• 한국염색가공학회지
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• 제19권4호
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• pp.10-17
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• 2007

Chitosan(CS) and cellulose acetate(CA) composite films were prepared using formic acid as a cosolvent by casting, solvent evaporating and neutralization method. This study examines if the blending method, which uses formic acid as a cosolvent is efficient in improving the mechanical properties of CS film, especially wet strength and elongation. Formic acid is an effective cosolvent for the blend of CS and CA. Under wet condition, tensile strength and elongation of the composite films were obviously higher than those of the films made from pure CS. FTIR, DSC, and X-ray diffraction showed that the composite films exhibit a high level of compatibility and that strong interaction between the CS and CA was caused by intermolecular hydrogen bonding. The affinity series of composite film to transition metal ions are Cu(II) > Cd(II) > Cr(III). The adsorption of Cu((II) ion was shown to be highly pH sensitive.

• Journal of Microbiology and Biotechnology
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• 제18권11호
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• pp.1803-1808
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• 2008

For practical application, the stability of permeabilized Ochrobactrum anthropi SY509 needs to be increased, as its half-life of enzymatic denitrification is only 90 days. As the cells become viable after permeabilization treatment, this can cause decreased activity in a long-term operation and induce breakage of the immobilization matrix. However, the organic solvent concentration causing zero cell viability was 50%, which is too high for industrial application. Thus, whole-cell immobilization using glutaraldehyde was performed, and 0.1% (v/v) glutaraldehyde was determined as the optimum concentration to maintain activity and increase the half-life. It was also found that 0.1% (v/v) glutaraldehyde reacted with 41.9% of the total amine residues on the surface of the cells during the treatment. As a result, the half-life of the permeabilized cells was increased from 90 to 210 days by glutaraldehyde treatment after permeabilization, and no cell viability was detected.

• Environmental Analysis Health and Toxicology
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• 제12권3_4호
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• pp.55-59
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• 1997

Furfural, an organic solvent, is widely used as synthetic component material in producing chemical products. However, furfural has been reported that it shows strong toxicities to human being showing intense stimulus to skin, eyes, mucous membrane and nerve system. It is also known to cause anemia, liver cirrhosis, kidney failure and genetic toxicity in the human being working in the exposed area. LD$_{50}$ of furfural for peritoneal injected mouse has been known around 20mg/kg, but the acute toxicity on aquatic organisms such as fish, daphnid or algae are not well known, compared to those on rodents. In this experiment, we studied on the fish toxicity of furfural using Japanese Medaka (Orvzias latipes) and Common Carp (Cvprinus carpio). We also observed histological changes in the fish organs. The LC$_{50}$ were 12. Smg/L in Japanese Medaka and 21.8 mg/L in Common Carp, respectively. When Common Carps were exposed to 120mg/L of furfural concentration for 30 minutes, blood congestion in gills and lysis of secondary lamella were shown. Though the muscle of caudal fin was not completely eroded, its epidermic cells were shown to be necrotic in various parts. Tissue atrophy and cell necrosis were also shown in the liver of Common Carps exposed to furfural. From these results, furfural seems to cause histological damages on liver, an internal organ as well as on external organs such as gills and fins eventhough the fish were exposed for a short-term.

• ETRI Journal
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• 제35권4호
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• pp.571-577
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• 2013

The fabrication of a thin-film transistor backplane and a liquid-crystal display using printing processes can eliminate the need for photolithography and offers the potential to reduce the manufacturing costs. In this study, we prepare contact via structures through a poly(methyl methacrylate) polymer insulator layer using inkjet printing. When droplets of silver ink composed of a polymer solvent are placed onto the polymer insulator and annealed at high temperatures, the silver ink penetrates the interior of the polymer and generates conducting paths between the top and bottom metal lines through the partial dissolution and swelling of the polymer. The electrical property of various contact via-hole interconnections is investigated using a semiconductor characterization system.

• 대한안전경영과학회지
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• 제16권2호
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• pp.81-90
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• 2014

Flexible production system has been expanded to all sectors of economy with the change of labor market and diversification of employment. The unstable employment with irregular work has replaced stable employment with regular work. This study has investigate the impact pathway of the type of employment on health status especially ill-health symptoms experiences. Among the first Korean Working Conditions Survey data, the employee's response data was used to analyze the path way with multiple regression analysis. The result has shown the direct effect of the type of employment on ill-health symptoms experience. Indirect effect of the type of employment was found the pathway via the exposure to noise, high temperature, low temperature, dust, skin contact to chemicals, painful posture, heavy material handling, standing position, repetitive movement of hands. However the exposure to the other hazardous factors such as organic solvent, wholebody vibration, radiation, lifting people, infectious materials were not influenced by the type of employment.

• Applied Biological Chemistry
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• 제37권5호
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• pp.402-408
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• 1994

생리활성물질 monocerin의 구조상관활성을 조사하기 위해서 (8S, 9S, 11R)-(-)-monocerin과 (9S, 11R)-(+)-Fusarentin 4, 5-dimethyl ether를 합성하였는데, 합성은 benzylic anion과 유기용매에서 빵효모를 이용한 생체촉매반응으로 얻어진 (R)-aldehyde와의 축합에 의해 완성되었다. 합성되어진 화합물들은 병와 양상치를 대상으로 생리활성을 조사하였다. 특히, 벼의 생리활성검사에서 monocerin은 제2전엽보다 뿌리의 신장을 더 저해하였는데, fusarentin 4, 5-dimethyl ether는 제2전엽의 신장을 더 저해하였다. 생리활성시험의 결과, monocerin의 C환은 생리활성에 영향을 미치지 않는다는 사실이 예견되었고, 천연물의 입체구조적 배치가 비천연물의 입체구조적 배치보다 더 높은 생물활성을 나타내고 있다는 사실을 알 수 있었다.

• KSBB Journal
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• 제8권3호
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• pp.230-236
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• 1993

Chitin과 cellulose를 dimethylacetamide/LiCl 용매에 용해시켜 유리판 위에서 Chitulose film을 제조 하였다. 이 film은 토양속에서 20일 후에 거의 분해 되었고, 토양 미생물을 16-26hr 후에 투과시켰다. 한편, 필름의 투과도를 검토해 본 결과 물의 투과도는 Chitulose film에서 chitin, cellulose의 혼합 비율에 따라 0~187,500ml/$m^2$/day로 cellulose 함량이 높을 수록 투과도가 낮게 나타났으며, 풍건보다는 중탕에 의한 필름건조방법으로 제조된 것이 우수하였다. 각종 유기물의 최대, 최소투과도는 Chitulose film 의 종류에 따라 달리 나타나 chitin과 cellulose의 조성에 따라 선택적 투과성을 나타내였다. $Na^+$ 이온에 대한 투과도도 달리 나타나 보였고, 산소 투과도도 역시 Chitulose film의 조성에 따라 14-17,850 c $cm^3/m_2$/day로 큰 차이를 보였다. 2~3도 화상을 입힌 쥐에다 Chitulose film을 인조피부로 사용한 결과 염증없이 14일 후에 딱지가 떨어졌고, 31일 후에 완치되는 것이 관찰되었다.

• 대한안전경영과학회지
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• 제14권4호
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• pp.59-70
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• 2012

This study compared data regarding industrial accidents and awareness level for beauty product safety for four main parts of beauty industry such as hair-care, nail-care, skin-care, and make-up. Major risk factors in beauty industry are dust, musculoskeletal disorders, and organic solvent of beauty product in order of percentage. The specific types of industrial accidents in beauty industry are mainly associated with musculoskeletal system such as cuts, sprain, and varicose vein. They are mainly compensated by personal budget. The awareness levels of chemical and heavy metal containment for beauty product by beauty industry employee were 77.2% and 59.1% respectively. Most employee confirmed only important items of labelling requirement of beauty product. Also, most employee did not understand MSDS(Materila Safety Data) for chemicals used in beauty industry. Only 38.1% of beauty industry employee has had safety education while most employee (73.6%) realized that they needed safety education. Also, safety education supervised by KOSHA(Korea Occupational Safety and Health Agency) was the most preferred. This study would be good basis for safe and healthy working environment of beauty industry employee.

• Nuclear Engineering and Technology
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• 제54권5호
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• pp.1623-1634
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• 2022

A new irradiation loop design has been developed, which provides the ability to carry out radiolytic resistance studies of extraction systems simulating process relevant conditions in an easy and simple way. The step-by-step loop configuration permits an easy modification of settings and has a relative low volume requirement. This irradiation loop has been initially set up to test the main EURO-GANEX process steps: the lanthanide (Ln) and actinide (An) co-extraction followed by the transuranic (TRU) stripping. The performance and changes in the composition have been analyzed during the irradiation experiment by different techniques: gamma spectroscopy and ICP-MS for the extraction and corrosion behavior of the full system, and HPLC-MS and Raman spectroscopy to determine the degradation of the organic and aqueous solvents, respectively. The Ln and An co-extraction step and the corrosion that occurred during the first irradiation step revealed the favorable expected results according to literature. The effects of acidity changes occurred during the irradiation process, the presence of stainless corrosion products in solution as well as the new possible degradation compounds have been explored in the An stripping step. The results obtained demonstrate the importance of developing realistic irradiation experiments where different factors affecting the performance can be easily studied and isolated.

• 자원리싸이클링
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• 제27권3호
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• pp.8-15
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• 2018

Nd-Fe-B 폐 영구자석으로부터 회수한 염화희토류용액을 PC88A에 의한 경희토류(Pr, Nd)/중희토류(Tb, Dy) 분리정제에 대한 용매추출 연구를 진행하였다. 회분식 실험 단계에서 추출제(PC88A) 농도 0.5 M, 추출 후 평형 pH는 0.8~1.0(feed의 초기 pH 1.3), 세정액(HCl)의 농도는 0.1 M, 탈거액(HCl)의 농도는 2 M 이상일 때 분리 효율이 좋은 것을 확인하였다. 이 결과값을 혼합침강조에 적용하여 초기 조건에서 운용 조건을 변화시키면서 180시간 운용하여 3N급의 경희토류(Pr, Nd)/중희토류(Tb, Dy)금속 이온으로 분리정제 후 회수하였다.