Structural integrity analysis of axially cracked pipelines using conventional and constraint-modified failure assessment diagrams

This study explores applications of the failure assessment diagram (FAD) methodology to predict the failure behaviour for high pressure pipelines with planar defects having different geometries (i.e., crack depth and crack length). One purpose of this investigation is to assess the capability of FAD procedures in integrity analyses of high pressure pipelines with varying crack configurations. Another purpose is to address the effectiveness of constraint-based FADs to predict burst pressure of low-constraint cracked pipelines. Full scale burst testing of end-capped pipe specimens with axial surface flaws provide the data needed to compare the failure predictions derived from the FAD procedures. The analyses reveal that the degree of agreement between predicted pressures and experimentally measured values depends rather markedly on the crack size for the tested pipes. Moreover, the analyses also show a possible weak dependence of the predicted pressures on the constraint-based correction scheme. Overall, the results validate the use of FAD-based methodologies for defect assessments of axially cracked pipelines.     

Organic solvent pretreatment to enhance enzymic saccharification of straw

Enzymic saccharification of wheat straw in the absence of any pretreatment was only about 20 %. Acid hydrolysis did not improve the overall cellulose enzymic breakdown, nor did pretreatment by flash autohydrolysis under pressure or sodium chlorite delignification. When wheat straw was treated with N-methyl-morpholine-N-oxide (MMNO) at J20°C for 20–30 min, this treatment and subsequent enzymic hydrolysis produced carbohydrate conversion of 73%. Similar results could be obtained by treating straw with 0·1 M sodium hydroxide. When MMNO treatment was combined with any other pretreatment, the saccharification yield was greatly enhanced. Nearly quantitative conversion was obtained by swelling straw in 0·1 M sodium hydroxide followed by MMNO treatment. The results show that lignin content of plant material does not represent the limiting factor to enzymic saccharification.     

数据库存储过程设计及应用

以ORACLE数据库为例，介绍了数据库存储过程及外部存储过程的设计方法，并结合ORACLE数据库应用开发、管理与维护的需要，说明存储过程及外部存储过程的具体应用。最后，对数据库应用开发中设计并使用存储过程和外部存储过程的主要优点进行了总结。     

低温钢A333 Gr.6的焊接

以3×104t/a聚丙烯装置低温管线的焊接为例,分析了低温钢A333 Gr.6的焊接性,并介绍焊接材料的选用以及焊接注意事项,制定焊接工艺并进行实施。     

堆焊敷层技术在立柱中缸上的应用

介绍利用堆焊熔敷技术生产制造立柱中缸。针对立柱中缸的结构特点,提出堆焊具体方法、方案,并从理论上分析了27SiMn管堆焊技术应用的可行性,结合生产实际过程,就焊材、焊接工艺、焊后热处理等几个方面提出一些建议,同时对应用前景进行了展望。     

某铁矿露天开采程序所究

某铁矿露天采场的上下部剥采比相差悬殊，３个主矿体矿量分布很不均衡。设计中通过开采程序研究，选择了适合该矿特点的开采程序方案。文中着重论述了储量最大、开采条件最复杂的西矿体５个开采程序方案的比较与确定。     

回采速度对地表动态移动变形值的影响

以Knothe模型的函数为基础，对不同推进速度下动态地表移动和变形进行了研究，结果证明，提高开采速度有利于减小地表采动损害。     

新型复配混凝剂处理三次采油废水的实验研究

从已有的混凝剂中筛选出几种适合处理三次采油废水的无机和有机高分子混凝剂,通过复配提高三次采油废水中部分水解聚丙烯酰胺(HPAM)的去除率,由实验得出了最佳复配pH,在最佳pH和最佳搅拌条件下进行实验,发现聚合双酸铝铁(PAFCS)和阳离子型聚丙烯酰胺[P(DMDAAC/AM)]复配能得到最好的效果,HPAM的去除率达到92.6%.另外,在实验中通过添加氧化剂进行了氧化预处理实验,并进行了加砂强化混凝实验.     

提高人工湿地脱氮除磷性能的强化技术及其在有色金属工业废水中的应用

人工湿地因具有良好的脱氮除磷性能而广泛应用于生活污水尾水和工业废水的深度处理。然而,随着环保政策要求的日益严格,传统的人工湿地对不同水质污水的处理能力有限,从而导致多数污水处理难以满足达标排放的要求。因此,越来越多的强化技术与手段被应用于人工湿地系统,以增强人工湿地的污染物净化性能。主要从合理设计人工湿地、联合预处理工艺构建复合人工湿地系统以及保温和溶解氧控制等方面综述当前提高人工湿地脱氮除磷性能的强化技术,并简要概述了人工湿地在处理有色金属工业废水中的应用。     

MSC Pretreatment for Improved Transplantation Viability Results in Improved Ventricular Function in Infarcted Hearts

Many clinical studies utilizing MSCs (mesenchymal stem cells, mesenchymal stromal cells, or multipotential stromal cells) are underway in multiple clinical settings; however, the ideal approach to prepare these cells in vitro and to deliver them to injury sites in vivo with maximal effectiveness remains a challenge. Here, pretreating MSCs with agents that block the apoptotic pathways were compared with untreated MSCs. The treatment effects were evaluated in the myocardial infarct setting following direct injection, and physiological parameters were examined at 4 weeks post-infarct in a rat permanent ligation model. The prosurvival treated MSCs were detected in the hearts in greater abundance at 1 week and 4 weeks than the untreated MSCs. The untreated MSCs improved ejection fraction in infarcted hearts from 61% to 77% and the prosurvival treated MSCs further improved ejection fraction to 83% of normal. The untreated MSCs improved fractional shortening in the infarcted heart from 52% to 68%, and the prosurvival treated MSCs further improved fractional shortening to 77% of normal. Further improvements in survival of the MSC dose seems possible. Thus, pretreating MSCs for improved in vivo survival has implications for MSC-based cardiac therapies and in other indications where improved cell survival may improve effectiveness.