• 한국방재학회 논문집
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• 제2권2호
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• pp.61-72
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• 2002

본 연구에서는 마샬 배합설계법을 이용하여 섬유와 아스팔트 바인더의 적정한 양을 결정한 후 마샬 공시체를 제작하였다. 제작된 공시체를 이용하여 3단계의 온도(5, 20, 60$^{\circ}C$)하에서 간접인장강도 시험을 수행한 후 물성을 측정하여 기존의 아스팔트 혼합물(밀입도 20)과 섬유보강 아스팔트 혼합물 사이의 기계적 특성을 비교 분석하였다. 특히 혼합물의 소성 변형에 대한 저항성을 평가하기 위하여 휠트랙킹 시험을 실시하였다. 시험결과 전체적으로 재래식 밀입도 20 아스팔트 혼합물보다 섬유보강 아스팔트 혼합물의 간접인장강도가 높은 것으로 나타났으며, 특히 인성 (Toughness)값은 시험온도에 따라 $1.27{\sim}1.97$배 높게 나타났다. 또한 본 연구에서 수행되어진 $60^{\circ}C$에서 휠트랙킹 시험과 잔류 간접인장강도 시험에 대한 특성은 하절기의 고온 다습한 기후하에서 재래식 밀입도 20 혼합물보다 섬유보강 아스팔트 혼합물의 소성변형에 대한 저항성이 우수할 것으로 판단된다.

• 한국농공학회지
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• 제20권1호
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• pp.4599-4613
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• 1978

This study was intended to investigate the effects of bituminous material content of soil-cement mixtures on their durability. For the purpose, unconfined compressive strength test, Freeze-thaw test, and wet-dry test were performed with three types of soil. Each type of soil was mixed with three levels of cement content and each soil-cement mixture was mixed with four levels of bituminous material content. For the unconfined compressive strength test, Freeze-thaw test and wet-dry test, 324, 108, and 108-specimens were prepared respectively. Unconfined compressive strength was measured at age of 7-days, 14-days and 28-days using 108-specimens in each age. The soil-cement loss rate due to freeze-thaw and wet-dry were calculated after 12 cycles of test using 108-specimens in each test. The results are summarized as follows : 1. Optimum moisture content was increased with increase of cement content, but maximum dry density was changed irregulary with increase of the cement content. 2. The unconfined compressive strength was increased with increase of cement content, bituminous material content and curing age. Cement is more effective factor than bituminous material on unconfined compressive strength of soil-cement Mixture. 3. It is estimated as the most economical cement content that the recommended cement content of A.S.T.M. because increasing rate of unconfined compressive strength at age of 28-days was low when cement content is above the recommanded cement content of A.S.T.M. among all types of soil. 4. Although a portion of cement content is substituted for bituminous material, the necessary unconfined compressive strength can be obtained. 5. The soil-cement loss was more influenced by wet-dry than Freeze-thaw 6. The bituminous material is more effective on the decrease of soil-cement loss than increase of unconfined compressive strength 7. The void ratio of soil-cement mixture was changet irregularly with increase of cement content, but that was decreased in proportion to the increase of bituminous material content. 8. The regression equation between the unconfined compressive strength and soil-cement loss rate were obtained as table 7.

• 한국환경과학회지
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• 제27권9호
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• pp.737-742
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• 2018

Livestock manure treatments have become a more serious problem because massive environmental pollutions such as green and red tides caused by non-point pollution sources from livestock manures have emerged as a serious social issue. In addition, more food wastes are being produced due to population growth and increased income level. Since the London Convention has banned the ocean dumping of wastes, some other waste treatment methods for land disposal had to be developed and applied. At the same time, researches have been conducted to develop alternative energy sources from various types of wastes. As a result, anaerobic digestion as a waste treatment method has become an attractive solution. In this study has three objectives: first, to identify the physical properties of the mixture of livestock wastewater and food waste when combining food waste treatment with the conventional livestock manure treatment based on anaerobic mesophilic digestion; second, to find the ideal ratio of waste mixture that could maximize the collection efficiency of methane ($CH_4$) from the anaerobic digestion process; and third, to promote $CH_4$ production by comparing the biodegradability. As a result of comparing the reactors R1, R2, and R3, each containing a mixture of food waste and livestock manure at the ratio of 5:5, 7:3, and 3:7, respectively, R2 showed the optimum treatment efficiencies for the removal of Total Solids (TS) and Volatile Solids (VS), $CH_4$ production, and biodegradability.

• Korean Chemical Engineering Research
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• 제52권3호
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• pp.307-313
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• 2014

본 연구에서는 Isobutyl Acetate와 Isobutyl Alcohol의 공비혼합물을 압력변환증류공정(PSD; Pressure Swing Distillation Process)을 이용하여 99.9 mol% 이상의 Isobutyl Acetate를 분리하는 공정모사를 수행하였다. 압력변환증류공정은 공비혼합물의 상대휘발도와 공비조성이 압력의 변화에 따라 차이가 나는 특성을 이용한 공정이다. 액상에서는 Non-Random Two Liquid (NRTL) model을 그리고 기상에서는 Peng-Robinson equation을 이용하였다. 최적화 방법으로 환류비와 주입단 위치를 변수로 두고 총 재비기 소요 열량을 최소화시키는 목적으로 최적화를 수행하였다. 압력변환 증류공정은 두 개의 증류탑을 필요로 함에 따라 고압 증류탑과 저압 증류탑의 배열에 따른 최적화 조건 또한 비교를 수행하였다.

• 한국도로학회논문집
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• 제1권1호
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• pp.85-96
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• 1999

본 연구는 아스팔트 콘크리트 덧씌우기에서 야기되는 반사균열에 대한 저항성을 향상시키기 위하여 개질재 및 보강재를 사용하여 제조한 혼합물의 성능을 평가하기 위하여 수행하였다. 아스팔트 개질재로는 LDPE와 SBS 및 카본블랙을 이용하였고. 보강재로는 합성섬유(PF), 비닐(PV), 그리드(GG)를 이용하였다. 배합설계를 통해 얻은 최적아스팔트 함량으로 아스팔트 혼합물 슬래브를 제조하였다. 아스팔트 혼합물을 몰드에 붓기 전에 몰드 바닥에 비닐이나 그리드를 미리 깔아 보강 층으로서 만들었다. 갭(균열)이 있는 시멘트 콘크리트 위에 부착된 아스팔트 혼합물 공시체에 유압식 동적하중기를 이용하여 반복하중을 재하하였다. 반복하중에서 균열진전을 측정하여 각 처리 혼합물의 균열 지연효과를 평가하였다. 본 연구의 시험 결과로부터 특정 조합의 아스팔트 혼합물이 휨 파괴(Mode I)에 의한 반사균열 지연에 상당히 효과적인 것으로 나타났다.

• 한국수산과학회지
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• 제50권6호
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• pp.721-730
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• 2017

This study determined the optimal mixing ratio of functional materials to enhance the functionality of batter for fish cutlets. An optimal mixing ratio of the hiziki Hizikia fusiformis, fig fruit Ficus carica L. and pear Pyrus pyrifolia Niitaka extracts (HFP extract) of 3:1:1 was found. The physicochemical properties of the mixture were as follows: total phelonic contents of $1187.29{\pm}41.55mg/L$, 1,1-diphenyl-2-picryhydrazyl (DPPH) radical scavenging activity of $61.50{\pm}2.33%$, ascorbic acid content of $23.68{\pm}0.02g/100g$, ${\beta}-carotene$ content of $51{\pm}3.92{\mu}g/100g$, and sugar content of $12.7{\pm}0.1Brix^{\circ}$. A mixture of the extract, Korean herbal powder, and wheat flour was prepared as the fish cutlet batter. The fish cutlet prepared with the batter had a hardness of $166-202g/cm^2$ and Hunter's color scale values L of $31.14{\pm}2.1$ to $34.62{\pm}1.3$, a of $-4.89{\pm}0.21$ to $-2.26{\pm}0.19$ and b of $-20.65{\pm}2.65$ to $28.93{\pm}3.14$. The FRAP (ferric reducing antioxidant power) and VBN (volatile basic nitrogen) of the fish cutlets were measured to evaluate functionality and determine the optimal mixing ratio for cold storage at $-12^{\circ}C$, $-18^{\circ}C$, and $-24^{\circ}C$. The optimum mixture ratio of extracts /Korean herbal powder/ wheat flour was 1:6:3.

• 펄프종이기술
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• 제33권4호
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• pp.15-20
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• 2001

The function of the moisture-proof paper is to prevent moisture from adsorbing into the packed goods. Water-vapor transmission rate of the moisture-proof paper should be less than 100g/$m^2$.24hr and the optimum rate would be less than 50g/$m^2$.24hr. In general the moisture-proof paper has been made by laminating polyethylene or polypropylene on top of the base paper. However this kind of moisture-proof paper has a problem in recycling so that it brings about environmental pollution. In general the moisture-proof paper has been made by laminating polyethylene or polypropylene on top of the base paper. However this kind of moisture-proof paper has a problem in recycling so that it brings about environmental pollution. The purpose of this paper was to make moisture-proof paper using the mixture of SB latex and wax emulsion which was recyclable and environmentally friendly. Water vapor transmission rate showed less than 50g/$m^2$.24hr in mixture ratio of 85:15, 87:13, 90:10. Especially the mixture ratio of 87:13 showed the most favorable water-vapor transmission rate. However, the moisture-proof layer was destroyed slightly by folding in packing. It has been observed that there was no close relationship between water-vapor transmission rate of the moisture-proof paper and grammage of the base paper, but the density of base paper had influenced on water vapor transmission rate. It was also observed that the moisture-proof paper could be recycled. The moisture-proof paper was similar to base paper in degree of the pulping, and there was no significant difference in dispersion between moisture-proof paper and base paper. Most of wax particles which caused the spots during drying process could be removed by flotation process. Tensile strength and tear strength of both moisture-proof paper and base paper after pulping were measured to examine the fiber bonding, and no significant difference in physical properties was observed.

• 원예과학기술지
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• 제18권6호
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• pp.819-822
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• 2000

장미의 양액재배 및 상자재배시 필수적인 우량 삽목묘의 육성을 위하여 장미의 삽목발근에 미치는 삽목용토의 영향을 실험한 결과, 품종에 따라 다소간의 차이는 있었지만 피트모스와 대립 버미큘라이트 1:2의 혼합용토에서 발근이 가장 양호한 경향을 보여 대부분의 품종에서 100%의 발근율을 보였으며 'Little Mable'과 'Suplesse'도 95% 이상의 발근율을 보였다. 또한 뿌리의 생육상태를 조사한 결과, 뿌리의 수, 무게 및 직경 등도 피트모스와 대립 버미큘라이트 1:2혼합토에서 생육이 가장 양호한 경향을 보였으나 뿌리의 길이는 피트모스와 대립 펄라이트 1:2 혼합토에서 가장 긴 경향을 보였다.

• KSBB Journal
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• 제17권6호
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• pp.549-554
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• 2002

한지로 된 고서적의 가수분해가 Trichoderma viride로부터 분리한 endoglucanase I, exoglucanase II와 endo-exo혼합효소 (I：I, weight ratio)에 의하여 수행되었다. Endoglucanase I, exoglucanase II와 endo-exo혼합효소에 의한 가수분해 최적pH는 각각 4.5, 5.5, 5.0으로 나타났다. 이들 결과들은 지류문화재의 열화가 산성조건에서 셀룰라아제의 활성을 증가시켜 촉진될 수 있음을 보여준다. 또한 이들 효소들에 의한 분해에 있어서 최적 분해온도는 모두 5$0^{\circ}C$를 보여주었다. 고서적의 재생펄프를 이들 효소로 처리했을 때 수율(yield)과 물리적 강도(physical strength)를 살펴보면, 수율은 이들 효소의 농도 증가와 함께 감소함을 보여 주었다. 특히 endo-exo혼합효소로 처리했을 때 가장 낮은 값을 보여 주었다. 이는 endo성분과 exo성분의 협동작용(synergistic action)에 의한 것으로 생각할 수 있다. 물리적 강도는 exo II로 처리했을 경우 농도 증가에 따라 향상됨을 보여 주었으며, exoglucanase II와 endo-exo혼합효소로 처리했을 경우는 농도에 따라 감소함을 보여 주었다. 이들 결과들은 고서적의 분해(열화)가 endoclucanase에 의한 것임을 보여 준다. 즉 지류문화재의 물리적 강도를 저하시키는 주요 성분 효소는 endoglucanase이며 지류문화재의 효과적인 보존을 위해서는 endoglucanase성분의 활성을 억제시킬 필요가 있다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제9권3호
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• pp.166-170
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• 2004

Gluconobacter oxydans that produces the cellulose was isolated. In order to confirm the chemical features of cellulose, various spectrophtometeric analysis were carried out using electron microscopy, X-ray diffractogram, and CP/MAS $\^$13/C NMR. The purified cellulose was found to be identical to that of Acetobacter xylinum. For effective production of cellulose, the various carbon and nitrogen sources, mixture of calcium and magnesium ions, and biotin concentration were investigated in flask cultures. Among the various carbon sources, glucose and sucrose were found to be best for the production of cellulose, with maximum concentration of 2.41 g/L obtained when a mixture of 10 g/L of each glucose and sucrose were used. With regard to the nitrogen sources, when 20 g/L of yeast extract was used, the maximum concentration of bacterial cellulose was reached. The concentration of cellulose was increased with mixture of 2 mM of each Ca$\^$2+/ and Mg$\^$2+/. The optimum biotin concentration for the production of cellulose was in the range of 15 to 20mg/L. At higher biotin concentration (25-35mg/L). the bacterial cellulose production was lower.