• 제목/요약/키워드: reduced pressure

검색결과 2,670건 처리시간 0.033초

Hull-form optimization of KSUEZMAX to enhance resistance performance

  • Park, Jong-Heon;Choi, Jung-Eun;Chun, Ho-Hwan
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제7권1호
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    • pp.100-114
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    • 2015
  • This paper deploys optimization techniques to obtain the optimum hull form of KSUEZMAX at the conditions of full-load draft and design speed. The processes have been carried out using a RaPID-HOP program. The bow and the stern hull-forms are optimized separately without altering neither, and the resulting versions of the two are then combined. Objective functions are the minimum values of wave-making and viscous pressure resistance coefficients for the bow and stern. Parametric modification functions for the bow hull-form variation are SAC shape, section shape (U-V type, DLWL type), bulb shape (bulb height and size); and those for the stern are SAC and section shape (U-V type, DLWL type). WAVIS version 1.3 code is used for the potential and the viscous-flow solver. Prior to the optimization, a parametric study has been conducted to observe the effects of design parameters on the objective functions. SQP has been applied for the optimization algorithm. The model tests have been conducted at a towing tank to evaluate the resistance performance of the optimized hull-form. It has been noted that the optimized hull-form brings 2.4% and 6.8% reduction in total and residual resistance coefficients compared to those of the original hull-form. The propulsive efficiency increases by 2.0% and the delivered power is reduced 3.7%, whereas the propeller rotating speed increases slightly by 0.41 rpm.

여성노인들의 라인댄스 활동이 정적 직립 균형성에 미치는 영향 (Influence of the Silver Line Dance Effects on the Elderly Balance During Static Standing)

  • 최윤선
    • 한국콘텐츠학회논문지
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    • 제14권9호
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    • pp.120-130
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    • 2014
  • 이 연구는 여성 노인들에게 15주간 라인 댄스 운동 프로그램을 실시하게 한 후 자세 제어와 반응 메커니즘을 관찰할 목적으로 균형성 요인을 분석해 낙상 예방을 위한 운동 중재 효과를 규명하고자 했다. 이를 위해 65세 이상 16명이 선정되었다. 균형성 판단 요인은 정적 직립 상태에서 압력 판에서 25초 서있는 동안 압력 판의 6가지(3방향 힘, 3방향 모멘트) 자료를 수집해 이를 바탕으로 좌우 및 전후 압력중심 변동폭, 이들의 압력 중심 속도, 흔들림 면적을 분석했다. 분석한 결과 라인 댄스 활동 후 전후 압력 중심의 변화 범위(p<.01)와 압력 중심의 평균 속도(p<.05)는 크게 감소를 보였다. 또한 흔들림 면적은 라인댄스 후 유의한 감소를 보였다(p<.001). 좌우 방향의 압력중심 범위와 속도는 큰 감소를 보이지 않았다. 앞으로 이와 유사한 연구를 수행하고자 할 때는 운동 중재 효과를 실제 낙상과 관련해 연구할 필요가 있으며, 또한 균형성 판단 요인을 신체계뿐만 아니라 전정계, 감각계 등을 관찰하는 연구가 필요하리라 본다.

Trichostatin A Modulates Angiotensin II-induced Vasoconstriction and Blood Pressure Via Inhibition of p66shc Activation

  • Kang, Gun;Lee, Yu Ran;Joo, Hee Kyoung;Park, Myoung Soo;Kim, Cuk-Seong;Choi, Sunga;Jeon, ByeongHwa
    • The Korean Journal of Physiology and Pharmacology
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    • 제19권5호
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    • pp.467-472
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    • 2015
  • Histone deacetylase (HDAC) has been recognized as a potentially useful therapeutic target for cardiovascular disorders. However, the effect of the HDAC inhibitor, trichostatin A (TSA), on vasoreactivity and hypertension remains unknown. We performed aortic coarctation at the inter-renal level in rats in order to create a hypertensive rat model. Hypertension induced by abdominal aortic coarctation was significantly suppressed by chronic treatment with TSA (0.5 mg/kg/day for 7 days). Nicotinamide adenine dinucleotide phosphate-driven reactive oxygen species production was also reduced in the aortas of TSA-treated aortic coarctation rats. The vasoconstriction induced by angiotensin II (Ang II, 100 nM) was inhibited by TSA in both endothelium-intact and endothelium-denuded rat aortas, suggesting that TSA has mainly acted in vascular smooth muscle cells (VSMCs). In cultured rat aortic VSMCs, Ang II increased p66shc phosphorylation, which was inhibited by the Ang II receptor type I ($AT_1R$) inhibitor, valsartan ($10{\mu}M$), but not by the $AT_2R$ inhibitor, PD123319. TSA ($1{\sim}10{\mu}M$) inhibited Ang II-induced p66shc phosphorylation in VSMCs and in HEK293T cells expressing $AT_1R$. Taken together, these results suggest that TSA treatment inhibited vasoconstriction and hypertension via inhibition of Ang II-induced phosphorylation of p66shc through $AT_1R$.

돼지머리편육 제조시 삶는 시간 조건에 따른 제품의 이화학적 특성 변화 (Changes of Physico-chemical Characteristics of Pyunyuk Depending on Cooking Time during Processing)

  • 김윤지;이남혁
    • 한국식품영양과학회지
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    • 제27권4호
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    • pp.668-674
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    • 1998
  • Physico-chemical qualities of pyunyuk depending on the cooking time were evaluated to produce high quality and to reduce labor and processing time. Pork headmeat divided into two parts was cooked for 1~4hrs, trimmed and pressed with 110kg/$\textrm{cm}^2$(gauge pressure) for 3.5hrs at 1$0^{\circ}C$. The contents of general nutrients, yield, texture, color, fatty acid composition, gel structure, and sensory evaluation were observed. Deboning time was very dependent on cooking time. Optimum cooking time observed in this study was 2~2.5hrs for efficiency of deboning and yield. Excess cooking time resulted in low yield and working efficiency. Yield variation depending on the cooking time was 14.3~26.0% and it was reduced by increasing the cooking time. The content of moisture was 53.5~54.8% which was not significantly different by cooking time. The content of crude fat was 14.2~26.0% which was decreased by increasing the cooking time. The contents of crude protein(21.1~26.3%) and mineral(1.4~2.7%) were increased by increasing the cooking time. The color of pyunyuk was significantly different by cooking time(p<0.05). In the texture, hardness and chewiness of the pyunyuk cooked for 2hrs were significantly higher than others processed in this study(p<0.05). However cohesiveness and springiness were not different among pyunyuks. With sensory evaluation, hardness was similar among the pyunyuks cooked over 2hrs. The pyunyuk cooked for 1hr showed higher value in juiciness than the pyunyuk cooked for 3~4hrs(p<0.05). The % of saturated fatty acids was decreased by increasing the cooking time, and gel structure of pyunyuk cooked for 2hrs was the most compact among treaments. In conclusion, 2hrs was proper as a cooking time concerned with working efficiency and physico-chemical quality of pyunpyk.

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신정격 및 방광정격 자침이 정상 성인의 맥파 변화에 대한 비교 연구 (The Effects of Sa-am Acupuncture on Radial Pulse in Healthy Human Subjects: A Comparative Study on Tonifications of Kidney and Urinary Bladder)

  • 곽규인;강재희;이현
    • Journal of Acupuncture Research
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    • 제32권2호
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    • pp.105-121
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    • 2015
  • Objectives : The purpose of this study is to observe the effects of Sa-am acupuncture with tonifications of kidney and urinary bladder on radial pulse in healthy subjects. Methods : Sixty healthy subjects participated in this study, and were divided into a kidney tonifying acupuncture group(KI group), urinary bladder tonifying acupuncture group(BL group) and control group. Radial pulse was measured by 3 dimensional pulse imaging system(DMP-3000) before, immediately after, 30 minutes after, and 60 minutes after acupuncture at Cun, Guan, and Chi in each time. Results : 1. BL group exhibited significantly reduced T1 / T, T4 / T, T4 / (T-T4), T5 / T and increased(T-T4) / T compared to KI group. 2. BL group showed increase of radial augmentation index / heart rate(RAI / HR) in left Cun, H5, Ad / Ap in left Chi, H1, As / Ap in right Chi compared to KI group. BL group showed decrease of As / Ap, Aw / Ap in left Chi, H1, pulse depth, Ad / Ap in right Chi compared to KI group. 3. KI group showed increase of Aw / Ap, H1, H2, H4, pulse area in right Guan, pulse depth in right Chi compared to BL group. KI group showed decrease of RAI in left Cun, applied pressure, pulse depth in left Guan, Aw / Ap in right Chi compared to BL group. Conclusions : The effects of Sa-am acupuncture with tonifications of kidney and urinary bladder in healthy humans have been observed on various parameters. The parameters analysed in this study can be used to differentiate the effects of Sa-am acupuncture with tonifications of kidney and urinary bladder on radial pulse.

3.3.5.5 워킹 프로그램이 노인의 건강증진에 미치는 효과 (The Effect of the 3.3.5.5 Walking Club Program to Health Promotion of the Elderly)

  • 민순;임욱빈;김영재;정영주;김경숙;나송숙
    • Journal of Korean Biological Nursing Science
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    • 제10권1호
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    • pp.96-104
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    • 2008
  • Purpose: We had executed the 3 3 5 5 walking club program for 12 weeks for one hour three times per week to evaluate the effect of the program on health of the elderly. Methods: A pre and post measurement tool of the program was applied to measure obesity, rate of body fat, blood pressure, vital capacity, standard vital capacity, intake capacity of maximum oxygen, grasping power, reaction of whole body, pulse, body mass index (BMI), total bodily score, age of bodily strength, age of health. Data collected from this tool was analyzed by SPSS in paired t-test. Results: The 3 3 5 5 walking club program has affected the weight control of the participants. The participants of 3 3 5 5 walking club program reduced their weight from 61.7 kg to 61.25 kg, rate of body fat from 21.89 kg to 21.22 kg, standard vital capacity from 2,393.56 ml to 2,380.44 ml, reaction of whole body from 475.38 msec to 439.33 msec, and increased grasping power from 22.06 to 23.16 ml (p<.05), total bodily score 68.91 points to 71.38 points significantly (p<.05). Conclusion: The result indicated that the 3.3.5.5 Walking club program has an positive effect on improving health care of the elderly without special exercise tools.

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비트 확장을 이용한 전하재분배 방식 ADC의 설계 (Design of a Charge-Redistribution ADC Using Bit Extension)

  • 김규철;도형욱
    • 전기전자학회논문지
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    • 제9권1호
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    • pp.65-71
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    • 2005
  • 실세계에서 발생하는 물리적인 신호는 센서를 통하여 전기적 신호로 바뀌어 전자회로에 입력된다. 입력된 전기적 신호는 아날로그 형태인데 디지털 신호처리를 위해서 아날로그-디지털 변환기 (ADC Analog-Digital Converter)를 사용하여 디지털 신호로 변환시켜야 한다. 실리콘 마이크로 센서와 결합되어 사용되는 신호처리 회로 및 ADC는 단일칩에 구현되기 용이하도록 저전력 및 소면적으로 설계되어야 한다. 본 논문에서는 실리콘 마이크로센서와 단일칩에 구현하기 적합하도록 실리콘 사용 면적을 대폭 줄인 전하재분배 방식의 ADC를 설계하였다. 설계된 방식은 4 비트 변환을 두 차례 수행하여 8 비트 변환을 하는 방식으로 기존 방식에 비해 커패시터 어레이의 면적을 1/16로 줄였다. 연적을 줄인 대신 변환에 사용된 클럭의 수는 2배 정도 증가되었으나 압력센서의 신호는 고속 변환이 요구되지 않으므로 압력센서에 적합하다고 할 수 있다.

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Mg2NiHx 수소화거동에 미치는 기계적합금화 공정의 영향 (The Effect of Planetary Ball Mill Process on the Hydrogenation Behavior of Mg2NiHx)

  • 임재원;하원;홍태환;김세광;김영직;박현순
    • 한국수소및신에너지학회논문집
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    • 제10권2호
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    • pp.131-139
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    • 1999
  • The objective of this works was to synthesize the$Mg_2Ni$ hydrogen storage materials economically and to eliminate the intial activation process. $Mg_2NiH_x$ was mechanically alloyed under purified hydrogen gas atmosphere using pure Mg and Ni chips. M.A(Mechanical Alloying) was carried out using planetary ball mill for times varying from 12h to 96h under 20bars of hydrogen gas pressure. $Mg_2NiH_x$ started to form after 48h and the homogeneous $Mg_2NiH_x$ composites was synthesized after 96h. From TG analysis, the dehydriding reaction of $Mg_2NiH_x$ started at around $200^{\circ}C$. The result of P-C-T at $300^{\circ}C$ revealed the hydrogen storage capacity of $Mg_2NiH_c$ reached 3.68 wt% and the effective hydrogen storage was 2.38 wt%. The enthalpy difference of absorption-desorption cycling for the hydride formation and the hysteresis were reduced and the plateau flatness and the sloping were improved according to M.A time.

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Electrical Characteristics of Organic Light-emitting Diodes Fabricated by Varying a Hole-size in Evaporation Boat

  • Kim, Weon-Jong;Park, Young-Ha;Cho, Kyung-Soon;Hong, Jin-Woong;Shin, Jong-Yeol;Kim, Tae-Wan
    • Transactions on Electrical and Electronic Materials
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    • 제9권3호
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    • pp.105-109
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    • 2008
  • Electrical characteristics of organic light-emitting diodes were investigated by varying a hole-size in evaporation boat in the device structure of ITO/tris(8-hydroxyquinoline) aluminum$(Alq_3)$/Al. The device was manufactured using a thermal evaporation under a base pressure of $5{\times}10^{-6}$ Torr. The $Alq_3$ emitting organics were evaporated to be a thickness of 100 nm at a deposition rate of $1.5{\AA}/s$. A cylindrical-shaped evaporation boat was made out of stainless steel with a small size of hole on top of the boat. Several evaporation boats were made having a different hole size on top; 0.8 mm, 1.0 mm, 1.5 mm, and 3.0 mm. We found that when the hole size on top of the evaporation boat is 1.0 mm, the average roughness is rather smoother compared to the other ones. Also, luminance and external quantum efficiency are superior to the others. Compared to the ones from the devices made with the hole-size of 0.8 mm boat. The luminance and external quantum efficiency of the device made with the hole-size of 1.0 mm boat were improved by a factor of seventy and thirty three, respectively. Also operating voltage is reduced to 2 V.

신축공동주택의 기밀성능 실측에 관한 연구 (The Field Measurement of Airtightness in the Apartment Buildings)

  • 박원석;윤재옥
    • KIEAE Journal
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    • 제3권3호
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    • pp.43-50
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    • 2003
  • Nowdays the apartment is a main type of modernized residential buildings. According to the improvement of construction techniques and functions of windows and doors, recent apartments are enhanced air tightness of windows, doors and building envelopes. As Infiltration is decreased and natural ventilation is reduced, energy could be saved in winter. However, indoor air quality is bad. The air Infiltration of a building could be enlarged by physical actions, such as building designs, constructions and reduction of air tightness which is caused by aging. This research analyzes and measures with KNS-4000P (Sapporo air tightness measurement) the air tightness of the high rise apartments which is recently constructed and not occupied yet. With depressurization method, the KNS-4000 installed on the window and the indoor air-leakage was measured. At that time, Air come out from the edge of the windows and doors because of the pressure differences between indoor and outdoor. We measure the amount of the air as effective air leakage areas. This method of depressurization takes less time to measure than other methods and is less affected from other conditions. We measured infiltration of total 56 household, 29 households S apartment (total floor area : $64.42m^2$) in Balan and 29 households D apartment(total floor area : $78.21m^2$) in Chonan. As a result of the field measurements at October 2003, normalized leakage area of D apartment in Cheonan was $2.05cm^2/m^2{\sim}3.49cm^2/m^2$ (average: $2.77cm^2/m^2$) and normalized leakage area of S apartment in Balan is $1.23cm^2/m^2{\sim}1.68cm^2/m^2$ (average: $1.5cm^2/m^2$).