• Title/Summary/Keyword: Silver carbonate

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Study of Antimicrobial Properties for Silver/Celite Composites (은/셀라이트 복합체의 항균특성에 관한 연구)

  • Lee, Chul-Jae;Kim, Byung-So
    • Applied Chemistry for Engineering
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    • v.20 no.6
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    • pp.696-699
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    • 2009
  • In present work, the antimicrobial effect of silver-nanoparticles/celite (SN/C) and silver carbonate/celite (SC/C) composites on Escherichia coli (E. coli) by use of silver nanoparticles and silver carbonate has been studied. Characteristics of the SN/C and SC/C composites were identified by scanning electron microscopy (SEM), X-ray diffraction (XRD) and atomic absorption spectroscopy (AAS). SN/C and SC/C composites showed antimicrobial activity and the minimum inhibitory concentration of E. coli were 0.541, 0.344 ppm and the complete sterilizing concentration for the test organism were 1.427, 1.623 ppm. From the results we identified that SN/C and SC/C composites have antimicrobial activity to E. coli.

Production of Ag- Ni fine powder by coprecipitation (공침법을 이용한 Ag-Ni 초미분 제조)

  • Kim, Bong-Seo;Woo, Byung-Chul;Byun, Woo-Bong;Lee, Hee-Woong
    • Proceedings of the KIEE Conference
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    • 1994.07b
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    • pp.1342-1344
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    • 1994
  • Silver-Nickel alloy has been used as a electrical contact material for low voltage, low current. Since the solubility between Ag and Ni is very low, it is difficult to produce Ag-Ni alloy by using conventional melting method and disperse Ni powder homogeneously in Ag matrix. In this study we have been produced fine Ag-Ni alloy powder by using coprecipitation method. Firstly, we have produced silver-nickel nitrate solution by dissolving the Ag and Ni ingot in nitric acid solution and then, coprecipitate (Ag, Ni)carbonate dropping Ag-Ni nitrate solution to sodium carbonate solution. (Ag, Ni) carbonate is heat-treated in $H_2$ atmosphere, $400^{\circ}C$ and it has been analysed by TGA, SEM, XRD, ICP. It is represented Silver-Nickel alloy powder in the particle range of $0.1{\sim}0.5{\mu}m$.

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Preparation of $Ginsenoside-Rh_2$ from Dammarane Saponins of Panax ginseng Leaves (인삼잎의 Dammarane계 사포닌으로부터 $Ginsenoside-Rh_2$의 제조)

  • Cha, Bae-Cheon;Lee, Sang-Guk
    • YAKHAK HOEJI
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    • v.38 no.4
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    • pp.425-429
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    • 1994
  • The genuine aglycone, 20(S)-protopanaxadiol, obtained from the leaves of Panax ginseng as a result of direct alkaline treatment was isolated and characterized by spectroscopic evidences. The study on the yield of genuine aglycone which is produced from the treatment of some kinds of alkali was carried out. $Ginsenoside-Rh_2$ was synthesized by conjugation of 2,3,4,6-tetra-O-acetyl-${\alpha}$-D-glucopyranosyl bromide to 20(S)-protopanaxadiol in the presence of silver carbonate and cadmium cabonate. The preparation of $ginsenoside-Rh_2$ by this method is a new one which the yield of this saponin can be improved in the mild condition.

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New Record of Two Oligohymenophorean Ciliates (Protozoa: Ciliophora) from Korea

  • Jung, Jae-Ho
    • Animal Systematics, Evolution and Diversity
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    • v.37 no.4
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    • pp.280-286
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    • 2021
  • During a field survey on Korean coastal marine waters, two ciliates belonging to the genera Pseudovorticella Foissner & Schiffmann, 1975 and Frontonia Ehrenberg, 1838 in the class Oligohymenophorea de Puytorac et al., 1974, were collected. Even though the two genera are very common in the aquatic ecosystems, they had been superficially studied in Korean habitats. Using the observation of living cells and specimens impregnated by protargol, silver carbonate, and silver nitrate, two newly recorded ciliate are identified as P. paramarina Sun, Ji, Warren & Song, 2009 and F. ocularis Bullington, 1939. A brief diagnosis, remark, and comprehensive micrographs are provided for each species.

Genesis of the Lead-Zinc-Silver and Iron Deposits of the Janggun Mine, as Related to Their Structural Features Structural Control and Wall Rock Alteration of Ore-Formation (장군광산(將軍鑛山)의 연(鉛)·아연(亞鉛)·은(銀) 및 철(鐵) 광상(鑛床)의 성인(成因)과 지질구조(地質構造)와의 관계(關係) - 광상(鑛床) 생성(生成)의 지질구조(地質構造) 규제(規制)와 모암(母岩)의 변질(變質) -)

  • Lee, Hyun Koo;Ko, Suck Jin;Naoya, Imai
    • Economic and Environmental Geology
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    • v.23 no.2
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    • pp.161-181
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    • 1990
  • The lead-zinc-silver-iron deposits from the Janggun mine are of hydrothermal-metasomatic origin, characterized by the marked hydrothermal alteration of the wallrocks, such as hydrothermal manganese enrichment of carbonate rocks, silicification, chloritization, sericitization, montmorillonitization and argillic alteration. The ore deposits have been emplaced within the Janggun Limestone of Cambro-Ordovician age at the immediate contacts with apophyses injected from the Chunyang Granite plutons of Late Jurrasic age. They have been structurally controlled by fractures in the carbonate rocks and the irregular intrusive contacts of granitic rocks, and are closely associated with hypogene manganese carbonate deposits. In the mine nine seperate orebodies are being mined. On the basis of the petrological study, hydrothermal alteration zone of this mine may be divided into the following four zones from wallrock to orebody. (I) Primary calcite and dolomite zone${\rightarrow}$(II) dolomitic limestone zone${\rightarrow}$(III) dolomitic zone${\rightarrow}$(IV) rhodochrosite zone${\rightarrow}$ orebody. There was not recongnized Mn and Fe elements in the primary calcite and dolomite zone. But, in the dolomitic limestone and dolomite zone, calcite and dolomite were subjected to weak hydrothermal manganese enrichment and the grade of the manganese enrichment increase oreward. By means of electron probe microanalysis, it was found that manganoan dolomite occured between primary dolomite grains, cross the cleavage of the primary dolomite and around the dolomite grains. Above these result supports that the Janggun manganese carbonate deposits are of hydrothermal metasomatic origin.

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Loci of Orebodies, the Bupyeong Silver Deposits (부평은광상(富平銀鑛床)의 광체배태장소(鑛體胚胎場所))

  • Suh, Kyu-Sik;Park, Hee-In
    • Economic and Environmental Geology
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    • v.20 no.2
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    • pp.97-106
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    • 1987
  • The geology of the Bupyeong mine area is consisted of Precambrian Gyeonggi gneiss complex and Mesozoic igneous rocks; i.e., pyroclastic rocks, intrusive breccia, granite and felsic porphyries which were formed during a Jurassic to early Cretaceous resurgent caldera evolution. Granites are not observed on the surface and in the underground of the mine. Bupyeong silver deposits occur as stockworks of base metal sulfides- minor silver minerals-quartz - carbonate veinlets, hosted by pyroclastic rocks and intrusive breccia at the southwestern margin of the caldera. Silver occurs mainly as native silver, and other silver minerals, minor in quantity, are argentite, tetrahedrite-freibergite, pyrargyrite, polybasite, canfieldite and dyscrasite. The average grade of silver ore is about 180g/t Ag. Discrimination of silver ore from the country rocks depends largely on the chemical analyses of rock samples taken every two meters from tunnels, diamond-drilling cores and mining stopes, because silver minerals are hardly observed in the ore by crude eye, and silver orebodies do not properly coincide with the concentrated zone of base metal sulfides which were precipitated at the earlier stage than the stage of precipitation of native silver. General characteristics of the loci of the silver orebodies are as follows; (1) The host rocks of orebodies are pyroclastic rocks and intrusive breccia. (2) Many of the orebodies are distributed around Gyeonggi gneiss complex. Especially where the paleotopography of gneiss complex shows a gradual slope, the basal stratigraphic horizon of the pyroclastic rocks unconformably overlying the gneiss complex offered a favorable loci of high grade ore. (3) $N5^{\circ}W$ to $N15^{\circ}$ E-striking faults played an important role in the localization of the orebodies. (4) Conduits of intrusive breccia within the gneiss complex, through which the intrusive breccia intruded into the upper pyroclastic rocks, exist beneath most of the main orebodies. This suggests that the conduits of intrusive breccia served as channelways for the migration of ore fluids.

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Preparation of Sodiumisocyanate and its Analyzing Method in the Presence of Impurities $Na_2CO_3$, Urea, and Biuret (Sodium Isocyanate의 제법 및 $Na_2CO_3$, Urea, Biuret 혼재시 그의 정량분석법에 관한 연구)

  • 국채호
    • YAKHAK HOEJI
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    • v.7 no.2_3
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    • pp.67-71
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    • 1963
  • Studies the reaction mechanism and optimal reaction condition of the process of preparing sodium isocyanate, by means of heating of sodium carbonate and urea. Proposing, at the sametime, the quantitative analyzing method of sodium isocyanate in the presence of impurities of $Na_{2}CO_{3}$, urea and biuret. 1. Sodium isocyanate could be prepared by means of heating reaction of sodium carbonate and urea. 2. Adding urea into the heated sodium carbonate is reasonable. 3. Quantitative analysis of sodium isocyanate in the presence of impurities, $Na_{2}CO_{3}$, urea and biuret could be done by the following method:-adding nitrobarite solution into sample solution in order to remove $CO_{3}"$ and neutralize the solution, filtering off $BaCO_{3}$, and then precipitating isocyanate as a silver salt, filtering off AgNCO, and then, titrating remaining $AgNO_{3}$ with $NH_{4}SCN$, (indicator $FeNH_{4}(SO_{4})_{2})$/TEX>

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New record of 21 ciliate species(Protozoa, Ciliophora) from South Korea

  • Omar, Atef;Jung, Jae-Ho
    • Journal of Species Research
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    • v.10 no.3
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    • pp.301-320
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    • 2021
  • During a field survey of indigenous Korean ciliates, we collected 21 unrecorded species from aquatic (freshwater and brackish water [salinity about 1.0‰] samples) and terrestrial(moss and soil samples) habitats. The morphology of these species was studied based on live observation, protargol, silver carbonate and silver nitrate impregnation, and scanning electron microscope. These species belong to seven classes as follows: 1) class Heterotrichea - Blepharisma seculum; 2) class Spirotrichea - Birojimia terricola, Bistichella variabilis, Deviata bacilliformis, Oxytricha paragranulifera, Parabistichella cf. variabilis, Steinia sphagnicola, Stichotricha aculeata, Stylonychia cf. notophora, and Tetmemena bifaria minima; 3) class Armophorea - Metopus es; 4) class Litostomatea - Acropisthium mutabile, Pseudomonilicaryon japonicum, and Rimaleptus alpinus; 5) class Phyllopharyngea - Podophrya bivacuolata; 6) class Nassophorea - Drepanomonas pauciciliata; and 7) class Oligohymenophorea - Dexiostoma campylum, Frontonia atra, Histiobalantium natans viridis, Opisthonecta minima, and Tetrahymena rostrata. Here, we provide a brief diagnosis and remark for each species.

Morphogenesis of Marine Ciliate Pelagostrobilidium (Ciliophora: Oligotrichia) (해산 섬모충 Pelagostrobilidium simile (Ciliophora: Oligotrichia)의 형태 형성)

  • Ma Hongwei;Choi Joong Ki
    • Animal Systematics, Evolution and Diversity
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    • v.21 no.1
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    • pp.21-30
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    • 2005
  • The morphogenesis of the marine ciliate, Pelagostrobilidium simile Song and Bradbury, 1998, was investigated using pyridine silver carbonate impregnation. The morphogenesis of P. simile is of hypoapokinetal mode. The oral primordium of P. simile commences slightly below the external membranelles (EM) with the proliferation of an anarchic field. Somatic ciliature in proter and opisthe of P. simile are derived from the old structure with the proliferation of the basal bodies during the dividing process. Parental oral apparatus of P. simile is inherited by the proter, and no reorganization of oral apparatus was observed in the parental oral infraciliature.