• Title/Summary/Keyword: shear effect

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Behavioral Characteristics of Decomposed Residual Solis (다짐 풍화잔적토의 거동특성 연구)

  • Lee, In-Mo;Lee, Seung-Cheol;Kim, Yong-Jin
    • Geotechnical Engineering
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    • v.12 no.6
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    • pp.115-126
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    • 1996
  • The purpose of 1,his study is to analyze the compression and strength charactefistics of the decomposed -weathered soil originating from biotite gneiss or fine grained gneiss sampled from Poidong, Seoul : to figure out the behavioural characteristics of the decomposed -weathered soil in accordance with mineral composition and origin by comparing experimental results of residual soils. originating from granites and sampled from Bulam, Andong and Kimchun area. A series of CIU, CID CKoV, CKoD tests were car lied out. Although weathered soils have different origin and mineral composition, the slope of the NCL A was similar. It was also shown that plastic strain ratio was about 85% mainly due to the particle crushing effect during compression. The Poidong soil showed strain softening phenomenon unlike the Kimchun and Andong soils. this implies that the behavioural characteristics are affected by the origin and the mineral composition of the soil particles. Moreover, it was found that the angle of the shear resistance$(\phi')$ was dependent on the mineral composition. On the oher hand, measured Af values of decomposed weathered soils were more than one regardless of the origin and the mineral composition.

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Passive Control of the Supersonic Cavity Pressure Oscillations Using Porous Vertical Barrier (수직 다공벽을 이용한 초음속 공동 압력진동의 피동제어)

  • Kang, Min-Sung;Kwon, Joon-Kyeong;Kim, Heuy-Dong;Setoguchi, Toshiaki
    • Journal of the Korean Society of Propulsion Engineers
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    • v.13 no.3
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    • pp.27-33
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    • 2009
  • A computational study has been performed out to evaluate the effect of a vertical porous barrier on the pressure oscillations in a supersonic cavity. The porous barriers with different perforations were vertically installed into a rectangular cavity at Mach numbers 1.50, 1.83 and 2.50. TVD finite difference MUSCL scheme was employed to solve the two-dimensional, unsteady, compressible Navier-Stokes equations. The present vertical porous barrier considerably altered the characteristics of the time-dependent shear layers that occur at the upstream edge of cavity and remarkably reduced the pressure oscillations inside the supersonic cavity. The present results showed that the effectiveness of passive control using the present porous vertical barrier is dependent on Mach number and the perforation of the porous barrier.

Seismic assessment of transfer plate high rise buildings

  • Su, R.K.L.;Chandler, A.M.;Li, J.H.;Lam, N.T.K.
    • Structural Engineering and Mechanics
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    • v.14 no.3
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    • pp.287-306
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    • 2002
  • The assessment of structural performance of transfer structures under potential seismic actions is presented. Various seismic assessment methodologies are used, with particular emphasis on the accurate modelling of the higher mode effects and the potential development of a soft storey effect in the mega-columns below the transfer plate (TP) level. Those methods include response spectrum analysis (RSA), manual calculation, pushover analysis (POA) and equivalent static load analysis (ESA). The capabilities and limitations of each method are highlighted. The paper aims, firstly, to determine the appropriate seismic assessment methodology for transfer structures using these different approaches, all of which can be undertaken with the resources generally available in a design office. Secondly, the paper highlights and discusses factors influencing the response behaviour of transfer structures, and finally provides a general indication of their seismic vulnerability. The representative Hong Kong building considered in this paper utilises a structural system with coupled shear walls and moment resisting portal-frames, above and below the TP, respectively. By adopting the wind load profile stipulated in the Code of Practice on Wind Effects: Hong Kong-1983, all the structural members are sized and detailed according to the British Standards BS8110 and the current local practices. The seismic displacement demand for the structure, when built on either rock or deep soil sites, was determined in a companion paper. The lateral load-displacement characteristic of the building, determined herein from manual calculation, has indicated that the poor ductility (brittle nature) of the mega-columns, due mainly to the high level of axial pre-compression as found from the analysis, cannot be effectively alleviated solely by increasing the quantity of confinement stirrups. The interstorey drift demands at lower and upper zones caused by seismic actions are found to be substantially higher than those arising from wind loads. The mega-columns supporting the TP and the coupling beams at higher zones are identified to be the most vulnerable components under seismic actions.

Effects of Humectant and Roasting on Physicochemical and Sensory Properties of Jerky Made from Spent Hen Meat

  • Sorapukdee, Supaluk;Uesakulrungrueng, Chanpen;Pilasombut, Komkhae
    • Food Science of Animal Resources
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    • v.36 no.3
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    • pp.326-334
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    • 2016
  • This study was carried out to develop jerky product utilizing spent hen meat. Manipulation of water activity (aw) of semi-dried meat with the addition of humectants (glycerol and sorbitol at the concentration of 0, 10, and 15%) and roasting process were applied to enhance quality of jerky product. After spent hen meat was ground, formulated, reformed and then dried in convection oven at 85℃ for 2 h followed by 60℃ for 1 h, all jerky samples showed values of aw ≤0.85 with total aerobic bacteria, yeast and mold and Staphylococcus aureus counts were reduced to undetectable levels. Moreover, the results showed that the 15% glycerol added jerky showed superior quality, indicated by the lowest aw, low protein aggregation as evaluated by sorption isotherm and the lowest shear value as compared to sorbitol added and control samples (p<0.05). Regardless effect of humectant, roasting could improve the quality of the jerky via enhanced sensory attributes by increasing color, appearance, flavor and overall acceptability scores (p<0.05). Therefore, spent hen meat could be used as a potential raw material for jerky in which soft product texture obtained by the addition of glycerol and intense flavor resulted from roasting process after drying, leading to sensory acceptance.

Effects of Whey Powder Supplementation on Dry-Aged Meat Quality

  • Kim, Ji-Han;Yeon, Su-Jung;Hong, Go-Eun;Park, Woojoon;Lee, Chi-Ho
    • Food Science of Animal Resources
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    • v.36 no.3
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    • pp.397-404
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    • 2016
  • The objective of this study was to determine the effect of dietary supplementation with whey powder (WP, 1g/kg feed) from weaning to slaughter (150 d) on dry-aged loin quality of pigs. Fifty-eight pigs were randomly divided into two dietary treatment groups (seven replications of four pigs per treatments). Basal diet with 0.1% whey powder was supplied to the WP group. Basal diet was used for the control group (CON). Diet whey protein did not appear to influence the moisture or protein contents. However, ash and fat contents were significantly (p<0.05) decreased in the WP group compared to the control group. Drip loss was significantly (p<0.05) lower in the WP group than that of the control group. Increasing redness with decreasing lightness was found in the inner loin of the WP group. Calcium and iron contents in the WP group were significantly higher than those in the control group. Protein degradation was higher in the WP group than that in the control group (p<0.05), whereas shear force was lower in the WP group than that in the control group (p<0.05). In conclusion, the basal diet supplemented with 0.1% whey powder influence negatively the lipid oxidation of meat whereas the texture property and mineral composition of meat from whey powder fed pigs are developed.

Effect of Electro-Osmosis Method on Marine Clay with Preloading (선행하중이 작용하는 해성점토지반에 전기삼투공법의 효과)

  • Kang, Hongsig;Ahn, Kwangkuk
    • Journal of the Korean GEO-environmental Society
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    • v.16 no.2
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    • pp.53-58
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    • 2015
  • The Pre-loading method has been widely used for the soft ground stabilization but long construction times and the transport of large quantities of fill material are required. To shorten the construction periods, the vertical drain method is generally applied simultaneously. But the high costs of the fill materials along with environmental damages remain as the main difficulties to apply this method. Therefore, a complimentary way to reduce both the height of the embankment and the consolidation time is needed. In this study, the electro-osmosis method, which is able to shorten the consolidation time and minimize the damage of the environment, was performed with a model test. The results show that as the voltage increases the consolidation settlements, consolidation drainage and shear strength also increase while the water content decreases.

Flexural Strengthening of Reinforced Concrete Beams Using Carbon Fiber Mesh (탄소섬유 메쉬를 사용한 철근콘크리트 보의 휨보강)

  • Seo, Soo-Yeon;Yun, Hyun-Do;Choi, Chang-Sik;Choi, Ki-Bong
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.9 no.2
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    • pp.181-190
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    • 2005
  • The objective of this work is to study the flexural strengthening effectiveness of Carbon Fiber Mesh (CFM) in reinforced concrete beams. Flexural strengthening for a simply supported reinforced concrete (RC) beam using CFM is developed by bonding CFM to the soffit of the beam. In this experimental program, five medium-sized reinforced concrete beams strengthened with CFM are tested in bending to evaluate reinforcing effects of the CFM. The beams are designed to have high shear capacity so that expected dominant failure mode of specimens is bending. The reinforcing effect of CFM is small at crack initiation, but is considerable in flexural rigidity of the beam after crack initiation. In comparing the behaviors of strengthened and virgin beams each other, it is shown that the strength of RC beams can be enhanced by attaching CFM. A fairly good agreement between the measured values and the calculated ones is obtained at both the cracking strength and yield strength of the strengthened beams.

An Experimental Study on the Structural Performance of Lightly Reinforced Concrete Frame Retrofitted with Concrete Block and Cast-In Place Infilled Wall (블록 끼움벽과 현장타설 끼움벽으로 보강된 비내진 상세 철근콘크리트 골조의 구조성능에 관한 실험적 연구)

  • Choi, Chang-Sik;Lee, Hye-Yeon;Kim, Sun-Woo;Yun, Hyun-Do
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.9 no.2
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    • pp.199-206
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    • 2005
  • In many other countries framed structures with inadequate lateral strength and stiffness have been strengthened by providing reinforced concrete infilled wall. There is a general agreement among researchers those infilled walls have 3-5times greater lateral strength compared with bare frame. The main objective of this research is to investigate the behavior and strength of reinforced concrete frames infilled with concrete block and cast-in-place reinforced concrete panels used for strengthening the structure against seismic action. For this purpose three 1/3 scale, one-bay, one-story reinforced concrete infilled frames were tested under reversed cyclic loading simulating the seismic effect. The results indicate that infilled walls increase both strength and stiffness significantly under lateral loads. Especially Strength capacity and initial stiffness of CIP infilled wall increased 3.8 times and 6.6 times higher than lightly reinforced concrete frame.

Effect of Curing Time on the Physicochemical and Sensory Properties of Beef Jerky Replaced Salt with Soy Sauce, Red Pepper Paste and Soybean Paste

  • Lim, H.J.;Kim, G.D.;Jung, E.Y.;Seo, H.W.;Joo, S.T.;Jin, S.K.;Yang, H.S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.27 no.8
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    • pp.1174-1180
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    • 2014
  • This study was done to investigate the quality properties of beef jerky with soy sauce, red pepper paste, and soybean paste replacing salt. Sliced beef samples were cured in salt (control), soy sauce, red pepper paste, and soybean paste for 24 or 48 h and then dried at $70^{\circ}C$ for 8 h. Treatments showed higher final moisture content and lower $Na^+$ concentration than the control after drying for 8 h. The lightness and shear force values were lower in all treatment samples than in the control during 48 h of curing time. In particular, lower lipid oxidation was found in the jerky cured with red pepper paste than in the control. Sensory evaluation showed that color, flavor, and tenderness of jerky samples were improved by replacing salt with soy sauce, red pepper paste and soybean paste, and higher likeability scores of the beef jerky were obtained among those treatments after 48 h of curing time.

The Properties of Yellow Layer Cakes Made by Different Substituting Levels of Waxy Maize Starch for Shortening (Waxy Maize Starch의 대체율을 달리하여 제조한 옐로우 레이어 케이크의 특성)

  • 송은승;강명화
    • Journal of the East Asian Society of Dietary Life
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    • v.14 no.1
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    • pp.39-46
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    • 2004
  • Waxy maize starches are inherently stable in soluble status and can be chemically modified to improve stability along with heat, acid and shear resistance. This study was carried out to investigate the effect of theological and sensory characteristics of the yellow layer cake made by adding different levels of waxy maize starch as a fat substitute for shortening. By increasing the substitution level of waxy maize starch for shortening, the specific gravity of cake batter increased and the viscosity decreased. The microstructures of cake crumb observed by the scanning electron microscope were not different significantly, and the size of air cells and fat particles also were not substantially decreased by increasing fat substitution level. The texture profile analysis using texture analyzer decreased by increasing the different substituting levels of waxy maize starch. Among various sensory properties, the color value of layer cake increased by increasing the level of waxy maize starch. However, the appearance, flavor, taste, texture and overall preference decreased.

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