• Korean Journal of Materials Research
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• v.23 no.7
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• pp.399-403
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• 2013

The purpose of this study is to investigate the coloration characteristics by identifying the factor affecting red coloration of copper red glaze in traditional Korean ceramics. This study analyzed the characteristics of the reduction-fired copper red glaze by using XRD, Raman spectroscopy, EDX and UV-vis spectroscopy. As a result of XRD analysis, the glaze completely melted and amorphous glass appeared overall, and the characteristic peak of metal Cu was shown together. In addition, as a result of Raman analysis, the characteristic bands of CuO and $Cu_2O$ were shown together. The distribution of component elements was observed by EDX. As a result, copper(Cu) were distributed throughout the glaze. Thus, it was shown that copper red glaze appeared the best red coloration because metal Cu, CuO and $Cu_2O$ evenly existed throughout glaze in particle colloidal state. The chroma value of the copper red glaze was CIE $L^*$ 30.07, $a^*$ 13.65, $b^*$ 3.72. Wine-Red Solution was shown by Dark Graish Red coloration.

• Journal of the Korean Ceramic Society
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• v.50 no.6
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• pp.518-522
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• 2013

This study investigatesthe coloration mechanism by identifying the factor that affects thered coloration of copper red glazesin traditional Korean ceramics. The characteristics of the reduction-fired copper red glaze's sections are analyzed using an optical microscope, Raman spectroscopy, scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDX). The sections observed using an optical microscope are divided into domains of surface, red-bubble, and red band. According to the Raman micro spectroscopy analysis results, the major characteristic peak is identified as silicate in all three domains, and the intensity of $Cu_2O$ increases toward the red band. In addition, it is confirmed that the most abundant CuO exists in the glaze bubbles. Moreover, CuO and $Cu_2O$ exist as fine particles in a dispersed state in the surface domain. Thus, Cu combined with oxygen is distributed evenly throughout the copper red glaze, and $Cu_2O$ is more concentrated toward the interface between body and glaze. It is also confirmed that CuO is concentrated around the bubbles. Therefore, it is concluded that the red coloration of the copper red glaze is revealed not only through metallic Cu but also through $Cu_2O$ and CuO.

• Journal of Conservation Science
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• v.27 no.1
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• pp.31-40
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• 2011

Copper-red (Dongwha, Jinsa) is Korean traditional inorganic pigment used for red-coloring on the porcelain surface during Goryeo and Joseon Periods. Trace amounts of copper-red porcelains are handed down because of the technical difficulty of making and coloring of the pigment. It is known that copper ore sources were extensively distributed in Korea according to old literatures and some of them are still producing copper ore at this present. Main types of copper-bearing mineral in Korea are chalcopyrite ($CuFeS_2$) and malachite ($Cu_2CO_3(OH)_2$), and they are easily collected from the ground surface. This means Korea had geographical and economic geological advantages for supplying raw material of the pigment. These two minerals showed good red-coloring in color test for porcelain pigment. As a coloring element, copper showed micro size less than $5{\mu}m$ in diameter in glaze matrix. The dispersion of copper particle is the most decisive factor for red chromaticity of copper-red porcelain, as well as copper content of the pigment.

• Economic and Environmental Geology
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• v.7 no.4
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• pp.157-173
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• 1974

The Red Hill deposit of the Dongjom Copper Mine is the most promising deposit of the mine and under intensive exploration at present although there are eight more deposits of vein type. With total 2160m drilling of 9 holes completed and 400m drilling on two holes underway, the nature of the Red Hill deposit has come more clear. The copper content in the whole ore body is meager so far as the exploration done up to present indicates, but there are evidences that mineralization covers all over the granodiorite cupola at the Red Hill area. The petrological work and assay on the samples taken by the writers indicate that granodiorite rocks can be divided into fresh zone and alteration zone. Alteration zone consists of potassic and argillic zones accompanyied by silicification zone on basis of Lowell and Guilbert model Argillic zone has closely related with a mineralization in the Red Hill deposit. It has been cleared that the alteration acompanyied with the mineralization took place not only &long vertical fissures but also in the irregular lateral zone, the nature of which is unknown. Judging from the results of exploration and petrochemical study on the Red Hill deposit which is imbedded in a southern part of the granodiorite cupola, it can be concluded by the writer's opinion that the Red Hill deposit is possibly a porphyry copper deposit, because the shape of the ore body, mineral zoning and paragenesis and wall rock alteration resemble to those of typical porphyry copper deposits. It is the writers' opinion that more exploration work is required so as to evaluate the deposit.

• Economic and Environmental Geology
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• v.30 no.4
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• pp.379-393
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• 1997

Geology of the Zbezkazgan copper deposit in Kazhkstan is mainly composed of Permian and Carboniferous sedimenary rocks in which copper minerals are mainly contained in grey sandstone of Carboniferous age. There are 28 layers of copper ore bodies in Zbezkazgan suite. Thickness of the ore bodies ranges from one to 35 meters, grade of the crude ore ranges from 2 to 5 wt % Cu and the extension of the orebodies is 5 to 7 km. Microscopic study on specimens from the Zbezkazgan ore deposit has exposed clues to understand the origin of this deposit. Alternatively deposited grey sandstone and red sandstone are mainly composed of quartz and feldspar grains. A big difference between the grey sandstone and the red sandstone is in grain size, the former is larger than the latter. Chalcocites as main copper minerals have cemented through grain boundary. It is assumed that quartz, feldspar and copper were derived from granitoid in which copper mineralization had taken place before exposing to weathering. The chalcocites were precipitated by a sudden change of geochemical condition (Eh, pH, temperature, etc.) of fluid which had carried quartz, feldspars, copper ions and sulphate during formation of grey sandstones. The copper ions and sulphate were stable in fluid during sedimentation of oxidation environment, however, the copper ions were no more stable at the reduced environment and changed to stable forms to precipitate copper minerals by reaction of copper ions and hydrogen sulfides. This chemical precipitation of copper minerals in the sandstone attributes to the assumption of hydrothermal origin on this sedimentary origined deposit.

• Journal of Veterinary Clinics
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• v.15 no.2
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• pp.455-459
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• 1998

Ten sheeps from one farm had sudden onset of anorexia, jaundice and hemoglobinuria and died within 3 days after showing clinical signs during 3 months period. Postmortom examination was performed on one case and copper concentrations in the livers kidney and serum of the necmpsied minim were analysed. Grossly, the conjunctive, subcutaneous tissue and abdominal fat were generally icteric. The liver was enlarged with yellowish orange in color. The kidney was enlarged with dark red in color and the urinary bladder was filled with dark red urine. Histopathologically, centrilobular hepatocellular necrosis, neutrophilic infiltrations bile stasis and aggregation of fine granules-laden macrophages in the portal area were noted in the liver. Most of the Bowman's spaces and renal tubules were filled with homogenous eosinophilic fluid. Extramedullary hematopoiesis was noted in the submandibular lymph node. Copper concentrations in serum, liver and kidney of the necropsied animal were 25.0, 2732.8 and 471.3 ppm respectively. Based on the gross and histopathological findings and the high copper concentrations in the organs, this case was diagnosed as chronic copper toxicosis. Possible etiology on this outbreak is also discussed.

• Economic and Environmental Geology
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• v.44 no.1
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• pp.11-20
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• 2011

Geological survey on the occurrence of copper oxide in Suparaura area around Abancay in the south-central part of Peru had been carried out. Geology of the area is composed of granitoids such as granodiorite, tonalite and andesitic porphyry related to Tertiary igneous activity, Ferrobamba formation with Cretaceous limestone and sandstone in descending order. Red sandstone is widely distributed and emplaced with their attitude of $N70^{\circ}W$ strike and $60^{\circ}NE$ dip. Copper oxides were mineralized along the bedding plane of red sandstone with maximum width of 30 cm. Ore-body structure bounding red sandstone strata have different occurrence characteristics with generally known porphyry system in terms of alteration, mineral assemblage and occurrence mode. Therefore, it is thought to be stratiform sediment-hosted copper (SSC) deposits genetically corresponding to Mississippi-valley type from preliminary study.

• Journal of Microbiology and Biotechnology
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• v.31 no.2
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• pp.233-239
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• 2021

Cyanobacteriochromes (CBCRs) are phytochrome-related photoreceptor proteins in cyanobacteria and cover a wide spectral range from ultraviolet to far-red. A single GAF domain that they contain can bind bilin(s) autocatalytically via heterologous recombination and then fluoresce, with potential applications as biomarkers and biosensors. Here, we report that a novel red/green CBCR GAF domain, SPI1085g2 from Spirulina subsalsa, covalently binds both phycocyanobilin (PCB) and phycoerythrobilin (PEB). The PCB-binding GAF domain exhibited canonical red/green photoconversion with weak fluorescence emission. However, the PEB-binding GAF domain, SPI1085g2-PEB, exhibited an intense orange fluorescence (λabs.max = 520 nm, λfluor.max = 555 nm), with a fluorescence quantum yield close to 1.0. The fluorescence of SPI1085g2-PEB was selectively and instantaneously quenched by copper ions in a concentration-dependent manner and exhibited reversibility upon treatment with the metal chelator EDTA. This study identified a novel PEB-binding cyanobacteriochrome-based fluorescent protein with the highest quantum yield reported to date and suggests its potential as a biosensor for the rapid detection of copper ions.

• Journal of Biosystems Engineering
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• v.28 no.3
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• pp.209-216
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• 2003

Red pepper calyx cutting devices using a impacting force by a rotational cutter were devised and tested to obtain the fundamental data for development of a calyx removal unit. Fresh red peppers with 80∼87%(w.b.) of initial moisture contents were used as experimental materials. Square and wire type of rotational cutters were used to cut the red pepper calyx and the fresh red peppers were fed into the device both manually and automatically. Three rotational speeds of 250, 500, 700rpm were selected for a square, and 1000, 1500, 1800rpm for a wire type cutter respectively. Four types of red pepper fixing unit were used in manual feeding. The cutting rate of the square type cutter was over 50% regardless the shape and specification of the cutter. For the wire type cutter, the copper wire and nylon chord could not be applied to cut the red pepper calyx because of the low cutting rate. But for the fine wire, the cutting rate was higher and the cutting mechanism was more steady than copper wire and nylon chord. The cutting rate of automatic feeding and wire type cutting unit was about 70% for all levels of the rotational speed. The cutting rate was highly related to the impacting point of red pepper in carrier box. To increase the cutting rate using the rotational cutter, a proper device and mechanism was required to keep the impacting point consistently.

• Journal of Microbiology and Biotechnology
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• v.24 no.4
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• pp.534-544
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• 2014

The effects of microbial iron reduction and oxidation on the immobilization and mobilization of copper were investigated in a high concentration of sulfate with synthesized Fe(III) minerals and red earth soils rich in amorphous Fe (hydr)oxides. Batch microcosm experiments showed that red earth soil inoculated with subsurface sediments had a faster Fe(III) bioreduction rate than pure amorphous Fe(III) minerals and resulted in quicker immobilization of Cu in the aqueous fraction. Coinciding with the decrease of aqueous Cu, $SO_4{^{2-}}$ in the inoculated red earth soil decreased acutely after incubation. The shift in the microbial community composite in the inoculated soil was analyzed through denaturing gradient gel electrophoresis. Results revealed the potential cooperative effect of microbial Fe(III) reduction and sulfate reduction on copper immobilization. After exposure to air for 144 h, more than 50% of the immobilized Cu was remobilized from the anaerobic matrices; aqueous sulfate increased significantly. Sequential extraction analysis demonstrated that the organic matter/sulfide-bound Cu increased by 52% after anaerobic incubation relative to the abiotic treatment but decreased by 32% after oxidation, indicating the generation and oxidation of Cu-sulfide coprecipitates in the inoculated red earth soil. These findings suggest that the immobilization of copper could be enhanced by mediating microbial Fe(III) reduction with sulfate reduction under anaerobic conditions. The findings have an important implication for bioremediation in Cu-contaminated and Fe-rich soils, especially in acid-mine-drainage-affected sites.