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...

The term "Carlin-type" deposit has been applied to a number of low-grade, sedimentary rock-hosted gold deposits that have been discovered and brought into production in the western United States since the 1960s. Carlin-type deposits are characterized by replacement of carbonate and silty carbonate rocks by silica, pyrite, barite, various arsenic, mercury, antimony, and thallium minerals and by ...

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...

The phylogenetic positions of sulfate-reducing organisms, as revealed from comparisons of small-subunit ribosomal RNA (SSU rRNA), are spread over both the Archaeal and Bacterial domains, though when they evolved is uncertain. The lowbranching positions of some of these groups on the Tree of Life have inspired the hypothesis that the metabolic innovation of microbial sulfate reduction is of grea...

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 ...

ABSTRACT  Introduction: Recently uses of medium and high energy x-rays has been increased in Iran and radiotherapy centers along with a variety of accelerators have been installed in some provinces. In the other hand there is no sufficient skill in designing and making radiotherapy treatment rooms. This study was conducted to evaluate the efficacy of different m...

Abstract The Anarraaq clastic-dominated (CD) Zn-Pb-Ag deposit (Red Dog district, Alaska, USA) has an inferred mineral resource of 19.4 Mt at 14.4% Zn, 4.2% Pb, and 73 g/t Ag is spatially associated with a separate ~1 Gt barite body. This study presents new cross sections petrographic evidence from the area. body, previously shown to have formed in shallow subsurface environment akin methane col...