Numerical simulation and seismic performance evaluation of buried pipelines rehabilitated with cured‐in‐place‐pipe liner under seismic wave propagation

The cured‐in‐place‐pipe (CIPP) liner technology involves installation of flexible polymeric composite liners coated with thermosetting resin to the inner surfaces of existing buried pipelines. This innovative technology provides an efficient, economic, and environmentally friendly alternative for rehabilitation of structurally compromised underground pipelines without expensive and disruptive excavation. However, the lack of analytical/numerical procedures to quantify the seismic performance of CIPP liner reinforced pipelines remains a barrier to the seismic design and rehabilitation of underground pipelines. This paper first develops an experimentally validated hysteretic model of ductile iron push‐on joints, reinforced with one particular type of CIPP liner under repeated axial loading. A numerical procedure is then proposed to systematically assess the seismic performance and fragility of straight buried pipelines incorporating push‐on joints and subjected to transient ground deformations. The numerical results indicate that CIPP liner‐reinforced pipelines exhibit favorable robust seismic performance with limited joint damage under high‐intensity transient ground deformations. Copyright © 2016 John Wiley & Sons, Ltd.     

鲜水河断裂带色拉哈—康定段新发现的活动断层：木格措南断裂

鲜水河断裂带位于青藏高原东缘,是中国大陆内部地震活动性最强的大型活动断裂带之一。大量研究证据表明,鲜水河断裂带色拉哈—康定段未来几十年内发生破坏性强震的风险较高。目前正在规划建设的国家重大交通基础建设工程——川藏铁路,将在康定折多山地区直接穿越鲜水河活动断裂带。本研究通过高分辨率卫星影像的地质地貌解译和详细的野外构造地质填图,新发现一条发育于色拉哈断裂和折多塘断裂之间折多山花岗岩体内的长约24km的全新世活动断层,该断裂空间上可分成北、中、南三段,呈(正滑)左旋右阶雁行状排列,并将其命名为“木格措南断裂”。该活动断裂的发现对完善鲜水河断裂带色拉哈—康定段的精细几何图像和构造组合特征,准确评价鲜水河断裂带的地震危险性具有重要意义,并为川藏铁路施工建设和安全运营提供了重要科学数据支撑。     

Identification of low frequency waves in the vicinity of the terrestrial bow shock

In this paper, methods for the determination of the wave mode for low frequency waves based on observed differences in phase are reviewed. Examples, using measurements made in the terrestrial foreshock and magnetosheath, are used to illustrate the application of these methods. The use of advance methods such as NARMAX modelling or genetic algorithms to identify the plasma wave mode is also discussed.     

The Nu Expression for Probabilistic Data Integration

The general problem of data integration is expressed as that of combining probability distributions conditioned to each individual datum or data event into a posterior probability for the unknown conditioned jointly to all data. Any such combination of information requires taking into account data interaction for the specific event being assessed. The nu expression provides an exact analytical representation of such a combination. This representation allows a clear and useful separation of the two components of any data integration algorithm: individual data information content and data interaction, the latter being different from data dependence. Any estimation workflow that fails to address data interaction is not only suboptimal, but may result in severe bias. The nu expression reduces the possibly very complex joint data interaction to a single multiplicative correction parameter ν ₀, difficult to evaluate but whose exact analytical expression is given; availability of such an expression provides avenues for its determination or approximation. The case ν ₀=1 is more comprehensive than data conditional independence; it delivers a preliminary robust approximation in presence of actual data interaction. An experiment where the exact results are known allows the results of the ν ₀=1 approximation to be checked against the traditional estimators based on assumption of data independence.     

In-flight Performance of the Advanced Camera for Surveys CCDs

The Advanced Camera for Surveys (ACS), installed in the Hubble Space telescope in March 2002, will significantly extend HST's deep, survey imaging capabilities. ACS has met, or exceeded, all of its key performance specifications. In this paper we briefly review the in-flight performance of the instrument's CCD detectors and preview early ACS science observations. This revised version was published online in July 2006 with corrections to the Cover Date.     

Fluid geochemistry of natural manifestations from the Southern Poroto–Rungwe hydrothermal system (Tanzania): Preliminary conceptual model

The South Poroto–Rungwe geothermal field, in the northern part of the Malawi rift, Tanzania divides in two main areas. The relatively high altitude northern area around the main Ngozi, Rungwe, Tukuyu and Kyejo volcanoes, is characterised by cold and gas-rich springs. In contrast, hot springs occur in the southern and low-altitude area between the Kyela and Livingstone faults. The isotopic signature of the almost stagnant, cold springs of the Northern district is clearly influenced by H₂O–CO_2(g) exchange as evidenced from negative oxygen-shifts in the order of few deltas permil. In contrast, the isotopic signature of waters discharged from the hot springs of the Southern district is markedly less affected by the H₂O–CO_2(g) interaction. This evidence is interpreted as an effect of the large, permanent outflow of these springs, which supports the hypothesis of a regional-scale recharge of the major thermal springs. Measurements of carbon isotope variations of the dissolved inorganic carbon of waters and CO_2(g) from the Northern and Southern springs support a model of CO_2(g)-driven reactivity all over the investigated area. Our combined chemical and isotopic results show that the composition of hot springs is consistent with a mixing between (i) cold surface fresh (SFW) and (ii) Deep Hot Mineralised (DHMW) Water, indicating that the deep-originated fluids also supply most of the aqueous species dissolved in the surface waters used as local potable water. Based on geothermometric approaches, the temperature of the deep hydrothermal system has been estimated to be higher than 110 °C up to 185 °C, in agreement with the geological and thermal setting of the Malawi rift basin. Geochemical data point to (i) a major upflow zone of geothermal fluids mixed with shallow meteoric waters in the Southern part of the province, and (ii) gas absorption phenomena in the small, perched aquifers of the Northern volcanic highlands.     

The sources of geogenic arsenic in aquifers at Datong basin,northern China: Constraints from isotopic and geochemical data

Mineralogical, geochemical and zircon U–Pb dating studies were carried out to identify the sources of arsenic in the shallow aquifers of Datong Basin in northern China. A sediment sample from 18 m depth containing 10.3 mg/kg arsenic showed a Zircon U–Pb concordant age of 2528 ± 20 to 271 ± 4 Ma that can be divided into two groups (2528 ± 20 to 1628 ± 21 Ma and 327 ± 4 to 271 ± 4 Ma) and is comparable to that of the sedimentary rocks of Taiyuan (upper Carboniferous) and Shanxi Formation (lower Permian) outcropping to the west of Datong Basin. In contrast, a sediment sample from 22.5 m depth containing 5.7 mg/kg arsenic displayed a Zircon U–Pb concordant age ranging from 2561 ± 21 to 1824 ± 26 Ma that is comparable to that of the Hengshan Complex (Ne-Archaean Precambrian) outcropping to the east of .     

Spatial distribution and general population characteristics of mysid shrimps in the Westerschelde estuary (SW Netherlands)

The distribution and general population characteristics of five mysid shrimps were investigated in the period 2003–2005 in the Westerschelde estuary, a tidal temperate estuary situated along the Dutch–Belgian border. Multivariate analyses revealed that salinity predominantly governs the spatial distribution of Neomysis integer, Gastrosaccus spinifer, Schistomysis kervillei and Schistomysis spiritus while temperature, and to a lesser extent turbidity, control the distribution of Mesopodopsis slabberi. N. integer is a resident species in the mesohaline zone of the estuary, i.e. all life stages of the species are present in the estuary throughout the year. For the first time since decades N. integer inhabits the oligohaline zone of the estuary supposedly as a consequence of improved oxygen conditions in the upstream reaches. M. slabberi, the most abundant mysid in the Westerschelde, dominates the hyperbenthos of the mesohaline zone of the estuary. The polyhaline zone of the estuary is, most abundantly inhabited by M. slabberi, G. spinifer, S. kervillei and to a lesser extent by S. spiritus. The abundance of the latter four species is low in winter, probably due to a migration towards coastal waters to avoid colder temperatures in the estuary combined with an increased mortality after breeding. The sex ratio of all the mysid populations corresponds to the expected 1:1 female:male ratio and no salinity governed segregation is found between the different life stages of each mysid population. A seasonal variation exists in brood size in the N. integer population regardless of the body size, with a larger number of broods during winter and spring compared to the summer. In the other mysid populations the brood sizes vary only with the length of the ovigerous females.     

Correction to: Evaluation of a multi-model approach to estimate leaf wetness duration: an essential input for disease alert systems

Theoretical and Applied Climatology -