The geochemical evolution of very dilute CO2‐rich water in Chungcheong Province,Korea: processes and pathways

A geochemical study was carried out on the CO₂‐rich water occurring in granite areas of Chungcheong Province, Korea. In this area, very dilute and acidic CO₂‐rich waters [62–242 mg l^?1 in total dissolved solid (TDS), 4.0–5.3 in pH; group I) occur together with normal CO₂‐rich waters (317–988 mg l^?1 in TDS, 5.5–6.0 in pH; group II). The concentration levels and ages of group I water are similar to those of recently recharged and low‐mineralized groundwater (group III). Calculation of reaction pathways suggests that group I waters are produced by direct influx of CO₂ gas into group III type waters. When the groundwater is injected with CO₂, it develops the capacity to accept dissolved solids and it can evolve into water with very high solute concentrations. Whether the water is open or closed to the CO₂ gases becomes less important in controlling the reaction pathway of the CO₂‐rich groundwater when the initial pco ₂ is high. Our data show that most of the solutes are dissolved in the CO₂‐rich groundwater at pH > 5 where the weathering rates of silicates are very slow or independent of pH. Thus, groundwater age is likely more important in developing high solute concentrations in the CO₂‐rich groundwaters than accelerated weathering kinetics because of acidic pH caused by high pco ₂.     

The Application of Steroidal Biomarkers to Track the Abandonment of a Roman Wastewater Course at the Agora (Athens,Greece)*

A subterranean, stone‐built, sediment‐filled culvert discovered during excavations at the Agora (Athens, Greece) was dated to the Roman period on the basis of its characteristic construction and associated finds, including coins. The location of the culvert relative to other adjacent watercourses and an ancient river bed suggested that the structure was a sewer. This was confirmed through a multi‐molecular biomarker approach based on analysis of the bile acids associated with sediment filling the sewer, using gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). The acid fraction contained predominantly deoxycholic and lithocholic acids, while the neutral steroid fraction comprised a complex mixture of Δ⁵ sterol and 5β‐ and 5α‐stanols, dominated by coprostanol, suggesting the presence of faecal matter of predominantly human origin. The concentrations of neutral and acidic faecal biomarkers were observed to vary in tandem, with the highest concentrations being found in the sediment at the base of the fill in the culvert. A reduction in concentration occurred with decreasing depth of the fill, with concentrations in the uppermost samples being little different from control samples of sediment taken beyond the confines of the culvert. The enhanced concentration of bile acids relative to 5β‐stanols compared with fresh human faeces must reflect the enhanced diagenetic stability of the former, thereby making bile acids the possibly preferred biomarker for this type of study. The quantitative data obtained suggest that the culvert fell rapidly out of use, possibly coinciding with the Slavic incursion in AD 582–3.     

The Patchwork and Adjustment of the Bronze Ding-Tripod of the Chu Tombs in the Warring States Period

The use of ding-tripod in Chu tombs was well established in the Warring States period and in most cases, it was strictly implemented. However, exceptions do exist. For example, in tomb of Marquis Yi of the Zeng state, archaeologists found two qiao-ding, which consists of two ding- tripods, one with a fitted lid and the other with a hooped lid. In the tomb No. 1 at Jiuliandun, a ding-tripod with a hooped lid was intentionally used and served as xu-ding. This paper attempts to understand burial rituals of the Chu state during the Warring State period by examining the tomb inventories (catalogues of funerary goods in the tombs) unearthed from the tomb No. 2 at Baoshan. It proposes that the use of ding-tripod in tombs was often adjusted according to the burial rituals.     

青铜古镜表面层富硅的考察

运用扫描电子显微镜、电子探针微量分析、X射线衍射、原子力显微镜和红外反射光谱等分析手段对16块古青铜镜残片的合金基体及表面层进行了分析比较,结果发现表面层内Cu含量低于基体,而Sn．O的含量则明显增高;表面层内有Si元素的富集,并且是以SiO_2非晶形态存在;对于不同种类的青铜镜,表面层深度不同,含Si量有差异,其表面光亮度和釉质感亦有区别。对古铜镜颜色的变化,SiO_2的保护作用及铜镜表面的加工工艺进行了分析探讨。     

Substitute or addition to hypermobile lifestyles? Second home mobility and Finnish CO2 emissions

Tourism produces an increasing share in global greenhouse gas (GHG) emissions. These are mostly derived from transport emissions, and long-haul air travel in particular. Short-haul domestic tourism is believed by some to be a potential substitute for long-haul tourism. Using the example of Finland this paper examines the extent to which domestic second home tourism can substitute for other leisure trips and therefore contribute to reductions of travel-generated GHG emissions. Survey data are used to evaluate the CO₂ emissions caused by travel to domestic second homes, and to create statistical models that verify if the owners of domestic second homes travel to other leisure destinations less frequently than others, and if they cause less emissions by their leisure mobility than others with comparable economic and demographic background. We find that although the owners and users of domestic second homes travel for other leisure purposes less frequently than others, this does not mean their leisure mobility generates less emissions. Overall, owners of second homes produce significantly more CO₂ by their leisure mobility than non-owners. The use of second homes does not seem to be a substitute for high emission long-haul travels, but rather a part of an overall highly mobile leisure lifestyle. It is therefore necessary to better understand and influence the entire range of individual mobility behaviours in order to reduce travel-related GHG emissions.     

Geometry‐coupled reactive fluid transport at the fracture scale: application to CO2 geologic storage

Water acidification follows CO₂ injection and leads to reactive fluid transport through pores and rock fractures, with potential implications to reservoirs and wells in CO₂ geologic storage and enhanced oil recovery. Kinetic rate laws for dissolution reactions in calcite and anorthite are combined with the Navier‐Stokes law and advection–diffusion transport to perform geometry‐coupled numerical simulations in order to study the evolution of chemical reactions, species concentration, and fracture morphology. Results are summarized as a function of two dimensionless parameters: the Damköhler number Da which is the ratio between advection and reaction times, and the transverse Peclet number Pe defined as the ratio between the time for diffusion across the fracture and the time for advection along the fracture. Reactant species are readily consumed near the inlet in a carbonate reservoir when the flow velocity is low (low transverse Peclet number and Da > 10^?1). At high flow velocities, diffusion fails to homogenize the concentration field across the fracture (high transverse Peclet number Pe > 10^?1). When the reaction rate is low as in anorthite reservoirs (Da < 10^?1), reactant species are more readily transported toward the outlet. At a given Peclet number, a lower Damköhler number causes the flow channel to experience a more uniform aperture enlargement along the length of the fracture. When the length‐to‐aperture ratio is sufficiently large, say l/d > 30, the system response resembles the solution for 1D reactive fluid transport. A decreased length‐to‐aperture ratio slows the diffusive transport of reactant species to the mineral fracture surface, and analyses of fracture networks must take into consideration both the length and slenderness of individual fractures in addition to Pe and Da numbers.     

Bleached mudstone,iron concretions,and calcite veins: a natural analogue for the effects of reducing CO2‐bearing fluids on migration and mineralization of iron,sealing properties,and composition of mudstone cap rocks

This study investigates the Wangfu Depression of the Songliao Basin, China, as a natural analogue site for Fe migration (bleaching) and mineralization (formation of iron concretions) caused by reducing CO₂‐bearing fluids that leak along fractures after carbon capture, utilization, and storage. We also examined the origin of fracture‐filling calcite veins, the properties of self‐sealing fluids, the influence of fluids on the compositions of mudstone and established a bleaching model for the study area. Our results show that iron concretions are the oxidative products of precursor minerals (pyrite and siderite) during uplift and are linked to H₂S and CO₂ present in early stage fluids. The precipitation of calcite veins is the result of CO₂ degassing and is related to CO₂, CH₄, and minor heavy hydrocarbons in the main bleaching fluids. In our model, fluids preferentially enter high‐permeability fracture systems and result in the bleaching of surrounding rocks and precipitation of calcite veins. The infilling of calcite veins significantly decreases the permeability of fractures and forces the fluids to slowly enter and bleach the mudstone rocks. The Fe²⁺ released during bleaching migrates to elsewhere with the solutions or is reprecipitated in the calcite veins and iron concretions. The formation of calcite veins reduces the fracture space and effectively prevents fluid flow. The fluids have an insignificant effect on minerals within the mudstone. In terms of the chemistry of the mudstone, only the contents of Fe₂O₃, U, and Mo change significantly, with the content of U increasing in the mudstone and the contents of Fe₂O₃ and Mo decreasing during bleaching.     

Isaiah b. Amoz’s Attitude towards the Faith of the Gentile Nations

This article discusses the pilgrimage of the nations to Zion described in Isa 2,2-5, focusing on Isaiah’s attitude to their future faith in the God of Israel. A number of ways of understanding Isaiah’s view are proposed on the basis of a series of ever-widening interpretive circles. These are determined by their linguistic and/or substantive and/or cognitive affinities with the vision, influencing the exegesis of the vision either through their content or the worldview they reflect. None of the circles entails a reading of the vision as a closed unit isolated from its context.     

Contests about Natural Law in Early Enlightenment Copenhagen

This article discusses the works of the first two lecturers on natural law in Copenhagen, Henrik Weghorst and Christian Reitzer. Contrary to the existing scholarship which characterises their works as derivative of either Grotius or Pufendorf, the article argues that the character and significance of these works can only be grasped when understood in light of the local intellectual traditions which they built upon. Seen against this background, it becomes clear that Weghorst and Reitzer developed significantly different theories of natural law, disagreeing on such fundamental issues as the definition of law, the moral good, and the role of sociality in natural law. Following a tradition of Christian natural law in Kiel, Weghorst developed a theory of natural law fundamentally critical of the secularising theories of Grotius and Pufendorf, while Reitzer followed Pufendorf and his disciple Christian Thomasius in Halle. The article concludes by indicating how Weghorst’s and Reitzer’s works established the framework for discussions of natural law in the first decades of the eighteenth century, suggesting the need for further research into the significance of natural law for the early enlightenment in Denmark–Norway.