• Animal Bioscience
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• 제34권6호
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• pp.1049-1060
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• 2021

Objective: This study assessed the effect of different levels of xylanase, β-glucanase and phytase on intestinal enzyme activities and tibia bone development in broiler chickens fed wheat-based diets. Methods: Twelve experimental diets were formulated using a 3×2×2 factorial design (three doses of phytase and two doses of both xylanase and β-glucanase) and offered to 648 day-old Ross 308 male chicks having 6 replicates groups with 9 birds per replicate and lasted for 35 days. Results: An interaction between the enzymes products improved (p<0.01) the activity of chymotrypsin. Protein content at d 10 was highest (p<0.001) with addition of phytase while general proteolytic activity (GPA) (p<0.02) and lipase activity (p<0.001) were decreased. At d 24, there were improvements in protein content (p<0.01) and lipase (p<0.04) with supplementation of superdose phytase. Addition of superdose phytase decreased in chymotrypsin (p<0.02), trypsin (p<0.01) and GPA (p<0.001). The optimum dose of xylanase decreased the chymotrypsin activity (p = 0.05), while the GPA (p<0.001) was increased with the optimum level of β-glucanase. Superdose phytase supplementation at d 10 improved maltase (p = 0.05), sucrase (p<0.001) and alkaline phosphatase (p<0.001) activities in the jejunum while aminopeptidase activity was highest (p<0.005) with the low level of phytase. Protein content of jejunum mucosa was bigger (p<0.001) in birds fed superdose phytase while maltase activity (p<0.001) at d 24 was reduced by this treatment. Sucrase (p<0.04) and aminopeptidase activities (p<0.001) improved when diets supplemented with low levels of phytase. Tibia bone breaking strength was highest (p<0.04) with addition of low level of superdose phytase or optimum level of β-glucanase. Bone dry matter content decreased (p<0.04) when diets supplemented with phytase. Conclusion: From the results obtained in this study, supplementation of superdose phytase was the most effective, however, the cost-benefit analysis of the use of such a dose needs to be evaluated.

• 한국식품조리과학회지
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• 제27권6호
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• pp.723-733
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• 2011

This study was performed to examine the optimum addition amount of Hizikia fusiformis powder to be used with rice flour in the preparation of Hizikia fusiformis Sulgidduk (traditional rice cake). Hizikia fusiformis powder was added to rice powder at ratios of 5, 10, 15 and 20% (w/w). The moisture content of Sulgidduk was increased with the addition of Hizikia fusiformis powder, whereas the pH content was decreased. The addition also lowered the lightness and yellowness values but increased the greenness value. Mineral contents were increased. Hardness, springiness, and brittleness were decreased, and cohesiveness was increased as the added powder content also increased. In the sensory evaluation of Hizikia fusiformis Sulgidduk, color, flavor, taste, softness, chewiness, moistness, cohesiveness, and overall acceptability characteristics were all highest at the 10% addition level. Thus it can be proposed that this is the ideal level of Hizikia fusiformis addition in terms of the sensory properties of the cooked product.

• 한국식품영양과학회지
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• 제23권3호
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• pp.496-501
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• 1994

The synthesis of lauryl palmitate from palmitic acid and lauryl alcohol was investigated in organic solvents using lipase. Water-immiscible organic solvent such as hexane, toluenem cyclohexane, and isooctane were found to be suitable of ester synthesis . The effect of water content on the initial rate of conversion was examined . As the content increased, the reaction rate increased. But addition of water in organic solvent decreased therostability of enzyme . The best lauryl palmitate synthesis was achieved with water content of 0.2-0.4% reaction temperature of 4$0^{\circ}C$ and 45$^{\circ}C$ for Candida cylindracea lipase porcine, pancreatic lipase, respectively. when ester synthesis was carried out under the optimum conditions, the conversion yield of palmitate into lauryl palmitate after 70hrs reached 85% and 69 % for the Candida cylindracea lipase and porcine opancreatic lipase, respectivley.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 학회창립 10주년 기념 1999년도 가을 학술발표회 논문집
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• pp.175-178
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• 1999

In most domestic construction fields, excessive cement content has been used because of stubborn official inspection. The purpose of this study is to reduce the cement content of mix proportioning for the decrease of hydration heat, brittleness and drying shrinkage which governs durability of concrete significantly. Parameters includes the compressive strengths, type and dosage rate of chemical and mineral admixtures and types of concrete. It is found that the chemical admixture is efficient to the reduction of cement content for high strength concrete (400kg/$\textrm{cm}^2$) and the effectiveness of mineral admixtures in the low strength concrete is somewhat higher than the high strength concrete.

• 한국식품저장유통학회지
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• 제8권2호
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• pp.169-174
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• 2001

Chemical analysis and optimum preparation conditions for fig jam were investigated. Soluble solids, acid content and vitamin C of fig was 12.20。Brix, 0.14% and 2.27 mg/100g, respectively. Carbohydrate in fig juice was consisted of 54.43% glucose and 44.53% fructose. Potassium content of fig was 178.0 mg/100g. Moisture content and total sugar of fig fruit was 88.35% and 9.47%. In preparation of fig jam, the addition of 0.2% Citrus natsudaidai juice and 0.5% C. lemon juice as acid source was the best in regard with color and flavor determined by sensory evaluation. The ratio of sucrose : honey : oligo sugar(70:20:10) was also the best in addition of sugar source 60%(w/w) in total. Fig jam prepared in this experiment was better than that of commercial products in sensory evaluation, and microbial growth of this product was not recognized for one month at 30$\^{C}$.

• Computers and Concrete
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• 제5권1호
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• pp.21-36
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• 2008

Steel fiber reinforced concrete is increasingly used day by day in various structural applications. An extensive experimentation was carried out with w/cm ratio ranging from 0.25 to 0.40, and fiber content ranging from zero to1.5 percent by volume with an aspect ratio of 80 and silica fume replacement at 5%, 10% and 15%. The influence of steel fiber content in terms of fiber reinforcing index on the compressive strength of high-performance fiber reinforced concrete (HPFRC) with strength ranging from 45 85 MPa is presented. Based on the test results, equations are proposed using statistical methods to predict 28-day strength of HPFRC effecting the fiber addition in terms of fiber reinforcing index. A strength model proposed by modifying the mix design procedure, can utilize the optimum water content and efficiency factor of pozzolan. To examine the validity of the proposed strength model, the experimental results were compared with the values predicted by the model and the absolute variation obtained was within 5 percent.

• Elastomers and Composites
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• 제52권1호
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• pp.17-21
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• 2017

The optimum mixing conditions of silica and silane containing rubber composites were evaluated by investigating the properties of rubber composites prepared with a silica composition of 10, 20, 40, 60, and 80 g, respectively. The crosslinking rate decreased with increasing silica content, with he promoters being adsorbed on the silica surface with in the rubber composite. As a result, the increase in crosslinking time resulted in the destruction of the silica structure. The increase of the bound rubber content due to the destruction of the silica structure inhibited the chain motion of the polymer molecules and reduced the cohesion of the silica itself. Finally, the increase of silica content showed the increase of hardness, tensile strength, and storage modulus of rubber composites.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2016년도 춘계 학술논문 발표대회
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• pp.28-29
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• 2016

Recently, the attention on high tensile, and high performance cementitious composite (HPFRCC) which can minimize the damage from explosion of inflammable gas and chemicals has been increased. In spite of outstanding tensile performance, HPFRCC has the drawbacks of fiber ball, undesirable cost, and high autogenous shrinkage. therefore, in this research, to develop the optimum HPFRCC, the fundamental properties and autogenous shrinkage of HPFRCC was analyzed depending on various combination and content of organic and inorganic fibers.

• Fibers and Polymers
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• 제7권2호
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• pp.95-104
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• 2006

In order to improve the water swelling, thermal/mechanical and adhesion properties of waterborne polyurethane (WBPU), a series of the crosslinkable WBPUs containing hydrophilic ionic component, dimethylol propionic acid (20 mole%), were prepared by in-situ polymerization using a cross-linker hexakis (methoxymethyl) melamine (HMMM). Effects of the HMMM content (2, 4, and 6 wt%) and curing temperature on these properties of the crosslinked WBPUs samples were investigated. All properties were found to increase with increasing HMMM content. It was found that the optimum curing temperature of the WBPU films and adhesives was near $120^{\circ}C$, which was not dependent on the HMMM content.

• 한국농공학회:학술대회논문집
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• 한국농공학회 1999년도 Proceedings of the 1999 Annual Conference The Korean Society of Agricutural Engineers
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• pp.313-318
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• 1999

This study is basic research to improve quality of asphalt concrete mixture, to preserve environment, and to recycle waste vinly. The mixing method and proper content of waste vinyl were determined through preliminary mix design. This study performed mix designs using 2 type gradations of aggregate in addtion content of wate vinly. Marshall stability at optimum asphalt content of asphalt concrete mixture addtin wate vinly was satisfied with the specification of the Ministry of Construction and Transportation , and its values indicated that dense grade asphalt concrete mixture containing waste vinyl were higher than common dense grade mixture (control). From this study, it was confirmed that addtion of waste vinyl improved quality of asphalt concrete mixture.