bluuebunny/crossref_metadata_2025 huggingface dataset:
Time resolved photoluminescence studies of degradation in GaInP/GaAs/Ge solar cells after 1MeV electron irradiation
Authors: Guo Hongliang , Wu Yiyong , Xiao Jingdong , Guo Bin , Sun Qiang , Yu Hui
Published: August 2018

Time resolved photoluminescence (TRPL) is a powerful method to character the behaviors of carriers as it has high time resolution that could reflect the reactions of carriers within nanoseconds. For solar cells, minority carrier lifetime is the most important parameter. TRPL has been used to measure the lifetime for uniform materials. However, for homojunction solar cells, doping distribution and carrier drift make the spectroscopy analysis much difficult. Thus one dimension numerical calculations are used to study the time-dependent photoluminescence (TRPL) decay of GaAs sub-cell in GaInP/GaAs/Ge solar cells. Calculation shows that both lifetime of minorities and light intensities could determine the line shape of TRPL. The bimolecular recombination under high injection modifies the curve from single-exponential to non-single-exponential one. For TRPL of homojunction solar cell, the photoluminescence decay process is not synchronized in all parts, and the decay is fast in emitter but slower in base regions. To get the lifetimes of minority carriers after 1MeV electron irradiation, carrier generation parameter G0 should be fitted by numerical method firstly. The damage factor Kτ=4.8×10-15 cm2/ns is fitted from TRPL results. Photoluminescence spectra (PL) are also used to get Kτ=5.5×10-15 cm2/ns which is similar with the value obtained from TRPL.
Solution-processed stacked TiO2 and Al2O3 dielectric layers for high mobility thin film transistor
Authors: Jiang Shu , Yang Xiang , Zhang Jianhua , Li Xifeng
Published: August 2018

In this paper, a TiO2/Al2O3/TiO2/Al2O3/TiO2 (TATAT) stacked structure was developed as a gate dielectric for amorphous ZnSnO (ZTO) thin-film transistor (TFT) applications. The TATAT insulator has a relative permittivity and leakage current density of 11 and 4.44 × 10-7 A/cm2 at 1 MV/cm, respectively. As compared with the AlTiO (ATO) compound dielectric, the ZTO TFT device with a TATAT stacked dielectric exhibited a lower threshold voltage of 0.56 V, a higher Ion/Ioff current ratio of 1.2x 10-8, a larger field-effect mobility of 86.6 cm2/Vs, and a smaller subthreshold swing of 0.2 V/decade. Furthermore, the positive shift of threshold voltage is less than 0.15 V under positive bias stress. The results suggest that stack TATAT films is a promising gate dielectric for solution-processed TFT devices with high mobility and stability.
Dimer model: Full asymptotic expansion of the partition function
Authors: Bleher Pavel , Elwood Brad , Petrović Dražen
Published: August 2018

We give a complete rigorous proof of the full asymptotic expansion of the partition function of the dimer model on a square lattice on a torus for general weights zh, zv of the dimer model and arbitrary dimensions of the lattice m, n. We assume m is even and we show that the asymptotic expansion depends on the parity of n. We review and extend the results of Ivashkevich et al. [J. Phys. A: Math. Gen. 35, 5543 (2002)] on the full asymptotic expansion of the partition function of the dimer model, and we give a rigorous estimate of the error term in the asymptotic expansion of the partition function.
Pointwise convergence of Birkhoff averages for global observables
Authors: Lenci Marco , Munday Sara
Published: August 2018

It is well-known that a strict analogue of the Birkhoff Ergodic Theorem in infinite ergodic theory is trivial; it states that for any infinite-measure-preserving ergodic system, the Birkhoff average of every integrable function is almost everywhere zero. Nor does a different rescaling of the Birkhoff sum that leads to a non-degenerate pointwise limit exist. In this paper, we give a version of Birkhoff’s theorem for conservative, ergodic, infinite-measure-preserving dynamical systems where instead of integrable functions we use certain elements of L∞, which we generically call global observables. Our main theorem applies to general systems but requires a hypothesis of “approximate partial averaging” on the observables. The idea behind the result, however, applies to more general situations, as we show with an example. Finally, by means of counterexamples and numerical simulations, we discuss the question of finding the optimal class of observables for which a Birkhoff theorem holds for infinite-measure-preserving systems.
Investigating exciton structure and dynamics in colloidal CdSe quantum dots with two-dimensional electronic spectroscopy
Authors: Seiler H. , Palato S. , Kambhampati P.
Published: August 2018

Two-Dimensional Electronic Spectroscopy (2DES) is performed on CdSe colloidal quantum dots. These experiments reveal new observations on exciton structure and dynamics in quantum dots, expanding upon prior transient absorption measurements of excitonics in these systems. The 2DES method enables the separation of line broadening mechanisms, thereby better revealing the excitonic lineshapes and biexcitonic interactions. 2DES enables more information rich spectral probing of coherent phonons and their coupling to excitons. The data show spectral modulations and drifts, with differences based upon whether one monitors the excitation energy (E1) or emission energy (E3). These measurements reveal both homogeneous and inhomogeneous broadenings, as well as static and dynamic line broadening. The longitudinal optical phonon modulates the dynamic absorption spectrum both in energy and linewidth. These experiments enable measurement of hot exciton cooling with improved resolution in energy and time. These 2DES results are consistent with prior excitonic state-resolved transient absorption measurements, albeit with the addition of contributions due to coherent phonons. Finally these 2DES experiments enable disentangling of coupling versus relaxation contributions to the signals, further offering a test of electronic structure theory.
A novel spatial-distribution-function of electron beam-induced vapor plume for analyzing EBPVD thickness
Authors: Ho Ching-Yen , Chen Bor-Chyuan , Xiong Chang-Wei , Fan Si-Li , Wan Song-Feng , Li Long-Gen , Shu Yu-Feng , Yu Xiao-Qiong
Published: August 2018

This paper investigates the thickness distribution of substrate coating of electron-beam physical vapor deposition (EBPVD) using a novel spatial-distribution-function, which is different from the empirical modified law. The Knudsen cosine law and empirical modified law were usually used for predicting coating thickness in EBPVD. However, these two laws obtained from experiments and geometric concepts cannot provide the elucidation for physical point of view and all-inclusive spatial-distribution-functions. Therefore, instead of the spatial-distribution-functions based on the Knudsen cosine law for low evaporation rates and empirical modified law for the higher evaporation rates, the spatial distribution function based on the mass diffusion theory is proposed to analyze the coating thickness of EB-induced physical vapor deposition. The coating thicknesses predicted by these spatial-distribution-functions are compared with the data measured by the published papers. The results reveal that the coating thicknesses predicted by the spatial distribution function of the diffusion theory are more consistent with the measured data than these obtained from the spatial distribution function of the empirical modified law. The spatial distribution function proposed by this study is validated by correctly predicting the measured coating thickness for EBPVD of titanium and aluminum.
Introducing a novel design in the realm of box type solar cookers: An experimental study
Authors: Zafar Hafiz Abdullah , Khan Muhammad Yasin , Badar Abdul Waheed , Tariq Rasikh , Butt Fahad Sarfraz
Published: August 2018

This paper introduces a novel design of a double glazed box type solar cooker having an L-shaped absorber plate with one internal (bottom) and two external plane reflectors. A series of experiments were performed to access the cooker's thermal performance at the location of Taxila (33.74°N, 72.80°E) in Pakistan during the year 2017. The cooker's performance is evaluated in terms of maximum absorber plate temperature and other thermal performance indicators like first and second figures of merits (F1 and F2), parameter index, energy efficiency, and utilizable efficiency. The experimentally obtained values of all the performance indicators are found to be in the recommended ranges specified in the literature. An increment of about 30% in the absorber plate temperature is estimated for the case of the proposed L-shaped absorber plate along with an internal (bottom) reflector as compared to the case of no internal reflector and a conventional horizontal absorber plate. The first figure of merit of the proposed cooker is estimated to be 0.12, thus classifying it in grade A category. Furthermore, the solar cooker is manufactured at a nominal cost of ∼130 USD, making it a competitive product in the market.
Ultrafast pulsed magnetic fields generated by a femtosecond laser
Authors: Zhu Baojun , Zhang Zhe , Jiang Weiman , Wang Jinguang , Zhu Changqing , Tan Junhao , Zhang Yihang , He Yuhang , Li Yifei , Ma Jinglong , Li Yutong
Published: August 2018

An ultrafast pulsed magnetic field from a two-loop solenoid is generated by a femtosecond (fs) laser. High temporal resolution is needed to measure the magnetic field. We describe an improved Faraday-rotation measurement to evaluate the evolution of the magnetic field with a resolution of ∼3.3 picoseconds (ps) in a single shot, with an uncompressed chirped pulse from a Ti:sapphire laser as the optical probe. A magnetic field of 0.52 T with a rise time of 20.8 ps has been measured with this chirped Faraday probe. In addition, we demonstrate the magnetic field strength driven by the femtosecond laser can be modified by adjusting the focal spot size.
Exergetic optimization and comparison of combined gas turbine supercritical CO2 power cycles
Authors: Ayub Abubakr , Sheikh Nadeem Ahmed , Tariq Rasikh , Khan Muhammad Mahabat , Invernizzi Costante Mario
Published: August 2018

For developing a sustainable power system, the key is to maximize the use of available resources with a minimal impact on the environment. One technique for achieving this is exhaust heat recovery. In this paper, three gas turbine exhaust heat recovery supercritical carbon dioxide combined power cycles are presented. They are combined gas turbine-recompression cycle, combined gas turbine-preheating cycle, and combined gas turbine-simple regenerative cycle. For all the cycles, thermodynamic models are developed and the influence of varying mass flow rates, compression ratio, and mass split/recompression percentages in different components of all three cycles are investigated. Using genetic algorithm, exergetic optimization is done to find the optimal configuration for each cycle. The reduction in CO2 emissions in presented cycles against fossil fuel power cycles is also assessed. Additionally, a comparison with a simple gas turbine (SGT) and an air bottoming combined cycle (ABC) is presented. The results indicate that owing to exhaust exergy recovery, there is a significant improvement in the energetic and exergetic performance of combined gas turbine-supercritical CO2 power cycles compared to that of SGT and ABC. The sum of exergy destruction and exergy loss in the combined cycles is lower as compared to the sum in SGT. The reduction in losses compared to SGT is 22.89% in the case of the combined gas turbine recompression cycle and 35.8% in the case of the combined gas turbine preheating cycle (CGTPHC). Moreover, the energetic and exergetic performances of the bottoming supercritical CO2 recompression cycles (BRECs) are better than those of the bottoming supercritical CO2 preheating cycle owing to lower exergy destruction in the components of BREC. As a result of comparative analysis based on the exergetic performance and environmental impact, the CGTPHC is selected as an appropriate option for gas turbine exhaust exergy recovery.
Active spectroscopy measurements of the deuterium temperature, rotation, and density from the core to scrape off layer on the DIII-D tokamak (invited)
Authors: Haskey S. R. , Grierson B. A. , Stagner L. , Chrystal C. , Ashourvan A. , Bortolon A. , Boyer M. D. , Burrell K. H. , Collins C. , Groebner R. J. , Kaplan D. H. , Pablant N. A.
Published: August 2018

Main-ion charge exchange recombination spectroscopy (MICER) uses the neutral beam induced Dα spectrum to measure the local deuterium ion (D+) temperature, rotation, and density, as well as parameters related to the neutral beams, fast ions, and magnetic field. An edge MICER system consisting of 16 densely packed chords was recently installed on DIII-D, extending the MICER technique from the core to the pedestal and steep gradient region of H-mode plasmas where the D+ and commonly measured impurity ion properties can differ significantly. A combination of iterative collisional radiative modeling techniques and greatly accelerated spectral fitting allowed the extension of this diagnostic technique to the plasma edge where the steep gradients introduce significant diagnostic challenges. The importance of including the fast ion Dα emission in the fit to the spectrum for the edge system is investigated showing that it is typically not important except for cases which can have significant fast ion fractions near the plasma edge such as QH-mode. Example profiles from an Ohmic L-mode and a high power ITER baseline case show large differences in the toroidal rotation of the two species near the separatrix including a strong co-current D+ edge rotation. The measurements and analysis demonstrate the state of the art in active spectroscopy and integrated modeling for diagnosing fusion plasmas and the importance of direct main ion measurements.
Development and characterization of liquid argon and methane microjets for high-rep-rate laser-plasma experiments
Authors: Kim Jongjin B. , Schoenwaelder Christopher , Glenzer Siegfried H.
Published: August 2018

A cryogenic microjet system has been used for delivering micron-scale continuous liquid hydrogen targets for laser-plasma experiments. This technique has been extended to higher-Z, higher boiling-point gases, including argon and methane. High-resolution shadowgraphy has been used to characterize the jet’s morphology and pointing stability. A split and delay illumination source has also been developed for direct measurement of jet speeds without relying on assumptions of fluid flow conditions. Under typical conditions, the argon jets freeze solid due to evaporative cooling, but the methane jets remain liquid and break up to a droplet stream. A piezo driver is used to ensure the droplets are of uniform size. This jet has enabled the investigation of methane in planetary core conditions with high-rep-rate laser heating and x-ray laser probing.
Dual-pass upgrade to the Thomson scattering diagnostic on the Prototype-Material Plasma Exposure eXperiment (Proto-MPEX)
Authors: Kafle N. , Biewer T. M. , Donovan D. C.
Published: August 2018

The Thomson scattering (TS) diagnostic on the Prototype-Material Plasma Exposure eXperiment has been upgraded to measure electron temperature (Te) and density (ne) simultaneously at two axial locations. After the first pass through the vacuum vessel, the exiting laser beamline is re-collimated in the atmosphere and rerouted into the vacuum vessel for the second pass. The upgrade will help diagnose axial Te and ne gradients between the “central chamber” and the target region which are located 1 m and 2.5 m, respectively, downstream from the Helicon radio-frequency source. The TS measurements have given Te ≈ 4–15 eV and ne ≈ 2–4 × 1019 m−3 at the central chamber and Te ≈ 1–2 eV and ne ≈ 1–2 × 1019 m−3 at the target region. The upgrade also increases the number of sampling points at the target region from 3 fibers to 5 fibers, measuring 3 cm radially across the plasma column, and 25 fibers in the central chamber, radially spanning 8 cm. The intensified CCD camera is double triggered for each laser pulse in order to measure (1) the TS and laser stray light and (2) the plasma background light that contains nuisance emission lines and bremsstrahlung. Subtracting the background light from the TS photons improves the temperature and density measurements. Details of the diagnostic setup, axial and radial measurements, and areas for further optimization are discussed.
Comparison of single particle dynamics at the center and on the surface of equilibrium glassy films
Authors: Kuon Nicholas , Flenner Elijah , Szamel Grzegorz
Published: August 2018

Glasses prepared by vapor depositing molecules onto a properly prepared substrate can have enhanced kinetic stability when compared with glasses prepared by cooling from the liquid state. The enhanced stability is due to the high mobility of particles at the surface, which allows them to find lower energy configurations than for liquid cooled glasses. Here we use molecular dynamics simulations to examine the temperature dependence of the single particle dynamics in the bulk of the film and at the surface of the film. First, we examine the temperature dependence of the self-intermediate scattering functions for particles in the bulk and at the surface. We then examine the temperature dependence of the probability of the logarithm of single particle displacements for bulk and surface particles. Both bulk and surface particle displacements indicate populations of slow and fast particles, i.e., heterogeneous dynamics. We find that the temperature dependence of the surface dynamics mirrors the bulk despite being several orders of magnitude faster.
Millimeter wave (220 GHz–330 GHz) characterizations of carbon nanotube films
Authors: Fu Hai-Peng , Yang Chuang , Ma Kai-Xue , Huang Hui , Ma Jian-Guo , Li Ya-Li , Kang Yan-Ru , Ma Jun-Xiao , Huang Xiang-Dong
Published: August 2018

A carbon nanotube (CNT) film on a substrate is characterized at millimeter waves (220 GHz−330 GHz) by metal rectangular waveguide scattering parameters (S-parameters) measurements. The anisotropy of the CNT film is investigated for different orientations of the on-substrate CNT film. The standard Nicolson–Ross–Weir (NRW) approach has been adopted to extract the complex permittivity (εr=ε′-jε″) and permeability (μr=μ′-jμ″) of the on-substrate CNT film from the measured S-parameters. The effective medium theory is then applied to remove the impact of the substrate and characterize the intrinsic CNT film. The observed frequency independent and anisotropic behaviors of the CNT film are very promising indicators that this material could be invaluable for a range of millimeter-wave applications.
Investigating unipolar switching in Niobium oxide resistive switches: Correlating quantized conductance and mechanism
Authors: Deswal Sweety , Kumar Ashok , Kumar Ajeet
Published: August 2018

Memory devices based on resistive switching (RS) have not been fully realised due to lack of understanding of the underlying switching mechanisms. Nature of ion transport responsible for switching and growth of conducting filament in transition metal oxide based RS devices is still in debate. Here, we investigated the mechanism in Niobium oxide based RS devices, which shows unipolar switching with high ON/OFF ratio, good endurance cycles and high retention times. We controlled the boundary conditions between low-conductance insulating and a high-conductance metallic state where conducting filament (CF) can form atomic point contact and exhibit quantized conductance behaviour. Based on the statistics generated from quantized steps data, we demonstrated that the CF is growing atom by atom with the applied voltage sweeps. We also observed stable quantized states, which can be utilized in multistate switching.
Bond selective dissociation of methane (CH3D) on the steps and terraces of Pt(211)
Authors: Gutiérrez-González Ana , Crim F. Fleming , Beck Rainer D.
Published: August 2018

The dissociative chemisorption of singly deuterated methane (CH3D) has been studied on the steps and terraces of a Pt(211) surface by quantum state resolved molecular beam methods. At incident translational energy (Et) below 50 kJ/mol, CH3D dissociates only on the more reactive steps of Pt(211), where both C–H and C–D cleavage products CH2D(ads) and CH3(ads) can be detected by reflection absorption infrared spectroscopy. Vibrational excitation of a slow beam of CH3D (Et = 10 kJ/mol), prepared with one quantum of antisymmetric C–H stretch excitation by infrared laser pumping, allows for fully bond- and site-selective dissociation forming exclusively CH2D(ads) on the step sites. At higher kinetic energies (Et > 30 kJ/mol), bond selective dissociation by C–H bond cleavage is observed on the terrace sites for stretch excited CH3D (ν4) while on the steps, the C–H/C–D cleavage branching ratio approaches the statistical 3/1 limit. Finally, at Et > 60 kJ/mol, both C–H and C–D cleavages are observed on both step and terrace sites of Pt(211). Our experiments show how careful control of incident translational and vibrational energy can be used for site and bond selective dissociation of methane on a catalytically active Pt surface.
Monochromatic mammography using scanning multilayer X-ray mirrors
Authors: Windt David L.
Published: August 2018

A prototype system for breast imaging using monochromatic X-rays has been developed using a scanning multilayer X-ray mirror in combination with a conventional mammography tube and an imaging detector. The X-ray mirror produces a monochromatic fan beam tuned near 19 keV, with an energy bandpass of approximately 1.5 keV. Rotating the mirror about the tube’s focal spot in synchronization with the X-ray generator and detector enables the acquisition of monochromatic X-ray images over large areas. The X-ray mirror also can be rotated completely out of the beam so that conventional polychromatic images can be acquired using a K-edge filter, facilitating direct comparison between the two modes of operation. The system was used to image synthetic, tissue-equivalent breast phantoms in order to experimentally quantify the improvements in image quality and dose that can be realized using monochromatic radiation. Nine custom phantoms spanning a range of thicknesses and glandular/adipose ratios, each containing both glandular- and calcification-equivalent features, were used to measure contrast and signal-difference-to-noise ratio (SDNR). Mean glandular dose (MGD) was computed from measured entrance exposure, and a figure-of-merit (FOM) was computed as FOM = SDNR2/MGD in each case. Monochromatic MGD ranges from 0.606 to 0.134 of polychromatic MGD for images having comparable glandular SDNR, depending on breast thickness and glandularity; relative monochromatic dose decreases with increasing glandularity for all thicknesses. Monochromatic FOM values are higher than the corresponding polychromatic FOM values in all but one case. Additionally, the monochromatic contrast for glandular features is higher than the polychromatic contrast in all but one case as well. These results represent important steps toward the realization of clinically practical monochromatic X-ray breast imaging systems having lower dose and better image quality, including those for digital mammography, digital breast tomosynthesis, contrast-enhanced spectral mammography and other modalities, for safer, more accurate breast cancer detection, diagnosis and staging.
The influence of anisotropic voxel caused by field of view setting on the accuracy of three-dimensional reconstruction of bone geometric models
Authors: Liu Yaming , Li Ruining , Fan Yuxuan , Antonijević Ðorđe , Milenković Petar , Li Zhiyu , Djuric Marija , Fan Yifang
Published: August 2018

The finite element method is playing an increasingly important role in osteoporosis screening. An accurate bone geometric model, a prerequisite for the finite element analysis, is affected by voxels. Isotropic voxel has advantages in three-dimensional reconstruction, but field of view setting usually results in anisotropic voxels. The main goal of this study was to investigate the influence of anisotropic voxel on the accuracy of three-dimensional reconstruction of bone geometric models. Sixty metatarsal bones were scanned twice with an interval of 18 months with different fields of view. We reconstructed these metatarsals and compared them. The results showed that there was no significant difference in volume, surface, length, width and height and two principal moments of inertia, indicating that anisotropic voxel caused by field of view setting has a neglectable effect on the three-dimensional reconstruction of bone geometric models, and that using finite element method based on bone geometric model reconstructed by anisotropic voxel to predict bone strength is reliable.
Directional acoustic transmission based on metamaterials
Authors: Tang Shuai , Han Jianning , Wen Tingdun
Published: August 2018

To explore the simple low-loss operation of directional acoustic transmission technology, the propagation of acoustic waves in resonant phononic crystals was studied, and a transmission model based on acoustic metamaterials was constructed. Using the local resonance characteristics between acoustic waves and original cells, the multi-directional transmission of acoustic waves was modeled in the COMSOL software. It was found that acoustic waves generated by a point source are refocused into another point source after passing through the transmission model, and that the transmission loss is small. Under the control of this model, the effect of point-source propagation in various directions was achieved. The acoustic field characteristics of the model samples were also tested to verify the feasibility of the model structure, providing a new direction for applications such as underwater acoustic communication and detection.
Effects of Al2O3 gate insulator on the instability of amorphous indium-gallium zinc oxide thin film transistors
Authors: Kim Yu-Mi , Lee Ga-Won
Published: August 2018

This study analyzes bottom-gated amorphous indium-gallium zinc oxide (a-IGZO) thin film transistors (TFTs) with different gate insulators of Si3N4 and Si3N4/Al2O3. The aim is to investigate the effect of Al2O3 on the instability of IGZO TFTs with respect to native point defects. Although the DC properties of Si3N4/Al2O3 devices are inferior to those of Si3N4 devices, the bias stress-induced hump is not observed in Si3N4/Al2O3 devices. From calculations of the oxygen exchange kinetics between the insulator and IGZO, it appears that more oxygen atoms diffuse from Al2O3 to the IGZO than from the Si3N4. This oxygen diffusion is confirmed by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Auger electron spectroscopy depth-profiling analysis. In addition, more oxygen interstitials with fewer zinc interstitials are detected at the IGZO interface with Al2O3. From the results, it can be concluded that the distribution of native defects in Al2O3 devices reduces the instability of IGZO TFTs.
Detonation on a tabletop: Nitromethane with high time and space resolution
Authors: Bhowmick Mithun , Nissen Erin J. , Dlott Dana D.
Published: August 2018

Nitromethane (NM), a flammable liquid, has been a model system for the shock-to-detonation transition in homogeneous condensed-phase explosives for over 50 years, but we do not understand the fast processes at the molecular scale in the detonation front at the molecular scale. That is largely because prior studies triggered detonations in bomb-sized charges with input shock durations and times-to detonation that were typically microseconds, which made it impossible to observe the faster processes in real time. We studied NM shocked with 4 ns duration input pulses using a tabletop apparatus with laser-launched flyer plates and arrays of tiny disposable optical cuvettes, where the pressure and temperature were probed in real time (1 ns) with photon Doppler velocimetry, optical pyrometry, and high-speed video. Using a 4 ns shock with an input pressure close to the von Neumann spike pressure of 19 GPa, we achieved the minimum time-to-detonation, about 12 ns, where the time-to-detonation is controlled by fundamental molecular processes. We demonstrated the reproducibility of our detonations and showed that they had the same properties as in bomb-sized charges: our detonation velocity, von Neumann spike and Chapman-Jouguet pressures, temperatures, and reaction zone lengths were the same as in bomb-sized charges. Being able to trigger realistic reproducible detonations from a short pulse makes it possible to investigate molecular and fluid dynamics in the detonation by measuring transient responses in real time. We found that it took 6 ns for the temperature to reach 3430 K. The high pressure was observed at about 8 ns, when there was a volume explosion to nearly twice the von Neumann spike pressure before settling down to a steady detonation.
Transmission efficiency analysis and optimization of magnetically coupled resonant wireless power transfer system with misalignments
Authors: Gao Pengfei , Tian Zijian , Pan Tao , Wu Jun , Gui Weifeng
Published: August 2018

Magnetically coupled resonant (MCR) wireless power transfer (WPT) is a promising technology, which has been widely used in many practical applications. In the practical application environment the misalignments between the transmitting coil and the receiving coil can not be avoided, and it will cause a rapid decline in transmission efficiency. So the misalignments have limited the applications of MCR-WPT technology in many fields. The mathematical formula of transmission efficiency with angular misalignment and lateral misalignment was deduced. And the effects of angular misalignment and lateral misalignment on the transmission efficiency were researched by simulation experiments. And the changing regularity of the transmission efficiency with the change of the angular misalignment and lateral misalignment was obtained. The results show that when there is an angular misalignment between the transmitting coil and the receiving coil, the transmission efficiency can be optimized by adjusting the lateral misalignment between the coils. And when there is a lateral misalignment between the coils, the transmission efficiency can be optimized by adjusting the angular misalignment between the coils. An experimental prototype of MCR-WPT system was built, and experiments had been carried out to evaluate the accuracy of the theoretical analysis. Therefore, the study in this paper lay a theoretical foundation for the analysis of WPT in the complex environment, and also provide a useful reference for the design of WPT system.
Numerical verification of the hydrodynamic reconstruction method for contact resonance atomic force microscopy
Authors: Shihab Rafiul , Tung Ryan C.
Published: August 2018

A numerical verification of an experimental method used to estimate hydrodynamic forces in contact resonance atomic force microscopy (CR AFM) is performed. The experimental estimation technique, known as the Hydrodynamic Reconstruction Method (HRM), is verified for three distinct cantilever geometries at several vibrational eigenmodes and sample stiffnesses. The results of the analysis are discussed and recommendations for the applicable measurement range of the HRM are provided.
Magnetic properties of monolayer WSe2 doped with nonmagnetic metal and nonmetal atoms
Authors: Luo Min , Xu Yu E , Zhang Qiu Xiang
Published: August 2018

Electronic and magnetic properties of WSe2 monolayer with different nonmagnetic metal and nonmetal dopants have been studied by the DFT method. Nonmagnetic metal (Ag, Al, Li, Mg, and Na) and nonmetal (B, C, F, N, and O) dopants prefer to W and Se substitutions, respectively. Magnetism has been induced by Al doping. Then, we further have considered the effect of strain on the magnetism in Al-doped WSe2 monolayer. We have applied an isotropic strain on the system. On one hand, the magnetism disappears while the compressive strain is applied. On the other hand, the magnetism keeps stable under the tensile strain. Moreover, we also investigate the magnetic coupling in two-Al-doped WSe2 structures under the tensile strain. Interestingly, a tunable magnetic coupling has been observed. As the tensile strain increases, the magnetic coupling of two Al atoms switches from nonmagnetic (NM) to ferromagnetic (FM) due to the p-p hybridization between Al and Se atoms. These fascinating controllable magnetic properties are desired for spintronic applications.
Uniqueness of ground states for nonlinear Hartree equations
Authors: Luo Yong
Published: August 2018

We consider ground states of nonlinear Hartree equations with trapping potentials V(x), which can be described equivalently by positive minimizers of L2-critical Hartree energy functional. It is known that ground states exist if and only if the parameter a satisfies a<a*≔‖Q‖22, where Q is the unique ground state of ΔQ−Q+∫R4Q2(y)|x−y|2dyQ=0 in R4. In this paper, we prove the uniqueness of ground states as a ↗ a*, where the potential V(x) = p(x)h(x), 0<C≤p(x)≤1C, h(x) is homogeneous of degree q ≥ 2, and however H(y)=∫R4h(x+y)Q2(x)dx admits a unique and non-degenerate critical point.
Framework for better care: reconciling approaches to patient safety and quality
Authors: Johnson Andrew , Clay-Williams Robyn , Lane Paul
Published: August 2018

In September 2017, the Royal Australasian College of Medical Administrators adopted a new clinical governance framework that recognised healthcare as a complex adaptive system, and embraced the need for resilient thinking and understanding the differences between work-as-imagined by managers and work-as-done at the front line of patient care. Directors of medical services may soon be implementing the framework in health services across Australia. This perspective describes a new conceptual model that underpins the Royal Australasian College of Medical Administrators framework, and characterises the challenges faced by all healthcare professionals when trying to achieve safe care for patients in an environment of variable complexity and unpredictability.
Identification of non-mutated neoantigens presented by TAP-deficient tumors
Authors: Marijt Koen A. , Blijleven Laura , Verdegaal Els M.E. , Kester Michel G. , Kowalewski Daniel J. , Rammensee Hans-Georg , Stevanović Stefan , Heemskerk Mirjam H.M. , van der Burg Sjoerd H. , van Hall Thorbald
Published: August 2018

Most T cell–based immunotherapies of cancer depend on intact antigen presentation by HLA class I molecules (HLA-I). However, defects in the antigen-processing machinery can cause downregulation of HLA-I, rendering tumor cells resistant to CD8+ T cells. Previously, we demonstrated that a unique category of cancer antigens is selectively presented by tumor cells deficient for the peptide transporter TAP, enabling a specific attack of such tumors without causing immunopathology in mouse models. With a novel combinatorial screening approach, we now identify 16 antigens of this category in humans. These HLA-A*02:01 presented peptides do not derive from the mutanome of cancers, but are of “self” origin and therefore constitute universal neoantigens. Indeed, CD8+ T cells specific for the leader peptide of the ubiquitously expressed LRPAP1 protein recognized TAP-deficient, HLA-Ilow lymphomas, melanomas, and renal and colon carcinomas, but not healthy counterparts. In contrast to personalized mutanome-targeted therapies, these conserved neoantigens and their cognate receptors can be exploited for immune-escaped cancers across diverse histological origins.
Propofol’s paradox, explained
Authors: Sedwick Caitlin
Published: August 2018

Tandem JGP studies investigate how propofol affects voltage-gated sodium channels.
Exploring the Response of Combined Urban Sewer System to the Implementation of Green Roof
Authors: Gao Yuqin , Wang Dongdong , Schmidt A , Tang Yun
Published: August 2018

In order to find an efficient and reliable method for assessing the impact of green roofs on runoff in urban areas, IUHM-GreenRoof combination model is established via Matlab. Taking CDS-51 catchment located in Dolton, Illinois as a case, and considering different green roof coverage ratios as well as runoff conditions, the influence on the catchment outlet runoff because of the application of green roofs is analysed by running the model in two typical storms. The results show that green roofs have good water storage capacity, which can effectively decrease the catchment runoff in terms of peak discharge and volume. Moreover, the green roof coverage ratio has more influence on runoff than green roof runoff conditions.
Study on the Pin-load Distribution of Composite Joints with Protruding-head Bolts Based on Cumulative Damage
Authors: Liu Xiangdong , Zhang Huimei , Liu Na , Li Linjie
Published: August 2018

This paper presents the investigation of the pin–load distribution law of composite mechanical joints with protruding-head bolts based on the theory of composite cumulative damage. The three-dimensional finite element analysis have been carried out by using the software ANSYS for the composite plates connected with protruding-head bolts. The friction on the contact surfaces of the composite joints, and the nonlinearity of the contact state and the preload on the bolts have been considered. The effect law of cumulative damage on the pin-load distribution of multiple-bolted joints has been achieved. The results manifest that the proportion of the pin-load distribution varies with the external load and is slightly different at diverse stages of loading considering the cumulative damage of the composite materials, that pin load at both ends is greater than in the middle.
Effect of Curing Temperature on Activity Index of Silica Fume
Authors: Dai Jinpeng , Wang Qicai , Xie Chao , Xie Zhigang , Tian Xianfu , Lou Xuyu , Guo Haizhen
Published: August 2018

The compressive strength of the contrast mortars and test mortars at different curing temperatures at different ages were tested. Effect of curing temperature on the strength of the test mortars and the contrast mortars was analyzed. The relative activity index and absolute activity index of the silica fume were studied. The mercury porosimetry method was used to test the pore structure of mortar specimens, and the improving effect of silica fume on the pore structure of mortar specimens under different curing temperatures was analyzed. The results show that with the increase of age, the decrease of curing temperature will cause the strength of mortar specimens to slow down. At the 3d and 7d ages, with the decrease of curing temperature, the absolute activity value of silica fume gradually increases. After 7 days of age, with the decrease of curing temperature, the absolute activity of silica fume gradually decreases. With the increase of curing age, the relative activity of silica fume decreases at first and then increases at 20°C and 10°C. The relative activity value of silica fume under the maintenance of 5°C and -3°C increased first and then decreased gradually. The addition of silica fume in the concrete improved the internal pore structure of the specimen, and the effect of curing temperature on the specimen was consistent.
Decoupling Evolutionary Programming from Gigabit Switches in Neural Networks
Authors: Ling Hangkun
Published: August 2018

Superpages and Lamport clocks, while technical in theory, have not until recently been considered confirmed. In fact, few futurists would disagree with the understanding of voice-over-IP. We confirm that red-black trees can be made omniscient, replicated, and game-theoretic.
A locally hyperbolic 3-manifold that is not hyperbolic
Authors: Cremaschi Tommaso
Published: August 2018

We construct a locally hyperbolic 3-manifold

M
∞

M_\infty

such that

π
1

(

M
∞

)

\pi _1(M_\infty )

has no divisible subgroup. We then show that

M
∞

M_\infty

is not homeomorphic to any complete hyperbolic manifold. This answers a question of Agol.
Polynomial bases: Positivity and Schur multiplication
Authors: Searles Dominic
Published: August 2018

We establish a poset structure on combinatorial bases of multivariate polynomials defined by positive expansions and study properties common to bases in this poset. Included are the well-studied bases of Schubert polynomials, Demazure characters, and Demazure atoms; the quasi-key, fundamental, and monomial slide bases introduced in 2017 by Assaf and the author; and a new basis we introduce completing this poset structure. We show the product of a Schur polynomial and that an element of a basis in this poset expands positively in that basis; in particular, we give the first Littlewood-Richardson rule for the product of a Schur polynomial and a quasi-key polynomial. This rule simultaneously extends Haglund, Luoto, Mason, and van Willigenburg’s (2011) Littlewood-Richardson rule for quasi-Schur polynomials and refines their Littlewood-Richardson rule for Demazure characters. We also establish bijections connecting combinatorial models for these polynomials including semi-skyline fillings and quasi-key tableaux.
Cell cycle–dependent force transmission in cancer cells
Authors: Panagiotakopoulou Magdalini , Lendenmann Tobias , Pramotton Francesca Michela , Giampietro Costanza , Stefopoulos Georgios , Poulikakos Dimos , Ferrari Aldo
Published: August 2018

The generation of traction forces and their transmission to the extracellular environment supports the disseminative migration of cells from a primary tumor. In cancer cells, the periodic variation of nuclear stiffness during the cell cycle provides a functional link between efficient translocation and proliferation. However, the mechanical framework completing this picture remains unexplored. Here, the Fucci2 reporter was expressed in various human epithelial cancer cells to resolve their cell cycle phase transition. The corresponding tractions were captured by a recently developed reference-free confocal traction-force microscopy platform. The combined approach was conducive to the analysis of phase-dependent force variation at the level of individual integrin contacts. Detected forces were invariably higher in the G1 and early S phases than in the ensuing late S/G2, and locally colocalized with high levels of paxillin phosphorylation. Perturbation of paxillin phosphorylation at focal adhesions, obtained through the biochemical inhibition of focal adhesion kinase (FAK) or the transfection of nonphosphorylatable or phosphomimetic paxillin mutants, significantly diminished the force transmitted to the substrate. These data demonstrate a reproducible modulation of force transmission during the cell cycle progression of cancer cells, instrumental to their invasion of dense environments. In addition, they delineate a model in which paxillin phosphorylation supports the mechanical maturation of adhesions relaying forces to the substrate.
Microtexture and the Cell/Biomaterial Interface: A Systematic Review and Meta-Analysis of Capsular Contracture and Prosthetic Breast Implants
Authors: Shauly Orr , Gould Daniel J , Patel Ketan M
Published: August 2018

Background

The use of textured breast implants over smooth implants has been widely shown to have a lower incidence of capsular contracture. However, the impact of micropatterning techniques on the incidence of postoperative patient morbidity has not been comprehensively investigated.

Objectives

The authors sought to examine the incidence of capsular contracture, seroma, and implant rippling among the 3 major micropatterning techniques applied in the manufacturing of textured breast implants.

Methods

Literature searches of PubMed/Medline and Embase between 1995 and 2017 were performed, and 19 studies were selected for analysis. Data from each study were extracted into a form including mean age, study design, population size, mean follow-up, number of capsular contracture cases, number of seroma cases, and number of rippling cases. Meta-analysis was performed separately for studies that included capsular contracture rates for foam textured implants, imprinted textured implants, and salt-loss textured implants.

Results

The pooled rate of capsular contracture rates in primary augmentation patients was 3.80% (95% CI, 2.19-5.40) for imprinted textured implants, 4.90% (95% CI, 3.16-6.64) for foam textured implants, 5.27% (95% CI, 3.22-7.31) for salt-loss textured implants, and 15.56% (95% CI, 13.31-18.16) for smooth implants. The results of each meta-analysis were summarized on a forest plot depicting the distribution of capsular contracture rates from each study.

Conclusions

Micropatterning of prosthetic implants could drastically reduce postoperative patient morbidity given the advent of recent technologies that allow for more detailed texturing of implant surfaces.

Level of Evidence: 4
StructureProfiler: an all-in-one tool for 3D protein structure profiling
Authors: Meyder Agnes , Kampen Stefanie , Sieg Jochen , Fährrolfes Rainer , Friedrich Nils-Ole , Flachsenberg Florian , Rarey Matthias
Published: August 2018

Motivation

Three-dimensional protein structures are important starting points for elucidating protein function and applications like drug design. Computational methods in this area rely on high quality validation datasets which are usually manually assembled. Due to the increase in published structures as well as the increasing demand for specially tailored validation datasets, automatic procedures should be adopted.

Results

StructureProfiler is a new tool for automatic, objective and customizable profiling of X-ray protein structures based on the most frequently applied selection criteria currently in use to assemble benchmark datasets. As examples, four dataset configurations (Astex, Iridium, Platinum, combined), all results of the combined tests and the list of all PDB Ids passing the combined criteria set are attached in the Supplementary Material.

Availability and implementation

StructureProfiler is available as part of the ProteinsPlus web service http://proteins.plus and as standalone tool in the NAOMI ChemBio Suite. Dataset updates together with the tool can be found on http://www.zbh.uni-hamburg.de/structureprofiler.

Supplementary information

Supplementary data are available at Bioinformatics online.
The long non-coding RNA landscape of periodontal ligament stem cells subjected to compressive force
Authors: Huang Yiping , Zhang Yingying , Li Xiaobei , Liu Hao , Yang Qiaolin , Jia Lingfei , Zheng Yunfei , Li Weiran
Published: August 2018

Objective

The role of long non-coding ribonucleic acids (lncRNAs) during orthodontic tooth movement remains unclear. We explored the lncRNA landscape of periodontal ligament stem cells (PDLSCs) subjected to compressive force.

Materials and methods

PDLSCs were subjected to static compressive stress (2 g/cm2) for 12 hours. Total RNA was then extracted and sequenced to measure changes in lncRNA and messenger RNA (mRNA) expression levels. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to validate the expression levels of certain lncRNAs. Differential expression analysis as well as Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were also performed.

Results

In total, 90 lncRNAs and 519 mRNAs were differentially expressed in PDLSCs under compressive stress. Of the lncRNAs, 72 were upregulated and 18 downregulated. The levels of eight lncRNAs of interest (FER1L4, HIF1A-AS2, MIAT, NEAT1, ADAMTS9-AS2, LUCAT1, MIR31HG, and DHFRP1) were measured via qRT-PCR, and the results were found to be consistent with those of RNA sequencing. GO and KEGG pathway analyses showed that a wide range of biological functions were expressed during compressive loading; most differentially expressed genes were involved in extracellular matrix organization, collagen fibril organization, and the cellular response to hypoxia.

Conclusions

The lncRNA expression profile was significantly altered in PDLSCs subjected to compressive stress. These findings expand our understanding of molecular regulation in the mechanoresponse of PDLSCs.