The exploration of Sr isotopic analysis applied to Chinese glazes: part one

Ash glaze and limestone glaze are two major glaze types in southern Chinese ceramic technology. In this study strontium isotope compositions were determined in ash glaze samples from the Yue kiln dated to between the 10th and 12th centuries AD, limestone glaze samples from Jingdezhen dated to between the 15th and 18th centuries AD and ceramic raw materials from Jingdezhen. The Sr isotopic characteristics of limestone glaze and ash glaze are completely different. The Sr isotope characteristics of limestone glaze is characterised by low Sr concentrations, large 87Sr/86Sr variation, and a two component mixing line. On the other hand the strontium isotope characteristic of ash glaze samples is characterised by a consistent 87Sr/86Sr signature and high Sr concentrations with a large variation. The different Sr isotope compositions for the two types of glazes are a reflection of the various raw materials involved in making them. The Sr isotopic composition has been altered by the refinement process that the raw material was subjected to. It was found that the mineralogical changes caused by the alteration are reflected in the Sr isotope results. The potential of Sr isotopic analysis of Chinese glazes is evaluated according to the results produced by this, the first such stud

Searching for the earliest use of limestone as a flux in Chinese high-fired ceramic glazes—evidence from Sr isotopic analysis of Chinese northern porcelain

Samples of northern porcelain wares dating to between the 6th and 13th centuries from the three most important northern Chinese ceramic kiln sites, Gongyi, Xing and Ding have been studied in this work. The Sr isotope and chemical compositions of the ceramic glazes of these wares have been determined. Based on the scientific results we have been able to suggest the raw materials used to make the glazes. Using Strontium isotopic analysis we have successfully shown that the earliest use of limestone as a glaze flux so far identified is during the period from the Sui to mid-Tang Dynasties (late 6th-early 9th century) to produce white slip glazed ware in the Xing kilns so it may have been ‘invented’ there

Feeding the Roman army in Britain

How did the Roman Empire supply and maintain its frontier garrisons? What was the impact on populations and landscapes of conquered territories? The Feeding the Roman Army in Britain project will answer these questions by establishing how soldiers were provisioned and how frontiers operated as economic as well as militarised zones

Feeding the Roman Army in Britain

How did the Roman Empire supply and maintain its frontier garrisons? What was the impact on populations and landscapes of conquered territories? The Feeding the Roman Army in Britain project will answer these questions by establishing how soldiers were provisioned and how frontiers operated as economic as well as militarised zones

Sirt7 protects against vascular calcification via modulation of reactive oxygen species and senescence of vascular smooth muscle cells

Vascular calcification is frequently seen in patients with chronic kidney disease (CKD), and significantly increases cardiovascular mortality and morbidity. Sirt7, a NAD+-dependent histone deacetylases, plays a crucial role in cardiovascular disease. However, the role of Sirt7 in vascular calcification remains largely unknown. Using in vitro and in vivo models of vascular calcification, this study showed that Sirt7 expression was significantly reduced in calcified arteries from mice administered with high dose of vitamin D3 (vD3). We found that knockdown or inhibition of Sirt7 promoted vascular smooth muscle cell (VSMC), aortic ring and vascular calcification in mice, whereas overexpression of Sirt7 had opposite effects. Intriguingly, this protective effect of Sirt7 on vascular calcification is dependent on its deacetylase activity. Unexpectedly, Sirt7 did not alter the osteogenic transition of VSMCs. However, our RNA-seq and subsequent studies demonstrated that knockdown of Sirt7 in VSMCs resulted in increased intracellular reactive oxygen species (ROS) accumulation, and induced an Nrf-2 mediated oxidative stress response. Treatment with the ROS inhibitor N-acetylcysteine (NAC) significantly attenuated the inhibitory effect of Sirt7 on VSMC calcification. Furthermore, we found that knockdown of Sirt7 delayed cell cycle progression and accelerated cellular senescence of VSMCs. Taken together, our results indicate that Sirt7 regulates vascular calcification at least in part through modulation of ROS and cellular senescence of VSMCs. Sirt7 may be a potential therapeutic target for vascular calcification.</p

New light on plant ash glass found in Africa: evidence for Indian Ocean Silk Road trade using major, minor, trace element and lead isotope analysis of glass from the 15th—16th century AD from Malindi and Mambrui, Kenya

Seventeen glass vessels and twenty glass beads recovered from the excavations at the ancient city of Malindi and the archaeological site of Mambrui in Kenya, east Africa were analysed using electron probe microanalysis (EPMA) and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). The results show that all of the glass samples are soda-lime-silica glass. They belong to the high alumina -plant ash glass type, characterised by high alumina and relatively low calcium contents, widely distributed in eastern (10th- 16th centuries AD) and southern Africa (13th - 15th centuries AD), Central Asia (9th- 14th centuries AD) and southeast Asia (12th- 13th centuries AD), made with plant ashes and sands. This is an understudied glass type for which previous research has indicated there were three types. When compared with published research on such glasses using Zr, Ti, Ba, Cr, La, Li, Cs, Na2O, MgO and CaO we have identified at least four different compositional groups of v-Na-Al glass: Types A, B, C and D. By comparing the results with contemporary v-Na-Al glass vessels and beads from Central Asia, Africa, and southeast Asia we show that most of the Malindi and Mambrui glass share similar characteristics to the compositions of Mapungubwe Oblate and some of the Madagascar glass beads from southern Africa. They belong to Type A v-Na-Al glass which is characterised by an elevated level of Ti and Ba and a relatively high ratios of Cr/La, relatively low Zr concentrations and low ratios of Zr/ Ti. Differences in Zr, Li, MgO and Na2O concentrations in Type A glass indicates that there are subgroups which might derive from different glass workshop(s) specialising in Type A v- Na-Al glass production. Comparison with the chemical compositions of glass from Ghazni, Afghanistan and Termez, Uzbekistan, and by using lead isotope analysis, we suggest v-Na- Al glass was manufactured in Central Asia and possibly worked into vessels and beads there. Copyright: © 2020 Siu et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Isotopic investigations of Chinese ceramics

This chapter provides insights into Chinese ceramic technologies of both bodies and glazes as well as provenance by using isotopes applied to a number of case studies. The use of Sr isotopes to investigate Chinese high-fired Celadon wares and blue-and-white Jingdezhen porcelain (Jiangxi province) has revealed a clear distinction associated with the fluxes used in the glazes: plant ash in celadons and limestone in Jingdezhen glazes, something that is not clear from major element analysis. Furthermore, the technique is able to suggest by implication the nature of the silica source used in the glazes—normally weathered granitic rocks or metamorphic rocks (porcelain stone) which also contains Sr. This leads to an isotopic mixing line of the 2 Sr-rich components and is proof that 2 Sr-rich components were mixed in the manufacture of limestone glaze. This is not the case for plant ash glazes. Eventually, the technique may be used in provenance studies. Like Sr isotope analysis, lead isotope analysis relies on there being a lack of or a minimal change in the isotope ratios when the raw materials are heated. Lead isotope analysis links the use of lead in glazes to the original metal ore and if a kiln uses a distinctive lead source in its glazes, it can provide a provenance for the pottery. This has been very successful in distinguishing Chinese Tang sancai wares made in the Huangye, Huangbao, Liquanfang and Qionglai kilns

A Developed Artificial Bee Colony Algorithm Based on Cloud Model

The Artificial Bee Colony (ABC) algorithm is a bionic intelligent optimization method. The cloud model is a kind of uncertainty conversion model between a qualitative concept T &tilde; that is presented by nature language and its quantitative expression, which integrates probability theory and the fuzzy mathematics. A developed ABC algorithm based on cloud model is proposed to enhance accuracy of the basic ABC algorithm and avoid getting trapped into local optima by introducing a new select mechanism, replacing the onlooker bees&rsquo; search formula and changing the scout bees&rsquo; updating formula. Experiments on CEC15 show that the new algorithm has a faster convergence speed and higher accuracy than the basic ABC and some cloud model based ABC variants

A new method of identifying the flux in ancient Chinese High Fired Glaze: Sr isotopic composition analysis

The following sections are included: Introduction Methodology Section one: The study of Sr isotopic compositions of Jingdezhen porcelain glaze, Yue plant ash glaze and the raw materials used to make them Section two: The study of Sr isotopic compositions of Ming Dehua ‘Blanc de Chine’ porcelain glaze, Qing Dehua blue-and-white glaze and their flux components Overall conclusions Reference

Synthesis of Porous Materials Using Magnesium Slag and Their Adsorption Performance for Lead Ions in Aqueous Solution

Magnesium slag-based porous materials (MSBPM) were successfully synthesized using alkali activation and foaming methods as an effective adsorbent for Pb2+ in solution. The effects of foaming agent type, foaming agent dosage, alkali dosage, and water glass modulus on the properties of the MSBPM were studied, and the micromorphology and porosity of the MSBPM were observed using microscopy. The influence of pH value, initial concentration, and adsorbent dosage on the Pb2+ adsorption was investigated. The results showed that a porous material (MSBPM-H2O2) with high compressive strength (8.46 MPa) and excellent Pb2+ adsorption capacity (396.11 mg·g−1) was obtained under the optimal conditions: a H2O2 dosage of 3%, an alkali dosage of 9%, a water glass modulus of 1.3, and a liquid–solid ratio of 0.5. Another porous material (MSBPM-Al) with a compressive strength of 5.27 MPa and the Pb2+ adsorption capacity of 424.89 mg·g−1 was obtained under the optimal conditions: an aluminum powder dosage of 1.5‰, an alkali dosage of 8%, a water glass modulus of 1.0, and a liquid–solid ratio of 0.5. When the pH of the aqueous solution is 6 and the initial Pb2+ concentrations are 200~500 mg·L−1, the MSBPM-H2O2 and MSBPM-Al can remove more than 99% of Pb2+ in the solution. The adsorption process of both materials followed the Langmuir isotherm model and pseudo-second-order kinetic model, indicating that the adsorption process was a single-molecule layer chemical adsorption