• Journal of the Korean Geosynthetics Society
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• v.8 no.4
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• pp.27-34
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• 2009

In this paper, characteristics of shear strength and deformation of geosynthetics-reinforced slag materials are described. In order to investigate the effect of geosynthetics on shear strength and deformation behavior of slags, when they are reinforced with geosynthetics or geomat such as PET mat, large triaxial tests were performed under consolidated-drained condition. The materials used in the study are real ones as they are in the field, so that the scale effect of samples disappeared. From the large triaxial tests, it was observed that the stress-strain relationship of geosynthetics-reinforced slags shows relatively small dilatancy and weak tendency of strain hardening, compared with that of slags without reinforcement. The shear strength parameters such as apparent cohesion and internal friction angle increase with PET mat reinforcement, consequently result in about 1.2 (for low confining pressure) to 1.4 (for high confining pressure) times of shear strength of un-reinforced sample. Therefore, the adoption of geomat-reinforced slag layers leads to an increase in the factor of safety for embankment design on soft soil formations.

• Journal of the Korean Geotechnical Society
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• v.20 no.5
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• pp.59-66
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• 2004

This study compared the reinforcing effect of sand by Geocell to those of newly devised Tirecell$^{\circledR}$ made by waste tires, tire mat by sidewalls of tires. Plate loading tests in a large chamber were conducted for different reinforcing materials at the same conditions of relative density, embedded depth of sand. The combination of Tirecell and sidewall gives the highest increase of bearing capacity and reduction of settlement. The Geocell with the same height of Tirecell gives similar reinforcement effect to the tire mat made by sidewalls.

• Mycobiology
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• v.48 no.1
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• pp.75-79
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• 2020

Anthracnose is one of the major problems for cultivating many crops, including vegetables, fruits, and trees. It is a continual threat for fruits grower worldwide. Colletotrichum fructicola was isolated from Shine Muscat berries showing typical anthracnose symptom in Korea. It was identified as C. fructicola based on morphology, pathological signs and concatenated sequences of internal transcribed spacer region of rDNA, glyceraldehyde-3-phosphate dehydrogenase, β-tubulin-2, chitin synthase-1, calmodulin, and the Apn2-Mat1-2 intergenic spacer and partial mating type (Mat1-2) gene. To the best of our knowledge, this is the first report first report of anthracnose of Shine Muscat caused by C. fructicola in Korea.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.364-371
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• 2004

This study presented the reinforcing effect of sands by newly devised $Tirecell^{(R)}$ made by waste tires, tire mat by sidewalls of tires and Geocell. Plate loading tests were conducted for different reinforcing materials at the same condition. The combination of Tirecell and sidewall gives the highest increase of bearing capacity and reduction of settlement. The Geocell with the same hight of Tirecell gives similar reinforcement effect to the tire mat made by sidewalls.

• Structural Engineering and Mechanics
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• v.64 no.3
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• pp.287-292
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• 2017

In the present research, an available flexural stiffness degradation model was modified and a new comprehensive model called "X-NFSD" was developed. The X-NFSD model is capable of predicting the flexural stiffness degradation of composite specimen at different states of stresses and at room temperature. The model was verified by means of different experimental data for chopped strand mat/epoxy composites under displacement controlled bending loading condition at different displacements and states of stresses. The obtained results provided by the present model are impressively in very good agreement with the experimental data and the mean value of error of 5.4% was achieved.

• Journal of the Korean Society for Marine Environment & Energy
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• v.19 no.1
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• pp.47-51
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• 2016

It has made a special study of bending behavior of F.R.P. sandwich beams with bonded 2nd-reinforced plies. Specimen's faces were made of chopped mat 300-450, roving clothes 570, core is urethane foam, resin is 713bp unsaturated polyester for ship construction and the mixture weight ratio of resin versus fiber was 55:45 for bending analysis. The purpose of this paper is to study the exact bending behavior of bonded area's deflection and stiffness depends upon various bonded F.R.P. (2nd reinforced ply) length and thickness on which covered joints and to find the optimum design for the sandwich structures. All results and suggestions are based on experiment and using thick face calculation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.10
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• pp.1460-1466
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• 2012

The purpose of this study was to evaluate plasticizer pollution levels in mudflat solar salt, salt water and sea water of the nationwide saltpan. Also, it was analyzed the relationship between DEHP in solar salt and PVC mat following private period. DEP (ranging from 0.00 to 1.55 ppb), DIBP (0.00~2.38), DBP (0.00~4.90), DEHA (0.00~2.32), and BBP (0.00~1.45) in solar salt were shown a extremely low concentrations, and DEHP was present a concentrations ranging from 0.00 to 268.5 ppb in solar salt. Further, DMP, DPrP, DNPP, DNHP, and DCHP were not detected in all solar salt. Phthalate in sea water and salt water was present a infinitesimal amount levels. DEHP levels in sea water and salt water were not shown a high risk levels ranging from 0.00 to 3.4 ppb, and from 0.00 to 21.4 ppb, respectively. As expected in PVC mat of nationwide saltpan, the correlation between DEHP in solar salt and PVC mat private period showed a low positive correlation coefficient ($r^2$=0.0362).

• Journal of the Korean Mathematical Society
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• v.48 no.2
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• pp.301-309
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• 2011

Let R = $Mat_2(F)$ be the ring of all 2 by 2 matrices over a finite field F, X the set of all nonzero, nonunits of R and G the group of all units of R. After investigating some properties of orbits under the left (and right) regular action on X by G, we show that the graph automorphisms group of $\Gamma(R)$ (the zero-divisor graph of R) is isomorphic to the symmetric group $S_{|F|+1}$ of degree |F|+1.

• Korean Journal of Plant Resources
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• v.28 no.6
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• pp.743-751
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• 2015

Reynoutria japonica and R. sachalinensis have been used as medicinal resources in Korea. However, it is difficult to identify and determine these medicinal herbs correctly because they are usually customized and purchased as the fragmented rhizomes types. To develop molecular markers for distinguishing two species, we analyzed and compared the chloroplast DNA sequences of seven loci (atpB, matK, ccD-psaI, atpF-H, trnL-trnF, psbK-I and rpl32-trnL). Among them, we found two effective SNPs in psbK-I region for R. japonica and atpF-H region for R. sachalinensis. Based on these SNP sites, we designed the new R. japonica- specific primer which is able to amplify 300 bp fragment in psbK-I region. A similar strategy was applied for the atpF-H region of R. sachalinensis. These molecular markers would be successfully applied to recognize R. japonica and R. sachalinensis.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2000.10a
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• pp.47-52
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• 2000

F.R.P specimens were made by mixture CM(chopped mat) 450-104 matrix & RC(roving clothes)570-100 Roving, the mixture ratio Resin: hardener (92:8) for tensile test. It was also made of plates by hand lay-up method and was been cured for 24 hours and then was cut tensile specimens in accordance with ASTM D638 Type 3. Knowing exact behavior of bonded area's stress and strain when the tensile test was going on, the test specimens were made of 2 plies laminae of F.R.P in each for supporting cut part in middle of specimen length. And in middle part also were covered of F.R.P plies of 1/2, 2/3 length of specimen in each as well. Also we consider shear stress in adhered area. This study reveals that as plys length is more longer, rupture stress grows remarkably larger.