• 한국지하수토양환경학회지:지하수토양환경
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• 제18권7호
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• pp.54-62
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• 2013

Fine suspended solids and soluble heavy metals generated from mine drainage could destroy environment as the aesthetic landscapes, and depreciate water quality. Therefore, this research is focused on process development applied the actual field for controlling fine suspended solids and heavy metals, and so that bench-scale tests were performed for field application based on advanced researches. The field of mine drainage in this research was in H mine located Taebaek-si, Gangwon-do. The inclination plates were mounted 2 kinds of arrangement (octagon and radial types) in circle type settling basin. The inclination plates could be helped to settle of suspended solids; decreased 34% of suspended solids and 50% of turbidity in effluent. Radial type of inclination plates showed the results that is more efficient to settle of suspended solids (average to 3.45 mg/L) compared to octagon type. In the experiments to decrease retention time of mine drainage in settling basin from 6 hrs to 1.5 hrs, suspended solid concentration was exceeded to 30 mg/L as the standard for suspended solid at 10 days after the operation under tha retention time of 3hrs and 1.5hrs. In the tests for filtration, granular activated carbons were indicated the better effective to filtering and absorption of fine suspended solid and soluble heavy metals than anthracite.

• 한국태양에너지학회 논문집
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• 제25권4호
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• pp.133-139
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• 2005

In this paper, the ventilation performance of suspended particulates in indoor side was investigated by step-down method. Experiments were performed in function of mechanical ventilation types and locations of supply and extract air. The type 2 ventilation system shows the highest removal characteristics rather than other 2 types. It means that the displacement ventilation has also good decay rates of concentration compared to mixing ventilation.

• Structural Engineering and Mechanics
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• 제64권5호
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• pp.611-620
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• 2017

A new theory of weightless sagging planer elasto-flexible cables under point loads is developed earlier by the authors and used for predicting the nonlinear dynamic response of cable-suspended linear elastic beams. However, this theory is not valid for nonlinear elastic cracked concrete beams possessing different positive and negative flexural rigidity. In the present paper, the flexural response of simply supported cracked concrete beams suspended from cables by two hangers is presented. Following a procedure established earlier, rate-type constitutive equations and third order nonlinear differential equations of motion for the structures undergoing small elastic displacements are derived. Upon general quasi-static loading, negative nodal forces, moments and support reactions may be introduced in the cable-suspended concrete beams and linear modal frequencies may abruptly change. Subharmonic resonances are predicted under harmonic loading. Uncoupling of the nodal response is proposed as a more general criterion of crossover phenomenon. Significance of the bilinearity ratio of the concrete beam and elasto-configurational displacements of the cable for the structural response is brought out. The relevance of the proposed theory for the analysis and the design of the cable-suspended bridges is critically evaluated.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제50권6호
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• pp.303-306
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• 2001

STFR were fabricated on the floating membrane which was formed by SOI-micromachining process. The floating membranes having a thickness range of $3{\sim}15{\mu}m$ could be simply formed by micromachining the directly-bonded and thinned SOI substrate. The STFR device fabricated on the $15{\mu}m$-thick membrane showed resonance frequency of fr = 1.65 GHz, coupling coefficient of Keff2 = 2.4 %, and series and parallel quality factors of Qs = 91.7 and Qp = 87.7, respectively.

• 한국안전학회지
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• 제32권6호
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• pp.61-67
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• 2017

Suspended sediment transport plays principal roles in morphological process of natural coastals. It is needed to understand the reason why interaction characteristics of solitary wave and suspended sediment. The present study shows that suspended sediment pickup derived on solitary wave celerity. The 2D prismatic open channel length is 12 m, width is 0.8 m, height is 0.75 m and slope is 1/6. Generation of solitary wave is used by rapidly opening the sluice gate. Bottom surface sediments are laid movable slope section by 0.03 m thickness and experimental sediments are used anathracite and jumoonjin sand. Techniques of suspended sediment pickup rate are designed equipment ASC(Absorptive Suspended sediment Collector). It could directly absorb 5 points suspended sediment by channel water depth. Solitary wave celerity is measued by ADV(Acoustic Doppler Velocimeter). Mounted two video cameras(Model No. : Sony, HDR-XR550) are used to image processing of suspended sediment concentration and turbidity. Suspended sediment pikcup rate(Einstein, 1950) is analyzed to nondimensionalization based on solitary wave celerity. The suspended sediment pickup rate is suggested that more effective plunging breaking type than spilling. The results indicates fundamental suspended sediment transport mechanism between solitary wave celerity and suspended sediment pickup based on laboratory experiments. Finally, the present study suggests that suspended sediment pickup rate by solitary wave is used only characteristics of sediment and solitary wave celerity.

• 대한간호학회지
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• 제26권2호
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• pp.271-280
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• 1996

The purpose of this study was to determine the effect of periodic walking during hindlimb suspension on the mass, relative weight, fiber type distribution and cross-sectional area of Type I and II fibers in the developing Type II plantaris muscle. To examine the effectiveness of periodic walking on mass and fiber size, the hindlimbs of young female Wistar rats were suspended (HS group) and half of these rats walked on a treadmill for 45 min／day(15 min every 4 hours) at 5 meters／min at a 15 degree grade(HS-W group) After seven days of hindlimb suspension, the plantaris muscle wet weight was 28.40％ significantly smaller（P＜0.005） and relative plantaris muscle weight was 26.97％ smaller compared with those of control rats（P＜0.05）. The plantaris muscle wet weight and the relative plantaris muscle weight increased by 46.60％ and 49.23％ respectively with periodic walking, moreover. the plantaris muscle wet weight and the relative plantaris muscle weight of the HS-W rats recovered to the level of the control rats. No change was observed in fiber type percentage of the developing plantaris muscle following one week of hindlimb suspension or periodic walking during hindlimb suspension. Type I and II fiber cross-sectional areas of the developing plantaris muscle were 42.51％ and 43. 68％ lower in the HS group than in the control group（p＜0.0001）, Type I and II fiber cross-sectional areas of the developing plantaris were 30.82％ and 45.97％ greater in the HS-W group than in the HS group（p＜0.0001）, whereas Type I and II fiber cross-sectional area of HS-W group were less than those of the control group（P＜0.0001） The results suggest that periodic walking can attenuate developing plantaris muscle atrophy induced by hindlimb suspension.

• 대한건축학회논문집:구조계
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• 제35권10호
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• pp.171-180
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• 2019

In Korea, the seismic design of non-structural elements was interested by Earthquake of the 2016 Gyeong-ju and 2017 Po-hang. Among the non-structural elements, the ceiling system with steel panel used in Po-hang station showed failure examples of non-seismic design ceiling. In this study, the seismic performance of suspended ceiling with steel-panel, such as those used in Po-hang Station, was evaluated by shaking table tests. The shaking table tests were performed in accordance with the ICC-ES AC156 standard with floor acceleration being applied horizontally in one direction using a $3.3{\times}3.3m^2$ frame. The ceiling system consists of steel-panels, carrying channels, main and cross T-bars, and anti-falling clips. The anti-falling clip prevents the steel panel falling completely. The shaking table test confirmed that the damage at the previous stage had a direct impact on the damage state at the next stage. Through the shaking table test, the damage state of the T-bar type steel-panel suspended ceiling system was defined.

• 한국해양학회지
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• 제30권3호
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• pp.147-162
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• 1995

큰 潮差 지역인 금강 鹽河口의 潮流과 江水流入에 의한 순환과 이에 따른 부유물질의 이동을 알아보기 위해 1990년부터 1992년까지 세 정점에서 潮流 및 浮游퇴적물질 농도를 관측하였다. 이 염하구의 가장 외해쪽 관측점에서는 漲潮流 와 落潮流의 수직 구조는 거의 대칭형을 나타내고 있다. 또, 남측 수로에서는 漲 潮流가 全水層을 통해서 우세하나 북측 수로에서는 상층과 저층에서는 落潮流가 우세하고 중층에서는 漲潮流가 우세하였다. 남측 수로에서의 최대유속은 漲潮流 시에 중층에서 174 cm/s이었으며, 북측 수로의 최대 유속도 漲潮流시 중층에서 148 cm/s로 기록되었다. 반면에 표층과 저층에서는 최대유속 110.6 cm/s의 강한 유속이 落潮時에, 92.1 cm/s이 漲潮시에 각각 기록되었다. Hansen and Rattray 의 scheme에 의하면 금강 鹽河口는 Type 3로 분류될 수 있다. 즉 이 鹽河口의 수층은 漲潮流에 의해서 成層化하고 高潮後의 落潮流는 수층간의 밀도차를 줄여 서 亂流化한다. 이곳의 저층 흐름은 일반적으로 난류성이다. 한 조석 週期당 부유 물질의 이동량은 潮差와 하천유량에 달려있다고 생각된다. 관측기간중 최대의 부 유물질 이동은 하천유량이 최소였던 1991년 5월중 남측 수로에서의 측정치에서 초당 20.61톤으로 나타났으며, 최소 이동은 최소 潮差 기간인 1992년 7월에 북측 수로에서 초당 0.65톤으로 나타났다. 본 연구해역의 강한 해저전단속도는 창조류 기간 동안에 해저퇴적물을 침식시키며, 상대적으로 긴 落潮 기간은 이들 부유퇴적 물을 외해쪽으로 운반시키고 있다. 정상적인 강수 유입 조건하에서는 대부분의 부유물질이 남측 수로를 통해서 운반되나 강수의 유입이 많아지는 경우에는 오히 려 북측 수로를 통한 부유물질의 이동이 더 크다.

• 한국농공학회지
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• 제24권4호
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• pp.80-91
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• 1982

To precict the suspended sediments which are 80% of total sediments in a flood disch- arge, an equation representing vertical distribution of sediment concentration was derived based upon the diffusion theory and the logalithmic velocity distribution function in the tubulent flow mechanism. The hypothesis that the uniform mass transfer is occurred at upper part along the center line of water depth, was established as a preconition to solve the problem. The theorecal and the observed values were compared. And the theoretical equation was modified to be fit the theoretical values the observed values. Observed results are as follow; 1) Equation 12) is the theoretical equation representing the vertical concentration distri- bution of suspended sedimenta 2) Rous&exonential type vertical concentration distribution equation shows signification errors near the water surface. But the equation 12) shows substation cocentration values near the water surface. 3) Equation 15) is the modified theoretical equation which is possible to predict the vertical concentration distribution of suspended sediments.

• 한국해양학회지
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• 제30권4호
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• pp.262-270
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• 1995

금강 하구언 갑문의 폐쇄에 따른 금강하구의 물리, 퇴적학적 특성변화를 살펴 보 았다. 갑문쇄 이후 최대조류 유속은 갑문개방 시기에 비하여 약 30-40% 감소하였다. 또한 금강하구의 수괴유동이 둔화되어, 염분 및 수괴투명도의 수직적 성충(vertical stratification)이 형성되었다. 이에 따라 금강하구는 갑문개방기의 완전혼합형 (wellmixed type) 하구로부터 갑문쇄 이후에는 부분혼합형(partially-mixed type) 또 는 염쇄기형(salt-wedge type)하구로 변이하였다. 갑문이후 부유물함량은 표층에서 1 0∼100 mg/l의 범위로 측정되어, 갑문개방기에 비하여 약 1/4∼1/3의 수준으로 뚜렷하 게 감소하였다. 이와 같은 부유물함량의 감소경향은 첫째 조류유속이 감소하여 해저퇴 적물의 저층재부유 현상이 감소하였고, 둘째 수괴의 수직적성층이 형성되어 저층 혼탁 수의 상부확산이 둔화되었기 때문으로 변이하였고, 세립질 부유퇴적물의 퇴적작용이 보다 활발하게 나타날 것으로 예상된다.