To improve the productivity of shiitake mushroom (Lentinula edodes), seven different types of media for liquid spawn (denoted as “A” to “G”) were prepared with 0.3% soybean meal and varying sugar and glucose concentrations. During 14 days of incubation, the pH of the liquid culture gradually acidified with increasing incubation period. Additionally, there was a significant, but not prominent, difference in the degree of acidification depending on the sugar to glucose ratio. Liquid spawn culture “G,” which had the highest sugar content was the most acidic on the last day of incubation. Mycelium dry weight increased significantly with increasing incubation period, and there was no significant difference in mycelium dry weight irrespective of the sugar to glucose ratio even after 14 days of culture. The inoculation of liquid spawn in sawdust medium with an inoculation volume ≥ 45 mL and incubation period of 15 to 18 days were the optimal culture conditions. Productivity of fruit bodies in sawdust medium and mushrooms treated with liquid spawn was significantly higher compared to solid spawn treatment. The mushrooms treated with liquid spawn had better chewiness, and the free amino acid content, which is associated with savory taste, was higher in these mushrooms compared to those treated with solid spawn.

친수성 및 소수성 나노실리카를 tetraethyl orthosilicate(TEOS)를 커플링제로 사용하여 유리 표면에 거친 스파이크 구조 형성과 반응성 hydroxyl기를 동시에 도입한 후 불소를 함유한 실란으로 2차 코팅처리하여 궁극적으로 발수성 유리 표면 형성의 최적 조건을 확립하는 연구를 수행하였다. 소수 성 나노실리카인 실리카 에어로졸을 이용한 초소수 도막의 형성은 나노실리카 표면에 반응성인 -OH기가 존재하지 않아 내구성이 있는 소수성 도막을 형성할 수 없었다. 이에 반하여 친수성기를 가진 나노 실리카와 가수분해된 TEOS를 포함하는 코팅액 이용하여 유리 표면을 1차 코팅한 후 2차로 trichloro-(1H,1H,2H,2H)perfluorooctylsilane(TPFOS) 용액으로 코팅하여 150o 이상의 수접촉각을 가지는 초소수 표면을 제조하였으며, 1o 이하의 물 슬라이딩각을 보여 초발수성도 동시에 가지고 있었다. 이에 덧붙여 친수성 나노실리카의 함량이 증가할수록 광투과도가 감소하였으며, TPFOS 용액에 의해서도 광투과도가 감소하였다. 코팅된 유리시편의 내구성 50회 문지름까지는 초소수성을 유지하였으나, 200회 문지름에서는 단지 소수성만을 유지하였다. 결론적으로 최적의 코팅액의 조건은 친수성 나노실리카의 함량이 0.3 g인 HP3 코팅액을 2회 코팅한 후 2차로 TPFOS 용액으로 코팅하는 것이었다. 이렇게 제조된 코팅액은 광투과도가 중요한 솔라셀의 표면 처리제로 사용이 가능할 것으로 판단된다.

Ice accumulation on Aluminum Conductor Steel Reinforced(ACSR) cable during winter is an important matter in terms of safety, economy, and efficient power supply. In this work, the ice adhesion strengths of ACSR cable oxidized during different periods(7 years oxidized and 15 years oxidized) are evaluated. At first, a plate type dry oxidation standard specimen, whose surface characteristics are similar to those of ACSR cable, is prepared. Dry oxidation standard specimens are heat-treated at 500 °C for 20, 60, and 120 minutes in order to obtain different degrees of oxidation. After the dry oxidation, surface properties are analyzed using contact angle analyzer, atomic force microscopy, spectrophotometer, and gloss meter. The ice adhesion strengths are measured using an ice pull-off tester. Correlations between the surface properties and the ice adhesion strength are obtained through a regression analysis indicating a Boltzmann equation. It is revealed that the ice adhesion strength of 15- year oxidized ACSR cable is approximately 8 times higher than that of ACSR-bare.

To enumerate Staphylococcus aureus in food, Baird-Parker Agar (BPA) is usually used in the conventional method, However it requires time and space for the preparation and plating, and incubation. Thus, use of the 3MTM PetrifilmTM Staph Express Count Plate (STX Petrifilm) might be appropriate to solve these challenging problems. The purpose of this study was to compare the efficiency of STX Petrifilm with BPA for enumeration of S. aureus in various foods. A mixture of S. aureus strains ATCC29213, ATCC25923, and ATCC13565 was inoculated on marinated pork chop, beef (chuck tender), dried filefish, semi-dried squid, rice cake, and Japchae (stir-fried glass noodles) at 2, 3, 5, and 7 Log CFU/g. S. aureus cell counts were enumerated by spread-plating on STX Petrifilm and BPA after 0 and 24 hours at 4oC (marinated pork chop, beef, semi-dried squid, and stir-fried glass noodles) and 25oC (dried filefish and rice cake). Recovery of STX Petrifilm for S. aureus from various food samples was compared with BPA, and the results showed that there were no significant differences between two selective media in all cases. The results indicated that STX Petrifilm had enough efficiency to recover S. aureus from various foods as well as saving time and space.

PURPOSES : This study was conducted to analyze the problems of the permeable block by objectively evaluating the quality of the permeable block and providing basic data to improve the quality and construction defect of the permeable block pavement in accordance with the continuously increasing demand of the permeable block. METHODS : In this study, we evaluated the current quality standard suitability of nine products to evaluate the current quality level of domestic production permeable blocks. The evaluation items were evaluated for surface layer thickness, block dimension, strength, and permeability coefficient, and the Korea Standard suitability for these evaluation items was analyzed. In addition, a three-dimensional finite element analysis was conducted to determine the effect of vehicle load on the deformation of block pavement structure. RESULTS : The results demonstrated that the surface layer (colored layer) thicknesses of domestically produced permeable block products were different according to the quality standards, and the dimensions were evaluated to be excellent for domestic permeable blocks currently being produced and delivered. In addition, the strength and permeability coefficient evaluation result demonstrated that all products meet the strength and permeability coefficient quality standards, but the correlation between these strengths and permeability coefficients is not high. The quality standard of strength and permeability coefficients is evaluated as being sufficiently achieved by domestic production technology. CONCLUSIONS: The intensity and permeability coefficients measured in this study were in line with the quality standards; however, the variable coefficient was found to have a significant difference in the quality control level from a maximum of 26% to a minimum 1.7%.

지적장애아동은 낮은 지적능력으로 인해 주의집중력의 지속시간이 짧으며 정상적인 언어습득과 발달이 어렵다. 그러므로 사회성이 떨어지고 사람과의 유대감을 형성하는 것이 어려울 수 있다. 지적장애아동의 특성을 효과적으로 개선하는 방법에는 동물을 통한 매개 활동이 있다. 동물은 아동과의 상호작용을 통하여 언어능력을 향상 시키고, 인지발달을 촉진시킨다. 그리고 의사소통이나 상호작용이 미숙한 아동에게 동물매개활동은 의사소통 및 자기표현 기술을 습득하는 데 유용하게 작용할 수 있다. 본 연구는 동물매개활동 프로그 램이 지적장애아동의 주의집중력과 언어능력에 미치는 효과를 알아보기 위해 J도 I시 특수 장애 학교에 다니고 있는 만 14세에서 16세인 지적장애아동 3명을 대상자로 선정하였다. 연구는 주 1회, 8주간, 총 16회기 동안 진행하였다. 사전ㆍ사후 검사 도구로는 Harris & Harris(1984)의 집중력 격자판 검사와 수용·표현 어휘력 검사(Receptive and Expressive Vocabulary Test: REVT)를 이용하여 연구 대상자들의 주의집중력과 수용·표현 어휘력의 비교분석을 하였다. 이 연구를 통해 동물매개활동 프로그램이 지적장애아동의 주의집중력과 수용·표현 어휘력을 유의미한 수준으로 향상시켜 주었음을 관찰할 수 있었다.

본 연구는 초등학생이 동물과의 관계를 맺고 칭찬을 하면서 칭찬요법을 적용한 동물매개활동이 초등학생 고학년의 자아존중감과 행복감에 미치는 영향을 알아보는데 목적이 있다. 본 연구의 대상자는 J도 I시 I초등학교에 재학 중인 초등학생 중 동물매개활동에 참여의사를 밝힌 11명의 학생들로 선정하여 진행하였다. 연구방법은 실험집단과 통제집단 사전·사후 표준편차 비교로 진행하였고, 동물매개활동은 2019년 4월 10일부터 2019년 5월 15일까지 주 2회씩, 총 10회기 실시하였다. 연구결과 칭찬요법을 적용한 동물매개활 동이 초등학생 고학년의 자아존중감과 행복감의 향상에 효과가 있었고 실시한 실험집단 과 대조집단의 자아존중감 척도와 행복감 척도 사전·사후 검사 결과 비교를 통해 유의한 차이가 있었다. 따라서 본 연구는 칭찬요법을 적용한 동물매개활동이 초등학생 고학년의 자아존중감과 행복감의 향상에 긍정적인 효과가 있음을 알 수 있다.

PURPOSES: The objective of this study is to evaluate the properties of high-performance concrete and compare them with the properties of ternary blended cement (OPC 60% : BFS 30% : FA 10%) as applied to all-in-one bridge decks. High-performance concrete modified with styrene-butadiene latex (SB latex) was evaluated for strength development and durability through its compressive strength and chloride ion diffusion coefficient. METHODS: The compressive strength test was conducted according to KS F 2405, and the average value of the three specimens was used as the result at each stage. The chloride ion diffusion test was performed at 28 days, 56 days, and 365 days according to NT BUILLD 492. The chloride ion penetration test was conducted according to ASTM C 1202. RESULTS: For the compressive strength of the high-performance concrete, the blast furnace slag 40% replacement (BFS40) mixture had the most similar results to those of the ternary blended cement. The BFS40 mixture exhibited a lower compressive strength at 3 days than the latex modified concrete (LMC) mixture used for the bridge deck pavement, whereas it exhibited a 3.7-9.8% higher compressive strength at 7 days. In addition, the BFS40 mixture had the lowest diffusion coefficient, which was 49.1~59.0% lower than that of the LMC mixture. Mixing with latex tended to decrease in charge passed compared to Plain which is only used ternary blended cement, and showed excellent watertighness (rated “very low”), which is lower than 1,000 coulombs in all mixtures with latex. CONCLUSIONS : The BFS40 mixture exhibited excellent compressive strength, chloride ion permeability resistance, and the lowest chloride ion diffusion coefficient although it included a small amount of latex, which makes it more expensive than the current LMC mixture. It is believed that it is possible to secure excellent economic efficiency and durability by using lesser latex than that in the LMC mixture and using a mixture of the blast furnace slag instead.