PURPOSES : The aim of this study is to investigate the enhancement of performance and the mix design method for asphalt mixtures utilizing ferronickel slag, an industrial by-product METHODS : To enhance the performance of FNS asphalt, waste tire powder (CR) was incorporated, and the characteristics of FNS asphalt aggregate, along with the impact of CR, were evaluated through the mix design process. RESULTS : CR is found to be suitable with a size of 30 mesh, and the optimal usage amount is determined to be 1±0.1% of the mixture weight, considering dense grade asphalt mixture. Volumetric design considering the swelling characteristics of CR is necessary, and a mixing design with a consistent tendency can be achieved only when an appropriate VMA is secured. CONCLUSIONS : The mix design for FNS-R asphalt mixture requires an increase of approximately 1% in VMA compared to conventional dense-graded asphalt mixtures to accommodate the swelling of CR. Additionally, FNS-R asphalt exhibits improved resistance to rutting comparable to modified asphalt and meets quality standards, including stripping resistance.

In this study, when manufacturing Yakgwa, 0, 25, or 50% of embryonic rice flour (ERF) was substituted for wheat flour (WF) to make the dough. After making Yakgwa by hot air frying (HF) or deep-fat frying (DF) methods, physicochemical characterization and acceptance tests were conducted. ERF had a higher water-binding capacity and a lower fat-binding capacity than WF (p<0.05). Yakgwa prepared by HF had lower crude fat contents, peroxide values, and expansion rates, but higher hardnesses, lightnesses, and rednesses (p<0.05) than that prepared by DF. Higher ERF substitution ratios reduced acid values and expansion rates and increased hardness (p<0.05). Acceptance testing showed 0% ERF Yakgwa prepared by HF had a significantly higher acceptance than Yakgwa prepared by DF. HF was found to have a positive effect on product acceptability. Yakgwa prepared with the DF method by substituting WF with ERF resulted in better flavor and overall acceptability than Yakgwa prepared with WF alone (p<0.05).

PURPOSES : In general, a high-performance concrete construction method is a method of loading mixed cement and other materials on a mobile mixer equipped with a concrete plant. However, the construction cost is high because the unit cost of the mixed cement is very high and the equipment usage fee of the mobile mixer is also high. To compensate for these drawbacks, a cellular spray concrete method was developed. This is a highly functional customized concrete construction method in which admixtures are added to high-flow concrete with cellular (air bubbles) added at the site and constructed through spraying. METHODS : Field workability evaluation using cellular concrete was carried out using a spray method in 2017 and an anti-foaming agent in 2018. The test construction section was set as a new road-pavement construction site. After construction, strength, durability characteristics, and void analysis were performed to compare the construction methods. The results of laboratory tests under optimal conditions were also compared to the on-field results. By comparing the indoor mixing and the on-field results, we analyzed whether there were any problems concerning the performance expression. The economic feasibility at the initial construction stage was analyzed by comparing the existing and the cellular concrete construction methods in terms of material cost and equipment usage fee. RESULTS : In the case of cellular spray concrete, construction through spraying is cumbersome, and the need to additionally use large equipment such as a pump car and compressor constitutes a disadvantage. However, the most relevant feature is that it can be constructed not only on the floor, but also on a slope. In the case of cellular concrete with an antifoaming agent, it was possible to quickly produce high-performance concrete using on-site remixing equipment. By supplying materials to the pouring surface using a conveyor, smooth construction and construction in narrow spaces were also possible. CONCLUSIONS : The cellular concrete method allows the immediate on-site production of high-performance concrete, and it is possible to selectively apply spray construction, antifoaming agent construction, etc.

This study was carried out to investigate the effect of the feeding method of total mixed fermentation (TMF) and concentrate feed on the growth performance, carcass and meat characteristics of late fattening Hanwoo steers. Twenty-four Hanwoo steers were used in this study. The control group was fed with concentrate feed + rice straw from the growing to the late fattening period, while the T1 group was fed with TMF from the growing to the early fattening period and concentrate feed + rice straw for the late fattening period. The T2 group was fed with TMF from the growing to the late fattening period. The average daily gain (ADG) and feed conversion ratio (FCR) were not different between the treatment and control group. Serum cholesterol and high density lipoprotein (HDL) cholesterol concentrations were higher in the T2 groups than in the control group (p<0.05). The yield grade and quality grade were not different between the treatment and control group. The lightness of longissimus muscle was higher in the T1 group than in the control and T2 groups (p<0.05). Poly-unsaturated fatty acid (PUFA) of longissimus muscle was increased in the T2 groups than in the control group. Therefore, the method of feeding TMF and concentrate feed could have a positive effect on the lightness and fatty acid composition of longissimus muscle without affecting the growth and carcass grades of Hanwoo steers.

PURPOSES: This paper presents a mix design method for using steel slag as an aggregate for asphalt mixtures. METHODS: Steel slag has a different density and absorption rate than natural aggregates. The asphalt content was calculated according to the steel slag characteristics, and the formula for aggregate-gradation correction was presented. RESULTS: The asphalt mix was designed using the proposed equations. Using the proposed mix design method, it was possible to design the asphalt mixture according to the target-usage amount of the recycled aggregate. CONCLUSIONS: The suggested method can be used for asphalt mix design using aggregates with different densities and absorption rates. It is expected to contribute to quality improvement by ensuring accurate calculation of mixing ratios for steel slag asphalt mixtures.

본 연구에서는 재생골재를 사용한 콘크리트의 고질적 문제점인 강도, 특성, 내구성의 저하를 재생골재 배합의 수정을 통해 개선하고자 한다. 수정된 배합의 모식도는 아래의 그림 1과 같다.

마샬배합설계에서 얻어지는 안정도나 흐름은 혼합물의 역학적 특성을 제대로 반영하지 못하며 소성변형과의 상관성이 낮다. 그러므로 안정도나 흐름의 기준을 통과하는 배합으로 제조한 혼합물에서도 소성변형이 많이 발생된다. 따라서 본 연구의 목적은 국내에서 이용되는 마샬 방법과 미국의 수퍼페이브 방법으로 배합설계를 수행하여 각 방법의 혼합물 특성치의 차이점과 문제점을 확인하는데 있다. 이를 위하여 골재 세 종류, 한 종류의 아스팔트(AC 60-80), 두 종류의 골재 입도(19mm, 13mm)를 각각의 배합설계방법에 사용하여 총 12종류의 혼합물을 배합설계를 수행하여 최적아스팔트함량을 결정하였다. 이 결정된 최적아스팔트 함량으로 혼합물을 제조하여 특성치를 비교 분석하였다. 그 결과, 마샬 방법을 통해 결정된 아스팔트 함량이 수퍼페이브 방법에 의 한 함량보다 0.1~0.3% 포인트 정도 높게 나타났다. 이것은 마샬 방법이 수퍼페이브 방법보다 아스팔트 함량을 높게 결정되도록 골재입도가 주어졌기 때문인데 이것이 소성변형에 상대적으로 취약한 직접적인 원인이 되는지는 더 많은 연구가 필요할 것이다.

국내의 각종 시방서 및 지침에 수록되어 있는 기존 마샬 배합설계 방법은 일본 도로공단의 규격을 도입하여 사용한 것이다. 이러한 배합설계 방법은 최근의 도로 포장의 공용성에 많은 문제점을 야기시키는 원인 중의 하나로 인식되어지고 있다 따라서 현재 외국의 배합설계 과정에서 가장 많이 이용되고 있는 용적 개념의 도입을 통해 개선된 마샬 배합설계 방법을 제시하고자 한다. 본 연구를 통해 개선된 배합설계 방법은 공극률 4%에 해당하는 아스팔트 함량을 예비 최적 아스팔트 함량으로 결정한 후 포화도, VMA(골재 간극률), 안정도, 흐름값의 마샬 물성치를 만족하면 이를 최적 아스팔트 함량으로 정하는 방법이다. 이러한 배합설계 방법은 기존 방법에서는 고려하지 않는 VMA 값을 도입하였으며, 현장에서 오차가 많이 발생되는 마샬 안정도 시험을 설계 요소가 아닌 검토 요소로 정함으로써 배합설계의 오류를 줄이는 방법이다. 실내 실험을 통한 기존 방법과 개선 방법의 비교 결과. 공극률을 제외한 최적 아스팔트 함량, 밀도, 안정도, 그리고 흐름값의 마샬 물성치에서는 비슷한 결과값을 나타내었다. 이는 개선 방법을 적용할 때 다른 마샬 물성치들은 큰 변동이 없이 일정한 공극률을 가지는 혼합물 생산이 가능하다는 것을 나타낸다. 따라서 개선된 마샬 배합설계 방법은 현장에서 일정한 공극률(4%)을 가지는 혼합물의 생산을 가능하게 하고, 이는 아스팔트 혼합물의 품질 향상에 큰 도움을 줄 것으로 생각된다.

Bechamel sauce의 배합비율과 방법을 달리하여 소스를 만들었을 때의 최적 조건은 다음과 같다. 1. 우유의 양과 조리 방법을 달리한 Bachamel sauce의 점도와 퍼짐성은 각각의 시료간에 유의적인 차이를 나타내었으며 (P<0.001), 점도는 우유에 첨가되는 루의 양이 적음에 따라 증가하며, 반대로 퍼짐성은 감소함을 알 수 있었다. 2. 양파 첨가 방법을 달리한 Bechamel sauce의 점도와 퍼짐성은 각각의 시료간에 서로 유의적인 차이를 나타내지 않았다(P<0.05). 3. 우유의 양과 조리 방법을 달리한 Bechamel sauce의 관능적 평가는 각각의 시료간에 유의적인 차이를 나타내었다(P<0.001). 색, 부드럽기, 전체적인 맛 등에서 높은 기호도를 나타낸 것은 버터와 밀가루 그리고 우유가 1 : 1 : 17인 것이었다. 4. 양파 첨가 방법을 달리한 Bechamel sauce의 관능적 평가에서는 점도, 부드럽기, 풍미, 전체적인 맛에서 각각의 시료간에 유의적인 차이를 나타내었으며(P<0.001), 버터에 양파를 볶아서 만드는 방법이 가장 기호도가 높았다.

약과의 튀김 온도와 반죽 횟수가 약과의 품질 특성에 미치는 영향과 혼합 계획(mixture experiment)에 따라 3가지 성된(참기름, 시럽, 소주)의 수준을 변경하여 재료 배합비가 약과의 품질 특성에 미치는 영향을 조사하였다. 튀김 온도와 반죽 횟수에 따른 영향은 색도에서 L(명도)값은 120℃에서 유의적으로 높았으며, 반죽 횟수가 많을 때 증가하였다. a(적색도)값은 온도가 높을 때 증가하였으나 반죽 횟수의 영향은 별로 없었다. b(황색도)값은 유의차가 없었다. 경도는 온도가 높을수록 유의적으로 커졌으며 반죽 횟수가 많을 때 경도가 약간 커졌다. 지방 흡수율은 온도가 높아짐에 따라 유의적으로 감소하였고, 반죽 횟수가 많을 때 약간 감소하였다. 집청 흡수율은 온도가 낮을수록 유의적으로 증가하였으며, 반죽 횟수에 따른 차이는 없었다. 재료 배합 비율에 따른 영향은 색도는 재료 배합 비율과의 사이에 뚜렷한 관계를 나타내지 않았으며, 경도는 참기름, 소주의 양이 많아지면 단단해지고 시럽이 많아지면 연해졌다. 지방 흡수율은 참기름, 시럽의 함량이 증가할 때 증가하였으며, 집청흡수율은 참기름과 소주의 함량이 감소하고, 시럽의 함량이 증가할 때 증가하였다.

A literature on Korean rice cakes by ingredients and preparation methods was reviewed with published literatures in Korea from 1950 to 1995. The result were as followed; 1. The 46 volumes about preparation of Korean rice cakes were reported. There were 32 steamed (Jeung-byung), 6 pounded (Do-byung), 4 fried (Yu-jeon-byung), and 4 boiled Korean rice cakes (Kyung-Dan). This result showed that steamed Korean rice cake was the most frequently studied among any other kinds of Korean rice cakes. 2. The reports on preparation of Korean rice cakes were rare during 1950's~ 1960's. In 1970's, there were few papers about basic study for Korean rice cakes. And it was reached 8 volumes of steamed, each 1 volume of fried or boiled Korean rice cakes. From 1990's, the more scientific researches were progressed vigorously so reached 11 volumes till 1995 but it was limited to Solgi and Jeungpyun etc. This result shows that the experiment for Korean rice cake was not various. 3. The preceded studies for Korean rice cake were investigated to see texture, sensory, quality characteristic and effect of substitutes added to original ingredients.