• Title/Summary/Keyword: Experimental formula

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An analysis of interception capability of storm water grate inlet in road (도로 빗물받이의 차집능력 분석)

  • Lee, Jong-Tae;Yoon, Sei-Eui;Kim, Kap-Soo;Kim, Young-Ran;Ryu, Taek-Hee
    • Journal of Korea Water Resources Association
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    • v.36 no.3 s.134
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    • pp.465-480
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    • 2003
  • The interception capabilities of storm water grate inlet were analyzed in this paper. The hydraulic model lot gutter flow was used to estimate the interception capability. With the consideration of width and length of road, gutter discharges were ranged of 4-15l/sec. The transverse slopes of gutter were selected 4, 7 and 10%. The longitudinal slopes were 0, 2, 5 and 7%. The four sizes of storm water grate inlet were used in this experiments ($30\times40cm,\;40\times50cm,\;40\times100cm,\;40\times150cm$). The total number of experimental cases were 240. As the transverse slopes of gutter increased, the interception capability also increased. As the flow width in gutter and the discharge were lower, the interception efficiencies increased and the longitudinal slopes of road increased, the interception efficiencies decreased. The empirical formula with the factors of total inflow discharge, the longitudinal slope and the transverse slope of gutter were derived. These equations could be used to estimate the intercepting discharge of grate inlet. The reasonable construction space of grate inlet for the road widths, the longitudinal slopes, the transverse slopes and the grate inlet sizes were suggested.

Investigation on Response Modification Factor of RC Structural Walls in Apartment Buildings (아파트 건물의 구조 벽체에 대한 반응수정계수)

  • 한상환;오영훈;이리형
    • Journal of the Korea Concrete Institute
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    • v.13 no.6
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    • pp.544-552
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    • 2001
  • Korea is classified into low and moderate seismic zone from the view-point of seismic hazard level. Korean seismic provisions has been developed based on UBC and ATC 3-06. Thus, in calculation of design base shear according to Korean provisions response modification factor (R) is included in the formula of design base shear. The major role of this factor is to reduce the elastic design base shear whereby structures can behave in inelastic range during design level earthquake ground motions(mean return period of 475 yrs.). R factor is assigned according to material and structural systems. In this study, R factor for bearing wall system is considered. Most of the walls of apartment buildings in Korea resist gravity and seismic loads simultaneously so that this wall system can be classified into bearing wall system. Structural details of these walls are different from those used in Japan and U.S.. They are all rectangular in sectional shape rather than barbell in shape, and also have special lateral reinforcement details at the boundaries of a wall. In Korean seismic design provisions(1988), two different values(3.0 and 3.5) of R factor are assigned to the bearing wall systems according to the wall details. However, in updated seismic provisions(2000), only one value is assigned to R factor(3.0) irrespective of wall details. In this study, the design base shear values in Korean seismic design provisions(1988, 2000), ATC 3-06, UBC are compared. Also experimental study was carried out to evaluate the seismic performance of structural walls. For this purpose, five test specimens were made which have special details used in apartment bearing wall systems in Korea. Based on the results of this study, response modification factor for bearing wall system is discussed.

Flexural Behavior of High Performance Fiber Reinforced Cementitious Composites (HPFRCC) Beam with a Reinforcing Bar (휨 철근이 배근된 HPFRCC 보 부재의 휨 거동)

  • Shin, Kyung-Joon;Kim, Jae-Hwa;Cho, Jae-Yeol;Lee, Seong-Cheol
    • Journal of the Korea Concrete Institute
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    • v.23 no.2
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    • pp.169-176
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    • 2011
  • In this study, the flexural test for reinforced high performance fiber reinforced cementitious composites (R/HPFRCC) members has been conducted in order to investigate the flexural behavior including the effect of an ordinary tensile reinforcing bar. Through the test, it was observed that the flexural strength increased due to the stable tensile stress transfer of HPFRCC, even up to the ultimate state. In addition, no localized crack appeared until the yielding of the reinforcement. From the layered section analysis of the tested members, it was found that the analysis with the tensile model obtained from the tension stiffening test showed better agreement with the flexural test results, whereas the analysis with direct tension test results overestimated the flexural capacity. Through the experimental and analytical studies, two flexural failure modes have been defined in this paper; concrete crushing at the top compression layer or tensile failure at the bottom tensile layer of the beam section. Based on these two flexural failure modes, a simple formula that estimates the ultimate flexural strength of the member has been proposed in this paper. The proposed equations can be useful in a design and an analysis of R/HPFRCC members.

Limited-Ductile Seismic Design and Performance Assessment Method of RC Bridge Piers Based on Displacement Ductility (변위연성도 기반 철근콘크리트 교각의 한정연성 내진 설계법과 성능평가 방법)

  • Park, Chang-Kyu;Chung, Young-Soo;Lee, Dae-Hyoung
    • Journal of the Korea Concrete Institute
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    • v.19 no.1
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    • pp.19-26
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    • 2007
  • Until recently Korea is considered to be immune from the earthquake hazard because it is located for away from the active fault. However, we have noticed that recent strong earthquakes inflicted enormous losses on human lives and nation's economy all over the world. Hence, there has been raised the importance of the earthquake resistant design for various infrastructures. In this research, new methodologies for the seismic design and performance assessment of reinforced concrete(RC) bridge pier were proposed from experimental results of 82 circular RC bridge piers and 54 rectangular RC bridge piers tested in domestic and aboard. New seismic design method was based on the concept of the limited ductile design, which could be practically used for low or moderate seismic regions like Korea. Further study for the seismic safety of RC bridge piers was carried out to enhance the seismic performance of aged RC bridge piers, which were designed and constructed before implementing the 1992 seismic design provision in Korea. New formula for the seismic performance assessment of RC bridge piers was proposed and practically used for the decision on the need of repair and retrofit of many aged RC bridge piers.

Effects of Barley Noodles Contained Mulberry Leave Extracts on Blood Glucose Regulation in Diabetic Mice (당뇨 쥐에서 상엽추출물을 첨가한 보리면의 혈당조절효과)

  • Park, Chung-Mu;Yoon, Hyun-Seo
    • Journal of the Korea Convergence Society
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    • v.9 no.8
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    • pp.101-108
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    • 2018
  • This study aimed to investigate the blood glucose regulatory effect of barley noodles contained mulberry leaves water extract (MLWE) in diabetic mice in order to provide fundamental data as a functional food. ICR mice were divided into six groups as follows: normal control, positive control, barley control, mulberry control, barley+MLWE 2.5% and barley+MLWE 5% groups. High fat/high carbohydrate diet was fed for 4 weeks and diabetes mellitus was induced by i.p. injection of streptozotocin and nicotinamide. After diabetes induction, experimental diet was supplemented for 2 weeks and simultaneous measurement of body weight, blood glucose (including glucose tolerance test), liver function and blood lipid profile was conducted. As a result, there was less decrease in body weight compared to the positive control group in the groups that supplemented barley and MLWE together than the group ingesting barley and MLWE alone. In addition, regulatory effects on blood glucose, liver function and blood lipid concentration were also stronger in barley and MLWE concurrently supplemented groups. Consequently, combination of barley and MLWE was effective in the regulation of body weight, blood glucose, liver function, and blood lipid in diabetic mice. Therefore, this recipe could be a promising strategy for beneficial effects in the patients of diabetes mellitus.

Effect of Different Feed Additives on Growth Performance and Blood Profiles of Korean Hanwoo Calves

  • Sarker, M.S.K.;Ko, S.Y.;Lee, S.M.;Kim, G.M.;Choi, J.K.;Yang, C.J.
    • Asian-Australasian Journal of Animal Sciences
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    • v.23 no.1
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    • pp.52-60
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    • 2010
  • This experiment was conducted on 60 Hanwoo calves comprising five feed additive groups, with 12 calves in each group, to determine the effects of additives at pre- and post-weaning on growth performance and blood profile. The groups were control, antibiotic (Neomycin 110 ppm), illite (2%), fermented green tea probiotics (FGTP, 0.5%), and mixed additives (FGTP 0.25%, illite 1% and licorice 0.1%). The calves were offered experimental pellet feeds ad libitum and after one month were supplied with imported timothy hay. They moved freely within the group and suckled their mother' milk during the pre-weaning stage (birth to 3 months) and were separated from their dam during the post-weaning stage (4-5 months). During the pre-weaning stage, the highest average daily gain (ADG) was recorded in the antibiotic- and mixed additive-fed groups followed by FGTP, control and illite groups. In the post-weaning stage, significantly higher total weight gain and ADG were recorded in both the FGTP and mixed additive groups compared to the other groups (p<0.05). Feed efficiency of mixed additive- and illite-fed calves were almost similar with antibiotic-fed calves compared to the other two groups, but the ADG was lowest in illite-fed calves during the pre-weaning stage. In contrast, post-weaning calves fed FGTP and mixed additives showed better feed efficiency. The values of hematological indices, differential leukocyte count, blood proteins and immunoglobulin among the additive-fed calves were not significantly different (p>0.05), although hemoglobin and hematocrit values were lower in FGTP compared to control, but similar in mixed additive and antibiotic groups. These results indicate no detrimental effects of feed additives on the blood profile of calves at both pre- and post-weaning age. Serum albumin in post-weaning calves of all feed additive groups were similar but significantly lower (p<0.05) than in the control group. Post-weaning, IgM was significantly lower (p<0.05) in illite-fed calves compared to other treatment groups, but there was no difference at pre-weaning. Considering all factors, the mixed feed additives and FGTP can be the replacement feed formula for antibiotic for Hanwoo beef calf production, especially when used post- weaning.

Prediction of Structural Behavior of FRP Rebar Reinforced Concrete Slab based on the Definition of Limit State (한계상태 정의에 따른 FRP Rebar 보강 콘크리트 슬래브의 구조거동 예측)

  • Oh, Hongseob;Kim, Younghwan;Jang, Naksup
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.40 no.4
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    • pp.371-381
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    • 2020
  • The failure mode of concrete reinforced with FRP is defined as the concrete crushing and the fiber rupture and the definition of limit state is a slightly different according to the design methods. It is relatively difficult to predict of FRP reinforced concrete because the mechanical properties of fibers are quite depending on its of fibers. The design code by ACI440 committee, which has been developed mainly on GFRP having low modulus of elasticity, is widely used, but the applicability on other FRPs of this code has not been sufficiently verified. In addition, the ultimate and serviceability limit state based on the ACI440 are comparatively difficult to predict the behavior of member with the 0.8~1.2 𝜌b because crushing and rupturing failure can be occurred simultaneously is in this region of reinforcement ratio, and predicted deflection is too sensitive according to the loading condition. Therefore, in this study, reliability and convenience of the prediction of structural performance by design methods such as ACI440 and MC90 concept, respectively, were examined through the experimental results and literature review of the beam and slab with the reinforcement ratio of 0.8 ~ 1.4. As a result of the analysis, it can be applied to the FRP reinforced structure in the case of the simple moment-curvature formula (LIM-MC) of Model Code, and the limit state design method based on the EC2 is more reliable than the ultimate strength design method.

Characteristics of Sponge Cakes with Replacement of Sucrose with Oligosaccharides and Sugar alcohols (올리고당과 당알콜을 이용한 스폰지 케익의 제조)

  • 김창순;이영순
    • Korean journal of food and cookery science
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    • v.13 no.2
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    • pp.204-212
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    • 1997
  • The characteristics of sponge cakes prepared with replacement of 30, 50, 75, or 100% of sucrose with isomaltooligosaccharide (IOS), fructooligosanharide (FOS), maltitol symp (MS), or maltitol powder (MP), were examined through physical measurement and sensory evaluation. The specific gravities of foams and cake batters were not significantly different among samples (p .0.05). The use of IOS increased the viscosity of cake batter. The cakes containing IOS, FOS, MS, or MP were softer than control cakes (sucrose 100%). Especially cakes prepared with 30, 50% IOS, or 75, 100% MP, appeared to be fragile. When increasing levels of IOS or FOS were incorporated in the cake formula, cake crust color was getting darker than that of control cake, whereas cake containing maltitol was getting lighter as the levels of replacement increased. Generally, the volume of cake containing FOS were superior to that of control cake, whereas those of cakes containing above 50% MP were inferior. Sensory analysis of experimental cakes did not show significant differences from the control cake for softness, springiness and gumminess. Sweetness increased replacing the sucrose with FOS, MS or MP (30, 50%) and moistness increased using IOS, FOS, MS, or MP without agreement with moisture contents of cakes. Replacement of 30, 50% sucrose with MS or 30% with MP did not affect greatly the physical measurements or sensory characteristics studied.

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Study on the Anti-Fatigue and Immune-Enhancing Effects of Gami-Yukmi-Jihwang- Tang (가미육미지황탕의 항피노와 면역 증강 효과에 대한 연구)

  • Kim Hyun Hee;Park Eun Jung;Kim Jong Yeol;Joo Jong Cheon
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.18 no.6
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    • pp.1762-1768
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    • 2004
  • The Korean formula medicine, Gami-Yukmi-Jihwang-Tang (GYJT) has been used for growing slowly, short of stature, incomplete development, fatigue, weak child, growing pain of child. However, it is still unclear how GYJT has an effect on experimental models. In the present study, the author investigated the immune-enhancing effect of GYJT. Forced swimming test (FST) was performed as a model of activity test in mice and measured blood urea nitrogen (BUN), aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactic dehydrogenase (LDH), glucose (Glc) and total protein (TP) in the serum. GYJT (1, 0.1 and 0.01 g/㎏) were orally administered to mice, once per day for 7 days using a feeding atraumatic needle. After 3 days, on FST, the immobility time was significantly decreased in the GYJT (0.01g/㎏/day)-fed group (120.75±5.71s) in comparison with the saline-fed group (153.80±10.74s). After 7 days, the immobility time was significantly decreased in the GYJT (0.1 and 0.01g/㎏/day)-fed group (125.67±5.36s and 107.67±3.71s) in comparison with the saline-fed group (167.67±12.99s). In addition, the contents of BUN and Glc in the blood serum were significantly decreased and the contents of AST, ALT and LDH were also decreased in the GYJT (1g/㎏/day)-fed group. However, the content of TP was not changed. The present results suggest that GYJT may be useful for the anti-fatigue and immune-enhancing agent. Also, the author investigated the effect of GYJT on the production of cytokines in human T-cell line, MOLT-4 cells. However, GYJT has not affected the production of IFN­γ, IL-2, IL-4. These results suggest that GYJT has immune-enhancing effect but does not affect T cell-mediated production of cytokines in the immune function improvement.

Color Contrast Evaluation Algorithm Considering Color Temperature Feeling (색 온도 느낌을 고려한 색 대비 평가 알고리즘)

  • Jang Young-Gun
    • The KIPS Transactions:PartB
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    • v.13B no.4 s.107
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    • pp.471-478
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    • 2006
  • In this paper, two color contrast evaluation algorithms, W3C and NSSC algorithms are compared and investigated to select proper criteria of the color contrast of text-background color combinations in web documents. The relationship between the color contrast defined by existing formula and the readability rating is not perfect and there is quite a bit of variance, in particular, there is some substantial outlier. I modify the NSSC algorithm to apply all colors and compare the two algorithms to apply same color combinations of web safe colors. A new algorithm considering color temperature feeling as a component of the color contrast is proposed and implemented. As the results of this study, the existing two algorithms are not contradictory to each other, 82% of all color combinations of web safe colors are not proper combinations according to W3C guide which provide severe restriction to select colors in web documents compared to NSSC algorithm. Experimental test shows proposed algorithm is superior to the W3C algorithm with respect to the linearity of relationship between color contrast and readability rating. It means a color temperature feeling is an effective component of a color contrast. But to determine best contribution ratio of the color temperature feeling, further study is required and it is related to Hangul font style and size. The more popular a mobile color display is used, the more important accessibility factor a color contrast will be.