Articoli di riviste: "Erosion"

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Barnabe, Cheryl, Dominique Toepfer, Hubert Marotte, Ellen-Margrethe Hauge, Andrea Scharmga, Roland Kocijan, Sebastian Kraus et al. "Definition for Rheumatoid Arthritis Erosions Imaged with High Resolution Peripheral Quantitative Computed Tomography and Interreader Reliability for Detection and Measurement". Journal of Rheumatology 43, n. 10 (ottobre 2016): 1935–40. http://dx.doi.org/10.3899/jrheum.160648.

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Objective.High-resolution peripheral quantitative computed tomography (HR-pQCT) sensitively detects erosions in rheumatoid arthritis (RA); however, nonpathological cortical bone disruptions are potentially misclassified as erosive. Our objectives were to set and test a definition for pathologic cortical bone disruptions in RA and to standardize reference landmarks for measuring erosion size.Methods.HR-pQCT images of metacarpophalangeal joints of RA and control subjects were used in an iterative process to achieve consensus on the definition and reference landmarks. Independent readers (n = 11) applied the definition to score 58 joints and measure pathologic erosions in 2 perpendicular multiplanar reformations for their maximum width and depth. Interreader reliability for erosion detection and variability in measurements between readers [root mean square coefficient of variation (RMSCV), intraclass correlation (ICC)] were calculated.Results.Pathologic erosions were defined as cortical breaks extending over a minimum of 2 consecutive slices in perpendicular planes, with underlying trabecular bone loss and a nonlinear shape. Interreader agreement for classifying pathologic erosions was 90.2%, whereas variability for width and depth erosion assessment was observed (RMSCV perpendicular width 12.3%, axial width 20.6%, perpendicular depth 24.0%, axial depth 22.2%; ICC perpendicular width 0.206, axial width 0.665, axial depth 0.871, perpendicular depth 0.783). Mean erosion width was 1.84 mm (range 0.16–8.90) and mean depth was 1.86 mm (range 0.30–8.00).Conclusion.We propose a new definition for erosions visualized with HR-pQCT imaging. Interreader reliability for erosion detection is good, but further refinement of selection of landmarks for erosion size measurement, or automated volumetric methods, will be pursued.

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Søvik, Jenny B., Alexandre R. Vieira, A. B. Tveit e Aida Mulic. "Enamel Formation Genes Associated with Dental Erosive Wear". Caries Research 49, n. 3 (2015): 236–42. http://dx.doi.org/10.1159/000369565.

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Dental erosive wear is a multifactorial condition that is greatly affected by environmental factors. So far, no study has investigated how dental erosive wear is influenced by variations in enamel formation genes. The aim of the present study was to investigate polymorphisms in genes involved in enamel formation and their influence on enamel susceptibility to dental erosion. DNA samples were collected from 795 Norwegian adolescents aged 16-18 years. Five single-nucleotide polymorphism markers were genotyped in selected candidate genes (ameloblastin, amelogenin, enamelin, tuftelin 1 and tuftelin interacting protein 11), reported to influence enamel formation. Allele and genotype frequencies were compared within two patient groups with dental erosions; all participants with dental erosion and only those with severe dental erosion (erosion extending into dentine). Overrepresentation of the G allele of the enamelin marker was seen in the erosion group compared to the unaffected group (p = 0.047). When erosion severity was considered, statistical significant difference in allele frequency was observed for amelogenin, with the C allele suggesting a protective role (p = 0.02). A suggestive overrepresentation of the TT genotype of the amelogenin marker was also seen in cases with severe erosion (p = 0.049) when compared to cases with no dentine erosion. Amelogenin was also associated with severe erosion in the recessive model; the TT genotype was significantly more frequent in the affected group than in the unaffected group (p = 0.01). The present study suggests that polymorphisms in enamel formation genes are statistically associated with an individual's susceptibility to dental erosive wear.

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Perl, M., C. Levy e Q. Ma. "The Influence of Multiple Axial Erosions on the Fatigue Life of Autofrettaged Pressurized Cylinders". Journal of Pressure Vessel Technology 123, n. 3 (5 febbraio 2001): 293–97. http://dx.doi.org/10.1115/1.1372325.

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Erosion geometry effects on the mode I stress intensity factor (SIF) for a crack emanating from an erosion’s deepest point in a multiply eroded, autofrettaged, pressurized, thick-walled cylinder are investigated. The problem is simulated as a two-dimensional problem and is solved via the finite element method. Autofrettage, based on von Mises yield criterion, is simulated by thermal loading and SIFs are determined by the nodal displacement method. SIFs are evaluated for a variety of relative crack lengths, a0/t=0.01-0.45 emanating from the tip of erosions of different geometries, namely, (a) semi-circular erosions of relative depths of 1–10 percent of the cylinder’s wall thickness, t; (b) arc erosions for several dimensionless radii of curvature, r′/t=0.05-0.4; and (c) semi-elliptical erosions with ellipticities of d/h=0.5-1.5, and erosion span angle, α, from 6 deg to 360 deg. The effective SIF for relatively short cracks is found to be increased by the presence of the erosion, which in turn may result in a significant decrease in the vessel’s fatigue life of up to an order of magnitude. Deep cracks are found to be almost unaffected by the erosion.

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Touma, Zahi, Arane Thavaneswaran, Vinod Chandran, Fawnda Pellett, Richard J. Cook e Dafna D. Gladman. "Clinical and Demographic Characteristics of Erosion-free and Erosion-present Status in Psoriatic Arthritis in a Cohort Study". Journal of Rheumatology 43, n. 6 (1 aprile 2016): 1057–62. http://dx.doi.org/10.3899/jrheum.150466.

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Objective.Psoriatic arthritis (PsA) has been recognized as a severe erosive disease. However, some patients do not develop erosions. We aimed to determine the prevalence, characteristics, and predictors of erosion-free patients (EFP) as compared with erosion-present patients (EPP) among patients with PsA followed prospectively.Methods.This is a retrospective analysis conducted on patients from the Toronto PsA cohort. Patients with at least 10 years of followup and radiographs were analyzed. Radiographs were scored with the modified Steinbrocker method. Baseline (first visit to clinic) characteristics were used to predict the development of erosions with logistic regression models. To examine the effect of time-varying covariates, Cox regression models were fit for the time to development of erosions from baseline.Results.Among 290 patients, 12.4% were EFP and 87.6% were EPP over the study period. The mean time to development of erosion in the EPP over the course of followup was 6.8 ± 6.1 years. EFP were diagnosed with psoriasis at a younger age compared with EPP. In both models, actively inflamed joints and clinically damaged joints were predictive of the development of erosion, whereas a longer duration of psoriasis at baseline decreased the odds of developing erosion. EPP had a higher percentage of unemployment as compared with EFP at baseline and followup visits.Conclusion.Among patients with PsA followed for at least 10 years, 12.4% never develop erosions. The clinical and radiographic findings can ultimately assist in the stratification of a patient’s prognosis regarding the development of erosions.

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Penmetsa, G., S. Pei, B. Sauer, J. A. Walsh, B. Feng, J. Walker, K. Douglas e J. Clewell. "POS0262 IDENTIFYING EROSIVE DISEASE FROM RADIOLOGY REPORTS OF VETERANS WITH INFLAMMATORY ARTHRITIS USING NATURAL LANGUAGE PROCESSING". Annals of the Rheumatic Diseases 80, Suppl 1 (19 maggio 2021): 353.2–354. http://dx.doi.org/10.1136/annrheumdis-2021-eular.1794.

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Background:The presence of erosive disease influences diagnosis, management, and prognosis in inflammatory arthritis (IA).Research of IA in large datasets is limited by a lack of methods for identifying erosions.Objectives:To develop methods for identifying articular erosions in radiology reports from veterans with IA.Methods:Included veterans had ≥2 ICD codes for ankylosing spondylitis (AS), psoriatic arthritis (PsA), or rheumatoid arthritis (RA) between 2005- 2019, in Veterans Affairs Corporate Data Warehouse. Chart review & annotation of radiology notes produced the reference standard, & identified erosion terms that informed classification rule development. A rule-based natural language processing (NLP) model was created & revised in training snippets. The NLP method was validated in an independent reference sample of IA patients at the snippet & patient levelsStepDescriptionNumber & example1 Radiology notesa.Select note titles potentially relevant to IAa. 35,141 notes titlesb.Extract notes with titles potentially related to IAb. 2,926,113 radiology notes2 Possible meaningful termsa.Compile list of root terms that may indicate erosiona. 11 root terms (i.e. ero*, pencil*cup, irreg*)b.Query radiology notes for root term variationsb. 1178 variations (i.e. erosion, erotic, erode)c.Select possible meaningful termsc. 179 possible terms (i.e. erosion, erode)3 Annotationa.Extract snippets^ containing possible meaningful termsa.5000 snippets from radiology notesb.Classify snippets according to: 1) Meaningful term, 2) Relevance to joint, 3) Attribution to IA, 4) Affirmationb.4068 classifications with 1017 snippets (in rounds of 50-417 snippets for NLP training & testing)4 Rule developmenta.Identify meaningful terms representing erosiona. 6 terms (pencil * cup, erosion, erosive, etc.)b.Exclude erosive processes irrelevant to joint(s)b. 28 irrelevant processes (i.e. gastric erosion)c. Exclude articular erosive processes not attributed to IAc. 5 non-IA processes IA (i.e. infection)d. Classify as affirmed/negated (erosion present/absent)d. 83 affirmation/negation rules5 NLP trainingDesign & revise NLP model until accuracy ≥90%6 rounds, 817 snippets (AS 417, RA 200, PsA 200)6 NLP testingTest NLP model200 snippets (AS 100, RA 50, PsA 50)7 Pt classificationa. Develop rules for classifying pts with discordant snippetsa. 5 rules developed in 368 ptsb. Build reference sample (pts classified as erosive or non-erosive via chart review)b. 30 IA pts (10 AS, 10 RA, 10 PsA)8 NLP validationValidate NLP model in reference sample at snippet level149 snippets (29 AS, 76 RA, 44 PsA)9 Method validationValidate methods (NLP+pt classification) at pt level30 IA pts (reference sample)pt= patient. ^Snippets include text containing 30 words before & after meaningful termsResults:In 168,667 veterans with IA, the mean age was 63.1 & 90.3% were male. Method development involved radiology note & erosion term selection, rule development, NLP model building, & method validation. The NLP model accuracy was 94.6% at the snippet level & 90.0% at the patient level, for all IA patients.Accuracy of methods.Conclusion:The methods accurately identify erosions from radiology reports of veterans with IA. They may facilitate a broad range of research involving cohort identification & disease severity stratificationReferences:[1]Walsh JA, et al. J Rheumatol. 2020;47(1):42-49Disclosure of Interests:Gopi Penmetsa: None declared, Shaobo Pei: None declared, Brian Sauer Grant/research support from: I have been an investigator on research contracts supported by Abbvie., Jessica A. Walsh Consultant of: AbbVie, Amgen, Janssen, Lilly, Novartis, Pfizer, UCB, Grant/research support from: AbbVie, Merck, Pfizer, Bingjian Feng Grant/research support from: Bing-Jian Feng reports funding and sponsorship to his institution on his behalf from Pfizer Inc., Regeneron Genetics Center LLC, and Astra Zeneca (UK). The PERCH software, for which Bing-Jian Feng is the inventor, has been non-exclusively licensed to Ambry Genetics for clinical genetic testing services and research., Jodi Walker Shareholder of: Abbvie and mutual funds containing various pharmaceutical companies, Employee of: Abbvie, Kevin Douglas Shareholder of: employed by Abbvie, Employee of: employed by Abbvie, Jerry Clewell Shareholder of: Own Abbvie Shares and mutual funds that hold pharmaceutical and other health care stocks, Employee of: I am current Abbvie Inc employee and past employee of Eli Lilly co

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Kovalenko, P. S., I. S. Dydykina, A. V. Smirnov e E. L. Nasonov. "Changes in erosion count scores during denosumab therapy in patients with rheumatoid arthritis". Medical alphabet, n. 31 (13 gennaio 2024): 39–42. http://dx.doi.org/10.33667/2078-5631-2023-31-39-42.

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Background. Rheumatoid factor (RF) and antibodies to cyclic citrullinated peptide (ACCP) are associated with the progression of joint erosions in RA. Currently, the efficacy of anti-osteoporotic therapy for the prevention of erosive arthritis is discussing.The aim of the study. To evaluate the effect of denosumab on the erosion score progression in patients with RA and OP, taking into account the activity of the disease and RF or ACCP positivity.Materials and methods. The study included 66 postmenopausal women with determined diagnosis of RA and OP. Non-erosive arthritis was in 23 (35 %) patients, erosive – in 21 (32 %), ankylosis of the joints was diagnosed in 22 (33 %) people. RF (+) was detected in 47 (72 %) people, ACCP (+) – in 48 (74 %) people. Denosumab 60 mg was injected subcutaneously once every 6 months (two injections). The duration of follow-up was 12 months. RA activity was assessed by the DAS 28 index. The erosion was calculated according to the Sharp / van der Heijde (SVH) method.Results. RA patients were divided into four groups: RF (+) and RF (–), ACCP (+) and ACCP (–), comparable in basic clinical features. At the same time, in the RF (+) group, the duration of RA, the frequency of ankylosis of the joints and the erosion count were initially higher compared to the RF (–). After 12 months of therapy, 7 (14.9 %) patients in the RF (+) group and 8 (16.7 %) patients in the ACCP (+) group the number of erosions has increased. There was no increase in the number of erosions in the RF (–) and ACCP (–) groups. In the analyzed groups, there were no changes in the erosion count depending on RA activity.Conclusions. An increase in the erosion score was found in the RF (+) and ACCP (+) groups despite the treatment with denosumab. In the RF (–) and ACCP (–) groups this indicator did not change. The inclusion of denosumab in the complex therapy of RA and OP is reasonable for prevention of OP and erosions progression in women with seronegative RA.

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Levy, C., M. Perl e Q. Ma. "The Influence of Multiple Axial Erosions on a Three-Dimensional Crack in Determining the Fatigue Life of Autofrettaged Pressurized Cylinders". Journal of Pressure Vessel Technology 124, n. 1 (22 maggio 2001): 1–6. http://dx.doi.org/10.1115/1.1386656.

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Erosion geometry effects on the mode I stress intensity factor (SIF) for a crack emanating from an erosion’s deepest point in a multiply eroded, autofrettaged, pressurized, thick-walled cylinder are investigated. The problem is solved via the finite element method (FEM). Autofrettage, based on von Mises yield criterion, is simulated by thermal loading and SIFs are determined by the nodal displacement method. SIFs are evaluated for a variety of relative crack depths, a0/t=0.01-0.40, and crack ellipticities, a0/c=0.5-1.5, emanating from the tip of erosions of different geometry, namely: (a) semi-circular erosions of relative depths of 1–10 percent of the cylinder’s wall thickness, t; (b) arc erosions for several dimensionless radii of curvature, r′/t=0.05-0.4; and (c) semi-elliptical erosions with ellipticities of d/h=0.3-2.0. The erosion separation angle, α, is taken from 7 to 360 deg. Deep cracks are found to be almost unaffected by the erosion. The effective SIF for relatively short cracks is enhanced by the presence, separation distance and geometry of the erosion, as well as the crack geometry, and may result in a significant decrease in the vessel’s fatigue life of up to an order of magnitude.

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Jablonski-Momeni, Anahita, Franka Hanselmann, Peter Bottenberg e Heike Korbmacher-Steiner. "Detection of Erosive Changes on Smooth Surfaces with and without Orthodontic Brackets Using an Intraoral Scanner—An In Vitro Study". Diagnostics 13, n. 20 (17 ottobre 2023): 3232. http://dx.doi.org/10.3390/diagnostics13203232.

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Background: Consumption of acidic beverages favours development of erosions. Modern diagnostic methods are required to detect erosions at an early stage. This study aimed to evaluate the suitability of an intraoral scanner (IOS) for detection of erosive changes on smooth surfaces adjacent to orthodontic brackets. Methods: Orthodontic metal brackets were attached to the buccal surfaces of 58 extracted permanent human teeth. Teeth were randomly divided into groups: A = 6% citric acid, B = Coca-Cola, C = Redbull, D = Powerade, E = Control, no acid exposure. Teeth were exposed to acid in three erosion cycles, followed by rinsing and brushing. Scans of teeth were performed at baseline and after each erosion cycle and enamel loss was measured. Quantitative light-induced fluorescence (QLF) measurements were performed as reference standard. Results: Significant substance loss was measured in all acid groups after the second and third erosion cycle (p < 0.0001). Correlation between scans and QLF were significant (p = 0.001). Conclusions: With IOS, it was possible to detect and quantify enamel erosion at smooth surfaces with and without orthodontic brackets after a short exposure time. Considering the limitations of in vitro results, the use of IOS can be a promising digital tool to detect and monitor erosive enamel changes during fixed orthodontic treatment.

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Levy, C., M. Perl e H. Fang. "Cracks Emanating From an Erosion in a Pressurized Autofrettaged Thick-Walled Cylinder—Part I: Semi-Circular and Arc Erosions". Journal of Pressure Vessel Technology 120, n. 4 (1 novembre 1998): 349–53. http://dx.doi.org/10.1115/1.2842342.

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Erosion geometry effects on the mode I stress intensity factor (SIF) for a crack emanating from the erosion’s deepest point in an autofrettaged, pressurized, thick-walled cylinder are investigated. The problem is solved via the FEM method and knowledge of the asymptotic behavior of short cracks. Autofrettage, based on von Mises yield criterion, is simulated by thermal loading and SIFs are determined by the nodal displacement method. SIFs are evaluated for a variety of relative crack lengths, a0/W = 0.01 – 0.45, emanating from the tip of erosions of different geometries. In Part I of this paper, two configurations are considered: (a) semi-circular erosions of relative depths of 5 percent of the cylinder’s wall thickness, W; and (b) arc erosions for several dimensionless radii of curvature, r′/W = 0.05 – 0.4. While deep cracks are almost unaffected by the erosion, the effective SIF for relatively short cracks is found to be significantly enhanced by the presence and geometry of the erosion and might reduce the vessel’s fatigue life.

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Levy, C., M. Perl e Q. Ma. "The Influence of Finite Three-Dimensional Multiple Axial Erosions on the Fatigue Life of Partially Autofrettaged Pressurized Cylinders". Journal of Pressure Vessel Technology 125, n. 4 (1 novembre 2003): 379–84. http://dx.doi.org/10.1115/1.1616582.

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Erosion geometry effects on the mode I stress intensity factor (SIF) for a crack emanating from the farthest erosion’s deepest point in a multiply, finite-length or full-length eroded, partially autofrettaged, pressurized, thick-walled cylinder is investigated. The problem is solved via the FEM method. Autofrettage, based on von Mises’ yield criterion, is simulated by thermal loading and SIFs are determined by the nodal displacement method. SIFs were evaluated for a variety of relative crack depths, a/t=0.01-0.30 and crack ellipticities, a/c=0.5-1.5 emanating from the tip of the erosion of various geometries, namely, (a) semi-circular erosions of relative depths of 1–10% of the cylinder’s wall thickness, t; (b) arc erosions for several dimensionless radii of curvature, r′/t=0.05-0.3; and (c) semi-elliptical erosions with ellipticities of d/h=0.5-1.5. In the cases of finite erosions, the semi-erosion length to the semi-crack length, Le/c, was between two and ten, erosion angular spacing, α, was between 7 and 120 degrees, whereas percent autofrettage investigated included 30%, 60%, and 100%. The normalized SIFs and the normalized effective SIFs of a crack emanating from the farthest finite erosion are found to rise sharply for values of Le/c<3. Both the normalized SIF and normalized effective SIF values are mitigated as the amount of partial autofrettage increases with the most rapid decrease occurring between 0–60% autofrettage. The purpose of this study is to detail these findings.

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ØSTERGAARD, MIKKEL, UFFE MØLLER DØHN, ANNE DUER-JENSEN, MERETE LUND HETLAND, KIM HØRSLEV-PETERSEN, KRISTIAN STENGAARD-PEDERSEN, PETER JUNKER, JAN PØDENPHANT e BO EJBJERG. "Patterns of Magnetic Resonance Imaging Bone Erosion in Rheumatoid Arthritis — Which Bones Are Most Frequently Involved and Show the Most Change?: Figure 1." Journal of Rheumatology 38, n. 9 (settembre 2011): 2014–17. http://dx.doi.org/10.3899/jrheum.110416.

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Objective.To investigate by magnetic resonance imaging (MRI) which bones in wrists and metacarpophalangeal (MCP) joints most frequently show bone erosions, and which most frequently demonstrate erosive progression, in early and established rheumatoid arthritis (RA).Methods.MRI datasets from 258 RA patients [126 with early RA (disease duration < 6 months)] were analyzed, of whom 223, including 126 with early RA, had 1-year followup MRI. All patients had MRI of one wrist, whereas 86 patients had additional images of 2nd–5th MCP joints, and 46 patients additional images of the contralateral wrist. MRI were evaluated blinded by one reader, according to the OMERACT RA MRI scoring system (RAMRIS) for erosions, and presence/absence of erosions was noted in each bone, as was presence/absence of erosive progression.Results.The capitate, ulna, lunate, triquetrum, and scaphoid were the 5 bones with both most frequent baseline erosions and most frequently demonstrated erosive progression. No bones were without erosions. Patterns of erosions and progression were similar in early and established RA. No major difference between dominant and nondominant wrists was detected. In the fingers, the 2nd–3rd MCP joint most frequently displayed erosions and erosive progression.Conclusion.The distribution and frequency of bone erosion and erosive progression as detected by MRI in RA wrists and MCP joints were identified. No pattern differences between early versus established disease and dominant versus nondominant sides were detected. No bones showed erosive progression. Thus, no self-evident simplification of the RAMRIS erosion score was identified. Bone involvement patterns may be considered, when joints are selected for MRI protocols for clinical trials and practice.

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Hayder Al-Khayat, Rasha, Maher A. R. Sadiq Al-Baghdadi, Ragad Aziz Neama e Muhannad Al-Waily. "Optimization CFD study of erosion in 3D elbow during transportation of crude oil contaminated with sand particles". International Journal of Engineering & Technology 7, n. 3 (11 luglio 2018): 1420. http://dx.doi.org/10.14419/ijet.v7i3.14180.

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The oil industry transport the crude oil, but with entrained solid particles. Throughout the production operations of the upstream petroleum, crude oil as well as sand particles corroded from the zones of the formation are regularly conveyed through pipes as a mixture up to the well heads and among well heads and flow stations. In this study, a three-dimensional CFD (Computational fluid dynamics) model has been developed that describes a turbulent transport of solid sand particles as well as crude oil through elbows to predict the erosions rates, where various physical aspects have been combined together including flow turbulence, particle tracking, and erosion simulation. The model has been used to investigate the different parameters that effect for crude oil and sand particles on the erosive wear rate on the pipe walls. Where, the parametric studied for crude oil are viscosity, density, velocity and temperature, also, the parametric studied for sand particles are parti-cles size, particles density and mass flow rate. Therefore, the investigation included evaluated the erosive wear rate on the pipe walls with different parametric studding by using numerical method with CFD technique. This model includes simulation of the three dimensional for turbulent flow, sand particle, and erosion rates modeling. Where, used three methods to evaluating the erosive wear rate on the pipe walls, The Finite Model, The Erosion Rate (E/CRC) Model and The Erosion rate (DNV) Model. Also, in this work can be prediction of the ero-sion position occur on the pipe wall with various parametric effect. Then, the results presented shown that the rate of erosion is increase with increasing the friction between the oil and pipe wall by variable the parametric of crude oil or sand particles. Also, the results are shown that the position of erosion variable dependent on the parametric of oil and sand. Finally, the work shown that the CFD technique is good tool can be used to evaluating the erosion rate and erosion position on pipe wall with various crude oil and sand particles parametric.

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Oliveira, Bianca Souza de, Antonio Conceição Paranhos Filho e Eliane Guaraldo. "Identification of erosive processes with free geotechnologies." Terr Plural 16 (settembre 2022): 1–17. http://dx.doi.org/10.5212/terraplural.v.16.2219806.023.

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Linear erosion is one of the types of water erosion that cause the most environmental problems due to the concentration of water flows that has great potential for land degradation. This work aims to identify areas of eroded soil that occur in the Paraíso River Watershed using free geotechnologies through the vectorization of erosion identified through the analysis of high spatial resolution satellite images freely available on the Google Earth platform. The results obtained point out that in the Paraíso River watershed most of the linear erosions are furrow-type features, the mildest form of this type of erosive process. A total of 463 erosion axes were identified, composed of furrows, ravines, and gullies. The temporal monitoring of images has elucidated the origin of the silting identified in a stretch of the Paraíso River near the MS-316 highway. Thus, the availability of high spatial resolution satellite images associated with the resources available for processing spatial data makes it possible to analyze extensive areas and identify erosive processes with greater agility, helping to identify the measures to be adopted to contain and/or recover the sites affected by this environmental problem.

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Peran, M., E. Allado, E. Albuisson, M. Couderc, P. Ornetti, C. Roux, J. Grosse, I. Chary Valckenaere e D. Loeuille. "AB1125 PERFORMANCE OF ULTRASOUNDS TO ASSESS EROSION PROGRESSION IN RHEUMATOID ARTHRITIS". Annals of the Rheumatic Diseases 79, Suppl 1 (giugno 2020): 1851.2–1852. http://dx.doi.org/10.1136/annrheumdis-2020-eular.2444.

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Background:Ultrasonography (US) can detect more erosions than radiography (RX) at the joint level in rheumatoid arthritis (RA), especially at an early stage of the disease.Objectives:The aim of the study is to determine the ability of ultrasonography to detect erosion progression by the US Score for erosions (USSe), in early (less than 2 years disease duration (DD)) and late stage (more than 2 years DD) RA over two years of follow-up.Methods:Patients fulfilling ACR 1987 and/or ACR/EULAR 2010 criteria for RA were prospectively included. Clinical and demographic informations were recorded at baseline and hands and feet RX were scored according to the Sharp erosion score (SHSe). Erosive RA on RX was defined by the presence of at least three eroded joints (1). US examinations were performed at baseline and during the two years of follow-up. Erosions were scored by US on six bilateral joints (MCP 2, 3, 5 and MTP 2, 3, 5) with a four grade-scale to calculate total USSe. Erosive RA on US was defined by presence of one erosion ≥ 2mm (2). Inter-examiner reproducibility was performed on 14 patients in order to calculate the smallest detectable change (SDC), which was 2.3. Ultrasonographic progression was defined as a change in USSe > 2 (erosion change > SDC).Results:A total of 71 patients were included, 22 patients (31.0%) had early RA and 49 (69.0%) patients had late RA diseases. On RX, 30 (42.3%) patients were erosive at baseline with a mean SHSe at 29.4 (SD at 24.7). On US, 63 patients (88.7%) were classified as eroded. On US, erosions prevailed at baseline in MTP5 joints, then MCP2 and MCP5 joints on their lateral facets. During follow-up, 28 patients (39.4%) were classified as US progressors, 30 (42.3%) were stable and 13 (18.3%) considered as regressors (figure 1). In early RA disease, three of the four non eroded patients became eroded. USSe progressed in 11 patients (50%) while regression was observed in only one patient. In late RA disease, 17 patients (34.7%) progressed and 12 patients (24.5%) decreased significantly their USSe. Erosion progression prevailed on MTP 5 joints followed by MCP2 and finally MCP5 joints (figure 2).Figure 1.USSe progression plots (n=71)Figure 2.Differences of USSe by joints during follow-up in early and late RAConclusion:US structural examination is a highly reproducible method to assess erosion in RA disease. The USSe is able to detect structural changes (progression, stabilization and regression) in RA patients during a follow-up of two years especially in RA patients with short disease duration.References:[1]Van der Heijde D, van der Helm-van Mil AHM, Aletaha D, Bingham CO, Burmester GR, Dougados M, et al. EULAR definition of erosive disease in light of the 2010 ACR/EULAR rheumatoid arthritis classification criteria. Ann Rheum Dis. avr 2013;72(4):479‑81.[2]Roux C, Gandjbakhch F, Pierreisnard A, Couderc M, Lukas C, Masri R, et al. Optimization of ultrasonographic examination for the diagnosis of erosive Rheumatoid Arthritis in comparison to erosive hand Osteoarthritis. Eur J Radiol. sept 2019;118:10‑8.Disclosure of Interests:None declared

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Srikhum, Waraporn, Warapat Virayavanich, Andrew J. Burghardt, Andrew Yu, Thomas M. Link, John B. Imboden e Xiaojuan Li. "Quantitative and Semiquantitative Bone Erosion Assessment on High-resolution Peripheral Quantitative Computed Tomography in Rheumatoid Arthritis". Journal of Rheumatology 40, n. 4 (15 febbraio 2013): 408–16. http://dx.doi.org/10.3899/jrheum.120780.

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Objective.To develop novel quantitative and semiquantitative bone erosion measures at metacarpophalangeal (MCP) and wrist joints in patients with rheumatoid arthritis (RA) using high-resolution peripheral quantitative computed tomography (HR-pQCT), and to correlate these measurements with disease duration and bone marrow edema (BME) patterns derived from magnetic resonance imaging (MRI).Methods.Sixteen patients with RA and 7 healthy subjects underwent hand and wrist HR-pQCT and 3-Tesla MRI. Bone erosions of the MCP2, MCP3, and distal radius were evaluated by measuring maximal erosion dimension on axial slices, which is a simple and fast measurement, and then were graded (grades 0–3) based on the maximal dimension. Correlation coefficients were calculated between (1) sum maximal dimensions, highest grades, and sum grades of bone erosions; (2) erosion measures and the clinical evaluation; (3) erosion measures and BME volume in distal radius.Results.The inter- and intrareader agreements of maximal erosion dimensions were excellent (intraclass correlation coefficients 0.89, 0.99, and root mean square error 9.4%, 4.7%, respectively). Highest grades and sum grades were significantly correlated to sum maximal dimensions of all erosions. Number of erosions, sum maximal erosion dimensions, highest grades, and sum grades correlated significantly with disease duration. Number of erosions, sum maximal dimensions, and erosion grading of the distal radius correlated significantly with BME volume.Conclusion.HR-pQCT provides a sensitive method with high reader agreement in assessment of structural bone damage in RA. The good correlation of erosion measures with disease duration as well as BME volume suggests that they could become feasible measures of erosions in RA.

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Sharma, Rohit, Ashish Mehrotra, Vinit K. Sharma, Zafar Iqbal e Kunal Nigam. "A Retrospective Study of Bony Erosion Patterns in Cases of Fungal Rhinosinusitis". An International Journal Clinical Rhinology 9, n. 2 (2016): 62–64. http://dx.doi.org/10.5005/jp-journals-10013-1269.

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ABSTRACT Erosion of bone with or without extension of disease into adjacent anatomic spaces is observed among some patients with fungal rhinosinusitis (FRS). Preoperative computed tomographies is very important to determine the sites of bony erosion. Patients with bony erosions are classified based on the involved subsite and the extent of erosion. Bony erosions was seen in 37.5% cases. Six patients were having bone erosions on CT scan. 40 % erosions were present in patients belonging to younger age group. Erosion of sinus boundaries were more common in male patients (60%). The ethmoid sinus complex was most commonly involved (46.6%). This was followed in frequency of involvement by the maxillary sinus (26.6%), the sphenoid sinus (20%) and the frontal sinus (6.6%). The most common site of erosion was the lamina papyracea (33.3%), followed by the medial maxillary wall (20%). Bony erosions due to FRS were mainly due to long-term mechanical compression by the fungal mass. A case of chronic rhinosinusitis with bony erosions in CT scan may indicate a fungal etiology. How to cite this article Sharma VK, Sharma R, Mehrotra A, Iqbal Z, Nigam K. A Retrospective Study of Bony Erosion Patterns in Cases of Fungal Rhinosinusitis. Clin Rhinol An Int J 2016;9(2):62-64.

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Stojsin, Ivana, Tatjana Brkanic e Slavoljub Zivkovic. "Reflux disease as an etiological factor of dental erosion". Srpski arhiv za celokupno lekarstvo 138, n. 5-6 (2010): 292–96. http://dx.doi.org/10.2298/sarh1006292s.

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Introduction Gastroesophageal reflux is a frequent disease which has a significant influence on the development of dental erosions. Objective The aim of this research was to determine the frequency of dental erosions among the patients with gastroesophageal reflux, as well as to verify the most common symptoms of gastroesophageal disease. Methods The research comprised of two groups, each consisting of 30 patients aged 18-80 years. The experimental group comprised of patients diagnosed with gastroesophageal reflux disease (GERD), while the control group was composed of patients who were not diagnosed with GERD. Based on the illness history data, all patients of the experimental group were registered to have gastroesophageal and extraesophageal symptoms. Dental erosions were diagnosed during a stomatological inspection by using index system according to Eccles and Jenkins. Data processing was accomplished by the Statgraphics Centurion software package. Results Dental erosions were found in 76.7% of experimental group patients, and in 53.3% of control group patients. Fortynine percent of teeth of the experimental group patients and 31.1% of the control group patients showed erosive changes. On average, the number of teeth with erosions in the experimental group was 15.7 per person and in the control group 10 per person. The teeth of the front region of the upper jaw, as well as the lower first molars had the highest average value of dental erosion index. In the experimental group 12.8% of teeth and 24% of teeth in the control group were diagnosed to have dental erosion index value 1. Furthermore, 23.4% of teeth in the experimental group and 7.1% of teeth in the control group were registered to have dental erosion index value 2. Finally, the dental erosion index value 3 was found in 13.0% of teeth in the experimental group only. The highest average value of regional erosion index in the experimental group was found in the region 13-23 equalling 1.0. The same value in the control group equalled 0.6. In the experimental group the average value of dental erosion index for the upper jaw was 0.9, while this value for the lower jaw equalled 0.8. The analysis of the illness history data obtained showed that there was a statistically significant difference between the two observed groups in terms of burning pain (noncardiac in origin) around the heart area, bad breath and dentine hypersensitivity as the dominant symptom of dental erosion (p<0.05). Conclusion Dental erosions could be considered to be the extraesophageal manifestation of gastroesophageal reflux. .

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Le, Phuong M., Sonali Pal-Ghosh, A. Sue Menko e Mary Ann Stepp. "Immune Cells Localize to Sites of Corneal Erosions in C57BL/6 Mice". Biomolecules 13, n. 7 (29 giugno 2023): 1059. http://dx.doi.org/10.3390/biom13071059.

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Recurrent epithelial erosions develop in the cornea due to prior injury or genetic predisposition. Studies of recurrent erosions in animal models allow us to gain insight into how erosions form and are resolved. While slowing corneal epithelial cell migration and reducing their proliferation following treatment with mitomycin C reduce erosion formation in mice after sterile debridement injury, additional factors have been identified related to cytokine expression and immune cell activation. The relationship between recruitment of immune cells to the region of the cornea where erosions form and their potential roles in erosion formation and/or erosion repair remains unexplored in the C57BL/6 mouse recurrent erosion model. Here, high resolution imaging of mouse corneas was performed at D1, D7, and D28 after dulled-blade debridement injury in C57BL/6 mice. Around 50% of these mice have frank corneal erosions at D28 after wounding. A detailed assessment of corneas revealed the involvement of M2 macrophages in both frank and developing erosions at early stages of their formation.

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Mandl, P., I. Gessl, G. Filippou, S. Sirotti, L. Terslev, C. Pineda, E. Cipolletta et al. "POS0161 AN ULTRASOUND SCORING SYSTEM BASED ON THE SIZE AND NUMBER OF EROSIONS IS RELIABLE IN RHEUMATOID ARTHRITIS". Annals of the Rheumatic Diseases 82, Suppl 1 (30 maggio 2023): 303.1–303. http://dx.doi.org/10.1136/annrheumdis-2023-eular.2842.

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BackgroundUltrasound has been shown to be a valid tool for the evaluation of bone erosions in rheumatoid arthritis (RA), yet a consensual scoring system is lacking.ObjectivesTo assess the reliability of a semiquantitative scoring system for assessing structural bone erosion by ultrasound in a web-based reliability exercise.MethodsA task force of the OMERACT Ultrasound Working Group developed definitions and a scoring system for grading bone erosions which takes both the size and number of erosions into consideration. Pairs of static images (longitudinal and transverse) in DICOM format of metacarpophalangeal and proximal interphalangeal joints 2-5 were acquired prospectively in healthy controls and in RA patients with varying degrees of pathology by the task force members. A dataset of anonymized images, representing various grades was created and utilized in a web-based exercise using the cmrad.com cloud platform which allowed the participants to measure the size of the erosions and use the discrete measures and the number of erosions to grade each joint according to the scoring system. Both the longitudinal and transverse scans were considered and the largest diameter chosen for each erosion. Intra- and inter-reader reliability of the scoring system was assessed using kappa statistics.ResultsA 4-grade semiquantitative scoring system was developed: grade 0) intact cortical bone; grade 1) single small erosion (diameter: ≤2mm); grade 2) single large erosion (diameter: >2mm) or 2 small erosions or 1 large and 1 small erosion; grade 3) 2 large erosions or ≥3 erosions, regardless of size (Figure 1). A dataset composed of 45 anonymised image pairs (90 single images) was graded by 20 task force members in two rounds separated by 10 days. The intra-reader (mean: 0.79; 95% confidence interval: 0.75-0.84) reliability was excellent and the inter-reader (mean: 0.75; 95% confidence interval: 0.74-0.76) reliability was substantial.ConclusionThis preliminary OMERACT scoring system for bone erosions of the finger joints in RA has demonstrated excellent reliability on static images. Further studies are required to evaluate the reliability of the combined acquisition and reading of images in patients.Figure 1.Representative images of the different grades of the scoring system for bone erosion in rheumatoid arthritis. A) grade 0: intact cortical bone;B) grade 1: single small erosion (diameter: ≤2mm);C1) grade 2: single large erosion (diameter: >2mm);C2) grade 2: 2 small erosions;C3) grade 2: 1 large and 1 small erosion;D1) grade 3: 2 large erosions;D2) grade 3: ≥3 erosions, regardless of sizeREFERENCES:NIL.Acknowledgements:NIL.Disclosure of InterestsNone Declared.

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Yasmine, M., H. Ferjani, D. Kaffel, K. Maatallah, S. Rahmouni e W. Hamdi. "AB0124 STRUCTURAL DAMAGE IN THE FOOT IN RHEUMATOID ARTHRITIS: DON’T MISS THE OTHER METATARSOPHALANGEAL JOINTS". Annals of the Rheumatic Diseases 80, Suppl 1 (19 maggio 2021): 1091.1–1091. http://dx.doi.org/10.1136/annrheumdis-2021-eular.2227.

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Background:The foot involvement in rheumatoid arthritis (RA) affects the functionality and the quality of life in patients. Despite this, the clinicians do not give enough care to the foot in RA patients, especially if asymptomatic, resulting in joint damage, deformity, and disability. The distribution of erosions of the other MTP joints (excluding the 5th) has not previously been studied.Objectives:This study aimed to investigate the distribution of erosions in MTP joints and their clinical implications.Methods:We conducted a retrospective study including patients with RA according to the American college of rheumatology/ the European league against rheumatism classification criteria. Sociodemographic data, as well as disease activity related characteristics, were recorded.Posterior–anterior radiographs of the hands and feet of each patient were assessed for erosions.All patients were assessed by Ultrasonography (US) of the hands. US erosions were scored 0-3 according to Szkudlarek [1]. We divided patients into two groups (G1 without MTPs erosions and G2 with MTPs erosions).Results:We enrolled forty-two females and eleven males in our studies. The mean age was 58.6 years ±12.7 [23-77], and the mean disease duration was 8.4 years [1-47]. Rheumatoid factor or cyclic citrullinated peptide antibodies (Anti-CCP) were positive in 62.3% of cases. The mean DAS28ESR score was 5.1±1.16 [2.5-7.7]. Half of the patients had the active disease (52.8%). Hand erosions evaluated with plain radiographs and the US were found in 43.1% and 50.9% of cases, respectively. The distribution of foot erosions (15.1%) was at follows: 5th right MTP (7.5%), the 5th right IPP (2%), the 1st left MTP (2%), 3th left MTP (3.8%), 4th left MTP (5.7%) and the 5th left MTP (9.4%). Erosions on MTPs with the exclusion of the 5th MTP were present in 9.4% of cases. The presence of MTPs erosion was more frequent in males (p=0.01) but was not associated with age (p=0.6) or disease duration (p=0.2). Seropositivity was similar between the two groups (p=0.06). Similarly, the inflammatory markers (ESR and CRP), as well as DAS28 ESR, did not differ between the two groups (p>0.05). MTPs erosion was not associated with the presence of hand erosions on a plain radiograph (p=0.445). However, MTPs erosion was significantly more frequent in patients with less erosive hands-on US (p=0.034).Conclusion:Our study showed that screening of other MTPs (excluding the 5th) is mandatory in RA diagnosis. Interestingly, in our result, MTPs erosion is more frequent in males with less erosive hands.Disclosure of Interests:None declared

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Perl, M., C. Levy e H. Fang. "Cracks Emanating From an Erosion in a Pressurized Autofrettaged Thick-Walled Cylinder—Part II: Erosion Depth and Ellipticity Effects". Journal of Pressure Vessel Technology 120, n. 4 (1 novembre 1998): 354–58. http://dx.doi.org/10.1115/1.2842343.

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In Part I of this paper, the effects of constant depth erosion on the mode I stress intensity factor (SIF) were determined for a crack emanating from the erosion deepest point in a pressurized, autofrettaged, thick-walled cylinder. The erosion geometries investigated included semi-circular erosions and several arc erosions of various radii of curvature. Due to the trends found in that portion of the study, erosion depth and ellipticity are believed to have equally important impact on the SIFs. The present paper delves further into these two parameters using the following configurations: (a) semi-circular erosions of relative depths of 1–10 percent of the cylinder’s wall thickness, W; and (b) semi-elliptical erosions with ellipticities of d/h = 0.3 – 2.0. Deep cracks are found to be practically unaffected by the erosion, similar to the results presented in Part I of the paper. The effective SIF for relatively short cracks is found to be dramatically enhanced by the stress concentration factor (SCF), which encompasses the depth of the erosion as well as its radius of curvature at the tip. As a result of the increased effective SIF, a significant decrease in the vessel’s fatigue life of up to an order of magnitude may occur.

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Oliveira, José Guilherme de, Alexei Nowatzki e Leonardo José Cordeiro Santos. "UTILIZAÇÃO DE ATRIBUTOS TOPOGRÁFICOS NO MAPEAMENTO DE SUSCETIBILIDADE EROSIVA NA ÁREA RURAL DO MUNICÍPIO DE PARANAVAÍ – PR". Revista Cerrados 15, n. 02 (16 marzo 2020): 201–19. http://dx.doi.org/10.22238/rc24482692v15n22017p201a219.

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A região noroeste do estado do Paraná ao longo dos últimos 50 anos vem sofrendo diversos impactos decorrentes de processos erosivos lineares, ravinas e voçorocas principalmente. A ocorrência desses processos está associada a dois fatores: o histórico de ocupação da região, bem como as características pedológicas locais, principalmente a textura dos solos e sua distribuição nas vertentes. O método adotado para o mapeamento de suscetibilidade é uma adaptação do proposto por Crepani et al. (2001). Esse autor define que a suscetibilidade de uma área é definida pela soma das vulnerabilidades dos componentes do meio físico. Para a realização do trabalho foram selecionados os atributos topográficos declividade e perfil de curvatura; na pedologia, as tipologias de solo. Os resultados foram discretizados em 5 classes: Muito baixa, baixa, média, alta e muito alta suscetibilidade. As áreas de suscetibilidade a erosão Alta e Muito alta, representam 24% do município, sendo que nessas porções se concentram 26% das erosões, o tipo de solo em conjunto com as características topográficas fazem essa área mais propicia naturalmente a ocorrência dos processos erosivos. A classe de moderada suscetibilidade a erosão representam cerca de 40% do município e 54% das feições erosivas se concentra nessa unidade. Palavras-chave: Erosão; Modelo Digital de Terreno; Álgebra de Mapas. USE OF TOPOGRAPHIC ATTRIBUTES IN THE EROSIVE SUSCEPTIBILITY MAPPING IN THE RURAL AREA OF THE MUNICIPALITY OF PARANAVAÍ – PR Abstract The northwest region of the state of Paraná over the last 50 years has suffered several impacts and consequences of linear erosives, ravines and gullies mainly. The occurrence of these processes is mainly associated with two factors: the occupation history of the region, as well as local soil characteristics, mainly the soil texture and a distribution of soils along the slopes. The methodology adopted for the mapping of susceptibility to erosion follows a line of thought developed by Crepani et al. (2001). This proposal defines that the vulnerability of an area is defined by the sum of the vulnerabilities of the components of the physical environment. For the accomplishment of the methodology were selected, to represent the geomorphology, the topographic attributes: slope, curvature plane and profile; for pedology, soil typologies were selected. The results were discretized in 5 classes, from environments less susceptible to the most susceptible. The areas of susceptibility to erosion High and Very high, summed represent 24% of the municipality, being that in these portions it concentrates 26% of the area of the erosions, once in these areas the type of soil together with the topographic characteristics make it more propitious to the occurrence of linear erosive processes.The moderate susceptibility to erosion class represent about 40% of the municipality and 54% of the area of erosive features is concentrated in this unit. Keywords: Erosions; Digital Terrain Model; Map Algebra. UTILIZACIÓN DE ATRIBUTOS TOPOGRÁFICOS EN EL MAPEO DE SUSCEPTIBILIDAD EROSIVA EN EL ÁREA RURAL DEL MUNICIPIO DE PARANAVAÍ – PR Resumen La región noroeste del estado de Paraná en los últimos 50 años viene sufriendo impactos producto de procesos erosivos lineales, regueros y cárcavas principalmente. La ocurrencia de estos procesos está asociada a dos factores: el modo de ocupación de la región y las características pedológicas locales, principalmente la textura de los suelos y su distribución en las vertientes. El método adoptado para el mapeo de susceptibilidad es una adaptación del propuesto por Crepani et al. (2001). Este autor especifica que la susceptibilidad de un área está definida por la suma de las vulnerabilidades de los componentes del medio físico. Para realizar este trabajo fueron seleccionados los atributos topográficos declividad y perfil de curvatura; en la pedología, las tipologías de suelo. Los resultados fueron representados en 5 clases: muy baja, baja, media, alta y muy alta susceptibilidad. Las áreas de susceptibilidad a erosión alta y muy alta, representan el 24% del municipio, sumado a ello en esas porciones se concentran el 26% de las erosiones, por lo tanto el tipo de suelo en conjunto con las características topográficas hacen de esas áreas las más propicias naturalmente a la ocurrencia de procesos erosivos. La clase de moderada susceptibilidad a erosión representa cerca del 40% del municipio y el 54% de los rasgos erosivos se concentran en esa unidad. Palabras claves: Erosión; Modelo Digital del Terreno; Álgebra del Mapas.

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Fang, Zi Qiang, Song Lin Peng e Liang Zhang. "A Test System for Plastic Metal Materials Subjected to Multi-particle Erosion via Air Ejector". Defect and Diffusion Forum 419 (20 ottobre 2022): 97–102. http://dx.doi.org/10.4028/p-4w8lu2.

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Erosive wear of working part is an usual damage mode of mechanized equipment in engineering, which is caused by multiple particle impacts with different impact angles and velocities. A test system for plastic metal materials subjected to multi-particle erosion is designed and manufactured. Based on the test system, trial samples of plastic metal materials suffered to multiple particle impacts can be produced via an air ejector, while images of corresponding damage surface can be observed with electron microscope. Erosion experiments of the twice particle erosions in succession were carried out through the experimental system with two different impact angles, i.e. 90° and 30°, and at a fixed impact velocity of 120 m/s. From the experiment results, it can be expected that the experimental system is suitable to laboratory tests of multi-particle erosion for plastic metal materials with reference to practical conditions in engineering.

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Meinhardsson, J., R. Klose-Jensen, J. Therkildsen, B. Langdahl, E. M. Hauge e K. Keller. "POS0133 HIGH-RESOLUTION PERIPHERAL QUANTITATIVE COMPUTED TOMOGRAPHY FOR THE EVALUATION OF BONE EROSIONS OF METATARSOPHALANGEAL JOINTS IN RHEUMATOID ARTHRITIS: A PILOT STUDY". Annals of the Rheumatic Diseases 81, Suppl 1 (23 maggio 2022): 293–94. http://dx.doi.org/10.1136/annrheumdis-2022-eular.3589.

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BackgroundBone erosion in rheumatoid arthritis (RA) is most commonly detected in the wrist, metacarpophalangeal (MCP) and metatarsophalangeal (MTP) joints. High-resolution peripheral quantitative computed tomography (HR-pQCT) has successfully been used to quantify bone erosions in the wrist and MCP joints. A recent study highlights that HR-pQCT of only two MCP joints has equal accuracy to detect erosive disease in RA patients compared to conventional radiography (CR) of the hands, wrists, and feet (44 joints)1. However, no study has evaluated the MTP joints by HR-pQCT.ObjectivesTo characterize the localization, size and frequency of erosions in the 4th and 5th MTP joints. Furthermore, to evaluate the sensitivity for the detection of erosion in the 4th and 5th MTP joints by HR-pQCT, compared to CR.MethodsThis single-centre cross-sectional study included 42 patients with established RA (disease duration ≥ 5 years). The right foot was imaged by HR-pQCT in a 2.7 cm long region corresponding to the 4th and 5th MTP joint. Blinded to patient data, the number and volume of bone erosions by HR-pQCT were measured and scored according to the SPECTRA criteria2. CR of 44 joints was evaluated according to the Sharp/van der Heijde (SHS) method.ResultsThe patients (62% women) had a median disease duration of 12 years (interquartile range (IQR): 7 – 20). HR-pQCT of the 4th and 5th MTP joints identified erosions in 38 (90%) patients. The total erosion volume (Vtot) was 2610 mm3 in all quadrants of the 4th and 5th MTP joints. Erosions were most frequently found at the lateral aspect of the 5th metatarsal head (MH), including 1261 mm3 (48%) of Vtot (Figure 1). CR of 44 joints detected erosions in 30 (71%) patients with a median SHS erosion score of 9 (5 – 28). The sensitivity and specificity (95% CI) of classifying patients with erosive RA by HR-pQCT and CR is displayed in Table 1. McNemar’s χ2 test showed a significantly higher sensitivity of patients classified as having erosive RA by HR-pQCT of the 4th and 5th MTP joints than by CR of 44 joints (4.6, p = 0.03).Table 1.Comparing CR and HR-pQCT for classifying patients as having erosive RA, and for identifying erosions in the 4th and 5th MTP joints.Sensitivity & specificity of classifying patients with erosive RA by HR-pQCT when CR of the hands, wrist and feet was used as referenceCRHands, wrists, and feet Erosive RACRHands, wrists, and feetNon-erosive RATotalSensitivity (95% CI)HR-pQCT4th and 5th MTP jointsErosive RA27113890.0 (73.5 – 97.9)Specificity (95% CI)HR-pQCT 4th and 5th MTP joints Non-erosive RA3148.3 (0.2 – 38.5)Total301242Sensitivity & specificity of classifying patients with erosive RA by CR when HR-pQCT was used as referenceHR-pQCT4th and 5th MTP jointsErosive RAHR-pQCT4th and 5th MTP jointsNon-erosive RATotalSensitivity (95% CI)CRHands, wrists, and feetErosive RA2733071.0 (54.1 – 84.6)Specificity (95% CI)CRHands, wrists, and feetNon-erosive RA1111225.0 (0.6 – 80.6)Total38442Conventional Radiography (CR), High-resolution peripheral Quantitative Computed Tomography (HR-pQCT), Metatarsophalangeal (MTP), Rheumatoid Arthritis (RA), Confidence Interval (CI).ConclusionThis is the first study to evaluate erosions with HR-pQCT of the 4th and 5th MTP joints, including a comparison to CR. Erosions were frequent at the lateral aspect of the MTP joints, suggesting that mechanical and biomechanical demands may play a role in the development of erosions in the MTP joints. The superiority of HR-pQCT compared to CR for detecting erosions provide a basis for larger studies assessing bone changes in the MTP joints.References[1]Klose-Jensen, R., et al. Diagnostic accuracy of high-resolution peripheral quantitative computed tomography and X-ray for classifying erosive rheumatoid arthritis. Rheumatology (Oxford) (2021).[2]Barnabe, C., et al. Definition for Rheumatoid Arthritis Erosions Imaged with High Resolution Peripheral Quantitative Computed Tomography and Interreader Reliability for Detection and Measurement. J Rheumatol43, 1935-1940 (2016).Disclosure of InterestsJørgen Meinhardsson: None declared, Rasmus Klose-Jensen: None declared, Josephine Therkildsen: None declared, Bente Langdahl Speakers bureau: UCB, Amgen, Eli Lilly, Gedeon-Richter, Gilead, Astellas, Consultant of: UCB, Amgen, Eli Lilly, Gedeon-Richter, Gilead, Astellas, Grant/research support from: Amgen and Novo Nordisk, Ellen-Margrethe Hauge Speakers bureau: AbbVie, Sanofi, Sobi, MSD, UCB, Consultant of: AbbVie, Sanofi, Sobi, MSD, UCB, Grant/research support from: Novo Nordic Foundation, Danish Rheumatism Association, Danish Regions Medicine Grants, Roche, Novartis, Kresten Keller: None declared

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Levy, C., M. Perl e Q. Ma. "Erosions and Their Effect on the Fatigue Life of Thick Walled, Autofrettaged, Pressurized Vessels". Journal of Pressure Vessel Technology 125, n. 3 (1 agosto 2003): 242–47. http://dx.doi.org/10.1115/1.1593698.

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This paper summarizes the results that have been found in evaluating the effect of erosions on thick walled, autofrettaged, pressurized, cracked vessels. The problem is solved numerically via the FEM method. Autofrettage, based on von Mises yield criterion, is simulated by thermal loading and stress intensity factors (SIF’s) are determined by the nodal displacement method. SIF’s were evaluated for a variety of relative crack depths a/t and crack ellipticities a/c emanating from the tip of the erosion of various geometries, namely, (a) semi-circular erosions of small relative depths of the cylinder’s wall thickness t; (b) arc erosions for several dimensionless radii of curvature r′/t; and (c) semi-elliptical erosions with ellipticities of d/h. Other parameters evaluated were, in the cases of finite erosions, the semi-erosion length to the semicrack length Le/c, the erosion angular spacing α, and the autofrettage level. First, we summarize the differences found between a vessel with one erosion and one with multiple erosions. We show that for full cylinder length erosions, the erosions tend to make smaller cracks more dangerous than larger cracks in fully autofrettaged vessels and that as the crack grows the stress intensity factor initially decreases. We then show that as the crack grows further, the effect is to increase the effective stress intensity factor (SIF) but also to practically void the existence of the erosion. We show further that lower levels of autofrettage will lead to higher effective SIF’s but that partially eroded cylinders (cylinders where erosions are a fraction of the cylinder length) lead to lower SIF’s. Affecting these values in all cases, of course, are the erosion geometry and depth as well as the crack geometry and depth.

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Ullah, Sati, M. Rehan Khan, Tariq Talha, M. Nasir Bashir, M. Ali Khan e Aurang Zaib. "A Comprehensive Review on Investigation of Sediment Erosion of Pelton Wheel Turbine". Pakistan Journal of Engineering and Technology 5, n. 2 (13 settembre 2022): 152–62. http://dx.doi.org/10.51846/vol5iss2pp152-162.

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Hydro turbines installed at different hydropower plants face the issue of sediment erosion. Sediment erosion is an ambiguous phenomenon influenced by several parameters, including silt concentration, size, jet velocity, diameter, and fluid viscosity. Silt erosion imposes severe issues for hydropower plants, like shutdown and maintenance costs. The hydro turbine efficiency decreases with the increase in sediment erosion and eventually the breakdown of turbine components. Various researchers conducted small-scale experimental bench studies and numerical simulations to analyze the influence of the above-mentioned parameters on silt erosion, but the actual flow conditions are too complex to simulate. Therefore, no such erosion model has been developed to predict exact erosive wear. This paper presents an extensive review of the literature survey on sediment erosive wear of hydro turbines, both the adopted methodology by previous studies and parameters affecting sediment erosion in Pelton turbine are summarized. Based on literature studies, various aspects of erosive wear, parameters influencing it, and its severe effects on efficiency are thoroughly discussed. Appropriate remedial measurements for erosive wear made by multiple researchers, erosion models developed so far, and their measuring accuracy and the future scope of this research study are articulated in detail.

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Koulibaly, Aboubacar Sidiki, Ali Saeidi, Alain Rouleau e Marco Quirion. "Determining the Relevance of Commonly Used Hydraulic Parameters for Representing the Water Erosive Force in Rock Mass Erosion within Dam Spillways". Water 16, n. 9 (28 aprile 2024): 1261. http://dx.doi.org/10.3390/w16091261.

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Spillways are essential control structures in hydroelectric dams for evacuating excess water during periods of high-water flow. These structures are generally excavated within a rock mass, without lining, and they take the form of a flow channel or a plunge pool. Rock mass erosion is an important issue facing engineers when designing unlined spillways. Methods commonly used to analyze this phenomenon are based on the threshold line concept, i.e., the correlation between rock mass resistance and its destruction against the erosive force of water. Multiple indices have been proposed for both rock mass quality and water energy (or erosive force) to assess rock mass erosion. The selection of appropriate indices is critical when evaluating hydraulic erosion. The erosive force of water is often represented by energy dissipation; however, other parameters, including average flow velocity and shear stress at the bottom of the flow channel, may also be relevant. Thus, a critical question is framed: which index best represents the erosive force of water? Here, we develop an approach to assess the applicability of the various indices used to represent the erosive force of water by relying on erosional events at more than 100 study sites. We determine that the most relevant parameters are linked to water pressure, as pressure head and flow velocity better explain the erosive force of the water than shear stress and water dissipation energy.

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28

Seutloali, Khoboso Elizabeth, e Heinrich Reinhard Beckedahl. "A Review Of Road‒Related Soil Erosion: An Assessment Of Causes, Evaluation Techniques And Available Control Measures". Earth Sciences Research Journal 19, n. 1 (30 giugno 2015): 73–80. http://dx.doi.org/10.15446/esrj.v19n1.43841.

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Road construction has increased significantly worldwide in the last decades to meet the demands of the increasing human population and this has led to serious soil erosion problems, the bulk of which is unaccounted for, especially in the developing world. For comprehensive land management decisions and monitoring strategies, a review of work that has been done to assess soil erosion due to roads is critical. This article, therefore, reviews the causes of road‒related soil erosion, assessment methods and available control measures. Specifically, work provides an overview of (i) the linkages between roads and soil erosion; (ii) measurement and prediction of road‒related erosion; and (iii) erosion control and rehabilitation techniques. Literature shows that road construction results in hill-slope profile modification; removal of vegetation cover; as well as the formation of steep slopes that are prone to severe erosion. Furthermore, there is a variety of erosion control measures for controlling road‒related erosion although no study has demonstrated the method that is cost efficient and operational across different landscapes. We are of the view that this study provides guidance in future research on road‒related soil erosion across the developing world were sophisticated monitoring techniques are limited due to resource scarcity for assessing large areas. ResumenLa construcción de carreteras se ha incrementado ampliamente en todo el mundo durante las últimas décadas para cumplir con las demandas de la creciente población humana, lo que ha llevado a serios problemas de erosión de suelos, muchos de los cuales no se previeron, especialmente, en los países en desarrollo. Sobre las decisiones y supervisión de estrategias de un manejo completo del terreno se realizó una revisión al crítico trabajo que se ha hecho para medir la erosión en suelos causados por las carreteras. Por esta razón, este artículo revisa las causas de la erosion relacionada con la construcción de rutas y evalúa los métodos y medidas de control disponibles. Específicamente, este trabajo ofrece una revisión de (a) las relaciones entre las carreteras y la erosión de los suelos; (b) la medida y la predicción de la erosión vinculada a las carreteras, y (c) las técnicas de control de erosión y rehabilitación. La literature muestra que la construcción de carreteras produce modificaciones en el perfil inclinación, remueve la vegetación superficial y aumenta la inclinación en pendientes propensas a erosión severa. Además, existen varias medidas para controlar la erosión causada por la construcción de carreteras, a pesar de que ningún estudio ha demostrado el método que sea más eficiente y operacional para diferentes paisajes. Este estudio guía futuras investigaciones en la erosion causada por la construcción de caminos en los países en desarrollo donde las técnicas de supervisión sofísticas para la evaluación de grandes áreas son limitadas debido a la escasez de recursos.

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29

Anandarajah, A. P., P. Ory, D. Salonen, C. Feng, R. L. Wong e C. T. Ritchlin. "Effect of adalimumab on joint disease: features of patients with psoriatic arthritis detected by magnetic resonance imaging". Annals of the Rheumatic Diseases 69, n. 01 (9 febbraio 2009): 206–9. http://dx.doi.org/10.1136/ard.2008.100149.

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Background:Bone marrow oedema (BMO), synovitis, effusion and joint erosion on magnetic resonance imaging (MRI) may be used as outcome measures in psoriatic arthritis (PsA).Objective:To assess the impact of adalimumab on BMO, synovitis, effusion and erosions in PsA, as measured by MRI.Methods:Fifteen patients with active PsA (⩾3 tender and ⩾3 swollen joints) were enrolled in an open-label pilot study. Each received adalimumab subcutaneously every other week for 24 weeks. MRI was obtained at baseline and 24 weeks.Results:MRI was available for 11 patients, pre and post-therapy. BMO and effusion scores improved markedly after 24 weeks of adalimumab, while no significant change was noted in erosion score. An unanticipated finding, however, was the lack of improvement in the MRI synovitis score.Conclusions:Improvement in BMO and unchanged erosion scores may explain the “anti-erosive” effects of adalimumab in PsA. Persistence of BMO and synovitis on MRI suggests ongoing disease activity and supports the continuation of long-term anti-TNF therapy.

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Lau, Hui-Hsuan, Quan-Bin Jou, Wen-Chu Huang e Tsung-Hsien Su. "Amniotic Membrane Graft in the Management of Complex Vaginal Mesh Erosion". Journal of Clinical Medicine 9, n. 2 (28 gennaio 2020): 356. http://dx.doi.org/10.3390/jcm9020356.

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Vaginal mesh erosion is a devastating complication after pelvic floor mesh surgery and it can be treated conservatively or with surgical revision. However, the management options following a failed primary revision or complex vaginal erosions are very limited. The aim of this study is to describe a novel treatment using an amniotic membrane as an inlay graft for such patients. Eight patients who failed conservative or primary surgical revision were enrolled. The complex erosions included vaginal agglutination, multiple vaginal erosions, recurrent erosions, and mesh cutting through the urethra. We used an amniotic membrane as a graft to cover the vaginal defect after partial excision of the mesh erosion and we describe the technique in this study. There were no intraoperative complications and none of the patients reported any further symptoms at a mean of 27 months follow-up. Only one patient had recurrent erosion, however, the erosion size was narrower and was subsequently successfully repaired. No further vaginal mesh erosions were noted in the other patients who all had good functional recovery. The use of an amniotic graft can be an economic and alternative method in the management of complex vaginal mesh erosions.

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31

Ali, Muhammad, Saima Attiq, Sayed Nusrat Raza, Abdul Hakim, Shakeel Ahmed, Shaukat Ali, Farhan Akbar e Syed Waqar Abbas. "FREQUENCY OF BONE EROSION ON COMPUTERIZED TOMOGRAPGHY SCAN IN ALLERGIC FUNGAL RHINOSINUSITIS". PAFMJ 71, Suppl-3 (30 dicembre 2021): S428–31. http://dx.doi.org/10.51253/pafmj.v1i1.4159.

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Objective: To analyze the frequency and sites of bone erosion on computerized tomograghy scan in Allergic Fungal Rhinosinustis in Pakistan. Study Design: Retrospective observational study. Place and Duration of Study: Department of ENT, Combined Military Hospital Lahore, Malir Karachi and Rawalpindi, from Jan 2010 to Dec 2019. Methodology: Total 230 cases of Allergic Fungal Rhinosinusitis were screened, out of which 85 patients having bone erosions on computerized tomograpghy scan were included in the study. Bone erosion in different paranasal sinuses and their sub sites were evaluated. Depending upon the number of bone erosion, patients were divided into three categories as mild, moderate and severe. Those having erosion at a single site were labelled as mild, those with two sub sites of erosion as moderate and those with more than two subsites of erosion were labelled as severe cases. Results: Detailed evaluation of computerized tomography scan of paranasal sinuses revealed bone erosion in 85/230 (36.9%) cases. Mean affected age was 23.96 ± 12.71 years. There were 52 (61.1%) males and 33 (38.9%) females. Ethmoid sinus was the most commonly involved sinus to have bone erosions 55 (38.19%) followed by maxillary sinus 38 (26.38%) then sphenoid sinus 27 (18.75%) and lastly frontal sinus 24 (16.6%). Out of 85 patients 48 (56.1%) were having mild, 22 (25.8%) moderate and 15 (17.6%) had severe disease. Conclusion: Allergic Fungal Rhinosinusitis has high frequency of bone erosion. Computerized tomography scan is an important and effective investigation in finding these bony erosions and ethmoid sinus is the.....

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32

Ganti, Vamsi, Christoph von Hagke, Dirk Scherler, Michael P. Lamb, Woodward W. Fischer e Jean-Philippe Avouac. "Time scale bias in erosion rates of glaciated landscapes". Science Advances 2, n. 10 (ottobre 2016): e1600204. http://dx.doi.org/10.1126/sciadv.1600204.

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Deciphering erosion rates over geologic time is fundamental for understanding the interplay between climate, tectonic, and erosional processes. Existing techniques integrate erosion over different time scales, and direct comparison of such rates is routinely done in earth science. On the basis of a global compilation, we show that erosion rate estimates in glaciated landscapes may be affected by a systematic averaging bias that produces higher estimated erosion rates toward the present, which do not reflect straightforward changes in erosion rates through time. This trend can result from a heavy-tailed distribution of erosional hiatuses (that is, time periods where no or relatively slow erosion occurs). We argue that such a distribution can result from the intermittency of erosional processes in glaciated landscapes that are tightly coupled to climate variability from decadal to millennial time scales. In contrast, we find no evidence for a time scale bias in spatially averaged erosion rates of landscapes dominated by river incision. We discuss the implications of our findings in the context of the proposed coupling between climate and tectonics, and interpreting erosion rate estimates with different averaging time scales through geologic time.

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33

Frank, F., B. W. McArdell, C. Huggel e A. Vieli. "The importance of erosion for debris flow runout modelling from applications to the Swiss Alps". Natural Hazards and Earth System Sciences Discussions 3, n. 4 (10 aprile 2015): 2379–417. http://dx.doi.org/10.5194/nhessd-3-2379-2015.

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Abstract. This study describes an investigation of channel-bed erosion of sediment by debris flows. An erosion model, developed using field data from debris flows at the Illgraben catchment, Switzerland, was incorporated into the existing RAMMS debris-flow model, which solves the 2-D shallow-water equations for granular flows. In the erosion model, the relationship between maximum shear stress and measured erosion is used to determine the maximum potential erosion depth. Additionally, the maximum rate of erosion, measured at the same field site, is used to constrain the erosion rate. The model predicts plausible erosion values in comparison with field data from highly erosive debris flow events at the Spreitgraben torrent channel, Switzerland in 2010, without any adjustment to the coefficients in the erosion model. We find that by including channel erosion in runout models a more realistic flow pattern is produced than in simulations where entrainment is not included. In detail, simulations without channel bed erosion show more lateral outflow from the channel where it has not been observed in the field. Therefore the erosion model may be especially useful for practical applications such as hazard analysis and mapping, as well as scientific case studies of erosive debris flows.

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34

Hawkey, C. J., A. B. Hawthorne, N. Hudson, A. T. Cole, Y. R. Mahida e T. K. Daneshmend. "Separation of the impairment of haemostasis by aspirin from mucosal injury in the human stomach". Clinical Science 81, s25 (1 ottobre 1991): 565–73. http://dx.doi.org/10.1042/cs0810565.

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1. An increasing body of data suggests that the anti-haemostatic as well as the ulcerogenic actions of aspirin and other non-steroidal anti-inflammatory drugs may be operative when patients present with haematemesis and melaena. 2. We therefore developed methods to allow separate evaluation of the erosive and anti-haemostatic actions of aspirin in the human gastric mucosa. Volunteer subjects took 300 mg of aspirin daily in the morning or 600 mg of aspirin four times a day for 5 days under blinded randomized conditions. Changes in spontaneous gastric microbleeding, endoscopic signs of injury, spontaneous bleeding per gastric erosion, biopsy-induced bleeding and eicosanoids were studied. 3. Both doses of aspirin significantly inhibited gastric mucosal synthesis of prostaglandin E2 and reduced the serum thromboxane concentration. Erosions developed and regressed rapidly; compared with baseline 300 mg of aspirin daily in the morning caused substantial numbers of gastric erosions to develop (mean 5.3, 95% confidence limits 2.7–10.2) but this was significantly less than that caused by 600 mg of aspirin four times a day (10.9, 7.2–16.5, P < 0.05). The presence of erosions was associated with enhanced spontaneous bleeding, but only during aspirin administration. 4. Aspirin significantly increased bleeding induced by mucosal biopsy and was associated with significant enhancements in the rate of bleeding per gastric erosion. Bleeding rate per erosion but not biopsy-induced bleeding showed a significant dose-related increase with 600 mg of aspirin four times a day. Enteric coating reduced endoscopic signs of injury, but did not affect the impaired haemostasis caused by aspirin. 5. We conclude that aspirin can be shown to have both erosive and anti-haemostatic effects in the human stomach. Each can be evaluated separately in our model system. Both are potential therapeutic targets for the prevention of major upper-gastrointestinal bleeding caused by aspirin and probably other non-steroidal antiinflammatory drugs.

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Lu, Pingda, Bin Zhang, Chenfeng Wang, Mengyun Liu e Xiaoping Wang. "Erosion Gully Networks Extraction Based on InSAR Refined Digital Elevation Model and Relative Elevation Algorithm—A Case Study in Huangfuchuan Basin, Northern Loess Plateau, China". Remote Sensing 16, n. 5 (6 marzo 2024): 921. http://dx.doi.org/10.3390/rs16050921.

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The time-effective mapping of erosion gullies is crucial for monitoring and early detection of developing erosional progression. However, current methods face challenges in obtaining large-scale erosion gully networks rapidly due to limitations in data availability and computational complexity. This study developed a rapid method for extracting erosion gully networks by integrating interferometric synthetic aperture radar (InSAR) and the relative elevation algorithm (REA) within the Huangfuchuan Basin, a case basin in the northern Loess Plateau, China. Validation in the study area demonstrated that the proposed method achieved an F1 score of 81.94%, representing a 9.77% improvement over that of the reference ASTER GDEM. The method successfully detected small reliefs of erosion gullies using the InSAR-refined DEM. The accuracy of extraction varied depending on the characteristics of the gullies in different locations. The F1 score showed a positive correlation with gully depth (R2 = 0.62), while the fragmented gully heads presented a higher potential of being missed due to the resolution effect. The extraction results provided insights into the erosion gully networks in the case study area. A total of approximately 28,000 gullies were identified, exhibiting pinnate and trellis patterns. Most of the gullies had notable intersecting angles exceeding 60°. The basin’s average depth was 64 m, with the deepest gully being 140 m deep. Surface fragmentation indicated moderate erosive activity, with the southeastern loess region showing more severe erosion than the Pisha sandstone-dominated central and northwestern regions. The method described in this study offers a rapid approach to map gullies, streamlining the workflow of erosion gully extraction and enabling efficiently targeted interventions for erosion control efforts. Its practical applicability and potential to leverage open-source data make it accessible for broader application in similar regions facing erosion challenges.

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36

Tarley Ferreira Nascimento, Diego, Patrícia De Araújo Romão e Maurício Martines Sales. "Erosividade e erodibilidade ao longo de dutovia cortando os estados de Minas Gerais e Goiás - Brasil". Ateliê Geográfico 12, n. 1 (3 agosto 2018): 97–117. http://dx.doi.org/10.5216/ag.v12i1.46152.

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Resumo Apresenta-se o mapeamento da erosividade e da erodibilidade ao longo da dutovia OSBRA, que corta vários municípios de Minas Gerais e Goiás. Para o mapeamento da erosividade, foram calculados os índices de erosividade de cada estação meteorológicas nas proximidades da área estudada. Para o mapeamento da erodibilidade, foram agrupadas categorias de solos com comportamentos semelhantes quanto à resistência a processos erosivos e posteriormente foi classificada sua suscetibilidade erosiva. Com base nos mapeamentos da erosividade e da erodibilidade foi possível identificar áreas com maior suscetibilidade a processos erosivos. Levantamento de 85 pontos de erosão, cadastrados em campo, foram confrontados com os mapas de erodibilidade e erosividade, resultando em uma grande coerência entre previsão e ocorrências em campo. O mapeamento apresentado poderá ser usado como critério de decisão sobre qual área deve ter maior monitoramento do que outras, visando a segurança da faixa do duto e de fazendas vizinhas. Palavras-Chave: Erosividade; Erodibilidade; Processos Erosivos Abstract This paper presents the erosivity and erodibility mapping along the pipeline OSBRA, which cut the states of Minas Gerais and Goiás. For mapping the erosivity, the erosivity indices were calculated to each weather station near the studied area. To map the erodibility, soils were grouped in classes considering similar resistance to erosion processes, and their erosive susceptibility were subsequently classified. Based on the erosivity and erodibility mappings, areas with greater susceptibility to erosion processes were identified. A collection of 85 points of erosions, registered on the field, were compared with the maps of erodibility and erosivity and resulted in a good agreement between predictions and events in the field. The presented mapping can be used as a decision criterion on which area should have a more intensive monitoring than others, seeking the safety of the pipeline and neighboring farms. Keywords: Erosivity; Erodibility; Erosion processes Resumen Se presenta el mapeo de la erosividad y de la erodibilidad a lo largo de la tubería OSBRA, que corta varios municipios de Minas Gerais y de Goiás. Para mapear la erosividad se calcularon los índices de erosividad de cada estación meteorológica, en las proximidades del área observada. Para mapear la erodibilidad se agruparon categorías de suelos similares, en cuanto a su resistencia a los procesos erosivos. Posteriormente, se clasificó su susceptibilidad erosiva. Considerando los mapeos de erosividad y erodibilidad, se identificaron áreas más susceptibles que otras a los procesos erosivos. Observaciones levantadas a partir de 85 puntos de erosión registrados en campo, confrontadas con los mapas de erodibilidad y erosividad, mostraron coherencia entre la previsión y los datos de campo. El mapeo presentado puede utilizarse para definir cuáles son las áreas que requieren más control y vigilancia, teniendo en cuenta la seguridad de la zona a lo largo de las tuberías, así como la de las haciendas vecinas. Palabras Clave: Erosividad; Erodibilidad; Mecanismo de erosión

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37

Chawhuaveang, Darren Dhananthat, Ollie Yiru Yu, Iris Xiaoxue Yin, Walter Yu Hang Lam e Chun Hung Chu. "Topical Agents for Nonrestorative Management of Dental Erosion: A Narrative Review". Healthcare 10, n. 8 (28 luglio 2022): 1413. http://dx.doi.org/10.3390/healthcare10081413.

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A nonrestorative approach to the management of dental erosion is the foremost option: controlling dental erosion. The objectives of this study are to provide an overview and to summarise the effects and properties of topical anti-erosive agents as a nonrestorative treatment of dental erosion. A literature search was conducted on five databases of peer-reviewed literature—Cochrane Library, EMBASE, PubMed, Scopus and Web of Science—to recruit articles published between 1 January 2000 and 31 December 2021. The literature search identified 812 studies; 95 studies were included. Topical anti-erosive agents can be broadly categorised as fluorides, calcium phosphate-based agents, organic compounds and other anti-erosive agents. In the presence of saliva, fluorides promote the formation of fluorapatite on teeth through remineralisation. Calcium phosphate-based agents supply the necessary minerals that are lost due to the acid challenge of erosion. Some organic compounds and other anti-erosive agents prevent or control dental erosion by forming a protective layer on the tooth surface, by modifying salivary pellicle or by inhibiting the proteolytic activity of dentine collagenases. Topical anti-erosive agents are promising in managing dental erosion. However, current evidence shows inconsistent or limited results for supporting the use of these agents in clinical settings.

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Kong, Bo, e Huan Yu. "Estimation Model of Soil Freeze-Thaw Erosion in Silingco Watershed Wetland of Northern Tibet". Scientific World Journal 2013 (2013): 1–7. http://dx.doi.org/10.1155/2013/636521.

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The freeze-thaw (FT) erosion is a type of soil erosion like water erosion and wind erosion. Limited by many factors, the grading evaluation of soil FT erosion quantities is not well studied. Based on the comprehensive analysis of the evaluation indices of soil FT erosion, we for the first time utilized the sensitivity of microwave remote sensing technology to soil moisture for identification of FT state. We established an estimation model suitable to evaluate the soil FT erosion quantity in Silingco watershed wetland of Northern Tibet using weighted summation method of six impact factors including the annual FT cycle days, average diurnal FT phase-changed water content, average annual precipitation, slope, aspect, and vegetation coverage. Finally, with the support of GIS, we classified soil FT erosion quantity in Silingco watershed wetland. The results showed that soil FT erosion are distributed in broad areas of Silingco watershed wetland. Different soil FT erosions with different intensities have evidently different spatial and geographical distributions.

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Liu, Jun, Xuyang Wang, Li Zhang, Zhongling Guo, Chunping Chang, Heqiang Du, Haibing Wang, Rende Wang, Jifeng Li e Qing Li. "Regional Potential Wind Erosion Simulation Using Different Models in the Agro-Pastoral Ecotone of Northern China". International Journal of Environmental Research and Public Health 19, n. 15 (3 agosto 2022): 9538. http://dx.doi.org/10.3390/ijerph19159538.

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Abstract (sommario):

Wind erosion is crucial for assessing regional ecosystem services and sustainable development. The Agro-Pastoral Ecotone of northern China (APEC) is a typical region undergoing wind erosion and soil degradation. In this study, the National Wind Erosion Survey Model of China, the Integrated Wind Erosion Modeling System, and the regional versions of the Revised Wind Erosion Equation and Wind Erosion Prediction System were used to evaluate the regional potential wind erosion of the APEC during 2000 and 2012. The results showed that the potential wind erosion predicted by National Wind Erosion Survey Model of China (NWESMC), Revised Wind Erosion Equation (RWEQ), Wind Erosion Prediction System (WEPS), and Integrated Wind Erosion Modeling System (IWEMS) were significantly related to the observed wind erosion collected from published literature, but the observed data were generally smaller than the predicted values. The average potential wind erosions were 12.58, 25.87, 52.63, and 58.72 t hm−2 a−1 for NWESMC, RWEQ, WEPS, and IWEMS, respectively, while the spatial pattern and temporal trend of annual potential wind erosion were similar for different wind erosion models. Wind speed, soil moisture, and vegetation coverage were the dominant factors affecting regional wind erosion estimation. These results highlight that it is necessary to comprehensively calibrate and validate the selected wind erosion models. A long-term standard wind erosion monitoring network is urgently required. This study can serve as a useful reference for improving wind erosion models.

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40

Blinkov, Ivan. "The Balkans - the most erosive part of Europe?" Bulletin of the Faculty of Forestry, n. 111 (2015): 9–20. http://dx.doi.org/10.2298/gsf1511009b.

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Abstract (sommario):

Soil erosion has been occurring over the geological time. Inappropriate human activities accelerate this process. Soil erosion by water is a widespread problem throughout Europe. The South and Southeast regions of Europe are significantly prone to water erosion. In parts of the region, erosion has reached a stage of irreversibility and in some places erosion has practically ceased because there is no soil left. Scientists from the Balkan countries faced with the erosion problem for years, paid significant attention to solving problems with erosion. The aim of this study is to compare the results of water erosion intensity in the Balkan countries with other European countries. The basic methodological approach in this paper is an analysis of secondary data, using the method of ?content analyses? of various data sources. Inductive and deductive qualitative analysis was used and finally the method of ?comparative analysis? is applied too. Through the analysis of national researches, it was estimated that erosion intensity in Balkan countries is 548 m3km-2 (similar to 5.48 tha-1) and the total amount of annual produced erosive material is 419.9 *106 m3. The mean European average annual erosion intensity is 3.13tha-1. The most erosive countries in Europe are the Balkan countries, Albania and Montenegro where the mean annual intensity of erosion is > 10 tha-1.

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41

Muhammed, Khalil, e Aram Dawood Abbas. "The Estimation of the Amount of Water Erosion at Qalachwalan Basin by Gavrivolic Model". Journal of University of Raparin 11, n. 2 (9 luglio 2024): 87–120. http://dx.doi.org/10.26750/vol(11).no(2).paper4.

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Qalachwalan basin is important agricultural and it is one of the main water resources for Slemani city. The basin contains useful natural resources that are conducive to agricultural development. As the area is a hill country, Gavrilovic model was chosen to get the size and amount of water erosion to determine the erosion risks that the basin is facing. This research was conducted based on Gavrilovic (EPM) model using (RS & GIS) to determine the level, amount, and size of water erosion of Qalachwalan basin. We found out that, through the research, the slopes that are in the direction of the estuaries face water erosion much more due to the form of the basin in its creation, which has many slopes and little vegetation on the cliffs that are a main cause of the speedy runoff. Also, poor planning to confront or reduce the risks of flood which increases the erosions. The erosion estimated based on Gavrilovic model between very weak erosion at less than (100 m3/km2/year) and very strong erosion at (5000 – 20000 m3/km2/year). The basin generally lies in the circle of moderate water erosion at (1230 m3/km2/year). Therefore, for the secondary basins (e.g. Jogasur, Mawakan, and estuary) the erosion based on Gavrilovic model was high consecutively in this way (1720, 2584 and 4356 m3/km2/year). Our results very impotent for local government stockholders to establishment new dams in cliffs areas for agriculture and determine life cycle of these dams in this areas, and find new solution to reduce soil erosions in near future.

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Isomoto, Yoshinori. "Erosion and Erosion-Corrosion". Zairyo-to-Kankyo 57, n. 1 (2008): 15–21. http://dx.doi.org/10.3323/jcorr.57.15.

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43

Zheng, Hong, Xi-An Li, Ya-Hong Deng, Jie Li e Feng Wen. "Physical Modelling of Hydraulic Erosion Rates on Loess Slopes". Water 14, n. 9 (21 aprile 2022): 1344. http://dx.doi.org/10.3390/w14091344.

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Abstract (sommario):

Soil erosion is a major environmental problem of global concern. In the Loess Plateau region of China, erosion of loess slopes is one of the major modes of soil erosion, causing serious erosional problems. Most current studies of loess slope erosion use qualitative analyses from field investigations, while quantitative analyses from experimental physical simulations are relatively rare. This paper takes slope erosion, which is the most typical mode of loess erosion, as the starting point and investigates the hydraulic erosion process for different initial states using small-scale physical simulations. The slope erosion process can be generalised into two stages: rapid erosion, and slow and uniform erosion. Results of the physical simulations suggested that the initial dry density is negatively correlated with the erosion rate, but the initial water content is positively correlated with the erosion rate. The results of the study are not only of practical significance for the prevention and control of soil erosion on loess slopes, but also of theoretical significance, as they reveal the development of slope gully erosion.

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Lu, Zhen Lin, Zhi Guo Xing, Yong Xin Zhou e Hui Xie. "Study on the Erosion Wear Properties of Reaction-Bonded SiC". Materials Science Forum 658 (luglio 2010): 364–67. http://dx.doi.org/10.4028/www.scientific.net/msf.658.364.

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The erosion wear behaviors and mechanism of reaction-bonded silicon carbide were studied by jet erosion wear tester and SEM surface analysis in this paper. The results show that the erosive wear rate of reaction-bonded silicon carbide would be increased and then decreased with the increase of erosion angle and would reach the peak value when the erosion angle is at 60º. It is lower than that of high chromium cast iron at all of test erosion angle. The reaction bonded SiC will show better erosion wear behaviors when the SiC particle size matches with the amount of free silicon. The erosion wear mechanism of reaction bonded SiC was analyzed.

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45

Khan, Muhammad Arif, Muhammad Saleem, Adnan Saleem Umar, Ali Husnain Sheikh, Andleeb Iqbal, Rabia Javed e Khurram Shahzad. "An Analysis of the Occurrence of Bone Erosion on Computerized Tomography Scans in Allergic Fungal Rhinosinusitis". Pakistan Journal of Medical and Health Sciences 17, n. 4 (26 maggio 2023): 652–54. http://dx.doi.org/10.53350/pjmhs2023174652.

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Objective: Bone erosion on a CT scan may be an indication of osteoarthritis, rheumatoid arthritis, or bone infections, among other diseases. Tumors and other bone conditions may also be to blame. A doctor would need to analyze the CT scan and maybe do other tests or imaging investigations to identify the source of bone degradation. The study's goal is to examine the prevalence and locations of bone erosion on computed tomography scans in Pakistani patients with allergic fungus rhinosinusitis. Methods: This retrospective observational study was conducted at The study was conducted in PAC Hospital Kamra, Pakistan, between January 2013 and December 2022. 85 of the patients who had bone erosions on a computed tomography scan out of a total of 230 instances of allergic fungal rhinosinusitis were included in the research. Evaluation of bone erosion in various paranasal sinuses and their sub-sites. Patients were categorized into three groups based on how much bone erosion they had: mild, moderate, and severe. Mild instances were those with erosion at a single site, moderate cases had erosion at two subsites, and severe cases had erosion at more than two subsites. Results: In 85 (36.9%) of the patients, bone erosion was discovered after a thorough analysis of the computed tomography scan of the paranasal sinuses. The average impacted age was 23.96 ± 12.71. There were 33 women and 52 men, or 61.1% of the total. The ethmoid sinus was the sinus that had bone erosions the most often. Frontal sinus 24 (16.6%), maxillary sinus 55 (38.19%), sphenoid sinus 27 (18.75%), and maxillary sinus 38 (26.38%) are listed in that order. Out of 85 patients, 15 (17.6%) had a severe illness, 22 (25.8%) had moderate disease, and 48 (56.1%) had mild disease. Implication: The radiological evaluation of illness, regardless of the method and scoring system employed, is crucial because it allows the otolaryngologist and the radiologist to stratify the severity of the disease in instances of AFRS and aids in clinical evaluation and the avoidance of problems Conclusions: Bone erosion occurs frequently in allergic fungal rhinosinusitis. The ethmoid sinus is the most frequently affected paranasal sinus in terms of bone erosion, and computerized tomography (CT) scan is a crucial and efficient inquiry in detecting these erosions. Keywords: rhinosinusitis, bone erosion, sinusitis, radiological evaluation

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46

Zhizhong, Gao, Han Peichen, Liu Qiong, Guo Hao, Liang Hongye e Du Ping. "Study on erosion-reducing additives and erosion inhibition principle for R2 high energy propellant". Journal of Physics: Conference Series 2478, n. 3 (1 giugno 2023): 032016. http://dx.doi.org/10.1088/1742-6596/2478/3/032016.

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Abstract In view of the serious erosion problem of the gun barrel with the R2 high-energy propellant, an erosion tube device method was adopted, and silane organic substances, silicate inorganic substances, titanium dioxide nanoparticles and paraffin wax were selected as erosion-reducing additives. The effect of different erosion-reducing additives on the erosive property of R2 propellant was investigated by means of external addition. The erosion inhibition principle was also briefly investigated by scanning electron microscope and energy dispersive X-ray spectroscopy. The results show that paraffin wax has excellent ability to improve gun barrel erosion resistance, the erosion-reducing efficiency can reach up to 31.2%, the erosion-reducing efficiency of silanes is the next most effective, and silicate is poor.

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47

Wahab, Juyana A., Mariyam Jameelah Ghazali, Mochd Nazree B. Derman e Yuichi Otsuka. "Erosive Wear Characteristics of Laser Textured Alumina-Based Coatings for Marine Applications". Solid State Phenomena 280 (agosto 2018): 96–101. http://dx.doi.org/10.4028/www.scientific.net/ssp.280.96.

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Micro-groove textured surface of alumina-based ceramic coating is successfully fabricated via laser surface texturing (LST) method. The fabrication of textured surface is aimed to improve the resistivity of components against erosive wear. In this study, a slurry pot testing is conducted to investigate erosion damage on the surface of the textured alumina-based coating. The erosive wear rate of the specimens is determined and the surface morphology of the eroded surface is examined using an SEM. From the results, it is found that the erosion damage of textured coatings is dependent on the impact angles of SiO2particles. The erosion wear mechanism is found to be varied with the formation of the micro-groove textured coatings. A significant decrease of 45 % in the erosion rate proved that the occurrence of an improved erosion resistance.

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Xie, Jing Pei, Ai Qin Wang, Wen Yan Wang, Ji Wen Li e Luo Li Li. "Erosion Wear Behaviors of Low Chromium Cast Iron Containing Nickel". Advanced Materials Research 233-235 (maggio 2011): 2984–87. http://dx.doi.org/10.4028/www.scientific.net/amr.233-235.2984.

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The erosion wear experiments of low-chromium cast iron containing nickel were done by MCF-30 Erosion Abrasion Experimental Machine. The structure and surface morphology after erosive wear were analyzed by SEM and XRD. The results indicated that the distribution of carbide was reticular after tempering at 250and oil quenching at 960. The maximal erosion wear rate was appeared at 60 °erosion angle, high acid corrosion media have great influence on the abrasion resistance of experimental material and corrosion effects almost had no influence on the abrasion resistance of experimental material in the weak acid environment of pH≥3. The erosive wear mechanism of the experimental material was studied.

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Du, Jun, Ping Zhang, Jun Jun Zhao e Zhi Hai Cai. "Erosion-Resistant PVD ZrAlCuN Coating for Titanium Alloy". Advanced Materials Research 150-151 (ottobre 2010): 51–55. http://dx.doi.org/10.4028/www.scientific.net/amr.150-151.51.

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Titanium alloys are susceptible to sand erosion, hard zirconium nitride coatings have been deposited onto titanium alloys by Physical vapor deposition (PVD) in order to improve erosion resistance. Al and Cu were added into ZrN coatings to strength and toughing the coating. The microstructure and mechanical properties of ZrAlCuN coating were studied. Erosion tests were conducted to evaluate anti-erosion ability. Erosion rates were measured and characteristic damage features were identified on the surface of eroded specimens. The mechanisms of erosion are discussed in order to explain the promising performance of materials in erosive conditions. It was found that there is an significant increase of erosion resistance because of the increase of hardness and toughness.

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50

Mishvelov, E. G., A. I. Kornienko, N. O. Guseynova, E. E. Tikhonov e E. N. Pavlenko. "Morphometric characteristics of the relief and assessment of erosional hazards of the Kalaus River basin, Russia, based on digital modelling". South of Russia: ecology, development 19, n. 2 (22 luglio 2024): 147–59. http://dx.doi.org/10.18470/1992-1098-2024-2-13.

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In this work, the main goal was to analyse the erosional hazards within the boundaries of the Kalaus River catchment area.The paper analyses the erosive state of the region's lands, for which industry and cadastral maps, a digital elevation model and satellite images were used. Official data of ministries and departments were used. Geographic information systems – QGIS and SAGA GIS – served as the basis for modelling. The article presents the results of GIS modeling of erosional hazards in the territory of the Kalaus River basin. Based on the (DEM) SRTM digital elevation model, the basic morphometric indicators of the relief were calculated: steepness of the slopes and vertical and horizontal dissection of the relief. Based on morphometric indicators, an integral calculation of the energy of relief and erosion hazard was carried out and a series of relevant thematic maps was created. The values of slope steepness obtained within the boundaries of the basin range from 0° to 51° with average values of 2.5°. The horizontal dissection varies in the range from 0 to 0.84 km/km2, and the erosion bases are characterized by a range of values from – 15.0 to 248.6 m, with an average value of 33.0 m. The formation of the erosional potential of the basin’s relief is facilitated by the location of a significant part of the region on the spurs of the Stavropol Upland, which have widely developed slopes. Based on the calculated raster of the integral energy index of the relief, 3 categories of erosional hazard are identified. Most of the basin of the Kalaus River (58.4 %) is characterised by a low erosion hazard, another 39.0 % of the territory presents an average erosion hazard, and the remaining 2.9 % belongs to territories with a strong erosion hazard. The classification of relief surface shapes based on the Iwahashi and Pike method, which was carried out on the basis of a DEM, shows a much greater prevalence of steep slopes with high convexity in the southern part of the Kalaus River basin.The identified features of the level of erosional hazard of the lands of the Kalaus River basin are recommended to be taken into account in preinvestment, pre‐design and urban project planning of the territories of administrative units located within the boundaries of the basin. Despite the fact that the results of GIS analysis cannot completely replace field erosion surveys, their value as a tool for planning rational land use is obvious. The results of the work can be used to carry out a similar assessment in other regions, primarily in the organisation of agricultural production.

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