• 제목/요약/키워드: Addition Test

검색결과 12,129건 처리시간 0.043초

Development of Metallic Bipolar Plate Material with W-addition in Austenitic Stainless Steel for PEMFC Environment

  • Kim, Kwang Min;Koh, Sung Ung;Kim, Kyoo Young
    • Corrosion Science and Technology
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    • 제5권5호
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    • pp.153-159
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    • 2006
  • Austenitic stainless steels with addition of various amounts of Mo and W were evaluated in terms of corrosion and contact resistance to determine optimum alloy composition of metallic bipolar plate for PEMFC. The corrosion property was evaluated by both acid fume exposure test at $130^{\circ}C$ and by electrochemical polarization tests in $H_3PO_4$ solution at $80^{\circ}C$. Austenitic stainless steel with proper amount of Mo and W demonstrated not only good corrosion resistance but also low contact resistance. Analyses on the passive film show that partial substitution of Mo by W enhances passive film stability and repassivation property. Test results suggest that austenitic stainless steel with 2 wt%Mo and 4 wt%W has optimum composition for metallic bipolar plate used in PEMFC.

홍어 분말 첨가 쿠키의 품질 특성 연구 (Quality Characteristics of Cookies fortified with Skate (Raja kenojei) Powder)

  • 조희숙;김경희
    • 한국식생활문화학회지
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    • 제23권6호
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    • pp.771-778
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    • 2008
  • This study was conducted to investigate the quality characteristics of cookies prepared using skate powder (0, 1, 3, 5, 7%) as a substitute for flour. The pH of the cookie dough decreased significantly in response to the addition of all levels of skate powder. However, there were no significant differences in the dough values among the test groups. Furthermore, when the spread factor values were compared among groups, they were found to be inversely proportional to the skate powder concentration. In addition, the Hunter's color L, a and b values decreased significantly as the level of skate powder increased. Moreover, the addition of 1-7% skate powder resulted in increased hardness, cohesiveness, springiness, and brittleness when compared to the control. Finally, the results of the sensory evaluation and acceptance test showed that the cookies containing 3% skate powder had the highest scores.

The Effect of Copper on Feeding Characteristics in Al-Si Alloys

  • Young-Chan Kim;Jae-Ik Cho
    • 한국주조공학회지
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    • 제43권6호
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    • pp.294-301
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    • 2023
  • The effects of Cu on feeding and macro-porosity characteristics were investigated in hypo- (A356 and 319) and hypereutectic (391) aluminum-silicon alloys. T-section and Tatur tests showed that the feeding and macro-porosity characteristics were significantly different between the hypo- and hypereutectic alloys. The hole and the pipe in the T-section and the Tatur casting in hypereutectic alloy showed a rough and irregular shape due to the faceted growth of the primary silicon, while the results of the hypoeutectic alloys exhibited a rather smooth surface. However, the addition of Cu did not strongly affect the macro-feeding behavior. It is known that copper segregates and interferes the feeding process in the last stage of solidification, possibly leading to form more amount of micro shrinkage porosity by the addition of Cu. The macro porosity formation mechanism and feeding properties were discussed upon T-section and Tatur tests together with an alloying addition.

Hybrid mesh 및 sliding mesh를 이용한 선박 저항추진 성능 시험 (SHIP RESISTANCE AND PROPULSION PERFORMANCE TEST USING HYBRID MESH AND SLIDING MESH)

  • 박범진;이신형
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2009년 추계학술대회논문집
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    • pp.77-83
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    • 2009
  • In this study, we conducted resistance and propulsion performance test of ship composed of the Resistance Test, Propeller Open Water Test and Self Propulsion Test using the CFD(Computational Fluid Dynamics). We used commercial RANS(Reynolds Averaged Navier Stokes equation) solver, as a calculating tool. The unstructured grids were used in a bow and stern of ship, having complex shape, for a convenience of generating grids, and the structured grids were adopted in a central hull and rest of hull having a relatively simple shape which is called hybrid grid method. In addition, The sliding mesh method was adopted to rotate a propeller directly in the Propeller Open Water and Self Propulsion Test. The Resistance Test and Self Propulsion Test were calculated using Volume of Fluid (VOF) model and considering a free surface. And all The three cases were applied realizable k-epsilon model as the turbulence model. The results of calculations were verified for the suitability of calculations by comparing MOERI's EFD results.

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CaO가 첨가된 Mg-3Al, Mg-6Al 및 Mg-9Al Eco-Mg 합금의 발화 저항성 평가 (Ignition resistance of CaO added Mg-3Al, Mg-6Al and Mg-9Al Eco-Mg alloys)

  • 이진규;김세광
    • 한국주조공학회지
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    • 제31권2호
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    • pp.60-65
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    • 2011
  • Molten magnesium alloys and magnesium products are easily oxidized and burned when they are exposed to high temperature for manufacturing process and by accident. In order to solve these problems, CaO addition in magnesium alloys has been developed. The ignition resistance of CaO added Mg-3Al, Mg-6Al, and Mg-9Al Eco-Mg alloys were investigated in comparison with those of magnesium alloys without CaO. The ignition resistance was examined by three methods : DTA, furnace chip ignition test, and torch ignition test. DTA was carried out for obtaining quantitative ignition temperature data with respect to specimen geometry and test environment; the furnace ignition test for burr and chip ignition temperature data; and the torch test for ignition temperature data for manufactured products. The ignition resistance of magnesium alloys under all conditions greatly increased by CaO addition.

BDU 신뢰성 검증 (Reliability Verification of Battery Disconnecting Unit)

  • 윤혜림;유행수;박지홍;박홍태
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2011년도 제42회 하계학술대회
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    • pp.866-867
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    • 2011
  • As part of the green growth, The Green Car has attracted wide attention. Types of the Green Car are Electric Vehicle, Plug-in Hybrid Electric Vehicle, Hybrid Electric Vehicle, Fuel Cell Vehicle and Clean Diesel Vehicle. Of these, The electric vehicle is equipped with the BDU(Battery Disconnecting Unit). BDU is supplying stable battery power and blocking it to protect electrical system of the electric vehicle. The BDU consists of electric components such as current sensor, fuse and pre-charge resistor. These must pass Voltage withstand test, Salt mist test, Thermal shock test, Vibration test and Short-circuit test commonly to verify reliability of the electric components. In addition, The current sensor should be verified whether normal operation. The breaking capacity of fuse should be verified. The durability of pre-charge resistor should be verified by supplying battery power and blocking it repeatedly. The reliability of BDU as well as the electric vehicle is secured by verifying the reliability of electric components. In addition, It will contribute to the acceleration and promotion of Green Car Technology.

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소방공무원의 직업 적성도 도입에 관한 연구 (Study on the adoption of vocational aptitude test in the fire service)

  • 박경진;이봉우;이근출;남기훈
    • 한국산업융합학회 논문집
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    • 제22권2호
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    • pp.155-161
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    • 2019
  • Recently, increases in major disasters such as fires, earthquakes and typhoons have raised public expectations for safety. In addition to this increase in expectations of safety, the government continues to push for more manpower and better treatment for firefighters who are operating in the disaster scene. Despite the improvement of working conditions and increased welfare for firefighters, however, the incidence and turnover of various mental diseases continues to increase. It is reported that many of the diseases such as post-traumatic stress disorder and the turnover of firefighters are due to a mismatch in individual's personality and work environment. In this study, 108 firefighters were evaluated for their vocational aptitude in the new curriculum. Based on the analysis results, new firefighters were proposed to provide employment and education training improvements, and to provide job security suitable for the individual's personality type through the introduction of the vocational aptitude test for firefighters who are working in the fire service. In addition, we would like to use the vocational aptitude test as a material for reducing post-traumatic stress disorder and increasing turnover through long-term tracking and observation, rather than from a one-off perspective.

Ecotoxicity Assessment of Potassium Hydrogen Phthalate and Verification of Standard Reference Toxicity Test Method Using Potassium Hydrogen Phthalate

  • Dong Jin Choi
    • Proceedings of the National Institute of Ecology of the Republic of Korea
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    • 제4권1호
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    • pp.49-62
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    • 2023
  • Phthalates are animal carcinogens. Potassium hydrogen phthalate (KHP), which has the least complicated structure among phthalates, is used for the analysis of total organic carbon and formaldehyde. However, its toxicity has not been confirmed. A 24-hour acute toxicity test was performed using Daphnia magna, a water flea used to evaluate aquatic toxicity owing to its high sensitivity. The lowest observed effect concentration of KHP was found to be 240 mg/L. The effects of phosphorus, nitrogen, and Cr(6+), which are able to be discharged along with KHP, were also confirmed using tests. At 240 mg/L KHP, toxicity increased as phosphorus, nitrogen, and Cr(6+) increased. In addition, tests were performed to confirm the half maximal effective concentration of KHP. Through 10 test repetitions, the average ecotoxicity value was found to be 0.3, the average half maximal effective concentration was 327.75 mg/L, and the coefficient of variation (%) was 3.16%; because the latter value is lower than 25%, which is what is generally suggested for the water pollution standard method, the reproducibility of the tests is sufficient to replace the existing standard reference toxicity test that uses potassium dichromate. In addition, the half maximum effective concentration of potassium hydrogen phthalate is approximately 218 times more than that of potassium dichromate; therefore, toxicity is relatively low. In conclusion, KHP is a feasible alternative to the highly toxic potassium dichromate for performing the standard reference toxicity test.

국내 도로환경과 Euro NCAP VRU Test Protocol v3.0.1을 고려한 AEB(V2P) 시험평가 방법에 관한 연구 (A Study on the Test Evaluation Method of AEB (V2P) Considering the Road Environment in Korea and Euro NCAP Test Protocol v3.0.1)

  • 권병헌;이선봉
    • 자동차안전학회지
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    • 제11권4호
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    • pp.28-38
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    • 2019
  • In the world, traffic accidents and environmental pollution caused by the increase of vehicles are becoming a serious social problem. According to the 2016 data published by the Korea Highway Traffic Authority, Korea owns 49.9 vehicles per 100 people. This is the 28th largest number among the 35 OECD member countries. In addition, the number of deaths from traffic accidents in Korea totaled 4,292, of which 1,714 were caused by traffic accidents involving vehicles and pedestrians. To reduce these human casualties, the automotive industry is constantly working on the development and commercialization of Adaptive Driver Assist System (ADAS). ADAS is the system providing convenience and safeness for drivers. In general, ADAS consists of Autonomous Emergency Braking (AEB), Highway Driving Assist (HDA), Adaptive Cruise Control (ACC), Lane Keeping Assist System (LKAS). Among them, the AEB detects the possibility of collision by the vehicle itself and plays a role of avoiding the collision or reducing the damage through active braking. For such AEB, Euro NCAP has been developing test-evaluation methods for the vulnerable since 2017. Therefore, In this paper analyzes the scenario of Euro NCAP VRU Test Protocol v3.0.1, which will be established in 2020, and proposes test conditions according to the Korean road traffic law. In addition, the reliability of the proposed scenario and test conditions was verified by comparing and analyzing the proposed theoretical evaluation formulas and actual test results.

파킨슨병환자의 호흡기능, UPDRS 및 Senior Fitness의 관련성 (Correlations among Respiratory Function, UPDRS and Senior Fitness in Parkinson's Disease Patients)

  • 강동연;천상명;성혜련;이경순;김경
    • The Journal of Korean Physical Therapy
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    • 제26권2호
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    • pp.48-55
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    • 2014
  • Purpose: The purpose of this study was to examine correlations among UPDRS, respiratory function, and senior fitness and to investigate the effects of restrictive respiratory function on these factors in Parkinson's disease patients. Methods: Subjects (n=25, Hoehn & Yahr (H&Y) stage: 2-3, $69.3{\pm}5.9$ yrs) from D Hospital Parkinson's Disease Center at Busan metropolitan area in the Republic of Korea volunteered for this study. They performed the pulmonary function test, UPDRS, and the senior fitness test. SPSS 18.0 was used for analysis of data, and the collected data were analyzed using Pearson's correlation coefficient (n=25). In addition, Independent t-test was used for determination of differences between two groups (between the normal pulmonary function group (n=10) and the restrictive pulmonary function group (n=10)). Results: Forced vital capacity (FVC (L)) showed significant negative correlation (r=-0.44, p<0.05) with H&Y stage in Parkinson's disease patients, and chair stand showed significant negative correlations (r=0.41, 0.43, 0.42, p<0.05) with FVC (L), FVC (%), and FEV1 (L). FVC (%) showed significant positive correlations (r=0.44, r=0.44, p<0.05) with right and left back scratch. In addition, the restrictive respiratory function group showed significantly lower FVC (%) (p<0.01) and was significantly slower (p<0.05) in the 8-foot up-and-go test than the normal respiratory function group. Conclusion: In conclusion, these results suggest that restrictive respiratory function in PD was related to H&Y stage. In addition, agility of PD patients was lower in the restrictive respiratory function group than in the normal function group.