scholarly journals Supergénne minerály z U-Cu rudného výskytu Východná-Nižný Chmelienec v Nízkych Tatrách (hronikum, Slovensko)

2021 ◽  
Vol 29 (1) ◽  
pp. 77-89
Author(s):  
Eva Hoppanová ◽  
Štefan Ferenc ◽  
Richard Kopáčik ◽  
Šimon Budzák ◽  
Tomáš Mikuš
Keyword(s):  
Chemical Composition ◽  
Empirical Formula ◽  
Average Chemical Composition ◽  
Bending Vibration ◽  
Thin Coatings ◽  
Mine Dumps ◽  
Organic Impurities ◽  
Stretching Vibration ◽  
Uranyl Phosphates ◽  
A Minor

An association of supergene U-Cu and Y/REE minerals was found in a relic of old ore dump at the abandoned U deposit occurrence Východná-Nižný Chmelienec, the northern slopes of the Nízke Tatry Mts., Slovakia. They have partially recent origin, since exploration of the locality took place between 1965 and 1966. The studied mineral assem- blage is represented by goethite, malachite, uranophane and (meta)zeunerite, in a lesser extent baryte and rare zálesíite. Uranophane appears separately (globular aggregates, thin coatings) and it also forms the main part of the yellow to yellow-green crystalline crusts on the rock cracks. The chemical composition of the uranophane was determined by electron microprobe analyses and it is close to its ideal chemical formula Ca(UO2)2(SiO3OH)2·5H2O. The average chemical composition of the studied uranophane can be expressed by an empirical formula (Ca1.0Mg0.02K0.01Fe0.01Ba0.01)Σ1.05 (UO2)2.08(SiO3OH)1.84·5H2O. The infrared vibrational spectra of the studied uranophane show 3 (UO2)2+ at 850-760 cm-1; the 3 (SiO4)4- antisymmetric stretching vibration at 1000-900 cm-1; the 1 (SiO4)4- symmetric stretching vibration at 1150-1199 cm-1; the  H2O bending vibration at 1800-1600 cm-1 and OH stretching vibrations at 3407; 3408 and 3409 cm-1. The weak bands 2648; 2646 and 2651 cm-1 may be assigned to organic impurities. The calculated U-O bond length 1.83 Å corresponds to short U-O bonds in uranophane. The accessory admixtures of uranophane coatings are (meta)zeunerite and zálesíite. (Meta)zeunerite occasionally forms thin coatings of light green to emerald green tabular crystals (up tu 0.5 mm) on the surface of the rocks. Chemical analyses of (meta)zeunerite correspond to the empirical formula (Cu0.66K0.03Fe0.01Ca0.01)Σ0.71(UO2)2.11[(AsO4)1.96(PO4)0.01]Σ1.97·12H2O. Zálesíite occurs as crystalline aggregates, nests, formed by tiny acicular crystals, up to 100 µm in length. This is the second finding (occurrence) of this mineral in Slovakia. An average zálesíite chemical composition is (Ca0.83REE0.18U0.05Al0.03Ti0.01)Σ1.10(Cu5.81Fe0.06Zn0.02)Σ5.90[(AsO4)2.75 (SiO4)0.21(PO4)0.02(SO4)0.03]Σ3.01(OH)5.10·3H2O. Malachite, which has been also found in the association, is only a minor mineral in the studied locality. The formation of uranyl silicates (uranophane) and minerals of the mixite group (zálesíite), present at the studied locality, points to neutralization of acidic supergene fluids in the mine dumps. Possibly, this environment later (precipitation of baryte) passed to neutral or slightly basic conditions (precipitation of carbonates - malachite). The identified uranyl phosphates/arsenates (zeunerite/metazeunerite), typical of an acidic environment, are therefore rare.

scholarly journals Avocado-Derived Biomass: Chemical Composition and Antioxidant Potential

Proceedings ◽  
2020 ◽  
Vol 70 (1) ◽  
pp. 100
Author(s):  
Minerva C. García-Vargas ◽  
María del Mar Contreras ◽  
Irene Gómez-Cruz ◽  
Juan Miguel Romero-García ◽  
Eulogio Castro
Keyword(s):  
Chemical Composition ◽  
Phenolic Content ◽  
Antioxidant Properties ◽  
Total Phenolic ◽  
Nutritional Properties ◽  
Aqueous Fraction ◽  
Extraction Solvent ◽  
Main Components ◽  
A Minor ◽  
Derivatives Of

Avocado has become fashionable due to its great organoleptic and nutritional properties. It is consumed as a fresh product and it is also processed to obtain salad oil and guacamole. In all cases, the only usable portion is the pulp. Therefore, to be a more sustainable and profitable agribusiness, it is important to recognize which compounds from the peel and the stone waste can be converted into valuable bio-products. Therefore, their chemical composition was determined according to the National Renewable Energy Laboratory, the total phenolic content by the Folin-Ciocalteu method and the antioxidant properties by the FRAP and TEAC assays. The main components of the peel and stone were acid-insoluble lignin (35.0% and 15.3%, respectively), polymeric sugars (23.6% and 43.9%, respectively), and the aqueous extractives (15.5% and 16.9%, respectively). Both biomasses contain lipids and protein, but a minor proportion (<6%). The valorization of lignin and sugars is of interest given the high content; stones are a rich source of glucose (93.2% of the polymeric fraction), which could be used to obtain biofuels or derivatives of interest. The extractive fraction of the peel contained the highest number of phenolic compounds (4.7 g/100 g biomass), mainly concentrated in the aqueous fraction (i.e., 87%) compared to the ethanol one, which was subsequently extracted. It correlated with major antioxidant activity and, therefore, the peel can be applied to obtain antioxidants and water can be used as an environmentally friendly extraction solvent.

Pb-Sb zrudnění z Antimonitové žíly, důl Rudolf, Bohutín (Česká republika)

2021 ◽  
Vol 29 (2) ◽  
pp. 275-280
Author(s):  
Pavel Škácha ◽  
Jiří Sejkora
Keyword(s):  
Czech Republic ◽  
Chemical Composition ◽  
Empirical Formula ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Ore District ◽  
Archive Material

The Pb-Sb mineralization with dominant stibnite and plagionite and associated semseyite and zinkenite was found in an archive material collected at the Antimonitová vein, Bohutín, Březové Hory ore district (Czech Republic). Plagionite forms subhedral aggregates up to 1 mm in size. The unit-cell parameters of plagionite for monoclinic space group C2/c refined from the X-ray powder data are: a 13.4890(17), b 11.8670(14), c 19.997(2) Å, β 107.199(8)° and V 3057.9(6) Å3. Its chemical composition (average of 26 analyses, based on 30 apfu) corresponds to the empirical formula Pb5.02Sb8.15S16.82. Associated zinkenite is forming subhedral crystals up to 1 mm in size. Its empirical formula can be expressed as (Cu0.25Ag0.02Fe0.01)Σ0.28Pb9.22Sb22.19S41.31 (average of 26 analyses, based on 73 apfu). Semseyite aggregates have the empirical formula (Pb8.72Fe0.14)8.86Sb8.42S20.73 (average of 11 analyses, based on 38 apfu).

scholarly journals Impact of Commercial Oenotannin and Mannoprotein Products on the Chemical and Sensory Properties of Shiraz Wines Made from Sequentially Harvested Fruit

Foods ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 204 ◽  
Author(s):  
Sijing Li ◽  
Keren Bindon ◽  
Susan Bastian ◽  
Kerry Wilkinson
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Chemical Composition ◽  
High Performance ◽  
Red Wine ◽  
Descriptive Analysis ◽  
Sensory Properties ◽  
Fruit Maturity ◽  
A Minor ◽  
Early Harvest

The tannin and polysaccharide profiles and therefore sensory properties of wine are influenced by fruit maturity at harvest, and practices employed during winemaking. This study investigated the extent to which commercial winemaking supplements (skin and seed tannins, and mannoprotein (MP)) can enhance the mouthfeel properties of red wine, in particular, wine made from grapes harvested before commercial ripeness (early-harvest). Supplements were added to wines made from Shiraz grapes harvested at 20.8 and 24.5 °Brix. The chemical composition and mouthfeel properties of wines were then determined by high performance liquid chromatography and descriptive analysis (DA), respectively. Wines made from riper grapes had higher levels of tannin than wines made from early-harvest grapes, but similar polysaccharide levels were observed. The addition of seed oenotannin yielded higher tannin levels than addition of skin oenotannin, particularly for wines made from early-harvest grapes. The DA panel perceived sensory differences between H1 and H2 wines, but could not perceive any effect of supplementation on wine mouthfeel properties, with the exception of a minor increase in sweetness, attributed to mannoprotein addition to H1 wines, even when MP was added to wines at 2.5 times the level recommended for use in Australia.

scholarly journals The nutritive value of the indigenous grasses of Surinam.

1963 ◽  
Vol 11 (4) ◽  
pp. 295-307
Author(s):  
J.G.P. Dirven
Keyword(s):  
Chemical Composition ◽  
Dairy Cattle ◽  
Mineral Composition ◽  
Soil Type ◽  
Growth Stage ◽  
Nutritive Value ◽  
Ionic Balance ◽  
Average Chemical Composition

Data are given on the average chemical composition of herbage from natural pastures in relation to soil type and the feed requirements of dairy cattle, and on the composition of various species and the effects of growth stage. Mineral composition and ionic balance are discussed.-R.B. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals Comparing the Efficiencies of the Removal of Cadmium from Industrial Wastewater Using Zeolites

2020 ◽  
pp. 6-18
Author(s):  
Michael Akrofi Anang ◽  
Ruphino Zugle ◽  
Baah Sefa- Ntiri
Keyword(s):  
Rice Husk ◽  
Industrial Wastewater ◽  
Raw Materials ◽  
Research Work ◽  
Corn Stalk ◽  
Zeolite X ◽  
Bending Vibration ◽  
Strong Peak ◽  
Corn Husk ◽  
Stretching Vibration

The presence of heavy metals in industrial wastewater needed to be removed in other to control pollution which has been caused as a result of human and industrial activities. Several adsorbents have been used for the remediation process but with this particular research work, Zeolites were used. They were synthesized hydrothermally from various locally available raw materials namely rice husk, corn stalk, corn husk, and kaolin. They were characterized using their FTIR to determine the functional groups on the material synthesized and also their adsorptive activities were compared with industrially synthesized Zeolite X. A very strong peak at 1052 cm-1 is as a result of the asymmetric vibrations of the internal T-O tetrahedron with a weak symmetric T-O stretching vibration recorded at 797 cm-1. Another strong peak was observed at 445 cm-1 as a result of the O-T-O bending vibration which confirms the presence of a five-membered structure. The adsorptive properties of the synthesized Zeolites were evaluated by using them to remove Cadmium ions from solution and their percentage removals were determined. Similarly, their adsorption kinetics were also determined and was observed the R2 values to be 0.9093 and 0.9454 for Corn husk and Cornstalk for the first order and the second order with R2 values of 1 for rice husk, kaolin and corn stalk.

Abstract 414: In Hyperalphalipoproteinemic Subjects, the Presence of Coronary Artery Disease is Associated With Marked Changes in the High-Density Lipoprotein Phosphosphingolipidome

2014 ◽  
Vol 34 (suppl_1) ◽  
Author(s):  
William Hancock-Cerutti ◽  
Marie Lhomme ◽  
Carolane Dauteuille ◽  
Sora Lecocq ◽  
John Chapman ◽  
...  
Keyword(s):  
Coronary Artery Disease ◽  
Coronary Artery ◽  
Chemical Composition ◽  
Plasma Concentrations ◽  
Density Lipoprotein ◽  
Edta Plasma ◽  
Novel Method ◽  
Artery Disease ◽  
Causal Nature ◽  
A Minor

Plasma concentrations of HDL-C have long been shown to correlate inversely with risk of coronary artery disease (CAD), however the causal nature of this association has not been established. Here we examine the chemical composition and phosphoshingolipidome of HDL in a cohort of subjects with premature CAD, despite having HDL levels ≥90th percentile. We hypothesized that HDL from hyperalphalipoproteinemic subjects with CAD would have distinct compositional changes compared to healthy hyperalphalipoproteinemic subjects, which may relate a reduction in HDL functionality and a pro-atherogenic state. Subjects with HDL ≥90th percentile and CAD (HHDL+CAD, n=25) were compared to healthy subjects with HDL ≥90th percentile (HHDL, n=23). A group of healthy controls with HDL between the 25th and 75th percentile (n=11) was used as reference. HDL subfractions were isolated from EDTA plasma using isopycnic density gradient ultracentrifugation and their chemical composition was assayed using commercial enzymatic assay kits. Quantification of >160 molecular species of total HDL phospho- and sphingolipids was accomplished via a novel method using LC-ESI/MS/MS analysis. The most striking differences were observed in total HDL phospho- and sphingolipid subclasses between groups. When expressed as a percentage of total phosphosphingolipid, phosphatidylcholine (PC) and phosphatidylinositol (PI) were depleted in HHDL+CAD group compared to HHDL, while sphingomyelin (SM) was increased, resulting in a lower PC/SM ratio. The HDL PC/SM ratio has previously been shown to correlate with HDL surface fluidity and antioxidative activity. Additionally, enrichment of PI, a minor, negatively charged phospholipid, has been shown to stimulate cholesterol efflux to reconstituted HDL. Reduction in these two metrics, observed in the HHDL+CAD group, may indicate functionally deficient HDL and may represent pro-atherogenic, HDL-associated biomarkers of CAD in hyperalphalipoproteinemia.

scholarly journals Micro-Raman Spectroscopy Assessment of Chemical Compounds of Mantle Clinopyroxenes

Minerals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1084
Author(s):  
Anastasiya D. Kalugina ◽  
Dmitry A. Zedgenizov
Keyword(s):  
Raman Spectroscopy ◽  
Chemical Composition ◽  
Chemical Compounds ◽  
Peak Position ◽  
Mantle Xenoliths ◽  
Wide Range ◽  
Stretching Vibration ◽  
Raman Modes ◽  
Non Destructive ◽  
Heterovalent Isomorphism

The composition of clinopyroxenes is indicative for chemical and physical properties of mantle substrates. In this study, we present the results of Raman spectroscopy examination of clinopyroxene inclusions in natural diamonds (n = 51) and clinopyroxenes from mantle xenoliths of peridotites and eclogites from kimberlites (n = 28). The chemical composition of studied clinopyroxenes shows wide variations indicating their origin in different mantle lithologies. All clinopyroxenes have intense Raman modes corresponding to metal-oxygen translation (~300–500 cm−1), stretching vibrations of bridging O-Si-Obr (ν11~670 cm−1), and nonbridging atoms O-Si-Onbr (ν16~1000 cm−1). The peak position of the stretching vibration mode (ν11) for the studied clinopyroxenes varies in a wide range (23 cm−1) and generally correlates with their chemical composition and reflects the diopside-jadeite heterovalent isomorphism. These correlations may be used for rough estimation of these compounds using the non-destructive Raman spectroscopy technique.

scholarly journals A comparative study of the proteoglycan of growth cartilage of normal and rachitic chicks

1978 ◽  
Vol 171 (3) ◽  
pp. 675-682 ◽  
Author(s):  
I R Dickson ◽  
P J Roughley
Keyword(s):  
Chemical Composition ◽  
Comparative Study ◽  
Physical Properties ◽  
Proteolytic Cleavage ◽  
Average Chemical Composition ◽  
Normal Cartilage ◽  
Nasal Cartilage ◽  
Growth Cartilage

1. Proteoglycan was isolated from growth cartilage of normal and rachitic chicks. 2. The proteoglycan from normal cartilage showed differences in chemical composition and physical properties from a comparable fraction isolated from bovine nasal cartilage. 3. The proteoglycan from rachitic-chick cartilage was of smaller size than tis normal counterpart, though of similar average chemical composition. 4. Differences between proteoglycan from normal and rachitic cartilages can be explained in terms of limited proteolytic cleavage.

scholarly journals Micro-FTIR and EPMA Characterisation of Charoite from Murun Massif (Russia)

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Maria Lacalamita
Keyword(s):  
Single Crystal ◽  
Complex Structure ◽  
Structural Complexity ◽  
Adsorbed Water ◽  
Bending Vibration ◽  
Structural Water ◽  
Stretching Vibration ◽  
Vibrational Features ◽  
Polytype Structure ◽  
Insight Into

Combined micro-Fourier transform infrared (micro-FTIR) and electron probe microanalyses (EPMA) were performed on a single crystal of charoite from Murun Massif (Russia) in order to get a deeper insight into the vibrational features of crystals with complex structure and chemistry. The micro-FTIR study of a single crystal of charoite was collected in the 6000–400 cm−1 at room temperature and after heating at 100°C. The structural complexity of this mineral is reflected by its infrared spectrum. The analysis revealed a prominent absorption in the OH stretching region as a consequence of band overlapping due to a combination of H2O and OH stretching vibrations. Several overtones of the O-H and Si-O stretching vibration bands were observed at about 4440 and 4080 cm−1 such as absorption possibly due to the organic matter at about 3000–2800 cm−1. No significant change due to the loss of adsorbed water was observed in the spectrum obtained after heating. The occurrence of well-resolved water bending vibration bands at about 1595 and 1667 cm−1 accounts for more than one structural water molecule as expected by charoite-90 polytype structure model from literature. The chemical composition of the studied crystal is close to the literature one.

Geochemistry of the Athabasca Basin, Saskatchewan, Canada, and the Unconformity-related Uranium Deposits Hosted By It

2020 ◽  
Author(s):  
Paul Alexandre
Keyword(s):  
Chemical Composition ◽  
Large Data ◽  
Aluminum Phosphate ◽  
Enrichment Factors ◽  
Uranium Deposits ◽  
Average Chemical Composition ◽  
Data Set ◽  
Athabasca Basin ◽  
Ore Bodies ◽  
Five Elements

Abstract A large data set comprising near-total digestion analyses of whole rock samples from the Athabasca Basin, Saskatchewan, Canada (based principally on the Geological Survey of Canada open file 7495), containing more than 20,000 analyses, was used to define the average chemical composition of Athabasca Group sandstones and of unconformity-related uranium deposits hosted by the basin. The chemical composition of unaltered and un-mineralized Athabasca Group sandstones is dominated by Al (median Al2O3 of 1.14 wt.%), Fe (median Fe2O3 of 0.24 wt.%), and K (median K2O of 0.11 wt.%; Si was not measured), corresponding mostly to the presence of kaolin, illite, and hematite, in addition to the most-abundant quartz. The median concentration of U in the barren sandstones is 1 ppm, with 5 ppm Th, 3 ppm Pb, and 56 ppm ΣREE. Other trace elements present in significant amounts are Zr (median of 100 ppm), Sr (median of 69 ppm), and B (median of 43 ppm), corresponding to the presence of zircon, illite, and dravite. The elements most enriched in a typical Athabasca Basin unconformity-related uranium deposit relative to the barren sandstone are U (median enrichment of ×710), Bi (×175), V (×77), and Mg (×45), followed by five elements with enrichment factors between 20 and 30 (Co, Mo, K, As, and Ni). These correspond to the presence in the ore bodies of alteration minerals (dravite, kaolinite, illite, chlorite, aluminum-phosphate-sulfate minerals, and a suite of sulfide minerals) and are similar to what has been observed before. These elements are similar to the typical pathfinder elements described above known deposits, but their usefulness has to be assessed based on their relative mobility in the predominantly oxidizing Athabasca Basin sandstones.

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