The origin of the hydrous scandium phosphate, kolbeckite, from the Hagendorf-Pleystein pegmatite province, Germany

AbstractThe rare hydrous scandium phosphate, kolbeckite, [Sc(PO4).2H2O], has been recognized for the first time from the Hagendorf-Pleystein pegmatite province. The mineral was formed by the alteration of quartz-rich relict cores of pegmatites containing rutile, ilmenite, columbite, pyrochlore, wolframite, monazite and apatite. The alteration process involved acidic meteoric water and was not related to low-temperature hydrothermal fluids. Scandium and phosphorous for the formation of the kolbeckite were provided by the decomposition of the primary oxides and phosphates, respectively. Hydrous Sc phosphates are considered to form only during advanced stages of weathering in Al- and Fe-poor environments. In Al- and Fe-rich environments Sc is scavenged from solution as a trace component of Al- and Fe phosphates. A special type of leucoxene containing Fe, Al and P was formed during the process of formation of kolbeckite. In the absence of phosphate anions, Sc is removed in solution and ‘normal’ leucoxene is formed.

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Palladium-oxygenated compounds of the Gongo Soco mine, Quadrilátero Ferrífero, central Minas Gerais, Brazil

Mineralogical Magazine ◽

10.1180/002646101550208 ◽

2001 ◽

Vol 65 (2) ◽

pp. 169-179 ◽

Cited By ~ 11

Author(s):

A. Raphael Cabral ◽

B. Lehmann ◽

R. Kwitko ◽

R. D. Jones ◽

F. R. M. Pires ◽

...

Keyword(s):

Low Temperature ◽

Shear Band ◽

Iron Ore ◽

Minas Gerais ◽

Hydrothermal Fluids ◽

Oxygenated Compounds ◽

Quadrilátero Ferrífero ◽

Fe And Mn ◽

First Time

AbstractNew data on the Gongo Soco palladium-oxygenated compounds are presented for the first time since the work of Johnson and Lampadius (1837). A variety of PdO species is documented, always in association with Cu, Fe and Mn, and includes Pd(OH)2or PdO.H2O, and phases with metal excess in relation to oxygen, interpreted as metastable. Their remarkable occurrence in ‘ouro preto’ (black gold) and jacutinga (auriferous itabirite/iron ore) is the result of mertieite-II alteration. It involves leaching of Sb and As, limited removal of Pd, and incorporation of Cu, Mn and Hg into PdO species. The locus of Hg-bearing PdO species in microfractures parallel to the enclosing gold-mineralized shear band suggests at least one low-temperature hydrothermal generation. The presence of a halite crystal attached to gold testifies to the involvement of Cl-saturated hydrothermal fluids in the oxidizing environment of jacutinga formation.

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THE GENETIC HYPOTHESIS OF THE URANIFERUS MINERALIZATION, EASTERN CHALKIDIKI (NORTHERN GREECE)

Bulletin of the Geological Society of Greece ◽

10.12681/bgsg.11676 ◽

2017 ◽

Vol 43 (5) ◽

pp. 2692

Author(s):

D. Persianis ◽

J. Katsikis ◽

D.E. Karageorgiou

Keyword(s):

Low Temperature ◽

Hydrothermal System ◽

Meteoric Water ◽

Wall Rock ◽

Uranium Mineralization ◽

Hydrothermal Fluids ◽

Northern Greece ◽

Possible Cause ◽

Rock Minerals ◽

Genetic Hypothesis

This paper presents the genetic hypothesis of αn uranium mineralization observed in Eastern Chalkidiki-Greece. In the area of Stratoni (location Asprochomata) a uranium mineralization is expressing by disseminated primary (orthobrannerite) and secondary (torbernite) U minerals, in the granodioritic body of this area. Genetically it may be the result of uranium redistribution, which occurs in the resisting accecory minerals (e.g monazite) of the granodiorite, by magmatic or meteoric hydrothermal fluids of low temperature. The mineralized granodiorite of Stratoni gives no evidence of a metalliferous pluton, based on the study of hydrothermally altered samples and this ascertainment is a fact that should be confronted with a lot of carefull thought. In the granite of Arnea area, uranium mineralization is in generally absent, excluding some poor one’s, located along the contacts of the granite with small remnants of the hosting rock, expressed in the form of impregnations or veinlets. The possible cause for its formation being the interaction of a secondary low temperature hydrothermal system mainly of meteoric water participation (convective hydrothermal system) with the granite and the hosting wall-rock minerals. The granite of Arnea indicates all the characteristics of a metalliferous granitoid.

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Transformation behavior of yttria stabilized tetragonal zirconia polycrystal–TiB2 composites

Journal of Materials Research ◽

10.1557/jmr.2001.0294 ◽

2001 ◽

Vol 16 (7) ◽

pp. 2158-2169 ◽

Cited By ~ 21

Author(s):

B. Basu ◽

J. Vleugels ◽

O. Van Der Biest

Keyword(s):

Thermal Expansion ◽

Phase Transformation ◽

Low Temperature ◽

Tetragonal Zirconia ◽

Mechanical Analysis ◽

Transformation Behavior ◽

Thermal Expansion Data ◽

Thermally Induced ◽

First Time ◽

Tetragonal Zirconia Polycrystal

The objective of the present article is to study the influence of TiB2 addition on the transformation behavior of yttria stabilized tetragonal zirconia polycrystals (Y-TZP). A range of TZP(Y)–TiB2 composites with different zirconia starting powder grades and TiB2 phase contents (up to 50 vol%) were processed by the hot-pressing route. Thermal expansion data, as obtained by thermo-mechanical analysis were used to assess the ZrO2 phase transformation in the composites. The thermal expansion hysteresis of the transformable ceramics provides information concerning the transformation behavior in the temperature range of the martensitic transformation and the low-temperature degradation. Furthermore, the transformation behavior and susceptibility to low-temperature degradation during thermal cycling were characterized in terms of the overall amount and distribution of the yttria stabilizer, zirconia grain size, possible dissolution of TiB2 phase, and the amount of residual stress generated in the Y-TZP matrix due to the addition of titanium diboride particles. For the first time, it is demonstrated in the present work that the thermally induced phase transformation of tetragonal zirconia in the Y-TZP composites can be controlled by the intentional addition of the monoclinic zirconia particles into the 3Y-TZP matrix.

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CO2 hydrogenation into CH4 over Ni–Fe catalysts

Functional Materials Letters ◽

10.1142/s1793604718500571 ◽

2018 ◽

Vol 11 (03) ◽

pp. 1850057 ◽

Cited By ~ 8

Author(s):

Reza Meshkini Far ◽

Olena V. Ischenko ◽

Alla G. Dyachenko ◽

Oleksandr Bieda ◽

Snezhana V. Gaidai ◽

...

Keyword(s):

Low Temperature ◽

Synergistic Effect ◽

Atmospheric Pressure ◽

High Efficiency ◽

Co2 Hydrogenation ◽

Hydrogenation Catalysts ◽

Fe Catalysts ◽

First Time ◽

Supported Ni ◽

Hydrogenation Of Co

Here, we report, for the first time, on the catalytic hydrogenation of CO2 to methane at atmospheric pressure. For the preparation of hydrogenation catalysts based on Ni and Fe metals, a convenient method is developed. According to this method, low-temperature reduction of the co-precipitated Ni and Fe oxides with hydrogen gives the effective and selective bimetallic Ni[Formula: see text]Fe[Formula: see text], Ni[Formula: see text]Fe[Formula: see text] and Ni[Formula: see text]Fe[Formula: see text] catalysts. At the temperature range of 300–400[Formula: see text]C, they exhibit a high efficiency of CH4 production with respect to monometallic Ni and Fe catalysts. The results imply a synergistic effect between Ni and Fe which caused the superior activity of the Ni[Formula: see text]Fe[Formula: see text] catalyst conversing [Formula: see text]% of CO2 into CH4 at 350[Formula: see text]C. To adapt the Ni–Fe catalysts in the industry, the effect of two different carriers on the efficiency of the alumina-supported Ni[Formula: see text]Fe[Formula: see text] catalyst was investigated. It is found that the Ni[Formula: see text]Fe[Formula: see text]/[Formula: see text]-Al2O3 catalyst effectively conversed CO2 giving 100% methane yield already at 275[Formula: see text]C.

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Interrupted crosstalk between natural killer cells and anti-epidermal growth factor receptor: a possible role in hepatocellular carcinoma treatment failure

Current Cancer Drug Targets ◽

10.2174/1568009621666210519105203 ◽

2021 ◽

Vol 21 ◽

Author(s):

Hadeer Abosalema ◽

Shahenda Mahgoub ◽

Mohamed Emara ◽

Nahla Kotb ◽

Sameh Soror

Keyword(s):

Hepatocellular Carcinoma ◽

Epidermal Growth Factor Receptor ◽

Growth Factor ◽

Epidermal Growth Factor ◽

Growth Factor Receptor ◽

Major Health Problem ◽

Advanced Stages ◽

Epidermal Growth ◽

First Time ◽

Late Stages

: Hepatocellular carcinoma (HCC) is a major health problem worldwide. Most patients are diagnosed for the first time at late stages; this leads to a very poor prognosis. It is challenging to discover strategies for treatment at these advanced stages. Recently, monoclonal antibodies (mAbs) targeting specific cellular signaling pathways in HCC have been developed. Unfortunately, they still have a low survival rate, and some of them failed clinically to produce effective responses even if they showed very good results against HCC in preclinical studies. This review focuses on and discusses the possible causes for the failure of mAbs, precisely anti-Epidermal Growth Factor Receptor (EGFR) mAb and the crosstalk between this mAb and patients' NK cells.

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Gold in Irish Coal: Palaeo-Concentration from Metalliferous Groundwaters

Minerals ◽

10.3390/min10070635 ◽

2020 ◽

Vol 10 (7) ◽

pp. 635

Author(s):

Liam A. Bullock ◽

John Parnell ◽

Joseph G.T. Armstrong ◽

Magali Perez ◽

Sam Spinks

Keyword(s):

Heat Flow ◽

Low Temperature ◽

Precious Metals ◽

High Heat ◽

Selenium Content ◽

Foreland Basins ◽

High Heat Flow ◽

South Wales ◽

First Time ◽

Very High

Gold grains, up to 40 μm in size and containing variable percentages of admixed platinum, have been identified in coals from the Leinster Coalfield, Castlecomer, SE Ireland, for the first time. Gold mineralisation occurs in sideritic nodules in coals and in association with pyrite and anomalous selenium content. Mineralisation here may have reflected very high heat flow in foreland basins north of the emerging Variscan orogenic front, responsible for gold occurrence in the South Wales Coalfield. At Castlecomer, gold (–platinum) is attributed to precipitation with replacive pyrite and selenium from groundwaters at redox interfaces, such as siderite nodules. Pyrite in the cores of the nodules indicates fluid ingress. The underlying Caledonian basement bedrock is mineralised by gold, and thus likely provided a source for gold. The combination of the gold occurrences in coal in Castlecomer and in South Wales, proximal to the Variscan orogenic front, suggests that these coals along the front could comprise an exploration target for low-temperature concentrations of precious metals.

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Low-temperature and purification-free stereocontrolled ring-opening polymerisation of lactide in supercritical carbon dioxide

Green Chemistry ◽

10.1039/d0gc00352b ◽

2020 ◽

Vol 22 (7) ◽

pp. 2197-2202 ◽

Cited By ~ 3

Author(s):

Simon P. Bassett ◽

Andrew D. Russell ◽

Paul McKeown ◽

Isabel Robinson ◽

Thomas R. Forder ◽

...

Keyword(s):

Carbon Dioxide ◽

Low Temperature ◽

Supercritical Carbon Dioxide ◽

Ring Opening ◽

Solvent Free ◽

Free Ring ◽

First Time ◽

Supercritical Carbon

A stereoselective, solvent-free ring-opening polymerisation (ROP) of lactide (LA) in supercritical carbon dioxide (scCO2) is reported for the first time.

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Isolation and Characterization of a Biosurfactant Producing Strain Planococcus sp. XW-1 from the Cold Marine Environment

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph19020782 ◽

2022 ◽

Vol 19 (2) ◽

pp. 782

Author(s):

Ping Guo ◽

Weiwei Xu ◽

Shi Tang ◽

Binxia Cao ◽

Danna Wei ◽

...

Keyword(s):

Low Temperature ◽

Carbon Source ◽

Crude Oil ◽

Surface Activity ◽

Yellow Sea ◽

High Surface ◽

Sole Source ◽

The Yellow Sea ◽

Isolation And Characterization ◽

First Time

One cold-adapted strain, named Planococcus sp. XW-1, was isolated from the Yellow Sea. The strain can produce biosurfactant with petroleum as sole source of carbon at low temperature (4 °C). The biosurfactant was identified as glycolipid-type biosurfactant species by thin-layer chromatography (TLC) and Fourier transform infrared spectroscopy (FTIR). It reduced the surface tension of water to 26.8 mN/m with a critical micelle concentration measurement of 60 mg/L. The produced biosurfactant possesses high surface activity at wide ranges of temperature (−18–105 °C), pH values (2–12), and salt concentrations (1–18%). The biosurfactant exhibited higher surface activity and higher growth rate of cells with hexadecane and diesel as carbon source. The strain Planococcus sp. XW-1 was also effective in degrading crude oil, after 21 days of growth at 4 °C in medium with 1% crude oil and 1% (v/v) bacteria broth, 54% of crude oil was degraded. The results suggest that Planococcus sp. XW-1 is a promising candidate for use in the bioremediation of petroleum-contaminated seawater in the Yellow Sea during winter. This study reported for the first time that Planococcus isolated from the Yellow Sea can produce biosurfactant using petroleum as the sole carbon source at low temperature (4 °C), showing its ecological role in the remediation of marine petroleum pollution.

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Polarizing effect in natural polymer cellulose

Plasticheskie massy ◽

10.35164/0554-2901-2019-9-10-45-46 ◽

2019 ◽

pp. 45-46

Author(s):

N. N. Matveev ◽

V. V. Saushkin ◽

N. Yu. Evsikova ◽

N. S. Kamalova ◽

V. I. Lisitsyn

Keyword(s):

Temperature Field ◽

Low Temperature ◽

Natural Polymer ◽

Uniform Temperature ◽

Polarization Mechanism ◽

Uniform Temperature Field ◽

First Time

For the first time, a method based on the registration of polarization and depolarization currents arising in wood in a non-uniform temperature field was used to study the properties of cellulose. The purpose of the method used is to record the relaxation of bound charges with a change in the temperature of the sample under study. It is shown that the detected low-temperature transitions have a crystal-crystal polarization mechanism, and the natural polymer cellulose is an active dielectric.

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