Patients’perspectives on the conventional synthetic cast vs a newly developed open cast for ankle sprains

BACKGROUND Orthopedic physicians typically apply a cast to immobilize a body part that has been injured.There have been no significant structural changes or advances in synthetic casts since the development of the modern cast.The Opencast®is a recently developed type of cast that allows ventilation and direct visual inspection of the skin to avoid cast-related complications.Although this novel cast appears to have more benefits than the conventional synthetic cast,its clinical efficacy and advantages have not been established.AIM To investigate the clinical efficacy and advantages of the newly developed Opencast®based on patients’perspectives in those with ankle inversion injury.METHODS A specifically designed questionnaire consisting of 19 items was used to compare patients’opinions and concerns of the Opencast®and the conventional synthetic cast.The items were focused on subjective patient satisfaction,discomfort,and adverse effects while wearing the cast.Patients with an ankle inversion injury diagnosed as a high-grade ankle sprain were enrolled.The subjects were randomized and instructed to fill the questionnaire after wearing a synthetic cast or an Opencast®for 2 wk.They were then required to fill the questionnaire again,after switching to the alternative type of cast for 2 more weeks.RESULTS A total of 22 subjects participated in the study.The synthetic cast appeared to be more rigid and stable than the Opencast®,but there was no significant difference in the amount of pain relief.The likelihood of adverse effects when wearing the synthetic cast was significantly higher.Patient satisfaction tended to be rated higher after wearing the Opencast®.Opencast®showed more subjective vulnerability than the synthetic cast,but there was no significant difference in the redo rate.Patients were more anxious about removal of the synthetic cast than of the Opencast®.CONCLUSION The results indicate that the Opencast®could replace the conventional synthetic cast as it offers increased patient satisfaction,which would in turn increase compliance to treatment.

Construction of Dry Cover System for Prevention of Acid Mine Drainage at Mine Waste Dump in Open Cast Coal Mines, Indonesia

Acid Mine Drainage (AMD) which occurs when sulfide minerals are exposed to water and oxygen with an excavation is one of the serious environmental problems in the world. A dry cover system is generally constructed in waste dump for the prevention of AMD in Indonesia by virtue of low cost and availability of waste rocks for a cover layer. However, the failure of the system caused by the lack of information related to the construction of cover system in mines, which leads to AMD, has been reported recently in Indonesia. In this study, the field investigation was conducted in pit and waste dump in open cast coal mine in Indonesia with the aim of obtaining the information on the construction of a cover layer and backfilling conditions of waste rocks in the waste dump. The rock samples taken in two areas of the mine were analyzed by geochemical analysis and sequential extraction with acids. The results indicated that Net Acid Producing Potential (NAPP) of the rocks in the waste dump down to 100 cm depth in both areas was from 10 to 30 kg H2SO4/ton, suggesting that Potentially Acid Forming (PAF) was backfilled in a cover layer. The backfill of PAF was contrary to the concept of cover system, which caused the failure of constructing a cover layer. The cause of the failure was likely attributed to the shortage of cover rocks which are classified as Non Acid Forming (NAF) or the failure of proper placement of them by an operational problem in the areas. Moreover, the results of the extraction with acids suggested that the form of iron and sulfur has to be taken into account to discuss the occurrence of AMD.

Process for improving the ladle free- opening rate for high aluminum steel in continuous casting

Steel 20Mn23AlV is a type of high aluminum steel with a very low ladle free-opening rate. The aluminum composition of 20Mn23AlV ranges from 1.6% to 2.45% ,which is significantly higher than other types of steel. According to the real condition of 40 t ladle in steel-making plant of Baosteel Special Steel Company, previous works show that the key factors affecting the ladle free-opening rate of high aluminum steel in continuous casting are：sand material, accessories baking, ladle nozzle cleaning, the process and amount of adding sand, and the rate of argon stirring during refining. Therefore, improving the ladle filler sand quality, baking all of the raw materials, controlling the addition of ladle filler sand, cleaning the ladle nozzle, and optimizing argon stirring during the refining process can resolve the problem of a low ladle free-opening rate of high aluminum steel caused by the long ladle time of liquid steel.

Preparation of open-cell metal foams by investment cast

Metal foams are a new kind of materials with low densities and novel physical, mechanical, thermal, electrical and acoustic properties. They can be divided into closed and open cell structures. In this paper the open cell structures, called sponges, were treated. A new technique to manufacture sponges by plaster investment casting was described. Experimental results show that it is essential to make a sound plaster mould by casting plaster slurry into the polyurethane foams and infiltrate the open channels of the baked plaster mold by molten metal. The optimal processes include plaster slurry preparation, plaster mold baking, and molten metal infiltration. The sponge sample with porosity of 97% is presented.

Thermal properties of open-celled aluminum foams prepared by two infiltration casting methods

Contrastive research was carried out to study the thermal properties of open-celled aluminum foams prepared by counter-gravity infiltration casting system and the traditional process respectively.The experimental results show that the thermal conductivity coefficients of aluminum foams prepared by two different infiltration methods have similar increasing trend with the increase of particle size;along with the reducing porosity,the thermal conductivity coefficients will be enhanced oppositely.However,with the same particle size,the open-celled aluminum foam prepared by the former method has a higher thermal conductivity coefficient obviously.It is largely because that the sample prepared by counter-gravity infiltration casting has a lower void content and better dense crystallization of metal-matrix after the constant pressure process.

国内露天煤矿抛掷爆破拉斗铲倒堆工艺应用现状及前景

抛掷爆破拉斗铲倒堆工艺可以减少露天煤矿的设备数量,提升露天煤矿的生产能力,降低剥离费用,较传统的单斗卡车工艺具有明显的技术、经济优势。为进一步推动该工艺在国内的推广应用,阐述了该工艺的发展历程,总结了黑岱沟露天煤矿的应用情况及哈尔乌素露天煤矿采用抛掷爆破技术处理采空区的经验,分析了该工艺在国内应用面临的问题以及国内外露天煤矿的地质资源条件。结果表明:抛掷爆破拉斗铲倒堆工艺在国内取得了良好的应用效果,下一步需要重点优化抛掷爆破拉斗铲倒堆工艺参数,提高该工艺系统生产效率;与国外采用拉斗铲剥离的矿床特征类似,国内露天煤矿开采的煤层厚度多在25 m以上,主采煤层数多在1~3,煤层倾角多在10°以下,煤层顶板多为泥岩、砂岩等中硬以下岩石,顶板岩石普氏系数多在1~4,国内相当多的露天煤矿具备应用抛掷爆破拉斗铲倒堆工艺的有利条件,抛掷爆破拉斗铲倒堆工艺尤其是抛掷爆破剥离技术在国内露天煤矿具有广阔的应用前景。

DesignSpark与HyCast在快速熔模铸造CAE中应用实践

DesignSpark是开源的直接建模技术软件,HyCast是国内开发的多铸造方法铸造CAE软件。运用快速熔模铸造专利技术,采用DesignSpark设计3D模样、熔融沉积FDM打印PLA模样,粘接蜡质浇注系统,采用熔模铸造方法进行验证。结果表明,DesignSpark与HyCast可以用于熔模铸造CAE。

滇中引水工程现浇仰拱全工序施工装备设计与应用

为实现敞开式TBM掘进与现浇仰拱同步施工,提升现浇仰拱衬砌质量,缩短工程工期,结合长大敞开式TBM水工隧洞现浇仰拱施工边界条件,研制大跨径现浇仰拱全工序施工装备。从功能要求、主桥、支腿、前后爬坡轨、行走系统、仰拱衬砌等方面对现浇仰拱全工序施工装备开展详细设计,提出将主桥行车路面抬高,在主桥下部设置11个长度12 m功能作业区的创新思路,并在现场进行充分验证。工程实践表明:1)全工序现浇仰拱装备主桥支撑系统、行走驱动系统、模板浇筑系统使用效果初步达到设计预期;2)全工序现浇仰拱装备组装效率高、整体移动便捷、与现场施工工序契合度高、人员作业空间大,劳动强度低,施工进度最高可达到240 m/月,有效提升了TBM施工现浇仰拱技术的发展水平;3)全工序施工装备作为水工隧洞全新的工装,开创了新的施工工艺。但是该装备使本来狭窄的隧道显得更为拥挤,掘进施工交通流量受限,导致浇筑混凝土、钢筋、轨排的运输与TBM掘进物料运输之间的矛盾逐步显现,保障施工通道和TBM掘进有效进度匹配性的问题有待进一步研究。

跨干线公路低净空现浇梁门洞支架设计及应用

为优化跨干线公路低净空现浇梁门洞支架设计与施工方法,以安阳至罗山高速公路项目魏邱互通主线跨S310桥施工为工程背景,对跨公路现浇梁门洞支架的设计、施工方案等方面进行研究。利用Midas/Civil有限元软件对门洞支架的整体结构进行建模及验算分析,经验算分析,在各工况下,门洞支架强度及刚度均能满足要求。对施工工艺及交通组织进行了阐述,为类似的现浇梁门洞支架的设计与施工提供相关参考。

现浇梁组合支架技术

盘扣支架由于其安全性,便捷性,构件高标准化,使用寿命长,低成本等特点,现如今在建筑行业得到广泛运用。本工程项目为高速公路现浇箱梁,根据实际状况应用门洞及盘扣组合支架搭设现浇施工形式。并结合现场进行了方案设计与荷载分析、验证,同时对施工关键技术进行了阐述及探讨。通过对该技术的运用研究,充分表明了盘扣式支架施工安装和拆除工效高,安全性能高的技术优势,以及材料运用少,使用寿命长的低成本优势,为类似工程的方案运用提供参考。

宽幅现浇箱梁门洞式支架受力性能研究

为解决宽幅现浇梁在跨越道路交叉口时的支架设计难题,以杭州市通城大道快速路(机场高速—通彩互通)工程宽幅现浇箱梁施工为例,提出了2种不同的门洞式支架方案,建立其力学简化模型,对其整体受力、变形和稳定性进行验算。结果表明,方案A和方案B的分配梁和贝雷桁架主梁的验算结果一致,而采用方案A需要对圆心钢管的验算指标较多,需要满足截面正应力、柔度和压弯构件正应力的要求;方案B只需对贝雷桁架立柱做抗剪强度验算即可,且贝雷桁架具有装配化的优点,可以快速安装,稳定性强,在实际工程中可以优先选用方案B:贝雷桁架立柱式门洞支架。

某超深雨水泵站结构方案比选

杏花路下穿通道雨水泵站项目位于武汉市新洲区,泵站深度较深,为选取合适的建造方案,在设计前期针对雨水泵站常见的两种施工工艺——明挖现浇法和沉井法,做了详细的方案设计,并在施工难度、施工工期、对周边环境的影响和工程造价等方面进行了对比分析。结果显示:沉井法比明挖现浇法的优势在于综合造价低、风险小,但工期较长,在工期不是控制因素的前提下可以优先采用;在软土地区施工沉井时,需要在设计阶段充分考虑沉井下沉过程中可能出现的各种问题,采取充分的措施降低风险,确保沉井顺利实施。

Preparation and properties of open-cell zinc foams as human bone substitute material

Foamed zinc was prepared by infiltration casting process.The mechanical properties and corrosion resistance of the samples were studied,and the feasibility of the foamed zinc as a bone implant material was discussed.All the compression stress-strain curves of open-cell zinc foams with various cell size(1-4 mm)and porosity(55%-67%)show three stages:elastic stage,plastic stage,and densification stage.The compression strength increases with decreasing density.The smooth stress-strain response indicates a progressively deformation of open-cell zinc foam.In addition,the cell wall or edge bending and fracture are the dominated mechanisms for failure of open cell zinc foam.The immersion test for determining the corrosion rate of open cell zinc foam was conducted in simulated body fluid.It was found that zinc foam with a small cell size and high porosity showed a higher corrosion rate.In addition,open-cell zinc foams can effectively induce Ca-P deposition in immersion tests,showing good bioactivity.Therefore,the open cell zinc foam prepared in this experiment has a good potential application as a human bone substitute material.

基于UG/Open GRIP二次开发的压铸模的标准设计法

运用UG/Open GRIP二次开发技术,通过UG软件操作,实现了压铸模的全参数化设计及调用.研究了UG/Open GRIP编程语言的特点,实现了人机交互式的工程零部件的输入与输出.该系统可以建立标准化数据库,从而提高了压铸模的设计效率.

改性前驱体调控泡沫铝孔结构尺寸的研究

为了达到较好的调节熔模铸造法制备的泡沫铝孔棱尺寸的效果,对聚氨酯泡沫母体材料孔棱进行了详细的粗化修饰实验。对母体材料经过预处理后,按照一定比例稀释后的乙醇清漆对孔棱尺寸为0.3 mm的聚氨酯泡沫进行粗化;通过实验发现清漆稀料配比为3.5∶1的稀释液可以获得较好的粗化效果,经过8次粗化后孔棱尺寸可以达到0.8 mm左右。提出了一种数学模型,可以较准确地对聚氨酯泡沫母体材料粗化效果进行理论计算和预测;同时,对粗化过程中乙醇清漆粘附母体材料孔棱的过程中的机理进行了讨论分析。在清理制备的泡沫铝中石膏型过程中,使用8 wt%的醋酸铵溶液可以达到较好的处理效果。

基于HHO-LSSVM的露天煤矿抛掷爆破效果预测研究

为提高露天矿抛掷爆破效果预测精度,进而反馈优化爆破参数设计。建立HHO-LSSVM(哈里斯鹰算法优化最小二乘支持向量机)模型,预测抛掷爆破效果;将该模型所得预测精度及效率与未经优化的LSSVM(最小二乘支持向量机)、ELM(极限学习机)、GA-BP(遗传算法优化BP神经网络)、PSO-LSSVM(粒子群算法优化最小二乘支持向量机)模型进行对比。研究结果表明:采用HHO-LSSVM模型相较于未经优化的LSSVM和ELM模型所得到的有效抛掷率、松散系数、最远抛掷距离的预测精度均具有更高的决定系数值,更小的均方根误差值;HHO-LSSVM模型预测的有效抛掷率、松散系数、最远抛掷距离与实测数据之间的平均误差分别为2.7015%,2.9834%,2.8345%,均在5%以内,说明HHO-LSSVM模型对抛掷爆破效果具有较好的预测精度。研究结果可为通过准确预测爆破效果进而反馈抛掷爆破的优化设计提供一定参考。

基于案例的灌注桩后注浆影响因素分析与讨论

通过工程实例,与现行的规范做法进行对比和分析,探究灌注桩后注浆施工中导管的安置方式、开塞注浆时间、后注浆阀的构造方式这三项施工工艺对后注浆施工的影响,以期得到更优的后注浆施工方案。结果表明:新型后注浆阀效果好、成本低、制作方便;后注浆管的不同的落管方式,对开塞注浆时间的要求不同,后注浆管随钢筋笼下落需按规范在开孔两天内开塞,自由落管则可以适当延长开塞时间,并且自由落管相对于随钢筋笼下落,开塞成功率更高。

低黏度直投式断级配超薄罩面试验与应用

超薄罩面对沥青混合料要求较高,要兼顾力学性能、路面功能,还要考虑施工性能,因此无论对矿料还是胶结料及矿料级配都提出更高要求。半开级配能够为超薄罩面提供更优良的抗滑性能和降噪效果,同时为黏层油乳化沥青容留空间,避免泛油。在借鉴现有级配设计理论基础上,计算出3条超薄罩面沥青混合料级配曲线。对不同级配沥青混合料进行体积指标测试,确定空隙率在10%左右的半开级配具有良好的路用性能和路表功能。为避免胶结料黏度过大造成施工困难,采用低黏度直投式高弹添加剂对沥青混合料进行改性,在提升沥青混合料性能的同时,大幅降低混合料生产施工难度。

圆坯连铸机自动浇注故障及其解决方案

圆坯连铸机液面控制系统,能实现结晶器钢水液面自动浇注,减少浇钢工的劳动强度,实现钢水液面平稳运行,杜绝因钢水结壳造成拉漏事故发生,能改善铸坯表面质量,确保产品质量达到预定要求;相对于手动浇注时,由于液面波动大,夹渣、卷渣、拉速变化快而引起冷却不均匀,影响了铸坯的表面质量及铸坯产生内部缺陷。钢水液面自动控制系统的优点是液面稳定,拉速波动小,克服了手动浇注的缺点,从而提高了铸坯质量。

上跨高速公路现浇箱梁交通疏解要点

随着“交通强国”战略的实施,我国基础设施建设突飞猛进,尤其是高速公路的建设得到了飞速的发展。随之而来的问题是新建高速公路由于线型控制需要,往往会涉及到上跨高速公路施工。上跨高速公路施工方法主要有门洞支架法、挂篮施工、转体施工等,挂篮施工和转体施工对既有高速公路通行影响较小,但门洞支架法施工对既有高速公路影响较大,本研究主要探讨门洞支架法施工时,对既有高速公路交通疏解相关问题。