전분과 구연산 사이의 다중 에스테르화반응에 의한 starch citrate의 저항전분 함량에 대한 반응압출성형조건들의 영향을 조사하였으며, 이들의 페이스팅 점도 특성을 조사하여 산업적 활용도가 높은 starch citrate를 제조할 수 있는 반응조건을 탐색하였다. 반응압출성형에 의한 starch citrate를 제조하기 위해 성형노즐을 제거한 쌍축압출성형기를 사용하여 반응온도, 스크류 회전속도, 반응혼합물의 쌍축압출성형기 통과횟수를 변수로 하였다. 반응온도가 높아지면서, 스크류 회전속도가 느려지면서, 쌍축압출성형기 통과횟수가 증가하면서 starch citrate의 저항전분 함량은 증가하는 경향을 나타내었다. 40% 구연산 농도의 반응혼합물을 150oC와 스크류 회전속도 10 rpm의 쌍축압출성형기를 5회 통과시킬 때 90%의 저항전분을 보유한 starch citrate를 얻을 수 있었다. 또한 40% 구연산 농도의 반응혼합물을 150oC와 스크류 회전속도 50 rpm의 쌍축압출성형기를 5회 통과시킬 때 58%의 저항전분을 보유한 starch citrate를 얻을 수 있었으며, 이는 유의적인 페이스팅 점도를 발달시켜 높은 저항전분 함량에도 불구하고 가공적성이 우수한 starch citrate를 얻을 수 있었다. 또한 starch citrate의 제조 시 전통적으로 사용되는 컨백션 오븐 보다는 쌍축압출성형기를 사용하는 것이 가공적성이 우수한 starch citrate를 제조할 수 있을 것으로 보인다. 따라서 본 연구에서 보고한 50%(s.b) 이상의 저항전분을 보유하면서도 페이스팅 점도 특성을 잃지 않은 starch citrate와 쌍축압출성형기를 활용한 starch citrate 제조기법들은 산업적 활용도 높을 것으로 예상되며 기존의 저항전분 소재들을 대체할 수 있는 잠재력이 높은 저항전분 소재일 것으로 생각된다.

PURPOSES: This study investigates the mechanical performance of carbon-capturing concrete that mainly contains blast furnace slag. METHODS: The mixture variables were considered; these included Portland cement content, which was varied from 10% to 40% of the blast furnace slag by weight. The specimens were exposed to different conditions such as high N2 and O2 concentrations, laboratory conditions and high CO2 conditions. Mechanical performances, including compressive and flexural strengths and carbon-capturing depth, were evaluated. RESULTS : The slump, air content and unit weight were not affected significantly by the variation in cement content. The strength development when the specimens were exposed to high purity air was slightly greater than that when exposed to high CO2. As the cement content increased the compressive and flexural strength increased but not considerably. The carbon-capturing capacity decreased as the cement content increased. The specimens exposed in the field for 70 days had flexural strength greater than 3 MPa. CONCLUSIONS : The results indicate that cement content is not an important parameter in the development of compressive and flexural strengths. However, the carbon-capturing depth was higher for less cement content. Even after field exposure for 70 days, neither any significant damage on the surface nor any decrease in strength was observed.

One of the main processes of tenderizing beef in Joseon Dynasty was chemical methods involving Apricot seeds, manchu cherry twig and leaves, bamboo skins, mulberry tree bark, mangsa (硭砂), salmiacum (磠砂), alcohol, fermented malt, and original honey. This study analyzed and compared the effect of broussonetia papyrifera, fermented malt, cherry trees, and mulberry tree bark from old cookbooks. Tenderizing beef with cherry trees was most effective in the experiment on shearing force, TPA, and electrophoresis of beef. According to sensory evaluation and electrophoresis test results, tenderized beef with mulberry tree bark was slightly more preferred over the method using cherry trees. However, in accordance with the above mentioned experiment, quantitative descriptive analysis showed that the most common tenderizing material was derived from morus alba powder.

본 연구에서는 저층 조적채움벽 철근콘크리트 골조 구조물의 내진보강 전과 후에 대하여 강제 진동 실험과 상시 진동 계측을 수행하였으며 시스템 식별과정을 통하여 구조물의 동특성을 구하고 해당 구조물과 유사한 동특성을 보이는 해석 모델을 만들었다. 시스템 식별 결과 댐퍼가 설치된 x방향의 감쇠비가 증가되었으며, 해석 모델과 비교한 결과 추가 설치된 부재들(전단벽과 댐퍼)의 유효 강성은 부재의 총단면 강성의 50%만이 발현되어 해당 부재들이 기존의 구조물이나 부재와 완전히 일체화되지는 않음을 알 수 있었다. 또한, 추가 설치된 기초의 y방향 구속조건을 핀으로 하여야 동특성을 일치시킬 수 있었는데, 이는 새로운 기초가 설치되며 해당 지질의 특성이 변화되었기 때문으로 보인다.

Records regarding beef cuisine and its tenderization were identified in 38 publications. Old cookbooks, agricultural texts, and Joseon’s encyclopedias addressed the subject 411 times. The beef recipe was as follows: cutting 184 times, seasoning 112 times, moist heat cooking 196 times, dry heat cooking 129 times, and drying off 33 times. Recipe also used main ingredients 194 times, sub ingredients 203 times, garnish eight times, and stock six times. Regarding seasoning and flavoring materials, there were a total of 41 types of spices, tenderizers, and others written 839 times. There are two main types of tenderizing beef: physical and chemical methods. A total of 18 types of natural tenderizers were written 57 times in the recipe.

본 연구는 실리콘 잉크의 평판 오프셋 인쇄 적성에 관한 것이다. 전자 산업에서 실리콘 잉크는 전극 형성 과정에서 주로 사용되며 고해상도의 패턴을 재현하는 것이 요구된다. 오프셋 인쇄는 스크린 인쇄보다 패턴 형성을 빠르게 할 수 있다. 그래서, 오프셋 인쇄에서 실리콘 잉크의 레오로지적 특성들은 매우 중요하다. 실리콘 잉크를 IGT 인쇄적성 시험기로 인쇄된 인쇄물의 광학 농도, 잉크 전이량, 광택도 그리고 항복가를 측정하였다. 그 결과 실리콘 잉크를 오프셋 인쇄법으로 인쇄가 가능하다는 것을 발견 하였다. 광학 농도는 신문 용지에서 PDMS 잉크가 일반 오프셋 잉크보다 높았으며 10 poise의 PDMS에서 가장 높게 측정 된다. 실리콘 잉크의 오프셋 평판 인쇄가 가능하면 좀 더 빠른 속도로 방수인쇄나 전자인쇄의 목적으로 사용할 수 있을 것으로 생각한다.

This study presents an experimental study on compressive and flexural strengths of concrete reinforced by 3D Fiber Reinforced Polymer(FRP). This study is intended to investigate the potential of 3D FRP concrete composites against impact or explosive loadings. For the comparative study, non-reinforced specimen and specimens reinforced by 3D FRP are constructed and tested. 20mm×10mm 3D fiber and 25mm×20mm 3D fiber was set to be variable.

PURPOSES: As a part of our research into repair techniques for roads that have collapsed as a result of a natural disaster, this study set out to find the optimum mix proportion for gravels to be used to restore a damaged area. METHODS: This study considered flow and strength-development characteristics. The experimental variables were the W/C ratio, the usage of the admixture, the types of cement, and the quantity of fine aggregate over three different experimental stages. The compressive strength was measured at 12 hours, one day, three days, and seven days. RESULTS : The flow varied with the amount of fine aggregate and the use of a high-range water-reducing (HRWR) admixture. The compressive strength also varied with respect to the type of cement and the W/C ratios. The strength satisfied the expected requirement of 21 MPa after one day, provided the mix proportion was appropriate. CONCLUSIONS: A gravel-filling high-flow cement-based mortar exhibited strength and consistency with a W/C ratio in the range of 0.40 to 0.45, assuming the use of HRWR at 0.5 to 0.7% and a fine aggregate/cement ratio of 1.0 to 1.5.

Cracking is an inevitable fact of asphalt concrete pavements and plays a major role in pavement deterioration. Pavement cracking is one of the main factors determining the frequency and method of repair. Cracks can be treated with a number of preventative maintenance actions, including overlay surface treatments such as slurry sealing, crack sealing, or crack filling. Pavement cracks can show up as one or all of the following types: transverse, longitudinal, fatigue, block, reflective, edge, and slippage. Crack sealing is a frequently used pavement maintenance treatment because it significantly extends the pavement service life. However, crack sealant often fails prematurely due to a loss of adhesion. Because current test methods are mostly empirical and only provide a qualitative measure of the bond strength, they cannot accurately predict the adhesive failure of the sealant. This study introduces a laboratory test aimed at assessing the bonding of hot-poured crack sealant to the walls of pavement cracks. A pneumatic adhesion tensile testing instrument (PATTI) was adopted to measure the bonding strength of the hot-poured crack sealant as a function of the curing time and temperature. Based on a limited number of test results, the hot-poured crack sealants have very different bonding performances. Therefore, this test method can be proposed as part of a newly developed performancebased standard specification for hot-poured crack sealants for use in the future. PURPOSES : The purpose of this study was to evaluate both the adhesion and failure performance of a crack sealant as a function of its curing time and curing temperature. METHODS: A pneumatic adhesion tensile testing instrument (PATTI) was adopted to measure the adhesion performance of a crack sealant as a function of the curing time and curing temperature. RESULTS: With changes in the curing time, curing temperature, and sealant type, the bond strengths were found to be significantly different. Also, higher bond strengths were measured at lower temperatures. Different sealant types produced completely different bond strengths and failure behaviors. CONCLUSIONS: The bonding strength of an evaluated crack sealant was shown to differ depending on various factors. Two sealant types, which were composed of different raw materials, were shown to perform differently. The newly proposed test offers the possibility of evaluating anddifferentiatingbetweendifferentcracksealants.Basedonalimitednumberoftestresults,this test method can be proposed as part of a newly developed performance-based standard specification for crack sealants or as part of a guideline for the selection of hot-poured crack sealant in the future.

PURPOSES : To design a pre-heater for warm in-place recycling equipment, three different heating systems were evaluated to determine their thermal efficiency. METHODS: In this study, a 30cm×30cm×15cm wheel-tracking specimen was used to measure the inner temperature as a function of the heating system. The inner temperature of the specimen was measured with a data logger at the surface, and at depths of 1cm, 2cm, 3cm, 4cm, and 5cm. To evaluate the thermal efficiency, the researchers used three different types of equipment, namely, IR, a heating wire, and a gas burner. RESULTS: The IR heating system exhibits a higher level of performance than the others to achieve the target temperature at a depth of 5cm in the specimen. The gas burner system was capable of heating the surface to a temperature of up to 600℃. The other types, however, cannot heat the surface up to 600. The thermal efficiencies were measured based on the laboratory conditions. CONCLUSIONS: To find the most effective system for application to the development of a pre-heater for warm in-place recycling, various systems (IR, heating wire, gas burner) were examined in the laboratory. As a result, it was found that the hot plate of a gas burner system provides the highest temperature at the surface of the asphalt but, of all the systems, the IR system provides the best internal temperature increase rate. Furthermore, a gas burner can age the asphalt binder of the surface layer as a result of the high temperature. However, the gas burner cannot attain the target temperature at 5cm. The IR system, on the other hand, is effective at increasing the internal temperature of asphalt.