• Title/Summary/Keyword: loading performance

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Flexural Performance and Cracking Resistance of Continuous Composite Slab using Micro Steel Fibers (마이크로 강섬유 콘크리트를 적용한 연속 합성슬래브의 휨 및 균열 저항성능)

  • Hwang, Hyeon-Jong;Park, Hong-Gun;Hong, Geon-Ho;Kim, Gap-Deug;Choi, Se-Jin
    • Journal of the Korea Concrete Institute
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    • v.27 no.4
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    • pp.387-397
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    • 2015
  • In the present study, to enhance the constructability, a composite slab system using deck plate and micro steel fiber concrete was studied. In the proposed slab system, on-situ re-bar placement is not required. Steel fibers replace the temperature reinforcement. The present study focused on the crack control at the slab top in the continuous composite slab without spliced bars. Eight continuous slabs with various parameters were tested under vertical loading. The test parameters were the amount and types of micro steel fibers, types of deck plate, and the use of top bars in the continuous slab. To evaluate the crack resistance of the slabs, crack widths were measured in the continuous slabs. The test results showed that although the top spliced bars were not used, cracking were restrained by large flexural stiffness of the composite sections.

Fundamental Aspects of Hybrid-Online Simulation for One Dimensional Consolidation Analysis (Hybrid-Online 방법을 통한 압밀해석)

  • Kwon, Young-Cheul
    • Journal of the Korean GEO-environmental Society
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    • v.7 no.1
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    • pp.67-80
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    • 2006
  • This paper presented an application of the geotechnical hybrid-online simulation to the consolidation settlement problem of soft clay. Conventional numerical analyses have used idealized soil constitutive models obtained from the laboratory soil tests. On the other hand, in the hybrid-online simulation, soil response was directly introduced to numerical analyses from the soil element test, and, therefore, the complicated parameter estimation was not required in this method. Fundamentals of the hybrid-online simulation method and the development of the algorithm and corresponding hardware and software for the system were presented in this study. Furthermore, an incremental loading consolidation and the hydraulic conductivity test and a comparative study using the Terzagh's conventional consolidation theory were carried out for the system verification including the performance of the experimental device and source coding of software components, and the data reliability obtained from the system. In conclusion, we found that the hybrid-online consolidation simulation system could reproduce the consolidation behavior of the remolded Kaolinite specimen withoutany discrepancies.

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Comparison of Performance with Backfill Inclination Slope and Shape in Railway Abutment and Transitional Zone Using Centrifuge Model Tester (원심모형실험기를 이용한 철도 교대접속부 배면 기울기 및 형상에 따른 성능비교)

  • Choi, Chan-Yong;Kim, Hun-Ki;Park, Jung-Hyun
    • Journal of the Korean Geosynthetics Society
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    • v.17 no.1
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    • pp.85-93
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    • 2018
  • A existing standard design section of transitional zone between bridge and earthwork section in high speed railway should be designed to gradually change support stiffness from bridge abutment to backfill side that were placed on cemented stabilized gravel, general gravel, soil materials. The larger the backfill slope of the general gravel and soil was more structurally stable, but there is no clear reason about them. In this study, it was compared with settlement and bearing capacity of backfill area in currently design and alternating backfill slope section using large centrifuge tester. As the experimental results, it was showed that the 1:2 slope and 1:1.5 slope have almost similar bearing capacity behavior under the load stage as railway loading level.

Effects of Muscle Strengthening Exercises Using a Thera Band on Lower Limb Function of Hemiplegic Stroke Patients (세라밴드를 이용한 근육강화운동이 뇌졸중 환자의 하지기능에 미치는 효과)

  • Han, Sang-Sook;Her, Jeong-Ja;Kim, Youn-Jung
    • Journal of Korean Academy of Nursing
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    • v.37 no.6
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    • pp.844-854
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    • 2007
  • Purpose: This study was to verify the effect of muscle strengthening exercises using a Thera-Band on the lower limbs. Methods: The design utilized for this study was a nonequivalent control group pretest-posttest design. A control group (16) and experimental group (16) were selected from stroke patients of K Oriental Medicine Hospital who were hospitalized for 5 months from December 2005 through April 2006. While only acupuncture therapy and physical therapy were used on the control group, acupuncture, physical therapy and additional muscle strengthening exercises using a red thera band were used on the experimental group. Muscle strengthening was performed 20 minutes per session, more than one session a day for 4 weeks. Hypotheses for this study were verified using Two-way repeated ANOVA and ANCOVA using a pre test score as a covariate. Results: The experimental group with thera band muscle strengthening exercises showed a decrease in asymmetry weight loading percentage(F=14.704, P= .010), range of knee (Z=-3.15, P= .001) & deep tendon reflex score(Z=-2.52, P= .012) and moving performance(F=12.328, P= .001)compared to the control group. Conclusion: It is confirmed that muscle strengthening exercises using a Thera-Band can be used as an effective nursing intervention to improve the function of the lower limb of hemiplegic stroke patients.

Biological Treatment of Dyeing Wastewater Using Jet Loop Reactor with Activated Carton Supports (활성탄 담체가 포함된 Jet-Loop Reactor를 이용한 종합염색폐수처리)

  • 조무환;박종탁;이길호;류원률
    • KSBB Journal
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    • v.17 no.3
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    • pp.241-246
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    • 2002
  • Today, many problems of dye-processing wastewaters were raised due to industry of dyeing and textiles. It is difficult to treat them perfectly because they contain many poorly degradable matters, such as surfactants, ethylene glycol, polyvinyl alcohol, and so on. To improve the performances of conventional physicochemical treatment and activated sludge process, new systems of combining jet-loop reactor (JLR) with physicochemical treatment were developed. Volumetric oxygen transfer coefficient ($k_{L}a$) of JLR was significantly larger than that of air-lift reactor. Also, for the effective treatment of dye-processing wastewater, JLR with active carbon supports (JLRAS) were investigated. Removal efficiency of BOD, $COD_{Mn}$, $COD_{Cr} and color were found as 99, 86, 84, 83%, respectively, when HRT was 8 hrs. And performance of JLRAS was rapidly restored after step change of $COD_{Mn}$ loading late. The optimal coagulant and dosage of second physicochemical treatment after JLRAS were polyferric sulfate and 130 mg/L, respectively, when removal efficiencies of $COD_{Mn} and color were 85 and 73%, respectively. In conclusion, this system enables the reduction of operation cost, and the effective removal of many organics.

Removal of Dyes by the Biosorption Using Biomass of Penicillium janthinellum (Penicillium janthinellum 균체를 이용한 생물흡착에 의한 염료의 제거)

  • 이제혁;전억한
    • KSBB Journal
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    • v.14 no.1
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    • pp.31-35
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    • 1999
  • A biosorption of azo and reactive dyes into the intact and modified biomass of Penicillium janthinellum were investigated. Initial pH of medium affected the initial adsorption rate and decolorization. The initial optimum pH was found to be 2.0, and the maximum adsorption rates of dyes were $40^{\circ}C$. The reactive dyes called Apollocion Red 7EB, Apollofix Red SF-3B and Apollocion Red H-E3B showed the high initial adsorption rates as 0.06, 0.086 and 0.079 mg/g.min, respectively. A mixture of dyes containing azo and reactive dyes was adsorbed to the biomass of Pen. janthinellum and revealed that the initial adsorption rate was 0.084 mg/g.min. Both percent decolorization and the influence on the dye adsorption rate. Modified biomass of Pen. janthinellum was also investigated for the dye adsorption and the superior dye loading performance was observed compared with the ion-exchange/chelating resins used for removal of Apollocion Red 7EB.

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Development of the lift-up and procurement system for Just-in-Time in the Building Construction (건설공사의 적시생산(Just-In-Time)을 위한 양중시스템 개발)

  • Shin Bong-Soo;Kim Chang-Duk;Suh Sang-Wook;Lim Hyoung-Chul;Choi Woon-Ki
    • Korean Journal of Construction Engineering and Management
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    • v.4 no.4 s.16
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    • pp.182-191
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    • 2003
  • The material lift-up and procurement management for high-rise buildings is complex and critical key to the success of projects. It has been hardly managed by the heuristic or rule-of-thumb techniques which are adapted in usual construction building sites. Especially in downtown high-rise residential building project sites, the limit of heuristic management techniques is critical. It has space constraint for materials loading and site transportation especially in finish work phases in which construction period diverse work trades struggle for their own material and manpower transportation. Hence, it is essential to adapt JIT(Just-In-Time) concept in these particular types of building construction project sites. According to the analysis of the case project sites, the communication and flow of relevant information regarding material lift-up and transportation in project sites is the key factor for successful performance. Therefore, this study analyzes the flow and site transportation of the key materials and provides the system, PLUTO(Procurement & Lift-Up for material Transport Optimizing system). This study also applies the system in the case site and verifies the model validation in actual project.

Development of Offshore Piles with Enlarged Upper Section (상부단면 확대형 해상 말뚝의 개발)

  • Kwon, O-Soon;Jang, In-Sung;Kwon, Young-Ho;Ki, Min-Joo
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.21 no.6
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    • pp.427-436
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    • 2009
  • In this study, new type of pile foundation was introduced for the better performance of lateral resistance than conventional piles by adopting enlarged upper section, because offshore structure design is subjected to the lateral loading. The numerical simulations were peformed in order to find out the lateral behaviour of the proposed pile. The economical efficiency of new pile system was also analyzed by considering the construction characteristics and material costs as well as the real field condition of harbor sites in Korea. From the study, it was revealed that the lateral resistance of piles with enlarged upper section is increased compared to conventional steel pile, and the construction costs would be reduced to about 62~80% of previous methods.

A Study on the Structural Integrity of the First Stage Turbine Blade Caused by Thermal Barrier Coatings and the Cooling Design of the Nozzle (터빈 노즐 및 열차폐 코팅에 따른 고압 1 단 터빈 블레이드의 구조 건전성 영향에 대한 연구)

  • Huh, Jae Sung;Kang, Young Seok;Rhee, Dong Ho
    • Transactions of the KSME C: Technology and Education
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    • v.4 no.2
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    • pp.93-99
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    • 2016
  • High pressure nozzles and turbines of a gas turbine engine should be required to be operated under extreme operating conditions in order to maximize the performance. Engine manufactures have utilized nickel-base superalloys, enhanced cooling design, and thermal barrier coating techniques to overcome them and furthermore, material modeling, finite element analysis, optimization techniques, and etc. have been utilized widely for elaborate predictions. We aim to evaluate the effects on the low cycle fatigue life of the high pressure turbine blade caused by thermal barrier coatings and the cooling design of the endwall of the first stage turbine nozzle. To achieve it, the structural analysis, which utilized the results of conjugate heat transfer analysis as loading boundary conditions, was performed and then the results were the input for the assessment of low cycle fatigue life at several critical zones.

The Actual State of Hospital-based Skill Training in Level 1 Emergency Medical Technician (소방 1급응급구조사의 병원임상수련 술기 실태 조사)

  • Roh, Sang-Gyun;Lee, Jae-Gook;Bang, Sung-Hwan
    • Fire Science and Engineering
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    • v.26 no.5
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    • pp.54-60
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    • 2012
  • This study is the analysis of the actual state of hospital-based training in level 1 emergency medical technicians (EMTs) in fire station. The survey was carried out to 42 fire fighters having level 1 emergency medical technician certification from May 11 to 12 in 2012. The results showed 56.5 %, that the level 1 EMTs of roles had direct experienced. Level 1 EMTs performance frequency of clinical practice that endotracheal intubation 66.9 %, laryngeal mask airway 8.4 %, intravenous access 76.6 %, nitroglycerin sublingual 61.2 %, bronchodilator inhalation 50.0 %, fluid loading 73.8 %, ventilator apply 57.6 %, dextrose injection 57.6 %. It is necessary to investigate the continuous study on the education among the level 1 EMTs and the continuous evaluation and analysis of problems, supplemented of guidebook, practical education programs and regulation upon the operation and management of a hospital-based skill training.