EPR Lineshape and g-Factor of the Single Crystal $Mn_xSi_{1-x}$

Son, Phil-Kook,Hwang, Young-Hun,Heo, Kyong-Chan,Kim, Hung-Cheol,Ok, Chi-Il,Um, Young-Ho,Kim, Jang-Whan Korean Magnetic Resonance Society 2004 Journal of the Korean Magnetic Resonance Society Vol.8 No.1

We have measured the linewidth and g-factor of EPR signals of the single crystal Mn$_{x}$Si$_{1-x}$ as a function of Mn-composition (0.4$\leq$x$\leq$0.9). We have investigated the linewidth of Mn$_{0.49}$Si$_{0.51}$ as a function of temperature (100 $\leq$ T $\leq$ 300 K). From these results EPR linewidth equation could be fitted for experimental data of EPR linewidth. This type of equation is similar to the shape of EPR linewidth of DMS (dulite magnetic semiconductor).or).r).

Facile preparation of a zinc-based alloy composite as a novel anode material for rechargeable lithium-ion batteries

Hung, Nguyen Thanh,Bae, Joonwon,Kim, Ji Hyeon,Son, Hyung Bin,Kim, Il Tae,Hur, Jaehyun Elsevier 2018 APPLIED SURFACE SCIENCE - Vol.429 No.-

<P><B>Abstract</B></P> <P>We report a new Zn-based nanocomposite anode material (Zn-Ti-C) for lithium-ion batteries synthesized by thermal treatment and a high energy mechanical milling process. X-ray diffraction and high-resolution transmission electron microscopy revealed the formation of active Zn nanoparticles finely dispersed in the hybrid titanium carbide (TiC) and carbon matrix. Electrochemical analyses show that the formation of the TiC and carbon buffer matrix significantly contributed to the improved performance of the Zn-based electrode by mitigating the volume changes of the Zn nanoparticles during the charge/discharge processes. Furthermore, we optimized the stoichiometric ratio of Zn and Ti in terms of specific capacity, cycling performance, and rate capability in the presence of carbon. The material with a 2:1 atomic ratio (ZnTi(2:1)-C) exhibited the best cycle life, with a gravimetric capacity of 363.6mAhg<SUP>−1</SUP> and a volumetric capacity of 472.7mAhcm<SUP>−3</SUP> after 300 charge/discharge cycles (78.1% retention). At this ratio, Zn-Ti-C consistently showed the best rate capability measurements up to 3000mAg<SUP>−1</SUP> (85% of its capacity at 100mAg<SUP>−1</SUP>). Therefore, our Zn-Ti-C composite is a promising alternative negative electrode material for lithium-ion batteries.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We fabricated a new Zn-based nanocomposite (Zn-Ti-C) alloy anodes by high-energy mechanical milling for use in lithium-ion batteries. </LI> <LI> The electrochemical performances of various Zn-based nanocomposites (Zn, Zn-Ti, and Zn-Ti-C with different ratios) were investigated. </LI> <LI> We found ZnTi(2:1)-C showed the best electrochemical performances in terms of specific capacity, cyclic performances, and rate capabilities. </LI> <LI> The mechanism of formation of Zn-TiC-C from Zn-Ti-C was examined by using XRD, TEM, and DCP data. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>We fabricated the high performances of Zn-TiC-C nanocomposite alloy anodes using high-energy mechanical milling for use in lithium-ion batteries.</P> <P>[DISPLAY OMISSION]</P>

Difference of Pinch Strength According to Testing Posture and Various Flexion Degree of Elbow Joint

Hang Eun Lee,Jin Kyu Yang,Jin Hee Son,Bo Young Hwang,Mun Kyo Kim,Mi Suk Ha,Jae Heon Kim 국제물리치료학회 2010 Journal of International Academy of Physical Ther Vol.1 No.2

The purpose of this study was to determine the difference of the pinch strength according to testing posture(standing and sitting) and elbow flexion degree(0。, 45。, 90。and 135。). Forty normal young adults(male: 20, female: 20, mean age: 22.68±2.91 years) participated in this study. The methods of this study were categorized as follows: 1) One set of measurement was performed on four elbow flexion degrees(0。, 45。, 90。and 135。) in two testing postures(standing and sitting) and all subjects were measured for 3 sets testing procedures in every experimental sessions. 2) Pinch strength in various elbow flexion degree was measured after 2 min rest time, and then each test set was repeatedly performed with 5 min rest time to prevent fatigue of muscles involved in the elbow joint. The result was obtained as follow: 1) In standing posture, there was statistically significant difference at 0。and 45。, 0。and 90。, 0。and 135。, 45。and 90。, 45。and 135。, 90。and 135。. 2) In sitting posture, there was statistically significant difference at 0。and 45。, 0。and 90。, 0。and 135。, 45。and 90。, 45。and 135。, 90。and 135。. 3) Statistically, there was no significant difference between standing and sitting posture in same elbow flexion degree, however pinch strength in standing posture was higher than sitting posture.

Sb-Al<i> _x </i>C<i> _y </i>-C Nanocomposite Alloy Anodes for Lithium-Ion Batteries

Hung, Nguyen Thanh,Park, Sung-Hoon,Bae, Joonwon,Yoon, Young Soo,Kim, Ji Hyeon,Son, Hyung Bin,Lee, Daeho,Kim, Il Tae,Hur, Jaehyun Pergamon Press 2016 Electrochimica Acta Vol. No.

<P><B>Abstract</B></P> <P>We present a facile approach to making Al-Sb, carbon-modified (Al-Sb-C) nanocomposites for use as new anode materials in lithium-ion batteries (LIB). Alloying is achieved by one step synthesis using high energy mechanical milling (HEMM), producing nanometer-sized alloy particles of Sb-Al<I> <SUB>x</SUB> </I>C<I> <SUB>y</SUB> </I>-C. Based on electrochemical analyses, we determined that Sb acts as an active material, and both Al and carbon create a hybrid buffering matrix that mitigates the volume expansion of the active material during lithiation/delithiation to a greater degree than that by a pure metallic matrix (AlSb). In addition, we optimized the stoichiometric ratio of Al and Sb with regard to specific capacity and cycling performance. Of the ratios tested, a 1:1 molar ratio of Al and Sb exhibited the best cycling performance (302.5mAhg<SUP>−1</SUP> after 200 charge/discharge cycles). Although our Al-Sb-C composite had low initial coulombic efficiency (∼59%), recovery to∼97% occurred within three cycles, indicating that initial side reactions are quickly reduced over the course of cycling. AlSb-C anodes also showed good rate capability and volumetric capacity. Overall, the new AlSb-C composite is a promising candidate for use as negative electrodes in lithium-ion batteries, providing an alternative to commercially available graphite electrodes.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We fabricated Sb-Al<SUB>x</SUB>C<SUB>y</SUB>-C nanocomposite alloy anodes by high-energy mechanical milling for use in lithium-ion batteries. </LI> <LI> The electrochemical performances, morphologies, and crystallographic features of AlSb and AlSbC with three different mixing ratios of Al and Sb were investigated. </LI> <LI> We found that AlSb(1:1)-C showed the best electrochemical performances in terms of specific capacity, cyclic performances, and rate capabilities. </LI> <LI> The mechanism of formation of AlSbC was examined by using XRD, TEM, and DCP data. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>We fabricated the high performances of Sb-Al<SUB>x</SUB>C<SUB>y</SUB>-C nanocomposite alloy anodes using high-energy mechanical milling for use in lithium-ion batteries.</P> <P>[DISPLAY OMISSION]</P>

Penalized PET Reconstruction Using Deep Learning Prior and Local Linear Fitting

Kim, Kyungsang,Wu, Dufan,Gong, Kuang,Dutta, Joyita,Kim, Jong Hoon,Son, Young Don,Kim, Hang Keun,El Fakhri, Georges,Li, Quanzheng IEEE 2018 IEEE transactions on medical imaging Vol.37 No.6

<P>Motivated by the great potential of deep learning in medical imaging, we propose an iterative positron emission tomography reconstruction framework using a deep learning-based prior. We utilized the denoising convolutional neural network (DnCNN) method and trained the network using full-dose images as the ground truth and low dose images reconstructed from downsampled data by Poisson thinning as input. Since most published deep networks are trained at a predetermined noise level, the noise level disparity of training and testing data is a major problem for their applicability as a generalized prior. In particular, the noise level significantly changes in each iteration, which can potentially degrade the overall performance of iterative reconstruction. Due to insufficient existing studies, we conducted simulations and evaluated the degradation of performance at various noise conditions. Our findings indicated that DnCNN produces additional bias induced by the disparity of noise levels. To address this issue, we propose a local linear fitting function incorporated with the DnCNN prior to improve the image quality by preventing unwanted bias. We demonstrate that the resultant method is robust against noise level disparities despite the network being trained at a predetermined noise level. By means of bias and standard deviation studies via both simulations and clinical experiments, we show that the proposed method outperforms conventional methods based on total variation and non-local means penalties. We thereby confirm that the proposed method improves the reconstruction result both quantitatively and qualitatively.</P>

Impacts of Soil Organic Matter on Microbial Community of Paddy Soils in Gyeongnam Province

Son, Daniel,Sonn, Yeon-Kyu,Weon, Hang-Yeon,Heo, Jae-Young,Kim, Dae-Ho,Choi, Yong-Jo,Lee, Sang-Dae,Ok, Yong Sik,Lee, Young Han 한국토양비료학회 2016 한국토양비료학회지 Vol.49 No.6

Agricultural management of paddy soil depends on the effects of soil microbial activities. The present study evaluated the soil microbial community of 25 paddy soils in Gyeongnam Province by fatty acid methyl ester (FAME). The average of microbial communities in paddy soils were 32.2% of total bacteria, 16.7% of Gram-negative bacteria, 12.9% of Gram-positive bacteria, 2.0% of actinomycetes, 14.9% of fungi, and 1.3% of arbuscular mycorrhizal fungi. The communities of total bacteria (34.9%) and Gram-negative bacteria (19.4%) in soils with $30{\sim}35g\;kg^{-1}$ of organic matter were significantly larger than those in soils with other organic matter levels. However, soils with $20{\sim}30g\;kg^{-1}$ of organic matter had significantly low ratio of cy17:0 to $16:1{\omega}7c$ and cy19:0 to $18:1{\omega}7c$ as compared with soils with $30{\sim}35g\;kg^{-1}$ of organic matter, indicating microbial stress decreased (p < 0.05). In principal component analyses of soil microbial communities, Gram-negative bacteria should be considered as a potential responsible factor for the obvious microbial community differentiation that was observed between the two different organic matter levels in paddy fields. Thus, soils containing $20{\sim}30g\;kg^{-1}$ of organic matter were responsible for strong effect on microbial biomass and stress in paddy fields.

Ozone-Generation Panel with an Atmospheric Dielectric Barrier Discharge

Kim Sang-Jin,Kim Sichan,Son Byung-Koo,Lee Kyu-Hang,Park Bong-Joo,Cho Guangsup 한국물리학회 2020 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.77 No.7

For small-scale discharge panels of volume-dielectric barrier discharge (V-DBD) and surface-DBD (S-DBD) with an Al2O3-ceramic dielectric layer and a sinusoidal alternating current (AC)-voltage at a frequency of 55 kHz, the plasma and the ozone densities in the discharge area are estimated by analyzing the I-V (current and voltage) characteristics and ozone measuring the concentration in a liter-scale container. With a plasma current in the range of 10-20 mA, the plasma density is np ~ (1018-1019) m-3 for the V-DBD and np ~ (1017-1018) m-3 for the S-DBD, irrespective of environmental temperature. However, the ozone density generated on DBD is strongly affected by the electrode temperature and is reduced as the environmental temperature is increased. At an environmental temperature as low as 10 °C, the ozone density generated on the V-DBD is as low as n(O3) ~ (1017-1018) m-3 with a high electrode temperature of more than 100 °C; on the other hand, the ozone density on the S-DBD is n(O3) ~ (1019-1020) m-3 with a low electrode temperature of ~30 °C, which is higher by an order of 102 than the plasma density on the S-DBD plasma panel.

In vivo metabotropic glutamate receptor 5 availability-associated functional connectivity alterations in drug-naïve young adults with major depression

Kim, Jong-Hoon,Joo, Yo-Han,Son, Young-Don,Kim, Jeong-Hee,Kim, Yun-Kwan,Kim, Hang-Keun,Lee, Sang-Yoon,Ido, Tatsuo Elsevier 2019 European neuropsychopharmacology Vol.29 No.2

<P><B>Abstract</B></P> <P>There has been increasing interest in glutamatergic neurotransmission as a putative underlying mechanism of depressive disorders. We performed [<SUP>11</SUP>C]ABP688 positron emission tomography (PET) and resting-state functional magnetic resonance imaging (rs-fMRI) in drug-naïve young adult patients with major depression to examine alterations in metabotropic glutamate receptor-5 (mGluR5) availability, and to investigate their functional significance relating to neural systems-level changes in major depression. Sixteen psychotropic drug-naïve patients with major depression without comorbidity (median age: 22.8 years) and fifteen matched healthy controls underwent [<SUP>11</SUP>C]ABP688 PET imaging and 3-T MRI. For mGluR5 availability, we quantified [<SUP>11</SUP>C]ABP688 binding potential (BP<SUB>ND</SUB>) using the simplified reference tissue model. Seed-based functional connectivity analysis was performed using rs-fMRI data with regions derived from quantitative [<SUP>11</SUP>C]ABP688 PET analysis as seeds. In region-of-interest (ROI)-based and voxel-based analyses, the [<SUP>11</SUP>C]ABP688 BP<SUB>ND</SUB> was significantly lower in patients than in controls in the prefrontal cortex ROI and in voxel clusters within the prefrontal, temporal, and parietal cortices, and supramarginal gyrus. The [<SUP>11</SUP>C]ABP688 BP<SUB>ND</SUB> seed-based functional connectivity analysis showed significantly less negative connectivity from the inferior parietal cortex seed to the fusiform gyrus and inferior occipital cortex in patients than in controls. The correlation patterns between [<SUP>11</SUP>C]ABP688 BP<SUB>ND</SUB> and functional connectivity strength (β) for the superior prefrontal cortex seed were opposite in the depression and control groups. In conclusion, using a novel approach combining [<SUP>11</SUP>C]ABP688 PET and rs-fMRI analyses, our study provides a first evidence of lower mGluR5 availability and related functional connectivity alterations in drug-naïve young adults with major depression without comorbidity.</P>

Effects of Fucoidan on NO Production and Phagocytosis of Macrophages and the Proliferation of Neuron Cells

Hang, Do,Choi, Hye-Sook,Kang, Se-Chan,Kim, Kyung-Ran,Sohn, Eun-Soo,Kim, Mi-Hyun,Pyo, Suhkneung,Son, Eun-Wha The Korean Society of Food Science and Nutrition 2005 Preventive Nutrition and Food Science Vol.10 No.4

Fucoidans, high-molecular-weight sulfated polysaccharides extracted from brown seaweeds, have various biological activities. Here we examined whether fucoidan could ncrease the immunomodulation and proliferation capacity of cells in vitro. When peritoneal macrophages were treated with various concentrations of fucoidan $(1\~100{\mu}g/mL)$ for 24 hours, NO production was significantly increased. In addition, exposure of macrophages to $10{\mu}g/mL$ of fucoidan induced a phagocytic activity. Treatment of neuroblastoma cells (SK-N-SH) with fucoidan enhanced cell proliferation and NO production in a concentration-dependent manner. These results indicate that fucoidan has both immunomodulatory and cell proliferative properties, and may thus be a candidate for development as an immunomodulating agent.

Review on the Method for Reduction of Radiation Dose by Radioactive Carbon in the Gaseous Effluent of NPPs

Hang-Rae Cho,Seok-Ju Hwang,Si-Young Kim,Hyo-Jin Park,Jung-Kwon Son 한국방사성폐기물학회 2024 한국방사성폐기물학회 학술논문요약집 Vol.22 No.1