Long-term monitoring of wall paintings affected by soluble salts

Long-term monitoring of wall paintings in historical monuments aims at clarifying involved decay processes and at the same time controlling effects of interventions for conservation. Monitored decay processes relate to the crystallisation of various salts – particularly of nitronatrite and gypsum – from hygroscopic solutions accumulated in the zone of ground moisture. The salts crystallise in response to climatic variations and other environmental changes. Measures for conservation such as protection from water infiltration, reduction of heating temperature and reduction of surface salt accumulation cause a significant slow-down but not a stop of decay. The particular dynamics and causes of remaining slow decay processes are described on three sites in Switzerland: the convent church of Müstair, the crypt in the cathedral of Basel and the crypt in the Grossmünster church of Zürich.     

Mineralogy of suspended sediment in three karst springs

Springs in karstic carbonate rocks frequently carry a sediment load as well as a dissolved load. Analysis of morphology and mineralogy of suspended sediment from three contrasting karst springs reveals a suite of clastic particles that reflect both source areas and processes that take place within the aquifer. Nolte Spring in Lancaster County, Pennsylvania, USA, discharges sediment of apparently precipitated calcite, indicating that at some point in the aquifer or vadose zone, water exceeds saturation with respect to calcite. Sediment morphologies and chemical conditions in the aquifer point to two different scenarios for this precipitation. The other two springs, Arch Spring in Blair County, Pennsylvania and Bushkill Spring in Northampton County, Pennsylvania, show no evidence of calcite precipitation. Arch Spring discharges mainly layer silicates, while Bushkill Spring discharges mainly silica.

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Resumen Los manantiales en rocas carbonatadas karstficadas tienen frecuentemente una carga de sedimentos y de sólidos disueltos. Los análisis de la morfología y mineralogía de los sedimentos suspendidos de tres manantiales kársticos contrastados revela un conjunto de partículas clásticas que reflejan ambas áreas fuente y los procesos que tienen lugar dentro del acuífero. Nolte Spring en el Condado de Lancaster, Pennsylvania, USA, descarga sedimento de calcita aparentemente precipitada indicando que en cierto punto del acuífero o en la zona vadosa, el agua supera la saturación con respecto a la calcita. La morfología de los sedimentos y las condiciones químicas en el acuífero apuntan a dos escenarios diferentes para esta precipitación. Los otras dos manantiales, Arch Spring en el Condado de Blair, Pennsylvania y Bushkill Spring en el Condado de Norhtampton, Pennsylvania, no muestran evidencia de precitación de calcita. Arch Spring descarga principalmente filosilicatos mientras que Bushkill Spring descarga fundamentalmente Sílice.

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Résumé Les sources situées en contexte carbonaté karstique charrient fréquemment, outre les matières dissoutes, une charge solide. La morphologie et la minéralogie des sédiments en suspension issus de trois sources karstiques de caractéristiques distinctes ont été analysées : une série de particules clastiques, reflétant à la fois les secteurs des sources et les processus internes de l’aquifère, en ressort. Les sédiments issus de Nolte Spring (Comté de Lancaster, Pennsylvanie, Etats-Unis) sont constitués de calcite apparemment précipitée: ceci indique que l’eau atteint la sursaturation vis-à-vis de la calcite à un certain point de l’aquifère ou de la zone non-saturée. La morphologie des sédiments et les conditions chimiques au sein de l’aquifère mènent à deux scénarii différents pour expliquer cette précipitation. Les deux autres sources, Arch Spring (Comté de Blair, Pennsylvanie) et Bushkill Spring (Comté de Northampton, Pennsylvanie), ne présentent aucun indice de précipitation de calcite. Arch Spring exporte essentiellement des phyllosilicates, alors que la silice est majoritaire à Bushkill Spring.

     

The application of satellite differential SAR interferometry-derived ground displacements in hydrogeology

The application of satellite differential synthetic aperture radar (SAR) interferometry, principally coherent (InSAR) and to a lesser extent, persistent-scatterer (PSI) techniques to hydrogeologic studies has improved capabilities to map, monitor, analyze, and simulate groundwater flow, aquifer-system compaction and land subsidence. A number of investigations over the previous decade show how the spatially detailed images of ground displacements measured with InSAR have advanced hydrogeologic understanding, especially when a time series of images is used in conjunction with histories of changes in water levels and management practices. Important advances include: (1) identifying structural or lithostratigraphic boundaries (e.g. faults or transitional facies) of groundwater flow and deformation; (2) defining the material and hydraulic heterogeneity of deforming aquifer-systems; (3) estimating system properties (e.g. storage coefficients and hydraulic conductivities); and (4) constraining numerical models of groundwater flow, aquifer-system compaction, and land subsidence. As a component of an integrated approach to hydrogeologic monitoring and characterization of unconsolidated alluvial groundwater basins differential SAR interferometry contributes unique information that can facilitate improved management of groundwater resources. Future satellite SAR missions specifically designed for differential interferometry will enhance these contributions.     

Analytical solutions of the diffraction problem of a group of truncated vertical cylinders

An exact analytical method is described to solve the diffraction problem of a group of truncated vertical cylinders. In order to account for the interaction between the cylinders, Kagemoto and Yue's exact algebraic method is utilised. The isolated cylinder diffraction potential due to incident waves is obtained using Garret's solution and evanescent mode solutions are derived in a similar manner.Numerical results are presented for arrays of two and four cylinders. Comparisons between the results obtained from the method presented here and those obtained from numerical methods show excellent agreement.     

Characterization of the Karababa-C reservoir in the South Karaku oilfield, southeast Turkey

The South Karaku oil field is located in southeast Turkey, and produces, from the Late Cretaceous Mardin Group, carbonate reservoirs consisting of the Karababa, Derdere, Sabunsuyu and Areban Formations. The Karababa Formation is divided into three members, of which the productive Karababa-C member, discussed here, is composed of shallow marine bioclastic mudstone to wackestone. It is affected by early to late diagenetic processes that caused modification of the original pore system by cementation, dissolution and fracturing. Two petrophysical-petrologic facies can be discriminated by principal component analysis, and linear, multiple and stepwise multiple regression analysis of petrophysical data. These correspond to vuggy-moldic porosity and microporosity dominated reservoirs.     

地质炸弹测定地下河位置的研究

<正> 一般的地下河虽然往往有明显的入口和出口,但地下河道的位置却很难探明。目前广泛应用的各种地下水示踪方法都只能确定某入口与某出口之间的连通关系,不能查明地下河道的位置。因此长期以来曾有不少人提出各种查明地下河道的方案。如在地下河中投放磁性物质,然后用磁力仪来探测河道位置。也有人提出投放小型无线电发射机,然后用无线电定向接收装置来追踪河道位置。另一种方案是投放小型定时炸弹,在地面上用地震仪接收炸弹爆炸所产生的地震波,根据地震波的到达时间来计算地下河的位置。后两种方案曾被列入全国的岩溶科研规划中。 <正> 一般的地下河虽然往往有明显的入口和出口,但地下河道的位置却很难探明。目前广泛应用的各种地下水示踪方法都只能确定某入口与某出口之间的连通关系,不能查明地下河道的位置。因此长期以来曾有不少人提出各种查明地下河道的方案。如在地下河中投放磁性物质,然后用磁力仪来探测河道位置。也有人提出投放小型无线电发射机,然后用无线电定向接收装置来追踪河道位置。另一种方案是投放小型定时炸弹,在地面上用地震仪接收炸弹爆炸所产生的地震波,根据地震波的到达时间来计算地下河的位置。后两种方案曾被列入全国的岩溶科研规划中。 <正> 一般的地下河虽然往往有明显的入口和出口,但地下河道的位置却很难探明。目前广泛应用的各种地下水示踪方法都只能确定某入口与某出口之间的连通关系,不能查明地下河道的位置。因此长期以来曾有不少人提出各种查明地下河道的方案。如在地下河中投放磁性物质,然后用磁力仪来探测河道位置。也有人提出投放小型无线电发射机,然后用无线电定向接收装置来追踪河道位置。另一种方案是投放小型定时炸弹,在地面上用地震仪接收炸弹爆炸所产生的地震波,根据地震波的到达时间来计算地下河的位置。后两种方案曾被列入全国的岩溶科研规划中。      

小型氰化厂的技术管理

本文简述了小型氰化厂的技术管理方法和实际操作过程,应用该方法提高选矿厂的生产技术指标和经济效益。     

Discontinuous Nature of the Lower Part of the South American Wadati-Benioff Zone in The Arica Elbow Region

The Arica Elbow region represents that part of Andean South America where the azimuth of the strike of the Peru-Chile trench changes from 150° to 190°. The area under study is roughly bounded by latitudes 17 °S and 23 °S, The shape of the Wadati-Benioff zone was studied in terms of the distribution of ISC hypocentres dated between 1964 and 1993. A system of 22 vertical cross-sections, perpendicular to the trench axis, and a map of epicentres was used to derive the detailed shape of the Wadati-Benioff zone of the presently descending slab. The distribution of earthquake foci indicates a fingerlike shape of the lower part of the Wadati-Benioff zone beneath the aseismic gap. The slab length shows small changes around 350 km in the northern sections, pronounced length oscillations between 350 and 750 km in the neighbouring central sections and a constant value of 650 km in the southern sections. The dip and thickness of the Wadati-Benioff zone are practically constant in all sections. Fault plane solutions, separated spatially into three zones, were used to estimate the state of stress in the slab.