Impingement Test Research Articles

Flow Velocity and Sand Loading Effect on Erosion–Corrosion during Liquid-Solid Impingement on Mild Steel

The presence of CO2, sand, and water in oil and gas reservoirs causes erosion–corrosion leading to material degradation in pipelines and fluid handling equipment that results in increasing maintenance and repair costs and a decrease in production. While the weight loss caused by erosion–corrosion is known to depend on flow velocity, angle of impact, sand loading and size and target material properties, field operators often limit the flow rate based on a critical corrosion velocity to protect the equipment. This study investigates the effects of sand loading and flow velocity on weight loss associated with erosion–corrosion in a mild steel sample using a submerged impingement jet. The weight loss by erosion, corrosion and their interaction for a flow velocity range of 10 m/s to 20 m/s and sand loading range of 300 mg/L to 600 mg/L, in a seawater environment, are presented. The results showed that the weight loss by pure erosion and erosion–corrosion interaction increases linearly with jet velocity and sand loading, and that erosion is dominant in all cases except at low velocity and sand loading. The scanning electron microscope (SEM) images after impingement tests were analyzed. In addition, correlations for the velocity and sand loading were derived using the design of experiment method (DOE).

Comprehensive supervised heavy training program versus home training regimen in patients with subacromial impingement syndrome: a randomized trial

BackgroundThere is no consensus on the best training regimen for subacromial impingement syndrome (SIS). Several have been suggested, but never tested.The purpose of the study is to compare a comprehensive supervised training regimen (STR) based on latest evidence including heavy slow resistance training with a validated home-based regimen (HTR). We hypothesized that the STR would be superior to the HTR.MethodsRandomised control trial with blinded assessor. 126 consecutive patients with SIS were recruited and equally randomised to 12 weeks of either supervised training regimen (STR), or home-based training regimen (HTR). Primary outcomes were Constant Score (CS) and Shoulder Rating Questionnaire (SRQ) from baseline and 6 months after completed training. Results were analyzed according to intention-to treat principles. The study was retrospectively registered in ClinicalTrials.gov. Date of registration: 07/06/2021. Identification number: NCT04915430.ResultsCS improved by 22.7 points for the STR group and by 23,7 points for the HTR (p = 0.0001). The SRQ improved by 17.7 and 18.1 points for the STR and the HTR groups respectively (p = 0.0001). The inter-group changes were non-significant. All secondary outcomes (passive and active range of motion, pain on impingement test, and resisted muscle tests) improved in both groups, without significant inter-group difference.ConclusionWe found no significant difference between a comprehensive supervised training regimen including heavy training principles, and a home-based training program in patients with SIS.

Modelling the particle trajectory and melting behaviour of non-spherical ice crystal particles

Existing ice crystal icing codes commonly neglect non-spherical particle rotation behaviour. This leads to uncertainties in modelling ice crystal icing as ice crystals are typically non-spherical. This paper develops a two-dimensional framework to model the particle trajectory and melting behaviour of rotating non-spherical ice crystal particles. Non-spherical particle translational and rotational motions are resolved using a framework of unit complex numbers. The effect of rotation on particle heat and mass transfer is implemented using a sub-model dependent on both rotational and translational particle Reynolds numbers. A test case of flow through a swan neck duct is presented. The model is validated through comparison to the discrete phase model in ANSYS Fluent and experimental water droplet impingement test data. Comparison of the developed framework with other simplified particle tracking methods (without modelling the non-spherical particle rotation) is first conducted. These results show large differences in the trajectory, velocity and melt ratio of individual particles and in overall particle impingement behaviours, especially for high aspect ratio particles. Particle rotation can indirectly affect single particle’s melting behaviour through its effect on particle trajectory and velocity. Both aspect ratio and porosity are seen to enhance particle melting behaviour and affect particle impingement behaviour. The numerical uncertainties in the DNS-based correlations of the particle forces and torques employed are also discussed, as well as the performance of the developed framework for the case of a flow past a test article.

Interpretation of ischiofemoral impingement via a clinical test using hip triaxial dynamic magnetic resonance imaging.

The present study aimed to use magnetic resonance (MR) to explore the dynamic changes of the ischiofemoral space (IFS) under the triaxial motion of the hip joint and verify the clinical test mechanism for ischiofemoral impingement (IFI). A prospective design was used to screen 37 patients with clinically confirmed IFI, which included a total of 67 lateral hips, and 39 healthy controls with a total of 69 lateral hips. A dynamic MR examination was performed in positions designed by a simulated IFI test (adduction, adduction with 30° external rotation, 30° internal rotation, supine with 30° flexion, and prone with 30° backward extension). The IFS (mm) and quadratus femoris space (QFS, mm) were measured in different positions. All the data were evaluated independently by three musculoskeletal radiologists. The differences between the two groups were compared using the two-tailed t-test. The IFS and QFS in the case group were smaller than those in the control group. The IFS and QFS were significantly reduced in the prone with backward extension and adduction with external rotation positions of the hip. The correlation coefficients of the IFI test and long-stride walking (LSW) test were -0.621 and -0.715 for IFS and -0.653 and -0.696 for QFS, respectively. In this study, the mechanism of the IFI-specific clinical examination (IFI and LSW tests) was verified by triaxial dynamic MR imaging of the hip joint, which provided a dynamic imaging basis for the clinical application of the IFI-specific impingement test. The IFI impingement test can be used as a specific clinical test for IFI screening.

OSTEOTOMY AT THE BASE OF FEMORAL NECK AND OSTEOPLASTY FOR THE TREAMENT OF SCFE.

To compare the clinical outcomes between patients with moderate and severe slipped capital femoral epiphysis (SCFE) treated with osteotomy at the base of neck and osteoplasty and with healthy individuals. Comparative cohort with 12 patients (14 hips) with moderate and severe SCFE who underwent osteotomy at the base of neck and osteoplasty between 2007 and 2014. The mean age at surgery was 13.3 ± 2.5 years and the mean follow-up was 3.8 ± 2.2 years. We assessed the level of hip pain by the visual analog scale (VAS) and anterior impingement test (AIT); the level of function using the Harris Hip Score (HHS) and 12-Item Short Form Health Survey (SF-12), the range of motion (ROM) by goniometry and Drehmann sign, and the hip muscular strength by isokinetic and Trendelenburg sign. The level of pain was slightly higher in the SCFE cohort compared with healthy hips (VAS, 0.8 ± 1.4 vs 0 ± 0, 0.007; AIT, 14% vs 0%, p = 0.06; respectively). No differences were observed between the SCFE and control cohort for the functional scores (HHS, 94 ± 7 vs 100 ± 1, p = 0.135); except for ROM, with increased internal rotation (37.3º ± 9.4º vs 28.7º ± 8.2º, p < 0.001), and strength, with decreased abduction torque (75.5 ± 36.9 Nm/Kg vs 88.5 ± 27.6 Nm/Kg, p = 0.045) in the SCFE cohort. The osteotomy at the base of neck and the osteoplasty restored the hip motion and muscle strength, except for the abductor strength, to near normal levels, representing a viable option for the treatment of moderate and severe SCFE. Level of Evidence III, Ambidirectional Cohort Study.

Experiences of living with developmental dysplasia of the hip in adults not eligible for surgical treatment: a qualitative study

ObjectivesAdults with developmental dysplasia of the hip face barriers in their everyday lives due to pain and physical limitations. In Denmark, some patients may not be eligible for hip-preserving surgery...

Hip Profile in World Elite Junior Badminton Players: Impingement and Range of Motion Data from the World Junior Badminton Championship 2018

AbstractBadminton is played with repetitive high loading to the hip with lunging and jumps. In sports like soccer there is a high prevalence of femoroacetabular impingement syndrome in youth populations which may predispose them to osteoarthritis (OA). Internal rotation deficit in the hip of football players is a predictor of hip and groin pain and differences in the range of motion (ROM) of the hip between sex and different ethnicities exist. Early hip replacements in former elite badminton players due to OA seem to be a problem. There are no published values for ROM and impingement of the hip in badminton. The purpose is to report ROM and impingement of the hip in elite junior badminton players and to report any differences between sex and ethnicities. Players at the World Junior Championship 2018 were examined for hip flexion, rotation, and impingement test. Injury history was obtained from a questionnaire. Two hundred and eighty-four players of 433 aged 16 to 18 years were examined. One hundred and forty-three players answered the questionnaire. Females demonstrated greater hip ROM than males. In the dominant side hip flexion was (137.7 degrees [ ± 9.1] vs. 132.2 degrees [ ± 11.1], p &lt; 0.001), internal rotation range of motion or IROM (60.0 degrees [ ± 10.9] vs. 49 degrees [ ± 11.1], p &lt; 0.001) and external rotation range of motion or EROM (57.9 degrees [ ± 9.9] vs. 54.7 degrees [ ± 8.9], 0.004). Hip flexion was higher in Asian players compared with non-Asian players (139.1 degrees [ ± 8.4] vs. 130.3 degrees [ ± 10.7], p &lt; 0.001). One hundred (35%) players had at least one positive impingement test. A possible relationship between a positive FADIR and a decrease in hip flexion was found in the dominant hip, OR 1.06 (1.02–1.11) p = 0.005. A total of 104 previous injuries lasting over 30 days were reported with five hip-related injuries. No correlation between injury and examinations was found. Females and Asians demonstrated higher ROM in the hip than males and non-Asians. Impingement of the hip is frequent and may be related to low hip flexion.

Relationship between shoulder ultrasound findings and disease activity in patients with rheumatoid arthritis: A pilot study.

Objectives The aim of this study was to investigate whether shoulder ultrasound (US) findings were associated with disease activity and pain level in rheumatoid arthritis (RA) patients.Patients and methods Between April 2019 and November 2019, a total of 60 shoulders of 30 female patients with RA (mean age: 53.8±12.0 years; range, 30 to 65 years) were included. The patients were questioned about shoulder pain and their Disease Activity Score-28 (DAS28) was estimated. After clinical examination with shoulder impingement tests, both shoulders were evaluated by US.Results Of 60 shoulders examined by shoulder US, the most common shoulder pathology was supraspinatus tendinopathy (n=33, 55%). The prevalence of subdeltoid bursitis on US was significantly higher in the group with moderate disease activity, compared to the group with low disease activity (p<0.05). There were no significant differences in the physical examination findings of patients with low and moderate disease activity. In terms of US findings, subscapularis tendinopathy, glenohumeral joint and acromioclavicular joint degeneration, and subacromial bursitis were more common in shoulders with a history of pain, compared to non-painful shoulders.Conclusion Shoulder US may be useful for demonstrating shoulder involvement in patients with RA, independent of the presence of shoulder pain.

Определение патогномоничных признакокомплексов при клиническом и МРТ-обследовании внутрисуставных мягкотканных повреждений при посттравматическом коксартрозе

Актуальность. В настоящее время около 60 % внутрисуставных повреждений непосредственно тазобедренного сустава (ТС) диагностируются неправильно из-за отсутствия изменений на рентгенограммах на ранних (дорентгенологических) стадиях. Считается, что диагностика травм и заболеваний, ведущая к нарушению функции ТС, относительно проста. Однако с этим можно согласиться лишь в случаях выраженных морфологических изменений субхондральной кости, когда процесс разрушения суставного хряща достиг значительной степени и изменения в костной ткани компенсируют нагрузку суставных поверхностей. Цель. Определение патогномоничных признакокомплексов (сочетание клинических и МРТ-признаков), характеризующих внутрисуставные мягкотканные повреждения при посттравматическом коксартрозе (ПТ КА). Материалы и методы. Обследованы 30 пациентов с ПТ остеоартрозом ТС I–II стадии. Целью обследования было исследовать информативность и специфичность клинических и лучевых методов исследований по сравнению с артроскопией в диагностике внутрисуставных мягкотканных повреждений у больных на ранних стадиях ПТ КА. Для оценки распространенности внутрисуставных поражений мягко­тканных элементов КС у больных с нарушениями функции ТС (больных с начальными стадиями ПТ КА) и их сочетаний был проведен частотный анализ. Результаты. Определены патогномоничные признакокомплексы (сочетание клинических и МРТ-признаков), характеризующие внутрисуставные повреждения мягкотканных элементов ТС при начальных стадиях ПТ КА. К ним при pincer-ФАК относятся сочетания признаков: FABER (Patrick) + тест Стинчфилда + дегенеративные изменения (разрыв) суставной губы + костные изменения в шейке бедренной кости, импинджмент-тест + FABER (Patrick) + тест Стинчфилда + дегенеративные изменения (разрыв) суставной губы. Определены патогномоничные признакокомплексы (сочетание клинических и МРТ-признаков), характеризующие внутрисуставные поражения мягкотканных элементов ТС при начальных стадиях ПТ КА. К ним при cam-ФАК относятся сочетания признаков: импинджмент-тест + тест Стинчфилда (подъем прям. ноги с преод. сопр.) + дегенеративные изменения (разрыв) суставной губы + угол альфа больше 55°, импинджмент-тест + FABER (Patrick) + тест Стинчфилда + дегенеративные изменения (разрыв) суставной губы, импинджмент-тест + Log roll-тест + дегенеративные изменения (разрыв) суставной губы + угол альфа больше 55°. При определении изолированного ПТ повреждения суставной губы и свободных суставных тел полости ТС при ПТ КА наиболее информативным является сочетание 2 признаков (клинический + МРТ): для изолированного повреждения губы — тест Стинчфилда + МРТ-признак повреждения суставной губы, для наличия свободных суставных тел — тест Стинчфилда + МРТ-признак наличия свободных суставных тел. Признакокомплексы встречались в 100 % случаев. Выводы. Определение вышеупомянутых патогномоничных признакокомплексов будет способствовать улучшению качества диагностики внутрисуставных поражений ТС, их раннему выявлению с последующим оперативным вмешательством, уменьшению прогрессирования остеоартроза ТС.

Fabrication and durability characterization of superhydrophobic and lubricant-infused surfaces

HypothesisPractical applications of non-wetting surfaces require good mechanical durability in the wet environments for which they are intended to be used. Durability of non-wetting surfaces is influenced by the surface features, interaction with the functionalization agent, and the lubricant properties that can be tuned independently to identify optimal combination. ExperimentsIn this study, superhydrophobic and lubricant-infused surfaces are fabricated on copper tubes using chemical etching and electrodeposition texturing techniques, six different functionalizing agents, and five different infused lubricants. Through 180 fabrication combinations and 102 durability tests, each parameter is systematically studied for contributions to initial non-wetting behavior and its durability in heated, wet environment, under high-energy water jet impingement, and under accelerated flow conditions. FindingsAmong the adsorbing and curing functionalization agents investigated, n-Hexadecyl mercaptan that belongs to the sulfhydryl group and Sylgard-184, respectively, showed high durability in heated water immersion and under jet impingement tests. For lubricant-infused surfaces, lubricants with high surface tension demonstrated high durability in heated water immersion test, whereas durability in hydrodynamic conditions is closely correlated to lubricant viscosity. Results showed that a lubricant-infused surface will maintain its non-wetting properties in dropwise condensation conditions for approximately 1.5 years.

Effect of impact angle and impact velocity on the slurry erosion behavior of high density polyethylene (HDPE)

High density polyethylene is widely used in many applications which deal with slurry because of its high erosion resistance characteristics. Slurry erosion is a type of erosive wear which takes place when a stream of liquid hits a solid body and results erosion in this body surface. Slurry erosion is affected by some parameters as material hardness, impact velocity, impact angle, slurry content, ambient temperature, particle hardness, particle size and particle shape. The changing of these parameters individually will result in useful analysis for the changing in slurry erosion rate with respect to the changed parameter. This experimental work aims to investigate the slurry erosion behavior of high density polyethylene under the effect of different impact velocities. A slurry impingement test rig will be used to make the wear test and wear rate of HDPE is investigated as a function of impact velocity and impact angle. Results showed that the maximum wear rate is at the lowest impact angle and maximum impact velocity. Weight loss is the indication of wear rate of the HDPE specimens after experiment and wear rate is defined as weight loss during the test time in [mg/h] unit

Experimental and Numerical Heat Transfer Investigation of Impingement Jet Nozzle Position in Concave Double-Wall Cooling Structures

In this paper, experimental and numerical study has been carried out to investigate impingement cooling with a row of five circular jets, varied between target positions on a realistic leading edge region of gas turbine blade geometry. Experimental data is collected from a transient thermochromic liquid crystal measurement technique at the target surface. Numerical study was conducted with the geometry using commercial computational fluid dynamics software to analyze the fluid flow. The unique aims of the study are to observe the effects of variation in jet location, and those specific to realistic target and nozzle geometries. Distributions of local and average Nusselt number show that a location targeting the concave surface at 90° demonstrates an overall higher heat transfer coefficient, especially in the stagnation region, and toward the airfoil sides, with significantly fewer swirls. The experiment was performed with the following parameters: distance from nozzle to target of 1.7 to 2.1 jet diameters, pitch between jets of 4.4 jet diameters, and concave target diameter of 8.0 jet diameters. The jet Reynolds number range during this test was 20,000 − 40,000. A standard flat target plate impingement test is also experimentally conducted and compared against existing literature for method validation.

"Complications in Blepharoplasty and How to Resolve Them"

Any type of eyelid correction or postoperative blepharoplasty complication should be well managed and studied before attempting its correction, as it could lead to a worsening of the original alteration. Although postoperative scars in a blepharoplasty are relatively rare, they can generally be improved by massage and late with the application of topical corticosteroids, with the understanding that their best use is during the first twelve months. An early intervention should be avoided as this can worsen the result and rarely improve the final result, when there is a healing problem, remembering that stress is a determining factor in the final result. The laxity of the canthus tendons should always be evaluated either by directly pulling the eyelid down, with an eyelid glide test, the impingement test, and a poor eyelid position prior to surgery should always be documented. In these cases, the surgeon who operates blepharoplasty must have a perfect knowledge of the management of the canthal tendons and have within his surgical resources the realization of the canthal application or the repositioning of the palpebral canthal tendon.

Femoroacetabular Impingement of the Hip Joint – Literature Review

Introduction: In patients with painful hip joint, femoroacetabular impingement is a relatively frequently diagnosed condition. Study aim: The aim of the study was to present the anatomy, biomechanics and pathomechanism of femoroacetabular impingement, surgical diagnostics and treatment, as well as physiotherapeutic procedures, and to provide answers to the following questions: 1. What are the causes of femoroacetabular impingement development and what is its most common form? 2. What are the clinical and imaging diagnosis of femoroacetabular impingement based on? 3. What are the goals of physiotherapeutic treatment in the treatment of patients with postoperative femoroacetabular impingement? Material and method: Current professional literature was analysed based on a review of Internet databases, including Pubmed and Google Scholar. Results: From the abovementioned Internet databases, 30 items from the current profession-al literature on the analysed variables were identified. Conclusions: The reasons for the development of femoroacetabular impingement are com-plex, including developmental disorders of the hip joint or its chronic overload. Its most common form is mixed type. The basic imaging test used is anterior-posterior X-ray, while clinical assessment is based on anterior-posterior impingement test. Physiotherapy should be individually tailored and focused on improving range of motion and muscle strength of the hip joint.

Posterior Extra-articular Ischiofemoral Impingement Can Be Caused by the Lesser and Greater Trochanter in Patients With Increased Femoral Version: Dynamic 3D CT-Based Hip Impingement Simulation of a Modified FABER Test.

Background:Posterior extra-articular hip impingement has been described for valgus hips with increased femoral version (FV). These patients can present clinically with lack of external rotation (ER) and extension and with a positive posterior impingement test. But we do not know the effect of the combination of deformities, and the impingement location in early flexion is unknown.Purpose:To evaluate patient-specific 3-dimensional computed tomography (3D CT) scans of hips with increased FV and control hips for differences in range of motion, location and prevalence of osseous posterior intra- and extra-articular hip impingement.Study Design:Case series; Level of evidence, 4.Methods:Osseous 3D models based on segmentation of 3D CT scans were analyzed for 52 hips (38 symptomatic patients) with positive posterior impingement test and increased FV (>35°). There were 26 hips with an increased McKibbin instability index >70 (unstable hips). Patients were mainly female (96%), with an age range of 18 to 45 years. Of them, 21 hips had isolated increased FV (>35°); 22 hips had increased FV and increased acetabular version (AV; >25°); and 9 valgus hips (caput-collum-diaphyseal angle >139°) had increased FV and increased AV. The control group consisted of 20 hips with normal FV, normal AV, and no valgus (caput-collum-diaphyseal angle <139°). Validated 3D CT–based collision detection software for impingement simulation was used to calculate impingement-free range of motion and location of hip impingement. Surgical treatment was performed after the 3D CT–based impingement simulation in 27 hips (52%).Results:Hips with increased FV had significantly (P < .001) decreased extension and ER at 90° of flexion as compared with the control group. Posterior impingement was extra-articular (92%) in hips with increased FV. Valgus hips with increased FV and AV had combined intra- and extra-articular impingement. Posterior hip impingement occurred between the ischium and the lesser trochanter at 20° of extension and 20° of ER. Impingement was located between the ischium and the greater trochanter or intertrochanteric area at 20° of flexion and 40° of ER, with a modification of the flexion-abduction-ER (FABER) test.Conclusion:Posterior extra-articular ischiofemoral hip impingement can be caused by the lesser and greater trochanter or the intertrochanteric region. We recommend performing the modified FABER test during clinical examination in addition to the posterior impingement test for female patients with high FV. In addition, 3D CT can help for surgical planning, such as femoral derotation osteotomy and/or hip arthroscopy or resection of the lesser trochanter.

Erosion-Corrosion Mechanisms of Engineering Steels in Different NaCl Concentrations

This study utilises a recently developed, enhanced approach to assess detailed aspects of the corrosive wear behaviour of different steel grades in aqueous slurries containing three NaCl concentrations (0.05%NaCl, 3.5%NaCl and 10%NaCl). Erosion-corrosion testing was conducted using a slurry impingement test rig and damage was quantified using volume loss, potentiodynamic polarisation scans and surface topography. Single- and segmented specimens were adopted to yield the contribution of the degradation mechanisms in the two hydrodynamic zones (directly impinged and surrounding area). The overall material losses from the two zones of the stainless steels were observed to increase with increasing salinity. However, the overall material loss for the low-alloy steel was found to increase from 0.05%NaCl to 3.5%NaCl, before reducing when the salinity was further increased to 10%NaCl. Changes in salinity were observed to have the most effect on the corrosion-enhanced mechanical damage mechanism. The in-house developed technique demonstrated good linkage between single samples and the outer area damage region. However, it also showed that the use of single samples can be less successful when assessing highly turbulent (directly impinged) damage regions.

Correlation between depassivation and repassivation processes determined by single particle impingement: Its crucial role in the phenomenon of critical flow velocity for erosion-corrosion

The correlation between depassivation and repassivation processes, which is significant in erosion-corrosion, was quantitatively investigated by single particle impingement tests at various flow velocities and impact angles. The results show that both repassivation and depassivation processes are associated with the kinetic energy of solid particle, and demonstrate that the repassivation is retarded by depassivation. This phenomenon probably results from the depassivation-induced microstructure evolution. On this basis, the dependence of critical flow velocity (CFV) for erosion-corrosion on the solid particle concentration and diameter is further theoretically predicted and experimentally verified. Accordingly, the crucial role of depassivation-repassivation in CFV phenomenon is further highlighted.

Erosion testing and modeling of several non-metallic materials

Polymer composite materials are finding increased application within industry as traditional metal components are much more costly. Many of these materials are exposed to severe solid particle erosion by sand particles, such as in oil and gas and process industries. Although, many studies have been performed on the erosion of various metals and erosion models exist to predict their erosion behavior, comprehensive studies and models on the erosion of non-metallic materials are not available. This paper aims to examine solid particle erosion of several non-metallic materials and develop and extend erosion models for these non-metallic materials.Dry direct impingement testing was conducted at three particle velocities of 12, 24, and 36 m/s and four impact angles of 15, 30, 60, and 90°. Semi-rounded particles of size 150 μm were used in these experiments. Material types included two thermoplastics, one elastomer, and one fiber-reinforced. Experimental results indicated that these materials yield erosion wear weight loss that was comparable or lower in magnitude to stainless steel.A few existing models for metallic and non-metallic materials were examined to provide a fit to the data. Two of the existing erosion models have been refined to predict erosion wear of non-metallic materials due to solid particle impacts. The models allow variable particle size and velocity, material hardness, and impact angles with the results yielding erosion mass and volume losses of the materials investigated.

An improved CFD/experimental combined methodology for the calibration of empirical erosion models

A significant source of uncertainty in CFD-based erosion prediction is represented by the erosion model, used to turn the particle-wall impingement characteristics into an estimate of the removal of material. In engineering computations, frequent use is made of empirical erosion models obtained by fitting the experimental results of air-solid jet impingement tests. However, since the applicability conditions of these models are often unknown or unavailable to the users of CFD codes, they are frequently misapplied, producing not only uncertain, but at times also highly inaccurate wear estimates. As part of his PhD thesis defended at the University of Tulsa in 2016, Amir Mansouri proposed a methodology to calibrate the coefficients of an empirical erosion correlation by combining experimental data and CFD results of a slurry jet impingement test. This methodology provided an effective way to overcome the criticisms of using empirical erosion models taken from the literature without facing the complexity and the high computational burden of a multiscale, physically-based approach, in which the micro-scale mechanical interactions between the particles and the target surface are resolved according to the fundamental laws of damage mechanics. This paper presents an improved formulation of Mansouri's methodology, which not only increases the calibration accuracy of the empirical erosion equation, but also enhances the reliability of the CFD-based erosion prediction model as a whole. To this purpose, numerical simulations were supported by in-house slurry jet impingement experiments on an aluminum sample and curved Glass Reinforced Epoxy samples.

Outcomes and Tendon Integrity After Arthroscopic Treatment for Articular-Sided Partial-Thickness Tears of the Supraspinatus Tendon: Results at Minimum 2-Year Follow-Up.

Background:The best surgical treatment option for symptomatic moderate- to high-grade articular-sided partial-thickness rotator cuff tears (PTRCTs) is still controversial.Purpose/Hypothesis:The purpose of this study was to evaluate patient-reported and clinical outcomes and tendon integrity after arthroscopic debridement or repair for PTRCTs at a minimum of 2 years postoperatively. We hypothesized that the overall outcomes would be positive, showing pain relief, good shoulder function, and high tendon integrity.Study Design:Cohort study; Level of evidence, 3.Methods:We evaluated 30 patients (16 men, 14 women; mean age, 51 years) who underwent arthroscopic treatment for symptomatic PTRCTs (Ellman grades 2 and 3). Debridement was performed in 15 patients, and arthroscopic tendon repair was performed in the remaining 15 patients. Patients completed the Constant score; American Shoulder and Elbow Surgeons (ASES) shoulder score; Western Ontario Rotator Cuff Index; Simple Shoulder Test; and visual analog scale (VAS) for pain, function, and satisfaction. In addition, patients were examined clinically (range of motion, impingement tests, rotator cuff tests, and tests for the long head of the biceps tendon), and morphologic assessment of rotator cuff integrity was performed using direct magnetic resonance arthrography and was classified according to Sugaya.Results:The mean follow-up period was 55 months. The patient-reported outcome measures showed high patient satisfaction, reduction in persistent pain, and good shoulder function. Linear regression analysis showed that the debridement group had significantly better results on the Constant (bias-corrected and accelerated [BCa] 95% CI, 4.20-26.30), ASES (BCa 95% CI, 5.24-39.26), and VAS (pain: BCa 95% CI, 0.13-3.62; function: BCa 95% CI, 1.04-4.84; satisfaction: BCa 95% CI, 0.14-6.28) scores than did the repair group. At follow-up, there was no significant difference between the groups in clinical testing results. Good supraspinatus tendon integrity was seen in most patients: Sugaya classification grade 1 in 13 patients, grade 2 in 11 patients, and grade 3 in 6 patients.Conclusion:Midterm results after arthroscopic debridement and repair for PTRCTs showed high patient satisfaction, good shoulder function, and high tendon integrity for both procedures. Patients who underwent arthroscopic debridement had higher Constant, ASES, and VAS scores compared with patients who underwent tendon repair.