Polished Surface Research Articles

Symmetrical dual-D and dual-core single-mode fiber surface plasmon resonance liquid sensor

A symmetrical dual-D and dual-core single-mode fiber surface plasmon resonance (SPR) liquid sensor is designed for biological detection. The dual-core design optimizes the transmission path, improves the momentum matching between free electrons and photons, and facilitates bidirectional coupling, consequently amplifying the SPR effect and enabling sensitive monitoring of the refractive index changes of biological solutions. In this structure, a gold wire is placed in the middle of the polished surface of the double-D-shaped single-mode fiber (SMF) to produce high-quality free electrons and promote the mode-coupling excitation of the SPR effect. The characteristics of the sensor are analyzed by the finite element method, and the important structural parameters are optimized systematically. The sensor can be operated in the near-infrared region for a refractive index (RI) range of 1.31–1.40 with a maximum wavelength sensitivity (WS) of 21,000 nm/RIU, amplitude sensitivity of 586.62RIU−1, as well as resolution of 4.76×10−6RIU. Small changes in the refractive index can be detected by the sensor and it can be produced easily by conventional manufacturing techniques. The sensor thus has wide application prospects in biomedical and chemical analysis and related applications.

Effect of conventional cigarette smoking and recent heated tobacco products on CAD/CAM restorative materials

ObjectiveTo determine the effects of conventional cigarette smoking (CS) and recent heated tobacco products (HTPs) on the surface roughness and color stability of different indirect restorative materials.Materials and methodsOne hundred disc-shaped samples were constructed of three different restorative CAD/CAM materials: lithium disilicate glass–ceramic (IPS e.max CAD; Ivoclar Vivadent, Liechtenstein), zirconia (BruxZir® Zirconia, Glidewell, USA) and polyetheretherketone (BioHPP® bredent GmbH, Germany). Of the IPS e.max CAD and the Bruxzir samples, 20 samples were glazed, and 20 samples were polished, while the BioHPP samples were all polished according to the manufacturer’s instructions.Fifty samples were subjected to conventional cigarette smoking (LM, Philip Morris International Inc., Egypt) (Groups: IPS e.max CAD_Glazed exposed to CS (LD_G_Cig), IPS e.max CAD_Polished exposed to CS (LD_P_Cig), Bruxzir_Glazed exposed to CS (Zr_G_Cig), Bruxzir _Polished exposed to CS (Zr_P_Cig) and BioHPP exposed to CS (PEEK_Cig) and fifty samples were exposed to heated tobacco product smoking (Heets, Russet selection, Philip Morris International Inc., Italy) (Groups: IPS e.max CAD_Glazed exposed to HTP (LD_G_HTP), IPS e.max CAD_Polished exposed to HTP (LD_P_HTP), Bruxzir_Glazed exposed to HTP (Zr_G_HTP), Bruxzir CAD_Polished exposed to HTP (Zr_P_HTP) and BioHPP exposed to HTP (PEEK_HTP).. Six hundred cigarettes/heets representing 30 days of medium smoking behavior (20 cigarettes/day) were used. Before and after exposure to smoke, the surface roughness of all the samples was measured using JITAI8101 surface roughness tester (Beijing Jitai Tech Detection Device Co., Ltd, China, and the color parameters were assessed using VITA Easyshade Advance 4.01 (VITA shade, VITA made, VITA). The data were analyzed using One-way ANOVA, paired sample t-test and independent sample t-test. The significance level was set at α < 0.05.The surface topography was evaluated by scanning electron microscopy (SEM) and analyzed using energy-dispersive X-ray (EDX) spectroscopy to determine changes in the surface chemical composition.ResultsBoth types of smoking caused significant increases in the surface roughness of all the samples. There was a significant difference in color change between CS and HTP for all materials with different surface finish (P < 0.01) and zirconia had the greatest effect on color change (P < 0.001). In contrast, polyetheretherketone (PEEK) “BioHPP” had the least effect (P < 0.001).ConclusionExposure to different types of smoking induce changes in the surface topography and color of different esthetic restorative materials. Compared with HTP, conventional cigarette smoke has a greater effect on the surface roughness and color stability of esthetic restorative materials. The glazed surfaces showed less change in surface topography than did the polished surfaces. Zirconia showed better color stability when compared to polyetheretherketone (PEEK).

Biological and Physicochemical Analysis of Sr-Doped Hydroxyapatite/Chitosan Composite Layers.

In this work results are presented on the evaluation of HAp, HApSr, HAp_CS, and HApSr_CS layers deposited on Ti substrates regarding L929 cell viability and cytotoxicity as well as antimicrobial activity against Staphylococcus aureus, in connection with their physicochemical properties. The HAp and HApSr layers generated by radio-frequency magnetron sputtering technique were further covered with chitosan by a matrix-assisted pulsed laser evaporation technique. During the plasma depositions, the Ti substrates were heated externally by a home-made oven above 100 °C. The HApSr_CS layers generated on the unpolished Ti substrates at 100 °C and 400 °C showed the highest biocompatibility properties and antimicrobial activity against Staphylococcus aureus. The morphology of the layer surfaces, revealed by scanning electron microscopy, is dependent on substrate temperature and substrate surface roughness. The optically polished surfaces of Ti substrates revealed grain-like and microchannel structure morphologies of the layers deposited at 25 °C substrate temperature and 400 °C, respectively. Chitosan has no major influence on HAp and HApSr layer surface morphologies. X-ray photoelectron spectroscopy indicated the presence of Ca 2p3/2 peak characteristic of the HAp structure even in the case of the HApSr_CS samples generated at a 400 °C substrate temperature. Fourier transform infrared spectroscopy investigations showed shifts in the wavenumber positions of the P-O absorption bands as a function of Sr or chitosan presence in the HAp layers generated at 25, 100, and 400 °C substrate temperatures.

From Dataset Creation to Defect Detection: A Proposed Procedure for a Custom CNN Approach for Polishing Applications on Low-Performance PCs

This study focuses on training a custom, small Convolutional Neural Network (CNN) using a limited dataset through data augmentation that is aimed at developing weights for subsequent fine-tuning on specific defects, namely improperly polished aluminum surfaces. The objective is to adapt the network for use in computationally restricted environments. The methodology involves using two computers—a low-performance PC for network creation and initial testing and a more powerful PC for network training using the Darknet framework—after which the network is transferred back to the initial low-performance PC. The results demonstrate that the custom lightweight network suited for a low-performance PC effectively performs object detection under the described conditions. These findings suggest that using tailored lightweight networks for recognizing specific types of defects is feasible and warrants further investigation to enhance the industrial defect detection processes in limited computational settings. This approach highlights the potential for deploying AI-driven quality control in environments with constrained hardware capabilities.

A scalable method for fabricating monolithic perovskite/silicon tandem solar cells based on low-cost industrial silicon bottom cells

Tandem solar cells composed of perovskite and silicon (PVSK/Si TSCs) exhibit significant potential for improving the power conversion efficiency (PCE) and reducing the levelized cost of electricity. Currently, most tandem cells demonstrating high efficiencies utilize costly float zone (FZ) silicon wafers, which pose limitations for large-scale production due to their high expense. This study presents a scalable approach for manufacturing perovskite/silicon tandem solar cells using industrial silicon bottom cells. We employ a double-layer intrinsic amorphous silicon passivation layer to enhance the carrier lifetime of the bottom silicon cell. Additionally, we introduce a novel indium oxide doped with transition metals (IMO) transparent electrode to enhance near-infrared (NIR) light absorption. To achieve silicon bottom cells with a polished front surface, we utilize a cost-effective and time-saving saw damage etching process. The perovskite absorber is then deposited on the polished surface using slot-die coating. Furthermore, we coat the perovskite absorber with a mixed solution of FAI and mF-PEAI via slot-die coating to eliminate excess PbI2 on the surface and passivate surface defects. Through the integration of top and bottom sub-cells, we obtained a PCE exceeding 24.22 % from a 5 cm × 5 cm TSCs device (with an aperture area of 3.8 cm × 3.8 cm) and a PCE of 28.68 % from a 2.5 cm × 2.5 cm TSCs device (with an aperture area of 1 cm × 1 cm).

Machining performance and material removal mechanism of sapphire with novel polishing slurry

Enhancing the interfacial reactivity of polishing slurry is crucial for improving the polishing efficiency and surface quality of sapphire wafers. In this study, a novel green polishing slurry was developed, comprising aminomethyl propanol, xylitol, highly active silica, and deionized water. The processing quality and removal mechanism of this novel green polishing slurry on semi-solid flexible polishing were investigated to achieve ultra-precision, high-efficiency, and environmentally friendly polishing of sapphire wafers. Experimental results demonstrated that the novel green polishing slurry reduced surface roughness by 12.5% and increased the material removal rate by 71.3% compared with traditional polishing slurry. Various analytical techniques, including wear debris analysis, molecular simulation, infrared detection, electrochemical testing, and physical phase detection, were utilized to explore the material removal mechanism. The findings indicated that aminomethyl propanol promotes chemical reactions between the green polishing slurry and sapphire wafers, leading to the conversion of the intermediate product Al(OH)3 to Al(OH)4-. In addition, the complexation reaction between xylitol and Al(OH)4- ions during polishing was found to accelerate the removal of surface materials from sapphire wafers, resulting in improved polishing efficiency and surface quality.

The impact of PAC-loaded polymer membrane thickness on chloroform removal and comparison of solvent and thermal membrane regeneration methods.

Powdered activated carbon (PAC) has better adsorption performance than granular activated carbon (GAC) and is widely used in water purification. In most cases, PAC is dosed into water directly, then precipitated as sludge, and landfilled. In this study, PAC was mixed with a polymer and dissolved in dimethylformamide (DMF) solvent to form a PAC-loaded membrane, which was then tested for chloroform removal. The chloroform adsorption capacity of the PAC membrane increased with increasing membrane thickness because of higher carbon loading. However, regardless of membrane thickness, the flux of the PAC membranes was similar since flux resistance predominantly occurred at the top dense polymer surface. This dense surface can be removed by sandpaper polishing, where the adsorption capacity of the polished PAC membranes was 20% higher than the unpolished membranes because of more even distribution of feed water on the polished surface. Removal of the dense surface via polishing increased the flux by 97% to 130%, exceeding the flux of typical household carbon block filters. Using DMF to regenerate the membrane recovered 48% to 66% of the initial adsorption capacity. Thermal regeneration of the exhausted PAC membrane at 250°C was more effective than DMF regeneration (both in terms of cost and performance), with 83% to 94% PAC membrane regeneration efficiency over four regeneration recycles. After four thermal regeneration cycles, flux increased by 300% and the membrane became brittle because of thermal aging of the polymer, indicating that a total of 6h of regeneration time (equivalent to three cycles in this study) was the limit for effective PAC membrane performance. PRACTITIONER POINTS: Powdered activated carbon was immobilized on a membrane to remove chloroform from water. Thicker membranes increased adsorption capacity but did not impact flux. Flux and capacity increased using polishing to remove the dense polymer surface and more evenly distribute flow across the membrane. Thermal regeneration of the membrane at 250°C was effective for up to three cycles and outperformed solvent-based regeneration. PAC-loaded filters are relevant for applications such as household carbon block filtration.

Evaluation of Surface Roughness of Acrylic Denture Bases Polished Using Algishine, a Novel Polishing Material: An In Vitro Study.

Introduction Surface roughness (Ra) significantly impacts the aesthetic and functional qualities of dental prosthetics. Traditional polishing involves pumice, a material routinely used in dental practice. This study introduces Algishine as a potential cost-effective eco-friendly alternative. Materials and methods A 3D design software (Geomagic) created a Standard Tesselation Language (STL) file of 10 mm x 10 mm x 2 mm. 30 STL file outputs were generated. The output was milled in wax. This was then flasked and processed. 30 acrylic resin specimens were fabricated and divided into two groups. Group A was polished using traditional pumice, and Group B was polished using Algishine. The Ra of each sample was measured using surface profilometry, with three readings per sample averaged for each group. Results Kruskal-Wallis test was performed to compare the two groups with the pre-testing samples, which showed p<0.05; indicating that there was a significant difference between the two groups. The average Ra value for unpolished acrylic was 7.105, while the specimens polished with pumice showed an Ra value of 2.218; specimens polished with novel materialAlgishine showed an Ra value of 1.743. This illustrates that Algishine achieves surface smoothness significantly superior to commonly used polishing agent andpumice. Discussion The results of our study demonstrate that Algishine, a novel polishing material derived from recycled alginate, effectively reduces the Ra of acrylic resin. This finding has significant implications, both clinically and environmentally. The primary clinical benefit of a smoother acrylic resin surface is the enhanced aesthetic appearance and increased patient comfort. A polished surface reduces plaque accumulation, thereby decreasing the risk of oral infections and improving the longevity of the dental prosthesis. The results show that Algishine achieves surface smoothness comparable to or better than pumice indicating that it can maintain, if not enhance, these clinical outcomes. Dental professionals can confidently use Algishine, knowing it meets the high standards required for patient care. Conclusion Algishine effectively reduces the Ra of acrylic resin, suggesting it is a viable, eco-friendly alternative to traditional pumice for dental polishing procedures. This indicates potential benefits in maintaining clinical outcomes while promoting environmental sustainability.

An evaluation of antagonist enamel wear opposing full-coverage zirconia crowns versus other ceramics full-coverage crowns and natural enamel - An umbrella review.

The aim of this umbrella review was to systematically review the systematic reviews on antagonist enamel wear opposing zirconia crowns compared to other ceramics and natural enamel. This was an umbrella review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. An electronic search of PubMed, Cochrane Central, EBSCOhost, and Google Scholar search engines for articles published from January 1, 2013, to January 1, 2023, was conducted using keywords "enamel wear," "zirconia," "feldspathic," "dental ceramics," and "Y-TZP" to identify systematic reviews on antagonist enamel wear opposing zirconia crowns compared to other ceramics and natural enamel. Qualitative analysis. A total of 86 articles were obtained through electronic search, of which four articles were selected after abstract screening that met the inclusion criteria for evaluating antagonist enamel wear. As compared to feldspathic groups, zirconia had substantially less antagonist wear, while surface polishing exhibited less enamel wear than glazing. Because of the heterogeneity in study design, measurement methods, and outcome variables, a meta-analysis was not possible. Over time, the opposing enamel wear caused by polished monolithic zirconia will be either equal to or less than that of natural enamel wear. Polished monolithic zirconia also maintains lower values of enamel wear compared to metal ceramics, feldspathic porcelains, and lithium disilicate.

The Effects of Air Abrasive Polishing on the Release of Iron Ions from Various Orthodontic Arch Wires (Stainless Steel and Nickel Titanium)

Orthodontic treatment with has been increasingly demanded. However, when using fixed appliances for orthodontic treatment, oral hygiene is compromised, and there is a higher chance of developing dental stains, plaque-related diseases, and corrosion-related problems. Air abrasive polishing had a superior effect over the conventional method in removing dental deposits, however, its effect on corrosion process was not investigated thoroughly in details. This study designed to assess the effects of air polishing onion release and surface micromorphology of stainless steel and Nickel titanium arch wires. A total of 288 ( stainless-steel , coated stainless steel , Nickel titanium and coated Nickel titanium rectangular arch wires ) of one brand ( The Ultimate Wire) ™ From IOS (International Orthodontic Services, Stafford, USA), (0.016 * 0.022 ) were subjected to varying air abrasion polishing periods (5, 10, and 20 seconds), after which they were immersed in artificial saliva with a pH of 6.75 and incubated at 37°C for 28 days. Ion release was measured using an atomic absorption spectrophotometer at 7 days, 14 days, and 28 days. The cumulative effect was then calculated. After polishing the chosen sample, corrosion and surface changes were evaluated using a scanning electron microscope (SEM). The significant difference between the analysed groups was found using an analysis of variance (ANOVA) and the LSD test, with a significance level of p 0.05. The results revealed that all types of arch wire showed a significant amount of release in the tested ions and the amounts of nickel and iron ions released was higher than chromium ion. Additionally, the longer the polishing time the higher the number of ions release that’s yields the level of significance, air abrasion polishing increased surface roughness and surface pits and crevices.It may be concluded that the air polishing method enhanced the amount of ion release to a subtoxic level and could be employed in adult patients with a lengthy time between visits.This study was performed to:1. Evaluate the effect of calcium carbonate airborne particles abrasion with different polishing times 5, 10 and 20 seconds on (Fe) ions release from orthodontic arch wires. 2. Assess the surface micromorphology of orthodontic arch wires after air polishing procedure.

Surface microstructuring of hot-rolled carbon structural steels under complex exposure to laser radiation

The purpose of the work was to study the effect of laser microstructuring modes of the cutting edge on changes in the structure and mechanical properties of the surface layer of parts made of hot-rolled structural carbon steels grades 20, 35, 45. Methods. Structural carbon steels of grades 20, 35, 45 were selected as objects of research. To study the effect of laser modification on changing the structure and mechanical properties of machine parts using laser cutting, special samples were made in the form of square plates (35×35 mm) with a thickness of 2 mm (St20 and St45) and 4 mm (St35). After laser cutting according to the modes, one of the sides of the sample was subjected to mechanical grinding in order to remove a layer with a modified structure of the material obtained during laser cutting. Next, laser microstructuring of the sample surfaces was performed using a continuous fiber laser. Metallographic and durometric studies were carried out to study the effect of laser microstructuring on changes in the structure and properties of the surface layer. Results. The regularities of the structure of the zone of laser action of structural carbon steels after laser microstructuring have been revealed, which consists of two layers: a non-etching (slightly etching) white layer, which is a finely dispersed martensite of a needle structure and immediately following it a zone of thermal influence, which, depending on the carbon content in the steel, has a different structure: ferrite-pearlite, martensitic, troostomartensitic, martensiticpearlitic. It has been established that laser microstructuring of a pre-polished surface in some cases leads to an increase in the values of microhardness and the length of the laser exposure zone, which may be associated with an increase in the absorption capacity of the material of the polished surface and, accordingly, a decrease in its reflectivity. Conclusion. The results obtained can be used in the creation of resource-saving material processing processes.

Comparative Analysis of Car Surface Polishing Methods

Comparative Analysis of Car Surface Polishing Methods

Spectroscopic Identification of Mineral Pigments in White Decorated Prehistoric Pottery from Bulgaria

In the prehistoric period on the Balkan Peninsula, the technology of white decoration underwent a drastic change. At the beginning of the Neolithic white pigment was applied as paint on a polished surface. At the end of the epoch, white paste was inlaid in incised channels on the surfaces of vessels. This study is focused on the identification of mineral pigments used for white decoration of Neolithic and Chalcolithic pottery from the territory of Bulgaria. The aim of this work is to answer the question of whether the composition of the white pigment varies according to the technique of decoration (paint and inlay). A set of 41 pottery fragments from 11 archaeological sites on the territory of Bulgaria was analyzed utilizing two spectroscopic techniques: laser-induced breakdown spectroscopy (LIBS) and Fourier-transform infrared spectroscopy (FTIR). Additionally, the experimental data from the LIBS were statistically treated with the multivariate technique, principal component analysis (PCA). The results from the spectral analysis indicated that the main constituent in the white decorated sherds is calcite in various combinations with carrier materials like quartz, feldspars, and metal oxides. The statistical analysis revealed that the primal constituent in the inlaid sherds is calcite while in the painted part, the carrier material is dominant. In some particular sherds, gypsum, hydroxylapatite, kaolinite, and aragonite were also detected.

High-Throughput Microstructural Characterization and Process Correlation Using Automated Electron Backscatter Diffraction

The need to optimize the processing conditions of additively manufactured (AM) metals and alloys has driven advances in throughput capabilities for material property measurements such as tensile strength or hardness. High-throughput (HT) characterization of AM metal microstructure has fallen significantly behind the pace of property measurements due to intrinsic bottlenecks associated with the artisan and labor-intensive preparation methods required to produce highly polished surfaces. This inequality in data throughput has led to a reliance on heuristics to connect process to structure or structure to properties for AM structural materials. In this study, we show a transformative approach to achieve laser powder bed fusion (LPBF) printing, HT preparation using dry electropolishing and HT electron backscatter diffraction (EBSD). This approach was used to construct a library of > 600 experimental EBSD sample sets spanning a diverse range of LPBF process conditions for AM Kovar. This vast library is far more expansive in parameter space than most state-of-the-art studies, yet it required only approximately 10 labor hours to acquire. Build geometries, surface preparation methods, and microscopy details, as well as the entire library of >600 EBSD data sets over the two sample design versions, have been shared with intent for the materials community to leverage the data and further advance the approach. Using this library, we investigated process–structure relationships and uncovered an unexpected, strong dependence of microstructure on location within the build, when varied, using otherwise identical laser parameters.

Influence of the as-built surface and a T6 heat treatment on the fatigue behavior of additively manufactured AlSi10Mg

As the fatigue strength of materials manufactured via lase-based powder bed fusion (PBF-LB) is highly influenced by process-induced defects and the “as-built” surface, in this work fatigue tests at specimens made of AlSi10Mg with “as-built” and polished surface condition were conducted. In this context also the defect tolerance of the material, and hence its ability to counteract process-induced notch effects, was analyzed. For this, specimens in a not heat-treated and an artificially aged (T6) condition were tested. For the not heat-treated specimens, a high reduction of the fatigue strength due to the “as-built” surface is observed, while the heat-treated specimens exhibit no influence of the surface condition. Using the √area approach, it is demonstrated that the smaller fatigue strength due to “as-built” surface observed for the not heat-treated condition results from process-related residual tensile stresses, which are removed by T6 heat treatment and polishing, respectively. Moreover, the results show that the “as-built” surface leads to similar stress concentrations than defects in the specimen volume, and thus, polishing had no influence on the fatigue performance after heat treatment. In addition to these findings, an increased fatigue strength after T6 heat treatment was observed, which is caused by an increased defect tolerance.

FLAW DEFECTION ANALYSE OF THE SURFACE OF ACRYLIC BASE PLASTICS

This study examines the possibility of assessing the quality of removable orthopedic devices by measuring the smoothness of their surfaces and detecting microscopic defects. The methodology involves comparing standard samples of the base material with samples that have been intentionally defective, using defectoscopy techniques for analysis. Initially, twenty samples of basic acrylic plastic were selected: half of them were perfectly machined to dental standards and the other half were intentionally scratched with sandpaper. These samples were then examined by macrophotography and analyzed using Image J software for quantitative image measurement. This analysis provided numerical data on the polished surface's quality, focusing on metrics such as the total number of defects, and the average size and perimeter of these defects. Statistical evaluation through the JUSP program compared the two sets of samples, highlighting significant differences between them. From the most prominent data points provided by Image J, conclusions were made regarding the surface quality of the acrylic plastic and how it is affected by specific mechanical imperfections. This method of using optical flaw detection offers a new way to clinically evaluate the quality of detachable orthopedic devices (like base plastic) in terms of their susceptibility to bacterial buildup, which could lead to inflammation in the prosthetic bed's mucosal lining. The use of flaw detection analysis allows for a general assessment of the quality of the material surface polishing, detection of surface defects in its structure that may occur during the production stage or during operation, thereby preventing areas of biofilm accumulation. Light-optical flaw detection in the experiment proved its effectiveness and makes us pay attention to the prospects of its improvement and wider implementation in clinical practice.

Research on the performance of foamed concrete based on superhydrophobic bulk modification

Foamed concrete is a kind of lightweight insulation material formed by the uniform mixture of foam and cement slurry. The superhydrophobic bulk modification of foamed concrete can reduce its high water absorption and prolong its service life. In this paper, the compatibility of three hydrophobic agents named polydimethylsiloxane (PDMS), isoctyltriethoxysilane (ICTS) and SBT®-TIA with foams was studied, and the reasons of incompatibility were revealed. Then, the superhydrophobic bulk foamed concrete system was constructed by physical foaming method, adding polydimethylsiloxane (PDMS), calcium stearate (CS), nano-silica (NS) and covering the surface of the specimen with 200-mesh wire mesh. The results show that the maximum contact angles of the meshed surface and the internal polished surface of superhydrophobic foamed concrete were 162.7° and 153.5°, respectively. At the same time, the water absorption rate of the modified specimen was significantly reduced, and the reduction rate was up to 90 %. In addition, the deterioration degree of thermal insulation performance after soaking and the dry shrinkage rate were significantly reduced compared with ordinary foamed concrete. Scanning electron microscopy (SEM) revealed that increasing the multi-scale roughness could improve the hydrophobic properties of foamed concrete. Fourier infrared spectroscopy (FT-IR) also confirmed that low surface energy groups such as -CH2 and -CH3 in PDMS bonded to the cement hydration products, indicating the successful preparation of superhydrophobic bulk foamed concrete.

Transparent material polishing surface classification based on the microfacet shape factor, reflectivity, and transmissivity features using an imaging model of a time-of-flight camera

Transparent material polishing surface classification based on the microfacet shape factor, reflectivity, and transmissivity features using an imaging model of a time-of-flight camera

Influence of substrate surface roughness on the adhesion of magnetron sputtered Cr coating

Cr coatings were deposited on both the polished and rough substrate using DC magnetron sputtering. The influence of substrate surface roughness on the morphology, crystalline phase and mechanical properties of the coatings were analyzed. The results showed that surface roughness had a significant effect on the surface morphology of the coating, as the coating inherited the surface morphology of the substrate. Surface roughness before and after coating for the polished and rough surfaces were 0.054–0.046 and 0.107–0.563[Formula: see text][Formula: see text]m, respectively. The hardness and Young’s modulus of the coating deposited on the polished surface were 5.5 and 188.6[Formula: see text]GPa, respectively, while the mechanical properties of the coating deposited on the rough surface are about the same. The results showed that the adhesion of the coating can be improved by appropriately increasing the surface roughness.

El Paso Formation: A key unit for the correlation of the Carboniferous glaciation in the Calingasta-Uspallata basin of western Argentina

The Late Paleozoic successions exposed along the western flank of the Precordillera at the latitude of Barreal in western Argentina are characterized by mid-Carboniferous glacial marine and glacially-influenced sediments (San Eduardo Group sensu Mésigos, 1953), followed by shallow marine, sand-rich deposits (Barreal Group).The El Paso Formation, exposed in the homonymous brachyanticline, is here subdivided into six facies associations (FAs), in ascending stratigraphic order: Boulder Conglomerate Complex FA, Sandstone Complex FA, Mudstones with Gastropods FA, Diamictite Complex FA, and Mudstones and Fine Sandstones FA. This analysis focuses on climatically sensitive facies related to the late Paleozoic Ice Age (LPIA), evidence of which is recorded in the adjacent Hoyada Verde Formation. The Boulder Conglomerate Complex FA includes boulders with striations on polished surfaces, indicative of glacially derived material. It grades up to sandstones with tangential cross-bedding and wave ripples, indicative of deposition as delta-scale sand-prone subaqueous clinoforms along a slope. The Diamictite Complex FA includes ice-rafted detritus (IRD) in two of its facies (dropstone mudstones and thin-bedded diamictites). The postglacial flooding, identified in various basins of western Argentina, is also present in the uppermost interval of the El Paso Formation (Mudstones and Fine Sandstones FA). It includes mudstones and rippled sandstones with abundant invertebrate fauna mainly brachiopods, bivalves, and gastropods, accompanied by conulariids, nautiloids, ostracods and corals, associated with palynomorphs. This study demonstrates through several lines of evidence that the upper interval of the El Paso and the Hoyada Verde Formations are time equivalent and represent key localities for the mid-Carboniferous (Serpukhovian-Early Bashkirian) event of the LPIA in the Calingasta Uspallata basin. Furthermore, unlike in the Hoyada Verde Formation, where the Carboniferous/pre-Carboniferous ("Pre-Tillítico") unconformity contact is concealed, the El Paso basal coarse fill rests on basement. The lower interval of the El Paso Formation exhibits similar facies characteristics and fining-upwards stacking pattern to the lower interval of the Majaditas Formation exposed further south.