• Korean Journal of Materials Research
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• v.28 no.9
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• pp.528-533
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• 2018

In recent years, solar cells based on crystalline silicon(c-Si) have accounted for much of the photovoltaic industry. The recent studies have focused on fabricating c-Si solar modules with low cost and improved efficiency. Among many suggested methods, a photovoltaic module with a shingled structure that is connected to a small cut cell in series is a recent strong candidate for low-cost, high efficiency energy harvesting systems. The shingled structure increases the efficiency compared to the module with 6 inch full cells by minimizing optical and electrical losses. In this study, we propoese a new Conductive Paste (CP) to interconnect cells in a shingled module and compare it with the Electrical Conductive Adhesives (ECA) in the conventional module. Since the CP consists of a compound of tin and bismuth, the module is more economical than the module with ECA, which contains silver. Moreover, the melting point of CP is below $150^{\circ}C$, so the cells can be integrated with decreased thermal-mechanical stress. The output of the shingled PV module connected by CP is the same as that of the module with ECA. In addition, electroluminescence (EL) analysis indicates that the introduction of CP does not provoke additional cracks. Furthermore, the CP soldering connects cells without increasing ohmic losses. Thus, this study confirms that interconnection with CP can integrate cells with reduced cost in shingled c-Si PV modules.

• The Korean Journal of Mycology
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• v.43 no.2
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• pp.112-117
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• 2015

To investigate the changes of the resistance to prochloraz of Fusarium species causing bakanae disease, Fusarium isolates were collected from various regions in Korea, and pathogenicity tests were performed using rice seeds. Minimum inhibitory concentration (MIC) and effective concentration of 50% ($EC_{50}$) values of isolates were determined using the agar dilution method. High frequency distribution of MIC values of prochloraz against isolates collected in 2006~2007 and 2013~2014 years were $3.125{\sim}6.25{\mu}g/mL$ and $6.25{\sim}12.5{\mu}g/mL$, respectively. The mean $EC_{50}$ value of isolates increased from $0.3142{\mu}g/mL$ in 2006~2007 to $0.8124{\mu}g/mL$ in 2013~2014. Based on the $EC_{50}$ value of isolates collected in 2006~2007, the resistant baseline of prochloraz was determined as $0.6{\mu}g/mL$. Compared with the ratio of resistant isolates in 2006~2007, the ratio of resistant isolates in 2013~2014 increased from 6.5% to 41.6%.

• Nuclear Engineering and Technology
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• v.27 no.3
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• pp.393-402
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• 1995

The structural analysis of the reactor coolant system mainly consist of too fields. The one is the static analysis considering the impact of pressure and temperature built up during normal operation. The other is the dynamic analysis to estimate the impact of postulated events such as the seismic loads or postulated branch line pipe breaks event. Since the most important goal of the RCS structural analysis is to prove the safety of the RCS during normal operation or postulated events, a widely proven theory having enough conservatism is adopted. The load occurring on the RCS during normal operation is considered as the basic design loading condition throughout whole plant life time. The most typical characteristic of the RCS during normal operation is the thermal expansion of the RCS caused by reactor coolant with high temperature and pressure. Therefore, the exact estimation on the thermal movement of the RCS is needed to get more clear understanding on the thermal movement behavior of the RCS. In this study, the general structural analysis concept and modeling method to evaluate the thermal movement of the RCS under the normal plant operation condition are presented. To discuss the validation of the suggested analysis, analysis results are compared with the measured data which ore referred from the standardized 1000 MWe PWR plant under construction.

• Korean Journal of Veterinary Research
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• v.41 no.2
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• pp.177-188
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• 2001

Mastitis is one of the most significant cause of economic loss to the dairy industry. Especially, Staphylococcus aureus is a major contagious mastitis-causing pathogen in dairy cattle. Because of its high transmission rate and resistance to antibiotic therapy, staphylococcal mastitis presents a constant threat to the dairy industry. Staphylococcal enterotoxin C(SEC) produced by S aureus has been known as one of superantigens which are able to stimulate a large proportion of T lymphocytes independently of their antigenic specificity. In this experiment, we have conducted preliminary studies with mice and lactating cows to evaluate the immunogenicity and safety of the experimental vaccine consists of SEC mutant antigen on controlling the bovine mastitis associated with S aureus infections. The average value of somatic cell counts in quarter milk, isolation rate of S aureus were consistently decreased in SEC-SER vaccinated groups, whereas antibody titers were highly increased in SEC-SER vaccinated groups. Peripheral blood were also collected from the lactating cows to determine the proportion of leukocyte subpopulation associated with humoral immunity(HI) and cell mediated immunity(CMI). Proportion of leukocyte subpopulation expressing $BoCD2^+$(total T lymphocyte), $BoCD4^+$(T helper cell), $BoCD8^+$(T cytotoxic/suppressor cell) and NonT/NonB lymphocyte which are involved in CMI in SEC-SER vaccinated groups were decreased for the initial stage after first vaccination and then increased from ten weeks after first vaccination maintaining elevated level till 14 weeks after vaccination. In contrast, proportion of monocyte, MHC class II and B lymphocyte which are associated with the production of primary immune response in SEC-SER vaccinated groups were increased for the initial period and then decreased from ten weeks after first vaccination. We present evidence that vaccination of SEC-SER mutant antigen in lactating cows induced a significant proliferation of bovine T lymphocytes. These results suggest that SEC-SER mutant antigen used in this experiment might be one of potential immunogen in developing innovative vaccine against bovine IMI associated with S aureus. Additional challenge trials should be carried out to evaluate substantial protection against S aureus under the commercial farm conditions.

• Korean Journal of Microbiology
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• v.52 no.1
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• pp.74-83
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• 2016

Bacillus subtilis SRCM 101269 having safety and amo gene isolated from Korean traditional fermented food and their investigated characterization to apply the cow manure such as cellulase and xylanase activities, 16S rRNA sequencing, and ability of removal of livestock manure odor. Cow manure application results for the removal of livestock manure odor, the ammonia gas was reduced more than two-folder compared to the control group after 6 days, and reduced to less than 10 ppm after 9 days. In the case of cow manure added fowl droppings and other wood-based mixture components, ammonia gas maintained constant after 3 days of fermentation. However, in the case of sample inoculated B. subtilis SRCM 101269, ammonia gas reduced in course of fermentation time, and concentration of hydrogen sulfide also reduced for 65 ppm. Changes of nitrite concentration according to fermentation time no showed different for cow manure, however nitrite concentration in mixed livestock manure increased when compared to control. And then sulfate concentration in cow manure decreased, and no showed different when compared to the initial fermentation. No apparent change of sulfate concentration in mixed livestock manure detected. Through the previously studies, B. subtilis SRCM 101269 has high potential in industrial application manufacturing the cow manure as removal of livestock manure odor.

• The Korean Journal of Food And Nutrition
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• v.28 no.4
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• pp.728-736
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• 2015

Cronobacter species (Cronobacter spp.), previously known as Enterobacter sakazakii, are gram negative food borne pathogenic bacteria. They pose a very high risk of infection to neonates and immuno-compromised individuals and can affect the human central nervous system. Consequently, survivors often suffer from severe neurological impairment including hydrocephalus, quadriplegia, and developmental delays. Cronobacter spp. were not only isolated from plant food and products such as cereals, fruits, vegetables, legume products, herbs, and spices but also from animal source foods such as milk, meat, fish, and products made from these foods. Therefore, rapid detection of Cronobacter spp. is essential for food safety. Many detection methods have been developed since the Cronobacter spp. were first reported. However, the development of more rapid, sensitive, and easy-to-use detection methods for the Cronobacter spp. is required. In this review, our aim was to study and compare the available detection methods for Cronobacter spp., including culture-based, molecular biology-based, and immunology-based methods. This study will contribute to the development of new and rapid detection method for Cronobacter spp.

• Fire Science and Engineering
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• v.33 no.4
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• pp.16-27
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• 2019

A burning test was conducted on the smoke and combustion gases generated from cypress wood treated with sodium silicate, 3-aminopropyltrimethoxysilane sol, 3-(2-aminoethylamino)propylmethyldimethoxysilane sol, and 3-(2-aminoethylamino) propyltrimethoxysilane sol. The silicone compound sol was applied to each of the cypress wood specimens three times with a brush. The smoke and combustion generation gas were analyzed using a cone calorimeter (ISO 5660-1) and the smoke was also evaluated by applying new smoke risk assessment method. The smoke performance index (SPI) of the cypress treated with silicone compound increased 1.66 to 8.42 times and the smoke growth index (SGI) was 11.8 to 88.2%, respectively. The smoke intensity (SI) is expected to be 1.0~50.5% lower than that of the base specimens, resulting in lower smoke and fire hazards. The third maximum carbon monoxide (CO_peak) concentration of the specimens treated with silicone compounds was 22.5~33.3% lower than that of the base specimens. On the other hand, it produced potentially fatal toxicity that was 1.48~1.72 times higher than the US Occupational Safety and Health Administration (OSHA) acceptance standard (PEL). Cypress wood itself produced a high carbon monoxide concentration, but the silicon compound played a role in reducing this level.

• Korean Journal of Food Science and Technology
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• v.26 no.4
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• pp.422-427
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• 1994

The quality of salted and semi-dried mackerel prepared by cold osmotic dehydration using a high osmotic pressure resin during storage at $5{\pm}1^{\circ}C$ was evaluated. The moisture contents in salted and semi-dried mackerel decreased in. range of 4 during storage. The brown pigment formation content and peroxide value of salted and semi-dried mackerel prepared by osmotic dehydration were more lower than those of salted and semi-dried mackerel prepared by traditional drying methods such as sun-drying, hot-air drying and cold air drying. The viable cell count and histamine contents of cold osmotic dried products were much lower and revealed a tendency to increase during storage, but even these values after storage of 15 days showed that the salted and semi-dried mackerel was safety in respect of food sanitation. The ratio of saline soluble nitrogen to total nitrogen in cold osmotic dried products were higher than that of traditional dried products during storage. Judging from the results of chemical and sensory evaluation, shelf-life of salted and semi-dried mackerel by cold osmotic drying were more longer than that of salted and semi-dried mackerel prepared by traditional drying.

• Journal of Wetlands Research
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• v.22 no.4
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• pp.295-301
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• 2020

This research analyzed the relationship between environmental factors and the density of Sycios angulatus in the Miho Stream, Geum River water system in order to secure basic data for the control of the ecosystem-distrubing plant Sycios angulatus. As a result of the soil particle size analysis of Sycios angulatus habitat, it was found that the density of Sycios angulatus decreased as the silty and clay contents increased. Most of the Sycios angulatus habitats had high sandy and silt content, and low clay content of less than 2%. The increased flow rate reduced the density of Sicyos angulatus. This is because when the flow rate is increased, the Sicyos angulatus cannot grow due to the change in soil characteristics. Water quality plays a role in supplying nutrients when Sicyos angulatus are submerged. However, due to the change in soil characteristics during flooding, the density of Sicyos angulatus tended to decrease due to impaired growth. The Sicyos angulatus can be managed through artificial and natural techniques. The appropriate natural control technique is the creation of a natural waterway in the habitats to change the water contents.

• Journal of Korea Water Resources Association
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• v.53 no.spc1
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• pp.755-764
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• 2020

In South Korea, 850 standard watersheds and 7,807 KRF catchment areas have been used as basic maps for water resources policy establishment, however it becomes necessary to set up new standard maps with a more appropriate scale for the integrated managements of surface water-groundwater as well as water quantity-quality in the era of integrated water management. Since groundwater has a slow flow velocity and also has 3-D flow properties compared to surface water, the sub-catchment size is more effective than the regional watershed for the evaluation of surface water-groundwater interaction. The KRF catchment area, which has averagely a smaller area than the standard watershed, is similar to the sub-catchment area that generally includes the first-order or second-order tributaries. Some KRF catchment areas, which are based on the surface reach, are too small or large in a wide plain or high mountain area. Therefore, it is necessary to revise the existing KRF area if being used as a unit area for integrated management of surface-water and groundwater. A unit watershed with a KRF area of about 5 to 15 ㎢ can be effective as a basic unit for water management of local government considering a tributary composition and the location of groundwater wells, and as well it can be used as a basic tool for water demand-supply evaluation, hydrological observation system establishment, judgment of groundwater permission through a total quantity management system, pollution assessment, and prioritizing water policy, and etc.