Fabrication of insulated metal substrates with organic ceramic composite films for high thermal conductivity

Kim, Seonghyeop,Kim, Jooyoung,Hyeok Kim, Jin Elsevier 2017 Ceramics international Vol.43 No.11

<P><B>Abstract</B></P> <P>Insulated metal substrates (IMSs) were fabricated and characterized using an organic ceramic composite as a coating mixture. Organic‐inorganic sol solutions were prepared by a sol‐gel process using TEOS (tetraethylorthosilicate), MTMS (methyltrimethoxysilane) and PhTMS (phenyltrimethoxysilane). Ceramic fillers were composed of aluminum oxide (1 and 4µm) and silicon nitride. The optimal ratio of ceramic filler in the coating mixture was found to be 70wt%. A thermal conductivity of 3.16W/mK and a breakdown voltage of 4kV with a leakage current of 0.17mA/cm<SUP>2</SUP> were obtained for the 122µm-thick film. A well-networked microstructure between the sol resin and filler in the organic ceramic composite films enhanced the properties of the IMS, such as thermal conductivity and electric insulation.</P>

Ferroelectric (Ba,Sr)TiO3 thin films on Pt/Ti/SiO2/Si substrates by the sol-gel process and evaluation of the intrinsic dead layers

Jooyoung Kim,Gwangseo Park,Jaemoon Park,Kwangwoo Nam 한국물리학회 2005 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.47 No.2

Ferroelectric (Ba,Sr)TiO3 (BST) films with a Ba : Sr ratio of 50 : 50 were deposited on Pt/Ti/SiO2/Si substrates by the sol-gel process. The films were spin-coated at 2000 rpm for 30 sec and then pyrolysed for 5 min at a temperature of 350 C. This coating procedure was repeated 3, 4, 5 and 6 times to obtain BST films with different thicknesses. After coating the films with the desired repetition times, the films were finally annealed in a conventional furnace at temperatures ranging from 600 C to 800 C with a 50 C interval in between. The films obtained with an annealing procedure of 750 C were polycrystalline with the presence of an impurity BaCO3 phase. The capacitance and leakage current were measured and used to extract information on the metal-BST interface. With the series capacitance model and modified Schottky emission equation, we will report on the evaluation of dead layer thicknesses in BST films sandwiched between noble metal electrodes.kwhere

Changes in Direct Healthcare Costs before and after the Diagnosis of Inflammatory Bowel Disease: A Nationwide Population-Based Study

Jooyoung Lee,Jong Pil Im,Kyungdo Han,Jihye Kim,Hyun Jung Lee,Jaeyoung Chun,Joo Sung Kim 거트앤리버 소화기연관학회협의회 2020 Gut and Liver Vol.14 No.1

Background/Aims: We aimed to investigate the differences in direct healthcare costs between patients with and without inflammatory bowel disease (IBD) and changes in direct healthcare costs before and after IBD diagnosis. Methods: This population-based study identified 34,167 patients with IBD (11,014 patients with Crohn’s disease and 23,153 patients with ulcerative colitis) and 102,501 age-and sex-matched subjects without IBD (the control group) from the National Health Insurance database using the International Classification of Disease, 10th revision codes and the rare intractable disease registration program codes. The mean healthcare costs per patient were analyzed for 3 years before and after IBD diagnosis, with follow-up data available until 2015. Results: Total direct healthcare costs increased and peaked at $2,396 during the first year after IBD diagnosis, but subsequently dropped sharply to $1,478 during the second year after diagnosis. Total healthcare costs were higher for the IBD patients than for the control group, even in the third year before the diagnosis ($497 vs $402, p<0.001). The costs for biologics for the treatment of IBD increased steeply over time, rising from $720.8 in the first year after diagnosis to $1,249.6 in the third year after diagnosis (p<0.001). Conclusions: IBD patients incurred the highest direct healthcare costs during the first year after diagnosis. IBD patients had higher costs than the control group even before diagnosis. The cost of biologics increased steeply over time, and it can be assumed that biologics could be the main driver of costs during the early period after IBD diagnosis.

Longer application of kinesio taping would be beneficial for exercise-induced muscle damage

Jooyoung Kim,Seunghwan Kim,Joohyung Lee 한국운동재활학회 2016 JER Vol.12 No.5

Matrix metalloproteinase and tissue inhibitor of metalloproteinase responses to muscle damage after eccentric exercise

Jooyoung Kim,Joohyung Lee 한국운동재활학회 2016 JER Vol.12 No.4

Synthesis of stable monoporphyrinate lanthanide(<small>III</small>) complexes without ancillary ligands

Kim, Eui-Jong,Kim, Pyosang,Lee, Chi-Hwa,Sung, Jooyoung,Yoon, Hongsik,Kim, Dongho,Jang, Woo-Dong The Royal Society of Chemistry 2012 Chemical communications Vol.48 No.45

<P>A new type of porphyrin ligand bearing four triazole groups at the <I>ortho</I>-positions of phenyl rings in tetraphenylporphyrin was synthesized for the formation of monoporphyrinate lanthanide complexes without ancillary ligands.</P> <P>Graphic Abstract</P><P>A new type of porphyrin ligand bearing four triazole groups at the <I>ortho</I>-positions of phenyl rings in tetraphenylporphyrin was synthesized for the formation of monoporphyrinate lanthanide complexes without ancillary ligands. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c2cc31015e'> </P>

The Influence of Life Stress and Sleep Disturbance on White Matter Integrity

Kim Minjeong,Lee Jiye,Kim Nambeom,Hwang Yunjee,Lee Kyung Hwa,Lee Jooyoung,Lee Yu Jin,Kim Seog Ju 대한신경정신의학회 2023 PSYCHIATRY INVESTIGATION Vol.20 No.5

Objective This study investigated whether sleep and stress mutually interact to induce changes in white matter integrity.Methods Diffusion tensor imaging (DTI) was conducted on 36 participants (male=22, female=14; mean age=38.33±12.78 years). Participants were divided into three groups depending on their sleep quality and stress levels: poor sleepers with stress, poor sleepers without stress, and good sleepers. Sleep quality and stress level were evaluated using the Pittsburgh Sleep Quality Index and the Life Experiences Survey, respectively. Fractional anisotropy (FA) values were calculated employing DTI tractography.Results After controlling for age and sex, poor sleepers with stress exhibited a lower FA of the left inferior cerebellar peduncle (ICP) than did poor sleepers without stress (t=2.81, p=0.02). Poor sleepers without stress showed a higher FA of the right middle longitudinal fasciculus (MdLF) than did good sleepers (t=3.35, p=0.006).Conclusion The current study reports the effects of sleep, stress, and their interaction on the white matter integrities of the ICP and MdLF. ICP change seems to be associated with sleep disturbances related to stress, while MdLF change would be associated with sleep disturbances unrelated to stress.

Electrochemical fabrication of Fe-based binary and ternary phosphide cathodes for proton exchange membrane water electrolyzer

Kim, Junhyeong,Kim, Hyunki,Kim, Jooyoung,Kim, Jung Hwan,Ahn, Sang Hyun Elsevier 2019 JOURNAL OF ALLOYS AND COMPOUNDS Vol.807 No.-

<P><B>Abstract</B></P> <P>The development of high-performance gas diffusion electrodes is essential for the fabrication of efficient proton exchange membrane water electrolyzers (PEMWEs) and thus for clean hydrogen production. Herein, we electrodeposited Fe-based binary and ternary phosphides on porous carbon paper (CP) as a substrate and demonstrated that, under optimized deposition conditions (i.e. when the P content was maximum), amorphous FeCoP showed the highest intrinsic activity for hydrogen evolution in an acidic medium. This behavior was ascribed to appropriate electronic structure modification and the alloying effect. Further enhancement of hydrogen evolution performance was achieved by increasing the electrochemical surface area of FeCoP by using a porous Cu foam (CF) support. In a half-cell test, the FeCoP/CF/CP electrode featured an acceptably stable cathodic current of −10 mA/cm<SUP>2</SUP> at an overpotential of −125 mV. A PEMWE single cell with an FeCoP/CF/CP cathode exhibited a current density of 0.95 A/cm<SUP>2</SUP> at a cell voltage of 2.0 V, which is superior to or comparable with previously reported values. Thus, the developed electrode might be a promising alternative to Pt-based cathodes in practical PEMWE applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Fe-based transition metal phosphides were electrodeposited on porous carbon paper. </LI> <LI> FeCoP/carbon paper (CP) showed the highest HER intrinsic activity. </LI> <LI> The electrochemical surface area of FeCoP was increased by using a Cu foam support. </LI> <LI> PEMWE with a FeCoP/CF/CP cathode featured a current density of 0.95 A/cm<SUP>2</SUP> at 2.0 V. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Fingerprint DB Generating System Exploiting PDR based Dynamic Collection for Indoor Localization of Smart-phone Users

Jooyoung Kim,MyungIn Ji,Youngsu Cho,Yangkoo Lee,Sangjoon Park 제어로봇시스템학회 2013 제어로봇시스템학회 국제학술대회 논문집 Vol.2013 No.10

The fingerprinting has been considered as a promising method for indoor localization due to the robustness from the multi-path than other methods exploiting wireless signals. However, the fingerprinting method has serious limitation which it requires too much time and cost to construct a DB (Data Base) before positioning. In conventional static collection based fingerprint DB generation system, it usually takes up to several minutes to obtain a radio pattern for a single reference point comprising very small part of whole service areas. To overcome the drawback, the fingerprint DB generation system based on the dynamic collection, which breaks the tradition of the radio pattern collection, is proposed. In contrast to the conventional collection method, a collector carrying a smart-phone moves pre-designated routes in service areas, and the position and the radio patterns are autonomously gathered by the collecting application in the smart-phone at every seconds. With the dynamically collected data, then, the fingerprint DB is finally generated by averaging method. From the experimental results, it is validated that the proposed collection method remarkably improves the efficiency of the collection. Also, the positioning using the generated DB shows reasonable accuracy, 2.62m, in an indoor office environment.

Delirium characteristics and outcomes in medical and surgical lnpatients: A subgroup analysis

Kim, Sungmin,Kim, Jae-Jin,Oh, Jooyoung,Park, Jaesub,Park, Jin Young Elsevier 2018 Journal of critical care Vol.43 No.-

<P><B>Abstract</B></P> <P><B>Purpose</B></P> <P>Persistent delirium can negatively affect patients, increase healthcare costs, and extend the length of hospital stays. This investigation was undertaken to explore associations between patient characteristics and delirium outcomes.</P> <P><B>Materials and methods</B></P> <P>Intensive care unit (ICU) and medical and surgical ward inpatients for whom psychiatric consultation was requested for delirium were included in this study. Delirium screening and ongoing assessments were conducted using the Confusion Assessment Method for ICU patients.</P> <P><B>Results</B></P> <P>Postoperative delirium developing as a secondary complication following surgery was found to be of significantly longer duration and associated with greater length of hospitalization compared with postoperative delirium attributable to surgery and delirium in medical patients. Medical patients with delirium had lower delirium recovery rates at discharge compared with surgical patients.</P> <P><B>Conclusions</B></P> <P>The findings that patient type and timing of postoperative delirium are associated with differential delirium outcomes suggest that targeted screening and intervention approaches may be needed. Medical patients were more likely to be discharged before recovery from delirium compared with surgical patients. Differences in underlying chronic medical conditions may account for the observed differences in discharge condition between medical and surgical patients with delirium.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Delirium is a commonly observed condition following surgical intervention. </LI> <LI> Previous research on postoperative delirium focused on vulnerable populations. </LI> <LI> We explored delirium progression between medical and surgical patient populations. </LI> <LI> Delirium duration, delirium recovery, and length of hospital stay were measured. </LI> </UL> </P>