• Title/Summary/Keyword: $LN_2$

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Colossal Magnetoresistance in Chalcogenide Spinels $Ni_xFe_{1-x}Cr_2S_4(X = 0.05, 0.1, 0.2)$ (Spinel 유화물 $Ni_xFe_{1-x}Cr_2S_4(X = 0.05, 0.1, 0.2)$의 초거대자기저항(CMR)현상에 관한 연구)

  • 박재윤
    • Journal of the Korean Magnetics Society
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    • v.11 no.4
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    • pp.151-156
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    • 2001
  • Recently many studies on manganese oxides Ln$_{1-x}$A$_{x}$MnO$_3$(Ln=La, Pr, Nd lanthannide; A=Ca, Sr, Ba, Pb +2 ions) reported CMR properties. CMR have been also found in chalcogenide spinels. We have investigated that Ni ion substitutions for Fe ion have effects on CMR properties in chacogenide spinels Ni$_{x}$Fe$_{1-x}$Cr$_2$S$_4$. It was found that with increasing Ni concentration Jahn-Teller distortion was strengthened and Curie temperature T$_{c}$ was increased. CMR properties could be explained with Jahnl-Teller effect, half-metallic electronic structure, and the alignment of magnetic domain due to the strong magnetic field, which is different in that double exchange interactions dominate CMR properties in manganese oxides.

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Disinfection of E. coli Using Electro-UV Complex Process: Disinfection Characteristics and Optimization by the Design of Experiment Based on the Box-Behnken Technique (전기-UV 복합 공정을 이용한 E. coli 소독 : 실험계획법중 박스-벤켄법을 이용한 소독 특성 및 최적화)

  • Kim, Dong-Seog;Park, Young-Seek
    • Journal of Environmental Science International
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    • v.19 no.7
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    • pp.889-900
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    • 2010
  • The experimental design and response surface methodology (RSM) have been applied to the investigation of the electro-UV complex process for the disinfection of E. coli in the water. The disinfection reactions of electro-UV process were mathematically described as a function of parameters power ($X_1$), NaCl dosage ($X_2$), initial pH ($X_3$) and disinfection time ($X_4$) being modeled by use of the Box-Behnken technique. The application of RSM using the Box-Behnken technique yielded the following regression equation, which is an empirical relationship between the residual E. coli number and test variables in actual variables: Ln (CFU) = 23.57 - 0.87 power - 1.87 NaCl dosage - 2.13 pH - 2.84 time - 0.09 power time - 0.07 NaCl dosage pH + 0.14 pH time + 0.03 $power^2$ + 0.47 NaCl $dosage^2$ + 0.20 $pH^2$+ 0.33 $time^2$. The model predictions agreed well with the experimentally observed result ($R^2$ = 0.9987). Graphical response surface and contour plots were used to locate the optimum point. The estimated ridge of maximum response and optimal conditions for the E. coli disinfection using canonical analysis was Ln 1.06 CFU (power, 15.40 W; NaCl dosage, 1.95 g/L, pH, 5.94 and time, 4.67 min). To confirm this optimum condition, the obtained number of the residual E. coli after three additional experiments were Ln 1.05, 1.10 and Ln 1.12. These values were within range of 0.62 (95% PI low)~1.50 (95% PI high), which indicated that conforming the reproducibility of the model.

Worse Survival of Patients With T1 Stage II Gastric Cancer Following Radical Gastrectomy

  • Hayemin Lee;Kyo Young Song;Han Hong Lee;Junhyun Lee
    • Journal of Gastric Cancer
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    • v.23 no.4
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    • pp.598-608
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    • 2023
  • Purpose: Lymph node (LN) metastasis is a crucial factor in the prognosis of patients with gastric cancer (GC) and is known to occur more frequently in cases with an advanced T stage. This study aimed to analyze the survival data of patients with advanced LN metastasis in T1 GC. Materials and Methods: From January 2008 to June 2018, 677 patients with pathological stage II GC who underwent radical gastrectomy were divided into an early GC group (EG: T1N2 and T1N3a, n=103) and an advanced GC (AGC) group (AG: T2N1, T2N2, T3N0, T3N1, and T4aN0, n=574). Short- and long-term survival rates were compared between the 2 groups. Results: A total of 80.6% (n=83) of the patients in the EG group and 52.8% (n=303) in the AG group had stage IIA AGC. The extent of LN dissection, number of retrieved LNs, and short-term morbidity and mortality rates did not differ between the 2 groups. The 5-year relapse-free survival (RFS) of all patients was 87.8% and the overall survival was 84.0%. RFS was lower in the EG group than in the AG group (82.2% vs. 88.7%, P=0.047). This difference was more pronounced among patients with stage IIA (82.4% vs. 92.9%, P=0.003). Conclusions: T1 GC with multiple LN metastases seems to have a worse prognosis compared to tumors with higher T-stages at the same level. Adjuvant chemotherapy is highly recommended for these patients, and future staging systems may require upstaging T1N2-stage tumors.

Acid Production and Phytate Degradation using a Leuconostoc mesenteroides KC5l Strain in Saccharified-Rice Suspension (현미 당화액에서 Leuconostoc mesenteroides KC51 균주에 의한 산의 생성과 Phytate의 분해)

  • In, Man-Jin;Choi, Seo-Yeon;Kim, Hye-Rim;Park, Dan-Bi;Oh, Nam-Soon;Kim, Dong-Chung
    • Journal of Applied Biological Chemistry
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    • v.52 no.1
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    • pp.33-37
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    • 2009
  • A saccharified-rice was fermented using Leuconostoc(Ln.) mesenteroides KC51 strain in various dry matter (DM) contents (4%, 8%, and 12%) at $30^{\circ}C$ for 18 h. The changes of viable cell number, acid production and phytate degradation in saccharified-rice during fermentation were investigated. The viable cell population of Ln. mesenteroides KC51 was increased rapidly in proportion to DM contents during the 9 h of cultivation. The changes of pH and titratable acidity in saccharified-rice were dependent on DM contents. At high DM content (12%), the viable cell number of Ln. mesenteroides KC51 increased to 9.56 log CFU/g after 6 h of fermentation. The pH and titratable acidity reached to pH 3.38 and 0.93% after 18 h of fermentation, respectively. The phytate, known as an antinutrient factor, in saccharified-rice was degraded by Ln. mesenteroides KC51 cultivation. The decrease of phytate during fermentation approximately coincided with the increase of Ln. mesenteroides KC51 population observed in fermented saccharified-rice. Regardless of DM contents, the levels of phytate were reduced to around 50% of initial concentration.

The Effect of Venesection with Cupping Therapy at Jeonjung($CV_{17}$) on the Heart Rate Variability in Healthy Adults (전중혈(膻中穴)($CV_{17}$) 습부항요법이 정상 성인의 심박변이도(HRV)에 미치는 영향)

  • Kim, Seong Joung;Park, Jin Soo;Lee, Jeong Ju;Park, Ok Ju;Kim, Sul Gi;Jeong, Ho Hyun;Park, Min Cheol;Kwon, Young Mi;Jo, Eun Heui
    • Journal of Acupuncture Research
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    • v.30 no.4
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    • pp.15-24
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    • 2013
  • Objectives : This study was accomplished to investigate the effects of venesection with cupping therapy at Jeonjung($CV_{17}$) on the heart rate variability(HRV) in healthy adults. And based on that, we tried to find out how venesection with cupping therapy at Jeonjung($CV_{17}$) affects the activity and the balance of the autonomic nervous system. Methods : We investigated on 60 healthy volunteers consisted of 30 subjects in venesection with cupping therapy group and 30 subjects in control group. The study was established by randomized trial. venesection with cupping therapy was applied at Jeonjung($CV_{17}$) for 10 minutes in venesection with cupping therapy group. No treatment was executed in control group. We measured HRV 3 times : First, baseline measurement and two more times after treatment in venesection with cupping therapy group(after rest in control group). The SPSS 12.0 for Windows was used to analyze the data by paired t-test(in both group), independent-test(between the groups) and Chi-square test(between the sexs). Results : 1. In venesection with cupping therapy group, SDNN, Ln(TP), Ln(LF), Normalized LF, and LF/HF ratio increased significantly. Normalized HF decreased significantly. Mean HRT, RMSSD, PSI, Ln(HF), and Ln(VLF) were not affected. 2. In control group, Ln(HF) decreased significantly. Mean HRT, SDNN, RMSSD, PSI, Ln(TP), Ln(LF), Ln(VLF), Normalized LF, Normalized HF, and LF/HF ratio were not affected. Conclusions : This study suggests that venesection with cupping therapy at Jeonjung($CV_{17}$) increases the activity of the autonomic nervous system and has effects on the balance of the autonomic nervous system.

Comparative Morphology and Morphometry of the Olfactory Organ of Carassius auratus and Carassius cuvieri (Cypriniformes, Cyprinidae) (붕어 Carassius auratus와 떡붕어 Carassius cuvieri 후각기관의 형태 및 형태계측학적 비교 연구)

  • Hyun-Tae Kim;Jin-hui Lee
    • Korean Journal of Ichthyology
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    • v.35 no.3
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    • pp.171-176
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    • 2023
  • The olfactory organ of Carassius auratus and C. cuvieri was compared morphologically and morphometrically using stereomicroscopy and statistical program (SPSS version 18.0). The external morphology of the olfactory organ consists of the open semicircular anterior and posterior nostril, and nasal flap. The internal structure showed the oval rosette consisting of several lamellae arranged radiately. In statistical analysis of standard length (SL), olfactory lamellar number (LN), and SL/LN ratio between two species using independent two sample t-test and Pearson's correlation and coefficient, C. cuvieri is the longer SL than that of C. auratus and C. auratus LN (14~20) is lager than that of C. cuvieri (14~16) (P<0.001) and C. auratus LN/SL ratio (12.7±0.7%) is larger than that of C. cuvieri (8.2±0.6%). These results suggest that i) open semicircular nostrils is functional morphology to offset the boundary layer and ii) the lager LN of smaller C. auratus may be a morphological adaptation to reflect its higher olfactory dependence than C. cuvieri and iii) such interspecific difference in LN and LN/SL ratio could be applied as a new taxonomic trait for identification.

The Characteristics of Bubbles in a Column Heat Exchanger for the Application of Direct Contact LNG Evaporator (직접접촉식 LNG기화기 응용을 위한 칼럼 열교환기 기포특성에 관한 연구)

  • Kim, S.J.;Han, S.T.;Kim, J.B.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.3 no.2
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    • pp.142-151
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    • 1991
  • In the present investigation, it has been proposed to utilize a direct contact heat exchanger as an evaporator to solve the difficulties such as scaling, corrosion and law thermal efficiencies, associated with the conventional evaporator. Liquified nitrozen was utilized as a working fluid to investigate basic natures of bubble dynamics in the evaporator, and spray nozzles were adopted to inject liquified nitrozen into the spray column with varying flow rates of dispersed phase fluids. Experimentations were carried out in the range of $6.54{\times}10^{-4}kg/s$ - 0.030 kg/s for dispersed phase flow rates with one, three and five nozzle holes. Observing the bubble dynamics for the evaporator the feasibility of utilizing a direct contact heat exchanger as a LNG evaporator has been evaluated. The results show that no eruption phenomena was observed in the present investigation with $LN_2$ and the interface between $N_2$ bubbles and water was fully turbulent. It is believed that the high injection velocity of $LN_2$ through the spray nozzles provide good mixing effects for both heat and mass transfers between water and $N_2$ bubbles. Ice was formed on the surface of the spray nozzle for higher $LN_2$ flow rates. However, even in this case, it is observed that the ice was detached as soon as it was formed. Under the present experimental conditions, the shapes of $LN_2$ bubbles were in the spherical-cap region according to the Clift, Grace and Weber Graphs. The height of foam region caused by the breakup of larger bubbles keeps increasing with high injection velocities until it reaches it's maximum height.

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Investigation of LN2 Lubrication Effect in Cryogenic Machining -Part 3: Nitrogen Lubrication Mechanism related to Chip Microstructures- (초 냉각 가공에서의 LN2 의 감찰 효과 연구 -절삭 칩 미세 구조에 관한 나이트로젠 감찰-)

  • 전성찬;정우철
    • Proceedings of the Safety Management and Science Conference
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    • 2002.05a
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    • pp.221-225
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    • 2002
  • Machinability improvement by the use of liquid nitrogen in cryogenic machining has been reported in various studies. This has been mostly attributed to the cooling effect of liquid nitrogen. However, No study has been found in discussion on whether liquid nitrogen possesses lubrication effect in cryogenic cutting. This paper presents lubrication mechanism related to chip microstructure. The friction reduction was further reflected In larger shear angle and less secondary deformation in the chip microstructures.

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대구.경상북도의 지반특성

  • 김영수
    • Proceedings of the Korean Geotechical Society Conference
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    • 2004.03a
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    • pp.146-157
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    • 2004
  • 다짐에너지는 D-2 수정다짐과 5층 35회, 45회 및 65회로 변화시켜 다짐시험을 행하였고 이때 각 시료는 자연입도에 근접하게 동일입도로 조정 사용하였으며, 건조법 및 비반복법으로 흐트러진 시료를 사용하여 시험하였다. 다짐에너지를 변화시키면서 다짐 시험한 결과는 그림 1, 2와 같다. 이들 그림에 대하여 최소자승법으로 다음과 같은 관계식을 얻었다. $r_{dmax}$=0.9834+0.0312 ln(E) $W_{opt}$=54.25-0.3778E $r_{dmax}$=1.8494-0.0158 $W_{opt}$ e=-0.07576 ln(E) + 1.5443(중략)

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Lipid nanodispersion for parenteral drug delivery: in vitro characterization

  • Lee, Jung-Min;Choi, Sung-Up;Lee, Byoung-Moo;Lee, Sung-Jae;Choi, Young-Wook
    • Proceedings of the PSK Conference
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    • 2003.04a
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    • pp.295.2-295.2
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    • 2003
  • Lipid nanodispersion (LN) composed of biocompatible lipids and surfactants is an alternative parenteral drug delivery system especially for lipophilic drugs. It has been studied for versatile applications such as oral, parenteral, topical, ocular, vaccine, and peptide drug delivery. The purpose of this study was to produce a novel LN system for intravenous injection using the high pressure homogenization. (omitted)

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