The Yichun Ta-Sn-Li Deposit, South China: Evidence for Extreme Chemical Fractionation in F-Li-P-Rich Magma

2020 ◽  
Author(s):  
Peter J. Pollard
Keyword(s):  
Boundary Layer ◽  
Thin Sheet ◽  
Chemical Fractionation ◽  
Igneous Complex ◽  
Rayleigh Fractionation ◽  
Low Viscosity ◽  
Incompatible Elements ◽  
Growth Zones ◽  
High Concentrations ◽  
Very High

Abstract The Yichun Ta-Sn-Li deposit occurs within the 9.5-km2 Yashan Igneous Complex, which is made up of felsic, peraluminous intrusions including two-mica, Li-mica, and topaz-lepidolite granites. The topaz-lepidolite granite forms a thin sheet confined to the upper part of the Li-mica granite and is separated from the host metasediments by a marginal pegmatite. The topaz-lepidolite granite is characterized by the presence of snowball textures in which quartz, K-feldspar, and topaz phenocrysts contain albite laths and rare lepidolite and columbite arranged along growth zones. These textures indicate simultaneous crystallization of these phases and attest to the subsolvus character of the topaz-lepidolite granite. Minor and accessory phases in the topaz-lepidolite granite include amblygonite, cassiterite, columbite-tantalite, microlite, wodginite, zircon, monazite, and pollucite. The topaz-lepidolite granite is characterized by low SiO2 (68.6–69.7 wt %), TiO2 (0.01 wt %), Fe2O3(total) (0.15–0.33 wt %), MgO (0.01–0.05 wt %), and CaO (0.15–0.19 wt %), whereas Al2O3 (17.97–18.26 wt %), Li2O (0.90–2.09 wt %), P2O5 (0.43–0.54 wt %), and F (1.09–2.30 wt %) are all very high. Na2O ≫ K2O due to both high Na2O (5.18–6.30 wt %) and low K2O (2.63–3.05 wt %). The topaz-lepidolite granite contains extremely high concentrations of Rb (>3,300 ppm), Cs (>340 ppm), Sn (>140 ppm), and Ta (>120 ppm), with very low Zr/Hf and Nb/Ta. Gaps of >3.5 wt % SiO2 and >2.5 wt % Al2O3 together with large increases in F, Li2O, and P2O5 between the Li-mica and topaz-lepidolite granites are not compatible with an evolution by Rayleigh fractionation processes. It is proposed instead that early crystallization of the Li-mica granite led to the formation of an Si-poor, Al-, Na-, and flux-rich boundary layer whose low viscosity and density allowed effective separation from the remaining melt and crystals. This melt concentrated incompatible elements including tin and tantalum and accumulated in the upper part of the magma chamber where it crystallized the sheet-like bodies of marginal pegmatite and topaz-lepidolite granite. The uppermost part of the topaz-lepidolite granite consists of aplite and overlying quartz lepidolite rock, which is composed mainly of quartz, lepidolite, albite, K-feldspar, topaz, amblygonite, cassiterite, and columbite. Compared to the topaz-lepidolite granite the aplite and quartz-lepidolite rock shows a number of complementary element enrichments and depletions. The quartz-lepidolite rock is enriched in Fe, Mn, K, Rb, Cs, Li, F, Ba, Sr, Ti, Zr, Nb, W, Th, and Sm. The formation of the quartz-lepidolite rock is interpreted to result from separation of an F- and Li-rich alkaline phase, which accumulated beneath the already crystallized marginal pegmatite. Complementary to this was crystallization of the strongly peraluminous sodic aplite with the highest tantalum contents measured in this study.

The metachor as a characteristic of the association of electrolytes in aqueous solutions

1984 ◽  
Vol 49 (5) ◽  
pp. 1061-1078 ◽  
Author(s):  
Jiří Čeleda ◽  
Stanislav Škramovský
Keyword(s):  
Aqueous Solutions ◽  
Apparent Volume ◽  
Solutions Of Electrolytes ◽  
Molal Volumes ◽  
The Difference ◽  
High Concentrations ◽  
Experimental Values ◽  
Suitable Characteristic ◽  
Association Of Ions ◽  
Very High

Based on the earlier paper introducing a concept of the apparent parachor of a solute in the solution, we have eliminated in the present work algebraically the effect which is introduced into this quantity by the additivity of the apparent molal volumes. The difference remaining from the apparent parachor after substracting the contribution corresponding to the apparent volume ( for which the present authors suggest the name metachor) was evaluated from the experimental values of the surface tension of aqueous solutions for a set of 1,1-, 1,2- and 2,1-valent electrolytes. This difference showed to be independent of concentration up to the very high values of the order of units mol dm-3 but it was directly proportional to the number of the free charges (with a proportionality factor 5 ± 1 cm3 mol-1 identical for all studied electrolytes). The metachor can be, for this reason, a suitable characteristic for detection of the association of ions and formation of complexes in the solutions of electrolytes, up to high concentrations where other methods are failing.

scholarly journals Nitrification Process in a Nuclear Wastewater with High Load of Nitrogen, Uranium and Organic Matter under ORP Controlled

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1607
Author(s):  
Mariano Venturini ◽  
Ariana Rossen ◽  
Patricia Silva Paulo
Keyword(s):  
Ammonia Oxidation ◽  
High Load ◽  
Nuclear Fuels ◽  
Monod Model ◽  
Nernst Equation ◽  
Nitrification Process ◽  
Real Wastewater ◽  
High Concentrations ◽  
Wastewater Samples ◽  
Very High

To produce nuclear fuels, it is necessary to convert uranium′s ore into UO2-ceramic grade, using several quantities of kerosene, methanol, nitric acid, ammonia, and, in low level, tributyl phosphate (TBP). Thus, the effluent generated by nuclear industries is one of the most toxic since it contains high concentrations of dangerous compounds. This paper explores biological parameters on real nuclear wastewater by the Monod model in an ORP controlled predicting the specific ammonia oxidation. Thermodynamic parameters were established using the Nernst equation to monitor Oxiders/Reductors relationship to obtain a correlation of these parameters to controlling and monitoring; that would allow technical operators to have better control of the nitrification process. The real nuclear effluent is formed by a mixture of two different lines of discharges, one composed of a high load of nitrogen, around 11,000 mg/L (N-NH4+-N-NO3−) and 600 mg/L Uranium, a second one, proceeds from uranium purification, containing TBP and COD that have to be removed. Bioprocesses were operated on real wastewater samples over 120 days under controlled ORP, as described by Nernst equations, which proved to be a robust tool to operate nitrification for larger periods with a very high load of nitrogen, uranium, and COD.

scholarly journals Halogenated Volatile Organic Compounds in Water Samples and Inorganic Elements Levels in Ores for Characterizing a High Anthropogenic Polluted Area in the Northern Latium Region (Italy)

2021 ◽  
Vol 18 (4) ◽  
pp. 1628
Author(s):  
Mario Vincenzo Russo ◽  
Ivan Notardonato ◽  
Alberto Rosada ◽  
Giuseppe Ianiri ◽  
Pasquale Avino
Keyword(s):  
Organic Compounds ◽  
Mean Value ◽  
Greenhouse Crops ◽  
River Waters ◽  
Liquid Liquid Extraction ◽  
Volatile Organic ◽  
High Concentrations ◽  
Very High ◽  
Inorganic Fraction

This paper shows a characterization of the organic and inorganic fraction of river waters (Tiber and Marta) and ores/soil samples collected in the Northern Latium region of Italy for evaluating the anthropogenic/natural source contribution to the environmental pollution of this area. For organic compounds, organochloride volatile compounds in Tiber and Marta rivers were analyzed by two different clean-up methods (i.e., liquid–liquid extraction and static headspace) followed by gas chromatography–electron capture detector (GC-ECD) analysis. The results show very high concentrations of bromoform (up to 1.82 and 3.2 µg L−1 in Tiber and Marta rivers, respectively), due to the presence of greenhouse crops, and of chloroform and tetrachloroethene, due to the presence of handicrafts installations. For the qualitative and quantitative assessment of the inorganic fraction, it is highlighted the use of a nuclear analytical method, instrumental neutron activation analysis, which allows having more information as possible from the sample without performing any chemical-physical pretreatment. The results have evidenced high levels of mercury (mean value 88.6 µg g−1), antimony (77.7 µg g−1), strontium (12,039 µg g−1) and zinc (103 µg g−1), whereas rare earth elements show levels similar to the literature data. Particular consideration is drawn for arsenic (414 µg g−1): the levels found in this paper (ranging between 1 and 5100 µg g−1) explain the high content of such element (as arsenates) in the aquifer, a big issue in this area.

THE SELECTIVE PROTEOLYTIC ENZYME INHIBITORY ACTION OF BENZETHONIUM CHLORIDE

1960 ◽  
Vol 38 (1) ◽  
pp. 25-32 ◽  
Author(s):  
Ivan T. Beck ◽  
E. Pinter ◽  
R. D. McKenna ◽  
H. Griff
Keyword(s):  
Subcutaneous Injection ◽  
Proteolytic Enzyme ◽  
Inhibitory Action ◽  
Hemorrhagic Pancreatitis ◽  
Benzethonium Chloride ◽  
Tryptic Activity ◽  
High Concentrations ◽  
Acute Hemorrhagic Pancreatitis ◽  
Very High

Acute hemorrhagic pancreatitis in humans is thought to be perpetuated by the autolytic processes catalyzed by trypsin and lipase. This study is an integral part of our search for trypsin and lipase inhibitors to be used in the treatment of this disease.Benzethonium chloride was found to inhibit tryptic activity in vitro. The proteolytic activity of rabbit's serum was inhibited, and the inhibition was most pronounced 6 to 12 hours after the subcutaneous injection of the compound. Fibrinolysin was also inhibited in vitro but benzethonium chloride had no inhibitory action on chymotrypsin, pepsin, or lipase.Serum proteins in vitro were precipitated only with very high concentrations of the compound. No significant protein changes were observed in sera of rabbits after the subcutaneous injection of the compound.

Design and Analysis of a High Pitch to Chord Ratio Cascade Representative of Ducted Propfans

1991 ◽  
Author(s):  
A. Weber ◽  
W. Steinert ◽  
H. Starken
Keyword(s):  
Boundary Layer ◽  
Mach Number ◽  
High Efficiency ◽  
Pressure Ratio ◽  
Flow Analysis ◽  
High Pitch ◽  
Integral Boundary ◽  
Pressure Loss Coefficient ◽  
Distribution Boundary ◽  
Very High

Efforts to reduce the specific fuel consumption of a modern aero engine focus in particular on increasing the by-pass ratio beyond the current level of around 5. One concept is the counterrotating shrouded propfan operating at low overall pressure ratio and having only very few fan blades of extremely high pitch/chord ratios. The relative inlet Mach numbers cover a range from 0.7 at the hub to 1.1 at the tip section of the first rotor. A propfan cascade was designed by taking into account two characteristic features of a propfan blade-blade section: • a very high pitch/chord ratio of s/c = 2.25 • an inlet Mach number of M1 = 0.90 which leads to transonic flow conditions inside the blade passage In the design process a profile generator and a quasi-3D Euler solver were used iteratively to optimize the profile Mach number distribution. Boundary layer behavior was checked with an integral boundary layer code. The cascade design was verified experimentally in the transonic cascade wind tunnel of DLR at Cologne. The extensive experimental results confirm the design goal of roughly 5 degree flow turning. A total pressure loss coefficient of less than 1.5% was measured at design conditions. This validates the very high efficiency level the propfan concept is calling for. A 2D Navier-Stokes flow analysis code yields good results in comparison to the experimental ones.

scholarly journals Arginine Inhibits Serpins

2007 ◽  
Vol 13 (2) ◽  
pp. 213-218
Author(s):  
Thomas W. Stief
Keyword(s):  
Esterase Activity ◽  
Serine Proteases ◽  
Biological Fluid ◽  
Microtiter Plate ◽  
Human Albumin ◽  
Amidolytic Activity ◽  
Peptide Substrates ◽  
Plate Reader ◽  
High Concentrations ◽  
Very High

Serine protease inactivators (serpins) are important regulators in biochemistry. Often it is necessary to block the serpin action, that is, to stabilize the sample. The guanidine group of arginine is the ligand for the active center pocket of many serine proteases. Arginine or guanidine inhibits serine proteases, and arginine belongs to the reactive P1-P1' center of many serpins. The plasmatic antithrombin, antiplasmin, or anti-C1-esterase activity was determined: A total of 20 µL of pooled normal plasma or 7% human albumin was added to 100 µL of 0—2.67 M arginine, pH 8.6, 10 µL of 26 mIU/mL thrombin in 7% human albumin, and 30 µL of 1.7 mM CHG-Ala-Arg-pNA (37°C). ΔA at 405 nm was determined, by using a microtiter plate reader. Thrombin was substituted by plasmin or C1-esterase, and the chromogenic peptide substrates <Glu-Phe-Lys-pNA or MeOC-Lys(eCBO)-Gly-Arg-pNA, respectively, were used. The IC50 of arginine against plasmatic antithrombin activity is 580 mM; the IC 25 is 440 mM. The IC25 of arginine against plasmatic α 2-antiplasmin or C1-inactivator is 1650 mM. The amidolytic activity of thrombin, plasmin, and C1-esterase is inhibited similarly by arginine: the IC50 for arginine against the amidolytic activity of these proteases is about 400 mM. Arginine at very high concentrations inhibits serpins. This is important, if stabilization of a biological fluid is a prerequisite for valid activities of serine proteases. In addition, these high concentrations of arginine might be a new gentle principle to inhibit pathogens that need serpins for their pathophysiology.

scholarly journals Vitamin B12 transport in blood. I. Congenital deficiency of transcobalamin II

Blood ◽  
1975 ◽  
Vol 45 (1) ◽  
pp. 71-82 ◽  
Author(s):  
E Gimpert ◽  
M Jakob ◽  
WH Hitzig
Keyword(s):  
Vitamin B12 ◽  
Binding Capacity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Congenital Deficiency ◽  
Complete Clinical Remission ◽  
High Concentrations ◽  
High Doses ◽  
Vitamin B12 Binder ◽  
Very High ◽  
Transcobalamin Ii

Abstract Some characteristics of vitamin B12 binding and transport in the serum of an infant with congenital hereditary transcobalamin II (TC II) deficiency were studied using the following parameters and methods: vitamin B12 level and binding capacity; electrophoretic mobility in polyacrylamide gel electrophoresis; various immunodiffusion and absorption experiments, using a specific anti-TC II antiserum and the patient's serum as antigen. The results of these studies point to a deficient synthesis of TC II. Parenteral administration of high doses of vitamin B12 was followed by rapid and complete clinical remission and the appearance of vitamin B12 binder in the alpha 2 region which is similar to “fetal binder.” Thus, very high concentrations of vitamin B12, either carrier free or bound to this alpha 2 binder, were able to correct the disturbed physiology of TC II deficiency, presumably by normalization of DNA-thymine synthesis.

scholarly journals Observations of air composition in Brazil between the Equator and 20°s during the dry season.

1985 ◽  
Vol 15 (1-2) ◽  
pp. 77-120 ◽  
Author(s):  
P.J. Crutzen ◽  
M.T. Coffey ◽  
A.C. Delany ◽  
J. Greenberg ◽  
P. Haagenson ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Carbon Monoxide ◽  
Tropical Forests ◽  
Air Pollutants ◽  
Trace Gases ◽  
Dry Season ◽  
Photochemical Reactions ◽  
Ozone Concentrations ◽  
Air Chemistry ◽  
High Concentrations

Field measurement programs in Brazil during the dry season months of August and September in 1979 and 1980 have demonstrated the great importance of the continental tropics in global air chemistry. Especially in the mixed layer, the air composition over land is much different from that over the ocean and the land areas are clearly longe scale sources of many inportant trace gases. During the dry season much biomass, burning takes place especially in the cerrado regions leading to substantial emission of air pollutants, such as CO, NOx, N2O, CH4 and other hydrocarbons. Ozone concentrations are alsoenhanced due to photochemical reactions. Biogenic organic emissions from tropical forests play likewise an important role in the photochemistry of the atmosphere. Carbon monoxide was found to be present in high concentrations in the boundary layer of the tropical forest, but ozone concentrations were much lower than in the cerrado.

scholarly journals Environmental Performances and Biological Toxicity of Snowpack Water

2019 ◽  
Vol 9 (1) ◽  
pp. 4967-4971
Keyword(s):  
Reference Class ◽  
Biological Toxicity ◽  
Snow Covered Area ◽  
Covered Area ◽  
Sampling Points ◽  
Class 1 ◽  
High Concentrations ◽  
Medium Toxicity ◽  
Very High ◽  
Snow Samples

This work analyzes the state of snowpack in Nizhny Novgorod on the basis of certain chemical performances and integral biological toxicity. Snow samples were obtained in February 2018 along major highways of Nizhny Novgorod. A snow-covered area in Dubrava forestry was selected as reference. The studies demonstrated that the snowpack was characterized by very high concentrations of chlorides and sulfides: in sampling points of the Lower City, the content of chlorides and sulfates varied in the ranges of 24.67–62.36 mg/l and 30.16–62.09 mg/l, respectively, and in sampling points of the Upper City, this variability was 416.82–988.45 mg/l and 280.11–879.22 mg/l, respectively. The content of lead in snowpack in both the Lower City and the Upper City was approximately the same (0.0053 and 0.0048 mg/l). The minimum content of pollutants in snow samples from reference site was characterized by toxicity (10%, V = 6.0%) which was estimated as allowable (toxicity class 1). Snowpack water from the Lower City was characterized generally by medium toxicity (class 2), and sampled in the Upper City – by acute toxicity (59%, V = 26.5%), with regard to the reference (class 3).

scholarly journals Soil quality and proposal for fertility improvement of arable soil in Rasina District

2021 ◽  
Vol 26 (51) ◽  
pp. 27-32
Author(s):  
Biljana Sikirić ◽  
Vesna Mrvić ◽  
Olivera Stajković-Srbinović ◽  
Vladan Ugrenović ◽  
Darko Jaramaz ◽  
...  
Keyword(s):  
Soil Fertility ◽  
Sandy Loam ◽  
Absorption Capacity ◽  
Available Phosphorus ◽  
Clay Loam ◽  
Regular Control ◽  
Exchangeable Ca ◽  
High Concentrations ◽  
Field Plots ◽  
Very High

During the regular control of soil fertility in the Rasina District, it was established that the plots of land were distributed across Vertisol, Eutric Cambisol and Fluvisol types of soils, and to a lesser extent on Pseudogley and Ranker. The tested samples had different textures - sandy loam and loam, clay-sandy loam and clay loam, and clay. Plots of land that were of very acidic and acidic reactions were predominant, with medium amounts of humus, very low amounts of available phosphorus, and high amounts of available potassium. High or very high cation absorption capacity was found in about half of the examined fields; a deficient content of exchangeable Ca was recorded in 22% of plots and that of exchangeable Mg in 16% of plots, while an unfavorable Ca/Mg ratio was measured in 44% of plots. The overall sensitivity to acidification was mainly moderate (50.6% of plots) and strong (20.2% of plots). Very high concentrations of mobile Al, which could be toxic to plants, were found in 5 field plots.

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