• Resources Recycling
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• v.25 no.3
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• pp.29-36
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• 2016

The characteristics analysis and pH neutralization test were carried out to use of slurry generated from recycling processes of construction wastes. D (5.0) of raw sludge was $42.4{\mu}m$ and over 60 % of sludge distribute under 45 um (-325 mesh). Muscovite and carbonate minerals were main minerals of fine particles, and the portion of carbonate minerals increased as particle size decreased. Although the more heavy metals were observed in the finer particle size, the contents was found to be less than Korean contaminated soil regulation (area 2). The effects of flocculants addition for accelerating solid-liquid separation were negligible because the slurry already contains excess of coagulant added in the waste concrete recycling process. It was difficult to neutralize the sludge supernatant due to high pH (about 12) by adding acids, but the introduction of $CO_2$ decreased the pH to 8.5, The precipitate recovered during $CO_2$ introduction was determined to be $CaCO_3$ with XRD, and it indicates that high pure $CaCO_3$ could be obtained during the process.

• Nuclear Engineering and Technology
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• v.27 no.4
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• pp.544-554
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• 1995

Pool boiling of dilute aqueous solutions of polyethylene oxide polymer has been experimentally investigated for the purpose of understanding the physical mechanisms of the suppression of vapor explosions in this polymer solution. Tn solid spheres of 22.2mm and 9.5mm-diameter ore heat-ed and quenched in the polymer solutions of various concentrations at 3$0^{\circ}C$. The results showed that minimum film boiling temperature($\Delta$ $T_{MFB}$) in this highly-subcooled liquid rapidly decreased from over $700^{\circ}C$ for pure water to about 15$0^{\circ}C$ as the polymer concentration was increased up to 300ppm for 22.2mm sphere, and it decreased to 35$0^{\circ}C$ for 9.5mm sphere. This large decrease of minimum film boiling temperature in this aqueous polymer solution may explain its ability to suppress spontaneous vapor explosions. Also, tests with applying a pressure wave showed that the vapor film behaved more stable against an external disturbance at higher polymer concentrations. These observations together with the experimental evidences of vapor explosion suppression in dilute polymer solutions suggest that the application of polymeric additives such as polyethylene oxide as low as 300ppm to reactor emergency coolant be considered to prevent or mitigate energetic fuel-coolant interactions during severe reactor accidents.s.

• Natural Product Sciences
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• v.22 no.1
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• pp.46-52
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• 2016

Erectile dysfunction (ED) is a highly prevalent disorder that affects millions of men and considered to be an early symptom of atherosclerosis and a precursor of various systemic vascular disorders. The aim of the present study was to prepare ginsenoside Re enriched fraction (GS-F3K1, ginsenoside Re 10%, w/w) from ginseng berries flesh and to investigate the enhanced activities of GS-F3K1 on alcohol-induced ED. GS-F3K1 was prepared by the continuous liquid and solid separating centrifugation and circulatory ultrafiltration from ginseng berries flesh. GS-F3K1 was administered for 5 weeks in ethanol-induced ED rat by oral administration of 20% ethanol. To investigate the effects of GS-F3K1 on ED model, the levels of nitrite expression, cyclic guanosine monophosphate (cGMP) and erectile response of the penile corpus cavernosum of rat were measured. The erectile response of the corpus cavernosum was restored after GS-F3K1 administration, to a level similar to the normal group. The level of nitrite and cGMP expression in the corpus cavernosum of GS-F3K1-administered male rats was increased significantly compared to positive control group. GS-F3K1 from ginseng berries should effectively restore ethanol-induced ED in male rats and could be developed as a new functional food for the elderly men.

• Korean Journal of Plant Tissue Culture
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• v.24 no.3
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• pp.183-188
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• 1997

Callus from scale segments of Lilium longiflorum 'Gelia' was effectively induced and maintained from unorganized tissue on the semi-solid medium by 0.42% Bacto agar with MS basal salts and vitamins of SH medium supplemented with 0.5 mg/L 2, 4-D, 1.0 mg/L NAA, 0.3 mg/L BA, and 3% sucrose. More than 5% of high sucrose level had inhibiting effect on regeneration capacity of formed callus and decreased callus growth. Various combinations of nitrogen did not effective to proliferate the ELC (Embryogenic-like callus), but friability of callus was increased in the medium containing only nitrate as nitrogen source. 5 mL conditioned medium into 30 mL fresh medium was good for cell growth. However friable cell aggregates during suspension culture had to form hard callus which hindered to establish suspention culture system. Addition of 2 g/L casein hydrolysate increased callus growth and friability of the hard callus. As a result of anatomical observation of callus, organogenesis such as shoots, roots and bulblets was independently induced from callus tissue. Somatic embryogenesis from callus tissue could be observed with low frequency.

• Food Science of Animal Resources
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• v.29 no.6
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• pp.719-725
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• 2009

Heterocyclic aromatic amines (HCAs) are potent mutagens and possible human carcinogens that are formed during the heating of protein-rich foods. The effects of preheating treatment of beef patties using a microwave prior to frying at $220^{\circ}C$ for 10 min on each side on the reduction of HCAs (amino-carbolines and amino-imidazo-azaarenes) were evaluated. The amount of HCAs was then evaluated by solid-phase extraction and high pressure liquid chromatography (HPLC) analysis. The beef patties were treated by microwaving for various times (0, 1, 1.5, 2, or 3 min) before pan-frying. The results revealed the presence of 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2), 3-amino-1,4-dimethyl-5H-pyrido-[4,3-b] indole (Trp-P-1), 2-amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole (Glu-P-1), 2-aminodipyrido[1,2-a:3',2'-d]imidazole (Glu-P-2), 9H-pyrido[3,4-b]indole (Norharman), 1-methyl-9H-pyrido[3,4-b]indole (Harman), 2-amino-9H-pyrido[2,3-b] indole ($A{\alpha}C$), 2-amino-3,8 dimethylimidazo[4,5-f]-quinoxaline (MeIQx) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]-pyridine (PhIP) in all samples. However, microwave pretreatment for 1 min inhibited the formation of these HCAs by up to 90% when compared to the control.

• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1426-1432
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• 2000

The effects of raw anchovy, salted raw anchovy (20% salt+anchovy), 6- and 12-month fermented anchovy (20% salt added) on the N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced mutagenicities were evaluated using Salmonella assay and the SOS chromotest. The methanol extracts from raw, salted and the fermented anchovy (FA) sample increased the revertants of Salmonella typhimurium TA100 at the level of $0.125{\sim}5\;mg/plate$ in Ames test. The salted raw anchovy extract induced the largest number of the revertants. All the FA extracts had comutagenic effect on the MNNG. Twelve-month FA juice exerted the lowest comutagenic activity among the FA samples. The comutagenicity of 12-month FA was due to the synergistic effect of salt and histidine which teem in FA. Thus the Ames test using histidine requiring mutant, S. typhimurium, is not appropriate to determine the mutagenicity of FA which is rich in histidine. In SOS chromotest using E coli, raw, salted and fermented anchovy extracts did not show any mutagenicity in the absence of MNNG. The raw and fermented anchovy samples blocked the SOS response of E. coli PQ37 induced by MNNG, while raw salted anchovy increased the SOS induction factor. Twelve-month FA juice showed higher antimutagenic effects than 6-month FA samples (both solid and liquid). The ripened (12-month) FA along with raw anchovy in the SOS chromotest exhibited antimutagenic activity.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.660-668
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• 2017

In this study, we conducted an assessment of the risks posed by the noxious chemicals often handled at the analysis centers of organizations involved in Work Environment Measurement (WEM) using the Chemical Hazard Risk Management (CHARM) system. For this purpose, six organizations involved in WEM located in Seoul and Gyeonggi, which conducted the risk assessment, were selected and, as a result, 29 materials were selected as chemical substances presenting a risk of exposure. In terms of their physical properties, there were 16 liquid and 10 solid materials, and for the special management materials (CMR), the findings were as follows: 'Carcinogenic' 1A - 11 and 1B - 1 (2 - 8); 'Mutagenic' 1A - 4 and 1B - 3 (2 - 8); and 'Repro-toxic' 1A - 0 and 1B - 1 (2 - 6). In the risk estimation, 30.4%, 66.1% and 3.6% of the materials presented 'low', 'average' and 'high' risks, respectively. In addition, two of these six institutions had materials presenting a 'high' risk. This study is significant in that the risk assessment was conducted using CHARM, a chemical substance assessment tool. It is expected that the results will be utilized as the basic data for safety assessment, the establishment of a plan for emergency measures and drawing up a safety management manual, and the institutional and legal management of accidents and risks in the analysis centers of organizations involved in WEM and the management of chemicals by drawing attention to the risks involved.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.5
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• pp.649-653
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• 1999

A magnetic fluid separation technology was confirmed to be very effective to remove the suspended solids (SS) from aquacultural recirculating water, In this study, the effects of operating variables on the characteristics of SS removal were investigated through the test runs using magnetite of 2 $\mu$m mean diameter as magnetic powder. Magnetic flocculation here formed by adsorbing fine magnetites on the surface of suspended solid was observed. The strength of magnet was of significance in determining the SS removal efficiency as well as the capacity of the equipment. In addition, the SS removal efficiency decreased with an increase in the superficial liquid velocity, but the effect became negligible when the mass ratio of magnetite to the suspended solids was higher than 1.0.

• Polymer(Korea)
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• v.36 no.1
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• pp.71-75
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• 2012

In this study, silver nanoparticles (AgNPs) have been prepared by using aqueous $AgNO_3$ solution in the poly(vinyl alcohol) (PVA) hydrogels. PVA powders were dissolved in deionized water, and then irradiated by gamma-ray with a radiation dose of 50 kGy to make hydrogels. PVA hydrogels were dipped into 0.01 and 0.05 M $AgNO_3$ solution for 1 h respectively. After that, the swollen hydrogels were irradiated by gamma-ray at various doses to form AgNPs. UV-vis analysis indicated that the concentration of Ag NPs was enhanced by increasing absorbed dose and the concentration of $AgNO_3$. FE-SEM measurements provided further evidence for the successful formation of Ag NPs in PVA hydrogels. Also, the antibacterial effect of PVA hydrogels stabilized AgNPs against Gram-negative bacteria (S.aureus and E.coli) in liquid as well as on solid growth media has been investigated. The AgNPs consolidated in PVA hydrogel networks have an excellent antibacterial effect.

• FLOWER RESEARCH JOURNAL
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• v.18 no.3
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• pp.179-185
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• 2010

This study was carried out to investigate the optimal culture conditions for gametophytes growth and sporophytes regeneration of Pyrrosia linearifolia in order to provide for the masspropagation system foundation of Pyrrosia linearifolia using their life cycle. Among many different media, 2MS medium was most effective in prothallus proliferation. Prothallus growth was promoted as the total concentration of nitrogen sources increased, and the best result was observed on 120 mM nitrogen. The best concentration of sucrose was 3%. The addition of 5~20 mM IAA, NAA, BA and kinetin promoted the propagation of prothallus. But 2iP demonstrated the most inhibitory effect on prothallus proliferation. Gametophytes shaking-cultured with liquid medium showed similar growth with solid medium and normal formation of reproductive organs. Shoot regeneration was most effective on 1/8MS medium, but growth was promoted on 1/2MS medium. For promotion of shoot regeneration and growth, the suitable concentrations of sucrose and $NaH_2PO_4$ were 1% and $50{\sim}100mg{\cdot}mL^{-1}$ in 1/8MS medium, respectively.