Accounting for the uncertainties in the estimation of average shear wave velocity using V S– N correlations

Site-specific seismic hazard analysis is crucial for designing earthquake resistance structures, particularly in seismically active regions. Shear wave velocity ( V _S) is a key parameter in such analysis, although the economy and other factors restrict its direct field measurement in many cases. Various V _S–SPT– N correlations are routinely incorporated in seismic hazard analysis to estimate the value of V _S. However, many uncertainties question the reliability of these estimated V _S values. This paper comes up with a statistical approach to take care of such uncertainties involved in V _S calculations. The measured SPT– N values from all the critical boreholes were converted into statistical parameters and passed through various correlations to estimate V _S at different depths. The effect of different soil layers in the boreholes on the Vs estimation was also taken into account. Further, the average shear wave velocity of the top 30 m soil cover ( V _S30) is estimated after accounting for various epistemic and aleatoric uncertainties. The scattering nature of the V _S values estimated using different V _S– N correlations was reduced significantly with the application of the methodology. Study results further clearly demonstrated the potential of the approach to eliminate various uncertainties involved in the estimation of V _S30 using general and soil-specific correlations.     

Separation of hematite from banded hematite jasper (BHJ) by magnetic coating

The separation of iron oxide from banded hematite jasper(BHJ) assaying 47.8% Fe, 25.6% Si O2 and 2.30%Al2O3 using selective magnetic coating was studied. Characterization studies of the low grade ore indicate that besides hematite and goethite,jasper, a microcrystalline form of quartzite, is the major impurity associated with this ore. Beneficiation by conventional magnetic separation technique could yield a magnetic concentrate containing 60.8% Fe with 51% Fe recovery. In order to enhance the recovery of the iron oxide minerals, fine magnetite, colloidal magnetite and oleate colloidal magnetite were used as the coating material. When subjected to magnetic separation, the coated ore produces an iron concentrate containing 60.2% Fe with an enhanced recovery of56%. The AFM studies indicate that the coagulation of hematite particles with the oleate colloidal magnetite facilitates the higher recovery of iron particles from the low grade BHJ iron ore under appropriate conditions.     

硫酸厂主鼓风机的主要设计准则

论述现代硫酸厂主鼓风机设计时必须考虑的关键因素，通过实例讨论操作费用与投资之间的平衡关系以及对装置竞争力的影响。建议在硫酸厂严酷的操作条件下改进风机特性，提高耐磨性并采用维修友好的设计。     

澳大利亚蒂汶海奥利弗气田古油藏潜力定量评价

砂岩岩心和钻屑中的含油流体包裹体代表了隐蔽的石油显示。含有此类包裹体的石英颗粒的数目(GOI数)反映了砂岩储层中曾经历过最大的古含油饱和度，而与现今流体相无关。含油饱和度高的样品比含油饱和度低的样品的GOI数至少高一个数量级。因此，在原始油被后期填充气取代的井中，可根据这些流体包裹体的资料确定古油柱并划分原始油一水界面。此外，若能利用详细的GOI图精确确定原始油一水界面的位置，那么就可以确定古油柱的高度并估算原始石油地质储量。奥利弗(Oliver)油气田位于澳大利亚蒂汶海(Timor)，现在含有一个178．5m的油气柱，其中气柱高164m，位于14．5m油柱之上。该油气田已填充至溢出点。奥利弗-1井的GOI图显示，在现在的气柱内古油柱的总高度曾在99-132m之间，原始石油地质储量高达2亿bbl，明显高于现在4500万bbl的储量。高达1．55亿bbl的油从奥利弗构造转移到其上倾方向的倾斜断块，从而大大改善了该断块构造的勘探远景。GOI制图法是一种储层描述新方法。它能可靠探测现在被气充填的圈闭中的古油储。在新井钻探之前，利用这些资料可以定量描述气藏及其附近未测试构造的油藏潜力。     

气垫式调压室及其在压缩空气能量蓄存方面的应用

挪威独有的高压气垫式调压室是坚硬岩石洞室中压缩空气能量蓄存的极好的先例，在供电不能满足峰荷需求的电站，这一技术正引起极大的关注。从气垫空气损失获得的经验表明，在大多数情况下不衬砌洞室都适用于压缩空气的密闭，只有少数情况时需采取修补措施以减少空气损失。业已证明，水幕是控制空气损失的最有效的方法。     

用于单芯片系统的改进型WXGA LCoS成像器

本文讨论用于单芯片时序混色的菲利浦DD-720硅基液晶(LCoS)片。这种芯片主要用于HDTV背投影机和多媒体系统。与菲利浦以前的单片LCoS设计相比，由于该芯片具有电接口接点较少、封装简单和温度传感器内置等许多特点，使其应用于投影系统时成本降低。     

停运44年后混流式水轮机复活了

最初于二十世纪二十年代投入运行的澳大利亚艾尔登(Eildon)水电站两台7．5MW混流式水轮机已经重新投入运行了。对机组恢复使用并在原来两倍的水头下运行的可行性进行了调查，发现这两台机组能够重新投运，并且可在更高压力下运行。本文介绍了这个非常规项目的机械试验、有限元分析和其它试验，这个项目后来在澳大利亚和新西兰获得了三项优秀工程奖。     

加拿大稠油、超稠油开采技术及发展趋势

在2005年SPE的拉丁美洲和加勒比海石油工程会议上．阿尔伯塔大学的科研人员介绍了加拿大稠油、超稠油资源的开发情况，以及开发适用技术和面临的挑战，其提供的信息对世界其他地区的稠油资源的开发也会起到一定的借鉴作用。[编者按]     

BaxSr（1—x）TiO3多层膜椭偏光谱研究

用溶胶－凝胶技术在Bi(100）衬底上制备了单层和渐变型多层的BaxSr(1-X)TiO3薄膜，其膜层组分分别为：Ba0.7Sr0.3TiO3,Ba0.8Sr0.2TiO,Ba0.9Sr0.1TiO3,BaTiO3，对生长制备出的多层BaxSr(1-X)TiO3薄膜进行了变角度椭偏光谱测量，通过椭偏光谱解谱分析研究，首次得到了BaxSr(1-X)TiO3多层膜结构不同膜层的膜厚和光学常数，其结果显示：椭偏光谱分析得到的不同膜层的膜厚与卢瑟福背向散射测量得到的结果基本相符；渐变型多层膜中BaTiO3薄膜的折射率比单层BaTiO3薄膜折射率大许多，与体BaTiO3的折射率相接近，这说明渐变型多层膜中BaTiO3薄膜的光学性质与体材料的光学性质接近。     

洁净钢生产实践

本文评述了在钢包、中间包和连铸机上提高钢水洁净度的操作，旨在提供生产洁净钢的有用信息，关注氧化铝夹杂物的控制。