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Background The femoral anterior tangent (FAT) line refers to a line parallel to the anterior surface of the distal femur in the axial plane. This study aimed to evaluate the effectiveness of a new operation support system which uses the FAT line to set the femoral component rotational alignment in total knee arthroplasty (TKA). Methods A total of 170 consecutive knees in 139 patients undergoing primary TKA with the JIGEN (Jig Engaged Three-dimensional (3D) Pre-Operative Planning Software for TKA) operation support system was examined. The JIGEN system creates 3D models of bones using computed tomography data, allowing for surgical simulations such as positioning of implants while calculating positions of the intramedullary alignment rod (IM rod) and surgical jig. We retrospectively analyzed the FAT line angle relative to the surgical epicondylar axis (SEA) on the axis plane perpendicular to the IM rod and evaluated the accuracy of the femoral component alignment after TKA with the 3D measurement system. Results The FAT line was 9.6° ± 3.7° (range, 1.4°–20.4°) internally rotated relative to the SEA. The average absolute error was 1.4° ± 1.1° in the coronal plane, 2.0° ± 1.5° in the sagittal plane, and 1.6° ± 1.3° in the axial plane. The femoral component outliers (i.e., >3° away from the goal alignment) were 7.7% in the coronal plane, 20.6% in the sagittal plane, and 10.3% in the axial plane. Conclusions Our findings suggest that the FAT line is a reliable and reproducibly identifiable axis for the accurate determination of proper rotational alignment in TKA. An operation support system which uses the FAT line for determining intraoperative femoral component rotation can effectively achieve highly accurate positioning of the femoral component in TKA.

Surface microtexturing accomplishes a substantial role in enhancing the interfacial functional performance of machine-driven components. For producing good-quality square micropatterns, maskless electrochemical micromachining (EMM) is a viable option. Maskless EMM is employed for producing micropatterns, wherein the workpiece remains close by interaction with the mask tightly enclosed to the coated tool surface, and the electrolysis of job involves in the enclosed cell. The special micropatterning setup is developed to produce the good quality square micropatterns including micropatterning cell, pulsed electrical unit and perpendicular cross flow electrolyte system. The developed flow method on the job surface in this unit produces better good quality micropatterns. A reused textured tool and developed flow method is applied in maskless EMM in an enclosed unit, which eradicates the sludges and fabricate micropatterns with higher depth. This unique method is an efficient approach for improving the dimensional accuracy of micropatterns. The influences of input criteria, viz. voltage, duty ratio and frequency are studied on surface roughness, current efficiency, length overcut, and textured depth using this technique. The experimental outcomes show that the best parametric combination, viz. 30% duty ratio, 5 kHz frequency and 8 V voltage, enhances the micropatterned quality. A study has been approached based on micrographs for attaining the best input criteria combination.

Reasonable laser process parameters and heating paths are crucial in laser forming (LF) technology. Obtaining the proper laser processing parameters and the heating path is the decisive factor to determine the forming efficiency and precision of the complex 3D surfaces with double curvature. First, the 3D target surfaces with double curvature were developed in this paper to flat plates through the finite element numerical simulation tool, and the magnitude and direction of in-plane and bending strains were obtained; the direction perpendicular to the principal strain is the direction of the heating paths. Second, the database of laser process parameters and principal strains was established to determine the proper laser process parameters. Finally, combined with the above laser parameters and heating paths, the “pillow” and “spherical” surfaces were obtained, and the accuracy of this method was verified by experiments.

This paper focuses on transverse crack detection and its depth estimation in the shaft by applying extrinsic excitation for an overhung rotating shaft system. The dynamics of overhung rotating shaft system with six different shafts having different crack depth parameters are studied experimentally and through the finite element method (FEM). Variation of natural frequencies with crack depth parameters is studied using FEM through ANSYS. The practical application of axial extrinsic excitation is employed to an overhung rotating shaft system for spectrum analysis in two mutually perpendicular directions. The comparison of spectrum for healthy and cracked overhung rotating shaft system shows the appearance of distinctive peaks for cracked rotor system along with 2X component which is major for crack detection. The appearance of peaks at the summation of extrinsic excitation frequency plus rotational frequency along with extrinsic excitation frequency and its harmonics provides an early warning of the crack in the rotor system. The amplitude of these peaks also increases with the crack depth parameter, which estimates crack depth in the shaft. The approach presented in this paper can be very well adapted for crack detection and estimate its depth in the overhung rotating shaft system during its operation.

A low-loss all-straight optical fiber vector magnetic field sensor (OFVMS) based on magnetic fluid (MF) is designed and proposed. The sensing structure is composed of a Section of the C-type optical fiber (CTF) embedded in a pair of multi-mode optical fibers (MMF) and wrapped in a capillary with MF. The asymmetry of the CTF provides support for the vector magnetic field measurement whose direction is perpendicular to the optical transmission direction. According to the results of experiments, it can be obtained that the refractive index (RI) sensitivity of the sensing structure is as high as −15716.6072 nm/RIU. In addition, the intensity sensitivity of the OFVMS in the calibrated 90° direction can reach 202.23 pm/G between 0 and 123 G. At the same time, the transmission loss of the proposed sensor structure is not increased by the filling of MF. The sensor demonstrated has dominance in low cost, easy manufacture, and lower loss compared with the same type of sensor device, which has application prospects in vector magnetic field sensing.

A miniature wide-range three-axis vector atomic magnetometer under spin-exchange relaxation-free regime has been developed. With a cylindrical vapor cell of size 10 mm in diameter and length, we have constructed a single-beam configuration through a polarization-maintaining fiber carrying the laser beam to the sensor and a multimode fiber guiding the transmitted light field to the photodiode. A rotating field on the plane perpendicular to the direction of propagation of the laser and another modulation field in the pump direction, which are generated in the field programmable gate array using direct digital synthesis to measure the three components of the magnetic field simultaneously. The spin-exchange relaxation is suppressed in zero field controlled by a feedback system, thus a wide range and excellent accuracy of three-axis vector atomic magnetometer response is obtained. Consequently, the transverse magnetic field sensitivity of 350 fT/Hz1/2 and longitudinal field sensitivity of 3pT/Hz1/2 are achieved with a dynamic range of 60000 nT. This sensor with compact size, wide range and high sensitivity is particularly suitable for geomagnetic observatory and space exploration.

In this paper, a two-dimensional wireless displacement sensor with high sensitivity composed of a bilayer graphene-based frequency selective surface (FSS) is proposed. The lengths of the strip-type resonators on the top and bottom layers of the FSS are different and perpendicular to each other. Based on the resonance and polarization characteristics of the FSS, two-dimensional displacement sensing can be realized. It is well validated both in simulation and experiment that the direction of the displacement can be distinguished by the variation trend of the resonant frequencies of the top and bottom layers. In experiment, the measured results of the FSS based wireless displacement sensor in the dynamic range of 5mm show high sensitivity of 280 MHz/mm in x direction and 370 MHz/mm in y direction. Moreover, the excellent mechanical and chemical stability of the multi-layer graphene also makes it suitable for harsh environments, showing good prospects in application.

The current paper deals with the problem of the simply supported thin rectangular plate subjected to the intermediate strip in-plane loading. Based on the strain energy method (Fourier ansatz), the critical (minimum value) of buckling stress occurrence was determined in a general form dependent only on the strip thickness, strip location, plate width and stress magnitude. Compatible with the classical columns Euler method it was found that the plate stability is decreased with the increasing of the plate width due to larger induced stresses. Also, strip location relative to the support region was found to influence the buckling (same analogy to the Euler buckling theory; consider the strip as a both sides pressed rod). Additionally, the strip width parameter increase is likely to cause larger buckling stress. Moreover, expressions that includes both axial and transverse loads for different extended cases configurations were also derived and examined based on the strain energy method alongside explanation for possible applications (thin aluminum plate welding). In a general view, it was found that the cases of combined axial and perpendicular loading action are less stabilized than cases where only one kind of loading configuration is participated. Finally, the buckling stress was found to agree qualitatively with the cited literature.

The growth characteristic of primary faceted Al2Cu intermetallic compounds (IMCs) during solidification was observed directly by synchrotron radiography. The formation and transition mechanisms of Al2Cu IMCs with diverse morphologies were elucidated by first-principle calculations combined with electron backscatter diffraction analysis. The Al2Cu crystals preferred to grow along the [001] direction and were bounded by {110} planes with the lowest surface energy. The faceted Al2Cu rod-like clusters consisted of multiple crystals with complete rod, hollowness and partial sides, which was attributed to the increase in strain energy and solute redistribution during solidification. The faceted Al2Cu with branches was characteristic with the perpendicular relationship between the main branches and side steps and partial coalescence at the junction, which was ascribed to the continuous propagation and growth of newly formed crystals along the diagonal direction.

In general, pulsed lasers with high peak power have been used for the micro-groove formation. However, the processing speed is limited by the pulse repetition rate. On the other hand, CW laser can be expected to perform the high-speed processing by continuous energy input. The mechanism of micro-groove formation by CW laser was investigated by high-speed observation and the thermal fluid analysis. In the perpendicular irradiation of CW laser, the molten metal flows symmetrically around the keyhole to the backward direction, and micro-grooves remain at both edges of molten region. In contrast, in the angled irradiation, the molten metal at the reflection-side scatters as spatters. The remained molten metal flows from the reflection-side to the incident-side through the bottom of keyhole, since the recoil pressure is generated from the reflection-side to the incident-side. In addition, high-speed scanning contributes to keeping the sufficient time and force to move the molten metal in the backward direction. Then, the micro-groove remains at the reflection-side, while the upheaval is formed at the incident-side by gathering the molten metal from the reflection-side and the front of keyhole. Asymmetrical behavior of molten metal flow in angled irradiation of CW laser can create micro-groove in the reflection-side.

Pristine carbon nanotubes (CNTs) and functionalized carbon nanotubes (f-CNTs) were introduced into conductive poly(methyl methacrylate)/graphene nanoplatelet (PMMA/GNP) composites to achieve a synergistic effect in the enhancement of the conductivity and the reduction in the percolation threshold by forming a 3-Dimensional(3-D) hybrid structure. Both the in-plane and perpendicular electrical properties were investigated. The synergies of hybrid fillers in the in-plane direction were more dependent on the total filler loading, while those in the perpendicular direction were significantly influenced by the GNP/CNT or GNP/f-CNT ratios. Typically, a schematic diagram of the evolution of the 3-D conductive pathways of PMMA/GNP/f-CNT composite at different GNP/f-CNT ratios was presented to explain this phenomenon. Moreover, tunable conductivity anisotropy (defined as the ratio of in-plane conductivity to perpendicular conductivity) ranging from 0.01 to 1000 was achieved, simply by constructing different conductive structures at various filler loadings or ratios in composites. Graphical abstract The synergistic effect of GNPs and f-CNTs varies with the microstructural conductive network evolution at different filler ratios.

Purpose X‐ray imaging devices contain a collimator system that defines a rectangular irradiation field on the detector plane. The size and position of the X‐ray field, and its congruence with the corresponding light field, must be regularly tested for quality control. We propose a new method to estimate how far the x‐ray field extends beyond the detector which does not require the use of external detectors. Methods A metallic foil is inserted perpendicularly between the source and the detector. A slit camera, a linear extension of a pinhole camera, is used to project onto the detector the fluorescence X‐rays emitted by the irradiated foil. The location where the fluorescence signal inside the camera vanishes is used to extrapolate the location of the field boundary. Monte Carlo simulations were performed to determine the optimal composition and thickness of the foil. A prototype camera with a 1‐mm‐wide slit was built and tested in a clinical mammography and digital breast tomosynthesis (DBT) system. Results The simulations estimated that a foil made of 25 µm of Molybdenum provided the maximum signal inside the camera for a 39 kVp beam. The boundary of the X‐ray fields in mammography and DBT views were experimentally measured. With the camera along the chest wall side, the measured field in multiple DBT views had a variability of only 0.4 ± 0.1 mm compared to mammography. A difference in the measured boundary position of 2.4 and –1.0 mm was observed when comparing to measurements with a fluorescent ruler and self‐developing film. Conclusion The introduced technique provides a practical alternative method to detect the boundary of an X‐ray field. The method can be combined with other testing methods to assess the congruence of the X‐rays and light fields, and to determine if the X‐ray field extends beyond the detector more than permitted.

Laser powder bed fusion (LPBF) provides fine spatial resolution for additively manufactured (AM) objects. Development of a new LPBF machine technology enables the incorporation of multi-directional compositional gradients. A sample with six compositional regions ranging from 100% titanium to 100% tantalum perpendicular to the build direction was produced, while also changing the processing parameters for the different material composition. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were used to observe both the bulk and interface regions. SEM images demonstrate that dendritic morphology is present as a result of the non-equilibrium solidification instead of the one-phase solid solution predicted from the equilibrium phase diagram. EDS line and area scans indicate diffusional segregation of tantalum away from the interface regions. The ability to functionally grade material composition in multiple directions using LPBF AM provides the capability to fabricate complex geometries with spatially varying properties tailored to the desired application.

A complementary source array with enhanced beamwidth is presented based on the substrate-integrated waveguide (SIW) in this communication. The orthogonal complementary source consists of a SIW slot and a vertical monopole, of which the radiation pattern is heart-shaped, pointing to the direction perpendicular to both slot and monopole. To achieve an enhanced beamwidth from the heart-shaped pattern, the complementary sources are cascaded to form an array. In particular, the slots are etched alternately on both sides of the central axis to achieve an in-phase excitation, while the monopoles are uniformly loaded with an alternate antiphase excitation. This arrangement makes the heart-shaped pattern of each complementary source element alternately point to either side of the array axis, so that the synthesized radiation beamwidth is enhanced in the E-plane. Based on the proposed idea, a nine-element line array is designed, fabricated, and tested. Compared with the same-sized referenced SIW slot array with an E-plane half-power beamwidth (HPBW) of only 80°, the proposed complementary source array extends the HPBW to 180°.

A new electromagnetic band gap (EBG) structure based on the soft and hard surfaces for gap waveguide (GW) technology is introduced in this article. The proposed EBG structure consists of a soft surface and a hard surface in parallel with a gap between them, where the ridges/corrugations of the two surfaces are perpendicular to each other or with an angle near 90°. Compared with the contactless bed of nails EBG, the most widely used EBG structure in GW technology, the structural strength of the new EBG structure is increased significantly, which makes it very suited for high-frequency applications. Another advantage is that with the varying of the angle between the ridges/corrugations of the two surfaces, the stopband shifts in a wide frequency band, which makes the stopband tunable after the EBG is fabricated. The stopband performance of the proposed EBG is investigated. Straight and bended groove GWs (GGW) employing this new EBG are designed, manufactured and tested. The isolation performance with different columns of ridges/corrugations is also tested. The measured results show the proposed GGWs have excellent transmission performance.

Welding induced buckling in thin plate structures significantly affects productivity and fabrication cost due to post-weld correction works. Transient thermal tensioning (TTT) as an in-process treatment was employed for mitigating welding induced buckling, and its mechanism was clarified by inherent strain theory. Butt welding experiment with 304 L stainless steel was conducted. A finite element (FE) model was established to examine thermal-mechanical response during the entire welding process. Computed results were validated by the measured out-of-plane welding distortion, which was obtained using a three-dimensional optical scanning system. Then, two additional heat sources on both sides of the welding line were applied to achieve TTT treatment with the established numerical model. Moreover, the influence of heating location on mitigating welding induced buckling was discussed. The results show that the maximum deflections along and perpendicular to welding direction were reduced by 82.6% and 74.7%, respectively. The heating location has a decisive influence on the mitigation of welding induced buckling, which should be kept away from the welding line with appropriate distance. The thermal stretching from additional heat sources enhances the self-constraint of the base material on the welding region during the cooling process, resulting in more tensile plastic strain generated to reduce welding inherent strain and tendon force.

Electromagnetic pulse welding (EMPW) is of increasing interest for industrial applications because of its advantages in dissimilar metals welding. During the EMPW process, the flyer plate is driven by the Lorentz force to impact the parent plate. The dynamic behavior of the flyer plate has been investigated in this work, based on the 3D finite element simulation, deformation experiment, and welding experiment of Cu/Al plates. And it can be divided into three stages: the deformation stage, collision stage, and expansion stage. There are two movement directions of the flyer plate, one is parallel to the welding direction, another is parallel to the coil direction, and the two directions are perpendicular each other. The welding also extends from the first collision point to the outside and the end, forming an elliptical welding ring seam gradually. When the discharge voltage is lower than 14 kV, the welding ring is not closed at the end, and when the discharge voltage is higher than 14 kV, the welding ring is closed. The simulation results are in good agreement with the experiment results.

Dielectric material is an important material for film capacitors. However, the progress of this material is either impeded by its low dielectric constant, high loss tangent, or insufficient flexibility. In this work, PVA/GO film with alternating layer structure was fabricated by Spin-Coating-Assembly (SCA) method. This alternating layer structure not only benefits forming numerous microscale capacitors which improve e value a lot, but also helps eliminate perpendicular contact of GO and prevents the formation of conductive pathways. Thus, compared with pure PVA, significantly increased dielectric permittivity and a low loss tangent were simultaneously observed for the PVA/GO film. The ratio of dielectric permittivity to loss tangent increased from 68 to 165. These films might be potential flexible dielectric materials for advanced electrical devices such as embedded capacitors.

This research is a development of previous research, where in the previous research, a design innovation was carried out on an alpha-type stirling engine by making the phase angle to 180o, with the aim of reducing the effect when the cold cylinder is compressed, because the phase angle currently used is (90o) with disadvantages, namely the cold cylinder is perpendicular to the top, so that the compression process against gravity. But in previous studies, the generator pipe was too long, causing a lot of energy or heat loss (heat loss) so that the compression speed was small. So that in the research, innovated and analyzed the pipe insulation of alpha-type stirling engine generators, alpha-type stirling engines, 180o phase angle. The research method used is to use the thermodynamic approach with Schmidt theory and the theory of the ideal cycle stirling engine. while the simulation is done using the Ideal Stirling Cycle Calculator. Results investigated shows that providing insulation on the generator pipes of an alpha-type stirling engine for an alpha-type stirling engine with a 180o phase angle is proven to reduce a lot of energy or heat loss (heat loss) due to too long generator pipes, with a heat loss value ratio of 226.66 W for the pipe. generator that uses insulation whose value is smaller than the value of the heat loss when the generator pipe without using isocation is 1,584.12 W.

An experimental system, which consists of a digital camera and a loading system, is designed to investigate the failure mechanism of anti-dip rock slopes subjected to external loading. The modeling material is made by mixing sand, plaster, barite, glycerin, and water at a mass ratio of 44.4:30:22.5:2:32. Fine sand is evenly filled between the rock layers to simulate the joints of the anti-dip rock slopes. Anti-dip rock slope models with joint angles of 45°, 55°, 65°, and 75° are poured in the experiment. The complete load–displacement curves of the anti-dip rock slopes subjected to external loading are obtained to investigate the effects of the joint angle on the ultimate bearing capacities of the slopes. Based on the images captured by the digital camera under the high-speed shooting mode, the whole failure process of the anti-dip rock slopes is analyzed, including the crack evolution. Moreover, an image processing technique is proposed to capture the displacement vector diagrams of anti-dip rock slopes and the real-time deformation behavior of anti-dip rock slopes is investigated. The ultimate failure modes of the anti-dip rock slopes with different joint angles are discussed in detail. The sliding body is separated from the slope along the datum plane, which is always perpendicular to the slope joints. Failures occur at the top of the anti-dip rock slopes (near the external loading), while the bottom of the slopes remain intact. Based on the experimental results, the failure mechanism of the sliding blocks in the anti-dip rock slopes is revealed. The experimental results can be expected to assess the failure mode of anti-dip rock slopes subjected to external loading.

This paper is a report on the design and fabrication of a dual-axis micro-opto-electro-mechanical system (MOEMS) accelerometer. The device consists of a proof mass (PM) suspended by four L-shaped springs. Two Fabry-Perot (FP) cavities are formed between the cross-sections of the PM and the ends of two cleaved optical fibers in perpendicular directions (the X and Y axes). The acceleration causes the proof mass to move in the reverse direction relative to the applied acceleration. The sensor is fabricated by a silicon-on-insulator wafer. The fabricated sensor is characterized both by spectral monitoring and power measurements in the range of ±1 g. The results of spectral measurements show 3.23 nm/g (g = 9.81 m/s2: gravity constant) and 3.19 nm/g to the applied acceleration along the X and Y axes, respectively. Moreover, the obtained resolutions for the two directions of X and Y are $309~\mu \text{g}$ and $313~\mu \text{g}$ , respectively. Besides, the sensitivity of the sensor in power measurements is 550 mV/g and 528 mV/g in the X and Y directions, respectively. The sensor also possesses the resonant frequencies of 1382.5 Hz and 1398.6 Hz in the X and Y axes, respectively, in the range of ±1 g. The maximum cross-axis sensitivities obtained for this sensor are below 0.19% for each pair of X, Y, and Z axes. This value is fewer than the cross-axis sensitivity of most micro electro-mechanical systems without any post processing. This small value is a result of insensitivity of the FP spectrum to the lateral displacements of the PM.

An earlier version of this paper was presented at the IEEE Sensors 2020 conference and was published in its Proceedings with the title “Aerodynamic wall pressure measurement using a high temperature gradient Pirani micro-sensor” (DOI: 10.1109/SENSORS47125.2020.9278842); International audience; This paper presents and discusses the first demonstration of aerodynamic wall pressure measurement using a thermal Pirani effect based micro-sensor. The thermal micro-sensor is designed as a suspended micro-hot-wire separated from the substrate by a nanoscale gap, and mechanically supported by perpendicular micro-bridges. The micro-sensor was calibrated for pressure measurement from 10 kPa to 800 kPa. It was then used as aerodynamic wall pressure sensor in a turbulent boundary layer wind tunnel and successfully measured the 1.1 kPa depression occurring in the wind tunnel when the flow velocity goes up to 40 m/s.

The fracture behavior of bamboo culm under three-point bending has been studied using a micromechanical tester in conjunction with an optical microscope which enabled in situ observation of crack initiation and propagation in the microarchitecture of fiber bundles, parenchyma cells, and vascular bundles. Fiber orientation was found to strongly influence the bamboo’s fracture behavior. When loading was orientated along fiber bundles, fracture occurred in a brittle manner, whereas when loading was applied perpendicular to fiber bundles, cracks propagated in a trans-parenchyma cell manner accompanied by crack bridging and fiber pulling-out. The cracks preferred to propagate in the fashion of trans-parenchyma cells and inter-fibers. The findings inform future simulation and modeling with correct boundary conditions and parameters, and provide additional design guidelines for developing high-performance bamboo-like composites.

10.1119/10.0003796.1A ball placed inside a hollow cylinder and spun around an axis perpendicular to the cylinder wall will roll back and forth along the cylinder wall, as expected, but it will also oscillate along the axial direction of the cylinder. These axial oscillations occur in horizontal, tilted, and even vertical cylinders. Here, the equations of motion for this setup are derived and discussed, and experimental results are presented along with a discussion of the observed energy losses.

Objective: In this study, we investigate the performance of a flexible microwave ablation antenna for generating localized ablation zones. Methods: We designed a helical dipole antenna to operate at 1.9 GHz in egg white and liver. Semi-rigid prototypes of the antenna were fabricated and used to perform ablation experiments in egg white and perfused liver. Pulsed and continuous-wave power deliveries at different power levels were used. Flexible prototypes of the antenna were fabricated and used to perform ex vivo ablation experiments in perfused liver. Results: Pulsing was effective in reducing the shaft heating of semi-rigid cables. The antenna was capable of producing substantial ablation zones in perfused liver. Typical diameters (perpendicular to the antenna axis) of generated ablation zones with semi-rigid antennas in egg white and perfused liver were 30 mm and 20 mm, respectively. The flexible antenna had a good impedance match while bent. Average diameter of generated ablation zones by the flexible antenna with 10-W continuous-wave experiments in perfused liver was 26 mm. No significant difference was observed between the performances of semi-rigid and flexible prototypes. Conclusion: The flexible helical dipole antenna is capable of maintaining its good impedance match while bent and can generate substantial ablation zones in presence of perfusion. Significance: The proposed flexible antenna is promising for minimally invasive treatment of tumors that are otherwise inaccessible by rigid antennas. One example is lung where a catheter-based deployment of the flexible antenna into the tumor via airways may substantially reduce risks associated with using rigid antennas.

Detailed analysis and characterization of injection-molded polypropylene (PP) specimens produced with laser-textured molds has been performed. Ultrashort pulsed laser surface structuring was exploited to produce sub-micrometric surface features on injection molds over areas of 2400 mm2, including two-dimensional hole and cone arrays, and ridges parallel and perpendicular to the injection direction. Replication effectiveness was evaluated in terms of surface roughness parameters, Filling Volume Fraction (FVF) and Power Spectral Density (PSD), after which detailed comparison of the topography in the same region on plastic samples and molds was performed. A scatterometry setup was employed based on optical diffraction of a probe laser beam to assess replication fidelity over the entire surface of each PP sample with a measurement technique suitable for optimization and quality control in an industrial production environment. Of the tested surface morphologies, greatest replication effectiveness was achieved with LIPSS oriented parallel to the injection direction, where the arithmetic mean height of plastic samples (Sa = 37 ± 4 nm) was 97 % of the corresponding value of the mold (Sa = 38 ± 6 nm), while the average FVF was 86 ± 9 % and the PSD indicated ripple-like features with a spacing of λ ≃ 0.9 μm. Direct comparison of the topography in selected regions highlighted local variability in the transfer effectiveness of individual surface features. The investigation demonstrated that micro and nanoscale morphology can effectively be transferred via injection molding over large areas relevant to industrial applications, while careful attention must be paid to the size and nature of defects in relation to the specific functional surface under consideration.

This paper presents a new linear eddy current speed sensor with rectangular-shaped coils. The excitation coil and the pick-up coil have a perpendicular configuration without a magnetic yoke. The proposed sensor is shorter than the previous designs. The sensor works for a conductive moving target; in this paper we present calculations and an experimental verification for solid iron and aluminum moving part materials. A novel 3D analytical method is presented for the description and for the design of an eddy current speed sensor that is fast and has high precision. The source fields and the reaction fields caused by induced eddy currents are separated in our 3D analytical method, which facilitates an enhanced investigation of the features of the speed sensor. Evaluations of the effects of the moving part material and of coil lift off on the performance of the speed sensor are made with the use of a 3D analytical method. Measurements are performed for an eddy current speed sensor at different speeds up to 11.65 m/s and at different frequencies with a novel analytical model in terms of the induced voltage in the pickup coil versus speed. Simplicity and high precision are the main advantages of the proposed speed sensor. The achieved linearity error is 0.47% (measured) up to 11.6 m/s, and 0.43% (calculated) up to 117 m/s (420 km/h).

For the robotic GMAW on complex surface, the welding position is various along the welding path at different region, which results in the diverse molten pool behaviors, forming appearance or even the defects. To investigate the molten pool behaviors and forming appearance on the complex surface, the welding pose on the surface was described, the computational fluid dynamics model of the weld pool considering the droplet impingement, gravity, arc force, heat and mass transfer for four typical welding position was developed. The influence of gravity on the fluid flow for different position was investigated, and the results were validated with the high-speed welding camera. The deposition experiments with different welding current and local inclined angle were conducted to analyze the influence of the welding parameters and surface geometrical structure on the forming appearance. The results indicated that the influence of the gravity on the flow field and forming appearance at various welding position was different. The effect increased with the welding current, the surface local inclined angle (α∈[0, 90°]), and the absolute value of speed angle (|β|∈[0, 90°]), which was minimized when the torch travel direction was perpendicular to the gravity (β = 0°), because of the attenuated influence on the backward fluid flow. The findings help explain the molten metal forming mechanism of the welding on complex surface and improve the forming appearance.

The dendritic growth transition of nickel-based superalloy in the top region of the laser additive manufactured layer has been studied. The results show that the dendritic growth direction in the top region of the layer is changed from the perpendicular to parallel direction to the laser scanning direction. From the finite element simulation, the dendritic growth transition is found to be attributed to the increased deviation angle between the epitaxial dendritic growth direction and local thermal gradient in the top region of the molten pool. The critical transition angle is revealed to be 70°–80°. The origin of the top transition grains is mostly the re-nucleation sites generated in the last remaining liquid in the top region of the molten pool.

The equations for calculating the velocities of a fluid and its pressure on a radial-axial flow turbine blade with variation of slope angle of individual blade sections are refined. The velocities of the fluid oriented perpendicular to the blade plane and in tangential and radial directions and the pressure of the fluid in tangential direction are expressed for a radial-axial flow turbine by similar equations and differ only in slope angles of the blade sections. The equations for determining the pressure in the direction perpendicular to the blade plane and in radial direction differ in both slope angles of the blade sections and in calculating equations.

The concern plate’s behavior was the growth of the extrema positive tensors of both mean (hydrostatic) and deviatoric moments. Systematic consideration of the limits and growth responses of the mean and deviatoric tensors at the extrema positive sections were calculated. It was found that the use of the shorter dimension for the moment normalization in both directions preserves the directional influence of the dimensions and isolates clearly the hydrostatic phenomenon. Moreover, the presence of non-identical boundary conditions in the plate on two perpendicular directions was found to result in the deviation of the two-way action of behavior. Consequently, a novel understanding of the two-way plate action has been achieved. In such understanding, the pure two-way action accompanies the occurrence of a hydrostatic curvature (or moment) at a plate’s extrema positive point. At the later state, the hydrostatic and deviatoric tensor components would be equal. Based on linear and multi-Stage regression analysis, the growth of the normalized hydrostatic moment component (CHMc) with the geometrical aspect has been deemed to follow a linear regression model, as well as the growth of the deviatoric moment component with the geometrical aspect ratio, has been deemed to follow the sigmoidal, Morgan-Mercer-Flodin (MMF) nonlinear regression model.

Steel matrix composites (SMCs) reinforced with WC particles were fabricated via selective laser melting (SLM) by employing various laser scan strategies. A detailed relationship between the SLM strategies, defect formation, microstructural evolution, and mechanical properties of SMCs was established. The laser scan strategies can be manipulated to deliberately alter the thermal history of SMC during SLM processing. Particularly, the involved thermal cycling, which encompassed multiple layers, strongly affected the processing quality of SMCs. S-shaped scan sequence combined with interlayer offset and orthogonal stagger mode can effectively eliminate the metallurgical defects and retained austenite within the produced SMCs. However, due to large thermal stress, microcracks that were perpendicular to the building direction formed within the SMCs. By employing the checkerboard filling (CBF) hatching mode, the thermal stress arising during SLM can be significantly reduced, thus preventing the evolution of interlayer microcracks. The compressive properties of fabricated SMCs can be tailored at a high compressive strength (∼3031.5 MPa) and fracture strain (∼24.8%) by adopting the CBF hatching mode combined with the optimized scan sequence and stagger mode. This study demonstrates great feasibility in tuning the mechanical properties of SLM-fabricated SMCs without varying the set energy input, e.g., laser power and scanning speed.

The present experimental investigation explores the ability of the corrugated actuator-tabs (or simply, the corrugated actuators) of aspect ratio 2 in encouraging the mixing of Mach 1.73 circular jet at different levels of expansion conditions. Essentially, rectangular, triangular, and semi-circular corrugated actuators are deployed at the opposite positions across the diameter of the nozzle outlet and compared with the plain or simple actuators located at the same positions. Quantitative and qualitative observations were conducted by pitot pressure measurements and shadowgraph flow visualization. Interestingly, the characteristic decays are higher for the semi-circular and triangular corrugated actuators, exhibiting superior mixing than the rectangular corrugated actuator in the far-field. However, the core length reduction for rectangular corrugation is greater than for triangular and semicircular corrugation geometry. As high as 96.5 % core length reduction was obtained for the rectangular corrugated actuators operating at the overexpansion condition. The pressure profiles along and perpendicular to these actuators confirmed that the deployment of the corrugation geometry significantly reduces the flow asymmetry. The shadowgraphic flow visualizations reveal that the plain and corrugated actuators weaken the waves and shorten the cells when compared to the uncontrolled or free jet.

A numerical study of stress distribution and fatigue behavior in terms of the effect of voids adjacent to inclusions was conducted with finite element modeling simulations under different assumptions. Fatigue mechanisms were also analyzed accordingly. The results showed that the effects of inclusions on fatigue life will distinctly decrease if the mechanical properties are close to those of the steel matrix. For the inclusions, which are tightly bonded with the steel matrix, when the Young’s modulus is larger than that of the steel matrix, the stress will concentrate inside the inclusion; otherwise, the stress will concentrate in the steel matrix. If voids exist on the interface between inclusions and the steel matrix, their effects on the fatigue process differ with their positions relative to the inclusions. The void on one side of an inclusion perpendicular to the fatigue loading direction will aggravate the effect of inclusions on fatigue behavior and lead to a sharp stress concentration. The void on the top of inclusion along the fatigue loading direction will accelerate the debonding between the inclusion and steel matrix.

It is well known that the laser-induced dynamics of a system is determined by three laser parameters, namely, wavelength, pulse width, and intensity. In this study, the laser polarization is presented as a new parameter that determines the dynamics of highly anisotropic materials. By performing first-principles electron-ion dynamics simulations assuming a laser wavelength of 800 nm, a full width at half-maximum of 10 fs, and a field intensity of 4 V/A, carbon nanotubes (CNTs) were found to be fragile or robust when the polarization was parallel or perpendicular, respectively, to the tube axis. This behavior was observed for both zigzag and armchair CNTs and is thus expected to be only weakly dependent on CNT chirality. The obtained results are anticipated to encourage experimental efforts to select CNTs of a particular orientation using pulsed lasers with controlled polarization.

To understand the evolution of stress-induced elastic wave anisotropy, three triaxial experiments were performed on sandstone specimens with bedding orientations parallel, perpendicular, and oblique to the maximum principal stress. P-wave velocities along 64 different directions on each specimen were monitored frequently to understand the anisotropy change at various stress levels by fitting Thomsen's anisotropy equation. The results show that the elastic wave anisotropy is very sensitive to mechanical loading. Under hydrostatic loading, the magnitude of anisotropy is reduced in all three specimens. However, under deviatoric stress loading, the evolution of anisotropic characteristics (magnitude and orientation of the symmetry axis) is bedding orientation dependent. Anisotropy reversal occurs in specimens with bedding normal/oblique to the maximum principal stress. P-wave anisotropy e ′ is linearly related to volumetric strain Sv and dilatancy, indicating that stress-induced redistribution of microcracks has a significant effect on P-wave velocity anisotropy. The closure of initial cracks and pores aligned in the bedding direction contributes to the decrease of the anisotropy. However, opening of new cracks, aligned in the maximum principal direction, accounts for the increase of the anisotropy. The experimental results provide some insights into the microstructural behavior under loading and provide an experimental basis for seismic data interpretation and parameter selection in engineering applications.

High-speed penetration into carbon fiber composites is of fundamental importance to materials science and impact engineering, but research along this line suffers considerably from the lack of direct experimental observations. Here we investigate such penetration dynamics of a unidirectional carbon fiber reinforced epoxy (UCFRE) composite, with a combination of in situ, ultrafast, synchrotron phase contrast imaging and finite element (FE) analysis. The experiments yield the first direct observation on projectile trajectories and fiber-scale deformation and damage in the UCFRE composites during supersonic microprojectile penetration, for different fiber orientations ( 0 ∘ − 90 ∘ from the impact direction) and projectile velocities 600 − 850 m.s - 1 , at unprecedented temporal ( ∼ 100 ps) and spatial (5 μm) resolutions. The maximum penetration depth decreases with increasing fiber orientation angles, as a result of anisotropic damage evolution in the composite sample. Strain localizations are prone to develop along a direction perpendicular to the fiber orientation, while the damage or cavity region, along the fiber direction. FE modeling with a three-dimensional Hashin criterion yields consistent projectile trajectory and cavity morphology with the experimental results. With increasing fiber orientation angles, damage analyses show a transition in the damage mode from fiber compression to matrix compression damage, in line with the increasing maximum penetration depth.

A sputtered tape that uses a CoPt-based granular recording layer was developed for practical application in the next generation of large-capacity magnetic tapes. 1) First, disk media were prepared by depositing films onto glass substrates using an inline disk sputter machine in which the substrates were stationary facing the target, and the ability to control the crystalline orientation, the magnetic isolation, and the magnetic anisotropy of the recording layer, which are the important functions of the underlayer, was investigated. As a result, it was found that the medium with Co60Cr40 (45 nm)/Co60Cr40-15 vol.% TiO2 (5 nm) as the underlayer has the same properties as the medium with the Ru underlayer. 2) Next, a sputtered magnetic tape with Co60Cr40 (25 nm)/Co60Cr40-SiO2 (25 nm) as the underlayer deposited on a polymer film was prepared using a roll-to-roll sputtering machine. The ability to control the crystalline orientation and magnetic isolation of the magnetic recording layer was evaluated, and from the results it was found that a magnetic film with a granular structure was formed on the sputtered magnetic tape in which the $c$ -axis of the magnetic crystal grains is oriented in the direction perpendicular to the film and the magnetic crystal grains are separated by the SiO2 amorphous phase. 3) Furthermore, when the recording properties of the sputtered magnetic tape with a Co60Cr40 (25 nm)/Co60Cr40-SiO2 (25 nm) underlayer were compared with those of a magnetic tape for a linear tape-open (LTO) format eighth-generation tape cartridge (LTO 8), it was confirmed that the broadband signal-to-noise ratio of the sputtered tape with a Co60Cr40/Co60Cr40-SiO2 underlayer is 4.2 dB higher than that of the LTO 8 tape at a linear density of 300 kfci.

We demonstrate via micromagnetic simulations that a magnetic domain, which has two straight domain walls (DWs) and is formed in a perpendicularly magnetized ferromagnetic metal (FM), moves through a perpendicularly magnetized ferromagnetic insulator (FI) because of the spin-transfer torque arising from a spin-polarized current flowing in the FM. This phenomenon could be used for realizing racetrack memory with a continuous loop structure built from a nanowire comprising an FM/FI junction. We employ two nanowire structures in which two FMs are separated by a rectangular or a zigzag FI. In the system with a rectangular FI, the domain passes through the insulator when the length of the insulator is shorter than the DW length. However, the domain transforms into an unstable structure with current-induced domain motion after it passes through the insulator. In the system with a zigzag FI, the domain passes through the insulator irrespective of the length of the insulator. When passing through the zigzag FI, the velocity of the domain increases.

In this study, we report the design and simulation of an electrostatic ion lens system consisting of 22 round metal plates. The opening of the extractor plate is covered with metal mesh, which is for shielding the interaction region of the lens system from the high DC voltages applied to all other plates than the repeller and extractor plates. The Simion simulation shows that both velocity-mapping and time focusing can be achieved simultaneously when appropriate voltages are applied to each of the plates. This makes the ion lens system be able to focus large ionic volumes in all three dimensions, which is an essential requirement for crossed ion-molecule scattering studies. A three-dimensional ion velocity measurement system with multi-hit and potential multi-mass capability is built, which consists of a microchannel plate (MCP), a P47 phosphor screen, a CMOS camera, a fast photomultiplier tube (PMT), and a high-speed digitizer. The two velocity components perpendicular to the flight axis are measured by the CMOS camera, and the time-of-flight, from which the velocity component along the flight axis can be deduced, is measured by the PMT. A Labview program is written to combine the two measurements for building the full three-dimensional ion velocity in real time on a frame-by-frame basis. The multi-hit capability comes from the fact that multiple ions from the camera and PMT in the same frame can be correlated with each other based on their various intensities. We demonstrate this by using the photodissociation of CH3I at 304 nm.

A kutatómunka az S960QL nemesített és az S960M termomechanikusan kezelt nagyszilárdságú szerkezeti acélok elektronsugaras hegesztett kötéseinek fáradásos repedésterjedéssel szembeni ellenállására irányult. A hegesztési kísérletek során 15 mm vastag alapanyagokat alkalmaztunk hozaganyag nélküli (autogén), I-varratos, hegesztett kötések létrehozásához. A repedésterjedési vizsgálatokhoz alkalmazott hárompontos hajlító (TPB) próbatesteket úgy munkáltuk ki, hogy azok a jellemző irányokra merőlegesek, illetve párhuzamosak legyenek, valamint a bemetszések helyzetét a hegesztett kötések jellemző részeinek (varrat, beolvadási vonal, hőhatásövezet) elemzése céljából is változtattuk. Ennek megfelelően a vizsgálataink során terjedő repedések a valós szerkezetekben előforduló, különböző repedés megjelenési helyeknek felelnek meg. A vizsgált S960M acél elektronsugaras hegesztett kötésének fáradásos repedésterjedéssel szembeni ellenállása a vizsgált irányokban szignifikánsan különbözőnek bizonyult, az S960QL acél esetében ilyen különbség nem mutatkozott. A vizsgált S960QL acél elektronsugaras hegesztett kötései, mindkét vizsgált irányban lényegesen érzékenyebbeknek bizonyultak a fáradással terjedő repedések elhelyezkedésére, mint a vizsgált S960M acél kötései.

Twisted trilayer graphene (TLG) may be the simplest realistic system so far, which has flat bands with nontrivial topology. Here, we give a detailed calculation about its band structures and the band topology, i.e. valley Chern number of the nearly flat bands, with the continuum model. With realistic parameters, the magic angle of twisted TLG is about 1.12$^{\circ}$, at which two nearly flat bands appears. Unlike the twisted bilayer graphene, a small twist angle can induce a tiny gap at all the Dirac points, which can be enlarged further by a perpendicular electric field. The valley Chern numbers of the two nearly flat bands in the twisted TLG depends on the twist angle $\theta$ and the perpendicular electric field $E_\perp$. Considering its topological flat bands, the twisted TLG should be an ideal experimental platform to study the strongly correlated physics in topologically nontrivial flat band systems. And, due to its reduced symmetry, the correlated states in twisted TLG should be quite different from that in twisted bilayer graphene and twisted double bilayer graphene., Comment: 5 pages, 3 figures

This study investigated the applicability of detecting pitting corrosions on stainless steel weld overlay cladding using uniform eddy current testing, which is insensitive to surface undulation, and rotating eddy current testing (RECT), which can be considered a superposition of uniform eddy current testing in orthogonal directions. The performance of the two techniques in detecting artificial pitting corrosions on and next to weld beads was compared. The signal distributions revealed that only RECT was capable of describing the surface profiles of pitting corrosions. The results of uniform eddy current testing could not distinguish between pitting corrosions and cracks. The probability of detection curves drawn to quantitatively indicate the detection capabilities of the two techniques revealed that uniform eddy current testing with induced eddy currents parallel and perpendicular to weld beads was better than RECT in detecting pitting corrosions on and next to weld beads, respectively. Scanning twice by uniform eddy current testing at orthogonal orientations may be a better process for detecting pitting corrosion on weld overlay cladding compared with using RECT. The measured signals of the two techniques in normal direction were located around the edges of the pitting corrosions, which only indicated the depth around edges. The results suggested that uniform eddy current testing and RECT with normal direction magnetic field signals may be inadequate for evaluating the maximum depth of pitting corrosions or large corrosions.

The 7-hole probe measurement system is mainly used to measure three-dimensional flow fields. During the measurement, the probe head was in direct contact with the measured object, and the head structure had a significant influence on the accuracy of the flow field measurement. The main influencing factors were the hole opening mode, hole position, and hole diameter. For a hemispherical 7-hole probe with perpendicular and forward-facing holes, orthogonal experiments with three levels and three factors (inflow velocity, hole position, and hole diameter) were designed, and additional experiments were conducted on the significant factors. The importance of factors was evaluated based on the correlation between different structural parameters and the pressure coefficient. The experiment was simulated using FLUENT, and the numerical simulation results demonstrated that the square of deviance at the inlet velocity, hole diameter, and hole position was 0.0018, 0.0013, and 0.3611, respectively. The position of the hole has a significant influence on the measurement results, but the influence of the inflow velocity and hole diameter is negligible, and the pressure coefficient is the smallest when the hole is at 45°. For the hemispherical 7-hole probe with forward facing hole, the hole is the best at approximately 45°, and considering the convenience of processing, the diameter of the hole can be selected as the diameter of the 1/10 probe.

Aiming at object grasping of indoor mobile robots, this paper develops an object localization system based on the fusion of a monocular camera and a two-axis-controlled laser ranging sensor. The system can locate the specified object in space without obtaining the background depth information of the object, which reduces the consumption of computational resources and has a low cost. According to the coordinate mapping of the object in the image, the measurement point of the laser ranging sensor is controlled to coincide with the target point by two servo motors in perpendicular axes. Thus, the spatial location of the target point can be determined from the rotation angles of the cradle head motors and the laser-measured distance together. To accurately control the rotation angles, a compound strategy combining feedback and feedforward is proposed. On the one hand, the feedback of the laser measurement point is introduced in the image coordinate to realize the close-loop control of the measurement point. On the other hand, a feedforward compensator based on disturbance observation is designed to reduce the influence of robot motion. An experimental setup is developed and substantial experiments are implemented to evaluate the performance of the proposed system. The results show that object localization can be effectively achieved with good accuracy and dynamic response.

A model of a superlattice consisting of alternating single and double layers of graphene is studied. The energy spectrum of the superlattice can be controlled by an external electric field perpendicular to a sample’s surface. It is shown that the energy spectrum of such a structure can be approximated by the Kane model. The coefficient of interband absorption for such a superlattice is calculated.

The transverse vibrations of drill bits held in a chuck and plucked were studied using a laser Doppler interferometer (LDV). We found that free vibrations are generally dominated by a beat originating from the superposition of two components with similar frequencies (within a few percent), which belong to the transverse vibrations of the drill bits in the direction of the groove end and perpendicular to that. The tuning fork model gives the frequencies of the free vibrations of the 9mm diameter drill bit with an accuracy of a few percent, while in the case of thicker (10 and 12mm) drill bits it overestimates by 15-20 percent. We also examined the effect of supporting the drill bit, pulling the drill bit further out of the chuck, and the type of tapping (blunt or sharp) on the vibration spectrum.

The high sensitivity for low-frequency fields makes the tiny giant magnetoresistance (GMR) sensors suitable for high-resolution eddy-current (EC) imaging. In this work, we proposed a novel design of the miniature differential EC probe with a spin-valve GMR sensor for surface and subsurface EC imaging. The differential EC probe consists of a full-bridge GMR chip mounted vertically on the edge of a tiny printed circuit board to reduce the liftoff distance. The excitation signal is perpendicular to the sensing axis of the GMR chip, which makes it sensitive to the unbalance EC signal on the surface of a conductive sample. The miniature EC probe operated at frequencies from 5 to 65 kHz is sensitive to the hidden defects on a flat conductor. The spatial resolution and stability of the device are verified by taking the 2-D scan images over the copper film samples with hidden defects, showing that the spatial resolution is better than 2 mm for the flaw 0.5 mm below the top surface of a multilayer structure. The proposed device is useful in the detection of small surface and subsurface defects, such as cracks, metal loss, and other mechanical damages.

In any sensory system, the Electromagnetic (EM) shielding of the channel-carrying signal is a fundamental technique to provide a noise-immune measurement system. Severe failures and uncertainty may occur if the external EM fields interfered with the measurements. Typically, the shielding is realized by enclosing the channel-carrying signal with thinconductive hollow structures. However, with such structures, it is required to provide access to the interior components from the outside, for wires' connections, or better heat dissipation. This can be considered as a weakness in such the external magnetic fields can penetrate through the shielding structure. In this paper, the EM shielding effectiveness is considered for long hollow-cylinder structures with slots. The induced eddy current in thin-conductive shielding systems with slots together with the magnetic fields at different conditions are modeled. The objective is to determine the impact of the integrated slots along with the structure. The influence of the slots' sizes (α) and position relative to the excitation magnetic field (i.e., the declination angle (β)) are investigated to evaluate the shielding effectiveness by means of the determination of the shielding factor. The results reveal the inherent relationship between the shield parameters and shielding effectiveness. The shielding effectiveness deteriorates by the slots' integration within the shielding surface. However, decreasing the size of the slots improves the shielding, significantly, towards the shielding effectiveness of the continuous cylindrical structure. Additionally, utilizing the symmetry in the structure positioning the slots in the direction perpendicular to the magnetic field flux improves the shielding effectiveness, drastically. Such a model can be considered to evaluate the degree of effectiveness or success of integrating opening slots within the shielding structure, which can be applied to different types of instrumentation systems specifically at the sensor-electronics interface.

There is great interest in exploiting van der Waals gaps in layered materials as nanofluidic channels. Graphene oxide (GO) nanosheets are known to spontaneously assemble into stacked planar membranes with transport properties that are highly selective to molecular structure. Use of conventional GO membranes in liquid-phase applications is often limited by low flux values, due to intersheet nanochannel alignment perpendicular to the desired Z-directional transport, which leads to circuitous fluid pathways that are orders of magnitude longer than the membrane thickness. Here we demonstrate an approach that uses compressive instability in Zr-doped GO thin films to create wrinkle patterns that rotate nanosheets to high angles. Capturing this structure in polymer matrices and thin sectioning produce fully dense membranes with arrays of near-vertically aligned nanochannels. These robust nanofluidic devices offer pronounced reduction in fluid path-length, while retaining the high selectivity for water over non-polar molecules characteristic of GO interlayer nanochannels., Vertically stacked graphene oxide sheets are promising structures for molecular sieving technologies. By folding large planar sheets in an accordion-like manner, Liu et al. fabricate a thin robust filter with near-vertically aligned nanochannels geared towards commercial separation membranes.