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A Study on the Resource Recovery of Fe-Clinker generated in the Recycling Process of Electric Arc Furnace Dust (전기로 제강분진의 재활용과정에서 발생되는 Fe-Clinker의 자원화에 관한 연구)

  • Jae-hong Yoon;Chi-hyun Yoon;Hirofumi Sugimoto;Akio Honjo
    • Resources Recycling
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    • v.32 no.1
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    • pp.50-59
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    • 2023
  • The amount of dust generated during the dissolution of scrap in an electric arc furnace is approximately 1.5% of the scrap metal input, and it is primarily collected in a bag filter. Electric arc furnace dust primarily consists of zinc and ion. The processing of zinc starts with its conversion into pellet form by the addition of a carbon-based reducing agent(coke, anthracite) and limestone (C/S control). These pellets then undergo reduction, volatilization, and re-oxidation in rotary kiln or RHF reactor to recover crude zinc oxide (60%w/w). Next, iron is discharged from the electric arc furnace dust as a solid called Fe clinker (secondary by-product of the Fe-base). Several methods are then used to treat the Fe clinker, which vary depending on the country, including landfilling and recycling (e.g., subbase course material, aggregate for concrete, Fe-source for cement manufacturing). However, landfilling has several drawbacks, including environmental pollution due to leaching, high landfill costs, and wastage of iron resources. To improve Fe recovery in the clinker, we pulverized it into optimal -sized particles and employed specific gravity and magnetic force selection methods to isolate this metal. A carbon-based reducing agent and a binding material were added to the separated coarse powder (>10㎛) to prepare briquette clinker. A small amount (1-3%w/w) of the briquette clinker was charged with the scrap in an electric arc furnace to evaluate its feasibility as an additives (carbonaceous material, heat-generating material, and Fe source).

A Study of Radon Reduction using Panel-type Activated Carbon (판재형 활성탄을 이용한 라돈 저감 연구)

  • Choi, Il-Hong;Kang, Sang-Sik;Jun, Jae-Hoon;Yang, Seung-Woo;Park, Ji-Koon
    • Journal of the Korean Society of Radiology
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    • v.11 no.5
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    • pp.297-302
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    • 2017
  • Recently, building materials and air purification filters with eco-friendly charcoal are actively studying to reduce the concentration of radon gas in indoor air. In this study, radon reduction performance was assessed by designing and producing new panel-type activated carbon filter that can be handled more efficiently than conventional charcoal filters, which can reduce radon gas. For the fabrication of our panel-type activated carbon filter, first the pressed molding product after mixing activated carbon powder and polyurethane. Then, through diamond cutting, the activated carbon filter of 2 mm, 4 mm and 6 mm thickness were fabricated. To investigate the physical characteristics of the fabricated activated carbon filter, a surface area and flexural strength measurement was performed. In addition, to evaluate the reduction performance of radon gas in indoor, the radon concentration of before and after the filter passes from a constant amount of air flow using three acrylic chambers was measured, respectively. As a result, the surface area of the fabricated activated carbon was approximately $1,008m^2/g$ showing similar value to conventional products. Also, the flexural load was found to have three times higher value than the gypsum board with 435 N. Finally, the radon reduction efficiency from indoor gas improved as the thickness of the activated carbon increases, resulting in an excellent radon removal rate of more than 90 % in the 6 mm thick filter. From the experimental results, the panel-type activated carbon is considered to be available as an eco-friendly building material to reduce radon gas in an enclosed indoor environment.

A Study on Contact Dermatitis-Causing Substances Concentration in Commercial Oxidative Hair-Coloring Products (유통 산화형 염모제의 접촉성피부염 유발물질 함량 연구)

  • Na, Young Ran;Koo, Hee Soo;Lee, Seung Ju;Kang, Jung Mi;Jin, Seong Hyeon
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.40 no.2
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    • pp.203-214
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    • 2014
  • We measured the contact dermatitis-causing substances concentrations in 28 commercial oxidative hair-coloring products. This study was aimed to provide the fundamental data about oxidative hair-coloring products. We selected 10 oxidation dyes (p-phenylenediamine, toluene-2,5-diamine, m-phenylenediamine, nitro-p-phenylenediamine, p-aminophenol, m-aminophenol, o-aminophenol, p-methylaminophenol, N,N'-bis(2-hydroxyethyl)-p-phenylenediamine sulfate, 2-methyl-5-hydroxyethylaminophenol) and 4 heavy metal (nikel; Ni, chromium; Cr, cobalt; Co, copper; Cu) as contact dermatitis-causing substances. To identify 10 oxidation dyes, hexane-2% sodium sulfite was used for the rapid and simple extraction and ultra performance liquid chromatography (UPLC) analysis was used for simultaneous analysis in 12 minutes. 10 oxidative dyes were detected as indicated on the product packaging and each concentration was lower than prescribed upper concentration limit by pharmaceutical manufacturing standards. And we analysed inductively coupled plasma-optical emission spectrophotometer (ICP-OES) for content search of heavy metal after microwave digestion. The heavy metal average concentration in oxidative hair-coloring products was 0.572 ${\mu}g/g$ for Ni, 3.161 ${\mu}g/g$ for Cr, 2.029 ${\mu}g/g$ for Co, 0.420 ${\mu}g/g$ for Cu, respectively. The average of concentration in powder type (henna) was higher than those of other foam and cream type oxidative hair-coloring products as follows; 1.800 ${\mu}g/g$ for Ni, 10.127 ${\mu}g/g$ for Cr, 7.082 ${\mu}g/g$ for Co, 1.451 ${\mu}g/g$ for Cu. Hair coloring products were classified into the six colors - black, dark brown, brown, dark brown, light brown, red brown and analyzed. Brown color had the highest average concentration of Co and the others had the highest average concentration of Cr.

Cytotoxic Effect of X-irradiation of Mouse Tumor Cells in the Presence of Korean Ginseng Extract (마우스 종양세포의 세포독성에 미치는 인삼 추출액과 방사선조사의 병용 효과)

  • Kwon Hyoung-Cheol;Kim Jin-Ki;Kim Jung-Soo;Choi Dong-Seong
    • Radiation Oncology Journal
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    • v.18 no.3
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    • pp.200-204
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    • 2000
  • Purpose : We already reported the results that aqueous extract of Korean ginseng roots showed a marked cytotoxicity. In this study, we investigated whether combined ginseng product with X-irradiation increase the cytotoxicity of tumor cells than X-irradiation or not. Materials and Methods : Fifty gram of Korean ginseng powder mixed with 1 L of distilled water was extracted with reflux flask under condition of $100^{\circ}C$ for 5 hrs. This aquaous ginseng extract was filtered, centrifuged and then was freezed under condition of $-90^{\circ}C$ for 16-18 hrs. The freezing extract was dried with freeze drier, and then diluted. X-irradiation was given to tumor cells by 6 MeV linear accelerator. The cytotoxicity of ginseng in vitro was evaluated from its ability to reduce the clonogenecity of fibrosarcoma (FSa II) cells. In X-irradiation alone group, each 2, 4, 6 and 8 Gy was given to tumor cells. In X-irradiation with ginseng group, 0.2 mg/mL of ginseng extract was exposed to tumor cells for 1 hour before X-irradiation. Results : The yield for 50 g of ginseng extract which was treated with freezing drier was 3.13 g($6.3\%$). Cytotoxicity In vitro was measured as survival fraction which was judged from the curve, at ginseng concentration of 0.001, 0.01, 0.1 and 1 mg/mL were $0.89\pm0.04$, $0.86\pm0.06$, $0.73\pm0.01$ and $0.09\pm0.02$, respectively. Survival fraction at X-irradiation alone of 2, 4, 6 and 8 Gy were $0.81\pm0.07$, $0.42\pm0.08$, $0.15\pm0.02$, $0.03\pm0.01$, respectively. But, suwival fraction in combined group of X-irradiation and ginseng (0.2mg/ml) at each same radiation dose were $0.28\pm0.01$, $0.18\pm0.03$, $0.08\pm0.02$, $0.006\pm0.002$, respectively (p<0.05). Conclusion : The yield for ginseng extract which was treated with freezing drier was $6.3\%$. Cytotoxicty of Fsa 11 in combined ginseng with X-irradiation group was increased than that of X-irradition alone group, and its enhancing effect seemed to be added.

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Effects of Hemicellulase on Purple Sweet Potato Bread (헤미셀룰레이즈 첨가가 자색고구마 식빵의 품질에 미치는 영향)

  • Kim, Yeon-Ok;Kim, Mun-Yong;Bing, Dong-Joo;Yoon, Eun-Ju;Lee, Young-Ju;Chun, Soon-Sil
    • The Korean Journal of Food And Nutrition
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    • v.27 no.1
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    • pp.22-30
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    • 2014
  • In this study, purple sweet potato bread was prepared by the addition of 0.005%, 0.010%, 0.015% and 0.020% hemicellulase. It's effect on product quality and consumer evaluation were examined. The results showed that the dough pH and total titratable acidity were not significantly different between samples. In the fermentation power of dough expansion, a 0.015% addition sample was the highest between the samples. The bread pH decreased significantly as hemicellulase was increased, whereas. Bread total titratable acidity was significantly decreased. The addition of hemicellulase samples were significantly higher in specific volume and baking loss than the control sample. The moisture content was not significantly different between samples. In colors, the lightness of the control sample was the highest, the redness of the 0.020% addition sample was the lowest while the yellowness of the control was the lowest. The hardness and the fracturability decreased significantly as hemicellulase was increased. The resilience indicated reverse effects. In consumer evaluation, the color and softness were not significantly different between samples. And the hemicellulase addition of samples was higher in flavor than that of the control sample. The overall acceptability was the highest at 5.67 with a 0.010% addition sample. According to these results, the addition of 0.010% hemicellulase in purple sweet potato bread would be the optimum level.

A Study on the Current Status of Prescribed Drugs in Oriental Health Insurance and their Improvement (한방건강보험 약제 투약 실태 및 활성화 방안 연구)

  • Kwon, Yong-Chan;Yoo, Wang-Keun;Seo, Bu-Il
    • The Korea Journal of Herbology
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    • v.27 no.2
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    • pp.1-16
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    • 2012
  • Objective : To investigate the current status of prescription drugs in Oriental medical institutes and to draw up a future plan for the revitalization of Oriental medical health insurance, this survey has been performed. Method : The survey has been made with 321 doctors working at Oriental medical institutes in Daegu and Kyungbuk areas for a period of 3 month from June 1, 2010 until September 1, 2010. Result : 1. When it comes to the current status of the use of herbal drugs in Oriental Health insurance, most of doctors surveyed prescribe insurance drugs, and they prescribe insurance drugs to patients, who are less than 20% of total patients visiting their clinics. 2. The awareness of Herbal Health Care Drugs is investigated. When it comes to the understanding of the difference between insurance drugs(powder type drugs) and granular type drugs, doctors admit that they differ only in one aspect, whether or not their being covered by health insurance. Based on the survey results on the understanding of insurance coverage of granular type drugs, doctors, even though they long for granular type drugs to be accepted as insurance drugs, are worrying whether the number of outpatients might dwindle due to increased insurance co-payments. They also point out that the biggest obstacles in the expansion of the granular type drugs as insurance drugs are the lack of understanding of the government and the objection of the Health Insurance Review and Assesment service (HIRA) for fear of increased insurance claims. 3. Upon investigation on Oriental medicine doctors' understandings of herbal pharmaceutical industry, it is found that doctors' responses on pharmaceutical industry are not all positive ones('new product development and neglect of R&D infrastructure' and 'smallness of industry'). When it is investigated what area needs the greatest improvement in herbal pharmaceutical industry, 'securing sufficient capital, good manufacturing, and strengthening quality control', is the highest. 4. When it is asked what are the most needed in order to improve herbal health insurance medicine, responses such as 'the increase in the accessibility to and the utilization of Oriental medical clinics through the diversification of the means of prescriptions', 'the improvement of insurance benefits(cap adjustments)', 'increase the proportion of high quality medicinal plants', 'the ceiling of co-payments(deductible) at 20,000 won or more', 'expansion of the choices of formulations', 'formulational expansions of tablets and pills', and finally 'admittance and expansion of granular type drug as insurance drug' are the highest. 5. Upon investigating the general characteristics of the current status of the usage of Oriental health care herbal drugs, the followings are observed. First, the frequency of use of health insurance drugs by the doctors who use health insurance with general characteristics shows similar differences in case of total monthly sales amount (p<0.001), average number of daily patients (p<0.05). Secondly, as to the willingness of the expanded usage of insurance drugs, similar differences are observed in case of total monthly sales amount (p<0.05). 6. Upon investigating the general characteristics of the perception of Herbal health care drugs, the followings are observed. First, inspecting general characteristics and insurance claims due to increased co-payments(deductible amount) reveals similar differences in case of working period (p<0.01) and in case of total monthly sales amount (p <0.01). Secondly, inspecting general characteristics and the obstacles that hinder granular type drugs from being accepted as health care insurance drugs shows similar differences in case of working period (p<0.05). 7. Upon investigating the general characteristics of the understanding of Oriental Herbal pharmaceutical companies, the followings are observed. First, opinions on the general characteristics of pharmaceutical companies, when examined with variance analysis, shows similar differences in case of total monthly sales amount (p<0.05). Secondly, when opinions are examined on general characteristics and the problems of herbal pharmaceutical companies, similar differences are found in case of working period (p<0.01) and in case of total monthly sales amount (p<0.001). Lastly, opinions on the general characteristics and reforms of pharmaceutical companies, similar differences are observed in case of working period (p<0.001). 8. Upon investigating the general characteristics of the improvement of insurance Herbal drugs, the followings are observed. First, regarding general characteristics and insurance benefits, similar differences are observed in case of working period (p<0.05), in case of total monthly sales amount (p<0.05), and in case of average number of daily patients (p<0.01). Secondly, opinions on the general characteristics and the needs for the improvement of Herbal insurance drugs are examined in 5 different aspects, which are the approval of granular type drugs as insurance drugs, the expanded practices of the number of prescription insurance drugs, the needs of a variety of formulations, the needs of TFT of which numbers of Oriental medical doctors are members for the revision of the existing system, and the needs of adjusting the current ceiling of the fixed amount and the fixed rate. When processed by the analysis of variance, the results show similar differences in case of average number of daily patients (p<0.01). Conclusion : From the results of this study the first measures to take are, to reform overall insurance benefit system, including insurance co-payment system(fixed rate cap adjustment), to expand the number of the herbal drugs to be prescribed matching with insurance benefit accordingly, and to revitalize herbal medicine insurance system through the change of various formulations. In addition, it is recommended to improve the effectiveness of herbal medicine by making plans to enhance the efficacy of herbal medicine and by enabling small pharmaceutical companies to outgrow themselves.