• Title/Summary/Keyword: Flow-rate measurement

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The Development of High Pressure Long Distance Fire-fighting Hose with Phosphorescent Performance (축광 성능을 갖는 고압용 장거리 호스 개발에 관한 연구)

  • Han, Yong-Taek;Na, Byung-Gyun;Choi, Jin-Seong;Min, Se-Hong
    • Fire Science and Engineering
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    • v.31 no.5
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    • pp.63-69
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    • 2017
  • This study describes the development of a long-distance hose for ultra-high pressure operation, which can be used in conjunction with an ultra-high pressure pump and can be effectively applied to the fire suppression of high-rise buildings and a long, large tunnels. Also, it has phosphorescent properties, which can help to secure the withdrawal route of the fire-fighters when they are threatened by the fire. We developed an ultra-high pressure hose aiming at a pressure of 3 MPa and a flow rate of 2000 lpm and developed an ultra-high pressure fire hose that can withstand this very high pressure by using a double jacket, triple polyurethane coating and warf (Wp) of 52. In order to ensure the performance of the developed ultra-high pressure hose, its structure, appearance, leakage at high pressure, length and elongation were inspected by a certified certification agency, who also subjected it to a peeling test, friction test, breaking pressure test and free fall test. Also, it was studied in addition to the luminescent high-pressure hose for fire-fighting. In the phosphorescence test, the luminance measurement value was more than the reference value of the luminance test after 40 minutes, which confirmed that its performance was satisfactory for fire-fighting products. In the future, if such an ultra-high pressure fire hose were commercialized and applied in the field, it could contribute to securing improved fire suppression and safer exit from fires, as compared to the fire hoses currently used in the suppression of fires in skyscraper buildings and long tunnels.

Evaluation of Image Quality for Compressed SENSE(CS) Method in Cerebrovascular MRI: Comparison with SENSE Method (뇌혈관자기공영영상에서 Compressed SENSE(CS) 기법에 대한 영상의 질 평가: SENSE 기법과 비교)

  • Goo, Eun-Hoe
    • Journal of the Korean Society of Radiology
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    • v.15 no.7
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    • pp.999-1005
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    • 2021
  • The object of this research is CS, which increases resolution while shortening inspection time, is applied to MRA to compare the quality of images for SENSE and CS techniques and to evaluate SNR and CNR to find out the optimal techniques and to provide them as clinical basic data based on this information. Data were analyzed on 32 patients who performed TOF MRA tests at a university hospital in Chung cheong-do (15 males, 17 females), ICA stenosis:10, M1 Aneurysm:10, and average age 53 ± 4.15). In the inspection, the inspection equipment was Ingenia CX 3.0T, Archieva 3.0T, and 32 channel head coil and 3D gradient echo as a method for equipment data. SNR and CNR of each image were measured by quantitative analysis, and the quality of the image was evaluated by dividing the observer's observation into 5 grades for qualitative evaluation. Imaging evaluation is described as being significant when the p-value is 0.05 or less when the paired T-test and Wilcoxon test are performed. Quantitative analysis of SNR and CNR in TOF MRA images Compared to the SENSE method, the CS method is a method measurement method (p <0.05). As an observer's evaluation, the sharpness of blood vessels: CS (4.45 ± 0.41), overall image quality: CS (4.77 ± 0.18), background suppression of images: CS (4.57 ± 0.18) all resulted in high CS technique (p = 0.000). In conclusion, the Compressed SENSE TOF MRA technique shows superior results when comparing and evaluating the SENSE and Compressed SENSE techniques in increased flow rate magnetic resonance angiography. The results are thought to be the clinical basis material in the 3D TOF MRA examination for brain disease.

Analysis of Heat Emission from Hot Water Pipe for Greenhouse Heating System Design (온실 난방시스템 설계를 위한 온수난방배관의 방열량 분석)

  • Shin, Hyun-Ho;Nam, Sang-Woon
    • Journal of Bio-Environment Control
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    • v.28 no.3
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    • pp.204-211
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    • 2019
  • The purpose of this study is to provide basic data for setting environmental design standards for domestic greenhouses. We conducted experiments on thermal environment measurement at two commercial greenhouses where hot water heating system is adopted. We analyzed heat transfer characteristics of hot water heating pipes and heat emission per unit length of heating pipes was presented. The average air temperature in two greenhouses was controlled to $16.3^{\circ}C$ and $14.6^{\circ}C$ during the experiment, respectively. The average water temperature in heating pipes was $52.3^{\circ}C$ and $45.0^{\circ}C$, respectively. Experimental results showed that natural convection heat transfer coefficient of heating pipe surface was in the range of $5.71{\sim}7.49W/m^2^{\circ}C$. When the flow rate in heating pipe was 0.5m/s or more, temperature difference between hot water and pipe surface was not large. Based on this, overall heat transfer coefficient of heating pipe was derived as form of laminar natural convection heat transfer coefficient in the horizontal cylinder. By modifying the equation of overall heat transfer coefficient, a formula for calculating the heat emission per unit length of hot water heating pipe was developed, which uses pipe size and temperature difference between hot water and indoor air as input variables. The results of this study were compared with domestic and foreign data, and it was found to be closest to JGHA data. The data of NAAS, BALLS and ASHRAE were judged to be too large. Therefore, in order to set up environmental design standards for domestic greenhouses, it is necessary to fully examine those data through further experiments.

Surface soil moisture memory using stored precipitation fraction in the Korean peninsula (토양 내 저장 강수율을 활용한 국내 표층 토양수분 메모리 특성에 관한 연구)

  • Kim, Kiyoung;Lee, Seulchan;Lee, Yongjun;Yeon, Minho;Lee, Giha;Choi, Minha
    • Journal of Korea Water Resources Association
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    • v.55 no.2
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    • pp.111-120
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    • 2022
  • The concept of soil moisture memory was used as a method for quantifying the function of soil to control water flow, which evaluates the average residence time of precipitation. In order to characterize the soil moisture memory, a new measurement index called stored precipitation fraction (Fp(f)) was used by tracking the increments in soil moisture by the precipitation event. In this study, the temporal and spatial distribution of soil moisture memory was evaluated along with the slope and soil characteristics of the surface (0~5 cm) soil by using satellite- and model-based precipitation and soil moisture in the Korean peninsula, from 2019 to 2020. The spatial deviation of the soil moisture memory was large as the stored precipitation fraction in the soil decreased preferentially along the mountain range at the beginning (after 3 hours), and the deviation decreased overall after 24 hours. The stored precipitation fraction in the soil clearly decreased as the slope increased, and the effect of drainage of water in the soil according to the composition ratio of the soil particle size was also shown. In addition, average soil moisture contributed to the increase and decrease of hydraulic conductivity, and the rate of rainfall transfer to the depths affected the stored precipitation fraction. It is expected that the results of this study will greatly contribute in clarifying the relationship between soil moisture memory and surface characteristics (slope, soil characteristics) and understanding spatio-temporal variation of soil moisture.

A study on Digital Agriculture Data Curation Service Plan for Digital Agriculture

  • Lee, Hyunjo;Cho, Han-Jin;Chae, Cheol-Joo
    • Journal of the Korea Society of Computer and Information
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    • v.27 no.2
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    • pp.171-177
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    • 2022
  • In this paper, we propose a service method that can provide insight into multi-source agricultural data, way to cluster environmental factor which supports data analysis according to time flow, and curate crop environmental factors. The proposed curation service consists of four steps: collection, preprocessing, storage, and analysis. First, in the collection step, the service system collects and organizes multi-source agricultural data by using an OpenAPI-based web crawler. Second, in the preprocessing step, the system performs data smoothing to reduce the data measurement errors. Here, we adopt the smoothing method for each type of facility in consideration of the error rate according to facility characteristics such as greenhouses and open fields. Third, in the storage step, an agricultural data integration schema and Hadoop HDFS-based storage structure are proposed for large-scale agricultural data. Finally, in the analysis step, the service system performs DTW-based time series classification in consideration of the characteristics of agricultural digital data. Through the DTW-based classification, the accuracy of prediction results is improved by reflecting the characteristics of time series data without any loss. As a future work, we plan to implement the proposed service method and apply it to the smart farm greenhouse for testing and verification.

Effect of long-term high-fat diet and fasting on energy metabolic substrates utilization in resting rats

  • Jeon, Yerim;Kim, Jisu;Hwang, Hyejung;Suh, Heajung;Lim, Kiwon
    • Korean Journal of Exercise Nutrition
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    • v.15 no.4
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    • pp.163-171
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    • 2011
  • The effects of a high-fat diet and fasting on resting energy expenditure and energy substrate utilization were examined using the method of measuring whole body energy metabolism and oxygen uptake. Eight 4-week old male Sprague-Dawley rats were used for the high-fat diet experiment. Energy metabolism was measured using acrylic metabolic chambers over 24 hours. After 1-week of preliminary feeding, 4 rats were fed a chow diet, whereas the remaining 4 rats were fed a high-fat diet (HF) ad libitum, which contained 40% (w/w, calorie base 60%) more fat than that in the chow diet. The flow rate to measure energy metabolism inside the chamber was controlled at a mean of 3.5 L/min, and five chambers were subjected to measurement. One of the five chambers was used to correct errors by measuring the atmosphere. As a result of 5 weeks of control diet and high-fat diet feeding, body weight of the high-fat diet group tended to increase more than that in the control diet fed group, but the difference was not significant. Oxygen uptake and carbon dioxide production changed as time went on over the 24 hr. The respiratory exchange ratio also changed during the 24 hr, and the difference between the groups was significant. The control group showed significantly more carbohydrate oxidation than that of the high-fat diet fed group. A fasting experiment was conducted using six 7-week old Sprague-Dawley male rats. Energy metabolism measurements were performed using the same method as that used in the high-fat diet experiment; resting metabolism was measured prior to fasting, and a fasting condition began from 9:00 am the next day for 3 days to calculate energy metabolism. Both body weight and 24-hour oxygen uptake decreased significantly as a result of 3-day fasting. Total oxygen uptake in the first day decreased, and declined significantly on day 3 of fasting. Total 24-hour carbon dioxide production decreased significantly over the 3 days. The mean 24-hour respiratory exchange ratio decreased significantly. Additionally, energy expenditure during the dark period (20:00-08:00), which is the active period for rats, decreased significantly with fasting, whereas energy expenditure during the light period (08:00-20:00) did not increase by fasting.

THE ANTICANCER EFFECT OF PACLITAXEL($Taxol^{(R)}$) IN ORAL SQUAMOUS CELL CARCINOMA XENOGRAFT (이종 이식된 구강편평세포 암종에서 Paclitaxel ($Taxol^{(R)}$)의 항암 효과)

  • Kim, Ki-Hwan;Kim, Chul-Hwan;Han, Se-Jin;Lee, Jae-Hoon
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.28 no.2
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    • pp.95-110
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    • 2006
  • The treatment for oral and maxillofacial carcinoma with chemotherapeutic agents is evaluated by many effective methods to reduce the tumor mass and cancer cell proliferation. However these chemotherapy have many serious side effects, such as bone marrow suppression, renal toxicity, G-I troubles. Therefore a possible approach to develop a clinically applicable chemotherapeutic agent is to screen anticancer activity of Taxol which is known to have very little side effect and have been used to breast cancer and ovarian carcinoma. Taxol is a new anti-microtubular anti-cancer agent extracted from the bark of the Pacific yew, Taxus brevifolia. Paclitaxel(Taxol) acts by promoting tubulin polymerization and over stabilizing microtubules agianst depolymerization. Despite the constant improvements of methods of the cancer treatment especially chemotherapy, the rate of cancer metastasis and recurrent are not decreased. Thus the investigation of new drug which have very little side effect and a possible clinically application continues to be a high priority. Considering that the Taxol have shown very effective chemotherapeutic agent with relatively low toxicity in many solid tumors, it deserves to evaluate its efficacy in oral squamous cell carcinoma. In this study, to investigate the in-vivo and in-vitro anti-cancer efficacy of Taxol in oral squamous cell carcinoma and lastly, the potency of Paclitaxel in the clinical application for oral cancer was evaluated. In vivo study, after HN22 cell line were xenografted in nude mice, the growth of tumor mass was observed, 3 mg/Kg taxol was injected intraperitoneally into nude mice containing tumor mass. The methods of these study were measurement of total volume of tumor mass, histopathologic study, immunohistochemical study, drug resistance assay, growth curve, MTT assay, flow cytometry, cDNA microarray in vivo and in vitro. The results were obtained as following. 1. The visual inspection of the experimental group showed that the volume of the tumor mass was slightly decreased but no significant difference with control group. 2. Ki-67 index was decreased at weeks 4 in experimental group. 3. Microscopic view of the xenografted tumor mass showed well differentiated squamous cell carcinoma and after Taxol injection, some necrotic tissue was seen weeks 4. 4. The growth curve of the tumor cells were decreased after 1day Taxol treatment. 5. According to the MTT assay, HN22 cell line showed relative drug resistancy above $5\;{\mu}g/ml$ concentrations of Taxol. 6. In drug resistance assay, the decrease of cell counts was seen relatively according to concentration. 7. In Flow cytometry, G2M phase cell arrests were seen in low concentration of the Taxol, while S phase cell arrests were seen in high concentration of the Taxol. 8. Using cDNA microarray technique, variable gene expression of ANGPTL4, TXNRD1, FAS, RRAGA, CTGF, CYCLINEA, P19, DUSP5, CEBPG, BTG1 were detacted in the oral squamous cell carcinoma cell after taxol treatment. In this study paclitaxel is effective against oral squamous cell carcinoma cell lines in vitro, but week effect was observed in vivo. So we need continuous study about anticancer effect of taxol in vivo in oral squamous cell carcinoma.

Landscape Changes of the Mujechi Moor, Mt. Jungjok (정족산 무제치늪의 경관발달)

  • 유호상;공우석
    • The Korean Journal of Quaternary Research
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    • v.15 no.2
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    • pp.101-109
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    • 2001
  • The landscape changes at the Mujechi moors I and II during the last twenty two years were analysed using a tree ring analysis of pine trees, a distributional pattern of pine tree, an aerial photograph interpretation and a measurement of firebreak line. The analysis of aerial photographs(taken in 1978, 1988, 1998) indicates that the area of Mujechi moors I and II have gradually decreased. The decreased rate of moor area was relatively high, i.e.,-23.9 %(1978~1988) and -16.4 %(1998~1998) at the Mujechi moor I, but a little bit low, i.e., -2.6% (1978~1988) and -12.6 % (1998~1998) at the Mujechi moor II. However, dendrochronological analysis of pine trees at moors I and II shows that the appearance rates of pine trees per $100\textrm{m}^2$ at moor I and II were 0.28 and 0.57 respectively. And the number of younger pine trees(height is under 1.5m, DBH is less than 2.5 cm) invaded into moors are numbered eleven at the moor I, and ten at the moor II. This shows that the shift of a wetlands into a land was faster at the moor II than the moor I. The construction of a firebreak line and waterway along the moors I and II areas since the December, 1995, has diverted watershed flow and prohibited the runoff flow into the moors. The analysis of GIS suggests that the decreased watershed area were about $11,413.8\textrm{m}^2$(12.1 % of whole watershed area) at the moor I and $15,969.5\textrm{m}^2$(40.4 % of whole watershed area) at the moor II. The negative impact of firebreak line on the inflow of water into the moors I and II and destruction of vegetation along the firebreak line are noticeable from the field survey.

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CO2 Exchange in Kwangneung Broadleaf Deciduous Forest in a Hilly Terrain in the Summer of 2002 (2002년 여름철 경사진 광릉 낙엽 활엽수림에서의 이산화탄소 교환)

  • Choi, Tae-jin;Kim, Joon;Lim, Jong-Hwan
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.5 no.2
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    • pp.70-80
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    • 2003
  • We report the first direct measurement of $CO_2$ flux over Kwangneung broadleaf deciduous forest, one of the tower flux sites in KoFlux network. Eddy covariance system was installed on a 30 m tower along with other meteorological instruments from June to August in 2002. Although the study site was non-ideal (with valley-like terrain), turbulence characteristics from limited wind directions (i.e., 90$\pm$45$^{\circ}$) was not significantly different from those obtained at simple, homogeneous terrains with an ideal fetch. Despite very low rate of data retrieval, preliminary results from our analysis are encouraging and worthy of further investigation. Ignoring the role of advection terms, the averaged net ecosystem exchange (NEE) of $CO_2$ ranged from -1.2 to 0.7 mg m$^{-2}$ s$^{-1}$ from June to August in 2002. The effect of weak turbulence on nocturnal NEE was examined in terms of friction velocity (u*) along with the estimation of storage term. The effect of low uf u* NEE was obvious with a threshold value of about 0.2 m s$^{-1}$ . The contribution of storage term to nocturnal NEE was insignificant; suggesting that the $CO_2$ stored within the forest canopy at night was probably removed by the drainage flow along the hilly terrain. This could be also an artifact of uncertainty in calculations of storage term based on a single-level concentration. The hyperbolic light response curves explained >80% of variation in the observed NEE, indicating that $CO_2$ exchange at the site was notably light-dependent. Such a relationship can be used effectively in filling up the missing gaps in NEE data through the season. Finally, a simple scaling analysis based on a linear flow model suggested that advection might play a significant role in NEE evaluation at this site.

The Development of a Benthic Chamber (BelcI) for Benthic Boundary Layer Studies (저층 경계면 연구용 Benthic chamber(BelcI) 개발)

  • Lee, Jae-Seong;Bahk, Kyung-Soo;Khang, Buem-Joo;Kim, Young-Tae;Bae, Jae-Hyun;Kim, Seong-Soo;Park, Jung-Jun;Choi, Ok-In
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.15 no.1
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    • pp.41-50
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    • 2010
  • We have developed an in-situ benthic chamber (BelcI) for use in coastal studies that can be deployed from a small boat. It is expected that BelcI will be useful in studying the benthic boundary layer because of its flexibility. BelcI is divided into three main areas: 1) frame and body chamber, 2) water sampler, and 3) stirring devices, electric controller, and data acquisition technology. To maximize in-situ use, the frame is constructed from two layers that consist of square cells. All electronic parts (motor controller, pA meter, data acquisition, etc.) are low-power consumers so that the external power supply can be safely removed from the system. The hydrodynamics of BelcI, measured by PIV (particle image velocimetry), show a typical "radial-flow impeller" pattern. Mixing time of water in the chamber is about 30 s, and shear velocity ($u^*$) near the bottom layer was calculated at $0.32\;cm\;s^{-1}$. Measurements of diffusivity boundary layer thickness showed a range of $180-230\;{\mu}m$. Sediment oxygen consumption rate, measured in-situ,was $84\;mmol\;O_2\;m^{-2}\;d_{-1}$, more than two times higher than on-board incubation results. Benthic fluxes assessed from in-situ incubation were estimated as follows: nitrate + nitrite = $0.18\;{\pm}\;0.07\;mmol\;m^{-2}\;d^{-1}$ ammonium $23\;{\pm}\;1\;mmol\;m^{-2}\;d^{-1}$ phosphate = $0.09\;{\pm}\;0.02\;mmol\;m^{-2}\;d^{-1}$ and silicate = $23\;{\pm}\;1\;mmol\;m^{-2}\;d^{-1}$.