• Korean Journal of Soil Science and Fertilizer
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• v.23 no.4
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• pp.259-267
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• 1990

This study was carried out by investigating the changes of physico-chemical and mechanical properties of Gwanghwal and Poseung series in order to obtain basic information on the soil improvement and management. 1. In Gwanghwal series, the content of salt in soil and ground water before rice transplanting at the 21st year after reclamation were 0.29 and 1.02 percent respectively, and the safty cultivation of paddy rice was possible after 33 years of reclamation in both soil series. 2. Clay contents. atterberg limits and clay activity according to the age of reclaimation showed negative correlation. but sand content and N-value were positive in them. 3. Cone index was lower than $3kg/cm^2$ for the first 5 years after reclaimation in both soil series, and the formation of hard pan were 33rd and 49th year after reclamation in Gwanghwal and Poseung series respectively, and its thickness was more in Poseung than in Gwanghwal series. 4. Shearing resistance decreased with the age of reclaimation in both soil series. and friction resistance increased in Gwanghwal than Poseung siries. 4. Shearig resistance decreased with the age of reclaimation in both soil series, and friction resistance increased in Gwanghwal than Poseung series. 5. Soil pH. available, $SiO_2$, $Mg^2$, $K^+$, $Na^+$ and C. E. C showed negative correlation. with the year cultivated paddy rice. but O. M. ava ilable $P_2O_5Ca^{2+}$ and T-N had positive one in both soil series. Contents of O. M and $Ca^{2+}$ and T-N had positive one in both soil series. Contents of O. M and $Ca^{2+}$ were high in Gwanghwal, but C. E. C. was in Poseung series.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.618-625
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• 2018

With the passing of time, exposed concrete structures are affected by a range of environmental, chemical, and physical factors. These factors seep into the concrete and have a deleterious influence compared to the initial performance. The importance of identifying and preventing further performance degradation due to the occurrence of deterioration has been greatly emphasized. In recent years, evaluations of the target life have attracted increasing interest. During the freezing-melting effect, a part of the concrete undergoes swelling and shrinking repeatedly. At these times, chloride ions present in seawater penetrate into the concrete, and accelerate the deterioration due to the corrosion of reinforced bars in the concrete structures. For that reason, concrete structures located onshore with a freezing-melting effect are more prone to this type of deterioration than inland structures. The aim of this study was to develop a high performance mortar mixed with a mineral admixture for the durability properties of concrete structures near sea water. In addition, experimental studies were carried out on the strength and durability of mortar. The mixing ratio of the silica fume and meta kaolin was 3, 7 and 10 %, respectively. Furthermore, the ultra-fine fly ash was mixed at 5, 10, 15, and 20%. The mortar specimens prepared by mixing the admixtures were subjected to a static strength test on the 1st and 28th days of age and degradation acceleration tests, such as the chloride ion penetration resistance test, sulfuric acid resistance test, and salt resistant test, were carried out at 28 days of age. The chloride diffusion coefficient was calculated from a series of rapid chloride penetration tests, and used to estimate the life time against corrosion due to chloride ion penetration according to the KCI, ACI, and FIB codes. The life time of mortar with 10% meta kaolin was the longest with a service life of approximately 470 years according to the KCI code.

• Korean Journal of Environment and Ecology
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• v.23 no.1
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• pp.90-98
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• 2009

Every spring, Korea is always plagued by sandy dust from the western region of China and Mongolia. Yellow sand is causing an environmental problem to Japan and far into the American continent, let alone Korea. At present, the western region of China is going under desertification at a great speed due to climatic change and humans' damaging activities. To cope with this, each country including China is considering ecological restoration of deserts through planting. Accordingly, this research conducted a vegetation survey on Baicheng district which is a representative dry land of western China to obtain a basic data for ecological restoration of a desert. The survey revealed that Setaria viridis which invaded an arid land made a succession into Setaria viridis-Cannabis sativa var. fruderalis community together with Artemisia mongolica-Setaria viridis community due to the increase in salt concentration and alkalization subsequent to dryness. It was also found out that there finally formed Artemisia mongolica community on a flat intense in harsh wind and dryness with the continuous worsening of environmental conditions. There appeared a different type of vegetation on hilly districts where sporadic shade could come into being because the air humidity could be available relatively there. Frequently, typically appearing at the whole survey area, the Tributlus terrestris community was found to make succession into Tribulus terrestris-Cleisrogenes squarrosa community due to the aggravation of soil environment. In addition, with the worsening of the environment at hilly districts, there formed Clesirogenes squarrosa community resistant to dryness, salinity in soil and strong alkalinity. Further, there appeared higher plant life totalling to 62 taxa comprising 58 species and 4 varieties with 27 families and 49 genuses at the whole survey area. Among these, Compositae plants excellent in resistance to environment was surveyed the most, accounting for 27%.

• Journal of the Korean Wood Science and Technology
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• v.47 no.2
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• pp.163-177
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• 2019

This study aims to review the relations between the dyeing conditions (i.e., dye concentration, addition amounts of salt and alkali, and dyeing temperature) and dyeing properties and color fastness to light for identifying the optimal dyeing conditions when dyed regenerated woody fibers were obtained through the defibration of waste medium density fiberboard (MDF) using reactive Red H-E3B (Bis-monochlorotriazine (MCT)/MCT type) and reactive Red RB133% (Bis-MCT/Vinyl sulphone type). The dyeing yield (K/S) obtained using two types of reactive dyes increased as the dye concentration increased by 1-10% (on the weight of fiber (OWF)). In addition, the K/S of H-E3B was higher than that of RB133% irrespective of the dye concentration. The color difference of H-E3B after ultraviolet (UV) radiation was lower than that of RB133%, denoting good resistance to discoloration by UV. As the amount of sodium sulfate increased, the color difference and K/S also increased, and the adequate salt content was determined to be 50-70 g/L. Further, the color difference and K/S significantly increased only the addition of 2 g/L of sodium carbonate; however, almost no difference was observed when more than 2 g/L of sodium carbonate was added. The addition amount of sodium carbonate was adequate 5-10 g/L to dyeing the fiber and the pH at this addition level was 10. The dyeing yield of H-E3B increased when the dyeing temperature increased; however, it subsequently decreased after the dyeing temperature became $80^{\circ}C$. The dyeing yield of RB133% was almost the same up to $60-70^{\circ}C$ but declined subsequently. Thus, the adequate temperatures were $80^{\circ}C$ and $60^{\circ}C$ for H-E3B and RB133%, respectively. If the waste MDF woody fiber was dyed under the aforementioned optimal conditions, dyed regenerated woody fiber can be obtained having the following colors: 1.5 to 2.0R with the H-E3B dye and 9.6 to 10.0 PR with RB133%.

• Journal of Life Science
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• v.25 no.8
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• pp.910-916
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• 2015

Scientists have recently shown an interest in the characteristics of Bacillus mojavensis strains because of their increasing use in plants as a defense against diseases and mycotoxins. We have shown here that B. mojavensis KJS-3 possesses the typical characteristics of B. mojavensis strains including a strong resistance to high temperatures (≤50℃), tolerance to high salt concentrations (7% NaCl), ethanol tolerance (40% ethanol), and pH range for growth (pH 5-9). B. mojavensis KJS-3 has been used for the production of cyclic lipopeptides including important antifungal substances such as surfactin, iturin, and fengycin. Polymerase chain reaction analysis in this study showed that B. mojavensis KJS-3 can be used for the production of fengycin and the findings of LC-MS/MS analyses suggest that B. mojavensis KJS-3 can be used to produce iturin and surfactin. Antifungal activity analys is confirmed that B. mojavensis KJS-3 has antifungal effects on Botrytis cinerea, Rhizoctonia solani AG-4, Sclerotinia sclerotiorum, and Colletotricum goeosporioides. A microscopy assessment of the roots of wild ginseng plants planted together with B. mojavensis KJS-3 revealed that the roots contained B. mojavensis KJS-3, confirming the bacteria to be a plant growth promoting endophyte (PGPE) which acts against plant diseases and mycotoxins. Our findings lead us to conclude that B. mojavensis KJS-3 can be produced at an industrial level as a microbial pesticide or microbial fertilizer.

• Journal of Life Science
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• v.28 no.3
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• pp.376-387
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• 2018

Among a variety of environmental stresses heat, cold, chilling, high salt, drought, and so on exposed to plants, drought stress has been reported as a crucial factor to adversely affect the growth and productivity of plants. Therefore, to understand the mechanism for the drought stress signal transduction pathway in plants is more helpful to develop useful crops that display the enhanced tolerance against drought stress, and to expand crop growing areas. The signal transduction pathway for the drought stress in plants is largely categorized into two types; ABA-dependent pathway and ABA-independent pathway. It has been reported that two transcription factors, AREB/ABF and DREB2, play predominant roles in ABA-dependent and ABA-independent pathways, respectively. In addition to transcriptional regulation mediated by AREB/ABF and DREB2 transcription factors, post-translational modification (such as phosphorylation and ubiquitination) and epigenetic control are importantly involved in the signal transduction for drought stress. In this paper, we review current understanding of signal transduction pathway on drought stress in plants, especially focusing on the biological roles of a variety of signaling components related to drought stress response. Further understanding the mechanism of drought resistance in plants through this review will be useful to establish theoretical basis for developing drought tolerant crops in the future.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.10
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• pp.1490-1499
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• 2016

In this study, 69 lactobacilli isolated from Tibetan Qula, a raw yak milk cheese, were screened for their potential use as probiotics. The isolates were tested in terms of: Their ability to survive at pH 2.0, pH 3.0, and in the presence of 0.3% bile salts; tolerance of simulated gastric and intestinal juices; antimicrobial activity; sensitivity against 11 specific antibiotics; and their cell surface hydrophobicity. The results show that out of the 69 strains, 29 strains (42%) had survival rates above 90% after 2 h of incubation at pH values of 2.0 or 3.0. Of these 29 strains, 21 strains showed a tolerance for 0.3% bile salt. Incubation of these 21 isolates in simulated gastrointestinal fluid for 3 h revealed survival rates above 90%; the survival rate for 20 of these isolates remained above 90% after 4 h of incubation in simulated intestinal fluid. The viable counts of bacteria after incubation in simulated gastric fluid for 3 h and simulated intestinal fluid for 4 h were both significantly different compared with the counts at 0 h (p<0.001). Further screening performed on the above 20 isolates indicated that all 20 lactobacilli strains exhibited inhibitory activity against Micrococcus luteus ATCC 4698, Bacillus subtilis ATCC 6633, Listeria monocytogenes ATCC 19115, and Salmonella enterica ATCC 43971. Moreover, all of the strains were resistant to vancomycin and streptomycin. Of the 20 strains, three were resistant to all 11 elected antibiotics (ciprofloxacin, erythromycin, tetracycline, penicillin G, ampicillin, streptomycin, polymyxin B, vancomycin, chloramphenicol, rifampicin, and gentamicin) in this study, and five were sensitive to more than half of the antibiotics. Additionally, the cell surface hydrophobicity of seven of the 20 lactobacilli strains was above 70%, including strains Lactobacillus casei 1,133 (92%), Lactobacillus plantarum 1086-1 (82%), Lactobacillus casei 1089 (81%), Lactobacillus casei 1138 (79%), Lactobacillus buchneri 1059 (78%), Lactobacillus plantarum 1141 (75%), and Lactobacillus plantarum 1197 (71%). Together, these results suggest that these seven strains are good probiotic candidates, and that tolerance against bile acid, simulated gastric and intestinal juices, antimicrobial activity, antibiotic resistance, and cell surface hydrophobicity could be adopted for preliminary screening of potentially probiotic lactobacilli.

• Journal of Plant Biology
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• v.14 no.4
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• pp.27-33
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• 1971

Information this research an attempt was made to investigate the plant community structure and the process of its formation in the tidal area surrounding Mokpo City the examined area included the stand in Sam-Hak Do wherein sands have inflowed, and the stand in Kat-Ba-Woo which has been left as tidal soil land. Two hundred stands were sampled by making 100m line transects 5m apart and establishing 30cm$\times$30cm quadrates 10m apart on each tape. These data were used to establish frequency, cover degree, density, standing crop (g/$m^2$), contained Cl in the soil, and pH. Results of the research are as following: 1. There were 25 species of plants in the stands from Sam-Hak Do, 18 in the stands from Kat-Ba-Woo, and so 28 species in all. Regardings the importance value, the rank of dominant species is Salicornia herbacea L., Suaeda maritima Dumorties, Diplachne fusca L., Echinochola hispidula Nakai, Cyperus iria L., Setaria lutescens Hubbard in Sam-Hak Do, and Suaeda maritima Dumorties, Echinochloa hispidula Nakai, Aster tripolium L., Scripus maritimus L., Salicornia herbacea L., Diplachne fusca L., in the lands from Kat-Ba-Woo. Among them are five kinds of halophytes Salicornia herbacea L., Suaeda maritima Dumorties, Atriplex Gmelini C.A. Meyer, Aster tripolium L., and Limonium tetragonum Bullock; and two Kinds of naturalized plants Diplachan fusca L., Aster subulata. M. In the stands from Sam-Hak Do there was evidence of a secondary succession phenomena in the presence of Cyperaceae such as Cyperus liria L., Juncus decipiens Nakai, and Fimbristylis longispica Steudal, which could not be found in the stands from Kat-Ba-Woo. 2. On the number of species of vegetation, the further inland from the floodgate the higher the number; that is, the lower the content of Cl the higher the number of species. 3. On the distribution of the vegetation; comparing DFD index and Cl content, the main plants are Salicornia herbacea L., Suaeda maritima Dumorties, Atriplex gmelini C.A. Meyer, Diplachne fuscal, Echinochola hispidula Nakai where the Cl content of soil is more than 13.2%. 4. On the standing crop; Salicornia herbacea L., which has high resistance to salt, was half the total was production of 1090/$m^2$ while Suaeda maritima Dumorties was 1/4, Diplachne fusca L. 1/8, and Echinochloa the least. Analyzing the result, the research indicates that the main factor in plant community formation in tidal land is tolerance for Cl, and that a plan for utilizing the halophytes which are abundant in tidal land should be devised.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.6
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• pp.453-458
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• 2002

High temperature sterilization method (30min. at $40^{\circ}C$longrightarrow30 min. at $70^{\circ}C$longrightarrow30 min. cooling at $20^{\circ}C$) was evaluated better than that of chloride, ion water, $O_3$ water, and salt water for the controling of micro-organisms at the early stage of sprout culture. Due to the improved germination rate and effective control of micro-organisms at early stage, the method resulted in much lower in the number of micro-organisms, higher in sprout yield, and 2 days longer in quality keeping at market than sprouts prepared by conventional method. There are two methods related with water temperature; constant temperature method (18.5$\pm$ $0.5^{\circ}C$) which keeps the same water temperature during the culture and 3-stage temperature method which changes the water temperature depending on the days after culture. Three-stage temperature method set the temperature at 21$\pm$ $1^{\circ}C$) in the second and third days after the initial acceleration of germination (about 4 hours), at 18.5$\pm$0.5$^{\circ}C$ in the fourth and fifth days, and at 17.0$\pm$ $0.5^{\circ}C$) in the sixth and seventh days. Three-stage temperature method could enhance the resistance power to diseases at the early growth stage, control the growth to standard goods (8-9cm in length and 2.15-2.30mm in width), and keep good body color at the middle or final stage. This method also increased the sprout yield by 6% compared with the conventional method, constant temperature method.

• Journal of Life Science
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• v.24 no.11
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• pp.1231-1237
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• 2014

The objective of this study was to evaluate the safety and functional properties of four potential probiotic strains isolated from Kimchi, traditional Korean fermented vegetables. Based on being higher tolerance to bile salts and showing higher acid resistance or hydrophobic properties, one Lactobacillus arizonensis strain (BCNU 9032) and three L. brevis strains (BCNU 9037, BCNU 9098 and BCNU 9101) were selected in the screening experiment. All strains can survived up to 99% after 3h culture in pH 2.5 and resistant to 1% bile salts. These strains also showed good antimicrobial activities against a number of food borne pathogens, especially against Escherichia coli and Shigella sonnei. The ability to lower cholesterol levels of L. arizonensis BCNU 9032 and L. brevis 9037 were demonstrated by bile salt hydrolytic activity and cholesterol assimilation tests. Moreover, L. brevis BCNU 9098 and BCNU 9101 showed higher adherence to Caco-2 cells (12.76 and 11.86%, respectively) than Lactobacillus rhamnosus GG, a commercial probiotic strain used worldwide. The results suggest that these strains could be used as probiotics.