Erosion Damage Research Articles

Erosive Damages of the Gastroduodenal Zone in Servicemen: Clinical and Pharmacoeconomic Aspects

Erosive and ulcerative lesions of the gastroduodenal zone in military personnel occupy one of the key places in the structure of the general pathology of internal organs. They significantly reduce the quality of life, affect the work capacity and personal life. Risk factors for their development is H. pylori infection, stress, severe trauma, certain drugs, and smoking. Delay in diagnosis and treatment can have negative consequences. The objective: to analyze the disease course, determine the clinical and pharmacoeconomic efficacy of the combined bismuth-containing and acid-suppressive treatment regimens for erosive gastroduodenal lesions in military personnel. Materials and methods. The study was designed as analyze of 40 medical charts of military personnel, who underwent treatment of the non-HP-associated erosive lesions of the gastroduodenal zone at the National Military Medical Clinical Center (NMMCC) «Main Military Clinical Hospital». The study used clinical, bibliographic, statistical, pharmacoeconomic analysis together with the assessment of the quality of life by SF-36 questionnaire. Results. It was found that the treatment regimen with use of rabeprazole and colloidal bismuth subcitrate has better clinical effectiveness (85% of patients recovered in 14 days of treatment compared to the group with omeprazole monotherapy, where the same indicator was 60%). Also, this scheme has a higher cost-utility (by 48%) and cost efficiency (by 56%) at a lower cost of treatment (by 17%). Conclusion. The treatment regimen for non-HP-associated erosive lesions of the gastroduodenal zone based on rabeprazole and colloidal bismuth subcitrate is more expedient from the point of view of clinical effectiveness and pharmacoeconomic feasibility compared to the regimen based on omeprazole alone and its use can improve the pharmacoeconomic results and rationality of budget funds use.

Propionibacterium freudenreichii Inhibits RANKL-Induced Osteoclast Differentiation and Ameliorates Rheumatoid Arthritis in Collagen-Induced Arthritis Mice.

Osteoclast differentiation is crucial for bone absorption, and osteoclasts are involved in bone destruction in rheumatoid arthritis (RA). Dairy Propionibacterium freudenreichii is used as a cheese starter and possesses prebiotic and postbiotic properties. It is known to stimulate the growth of bifidobacteria and produces valuable metabolites, such as vitamin B12 and propionic acid. However, limited information is available on the beneficial effects of P. freudenreichii on human disease. Herein, we aimed to investigate the inhibitory effect of P. freudenreichii MJ2 (MJ2) isolated from raw milk on osteoclast differentiation and evaluate the improvement in RA. The murine macrophage cell line, RAW 264.7, and a collagen-induced arthritis (CIA) mouse model were used to perform in vitro and in vivo studies, respectively. Heat-killed P. freudenreichii MJ2 (hkMJ2)-treated cells significantly inhibited RANKL-induced osteoclast differentiation and TRAP activity. HkMJ2-treated cells exhibited significantly decreased expression of genes and proteins related to RANKL-induced osteoclast differentiation. MJ2 administration decreased the arthritic score in the CIA mouse model. Live and dead MJ2 inhibited bone loss and afforded protection against bone erosion and joint damage in CIA mice. MJ2 decreased the levels of collagen-specific antibodies and inflammatory cytokines and the expression of osteoclast differentiation-related genes and proteins in CIA mice. Interestingly, live and dead MJ2 showed similar RA improvement effects in CIA mice. In conclusion, P. freudenreichii MJ2 inhibited osteoclast differentiation by inhibiting the NF-κB signaling pathway and ameliorated CIA.

Spatial variability of soil erodibility in pastures and forest areas in the municipality of Porto Velho, Rondônia

“Erodibility” is a characteristic of the soil that represents the susceptibility with which its particles from the most superficial layer are taken and transported to lower places by erosive agents, causing environmental and economic damages. This work estimated soil erodibility in pastures and forest areas in the municipality of Porto Velho-Rondônia. In the field, three areas with different types of vegetation were selected, one with brachiaria, another with mombaça grass, and a third in native forest. In areas with pastures, a sampling mesh of equal sizes was outlined (90 m x 60 m), and in the forested area an approximate sampling mesh (90 m x 50 m), with a regular spacing of 10 m between the samples points for both areas. The sampling was done at the crossing points of the mesh at a depth of 0.0-0.2 m, composing 70 sample points in the areas with pastures and 60 sample points in the forest area, totaling 200 samples. Then, laboratory analyzes were carried out to determine the texture followed by the fractionation of the sand, and the organic carbon followed by the estimate of the organic matter of the soil. The erodibility factors were calculated using indirect prediction models, and then, univariate, geostatistical and multivariate techniques were applied. The pastures’ environments differed from the forest environment. However, the mombaça grass area functions as an intermediate environment between the forest and the brachiaria, being closer to the forest environment.
 Keywords: erodibility, factors, kriging, principal components.

Dactylitis is an indicator of a more severe phenotype independently associated with greater SJC, CRP, ultrasound synovitis and erosive damage in DMARD-naive early psoriatic arthritis

ObjectiveTo characterise the impact of dactylitis in disease-modifying antirheumatic drug (DMARD)-naive early psoriatic arthritis (PsA).MethodsPatients with early PsA meeting the classification criteria for PsA (CASPAR) were recruited. Clinical outcomes were...

Laser engineered net shape repair of Ni-base superalloy Mar-M247

Laser engineered net shape (LENS) technology was applied for repairing Mar-M247, and the influence of the Mar-M247 microstructure and LENS process parameters on the repair weldability was investigated. The results show that the cracking susceptibility of Mar-M247 was very high and cracking was initiated in the Mar-M247 heat-affected zone (HAZ) and then propagated into the LENS deposit. The HAZ cracking was quite sensitive to the presence of carbides in the base material, with even small quantities of carbide leading to the initiation of cracking in the deposit, which can be greatly suppressed by optimizing LENS process parameters but not eliminated. In addition, solution annealing of the as-cast base metal prior to repair significantly reduced the cracking susceptibility. Cracking was further suppressed by the aging treatment. Under the complete homogenized Mar-M247 blade, the simulated tip erosion damage was successfully repaired without cracking by optimizing LENS process parameters.

In-situ SEM investigation on stress-induced microstructure evolution of austenitic stainless steels subjected to cavitation erosion and cavitation erosion-corrosion

This study investigated the effect of stress on the microstructure evolution of austenitic stainless steels (316L SS and 304 SS) subjected to cavitation erosion and cavitation erosion-corrosion. Results show that continuous accumulation of stress of austenitic stainless steels at the early stage of cavitation erosion was observed from the samples tested in deionised water (DIW) but not in artificial seawater (ASW), which is due to stress release induced by ASW. In addition, a stress-induced phase transformation from austenite to martensite during the cavitation erosion tests in both DIW and ASW was observed in 304 SS, but not in 316 SS. Furthermore, primary cavitation craters formed during the cavitation erosion were not expanded directly but shrank first and then expanded due to re-accumulation of stress. More importantly, this study reports for the first time that pre-existing pores are not initiation points of cavitation erosion damage, possibly because of the ductility of austenitic stainless steels, which resulted in continuous shrinkage of the pores caused by the accumulated stress. Our findings provide new insights into understanding the failure mechanisms of austenitic stainless steels subjected to cavitation erosion, which will inform the development of high-performance cavitation erosion-resistant materials.

Prediction and experimental evaluation of the threshold velocity in water droplet erosion

Gradual wear of materials due to repetitive high-speed impacts of water droplets is a serious reliability concern for blades of gas, steam, and wind turbines. The phenomenon is commonly referred to as water droplet erosion (WDE). Analogous to fatigue, WDE has an endurance regime, called threshold velocity, where material resists erosion damage for prolonged exposure. The ability to predict the threshold velocity from material properties is crucial for the prevention of WDE phenomenon. In the past decades, developing models to predict the threshold velocity have been attempted. This has resulted in one semi-analytical model and several empirical equations, all of which exhibited limitations in applicability and physical meaning. Drawing on previous attempts along with contemporary theoretical and experimental investigations of WDE phenomenon, we report on the prediction of threshold velocity using an analytical model. The developed model represents the WDE threshold velocity using materials properties and impact conditions. A procedure to experimentally evaluate the threshold velocity in rotating erosion test devices has also been developed. The developed model predicted threshold velocities with higher accuracy than the previous analytical model. The present work introduces an important tool to the design and selection of WDE resistant materials.

Effects of a Labyrinth Weir with Outlet Ramps on Downstream Steep-Stepped Chute Sidewall Height Requirements

Labyrinth weirs are commonly used to increase spillway discharge capacity. Stepped chutes represent a common spillway element used to help dissipate kinetic energy, thus reducing the size requirement and often the cost of the downstream energy dissipation basin. When combined, the complex, highly turbulent, aerated flow patterns generated by the labyrinth weir create different aeration inception point behaviors relative to traditional stepped chute applications (e.g., linear weir upstream). To reduce the risk of erosion and other damage near the spillway, stepped chute sidewalls are typically designed with sufficient height to contain the majority, if not all, of the bulked air-water spillway flow and surface waves. This study evaluated some of the hydraulic impacts of coupling a labyrinth weir with a relatively steep-stepped chute (08H:1V) at the laboratory scale in an effort to provide some useful guidance related to the sizing stepped chute wall heights. Test results showed that required chute wall heights for bulked flow containments were higher at the chute entrance than the traditional stepped chute (i.e., no labyrinth weir) design predictions. Placing ramped floors in the labyrinth weir downstream cycles facilitates the transition from the labyrinth outlet cycles to the steep chute and, in some cases, reduced maximum chute water levels. To better understand this phenomenon and provide guidance toward the use of ramped floors to reduce chute wall height requirements, the hydraulic behavior of various ramped floor configurations was systematically evaluated. The results for the geometries tested ranged from no effect to a 15% reduction in maximum chute flow depth.

Cavitation erosion damage of self-fluxing NiCrSiB hardfacings deposited by oxy-acetylene powder welding

This paper comparatively investigates the cavitation erosion damage of two self-fluxing NiCrSiB hardfacings deposited via the oxy-acetylene powder welding method. Examinations were conducted according to the procedure given by ASTM G32 standard. In order to research cavitation erosion (CE), the vibratory apparatus was employed. The cavitation damaged surfaces were inspected using a scanning electron microscope, optical microscope and surface profilometer. The hardness of the A-NiCrSiB hardfacing equals 908HV while that of C-NiCrSiB amounts to 399HV. The research showed that the CE resistance of C-NiCrSiB is higher than that of A-NiCrSiB. The results demonstrate that in the case of multiphase materials, like the NiCrSiB hardfacings, hardness cannot be the key factor for cavitation erosion damage estimation whereas it is strongly subjected to material microstructure. In order to qualitatively recognise the cavitation erosion damage of the NiCrSiB self-fluxing hardfacings at a given exposure time, the following factors should be respected: physical and mechanical properties, material microstructure and also material loss and eroded surface morphology, both stated at specific testing time. The general idea for the cavitation erosion damage estimation of the NiCrSiB oxy-acetylene welds was presented.

Adverse local tissue reaction after ceramic-on-ceramic total hip arthroplasty

Outside of cobalt-chromium alloy articulations, the development of adverse local tissue reaction (ALTR) after total hip arthroplasty (THA) is uncommon but remains a significant complication [1]. ALTR is used to describe a granulomatous or destructive cystic lesion that develops around a THA [1,2]. The patient often describes the first sign of the development of ALTR and pseudotumor formation as discomfort and pain. ALTR causes soft tissue mass, osteolysis, bone erosion, and significant damage to periarticular soft tissues, leading to total joint failure and instability [1]. In THA, ALTR may develop around metal-onpolyethylene implants due to taper corrosion and around metal-on-metal (MoM) bearing surfaces [3-6].

Vulnerability Analysis of Episodic Beach Erosion by Applying Storm Wave Scenarios to a Shoreline Response Model

Recently, because of the influence of climate change on sea level change, there has been growing concern regarding the erosion of beaches, which play a role in reducing the damage caused by coastal disasters. However, despite these concerns, a comprehensive understanding of the morphodynamic relationship between hazard factors and beach erosion is still lacking. Therefore, in this study, a vulnerability analysis of beach erosion was conducted by applying the shoreline response model (SLRM) of bulk model type, which identifies the physical characteristics of relevant coefficients based on the suspended sediment movement processes. To characterize wave energy incidence, storm wave scenario modeling and extreme wave analysis were conducted using wave data of 40 years on the east coast of Korea provided by the National Oceanic and Atmospheric Administration. A dimensionless mathematical function representing the storm wave scenario was proposed as a function of the peak wave height. In addition, to examine whether the beach vulnerability curve (BVC) obtained from the SLRM is valid, it was compared with the long-term shoreline observation data conducted at Maengbang Beach. For the past 9 years, sand sampling and shoreline observations were performed at Maengbang Beach about 5 times a year. However, since observations were performed in time intervals of several months, the direct comparison with model results was impossible, so a comparative analysis through statistical analysis of shoreline variability was performed. The variability of the shoreline for each reference point followed a normal distribution with a standard deviation of approximately 7.1 m. As a result of comparing the BVC results obtained from these statistical characteristics with those obtained from the model, significant similarity was shown in the high wave condition. Finally, the model was performed on two factors (mean wave height and peak wave height) which appear in SWSF and three factors (wave energy at breaking point, beach response factor and beach recovery factor) which appear in SLRM, and by analyzing the results, an approximate formula for the BVC is derived. This novel BVC approximation equation provides an intuitive understanding of the factors that affect beach vulnerability as well as their importance, and estimates the beach buffer section required to prevent coastal facilities from being damaged by erosion during a specific period. The results of this study can help limit reckless coastal development and mitigate erosion damage.

Investigating the erosive wear caused by dry-ice blasting in paint stripping process

Dry-ice blasting (DIB) has been widely used in the industry for several applications. However, its erosive effect on surfaces has not been studied deeply. This work aims to study the efficiency of DIB for stripping organic coatings (paints) on steel surfaces and its corresponding erosive damage as generated by different jet angles. In addition, the surface cooling during DIB was analyzed to get a deeper understanding of its influence on erosion wear mechanisms. The results have shown that the stripping efficiency increased with the increase of jet impact angle exhibiting minor evidence of surface damage in form of micro craters. In addition, it was observed that surface cooling could be reduced by increasing the initial temperature of the sample and reducing impact angles (i.e., 30°). Finally, it was found that the erosive wear mechanism of DIB is controlled by the ductile–brittle transition of the surface by undercooling caused by DIB.

Experimental study on performance optimization for full-scale swirl separator of air-water in PWR UTSG

The separation of liquid water from the steam-water mixture is one of the key processes in U-tube steam generators, which is critical to assure the turbine safety by minimizing the water erosion damage. To develop a highly successful separator under actual operating conditions, air-water tests are carried out to study the effect of different separation heights above swirl vanes on the separation performance. The tests are based on a full-scale separator with the air superficial velocity ranging from 10 m/s to 19 m/s and the water superficial velocity including 0.127 m/s and 0.151 m/s. The moisture carryover in this work is in the range of 0.3%–0.6%, which increases with the air superficial velocity increasing. While the air velocity is under 13.8 m/s, the moisture carryover almost changes little with the increase of separation heights. Nevertheless, the moisture carryover decreases significantly with the increase of separation heights for the air velocity above 15.5 m/s. The pressure drop increases approximately linearly with the increase of the air superficial velocity, and almost remains unchanged for different separation heights. To obtain better separation performance in a wide range of operation conditions, the maximum separation height is recommended.

Erosive arthritis in systemic lupus erythematosus: not only Rhupus.

Systemic lupus erythematosus (SLE)-related arthritis has been traditionally defined as non-erosive and is therefore considered a minor manifestation requiring a mild treatment. However, the concept of non-erosive arthritis in SLE has been challenged with the advent of sensitive imaging techniques, such as high-resolution ultrasound with power Doppler or magnetic resonance. The application of these new imaging tools has demonstrated that up to 40% of SLE patients with joint involvement can develop erosive damage. Thus, this more aggressive phenotype can be identified not only in patients overlapping with rheumatoid arthritis (RA). This issue has been considered for the first time in the classification criteria proposed by Systemic Lupus International Collaborating Clinics in 2012, in which the old definition of "non-erosive arthritis" was replaced with either synovitis or tenderness in two or more joints with morning stiffness, suggesting the possible presence of an erosive phenotype. Accordingly, the 2019 EULAR/ACR's SLE recommendations advise treatment with immunosuppressant or biological drugs for patients with RA-like moderate arthritis. As a result, several studies have investigated the presence of biomarkers associated with SLE erosive damage. A relevant role seems to be played by the autoantibodies directed against post-translational modified proteins: above all, a significant association has been observed with antibodies directed against citrullinated and carbamylated proteins. Conversely, the rheumatoid factor was not associated with this more aggressive SLE-related arthritis. Nonetheless, some pro-inflammatory factors have been associated with erosive damage in SLE patients. These results suggest new pathogenic mechanisms underlining erosive arthritis, only partially shared with RA. Hence, in the present narrative review, we summarized available data about erosive arthritis in SLE patients, in the light of its impact on therapeutic decisions.

Management of erosive tooth wear

Erosive tooth wear is an oral health problem that worries clinicians and researchers worldwide. The aim of this study is to describe, through a literature review, the erosive tooth wear management. This problem is a challenge for dental surgeons, especially when it reaches more advanced stages, which can cause loss of dental and aesthetic function, as well as generate hypersensitivity to the patient. To prevent the progression of this problem focusing into preventive measures, such as guidelines for feeding and oral hygiene, the dental surgeon must perform early diagnosis to minimize erosive tooth wear damage.

Analysis and Prediction of Sulfate Erosion Damage of Concrete in Service Tunnel Based on ARIMA Model.

Sulfate erosion is a major cause of concrete durability deteriorations, especially for the service tunnels that suffer sulfate erosion for a long time. Accurately predicting the concrete damage failure under sulfate erosion has been a challenging problem in the evaluation and maintenance of concrete structures. Here we design the dry–wet cycle test of service tunnel concrete under sulfate erosion and analyze the Elastic relative dynamic modulus (Erd) and mass under 35 times cycle periods. Then we develop an autoregressive integrated moving average (ARIMA) prediction model linking damage failure to Erd and mass. The results show that the deterioration of concrete first increased and then decreased with an extension of the dry–wet cycle period. Moreover, based on a finite set of training data, the proposed prediction approach shows high accuracy for the changes of concrete damage failure parameters in or out of the training dataset. The ARIMA method is proven to be feasible and efficient for predicting the concrete damage failure of service tunnels under sulfate erosion for a long time.

Erosion damage and expansion evolution of interfacial transition zone in concrete under dry-wet cycles and sulfate erosion

Interfacial transition zone (ITZ) is of paramount importance to the durability of concrete. However, the evolution of damage characteristics and mechanical properties of ITZ under dry-wet cycles and sulfate erosion were not fully investigated in the literature. Therefore, this paper presents the expansive model of ITZ based on cylindrical cavity expansion theory, following by calculation of mechanical properties evolution of ITZ under sulfate erosion. The expansion ratio, Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD) were utilized to analyze the internal erosion and expansion characteristics of concrete with the water-cement ratio (w/c) of 0.3, 0.4 and 0.5. The results indicate that the expansion ratio of concrete increases with the erosion age and w/c. The new diffraction peaks appear in the XRD pattern after sulfate erosion. As compared with Poisson's ratio (γ) and internal friction angle (φ), cohesive force (C) has the largest influence on the internal stress and plastic zone width. The final internal stress and plastic zone width are affected by w/c, and the damage degree of concrete with 0.4 w/c is the minimum. This study provides new insights into damage mechanism of concrete and ITZ under dry-wet cycles and sulfate erosion, the results of which provide new perspectives for improving the durability of concrete.

Study on the erosion wear in pipe fittings

In the pipeline system for slurry, local erosion wear failure has become the main damage mechanism of pipe in the fracturing operations of oil-gas engineering. Computational Fluid Dynamics simulation is performed to determine the evolutionary process of erosion wear in tubing connector, which is the resistance of pipeline system, and a new way to predict the pipeline longevity is provided. Based on the Euler equation, solid particle concentration in the slurry and interphase momentum exchange are included in the liquid flow equations due to the influence of dense particle on slurry (slurry is a two-phase flow), and the particle trajectory were calculated in the Lagrange frame by analyzing the forces from the interaction of liquid and particle and particles impact. With the erosion damage model, the erosion rate/depth in the connector was calculated to reconstruct the mesh model of shoulder with 5 tori. Torus 1 is closest to axis while torus 5 is on the outmost wall of the connector. During the erosion event, greatest erosion and hence surface deformation occurs on tori 1 and 2, and this affects the surrounding flow and particle movement. After 10 hours of erosion, there was a dramatic drop in the maximum erosion rate, which illustrated a conservative prediction for pipeline service life if the initial erosion rate was used. An erosion experimental setup was also performed to identify the weight loss and erosion characteristic of the inner surface with erosion time of 55 hours. It was observed that the erosion simulations provided relative errors within 18% for erosion length and weight loss compared to the experimental values and a closed form equation for the erosion rate was proposed to predict the erosion life of tubing connector

An equivalent method of jet impact loading from collapsing near-wall acoustic bubbles: A preliminary study

Cavitation damage is a micro, high-speed, multi-phase complex phenomenon caused by the near-wall bubble group collapse. The current numerical simulation method of cavitation mainly focuses on the collapse impact of a single cavitation bubble. The large-scale simulation of the cavitation bubble group collapse is difficult to perform and has not been studied, to the best of our knowledge. In this study, the equivalent model of impact loading of acoustic bubble collapse micro-jets is proposed to study the cavitation erosion damage of materials. Based on the theory of the micro-jet and the water hammer effect of the liquid–solid impact, an equivalent model of impact loading of a single acoustic bubble collapse micro-jet is established under the principle of deformation equivalence. Since the acoustic bubbles can be considered uniformly distributed in a small enough area, an equivalent model of impact loading of multiple acoustic bubble collapse micro-jets in a micro-segment can be derived based on the equivalent results of impact loading of a single acoustic bubble collapse micro-jet. In fact, the equivalent methods of cavitation damage loading for single and multiple near-wall acoustic bubble collapse micro-jets are formed. The verification results show the law of cavitation deformation of concrete using equivalent loading is consistent with that of a micro-jet simulation, and the average relative errors and the mean square errors are insignificant. The equivalent method of impact loading proposed in this paper has high accuracy and can greatly improve the calculation efficiency, which provides technical support for numerical simulation of concrete cavitation.

Effects of Plate Edge Thickness on Droplet Generation Caused by Water Film Breakup at the Plate Edge

Abstract Droplets generated at trailing edges of low-pressure steam turbines strike the leading edge of moving blades, resulting in severe damage by erosion. Although the trailing edges of stationary blades employed in the steam turbine industry are often sharpened to produce fine droplets, this process requires further investigation. In this study, water film flows on a plate and breakup patterns are observed and measured to investigate the breakup behavior and the effect of the plate edge thickness. First, to determine the general characteristics of droplet formation of water film flows, the droplet diameter frequency distributions, which significantly affect erosion damage, are measured for several flow conditions. Profiles of frequency distribution of the droplet diameters exhibit on approximately linear in a semilog graph. Water lumps formed on the plate edge are expressed as a spanwise wavelength and initiate the primary breakup of the water film, while fine droplets whose diameters are similar to the critical diameter are generated and are assumed to contribute significantly to erosion damage. The effect of edge thickness on droplet diameter frequency distribution and the spanwise wavelength are observed. The plate edge thickness does not affect the frequency distributions of the droplet diameter. However, it does affect the spanwise wavelength, which is related to the intermittent discharge of water from the edge. The spanwise wavelength and discharged water period become longer when the plate edge thickness increases. Based on an experiment involving the highest airflow velocity, the discharged water frequency is similar to that generated by a general turbine rotation speed.