Selective Silica Removal in Geothermal Fluids : Implications for Applications for Geothermal Power Plant Operation and Mineral Extraction

Raw material extraction from geothermal fluids often comprises concentrating and cooling steps, which increases the risk of silica scaling formation. However, existing silica removal strategies do not consider the impact on raw material extraction. In this study, the applicability and element-selectivity of three silica removal techniques (seed-induced, lime and caustic precipitation) were tested in batch experiments using synthetic and natural geothermal fluid samples. Increasing the pH-value to 10.5 and the Ca/Si ratio > 1.25 was found to mitigate silica scaling effectively via formation of calcium-silicate-hydrate phases (C-S-H phases). The developed silica removal process does not affect the raw materials and is therefore suitable for brine mining purposes

The role of antiphase boundaries during ion sputtering and solid phase epitaxy of Si(001)

The Si(001) surface morphology during ion sputtering at elevated temperatures and solid phase epitaxy following ion sputtering at room temperature has been investigated using scanning tunneling microscopy. Two types of antiphase boundaries form on Si(001) surfaces during ion sputtering and solid phase epitaxy. One type of antiphase boundary, the AP2 antiphase boundary, contributes to the surface roughening. AP2 antiphase boundaries are stable up to 973K, and ion sputtering and solid phase epitaxy performed at 973K result in atomically flat Si(001) surfaces.Comment: 16 pages, 4 figures, to be published in Surface Scienc

Open Source Drug Discovery with the Malaria Box Compound Collection for Neglected Diseases and Beyond.

A major cause of the paucity of new starting points for drug discovery is the lack of interaction between academia and industry. Much of the global resource in biology is present in universities, whereas the focus of medicinal chemistry is still largely within industry. Open source drug discovery, with sharing of information, is clearly a first step towards overcoming this gap. But the interface could especially be bridged through a scale-up of open sharing of physical compounds, which would accelerate the finding of new starting points for drug discovery. The Medicines for Malaria Venture Malaria Box is a collection of over 400 compounds representing families of structures identified in phenotypic screens of pharmaceutical and academic libraries against the Plasmodium falciparum malaria parasite. The set has now been distributed to almost 200 research groups globally in the last two years, with the only stipulation that information from the screens is deposited in the public domain. This paper reports for the first time on 236 screens that have been carried out against the Malaria Box and compares these results with 55 assays that were previously published, in a format that allows a meta-analysis of the combined dataset. The combined biochemical and cellular assays presented here suggest mechanisms of action for 135 (34%) of the compounds active in killing multiple life-cycle stages of the malaria parasite, including asexual blood, liver, gametocyte, gametes and insect ookinete stages. In addition, many compounds demonstrated activity against other pathogens, showing hits in assays with 16 protozoa, 7 helminths, 9 bacterial and mycobacterial species, the dengue fever mosquito vector, and the NCI60 human cancer cell line panel of 60 human tumor cell lines. Toxicological, pharmacokinetic and metabolic properties were collected on all the compounds, assisting in the selection of the most promising candidates for murine proof-of-concept experiments and medicinal chemistry programs. The data for all of these assays are presented and analyzed to show how outstanding leads for many indications can be selected. These results reveal the immense potential for translating the dispersed expertise in biological assays involving human pathogens into drug discovery starting points, by providing open access to new families of molecules, and emphasize how a small additional investment made to help acquire and distribute compounds, and sharing the data, can catalyze drug discovery for dozens of different indications. Another lesson is that when multiple screens from different groups are run on the same library, results can be integrated quickly to select the most valuable starting points for subsequent medicinal chemistry efforts.Thanks to the UK DFID and the Bill and Melinda Gates Foundation Grand Challenges Explorations for providing funding for testing of the Malaria Box and funding the support of individual groups including: Medicines for Malaria Venture MMV Challenge Grant, Grant Numbers MMV 12/0048 and MMV 12/0076 (to JHA), the Australian Research Council (FT10100185 to SAP; FT0991213 to KTA and LP120200557 awarded to VMA), Bill & Melinda Gates Foundation Grant OPP1040394 to PA, OPP1040399 to DAF and VMA and OPP1086189 to KKH, OPP1069393 and OPP1119049 to ML, OPP1024029 to CN, the Bloomberg Family Foundation (JBr), JHMRI for a predoctoral fellowship, the US NIH for the CBI training grant T32GM080189 (to LEB), R01GM104486 (to PAW & WS), R01AI117017 (to JHA) the National Science Foundation Graduate Research Fellowship Program Grant No.DGE-1232825 (DDCL), the South African Medical Research Council Strategic Health Innovation Partnerships (grant V6YBT51 to DM) and the Council for Scientific and Industrial Research (grant V1YTB95, to DM), and the French ANR program Mammamia (ANR-12-BS07-0020-01)

Shorter can Also be Better: The Abridged Job in General Scale

The Job Descriptive Index family of job attitude measures includes the Job in General (JIG) scale, a measure of global satisfaction with one’s job. The scale was originally developed and validated by Ironson, Smith, Brannick, Gibson, and Paul. Following structured scale reduction procedures developed by Stanton, Sinar, Balzer, and Smith, the current authors developed an abridged version of the JIG for use by practitioners and researchers of organizational behavior. They report the results of three validation studies documenting the process of scale reduction and the psychometric suitability of the reduced-length scale

Selective Silica Removal in Geothermal Fluids : Implications for Applications for Geothermal Power Plant Operation and Mineral Extraction

Raw material extraction from geothermal fluids often comprises concentrating and cooling steps, which increases the risk of silica scaling formation. However, existing silica removal strategies do not consider the impact on raw material extraction. In this study, the applicability and element-selectivity of three silica removal techniques (seed-induced, lime and caustic precipitation) were tested in batch experiments using synthetic and natural geothermal fluid samples. Increasing the pH-value to 10.5 and the Ca/Si ratio > 1.25 was found to mitigate silica scaling effectively via formation of calcium-silicate-hydrate phases (C-S-H phases). The developed silica removal process does not affect the raw materials and is therefore suitable for brine mining purposes