• Journal of the Korean Geotechnical Society
• /
• v.30 no.12
• /
• pp.51-61
• /
• 2014

This paper presents an experimental study of the plugging effect on the capacity of open-ended piles installed in sandy soil. Full-scale tests, including dynamic and static axial-compression load tests, were carried out on three instrumented piles with different diameters (508.0, 711.2 and 914.4 mm). To measure the outer and inner shaft resistances acting on the piles, a double-walled system was utilized with instrumented strain gauges on the outside and inside walls of the pile. The results of field tests show that the inner shaft resistance was mostly mobilized at the location between the pile tip and 18-34% of the total plug length. It was found that the soil plugging in the lower portion has influence on the inner shaft resistance. In addition, it can be also demonstrated that the ratio of inner shaft resistance plus annulus load resistance to total resistance decreased with increasing pile diameters. The results of these tests show that the relationship between the degree of plugging and pile diameter is clearly established. Direct observations of the soil plugs were made and used to quantify both the plug length ratio (PLR) and the incremental filling ratio (IFR). Based on this result, it was found that the N value of the standard penetration test (SPT) is highly correlated with the IFR.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.43 no.5
• /
• pp.749-755
• /
• 2014

Exopolysaccharides (EPSs) have been widely used in the food industry as viscofying, stabilizing, and emulsifying agents as well as in the pharmaceutical industry for their immunomodulatory, anti-tumor, and anti-inflammatory effects. A total of 458 lactic acid bacteria (LAB) strains isolated from several kinds of soybean pastes were screened for the production of homo-EPS (HoPS). LAB isolates were primarily screened using thin layer chromatography (TLC) and further screened polymerase chain reaction (PCR) targeting genes involved in HoPS production. Six LAB isolates producing high amounts of HoPS were identified by TLC. Among these isolates, glucansucrase gene was amplified in two strains (JSA57, JSB22), whereas the fructansucrase gene was detected in three strains (JSA57, JSB22, JSB66). After isolating the strains, their morphological characteristics and 16S rDNA sequences were determined. Six species were identified as L. alimentarius HSB15, L. plantarum JSA22, L. pentosus JSA57, L. brevis JSB22, L. alimentarius JSB66, and L. parabrevis JSB89. To evaluate the potential probiotic properties of these LAB, their survival rates against a simulated intestinal environment were determined. After 2 hr of incubation in artificial gastric juice, survival rates of JSA57, JSB90, JSB22, and JSB66 were all greater than 50%. After 2 hr of incubation in bile juice, viable cell count of JSB22 was similar with initial vial cell counts. Growth of the six LAB was screened in arabino-oligosaccharide (AOS)-containing MRS broth. Results showed that growth of the isolates selectively increased after culture in AOS-containing media. Strain JSB22 (6 hr), JSB66 (6 hr), HSB15 (20 hr), and JSA22 (29 hr) showed maximum growth rate. Especially, JSB22 showed the highest growth rate. These results suggest that EPS-producing LAB isolated from Deonjang could be applied as synbiotics.

• Microbiology and Biotechnology Letters
• /
• v.16 no.6
• /
• pp.494-498
• /
• 1988

The optimum conditions for glucoamylase production, and ethanol productivity of the transformant TSD-14 were investigated as compared with the parental strains. The properties of TSD-14 were comparatively similar to the donor S. diastaticus IFO 1046 as regards the conditions of glucoamylase production and ethanol productivity. The soluble starch was the most effective carbon source for the glucoamylase production. While inorganic nitrogen sources did not prompt cell growth and enzyme production, the organic nitrogen sources generally enhanced both cell growth and glucoamylase production. The metal salts such as FeSO$_4$, MgSO$_4$, MnCl$_2$, and NiSO$_4$were favorable to the enzyme production. And the optium temperature and initial pH for glucoamylase production were 3$0^{\circ}C$ and 5. The transformant TSD-14 produced 8.3%(v/v) ethanol from 15% sucrose medium, 4.8%(v/v) ethanol from 15% soluble starch medium, and 7.5%(v/v) ethanol from 15% liquefied potato starch medium. The corresponding fermentation efficiency were 84% , 45% and 70%, respectively.

• Asian-Australasian Journal of Animal Sciences
• /
• v.29 no.7
• /
• pp.1052-1059
• /
• 2016

Red light (RL) marked higher weight gain (WG) and preference of broilers compared to other light colors. This study aimed to investigate how different intensities of RL affect the performance, behavior and welfare of broilers. RL treatments were T1 = high intensity (320 lux), T2 = medium intensity (20 lux); T3 = dim intensity (5 lux), T4 = control/white light at (20 lux) provided on 20L:4D schedule and T5 = negative control; 12 hours dark: 12 hours day light. Cobb strain broilers were used in a Complete Randomize Design with 6 replicates. WG, water/feed intake, feed conversion ratio (FCR), mortality, behavior and welfare were assessed. At 35 d, significantly (p<0.05) highest body weight ($2,147.06g{\pm}99$) was recorded by T3. Lowest body weight ($1,640.55g{\pm}56$) and FCR (1.34) were recorded by T5. Skin weight was the only carcass parameter showed a significant (p<0.05) influence giving the highest (56.2 g) and the lowest (12.6 g) values for T5 and T1 respectively. Reduced welfare status indicated by significantly (p<0.05) higher foot pad lesions, hock burns and breast blisters was found under T3, due to reduced expression of behavior. Highest walking ($2.08%{\pm}1%$) was performed under T1 in the evening during 29 to 35 days. Highest dust bathing ($3.01%{\pm}2%$) was performed in the morning during 22 to 28 days and highest bird interaction (BI) ($4.87%{\pm}4%$) was observed in the evening by T5 during 14 to 21 days. Light $intensity{\times}day$ $session{\times}age$ interaction was significantly (p<0.05) affected walking, dust bathing and BI. Light intensity significantly (p<0.05) affected certain behaviors such as lying, eating, drinking, standing, walking, preening while lying, wing/leg stretching, sleeping, dozing, BI, vocalization, idling. In conclusion, birds essentially required provision of light in the night for better performance. Exposed to 5 lux contributed to higher WG, potentially indicating compromised welfare status. Further researches are suggested to investigate RL intensity based lighting regimen that favors for both production and welfare of Broilers.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.23 no.1
• /
• pp.27-44
• /
• 1993

This study was performed to investigate the changes of mandibular condyle by low calcium diet and the effects of irradiation on the bone in osteoporotic state. In order to carry out this experiment, 80 seven-week old Sprague-Dawley strain rats weighing about 150 gm were selected and equally divided into one experimental group of 40 rats and one control group with the remainder. The experimental group and the control group were then subdivided into two group and exposed to irradiation. The two irradiation groups received a single dose of 20 Gy on the jaw area only and irradiated with a cobalt-60 teletherapy unit. The rats in the control and experimental groups were serially terminated by fours on the 3rd, the 7th, the 14th, and the 21st day after irradiation. After termination, both sides of the dead rats mandibular condyle were removed and fixed with 10% neutral formalin. The bone mineral density of mandibular condyle was measured by use of dual energy X-ray bone densitometer(model DDX-alpha, Lunn Corp., U. S. A.). The mandibular condyle was radiographed with Hitex HA-80(Hitex Co., Japan). Thereafter, the obtained radiographs were observed, and the mandibular condyle was further decalcified and embedded in paraffin as the general method. The specimen sectioned and stained with hematoxylin-eosin, PAS and Rabbit Anti-Human Tumor Necrosis Factor-a observed by a light microscope. The obtained results were as follows: 1. In the non-irradiated group with the low calcium diet, the bone mineral density of the condyle was markedly decreased after 14 days, and decrease the number of trabeculae of the condyle and resorption of the calcified cartilaginous zone were observed after 3 days. On microscopic observations, the number nd size of trabeculae were decreased after 7 days of experiment. 2. In the irradiated group with the low calcium diet, the bone mineral density of the condyle was markedly decreased after 14 days and resorption of the calcified cartilaginous zone and decrease the number and coarse of the trabeculae of the condyle were observed. These findings were extended rather than in non-irradiated group with low calcium diet. On microscopic observations, many osteoclasts were detected and the number and size of trabeculae were somewhat decreased after 7 days. Also there was degenerative changes of tissues of bone marrow on the 14th day but that condition was restored on the 21st day of experiment. 3. In the irradiated group with normal diet, the bone mineral density of the condyle was somewhat decreased with times and degree of decrease of the number of trabeculae was somewhat larger than in the non-irradiated group with normal diet. On microscopic observations, the tissues of bone marrow were atrophic and degenerative changes but that condition was restored on the 21st day of experiment. 4. In immunocytochemical findings, in the irradiated and non-irradiated groups with low calcium diet, negative or partial positive response to TNF was observed, but positive response in the normal diet groups.

• Membrane Journal
• /
• v.24 no.1
• /
• pp.10-19
• /
• 2014

Porous flat sheet membranes for separators in Zn air batteries were prepared with polyethersulfone (PES) solutions by immersion precipitation phase inversion method. PES/polyvinylpyrrolidone(PVP)/N-methylpyrrolidone(NMP) mixtures were used for casting solutions and water was used for coagulant. With the separators, Zn air batteries were fabricated. The separators were characterized by means of stress-strain test, impedance test and SEM. The Zn air batteries were tested by current interrupt method (CIM) and galvanostatic discharge method. The tensile strength increased with increasing PES content in the casting solution while the ionic conductivity decreased. On the other hand, the ionic conductivity increased while the tensile strength decreased with increasing PVP content. The effect of ionic conductivity trend of the separator in the Zn air battery was confirmed through current interrupt method and galvanostatic discharge method experiments. The battery with the separator from casting solution with higher PES content showed higher IR drop and lower discharge capacity. And the battery with the separator from casting solution with higher PVP content showed lower IR drop and higher discharge capacity.

• Proceedings of the Microbiological Society of Korea Conference
• /
• 2007.05a
• /
• pp.120-122
• /
• 2007

All living organisms use numerous signal-transduction pathways to sense and respond to their environments and thereby survive and proliferate in a range of biological niches. Molecular dissection of these signalling networks has increased our understanding of these communication processes and provides a platform for therapeutic intervention when these pathways malfunction in disease states, including infection. Owing to the expanding availability of sequenced genomes, a wealth of genetic and molecular tools and the conservation of signalling networks, members of the fungal kingdom serve as excellent model systems for more complex, multicellular organisms. Here, we employed Cryptococcus neoformans as a model system to understand how fungal-signalling circuits operate at the molecular level to sense and respond to a plethora of environmental stresses, including osmoticshock, UV, high temperature, oxidative stress and toxic drugs/metabolites. The stress-activated p38/Hog1 MAPK pathway is structurally conserved in many organisms as diverse as yeast and mammals, but its regulation is uniquely specialized in a majority of clinical Cryptococcus neoformans serotype A and D strains to control differentiation and virulence factor regulation. C. neoformans Hog1 MAPK is controlled by Pbs2 MAPK kinase (MAPKK). The Pbs2-Hog1 MAPK cascade is controlled by the fungal "two-component" system that is composed of a response regulator, Ssk1, and multiple sensor kinases, including two-component.like (Tco) 1 and Tco2. Tco1 and Tco2 play shared and distinct roles in stress responses and drug sensitivity through the Hog1 MAPK system. Furthermore, each sensor kinase mediates unique cellular functions for virulence and morphological differentiation. We also identified and characterized the Ssk2 MAPKKK upstream of the MAPKK Pbs2 and the MAPK Hog1 in C. neoformans. The SSK2 gene was identified as a potential component responsible for differential Hog1 regulation between the serotype D sibling f1 strains B3501 and B3502 through comparative analysis of their meiotic map with the meiotic segregation of Hog1-dependent sensitivity to the fungicide fludioxonil. Ssk2 is the only polymorphic component in the Hog1 MAPK module, including two coding sequence changes between the SSK2 alleles in B3501 and B3502 strains. To further support this finding, the SSK2 allele exchange completely swapped Hog1-related phenotypes between B3501 and B3502 strains. In the serotype A strain H99, disruption of the SSK2 gene dramatically enhanced capsule biosynthesis and mating efficiency, similar to pbs2 and hog1 mutations. Furthermore, ssk2, pbs2, and hog1 mutants are all hypersensitive to a variety of stresses and completely resistant to fludioxonil. Taken together, these findings indicate that Ssk2 is the critical interface protein connecting the two-component system and the Pbs2-Hog1 pathway in C. neoformans.

• Korean Journal of Microbiology
• /
• v.48 no.1
• /
• pp.1-7
• /
• 2012

This study explores the interaction between the production of indole-3-acetic acid (IAA), a typical phytohormone auxin and the role of IAA biosynthetic pathways in each IAA producing rhizobacterial strain. The bacterial strains were isolated from rhizosphere of wild plants and identified as Acinetobacter guillouiae SW5, Bacillus thuringiensis SW17, Rhodococcus equi SW9, and Lysinibacillus fusiformis SW13. A. guillouiae SW5 exhibited the highest production of IAA using tryptophan-dependent pathways among the 4 strains. When indole-3-acetamide (IAM) was added, Rhodococcus equi SW9 showed the highest IAA production of $3824{\mu}g/mg$ protein using amidase activity. A. guillouiae SW5 also showed the highest production of IAA using two pathways with indole-3-acetonitrile (IAN), and its nitrile hydratase activity might be higher than nitrilase. B. thuringiensis SW17 showed the lowest IAA production, and most of IAA might be produced by the amidase activity, although the nitrilase activity was the highest among 4 strains. The roles of nitrile converting enzymes were relatively similar in IAA synthesis by Lysinibacillus fusiformis SW13. Tryptophan-independent pathway of IAA production was utilized by only A. guillouiae SW5.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.12
• /
• pp.614-621
• /
• 2019

A generalized laminated composite beam element is presented for the flexural and buckling analysis of laminated composite beams with double and single symmetric cross-sections. Based on shear-deformable beam theory, the present beam model accounts for transverse shear and warping deformations, as well as all coupling terms caused by material anisotropy. The plane stress and plane strain assumptions were used along with the cross-sectional stiffness coefficients obtained from the analytical technique for different cross-sections. Two types of one-dimensional beam elements with seven degrees-of-freedom per node, including warping deformation, i.e., three-node and four-node elements, are proposed to predict the flexural behavior of symmetric or anti-symmetric laminated beams. To alleviate the shear-locking problem, a reduced integration scheme was employed in this study. The buckling load of laminated composite beams under axial compression was then calculated using the derived geometric block stiffness. To demonstrate the accuracy and efficiency of the proposed beam elements, the results based on three-node beam element were compared with those of other researchers and ABAQUS finite elements. The effects of coupling and shear deformation, support conditions, load forms, span-to-height ratio, lamination architecture on the flexural response, and buckling load of composite beams were investigated. The convergence of two different beam elements was also performed.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.34 no.10
• /
• pp.1606-1610
• /
• 2005

The effects of Whangkumtang extract and Scutellariae radix extract on the microbial growth were investigated. The antimicrobial activities and cell growth inhibiting effects were investigated to selected strains with different concentrations of Whangkmtang and Scutellariae radix extracts. Whangkmtang and Scutellariae radix extracts showed the antimicrobial activities on Staphylococcus aureus, Bacillus cereus, Shigella sonnei, Shigella flexneri, Salmonella Typhimurium, Salmonella Enteritidis, Vibrio parahaemolyticus, Escherichia coli O111 and Escherichia coli O126. Whangkumtang and Scutellariae radix extracts did not show the antimicrobial activity on Listeriamonocytogenes. Scutellariae radix extract showed the antimicrobial activity on Escherichia coli O157 but Whangkumtang extract did not, Minimum inhibitory concentrations (MIC) of Whangkumtang extract for each strain appeared to 40 mg/mL on Staphylococcus aureus and Bacillus cerus, 100 mg/mL on Shigella Flexneri and Salmonella enteritidis. The MICs of Sutellariae radix extract appeared to 10 mg/mL on Bacillus cereus, 20 mg/UL on Staphylococn aureus, Shigellanexneri and Salmonella Enteritidis. Scutellariae radix extract showed the higher antimicrobial activity than Whangkumtang extract. The cell growth inhibitions by Whangkumtang and Scutellariae radix extracts were observed from Staphylococcus aureus and Bacillus cereus, repectively, during 48-hr incubation period.