Textured Layer Research Articles

One-step hydrothermal method to fabricate drag reduction superhydrophobic surface on aluminum foil

Superhydrophobic surface, covered by micro or nano textured layer, can trap and retain air pockets and possesses unique excellent properties. Here we propose a novel one-step hydrothermal method to fabricate superhydrophobic surface on aluminum foil. The film of sheet structure is Al[CF3(CF2)12COO]3, which can provide micro structures and reduce surface energy. The as-prepared surface with high contact angle and low sliding angle has some interesting characteristics. In the test, the powder dirt can be easily removed from the surface and the formation of ice is inhibited on it. The drag reduction ratio of the superhydrophobic surface is about 20–30% at the velocity of 2–5 m/s. We envision this superhydrophobic surface has a great prospect in industrial applications.

Multiscale adaptive regularisation Savitzky–Golay method for speckle noise reduction in ultrasound images

Speckle noise is one of the major artefacts in ultrasound images. The denoising faces the trade-off between noise suppression and structural preservation. In this study, multiscale adaptive regularisation Savitzky-Golay (MARSG) method, the new filter for removing speckle noise, is proposed. The proposed method combines the benefit of the multiscale analysis and the outstanding noise removing capability of Savitzky-Golay (SG) filter. The Laplacian pyramid is employed to separate an image into the noise, texture and object layers. Adaptive regularisation Savitzky-Golay (ARSG) filter is developed as the denoising filter in the noise and the texture layers. The denoising of the ARSG filter is adaptively adjusted in order to preserve the edges of objects in the image. The experiments on the synthetic and ultrasound images demonstrated that MARSG method offered better balance between noise removal and structural preservation than non-linear multiscale wavelet diffusion, feature-enhanced speckle reduction and regularised SG filter.

Assessment of the load capacity of the anchorage system connecting the textured layer with the structural wall of large slab buildings in the lights of experimental research and FEM analysis

The goal of the article is to compare the results obtained from experimental tests of a new type of anchoring, connecting the texture layer with the structural layer in external wall elements, used in large-panel construction with the results from FEM analysis. Two types of samples were subjected to experimental tests: single-layer uniform concrete and three-layer concrete with embedded point anchors and analogous samples with glued anchors. The test elements used C 12/15 and C 30/37 concrete, 12 mm diameter anchors, made of steel corresponding to the grade of stainless steel screws class 5.8, Sika Anchorfix-1 resin and XPS polystyrene. As for the three-layer samples, when testing, two forces were applied: tearing and shearing due to the detachment of the textured layer. The ANSYS program was used for numerical modelling of the analyzed samples. 3D models were built in which solid elements were used. For steel anchors, the material characteristics were taken as a two-line elasticplastic reinforcement. The Drucker-Prager model was used in the concrete elements, the linear-elastic model was adopted for the resin, and the brittle model according to the linear-elastic fracture mechanics for the polystyrene.

The effect of mechano-chemical treatment on structural properties of the drawn TiNi-based alloy wire

The rapid development of biomedical materials with the advanced functional characteristics is a challenging task because of the growing demands for better material properties in-clinically employed. Modern medical devices that can be implanted into humans have evolved steadily by replacing TiNi-based alloys for titanium and stainless steel. In this study, the effect of the mechano-chemical treatment on structural properties of the matrix and surface layer of the drawn TiNi-based alloy wire was assessed. A range of samples have been prepared using different drawing and etching procedures. It is clear from the results obtained that the fabricated samples show a composite structure comprising the complex matrix and textured oxycarbonitride spitted surface layer. The suggested method of surface treatment is a concept to increase the surface roughness for the enhanced bio-performance and better in vivo integration.

Analytical modelling of a three-layer wall system of strengthening for large-panel slab buildings by means of bonded anchors

The goal of the article is to elaboration analytical models describing a new system of reinforcing three-layer walls of large-panel buildings with bonded anchors. The use of this type of fasteners that bond the façade texture layer to the structural slab is necessary due to the low durability of previously used suspension elements. Various bonded anchorage systems were considered. The new anchorage systems were designed as two-anchors systems (horizontal anchor and diagonal anchors) and three-anchors systems (horizontal anchor and two diagonal anchors). The inclinations of these anchors are in the range of 30°-60° in relation to the surface of the element. For the above types of reinforcements, analytical models have been developed that take into account the change of strength parameters of the resin and steel from which the anchors were made, the interaction of materials resin-steel and resin-concrete and the effect of the simultaneous action of pull-out and shearing forces. Moreover, was assumed the simultaneous destruction of fasteners two- and three-anchors. The elaborated analytical models will be used to determine the load-bearing capacity of the new connector system, which will allow the elaboration of guidelines for strengthening three-layer walls of largepanel slab buildings.

The program piano cycle O. Gerasymenko "The Light of Awakened Dreams" from the standpoint of mastering polystylistic synthesis and sound terrain

Oksana Gerasymenko's Piano Cycle "The Light of Awakened Dreams" is considered as a promising educational material in classes on a specialized piano for the use of both individual plays and a cycle in general for the formation of a significant body of performing skills and techniques. It reflects the richness of stylistic tendencies and polytheisticism, inherent in its individual composer style. The cycle of O. Gerasymenko makes it possible to comprehend the richness of syntheses of genre features of the academic and pop-jazz spheres, the clarity of structures and free open forms, the clear separation of the functions of textural layers, and the constant change in sound density and relief, extended tone, modality and sinoric. The didactic tasks in the work include the metro-rhythmic, the positional difficulties, the problems of sound formation, the ratio of sound reliefs and background-sono-rous sounds, the aspects of pedaling, the achievement of the integrity of the melodic line, set out by interval duplications, timely poly-instrumental weights (flutes, harps, etc.), the feeling of drama of the deployment of the form without solving these accomplishments impossible to comprehend the artistic whole, defined by the author's program. Positive didactic qualities of the cycle are determined by the synthesis of concert and teaching activities, composer professionalism, consistent work on the repertoire of the ensembles and pedagogical needs.

Characterization of ultralow thermal conductivity in anisotropic pyrolytic carbon coating for thermal management applications

Pyrolytic carbon (PyC) is an important material used in many applications including thermal management of electronic devices and structural stability of ceramic composites. Accurate measurement of physical properties of structures containing textured PyC layers with few-micrometer thickness poses new challenges. Here a laser-based thermoreflectance technique is used to measure thermal conductivity in a 30-μm-thick textured PyC layer deposited using chemical vapor deposition on the surface of spherical zirconia particles. Raman spectroscopy is used to confirm the graphitic nature and characterize microstructure of the deposited layer. Room temperature radial and circumferential thermal conductivities are found to be 0.28 W m−1 K−1 and 11.5 W m−1 K−1, corresponding to cross-plane and in-plane conductivities of graphite. While the anisotropic ratio of the in-plane to cross-plane conductivities is smaller than previous results, the magnitude of the smallest conductivity is noticeably smaller than previously reported values for carbon materials and offers opportunities in thermal management applications. Very low in-plane and cross-plane thermal conductivities are attributed to strong grain boundary scattering, high defect concentration, and small inter-laminar porosity. Experimental results agree with the prediction of thermal transport model informed by the microstructure information revealed by Raman spectroscopy.

Experimental observation of hysteresis in a coherent metal-hydride phase transition

We investigate the hysteresis obtained in the hydrogen absorption and desorption cycle for a single crystal superlattice. Below the critical temperature, a small but clear hysteresis is observed in the pressure-composition isotherms, while it is absent above. The experimental results thereby prove the relevance of macroscopic energy barriers for obtaining hysteresis in coherent structural transformations. The textured Pd layer exhibits substantially larger hysteresis effects, which can be related to an irreversible energy loss caused by defect generation in Pd.

A study on the crystallization behavior of amorphous Ti50Ni25Cu25 shape memory ribbon by X-ray diffraction measurement

XRD spectra from the contact and free surfaces of amorphous Ti50Ni25Cu25 ribbon prepared by melt-spinning technique, crystallized, and aged at 500 °C for different times were collected for intensive investigation. A thin layer of textured grains with a thickness of 1 μm formed at the contact surface, having {100}B2 planes parallel to the ribbon surface during the crystallization process and resulting in an extraordinarily strong (200)B2 diffraction peak from the contact surface. This textured layer was caused by the pre-arrangement of atoms with their easy-growth <100>BCC direction parallel to the maximum temperature gradient perpendicular to the contact surface during the melt-spinning process. On the other hand, equiaxed and randomly orientated grains of about 300 ± 100 nm in size formed at the free surface. During the aging process, when aging time exceeded 15 min, precipitation of TiCu along {100}B2 planes significantly distorted the B2 lattice and thus led to broadening, which decreased the intensity of (200)B2 diffraction. Comparisons of experimental results with reported studies show that the texture developed in Ti50Ni25Cu25 ribbon is highly affected by the thickness and cooling rate.

Fabrication of nanostructured silicon surface using selective chemical etching

A two-stage process based on selective chemical etching induced by metal nanoclusters is used to fabricate nanostructured surfaces of silicon plates with a relatively low reflectance. At silicon surfaces covered with silver nanoclusters, the SERS effect is observed for rhodamine concentrations of about 10–12 M. At certain technological parameters, the depth of the nanostructured layer weakly depends on the conditions for the two-stage etching, in particular, etching time. Under otherwise equal conditions for etching, the rate of the formation of textured layer in the p-type silicon is two times greater than the formation rate in the n-type silicon.

About the control of semiconducting properties of chromia: investigation using photoelectrochemistry and orientation mapping in a TEM

The semiconducting properties of chromia, studied by photoelectrochemistry (PEC), are varied by oxidizing pure Cr as a function of temperature and oxygen activity. At 800 °C and a p(O2) of 10-14 atm, a single n-chromia is observed, while at 900 °C and a p(O2) of 10-12 atm a n- & p-layer is obtained. For intermediate conditions, an insulating stoichiometric Cr2O3 is identified at 850 °C for a p(O2) of 10-13 atm. The TEM investigation reveals a duplex morphology for every scales: an equiaxed (resp. columnar) morphology has been developed in the internal (resp. external) part. Between these two subscales, a textured chromia layer has been identified as the first layer to form. Finally, the association of TEM and PEC techniques permits the identification of major point defects. It is revealed that the morphology is only linked to the growth direction: anionic (resp. cationic) growth leads to equiaxed (resp. columnar) grains.

On the growth, orientation and hardness of chemical vapor deposited Ti(C,N)

Chemical vapor deposition (CVD) of Ti(C,N) from a reaction gas mixture of TiCl4, CH3CN, H2 and N2 was investigated with respect to gas phase composition and kinetics. The gas phase composition was modelled by thermodynamic calculations and the growth rate of the CVD process was measured when replacing H2 for N2 while the sum of partial pressures H2+N2 was kept constant. The N2/H2 molar ratio was varied from 0 to 19. Single crystal c-sapphire was used as substrates. It was found that low molar ratios (N2/H2 molar ratio below 0.6) lead to an increased Ti(C,N) growth rate with up to 22%, compared to deposition without added N2. The mechanism responsible for the increased growth rate was attributed to the formation and increased gas phase concentration of one major growth species, HCN, in the gas phase. The texture of the Ti(C,N) films were also studied. ⟨211⟩ textured layers were deposited at N2/H2 molar ratios below 9. At higher molar ratios, ⟨111⟩ oriented Ti(C,N) layers were deposited and the grain size increased considerably. The films deposited at a N2/H2 ratio above 9 exhibited superior hardness, reaching 37GPa. The increased hardness is attributed to an almost epitaxial orientation between the layer and the substrate. The Ti(C,N) layers were characterized by elastic recoil detection analysis, X-ray photo electron spectroscopy, scanning electron microscopy, X-ray diffraction and nanoindentation.

Remote sensing of species diversity using Landsat 8 spectral variables

The application of remote sensing in biodiversity estimation has largely relied on the Normalized Difference Vegetation Index (NDVI). The NDVI exploits spectral information from red and near infrared bands of Landsat images and it does not consider canopy background conditions hence it is affected by soil brightness which lowers its sensitivity to vegetation. As such NDVI may be insufficient in explaining tree species diversity. Meanwhile, the Landsat program also collects essential spectral information in the shortwave infrared (SWIR) region which is related to plant properties. The study was intended to: (i) explore the utility of spectral information across Landsat-8 spectrum using the Principal Component Analysis (PCA) and estimate alpha diversity (α-diversity) in the savannah woodland in southern Africa, and (ii) define the species diversity index (Shannon (H′), Simpson (D2) and species richness (S) – defined as number of species in a community) that best relates to spectral variability on the Landsat-8 Operational Land Imager dataset. We designed 90 m × 90 m field plots (n=71) and identified all trees with a diameter at breast height (DbH) above 10 cm. H′, D2 and S were used to quantify tree species diversity within each plot and the corresponding spectral information on all Landsat-8 bands were extracted from each field plot. A stepwise linear regression was applied to determine the relationship between species diversity indices (H′, D2 and S) and Principal Components (PCs), vegetation indices and Gray Level Co-occurrence Matrix (GLCM) texture layers with calibration (n=46) and test (n=23) datasets. The results of regression analysis showed that the Simple Ratio Index derivative had a higher relationship with H′, D2 and S (r2=0.36; r2=0.41; r2=0.24 respectively) compared to NDVI, EVI, SAVI or their derivatives. Moreover the Landsat-8 derived PCs also had a higher relationship with H′ and D2 (r2 of 0.36 and 0.35 respectively) than the frequently used NDVI, and this was attributed to the utilization of the entire spectral content of Landsat-8 data. Our results indicate that: (i) the measurement scales of vegetation indices impact their sensitivity to vegetation characteristics and their ability to explain tree species diversity; (ii) principal components enhance the utility of Landsat-8 spectral data for estimating tree species diversity and (iii) species diversity indices that consider both species richness and abundance (H′ and D2) relates better with Landsat-8 spectral variables.

Application of Multilayer Perceptron with Automatic Relevance Determination on Weed Mapping Using UAV Multispectral Imagery.

Remote sensing techniques are routinely used in plant species discrimination and of weed mapping. In the presented work, successful Silybum marianum detection and mapping using multilayer neural networks is demonstrated. A multispectral camera (green-red-near infrared) attached on a fixed wing unmanned aerial vehicle (UAV) was utilized for the acquisition of high-resolution images (0.1 m resolution). The Multilayer Perceptron with Automatic Relevance Determination (MLP-ARD) was used to identify the S. marianum among other vegetation, mostly Avena sterilis L. The three spectral bands of Red, Green, Near Infrared (NIR) and the texture layer resulting from local variance were used as input. The S. marianum identification rates using MLP-ARD reached an accuracy of 99.54%. Τhe study had an one year duration, meaning that the results are specific, although the accuracy shows the interesting potential of S. marianum mapping with MLP-ARD on multispectral UAV imagery.

ASSESSMENT OF MULTIBEAM BACKSCATTER TEXTURE ANALYSIS FOR SEAFLOOR SEDIMENT CLASSIFICATION

Abstract. Recently, there have been many debates to analyse backscatter data from multibeam echosounder system (MBES) for seafloor classifications. Among them, two common methods have been used lately for seafloor classification; (1) signal-based classification method which using Angular Range Analysis (ARA) and Image-based texture classification method which based on derived Grey Level Co-occurrence Matrices (GLCMs). Although ARA method could predict sediment types, its low spatial resolution limits its use with high spatial resolution dataset. Texture layers from GLCM on the other hand does not predict sediment types, but its high spatial resolution can be useful for image analysis. The objectives of this study are; (1) to investigate the correlation between MBES derived backscatter mosaic textures with seafloor sediment type derived from ARA method, and (2) to identify which GLCM texture layers have high similarities with sediment classification map derived from signal-based classification method. The study area was located at Tawau, covers an area of 4.7 km2, situated off the channel in the Celebes Sea between Nunukan Island and Sebatik Island, East Malaysia. First, GLCM layers were derived from backscatter mosaic while sediment types (i.e. sediment map with classes) was also constructed using ARA method. Secondly, Principal Component Analysis (PCA) was used determine which GLCM layers contribute most to the variance (i.e. important layers). Finally, K-Means clustering algorithm was applied to the important GLCM layers and the results were compared with classes from ARA. From the results, PCA has identified that GLCM layers of Correlation, Entropy, Contrast and Mean contributed to the 98.77 % of total variance. Among these layers, GLCM Mean showed a good agreement with sediment classes from ARA sediment map. This study has demonstrated different texture layers have different characterisation factors for sediment classification and proper analysis is needed before using these layers with any classification technique.

Face aging effect simulation model based on multilayer representation and shearlet transform

In order to extract detailed facial features, we build a face aging effect simulation model based on multilayer representation and shearlet transform. The face is divided into three layers: the global layer of the face, the local features layer, and texture layer, which separately establishes the aging model. First, the training samples are classified according to different age groups, and we use active appearance model (AAM) at the global level to obtain facial features. The regression equations of shape and texture with age are obtained by fitting the support vector machine regression, which is based on the radial basis function. We use AAM to simulate the aging of facial organs. Then, for the texture detail layer, we acquire the significant high-frequency characteristic components of the face by using the multiscale shearlet transform. Finally, we get the last simulated aging images of the human face by the fusion algorithm. Experiments are carried out on the FG-NET dataset, and the experimental results show that the simulated face images have less differences from the original image and have a good face aging simulation effect.

Meso to Neoproterozoic layered mafic-ultramafic rocks from the Virorco back-arc intrusion, Argentina

The Virorco layered mafic-ultramafic intrusion is part of a belt that extends over 100 km from NE to SW in the Eastern Sierras Pampeanas of San Luis, Argentina. The rocks of this belt carry a Fe-Cu-Ni sulphide mineralization in veins and as disseminated and massive ore. Platinum group minerals are associated with the sulphides.The Virorco intrusion exhibits modal, textural and cryptic layering. New results allow the characterization of six layered units (Modal Layered Unit, Pyroxenitic Macro-Layered Unit, Gabbroic Unit, Banded Unit, Hornblende Norite Unit and Gabbronorite Unit) present in three sectors of the intrusion (Eastern, Central and Western). The units from the Western Sector (Banded Unit, Hornblende Norite Unit and Gabbronorite Unit) and the Modal Layered Unit from the Eastern Sector belong to the Marginal Border Series of the intrusion. Meanwhile, the Central sector units (Pyroxenitic Macro-Layered Unit and Gabbroic Unit) are from the Layered Series. The presence of crescumulate texture (Modal Layered Unit) and colloform banding (Banded Unit) are evidences of “in situ” crystallization due to supercooling of a MgO-rich hydrated mafic magma, where cooling proceeded from the walls towards the interior of the magma chamber.In previous studies the mafic-ultramafic rocks have been considered to be Cambrian to Ordovician. Here we present a Sm-Nd whole rock isochron which shows that the formation age of these intrusions is 1002 ± 150 Ma and that the protolith age of the Pringles Metamorphic Complex metasedimentary rocks is 1289 ± 97 Ma. Our study also indicates that the San Luis mafic-ultramafic layered intrusives most probably formed in a back-arc tectonic setting, from an enriched sub-continental mantle, influenced by a subducting slab and/or crust injection into the Pampia Terrane prior to its collision with the Rio de la Plata Craton.

Combination of Functional Nanoengineering and Nanosecond Laser Texturing for Design of Superhydrophobic Aluminum Alloy with Exceptional Mechanical and Chemical Properties.

Industrial application of metallic materials is hindered by several shortcomings, such as proneness to corrosion, erosion under abrasive loads, damage due to poor cold resistance, or weak resistance to thermal shock stresses, etc. In this study, using the aluminum-magnesium alloy as an example of widely spread metallic materials, we show that a combination of functional nanoengineering and nanosecond laser texturing with the appropriate treatment regimes can be successfully used to transform a metal into a superhydrophobic material with exceptional mechanical and chemical properties. It is demonstrated that laser chemical processing of the surface may be simultaneously used to impart multimodal roughness and to modify the composition and physicochemical properties of a thick surface layer of the substrate itself. Such integration of topographical and physicochemical modification leads to specific surface nanostructures such as nanocavities filled with hydrophobic agent and hard oxynitride nanoinclusions. The combination of superhydrophobic state, nano- and micro features of the hierarchical surface, and the appropriate composition of the surface textured layer allowed us to provide the surface with the outstanding level of resistance of superhydrophobic coatings to external chemical and mechanical impacts. In particular, experimental data presented in this study indicate high resistance of the fabricated coatings to pitting corrosion, superheated water vapor, sand abrasive wear, and rapid temperature cycling from liquid nitrogen to room temperatures, without notable degradation of superhydrophobic performance.

Magnetic granularity in pulsed laser deposited YBCO films on technical templates at 5 K

The manifestation of granularity in the superconducting properties of pulsed laser deposited YBCO films on commercially available metallic templates was investigated by scanning Hall probe microscopy at 5 K and was related to local orientation mapping of the YBCO layer. The YBCO films on stainless steel templates with a textured buffer layer of yttrium stabilized ZrO2 grown by alternating beam assisted deposition have a mean grain size of less than with a sharp texture. This results in a homogeneous trapped field profile and spatial distribution of the current density. On the other hand, YBCO films on biaxially textured NiW substrates show magnetic granularity that persists down to a temperature of 5 K and up to an applied magnetic field of 4 T. The origin of the granular field profile is directly correlated to the microstructural properties of the YBCO layer adopted from the granular NiW substrate which leads to a spatially inhomogeneous current density. Grain-to-grain in-plane tilts lead to grain boundaries that obstruct the current while out-of-plane tilts mainly affect the grain properties, resulting in areas with low . Hence, not all grain boundaries cause detrimental effects on since the orientation of individual NiW grains also contributes to observed inhomogeneity and granularity.

Indium-doped ZnO nanorods grown on Si (1 1 1) using a hybrid ALD-solvothermal method

Atomic layer deposition (ALD) followed by microwave hydrothermal processing was successfully employed for producing doped and vertically aligned ZnO nanorod arrays with different aspect ratio. Firstly, a textured ZnO layer with preferential orientation normal to the c-axis was formed on substrate (1 1 1) silicon single crystals by means of the ALD technique. This was achieved through the decomposition of diethylzinc at 190 °C and 3.289 × 10−4 atm, which provided an adequate template with nucleation sites, favoring further growth of vertical nanorods. Subsequently, nanorod array growth was produced on the same surfaces through solvothermal synthesis using as promoter a solution of Zn(NO3)2. In addition, growth of indium-doped ZnoO nanorods over the substrates was produced by using In(CH3COO)3 as a doping agent. The method presented allows good quality ZnO and Zn1−xInxO thin films to be obtained. Photoluminiscence spectra show clear evidence of the inclusion of indium in the ZnO matrix. The higher intensity ratio Zn0.96In0.4O/ZnO was increased 40-fold, demonstrating such an effect.