• Title/Summary/Keyword: strength variation

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Evaluation of Tailorability of Adhesive Fabrics for Men's Suit (신사복의 접착포에 대한 형태 안정성 평가)

  • Kim, Jung-Sook
    • Fashion & Textile Research Journal
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    • v.8 no.5
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    • pp.585-590
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    • 2006
  • In the variation of physical properties of adhesive fabrics, the objective of this study is to analyze fitness of fusible interlining to four sorts of fabrics for men's suit with various structural parameters. Four fusible interlinings are used for adhering to fabrics for men's suit. Mechanical properties of these 16 adhesive fabrics fused with these interlinings are measured by KES-FB system for analysing appearance and wearing properties of garments and for examining the fitness of fusible interlining to the fabrics for men's suit. The variation of bending property for adhesive fabrics are found to be higher in the order of interlining 1(Cotton30/Rayon70, plain), interlining 2(Polyester30/Rayon70, warp knit), interlining 4(Polyester, shingosen fabrics with drawing textured yarn) and interlining 3(Polyester, double dot coating interlining). The variation of adhesive effect shows the same results with bending property and shows negative relation with extensibility in weft direction per extensibility in warp direction(EM2/EM1). The variation of peel strength of adhesive fabrics, woolen fabrics in the case of face fabrics and interlining 3 in the case of interlining shows the largest value respectively.

Variation of Soil Properties by Permeating Injection of Chemical Grouts (약액(藥液)의 침투주입(浸透注入)에 의한 토질성상변화(土質性狀變化))

  • Chun, Byung Sik
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.2 no.4
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    • pp.1-9
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    • 1982
  • Variation of soil properties is studied by permeating injection of chemical grouts, such as cement type, water-glass type and acrylamide type, to the same soil samples with different densities. Moreover, injection tests using specially prepared equipments of 1.0 shot system and 1. 5 shot system are attempted to investigate permeating injection effects in highly compacted soil and in the presence of ground water. The main factor which causes the improvement of cut-off effect and shearing strength is the cohesion of soil. The strength in the loose state is fundamentally governed by the membrane cohesion, meanwhile, in the loose state is governed by the structural cohesion. Injection effects under the ground water flow is considerably decreased, and effective gelling ratio of approximate 45~80% is observed by variation of velocity and gel time, besides grading of injection materials has high relation with permeation and traveling length but has little relation with effective gelling ratio. Permeating injection effects, such as gelling scope, gelling strength in highly compaoted soil conditions can be confirmed by penetration resistance diagram and iso-strength curve.

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A Study on Bending Fatigue Strength of One Side Fillet Welded T-Joint by SM 490A steel (Sm 490A강으로 제작된 T형 편면용접이음재의 굽힘피로강동에 관한 연구)

  • 엄동석;강성원;이태훈;이해우;조수형
    • Journal of Welding and Joining
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    • v.16 no.5
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    • pp.134-141
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    • 1998
  • In this study, a fillet size for bending fatigue strength of one side fillet welded T-joint, used in box type girder and other welding structure, was investigated by bending fatigue test with or without edge preparation and burn through, with variation of joint shape. As a result, the following conclusions were obtained. (1) In one side fillet welded T-joint, the larger the leg length, the greater the bending fatigue strength. The increase in bending fatigue strength. (2) One side filet welded T-joint with edge preparation showed higher bending fatigue strength than that with twofold-large leg length and without edge preparation. (3) In one side fillet welded T-joint without edge preparation, both manual welding and automatic welding were carried out with same condition. In this case, automatic welding shoed deeper penetration and more increased horizontal leg length than manual welding, so that automatic welding offers grater bending fatigue strength. (4) For one side fillet welded T-joint without edge preparation, the ratio(h/t) of the leg length (h) and the main plate thickness (t) in which toe crack can occur was 1.2 over. (5) In one side fillet welded T-joint with edge preparation, the burn through led to reduced bending fatigue strength. However, this bending fatigue strength was higher than that of one side fillet welded T-joint without edge preparation and with a larger leg length.

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Reinfocing Effects Using Model Geocell in Sand (모래지반에서 모형 지오셀에 의한 보강 효과)

  • Yoon, Yeo Won;Kim, Poong Sik;Chun, Sung Han
    • Journal of the Korean GEO-environmental Society
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    • v.4 no.3
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    • pp.51-59
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    • 2003
  • Loading tests were carried out for model geocell to study the reinforcing effect by variation of tensile strength, cell height, soil density and embedded depth of geocell. From the result, it could be seen that the ultimate bearing capacity of the geocell system was influenced rather by the connection strength than by the tensile strength of geocell material. Bearing capacity increased with the increase of height to width ratio of geocell for the same relative density, strength and embedded depth. And the bearing capacity ratio(BCR) was higher at low relative density of sand than that of high relative density. The increase of bearing capacity was higher at geocell with high tensile strength than that of low tensile strength. And the influence was clear at higher relative density. Also the BCR was higher at shallow embedded depth of geocell. Without consideration of tensile strength of material, the application of bearing capacity formula suggested by Koerner seems not suitable for the special case with low tensile strength of geocell material.

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Experimental Evaluation of Shear Strength of Surface Soil Beneath Greenhouse Varying Compaction Rate (비닐하우스 기초 토양의 다짐률 변화에 따른 전단강도 특성)

  • Lim, Seongyoonc;Heo, Giseok;Kwak, Dongyoup
    • Journal of The Korean Society of Agricultural Engineers
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    • v.63 no.6
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    • pp.17-26
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    • 2021
  • Greenhouses have been damaged due to the uplift pressure from strong wind, for which rebar piles are often installed near the greenhouse to resist the pressure. For the effective design of rebar piles, it is necessary to access the shear strength of soil on which the greenhouse is constructed. This study experimentally evaluates the shear strength of the soil beneath the greenhouse. Four soil samples were collected from four agricultural sites, and prepared for testing with 75, 80, 85, and 90% compaction rates. One-dimensional unconfined compression test (UC), consolidated-undrained triaxial test (CU), and resonant column test (RC) were performed for the evaluation of shear strength and shear modulus. Generally, the higher shear strength and modulus were observed with the higher compaction rates. In particular, the UC shear strength increases with the increase of #200 sieve passing rate. Resulting from the CU test, the sample with the most of coarse soil had the highest friction angle, but the variation is small among samples. Resulting from the CU and RC tests, the ratio of maximum shear modulus with the major principle stress at failure was the higher at the finer soil. The ratio was two to three times greater than the ratio from the standard sand. This indicates that the shear strength is lower for the fine soil than the coarse soil at the same shear modulus. The results of this study will be a useful resource for the estimation of the pull-out strength of the rebar pile against the uplift pressure.

A Study on the Quality Deviation of High-Strength Concrete from Multiple Ready Mixed Concrete Companies (다수 레미콘사에서 납품된 콘크리트 품질 편차에 관한 연구)

  • Park, Dong-Cheon;Seok, Won-Kyun;Jeon, Hyun-Soo;Kim, Young-Sun
    • Journal of the Korea Institute of Building Construction
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    • v.22 no.6
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    • pp.577-583
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    • 2022
  • On large-scale sites, concrete is often delivered from a number of ready-mixed concrete companies, but even if the same concrete mixture table is used, it is thought that there will be a difference in quality due to differences in materials and manufacturing equipment. Due to a lack of previous research in this area, this study measured the properties of fresh concrete, compressive strength, and chlorine ion diffusion coefficient using the concrete supplied by 12 ready-mixed companies in Busan. The fresh concrete properties met the criteria. The compressive strength increased by 137% for 30MPa, 131% for 45MPa, and 117% for 80MPa by specified compressive strength. For the chlorine ion diffusion coefficient, the average value for each specified compressive strength could be derived without significant variation. The higher the compressive strength, the greater the deviation , and the lower the compressive strength, the greater the deviation in the chlorine ion diffusion coefficient.

Evaluation on Strength Characteristics of Reactive Materials to Prevent the Diffusion of Organic Pollutants (유기오염물 차단을 위한 반응재료의 강도 특성 평가)

  • Jai-Young Lee;Seung-Jin Oh;Su-Hee Kim;Kicheol Lee;Jeong-Jun Park;Gigwon Hong
    • Journal of the Korean Geosynthetics Society
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    • v.22 no.4
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    • pp.35-42
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    • 2023
  • This paper described the strength variation characteristics to evaluate the applicability of a reactive material that can absorb organic pollutants as an underground barrier. The Strength was evaluated by unconfined compression test. The test results showed that the strength of the reactive material according to the absorption of each pollutant was in the order of water > TCE > TPH. However, the strength of the reactive material absorbing TPH was greater than that of the case absorbing TCE, when the composition ratio of polynorbornene was 12% or less. The strength of the reaction material in contact with water continued to decrease as the polynorbornene composition ratio decreased. The strength of the reaction material in contact with TCE and TPH increased as the polynorbornene composition ratio decreased from 30% to 21%, and then decreased. In other words, the optimal composition ratio of the reactive material should be applied considering the strength due to contact with pollutants according to the stress conditions occurring in the ground.

Mechanical Properties of Very Rapid Hardening Polymer Mortar for Concrete Repair (보수용 초속경 폴리머 모르타르의 역학적 특성)

  • Hong, Kinam;Shin, Junsu;Han, Sanghoon;Seo, Dongwoo;Ahn, Kwangkuk
    • Journal of the Korean GEO-environmental Society
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    • v.15 no.8
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    • pp.31-37
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    • 2014
  • In this study, mechanical properties of Very-Rapid Hardening Polymer (VRHP) mortar were investigated. To do it, 75 VRHP mortar specimens were tested by the compressive test, bending test, bonding test, freezing and thawing test, length variation test, and water absorption test. From the test results, it was confirmed that the bond strength of VRHP was higher than that of normal concrete by 50 %, and the resistance of freezing and thawing of VRHP was more excellent than normal concrete. In addition, length variation ratio and water absorption ratio of VRHP were smaller than those of normal concrete by 20 %. Therefore, It should be mentioned that VRHP can be successfully used as the material for repairing the crack of concrete structure.

A Study on Shear Characteristics of a Rock Discontinuity under Various Thermal, Hydraulic and Mechanical Conditions (다양한 열-수리-역학적 조건 하에서 불연속면 전단 거동 특성에 관한 실험적 연구)

  • Kim, Taehyun;Jeon, Seokwon
    • Tunnel and Underground Space
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    • v.26 no.2
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    • pp.68-86
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    • 2016
  • Understanding the frictional properties of rock discontinuities is crucial to ensure the stability of underground structures. In particular, the frictional behavior at depth depends on the complex interaction among mechanical, hydraulic, thermal and chemical characteristics and their coupled effects. In this study, a series of shear tests were carried out in a triaxial compression chamber to investigate the shearing behavior of saw-cut granite surface and rough shear surface of synthetic rocks. The test results were analyzed using Coulomb's shear strength criterion. The frictional behavior of saw-cut granite surface showed little variation at different confining, water pressures and temperature conditions, however in case of synthetic rocks, the frictional behavior showed different trend depending on normal stress level. In addition, the variation of stiffness and dilation at different testing conditions were analyzed, and the stiffness and dilation showed little variation at different water pressures and temperature conditions.

Reduction of the Offensive Odor from Confectionery Wastewater Plant (제과공장의 폐수처리장에서 발생하는 악취 저감)

  • 김영식;손병현;조상원;정종현
    • Journal of Environmental Health Sciences
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    • v.24 no.1
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    • pp.62-69
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    • 1998
  • It has been studied that the measurement of odor component emission at confectionery manufacture. The objects of this study were to investigate reduction of offensive odor. The survey effects of odorous materials are presented as follows. The countermeasure of operating process is to minimize sludge sediment in each unit facility. Especially, in summer, we have to clean the sludge frequently, because anaerobic decomposing is likely to occur easily. The sludge or scum from sedimentation tank pond, and floating tank should be treated quickly. We should avoid overloading operation. In the case of overloading, dissolved oxygen should be increased, the quality of wastewater input should be decreased. When dried cakes from condense tank or floating tank are left in treatment plant, we should cover, to prevent diffusion of smell with masking materials. The seasonal condition of operating should be fixed and the kind of coagulants should be changed because the wastewater in each season have different loading rates and organic materials. Odorous materials are very sensitive to the seasonal temperature variation. Especially, when the amount of rainfall is small and the high temperature of maintenance in long periods, air diffusion rate is large, so odorous materials can make great effect on surroundings comparision with other periods. To reduce odorous gas, as short term method, we had better take ceramic addition method. Especially, in summer we should take ceramic addition method. Also, as long term method, the size of wastewater treatment facility is the most important in the normal operating of wastewater treatment facility. But wastewater treatment facilities in this factory are too old, treatment process is old fashion, and the size is too small. So, large wastewater quantity to treat in summer. As results, the expansion of wastewater treatment facility and the process of improvement are required. Restriction level of odor was exceed. As it is overloaded in summer, the basis cause of odor is that the size of wastewater treatment facility is small. The prediction of air quality equilibrium density variation show that the odorous materials from working place are Amine materials whose smell strength is about 2.5(a little strong degree). We can suppose that in summer is sensitive to temperature variation, smell strength is larger as to reduce the origin of odor. We must expand wastewater treatment facility and improve the process A.S.A.P.

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