3D flexible Si based-composite (Si@Si₃N₄)/CNF electrode with enhanced cyclability and high rate capability for lithium-ion batteries

Kim, Si-Jin,Kim, Min-Cheol,Han, Sang-Beom,Lee, Gyu-Ho,Choe, Hui-Seon,Kwak, Da-Hee,Choi, Sun-Yong,Son, Byung-Goo,Shin, Myoung-Sun,Park, Kyung-Won Elsevier 2016 Nano energy Vol.27 No.-

<P><B>Abstract</B></P> <P>Despite extremely high capacity of Si-based anodes in lithium-ion batteries (LIB), Si-based materials have shown a structural collapse caused by a volumetric expansion/contraction during the cycling process. The conventional electrode structure, which consists of active materials, a current collector, a conducting agent, and a binder, actually showed a low loading of active material due to the other heavy components. In this study, we prepared a 3D flexible Si-composite electrode consisting of core (Si)-shell (Si<SUB>3</SUB>N<SUB>4</SUB>) NPs (Si@Si<SUB>3</SUB>N<SUB>4</SUB>) and carbon nanofibers (denoted as Si-composite/CNF). The Si-composite/CNF was directly utilized as an anode in the absence of the other components was electrochemically evaluated using a coin-type cell. The Si-composite/CNF showed a high capacity of 665mAhg<SUP>−1</SUP> at a fairly high current density of 10Ag<SUP>−1</SUP> and an extremely low capacity loss for 2000 cycles.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We prepared Si-composite/CNF exhibits a 3D flexible Si-composite electrode. </LI> <LI> The electrode consists of core (Si)-shell (Si<SUB>3</SUB>N<SUB>4</SUB>) NPs (Si@Si<SUB>3</SUB>N<SUB>4</SUB>) and carbon nanofibers. </LI> <LI> The Si-composite/CNF was directly utilized as an anode. </LI> <LI> Si-composite /CNF exhibited high specific capacity and improved high rate cycling performance. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Controlled infiltration profile of SiC coating layer on graphite by Si vapor deposition reaction

Kuk-Jin Hwang,Si-Young Bae,Kyoung-Ho Kim,Yoon-Cheol Lee,Jung-Tae Hwang,Heesoo Lee,Seong Min Jeong,Myung-Hyun Lee 한양대학교 세라믹연구소 2019 Journal of Ceramic Processing Research Vol.20 No.2

SiC-coated graphite was successfully fabricated at different temperatures (1300-1600 oC) through a silicon vapor depositionreaction (Si-VDR) process. Si powder was used for the Si source of the SiC coating layers. When Si powder was evaporatedat high temperature near the melting point of bulk Si, Si gases are moved and changed into Si liquid at the surface of thegraphite. The high-temperature process facilitated the formation of SiC coating layers on the graphite. The microstructural,mechanical, and thermal oxidation properties of the coated graphite were investigated.

급성신부전을 동반한 알콜성 횡문근융해증 2례

김영민,오동렬,이원재,김형국,황두영,이환,최경호,정시경,김세경,김영옥 大韓應急醫學會 1998 대한응급의학회지 Vol.9 No.4

Rhabdomyolysis is a biochemical and clinical syndrome caused by lysis of skeletal muscle cell and release of muscle cell contents into the circulation. In addition to traumatic cause, various nontraumatic causes have been reported. Rhabdomyolysis has frequently been associated with seamy aspects of life and society: alcoholic abuse, drug addiction, sadistic drill exercise, war events and attempted suicide. The abuse of alcohol causes many hazards in many organs. One of these is acute alcoholic myopathy that may present as a fulminent syndrome of muscle pain and tenderness associated with rhabdomyolysis and acute renal failure. Because the prognosis of adequately treated rhabdomyolysis is excellent, early recognition and prompt management are essential in emergency situation. We experienced two typical cases of alcohol-induced rhabdomyolysis with acute renal failure and report these cases with literature review.

중증 미만성 뇌축색손상 환자의 MRI소견 및 임상적 고찰

김한겸,김성호,송시헌,김관태,김윤 대한신경외과학회 1995 Journal of Korean neurosurgical society Vol.24 No.1

The distribution and extent of traumatic lesions were evaluated with MRI in 31 patients with diffuse axonal injuries(DAI). Authors also analyzed patients with diffuse axonal injury, clinically. The patients with DAI showed statistically significant lower incidence of lucid interval, fracture of the skull and intracranial hematoma. Combined injuries, intracrnial hematomas and distribution of lisions were porved to be poor prognostic factors of DAI. Diffuse axonal injury is most commonly involved in the white matter of the frontal and temporal loves and the splenium of the corpus callosum. Patients with lisions in brainstem and cerebellum revealed worst prognoses. In our studies, the sensitivities of the imaging techniques for diffuse axonal injures were 7.3% with CT scan, 75.6% with T1WI, and with 97.6% in T2WI of MRI, respectively. The authors concluded that MRI has clear advantages over CT in evaluating diffuse axonal injuries.

백서 척수후근절로부터 슈반세포의 효과적인 체외 배양법

김성민,이종호,김남열,안강민,최원재,최시호,차미주,이주영,황순정,장정원,명훈,최진영,서병무,정필훈,김명진 大韓顎顔面成形再建外科學會 2003 Maxillofacial Plastic Reconstructive Surgery Vol.25 No.4

Schwann cells(SCs), an important component of the peripheral nervous system, intract with nerous to mutually support growth and replication for the peripheral nerve regentation. Recently, ading SCs to the lumen of guidance channel is widely tried to improve regeneration or to make regeneration possible over otherwise irreparable gaps. however, it is not easy to isolate and multiplicate SCs as much as enough to help the axonal regeneration. For the allogeneic SCs source for tubular nerve guidance, we developed a little bit improved technique of harvesting and multiplicating SCs. by culturing dispersed dorsal root ganglia in specially designed medium with growth factors and serial processing, we repeatedlly generate relatively homogenous SC cultures. Our technique was compared with other methods of literature using immunostaining methods such as GFAP, S100, BDNF and the total SC count assessment at different time interval after primary culture.

Improved Adhesion of Metal Electrode Layer on Si₃N₄ Substrate through an All-Wet Process

Kim, Danbi,Eom, Nu Si A,Kim, Jiwon,Lee, Kyu Hyoung,Park, Sung Heum,Lee, Ju Ho,Chao, Yong-Ho,Lim, Jae-Hong Electrochemical Society 2019 ECS journal of solid state science and technology Vol.8 No.2

<P>Electroless deposition requires preliminary surface treatment to effectively adsorb a metal electrode layer onto a ceramic substrate. Herein, a simple surface treatment using an all-wet process was performed to achieve adhesion stability between a Si<SUB>3</SUB>N<SUB>4</SUB> substrate and Ni film. The method involved deposition of an interfacial Pd-TiO<SUB>2</SUB> buffer between the two layers. Surface pretreatment via silanization was initially performed to improve surface wettability, thereby enhancing uniform deposition of Pd-TiO<SUB>2</SUB>. Subsequently, a thin Ni layer was directly deposited onto the Pd-TiO<SUB>2</SUB> layer without necessitating sensitization or activation. The synthesized Ni/Pd-TiO<SUB>2</SUB>/Si<SUB>3</SUB>N<SUB>4</SUB> heat sink exhibited excellent adhesion property in the cross-hatch, scratch, and thermal shock tests. The mechanism of adhesion enhancement involved chemical bonding of Pd-TiO<SUB>2</SUB> with the self-assembled monolayer on the substrate and reduced internal stress due to removal of residual hydrogen between the layers of the heat sink. Thus, the fabricated heat sink has a promising application in electronic devices operated at high temperatures.</P>

서울의 Penicillinase Producing Neisseria Gonorrhoeae 발생빈도(1994)

김재홍,안진균,정성재,김영태,김중환,김시영,이석종,이홍렬,서호석,김경훈,권혁진,정우권,고우석,이용석,안필수,오준규,오용섭 대한화학요법학회 1996 대한화학요법학회지 Vol.14 No.1

Background : In recent years gonorrhoea has been panendemic and remains one of the most common Sexually Transmitted Diseases in the world, especially in developing countries. Objective & Method : For the detection of a more effective therapeutic regimen and assessing the prevalence of Penicillinase Producing Neisseria Gonorrhoeae(PPNG), Ive have been trying to study the patients who have visited the VD Clinic of Choong-Ku Public Health Center in Seoul since 1980 by means of the chromogenic cephalosporin method. Results : In 1994, 168 strains of N. gonorrhoeae were isolated, among which 109 (64,9% ) were PPNG. Conclustion : Our results suggests that the prevalence of PPNG in Seoul is still increasing.

Fluoxetine and Sertraline Attenuate Postischemic Brain Injury in Mice

Tae Kyeong Shin,Mi Sun Kang,Ho Youn Lee,Moo Sang Seo,Si Geun Kim,Chi Dae Kim,Won Suk Lee 대한생리학회-대한약리학회 2009 The Korean Journal of Physiology & Pharmacology Vol.13 No.3

This study aimed to investigate whether selective serotonin reuptake inhibitors (SSRIs) attenuate brain injury and facilitate recovery following photothrombotic cortical ischemia in mice. Male ICR mice were anesthetized and systemically administered Rose Bengal. Permanent focal ischemia was induced in the medial frontal and somatosensory cortices by irradiating the skull with cold light laser. The animals were treated with fluoxetine or sertraline once a day for 14 d starting 1 h after ischemic insult. Treatment with fluoxetine and sertraline significantly reduced the infarct size. The Evans blue extravasation indices of the fluoxetine- and sertraline-treated groups were significantly lower than that of the vehicle group. Treatment with fluoxetine and sertraline shifted the lower limit of the mean arterial blood pressure for cerebral blood flow autoregulation toward normal, and significantly increased the expression of heme oxygenase-1 (HO-1) and hypoxia-inducible factor-1Ձ (HIF-1Ձ) proteins in the ischemic region. These results suggest that SSRIs, such as fluoxetine and sertraline, facilitate recovery following photothrombotic cortical ischemia via enhancement of HO-1 and HIF-1Ձ proteins expression, thereby providing a benefit in therapy of cerebral ischemia.

Fluoxetine and Sertraline Attenuate Postischemic Brain Injury in Mice

Shin, Tae-Kyeong,Kang, Mi-Sun,Lee, Ho-Youn,Seo, Moo-Sang,Kim, Si-Geun,Kim, Chi-Dae,Lee, Won-Suk The Korean Society of Pharmacology 2009 The Korean Journal of Physiology & Pharmacology Vol.13 No.3

This study aimed to investigate whether selective serotonin reuptake inhibitors (SSRIs) attenuate brain injury and facilitate recovery following photothrombotic cortical ischemia in mice. Male ICR mice were anesthetized and systemically administered Rose Bengal. Permanent focal ischemia was induced in the medial frontal and somatosensory cortices by irradiating the skull with cold light laser. The animals were treated with fluoxetine or sertraline once a day for 14 d starting 1 h after ischemic insult. Treatment with fluoxetine and sertraline significantly reduced the infarct size. The Evans blue extravasation indices of the fluoxetine- and sertraline-treated groups were significantly lower than that of the vehicle group. Treatment with fluoxetine and sertraline shifted the lower limit of the mean arterial blood pressure for cerebral blood flow autoregulation toward normal, and significantly increased the expression of heme oxygenase-1 (HO-1) and hypoxia-inducible factor-1 ${\alpha}$ (HIF-1 ${\alpha}$) proteins in the ischemic region. These results suggest that SSRIs, such as fluoxetine and sertraline, facilitate recovery following photothrombotic cortical ischemia via enhancement of HO-1 and HIF-1 ${\alpha}$ proteins expression, thereby providing a benefit in therapy of cerebral ischemia.

광양만에서 춘계와 하계 영양염류 첨가가 식물플랑크톤군집의 성장에 미치는 영향

배시우,김동선,최현우,김영옥,문창호,백승호,Bae, Si Woo,Kim, Dongseon,choi, Hyun-Woo,Kim, Young Ok,Moon, Chang Ho,Baek, Seung Ho 한국해양학회 2014 바다 Vol.19 No.1

춘계와 하계 광양만에서 식물플랑크톤 군집구조와 그들의 성장에 영향을 미치는 영양염제한 특성을 파악하기 위해서 만내외측의 20개 정점에서 생물학적 요인과 무생물학적 요인을 조사했다. 또한 식물플랑크톤 군집에 대한 영양염 첨가 효과를 알아보기 위해서 실험실에서 현장 20개 정점의 표층수를 이용하여 생물검정실험을 수행하였다. 전체 식물플랑크톤 군집의 90%이상을 규조류가 차지하였다. 이들 규조류중 Eucampia zodiacus와 Skeletonema costatum-like 종이 춘계와 하계에 각각 우점하였다. E. zodiacus와 S. costatum-like 규조류의 개체군 밀도가 춘계와 하계에 높은 밀도를 유지하게 된 이유를 간단히 설명하면, E. zodiacus 의 성장은 춘계 투명도가 높게 나타나 유광층내 광량의 증가가 원인으로 생각된다. 즉 유광층내 광량의 증가는 E. zodiacus의 개체수를 폭발적으로 증가시킬 수 있는 방아쇠 역할을 한 것으로 판단된다. 하계에 S. costatum-like이 전해역에서 우점한 이유는, 섬진강 담수 유입에 의한 낮은 염분과 함께 공급된 다량의 영양염은 그들 생물의 증식에 중요한 bottom-up 효과를 보였다고 판단된다. 실험실의 생물검정실험에서는 비록 내만(정점 8)과 외해(정점 20)에서 식물플랑크톤 군집의 최대 성장율은 유사하였지만, 인산염에 대한 반포화계수($K_s$)는 내만정점보다 약간 낮았다. 상대적으로 낮은 영양염농도에 적응한 세포는 낮은 인산염농도에서 충분히 성장할 수 있고, 다른 미세조류에 비하여 낮은 영양염농도의 조건에서 경쟁의 우위를 차지 할 것이다. 특히, 하계의 N영양염 첨가군의 효율은 대조군과 P영양염 첨가군에 비해서 높았다. 이는 광양만에서 하계에 N영양염의 공급이 섬진강을 통하여 계속적으로 유입되지만, 빠른 식물플랑크톤의 증식으로 인하여 N영양염 제한이 일어날 수 있다는 것을 시사할 수 있다. 반면, 규산염은 식물플랑크톤의 성장에 영향을 미치는 제한인자로 나타나지 않았고, 규조류의 분해로 인하여 Si의 재순환과 담수로부터 공급된 높은 규산염농도는 광양만에서 규조류 생태계를 유지할수 있는 유리한 조건이라 생각된다. In order to estimate the effect of nutrients addition for phytoplankton growth and community compositons in spring and summer season, we investigated the abiotic and biotic factors of surface and bottom waters at 20 stations of inner and offshore areas in Gwangyang Bay, Korea. Nutrient additional experiments were also conducted to identify any additional nutrient effects on phytoplankton assemblage using the surface water for the assay. Bacillariophyceae occupied more than 90% of total phytoplankton assembleges. Of these, diatom Eucampia zodiacus and Skeletonema costatum-like species was mainly dominated in spring and summer, respectively. Here, we can offer the season why the two diatom population densities were maintained at high levels in both seasons. First, light transparency of spring season in the euphotic zone was greatly improved in the bay. This improvement is one of important factor as tigger of increase in E. zodiacus population. Second, low salinity and high nutrient sources supplied by Seomjin River discharge are a main cue for strong bottom-up effects on S. costatum-like species during the summer rainy season. Based on the algal bio-assays, although maximum growth rate of phytoplankton communities at inner bay (St.8) were similar to those of outer bay (St.20), half-saturation constant ($K_s$) for phosphate at outer bay was slightly lower than those of inner bay. This implied that adapted cells in low nutrient condition of outer bay may have enough grown even the low phosphate and they also have a competitive advantage against other algal species under low nutrient condition. In particular, efficiency of N (+) addition in summer season was higher compared to control and P added experiments. In the bay, silicon was not a major limiting factor for phytoplankton growth, whereas nitrogen (N) was considered as a limiting factor during spring and summer. Therefore, a sufficient silicate supply form water mixing Si recycled from diatom decomposition and river water is favorable form maintaining diatom ecosystems in Gwangyang Bay.