were performed on a portable fluorescence detector called the FireFly instrument. Detection of amplification products is based on end-point analysis using cycling probe technology. An internal control nucleic acid was included in the amplification master mix to monitor the presence of amplification inhibitors in the samples. Because the device has only two fluorescence detection channels, two strategies were developed and compared to detect the internal control template: internal control detected by melting curve analysis using a dual-labeled probe, versus internal control detection using end-point fluorescence release by a CPT probe at a lower temperature. Both have a total turnaround time of about 1 hour. Clinical performance relative to herpes viral culture was evaluated using 176 clinical specimens. Both formats of the IsoGlow HSV typing assay had sensitivities comparable to that of the Food and Drug Administration-cleared IsoAmp HSV (BioHelix Corp., Beverly MA) test and specificity for the two types of HSV comparable to that of ELVIS HSV (Diagnostic Hybrids, Athens, OH). Copyright © 2012 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

Comparative Analysis of Master of Industrial Design Education in Turkey

ERIC Educational Resources Information Center

Erkarslan, Onder; Imamogullari, Beril

2010-01-01

This research focused on the masters degree programme in industrial design (ID), which is research and practice oriented in the light of current themes and design principles. It argued that a masters degree in industrial design would help graduates specialise in the related field and improve their skills. Therefore, institutional and academic…

Compilation of Theses Abstracts

DTIC Science & Technology

2004-12-01

Lieutenant, United States Navy Master of Business Administration–December 2004 Jonathan C. Byrom–Captain, United States Army Master of Business...Hyperspectral Imagery, Principal Components Analysis, Minimum Noise Transform ALTERNATE CONFIGURATIONS FOR BLOCKED-IMPURITY-BAND DETECTORS Jonathan C...Yew Sing Quek –Captain, Republic of Singapore Armed Forces B.E., Nanyang Technological University-Singapore, 1999 Master of Science in Combat

MASTER ANALYTICAL SCHEME FOR ORGANIC COMPOUNDS IN WATER: PART 1. PROTOCOLS

EPA Science Inventory

A Master Analytical Scheme (MAS) has been developed for the analysis of volatile (gas chromatographable) organic compounds in water. In developing the MAS, it was necessary to evaluate and modify existing analysis procedures and develop new techniques to produce protocols that pr...

APPLICATION OF THE MASTER ANALYTICAL SCHEME TO POLAR ORGANICS IN DRINKING WATER

EPA Science Inventory

EPA's Master Analytical Scheme (MAS) for Organic Compounds in Water provides for comprehensive qualitative-quantitative analysis of gas chromatographable organics in many types of water. The paper emphasizes the analysis of polar and ionic organics, the more water soluble compoun...

Application of Item Analysis to Assess Multiple-Choice Examinations in the Mississippi Master Cattle Producer Program

ERIC Educational Resources Information Center

Parish, Jane A.; Karisch, Brandi B.

2013-01-01

Item analysis can serve as a useful tool in improving multiple-choice questions used in Extension programming. It can identify gaps between instruction and assessment. An item analysis of Mississippi Master Cattle Producer program multiple-choice examination responses was performed to determine the difficulty of individual examinations, assess the…

Conjoint Analysis: A Tool for Designing Degree Programs.

ERIC Educational Resources Information Center

Martin, John; Moore, Thomas E.

1993-01-01

Conjoint analysis, commonly used in product development, was used to determine the graduate education needs and program preferences of business administration graduates. Results suggest an accelerated and abbreviated Master's in Business Administration would be preferred to an master's degree, without detracting from existing programs or being…

MASTER ANALYTICAL SCHEME FOR ORGANIC COMPOUNDS IN WATER. PART 2. APPENDICES TO PROTOCOLS

EPA Science Inventory

A Master Analytical Scheme (MAS) has been developed for the analysis of volatile (gas chromatographable) organic compounds in water. In developing the MAS, it was necessary to evaluate and modify existing analysis procedures and develop new techniques to produce protocols that pr...

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.

Mechanical relaxations of a Cu60Zr40 metallic glass studied by using a dynamic mechanical analysis

NASA Astrophysics Data System (ADS)

Jeong, H. T.; Park, C. O.

2013-03-01

The mechanical relaxation behaviors of a Cu60Zr40 metallic glass were investigated by using isothermal multi-frequency dynamic mechanical measurements. From the spectra of the elastic moduli, master curves were constructed using the time-temperature superposition principle. The temperature dependence of the shift factor was found to follow the Arrhenius relationship in two temperature regions, one below and the other above the glass transition temperature ( T g ), and the activation energies for low-temperature relaxation and viscous flow were 32.7 kJ/mol and 307.1 kJ/mol, respectively. The decoupling of these two relaxations, shown in the temperature dependent plot of the shift factor, manifests the dynamic glass transition temperature region of the Cu60Zr40 metallic glass. From the temperature dependence of the shift factor, the fragility index of this alloy was also estimated.

Scaling for hard-sphere colloidal glasses near jamming

NASA Astrophysics Data System (ADS)

Zargar, Rojman; DeGiuli, Eric; Bonn, Daniel

2016-12-01

Hard-sphere colloids are model systems in which to study the glass transition and universal properties of amorphous solids. Using covariance matrix analysis to determine the vibrational modes, we experimentally measure here the scaling behavior of the density of states, shear modulus, and mean-squared displacement (MSD) in a hard-sphere colloidal glass. Scaling the frequency with the boson-peak frequency, we find that the density of states at different volume fractions all collapse on a single master curve, which obeys a power law in terms of the scaled frequency. Below the boson peak, the exponent is consistent with theoretical results obtained by real-space and phase-space approaches to understanding amorphous solids. We find that the shear modulus and the MSD are nearly inversely proportional, and show a singular power-law dependence on the distance from random close packing. Our results are in very good agreement with the theoretical predictions.

[Simulation in surgical training].

PubMed

Nabavi, A; Schipper, J

2017-01-01

Patient safety during operations hinges on the surgeon's skills and abilities. However, surgical training has come under a variety of restrictions. To acquire dexterity with decreasingly "simple" cases, within the legislative time constraints and increasing expectations for surgical results is the future challenge. Are there alternatives to traditional master-apprentice learning? A literature review and analysis of the development, implementation, and evaluation of surgical simulation are presented. Simulation, using a variety of methods, most important physical and virtual (computer-generated) models, provides a safe environment to practice basic and advanced skills without endangering patients. These environments have specific strengths and weaknesses. Simulations can only serve to decrease the slope of learning curves, but cannot be a substitute for the real situation. Thus, they have to be an integral part of a comprehensive training curriculum. Our surgical societies have to take up that challenge to ensure the training of future generations.

Trends in Exiting Physics Master's. Focus On

ERIC Educational Resources Information Center

Mulvey, Patrick J.; Nicholson, Starr

2014-01-01

A physics master's degree provides the recipient with a variety of career options. Some master's recipients will continue their education at the graduate level in physics or another field, where others enter the workforce pursuing a wide range of employment opportunities. This "Focus On" provides an in-depth analysis of physics…

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…

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

Clinical Study of the 3D-Master Color System among the Spanish Population.

PubMed

Gómez-Polo, Cristina; Gómez-Polo, Miguel; Martínez Vázquez de Parga, Juan Antonio; Celemín-Viñuela, Alicia

2017-01-12

To study whether the shades of the 3D-Master System were grouped and represented in the chromatic space according to the three-color coordinates of value, chroma, and hue. Maxillary central incisor color was measured on tooth surfaces through the Easyshade Compact spectrophotometer using 1361 participants aged between 16 and 89. The natural (not bleached teeth) color of the middle thirds was registered in the 3D-Master System nomenclature and in the CIELCh system. Principal component analysis and cluster analysis were applied. 75 colors of the 3D-Master System were found. The statistical analysis revealed the existence of 5 cluster groups. The centroid, the average of the 75 samples, in relation to lightness (L*) was 74.64, 22.87 for chroma (C*), and 88.85 for hue (h*). All of the clusters, except cluster 3, showed significant statistical differences with the centroid for the three-color coordinates (p <0.001). The results of this study indicated that 75 shades in the 3D-Master System were grouped into 5 clusters following coordinates L*, C*, and h* resulting from the dental spectrophotometer Vita Easyshade compact. The shades that composed each cluster did not belong to the same lightness color dimension groups. There was no special uniform chromatic distribution among the colors of the 3D-Master System. © 2017 by the American College of Prosthodontists.

Designing post-graduate Master's degree programs: the advanced training program in Dental Functional Analysis and Therapy as one example.

PubMed

Ratzmann, Anja; Ruge, Sebastian; Ostendorf, Kristin; Kordass, Bernd

2014-01-01

The decision to consolidate European higher education was reached by the Bologna Conference. Based on the Anglo-American system, a two-cycle degree program (Bachelor and Master) has been introduced. Subjects culminating in a state examination, such as Medicine and Dentistry, were excluded from this reform. Since the state examination is already comparable in its caliber to a Master's degree in Medicine or Dentistry, only advanced Master's degree programs with post-graduate specializations come into consideration for these subjects. In the field of dentistry numerous post-graduate study programs are increasingly coming into existence. Many different models and approaches are being pursued. Since the 2004-2005 winter semester, the University of Greifswald has offered the Master's degree program in Dental Functional Analysis and Therapy. Two and a half years in duration, this program is structured to allow program participation while working and targets licensed dentists who wish to attain certified skills for the future in state-of-the-art functional analysis and therapy. The design of this post-graduate program and the initial results of the evaluation by alumni are presented here. Our experiences show that the conceptual idea of an advanced Master's program has proved successful. The program covers a specialty which leads to increased confidence in handling challenging patient cases. The sharing of experiences among colleagues was evaluated as being especially important.

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.

Causal network analysis of head and neck keloid tissue identifies potential master regulators.

PubMed

Garcia-Rodriguez, Laura; Jones, Lamont; Chen, Kang Mei; Datta, Indrani; Divine, George; Worsham, Maria J

2016-10-01

To generate novel insights and hypotheses in keloid development from potential master regulators. Prospective cohort. Six fresh keloid and six normal skin samples from 12 anonymous donors were used in a prospective cohort study. Genome-wide profiling was done previously on the cohort using the Infinium HumanMethylation450 BeadChip (Illumina, San Diego, CA). The 190 statistically significant CpG islands between keloid and normal tissue mapped to 152 genes (P < .05). The top 10 statistically significant genes (VAMP5, ACTR3C, GALNT3, KCNAB2, LRRC61, SCML4, SYNGR1, TNS1, PLEKHG5, PPP1R13-α, false discovery rate <.015) were uploaded into the Ingenuity Pathway Analysis software's Causal Network Analysis (QIAGEN, Redwood City, CA). To reflect expected gene expression direction in the context of methylation changes, the inverse of the methylation ratio from keloid versus normal tissue was used for the analysis. Causal Network Analysis identified disease-specific master regulator molecules based on downstream differentially expressed keloid-specific genes and expected directionality of expression (hypermethylated vs. hypomethylated). Causal Network Analysis software identified four hierarchical networks that included four master regulators (pyroxamide, tributyrin, PRKG2, and PENK) and 19 intermediate regulators. Causal Network Analysis of differentiated methylated gene data of keloid versus normal skin demonstrated four causal networks with four master regulators. These hierarchical networks suggest potential driver roles for their downstream keloid gene targets in the pathogenesis of the keloid phenotype, likely triggered due to perturbation/injury to normal tissue. NA Laryngoscope, 126:E319-E324, 2016. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

Factors Mediating the Interactions between Adviser and Advisee during the Master's Thesis Project: A Quantitative Approach

ERIC Educational Resources Information Center

Rodrigues Jr., Jose Florencio; Lehmann, Angela Valeria Levay; Fleith, Denise De Souza

2005-01-01

Building on previous studies centred on the interaction between adviser and advisee in masters thesis projects, in which a qualitative approach was used, the present study uses factor analysis to identify the factors that determine either a successful or unsuccessful outcome for the masters thesis project. There were five factors relating to the…

The Limits of Master Narratives in History Textbooks: An Analysis of Representations of Martin Luther King, Jr.

ERIC Educational Resources Information Center

Alridge, Derrick P.

2006-01-01

In this study, I argue that American history textbooks present discrete, heroic, one-dimensional, and neatly packaged master narratives that deny students a complex, realistic, and rich understanding of people and events in American history. In making this argument, I examine the master narratives of Martin Luther King, Jr., in high school history…

LGBTQ Studies and Interdisciplinarity: A Citation Analysis of Master's Theses

ERIC Educational Resources Information Center

Graziano, Vince

2018-01-01

Emergent programs or newly established areas of study are often viewed as interdisciplinary. But how is interdisciplinarity defined or measured? The identification of research methods and the selection of objects of inquiry are significant elements in this definition. Citation analysis, however, also plays a role. Citation patterns in master's…

Local Citation Analysis of Graduate Biology Theses: Collection Development Implications

ERIC Educational Resources Information Center

Miller, Laura Newton

2011-01-01

This paper will focus on the citation analysis of graduate masters theses from Carleton University's Biology Department with implications for library collection management decisions. Twenty-five masters theses were studied to determine citation types and percentages, ranking of journals by frequency of citation and by number of authors citing, and…

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.

Updated Estimates of the Average Financial Return on Master's Degree Programs in the United States

ERIC Educational Resources Information Center

Gándara, Denisa; Toutkoushian, Robert K.

2017-01-01

In this study, we provide updated estimates of the private and social financial return on enrolling in a master's degree program in the United States. In addition to returns for all fields of study, we show estimated returns to enrolling in master's degree programs in business and education, specifically. We also conduct a sensitivity analysis to…

Synchronization Analysis of Master-Slave Probabilistic Boolean Networks.

PubMed

Lu, Jianquan; Zhong, Jie; Li, Lulu; Ho, Daniel W C; Cao, Jinde

2015-08-28

In this paper, we analyze the synchronization problem of master-slave probabilistic Boolean networks (PBNs). The master Boolean network (BN) is a deterministic BN, while the slave BN is determined by a series of possible logical functions with certain probability at each discrete time point. In this paper, we firstly define the synchronization of master-slave PBNs with probability one, and then we investigate synchronization with probability one. By resorting to new approach called semi-tensor product (STP), the master-slave PBNs are expressed in equivalent algebraic forms. Based on the algebraic form, some necessary and sufficient criteria are derived to guarantee synchronization with probability one. Further, we study the synchronization of master-slave PBNs in probability. Synchronization in probability implies that for any initial states, the master BN can be synchronized by the slave BN with certain probability, while synchronization with probability one implies that master BN can be synchronized by the slave BN with probability one. Based on the equivalent algebraic form, some efficient conditions are derived to guarantee synchronization in probability. Finally, several numerical examples are presented to show the effectiveness of the main results.

Synchronization Analysis of Master-Slave Probabilistic Boolean Networks

PubMed Central

Lu, Jianquan; Zhong, Jie; Li, Lulu; Ho, Daniel W. C.; Cao, Jinde

2015-01-01

In this paper, we analyze the synchronization problem of master-slave probabilistic Boolean networks (PBNs). The master Boolean network (BN) is a deterministic BN, while the slave BN is determined by a series of possible logical functions with certain probability at each discrete time point. In this paper, we firstly define the synchronization of master-slave PBNs with probability one, and then we investigate synchronization with probability one. By resorting to new approach called semi-tensor product (STP), the master-slave PBNs are expressed in equivalent algebraic forms. Based on the algebraic form, some necessary and sufficient criteria are derived to guarantee synchronization with probability one. Further, we study the synchronization of master-slave PBNs in probability. Synchronization in probability implies that for any initial states, the master BN can be synchronized by the slave BN with certain probability, while synchronization with probability one implies that master BN can be synchronized by the slave BN with probability one. Based on the equivalent algebraic form, some efficient conditions are derived to guarantee synchronization in probability. Finally, several numerical examples are presented to show the effectiveness of the main results. PMID:26315380

Interpolation and Extrapolation of Creep Rupture Data by the Minimum Commitment Method. Part 3: Analysis of Multiheats

NASA Technical Reports Server (NTRS)

Manson, S. S.; Ensign, C. R.

1978-01-01

The Minimum Commitment Method was applied to two sets of data for which multiple heat information was available. For one alloy, a 304 stainless steel studied in Japan, data on nine well characterized heats were used, while for a proprietary low alloy carbon steel studied in the United Kingdom data were available on seven heats - in many cases to very long rupture times. For this preliminary study no instability factors were used. It was discovered that heat-to-heat variations would be accounted for by introducing heat identifiers in the form A + B log sigma where sigma is the stress and the constants A and B depend only on the heat. With these identifiers all the data could be collapsed onto a single master curve, even though there was considerable scatter among heats. Using these identifiers together with the average behavior of all heats made possible the determination of an accurate constitutive equation for each individual heat. Two basic approaches are discussed for applying the results of the analysis.

Self-Directed Student Research through Analysis of Microarray Datasets: A Computer-Based Functional Genomics Practical Class for Masters-Level Students

ERIC Educational Resources Information Center

Grenville-Briggs, Laura J.; Stansfield, Ian

2011-01-01

This report describes a linked series of Masters-level computer practical workshops. They comprise an advanced functional genomics investigation, based upon analysis of a microarray dataset probing yeast DNA damage responses. The workshops require the students to analyse highly complex transcriptomics datasets, and were designed to stimulate…

Content Analysis of Master Theses and Dissertations Based on Action Research

ERIC Educational Resources Information Center

Durak, Gürhan; Yünkül, Eyup; Cankaya, Serkan; Akpinar, Sükran; Erten, Emine; Inam, Nazmiye; Taylan, Ufuk; Tastekin, Eray

2016-01-01

Action Research (AR) is becoming popular in the field of education, and according to literature, it could be stated that AR studies have positive influence on practice in education. The present study aims at conducting content analysis of action research (AR) master theses and doctoral dissertations submitted at the level of Turkish higher…

Risk Assessment Planning for Airborne Systems: An Information Assurance Failure Mode, Effects and Criticality Analysis Methodology

DTIC Science & Technology

2012-06-01

Visa Investigate Data Breach March 30, 2012 Visa and MasterCard are investigating whether a data security breach at one of the main companies that...30). MasterCard and Visa Investigate Data Breach . New York Times . Stamatis, D. (2003). Failure Mode Effect Analysis: FMEA from Theory to Execution

The master degree: A critical transition in STEM doctoral education

NASA Astrophysics Data System (ADS)

Lange, Sheila Edwards

The need to broaden participation in the nation's science, technology, engineering, and mathematics (STEM) undergraduate and graduate programs is currently a matter of national urgency. The small number of women and underrepresented minorities (URM) earning doctoral degrees in STEM is particularly troubling given significant increases in the number of students earning master's degrees since 1990. In the decade between 1990 and 2000, the total number of master's recipients increased by 42%. During this same time period, the number of women earning master's degrees increased by 56%, African Americans increased by 132%, American Indians by 101%, Hispanics by 146%, and Asian Americans by 117% (Syverson, 2003). Growth in underrepresented group education at the master's level raises questions about the relationship between master's and doctoral education. Secondary data analysis of the Survey of Earned Doctorates (SED) was used to examine institutional pathways to the doctorate in STEM disciplines and transitions from master's to doctoral programs by race and gender. While the study revealed no significant gender differences in pathways, compared to White and Asian American students, URM students take significantly different pathways to the doctorate. URM students are significantly more likely to earn the bachelor's, master's, and doctoral degrees at three different institutions. Their path is significantly more likely to include earning a master's degree en route to the doctorate. Further, URM students are more likely to experience transition between the master's and doctoral degrees, and the transitions are not limited to those who earn master's degrees at master's-only institutions. These findings suggest that earning a master's degree is more often a stepping stone to the doctorate for URM students. Master's degree programs, therefore, have the potential to be a valuable resource for policymakers and graduate programs seeking to increase the diversity of URM students earning doctorates in STEM.

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.

Nonlinear finite element modeling of vibration control of plane rod-type structural members with integrated piezoelectric patches

NASA Astrophysics Data System (ADS)

Chróścielewski, Jacek; Schmidt, Rüdiger; Eremeyev, Victor A.

2018-05-01

This paper addresses modeling and finite element analysis of the transient large-amplitude vibration response of thin rod-type structures (e.g., plane curved beams, arches, ring shells) and its control by integrated piezoelectric layers. A geometrically nonlinear finite beam element for the analysis of piezolaminated structures is developed that is based on the Bernoulli hypothesis and the assumptions of small strains and finite rotations of the normal. The finite element model can be applied to static, stability, and transient analysis of smart structures consisting of a master structure and integrated piezoelectric actuator layers or patches attached to the upper and lower surfaces. Two problems are studied extensively: (i) FE analyses of a clamped semicircular ring shell that has been used as a benchmark problem for linear vibration control in several recent papers are critically reviewed and extended to account for the effects of structural nonlinearity and (ii) a smart circular arch subjected to a hydrostatic pressure load is investigated statically and dynamically in order to study the shift of bifurcation and limit points, eigenfrequencies, and eigenvectors, as well as vibration control for loading conditions which may lead to dynamic loss of stability.

Data Quality- and Master Data Management - A Hospital Case.

PubMed

Arthofer, Klaus; Girardi, Dominic

2017-01-01

Poor data quality prevents the analysis of data for decisions which are critical for business. It also has a negative impact on business processes. Nevertheless the maturity level of data quality- and master data management is still insufficient in many organizations nowadays. This article discusses the corresponding maturity of companies and a management cycle integrating data quality- and master data management in a case dealing with benchmarking in hospitals. In conclusion if data quality and master data are not properly managed, structured data should not be acquired in the first place due to the added expense and complexity.

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.

Master Curve and Conventional Fracture Toughness of Modified 9Cr-1Mo Steel

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

Ji-Hyun, Yoon; Sung-Ho, Kim; Bong-Sang, Lee

2006-07-01

Modified 9Cr-1Mo steel is a primary candidate material for reactor pressure vessel of Very High Temperature Gas-Cooled Reactor (VHTR) in Korean Nuclear Hydrogen Development and Demonstration (NHDD) program. In this study, T0 reference temperature, J-R fracture resistance and Charpy impact properties were evaluated for commercial Grade 91 steel as preliminary tests for the selection of the RPV material for VHTR. The fracture toughness of the modified 9Cr-1Mo steel was compared with those of SA508-Gr.3. The objective of this study was to obtain pre-irradiation fracture toughness properties of modified 9Cr-1Mo steel as reference data for the radiation effects investigation. The resultsmore » are as follows. Charpy impact properties of the modified 9Cr-1Mo steel were similar to those of SA508-Gr.3. T0 reference temperatures were measured as -67.7 deg C and -72.4 deg C from the tests with standard PCVN (pre-cracked Charpy V-notch) and half sized PCVN specimens respectively, which were similar to results for SA508-Gr.3. The K{sub Jc} values of modified 9Cr-1Mo with test temperatures are successfully expressed with the Master Curve. The J-R fracture resistance of modified 9Cr-1Mo steel at room temperature was almost the same as that of SA508-Gr.3. On the other hand it was a little bit higher at an elevated temperature. (authors)« less

Fracture toughness and the master curve for modified 9Cr-1Mo steel

NASA Astrophysics Data System (ADS)

Yoon, Ji-Hyun; Yoon, Eui-Pak

2006-12-01

Modified 9Cr-1Mo steel is a primary candidate material for the reactor pressure vessel of a Very High Temperature Gas-Cooled Reactor (VHTR) in the Korean Nuclear Hydrogen Development and Demonstration (NHDD) program. In this study, the T0 reference temperature, J-R fracture resistance and Charpy impact properties were evaluated for commercial Grade 91 steel as part of the preliminary testing for a selection of the RPV material for the VHTR. The fracture toughness of the modified 9Cr-1Mo steel was compared with that of SA508-Gr.3. The objective of this study was to obtain the pre-irradiation fracture toughness properties of the modified 9Cr-1Mo steel as reference data for an investigation of radiation effects. Charpy impact properties of the modified 9Cr-1Mo steel were similar to those of SA508-Gr.3. T0 reference temperatures were measured as -67.7 and -72.4°C from the tests with standard PCVN (pre-cracked Charpy V-notch) and half-sized PCVN specimens respectively, which were similar to the results for SA508-Gr.3. The KJc values of the modified 9Cr-1Mo steel with the test temperatures are successfully expressed by the Master Curve. The J-R fracture resistance of the modified 9Cr-1Mo steel at room temperature was nearly identical to that of SA508-Gr.3; in contrast, it was slightly higher at an elevated temperature.

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.

Efficacy of D-RaCe and ProTaper Universal Retreatment NiTi instruments and hand files in removing gutta-percha from curved root canals - a micro-computed tomography study.

PubMed

Rödig, T; Hausdörfer, T; Konietschke, F; Dullin, C; Hahn, W; Hülsmann, M

2012-06-01

To compare the efficacy of two rotary NiTi retreatment systems and Hedström files in removing filling material from curved root canals. Curved root canals of 57 extracted teeth were prepared using FlexMaster instruments and filled with gutta-percha and AH Plus. After determination of root canal curvatures and radii in two directions, the teeth were assigned to three identical groups (n = 19). The root fillings were removed with D-RaCe instruments, ProTaper Universal Retreatment instruments or Hedström files. Pre- and postoperative micro-CT imaging was used to assess the percentage of residual filling material as well as the amount of dentine removal. Working time and procedural errors were recorded. Data were analysed using analysis of covariance and analysis of variance procedures. D-RaCe instruments were significantly more effective than ProTaper Universal Retreatment instruments and Hedström files (P < 0.05). Hedström files removed significantly less dentine than the rotary NiTi systems (P < 0.0001). D-RaCe instruments were significantly faster compared to both other groups (P < 0.05). No procedural errors such as instrument fracture, blockage, ledging or perforation were detected in the Hedström group. In the ProTaper group, four instrument fractures and one lateral perforation were observed. Five instrument fractures were recorded for D-RaCe. D-RaCe instruments were associated with significantly less residual filling material than ProTaper Universal Retreatment instruments and hand files. Hedström files removed significantly less dentine than both rotary NiTi systems. Retreatment with rotary NiTi systems resulted in a high incidence of procedural errors. © 2012 International Endodontic Journal.

Selections from 2017: Image Processing with AstroImageJ

NASA Astrophysics Data System (ADS)

Kohler, Susanna

2017-12-01

Editors note:In these last two weeks of 2017, well be looking at a few selections that we havent yet discussed on AAS Nova from among the most-downloaded paperspublished in AAS journals this year. The usual posting schedule will resume in January.AstroImageJ: Image Processing and Photometric Extraction for Ultra-Precise Astronomical Light CurvesPublished January2017The AIJ image display. A wide range of astronomy specific image display options and image analysis tools are available from the menus, quick access icons, and interactive histogram. [Collins et al. 2017]Main takeaway:AstroImageJ is a new integrated software package presented in a publication led byKaren Collins(Vanderbilt University,Fisk University, andUniversity of Louisville). Itenables new users even at the level of undergraduate student, high school student, or amateur astronomer to quickly start processing, modeling, and plotting astronomical image data.Why its interesting:Science doesnt just happen the momenta telescope captures a picture of a distantobject. Instead, astronomical images must firstbe carefully processed to clean up thedata, and this data must then be systematically analyzed to learn about the objects within it. AstroImageJ as a GUI-driven, easily installed, public-domain tool is a uniquelyaccessible tool for thisprocessing and analysis, allowing even non-specialist users to explore and visualizeastronomical data.Some features ofAstroImageJ:(as reported by Astrobites)Image calibration:generate master flat, dark, and bias framesImage arithmetic:combineimages viasubtraction, addition, division, multiplication, etc.Stack editing:easily perform operations on a series of imagesImage stabilization and image alignment featuresPrecise coordinate converters:calculate Heliocentric and Barycentric Julian DatesWCS coordinates:determine precisely where atelescope was pointed for an image by PlateSolving using Astronomy.netMacro and plugin support:write your own macrosMulti-aperture photometry with interactive light curve fitting:plot light curves of a star in real timeCitationKaren A. Collins et al 2017 AJ 153 77. doi:10.3847/1538-3881/153/2/77

[Preventing maternal and child malnutrition: the nutrition component of the Mesoamerican Health Initiative 2015].

PubMed

Rivera, Juan A; Martorell, Reynaldo; González, Wendy; Lutter, Chessa; Cossío, Teresa González de; Flores-Ayala, Rafael; Uauy, Ricardo; Delgado, Hernán

2011-01-01

To describe the regional master plan of nutrition to address maternal and child malnutrition in a 5- year period developed by the Nutrition Technical Group. The Nutrition Technical Group developed a situation analysis describing the main nutrition problems, policies and programs in Mesoamerica. The situation analysis and a literature review about effective interventions to address malnutrition were conducted to develop a nutrition master plan. The Nutrition Technical Group held various meetings to develop, discuss and validate the master plan. Theory of change identified problems and barriers, the actions to be developed, the changes and impacts expected. A package of interventions is proposed to reduce undernutrition and micronutrient deficiencies useful under different epidemiological contexts. The nutrition master plan provides a guideline of best practices that can be used for evidence-informed decision making and the development of national policies and programs to reduce malnutrition.

A Content Analysis Related to Theses in Environmental Education: The Case of Turkey (2011-2015)

ERIC Educational Resources Information Center

Yavuz, Soner

2016-01-01

Environmental chemistry has been a research subject for master thesis and doctoral dissertations since the end of 1980s. Because of the wide usage of in literature, it is essential to draw a framework about the subject. For this reason, content analysis is conducted to analyze master thesis and doctoral dissertations about Environmental Education,…

AAMFT Master Series Tapes: An Analysis of the Inclusion of Feminist Principles into Family Therapy Practice.

ERIC Educational Resources Information Center

Haddock, Shelley A.; MacPhee, David; Zimmerman, Toni Schindler

2001-01-01

Content analysis of 23 American Association for Marriage and Family Therapy Master Series tapes was used to determine how well feminist behaviors have been incorporated into ideal family therapy practice. Feminist behaviors were infrequent, being evident in fewer than 3% of time blocks in event sampling and 10 of 39 feminist behaviors of the…

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.

Comparison of commercial RNA extraction kits and qPCR master mixes for studying gene expression in small biopsy tissue samples from the equine gastric epithelium.

PubMed

Tesena, Parichart; Korchunjit, Wasamon; Taylor, Jane; Wongtawan, Tuempong

2017-01-01

Gastric tissue biopsy and gene expression analysis are important tools for disease diagnosis and study of the physiology of the equine stomach. However, RNA extraction from gastric biopsy samples is a complex procedure because the samples contain low quantities of RNA and are contaminated with mucous protein and bacterial flora. The objectives of these studies were to compare the performance of RNA extraction methods and to investigate the sensitivity of commercial qPCR master mixes for gene expression analysis of gastric biopsy samples. Three commercial RNA extraction methods (TRIzol ™ , GENEzol ™ and MiniPrep ™ ) and four qPCR master mixes with SYBR ® green (qPCRBIO, KAPA, QuantiNova, and PerfeCTa) were compared. RNA qualification and quantitation were compared. Real-time PCR was used to compare qPCR master mixes. The results revealed that TRIzol and GENEzol obtained significantly higher yield of RNA (P<0.01) but that TRIzol had the highest contamination of protein and DNA (P<0.05). Conversely, MiniPrep resulting in a significantly higher purification of RNA (P<0.05) but provided the lowest yield of RNA (P<0.01). For PCR master mixes, KAPA was significantly (P<0.05) more sensitive than other qPCR kits for all amounts of DNA template, particularly at the lowest amount of cDNA. In conclusion, GENEzol is the best method to obtain a high RNA yield and purification and it is more cost-effective than the others as well. Regarding the qPCR master mixes, KAPA SYBR qPCR Master Mix (2x) Universal is superior to the other tested master mixes for studying gene expression in equine gastric biopsies.

Corridor Planning And Feasibility Analysis Corridor, Master Plan

DOT National Transportation Integrated Search

1996-04-01

THE I-70 RURAL IVHS CORRIDOR MASTER PLAN IS THE GUIDANCE DOCUMENT FOR DEPLOYMENT OF THE INTELLIGENT TRANSPORTATION SYSTEM (ITS) FOR THE INTERSTATE-70 CORRIDOR FROM DENVER TO GLENWOOD SPRINGS, COLORADO. AS A WORKING DOCUMENT, THE PLAN RECOMMENDS STRAT...

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.

Analysis, Design, and Prototyping Of Accounting Software for Navy Signal Intelligence Collection Systems Return On Investment Reporting

DTIC Science & Technology

2010-09-01

The MasterNet project continued to expand in software and hardware complexity until its failure ( Szilagyi , n.d.). Despite all of the issues...were used for MasterNet ( Szilagyi , n.d.). Although executive management committed significant financial resources to MasterNet, Bank of America...implementation failure as well as project- management failure as a whole ( Szilagyi , n.d.). The lesson learned from this vignette is the importance of setting

Analysis of a Professional Officer Master’s Degree Program.

DTIC Science & Technology

1986-04-01

another source to convince the officer that he must have a masters For career success . The most powerful and understood form of communication to an...officer of the importance of any factor For career success is how it affects promotions. To determine if a master’s degree is important to career success , one...PME. Most Air Force officers know PME is vitally impor- tant to fulfilling professional education requirements and career success . Therefore, when

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

Alzheimer's disease master regulators analysis: search for potential molecular targets and drug repositioning candidates.

PubMed

Vargas, D M; De Bastiani, M A; Zimmer, E R; Klamt, F

2018-06-23

Alzheimer's disease (AD) is a multifactorial and complex neuropathology that involves impairment of many intricate molecular mechanisms. Despite recent advances, AD pathophysiological characterization remains incomplete, which hampers the development of effective treatments. In fact, currently, there are no effective pharmacological treatments for AD. Integrative strategies such as transcription regulatory network and master regulator analyses exemplify promising new approaches to study complex diseases and may help in the identification of potential pharmacological targets. In this study, we used transcription regulatory network and master regulator analyses on transcriptomic data of human hippocampus to identify transcription factors (TFs) that can potentially act as master regulators in AD. All expression profiles were obtained from the Gene Expression Omnibus database using the GEOquery package. A normal hippocampus transcription factor-centered regulatory network was reconstructed using the ARACNe algorithm. Master regulator analysis and two-tail gene set enrichment analysis were employed to evaluate the inferred regulatory units in AD case-control studies. Finally, we used a connectivity map adaptation to prospect new potential therapeutic interventions by drug repurposing. We identified TFs with already reported involvement in AD, such as ATF2 and PARK2, as well as possible new targets for future investigations, such as CNOT7, CSRNP2, SLC30A9, and TSC22D1. Furthermore, Connectivity Map Analysis adaptation suggested the repositioning of six FDA-approved drugs that can potentially modulate master regulator candidate regulatory units (Cefuroxime, Cyproterone, Dydrogesterone, Metrizamide, Trimethadione, and Vorinostat). Using a transcription factor-centered regulatory network reconstruction we were able to identify several potential molecular targets and six drug candidates for repositioning in AD. Our study provides further support for the use of bioinformatics tools as exploratory strategies in neurodegenerative diseases research, and also provides new perspectives on molecular targets and drug therapies for future investigation and validation in AD.

Investigating Value Creation in a Community of Practice with Social Network Analysis in a Hybrid Online Graduate Education Program

ERIC Educational Resources Information Center

Cowan, John E.; Menchaca, Michael P.

2014-01-01

This study reports an analysis of 10?years in the life of the Internet-based Master in Educational Technology program (iMET) at Sacramento State University. iMET is a hybrid educational technology master's program delivered 20% face to face and 80% online. The program has achieved a high degree of success, with a course completion rate of 93% and…

Data on master regulators and transcription factor binding sites found by upstream analysis of multi-omics data on methotrexate resistance of colon cancer.

PubMed

Kel, AlexanderE

2017-02-01

Computational analysis of master regulators through the search for transcription factor binding sites followed by analysis of signal transduction networks of a cell is a new approach of causal analysis of multi-omics data. This paper contains results on analysis of multi-omics data that include transcriptomics, proteomics and epigenomics data of methotrexate (MTX) resistant colon cancer cell line. The data were used for analysis of mechanisms of resistance and for prediction of potential drug targets and promising compounds for reverting the MTX resistance of these cancer cells. We present all results of the analysis including the lists of identified transcription factors and their binding sites in genome and the list of predicted master regulators - potential drug targets. This data was generated in the study recently published in the article "Multi-omics "Upstream Analysis" of regulatory genomic regions helps identifying targets against methotrexate resistance of colon cancer" (Kel et al., 2016) [4]. These data are of interest for researchers from the field of multi-omics data analysis and for biologists who are interested in identification of novel drug targets against NTX resistance.

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.

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.

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.

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.

Latin-square three-dimensional gage master

DOEpatents

Jones, L.

1981-05-12

A gage master for coordinate measuring machines has an nxn array of objects distributed in the Z coordinate utilizing the concept of a Latin square experimental design. Using analysis of variance techniques, the invention may be used to identify sources of error in machine geometry and quantify machine accuracy.

Latin square three dimensional gage master

DOEpatents

Jones, Lynn L.

1982-01-01

A gage master for coordinate measuring machines has an nxn array of objects distributed in the Z coordinate utilizing the concept of a Latin square experimental design. Using analysis of variance techniques, the invention may be used to identify sources of error in machine geometry and quantify machine accuracy.

Transcriptional master regulator analysis in breast cancer genetic networks.

PubMed

Tovar, Hugo; García-Herrera, Rodrigo; Espinal-Enríquez, Jesús; Hernández-Lemus, Enrique

2015-12-01

Gene regulatory networks account for the delicate mechanisms that control gene expression. Under certain circumstances, gene regulatory programs may give rise to amplification cascades. Such transcriptional cascades are events in which activation of key-responsive transcription factors called master regulators trigger a series of gene expression events. The action of transcriptional master regulators is then important for the establishment of certain programs like cell development and differentiation. However, such cascades have also been related with the onset and maintenance of cancer phenotypes. Here we present a systematic implementation of a series of algorithms aimed at the inference of a gene regulatory network and analysis of transcriptional master regulators in the context of primary breast cancer cells. Such studies were performed in a highly curated database of 880 microarray gene expression experiments on biopsy-captured tissue corresponding to primary breast cancer and healthy controls. Biological function and biochemical pathway enrichment analyses were also performed to study the role that the processes controlled - at the transcriptional level - by such master regulators may have in relation to primary breast cancer. We found that transcription factors such as AGTR2, ZNF132, TFDP3 and others are master regulators in this gene regulatory network. Sets of genes controlled by these regulators are involved in processes that are well-known hallmarks of cancer. This kind of analyses may help to understand the most upstream events in the development of phenotypes, in particular, those regarding cancer biology. Copyright © 2015 Elsevier Ltd. All rights reserved.

Online Education in Public Affairs

ERIC Educational Resources Information Center

Ginn, Martha H.; Hammond, Augustine

2012-01-01

This exploratory study provides an overview of the current landscape of online education in the fields of Master of Public Administration and Master of Public Policy (MPA/MPP) utilizing a dataset compiled from content analysis of MPA/MPP programs' websites and survey of 96 National Association of Schools of Public Affairs and Administration…

The International Space Station Comparative Maintenance Analysis(CMAM)

DTIC Science & Technology

2004-09-01

External Component • Entire ORU Database 2. Database Connectivity The CMAM ORU database consists of three tables: an ORU master parts list , an ISS...Flight table, and an ISS Subsystem table. The ORU master parts list and the ISS Flight table can be updated or modified from the CMAM user interface

78 FR 61373 - Animal Center Master Plan Record of Decision

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-03

... propose any land use changes outside NIHAC. Therefore, the NIHAC campus is anticipated to remain... analysis, Environmental Justice will not be discussed. Visual Quality The Master Plan's land use plan provides a framework to help organize future development at NIHAC so that similar land use types are...

A Consideration of the Challenges Involved in Supervising International Masters Students

ERIC Educational Resources Information Center

Brown, Lorraine

2007-01-01

This paper explores the challenges facing supervisors of international postgraduate students at the dissertation stage of the masters programme. The central problems of time pressure, language difficulties, a lack of critical analysis and a prevalence of personal problems among international students are discussed. This paper makes recommendations…

Multiple-methods investigation of recharge at a humid-region fractured rock site, Pennsylvania, USA

USGS Publications Warehouse

Heppner, C.S.; Nimmo, J.R.; Folmar, G.J.; Gburek, W.J.; Risser, D.W.

2007-01-01

Lysimeter-percolate and well-hydrograph analyses were combined to evaluate recharge for the Masser Recharge Site (central Pennsylvania, USA). In humid regions, aquifer recharge through an unconfined low-porosity fractured-rock aquifer can cause large magnitude water-table fluctuations over short time scales. The unsaturated hydraulic characteristics of the subsurface porous media control the magnitude and timing of these fluctuations. Data from multiple sets of lysimeters at the site show a highly seasonal pattern of percolate and exhibit variability due to both installation factors and hydraulic property heterogeneity. Individual event analysis of well hydrograph data reveals the primary influences on water-table response, namely rainfall depth, rainfall intensity, and initial water-table depth. Spatial and seasonal variability in well response is also evident. A new approach for calculating recharge from continuous water-table elevation records using a master recession curve (MRC) is demonstrated. The recharge estimated by the MRC approach when assuming a constant specific yield is seasonal to a lesser degree than the recharge estimate resulting from the lysimeter analysis. Partial reconciliation of the two recharge estimates is achieved by considering a conceptual model of flow processes in the highly-heterogeneous underlying fractured porous medium. ?? Springer-Verlag 2007.

NT-proBNP Predicts All-Cause Mortality in a Population of Insurance Applicants, Follow-up Analysis and Further Observations.

PubMed

Fulks, Michael; Kaufman, Valerie; Clark, Michael; Stout, Robert L

2017-01-01

- Further refine the independent value of NT-proBNP, accounting for the impact of other test results, in predicting all-cause mortality for individual life insurance applicants with and without heart disease. - Using the Social Security Death Master File and multivariate analysis, relative mortality was determined for 245,322 life insurance applicants ages 50 to 89 tested for NT-proBNP (almost all based on age and policy amount) along with other laboratory tests and measurement of blood pressure and BMI. - NT-proBNP values ≤75 pg/mL included the majority of applicants denying heart disease and had the lowest risk, while values >500 pg/mL for females and >300 pg/mL for males had very high relative risk. Those admitting to heart disease had a higher mortality risk for each band of NT-proBNP relative to those denying heart disease but had a similar and equally predictive risk curve. - NT-proBNP is a strong independent predictor of all-cause mortality in the absence or presence of known heart disease but the range of values associated with increased risk varies by sex.

Automation of processing and photometric data analysis for transiting exoplanets observed with ESO NIR instrument HAWK-I

NASA Astrophysics Data System (ADS)

Blažek, M.; Kabáth, P.; Klocová, T.; Skarka, M.

2018-04-01

Nowadays, when amount of data still increases, it is necessary to automatise their processing. State-of-the-art instruments are capable to produce even tens of thousands of images during a single night. One of them is HAWK-I that is a part of Very Large Telescope of European Southern Observatory. This instrument works in near-infrared band. In my Master thesis, I dealt with developing a pipeline to process data obtained by the instrument. It is written in Python programming language using commands of IRAF astronomical software and it is developed directly for "Fast Photometry Mode" of HAWK-I. In this mode, a large number of data has been obtained during secondary eclipses of exoplanets by their host star. The pipeline was tested by a data set from sorting of the images to making a light curve. The data of WASP-18 system contained almost 40 000 images observed by using a filter centered at 2.09 μm wavelength and there is a plan to process other data sets. A goal of processing of WASP-18 and the other data sets is consecutive analysis of exoplanetary atmospheres of the observed systems.

Performance Trends in Master Butterfly Swimmers Competing in the FINA World Championships.

PubMed

Knechtle, Beat; Nikolaidis, Pantelis T; Rosemann, Thomas; Rüst, Christoph A

2017-06-01

Performance trends in elite butterfly swimmers are well known, but less information is available regarding master butterfly swimmers. We investigated trends in participation, performance and sex differences in 9,606 female and 13,250 male butterfly race times classified into five-year master groups, from 25-29 to 90-94 years, competing in the FINA World Masters Championships between 1986 and 2014. Trends in participation were analyzed using linear regression analysis. Trends in performance changes were investigated using mixed-effects regression analyses with sex, distance and a calendar year as fixed variables. We also considered interaction effects between sex and distance. Participation increased in master swimmers older than ~30-40 years. The men-to-women ratio remained unchanged across calendar years and master groups, but was lower in 200 m compared to 50 m and 100 m. Men were faster than women from 25-29 to 85-89 years (p < 0.05), although not for 90-94 years. Sex and distance showed a significant interaction in all master groups from 25-29 to 90-94 years for 200m (p < 0.05). For 50 m and 100 m, a significant sex × distance interaction was observed from 25-29 to 75-79 years (p < 0.05), but not in the older groups. In 50 m, women reduced the sex difference in master groups 30-34 to 60-64 years (p < 0.05). In 100 m, women decreased the gap to men in master groups 35-39 to 55-59 years (p < 0.05). In 200 m, the sex difference was reduced in master groups 30-34 to 40-44 years (p < 0.05). In summary, women and men improved performance at all distances, women were not slower compared to men in the master group 90-94 years; moreover, women reduced the gap to men between ~30 and ~60 years, although not in younger or older master groups.

Performance Trends in Master Butterfly Swimmers Competing in the FINA World Championships

PubMed Central

Knechtle, Beat; Nikolaidis, Pantelis T; Rosemann, Thomas; Rüst, Christoph A

2017-01-01

Abstract Performance trends in elite butterfly swimmers are well known, but less information is available regarding master butterfly swimmers. We investigated trends in participation, performance and sex differences in 9,606 female and 13,250 male butterfly race times classified into five-year master groups, from 25-29 to 90-94 years, competing in the FINA World Masters Championships between 1986 and 2014. Trends in participation were analyzed using linear regression analysis. Trends in performance changes were investigated using mixed-effects regression analyses with sex, distance and a calendar year as fixed variables. We also considered interaction effects between sex and distance. Participation increased in master swimmers older than ~30-40 years. The men-to-women ratio remained unchanged across calendar years and master groups, but was lower in 200 m compared to 50 m and 100 m. Men were faster than women from 25-29 to 85-89 years (p < 0.05), although not for 90-94 years. Sex and distance showed a significant interaction in all master groups from 25-29 to 90-94 years for 200m (p < 0.05). For 50 m and 100 m, a significant sex × distance interaction was observed from 25-29 to 75-79 years (p < 0.05), but not in the older groups. In 50 m, women reduced the sex difference in master groups 30-34 to 60-64 years (p < 0.05). In 100 m, women decreased the gap to men in master groups 35-39 to 55-59 years (p < 0.05). In 200 m, the sex difference was reduced in master groups 30-34 to 40-44 years (p < 0.05). In summary, women and men improved performance at all distances, women were not slower compared to men in the master group 90-94 years; moreover, women reduced the gap to men between ~30 and ~60 years, although not in younger or older master groups. PMID:28713472

Modeling and Dynamic Analysis of Paralleled dc/dc Converters With Master-Slave Current Sharing Control

NASA Technical Reports Server (NTRS)

Rajagopalan, J.; Xing, K.; Guo, Y.; Lee, F. C.; Manners, Bruce

1996-01-01

A simple, application-oriented, transfer function model of paralleled converters employing Master-Slave Current-sharing (MSC) control is developed. Dynamically, the Master converter retains its original design characteristics; all the Slave converters are forced to depart significantly from their original design characteristics into current-controlled current sources. Five distinct loop gains to assess system stability and performance are identified and their physical significance is described. A design methodology for the current share compensator is presented. The effect of this current sharing scheme on 'system output impedance' is analyzed.

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.

An all-joint-control master device for single-port laparoscopic surgery robots.

PubMed

Shim, Seongbo; Kang, Taehun; Ji, Daekeun; Choi, Hyunseok; Joung, Sanghyun; Hong, Jaesung

2016-08-01

Robots for single-port laparoscopic surgery (SPLS) typically have all of their joints located inside abdomen during surgery, whereas with the da Vinci system, only the tip part of the robot arm is inserted and manipulated. A typical master device that controls only the tip with six degrees of freedom (DOFs) is not suitable for use with SPLS robots because of safety concerns. We designed an ergonomic six-DOF master device that can control all of the joints of an SPLS robot. We matched each joint of the master, the slave, and the human arm to decouple all-joint motions of the slave robot. Counterbalance masses were used to reduce operator fatigue. Mapping factors were determined based on kinematic analysis and were used to achieve all-joint control with minimal error at the tip of the slave robot. The proposed master device has two noteworthy features: efficient joint matching to the human arm to decouple each joint motion of the slave robot and accurate mapping factors, which can minimize the trajectory error of the tips between the master and the slave. We confirmed that the operator can manipulate the slave robot intuitively with the master device and that both tips have similar trajectories with minimal error.

An Icelandic Version of McMasters Family Assessment Device (FAD)

ERIC Educational Resources Information Center

Juliusdottir, Gudlaug M.; Olafsdottir, Hrefna

2015-01-01

Purpose: An analysis of the psychometric properties of an Icelandic version of McMasters Family Assessment Device (FAD) was conducted in this study. Method: Two groups, clinical and nonclinical, comprising of 529 parents answered the FAD. The study examined the internal reliability and discriminant validity of the instrument in addition to…

Short-Term Missions at the Master's College: An Experiential Education

ERIC Educational Resources Information Center

La George, Lisa

2009-01-01

Foreign Missions Preparation (FMP) has been in operation at The Master's College (TMC) since 1989, employing experiential education to train and facilitate cross-cultural summer Short-Term Mission (STM) trips for over a thousand undergraduate students. The question driving the case study was: "What influence does an analysis of the experiences of…

Quality of Master's Education: A Concern for Counseling Psychology?

ERIC Educational Resources Information Center

Jackson, Margo A.; Scheel, Michael J.

2013-01-01

The authors offer an analysis of current challenges and opportunities regarding the long-standing issue about the quality and status of master's education relevant to training and practice in counseling psychology. Highlighted are historical context, controversies regarding licensure and accreditation (e.g., the 2009 Council for Accreditation…

The Comprehensive Soldier Fitness Program Evaluation. Report 3: Longitudinal Analysis of the Impact of Master Resilience Training on Self-Reported Resilience and Psychological Health Data

DTIC Science & Technology

2011-12-01

G. M. (2001). Psychological testing and psychological assessment. A review of evidence and issues. American Psychologist, 56, 128-165. Mikulincer...Orientation Test . Journal of Personality and Social Psychology , 67, 1063- 1078. Sharkansky, E. J., King, D. W., King, L. A., Wolfe, J., Erickson, D. J...3: Longitudinal Analysis of the Impact of Master Resilience Training on Self-Reported Resilience and Psychological Health Data, December 2011

Transient performance analysis of the master cylinder hydraulic system of a 6.3 MN fineblanking press

NASA Astrophysics Data System (ADS)

Yi, Guodong; Li, Jin

2018-03-01

The master cylinder hydraulic system is the core component of the fineblanking press that seriously affects the machine performance. A key issue in the design of the master cylinder hydraulic system is dealing with the heavy shock loads in the fineblanking process. In this paper, an equivalent model of the master cylinder hydraulic system is established based on typical process parameters for practical fineblanking; then, the response characteristics of the master cylinder slider to the step changes in the load and control current are analyzed, and lastly, control strategies for the proportional valve are studied based on the impact of the control parameters on the kinetic stability of the slider. The results show that the kinetic stability of the slider is significantly affected by the step change of the control current, while it is slightly affected by the step change of the system load, which can be improved by adjusting the flow rate and opening time of the proportional valve.

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.

Modeling and Dynamic Analysis of Paralleled of dc/dc Converters with Master-Slave Current Sharing Control

NASA Technical Reports Server (NTRS)

Rajagopalan, J.; Xing, K.; Guo, Y.; Lee, F. C.; Manners, Bruce

1996-01-01

A simple, application-oriented, transfer function model of paralleled converters employing Master-Slave Current-sharing (MSC) control is developed. Dynamically, the Master converter retains its original design characteristics; all the Slave converters are forced to depart significantly from their original design characteristics into current-controlled current sources. Five distinct loop gains to assess system stability and performance are identified and their physical significance is described. A design methodology for the current share compensator is presented. The effect of this current sharing scheme on 'system output impedance' is analyzed.

SWOT analysis to evaluate the programme of a joint online/onsite master's degree in environmental education through the students' perceptions.

PubMed

Romero-Gutierrez, Miguel; Jimenez-Liso, M Rut; Martinez-Chico, Maria

2016-02-01

This study shows the use of SWOT to analyse students' perceptions of an environmental education joint master's programme in order to determine if it runs as originally planned. The open answers given by students highlight the inter-university nature of the master's, the technological innovation used as major points, and the weaknesses in the management coordination or the duplicate contents as minor points. The external analysis is closely linked with the students' future jobs, their labour opportunities available to them after graduation. The innovative treatment of the data is exportable to the evaluation of programmes of other degrees because it allows the description linked to its characteristics and its design through the students' point of view. Copyright © 2015 Elsevier Ltd. All rights reserved.

Stroma-associated master regulators of molecular subtypes predict patient prognosis in ovarian cancer.

PubMed

Zhang, Shengzhe; Jing, Ying; Zhang, Meiying; Zhang, Zhenfeng; Ma, Pengfei; Peng, Huixin; Shi, Kaixuan; Gao, Wei-Qiang; Zhuang, Guanglei

2015-11-04

High-grade serous ovarian carcinoma (HGS-OvCa) has the lowest survival rate among all gynecologic cancers and is hallmarked by a high degree of heterogeneity. The Cancer Genome Atlas network has described a gene expression-based molecular classification of HGS-OvCa into Differentiated, Mesenchymal, Immunoreactive and Proliferative subtypes. However, the biological underpinnings and regulatory mechanisms underlying the distinct molecular subtypes are largely unknown. Here we showed that tumor-infiltrating stromal cells significantly contributed to the assignments of Mesenchymal and Immunoreactive clusters. Using reverse engineering and an unbiased interrogation of subtype regulatory networks, we identified the transcriptional modules containing master regulators that drive gene expression of Mesenchymal and Immunoreactive HGS-OvCa. Mesenchymal master regulators were associated with poor prognosis, while Immunoreactive master regulators positively correlated with overall survival. Meta-analysis of 749 HGS-OvCa expression profiles confirmed that master regulators as a prognostic signature were able to predict patient outcome. Our data unraveled master regulatory programs of HGS-OvCa subtypes with prognostic and potentially therapeutic relevance, and suggested that the unique transcriptional and clinical characteristics of ovarian Mesenchymal and Immunoreactive subtypes could be, at least partially, ascribed to tumor microenvironment.

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.

Research in Adult and Continuing Education: Master of Adult and Continuing Education Program.

ERIC Educational Resources Information Center

Washington State Univ., Pullman. Coll. of Education.

The document presents an annotated bibliography of Master's degree theses in Adult and Continuing Education, Washington State University, 1974-76. Abstracts for the following 12 theses are presented: (1) Agrarian Reform in Chile: A Case Study; (2) An Analysis of the Activities and the Needs of the Senior Citizens in Garfield, Washington and the…

Exploring the Dimensions of Brand Reputation in Higher Education--A Case Study of a Finnish Master's Degree Programme

ERIC Educational Resources Information Center

Suomi, Kati

2014-01-01

This exploratory study examines the dimensions that are relevant to brand reputation, particularly in the context of master's degree programmes. The data analysis is based on Vidaver-Cohen's "Business school quality dimensions and reputational attributes". The qualitative data for the case study comprise a student questionnaire and…

An Exploration of the Perceived Impact of Post-Master's Experience on Doctoral Study in Counselor Education and Supervision

ERIC Educational Resources Information Center

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

2017-01-01

Using quantitative and qualitative analysis, the perceived impact of post-master's experience (PME) during counselor education and supervision (CES) doctoral study was examined across five core areas of professional identity development: counseling, supervision, teaching, research and scholarship, and leadership and advocacy. The results showed…

A Value-Added Approach to Selecting the Best Master of Business Administration (MBA) Program

ERIC Educational Resources Information Center

Fisher, Dorothy M.; Kiang, Melody; Fisher, Steven A.

2007-01-01

Although numerous studies rank master of business administration (MBA) programs, prospective students' selection of the best MBA program is a formidable task. In this study, the authors used a linear-programming-based model called data envelopment analysis (DEA) to evaluate MBA programs. The DEA model connects costs to benefits to evaluate the…

Does Educational Preparation Match Professional Practice: The Case of Higher Education Policy Analysts

ERIC Educational Resources Information Center

Arellano, Eduardo C.; Martinez, Mario C.

2009-01-01

This study compares the extent to which higher education policy analysts and master's and doctoral faculty of higher education and public affairs programs match on a set of competencies thought to be important to higher education policy analysis. Analysts matched master's faculty in three competencies while analysts and doctoral faculty matched in…

Perceived Challenges in Primary Literature in a Master's Class: Effects of Experience and Instruction

ERIC Educational Resources Information Center

Lie, Richard; Abdullah, Christopher; He, Wenliang; Tour, Ella

2016-01-01

Primary literature offers rich opportunities to teach students how to "think like a scientist," but the challenges students face when they attempt to read research articles are not well understood. Here, we present an analysis of what master's students perceive as the most challenging aspects of engaging with primary literature. We…

The Structure of the University Network: From the Soviet to Russian "Master Plan"

ERIC Educational Resources Information Center

Kuzminov, Ia. I.; Semenov, D. S.; Froumin, I. D.

2015-01-01

The authors discuss the underpinnings of structural analysis in the higher education system. The article justifies why it focuses on specific labor market segments and the nature of the university's basic product as grounds for proposing a typology and groups of institutions. A Soviet "master plan" is reconstructed on the basis of the…

An Analysis of CPA Firm Recruiters' Perceptions of Online Masters of Accounting Degrees

ERIC Educational Resources Information Center

Metrejean, Eddie; Noland, Thomas G.

2011-01-01

Online education continues to grow at a rapid pace. Assessment of the effectiveness of online programs is needed to differentiate legitimate programs from diploma mills. The authors examined the perceptions of CPA firm recruiters on whether an online Master of Accounting (MACC) matters in the hiring decision. Results show that recruiters do not…

Mastering Overdetection and Underdetection in Learner-Answer Processing: Simple Techniques for Analysis and Diagnosis

ERIC Educational Resources Information Center

Blanchard, Alexia; Kraif, Olivier; Ponton, Claude

2009-01-01

This paper presents a "didactic triangulation" strategy to cope with the problem of reliability of NLP applications for computer-assisted language learning (CALL) systems. It is based on the implementation of basic but well mastered NLP techniques and puts the emphasis on an adapted gearing between computable linguistic clues and didactic features…

The First Radiocarbon-Constrained Full-Vector Holocene Paleomagnetic Secular Variation Reconstruction for Eastern Canada

NASA Astrophysics Data System (ADS)

Barletta, F.; St-Onge, G.; Stoner, J.; Lajeunesse, P.

2009-05-01

Here we present the first high-resolution Holocene paleomagnetic secular variation (PSV) master curve and relative paleointensity stack constrained by radiocarbon dates for Eastern Canada. This reconstruction is based on seven sedimentary sequences collected from the St. Lawrence Estuary and Gulf from the head to the mouth of the Laurentian Channel. The natural remanent magnetization (NRM), the anhysteretic remanent magnetization (ARM) and the isothermal remanent magnetization (IRM) were measured on u-channel samples at the Paleomagnetism Laboratory of ISMER using a 2G Enterprises cryogenic magnetometer. Magnetic mineralogy was additionally assessed using a recently installed alternative gradient force magnetometer (AGM). The magnetic mineralogy of the Holocene postglacial sediments is mainly carried by low-coercivity ferrimagnetic minerals (most likely magnetite) in the pseudo-single domain size range. The characteristic remanent magnetization (ChRM), assessed by principal component analysis, reveals the presence of a stable and well-defined magnetization characterized by maximum angular deviation (MAD) values generally lower than 5°. Furthermore, ChRM inclinations fluctuate around the expected geocentric axial dipole (GAD) magnetic inclination for the latitude of the coring sites (from 63° to 66°). The similarity of these records on their own independent timescales implies that all of the individual sedimentary sequences record a reliable Holocene PSV record for Eastern Canada. Relative paleointensity (RPI) was estimated by normalizing the NRM by the ARM which provided the best coercivity match. Lastly, the paleomagnetic directional and RPI records were stacked on a common time scale spanning the last ~10 000 cal BP. The smoothed PSV stack reveal centennial- to millennial-scale geomagnetic features concordant with the CALS7K.2 time-varying spherical harmonic model, as well as with the US eastern stack (King and Peck, 2001). Comparisons further a field with the Fish Lake record from Oregon (Verosub et al., 1996), the Icelandic and E. Greenland continental margin records (Stoner et al., 2007) and the Fennoscandia stack (Snowball et al., 2007) suggest large scale coherence of geomagnetic features. These and other comparisons will be made. In conclusion, the full-vector Holocene PSV and RPI master curves from Eastern Canada provide a new high-resolution regional chronostratigraphic tool as well as new insights into the Holocene geomagnetic field behaviour.

Evaluation of accuracy and precision of a smartphone based automated parasite egg counting system in comparison to the McMaster and Mini-FLOTAC methods.

PubMed

Scare, J A; Slusarewicz, P; Noel, M L; Wielgus, K M; Nielsen, M K

2017-11-30

Fecal egg counts are emphasized for guiding equine helminth parasite control regimens due to the rise of anthelmintic resistance. This, however, poses further challenges, since egg counting results are prone to issues such as operator dependency, method variability, equipment requirements, and time commitment. The use of image analysis software for performing fecal egg counts is promoted in recent studies to reduce the operator dependency associated with manual counts. In an attempt to remove operator dependency associated with current methods, we developed a diagnostic system that utilizes a smartphone and employs image analysis to generate automated egg counts. The aims of this study were (1) to determine precision of the first smartphone prototype, the modified McMaster and ImageJ; (2) to determine precision, accuracy, sensitivity, and specificity of the second smartphone prototype, the modified McMaster, and Mini-FLOTAC techniques. Repeated counts on fecal samples naturally infected with equine strongyle eggs were performed using each technique to evaluate precision. Triplicate counts on 36 egg count negative samples and 36 samples spiked with strongyle eggs at 5, 50, 500, and 1000 eggs per gram were performed using a second smartphone system prototype, Mini-FLOTAC, and McMaster to determine technique accuracy. Precision across the techniques was evaluated using the coefficient of variation. In regards to the first aim of the study, the McMaster technique performed with significantly less variance than the first smartphone prototype and ImageJ (p<0.0001). The smartphone and ImageJ performed with equal variance. In regards to the second aim of the study, the second smartphone system prototype had significantly better precision than the McMaster (p<0.0001) and Mini-FLOTAC (p<0.0001) methods, and the Mini-FLOTAC was significantly more precise than the McMaster (p=0.0228). Mean accuracies for the Mini-FLOTAC, McMaster, and smartphone system were 64.51%, 21.67%, and 32.53%, respectively. The Mini-FLOTAC was significantly more accurate than the McMaster (p<0.0001) and the smartphone system (p<0.0001), while the smartphone and McMaster counts did not have statistically different accuracies. Overall, the smartphone system compared favorably to manual methods with regards to precision, and reasonably with regards to accuracy. With further refinement, this system could become useful in veterinary practice. Copyright © 2017 Elsevier B.V. All rights reserved.

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.

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.

Revisiting the Master-Signifier, or, Mandela and Repression.

PubMed

Hook, Derek; Vanheule, Stijn

2015-01-01

The concept of the master-signifier has been subject to a variety of applications in Lacanian forms of political discourse theory and ideology critique. While there is much to be commended in literature of this sort, it often neglects salient issues pertaining to the role of master signifiers in the clinical domain of (individual) psychical economy. The popularity of the concept of the master (or "empty") signifier in political discourse analysis has thus proved a double-edged sword. On the one hand it demonstrates how crucial psychical processes are performed via the operations of the signifier, extending thus the Lacanian thesis that identification is the outcome of linguistic and symbolic as opposed to merely psychological processes. On the other, the use of the master signifier concept within the political realm to track discursive formations tends to distance the term from the dynamics of the unconscious and operation of repression. Accordingly, this paper revisits the master signifier concept, and does so within the socio-political domain, yet while paying particular attention to the functioning of unconscious processes of fantasy and repression. More specifically, it investigates how Nelson Mandela operates as a master signifier in contemporary South Africa, as a vital means of knitting together diverse elements of post-apartheid society, enabling the fantasy of the post-apartheid nation, and holding at bay a whole series of repressed and negated undercurrents.

Revisiting the Master-Signifier, or, Mandela and Repression

PubMed Central

Hook, Derek; Vanheule, Stijn

2016-01-01

The concept of the master-signifier has been subject to a variety of applications in Lacanian forms of political discourse theory and ideology critique. While there is much to be commended in literature of this sort, it often neglects salient issues pertaining to the role of master signifiers in the clinical domain of (individual) psychical economy. The popularity of the concept of the master (or “empty”) signifier in political discourse analysis has thus proved a double-edged sword. On the one hand it demonstrates how crucial psychical processes are performed via the operations of the signifier, extending thus the Lacanian thesis that identification is the outcome of linguistic and symbolic as opposed to merely psychological processes. On the other, the use of the master signifier concept within the political realm to track discursive formations tends to distance the term from the dynamics of the unconscious and operation of repression. Accordingly, this paper revisits the master signifier concept, and does so within the socio-political domain, yet while paying particular attention to the functioning of unconscious processes of fantasy and repression. More specifically, it investigates how Nelson Mandela operates as a master signifier in contemporary South Africa, as a vital means of knitting together diverse elements of post-apartheid society, enabling the fantasy of the post-apartheid nation, and holding at bay a whole series of repressed and negated undercurrents. PMID:26834664

Systems approach identifies an organic nitrogen-responsive gene network that is regulated by the master clock control gene CCA1.

PubMed

Gutiérrez, Rodrigo A; Stokes, Trevor L; Thum, Karen; Xu, Xiaodong; Obertello, Mariana; Katari, Manpreet S; Tanurdzic, Milos; Dean, Alexis; Nero, Damion C; McClung, C Robertson; Coruzzi, Gloria M

2008-03-25

Understanding how nutrients affect gene expression will help us to understand the mechanisms controlling plant growth and development as a function of nutrient availability. Nitrate has been shown to serve as a signal for the control of gene expression in Arabidopsis. There is also evidence, on a gene-by-gene basis, that downstream products of nitrogen (N) assimilation such as glutamate (Glu) or glutamine (Gln) might serve as signals of organic N status that in turn regulate gene expression. To identify genome-wide responses to such organic N signals, Arabidopsis seedlings were transiently treated with ammonium nitrate in the presence or absence of MSX, an inhibitor of glutamine synthetase, resulting in a block of Glu/Gln synthesis. Genes that responded to organic N were identified as those whose response to ammonium nitrate treatment was blocked in the presence of MSX. We showed that some genes previously identified to be regulated by nitrate are under the control of an organic N-metabolite. Using an integrated network model of molecular interactions, we uncovered a subnetwork regulated by organic N that included CCA1 and target genes involved in N-assimilation. We validated some of the predicted interactions and showed that regulation of the master clock control gene CCA1 by Glu or a Glu-derived metabolite in turn regulates the expression of key N-assimilatory genes. Phase response curve analysis shows that distinct N-metabolites can advance or delay the CCA1 phase. Regulation of CCA1 by organic N signals may represent a novel input mechanism for N-nutrients to affect plant circadian clock function.

Understanding the importance of the temperature dependence of viscosity on the crystallization dynamics in the Ge2Sb2Te5 phase-change material

NASA Astrophysics Data System (ADS)

Aladool, A.; Aziz, M. M.; Wright, C. D.

2017-06-01

The crystallization dynamics in the phase-change material Ge2Sb2Te5 is modelled using the more detailed Master equation method over a wide range of heating rates commensurate with published ultrafast calorimetry experiments. Through the attachment and detachment of monomers, the Master rate equation naturally traces nucleation and growth of crystallites with temperature history to calculate the transient distribution of cluster sizes in the material. Both the attachment and detachment rates in this theory are strong functions of viscosity, and thus, the value of viscosity and its dependence on temperature significantly affect the crystallization process. In this paper, we use the physically realistic Mauro-Yue-Ellison-Gupta-Allan viscosity model in the Master equation approach to study the role of the viscosity model parameters on the crystallization dynamics in Ge2Sb2Te5 under ramped annealing conditions with heating rates up to 4 × 104 K/s. Furthermore, due to the relatively low computational cost of the Master equation method compared to atomistic level computations, an iterative numerical approach was developed to fit theoretical Kissinger plots simulated with the Master equation system to experimental Kissinger plots from ultrafast calorimetry measurements at increasing heating rates. This provided a more rigorous method (incorporating both nucleation and growth processes) to extract the viscosity model parameters from the analysis of experimental data. The simulations and analysis revealed the strong coupling between the glass transition temperature and fragility index in the viscosity and crystallization models and highlighted the role of the dependence of the glass transition temperature on the heating rate for the accurate estimation of the fragility index of phase-change materials from the analysis of experimental measurements.

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).

Relation between muscle mass, motor units and type of training in master athletes.

PubMed

Drey, Michael; Sieber, Cornel C; Degens, Hans; McPhee, Jamie; Korhonen, Marko T; Müller, Klaus; Ganse, Bergita; Rittweger, Jörn

2016-01-01

The aim of this study was to measure the number of motor units and muscle mass in power-trained and endurance-trained master athletes compared with community-dwelling older adults. Seventy-five master athletes (52 power- and 23 endurance-trained athletes) were recruited at the 2012 European Veteran Athletics Championships in Zittau (Germany). One hundred and forty-nine community-dwelling older adults served as controls. In all participants, the motor unit number index (MUNIX) in the hypothenar muscle and whole body muscle mass was determined by bioelectrical impedance analysis (BIA). In both male and female master athletes, there were significant negative correlations between age and muscle mass (female: r = -0·510, P = 0·002; male: r = -0·714, P<0·001). Master athletes showed a weak correlation (r = -0·295, P = 0·010) between MUNIX and age. Master athletes exhibited significantly higher values than the control group with regard to both muscle mass (P = 0·002) and motor units (P = 0·004). Subanalysis showed that only power trained master athletes had both a larger muscle mass (P<0·001) and a higher MUNIX (P = 0·014) than the control group. Among the master athletes, power-trained athletes had a larger (P<0·001) muscle mass than endurance-trained athletes. The present data of master athletes are compatible with the hypothesis of an age-related decline in whole body muscle mass and motor units. Nevertheless, the data suggest that the master athletes' high level of physical activity may protect motoneurons. In addition, power training seems to have a positive effect on muscle mass and could therefore be an effective method of training to prevent sarcopenia. © 2014 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

Elastic modulus and surface tension of a polyurethane rubber in nanometer thick films

NASA Astrophysics Data System (ADS)

Zhai, Meiyu; McKenna, Gregory

2014-03-01

Estane is a kind of polyurethane with thermodynamically incompatible hard and soft segments. In this study the macro and micro properties of Estane have been characterized and compared. The viscoelastic properties of this material in bulk scale have been determined using dynamic rheometry. Time-temperature superposition was found to be applicable for this material, and a master curve was successfully constructed from the dynamic shear responses of G'(ω) and G''(ω) . Also a novel nano bubble inflation method was used to obtain the creep compliance of the Estane ultrathin films and the results show stiffening in the rubbery region for the Estane over thicknesses ranging from 110nm to 22nm. The dependence of the rubbery stiffening on film thickness is studied and the relative influences of nano confinement and surface tension effect are analyzed using both a direct stress strain analysis and an energy balance method for the membrane. The contributions of surface tension and nano confinement are considered separately. Office of Naval Research under project No.N00014-11-1-0424.

"I Am Different from Other Women in the World": The Experiences of Saudi Arabian Women Studying Online in International Master Programmes

ERIC Educational Resources Information Center

Szilagyi, Annamaria

2015-01-01

This paper presents findings from a qualitative study that investigated seven female Saudi Arabian students of the University of Liverpool's online Masters programmes. Qualitative, first-person research methods and hermeneutic phenomenology were chosen for the analysis and interpretation of transcripts (Langeveld, 1983; van Manen, 1997; Creswell,…

Are Public Master's Institutions Cost Efficient? A Stochastic Frontier and Spatial Analysis

ERIC Educational Resources Information Center

Titus, Marvin A.; Vamosiu, Adriana; McClure, Kevin R.

2017-01-01

The current study examines costs, measured by educational and general (E&G) spending, and cost efficiency at 252 public master's institutions in the United States over a nine-year (2004-2012) period. We use a multi-product quadratic cost function and results from a random-effects model with a first-order autoregressive (AR1) disturbance term…

Analysis of the Use of Twitter as a Learning Strategy in Master's Studies

ERIC Educational Resources Information Center

Feliz, Tiberio; Ricoy, Carmen; Feliz, Sálvora

2013-01-01

The present study analyses the use of Twitter in the course Social Media and Digital Learning, taught as part of a master's programme at Universidad Nacional de Educacion a Distancia (Spain). The main purpose of the use of this resource was to develop a learning community. This was implemented through the micro design of activities. A mixed…

[Professional Master's in Public Health: from legal precepts to experience in a research and education institution].

PubMed

dos Santos, Gideon Borges; Hortale, Virginia Alonso

2014-07-01

This study is about the discourses that prevailed over the course of time in Brazilian legislation for the Master's Course in Public Health, and how a Brazilian research and education institution in the area of Public Health appropriated these discourses in the creation of its course proposals. Discourse analysis techniques were applied to legal documents and to sixteen master's programs developed in the institution under scrutiny. The results revealed that with respect to legislation, analysis of the historical timeline makes it possible to say that the initial lack of definition progressively gave rise to the understanding that the identity of such post-graduate education presupposes pedagogical practices that promote the strengthening of ties between academia and the workplace. And, in relation to the master's course proposals for public health in the institutions under scrutiny, they still operate with traditionally consolidated training schemes and tend to standardize their proposals with those of the academic model. It was assumed in this study that the series of proposals would clearly mirror the intentions and, above all, the vision of the training institutions in the area of public health on this stricto sensu model, the identity of which also appears poorly defined.

CERT tribal internship program. Final intern report: David Conrad, 1993

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

NONE

1998-09-01

The intern`s report contains a Master`s thesis entitled, ``An implementation analysis of the US Department of Energy`s American Indian policy as part of its environmental restoration and waste management mission.`` This thesis examines the implementation of a working relationship between the Nez Perce Tribe and the US Department of Energy`s Office of Environmental Restoration and Waste Management at the Hanford reservation. It examines the relationship using a qualitative methodology and three generations of policy analysis literature to gain a clear understanding of the potential for successful implementation.

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.

Sport commitment and participation in masters swimmers: the influence of coach and teammates.

PubMed

Santi, Giampaolo; Bruton, Adam; Pietrantoni, Luca; Mellalieu, Stephen

2014-01-01

This study investigated how coach and teammates influence masters athletes' sport commitment, and the effect of functional and obligatory commitments on participation in masters swimming. The sample consisted of 523 masters swimmers (330 males and 193 females) aged between 22 and 83 years (M = 39.00, SD = 10.42). A bi-dimensional commitment scale was used to measure commitment dimensions and perceived influence from social agents. Structural equation modelling analysis was conducted to evaluate the influence of social agents on functional and obligatory commitments, and the predictive capabilities of the two types of commitment towards sport participation. Support provided by coach and teammates increased functional commitment, constraints from these social agents determined higher obligatory commitment, and coach constraints negatively impacted functional commitment. In addition, both commitment types predicted training participation, with functional commitment increasing participation in team training sessions, and obligatory commitment increasing the hours of individual training. The findings suggest that in order to increase participation in masters swimming teams and reduce non-supervised training, coach and teammates should exhibit a supportive attitude and avoid over expectation.

The impact of Masters education in manual and manipulative therapy and the 'knowledge acquisition model'.

PubMed

Perry, Jo; Green, Ann; Harrison, Karen

2011-06-01

This study aimed to explore the professional and personal impact that a clinical Masters program of manipulative therapy education had on the lives of individuals who had undertaken the course and was a follow-on study of participants' career pathways following Masters education (Green et al., 2008). Seven graduates from the program took part in a focus group. The narrative data obtained was independently verified prior to two researchers conducting a systematic, thematic content analysis. Three key themes were identified and the 'knowledge acquisition model' developed. Findings revealed that studying at Master's level is a 'life changing' and rewarding experience that develops individuals in three key domains; professionally, personally and intellectually. During Masters education students described a journey of multi-compartmental development whereby their knowledge-base was challenged and their existing cognitive framework deconstructed. Progression through the program resulted in the development of a new, clearer framework for thinking and understanding that extended, universally, into all aspects of their lives; clinically, managerially, emotionally, politically and intellectually. Participants also described two cultures for career progression in the UK National Health Service (NHS). Findings could help students considering undertaking Masters level education, employers and clinical mentors of these practitioners and academic educators. Copyright © 2010 Elsevier Ltd. All rights reserved.

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.

3D printed cellular solid outperforms traditional stochastic foam in long-term mechanical response

NASA Astrophysics Data System (ADS)

Maiti, A.; Small, W.; Lewicki, J. P.; Weisgraber, T. H.; Duoss, E. B.; Chinn, S. C.; Pearson, M. A.; Spadaccini, C. M.; Maxwell, R. S.; Wilson, T. S.

2016-04-01

3D printing of polymeric foams by direct-ink-write is a recent technological breakthrough that enables the creation of versatile compressible solids with programmable microstructure, customizable shapes, and tunable mechanical response including negative elastic modulus. However, in many applications the success of these 3D printed materials as a viable replacement for traditional stochastic foams critically depends on their mechanical performance and micro-architectural stability while deployed under long-term mechanical strain. To predict the long-term performance of the two types of foams we employed multi-year-long accelerated aging studies under compressive strain followed by a time-temperature-superposition analysis using a minimum-arc-length-based algorithm. The resulting master curves predict superior long-term performance of the 3D printed foam in terms of two different metrics, i.e., compression set and load retention. 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, which might explain the latter’s improved long-term stability and mechanical performance.

3D printed cellular solid outperforms traditional stochastic foam in long-term mechanical response

PubMed Central

Maiti, A.; Small, W.; Lewicki, J. P.; Weisgraber, T. H.; Duoss, E. B.; Chinn, S. C.; Pearson, M. A.; Spadaccini, C. M.; Maxwell, R. S.; Wilson, T. S.

2016-01-01

3D printing of polymeric foams by direct-ink-write is a recent technological breakthrough that enables the creation of versatile compressible solids with programmable microstructure, customizable shapes, and tunable mechanical response including negative elastic modulus. However, in many applications the success of these 3D printed materials as a viable replacement for traditional stochastic foams critically depends on their mechanical performance and micro-architectural stability while deployed under long-term mechanical strain. To predict the long-term performance of the two types of foams we employed multi-year-long accelerated aging studies under compressive strain followed by a time-temperature-superposition analysis using a minimum-arc-length-based algorithm. The resulting master curves predict superior long-term performance of the 3D printed foam in terms of two different metrics, i.e., compression set and load retention. 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, which might explain the latter’s improved long-term stability and mechanical performance. PMID:27117858

Accuracy of 3D Imaging Software in Cephalometric Analysis

DTIC Science & Technology

2013-06-21

submitted to the Faculty of the Comprehensive Dentistry Graduate Program Naval Postgraduate Dental School Uniformed Services University of the Health...Sciences in partial fulfillment of the requirements of the degree of Master of Science in Oral Biology June 2013 Naval Postgraduate Dental ...Master’s thesis of Bracken Robert Godfrey Lieutenant Commander, Dental Corps, U.S. Navy has been approved by the Examining Committee for the

Content Analysis of the Practicum Course in the Master of Science in Educational Leadership/Administration Program

ERIC Educational Resources Information Center

Norman, Scott W.

2013-01-01

In this study, I explored the overall efficacy of the Master of Science in Educational Leadership/ Administration (MSEL/A) program at Florida State University (FSU), by taking a closer look at the introductory course, Practicum in Educational Leadership (the Practicum), as well as the final assessment, the student e-portfolio. The MSEL/A at FSU is…

A Comparison of Classroom and Online Asynchronous Problem-Based Learning for Students Undertaking Statistics Training as Part of a Public Health Masters Degree

ERIC Educational Resources Information Center

de Jong, N.; Verstegen, D. M. L.; Tan, F. E. S.; O'Connor, S. J.

2013-01-01

This case-study compared traditional, face-to-face classroom-based teaching with asynchronous online learning and teaching methods in two sets of students undertaking a problem-based learning module in the multilevel and exploratory factor analysis of longitudinal data as part of a Masters degree in Public Health at Maastricht University. Students…

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.

The effect of using an inverted master cone in a lateral compaction technique on the density of the gutta-percha fill.

PubMed

Wu, Min-Kai; de Groot, Sjoerd D; van der Sluis, Luc W M; Wesselink, Paul R

2003-09-01

We sought to measure and calculate the percentage of the gutta-percha-filled area in the apical root canal after the use of a standardized or inverted master cone in cold lateral compaction.Study design Two groups of extracted mandibular premolars with a single canal were instrumented with instruments of the same size; furthermore, they were obturated with laterally compacted gutta-percha cones with AH26 used as a sealer. In the first group, a standardized master cone was used with its narrow end in an apical position, whereas in the other group, an inverted master cone was used with its wide end in an apical position. The 2 master cones had the same apical diameter and fit in the apical canal. After lateral compaction, horizontal sections were cut at a level 3 and 5 mm from the apex of each filled tooth. Photographs of the sections were taken by using a microscope equipped with a digital camera; the photos were then scanned as tagged-image file format images. The cross-sectional area of the canal and the gutta-percha were measured by using an image-analysis program. The percentage of gutta-percha-filled area was calculated. At both levels, the inverted master cone produced a significantly higher percentage, statistically, of gutta-percha-filled area than did the standardized master cone (P =.001 at 3 mm; P =.012 at 5 mm). The use of an inverted master cone in cold lateral compaction may facilitate the apical placement of accessory cones, significantly increasing the volume of gutta-percha while reducing the volume of sealer in the apical root canal.

Evaluating Spatiotemporal Image Correlation Technology as a Tool for Training Nonexpert Sonographers to Perform Examinations of the Fetal Heart.

PubMed

Avnet, Hagai; Mazaaki, Eyal; Shen, Ori; Cohen, Sarah; Yagel, Simcha

2016-01-01

We aimed to evaluate the use of spatiotemporal image correlation (STIC) as a tool for training nonexpert examiners to perform screening examinations of the fetal heart by acquiring and examining STIC volumes according to a standardized questionnaire based on the 5 transverse planes of the fetal heart. We conducted a prospective study at 2 tertiary care centers. Two sonographers without formal training in fetal echocardiography received theoretical instruction on the 5 fetal echocardiographic transverse planes, as well as STIC technology. Only women with conditions allowing 4-dimensional STIC volume acquisitions (grayscale and Doppler) were included in the study. Acquired volumes were evaluated offline according to a standardized protocol that required the trainee to mark 30 specified structures on 5 required axial planes. Volumes were then reviewed by an expert examiner for quality of acquisition and correct identification of specified structures. Ninety-six of 112 pregnant women examined entered the study. Patients had singleton pregnancies between 20 and 32 weeks' gestation. After an initial learning curve of 20 examinations, trainees succeeded in identifying 97% to 98% of structures, with a highly significant degree of agreement with the expert's analysis (P < .001). A median of 2 STIC volumes for each examination was necessary for maximal structure identification. Acquisition quality scores were high (8.6-8.7 of a maximal score of 10) and were found to correlate with identification rates (P = .017). After an initial learning curve and under expert guidance, STIC is an excellent tool for trainees to master extended screening examinations of the fetal heart.

First Job Search of Residents in the United States: A Survey of Anesthesiology Trainees' Interest in Academic Positions in Cities Distant from Previous Residences.

PubMed

Dexter, Franklin; De Oliveira, Gildasio S; McCarthy, Robert J

2016-01-15

We surveyed anesthesiology residents to evaluate the predictive effect of prior residence on desired location for future practice opportunities. One thousand five hundred United States anesthesiology residents were invited to participate. One question asked whether they intend to enter academic practice when they graduate from their residency/fellowship training. The analysis categorized the responses into "surely yes" and "probably" versus "even," "probably not," and "surely no." "After finishing your residency/fellowship training, are you planning to look seriously (e.g., interview) at jobs located more than a 2-hour drive from a location where you or your family (e.g., spouse or partner/significant other) have lived previously?" Responses were categorized into "very probably" and "somewhat probably" versus "somewhat improbably" and "not probable." Other questions explored predictors of the relationships quantified using the area under the receiver operating characteristic curve (area under the curve) ± its standard error. Among the 696 respondents, 36.9% (N = 256) would "probably" consider an academic practice. Fewer than half of those (P < 0.0001) would "very probably" consider a distant location (31.6%, 99% CI 24.4%-39.6%). Respondents with prior formal research training (e.g., PhD or Master's) had greater interest in academic practice at a distant location (AUC 0.63 ± 0.03, P = 0.0002). Except among respondents with formal research training, a good question to ask a job applicant is whether the applicant or the applicant's family has previously lived in the area.

Accuracy of axial length measurements obtained by optical biometry and acoustic biometry in rhegmatogenous retinal detachment: a prospective study.

PubMed

Pongsachareonnont, Pear; Tangjanyatam, Sagol

2018-01-01

We compared the accuracy of axial length (AL) measurement obtained by optical biometry with that obtained by acoustic biometry in eyes with rhegmatogenous retinal detachment (RRD). This prospective descriptive analytic study measured the AL of eyes with RRD preoperatively and 3 months postoperatively using optical biometry (intraocular lens [IOL] master group) and acoustic biometry (immersion A-scan group). Preoperative and postoperative measurements were compared by paired t -test. The agreement between preoperative and postoperative measurements was analyzed using a Bland-Altman plot. Subgroup analysis of macular involvement status was performed. Twenty-seven eyes were analyzed in this study. The mean AL in the IOL master group was 23.58±0.97 mm preoperatively and 24.17±1.16 mm postoperatively; the mean difference was -0.59±0.90 mm ( P = 0.007). The mean AL in the immersion A-scan group was 24.29±1.59 mm preoperatively and 24.27±1.69 mm postoperatively; the mean difference was 0.02±0.48 mm ( P = 0.827). Bland-Altman analysis revealed disagreement between preoperative and postoperative AL measurements in both techniques. In subgroup analysis of macula with RRD, there were significant differences between preoperative and postoperative AL measurements in the IOL master group ( P = 0.014). Significant underestimation of AL measurement was observed when using the IOL master in eyes with RRD with macular involvement, which could affect IOL power selection.

The Master level optics laboratory at the Institute of Optics

NASA Astrophysics Data System (ADS)

Adamson, Per

2017-08-01

The master level optics laboratory is a biannual, intensive laboratory course in the fields of geometrical, physical and modern optics. This course is intended for the master level student though Ph.D. advisors which often recommend it to their advisees. The students are required to complete five standard laboratory experiments and an independent project during a semester. The goals of the laboratory experiments are for the students to get hands-on experience setting up optical laboratory equipment, collecting and analyzing data, as well as to communicate key results. The experimental methods, analysis, and results of the standard experiments are submitted in a journal style report, while an oral presentation is given for the independent project.

Longevity of Single-Tooth All-Ceramic CAD/CAM Restorations: A Meta-Analysis

DTIC Science & Technology

2013-07-01

A thesis submitted to the Faculty of the Comprehensive Dentistry Graduate Program Naval Postgraduate Dental School Uniformed Services...Naval Postgraduate Dental School Uniformed Services University of the Health Sciences Bethesda, Maryland CERTIFICATE OF APPROVAL MASTER’S THESIS...This is to certify that the Master’s thesis of Katherine L. Cheng Lieutenant, Dental Corps, U.S. Navy has been approved by the Examining Committee for

Is the Glass Half-Full or Half-Empty? Perceptions of Recently-Qualified Educational Psychologists on the Effectiveness and Impact of Their Master's Level Research

ERIC Educational Resources Information Center

Landor, Miriam

2011-01-01

This paper reports the results of a small-scale study of the perceptions of recently-qualified educational psychologists (EPs) in Scotland about the effectiveness of their Master's level research and its impact on their own practice, on their service and on the wider educational psychology community. Thematic analysis of the data was carried out.…

Assessing the Progress and the Underlying Nature of the Flows of Doctoral and Master Degree Candidates Using Absorbing Markov Chains

ERIC Educational Resources Information Center

Nicholls, Miles G.

2007-01-01

In this paper, absorbing markov chains are used to analyse the flows of higher degree by research candidates (doctoral and master) within an Australian faculty of business. The candidates are analysed according to whether they are full time or part time. The need for such analysis stemmed from what appeared to be a rather poor completion rate (as…

Factors Influencing the Presence of Ethics and CSR Stand-Alone Courses in the Accounting Masters Curricula: An International Study

ERIC Educational Resources Information Center

Larrán Jorge, Manuel; Andrades Peña, Francisco Javier; Muriel de los Reyes, María José

2015-01-01

This paper provides a web-content analysis of the curriculum and subjects of the top accounting and auditing masters identified in the Eduniversal 2012-2013 ratings of the best business schools in the world. The main aim of this study is to analyze the influence exerted by different factors on the extent to which accounting programs are…

Remote detection of water stress in orchard canopies using MODIS/ASTER airborne simulator (MASTER) data

NASA Astrophysics Data System (ADS)

Cheng, Tao; Riaño, David; Koltunov, Alexander; Whiting, Michael L.; Ustin, Susan L.

2011-09-01

Vegetation canopy water content (CWC) is an important parameter for monitoring natural and agricultural ecosystems. Previous studies focused on the observation of annual or monthly variations in CWC but lacked temporal details to study vegetation physiological activities within a diurnal cycle. This study provides an evaluation of detecting vegetation diurnal water stress using airborne data acquired with the MASTER instrument. Concurrent with the morning and afternoon acquisitions of MASTER data, an extensive field campaign was conducted over almond and pistachio orchards in southern San Joaquin Valley of California to collect CWC measurements. Statistical analysis of the field measurements indicated a significant decrease of CWC from morning to afternoon. Field measured CWC was linearly correlated to the normalized difference infrared index (NDII) calculated with atmospherically corrected MASTER reflectance data using either FLAASH or empirical line (EL). Our regression analysis demonstrated that both atmospheric corrections led to a root mean square error (RMSE) of approximately 0.035 kg/m2 for the estimation of CWC (R2=0.42 for FLAASH images and R2=0.45 for EL images). Remote detection of the subtle decline in CWC awaits an improved prediction of CWC. Diurnal CWC maps revealed the spatial patterns of vegetation water status in response to variations in irrigation treatment.

[Post-graduate gerontology training in Spain: Number, characteristics, and contents taught in master courses].

PubMed

Villar, Feliciano; Giuliani, María Florencia; Serrat, Rodrigo

Population aging raises the need for specialised professionals to address the needs of the elderly. The aim of this paper is to describe the number, characteristics, and contents of the Master degree courses that are currently offered in Spain. There were 32 Master degree courses offered in the 2014-15 academic year. These required at least 60 ECTS (European Credit Transfer and Accumulation System). At least half of the course credits were based on contents directly related to old age, older people, or aging. An analysis was made that included, information on the institutional affiliation, official status, academic structure, and contents taught. A content analysis was performed on curriculum subjects, in order to classify the courses into multidisciplinary or specialised (with focus either on health, behavioural, or social sciences). Most of the courses required mandatory class attendance, and lasted one academic year (60 ECTS). They also included the completion of a final project and a practicum. The majority (59%) of Master degree courses were classified as multidisciplinary. Of the remaining ones, 19% were labelled as specialised in behavioural sciences, 16% in health sciences, and 2% in social sciences. The field of higher education in gerontology in Spain seems to be consolidated, taking into account indicators such as the number of courses offered, their territorial distribution, or the number of official Master degree courses. While the academic structure of the courses is quite similar, in contrast, their contents and nature are highly diverse, which responds to the different training needs. Copyright © 2016 SEGG. Publicado por Elsevier España, S.L.U. All rights reserved.

Master Equation Analysis of Thermal and Nonthermal Microwave Effects.

PubMed

Ma, Jianyi

2016-10-11

Master equation is a successful model to describe the conventional heating reaction, it is expanded to capture the "microwave effect" in this work. The work equation of "microwave effect" included master equation presents the direct heating, indirect heating, and nonthermal effect about the microwave field. The modified master equation provides a clear physics picture to the nonthermal microwave effect: (1) The absorption and the emission of the microwave, which is dominated by the transition dipole moment between two corresponding states and the intensity of the microwave field, provides a new path to change the reaction rate constants. (2) In the strong microwave field, the distribution of internal states of the molecules will deviate from the equilibrium distribution, and the system temperature defined in the conventional heating reaction is no longer available. According to the general form of "microwave effect" included master equation, a two states model for unimolecular dissociation is proposed and is used to discuss the microwave nonthermal effect particularly. The average rate constants can be increased up to 2400 times for some given cases without the temperature changed in the two states model. Additionally, the simulation of a model system was executed using our State Specified Master Equation package. Three important conclusions can be obtained in present work: (1) A reasonable definition of the nonthermal microwave effect is given in the work equation of "microwave effect" included master equation. (2) Nonthermal microwave effect possibly exists theoretically. (3) The reaction rate constants perhaps can be changed obviously by the microwave field for the non-RRKM and the mode-specified reactions.

Development of duplex real-time PCR for the detection of WSSV and PstDV1 in cultivated shrimp.

PubMed

Leal, Carlos A G; Carvalho, Alex F; Leite, Rômulo C; Figueiredo, Henrique C P

2014-07-05

The White spot syndrome virus (WSSV) and Penaeus stylirostris penstyldensovirus 1 (previously named Infectious hypodermal and hematopoietic necrosis virus-IHHNV) are two of the most important viral pathogens of penaeid shrimp. Different methods have been applied for diagnosis of these viruses, including Real-time PCR (qPCR) assays. A duplex qPCR method allows the simultaneous detection of two viruses in the same sample, which is more cost-effective than assaying for each virus separately. Currently, an assay for the simultaneous detection of the WSSV and the PstDV1 in shrimp is unavailable. The aim of this study was to develop and standardize a duplex qPCR assay for the simultaneous detection of the WSSV and the PstDV1 in clinical samples of diseased L. vannamei. In addition, to evaluate the performance of two qPCR master mixes with regard to the clinical sensitivity of the qPCR assay, as well as, different methods for qPCR results evaluation. The duplex qPCR assay for detecting WSSV and PstDV1 in clinical samples was successfully standardized. No difference in the amplification of the standard curves was observed between the duplex and singleplex assays. Specificities and sensitivities similar to those of the singleplex assays were obtained using the optimized duplex qPCR. The analytical sensitivities of duplex qPCR were two copies of WSSV control plasmid and 20 copies of PstDV1 control plasmid. The standardized duplex qPCR confirmed the presence of viral DNA in 28 from 43 samples tested. There was no difference for WSSV detection using the two kits and the distinct methods for qPCR results evaluation. High clinical sensitivity for PstDV1 was obtained with TaqMan Universal Master Mix associated with relative threshold evaluation. Three cases of simultaneous infection by the WSSV and the PstDV1 were identified with duplex qPCR. The standardized duplex qPCR was shown to be a robust, highly sensitive, and feasible diagnostic tool for the simultaneous detection of the WSSV and the PstDV1 in whiteleg shrimp. The use of the TaqMan Universal Master Mix and the relative threshold method of data analysis in our duplex qPCR method provided optimal levels of sensitivity and specificity.

Manufacturing complexity analysis

NASA Technical Reports Server (NTRS)

Delionback, L. M.

1977-01-01

The analysis of the complexity of a typical system is presented. Starting with the subsystems of an example system, the step-by-step procedure for analysis of the complexity of an overall system is given. The learning curves for the various subsystems are determined as well as the concurrent numbers of relevant design parameters. Then trend curves are plotted for the learning curve slopes versus the various design-oriented parameters, e.g. number of parts versus slope of learning curve, or number of fasteners versus slope of learning curve, etc. Representative cuts are taken from each trend curve, and a figure-of-merit analysis is made for each of the subsystems. Based on these values, a characteristic curve is plotted which is indicative of the complexity of the particular subsystem. Each such characteristic curve is based on a universe of trend curve data taken from data points observed for the subsystem in question. Thus, a characteristic curve is developed for each of the subsystems in the overall system.

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.

Extensions to decision curve analysis, a novel method for evaluating diagnostic tests, prediction models and molecular markers

PubMed Central

Vickers, Andrew J; Cronin, Angel M; Elkin, Elena B; Gonen, Mithat

2008-01-01

Background Decision curve analysis is a novel method for evaluating diagnostic tests, prediction models and molecular markers. It combines the mathematical simplicity of accuracy measures, such as sensitivity and specificity, with the clinical applicability of decision analytic approaches. Most critically, decision curve analysis can be applied directly to a data set, and does not require the sort of external data on costs, benefits and preferences typically required by traditional decision analytic techniques. Methods In this paper we present several extensions to decision curve analysis including correction for overfit, confidence intervals, application to censored data (including competing risk) and calculation of decision curves directly from predicted probabilities. All of these extensions are based on straightforward methods that have previously been described in the literature for application to analogous statistical techniques. Results Simulation studies showed that repeated 10-fold crossvalidation provided the best method for correcting a decision curve for overfit. The method for applying decision curves to censored data had little bias and coverage was excellent; for competing risk, decision curves were appropriately affected by the incidence of the competing risk and the association between the competing risk and the predictor of interest. Calculation of decision curves directly from predicted probabilities led to a smoothing of the decision curve. Conclusion Decision curve analysis can be easily extended to many of the applications common to performance measures for prediction models. Software to implement decision curve analysis is provided. PMID:19036144

Extensions to decision curve analysis, a novel method for evaluating diagnostic tests, prediction models and molecular markers.

PubMed

Vickers, Andrew J; Cronin, Angel M; Elkin, Elena B; Gonen, Mithat

2008-11-26

Decision curve analysis is a novel method for evaluating diagnostic tests, prediction models and molecular markers. It combines the mathematical simplicity of accuracy measures, such as sensitivity and specificity, with the clinical applicability of decision analytic approaches. Most critically, decision curve analysis can be applied directly to a data set, and does not require the sort of external data on costs, benefits and preferences typically required by traditional decision analytic techniques. In this paper we present several extensions to decision curve analysis including correction for overfit, confidence intervals, application to censored data (including competing risk) and calculation of decision curves directly from predicted probabilities. All of these extensions are based on straightforward methods that have previously been described in the literature for application to analogous statistical techniques. Simulation studies showed that repeated 10-fold crossvalidation provided the best method for correcting a decision curve for overfit. The method for applying decision curves to censored data had little bias and coverage was excellent; for competing risk, decision curves were appropriately affected by the incidence of the competing risk and the association between the competing risk and the predictor of interest. Calculation of decision curves directly from predicted probabilities led to a smoothing of the decision curve. Decision curve analysis can be easily extended to many of the applications common to performance measures for prediction models. Software to implement decision curve analysis is provided.

A Common Foundation of Information and Analytical Capability for AFSPC Decision Making

DTIC Science & Technology

2005-06-23

System Strategic Master Plan MAPs/MSP CRRAAF TASK FORCE CONOPS MUA Task Weights Engagement Analysis ASIIS Optimization ACEIT COST Analysis...Engangement Architecture Analysis Architecture MUA AFSPC POM S&T Planning Military Utility Analysis ACEIT COST Analysis Joint Capab Integ Develop System

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.

Analysis of a Proposed Material Handling System Using a Computer Simulation Model.

DTIC Science & Technology

1981-06-01

the proposed MMHS were identified to assist the managers of the system in implementation and future planning. * 4 UNCLASSIFIED SRCUllTY CLASSIPICATION...the Degree of Master of Science in Logistics Management By Darwin D. Harp, BSIE GS-11. June 1981 Approved for public release; distribution unlimited...partial fulfillment of the requirements for the degree of MASTER OF SCIENCE IN LOGISTICS MANAGEMENT DATE: 17 June 1981 (( COMMITECARN ii 67- B I

Consolidating Air Force Maintenance Occupational Specialties

DTIC Science & Technology

2016-01-01

Bill Gilbert . A number of colleagues at RAND, including John Drew, Laura Baldwin, Al Robbert, and Ray Conley, provided support during this effort...Massey, James M. Masters, Raymond A. Pyles, Ricardo Sanchez, Jerry M. Sollinger, Brent Thomas, Robert S. Tripp, and Ben D. Van Roo, Analysis of the Air...MG-872-AF, 2009), Tripp et al. (Robert S. Tripp, Ronald G. McGarvey, Ben D. Van Roo, James M. Masters and Jerry M. Sollinger. A Repair Network

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.

Distributed support vector machine in master-slave mode.

PubMed

Chen, Qingguo; Cao, Feilong

2018-05-01

It is well known that the support vector machine (SVM) is an effective learning algorithm. The alternating direction method of multipliers (ADMM) algorithm has emerged as a powerful technique for solving distributed optimisation models. This paper proposes a distributed SVM algorithm in a master-slave mode (MS-DSVM), which integrates a distributed SVM and ADMM acting in a master-slave configuration where the master node and slave nodes are connected, meaning the results can be broadcasted. The distributed SVM is regarded as a regularised optimisation problem and modelled as a series of convex optimisation sub-problems that are solved by ADMM. Additionally, the over-relaxation technique is utilised to accelerate the convergence rate of the proposed MS-DSVM. Our theoretical analysis demonstrates that the proposed MS-DSVM has linear convergence, meaning it possesses the fastest convergence rate among existing standard distributed ADMM algorithms. Numerical examples demonstrate that the convergence and accuracy of the proposed MS-DSVM are superior to those of existing methods under the ADMM framework. Copyright © 2018 Elsevier Ltd. All rights reserved.

Requirements Analysis Study for Master Pump Shutdown System Project Development Specification [SEC 1 and 2

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

BEVINS, R.R.

This document has been updated during the definitive design portion of the first phase of the W-314 Project to capture additional software requirements and is planned to be updated during the second phase of the W-314 Project to cover the second phase of the Project's scope. The objective is to provide requirement traceability by recording the analysis/basis for the functional descriptions of the master pump shutdown system. This document identifies the sources of the requirements and/or how these were derived. Each requirement is validated either by quoting the source or an analysis process involving the required functionality, performance characteristics, operationsmore » input or engineering judgment.« less

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.

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.

Transcriptional Network Analysis Identifies BACH1 as a Master Regulator of Breast Cancer Bone Metastasis

PubMed Central

Liang, Yajun; Wu, Heng; Lei, Rong; Chong, Robert A.; Wei, Yong; Lu, Xin; Tagkopoulos, Ilias; Kung, Sun-Yuan; Yang, Qifeng; Hu, Guohong; Kang, Yibin

2012-01-01

The application of functional genomic analysis of breast cancer metastasis has led to the identification of a growing number of organ-specific metastasis genes, which often function in concert to facilitate different steps of the metastatic cascade. However, the gene regulatory network that controls the expression of these metastasis genes remains largely unknown. Here, we demonstrate a computational approach for the deconvolution of transcriptional networks to discover master regulators of breast cancer bone metastasis. Several known regulators of breast cancer bone metastasis such as Smad4 and HIF1 were identified in our analysis. Experimental validation of the networks revealed BACH1, a basic leucine zipper transcription factor, as the common regulator of several functional metastasis genes, including MMP1 and CXCR4. Ectopic expression of BACH1 enhanced the malignance of breast cancer cells, and conversely, BACH1 knockdown significantly reduced bone metastasis. The expression of BACH1 and its target genes was linked to the higher risk of breast cancer recurrence in patients. This study established BACH1 as the master regulator of breast cancer bone metastasis and provided a paradigm to identify molecular determinants in complex pathological processes. PMID:22875853

Recession curve analysis for groundwater levels: case study in Latvia

NASA Astrophysics Data System (ADS)

Gailuma, A.; VÄ«tola, I.; Abramenko, K.; Lauva, D.; Vircavs, V.; Veinbergs, A.; Dimanta, Z.

2012-04-01

Recession curve analysis is powerful and effective analysis technique in many research areas related with hydrogeology where observations have to be made, such as water filtration and absorption of moisture, irrigation and drainage, planning of hydroelectric power production and chemical leaching (elution of chemical substances) as well as in other areas. The analysis of the surface runoff hydrograph`s recession curves, which is performed to conceive the after-effects of interaction of precipitation and surface runoff, has approved in practice. The same method for analysis of hydrograph`s recession curves can be applied for the observations of the groundwater levels. There are manually prepared hydrograph for analysis of recession curves for observation wells (MG2, BG2 and AG1) in agricultural monitoring sites in Latvia. Within this study from the available monitoring data of groundwater levels were extracted data of declining periods, splitted by month. The drop-down curves were manually (by changing the date) moved together, until to find the best match, thereby obtaining monthly drop-down curves, representing each month separately. Monthly curves were combined and manually joined, for obtaining characterizing drop-down curves of the year for each well. Within the process of decreased recession curve analysis, from the initial curve was cut out upward areas, leaving only the drops of the curve, consequently, the curve is transformed more closely to the groundwater flow, trying to take out the impact of rain or drought periods from the curve. Respectively, the drop-down curve is part of the data, collected with hydrograph, where data with the discharge dominates, without considering impact of precipitation. Using the recession curve analysis theory, ready tool "A Visual Basic Spreadsheet Macro for Recession Curve Analysis" was used for selection of data and logarithmic functions matching (K. Posavec et.al., GROUND WATER 44, no. 5: 764-767, 2006), as well as functions were developed by manual processing of data. For displaying data the mathematical model of data equalization was used, finding the corresponding or closest logarithmic function of the recession for the graph. Obtained recession curves were similar but not identical. With full knowledge of the fluctuations of ground water level, it is possible to indirectly (without taking soil samples) determine the filtration coefficient: more rapid decline in the recession curve correspond for the better filtration conditions. This research could be very useful in construction planning, road constructions, agriculture etc. Acknowledgments The authors gratefully acknowledge the funding from ESF Project "Establishment of interdisciplinary scientist group and modeling system for groundwater research" (Agreement No. 2009/0212/1DP/1.1.1.2.0/09/APIA/VIAA/060EF7)

Bayesian Inference and Application of Robust Growth Curve Models Using Student's "t" Distribution

ERIC Educational Resources Information Center

Zhang, Zhiyong; Lai, Keke; Lu, Zhenqiu; Tong, Xin

2013-01-01

Despite the widespread popularity of growth curve analysis, few studies have investigated robust growth curve models. In this article, the "t" distribution is applied to model heavy-tailed data and contaminated normal data with outliers for growth curve analysis. The derived robust growth curve models are estimated through Bayesian…

A clinical study relating CIELCH coordinates to the color dimensions of the 3D-Master System in a Spanish population.

PubMed

Gómez-Polo, Cristina; Gómez-Polo, Miguel; Celemín Viñuela, Alicia; Martínez Vázquez de Parga, Juan Antonio

2015-03-01

The 3D-Master System comprises 26 physical shade tabs and intermediate shades. Determining the relationship among all the groups of lightness, chroma, and hue of the 3D-Master System (Vita Zahnfabrik) and the L*, C*, and h* coordinates is important, because according to the manufacturer, 2 Toothguide 3D-Master shades need to be mixed in a 50:50 ratio to create an intermediate shade. The purpose of the study was to relate the lightness, chroma, and hue groups of the 3D-Master System with the polar coordinates of the CIELAB chromatic space, L*, C*, and h*, and to quantify the shades tabs and intermediate shades of the 3D-Master System according to color coordinates. The middle third of the facial surface of a natural maxillary central incisor was measured with an Easyshade Compact spectrophotometer (Vita Zahnfabrik) in 1361 Spanish participants aged between 16 and 89 years. Natural tooth color was recorded in the 3D-Master nomenclature and in the CIE L*, C*, and h* coordinates system. The program used for the present descriptive statistical analysis of the results was SAS 9.1.3. In the L* variable, the minimum was found at 47.0 and the maximum at 91.3. In the C* variable, the minimum was found at 5.9 and the maximum at 49.8, while for h*, the minimum was 67.5 degrees and the maximum 112.0 degrees. Despite the limitations of this study, the 3D-Master System was found to be arranged according to L*, C*, and h* coordinates in groups of lightness, chroma, and hue. The corresponding groups of lightness, chroma, and hue can be estimated on the basis of L*, C*, and h* coordinates. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Remote Sensing of the Radiative and Microphysical Properties of Clouds during TC4: Results from MAS, MASTER, MODIS, and MISR

NASA Technical Reports Server (NTRS)

King, Michael D.; Platnick, Steven; Wind, Galina; Arnold, George T.; Ackerman, Steven A.; Frey, Richard

2007-01-01

The MODIS Airborne Simulator (MAS) and MODIS/ASTER Airborne Simulator (MASTER) were used to obtain measurements of the bidirectional reflectance and brightness temperature of clouds at 50 discrete wavelengths between 0.47 and 14.3 (12.9 m for MASTER). These observations were obtained from the NASA ER-2 aircraft as part of the Tropical Composition, Clouds and Climate Coupling Experiment (TC4) conducted over Central America and surrounding Pacific and Atlantic Oceans between July 17 and August 8, 2007. Multispectral images in eight distinct bands were used to derive a confidence in clear sky (or alternatively the probability of cloud) over land and ocean ecosystems. Based on the results of individual tests run as part of this cloud mask, an algorithm was developed to estimate the phase of the clouds (liquid water, ice, or undetermined phase). Finally, the cloud optical thickness and effective radius were derived for both liquid water and ice clouds that were detected during each flight, using a nearly identical algorithm as that implemented operationally to process MODIS cloud data from the Aqua and Terra satellites (Collection 5). This analysis shows that the cloud mask developed for operational use on MODIS, and tested using MAS and MASTER date in TC4, is quite capable of distinguishing both liquid water and ice clouds during daytime conditions over both land and ocean. The cloud optical thickness and effective radius retrievals used three distinct bands of the MAS (or MASTER), and these results were compared with nearly simultaneous retrievals of MODIS on the Terra spacecraft. Finally, this MODIS-based algorithm was adapted to MISR data to infer the cloud optical thickness of liquid water clouds from MISR. Results of this analysis will be presented and discussed.

Master and novice secondary science teachers' understandings and use of the learning cycle

NASA Astrophysics Data System (ADS)

Reap, Melanie Ann

2000-09-01

The learning cycle paradigm had been used in science classrooms for nearly four decades. This investigation seeks to reveal how the 1earning cycle, as originally designed, is currently understood and implemented by teachers in authentic classroom settings. The specific purposes of this study were: (1) to describe teachers who use the learning cycle and compare their understandings and perceptions of the learning cycle procedure in instruction; (2) to elicit novice and master teacher perspectives on their instruction and determine their perception of the process by which learning cycles are implemented in the science classroom; (3) to describe the context of science instruction in the novice and master teacher's classroom to ascertain how the teacher facilitates implementation of the learning cycle paradigm in their authentic classroom setting. The study used a learning cycle survey, interviews and classroom observations using the Learning Cycle Teacher Behavior Instruments and the Verbal Interaction Category System to explore these features of learning cycle instruction. The learning cycle survey was administered to a sample of teachers who use the learning cycle, including master and novice learning cycle teachers. One master and one novice learning cycle teacher were selected from this sample for further study. Analysis of the surveys showed no significant differences in master and novice teacher understandings of the learning cycle as assessed by the instrument. However, interviews and observations of the selected master and novice learning cycle teachers showed several differences in how the paradigm is understood and implemented in the classroom. The master learning cycle teacher showed a more developed teaching philosophy and had more engaged, extensive interactions with students. The novice learning cycle teacher held a more naive teaching philosophy and had fewer, less developed interactions with students. The most significant difference was seen in the use of questioning and discussion. The master teacher used diverse questioning techniques and guided students in discussion of their findings while the novice teachers used more rote response questions and controlled the discussion. The findings of this study have implications for science teacher education, especially in the preparation of teachers in science methods courses and student teaching, and in in-service education programs.

Comparison of the Pentacam equivalent keratometry reading and IOL Master keratometry measurement in intraocular lens power calculations.

PubMed

Karunaratne, Nicholas

2013-12-01

To compare the accuracy of the Pentacam Holladay equivalent keratometry readings with the IOL Master 500 keratometry in calculating intraocular lens power. Non-randomized, prospective clinical study conducted in private practice. Forty-five consecutive normal patients undergoing cataract surgery. Forty-five consecutive patients had Pentacam equivalent keratometry readings at the 2-, 3 and 4.5-mm corneal zone and IOL Master keratometry measurements prior to cataract surgery. For each Pentacam equivalent keratometry reading zone and IOL Master measurement the difference between the observed and expected refractive error was calculated using the Holladay 2 and Sanders, Retzlaff and Kraff theoretic (SRKT) formulas. Mean keratometric value and mean absolute refractive error. There was a statistically significantly difference between the mean keratometric values of the IOL Master, Pentacam equivalent keratometry reading 2-, 3- and 4.5-mm measurements (P < 0.0001, analysis of variance). There was no statistically significant difference between the mean absolute refraction error for the IOL Master and equivalent keratometry readings 2 mm, 3 mm and 4.5 mm zones for either the Holladay 2 formula (P = 0.14) or SRKT formula (P = 0.47). The lowest mean absolute refraction error for Holladay 2 equivalent keratometry reading was the 4.5 mm zone (mean 0.25 D ± 0.17 D). The lowest mean absolute refraction error for SRKT equivalent keratometry reading was the 4.5 mm zone (mean 0.25 D ± 0.19 D). Comparing the absolute refraction error of IOL Master and Pentacam equivalent keratometry reading, best agreement was with Holladay 2 and equivalent keratometry reading 4.5 mm, with mean of the difference of 0.02 D and 95% limits of agreement of -0.35 and 0.39 D. The IOL Master keratometry and Pentacam equivalent keratometry reading were not equivalent when used only for corneal power measurements. However, the keratometry measurements of the IOL Master and Pentacam equivalent keratometry reading 4.5 mm may be similarly effective when used in intraocular lens power calculation formulas, following constant optimization. © 2013 Royal Australian and New Zealand College of Ophthalmologists.

Quantitative Analysis of Solid-State Homonuclear Correlation Spectra of Antiparallel β-Sheet Alanine Tetramers.

PubMed

Naito, Akira; Okushita, Keiko; Nishimura, Katsuyuki; Boutis, Gregory S; Aoki, Akihiro; Asakura, Tetsuo

2018-03-15

Poly-l-alanine (PLA) sequences are a key element in the structure of the crystalline domains of spider dragline silks, wild silkworm silks, antifreeze proteins, and amyloids. To date, no atomic-level structures of antiparallel (AP)-PLA longer than Ala 4 have been reported using the single-crystal X-ray diffraction analysis. In this work, dipolar-assisted rotational resonance solid-state NMR spectra were observed to determine the effective internuclear distances of 13 C uniformly labeled alanine tetramer with antiparallel (AP) β-sheet structure whose atomic coordinates are determined from the X-ray crystallographic analysis. Initial build-up rates, R j, k , were obtained from the build-up curves of the cross peaks by considering the internuclear distances arising in the master equation. Subsequently, experimentally obtained effective internuclear distances, r eff j, k (obs), were compared with the calculated r eff j, k (calc) values obtained from the X-ray crystallographic data. Fairly good correlation between r eff j, k (obs) and r eff j, k (calc) was obtained in the range of 1.0-6.0 Å, with the standard deviation of 0.244 Å, without considering the zero-quantum line-shape functions. It was further noted that the internuclear distances of intermolecular contributions provide details relating to the molecular packing in solid-state samples. Thus, the present data agree well with AP-β-sheet packing but do not agree with P-β-sheet packing.

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.

Evaluation of white-to-white distance and anterior chamber depth measurements using the IOL Master, slit-lamp adapted optical coherence tomography and digital photographs in phakic eyes.

PubMed

Wilczyński, Michał; Pośpiech-Zabierek, Aleksandra

2015-01-01

The accurate measurement of the anterior chamber internal diameter and depth is important in ophthalmic diagnosis and before some eye surgery procedures. The purpose of the study was to compare the white-to-white distance measurements performed using the IOL-Master and photography with internal anterior chamber diameter determined using slit lamp adapted optical coherence tomography in healthy eyes, and to compare anterior chamber depth measurements by IOL-Master and slit lamp adapted optical coherence tomography. The data were gathered prospectively from a non-randomized consecutive series of patients. The examined group consisted of 46 eyes of 39 patients. White-to-white was measured using IOL-Master and photographs of the eye were taken with a digital camera. Internal anterior chamber diameter was measured with slit-lamp adapted optical coherence tomography. Anterior chamber depth was measured using the IOL Master and slit-lamp adapted optical coherence tomography. Statistical analysis was performed using parametric tests. A Bland-Altman plot was drawn. White-to-white distance by the IOL Master was 11.8 +/- 0.40 mm, on photographs it was 11.29 +/- 0.58 mm and internal anterior chamber diameter by slit-lamp adapted optical coherence tomography was 11.34?0.54 mm. A significant difference was found between IOL-Master and slit-lamp adapted optical coherence tomography (p<0.01), as well as between IOL Master and digital photographs (p<0.01). There was no difference between SL-OCT and digital photographs (p>0.05). All measurements were correlated (Spearman p<0.001). Mean anterior chamber depth determined using the IOL-Master was 2.99 +/- 0.50 mm and by slit-lamp adapted optical coherence tomography was 2.56 +/- 0.46 mm. The difference was statistically significant (p<0.001). The correlation between the values was also statistically significant (Spearman, p<0.001). Automated measurements using IOL-Master yield constantly higher values than measurements based on direct eye visualization slit-lamp adapted optical coherence tomography and digital photographs. In order to obtain accurate measurements of the internal anterior chamber diameter and anterior chamber depth, a method involving direct visualization of intraocular structures should be used.

Arpit Bhatt | NREL

Science.gov Websites

Center to provide techno-economic analysis for advanced biofuel production designs. He holds a Master of pollutant modeling Research Interests Sustainability analysis Techno-economic analysis Air pollutant ., Heath, G. Economic implications of incorporating emission controls to mitigate air pollutants emitted

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

[Health system research in the Republic of Croatia 1990-2010].

PubMed

Kovacević, Jasmina; Sogorić, Selma; Dzakula, Aleksandar

2010-12-01

The aim of this study was to determine the scope and contents of peer-reviewed scientific publications that bring the results of the Health System Research (HSR) in the Republic of Croatia during the 1990-2010 period. The basic guidelines are in line with the research project, Health Services Research into European Policy and Practice (HSREPP). This project is being implemented with the aim of identifying, evaluating and improving the contribution of Health System Research to the development of Health Policy in Europe. This study included scientific publications indexed in the PubMed database and master theses and doctoral dissertations published at Schools of Medicine in Zagreb, Osijek, Rijeka and Split during the 1990-2010 period. In accordance with the project methodology, scientific publications indexed in PubMed (http://www.ncbi.nlm.nih.gov/pubmed) were searched for by the key words "Croatia AND (Health Care System OR Health System OR Healthcare System)". Then, the database of scientific publications indexed in PubMed was narrowed by key words divided into 4 groups according to HSREPP instructions. The search for master theses and doctoral dissertations was carried out by direct inspection of the completed works in the library of Andrija Stampar School of Public Health, School of Medicine, University of Zagreb. Access to master theses and doctoral dissertations at the other three medical schools was done by the Internet. We analyzed the collected summaries of all publications, master theses and doctoral dissertations and excluded all those that did not correspond to our research. Using this method, we found a total of 536 publications indexed in PubMed-in, 70 master theses and 22 doctoral dissertations meeting the study criteria. For further analysis, we separately considered master theses and doctoral dissertations on the one side, and scientific publications indexed in PubMed on the other side. All papers were listed by the year of publication, the author and the means of publication. Upon inclusion of the key words, 277 papers met the required criteria. After abstract analysis, 158 PubMed indexed papers were found to meet all the criteria and addressed the Health System Research in Croatia. There was a significant increase in the number of published papers during the 5-year study period. Upon analysis of the summary contents of master theses and doctoral dissertations, we separated 6 doctoral dissertations and 35 master theses that met the criteria of the research. They were divided into four groups: research of macro-, mezzo- and micro-level of Health System and assessment of Health Care System results. The group investigating the organization and delivery of health services (meso-level) and the group investigating health technology assessment (micro/meso-level) predominated. There were only a small number of high quality researches dealing with HSR in Croatia. Descriptive approach to the analysis predominated. Reform interventions require research, but are not part of the designed strategy. Funding of HSR is an important issue. The research in Croatia is financed by the Croatian Ministry of Science, Education and Sports. In the UK and the USA, HSR is funded by the National Health Services. In all publications, we could not find a systematic research of the Health System; however, we recognized a growing trend in the number of articles dealing with HSR in Croatia over the past 20 years. Comparison of the number of papers on the Health Care System in Croatia indicated a significant lag in comparison to Western Europe, and similarity with the countries of Eastern Europe.

Load Sharing Behavior of Star Gearing Reducer for Geared Turbofan Engine

NASA Astrophysics Data System (ADS)

Mo, Shuai; Zhang, Yidu; Wu, Qiong; Wang, Feiming; Matsumura, Shigeki; Houjoh, Haruo

2017-07-01

Load sharing behavior is very important for power-split gearing system, star gearing reducer as a new type and special transmission system can be used in many industry fields. However, there is few literature regarding the key multiple-split load sharing issue in main gearbox used in new type geared turbofan engine. Further mechanism analysis are made on load sharing behavior among star gears of star gearing reducer for geared turbofan engine. Comprehensive meshing error analysis are conducted on eccentricity error, gear thickness error, base pitch error, assembly error, and bearing error of star gearing reducer respectively. Floating meshing error resulting from meshing clearance variation caused by the simultaneous floating of sun gear and annular gear are taken into account. A refined mathematical model for load sharing coefficient calculation is established in consideration of different meshing stiffness and supporting stiffness for components. The regular curves of load sharing coefficient under the influence of interactions, single action and single variation of various component errors are obtained. The accurate sensitivity of load sharing coefficient toward different errors is mastered. The load sharing coefficient of star gearing reducer is 1.033 and the maximum meshing force in gear tooth is about 3010 N. This paper provides scientific theory evidences for optimal parameter design and proper tolerance distribution in advanced development and manufacturing process, so as to achieve optimal effects in economy and technology.

Requirements Analysis Study for Master Pump Shutdown System Project Development Specification [SEC 1 and 2

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

BEVINS, R.R.

This study is a requirements document that presents analysis for the functional description for the master pump shutdown system. This document identifies the sources of the requirements and/or how these were derived. Each requirement is validated either by quoting the source or an analysis process involving the required functionality, performance characteristics, operations input or engineering judgment. The requirements in this study apply to the first phase of the W314 Project. This document has been updated during the definitive design portion of the first phase of the W314 Project to capture additional software requirements and is planned to be updated duringmore » the second phase of the W314 Project to cover the second phase of the project's scope.« less

Digital tape unit test facility software

NASA Technical Reports Server (NTRS)

Jackson, J. T.

1971-01-01

Two computer programs are described which are used for the collection and analysis of data from the digital tape unit test facility (DTUTF). The data are the recorded results of skew tests made on magnetic digital tapes which are used on computers as input/output media. The results of each tape test are keypunched onto an 80 column computer card. The format of the card is checked and the card image is stored on a master summary tape via the DTUTF card checking and tape updating system. The master summary tape containing the results of all the tape tests is then used for analysis as input to the DTUTF histogram generating system which produces a histogram of skew vs. date for selected data, followed by some statistical analysis of the data.

Preparation of Al-Ti Master Alloys by Aluminothermic Reduction of TiO2 in Cryolite Melts at 960°C

NASA Astrophysics Data System (ADS)

Liu, Aimin; Xie, Kaiyu; Li, Liangxing; Shi, Zhongning; Hu, Xianwei; Xu, Junli; Gao, Bingliang; Wang, Zhaowen

Al-Ti master alloys were prepared by aluminothermic reduction between the dissolved titanium dioxide and aluminum in cryolite melts at 960°C. The kinetic analysis by differential scanning calorimetry indicated that the apparent activation energy of the reaction of reducing titanium dioxide by aluminium is 22.3 kJ/mol, and the reaction order is 0.5. The products were analyzed by means of X-ray diffraction, X-ray fluorescence, scanning electron microscopy and energy dispersive spectrometer. Results from X-ray diffraction showed that the phase compositions of produced alloys are Al and Al3Ti. In addition, Al-Ti master alloys containing 2-6 mass% Ti were formed at different reduction time of 2-5h in aluminothermic reduction experiment.

Using the weighted area under the net benefit curve for decision curve analysis.

PubMed

Talluri, Rajesh; Shete, Sanjay

2016-07-18

Risk prediction models have been proposed for various diseases and are being improved as new predictors are identified. A major challenge is to determine whether the newly discovered predictors improve risk prediction. Decision curve analysis has been proposed as an alternative to the area under the curve and net reclassification index to evaluate the performance of prediction models in clinical scenarios. The decision curve computed using the net benefit can evaluate the predictive performance of risk models at a given or range of threshold probabilities. However, when the decision curves for 2 competing models cross in the range of interest, it is difficult to identify the best model as there is no readily available summary measure for evaluating the predictive performance. The key deterrent for using simple measures such as the area under the net benefit curve is the assumption that the threshold probabilities are uniformly distributed among patients. We propose a novel measure for performing decision curve analysis. The approach estimates the distribution of threshold probabilities without the need of additional data. Using the estimated distribution of threshold probabilities, the weighted area under the net benefit curve serves as the summary measure to compare risk prediction models in a range of interest. We compared 3 different approaches, the standard method, the area under the net benefit curve, and the weighted area under the net benefit curve. Type 1 error and power comparisons demonstrate that the weighted area under the net benefit curve has higher power compared to the other methods. Several simulation studies are presented to demonstrate the improvement in model comparison using the weighted area under the net benefit curve compared to the standard method. The proposed measure improves decision curve analysis by using the weighted area under the curve and thereby improves the power of the decision curve analysis to compare risk prediction models in a clinical scenario.

Analysis and Recognition of Curve Type as The Basis of Object Recognition in Image

NASA Astrophysics Data System (ADS)

Nugraha, Nurma; Madenda, Sarifuddin; Indarti, Dina; Dewi Agushinta, R.; Ernastuti

2016-06-01

An object in an image when analyzed further will show the characteristics that distinguish one object with another object in an image. Characteristics that are used in object recognition in an image can be a color, shape, pattern, texture and spatial information that can be used to represent objects in the digital image. The method has recently been developed for image feature extraction on objects that share characteristics curve analysis (simple curve) and use the search feature of chain code object. This study will develop an algorithm analysis and the recognition of the type of curve as the basis for object recognition in images, with proposing addition of complex curve characteristics with maximum four branches that will be used for the process of object recognition in images. Definition of complex curve is the curve that has a point of intersection. By using some of the image of the edge detection, the algorithm was able to do the analysis and recognition of complex curve shape well.

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.

Acid-base properties of brown seaweed biomass considered as a Donnan gel. A model reflecting electrostatic effects and chemical heterogeneity.

PubMed

Rey-Castro, Carlos; Lodeiro, Pablo; Herrero, Roberto; Sastre de Vicente, Manuel E

2003-11-15

Brown seaweeds are interesting materials to be used as biosorbents for heavy metals due to their high binding ability and low cost. The study of the passive biosorption of protons on this kind of materials and its dependency on pH, ionic strength, and medium composition is essential for the practical application of brown algae in wastewater treatment. This work reports the results of the study of the proton binding equilibria of dead biomass from the seaweeds Sargassum muticum, Cystoseira baccata, and Saccorhiza polyschides by potentiometric titration with a glass electrode in the pH range between 2 and 8. Two different salts, NaCl and KNO3, in concentrations ranging from 0.05 to 2 mol x L(-1), were used as background electrolytes. The influence of the ionic strength was accounted for by means of the Donnan model in combination with the master curve approach. Different empirical expressions to describe the swelling behavior of the biosorbent were tested. On the basis of the intrinsic affinity distribution analysis a unimodal Langmuir-Freundlich isotherm was selected to describe the proton binding properties. The results show very little influence of the type of salt. The ionic strength dependency of the proton binding is very similar for the three species, and average empirical expressions of the Donnan volume are proposed. The maximum proton binding capacities obtained ranged between 2.4 and 2.9 mol x kg(-1), with average intrinsic proton affinity constants between 3.1 and 3.3, and heterogeneity parameters of ca. 0.5 for S. muticum and C. baccata, and slightly higher (ca. 0.7) for S. polyschides. The combined Langmuir-Freundlich equation and Donnan model allowed a good description of the experimental charge vs pH curves obtained.

Virtual reality robotic surgical simulation: an analysis of gynecology trainees.

PubMed

Sheth, Sangini S; Fader, Amanda N; Tergas, Ana I; Kushnir, Christina L; Green, Isabel C

2014-01-01

To analyze the learning curves of gynecology trainees on several virtual reality da Vinci Skills Simulator exercises. Prospective cohort pilot study. Academic hospital-based gynecology training program. Novice robotic surgeons from a gynecology training program. Novice robotic surgeons from an academic gynecology training program completed 10 repetitions of 4 exercises on the da Vinci Skills Simulator: matchboard, ring and rail, suture sponge, and energy switching. Performance metrics measured included time to completion, economy of instrument movement, excessive force, collisions, master workspace range, missed targets, misapplied energy, critical errors, and overall score. Statistical analyses were conducted to define the learning curve for trainees and the optimal number of repetitions for each exercise. A total of 34 participants were enrolled, of which 9 were medical students, 22 were residents, and 3 were fellows. There was a significant improvement in performance between the 1st and 10th repetitions across multiple metrics for all exercises. Senior trainees performed the suture exercise significantly faster than the junior trainees during the first and last repetitions (p = 0.004 and p = 0.003, respectively). However, the performance gap between seniors and juniors narrowed significantly by the 10th repetition. The mean number of repetitions required to achieve performance plateau ranged from 6.4 to 9.3. Virtual reality robotic simulation improves ability through repetition at all levels of training. Further, a performance plateau may exist during a single training session. Larger studies are needed to further define the most high-yield simulator exercises, the ideal number of repetitions, and recommended intervals between training sessions to improve operative performance. Copyright © 2014 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

The Effect of Size and Taper of Apical Preparation in Reducing Intra-Canal Bacteria: A Quantitative SEM Study.

PubMed

Mohammadzadeh Akhlaghi, Nahid; Rahimifard, Nahid; Moshari, Amirabbas; Vatanpour, Mehdi; Darmiani, Soheila

2014-01-01

Bacteria and their byproducts are major etiologic factors in endodontic diseases. Prevention or reduction of root canal bacterial contamination is the main aim of endodontic treatment. The purpose of this in vitro study was to evaluate the effect of size and taper of master apical file (MAF) in reducing bacteria from the apical third of the curved canals using a quantitative scanning electron microscope (SEM) study. Eighty-nine human mandibular first molars with curved MB canals (20(º)-35(º)) were divided into one control group (n=5) (without rotary instrumentation) and 6 experimental groups (n=14). The canals were prepared using RaCe rotary files to the MAF sizes 25/0.04, 25/0.06, 30/0.04, 30/0.06, 35/0.04 and 35/0.06, in groups 1 to 6, respectively. All the experimental groups were finally rinsed with 2 mL of 17% EDTA followed by 3 mL of 5.25% NaOCl. The mesial roots were split longitudinally. Remaining bacteria in the apical third of MB canals were evaluated using SEM (2000×). Data analysis was performed using one way ANOVA with Tukey's post hoc test. The level of significance was set at 0.05. All the experimental groups showed significant bacterial reduction (P<0.001). Although the greater size and/or taper resulted in decrease in bacteria, differences between the groups were not significant. Based on this in vitro study the MAF #25/0.04 had no significant difference compared to other groups with greater apical size/taper; all groups could effectively reduce intra-canal bacteria.

Master equation for a kinetic model of a trading market and its analytic solution

NASA Astrophysics Data System (ADS)

Chatterjee, Arnab; Chakrabarti, Bikas K.; Stinchcombe, Robin B.

2005-08-01

We analyze an ideal-gas-like model of a trading market with quenched random saving factors for its agents and show that the steady state income (m) distribution P(m) in the model has a power law tail with Pareto index ν exactly equal to unity, confirming the earlier numerical studies on this model. The analysis starts with the development of a master equation for the time development of P(m) . Precise solutions are then obtained in some special cases.

Effect of Dust Coagulation Dynamics on the Geometry of Aggregates

NASA Technical Reports Server (NTRS)

Nakamura, R.

1996-01-01

Master equation gives a more fundamental description of stochastic coagulation processes rather than popular Smoluchowski's equation. In order to examine the effect of the dynamics on the geometry of resulting aggregates, we study Master equation with a rigorous Monte Carlo algorithm. It is found that Cluster-Cluster aggregation model is a good approximation of orderly growth and the aggregates have fluffy structures with a fractal dimension approx. 2. A scaling analysis of Smoluchowski's equation also supports this conclusion.

Master equation for a kinetic model of a trading market and its analytic solution.

PubMed

Chatterjee, Arnab; Chakrabarti, Bikas K; Stinchcombe, Robin B

2005-08-01

We analyze an ideal-gas-like model of a trading market with quenched random saving factors for its agents and show that the steady state income (m) distribution P(m) in the model has a power law tail with Pareto index nu exactly equal to unity, confirming the earlier numerical studies on this model. The analysis starts with the development of a master equation for the time development of P(m) . Precise solutions are then obtained in some special cases.

Fourier's law of heat conduction: quantum mechanical master equation analysis.

PubMed

Wu, Lian-Ao; Segal, Dvira

2008-06-01

We derive the macroscopic Fourier's Law of heat conduction from the exact gain-loss time convolutionless quantum master equation under three assumptions for the interaction kernel. To second order in the interaction, we show that the first two assumptions are natural results of the long time limit. The third assumption can be satisfied by a family of interactions consisting of an exchange effect. The pure exchange model directly leads to energy diffusion in a weakly coupled spin- 12 chain.

[Oxidative stress in Masters swimmers following high-intensity (interval) training (HI(I)T)].

PubMed

Braun, Janina; Masoud, Magd; Brixius, Klara; Brinkmann, Christian

2016-05-01

Increased oxidative stress (OS) can promote diseases in the long term, but it can also trigger cellular adaptations in the short term. The present study aims to analyze whether a 3-month high-intensity (interval) training (HI(I)T) affects OS in 24 Masters swimmers (22-67 years) before (= basal) and after an all-out performance (swimming step-test). Data were analyzed for the entire group and differentiated according to sex and age (under 50 years (U50) and over 50 years (O50)). Prior to the HI(I)T intervention, a significant increase in OS from the basal to the all-out value was observed among the entire group and in the O50-subjects (subgroup analysis). Furthermore, significant increases in basal OS were evident for the entire group post-HI(I)T, but OS was only significantly increased in men in the subgroup analysis. No significant results were observed for women and U50-subjects. The response by Masters swimmers to HI(I)T depends on age and sex.

Prospects of In-Situ α-Al2O3 as an Inoculant in Aluminum: A Feasibility Study

NASA Astrophysics Data System (ADS)

Sreekumar, V. M.; Hari Babu, N.; Eskin, D. G.

2017-09-01

In-situ α-Al2O3 was successfully synthesized and dispersed in Al alloy using B2O3 and ultrasonication-aided liquid mixing technique. Microstructure analysis identified α-Al2O3 as the most common phase in the composite master alloy, whereas AlB12 was frequently observed and AlB2 was rarely found in the alloy. Grain refinement analysis of selected Al alloys registered a transition of columnar to equiaxial grains of α-Al with the inoculation of the master alloy and ultrasonication treatment. Similarly, an improvement in the mechanical properties of A357 alloy was observed with the combination of inoculation and ultrasonication treatment.

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

The Markov process admits a consistent steady-state thermodynamic formalism

NASA Astrophysics Data System (ADS)

Peng, Liangrong; Zhu, Yi; Hong, Liu

2018-01-01

The search for a unified formulation for describing various non-equilibrium processes is a central task of modern non-equilibrium thermodynamics. In this paper, a novel steady-state thermodynamic formalism was established for general Markov processes described by the Chapman-Kolmogorov equation. Furthermore, corresponding formalisms of steady-state thermodynamics for the master equation and Fokker-Planck equation could be rigorously derived in mathematics. To be concrete, we proved that (1) in the limit of continuous time, the steady-state thermodynamic formalism for the Chapman-Kolmogorov equation fully agrees with that for the master equation; (2) a similar one-to-one correspondence could be established rigorously between the master equation and Fokker-Planck equation in the limit of large system size; (3) when a Markov process is restrained to one-step jump, the steady-state thermodynamic formalism for the Fokker-Planck equation with discrete state variables also goes to that for master equations, as the discretization step gets smaller and smaller. Our analysis indicated that general Markov processes admit a unified and self-consistent non-equilibrium steady-state thermodynamic formalism, regardless of underlying detailed models.

When less is more: validating a brief scale to rate interprofessional team competencies.

PubMed

Lie, Désirée A; Richter-Lagha, Regina; Forest, Christopher P; Walsh, Anne; Lohenry, Kevin

2017-01-01

There is a need for validated and easy-to-apply behavior-based tools for assessing interprofessional team competencies in clinical settings. The seven-item observer-based Modified McMaster-Ottawa scale was developed for the Team Objective Structured Clinical Encounter (TOSCE) to assess individual and team performance in interprofessional patient encounters. We aimed to improve scale usability for clinical settings by reducing item numbers while maintaining generalizability; and to explore the minimum number of observed cases required to achieve modest generalizability for giving feedback. We administered a two-station TOSCE in April 2016 to 63 students split into 16 newly-formed teams, each consisting of four professions. The stations were of similar difficulty. We trained sixteen faculty to rate two teams each. We examined individual and team performance scores using generalizability (G) theory and principal component analysis (PCA). The seven-item scale shows modest generalizability (.75) with individual scores. PCA revealed multicollinearity and singularity among scale items and we identified three potential items for removal. Reducing items for individual scores from seven to four (measuring Collaboration, Roles, Patient/Family-centeredness, and Conflict Management) changed scale generalizability from .75 to .73. Performance assessment with two cases is associated with reasonable generalizability (.73). Students in newly-formed interprofessional teams show a learning curve after one patient encounter. Team scores from a two-station TOSCE demonstrate low generalizability whether the scale consisted of four (.53) or seven items (.55). The four-item Modified McMaster-Ottawa scale for assessing individual performance in interprofessional teams retains the generalizability and validity of the seven-item scale. Observation of students in teams interacting with two different patients provides reasonably reliable ratings for giving feedback. The four-item scale has potential for assessing individual student skills and the impact of IPE curricula in clinical practice settings. IPE: Interprofessional education; SP: Standardized patient; TOSCE: Team objective structured clinical encounter.

Housing, health and master planning: rules of engagement.

PubMed

Harris, P; Haigh, F; Thornell, M; Molloy, L; Sainsbury, P

2014-04-01

Knowledge about health focussed policy collaboration to date has been either tactical or technical. This article focusses on both technical and tactical issues to describe the experience of cross-sectoral collaboration between health and housing stakeholders across the life of a housing master plan, including but not limited to a health impact assessment (HIA). A single explanatory case study of collaboration on a master plan to regenerate a deprived housing estate in Western Sydney was developed to explain why and how the collaboration worked or did not work. Data collection included stakeholder interviews, document review, and reflections by the health team. Following a realist approach, data was analysed against established public policy theory dimensions. Tactically we did not know what we were doing. Despite our technical knowledge and skills with health focussed processes, particularly HIA, we failed to appreciate complexities inherent in master planning. This limited our ability to provide information at the right points. Eventually however the HIA did provide substantive connections between the master plan and health. We use our analysis to develop technical and tactical rules of engagement for future cross-sectoral collaboration. This case study from the field provides insight for future health focussed policy collaboration. We demonstrate the technical and tactical requirements for future intersectoral policy and planning collaborations, including HIAs, with the housing sector on master planning. The experience also suggested how HIAs can be conducted flexibly alongside policy development rather than at a specific point after a policy is drafted. Copyright © 2014 The Royal Society for Public Health. All rights reserved.

Light Water Reactor Sustainability Program Grizzly Year-End Progress Report

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

Benjamin Spencer; Yongfeng Zhang; Pritam Chakraborty

2013-09-01

The Grizzly software application is being developed under the Light Water Reactor Sustainability (LWRS) program to address aging and material degradation issues that could potentially become an obstacle to life extension of nuclear power plants beyond 60 years of operation. Grizzly is based on INL’s MOOSE multiphysics simulation environment, and can simultaneously solve a variety of tightly coupled physics equations, and is thus a very powerful and flexible tool with a wide range of potential applications. Grizzly, the development of which was begun during fiscal year (FY) 2012, is intended to address degradation in a variety of critical structures. Themore » reactor pressure vessel (RPV) was chosen for an initial application of this software. Because it fulfills the critical roles of housing the reactor core and providing a barrier to the release of coolant, the RPV is clearly one of the most safety-critical components of a nuclear power plant. In addition, because of its cost, size and location in the plant, replacement of this component would be prohibitively expensive, so failure of the RPV to meet acceptance criteria would likely result in the shutting down of a nuclear power plant. The current practice used to perform engineering evaluations of the susceptibility of RPVs to fracture is to use the ASME Master Fracture Toughness Curve (ASME Code Case N-631 Section III). This is used in conjunction with empirically based models that describe the evolution of this curve due to embrittlement in terms of a transition temperature shift. These models are based on an extensive database of surveillance coupons that have been irradiated in operating nuclear power plants, but this data is limited to the lifetime of the current reactor fleet. This is an important limitation when considering life extension beyond 60 years. The currently available data cannot be extrapolated with confidence further out in time because there is a potential for additional damage mechanisms (i.e. late blooming phases) to become active later in life beyond the current operational experience. To develop a tool that can eventually serve a role in decision-making, it is clear that research and development must be perfomed at multiple scales. At the engineering scale, a multiphysics analysis code that can capture the thermomechanical response of the RPV under accident conditions, including detailed fracture mechanics evaluations of flaws with arbitrary geometry and orientation, is needed to assess whether the fracture toughness, as defined by the master curve, including the effects of embrittlement, is exceeded. At the atomistic scale, the fundamental mechanisms of degradation need to be understood, including the effects of that degradation on the relevant material properties. In addition, there is a need to better understand the mechanisms leading to the transition from ductile to brittle fracture through improved continuum mechanics modeling at the fracture coupon scale. Work is currently being conducted at all of these levels with the goal of creating a usable engineering tool informed by lower length-scale modeling. This report summarizes progress made in these efforts during FY 2013.« less

Characterizing the Learning Curve of the VBLaST-PT© (Virtual Basic Laparoscopic Skill Trainer)

PubMed Central

Zhang, Likun; Sankaranarayanan, Ganesh; Arikatla, Venkata Sreekanth; Ahn, Woojin; Grosdemouge, Cristol; Rideout, Jesse M.; Epstein, Scott K.; De, Suvranu; Schwaitzberg, Steven D.; Jones, Daniel B.; Cao, Caroline G.L.

2013-01-01

Background and study aim Mastering laparoscopic surgical skills requires considerable time and effort. The Virtual Basic Laparoscopic Skill Trainer (VBLaST-PT©) is being developed as a computerized version of the peg transfer task of the Fundamentals of Laparoscopic Surgery (FLS) system using virtual reality technology. We assessed the learning curve of trainees on the VBLaST-PT© using the cumulative summation (CUSUM) method and compared them with those on the FLS to establish convergent validity for the VBLaST-PT©. Methods Eighteen medical students from were assigned randomly to one of three groups: control, VBLaST-training and FLS-training. The VBLaST and the FLS groups performed a total of 150 trials of the peg-transfer task over a three week period, five days a week. Their CUSUM scores were computed based on pre-defined performance criteria (junior, intermediate and senior levels). Results Of the six subjects in the VBLaST-training group, five achieved at least the “junior” level, three achieved the “intermediate” level and one achieved the “senior” level of performance criterion by the end of the 150 trials. In comparison, for the FLS group, three students achieved the “senior” criterion and all six students achieved the “intermediate” and “junior” criteria by the 150th trials. Both the VBLaST-PT© and the FLS systems showed significant skill improvement and retention, albeit with system specificity as measured by transfer of learning in the retention test: The VBLaST-trained group performed better on the VBLaST-PT© than on FLS (p=0.003), while the FLS-trained group performed better on the FLS than on VBLaST-PT© (p=0.002). Conclusion We characterized the learning curve for a virtual peg transfer task on the VBLaST-PT© and compared it with the FLS using CUSUM analysis. Subjects in both training groups showed significant improvement in skill performance, but the transfer of training between systems was not significant. PMID:23572217

A polymerase chain reaction-coupled high-resolution melting curve analytical approach for the monitoring of monospecificity of avian Eimeria species.

PubMed

Kirkpatrick, Naomi C; Blacker, Hayley P; Woods, Wayne G; Gasser, Robin B; Noormohammadi, Amir H

2009-02-01

Coccidiosis is a significant disease of poultry caused by different species of Eimeria. Differentiation of Eimeria species is important for the quality control of the live attenuated Eimeria vaccines derived from monospecific lines of Eimeria spp. In this study, high-resolution melting (HRM) curve analysis of the amplicons generated from the second internal transcribed spacer of nuclear ribosomal DNA (ITS-2) was used to distinguish between seven pathogenic Eimeria species of chickens, and the results were compared with those obtained from the previously described technique, capillary electrophoresis. Using a series of known monospecific lines of Eimeria species, HRM curve analysis was shown to distinguish between Eimeria acervulina, Eimeria brunetti, Eimeria maxima, Eimeria mitis, Eimeria necatrix, Eimeria praecox and Eimeria tenella. Computerized analysis of the HRM curves and capillary electrophoresis profiles could detect the dominant species in several specimens containing different ratios of E. necatrix and E. maxima and of E. tenella and E. acervulina. The HRM curve analysis identified all of the mixtures as "variation" to the reference species, and also identified the minor species in some mixtures. Computerized HRM curve analysis also detected impurities in 21 possible different combinations of the seven Eimeria species. The PCR-based HRM curve analysis of the ITS-2 provides a powerful tool for the detection and identification of pure Eimeria species. The HRM curve analysis could also be used as a rapid tool in the quality assurance of Eimeria vaccine production to confirm the purity of the monospecific cell lines. The HRM curve analysis is rapid and reliable and can be performed in a single test tube in less than 3 h.

Brownfields Samoa Peninsula Project: Phase I Sustainable Site Analysis Final Report

EPA Pesticide Factsheets

This report provides an analysis and scoring using the Leadership in Energy and Environmental Design, Neighborhood Development Rating System, and the Land and Natural Development Code in order to assess the proposed redevelopment a master plan.

On the accuracy of the Padé-resummed master equation approach to dissipative quantum dynamics

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

Chen, Hsing-Ta; Reichman, David R.; Berkelbach, Timothy C.

2016-04-21

Well-defined criteria are proposed for assessing the accuracy of quantum master equations whose memory functions are approximated by Padé resummation of the first two moments in the electronic coupling. These criteria partition the parameter space into distinct levels of expected accuracy, ranging from quantitatively accurate regimes to regions of parameter space where the approach is not expected to be applicable. Extensive comparison of Padé-resummed master equations with numerically exact results in the context of the spin–boson model demonstrates that the proposed criteria correctly demarcate the regions of parameter space where the Padé approximation is reliable. The applicability analysis we presentmore » is not confined to the specifics of the Hamiltonian under consideration and should provide guidelines for other classes of resummation techniques.« less

A comparative scanning electron microscopic study of the effect of three different rotary instruments on smear layer formation.

PubMed

Shahi, Shahriar; Yavari, Hamid R; Rahimi, Saeed; Reyhani, Mohammad F; Kamarroosta, Zahra; Abdolrahimi, Majid

2009-03-01

The aim of this study was to evaluate the effect of RaCe, FlexMaster and ProFile rotary instruments on smear layer formation by scanning electron microscopy. Eighty-four caries-free freshly extracted human single-rooted teeth were selected and divided into three groups, each containing 28 teeth. The teeth were instrumented with rotary instruments sequentially: Group A: ProFile Rotary Instruments; Group B: FlexMaster Rotary Instruments; and Group C: RaCe Rotary Instruments. Instrumentation was performed by the crown-down method and according to the manufacturer's instructions. The specimens were then examined with SEM according to Hülsmann's classification. One-way ANOVA and a post hoc Tukey test were used for statistical analysis. The results showed that there were no statistically significant differences among the three groups in the coronal third (P = 0.39), but at the apical and middle thirds there were statistically significant differences between the RaCe group and the other groups (P < 0.05). Smear layer in the RaCe group was less than that in the ProFile and FlexMaster groups, but the difference between the ProFile group and FlexMaster group was not statistically significant (P > 0.05). It was concluded that RaCe Rotary Instruments produce less smear layer than FlexMaster and ProFile Rotary Instruments.

Comparative Analysis of Enrollment and Financial Strength of Private Institutions. AIR 1989 Annual Forum Paper.

ERIC Educational Resources Information Center

Glover, Robert H.; Mills, Michael R.

A research design, decision support system, and results of a comparative analysis of enrollment and financial strength (of private institutions granting masters and doctoral degrees) are presented. Cluster analysis, discriminant analysis, multiple regression, and an interactive decision support system are used to compare the enrollment and…

Decision curve analysis revisited: overall net benefit, relationships to ROC curve analysis, and application to case-control studies.

PubMed

Rousson, Valentin; Zumbrunn, Thomas

2011-06-22

Decision curve analysis has been introduced as a method to evaluate prediction models in terms of their clinical consequences if used for a binary classification of subjects into a group who should and into a group who should not be treated. The key concept for this type of evaluation is the "net benefit", a concept borrowed from utility theory. We recall the foundations of decision curve analysis and discuss some new aspects. First, we stress the formal distinction between the net benefit for the treated and for the untreated and define the concept of the "overall net benefit". Next, we revisit the important distinction between the concept of accuracy, as typically assessed using the Youden index and a receiver operating characteristic (ROC) analysis, and the concept of utility of a prediction model, as assessed using decision curve analysis. Finally, we provide an explicit implementation of decision curve analysis to be applied in the context of case-control studies. We show that the overall net benefit, which combines the net benefit for the treated and the untreated, is a natural alternative to the benefit achieved by a model, being invariant with respect to the coding of the outcome, and conveying a more comprehensive picture of the situation. Further, within the framework of decision curve analysis, we illustrate the important difference between the accuracy and the utility of a model, demonstrating how poor an accurate model may be in terms of its net benefit. Eventually, we expose that the application of decision curve analysis to case-control studies, where an accurate estimate of the true prevalence of a disease cannot be obtained from the data, is achieved with a few modifications to the original calculation procedure. We present several interrelated extensions to decision curve analysis that will both facilitate its interpretation and broaden its potential area of application.

Decision curve analysis revisited: overall net benefit, relationships to ROC curve analysis, and application to case-control studies

PubMed Central

2011-01-01

Background Decision curve analysis has been introduced as a method to evaluate prediction models in terms of their clinical consequences if used for a binary classification of subjects into a group who should and into a group who should not be treated. The key concept for this type of evaluation is the "net benefit", a concept borrowed from utility theory. Methods We recall the foundations of decision curve analysis and discuss some new aspects. First, we stress the formal distinction between the net benefit for the treated and for the untreated and define the concept of the "overall net benefit". Next, we revisit the important distinction between the concept of accuracy, as typically assessed using the Youden index and a receiver operating characteristic (ROC) analysis, and the concept of utility of a prediction model, as assessed using decision curve analysis. Finally, we provide an explicit implementation of decision curve analysis to be applied in the context of case-control studies. Results We show that the overall net benefit, which combines the net benefit for the treated and the untreated, is a natural alternative to the benefit achieved by a model, being invariant with respect to the coding of the outcome, and conveying a more comprehensive picture of the situation. Further, within the framework of decision curve analysis, we illustrate the important difference between the accuracy and the utility of a model, demonstrating how poor an accurate model may be in terms of its net benefit. Eventually, we expose that the application of decision curve analysis to case-control studies, where an accurate estimate of the true prevalence of a disease cannot be obtained from the data, is achieved with a few modifications to the original calculation procedure. Conclusions We present several interrelated extensions to decision curve analysis that will both facilitate its interpretation and broaden its potential area of application. PMID:21696604

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.

Analysis of the accuracy and precision of the McMaster method in detection of the eggs of Toxocara and Trichuris species (Nematoda) in dog faeces.

PubMed

Kochanowski, Maciej; Dabrowska, Joanna; Karamon, Jacek; Cencek, Tomasz; Osiński, Zbigniew

2013-07-01

The aim of this study was to determine the accuracy and precision of McMaster method with Raynaud's modification in the detection of the eggs of the nematodes Toxocara canis (Werner, 1782) and Trichuris ovis (Abildgaard, 1795) in faeces of dogs. Four variants of McMaster method were used for counting: in one grid, two grids, the whole McMaster chamber and flotation in the tube. One hundred sixty samples were prepared from dog faeces (20 repetitions for each egg quantity) containing 15, 25, 50, 100, 150, 200, 250 and 300 eggs of T. canis and T. ovis in 1 g of faeces. To compare the influence of kind of faeces on the results, samples of dog faeces were enriched at the same levels with the eggs of another nematode, Ascaris suum Goeze, 1782. In addition, 160 samples of pig faeces were prepared and enriched only with A. suum eggs in the same way. The highest limit of detection (the lowest level of eggs that were detected in at least 50% of repetitions) in all McMaster chamber variants were obtained for T. canis eggs (25-250 eggs/g faeces). In the variant with flotation in the tube, the highest limit of detection was obtained for T. ovis eggs (100 eggs/g). The best results of the limit of detection, sensitivity and the lowest coefficients of variation were obtained with the use of the whole McMaster chamber variant. There was no significant impact of properties of faeces on the obtained results. Multiplication factors for the whole chamber were calculated on the basis of the transformed equation of the regression line, illustrating the relationship between the number of detected eggs and that of the eggs added to the'sample. Multiplication factors calculated for T. canis and T. ovis eggs were higher than those expected using McMaster method with Raynaud modification.

Methods of Technological Forecasting,

DTIC Science & Technology

1977-05-01

Trend Extrapolation Progress Curve Analogy Trend Correlation Substitution Analysis or Substitution Growth Curves Envelope Curve Advances in the State of...the Art Technological Mapping Contextual Mapping Matrix Input-Output Analysis Mathematical Models Simulation Models Dynamic Modelling. CHAPTER IV...Generation Interaction between Needs and Possibilities Map of the Technological Future — (‘ross- Impact Matri x Discovery Matrix Morphological Analysis

Material Analysis and Identification

NASA Technical Reports Server (NTRS)

2004-01-01

KeyMaster Technologies, Inc., develops and markets specialized, hand-held X-ray fluorescence (XRF) instruments and unique tagging technology used to identify and authenticate materials or processes. NASA first met with this Kennewick, Washington-based company as the Agency began seeking companies to develop a hand-held instrument that would detect data matrix symbols on parts covered by paint and other coatings. Since the Federal Aviation Administration was also searching for methods to detect and eliminate the use of unapproved parts, it recommended that NASA and KeyMaster work together to develop a technology that would benefit both agencies.

Challenges in Teaching Space Physics to Different Target Groups From Space Weather Forecasters to Heavy-weight Theorists

NASA Astrophysics Data System (ADS)

Koskinen, H. E.

2008-12-01

Plasma physics as the backbone of space physics is difficult and thus the space physics students need to have strong foundations in general physics, in particular in classical electrodynamics and thermodynamics, and master the basic mathematical tools for physicists. In many universities the number of students specializing in space physics at Master's and Doctoral levels is rather small and the students may have quite different preferences ranging from experimental approach to hard-core space plasma theory. This poses challenges in building up a study program that has both the variety and depth needed to motivate the best students to choose this field. At the University of Helsinki we require all beginning space physics students, regardless whether they enter the field as Master's or Doctoral degree students, to take a one-semester package consisting of plasma physics and its space applications. However, some compromises are necessary. For example, it is not at all clear, how thoroughly Landau damping should be taught at the first run or how deeply should the intricacies of collisionless reconnection be discussed. In both cases we have left the details to an optional course in advanced space physics, even with the risk that the student's appreciation of, e.g., reconnection may remain at the level of a magic wand. For learning experimental work, data analysis or computer simulations we have actively pursued arrangements for the Master's degree students to get a summer employments in active research groups, which usually lead to the Master's theses. All doctoral students are members of research groups and participate in experimental work, data analysis, simulation studies or theory development, or any combination of these. We emphasize strongly "learning by doing" all the way from the weekly home exercises during the lecture courses to the PhD theses which in Finland consist typically of 4-6 peer-reviewed articles with a comprehensive introductory part.

Systemic Microgravity Response: Utilizing GeneLab to Develop Hypotheses for Spaceflight Risks

NASA Technical Reports Server (NTRS)

Beheshti, Afshin; Fogle, Homer; Galazka, Jonathan; Kidane, Yared; Chakravarty, Kaushik; Berrios, Daniel C.; Costes, Sylvain V.

2017-01-01

Biological risks associated with microgravity is a major concern for space travel. Although determination of risk has been a focus for NASA research, data examining systemic (i.e., multi- or pan-tissue) responses to space flight are sparse. The overall goal of our work is to identify potential master regulators responsible for such responses to microgravity conditions. To do this we utilized the NASA GeneLab database which contains a wide array of omics experiments, including data from: 1) different flight conditions (space shuttle (STS) missions vs. International Space Station (ISS); 2) different tissues; and 3) different types of assays that measure epigenetic, transcriptional, and protein expression changes. We have performed meta-analysis identifying potential master regulators involved with systemic responses to microgravity. The analysis used 7 different murine and rat data sets, examining the following tissues: liver, kidney, adrenal gland, thymus, mammary gland, skin, and skeletal muscle (soleus, extensor digitorum longus, tibialis anterior, quadriceps, and gastrocnemius). Using a systems biology approach, we were able to determine that p53 and immune related pathways appear central to pan-tissue microgravity responses. Evidence for a universal response in the form of consistency of change across tissues in regulatory pathways was observed in both STS and ISS experiments with varying durations; while degree of change in expression of these master regulators varied across species and strain, some change in these master regulators was universally observed. Interestingly, certain skeletal muscle (gastrocnemius and soleus) show an overall down-regulation in these genes, while in other types (extensor digitorum longus, tibialis anterior and quadriceps) they are up-regulated, suggesting certain muscle tissues may be compensating for atrophy responses caused by microgravity. Studying these organtissue-specific perturbations in molecular signaling networks, we demonstrate the value of GeneLab in characterizing potential master regulators associated with biological risks for spaceflight.

Remote Sensing of Radiative and Microphysical Properties of Clouds During TC (sup 4): Results from MAS, MASTER, MODIS, and MISR

NASA Technical Reports Server (NTRS)

King, Michael D.; Platnick, Steven; Wind, Galina; Arnold, G. Thomas; Dominguez, Roseanne T.

2010-01-01

The Moderate Resolution Imaging Spectroradiometer (MODIS) Airborne Simulator (MAS) and MODIS/Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Airborne Simulator (MASTER) were used to obtain measurements of the bidirectional reflectance and brightness temperature of clouds at 50 discrete wavelengths between 0.47 and 14.2 microns (12.9 microns for MASTER). These observations were obtained from the NASA ER-2 aircraft as part of the Tropical Composition, Cloud and Climate Coupling (TC4) experiment conducted over Central America and surrounding Pacific and Atlantic Oceans between 17 July and 8 August 2007. Multispectral images in eleven distinct bands were used to derive a confidence in clear sky (or alternatively the probability Of cloud) over land and ocean ecosystems. Based on the results of individual tests run as part of the cloud mask, an algorithm was developed to estimate the phase of the clouds (liquid water, ice, or undetermined phase). The cloud optical thickness and effective radius were derived for both liquid water and ice clouds that were detected during each flight, using a nearly identical algorithm to that implemented operationally to process MODIS Cloud data from the Aqua and Terra satellites (Collection 5). This analysis shows that the cloud mask developed for operational use on MODIS, and tested using MAS and MASTER data in TC(sup 4), is quite capable of distinguishing both liquid water and ice clouds during daytime conditions over both land and ocean. The cloud optical thickness and effective radius retrievals use five distinct bands of the MAS (or MASTER), and these results were compared with nearly simultaneous retrievals of marine liquid water clouds from MODIS on the Terra spacecraft. Finally, this MODIS-based algorithm was adapted to Multiangle Imaging SpectroRadiometer (MISR) data to infer the cloud optical thickness Of liquid water clouds from MISR. Results of this analysis are compared and contrasted.

Expression of Master Regulators of T-cell, Helper T-cell and Follicular Helper T-cell Differentiation in Angioimmunoblastic T-cell Lymphoma.

PubMed

Matsumoto, Yosuke; Nagoshi, Hisao; Yoshida, Mihoko; Kato, Seiichi; Kuroda, Junya; Shimura, Kazuho; Kaneko, Hiroto; Horiike, Shigeo; Nakamura, Shigeo; Taniwaki, Masafumi

2017-11-01

Objective It has been postulated that the normal counterpart of angioimmunoblastic T-cell lymphoma (AITL) is the follicular helper T-cell (TFH). Recent immunological studies have identified several transcription factors responsible for T-cell differentiation. The master regulators associated with T-cell, helper T-cell (Th), and TFH differentiation are reportedly BCL11B, Th-POK, and BCL6, respectively. We explored the postulated normal counterpart of AITL with respect to the expression of the master regulators of T-cell differentiation. Methods We performed an immunohistochemical analysis in 15 AITL patients to determine the expression of the master regulators and several surface markers associated with T-cell differentiation. Results BCL11B was detected in 10 patients (67%), and the surface marker of T-cells (CD3) was detected in all patients. Only 2 patients (13%) expressed the marker of naïve T-cells (CD45RA), but all patients expressed the marker of effector T-cells (CD45RO). Nine patients expressed Th-POK (60%), and 7 (47%) expressed a set of surface antigens of Th (CD4-positive and CD8-negative). In addition, BCL6 and the surface markers of TFH (CXCL13, PD-1, and SAP) were detected in 11 (73%), 8 (53%), 14 (93%), and all patients, respectively. Th-POK-positive/BCL6-negative patients showed a significantly shorter overall survival (OS) than the other patients (median OS: 33.0 months vs. 74.0 months, p=0.020; log-rank test). Conclusion Many of the AITL patients analyzed in this study expressed the master regulators of T-cell differentiation. The clarification of the diagnostic significance and pathophysiology based on the expression of these master regulators in AITL is expected in the future.

Gene Scanning of an Internalin B Gene Fragment Using High-Resolution Melting Curve Analysis as a Tool for Rapid Typing of Listeria monocytogenes

PubMed Central

Pietzka, Ariane T.; Stöger, Anna; Huhulescu, Steliana; Allerberger, Franz; Ruppitsch, Werner

2011-01-01

The ability to accurately track Listeria monocytogenes strains involved in outbreaks is essential for control and prevention of listeriosis. Because current typing techniques are time-consuming, cost-intensive, technically demanding, and difficult to standardize, we developed a rapid and cost-effective method for typing of L. monocytogenes. In all, 172 clinical L. monocytogenes isolates and 20 isolates from culture collections were typed by high-resolution melting (HRM) curve analysis of a specific locus of the internalin B gene (inlB). All obtained HRM curve profiles were verified by sequence analysis. The 192 tested L. monocytogenes isolates yielded 15 specific HRM curve profiles. Sequence analysis revealed that these 15 HRM curve profiles correspond to 18 distinct inlB sequence types. The HRM curve profiles obtained correlated with the five phylogenetic groups I.1, I.2, II.1, II.2, and III. Thus, HRM curve analysis constitutes an inexpensive assay and represents an improvement in typing relative to classical serotyping or multiplex PCR typing protocols. This method provides a rapid and powerful screening tool for simultaneous preliminary typing of up to 384 samples in approximately 2 hours. PMID:21227395

Job satisfaction of nurses with master of nursing degrees in Poland: quantitative and qualitative analysis.

PubMed

Brayer, Aneta; Marcinowicz, Ludmila

2018-04-03

Understanding the issue of job satisfaction of nurses with master of nursing degrees may help develop organisational changes necessary for better functioning of health care institutions. This study aimed to evaluate the level of job satisfaction among holders of Masters of Nursing degrees employed at health care institutions and to ascertain its determinants. The cross-sectional study was carried out in randomly selected health care institutions in Poland using the Misener Nurse Practitioner Job Satisfaction Survey and an original survey questionnaire with two open-ended questions. Quantitative data were analysed using descriptive and summary statistics. The participants gave highest satisfaction ratings to their relationships with direct superiors and other nurses, as well as their social contacts at work. The lowest ratings were given to the pension scheme and factors connected with remuneration. A highly statistically significant relationship was found between the job classification and the level of professional satisfaction (p < 0.001). Qualitative analysis of responses to the two open-ended questions supported Herzberg's Two-Factor theory: internal factors promoted satisfaction, whilst external ones caused dissatisfaction. Managers of nurses should strengthen the areas that contribute to higher employee satisfaction, particularly interpersonal relationships, by commendation and recognition of work effects.

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.

Dissecting Embryonic Stem Cell Self-Renewal and Differentiation Commitment from Quantitative Models.

PubMed

Hu, Rong; Dai, Xianhua; Dai, Zhiming; Xiang, Qian; Cai, Yanning

2016-10-01

To model quantitatively embryonic stem cell (ESC) self-renewal and differentiation by computational approaches, we developed a unified mathematical model for gene expression involved in cell fate choices. Our quantitative model comprised ESC master regulators and lineage-specific pivotal genes. It took the factors of multiple pathways as input and computed expression as a function of intrinsic transcription factors, extrinsic cues, epigenetic modifications, and antagonism between ESC master regulators and lineage-specific pivotal genes. In the model, the differential equations of expression of genes involved in cell fate choices from regulation relationship were established according to the transcription and degradation rates. We applied this model to the Murine ESC self-renewal and differentiation commitment and found that it modeled the expression patterns with good accuracy. Our model analysis revealed that Murine ESC was an attractor state in culture and differentiation was predominantly caused by antagonism between ESC master regulators and lineage-specific pivotal genes. Moreover, antagonism among lineages played a critical role in lineage reprogramming. Our results also uncovered that the ordered expression alteration of ESC master regulators over time had a central role in ESC differentiation fates. Our computational framework was generally applicable to most cell-type maintenance and lineage reprogramming.

Classification of Fowl Adenovirus Serotypes by Use of High-Resolution Melting-Curve Analysis of the Hexon Gene Region▿

PubMed Central

Steer, Penelope A.; Kirkpatrick, Naomi C.; O'Rourke, Denise; Noormohammadi, Amir H.

2009-01-01

Identification of fowl adenovirus (FAdV) serotypes is of importance in epidemiological studies of disease outbreaks and the adoption of vaccination strategies. In this study, real-time PCR and subsequent high-resolution melting (HRM)-curve analysis of three regions of the hexon gene were developed and assessed for their potential in differentiating 12 FAdV reference serotypes. The results were compared to previously described PCR and restriction enzyme analyses of the hexon gene. Both HRM-curve analysis of a 191-bp region of the hexon gene and restriction enzyme analysis failed to distinguish a number of serotypes used in this study. In addition, PCR of the region spanning nucleotides (nt) 144 to 1040 failed to amplify FAdV-5 in sufficient quantities for further analysis. However, HRM-curve analysis of the region spanning nt 301 to 890 proved a sensitive and specific method of differentiating all 12 serotypes. All melt curves were highly reproducible, and replicates of each serotype were correctly genotyped with a mean confidence value of more than 99% using normalized HRM curves. Sequencing analysis revealed that each profile was related to a unique sequence, with some sequences sharing greater than 94% identity. Melting-curve profiles were found to be related mainly to GC composition and distribution throughout the amplicons, regardless of sequence identity. The results presented in this study show that the closed-tube method of PCR and HRM-curve analysis provides an accurate, rapid, and robust genotyping technique for the identification of FAdV serotypes and can be used as a model for developing genotyping techniques for other pathogens. PMID:19036935

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.

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.

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.

An Experimental and Master Equation Study of the Kinetics of OH/OD + SO2: The Limiting High-Pressure Rate Coefficients.

PubMed

Blitz, Mark A; Salter, Robert J; Heard, Dwayne E; Seakins, Paul W

2017-05-04

The kinetics of the reaction OH/OD + SO 2 were studied using a laser flash photolysis/laser-induced fluorescence technique. Evidence for two-photon photolysis of SO 2 at 248 nm is presented and quantified, and which appears to have been evident to some extent in most previous photolysis studies, potentially leading to values for the rate coefficient k 1 that are too large. The kinetics of the reaction OH(v = 0) + SO 2 (T = 295 K, p = 25-300 torr) were measured under conditions where SO 2 photolysis was taken into account. These results, together with literature data, were modeled using a master equation analysis. This analysis highlighted problems with the literature data: the rate coefficients derived from flash photolysis data were generally too high and from the flow tube data too low. Our best estimate of the high-pressure limiting rate coefficient k 1 ∞ was obtained from selected data and gives a value of (7.8 ± 2.2) × 10 -13 cm 3 molecule -1 s -1 , which is lower than that recommended in the literature. A parametrized form of k 1 ([N 2 ],T) is provided. The OD(v = 0) + SO 2 (T = 295 K, p = 25-300 torr) data are reported for the first time, and master equation analysis reinforces our assignment of k 1 ∞ .

Correlations among measures of knee stiffness, gait performance and complaints in individuals with knee osteoarthritis.

PubMed

Oatis, Carol A; Wolff, Edward F; Lockard, Margery A; Michener, Lori A; Robbins, Steven J

2013-03-01

Stiffness is a common complaint in individuals with knee osteoarthritis and is a component of the osteoarthritis diagnosis. Yet the relationship between stiffness and function is poorly understood and methods to quantify stiffness are limited. Using a cross-sectional observational design with 66 subjects with knee osteoarthritis, stiffness and damping coefficients were calculated from a relaxed knee oscillation procedure. Gait parameters were measured using an electronic walkway. Self-reported pain, stiffness, and function were measured with the Western Ontario and McMaster Osteoarthritis Index. Correlation and Alexander's normalized-t approximation analyses were used to assess associations among the variables. Subset analysis was performed on subjects with and without tibiofemoral joint crepitus. Slight to moderate correlations existed between stiffness and damping coefficients and most gait parameters ((| r |=0.30-0.56; P<.05) and between Western Ontario and McMaster Osteoarthritis Index scores and all gait parameters (| r |=0.35-0.62; P<.05). The damping coefficient was only slightly associated with patient-rated Western Ontario and McMaster Osteoarthritis Index stiffness subscale scores. Subset analysis revealed significant correlations that differed between those with and without crepitus. These findings suggest that laboratory measured stiffness and damping coefficients, Western Ontario and McMaster Osteoarthritis Index scores and gait-related measurements assess different aspects related to movement in individuals with knee osteoarthritis. Stiffness and damping coefficients may offer the ability to explain gait changes in the knee that are independent of a person's perceptions particularly in the early stages of the disease. Copyright © 2013 Elsevier Ltd. All rights reserved.

Thermoluminescence glow curve analysis and CGCD method for erbium doped CaZrO{sub 3} phosphor

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

Tiwari, Ratnesh, E-mail: 31rati@gmail.com; Chopra, Seema

2016-05-06

The manuscript report the synthesis, thermoluminescence study at fixed concentration of Er{sup 3+} (1 mol%) doped CaZrO{sub 3} phosphor. The phosphors were prepared by modified solid state reaction method. The powder sample was characterized by thermoluminescence (TL) glow curve analysis. In TL glow curve the optimized concentration in 1mol% for UV irradiated sample. The kinetic parameters were calculated by computerized glow curve deconvolution (CGCD) techniaue. Trapping parameters gives the information of dosimetry loss in prepared phosphor and its usability in environmental monitoring and for personal monitoring. CGCD is the advance tool for analysis of complicated TL glow curves.

Evidence-based selection process to the Master of Public Health program at Medical University.

PubMed

Panczyk, Mariusz; Juszczyk, Grzegorz; Zarzeka, Aleksander; Samoliński, Łukasz; Belowska, Jarosława; Cieślak, Ilona; Gotlib, Joanna

2017-09-11

Evaluation of the predictive validity of selected sociodemographic factors and admission criteria for Master's studies in Public Health at the Faculty of Health Sciences, Medical University of Warsaw (MUW). For the evaluation purposes recruitment data and learning results of students enrolled between 2008 and 2012 were used (N = 605, average age 22.9 ± 3.01). The predictive analysis was performed using the multiple linear regression method. In the proposed regression model 12 predictors were selected, including: sex, age, professional degree (BA), the Bachelor's studies grade point average (GPA), total score of the preliminary examination broken down into five thematic areas. Depending on the tested model, one of two dependent variables was used: first-year GPA or cumulative GPA in the Master program. The regression model based on the result variable of Master's GPA program was better matched to data in comparison to the model based on the first year GPA (adjusted R 2 0.413 versus 0.476 respectively). The Bachelor's studies GPA and each of the five subtests comprising the test entrance exam were significant predictors of success achieved by a student both after the first year and at the end of the course of studies. Criteria of admissions with total score of MCQs exam and Bachelor's studies GPA can be successfully used for selection of the candidates for Master's degree studies in Public Health. The high predictive validity of the recruitment system confirms the validity of the adopted admission policy at MUW.

Quality Assessment of College Admissions Processes.

ERIC Educational Resources Information Center

Fisher, Caroline; Weymann, Elizabeth; Todd, Amy

2000-01-01

This study evaluated the admissions process for a Master's in Business Administration Program using such quality improvement techniques as customer surveys, benchmarking, and gap analysis. Analysis revealed that student dissatisfaction with the admissions process may be a factor influencing declining enrollment. Cycle time and number of student…

Idea Notebook: Wilderness Food Planning in the Computer Age.

ERIC Educational Resources Information Center

Drury, Jack K.

1986-01-01

Explains the use of a computer as a planning and teaching tool in wilderness trip food planning. Details use of master food list and spreadsheet software such as VisiCalc to provide shopping lists for food purchasing, cost analysis, and diet analysis. (NEC)

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.

Surgical ergonomics. Analysis of technical skills, simulation models and assessment methods.

PubMed

Papaspyros, Sotiris C; Kar, Ashok; O'Regan, David

2015-06-01

Over the past two centuries the surgical profession has undergone a profound evolution in terms of efficiency and outcomes. Societal concerns in relation to quality assurance, patient safety and cost reduction have highlighted the issue of training expert surgeons. The core elements of a training model build on the basic foundations of gross and fine motor skills. In this paper we provide an analysis of the ergonomic principles involved and propose relevant training techniques. We have endeavored to provide both the trainer and trainee perspectives. This paper is structured into four sections: 1) Pre-operative preparation issues, 2) technical skills and instrument handling, 3) low fidelity simulation models and 4) discussion of current concepts in crew resource management, deliberate practice and assessment. Rehearsal, warm-up and motivation-enhancing techniques aid concentration and focus. Appropriate posture, comprehension of ergonomic principles in relation to surgical instruments and utilisation of the non-dominant hand are essential skills to master. Low fidelity models can be used to achieve significant progress through the early stages of the learning curve. Deliberate practice and innate ability are complementary to each other and may be considered useful adjuncts to surgical skills development. Safe medical care requires that complex patient interventions be performed by highly skilled operators supported by reliable teams. Surgical ergonomics lie at the heart of any training model that aims to produce professionals able to function as leaders of a patient safety oriented culture. Copyright © 2015 IJS Publishing Group Limited. Published by Elsevier Ltd. All rights reserved.

Using Mason number to predict MR damper performance from limited test data

NASA Astrophysics Data System (ADS)

Becnel, Andrew C.; Wereley, Norman M.

2017-05-01

The Mason number can be used to produce a single master curve which relates MR fluid stress versus strain rate behavior across a wide range of shear rates, temperatures, and applied magnetic fields. As applications of MR fluid energy absorbers expand to a variety of industries and operating environments, Mason number analysis offers a path to designing devices with desired performance from a minimal set of preliminary test data. Temperature strongly affects the off-state viscosity of the fluid, as the passive viscous force drops considerably at higher temperatures. Yield stress is not similarly affected, and stays relatively constant with changing temperature. In this study, a small model-scale MR fluid rotary energy absorber is used to measure the temperature correction factor of a commercially-available MR fluid from LORD Corporation. This temperature correction factor is identified from shear stress vs. shear rate data collected at four different temperatures. Measurements of the MR fluid yield stress are also obtained and related to a standard empirical formula. From these two MR fluid properties - temperature-dependent viscosity and yield stress - the temperature-corrected Mason number is shown to predict the force vs. velocity performance of a full-scale rotary MR fluid energy absorber. This analysis technique expands the design space of MR devices to high shear rates and allows for comprehensive predictions of overall performance across a wide range of operating conditions from knowledge only of the yield stress vs. applied magnetic field and a temperature-dependent viscosity correction factor.

ADVANCED INTEGRATION OF MULTI-SCALE MECHANICS AND WELDING PROCESS SIMULATION IN WELD INTEGRITY ASSESSMENT

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

Wilkowski, Gery M.; Rudland, David L.; Shim, Do-Jun

2008-06-30

The potential to save trillions of BTU’s in energy usage and billions of dollars in cost on an annual basis based on use of higher strength steel in major oil and gas transmission pipeline construction is a compelling opportunity recognized by both the US Department of Energy (DOE). The use of high-strength steels (X100) is expected to result in energy savings across the spectrum, from manufacturing the pipe to transportation and fabrication, including welding of line pipe. Elementary examples of energy savings include more the 25 trillion BTUs saved annually based on lower energy costs to produce the thinner-walled high-strengthmore » steel pipe, with the potential for the US part of the Alaskan pipeline alone saving more than 7 trillion BTU in production and much more in transportation and assembling. Annual production, maintenance and installation of just US domestic transmission pipeline is likely to save 5 to 10 times this amount based on current planned and anticipated expansions of oil and gas lines in North America. Among the most important conclusions from these studies were: • While computational weld models to predict residual stress and distortions are well-established and accurate, related microstructure models need improvement. • Fracture Initiation Transition Temperature (FITT) Master Curve properly predicts surface-cracked pipe brittle-to-ductile initiation temperature. It has value in developing Codes and Standards to better correlate full-scale behavior from either CTOD or Charpy test results with the proper temperature shifts from the FITT master curve method. • For stress-based flaw evaluation criteria, the new circumferentially cracked pipe limit-load solution in the 2007 API 1104 Appendix A approach is overly conservative by a factor of 4/π, which has additional implications. . • For strain-based design of girth weld defects, the hoop stress effect is the most significant parameter impacting CTOD-driving force and can increase the crack-driving force by a factor of 2 depending on strain-hardening, pressure level as a % of SMYS, and flaw size. • From years of experience in circumferential fracture analyses and experimentation, there has not been sufficient integration of work performed for other industries into analogous problems facing the oil and gas pipeline markets. Some very basic concepts and problems solved previously in these fields could have circumvented inconsistencies seen in the stress-based and strain-based analysis efforts. For example, in nuclear utility piping work, more detailed elastic-plastic fracture analyses were always validated in their ability to predict loads and displacements (stresses and strains). The eventual implementation of these methodologies will result in acceleration of the industry adoption of higher-strength line-pipe steels.« less

Dynamics of snapping beams and jumping poppers

NASA Astrophysics Data System (ADS)

Pandey, A.; Moulton, D. E.; Vella, D.; Holmes, D. P.

2014-01-01

We consider the dynamic snapping instability of elastic beams and shells. Using the Kirchhoff rod and Föppl-von Kármán plate equations, we study the stability, deformation modes, and snap-through dynamics of an elastic arch with clamped boundaries and subject to a concentrated load. For parameters typical of everyday and technological applications of snapping, we show that the stretchability of the arch plays a critical role in determining not only the post-buckling mode of deformation but also the timescale of snapping and the frequency of the arch's vibrations about its final equilibrium state. We show that the growth rate of the snap-through instability and its subsequent ringing frequency can both be interpreted physically as the result of a sound wave in the material propagating over a distance comparable to the length of the arch. Finally, we extend our analysis of the ringing frequency of indented arches to understand the “pop” heard when everted shell structures snap-through to their stable state. Remarkably, we find that not only are the scaling laws for the ringing frequencies in these two scenarios identical but also the respective prefactors are numerically close; this allows us to develop a master curve for the frequency of ringing in snapping beams and shells.

On the phenomenon of curved microcracks in /(S)/90n/s laminates - Their shapes, initiation angles and locations

NASA Technical Reports Server (NTRS)

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

1993-01-01

A variational analysis of the stress state in microcracked cross-ply laminates has been used to investigate the phenomenon of curved microcracking in /(S)/90n/s laminates. Previous investigators proposed that the initiation and orientation of curved microcracks are controlled by local maxima and stress trajectories of the principal stresses. We have implemented a principal stress model using a variational mechanics stress analysis and we were able to make predictions about curved microcracks. The predictions agree well with experimental observations and therefore support the assertion that the variational analysis gives an accurate stress state that is useful for modeling the microcracking properties of cross-ply laminates. An important prediction about curved microcracks is that they are a late stage of microcracking damage. They occur only when the crack density of straight microcracks exceeds the critical crack density for curved microcracking. The predicted critical crack density for curved microcracking agrees well with experimental observations.

Kathleen Krah | NREL

Science.gov Websites

tool validation. Previous to joining NREL, her Masters thesis focused on a spatial analysis of strategies. Her undergraduate thesis focused on techno-economic and logistical cost modeling of offshore wind

MONROE COMMUNITY COLLEGE CAMPUS PLAN.

ERIC Educational Resources Information Center

Caudill, Rowlett, Scott and Associates, Bryan, TX.

THE MASTER PLANS FOR THE CONSTRUCTION OF THE CAMPUS OF THE NEW MONROE COMMUNITY COLLEGE INCLUDE EDUCATIONAL SPECIFICATIONS, SITE ANALYSIS DATA AND BUILDING PLANS. THE EDUCATIONAL SPECIFICATIONS ARE BASED UPON COMMUNITY NEEDS AND ENROLLMENT PROJECTIONS, AND REFLECT SPACE REQUIREMENTS. IN THE SITE ANALYSIS, FACTORS SUCH AS TOPOGRAPHY, CLIMATE,…

Optimization of Capillary Electrophoresis With Laser Induced Fluorescent (CE-LIF) Detection for the Analysis of Double Standed DNA Polymerase Chain Reaction Products from the Telomeric Repeat Amplification Protocol

DTIC Science & Technology

2000-12-06

Fluorescent Milligram (10ŗ) Milliliter (10ŗ) vm ^g Microgram (10") 1*1 Microliter (10" 6) MMA Master Mix A MMB Master Mix B NSCLC Non-Small-Cell...little effect on heat dissipation, the mixing helped to smooth out the convection gradients (see Weinberger 1993). The use of smaller i.d...clogging may occur (Heller 1998a). The gels must be covalently bound to the capillary wall to avoid extrusion from the capillary by electroosmotic flow

Sexual imagery in cigarette advertising before and after the master settlement agreement.

PubMed

Baek, Tae Hyun; Mayer, Mark

2010-12-01

This study examines how the sexual imagery in cigarette magazine advertisements changed as a result of the 1998 Master Settlement Agreement (MSA). After conducting a content analysis of 657 unduplicated cigarette ads from 1994 to 2003, our results revealed that cigarette advertisements featuring suggestive/partially clad female models increased significantly from the pre-MSA period (16.0%) to the post-MSA period (24.9%). In addition, we provide empirical evidence that there was an overall increase in sexually explicit cigarette advertising after the MSA. Several implications for policymakers are discussed in detail.

[Research in the Master's Degree program in Social Medicine].

PubMed

Laurell, C; Mercer, H

1981-01-01

The authors report on research as part of the master's degree in social medicine at the Metropolitan Autonomous University, Xochimilco campus, Mexico. They discuss research within the curriculum design, instructional research, teaching staff and research, and research as a source of knowledge. They explain that in order to establish guidelines for research it is necessary to consider the health-disease process and medical practice within the economic and social framework and therefore subject to analysis by the social sciences. Finally, they summarize ongoing research in the fields of social epidemiology, medical practice and planning, and human resources.

Indoor Soiling Method and Outdoor Statistical Risk Analysis of Photovoltaic Power Plants

NASA Astrophysics Data System (ADS)

Rajasekar, Vidyashree

This is a two-part thesis. Part 1 presents an approach for working towards the development of a standardized artificial soiling method for laminated photovoltaic (PV) cells or mini-modules. Construction of an artificial chamber to maintain controlled environmental conditions and components/chemicals used in artificial soil formulation is briefly explained. Both poly-Si mini-modules and a single cell mono-Si coupons were soiled and characterization tests such as I-V, reflectance and quantum efficiency (QE) were carried out on both soiled, and cleaned coupons. From the results obtained, poly-Si mini-modules proved to be a good measure of soil uniformity, as any non-uniformity present would not result in a smooth curve during I-V measurements. The challenges faced while executing reflectance and QE characterization tests on poly-Si due to smaller size cells was eliminated on the mono-Si coupons with large cells to obtain highly repeatable measurements. This study indicates that the reflectance measurements between 600-700 nm wavelengths can be used as a direct measure of soil density on the modules. Part 2 determines the most dominant failure modes of field aged PV modules using experimental data obtained in the field and statistical analysis, FMECA (Failure Mode, Effect, and Criticality Analysis). The failure and degradation modes of about 744 poly-Si glass/polymer frameless modules fielded for 18 years under the cold-dry climate of New York was evaluated. Defect chart, degradation rates (both string and module levels) and safety map were generated using the field measured data. A statistical reliability tool, FMECA that uses Risk Priority Number (RPN) is used to determine the dominant failure or degradation modes in the strings and modules by means of ranking and prioritizing the modes. This study on PV power plants considers all the failure and degradation modes from both safety and performance perspectives. The indoor and outdoor soiling studies were jointly performed by two Masters Students, Sravanthi Boppana and Vidyashree Rajasekar. This thesis presents the indoor soiling study, whereas the other thesis presents the outdoor soiling study. Similarly, the statistical risk analyses of two power plants (model J and model JVA) were jointly performed by these two Masters students. Both power plants are located at the same cold-dry climate, but one power plant carries framed modules and the other carries frameless modules. This thesis presents the results obtained on the frameless modules.

The Implication of Using NVivo Software in Qualitative Data Analysis: Evidence-Based Reflections.

PubMed

Zamawe, F C

2015-03-01

For a long time, electronic data analysis has been associated with quantitative methods. However, Computer Assisted Qualitative Data Analysis Software (CAQDAS) are increasingly being developed. Although the CAQDAS has been there for decades, very few qualitative health researchers report using it. This may be due to the difficulties that one has to go through to master the software and the misconceptions that are associated with using CAQDAS. While the issue of mastering CAQDAS has received ample attention, little has been done to address the misconceptions associated with CAQDAS. In this paper, the author reflects on his experience of interacting with one of the popular CAQDAS (NVivo) in order to provide evidence-based implications of using the software. The key message is that unlike statistical software, the main function of CAQDAS is not to analyse data but rather to aid the analysis process, which the researcher must always remain in control of. In other words, researchers must equally know that no software can analyse qualitative data. CAQDAS are basically data management packages, which support the researcher during analysis.

A Comparative Analysis of PISA Scientific Literacy Framework in Finnish and Thai Science Curricula

ERIC Educational Resources Information Center

Sothayapetch, Pavinee; Lavonen, Jari; Juuti, Kalle

2013-01-01

A curriculum is a master plan that regulates teaching and learning. This paper compares Finnish and Thai primary school level science curricula to the PISA 2006 Scientific Literacy Framework. Curriculum comparison was made following the procedure of deductive content analysis. In the analysis, there were four main categories adopted from PISA…

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.

48 CFR 217.7103-6 - Modification of master agreements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 48 Federal Acquisition Regulations System 3 2013-10-01 2013-10-01 false Modification of master... Master Agreement for Repair and Alteration of Vessels 217.7103-6 Modification of master agreements. (a) Review each master agreement at least annually before the anniversary of its effective date and revise it...

46 CFR 189.35-13 - Master's responsibility.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 7 2012-10-01 2012-10-01 false Master's responsibility. 189.35-13 Section 189.35-13... AND CERTIFICATION Weight Handling Gear § 189.35-13 Master's responsibility. (a) The master of the... permitted to operate the weight handling gear. The master shall designate the operators. (5) A minimum...

46 CFR Sec. 3 - Master's requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 8 2010-10-01 2010-10-01 false Master's requirements. Sec. 3 Section 3 Shipping... Master's requirements. The Master shall: (a) Receive and receipt for the quantities of slop chest items... therefor, at the unit price, specified by the Slop Chest Statement furnished the Master by the General...

48 CFR 217.7103-6 - Modification of master agreements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Modification of master... Master Agreement for Repair and Alteration of Vessels 217.7103-6 Modification of master agreements. (a) Review each master agreement at least annually before the anniversary of its effective date and revise it...

46 CFR 189.35-13 - Master's responsibility.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 7 2014-10-01 2014-10-01 false Master's responsibility. 189.35-13 Section 189.35-13... AND CERTIFICATION Weight Handling Gear § 189.35-13 Master's responsibility. (a) The master of the... permitted to operate the weight handling gear. The master shall designate the operators. (5) A minimum...

48 CFR 217.7103-1 - Content and format of master agreements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... master agreements. 217.7103-1 Section 217.7103-1 Federal Acquisition Regulations System DEFENSE... CONTRACTING METHODS Master Agreement for Repair and Alteration of Vessels 217.7103-1 Content and format of master agreements. Follow the procedures at PGI 217.7103-1 for preparation of master agreements. [71 FR...

48 CFR 217.7103-6 - Modification of master agreements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Modification of master... Master Agreement for Repair and Alteration of Vessels 217.7103-6 Modification of master agreements. (a) Review each master agreement at least annually before the anniversary of its effective date and revise it...

48 CFR 217.7103-1 - Content and format of master agreements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... master agreements. 217.7103-1 Section 217.7103-1 Federal Acquisition Regulations System DEFENSE... CONTRACTING METHODS Master Agreement for Repair and Alteration of Vessels 217.7103-1 Content and format of master agreements. Follow the procedures at PGI 217.7103-1 for preparation of master agreements. [71 FR...

48 CFR 217.7103-1 - Content and format of master agreements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... master agreements. 217.7103-1 Section 217.7103-1 Federal Acquisition Regulations System DEFENSE... CONTRACTING METHODS Master Agreement for Repair and Alteration of Vessels 217.7103-1 Content and format of master agreements. Follow the procedures at PGI 217.7103-1 for preparation of master agreements. [71 FR...

46 CFR Sec. 3 - Master's requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 8 2011-10-01 2011-10-01 false Master's requirements. Sec. 3 Section 3 Shipping... Master's requirements. The Master shall: (a) Receive and receipt for the quantities of slop chest items... therefor, at the unit price, specified by the Slop Chest Statement furnished the Master by the General...

46 CFR Sec. 3 - Master's requirements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 8 2012-10-01 2012-10-01 false Master's requirements. Sec. 3 Section 3 Shipping... Master's requirements. The Master shall: (a) Receive and receipt for the quantities of slop chest items... therefor, at the unit price, specified by the Slop Chest Statement furnished the Master by the General...

46 CFR Sec. 3 - Master's requirements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 8 2014-10-01 2014-10-01 false Master's requirements. Sec. 3 Section 3 Shipping... Master's requirements. The Master shall: (a) Receive and receipt for the quantities of slop chest items... therefor, at the unit price, specified by the Slop Chest Statement furnished the Master by the General...

46 CFR Sec. 3 - Master's requirements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 8 2013-10-01 2013-10-01 false Master's requirements. Sec. 3 Section 3 Shipping... Master's requirements. The Master shall: (a) Receive and receipt for the quantities of slop chest items... therefor, at the unit price, specified by the Slop Chest Statement furnished the Master by the General...

46 CFR 189.35-13 - Master's responsibility.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 7 2011-10-01 2011-10-01 false Master's responsibility. 189.35-13 Section 189.35-13... AND CERTIFICATION Weight Handling Gear § 189.35-13 Master's responsibility. (a) The master of the... permitted to operate the weight handling gear. The master shall designate the operators. (5) A minimum...

46 CFR 189.35-13 - Master's responsibility.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 7 2013-10-01 2013-10-01 false Master's responsibility. 189.35-13 Section 189.35-13... AND CERTIFICATION Weight Handling Gear § 189.35-13 Master's responsibility. (a) The master of the... permitted to operate the weight handling gear. The master shall designate the operators. (5) A minimum...

48 CFR 217.7103-1 - Content and format of master agreements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... master agreements. 217.7103-1 Section 217.7103-1 Federal Acquisition Regulations System DEFENSE... CONTRACTING METHODS Master Agreement for Repair and Alteration of Vessels 217.7103-1 Content and format of master agreements. Follow the procedures at PGI 217.7103-1 for preparation of master agreements. [71 FR...

48 CFR 217.7103-1 - Content and format of master agreements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... master agreements. 217.7103-1 Section 217.7103-1 Federal Acquisition Regulations System DEFENSE... CONTRACTING METHODS Master Agreement for Repair and Alteration of Vessels 217.7103-1 Content and format of master agreements. Follow the procedures at PGI 217.7103-1 for preparation of master agreements. [71 FR...

48 CFR 217.7103-6 - Modification of master agreements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 48 Federal Acquisition Regulations System 3 2012-10-01 2012-10-01 false Modification of master... Master Agreement for Repair and Alteration of Vessels 217.7103-6 Modification of master agreements. (a) Review each master agreement at least annually before the anniversary of its effective date and revise it...

48 CFR 217.7103-6 - Modification of master agreements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 3 2014-10-01 2014-10-01 false Modification of master... Master Agreement for Repair and Alteration of Vessels 217.7103-6 Modification of master agreements. (a) Review each master agreement at least annually before the anniversary of its effective date and revise it...

78 FR 43251 - Grosvenor Alternative Funds Master Trust, et al.; Notice of Application

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-19

... Alternative Funds Master Trust, et al.; Notice of Application July 15, 2013. AGENCY: Securities and Exchange... Alternative Funds Master Trust (``Master Trust''), Grosvenor Alternative Funds (``GAF Trust''), and Grosvenor... calling (202) 551-8090. Applicants' Representations 1. The Master Trust \\1\\ and the GAF Trust...

A qualitative inquiry into the development and facilitation of a science education learning community through participation in an online graduate program

NASA Astrophysics Data System (ADS)

Callihan, Laurie Ann Perryman

This study is a qualitative inquiry considering the development and facilitation of a science education community of practice according to the definition of Wenger (1998, 1999) through participation in the graduate online science education program (GOSEP) Master's Degree track. Three research questions were considered: (1) In what ways do interactions within the GOSEP community of practice impact development of the teacher/student from outsider to novice to apprentice to master (Wenger, 1999)? (2) In what ways does personal development impact the community of practice? (3) In what ways do the interactions of professors with students impact the development of a community of practice in the GOSEP? The qualitative research frame was Integral Methodological Pluralism along with a hermeneutical approach to textual analysis and an autoethnographic viewpoint. The participants included seven students and two professors from the GOSEP. Data analyzed was in situ Blackboard(TM) and other online venues from classes dating Fall 2007 through Summer 2009 as well as semi-structured interviews, follow-ups, and member-check surveys. Results supported the assertions that (1) a community of practice (CoP) existed in the GOSEP, (2) the CoP assisted individual learning and growth from apprentice to novice to master, (3) that the CoP was most healthy and supported apprentice to master growth when a diversity of adult developmental levels existed in the group, and (4) the interactions of the professors in allowing the students to take on master roles and limiting their own control within the CoP contributed to the healthy development of students from apprentice to novice to master. Implications of this research suggest that the CoP model of online learning is effective and productive in allowing students to gain experience and knowledge in the skills, background knowledge, theory, and practice of becoming masters in the practice for which the community is designed to study. Future research engaging online CoPs with greater numbers, longer periods of study, and comparative studies with other types of online programs is suggested.

An online survey of chiropractors' opinions of continuing education

PubMed Central

Stuber, Kent J; Grod, Jaroslaw P; Smith, Dean L; Powers, Paul

2005-01-01

Background Continuing Education (CE) for chiropractors is mandatory for licensure in most North American jurisdictions. Numerous chiropractic colleges have begun collaborating with universities to offer master's degree programs. Distance education master's degree programs may be desirable to allow full-time practicing doctors to further their post-graduate education. The present survey sought to answer three questions. First, what is the level of satisfaction of chiropractors with their continuing education? Second, what is the level of interest of chiropractors in online master's degree programs? Lastly, what is the response rate of chiropractors to an online survey? Methods An online survey consisting of 22 multiple choice questions was e-mailed to 1000 chiropractors randomly selected from the mailing list of an online chiropractic newsletter. Upon completion of the questionnaire, participants' answers were saved on a secure site. Data analysis included evaluation of the demographic characteristics of the respondents, their opinions of and patterns of taking CE including online education, preferred learning formats, and their interest in proposed online master's degree programs. A survey response rate was determined. Results Nearly 86% of respondents felt their previously completed CE courses were either somewhat or extremely satisfactory. Over ninety percent of respondents who had completed online or distance CE coursesfound them to be somewhat or extremelysatisfactory. Almost half the respondents indicated that they most preferred online distance learning, while 34.08% most preferred face-to-face interaction. Fifty-three percent of respondents indicated an interest in starting a master's degree program; however 70.46% of respondents were interested in an online master's degree program that would offer CE credit. A response rate of 35.8% was obtained. Conclusion Satisfaction among chiropractors with CE programs is high. The notion of completing a part-time online master's degree (or online combined with face-to-face interaction) appears to be popular among respondents, with a M.Sc. in Chiropractic Sciences being the most popular of those mentioned. Online surveys are a viable method of obtaining opinion in a cost and time efficient manner; there are some sources of bias involved in this type of research, and numerous steps need to be taken to obtain a suitable response rate. PMID:16242035

pROC: an open-source package for R and S+ to analyze and compare ROC curves.

PubMed

Robin, Xavier; Turck, Natacha; Hainard, Alexandre; Tiberti, Natalia; Lisacek, Frédérique; Sanchez, Jean-Charles; Müller, Markus

2011-03-17

Receiver operating characteristic (ROC) curves are useful tools to evaluate classifiers in biomedical and bioinformatics applications. However, conclusions are often reached through inconsistent use or insufficient statistical analysis. To support researchers in their ROC curves analysis we developed pROC, a package for R and S+ that contains a set of tools displaying, analyzing, smoothing and comparing ROC curves in a user-friendly, object-oriented and flexible interface. With data previously imported into the R or S+ environment, the pROC package builds ROC curves and includes functions for computing confidence intervals, statistical tests for comparing total or partial area under the curve or the operating points of different classifiers, and methods for smoothing ROC curves. Intermediary and final results are visualised in user-friendly interfaces. A case study based on published clinical and biomarker data shows how to perform a typical ROC analysis with pROC. pROC is a package for R and S+ specifically dedicated to ROC analysis. It proposes multiple statistical tests to compare ROC curves, and in particular partial areas under the curve, allowing proper ROC interpretation. pROC is available in two versions: in the R programming language or with a graphical user interface in the S+ statistical software. It is accessible at http://expasy.org/tools/pROC/ under the GNU General Public License. It is also distributed through the CRAN and CSAN public repositories, facilitating its installation.

Final Environmental Assessment for Camp Rudder Master Plan at Eglin Air Force Base, FL

DTIC Science & Technology

2005-06-07

warranting detailed analysis. Hazardous Materials The 6th RTB currently generates hazardous materials in the form of weapons cleaning products and...wastes. There would be no increase in the use of weapons cleaning products ; and therefore, this area does not require analysis. Additionally

The Financial Resilience of Independent Colleges and Universities

ERIC Educational Resources Information Center

Chessman, Hollie M.; Hartley, Harold V., III; Williams, Michael

2017-01-01

This report explores the financial resilience of independent colleges and universities through an analysis of 14 years (fiscal years 2001-2014) of financial data from 559 private nondoctoral institutions. Through analysis of financial performance in several domains, the data reveal that the majority of independent baccalaureate and master's-level…

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

Meta-Analysis: An Approach to Interview Success.

ERIC Educational Resources Information Center

McCaslin, Mark; Carlson, Nancy M.

An initial research step, developing an effective interview strategy, presents unique challenges for novice and master research alike. To focus qualitative research in the human ecology of the study, the strategy presented in this paper used an initial interview protocol and preanalysis process, called meta-analysis, prior to developing the formal…

Writing Characteristics of Students with Attention Deficit Hyperactive Disorder: A Meta-Analysis

ERIC Educational Resources Information Center

Graham, Steve; Fishman, Evan J.; Reid, Robert; Hebert, Michael

2016-01-01

Students with Attention Deficit Hyperactivity Disorders (ADHD) frequently experience significant difficulty mastering basic academic skills. This meta-analysis focuses on one specific potential area of learning difficulties for these students: namely, writing. To identify the extent and depth of the potential writing challenges faced by students…

Computer-Generated, Three-Dimensional Character Animation: A Report and Analysis.

ERIC Educational Resources Information Center

Kingsbury, Douglas Lee

This master's thesis details the experience gathered in the production "Snoot and Muttly," a short character animation with 3-D computer generated images, and provides an analysis of the computer-generated 3-D character animation system capabilities. Descriptions are provided of the animation environment at the Ohio State University…

Cloning SU8 silicon masters using epoxy resins to increase feature replicability and production for cell culture devices.

PubMed

Kamande, J W; Wang, Y; Taylor, A M

2015-05-01

In recent years, there has been a dramatic increase in the use of poly(dimethylsiloxane) (PDMS) devices for cell-based studies. Commonly, the negative tone photoresist, SU8, is used to pattern features onto silicon wafers to create masters (SU8-Si) for PDMS replica molding. However, the complexity in the fabrication process, low feature reproducibility (master-to-master variability), silane toxicity, and short life span of these masters have been deterrents for using SU8-Si masters for the production of cell culture based PDMS microfluidic devices. While other techniques have demonstrated the ability to generate multiple devices from a single master, they often do not match the high feature resolution (∼0.1 μm) and low surface roughness that soft lithography masters offer. In this work, we developed a method to fabricate epoxy-based masters that allows for the replication of features with high fidelity directly from SU8-Si masters via their PDMS replicas. By this method, we show that we could obtain many epoxy based masters with equivalent features to a single SU8-Si master with a low feature variance of 1.54%. Favorable feature transfer resolutions were also obtained by using an appropriate Tg epoxy based system to ensure minimal shrinkage of features ranging in size from ∼100 μm to <10 μm in height. We further show that surface coating epoxy masters with Cr/Au lead to effective demolding and yield PDMS chambers that are suitable for long-term culturing of sensitive primary hippocampal neurons. Finally, we incorporated pillars within the Au-epoxy masters to eliminate the process of punching media reservoirs and thereby reducing substantial artefacts and wastage.

Cloning SU8 silicon masters using epoxy resins to increase feature replicability and production for cell culture devices

PubMed Central

Kamande, J. W.; Wang, Y.; Taylor, A. M.

2015-01-01

In recent years, there has been a dramatic increase in the use of poly(dimethylsiloxane) (PDMS) devices for cell-based studies. Commonly, the negative tone photoresist, SU8, is used to pattern features onto silicon wafers to create masters (SU8-Si) for PDMS replica molding. However, the complexity in the fabrication process, low feature reproducibility (master-to-master variability), silane toxicity, and short life span of these masters have been deterrents for using SU8-Si masters for the production of cell culture based PDMS microfluidic devices. While other techniques have demonstrated the ability to generate multiple devices from a single master, they often do not match the high feature resolution (∼0.1 μm) and low surface roughness that soft lithography masters offer. In this work, we developed a method to fabricate epoxy-based masters that allows for the replication of features with high fidelity directly from SU8-Si masters via their PDMS replicas. By this method, we show that we could obtain many epoxy based masters with equivalent features to a single SU8-Si master with a low feature variance of 1.54%. Favorable feature transfer resolutions were also obtained by using an appropriate Tg epoxy based system to ensure minimal shrinkage of features ranging in size from ∼100 μm to <10 μm in height. We further show that surface coating epoxy masters with Cr/Au lead to effective demolding and yield PDMS chambers that are suitable for long-term culturing of sensitive primary hippocampal neurons. Finally, we incorporated pillars within the Au-epoxy masters to eliminate the process of punching media reservoirs and thereby reducing substantial artefacts and wastage. PMID:26180572

Dual arm master controller for a bilateral servo-manipulator

DOEpatents

Kuban, Daniel P.; Perkins, Gerald S.

1989-01-01

A master controller for a mechanically dissimilar bilateral slave servo-manipulator is disclosed. The master controller includes a plurality of drive trains comprising a plurality of sheave arrangements and cables for controlling upper and lower degrees of master movement. The cables and sheaves of the master controller are arranged to effect kinematic duplication of the slave servo-manipulator, despite mechanical differences therebetween. A method for kinematically matching a master controller to a slave servo-manipulator is also disclosed.

A polymeric master replication technology for mass fabrication of poly(dimethylsiloxane) microfluidic devices.

PubMed

Li, Hai-Fang; Lin, Jin-Ming; Su, Rong-Guo; Cai, Zong Wei; Uchiyama, Katsumi

2005-05-01

A protocol of producing multiple polymeric masters from an original glass master mold has been developed, which enables the production of multiple poly(dimethylsiloxane) (PDMS)-based microfluidic devices in a low-cost and efficient manner. Standard wet-etching techniques were used to fabricate an original glass master with negative features, from which more than 50 polymethylmethacrylate (PMMA) positive replica masters were rapidly created using the thermal printing technique. The time to replicate each PMMA master was as short as 20 min. The PMMA replica masters have excellent structural features and could be used to cast PDMS devices for many times. An integration geometry designed for laser-induced fluorescence (LIF) detection, which contains normal deep microfluidic channels and a much deeper optical fiber channel, was successfully transferred into PDMS devices. The positive relief on seven PMMA replica masters is replicated with regard to the negative original glass master, with a depth average variation of 0.89% for 26-microm deep microfluidic channels and 1.16% for the 90 mum deep fiber channel. The imprinted positive relief in PMMA from master-to-master is reproducible with relative standard deviations (RSDs) of 1.06% for the maximum width and 0.46% for depth in terms of the separation channel. The PDMS devices fabricated from the PMMA replica masters were characterized and applied to the separation of a fluorescein isothiocyanate (FITC)-labeled epinephrine sample.

The Master Artisan: A Framework for Master Tradespeople in Australia. Occasional Paper

ERIC Educational Resources Information Center

O'Reilly-Briggs, Karen

2011-01-01

The author explores the prospect of improving pathways and opportunities for tradespeople in Australia through the introduction of a masters-level qualification. The study investigates the views and opinions of senior industry representatives and professional educators to determine whether the introduction of a master trade or master artisan…

19 CFR 10.90 - Master records and metal matrices.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 19 Customs Duties 1 2011-04-01 2011-04-01 false Master records and metal matrices. 10.90 Section... Master Records, and Metal Matrices § 10.90 Master records and metal matrices. (a) Consumption entries... made, of each master record or metal matrix covered thereby. (c) A bond on Customs Form 301, containing...

19 CFR 10.90 - Master records and metal matrices.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 19 Customs Duties 1 2013-04-01 2013-04-01 false Master records and metal matrices. 10.90 Section... Master Records, and Metal Matrices § 10.90 Master records and metal matrices. (a) Consumption entries... made, of each master record or metal matrix covered thereby. (c) A bond on Customs Form 301, containing...

20 CFR 632.22 - Modification of a Comprehensive Annual Plan (CAP) and/or Master Plan.

Code of Federal Regulations, 2012 CFR

2012-04-01

... (CAP) and/or Master Plan. 632.22 Section 632.22 Employees' Benefits EMPLOYMENT AND TRAINING... Master Plan. (a) The requirements for modifying a Master Plan and/or CAP will be included in administrative instructions issued by the Grant Officer upon final implementation of the Master Plan/CAP system...

21 CFR 111.210 - What must the master manufacturing record include?

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 2 2011-04-01 2011-04-01 false What must the master manufacturing record include...: Requirements for the Master Manufacturing Record § 111.210 What must the master manufacturing record include? The master manufacturing record must include: (a) The name of the dietary supplement to be...

21 CFR 111.210 - What must the master manufacturing record include?

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 2 2012-04-01 2012-04-01 false What must the master manufacturing record include...: Requirements for the Master Manufacturing Record § 111.210 What must the master manufacturing record include? The master manufacturing record must include: (a) The name of the dietary supplement to be...

21 CFR 111.210 - What must the master manufacturing record include?

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 2 2014-04-01 2014-04-01 false What must the master manufacturing record include...: Requirements for the Master Manufacturing Record § 111.210 What must the master manufacturing record include? The master manufacturing record must include: (a) The name of the dietary supplement to be...

19 CFR 10.90 - Master records and metal matrices.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 19 Customs Duties 1 2014-04-01 2014-04-01 false Master records and metal matrices. 10.90 Section... Master Records, and Metal Matrices § 10.90 Master records and metal matrices. (a) Consumption entries... made, of each master record or metal matrix covered thereby. (c) A bond on Customs Form 301, containing...

16 CFR 1011.4 - Forms of advance public notice of meetings; Public Calendar/Master Calendar and Federal Register.

Code of Federal Regulations, 2012 CFR

2012-01-01

...; Public Calendar/Master Calendar and Federal Register. 1011.4 Section 1011.4 Commercial Practices CONSUMER... meetings; Public Calendar/Master Calendar and Federal Register. Advance notice of Agency activities is... Calendar/Master Calendar. (1) The printed Public Calendar and the Master Calendar maintained in the Office...

19 CFR 10.90 - Master records and metal matrices.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 19 Customs Duties 1 2012-04-01 2012-04-01 false Master records and metal matrices. 10.90 Section... Master Records, and Metal Matrices § 10.90 Master records and metal matrices. (a) Consumption entries... made, of each master record or metal matrix covered thereby. (c) A bond on Customs Form 301, containing...

16 CFR 1011.4 - Forms of advance public notice of meetings; Public Calendar/Master Calendar and Federal Register.

Code of Federal Regulations, 2014 CFR

2014-01-01

...; Public Calendar/Master Calendar and Federal Register. 1011.4 Section 1011.4 Commercial Practices CONSUMER... meetings; Public Calendar/Master Calendar and Federal Register. Advance notice of Agency activities is... Calendar/Master Calendar. (1) The printed Public Calendar and the Master Calendar maintained in the Office...

21 CFR 111.210 - What must the master manufacturing record include?

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 2 2013-04-01 2013-04-01 false What must the master manufacturing record include...: Requirements for the Master Manufacturing Record § 111.210 What must the master manufacturing record include? The master manufacturing record must include: (a) The name of the dietary supplement to be...

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…

20 CFR 632.22 - Modification of a Comprehensive Annual Plan (CAP) and/or Master Plan.

Code of Federal Regulations, 2011 CFR

2011-04-01

... (CAP) and/or Master Plan. 632.22 Section 632.22 Employees' Benefits EMPLOYMENT AND TRAINING... Master Plan. (a) The requirements for modifying a Master Plan and/or CAP will be included in administrative instructions issued by the Grant Officer upon final implementation of the Master Plan/CAP system...

Science Professionals: Master's Education for a Competitive World

ERIC Educational Resources Information Center

National Academies Press, 2008

2008-01-01

What are employer needs for staff trained in the natural sciences at the master's degree level? How do master's level professionals in the natural sciences contribute in the workplace? How do master's programs meet or support educational and career goals? "Science Professionals: Master's Education for a Competitive World" examines the answers to…

Experiential Learning: Lessons Learned from the UND Business and Government Symposium

ERIC Educational Resources Information Center

Harsell, Dana Michael; O'Neill, Patrick B.

2010-01-01

The authors describe lessons learned from a limited-duration experiential learning component of a Master's level course. The course is open to Master's in Business and Master's in Public Administration students and explores the relationships between government and business. A complete discussion of the Master's in Business and Master's in Public…

19 CFR 10.90 - Master records and metal matrices.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 19 Customs Duties 1 2010-04-01 2010-04-01 false Master records and metal matrices. 10.90 Section... Master Records, and Metal Matrices § 10.90 Master records and metal matrices. (a) Consumption entries... made, of each master record or metal matrix covered thereby. (c) A bond on Customs Form 301, containing...

Application of computer-aided diagnosis (CAD) in MR-mammography (MRM): do we really need whole lesion time curve distribution analysis?

PubMed

Baltzer, Pascal Andreas Thomas; Renz, Diane M; Kullnig, Petra E; Gajda, Mieczyslaw; Camara, Oumar; Kaiser, Werner A

2009-04-01

The identification of the most suspect enhancing part of a lesion is regarded as a major diagnostic criterion in dynamic magnetic resonance mammography. Computer-aided diagnosis (CAD) software allows the semi-automatic analysis of the kinetic characteristics of complete enhancing lesions, providing additional information about lesion vasculature. The diagnostic value of this information has not yet been quantified. Consecutive patients from routine diagnostic studies (1.5 T, 0.1 mmol gadopentetate dimeglumine, dynamic gradient-echo sequences at 1-minute intervals) were analyzed prospectively using CAD. Dynamic sequences were processed and reduced to a parametric map. Curve types were classified by initial signal increase (not significant, intermediate, and strong) and the delayed time course of signal intensity (continuous, plateau, and washout). Lesion enhancement was measured using CAD. The most suspect curve, the curve-type distribution percentage, and combined dynamic data were compared. Statistical analysis included logistic regression analysis and receiver-operating characteristic analysis. Fifty-one patients with 46 malignant and 44 benign lesions were enrolled. On receiver-operating characteristic analysis, the most suspect curve showed diagnostic accuracy of 76.7 +/- 5%. In comparison, the curve-type distribution percentage demonstrated accuracy of 80.2 +/- 4.9%. Combined dynamic data had the highest diagnostic accuracy (84.3 +/- 4.2%). These differences did not achieve statistical significance. With appropriate cutoff values, sensitivity and specificity, respectively, were found to be 80.4% and 72.7% for the most suspect curve, 76.1% and 83.6% for the curve-type distribution percentage, and 78.3% and 84.5% for both parameters. The integration of whole-lesion dynamic data tends to improve specificity. However, no statistical significance backs up this finding.

Design of an integrated master-slave robotic system for minimally invasive surgery.

PubMed

Li, Jianmin; Zhou, Ningxin; Wang, Shuxin; Gao, Yuanqian; Liu, Dongchun

2012-03-01

Minimally invasive surgery (MIS) robots are commonly used in hospitals and medical centres. However, currently available robotic systems are very complicated and huge, greatly raising system costs and the requirements of operating rooms. These disadvantages have become the major impediments to the expansion of MIS robots. An integrated MIS robotic system is proposed based on the analysis of advantages and disadvantages of different MIS robots. In the proposed system, the master manipulators, slave manipulators, image display device and control system have been designed as a whole. Modular design is adopted for the control system for easy maintenance and upgrade. The kinematic relations between the master and the slave are also investigated and embedded in software to realize intuitive movements of hand and instrument. Finally, animal experiments were designed to test the effectiveness of the robot. The robot realizes natural hand-eye movements between the master and the slave to facilitate MIS operations. The experimental results show that the robot can realize similar functions to those of current commercialized robots. The integrated design simplifies the robotic system and facilitates use of the robot. Compared with the commercialized robots, the proposed MIS robot achieves similar functions and features but with a smaller size and less weight. Copyright © 2011 John Wiley & Sons, Ltd.

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.

Pacific Fleet Regional Inventory Stocking Model (PRISM)

DTIC Science & Technology

2003-06-01

Fleet Inventory Management Form ..........................................................................99 19. Master Parts List Input Form...100 20. Master Parts List Update Form...107 26. Master Parts List by APL Report..............................................................................109 27. Master

Rapid and inexpensive fabrication of polymeric microfluidic devices via toner transfer masking

PubMed Central

Easley, Christopher J.; Benninger, Richard K. P.; Shaver, Jesse H.; Head, W. Steven; Piston, David W.

2009-01-01

Summary An alternative fabrication method is presented for production of masters for single- or multilayer polymeric microfluidic devices in a standard laboratory environment, precluding the need for a cleanroom. This toner transfer masking (TTM) method utilizes an office laser printer to generate a toner pattern which is thermally transferred to a metal master to serve as a mask for etching. With master fabrication times as little as one hour (depending on channel depth) using commercially-available equipment and supplies, this approach should make microfluidic technology more widely accessible to the non-expert—even the non-scientist. The cost of fabrication consumables was estimated to be < $1 per master, over an order of magnitude decrease in consumable costs compared to standard photolithography. In addition, the use of chemical etching allows accurate control over the height of raised features (i.e., channel depths), allowing the flexibility to fabricate multiple depths on a single master with little added time. Resultant devices are shown capable of pneumatic valving, three-dimensional channel formation (using layer-connecting vias), droplet fluidics, and cell imaging and staining. The multiple-depth capabilities of the method are proven useful for cellular analysis by fabrication of handheld, disposable devices used for trapping and imaging of live murine pancreatic islets. The precise fluidic control provided by the microfluidic platform allows subsequent fixing and staining of these cells without significant movement, thus spatial correlation of imaging and staining is attainable—even with rare alpha cells that constitute only ∼10% of the islet cells. PMID:19350094

Exploring the thesis experience of Master of Health professions education graduates: a qualitative study.

PubMed

Skeith, Leslie; Ridinger, Heather; Srinivasan, Sushant; Givi, Babak; Youssef, Nazih; Harris, Ilene

2018-04-27

To explore the thesis experience of recent Master of Health Professions Education (MHPE) graduates in the University of Illinois at Chicago (UIC) program. This is a qualitative case study exploring the experience of MHPE graduates between 2014 and 2016 (n=31). Using convenience sampling, all graduates with an email address (n=30) were invited to participate in an online survey and semi-structured interviews. Interviews were completed in-person or via telephone or video conference; interviewers collected detailed notes and audio recordings.  Two authors independently analyzed the data iteratively using thematic analysis and discrepancies were discussed and resolved. Survey results (n=20, 67%) revealed an average graduation of 5.1 years; 10 graduates (33%) were interviewed. Three themes related to the thesis experience were identified: success factors, challenges, and outcomes. Success factors, when present, promoted completion of a thesis; these included: a supportive program environment, time management, available resources, MHPE foundational coursework, aligning theses with career goals, and identifying a project with limited scope. Challenges made thesis completion more difficult for graduates; these included: institutional factors, personal or professional responsibilities, burnout, externally-imposed deadlines, and barriers in the research process. Despite these challenges, completing the thesis resulted in many professional or personal benefits (outcomes). Multiple success factors and challenges were identified in the master's thesis process among MHPE graduates at UIC. These findings can help students conducting education-based scholarship through the master's thesis process. This study also informs program evaluation and improvements and outlines personal and professional outcomes of completing a master's thesis.

Stochastic model simulation using Kronecker product analysis and Zassenhaus formula approximation.

PubMed

Caglar, Mehmet Umut; Pal, Ranadip

2013-01-01

Probabilistic Models are regularly applied in Genetic Regulatory Network modeling to capture the stochastic behavior observed in the generation of biological entities such as mRNA or proteins. Several approaches including Stochastic Master Equations and Probabilistic Boolean Networks have been proposed to model the stochastic behavior in genetic regulatory networks. It is generally accepted that Stochastic Master Equation is a fundamental model that can describe the system being investigated in fine detail, but the application of this model is computationally enormously expensive. On the other hand, Probabilistic Boolean Network captures only the coarse-scale stochastic properties of the system without modeling the detailed interactions. We propose a new approximation of the stochastic master equation model that is able to capture the finer details of the modeled system including bistabilities and oscillatory behavior, and yet has a significantly lower computational complexity. In this new method, we represent the system using tensors and derive an identity to exploit the sparse connectivity of regulatory targets for complexity reduction. The algorithm involves an approximation based on Zassenhaus formula to represent the exponential of a sum of matrices as product of matrices. We derive upper bounds on the expected error of the proposed model distribution as compared to the stochastic master equation model distribution. Simulation results of the application of the model to four different biological benchmark systems illustrate performance comparable to detailed stochastic master equation models but with considerably lower computational complexity. The results also demonstrate the reduced complexity of the new approach as compared to commonly used Stochastic Simulation Algorithm for equivalent accuracy.

Higher education in health promotion in Europe: a comparative analysis of master's level training programmes using HP-Source.net.

PubMed

König, Claudia; Mittelmark, Maurice B

2008-01-01

This report summarises opportunities in Europe for master's degree level training in health promotion. Using data available at www.HP-Source.net, 105 study programmes at 71 institutions, spread over 20 European countries, were identified that include health promotion as a main subject. The programmes were analysed along a number of dimensions, including title, learning objectives, curricula, learning and teaching methods, entry requirements, duration, accreditation, language(s) of instruction and participation in European educational structures. The present analysis reveals great diversity along all these dimensions, but also several clusters of programmes that offer quite similar education in health promotion. Of special interest is the range of options available in Europe for length of study, ranging from one to two years, with part-time as well as full-time options.

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.

[Sacrocolpopexy - pro laparoscopic].

PubMed

Hatzinger, M; Sohn, M

2012-05-01

Innovative techniques have a really magical attraction for physicians as well as for patients. The number of robotic-assisted procedures worldwide has almost tripled from 80,000 procedures in the year 2007 to 205,000 procedures in 2010. In the same time the total number of Da Vinci surgery systems sold climbed from 800 to 1,400. Advantages, such as three-dimensional visualization, a tremor-filter, an excellent instrument handling with 6 degrees of freedom and better ergonomics, together with aggressive marketing led to a veritable flood of new Da Vinci acquisitions in the whole world. Many just took the opportunity to introduce a new instrument to save a long learning curve and start immediately in the surgical master class.If Da Vinci sacrocolpopexy is compared with the conventional laparoscopic approach, robotic-assisted sacrocolpopexy shows a significantly longer duration of the procedure, a higher need for postoperative analgesics, much higher costs and an identical functional outcome without any advantage over the conventional laparoscopic approach. Although the use of robotic-assisted systems shows a significantly lower learning curve for laparoscopic beginners, it only shows minimal advantages for the experienced laparoscopic surgeon. Therefore it remains uncertain whether robotic-assisted surgery shows a significant advantage compared to the conventional laparoscopic surgery, especially with small reconstructive laparoscopic procedures such as sacrocolpopexy.

Study on the characteristic and application of DFB semiconductor lasers under optical injection for microwave photonics

NASA Astrophysics Data System (ADS)

Pu, Tao; Wang, Wei wei

2018-01-01

In order to apply optical injection effect in Microwave Photonics system, The red-shift effect of the cavity mode of the DFB semiconductor laser under single-frequency optical injection is studied experimentally, and the red-shift curve of the cavity mode is measured. The wavelength-selective amplification property of the DFB semiconductor laser under multi-frequency optical injection is also investigated, and the gain curves for the injected signals in different injection ratios are measured in the experiment. A novel and simple structure to implement a single-passband MPF with wideband tunability based on the wavelength-selective amplification of a DFB semiconductor laser under optical injection is proposed and experimentally demonstrated. MPFs with center frequency tuned from 13 to 41 GHz are realized in the experiment. A wideband and frequency-tunable optoelectronic oscillator based on a directly modulated distributed feedback (DFB) semiconductor laser under optical injection is proposed and experimentally demonstrated. By optical injection, the relaxation oscillation frequency of the DFB laser is enhanced and its high modulation efficiency makes the loop oscillate without the necessary of the electrical filter. An experiment is performed; microwave signals with frequency tuned from 5.98 to 15.22 GHz are generated by adjusting the injection ratio and frequency detuning between the master and slave lasers.

Viscoelastic flow past mono- and bidisperse random arrays of cylinders: flow resistance, topology and normal stress distribution.

PubMed

De, S; Kuipers, J A M; Peters, E A J F; Padding, J T

2017-12-13

We investigate creeping viscoelastic fluid flow through two-dimensional porous media consisting of random arrangements of monodisperse and bidisperse cylinders, using our finite volume-immersed boundary method introduced in S. De, et al., J. Non-Newtonian Fluid Mech., 2016, 232, 67-76. The viscoelastic fluid is modeled with a FENE-P model. The simulations show an increased flow resistance with increase in flow rate, even though the bulk response of the fluid to shear flow is shear thinning. We show that if the square root of the permeability is chosen as the characteristic length scale in the determination of the dimensionless Deborah number (De), then all flow resistance curves collapse to a single master curve, irrespective of the pore geometry. Our study reveals how viscoelastic stresses and flow topologies (rotation, shear and extension) are distributed through the porous media, and how they evolve with increasing De. We correlate the local viscoelastic first normal stress differences with the local flow topology and show that the largest normal stress differences are located in shear flow dominated regions and not in extensional flow dominated regions at higher viscoelasticity. The study shows that normal stress differences in shear flow regions may play a crucial role in the increase of flow resistance for viscoelastic flow through such porous media.

46 CFR 42.15-1 - Information to be supplied to the master.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 2 2014-10-01 2014-10-01 false Information to be supplied to the master. 42.15-1... master. (a) The master of every new vessel shall be supplied with sufficient information in a form... authority. (b) The master of every new vessel, which is not already provided with stability information...

43 CFR 30.122 - Is the judge required to accept the master's recommended decision?

Code of Federal Regulations, 2012 CFR

2012-10-01

... 43 Public Lands: Interior 1 2012-10-01 2011-10-01 true Is the judge required to accept the master... accept the master's recommended decision? No, the judge is not required to accept the master's... the record of the proceedings heard by the master, including any objections and responses filed, and...

46 CFR 11.463 - General requirements for endorsements as master, mate (pilot), and apprentice mate (steersman) of...

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 1 2013-10-01 2013-10-01 false General requirements for endorsements as master, mate... Professional Requirements for Deck Officers § 11.463 General requirements for endorsements as master, mate... endorsements: (1) Master of towing vessels. (2) Master of towing vessels, limited. (3) Mate (pilot) of towing...

21 CFR 111.205 - What is the requirement to establish a master manufacturing record?

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 2 2010-04-01 2010-04-01 false What is the requirement to establish a master... System: Requirements for the Master Manufacturing Record § 111.205 What is the requirement to establish a master manufacturing record? (a) You must prepare and follow a written master manufacturing record for...

46 CFR 11.463 - General requirements for endorsements as master, mate (pilot), and apprentice mate (steersman) of...

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 1 2012-10-01 2012-10-01 false General requirements for endorsements as master, mate... Professional Requirements for Deck Officers § 11.463 General requirements for endorsements as master, mate... endorsements: (1) Master of towing vessels. (2) Master of towing vessels, limited. (3) Mate (pilot) of towing...

21 CFR 111.205 - What is the requirement to establish a master manufacturing record?

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 2 2014-04-01 2014-04-01 false What is the requirement to establish a master... System: Requirements for the Master Manufacturing Record § 111.205 What is the requirement to establish a master manufacturing record? (a) You must prepare and follow a written master manufacturing record for...

46 CFR 11.463 - General requirements for endorsements as master, mate (pilot), and apprentice mate (steersman) of...

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false General requirements for endorsements as master, mate... Professional Requirements for Deck Officers § 11.463 General requirements for endorsements as master, mate... endorsements: (1) Master of towing vessels. (2) Master of towing vessels, limited. (3) Mate (pilot) of towing...

43 CFR 30.122 - Is the judge required to accept the master's recommended decision?

Code of Federal Regulations, 2010 CFR

2010-10-01

... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Is the judge required to accept the master... accept the master's recommended decision? No, the judge is not required to accept the master's... the record of the proceedings heard by the master, including any objections and responses filed, and...

43 CFR 2804.18 - What provisions do Master Agreements contain and what are their limitations?

Code of Federal Regulations, 2013 CFR

2013-10-01

... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false What provisions do Master Agreements....18 What provisions do Master Agreements contain and what are their limitations? (a) A Master...) BLM will not enter into any Agreement that is not in the public interest. (c) If you sign a Master...

46 CFR 42.15-1 - Information to be supplied to the master.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Information to be supplied to the master. 42.15-1... master. (a) The master of every new vessel shall be supplied with sufficient information in a form... authority. (b) The master of every new vessel, which is not already provided with stability information...

43 CFR 2804.18 - What provisions do Master Agreements contain and what are their limitations?

Code of Federal Regulations, 2012 CFR

2012-10-01

... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false What provisions do Master Agreements....18 What provisions do Master Agreements contain and what are their limitations? (a) A Master...) BLM will not enter into any Agreement that is not in the public interest. (c) If you sign a Master...

46 CFR 42.15-1 - Information to be supplied to the master.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 2 2012-10-01 2012-10-01 false Information to be supplied to the master. 42.15-1... master. (a) The master of every new vessel shall be supplied with sufficient information in a form... authority. (b) The master of every new vessel, which is not already provided with stability information...

46 CFR 42.15-1 - Information to be supplied to the master.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 2 2013-10-01 2013-10-01 false Information to be supplied to the master. 42.15-1... master. (a) The master of every new vessel shall be supplied with sufficient information in a form... authority. (b) The master of every new vessel, which is not already provided with stability information...

21 CFR 314.420 - Drug master files.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 5 2014-04-01 2014-04-01 false Drug master files. 314.420 Section 314.420 Food... master files. (a) A drug master file is a submission of information to the Food and Drug Administration by a person (the drug master file holder) who intends it to be used for one of the following purposes...

46 CFR 42.15-1 - Information to be supplied to the master.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 2 2011-10-01 2011-10-01 false Information to be supplied to the master. 42.15-1... master. (a) The master of every new vessel shall be supplied with sufficient information in a form... authority. (b) The master of every new vessel, which is not already provided with stability information...

43 CFR 2804.18 - What provisions do Master Agreements contain and what are their limitations?

Code of Federal Regulations, 2014 CFR

2014-10-01

... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false What provisions do Master Agreements....18 What provisions do Master Agreements contain and what are their limitations? (a) A Master...) BLM will not enter into any Agreement that is not in the public interest. (c) If you sign a Master...

16 CFR § 1011.4 - Forms of advance public notice of meetings; Public Calendar/Master Calendar and Federal Register.

Code of Federal Regulations, 2013 CFR

2013-01-01

...; Public Calendar/Master Calendar and Federal Register. § 1011.4 Section § 1011.4 Commercial Practices... notice of meetings; Public Calendar/Master Calendar and Federal Register. Advance notice of Agency...) Public Calendar/Master Calendar. (1) The printed Public Calendar and the Master Calendar maintained in...

43 CFR 2804.18 - What provisions do Master Agreements contain and what are their limitations?

Code of Federal Regulations, 2011 CFR

2011-10-01

... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false What provisions do Master Agreements....18 What provisions do Master Agreements contain and what are their limitations? (a) A Master...) BLM will not enter into any Agreement that is not in the public interest. (c) If you sign a Master...

46 CFR 11.463 - General requirements for endorsements as master, mate (pilot), and apprentice mate (steersman) of...

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 1 2011-10-01 2011-10-01 false General requirements for endorsements as master, mate... Professional Requirements for Deck Officers § 11.463 General requirements for endorsements as master, mate... endorsements: (1) Master of towing vessels. (2) Master of towing vessels, limited. (3) Mate (pilot) of towing...

43 CFR 30.122 - Is the judge required to accept the master's recommended decision?

Code of Federal Regulations, 2013 CFR

2013-10-01

... 43 Public Lands: Interior 1 2013-10-01 2013-10-01 false Is the judge required to accept the master... accept the master's recommended decision? No, the judge is not required to accept the master's... the record of the proceedings heard by the master, including any objections and responses filed, and...

43 CFR 30.122 - Is the judge required to accept the master's recommended decision?

Code of Federal Regulations, 2014 CFR

2014-10-01

... 43 Public Lands: Interior 1 2014-10-01 2014-10-01 false Is the judge required to accept the master... accept the master's recommended decision? No, the judge is not required to accept the master's... the record of the proceedings heard by the master, including any objections and responses filed, and...

21 CFR 111.205 - What is the requirement to establish a master manufacturing record?

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 2 2013-04-01 2013-04-01 false What is the requirement to establish a master... System: Requirements for the Master Manufacturing Record § 111.205 What is the requirement to establish a master manufacturing record? (a) You must prepare and follow a written master manufacturing record for...

43 CFR 30.122 - Is the judge required to accept the master's recommended decision?

Code of Federal Regulations, 2011 CFR

2011-10-01

... 43 Public Lands: Interior 1 2011-10-01 2011-10-01 false Is the judge required to accept the master... accept the master's recommended decision? No, the judge is not required to accept the master's... the record of the proceedings heard by the master, including any objections and responses filed, and...

Defense.gov Special Report: A Nation's Gratitude

Science.gov Websites

Deployments, 2003-2006 Baghdad, Ramadi Air Force Master Sgt. Jessica R. Coombs Air Force Master Sgt. Jessica R . Coombs 40th Expeditionary Support Squadron June 2011 - December 2011 Ali Air Base Indiana Army Master Sgt Multiple Deployments, 2004-2007 Fallujah, Ramadi Air Force Master Sgt. Jeremy G. Coombs Air Force Master

USNO Master Clock - Naval Oceanography Portal

Science.gov Websites

section Advanced Search... Sections Home Time Earth Orientation Astronomy Meteorology Oceanography Ice You are here: Home › USNO › Precise Time › Master Clock USNO Logo USNO Navigation Master Clock GPS Display Clocks TWSTT Telephone Time NTP Info USNO Master Clock clock vault The USNO Master Clock is the

Master Volunteer Life Cycle: A Wide Angle Lens on the Volunteer Experience

ERIC Educational Resources Information Center

Strauss, Andrea Lorek; Rager, Amy

2017-01-01

Extension master volunteer programs, such as master naturalist and master gardener, often focus heavily on volunteer education. The model presented here describes the full life cycle of a master volunteer's experience in the program, putting education in the context of other essential program components. By zooming out to a wide-angle view of the…

Quality Quandaries: Predicting a Population of Curves

DOE PAGES

Fugate, Michael Lynn; Hamada, Michael Scott; Weaver, Brian Phillip

2017-12-19

We present a random effects spline regression model based on splines that provides an integrated approach for analyzing functional data, i.e., curves, when the shape of the curves is not parametrically specified. An analysis using this model is presented that makes inferences about a population of curves as well as features of the curves.

Quality Quandaries: Predicting a Population of Curves

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

Fugate, Michael Lynn; Hamada, Michael Scott; Weaver, Brian Phillip

We present a random effects spline regression model based on splines that provides an integrated approach for analyzing functional data, i.e., curves, when the shape of the curves is not parametrically specified. An analysis using this model is presented that makes inferences about a population of curves as well as features of the curves.

Scaling Behavior for Ionic Transport and its Fluctuations in Individual Carbon Nanotubes

PubMed Central

Secchi, Eleonora; Niguès, Antoine; Jubin, Laetitia; Siria, Alessandro; Bocquet, Lydéric

2016-01-01

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 pH. PMID:27127970

[Design of Portable Spirometer Based on Internet of Things of Medicine].

PubMed

He, Yichen; Yang, Bo; Xiong, Shiqi; Li, Qing

2018-02-08

A kind of portable device for detecting common lung function parameters is mentioned in this paper. Using the singlechip microcomputer as the master control block to collect and process the data from high-accuracy gas pressure sensor, through the way of parametric calibration and linear interpolation to test and calculate the Forced Vital Capacity (FVC), Peak Expiratory Flow (PEF), Forced Expiratory Volume in one second (FEV1), and FEV1/FVC. Meanwhile, the detected parameters can be uploaded to the intelligent mobile terminal through the wireless transmission module. The device is able to show expiratory volume-time curve and the final parameters clearly, the error of measurement is less than 5%. In addition, that device is small and convenient, not only is good for clinical application, but also can be used for family in a house.

A New Tool for Quality Control

NASA Technical Reports Server (NTRS)

1988-01-01

Diffracto, Ltd. is now offering a new product inspection system that allows detection of minute flaws previously difficult or impossible to observe. Called D-Sight, it represents a revolutionary technique for inspection of flat or curved surfaces to find such imperfections as dings, dents and waviness. System amplifies defects, making them highly visible to simplify decision making as to corrective measures or to identify areas that need further study. CVA 3000 employs a camera, high intensity lamps and a special reflective screen to produce a D- Sight image of light reflected from a surface. Image is captured and stored in a computerized vision system then analyzed by a computer program. A live image of surface is projected onto a video display and compared with a stored master image to identify imperfections. Localized defects measuring less than 1/1000 of an inch are readily detected.

Structural arrest in an ideal gas.

PubMed

van Ketel, Willem; Das, Chinmay; Frenkel, Daan

2005-04-08

We report a molecular dynamics study of a simple model system that has the static properties of an ideal gas, yet exhibits nontrivial "glassy" dynamics behavior at high densities. The constituent molecules of this system are constructs of three infinitely thin hard rods of length L, rigidly joined at their midpoints. The crosses have random but fixed orientation. The static properties of this system are those of an ideal gas, and its collision frequency can be computed analytically. For number densities NL(3)/V>1, the single-particle diffusivity goes to zero. As the system is completely structureless, standard mode-coupling theory cannot describe the observed structural arrest. Nevertheless, the system exhibits many dynamical features that appear to be mode-coupling-like. All high-density incoherent intermediate scattering functions collapse onto master curves that depend only on the wave vector.

Distributed On-line Monitoring System Based on Modem and Public Phone Net

NASA Astrophysics Data System (ADS)

Chen, Dandan; Zhang, Qiushi; Li, Guiru

In order to solve the monitoring problem of urban sewage disposal, a distributed on-line monitoring system is proposed. By introducing dial-up communication technology based on Modem, the serial communication program can rationally solve the information transmission problem between master station and slave station. The realization of serial communication program is based on the MSComm control of C++ Builder 6.0.The software includes real-time data operation part and history data handling part, which using Microsoft SQL Server 2000 for database, and C++ Builder6.0 for user interface. The monitoring center displays a user interface with alarm information of over-standard data and real-time curve. Practical application shows that the system has successfully accomplished the real-time data acquisition from data gather station, and stored them in the terminal database.

Functional principal component analysis of glomerular filtration rate curves after kidney transplant.

PubMed

Dong, Jianghu J; Wang, Liangliang; Gill, Jagbir; Cao, Jiguo

2017-01-01

This article is motivated by some longitudinal clinical data of kidney transplant recipients, where kidney function progression is recorded as the estimated glomerular filtration rates at multiple time points post kidney transplantation. We propose to use the functional principal component analysis method to explore the major source of variations of glomerular filtration rate curves. We find that the estimated functional principal component scores can be used to cluster glomerular filtration rate curves. Ordering functional principal component scores can detect abnormal glomerular filtration rate curves. Finally, functional principal component analysis can effectively estimate missing glomerular filtration rate values and predict future glomerular filtration rate values.

Tight-binding approach to overdamped Brownian motion on a bichromatic periodic potential.

PubMed

Nguyen, P T T; Challis, K J; Jack, M W

2016-02-01

We present a theoretical treatment of overdamped Brownian motion on a time-independent bichromatic periodic potential with spatially fast- and slow-changing components. In our approach, we generalize the Wannier basis commonly used in the analysis of periodic systems to define a basis of S states that are localized at local minima of the potential. We demonstrate that the S states are orthonormal and complete on the length scale of the periodicity of the fast-changing potential, and we use the S-state basis to transform the continuous Smoluchowski equation for the system to a discrete master equation describing hopping between local minima. We identify the parameter regime where the master equation description is valid and show that the interwell hopping rates are well approximated by Kramers' escape rate in the limit of deep potential minima. Finally, we use the master equation to explore the system dynamics and determine the drift and diffusion for the system.

Analysis of mathematical literacy ability based on goal orientation in model eliciting activities learning with murder strategy

NASA Astrophysics Data System (ADS)

Wijayanti, R.; Waluya, S. B.; Masrukan

2018-03-01

The purpose of this research are (1) to analyze the learning quality of MEAs with MURDER strategy, (2) to analyze students’ mathematical literacy ability based on goal orientation in MEAs learning with MURDER strategy. This research is a mixed method research of concurrent embedded type where qualitative method as the primary method. The data were obtained using the methods of scale, observation, test and interviews. The results showed that (1) MEAs Learning with MURDER strategy on students' mathematical literacy ability is qualified, (2) Students who have mastery goal characteristics are able to master the seven components of mathematical literacy process although there are still two components that the solution is less than the maximum. Students who have performance goal characteristics have not mastered the components of mathematical literacy process with the maximum, they are only able to master the ability of using mathematics tool and the other components of mathematical literacy process is quite good.

Gender and diversity topics taught in Commission on Accreditation for Marriage and Family Therapy Education programs.

PubMed

Winston, Ebony Joy; Piercy, Fred P

2010-10-01

This article explores how the topics of gender and diversity are being taught and defined in accredited marriage and family therapy programs through syllabi content analysis and interviews with selected faculty. We examined findings by program (master's and doctoral) and type of training (those that taught specific gender and culture courses and those that attempted to infuse gender and culture throughout the curriculum). We examined 39 syllabi from 21 master's and 18 doctoral training programs. In addition, we conducted 20 interviews with faculty members. (Eighteen were White/Caucasian, one was African American and one was Asian Indian.) Some variation in topic areas was found between master's and doctoral programs and between those programs that offered specific course content and those that offered infused course content. However, qualitative interview data reflected many similarities. Particularly apparent was the level of commitment, transparency, and experiential learning methods professors used, regardless of program level or type. © 2010 American Association for Marriage and Family Therapy.

Postgraduate education in nutrition in south Asia: a huge mismatch between investments and needs.

PubMed

Khandelwal, Shweta; Paul, Tanusree; Haddad, Lawrence; Bhalla, Surbhi; Gillespie, Stuart; Laxminarayan, Ramanan

2014-01-07

Despite decades of nutrition advocacy and programming, the nutrition situation in South Asian countries is alarming. We assume that modern training in nutrition at the post graduate level is an important contributor to building the capacity of individuals to think and act effectively when combating undernutrition. In this context, this paper presents a regional situation analysis of master's level academic initiatives in nutrition with a special focus on the type of programme we think is most likely to be helpful in addressing undernutrition at the population level: Public Health Nutrition (PHN). This situational analysis of Masters in nutrition across South Asian countries viz. India, Pakistan, Bangladesh, Sri Lanka, Afghanistan, Maldives, Nepal, Bhutan was conducted using an intensive and systematic Internet search. Further, detailed information was extracted from the individual institute websites and library visits. Of the 131 master's degree programmes we identified one that was in PHN while another 15 had modules in PHN. Most of these universities and institutions were found in India with a few in Bangladesh and Sri Lanka. In the rest of the countries, neither nutrition nor PHN emerged as an academic discipline at the master's level. In terms of eligibility Indian and Sri Lankan programmes were most inclusive, with the remaining countries restricting eligibility to those with health qualifications. On modules, no country had any on nutrition policy or on nutrition's interactions with agriculture, social protection, water and sanitation or women's empowerment. If a strong focus on public health nutrition is key to reducing undernutrition, then the poor availability of such courses in the region is cause for concern. Nutrition master's courses in general focus too little on the kinds of strategies highlighted in the recent Lancet series on nutrition. Governments seeking to accelerate declines in undernutrition should incentivize the delivery of postgraduate programmes in nutrition and Public Health Nutrition (PHN) that reflect the modern consensus on priority actions. In the absence of PHN type programmes, the competence to scale up nutrition capacity is likely to be impaired and the human potential of millions of infants will continue to be squandered.

Light field analysis and its applications in adaptive optics and surveillance systems

NASA Astrophysics Data System (ADS)

Eslami, Mohammed Ali

An image can only be as good as the optics of a camera or any other imaging system allows it to be. An imaging system is merely a transformation that takes a 3D world coordinate to a 2D image plane. This can be done through both linear/non-linear transfer functions. Depending on the application at hand it is easier to use some models of imaging systems over the others in certain situations. The most well-known models are the 1) Pinhole model, 2) Thin Lens Model and 3) Thick lens model for optical systems. Using light-field analysis the connection through these different models is described. A novel figure of merit is presented on using one optical model over the other for certain applications. After analyzing these optical systems, their applications in plenoptic cameras for adaptive optics applications are introduced. A new technique to use a plenoptic camera to extract information about a localized distorted planar wave front is described. CODEV simulations conducted in this thesis show that its performance is comparable to those of a Shack-Hartmann sensor and that they can potentially increase the dynamic range of angles that can be extracted assuming a paraxial imaging system. As a final application, a novel dual PTZ-surveillance system to track a target through space is presented. 22X optic zoom lenses on high resolution pan/tilt platforms recalibrate a master-slave relationship based on encoder readouts rather than complicated image processing algorithms for real-time target tracking. As the target moves out of a region of interest in the master camera, it is moved to force the target back into the region of interest. Once the master camera is moved, a precalibrated lookup table is interpolated to compute the relationship between the master/slave cameras. The homography that relates the pixels of the master camera to the pan/tilt settings of the slave camera then continue to follow the planar trajectories of targets as they move through space at high accuracies.

Learning curves and impact of previous operative experience on performance on a virtual reality simulator to test laparoscopic surgical skills.

PubMed

Grantcharov, Teodor P; Bardram, Linda; Funch-Jensen, Peter; Rosenberg, Jacob

2003-02-01

The study was carried out to analyze the learning rate for laparoscopic skills on a virtual reality training system and to establish whether the simulator was able to differentiate between surgeons with different laparoscopic experience. Forty-one surgeons were divided into three groups according to their experience in laparoscopic surgery: masters (group 1, performed more than 100 cholecystectomies), intermediates (group 2, between 15 and 80 cholecystectomies), and beginners (group 3, fewer than 10 cholecystectomies) were included in the study. The participants were tested on the Minimally Invasive Surgical Trainer-Virtual Reality (MIST-VR) 10 consecutive times within a 1-month period. Assessment of laparoscopic skills included time, errors, and economy of hand movement, measured by the simulator. The learning curves regarding time reached plateau after the second repetition for group 1, the fifth repetition for group 2, and the seventh repetition for group 3 (Friedman's tests P <0.05). Experienced surgeons did not improve their error or economy of movement scores (Friedman's tests, P >0.2) indicating the absence of a learning curve for these parameters. Group 2 error scores reached plateau after the first repetition, and group 3 after the fifth repetition. Group 2 improved their economy of movement score up to the third repetition and group 3 up to the sixth repetition (Friedman's tests, P <0.05). Experienced surgeons (group 1) demonstrated best performance parameters, followed by group 2 and group 3 (Mann-Whitney test P <0.05). Different learning curves existed for surgeons with different laparoscopic background. The familiarization rate on the simulator was proportional to the operative experience of the surgeons. Experienced surgeons demonstrated best laparoscopic performance on the simulator, followed by those with intermediate experience and the beginners. These differences indicate that the scoring system of MIST-VR is sensitive and specific to measuring skills relevant for laparoscopic surgery.

Finite element analysis of the Wolf Creek multispan curved girder bridge.

DOT National Transportation Integrated Search

2008-01-01

The use of curved girder bridges in highway construction has grown steadily during the last 40 years. Today, roughly 25% of newly constructed bridges have a curved alignment. Curved girder bridges have numerous complicating geometric features that di...

Intelligence Support to Supply Chain Risk Management

DTIC Science & Technology

2012-06-01

of Master of Science in Operations Analysis Charles L. Carter, MA Major, USAF June 2012 DISTRIBUTION STATEMENT A. APPROVED FOR...literature regarding supply chain risk management and intelligence doctrine. This review established the importance of supply chain risk analysis to...risk analysis . This research culminated in the development of a methodology for intelligence professionals to use to support supply chain risk

Systematic review of learning curves for minimally invasive abdominal surgery: a review of the methodology of data collection, depiction of outcomes, and statistical analysis.

PubMed

Harrysson, Iliana J; Cook, Jonathan; Sirimanna, Pramudith; Feldman, Liane S; Darzi, Ara; Aggarwal, Rajesh

2014-07-01

To determine how minimally invasive surgical learning curves are assessed and define an ideal framework for this assessment. Learning curves have implications for training and adoption of new procedures and devices. In 2000, a review of the learning curve literature was done by Ramsay et al and it called for improved reporting and statistical evaluation of learning curves. Since then, a body of literature is emerging on learning curves but the presentation and analysis vary. A systematic search was performed of MEDLINE, EMBASE, ISI Web of Science, ERIC, and the Cochrane Library from 1985 to August 2012. The inclusion criteria are minimally invasive abdominal surgery formally analyzing the learning curve and English language. 592 (11.1%) of the identified studies met the selection criteria. Time is the most commonly used proxy for the learning curve (508, 86%). Intraoperative outcomes were used in 316 (53%) of the articles, postoperative outcomes in 306 (52%), technical skills in 102 (17%), and patient-oriented outcomes in 38 (6%) articles. Over time, there was evidence of an increase in the relative amount of laparoscopic and robotic studies (P < 0.001) without statistical evidence of a change in the complexity of analysis (P = 0.121). Assessment of learning curves is needed to inform surgical training and evaluate new clinical procedures. An ideal analysis would account for the degree of complexity of individual cases and the inherent differences between surgeons. There is no single proxy that best represents the success of surgery, and hence multiple outcomes should be collected.

Anthropometric, physical function and general health markers of Masters athletes: a cross-sectional study

PubMed Central

Climstein, Mike; Quilter, Clodagh; Buckley, Georgina; Henwood, Timothy; Grigg, Josie; Keogh, Justin W.L.

2017-01-01

Once the general decline in muscle mass, muscle strength and physical performance falls below specific thresholds, the middle aged or older adult will be diagnosed as having sarcopenia (a loss of skeletal muscle mass and strength). Sarcopenia contributes to a range of adverse events in older age including disability, hospitalisation, institutionalisation and falls. One potentially relevant but understudied population for sarcopenia researchers would be Masters athletes. Masters sport is becoming more common as it allows athletes (typically 40 years and older) the opportunity to participate in individual and/or team sports against individuals of similar age. This study examined a variety of measures of anthropometric, physical function and general health markers in the male and female Masters athletes who competed at the 2014 Pan Pacific Masters Games held on the Gold Coast, Australia. Bioelectrical impedance analysis was used to collect body fat percentage, fat mass and fat-free mass; with body mass, height, body mass index (BMI) and sarcopenic status also recorded. Physical function was quantified by handgrip strength and habitual walking speed; with general health described by the number of chronic diseases and prescribed medications. Between group analyses utilised ANOVA and Tukey’s post-hoc tests to examine the effect of age group (40–49, 50–59, 60–69 and >70 years old) on the outcome measures for the entire sample as well as the male and female sub-groups. A total of 156 athletes (78 male, 78 female; mean 55.7 years) provided informed consent to participate in this study. These athletes possessed substantially better anthropometric, physical function and general health characteristics than the literature for their less physically active age-matched peers. No Masters athletes were categorised as being sarcopenic, although one participant had below normal physical performance and six participants had below normal muscle strength. In contrast, significant age-related reductions in handgrip strength and increases in the number of chronic diseases and prescribed medications were observed for the overall cohort as well as the male and female sub-groups. Nevertheless, even those aged over 70 years only averaged one chronic disease and one prescribed medication. These results may suggest that participation in Masters sport helps to maintain anthropometry, physical function and general health in middle-aged and older adults. However, it is also possible that only healthier middle-aged and older adults with favourable body composition and physical function may be able to participate in Masters sport. Future research should therefore utilise longitudinal research designs to determine the health and functional benefits of Master sports participation for middle-aged and older adults. PMID:28894644

Master equations and the theory of stochastic path integrals

NASA Astrophysics Data System (ADS)

Weber, Markus F.; Frey, Erwin

2017-04-01

This review provides a pedagogic and self-contained introduction to master equations and to their representation by path integrals. Since the 1930s, master equations have served as a fundamental tool to understand the role of fluctuations in complex biological, chemical, and physical systems. Despite their simple appearance, analyses of master equations most often rely on low-noise approximations such as the Kramers-Moyal or the system size expansion, or require ad-hoc closure schemes for the derivation of low-order moment equations. We focus on numerical and analytical methods going beyond the low-noise limit and provide a unified framework for the study of master equations. After deriving the forward and backward master equations from the Chapman-Kolmogorov equation, we show how the two master equations can be cast into either of four linear partial differential equations (PDEs). Three of these PDEs are discussed in detail. The first PDE governs the time evolution of a generalized probability generating function whose basis depends on the stochastic process under consideration. Spectral methods, WKB approximations, and a variational approach have been proposed for the analysis of the PDE. The second PDE is novel and is obeyed by a distribution that is marginalized over an initial state. It proves useful for the computation of mean extinction times. The third PDE describes the time evolution of a ‘generating functional’, which generalizes the so-called Poisson representation. Subsequently, the solutions of the PDEs are expressed in terms of two path integrals: a ‘forward’ and a ‘backward’ path integral. Combined with inverse transformations, one obtains two distinct path integral representations of the conditional probability distribution solving the master equations. We exemplify both path integrals in analysing elementary chemical reactions. Moreover, we show how a well-known path integral representation of averaged observables can be recovered from them. Upon expanding the forward and the backward path integrals around stationary paths, we then discuss and extend a recent method for the computation of rare event probabilities. Besides, we also derive path integral representations for processes with continuous state spaces whose forward and backward master equations admit Kramers-Moyal expansions. A truncation of the backward expansion at the level of a diffusion approximation recovers a classic path integral representation of the (backward) Fokker-Planck equation. One can rewrite this path integral in terms of an Onsager-Machlup function and, for purely diffusive Brownian motion, it simplifies to the path integral of Wiener. To make this review accessible to a broad community, we have used the language of probability theory rather than quantum (field) theory and do not assume any knowledge of the latter. The probabilistic structures underpinning various technical concepts, such as coherent states, the Doi-shift, and normal-ordered observables, are thereby made explicit.

Master equations and the theory of stochastic path integrals.

PubMed

Weber, Markus F; Frey, Erwin

2017-04-01

This review provides a pedagogic and self-contained introduction to master equations and to their representation by path integrals. Since the 1930s, master equations have served as a fundamental tool to understand the role of fluctuations in complex biological, chemical, and physical systems. Despite their simple appearance, analyses of master equations most often rely on low-noise approximations such as the Kramers-Moyal or the system size expansion, or require ad-hoc closure schemes for the derivation of low-order moment equations. We focus on numerical and analytical methods going beyond the low-noise limit and provide a unified framework for the study of master equations. After deriving the forward and backward master equations from the Chapman-Kolmogorov equation, we show how the two master equations can be cast into either of four linear partial differential equations (PDEs). Three of these PDEs are discussed in detail. The first PDE governs the time evolution of a generalized probability generating function whose basis depends on the stochastic process under consideration. Spectral methods, WKB approximations, and a variational approach have been proposed for the analysis of the PDE. The second PDE is novel and is obeyed by a distribution that is marginalized over an initial state. It proves useful for the computation of mean extinction times. The third PDE describes the time evolution of a 'generating functional', which generalizes the so-called Poisson representation. Subsequently, the solutions of the PDEs are expressed in terms of two path integrals: a 'forward' and a 'backward' path integral. Combined with inverse transformations, one obtains two distinct path integral representations of the conditional probability distribution solving the master equations. We exemplify both path integrals in analysing elementary chemical reactions. Moreover, we show how a well-known path integral representation of averaged observables can be recovered from them. Upon expanding the forward and the backward path integrals around stationary paths, we then discuss and extend a recent method for the computation of rare event probabilities. Besides, we also derive path integral representations for processes with continuous state spaces whose forward and backward master equations admit Kramers-Moyal expansions. A truncation of the backward expansion at the level of a diffusion approximation recovers a classic path integral representation of the (backward) Fokker-Planck equation. One can rewrite this path integral in terms of an Onsager-Machlup function and, for purely diffusive Brownian motion, it simplifies to the path integral of Wiener. To make this review accessible to a broad community, we have used the language of probability theory rather than quantum (field) theory and do not assume any knowledge of the latter. The probabilistic structures underpinning various technical concepts, such as coherent states, the Doi-shift, and normal-ordered observables, are thereby made explicit.

Dismantling a Master Narrative: Using Culturally Responsive Pedagogy to Teach the History of Art Education

ERIC Educational Resources Information Center

Acuff, Joni Boyd; Hirak, Brent; Nangah, Mary

2012-01-01

The consequence of narratives becoming stagnant or controlled is that they become a Master Narrative. The Master Narrative is an "ideological script that is being imposed by the people in authority on everybody else: The Master Fiction... history" (Moyers, 1990, para. 4). Master Narratives use myths and ideologies to sustain a sanitized version of…

46 CFR 11.459 - Service requirements for master or mate of rivers.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 1 2011-10-01 2011-10-01 false Service requirements for master or mate of rivers. 11... requirements for master or mate of rivers. (a) An applicant for an endorsement as master of river steam or motor vessels of any gross tons must meet the same service requirements as master of inland steam or...

46 CFR 11.459 - Service requirements for master or mate of rivers.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 1 2012-10-01 2012-10-01 false Service requirements for master or mate of rivers. 11... requirements for master or mate of rivers. (a) An applicant for an endorsement as master of river steam or motor vessels of any gross tons must meet the same service requirements as master of inland steam or...

46 CFR 11.459 - Service requirements for master or mate of rivers.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Service requirements for master or mate of rivers. 11... requirements for master or mate of rivers. (a) An applicant for an endorsement as master of river steam or motor vessels of any gross tons must meet the same service requirements as master of inland steam or...

46 CFR 11.459 - Service requirements for master or mate of rivers.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 1 2013-10-01 2013-10-01 false Service requirements for master or mate of rivers. 11... requirements for master or mate of rivers. (a) An applicant for an endorsement as master of river steam or motor vessels of any gross tons must meet the same service requirements as master of inland steam or...

Performance Comparison of Al-Ti Master Alloys with Different Microstructures in Grain Refinement of Commercial Purity Aluminum.

PubMed

Ding, Wanwu; Xia, Tiandong; Zhao, Wenjun

2014-05-07

Three types of Al-5Ti master alloys were synthesized by a method of thermal explosion reaction in pure molten aluminum. Performance comparison of Al-5Ti master alloy in grain refinement of commercial purity Al with different additions (0.6%, 1.0%, 1.6%, 2.0%, and 3.0%) and holding time (10, 30, 60 and 120 min) were investigated. The results show that Al-5Ti master alloy with blocky TiAl₃ particles clearly has better refining efficiency than the master alloy with mixed TiAl₃ particles and the master alloy with needle-like TiAl₃ particles. The structures of master alloys, differing by sizes, morphologies and quantities of TiAl₃ crystals, were found to affect the pattern of the grain refining properties with the holding time. The grain refinement effect was revealed to reduce markedly for master alloys with needle-like TiAl₃ crystals and to show the further significant improvement at a longer holding time for the master alloy containing both larger needle-like and blocky TiAl₃ particles. For the master alloy with finer blocky particles, the grain refining effect did not obviously decrease during the whole studied range of the holding time.

NEXT Performance Curve Analysis and Validation

NASA Technical Reports Server (NTRS)

Saripalli, Pratik; Cardiff, Eric; Englander, Jacob

2016-01-01

Performance curves of the NEXT thruster are highly important in determining the thruster's ability in performing towards mission-specific goals. New performance curves are proposed and examined here. The Evolutionary Mission Trajectory Generator (EMTG) is used to verify variations in mission solutions based on both available thruster curves and the new curves generated. Furthermore, variations in BOL and EOL curves are also examined. Mission design results shown here validate the use of EMTG and the new performance curves.

Deformation and Life Analysis of Composite Flywheel Disk and Multi-disk Systems

NASA Technical Reports Server (NTRS)

Arnold, S. M.; Saleeb, A. F.; AlZoubi, N. R.

2001-01-01

In this study an attempt is made to put into perspective the problem of a rotating disk, be it a single disk or a number of concentric disks forming a unit. An analytical model capable of performing an elastic stress analysis for single/multiple, annular/solid, anisotropic/isotropic disk systems, subjected to both pressure surface tractions, body forces (in the form of temperature-changes and rotation fields) and interfacial misfits is derived and discussed. Results of an extensive parametric study are presented to clearly define the key design variables and their associated influence. In general the important parameters were identified as misfit, mean radius, thickness, material property and/or load gradation, and speed; all of which must be simultaneously optimized to achieve the "best" and most reliable design. Also, the important issue of defining proper performance/merit indices (based on the specific stored energy), in the presence of multiaxiality and material anisotropy is addressed. These merit indices are then utilized to discuss the difference between flywheels made from PMC and TMC materials with either an annular or solid geometry. Finally two major aspects of failure analysis, that is the static and cyclic limit (burst) speeds are addressed. In the case of static limit loads, upper, lower, and out-of-plane bounds for disks with constant thickness are presented for both the case of internal pressure loading (as one would see in a hydroburst test) and pure rotation (as in the case of a free spinning disk). The results (interaction diagrams) are displayed graphically in designer friendly format. For the case of fatigue, a representative fatigue/life master curve is illustrated in which the normalized limit speed versus number of applied cycles is given for a cladded TMC disk application.

Eager protocol on a cache pipeline dataflow

DOEpatents

Ohmacht, Martin; Sugavanam, Krishnan

2012-11-13

A master device sends a request to communicate with a slave device to a switch. The master device waits for a period of cycles the switch takes to decide whether the master device can communicate with the slave device, and the master device sends data associated with the request to communicate at least after the period of cycles has passed since the master device sent the request to communicate to the switch without waiting to receive an acknowledgment from the switch that the master device can communicate with the slave device.

Infusing research integrity principles and practices into a regional master's degree-intensive university: a case study.

PubMed

Thompson, Carla J; Podemski, Richard; Brown, H Quincy

2012-01-01

The need for institutions of higher education to advance research and scholarly integrity across graduate degree programs involves a strong commitment from each institution to develop a comprehensive approach for promoting responsible conduct of research (RCR). In response to this need, one master's-intensive regional university implemented a three-tier model project (focusing, developing, and evaluating/sustaining) for infusing research integrity principles and practices while promoting RCR. Components of the model and implementation strategies are presented as a case study analysis. Implications of the model for promoting the RCR are projected relative to graduate programs focused on applied research.

[Use of bivariate survival curves for analyzing mortality of heart failure and sudden death in dilated cardiomiopathy].

PubMed

Gregori, Dario; Rosato, Rosalba; Zecchin, Massimo; Di Lenarda, Andrea

2005-01-01

This paper discusses the use of bivariate survival curves estimators within the competing risk framework. Competing risks models are used for the analysis of medical data with more than one cause of death. The case of dilated cardiomiopathy is explored. Bivariate survival curves plot the conjoint mortality processes. The different graphic representation of bivariate survival analysis is the major contribute of this methodology to the competing risks analysis.

A novel statistical approach for identification of the master regulator transcription factor.

PubMed

Sikdar, Sinjini; Datta, Susmita

2017-02-02

Transcription factors are known to play key roles in carcinogenesis and therefore, are gaining popularity as potential therapeutic targets in drug development. A 'master regulator' transcription factor often appears to control most of the regulatory activities of the other transcription factors and the associated genes. This 'master regulator' transcription factor is at the top of the hierarchy of the transcriptomic regulation. Therefore, it is important to identify and target the master regulator transcription factor for proper understanding of the associated disease process and identifying the best therapeutic option. We present a novel two-step computational approach for identification of master regulator transcription factor in a genome. At the first step of our method we test whether there exists any master regulator transcription factor in the system. We evaluate the concordance of two ranked lists of transcription factors using a statistical measure. In case the concordance measure is statistically significant, we conclude that there is a master regulator. At the second step, our method identifies the master regulator transcription factor, if there exists one. In the simulation scenario, our method performs reasonably well in validating the existence of a master regulator when the number of subjects in each treatment group is reasonably large. In application to two real datasets, our method ensures the existence of master regulators and identifies biologically meaningful master regulators. An R code for implementing our method in a sample test data can be found in http://www.somnathdatta.org/software . We have developed a screening method of identifying the 'master regulator' transcription factor just using only the gene expression data. Understanding the regulatory structure and finding the master regulator help narrowing the search space for identifying biomarkers for complex diseases such as cancer. In addition to identifying the master regulator our method provides an overview of the regulatory structure of the transcription factors which control the global gene expression profiles and consequently the cell functioning.

Publishing scientific papers based on Master's and Ph.D. theses from a small scientific community: case study of Croatian medical schools.

PubMed

Frković, Vedran; Skender, Tomislav; Dojćinović, Bojan; Bilić-Zulle, Lidija

2003-02-01

To evaluate publishing activity of medical doctors after they have obtained Master's or Ph.D. degree at the Rijeka and Zagreb University Schools of Medicine in Croatia, and establish the number of journal articles based on these theses. Data on Master's and Ph.D. theses defended at the Rijeka and Zagreb University Schools of Medicine in the 1990-1999 period were collected by hand-search of the archive. MEDLINE and Current Contents databases were searched for journal articles resulting from the theses. During the 10-year period, 1,535 Master's and 634 Ph.D. theses were defended at the Rijeka and Zagreb University Schools of Medicine (253 Master's and 138 Ph.D. theses from Rijeka and 1,282 Master's and 496 Ph.D. theses from Zagreb). There were 201 (14%) Master's and 218 (34%) Ph.D. theses that resulted in articles published in journals indexed in MEDLINE (13% of Master's and 11% of Ph.D. theses from Rijeka, and 14% of Master's and 41% of Ph.D. theses from Zagreb). Also, 97 (6%) Master's and 129 (20%) Ph.D. theses that resulted in articles published in Current Contents journals (8% of Master's and 6% of Ph.D. theses from Rijeka, and 6% of Master's and 24% of Ph.D. theses from Zagreb). There was no significant difference between the two Universities with respect to published articles based on Master's theses, but there were significantly more articles from Ph.D. theses in Zagreb (p<0.001). Most of the theses resulted in a single publication (95%), 19 (5%) in 2, and 2 in 3 publications. Out of all 453 journal articles, 31% were published in Croatian and 69% in international journals. Most Croatian Master's and Ph.D. theses are not made available to the scientific community. There should be more institutional effort directed at the stimulation of postgraduate students to publish their scientific work.

Mathcad in the Chemistry Curriculum Symbolic Software in the Chemistry Curriculum

NASA Astrophysics Data System (ADS)

Zielinski, Theresa Julia

2000-05-01

Physical chemistry is such a broad discipline that the topics we expect average students to complete in two semesters usually exceed their ability for meaningful learning. Consequently, the number and kind of topics and the efficiency with which students can learn them are important concerns. What topics are essential and what can we do to provide efficient and effective access to those topics? How do we accommodate the fact that students come to upper-division chemistry courses with a variety of nonuniformly distributed skills, a bit of calculus, and some physics studied one or more years before physical chemistry? The critical balance between depth and breadth of learning in courses and curricula may be achieved through appropriate use of technology and especially through the use of symbolic mathematics software. Software programs such as Mathcad, Mathematica, and Maple, however, have learning curves that diminish their effectiveness for novices. There are several ways to address the learning curve conundrum. First, basic instruction in the software provided during laboratory sessions should be followed by requiring laboratory reports that use the software. Second, one should assign weekly homework that requires the software and builds student skills within the discipline and with the software. Third, a complementary method, supported by this column, is to provide students with Mathcad worksheets or templates that focus on one set of related concepts and incorporate a variety of features of the software that they are to use to learn chemistry. In this column we focus on two significant topics for young chemists. The first is curve-fitting and the statistical analysis of the fitting parameters. The second is the analysis of the rotation/vibration spectrum of a diatomic molecule, HCl. A broad spectrum of Mathcad documents exists for teaching chemistry. One collection of 50 documents can be found at http://www.monmouth.edu/~tzielins/mathcad/Lists/index.htm. Another collection of peer-reviewed documents is developing through this column at the JCE Internet Web site, http://jchemed.chem.wisc.edu/JCEWWW/Features/ McadInChem/index.html. With this column we add three peer-reviewed and tested Mathcad documents to the JCE site. In Linear Least-Squares Regression, Sidney H. Young and Andrzej Wierzbicki demonstrate various implicit and explicit methods for determining the slope and intercept of the regression line for experimental data. The document shows how to determine the standard deviation for the slope, the intercept, and the standard deviation of the overall fit. Students are next given the opportunity to examine the confidence level for the fit through the Student's t-test. Examination of the residuals of the fit leads students to explore the possibility of rejecting points in a set of data. The document concludes with a discussion of and practice with adding a quadratic term to create a polynomial fit to a set of data and how to determine if the quadratic term is statistically significant. There is full documentation of the various steps used throughout the exposition of the statistical concepts. Although the statistical methods presented in this worksheet are generally accessible to average physical chemistry students, an instructor would be needed to explain the finer points of the matrix methods used in some sections of the worksheet. The worksheet is accompanied by a set of data for students to use to practice the techniques presented. It would be worthwhile for students to spend one or two laboratory periods learning to use the concepts presented and then to apply them to experimental data they have collected for themselves. Any linear or linearizable data set would be appropriate for use with this Mathcad worksheet. Alternatively, instructors may select sections of the document suited to the skill level of their students and the laboratory tasks at hand. In a second Mathcad document, Non-Linear Least-Squares Regression, Young and Wierzbicki introduce the basic concepts of nonlinear curve-fitting and develop the techniques needed to fit a variety of mathematical functions to experimental data. This approach is especially important when mathematical models for chemical processes cannot be linearized. In Mathcad the Levenberg-Marquardt algorithm is used to determine the best fitting parameters for a particular mathematical model. As in linear least-squares, the goal of the fitting process is to find the values for the fitting parameters that minimize the sum of the squares of the deviations between the data and the mathematical model. Students are asked to determine the fitting parameters, use the Hessian matrix to compute the standard deviation of the fitting parameters, test for the significance of the parameters using Student's t-test, use residual analysis to test for data points to remove, and repeat the calculations for another set of data. The nonlinear least-squares procedure follows closely on the pattern set up for linear least-squares by the same authors (see above). If students master the linear least-squares worksheet content they will be able to master the nonlinear least-squares technique (see also refs 1, 2). In the third document, The Analysis of the Vibrational Spectrum of a Linear Molecule by Richard Schwenz, William Polik, and Sidney Young, the authors build on the concepts presented in the curve fitting worksheets described above. This vibrational analysis document, which supports a classic experiment performed in the physical chemistry laboratory, shows how a Mathcad worksheet can increase the efficiency by which a set of complicated manipulations for data reduction can be made more accessible for students. The increase in efficiency frees up time for students to develop a fuller understanding of the physical chemistry concepts important to the interpretation of spectra and understanding of bond vibrations in general. The analysis of the vibration/rotation spectrum for a linear molecule worksheet builds on the rich literature for this topic (3). Before analyzing their own spectral data, students practice and learn the concepts and methods of the HCl spectral analysis by using the fundamental and first harmonic vibrational frequencies provided by the authors. This approach has a fundamental pedagogical advantage. Most explanations in laboratory texts are very concise and lack mathematical details required by average students. This Mathcad worksheet acts as a tutor; it guides students through the essential concepts for data reduction and lets them focus on learning important spectroscopic concepts. The Mathcad worksheet is amply annotated. Students who have moderate skill with the software and have learned about regression analysis from the curve-fitting worksheets described in this column will be able to complete and understand their analysis of the IR spectrum of HCl. The three Mathcad worksheets described here stretch the physical chemistry curriculum by presenting important topics in forms that students can use with only moderate Mathcad skills. The documents facilitate learning by giving students opportunities to interact with the material in meaningful ways in addition to using the documents as sources of techniques for building their own data-reduction worksheets. However, working through these Mathcad worksheets is not a trivial task for the average student. Support needs to be provided by the instructor to ease students through more advanced mathematical and Mathcad processes. These worksheets raise the question of how much we can ask diligent students to do in one course and how much time they need to spend to master the essential concepts of that course. The Mathcad documents and associated PDF versions are available at the JCE Internet WWW site. The Mathcad documents require Mathcad version 6.0 or higher and the PDF files require Adobe Acrobat. Every effort has been made to make the documents fully compatible across the various Mathcad versions. Users may need to refer to Mathcad manuals for functions that vary with the Mathcad version number. Literature Cited 1. Bevington, P. R. Data Reduction and Error Analysis for the Physical Sciences; McGraw-Hill: New York, 1969. 2. Zielinski, T. J.; Allendoerfer, R. D. J. Chem. Educ. 1997, 74, 1001. 3. Schwenz, R. W.; Polik, W. F. J. Chem. Educ. 1999, 76, 1302.