• Magazine of the Korean Society of Agricultural Engineers
• /
• v.31 no.3
• /
• pp.57-69
• /
• 1989

The study was carried out for the strength parameter of coarse grained Soil and slope stability analysis of earth dam. The test samples were taken fifteen kinds of soil from cohesive soil to coarse gravel. The degree of compaction of test samples for shear test and permeability test was chosen 95 percentage of maximum dry density. The results of this study are as follows ; 1.The maximum dry density(Yd) of coarse grained soil increase in proportion to coarse particles(P) with the relation of Y d= 1.609+0.0043P. 2.The coefficients of permeability(k) decrease by the increase of fine particles(n) with the relation of k=0.0426e-0 185n. 3.The cohesions of soil decrease by the increase of coarse particles, but internal friction angles are more increased in same condition. 4.The internal friction angles(${\Phi}$) decrease in inverse proportion to void ratio(e) with the relation of ${\Phi}$ = 73.068 - 69.268e. 5.The strength parameters( Ct ${\Phi}$t) by triaxial compression test are clearly smaller than that (Cd, ${\Phi}$d) by direct shear test in fine grained soil, but the differences between both parameters are a little in coarse grained soil.The relations of both parameters are as follows; Ct = O.544Cd + 0.04 ${\Phi}$t= 1.282${\Phi}$d-2306 6.In cohesive soil, the strength parameters( Cl ${\Phi}$l) by large size shear test apparatus are similar to the strength parameters(Cs , ${\Phi}$s) by small size shear test appratus, but Cs and ${\Phi}$s values are larger than Cl and ${\Phi}$l values from 10 percentage to 20 percentage in coarse grained soil. 7.The fine grained soil is inappropriate to high dam more than 20 meters and it must be taken coarse grained soil with high internal friction angle for high dam.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.55 no.3
• /
• pp.294-301
• /
• 2022

Laver Pyropia tenera snack is typically manufactured as an attached laver and carbohydrate-based rice papers or glutinous rice paste. Carbohydrates contribute to a crispy texture and many various additives are used for development of texture. Isomalto-oligosaccharide (IMO) and corn starch (CS) are typical additives in snack products that produce several changes, including texture. We investigated physicochemical properties of laver snacks prepared using IMO/CS ratios of 1:0 (Sample 1), 3:1 (Sample 2), 1:1 (Sample 3), 1:3 (Sample 4), and 0:1 (Sample 5). All of the prepared laver snacks displayed constant drying rates up to 45 minutes. Samples 1 and 5 had higher drying rates than the other laver snacks. Concerning CIE color values, Sample 5 displayed the highest brightness (L^*) value (78.89) and lowest yellowness (b^*) value (6.66). In contrast, Sample 1 displayed the lowest L^* value (74.65) and highest b^* value (17.23). The hardness proportionally decreased along with IMO content. In the sensory evaluation, overall acceptance was highest for Sample 1 with the highest oligosaccharide content.

• Journal of Korean Society of Environmental Engineers
• /
• v.28 no.2
• /
• pp.158-164
• /
• 2006

Offensive odor from CAFO(concentrated animal feeding operation) and its control have become a significant issue in Korea. Control of odors from the CAFO requires to identify major odorant and their generation mechanisms. In this study, an easy method to collect gas sample and to quantify its odorants is proposed. The method involves on-site odorant extraction with solid-phase microextraction and quantitation with GC/MSD or GC/FID. Analytes of the current study include: trimethylamine(TMA), carbon disulfide($CS_2$), dimethyl sulfide(DMS), dimethyl disulfide(DMDS), acetic acid(AA), propionic acid(PA) and n-butyric acid(BA). The resulting linearity($R^2$) of calibration curve for each analyte was good over the range from several ppbv to ppmv; 0.984 for TMA(0.056-1.437), 0.996 for $CS_2$(0.039-0.999), 0.994 for DMS(0.029-0.756), 0.995 for DMDS(0.024-0.623), 0.992 for AA(0.068-1.314), 0.955 for PA(0.047-0.940), and 0.976 for BA(0.036-0.712). Method detection limits were 5.67, 6.39, 5.78, 25.2, 0.098, 0.363 and 0.099 ppbv for AA, PA, BA, TMA, DMS, $CS_2$, and DMDS, respectively. With the developed method, odorants from poultry, swine, and cattle barns were analysed. All the compounds but DMDS were detected from the sample collected in the poultry barn, and their levels exceeded the representative published human olfactory threshold.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.33 no.4
• /
• pp.646-652
• /
• 2004

With the aim of using a cosmetic material, chondroitin sulfates extracted from midduck tunics (Styela clava) and munggae tunics (Halocynthia roretzi) were examined in vitro with two cell lines for cell toxicity, collagen synthesis, cell growth and recovery ability after U.V. irradiation. Cell toxicity test with A 431 and CCD 1108Sk was able to observe high activity between 400 and 600 $\mu\textrm{g}$/m while standard chondroitin sulfate (CS) purchased from Sigma was showed at 80 $\mu\textrm{g}$/mL. Even fraction 1 and 2 collected from chondroitin sulfates originated from midduck appeared having the highest activity between 600 and 1000 $\mu\textrm{g}$/mL, but slightly lower compared to crude chondroitin sulfates from both mideduck and munggae. In cell growth examination, it was not able to find significant differences between chondroitin sulfates used. Both crude chondroitin sulfates were exhibited the highest activity for two cell lines except that of mideduck which was showed activity for CCD 1108Sk. CS, fraction 1 and 2 from midduck were not able to demonstrate a significant activity in collagen synthesis. On the contrary, crude chondroitin sulfates from both munggae and midduck were showed the highest activity at 100 and 50 $\mu\textrm{g}$/mL with only CCD 1108Sk. The recovery ability after U.V. irradiation with crude chondroitin sulfates from both munggae and midduck were showed high activity at 400 $\mu\textrm{g}$/mL with CCD 1108Sk and A 431. But there were no activity observed in fractions examined, As a consequence, the crude chondroitin sulfates from both munggae and midduck might not only be available as a cosmetic material but also useful for increasing some activity by blending properly.

• Korean Journal of Microbiology
• /
• v.39 no.2
• /
• pp.118-122
• /
• 2003

To develop vector plasmid for the bacteriophage P2-P4 system which is a useful experimental tool for the study of viral capsid assembly, we constructed a new P4-derived vector plasmid starting from P4 ash8 sid71 With recombinant DNA technology, a portion of P4 genome was deleted and tetracyclin resistance gene (terR) was introduced into P4 genome to give P4 selectivity. Resulting P4 ash8(sid71) terR was 12.09 kb long and could be converted to a viable bacteriophage with P2 infection. The burst size of induced bacteriophage form of P4 ash8(sid71) terR was determined. The CsCl buoyant equilibrium density gradient experiment of new P4 derivative suggested the upper limit of packaging capacity in P2-size head.

• Membrane Journal
• /
• v.16 no.1
• /
• pp.59-67
• /
• 2006

Biodegradable amphiphilic polymer was synthesized for removing hydrophobic pollutants(phenol, 4-nitrophenol, benzene, and toluene) and metal ions ($Cs^{+},\;Mg^{2+},\;Cu^{2+},\;Ni^{2+}$, and $Cr^{3}$). The methoxy poly(ethylene glycol)s with different molecular weights (1,100 and 5,000) were used as a hydrophilic segment. The rejection ratio improved in the relatively high molecular weight of MPEG. The rejection ratio of biodegradable nanoparticles without pollutants was over 98%. In removal of hydrophobic pollutants, the rejection ratio increased with the hydrophobic properties. The electron valence affects the rejection ratio of metal ions, indicating rejection ratio was ordered as $3^{+}>2^{+}>1^{+}$.

• Journal of Pharmaceutical Investigation
• /
• v.31 no.3
• /
• pp.185-190
• /
• 2001

Human papillomavirus (HPV) infection is known to cause cervical cancers. Human papillomavirus-like particles (VLP) have been studied as preventive vaccines of cervical cancers. To develop VLP as a therapeutic gene carrier, we studied the method to encapsulate cytokine genes in virus-like particles. HPV type 16 capsid L1 genes were amplified by polymerase chain reaction and cloned into T vector. L1 gene was then inserted into baculovirus transfer vector. The clone of baculovirus encoding L1 gene was isolated and used to express L1 protein in Sf 21 insect cells. VLP were purified by CsCl density gradient and ultracentrifugation. VLP were disassembled to capsomer units by treatment of a reducing agent. Given that interleukin-2 (IL-2) genes have been used in anticancer gene therapy and as a molecular adjuvant, IL-2 cytokine plasmids were chosen as a model gene. IL-2 plasmids were incubated with the disassembled capsomer suspension. To reassemble the particles, the mixture of capsomers and cytokine plasmids was dialyzed. The disassembly and reassembly of VLP were confirmed by transmission electron microscopy. The entrapment of cytokine plasmids in reassembled VLP was tested by the stability of plasmids against DNase I. After treatment of reassembled virus-like particles with DNase I, discrete IL-2 DNA band was observed. Our results indicate that IL-2 cytokine plasmid (3.5 kb size) can be encapsulated in the virus-like particles, suggesting the potential of VLP as a gene delivery system. Moreover, VLP containing the adjuvant cytokine plasmids might function as more effective subunit vaccines.

• Journal of Convergence for Information Technology
• /
• v.12 no.1
• /
• pp.135-143
• /
• 2022

In this study, the antioxidant and anti-inflammatory properties of Colpomenia sinuosa extracts were identified. Antioxidant experiments included DPPH, ABTS, nitrite scavenging experiments, and FRAP, polyphenol concentration measurements, flavonoid concentration measurements. DPPH assay results showed an antioxidant function of 2.821 mg ascorbic acid/g extract. ABTS assay results showed an antioxidant function of 3.923 mg ascorbic acid/g extract. nitrite assay results showed an antioxidant function of 17.89 mg ascorbic acid/g extract. In FRAP, 1 mg of the Colpomenia sinuosa extract showed a reduction of 2.062±0.177 ㎍ of ascorbic acid. For polyphenols, 62.85±3.18 mg/g was shown. Flavonoids showed 10.01±0.24 mg/g. In the meantime, cell experiments showed cytotoxicity and anti-inflammatory functions. In cytotoxicity experiments, Colpomenia sinuosa extracts showed cytotoxicity of less than 20% and an inflammatory inhibition of 30.93±2.93% at a concentration of 100 ㎍/mL. These results indicate that Colpomenia sinuosa extract is available as functional cosmetic material.

• Clean Technology
• /
• v.25 no.1
• /
• pp.91-97
• /
• 2019

Oxidative desulfurization (ODS) has received much attention in recent years because refractory sulfur compounds such as dibenzothiophenes can be oxidized selectively to their corresponding sulfoxides and sulfones, and these products can be removed by extraction and adsorption. In this work, The oxidative desulfurization of marine diesel fuel was performed in a batch reactor with hydrogen peroxide ($H_2O_2$) in the presence of various supported heteropoly acid catalysts. The catalysts were characterized by XRD, XRF, XPS and nitrogen adsorption isotherm techniques. Based on the sulfur removal efficiency of promising silica supported heteropoly acid catalysts, the ranking of catalytic activity was: $30\;H_3PW_{12}/SiO_2$ > $30\;H_3PMo_{12}/SiO_2$ > $30\;H_4SiW_{12}/SiO_2$, which appears to be related with their intrinsic acid strength. The $30\;H_3PW_{12}/SiO_2$ catalyst showed the highest initial sulfur removal efficiency of about 66% under reaction conditions of $30^{\circ}C$, $0.025g\;mL^{-1}$ (cat./oil), 1 h reaction time. However, through the recycle test of the $H_3PW_{12}/SiO_2$ catalyst, significant deactivation was observed, which was attributed to the elution of the active component $H_3PW_{12}$. By introducing cesium cation ($Cs^+$) into the $H_3PW_{12}/SiO_2$ catalyst, the stability of the catalyst was improved with changing the solubility, and the $Cs^+$ ion exchanged catalyst could be recycled for at least five times without severe elution.

• Journal of Korea Port Economic Association
• /
• v.29 no.2
• /
• pp.255-275
• /
• 2013

The purpose of the study is to examine compliance criteria for documents of the Letter of Credit(L/C) by the Korean Supreme Court in practical use. The judgement criteria of the court in documents' examination is supported by the doctrine of strict compliance. And, in examination of documents by the Supreme Court, the difference between documents presented and the credit should be followed by the allowance of international standard banking practices. In this case, the Supreme Court makes a reference for ICC's opinion or decision proposed as the international standard banking practices, or otherwise admit by exploring the practices. However, when documents reviewing by the bankers' auditors, it is very difficult for them to judge in a short time due to the lack of high level of knowledges and insights. As shown the cases of this study, the doctrine of strict compliance of an L/C be relaxed, and most of the recent precedents be ruled by the exception of the doctrine. Because, therefore, it is difficult for to documents reviewers of bank to judge these consistencies, conducting arbitrary document review will be inevitable. As a result, it will be difficult for banks and applicants to ensure the strictness of the documents, and free use of L/Cs in international transactions will be avoided. Finally, the expanded usage of the electronic negotiation system that simplifies the highly difficult compliance criteria to ensure the strictness of documents will be needed, and not only be eradicated the acts of arbitrary documents examination practices, but also be promoted the freely usage of L/Cs.