• 제목/요약/키워드: Local circulation

검색결과 311건 처리시간 0.031초

자기공명영상을 이용한 찜질 자극에 의한 통증 완화 효과에 대한 혈류 영상학적 고찰 (The Study of Vascular Dynamics for the Effect of a Compress Pack on Pain Relief using Magnetic Resonance Angiography)

  • 백지원;임영기
    • Journal of Radiation Protection and Research
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    • 제40권4호
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    • pp.277-282
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    • 2015
  • 본 연구는 찜질 자극이 국소 통증을 완화시킬 뿐만 아니라 편두통과 같은 만성 질환의 통증 완화에 효과적으로 애용되고 있는 이유에 대한 근거를 혈류 역학적인 측면에서 고찰하고자 한다. 이를 위해 찜질 자극에 의한 자극 부위에서의 국소 혈류 변화가 일어나는 것을 관측하고, 이를 통해 두개 내 외부의 혈액 순환에 어떠한 변화를 야기하는지를 정상인 피험자 (n=8, 평균나이: $32.13{\pm}4.61$) 를 대상으로 자기공명영상 시스템을 이용하여 관측하였다. 국소 혈류변화는 찜질 자극에 의한 피부 색깔 및 온도 변화를 통하여 관측하고자 하였고, 두개 내 외부 혈관의 자극에 따른 변화를 자기공명혈관조영술을 통해 관측하고 영상을 분석하여 비교하고자 하였다. 찜질 자극 전 $36.4^{\circ}C$에서 자극 15분 후 $36.7^{\circ}C$, 그리고 자극 30분 후 $37.1^{\circ}C$ 로 피부온도가 상승한 것으로 나타났으며, 찜질 자극이 시작되는 시점과 자극 30분 후의 혈관 영상 분석 결과를 살펴보면 두개 내부 혈관에서는 유의한 변화를 보이지 않은 반면, 두개 외부 혈관에서는 찜질 자극 후 상당한 혈류 신호의 변화를 보여주었다(+38.8%). 결과에서 보듯이 찜질 자극 부위의 이러한 국소 온도의 변화와 두개 외의 혈류의 변화를 통하여 찜질 자극이 국소적으로는 근육 통증 및 편두통과 같은 만성질환의 통증을 완화시키는 효과를 발휘하고 더 나아가 혈액 순환을 촉진시키는 작용을 통하여 전신에 미치는 결림 현상 및 통증의 완화에 실질적으로 효과를 보일 수 있게 되는 것으로 사료된다.

경매를 활용한 근거리 분할 물류운영이 물류비용에 미치는 영향에 관한 연구 (A Study on the Effects of Auction-Based Short Distance Division Logistics Operation on Logistics Costs)

  • 김병찬
    • 디지털산업정보학회논문지
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    • 제12권3호
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    • pp.299-309
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    • 2016
  • This study proposed a logistics plan for sending supply to be distributed to areas other than producing areas to wholesalers and allocating supply to be distributed to areas near producing areas to local distribution center in the vicinity instead of shipping the entire quantity to wholesalers for fruits auction to increase the competitive edge of the domestic fruits and vegetables logistics market in the ear of infinite competition. A video auction-based short distance division logistics operation model was developed to enhance competitiveness related to the circulation of fruits and vegetables, reduce logistics costs, and rationalize logistics by distributing the items sent to wholesalers through field auction and the shipments at local distribution center to neighboring areas through video auction connected to wholesalers real-time. The study especially came up with a logistics rationalization plan by examining and analyzing the stages and costs of transportation between producing areas and wholesalers on the circulation routes of fruits.

도시지역의 국지순환과 침적현상에 관한 수치모의 (Numerical Simulation for Local Circulation of Urban Area and Deposition Phenomenon)

  • 이화운;오은주;노순아;반수진
    • 한국대기환경학회지
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    • 제19권6호
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    • pp.773-787
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    • 2003
  • There are variations in the temperature Held due to urban heat island and anthropogenic heating so that regional scale meteorological field is changed. Therefore we simulate and predict the regional climate change according to surface characteristics through regional meteorological model. This study investigates the regional meteorological field by urbanization that influences in local circulation system using CSU-RAMS and simulates dry deposition velocity (V$_{d}$) using PNU/DEM which includes surface characteristics (such as albedo, surface hydrology and rough-ness length etc.) with calculated meteorological field. During the summer, horizontal distributions of V$_{d}$ were simulated using CSU-RAMS and PNU/DEM at Busan metropolitan area. The estimated values of V$_{d}$ were larger in forest and agricultural areas than water areas since ozone with low water solubility is destroyed slowly at wet surface or water.water.

경피기주입술(Carboxytherapy)에 대한 문헌적 고찰 (Review of Literature on Chi Acupunture(Carboxytherapy))

  • 심우진;송재철;이종수;신현택
    • 한방비만학회지
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    • 제6권2호
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    • pp.43-49
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    • 2006
  • Objective : This study was conducted to offer basic materials for the clinical study of Chi acupuncture (carboxytherapy). Methods : Recent clinical studies were reviewed for carboxytherapy (carbon dioxide therapy) and the ancient and present texts were reviewed for Chi acupuncture. Results and Conclusions : Chi acupuncture is oriental medical therapeutic treatment using carboxytherapy. Chi acupuncture refers to the transcutaneous administration of CO2 gas for therapeutical purposes relating to obesity, cellulites, local circulation and skin irregularity. Recent studies have demonstrated the effects of this therapy on adipose tissue by showing vasomotor effects, increasing local circulation and inducing a partial increase in tcPO2. Chi acupuncture influences the microcirculation and likely has a positive effect upon the physiological oxidative lipolytic process.

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연안부근 복잡지형의 대기유동장 수치실험 II -부산광역지역에 대한 국지순환모형의 적용- (A Numerical Experiments on the Atmospheric Circulation over a Complex Terrain around Coastal Area. Part II :)

  • 김유근
    • 한국대기환경학회지
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    • 제16권2호
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    • pp.151-158
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    • 2000
  • Since Pusan metropolitanarea where is composed complex terrain is connected to sea the sea-land breeze circulation and the mountain-valley circulation are apt to form A regional scale circulation system is formed at a region which has complex terrain because of curves of its and affect to the dispersion and advection of air pollutants. LCM Local Circulation Model which a propriety was verified described that sea breeze and valley wind at the daytime and land breeze and mountain wind at the nighttime were well devellped over the Pusan metropolital area. Next for the investigation of accuracy of simulated results an observed value at Kae-Kum and Su-Young on the pusan metropolitan area were compared with it at those points. From the comparison of the temperature and horizontal velocity between the results of LCM and an observed values they have a similar trend of a diurnal variation. For the prediction of dispersion and transportation of air pollutants the wind field should be calculated with high accuracy. A numerical simulation using LCM can provide more accuracy results around Pusan metropolitan area.

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Experimental investigation of two-phase natural circulation loop as passive containment cooling system

  • Lim, Sun Taek;Kim, Koung Moon;Kim, Haeseong;Jerng, Dong-Wook;Ahn, Ho Seon
    • Nuclear Engineering and Technology
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    • 제53권12호
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    • pp.3918-3929
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    • 2021
  • In this study, we experimentally investigate of a two-phase natural circulation loop that functions as a passive containment cooling system (PCCS). The experimental apparatus comprises two loops: a hot loop, for simulating containment under severe accidents, and a natural circulation loop, for simulating the PCCS. The experiment is conducted by controlling the pressure and inlet temperature of the hot loop in the range of 0.59-0.69 MPa (abs) and 119.6-158.8 ℃, respectively. The heat balance of the hot loop is established and compared with a natural circulation loop to assess the thermal reliability of the experimental apparatus, and an additional system is installed to measure the vapor mass flow rate. Furthermore, the thermal-hydraulic characteristics are considered in terms of a temperature, mass flow rate, heat transfer coefficient (HTC), etc. The flow rate of the natural circulation loop is induced primarily by flashing, and a distortion is observed in the local HTC because of the fully develop as well as subcooled boiling. As a result, we present the amount of heat capacity that the PCCS can passively remove according to the experimental conditions and compared the heat transfer performance using Chen's and Dittus-Boelter correlation.

Effects of decay heat and cooling condition on the reactor pool natural circulation under RVACS operation in a water 2-D slab model

  • Min Ho Lee ;Dong Wook Jerng ;In Cheol Bang
    • Nuclear Engineering and Technology
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    • 제55권5호
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    • pp.1821-1829
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    • 2023
  • The temperature distribution of the reactor pool under natural circulation induced by the RVACS operation was experimentally studied. According to the Bo' based similarity law, which could reproduce the temperature distribution of the working fluid under natural circulation, SINCRO-2D facility was designed based on the PGSFR. It was reduced to 1 : 25 in length scale, having water as a simulant of the sodium, which is the original working fluid. In general, temperature was stratified, however, effect of the natural circulation flow could be observed by the entrainment of the stratified temperature. Relative cooling contribution of the upper plenum (narrow gap) and lower plenum was approximately 0.2 and 0.8, respectively. In the range of decay heat from 0.2% to 1.0%, only the magnitude of the temperature was changed, while the normalized temperature maintained. Boundary temperature distribution change made a global temperature offset of the pool, without a significant local change. Therefore, the decay heat and cooling boundary condition had no significant effect on temperature distribution characteristics of the pool within the given range of the decay heat and boundary temperature distribution.

지형자료 해상도에 따른 대기 유동장 변화에 관한 수치 연구 (Numerical Study on Atmospheric Flow Variation Associated With the Resolution of Topography)

  • 이순환;김선희;류찬수
    • 한국환경과학회지
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    • 제15권12호
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    • pp.1141-1154
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    • 2006
  • Orographic effect is one of the important factors to induce Local circulations and to make atmospheric turbulence, so it is necessary to use the exact topographic data for prediction of local circulations. In order to clarify the sensitivity of the spatial resolution of topography data, numerical simulations using several topography data with different spatial resolution are carried out under stable and unstable synoptic conditions. The results are as follows: 1) Influence of topographic data resolution on local circulation tends to be stronger at simulation with fine grid than that with coarse grid. 2) The hight of mountains in numerical model become mote reasonable with high resolution topographic data, so the orographic effect is also emphasized and clarified when the topographic data resolution is higher. 2) The higher the topographic resolution is, the stronger the mountain effect is. When used topographic data resolution become fine, topography in numerical model becomes closer to real topography. 3) The topographic effect tends to be stronger when atmospheric stability is strong stable. 4) Although spatial resolution of topographic data is not fundamental factor for dramatic improvement of weather prediction accuracy, some influence on small scale circulation can be recognized, especially in fluid dynamic simulation.