Journal articles: 'Scratch'

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Liu, Yan Yan, Laura G. Gladkis, and Heiko Timmers. "Micro-Scratching of UHMW Polyethylene Surfaces." Materials Science Forum 654-656 (June 2010): 2455–58. http://dx.doi.org/10.4028/www.scientific.net/msf.654-656.2455.

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Ultra-high molecular weight polyethylene has been micro-scratched with 90° cube corner tips. The scratch mode was flat-on, uni-directional and single pass. The micro-scratches and cross-sectional scratch profiles were characterised with atomic force microscopy. No detached debris is produced. Cross-sectional scratch profiles have been analysed using Zum Gahr’s formalism giving an fab ratio slightly above zero. This is consistent with expectation for ductile polymers where none or little detached debris is produced. However, the observation contrasts with that for other polymers, such as PMMA, PEP and PC, for which inconclusive results suggest an excess pile-up implying an inconceivable change of mass density or material gain.

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Shi, Xin Hong, and Mei Juan Shan. "Effect of Scratch Depths on Fatigue Properties of PMMA for Aircraft Canopies." Applied Mechanics and Materials 687-691 (November 2014): 81–84. http://dx.doi.org/10.4028/www.scientific.net/amm.687-691.81.

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A series of fatigue tests is performed for polymethyl methacrylate (PMMA) specimens without scratches and with scratches. The scratch depth is set to be 0.2mm, 0.3mm and 0.4mm, respectively. Based on the experimental results, it can be deduced that contained fatigue limit of specimens with scratches significantly decreases compared to specimens without scratches. Besides, contained fatigue limit decreases gradually with scratch depth increasing from 0.0mm to 0.4mm. Consequently, it can be concluded that fatigue properties of PMMA will decrease when there exists scratch and for scratch depth from 0.0mm to 0.4mm, fatigue property decreases remarkably with deeper scratch.

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Jucius, Lazauskas, and Gudaitis. "Multiple Hydrogen-Bonding Assisted Scratch–Healing of Transparent Coatings." Coatings 9, no. 12 (November 26, 2019): 796. http://dx.doi.org/10.3390/coatings9120796.

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The partial cross-linking reaction of poly(vinyl alcohol) (PVA) by esterification using poly(acrylic acid) (PAA) as a cross-linking agent was performed to obtain a PVA–PAA supramolecular polymer complex. The PVA–PAA coatings with a different molar ratio between hydroxyl and carboxyl groups were prepared to examine scratch–healing ability. These coatings exhibited high optical transparency and excellent scratch–healing properties, which are attributed to considerable amount of free hydroxyl groups at the scratched interfaces to reversibly form multiple hydrogen bonds. Importantly, the PVA–PAA polymer was capable of initiating scratch recovery at temperature of 20 °C and relative humidity (RH) of 40%. Scratches produced on the PVA–PAA polymer coatings with different constant loading in the range of 1.5–2.7 N were healed significantly more rapidly under humid conditions (RH = 99%). Increase of cross-linking temperature also resulted in similar effect but with some reduction of the final scratch healing ratio.

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Mengesha, Betelhiem N., Andrew C. Grizzle, Wondwosen Demisse, Kate L. Klein, Amy Elliott, and Pawan Tyagi. "Machine Learning-Enabled Quantitative Analysis of Optically Obscure Scratches on Nickel-Plated Additively Manufactured (AM) Samples." Materials 16, no. 18 (September 20, 2023): 6301. http://dx.doi.org/10.3390/ma16186301.

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Additively manufactured metal components often have rough and uneven surfaces, necessitating post-processing and surface polishing. Hardness is a critical characteristic that affects overall component properties, including wear. This study employed K-means unsupervised machine learning to explore the relationship between the relative surface hardness and scratch width of electroless nickel plating on additively manufactured composite components. The Taguchi design of experiment (TDOE) L9 orthogonal array facilitated experimentation with various factors and levels. Initially, a digital light microscope was used for 3D surface mapping and scratch width quantification. However, the microscope struggled with the reflections from the shiny Ni-plating and scatter from small scratches. To overcome this, a scanning electron microscope (SEM) generated grayscale images and 3D height maps of the scratched Ni-plating, thus enabling the precise characterization of scratch widths. Optical identification of the scratch regions and quantification were accomplished using Python code with a K-means machine-learning clustering algorithm. The TDOE yielded distinct Ni-plating hardness levels for the nine samples, while an increased scratch force showed a non-linear impact on scratch widths. The enhanced surface quality resulting from Ni coatings will have significant implications in various industrial applications, and it will play a pivotal role in future metal and alloy surface engineering.

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Shi, Xin Hong, and Mei Juan Shan. "Effect of Scratch Depths on Tensile Strength of PMMA for Aircraft Canopies." Advanced Materials Research 1056 (October 2014): 8–11. http://dx.doi.org/10.4028/www.scientific.net/amr.1056.8.

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Static tensile tests of polymethyl methacrylate (PMMA) specimens without scratches and containing a scratch whose depth was set to be 0.2mm, 0.3mm and 0.4mm, respectively, were carried out to explore effect of scratch depths on tensile strength of PMMA. Based on the experimental load-displacement curves, the specimens without scratches deform most severely when the failure comes forth. The failure deformation declines gradually with higher scratch depth, namely higher scratch depth leads to lower plastic deformation. It thus follows that the scratch significantly reduces the tensile strength of PMMA while the variation of the scratch depth from 0.2mm to 0.4mm has negligible influence on the tensile strength of PMMA.

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Gao, Weimin, Lijing Wang, Jolanta K. Coffey, Hongren Wu, and Fugen Daver. "Finite Element Modelling and Experimental Validation of Scratches on Textured Polymer Surfaces." Polymers 13, no. 7 (March 25, 2021): 1022. http://dx.doi.org/10.3390/polym13071022.

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Surface texturing is a common modification method for altering the surface properties of a material. Predicting the response of a textured surface to scratching is significant in surface texturing and material design. In this study, scratches on a thermoplastic material with textured surface are simulated and experimentally tested. The effect of texture on scratch resistance, surface visual appearance, surface deformation and material damage are investigated. Bruise spot scratches on textured surfaces are found at low scratch forces (<3 N) and their size at different scratch forces is approximately the same. There is a critical point between the bruise spot damage and the texture pattern damage caused by continuous scratching. Scratch resistance coefficients and an indentation depth-force pattern are revealed for two textured surfaces. A texture named “Texture CB” exhibits high effectiveness in enhancing scratch visibility resistance and can increase the scratch resistance by more than 40% at low scratch forces. The simulation method and the analysis of the power spectral density of the textured surface enable an accurate prediction of scratches.

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Duan, Miaomiao, Zhufeng Yue, and Qianguang Song. "Effect of Superficial Scratch Damage on Tension Properties of Carbon/Epoxy Plain Weave Laminates." Advances in Civil Engineering 2021 (March 31, 2021): 1–8. http://dx.doi.org/10.1155/2021/5590448.

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The effect of scratch damage on the tension properties of carbon fiber plain weave laminates has been studied in detail using digital image correlation (DIC) and acoustic emission (AE). A range of scratch lengths was machined onto different laminates. The bearing capacity of the laminates was then compared with that of unaltered samples. The strain field distributions near the scratches were measured and analyzed as a function of scratch length with DIC. Initiation and propagation of damage were monitored during the tensile tests using AE. Failure sites and morphologies were observed and analyzed. The results show that superficial scratches have little effect on the strength of plain weave laminates when the scratch length is less than 80% of the specimen width. Scratches affect the distribution of strain near the scratch but not far away from the scratch or at the back face of the sample. Not all samples broke from the scratch site but instead broke from the free edge of the sample or close to the gripping region.

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Zhou, Guangqi, Ye Tian, Feng Shi, Ci Song, Guipeng Tie, Shijie Liu, Gang Zhou, Jianda Shao, and Zhouling Wu. "Scratch Morphology Transformation: An Alternative Method of Scratch Processing on Optical Surface." Micromachines 12, no. 9 (August 27, 2021): 1030. http://dx.doi.org/10.3390/mi12091030.

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The scratches on an optical surface can worsen the performance of elements. The normal process method is removing scratches entirely. However, it is a tough and high-cost requirement of removing extremely deep scratches and maintaining all the other excellent indicators at the same time. As the alternative of removing, we propose the method of scratch morphology transformation to diminish the drawbacks induced by scratches. We measure the morphology of scratches, establish the transformation models and transform them to the needed shape. In engineering applications, transformation can solve scratch drawbacks or limitations in an efficient and effective way. Then, residual scratches become acceptable. The transformation can also be amalgamated into the error figuring processes. Typical scratch transforming examples are experimented and AFM measurement is conducted. We explore the rule of scratch morphology transformation by two typical fabrication means: magnetorheological finishing (MRF) and HF etching. This morphology transforming method is an economical alternative for current defect-free fabrication. That will significantly decrease fabrication time, cost and risk, while the optical quality maintain.

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Tan, Zhiying, Yan Ji, Zhongwen Fei, Xiaobin Xu, and Baolai Zhao. "Image-Based Scratch Detection by Fuzzy Clustering and Morphological Features." Applied Sciences 10, no. 18 (September 17, 2020): 6490. http://dx.doi.org/10.3390/app10186490.

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Detection of scratch defects on randomly textured surfaces remains challenging due to their unnoticeable visual features. In this paper, an algorithm for piezoelectric ceramic plate surface scratch defects based on the combination of fuzzy c-means clustering and morphological features is proposed. Foreground membership of each gray value is calculated firstly on a reference set of training images by fuzzy c-means clustering and the interpolation method, then an enhanced image is obtained by multiplying the foreground membership function and gray image. The location relationship between regions and the gradient direction of regions is extracted from the binary image of the enhanced image. Based on the morphological features, isolated non-scratched defects are filtered out and the intermittent scratches are merged. Experiments show that the algorithm can be used to detect scratch defects on the surface of a piezoelectric ceramics plate with randomly textured surfaces.

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Dong, Zhi Gang, and C. W. Kang. "Study on Deformation and Damage of Single Crystal MgO by Micro-Scratch." Advanced Materials Research 126-128 (August 2010): 940–45. http://dx.doi.org/10.4028/www.scientific.net/amr.126-128.940.

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Scratch experiments were performed on MgO (001) plane along different crystallographic orientations with the gradually increased forces to investigate the deformaton and damage of MgO. The normal and lateral forces during scratch, as well as the topography characteristics of the residual scratch along different crystallographic orientations were compared and analyzed. The cracks propagation around the scratch were studied. The patterns of cracks and scratches were found to be very different when scratching along different crystallographic orientations. The mechanism of cracks forming beside the scratches on single crystal MgO was discussed.

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Ersoy, Orkun, Sinan Fidan, Harun Köse, Dilek Güler, and Ömer Özdöver. "Effect of Calcium Carbonate Particle Size on the Scratch Resistance of Rapid Alkyd-Based Wood Coatings." Coatings 11, no. 3 (March 17, 2021): 340. http://dx.doi.org/10.3390/coatings11030340.

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Polymer-based wood coatings are used for aesthetic purposes as well as to protect wood surfaces, especially under external conditions. High-hardness mineral fillers are thought to enhance the resistance of these polymer coatings to wear and scratching. However, recent studies suggest that the relatively low-hardness mineral calcite (CaCO3, Mohs hardness of 3) performs similarly to harder minerals under external conditions. It can replace more expensive hard minerals, thus driving research interest in its use. In this study, CaCO3 powders with different grain sizes were applied to rapid alkyd-based coating formulations, and the effect of CaCO3 particle size on the scratch behavior of the coatings was investigated under identical test conditions. The scratch morphologies, scratch hardness, and roughness values of the scratched surfaces indicated that the surfaces of the rapid alkyd-based wood coatings including finer-grained CaCO3 experienced plastic plowing-type deformation in the form of regular, narrow, and shallow scratches, showing high scratch resistance. Coatings using coarser-grained CaCO3 experienced more extensive plastic deformation of the plowing–tearing type owing to the weaker filler–polymer interface and the breakage of larger coating pieces from the coating surface.

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Zhao, Xu, Yadong Gong, Ming Cai, and Bing Han. "Numerical and Experimental Analysis of Material Removal and Surface Defect Mechanism in Scratch Tests of High Volume Fraction SiCp/Al Composites." Materials 13, no. 3 (February 10, 2020): 796. http://dx.doi.org/10.3390/ma13030796.

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This paper addresses a comprehensive and further insight into the sensitivity of material removal and the surface defect formation mechanism to scratch depth during single-grit scratch tests of 50 vol% SiCp/Al composites. The three-dimensional (3D) finite element model with more realistic 3D micro-structure, particle-matrix interfacial behaviors, particle-particle contact behaviors, particle-matrix contact behaviors and a Johnson-Holmquist-Beissel (JHB) model of SiC was developed. The scratch simulation conducted at scratch velocity 10 mm/min and loading rate 40 N/min revealed that the scratch depth plays a crucial role in material removal and the surface forming process. Brittle fracturing of SiC particles and surface defects become more deteriorative under a large scratch depth ranging from 0.0385 to 0.0764 μm. The above phenomenon can be attributed to the influence of scratch depth on SiC particles’ transport; the increase in the amount of SiC particle transport resulting from an increase of scratch depth raises the occurrence of particle-particle collision which provides hard support and shock for the scratched particles; therefore, brittle fracturing gradually becomes the major removal mode of SiC particles as the scratch depth increases. On the deteriorative surface, various defects are observed; i.e., lateral cracks, interfacial debonding, cavies filled with residually broken particles, etc. The von Mises stress distribution shows that SiC particles bear vast majority of load, and thus present greater stress than the surrounding Al matrix. For example: their ratio of 3 to 30 under the scratch depth of 0.011 mm. Namely, SiC particles impede stress diffusion within the Al matrix. Finally, the SEM images of the scratched surface obtained from the single-grit scratch experiments verify the numerical analysis’s results.

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Liang, Qingchen, Peng Liang, Feng Guo, Shuyi Li, Xiaohan Zhang, and Fulin Jiang. "The Influence of Scratches on the Tribological Performance of Friction Pairs Made of Different Materials under Water-Lubrication Conditions." Lubricants 11, no. 10 (October 17, 2023): 449. http://dx.doi.org/10.3390/lubricants11100449.

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Water-lubricated bearings are widely used in marine equipment, and the lubricating water often contains hard particles. Once these particles enter the gap between the bearing and the shaft, they can scratch the smooth surfaces of the shaft and bearing, influencing the working performance of the bearing system. To investigate the effect of scratch parameters on tribological performance, this paper conducts multiple block-on-ring experiments and constructs a mixed-lubrication model under water-lubrication conditions. The results show that among the three commonly used bearing materials, the tribological performance of graphite block is the most sensitive to scratches on the test ring surface. Under the condition of one scratch (N = 1), the loading area of water film pressure is divided into two separate zones (a trapezoidal pressure zone and an extremely low-pressure zone). In addition, the variation of maximum water film pressure is determined by the positive effect (hydrodynamic pressure effect of fluid) and negative effect (“piercing effect” of the asperities). Compared with the scratch depth and scratch location, the scratch width has the most significant effect on the tribological performance of the block-on-ring system. The maximum contact pressure is located at both edges of the scratch due to the formation of a water sac structure. The scratch has a great influence on the transition of the lubrication state of the block-on-ring system. The existence of scratches increases the critical speed at which the lubrication state transits from mixed-lubrication to elastohydrodynamic lubrication, and the critical speed is directly proportional to the scratch width.

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Shao, Mingyue, Jimei Wu, Yan Wang, Hongmei Zhang, and Qiumin Wu. "Transverse Vibration of a Moving Viscoelastic Hard Membrane Containing Scratches." Mathematical Problems in Engineering 2019 (January 22, 2019): 1–13. http://dx.doi.org/10.1155/2019/5671361.

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The transverse vibration and stability of a moving viscoelastic hard printing membrane containing scratches are investigated. Based on the viscoelastic differential constitutive relation, thin plate theory, and d’Alembert principle, the differential equation of a moving viscoelastic hard membrane with a straight scratch through the surface is derived by using the continuity condition of the scratches. The complex characteristic equation is obtained by using the differential quadrature method. The effects of the scratch depth and scratch position on the critical instability speed of the moving hard membrane were highlighted by solving the differential equation and numerical calculation, and the coupling effects of speed and scratch depth on vibration characteristics of the hard membrane are also analyzed. Numerical calculation results show that the hard membrane experiences divergence instability when the actual printing speed is v=23.2 m/s, and the membrane is stable when v<23.2 m/s. The theoretical guidance and method for scratches detection of the precision coated hard membrane are provided.

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MUSÍLEK, Michal. "PROJECT SCRATCH." Journal of Technology and Information 5, no. 1 (April 1, 2013): 102–6. http://dx.doi.org/10.5507/jtie.2013.015.

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Nιder, Zoltαn, Kαroly Vαradi, and Klaus Friedrich. "Quantitative Evaluation of Wear Grooves in a Fine Particulate Reinforced, Soft Polymer Coating System by Laser Profilometry and Computer Aided Scratch Analysis." Advanced Composites Letters 9, no. 5 (September 2000): 096369350000900. http://dx.doi.org/10.1177/096369350000900501.

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After certain periods of practical application, particulate reinforced polymer coated surfaces frequently contain many grooves due to a scratching contact with any abrasive counterparts. To characterise these scratch patterns a software package (SCRATCH) has been developed using digitised surface roughness data from a laser profilometer. The SCRATCH system identifies individual scratches by representing their locations (using a slicing technique) and specifies scalar parameters (such as the specific scratch area or mid-tangent of the bearing area curve). In this way, the magnitude of the scratch damage can be identified following an approximate technique. This is demonstrated here for wear grooves in a polymer coating system subjected to a particular scratch test. But the method can also be applied to other engineering surfaces, e.g. for wear evaluation of composite bearings, seals and other sliding composite elements.

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Furue, Kazuhisa, Takamichi Ito, Yuka Tanaka, Akiko Hashimoto-Hachiya, Masaki Takemura, Maho Murata, Makiko Kido-Nakahara, Gaku Tsuji, Takeshi Nakahara, and Masutaka Furue. "The EGFR-ERK/JNK-CCL20 Pathway in Scratched Keratinocytes May Underpin Koebnerization in Psoriasis Patients." International Journal of Molecular Sciences 21, no. 2 (January 9, 2020): 434. http://dx.doi.org/10.3390/ijms21020434.

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Epidermal keratinocytes represent a rich source of C-C motif chemokine 20 (CCL20) and recruit CCR6+ interleukin (IL)-17A–producing T cells that are known to be pathogenic for psoriasis. A previous study revealed that scratch injury on keratinocytes upregulates CCL20 production, which is implicated in the Koebner phenomenon characteristically seen in psoriasis patients. However, the molecular mechanisms leading to scratch-induced CCL20 production remain elusive. In this study, we demonstrate that scratch injury upregulates the phosphorylation of epidermal growth factor receptor (EGFR) and that the specific EGFR inhibitor PD153035 attenuates scratch-induced CCL20 upregulation in an extracellular signal-related kinase (ERK)-dependent, and to a lesser extent, a c-Jun N-terminal kinase (JNK)-dependent but p38 mitogen-activated protein kinase (MAPK)–independent manner. Immunoreactive CCL20 was visualized in the keratinocytes that lined the scratched wound. IL-17A also induced the phosphorylation of EGFR and further augmented scratch-induced CCL20 upregulation. The EGFR-ERK/JNK-CCL20 pathway in scratched keratinocytes may explain why Koebnerization is frequently seen in psoriasis patients.

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Ghasemi, Rohollah, and Anders E. W. Jarfors. "Scratch Behaviour of Silicon Solid Solution Strengthened Ferritic Compacted Graphite Iron (CGI)." Materials Science Forum 925 (June 2018): 318–25. http://dx.doi.org/10.4028/www.scientific.net/msf.925.318.

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The present study focuses on scratch behaviour of a conventional pearlitic and a number of solid solution strengthened ferritic Compacted Graphite Iron (CGI) alloys. This was done by employing a single-pass microscratch test using a sphero-conical diamond indenter under different constant normal loads conditions. Matrix solution hardening was made by alloying with different content of Si alloy; (3.66, 4.09 and 4.59 wt%. Si) which are named as low-Si, medium-Si and high-Si ferritic CGI alloys, respectively. A good correlation between the tensile and scratch test results was observed explaining the influence of CGI’s matrix characteristics on scratch behaviour both for pearlitic and fully ferritic solution strengthened ones. Both the scratch depth and scratch width showed strong tendency to increase with increasing the normal load, however the pearlitic one showed more profound deformation compared to the solution strengthened CGI alloys. Among the investigated alloys, the maximum and minimum scratch resistance was observed for high-Si ferritic CGI and pearlitic alloys, respectively. It was confirmed by the scratched surfaces analysed using Scanning Electron Microscopy (SEM) as well. In addition, the indenter’s depth of penetration value (scratch depth) was found as a suitable measure to ascertain the scratch resistance of CGI alloys.Keywords: Silicon solution strengthening, CGI, Abrasion, Scratch testing, Scratch resistance

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Tassoni, John Paul. "Editor's Introduction: Scratch Beyond Scratch." Open Words: Access and English Studies 9, no. 1 (2015): 1–3. http://dx.doi.org/10.37514/opw-j.2015.9.1.01.

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da Silva, Dayanne Lopes, Emanuel Santos, Sérgio de Souza Camargo, and Antônio Carlos de Oliveira Ruellas. "Infrared spectroscopy, nano-mechanical properties, and scratch resistance of esthetic orthodontic coated archwires." Angle Orthodontist 85, no. 5 (November 24, 2014): 777–83. http://dx.doi.org/10.2319/070314-472.1.

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ABSTRACT Objective: To evaluate the material composition, mechanical properties (hardness and elastic modulus), and scratch resistance of the coating of four commercialized esthetic orthodontic archwires. Materials and Methods: The coating composition of esthetic archwires was assessed by Fourier-transform infrared spectroscopy (FTIR). Coating hardness and elastic modulus were analyzed with instrumented nano-indentation tests. Scratch resistance of coatings was evaluated by scratch test. Coating micromorphologic characteristics after scratch tests were observed in a scanning electron microscope. Statistical differences were investigated using analysis of variance and Tukey post hoc test. Results: The FTIR results indicate that all analyzed coatings were markedly characterized by the benzene peak at about 1500 cm−1. The coating hardness and elastic modulus average values ranged from 0.17 to 0.23 GPa and from 5.0 to 7.6 GPa, respectively. Scratch test showed a high coating elasticity after load removal with elastic recoveries >60%, but different failure features could be observed along the scratches. Conclusion: The coatings of esthetic archwires evaluated are probably a composite of polyester and polytetrafluoroethylene. Delamination, crack propagation, and debris generation could be observed along the coating scratches and could influence its durability in the oral environment.

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Jia, Huakun, Huimin Zhou, Zhehao Chen, Rongke Gao, Yang Lu, and Liandong Yu. "Research on Bearing Surface Scratch Detection Based on Improved YOLOV5." Sensors 24, no. 10 (May 9, 2024): 3002. http://dx.doi.org/10.3390/s24103002.

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Bearings are crucial components of machinery and equipment, and it is essential to inspect them thoroughly to ensure a high pass rate. Currently, bearing scratch detection is primarily carried out manually, which cannot meet industrial demands. This study presents research on the detection of bearing surface scratches. An improved YOLOV5 network, named YOLOV5-CDG, is proposed for detecting bearing surface defects using scratch images as targets. The YOLOV5-CDG model is based on the YOLOV5 network model with the addition of a Coordinate Attention (CA) mechanism module, fusion of Deformable Convolutional Networks (DCNs), and a combination with the GhostNet lightweight network. To achieve bearing surface scratch detection, a machine vision-based bearing surface scratch sensor system is established, and a self-made bearing surface scratch dataset is produced as the basis. The scratch detection final Average Precision (AP) value is 97%, which is 3.4% higher than that of YOLOV5. Additionally, the model has an accuracy of 99.46% for detecting defective and qualified products. The average detection time per image is 263.4 ms on the CPU device and 12.2 ms on the GPU device, demonstrating excellent performance in terms of both speed and accuracy. Furthermore, this study analyzes and compares the detection results of various models, demonstrating that the proposed method satisfies the requirements for detecting scratches on bearing surfaces in industrial settings.

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Polsawat, Achinee, Warunee Tipcharoen, and Apirat Siritaratiwat. "Utilization of CD and DVD Pick-Up Heads for Scratch Inspection of Magnetic Disk in Dynamic State Using Microcontroller." Applied Sciences 10, no. 19 (October 1, 2020): 6897. http://dx.doi.org/10.3390/app10196897.

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A non-destructive technique to inspect a scratch on all magnetic disks in the beginning process of hard disk drive (HDD) manufacturing by using CD and DVD pick-up heads as the detector is proposed. It requires a 100% disk inspection of micrometer-sized scratches in a quick measurement with low cost inventing. Most of the previous studies were in static state but this is the first time to be done in dynamic study using the microcontroller in order to promptly serve for industrial utilization. The size, position, and shape characteristic of scratches are examined using light reflection technique. The results show that, when the laser beam is targeted on a magnetic disk in a position, either scratch or non-scratch, the reflected light intensity differs. The DVD pick-up head can detect the width and the surface characteristic of the scratches, which is similar to the results from scanning electron microscope (SEM) for all scratches sizes less than 100 µm. It is also found that using a DVD pick-up head provides a better resolution of shape characteristic and roughness of scratches surface than a CD pick-up head. Hence, the scratch size of 10s µm scale on the magnetic disk can be accurately characterized by this proposed technique, which can be further utilized for magnetic disk inspection in the hard disk drive manufacturing process.

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Domínguez-Domínguez, Guzman, Fernando Mas, and Carpoforo Vallellano. "A Preliminary Geometrical Characterization of Surface Scratches on Aluminium Alloys Used in the Aerospace Industry." Key Engineering Materials 955 (September 27, 2023): 73–80. http://dx.doi.org/10.4028/p-jxyss4.

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Surface marks, such as scratches or cosmetic marks, commonly appear during the manufacturing phase of metallic components, because of the contact between tools and sharp edges with the surface of the parts. Scratches, depending on their width, depth, and root radius, cause a decrease in the fatigue life of metallic alloys. In particular, the presence of scratches with a size comparable to the grain size favors the generation of fatigue cracks in these features. In the aerospace industry, the presence of surface marks is a common cause of rejection. The low hardness of aluminium, a material widely employed in the manufacture of aerospace structures, contributes to the generation of surface marks. In this paper, a preliminary geometrical characterisation of scratches is established. It aims to define a set of parameters to characterise exhaustively the different scratches and to generate different behavior models for each type of scratch. Parameters such as scratch length, path radius, and burr height are considered in addition to the well-known parameters such as scratch depth, root radius, and open angle.

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Slesinger, W. "Scratch." Interdisciplinary Studies in Literature and Environment 6, no. 2 (July 1, 1999): 213. http://dx.doi.org/10.1093/isle/6.2.213.

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Resnick, Mitchel, John Maloney, Andrés Monroy-Hernández, Natalie Rusk, Evelyn Eastmond, Karen Brennan, Amon Millner, et al. "Scratch." Communications of the ACM 52, no. 11 (November 2009): 60–67. http://dx.doi.org/10.1145/1592761.1592779.

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Donaldson, Alastair F., Daniel Kroening, and Philipp Ruemmer. "SCRATCH." ACM SIGPLAN Notices 46, no. 8 (September 7, 2011): 311–12. http://dx.doi.org/10.1145/2038037.1941604.

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Stern, Peter. "To scratch or not to scratch." Science 355, no. 6329 (March 9, 2017): 1035.1–1035. http://dx.doi.org/10.1126/science.355.6329.1035-a.

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Alishahedani, Mohammadali E., Manoj Yadav, Katelyn J. McCann, Portia Gough, Carlos R. Castillo, Jobel Matriz, and Ian A. Myles. "Therapeutic candidates for keloid scars identified by qualitative review of scratch assay research for wound healing." PLOS ONE 16, no. 6 (June 18, 2021): e0253669. http://dx.doi.org/10.1371/journal.pone.0253669.

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The scratch assay is an in vitro technique used to analyze cell migration, proliferation, and cell-to-cell interaction. In the assay, cells are grown to confluence and then ‘scratched’ with a sterile instrument. For the cells in the leading edge, the resulting polarity induces migration and proliferation in attempt to ‘heal’ the modeled wound. Keloid scars are known to have an accelerated wound closure phenotype in the scratch assay, representing an overactivation of wound healing. We performed a qualitative review of the recent literature searching for inhibitors of scratch assay activity that were already available in topical formulations under the hypothesis that such compounds may offer therapeutic potential in keloid treatment. Although several shortcomings in the scratch assay literature were identified, caffeine and allicin successfully inhibited the scratch assay closure and inflammatory abnormalities in the commercially available keloid fibroblast cell line. Caffeine and allicin also impacted ATP production in keloid cells, most notably with inhibition of non-mitochondrial oxygen consumption. The traditional Chinese medicine, shikonin, was also successful in inhibiting scratch closure but displayed less dramatic impacts on metabolism. Together, our results partially summarize the strengths and limitations of current scratch assay literature and suggest clinical assessment of the therapeutic potential for these identified compounds against keloid scars may be warranted.

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Rybnicek, Jan, Ralf Lach, Jan Schöne, David Tondl, Silvia Rial Dominguez, Robert Valek, and Wolfgang Grellmann. "Microstructure-Related Scratch Resistance and Indentation Creep Behavior of PA6 and PA6 Nanocomposites." Key Engineering Materials 592-593 (November 2013): 586–89. http://dx.doi.org/10.4028/www.scientific.net/kem.592-593.586.

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Instrumented scratch test was carried out to determine the scratch resistance of polyamide 6 (PA 6) nanocomposites, where two kinds of nanofillers were tested, both based on silicates: montmorillonite (MMT) and halloysite nanotubes (HNT). In this work the influence of the sliding velocity, normal applied load and time-dependent recovery on the penetration depth and scratch hardness was investigated. Optical microscopy was utilized to determine the width of the scratch grooves and scanning electron microscopy revealed the damage features of the scratched surfaces. Both MNT and HNT nanofillers improve the scratch resistance of PA 6 considerably. As a result of the microstructure of the polymer nanocomposites MNT gives PA 6 a better residual depth resistance while HNT raises its scratch hardness (i.e. reduces the scratch width). Furthermore, via different depth-sensing indentation techniques in the nano-, micro- and macro-range of loading the short-term performance (Martens hardness and indentation modulus) and the time-dependent creep behavior have been analyzed for PA 6 and the PA 6 nanocomposites as a function of applied load and temperature. Additionally, WAXS (wide-angle X-ray scattering) and DSC (differential scanning calorimetry) measurements to establish morphology–property relationships of the materials investigated considering the skin–core structure of the injection molded samples were made.

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Tharajak, Jirasak, Tippaban Palathai, and Narongrit Sombatsompop. "Scratch Resistance and Adhesion Properties of PEEK Coating Filled with h-BN Nanoparticles." Advanced Materials Research 747 (August 2013): 303–6. http://dx.doi.org/10.4028/www.scientific.net/amr.747.303.

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Effects of h-BN particles on mechanical properties and adhesion of semi-crystalline poly (ether-ether-ketone) (PEEK) coatings were studied. PEEK powder was mixed with various contents of h-BN nanoparticle in ethanol under ultrasonic mixing. As-mixed powders were sprayed onto low carbon steel substrate with thermal spray technique. The hardness, scratch hardness, specific scratch wear rate, prevailing deformation mechanisms and adhesion were obtained from scratch tests by varying the applied load. The damage geometry on scratched polymer surfaces and scratch wear volume loss were examined using scanning electron microscope (SEM) and surface profilometer, respectively. The results indicated that the addition of h-BN content improved the hardness of the composite. In addition, the specific scratch wear rate and the adhesion between PEEK coatings and substrate decreased with increasing h-BN content. The poor adhesion resulted from the reductions of flow-ability and viscosity between PEEK and substrate caused by heat dissipation from the h-BN particles.

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Ruiz-Rebollo, M. Lourdes, Benito Velayos-Jiménez, José María Prieto de Paula, María Álvarez Quiñones, and José Manuel González Hernández. "Cat Scratch Colon." Diagnostic and Therapeutic Endoscopy 2011 (April 28, 2011): 1–2. http://dx.doi.org/10.1155/2011/875941.

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Over the past few years, we have read several publications regarding the term “cat scratch colon.” This neologism was developed to define some bright red linear markings seen in the colonic mucosa that resemble scratches made by a cat. We would like to communicate a recent case attended at our institution.

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Song, Fei, and Chen-Bo Zhong. "You scratch his back, he scratches mine and I’ll scratch yours: Deception in simultaneous cyclic networks." Journal of Economic Behavior & Organization 112 (April 2015): 98–111. http://dx.doi.org/10.1016/j.jebo.2015.01.009.

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Chowdhury, Faizul Islam, MA Kashem, Md Anwar Hossain, Imran Munadil Ahsan, Avijit Pandit, Rizwana Halim, and Gazi Yasinur Islam. "Disseminated cat-scratch disease: a case report." Journal of Dhaka Medical College 22, no. 2 (January 9, 2015): 229–31. http://dx.doi.org/10.3329/jdmc.v22i2.21550.

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Cat-scratch disease is an infectious disease caused by Bartonella henselae, a gram-negative bacillus. The disease is usually transmitted to the human being by cat scratches. Cat-scratch disease typically presents with painful regional lymphadenopathy. Systemic involvement is unusual. A 35 years old lady, came with the complaints of fever, abdominal pain along with nausea, anorexia & difficulties of swallowing for 6 months. She has painful cervical lymphadenopathy. Histopathology of her lymph node biopsy shows features of cat-scratch disease. DOI: http://dx.doi.org/10.3329/jdmc.v22i2.21550 J Dhaka Medical College, Vol. 22, No.2, October, 2013, Page 229-231

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Ulzii, Dugarmaa, Makiko Kido-Nakahara, Takeshi Nakahara, Gaku Tsuji, Kazuhisa Furue, Akiko Hashimoto-Hachiya, and Masutaka Furue. "Scratching Counteracts IL-13 Signaling by Upregulating the Decoy Receptor IL-13Rα2 in Keratinocytes." International Journal of Molecular Sciences 20, no. 13 (July 6, 2019): 3324. http://dx.doi.org/10.3390/ijms20133324.

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The vicious itch–scratch cycle is a cardinal feature of atopic dermatitis (AD), in which IL-13 signaling plays a dominant role. Keratinocytes express two receptors: The heterodimeric IL-4Rα/IL-13Rα1 and IL-13Rα2. The former one transduces a functional IL-13 signal, whereas the latter IL-13Rα2 works as a nonfunctional decoy receptor. To examine whether scratch injury affects the expression of IL-4Rα, IL-13Rα1, and IL-13Rα2, we scratched confluent keratinocyte sheets and examined the expression of three IL-13 receptors using quantitative real-time PCR (qRT-PCR) and immunofluorescence techniques. Scratch injuries significantly upregulated the expression of IL13RA2 in a scratch line number-dependent manner. Scratch-induced IL13RA2 upregulation was synergistically enhanced in the simultaneous presence of IL-13. In contrast, scratch injuries did not alter the expression of IL4R and IL13RA1, even in the presence of IL-13. Scratch-induced IL13RA2 expression was dependent on ERK1/2 and p38 MAPK signals. The expression of IL-13Rα2 protein was indeed augmented in the scratch edge area and was also overexpressed in lichenified lesional AD skin. IL-13 inhibited the expression of involucrin, an important epidermal terminal differentiation molecule. IL-13-mediated downregulation of involucrin was attenuated in IL-13Rα2-overexpressed keratinocytes, confirming the decoy function of IL-13Rα2. Our findings indicate that scratching upregulates the expression of the IL-13 decoy receptor IL-13Rα2 and counteracts IL-13 signaling.

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Zhang, Ning, Yi Chen, Edward K. Sanchez, David R. Black, and Michael Dudley. "The Effect of 4H-SiC Substrate Surface Scratches on Chemical Vapor Deposition Grown Homo-Epitaxial Layer Quality." Materials Science Forum 615-617 (March 2009): 109–12. http://dx.doi.org/10.4028/www.scientific.net/msf.615-617.109.

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The influence of substrate surface scratches on the quality of CVD grown 4H-SiC homo-epitaxial layers has been studied using a combination of post-growth Monochromatic Synchrotron X-ray Topography (MSXT) and KOH etching. MSXT observations suggest that the scratches on the substrate surface act as dislocation nucleation centers during the growth. When the scratch is along the off-cut direction, only TED-TED pairs are generated. As the inclination of the scratch to the off-cut direction increases, an increasing number of TED-BPD pairs are generated. A model is presented for a possible mechanism for the nucleation of dislocations at scratches.

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YAMAMOYO, Shozo. "Anti-Scratch Paint Development of Scratch Shield." Journal of the Society of Mechanical Engineers 112, no. 1086 (2009): 418–21. http://dx.doi.org/10.1299/jsmemag.112.1086_418.

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Price, James J., Tingge Xu, Binwei Zhang, Lin Lin, Karl W. Koch, Eric L. Null, Kevin B. Reiman, et al. "Nanoindentation Hardness and Practical Scratch Resistance in Mechanically Tunable Anti-Reflection Coatings." Coatings 11, no. 2 (February 12, 2021): 213. http://dx.doi.org/10.3390/coatings11020213.

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This work presents fundamental understanding of the correlation between nanoindentation hardness and practical scratch resistance for mechanically tunable anti-reflective (AR) hardcoatings. These coatings exhibit a unique design freedom, allowing quasi-continuous variation in the thickness of a central hardcoat layer in the multilayer design, with minimal impact on anti-reflective optical performance. This allows detailed study of anti-reflection coating durability based on variations in hardness vs. depth profiles, without the durability results being confounded by variations in optics. Finite element modeling is shown to be a useful tool for the design and analysis of hardness vs. depth profiles in these multilayer films. Using samples fabricated by reactive sputtering, nanoindentation hardness depth profiles were correlated with practical scratch resistance using three different scratch and abrasion test methods, simulating real world scratch events. Scratch depths from these experiments are shown to correlate to scratches observed in the field from consumer electronics devices with chemically strengthened glass covers. For high practical scratch resistance, coating designs with hardness >15 GPa maintained over depths of 200–800 nm were found to be particularly excellent, which is a substantially greater depth of high hardness than can be achieved using previously common AR coating designs.

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Guo, Yanbin, Lulu Huang, Yingbin Liu, Jun Liu, and Guoping Wang. "Establishment of the Complete Closed Mesh Model of Rail-Surface Scratch Data for Online Repair." Sensors 20, no. 17 (August 21, 2020): 4736. http://dx.doi.org/10.3390/s20174736.

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Rail surface scratching occurs with increasing frequency, seriously threatening the safety of vehicles and humans. Online repair of rail-surface scratches on damaged rails with scratch depths >1 mm is of increased importance, because direct rail-replacement has the disadvantages of long operation time, high manpower and high material costs. Advanced online repair of rail-surface scratch using three-dimensional (3D) metal printing technology such as laser cladding has become an increasing trend, desperately demanding a solution for the fast and precise establishment of a complete closed mesh model of rail-surface scratch data. However, there have only been limited studies on the topic so far. In this paper, the complete closed mesh model is well established based on a novel triangulation algorithm relying on the topological features of the point-cloud model (PCM) of scratch-data, which is obtained by implementing a scratch-data-computation process following a rail-geometric-feature-fused algorithm of random sample consensus (RANSAC) performed on the full rail-surface PCM constructed by 3D laser vision. The proposed method is universal for all types of normal-speed rails in China. Experimental results show that the proposed method can accurately acquire the complete closed mesh models of scratch data of one meter of 50 Kg/m-rails within 1 min.

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Yovita, Yovita, Mery Berlian, Desi Nori Sahputri, Rian Vebrianto, Dilva Hardila, and Musa Thahir. "Scracth E-Modul: Inspecting Expert Validation." AL-ISHLAH: Jurnal Pendidikan 15, no. 4 (November 10, 2023): 4355–71. http://dx.doi.org/10.35445/alishlah.v15i4.3070.

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Learning that is obtained quickly is always associated with technological developments. Scratch is a simple coding application that can be used in learning systems. This study aimed to analyze the validity of a Scratch-based E-Module learning media on the earth and the universe for grade 5 elementary schools, making the learning process more meaningful. This study used a research and development (RD) design with a quantitative descriptive approach where experts assessed the learning media that has been developed. The experts involved in this study were 9 people, including five lecturers and four certified teachers. Data were obtained using a validity test instrument to assess the E-module learning media that has been developed through meetings and explanations on how this learning media is operated, then, the experts filled the instrument out through the Google form prepared by researchers. Data were analyzed using SPPS version 23 and presented descriptively. The results show that the Scratch-Based E-Module has a validity value of 77% with very valid criteria. This demonstrates that the Scrach-Based E-Module is credible and useful for education, as stated by experts in the field. This Scratch-Based E-Module can therefore be implemented. Educators and scholars alike can benefit from this Scratch-Based E-Module.

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Li, Bingjian, Zi Yang Kang, Jiahuang Lin, Ye Yeo, and Guoxian Tan. "General theories of reflection and transmission scratch holograms." Canadian Journal of Physics 95, no. 5 (May 2017): 432–39. http://dx.doi.org/10.1139/cjp-2016-0471.

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Scratch holograms can be created easily and the associated interesting phenomena may be observed in daily life. In this paper, general and quantitative theories of scratch holograms were derived and presented. Both the reflection case where a scratch hologram reflects light, and the transmission case where it refracts and transmits light, were considered. A predictive model, which has not been presented in the literature, was developed. The model was able to solve for the position of the bright points along the scratches using a computational method. Extensive experimentation was carried out with scratch holograms of two designs to verify the model. Photographic evidence demonstrated extremely good fits with the theoretical predictions. The model was then used to theoretically simulate the 3D spatial positions of the hologram and also quantify distortion present in the images to illustrate novel real-life applications of the theories presented.

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Li, Kun Ming, Yi Wang Bao, De Tian Wan, Yan Li Huo, and Jin Yi Wu. "Evaluating Adhesion of Ceramic Coatings by Scratch Testing." Key Engineering Materials 512-515 (June 2012): 959–64. http://dx.doi.org/10.4028/www.scientific.net/kem.512-515.959.

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Adhesion is one of the most important mechanical properties of ceramic coatings. Scratch testing is considered as a simple and effective method to evaluate adhesion of ceramic coatings. In this paper, the critical normal forces and scratch morphologies for different coating-substrate systems were studied by scratch testing. It is shown that the critical normal force obtained by acoustic emission (AE) signals decreases from 12 N to 7 N when the applied normal force rate increases from 20 N/min to 100 N/min for CVD SiC on C, and the failure area of this scratched sample increases with increasing maximum normal force; Based on scratch morphologies, spallation or delamination can be observed for hard-brittle coatings on glass or metal, while discontinuous or continuous ductile perforation can be observed for ductile coatings on metal; The critical normal force for hard-brittle coatings can be effectively obtained by AE signals.

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Endo, K., H. Sumitsuji, T. Fukuzumi, J. Adachi, and T. Aoki. "Evaluation of scratch movements by a new scratch-monitor to analyze nocturnal itching in atopic dermatitis." Acta Dermato-Venereologica 77, no. 6 (December 12, 1997): 432–35. http://dx.doi.org/10.2340/0001555577432435.

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Itching is very important in atopic dermatitis, but the details of itching or scratch movements, especially during sleep at night, have not yet been fully comprehended. We designed a new, simple device, the Scratch-Monitor (SM), to evaluate scratch movements at night and assessed the usefulness of this device by a comparison involving 26 patients and 17 healthy controls. The SM, a box weighing only 25 g with a pressure sensor on the bottom, is attached to the back of each hand under a cotton glove and records the number as scratch movements per minute in the case of more than three successive changes of pressure. The SM indicated that patients with atopic dermatitis scratched more frequently and suffered more severe sleep disturbance than healthy controls. Although the SM had several problems related to specificity and sensitivity, we conclude that the SM is a useful tool for evaluating nocturnal itching.

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Khan, M. K., Michael E. Fitzpatrick, L. E. Edwards, and S. V. Hainsworth. "Determination of the Residual Stress Field around Scratches Using Synchrotron X-Rays and Nanoindentation." Materials Science Forum 652 (May 2010): 25–30. http://dx.doi.org/10.4028/www.scientific.net/msf.652.25.

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The residual strain field around the scratches of 125µm depth and 5µm root radius have been measured from the Synchrotron X-ray diffraction. Scratches were produced using different tools in fine-grained aluminium alloy AA 5091. Residual stresses up to +1700 micro-strains were measured at the scratch tip for one tool but remained up to only +1000 micro-strains for the other tool scratch. The load-displacement curves obtained from nanoindentation were used to determine the residual stresses around the scratches. It was found that the load-displacement curves are sensitive to any local residual stress field present and behave according to the type of residual stresses. This combination of nanoindentation and synchrotron X-rays has been proved highly effective for the study of small-scale residual stresses around the features such as scratches.

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Satpathy, Sweety, and Amitava Ghosh. "On Material Removal Mechanism in High Speed Single Grit Scratch-Grinding of Cryo-Treated Al2024-T351 Aluminium Alloy." Materials Science Forum 1009 (August 2020): 123–28. http://dx.doi.org/10.4028/www.scientific.net/msf.1009.123.

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Feasibility of utilizing cryogenic technology to improve the shearability of Al2024-T351 alloy is experimentally investigated by carrying out a single grit scratch-grinding test. A single grit brazed diamond grinding tool is developed for the study. Al2024-T351 work specimens are treated with liquid nitrogen for 6 hours before the scratch test. Although there was no significant change in the tensile strength of the material, the surface experiences change in the microhardness. It helps in arresting the side flow and ploughing of the material during high speed scratch grinding. The scratched grooves on cryo-treated samples, compare to those of untreated specimens, shows signs of cleaner shear-cuts, superior finish and produces less grinding force during grinding

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Yildiz, Serife Nur, Alev Ates Cobanoglu, and Tarik Kisla. "Development of the ICT Teachers’ Perceptions of the Contribution of Scratch Program to Programming Instruction Scale." International Journal of Computer Science Education in Schools 4, no. 1 (August 14, 2020): 53–71. http://dx.doi.org/10.21585/ijcses.v4i1.59.

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Scratch which is one of the block-based software for facilitating programming teaching is commonly used for beginners of learning programming. However, there is a lack of studies about the perceptions of information and communication technologies (ICT) teachers regarding the contributions of this visual programming language. Therefore, this study deals with developing a scale for measuring ICT teachers’ perceptions based on unified theory of acceptance and use of technology (UTAUT) about Scratch’s contributions in teaching programming. The sample of the study includes 265 ICT teachers from Turkish Ministry of National Education (MoNE) secondary schools who used Scratch software in their courses. According to exploratory and confirmatory factor analyses results, final version for perceptions scale of ICT teachers regarding the contributions of block-based visual programming language (Scratch) includes 28 items. The Cronbach Alpha coefficient is 0.97. This scale can help the practitioners who aims at understanding the contributions of Scratch and the other block-based visual programming languages from ICT teachers’ perspective; the researchers who wish to investigate this contribution according to various variables and the decision-makers of using Scratch in programming instruction programs.

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Hu, Qicai, Ning Huang, Ying Yan, and Ping Zhou. "Elastic deformation method for producing workpiece micro-protrusion topography in single-tip scratch test." Advances in Engineering Technology Research 1, no. 1 (May 17, 2022): 141. http://dx.doi.org/10.56028/aetr.1.1.141.

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The single-tip tool scratch test is one of the main methods to study the grinding mechanism of hard-and-brittle materials. Given the difficulty to realize nanometer high-speed scratching, this paper proposes a new single-tip tool scratch test system setup and proposes a vacuum adsorption method supported by a local elastic film to realize the micro-protrusion structure. The relationship between the film size and the micro-protrusion structure was analyzed by the finite element method. And the results showed that scratches with different depths could be obtained by controlling the width and thickness of the film. Experiments have verified that when the thickness of the film is 0.3-0.4 μm and the width of the film is about 1 mm, the scratch depth after scratching is about 100 nm, which meets the needs of scratching experiments. This study lays an important foundation for the high-speed single-tip tool scratch test.

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Huang, Minfei, Hanming Yang, Chenqi Zou, Mengyan Zang, and Shunhua Chen. "Effects of Interlaminar Failure on the Scratch Damage of Automotive Coatings: Cohesive Zone Modeling." Polymers 15, no. 3 (January 31, 2023): 737. http://dx.doi.org/10.3390/polym15030737.

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Interlaminar failure caused by scratches is a common damage mode in automotive coatings and is considered the potential trigger for irreversible destruction, i.e., plowing. This work strives to numerically investigate the mechanisms responsible for the complex scratch behavior of an automotive coating system, considering the interfacial failure. A finite element model is developed by incorporating a large deformation cohesive zone model for scratch-induced debonding simulation, where the mass scaling technique is utilized to minimize computational burden while ensuring accuracy. The delamination phenomenon of the automotive coating is reproduced, and its effects on scratch damage behavior are analyzed. Accordingly, it is revealed that the interlaminar delamination would produce significant stress redistribution, which leads to brittle and ductile damage of the coating and consequently affects the formation of plowing. Eventually, parametric studies on the effects of interfacial properties are performed. They demonstrate that the shear strength and shear fracture energy dominate scratch-induced delamination.

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Lin, Wangpiao, Naohiko Yano, Jun Shimizu, Libo Zhou, Teppei Onuki, and Hirotaka Ojima. "Analysis of Nanoscratch Mechanism of C-Plane Sapphire with the Aid of Molecular Dynamics Simulation of Hcp Crystal." Nanomaterials 11, no. 7 (July 1, 2021): 1739. http://dx.doi.org/10.3390/nano11071739.

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In this study, single groove nanoscratch experiments using a friction force microscope (FFM) with a monocrystalline diamond tip were conducted on a c-plane sapphire wafer to analyze the ductile-regime removal and deformation mechanism including the anisotropy. Various characteristics, such as scratch force, depth, and specific energy for each representative scratch direction on the c-plane of sapphire, were manifested by the FFM, and the results of the specific scratch energy showed a trend of six-fold symmetry on taking lower values than those of the other scratch directions when the scratch directions correspond to the basal slip directions as 0001⟨112¯0⟩. Since this can be due to the effect of most probably basal slip or less probably basal twinning on the c-plane, a molecular dynamics (MD) simulation of zinc, which is one of the hexagonal close-packed (hcp) crystals with similar slip/twining systems, was attempted to clarify the phenomena. The comparison results between the nanoscratch experiment and the MD simulation revealed that both the specific scratch energy and the burr height were minimized when scratched in the direction of the basal slip. Therefore, it was found that both the machining efficiency and the accuracy could be improved by scratching in the direction of the basal slip in the single groove nanoscratch of c-plane sapphire.

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Fröhlich, Marlen, Kevin Lee, Tatang Mitra Setia, Caroline Schuppli, and Carel P. van Schaik. "The loud scratch: a newly identified gesture of Sumatran orangutan mothers in the wild." Biology Letters 15, no. 7 (July 2019): 20190209. http://dx.doi.org/10.1098/rsbl.2019.0209.

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The communicative function of primates' self-directed behaviours like scratching has gained increasing attention in recent years, but their intentional use is still debated. Here, we addressed this issue by exploring the communicative function of ‘loud scratches’ in wild Sumatran orangutans. Building on previous studies in chimpanzees, we examined the prediction that audio-visual loud scratches are used communicatively in mother–infant travel coordination. Specifically, we examined whether individual, social and scratch features affected the use of pre-move scratches, markers of intentional signal use and approach responses. We analysed a total of 1457 scratching bouts, produced by 17 individuals (including four mothers and their dependent offspring) observed during 305 h of focal follows. Overall, we found that scratching bouts preceded departure mainly when these were produced by mothers and showed features of exaggeration. If the scratching individual was a mother, associates were more likely to be visually attentive during pre-move scratches than in other contexts. Approach or follow responses to scratches by individuals in association were predicted by context, the relationship with the scratcher (i.e. offspring) and the associate's attentional state. We conclude that orangutan mothers use loud scratches as communicative strategies to coordinate joint travel with their infants.

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Kafejian, Sergio. "From Scratch." Revista Vórtex 8, no. 3 (2020): 1–9. http://dx.doi.org/10.33871/23179937.2020.8.3.1.41.

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Journal articles on the topic 'Scratch'

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