[1] Difficulties associated with reconstructing past changes in export production were highlighted recently by Averyt and Paytan (2004), who reported substantial disagreement among records developed using different paleoproductivity proxies extracted from two equatorial Pacific piston cores. Proxies included the accumulation rates of barite, excess Ba, and excess Al, as well as elemental ratios...

Abstract In this study, polymer/glass fiber fabric‐based nanocomposite plates were fabricated with 0.01%–0.1% single‐walled carbon nanotubes (SWCNTs) and filler materials (barite, magnetite, colemanite) using a hand layup process. Mechanical properties (e.g., tensile strength, flexural Charpy impact strength), thermal conductivity, radiation shielding gamma neutron radiation) of the specimens d...

In this research, a mineral barite powder was reduced by carbon monoxide gas and the effects of reduction time and temperature was investigated as well as barite particle size. Results showed that the best result would be feasible when the barite particle sizes are between (-70 +100) in mesh scale. The barite reduction could reach the maximum level (98%) after reduction by carbon monoxide at 85...

With the advance of new exploration and production technologies, oil and gas production has gone to deeper and tighter formations than ever before. These developments have also brought challenges in scale prediction and inhibition, such as the prevention of scale formation at high temperatures (150–200 C), pressures (1,000–1,500 bar), and total dissolved solids (TDS) (>300,000 mg/L) commonly ex...

Elevated rail transit has been developed in some big cities in China in recent years. However, specialized codes for design of the bridges in the elevated rail transit system have not yet been established. Based on the prestressed concrete (PC) box girder bridges on Guangzhou metro line 4, some technical features of design principle and technology requisition, ensemble plan and design load of b...

In the Dusina area, which is built up of Lower Palaeozoic metasediments, Devonian carbonate complex and Upper Palaeozoic metarhyolites unconformably overlain by Upper Permian sediments, numerous ore occurrences have been investigated: (a) "stratabound" metamorphic hematite deposits in the pre-Devonian metasediments; (b) epigenetic veins and pipes of barite (& calcite) with accessory Hg-tetrahed...

Barite particles with a rich variety of well-defined morphologies have been synthesized by using double-hydrophilic block copolymers (which consist of a hydrophilic solvating block and a hydrophilic binding block) as crystal growth modifiers to direct the controlled precipitation of barium sulfate from aqueous solution. The influences of variation in functional group and molecular structure of ...