• 한국식품과학회지
• /
• 제39권2호
• /
• pp.146-151
• /
• 2007

고식이섬유 쌀인 고아미 2호의 식품소재로서의 활용을 모색하고자 압출성형공정으로 고아미 후레이크를 제조한 다음 후레이크의 효소저항전분(RS) 함량, 페이스트 점도, 수분용해지수와 수분흡착지수, 체적밀도, 색도, 압착강도, 조직감 유지시간 등 품질 특성을 조사하였다. 압출성형 공정조건은 배럴온도 90, 110, $130^{\circ}C$ 그리고, 수분함량 50, 55%이었다. 압출성형 펠릿과 탈지한 후레이크의 RS함량은 각각 $8.00{\sim}8.56%$, $6.57{\sim}9.53%$ 범위로 수분함량이 50%에서 55%로 증가함에 따라 증가하는 경향을 나타내었다. 압출성형 펠릿과 탈지한 후레이크의 최고점도, 최저점도, 최종점도, 회복점도는 1시간 수침한 고아미에 비해 감소하는 경향을 나타내었고 구조파괴점도는 현저히 증가하는 경향을 나타내었다. 탈지한 후레이크의 수분용해지수와 수분흡착지수가 고아미 원료와 압출성형 펠릿보다 크게 증가하는 경향을 나타내었다. 압출성형 펠릿의 수분용해지수는 고아미 원료에 비해 감소하는 경향을 나타내었으며 수분흡착지수는 증가하는 경향을 나타내었다. 후레이크의 체적밀도는 $0.35{\sim}0.44$ g/mL 범위로 큰 차이를 나타내지 않았고 조직감 유지시간은 $12.4{\sim}19.4$분 범위로 시판 breakfast cereal들 보다 긴 유지시간을 나타내었다.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 1999년도 봄 학술발표회 논문집
• /
• pp.159-166
• /
• 1999

One of the most general methods that can evaluate the rippability is the seismic exploration. However, most field engineers have hardly used the seismic exploration. Instead of using the seismic exploration, they have usually used rock hammer and naked eyes to confirm the degree of rippability for soil, ripping rock and blasting rock. Therefore, to excavate the ground rationally, it is required to establish a quantitative criterion that can be used for distinguishing rippability. In this study, we find out the characteristics of rock strength through laboratory and field tests. The weathering condition of rock exposed to air due to excavation of soil layer and the variation of rock strength caused by weathering were investigated. A relationship between rock strength values that are obtained from uniaxial compression test, slaking durability test, point load test, schmidt hammer test and absorption ratio test is analyzed. The relationship is expressed in a form of equation by which we can evaluate the rock strengths obtained from simple laboratory and field tests. To evaluate rippability in a reasonable manner, a quantitative approach is proposed and a check list of rippability is developed based on the proposed methodology. It is recommended to modify the proposed method for evaluation of rippability in the field.

• 한국윤활학회:학술대회논문집
• /
• 한국윤활학회 2002년도 제35회 춘계학술대회
• /
• pp.169-176
• /
• 2002

Axial crushing behavior of cylindrical shell Is utilized in the braking of the high-velocity impacting object. In this paper, truncated cone shape brake device is introduced. That is, thickness of the shell is increased gradually from the impacting end to the other end. A detailed experimental investigation on the quasi-static axial crushing behavior of truncated cone type brake devices has been performed. Specimens of various shape were tested to check the influence of design parameters such as length, radius, mean thickness, and conical angle of cylinder. Influence of the material properties were also investigated by adopting aluminum, low carbon steel, and stainless steel as constructing materials. By analyzing deformation procedures of the specimens, it is seen that conical angle influence the deformation mode and the sequence of the wrinkles generation. Braking distance and mean braking force of each specimen were predicted based on the crushing load measured from the tests.

• 한국자동차공학회논문집
• /
• 제10권4호
• /
• pp.149-157
• /
• 2002

This paper is to investigate collapse mechanisms of CFRP(Carbon Fiber Reinforced Plastics)composite tubes and to evaluate collapse characteristics on the change of interlaiminar number and ply orientation angle of outer under static and impact axial compression loads. When a CFRP composite tube is crushed, static/impact energy is consumed by friction between the loading plate and the splayed fronds of the tube, by fracture of the fibers, matrix and their interface. These are associated with the energy absorption capability. In general, CFRP tube with 6 interlaminar number(C-type), absorbed more energy than other tubes(A, B, D-types). The maximum collapse load seemed to increase as the interlaminar number of such tubes increases. The collapse mode depended upon orientation angle of outer of CFRP tubes and loading status(static/impact). Typical collapse modes of CFRP tubes are wedge collapse mode, splaying collapse mode and fragmentation collapse mode. The wedge collapse mode was shown in case of CFRP tubes with 0° orientation angle of outer under static and impact loadings. The splaying collapse mode was shown in only case of CFRP tubes with 90°orientation angle of outer under static loadings, however in Impact tests those were collapsed in fragmentation mode .

• Computers and Concrete
• /
• 제14권2호
• /
• pp.193-209
• /
• 2014

Cyclic test of the columns is of practical relevance to the performance of compression members during an earthquake loading. The strength, ductility and energy absorption capabilities of reinforced concrete (RC) columns subjected to cyclic loading have been estimated by many researchers. These characteristics are not normally inherent in plain concrete but can be achieved by effectively confining columns through transverse reinforcement. An extensive experimental program, in which performance of four RC columns detailed according to provisions of ACI-318-08 was studied in contrast with that of four columns confined by a new proposed technique. This paper presents performance of columns reinforced by standard detailing and cast with 25 and 32 MPa concrete. The experimentally achieved load-displacement hysteresis and backbone curves of two columns are presented. The two approaches which work in conjunction with Response 2000 have been suggested to draw analytical back bone curves of RC columns. The experimental and analytical backbone curves are found in good agreement. This investigation gives a detail insight of the response of RC columns subjected to cyclic loads during their service life. The suggested analytical procedures will be available to the engineers involved in design to appraise the capacity of RC columns.

• Earthquakes and Structures
• /
• 제6권2호
• /
• pp.181-199
• /
• 2014

The infill walls, whose contribution to the earthquake resistance of a structure is generally ignored due to their limited lateral rigidities, constitute a part of the lateral load bearing system of an RC frame structure. A common method for improving the earthquake behavior of RC frame structures is increasing the contribution of the infill walls to the overall lateral rigidity by strengthening them through different techniques. The present study investigates the influence of externally bonded perforated steel plates on the load capacities, rigidities, and ductilities of hollow brick infill walls. For this purpose, a reference (unstrengthened) and twelve strengthened specimens were subjected to monotonic diagonal compression. The experiments indicated that the spacing of the bolts, connecting the plates to the wall, have a more profound effect on the behavior of a brick wall compared to the thickness of the strengthening plates. Furthermore, an increase in the plate thickness was shown to result in a considerable improvement in the behavior of the wall only if the plates are connected to the wall with closely-spaced bolts. This strengthening technique was found to increase the energy absorption capacities of the walls between 4 and 14 times the capacity of the reference wall. The strengthened walls reached ultimate loads 30-160% greater than the reference wall and all strengthened walls remained intact till the end of the test.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2014년도 춘계 학술논문 발표대회
• /
• pp.240-241
• /
• 2014

The environmental pollution problem the globally related to global warming arises. In the construction industry the cement mostly use material, generates the great quantity of CO₂ among the fired process and the global warming is more aggravated. In addition, the polysilicon that is the main raw material used in the solar power generation, produces 1 ton and the industrial by-product of 2 tons is generated. In this way, the arising sludge there is not method recycling and it is all discarded. Therefore, in this research, try to present as the fundamental research material for using the polysilicon sludge as the admixture of the cement in order to reduce the amount of the cement. The based on 'KS L ISO 679' was progressed mortar test. the liquidity, air flow rate, setting time, water absorption ratio, flexural and compression strength was measured. According to, appropriate replacement ratio of the polysilicon sludge tries to analyze.

• 한국전기전자재료학회논문지
• /
• 제15권7호
• /
• pp.627-633
• /
• 2002

Many isolated featureless domains were explicitly observed even at the air-water interface. We measured the surface pressure shift originating from the photo-isomerization of azobenzene units on the periphery of dendrimers. The maximum surface pressure was gradual1y increased and saturated by cyclic compression and decompression. By irradiation of 365 [nm] light, the surface pressure was increased, which was originated by the photo-isomerization process of the azobenzene group on the periphery from trans to cia form. The increase of the dipole moment ($\mu$), which may increase the interaction among Azo dendrimer molecules, made an important role on surface pressure shift. From the absorbance spectrum by UV irradiation and heat treatment, we can see that the absorbance in the UV region decreases with the increase of the UV irradiation time, but the peak at 350 m, characteristic of dendrimers in the LB monolayers, was not shifted until four irradiation cycles. This suggests that optical behavior and morphological change are affected by the functional group and the symmetric chain.

• 한국주조공학회지
• /
• 제30권1호
• /
• pp.22-28
• /
• 2010

Metal foam is a porous or cellular structure material and representative property is a very high porosity. Foamed materials have very special properties such as sound, vibration, energy and impact absorption capacity. Especially this properties are widely used for safety demands of architecture, auto and aircraft industry. But metal foam need to increased its compression strength and hardness. This study were researched about Al-Si alloy foams with variation amount of Si contents for their fabrication and properties such as porosity, cell structure, microstructure and mechanical properties. The result are that the range of pore size is 2~4 $mm{\phi}$, the high porosity are 88%, high yield strength is 1.8MPa, the strain ratio is 60~70% and vickers hardness is 33.1~50.6.

• 대한기계학회논문집A
• /
• 제27권10호
• /
• pp.1686-1694
• /
• 2003

The foam-filled tube beams can be used for the front rail and firewall structures to absorb impact energy during frontal or side collision of vehicles. In the case of side collision where bending is involved in the crushing mechanism, the foam filler would be effective in maintaining progressive crushing of the thin-walled structures so that much impact energy could be absorbed. In this study, bending behaviors of the closed-cell-aluminum-alloy-foam-filled stainless steel tube were investigated. The various foam-filled specimens including piecewise fillers were prepared and tested. The aluminum-alloy-foam filling offered the significant increase of bending resistance. Their suppression of the inward fold formation at the compression flange as well as the multiple propagating folds led to the increase of load carrying capacity of specimens. Moreover, the piecewise foams would provide the easier way to fill the thin-walled shell structures without the drawback of strength.