Experimental and numerical simulation study on the erosion behavior of the elbow of gathering pipeline in shale gas field

During the production period of shale gas, proppant particles and rock debris are produced together,which will seriously erode the elbows of gathering pipelines. In response to this problem, this paper takes the elbow of the gathering pipeline in the Changning Shale Gas Field as an example to test the erosion rate and material removal mechanism of the test piece at different angles of the elbow through experiments and compares the four erosion models with the experimental results. Through analysis, it is found that the best prediction model for quartz sand-carbon steel erosion is the Oka model. Based on the Oka model, FLUENT software was used to simulate and analyze the law of erosion of the elbow of the gas gathering pipeline under different gas flow velocities, gas gathering pressure, particle size, length of L1,and bending directions of the elbow. And a spiral pipeline structure is proposed to reduce the erosion rate of the elbow under the same working conditions. The results show that this structure can reduce erosion by 34%.

Elbow Dislocation in Children: About Two Cases and Review of the Literature

Background: Elbow dislocations in pediatric patients are rare injuries. This is a therapeutic emergency because a delay in treatment can have disastrous consequences on the functional level of the upper limb. Objective: To present the management of elbow dislocation in children in cases of limited resources. Presentation of the Cases: These were 2 older male children aged 7 and 9 years old, admitted to the emergency room for painful functional impotence of the right elbow after a fall and landing on the right hand. Clinical and radiological examinations were in favor of posterior elbow dislocations. The reductions were carried out under sedation and immobilization in Jersey. According to Robert’s criteria, the functional result was excellent in both patients. Conclusion: Emergency reduction and immobilization whatever the means ensure an excellent functional prognosis even in cases of limited resources.

Peri-articular elbow fracture fixations with magnesium implants and a review of current literature: A case series

BACKGROUND In recent years,the use of Magnesium alloy implants have gained renewed popularity,especially after the first commercially available ConformitéEuropéenne approved Magnesium implant became available(MAGNEZIX®CS,Syntellix)in 2013.AIM To document our clinical and radiographical outcomes using magnesium implants in treating peri-articular elbow fractures.METHODS Our paper was based on a retrospective case series design.Intra-operatively,a standardized surgical technique was utilized for insertion of the magnesium implants.Post–operatively,clinic visits were standardized and physical exam findings,functional scores,and radiographs were obtained at each visit.All complications were recorded.RESULTS Five patients with 6 fractures were recruited(2 coronoid,3 radial head and 1 capitellum).The mean patient age and length of follow up was 54.6 years and 11 months respectively.All fractures healed,and none exhibited loss of reduction or complications requiring revision surgery.No patient developed synovitis of the elbow joint or suffered electrolytic reactions when titanium implants were used concurrently.CONCLUSION Although there is still a paucity of literature available on the subject and further studies are required,magnesium implants appear to be a feasible tool for fixation of peri-articular elbow fractures with promising results in our series.INTRODUCTION In recent years,the use of Magnesium alloy implants in orthopaedic surgeries have gained renewed popularity.Apart from being bioabsorbable,negating the need for implant removal,magnesium also has good osteoconductive properties[1-4].Biomechanically,it exhibits greater biomechanical strength than any pre-existing polymers,and reduces the stress-shielding effect associated with titanium and steel implants as it has a Young’s modulus closer to bone[4].Currently,the main utility of magnesium implants in the orthopaedic community is within the foot and ankle community where satisfactory results have been reported with its utility in forefoot osteotomies[5-7].However,its utility in the setting of orthopaedic trauma has been steadily increasing[8].Our study aims to document our clinical and radiographical outcomes using magnesium implants to treat peri-articular elbow fractures.To our knowledge,our study is the first study analyzing outcomes in radial head and coronoid fractures in the English literature.

Clinical study on improving the diagnostic accuracy of adult elbow joint cartilage injury by multisequence magnetic resonance imaging

BACKGROUND Due to frequent and high-risk sports activities,the elbow joint is susceptible to injury,especially to cartilage tissue,which can cause pain,limited movement and even loss of joint function.AIM To evaluate magnetic resonance imaging(MRI)multisequence imaging for improving the diagnostic accuracy of adult elbow cartilage injury.METHODS A total of 60 patients diagnosed with elbow cartilage injury in our hospital from January 2020 to December 2021 were enrolled in this retrospective study.We analyzed the accuracy of conventional MRI sequences(T1-weighted imaging,T2-weighted imaging,proton density weighted imaging,and T2 star weighted image)and Three-Dimensional Coronary Imaging by Spiral Scanning(3D-CISS)in the diagnosis of elbow cartilage injury.Arthroscopy was used as the gold standard to evaluate the diagnostic effect of single and combination sequences in different injury degrees and the consistency with arthroscopy.RESULTS The diagnostic accuracy of 3D-CISS sequence was 89.34%±4.98%,the sensitivity was 90%,and the specificity was 88.33%,which showed the best performance among all sequences(P<0.05).The combined application of the whole sequence had the highest accuracy in all sequence combinations,the accuracy of mild injury was 91.30%,the accuracy of moderate injury was 96.15%,and the accuracy of severe injury was 93.33%(P<0.05).Compared with arthroscopy,the combination of all MRI sequences had the highest consistency of 91.67%,and the kappa value reached 0.890(P<0.001).CONCLUSION Combination of 3D-CISS and each sequence had significant advantages in improving MRI diagnostic accuracy of elbow cartilage injuries in adults.Multisequence MRI is recommended to ensure the best diagnosis and treatment.

基于ABAQUS软件ELBOW单元的LNG管道有限元模拟

本文运用ABAQUS软件中的ELBOW单元进行LNG管道有限元模拟,并与CAESAR II计算结果对比,最大应力出现在Π型弯下侧弯头处,差值比小于5%,可见ELBOW单元可用于管道应力分析。进一步分析了管道温度对应力的影响,结果表明,温度变化对二次应力和操作应力影响较大,对一次应力无影响。

Atlas of Elbow Soft Tissue Pathologies Using Magnetic Resonance Imaging at the Saint Camille Hospital in Ouagadougou and the Polyclinique Notre Dame de la Paix (Burkina Faso)

Introduction: The elbow is a superficial joint, particularly exposed to direct impact, forced movement, and overstrain. Our work aimed to study magnetic resonance imaging (MRI) pathologies of the soft tissues of the elbow through illustrative cases. Methodology: This was a retrospective and prospective cross-sectional study covering a period of one year, from June 2020 to June 2021, at the Saint Camille Hospital in Ouagadougou and the Polyclinique Notre Dame de la Paix. Results: In general, this study found that the pathologies diagnosed on MRI were lateral epicondylitis, subcutaneous type V elbow lipoma and liposarcoma, anteromedial cortical fracture of the radial cup, cortical detachment fracture of the lateral epicondylitis, medial epicondylitis, villonodular articular synovitis, simple dermo-hypodermatitis, sequellar fibrosis of the ulnar nerve, Workman's syndrome (median and ulnar nerves) and osteoarthritis of the elbow. Lateral epicondylitis was the most frequent pathology, and most patients consulted for elbow pain predominantly associated with pressure on the epicondyle, with relative functional impotence and, occasionally, elbow swelling. Conclusion: MRI, as a complement to ultrasound and radiography, remains the most informative examination for exploring soft-tissue pathologies of the elbow.

Dynamic behavior of outburst two-phase flow in a coal mine T-shaped roadway:The formation of impact airflow and its disaster-causing effect

The study of the dynamic disaster mechanism of coal and gas outburst two-phase flow is crucial for improving disaster reduction and rescue ability of coal mine outburst accidents.An outburst test in a T-shaped roadway was conducted using a self-developed large-scale outburst dynamic disaster test system.We investigated the release characteristics of main energy sources in coal seam,and obtained the dynamic characteristics of outburst two-phase flow in a roadway.Additionally,we established a formation model for outburst impact flow and a model for its flow in a bifurcated structure.The results indicate that the outburst process exhibits pulse characteristics,and the rapid destruction process of coal seam and the blocking state of gas flow are the main causes of the pulse phenomenon.The outburst energy is released in stages,and the elastic potential energy is released in the vertical direction before the horizontal direction.In a straight roadway,the impact force oscillates along the roadway.With an increase in the solid–gas ratio,the two-phase flow impact force gradually increases,and the disaster range extends from the middle of the roadway to the coal seam.In the area near the coal seam,the disaster caused by the two-phase flow impact is characterized by intermittent recovery.In a bifurcated roadway,the effect of impact airflow on impact dynamic disaster is much higher than that of two-phase flow,and the impact force tends to weaken with increasing solid-gas ratio.The impact force is asymmetrically distributed;it is higher on the left of the bifurcated roadway.With an increase in the solid-gas ratio,the static pressure rapidly decreases,and the bifurcated structure accelerates the attenuation of static pressure.Moreover,secondary acceleration is observed when the shock wave moves along the T-shaped roadway,indicating that the bifurcated structure increases the shock wave velocity.

K-Hyperparameter Tuning in High-Dimensional Space Clustering:Solving Smooth Elbow Challenges Using an Ensemble Based Technique of a Self-Adapting Autoencoder and Internal Validation Indexes

k-means is a popular clustering algorithm because of its simplicity and scalability to handle large datasets.However,one of its setbacks is the challenge of identifying the correct k-hyperparameter value.Tuning this value correctly is critical for building effective k-means models.The use of the traditional elbow method to help identify this value has a long-standing literature.However,when using this method with certain datasets,smooth curves may appear,making it challenging to identify the k-value due to its unclear nature.On the other hand,various internal validation indexes,which are proposed as a solution to this issue,may be inconsistent.Although various techniques for solving smooth elbow challenges exist,k-hyperparameter tuning in high-dimensional spaces still remains intractable and an open research issue.In this paper,we have first reviewed the existing techniques for solving smooth elbow challenges.The identified research gaps are then utilized in the development of the new technique.The new technique,referred to as the ensemble-based technique of a self-adapting autoencoder and internal validation indexes,is then validated in high-dimensional space clustering.The optimal k-value,tuned by this technique using a voting scheme,is a trade-off between the number of clusters visualized in the autoencoder’s latent space,k-value from the ensemble internal validation index score and one that generates a value of 0 or close to 0 on the derivative f″′(k)(1+f′(k)^(2))−3 f″(k)^(2)f″((k)2f′(k),at the elbow.Experimental results based on the Cochran’s Q test,ANOVA,and McNemar’s score indicate a relatively good performance of the newly developed technique in k-hyperparameter tuning.

一种新的临时心脏起搏器置入方法及综合护理策略

目的:探讨经肘正中静脉行临时心脏起搏器置入术的可行性、安全性、舒适度和情感差异,并总结相应的综合护理策略。方法:选取2020年6月—2022年3月于我院行临时心脏起搏器置入术病人136例,采用随机数字表法分为股静脉组(F组)和肘正中静脉组(M组),各68例。统计两组病人的手术成功率、电极脱位率以及并发症发生率,并采用Kolcaba舒适状况量表(GCQ)、Zung焦虑自评量表(SAS)和Zung抑郁自评量表(SDS)进行舒适状况评价及情感评定,总结综合护理经验。结果:两组病人手术均成功,与M组比较,F组的电极脱位率和并发症发生率更高(P<0.05)。术后,与F组比较,M组GCQ评分更高(P<0.05),而SAS评分和SDS评分更低(P<0.05),相应的护理策略可以改善M组病人GCQ评分,差异均有统计学意义(P<0.05),但对F组GCQ改善不明显,差异无统计学意义(P>0.05);同时两组SAS评分和SDS评分均进一步降低,差异有统计学意义(P<0.05)。结论:与传统股静脉路径比较,经肘正中静脉置入临时心脏起搏器疗效确切,安全性更高、舒适度更佳且情绪更平稳,辅助于综合护理对病人获益更大。

Simple lateral elbow dislocation:A case report

BACKGROUND Simple lateral elbow dislocation(SLED)is a rare type of elbow dislocation;however,its treatment may be complicated by accompanying soft tissue or neurovascular damage.Herein,we report a rare case of SLED managed secondarily with open reduction and soft tissue repair following failure of closed reduction.CASE SUMMARY A 67-year-old woman suffered SLED after falling on her outstretched left hand with her elbow extended.She developed pain,swelling,and movement restriction in the elbow;there were no neurovascular symptoms,except for numbness in the 4th and 5th digits.Radiologic investigation confirmed the SLED,and a closed reduction under anesthesia was performed.The follow-up radiographs at 1-wk revealed failure of reduction;accordingly,open reduction with lateral collateral ligament and common extensor origin repair were carried out.The patient regained full elbow range of motion by six weeks.CONCLUSION Adequate concentric reduction for SLED,conservatively or surgically,reduces complications and provides a more functional joint.

术后早期综合康复对儿童青少年肱骨髁上骨折伴尺神经损伤的效果

目的观察术后早期综合康复对并发尺神经损伤的肱骨髁上骨折儿童青少年的肘关节功能障碍与尺神经损伤的效果。方法2016年1月至2021年12月在中国中医科学院望京医院治疗的并发尺神经损伤的肱骨髁上骨折术后的儿童青少年49例,随机分为对照组(n=24)和治疗组(n=25)。对照组采用蜡敷治疗和针灸治疗,治疗组采用药物熏蒸、关节松动术及肌电生物反馈治疗,治疗12周。治疗前后分别采用美国特种外科医院肘关节评定表(HSS)和英国医学研究院神经外伤学会报告(MCRR)进行评估。结果治疗后,两组HSS评分均显著升高(|t|>8.345,P<0.001),治疗组HSS评分显著高于对照组(t=4.536,P<0.001),治疗组治疗前后HSS评分差值高于对照组(t=3.717,P<0.05)。治疗组尺神经恢复优良率高于对照组(χ^(2)=5.975,P<0.05)。结论术后早期综合康复可改善并发尺神经损伤的肱骨髁上骨折儿童青少年的肘关节功能,促进尺神经恢复。

肘关节后囊损伤后愈合不同阶段的生物力学

目的评估关节后囊损伤愈合过程中不同阶段,肘关节内部软组织的力学行为。方法建立考虑肌肉主动行为的肘关节有限元模型,模拟肘关节在无损伤和关节后囊损伤后2、4、6、8周时屈曲运动,分析关节囊、尺骨软骨和韧带von Mises等效应力变化。结果无损伤以及损伤后2、4、6、8周时,关节囊在肘关节屈曲60°时应力分别为8.23、7.87、8.27、8.99、10.5 MPa。在肘关节屈曲30°时,与无损伤相比,损伤后2、4、6、8周时尺骨软骨应力分别为增加13.0%、28.3%、41.3%和45.7%。与损伤后2周相比,损伤后4周时桡侧副韧带在屈曲15°、30°、45°、60°、75°时应力分别减少12.5%、22.2%、13.6%、3.2%和10.6%。结论肘关节后囊损伤愈合过程中,骨与软组织生物力学特征变化显著。研究结果可为关节囊挛缩的预防和治疗以及康复辅具的开发提供理论依据。

关节镜联合肘管扩大成型术治疗肘关节骨性关节炎伴肘管综合征疗效观察

目的探讨关节镜联合肘管扩大成型术治疗肘关节骨性关节炎伴肘管综合征的临床疗效。方法选择2020年9月至2023年8月河北省沧州中西医结合医院骨外科收治的101例肘关节骨性关节炎伴肘管综合征患者为研究对象,按照手术方式不同将患者分为观察组(n=51)和对照组(n=50)。观察组患者采用关节镜联合肘管扩大成型术,对照组患者采用常规肘管扩大成型术。观察并记录2组患者的手术时间、术中出血量、住院时间、并发症发生情况。分别于术前、术后6个月时,采用Mayo肘关节功能评分(MEPS)评估2组患者的肘关节功能,采用日常生活活动能力评定表(ADL)评估2组患者的日常生活能力,采用视觉模拟评分(VAS)评估2组患者的疼痛程度;使用关节量角器测量肘关节旋前度数、旋后度数、屈伸度数,评估2组患者的肘关节活动度;使用Keypoint型肌电图仪检测小指展肌的复合肌肉动作电位(CMAP)、尺神经的神经传导速度(NCV)、运动诱发电位潜伏期(MEPLP),评估2组患者神经恢复情况。结果观察组患者的手术时间、住院时间显著短于对照组,术中出血量、并发症显著少于对照组(P<0.05)。术前,观察组和对照组患者的MEPS、ADL、VAS评分比较差异无统计学意义(P>0.05);术后6个月,观察组患者的MEPS、ADL评分显著高于对照组,VAS评分显著低于对照组(P<0.05)。术前,观察组和对照组患者的旋前度数、旋后度数、屈伸度数比较差异无统计学意义(P>0.05);术后6个月,2组患者的旋前度数、旋后度数、屈伸度数显著高于术前(P<0.05),观察组和对照组患者的旋前度数、旋后度数、屈伸度数比较差异无统计学意义(P>0.05)。术前,观察组和对照组患者的CMAP、NCV、MEPLP比较差异无统计学意义(P>0.05);术后6个月,观察组患者的CMAP、NCV显著高于对照组,MEPLP显著低于对照组(P<0.05)。结论常规肘管扩大成型术、关节镜联合肘关节扩大成型术均可改善肘关节骨性关节炎伴肘管综合征患者的肘关节活动度,但后者损伤更小,恢复更快,在提升肘关节功能及日常生活能力、减轻疼痛程度、调节肌电图检查指标等方面效果更佳,且并发症更少。

基于CFD-DPM模型的高浓度矿浆输送90°弯管冲蚀磨损特性研究

在工况条件较为复杂的矿浆输送管道中,造成管道失效的主要原因是冲蚀磨损。管道中的冲蚀主要发生在典型弯管、变径管等流向或结构发生变化的位置。本文基于CFD-DPM耦合模型,模拟研究了复杂工况下液固两相流中的固体颗粒粒径、矿浆流速、矿浆浓度对某选矿厂矿浆输送管道的90°弯管冲蚀磨损的影响。结果表明:弯管的冲蚀磨损最为严重,90°弯管处的冲蚀磨损速率与矿浆浓度呈线性关系;流速达到5 m/s时90°弯管处的冲蚀磨损速率变化幅度较大;粒径在0.0374~0.0750 mm范围时,90°弯管处的冲蚀磨损速率无明显变化,粒径达到0.150 mm后90°弯管处的冲蚀磨损速率变化幅度较大。研究结果可实现矿浆输送管道冲蚀磨损区域和磨损速率的有效评估,为管道安全运维和寿命预测提供技术依据。

基于CFD的立式天然气弯管气固两相流冲蚀数值模拟分析

采用CFD-DPM模型,在不同连续相流体流速(v)、固体颗粒直径(d)、弯径比(R/D)的工况下,研究天然气管道内气固两相流颗粒冲蚀率与冲蚀样貌。模拟结果表明,随着v增加,高冲蚀区域逐渐变大,冲蚀范围逐步向下游移动,v>20 m/s时,冲蚀样貌基本不变,颗粒冲蚀率迅速增加;d<30μm时,冲蚀范围较为分散,弯头内侧与外侧均有分布,随着d的进一步增大,流体影响减小,冲蚀范围集中于弯头外侧,颗粒冲蚀率迅速下降,并趋于平缓;R/D<3时,随着R/D的增加,弯管内壁颗粒冲蚀率迅速减小,但R/D>3时,颗粒冲蚀率下降速度放缓。

研究测量前脂肪垫与肱骨皮质角度诊断肘关节骨折的意义

目的研究测量肘关节标准侧位片中前脂肪垫与肱骨皮质间角度,探讨诊断肘关节骨折引起的前脂肪垫征阳性角度的临界值,从而帮助骨科医生确定治疗方案。方法从CT检查确诊的肘关节外伤引起的骨折与未骨折患者中,各选取X线片侧位中前脂肪垫征阳性患者50例,进行ROC曲线回顾性分析。结果前脂肪垫与肱骨皮质夹角为15.6°,灵敏度+特异度值最大。讨论前脂肪垫与肱骨皮质夹角≥15.6°为骨折临界值,为基层医院骨科医生治疗提供了清晰、客观的诊断依据。

肘关节置换术后定制假体翻修1例

患者,男,65岁,15年前因右肘创伤性关节炎在当地医院行肘关节置换术治疗,2023年9月27日再次摔伤右肘部,于10月6日至我院就诊。X线片显示:右肘关节置换术后假体周围骨折,骨折移位明显伴假体松动。予3D打印定制假体,在颈丛+吸入复合麻醉下行翻修术治疗。

基于改进K-means算法的物流配送中心选址研究

针对传统K-means算法需要主观设定K值及无法处理类别型数据问题,文章运用肘部法及轮廓系数法确定合理K值,对类别型数据采取独热编码(One-Hot Encoding)转换为可以处理的连续型数据,并将其运用到在物流配送中心选址中;并综合考虑多种类别的影响因素,构建了相应的影响因素指标体系,提出的模型能够识别输入数据的数值型及类别型数据,实现样本的有效聚类。相关的案例分析结果表明,相比传统K-means聚类,文章的改进K-means算法选址结果可使物流总成本降低8.76%,运营成本降低14.85%,固定成本降低8.09%,效果显著。

肘关节造影闭合复位经皮克氏针固定治疗儿童肱骨外髁骨折

目的探讨肘关节造影闭合复位经皮克氏针固定治疗儿童肱骨外髁骨折的疗效。方法采用肘关节造影闭合复位经皮克氏针固定治疗24例肱骨外髁骨折患儿。记录骨折愈合情况、并发症发生情况、肘关节恢复情况,末次随访时采用Flynn肘关节评分标准评价疗效。结果患儿均获得随访,时间18~24个月。骨折均愈合,时间8~16周。术后未发生肘外翻畸形、肱骨外髁缺血性坏死、骨化性肌炎、缺血性肌挛缩以及神经症状等并发症。末次随访时,4例患儿肘关节功能未完全恢复正常,但不影响生活,Flynn肘关节评分等级均为良;20例肘关节功能均恢复至健侧水平,Flynn肘关节评分等级均为优。结论采用肘关节造影闭合复位经皮克氏针固定治疗儿童肱骨外髁骨折,术中能清楚显示儿童肱骨远端的软骨成分,有助于判断骨折的移位程度和闭合复位的质量,避免不必要的切开复位及并发症的发生。

一例小灵猫肘关节脱位合并掌骨创伤的救护

江西省野生动物救护中心收容救护1只受伤的小灵猫(Viverricula indica),通过一般检查、血液检查和影像学检查,确诊小灵猫右前肢肘关节外侧脱位合并掌部创伤。采用无菌清创、手术整复、科学护理等救护技术,2个月后小灵猫恢复健康,并成功放归野外。