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Ptychography today is considered the most natural and effective method for approaching the diffraction limit of optical resolution. The principal scheme of a ptychoscope does not contain refractive or focusing elements and includes a coherent light source, a platform for moving (macroscopic) object, and a detector for registering radiation passed through or reflected by the object associated with a computer for processing diffraction patterns. In classical optics, the main task in achieving high spatial resolution is the correction and elimination of aberrations of optical systems, while in ptychography spatial resolution mainly depends on the reliability of registration and computer processing of diffraction patterns with large numerical apertures. The key idea of ptychography is to obtain an image by computer processing of overlapping diffraction patterns (scans). When moving the object it is assumed that the illuminating beam and the position of the detector remain unchanged. Ptychography is used in a wide range of radiation wavelengths from infrared to X-ray, and it is possible to do without imaging optics. In this work, the possibility of obtaining an amplitude-phase image of the surface relief of an object inclined to the incident one was studied. [ABSTRACT FROM AUTHOR]

Modern tribology makes it possible to correctly calculate, diagnose, predict and select appropriate materials for friction pairs, to determine the optimal mode of operation of the tribo-joint. The main parameter for solving friction problems and other problems of tribology is the topography of the surface. The main purpose of the models in these tasks is to display the tribological properties of engineering surfaces. In the framework of the classical approach, the topography of the surface is studied on the basis of its images from the point of view of functional and statistical characteristics: the evaluation of the functional characteristics is based on the maximum roughness along the height and the average roughness along the center line, and the statistical characteristics are estimated using the power spectrum or the autocorrelation function. However, these characteristics are not only surface properties. They depend on the resolution of the device for measuring the surface geometry and the length of the scan. However, the degree of complexity of a surface shape can be represented by a parameter called the fractal dimension: a higher degree of complexity has a larger value of this parameter. Fractal dimensionality is a characteristic of surface relief and makes it possible to explain tribological phenomena without the influence of resolution. This article provides an overview of mathematical approaches to the description of the relief of engineering surfaces, in particular statistical, stochastic and topological modeling, their limitations, advantages and disadvantages. The implementation of the principles of the theory of fractal structures is discussed, which makes it possible to introduce the degree of imbalance of the tribological system into the analysis of structure formation in the surface and near-surface layers of materials and to describe the development of friction and wear processes. This is the basis for controlling the structure of the surface layers of materials with given properties. The concept of fractals, used for the quantitative description of the dissipative structure of the tribojunction zone, makes it possible to establish a connection between its fractal dimension and mechanical properties, as well as critical states of deformation of metals and alloys. The course of research and stages of fractal modeling, the classification of methods of fractal analysis of the structure of engineering contact surfaces are considered. A critical analysis of modern models based on the energy-spectral density function, which are quite similar to fractal models, is presented. Readers are expected to gain an overview of research developments in existing modeling methods and directions for future research in the field of tribology

Ge1−xSnx growth on a new sapphire platform has been demonstrated. This involved the growth of GeSn on Ge/GaAs layers using the algorithm developed. The resultant growths of Ge on GaAs/AlAs/sapphire and Ge1−xSnx on Ge/GaAs/AlAs/sapphire were investigated by in situ and ex situ characterization techniques to ascertain the surface morphology, crystal structure, and quality. The growth mode of Ge on GaAs was predominantly two-dimensional (2D), which signifies a layer-by-layer deposition, contributing to enhanced crystal quality in the Ge/GaAs system. The growth of Ge1−xSnx with 10% Sn on a graded profile for 30 min shows uniform composition and a strong peak on the reciprocal space map (RSM). On the other hand, the partially relaxed growth of the alloy on RSM was established. [ABSTRACT FROM AUTHOR]

Ge1−xSnx growth on a new sapphire platform has been demonstrated. This involved the growth of GeSn on Ge/GaAs layers using the algorithm developed. The resultant growths of Ge on GaAs/AlAs/sapphire and Ge1−xSnx on Ge/GaAs/AlAs/sapphire were investigated by in situ and ex situ characterization techniques to ascertain the surface morphology, crystal structure, and quality. The growth mode of Ge on GaAs was predominantly two-dimensional (2D), which signifies a layer-by-layer deposition, contributing to enhanced crystal quality in the Ge/GaAs system. The growth of Ge1−xSnx with 10% Sn on a graded profile for 30 min shows uniform composition and a strong peak on the reciprocal space map (RSM). On the other hand, the partially relaxed growth of the alloy on RSM was established.

In planetary turning, with orbital planetary rotation of the tool, regular cellular relief appears on the surface of the machined part. Such surfaces prove effective in frictional pairs. The equipment and tool developed for producing regular relief has been successfully tested on aluminum alloy linings of slip bearings. In particular, a special prismatic cutter compatible with the proposed equipment is described. The kinematics of creating cellular relief is studied. Specifically, the influence of the rotary cutting speed and the supply on the quality of the relief is investigated. [ABSTRACT FROM AUTHOR]

A new variant of manufacturing high-frequency holographic gratings with a spatial frequency up to 1500 mm–1 on layers of dichromated gelatin (DCG), in the processing technology of which water procedures are completely excluded, is proposed. The method is based on the use of glacial acetic acid after the photodestruction of layers by exposure to short-wave UV radiation instead of the standard method of processing holographic structures registered by coherent He–Cd laser radiation. In the course of the experiments, relief-phase holographic gratings with high diffraction efficiency up to 64% were obtained, regardless of the thickness of the DCG layers. [ABSTRACT FROM AUTHOR]

Digital holographic microscopy (DHM) was employed to investigate the formation process and shape evolution of the most frequently observed bainite variant pairs in low-carbon alloy steel. Through in-situ observation coupled with theoretical predictions, the continuous changes in surface relief corresponding to bainite and adjacent austenite were measured. Additionally, the crystal orientations of the observed variant pairs were determined using electron backscattered diffraction (EBSD). The results indicated that at the onset of the transformation, the bainite variant shape agreed with theoretical predictions, while the adjacent austenite experienced plastic deformation. However, as the transformation proceeded towards completion, the shape of some bainite variants deviated from the theoretical predictions, while their adjacent austenite remained undeformed. This shift of deformation strain between austenite and bainite suggests a change in strain accommodation mechanism. Furthermore, the observed 'tent-shaped' surface relief was attributed to back-to-back mutually accommodating variant pairs, resulting in reduction of the total shape strain, compared to the theoretical prediction. [Display omitted] [ABSTRACT FROM AUTHOR]

The NiTi metallic glass ribbon was subjected to 10-minute annealing at 400°C, 500°C and 600°C to detect changes in the surface relief and its statistical characteristics upon heating. Each annealing mode led to the ribbon crystallization with the formation of the Ni50Ti50 crystalline phases along with the transformation of the surface topography. Multifractal characteristics, such as the width of the singularity spectrum and fractal dimension, were calculated for the surface relief as a function of an annealing temperature. After the annealing at 500°C, along with the stepwise surface structure rearrangements, these parameters had extrema, including a local minimum of the width of the singularity spectrum, indicating a tendency towards monofractalization of the system. Abrupt changes in the parameters calculated by applying the multifractal formalism made it possible to detect the phase transition of the system in the form of its crystallization. [ABSTRACT FROM AUTHOR]

This article presents a review of experimental investigations of changes in the structure and properties of the surface and near-surface layers of various materials (steels, metal alloys, ceramics, and graphite) in the area of a barcode applied by continuous laser radiation and short (nanosecond) and ultrashort (femto- and picosecond) laser pulses. [ABSTRACT FROM AUTHOR]

In this paper, we study the regularities of surface-relief formation, the elemental and phase composition distribution over depth, and an increase in the surface microhardness of steel 45 depending on the parameters of electroexplosive boron-copper plating and subsequent electron-beam processing. The structure of the region of electroexplosive alloying with a thickness of up to 25 μm in depth is shown to include a coating, and surface, intermediate, and boundary layers. At an increase in the absorbed power density and the boron powder weight, the surface roughness of the electroexplosive boron-copper plating region increases while the microhardness increases up to 1400 HV. Subsequent processing by a pulsed electron beam leads to unification of the coating with the surface layer, an increase in the depth of the hardening region to 80 μm and a decrease in the surface roughness and microhardness to 800 HV. Improvement in the physical and mechanical properties of the alloying region is due to the formation of submicrocrystalline and nanocrystalline quenching structures containing hardening phases. [ABSTRACT FROM AUTHOR]

The paper analyzes the surface relief of a tungsten carbide–ferromanganese steel composite (WC–(Fe–Mn–C)) under axial compression, including its structure on the microscale (variation in coherent scattering region sizes and mode II stresses) and on the macroscale (accumulation of deformed WC grains and interface cracks, evolution of ordered shear bands). The analysis shows that compressing the composite decreases the average size of plastically deformed WC grains, increases the density of interface microcracks, and decreases the average shear band spacing. The composite reveals a stage character of deformation and prefracture correlating with its stress–strain curve. In the first strain hardening stage, the material is deformed in its matrix and WC grains without continuity loss. In the second stage, numerous shear macrobands oriented in two directions at ~45° to the loading axis appear on its free surfaces. The macrobands are rich in deformed grains and cracks. Their intersection gives rise to macrocracks of length 40–150 µm as precursors of catastrophic failure. Also presented are X-ray diffraction data on the fine crystal structure of the carbide and binder phases of WC–(Fe–Mn–C) at different loading stages. The data suggests that increasing the strain decreases the size of coherent scattering regions and increases the lattice microstress in both phases. The binder starts to deform earlier than the tungsten carbide. Most of the change in the fine crystal structure of the tungsten carbide falls on the stage of shear band formation. [ABSTRACT FROM AUTHOR]

A new variant of manufacturing high-frequency holographic gratings with a spatial frequency up to 1200 mm–1 on silver halide photographic material for holography PFG-01 is proposed, the processing technology of which is tanning bleaching in bleach containing dichromates and etching in water or in solutions of glacial acetic acid in isopropyl alcohol. The key point is the destructive effect on gelatin of short-wave UV radiation with a wavelength of less than 270 nm. During the experiments, relief-phase holographic gratings with high diffraction efficiency up to a value of 42% were obtained. [ABSTRACT FROM AUTHOR]

Subject and purpose. The paper discusses the extension of the photometric method for the surface relief retrieval from images in the optical and radar wavelengths ranges through the involving of the direct heights measurements by an altimeter onboard the spacecraft. The photometric method allows retrieval the relief which has accuracy and the spatial resolution inherent in initial images. Altimetry provides direct measurements of the surface heights, but to cover the entire study area it requires too many spacecraft passes. The paper considers an altimeter having a wide radiation pattern. Methods and methodology. The paper presents the development of the photometric method for the surface relief retrieval. The main characteristic of the method is the Bayesian statistical approach which allows calculations of the most probable relief from available observational data with mathematical rigour. Results. An expression for the optimal filter which converts source images along with altimetry data into the most probable relief is derived. The efficiency of the method is verified using computer modeling. Conclusion. The statistical approach to processing of experimental data allows optimal combination of surface images and altimeter data properties to obtain the surface relief with high spatial resolution and reference to real heights.

The possibilities of measuring the depth of the surface relief on metallographic microscopes manufactured by OJSC «Optoelectronic systems» are illustrated. For the microscopes MI-1 and MICRO-200 a technique for determining the height of the relief is considered, which is based on the relationship between the angle of rotation of the drum tincture of precise focus and vertical movement of the object table. Examples of crater depth measurements after exposure to laser radiation on a metal surface are given. For MI-1 and MICRO-200 microscopes, the depth of the well was determined as 99.36 and 99.8 µm, respectively, which is consistent with the profilometer data (~100 µm). For a plane-parallel quartz plate, the measurement results were 0.435 µm when determined microscopically, as well as the object-micrometer. The possibility of determining the thickness of titanium nitride coatings by differential interference contrast is considered. The method allows the determination of the thickness of the difference in interference colors, if the image areas are at different heights. The thickness of the coating can be estimated using a nomogram of double refraction.

Subject and purpose. The information obtained from a physical experiment usually is partially degraded by the influence of noise factors. The nature of these factors is dependent on the experiment conditions. But an approach to overcoming this influence is similar in many cases. The researches carried out in the image processing group of IRE NASU for the last ten years were aimed towards searching for the techniques of maximal information extraction from astronomical observation and space experiments. There were several directions of the research. In the context of observations from the surface of the Earth the problems were overcoming of the atmosphere phase distortions and the synthesis of antenna arrays for telescopes and interferometers in different ranges of the electromagnetic spectrum. In the case of space observations we deal with the optimal interpretation problem for their results, in particular the reconstruction of planet surface relief and the processing of images with gravitational lensing effect. Methods and methodology. The common part of all these techniques is using of the statistical approach, i. e. the application of mathematical statistics and the theory of optimal statistical decisions. The common peculiarities of its applications as well as the specific of its application for the certain problems of astronomical image processing are revealed in this paper. Results. As a result the following techniques are developed: the technique of Fourier components phase accumulation for the atmosphere phase noise reduction; the technique for optimal evaluation of the quasar intensity while observing it through a gravitational field of a distant galaxy; the technique for taking into account the altimeter data in photoclinometric reconstruction of a planet surface relief; and a number of techniques of antenna configuration synthesis for telescopes and interferometers. Conclusions. The statistical approach to processing experimental data allows using an information contained in the series of astronomical object images for reconstructing a single, more precise image of this object. It makes possible optimal combining the information from the surface images and the altimeter data for obtaining the surface relief of high resolution with the real values of height. In gravitational lensing images it provides the division of the source of observation from the background. The results demonstrate that the Bayesian statistical approach is the powerful instrument of the research.

Micro/nanoscale textured surfaces have presented promising tissue–implant integration via increasing surface roughness, energy, and wettability. Recent studies indicate that surface texture imparted on the metallic implants via surface relief induced with simple bulk plastic deformation methods (e.g., tension or compression tests) does result in enhanced cell response. Considering these recent findings, this study presents a thorough investigation of the effects of surface relief on surface properties of implants and cell adhesion. Experiments are conducted on the samples subjected to interrupted tensile tests up to the plastic strains of 5, 15, 25, and 35%. Main findings from these experiments suggest that, as the plastic deformation level increases up to 35% from the undeformed (control) level, (1) average surface roughness (Ra) increases from 17.58 to 595.29 nm; (2) water contact angle decreases from 84.28 to 58.07°; (3) surface free energy (SFE) increases from 36.06 to 48.89 mJ/m2; and (4) breast cancer cells show 2.4-fold increased number of attachment. Increased surface roughness indicates the distorted topography via surface relief and leads to increased wettability, consistent with Wenzel’s theory. The higher levels of SFE observed were related to high-energy regions provided via activation of strengthening mechanisms, which increased in volume fraction concomitant with plastic deformation. Eventually, the displayed improvements in surface properties have increased the number of breast cancer cell attachments. These findings indicate that surface relief induced upon plastic deformation processes could be utilized in the design of implants for therapeutic or diagnostic purposes through capturing breast cancer cells on the material surface.

The use of surface relief structures is increasing in the field of optics. A study of photoinduced relief using dichromated gelatin films with different thickness is described in this paper. Two light sources were used: a laser (λ = 468 nm) and an ultraviolet mercury-metal halide lamp. Gratings with low spatial frequencies were contact-copied on the DCG (dichromated gelatin) films. Two development processes were used, one included washing the plates with just water and the other with a mixture of water and papain. This enzyme is used to improve the gratings’ relief which was studied with a profilometer. For the development process with just water, it was found that when gratings were recorded using visible or UV light, the height profile inversely correlated to spatial frequencies. For short exposure times, the reliefs showed a sinusoidal profile. When visible light was used, the DCG areas where the Ronchi grating had transparent slits showed a flat relief and the areas where the Ronchi grating had opaque slits showed a round peak, with the peak being taller than the flat surface. In contrast, when UV light was used, the flat surfaces were taller than the peaks. The relief height increased up to seven times when papain was used.

Photo-embossing has been developed as a convenient and economical method for creating complex surface relief structures in polymer films. The pursuit for large aspect ratios of the photo-embossed structures has never stopped. Here, we demonstrate a simple strategy to obtain improved aspect ratios by adding a quick solvent developing step into the photo-embossing process. A good solvent for the monomer is used to remove unreacted monomers from the unexposed region, resulting in deepened valleys of the surface reliefs. In a polymer film as thin as 2.5 µm, the height of the surface reliefs can be increased by a factor of three to around 1.0 µm. This strategy is also shown to be compatible with other methods used to improve the aspect ratios of the photo-embossed structures. Lastly, we employ these surface relief structures in the fabrication of liquid crystal (LC) devices and investigate their performances for visible light regulation.

In this paper we synthesized and measured optical characteristics of an azopolymer based on the polymer N-epoxypropylcarbazole and chromophore 4 - (4-nytrophenylazo)-aniline. Regularities in surface microstructure formation under the influence of a Gaussian beam focused on the synthesized polymer film were shown. With the linearly polarized incident laser beam, the anisotropic formation of the surface microstructures was demonstrated. The dependence of the microstructure formation on the incident beam power density was studied. Also, we experimentally investigated the nonlinear optical effects emerging in the azopolymer structure exposed to a high-intensity laser beam. Nonlinear topographic effects arising during the formation of microstructures by means of linearly and elliptically polarized beams were described.

A new method of formation of relief-phase holographic structure on dichromated gelatin (DCG) layers has been proposed. The method is based on two types of alternative effects on gelatin: structuring by selective light tanning by coherent He–Cd laser radiation and destruction by short-wave UV radiation. A time-shortened water treatment of samples interrupted by an isopropanol bath was previously proposed to obtain highly effective holographic relief structures in the region of high spatial frequencies up to 1500 mm–1. In this paper, it has been proposed to abandon the water treatment of dichromated gelatin layers and replace it by heating the sample during its processing with short-wave UV radiation. In the course of experiments, a steady increase in the diffraction efficiency has been obtained regardless of the spatial frequency and dichromated gelatin layer thickness, which has been explained by the formation of a relief holographic structure because of the evaporation and shrinkage of gelatin areas degraded by UV radiation under the influence of high temperature. [ABSTRACT FROM AUTHOR]

The review systematizes the results of studying the early stages of climatic aging of polymer composite materials by the methods that are sensitive to destruction in the surface layer of samples. The surface relief height, the diffusion coefficient of moisture, and the glass transition temperature of epoxy binders are shown to be sensitive to the action of temperature, humidity, solar radiation and other environmental factors. [ABSTRACT FROM AUTHOR]

A model is proposed for the formation of surface relief in strip milling. The recommended procedure is to select the milling conditions on the basis of a regression equation expressing the final surface relief as a function of those conditions. Regulation of the milling conditions in terms of tool wear improves the mill life and productivity. [ABSTRACT FROM AUTHOR]

This work addresses the phenomenon of the development of a patterned surface relief on polymer films via different modes of environmental crazing. Commercial films of semicrystalline poly(tetrafluoroethylene) (PTFE) and amorphous glassy poly(ethylene terephthalate) (PET) were subjected to tensile drawing in the presence of physically active liquid environments (carbon tetrachloride or aliphatic alcohols). The structure parameters and wettability of the modified films were studied by AFM, SEM, profilometer measurements and contact angle measurements. Environmental intercrystallite crazing of PTFE is accompanied by the development of an unstable structure with a high free surface, which experiences marked strain recovery upon unloading. As a result of the relief formation, PTFE hydrophobicity is enhanced (the water contact angle increases by 25°). Classical environmental crazing of PET films is accompanied by the formation of an anisotropic surface relief which is an assembly of crazes oriented perpendicular to the direction of tensile drawing, thus leading to the phenomenon of anisotropic wetting. The proposed approach for structural surface modification makes it possible to use the advantages of surface instability and spontaneous self‐organization of the polymer towards the development of a unique surface microrelief. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Production costs and product quality in manufacturing depend directly on tool life in cold and hot machining of metals and alloys. The types of surface failure in tools are considered in the present work. The potential for increasing their wear resistance by electrospark coating deposition is noted. The dependence of the relative coating thickness on the relative limiting carrying capacity of the coating is determined for surface hardening of forged tools. The influence of the electrode composition on the resulting surface properties is analyzed. [ABSTRACT FROM AUTHOR]

The application of two types of alternative action on gelatin in the layers of dichromated gelatin (DCG) was considered: structuring with the use of selective light tanning by the radiation of a He–Cd laser ( nm) and destruction performed by exposure of layers to short-wave ultraviolet radiation ( nm). The crucial role of UV exposure of samples in generating high-frequency relief-phase gratings with diffraction efficiency higher than 50 on DCG layers thinner than 2 m is shown. It is noted that the application of traditional treatment methods of DCG layers leads to smoothened relief due to action of surface tension forces at high spatial frequencies. In addition, significant broadening of the domain of registered spatial frequencies (up to 1500 mm ) for recording relief holographic gratings is achieved by applying the modified technique of gelatin treatment based on reduced time of water procedures and by using the isopropanol baths for quick layer dehydration. [ABSTRACT FROM AUTHOR]

The effect of surface relief profiles of alkanoate-based bionanofilms to the monocyte-macrophages (MN-MPhs) from peripheral blood of patients with atherosclerosis was studied in vitro. Patients were subjected to coronary stenting. Cell morphology and phenotype (expression of CD antigens, levels of production of marker cytokines) in vitro were analyzed before and after the installation of stents. It was shown, that the mean square roughness (Rq) of the bionanofilms determined the variability of cell morphology, CD antigens spectraand activity of production interleukins-6 and -10. Also, it was revealed, that the "activity" of the surface topography of biopolymer substrates depends on the functional state of MNs, isolated in different time points: Before and after stenting the ratios of cell morphotypes and production of cytokines in MN-MPhs differed significantly. [ABSTRACT FROM AUTHOR]

Growth of the diffraction efficiency and recording velocity was found in the films of copolymers 4-((2- nitrophenyl) diazeniyl)phenylmethacrylate) with octylmethacrylate at room temperature holographic recording for copolymer with less softening temperature. Effect of strengthening of the diffraction efficiency was observed when charging surface of the films with recorded hologram in crown discharge.

Using scanning electron microscopy and roughness measurements we studied the relief appeared on the surface of TiC-free Ni 3 Al and Ni 3 Al-TiC composites (TiC content was 10 and 30 vol%) as a result of low-energy high-current electron beam irradiation (the surface energy density was in the interval of 8–18.0 J/cm2, the accelerating voltage was 30 kV, the pulse duration was 3.2 μs, the number of pulses was 10 and 30). Using the same materials differing in the content of non-metallic particles for investigation enabled clarification of the role of non-metallic inclusions in the relief formation. The effect of the particles size, surface energy density and number of pulses was also analyzed. Three types of dimples forming the relief were revealed. Each of the type appeared following to its own formation mechanism. The applicability of the models existing in literature to explain relief formation was discussed. [ABSTRACT FROM AUTHOR]

Abstract In-situ measurement by digital holographic microscopy (DHM) was employed to clarify the difference between the surface relief effects of Widmanstätten ferrite (WF) and bainitic ferrite (BF) associated with their transformations from austenite in a low-carbon steel. It was clarified that the evolution of the surface relief is totally different between WF and BF. Only in BF, the observed ratio of the relief height to the plate width converged instantly to the value predicted by the phenomenological theory of martensite crystallography (PTMC). The ratio gradually increased with increasing plate thickness and never reached the value predicted by PTMC in WF. Graphical abstract Unlabelled Image [ABSTRACT FROM AUTHOR]

The mechanism of the formation of a complicated relief first found on the recrystallized tungsten surface in studies performed by A.I. Belayeva and coauthors is described in this work. Its essence is the deformation of boundaries and near-boundary volumes of crystallites (grains) in the near-surface polycrystalline-metal layer upon cooling after high-temperature holding that is caused by the difference in the ultimate strength and thermal expansion coefficients of boundaries and bodies of grains. In the near-surface layer upon cooling of the metal, due to the difference in the size reduction of grain boundaries and grain bodies, cracks (grooves) arise at boundaries on whose banks identical ridges are formed. The bending of the boundary makes the profile of grooves asymmetric and creates rather shallow creases in front of ridges. The surface relief impairs the service properties of metals but its formation can be prevented, if articles become single-crystalline owing to recrystallization. [ABSTRACT FROM AUTHOR]

Abstract: Titanium alloys approved for clinical use in Russia are widely used in traumatology, maxillofacial surgery, and stomatology, mainly for manufacturing various endoprostheses and dental implants, i.e., structures to be introduced and installed into the bone and soft tissues of the human organism, capable of both biointegration and bioadaptation in the tissues of the human organism. In the field of medicinal material science, particularly, in designing structures for medicinal use based on titanium and its alloys and also various coatings on the surface of such structures, the modern methods and instruments developed for the electronic industry are being widely used. The methods designed for investigating materials and structures in electronics are employed in medicinal technology and particularly in the development of titanium implants. This makes it possible to develop the fundamentals for the technology of preparing the optimal microrelief on the surface of titanic endoprostheses intended for engrafting in soft tissues (i.e., fibrointegrable) and covered by bioactive coatings of titanium dioxide (TiO2) with the anatase structure obtained by atomic-layer deposition. The research is aimed at revealing the optimal surface treatment of such endoprostheses in order to achieve improved fibrointegration properties for using them in maxillofacial surgery. It is shown that the strong adhesion and fibrointegration between the titanium endoprosthesis and the connective tissue are achieved at the average surface roughness of (4-8) × 102 nm, the root-mean-square roughness of (5 × 102-1 × 103) nm, a profile height of (3-6) × 103 nm, and a thickness of the bioactive coatings of the order of magnitude of 10 nm. [ABSTRACT FROM AUTHOR]

The effect of surface relief profiles of alkanoate-based bionanofilms to the monocyte-macrophages (MN-MPhs) from peripheral blood of patients with atherosclerosis was studied in vitro. Patients were subjected to coronary stenting. Cell morphology and phenotype (expression of CD antigens, levels of production of marker cytokines) in vitro were analyzed before and after the installation of stents. It was shown, that the mean square roughness (Rq) of the bionanofilms determined the variability of cell morphology, CD antigens spectraand activity of production interleukins-6 and -10. Also, it was revealed, that the “activity” of the surface topography of biopolymer substrates depends on the functional state of MNs, isolated in different time points: Before and after stenting the ratios of cell morphotypes and production of cytokines in MN-MPhs differed significantly.

Ice flow can transfer variations in basal topography and basal slipperiness to the ice surface. Recent developments in this theory have made it possible to conduct numerical experiments to predict mesoscale surface topographical undulations and surface relief on an ice sheet-scale. Focussing here on the contemporary Greenland Ice Sheet (GrIS), we demonstrate that the theory can be used to predict the surface relief of the ice sheet from bed topography, ice thickness and basal slip ratio datasets. In certain regions of the GrIS our approach overestimates, while in others underestimates, the observed surface relief. The magnitude and spatial pattern of these mismatches correspond with the theory's limitations and known uncertainties in the bed topography and basal slip ratio datasets. Our prediction experiment establishes that the first-order control on GrIS surface relief is basal topography modulated by ice thickness, surface slope and basal slip ratio. Additional analyses show that the surface relief, which is controlled by the bed-to-surface transfer of basal topography, preconditions the large scale spatial structure of surface drainage, with other factors such as surface runoff modulating the actual drainage system through influencing the temporal evolution of meltwater features. It follows that the spatial structure of surface drainage depends strongly on the transfer of basal topography to the ice surface. These findings represent an important step toward investigating and understanding the net long-term (>102 years) effect of surface drainage on ice sheet mass balance and dynamics during deglaciation events.

Films of a nonphotoconducting copolymer of styrene with octyl methacrylate doped with azobenzene dyes have been used to create recording media for polarization holography. An increase in the concentration of the azo dye with electron-donor groups in the chromophore, in contrast to unsubstituted azobenzene, leads to photoconductivity and increased diffraction efficiency of the polarization holograms. The diffraction efficiency can also be increased by charging the films in a coronal discharge. Holographic media with such films can find use both for dynamic polarization holography and for the prolonged storage of holographic recordings similar to photothermoplastic recording media. [ABSTRACT FROM AUTHOR]

The unilateral thickening of γ lamellae during α to γ transformation was investigated by examinations of surface reliefs and atomic steps of γ lamellae. The results show that the rounded corners of terraces and the steps prefer to form mainly on one side of the γ lamella, and Shockley partial dislocations with same and with very random Burgers vectors construct the steps. It indicates γ lamellae grow in a mixture of two scenarios of Shockley partial dislocations. The differences of γ/α interface stability and element concentration on the two sides of γ lamella contribute to the unilateral thickening. [ABSTRACT FROM AUTHOR]

Under irradiation of amorphous As x Se 100−x films by band-gap light, it was observed that lateral mass transport of the film material change the direction of movement in the region where topological structural transition occurs (4 < x < 5 at.%.). It was detected that the rate of mass transport increases essentially with temperature and reaches the maximum near the glass-transition temperature, Tg. We propose a model based on the lateral photo-Dember effect that qualitatively describes the observed phenomenon. [ABSTRACT FROM AUTHOR]

Recording media for polarization holography based on the new copolymers of 2-hydroxyethylmethacrylate with azobenzene monomers have been created and their electrophysical and information properties have been investigated. The increase of the diffraction efficiency of holograms with acceptor substitutes in the structure of azobenzene chromophores is explained by the increase of the dipole moment of the azobenzene chromophores. It was found that at room temperature the velocity of the dark relaxation of holograms recorded with perpendicular and parallel orientations of the polarization of the recording beams is the same. A non-trivial result is a growth of the hologram relaxation velocity under the influence of the polarized light of one of the recording beam. This growth of the velocity is much greater in the case of perpendicular orientations of the polarization of the recording beams. [ABSTRACT FROM AUTHOR]