• Journal of the Korea Concrete Institute
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• v.19 no.6
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• pp.763-771
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• 2007

Over the last few decades, many researches have been conducted in order to find solution to the problem of corrosion in steel reinforced concrete. As a result, methods such as the use of stainless steel bars, epoxy coatings, and concrete additives, etc., have been tried. While effective in some situations, such remedies may still be unable to completely eliminate the problems of steel corrosion. Fiber reinforced polymer (FRP) elements are appealing as reinforcement due to some material properties such as high tensile strength, low density, and noncorrosive. However, due to the generally lower modulus of elasticity of FRP in comparison with the steel and the linear behavior of FRP, certain aspects of the structural behavior of RC members reinforced with FRP may be substantially different from similar elements reinforced with steel reinforcement. This paper presents the flexural behavior of one-way concrete slabs reinforced with FRP bars. They were simply supported and tested in the laboratory under static loading conditions to investigate their crack pattern and width, deflections, strains and mode of failure. The experimental results shows that behavior of the FRP reinforced slabs was bilinearly elastic until failure. Also, the results show that the FRP overreinforced concrete beams in this study can be safe for design in terms of deformability.

• Food Science and Preservation
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• v.6 no.2
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• pp.167-172
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• 1999

The noodle making characteristics were investigated for both eleven varities of Korean wheat, such as Chokwangmil, Geurumil, Eunpamil, Tnpdongmil, Woorimil, Oigeurmil, Alchanmil, Cobunmil, Geumgangmil, Seodunmil and Suwon 265, and two varieties of imported wheat, DNS(Dark Northern Spring Wheat) and ASW(Australian Standard White). After cooking of dry-noodle, the elasticities were 0.59-0.79 in the native wheat and 0.55-0.57 in the imported wheat. Among the varieties showing the highest value in the various texture properties of cooked dry-noodle, Alchanmil was highest in gumminess, Geungangmil in cohesiveness, Olgeurumil in adhesiveness, Geurumil in fimmess, Chokwang in chewiness, Tapdongmil in tensile strength Gobunmil in breaking strength. After cooking the wet-noodle, Tapdongmil in elasticity, Geurumil in adhesiveness, Geumgangmil in gumminess, cohesiveness, firmness and chewiness, and Suwon 265 in tensile strength showed the highest values in the respective textural properties. From the sensory evaluation of the cooked dry-noodle, the significant differences (p<0.05) among wheat varieties were observed in color, texture and overall quality. As a result, ASW was excellent in our all qualities of cooked dry-noodle followed by Tapdongmil, Alchanmil and Geumgangmil. The cooked wet-noodle also showed the high sensory scores (p<0.01) were showing the best in Tapdongmil, followed by Eunpamil, Geumgangmil and Woorimil.

• Culinary science and hospitality research
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• v.15 no.2
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• pp.84-92
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• 2009

Fish patty is a product spotlighted recently in the application area of functional food because its main ingredients are soybean and fish with various functions which make it highly digestible, tasty, rich with protein and calcium, and with low fat. Thus, in order to optimize fish patties, this study analyzed their water content, colors, texture and sensory characteristics according to the addition of soybean powder. As a result, water content and lightness decreased with the increase of the addition of soybean powder while hardness, elasticity, chewiness, and gumminess increased with the increase of the addition of soybean powder. Among sensory characteristics, taste, chewiness and texture were highest in S2, and in general evaluation, S2 received the highest score. Thus, S2 was found the most appropriate addition of soybean powder in making fish patties. Based on the results of this study, if fish patties to which soybean powder is added can be used in hamburgers and other food products for the diversity, functionality, and high quality of processed food products using soybean and fish, people's appreciation of hamburgers will be changed, and this will bring a new turning point to the consumption of hamburgers. Furthermore, it is believed that the development of healthy patty-type soybean powder products may resolve worries about fast food and quality-related and health-related problems in hamburger patties.

• Journal of Korean Society of Forest Science
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• v.80 no.2
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• pp.210-219
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• 1991

This study is to diagnose the drought tolerance of twenty broad-leaved tree species by the pressure-volume(P-V) curves. As for the diagnosis of drought tolerance, the valuable water relations parameters obtained from P-V curves are the osmotic potential at full turgor, ${\Psi}_0{^{sat}}$, osmotic potential at incipient plasmolysis, ${\Psi}_0{^{tlp}}$, maximum bulk modulus of elasticity, $E_{max}$, and relative water content at incipient plasmolysis, $RWC^{tlp}$. Also, the figures related to the diagnosis of drought tolerance are the free water content (FWC) versus leaf water potential(${\Psi}_L$), volume-averaged turgor pressure ($P_{vat}$) versus leaf water potential (${\Psi}_L$), and H$\ddot{o}$fler diagram. In this study, the relatively high drought tolerant species are Fraxinus rhynchophylla, Quercus acutissima, Quercus serrata, Quercus aliena, and Populus alba${\times}$glandulosa ; the relatively low drought tolerant species are Fraxinus mandshurica, Betula platyphylla var. japonica, Populus euramericana, Kalopanax pictum, Carpinus loxiflora, Carpinus cordata, Prunus sargentii, Prunus leveilleana, and Cornus controversa ; medium species are Quercus mongolica, Acer mono, Acer triflorum, Acer pseudo-sieboldianum, Ulmus davidiana, and Zelkova serrata.

• Journal of Mushroom
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• v.10 no.3
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• pp.115-119
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• 2012

'Gonji-5ho', a new variety of oyster mushroom, for the bag culture, was bred by mating two monokaryons isolated from 'Chiak-3ho'and 'Suhan-1ho'. In the characteristics of fruit body, pilei were thick and gray and stipes were thick, and long, and soft. It was better in elasticity and cohesivness of tissue compared to Suhan-1ho. Compared to other varieties, it was suitable to grow at higher temperature. The range of optimum temperature for the mycelial growth was around 26~29 and that for the pinheading and growth of fruit body was around $18{\sim}20^{\circ}C$. But when it was cultuered in lower than $15^{\circ}C$, growth was not uniform, culture period was longer, and stipes were uneven. In the bag culture, it was required around 18 days in incubation period and 3 days in primordia formation. The fruit body growth was vital and uniform. The yield was 221.4g/1kg bag.

• Journal of Life Science
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• v.22 no.6
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• pp.807-814
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• 2012

Saururus chinensis has long been widely used in oriental folk medicines to treat diseases. In the current study, organic solvent fractions obtained from the main methanolic extract of S chinensis were evaluated for their antioxidative and related physiological activities. The antioxidant activity of the fractions was measured using DPPH free radical scavenging activity, increased in a dose-dependent manner, and the $ED_{50}$ of the ethyl acetate fractions exhibited a value of 12.84 ${\mu}g/ml$ higher than 27.22 ${\mu}g/ml$ compared to the BHT. Also, the cell viability of S. chinensis on $H_2O_2$-induced HDF cell death ($IC_{50}$) showed the highest cell viability of 89.39% in 50 ${\mu}g/ml$ of ethyl acetate fraction and 67.98% of visible cell survival rate in n-butanolic fraction. Meanwhile, all fractions of the S. chinensis extract led to a slight down regulation of the mRNA expression of fibulin-5, which is related to skin elasticity, and the ethyl acetate fraction having high antioxidant activity showed a markedly inhibitory effect on chick embryonic angiogenesis using the CAM assay. These results suggest that the ethyl acetate fraction of S. chinensis extract could be a good material in therapeutic application for antioxidant and related anti-angiogenesis activities.

• Korean Journal of Applied Biomechanics
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• v.13 no.3
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• pp.81-98
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• 2003

The purpose of this study is to closely examine kinematic characteristics by jump phase of Li Xiaopeng motion in horse vaulting and provide the training data. In doing so, as a result of analyzing kinematic variables through 3-dimensional cinematographic using the high-speed video camera to Li Xiaopeng motion first performed at the men's vault competition at the 14th Busan Asian Games, the following conclusion was obtained. 1. It was indicated that at the post-flight, the increase of flight time and height and twisting rotational velocity has a decisive effect on the increase of twist displacement. And Li Xiaopeng motion showed longer flight time and higher flight height than Ropez motion with the same twist displacement of entire movement. Also the rotational displacement of the trunk at peak of COG was much short of $360^{\circ}$(one rotation) but twist displacement showed $606^{\circ}$. Likewise, Li Xiaopeng motion was indicated to concentrate on twist movement in the early flight. 2. It was indicated that at the landing, Li Xiaopeng motion gets the hip to move back, the trunk to stand up and the horizontal velocity of COG to slow down. This is thought to be the performance of sufficient landing, resulting from large security of rotational displacement of airborne and twist displacement. 3. It was indicated that at the board contact, Li Xiaopeng motion made a rapid rotation uprighting the trunk to recover slowing velocity caused by jumping with the horse in the back, and has already twisted the trunk nearly close to $40^{\circ}$ at board contact. Under the premise that elasticity is generated without the change of the feet contacting the board, it will give an aid to the rotation and twist of pre-flight. Thus, in the round-oH phase, the tap of waist according to the fraction and extension of hip joint and arm push is thought to be very important. 4. It was indicated that at the pre-flight, Li Xiaopeng motion showed bigger movement than the techniques of precedented studies rushing to the horse, and overcomes the concern of relatively low power of jump through the rapid rotation of the trunk. Li Xiaopeng motion secured much twist distance, increased rotational distance with the trunk bent forward, resulting in the effect of rushing to the horse. 5. At horse contact, Li Xiaopeng motion makes a short-time contact, and maintains horse take-off angle close to vertical, contributing to the increase of post-flight time and height. This is thought to be resulted from rapid move toward movement direction along with the rotational velocity of trunk rapidly earned prior to horse contact, and little shave of rotation axis according to twist motion because of effective twist in the same direction.

• Journal of the Korea Concrete Institute
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• v.17 no.1 s.85
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• pp.19-25
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• 2005

Recycling of waste materials in the construction Industry is a useful method that can cope with an environment restriction of every country. In this study, synthetic lightweight aggregates are manufactured with recycled plastic and fly ash with 12 percent carbon. Nominal maximum-size aggregates of 9.5 mm were produced with fly ash contents of 0, 35, and $80\%$ by the total mass of the aggregate. An expanded clay lightweight aggregate and a normal-weight aggregate were used as comparison. Gradation, density, and absorption capacity are reported for the aggregates. Five batches of concrete were made with the different coarse aggregate types. Mechanical properties of the concrete were determined including density, compressive strength, elastic modulus, splitting tensile strength, fracture toughness, and fracture energy. Salt-scaling resistance, a concrete durability property, was also examined. Compressive and tensile strengths were lower for the synthetic aggregates; however, comparable fracture properties were obtained. Relatively low compressive modulus of elasticity was found for concretes with the synthetic lightweight aggregate, although high ductility was also obtained. As nv ash content of the synthetic lightweight aggregate increased, all properties of the concrete were improved. Excellent salt-scaling resistance was obtained with the synthetic lightweight aggregate containing 80 percent fly ash.

• Journal of the Korea Concrete Institute
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• v.13 no.5
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• pp.476-483
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• 2001

초유동콘크리트는 유동성 증진 및 충전성 향상을 위해 단위분체량을 크게하기 때문에 콘크리트의 고강도화와 수화발열량을 증가시키는 문제점을 가지고 있다. 이에 본 연구는 초유동콘크리트의 강도조절과 수화열 저감을 위해 쇄석분을 이용하여 초유동콘크리트의 강도, 유동성, 내구성능 및 건조수축 특성을 검토하였다. 실험결과 쇄석분은 치환율 10% 증가시마다 무치환시의 압축강도를 약 10~15%씩 감소시키며, 변형계수와 물구속비를 감소시켜 초유동콘크리트의 유동성 향상에 효과적이다. 또한 초유동콘크리트에서 쇄석분 10%치환시 마다 단위시멘트량 감소에 따른 최고 단열온도상승량을 약 4$^{\circ}C$씩 감소시켰다. 반면 건조수축량은 10%치환시 마다 약 5%증가시켰다. 한편 초유동콘크리트의 내구성능은 단위분체량과 유동성향상에 따른 조직의 치밀화로 쇄석분 치환에 관계없이 상대동탄성계수 90%이상으로 우수하게 나타났다. 이와 같이 분체로서 쇄석분 사용은 치환량에 따른 초유동콘크리트의 강도조절이 가능하며 수화발열량을 저감시킬 수 있다. ^ x Super flowing concrete causes high strength and the increase of heat of hydration because of the big unit powder content of concrete to increase flowability and to improve compact of concrete. Therefore, this study investigates the characteristic properties of strength, flowability, durability and drying shrinkage to control strength and to reduce heat of hydration of super flowing concrete using crushed stone fines. According to the experimental results, when crushed stone fines are increased every 10%, 10~15% of compressive strength is decreased and flowability of super flowing concrete is effectively improved due to the decrease of modulus of deformation and confined water ratio. When crushed stone fines are replaced every 10%, 4$^{\circ}C$ of the highest adiabatic temperature rise is decreased by reducing the unit cement. However, 5% of drying shrinkage is increased in the same condition. In the meantime, durability of super flowing concrete is excellent, having over 90 % of good relative dynamic modulus of elasticity due to fineness of formation caused by the increase of the unit powder content and the improvement of flowability, without regard to the replacement of crushed stone fines. Therefore, it can be said that the usage of crushed stone fines can control the strength of super flowing concrete by replacement and reduce heat of hydration.

• Journal of the Korea Concrete Institute
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• v.13 no.5
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• pp.438-446
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• 2001

Recently, porous concrete has been used for the purpose of decreasing the load of earth environment. It consists solely of cement, water and uniform-sized coarse aggregate. And its fundamental properties will be considerably affected by the physical properties of aggregate because the aggregate occupies for the most part in its mix proportion. For such a reason, this study was carried out to investigate the influence of the sizes and kinds of aggregate for the fundamental properties of porous concrete. It showed that the fundamental properties of porous concrete were the similar value in all sizes of aggregate except in the case of using the 2.5∼5㎜ aggregate and were varied according to the kinds of aggregate. In particular, compressive strength of porous concrete using 2.5∼5㎜ aggregate was more higher than that using other aggregate, and its void ratio and coefficient of permeability was lower. And the maintenance capacity of permeability of porous concrete was varied by the sizes and the kinds of aggregate. In particular, it was greatly decreased in case of using the 2.5∼5㎜ aggregate. And unlike dynamic modulus of elasticity of ordinary concrete, that of porous concrete was very high value in early ages and was slowly increased after that time.