Edge Of Film Research Articles

Mitigation of the Moiré Effect in Overlapped Optical Films by Lateral Buckling of Sharp Edges of Prism Arrays

AbstractThe moiré effect arises from the superposition of periodic structures with differences in periods or angles. Although the moiré effect can be exploited as an intriguing tool to fabricate complex metastructures, reduction of the moiré effect can be an important issue in display technology that uses many optical films with periodic patterns. Because of the superposition, dark and bright regions can be seen by the naked eye, which is a reason for the degradation of the visual quality. In this work, the lateral deformation of shape edges of prism films is harnessed to reduce the moiré effect. After the preparation of a microprism array with hydrogel materials, the hydrogel microprism array is swelled via penetration of water molecules into the hydrogel networks. Due to the compressive stress applied by volume expansion with confinement, only the sharp edges laterally buckle randomly. The swollen hydrogel prism array is replicated by photopolymerization, and prism arrays with laterally buckled edges are obtained. The randomized edges help reduce the moiré effect of the optical film when the prism array is overlapped with other periodic devices, such as other prism arrays or display devices consisting of microscale pixels, without a significant decrease in the optical performance.

Interfacial delamination for an orthotropic thin film/substrate system

In this study, the interface behavior of an orthotropic thin film bonded imperfectly to an orthotropic substrate is considered. The analytical method employs the integro-differential formulation with the aid of membrane assumption. The loading scenarios include either a constant temperature rise applied to the film or a uniform compressive stress applied to the film edges. The sensitivity of the film stresses as well as the shear stress singularity factor to the different material combination are extracted. The results indicate that the shear stress singularity factor dramatically increases as the delamination length exceeds 50% of the film length. The results of this study would be useful for the design engineers focused in flexible and stretchable electronic devices

De-wetting of evaporating drops on regular patterns of triangular posts.

Directional wicking and spreading of liquids can be achieved by regular micro-patterns of specifically designed topographic features that break the reflection symmetry of the underlying pattern. The present study aims to understand the formation and stability of wetting films during the evaporation of volatile liquid drops on surfaces with a micro-pattern of triangular posts arranged in a rectangular lattice. Depending on the density and aspect ratio of the posts, we observe either spherical-cap shaped drops with a mobile three-phase contact line or the formation of circular or angular drops with a pinned three-phase contact line. Drops of the latter class eventually evolve into a liquid film extending to the initial footprint of the drop and a shrinking cap-shaped drop sitting on the film. The drop evolution is controlled by the density and aspect ratio of the posts, while no influence of the orientation of the triangular posts on the contact line mobility becomes evident. Our experiments corroborate previous results of systematic numerical energy minimization, predicting that conditions for a spontaneous retraction of a wicking liquid film depend weakly on the orientation of the film edge relative to the micro-pattern.

Trapped Multimodal Resonance in Magnetic Field Enhancement and Sensitive THz Plasmon Sensor for Toxic Materials Accusation

THz Plasmonic metasurfaces (TPMs) sensor have emerged as a benchmark principle for harnessing and manipulating light at the nano-scale and enabling to use in optical functionalities for detection of different analytes in liquid and solid phases. Plasmonic sensors with very high sensitivity and precision are particularly important to the fields of chemical and biological materials like ammonia and urea quality monitoring. In this paper, we present a four-band plasmonic metasurface structure with very high sensitivity ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SS</i> ), figure of merit ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">FoM</i> ), and magnetic field intensity enhancement (MFIE). Max MFIE in four-band of the proposed plasmonic metasurface sensor have been generated by strong coupling between input waves and surface plasmon polaritons (SPPs) that show very narrow bands, and harness the light in near-infrared regime. The narrow absorption spectra leads the gigantic MFIE in four bands that generated due to the excitation of the SPPs in the edge of the metal thin film and support the Transverse Magnetic (TM) surface mode. The optical responses of the presented plasmonic metasurface sensor have be shown the best characteristics/operation Max sensitivity, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">FoM</i> and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">MFIE</i> that obtained as 1300 nm/RIU, 79 and 6.3×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">8</sup> , respectively. Results show that the sensor has several high and outstanding performances in comparison with other sensors in the last decade. Also, the presented sensor is valuable and satisfactory in the case of a tunable and compact footprint device. Accordingly, the findings have revealed that the interested four-band plasmonic metasurface is practical work in different sensor applications such as bio-chemical and refractive index sensing.

On the mechanics of a double thin film on a finite thickness substrate

The single edge loading problem of a double thin film deposited on a finite thickness substrate is considered. The films and the substrate are assumed to be homogeneous and isotropic. The membrane analogy is adopted for the films and two dimensional elasticity is applied to the substrate. The compatibility of the tangential strain between the film and the substrate yields the governing singular integral equation in terms of the interfacial shear stress. The numerical solution is provided using the Gauss–Chebyshev discretization method. The sensitivity of the interfacial shear and the normal stresses to several effective parameters are examined. The results of current study are compatible with the finite element simulations. The lowest interfacial shear stress pertains to a substrate with a free edge boundary condition. The results of current study are applicable to the debonding failure assessment of the multi-layer joints and semiconductors which are susceptible to the interfacial shear stresses near the film edges.

The effect of cavities produced by focused ion beam milling on solid state dewetting of thin Au films

The goal of this study was to explore the possibility to control the nucleation and expansion of holes during initial stages of solid state dewetting of thin polycrystalline Au film deposited on sapphire substrate. To this end, we fabricated isolated triangular cavities in the film employing Ga+ ion milling in the focused ion beam instrument. The following dewetting heat treatments indicated that the cavities do promote early nucleation and expansion of dewetting holes, yet these holes develop tortuous shapes dominated by a random distribution of nearby hillocks in the film. Deep holes exhibited a triangular patch of amorphous Al-Ga-O phase at their bottom which retained its size and morphology during subsequent thermal treatments. This amorphous phase caused some delay in holes expansion at high temperatures. We proposed a geometrical model of the retracting metal film edge pinning by the amorphous phase. The observed pinning phenomenon can be utilized for the design of patterned thin films with increased thermal stability.

悬挂式旋耕起垄覆膜一体机的设计与试验

Considering the planting mode and agronomics requirements of the existing facilities, the high-power rototilling ridge hoisting and lamination machine is difficult to operate in the greenhouse of the facility, and the small hanging rotary ridge raiser has technical problems such as insufficient horsepower. This paper designs the hanging rotary tillage ridging and film - covering machine. The machine realizes a single operation process to complete rotary tillage, ridging, drip irrigation, film laying and film edge covering soil suppression and other mechanized compound operations. The innovatively designed adjustable ridging device of this machine can steplessly adjust the size of the ridge. The ridge height after operation of the machine is 25-35 cm, the ridge width is 70-80 cm, the ridge shape is arc-shaped, the size is adjustable, and the operation efficiency is improved being 0.17-0.23 hectares/hour, the machine driving speed is set at low speed 1 gear. The machine has high operating efficiency, the arc-shaped ridge body is uniform and compact. the ridge body has a large lighting surface, the film is tightly laid, and it is close to the ridge surface without wrinkling. By test data analysis, the tillage depth stability is 93%, the ridge height qualified rate is 100%, the ridge width qualified rate is 85%, the ridge spacing qualified rate is 95%, the film edge covered soil thickness is 40 mm, the working efficiency is 0.802 hm2/h, the fuel consumption per hectare is 9.02 kg·h/m2, and the three shifts work without fault. To sum up, it meets the agronomic requirements of ridging and film planting.

Semi-empirical model for the liquid fuel film formed by an oblique jet impinging on a curved wall

The operating conditions and the properties of the liquid have great effects on the shape and size of the liquid film and eventually affect the efficiencies of the atomization of alternative fuels, liquid jet impingement cooling, and equipment cleaning processes. The shape and size of the liquid film are dominated by the distance from the stagnation point to the liquid film edge(rmax). In this study, after deducing the thickness profile and the theoretical rather than the numerical solution of the initial velocity profile of the liquid film, a set of semi-empirical models about the shape, size of the liquid film, and the width of the raised zone formed by an oblique jet impinging on curved walls have been developed. In order to validate the theoretical model, a corresponding experiment has been developed, in which the jet velocities, impingement angles, liquid viscosity, surface tension, and radius of curvature have been included. The comparisons showed the theoretical results are in good agreement with the experimental data. The error for the location of the inner and outer border lines are less than 14.9% and 13.5%, respectively, except for the location in the upstream part of the film. And the effects of jet velocity, impingement angle, surface tension, dynamic viscosity, and radius of curvature were also theoretically discussed. The outer border line of the liquid film is dominated by the impingement angle and the impingement velocity, which affect the rmax exponentially and linearly, respectively. And the liquid viscosity and surface tension coefficient also affect the rmax approximately linearly. But the effects of the liquid viscosity and surface tension coefficient on the rmax are much less than the impingement velocity. The radius of curvature has little effect on the outer border lines and width of the raised zone when gravity is ignored.

Gyromotion of skyrmion along the nanofilm edge driven by spin waves

The dynamic behaviors of skyrmion in a nanofilm driven by spin waves have been numerically investigated by means of micromagnetic simulation. The results show that (i) the skyrmion shows a backward motion (towards the spin wave source) in the nanofilm with skyrmion Hall effect due to the spin wave scattering from the skyrmion; (ii) a fast (>100m/s) and periodic skyrmion motion can be achieved by introducing two spin wave sources to force the skyrmion move along the film edges; (iii) the velocity of the skyrmion motion depends on the amplitude and frequency of the driving magnetic fields as well as the nanofilm geometry, and the rotation sense of the skyrmion motion along the film edge depends on the topological number (Q=±1). The results might be a guidance for the design and development of future skyrmion-based devices in which skyrmions are used as information carriers.

Helicity-dependent photoconductance of the edge states in the topological insulator Bi2Te3

The helicity-dependent photoconductance of the edge states in three-dimensional topological insulator Bi2Te3 films is investigated. It is revealed that the helicity-dependent photoconductivity current on the left edge of the Bi2Te3 film shows an opposite sign with that on the right edge. In addition, the helicity-dependent photoconductivity current increases linearly with the applied longitudinal electric field, and it reverses the sign with the reversal of the electric field. As the thickness of the Bi2Te3 film increases, the helicity-dependent photoconductivity current also increases. Theoretical analysis suggests that the helicity-dependent photo-conductivity current may come from the intrinsic spin orbit coupling (SOC) or the SOC introduced by the chiral impurities or defects.

ASA-DRNet: An Improved Deeplabv3+ Framework for SAR Image Segmentation

Pollution caused by oil spills does irreversible harm to marine biosystems. To find maritime oil spills, Synthetic Aperture Radar (SAR) has emerged as a crucial mean. How to accurately distinguish oil spill areas from other types of areas is a committed step in detecting oil spills. Owing to its capacity to extract multiscale features and its distinctive decoder, the Deeplabv3+ framework has been developed into an excellent deep learning model in field of picture segmentation. However, in some SAR pictures, there is a lack of clarity in the segmentation of oil film edges and incorrect segmentation of small areas. In order to solve these problems, an improved network, named ASA-DRNet, has been proposed. Firstly, a new structure which combines an axial self-attention module with ResNet-18 is proposed as the backbone of DeepLabv3+ encoder. Secondly, a atrous spatial pyramid pooling (ASPP) module is optimized to improve the network’s capacity of extracting multiscale features and to increase the speed of model calculation and finally merging low-level features of different resolutions to enhance the competence of network to extract edge information. The experiments show that ASA-DRNet obtains the better results compared to other neural network models.

Air-stable mixed cation lead halide perovskite films and microscopic study of their degradation process.

We report the preparation and nanoscale photophysical characterization of mixed cation perovskite films of the composition MA1-xFAxPbI3, with x = 0, 0.3 and 0.5. Films with x = 0.5 and 0.3 prepared in air using ethyl acetate as an antisolvent in a one-step spin-coating process are compositionally stable in ambient air for more than a year, in contrast to films prepared using a chlorobenzene antisolvent. The onset of degradation of the films near the film edges was monitored using in situ photoluminescence (PL) spectroscopy. The PL spectra of the degradation products are consistent with the PL spectra of 2D perovskite sheets of varying thicknesses. Morphologically, aging of the films brings about coalescing of the film grain structure into larger crystal grains. Furthermore, monitoring of the time traces of PL from individual nanoscale locations in the films (PL blinking) reveals that aging of the films does not change the extent of dynamic PL quenching or affect the observed long-range charge diffusion on the order of micrometers.

Development of Automated Delivery Quality Assurance Analysis Software for Helical Tomotherapy.

To develop a fully automated in-house gamma analysis software for the "Cheese" phantom-based delivery quality assurance (QA) of helical tomotherapy plans. The developed in-house software was designed to automate several procedures, which need to be manually performed using commercial software packages. The region of interest for the analysis was automatically selected by cropping out film edges and thresholding dose values (>10% of the maximum dose). The film-measured dose was automatically aligned to the computed dose using an image registration algorithm. An optimal film scaling factor was determined to maximize the percentage of pixels passing gamma (gamma passing rate) between the measured and computed doses (3%/3 mm criteria). This gamma analysis was repeated by introducing setup uncertainties in the anterior-posterior direction. For 73 tomotherapy plans, the gamma analysis results using the developed software were compared to those analyzed by medical physicists using a commercial software package. The developed software successfully automated the gamma analysis for the tomotherapy delivery quality assurance. The gamma passing rate (GPR) calculated by the developed software was higher than that by the clinically used software by 3.0%, on average. While, for 1 of the 73 plans, the GPR by the manual gamma analysis was higher than 90% (pass/fail criteria), the gamma analysis using the developed software resulted in fail (GPR < 90%). The use of automated and standardized gamma analysis software can improve both the clinical efficiency and veracity of the analysis results. Furthermore, the gamma analyses with various film scaling factors and setup uncertainties will provide clinically useful information for further investigations.

Inverse metal-assisted chemical etching of germanium with gold and hydrogen peroxide

Metal-assisted chemical etching (MACE) is a flexible technique for texturing the surface of semiconductors. In this work, we study the spatial variation of the etch profile, the effect of angular orientation relative to the crystallographic planes, and the effect of doping type. We employ gold in direct contact with germanium as the metal catalyst, and dilute hydrogen peroxide solution as the chemical etchant. With this catalyst-etchant combination, we observe inverse-MACE, where the area directly under gold is not etched, but the neighboring, exposed germanium experiences enhanced etching. This enhancement in etching decays exponentially with the lateral distance from the gold structure. An empirical formula for the gold-enhanced etching depth as a function of lateral distance from the edge of the gold film is extracted from the experimentally measured etch profiles. The lateral range of enhanced etching is approximately 10–20 μm and is independent of etchant concentration. At length scales beyond a few microns, the etching enhancement is independent of the orientation with respect to the germanium crystallographic planes. The etch rate as a function of etchant concentration follows a power law with exponent smaller than 1. The observed etch rates and profiles are independent of whether the germanium substrate is n-type, p-type, or nearly intrinsic.

Contactless Discharge-Driven Method for Separation of Oil-Water Mixtures.

Oil–water separation technology has potential applications in wastewater treatment, petroleum refining and edible oil processing. As the ultimate means in oil-water treatment, electrostatic coalescence technology has been widely used in oil fields and refineries. However, the technology has many problems, such as complex processes, electrode corrosion, and the inability to treat high-water-cut crude oil emulsions. Here, we propose a contactless method of oil-water separation by corona discharge. With corona discharge of a needle–plate electrode configuration, the oil droplet diffuses to the ITO glass surface and the water droplet oscillates at the edge of the PET film. Here, such droplet behaviors are described in detail. Based on the motion behavior of the oil and water droplet, we designed an efficient oil-water separation device. After the oil-water mixture passes through the device, the oil content in the oil region can reach 99.25% with a voltage of 8 kV. In addition, the separation speed of the oil-water mixture can also be adjusted by varying the corona discharge voltage. This paper presents a simple and innovative method for oil-water separation.

Comparison between radiochromic film and Sun nuclear edge diode detector during the commissioning of small field size radiosurgery cones

Stereotactic Radiosurgery (SRS) is a procedure that uses ionizing radiation in a single fraction or few fractions to treat intracranial lesions. Usually, for these treatments, small photon fields, formed by circular collimators or micro multileaf collimators are used. The objective of the present work is to compare the measurements of the dose in depth (PDD), the off-axis ratio (OAR), and the output factor (OF) using Edge diode and radiochromic films and analyzing the agreement between the two detectors during these measures. In the gamma index analysis of the profiles, the minimum percentage reached was 98.3% of the points in the criterion 1% and 0.5 mm. The maximum percentage difference in the output factor was 2.79% for a cone 4 mm and 10FFF. In the gamma index analysis of the PDDs, the minimum percentage reached was 97% of the points in the criterion 1% and 1mm. The results show a good agreement between the edge detector and the film in small field measurements for radiosurgery.

Giant circulating malignant cells spotted in feathered edge of blood film.

A 20-year-old male presented with a 4-week history of dry cough, night sweats, weight loss, and fever. Blood tests showed normocytic anemia (hemoglobin 71 g/L) and severe thrombocytopenia (platelets 17 × 109/L). His blood film demonstrated leukoerythroblastosis, occasional red blood cell fragments, and giant cells in the feathered edge (Figure 1, panel A; Wright–Giemsa stain, original magnification ×400). Imaging revealed a large anterior mediastinal mass. Bone marrow biopsy revealed a hypercellular marrow with extensive involvement by high-grade malignant cells (Figure 1, panel B—aspirate; Wright–Giemsa stain, original magnification ×400; panel C—trephine biopsy; hematoxylin and eosin stain, original magnification ×200). Immunohistochemical staining only revealed CD43+, pankeratin+, and weak CD30 (Figure 1, panels D–F). The mediastinal mass was biopsied and showed similar results, as well as positivity for Sal-like protein 4 (SALL4; Figure 1, panel G) and epithelial membrane antigen (EMA). Serum alphafetoprotein was also elevated. Karyotype and metaphase Fluorescence In Situ Hybridization (FISH) from the bone marrow showed two isochromosome 12p (Figure 1, panels H–I). The final diagnosis was nonseminomatous germ cell tumor, not further classified. This case illustrates the importance of scanning the feathered edge of blood films to check for circulating metastatic cells. While often discussed in theory and seldom seen in practice, it is rare cases like this that reaffirm the importance of checking the feathered edge. We would like to thank Dr. Brian F. Skinnider, Anatomical Pathology at Vancouver General Hospital, for signing out the surgical report for the anterior mediastinal biopsy and arranging for the appropriate immunohistochemical stains. The authors declare no conflict of interest. Robert Guo and Tyler Smith helped sign out the hematopathology report on the bone marrow specimen for this case, as well as in writing and editing this manuscript.

High-Performance Cold Cathode X-ray Tubes Using a Carbon Nanotube Field Electron Emitter.

A cold cathode X-ray tube was fabricated using a carbon nanotube (CNT) field electron emitter made by a free-standing CNT film which is composed of a highly packed CNT network. A lot of CNT bundles with a sharp tip are vertically aligned at the edge of the thin CNT film with a length of 10 mm and a thickness of 7 μm. The cold cathode X-ray tube using the CNT field emitter presents an extremely high tube current density of 152 A/cm2 (corresponding to tube current of 106.4 mA), the electron beam transmittance of 95.2% and a small focal spot size (FSS) of 0.5 mm. In addition, the cold cathode X-ray tube also shows stable lifetime during 100 000 shots. High emission current density of the cold cathode X-ray tube is mainly attributed to a lot of electron emission sites at an edge of the CNT film. The small FSS is caused by an ensemble of the CNT field electron emitter made by a free-standing thin CNT film and the optimized curve-shape elliptical focusing lens. Based on obtained results, the cold cathode X-ray tube can be widely used for various X-ray applications such as medical diagnosis systems and security check systems in the future.

Characterization of inhomogeneity at edges of graphene oxide films using tip‐enhanced Raman spectroscopy

AbstractWe developed a reflection‐type tip‐enhanced Raman spectroscopy system with a high spatial resolution to be able to apply for many kinds of opaque samples and obtained Raman images and Raman spectra at the edges of graphene oxide (GO) films using this system. We found that the relative intensity of the D band to the G band (ID/IG) increased 0.6 to 1.5 at the edges of the GO plane and the C‐H stretching mode at approximately 2920 cm−1 was strongly observed at the edges. These results suggest that the graphite network structures are broken down at the edges of the GO plane, resulting in the high ID/IG ratio, and the dangling bonds are mainly terminated by C‐H, C‐O, O‐H, and/or COO‐ groups.

Tunable skyrmion–edge interaction in magnetic multilayers by interlayer exchange coupling

Magnetic skyrmions are appealing for applications in emerging topological spintronic devices. However, when magnetic skyrmions in a nanowire are driven by an in-plane current, a transverse Magnus force deflects their trajectories from the current direction, which tends to push the skyrmion toward the edge. If the current density is exceedingly large, the skyrmion will be annihilated around the edge, leading to a greatly reduced propagation distance and a maximum speed of the skyrmion, which is detrimental to skyrmion-based spintronic applications. Here, we prepare a magnetic multilayer Ta/[Pt/Co]3/Ru/[Co/Pt]3 and tailor the interlayer exchange coupling strength by varying the thickness of the Ru layer. Based on the magneto-optic Kerr effect microscope, we find that the skyrmion–edge interaction is tunable by the interlayer exchange coupling strength, namely, the strength of the repulsive potential from the film edge is tailored by the interlayer exchange coupling strength. Our results unveil the significant role of the interlayer exchange coupling in skyrmion dynamics.