A field study of colloid transport in surface and subsurface flows

Zhang, Wei,Tang, Xiang-Yu,Xian, Qing-Song,Weisbrod, Noam,Yang, Jae E.,Wang, Hong-Lan Elsevier, etc 2016 Journal of hydrology Vol.542 No.-

<P><B>Abstract</B></P> <P>Colloids have been recognized to enhance the migration of strongly-sorbing contaminants. However, few field investigations have examined combined colloid transport via surface runoff and subsurface flows. In a headwater catchment of the upper Yangtze River, a 6m (L) by 4m (W) sloping (6°) farmland plot was built by cement walls to form no-flow side boundaries. The plot was monitored in the summer of 2014 for the release and transport of natural colloids via surface runoff and subsurface flows (i.e., the interflow from the soil-mudrock interface and fracture flow from the mudrock-sandstone interface) in response to rain events. The water sources of the subsurface flows were apportioned to individual rain events using a two end-member model (i.e., mobile pre-event soil water extracted by a suction-cup sampler <I>vs</I>. rainwater (event water)) based on <I>δ</I> <SUP>18</SUP>O measurements. For rain events with high preceding soil moisture, mobile pre-event soil water was the main contributor (generally >60%) to the fracture flow. The colloid concentration in the surface runoff was 1–2 orders of magnitude higher than that in the subsurface flows. The lowest colloid concentration was found in the subsurface interflow, which was probably the result of pore-scale colloid straining mechanisms. The rainfall intensity and its temporal variation govern the dynamics of the colloid concentrations in both surface runoff and subsurface flows. The duration of the antecedent dry period affected not only the relative contributions of the rainwater and the mobile pre-event soil water to the subsurface flows but also the peak colloid concentration, particularly in the fracture flow. The <10μm fine colloid size fraction accounted for more than 80% of the total suspended particles in the surface runoff, while the colloid size distributions of both the interflow and the fracture flow shifted towards larger diameters. These results highlight the need to avoid the application of strongly-sorbing agrochemicals (e.g., pesticides, phosphorus fertilizers) immediately before rainfall following a long no-rain period because their transport in association with colloids may occur rapidly over long distances via both surface runoff and subsurface flows with rainfall.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Subsurface flow was apportioned into rainwater and mobile pre-event soil water. </LI> <LI> The duration of no-rain period affects peak colloid concentration. </LI> <LI> Rainfall intensity and its temporal variation govern colloid discharge dynamics. </LI> </UL> </P>

The prediction of the tooth size in the mixed dentition for Korean

Moon, Sung-Hwan,Kim, Seong-Oh,Yu, Hyung-Seong,Choi, Byung-Jai,Choi, Hyung-Jun,Lee, Jae-Ho 大韓小兒齒科學會 2006 大韓小兒齒科學會誌 Vol.33 No.2

이번 연구의 목적은 혼합치열기 아동에서 미맹출된 견치와 소구치의 크기를 예측하는데 있어서 한국인에 맞는 방정식을 만들기 위함이다. 미맹출 치아의 크기를 예측하는 것은 혼합치열기 교정 진단과 치료계획 수립에 있어서 매우 중요하다. 미맹출된 견치와 소구치 크기를 예측하는 방법은 몇가지가 있지만 그중에서도 가장 흔하게 쓰이는 것이 모이어의 예측표와 다나카와 존스턴의 방정식이 있다. 하지만 그것들은 백인을 위해서 제작된 것이고 치아 크기는 인종에 따라서 다르다고 알려져 있다. 이번 연구에서는 치아크기를 측정하여 하악 영구 절치의 크기 합과 견치 및 소구치의 크기 합 사이의 상관관계를 구하고 회귀방정식을 이용해서 한국인에 맞는 예측표를 만들었다. 연세대학교 치과대학에 재학중인 178명의 한국 학생(남 108명, 여 70명, 평균연령 21.63)을 대상으로 실험하였다. 영구치의 근원심 폭경을 석고모형상에서 calipers를 이용해서 측정하였다. 성별간의 치아 크기는 차이가 있었다(p<0.05). Correlation coefficient는 0.57에서 0.64의 범위였고, standard errors of the estimates 는 여성에서 0.6으로써 남성보다 우수하였다. r^(2)값은 0.27에서 0.41의 범위를 나타내었다. Estimating the size of unerupted teeth is an essential aspect of orthodontic diagnosis and treatment planning in the mixed dentition. Several methods were introduced and used for the prediction. The most common methods among these would be Moyers probability chart and Tanaka and Johnston equations. These are currently used widely, but they were developed for Caucasians. Because there are clear racial differences in teeth size, the objectives of this study were to produce correlation coefficients between the combined mesiodistal widths of the permanent mandibular incisors and those of the canines and premolars for each quadrant, and prediction tables with regression equations, specifically for Korean. 178 young adults (70 women, 108 men, mean age 21.63 years) were selected from the College of Dentistry, Yonsei University, Seoul, Korea. The mesiodistal crown diameters of the permanent teeth were measured with calipers. Significant sexual dimorphism was found in tooth sizes. The correlation coefficients between the total mesiodistal width of the mandibular permanent incisors and those of the maxillary and mandibular canines and premolars were found to be between 0.52 and 0.64. The standard error of the estimatation was better (0.60) for women and the r^(2) values ranged from 0.27 to 0.41 for both sexes, Prediction tables were prepared for Korean. This study showed larger canine and premolar diameters than Tanaka and Johnston's and Moyers' studies which might be due to the racial differences. Further investigations with a larger sample size will be needed for more representative data on the Korean population.

Withaferin A Inhibits Helicobacter pylori-induced Production of IL-1β in Dendritic Cells by Regulating NF-κB and NLRP3 Inflammasome Activation

Jae-Eun Kim,Jun-Young Lee,Min-Jung Kang,Yu-Jin Jeong,Jin-A Choi,Sang-Muk Oh,Kyung-Bok Lee,Jong-Hwan Park 대한면역학회 2015 Immune Network Vol.15 No.6

Facile polymer gate dielectric surface-modification for organic thin-film transistors using self-assembled surfactant layer

Yu, Seong Hoon,Cho, Jangwhan,Ha, Jae Un,Chung, Dae Sung Elsevier 2017 Organic electronics Vol.41 No.-

<P><B>Abstract</B></P> <P>We demonstrate facile polymer gate dielectric surface-modification method for organic thin-film transistors (OTFTs). We simply introduce self-assembled surfactant layer onto the top surface of poly(4-vinylphenol) (PVP) dielectric by spin coating PVP solution mixed with sodium dodecyl sulfate and tridecafluorohexane-1-sulfonic acid potassium salt as additive agents. The surfactant-modified PVP layer acquires various merits compared to pristine PVP layer in terms of surface smoothness and hydrophobicity, as confirmed by contact angle measurement, atomic force microscopy analyses, grazing incident X-ray diffraction and near-edge X-ray absorption fine structure spectroscopy. The resulting OTFTs with the conventional semiconducting poly(2,5-bis(3-hexadecylthiophen-2-yl)thieno[3,2-b]thiophene) as the active layer and surfactant-modified PVP as the dielectric layer reveal overall ascendency over the OTFT with pristine PVP, especially in terms of operating hysteresis and reliability. The effects of hydrophobicity of surfactants on the surface properties of PVP as well as the OTFT performances are fully discussed in conjunction with various characterization tools.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We demonstrate facile polymer gate dielectric surface-modification method for organic thin-film transistors. </LI> <LI> We introduce self-assembled surfactant layer onto the top surface of PVP dielectric. </LI> <LI> The surfactant-modified PVP acquires merits compared to pristine PVP in terms of surface smoothness and hydrophobicity. </LI> <LI> X-ray study supports the superiority of surfactant-modified PVP and proved the tendency of agglomeration of semiconductor. </LI> <LI> The surfactant-modified PVP show overall ascendency over the OTFT with pristine PVP in terms of hysteresis and reliability. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Heart rate recovery and diastolic blood pressure ratio on the treadmill test predict an induction and recurrence of vasovagal syncope

( Yu Jeong Choi ),( Ki-woon Kang ),( Sang Hyun Jang ),( Jae Guk Kim ),( Soo Joo Lee ),( Kyung Tea Jung ) 대한내과학회 2019 The Korean Journal of Internal Medicine Vol.34 No.2

Background/Aims: The induction and recurrence of syncope is a concerning situation that could be unpredicted in the vasovagal syncope (VVS). We investigated a simple predictor for the induced and recurrent VVS during Head-Up table-tilt Test (HUT) and clinically follow-up. Methods: The 143 consecutive patients with VVS (age 31 ± 19 years, 33 male) who referred by a cardiologist or neurologist and had undergone an echocardiogram, HUT, and a treadmill exercise test (TMT) were recruited and clinically follow-up. Patients were divided into two groups based on the result of HUT and TMT. The data was analyzed and compared between VVS patients and control 141 patients without VVS who were enrolled in the same study period (age 40 ± 5 years, 117 male). Results: The heart rate recovery (HRR), recovery systolic blood pressure (RecSBP), recovery diastolic blood pressure (RecDBP), HRR/RecSBP and HRR/RecDBP were significantly different between controls and VVS during the TMT. Within VVS, even if, baseline characteristics were similar between negative and positive HUT (n = 92 vs. n = 51). HRR (31 ± 10 vs. 35 ± 10), HRR/RecSBP (0.24 ± 0.09 vs. 0.28 ± 0.09) and HRR/RecDBP (0.49 ± 0.18 vs. 0.58 ± 0.19) were significantly different between negative and positive HUT results. Especially, HRR/RecSBP and HRR/RecDBP were significantly correlated with induced syncope with a sensitivity and specificity ([60%, 83%] cut-off, 0.31; [72%, 80%] cut-off, 0.63). In the Cox regression, HRR/ RecDBP were significantly associated with recurrence of VVS with hazard ratio of 3.29 (confidence interval, 0.95 to 11.3; p = 0.049). Conclusions: HRR/RecDBP may be a useful predictor for induction during HUT and recurrence during follow-up in the VVS.

Two cases of arterial embolization and skin necrosis following filler injection (초)

( Jae Yong Sung ),( Yu Ri Choi ),( In Kyung Jeon ),( Mi Ryung Roh ) 대한피부과학회 2011 초록집 Vol.49 No.10

Validation Study of an Operational Tolerance Signature in Korean Kidney Transplant Recipients

Yu Ho Lee,Jung-Woo Seo,Yang Gyun Kim,Ju-Young Moon,Jin Sug Kim,Kyung-Hwan Jeong,Bo-mi Kim,Kyoung Woon Kim,Chul Woo Yang,Chan-Duck Kim,Jae Berm Park,Yeong Hoon Kim,Byung Ha Chung,Sang-Ho Lee 대한면역학회 2018 Immune Network Vol.18 No.5

Fuzzy-Logic-Based Vector Control Scheme for Permanent-Magnet Synchronous Motors in Elevator Drive Applications

Jae-Sung Yu,Sang-Hoon Kim,Byoung-Kuk Lee,Chung-Yuen Won,Jin Hur IEEE 2007 IEEE transactions on industrial electronics Vol.54 No.4

<P>In elevator drive systems, the gains of a conventional proportional-integral (PI) speed controller cannot usually be set large enough because of its mechanical resonance. Consequently, the speed control performance deteriorates. In our work described in this paper, a fuzzy logic controller (FLC) was adopted for use in elevator drive systems in order to improve the speed control performance. The proposed FLC was compared with a conventional PI controller with respect to speed dynamic responses and load torque. Simulation and experimental results demonstrated that the proposed FLC was superior over the conventional PI. This FLC can be a good solution for high-performance elevator drive systems.</P>

Liquid Chromatography/Electrospray Ionization Tandem Mass Spectrometry-based Structural Analysis of Deacylated Lipooligosaccharides From Escherichia coli

Yu Ri Choi,Kwang Sung Kim,Raju Bandu,김효선,Jae Eun Lee,Byong-Kyu Shin,Yang Je Cho,박종문,Hookeun Lee,김광표 대한화학회 2020 Bulletin of the Korean Chemical Society Vol.41 No.4

Deacylated lipooligosaccharides (dLOSs) were developed as human vaccine adjuvants. The dLOSs have significant immune activities and markedly lower toxicities than their precursors, lipopolysaccharides (LPSs). In this study, we developed a novel liquid chromatography mass spectrometry (LC?MS) method for characterization of the dLOSs. The structural identification and characterization of the dLOSs were carried out using electrospray ionization tandem mass spectrometric experiments. Finally, we propose the most likely structure of the dLOSs as being composed of a diacyl form of lipid A with seven sugars, 3 HEP?+?2 KDO?+?1 GlcN?+?1 Glc.

A Study on the Enhanced Filtering for the Removal of BEMF in BLDC Motors

Yu-Sung Moon,Jae-Hyun Choi,Jung-Won Kim 한국전기전자학회 2019 전기전자학회논문지 Vol.23 No.1

This paper used the majority function to digitally filter back-electromotive force as an explanation of the Brushless DC MOTOR control algorithm. The cause and improvement of motor noise, which are operating in close proximity to high frequency sources, did not use conventional low pass filter and comparator elements. Also, they repeatedly output a noise-free BEMF signal for the input value of the majority detection filtering. These filtering steps can help reduce costs and minimize the area of a PCB by requiring relatively little hardware.