• Title/Summary/Keyword: reaching time

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Nondestructive Interfacial Evaluation and Cure Monitoring of Carbon Fiber/Epoxyacrylate Composite with UV and Thermal Curing Using Electro-Micromechanical Technique (Electro-Micromechanical 시험법을 이용한 탄소 섬유 강화 에폭시아크릴레이트 복합재료의 자외선과 열경화에 따른 경화 모니터링 및 비파괴적 계면 평가)

  • 박종만;공진우;김대식;이재락
    • Polymer(Korea)
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    • v.27 no.3
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    • pp.189-194
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    • 2003
  • Interfacial evaluation, damage sensing and cure monitoring of single carbon fiber/thermo setting composite with different curing processes were investigated using electro-micromechanical test. After curing, the residual stress was monitored by measurement of electrical resistance and then compared to various curing processes. In thermal curing case, matrix tensile strength, modulus and interfacial shear strength were higher than those of ultraviolet curing case. The shrinkage measured during thermal curing occurred significantly by matrix shrinkage and residual stress due to the difference in thermal expansion coefficient. The apparent modulus measured in the thermal curing indicated that mechanical and interfacial properties were highly improved. The reaching time to the same stress of thermal curing was faster than that of UV curing case.

A study with more probability for predicting the quantitative severity of fire occurance in department stores (백화점 화재 발생의 확률적 접근에 의한 심각성의 정량적 예측)

  • 구진영;김광열
    • Fire Science and Engineering
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    • v.12 no.1
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    • pp.15-21
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    • 1998
  • In this research, we studied reach the conclusion with more probability for predicting the severity which based on fire cases in domestic department stores for last 30 years. Considering the number of yearly fire cases in department stores and the cost of damage, we set the risk level. Moreover, this research shows the severity of fire in department stores through its scenario applying to FPETOOL program which NIST in USA has developed. By the result of FPETOOL program operation, we could acquired information about the time reaching the point where people are in danger in temperature, smoke layer and gas concentration. When a fire breaks out in a department store, a great loss of property and life is significant, as well as the potential risk is awfully considerable. Therefore, we should prevent a five from occuring.

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A Survey for Ergonomic Work Risk Factors of Musculoskeletal Disorders in a Oriental Medicine Hospital (한방병원 종사자의 근골격계 증상과 유해요인평가)

  • Kim, Seong-Sik;Lee, Jong-Soo;Park, Dae-Sung;Lee, Byoung-Hee
    • The Journal of Korean Medicine
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    • v.33 no.1
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    • pp.136-147
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    • 2012
  • Objectives: The purpose of this study was to evaluate work-related risk factors of musculoskeletal disorders (MSDs) in various departments and tasks at an oriental medicine hospital. Methods: 269 hospital workers were selected for the study. The questionnaire survey included general characteristics, work-related characteristics and MSDs. Cross-tabulation analysis, multiple logistic regression, adjusted for age, work time, job demand and workload, were used to evaluate the effects of work-related factors on MSDs. Results: There were differences in MSDs depending on gender, age, occupation, and work-related factors. Prevalence rates of MSDs were 23.79% shoulder, 14.13% back, 10.41% neck. Risk factors for MSDs was packaging of drugs, transfer, and exercise therapy of physical therapist. Shoulder pain was significantly influenced by using power tools, over-reaching, and job demand while back pain was significantly influenced by weight-lifting operations and keyboard typing. Conclusions: The results of this study suggest that consideration of MSDs characteristics of workers in oriental medicine hospital is necessary to change unsuitable work environments and educate on preventing MSDs.

뇌졸중 환자에서 반복적인 양측성 운동학습 적용이 상지기능에 미치는 영향

  • Lee Myoung-Hee
    • The Journal of Korean Physical Therapy
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    • v.15 no.3
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    • pp.202-222
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    • 2003
  • Chronic upper extremity hemiparesis is a leading cause of functional disability after stroke. The purpose of this study were to identify effects of a 6weeks repetitive bilateral arm training on upper motor function and the reorganization of motor network. Four chronic stroke patients participated in this study. They performed for 6 consecutive weeks, 3 days a week, 30 minutes a day. In the single group study, four 5-minute periods per session of bilateral arm training were performed with the use of a custom-designed arm training machine. The results of this study was as follows. 1. Following the 6weeks period of RBAT, patient exhibited a improvement in FMA and BBT. 2. Following the 6weeks period of RBAT, it showed improvement in reaching time, symbol digit substitution and finger tapping speed of KCNT. 3. fMRI activation after RBAT showed a focal map in lesional cortical area and perilesional motor areas. These fMRI data suggest that hemodynamics response to RBAT reflect sensorimotor reorganization in contralateral hemisphere. In conclusion, these date suggest that improved upper extremity function induced by repetitive bilateral arm training after stroke is associated with reorganization of motor network as a neural basis for the improvement of paratic upper extremity function.

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Nonlinear finite element analysis of RC beams strengthened with CFRP strip against shear

  • Bulut, Nalan;Anil, Ozgur;Belgin, Cagatay M.
    • Computers and Concrete
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    • v.8 no.6
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    • pp.717-733
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    • 2011
  • Strengthening of reinforced concrete (RC) members against shear that is one of the failure modes especially avoided by using carbon fiber reinforced polymer (CFRP) is widely used technique, which is studied at many experimental studies. However, conducting experimental studies are required more financial resources and laboratory facilities. In addition, along with financial resources, more time is needed in order to carry out comprehensive experimental studies. For these reasons, a verified finite element model that is tested with previous experimental studies can be used for reaching generalized results and investigating parameters that are not studied. For this purpose, previous experimental study results are used and "T" cross-sectioned RC beams strengthened with CFRP strips with insufficient shear strength are modeled by using ANSYS software. First, finite elements modeling of the previously tested RC beams are done, and then the computed results are compared with the experimental ones whether they are matched or not. As a result, the finite element model is verified. Later, analyses of the cases without any test results are done by using the verified model. Optimum CFRP strip spacing is determined with this verified finite element model, and compared with the experimental findings.

Microbial and Physicochemical Monitoring of Granular Sludge During Start-up of Thermophilic UASB Reactor

  • Ahn, Yeong-Hee;Park, Sung-Hoon
    • Journal of Microbiology and Biotechnology
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    • v.13 no.3
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    • pp.378-384
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    • 2003
  • Mesophilically-grown granular sludge seeded in thermophilic UASB reactor was monitored to better understand the start-up process of the reactor. The reactor was fed with a synthetic wastewater containing glucose. As COD loading rate increased stepwise, methane production rate increased. Maximum values of COD removal efficiency (95%) and methane production rate (5.3 l/day) were achieved by approximately day-80 and remained constant afterward. However, physicochemical and microbial properties of granules kept changing even after day-80. Specific methanogenic activity (SMA) was initially negligible, and increased continuously until day-153 and remained constant afterward, showing the maximum value of $1.51{\pm}0.13\;g\;CH_4-COD/g$ VSS/day. Deteriorated settling ability of granules recovered the initial value by day-98 and was maintained afterward, as determined by sludge volume index. Initially reduced granule size increased until day-126, reaching a plateau of 1.1 mm. Combined use of fluorescence in situ hybridization and confocal laser scanning microscopy (CLSM) allowed to localize families of Methanosaetaceae and Merhanosarcinaceae in granules with time Quantitative analyses of CLSM images of granule sections showed abundance patterns of the methanogens and numerical dominance of Methanosaeta spp. throughout the start-up period. The trend of SMA agreed well with abundance patterns of the methanogens.

Pillared clays from natural resources as catalysts for catalytic wet peroxide oxidation: Characterization and kinetic insights

  • Kalmakhanova, Marzhan Seitovna;Diaz de Tuesta, Jose Luis;Kabykenovna, Bakytgul;Gomes, Helder Teixeira
    • Environmental Engineering Research
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    • v.25 no.2
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    • pp.186-196
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    • 2020
  • Pillared clays with Zr and Fe/Cu/Zr polycations have been prepared from natural clays found in large deposits of Kazakhstan and assessed as catalysts for the catalytic wet peroxide oxidation (CWPO), using 4-nitrophenol (4-NP) as model compound. The performance of the catalysts was followed by measuring the concentration of 4-NP, H2O2 and the total organic carbon (TOC), considering C4-NP = 5 g L-1, $C_{H_2O_2}$ = 17.8 g L-1, Ccat = 2.5 g L-1, initial pH = 3.0 and T = 50℃. At those selected conditions, the pillared clays showed higher activity than natural clays in the CWPO of 4-NP. The conversion of the model pollutant was complete when Fe/Cu/Zr-PILCs were used, with the TOC removal reaching 78.4% after 24 h with the best Fe/Cu/Zr-PILC. The H2O2, 4-NP and TOC time-evolution was well described by a kinetic model based on TOC lumps in three blocks, considering the initial TOC (corresponding to 4-NP), the production of oxidizable intermediates and the formation of refractory products.

A Study on Urban Inhabitants' Consciousness for Urban-Countryside Complex Type Villages Development - Focused on Gwang-ju Inhabitants (도시근교 도농복합형마을 개발에 관한 도시민의 의식조사 연구 - 광주광역시 주민을 중심으로)

  • Han, Seok-Jong
    • Journal of the Korean Institute of Rural Architecture
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    • v.14 no.1
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    • pp.67-74
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    • 2012
  • As the rural economy is worsening day by day due to rapidly declined population and increase of aging generation, the emptiness in the rural areas are becoming increasingly intensifying. In particular, urban runoff of young adults and middle-aged people and the decrease in birth rate have shrunk the rural population reaching to raise concerns on the stage of emptiness. On the other hand, people in the urban areas with rapid industrialization and overcrowding call for the variety of housing needs moving away from monolithic housing types. In order to solve problems of rural communities such as emptied out rural society as well as the problems of urban communities in overcrowdings, environment, and housing, it is required to develop an urban-countryside village complex pursuing advantages of the rural environment and convenience of urban living. Of this time, there needs a change in rural development policies which can make the urban residents migrate and settle in the rural areas as they are naturally embracing the rural life according to the social background and demand.

Design and Development of Master System for Monitoring Wide Area Power System (광역 전력계통 감시를 위한 상위 Master System 설계)

  • Kim, S.T.;Lee, J.H.;Kim, J.Y.;Lee, D.C.;Moon, Y.H.;Kim, T.H.;Yoon, J.Y.;Kim, D.J.;Lee, B.J.;Han, S.W.;Nam, H.K.;Sim, K.S.;Lee, S.J.;Jin, B.K.
    • Proceedings of the KIEE Conference
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    • 2006.11a
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    • pp.243-245
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    • 2006
  • In this paper, the master system of Wide Area Monitoring System in order to prevent reaching a fault influence toward power system is proposed. This system has three real time algorithms and a on-line one using i-piu transfer data and provides operators with various understandable monitoring viewers in HMI based on raw data and algorithm results.

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Control of Refrigerating Compressor Capacity Using Inverter (인버터를 이용한 냉동용 압축기의 용량 제어)

  • Yang, H.S.;Kim, H.S.;Kim, J.H.;Kim, S.B.;Kim, J.S.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.5 no.2
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    • pp.94-101
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    • 1993
  • Recently, efforts of decreasing energy consumption are continously increased and user's preference is also diversified in refrigeration and air conditioning systems. Thus, in order to satisfy these demands, high efficiency, high intelligence, and energy saving for those systems are essential. As the basic study for diverse functions and intelligence of those systems, we investigated the response characteristics through the compressor capacity control concerned with superheat and refrigeration room temperature. And, response characteristics are investigated experimentally by using micro computer based PWM inverter control method. Experimental result of the conventional on-off control method is given in order to be compared to the results of inverter control method. The results obtained through this study are summarized as follows. It is shown from the experimental results of the on-off control method that the range of temperature variation around the steady state ($-18^{\circ}C$) is very large (about $7{\sim}8^{\circ}C$) and the settling time bringing the steady state is not found. In the inverter control method, we can see that the refrigeration room temperature after reaching the setting temperature is very stable without fluctuation and a robust control for disturbance such as opening the door has been realized.

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