Mechanical property of U-Shaped 65Mn steel bumpers for seismic base isolation

This study proposes a novel U-shaped 65Mn steel bumper as the displacement restraining device for base-isolated structures with laminated elastomeric rubber bearings.A series of bumpers with different geometric parameters were designed and tested under monotonic and cyclic quasi-static loading protocols.The experimental results from a total of 232 specimens were analyzed to develop an analytical model to calculate the backbone curve and the maximum elastic restoring force for U-shaped 65Mn bumpers.Thus,the analytical equations to calculate the elastic,hardening,and unloading stiffness of U-shaped 65Mn bumpers,as well as their maximum elastic restoring force,are validated by using an additional ten groups of bumpers with varying radiuses.These analytical equations can accurately predict the mechanical parameters of U-shaped 65Mn steel bumpers for a design purpose.

Buried bumper syndrome:A critical analysis of endoscopic release techniques

Buried bumper syndrome(BBS)is the situation in which the internal bumper of the gastrostomy tube,due to prolonged compression of the tissues between the external and the internal bumper,migrates from the gastric lumen into the gastric wall or further,into the tract outside the gastric lumen,ending up anywhere between the stomach mucosa and the surface of the skin.This restricts liquid food from entering the stomach,since the internal opening is obstructed by gastric mucosal overgrowth.We performed a comprehensive search of the PubMed literature to retrieve all the case-reports and case-series referring to BBS and its management,after which we focused on the endoscopic techniques for releasing the internal bumper to re-establish the functionality of the tube.From the“push”and the“push and pull T”techniques to the most sophisticated-using high tech instruments,all 10 published techniques have been critically analysed and the pros and cons presented,in an effort to optimize the criteria of choice based on maximum efficacy and safety.

基于Bumper Mode的Landsat-5数据图像校正与补偿算法设计与实现

2002年Landsat-5星上TM扫描仪出现了扫描装置同步问题,为此美国宇航局(NASA)调整了TM扫描仪的工作模式,消除了上述问题,但同时造成了图像数据正反扫描不能对齐和错行的问题。本文针对目前Landsat-5卫星Bumper Mode模式下出现的问题进行了详细分析,完成了快速几何校正和补偿的算法设计与软件实现。并通过对Landsat-5多轨零级图像和移动窗图像处理加以验证,获得了良好的效果。为同类遥感卫星传感器出现相似问题提供了一条简便、快速的解决途径。

基于DSP5402的磁铁电源数据采集控制模块的设计

介绍了一种基于DSP处理器TM S320VC 5402的磁铁电源电流数据采集控制模块,给出了模块的硬件组成和软件设计。目前该控制模块已应用在H IRFL-CSR主环的Bum per磁铁电源控制中。

Gastroenteric tube feeding: Techniques, problems and solutions

Gastroenteric tube feeding plays a major role in the management of patients with poor voluntary intake,chronic neurological or mechanical dysphagia or gut dysfunction,and patients who are critically ill.However,despite the benefits and widespread use of enteral tube feeding,some patients experience complications.This review aims to discuss and compare current knowledge regarding the clinical application of enteral tube feeding,together with associated complications and special aspects.We conducted an extensive literature search on PubMed,Embase and Medline using index terms relating to enteral access,enteral feeding/nutrition,tube feeding,percutaneous endoscopic gastrostomy/jejunostomy,endoscopic nasoenteric tube,nasogastric tube,and refeeding syndrome.The literature showed common routes of enteral access to include nasoenteral tube,gastrostomy and jejunostomy,while complications fall into four major categories:mechanical,e.g.,tube blockage or removal;gastrointestinal,e.g.,diarrhea;infectious e.g.,aspiration pneumonia,tube site infection;and metabolic,e.g.,refeeding syndrome,hyperglycemia.Although the type and frequency of complications arising from tube feeding vary considerably according to the chosen access route,gastrointestinal complications are without doubt the most common.Complications associated with enteral tube feeding can be reduced by careful observance of guidelines,including those related to food composition,administration rate,portion size,food temperature and patient supervision.

Buried bumper syndrome:A complication of percutaneousendoscopic gastrostomy

Percutaneous endoscopic gastrostomy(PEG) is a widely used method of nutrition delivery for patients with longterm insufficiency of oral intake. The PEG complication rate varies from 0.4% to 22.5% of cases, with minor complications being three times more frequent. Buried bumper syndrome(BBS) is a severe complication of this method, in which the internal fixation device migrates alongside the tract of the stoma outside the stomach. Excessive compression of tissue between the external and internal fixation device of the gastrostomy tube is considered the main etiological factor leading to BBS. Incidence of BBS is estimated at around 1%(0.3%-2.4%). Inability to insert, loss of patency and leakage around the PEG tube are considered to be a typical symptomatic triad. Gastroscopy is indicated in all cases in which BBS is suspected. The depth of disc migration in relation to the lamina muscularis propria of the stomach is critical for further therapy and can be estimated by endoscopic or transabdominal ultrasound. BBS can be complicated by gastrointestinal bleeding, perforation, peritonitis, intra-abdominal and abdominal wall abscesses, or phlegmon, and these complications can lead to fatal outcomes. The most important preventive measure is adequate positioning of the external bolster. A conservative approach should be applied only in patients with high operative risk and dismal prognosis. Choice of the method of release is based on the type of the PEG set and depth of disc migration. A disc retained inside the stomach and completely covered by the overgrowing tissue can be released using some type of endoscopic dissection technique(needle knife, argon plasma coagulation, or papillotome through the cannula). Proper patient selection and dissection of the overgrowing tissue are the major determinants for successful endoscopic therapy. A disc localized out of the stomach(lamina muscularis propria) should be treated by a surgeon.

First report of colonoscopic closure of a gastrocolocutaneous PEG migration with over-the-scope-clip-system

Percutaneous endoscopic gastrostomy(PEG) is a common practice for long-term nutrition of patients who are unable to take oral food. We report of an 85-year old man with a history of recurrent larynx carcinoma and hemicolectomy many years ago due to unknown reason. Laryngectomy was indicated. Preoperatively a PEG was inserted endoscopically after an abdominal ultrasonography without abnormal findings. Few months after PEG insertion, the patient was evaluated for diarrhea and insufficient feeding without signs of infection or peritonism. An upper endoscopy and computed tomography scan confirmed a buried bumper syndrome with migration of the PEG tube into the colon as a rare complication. He underwent successful colonoscopic removal of the internal bumper and closure of the colonic orifice of the fistula with the over-the-scope-clip system(OTSC). OTSC is an endoscopic device for treatment of bleeding, perforation, leak and fistula in the gastrointestinal tract. To the best of our knowledge, this is the first report of the use of OTSC for colonoscopic closure of a gastrocolocutaneous fistula due to a buried bumper syndrome with transcolonic PEG tube migration.

Material selection of polymeric composite automotive bumper beam using analytical hierarchy process

Selection of materials,as an area of design research,has been under considerable interest over the years.Materials selection is one of the most important activities in the product development process.Inappropriate decision of materials can cause the product to be reproduced or remanufactured.To avoid this circumstance,one of the useful tools that can be employed in determining the most appropriate material is analytical hierarchy process(AHP).To illustrate the application of AHP,six different types of composite materials were considered.The most appropriate one for suitability of use in manufacturing automotive bumper beam was determined by considering eight main selection factors and 12 sub-factors.The AHP analysis reveals that the glass fibre epoxy is the most appropriate material because it has the highest value(25.7%,mass fraction) compared with other materials.The final material is obtained by performing six different scenarios of the sensitivity analysis.It is proved that glass fibre epoxy is the most optimum decision.

Novel endoscopic management of buried bumper syndrome in percutaneous endoscopic gastrostomy: The Olympus Hook Knife

Buried bumper syndrome(BBS) is an uncommon but serious complication of percutaneous endoscopic gastrostomy. It involves the internal fixation device, or "bumper", migrating into the gastric wall and subsequent mucosal overgrowth. We described a case series of four patients with BBS treated with a novel endoscopic technique using a Hook Knife between June 2016 and February 2017. The Hook Knife is a rotating L-shaped cutting wire designed for hooking tissue and pulling it away from the gastric wall towards the lumen. The technique was successful in all four cases with no complications. Each patient was discharged on the day of treatment. The Hook Knife is a manoeuvrable, safe and effective device for endoscopic removal of buried bumpers and could avoid surgery in a high risk group of patients. To our knowledge this technique has not been described previously. We suggest that this technique should be added to the treatment algorithms for managing BBS.

APPLICATION OF ARCHITECTURE- BASED NEURAL NETWORKS IN MODELING AND PARAMETER OPTIMIZATION OF HYDRAULIC BUMPER

The dynamic working process of 52SFZ-140-207B type of hydraulic bumper isanalyzed. The modeling method using architecture-based neural networks is introduced. Using thismodeling method, the dynamic model of the hydraulic bumper is established; Based on this model thestructural parameters of the hydraulic bumper are optimized with Genetic algorithm. The result showsthat the performance of the dynamic model is close to that of the hydraulic bumper, and the dynamicperformance of the hydraulic bumper is improved through parameter optimization.

Light weight replacement and the optimization design of bumper beam based on crash safety

Bumper beam is one of the key structural parts,which plays an important role in the frontal crashes of automobile.With the global trend of light-weighted automotive parts,the light weight of bumper beam attracts extensive attention of automobile manufacturers,and hot stamping technology with significant weight advantage has become one of the main light weight measures for bumper beam.The quasi-static press,low speed crash and frontal crash simulation models of bumper beam were established according to its actual working conditions in the automobile crashes.The feasibility of replacing normal steel bumper beam with hot stamping bumper beam was analyzed.Meanwhile,the stiffeners in the front face of hot stamping bumper beam were optimized with topography optimization in order to further improve its performances.

基于CAE分析的汽车后盖匹配的基准优化方案

汽车后盖存在易变形问题一直影响到项目的开发和匹配,难以实现DTS(Dimension Technical Specification)要求。本文针对后盖易变形的特点,基于CAE的分析,通过基准的优化,给出最佳的基准分布方案,实现零件与实车匹配基准一致性。达到DTS配合要求。

A study on light-aging resistance of instrument panel materials and bumper materials on the automobile

The light-aging test method commonly used in the automotive industry is utilized to carry out light- aging research on automotive instrument panel （IP） materials and bumper materials. On one hand, the impacts of common light-aging test methods on aging degree of automotive component materials are reviewed; on the other hand, the light-aging resistances of different component materials are compared. The results show that, for light-aging behavior of IP materials, the aging degree of the third test method is not severer than that of the second method, but it is severer than that of the first method. The light-aging resistance of IP material A is al- most the same as that of IP material B. With reference to light-aging behavior of bumper materials, the aging de- gree of three common test methods indicates that the aging degree of the sixth test method is not severer than that of the fourth method, but it is severer than that of the fifth method. The light-aging resistance of bumper material D is superior to that of bumper material C.

Numerical modeling and analysis of the mechanism of a novel shock wave regulator for impact test

Based on the concept of hydraulic dissipation of kinetic energy, a novel shock wave regulator, which is composed of a damper and an extemally triggered valve, is presented with thorough analyses on its working mechanism. By establishing motion equations of each component of the regulator and simulating the dynamic behavior of the whole system, the shock wave regulator is demonstrated numerically to be able to change the width and amplitude of shock pulses. Prompt and easy adjustment can be achieved by changing the equivalent flow area of damping orifices and consequently the closing velocity of the flow area of a valve, which makes it applicable to different impact testing.

美国BUMPER代码在航天飞机防护设计中的最新应用

美国的BUMPER是迄今为止应用得最成功的微流星体和空间碎片风险评估与防护设计代码,在航天飞机与国际空间站防护设计中起到举足轻重的作用。针对不断变化的空间碎片环境以及优化设计的需求。

Advances in endoscopic therapy using grasping-type scissors forceps(with video)

Endoscopic submucosal dissection(ESD)is a globally accepted minimally invasive therapy for early-stage gastrointestinal tract tumors.Although numerous electrosurgical knives have been developed for ESD,technical difficulties and high complication rates(bleeding and perforation)have limited their use worldwide.The grasping-type scissors forceps[clutch cutter(CC)]is the first forceps-type resection device developed with reference to hemostatic forceps.The aim was to allow easy and safe ESD throughout the gastro-intestinal tract,as a biopsy technique,using one device.The CC can grasp the target tissue accurately and pull it away from the underlying muscle layer prior to energizing the tissue,for safe and effective incision and hemostasis during ESD.Reported clinical studies showed that ESD using the CC(ESD-CC)is a safe(perforation rate:0%-3.6%;delayed bleeding rate:0%-4.2%),technically efficient(en-bloc resection rate:88.9%-100%),and single-device method for dissecting early-stage gastrointestinal tract tumors.The ESD-CC technique is simple and easy to learn because it can be completed simply by repeating the grasp,pull,and coagulate and/or incise actions using an electrosurgical current.The reported self-completion rate by nonexperts was significantly better with the CC than with conventional knives(61.7%vs 24.5%,respectively;P<0.001).Furthermore,the CC is used for other endoscopic therapies,such as endoscopic polypectomy for large pedunculated polyps,endoscopic myotomy for Zenker’s diverticulum,endoscopic treatment of buried bumper syndrome,and endoscopic necrosectomy for wall-off pancreatic necrosis.The initial reports using CC for these therapies have shown favorable results.In this review,we describe the structural features of the CC,how to use the instrument,efficacies of ESD-CC,and other unique endoscopic therapies using the CC.

Experimental Evaluation of the Attenuation Effect of a Passive Damper on a Road Vehicle Bumper

To mitigate the degree of damage to passengers caused by automobile collisions, a friction damper was built and used in experimental tests to test its effectiveness in impact energy attenuation. The study revealed that energy absorption capacity of a bumper can be improved with the addition of a friction damper. The results revealed that the addition of the friction damper to an automobile bumper to give a bumper-damper system could attenuate about 32.5 % more energy than with the bumper alone. It can be concluded that the effectiveness of automobile bumpers to withstand impact of vehicles by absorbing the kinetic energy from the impact can be improved with the use of a passive friction damper. That is, a passive friction damper system could be used to attenuate more road vehicle impact energy in collisions.

bumper=AmE fender?

在 LONGM AN LEXICON OF CONTEMPORARY ENGLISH(1981)p.639 Parts of vehicles(outside)项中可以看到图中有 bumper/AmE fender。同时在此书的“汉译本”《当代英汉分类详解词典》(胡作群主编,警官教育出版社,1992年)中也能看到“bumper/AmE fender 车挡,保险杠”的释义。

Electric Vehicle Bumper Crash Simulation based on ABAQUS

Taking the bumper of an electric vehicle as the research object,UG software was used to create the geometric model of bumper firstly. The HyperMesh was used as the pre processing software,and the finite element software ABAQUS was used to analyze the deformation and displacement of the bumper during the collision process,the crashworthiness of the bumper was improved by changing the thickness,this study provided a certain reference value for the design of bumper.