Optimum Morphology of Mixed-Olivine Mesocrystals for a Li-Ion Battery

Park, Kimin,Kim, Jaewon,Wi, Sungun,Lee, Sangheon,Hwang, Taehyun,Kim, Jaewook,Kang, Joonhyeon,Choi, Joon-Phil,Nam, Seunghoon,Park, Byungwoo American Chemical Society 2018 Inorganic Chemistry Vol.57 No.10

<P>In this present work, we report on the synthesis of micron-sized LiMn<SUB>0.8</SUB>Fe<SUB>0.2</SUB>PO<SUB>4</SUB> (LMFP) mesocrystals via a solvothermal method with varying pH and precursor ratios. The morphologies of resultant LMFP secondary particles are classified into two major classes, flakes and ellipsoids, both of which are featured by the mesocrystalline aggregates where the primary particles constituting LMFP secondary particles are crystallographically aligned. Assessment of the battery performance reveals that the flake-shaped LMFP mesocrystals exhibit a specific capacity and rate capability superior to those of other mesocrystals. The origin of the enhanced electrochemical performance is investigated in terms of primary particle size, pore structure, antisite-defect concentration, and secondary particle shape. It is shown that the shape of the secondary particle has just as much of a significant effect on the battery performance as the crystallite size and antisite defects do. We believe that this work provides a rule of design for electrochemically favorable meso/nanostructures, which is of great potential for improving battery performance by tuning the morphology of particles on multilength scales.</P><P>Micron-sized LiMn<SUB>0.8</SUB>Fe<SUB>0.2</SUB>PO<SUB>4</SUB> mesocrystals having various morphologies were facilely synthesized via a solvothermal method. The origin of the different electrochemical performances of the mesocrystals was investigated in terms of primary particle size, pore structure, antisite-defect concentration, and secondary particle shape. We believe that this work can provide a rule of design for the electrochemically favorable meso/nanostructures, which is of great potential for improving battery performance.</P> [FIG OMISSION]</BR>

Development of probabilistic primary water stress corrosion cracking initiation model for alloy 182 welds considering thermal aging and cold work effects

Park, Jae Phil,Yoo, Seung Chang,Kim, Ji Hyun,Bahn, Chi Bum Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.6

We experimentally investigated the effects of thermal aging and cold work on the microstructure, mechanical properties, and primary water stress corrosion cracking (PWSCC) initiation time for Alloy 182 welds. The effects of thermal aging and cold work on the PWSCC initiation time of Alloy 182 were modeled based on the plastic energy concept and the PWSCC initiation data of this study and previous reports by considering censored data. Based on the results, it is estimated that the PWSCC resistance of the Alloy 182 weld firstly increases and then decreases with thermal aging time when the applied stress is kept constant.

Correlation between Pneumonia Severity and Pulmonary Complications in Middle East Respiratory Syndrome

Park, Wan Beom,Jun, Kang Il,Kim, Gayeon,Choi, Jae-Phil,Rhee, Ji-Young,Cheon, Shinhyea,Lee, Chang Hyun,Park, Jun-Sun,Kim, Yeonjae,Joh, Joon-Sung,Chin, Bum Sik,Choe, Pyeong Gyun,Bang, Ji Hwan,Park, Sang KOREAN ACADEMY OF MEDICAL SCIENCE 2018 JOURNAL OF KOREAN MEDICAL SCIENCE Vol.33 No.24

<P>This nationwide, prospective cohort study evaluated pulmonary function and radiological sequelae according to infection severity in 73 survivors from the 2015 Middle East respiratory syndrome (MERS) outbreak in Korea. Patients with severe pneumonia in MERS-coronavirus infection had more impaired pulmonary function than those with no or mild pneumonia at the 1-year follow-up, which was compatible with the radiological sequelae. Severe pneumonia significantly impairs pulmonary function and makes long radiological sequelae in MERS.</P>

Performaance Analysis of Distributed Deadlock Detection and Resolution Algorithms based on a Hybrid Wait-for Graph and Probe Generation Scheme

Park,Young-Chul,Park,Yang-Soo,Cheung,Young-Phil 울산대학교 1993 공학연구논문집 Vol.24 No.1

본 논문은 분산 데이타베이스 시스템에서의 교착상태 검출 및 회복을 위한 연속 알고리즘을 제시한다. 이 알고리즘은 각 지역 사이트에 확장된 트랜잭션 대기 그래프를 유지하며 각 사이트간 메세지 전달의 수효를 최소화하기 위해 우선순위에 기초한 프로브 생성 기법을 변형하여 사용한다. 확장된 트랜잭션 대기 그래프는 로크-대기 정보 뿐만 아니라 트랜잭션 에이전트들간의 메세지-대기 정보, 수신한 프로브들, 그리고 트랜잭션 사이의 이행-대기 관계들에 관한 정보도 포함한다. 전역 교착상태는 어떤 프로브나 이행-대기 관계가 그 프로브를 개시한 트랜잭션의 어떤 에이전트로 전파될 때마다 선언된다. 교착상태의 거짓선언 확률을 최소화하기 위하여 제시한 알고리즘에 대하여 두가지 확장을 가했다. 이들은 교착상태 선언시 이의 정당성을 검증하는 부가적인 절차를 추가한 것이다. 세가지 제안한 방법의 성능을 시뮬레이션을 통하여 비교분석 하였다. We present a continuous algorithm for deadlock detection and resolution in distributed database systems. our algorithm maintains at each local site an augmented transaction wait-for graph and used a modified priority-based probe generation scheme in order to minimize the number of intersite messages sent. The augmented transaction-wait for graph contains, in addition to lock-wait information, also information about message-wait relationships among the agents of a transaction, received probes and transitive wait-for relationships among transactions. Global deadlocks are declared whenerver a probe or transitive-wait relationship is propagated to an agent of the transaction that initiated the probe. In order to minimize the probability of false deadlocks, two extensions to the original algorithm are presented which make use of an additional validation procedure. We report on the results of simulation experiments that compare the performance of the three proposed schemes for deadlock detection and resolution.

HSP70 Is Involved in the Radioadaptive Response : Results from Mouse Splenocytes

Park, Kyoung-Phil,Cho, Chul-Koo,Seo, Jeong-Sun,Park, Woong-Yang,Lee, Su-Jae,Leea, Yun-Sil 대한방사선 방어학회 2002 방사선방어학회지 Vol.27 No.4

In continuation of our earlier study on the involvement of heat shock protein (HSP) 25 and HSP70 in the induction of adaptive response, we have now examined the involvement of these proteins in the induction of the adaptive response, using an animal model system. C57BL6 mice were irradiated with 5 cGy of gamma radiation 3 times for a week (total of 15cGy) and a high challenge dose (6Gy) was given on the day following the last low dose irradiation. Survival rate of the low dose pre-irradiated mice was increased to 30%. Moreover, high dose-mediated induction of apoptosis was also reduced by low dose pre-irradiation. To elucidate any link existing between HSP and induction of the adaptive response, reverse transcriptase (RT)-polymerase chain reaction (PCR) analysis was performed using splenocytes. High dose radiation up-regulated the expression of HSP25 and especially HSP70; while expression of other HSPs such as HSC70, HSP90, and a?-crystalline did not change. When splenocytes from HSP70 transgenic mice were pre-irradiated with a low dose of radiation, a reduction in cell death by high dose radiation was observed. These results, suggest that HSP70 is a key molecule in the induction of adaptive response.

Differential expression of two glutamate transporters, GLAST and GLT-1, in an experimental rat model of glaucoma.

Park, Chan Kee,Cha, Jiook,Park, Soo Chul,Lee, Phil Young,Kim, Jie Hyun,Kim, Hwa Sun,Kim, Shin Ae,Kim, In-Beom,Chun, Myung-Hoon Springer-Verlag 2009 Experimental brain research Vol.197 No.2

<P>Glutamate is the major excitatory neurotransmitter of the mammalian retina, and excessive glutamate has been implicated in the pathogenesis of glaucoma. It is well known that glutamate transport, mainly via GLAST and GLT-1, is cardinal mechanism for maintaining glutamate homeostasis in normal and pathological conditions, including ischemia in the brain. In an eVort to understand the role of glutamate and the glutamate regulation system of the retina in the pathogenesis of glaucoma, we examined changes in the expression of two glutamate transporters, GLAST and GLT-1, by Western blot analysis and immunocytochemistry in a rat glaucoma model. GLT-1 was expressed in cone photoreceptors and some cone bipolar cells and the levels of expression were signiWcantly increased in the cauterized eyes throughout the entire experimental period. In contrast, GLAST expression, which occurred in Muller cells, the main retinal glial cells, remained stable during the experimental period. These results suggest that GLT-1 may be a prerequisite for the maintenance of glutamate homeostasis in the retina undergoing glaucoma.</P>

Phylogenetic Study of Acetobacter sp. KM by 5S ribosomal RNA Sequencing

Park, Jong-Phil,Hwang, Chul-Kyu,Kim, Sung-Jun 조선대학교 부설 유전생물공학연구소 1994 유전생물공학연구지 Vol.4 No.-

초산 생성균인 Acetobacter sp. KM의 세포질 5S rRNA 염기 서열을 RNA의 직접화학분석법에 의하여 결정하고 그 결과를 기존에 보고된 11종의 Acetobacter속과 2종의 Gluconobacter속의 5S rRNA서열과 비교하였다. 본 균주의 5S rRNA는 일반적인 초산 생성균들과는 달리 121개의 염기구조를 가지고 있었으며 Acetobacter pasteurianus와 높은 상동성을 보여주었다. Kimura의 염기 치환 상수 Knuc값에 의하면 A. pasteurianus 가 본 균주와 가장 근연종임을 알 수 있었다. Urakami등이 5S rRNA 서열에 의해 초산 생성균을 non-methylotrophic, methylotrophic Acetobacter와 Gluconobacter등의 3 group으로 분류한 바, 본 균주는 특이하게도 methanol을 탄소원으로 이용하면서도 non-methylotrophic Acetobacter 균주들과 같은 진화 과정을 거쳐온 것으로 사료된다. Ribosomal 5S RNA was isolated and sequenced from the methylotrophic Acetobacter sp. KM by direct chemical method. Acetobacter sp. KM contained RNAs belonging to the 121 nucleotide type. The sequence of the cytoplasmic rRNA from Acetobacter sp. KM was compared to the known 5S rRNA sequences of 11 strains of the genus Acetobacter and 2 strains of the Gluconobacter. Based on Kimura's Knuc values, Acetobacter sp. KM was phylogenetically closer to non-methylotrophic Acetobacter group such as Acetobacter pasteurianus than to any other strains of Acetobacter or Gluconobacter.

A Distributed Deadlock Detection and Resolution Algorithm Based on a Hybrid Graph Construction Probe Generation Scheme

Park,Young Chul,Park,Yang Soo,Cheung,Young-Phil 울산대학교 1993 공학연구논문집 Vol.24 No.1

본 논문은 분산 데이타베이스 시스템에서의 교착상태 검출 및 회복을 위한 주기적 알고리즘을 제시한다. 이 알고리즘은 명시적, 암시적 교착 상태들을 초기에 검출할 수 있도록 하며 이를 위해 각 사이트에 확정된 트랜잭션 대기 그래프(TWFG)를 유지한다. 확장된 트랜잭션 대기 그래프는 로크 정보 뿐만 아니라 트랜잭션 에이젼트들간의 메시지-대기 정보 및 주종 관계에 대한 정보, 그리고 트랜잭션 완료 프로토콜에 관련된 트랜잭션들의 상태정보들도 포함한다. 각 사이트 간 메시지의 수효를 최소로 가진 전역 교착상태를 검출하고 회복하기 위해서는 프로브 생성 기법을 변형하여 사용하며 제시된 알고니즘은 각 사이트에 두개의 메모리 풀을 유지한다. 하나의 풀은 수신한 프로브들을 유지하며, 다른 하나의 풀은 보낸 프로브들의 수신에 대한 정보를 유지한다. 각 지역 사이트의 트랜잭션 대기 그래프에 포함된 정보와 수령한 프로브드들을 사용하여 주기적으로 교착상태를 검사한다. 송신한 프로브에 대한 수신 정보는 동일한 프로브의 전송를 피하기 위해 사용하며 또한 대항 프로브들을 전송하기 위해서도 사용한다. 이 알고리즘은 다중 사이트에서 트랜잭션들의 병렬수행을 허가하며 다중 로크 모드 및 로크 변환을 지원한다. We present a periodic algorithm for deadlock detection and resolution in distributed database systems, which allows for early detection of explicit and implicit deadlocks. Our algorithm uses an augmented transaction wait-for graph (TWFG) at each site, which contains in addition to lock-wait information, also information about message-wait and master-slave relationships among agents of a transaction, and status of transactions with respect to the commitment protocol. In order to detect and resolve global deadlocks with a minimal number of inter-site messages we adopt a modified version of the probe generation scheme such that two pools are maintained at each site. One pool keeps probes received, while the other keeps the receipts of probes sent. Periodically, we check for deadlocks by using the information contained in the local TWFGs and the probes received. The receipts of probes sent are used to avoid retransmission of the same probe and also to transmit antiprobes. Our algorithm allows for parallel execution of transactions at multiple sites and supports multiple modes of locks and lock conversion.

Histone H4 is cleaved by granzyme A during staurosporine-induced cell death in B-lymphoid Raji cells

( Phil Young Lee ),( Byoung Chul Park ),( Seung Wook Chi ),( Kwang-hee Bae ),( Sunhong Kim ),( Sayeon Cho ),( Seongman Kang ),( Jeong-hoon Kim ),( Sung Goo Park ) 생화학분자생물학회(구 한국생화학분자생물학회) 2016 BMB Reports Vol.49 No.10

Granzyme A (GzmA) was first identified as a cytotoxic T lymphocyte protease protein with limited tissue expression. A number of cellular proteins are known to be cleaved by GzmA, and its function is to induce apoptosis. Histones H1, H2B, and H3 were identified as GzmA substrates during apoptotic cell death. Here, we demonstrated that histone H4 was cleaved by GzmA during staurosporine-induced cell death; however, in the presence of caspase inhibitors, staurosporine-treated Raji cells underwent necroptosis instead of apoptosis. Furthermore, histone H4 cleavage was blocked by the GzmA inhibitor nafamostat mesylate and by GzmA knockdown using siRNA. These results suggest that histone H4 is a novel substrate for GzmA in staurosporine-induced cells. [BMB Reports 2016; 49(10): 560-565]

Engineering Properties of Eco-Permeable Polymer Concretes Using Blast Furnace Slag Powder and Stone Dust

Park Phil Woo,Sung Chan Yong The Korean Society of Agricultural Engineers 2004 한국농공학회논문집 Vol.46 No.7

Permeable polymer concrete can be applied to roads, sidewalks, river embankments, drain pipes, conduits, retaining walls, yards, parking lots, plazas, interlocking blocks, etc. This study was to explore a possibility of using blast furnace slag powder and stone dust of industrial by-products as fillers for Eco-permeable polymer concrete. Different mix proportions were tried to find an optimum mix proportion of the Eco­permeable polymer concrete. The tests were carried out at $20{\pm}1^{circ}C$ and $60{\pm}2\%$ relative humidity. At 7 days of curing, unit weight, coefficient of permeability, dynamic modulus of elasticity, compressive, flexural and splitting tensile strengths ranged between $1,821{\~}1,955 kg/m^{3}$, $0.056{\~}0.081\;cm/s$, $114{\times}0^{2}{\~}157{\times}10^{2}\;MPa,\;17.6{\~}24.7\;MPa,\;5.98{\~}7.94\;MPa\;and\;3.43{\~}4.70\;MPa$, respectively. It was concluded that the blast furnace slag powder and stone dust can be used in the Eco-permeable polymer concrete.