• Journal of Powder Materials
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• v.25 no.2
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• pp.165-169
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• 2018

Rare earth elements (REEs) are considered to be vital to modern industry due to their important roles in applications such as permanent magnets, automobile production, displays, and many more. The imbalance between demand and supply of REEs can be solved by recycling processes. Regarding the needs of industry and society, the International Organization for Standardization, Technical Committee 298 (ISO/TC298) Rare Earths has been recently launched for developing international standards on rare earth elements. In accordance with the suggestion of its constituents, it is tentatively working to develop the appropriate standards under five working groups (WG) on terms and definitions (WG1), element recycling (WG2), environmental stewardship (WG3), packaging, labelling, marking, transport, and storage (WG4), and testing analysis (WG5). The scope and structure of ISO/TC298 on the topic of rare earths is discussed in this document.

• Textile Coloration and Finishing
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• v.24 no.4
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• pp.247-252
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• 2012

The objective of this study was to find an appropriate method and process for protecting the green color in bamboo leaves and subsequent extraction of the green colorants, chlorophyll. Various inorganic salts including cupric sulfate, ferric sulfate, and zinc chloride were employed as green color protectors. Accordingly, the effects of metal salts and treatment conditions on color protection were investigated to find appropriate protector and conditions. And also, the efficacy of bamboo colorants as a natural green dye was evaluated through dyeing and colorfastness tests. Antimicrobial activity of dyed fabrics was measured by shake flask method in terms of bacterial reduction rate using Staphylococcus aureus(ATCC 6538). On the basis of experimental results for stabilizing bamboo leaves colorants, it was confirmed that Cu was the most appropriate metal type considering dye uptake, photostability and light fastness, and its optimum concentration was 0.025%. After the stabilization, the colorants were extracted efficiently at NaOH aqueous solution of 1.00%. It was concluded that bamboo leave has a high potentiality as new resources to produce a natural green dye with antimicrobial functionality.

• Journal of Powder Materials
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• v.29 no.3
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• pp.252-261
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• 2022

Cobalt is a vital metal in the modern society because of its applications in lithium-ion batteries, super alloys, hard metals, and catalysts. Further, cobalt is a representative rare metal and is the 30th most abundant element in the Earth's crust. This study reviews the current status of cobalt extraction and recycling processes, along with the trends in its production amount and use. Although cobalt occurs in a wide range of minerals, such as oxides and sulfides of copper and nickel ores, the amounts of cobalt in the minerals are too low to be extracted economically. The Democratic Republic of Congo (DRC) leads cobalt mining, and accounts for 68.9 % of the global cobalt reserves (142,000 tons in 2020). Cobalt is mainly extracted from copper-cobalt and nickel-cobalt concentrates and is occasionally extracted directly from the ore itself by hydro-, pyro-, and electro-metallurgical processes. These smelting methods are essential for developing new recycling processes to extract cobalt from secondary resources. Cobalt is mainly recycled from lithium-ion batteries, spent catalysts, and cobalt alloys. The recycling methods for cobalt also depend on the type of secondary cobalt resource. Major recycling methods from secondary resources are applied in pyro- and hydrometallurgical processes.

• Resources Recycling
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• v.22 no.3
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• pp.73-80
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• 2013

Metal prices are rapidly rising due to increasing demand of metals and limited available resources according to the industrial requirement. As a result, securing a stable supply of these metal resources has been recognized as a core element of national competitiveness and sustained economic growth. In the case of magnesium and its alloys which are entirely depending on import, low-grade magnesium scraps from end-of-life vehicles and 3C(Camera, Computer, Communication) parts and magnesium wastes such as sludge and dross generated during melting process are hardly recycled. Accordingly, the development and commercialization of recycling technology of low-grade magnesium scrap is desperately needed to improve efficiency of resource circulation and to establish the required proprietary of resource metal supply and demand. In this study, papers and patents on recycling technologies of waste magnesium were analyzed. The range of search was limited in the open patents of USA (US), European Union (EP), Japan (JP), Korea (KR) and SCI journals from 1974 to 2012. Patents and journals were collected using key-words searching and filtered by filtering criteria. The trends of the patents and journals was analyzed by the years, countries, companies, and technologies.

• Resources Recycling
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• v.20 no.5
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• pp.64-68
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• 2011

The typical properties of manganese nodules are its high porosity and high specific surface area and manganese in nodules is existed as ${\delta}$-MnO$_2$. These properties suggest that manganese nodules ran be used as an adsorbent for heavy metal ions. This study investigated the practical applicability for the removal of copper ions in the waste water by manganese nodules as an adsorbent using fixed column and fix bed systems. Manganese nodules of 1kg (size 1-3 cm) can absorb 4.0g Cu in fixed column system and 2.3g Cu in fixed bed system from waste water for 3 hours respectively.

• Journal of Haehwa Medicine
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• v.13 no.2
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• pp.169-178
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• 2004

Now many sustitution and false articles is used in korea instead of mudanpi. To use mudanpi correctly, we will make a quilitative certificational plan of mudanpi to investigate all of lieraturea, records and documents. And we could reach conclusions as folloews. 1. Source Source of mudanpi is cortex of Paeonia suffruticosa Andrews(Family:Ranunculaceae) in korea and china. It needs an attention to distinguish into because there is a substitute and a rank in china. 2. process We have to work before harvesting fresh roots is dry perfectly. If outer skin dried moisture a little, cut off outer skin vertically at sunny day, remove a heart and sever, immedietly dry. When working, we have to take care of because of easy discoloration with moisture. 3. Quality (1) Functional standards A diameter is large, it do not exist a heart of wood, a bark is thick and powdery. Section surface is light white color and rich odor with many light crystals. (2) Physicochemical stamdards We think that it needs to raise a contant of paeonol at all kinds of testing standards. A contant of paeonol is at least more than 2.5%. A part of wood indicate a heart of wood which has no medical effects, but is a relatively heavy part. So a standart of wood must be lowered sifnificantly less than 1.0%. It must be content of ash is less than 6.0%, Content of acid-nonsoluble ash is less than 1.0%. A fixed quantity of paeonol is more than 2.5%. Contens of heavy metal has to detect less than 30 ppm and there is no reminding agriculural medince.

• Journal of Haehwa Medicine
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• v.13 no.2
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• pp.197-204
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• 2004

Now many sustitution and false articles is used in korea instead of chenpi. To use chenpi correctly, we will make a quilitative certificational plan of chenpi to investigate all of lieraturea, records and documents. And we could reach conclusions as folloews. 1) Source In china source of Chen-pi is pericarp of citrus reticula Blanco(Family;rutaceae)and in korea source of Chen-pi is pericarp of citrus unshiu Markovich(Family;rutaceae). Though source of both countries are not same, it has no problems because of containing family plants and culture variants. 2) Harvesting and processing After the peel attained full growth, wash cleanly in water. And dry in shade or in low temporature at state of eliminating pericarp. 3) Quality (1) Functional standards Exocarp is soft and clear yellow with numerous oil sports. The less white mesocarp is the better. (2) Physicochemical standards We need to suggest new standards about hesperidin to various conditions by processing methods and storing time. The loss on drying is less than 13.5%. Ash content is less than 4.0%. A standard capacity of hesperidin is more than 4.0%. The content of heavy metal is less than 30 ppm. We can not detect reminding agricultural medicines.

• Journal of the Korea Concrete Institute
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• v.25 no.5
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• pp.539-546
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• 2013

Cement industry in 1997 began to use industrial waste in cement factory for purpose of resource recycling. However recently, environmental hazard of the cement in accordance with recycling of industrial waste have been raised a problem by contamination around the cement factory and heavy metal leaching in cement. In particular, the presence of $Cr^{6+}$ in cement has become a critical issue, the studies for minimizing of $Cr^{6+}$ in cement have been performed. But, in domestic, most of the research on heavy metal leaching was carried out from the perspective of the cement. Environmental safety assessment in terms of concrete is needed because cement is used to the concrete material. Therefore, this paper was evaluated heavy metals leaching of deteriorated concrete by severe conditions. test result showed that $Cr^{6+}$ were not detected from all the variables.

• Journal of environmental and Sanitary engineering
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• v.10 no.2
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• pp.1-12
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• 1995

Under accelerated industrial developments environment pollution comes out to be very stirious. Especially the ions of heavy metal from wastewater, even if they are minimal, accumulated in ecology circle and do finally injury to human health. The general process for removal of heavy metals include coagulation and following sedimentation, ion -exchange and active carbon adsorption and sedimentation that applicate in popular, needs the expense of coagulant the additional treatment of sludge on the general process of coagulation and sedimentation. It is also a serious problem that the second pollution caused by coagulant. However chelating adsorption that uses natural chelating high- molecular compound has not pollution problem Among chelating high- molecules, the diminishing chitin that contained in crustaceans as crawfish and crab in our country with affluent water resources are easy to get. So it is advantageous to use this ubiquitous material for removing heavy metals because we could reuse natural resource. In this research, the author tested the effectiveness of the adsorption and removal of heavy metal ions by chitin and its derivatives. Chitin and cellulose became beads and used as flocculant, in this test. The results are as follows . First, bead showed higher removal ratio than powder in the comparative test on adsorbents such as chitin, chitosan and cellulose. Secondly, in the variety test by the kinds of adsorbent and time. chitosan bead and cellulose bead that showed the highest removal ratio. One hour need to remove the ions of heavy metal. Thirdly, the results of the adsorption degree test by pH revealed high removal ratio adsorption of chitin, cellulose and chitosan bead in alkalin condition but chitosan bead in acidic condition.

• Journal of Korea Technology Innovation Society
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• v.11 no.2
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• pp.171-193
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• 2008

Every country of the world in the 21st century is going to push forward the policy protecting their intellectual property right, and international movement to protect their intellectual right is still more strengthened. Under these situations, the firm is required to seek for more efficient methods of technology security and business management while the existence of business itself is at risk. The control of intellectual properties in business should be considered in the patent management. In the company, the industrial property right should be into one of the management resource, and its importance has great influence on the existence of the company. The information in patent data can be used for strategic planning purposes. This study systematically evaluates the patenting behaviour of sample of 27 business firms within the Korean metal industry. Utilizing the patent application data between 2000 and 2005, the relationship between these patenting management and company performance is analysed. This study showed that patent activity per employee and labor productivity are positive relationship, but patent activity per employee and firm size are negative relationship. Since a positive relationship between patenting and company performance could be shown, patent activity gains important as a instrument for R&D planning.