• The Korean Journal of Nuclear Medicine
• /
• v.20 no.1
• /
• pp.25-31
• /
• 1986

This study was performed to establish normal hepatoscintiangiographic(HSA) pattern of hepatic blood flow and to investigate dynamic differential HSA findings of primary and metastatic carcinomas and abscess of the liver. HSA was carried out after intravenous bolus injection of 10 mCi of Tc-99m-phytate by obtaining sequential anterior images of 1-second exposure for 16 seconds. Observations included (1) baseline study of normal hepatic blood flow pattern by correlating with contrast angiogram, (2) time sequence phasing of normal HSA, and (3) analysis of altered patterns in primary and metastatic carcinomas and abscesses of the liver. Materials consisted of 20 normal subjects, 28 primary hepatocellular carcinomas, 16 metastatic carcinomas and 7 liver abscesses. Results were: (1) Normal HSA demonstrated 3 distinct phases of arterialization(AP), of arterial hepatogram(AHP), and of portal venous hepatogram(PVHP). The means of each phase were 5.3, 6.3 and 8.3 seconds, respectively. Portal vein could be seen in all but one of 20 normal subjects. (2) Pattern changes in diseases groups were early start of AP in carcinomas and very early start of AP in abscesses. AP became prolonged in all disease group. (3) Distinction between AHP was sharp in metastasis and abscesses but un sharp in primary hepatoma. Cold area or areas became vascularized in primary hepatoma but not in abscess. Cold areas of metastasis were inhomogeneously vascularized in late AP and throughout AHP and became relatively vascular as PVHP began. The cold area of abscess showed rim enhancement during AH and APH. These differences in HSA pattern were very useful in differential diagnosis of the diseases studied.

• Nuclear Engineering and Technology
• /
• v.41 no.10
• /
• pp.1263-1274
• /
• 2009

Several experimental tests to simulate a reflood phase of a cold-leg LBLOCA of the APR1400 have been performed using the ATLAS facility. This paper describes the related experimental results with respect to the thermal-hydraulic behavior in the core and the system-core interactions during the reflood phase of the cold-leg LBLOCA conditions. The present descriptions will be focused on the LB-CL-09, LB-CL-11, LB-CL-14, and LB-CL-15 tests performed using the ATLAS. The LB-CL-09 is an integral effect test with conservative boundary condition; the LB-CL-11 and -14 are integral effect tests with realistic boundary conditions, and the LB-CL-15 is a separated effect test. The objectives of these tests are to investigate the thermal-hydraulic behavior during an entire reflood phase and to provide reliable experimental data for validating the LBLOCA analysis methodology for the APR1400. The initial and boundary conditions were obtained by applying scaling ratios to the MARS simulation results for the LBLOCA scenario of the APR1400. The ECC water flow rate from the safety injection tanks and the decay heat were simulated from the start of the reflood phase. The simulated core power was controlled to be 1.2 times that of the ANS-73 decay heat curve for LB-CL-09 and 1.02 times that of the ANS-79 decay curve for LB-CL-11, -14, and -15. The simulated ECC water flow rate from the high pressure safety injection pump was 0.32 kg/s. The present experimental data showed that the cladding temperature behavior is closely related to the collapsed water level in the core and the downcomer.

• Nuclear Engineering and Technology
• /
• v.8 no.4
• /
• pp.203-207
• /
• 1976

Strain rate dependence of the flow stress of cold-worked and annealed Zircaloy-4 was studied by stress relaxation test in temperature range of 20$0^{\circ}C$ to 45$0^{\circ}C$. The In $\sigma$-ln i curves for various temperatures were straight in the eirange of 10$^{-5}$ to 10$^{-3}$ sec$^{-1}$ . From the slope of a curve strain rate sensitivity m was obtained. The m in cold-worked Zircaloy-4 had a minimum value at 30$0^{\circ}C$, while m in annealed Zircaloy-4 had two minimum values, one at 30$0^{\circ}C$ and the other at 45$0^{\circ}C$. It was found that the temperatures of the minimum m are consistent with the temperatures of strain ageing peaks. The minimum m at 30$0^{\circ}C$ is considered to be due to strain ageing owing to the pinning of glide dislocations by oxygen atoms, while the minimum m at 45$0^{\circ}C$ for annealed specimen is attributed to iron atoms.

• The KSFM Journal of Fluid Machinery
• /
• v.12 no.5
• /
• pp.7-12
• /
• 2009

A nuclear fuel test loop(after below, FTL) is installed in the IRI of an irradiation hole in HANARO for testing the neutron irradiation characteristics and thermo hydraulic characteristics of a fuel loaded in a light water power reactor or a heavy water power reactor. There is an in-pile section(IPS) and an out-pile section(OPS) in this test loop. When HANARO is operated normally, the fuel loaded into the IPS has a nuclear reaction heat generated by a neutron irradiation. To remove the generated heat and to maintain the operation conditions of the test fuel, a main cooling water system(MCWS) is installed in the OPS of the FTL. The MCWS is composed of a main cooler, a pressurizer, two circulation pumps, a main heater, an interconnection pipe line and instruments. The interconnection pipeline is a closed loop which is connected to an inlet and an outlet of the IPS respectively. The MCWS is under a cold function test during a start-up period. This paper describes the system flow network analysis results of the flow control of a main cooling water system in the HANARO fuel test loop. It was confirmed through the results that the flow was met the system design requirements.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.19 no.11
• /
• pp.3003-3013
• /
• 1995

The characteristics of the flow field in the tangentially fired furnace are presented. Experiments are conducted in the simplified cold type isothermal flow model. In the measurement of flow field, a hot wire anemometer is used. The hot wire was calibrated by lookup table method. The mean velocity field and turbulence characteristics are showed with changing the nozzle angle. In the center of the model, the low speed, unstable flow region is formed. The size and position of these regions are varied with changing the nozzle angle. It can be used as fundamental data in the design of the large furnace. From the experimental results, various turbulent characteristics of swirling flow field is obtained. And the entrainment mechanism of the jet flow field is described from the distribution of the skewness and the flatness. It can be used the raw data of approximate calculation and turbulent modelling.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.13 no.2
• /
• pp.35-41
• /
• 2009

Both the nozzle expansion ratio and the chamber pressure are simultaneously and continuously changed according to pintle movement, resulting in a different internal flow structure and flow separation characteristics. In this paper, the pintle position effect on nozzle flow structure and separation phenomena is analyzed by experimental-aided Computational Fluid Dynamic(CFD). Among the turbulent models for RANS(Reynold Averaged Navier Stokes) in Fluent, Spalart-Allmaras model is better agreement with the nozzle wall pressure distribution attained by cold-flow test than other models. And even if a conical nozzle is used, there is a shock structure similar to cap-shock pattern mainly occurred in contoured or shaped optimized nozzle because of internal shock generated from pintle tip flow separation.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.8 no.1
• /
• pp.171-181
• /
• 2013

The relationship about corporations' dividend policy and foreigners' share have been studied on the various views. However, there have barely been the studies about the relationships between the two variables according to hot and cold markets in Korea. In this point, this study attempts to find the differences of the tendency of foreigners' investment with financial variables and the relationship between foreigners' share and corporations' dividend policy according to hot and cold markets. For the analysis, it selected the 318 manufacturing corporations, which paid dividends in 2008 (cold market) and 2010(hot market). The results are classified into two types. 1) There are the difference, and 2) There are no differences of the relationships among the variables according to the two markets. First of all, The relationships between 1) foreigners' share and dividend 2) between foreigners' share and market value (Tobin's Q) and corporations' debt (Debt Ratio) were statistically significant in the both (hot and cold) markets. As showing the differences according to hot and cold markets, cash flow and foreigners' share showed the statistically significant relationships in 2010 (hot market), not in 2008 (cold market). One of the remarkable results is that most of relationships among variables, except the relationship between foreigners' share and dividend, are more strong in hot market than in cold market.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.51 no.5
• /
• pp.70-83
• /
• 2023

Recently, the Korea Forest Service has implemented a planning project about wind corridor forests as a response measure to climate change. Based on this, research on wind corridors has been underway. For the creation of wind corridor forests, a preliminary evaluation of the wind corridor function is necessary. However, currently, there is no evaluation index to directly evaluate and spatially distinguish the types of wind corridors, and analysis is being performed based on indirect indicators. Therefore, this study proposed a method to evaluate and classify wind corridors by utilizing heat deficit analysis as an evaluation index for cold air generation. Heat deficit was analyzed using a cold air analysis model called Kaltluftabflussmodell_21 (KLAM_21). According to the results of the simulation analysis, the wind path was functionally classified. The top 5% were classified as cold-air generating Areas (CGA), and the bottom 5% as cold-air vulnerable Areas (CVA). In addition, the cold-air flowing Areas (CFA) were classified by identifying the flow of cold air moving from the cold air generation area. It is expected that the methodology of this study can be utilized as an evaluation method for the effectiveness of wind corridors. It is also anticipated to be used as an evaluation index to be presented in the selection of wind corridor forest sites.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.26 no.1
• /
• pp.21-40
• /
• 2023

This study analyzed the cold air characteristics of the Nakdong Jeongmaek, which is advantageous for the formation of cold air that can flow into the city, in order to suggest the wind ventilation corridor plans, which have recently been increasing interest as a way to improve the urban thermal environment. In addition, based on the watershed analysis, specific cold-air watershed areas were established and management plans were suggested to expand the cold air function of the Nakdong Jeongmaek. As a result of the analysis of cold air in the Nakdong Jeongaek, cold air was strongly generated in the northern forest of the Jeongamek, and flowed into nearby cities along the valley topography. On average, the speed of cold air was high in cities located to the east of the Jeongmaek, while the height of cold air layer was high in cities located to the west. By synthesizing these cold air characteristics and watershed analysis results, the cold-air watershed area was classified into 8 zones, And the plans were proposed to preserve and strengthen the temperature reduction of the Jeongmaek by designating the zones as 'Conservation area of Cold-air', 'Management area of Cold-air', and 'Intensive management area of Cold-air'. In addition, in order to verify the temperature reduction of cold air, the effect of night temperature reduction effect was compared with the cold air analysis using weather observation data. As a result, the temperature reduction of cold air was confirmed because the night temperature reduction was large at the observation station with strong cold air characteristics. This study is expected to be used as basic data in establishing a systematic preservation and management plan to expand the cold air function of the Nakdong Jeongmaek.

• Korean Journal of Oriental Medicine
• /
• v.3 no.1
• /
• pp.169-181
• /
• 1997

Kimi(氣味) means five tastes(五味), sour, bitterness, sweetness, hot taste and astringency, and four conditions(四氣), cold, hot, warm and cool, in the oriental medicine. This is defined based on yn-yang 5 evolutive phasis(陰陽五行), and 5 evolutive phasis on the change of season. Four seasons, spring, summer, autumm, winter are clearly different but, the rainy season(長夏) is not. In the thee of Ki (氣), not worm not hot(平) is included in addition to the four conditions that is because the rainy season is not differentiated clearly. KImi have realations to the four seasons, that is, warm and hot taste is considered as spring, hot and astringency as summer, not worm not hot and sweetness as rainy season, cool and sour as autumm, and cold and bitterness as winter. 4 conditions can be classified more detail, because the changes of the seasons are continuous. In the action mechanisms, Gardeniae Fructus reduces Heat of Insufficency Type(虛熱) of the upper class of medicinal herbs(上焦), and Rhel Rhizoma reduces Exessive Heat(實熱) of the under class of them(下焦). The assay methods for four groups medicines can be developed in three ways according to the indicators as follows. First, by the indicator which defines cold-acting medicine(寒性藥) such as Rhei Rhizoma, Coptidis Rhizoma, Scutellariae Radix, Gardeniae Fructus and is differentiated clearly from Hot-acting medicine(熱性藥) at the same time. Second, when the medicines are classified into another four groups as Drugs for Dispelling Internal Cold(溫裏藥), Drugs for Relieving Exterior Syndrome(解表藥), Drugs for Dispelling Phlegm(祛痰藥), Drugs for Regulatings Ki Flow(理氣藥), by the indicator which satisfies each group and is differentiated from other groups, at the same time. Third, by the indicator which has to be defined for each medicinal herb for four classification, individually.