Detection of creep degradation during pressure vessel testing using electromagnetic sensor technology

9%Cr steels have been in use in power generation for over 20 years. Over this time, there have been a number of incidents of failure by Type IV cracking at welds initiating sub-surface, making surface inspection procedures unsuitable for crack detection. Replication to identify creep cavitation damage can potentially give an early warning of imminent cracking, but has proved unsuccessful in high Cr martensitic steels. Electromagnetic (EM) inspection can provide fast inspection of welded components with minimal surface preparation and some increase in inspection depth. This paper shows the results of accelerated creep tests carried out on a P91 pressure vessel, with EM inspections during regular test interruptions. The results show that EM inspection gave indications of damage in the latter stages of creep cavitation. EM is considered to have the potential for quick assessment of component through thickness damage, flagging up locations of potential problems for more detailed investigation.     

舰艇管道支吊架结构及特性综述

舰艇内部错综复杂的管道系统为各舱室及各种设备传递水、油、气等介质,是舰艇抗冲击性能的"短板"。舰艇管道的支吊架不仅需要支撑管道及内部流体的重量,还必须具备一定的隔离冲击的能力。支吊架的选型和设计是管路系统设计的重点和难点之一,选择支吊架的类型需要考虑管道的空间结构、与舱壁的距离、连接设备的安装方式以及管路的冲击隔离需求,此外还需要熟悉各类支吊架的结构和抗冲击特性。首先根据支吊架的抗冲击特性将其分为:刚性支吊架、普通弹性支吊架、恒力弹性支吊架、油阻尼弹簧支吊架、三向抗冲击支吊架,然后对各种支吊架的结构和抗冲击特性进行较为详细的介绍。熟悉支吊架结构和抗冲击特性,有助于正确选用支吊架的类型并合理设计支吊架的结构,从而提高舰艇管道系统的抗冲击能力。     

Effects of electropulsing on inclusion size and corrosion-resistance of 304 stainless steel

Electropulsing has been imposed on molten AISI 304 stainless steel and its effects on the inclusion size and corrosion properties have been investigated. The average size of inclusions in electropulsing-treated samples was finer than that in untreated ones. A theoretical analysis shows that the mobility of solute atoms increases with electropulsing treatment. This promotes the nucleation of inclusions. Owing to a smaller inclusion size, the electrochemical experiments reveal that the pitting corrosion resistance of the electropulsing-treated stainless steel is significantly improved. The beneficial effects of electropulsing on the refinement of inclusions and the resistance to pitting corrosion increase with an increase in current density. Electropulsing treatment, therefore, provides a promising means to improve pitting corrosion resistance.     

Lupin seed γ-conglutin: Extraction and purification methods - A review

BackgroundLupin, the largest legume crop in Australia, is gaining global attention because of its unique protein γ-conglutin, which has shown promise as a nutraceutical for controlling blood glucose level and thus reducing the risk of type II diabetes development. Type II diabetes is a chronic condition affecting millions of individuals worldwide, which urgently requires natural side effect free therapies as alternatives to currently used drugs. Purification of γ-conglutin opens up a new avenue for high-value products from lupin seeds as nutraceuticals, the market for which is predicted to reach US$ 250 billion by 2018 (Dutta, Mahabir, & Pathak, 2013).Scope and approachPreviously, several research groups have reported trials on extracting and purifying proteins from lupin seed. However, most of these methods have focussed on protein isolates as food ingredients. Very few reports have aimed to purify γ-conglutin from the total proteins, but the methods reported are time-consuming and unsuitable for commercial scale production of high purity γ-conglutin due to the involvement of many processing steps for nutraceutical application. Hence there is a need to fully understand all reported γ-conglutin extraction and purification processes in terms of their advantages and limitations, so that an effective scalable purification process for nutraceutical grade γ-conglutin may be designed in the future.Key findings and conclusionsThis article reviews reported extraction and purification methods for γ-conglutin, to provide a basis for the development of novel purification technique/process for this potentially highly valuable protein.     

Relationship of multidrug-resistant gene and extended-spectrum carbapenem-resistance in <i>Staphylococcus aureus</i>

The aim of this study was to determine the relationship between phenotypic antimicrobial susceptibility patterns and extended-spectrum, carbapenem-resistance genes. A total of 109 clinical Staphilococcus aureus strains were subjected to 19 antimicrobial susceptibility tests. Resistance to methicillin (mecA), penicillin (blaTEM), and tetracycline (tetM) was detected. We compared the presence of the blaTEM genes with extended-spectrum, carbapenem-related genes and identified the types of SCCmec genes. Of 109 clinical S. aureus strains, 62 (56.88%) had methicillin resistance and 60 strains carried mecA. The prevalence of blaTEM and tetM genes was 81.65% and 37.61%, respectively. The most predominant SCCmec type was SCCmec type II 28/60 (46.67%), in 60 mecA-positive methicillin-resistant S. aureus (MRSA) isolates. The SCCmec prevalence rates were type IVA 30.00% (18/60), type IVb 8.33% (5/60), type IVd 6.67% (4/60), and non-typable 8.33% (5/60). Sixty of the 109 (55.05%) MRSA isolates were positive for extended-spectrum carbapenems (31/60) (51.67%), cephalosporins 40/60 (66.67%) and carbapenems 31/60 (51.67%). The predominant SCCmec type II demonstrated more carbapenem-resistance than the IVA, IVb and IVd types.     

Characteristic of local boiling heat transfer of ammonia and ammonia / water binary mixture on the plate type evaporator

Power generation using small temperature difference such as ocean thermal energy conversion (OTEC) and discharged thermal energy conversion (DTEC) is expected to be the countermeasures against global warming problem. As ammonia and ammonia/water are used in evaporators for OTEC and DTEC as working fluids, the research of their local boiling heat transfer is important for improvement of the power generation efficiency. Measurements of local boiling heat transfer coefficients were performed for ammonia /water mixture (z = 0.9−1) on a vertical flat plate heat exchanger in a range of mass flux (7.5–15 kg/m² s), heat flux (15–23 kW/m²), and pressure (0.7–0.9 MPa). The result shows that in the case of ammonia /water mixture, the local heat transfer coefficients increase with an increase of mass flux and composition of ammonia, and decrease with an increase of heat flux.     

2型糖尿病外科治疗机制研究进展

2型糖尿病发病率呈逐年上升的趋势。目前较为成熟的治疗方式仍为口服降糖药物,但降糖药物并不能阻止其并发症的发生。研究证明外科手术对2型糖尿病患者具有治疗作用且已经进入了临床。外科手术为2型糖尿病的治疗开创了新的途径,但其治疗机制尚不清楚。本文主要对2型糖尿病的外科手术治疗的机制作一综述。     

六味地黄丸对2型糖尿病患者血管内皮功能的影响

目的: 探讨六味地黄丸对2型糖尿病患者血管内皮功能的影响。方法: 选择10例正常健康体检者和60例2型糖尿病患者,糖尿病者随机分为2组,对照组给予常规治疗,治疗组在常规西药治疗基础上加用六味地黄丸,疗程为12周,分别测定治疗前后血清一氧化氮(NO)和内皮收缩因子内皮素(ET-1)、超氧化物歧化酶(SOD)及谷胱甘肽过氧化物酶(GSH-Px)水平,同时行肱动脉介导内皮依赖性舒张功能的超声检测(FMD)。结果: 对照组与治疗组较正常体检组血清NO、SOD、GSH-Px以及FMD水平降低,血清ET-1水平升高(P<0.01),两组较治疗前比较,治疗后血清NO、ET-1、SOD、GSH-Px水平较治疗前改善(P<0.05),FMD值增高,此外,六味地黄丸组较对照组治疗后改善更明显,除FMD外差异有统计学意义(P<0.05)。结论: 在西药基础治疗上,六味地黄丸治疗能改善2型糖尿病患者血管内皮功能。     

β3肾上腺素受体基因Trp64Arg多态性与中国男性2型糖尿病患者合并高尿酸血症的相关性研究

目的: 探讨中国人群男性2型糖尿病患者中β3肾上腺素受体基因Trp64Arg多态性与高尿酸血症的相关性。方法: 196名高尿酸血症的2型糖尿病患者和196名正常尿酸水平的2型糖尿病患者进行基因分型。检测体重指数、腰臀比、收缩压、舒张压、血尿酸、肌酐、尿素氮、甘油三酯、低密度脂蛋白胆固醇脂、高密度脂蛋白胆固醇脂、空腹血糖和餐后血糖的水平。结果: 高尿酸血症组中,携带不同β3肾上腺素受体Trp64Arg基因型的2型糖尿病患者其尿酸水平有统计学差异,且呈基因剂量效应[CC组(599.53±113.70) vs CT组(529.78±81.10) vs TT组(507.33±74.27), P<0.01]。在该研究中,Trp64Arg TC+CC基因型患者的血尿酸水平亦显著高于TT基因型组[(557.95±99.91) vs (503.47±69.40) μmol/L, P<0.01]。结论: β3肾上腺素受体基因Trp64Arg多态性与2型糖尿病合并高尿酸血症的具有相关性。     

吡格列酮联用阿托伐他汀对2型糖尿病患者血脂及血管内皮功能的影响

目的: 观察吡格列酮联用阿托伐他汀对2型糖尿病患者血脂及血管内皮功能的影响。方法: 选择2型糖尿病患者65例,随机分为对照组30例(A组),接受常规降糖药治疗和阿托伐他汀 10 mg/d;实验组35例(B组),在对照组基础上加用吡格列酮 15 mg/d,两组患者分别于治疗前、用药12周后检测血糖、糖化血红蛋白、血脂、血浆一氧化氮(NO)、内皮素-1(ET-1)的浓度、肱动脉内径变化率(FMD)。结果: 治疗后两组患者的血糖水平均较治疗前明显降低,与治疗前比较差异有统计学意义(P<0.01),但两组间比较差异无统计学意义(P>0.05)。两组患者ET-1水平有所降低(P<0.05),血浆NO水平和FMD均明显升高,与治疗前比较差异均有统计学意义(P<0.01);B组NO的升高水平和FMD较A组明显,两组比较差异均有统计学意义(P<0.05)。治疗后两组患者体重指数均有所改善(P<0.05,P<0.01)。结论: 吡格列酮联用阿托伐他汀能够更有效降低患者血脂水平,改善2型糖尿病患者血管内皮功能。