scholarly journals Controls on the Formation and Stability of Siderite (FeCO3) and Chukanovite (Fe2(CO3)(OH)2) in Reducing Environment

Minerals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 156
Author(s):  
Tae-hee Koo ◽  
Jinwook Kim
Keyword(s):  
Reaction Time ◽  
Sedimentary Environment ◽  
Sem Analysis ◽  
Concentration Limit ◽  
Chemical Compositions ◽  
Carbonate Mineral ◽  
Electron Microscopic ◽  
Quantitative Calculation ◽  
Siderite Feco3 ◽  
Ferrous Carbonate

The formation of ferrous carbonate mineral is a significant geochemical reaction linked to iron and carbon cycling in the sedimentary environment. However, knowledge of the controlling factors and conditions for the mineral formation is limited. Two types of ferrous carbonate mineral, siderite (FeCO3) and chukanovite (Fe2(CO3)(OH)2) were synthesized under a FeCl2–NaHCO3 system with various concentration ranges (10–100 mmolal) and ratios (Fe:Dissolved inorganic carbon (DIC) = 1:1, X:50, and 50:X) to verify the concentration limit and control species for the formation of those minerals. The mineralogy of filtered precipitates at the reaction time of 1 week and 1 month were identified by X-ray diffraction (XRD), and scanning/transmission electron microscopic (S/TEM) analyses were applied for direct identification of the synthesized siderite and chukanovite at various conditions. A semi-quantitative calculation to estimate siderite proportion (siderite/[siderite + chukanovite]) in the precipitates was carried out using peak intensity ratios of siderite (d104 [2θ = 32.02°]) and chukanovite (d211 [2θ = 33.98°]) from XRD profiles. The framboids or trigonal-rhombohedron crystals and flaky rosette-shaped minerals were identified in SEM analysis. In addition, the chemical compositions of Fe and C of framboid (Fe:C = 1:1.01) and flaky mineral (1:2.04) were identified as siderite and chukanovite, respectively. The formation of siderite was predominated over chukanovite in 50 mmolal (both Fe and DIC) or higher conditions (siderite proportion = 49–100%). The estimated siderite proportion increased (27–100%) as DIC concentration increased (15–100 mmolal) in conditions of varying ratios of iron and DIC (50:X), indicating that DIC is a decisive factor in siderite formation. The increase in the reaction time promotes the siderite proportion increase, so that chukanovite may be dissolved and re-precipitated as siderite for the long-term reaction, except in the enriched DIC condition (Fe:DIC = 15:50). This study demonstrates that various conditions, not limited to the concentrations or reaction time, may affect the geochemical pathways of carbonate mineral formations.

scholarly journals Preparation and characterization of corn starch/PVA/glycerol composite films incorporated with ε-polylysine as a novel antimicrobial packaging material

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 154-161 ◽  
Author(s):  
Gao Yurong ◽  
Li Dapeng
Keyword(s):  
Water Solubility ◽  
Corn Starch ◽  
Composite Films ◽  
Antimicrobial Properties ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Packaging Material ◽  
Hydroxyl Group ◽  
Electron Microscopic ◽  
Antimicrobial Packaging

AbstractCorn starch/polyvinyl alcohol (PVA)/glycerol composite films incorporated with ε-polylysine were prepared, and their properties were investigated. The Fourier-transform infrared (FTIR) spectroscopy indicated that the interactions happened between the amino group of ε-polylysine and hydroxyl group starch/PVA composite films. X-ray diffraction (XRD) analysis showed that the addition of ε-polylysine decreased the intensity of all crystal peaks. Thermogravimetric (TGA) analysis suggested that ε-polylysine improved the thermal stability of composite films. Scanning electron microscopic (SEM) analysis showed that the upper surface of composite films incorporated with ε-polylysine presented more compact and flat surface. The antimicrobial activity of the composite film progressively increased with the increasing of ε-polylysine concentration (P < 0.05). The tensile strength, elongation at break and water absorption significantly increased, whereas water solubility decreased with the increasing of ε-polylysine concentration (P < 0.05). Therefore, the corn starch/PVA/glycerol composite films incorporated with ε-polylysine had good mechanical, physical and antimicrobial properties and could have potential application as a novel antimicrobial packaging material.

scholarly journals Morphology and morphometry of adult nematodes on Sumatran elephants (Elephas maximus sumatranus) in Way Kambas National Park area, Indonesia

2019 ◽  
Vol 12 (2) ◽  
pp. 249-253 ◽  
Author(s):  
Rahmania Prahardani ◽  
Lintang Winantya Firdausy ◽  
Yanuartono ◽  
Wisnu Nurcahyo
Keyword(s):  
National Park ◽  
Female Worm ◽  
Lateral Lobe ◽  
Sem Analysis ◽  
Elephas Maximus ◽  
Electron Microscopic ◽  
Male Worm ◽  
Way Kambas National Park ◽  
Morphology And Morphometry ◽  
Park Area

Background and Aim: Worms from nematodes are the most numerous and the most detrimental in elephants. Most adult worms are located in the digestive tract. Nematode infection is at higher risk in young elephants, which caused several cases such as anemia, hypoalbuminemia, enteritis, and even death. This study aimed to determine the morphology and morphometry of adult nematodes on Sumatran elephants in Way Kambas National Park area. Materials and Methods: Nematode samples were obtained from Sumatran elephants' feces (Elephas maximus sumatranus) in Way Kambas National Park, Lampung Province, after being given Kalbazen® containing albendazole 1000 mg at a dose of 10 mg/kg by the veterinarian in charge of the National Park area. For the morphological and morphometric examinations, we used an Olympus BX 51 microscope equipped with Olympus DP 12 camera and were conducted at the Parasitology Laboratory, Faculty of Veterinary Medicine, Universitas Gadjah Mada. The scanning electron microscopic (SEM) analysis was carried out at the Biology Research Center of the Indonesian Institute of Sciences (Lembaga Ilmu Pengetahuan Indonesia). Results: The results of macroscopic observations of the obtained nematodes showed that the nematodes which were found have the characteristics of round, slim, and white color. The size of a female worm was larger than a male worm. Microscopic examination in four anterior papillae indicated that the dorsal lobe in the copulatory bursa was longer than lateral lobe. The result of inspection with the SEM showed a leaf crown consisting of 10 elements, a pair of amphids laterally, and two pairs of papilla in a submedian region. Conclusion: Based on our morphology and morphometry examinations of adult nematodes in Sumatran elephant (E. maximus sumatranus) in Way Kambas National Park area, the adult nematodes which were found are species of Quilonia travancra.

scholarly journals Reuse of Municipal Solid Waste from Incinerated Ash in the Stabilization of Clayey Soils

2020 ◽  
Vol 28 (4) ◽  
pp. 1-7
Author(s):  
B. J. S. Varaprasad ◽  
Jayaprakash Reddy Joga ◽  
Suryaprakash Reddy Joga
Keyword(s):  
Municipal Solid Waste ◽  
Solid Waste ◽  
Soil Stabilization ◽  
Sem Analysis ◽  
Primary Objective ◽  
Municipal Solid Wastes ◽  
Electron Microscopic ◽  
Swell Index ◽  
Swell Potential ◽  
Free Swell

AbstractA useful method for the disposal of waste from an incineration plant is to reuse it for geotechnical and civil engineering applications. The primary objective of this study concerns the reuse of local incinerated ash from municipal solid wastes in soil stabilization. Municipal Solid Waste Incinerated Ash (MSWIA) is blended with soil in various combinations and tested for its Atterberg limits, unconfined compressive strength (UCS), California Bearing Ratio (CBR), and Free Swell Index (FSI). A 1-D Consolidation Test was conducted, and changes in the soil during the test were examined by a scanning electron microscopic (SEM) analysis. The test results showed that there are increments in the UCS and CBR values with the reductions in the FSI, swell pressure, and swell potential of the treated soils.

Structural and Optical Characterization of Chemically Synthesized Nanostructured Zinc Oxide Thin Film

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Akintunde Ayodeji Ajayi ◽  
Aderemi Babatunde Alabi ◽  
Olutayo Wale Abodunrin ◽  
Kazeem Adeleke Musiliyu
Keyword(s):  
Thin Film ◽  
Zinc Oxide ◽  
Spray Pyrolysis Technique ◽  
Optical Characterization ◽  
Sem Analysis ◽  
Oxide Thin Film ◽  
Ultraviolet Region ◽  
Chemical Spray Pyrolysis ◽  
Zno Thin Film ◽  
Electron Microscopic

Zinc Oxide (ZnO) thin film has been synthesized using the chemical spray pyrolysis technique and ethylene glycol has been used as solvent during the synthesis. X-ray diffraction (XRD) results show cubic and tetragonal phases of ZnO and the grain size was calculated to be 2.57nm. Optical characterization reveals very high transmittance within the visible-ultraviolet region and a bandgap of 3.49 eV was obtained for ZnO thin film. Scanning Electron Microscopic (SEM) analysis showed a void-free non-homogenous surface.

scholarly journals Geochemical Features of Redox-Sensitive Trace Metals in Sediments under Oxygen-Depleted Marine Environments

Minerals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1021
Author(s):  
Moei Yano ◽  
Kazutaka Yasukawa ◽  
Kentaro Nakamura ◽  
Minoru Ikehara ◽  
Yasuhiro Kato
Keyword(s):  
Sedimentary Environment ◽  
Organic Matter Content ◽  
Oxygen Depletion ◽  
Major And Trace Elements ◽  
Matter Content ◽  
Open Ocean ◽  
Chemical Compositions ◽  
Marine Environments ◽  
High Productivity ◽  
Sedimentary Environments

Organic- and sulfide-rich sediments have formed in oxygen-depleted environments throughout Earth’s history. The fact that they are generally enriched in redox-sensitive elements reflects the sedimentary environment at the time of deposition. Although the modern ocean is well oxidized, oxygen depletion occurs in certain areas such as restricted basins and high-productivity zones. We measured bulk chemical compositions (major and trace elements, total organic carbon, and total sulfur) of organic- and sulfide-rich sediments collected from eight areas having oxygen-depleted water to discuss relationships between geochemical features and sedimentary environments. Major elemental compositions generally show mixtures of terrigenous detritus and biogenic carbonate. Some redox-sensitive elements might be controlled by organic matter content, whereas others could be contained in sulfide minerals in sediments. In particular, Mo and U show a characteristic trend; areas with higher Mo and U—at least partially owing to a depositional process called the “particulate shuttle”—generally correspond to regions influenced by the open ocean. In contrast, areas with lower Mo and U are more restricted marine environments. This suggests that the degree of Mo and U enrichment reflects the geography in terms of proximity to the open ocean, or the degree of the supply of these elements from the open ocean.

scholarly journals Composition and origin of nodules from the ≈20 ka Pomici di Base (PB)-Sarno eruption of Mt. Somma — Vesuvius, Italy

2012 ◽  
Vol 4 (2) ◽  
Author(s):  
Rita Klébesz ◽  
Robert Bodnar ◽  
Benedetto Vivo ◽  
Kálmán Török ◽  
Annamaria Lima ◽  
...  
Keyword(s):  
Melt Inclusions ◽  
Alkali Feldspar ◽  
Sem Analysis ◽  
Chemical Compositions ◽  
Type I ◽  
Type Ii ◽  
Vapor Bubbles ◽  
Ti Oxides ◽  
Basaltic Composition ◽  
Dark Green

AbstractNodules (coarse-grain “plutonic” rocks) were collected from the ca. 20 ka Pomici di Base (PB)-Sarno eruption of Mt. Somma-Vesuvius, Italy. The nodules are classified as monzonite-monzogabbro based on their modal composition. The nodules have porphyrogranular texture, and consist of An-rich plagioclase, K-feldspar, clinopyroxene (ferroan-diopside), mica (phlogopite-biotite) ± olivine and amphibole. Aggregates of irregular intergrowths of mostly alkali feldspar and plagioclase, along with mica, Fe-Ti-oxides and clinopyroxene, in the nodules are interpreted as crystallized melt pockets.Crystallized silicate melt inclusions (MI) are common in the nodules, especially in clinopyroxenes. Two types of MI have been identified. Type I consists of mica, Fe-Ti-oxides and/or dark green spinel, clinopyroxene, feldspar and a vapor bubble. Volatiles (CO2, H2O) could not be detected in the vapor bubbles by Raman spectroscopy. Type II inclusions are generally lighter in color and contain subhedral feldspar and/or glass and several opaque phases, most of which are confirmed to be oxide minerals by SEM analysis. Some of the opaque-appearing phases that are below the surface may be tiny vapor bubbles. The two types of MI have different chemical compositions. Type I MI are classified as phono-tephrite — tephri-phonolite — basaltic trachy-andesite, while Type II MI have basaltic composition. The petrography and MI geochemistry led us to conclude that the nodules represent samples of the crystal mush zone in the active plumbing system of Mt. Somma-Vesuvius that were entrained into the upwelling magma during the PB-Sarno eruption.

Development of an Aging Process for Friction Stir Extruded Joints

2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Adam W. Jarrell ◽  
Brayden C. Terry ◽  
Alvin M. Strauss ◽  
George E. Cook
Keyword(s):  
Heat Treatment ◽  
Aging Process ◽  
Dissimilar Materials ◽  
Sem Analysis ◽  
Post Processing ◽  
Electron Microscopic ◽  
Friction Stir ◽  
Hardening Process ◽  
Scanning Electron Microscopic ◽  
Friction Stir Extrusion

Abstract Friction stir extrusion is a derivative process of friction stir welding for joining dissimilar materials. The process forms a mechanical joint through extrusion to form interlocking features between two metals. When joining AA6061-T6 to mild steel through extrusion of a dovetail, much of the T6 heat treatment of the aluminum in and around the weld is lost during the process. This paper details the examination of a post-processing aging process to return AA6061 to the T6 condition. Through a 10-h precipitation hardening process at 170 °C. The welds experienced a 23.9% increase in the tensile strength from 2193 N as-welded to 2718 N after 10 h. Hardness measurements showed a return close to T6 conditions in both the weld nugget and extruded material, 67.5–83.5 HRF and 54.7–81.8 HRF, respectively, during the heat treatment period. The steel showed no substantial changes in hardness during the heat treatment. Scanning electron microscopic (SEM) analysis revealed significant changes in the sizes of two species of inclusions within the aluminum during both the welding and post-processing.

scholarly journals Smear layer removal capacity of disinfectant solutions used with and without EDTA for the irrigation of canals: a SEM study

2003 ◽  
Vol 17 (4) ◽  
pp. 349-355 ◽  
Author(s):  
Ana Carolina Silveira Cardoso de Menezes ◽  
Caio Gorgulho Zanet ◽  
Márcia Carneiro Valera
Keyword(s):  
Root Canal ◽  
Saline Solution ◽  
Sem Analysis ◽  
Smear Layer ◽  
Electron Microscopic ◽  
Significance Level ◽  
Layer Removal ◽  
Root Canals ◽  
Removal Capacity ◽  
Group 5

The purpose of this study was to carry out a scanning electron microscopic (SEM) analysis of the cleaning qualities and smear layer removal from root canal walls, instrumented and irrigated with 2.5% NaOCl, 2.0% chlorhexidine and saline solutions. Fifty extracted teeth were used in this study. All teeth were radiographed to determine the existence of a single canal. The crowns were cut at the cervical limit and the root canals were instrumented with K-type files up to size 45. During root canal preparation, irrigations were made with the different solutions being evaluated: Group 1: 2.5% NaOCl (10 roots); Group 2: 2.5% NaOCl and 17% EDTA for 2 minute (10 roots); Group 3: 2.0% chlorhexidine (10 roots); Group 4: 2.0% chlorhexidine and 17% EDTA for 2 minutes (10 roots); Group 5: saline solution (5 roots); Group 6: saline solution and 17% EDTA for 2 minutes (5 roots). After instrumentation, the canals were irrigated with each one of the solutions and the roots were cut in the buccolingual direction for SEM analysis, at the cervical, middle and apical thirds, to ascertain the presence or absence of smear layer and debris. SEM analysis was performed by three calibrated examiners and scores were submitted to Kruskal-Wallis test at the significance level of p = 5%. Results showed that the use of 17% EDTA decreased the smear layer significantly (p < 0.05) for all evaluated solutions in all thirds. When EDTA was not used, a significantly higher quantity of smear layer on the apical third was observed only in the NaOCl groups. The use of 17% EDTA was significant for debris removal except for the chlorhexidine groups. The following conclusion could be drawn: the use of 17% EDTA was necessary to enhance cleanness of the root canals.

scholarly journals Effect of orientation of initially formed grains on the final morphology of electrodeposited lead

2014 ◽  
Vol 79 (8) ◽  
pp. 993-1005 ◽  
Author(s):  
Nebojsa Nikolic ◽  
Konstantin Popov ◽  
Evica Ivanovic ◽  
Goran Brankovic
Keyword(s):  
Growth Process ◽  
Sem Analysis ◽  
Diffusion Control ◽  
Lateral Side ◽  
Electron Microscopic ◽  
Initial Shape ◽  
Hexagonal Shape ◽  
Initial Stage ◽  
Scanning Electron Microscopic ◽  
Spherical Diffusion

The processes of Pb electrodeposition in the diffusion control were examined by the scanning electron microscopic (SEM) analysis of the formed crystals. Orientation of grains of hexagonal shape formed in the initial stage of electrodeposition strongly affected the final morphology of Pb crystals. Formation of Pb crystals of the different shape from the same initial shape was discussed by the effect of orientation of initially formed grains on the type of diffusion control. The spherical diffusion layer was formed around the tip of the hexagonal shaped grain oriented by the tip towards the bulk of solution leading to formation of elongated crystals in the growth process. On the other hand, the cylindrical type of diffusion was responsible for growth of hexagonal shaped grains oriented by the lateral side towards the bulk of solution. Pb crystals with well defined sides parallel to the surface area of macroelectrode were formed by this type of diffusion.

The Treatment of Copper-Containing Wastewater by Electrolysis-Enhanced Micro-Electrolysis Fluidized Bed Method

2014 ◽  
Vol 926-930 ◽  
pp. 4402-4405
Author(s):  
Qiang Zhan ◽  
Xiao Jun Xu ◽  
Jing Zhao ◽  
Tian Guo Li
Keyword(s):  
Electron Microscope ◽  
Reaction Time ◽  
Fluidized Bed ◽  
Flow Rate ◽  
Copper Ions ◽  
Sem Analysis ◽  
Solution Ph ◽  
Operation Conditions ◽  
Initial Ph ◽  
Scanning Electron

The effect of electrolysis-enhanced micro-electrolysis fluidized bed technology on treating cooper-containing wastewater had been systematic researched. Operation conditions including applied flow rate, voltage, solution pH and reaction time on the copper ions (Cu2+) removal effect, had been studied scanning electron microscope (SEM) analysis had been used to characterize the surface features of copper crystals in the fillers surface. The results show that the Cu2+ mainly removed by electrochemical deposition, the optimum operation conditions are: flow rate is 22mm/s, voltage is 12V, initial pH=4, the response time of 30 min.

Sign in / Sign up

Export Citation Format

Share Document