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        검색결과 43

        1.
        2024.10 구독 인증기관·개인회원 무료
        제지 공정 과정에서 슬러지를 소각할 때 생성되는 제지애쉬를 도로 하부 동공 보수 재료인 유동성 채움재의 재료로 재 활용 가능성에 대하여 실험적으로 평가하였다. 유동성 채움재는 플로우 값으로 대표되는 유동성, 압축강도 및 블리딩률 에 의해 평가됨에 따라 해당 특성에 대하여 시험 및 평가를 진행하였다. 제지애쉬의 화학적 성분이 강도 발현을 위한 시 멘트와 유사한 점에 기반하여 제지애쉬를 시멘트 중량비의 0~40% 범위에서 치환하여 페이스트 혼합물을 제작하였다. 이 후, 플로우 및 압축강도 시험을 수행하여 제지애쉬의 적정 치환 범위를 선정하였다. 이후, 시멘트-제지애쉬 페이스트 혼 합물에 잔골재 및 굵은 골재를 혼합하여 유동성 채움재(CLSM: Controlled Low Strength Material) 혼합물을 배합하고 플로 우, 압축강도, 블리딩 시험을 실시하였다. 시험 결과 제지애쉬 치환율이 증가함에 따라 혼합물의 유동성 및 압축강도가 감소하였으며, 이는 제지애쉬의 높은 수분 흡수율에 의한 영향으로 판단된다. 혼합물의 적정 배합을 통하여 소정의 플로 우, 압축강도 및 블리딩률 기준을 만족할 수 있었으며, 이를 통해 제지애쉬의 유동성 채움재 활용 가능성을 확인하였다.
        5.
        2022.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We investigated the standard cultivation substrate for Sparassis latifolia “Neowul” bred in Jeollabuk-do Agricultural Research and Extension Services. Cultivation characteristics and yield were assessed by varying the kind of sawdust and additives, and the mixing ratio. The cultivation period in larch sawdust was the shortest at 97 days. The yield was excellent (143.6 g). The findings indicated that larch is a tree species appropriate for the cultivation of S. latifolia. When the additives were varied, the yield and productivity (53.1%) were highest (116.6 g) for the wheat bran treatment. Thus, wheat bran would be an additive appropriate for culturing S. latifolia. Concerning the use of different mixing ratios, larch sawdust:beet-pulp:wheat bran ratios of 80:15:5 and 85:10:5 resulted in yields of 114.4 g and 111.4 g, and productivity of 52.5% and 51.8%, respectively. These yield and productivity values were not statistically different. Thus, the standard cultivation substrate for S. latifolia can comprise larch sawdust, beet pulp, and wheat bran at a ratio of 80:15:5 or 85:10:5. The carbon/nitrogen (C/N) ratio assumed to be appropriate for the cultivation of S. latifolia was 184 –223. Pinheading would be difficult below a C/N substrate ratio of 105. Thus, the C/N ratio of the media, as well as the pH, would be vital factors affecting pinheading during S. latifolia cultivation.
        4,000원
        6.
        2022.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The present study was conducted to examine the effect of soybean silage as a crude protein supplement for corn silage in the diet of Hanwoo steers. The first experiment was conducted to evaluate the effect of replacing corn silage with soybean silage at different levels on rumen fermentation characteristics in vitro. Commercially-purchased corn silage was replaced with 0, 4, 8, or 12% of soybean silage. Half gram of the substrate was added to 50 mL of buffer and rumen fluid from Hanwoo cows, and then incubated at 39°C for 0, 3, 6, 12, 24, and 48 h. At 24 h, the pH of the control (corn silage only) was lower (p<0.05) than that of soybeansupplemented silages, and the pH numerically increased along with increasing proportions of soybean silage. Other rumen parameters, including gas production, ammonia nitrogen, and total volatile fatty acids, were variable. However, they tended to increase with increasing proportions of soybean silage. In the second experiment, 60 Hanwoo steers were allocated to one of three dietary treatments, namely, CON (concentrate with Italian ryegrass), CS (concentrate with corn silage), CS4% (concentrate with corn silage and 4% of soybean silage). Animals were offered experimental diets for 110 days during the growing period and then finished with typified beef diets that were commercially available to evaluate the effect of soybean silage on animal performance and meat quality. With the soybean silage, the weight gain and feed efficiency of the animal were more significant than those of the other treatments during the growing period (p<0.05). However, the dietary treatments had little effect on meat quality except for meat color. In conclusion, corn silage mixed with soybean silage even at a lower level provided a greater ruminal environment and animal performances, particularly with increased carcass weight and feed efficiency during growing period.
        4,300원
        7.
        2021.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : In this study, we aimed to investigate the heat transfer characteristics of asphalt mixtures by water saturation. METHODS : On the basis of the literature review, the heat transfer characteristics of the samples were analyzed using a thermal accumulation experiment. The types of samples used were WC2 (dense asphalt mixture), ReWC2 (used 30% recycled aggregate), and PA13 (drainage asphalt mixture). The samples were compacted using a gyratory compactor. An infrared lamp simulating insolation was used to continuously heat the asphalt sample. Through this experiment, the upper and lower temperatures and heat flux of the specimen according to its thickness and condition were measured, and the change in its thermal conductivity was analyzed. RESULTS : The results of the laboratory experiment indicated that the dry sample showed lower thermal conductivity than the saturated sample. The amount of evaporation varied depending on the internal pores of the sample. Additionally, the amount of evaporation changed the heat transfer characteristics of the specimen. CONCLUSIONS : An asphalt mixture with high porosity decreased the degree of increase in thermal conductivity, compared to mixtures with low porosity, under semi-saturated conditions; this was attributed to the difference in thermal conductivity between air and water during saturation. The results of this study on the heat transfer characteristics of asphalt pavements could be used as basic data for thermal energy harvesting of asphalt pavements.
        4,000원
        10.
        2018.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was performed to evaluate the quality characteristics of functional Dasik prepared with a mixture of freeze-dried mealworm (Tenebrio molitor) powder and dried pollack powder along with assessment of the general and fatty acid compositions of mealworms. General compositions, except for moisture content of freeze-dried mealworm powder, were higher than those of raw mealworms. The ratios of saturated fatty acids and unsaturated fatty acids of freeze-dried mealworm powder and raw mealworms were 1:3.31 and 1:3.19, respectively. Amounts of oleic acid, which was the most abundant among unsaturated fatty acids, of freeze-dried mealworm powder and raw mealworms were 41.12 and 37.84%, respectively. For color values, greater content of freeze-dried mealworm powder in functional Dasik resulted in lower L and b scores, whereas a value increased. In the case of mechanical properties, greater content of freeze-dried mealworm powder resulted in significant reduction of hardness, chewiness, and gumminess. In the case of sensory evaluation, color, taste, and overall quality of DPMD50, which was prepared with a 1:1 ratio of freeze-dried mealworm powder and dried pollack, were the highest. It was concluded that DPMD50 is a nutritious combination of edible insects and fish for protein fortification for growth and the elderly.
        4,000원
        11.
        2017.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A Nanosized WO3 and CuO powder mixture is prepared using novel high-energy ball milling in a bead mill to obtain a W-Cu nanocomposite powder, and the effect of milling time on the structural characteristics of WO3-CuO powder mixtures is investigated. The results show that the ball-milled WO3-CuO powder mixture reaches at steady state after 10 h milling, characterized by the uniform and narrow particle size distribution with primary crystalline sizes below 50 nm, a specific surface area of 37 m2/g, and powder mean particle size (D50) of 0.57 μm. The WO3-CuO powder mixtures milled for 10 h are heat-treated at different temperatures in H2 atmosphere to produce W-Cu powder. The XRD results shows that both the WO3 and CuO phases can be reduced to W and Cu phases at temperatures over 700oC. The reduced W-Cu nanocomposite powder exhibits excellent sinterability, and the ultrafine W-Cu composite can be obtained by the Cu liquid phase sintering process.
        4,000원
        12.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Purple-fleshed potato powder (PFPP) was investigated to determine optimal mixing ratio with milk powder and dextrin to produce a ready-to-eat mashed potato powder. The rheological characteristics, color, and anthocyanin contents were studied at a different concentration of ingredients. The power-law model was applied to explain the mechanical spectra of mashed potatoes which represented the change in structure induced by different mixing ratios. Mixture design was used to obtain the experimental points used to establish the empirical models to describe the effects of each ingredient on the characteristic of the mashed potato. The results of mechanical spectra showed that both storage and loss moduli (G' and G'') were significantly influenced by PFPP and milk powder concentration. The power law parameters n' and n'' showed higher values for the mashed potato with a lower concentration of PFPP and a higher concentration of milk powder, which showed that the gel networks involved in the mashed potato were weaker. The optimum mixing ratio with the highest redness and anthocyanin content, while maintaining the rheological properties similar to the commercial mashed potato, was determined as PFPP:milk powder:dextrin = 90.49:4.86:4.65 (w/w). The proportions of PFPP and milk powder in the formulation significantly changed the characteristics of mashed potato, whereas no significant effect of dextrin was observed in this formulation.
        4,000원
        13.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Purple-fleshed potato powder (PFPP) was investigated to determine optimal mixing ratio with milk powder and dextrin to produce a ready-to-eat mashed potato powder. The rheological characteristics, color, and anthocyanin contents were studied at a different concentration of ingredients. The power-law model was applied to explain the mechanical spectra of mashed potatoes which represented the change in structure induced by different mixing ratios. Mixture design was used to obtain the experimental points used to establish the empirical models to describe the effects of each ingredient on the characteristic of the mashed potato. The results of mechanical spectra showed that both storage and loss moduli (G' and G'') were significantly influenced by PFPP and milk powder concentration. The power law parameters n' and n'' showed higher values for the mashed potato with a lower concentration of PFPP and a higher concentration of milk powder, which showed that the gel networks involved in the mashed potato were weaker. The optimum mixing ratio with the highest redness and anthocyanin content, while maintaining the rheological properties similar to the commercial mashed potato, was determined as PFPP:milk powder:dextrin = 90.49:4.86:4.65 (w/w). The proportions of PFPP and milk powder in the formulation significantly changed the characteristics of mashed potato, whereas no significant effect of dextrin was observed in this formulation.
        4,000원
        15.
        2016.10 구독 인증기관·개인회원 무료
        Protein and polysaccharide are used as many food function including emulsifying and stabilizing agent. Some food emulsions are in low pH such as sorbet ice cream, soft drink, salad dressing etc. According to our previous study was found that fish gelatin (FG) and sodium alginate (AL) mixture provide the information to be a new food emulsifier including at low pH condition (pH 3.5). In addition the study of interfacial rheology has been interested to interpret the formation and stabilization of food emulsion. Then the objective of this study was to investigate the relationship between emulsifying characteristics and interfacial shear rheology of acidified emulsion which was stabilized by FG and AL mixture, compared with a commercial gum arabic (GA). The mixtures of FG and AL were separately prepared with phosphate-citrate buffer at pH 3.5 and 1 %w/v of total concentration. The ratio of FG:AL was 100:0, 80:20, 50:50, 80:20, and 0:100 by weight. They were mixed at 24±2 oC for 90 minutes and kept at the same temperature for 24 hours to reach equilibrium. The emulsion was prepared by adding 1.5 g of olive oil in 100 ml of mixture and homogenized by high speed homogenizer at 10,000 rpm for 10 min at 24±2 oC. The emulsion stabilized with 20:80 showed the best stability after 14 days. The result could be supported by low interfacial tension, high bulk viscosity, and electrostatic repulsion (minus value of electrophoretic mobility). For interfacial shear rheology (storage modulus, G' and loss modulus, G''), G' of 20:80 seem wider liner viscoelastic region which mean more resistance to fracture at interface. While the magnitude of G' and different value of G' and G'' were not difference. In addition, the interfacial shear viscosity of 20:80 also showed high resistance to flow at low shear rate (0.001 - 0.1 s-1). Keywords: Fish gelatin, Sodium alginate, Emulsion, Interfacial shear rheology
        16.
        2016.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : This study primarily focused on evaluating the performance characteristics of 4.75-mm nominal maximum aggregate size (NMAS) asphalt mixtures for their more effective implementation to a layered flexible pavement system. METHODS: The full-scale pavements in the FDOT’s accelerated pavement testing (APT) program, including 4.75-mm mixtures at the top with different thicknesses and asphalt binder types, were considered for the faster and more realistic evaluation of the rutting performance. The results of superpave indirect tensile (IDT) tests and hot-mix asphalt fracture mechanics (HMA-FM) based model predictions were used for cracking performance assessments. RESULTS: The results indicated that the rutting performance of pavement structures with 4.75-mm mixtures may not be as good as to those with the typical 12.5-mm mixtures, and pavement rutting was primarily confined to the top layer of 4.75-mm mixtures. This was likely due to the relatively higher mixture instability and lower shear resistance compared to 12.5-mm mixtures. The energy ratio (ER) and HMA-FM based model performance prediction results showed a potential benefit of 4.75-mm mixtures in enhanced cracking resistance. CONCLUSIONS : In relation to their implementation, the best use of 4.75-mm mixtures seem to be as a surface course for low-trafficvolume applications. These mixtures can also be properly used as a preservation treatment that does not necessarily last as long as 12.5-mm NMAS structural mixes. It is recommended that adequate thicknesses and binder types be considered for the proper application of a 4.75-mm mixture in asphalt pavements to effectively resist both rutting and cracking.
        4,000원
        18.
        2013.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated the quality characteristics of black soybean paste(Daemacjang) with black soybean content and salt concentration. The total acidity increased as the pH decreased during fermentation period. The amino-type nitrogen content of all samples increased significantly during fermentation time. Total cell counts was not significantly different during fermentation, and mold counts decreased at 3 log cycles. The cell counts of lactic acid bacteria decreased approximately 2 to 3 log cycles in 10% salt concentration (treat B and C), and were not detected in treat A and D. Total polyphenol contents of treat A, B, and C were 42.77%, 52.99% and 52.95% during fermentation up to 70days, respectively, which was higher than D (39.86%). In a sensory evaluation, treat B showed the highest scores for overall acceptability.
        4,000원
        19.
        2013.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The quality characteristics of Korean rice cakes (Karedduk) with a mixture of maltooligosaccharide and OSA (octenyl succinic acid starch) added, after 2 and 24 hr of storage at 5℃, was analyzed. A central composite design was used for arrangement of treatment. The two independent variables selected for retarding retrogradation analysis were amounts of maltooligosaccharide (x) and OSA (y). Maltooligosaccharide was added at 0, 3, 6, 9, and 12% levels, and OSA added at 0, 0.3, 0.6, 0.9, and 1.2% levels, to dry rice flour. The texture properties analysis using a Texture Analyzer revealed that the springiness and cohesiveness (p<0.01), chewiness, gumminess and hardness (p<0.001) were significantly different after 24 hr of storage at 5℃. The effect of retarding retrogradation of Korean rice cakes with added mixtures of maltooligosaccharide and OSA showed an increasing trend as the amount of maltooligosaccharide increased. Overall, the instrumental texture properties were highly correlated with the sensory characteristics. These results suggest that adding a mixture of 6% maltooligosaccharide and 0.6% OSA to Korean rice cakes (Karedduk) is effective for retarding retrogradation.
        4,000원
        20.
        2008.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To investigate the synergy effect on the pyrolysis of mixture of polyethylene(PE) and polystyrene(PS), the pyrolysis of PE, PS and the mixture of PE-PS was carried out in a batch reactor at the atmospheric pressure and 450℃. The pyrolysis time was from 20 to 80 mins. The liquid products formed during pyrolysis were classified into gas, gasoline, kerosene, gas oil and heavy oil according to the distillation temperatures based on the petroleum product quality standard of Korea Institute of Petroleum Quality. The analysis of the product oils by GC/MS showed that the new components produced by mixing were not detected. The synergy effect according to mixing of PE and PS did not also appear. The conversion and yield of mixtures were in proportion to the mixing ratio of sample.
        4,000원
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