• Title/Summary/Keyword: Nuclear Science and Engineering

Search Result 2,472, Processing Time 0.032 seconds

Structural and Chemical Characterization of Aquatic Humic Substances in Advanced Water Treatment Processes (고도정수처리 공정에서 수질계 휴믹물질의 구조 및 화학적 특성분석)

  • Kim, Hyun-Chul;Yu, Myong-Jin
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.27 no.3
    • /
    • pp.240-246
    • /
    • 2005
  • Humic substances HS) from process waters at advanced water treatment plant consisted of GAC and Ozone/GAC processes were isolated and extracted by physicochemical fractionation methods to investigate their characteristics. They are characterized for their functionality, chemical composition, spectroscopic characteristics using FT-IR and $^1H$-NMR spectroscopy. Humic fraction gradually decreased from 36.3% to 24.2% from 0.45 to 0.30 mgC/L) through ozonation and carbon adsorption. The humic fraction was isolated into the phenolic and carboxylic groups using A-21 resin, and the concentration of phenolic groups gradually decreased from 38.4% to 23.5% (from 4.9 to $3.2\;{\mu}M/L$ as phenolic-OH) through ozonation and carbon adsorption. In the case of carboxylic groups, the concentration decreased from 61.6% to 43.3% (from 7.8 to $5.8\;{\mu}M/L$ as COOH) through the water treatment processes. On the other hand, concentrations of those roups decreased from 38.4% to 24.0% and 61.6% to 44.9% through carbon adsorption without ozonation, respectively. The structural changes of HS identified from FT-IR and $^1H$-NMR were consistent with the results from the isolation of functional groups in HS.

Study on the elution of biostimulant for in-situ bioremediation of contaminated coastal sediment (오염된 연안저질의 현장생물정화를 위한 미생물활성촉진제의 용출특성 연구)

  • Woo, Jung-Hui;Song, Young-Chae;Senthilkumar, Palaninaicker
    • Journal of Navigation and Port Research
    • /
    • v.38 no.3
    • /
    • pp.239-246
    • /
    • 2014
  • A study on the elution characteristics of biostimulating agents (sulfate and nitrate) from biostimulants which are used for in-situ bioremediation for the coastal sediment contaminated with organic matter was performed. The biostimulating agents were mixed with the coastal sediment, and then massed the mixture into ball. Two kinds of ball type biostimulant were prepared by coating the ball surface with two different polymers, cellulose acetate and polysulfone. A granular type biostimulant (GTB) was also prepared by impregnating a granular activated carbon in the biostimulating agent solution. The image of scanning electron microscopy for the biostimulant coated with cellulose acetate (CAB) showed that the inner side of the coating layer consisted of irregular and bigger size of pores, and the surface layer had tight structure like beehive. For the biostimulant coated with polyfulfone (PSB), the whole coating layer had a fine structure without pore. The elution rate of the biostimulating agents for the CAB was higher than that for the PSB, and the elution rate for the GTB was considerably higher than that for the PSB in distilled water as well as in sea water. The elution rate of the biostimulating agents in turbulent water flow was about 3 times higher than that in standing water, and the elution rate of nitrate was higher than that of sulfate from the stimulating agents.

Danggwisu-san ameliorates acute inflammatory responses via NF-κB and MAPK pathway (당귀수산(當歸鬚散)의 in vitro 및 in vivo에서의 염증억제효과)

  • Chang Wook Lee;Sang Mi Park;Hyo Jeong Jin;Ye Lim Kim;Dae Hwa Jung;Sung Hui Byun;Sang Chan Kim
    • Herbal Formula Science
    • /
    • v.32 no.2
    • /
    • pp.155-179
    • /
    • 2024
  • Objective : Danggwisu-san (DGSS) is an herbal formula that has been mainly used in the East Asia for the treatment of bruise, sprain and external injury. The cause of this pain is that Qi and blood become tangled and do not circulate well. DGSS can improve the tangled situation and make it well-circulated. The present study evaluated the anti-inflammatory effects of DGSS on Raw 264.7 cells and in rats with paw edema. Methods : Cell viability was measured using the MTT assay. The amount of nitric oxide (NO) production was measured the amount of nitrite content in the cultured medium using Griess reagent. The amount of tumor necrosis factor-α, monocyte chemoattractant protein 1, interleukin (IL)-1βand IL-6 in the cultured supernatant were measured by ELISA kit. Proteins expression were detected by Western blot. Furthermore, the effect of DGSS on acute inflammation was observed in rat paw edema model. Results : The DGSS ameliorates the lipopolysaccharide-activated changes in NO production, iNOS expression and pro-inflammatory cytokines. Additionally, DGSS significantly suppressed expression of p-JNK, p-ERK and nuclear NF-κB. As expected, in rat paw edema study, 1.0 g/kg of DGSS significantly reduced the carrageenan-induced paw edema and iNOS expression for 1-4 h. Moreover, administration of 1.0 g/kg (4 days) of DGSS used in this study did not show any significant change on ALT and AST. Conclusion : These results demonstrate that DGSS has anti-inflammatory effects in vitro and in vivo. Therefore, this present study can put scientific evidences up for the anti-inflammatory effect of DGSS.

Flow analysis of the Sump Pump (흡수정의 유동해석)

  • Jung, Han-Byul;Noh, Seung-Hee
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.18 no.3
    • /
    • pp.673-680
    • /
    • 2017
  • sump pump is a system that draws in water that is stored in a dam or reservoir. They are used to pump large amounts of water for cooling systems in large power plants, such as thermal and nuclear plants. However, if the flow and sump pump ratio are small, the flow rate increases around the inlet port. This causes a turbulent vortex or swirl flows. The turbulent flow reduces the performance and can cause failure. Various methods have been devised to solve the problem, but a correct solution has not been found for low water level. The most efficient solution is to install an anti-vortex device (AVD) or increase the length of the sump inlet, which makes the flow uniform. This paper presents a computational fluid dynamics (CFD) analysis of the flow characteristics in a sump pump for different sump inlet lengths and AVD types. Modeling was performed in three stages based on the pump intake, sump, and pump. For accurate analysis, the grid was made denser in the intake part, and the grid for the sump pump and AVD were also dense. 1.2-1.5 million grid elements were generated using ANSYS ICEM-CFD 14.5 with a mixture of tetra and prism elements. The analysis was done using the SST turbulence model of ANSYS CFX14.5, a commercial CFD program. The conditions were as follows: H.W.L 6.0 m, L.W.L 3.5, Qmax 4.000 kg/s, Qavg 3.500 kg/s Qmin 2.500 kg/s. The results of analysis by the vertex angle and velocity distribution are as follows. A sump pump with an Ext E-type AVD was accepted at a high water level. However, further studies are needed for a low water level using the Ext E-type AVD as a base.

Thermoluminescence Dating of Pottery Shards by Subtraction Method (Subtraction 방법을 이용한 TL 연대측정법에 의한 토기 시편의 절대연대 결정)

  • Shin, Hyun-Sang;Lee, Chang-Woo;Nam, Young-Mee;Jee, Kwang-Yong;Park, Byung-Bin
    • Analytical Science and Technology
    • /
    • v.13 no.4
    • /
    • pp.403-411
    • /
    • 2000
  • This study described a method of thermoluminescence dating of pottery shards using subtraction method. TL measurement was achieved using two different types of samples prepared by quartz inclusion method and fine-grain technique. Fine grains (size range: $5-10{\mu}m$) were separated by suspending grounded pottery samples into acetone solution and sedimentation quantitatively. In quartz inclusion method quartz grains in the size range of 90 to $125{\mu}m$ diameter were obtained by extracting the quartz crystals embed in the pottery shards and etching them with 1.0 M HF solutions. The archaeological dose of both the quartz and fine grains was determined from the dose calibration curves obtained from sequential irradiation of $^{137}Cs$ gamma and $^{241}Am$ alpha source to the samples and TL measurement of natural samples, in which the alpha dose of 4.60 Gy for the Packjae pottery was obtained using subtraction method. Annual alpha dose rates ($3.05{\pm}0.11$ mGy/yr.) were determined by the analysis of U, Th contents in the pottery shards and evaluation of the values with Bell's equation. Dividing the alpha dose accumulated in the pottery shards by the annual alpha dose rate, we found age of approximately $1508{\pm}80$ years B.P. (AD. ca. 492 yr.) for the Packjae pottery. It matches well with the archeological age estimate (middle of 5th century) within 10 percent uncertainty and thereby conforms the age of the pottery sample.

  • PDF

The Electron Trap Analysis in Thermoluminescent LiF Crystal

  • Park, Dae-Yoon;Ko, Chung-Duck;Lee, Sang-Soo
    • Nuclear Engineering and Technology
    • /
    • v.4 no.3
    • /
    • pp.214-222
    • /
    • 1972
  • In the optic,11 grade LiF crystal, the electron traps corresponding to the thermoluminescence(abbreviated to TL) glow peak develop as irradiation dose is increased. Originally the electron trap of the crystal has two levels but as the dose reaches to the order of 10$^4$rontgen, it attains five levels as observed in the TL glow curves. The five trap depths are determined from the glow peak temperatures for two different heating rates, $\theta$=6.6$^{\circ}C$/sec and 3.4$^{\circ}C$/sec. The electron trap depths have the following values E$_1$=0.79 eV, E$_2$=0.93 eV, E$_3$=1.02 eV, E$_4$=1.35 eV, E$_{5}$=1.69eV. The special feature of thermoluminescence of optical grade LiF is that the traps, except E$_1$and E$_2$corresponding to 12$0^{\circ}C$ glow peak and 15$0^{\circ}C$ glow peak for $\theta$=6.6$^{\circ}C$/sec, have severe thermal instability, namely E$_3$, E$_4$and E$_{5}$ levels disappear during bleaching process. These defects in the optical grade LiF crystal seem annealed out during the course of TL measurement. The fresh or long time unused LiF(Mg) crystal shows only two glow peaks at 17$0^{\circ}C$ and 23$0^{\circ}C$ for $\theta$=6.6$^{\circ}C$/sec, but upon sensitization with r-ray irradiation, it converts to the six glow peak state. The four electron traps, E$_1$, E$_2$, E$_3$, and E$_{6}$ created by r-ray irradiation and corresponding to the glow peaks at T=10$0^{\circ}C$ 13$0^{\circ}C$, 15$0^{\circ}C$ and 29$0^{\circ}C$ are stable and not easily annealed out thermally, The sensitization essentially required to LiF(Mg) dosimeter is to give the crystal the stable six levels in the electron trap. In optical grade LiF, the plot between logarithm of total TL output versus logarithm of r-ray dose gives more supra-linear feature than that of LiF(Mg). However, if one takes the height of 12$0^{\circ}C$ glow peak(S=6.6$^{\circ}C$/sec), instead of the total TL output, the curve becomes close to that of LiF(Mg).

  • PDF

Target motion analysis of the respiratory gated guided radiotherapy in liver cancer patients using 4D-CT (4D-CT와 호흡동조시스템을 이용한 간암 환자의 방사선치료 표적 움직임 분석)

  • Dong, Kyung-Rae;Park, Byung-Soo;Kim, Sae-Sark;Kweon, Dae-Cheol;Goo, Eun-Hoe;Chung, Woon-Kwan
    • Journal of Radiation Protection and Research
    • /
    • v.35 no.2
    • /
    • pp.63-68
    • /
    • 2010
  • The ultimate goal of radiation treatment is to use enough radiation dosage in order to examine a tumor while protecting normal tissue. Respiratory guided radiotherapy is being clinically implemented to examine a given stabilized area in order to compensate for the problems of patient breathing. This study investigates the effects of breathing movements on 40 patients with liver cancer through the actual radiation therapy plan using 4D-CT and respiratory guided radiotherapy using RPM. Using a commercial RPM respiratory gating system 4D-CT, we acquired 4D CT on multislice helical CT scanners that use different approaches to 4D CT image reconstruction. The results from analyzing forty patients according to age and direction showed no relationship between gender and transition change. The mean left-right, anteroposterior, and craniocaudal total movements were $3.19{\pm}1.29$, $5.44{\pm}2.07$, and $12.54{\pm}4.70$ mm, respectively. Changes were the largest with CC directions and as patients advanced in age, movements were larger. Therefore, as changes occur in treatment areas because of movements caused from breathing, respiratory gating system is put into operation to revise movement and can increase the radiotherapeutics effects in treating liver cancer.

The Ages of Fault Activities of the Ilkwang Fault in Southeastern Korea, Revealed by Classification of Geomorphic Surfaces and Trench Survey

  • Ho, Chang;Ree, Jin-Han;Joo, Byung-Chan
    • The Korean Journal of Quaternary Research
    • /
    • v.18 no.2 s.23
    • /
    • pp.1-2
    • /
    • 2004
  • The Ilkwang Fault is NNE-striking, elongated 40 Km between Ulsan and Haendae-ku, Busan in southeastem part of the Korean Peninsula(Kim, D.H. et al., 1989; Kim, J.S. et al., 2003). This paper is mainly concemed about the ages of the fault activities especially in the Quatemary, infered from classification of geomorphic surface and trench excavation for the construction of Singori nuclear power plant. The geomorphi surfaces are classified into the Beach and the Alluvial plain, the 10 m a.s.l. Marine terrace, the 20 m a.s.l. Marine terrace, the Reworked surface of 45 m a.s.l. Marine terrace and the Low relief erosional surface, from lower to higher altitude. The Beach and the Alluvial plain are elongated to the Holocene terrace(ist terrace, choi, 2003). The 10 m a.s.l. Marine terrace is correlated to 2nd terrace (MIS 5em 125 Ka. y. B.P., Choi, 1998). The 45 m a.s.l. Marine terace is correlated to the Lower marine terrace (MIS 7,220 Ka. y. B.P., Choi, 2003 or MIS 9,320 y. B.P.) to the Gwanganri terrace(Penultimate interglacial age, 200-200 Ka. Y. B.P., Oh, 1981). The Low relief erosional surface is distributed coastal side, the Reworked surface of 45 m a.s.l. Marine terrace inland side by the Ilkwang Fault Line as the boundary line. But the former is above 10 m higher in relative height than the latter. The 20 m a.s.l. Marine terrace on the elongation line of the Ilkwang Fault reveals no dislocation. A site was trenched on the straight contract line with $N30^{\circ}$ E-striking between the 10 m a.s.l. Marine terrace and the 20 m a.s.l. Marine terrace. Fault line or dislocation was not observable in the trench excavation. Accordingly, the straight contact line is inferred as the ancient shoreline of the 10 m a.s.l. Marine terrace. The Ages of the Fault activities are inferred after the formation of the Ichonri Formation - before the formation of the 45 m a.s.l. Marine terrace (220 Ka. y. B.P. or 320 Ka. y. B.P.). The Low relief erosional surface was an island above the sea-level during the formation of the 45 m a.s.l. Marine terrace in the paleogeography.

  • PDF

Classification of Ultrasonic NDE Signals Using the Expectation Maximization (EM) and Least Mean Square (LMS) Algorithms (최대 추정 기법과 최소 평균 자승 알고리즘을 이용한 초음파 비파괴검사 신호 분류법)

  • Kim, Dae-Won
    • Journal of the Korean Society for Nondestructive Testing
    • /
    • v.25 no.1
    • /
    • pp.27-35
    • /
    • 2005
  • Ultrasonic inspection methods are widely used for detecting flaws in materials. The signal analysis step plays a crucial part in the data interpretation process. A number of signal processing methods have been proposed to classify ultrasonic flaw signals. One of the more popular methods involves the extraction of an appropriate set of features followed by the use of a neural network for the classification of the signals in the feature spare. This paper describes an alternative approach which uses the least mean square (LMS) method and exportation maximization (EM) algorithm with the model based deconvolution which is employed for classifying nondestructive evaluation (NDE) signals from steam generator tubes in a nuclear power plant. The signals due to cracks and deposits are not significantly different. These signals must be discriminated to prevent from happening a huge disaster such as contamination of water or explosion. A model based deconvolution has been described to facilitate comparison of classification results. The method uses the space alternating generalized expectation maximiBation (SAGE) algorithm ill conjunction with the Newton-Raphson method which uses the Hessian parameter resulting in fast convergence to estimate the time of flight and the distance between the tube wall and the ultrasonic sensor. Results using these schemes for the classification of ultrasonic signals from cracks and deposits within steam generator tubes are presented and showed a reasonable performances.

Study of Variation of Internal Taget Volume between 4DCT and Slow-CT in Respiratory Patterns Using Respiratory Motion Phantom (호흡 동조 구동 팬톰을 이용한 호흡패턴에 따른 4DCT, Slow-CT의 내부표적체적 변화 연구)

  • Lee, Soon Sung;Choi, Sang Hyoun;Min, Chul Kee;Ji, Young Hoon;Kim, Mi-Sook;Yoo, Hyoung Jun;Kim, Chan Hyeong;Kim, Kum Bae
    • Progress in Medical Physics
    • /
    • v.25 no.1
    • /
    • pp.53-63
    • /
    • 2014
  • The objective of this study is to investigate the difference of ITV lengths and ITVs between 4DCT and Slow-CT images according to respiratory patterns using a respiratory motion phantom. The respiratory periods 1~4 s and target motion 1~3 cm were applied on each respiratory pattern. 4DCT and Slow-CT images were acquired for 3 times. 4DCT and Slow-CT ITVs were measured with contouring the target in the Eclipse RTP system. The measured ITV lenghts and ITVs in 4DCT and Slow-CT images were compared to the known values. For the ITV lengths and ITVs in the 4DCT, the difference of them were reduced as the respiratory period is longer and target motion is shorter. For the Slow-CT, there was same tendency with change in 4DCT ITV lengths and ITVs about target motion. However, the difference of ITV lengths and ITVs for the respiratory periods were the lowest in respiratory period 1 second and different slightly within respiratory period 2-4 seconds. According to the respiratory patterns, pattern A had the highest reproducibility. Pattern B, C and D were showed the difference similar to each other. However, for pattern E, the reproducibility was the lowest compared with other four patterns. The difference of ITV lengths and ITVs between Slow-CT and 4DCT was increased by increasing the respiratory periods and target motion for all respiratory patterns. When the difference of Slow-CT ITV lengths and ITVs were compared with that of 4DCT ITV lengths and ITVs, Slow-CT ITV lengths and ITVs were approximately 22 % smaller than 4DCT, and the representations of target were different in each pattern. In case of pattern A, B and C, length difference was 3 mm at S (superior) and I (inferior) direction, and the length difference of pattern D was 1.45 cm at only "I" direction whereas the length difference of pattern E was 5 mm longer in "S" direction than "I" direction. Therefore, the margin in SI directions should be determined by considering the respiratory patterns when the margin of Slow-CT is compensated for 4DCT ITV lengths. Afterward, we think that the result of this study will be useful to analyze the ITV lengths and ITVs from the CT images on the basis of the patient respiratory signals.