• Title/Summary/Keyword: Bed

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A Study on the Bed-Load Transport Rate (소류사량에 관한 연구)

  • Kang, Ju-Bok;Jeong, Yeon-Tae;Kim, Won-Gyu
    • Water for future
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    • v.22 no.2
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    • pp.191-200
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    • 1989
  • A method is presented which enables the computation of the bed-load transport rate as the product of particle velocity and bed-load Concentration. In this study, it is assumed that particle velocity is proportinal to the flow velocity near the particle and the apperance frequency of the component of the fluctuating velocity of turbulent flow close to bed is normally distributed, and the particle velocity is expressed by mean flow velocity near the particle and the function of bed shear stress. Engelund formula, which is checked indirectly to be proper to use in this study, is employed to estimate the effective shear velocity. And the dffective bed shear stress acting on particle is obtained by that shear velocity. Ashida-Michiue's formula is used to get the concentration of bed-load. Experimental data for bed-load is compared with the results of other studies and the transport fornula suggested in this paper gives results which are in good accordance with other's experimental data excepting the results obtained the case of comparatively small bed shear stress.

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Chemical Characteristics and Application for Kraft Pulp of Bed Log Wastes (표고골목의 화학적 특성과 펄프재로서의 이용방안)

  • Jeong, Myung-Joon;Kim, Dae-Young;Jo, Byoung-Muk;Oh, Jung-Soo
    • Journal of the Korean Wood Science and Technology
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    • v.33 no.3 s.131
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    • pp.79-88
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    • 2005
  • This research studied the utilization of the bed log wastes as a papermaking grade pulp. Five different bed log samples from shiitake mushroom (Lentinus edodes (Berk.) Sing) cultivation were collected by the cultivating periods of 1 to 5 years. The wood chemical composition and the characteristics of kraft pulping of each sample were investigated. The results of chemical composition showed that the rate of carbohydrate (glucose and xylose) content in sapwood was decreased as the cultivation period was increased. In heartwood, there was no significant difference. The screening yield of non-cultivated bed log from kraft pulping was higher than that of cultivated one, but the reject of cultivated one, especially for 5 year-cultivated, was lower than non-cultivated bed log. The fiber length and width was continuously decreased as the cultivation period was increased. Therefore, the freeness of the pulp from the cultivated bed log was sharply decreased comparing to non-cultivated due to the fiber cutting and the increased fine content. The dry strengths were increased according to the increasing addition level of bed log kraft pulp to KOCC and non-cultivated wood pulp. From the overall results, the pulp from 5 years cultivated bed log can be reasonably used if it is mixed with long fiber pulp for advantages such as reducing beating time.

Characterization of the Effects of Relative Humidity and Bed-depth on $CO_2$ Capture for Maximizing the Utilization Rate of Soda Lime Sorbent

  • Cho, Il-Hoon;Park, Guen-Il;Kim, Joon-Hyung;Hwang, Taek-Sung;Lee, Mi-Kyoung
    • Carbon letters
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    • v.2 no.2
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    • pp.113-119
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    • 2001
  • The advanced method for $CO_2$capture is currently one of the most important environmental issues in worldwide and it is therefore necessary to have available technologies, which minimize the discharge of $CO_2$ including Carbon-14 from nuclear facilities into the atmosphere. A key aspect of this work is to provide the technically principal data required to improve a $CO_2$ removal system for the utilization of regenerative sorbent use, specifically include suggestions regarding its modified column design (parallel dual-bed assembly), stop-restart operation and the economic feasibility of sorbent use. The removal performance of soda lime and the effects of relative humidity (RH) and packing bed-depth (BD) on $CO_2$ removal were investigated. In a single-bed, it revealed that the utilization of soda lime for $CO_2$ removal at line velocity of 13 cm/sec and bed depth of 12 cm increased with the increased relative humidity up to 85%. However, in the parallel dual-bed assembly applied with the stop-restart operation, a maximum utilization rate of soda lime for $CO_2$ removal was obtained even at 55% of RH and 8 cm of BD, specifically the utilization rate of soda lime by using this $CO_2$ removal assembly was about two-fold superior to that in a single-bed.

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Continuous Production of Agarooligosaccharides Using Packed-Bed Reactor (Packed-Bed 반응기를 이용한 한천올리고당의 연속생산)

  • 임동중;김종덕;강양순;공재열
    • KSBB Journal
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    • v.16 no.4
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    • pp.398-402
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    • 2001
  • Enzymatic hydrolysis of agar was carried out continuously to produce agarooligosaccharides by immobilized agarase in Packed-Bed Reactor. The reactor was constructed using a acryl tube with an internal diameter of 10 mm and a useful height of 140 mm. The Packed-Bed Reactor was 11 mL reactor volume as its length : diameter ratio was 14 : 1. The operation condition of reaction was performed with an 1 g/L agar concentration at 40$^{\circ}C$, 10 mM MOPS buffer(pH 7.0) and with the flow rate 3 mL∼48 mL/h at a dilution rate of 1.09∼5.45 h$\^$-1/. The hydrolysis products was identified DP6, DP4 and DP2 by HPLC. The conversion rate of agar was about 80% and amount of total agarooligosaccharide was 0.88 mg/mL at Packed-Bed Reactor.

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Construction and Monitoring of Test bed in Urban Sediment Disaster Prevention Technology (도심지 토사재해 방어기술 테스트베드 구축 및 모니터링 연구)

  • Lee, Jung-min;Kim, Hyo-Jin;Lee, Yoon-Sang;Jin, Kyu-Nam
    • Land and Housing Review
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    • v.8 no.3
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    • pp.161-169
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    • 2017
  • In this study, sediment transfer and precipitation analysis of the test bed watershed was conducted through the model for the application and practical use of the urban sediment disaster prevention technology, and used this as an aid to design to secure reliability. In addition, conducted the test bed monitoring with the defense technology, analyzed the effect, and established the maintenance plan. Analyzed the change of soil deposition volume through arbitrary slope adjustment for the currently installed stormwater conduit of the test bed watershed. As a result, it is important to reduce the total sedimentation amount in the adjustment of the slope of the entire pipeline, but it is important that the sedimentation depth of each sediment does not rise to such a degree as to threaten the performance of the pipeline. Considering these matters, it is necessary to design the pipeline to prevent the clogging of the soil from the viewpoint of the reliability of the entire pipeline. The sediment disaster defense technology test bed is divided into a new city and an old city, and old city test bed is under construction. The result obtained through the monitoring of the test bed in the new city, sediment disasters such as debris can delay the time to reach the downtown area, and it is possible to secure the golden time, such as evacuation and rescue through the warning system. Also, the maintenance of the test bed application was suggested. Continuous and systematic monitoring is required for securing the reliability of element technology and successful commercialization.

Species identification and pyrethroid resistance genotyping of recently resurgent Cimex lectularius and Cimex hemipterus in Korea

  • Susie Cho;Heung Chul Kim;Hoonsik Eom;Jae Rok Lee;Chung Hyun Ko;E-hyun Shin;Won Kyu Lee;Si Hyeock Lee;Ju Hyeon Kim
    • Parasites, Hosts and Diseases
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    • v.62 no.2
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    • pp.251-256
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    • 2024
  • The global resurgence of bed bug infestations, exacerbated by increasing international travel, trade, and insecticide resistance, has significantly impacted Korea. This study identified the bed bug species and performed pyrethroid resistance genotyping of recently resurgent bed bugs in Korea. Thirty-one regional bed bug samples were collected from 5 administrative regions: Gyeonggi-do (n=14), Seoul (n=13), Busan (n=2), Jeonllanam-do (n=1), and Chungcheongbuk-do (n=1). The samples underwent morphological and molecular identification. Twenty-four regional samples (77.4%) were identified as the tropical bed bug, Cimex hemipterus, and the remaining 7 regional samples (22.6%) were identified as the common bed bug, Cimex lectularius. The C. hemipterus regional samples carried at least three mutations associated with knockdown resistance (kdr), including 2 super-kdr mutations. The 7 C. lectularius regional samples possessed at least one of the 3 kdr-related mutations associated with pyrethroid resistance. This study confirms that the prevalent bed bug species recently in Korea is C. hemipterus, replacing the previously endemic C. lectularius. Additionally, the rise in bed bug populations with pyrethroid resistance underscores the necessity of introducing alternative insecticides.

The Effect of a Bed-Backrest Elevation System Combined With Hip and Knee Flexion on Lower Extremity Body-Pressure Reduction

  • Kim, Min-Hee;Yoo, Won-Gyu;Yi, Chung-Hwi;Kim, Han-Sung;Kim, Su-Jin
    • Physical Therapy Korea
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    • v.15 no.4
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    • pp.59-63
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    • 2008
  • Pressure sores are painful and needless complications of critical illness. and manifest as a localized area of ischemic necrosis of tissue caused by pressure. This study analyzed the bed-backrest elevation system combined with hip and knee flexion for lower extremity lower pressure reduction. Eight healthy adults aged 21 to 26 years were recruited. The Body Pressure Measurement Mat of the TekScan system was used to measure the location and magnitude of the peak pressures on the body bed interface. The SPSS statistical package was used to analyze the significance of differences between the general bed-backrest elevation system and the bed-backrest elevation system combined with hip and knee flexion using the paired t-test. The result showed that the body-pressure of the lower extremity was more significantly reduced for the bed-backrest elevation system combined with hip and knee flexion ($26.6{\pm}4.3$ mmHg) than a general bed-backrest elevation system ($37.3{\pm}5.2$ mmHg) (p<.05).

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Vertical Flow Zeolite-Filled Reed Bed for Treatment of Artificial Sewage with Intermittent Feeding (수직 흐름 제올라이트 갈대 여과상의 간헐적 주입에 의한 인공하수 처리)

  • 서정윤;김태형;최민수
    • KSBB Journal
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    • v.18 no.2
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    • pp.140-144
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    • 2003
  • The artificial sewage was treated using a vertical flow zeolite-filled reed bed. The artificial sewage was fec into the reed bed for 10 minutes every 6 hours at the hydraulic load 314 L/$m^2$ \ulcorner day. The filtering height of the reed bed was 100 cm and the zeolite mixture was filled in the reed bed. The mixture consisted of the same volume of two types of zeolites ; 0.5~1 mm and 1~3 mm in diameter. Annual average removal efficiency was CO$D_{Cr}$ 95.1%, T-N 49.5%, $NH{_4^+}$-N 99.4% and T-9 56.4%. T-N removal efficiency decreaced remarkably from 73 to 27% with the operating time. Most of T-P was adsorbed in the uper area of the reed bed. The major portion of adsorbed phosphorus was composed of Fe-, Ca- and reductant selubele Fe-P.

A Study on the Standard Establishment of Test-Bed Master Plan for Successful Realizations of U-City (U-City의 성공적 구현을 위한 테스트베드 기본계획의 기준 수립에 관한 연구)

  • Lee, Jae-Yong;Pi, Min-Hee;Jung, Ju-Young;Shin, Dong-Bin
    • Spatial Information Research
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    • v.18 no.1
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    • pp.1-10
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    • 2010
  • Even after many constructions of test-beds to verify R&D results, there is no standard to set up a consistent and systematic test-bed master plan. Therefore, this research derives standards of a u-city test-bed master plan. To verify these standards, the research constructs the potential U-City master plan targeting Cheongna district in Incheon. Standards of a test-bed master plan which is suggested by this research will bring strengths to construct a test-bed such as clear construction procedures from presenting directions of planning, saving cost, effective management of equipments, and so on.

The Effect of Early Ambulation after 4 Hours of Bed Rest in Patients with Transarterial Chemoembolization (간동맥 화학색전술을 시행 받은 환자에게서 4시간 절대침상안정 후 조기 이상의 효과)

  • Nam, Sun Hee;Kim, Young-Ju
    • Korean Journal of Adult Nursing
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    • v.28 no.1
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    • pp.53-60
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    • 2016
  • Purpose: This study was to compare the effects of early ambulation to usual care of late ambulation in patients with transarterial chemoembolization on back pain, discomfort, and puncture site complications. Methods: A nonequivalent control pretest-posttest design was used. Total 40 patients were recruited from a gastrointestinal unit of an urban general hospital in Seoul, South Korea. The experimental group began to ambulate after 4 hours of bed rest with a compression bandage after receiving transarterial chemoembolization. The control group stayed in bed with a compression bandage overnight. Results: Back pain was not significantly different between the two group. The experimental group reported significantly lower discomfort than the control group. There was no incidence of bleeding complications on puncture site between two groups. Conclusion: The results of this study showed that early ambulation with four hours of bed rest after femoral sheet removal did not cause bleeding complications compared to the usual care and even decreased patients' level of discomfort due to bed rest. Repetitive research on the effect of short bed rest is warranted for its clinical utilization.