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The two-dimensional time-harmonic dynamic Green’s functions in an infinite transversely isotropic piezoelectric solid are obtained. After introduction of a new function, the original problem is reduced to the determination of the Green’s function for the two-dimensional Helmholtz equation and that for the two-dimensional Laplace equation. The explicit expressions of all the field components are presented. It is verified that the obtained dynamic Green’s functions can reduce to the corresponding static ones by letting the circular frequency be zero. The asymptotic expansions for Green’s functions at far-field are also given. [Copyright &y& Elsevier]

A general solution of the three-dimensional equilibrium problem of spherically isotropic magnetoelectroelastic media is presented. Base on the obtained general solution, exact and compact form solutions are obtained for (1) a spherically isotropic magnetoelectroelastic cone subjected to concentrated force, concentrated couple, a point charge and a point electric current at its apex; (2) a spherically isotropic magnetoelectroelastic space with a concentrated force at the origin; (3) a spherical shell under spherically symmetric deformation; and (4) stress concentration around a spherical cavity subjected to remote uniform tensile force, electric charge and electric current. [Copyright &y& Elsevier]

An exact three-dimensional analysis is presented for a functionally gradient piezoelectric material rectangular plate that is simply supported and grounded along its four edges. The state equations of the functionally gradient piezoelectric material are developed based on the state space approach. Assuming that the mechanical and electric properties of the material have the same exponent-law dependence on the thickness-coordinate, we obtain an exact three-dimensional solution of the coupling electroelastic fields in the plate under mechanical, and electric loading on the upper and lower surfaces of the plate. The influences of the different functionally gradient material properties on the structural response of the plate to the mechanical and electric stimuli are then studied through examples. [Copyright &y& Elsevier]

The problem of a Yoffe-type conducting crack moving with a constant velocity at the interface of two dissimilar piezoelectric half planes is investigated by employing complex variable method. Solutions for the complex potentials are derived. Explicit expressions for the field components on the interface are presented based on the obtained complex potentials. It is observed that the nature of the field singularities near the crack tip is intimately dependent on the crack moving velocity. In the extremely low speed regime, the singularities are δ=−1/2±iϵ1; in the low speed regime, the singularities are δ=−1±iϵ2; in the intermediate speed regime, the singularities are δ=−1/2±k; in the high speed regime, the singularities are δ=−1±iϵ3; in the extremely high speed regime, the singularities are δ=−1/2±iϵ4. ϵi (i=1–4) and k are also explicitly given. A Yoffe-type moving conducting crack in a homogeneous piezoelectric material is treated as a special case. The numerical results demonstrate that the moving velocity V will exert a significant influence on the value of the singularities, and on the field component distributions along the interface. [Copyright &y& Elsevier]

The use of sagittally bent asymmetric Laue crystals in horizontally focusing monochromators for high-energy synchrotron X-rays necessitates simulation of the X-ray reflectivity by such crystals. Based on the theory of the lattice distortion in the diffraction plane of sagittally bent Laue crystals, a lamellar model was developed to predict their rocking curves. The model was experimentally verified by rocking-curve measurements from various reflections on silicon crystals of four representative orientations, sagittally bent to various radii, using X-rays of 67 keV energy. [ABSTRACT FROM AUTHOR]

The present paper investigates the problem of a conducting arc crack between a circular piezoelectric inclusion and an unbounded piezoelectric matrix. The original boundary value problem is reduced to a standard Riemann–Hilbert problem of vector form by means of analytical continuation. Explicit solutions for the stress singularities δ=−(1/2)±iϵ are obtained, closed form solutions for the field potentials are then derived through adopting a decoupling procedure. In addition, explicit expressions for the field component distributions in the whole field and along the circular interface are also obtained. Different from the interface insulating crack, stresses, strains, electric displacements and electric fields at the crack tips all exhibit oscillatory singularities. We also define a complex electro-elastic field concentration vector to characterize the singular fields near the crack tips and derive a simple expression for the energy release rate, which is always positive, in terms of the field concentration vector. The condition for the disappearance of the index ϵ is also discussed. When the index ϵ is zero, we obtain conventionally defined electro-elastic intensity factors. The examples demonstrate the physical behavior and the correctness of the obtained solution. [Copyright &y& Elsevier]

This paper studies a transversely isotropic rod containing a single cylindrical inclusion with axisymmetric eigenstrains. The analytical elastic solution is obtained for the displacements, stresses and elastic strain energy of the rod. The effects of microstructural parameters and its evolution on the elastic stress and strain fields as well as the strain energy of the rod are quantitatively demonstrated through examples. [Copyright &y& Elsevier]

The article focuses on the instrumentation, mechanism and applicability of Diffraction Enhanced Imaging (DEI) in soft tissue imaging. It offers brief information on principles and concepts of DEI including the preparation of an imaging beam, the refraction and extinction as two sources of image contrast to radiography, and the stages of scanning. It also explores the DEI imaging in breast, cartilage, and lungs.

A moving screw dislocation in a transversely isotropic piezoelectric material is investigated in detail. The analytical expressions for displacement, electric potential, stresses, electric displacements, strains, and electric fields are obtained. When the velocity of the dislocation is zero, or when the piezoelectric constant is zero, the results derived in this paper can reduce to known results. [Copyright &y& Elsevier]

The use of bent asymmetric Laue crystals to sagittally focus high-energy synchrotron X-rays calls for an understanding of the mechanisms affecting X-ray diffraction by such crystals. The rocking-curve width, a measurable quantity directly related to the distortion of the lattice planes, is the necessary first step towards such an understanding. A model is formulated for assessing the rocking-curve widths of sagittally bent Laue crystals, considering the elastic anisotropy. A method for depth-resolved measurement of the rocking curves was also developed to verify the model. The model successfully explains the wide range of rocking-curve widths of a large number of reflections from silicon crystals with two different orientations. [ABSTRACT FROM AUTHOR]

Hydrophobic bile acids lead to generation of oxygen free radicals in mitochondria. Accordingly, this study investigated if gene delivery of superoxide dismutase (SOD) would reduce hepatic injury caused by experimental cholestasis. Rats were given adenovirus (Ad; 3 × 10[sup 9] p.f.u., i.v.) carrying the bacterial control gene lacZ, mitochondrial Mn-SOD or cytosolic Cu/Zn-SOD genes 3 days before bile duct ligation. Both Mn- and Cu/Zn-SOD activity was increased in the liver about four-fold 3 days after viral infection. Serum alanine transaminase increased to about 710 U/l after bile duct ligation, which was blunted by about 70% in rats receiving AdMn-SOD, but by only 30% in rats receiving Ad-Cu/Zn-SOD. Bile duct ligation caused focal necrosis, apoptosis and fibrosis in the liver and increased collagen α1 mRNA about 20-fold. These effects were reduced significantly by Ad-MnSOD, but not by Ad-Cu/Zn-SOD. In addition, bile duct figation increased 4-hydroxynonenal, a product of lipid peroxidation, activated NF-κB and increased synthesis of TNFα and TGF-β. These effects were also blunted significantly by Ad-Mn-SOD, but not by Ad-Cu/Zn-SOD. Taken together, it is concluded that cholestasis causes liver injury by mechanisms involving mitochondrial oxidative stress. Gene defivery of mitochondrial Mn-SOD blocks formation of oxygen radicals and production of toxic cytokines thereby minimizing liver injury caused by cholestasis. [ABSTRACT FROM AUTHOR]

Examines the use of asymmetric laue crystal in synchrotron X-rays. Measurement of the rocking curve; Factors controlling the angle of the lattice plane; Improvement on asymmetric laue crystal.

Part I. Presents a study which demonstrated the ability of asymmetric Laue crystals to focus X-rays sagitally. Extent of focusing; Facilitation of anti clastic bending; Sagital focusing with a single-bounced monochromator.

In this article, the feasibility of atomic force microscope (AFM) scanning moiré on a cross-line diffraction grating has been studied. The AFM scanning moiré technique has been applied to measure the thermal deformation of electronic packages successfully. This technique is convenient to perform the mismatch method, also it could obtain a higher resolution than any other moiré method. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Examines the use of a prism to discriminate between different harmonic orders of a two-crystal non-dispersive monochromator. Effect of the refractive prism on the silicon 333 reflection; Suppression of higher-order harmonics; Ability of the second crystal to allow the selection of a specific harmonic order.

Provides information on a study which developed an exact solution for the problem of a spherical inclusion with an imperfectly bonded interface. Problem formulation; Decomposition of the problem; Details on the solutions; Discussion.

Provides a comprehensive theoretical treatment of the eigenstrain problem of a spherical inclusion with an imperfectly bonded interface. Study of tangential and normal discontinuities at the interface; Derivation of Burger's vector of the equivalent Somigliana dislocation for isotropic materials; Non-uniformity of the stresses inside the inclusion.

Large-area X-ray imaging is one of the most widely used imaging modalities that spans several scientific and technological fields. Currently, the direct X-ray conversion materials that are being commercially used for large-area (> 8 cm × 4 cm without tiling) flat panel applications, such as amorphous selenium (a-Se), have usable sensitivities of up to only 30 keV. Although there have been many promising candidates (such as polycrystalline HgI2 and CdTe), none of the semiconductors were able to assuage the requirement for high energy (> 40 keV) large-area X-ray imaging applications due to inadequate cost, manufacturability, and long-term performance metrics. In this study, we successfully demonstrate the potential of the hybrid Methylammonium lead iodide (MAPbI3) perovskite-based semiconductor detectors in satisfying all the requirements for its successful commercialization in synchrotron and medical imaging. This new generation of hybrid detectors demonstrates low dark current under electric fields needed for high sensitivity X-ray imaging applications. The detectors have a linear response to X-ray energy and applied bias, no polarization effects at a moderate bias, and signal stability over long usage durations. Also, these detectors have demonstrated a stable detection response under BNL's National Synchrotron Light Source II (NSLS-II) 70 keV monochromatic synchrotron beamline. [ABSTRACT FROM AUTHOR]

Background: Objective measures of screen time are necessary to better understand the complex relationship between screen time and health outcomes. However, current objective measures of screen time (e.g., passive sensing applications) are limited in identifying the user of the mobile device, a critical limitation in children's screen time research where devices are often shared across a family. Behavioral biometrics, a technology that uses embedded sensors on modern mobile devices to continuously authenticate users, could be used to address this limitation. Objective: The purpose of this scoping review was to summarize the current state of behavioral biometric authentication and synthesize these findings within the scope of applying behavioral biometric technology to screen time measurement. Methods: We systematically searched five databases (Web of Science Core Collection, Inspec in Engineering Village, Applied Science & Technology Source, IEEE Xplore, PubMed), with the last search in September of 2022. Eligible studies were on the authentication of the user or the detection of demographic characteristics (age, gender) using built-in sensors on mobile devices (e.g., smartphone, tablet). Studies were required to use the following methods for authentication: motion behavior, touch, keystroke dynamics, and/or behavior profiling. We extracted study characteristics (sample size, age, gender), data collection methods, data stream, model evaluation metrics, and performance of models, and additionally performed a study quality assessment. Summary characteristics were tabulated and compiled in Excel. We synthesized the extracted information using a narrative approach. Results: Of the 14,179 articles screened, 122 were included in this scoping review. Of the 122 included studies, the most highly used biometric methods were touch gestures (n = 76) and movement (n = 63), with 30 studies using keystroke dynamics and 6 studies using behavior profiling. Of the studies that reported age (47), most were performed exclusively in adult populations (n = 34). The overall study quality was low, with an average score of 5.5/14. Conclusion: The field of behavioral biometrics is limited by the low overall quality of studies. Behavioral biometric technology has the potential to be used in a public health context to address the limitations of current measures of screen time; however, more rigorous research must be performed in child populations first. Systematic review registration: The protocol has been pre-registered in the Open Science Framework database (https://doi.org/10.17605/OSF.IO/92YCT). [ABSTRACT FROM AUTHOR]

Proposed is a simplified analytical propagation model in railway environments. A heuristic ray tracing with geometrical optics and uniform theory of diffraction are adopted. Four typical and dominating ray paths that undergo reflections from ground and train roof and diffraction from the corner of the train are considered. The measurements verify that the analytical propagation model works very well in typical railway environments. [ABSTRACT FROM AUTHOR]

We present the width dependent study of edge distribution of graphene nanoribbons unzipped from multi-wall nanotubes. The partial unzipping of the carbon nanotubes yields a mixture of carbon nanotubes and nanoribbons. Comparing atomic resolution images of scanning tunneling microscopy with the lattice of graphene, the edge structures of nanoribbons are identified. Below 10 nm, the edges are closer to armchair type. Above 20 nm, the ribbons prefer to have edges close to zigzag type. In between, a more random distribution of the edges is found. The findings are of potential usages for the edge control in graphene nanoribbon based applications. [ABSTRACT FROM AUTHOR]

This paper presents an update for the reliability-based robust geotechnical design (RGD) method in the design of a soil-foundation system by systematically considering four different potential failure modes including: bearing resistance failure of subsoil, excessive foundation settlement, punching and bending failure of the spread foundation. Given the uncertainties in the critical geotechnical and structural parameters, a comprehensive investigation of the reliability and robustness of the soil-foundation system considering both single failure mode and multiple failure modes were conducted in this study. Moreover, the optimal designs of the soil-foundation system with respect to robustness and cost efficiency are found on the premise of satisfying the safety requirements. The results from this study indicate that both the uncertainties of the geotechnical and structural parameters should be taken into account in the RGD of soil-foundation system considering multiple failure modes. Without properly accounting for the width-to-height ratio of the foundation, increase of the footing geometries and the construction cost will not always lead to a safer and robust design. Besides, bearing resistance failure of subsoil has most significant influence on the reliability and robustness of the soil-foundation system and is identified as the control failure mode. [ABSTRACT FROM AUTHOR]

Laterally aligned multilayer GeSi/Si islands grown on a patterned Si (001) substrate are disclosed by selective etching of Si in a KOH solution. This procedure allows us to visualize the vertical alignment of the islands in a three-dimensional perspective. Our technique reveals that partly coalesced double islands in the initial layer do not merge together, but instead gradually reproduce into well-separated double islands in upper layers. We attribute this effect to very thin spacer layers, which efficiently transfer the strain modulation of each island through the spacer layer to the surface. The etching rate of Si is reduced in tensile strained regions, which helps to preserve sufficient Si between the stacked islands to form a periodic array of freestanding and vertically modulated heterostructure pillars. [ABSTRACT FROM AUTHOR]

Site-controlled groups of Ge islands are grown on pit-patterned Si (001) substrates. By varying the deposited amount of Ge, we find that the growth starts with the formation of a single island at the pit bottom and then proceeds to the formation of a highly symmetric Ge island group around the pit top. A bimodal size distribution of dome-shaped islands at the bottom and at the top corners of the pits is observed. A growth mechanism is proposed to qualitatively explain these phenomena. Our experiments help to promote a further understanding of Ge island growth on patterned substrates. [ABSTRACT FROM AUTHOR]

Summary: lncRNAs play crucial roles in fat metabolism in animals. Previously, we have compared the mRNA transcriptome profiles between seven fat‐type Chinese pig breeds and one lean‐type Western breed (Yorkshire, YY). The associations between differentially expressed (DE) genes and phenotypical traits were investigated. In the present study, to further explore the underlying regulatory mechanisms, lncRNAs were sequenced and compared between YY and Chinese indigenous breeds. The results showed 9114 and 7538 DE lncRNAs between at least one Chinese breed and the YY breed in the adipose and muscle tissue respectively. KEGG enrichment analysis revealed that the target genes of these DE lncRNAs mainly influenced the glucolipid metabolism, which is an important process affecting meat quality. Correlation analyses between the DE lncRNA and DE mRNA genes related to meat quality and growth traits were performed. The results showed that LTCONS_00073280 was associated with intramuscular fat content. Four lncRNAs (LTCONS_00101781, LTCONS_00037879, LTCONS_00088260 and LTCONS‐00128343) might mediate backfat thickness. Overall, this study provides candidate lncRNAs that potentially affect meat quality, which might be useful for molecular breeding of pig breeds in future. [ABSTRACT FROM AUTHOR]

To develop a simple and convenient method based on multiparametric magnetic resonance imaging (MRI) and clinical features to non-invasively predict tumour-infiltrating lymphocytes (TILs) in breast cancer (BC) and to explore the relationship between TIL levels and disease-free survival (DFS). A total of 172 BC patients were enrolled between November 2017 and June 2021 in this retrospective study. The patients were divided into high (≥10%) and low (<10%) TIL groups. Clinicopathological data were collected. MRI features were reviewed by two radiologists. Predictors associated with TILs were determined by using multivariable logistic regression analyses. Kaplan–Meier survival curves based on TIL levels were used to estimate DFS. A total of 102 patients with low TILs and 70 patients with high TILs were included in the study. Tumour size (odds ratio [OR], 1.040; 95% confidence interval [CI]: 1.006, 1.075; p= 0.020), apparent diffusion coefficient (ADC; OR, 1.003; 95% CI: 1.001, 1.005; p= 0.015), clinical axillary lymph node status (CALNS; OR, 3.222; 95% CI: 1.372,7.568; p= 0.007), and enhancement pattern (OR, 0.284; 95% CI: 0.143, 0.563; p< 0.001) were independently associated with TIL levels. These features were used in the ALSE model (where A is ADC, L is CALNS, S is size, and E is enhancement pattern). High TILs were associated with better DFS (p= 0.016). The ALSE model derived from multiparametric MRI and clinical features could non-invasively predict TIL levels in BC, and high TILs were associated with longer DFS, especially in human epidermal growth factor receptor 2 (HER2)-positive BC and triple-negative BC (TNBC). • Our study aims to noninvasively assess TILs in BC. • The ALSE model could predict TIL levels, especially in HER2-positive BC and TNBC. • Significantly better DFS was found in high TILs than in low TILs. [ABSTRACT FROM AUTHOR]

The analytical solution of the bending problem for a clamped rectangular plate with a variable in-plane stiffness is found by using the method of superposition. The flexural rigidity of the plate varies across its width according to an exponential function. First, the analytical solution for a simply supported rectangular plate with a variable in-plane stiffness is obtained, and then the bending problem for the plate clamped at its four edges is solved analytically by the superposition of one simply supported plate under the transverse load and two simply supported plates under pure bending. The influence of the variable in-plane stiffness, aspect ratio, and different boundary conditions on the deflection and bending moment is studied by numerical examples. The analytical solution presented here may be helpful for the design of rectangular plates with a variable in-plane stiffness. [ABSTRACT FROM AUTHOR]

When face-centered cubic (FCC) metals and alloys with low stacking fault energy (SFE) are irradiated by high-energy particles or deformed at high speed, stacking fault tetrahedra (SFTs), which are a type of vacancy cluster defect, are often formed. Therefore, SFTs were expected to form in the CoCrFeMnNi equiatomic high-entropy alloy (HEA). However, no SFT was observed in the CoCrFeMnNi HEA with high-speed plastic deformation even after annealing at 873 K. To elucidate this mechanism, the binding energy of vacancy clusters in the CoCrFeMnNi HEA was calculated based on first principles. The binding energy of the di-vacancy cluster was positive (average of 0.25 eV), while that of the tri-vacancy cluster was negative (average of − 0.44 eV), suggesting that the possibility of formation of a tri-vacancy cluster was low. The inability to form a cluster containing three vacancies is attributed to the excellent irradiation resistance of the CoCrFeMnNi HEA. However, if an extra vacancy is added to a tri-vacancy cluster (with negative binding energy), the binding energy of the subsequent tetra-vacancy cluster may become positive. This suggests that it is possible to form vacancy clusters in the CoCrFeMnNi HEA when high-energy ion or neutron irradiation causes cascade damage. [ABSTRACT FROM AUTHOR]

Secondary flux ropes are suggested to play important roles in energy dissipation and particle acceleration during magnetic reconnection. However, their generation mechanism is not fully understood. In this Letter, we present the First direct evidence that a secondary flux rope was generated due to the evolution of an electron vortex, which was driven by the electron Kelvin-Helmholtz instability in an ion diffusion region as observed by the Magnetospheric Multiscale mission. The subion scale (less than the ion inertial length) flux rope was embedded within the electron vortex, which contained a secondary electron diffusion region at the trailing edge of the flux rope. We propose that intense electron shear flow produced by reconnection generated the electron Kelvin-Helmholtz vortex, which induced a secondary reconnection in the exhaust of the primary X line and then led to the formation of the flux rope. This result strongly suggests that secondary electron Kelvin-Helmholtz instability is important for reconnection dynamics. [ABSTRACT FROM AUTHOR]

Hypereutectic 0.8MgO-0.2Y2O3 nanocomposites were studied using high pressure and high temperature in situ synchrotron energy dispersive x-ray diffractometry at 5.5 GPa and 1273 K. Polymorphic transformations in the Y2O3 phase, which resulted in a quadruple phase equilibria among cubic, hexagonal, and monoclinic phases with cubic MgO, were observed at 298 K under 5.5 GPa-a pressure much smaller than the pressures at which polymorphic transitions in macroscopic Y2O3. Time-resolved diffractometry at (1273 K, 5.5 GPa, 120 min) revealed a 0.87% expansive volumetric lattice strain in MgO, and is attributed to solid solution formation with Y2O3 which is otherwise absent at ambient conditions. The residual MgO unit cell volume expansion is 0.69% at 298 K, which is indicative that yttrium remained in solid solution. The macroscopic shrinkage due to densification at (1273 K, 5.5 GPa, 120 min) is 3.45% by volume. The partial molar volume of Y3+ in the solid solution is smaller than its molar volume in the pure state per thermodynamic considerations. The importance of repulsion among O2- ions in the immediate vicinity of a Mg2+ vacancy as well as misfit strain due to differences in ionic radii upon Y3+ substitution on Mg2+ sites is presented. A self-consistent model and explanation for the observed concomitant occurrence of cubic → monoclinic and cubic → hexagonal polymorphic transitions in Y2O3 and their stabilization at room temperature is proposed. [ABSTRACT FROM AUTHOR]

In this paper, the pressure (P) and shear vertical (SV) wave propagation in the periodically layered fluid and piezoelectric structure are theoretically studied. A single piezoelectric layer is first analyzed for three scenarios: piezoelectricity-ignored, electrically open, or electrically closed. It is observed that both the Lamb wave dispersion curves and the transmission coefficients are affected by piezoelectricity and electrical boundary conditions under any incident angle. From the analyses of the periodically layered structure, it is further found that the piezoelectricity and the electrical boundary conditions have influence on band gaps for a given incident angle. [ABSTRACT FROM AUTHOR]

In the solution-assisted laser processing technology, the motion characteristics on the target surface layer have a significant effect on the machining effect. Based on the hydrodynamics, to water-assisted devices in the water-assisted laser processing, the flow field characteristics of the fluid above the target are simulated by Fluent software. The influence of the water layer thickness on the water-assisted laser processing was analysed from the view of the water layer characteristics and the water-assisted laser processing technology was used to optimize by the liquid layer parameters. Simultaneously, the experiment of water-assisted laser processing was carried out, the etching depth, etching width and heat affected zone (HAZ) parameters were tested in the process with different liquid layer thickness, and the reason of the water flow characteristics influence on machining effect was analysed. Water layer flow analysis and experimental studies have shown, the water layer is laminar flow in the water layer thickness of 1 mm, the water layer is the most stable, and it is the most suitable for closed underwater laser processing. At the same time, the experimental results also verify the simulation results of flow field characteristics. This study provides a new idea for selecting the thickness of liquid layer, the location of the workpiece and selecting the inlet speed of fluid in the water-assisted laser processing. [ABSTRACT FROM AUTHOR]

In this paper, the propagation of the shear horizontal wave (SH-wave) in the single piezoelectric layer and periodically layered piezoelectric structure is studied. Both the dispersion equation and transmission coefficients are derived to reveal the wave behavior of the corresponding structures when the piezoelectricity is ignored or the electrical circuit is open and closed. The zero-order mode of the piezoelectricity-ignored single plate is not dispersive and every higher order mode is dispersive with a cut-off frequency. Same features are found for the electrically open and closed cases except that the zero-order mode of the latter case is no more non-dispersive. The pass bands of the piezoelectricity-ignored periodically layered structure appear when the normalized frequency is an even integer under the normal incidence, and new stop bands will appear from the pass bands as the incident angle increases. The same features are observed for the band gaps of the electrically open and closed cases except that the zero-order mode of the latter case is dispersive. The stop bands of the periodic structure will change in a cycle as the geometric ratio increases from zero to one. [ABSTRACT FROM AUTHOR]

Two powerful synchrotron x-ray scattering techniques for residual strain depth-profiling and tomography-like scatter-intensity profiling of materials are presented. The techniques utilize energy dispersive x-ray scattering, from a fixed microvolume, with microscanning of the specimen being used to profile its interior. The tomography-like profiles exploit scattering-cross-section variations, and can be contrast enhanced by separately monitoring scattering from different crystal structures. The strain profiling technique is shown to finely chronicle the internal strain variation over several mm of steel. Detailed strain profiling for a cantilever spring demonstrates the interplay of residual and external stresses in elastic/plastic deformation. Since surface compression, by shot peening, is a classic method to fortify against fatigue failure, the strain profile for a shot-peened, surface-toughened material is determined and discussed in terms of a simple elastic-plastic stress/ strain model. Finally the lattice strains in a WC/Co coated steel composite material are discussed. [ABSTRACT FROM AUTHOR]

We propose a guideline for exploring substrates that stabilize the monolayer honeycomb structure of silicene and germanene while simultaneously preserving the Dirac states: in addition to having a strong binding energy to the monolayer, a suitable substrate should be a large-gap semiconductor with a proper work function such that the Dirac point lies in the gap and far from the substrate states when their bands align. We illustrate our idea by performing first-principles calculations for silicene and germanene on the Al-terminated (0001) surface of Al2O3. The overlaid monolayers on Al-terminated Al2O3(0001) retain the main structural profile of the low-buckled honeycomb structure via a binding energy comparable to the one between silicene and Ag(111). An unfolded band structure derived from the k-projection method reveals that a gapped Dirac cone is formed at the K point due to the structural distortion and the interaction with the substrate. The gaps of 0.4 and 0.3 eV, respectively, for the supported silicene and germanene suggest that they may have potential applications in nanoelectronics. [ABSTRACT FROM AUTHOR]

We present systematic investigation on texture evolution in nanocrystalline Ta under planar shock wave loading at different impact velocities. Seven representative initial textures and two loading directions are studied via large-scale molecular dynamics simulations. Orientation mapping and texture analysis, including orientation distribution functions, pole figures, and inverse pole figures, are performed. Shock compression induces a ⟨ 221 ⟩ texture in nanocrystalline Ta initially with no texture, ⟨ 100 ⟩ fiber texture, { 100 } ⟨ 100 ⟩ texture, and θ + γ rolling texture via twinning, which can be traced back to grains initially with ⟨ 100 ⟩. A ⟨ 100 ⟩ texture is induced via twinning for nanocrystalline Ta initially with no texture, ⟨ 110 ⟩ fiber texture, and α + γ rolling texture and can be traced back to ⟨ 110 ⟩. Dislocation slip and grain boundary sliding lead to the movement of ⟨ 110 ⟩ toward ⟨ 111 ⟩ , and the strengthening of ⟨ 100 ⟩ and ⟨ 111 ⟩ orientation densities. The generation of new textures is observed for most cases. However, no new texture is found in the ⟨ 111 ⟩ fiber texture case for shock loading parallel to the fiber, and a much slower elastic–plastic transition occurs due to the lack of deformation twinning. [ABSTRACT FROM AUTHOR]

A novel rectifier with a considerably extended operating input power range is presented for wireless power transmission applications. The rectifier utilises a depletion‐mode to enhance the diode's breakdown voltage while its built‐in voltage is preserved. As a result, in comparison with traditional rectifiers, this proposed rectifier can achieve a high RF‐to‐DC conversion efficiency in a much wider input power range. Measurement results show that a conversion efficiency of more than 50% can be obtained over the input power range from − 13.5 to 16.7 dBm, proving that this rectifier is suitable for the wireless power transmission applications with varying input power levels. [ABSTRACT FROM AUTHOR]

In this paper, an interface crack between magnetoelectroelastic and orthotropic half-spaces has been studied in detail. By using integral transform techniques the present mixed boundary value problem was reduced to the solution of singular integral equations, which can be further reduced to solving a Riemann-Hilbert problem with closed form solution. The crack-tip singularities of the interface crack have been investigated for possible combinations of the magnetoelectroelastic and orthotropic materials, a criterion based on the coefficient of the Riemann-Hilbert problem is introduced to study the possible singularity behavior of the interface crack, and it is shown that there can be either oscillatory or non-oscillatory singularity for the interface crack depending on the particular combination of the bi-materials. A closed form solution for stresses, electric fields, magnetic fields, electric displacement and magnetic induction in the cracked biomaterials is given, and of particular interests, the analytical expression of the stresses, electric displacements and magnetic inductions along the interface has been obtained. [ABSTRACT FROM AUTHOR]

Presented is the statistical analysis of radio wave propagation in a high-speed railway cutting scenario, derived from 930 MHz measurements taken along the 'Zhengzhou-Xi'an' high-speed railway of China. The crown width and bottom width of the cutting are well-covered by the proposed models. The Ricean distribution offers a good fit and the K-factor is found to be lognormal, with a mean value of 1.88 dB and standard deviation of 3.29 dB. [ABSTRACT FROM AUTHOR]

The development of novel functional materials in experimental labs combined with computer-based compound simulation brings the vision of materials design on a microscopic scale continuously closer to reality. For many applications interface and surface phenomena rather than bulk properties are key. One of the most fundamental qualities of a material-vacuum interface is the energy required to transfer an electron across this boundary, i.e., the work function. It is a crucial parameter for numerous applications, including organic electronics, field electron emitters, and thermionic energy converters. Being generally very resistant to degradation at high temperatures, transition metal oxides present a promising materials class for such devices. We have performed a systematic study for perovskite oxides that provides reference values and, equally important, reports on materials trends and the tunability of work functions. Our results identify and classify dependencies of the work function on several parameters including specific surface termination, surface reconstructions, oxygen vacancies, and heterostructuring. [ABSTRACT FROM AUTHOR]

Abstract: From the literature concerning the traditional nonproportional (NP) multiaxial cyclic fatigue prediction, special attentions are usually paid to multiaxial constitutive relations to quantify fatigue damage accumulation. As a result, estimation of NP hardening effect decided by the entire history path is always proposed, which is a challenging and complex task. To simplify the procedure of multiaxial fatigue life prediction of engineering components, in this paper, a novel effective energy parameter based on simple material properties is proposed. The parameter combines uniaxial cyclic plastic work and NP hardening effects. The fatigue life has been assessed based on traditional multiaxial fatigue criterion and the proposed parameter, which has been validated by experimental results of 316 L stainless steel under different low‐cycle loading paths. [ABSTRACT FROM AUTHOR]

The transparent conducting Ga-Mg co-doped ZnO films were prepared on glass substrates by radio-frequency (rf) magnetron sputtering. The effect of growth temperature on structural, morphological and optoelectronic properties of the films was investigated by XRD, XPS, SEM, UV-visible spectrophotometer and four-point probe. The results show that all the films are polycrystalline and (0 0 2) oriented. The growth temperature significantly affects the structure and optoelectronic properties of the films. The film deposited at the growth temperature of 270 °C has the largest grain size of 52.38 nm, the minimum tensile stress of 0.037 GPa, the highest average visible transmittance of 89.39%, the lowest resistivity of 1.52 × 10 −3  Ω⋅cm and the maximum figure of merit of 5.87 × 10 3  Ω -1 ⋅cm -1 . Furthermore, the optical bandgaps were determined by extrapolation method and observed to be in the range of 3.36–3.59 eV. [ABSTRACT FROM AUTHOR]

Previous research indicated improvement of incubation by light stimuli. However, the light source arrangement, usually with irradiation from top to bottom, was inconvenient and high in cost. Among the different light colors, the effects of green LED light stimuli during embryo development were inconclusive. In this study, two LED lamps were installed on both sides of egg trays, and the irradiation was directed from the edges to the middle. The effect of green LED light with various light intensities was investigated. A total of 1408 broiler eggs were randomly allocated to high light (300 lx), middle light (150 lx), low light (50 lx), and dark treatments with four replicates. Embryo weight, body length, organ weight, hatching performance, and serum hormone levels were tested. The results indicated that incubation of the broiler eggs under an appropriate light intensity (low light treatment, 50 lx) of green light significantly increased embryo weight, body length, and hatchability (p < 0.001). According to the serum hormone tests, only the low light treatment significantly increased the thyroxine (T4) levels of the chicks (p < 0.05) at hatching, but the middle and high light treatments slightly decreased the T4 and testosterone (TES) levels of the chicks compared with the dark treatment. Moreover, peak hatching time occurred 12 h earlier in the light treatments compared with the dark treatment. In conclusion, an appropriate light intensity (low light treatment, 50 lx) of LED green light improved embryo growth and hatching performance, but excessive light intensity reduced the positive effects or even produced slight negative effects on the T4 and TES levels of chicks at hatching. [ABSTRACT FROM AUTHOR]

A methodology is presented to characterize the crystallographic texture of atomic configurations on the basis of Euler angles. Texture information characterized by orientation map, orientation distribution function, texture index, pole figure and inverse pole figure is obtained. The paper reports the construction and characterization of the texture of nanocrystalline configurations with different grain numbers, grain sizes and percentages of preferred orientation. The minimum grain number for texture‐free configurations is ∼2500. The effect of texture on deducing grain size from simulated X‐ray diffraction curves is also explored as an application case of texture analysis. In addition, molecular dynamics simulations are performed on initially texture‐free nanocrystalline Ta under shock‐wave loading, which shows a ⟨001⟩ + ⟨111⟩ double fiber texture after shock‐wave compression. [ABSTRACT FROM AUTHOR]

Vortex induced vibration based energy harvesting systems have gained interests in these recent years due to its potential as a low water current energy source. However, the effectiveness of the system is limited only at a certain water current due to the resonance principle that governs the concept. In order to extend the working range, a bistable spring to support the structure is introduced on the system. The improvement on the performance is essentially dependent on the bistable gap as one of the main parameters of the nonlinear spring. A sufficiently large bistable gap will result in a significant performance improvement. Unfortunately, a large bistable gap might also increase a chance of chaotic responses, which in turn will result in diminutive harvested power. To mitigate the problem, an appropriate control structure is required to stabilize the chaotic vibrations of a VIV energy converter with the bistable supporting structure. Based on the nature of the double-well potential energy in a bistable spring, the ideal control structure will attempt to drive the responses to inter-well periodic vibrations in order to maximize the harvested power. In this paper, the OGY control algorithm is designed and implemented to the system. The control strategy is selected since it requires only a small perturbation in a structural parameter to execute the control effort, thus, minimum power is needed to drive the control input. Facilitated by a wake oscillator model, the bistable VIV system is modelled as a 4-dimensional autonomous continuous-time dynamical system. To implement the controller strategy, the system is discretized at a period estimated from the subspace hyperplane intersecting to the chaotic trajectory, whereas the fixed points that correspond to the desired periodic orbits are estimated by the recurrence method. Simultaneously, the Jacobian and sensitivity matrices are estimated by the least square regression method. Based on the defined fixed point and the linearized model, the control gain matrix is calculated using the pole placement technique. The results show that the OGY controller is capable of stabilizing the chaotic responses by driving them to the desired inter-well period-one periodic vibrations and it is also shown that the harvested power is successfully improved. For validation purpose, a real-time experiment was carried out on a computer-based forced-feedback testing platform to validate the applicability of the controller in real-time applications. The experimental results confirm the feasibility of the controller to stabilize the responses. [ABSTRACT FROM AUTHOR]

Context: Many individuals involved with care of the dying advocate expanding access to hospice care for persons with advanced lung, heart, or liver disease. However, to be eligible, these patients generally must have a prognosis for survival of less than 6 months.Objective: To test the ability of currently available criteria to identify a population with a survival prognosis of 6 months or less among seriously ill hospitalized patients with 1 of 3 commonly fatal chronic diseases.Design: Validation study using data from the Study to Understand Prognoses and Preferences for Outcomes and Risks of Treatments (SUPPORT) phase 1 (June 1989-June 1991) and phase 2 (January 1992-January 1994), with a 6-month follow-up.Setting and Patients: Consecutive sample of 2607 seriously ill patients from 5 US medical centers who were hospitalized with chronic obstructive pulmonary disease, congestive heart failure, or end-stage liver disease, and who survived to hospital discharge.Main Outcome Measures: Descriptive and operating characteristics of 5 general and 2 disease-specific clinical criteria for identifying patients with a survival prognosis of 6 months or less, and 3 sets of combination criteria (broad, intermediate, and narrow inclusion) aimed at providing low, medium, and high thresholds for hospice eligibility based on National Hospice Organization guidelines.Results: Seventy-five percent of the sample survived more than 6 months after hospital discharge; 44% expressed a preference for palliative care. Broad inclusion criteria identified 923 patients eligible for hospice care, of whom 70% survived longer than 6 months. Intermediate inclusion criteria identified 300 patients, of whom 65% survived longer than 6 months. Narrow inclusion criteria identified 19 patients, of whom 53% survived longer than 6 months. Sensitivities and specificities of the combination criteria were 41.7% and 66.7% (broad inclusion), 16.2% and 90.1 % (intermediate inclusion), and 1.4% and 99.5% (narrow inclusion), respectively.Conclusions: These data indicate that for seriously ill hospitalized patients with advanced chronic obstructive pulmonary disease, congestive heart failure, or end-stage liver disease, recommended clinical prediction criteria are not effective in identifying a population with a survival prognosis of 6 months or less. [ABSTRACT FROM AUTHOR]

The borrowing of historical control data can be an efficient way to improve the treatment effect estimate of the current control group in a randomized clinical trial. When the historical and current control data are consistent, the borrowing of historical data can increase power and reduce Type I error rate. However, when these 2 sources of data are inconsistent, it may result in a combination of biased estimates, reduced power, and inflation of Type I error rate. In some situations, inconsistency between historical and current control data may be caused by a systematic variation in the measured baseline prognostic factors, which can be appropriately addressed through statistical modeling. In this paper, we propose a Bayesian hierarchical model that can incorporate patient-level baseline covariates to enhance the appropriateness of the exchangeability assumption between current and historical control data. The performance of the proposed method is shown through simulation studies, and its application to a clinical trial design for amyotrophic lateral sclerosis is described. The proposed method is developed for scenarios involving multiple imbalanced prognostic factors and thus has meaningful implications for clinical trials evaluating new treatments for heterogeneous diseases such as amyotrophic lateral sclerosis. [ABSTRACT FROM AUTHOR]