• Korean Journal of Environmental Agriculture
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• v.24 no.3
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• pp.203-209
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• 2005

Objective of this research was to assess the effectiveness of the different sources of the zero-valent irons (ZVIs) on the reduction of the toxic Cr(VI) to the nonhazardous Cr(III) in an aqueous solution. The physical and chemical properties of the six ZVIs were determined. Particle size and specific surface area of the ZVIs were in the ranges of $85.55{\sim}196.46{\mu}m\;and\;0.055{\sim}0.091m^2/g$, respectively. Most of the ZVIs contained Fe greater than 98% except for J (93%) and PU (88%). Reduction efficiencies of the ZVI for Cr(VI) reduction were varied with kinds of ZVIs. The J and PU ZVIs reduced 100% and 98% of Cr(VI) in the aqueous solution, respectively, within 3 hrs of reaction. However, PA, F, Sand J1 reduced 74, 65, 29 and 11% of Cr(VI), respectively, after 48 hrs. The pH of the reacting solution was rapidly increased from 3 to $4.34{\sim}9.04$ within 3 hrs. The oxidation-reduction potential (Eh) of the reacting solution was dropped from 600 to 319 mV within 3 hrs following addition of ZVIs to the Cr(VI) contaminated water. The capability of ZVIs for Cr(VI) reduction was the orders of PU > J > PA > F > S > J1, which coincided with the capacities to increase the pH and decrease the redox potentials. Results suggested that the reduction of Cr(VI) to Cr(III) was derived from the oxidation of the ZVI in the aqueous solution.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.2
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• pp.136-141
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• 2009

Biological activities of enzymatic hydrolysate of spirulina (EHS) were investigated. EHS showed no significant effects on the growth-stimulating activity for lactic-acid bacteria and antioxidant activity. EHS showed slight in vitro growth-inhibitory effects (15% at 1.42 mg/L) on a human cervical cancer cell line (HeLa). In addition, the anticoagulant activities of EHS were measured based on three different pathways: common, intrinsic and extrinsic pathways. As an indication of anticoagulant activity on common pathway, thrombin time (TT) of EHS (100 mg/L) was measured as 155.6 sec. Activated partial thromboplastin time (aPTT) for intrinsic pathway of EHS (1,000 mg/L) was measured as 95.8 sec. Prothrombin time (PT) based on extrinsic pathway of EHS (1,000 mg/L) was measured as 10.6 sec. These data showed that EHS have influences on anticoagulant factors of common pathway and intrinsic pathway. Consequently it was found that EHS could be used as a functional food for blood circulation.

• Korean journal of applied entomology
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• v.15 no.4 s.29
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• pp.205-214
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• 1976

Effect of Butachlor(2-chloro-2, 6-diethyl N-(buthoxymethyl) acetanilide), Nitrofen(2,4-dichloro-4-nitrodiphenyl ether), Benthiocarb+Simetryne(s-(4-chlorobenzyl)-N, N-diethylthiocarbamate $7\%$+2-methylthio-4, 6-bis(ethylamino)-s-triazine $1.5\%)$, Propanil (3,4-dichloropropionanilide), and Perfluidone {1. 1. 1-trifluoro-N, N-(2-methyl-4-(phenylsulfonyl) Pheny1) methanesulfon amide} on urea hydrolysis and subsequent nitrification was investigated in a flooded soil incubated at $24\pm1^{\circ}C$ for 9 weeks. 1. Butachlor and Perfluidone at the rate of 1,440 and 1,200g, ai/10a, respectively, slightly inhibited the early stage of urea decomposition, and caused a slight decrease in the production of ammomium, which, however, was recovered readily. 2. Propanil at the rate of 2,800g, ai/10a imhibited the first stage of nitrification, and brought about a slight increase in the ammonium conentration and a decrease in the concentration of nitrite and nitrate. This inhibitive effect was a little more evident at higher concentration of applied nitrogen. The other herbicides caused no inhibition of urea decomposition and subsequent nitrification even at the highest rate of application. 3. pH and Eh of the soil were not significantly affected by the herbicides tested.

• Nuclear Engineering and Technology
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• v.29 no.2
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• pp.127-137
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• 1997

Equilibrium concentrations of major elements in an underground repository with a capacity of 100,000 drums have been simulated using the geochemical computer code (EQMOD). The simulation has been carried out at the conditions of pH 12 to 13.5, and Eh 520 and -520 mV. Solubilities of magnesium and calcium decrease with the increase of pH. The solubility of iron increases with pH at Eh -520 mV of reducing environment while it almost entirely exists as the precipitate of Fe(OH)$_3$(s) at Eh 520 mV of oxidizing environment. All of cobalt and nickel are predicted to be dissolved in the liquid phase regardless of pH since the solubility limit is greater than the total concentration. In the case of cesium and strontium, all forms of both ions are present in the liquid phase because they have negligible sorption capacity on cement and large solubility under disposal atmosphere. And thus the total concentration determines the equilibrium concentration. Adsorbed amount of iodide and carbonate are dependent on adsorption capacity and adsorption equilibrium constant. Especially, the calcite turns out to be a solubility-limiting phase on the carbonate system. In order to validate the model, the equilibrium concentrations measured for a number of systems which consist of iron, cement, synthetic groundwater and radionuclides are compared with those predicted by the model. The concentrations between the model and the experiment of nonadsorptive elements cesium, strontium, cobalt nickel and iron, are well agreed. It indicates that the assumptions and the thermodynamic data in this work are valid. Using the adsorption equilibrium constant as a free parameter, the experimental data of iodide and carbonate have been fitted to the model. The model is in a good agreement with the experimental data of the iodide system.

• Journal of Ocean Engineering and Technology
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• v.30 no.4
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• pp.268-276
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• 2016

This paper presents a study on the crashworthiness of the scaled-down stiffened panels used on a Korean icebreaker. In order to validate the crashworthiness of the panels, this paper provides various mechanical properties such as the results of a CVN test, quasi-static tensile test, and high-speed tensile test at arctic temperatures. Two types of steels (EH32 and FH32) were chosen for the material tests. CVN tests revealed that the two steels were equivalent up to −60℃ in terms of their impact energy absorption capacity. However, the toughness of FH32 was significantly superior to that of EH32. EH32 showed slightly higher flow stresses at all temperature levels compared to FH32. The improvement ratios of the yield strengths, tensile strengths, plastic hardening exponents, etc. for FH32, which were obtained from quasi-static tensile tests, showed an apparent ascending tendency with a decrease in temperature. Dynamic tensile test results were obtained for the two temperatures levels of 20℃ and −60℃ with two plastic strain rate levels of 1 s⁻¹ and 100 s⁻¹. A closed form empirical formula proposed by Choung et al. (2011;2013) was shown to be effective at predicting the flow stress increase due to a strain rate increase.

• Journal of the Korea Organic Resources Recycling Association
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• v.18 no.4
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• pp.69-76
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• 2010

After feeding mixed samples, VS ranged from 60 to 80% of total costs in 15 days. EC ranged from1.21 to 2.45, 1.25 to 2.1 and 1.2 to 1.88mS/cm when worms were fed with a mixture of by-products of tidal current and sewage sludge, a mixture of by-products of algae producy, and food wastes and a mixture of by-products of algae producy, sewage sludge and food wastes. That means the kinds of mixture don't have any negative impacts on worms survival. With the feed with a mixture of by-products of algae producy and food wastes and a mixture of by-products of algae producy, sewage sludge and food wastes, pH shows stable 5.4 to 6.7, and 6.2 to 7.4 where is suitable for worms. But a mixture of by-products of algae producy and sewage sludge is out of proper scope for raising worms, in other words, extra care will be necessary. In case of Eh, a mixture of by-products of algae producy and sewage sludge make eh negative (-) in early stage so also when feeding worms, also extra care will be needed. NaCl ranged from 0.32 to 0.82% or form 0.23 to 0.61% when a mixture of by-products of algae producy and food wastes and a mixture of by-products of algae producy, sewage sludge and food wastes were fed. So taking care of salts will be essential whenever feeding.

• Bulletin of the Korean Chemical Society
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• v.35 no.12
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• pp.3447-3452
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• 2014

Detailed chemical investigation of Boscia senegalensis (Per) Lam. ex Poir. led to the isolation of one new flavonol glycoside, rhamnocitrin-3-O-${\beta}$-$\small{D}$-(6"-O-E-feruloyl)-glucopyranoside named bosenegaloside A (1), with seven known compounds, rhamnocitrin-3-O-${\beta}$-$\small{D}$-(6"-O-E-p-coumaroyl)-glucopyranoside (2), rhamnocitrin-3-O-${\beta}$-$\small{D}$-glucopyranoside (3), 3,4,5-trimethoxyphenol-${\beta}$-$\small{D}$-glucopyrinoside (4), lasianthionoside A (5), 3,7-dimethyl-1-octene-3,6,7-triol-6-O-${\beta}$-$\small{D}$-glucopyranoside (6), syringin (7), and austroside B (8). The chemical structures of these compounds were elucidated from spectroscopic data and by comparison of these data with previously published results. The inhibitory activity of the isolated compounds on soluble epoxide hydrolase (sEH) was assessed. Compounds 1-3 potently inhibited sEH activity with $IC_{50}$ values of $12.8{\pm}0.5$, $18.4{\pm}0.2$, and $11.3{\pm}0.9{\mu}M$, respectively.

• Archives of Pharmacal Research
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• v.17 no.5
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• pp.381-382
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• 1994

Administration route dependency on the distribution of PEGylated recombinant human turor necrosis factor binding protein (rhTNFbp-PEG20K dimer) was observed following a subcutaneous (sc) and an intravenous (iv) administrationin rats. ehTNFbp-PEG20K dimer is composed of two rhTNGbp molecules (molecular weight 18, 278 daltons each) joined by polyethylene glycol 2000(PEG30K). The steady state distribution volume of rhTNFbp-PEG20K was 55 m/kg and 359 ml/kg following the i.v. and s.c. administrations, respectively. These results suggest that the distribution of ehTNFbp-PEG20K is limited within the cpillary space after i.v. administration, while rhTNFbp-PEG20K can distribute into a space (35.9% of body weight) which is between extracellylar space and total body water. A lymphatic absorption may paly a role in the distribution of rhTNFbp-PEF20K dimer following the sc administration. The present study suggests that the administration route of a lartge protein molecule should be determined depedning upon target sites.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.5
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• pp.9-16
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• 2019

Recent economic trends are worsening and becoming longer, and Korean shipbuilding is focused on high value added and high technology, especially for LNG carriers and large container ships. Both ship types increased in size in the 2010s but have requirements such as high strength, toughness at low temperatures and continuous weldability for preventing brittle fractures at service temperatures. In particular, as container ships become larger, the International Classification Society (IACS) has established a provision (IACS UR S33) that mandates the use of BCA (Brittle Crack Arrest) certified vessels for large container vessels contracted after 2014 to ensure safety. Therefore, studies on BCA 47Y.P are currently being undertaken, but BCA 40Y.P has not been actively studied yet. We will test BCA 40Y.P to verify why it can be applied to a large container ship and measure fatigue cracking.

• Korean Journal of Soil Science and Fertilizer
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• v.1 no.1
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• pp.7-11
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• 1968

A high and low productive paddy soils were waterlogged at $30{\pm}2^{\circ}C$ for 35 days in the laboratory. The relation of pH and Eh changes, ferrous iron and ammonium nitrogen of these soils was studied. The results obtained are summarized as follows: 1. pH value has been increased for 13 days of incubation and after 13 th day, they maintain their pH value without marked change, and pH value of high productive soil is higher than that of low productive soil by 0.25-0.30. 2. Eh value has been decreased for 10 days of incubation and then they also maintain their Eh value without marked change. Eh value of high productive soil is lower than that of low productive soil by 50-70 mv. 3. In both soils ferrous iron formed under submerged condition increased steeply within 4-5 days of incubation and after that they maintain their content without marked change. The $Fe^{+{+}}$ content of high productive soil is higher than low productive soil by 1.0 mg/1 gr soil. 4. $NH_4{^{-N}}$ formed under submerged condition rapidly increased in the early period of incubation and after that decreased to a certain level and maintain their content, but its content of high productive soil is higher than that of low productive soil by $20-25{\gamma}/1\;gr$ at the early stage and lower at the latter period by $10-15{\gamma}/1\;gr$.