Journal articles on the topic 'Surfaces – Erosion'
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1
Adamkiewicz, A., and A. Waliszyn. "Studies of Erosion Resistance of Protective Coats on the Surfaces of Machine Elements Washed with Fluids." Advances in Materials Science 18, no. 2 (June 1, 2018): 69–76. http://dx.doi.org/10.1515/adms-2017-0033.
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AbstractThis article indicated at erosion as one of the causes of degradation of surfaces washed by fluids and conditions of its occurrence. Corrosive – erosive theory of metal surface degradation has been discussed linking it with an instance of destructive processes taking place in cylinder liner blocks of combustion engines. Physics and conditions influencing processes on liquid – washed operational surface phase boundary have been justified. Out of the contemporary hypotheses explaining the physics of cavitation erosion, the bubble theory has been considered. A mathematical model of erosion has been presented in the context of cavitation implosion energy determining crash interactions of liquid cumulative fluxes on the washed surface. Occurring plastic deformations have been graphically explained linking them with the occurrence of fatigue micro-cracks and later with erosive pits. Influence of initial steel hardness on intensity of cavitation erosion has been checked. Discussion of ways to increase metal surface resistance to cavitation erosion has been carried out.
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Oberholzer, P., C. Baroni, M. C. Salvatore, H. Baur, and R. Wieler. "Dating late Cenozoic erosional surfaces in Victoria Land, Antarctica, with cosmogenic neon in pyroxenes." Antarctic Science 20, no. 1 (November 27, 2007): 89–98. http://dx.doi.org/10.1017/s095410200700079x.
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AbstractWe present 21Ne exposure ages of erosional glaciogenic rock surfaces on nunataks in northern Victoria Land, Antarctica: i) in the Prince Albert Mountains and ii) near Mesa Range. These nunataks are located directly at the margin of the polar plateau and therefore provide an immediate record of ice volume changes of the East Antarctic Ice Sheet, not biased by ice shelf grounding or narrow valley sections downstream the outlet glaciers. The sampling locations overlook the present ice surface by less than 200 m, but were last covered by ice 3.5 Ma bp (minimum age, not corrected for erosion). This strongly indicates that the ice sheet has not been substantially thicker than today since at least the early Pliocene, which supports the hypothesis of a stable East Antarctic Ice Sheet. First absolute ages are reported for the alpine topography above the erosive trimline that typically marks the upper limit of glacial activity in northern Victoria Land. Unexpectedly low nuclide concentrations suggest that erosion rates on the alpine topography are considerably higher due to the steep slopes than those affecting flat erosional surfaces carrying Antarctic tors.
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Kinnell, PIA, CJ Chartres, and CL Watson. "The effects of fire on the soil in a degraded semiarid woodland .II. Susceptibility of the soil to erosion by shallow rain impacted flow." Soil Research 28, no. 5 (1990): 779. http://dx.doi.org/10.1071/sr9900779.
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Small (500 by 250 by 100 mm) soil monoliths collected from experimental plots subjected to various fire frequencies in a semi-arid woodland near Coolabah, N.S.W., were tested for their susceptibility to erosion by rain-impacted flows under laboratory conditions. In the tests, the erosive stress applied to the soil surfaces was controlled by using drops of uniform size (2.7 mm) falling 11.2 m onto flows whose depths were controlled between 1 and 2.7 drop diameters. Experimental data and thin-section observations showed that cryptogams provide a high degree of protection against erosion. Sediment concentration (measured in g L-1) from cryptogam-covered plots was considerably less than that from both bare-crusted surfaces and surfaces dominated by depositional material. Surfaces with cryptogamic crusts were generally free of debris, but showed only minor signs of erosion, whereas bare-crusted and depositionary surfaces suffered pronounced lowering and tended to disintegrate. Because increasing fire frequency reduces the spatial distribution of the cryptogamic cover on the soil surface in the semi-arid woodlands, increasing fire frequency must increase the erosion hazard.
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Srinivasan, Sreeram, John C. Russ, and Ronald O. Scattergood. "Fractal analysis of erosion surfaces." Journal of Materials Research 5, no. 11 (November 1990): 2616–19. http://dx.doi.org/10.1557/jmr.1990.2616.
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Fractal analysis of steady-state erosion surfaces generated by erodents of widely different hardnesses on single crystal sapphire shows surprising similarities in spite of a large difference in erosion rates and single impact morphology. This study quantifies the surfaces in terms of the surface texture measurements using recently developed image analysis techniques. The interpretation for such similarities is that a single mechanism of material removal is operative for all erodents. The differences are explained in terms of the efficiency of crack initiation in the target by the two erodents.
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Selokar, Ashish, Ravi Kant, D. B. Goel, and U. Prakash. "Solid Particle Erosion Behaviour of Martensitic and Nitrogen Alloyed Austenitic Stainless Steel." Advanced Materials Research 1043 (October 2014): 45–49. http://dx.doi.org/10.4028/www.scientific.net/amr.1043.45.
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In the present work, comparison of solid particle erosive behaviour of 13/4 steel and Nitrogen alloyed austenitic stainless steel (23/8N steel) have been studied using air jet erosion testing. Air jet erosion testing has been performed at various angles for as received samples at 31 m/s velocity and a discharge rate of 3 gm per minute by alumina particles with angular shape and 53-63μm size. Microstructure, eroded surface characteristics, mechanical properties and erosion rate are characterized by using scanning electron microscope, hardness and tensile testing. 23/8N steel shows good hardness coupled with high tensile toughness and work hardening ability, which leads to improved erosion resistance. The surface morphology analysis of the worn out surfaces, cumulative weight loss measurements and steady state of erosion rate results were used to understand the effect of nitrogen on the degradation mechanisms. The results show that 23/8N steel exhibits excellent resistance to erosion in comparison to13/4 steel.
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Erdoğan, Aygen A., Erol Feyzullahoğlu, Sinan Fidan, and Tamer Sinmazçelik. "Investigation of erosive wear behaviors of AA6082-T6 aluminum alloy." Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications 234, no. 3 (January 14, 2020): 520–30. http://dx.doi.org/10.1177/1464420719899686.
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AA6082-T6 aluminum alloys are widely used in various applications in automotive and aircraft industries. They offer an attractive combination of surface properties, strength and corrosion resistance. The structural components manufactured by AA6082-T6 aluminum alloys can be exposed to impingement of solid particles throughout their service life. In this study, erosive wear behaviors of AA6082-T6 aluminum alloy were investigated. For the evaluation of erosive wear induced by solid particle impacts, a detailed study was conducted on AA6082-T6 aluminum alloy by using aluminum oxide (Al2O3) erodent particles. Two different particles were used in solid particle erosion tests, which are 60 mesh (212–300 µm) and 120 mesh (90–125 µm), respectively. Also, the aluminum alloy samples were tested under two different air pressures (1.5 bar and 3 bar). The erosive wear tests were carried out according to ASTM G76 standard at six various impact angles (15°, 30°, 45°, 60°, 75°, 90°). The surface roughness and morphology of worn samples were analyzed by using a non-contact laser profilometer. It was found that erodent particle size affected the surface erosion damage, erosion rate, crater morphology and roughness. The eroded surfaces of specimens were analyzed by SEM. The surfaces of specimens were also investigated by using EDS in SEM studies.
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Chen, Shanqun, Runchao Tang, Longzhu Zhang, and Bin Liao. "Numerical Investigation of Wind Erosion to the Grooved Concrete Wall Surface under a Wind-Blown Sand Movement." Advances in Materials Science and Engineering 2021 (January 19, 2021): 1–13. http://dx.doi.org/10.1155/2021/1604186.
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Wind erosion to the grooved concrete wall surface under a wind-blown sand movement was numerically studied. Particularly, the influencing factors that affect the wind erosion to the grooved concrete wall surface were systematically investigated by using the RNG k − ε turbulence model combined with the discrete phase model (DPM). It was found that, under a relatively low impact angle, the damage mechanism to the grooved wall surface is wind-blown sand impact, and the erosion rates of the grooved wall surfaces are higher than those of the smooth wall surfaces. By contrast, under a relatively high impact angle, the damage mechanism to the grooved wall surface transfers to the microcutting effect, and the erosion rates show an opposite trend. The optimization rates between the erosion of grooved and smooth wall surfaces increase with increasing groove size or groove number. However, the damage mechanism to the grooved wall surface is hardly changed by expanding the groove area. The erosion rate distribution and the optimization rates of the groove wall surfaces are not significantly changed by adjusting the spacing between the grooves alone. When the groove shape changes from semicircular to rectangular, the erosion rate distribution is significantly changed, and the wear resistance of the changed grooved wall surface gets better.
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Mohammadi, Bijan, and AmirSajjad Khoddami. "Representative volume element-based simulation of multiple solid particles erosion of a compressor blade considering temperature effect." Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology 234, no. 8 (November 1, 2019): 1173–84. http://dx.doi.org/10.1177/1350650119884825.
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Solid particle erosion is one of the main failure mechanisms of a compressor blade. Thus, characterization of this damage mode is very important in life assessment of the compressor. Since experimental study of solid particle erosion needs special methods and equipment, it is necessary to develop erosion computer models. This study presents a coupled temperature–displacement finite element model to investigate damage of a compressor blade due to multiple solid particles erosion. To decrease the computational cost, a representative volume element technique is introduced to simulate simultaneous impact of multiple particles. Blade has been made of Ti-6Al-4V, a ductile titanium-based alloy, which is impacted by alumina particles. Erosion finite element modeling is assumed as a micro-scale impact problem and Johnson–Cook constitutive equations are used to describe Ti-6Al-4V erosive behavior. In regard to a wide variation range in thermal conditions all over the compressor, it is divided into three parts (first stages, middle stages, and last stages) in which each part has an average temperature. Effective parameters on erosive behavior of the blade alloy, such as impact angle, particles velocity, and particles size are studied in these three temperatures. Results show that middle stages are the most critical sites of the compressor in terms of erosion damage. An exponential relation is observed between erosion rate and particles velocity. The dependency of erosion rate on size of particles at high temperatures is indispensable.
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Khan, Rehan, Hamdan H. Ya, William Pao, and Armaghan Khan. "Erosion–Corrosion of 30°, 60°, and 90° Carbon Steel Elbows in a Multiphase Flow Containing Sand Particles." Materials 12, no. 23 (November 26, 2019): 3898. http://dx.doi.org/10.3390/ma12233898.
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Erosion–corrosion in flow changing devices as a result of sand transportation is a serious concern in the hydrocarbon and mineral processing industry. In this work, the flow accelerated erosion–corrosion mechanism of 90°, 60°, and 30° long radius horizontal–horizontal (H–H) carbon steel elbows with an inner diameter of 50.8 mm were investigated in an experimental closed-flow loop. For these geometrical configurations, erosion–corrosion was elucidated for erosive slug flow regimes and the extent of material degradation is reported in detail. Qualitative techniques such as multilayer paint modeling and microscopic surface imaging were used to scrutinize the flow accelerated erosion–corrosion mechanism. The 3D roughness characterization of the surface indicates that maximum roughness appears in downstream adjacent to the outlet of the 90° elbow. Microscopic surface imaging of eroded elbow surfaces disseminates the presence of corrosion pits on the exit regions of the 90° and 60° elbows, but erosion scars were formed on the entry regions of the 30° elbow. Surface characterization and mass loss results indicated that changing the elbow geometrical configuration from a small angle to wide angle significantly changed the mechanical wear mechanism of the tested elbows. Moreover, the maximum erosive location was identified at the top of the horizontally-oriented elbow for slug flow.
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Wadsworth, Jennifer A., and Roger G. Walker. "Morphology and origin of erosion surfaces in the Cardium Formation (Upper Cretaceous, Western Interior Seaway, Alberta) and their implications for rapid sea level fluctuations." Canadian Journal of Earth Sciences 28, no. 10 (October 1, 1991): 1507–20. http://dx.doi.org/10.1139/e91-135.
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The morphology of three basin-wide erosion surfaces has been defined using 7869 resistivity well logs, over an area of about 50 000 km2. The lowest of these, designated E6, is topographically smooth, and has no incised steps or low areas. It cuts into marine mudstones, and indicates either an uninterrupted erosive transgression following a major lowering of relative sea level, or wave scouring of the substrate following a very minor lowering of sea level. Erosion surface E6.5 also cuts into marine mudstones, but its overall morphology is less well understood owing to subsequent dissection by surface E7. This surface (E7) is characterized by three strike-parallel linear low areas that die out northwestward. These linear lows are up to 40 km wide, 36 m deep, and have irregular to symmetrical cross-sectional profiles. They cut into, and are filled with, marine mudstones, and their origin is enigmatic. The differences in the morphologies of the surfaces suggest the interplay of several controlling parameters: (i) steady transgression versus transgression interrupted by stillstands; (ii) absolute depth of erosion during transgression, which in turn controls the preservation or erosion of incised river valleys; (iii) wave scouring of substrate in response to minor lowerings of sea level; and (iv) availability of coarse sediment and river gradients steep enough for its transport to the shoreline. The average time span between erosion surfaces is 300 000 – 350 000 years. This timing is hard to explain tectonically, or in terms of global eustacy, suggesting the possibility of glacio-eustatic control of fluctuations in relative sea level.
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Balco, Greg, John O. H. Stone, Maciej G. Sliwinski, and Claire Todd. "Features of the glacial history of the Transantarctic Mountains inferred from cosmogenic 26Al, 10Be and 21Ne concentrations in bedrock surfaces." Antarctic Science 26, no. 6 (November 13, 2014): 708–23. http://dx.doi.org/10.1017/s0954102014000261.
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AbstractThis paper describes measurements of concentrations of cosmogenic 26Al, 10Be and 21Ne in quartz from bedrock surfaces in the Transantarctic Mountains where stratigraphic and geomorphic evidence shows that the surfaces were covered by ice in the past, but were not glacially eroded during periods of ice cover. It then explores to what extent this information can be used to learn about past ice sheet change. First, cosmogenic nuclide concentrations in sandstone bedrock surfaces at two sites in the McMurdo Dry Valleys near 77°S are consistent with an equilibrium between nuclide production and loss by surface erosion and radioactive decay. They are most easily explained by a scenario in which: i) sites more than c. 100 m above the present ice surface were almost never ice-covered and eroded steadily at 0.5–1.5 m Ma-1, and ii) sites near the present ice margin experienced similar erosion rates when ice-free, but have been covered by cold-based, non-erosive glacier ice as much as half of the time during the past several million years. Nuclide concentrations in granite bedrock at a site in the Quartz Hills near 85°S, on the other hand, have not reached production-erosion equilibrium, thus retaining evidence of the time they were first exposed to the cosmic ray flux. Nuclide concentrations at these sites are most easily explained by 4–6 Ma exposure, extremely low erosion rates of 5–10 cm Ma-1 during periods of exposure, and only very short periods of cold-based, non-erosive ice cover.
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Al-Saygh, Assist Prof Ghada D., and Assist Prof Rayia J. Al-Naimi. "Dental Erosion in 10 – 12 Year Old Children in Mosul City." Mustansiria Dental Journal 7, no. 2 (January 25, 2018): 174–84. http://dx.doi.org/10.32828/mdj.v7i2.683.
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The aim of this study was to determine the prevalence of dental erosion among 10-12 year old children in Mosul city, mean erosion in teeth and surfaces, amount ofcarbonated beverages and fruit juice consumed in the sample, and the correlationbetween dental erosion and some variables. Total sample consisted of 400 childrenderived from different primary schools in the city center. Examination was performedaccording to tooth wear index by Smith and Knight 1984 modified by Millword et al1994.Results showed that dental erosion was highly prevalent 74.2% in the sample,increasing with increasing age, with boys showing a higher prevalence in dentalerosion compared to girls with significant difference. Mean erosion scores for primaryteeth were slightly less then permanent teeth, with a significant difference between 10and 12 years of age for both dentitions.Buccal/labial surfaces exhibited more erosion, followed by lingual/palatal andfinally occlusal /incisal surfaces, with boys showing more erosion in all surfaces thangirls. A large proportion of the sample consumed carbonated beverages 3-5 /weekwith boys consuming more than girls as seen in the erosion group, fruit juice was alsolargely consumed by the sample, especially the group that showed erosion. A positivecorrelation was found between erosion, level of father’s education, time of drinking,method, amount of carbonated beverages and fruit juice consumed.Preventive measures are considered to be the only effective course of managementof dental erosion, by reducing intake of carbonated beverages and fruit juice, alsomodification of erosive drinks, medicines and foods may prove to be an acceptablefuture strategy world wide.
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Campbell, Daniel R., Claude Lavoie, and Line Rochefort. "Wind erosion and surface stability in abandoned milled peatlands." Canadian Journal of Soil Science 82, no. 1 (February 1, 2002): 85–95. http://dx.doi.org/10.4141/s00-089.
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Peatlands exploited for their peat by the method of milling are poorly recolonized by plants after the cessation of extraction activities, in part due to unstable peat substrates. Wind erosion has been suspected to play a role in this instability. Four studies were conducted to investigate the role of wind erosion on abandoned milled peatlands. A wind tunnel experiment was performed to evaluate the erodibility of dry, loose peat as a function of its degree of decomposition. A second wind tunnel experiment was conducted to determine how crusted peats differ in their resistance to erosion as a function of their degree of decomposition, without the input of abraders. Third, wind profiles were measured in milled, revegetated and natural peatlands in southeastern Québec to determine their aerodynamic roughness length. Finally, field measurements were made at three abandoned milled peatlands through two field seasons to characterize substrate stability and particle movement. In the wind tunnel, the erodibility of loose surface peat decreased with increasing decomposition and was predicted by their equivalent diameter to mineral particles 0.84 mm in diameter. However, once surface crusts formed, peats were all resistant to erosion. Surfaces of abandoned milled peatlands were aerodynamically smooth; therefore, exposed surface elements are subject to strong erosive forces during wind events. The greatest subsidence on abandoned milled peatlands occurred in the spring, prior to the surface movement of particles. Erosion during the summer could not be clearly detected. The instability of the peat surface remains a constraint for the restoration of abandoned milled surfaces. Key Words: Peat, cutover peatland, wind erosion, soil crust, roughness length, soil stability
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Nisa, Zaib Un, Lee Kean Chuan, Beh Hoe Guan, Saba Ayub, and Faiz Ahmad. "Anti-Wear and Anti-Erosive Properties of Polymers and Their Hybrid Composites: A Critical Review of Findings and Needs." Nanomaterials 12, no. 13 (June 26, 2022): 2194. http://dx.doi.org/10.3390/nano12132194.
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Erosion caused by the repeated impact of particles on the surface of a substance is a common wear method resulting in the gradual and continual loss of affected objects. It is a crucial problem in several modern industries because the surfaces of various products and materials are frequently subjected to destructively erosive situations. Polymers and their hybrid materials are suitable, in powdered form, for use as coatings in several different applications. This review paper aims to provide extensive information on the erosion behaviors of thermoset and thermoplastic neat resin and their hybrid material composites. Specific attention is paid to the influence of the properties of selected materials and to impingement parameters such as the incident angle of the erodent, the impact velocity of the erodent, the nature of the erodent, and the erosion mechanism. The review further extends the information available about the erosion techniques and numerical simulation methods used for wear studies of surfaces. An investigation was carried out to allow researchers to explore the available selection of materials and methods in terms of the conditions and parameters necessary to meet current and future needs and challenges, in technologically advanced industries, relating to the protection of surfaces. During the review, which was conducted on the findings in the literature of the past fifty years, it was noted that the thermoplastic nature of composites is a key component in determining their anti-wear properties; moreover, composites with lower glass transition, higher ductility, and greater crystallinity provide better protection against erosion in advanced surface applications.
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Krawczyk, Janusz, Michał Bembenek, Łukasz Frocisz, Tomasz Śleboda, and Marek Paćko. "The Effect of Sandblasting on Properties and Structures of the DC03/1.0347, DC04/1.0338, DC05/1.0312, and DD14/1.0389 Steels for Deep Drawing." Materials 14, no. 13 (June 25, 2021): 3540. http://dx.doi.org/10.3390/ma14133540.
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The erosion phenomenon has a significant influence on many metallic materials used in numerous industrial sectors. In this paper, we present the results of an analysis of the influence of abrasive impact erosion on surface and properties of DC03/1.0347, DC04/1.0338, DC05/1.0312, and DD14/1.0389 deep drawing steels. The chemical composition, static tensile tests, hardness tests, drawability tests, erosion tests, microstructure analysis, surface roughness, and hardness of the plates were investigated. The wear mechanisms and wear behavior of the investigated steels were also discussed. The results obtained in this study allowed the assessment of the microstructural changes in deep drawing steels under the influence of intense erosive impact. The obtained results indicate that the erosive impact may cause a significant grain refinement of the microstructure of the surfaces of the investigated materials. Moreover, large amounts of heat released during erosive impact may cause the material phase changes. This research expands the knowledge on specific mechanisms taking place during sandblasting and their influence on the properties of deep drawing steels and their wear behavior.
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Hara, A. T., M. Ando, C. González-Cabezas, J. A. Cury, M. C. Serra, and D. T. Zero. "Protective Effect of the Dental Pellicle against Erosive Challenges in situ." Journal of Dental Research 85, no. 7 (July 2006): 612–16. http://dx.doi.org/10.1177/154405910608500706.
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The acquired dental pellicle helps prevent erosion, but the protection level is unknown. This in situ study tested whether a two-hour pellicle protects against different erosive challenges by orange juice. Subjects wore palatal appliances loaded with either enamel or dentin specimens. Pellicle was allowed to form, or not (control), on the surfaces of the specimens intra-orally for 2 hrs before the erosive challenges of 0 (control), 10, 20, and 30 minutes’ duration. Specimens were randomly removed from the appliances after each challenge. Percentage of surface microhardness change (%SMC) was determined for the enamel specimens, and that of mineral loss and lesion depth for the dentin specimens. Enamel specimens with the pellicle showed a significantly lower %SMC, only after the 10-minute challenge. No protection was found for dentin. It was concluded that the acquired pellicle reduced dental erosion, but that this effect was limited to the less severe erosive challenge on enamel surfaces.
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GONDIM, Brenna Louise Cavalcanti, Isabella Cavalcante MEDEIROS, Bruna Palmeira COSTA, Hugo Lemes CARLO, Rogério Lacerda dos SANTOS, and Fabíola Galbiatti de CARVALHO. "Effects of erosive challenge on the morphology and surface properties of luting cements." Revista de Odontologia da UNESP 45, no. 2 (March 15, 2016): 103–9. http://dx.doi.org/10.1590/1807-2577.022315.
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Abstract Introduction Few studies investigated the surface properties of luting cements after erosive challenge. Objective To evaluate the surface roughness (Ra), Vickers hardness (VHN) and morphology of 4 luting cements after erosive challenge. Material and method Twenty specimens of each cement were prepared (4×2mm) and divided into experimental (erosive challenge) and control (artificial saliva) groups (n=10): Rely X U200 (U200); Rely X ARC (ARC); Ketac Cem Easy Mix (Ketac) and Zinc phosphate (ZnP). The erosive challenge was performed by four daily erosive cycles (90s) in a cola drink and 2 h in artificial saliva over 7 days. Ra and VHN readings were performed before and after erosion. The percentage of hardness loss (%VHN) was obtained after erosion. The surface morphology was analyzed by scanning electron microscopy (SEM). ANOVA, Tukey and Student-T tests were used (α=0.05). Result After erosion, all luting cements had increase in Ra values and U200 and ZnP groups had the highest %VHN. After saliva immersion, only U200 and ZnP groups had significant increases in Ra values and there were no significant differences among the groups in %VHN. SEM analysis showed that Ketac and ZnP groups had rough and porous surfaces, and U200 group had higher resin matrix degradation than ARC group. Conclusion Erosive challenge with a cola drink affected the surface properties of all luting cements.
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Lehmann, Benjamin, Frédéric Herman, Pierre G. Valla, Georgina E. King, Rabiul H. Biswas, Susan Ivy-Ochs, Olivia Steinemann, and Marcus Christl. "Postglacial erosion of bedrock surfaces and deglaciation timing: New insights from the Mont Blanc massif (western Alps)." Geology 48, no. 2 (November 22, 2019): 139–44. http://dx.doi.org/10.1130/g46585.1.
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Abstract Since the Last Glacial Maximum, ∼20 k.y. ago, Alpine glaciers have retreated and thinned. This transition exposed bare bedrock surfaces that could then be eroded by a combination of debuttressing or local frost cracking and weathering. Quantification of the respective contributions of these processes is necessary to understand the links between long-term climate and erosion in mountains. Here, we quantified the erosion histories of postglacial exposed bedrock in glacial valleys. Combining optically stimulated luminescence and terrestrial cosmogenic nuclide (TCN) surface exposure dating, we estimated the erosion rate of bedrock surfaces at time scales from 101 to 104 yr. Bedrock surfaces sampled from the flanks of the Mer de Glace (Mont Blanc massif, European Alps) revealed erosion rates that vary from 3.5 ± 1.2 ⋅ 10−3 mm/yr to 4.3 ± 0.6 mm/yr over ∼500 m of elevation, with a negative correlation between erosion rate and elevation. The observed spatial variation in erosion rates, and their high values, reflect morphometric (elevation and surface slope) and climatic (temperature and snow cover) controls. Furthermore, the derived erosion rates can be used to correct the timing of deglaciation based on TCN data, potentially suggesting very rapid ice thinning during the Gschnitz stadial.
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Ebert, Karin. "GIS analyses of ice-sheet erosional impacts on the exposed shield of Baffin Island, eastern Canadian Arctic." Canadian Journal of Earth Sciences 52, no. 11 (November 2015): 966–79. http://dx.doi.org/10.1139/cjes-2015-0063.
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The erosional impacts of former ice sheets on the low-relief bedrock surfaces of Northern Hemisphere shields are not well understood. This paper assesses the variable impacts of glacial erosion on a portion of Baffin Island, eastern Canadian Arctic, between 68° and 72°N and 66° and 80°W. This tilted shield block was covered repeatedly by the Laurentide Ice Sheet during the late Cenozoic. The impact of ice-sheet erosion is examined with GIS analyses using two geomorphic parameters: lake density and terrain ruggedness. The resulting patterns generally conform to published data from other remote sensing studies, geological observations, cosmogenic exposure ages, and the distribution of the chemical index of alteration for tills. Lake density and terrain ruggedness are thereby demonstrated to be useful quantitative indicators of variable ice-sheet erosional impacts across Baffin Island. Ice-sheet erosion was most effective in the lower western parts of the lowlands, in a west–east-oriented band at around 350–400 m a.s.l., and in fjord-onset zones in the uplifted eastern region. Above the 350–400 m a.s.l. band and between the fjord-onset zones, ice-sheet erosion was not sufficient to create extensive ice-roughened or streamlined bedrock surfaces. The exception — where lake density and terrain ruggedness indicate that ice-sheet erosion had a scouring effect all across the study area — was in an area from Foxe Basin to Home Bay with elevations <400 m a.s.l. These morphological contrasts link to former ice-sheet basal thermal regimes during the Pleistocene. The zone of low glacial erosion surrounding the cold-based Barnes Ice Cap probably represents the ice cap’s greater extent during successive Pleistocene cold stages. Inter-fjord plateaus with few ice-sheet bedforms remained cold-based throughout multiple Pleistocene glaciations. In contrast, zones of high lake density and high terrain ruggedness are a result of the repeated development of fast-flowing, erosive ice in warm-based zones beneath the Laurentide Ice Sheet. These zones are linked to greater ice thickness over western lowland Baffin Island. However, adjacent lowland surfaces with similar elevations of non-eroded, weakly eroded, and ice-scoured shield bedrock indicate that—even in areas of high lake density and terrain ruggedness—the total depth of ice sheet erosion did not exceed 50 m.
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Lertvijitpun, Vasin, and Pisak Lertvijitpun. "Solid Particle Erosion Resistance of Thermal Sprayed Nickel Alloy Coating." Key Engineering Materials 751 (August 2017): 88–95. http://dx.doi.org/10.4028/www.scientific.net/kem.751.88.
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Solid particle erosion on surface of material effects on life time for them such as the turbine brade, boiler tube and chemical processing equipments. Thermal spray is one of various technique which used for the repairing or building up new surface. The objective of this experiment is to study the influence of thermal spray Ni-Si-B coating parameters on the solid particle erosion resistance at room temperature. The coating parameters were the distances between coating nozzle and the substrate of 10, 15, and 20 mm and travel speeds of 1.0 and 1.5 mm s-1 respectively, leading to the difference of heat inputs. The hardness of coating surfaces was measured by Vickers hardness. The microstructure of coating surfaces was examined by using an optical microscope (OM) and scanning electron microscope (SEM). Moreover, solid particle erosion resistance of coating surfaces was investigated on the erosion test rig at room temperature. Erosion rates of specimens were assessed by the calculation of weight loss which measured using an electronic balance (0.1 mg resolution). The relationship between erosion resistance and hardness was studied coincide with the microstructure examination. According to the erosion resistance evaluation, it was found that an erosion rate of coating depended on the coating condition. Finally, wear scar morphology on the top of an eroded surface and cross-section area was observed by SEM. However, the coating parameters played an important role in the erosion resistance. The microstructure of coating concerned with coating parameters was further discussed with the erosion behavior in this research.
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Bayrak, Sule, Nuray Tuloglu, Huseyin Bicer, and Emine Sen Tunc. "Effect of Fluoride Varnish Containing CPP-ACP on Preventing Enamel Erosion." Scanning 2017 (2017): 1–7. http://dx.doi.org/10.1155/2017/1897825.
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This study aimed to investigate the effect of a fluoride varnish with added casein phosphopeptide-amorphous calcium phosphate treatment on the prevention of enamel erosion, and it compared the results with those of other fluoride varnishes. Fifty enamel specimens obtained from bovine incisors were randomly divided into five groups (n=10) based on the type of surface pretreatment used: intact enamel (Group 1); intact enamel+erosive cycles (Group 2); intact enamel+MI varnish+erosive cycles (Group 3); intact enamel+Clinpro White varnish+erosive cycles (Group 4); and intact enamel+Duraphat varnish+erosive cycles (Group 5). The specimens were subjected to erosive cycles for five days. The surface roughness was evaluated using atomic force microscopy. The results were statistically analyzed using one-way ANOVA and Tukey’s tests. Group 1 had the smoothest surfaces. After the erosive cycles, the greatest surface roughness values were observed in Group 2, followed by Groups 5, 4, and 3, respectively. Statistically significant differences were observed among all groups (p<0.05). The application of fluoride varnishes had some positive effects on preventing enamel erosion; however, the most effective agent was fluoride varnish with added casein phosphopeptide-amorphous calcium phosphate.
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Sharpe, David, André Pugin, Susan Pullan, and John Shaw. "Regional unconformities and the sedimentary architecture of the Oak Ridges Moraine area, southern Ontario." Canadian Journal of Earth Sciences 41, no. 2 (February 1, 2004): 183–98. http://dx.doi.org/10.1139/e04-001.
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Seismic stratigraphy, geometry, and sediment facies within the Oak Ridges Moraine (ORM) area of Ontario record major structural elements and surfaces of the Quaternary sedimentary sequence. The derived stratigraphic architecture can be used to identify the key elements of a regional erosional surface, represented by an unconformity in the subsurface, and associated overlying channel sediments. The erosional surface unconformity forms a distinct time datum in the Quaternary sequence, which provides an important aid to lithostratigraphic correlation. The architecture also gives improved understanding of the effects of erosion on the late-glacial landscape. The surfaces of erosional drumlins and intervening troughs, and the beds and banks of meltwater channels in the ORM area, define the regional unconformity, highlighted by seismic profiles linked to continuously cored boreholes. These features are attributed to regional-scale, subglacial meltwater flow events. The sculpted surfaces, which are analogous to water-eroded forms, the presence of boulder lags and coarse-grained deposits on the regional erosional surface, and the channels with undulating profiles provide the vital supporting evidence for a meltwater interpretation. The inter-regional extent of the unconformity is inferred from the coherence of regional paleoflows and the extent of drumlinized uplands, tunnel channels, and scoured bedrock terrain across ~75% of the landscape from the ORM area east and south to the Finger Lakes, New York. The implied magnitude of erosion suggests a pressing need for directed sedimentological study in those ocean basins that were probable depositional sites for flood deposits.
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Kotarska, Aleksandra. "The Laser Alloying Process of Ductile Cast Iron Surface with Titanium." Metals 11, no. 2 (February 6, 2021): 282. http://dx.doi.org/10.3390/met11020282.
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The article presents the results of the laser alloying process of ductile cast iron EN-GJS 350-22 surface with titanium. The laser alloying process was conducted on 2 kW high power diode laser (HPDDL) Rofin Sinar DL02 with rectangular focus and uniform power density distribution in the focus axis. The laser alloying was conducted with constant laser beam power and processing speed with titanium powder feed rate variation. The tests of the produced surface layers included macrostructure and microstructure observations, X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS) analysis, Vickers hardness, and solid particle erosion according to ASTM G76-04 standard. To assess the erosion mechanism, SEM observations of worn surfaces after erosive test were carried out. As a result of laser alloying of a ductile cast iron surface, the in situ metal-matrix composite structure was formed with TiC reinforcing particles. The microstructure change resulted in the increase of surface layers hardness and erosion resistance in comparison to the base material.
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Bordeasu, Ilare, Adrian Circiumaru, Mircea O. Popoviciu, Iosif Lazar, Rodica Badarau, and Ioan Groza. "Cavitation Erosion Behavior on Thin Films of Polymer Blends Deposited Over Bronze Surfaces." Materiale Plastice 55, no. 3 (September 30, 2018): 286–90. http://dx.doi.org/10.37358/mp.18.3.5014.
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The composite materials with polymeric matrix represent a great realization of chemical engineering. Their applications in all the industrial fields are dictated by their chemical, physical and mechanical properties. In the last 50 years the polymeric composite materials received a large use in the protection and repair work of the surfaces in contact with fluid currents of various natures. The scientific researches followed by the industrial use, show that the polymere films with certain composition and properties have an excellent behavior to chemical, abrasive and cavitation erosions. Because the most stressed machine details subjected to cavitation erosions are the blades, runners and impellers of hydraulic machines as well as the ship propellers, researchers are looking for the best polymers to increase the running time, or for the use in covering the zones with shallow erosions, during the repair work. In this direction is oriented also the present research, performed in the Cavitation Laboratory of the Timisoara Polytechnic University. The obtained cavitation erosion for specimens covered with different polymere films is compared with those realized in identical conditions, but for specimens without protection films. The results show that the films assure some increase in the resistance to cavitation erosion but the tested polymer layers have reduced adherence on the metal surface.
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Abouelresh, Mohamed O. "Multiscale Erosion Surfaces of the Organic-Rich Barnett Shale, Fort Worth Basin, USA." Journal of Geological Research 2013 (June 24, 2013): 1–16. http://dx.doi.org/10.1155/2013/759395.
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The high frequency and diversity of erosion surfaces throughout the Barnett Shale give a unique view into the short-duration stratigraphic intervals that were previously much more difficult to detect in such fine-grained rocks. The erosion surfaces in Barnett Shale exhibit variable relief (5.08–61 mm) which commonly consists of shelly laminae, shale rip-up clasts, reworked mud intraclasts, phosphatic pellets, and/or diagenetic minerals (dolomite and pyrite) mostly with clay-rich mudstone groundmass. Several factors control this lithological variation, including the energy conditions, rate of relative sea-level fluctuation, rate of sedimentation, sediment influx, and the lithofacies type of the underlying as well as the overlying beds. The erosional features and their associated surfaces make them serve at least in part as boundaries between different genetic types of deposits but with different scales according to their dependence on base level and/or sediment supply. Accordingly, the studied erosion surfaces of the Barnett Shale can be grouped into three different scales of sequence stratigraphic surfaces: sequence-scale surfaces, parasequence-scale surfaces, and within trend-scale surfaces.
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Fortini, Annalisa, Alessio Suman, Alessandro Vulpio, Mattia Merlin, and Michele Pinelli. "Microstructural and Erosive Wear Characteristics of a High Chromium Cast Iron." Coatings 11, no. 5 (April 22, 2021): 490. http://dx.doi.org/10.3390/coatings11050490.
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Surface material loss due to erosive wear is responsible for the increased cost of maintenance and downtime in industries. Hence, hardfacing is one of the most valuable and effective techniques employed to improve the wear resistance of heavy-duty components. The present paper investigates the microstructural and erosive wear characteristics of a hypereutectic high-chromium cast iron, considering the erosion resistance, resulting from the impact of micro-sized particles, of both as-received and heat-treated conditions. Micro-sized particles involve the erosion-resistant characteristics of carbide and matrix, contemporary. Due to this, the enhancement of the matrix strength could improve the mechanical support to withstand cracking deformation and spalling. Accordingly, the effect of a destabilization heat treatment on the microstructure was firstly investigated by hardness tests, X-ray diffraction analyses, optical and scanning electron microscopy. Specifically designed erosive tests were carried out using a raw meal powder at an impingement angle of 90°. The resulting superior wear resistance of the heat-treated samples was relayed on the improved matrix microstructure: consistent with the observed eroded surfaces, the reduced matrix/carbides hardness difference of the heat-treated material is pivotal in enhancing the erosion resistance of the hardfacing. The present results contribute to a better understanding of the microstructure–property relationships concerning the erosive wear resistance.
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Isomoto, Yoshinori. "Erosion and Erosion-Corrosion." Zairyo-to-Kankyo 57, no. 1 (2008): 15–21. http://dx.doi.org/10.3323/jcorr.57.15.
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Venugopal, V., T. Basu, S. Garg, J. K. Tripathi, S. Chandramohan, P. Das, T. K. Chini, S. R. Bhattacharyya, D. Kanjilal, and T. Som. "Ion erosion induced nanostructured semiconductor surfaces." International Journal of Nanotechnology 9, no. 10/11/12 (2012): 1007. http://dx.doi.org/10.1504/ijnt.2012.049462.
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Han, Zhiwu, Wei Yin, Junqiu Zhang, Jialian Jiang, Shichao Niu, and Luquan Ren. "Erosion-Resistant Surfaces Inspired by Tamarisk." Journal of Bionic Engineering 10, no. 4 (December 2013): 479–87. http://dx.doi.org/10.1016/s1672-6529(13)60238-3.
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Dhillon, Prabhjeet Kaur, and Subhendu Sarkar. "Erosion dynamics of faceted pyramidal surfaces." Current Applied Physics 16, no. 9 (September 2016): 956–62. http://dx.doi.org/10.1016/j.cap.2016.05.017.
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Rawers, J., and J. Tylczak. "Fractal Characterization of Wear-Erosion Surfaces." Journal of Materials Engineering and Performance 8, no. 6 (December 1, 1999): 669–76. http://dx.doi.org/10.1361/105994999770346431.
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Han, Zhi Wu, Ming Kang Yang, Wei Yin, and Jun Qiu Zhang. "Biomimetic Design and Manufacturing of Anti-Erosion Functional Surfaces Inspired from Desert Scorpion." Advances in Science and Technology 100 (October 2016): 187–96. http://dx.doi.org/10.4028/www.scientific.net/ast.100.187.
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Sand erosion is a phenomenon that solid particles impinging to a wall cause serious mechanical damages to its surface. It's tough to be a machine in the desert: particles of dirt and sand work their way into moving parts, where they abrade helicopter propellers, airplane rotor blades, pipes and other equipments. However, the desert scorpion (Androctonus australis) live their entire lives subjected to blowing sand, yet they never appear to be eroded. In this study, the anti–erosion characteristic rules of the scorpion surfaces under aerodynamics effect of gas/solid mixed media were studied. Biomimetic linear–cutted surfaces consisting of an array of three types of grooves, square–type, V–type and U–type, were designed and investigated to quantify their erosion wear resistance properties. A smooth surface sample was fabricated for comparison. The ANSYS-Fluent simulation of biomimetic models showed that the V-type groove sample, inspired by the desert organism's surface with different morphologies, exhibited the best erosion resistance. It also indicated the anti-erosion property of biomimetic samples could be attributed to the rotating flow in the grooves that reduces the impact speed of particles. The synchronized erosion test confirmed the conclusions. Furthermore, an application exploring of bionic blades on a centrifugal fan was conducted. The blades with optimum parameters could effectively improve anti-erosion property by 29%. We envision that more opportunities for biomimetic application in improving the anti–erosion performance of parts that work under dirt and sand particle environment will be proposed.
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Chen, Yong, and Jiguo Zhang. "High-Speed Erosion Behavior of Hydrophobic Micro/Nanostructured Titanium Surfaces." Nanomaterials 12, no. 5 (March 7, 2022): 880. http://dx.doi.org/10.3390/nano12050880.
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Ice accretion on aircrafts or their engines can cause serious problems and even accidents. Traditional anti-icing and de-icing systems reduce engine efficiency, which can be improved by the use of hydrophobic/icephobic coatings or surfaces that reduce the amount of bleed air or electric power needed. These hydrophobic/icephobic coatings or surfaces are eroded by high-speed air flow, water droplets, ice crystals, sand, and volcanic ash, resulting in the degradation, material loss, or deterioration of the coating’s waterproof and anti-icing properties. Thus, the durability of hydrophobic micro/nanostructured surfaces is a major concern in aircraft applications. However, the mechanism responsible for material loss in hydrophobic micro/nanostructured surfaces resulting from high-speed erosion remains unclear. In this paper, hydrophobic titanium alloy surfaces with cubic pit arrays are fabricated by photoetching and tested using a high-speed sand erosion rig. Under the same impact conditions, the erosion rates of the micro/nanostructured titanium surfaces were similar to those of smooth titanium alloy, implying that the hydrophobic surface fabricated on the bulk material had erosion-resistant capabilities. The material loss mechanisms of the micro/nanostructures under different impact angles were compared, providing useful information for the future optimization of micro/nanostructures with the goal of improved erosion resistance.
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Fabritius-Vilpoux, Kathia, Joachim Enax, David Mayweg, Frederic Meyer, Michael Herbig, Dierk Raabe, and Helge-Otto Fabritius. "Ultrastructural changes of bovine tooth surfaces under erosion in presence of biomimetic hydroxyapatite." Bioinspired, Biomimetic and Nanobiomaterials 10, no. 4 (December 1, 2021): 132–45. http://dx.doi.org/10.1680/jbibn.21.00017.
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Enamel and dentin are susceptible to acids from food sources leading to dental erosion, a global problem affecting millions of individuals. Particulate hydroxyapatite (HAP) on the tooth surface can influence the effects of acid attacks. Standardized bovine enamel and dentin samples with artificial saliva are used in an in vitro cyclic demineralization–remineralization protocol to analyze the structural changes experienced by tooth surfaces using high-resolution scanning electron microscopy and to evaluate the potential of a HAP-based oral care gel in the protection of teeth from erosive attacks. The interfaces between HAP particle and enamel HAP crystallites are investigated using focused ion beam preparation and transmission electron microscopy. The results show that erosion with phosphoric acid severely affects enamel crystallites and dentin tubules, while artificial saliva leads to remineralization effects. The HAP-gel forms a microscopic layer on both enamel and dentin surfaces. Upon acid exposure, this layer is sacrificed before the native tooth tissues are affected, leading to significantly lower degrees of demineralization compared to the controls. This demonstrates that the use of particulate HAP as a biomaterial in oral care formulations can help protect enamel and dentin surfaces from erosive attacks during meals using a simple and effective protection principle.
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Caneppele, Taciana Marco Ferraz, Raffaela Di Iorio Jeronymo, Rebeca Di Nicoló, Maria Amélia Máximo de Araújo, and Luís Eduardo Silva Soares. "In Vitro assessment of dentin erosion after immersion in acidic beverages: surface profile analysis and energy-dispersive X-ray fluorescence spectrometry study." Brazilian Dental Journal 23, no. 4 (2012): 373–78. http://dx.doi.org/10.1590/s0103-64402012000400011.
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The aim of this study was to investigate the effects of some acidic drinks on dentin erosion, using methods of surface profile (SP) analysis and energy-dispersive X-ray fluorescence spectrometry (EDXRF). One hundred standardized dentin slabs obtained from bovine incisor roots were used. Dentin slabs measuring 5x5 mm were ground flat, polished and half of each specimen surface was protected with nail polish. For 60 min, the dentin surfaces were immersed in 50 mL of 5 different drinks (Gatorade®, Del Valle Mais orange juice®, Coca-Cola®, Red Bull® and white wine), 20 blocks in each drink. The pH of each beverage was measured. After the erosive challenge, the nail polish was removed and SP was analyzed. The mineral concentration of dentin surfaces was determined by means of EDXRF. Data were analyzed statistically by ANOVA and Tukey's test (α=0.05). SP analysis showed that Red-Bull had the highest erosive potential (p<0.05). EDXRF results exhibited a decrease in phosphate in the groups immersed in Red-Bull, orange juice and white wine (p<0.05), and no significant difference in calcium content between the reference surface and eroded surface. In conclusion, this study demonstrated that all studied beverages promoted erosion on root dentin and Red Bull had the highest erosive potential. There was no correlation between pH of beverages and their erosive potential and only the P content changed after erosive challenge.
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Stark, Colin P., and Gavin J. Stark. "The direction of landscape erosion." Earth Surface Dynamics 10, no. 3 (May 3, 2022): 383–419. http://dx.doi.org/10.5194/esurf-10-383-2022.
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Abstract. The rate of erosion of a landscape depends largely on local gradient and material fluxes. Since both quantities are functions of the shape of the catchment surface, this dependence constitutes a mathematical straitjacket, in the sense that – subject to simplifying assumptions about the erosion process, and absent variations in external forcing and erodibility – the rate of change of surface geometry is solely a function of surface geometry. Here we demonstrate how to use this geometric self-constraint to convert a gradient-dependent erosion model into its equivalent Hamiltonian, and explore the implications of having a Hamiltonian description of the erosion process. To achieve this conversion, we recognize that the rate of erosion defines the velocity of surface motion in its orthogonal direction, and we express this rate in its reciprocal form as the surface-normal slowness. By rewriting surface tilt in terms of normal slowness components and deploying a substitution developed in geometric mechanics, we extract what is known as the fundamental metric function of the model phase space; its square is the Hamiltonian. Such a Hamiltonian provides several new ways to solve for the evolution of an erosion surface: here we use it to derive Hamilton's ray-tracing equations, which describe both the velocity of a surface point and the rate of change of the surface-normal slowness at that point. In this context, gradient-dependent erosion involves two distinct directions: (i) the surface-normal direction, which points subvertically downwards, and (ii) the erosion ray direction, which points upstream at a generally small angle to horizontal with a sign controlled by the scaling of erosion with slope. If the model erosion rate scales faster than linearly with gradient, the rays point obliquely upwards, but if erosion scales sublinearly with gradient, the rays point obliquely downwards. This dependence of erosional anisotropy on gradient scaling explains why, as previous studies have shown, model knickpoints behave in two distinct ways depending on the gradient exponent. Analysis of the Hamiltonian shows that the erosion rays carry boundary-condition information upstream, and that they are geodesics, meaning that surface evolution takes the path of least erosion time. Correspondingly, the time it takes for external changes to propagate into and change a landscape is set by the velocity of these rays. The Hamiltonian also reveals that gradient-dependent erosion surfaces have a critical tilt, given by a simple function of the gradient scaling exponent, at which ray-propagation behaviour changes. Channel profiles generated from the non-dimensionalized Hamiltonian have a shape entirely determined by the scaling exponents and by a dimensionless erosion rate expressed as the surface tilt at the downstream boundary.
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Han, Wei, Jingbo Kang, Jie Wang, Guoyi Peng, Lianyuan Li, and Min Su. "Erosion estimation of guide vane end clearance in hydraulic turbines with sediment water flow." Modern Physics Letters B 32, no. 10 (April 10, 2018): 1850100. http://dx.doi.org/10.1142/s0217984918501002.
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The end surface of guide vane or head cover is one of the most serious parts of sediment erosion for high-head hydraulic turbines. In order to investigate the relationship between erosion depth of wall surface and the characteristic parameter of erosion, an estimative method including a simplified flow model and a modificatory erosion calculative function is proposed in this paper. The flow between the end surfaces of guide vane and head cover is simplified as a clearance flow around a circular cylinder with a backward facing step. Erosion characteristic parameter of [Formula: see text] is calculated with the mixture model for multiphase flow and the renormalization group (RNG) k–[Formula: see text] turbulence model under the actual working conditions, based on which, erosion depths of guide vane and head cover end surfaces are estimated with a modification of erosion coefficient K. The estimation results agree well with the actual situation. It is shown that the estimative method is reasonable for erosion prediction of guide vane and can provide a significant reference to determine the optimal maintenance cycle for hydraulic turbine in the future.
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Wang, Zhiguo, Jinpeng Song, Tianyi Wang, Huixin Wang, and Qinghua Wang. "Laser Texturing for Superwetting Titanium Alloy and Investigation of Its Erosion Resistance." Coatings 11, no. 12 (December 16, 2021): 1547. http://dx.doi.org/10.3390/coatings11121547.
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Erosion of materials is one of the major causes that lead to the malfunction of equipment and facilities, and surface texturing can be a solution for enhancement of erosion resistance. In this work, superwetting (superhydrophilic/superhydrophobic) titanium (Ti) alloy surface with periodic microstructure was prepared by a facile laser-based surface texturing approach which combines laser surface texturing and low-temperature annealing. The effect of laser-induced surface texture and wettability on the erosion resistance of the laser textured surface was studied. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were used to analyze the chemical surface microstructure and surface on the untreated and laser textured surfaces. The hardness and contact angle of the untreated surface, superhydrophilic surface and superhydrophobic surface were measured by microhardness tester and contact angle goniometer. Using an in-house built erosion experimental setup, the erosion resistance of the untreated surface, superhydrophilic surface and superhydrophobic surface was investigated. The experimental results demonstrate that micro-bumps are formed after laser surface texturing. In the meantime, the surface hardness for the laser textured surface with a step size of 150 μm is increased by 48% under the load of 1.961 N. Compared with the untreated surface, the erosion resistance is increased by 33.9%, 23.8% and 16.1%, respectively, for the superhydrophobic surface. The SEM results show that the untreated surface has large and deep impact pits, while the superhydrophobic surface only has small and shallow impact pits, indicating that the erosion process resulted in less damage to the substrate. The EDS results shows that superhydrophobicity plays a critical role in protecting the substrate from erosion. It is thus believed that the superhydrophobic surface has pronounced effects for improving the hardness and erosion resistance of Ti alloy.
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Beer, Alexander R., James W. Kirchner, and Jens M. Turowski. "Graffiti for science – erosion painting reveals spatially variable erosivity of sediment-laden flows." Earth Surface Dynamics 4, no. 4 (December 15, 2016): 885–94. http://dx.doi.org/10.5194/esurf-4-885-2016.
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Abstract. Spatially distributed detection of bedrock erosion is a long-standing challenge. Here we show how the spatial distribution of surface erosion can be visualized and analysed by observing the erosion of paint from natural bedrock surfaces. If the paint is evenly applied, it creates a surface with relatively uniform erodibility, such that spatial variability in the erosion of the paint reflects variations in the erosivity of the flow and its entrained sediment. In a proof-of-concept study, this approach provided direct visual verification that sediment impacts were focused on upstream-facing surfaces in a natural bedrock gorge. Further, erosion painting demonstrated strong cross-stream variations in bedrock erosion, even in the relatively narrow (5 m wide) gorge that we studied. The left side of the gorge experienced high sediment throughput with abundant lateral erosion on the painted wall up to 80 cm above the bed, but the right side of the gorge only showed a narrow erosion band 15–40 cm above the bed, likely due to deposited sediment shielding the lower part of the wall. This erosion pattern therefore reveals spatial stream bed aggradation that occurs during flood events in this channel. The erosion painting method provides a simple technique for mapping sediment impact intensities and qualitatively observing spatially distributed erosion in bedrock stream reaches. It can potentially find wide application in both laboratory and field studies.
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Bai, Xupeng, Yongming Yao, Zhiwu Han, Junqiu Zhang, and Shuaijun Zhang. "Study of Solid Particle Erosion on Helicopter Rotor Blades Surfaces." Applied Sciences 10, no. 3 (February 3, 2020): 977. http://dx.doi.org/10.3390/app10030977.
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In this study, titanium alloy (Ti-4Al-1.5Mn), magnesium alloy (Mg-Li9-A3-Zn3), or aluminum alloy (Al7075-T6) were used to construct the shell model of helicopter rotor blade to study the solid particle erosion of helicopter rotor blades. The erosion resistance of the three materials at different angles of attack (6°, 3°, or 0°) and particle collision speeds (70, 150, or 220 m/s) was examined using the finite volume method, the discrete phase method, and erosion models. In addition, the leading edge of the helicopter blades was coated with two types of bionic anti-erosion coating layers (V- and VC-type), in an attempt to improve erosion resistance at the angles of attack and particle collision speeds given above. The results showed that Ti-4Al-1.5Mn had the best erosion resistance at high speed, followed by Al7075-T6 and Mg-Li9-A3-Zn3. The angle of attack appeared to affect only the surface area of the blade erosion, while the erosion rate was not affected. Finally, the results of this article showed that the V-type bionic coating had better erosion resistance than the VC-type coating at the same impact speeds. The angle of attack did not have a significant effect on the erosion rate of the bionic coating.
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Petlušová, Viera, Peter Petluš, Michal Ševčík, and Juraj Hreško. "The Importance of Environmental Factors for the Development of Water Erosion of Soil in Agricultural Land: The Southern Part of Hronská Pahorkatina Hill Land, Slovakia." Agronomy 11, no. 6 (June 18, 2021): 1234. http://dx.doi.org/10.3390/agronomy11061234.
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The water erosion research was carried out in the lowland type of hilly landscape. The aim was to monitor and evaluate the importance of environmental factors (steepness of slope, relief shapes, aspect, slope length, combination slope length (L) and slope (S)—LS factor, types of land use changes) for the development of water erosion. We focused on the identification of areas threatened by erosion by interpreting aerial photographs from several time periods. This was followed by verification of erosion using soil probes. We identified 408.44 ha of areas affected by erosion, and measured the depth of soil and “A” horizons thickness. The environmental factors were modeled in geographical information systems by tools for spatially oriented data. Subsequently, the influence and significance of individual environmental factors were compared, and the probability of erosion was statistically estimated. The decisive factors in the formation of erosive surfaces are the LS factor and the slope. We also consider the factor of the relief shape to be important. The shape did not appear to be very significant as a separately evaluated factor, but all convex parts correlate with the identified erosion surfaces. The susceptibility of erosion related to the aspect of the slopes to the cardinal directions has not been confirmed. Types of land use changes with the most significant relation of erosion were confirmed in areas of strong intensification. We confirmed the importance of factors and land use for the development of erosion processes.
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Tyfour, Wa’il R., Mohammed T. Hayajneh, and Jawad M. Qasaymeh. "On the models of erosive wear of ductile materials." Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications 232, no. 11 (June 22, 2016): 931–38. http://dx.doi.org/10.1177/1464420716656479.
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As the mechanism by which material is lost from ductile surfaces during solid particle erosion is still a matter of scientific debate, the work presented in this paper is aimed at trying to shed more light on the mechanism by which material is detached from ductile surfaces during solid particle erosion. Moreover, validating some of the most widely accepted models that predict erosive wear rate will form part of the paper. A specially designed test rig was used to facilitate test condition of an extensive experimental program. Results of the test program showed that plastic strain accumulation is largely responsible for material loss from ductile surfaces, even at cute impact angles. The key to this finding is the drop of erosive wear upon impact angle reversal indicates. It has been shown that none of the most widely accepted models of erosive wear could explain the result obtained under condition of impact angle reversal.
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Okada, Tsunenori, Yoshiro Iwai, and Yukio Hosokawa. "Comparison of Surface Damage Caused by Sliding Wear and Cavitation Erosion on Mechanical Face Seals." Journal of Tribology 107, no. 2 (April 1, 1985): 200–205. http://dx.doi.org/10.1115/1.3261020.
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To clarify the dangerous surface damage in mechanical seals, both sliding wear and vibratory cavitation erosion tests were performed on sintered carbon materials. The differences in damage between cavitation erosion and sliding wear were investigated through observation of surface topographies and volume losses. Roughness, Ra, of worn surface is rather small, about 1 μm in the worst case, and is independent of the worn depth. In cavitation erosion, however, Ra of eroded surface increases rapidly and thereafter attains a large steady value (3.6 μm- 11 μm for various carbon materials) with increasing eroded depth regardless of the cavitation intensity. The sliding surfaces of actual operating mechanical seals were compared with our test results and thus it was concluded that the severe damage in the mechanical seals is caused by the concentrated repetition of cavitation erosion. Furthermore, the wear and cavitation erosion resistance were compared among the various carbon seal materials. From these results, it has become clear that the cavitation erosion test is important to find out the quality of mechanical seal materials.
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Vitvitskyi, Yaroslav. "INFLUENCE OF THE RELIEF ON THE EROSION DEGRADATION CHERNOZEMS OF THE PRYDNISTERSKA UPLAND." PROBLEMS OF GEOMORPHOLOGY AND PALEOGEOGRAPHY OF THE UKRANIAN CARPATHIANS AND ADJACENT AREAS, no. 11(01) (January 13, 2021): 280–93. http://dx.doi.org/10.30970/gpc.2020.1.3213.
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This publication deals with the erosive degradation of chernozem soils in the context of the the Prydnisterska Upland relief. The structure of the soil coverage of the studied area is represented by two subzonal subtypes of chernozem soils. Precisely: typical and podzolic, with a total area of 4 060 km2 (62% of the territory). The major part of these are flat interfluve: flat interfluve, wavy interfluves dissected by beam and valley forms, high fragmentary terrace complexes with insignificant horizontal dismemberment. The background surfaces of the intensity of erosion chernozem soils degradation are slopes of different steepness, exposure and morphometry. With the help of the geoinformational program ArcGIS, the distribution of slopes with the corresponding parameters of steepness and total area is determined. Inclined slopes with the steepness of 1–3° (1 700 km2) are dominant. The area with a steepness of 5° or less is approximately 87% of the total area of chernozem soils. However are of slightly inclined relief with only mere erosion occurant. The steep surfaces expositional distribution indicates the predominance of the southern, southwestern exposure slopes of an average length of 500–1 500 m. The results of the field morphological studies show that in the 5–6° – incline surfaces of inflection areas chernozem podzolic and strongly washed away. The degree of typical chernozem soils erosion is mostly associated with transversely convex and slightly convex slopes. In accordance with the degree of erosion, slightly washed typical chernozem soils formed on the same slopes of 2–3°, medium washed on 3–5°, strongly washed 8° incline. However, on the oblique slopes with an incline of 3–5° of complex shapes, typical chernozem soils the entire humus line is washed away. Particularly critical degree of chernozem soils erosion is observed within the complex slopes of river meanders and beam girder systems. In addition to the listed morphometric parameters of slope surfaces, the development of erosion degradation is influenced by the local unreasonable placement of linear boundaries. Thus, roads laid perpendicularly to river valleys and watersheds or along the plane of individual slopes form artificial bases of erosion, accelerating degradation processes. The formation of natural quarries leads to the active development of linear erosion of regressive nature. Key words: podzolic chernozem; typical chernozem; Prydnisterska Upland; GIS-analysis; erosive degradation; slope morphology; relief.
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Bryan, Rorke B., Ian A. Campbell, and Aaron Yair. "Postglacial geomorphic development of the Dinosaur Provincial Park badlands, Alberta." Canadian Journal of Earth Sciences 24, no. 1 (January 1, 1987): 135–46. http://dx.doi.org/10.1139/e87-011.
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Experimental studies concerning current geomorphic processes and erosion rates in the badlands of Dinosaur Provincial Park, Alberta, have not explained the unusual extent of badland development or prominent nonstructural near-horizontal surfaces that occur in the park. Two of these surfaces result from spillway development associated with Wisconsin deglaciation, and the extent of badland development is associated with major spillway concentration and exposure of highly erodible Cretaceous strata. A third surface is associated with erosion caused by locally generated runoff. All surfaces are blanketed with aeolian sands and silts deposited around 5500 BP, which profoundly affected the hydrology of the area and water and sediment discharge from the badlands to the Red Deer River. Subsequent stripping of the aeolian cover by streams, along with piping and tunnel erosion, has reexposed vulnerable Cretaceous strata and restored the high erosion rates now observed in these badlands.
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Karydas, Christos, Ouiza Bouarour, and Pandi Zdruli. "Mapping Spatio-Temporal Soil Erosion Patterns in the Candelaro River Basin, Italy, Using the G2 Model with Sentinel2 Imagery." Geosciences 10, no. 3 (February 27, 2020): 89. http://dx.doi.org/10.3390/geosciences10030089.
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This study aims at mapping soil erosion caused by water in the Candelaro river basin, Apulia region, Italy, using the G2 erosion model. The G2 model can provide erosion maps and statistical figures at month-time intervals, by applying non data-demanding alternatives for the estimation of all the erosion factors. In the current research, G2 is taking a step further with the introduction of Sentinel2 satellite images for mapping vegetation retention factor on a fine scale; Sentinel2 is a ready-to-use, image product of high quality, freely available by the European Space Agency. Although only three recent cloud-free Sentinel2 images covering Candelaro were found in the archive, new solutions were elaborated to overcome time-gaps. The study in Candelaro resulted in a mean annual erosion rate of 0.87 t ha−1 y−1, while the autumn months were indicated to be the most erosive ones, with average erosion rates reaching a maximum of 0.12 t ha−1 in September. The mixed agricultural-natural patterns revealed to be the riskiest surfaces for most months of the year, while arable land was the most extensive erosive land cover category. The erosion maps will allow competent authorities to support relevant mitigation measures. Furthermore, the study in Candelaro can play the role of a pilot study for the whole Apulia region, where erosion studies are rather limited.
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Bermes, Andrii. "Structural-morphometric analysis of Kremenets Mountains (part 1)." Visnyk of the Lviv University. Series Geography 53 (December 18, 2019): 24–46. http://dx.doi.org/10.30970/vgg.2019.53.10654.
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The geomorphological structure and the morphometric features are characterized, the structural-morphometric constructions of the territory of the Kremenets Mountains are conducted and analyzed. The multi-order maps of the baseline and vertex surfaces, the residual relief, and the local erosion are created with the help of the software called AcrGis. The features of the geomorphological structure and the stage of the relief development are determined. Some regularities in the distribution of the morphometric indicators of the different parts of the Kremenets Mountains are revealed. Twelve morphometric different-genetic and different-order maps are constructed, and the surface of the top, baseline, residual and erosion relief are made and analyzed in accordance with the hypsometric and morphometric characteristics for this analysis. The method of the constructing of the map models for the structural and the morphometric analysis are presented. The comparison of vertices and bases of different order, as well as vertex – basal surfaces are analyzed, which allowed revealing the latest and modern movements of the earth's crust, the quantitative estimation of the amplitude of the vertical movements. The altitude differences in the characteristics of model comparisons are presented. The analysis and the comparison of the models allowed establishing the nature of the latest movements, the ratio of the denudation and the accumulation, the intensity of the erosion processes of the formation of the different stages of the investigated territory. The maps of the apex, basal, residual, erosion relief, which are created, serve as a basis for the comparison of the different top and base surfaces and the single-row top-base surfaces with the linear and the annular tectonic structures (the analysis of the latest tectonogenesis) in the future publications. Key words: basic surface, vertex surface, watershed, erosion network, residual relief, local erosion, morphometric analysis, digital terrain model, watercourses order, neotectonic movements, North-Podillia ledge.
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Faiman, Laurence. "Alkaline erosion of CR 39 polymer surfaces." Radiation Physics and Chemistry 78, no. 1 (January 2009): 69–76. http://dx.doi.org/10.1016/j.radphyschem.2008.06.008.
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Mehine, M., C. Björkas, K. Vörtler, K. Nordlund, and M. I. Airila. "Modelling the erosion of beryllium carbide surfaces." Journal of Nuclear Materials 414, no. 1 (July 2011): 1–7. http://dx.doi.org/10.1016/j.jnucmat.2011.03.022.
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Rubel, Marek. "Plasma-induced erosion of monocrystalline alloy surfaces." Materials Science and Engineering 91 (July 1987): L9—L12. http://dx.doi.org/10.1016/0025-5416(87)90312-0.
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