본 연구에서는 저온 소성 굴 패각의 재활용을 위한 기초적 연구로서 메조코즘 실험을 통해 저온 소성 굴 패각의 피복에 따른 연안 오염 퇴적물의 성상 변화를 조사하였다. 이를 위해 350 °C에서 소성시킨 굴 패각을 연안 오염 퇴적물에 피복하여 직상수와 간극수의 성상변화를 분석하는 메조코즘 실험을 수행하였다. 실험 결과, 굴 패각의 피복에 의해 수층과 퇴적층이 분리되었기 때문에 직상수의 산화 환원전위(ORP) 증가 및 DIN 중의 NH3-N의 비율의 감소가 실험구에서 관측되었다. 실험구의 DIP의 농도는 대조구와 비교하여 유의한 차이를 확인하기 어려웠다. 굴 패각의 피복에 의한 퇴적물의 총유기탄소(TOC)는 감소하였으며, 산휘발성황화물(AVS)은 저온 소성 굴 패각의 황화물 흡착 능력으로 인해 최대 50%까지 감소한 것으로 확인되었다. 본 연구의 결과로부터 저온 소성 굴 패각은 연안 오염 퇴적물의 정화를 위해 이용될 수 있는 재료인 것으로 결론 지을 수 있다.

In aluminum brazing processes, corrosive flux, which is used in preventing oxidation, is currently raising environmental concerns because it generates many pollutants such as dioxin. The brazing process involving noncorrosive flux is known to encounter difficulties because the melting temperature of the flux is similar to that of the base material. In this study, a new brazing filler material is developed based on aluminum and non-corrosive flux composite powder. To minimize the interference of consolidation aluminum alloy powder by the flux, the flux is intentionally embedded in the aluminum alloy powder using a mechanical milling process. This study demonstrates that the morphology of the composite powder can be varied according to the mixing process, and this significantly affects the relative density and mechanical properties of the final filler samples.

PURPOSES: Using recyclable materials in asphalt pavement industry is one of the essential tasks not only for saving construction budgets but also for mitigating environmental pollutions. Over the past decades, several efforts have been made by road maintenance agencies to incorporate various recyclable materials into virgin asphalt paving mixtures. As a result, reclaimed asphalt pavement (RAP), which consists of old pavement material was selected as one of most widely used recyclable materials. In this paper, the effects of using different amounts of single-recycled RAP (SRRAP) and double-recycled RAP (DRRAP) on the low-temperature characteristics of asphalt mixtures were investigated. METHODS: To evaluate the low-temperature characteristics of SRRAP and DRRAP mixtures, two experiments, the bending beam mixture creep test and semicircular bending fracture test were performed. The experimental parameters: creep stiffness, m-value, thermal stress, critical cracking temperature, fracture energy, and fracture toughness were computed then compared. RESULTS : RAP mixtures (SRRAP or DRRAP) showed lower mechanical performance compared with conventional asphalt mixtures. The differences became distinct with increased RAP addition. However, the performance differences between SRRAP and DRRAP mixtures were not significant in all cases, which indicate the possible application of re-recycling technology (DRRAP) in the asphalt pavement industry. CONCLUSIONS : The addition of RAP to virgin asphalt can mitigate low-temperature performance despite the improvement in fracture performance observed in some cases. Therefore, using RAP (SRRAP or DRRAP) mixtures on inter or sublayer construction, but not on the surface layer, is recommended. Moreover, the possibility of applying double-recycling technology in asphalt pavement industry can be introduced in this study because not significant performance differences were found between SRRAP and DRRAP mixtures especially at low temperature.

PURPOSES: Using recycled asphalt materials (called Reclaimed Asphalt Pavement: RAP) from existing asphalt pavement layers in newly constructed asphalt pavement is an essential option not only for lowering the construction budget but also for mitigating environmental pollution for society. For this reason, many pavement agencies in South Korea, the USA, and Canada have observed the effect of RAP on conventional asphalt pavement to evaluate and set proper material specifications and addable amounts. In this paper, effect of recyclable material on low-temperature performance of asphalt materials was investigated with two different mechanical tests. Among the recyclable material sources, RAP and Taconite Aggregate (TA), which is mainly produced in northern Minnesota (USA), were considered. METHODS : To evaluate the low-temperature mechanical performance of a RAP mixture, two different experimental tests (In-Direct Tensile (IDT) low temperature creep test and Semi-Circular Bending (SCB) test) were considered. The mechanical parameters creep-stiffness, relaxation modulus, fracture energy, and fracture toughness were computed then compared. RESULTS: More brittle characteristics were observed with RAP-added asphalt mixtures compared to the conventional asphalt mixtures, as expected. However, the differences of computed mechanical performances were not significantly distinct for RAP mixtures compared to conventional mixtures when the RAP proportion was around 20%, and with the addition of TA up to 20%. CONCLUSIONS : It can be concluded that up to 20% of RAP addition (along with TA up to 20%) in a virgin asphalt mixture does not provide significant performance reduction. This addable proportion can be viewed as a successful minimum level when considering the addition of RAP to hot-mix asphalt (HMA). Moreover, applying TA with RAP could offer a successful alternative for asphalt recycling and the materials industry.

외래해충은 자연생태계 교란과 농업환경의 파괴를 가져와 궁극적으로 우리 사회에 엄청난 사회적 비용과 경제적 손실을 유발한다. 이러한 외래해충의 국내 정착 시 대상 해충에 대한 효과적인 방제법과 천적 등의 부재로 박멸에 어려움이 있기에 검역의 역할은 매우 중요하다. 최근 붉은불개미와 금지급 과실파리류는 변화하는 기후와 국가 간교역량의 증가에 따라 최근 국내에서 발견되고 있다. 이를 위해 근연관계에 있는 일본열마디개미와 호박꽃과실파리를 대상으로 내한성을 조사하였다. 그 결과 두 종의 곤충은 저온처리(8℃에서 2시간) 후 체내빙결점의 저하가 나타났다. 또한 저온처리 후 –5℃에서 생존율은 호박꽃과실파리가 일본열마디개미 보다 높은 것으로 조사되었다.

스탠다드국화 신품종을 육성하기 위하여 충남농업기술원 화훼연구소에서 2009년에 황색의 모본 ‘Summer Yellow’와 부본 ‘ST07-09-02’계통을 인공 교배하였다. 2010년에 종자를 파종하였고, 이중 내병성이 강하고 기호성이 우수한 개체를 선발하여 ‘ST10-047-01’로 계통명을 부여하였다. 2011년부터 2013년까지 주년 생산성을 위해 촉성 및 자연, 억제재배 특성을 각각 검정하였으며, 2013년 ‘Geumhwa’로 명명하고 품종등록 출원하였다. ‘Geumhwa’의 생육 및 개화특성은 국내에서 많이 재배되고 있는 황색 스탠다드국화인 ‘Summer Yellow’를 대조 품종으로 하여 조사하였다. ‘Geumhwa’ 품종은 자연개화기가 10월 6일로 ‘Summer Yellow’의 10월 25일에 비해 빨랐다. ‘Geumhwa’는 초장이 86.3cm로 ‘Summer Yellow’의 93.8cm보다 작았고, 곁가지 제거수는 8.1개로 ‘Summer Yellow’의 16.6개보다 적었다. ‘Geumhwa’의 꽃직경은 13.6cm로 ‘Summer Yellow’의 13.5cm와 비슷하였으며, 꽃잎수는 ‘Geumhwa’가 263.6개로 ‘Summer Yellow’의 295.3개보다 적었다. 재배상 유의사항은 ‘Geumhwa’는 중간종이므로 초기생육이 왕성하도록 비배 관리를 하고 생육기간 중 지베렐린 1,000mg･L-1를 2회 처리하여 신장력을 높이도록 한다. 또한 설상화수가 적은 편이므로 재전조를 실시하여 설상화수를 늘린다면 황색의 연중 조기개화가 가능한 고품질 신품종 스탠다드 절화국화로써 소비자 기호 충족 및 농가소득 창출에 기여할 수 있을 것으로 기대된다.

This study examined the effects of low temperature conditions on the expansion of choux when mixing the dough with egg fluid. The egg fluid was tested at 5 and 17oC, and the dough temperature was 20, 30, 40, 50, 60 or 70oC. The expansion decreased with decreasing temperature of the egg fluid and dough, with the concomitant formation of membranes in the cavities of choux because of the poor emulsion stability of the choux paste. In addition, the structure of the choux pastry was not dense and the cracks in the surface were partial and narrow. The shape, expansion and cracks of choux were the best at a dough temperature of 60 and 70oC added with egg fluid at 17oC. The temperature of the choux paste in these two samples was higher than the melting point of the butter used to produce the paste. Therefore, the practical limit temperature when mixing the egg fluid and dough is 20 and 60oC, respectively, and care should ve taken to maintain a low temperature when making choux in confectionary.

In this study, a relatively effective process is used to sterilize Escherichia coli on the surface of micro-sized calcium citrate powder using nitrogen and argon as process gases in a low-temperature vacuum plasma treatment. The purpose of this study is to confirm and to introduce the effectiveness of homogeneous surface treatment for the sterilization of fine inorganic powder by the rotatable low-temperature RF plasma system designed by ourselves. The results of the test using 3M petrifilm showed that there were no remarkable spots in the case of the surface of plasma treated powder, whereas the untreated powder showed many blue spots, which indicating that the E. coli was alive. After 5 days, in the same samples, the blue spots were seen to be larger and darker than before, while the plasma-treated powder showed no changes. The results from FE-SEM analysis showed that the E. coli was damaged and/or destroyed by reactive species generated in the plasma space, resulting in the E. coli being sterilized. Furthermore, the sterilization effects according to the selected parameters (N2 and Ar; flow rate 30 and 50 sccm) adapted in this study were mutually similar, regardless of such different process parameters, and this indicates that homogeneous treatment of powder surfaces could be more effective than conventional methods. Therefore, the plasma apparatus used in this study may be a practical method to use in a powerful sterilization process in powder-type food.

Mediterranean fruit fly, Ceratitis capitata, is one of the most important quarantine pest worldwide. Fruit flies cause serious damage on orchard, and also can cause quarantine problem to fruit exportation. Recently, because of global warming, there is threats of fruit fly invasion to Korea, especially to Jeju island. So there should be a anticipative research about fruit fly control. Many physical quarantine treatment methods, like heat treatment and low-temperature treatment, are developed to control quarantine pests. Recent researches indicate that low-temperature treatment shows good efficacy on several quarantine pests without phytotoxicity. In this trial, we’ve applied the low-temperature treatment on citrus at laboratory and pilot scale containers to validate efficacy and phytotoxicity. Egg and larvae stage of C. capitata was completely controlled after 5 days and 8 days low-temperature treatment at 0℃ respectively, and there was no phytotoxicity on citrus. These results indicate that the low-temperature treatment can be applied to control fruit fly on citrus fruit.

본 연구에서는 투명도와 기계적 특성을 향상시키기 위해 저온 공정의 졸-겔 법을 이용하여 하이브리드 복합체의 코팅 박막을 제조하였다. 하이브리드 복합체로는 ZrO2/TiO2/organosilane을 사용하였으며, 그 중 organosilane은 3-(trimethoxysilyl)propyl methacrylate을 사용하였고 이는 저온 공정의 광경 화 반응을 위해 도입되었다. 다양한 조성비로 합성된 복합체를 폴리 카보네이트 기판 위에 저온 공정의 졸 -겔 법을 이용하여 광경화와 열처리 공정을 거처 코팅 박막을 제조하였고 이 코팅 박막의 광학 특성 및 기계적 강도를 확인하였다. 코팅 박막은 가시광선 영역에서 97.5 % 이상의 투과도를 가짐을 확인하였고 기계적 강도는 9H 이상의 연필 경도를 가진 것을 확인하였다. 특히 ZTS-2-1 코팅 박막의 나노 압입 경도는 1.14 GPa로 가장 높게 측정되었다.

In this study, pH, oBrix, salt concentration, sodium content, color, hardness, and sensory evaluations were measured during storage at low temperatures for 21 days after making tongue sole Jangajji with different types of Gochujang sauces. The pH was higher than those of samples not containing Maesil fermented liquor at all storage periods. The oBrix of the Maesil fermented liquor added samples was higher than that of the samples not added at the early stages of storage. On the other hand, there was no significant difference between the samples with and without Maesil fermented liquor at the later stages of storage. The sodium content was lower than that of the samples not containing Maesil fermented liquor. The lightness (L) was lower in the early stages of storage than those of the Maesil fermented liquor. In the late stage of storage, however, the lightness was higher than those of the samples not containing Maesil fermented liquor. The redness (a) of the GRWO sample group showed the highest value at all storage periods compared to the other sample groups. The yellowness (b) of the GRWO sample group was high at the early stages of storage. On the 21st day of storage, however, the GRW sample group was significantly higher (p<0.01). The hardness results showed that the value of the later storage period was lower than that at the initial storage stage. The sensory evaluation showed that the Maesil fermented liquor reduced the spicy, salty, bitter, and unpleasant taste. As a result of the acceptance test, the GRWO and GRW samples were evaluated as the acceptance group with color, aroma, texture and overall acceptability compared to the brown rice Gochujang sample group.

Physiological responses and activities of antioxidative enzymes were investigated in pepper(Capsicum annuum) seedlings subjected to low temperature stress. The seedlings were exposed to 7℃, 11℃, or 15℃ for 4 h during the early seedling stage of pepper plants. The results showed that plant height and chlorophyll content were unaffected by the treatments. Polyphenol content in seedlings exposed to 7℃ was higher than that at 11℃ and 15℃ for 2 h. After 3 h of treatment, the flavonoid content was higher in pepper seedlings exposed to 7℃ than 11℃ and 15℃, which was slightly higher than that detected in the control. The H2O2 content increased remarkably with increasing exposure time to low temperature(i.e., 7℃) as compared to that at 11℃ and 15℃. The levels of antioxidant enzymes superoxide dismutase(SOD), catalase(CAT), ascorbate peroxidase(APX), and peroxidase(POD) fluctuated. These results provide basic information that can be utilized to maintain efficient temperature in greenhouses for sustainable growth of pepper under severe low temperature conditions.

The microstructural evolution and modulation of mechanical properties were investigated for a Ti65Fe35 hypereutectic alloy by addition of Bi53In47 eutectic alloys. The microstructure of these alloys changed with the additional Bi- In elements from a typical dendrite-eutectic composite to a bimodal eutectic structure with primary dendrite phases. In particular, the primary dendrite phase changed from a TiFe intermetallic compound into a β-Ti solid solution despite their higher Fe content. Compressive tests at room temperature demonstrated that the yield strength slightly decreased but the plasticity evidently increased with an increasing Bi-In content, which led to the formation of a bimodal eutectic structure (β-Ti/TiFe + β- Ti/BiIn containing phase). Furthermore, the (Ti65Fe35)95(Bi53In47)5 alloy exhibited optimized mechanical properties with high strength (1319MPa) and reasonable plasticity (14.2%). The results of this study indicate that the transition of the eutectic structure, the type of primary phases and the supersaturation in the β-Ti phase are crucial factors for controlling the mechanical properties of the ultrafine dendrite-eutectic composites.