Microrelief Parameters Research Articles

Analysis of micro-relief of biofilm of yeast Candida albicans of basic plastics by the method of laser modulation interference microscopy.

The development of mycotic colonization of the base surface with further biodegradation of acrylic plastics is currently of undoubted interest. The oral cavity is a favorable ecological niche for colonization by fungi and their subsequent possible invasion into the epithelium of the oral mucosa. The method of modulation interference laser microscopy is of considerable interest to researchers in medicine in the context of obtaining the necessary information about the morphological characteristics of microbial cells and the microbiome community as a whole during the colonization of a certain ecological niche in the human body. Purpose of the study: to analyze the microrelief of the biofilm of yeast-like fungi of the species Candida albicans of base plastics of the hot type of polymerization using the method of laser modulation interference microscopy. An experimental study was carried out in order to study biofilms of yeast-like fungi of the genus Candida on samples of basic plastics, an image of a biofilm of yeast-like fungi of the species Candida albicans was obtained on the surface of a plastic of a hot type of polymerization (polymethyl methacrylate) in the visualization of the phase portrait, a description of its horizontal and vertical bioprofile. As a result of the research, the heterogeneous structure of the biofilm was determined, due to the different density and accumulation of cells along the surface, the characteristics of the surface were established in accordance with the roughness criteria. The microrelief parameters on a separately arbitrarily selected section line allow one to determine the characteristics of the biofilm in the required area and make it possible to judge the nature of its formation in a certain biological niche.

ПОСТРОЕНИЕ ЦИФРОВОГО ИЗОБРАЖЕНИЯ СТРУКТУРЫ ПОВЕРХНОСТИ ПО ПРОФИЛЛОГРАММЕ ДЛЯ ОПРЕДЕЛЕНИЯ ЕЁ ХАРАКТЕРИСТИК В СООТВЕТСТВИИ С ГОСТ Р ИСО 25178-2— 2014

The article discusses new requirements for the characteristics of microgeometry of the working surfaces of machine parts in accordance with GOST R ISO 25178-2— 2014. It is shown that in order to calculate such characteristics, it is necessary to have information about the three-dimensional distribution of the microrelief parameters, that is, to move from the profile parameters of microgeometry to the parameters of its structure. In this regard, the article considers the application of a software method for forming a surface structure based on profilograms obtained by simpler devices.

Influence of constructive and geometric parameters of the end cutters on the microprofile characteristics of casting surfaces

The object of research is the technological route of machining of an aluminum alloy casting. The research carried out is based on the basic principles of functionally oriented design of technological processes in the manufacture of products. The main hypothesis of the study is the need for a systematic approach to study the effect of cutting modes of a certain method of machining on the provision of quality parameters in the technological system (machine – device – tool – workpiece). In traditional automated systems for technological preparation of production, an object-oriented principle of designing technological processes is implemented, which provides for the step-by-step implementation of interrelated stages based on a prototyping algorithm without a functional analysis of the operational characteristics of the product. The processing of functional, mating surfaces, ensuring that the product performs its service purpose, must be implemented according to the principle of function-oriented design (FODT). A characteristic feature of FOT is the technological provision of effective operational characteristics of the product in compliance with the parameters of accuracy and quality of the surface layer of the product intended by the designer. The paper deals with the influence of the structural and geometric parameters of end mills manufactured by Sandvick (Sandviken, Sweden) on the formation of microrelief parameters of an aluminum alloy casting profile during machining on a numerically controlled vertical milling center (CNC) HAAS MINIMILL (USA). An atypical option for the FOT principle of the technological route of machining the surfaces of workpieces of machine-building products has been applied. Its feature is ignoring the requirements of the manufacturer of metal-cutting tools, which is an important element of the technological system (machine – tool – device – workpiece), regarding its use for a particular machine tool at a certain technological transition of machining. The performance criteria were the height and step characteristics of the microrelief of the profile of the surface layer of the workpiece being processed. The operating conditions of machine-building products have been determined, which make it possible to establish, in case of deviation from the manufacturer's recommendations at the stage of technological preparation of production, the rational elements of a certain technological system: a metal-cutting machine – a device – a metal-cutting tool – a workpiece and processing modes to ensure the necessary operational characteristics.

Оценка параметров текстуры прецизионных поверхностей с применением квазиоптимальных корреляционных алгоритмов

The authors considered a new method of texture analysis of machined precision surfaces based on using computer optics and the autocorrelation method of processing the images of micro-relief textures under the study. This method is based on a probabilistic comparative evaluation of the unknown texture of the micro-relief under the investigation with the available textures of reference micro-patterns, in which microrelief parameters are determined. The paper proposes an approach to identify the profile surface roughness of a gas turbine engine (GTE) blade after vibro-contact polishing according to the parameters of correlation surface texture. The authors studied the surface micro-geometry of the blade back and pressure side using the optoelectronic complex based on the calculation of the average amplitude of the variable component of an autocorrelation function resulting from computer processing of a surface video image. The application of the electrooptic method for evaluating the surface texture of compressor and turbine blades allows building the surface roughness fields and more deeply analyzing the technology of final processing of the GTE blade feather profile. The relevance and novelty of the study lie in the promising technique to evaluate the surface quality parameters using the electrooptic method. A special feature of this method is the measurement of surface area roughness, while the stylus methods measure the roughness of the surface profile. An important advantage of the proposed method is its application to measure the roughness parameters of a curved surface by a non-contact method, which is advanced since there are surfaces of parts that do not imply being scratched with a diamond needle.

A compact imaging hyperspectrometer

The paper describes the design of a compact hyperspectrometer equipped with a transmission phase diffraction grating, which is used as a dispersing element. The calculation of the microrelief parameters of the dispersing element is given. The spectral characteristics of the developed device are investigated. The possibility of determining the normalized vegetation index is demonstrated. The weight and dimensions of the compact imaging hyperspectrometer are given.

Measurement of Microrelief Parameters Based on the Correlation Method of Image Processing of the Surfaces Under Study

A method is proposed for measuring the parameters of surface microrelief of machine parts by optical-electronic and computer means. The method is based on calculating the parameters of a two-dimensional auto-correlation function constructed from a binary image of the microrelief under study. It is established that the most informative characteristic of the studied microrelief of surfaces of precision parts, which significantly differ from each other with a given roughness recognition probability, is the average amplitude of the variable component of the autocorrelation function. The results of determining the parameters of the studied surface microrelief using quasi-optimal correlation algorithms are presented.

Studying parameters and quality of thread by optical light field recorder

The work suggests a method to inspect the profile and micro-relief of thread surface using a light-field optoelectronic system based on a digital camera with a collection of microlenses. The authors have developed an optical scheme to record 3D images of the profile and micro-relief of the controlled thread surface. The system involves computer technologies of National Instruments Company (NI, USA) to elaborate the algorithms for determination of thread profile geometry and micro-relief parameters. The results demonstrate that the implementation of the algorithms of morphological image layer analysis derived from the light field file specifying the depth of field allows increasing multiple times the accuracy of thread profile determination using the profile height. The article was prepared according to the State task (the project’s number No 9.10520.2018/11.12)

Shape and Relief Evaluation Using the Light Field Camera

The paper considers an optical system for controlling the shape and micro-relief of products using a single-camera optoelectronic light field recorder. Based on National Instruments computer technologies, image processing algorithms and basic surface measurements have been developed. To accurately determine macro- and micro-relief parameters the authors propose algorithms for morphological analysis of two images obtained from a multi-focus light field file at a given depth of field. It is shown that the method of capturing the light field makes it possible to obtain the accuracy of surface relief by the height of its profile compared to other methods, while significantly reducing control requirements.

Characterization of oily mature skin by biophysical and skin imaging techniques.

The skin is a complex biological system and may suffer change according to the environmental factors, as higher temperatures can increase sebum excretion, presenting oiliness and acne. These alterations can persist during the aging and provoke more changes in aged skin. In this study we evaluated the mature oily skin characteristics using biophysical and skin imaging techniques. Sixty healthy female subjects, aged between 39 and 55years old were recruited and separated into 2 groups according to their skin type: normal/dry and oily skin. The skin was evaluated in terms of stratum corneum water content, transepidermal water loss (TEWL) sebum content, dermis thickness and echogenicity, skin microrelief, and pores content. The mature oily skin presented no significant differences when compared to the normal/dry skin on the stratum corneum water content and TEWL parameters. The sebum content was significantly higher on the oily skin group. The microrelief analysis showed an increase of skin roughness values in the oily skin and increase of scaliness in the normal/dry skin. The oily skin showed lower dermis echogenicity mainly in the frontal region and higher dermis thickness when compared to normal/dry skin. The mature oily skin showed different characteristics from normal/dry skin in terms of sebum content, microrelief parameters, and dermis thickness. This way, the characterization of mature oily skin in an objective way is very important to development of dermocosmetic products for more effective treatments focused specially on this type of skin.

Structure of the surface microrelief of a droplet evaporating from a rough substrate as a possible cause of contact angle hysteresis

Based on the refraction images of a droplet evaporating on a rough substrate, we simultaneously observed the dynamics of its surface microrelief, contact angle, and contact line deformations along the entire perimeter of the contact line. This has led us conclude that the microrelief structure is directly related to the phenomenon of contact angle hysteresis and the jump-like pattern of contact line deformation. We suggest a possible mechanism for the occurrence of contact angle hysteresis during droplet evaporation and derive the relations that specify the range of possible contact angles at known microrelief parameters.

Regular Microreliefs on Tool Cutting Wedges Surfaces and Electro-Physical and Chemical Methods of Their Production

The paper justifies the types of regular microreliefs with variable parameters on the replaceable cutting inserts (RCI) rake surfaces. The theoretical research of the RCI cutting with regular microreliefs and local cutting wedges are executed. The effect of the microrelief parameters on the cutting process (the cutting force, temperature and tool wear) is considered. The application of electrochemical, electrical discharge and laser machining for the production of regular microreliefs with variable geometrical parameters is justified. Some examples of cutting by various RCI with regular microreliefs on the cutting wedges rake and flank surfaces are presented.

Surface Quality Multicriteria Optimization of Flat Parts from 06Cr14Ni6Cu2MoVaTi-SH Steel While Grinding by Varigrain High Porosity CBN Wheels

The grinding of flat parts from 06Cr14Ni6Cu2MoVaTi-SH high-strength corrosion-resistant steel was made by the highly porous wheel (HPW) of CBN30 (B76, B107, B126, V151) 100 OVK27-KF40 (GOST R 53922-2010, GOST R 53923-2010). As input variables for fuzzy logic modeling in the Matlab the following description of the surface quality is chosen: the microrelief parameters (GOST 25142-82) - Ra1, Rmax1 in the cross-feed direction, Sm2 in the length feed direction, flatness deviation (GOST 24642-81) are introduced with the EFEmax, EFEa and EFEq; microhardness HV. Every parameter at the model input is presented with position measures (medians) and scattering measures (quartile latitude). The Matlab modeling has shown that the best quality of the part surfaces is provided with HPW CBN30 B151 during the multicriteria optimization.

THE FRICTION MECHANISM BETWEEN SURFACES WITH REGULAR MICRO GROOVES UNDER BOUNDARY LUBRICATION

The results of research related to the influence of partially regular microrelief parameters on the adhesion component of the friction factor under boundary lubrication are presented. It has been shown that micro grooves are effective under boundary friction on precision surfaces with low roughness when lack of film and probability of seizure appear. The deformation component of the friction force of surfaces with micro grooves has been studied. The time of micro running-in was the key factor while assessing the dependence of the deformation component on friction when taking into account the depth of micro grooves and their relative area. The research was conducted using a tribometer according to the friction model entitled “shaft & flexible steel tape”.

Using objective criteria to evaluate cosmetic effects of platelet rich plasma

Autologous platelet rich plasma (PRP) plays an important role in soft tissue healing. The purpose of this study was to evaluate the efficacy of this facial skin treatment through objective parameters. Biometric parameters, including anisotropy, transepidermal water loss (TEWL), micro-relief, and hydration were used to determine the relative success of the treatment. The study, which included 37 female patients, demonstrated an average of 24% improvement in the anisotropy coefficient after the third week. The TEWL and micro-relief parameters also improved significantly (P < 0.05 in all parameters tested). In addition to these results, this study suggests that certain measured values may be used to predict the success of the aesthetic use of PRP.

Downscaling land surface temperature for urban heat island diurnal cycle analysis

Urban heat island (UHI) is a phenomenon of high spatial and temporal variabilities. It can develop during night or daytime. UHI monitoring is possible through thermal satellite remote sensing of land surface temperature (LST). LST over large areas (size of a city) can be measured at high temporal resolution merely from instruments on-board geostationary satellites. These can cover the diurnal cycle as they provide data even every 5 min (SEVIRI rapid scanning). Sensors on-board the geostationary satellites have, however, poor spatial resolution. Using high spatial resolution is in many regions most important because LST is a spatially inhomogeneous parameter especially in urban areas. UHI characteristics are correlated with the land cover and micro-relief parameters. These are often available in a higher spatial resolution (e.g. NDVI and EVI). Thus, we employed them to enhance the spatial resolution of the SEVIRI LST over central Europe – using moving window analysis – to 1000 m spatial resolution and temporal resolution of 15 min. For each SEVIRI pixel a multiple regression was run on the low resolution data. Regression equation was then used on the high resolution data in order to estimate LST of high spatial and temporal resolutions. The validation over urban areas showed that the downscaled SEVIRI LST is comparable with the MODIS LST with an average root mean square error of 2.5 K. The obtained results make possible to analyse the diurnal cycle of UHI.

Efficacy of anti-wrinkle products in skin surface appearance: a comparative study using non-invasive methods

Age has a huge influence on skin roughness; with increasing age, the number of collagen and elastine fibers is reduced and elasticity decreases significantly. Pharmaceutical and cosmetics, environmental factors and lifestyle have an important effect on skin. In this study, the efficacy of 12 commercial anti-wrinkle products was evaluated using a direct non-invasive method to measure the skin surface morphology. Four clinical parameters surface evaluation of the living skin (SELS) (Ser, Sesc, Sesm, and Sew) were evaluate using Visioscan(®) VC98. Two hundred and forty-eight healthy female volunteers, aged between 30 and 70 years, were chosen for this study. The duration of treatment was 28 days. Skin microrelief parameters were evaluated using the Visioscan(®) VC98 - SELS 2000 from Courage+Khazaka. Measurements were made in the crow's feet area and the differences were evaluated for statistical significance. Significant differences were found for some of the SELS parameters. According to the results obtained for SELS Sew, products that showed to be more effective against aging were V, M, N, T, P, R and L. We think this methodology may be considered very useful for the direct study of the skin surface and may be suitable as a routine method in wrinkle evaluation.

Bioengineering and subjective approaches to the clinical evaluation of dry skin

Dry skin (also known as xerosis) is a cutaneous reaction pattern indicative of abnormal desquamation, which has not only cosmetic considerations, but can also lead to the penetration of irritants and allergens through the stratum corneum (SC). Over the last few decades, our understanding of the structure, composition, formation and function of the SC has advanced tremendously; however, despite these advancements, the occurrence of dry skin remains prevalent in the adult population. The clinical evaluation of dry skin is therefore of significant importance to the cosmetic industry not only for understanding the condition but also for measuring the effects of treatment. Traditionally, dry skin has been evaluated by visual inspection, however, recently a variety of bioengineering techniques have emerged enabling the investigator to objectively assess the extent of xerotic conditions. The most frequently employed methods for the evaluation of dry skin are discussed in this review, including regression testing, squametry, measurement of transepidermal water loss, epidermal hydration, profilometry, confocal Raman spectroscopy, optical coherence tomography, in vivo confocal microscopy and magnetic resonance imaging.

Off-the-shelf laser scanning and close-range digital photogrammetry for measuring agricultural soils microrelief

Small-scale roughness on bare agricultural soils determines very important properties such as infiltration, runoff or soil erosion. In this work, a method based on photogrammetric tools has been developed for the generation of automatic digital elevation models (DEMs) in agricultural soils, and is compared with a method based on very accurate off-the-shelf three-dimensional (3D) laser scanners. High resolution and accurate DEMs are generated by both of these non-contact techniques on two agricultural field plots of about 0.2 m2: (i) untilled and smooth soil, and (ii) very cloddy tilled surface. Furthermore, classical microrelief parameters such as Random Roughness and Maximum Depressional Storage are computed from grid DEMs obtained by laser scanning and close-range photogrammetry. Both techniques are compared on agricultural soils in terms of data acquisition and analysis performance, resolution, accuracy, and capability of representing microrelief and for computing microrelief parameters. Both the techniques tested have proved able to generate, under ideal conditions, DEMs with high accuracy (standard deviations of the residuals were 0.121 mm and 0.467 mm for laser and photogrammetry, respectively) and resolution (about 0.4 mm for laser scanning and 1 mm for the photogrammetric method). It is also worth noting that soil DEMs can be generated by both methods in less than 2 h, using devices in field assays that are not too expensive. Laser scanning produces a far more detailed surface allowing it to reproduce smaller aggregates than the photogrammetric method. On the other hand, data acquisition is faster with digital photogrammetry. The worse performance with either method happens when they are used on a rougher type of soil. Regarding the proposed non-contact methodologies, field soil microrelief can be attained in a fast, accurate, and economic way. In addition, the microrelief parameters computed from agricultural soil grid DEMs by laser scanning and photogrammetry show quite similar values.

Effects of physical and chemical treatments upon biophysical properties and micro-relief of human skin

The aim of the present study was to determine the attendant effects of physical (tape-stripping) and chemical (three commercial hydrating formulations) treatments upon biophysical and micro-relief properties of human skin. In the first set of experiment, the effects of tape-stripping onto human stratum corneum (SC) biophysical and micro-relief properties were assessed in nine volunteers. Transepidermal water loss (TEWL), skin hydration and micro-relief parameters (including total length of the lines in mm per mm(2); total surface in %; roughness of the skin measured in gray level (Ra); maximum profile valley (Rv) depth; maximum profile peak height (Rp); maximum height (Rt), peak density (Pc) and coefficient of anisotropy) were determined by using SkinEvidence Pro after subsequent tape-stripping of SC. The relevance of roughness determination as gray level by SkinEvidence Pro was confirmed by using surface roughness standards. In the second set of experiment, the effectiveness of three commercial hydrating formulations onto human SC biophysical parameters and micro-relief properties were assessed in six volunteers. TEWL, hydration and micro-relief parameters were assessed onto pre-treated acetone skin and then treated by three commercial hydrating formulations after 2, 4 and 6 h skin exposure. A linear relation between hydration and cutaneous parameters (total length of the lines, Ra and Rp) as function of SC removed was shown. Skin barrier properties evaluated by TEWL measurements, were not modified by topical formulations. However, skin treated by topical formulations showed slightly higher hydration than the one determined in control group, while micro-relief parameters were not modified. In this study was showed that biophysical and micro-relief parameters were closely related in tape-stripping experiment. Efficiency of topical formulations was suggested upon skin hydration but not onto skin micro-relief and barrier function recovering. From both experiments, it appears that different mechanisms relating to skin hydration and potential modification of cutaneous micro-relief were suggested.

Objective Evaluation of the Placebo Effect in Cosmetic Treatments. A Randomized Controlled Study

A product's packaging and claimed efficacy may stimulate pleasant emotions during the use of cosmetics, thus enhancing their perceived benefits. The aim of this study was to evaluate if smart packaging and strongly claimed efficacy attributes can influence the objectively measured efficacy, allowing a true placebo effect to be associated with a given cosmetic treatment. A marketed anti‐aging gluconolactone‐based formulation was selected for the study and packaged both in a fancy sophisticated jar and in an unbranded plain container. Thirty‐six female volunteers (age range: 30‐‐55 years) with facial photoageing were selected for the study and randomly assigned to the fancy or plain packaged product. Pre‐agreed messages aimed at extolling the product's cosmetic effects accompanied delivery of the fancy‐packaged product to panellists. The given product was applied to the face twice a day for 8 weeks. Instrumental measurements of the skin colour (a* and L* parameter), skin capacitance, skin tensile properties (R0, R2, R6), skin thickness and skin microrelief parameters (Ra and Rz) were taken at baseline and after 4 and 8 weeks of use. Clinical and subjective evaluations were also carried out at each control visit. Moreover, the amount of cream consumed during usage was calculated by weighing the given jars at each visit. Statistical analysis of the data obtained showed a significant improvement in all instrumental parameters for both groups (‘fancy’ and ‘plain’ packaging), although no significant differences were detected between the two groups at any time. The improvement was higher in the ‘plain’ group for most instrumental parameters except for micro‐relief parameters where the outcome was better in the ‘fancy’ group. Promotion of facial muscle relaxation deriving from the application of the fancy‐packaged cream could be a possible explanation for this finding. Also the product's efficacy and sensory properties were perceived with a higher positive impact in the fancy group. The better performance of the plain packaging group could be related to daily application of the ‘proper’ amount of cream. In fact, this group consumed a larger amount of cream than the ‘fancy’ group. These results show that a true placebo effect cannot be induced by packaging characteristics, although they can slightly influence the degree of the expected skin benefits in different ways. Moreover, proper daily dosage of the product appears to be a key factor in improving the biophysical skin properties related to anti‐ageing and restoring effects.Paper presented at the IFSCC Conference 2005, Florence, Italy.