In-situ cosmogenic ³⁶Cl denudation rates of carbonates in Guizhou karst area

This study quantifies surface denudation of carbonate rocks by the first application of in-situ cosmogenic <sup>36</sup>Cl in China. Concentrations of natural Cl and in-situ cosmogenic <sup>36</sup>Cl in bare carbonates from Guizhou karst areas were measured with isotope dilution by accelerator mass spectrometer. The Cl concentration varied from 16 to 206 ppm. The <sup>36</sup>Cl concentrations were in range of (0.8–2.4)×106 atom g−1, resulting in total denudation rates of 20–50 mm ka−1 that averaged over a 104–105 a timescale. The <sup>36</sup>Cl-denudation rates showed roughly a negative correlation with the local mean temperature. This preliminary observation may suggest the variations of proportions of chemical weathering and physical erosion in denudation process, depending upon local climatic conditions

An evaluation of coding methodologies for potential use in the Alabama Resource Information System (ARIS)-transportation study for the state of Alabama

Procedures developed for digitizing the transportation arteries, airports, and dock facilities of Alabama and placing them in a computerized format compatible with the Alabama Resource Information System are described. The time required to digitize by the following methods: (a) manual, (b) Telereadex 29 with film reading and digitizing system, and (c) digitizing tablets was evaluated. A method for digitizing and storing information from the U. T. M. grid cell base which was compatible with the system was developed and tested. The highways, navigable waterways, railroads, airports, and docks in the study area were digitized and the data stored. The manual method of digitizing was shown to be best for small amounts of data, while the graphic input from the digitizing tablets would be the best approach for entering the large amounts of data required for an entire state

Soil, grain and water chemistry and human selenium imbalances in Enshi district, Hubei Province, China

Many elements which are essential to human and other animal health in small doses can be toxic if ingested in excess. Selenium (Se), a naturally occurring metalloid element is found in all natural materials on earth including rocks, soils, waters, air, plant and animal tissues. Since the early 1930’s, it has been recognised that Se toxicity causes hoof disorders and hair loss in livestock. Se was also identified as an essential trace element to humans and other animals in the late 1950’s. It forms a vital constituent of the biologically important enzyme glutathione peroxidase which acts as an anti-oxidant preventing cell degeneration. Se deficiency has been implicated in the aetiology of several diseases including cancer, muscular dystrophy, muscular sclerosis and cystic fibrosis. Se can be assimilated in humans through several pathways including food, drinking water and inhalation of Se-bearing particles from the atmosphere. In the majority of situations, food is the most important source of Se, as levels in water are very low. The narrow range between deficiency levels (<40 pg per day) and toxic levels in susceptible people (> 900 pg per day) makes it necessary to carefully control the amount of Se in the diet. In China, Se deficiency has been linked to an endemic degenerative heart disease known as Keshan Disease (KD) and an endemic osteoarthropathy which causes deformity of affected joints, known as Kaschin-Beck Disease. These diseases occur in a geographic belt stretching from Heilongjiang Province in north-east China to Yunnan Province in the south-west. In the period between 1959 and 1970, peak KD incidence rates exceeded 40 per 100 000 (approximately 8500 cases per annum) with 1400 - 3000 deaths recorded each year. Incidence rates have since fallen to less than 5 per 100 000 with approximately 1000 new cases reported annually (Levander, 1986). Se toxicity (selenosis) resulting in hair and nail loss and disorders of the nervous system in the human population, has also been recorded in Enshi District, Hubei Province and in Ziyang County, Shanxi Province. China possesses one of the best epidemiological databases in the world on Se-related diseases which has been used in conjunction with geochemical data to demonstrate a significant geochemical control on human Se exposure. However, the precise geographical areas at risk and the geochemical controls on selenium availability have yet to be established

Development of a novel combined catalyst and sorbent for hydrocarbon reforming

A combined catalyst and sorbent was prepared and utilized for steam reforming methane and propane in laboratory-scale systems. The material was prepared in the form of small spherical pellets having a layered structure such that each pellet consisted of a highly reactive lime or dolime core enclosed within a porous but strong protective shell made of alumina in which a nickel catalyst was loaded. The material served two functions by catalyzing the reaction of hydrocarbons with steam to produce hydrogen while simultaneously absorbing carbon dioxide formed by the reaction. The in situ removal of CO 2 shifted the reaction equilibrium toward increased H 2 concentration and production. The concept was proved by using both a thermogravimetric analyzer and a fixed-bed reactor loaded with the material to reform hydrocarbons. Tests conducted with the fixed-bed reactor at atmospheric pressure and with temperatures in the range of 520-650°C produced a product containing a large concentration of H 2 (e.g., 94-96 mol %) and small concentration of CO and CO 2. Therefore, the results achieved in a single step were as good as or better than those achieved in a conventional multistep reaction and separation process

Field and laboratory experiments on high dissolution rates of limestone in stream flow

Field and laboratory experiments were performed to examine dissolution rates of limestone in stream flow. Field experiments were conducted in three stream sites (A–C) with different lithological or hydrological settings around a limestone plateau in the Abukuma Mts., Japan. Sites A and B are allogenic streams, which flow from non-limestone sources into dolines, and site C has a karst spring source. Tablets made of limestone from the same plateau with a diameter of 3.5 cm and a thickness of 1 cm were placed in the streams for 3 years (2008–2011) where alkalinity, pH and major cation concentrations were measured periodically. The saturation indices of calcite (SIc) of stream water were − 2.8 ± 0.4 at site A, − 2.5 ± 0.4 at site B and − 0.5 ± 0.4 at site C. Annual weight loss ratios for tablets were extremely high at site A (0.11–0.14 mg cm− 2 d− 1), high at site B (0.05 mg cm− 2 d− 1), and low at site C (0.005 mg cm− 2 d− 1). The contrasting rates of weight loss are mainly explained by chemical conditions of stream water. In addition, laboratory experiments for dissolution of limestone tablets using a flow-through apparatus revealed that flow conditions around the limestone tablet is another important factor for dissolution in the stream environment. These results revealed that limestone dissolves at a rapid rate where water unsaturated to calcite continuously flows, such as in an allogenic stream

Detecting chloride contamination of objects and buildings: evaluating a new testing process

Soluble salts play a key factor in damage to a variety of materials, including stone, ceramics and metals. Particularly, salt contamination can lead to weakening of porous materials through salt crystallisation events, and increases the rate of metal corrosion. Over time, this results in physical damage to affected objects and buildings. It is therefore important to be able to monitor the salt content of materials, in order to understand levels of salt contamination and the potential for damage to occur. This research discusses the further development of the testing method for surface chlorides originally proposed by Piechota and Drake Piechota (2016) in their article “A simple survey kit for chloride detection on cuneiform tablets and other collections”. It introduces new and revised steps into the original protocol in order to make the achieved results semi-quantifiable, as well as identifying the limits of detection of the test kit. A comparison to alternative testing methods showed that comparable results were achievable using this methodology. The revised methodology was tested for efficacy on a range of salt contaminated objects, as well as on samples from buildings

Evidence from Escalera al Cielo: Abandonment of a Terminal Classic Puuc Maya Hill Complex in Yucatán, Mexico

This is a postprint (author's final draft) version of an article published in Journal of Field Arhcaeology in 2012. The final version of this article may be found at http://dx.doi.org/10.1179/0093469012Z.00000000025 (login may be required). The version made available in OpenBU was supplied by the author.Excavations at the hilltop site of Escalera al Cielo, located in the Puuc Maya region of Yucatán, Mexico, have uncovered evidence of a planned abandonment at the end of the Terminal Classic period (A.D. 800–950). Six buildings investigated among three residential groups contain rich floor assemblages similar to those known from only a few rapidly abandoned sites in the Maya area. Through an analysis of de facto refuse—most of which was recovered in locations of storage and provisional discard—and midden refuse, this paper illustrates how the assemblages represent an example of household-level abandonment with anticipated return. We also consider Escalera al Cielo in light of our present understanding of the political and environmental history of the Puuc region during the late 9th century A.D

Engineering properties of bio-inspired cement mortar containing seashell powder

Cement mortar is a semi liquid formed by a composite of cement, sand and water. Generally, cement mortar is used as a medium for bricks laying in construction. Nowadays, the properties of various types of waste materials are studied as construction material in buildings such as blast furnace ash, fly ash and palm oil fuel ash. In this study, the seashell is used as a replacement of building material in cement mortar.Seashell consists of high amount of calcium carbonate that provides remarkable mechanical properties and suitable to be used as building material. The engineering properties of cement mortar is studied, which including the compressive strength, flexural strength, splitting tensile strength, durability, modulus of elasticity in compression, setting time, water absorption and shrinkage. Cockle (Anadaragranosa) and mussel (Pernaviridis) are selected to replace the sand in the cement mortar with a ratio of 0, 25, 50, 75, and 100 percent by total weight of sand. A total number of 2800samples are prepared and tested up to 1 year and subjected to four exposure conditions, which are water, air, natural weather and wet-dry cycle.The replacement of seashell in cement mortar is likely to increase its engineering properties especially compressive strength due to high amount of calcium carbonate.The replacement of seashell in cement mortar will reduce the construction cost, improve the engineering properties of mortar and can be applied in various mortar applications

Ghana airborne geophysics project in the Volta and Keta Basin : BGS final report

This report describes the work undertaken by BGS between November 2006 and March 2009 in collaboration with Fugro Airborne Surveys Pty Ltd on an airborne geophysical survey and ground reconnaissance mapping of the Volta River and Keta Basins, Ghana. The project was supported by the EU as part of the Mining Sector Support Programme, Project Number 8ACP GH 027/13. The initial contract duration was three years, but this was extended by five months to account for acquisition of gravity data by another project. Some parts of Ghana have been airborne surveyed as part of the Mining Sector Development and Environmental Project, co-funded by the World Bank and the Nordic Development Fund, but no work was carried out on the Volta River and Keta basins, which together form a major portion of the Ghanaian territory. The approximate areas covered by the surveys are estimated at 98,000 km² for the satellite imagery and the airborne geophysics, except for the Time Domain Electromagnetic (TDEM) survey which was limited to 60,000 km². The main beneficiary of this project is the Geological Survey Department, GSD. The work enhanced its geological infrastructure and its personnel received hands-on training on modern geological mapping technology. Indirect beneficiaries were the mining and exploration companies that can follow up the reconnaissance work with detailed exploration work. The project was conducted in five phases, and this document reports on the BGS input to Phase 1, 4 and 5, with no inputs required in Phases 2 and 3: • Phase1: geological outline through Radar and optical satellite imageries. • Phase 2: airborne geophysical survey over the two basins for magnetics and Gamma Ray spectrometry (Fugro survey). • Phase 3: airborne electromagnetic and magnetic geophysical survey of specific areas, following the completion and interpretation of phase 2, using fixed wing time domain technology (Fugro survey). • Phase 4: interpretation of the combined geology and geophysics. • Phase 5: production of factual and interpretation maps. The full list of BGS products is outlined in Table 1 below, while Jordan et al. (2006) describe the products delivered on schedule in Phase 1

Revealing the last 13,500 years of environmental history from the multiproxy record of a mountain lake (Lago Enol, northern Iberian Peninsula)

This is the author's accepted manuscript. The final publication is available at Springer via http://dx.doi.org/10.1007/s10933-009-9387-7.We present the Holocene sequence from Lago Enol (43°16′N, 4°59′W, 1,070 m a.s.l.), Cantabrian Mountains, northern Spain. A multiproxy analysis provided comprehensive information about regional humidity and temperature changes. The analysis included sedimentological descriptions, physical properties, organic carbon and carbonate content, mineralogy and geochemical composition together with biological proxies including diatom and ostracod assemblages. A detailed pollen study enabled reconstruction of variations in vegetation cover, which were interpreted in the context of climate changes and human impact. Four distinct stages were recognized for the last 13,500 years: (1) a cold and dry episode that includes the Younger Dryas event (13,500–11,600 cal. year BP); (2) a humid and warmer period characterizing the onset of the Holocene (11,600–8,700 cal. year BP); (3) a tendency toward a drier climate during the middle Holocene (8,700–4,650 cal. year BP); and (4) a return to humid conditions following landscape modification by human activity (pastoral activities, deforestation) in the late Holocene (4,650–2,200 cal. year BP). Superimposed on relatively stable landscape conditions (e.g. maintenance of well established forests), the typical environmental variability of the southern European region is observed at this site.The Spanish Inter-Ministry Commission of Science and Technology (CICYT), the Spanish National Parks agency, the European Commission, the Spanish Ministry of Science, and the European Social Fund