scholarly journals “Horsetail” Inclusions in the Ural Demantoids: Growth Formations

Minerals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 825
Author(s):  
Aleksander Yurevich Kissin ◽  
Valery Vasilevich Murzin ◽  
Elizaveta Sergeevna Karaseva
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Raman Spectrometry ◽  
X Ray ◽  
Naked Eye ◽  
Highly Dispersed ◽  
Amphibole Asbestos ◽  
Central Urals ◽  
Scanning Electron

The term “demantoid”, first proposed in 1856 by the famous Finnish mineralogist Nils von Nordensheld, refers to a highly dispersed yellow-green mineral from the Central Urals placers. In 1874, it was found to be a gem variety of andradite garnet. “Horsetail” inclusions are considered a sign of the Ural type demantoid. Although these inclusions are large (visible to the naked eye), their diagnostics remains debatable: some researchers attribute them to byssolite (amphibole-asbestos), others consider them chrysotile. We investigated the horsetail inclusions in the Ural demantoids through various methods: optical microscopy, scanning electron microscopy (SEM), Raman spectrometry, X-ray powder diffraction, and thermal analysis. In most cases, “horsetail” inclusions in the Ural demantoid were represented by hollow channels and only the outcrops, on the demantoid surface, were occasionally filled with serpentine (established by SEM); in one case, magnetite was observed. Hollow canals were usually collected not in bundles, such as a “horsetail”, but in fans, sometimes curved into cones. The structure of the grains was spheroidal, sectorial, and sometimes had induction surfaces, which, to the periphery of the grain, were replaced by tubular channels assembled in a fan. The specifics of the growth of the “horsetail” inclusions of the demantoid grains can be explained by the decompression conditions that arose when the ultrabasites (a crust-mantle mixture) were squeezed upwards during collision.

PENINGKATAN LAJU DISOLUSI ACYCLOVIR DENGAN METODE SISTEM DISPERSI PADAT MENGGUNAKAN POLOXAMER 188

2016 ◽  
Vol 5 (1) ◽  
pp. 6
Author(s):  
Budi Setiawan ◽  
Erizal Zaini ◽  
Salman Umar
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Fourier Transform ◽  
Differential Thermal Analysis ◽  
Fourier Transform Infrared ◽  
X Ray Diffraction ◽  
Poloxamer 188 ◽  
X Ray ◽  
Scanning Electron

Sebuah penelitian tentang sistem dispersi padat dari asiklovir dengan poloxamer 188 telah dilakukan formulasi dengan pencampuran secara fisika dengan rasio 1 : 1, 1 : 3, 1 : 5 dan dispersi padat 1 : 1, 1 : 3, 1 : 5 dan penggilingan 1:1 sebagai pembanding. Dispersi padat dibuat menggunakan metode pencairan (fusi), yang digabung dengan poloxamer 188 pada hotplate kemudian asiklovir dimasukkan ke dalam hasil poloxamer 188 lalu di kocok hingga membentuk masa homogen. Semua formula yang terbentuk termasuk asiklovir poloxamer 188 murni dianalisis karakterisasinya dengan Differential Thermal Analysis (DTA), X-ray Diffraction, Scanning Electron Microscopy (SEM), dan Fourier Transform Infrared (FTIR), kemudian pengambilan dilakukan  (penentuan kadar) mengunakan spektrofotometer UV pada panjang gelombang 257,08 nm dan uji laju disolusi dengan aquadest bebas CO2 menggunakan metode dayung. Hasil pengambilan  (penentuan kadar) menunjukkan bahwa semua formula memenuhi persyaratan farmakope Amerika edisi 30 dan farmakope Indonesia edisi 4 yaitu 95-110%. Sedangkan hasil uji laju disolusi untuk campuran fisik 1: 1, dan dispersi padat 1: 1, dan penggilingan 1: 1 menunjukkan peningkatan yang nyata dibandingkan asiklovir murni. Hal ini juga dapat dilihat dari hasil perhitungan statistik  menggunakan analisis varian satu arah  SPSS 17.

Effect of Heat Treatments on Wettability of Nacre

2020 ◽  
Vol 985 ◽  
pp. 86-90
Author(s):  
Andi Muhammad Anshar ◽  
Sengo Kobayashi ◽  
Satoshi Okano
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Heating Temperature ◽  
Pearl Oyster ◽  
Heat Treatments ◽  
Organic Substances ◽  
Water Contact ◽  
X Ray ◽  
Scanning Electron

The surface wettability of biomaterials influences on osteoblast behavior and bone formation. In this research, the variation of wettability of nacre by heat treatments was examined. Plates of the nacre were fabricated from shells of the Akoya pearl oyster. The specimens were heated at 100, 200, 300, 400, 500, and 600 °C. Characterizations of the specimens during and after heat treatments were carried out using scanning electron microscopy, X-ray diffractometry, and thermogravimetry-differential thermal analysis. The water contact angle (WCA) of the specimen was measured to evaluate wettability. The color of nacre changed from iridescent color to brownish weak-iridescence by the heating at and over 300 °C. The nacre heated at and over 300 °C became brittle because organic substances in nacre, which acts as the glue between the aragonite platelets were evaporated by the heating. The WCA of the specimen was decreased with increasing heating temperature, which should be related to the decrease in the number of organic substances in nacre by the heating.

Darstellung und Charakterisierung des Silber(I,II,III)-oxidclathrates Ag7O8HCO3 / Synthesis and Characterization of the Silver(I,II,III) Oxide Clathrate Ag7O8HCO3

2000 ◽  
Vol 55 (9) ◽  
pp. 882-886 ◽  
Author(s):  
Martin Jansen ◽  
Sascha Vensky
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Magnetic Susceptibility ◽  
Solid State Nmr ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

The silver(I,II,III) oxide clathrate Ag7O8HCO3 was synthesized by anodic oxidation of silver(I) in a suspension of Ag2CO3 in an aqueous AgF solution. The title compound was characterized by single crystal X-ray diffraction (cubic, Fm3̄m, a = 9.8085(3) Å, Z = 4), scanning electron microscopy, thermal analysis, IR spectroscopy, 1H-solid state-NMR and measurement of the magnetic susceptibility

Preparation and Properties of Sintering Brick from Iron Tailings

2012 ◽  
Vol 512-515 ◽  
pp. 1023-1027
Author(s):  
Ran Fang Zuo ◽  
Gao Xiang Du ◽  
Le Fu Mei ◽  
Wei Juan Guo ◽  
Jing Hui Liao
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Bulk Density ◽  
Raw Materials ◽  
Loss On Ignition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Freeze Thaw ◽  
Scanning Electron

The main objective of this paper was to investigate the addition of iron tailing sintering brick production, in the presence of clay, coal refuses and bentonite. Mixtures containing raw materials of sintering brick and iron tailings were prepared at different proportions (up to 55 wt %), fired at 980°C. Freeze/thaw durability, drying and firing shrinkages were investigated as well as the loss on ignition, bulk density and compressive strength of the fired samples. Their mechanical and microstructure properties were also investigated by differential thermal analysis (DTA/TG), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results showed that compressive strengths of the brick samples are higher than that required by the standards MU15 of GB5101-2003, up to 21.79Mpa with 40% iron tailings corresponding to its higher bulk density completely. Moreover, the results showed that it has such advantages as no lime blowing, uniform color, good freeze/thaw resistance and slight universal frost.

Crystal Structure of BiFeO3 Synthesized Using the Hydrothermal Processing

2014 ◽  
Vol 602-603 ◽  
pp. 947-950
Author(s):  
Zhen Wang ◽  
Hai Yan Chen ◽  
Lin Qiang Gao ◽  
Xin Zou
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Single Phase ◽  
Hydrothermal Processing ◽  
Optimal Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

BiFeO3 nanoparticles were successfully synthesized by a hydrothermal method by a mineralizer (KNO3). Structural characterization was performed by thermal analysis, powder X-ray diffraction (XRD) and scanning electron microscopy (TEM).The results showed that the products were perovskite structure BiFeO3 powders. Optimal conditions for the synthesis of single-phase BiFeO3 ceramics were obtained.

scholarly journals Manilkara zapota (Linn.) Seeds: A Potential Source of Natural Gum

2014 ◽  
Vol 2014 ◽  
pp. 1-10
Author(s):  
Sudarshan Singh ◽  
Sunil B. Bothara
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Particle Size ◽  
Gel Permeation Chromatography ◽  
X Ray Diffraction ◽  
X Ray ◽  
Manilkara Zapota ◽  
Gel Permeation ◽  
Scanning Electron

Mucilage isolated from seeds of Manilkara zapota (Linn.) P. Royen syn. is a plant growing naturally in the forests of India. This mucilage is yet to be commercially exploited, and characterized as polymer. Various physicochemical methods like particle size analysis, scanning electron microscopy, thermal analysis, gel permeation chromatography, X-ray diffraction spectrometry, zeta potential, Fourier transform infrared spectroscopy, and nuclear magnetic resonance spectroscopy have been employed to characterize this gum in the present study. Particle size analyses suggest that mucilage has particle size in nanometer. Scanning electron microscopy analysis suggests that the mucilage has irregular particle size. The glass transition temperature of the gum was observed to be 138°C and 136°C by differential scanning calorimetry and differential thermal analysis, respectively. The thermogravimetric analysis suggested that mucilage had good thermal stability. The average molecular weight of mucilage was determined to be 379180, by gel permeation chromatography, while the viscosity of mucilage was observed to be 219.1 cP. The X-ray diffraction spectrometry pattern of the mucilage indicates a completely amorphous structure. Elemental analysis of the gum revealed the contents of carbon, hydrogen, nitrogen, and sulfur to be 80.9 (%), 10.1 (%), 1.58 (%), and 512 (mg/kg), respectively. Mucilage had specific content of calcium, magnesium, potassium, lower concentrations of aluminum, cadmium, cobalt, lead, and nickel. The major functional groups identified from FT-IR spectrum include 3441 cm−1 (–OH), 1660 cm−1 (Alkenyl C–H & C=C Stretch), 1632 cm−1 (–COO–), 1414 cm−1 (–COO–), and 1219 cm−1 (–CH3CO). Analysis of mucilage by paper chromatography and 1D NMR, indicated the presence of rhamnose, xylose, arabinose, mannose, and fructose.

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