bluuebunny/crossref_metadata_2025 huggingface dataset:
Generalised fault diagnostic method for power transistors in asymmetric half‐bridge power converter of SRM drive
Authors: Han Guoqiang , Chen Hao , Guan Guorui
Published: October 2018

This study presents a generalised fault diagnosis method for power transistors in the asymmetric half‐bridge power converter of switched reluctance motor (SRM) drive. In order to extract the remarkable fault features, three current sensors are rearranged. Each phase current can be calculated by solving the equations associated with the detected values of three current sensors and three coefficients obtained based on different switching states. Different faults are preliminarily detected by monitoring the error between the estimated bus current and the actual bus current. After the identification of fault occurrence, the error will be calculated with all the combinations of three coefficients. The minimum error will be found and the corresponding coefficients are recorded. The fault types and fault power transistors are located by comparing the actual coefficients with the recorded coefficients. Being different from the existing methods, the developed diagnostic strategy can detect multiple fault types and can be used in different control modes, including voltage pulse width modulation, current chopping control and angular position control schemes. Moreover, the proposed technique is easy for online implementation without extra sensors and additional electric devices. The effectiveness of the proposed solution is validated on a three‐phase 12/8 SRM drive.
Alternative Süßungsmittel
Authors: Mach Robert
Published: October 2018

Im vorliegenden Artikel wird die Vielfalt an möglichen und derzeit im Handel angebotenen Alternativen zum klassischen Süßungsmittel Saccharose systematisiert. Ausgewählte Vertreter unterschiedlicher Gruppen werden im Speziellen hinsichtlich deren Süßkraft, Energiegehalt und glykämischem Index bewertet. Zusätzliche gesundheits- und umweltrelevante Aspekte werden beleuchtet. So werden die Biotransformation, die Persistenz in der Umwelt, die Energiebilanz, oder die ernährungsphysiologischen Auswirkungen und/oder Verträglichkeiten ausgewählter Substanzen anhand der aktuellen Wissenschaftsliteratur diskutiert und erläutert. Grundsätzlich orientiert sich der Beitrag dazu an einer Einteilung in 3 Stoffgruppen: Zucker im weiteren Sinne, Süßstoffe und Zuckeraustauschstoffe. Zuletzt wird ein mögliches neues Produktionsverfahren zur Herstellung des Zuckeraustauschstoffs Erythrit aus biogenen Reststoffen angesprochen.
Efficient S-Acylation of Thiourea
Authors: Jones David , Khandavilli Uday , O’Leary Eileen , Lawrence Simon , O’Sullivan Timothy
Published: October 2018

Efficient S-acylation of thiourea using a variety of acid chlorides is reported. Structurally diverse aryl and alkyl substrates are compatible with this methodology. Confirmation that acylation occurs exclusively­ on the sulfur atom of thiourea is provided by single-crystal X-ray crystallographic analysis.
Asynchronous Speech Recognition Affects Physician Editing of Notes
Authors: Lybarger Kevin , Ostendorf Mari , Riskin Eve , Payne Thomas , White Andrew , Yetisgen Meliha
Published: October 2018

Objective Clinician progress notes are an important record for care and communication, but there is a perception that electronic notes take too long to write and may not accurately reflect the patient encounter, threatening quality of care. Automatic speech recognition (ASR) has the potential to improve clinical documentation process; however, ASR inaccuracy and editing time are barriers to wider use. We hypothesized that automatic text processing technologies could decrease editing time and improve note quality. To inform the development of these technologies, we studied how physicians create clinical notes using ASR and analyzed note content that is revised or added during asynchronous editing.

Materials and Methods We analyzed a corpus of 649 dictated clinical notes from 9 physicians. Notes were dictated during rounds to portable devices, automatically transcribed, and edited later at the physician's convenience. Comparing ASR transcripts and the final edited notes, we identified the word sequences edited by physicians and categorized the edits by length and content.

Results We found that 40% of the words in the final notes were added by physicians while editing: 6% corresponded to short edits associated with error correction and format changes, and 34% were associated with longer edits. Short error correction edits that affect note accuracy are estimated to be less than 3% of the words in the dictated notes. Longer edits primarily involved insertion of material associated with clinical data or assessment and plans. The longer edits improve note completeness; some could be handled with verbalized commands in dictation.

Conclusion Process interventions to reduce ASR documentation burden, whether related to technology or the dictation/editing workflow, should apply a portfolio of solutions to address all categories of required edits. Improved processes could reduce an important barrier to broader use of ASR by clinicians and improve note quality.
Matrix product states and the quantum max-flow/min-cut conjectures
Authors: Gesmundo Fulvio , Landsberg J. M. , Walter Michael
Published: October 2018

In this note, we discuss the geometry of matrix product states with periodic boundary conditions and provide three infinite sequences of examples where the quantum max-flow is strictly less than the quantum min-cut. In the first, we fix the underlying graph to be a 4-cycle and verify a prediction of Hastings that inequality occurs for infinitely many bond dimensions. In the second, we generalize this result to a 2d-cycle. In the third, we show that the 2d-cycle with periodic boundary conditions gives inequality for all d when all bond dimensions equal two, namely, a gap of at least 2d−2 between the quantum max-flow and the quantum min-cut.
Analysis of droplet dynamics in a partially obstructed confinement in a three-dimensional channel
Authors: Bhardwaj Saurabh , Dalal Amaresh , Biswas Gautam , Mukherjee Partha P.
Published: October 2018

This study presents droplet dynamics due to capillarity-wettability interaction through a partially obstructed channel confinement based on a mesoscopic, two-phase lattice Boltzmann model. To explore the dynamic behavior of droplet motion past an obstruction, the effects of the modified capillary number and surface wettability, including the obstruction size and architecture, are elucidated. In this work, a single spherical obstruction and different spherical agglomerate structures have been considered. The mesoscale simulations exhibit interesting two-phase flow physics and pattern formations due to droplet pinching, break up, and surface adherence owing to the underlying wettability-capillarity characteristics. This study further reveals a trade-off, between the time required for the bulk droplet fluid to pass by and/or through the obstruction and the fraction of the droplet fluid volume adhering to the surface, depending on the combination of the capillary number and surface wettability.
Magnetoresistance in CoFe2O4/BiFeO3 core-shell nanoparticles near room temperature
Authors: Kuila S. , Tiwary Sweta , Sahoo M. R. , Barik A. , Vishwakarma P. N.
Published: October 2018

A systematic study of near room temperature magnetoresistance (MR) behavior is carried out for magnetoelectric CoFe2O4-BiFeO3 core-shell nanoparticles. The analysis of MR data reveals that the MR is guided by the anisotropic magnetoresistance (AMR) and the giant magnetoresistance (GMR) effect. The GMR effect is predominant in the sample having a maximum shell thickness, whereas the AMR effect dominates the least shell thickness and bare CoFe2O4. Analysis of the MR data in conjunction with the resistivity suggests that the electrical conduction in these samples is due to (a) tunneling and (b) hopping of electrons across the domains. The impedance and modulus spectra analysis shows that the core-shell particles as a whole are participating in the relaxation process, thus indicating a strong coupling between the core and shell, which may be highly desirable while fetching their magnetoelectric based applications.
Characterization of shaped Bragg crystal assemblies for narrowband x-ray imaging
Authors: Stoeckl C. , Filkins T. , Jungquist R. , Mileham C. , Pereira N. R. , Regan S. P. , Shoup M. J. , Theobald W.
Published: October 2018

X-ray imaging using shaped crystals in Bragg reflection is a powerful technique used in high-energy-density physics experiments. The characterization of these crystal assemblies with conventional x-ray sources is very difficult because of the required angular resolution of the order of ∼10 μrad and the narrow bandwidth of the crystal. The 10-J, 1-ps Multi-Terawatt (MTW) laser at the Laboratory for Laser Energetics was used to characterize a set of Bragg crystal assemblies. The small spot size (of the order of 5 μm) and the high power (>1018 W/cm2) of this laser make it possible to measure the spatial resolution at the intended photon energy. A set of six crystals from two different vendors was checked on MTW, showing an unexpectedly large variation in spatial resolution of up to a factor of 4.
Characterization of a picosecond gated optical intensifier
Authors: Little B. J.
Published: October 2018

The development of high speed imaging detectors is crucial for high-temperature plasma characterization and optimization. These detectors must perform within many strict parameters, such as precise timing, high spatial resolution, low noise, high gain, and fast gating. We present test results on a picosecond gated optical intensifier that aims to meet these requirements. The detector was developed by Kentech and is part of a packaged Sydor solution of 1-8 detectors, designed for use in plasma diagnostics. It has low jitter (SD 4 ps) and gate widths less than 80 ps. We use a pulsed laser to test the gate profile and the spatial resolution performance of the intensifier at different points within the gate.
In-situ frequency calibration of frequency modulated continuous wave reflectometry
Authors: Seo Seong-Heon
Published: October 2018

Frequency modulated continuous wave reflectometers have been used to measure the plasma density profiles of the KSTAR tokamak. Three reflectometers are operating in an extraordinary polarization mode in the frequency range of Q band (33–50 GHz), V band (50–75 GHz), and W band (75–110 GHz). Each full frequency band is linearly swept in 20 μs. The accuracy of the density profile measurement is dependent on how precisely the frequency is calibrated. Two new frequency measurement techniques are developed to in situ calibrate the instantaneous frequency during the sweep time of 20 μs. First the intermediate frequency (IF) of the receiver is analyzed based on wavelet transform as applying a fixed frequency signal from a synthesizer to the local oscillator (LO) port. The frequency of the transmitted microwave is simply obtained by adding or subtracting the measured IF to the given LO frequency. Once the group delay of the whole system is known, the frequency can be calibrated by measuring the IF. By measuring the reflectometer output without plasma with delay lines of different lengths and subtracting them, the frequency can be calibrated by eliminating the unknown group delay of the system except the known group delay of the delay line. These two techniques are described in detail, and the calibrated frequencies conducted by the two techniques are compared.
Using multiple neutron time of flight detectors to determine the hot spot velocity
Authors: Hatarik R. , Nora R. C. , Spears B. K. , Eckart M. J. , Grim G. P. , Hartouni E. P. , Moore A. S. , Schlossberg D. J.
Published: October 2018

An important diagnostic value of a shot at the National Ignition Facility is the resultant center-of-mass motion of the imploding capsule. This residual velocity reduces the efficiency of converting laser energy into plasma temperature. A new analysis method extracts the effective hot spot motion by using information from multiple neutron time-of-flight (nToF) lines-of-sight (LoSs). This technique fits a near Gaussian spectrum to the nToF scope traces and overcomes reliance on models to relate the plasma temperature to the mean energy of the emitted neutrons. This method requires having at least four nToF LoSs. The results of this analysis will be compared to an approach where each LoS is analyzed separately and a model is used to infer the mean energy of the emitted neutrons.
Modeling tunnel field effect transistors—From interface chemistry to non-idealities to circuit level performance
Authors: Ahmed Sheikh Z. , Tan Yaohua , Truesdell Daniel S. , Calhoun Benton H. , Ghosh Avik W.
Published: October 2018

We present a quasi-analytical model for Tunnel Field Effect Transistors (TFETs) that includes the microscopic physics and chemistry of interfaces and non-idealities. The ballistic band-to-band tunneling current is calculated by modifying the well known Simmons equation for oxide tunneling, where we integrate the Wentzel-Kramers-Brillouin tunneling current over the transverse modes. We extend the Simmons equation to finite temperature and non-rectangular barriers using a two-band model for the channel material and an analytical channel potential profile obtained from Poisson’s equation. The two-band model is parametrized first principles by calibrating with hybrid Density Functional Theory calculations and extended to random alloys with a band unfolding technique. Our quasi-analytical model shows quantitative agreement with ballistic quantum transport calculations. On top of the ballistic tunnel current, we incorporate higher order processes arising at junctions coupling the bands, specifically interface trap assisted tunneling and Auger generation processes. Our results suggest that both processes significantly impact the off-state characteristics of the TFETs—Auger, in particular, being present even for perfect interfaces. We show that our microscopic model can be used to quantify the TFET performance on the atomistic interface quality. Finally, we use our simulations to quantify circuit level metrics such as energy consumption.
Probing elastic properties of nanowire-based structures
Authors: Lu L. , Charron E. , Glushkov E. , Glushkova N. , Bonello B. , Julien F. H. , Gogneau N. , Tchernycheva M. , Boyko O.
Published: October 2018

We report the analysis of elastic properties of a composite medium consisting of GaN nanowires embedded into a dielectric matrix, which constitutes the active material of nanowire-based piezogenerators. A non-invasive technique, Transient Grating Method, is used to generate and analyze the propagation of acoustic waves in the frequency range from a few tens of MHz to several GHz. The wave propagation is simulated using the time-efficient computer model based on the explicit integral and asymptotic representations for laser-generated surface acoustic waves in layered anisotropic waveguides. Effective parameters of the multilayered model are obtained via the minimization of the discrepancy between the measured and calculated wave characteristics. A comparison with a reference composed of a dielectric matrix without nanowires shows that the mechanical behavior is strongly influenced by the presence of the nanostructures.
Proper orthogonal decomposition analysis of a circular cylinder undergoing vortex-induced vibrations
Authors: Riches Graham , Martinuzzi Robert , Morton Chris
Published: October 2018

Proper orthogonal decomposition (POD) is utilized to analyze the wake-dynamics of a low-mass ratio circular cylinder undergoing vortex-induced vibrations in the initial and upper branches (U* = U∞/fND = 4.07, 5.32). POD allows for characterizing dynamics at frequencies which differ from the cylinder oscillation that cannot be captured with conventional phase-averaging. POD modes contributing to the dominant coherent motions are described in detail. Fourier analysis techniques are used to identify relationships between the POD modes describing non-periodic dynamics linked to the slow-varying base flow and result in a modulation in the strength of vortex shedding. Heuristic models based on mean-field theory are proposed for the POD temporal coefficients. The modelled wake dynamics are found to account for a significant contribution to the Reynolds stresses. In the initial branch, it is found that 6 POD modes are required to capture the salient aspects of the flow, while in the upper branch, 7 modes are required.
NO2- and NO3- enhance cold atmospheric plasma induced cancer cell death by generation of ONOO-
Authors: Xu Dehui , Cui Qingjie , Xu Yujing , Liu Zhijie , Chen Zeyu , Xia Wenjie , Zhang Hao , Liu Dingxin , Chen Hailan , Kong Michael G.
Published: October 2018

Cold atmospheric plasma (CAP) is a rapidly developed technology that has been widely applied in biomedicine especially in cancer treatment. Due to the generation of various active species in plasma, CAP could induce various tumor cells death and showed a promising potential in cancer therapy. To enhance the biological effects of gas plasma, changing the discharging parameters is the most commonly used method, yet increasing discharging power will lead to a higher possibility of simultaneously damage surrounding tissues. In this study, by adding nontoxic concentration of additional nitrite and nitrate in the medium, we found that anti-tumor effect of CAP treatment was enhanced in the same discharging parameters. By microplate reader and cell flow cytometer we measured several extracellular and intracellular RONS and found that ONOO- was mostly correlated with the enhanced cancer cell killing effect. We proposed that more nitrogen supplies such as nitrite and nitrate could increase the production of RNS especially ONOO- and resulted in a better killing effect to cancer cells. Our results provided a new strategy to enhance the antitumor effect by plasma jet treatment without changing the discharging parameters.
Multi frame synchrotron radiography of pulsed power driven underwater single wire explosions
Authors: Yanuka D. , Rososhek A. , Theocharous S. , Bland S. N. , Krasik Ya. E. , Olbinado M. P. , Rack A.
Published: October 2018

We present the first use of synchrotron-based phase contrast radiography to study pulsed-power driven high energy density physics experiments. Underwater electrical wire explosions have become of interest to the wider physics community due to their ability to study material properties at extreme conditions and efficiently couple stored electrical energy into intense shock waves in water. The latter can be shaped to provide convergent implosions, resulting in very high pressures (1-10 Mbar) produced on relatively small pulsed power facilities (100s of kA-MA). Multiple experiments have explored single-wire explosions in water, hoping to understand the underlying physics and better optimize this energy transfer process; however, diagnostics can be limited. Optical imaging diagnostics are usually obscured by the shock wave itself; and until now, diode-based X-ray radiography has been of relatively low resolution and rather a broad x-ray energy spectrum. Utilising phase contrast imaging capabilities of the ID19 beamline at the European Synchrotron Radiation Facility, we were able to image both the exploding wire and the shock wave. Probing radiation of 20-50 keV radiographed 200 μm tungsten and copper wires, in ∼2-cm diameter water cylinders with resolutions of 8 μm and 32 μm. The wires were exploded by a ∼30-kA, 500-ns compact pulser, and 128 radiographs, each with a 100-ps X-ray pulse exposure, spaced at 704 ns apart were taken in each experiment. Abel inversion was used to obtain the density profile of the wires, and the results are compared to two dimensional hydrodynamic and one dimensional magnetohydrodynamic simulations.
Pressure induced structural phase transition in rare earth sesquioxide Tm2O3: Experiment and ab initio calculations
Authors: Irshad K. A. , Anees P. , Sahoo Shradhanjali , Sanjay Kumar N. R. , Srihari Velaga , Kalavathi S. , Chandra Shekar N. V.
Published: October 2018

Among the small cation sized rare earth sesquioxides, the reported transition pressure of cubic Tm2O3 is ambiguous. Pressure induced structural phase transition in cubic Tm2O3 has been reinvestigated using the synchrotron X-ray diffraction, Raman spectroscopy, and ab initio density functional theory (DFT) calculations up to a pressure of 25 GPa. Both the X-ray diffraction and Raman spectroscopic measurements revealed an irreversible polymorphic structural phase transition from type-C cubic to type-B monoclinic at around 12 GPa, whereas the same is predicted to be 8 GPa from the density functional theory. The phase transition observed at 12 GPa is in contrast to the literature and the reasoning has been established by other studies, viz., Raman spectroscopy and DFT. A third order Birch-Murnaghan equation of state fit to the experimental compressibility curve yielded a zero pressure bulk modulus of 149(2) GPa with the pressure derivatives 4.8(5) for the parent cubic phase and 169(2) GPa with the pressure derivative 4 for the high pressure monoclinic phase, respectively. These values are in good agreement with the calculated bulk modulus of 146 and 151 GPa for the cubic and monoclinic phases, respectively. Raman modes for the monoclinic phase of Tm2O3 are measured and reported for the first time. The mode Grüneisen parameter of different Raman modes for both cubic and monoclinic phases of Tm2O3 has also been determined. The experimental results are correlated with changes in the density of states near the Fermi level, which are indicative of structural instabilities in the parent cubic structure.
Oscillation responses and wake modes of three staggered rotating cylinders in two- and three-dimensional flows
Authors: Behara Suresh , Chandra Venu , Ravikanth B. , Kotteda V. M. Kurshnarao
Published: October 2018

Oscillation responses and wake modes of three staggered rotating cylinders, free to move in streamwise and transverse directions, are numerically studied in two- (2-D) and three-dimensional (3-D) flows. 2-D computations are carried out for Reynolds number Re = 60–150, employing the following rotation rates (α), respectively, for the upstream, upper, and lower downstream cylinders: 1, 1, 0; 1, 1, 1; 1, 1, −1. Here, the clockwise rotation is positive. 3-D simulations are performed at Re = 2000 and reduced velocity, U* = 2–11, with the three cylinders being rotated at α = 1. Bell-shaped amplitude profiles are observed for all the rotating cylinders, indicating that the bodies undergo vortex-induced vibrations. In 2-D flow, the considered Re regime can be categorized into three distinct regions, based on the oscillation and frequency responses. Cylinders exhibit negligible amplitudes in the first region, whereas the second region is characterized by high amplitude lock-in oscillations for all three cylinders. In the third region, the downstream cylinders exhibit lock-in response in certain rotation configurations. The oscillation responses and wake modes appear sensitive to the direction of rotation of the lower downstream cylinder for the streamwise and transverse gaps of 5 diameters (5D) and 3D, respectively, between the cylinders. Depending on the rotation configuration, 2S, P, and P + S modes of primary shedding are observed. In 3-D flow also, the cylinders exhibit bell-shaped amplitude profiles, contrary to the galloping response noticed for isolated rotating cylinders in few previous studies. Higher and lower amplitude oscillations induce stronger and weaker 3-D flow instabilities, respectively, in the wake region.
Dual mode microwave deflection cavities for ultrafast electron microscopy
Authors: van Rens J. F. M. , Verhoeven W. , Kieft E. R. , Mutsaers P. H. A. , Luiten O. J.
Published: October 2018

This paper presents the experimental realization of an ultrafast electron microscope operating at a repetition rate of 75 MHz based on a single compact resonant microwave cavity operating in a dual mode. This elliptical cavity supports two orthogonal TM110 modes with different resonance frequencies that are driven independently. The microwave signals used to drive the two cavity modes are generated from higher harmonics of the same Ti:Sapphire laser oscillator. Therefore, the modes are accurately phase-locked, resulting in periodic transverse deflection of electrons described by a Lissajous pattern. By sending the periodically deflected beam through an aperture, ultrashort electron pulses are created at a repetition rate of 75 MHz. Electron pulses with τ = (750 ± 10) fs pulse duration are created with only (2.4 ± 0.1) W of microwave input power; with normalized rms emittances of ϵn,x = (2.1 ± 0.2) pm rad and ϵn,y = (1.3 ± 0.2) pm rad for a peak current of Ip = (0.4 ± 0.1) nA. This corresponds to an rms normalized peak brightness of Bnp,rms=(7±1)×106 A/m2 sr V, equal to previous measurements for the continuous beam. In addition, the FWHM energy spread of ΔU = (0.90 ± 0.05) eV is also unaffected by the dual mode cavity. This allows for ultrafast pump-probe experiments at the same spatial resolution of the original TEM in which a 75 MHz Ti:Sapphire oscillator can be used for exciting the sample. Moreover, the dual mode cavity can be used as a streak camera or time-of-flight electron energy loss spectroscopy detector with a dynamic range >104.
Size-dependent effects sensitively determine buckling of a cylindrical silicon electrode particle in a lithium-ion battery
Authors: Neogi Srijan , Chakraborty Jeevanjyoti
Published: October 2018

The influence of size-dependent effects on mechanical behavior of a cylindrical silicon electrode particle within a lithium-ion battery is investigated, and it is shown that these effects sensitively determine critical buckling behavior. The mathematical framework used for this investigation incorporates the bond-order-length-strength (BOLS) theory correlation in a general finite deformation theory model that includes the two-way coupling between diffusion-induced stress and stress-influenced diffusion. Additionally, the possibility of plastic flow is accounted for in the model to allow probing situations with relatively high charging rates. Significant differences, arising due to the consideration of the size-dependent effects and captured through the BOLS theory, are highlighted. In particular, it is found that, in most cases studied, both stresses and plastic stretches are amplified in magnitude. Tensile to compressive stress reversal also takes place faster on considering the BOLS theory. The modeling framework is further applied to estimate critical lengths that are safe against buckling. Thus, it is expected that the presented framework will provide an improved aid for the design of nanowire-based lithium ion battery silicon electrodes.
Development of an CNT field emission UHV ionization gauge with customized electronics
Authors: Sun Jian , Li Detian , Cheng Yongjun , Zhang Huzhong , Wang Yongjun , Li Gang , Han Xiaodong
Published: October 2018

An ionization vacuum gauge with carbon nanotube (CNT) cathode was designed for measurement of ultra high vacuum (UHV). The sensor was constructed based on Bayard-Alpert type gauge. The key index of the control unit is determined by theoretical analysis and experimental results. A customized detection circuit was designed considering the characteristics of the output ion current of the sensor, the performance of which, such as linearity, noise, bandwidth and gain, were determined by a series of tests and calibrations. At last, the vacuum measurement range and uncertainty of this gauge were determined. The test results showed that the lower limit of the CNT-cathode ionization vacuum gauge enters 10-8Pa, The measurement uncertainty is about 4.0% in the pressure range of 10-4Pa-10-7Pa. This work can provide a new solution for UHV measurement.
The effect of surface contamination of tiny satellite on DC probe ionosphere measurement
Authors: Fang H. K. , Chen W. H. , Chen Alfred B. , Oyama K.-I.
Published: October 2018

The DC Langmuir probe is a widely-used instrument for the plasma measurement in the space missions. But to apply DC Langmuir probe to a tiny satellite, such as a cubesat, for ionosphere study is difficult to get accurate electron density (ne) and electron temperature (Te) for two reasons: the contamination on both satellite surface and the electrode to be used, and a lack of conductive surface area of the tiny satellite. Under the charging effect of the satellite with an insufficient area ratio between the surface of the probe and the spacecraft, the contaminations on the surface of both probe and the satellite, acting as equivalent capacitances and resistances, modify both the potentials on the satellite and the probe, and an elevated Te and a suppressed ne are derived incorrectly. In this paper, the effect of the surface contamination on the DC Langmuir probe measurements onboard a tiny satellite is investigated in detail. The effects of the accumulated charge and the impedances on the contamination layers have been identified in the experiments done in a ground chamber with similar plasma conditions in the Earth’s ionosphere, and the characteristic dependences of the probe sweeping frequency and the plasma density are presented. The experiment result suggests that a contamination-free instrument TeNeP, operated at 0.2∼10 MHz probe sweeping frequency and sweeping potentials below 500 mV, is a better solution to obtain accurate Te and ne, onboard a satellite with a surface area ratio below 100.
Effect of depth on the properties of two coupled Faraday waves in a Hele-Shaw cell
Authors: Li Xiaochen , Li Jing , Liao Shijun , Chen Chaohe
Published: October 2018

A new type of coupled Faraday wave appears in the system of two immiscible incompressible viscous liquid layers with a free surface filling in a Hele-Shaw cell under vertical oscillation [X. Li, X. Li, and S. Liao, “Observation of two coupled Faraday waves in a vertically vibrating Hele-Shaw cell with one of them oscillating horizontally,” Phys. Fluids, 30, 012108 (2018)]. The influence in terms of both depth of upper and lower liquids on these standing waves has been analyzed quantitatively by experiments, which can be understood in the form of the wave amplitudes, dispersion relation, and stability. It suggests that the depth of upper liquid plays a remarkable role, while the lower one does not seem to contribute significantly.
Aging of silver nanocolloids in sunlight: particle size has a major influence
Authors: Motellier Sylvie , Pélissier Nathalie , Mattei Jean-Gabriel
Published: October 2018

Environmental contextTransformation of silver nanoparticles in the environment is an important issue because the form they take directly influences what effect they have. We show that the size of the primary particles of silver nanosuspensions is a major factor determining their evolution under sunlight irradiation (dissolution, formation of nanoseeds and nanoprisms, agglomeration). The persistence of nano-sized silver particles after exposure to sunlight irradiation implies that their ecotoxicological impact will likely last well beyond their introduction in the environment.
AbstractThe environmental fate of silver nanoparticles (Ag NPs) is a serious cause for concern with regard to their ecotoxicity. In this study, an aging scenario intended to evaluate the effect of sunlight on three Ag NP suspensions of various particle size was assessed. Suspensions of citrate-stabilised Ag NPs of 20, 60, and 100 nm diameter were aged for a week in a climatic chamber under controlled temperature (40 °C) and irradiation (1.44 W m−2 at 420 nm). The suspensions were analysed by asymmetric flow field flow fractionation – inductively coupled plasma mass spectrometry (AF4-ICP-MS), dynamic light scattering (DLS) and transmission electron microscopy (TEM). The AF4-ICP-MS monitoring showed that only a small fraction (10 % at most) of the primary 20 nm particles are converted into multi-faceted particles. Larger particles undergo shape modifications correlated with dissolution (60 nm Ag NPs) and aggregation (100 nm Ag NPs) processes. Silicate structures – supposedly originating from the glassware degradation – stabilise the primary particles. The occurrence of smaller Ag seeds, also associated with silicates, was revealed and quantified by AF4-ICP-MS and confirmed by TEM. The physical fractionation of the particles according to their size provided by AF4, together with the quantitative analysis provided by ICP-MS, helped to determine the role of size in the fate of silver nanoparticles under sunlight exposure.
Caffeine increases parasympathetic reactivation without altering resting and exercise cardiac parasympathetic modulation: A balanced placebo design
Authors: da Silva Rolim Paloma , da Costa Matos Raquel Adjafre , Von Koenig Soares Edgard de Melo Keene , Molina Guilherme Eckhardt , da Cruz Carlos Janssen Gomes
Published: October 2018

The sympathicotonic effect of caffeine is strongly evidenced in the literature. However, the effects of caffeine or caffeine expectancy on the cardiac parasympathetic modulation remain obscure. Thus, the aim of this study was to investigate the effects of caffeine consumption and expectancy of caffeine consumption on the cardiac parasympathetic modulation under different stress conditions. Twenty‐one physically active men (22.3 ± 2.9 years, 25.2 ± 2.7 kg/m2) consumed ∼3 mg/kg of caffeine received as caffeine, caffeine as placebo, placebo as placebo and placebo as caffeine. Parasympathetic modulation was assessed by heart rate variability (HRV‐Poincaré SD1 index) at supine and orthostatic positions, during a submaximal exercise (HRV threshold‐HRVT) and during each 60 seconds (s) within 300 s of post‐exercise active recovery. A factorial ANOVA for repeated measures (p < 0.05) was used to assess the effect of caffeine, expectancy and resting time after caffeine intake on the HRV. No significant effect of caffeine or expectancy was observed on the SD1 value at supine or standing positions (p = 0.47–0.53; p = 0.57–0.31, respectively), despite an increase in this variable after resting periods in both positions (p < 0.001). During exercise, caffeine and expectancy do not alter the HRVT (p = 0.51–0.39). However, higher SD1 values were observed after caffeine administration from 60 to 300 s post‐exercise recovery (p = 0.01–0.05) but not for the effects of expectancy (p = 0.19–0.94). We concluded that low doses of caffeine or expectancy do not alter the resting cardiac parasympathetic modulation or HRVT. However, caffeine, but not expectancy, increases parasympathetic reactivation after a submaximal exercise test in young men.
Genetic and epigenetic determinants establish a continuum of Hsf1 occupancy and activity across the yeast genome
Authors: Pincus David , Anandhakumar Jayamani , Thiru Prathapan , Guertin Michael J. , Erkine Alexander M. , Gross David S.
Published: October 2018

Heat shock factor 1 is the master transcriptional regulator of molecular chaperones and binds to the same cis-acting heat shock element (HSE) across the eukaryotic lineage. In budding yeast, Hsf1 drives the transcription of ∼20 genes essential to maintain proteostasis under basal conditions, yet its specific targets and extent of inducible binding during heat shock remain unclear. Here we combine Hsf1 chromatin immunoprecipitation sequencing (seq), nascent RNA-seq, and Hsf1 nuclear depletion to quantify Hsf1 binding and transcription across the yeast genome. We find that Hsf1 binds 74 loci during acute heat shock, and these are linked to 46 genes with strong Hsf1-dependent expression. Notably, Hsf1’s induced DNA binding leads to a disproportionate (∼7.5-fold) increase in nascent transcription. Promoters with high basal Hsf1 occupancy have nucleosome-depleted regions due to the presence of “pioneer factors.” These accessible sites are likely critical for Hsf1 occupancy as the activator is incapable of binding HSEs within a stably positioned, reconstituted nucleosome. In response to heat shock, however, Hsf1 accesses nucleosomal sites and promotes chromatin disassembly in concert with the Remodels Structure of Chromatin (RSC) complex. Our data suggest that the interplay between nucleosome positioning, HSE strength, and active Hsf1 levels allows cells to precisely tune expression of the proteostasis network.
Preferences versus the Environment: How Do School Fruit and Vegetable Programs Affect Children's Fresh Produce Consumption?
Authors: Staudigel Matthias , Lingl Christoph , Roosen Jutta
Published: October 2018

We assess the effects of the European Union's School Fruit and Vegetables Scheme (SFVS) on reported consumption frequencies and revealed preferences for fruit and vegetables among schoolchildren. Estimated treatment effects based on double‐difference models indicate that the SFVS raised children's fruit and vegetable consumption frequency by 30% to 50%. However, the results from actual choice data show that children exposed to the program had a decreased probability of choosing apple slices over cookies. Our findings suggest that the program increased fruit and vegetable consumption because of increased availability, exposure, and awareness rather than actual preference changes.
Technology Spillovers and Land Use Change: Empirical Evidence from Global Agriculture
Authors: Villoria Nelson B.
Published: October 2018

We estimate the effects of agricultural technological progress on cropland expansion at various geographical resolutions, from the country level to the world as a whole, while formally accounting for the international interdependence of national supply responses. Evidence for these effects has thus far been scant, contributing to polarized perceptions about the potential for improving agricultural technologies as a means to slow down deforestation. We find that, in most countries of the world, growth in total factor productivity (TFP) is either uncorrelated or is positively associated with cropland expansion. Yet worldwide TFP growth have been an important source of global land savings. The divergence between the country‐level and the global results is explained by the changes in production patterns as countries interact in international markets. Our preferred point estimate of the elasticity of global cropland to global TFP growth is ‐0.34. Moreover, we estimate that satisfying food demand from 1991 to 2010 without observed TFP growth would have necessitated an additional 173 million hectares, or close to 10% of the area covered by tropical rain forests.
Wait, There’s a Baby in this Bath Water! Update on Quantitative and Qualitative Cut-Offs for Rey 15-Item Recall and Recognition
Authors: Poynter Kellie , Boone Kyle Brauer , Ermshar Annette , Miora Deborah , Cottingham Maria , Victor Tara L , Ziegler Elizabeth , Zeller Michelle A , Wright Matthew
Published: October 2018

Objective

Evaluate the effectiveness of Rey 15-item plus recognition data in a large neuropsychological sample.

Method

Rey 15-item plus recognition scores were compared in credible (n = 138) and noncredible (n = 353) neuropsychology referrals.

Results

Noncredible patients scored significantly worse than credible patients on all Rey 15-item plus recognition scores. When cut-offs were selected to maintain at least 89.9% specificity, cut-offs could be made more stringent, with the highest sensitivity found for recognition correct (cut-off ≤11; 62.6% sensitivity) and the combination score (recall + recognition – false positives; cut-off ≤22; 60.6% sensitivity), followed by recall correct (cut-off ≤11; 49.3% sensitivity), and recognition false positive errors (≥3; 17.9% sensitivity). A cut-off of ≥4 applied to a summed qualitative error score for the recall trial resulted in 19.4% sensitivity. Approximately 10% of credible subjects failed either recall correct or recognition correct, whereas two-thirds of noncredible patients (67.7%) showed this pattern. Thirteen percent of credible patients failed either recall correct, recognition correct, or the recall qualitative error score, whereas nearly 70% of noncredible patients failed at least one of the three. Some individual qualitative recognition errors had low false positive rates (<2%) indicating that their presence was virtually pathognomonic for noncredible performance. Older age (>50) and IQ < 80 were associated with increased false positive rates in credible patients.

Conclusions

Data on a larger sample than that available in the 2002 validation study show that Rey 15-item plus recognition cut-offs can be made more stringent, and thereby detect up to 70% of noncredible test takers, but the test should be used cautiously in older individuals and in individuals with lowered IQ.
The other office
Authors: Toll Elizabeth T
Published: October 2018

Across recent decades, profound changes in the practice of medicine have been accompanied by parallel developments in the daily mental efforts of medical professionals. Using visual metaphors and hand-drawn illustrations, the author explores the evolution of one physician’s brain over the past 25 years. At the completion of training, the patient-practitioner relationship, medical knowledge, and care decisions dominated clinician thought, time, and effort. During the 1990’s, the growing constraints of third-party payers and government regulations presented new challenges to delivering relationship-based care. Over the past decade, the electronic health record (EHR) has added further cognitive complexity, disrupted human relationships, and contributed significantly to the current epidemic of clinician burnout. Solutions to these challenges include rethinking education, documentation, professional standards, institutional barriers, and regulatory mandates. It is important to pursue all solutions with the underlying premise of protecting healing relationships as the foundation of clinical care.
Physician stress and burnout: the impact of health information technology
Authors: Gardner Rebekah L , Cooper Emily , Haskell Jacqueline , Harris Daniel A , Poplau Sara , Kroth Philip J , Linzer Mark
Published: October 2018

Objective

To quantify how stress related to use of health information technology (HIT) predicts burnout among physicians.

Methods

All 4197 practicing physicians in Rhode Island were surveyed in 2017 on their HIT use. Our main outcome was self-reported burnout. The presence of HIT-related stress was defined by report of at least 1 of the following: poor/marginal time for documentation, moderately high/excessive time spent on the electronic health record (EHR) at home, and agreement that using an EHR adds to daily frustration. We used logistic regression to assess the association between each HIT-related stress measure and burnout, adjusting for respondent demographics, practice characteristics, and the other stress measures.

Results

Of the 1792 physician respondents (43% response rate), 26% reported burnout. Among EHR users (91%), 70% reported HIT-related stress, with the highest prevalence in primary care-oriented specialties. After adjustment, physicians reporting poor/marginal time for documentation had 2.8 times the odds of burnout (95% CI: 2.0–4.1; P < .0001), compared to those reporting sufficient time. Physicians reporting moderately high/excessive time on EHRs at home had 1.9 times the odds of burnout (95% CI: 1.4–2.8; P < .0001), compared to those with minimal/no EHR use at home. Those who agreed that EHRs add to their daily frustration had 2.4 times the odds of burnout (95% CI: 1.6–3.7; P < .0001), compared to those who disagreed.

Conclusion

HIT-related stress is measurable, common (about 70% among respondents), specialty-related, and independently predictive of burnout symptoms. Identifying HIT-specific factors associated with burnout may guide healthcare organizations seeking to measure and remediate burnout among their physicians and staff.
The Keisler–Shelah theorem for $\mathsf{QmbC}$ through semantical atomization
Authors: Ferguson Thomas Macaulay
Published: October 2018

In this paper, we consider some contributions to the model theory of the logic of formal inconsistency $\mathsf{QmbC}$ as a reply to Walter Carnielli, Marcelo Coniglio, Rodrigo Podiacki and Tarcísio Rodrigues’ call for a ‘wider model theory.’ This call demands that we align the practices and techniques of model theory for logics of formal inconsistency (LFIs) as closely as possible with those employed in classical model theory. The key result is a proof that the Keisler–Shelah isomorphism theorem holds for $\mathsf{QmbC}$, i.e. that the strong elementary equivalence of two $\mathsf{QmbC}$ models $\mathfrak{A}$ and $\mathfrak{B}$ is equivalent to them having strongly isomorphic ultrapowers. As intermediate steps, we introduce some notions of model-theoretic equivalence between $\mathsf{QmbC}$ models, explicitly prove Łoś’ theorem and introduce a useful technique of model-theoretic ‘atomization’ in which the satisfaction sets of non-deterministically evaluated formulae are associated with new predicates. Finally, we consider some of the extensions of $\mathsf{QmbC}$, explicitly showing that Keisler–Shelah holds for $\mathsf{QCi}$ and suggesting that it holds of extensions like $\mathsf{QCila}$ and $\mathsf{QCia}$ as well.
Effects of a Government-Academic Partnership: Has the NSF-CENSUS Bureau Research Network Helped Improve the US Statistical System?
Authors: Weinberg Daniel H , Abowd John M , Belli Robert F , Cressie Noel , Folch David C , Holan Scott H , Levenstein Margaret C , Olson Kristen M , Reiter Jerome P , Shapiro Matthew D , Smyth Jolene D , Soh Leen-Kiat , Spencer Bruce D , Spielman Seth E , Vilhuber Lars , Wikle Christopher K
Published: October 2018

The National Science Foundation-Census Bureau Research Network (NCRN) was established in 2011 to create interdisciplinary research nodes on methodological questions of interest and significance to the broader research community and to the Federal Statistical System (FSS), particularly to the Census Bureau. The activities to date have covered both fundamental and applied statistical research and have focused at least in part on the training of current and future generations of researchers in skills of relevance to surveys and alternative measurement of economic units, households, and persons. This article focuses on some of the key research findings of the eight nodes, organized into six topics: (1) improving census and survey data-quality and data collection methods; (2) using alternative sources of data; (3) protecting privacy and confidentiality by improving disclosure avoidance; (4) using spatial and spatio-temporal statistical modeling to improve estimates; (5) assessing data cost and data-quality tradeoffs; and (6) combining information from multiple sources. The article concludes with an evaluation of the ability of the FSS to apply the NCRN’s research outcomes, suggests some next steps, and discusses the implications of this research-network model for future federal government research initiatives.