• 제목/요약/키워드: Rate Stick Test

검색결과 19건 처리시간 0.025초

엔진 물통로 내부 벽면 스케일 축적이 LPG 엔진의 열적 내구성에 미치는 영향에 대한 연구 (A Study on Effect of Scale Formation in Water Jacket on Thermal Durability in LPG Engine)

  • 류택용;신승용;최재권
    • 한국자동차공학회논문집
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    • 제9권3호
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    • pp.42-50
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    • 2001
  • In this paper, the effects of scale formation in engine water jacket upon the thermal durability of engine itself and its component parts were studied. To understand the effect of quality of water, a full load engine endurance test for 50 hours was carried out with not-treated underground water. The followings were found through the tested engine inspection after the endurance test; 1-2 mm thick scale formation in the engine water jacket, valve seat wear, piston top land scuffing, piston pin stick, and cylinder bore scuffing in siamese area. In order to understand the causes of above test results, the heat rejection rate to coolant, the metal surface temperature of combustion chamber, and the oil and exhaust gas temperatures were measured and analyzed. The scale formed in the engine water jacket played a role as thermal insulator. The scale formed in the engine reduced the heat rejection rate to coolant and it caused to increase the metal surface temperature. The reduced heat rejection rate to coolant increased the heat rejection rate to oil and exhaust gas and increased the oil and exhaust gas temperature. Also, the reasons of valve seat wear, piston top land scuffing and cylinder bore scuffing, and piston pin stick quantitatively analyzed in this paper.

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신생아의 통증완화를 위한 포도당 경구투여 효과 (The Effect of Oral Glucose on Pain Relief in Newborns)

  • 안혜영;장미영;허명행
    • 대한간호학회지
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    • 제36권6호
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    • pp.992-1001
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    • 2006
  • Purpose: This study was done to provide data for a nursing intervention to alleviate newborn pain clinically by investigating the effect of oral glucose. Methods: Subjects were newborns hospitalized in the nursery. Informed consent was obtained from parents of 60 newborns. A heel stick was carried out for a test on 3 groups; the experimental, placebo, and control group. The Neonatal infant pain scale(NIPS), respiration rate, heart rate, peripheral oxygen partial pressure($SpO_2$), and crying duration were measured to assess pain reaction. All neonatal behaviors were recorded on videotape. Results: There were significant differences in pain behavior during stimulus(F=4.195, p=.020), pain behavior immediately after blood-sampling (F=4.114, p=.021), and pain behavior 3 minutes after that (F=3.630, p=.033). However, there were no significant differences in heart rate, respiration rate, peripheral oxygen partial pressure or crying duration after the heel stick among the groups. Conclusions: Oral administration of glucose before a heel stick caused the reduction of neonatal pain behavior, which means that it has an effect of pain relief.

PETN 기반 복합화약의 구성방정식 파라미터 결정 및 검증 (A Parametric Study of Constitutive Relations for PETN Based Explosive)

  • 백동현;김보훈;여재익
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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    • pp.462-468
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    • 2017
  • KYP 모델은 화약의 폭굉 반응속도를 기술하는 압력기반모델이다. 본 연구에서는 PETN 기반 복합 화약(PBXN-301)의 KYP 모델 및 JWL EOS의 파라미터를 결정하였다. 크기효과를 얻기 위하여 반응 막대 시험을 수행하였고 2차원 하이드로다이나믹 해석 결과와 비교하였다. 해석 결과, 정성적으로 얻어진 LLNL의 구성방정식보다 KYP 모델링을 통해 도출된 파라미터가 PBXN-301 화약의 역반지름에 따른 폭굉파속을 잘 예측하는 것으로 나타났다.

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간호대학생의 주사침 자상에 대한 지식, 이행 및 위험인식 (Knowledge, Compliance and Levels of Risk Factor Recognition for Needlestick Injuries in Student Nurses)

  • 박선남;이은영;김경미;한숙정
    • 기본간호학회지
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    • 제12권3호
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    • pp.337-346
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    • 2005
  • Purpose: The purpose of this study was to investigate the levels in student nurse of knowledge, compliance and risk factor recognition for needlestick injuries. Method: Nine hundred and thirty eight(938) student nurse from 3 universities and 3 junior colleges participated in this study. Completed questionnaires were collected between October and November 2004. They were analyzed by using the descriptive statistics and $x^2$-test, t-test with the SAS program, Results: There were no significant differences in the general characteristics of participants between the two groups-Needlestick Injury(NSI) group and non-Needle stick Injury(non-NSI) group. The scores for knowledge levels of treatment after needle stick injuries and the risk factor recognition level were significantly higher in the NSI group. The scores for performance level as to handling and using needles after needlestick injuries were significantly higher in the non-NSI group. Conclusion: It is necessary to develop a preventive program to decrease the needlestick injury rate among student nurse.

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교통약자를 고려한 보도의 경사도와 높이 결정을 위한 실험연구 (Experimental Study on the Determination of Slope and Height of Curbs Considering the VRUs)

  • 김현진;임준범;최병호;오철;강인형
    • 한국도로학회논문집
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    • 제20권1호
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    • pp.107-115
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    • 2018
  • PURPOSES : As the population of the mobility handicapped, who are classified as the disabled, the elderly, pregnant women, children, etc., has increased, the voices for guaranteeing their rights have been increasing as well. Thus, the design manuals for roads and sidewalks for the mobility handicapped were developed by the local government, such as the Ministry of Land, Transport, and Tourism, in Seoul City. However, according to the 2013 survey results of the Seoul Metropolitan City, the mobility handicapped still feel uncomfortable with the sidewalks, and particularly request for the improvement of the step and slope of the sidewalk curb. Therefore, in this study, we conducted an empirical experimental study to determine the slope of the sidewalk curb and height of the steps considering the mobility handicapped and analyzed whether there is a statistically significant difference. METHODS : The methodology of this study is an empirical experimental one. In the study, five non-disabled people, 10 wheelchair users, and 10 eye patch and stick users walked about 2-3 min on the sidewalk plates of the sloped type (0%, 5%, 6.3%, 8.3%) and stepped type (0 cm, 1 cm, 3 cm, 6 cm), and their human physiological responses, such as the skin temperature, volume of perspiration on forehead and chest, and heart rate, were measured and recorded. After combining the data, we conducted a nonparametric test, ANOVA, or t-test to determine whether there was a statistically significant difference according to each slope and step type. RESULTS : It was found that for the non-disabled, there was no significant difference in human physiological responses according to the slope and steps of the sidewalk. It can be said that the non-disabled do not feel much physiological discomfort while walking. In the case of the sloped sidewalk plate, the heart rate of the wheel chair users increased when the slope was 6.3%. In the case of the eye patch and stick users, the volume of perspiration on the chest increased at a slope of 5.0%. In general, it is judged that a sidewalk with a slope that is less than 5% does not cause a change in the physiological response. In the case of a stepped sidewalk plate, when 0 cm, 1 cm, and 3 cm were compared for wheelchair users, the amount of forehead perspiration increased from 1 cm. Meanwhile, in the case of the eye patch and stick users, when 0 cm and 6 cm were compared, the amount of perspiration on the forehead and chest as well as the heart rate all increased at 6 cm. Taken together, in the case of wheelchair users, a difference was shown when the height of the step of the sidewalk plate was 1 cm, suggesting that installing it at 0 cm does not cause any physiological discomfort. Moreover, in the case of the eye patch and stick users, when comparing only 0 cm and 6 cm, 0 cm was considered to be suitable, as there was a difference in physiological response at 6 cm. CONCLUSIONS : In this study, we set the human physiological responses such as chest skin temperature, amount of perspiration, and heart rate as evaluation items, and our study was considered to be a meaningful experiment that targeted wheelchair users as well as eye patch and stick users. The validity of the evaluation items was confirmed, as the results of human physiological responses were significant. As for the sidewalk design, according to the experiment result, it is considered that differential application should be implemented according to the type of mobility handicap, rather than uniformly applying a sidewalk step of 2 cm and sidewalk slope of 1/25, which are the current legal standards.

Fretting Wear and Friction of lnconel 690 for Steam Generator Tube in Elevated Temperature Water

  • Lee, Young-Ze;Lim, Min-Kyu;Oh, Se-Doo
    • KSTLE International Journal
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    • 제3권1호
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    • pp.49-53
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    • 2002
  • Inconel 690 for nuclear steam generator tube has more chromium than the conventionally used Inconel 600 in order to increase the corrosion resistance. TD evaluate the tribological characteristics under fretting condition the fretting tests as well as sliding tests were carried out in elevated temperature water environment. Fretting tests of the cross-cylinder type were done under various vibrating amplitudes and applied normal loads in order to measure the friction forces and wear volumes. Also, the conventional sliding tests of pin-en-disk type were carried out to compare the test results. In fretting, the friction was very sensitive to the load and the amplitude. The friction coefficient decreased with increasing load and decreasing amplitude. Also, the wear of Inconel 690 can be predictable using the work rate model. Depending on normal loads and vibrating amplitudes, distinctively different wear mechanisms and of ten drastically different wear rates can occur. It was fecund that the fretting wear coefficients in water were increased as increasing the temperature of water.

지르칼로이-인코넬 접촉에서의 프레팅 손상 평가 (Fretting Oamage Evaluation of Zircaloy-Inconel Contact)

  • 김태형;김석삼
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 2000년도 제31회 춘계학술대회
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    • pp.263-268
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    • 2000
  • The fretting damage of the contact between Zircaloy-4 and Inconel 600 have Investigated. A fretting wear tester was designed to be suitable for this fretting test. In this study, the number of cycles, slip amplitude and normal load were selected as main factors of fretting wear. As the result of this research the wear volume increased with the increase of loads, slip amplitudes and the number of cycles and was more affected by slip amplitudes rather than by load. According to SEM, stick, partial slip, gross slip were observed on the surface of both specimens and wavy worn surfaces as the typical fretting damage were also Investigated due to accumulation of plastic flow.

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A12024-T4의 프레팅 피로균열거동에 관한 실험적 연구 (An experimental study on the fretting fatigue crack behaviour of A12024-T4)

  • 이봉훈;이순복
    • 대한기계학회논문집A
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    • 제21권3호
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    • pp.511-518
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    • 1997
  • The technique of fretting fatigue test was developed and fretting fatigue tests of A12024-T4 were conducted under several conditions. The newly developed calibration methods for measuring surface contact tractions showed good linearity and repeatability. The plate type specimen to which tow bridge type pads were attached and vision system was used to observe the crack behaviour. The oblieque cracks appeared in the early stage of crack growth and they became mode I cracks as they grow about 1 mm. The mode I transition points were found to be longer when surface tractions are higher or bulk stress is lower. Before the crack becomes mode I crack, 'well point' where crack grow about rate is minimum, was detected under every experimental condition. The crack behaviour was found to be affected by surface tractions, contact area, bulk stress. It was also found that partial slip and stick condition is most detrimental and the crack starts from the boundary of stick and slip. For gross slip crack started at the outside edge of pad. After crack mode transition, fretting fatigue cracks showed almost same behaviour of plain mode I fatigue cracks. Equivalent stress intensity factor was used to analyze the behaviour of fretting fatigue cracks and it was found that stress intensity factors can be applied to fretting fatigue cracks.

VR 콘텐츠를 이용한 신체검사 개발 및 사용자 만족도 연구 (A Study on the Development of Physical Examination with VR Content and User Satisfaction)

  • 안호원;김준민
    • 한국콘텐츠학회논문지
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    • 제21권6호
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    • pp.318-326
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    • 2021
  • 본 연구는 고령화 및 저출산에 따라 보건의료분야의 만성질환의 증가 및 전문 인력부족 등의 문제를 해결하고 효율적인 헬스케어를 제공하고자 VR 콘텐츠를 이용한 신체검사의 효과성을 연구하였다. 이에 본 연구는 HTC VIVE Pro VR과 스틱 컨트롤러를 착용하여 원스톱 VR 콘텐츠 신체검사 시스템을 구현하였다. 시스템은 1단계부터 5단계까지이며, 색각테스트, 기억력테스트, 청력테스트, 반응속도테스트, 순간인지능력테스트의 5단계를 순차적으로 거쳐 최종 신체 나이를 판별하는 솔루션으로 구성된다.또한 본 연구가 개발한 원스톱 VR 콘텐츠 신체검사 시스템에 대해 대전 소재 A 상급종합병원 건강검진센터 및 VR/AR 임상시험 센터에 내원한 정상인을 대상으로 사용자 만족도를 검증한 결과, 전체적인 만족도와 재이용의사가 높게 나타났고, 성별에 따라 5단계 순간인지테스트는 유의한 차이가 있었으며, 연령에 따라서 4단계 반응속도테스트, 5단계 순간인지테스트에서 유의한 차이가 나타났다.

오일교환경보 알고리즘 및 표시장치 개발 (Development of Oil Change Warning Algorithm and Display Device)

  • 전상명
    • Tribology and Lubricants
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    • 제30권3호
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    • pp.168-176
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    • 2014
  • This paper presents an engine oil change warning algorithm based on the test results of a small dip-stick-gage-type engine-oil-deterioration-detection sensor, software to realize the algorithm and a display device to apply the software. The algorithm determines the engine oil deterioration condition from the rate of change in the dielectric constant based on the average measured capacitance at $80^{\circ}C$ after the engine stops. The rate of change in the dielectric constant at the time for oil change correlates with the time that one of recommended warning limits for engine oil physical properties such as TAN (Total Acid Number), TBN (Total Base Number) and viscosity is first reached. At this point, a warning signal for oil change appears on the display device like a smart-phone or individual display device. The frames of smartphone app have three stages. The user can directly input all of the thresholds into the frame of the smartphone app. The screen of the display device comprises one frame for each warning signature with the related message. The user can input the thresholds to the device through a USB cable connected to a personal computer.