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Debris widely exists in contact structures, affecting the reliability of structures. In this investigation, the effects of debris on the non-conforming contact stress are investigated through two-body and three-body contact experiments. According to the relationship between the contact length and debris length, debris is divided into long debris and short debris, which show different influences on the contact behaviors. The non-conforming contact stress is reconstructed based on full-field metrology and an inverse method. The evolution of contact stress induced by debris is analyzed with various parameters and contact surface profiles. Different factors, including debris material, debris length, debris thickness, plate material, and load amplitude, are considered in experiments. Their influence rules are discussed and summarized. The plate materials and short debris materials have coupling effects on the contact stress, which is associated with the deformation characteristics of the contact surface. The results provide an experimental reference for the research of non-conforming contact problems. • An innovative inverse method and experiments are designed to investigate the evolution of contact stress induced by debris. • The effects of different types of debris on the non-conforming contact stress are systematically summarized, providing an experimental reference for the research of non-conforming contact problems. • The coupling effects of plate materials and short debris materials on the contact stress evolution are revealed, which is an innovative phenomenon. [ABSTRACT FROM AUTHOR]

Background: The flat punch indentation problem is a typical prototype of conforming contact which can be frequently encountered in many applications. Its characterization is of great difficulty as the interface is embedded and the stress is highly concentrated at the contact boundary. Objective: In this work, an inverse identification method is developed for reconstructing the interfacial stress during flat punch indentation from the measured displacement field. Methods: This method consists of a modeling procedure and a characterization procedure. In the modeling, the basic tendencies of interfacial stress distributions are established and the relationship between the stress and displacement are formulated. In the characterization, the parameters in the model, including the profiles of contact interface and the stress distributions are optimized by matching the calculated displacement to the experiment data. Segmentation-aided digital image correlation is implemented for the displacement acquisition near the contact interface. An optimization framework is developed so the different kinds of parameters can be accurately obtained. Results: Both of simulated experiment and real-world experiment are carried out, and results show that the proposed method can accurately characterize the elastic contact behavior. Conclusions: The modeling merely constrains the tendencies rather than gives a close-form solution of interfacial stress and the identification only requires the measurement of local displacement, which can greatly increase its applicability in applications. [ABSTRACT FROM AUTHOR]

This study aimed to investigate whether computed tomography (CT)-measured erector spinae parameters (ESPs) have diagnostic, severity assessment, and prognostic predictive value in uremic sarcopenia (US). A total of 202 uremic patients were enrolled and divided into two groups: a control group and a sarcopenia group. Sarcopenia was classified into two types: severe and nonsevere. The area, volume, and density of the erector spinae (ES) were measured using chest CT images, and the relevant ESP, including the erector spinae index (ESI), total erector spinae volume (TESV), erector spinae density (ESD), and erector spinae gauge (ESG) were calculated. The occurrence of adverse events was followed-up for 36 months. The diagnostic value and severity of US were determined using the receiver operating characteristic (ROC) curve. Survival curves diagnosed using CT were plotted and compared with the curve drawn using the gold standard. Cox regression analysis was used to identify independent risk factors associated with survival in US. With an area under the curve (AUC) of 0.840 and 0.739, the combined ESP has diagnostic value and the ability to assess the severity of US. There was no significant difference in the survival curve between the combined ESP for the diagnosis of US and the gold standard (P > 0.05). ESI is a standalone predictor of survival in patients with US. ESP measured by CT has diagnostic values for US and its severity, as well as being a predictive value for the prognosis of US. • CT-measured erector spinae parameters can be used to diagnose uremic sarcopenia. • The erector spinae parameter can be used to assess the severity of uremic sarcopenia. • Erector spinae index-independent risk factor for poor prognosis in uremic sarcopenia. [ABSTRACT FROM AUTHOR]

The current-induced perpendicular magnetization switching in $L1$ 0-FePt single layer and Ta/FePt bilayer thin films was investigated. Here, $L1$ 0-FePt (6 nm) single-layer film and Ta (1–5 nm)/FePt (6 nm) bilayer films were deposited on MgO substrate at 700 °C, showing good perpendicular anisotropy with out-of-plane coercivity of 7.5 kOe for FePt and around 5 kOe for Ta/FePt bilayers. It was found that the current-induced partial magnetization-based switching was realized with the spin–orbit torque (SOT) switching ratio of about 3% in all films. For adding the Ta capping layer, the critical current density is reduced and the stability of the switching loop is relatively better when compared to the single FePt layer. Furthermore, harmonic Hall voltage results demonstrate that the SOT efficiency ($\beta _{\mathrm {DL}}$) of FePt single layer is approximately 50 Oe/(107 A cm−2) and significantly higher than that of Ta/FePt bilayers, which is several times higher than that of the traditional Ta/CoFeB/MgO structure reported earlier. More importantly, Ta/FePt bilayer structure exhibits very good memristive switching behavior, which is expected to be applied to the spin-synapse of neural networks in the future. [ABSTRACT FROM AUTHOR]

We present a study on perpendicular magnetic tunnel junctions with W as buffer and capping layers. A tunneling magnetoresistance of 138% and an interfacial magnetic anisotropy of 1.67 erg/cm² were obtained in optimally annealed samples. However, after extended annealing at 420 °C, junctions with W layers showed extremely small resistance due to interdiffusion of W into the MgO barrier. In contrast, in Ta-based junctions, the MgO barrier remained structurally stable despite disappearance of magnetoresistance after extended annealing due to loss of perpendicular magnetic anisotropy. Compared with conventional tunnel junctions with in-plane magnetic anisotropy, the evolution of tunneling conductance suggests that the relatively low magnetoresistance in perpendicular tunnel junctions is related to the lack of highly polarized Δ1 conducting channel developed in the initial stage of annealing. [ABSTRACT FROM AUTHOR]

It is known that the interstitial iron concentration in silicon is reduced after annealing silicon wafers coated with plasma-enhanced chemical vapour deposited (PECVD) silicon nitride films. The underlying mechanism for the significant iron reduction has remained unclear and is investigated in this work. Secondary ion mass spectrometry (SIMS) depth profiling of iron is performed on annealed iron-contaminated single-crystalline silicon wafers passivated with PECVD silicon nitride films. SIMS measurements reveal a high concentration of iron uniformly distributed in the annealed silicon nitride films. This accumulation of iron in the silicon nitride film matches the interstitial iron loss in the silicon bulk. This finding conclusively shows that the interstitial iron is gettered by the silicon nitride films during annealing over a wide temperature range from 250 ° C to 900 ° C, via a segregation gettering effect. Further experimental evidence is presented to support this finding. Deep-level transient spectroscopy analysis shows that no new electrically active defects are formed in the silicon bulk after annealing iron-containing silicon with silicon nitride films, confirming that the interstitial iron loss is not due to a change in the chemical structure of iron related defects in the silicon bulk. In addition, once the annealed silicon nitride films are removed, subsequent high temperature processes do not result in any reappearance of iron. Finally, the experimentally measured iron decay kinetics are shown to agree with a model of iron diffusion to the surface gettering sites, indicating a diffusion-limited iron gettering process for temperatures below 700 ° C. The gettering process is found to become reaction-limited at higher temperatures. [ABSTRACT FROM AUTHOR]

A new two-dimensional non-linear tuned mass damper inerter (2d-NTMDI) is proposed in the present paper with the aim of suppressing bi-directional vibrations. The proposed 2d-NTMDI includes a single mass and two sets of springs, dashpots and inerters configured in two axes. With respect to the displacements in two axes, the resulting restoring forces have nonlinear characteristics. While the proposed novel 2d-NTMDI has the capability of mitigating bi-directional vibrations simultaneously, the nonlinearity of the system makes the optimization a challenging task. The particle swarm optimization (PSO) algorithm is adopted to obtain the optimum design parameters of the 2d-NTMDI. To evaluate the effectiveness, the proposed 2d-NTMDI is deployed in a 5MW-wind turbine blade suffering from bi-directional vibrations in the edgewise and flapwise directions. Therefore, an analytic model of a wind turbine blade with a 2d-NTMDI is derived. The aerodynamic loading is computed using blade element momentum theory. The effectiveness of the 2d-NTMDI is tested under different loading conditions. Also, the fatigue damage of the wind turbine blades is calculated according to the rain-flow cycle counting approach and Miner's law. It is concluded that the optimized design 2d-NTMDI can prolong the blade fatigue life by 24.6%. • A new two-dimensional nonlinear tuned mass damper inerter (2d-NTMDI) is proposed. • The 2d-NTMDI is optimized to minimize the bi-axial RMS responses of wind turbine blades. • The effectiveness of the 2d-NTMDI is examined in a wind turbine blade under different loading conditions. • The 2d-NTMDI can effectively reduce the blade vibrations in edgewise and flapwise directions simultaneously. • Fatigue damage of wind turbine blades can be reduced by around 25% using the 2d-NTMDI. [ABSTRACT FROM AUTHOR]

Summary: Wind, wave and seismic loading induced excessive vibration of offshore wind turbines (OWTs) impairs the wind turbine energy output and escalates its fatigue damage. The present study proposes a three‐dimensional adaptive pendulum tuned mass damper (3D‐APTMD) to control the bidirectional dynamic responses of monopile OWTs exposed to combined wind, wave, seismic loading, and time‐varying structural properties. In terms of the proposed adaptive tuning algorithm, the natural frequency and damping property of the 3D‐APTMD are tuned in real time to match the wind turbine time‐varying dominant frequency caused by environmental and/or structural property variations. Performance of the developed adaptive damper is examined on a monopile 5‐MW (megawatt) baseline wind turbine subjected to representative wind, wave, and seismic loading. Time‐varying stiffness of the tower and foundation is introduced to simulate damage evolution during service life. A three‐dimensional pendulum tuned mass damper (3D‐PTMD) and dual linear TMDs (2TMD) are used for comparison. Research results show that when damage occurs, 3D‐PTMD and 2TMD become partially off‐tuned and less effective. In comparison, the 3D‐APTMD which is tuned in real time maintains its effectiveness. It can improve the reduction effect by around 25% and 30% when compared with the 3D‐PTMD and 2TMD, respectively. Therefore, the proposed 3D‐APTMD is promising for real application to protect OWTs, high‐rise buildings, chimneys, and other types of slender structures suffering from excessive bidirectional vibration, and environmental, operational, and/or structural property variations. [ABSTRACT FROM AUTHOR]

Line contact usually causes stress concentration, resulting in the wear and failure of materials and structures. The characterization of the contact phenomenon thus plays an important role in the safety evaluation of materials and structures. In this paper, an inverse method is developed that can identify the principal parameters in contact by employing the experimentally measured displacements and mathematical optimization. Basing on the contact theory, the relationship between the contact parameters and displacements on the interface is modeled. The parameters are then inversed by matching the modeled displacements to the experimentally measured data through optimization. Only the displacements on the surface of the contact member are required in this method, which can be easily measured by a segmentation-aided digital image correlation approach. By utilizing the proposed method, the contact between a cylinder and a plate is characterized and the variations of the contact parameters associated with the applied loads and cylinder's radius are discussed. Error estimation is carried out by implementing the proposed method with the finite element simulated data. Results show that the proposed method can provide reliable identification results under the influence of different kinds of disturbances. [ABSTRACT FROM AUTHOR]

The traditional lane change trajectory prediction method has some problems such as large deviation of actual estimation and long prediction time. This paper proposes a lane change trajectory prediction method in the network of vehicles environment. Firstly, the hidden Markov model is used to classify the vehicle behavior in networked vehicle environment into three types: left lane change, right lane change and straight lane change. Secondly, according to the vehicle behavior, the lateral displacement is taken as the index to judge the safety state of the vehicle, and the lane-changing intention of the vehicle is analyzed by using the gradient lifting decision tree. Finally, the vehicle state vector is mapped to the social pool according to the result of lane change intention, combined with the vehicle speed and Angle, and the road network information, traffic control information, road traffic flow information, traffic control state information in the Internet of vehicles and real-time traffic environment information are used as lane change trajectory prediction data. Combined with vehicle state vector, lane change trajectory prediction is realized by multilayer perceptron. The experimental results show that the proposed method has a high degree of fitting with the actual trajectory under different time domain conditions, and the root mean square error of prediction is stable within 0.64, and the prediction time is short. [ABSTRACT FROM AUTHOR]

For any positive integer m, let Z m be the set of residue classes modulo m. For A ⊆ Z m and n ¯ ∈ Z m , let the representation function R A (n ¯) denote the number of solutions of the equation n ¯ = a ¯ + a ′ ¯ with unordered pairs (a ¯ , a ′ ¯) ∈ A × A . We characterize the partitions of Z 2 p with A ∪ B = Z 2 p and | A ∩ B | = 2 such that R A (n ¯) = R B (n ¯) for all n ¯ ∈ Z 2 p , where p is an odd prime. [ABSTRACT FROM AUTHOR]

Background As a full-field optical metrology, projection moiré approach has been widely used in many engineering applications. The modeling of moiré system and the calibration, including the calibration of relationship between the moiré phase and object's height, and the calibration of optical system parameters, are the key points in this method as they directly determine the measurement accuracy and complexity of operations. Objective In this paper, a projection moiré system is established and the axes of the projector and the camera are arbitrary. Methods The moiré model is modified based on the idea of iteration to reach a higher precision in describing the topography of the surface. A system calibration method is implemented by adopting a self-calibration approach. Both the projection system and reception system can be parameterized accurately and conveniently, as the error caused by the misalignment of the reference plane and the calibration plate is eliminated. Results The feasibility and accuracy are validated through simulations and experiments. Results show that the proposed methods can reduce the systematic error and simplify the complex of operation effectively. Conclusions By adopting the two methods, the precision and applicability of the established system are greatly improved. [ABSTRACT FROM AUTHOR]

Due to the global supply chain of integrated circuits (IC) from design to application, Hardware Trojan (HT) may be stealthily inserted into ICs. The effect of HT detection methods are related to the signal-to-noise ratio (SNR) and the Trojan-to-circuit ratio (TCR). Various HT detection methods are designed to target at simulated circuits; however, the effect on real chips is not involved. In the light of detection of HT on real chips with low SNR and low TCR, a machine learning method is proposed and experimented in this paper. It is difficult to directly distinguish the insignificant effect of HT on a modern complex chip. The proposed method extracts statistic features to explore the much rich expression of HT signals and adjusts the distance of different features to separate Trojan circuits from the security ones far apart. The proposed methods are tested on real chips with 10−5 TCR and demonstrated the effect compared to other state-of-the-art methods. [ABSTRACT FROM AUTHOR]

An improved characteristic set algorithm for solving Boolean polynomial systems is proposed. This algorithm is based on the idea of converting all the polynomials into monic ones by zero decomposition, and using additions to obtain pseudo-remainders. Three important techniques are applied in the algorithm. The first one is eliminating variables by new generated linear polynomials. The second one is optimizing the strategy of choosing polynomial for zero decomposition. The third one is to compute add-remainders to eliminate the leading variable of new generated monic polynomials. By analyzing the depth of the zero decomposition tree, we present some complexity bounds of this algorithm, which are lower than the complexity bounds of previous characteristic set algorithms. Extensive experimental results show that this new algorithm is more efficient than previous characteristic set algorithms for solving Boolean polynomial systems. [ABSTRACT FROM AUTHOR]

We report the spatio-temporal separation of electron and phonon thermal transports in nanostructured magnetic L10 FePt films at the nanometer length scale and the time domain of tens of picosecond, when heated with a pulsed laser. We demonstrate that lattice dynamics measured using the picosecond time-resolved laser pump/X-ray probe method on the FePt (002) and Ag (002) Bragg reflections from different layers provided the information of nanoscale thermal transport between the layers. We also describe how the electron and phonon thermal transports in nanostructured magnetic thin films were separated. [ABSTRACT FROM AUTHOR]

Field-cycling NMR in the solid state at low temperature (4.2 K) has been employed to measure the tunneling spectra of methyl (CH3) rotors in phenylacetone and toluene. The phenomenon of tunnel resonance reveals anomalies in ¹H magnetization from which the following tunnel frequencies have been determined: phenylacetone, vt = 6.58 ± 0.08 MHz; toluene, vt(1) = 6.45 ± 0.06 GHz and vt(2) = 7.07 ± 0.06 GHz. The tunnel frequencies in the two samples differ by three orders of magnitude, meaning different experimental approaches are required. In phenylacetone the magnetization anomalies are observed when the tunnel frequency matches one or two times the ¹H Larmor frequency. In toluene, doping with free radicals enables magnetization anomalies to be observed when the tunnel frequency is equal to the electron spin Larmor frequency. Cross-polarization processes between the tunneling and Zeeman systems are proposed and form the basis of a thermodynamic model to simulate the tunnel resonance spectra. These invoke space-spin interactions to drive the changes in nuclear spin-symmetry. The tunnel resonance lineshapes are explained, showing good quantitative agreement between experiment and simulations. [ABSTRACT FROM AUTHOR]

The purpose of image fusion is to combine the source images of the same scene into a single composite image with more useful information and better visual effects. Fusion GAN has made a breakthrough in this field by proposing to use the generative adversarial network to fuse images. In some cases, considering retain infrared radiation information and gradient information at the same time, the existing fusion methods ignore the image contrast and other elements. To this end, we propose a new end-to-end network structure based on generative adversarial networks (GANs), termed as FLGC-Fusion GAN. In the generator, using the learnable grouping convolution can improve the efficiency of the model and save computing resources. Therefore, we can have a better trade-off between the accuracy and speed of the model. Besides, we take the residual dense block as the basic network building unit and use the perception characteristics of the inactive as content loss characteristics of input, achieving the effect of deep network supervision. Experimental results on two public datasets show that the proposed method performs well in subjective visual performance and objective criteria and has obvious advantages over other current typical methods. [ABSTRACT FROM AUTHOR]

Because the weight loss of a pig carcass in the spray-chilling process is easily affected by the spraying frequency and duration, a prediction model for weight loss based on a genetic algorithm (GA) back-propagation (BP) neural network is proposed in this article. With three-way crossbred pig carcasses selected as the test materials, the duration and time interval of high-frequency spraying, the duration and time interval of low-frequency spraying, and the duration of a single spray were selected as inputs to the network model. The weight and threshold of the network were then optimized by the GA. The prediction model for pig carcass weight loss established by the GA BP neural network yielded a correlation coefficient of R = 0.99747 between the network output value of the test samples and the target value. Weight loss prediction by the model is feasible and allows better expression of the nonlinear relationship between weight loss and the main controlling factors. The results can be a reference for chilled meat production. [ABSTRACT FROM AUTHOR]

Increasingly demanding performance standards and operating requirements are driving the growing interest on the influence of gear oil film on reliability under the conditions of high speed and heavy load. The fatigue life of gears can be increased by optimizing the oil film thickness on the gear tooth surface. The oil film thickness can reflect the ability of the gear to resist pitting and gluing failure. Many theories and experiments are devoted to the study of the oil film thickness. The improvement of gear manufacturing accuracy also makes the influence of tooth surface roughness on oil film thickness not negligible. In order to compile and categorize key investigations in an expansive field with substantial recent research, this work reviews oil film thickness with focus on numerical calculation methods, influence of gear surface roughness on oil film thickness and fatigue life analysis based on oil film thickness. [ABSTRACT FROM AUTHOR]

Retarding filed analyzers (RFAs) measure the ion velocity distribution in edge plasmas, leading to an estimate of the ion temperature and space potential through curve fitting. This paper describes the bi-directional RFA detector installed on the Experimental Advanced Superconducting Tokamak for edge plasma parameter measurements. The paper also describes a technique to compensate for a known induced noise using a dummy signal line and a method to reconstruct the I–V curve from the scanning voltage signal and the resultant ion current waveform. Fitting to experimental data and numerical simulations show that the I–V curve reconstruction method serves for both smoothing and induction noise compensation purposes. [ABSTRACT FROM AUTHOR]

The major component of aphid alarm pheromone is (E)-β-farnesene (EβF), but the molecular mechanisms of EβF synthesis are poorly understood. Here we established a biological model to study the modulation of EβF synthesis in the bird cherry-oat aphid Rhopalosiphum padi by using quantitative polymerase chain reaction, gas chromatography/mass spectrometry and RNA interference. Our results showed that the rearing conditions significantly affected the weight of adult and modulated EβF synthesis in a transgenerational manner. Specifically, the quantity of EβF per milligram of aphid was significantly reduced in the individually reared adult or 1st-instar nymphs derived from 1-day-old adult reared individually, but EβF in the nymph derived from 2-day-old adult that experienced collective conditions returned to normal. Further study revealed that the production of EβF started in embryo and was extended to early nymphal stage, which was modulated by farnesyl diphosphate synthase genes (RpFPPS1 and RpFPPS2) and rearing conditions. Knockdown of RpFPPS1 and RpFPPS2 confirmed the role played by FPPS in the biosynthesis of aphid alarm pheromone. Our results suggested that the production of EβF starts at the embryo stage and is modulated by FPPS and rearing conditions in R. padi , which sheds lights on the modulatory mechanisms of EβF in the aphid. [ABSTRACT FROM AUTHOR]

Aim: To investigate the collaborative networks among expert clinical nurse and midwifery researchers in eastern and southern Africa. Methods: Thirty‐eight clinical nurse and midwifery researchers completed an online survey to analyse collaboration between respondents. Data were analysed using social network analysis, generating a network map and associated measurements. Results: Regional collaboration was poor. Those links that did exist centred on geographic proximity and participation in regional and international organizations. Conclusion: These results help us to understand better ways to strengthen and support nursing and midwifery clinical research in eastern and southern Africa. Implications for nursing policy: Clinical nursing and midwifery research capacity building efforts should focus on supporting collaboration networks among individuals and institutions in the region. [ABSTRACT FROM AUTHOR]

Chronic nasal sinusitis with nasal polyps (CRSwNP) is a reversible nasal mucosal remodeling disease caused by persistent inflammation and structural changes in chronic nasal mucosa. Although there have been many studies on the inflammation of the nasal mucosa epithelium, the mechanism remains unclear. Our study found that H3K4me3 histone demethylase KDM2B (also known as JHDM1B) and transcriptional regulator Brg1 (also called SNF2-β or Smarca4) were significantly decreased in nasal mucosa of CRSwNP patients, and they were positively correlated. Brg1 and KDM2B co-localize in the epithelial cells of nasal mucosa. We used poly(I:C)-treated nasal mucosal epithelial cells (HNECs) to find that the expression of KDM2B and Brg1 was also decreased, and the main expression position transferred from the nucleus to the nuclear membrane. We used small interfering RNA to knock down the expression of KDM2B and Brg1 in nasal epithelial cells. It was interesting to find that the decreased expression of KDM2B and Brg1 produced similar effects to that of poly(I:C)-treated cells, which could promote inflammatory response of nasal mucosal epithelial cells. And Brg1 appears to play a role in KDM2B regulating gene promoters of IL-6 and TNF-α inflammatory. This study shows that KDM2B and Brg1 may have an inhibitory effect on the development of CRSwNP nasal mucosal epithelial inflammation. This study will provide a new perspective for gene targeting therapy of CRSwNPs. [ABSTRACT FROM AUTHOR]

An experimental study to investigate the various characteristics of the nonlinear behavior of a ferroelectric ceramic material under different electrical and mechanical loading conditions is reported. The nonlinear strain behavior under different loading conditions is obtained and used for studying the effect of residual stress, developed in the ferroelectric ceramic material during manufacture, on domain switching under applied loads. First, the behavior at low electric field and mechanical stress are studied by comparing the linear piezoelectric properties measured from the strain responses under mechanical and electrical loading with those measured by resonance method. This is followed by an investigation on the mechanism of polarization reversal due to cyclic electric field. Based on the observed large magnitude of strain and the comparison of the magnitude of the sum of transverse strains with the magnitude of strain in the poling direction it is concluded that polarization reversal due to cyclic electric field in the ferroelectric material at morphotropic phase boundary is the result of two successive 90° domain switchings of the individual domains rather than a direct 180° domain switching. Finally, two types of combined loading experiments were conducted to investigate the residual stress effect on the mechanism of domain switching. The behavior under combined loading shows many interesting characteristics. An attempt is made to explain the characteristics of the nonlinear ferroelectric behavior observed in the present experimental study based on the effect of residual stress on domain switching. [ABSTRACT FROM AUTHOR]

A semicontinuum model is presented for nanostructured materials that possess a platelike geometry, such as ultra-thin films. In contrast to the classical continuum theory, the current model accounts for the discrete nature in the thickness direction. In-plane Young's modulus, and in-plane and out-plane Poisson's ratios are investigated with this model. It is found that the values of the Young's modulus and Poisson's ratios depend on the number of atom layers in the thickness direction and approach the respective bulk values as the number of atom layers increases. [ABSTRACT FROM AUTHOR]

Microstereolithography (μSL) uses laser light to solidify UV-curable rosin mixed with concentrated ceramic powders. During the μSL process, the light scattering from the particle suspension is found to significantly influence the fabrication resolution in both lateral and depth dimensions which are critical for the complex three-dimensional (3D) microfabrication. In this work, we performed Monte Carlo simulations and experimental studies to understand the detailed microscale optical scattering, chemical reaction (polymerization), and their influence on critical fabrication parameters. As a result, it was found that due to the scattering, the fabricated line is wider in width and smaller in depth compared with polymeric fabrication at the same condition. The doping technique that we used substantially reduced the light scattering, which in turn enhanced the fabrication precision and control. In addition, the experimental values of curing depth and radius agreed reasonably well with the theoretical modeling. When a laser beam was focused to the diffraction limit, an ultimate linewidth resolution with ceramic μSL was found at about 2.6 μm. [ABSTRACT FROM AUTHOR]

In this study, high-quality ZnO:Al (ZAO) films were prepared by using dc reaction magnetron sputtering technology. The effect of Al doped in ZnO films on electrical and optical properties and its scattering mechanism were discussed in detail. The results showed that Al[sub 2]O[sub 3] could be effectively removed by controlling oxygen flow and Al-doped concentration during deposition of ZnO:Al films. Zn, Al, and oxygen elements were well distributed through the films. For highly degenerated ZnO:Al semiconductor thin films, it was revealed that ionized impurity scattering dominated the Hall mobility of the films in the low-temperature range; while the lattice vibration became a major scattering mechanism in the high-temperature range. The grain-boundary scattering only played a major role in the ZAO films with small grain size (as compared to the electron mean-free path). The photoelectric properties of ZAO films showed that the lower resistivity (∼5×10[sup -4] Ω cm) was obtained, and transmittance in the visible range and reflectance in the IR region were above 80% and 60%, respectively. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Investigates the crystal morphologies and phase composition of diamond crystallites during bias enhanced nucleation and initial growth stages in microwave plasma chemical vapor deposition. Induction of secondary nucleation sites on the formed nuclei by excessive ion bombardment; Secondary nucleation's deterioration of the alignment of the growing crystals.

Abstract Offshore wind turbines (OWTs) subjected to combined wind and wave loadings experience excessive bi-directional vibrations that adversely influence the system performance and the structural integrity. The present paper utilizes a three-dimensional pendulum tuned mass damper (3d-PTMD) to mitigate the bi-directional vibrations as well as harvest the kinetic energy using a linear electromagnetic energy harvester. The proposed energy harvester consists of magnets and coil assemblies which are connected with the pendulum to convert the kinetic energy of the pendulum into electricity. An analytical model of the offshore wind turbine coupled with the 3d-PTMD is established using Euler-Lagrangian equation. The mathematical model of the linear electromagnetic energy harvester is established and integrated with the wind turbine model. The optimum design of the electromagnetic energy harvester to minimize the nacelle displacement RMS as well as to maximize the energy output is determined via a numerical search method. The NREL 5 MW baseline wind turbine model is utilized to evaluate the performance of the 3d-PTMD and the energy harvester. Results show that the 3d-PTMD can reduce the bi-directional vibrations induced by misaligned wind and wave loadings. Additionally, electrical energy in orders of magnitude of kilowatts can be harnessed via using the energy harvester. Highlights • An analytical model of an offshore wind turbine coupled with a 3d-PTMD and an energy harvester is established. • The 3d-PTMD can effectively mitigate bi-directional vibrations of the nacelle and harvester energy. • Electrical energy in orders of magnitude of kilowatts can be harnessed. [ABSTRACT FROM AUTHOR]

Abstract The present paper proposes a novel adaptive passive stiffness (APS) device which can produce variable stiffness in an adaptive fashion. This APS device consists of four springs arranged in a rhombus configuration and a guidance template. The stiffness of the device is controlled through varying the angle of the rhombus configuration. The function of the guidance template is to relate the angle of the rhombus to the targeted system response such that the stiffness can be varied in an adaptive manner, without the need for feedback or external energy. Two analytical models are developed to capture the behavior of the APS device which shows good agreement with the experimental data. Experimental result indicates that the proposed APS device can produce adaptive stiffness as expected. A cubic nonlinearity is produced and deployed in a single-degree-of-freedom (SDOF) system to form a hardening Düffing oscillator. Dynamic tests show that the experimental characteristics of the Düffing system agrees well with the numerical results, thereby demonstrating that the APS device is effective in producing smoothly and continuously adaptive stiffness in an adaptive fashion. In addition, a fourth order even function is used as the guidance template to produce a softening-hardening adaptive stiffness. The performance of this adaptive stiffness is numerically evaluated for seismic protection. It is found that the structural responses can be reduced effectively when using this softening-hardening adaptive stiffness. The key value of this APS device is that the guidance template can be easily changed to any desired continuous function such that the targeted adaptive stiffness can be obtained. This provides possibility for controlling the vibrations of structures in a passively adaptive manner. Highlights • A novel adaptive passive stiffness (APS) device is proposed, modeled and tested. • Theoretical models have been developed to characterize the behavior of the device. • Experimental results show that the APS device can produce smooth and continuous nonlinear stiffness in an adaptive fashion. • Numerical results show that the produced softening-hardening stiffness is effective for seismic protection. [ABSTRACT FROM AUTHOR]

Rice bacterial leaf streak (BLS), caused by Xanthomonas oryzae pv. oryzicola (Xoc), is a prevalent disease worldwide. Melatonin, an indoleamine with the chemical name N‐acetyl‐5‐methoxytryptamine, is known to inhibit the growth of human pathogenic bacteria. However, the impact of melatonin on agricultural pathogenic bacteria remains poorly understood. In this study, the effect of melatonin on Xoc was investigated. Exogenous melatonin (200 μg mL−1) significantly inhibited the growth of Xoc and reduced the mRNA expression level of seven cell division‐related genes. Melatonin reduced the pathogenicity of Xoc towards the susceptible rice IR24. The lesion length in IR24 infected by Xoc pretreated with melatonin (200 μg mL−1) was more than 23% smaller than the lesion length of the control group. Similarly, infection of IR24 leaves by Xoc pretreated with melatonin (200 μg mL−1) reduced the bacterial population by 45%. The biofilm formation, swimming motility and extracellular protease activities of Xoc also decreased under melatonin treatment. Melatonin only slightly changed the morphology of Xoc but significantly reduced the mRNA expression of toxin genes. Furthermore, treating leaves with exogenous melatonin reduced the incidence of BLS by 17%. It is reported for the first time that melatonin reduces pathogenicity and may serve as a bactericide for controlling BLS disease. [ABSTRACT FROM AUTHOR]

Abstract The Thermal Control Coatings (TCC) on the surfaces of lunar rover/landers plays an important role for radiation heat transfer to allow the detectors survive the extremely critical thermal environment on the moon. Optical Solar Reflector (OSR) coating is usually considered as a good candidate TCC due to its excellent radiation properties such as low solar absorptance and high infrared emittance. In this study, SiO 2 /Ag coating, commonly used as OSR, was investigated to study its radiation properties, combining experiment measurement with numerical simulations. Based on the self-made setup with the comparison method, the temperature dependence of the normal infrared emittance of the OSR coating was obtained, covering the temperature range from 326 K to 404 K, to simulate the temperature condition on the Moon in the daytime. The direction hemisphere spectral reflectance at the typical wavelength of 0.6328 μm, 1.34 μm and 3.39 μm was also investigated in details. It was found that the spectral reflectance of the OSR coating at visible wavelengths is much higher than that at infrared wavelengths. In addition, numerical simulation result showed good agreement with the experimental data, and the relative error is 4.49% at 0.6328 μm. [ABSTRACT FROM AUTHOR]

The aims of this systematic review were to compare the incidence and intensity of postoperative pain after single‐visit root canal treatment using manual, rotary, and reciprocating instruments. An extensive literature search in PubMed, EMBASE, Cochrane Library, and Web of Science was performed to identify investigations that evaluated the effects of different instruments on postendodontic pain. Meta‐analyses and additional analyses, including subgroup and sensitivity analyses, were conducted. We included seventeen trials in this study. Pooled results showed that patients treated with rotary instruments experienced a significantly lower incidence of postoperative pain (RR, 0.32, p = .0005) and reduced pain intensity than did patients treated with manual instruments. In addition, patients treated with multiple rotary‐file systems experienced a significantly lower incidence of postoperative pain than did those treated with reciprocating systems (RR, 0.73; p < .0001). The use of rotary instruments contributed to a lower incidence and intensity of postoperative pain than did the use of hand files in patients who received single‐visit root canal treatment. In addition, the use of multiple rotary‐file systems contributed to a lower incidence of postoperative pain than did the use of reciprocating systems. [ABSTRACT FROM AUTHOR]

We present the linear simulations of edge plasma instabilities using the 3-field peeling-ballooning model and gyro-Landau-fluid model under the BOUT++ framework. A series of realistic equilibria of shifted circular geometry are generated by a global equilibrium solver CORSICA, where the Shafranov shift, elongation effects, and bootstrap current are included. The linear growth rate spectrum of the peeling-ballooning modes is shown in a wide range of pressure gradient and parallel current density in the pedestal region. The results show that the bootstrap current stabilizes high beta ballooning modes. The simulations with different fractions of bootstrap current indicate a trend for the existence of the high beta peeling-ballooning mode stability region. Taking the kinetic effects into account, the linear simulations of kinetic peeling-ballooning mode using the gyro-Landau-fluid model show that this region can be accessed. [ABSTRACT FROM AUTHOR]

Discusses the use of functional integrals in quasimomentum space or normal mode analysis to study configurational statistics of wormlike chains (WLC) and properties of WLC in an external field. Difference between correlation functions and end to end distance distribution functions; Exhibition of a crossover by the WLC from an ideal Gaussian chain to a rodlike chain with the variation of a parameter.

Presents a study which examined the thermal stability of gallium nitride thin films grown on (001) aluminum[sub2]oxygen[sub3] and (0001)[subsilicon] 6 hydrogen-silicon carbide substrates. Experimental method; Results; Discussion.

Presents information on a study which proposed a crystallographic model to describe the epitaxial growth of wurtzite-type thin films such as gallium nitride on different orientations of sapphire substrates. Description of large-band gap semiconductors; Methodology of the study; Results and discussion.

Focuses on a study which examined thin aluminum nitride (AlN) films grown on different orientations of sapphire substrates by metalorganic chemical vapor deposition. Description of the crystal; Epitaxial relationship between AlN and gallium nitride films and sapphire substrates; Discussion on results; Interpretation of results using extended atomic distance mismatch.

Binary diffusion coefficients at high dilution are measured for ethane and ethylene dissolved in cyclohexane at temperatures from 280.5 to 363.2 K and for benzene in cyclohexane and n-hexane up to their critical temperatures. With the effective hard-sphere diameters backed out from self-diffusion data from both solute and solvent molecules and fitted to Protopapas, Anderson, and Parlee’s formula, the prediction with the Sung–Stell theory is found to agree to within ±7% of experimental data for wide ranges of solute-to-solvent mass and size ratios at temperatures up to the critical point. [ABSTRACT FROM AUTHOR]

• Tests were conducted to study deck bracing effects on continuous stringer LTB resistance. • Finite element analyses were performed to simulate behavior of the tested grillage. • Continuous stringer LTB resistance can be tripled considering noncomposite deck bracing effects. Louisiana's bridges used two-girder or truss systems in the 1950 s and 1960 s, in which floorbeams are carried by main members and continuous stringers are supported by the floorbeams. The main members are either two edge (fascia) girders or trusses. Continuous span stringer bottom flanges are in compression in their negative moment regions, which could result in lateral torsional buckling (LTB). When these stringers are load rated using AASHTOWare Bridge RatingTM analysis software, lateral torsional buckling (LTB) resistance is calculated in accordance with the AASHTO LRFD Bridge Design Specifications, which the authors have determined may not adequately account for bracing effects provided by a noncomposite deck, and therefore could underestimate the flexural strength. Resulting ratings may be low enough to require restrictive, and possibly unnecessary, load postings or even bridge closures. This issue affects more than 20 significant bridges that are key parts of Louisiana's highway system. To address the challenge of underestimated stringer LTB resistance and assess bracing effects provided by a concrete deck, experimental and analytical studies were performed on a two-span, continuous, steel stringers in a grillage system, which included three stringer lines, an interior transverse support (floorbeam), and transverse diaphragms at the end supports. The tests encompassed a variety of configurations, with and without a concrete deck. This paper describes laboratory testing setups and discusses experimental results, focusing on bracing effects on LTB resistance due to the presence of a noncomposite concrete deck. Finite element models using ANSYS were calibrated, validated using test results and used to simulate stringer behavior in Louisiana's representative bridges. Finite element analyses of various tests showed generally comparable results to test data, and provided a feasible approach to load rate continuous stringers if a refined analysis is deemed necessary. The studies showed that stringer LTB resistance could possibly be tripled when noncomposite deck bracing effects are considered. [ABSTRACT FROM AUTHOR]

ScN in the rock salt structure is a well-investigated material due to its desirable properties like the high hardness or large thermal conductivity. Recent computations by Adamski et al. [Appl. Phys. Lett. 115, 232103 (2019)] showed that ScN/GaN heterostructures exhibit an outstanding polarization gradient which would be beneficial for polarization induced electron gases. The pseudobinary semiconductor Sc x Al 1 − x N, when maintaining the cubic rock salt structure, could be beneficial for tailoring the polarization gradient using the Sc dependency of material properties. The structural properties of rs-Sc x Al 1 − x N are not fully discovered yet, thus in this work, DC-magnetron sputtered cubic rock salt Sc x Al 1 − x N thin films with 0.55 < x < 1.00 were grown and analyzed on ScN(111)/Si(111). The epitaxial relation of ScN(111) thin films on the Si(111) substrate is determined to be ScN[110] ∥ Si[100]. Furthermore, concentration dependent properties like the lattice parameter of Sc x Al 1 − x N were measured [a(ScN) = 4.50 Å, a(Sc0.55Al0.45N) = 4.30 Å] and the stress σ within the layers was determined. The crystal quality was evaluated using ω -scans, revealing FWHM = 1.14 ° for Sc0.95Al0.05N. The diameters of the columns were determined by atomic force microscopy and scanning electron microscopy and they are range from 34 to 59 nm for 0.55 < x < 1.00. At x = 0.55 , Sc x Al 1 − x N columns in the hexagonal wurtzite as well as cubic rock salt structure were detected. This information about the structural specifications of Sc x Al 1 − x N in the rock salt structure forms the basis for further investigations and experimental confirmation of the electric properties of ScN/GaN heterostructures or even a Sc x Al 1 − x N/GaN based approach for improved structures for high-electron-mobility transistors. [ABSTRACT FROM AUTHOR]

In order to increase the resistive switching performance of memory devices based on TiN electrode, it is desirable to fabricate TiN with good oxygen reservoir ability. In the present paper, we report that the crystallized (200) textured TiN electrode were achieved by epitaxial grown on CrRu intermediate layer, which had better oxygen reservoir ability than the amorphous TiN. It is found that the Pt/HfO 2 /TiN devices with crystallized TiN electrode exhibited a typical bipolar resistive switching behavior, while the I-V curves of the Pt/HfO 2 /TiN devices with amorphous TiN electrode showed the unipolar resistive switching behavior regardless of voltage polarity, which is similar to the Pt/HfO 2 /Pt devices. It is believed that this originates from the different oxygen reservoir ability of TiN with different fabricating process. Moreover, the RRAM device with the new structure of TiN (amorphous)/HfO 2 /TiN (crystallized) exhibited the bipolar resistive switching behavior. This further proved the amorphous TiN electrode had poorer ability of oxygen reservoir than crystallized TiN, which was similar to a noble electrode like Pt electrode. Tuning the resistive switching behaviors of RRAM devices by controlling the crystalline state of TiN electrode may offer a method for fabrication of transition metal oxides based RRAM device with good performances. [ABSTRACT FROM AUTHOR]

Offshore wind turbines suffer from excessive bi-directional vibrations due to wind-wave misalignment and vortex induced vibrations. However, most of existing research focus on unidirectional vibration attenuation which is inadequate for real applications. The present paper proposes a three dimensional pendulum tuned mass damper (3d-PTMD) to mitigate the tower and nacelle dynamic response in the fore-aft and side-side directions. An analytical model of the wind turbine coupled with the 3d-PTMD is established wherein the interaction between the blades, the tower and the 3d-PTMD is modeled. Aerodynamic loading is computed using the Blade Element Momentum method where the Prandtls tip loss factor and the Glauert correction are considered. JONSWAP spectrum is adopted to generate wave data. Wave loading is computed using Morisons equation in collaboration with the strip theory. Via a numerical search approach, the design formula of the 3d-PTMD is obtained and examined on a National Renewable Energy Lab (NREL) monopile 5 MW baseline wind turbine model under misaligned wind, wave and seismic loading. Dual linear tuned mass dampers (TMDs) deployed in the fore-aft and side-side directions are utilized for comparison. It is found that the 3d-PTMD with a mass ratio of 2 % can improve the mitigation of the root mean square and peak response by around 10 % when compared with the dual linear TMDs in controlling the bi-directional vibration of the offshore wind turbines under misaligned wind, wave and seismic loading. [ABSTRACT FROM AUTHOR]

We report the formation of tetragonal gas bubble superlattice in bulk molybdenum under helium ion implantation at 573 K. The transmission electron microscopy study shows that the helium bubble lattice constant measured from the in-plane d-spacing is ~4.5 nm, while it is ~3.9 nm from the out-of-plane measurement. The results of synchrotron-based small-angle x-ray scattering agree well with the transmission electron microscopy results in terms of the measurement of bubble lattice constant and bubble size. The coupling of transmission electron microscopy and synchrotron high-energy X-ray scattering provides an effective approach to study defect superlattices in irradiated materials. [ABSTRACT FROM AUTHOR]

Summary: This study investigated the prevalence of MRSA in samples taken in households, with and without backyard pigs in villages in a rural area of Shandong Province, China. Community‐associated MRSA and livestock‐associated MRSA, belonging to ST59 and ST9, respectively, were identified in both humans and pigs. The genotypic and phenotypic comparison of isolates indicates that bidirectional transmission of MRSA has occurred between humans and pigs in the villages. [ABSTRACT FROM AUTHOR]

Abstract: The ability to recover from drought stress after re‐watering is an important feature that will enable plants to cope with the predicted increase in episodic drought. The effects of pre‐drought and re‐watering conditions on leaf spectral properties and their relationships with the biochemical processes that underlie the recovery from pre‐drought conditions should be better understood. The reflectance spectra, 10 spectral reflectance indices (SRIs) and biochemical characteristics of maize (Zea mays) leaves were monitored 7, 14, 21 and 28 days after the initiation of soil drought stress during two successive cycles of drought and re‐watering periods. The leaf reflectance of the two inbred maize lines increased under the drought stress, especially in the visible spectral range. In addition, an obvious recovery of the leaf reflectance was only observed in the first re‐watering period, and its value remained higher than that of the control plants during the second recovery period. A recovery lag in the pigment contents was also observed during the second cycle. The recovery variations in the pattern and magnitude of the SRIs and the total contents of C, N and P that were measured in response to the re‐watering during both cycles were diverse and complex; both full and partial recoveries were observed. The SRIs representing different physiological attributes of plant growth, including the water index, red edge position, photochemical reflectance index and near‐infrared reflectance at 800 nm, showed strong linear relationships (P < 0.01 or 0.05) with the growth and biochemical traits across the successive drought and re‐watering cycles. The results suggest that maize plants can adjust their leaf reflectance properties and employ growth and biochemical strategies to adapt to cyclic drought stress and recover from drought stress after re‐watering. [ABSTRACT FROM AUTHOR]

The experimental identification of contact stress is important in many areas. In this paper, we present an inverse method for identifying the stress distribution on non-conforming contact interface based on local displacement measurements. A mechanical model is established to formulate the relationship between the contact stress and the displacement field near the interface. An optical method, named segmentation-aided digital image correlation is utilized to measure the near-field displacement. The contact stress is then inversed by finding the optimal model that best matches the measurements. Three model parameters, i.e., the contact center, contact length and maximum contact stress, are identified through an optimization procedure. The parameters are initialized by an image processing method and then iteratively refined by minimizing the discrepancy between the model predictions and the measured displacements. Both simulated and real-world experiments are conducted and the results verify the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]