scholarly journals Bioleaching of Gold from Silicate Ore by Macrococcus caseolyticus and Acinetobacter calcoaceticus: Effect of Medium, Amino Acids and Growth Supernatant

Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 580
Author(s):  
Kanjana Kudpeng ◽  
Parinda Thayanukul ◽  
Paitip Thiravetyan
Keyword(s):  
Amino Acids ◽  
High Performance ◽  
Acinetobacter Calcoaceticus ◽  
Gold Leaching ◽  
Term Operation ◽  
Carboxylic Groups ◽  
Amine Groups ◽  
Ph Conditions ◽  
The Fourier Transform

The aims of this work were to study the gold leaching by the isolated bacteria from silicate ore. Three strains were isolated and identified as Macrococcus caseolyticus, Acinetobacter calcoaceticus, and Bacillus sp. MBEA40. However, only M. caseolyticus and A. calcoaceticus were capable of gold bioleaching. In order to examine only the effect of microorganisms involved in the gold bioleaching process, minimal medium and ethanol mineral salt medium without amino acids were used for culturing M. caseolyticus and A. calcoaceticus, respectively. The result showed that the growth supernatant (in the absence of microorganisms) of both strains might be more suitable to leaching gold from ore than leaching by microorganisms (in the presence of microorganisms) directly. This might be due to the fact that there is no interference of gold absorption and metal toxicity in microorganisms in the long-term operation. The result also confirmed that amino acids/peptides/proteins produced by microorganisms might be involved in gold bioleaching, as shown in the high-performance liquid chromatography (HPLC) results. The Fourier transform infrared spectroscopy (FTIR) study also found that amine groups and carboxylic groups played important roles in gold bioleaching by M. caseolyticus and A. calcoaceticus. In addition, the bioleaching process had significantly higher gold leaching than mixed pure amino acids due to the growth supernatant containing mixed amino acids/peptides/proteins and other compounds. Therefore, the growth supernatant of M. caseolyticus and A. calcoaceticus can be applied in gold bioleaching under neutral pH conditions, which is considered to be a safe, not corrosive, and environmentally friendly leaching process. This study is also needed further study in order to increase the percentage of gold bioleaching and decrease times.

Guidelines for Long-Term Operation of High Performance Submersible Motor Pumps in Mine Dewatering

2021 ◽  
Author(s):  
Sebastian Wulff ◽  
David Beck ◽  
Morris Reich ◽  
Jean Pierre Worringer ◽  
Paul Uwe Thamsen
Keyword(s):  
High Performance ◽  
Term Operation ◽  
Mine Dewatering ◽  
Submersible Motor

scholarly journals Tailoring Charged Nanofiltration Membrane Based on Non-Aromatic Tris(3-aminopropyl)amine for Effective Water Softening

Membranes ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 251
Author(s):  
Pengrui Jin ◽  
Michiel Robeyn ◽  
Junfeng Zheng ◽  
Shushan Yuan ◽  
Bart Van der Bruggen
Keyword(s):  
High Performance ◽  
Molecular Structures ◽  
Water Softening ◽  
Selective Layer ◽  
Long Term Stability ◽  
Composition And Structure ◽  
Amine Groups ◽  
High Rejection ◽  
Positively Charged

High-performance positively-charged nanofiltration (NF) membranes have a profound significance for water softening. In this work, a novel monomer, tris(3-aminopropyl)amine (TAEA), with one tertiary amine group and three primary amine groups, was blended with trace amounts of piperazine (PIP) in aqueous solution to fabricate a positively-charged NF membrane with tunable performance. As the molecular structures of TAEA and PIP are totally different, the chemical composition and structure of the polyamine selective layer could be tailored via varying the PIP content. The resulting optimal membrane exhibited an excellent water permeability of 10.2 LMH bar−1 and a high rejection of MgCl2 (92.4%), due to the incorporation of TAEA/PIP. In addition, this TAEA NF membrane has a superior long-term stability. Thus, this work provides a facile way to prepare a positively charged membrane with an efficient water softening ability.

Osmotic adaptation of renal medullary cells during transition from chronic diuresis to antidiuresis

1993 ◽  
Vol 264 (4) ◽  
pp. F722-F729 ◽  
Author(s):  
M. Sone ◽  
G. J. Albrecht ◽  
A. Dorge ◽  
K. Thurau ◽  
F. X. Beck
Keyword(s):  
Amino Acids ◽  
High Performance ◽  
Renal Medulla ◽  
Organic Osmolytes ◽  
Osmotic Adaptation ◽  
High Concentrations ◽  
Amino Acid Contents ◽  
Tissue Contents ◽  
Abrupt Rise

The cells of the renal medulla adapt osmotically to high extracellular tonicities by high concentrations of organic osmolytes. Intracellular accumulation of these substances is, however, relatively slow. The aim of the present study was to assess the effect of an abrupt rise in extracellular tonicity on intracellular osmotically active substances after prior reduction of medullary contents of organic osmolytes by chronic diuresis. Intra- and extracellular electrolyte concentrations at the papillary tip and the tissue contents of methylamines (glycerophosphorylcholine, betaine), polyols (myo-inositol, sorbitol), and several amino acids were determined in the different kidney zones by electron microprobe analysis and high-performance liquid chromatography in control animals, in rats infused for 6 days with furosemide via osmotic minipumps, and in rats given the vasopressin analogue [deamino-Cys1,D-Arg8]vasopressin (DDAVP) after the chronic furosemide treatment. Chronic diuresis greatly reduced interstitial tonicity and inner medullary contents of methylamines and polyols and moderately reduced inner medullary amino acid contents but did not significantly affect intracellular electrolyte concentrations. When the diuretic rats were infused with DDAVP for 2 h, interstitial tonicity more than doubled and intracellular K and Cl concentrations rose by approximately 60 and 160%, while inner medullary contents of methylamines, polyols, and amino acids were not changed significantly. These data demonstrate that after effective depletion of medullary organic osmolytes by long-term diuresis, the cells of the renal papilla adapt osmotically to an abrupt increase in extracellular tonicities by elevated cell electrolyte concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Plasma Metabolic Signature and Abnormalities in HIV-Infected Individuals on Long-Term Successful Antiretroviral Therapy

Metabolites ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 210 ◽  
Author(s):  
Hemalatha Babu ◽  
Maike Sperk ◽  
Anoop T. Ambikan ◽  
Gladys Rachel ◽  
Vinod Kumar Viswanathan ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Amino Acids ◽  
Antiretroviral Therapy ◽  
High Performance ◽  
Neurological Diseases ◽  
Aromatic Amino Acids ◽  
Essential Amino Acids ◽  
Metabolic Abnormalities ◽  
Plasma Proteomics

Targeted metabolomics studies reported metabolic abnormalities in both treated and untreated people living with human immunodeficiency virus (HIV) (PLHIV). The present study aimed to understand the plasma metabolomic changes and predicted the risk of accelerated aging in PLHIV on long-term suppressive antiretroviral therapy (ART) in a case-control study setting and its association with the plasma proteomics biomarkers of inflammation and neurological defects. Plasma samples were obtained from PLHIV on successful long-term ART for more than five years (n = 22) and matched HIV-negative healthy individuals (n = 22, HC herein). Untargeted metabolite profiling was carried out using ultra-high-performance liquid chromatography/mass spectrometry/mass spectrometry (UHPLC/MS/MS). Plasma proteomics profiling was performed using proximity extension assay targeting 184 plasma proteins. A total of 250 metabolites differed significantly (p < 0.05, q < 0.1) between PLHIV and HC. Plasma levels of several essential amino acids except for histidine, branched-chain amino acids, and aromatic amino acids (phenylalanine, tyrosine, tryptophan) were significantly lower in PLHIV compared to HC. Machine-learning prediction of metabolite changes indicated a higher risk of inflammatory and neurological diseases in PLHIV. Metabolic abnormalities were observed in amino-acid levels, energetics, and phospholipids and complex lipids, which may reflect known differences in lipoprotein levels in PLHIV that can resemble metabolic syndrome (MetS).

Recommendations for Long-Term Operation of High-Performance Submersible Motor Pumps in Mine Dewatering

2020 ◽  
Author(s):  
David Beck ◽  
Sebastian Wulff ◽  
Paul Uwe Thamsen ◽  
Morris Reich ◽  
Jean Pierre Worringer
Keyword(s):  
High Performance ◽  
Initial Conditions ◽  
Mining Industry ◽  
Open Pit ◽  
Open Pit Mining ◽  
Short Term ◽  
Term Operation ◽  
Deep Wells ◽  
Submersible Motor

Abstract Modern submersible pumps are high performance aggregates for long-term operation, which find application in open-pit mining. Dewatering of groundwater to run an open-pit mine with various conditions for submersible pumps often leads to short-term performance based on different circumstances in the well as well as in the general operation. These result in high maintenance and energy costs and decreases the drawdown in open-pit mining. To ensure a long-time performance, a proper selection of submersible pump and motor is required. It is also necessary to consider the geometry of different deep wells in order to take into account the initial conditions of the pumps. This paper shows recommendations for long-term operation of high-performance submersible pumps due to the conditions of the mining industry. Therefore, a holistic consideration of the aggregate takes place to receive recommendations, which minimize the rate of pump failures and increase the efficiency of the dewatering process. These recommendations are based on various failures found during an investigation. Furthermore, this paper recommends different methods to prevent these failures, for instance clogging and erosion through particles in the well. These recommendations are linked to the research of different submersible motor pumps from various manufacturers in different wells in German open-pit mines with short-term operation caused by several circumstances.

scholarly journals Identifying high performance and durable methylammonium-free lead halide perovskites through high throughput synthesis and characterization

2021 ◽  
Author(s):  
Yu An ◽  
Carlo Andrea Riccardo Perini ◽  
Juanita Hidalgo ◽  
Andrés-Felipe Castro-Méndez ◽  
Vagott Jacob N. ◽  
...  
Keyword(s):  
Solar Cells ◽  
High Performance ◽  
Tolerance Factor ◽  
Structure Property ◽  
Term Operation ◽  
Wide Range ◽  
Holistic Understanding ◽  
Compositional Space ◽  
Tolerance Factors

One of the organic component in the perovskite photo-absorber, the methylammonium cation, has been suggested to be a roadblock to long-term operation of organic-inorganic hybrid perovskite-based solar cells. Methylammonium-free perovskites thus represent a possible direction for more stable photo-absorbers that are also compatible with multijunction solar cells. However, most work on methylammonium-free perovskites involves cesium and formamidinium as the A-site cations, which are thermodynamically less stable than the methylammonium-based materials. In this work we systematically explore the crystallographic and optical properties of the compositional space of mixed cation and mixed halide lead perovskites, where formamidinium (FA+) is gradually replaced by cesium (Cs+), and iodide (I-) is substituted by bromide (Br-), i.e., CsyFA1–yPb(BrxI1–x)3. The crystal phases, which could be tuned by changing the tolerance factor for mixed perovskite alloys, are qualitatively determined and the composition–structure relationship is established in the CsyFA1–yPb(BrxI1–x)3 compositional space. We find that higher tolerance factors lead to more cubic structures, whereas lower tolerance factors lead to more orthorhombic. We also find that while some correlation exists between tolerance factor and structure, tolerance factor does not provide a holistic understanding of whether a perovskite structure will fully form. Given the wide range of bandgaps produced by this compositional space, an empirical expression is devised to predict the optical bandgap of CsyFA1–yPb(BrxI1–x)3 perovskites – which changes as a function of composition –, conducive to the design of absorbers with bandgaps tailor-made for specific tandem and single-junction applications. By screening 26 solar cells with different compositions, we find that Cs1/6FA5/6PbI3 delivers the highest efficiency and long-term stability among I-rich compositions. This work sheds light on the fundamental structure-property relationships in the CsyFA1–yPb(BrxI1–x)3 compositional space, providing vital insight to the design of durable perovskite materials. Our approach provides a library of structural and optoelectronic information of this compositional space.

High performance boron removal from seawater by two-pass SWRO system with different membranes

2010 ◽  
Vol 10 (3) ◽  
pp. 327-336 ◽  
Author(s):  
Jia Xu ◽  
Xueli Gao ◽  
Guohua Chen ◽  
Linda Zou ◽  
Congjie Gao
Keyword(s):  
High Performance ◽  
Boron Concentration ◽  
Jiaozhou Bay ◽  
The Yellow Sea ◽  
World Health ◽  
Permeate Flux ◽  
Boron Removal ◽  
Term Operation ◽  
The Impact

Boron in the desalinated water produced by the seawater reverse osmosis (SWRO) system is one of the most challenging issues for drinking or irrigation water uses. In recent years, many post-treatment methods and designs for boron elimination have emerged and attracted lots of attention, but only a few cases have demonstrated high performance and economic efficiency. The main aim of this work was to evaluate the efficiency of boron removal from seawater using a two-pass SWRO system employing different RO membranes at Qingdao Jiaozhou Bay, the Yellow Sea of China. In this study, HYDRANAUTICS SWC3+ and ESPAB were chosen as the first and second pass membrane, respectively. The impact of feed properties including temperature, pH, salinity, boron concentration, and operational conditions such as feed pressure on boron rejection and permeate flux was determined. In addition, a relative long term run of the two-pass SWRO system was investigated and compared with performance of system that uses Filmtec membrane as reported in the literature. Although the pilot system in this study experienced more severe feed conditions with lower pH, higher feed boron concentrations and lower operational pressures: all potential negative factors for boron rejection, it still achieved good performance for boron reduction. The results of three-month long term operation indicated that, at optimum conditions, two-pass SWRO system at Qingdao Jiaozhou Bay achieved a high performance and stability without anti-scalants to produce permeate which has much a lower boron concentration than the World Health Organization (WHO) guideline.

scholarly journals Identifying high performance and durable methylammonium-free lead halide perovskites through high throughput synthesis and characterization

2021 ◽  
Author(s):  
Yu An ◽  
Andres Castro ◽  
Ruipeng Li ◽  
Juanita Hidalgo ◽  
Carlo Perini ◽  
...  
Keyword(s):  
Solar Cells ◽  
High Throughput ◽  
High Performance ◽  
Synthesis And Characterization ◽  
Inorganic Hybrid ◽  
Term Operation ◽  
Hybrid Perovskite ◽  
Halide Perovskites ◽  
Lead Halide

One of the organic components in the perovskite photo-absorber, the methylammonium cation, has been suggested to be a roadblock to long-term operation of organic-inorganic hybrid perovskite-based solar cells. In this...

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