Texture Function Research Articles

Evaporative Crystallization in Drops on Superhydrophobic and Liquid-Impregnated Surfaces.

Mineral-fouling induced corrosion and deterioration of marine vessels, aircraft, and coastal structures is due in part from structural intrusion of crystals grown from ocean-generated saline drops. As such, much work has explored surface treatments that induce hydrophobicity or introduce barriers for antifouling and corrosion prevention; however, the efficacy of these strategies will be altered by the underlying substrate texture. Here, we study the behavior of evaporating saline drops on superhydrophobic and liquid-impregnated surfaces as a function of surface texture. On superhydrophobic surfaces, four disparate regimes (which are not observed for particle-laden drops) emerge as a function of the substrate solid fraction: Cassie-pinning, Cassie-gliding, Cassie-Wenzel transition, and Wenzel. These regimes control the morphology of the resultant crystal deposits. In contrast to the superhydrophobic surfaces, spreading liquid-impregnated surfaces demonstrate minimal influence of solid fraction on evaporative crystallization. The area, area localization, timescale of evaporation, and deposit morphology are all normalized by the presence of the lubricating layer, thus introducing an efficient method of eliminating crystal "coffee rings" as well as reducing the potential for fouling and corrosion.

Modeling microstructural evolution in irradiated materials with cluster dynamics methods: A review

As both the design of material systems for nuclear energy applications and the number of reactor designs being proposed increase the need for material models predicting the evolution of microstructures as a function of chemistry, texture, grain size, precipitate content, etc., and irradiation conditions is steadily increasing. This manuscript aims at presenting a review of the different cluster dynamics modeling schemes that have emerged worldwide over the past decade(s). Further, the manuscript also critically discusses limitations in existing approaches and identifies potential routes for future developments.

Rapid material capture through sparse and multiplexed measurements

Among the many models for material appearance, data-driven representations like bidirectional texture functions (BTFs) play an important role as they provide accurate real-time reproduction of complex light transport effects such as interreflections. However, their acquisition involves time-consuming capturing of many thousands of bidirectional samples in order to avoid interpolation artifacts. Furthermore, high dynamic range imaging including many and long exposure steps is necessary in the presence of low albedo or self-shadowing. So far, these problems have been dealt with separately by means of sparse reconstruction and multiplexed illumination techniques, respectively. Existing methods rely on data-driven models learned on data that has been range-reduced in a way that made their simultaneous application impossible. In this paper, we address both problems at once through a novel method for learning data-driven appearance models, based on moving the dynamic range reduction from the data to the metric. Specifically, we learn models by minimizing the relative L2 error on the original data instead of the absolute L2 error on range-reduced data. We demonstrate that the models thus obtained allow for faithful reconstruction of material appearance from sparse and illumination-multiplexed measurements, greatly reducing both the number of images and the shutter times required. As a result, we are able to reduce acquisition times down to the order of minutes from what used to be the order of hours.

Activated carbon from Bulgarian peach stones as a support of catalysts for methanol decomposition

This study is aimed at the development of intelligent integrated scheme for full utilization of biomass for clean energy production. The proposed approach includes production of activated carbon based catalysts for methanol decomposition as a source of hydrogen, where both activated carbon and methanol, could be produced from biomass. In order to elucidate the impact of different activated carbon characteristics on the formation of the catalytic active phase, carbons with different texture and surface functionality are purposely obtained by changes in the activation temperature during the carbon preparation and its post-synthetic treatment with nitric acid. Peach stones, widely available in Bulgaria and Balkans region, are chosen as activated carbons precursor. Iron, zinc and ferrite modifications of thus obtained carbons are prepared by incipient wetness impregnation technique and nitrogen physisorption, XRD, HRTEM, UV-Vis, FTIR, Moessbauer spectroscopy, TPR with hydrogen and Boehm method are used for samples characterization. It is established that the state and catalytic activity of the supported metal oxide particles could be easily controlled by the procedure of the activated carbon preparation and this effect strongly depends on the nature of the loaded metal oxide. In case of iron modifications, the increase of the activation temperature during the carbon preparation promotes the formation of more finely dispersed, accessible for the reactants and active in methanol decomposition magnetite particles. The dispersion and the accessibility of the zinc oxide species in zinc modifications are improved by the formation of additional amount of surface acidic groups during the carbon pre-treatment with nitric acid. The combination of lower temperature of carbon activation with nitric acid pre-treatment promotes the formation of highly active ferrite nanoparticles in the binary modifications.

Grazing altered carbon exchange in a dry mixedgrass prairie as a function of soil texture

How soil carbon dioxide (CO2) and methane (CH4) fluxes and above- and belowground C respond to grazing management across a grassland landscape is poorly understood. Thus, we quantified soil CO2 and CH4 fluxes, and above- and belowground C, for sandy loam and loamy sand soils within a dry mixed-grass prairie subjected to annual rotational cattle grazing (grazed) since 1970 or grazing exclusion for 4 yr (rested). Gas samples were collected weekly (May to October). The CO2 flux was 24% greater from the rested than grazed sandy loam. Higher CO2 fluxes from the rested than grazed sandy loam were associated with 49% and 68% greater water-extractable organic C concentrations in May and July, respectively, a 34% greater soil organic C concentration, and 88% greater peak aboveground vegetation C. In contrast, the rested and grazed loamy sand had similar CO2 flux and above- and belowground C, but 16% more CH4 uptake occurred in the grazed than rested. Across soil textures, water-filled pore space (WFPS) explained 5...

The fusion of multispectral palmprints using the information set based features and classifier

This paper presents three texture features, viz., topothesy-fractal dimension, Hanman transform, and structure function based transform for the multispectral palmprint based authentication. It introduces the notion of information set originating from the Hanman–Anirban entropy. Using information set, Hanman transform features are derived. The topothesy-fractal dimension features arise from the structure function on representing the intensity variation on the texture surface. The structure function based transform features are derived from both structure function and the Hanman transform. Apart from the feature extraction, the fuzzy classifier based on the information processing is also developed. A novel score level fusion is proposed using Triangular-norms and Triangular-conorms. Thus the paper’s contribution is three-fold: i) New features for multispectral palmprint, ii) novel classifier for authentication, and iii) score level fusion for improving the accuracy. The rigorous experimental results certify that the proposed approaches make a substantial improvement in the authentication accuracy and outperform the contemporary approaches.

Woven Fabric Model Creation from a Single Image

We present a fast, novel image-based technique for reverse engineering woven fabrics at a yarn level. These models can be used in a wide range of interior design and visual special effects applications. To recover our pseudo-Bidirectional Texture Function (BTF), we estimate the three-dimensional (3D) structure and a set of yarn parameters (e.g., yarn width, yarn crossovers) from spatial and frequency domain cues. Drawing inspiration from previous work [Zhao et al. 2012], we solve for the woven fabric pattern and from this build a dataset. In contrast, however, we use a combination of image space analysis and frequency domain analysis, and, in challenging cases, match image statistics with those from previously captured known patterns. Our method determines, from a single digital image, captured with a digital single-lens reflex (DSLR) camera under controlled uniform lighting, the woven cloth structure, depth, and albedo, thus removing the need for separately measured depth data. The focus of this work is on the rapid acquisition of woven cloth structure and therefore we use standard approaches to render the results. Our pipeline first estimates the weave pattern, yarn characteristics, and noise statistics using a novel combination of low-level image processing and Fourier analysis. Next, we estimate a 3D structure for the fabric sample using a first-order Markov chain and our estimated noise model as input, also deriving a depth map and an albedo. Our volumetric textile model includes information about the 3D path of the center of the yarns, their variable width, and hence the volume occupied by the yarns, and colors. We demonstrate the efficacy of our approach through comparison images of test scenes rendered using (a) the original photograph, (b) the segmented image, (c) the estimated weave pattern, and (d) the rendered result.

Algorithms and software for areal surface texture function parameters

Software for the evaluation of areal surface texture function parameters is described. Definitions of the parameters, expressed in terms of the inverse areal material ratio function, are provided along with details of the numerical algorithms employed in the software to implement calculations to evaluate approximations to the parameters according to those definitions. Results obtained using the software to process a number of data sets representing different surfaces are compared with those returned by proprietary software for surface texture measurement. Differences in the results, arising from different choices being made when implementing the steps in the parameter evaluation process, are discussed.

Optomechanical design of rotary kaleidoscope for bidirectional texture function acquisition.

Optical systems are traditionally used for accurate recording and measurement of the real world's appearance. Present techniques allow us to form a computer-based virtual world, which is used in a variety of technical fields. The crucial issue for future applications of virtual reality is the fidelity of rendered images to real-world objects. This is strongly affected by the appearance of the rendered object's surfaces. Currently, the most applied method of describing a surface's visual appearance of spatially nonuniform surfaces is bidirectional texture function (BTF). We have designed, optimized, built, and tested a unique portable instrument based on a rotary kaleidoscope principle for BTF acquisition in situ. To the best of our knowledge, such an instrument has never been used before to measure BTF of a surface. We enhanced a common static kaleidoscope by adding rotation, which allows us to get a larger number of images of the sample for more combinations of illumination directions and viewing directions. This results in a higher directional and spatial resolution of measured BTF data. In this paper, we focus on the optomechanical design of the rotary BTF measurement instrument and issues related to its alignment to keep the desired mechanical precision.

Repair of soft tissue defect in distal thumb with dorsal thumb neurocutaneous vascular flap

Objective To evaluate the surgical methods and clinical effects of the reconstruction of soft tissue defect in distal thumbwith dorsal thumb neurocutaneous vascular flap. Methods From January, 2014 to December, 2016, 32 patients with soft tissue defects of distal thumb were repaired with dorsal thumb neurocutaneous vascular flaps, including left thumbs in 11 cases and right thumbs in 21 cases. They were including 7 cases of nail bed defects, 9 cases of pulp defects under nails, 16 cases ofthe defects of tips or stump of fingers; skin and soft tissue defects range of 1.5 cm×1.0 cm-3.5 cm×3.2 cm; Flap cutting areas range of 2.0 cm×1.5 cm-4.0 cm×3.5 cm. If the donor areas could be sutured directly, be sutured; if they could not, be covered with intermediate split thickness skin grafts. All patients were followed up when they were reviewed in outpatient department, and to be evaluated the shape, texture, sensation, flexion and extension function, and donor site of the flaps. Results One case of flaps blood circulation disordereddue to tight suture, and eased after the removal of part of the sutures; One case of flaps atrophied, and the phalangette was exposed after 3 months, so we removed the end part of bone and the wound was closed; other flaps were survived, with primary wound healing. In the total 32 patients, they were followed up range of 3 to 36 months,with an average of 12 months. Eighteen cases were followed up at least 6 months, which were 4 of the 7 cases of nail bed defects, 5 of the 9 cases of pulp defects under nail and 9 of the 16 cases of the defects of tip or stump of fingers. The appearances and textures of flaps were good, protective sensations were restored, and skin flap two-point discrimina-tionswere 8-10 mm. According to the Trial Standard for Evaluation of Upper Limb Function of Chinese Society of Hand Surgery, it was excellent in 11 cases, good in 17 cases and moderate in 4 cases, with the excellent and good rate of 87.5%. Conclusion It has advantages of simple operation, low risk, high success rate and satisfactory curative effects of the use of dorsal thumb neurocutaneous vascular flap for repair of distal thumb defect of skin and soft tissue. It is not only suitable for the hospital with good technical and equipment, but also suitable for the primary hospital. Key words: Finger injury; Thumb; Neurocutaneous vascular flap; Microsurgical operation

Temperature- and texture-dependent dielectric model for frozen and thawed mineral soils at a frequency of 1.4 GHz

A single-frequency dielectric model at 1.4GHz for frozen mineral soils was developed, with the temperature and gravimetric clay content varying from −1 to −30°C and from 9.1 to 41.3%, respectively. The model is based on the refractive mixing dielectric model and the dielectric data measured for the three typical soils collected in the Yamal tundra. The refractive mixing dielectric model was applied to fit the measured dielectric data as a function of soil moisture at a number of fixed temperatures. As a result, the parameters of the developed model were derived as a function of temperature and texture. This set of parameters consists of the maximum gravimetric fraction of unfrozen bound water and the values of the complex refractive indexes relating to soil solids, unfrozen bound water, and moistened ice. The developed model for frozen mineral soils in conjunction with the previously developed by us dielectric model for thawed mineral soils is considered as an integral dielectric model which is applicable for permittivity calculations of soil in both thawed and frozen states.The developed integral dielectric model for frozen and thawed mineral soils was validated using the dielectric data for five measured soils, and the statistical errors were estimated in terms of the root mean square error and the determination coefficient. In addition, the only known in the literature dielectric model for frozen soils suggested by Zhang was validated based on dielectric data for soils measured in this research. The comparative analysis proved substantially better accuracy of predictions in the case of the developed model as compared to those related to the Zhang model.

Statistical process control applied to mechanized peanut sowing as a function of soil texture.

The successful establishment of agricultural crops depends on sowing quality, machinery performance, soil type and conditions, among other factors. This study evaluates the operational quality of mechanized peanut sowing in three soil types (sand, silt, and clay) with variable moisture contents. The experiment was conducted in three locations in the state of São Paulo, Brazil. The track-sampling scheme was used for 80 sampling locations of each soil type. Descriptive statistics and statistical process control (SPC) were used to evaluate the quality indicators of mechanized peanut sowing. The variables had normal distributions and were stable from the viewpoint of SPC. The best performance for peanut sowing density, normal spacing, and the initial seedling growing stand was found for clayey soil followed by sandy soil and then silty soil. Sandy or clayey soils displayed similar results regarding sowing depth, which was deeper than in the silty soil. Overall, the texture and the moisture of clayey soil provided the best operational performance for mechanized peanut sowing.

Textural applications of power chords in Scandinavian death metal

Abstract The purpose of this research is to explore a concretely analytical approach to power chords and harmonic structure in Scandinavian death metal. While often approached from sociological or anthropological perspectives, traditional music theory tends to be overlooked in the study of metal. While many harmonic progressions in death metal do err on the side of being more simplistic in nature, the textural changes and unexpected harmonic shifts help to create recognizable idioms of the genre. Using thorough harmonic and melodic analyses of Viking metal, melodic death metal and folk metal examples, conclusions can be drawn about the similarities and differences in power chord usage throughout them. There are also definite links between Western art music and death metal, most notably in harmonic function, form and manipulation of texture for a desired effect. Distinct emphasis on virtuosity and soloistic playing is also characteristic of death metal, which is where it diverts from similarities to Rock and other pop genres, despite their shared superficial harmonic simplicity. This project provides insight into how power chords in context are used to create the quintessential ‘metal’ sound and how the genre thrives off of subtle alterations to the listener’s expectations of traditional tonal harmony. Harmonic analyses focussing on the use of power chords and resultant textural changes show that consistent compositional idioms of metal can be isolated across Scandinavian subgenres and will ultimately provide a basis for further analytical research.

An Overview of Wild Edible Fungi Resource Conservation and Its Utilization in Yunnan

As one of the province with the most abundant bio-diversity in China, Yunnan is also one of the most-concerned region in the world which is famous for its bio-diversity. The wild edible fungi resources in Yunnan are extremely rich and diverse, which account for nearly 40.7% of the world’s known resources and 90% of China’s known resource respectively. Serving as one important type of forest understory resource and product, the wild edible fungi has a large market due to its unique flavor, texture or special health care function. Therefore, sustainable utilization of the wild edible fungi resource is of paramount importance to develop the rural livelihood and furthermore conserve forest and animal resources in Yunnan. Integrating a large number of previous researches, this paper has summarized the current situations of edible fungi resources as well as the existing problems on production, food, medicine utilization, processing, trade and resource conservation inYunnan. Data showed that the wild edible fungi resources are playing extremely important roles on the peasant household incomes in the vast mountainous areas in Yunnan. For example, the fungi collection incomes can account for 50% to 80% of the household income in Xishuangbanna. However, the wild edible fungi resources are facing the problems of the reductions in resource types and quantities, unclear ownership, improper collection and conservation measures, unscientific management as well as other outstanding issues. The author point out that it is quite essential to clear the ownership, implement the community-based conservation strategies as well as to strengthen the researches on the scientific collection, conservation and breeding technologies in order to solve the problems in the effective conservation and sustainable utilization of the wild edible fungi resources in the future.

Simulating painted appearance of BTF materials

Bidirectional texture function (BTF) provides a realistic representation for real-world materials; however, the representation does not allow users to append additional rendering effects to the BTF data in a simple and effective way. In this paper, we present an approach for generating the painted appearance on a material that is represented by a BTF. We first convert a BTF into a physical representation composed of a height-field and a spatially varying bidirectional reflectance distribution function (SVBRDF). This representation allows us to simulate the appearance of paints on the surface of a material by computing the reflectance and the height field of the painted material. During rendering, we combine an existing BTF rendering approach and the modified material data to simulate the painted appearance of the BTF materials. Our experiments show that the proposed approach can simulate the painted appearance of a material while preserving the characteristic appearance of the original BTF. Our approach is mainly suitable for less specular BTF materials that allow depth reconstruction.

Investigation of the shear response and geometrically necessary dislocation densities in shear localization in high-purity titanium

The influence of microstructural anisotropy on shear response of high-purity titanium was studied using the compact forced-simple-shear specimen (CFSS) loaded under quasi-static loading conditions. Post-mortem characterization reveals significant difference in shear response of different directions in the same material due to material crystallographic texture anisotropy. Shear bands are narrower in specimens in which the shear zone is aligned along the direction with a strong {0001} basal texture. Twinning was identified as an active mechanism to accommodate strains in the shear region in both orientations. This study confirms the applicability of the CFSS design for the investigation of differences in the shear response of materials as a function of process-induced crystallographic texture. A detailed, systematic approach to quantifying shear band evolution by evaluating geometrically necessary dislocations (GND) associated with crystallographic anisotropy is presented. The results show that: i) line average GND density profiles, for Ti samples that possess a uniform equiaxed-grain structure, but with strong crystallographic anisotropy, exhibit significant differences in GND density close to the shear band center; ii) GND profiles decrease steadily away from the shear band as the plastic strain diminishes, in agreement with Ashby's theory of work hardening, where the higher GND density in the through-thickness (TT) orientation is a result of restricted <a> type slip in the shear band compared with in-plane (IP) samples; iii) the anisotropy in deformation response is derived from initial crystallographic texture of the materials, where GND density of <a> GNDs are higher adjacent to the shear band in the through-thickness sample oriented away from easy slip, but the density of <c+a> type GNDs are very similar in these two samples; and iv) the increase in grain average GND density was determined to have strong correlation to an increase in the Euler Φ angle of the grain average orientation, indicating an increased misorientation angle evolution.

DC switching of bistable textures in HAN cells with bistable surfaces fabricated using the oblique UV optical alignment technique

ABSTRACTBistable surfaces for liquid crystal (LC) alignment were fabricated. A polyimide alignment film, which performed as a weak anchoring force film, was used, and the oblique-photo alignment method was used as an alignment process. Hybrid aligned nematic (HAN) cells with in-plane electrodes were assembled for inducing a flexoelectric polarization. The LC material was injected into the empty cells. When the polarization of the electric field was switched, the LC textures achieved polarity switching. In addition, the memory function of the LC texture was confirmed. Further, the application possibility for bistable liquid-crystal displays was shown using asymmetrically shaped electrode patterns.

Bidirectional texture function image super-resolution using singular value decomposition.

The bidirectional texture function (BTF) is widely employed to achieve realistic digital reproduction of real-world material appearance. In practice, a BTF measurement device usually does not use high-resolution (HR) cameras in data collection, considering the high equipment cost and huge data space required. The limited image resolution consequently leads to the loss of texture details in BTF data. This paper proposes a fast BTF image super-resolution (SR) algorithm to deal with this issue. The algorithm uses singular value decomposition (SVD) to separate the collected low-resolution (LR) BTF data into intrinsic textures and eigen-apparent bidirectional reflectance distribution functions (eigen-ABRDFs) and then improves the resolution of the intrinsic textures via image SR. The HR BTFs can be finally obtained by fusing the reconstructed HR intrinsic textures with the LR eigen-ABRDFs. Experimental results show that the proposed algorithm outperforms the state-of-the-art single-image SR algorithms in terms of reconstruction accuracy. In addition, thanks to the employment of SVD, the proposed algorithm is computationally efficient and robust to noise corruption.

Multiferroic effect of multilayer low-distorted doped bismuth ferrite thin films as a function of sputtering power and crystallographic texture

Low-distortion rhombohedral multilayer barium-nickel co-doped BiFeO3 (Bi0.75Ba0.25Fe0.975Ni0.025O3) multiferroic thin films were grown on Pt/TiO2/SiO2/Si substrates by reactive RF magnetron sputtering, as a function of sputtering power. X-ray diffraction showed that Bi0.75Ba0.25Fe0.975Ni0.025O3 multilayer films have a pseudocubic-type structure. Piezoresponse force microscopy demonstrated polarization switching in all films at room temperature. Scanning electron microscopy showed different morphologies depending on the sputtering power used during the deposition process and that the thickness of the film decreases from about 142 nm to 72 nm as the sputtering power decreases. Magnetization results showed that as the thickness of the film decreases, the magnetization of the film increases. Thus, there is a direct relation between the sputtering power, thickness and the magnetization of the film. A direct relation between in-plane residual stress and thin film thickness has been obtained. This causes the main axe of the BO6 octahedra to be tilted from 90 to 45° (from thin-film surface) by a texture crystal volume of 29 and 18% in the (012) and (110) crystallographic planes respectively.

Lightdrum-Portable Light Stage for Accurate BTF Measurement on Site.

We propose a miniaturised light stage for measuring the bidirectional reflectance distribution function (BRDF) and the bidirectional texture function (BTF) of surfaces on site in real world application scenarios. The main principle of our lightweight BTF acquisition gantry is a compact hemispherical skeleton with cameras along the meridian and with light emitting diode (LED) modules shining light onto a sample surface. The proposed device is portable and achieves a high speed of measurement while maintaining high degree of accuracy. While the positions of the LEDs are fixed on the hemisphere, the cameras allow us to cover the range of the zenith angle from 0 to 75 and by rotating the cameras along the axis of the hemisphere we can cover all possible camera directions. This allows us to take measurements with almost the same quality as existing stationary BTF gantries. Two degrees of freedom can be set arbitrarily for measurements and the other two degrees of freedom are fixed, which provides a tradeoff between accuracy of measurements and practical applicability. Assuming that a measured sample is locally flat and spatially accessible, we can set the correct perpendicular direction against the measured sample by means of an auto-collimator prior to measuring. Further, we have designed and used a marker sticker method to allow for the easy rectification and alignment of acquired images during data processing. We show the results of our approach by images rendered for 36 measured material samples.