• 제목/요약/키워드: Release speed

검색결과 264건 처리시간 0.028초

디젤기관에 있어서 흡기습도 변화가 연소 특성과 배기배출물 특성에 미치는 영향 (Effects of Suction Air Humidity on the Combustion and Exhaust Emissions Characteristics in Diesel Engine)

  • 임재근;김동호
    • Journal of Advanced Marine Engineering and Technology
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    • 제24권4호
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    • pp.421-426
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    • 2000
  • A study on the combustion and exhaust emissions characteristics of diesel engine with various suction air humidity is performed experimentally. In this paper, suction air humidity is changed from RH 50% to RH 90%, the experiments are performed at engine speed 1800rpm, and main measured parameters are cylinder pressure, fuel consumption rate, CO, HC, NOx and Soot emissions etc. Increase of suction air humidity from RH 50% to RH 90% does not effect specific fuel consumption, decreases maximum pressure in cylinder, ratio of maximum pressure rise and net heat release, and delays ignition timing. Also, that increases CO and HC emissions, decreases NOx emissions, but does not constant in changing tendency on emission.

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지속성 제제의 개발에 관한 연구 (I) 아스코르빈산 나트륨의 CAP 마이크로캅셀의 제조 및 평가 (Studies on the Development of Sustained Release Preparation (I) Preparation and Evaluation of CAP Microcapsules of Sodium Ascorbate)

  • 신상철;고익배
    • Journal of Pharmaceutical Investigation
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    • 제21권4호
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    • pp.253-262
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    • 1991
  • Microencapsulation of sodium ascorbate with cellulose acetate phthalate(CAP) by coacervation/ phase separation method were carried out. Various factors affecting microencapsulation, i.e., surfactant concentration. CAP concentration, stirring speed and treatment of spermaceti as a sealing agent were studied. Dissolution rate. particle size distribution, surface feature and stability test were investigated. CAP microcapsules prepared using 0.5% span 80 as a surfactant showed smooth and round surfaces. The release of sodium ascorbate was retarded by microencapsulation with CAP and by sealant treatment with spermaceti. When triturated with sodium bicarbonate, CAP microcapsules were more stable than unencapsulated sodium ascorbate under various RH conditions at $37^{\circ}C$.

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전자제어식 직접분사 디젤 엔진 연소실내의 분무연소 특성에 관한 연구 (A study on the spray combustion characteristics in a cylinder of a D.I.diesel engine with the electronically controlled injector)

  • 정재우;김성중;이기형;선우명호
    • 한국자동차공학회논문집
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    • 제8권2호
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    • pp.50-56
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    • 2000
  • It is well known that the combustion phenomenon of diesel engine is an unsteady turbulent diffusion combustion. Therefore, the combustion performance of diesel engine is related to a complex phenomenon which involves the various factors of combustion, such as a injection pressure, injection timing, injection rate, and operation conditions of engine. In this study, the spray and the flame development processes in a single cylinder D.I. diesel visualization engine which uses the electronically controlled injection system were visualized to interpret the complicated combustion phenomenon by using high speed CCD camera. In addition, the cylinder pressure and heat release rate were also obtained in order to analyze the diesel combustion characteristics under several engine conditions.

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진해만 입구에 방류한 대구(Gadus macrocephalus)의 행동 분석 (Behavioral analysis of Pacific cod (Gadus macrocephalus) released to the entrance of Jinhae Bay, Korea)

  • 신현옥;허겸;허민아;강경미
    • 수산해양기술연구
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    • 제55권1호
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    • pp.29-38
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    • 2019
  • In order to investigate the behavioral characteristics of Pacific cod (Gadus macrocephalus) released at the entrance of Jinhae Bay, Korea, the direction and range of movement, swimming speed of the fish were measured with an acoustic telemetry techniques in winter, 2015. Three wild Pacific codes WC1 to WC3 (total length 66.0, 75.0, 76.0 cm; body weight 2.84, 2.79, 3.47 kg, respectively) were tagged with the acoustic transmitter. WC1 tagged with an acoustic transmitter internally by surgical method, WC2 and WC3, externally with the acoustic data logger and a micro data logger for recording audible sound waves including timer release unit. The movement routes of the tagged fish were measured more than five hours using VR100 receiver and a directional hydrophone. The directionality of the fish movement was tested by Rayleigh's z-Test, the statistical analysis, and a statistical program SPSS. Three tagged fishes were individually released on the sea surface around the entrance to the Jinhae Bay on 10 to 24 January 2015. WC1 moved about 13.32 km with average swimming speed of 0.63 m/s for six hours. The average swimming depth and water depth of the seabed on the route of WC1 were 7.2 and 32.9 m, respectively. The movement range of WC2 and WC3 were 7.95 and 11.06 km, approximately, with average swimming speed of 0.44 and 0.58 m/s for 5.1 and 5.3 hours, respectively. The average swimming depth of WC2 and WC3 were 18.7 and 5.0 m, and the water depth on the route, 34.4 and 29.8 m, respectively. Three fishes WC1 to WC3 were shown significant directionality in the movement (p < 0.05). Movement mean angles of WC1 to WC3 were 77.7, 76.3 and $88.1^{\circ}$, respectively. There was no significant correlation between the movement direction of fish (WC1 and WC2) and the tidal currents during the experimental period (p >= 0.05). Consequently, three tagged fishes were commonly moved toward outside of the entrance and headed for eastward of the Korean Peninsula, approximately, after release. It may estimate positively that the tidal current speed may affect to the swimming speed of the Pacific cod during the spring tide than the neap tide.

막유화법에 의한 생분해성 Polycaprolactone 마이크로캡슐의 제조와 약물방출 특성 (Preparation of Polycaprolactone Microcapsules by Membrane Emulsification Method and Its Drug Release Properties)

  • 염경호;윤태호;김공수;조석형
    • 멤브레인
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    • 제17권1호
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    • pp.67-79
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    • 2007
  • SPG (Shirasu porous glass) 관형 막이 설치된 회분식 막유화 장치를 사용하여 이온성 약물이 담지된 단분산 polycaprolactone (PCL) 마이크로캡슐을 제조하기 위한 막유화 공정변수의 최적조건을 결정하였다. 마이크로캡슐에 담지된 이온성 약물로는 양이온성인 lidocaine-hydrochloride, 중성인 sodium salicylate와 음이온성인 4-acetaminophen의 3가지를 사용하였으며, PCL 마이크로캡슐로부터 이들 모델약물의 방출거동을 검토하였다. 캡슐제조에 사용된 PCL의 농도와 분자량, 막간 압력차, 분산상과 연속상에 첨가시킨 유화제의 농도, 연속상의 교반속도가 막유화법으로 제조된 PCL 캡슐의 크기와 크기분포에 미치는 영향을 검토하였다. 이들 공정변수의 조절을 통해 평균 크기 약 $5\;{\mu}m$의 균일한 마이크로캡슐을 제조할 수 있었다. 약물 방출실험 결과 산성조건에서 알칼리조건으로 방출환경이 변화됨에 따라 약물 방출속도가 증가하였다.

Polyethylene Glycol 처리한 아크릴 운동용 양말의 축열 . 방열성과 수분전달 특성이 착용 성능에 미치는 영향 (The Effect of Thermal Storage/Release and Moisture Transport Properties of Polyethylene Glycol-Treated Acrylic Athletic Socks on the Wear Performance)

  • 조길수;이은주
    • 한국의류학회지
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    • 제19권1호
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    • pp.36-50
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    • 1995
  • The purpose of this study was 1) to estimate the improvement of thermal storage/release and moisture transport properties of PEG-treated acrylic athletic socks and suggest the optimum add-on for PEG treatment, 2) to investigate wear performance of untreated cocks and two kinds of socks treated with PEG of minimum and optimum add-on respectively, and 3) to consider the effect of thermal storage/release and moisture transport properties of PEG- treated socks on the wear performance and the subjective comfort zone. Thermal activities of specimens treated by PDC were evaluated on a DSC by measuring the heat of fusion on heating and the heat of crystallization on cooling. Moisture regain, absorption speed, wickability, water retenti on value, and water-vapor permeability were measured. In the wear trials that the subjects performed a subsequent exercise protocol wearing three differently treated socks in a conditioned environment ($14\pm2^{\circ}C$, 65$\pm$2% R.H.), microclimate temperature and humidity, and subjective wear sensations including thermal sensation, wettedness, softness, fit, and overall comfort were obtained. PEC-treated specimens with more than 20% add-on showed thermal storage on heating and thermal release on cooling by a DSC and the heat contents of treated ones were generally proportional to the add-ons. Moisture transport properties were highly improved after PEG treatment and increased rapidly with increasing add-on. The tendencies were, however, relaxed above 50% add-on and the treated knits were much stiffer above that add-on. In the wear trials of untreated, PEG add-on 20%, and 50% acrylic socks, the changes of microclimate temperature of 50% socks were significantly less than that of 20% socks. PEG add-on 50% socks showed significantly less changes of microclimate humidity than other two kinds of socks. Three kinds of socks showed significant differences in overall comfort and add-on 50% socks were accepted more comfortable than other two kinds of socks. Comfort zone of foot was extended after PEG treatment on socks and it implied that the subjects wearing PEG- treated socks felt comfortable in wider ranges of microclimate temperature and humidity.

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가교된 키토산으로 형성된 마이크로캡슐의 제조 및 방출 특성 (Preparation and Controlled Release Characterization of Crosslinked Chitosan Microcapsules)

  • 한아름;신영재;이천일;표형배;신재섭
    • 접착 및 계면
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    • 제9권2호
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    • pp.8-15
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    • 2008
  • 마이크로캡슐은 다양한 기능성 물질의 약물 전달 시스템으로서 화장품과 제약 분야에서 널리 적용되고 있다. 키토산은 천연에 풍부하게 존재하는 생체고분자로 생체적합성이 우수하며 무독성이다. 본 연구에서는 키토산 마이크로캡슐을 글루타르알데히드를 가교제로 사용하여 W/O 형태의 유화법으로 제조하였다. 유화제로는 span80을 사용하였으며 가교가 시행되는 bath상의 물질은 mineral oil을 사용하였다. 제조된 키토산 마이크로캡슐은 완벽한 구의 형태로 평균 $2{\sim}10{\mu}m$ 크기를 보였으며, 교반속도와 유화제의 농도에 따른 캡슐의 직경 및 형태 변화를 관찰하였다. 마이크로캡슐의 방출실험을 하기 위하여 가교제, 키토산, 그리고 유화제의 양을 변화시키면서 방출 속도를 측정하였다. Riboflavin의 방출속도는 키토산의 가교 정도와 사용한 유화제의 양에 따라 크게 변하였다.

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여자 창던지기 운동학적 요인의 일관성 평가 (Evaluation of Consistency on Kinematic Factors in Women Javelin Throw)

  • 홍순모;이영선
    • 한국운동역학회지
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    • 제17권4호
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    • pp.65-71
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    • 2007
  • The purpose of this study was to investigate variability of kinematic factors affecting the record in women's javelin throwing. For this study, 8 female-javelin thrower participated in this experiment. The three digital video cameras (Sony, 120x) were used to record motions. Kwon3D 2.1 was used to process data and they were analyzed with Excell for factors. The sampling rate of a camera was 60Hz and shutter speed of a camera was 1/1000sec. The coordinate data were filtered using a fourth-order Butterworth low pass filtering with an estimated optimum cut-off frequency of 6Hz. The results were as follows: 1. From cross step to landing of delivery, the average velocities of CoM of non-dominant athletes were greater than dominant athletes and those of CoM of non-dominant athletes less than dominant athletes, but at release dominant athletes had a lower average velocity and a variability than non-dominant athletes. 2. From cross step to landing of delivery, the average throwing velocities and variabilities of a javelin of dominant athletes were greater than dominant athletes, but at release, dominant athletes had a higher velocity than dominant athletes and had a equal variability. 3. At every events, a forward or backward angles and variabilities of non-dominant athletes were greater than dominant athletes. 4. From cross step to landing of delivery, dominant athletes' elbow average angles were greater than non-dominant athletes and the variabilities of latter less than non-dominant athletes, but at release dominant athletes' variabilities were smaller than non-dominant athletes. 5. At landing of delivery, dominant athletes' knee average angles and variabilities of a supporting foot were a greater than non-dominant athletes, and at release, dominant athletes' knee average angles was a greater but variabilities less than non-dominant athletes. In conclusion, the dominant threw javelins fast while having stable postures and the range of elbow's angle large.

Preparation of Controlled Release Spheronized Beads by a Simple Extrusion and Modified Spheronization Process

  • Lee, Si-Beum;Kim, Min-Soo;Jun, Seoung-Wook;Park, Jeong-Sook;Hwang, Sung-Joo
    • Archives of Pharmacal Research
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    • 제28권5호
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    • pp.619-625
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    • 2005
  • Beads loaded with the water-soluble drug, phenylpropanolamine HCl (PPA), were prepared using an extruder and double arm counter-rotating roller modified from a traditional pill machine. The mean diameter of the cylindrical rod-like extrudate from the ram extruder was 3 mm; that of the uncoated bead after cutting and spheronization by the modified double arm counter-rotating roller was 3.26~3.28 mm. Although the surface of the beads was moderately rough and irregular, some exhibited hump-shaped protrusions, the sphericity was acceptable (roundness 1.15) and adequate for the subsequent coating process. An increase in mean diameter of the coated beads and improvements in friability and sphericity were observed in proportion to the amount of coating material applied (ethylcellulose or Eudragit?? RS 100). It was also found that the release rate of PPA from the coated beads could be controlled by the amount and type of coating materials applied or with the incorporation of Eudragit ?? RS 100 into the core matrix. Further modifications to the double arm counter-rotating roller, including adjustment of the rotation speed and distance between the rollers, would yield smaller uncoated beads with improved roundness and surface roughness. In conclusion , the present method could be potentially applied to prepare controlled release drug delivery beads or pellet dosage forms.

장대높이뛰기 경기의 운동학적 분석 (Kinematical Analysis of Men's Pole Vault Event)

  • 임규찬
    • 한국운동역학회지
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    • 제13권3호
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    • pp.15-26
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    • 2003
  • This study was conducted to investigate the performance times, CM position and CM speed, pole chord length and pole chord angle, whole body angular momentum(X axis), and grip width in pole vault event according to the event and phase; touch down, pole plant, take-off, maximum pole bending pole straight, pole release, peak height, and foot contact, pole contact, free flight. The pole vaulting of four male elite vaulters including six trial were filmed using two video digital cameras at 60 Hz at 56th national athletic match, and data were collected through the DLT method of three dimensional cinematography. In general the better jumper is, the longer the performance time is. And the greater CM speed is, and the better his transformation ability of CM horizontal speed into vertical speed is. As he uses a longer pole, his grip is higher, and it is a enough for him to rock back his body, so that he pulls and pushes the pole well keeping his hips close to. An greater maximum angular momentum and early positioning of the hips parallel to the bar makes his body far side of the bar and his bar clearance easier. Specially our national jumper needs to have more powerful braking force during foot contact phase, and take his body on the pole after maximum pole bending, and pull and push the pole strongly keeping his hips close to. Also he needs to have stronger muscular strength in order to control the longer pole and use the pole of proper tension more efficiently.