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A Numerical Study on the Smoke Behavior by Solar Radiation through Ceiling Glass in Atrium Fires

  • Jeong, Jin-Yong
    • International Journal of Air-Conditioning and Refrigeration
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    • v.10 no.3
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    • pp.117-128
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    • 2002
  • This paper describes the smoke filling process of a fire field model based on a self-deve-loped SMEP (Smoke Movement Estimating Program) code to the simulation of fire induced flows in the two types of atrium space containing a ceiling heat flux. The SMEP using PISO algorithm solves conservation equations for mass, momentum, energy and species, together with those for the modified k-$\varepsilon$ turbulence model with buoyancy production term. Also it solves the radiation equation using the discrete ordinates method. Compressibility is assumed and the perfect gas law is used. Comparison of the calculated upper-layer average tempera-ture and smoke layer clear height with the zone models has shown reasonable agreement. The zone models used are the CFAST and the NBTC one-room. For atrium fires with ceiling glass the ceiling heat flux by solar heat causes a high smoke temperature near the ceiling. However, it has no effect on the smoke movement such as the smoke layer clear heights that are important in fire safety. In conclusion, the smoke layer clear heights that are important in evacuation activity except the early of a fire were not as sensitive as the smoke layer tem-perature to the nature of ceiling heat flux condition. Thus, a fire sensor in atrium with ceiling glass has to consider these phenomena.

Relation between crown-length, tree-height, diameter Clear-bale length and the longest branch length in a Pinus densiflora stand (적송림(赤松林)에 있어서의 성장인자간(成長因子間)의 상관(相關))

  • Yim, Kyong Bin;Pack, Myong Kyu
    • Journal of Korean Society of Forest Science
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    • v.5 no.1
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    • pp.27-32
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    • 1966
  • Taking an opportunity of the application of clearcutting method, 140 red pine (Pinus densiflora Sieb. et Zucc.) trees grown at Chon-nam province, the southern part of South Korea, were fellen and the tree height, clear-bole length, D.B.H. diameter at base(0.2m above from the ground line) and the length of the longest branch were measured. The correlation between factors mentioned were analysed. The results are summarized as follows: 1. The correlation between crown length and tree height (r=0.821) was sinificant. 2. The correlation between the diameter at base and D.B.H. was highly significant (r=0.961). D.B.H. can be calculated from multiplying the diameter at base by 0.88. 3. A weak relation between D.B.H and tree height was abserved. 4. The positive correlation between tree height and clear-bole-length was calculated, but it was not sharp between D.B.H. and the length of the longest branch. 5. The height, basal area, D.B.H. and volume increment by tree class calculated from the data of the stem analysis are presented (Tab. 3~10).

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On the Warming Effects due to Artificial Constructions in a Large Housing Complex (대규모 주택단지내의 인공구조물에 의한 승온화효과에 관한 연구)

  • 김해동;이송옥;구현숙
    • Journal of Environmental Science International
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    • v.12 no.7
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    • pp.705-713
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    • 2003
  • In mid-August 2002, under clear summer pressure patterns, we carried out an intensive meteorological observation to examine the warming effects due to artificial constructions in a large housing complex. We set an automatic weather system(AWS) at two places in a bare soil surface within a limited development district and an asphalt surface within a large apartment residence area, respectively. As a result of observation, it became clear that the difference of the surface air(ground) temperature between the bare soil surface and its peripheral asphalt area reached about 4$^{\circ}C$(13$^{\circ}C$) at the maximum from diurnal variation of surface temperatures on AWS data. Through the heat balance analysis using measurement data, it became clear that the thermal conditions at two places are dependent on the properties of surface material. The latent heat flux over the bare soil surface reached to about 300 W/㎡, which is more than a half of net radiation during the daytime. On the other hand, it was nearly zero over the asphalt surface. Hence, the sensible heat flux over the asphalt surface was far more than that of the bare soil surface. The sensible heat flux over the asphalt surface showed about 20∼30 W/㎡ during the night. It was released from asphalt surface which have far more heat capacity than that of bare soil surface.

Seasonal Phosphorus Dynamics in a Forest Stream Water Following Different Harvests

  • Park, Byung Bae
    • Journal of Korean Society of Forest Science
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    • v.97 no.2
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    • pp.181-186
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    • 2008
  • Even small changes in phosphorus concentrations in stream water could cause eutrophication because of very low level of phosphorus concentrations in natural waters. I investigated the impact of strip cut and clear cut on phosphorus concentrations in stream water at the Hubbard Brook Experimental Forest and investigated stream water phosphorus concentrations as a function of flow rate and season (as well as cutting history). Mean phosphate concentrations in the control (undisturbed forest) increased $1.9{\mu}g\;L^{-1}\;to\;2.6{\mu}g\;L^{-1}$, while strip cut treatment increased phosphate concentrations in stream water $2.2{\mu}g\;L^{-1}\;to\;3.7{\mu}g\;L^{-1}$ during the same period. There was no significant effect of clear cut treatment on phosphate concentrations in stream water. No relationships were found between discharge rate and phosphate concentrations, but the magnitude of fluctuation were increased during two decades in undisturbed forest: $1-5{\mu}g\;L^{-1}$ from 1963 to 1975 and $1-12{\mu}g\;L^{-1}$ from 1983 to 1995. Based on this study, forest harvests with buffer zone will not make a problem by imported phosphate to cause eutrophication in natural water.

A Study on the TQM and 6 Sigma Management - Primarily on service industry - (TQM과 6시그마 경영에 관한 고찰 - 서비스산업을 중심으로)

  • 김동훈;장영준
    • Journal of Korean Society for Quality Management
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    • v.30 no.3
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    • pp.120-138
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    • 2002
  • In order to carry out TQM and 6 Sigma management, it is the key elements to make clear a goal and a mission. Above all, we can succeed In achieving a dramatic change and a great outcome only when we make clear the method, incentives, organization and plans under the clear objective. In order to secure the competitiveness against the external challenge, it is essential to keep the several crucial factors such as CEO's will, the systematic process to measure and manage, monitoring to satisfy customer's needs and an aggressive development of TQM activity to encourage the endeavour of the relentless enhancement, and also a positive effort Is to be made for evaluating all quality culture like training experts internally by an outstanding training program under CEO's firm leadership. This study is carried out to understand that which features and factors of success can exist in a company culture if a company accepts a theoretical basis and concept, the general of TQM and 6 Sigma which are one of a management strategy, and carries out TQM and 6 Sigma for achieving improvement of quality and customer's satisfaction.

Daily Operating Characteristics of Desalination System with Solar Energy (태양에너지 해수담수화 시스템 일일 운전 특성)

  • Kwak, Hee-Youl;Joo, Hong-Jin
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.06a
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    • pp.262-265
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    • 2009
  • This study was carried out to evaluate the clear day operating performances for the decentralized desalination system with the solar thermal system and the photovoltaic power system. In a clear day, we used a solar thermal system as heat source of the single-stage fresh water generator with plate-type heat exchangers and a photovoltaic power system as electric source for hydraulic pumps. The demonstration system generation was designed and installed at Jeju-island in 2006. The system was comprised of the desalination unit with daily fresh water capacity designed as $2m^3$, a $120m^3$ evacuated tubular solar collector to supply the heat, a $6m^3$ heat storage tank, and a 5.2kW photovoltaic power generation to supply the electricity of hydraulic pumps for the heat medium fluids. In a clear day, solar irradiance daily averaged was measured $518W/m^3$, the daily fresh water yield showed that about 565 liter.

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Benign Clear Cell ("Sugar") Tumor of the Lung -A Case Report- (폐양성 투명세포(당)종양 -1례 보고-)

  • 이종국;서재정
    • Journal of Chest Surgery
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    • v.29 no.4
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    • pp.461-465
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    • 1996
  • We experienced a case of benign clear cell tumor of the lung. It is a rare and very unusual pulmonary neoplasm. Only 40 cases have been reported in the foreign literatures, but this is the 2nd case report in Korea. A 43 year old man who revealed a coin lesion in the chest X-ray at the health screening, underwent resection of the right lower lobe Pathologically the tumor ce ls have a clear cytoplasm due to abundant glycogen in the histochemical and electron microscopical studies.

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An Effective Algorithm for Transmitted Solar Radiation Calculation through Window Glazing on a Clear Day

  • Oh, John Kie-Whan
    • KIEAE Journal
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    • v.14 no.4
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    • pp.35-45
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    • 2014
  • The main objective of this study is to provide an effective algorithm of the transmitted solar radiation calculation through window glazing on a clear day. This algorithm would be used in developing a computer program for fenestration system analysis and shading device design. Various simulation methods have been evaluated to figure out the most accurate and effective procedure in estimation of transmitted solar radiation on a tilted surface on a clear day. Characteristics of simulated results of each step have been scrutinized by comparing them with measured results of the site as well as results from other simulation programs. Generally, the Duffie & Beckman's solar calculation method introducing the HDKR anisotropic model provided the most reliable simulation results. The DOE-2 program usually provided over-estimated simulation results. The estimation of extraterrestrial solar radiation and beam normal radiation were conducted pretty accurately. However, the solar radiation either on horizontal surface or on tilted surface involves complicated factors in estimation. Even though the estimation results were close to the real measured data during summer when solar intensity is getting higher, the estimation provided more error when solar intensities were getting weaker. The convex polygon clipping algorithm with homogeneous coordinates was fastest model in calculation of sunlight to shaded area ratio. It could not be applied because of its shape limitation.

Prediction Models to Control Pro-chlorination in Water Treatment Plant (정수장 후염소 공정제어를 위한 예측모델 개발)

  • Shin, Gang-Wook;Lee, Kyung-Hyuk
    • Journal of Korean Society of Water and Wastewater
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    • v.22 no.2
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    • pp.213-218
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    • 2008
  • Prediction models for post-chlorination require complicated information of reaction time, chlorine dosage considering flow rate as well as environmental conditions such as turbidity, temperature and pH. In order to operate post-chlorination process effectively, the correlations between inlet and outlet of clear well were investigated to develop prediction models of chlorine dosages in post-chlorination process. Correlations of environmental conditions including turbidity and chlorine dosage were investigated to predict residual chlorine at the outlet of clear well. A linear regression model and autoregressive model were developed to apply for the post-chlorination which take place time delay due to detention in clear well tank. The results from autoregressive model show the correlationship of 0.915~0.995. Consequently, the autoregressive model developed in this study would be applicable for real time control for post chlorination process. As a result, the autoregressive model for post chlorination which take place time delay and have multi parameters to control system would contribute to water treatment automation system by applying the process control algorithm.

Standardized Uptake Values Highly Correlate with Tumor Size and Fuhrman Grade in Patients with Clear Cell Renal Cell Carcinoma

  • Polat, Emre Can;Otunctemur, Alper;Ozbek, Emin;Besiroglu, Huseyin;Dursun, Murat;Ozer, Kutan;Horsanali, Mustafa Ozan
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.18
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    • pp.7821-7824
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    • 2014
  • Background: We investigated the correlation between standardized uptake value (SUVmax), tumor size and Fuhrman grade in patients with renal cell carcinoma (RC). Materials and Methods: We retrospectively analyzed the data of 54 patients with clear cell renal cell carcinoma histopathologically diagnosed who underwent fluorine-18 fluoro-2 deoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) between January 2005 and March 2014. Results: Avarage tumor sizes were $5.64{\pm}1.85$, $6.85{\pm}2.24$ and $7.98{\pm}2.45$ in low, medium and high SUVmax groups, respectively. The Spearman's correlation coefficient between the tumor size and SUVmax was 0.385 (p=0.004) and between the Fuhrman grade and SUVmax was 0.578 (p<0.001). Conclusions: SUVmax appears highly correlated with tumor size and Fuhrman grade in patients with histopathologically confirmed clear cell RC. Multicenter studies are needed to provide larger series for more accurate results.