• Title/Summary/Keyword: Boundary treatment

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Adsorption Characteristics of Brilliant Green by Coconut Based Activated Carbon : Equilibrium, Kinetic and Thermodynamic Parameter Studies (야자계 입상 활성탄에 의한 brilliant green의 흡착 특성 : 평형, 동력학 및 열역학 파라미터에 관한 연구)

  • Lee, Jong-Jib
    • Clean Technology
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    • v.25 no.3
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    • pp.198-205
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    • 2019
  • The adsorption equilibrium, kinetic, and thermodynamic parameters of brilliant green adsorbed by coconut based granular activated carbon were determined from various initial concentrations ($300{\sim}500mg\;L^{-1}$), contact time (1 ~ 12 h), and adsorption temperature (303 ~ 323 K) through batch experiments. The equilibrium adsorption data were analyzed by Langmuir, Freundlich, Temkin, Harkins-Jura, and Elovich isotherm models. The estimated Langmuir dimensionless separation factor ($R_L=0.018{\sim}0.040$) and Freundlich constant ($n^{-1}=0.176{\sim}0.206$) show that adsorption of brilliant green by activated carbon is an effective treatment process. Adsorption heat constants ($B=12.43{\sim}17.15J\;mol^{-1}$) estimated by the Temkin equation corresponded to physical adsorption. The isothermal parameter ($A_{HJ}$) by the Harkins-Jura equation showed that the heterogeneous pore distribution increased with increasing temperature. The maximum adsorption capacity by the Elovich equation was found to be much smaller than the experimental value. The adsorption process was best described by the pseudo second order model, and intraparticle diffusion was a rate limiting step in the adsorption process. The intraparticle diffusion rate constant increased because the dye activity increased with increases in the initial concentration. Also, as the initial concentration increased, the influence of the boundary layer also increased. Negative Gibbs free energy ($-10.3{\sim}-11.4kJ\;mol^{-1}$), positive enthalpy change ($18.63kJ\;mol^{-1}$), and activation energy ($26.28kJ\;mol^{-1}$) indicate respectively that the adsorption process is spontaneous, endothermic, and physical adsorption.

Fates of water and salts in non-aqueous solvents for directional solvent extraction desalination: Effects of chemical structures of the solvents

  • Choi, Ohkyung;Kim, Minsup;Cho, Art E.;Choi, Young Chul;Kim, Gyu Dong;Kim, Dooil;Lee, Jae Woo
    • Membrane and Water Treatment
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    • v.10 no.3
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    • pp.207-212
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    • 2019
  • Non-aqueous solvents (NASs) are generally known to be barely miscible, and reactive with polar compounds, such as water. However, water can interact with some NASs, which can be used as a new means for water recovery from saline water. This study explored the fate of water and salt in NAS, when saline water is mixed with NAS. Three amine solvents were selected as NAS. They had the same molecular formula, but were differentiated by their molecular structures, as follows: 1) NAS 'A' having the hydrophilic group ($NH_2$) at the end of the straight carbon chain, 2) NAS 'B' with symmetrical structure and having the hydrophilic group (NH) at the middle of the straight carbon chain, 3) NAS 'C' having the hydrophilic group ($NH_2$) at the end of the straight carbon chain but possessing a hydrophobic ethyl branch in the middle of the structure. In batch experiments, 0.5 M NaCl water was blended with NASs, and then water and salt content in the NAS were individually measured. Water absorption efficiencies by NAS 'B' and 'C' were 3.8 and 10.7%, respectively. However, salt rejection efficiency was 98.9% and 58.2%, respectively. NAS 'A' exhibited a higher water absorption efficiency of 35.6%, despite a worse salt rejection efficiency of 24.7%. Molecular dynamic (MD) simulation showed the different interactions of water and salts with each NAS. NAS 'A' formed lattice structured clusters, with the hydrophilic group located outside, and captured a large numbers of water molecules, together with salt ions, inside the cluster pockets. NAS 'B' formed a planar-shaped cluster, where only some water molecules, but no salt ions, migrated to the NAS cluster. NAS 'C', with an ethyl group branch, formed a cluster shaped similarly to that of 'B'; however, the boundary surface of the cluster looked higher than that of 'C', due to the branch structure in solvent. The MD simulation was helpful for understanding the experimental results for water absorption and salt rejection, by demonstrating the various interactions between water molecules and the salts, with the different NAS types.

Development of Optimal Chlorination Model and Parameter Studies (최적 염소 소독 모형의 개발 및 파라미터 연구)

  • Kim, Joonhyun;Ahn, Sooyoung;Park, Minwoo
    • Journal of Environmental Impact Assessment
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    • v.29 no.6
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    • pp.403-413
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    • 2020
  • A mathematical model comprised with eight simultaneous quasi-linear partial differential equations was suggested to provide optimal chlorination strategy. Upstream weighted finite element method was employed to construct multidimensional numerical code. The code was verified against measured concentrations in three type of reactors. Boundary conditions and reaction rate were calibrated for the sixteen cases of experimental results to regenerate the measured values. Eight reaction rate coefficients were estimated from the modeling result. The reaction rate coefficients were expressed in terms of pH and temperature. Automatic optimal algorithm was invented to estimate the reaction rate coefficients by minimizing the sum of squares of the numerical errors and combined with the model. In order to minimize the concentration of chlorine and pollutants at the final usage sites, a real-time predictive control system is imperative which can predict the water quality variables from the chlorine disinfection process at the water purification plant to the customer by means of a model and operate the disinfection process according to the influent water quality. This model can be used to build such a system in water treatment plants.

Gingival pigmentation treatment using Er;YSGG laser (Er;YSGG 레이저를 이용한 치은 색소침착 제거 증례보고)

  • Kim, Hyunjong
    • Journal of the Korean Academy of Esthetic Dentistry
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    • v.30 no.2
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    • pp.53-58
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    • 2021
  • The attractiveness of the gingiva is determined by its color, shape, and the shape and location of the boundary between the teeth and the gingival tissue. The standards beauty, balance, and health of the gingiva are all different, but the general public would agree that a coral pink gingiva is more beautiful than black or brown gingiva. Hence, one would be able to smile more confidently in public if he or she receives a gingival pigmentation removal surgery that changes the color of black or brown gums to a beautiful pink color with relative simplicity. The color of one's gingiva varies from pale pink to deep bluish purple, depending on many health components. The most prominent among these include the vascular supply, epithelial thickness, the degree of keratinization, and the presence of pigment in the epithelium. Melanin, carotene, reduced hemoglobulin, and oxyhemoglobulin are the main pigments contributing to the normal color of the oral mucosa. The health of one's gingival tissue are essential for an attractive smile. Excessive melanin deposits in the basal and early basal layers of the epithelium stored in the form of melanosomes frequently cause pigmentation. Although there are many different procedures to remove this pigmentation, the it was removed using the Er;YSGG laser. It is my wish that, through this case study, many people

Tributyltin Induces Adipogenesis and Apoptosis of Rat Thymic Epithelial Cells (Tributyltin에 의한 흰쥐 흉선 내 상피세포의 지방세포 유도와 세포자연사 증가)

  • Lee, Hyo-Jin;Lee, A-Ra;Ahn, Bo-Ram;Jeon, Eun-Je;Jeong, Ye-Ji;Yang, Hyun-Won
    • Development and Reproduction
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    • v.15 no.4
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    • pp.373-383
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    • 2011
  • Tributyltin (TBT) is one of endocrine disrupters which are known as having similar function to sex steroid hormone inducing apoptosis in various tissues of rodents. Recently, it has been reported that TBT induces apoptosis in thymus causing the decreased thymic function, but little is known about the mechanism. To elucidate the mechanism, three-week-old SD female rats were orally administrated with TBT 1, 10, and 25 mg per body weight (kg) and sesame oil as a control for 7 days. On day 8, the thymi were obtained and weighed, and then the number of thymocytes was counted. We also performed H&E staining, TUNEL assay, and Annexin V flow cytometric analysis to examine the apoptosis rates and the structure in the thymus. Next, we investigated the adipogenesis and apoptosis-related mRNA expression levels in the thymi by real-time PCR. The thymic weight and the number of thymocytes were decreased by TBT in a dose-dependent manner. As a result of the H&E staining, the boundary between cortical and medullary area was blurred in the thymi of TBT treated rats compared to those of controls. In the results of TUNEL assay and Annexin V flow cytometric analysis, apoptosis rates in the thymus were increased after TBT treatment. The expression levels of thymic epithelial cell marker genes such as EVA, KGF, AIRE, and IL-7 were significantly decreased in the thymi of TBT treated rats, but $PPAR{\gamma}$, aP2, PEPCK, and CD36 were significantly increased. The expression of $TNF{\alpha}$ and TNFR1 as apoptosis-related genes also was significantly increased after TBT treatment. The present study demonstrates that TBT can increase the expression of adipogenesis and apoptosis-related genes leading to apoptosis in the thymus. These results suggest that the increased adipogenesis of thymus by TBT exposure might induce apoptosis in the thymus resulting in a loss in thymic immune function.

Treatment Margin Assessment using Mega-Voltage Computed Tomography of a Tomotherapy Unit in the Radiotherapy of a Liver Tumor (간종양 방사선치료 시 토모테라피 메가볼트 CT를 이용한 치료 여백 평가)

  • You, Sei-Hwan;Seong, Jin-Sil;Lee, Ik-Jae;Koom, Woong-Sub;Jeon, Byeong-Chul
    • Radiation Oncology Journal
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    • v.26 no.4
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    • pp.280-288
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    • 2008
  • Purpose: To identify the inter-fractional shift pattern and to assess an adequate treatment margin in the radiotherapy of a liver tumor using mega-voltage computed tomography (MVCT) of a tomotherapy unit. Materials and Methods: Twenty-six patients were treated for liver tumors by tomotherapy from April 2006 to August 2007. The MVCT images of each patient were analyzed from the $1^{st}$ to the $10^{th}$ fraction for the assessment of the daily liver shift by four groups based on Couinard's proposal. Daily setup errors were corrected by bony landmarks as a prerequisite. Subsequently, the anterior-, posterior-, right-, and left shifts of the liver edges were measured by maximum linear discrepancies between the kilo-voltage computed tomography (KVCT) image and MVCT image. All data were set in the 2-dimensional right angle coordinate system of the transverse section of each patient's body. Results: The liver boundary shift had different patterns for each group. In group II (segment 2, 3, and 4), the anterior mean shift was $2.80{\pm}1.73\;mm$ outwards, while the left mean shift was $2.23{\pm}1.37\;mm$ inwards. In group IV (segment 7 and 8), the anterior-, posterior-, right-, and left mean shifts were $0.15{\pm}3.93\;mm$ inwards, $3.15{\pm}6.58\;mm$ inwards, $0.60{\pm}3.58\;mm$ inwards, and $4.50{\pm}5.35\;mm$ inwards, respectively. The reduced volume in group II after MVCT reassessment might be a consequence of stomach toxicity. Conclusion: Inter-fractional liver shifts of each group based on Couinard's proposal were somewhat systematic despite certain variations observed in each patient. The geometrical deformation of the liver by respiratory movement can cause shrinkage in the left margins of liver. We recommend a more sophisticated approach in free-breathing mode when irradiating the left lobe of liver in order to avoid stomach toxicity.

Characteristic of Odorous Compounds Emitted from Livestock Waste Treatment Facilities Combined Methane Fermentation and Composting Process (메탄발효와 퇴비화 공정이 연계된 가축분뇨 처리시설에서 발생되는 악취물질 특성 조사)

  • Ko, Han Jong;Kim, Ki Youn;Kim, Hyeon Tae;Ko, Moon Seok;Higuchi, Takasi;Umeda, Mikio
    • Journal of Animal Science and Technology
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    • v.50 no.3
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    • pp.391-400
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    • 2008
  • Odor management is significantly concerned with sustainable livestock production because odor nuisance is a primary cause for complaint to neighbors. This study was conducted to measure the concentration of odorous compounds, odor intensity, and odor offensiveness at unit process in animal waste treatment facility combined composting and methane fermentation process by an instrumental analysis and direct olfactory method. Ammonia, sulfur-containing compounds, and volatile fatty acid were analyzed at each process units and boundary area in summer and winter, respectively. Higher concentration of odorants occurred in the summer than in the winter due to high ambient temperature. The maximum concentration of odorants was detected in composting pile when mixed manure was being turned followed by inlet, curing, outlet, and screen & packing process. Highest concentration of detected odorous compounds was ammonia ranging from 3.4 to 224.7 ppm. Among the sulfur-containing compounds measured, hydrogen sulfide was a maximum level of 2.3 ppm and most of them exceeded reported odor detection thresholds. Acetic acid was the largest proportion of VFA generated, reaching a maximum of 51 to 89%, followed by propionic and butyric acid at 1.9 to 35% and 1.8 to 15%, respectively. Malodor assessment by a human panel appeared a similar tendency in instrumental analysis data. Odor quotient for predicting major odor-causing compounds was calculated by dividing concentrations measured in process units by odor detection thresholds. In the composting process, hydrogen sulfide, ammonia, dimethyl sulfide, and methyl mercaptan were deeply associated with odor-causing compounds, while the major malodor compounds in the inlet process were methyl mercaptan, hydrogen sulfide, and butyric acid.

A Study of Mac(脈)-Theory and Change of Mac(脈)-Diagnosis in Whang Di Nei Qing(黃帝內經) (황제내경(黃帝內經)의 맥(脈) 이론(理論)과 진맥법(診脈法)의 변화(變化)에 관(關)한 연구(硏究))

  • Ra, Kyoung-Chan;Park, Hyun Kook
    • The Journal of Dong Guk Oriental Medicine
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    • v.2 no.1
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    • pp.73-105
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    • 1993
  • To say nothing of the orient and the west, the human beings discover the method of Jin Mac(診脈) by the way that observe disease. But oriental medicine devise special method of Jin Mac(診脈) in the study of Kyoung Mac(經脈). Although sip-ei Kyoung Mac Jin(十二經脈診), Sam Bu Gu Who Jin(三部九候診), In Young Mac Gu Jin(人迎脈口診), Chon Kwan Chuck Jin(寸關尺診) namely Yuk Bu Jung Wee Jin Mac (六部定位診脈) that is used today are devised, it has changed naturally by the changing treatment and the introduction of Yuin Yang(陰陽) and five element(五行). Many methods dg Jin Mac(診脈), it had not developped successing alternative, it had developped of declined by it's own way. 1. Results for the birth of Mac(脈) 1) Mac(脈), it means Kyoung Mac(經脈), at first entirelly Mac(脈), is seized a blood vessel that flows in the body. As presumed today, after finding many acupunture point, a general idea of Mac(脈) is not maked by the line that connect point and point, it connect between acupunture point and acupunture point. 2) Like blood flows in Hyul Mac(血脈), Gie(氣) flows in Kyoung Mac(經脈). The two things relate deeply each other. In a general idea or actrally Kyoung Rak(經洛), the two things sometimes accord, sometimes seperate, sometimes mix alternative. 3) Hyul Mac(血脈) and Kyoung Mac(經脈), we call it Mac(脈) entirely Kyoung Mac(經脈), is a way that manifest disease through Kyoung Mac(經脈) or a boundary that disease belongs to it method of Mac Jin(脈診) individual that disease of Kyoung Mac(經脈) is diagnosed by the jumping situation of Hyul Mac(血脈). 4) In method of Moxa, athough the pathology and the diagnostic of Mac(脈) are created by finding Mac(脈). Finding acupunture have opportunitty fot Mac Jin(脈診) and treatment. 2. Results of Kyoung Mac Mac Jin(經脈脈診) 1) In theory of kyoung Rak(經洛), disease are resumed for malfunction of Young Wee(榮衛) that flows in Kyung Rak(經洛). So to speak, in treatment of Kyoung Rak area, the purpose of diagnosis observe the situation of disease and cause. For fitting the purpose of diagnosis, the dead had esatablised four-diagnosis method mangMunMnnJeul(望聞問切), in four-diagnosis(四診法), the core is Mac Jin(脈診). 2) sip-ei Kyoung Mac Mac Jin(十二經脈診) had existed as Kyoung Mac Mac Jin(經脈脈診), it precedes Sam Bu Gu Who Jin(三部九候診). In Young Ki Gu Mac(人迎脈口診). 3) Although Bu Yang Mac(趺陽脈), So Um Mac(少陰脈) is a part of Sip-ei Kyoung Mac(十二經脈診), they developped especially because they located in the point of Won Hyul(原穴) and they are convenient for diagnose. 4) Sip-ei Kyoung Mac Mac Jin(十二經脈診), which belongs to Bu Yang Mac(趺陽脈) and So Urn Mac(少陰脈), is not important for the comming age medical books compared with Mac Kyoung(脈經). 3. Results gor Sam Bu Gu Who Jin(三部九候診) 1) Mac Jin(脈診) of Sam Bu Gu Who(三部九候), which is noted in the theory of Sam Bu Gu Who(三部九候診) of So Mun(素問), belongs to Kyoung Mac Mac Jin's(經脈脈診) geneology, Sip-ei Kyoung Mac Mac Jin(十二經脈診) is arranged, simplicated by the idealogy three talents(三才思想) in the heaven and the earth. 2) What Sam Bu Gu Jin(三部九候診) is regardded as very important in So Mun(素問), the editor of So Mun(素問) recognize the meaning that one discover disease early in this method of diagnosis. 3) After Young chu(靈樞), Nan Kyoung(難經) it is lacked the method of Sam Bu Gu Who Jin(三部九候診) in the books that treatment has changed. Sam Bu Gu Who Jin(三部九候診) based on actually clinic appropriate. 4. results for In Young Mac Gu Jin(人迎脈口診) 1) In Young Mac Gu Jin(人迎脈口診) is the method of comparative Mac Jin(脈診) according to the theory of Yin Yang(陰陽), it is presumed after Sam Bu Gu Who Jin(三部九候診), it had perished in parallel with the development of the theory of five elelment(五行). The development of the acupunture, the perishment of the treatment of negative(刺絡). 2) In Young Mac Gu Jin(人迎脈口診), Wang Suk Wha(王叔和) recreated that the left is In Young(人迎), the right is Kie Gu(氣口). In future generations by Jin Mu Taek(陳無擇) who is the writer of Sam In Bang(三因方). In Young Mac Gu Jin(人迎脈口診) is a measure for disease which classify it's inside and outside cause. 5. Results for Chon Gu Mac Jin(寸口脈診) 1) What we say Mac Jin(脈診) of Chon Gu(寸口) two means are used in commn. First case, we simply say the area of Chon Gu(寸口), second case, we say Chon Kwan Chuk Jin(寸口尺診) reducingly. Chon Gu(寸口) is the area which is the radial artery of wrist joint. What we attemp diagnose by only Chon Gu Mac(寸口脈), it is clearly shoued in the method of Nan Kyoung, five Nan(難經五難). 2) Because Jin Mac(診脈) is made in only Chon Gu(寸口), that is the area in which is concentated Kyoung Kee(經氣). That is the birth of Jin Kee(眞氣) and Jin Kee(眞氣) is related with disease. We can diagnose disease by taking Chon Gu(寸口). 3) Chuk Jin(尺診) in Nae Kyoung(難經) have two things. One is Il Chuk(一尺), the other is Chon Kwan Chu(寸關尺). 4) Chuk Chon Jin(尺寸診) is the method which diagnose the difference of point and the condition of Mac(脈) by dividing a part of Chuk(尺) in the area of Chon Gu(寸口). In Chon Gu Jin(寸口診), by introducing the theory of Yin Yang(陰陽), the method of Chon Gu Jin(寸口診) is developed by chon Gu Jin(寸口診). 5) What Chuk Kwan Chon Jin(寸關尺診) is that area of the Chon Gu(寸口) are divided fot three point, we can diagnose. By consulting Sam Bu Gu Who Jin(三部九候診), developping of the method of acupunture, utilzing the theory of five element(五行) it is devised by concentrating way of thinking of the method mac Jin(脈診) exiting. 6) Chon Kwan Chuk Jin MaC(寸關尺診脈) begin from Nae Kyoung(內徑) exiting. After Nan Kyoung(內徑), spread out widely from Mac Kyoung(脈診) of Wang Suk wha(王叔和), the future medicins followed it. Yang Hyun Jo(楊玄操) and established Chon Kwan Chuk Jin(寸關尺診) which is used widely today. This right and left Chon Kwan Chuk Jin(寸關尺診), we call it method of Yuk Bu Jung Wee Jin Mac(六部定位診脈). 7) We can think the base which presume the arrangement of the viscera for Chon Kwan Chuk(寸關尺) of the right and the left. 8) The origin, which seperate the right and the left of Mac(脈), is showed at the treory of Ji Jin Yo Dae(至眞要大論) in So Mun(素問) which Chon Chuk(寸尺) seperate the right and the left. But the method of diagnosis in Nan Kyoung(難經) have no seperation the fight and the left. Otherwise this. there is clearly writtened the seperation for the right origin of the method of Yuk Bu Jung Wee Jin Mac(六部定位診脈) seek for Cang Gong(倉公). 9) Yang Hyun Jo(楊玄操) notice that the Chuk(尺) is mentioned for Sam Cho(三焦) in the method of Mac Kyuong(脈經), Sim Po Kyung(心包經) which put together with Sam Cho(三焦) allot on this, he had established the method of Yuk Bu Jung Wee Jin Mac(六部定位診脈). 10) On the method of Paen Jak Yin Yang Mac(扁鵲陰陽脈) in Mac Kyoung(脈經), equal article exist with the theory of Pyung In Kee Sang(平人氣象論) in So Mun(素問). When Wang Suk Wha(王叔和) write Mac Kyung(脈經), we can presume that the book of Mac(脈) which Paen Jak(扁鵲) had experienced the origin have exited besides So Mun(素問), Young Chu(靈樞). If so he must be make Chon Kwan Chuk Jin(寸關尺診) very fairly standard. So Nae Kyoung(內經), which must be fllowed the method of Paen Jak Mac(扁鵲脈), do the method diagnosis of Chon Kwan Chuk(寸關尺), diagnise of disease and treat.

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The Limnological Survey of Major Lakes in Korea (4): Lake Juam (국내 주요 호수의 육수학적 조사(4) : 주암호)

  • Kim, Bom-Chul;Heo, Woo-Myung;Lim, Byung-Jin;Hwang, Gil-Son;Choi, Kwang-Soon;Choi, Jong-Soo;Park, Ju-Hyun
    • Korean Journal of Ecology and Environment
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    • v.34 no.1 s.93
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    • pp.30-44
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    • 2001
  • In this study limnological characteristics of Lake Juam was surveyed from June 1993 to May 1994 in order to provides important information regarding water resources. Secchi disc transparency, epilimnetic chlorophyll a (chi-a), total nitrogen (TN), total phosphorus (TP) concentration and primary productivity were in the range of $2.0{\sim}4.5\;m$, $0.9{\sim}13.6\;mgChl/m^3$, 0.78$\{sim}$2.32 mgN/l, $11{\sim}56\;mgP/m^3$, $270{\sim}2.160\;mgCm^{-2}\;day^{-1}$, respectively. On the basis of TP, Chl-a and Secchi disc depth, the trophic state of Lake Juam can be classied as mesotrophic lake. The phosphorus inputs from non-point sources are concentrated in heavy rain episodes during the monsoon season. As a result, phosphorus concentration are higher in summer than in winter. TP loading from the watershed were estimated to be $0.9\;gPm^{-2}yr^{-1}$, which correspond to a boundary of the critical loading ($1.0\;gPm^{-2}yr^{-1}$) for eutrophication. From the results of the algal assay, both phosphous and nitrogen act as limiting nutrients in algal growth. The seasonal succession of phytoplankton community structure in Lake Juam was similar to that observed in other temperate lakes. Diatoms (Asterionella formosa and Aulacoseira granulate var. angustissima)fujacofeira BraHuJafa uar. aHgusHrsiaia) weredominant in spring and winter, cyanobacteria) were dominant in warm season. The organic carbon, nitrogen and phosphorus content of lake sediment were $9.5{\sim}14.0\;mgC/g$, $1.01{\sim}1.82\;mgN/g$ and $0.51{\sim}0.65\;mgP/g$, respectively. The allochthonous organic carbon loading from the watershed and autochthonous organic carbon loading by primary production of phytoplankton were determined to be 1,122 tC/yr and 6,718 tC/yr, respectively. To prevent eutrophication of Lake Juam, nutrient management of watershed should be focus on reduction of fertilizer application, proper treatment of manure, and conservation of topsoil as well as point source.

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Evaluation of the reconstruction of image acquired from CT simulator to reduce metal artifact (Metal artifact 감소를 위한 CT simulator 영상 재구성의 유용성 평가)

  • Choi, Ji Hun;Park, Jin Hong;Choi, Byung Don;Won, Hui Su;Chang, Nam Jun;Goo, Jang Hyun;Hong, Joo Wan
    • The Journal of Korean Society for Radiation Therapy
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    • v.26 no.2
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    • pp.191-197
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    • 2014
  • Purpose : This study presents the usefulness assessment of metal artifact reduction for orthopedic implants(O-MAR) to decrease metal artifacts from materials with high density when acquired CT images. Materials and Methods : By CT simulator, original CT images were acquired from Gammex and Rando phantom and those phantoms inserted with high density materials were scanned for other CT images with metal artifacts and then O-MAR was applied to those images, respectively. To evaluate CT images using Gammex phantom, 5 regions of interest(ROIs) were placed at 5 organs and 3 ROIs were set up at points affected by artifacts. The averages of standard deviation(SD) and CT numbers were compared with a plan using original image. For assessment of variations in dose of tissue around materials with high density, the volume of a cylindrical shape was designed at 3 places in images acquired from Rando phantom by Eclipse. With 6 MV, 7-fields, $15{\time}15cm2$ and 100 cGy per fraction, treatment planning was created and the mean dose were compared with a plan using original image. Results : In the test with the Gammex phantom, CT numbers had a few difference at established points and especially 3 points affected by artifacts had most of the same figures. In the case of O-MAR image, the more reduction in SD appeared at all of 8 points than non O-MAR image. In the test using the Rando Phantom, the variations in dose of tissue around high density materials had a few difference between original CT image and CT image with O-MAR. Conclusion : The CT images using O-MAR were acquired clearly at the boundary of tissue around high density materials and applying O-MAR was useful for correcting CT numbers.