• Economic and Environmental Geology
• /
• v.22 no.4
• /
• pp.303-314
• /
• 1989

The electrum-silver-sulfide mineralization of the Geojae island area was deposited in three stages (I, II, and carbonate) of quartz and calcite veins that crosscut Late Cretaceous volcanic rocks and granodiorite(83 m.y.). Stages I and II were terminated by the onset of fractunng and breCCIation events. Fluid inclusion data suggest that the gold-sulfide-bearing stages I and II each evolved from an initial high temperature( near $370^{\circ}C$) to a later low temperature(near $200^{\circ}C$). Each of those stages represented a separate mineralizing system which cooled prior to the onset of the next stage. The relationship between homogenization temperature and salinity in stages I and II suggests a complex history of boiling, cooling and dilution. Evidence of boiling indicates a pressure of < 100 bars, corresponding to a depth of 500 to 1,250m assummg hthostatlc and hydrostatic pressure regimes, respectively. Fluid inclusion and mineralogical evidence suggest that the electrum-silver mineralization was deposited at a temperature of $220-260^{\circ}C$ from ore fluids with salinities between 1.9 and 8.1 equivalent wt.% NaCl. Total sulfur concentration is estimated to be $10^{-3}$ to $10^{-4}$ molal. The estimated $fs_2$ and $fo_2$ range from $10^{-11.8}$ to $10^{-14}$ atm and $10^{-35}$ to $10^{-36}$ atm, respectively. The chemical conditions indicate that the dominant sulfur species in the ore forming fluids was a reduced form($H_2S$). Rapid cooling and dilution of ore-forming fluids by mixing with less-evolved meteoric waters led to gold-silver deposition through the breakdown of the bisulfide complex($Au(HS)_2$) as the activity of $H_2S$ decreased.

• The Journal of Korean Academy of Prosthodontics
• /
• v.47 no.4
• /
• pp.424-434
• /
• 2009

Statement of problem: Problems such as loosening and fractures of retained screws and fracture of implant fixture have been frequently reported in implant prosthesis. Purpose: Implant has weak mechanical properties against lateral loading compared to vertical occlusal loading, and therefore, stress analysis of implant fixture depending on its material and geometric features is needed. Material and methods: Total 28 of external hexed implants were divided into 7 of 4 groups; Group A (3i, FULL $OSSEOTITE^{(R)}$Implant), Group B (Nobelbiocare, $Br{\aa}nemark$ $System^{(R)}$Mk III Groovy RP), Group C (Neobiotec, $SinusQuick^{TM}$ EB), Group D (Osstem, US-II). The type III gold alloy prostheses were fabricated using adequate UCLA gold abutments. Fixture, abutment screw, and abutment were connected and cross-sectioned vertically. Hardness test was conducted using MXT-$\alpha$. For fatigue fracture test, with MTS 810, the specimens were loaded to the extent of 60-600 N until fracture occurred. The fracture pattern of abutment screw and fixture was observed under scanning electron microscope. A comparative study of stress distribution and fracture area of abutment screw and fixture was carried out through finite element analysis Results: 1. In Vicker's hardness test of abutment screw, the highest value was measured in group A and lowest value was measured in group D. 2. In all implant groups, implant fixture fractures occurred mainly at the 3-4th fixture thread valley where tensile stress was concentrated. When the fatigue life was compared, significant difference was found between the group A, B, C and D (P<.05). 3. The fracture patterns of group B and group D showed complex failure type, a fracture behavior including transverse and longitudinal failure patterns in both fixture and abutment screw. In Group A and C, however, the transverse failure of fixture was only observed. 4. The finite element analysis infers that a fatigue crack started at the fixture surface. Conclusion: The maximum tensile stress was found in the implant fixture at the level of cortical bone. The fatigue fracture occurred when the dead space of implant fixture coincides with jig surface where the maximum tensile stress was generated. To increase implant durability, prevention of surrounding bone resorption is important. However, if the bone resorption progresses to the level of dead space, the frequency of implant fracture would increase. Thus, proper management is needed.

• Parasites, Hosts and Diseases
• /
• v.29 no.3
• /
• pp.245-258
• /
• 1991

In order to determine the antigenic localization in the tissues of the adult Metagonimus yokegawai, immunogoldlabeling method was applied using serum immunoglobulins (IgG) of cats which were infected with isolated metacercariae from Plecoglossus altivelis. The sectioned worm tissue was embedded in Lowicryl HM 20 medium and stained with infected serum IgG and protein A gold complex (particle size: 12 nm) , It was observed by electron microscopy at each tissue of the worm. The gold particles were observed on the tegumental syncytium as well as cytoplasm of tegumental cells and epithelial lamella of the caecum. The gold particles were not observed on the basal lamina of the tegument, interstitial matrix of the parenchyma, the muscle tissue and mitochondria of the tegument. The gold particles were specifically labeled in the secretory granules in the vitelline cells. They were also labeled on the lumen of bladder and egg shell. The above findings showed that antigenic materials in the tissue of adult worms were specifically concentrated on the tegumental syncytium as well as cytoplasm of tegumental cells and epithelial lamella of the caecum.

• Conservation Science in Museum
• /
• v.24
• /
• pp.1-16
• /
• 2020

This paper presents the process of re-conservation and the results of research on the production method of the Iron Sword with Ring Pommel with Three-Pointed Leaf Decoration, one of the excavation findings from Tomb No. 55 in the Dalseong Ancient Tomb Complex in Daegu. This iron sword is a double weapon with two large swords housed within a single sheath. Four smaller swords are attached to the surface of the sheath, two on the upper portion and the other two below. It is the only such two-in-one weapon excavated intact thus far from an ancient Korean tomb. The records show that it underwent conservation treatment twice in the past. In this study, it was subjected to conservation treatment again to replace the stiffener in some cracking areas, and its material, composition, and production method were analyzed by CT, XRF analysis, and stereoscopic microscopy. The sword is mainly made of copper, but the golden component contains both gold and mercury, which suggests that the copper was plated in gold using mercury amalgamation. The examination of the production methods indicates that it was intended more to demonstrate the authority of its owner rather than to serve any practical use. The two upper small swords on the sheath were made in the same manner as the main swords, and the two small lower swords were cut from a single metal sheet. The sheath was made by cutting two metal sheets. Supports were used to attach the two small swords to the upper portion of the sheath, while the lower portion of the sheath was slit to allow the other two small swords to be inserted into it. The ring pommels of the main swords have a three-pointed leaf decoration. As for the other designs, the handle of the main sword features a series of semicircles, the decorative bands on the sheath have waves in dots, and the fish tail of the sheath shows diagonal lines of dots.

• Applied Microscopy
• /
• v.37 no.4
• /
• pp.249-258
• /
• 2007

The Pancreatic islet are the clusters of endocrine cells scattered through out the exocrine pancreas. Transplantation of a sufficient pancreatic islets can normalize blood glucose level so that may prevent devastating complications of type I diabetes(IDDM) and other side effects of the IDDM. Recently, there are several approaches to transplant sufficient pancreatic islet, and it was comprised in increase or regeneration of the endogenous $\beta$-cell mass from donor's pancreas, but relatively few studies have been devoted to the morphological characters of the isolated and 3 day cultured pancreatic islets. We investigated morphological pattern of intracellular structure of isolated and 3 day cultured pancreatic islets. The morphological characters of the pancreatic islets were observed by scanning electron microscope and transmission electron microscope, and insulin distribution of the each islets were observed by transmission electron microscope, and were labeled with insulin antibody. Intracellular structures including nuclei, mitochondria, RER, Golgi complex and many secretory granules were normally appeared in the isolated pancreatic islets which was extracted immediately dornor's pancreas, however, There is a significant morphological changes between the 3 day cultured pancreatic islets and isolated islets. 3 day cultured pancreatic islet's $\beta$-cells had normal nuclei but increased cytoplasm mass and RER and developed Golgi complex. Insulin secretory granules were decreased in numbers rather than isolated pancreatic islet. In this study, the pattern of intracellular structure variation was examined during pancreatic islet culture. Most distinct features are variation of the insulin secretory granules, and developed RER, and dilated golgi complex. Therefore, we suggested that the various change of the morphological characters on cultured pancreatic islets were responsible for the function(biosynthesis and secretion of insulin) and growth. These results were also cultured islets have greater ability to recover and maintain normoglycemia than isolated islet transplantation.

• Journal of the Daesoon Academy of Sciences
• /
• v.42
• /
• pp.167-199
• /
• 2022

A majority of religious orders in Jeungsanism believe in Jeungsan as a spiritual entity or incarnation of Maitreya. However, Daesoon Jinrihoe insists that the destiny of Maitreya lasts for fifty-thousand years and the 'gold (金)' associated with the Maitreya icon (Geumsan-sa Temple) symbolizes the 'Later World.' A different Maitreya icon was produced for Daesoon Jinrihoe's Toseong Training Temple Complex. That icon of Maitreya looks similar to the one at Gwanchok-sa Temple. That is because the icon in Daesoon Jinrihoe has been formed in order to emphasize Maitreya as a symbol different from the one in Geumsan-sa Temple. If the Maitreya icon of Geumsan-sa Temple is a core that symbolizes two figures, Jeungsan and his successor, Jeongsan, who inherited his religious orthodoxy, then the Maitreya icon at Toseong Training Temple Complex is a symbol that suggests faith and religious practice from a more conventional perspective. The Maitreya icon in Geumsan-sa Temple deals with issues of religious orthodoxy whereas the icon at Toseong is related to the prophecies on the redemption of people and the advent of Dao-empowered sages. According to Daesoon Thought, Maitreya is not just the future Buddha. He has already descended on the earth in modern times. Due to Jeungsan's descending on the earth, the incarnation of Maitreya has been accomplished as far as the Daesoon faith is concerned. Henceforth, the true practice of Maitreya reverence in the context of Daesoon Jinrihoe should be focused around a group of devotees who specifically practice Jeungsan's Reordering Works of Heaven and Earth. An attempt to do so will enable the formation of the ideal world aimed upon by Maitreya.

• Journal of the Korean Electrochemical Society
• /
• v.17 no.1
• /
• pp.30-36
• /
• 2014

Redox complexes to transport electrons from enzyme to electrodes are very important part in glucose sensor. Pentacyanoferrate-bound aniline ($Fe(CN)_5$-aminopyridine), was prepared as a potential redox mediator in a glucose dehydrogenase (GDH)-glucose sensor. The synthesized pyridyl-$NH_2$ to pentacyanoferrate was characterized by the electrochemical and spectroscopic methods. A amperometric enzyme-linked electrode was developed based on GDH, which catalyses the oxidation of glucose. Glucose was detected using GDH that was co-immobilized with an $Fe(CN)_5$-aminopyridine and gold nano-particles (AuNPs) on ITO electrodes. The $Fe(CN)_5$-aminopyridine and AuNPs immobilized onto ITO electrodes provided about a two times higher electrochemical response compared to that of a bare ITO electrode. As glucose was catalyzed by wired GDH, the electrical signal was monitored at 0.4 V versus Ag/AgCl by cyclic voltammetry. The anode currents was linearly increased in proportion to the glucose concentration over the 0~10 mM range.

• Proceedings of the Mineralogical Society of Korea Conference
• /
• 2002.10a
• /
• pp.119-136
• /
• 2002

Contrasts in the style of the gold-silver mineralization in geologic and tectonic settings in Korea, together with radiometric age data, reflect the genetically different nature of hydrothermal activities, coinciding with the emplacement age and depth of Mesozoic magmatic activities. It represents a clear distinction between the plutonic settings of the Jurassic Daebo orogeny and the subvolcanic environments of the Cretaceous Bulgugsa igneous activities. During the Daebo igneous activities (c.a. 200-150 (?) Ma) coincident with orogenic time, gold mineralization took place between c.a. 195 and 135 (127 ?) Ma. The Jurassic Au deposits commonly show several characteristics; prominent association with pegmatites, low Ag/hu ratios in the ore-concentrating parts, massive vein morphology and a distinctively simple mineralogy including Fe-rich sphalerite, galena, chalcopyrite, arsenopyrite, Au-rich electrum, pyrrhotite and/or pyrite. During the Bulgugsa igneous activities $(110\~50Ma)$, the precious-metal deposits are generally characterized by such features as complex vein morphology, medium to high AE/AU ratios in the ore concentrates, and diversity of ore minerals including base-metal sulfides, pyrite, arsenopyrite, Ag-rich electrum and native silver nth Ag sulfides, Ag-Sb-As sulfosalts and Ag tellurides. Vein morphology, mineralogical, fluid inclusion and stable isotope results indicate the diverse genetic natures of hydrothermal systems in Korea. The Jurassic Au-dominant deposits (orogenic type) were formed at the relatively high temperature $(about\;300^{\circ}\;to\;450^{\circ}C)$ and deep-crustal level $(4.0{\pm}1.5\;kb)$ from the hydrothermal fluids containing more amounts of magmatic waters $(\delta\;^{18}O_{H2O}\;5\~10\%_{\circ})$. It can. It can be explained by the dominant ore-depositing mechanisms as $CO_2$ boiling and sulfidation, suggestive of hypo- to mesothermal environments. In contrast, the Cretaceous Au-dominant $(l13\~68\;Ma),\;Au-Ag \;(108\~47\;Ma)$ and Ag-dominant $(103\~45\;Ma)$ deposits, which correspond to volcanic-plutonic-related type, occurred at relatively low temperature $(about\;200^{\circ}\;to\;350^{\circ}C)$ and shallow-crustal level $(1.0\{pm}0.5\;kb)$ from the ore-forming fluids containing more amounts of less-evolved meteoric waters$(\delta\;^{18}O_{H2O}\;-10\~5\%_{\circ})$. These characteristics of the Cretaceous precious-metal deposits can be attributed to the complexities in the ore-precipitating mechanisms (mixing, boiling, cooling), suggestive of epi- to mesothermal environments. Therefore, the differences of the emplacement depth between the Daebo and the Bulgugsa igneous activities directly influence the unique temporal and spatial association of the deposit styles.

• Journal of the Korea Society of Computer and Information
• /
• v.25 no.5
• /
• pp.47-56
• /
• 2020

The stock index is used not only as an economic indicator for a country, but also as an indicator for investment judgment, which is why research into predicting the stock index is ongoing. The task of predicting the stock price index involves technical, basic, and psychological factors, and it is also necessary to consider complex factors for prediction accuracy. Therefore, it is necessary to study the model for predicting the stock price index by selecting and reflecting technical and auxiliary factors that affect the fluctuation of the stock price according to the stock price. Most of the existing studies related to this are forecasting studies that use news information or macroeconomic indicators that create market fluctuations, or reflect only a few combinations of indicators. In this paper, this we propose to present an effective combination of the news information sentiment analysis and various macroeconomic indicators in order to predict the US Dow Jones Index. After Crawling more than 93,000 business news from the New York Times for two years, the sentiment results analyzed using the latest natural language processing techniques BERT and NLTK, along with five macroeconomic indicators, gold prices, oil prices, and five foreign exchange rates affecting the US economy Combination was applied to the prediction algorithm LSTM, which is known to be the most suitable for combining numeric and text information. As a result of experimenting with various combinations, the combination of DJI, NLTK, BERT, OIL, GOLD, and EURUSD in the DJI index prediction yielded the smallest MSE value.

• Korean Journal of Food Science and Technology
• /
• v.27 no.3
• /
• pp.306-312
• /
• 1995

In order to know properties in rice starch during storage of rice, rice starch from stored rice(stored at $5^{\circ}C$, R.H. 65% and $30^{\circ}C$, R.H. 85%, for 16 weeks) used in this experiment. Water binding capacity of rice starch increased for 8 weeks, and then it decreased. As the storage period took longer, swelling power and solubility, optical transmittance, blue value, total amylose content and soluble amylose content decreased. For the same periods, changes in rice starch from stored rice$(30^{\circ}C$, R.H. 85%) were made more than those in rice starch at $5^{\circ}C$, R.H. 65%. The granule shape of rice starch, irrespective of storage periods and conditions, didn't make a significant difference. The relative crystallinity of the rice starch by X-ray diffraction didn't distinctly changed till the second week. But, at the fourth week, that by X-ray diffraction significantly decreased, and then slightly decreased. As the storage period took longer, gelatinization temperature, melting temperature and melting enthalpy measured by DSC got higher, but gelatinization enthalpy got lower. For the same storage period, gelatinization temperature, melting temperature, gelatinization enthalpy and melting enthalpy of rice starch stored at $30^{\circ}C$, R.H. 85% made changes more than those of rice starch stored at $5^{\circ}C$, R.H. 65% did.