• 제목/요약/키워드: experiment conditions

검색결과 5,360건 처리시간 0.037초

실험계획법에 의한 AZ31 마그네슘 합금의 마찰교반용접 특성에 관한 연구 (A Study on the Friction Stir Welding Characteristics of AZ31 Mg Alloy by the Design of Experiment)

  • 강대민;박경도;정영석
    • 한국자동차공학회논문집
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    • 제21권4호
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    • pp.77-82
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    • 2013
  • In this paper, the design of experiment with two-way factorial design was adopted and from that, optimum values of welding variables including the welding speed and rotation speed were found to improve the strength of AZ31 magnesium alloy sheets joined by the friction stir technique. Tool with shoulder diameter of 12 mm and pin diameter of 3.5 mm was used. Also the welding direction was aligned with the material rolling direction, and dimensions of the AZ31 magnesium alloy sheets were $100{\times}100{\times}2mm$. Conditions of rotation speed were 1000, 1100 and 1200 rpm and those of welding speed were 200, 300 and 400 mm/min. As far as this work is concerned, the optimal conditions for friction stir joint were predicted as the rotation speed of 1200 rpm and welding speed of 200 mm/min.

추적자 확산실험에 의한 야간 강안정층하에서의 가우시안 퍼프모델의 평가 (Evaluation of Gaussian Puff Model with Tracer Experiment under Nighttime Strong Stable Conditions)

  • 이종범;김산;김용국;조창래;유승도
    • 한국대기환경학회지
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    • 제12권5호
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    • pp.529-540
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    • 1996
  • Dispersion experiment using SF$_{6}$ tracer was performed in the flat field of Chunchon Basin during four nights from August 29 to September 2, 1991. The purpose of this study is to analyze toe horizontal distribution of tracer concentration under the strong stable conditions and to evaluate the results calculated by INPUFF model. Incase of high wind speed, plume spread of SF$_{6}$ concentration appeared in narrow area of the downwind and the standard deviation of the horizontal wind angle (.sigma.$_{a}$) was amall. However, the SF$_{6}$ was spread widely in cases of low wind speed because of the large .sigma.$_{a}$. The result of the INPUFF model was similar to the observed distribution of the SF$_{6}$ concentration. It is proved that the Gaussian puff model is useful when wind direction varies significantly.tly.tly.tly.

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큰양송이 Portobella 균주의 배양조건 및 형태적 특성 (Cultural conditions and morphological characteristics of Portobella, Agaricus brunescens)

  • 지정현;이재홍;김희동;김영호
    • 한국버섯학회지
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    • 제1권1호
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    • pp.21-27
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    • 2003
  • 국내외에서 수집된 큰양송이(포토벨라)의 균주와 양송이 ASI707을 공시하여 균사체 배양조건과 균주별 자실체의 형태적 특성을 조사한 결과는 다음과 같다. 퇴비추출배지에서 균사생장이 우수하였고, 최적배양온도는 $25^{\circ}C$, pH는 7.0 이었다. 균사생장에 가장 적합한 탄소원으로 Sucrose와 Starch 질소원으로는 Malt extract가 선발되었고 최적 C/N율은 10이었다. 인공재배한 자실체는 공시균주간에 갓크기, 갓두께 등에서 큰 차이가 없었으나 개체중은 25.8~33.8g 내외로 균주간에 다소 차이를 보였다. 공시균주 중 KME59007은 다발성으며 평당 수량도 44.6kg으로 가장 많았다.

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포화 컬럼실험에서 이온강도 변화 및 유기물질 출현에 의한 PVP로 코팅된 은나노 입자의 거동 연구 (Transport behavior of PVP (polyvinylpyrrolidone) - AgNPs in saturated packed column: Effect of ionic strength and HA)

  • 허지용;한종훈;허남국
    • 상하수도학회지
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    • 제30권3호
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    • pp.263-270
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    • 2016
  • Recent Engineered nanoparticles were increasingly exposed to environmental system with the wide application and production of nanomaterials, concerns are increasing about their environmental risk to soil and groundwater system. In order to assess the transport behavior of silver nanoparticles (AgNPs), a saturated packed column experiments were examined. Inductively coupled plasma-mass spectrometry and a DLS detector was used for concentration and size measurement of AgNPs. The column experiment results showed that solution chemistry had a considerable temporal deposition of AgNPs on the porous media of solid glass beads. In column experiment, comparable mobility improvement of AgNPs were observed by changing solution chemistry conditions from salts (in both NaCl and $CaCl_2$ solutions) to DI conditions, but in much lower ionic strength (IS) with $CaCl_2$. Additionally, the fitted parameters with two-site kinetic attachment model form the experimental breakthrough curves (BTCs) were associated that the retention rates of the AgNPs aggregates were enhanced with increasing IS under both NaCl and $CaCl_2$ solutions.

A Simple Method of Seedling Screening for Drought Tolerance in Soybean

  • Kim, Young-Jin;S. Shanmungasundaram;Yun, Song-Joong;Park, Ho-Ki;Park, Moon-Soo
    • 한국작물학회지
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    • 제46권4호
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    • pp.284-288
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    • 2001
  • Water deficit is a serious constraint to soybean [Glycine max L. (Merr.)] production in rainfed regions of Asia, Africa, and America. This study was conducted to develop a simple and effective screening method for drought tolerance in soybean. Fifteen soybean cultivars, eight identified to be drought-tolerant and seven drought-sensitive in previous studies, were used for the evaluation of drought tolerance under the new screening conditions. The seedling screening method was consisted of a treatment in a PEG solution and drought treatment in parafilm-layered pots. 5-day-old seedlings were treated in a 18% PEG solution for 4 days and their wilting and hypocotyl browning were recorded. Three seedlings grown in a parafilm-layered pot containing peat moss were drought-stressed by withholding water from the third day after seedling emergence, and root and seedling growth were examined. Degree of drought tolerance were rated based on seedling vigor in the PEG solution and drought-stressed parafilm-layered pots, and also on the penetration ability of roots through parafilm layer. Most of seedlings of the drought-tolerant cultivars showed higher vigour and root penetration than those of the drought-sensitive cultivars under the new screening conditions. Our results indicate that the new method can be used as a simple and effective screening procedure for drought tolerance in soybean breeding programs.

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편측창에서 창개구부의 형상이 천공상태별 채광성능에 미치는 영향 (Effects of Different Fenestration Configurations on Daylighting Performance in Unilateral Window under Clear and Overcast Sky Conditions)

  • 술타나 아즈미리;김정태
    • KIEAE Journal
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    • 제9권5호
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    • pp.105-113
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    • 2009
  • Daylighting provides the opportunity for both energy savings and improved visual comfort. An accurate estimation of the amount of daylight entering a building is the key step for daylight designing. This research aims to assess comparative daylighting performance of four different configurations of fenestration in case of unilateral windows and their variation under clear and overcast sky conditions. The selected window openings in this study were single punched, double punched, multiple punched and clerestory, and the area was same for each type of window. The experiment was designed for an office space using 1/10 scale model. Daylighting performance was evaluated by measuring the illuminance on work-plane height using Agilent data logger and photometric sensor Li-Cor. Thecomputer program ECOTECT was also used to simulate the pattern of interior illuminance distribution. Clerestory window showed the best performance in term of both illuminance level and distribution in the experiment. Multiple punched window provided more uniform illuminance distribution than single punched window. Lowest daylighting performance in the experiment was shown by double punched window.

Magnetron Sputtering법에 의해 증착한 MoS$_2$ 박막의 고진공하에서의 트라이볼로지적 특성 (Tribological characteristics of sputtered MoS$_2$films with Magnetron Sputtering Method in High Vacuum)

  • 안찬욱;김석삼;이상로
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 2000년도 제32회 추계학술대회 정기총회
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    • pp.406-413
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    • 2000
  • The friction and wear behaviors of Magnetron Sputtered MoS$_2$films were investigated by using a pin on disk type tester which was designed and manufactured for this experiment. The experiment was conducted by using silicon nitride (Si$_3$N$_4$) as a pin material and Magnetron Sputtered MoS$_2$on bearing steel (STB2) as a disk material, under operating conditions that include different surface roughness (Polishing specimen, Grinding specimen)(2types), linear sliding velocities in the range of 22, 44, 66mm/sec (3types), normal loads vary from 9.8N, 19.6N, 29.4N(3types), corresponding to contact pressures of 1.9∼2.7GPa and atmospheric conditions of high vacuum( 1.3${\times}$10$\^$-4/Pa), medium vacuum( 1.3${\times}$10$\^$-l/Pa), ambient air(10$\^$5/Pa)(3types). We investigated fracture mechanism in magnetron sputtered MoS$_2$films with Magnetron Sputtering method in each experiment.

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Analytical and experimental study on natural sloshing frequencies in annular cylindrical tank with a bottom gap

  • Lee, H.W.;Jeon, S.H.;Cho, J.R.;Seo, M.W.;Jeon, W.B.
    • Structural Engineering and Mechanics
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    • 제57권5호
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    • pp.877-895
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    • 2016
  • This paper is concerned with the analytical derivation of natural sloshing frequencies of liquid in annular cylindrical tank and its verification by experiment. The whole liquid domain is divided into three simple sub-regions, and the region-wise linearized velocity potentials are derived by the separation of variables. Two sets of matrix equations for solving the natural sloshing frequencies are derived by enforcing the boundary conditions and the continuity conditions at the interfaces between sub-regions. In addition, the natural sloshing frequencies are measured by experiment and the numerical accuracy of the proposed analytical method is verified through the comparison between the analytical and experimental results. It is confirmed that the present analytical method provides the fundamental sloshing frequencies which are in an excellent agreement with the experiment. As well, the effects of the tank radial gap, the bottom flow gap and the liquid fill height on the fundamental sloshing frequency are parametrically investigated.

노인을 위한 스마트 홈 시스템 장기 모니터링 실증 연구 (A Long-term Monitoring Demonstration of Smart Home System for the Elderly)

  • 이지헌;차승현
    • 한국BIM학회 논문집
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    • 제11권3호
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    • pp.75-90
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    • 2021
  • A smart home system improves the elderly's quality of life by monitoring and analyzing their movements and health conditions with better health-care and social support services. Therefore, there has been an effort to adopt a smart home system for the independently living elderly. However, to the best of our knowledge, no study has investigated the usability of a smart home system on actual independently living elderly housing in long-term settings. Thus, this study aims to demonstrate the usability of a smart home system on independently living elders in living lab conditions. The BLE smart band and the BLE receiver were chosen for the smart home system to monitor the movement of the participants in their homes as well as to monitor the heart rates, step counts, sleep index. Nine independent living elderly from the senior welfare center in Kimjae participated in this living lab demonstration experiment for ten months. This demonstration experiment confirmed the effectiveness of low-cost and easily adoptable IoT-based BLE sensor sets on independent living elders and discussed the troubles and limitations of the experiment. By grasping the pros and cons of IoT-based BLE sensor sets, this study seeks to improve the accessibility and usability of smart home systems for the elderly population in independent living arrangements.

전해연마 용액에서 안정화 시간과 표면 거칠기에 따른 오스테나이트 스테인리스강의 전기화학적 특성 (Electrochemical Properties of Austenitic Stainless Steel with Initial Delay Time and Surface Roughness in Electropolishing Solution)

  • 황현규;김성종
    • Corrosion Science and Technology
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    • 제21권2호
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    • pp.158-169
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    • 2022
  • The objective of this study was to investigate the electrochemical behavior and damage degree of metal surface under different conditions by performing a potentiodynamic polarization experiment using an electropolishing solution for UNS S31603 based on initial delay time and surface roughness (parameters). A second anodic peak occurred at initial delay time of 0s and 100s. However, it was not discovered at 1000s and 3600s. This research referred to an increase in current density due to hydrogen oxidation reaction among various hypotheses for the second anodic peak. After the experiment, both critical current density and corrosion current density decreased when the initial delay time (immersion time) was longer. As a result of surface analysis, characteristics of the potentiodynamic polarization behavior were similar with roughness, although the degree of damage was clearly different. With an increase in surface roughness value, the degree of surface damage was precisely observed. As such, electrochemical properties were different according to the immersion time in the electropolishing solution. To select electropolishing conditions such as applied current density, voltage, and immersion time, 1000s for initial delay time on the potentiodynamic polarization behavior was the most appropriate in this experiment.