선(善)의 보편성(普遍性)과 실현근거 관한 우담(愚潭)과 록문(鹿門)의 이해 -리통기국(理通氣局)에 대한 해석을 중심으로-

손홍철 ( Heung Chul Son ) 한국철학사연구회 2010 한국 철학논집 Vol.0 No.28

철근 콘크리트 연속 유공 깊은 보의 전단내력에 관한 해석적 연구

박우진,이종권,이리형 대한건축학회 2004 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.24 No.1(구조계)

The purpose of this report is investigation of shear behaviors of the deep beam through non-lineal Finite Element Method based on experimental results of continuous deep with opening. Optimum condition for analysis was selected by means of adopting various material property as variables, and additional models including different position of opening selected as variables was simulated. Also experimental result was calibrated by two formula suggested by AIJ and CIRIA, considering effect of opening in the continuous deep beams. As a result of calibration, it is possibly estimated that shear strength formula suggested by AIJ(the Architectural Institute of Japan) can be also adopted as formula for continuous beam. It is expected that results of this research which evaluated shear behavior of the continuous deep beam through non-lineal Finite Element Method can be applied data for reinforcement in the vicinity of opening in the continuous deep beams.

Simultaneous achievement of equiaxed grain structure and weak texture in pure titanium via selective laser melting and subsequent heat treatment

Li, Cheng-Lin,Won, Jong Woo,Choi, Seong-Woo,Choe, Jung-Ho,Lee, Sangwon,Park, Chan Hee,Yeom, Jong-Taek,Hong, Jae Keun Elsevier 2019 Journal of alloys and compounds Vol.803 No.-

<P><B>Abstract</B></P> <P>We used selective laser melting (SLM) to produce a three-dimensional specimen of pure Ti and found that an equiaxed grain structure and weak crystallographic texture could be achieved simultaneously via subsequent heat treatment. These traits have never been attained simultaneously in pure Ti prepared by traditional methods such as casting and rolling. This remarkable achievement was possible because recrystallization occurred during heat treatment without plastic deformation; such deformation introduces stored energy that drives recrystallization but inevitably causes a strong texture to develop. The occurrence of recrystallization was attributed to unique features of the SLM process including a very high cooling rate and repetitive layer stacking. These features generated considerable stored energy by affecting solidification and the <I>β</I> → <I>α</I> phase transformation. Steep in-grain orientation gradients and a fine lath structure also contributed to the activation of recrystallization by facilitating recrystallization nucleation. The heat-treated specimen showed tensile properties with significantly reduced anisotropy. This finding will provide new strategies for developing isotropic metallic materials and may introduce new applications of SLM.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A three-dimensional specimen of pure Ti was produced using selective laser melting. </LI> <LI> Both equiaxed structure and weak texture were achieved by subsequent heat treatment. </LI> <LI> These traits cannot be attained simultaneously by traditional manufacturing methods. </LI> <LI> This desirable ability of SLM originates from unique features of SLM process. </LI> <LI> The heat-treated sample had significantly reduced anisotropy in tensile properties. </LI> </UL> </P>

Effects of Ga-doping on the microstructure and magnetic properties of MnBi alloys

Yang, Yang,Kim, Jong-Woo,Si, Ping-Zhan,Qian, Hui-Dong,Shin, Yongho,Wang, Xinyou,Park, Jihoon,Li, Oi Lun,Wu, Qiong,Ge, Hongliang,Choi, Chul-Jin Elsevier 2018 JOURNAL OF ALLOYS AND COMPOUNDS Vol.769 No.-

<P><B>Abstract</B></P> <P>The low temperature phase Mn<SUB>55</SUB>Bi<SUB>45-<I>x</I> </SUB>Ga<SUB> <I>x</I> </SUB> (<I>x</I> = 0, 1, 3, 5, and 10) alloys were prepared by induction melting process with subsequent low temperature annealing. The effects of Ga-doping on the crystal structure and magnetic properties of the alloys were systematically studied. The room temperature coercivities of Mn<SUB>55</SUB>Bi<SUB>45-<I>x</I> </SUB>Ga<SUB> <I>x</I> </SUB> after ball milling increased from 1.43 T for <I>x</I> = 0 to 1.66 T for <I>x</I> = 5, while the saturation magnetization decreased from 60.7 Am<SUP>2</SUP>/kg (<I>x</I> = 0) to 45.1 Am<SUP>2</SUP>/kg (<I>x</I> = 5). The maximum energy product (<I>BH</I>)<SUB>max</SUB> of Mn<SUB>55</SUB>Bi<SUB>44</SUB>Ga powders reached 7.87 MGOe. The Curie temperature of the Mn<SUB>55</SUB>Bi<SUB>45-<I>x</I> </SUB>Ga<SUB> <I>x</I> </SUB> alloys increased from 633 K to 658 K with increasing Ga concentration in the range of 0 ≤ <I>x</I> ≤ 5.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Effects of doping Ga on the microstructural and magnetic properties of MnBi alloy. </LI> <LI> The MnBi-Ga powders are achieved by surfactant assisted high energy ball milling. </LI> <LI> The maximum energy produce (<I>BH</I>)<SUB>max</SUB> shows 7.87 MGOe for Mn<SUB>55</SUB>Bi<SUB>44</SUB>Ga sample. </LI> <LI> The coercivity of Mn<SUB>55</SUB>Bi<SUB>40</SUB>Ga<SUB>5</SUB> after ball milling reached 1.66 T at room temperature. </LI> <LI> The elevated curie temperature (<I>T</I> <SUB>c</SUB>) by doping Ga makes it a possible candidate for high temperature applications. </LI> </UL> </P>

Seasonal production of dinoflagellate cysts in relation to environmental characteristics in Jinhae-Masan Bay, Korea: One-year sediment trap observation

Shin, Hyeon Ho,Li, Zhun,Lim, Dhongil,Lee, Kyun-Woo,Seo, Min Ho,Lim, Weol Ae Academic Press in association with the Estuarine a 2018 Estuarine, coastal and shelf science Vol.215 No.-

<P><B>Abstract</B></P> <P>To investigate dinoflagellate cyst production and seasonality in relation to major environmental factors, such as water temperature, salinity, chlorophyll-<I>a</I> (chl-<I>a</I>) and dissolved nutrients, and to propose dinoflagellate cysts as possible biological indicators for the reconstruction of past environmental conditions, a sediment trap study was conducted for one year, from March 2011 to February 2012, in Jinhae-Masan Bay, Korea. Marked increases in dinoflagellate cyst production were documented in Jinhae-Masna Bay during two distinct seasons (summer and late autumn) characterized by different environmental conditions. Summer (July and August) was characterized by relatively high water temperature, dissolved inorganic nitrogen (DIN), and chl-<I>a</I> concentrations and low salinity, whereas late autumn (November and December) exhibited high dissolved inorganic phosphorus, low water temperature and high salinity, compared to those of the summer. Fourteen dinoflagellate cyst taxa were identified. These assemblages were dominated by <I>Brigantedinium</I> species (round brown cyst), cysts of <I>Scrippsiella</I> species, <I>Spiniferites</I> species and cysts of <I>Alexandrium</I> species (ellipsoidal cyst). The total flux of dinoflagellate cysts ranged from 781 cysts m <SUP>−2</SUP> day <SUP>−1</SUP> to 5602 cysts m <SUP>−2</SUP> day <SUP>−1</SUP>, and the production of autotrophic dinoflagellate cysts was mainly restricted to the warmest months (July–September) and autumn. Multivariable analysis revealed that the production of major dinoflagellate cysts, excluding those of <I>Brigantedinium</I> species, can be enhanced by environmental conditions during summer in Jinhae-Masan Bay. In particular, the increased production of cysts of <I>Scrippsiella</I> species was related to increased water temperature, and the increased production of <I>Spiniferites</I> species was associated with lower salinity. Two peaks in cyst production of <I>Alexandrium</I> species in August and November corresponded with significant increases in DIN and DIP; however, no significant relationship was found between the production of <I>Brigantedinium</I> species and environmental factors in Jinhae-Masan Bay. These results suggest that the cysts of <I>Scrippsiella</I> species, <I>Spiniferites</I> species and cysts of <I>Alexandrium</I> species present in sediment samples from Jinhae-Masan Bay can be used as biological indicators to reconstruct past environmental conditions involving relatively high water temperature, low salinity and enhanced nutrient level.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Sediment trap study provides reliable information for dinoflagellate cyst production related to environmental conditions. </LI> <LI> Cysts of <I>Scrippsiella</I> species, <I>Spiniferites</I> species and cysts of <I>Alexandrium</I> species are most abundant in the warmest months. </LI> <LI> Cysts of <I>Scrippsiella</I> species, <I>Spiniferites</I> species and cysts of <I>Alexandrium</I> species can be used as biological indicators. </LI> </UL> </P>

Preconditioning of canine adipose tissue-derived mesenchymal stem cells with deferoxamine potentiates anti-inflammatory effects by directing/reprogramming M2 macrophage polarization

Park, Su-Min,Li, Qiang,Ryu, Min-Ok,Nam, Aryung,An, Ju-Hyun,Yang, Ji-In,Kim, Sang-Min,Song, Woo-Jin,Youn, Hwa-Young Elsevier 2020 Veterinary immunology and immunopathology Vol. No.

<P><B>Abstract</B></P> <P>Preconditioning with hypoxia or hypoxia-mimetic agents has been tried with mesenchymal stem cells (MSCs) to improve the secretion of anti-inflammatory factors. These preconditioning procedures upregulate hypoxia inducible factor (HIF) 1-alpha leading to the transcription of HIF-dependent tissue protective and anti-inflammatory genes. Due to the limited number of studies exploring the activity of deferoxamine (DFO)—a hypoxia-mimetic agent—in MSCs, we aimed to determine whether DFO can enhance the secretion of anti-inflammatory substances in canine adipose tissue-derived (cAT)-MSCs. Furthermore, we investigated whether this activity of DFO could affect macrophage polarization and activate anti-inflammatory reactions. cAT-MSCs preconditioned with DFO exhibited enhanced secretion of anti-inflammatory factors such as prostaglandin E2 and tumor necrosis factor-α-stimulated gene-6. To evaluate the interaction between DFO preconditioned cAT-MSCs and macrophages, RAW 264.7 cells were co-cultured with cAT-MSCs using the Transwell system, and changes in the expression of factors related to macrophage polarization were analyzed using the quantitative real-time PCR and western blot assays. When RAW 264.7 cells were co-cultured with DFO preconditioned cAT-MSCs, the expression of M1 and M2 markers decreased and increased, respectively, compared to co-culturing with non-preconditioned cAT-MSCs. Thus, cAT-MSCs preconditioned with DFO can more effectively direct and reprogram macrophage polarization into the M2 phase, an anti-inflammatory state.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Deferoxamine enhances the secretion of anti-inflammatory substances in cAT-MSCs. </LI> <LI> DFO preconditioned cAT-MSCs exhibit enhanced prostaglandin E2 and TSG-6 secretion. </LI> <LI> DFO preconditioned cAT-MSCs reprogram macrophage polarization into the M2 phase. </LI> <LI> Preconditioning of cAT-MSCs with DFO may be applicable clinically. </LI> </UL> </P>

Microstructural response of β-stabilized Ti–6Al–4V manufactured by direct energy deposition

Narayana, P.L.,Lee, Sangwon,Choi, Seong-Woo,Li, Cheng-Lin,Park, Chan Hee,Yeom, Jong-Taek,Reddy, N.S.,Hong, Jae-Keun Elsevier 2019 Journal of Alloys and Compounds Vol.811 No.-

<P><B>Abstract</B></P> <P>The present study describes the influence of β stabilizers (namely Fe and Cr) on the microstructural evolution and mechanical behavior of Ti–6Al–4V alloy fabricated by direct energy deposition. As the β stabilizer content increases from 1 to 4 wt%, the coarse columnar-grained morphology typical of additively manufactured Ti–6Al–4V is significantly refined, with a columnar-to-equiaxed transition. Furthermore, reheating of the deposited layers by the deposition of overlaying layers during fabrication induces an element partitioning effect, resulting in the formation of fine-grained α and isothermal ω. Hence, the heat profile during direct energy deposition resembles conventional solution and aging treatments. In addition, increasing the amount of β stabilizer steadily increases the room temperature strength of the Ti–6Al–4V alloy. The alloy with 4 wt% Fe showed the maximum strength, of ∼1.5 GPa.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The columnar-to-equiaxed transition of microstructure was achieved in the direct energy deposited Ti–6Al–4V alloy with the addition of Fe and Cr. </LI> <LI> The maximum room temperature strength of the Ti–6Al–4V with 4 wt% Fe alloy reaches ∼1.5 GPa. </LI> <LI> The reheating phenomenon caused by deposition of overlying layers during direct energy deposition resembles conventional solution and aging treatments. </LI> <LI> With an increasing amount of β stabilizer, the phase constituents in the Ti–6Al–4V alloy changed from αʹ .→ αʹ+α+ω+β → α+ω+β </LI> </UL> </P>

Ideal conducting polymer anode for perovskite light-emitting diodes by molecular interaction decoupling

Jeong, Su-Hun,Kim, Hobeom,Park, Min-Ho,Lee, Yeongjun,Li, Nannan,Seo, Hong-Kyu,Han, Tae-Hee,Ahn, Soyeong,Heo, Jung-Min,Kim, Kwang S.,Lee, Tae-Woo Elsevier 2019 Nano energy Vol.60 No.-

<P><B>Abstract</B></P> <P>An ideal conducting polymer anode (CPA) in organic and perovskite light-emitting diodes (LEDs) requires high electrical conductivity <I>κ</I>, high work function <I>WF</I>, and prevention of exciton quenching between an anode and an overlying emitting layer. However, increasing the <I>κ</I> and <I>WF</I> at the same time has been a very challenging unsolved issue due to their trade-off relationship: previous approaches to increase the <I>WF</I> have reduced the films’ <I>κ</I> and vice versa. Therefore, delicate molecular scale control of the conducting polymer compositions are required to solve this fundamental issue. Here, we introduce an effective molecular scale control strategy to decouple the <I>WF</I> with <I>κ</I> in a CPA while maintaining blocking capability of exciton quenching. This change resulted in a high current efficiency up to 52.86 cd A<SUP>−1</SUP> (10.93% ph el<SUP>−1</SUP>) in green polycrystalline perovskite LEDs. Our results provide a significant clue to develop effective CPAs for highly-efficient organic and perovskite LEDs.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Ideal conducting polymer anode with high work function and conductivity for high-efficiency perovskite LED is introduced. </LI> <LI> Molecular scale control is introduced to decouple the work function with conductivity in a conducting polymer anode. </LI> <LI> We achieved a high-efficiency polycrystalline perovskite LEDs with an external quantum efficiency of 10.93%. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Disruption of endothelial barrier function is linked with hyposecretion and lymphocytic infiltration in salivary glands of Sjögren's syndrome

Cong, Xin,Zhang, Xue-Ming,Zhang, Yan,Wei, Tai,He, Qi-Hua,Zhang, Li-Wei,Hua, Hong,Lee, Sang-Woo,Park, Kyungpyo,Yu, Guang-Yan,Wu, Li-Ling Elsevier 2018 Biochimica et biophysica acta. Molecular basis of Vol.1864 No.10

<P><B>Abstract</B></P> <P>Sjögren's syndrome (SS) is an inflammatory autoimmune disease that causes hyposecretion in salivary glands. Endothelial tight junctions (TJs) play crucial roles in salivation and barrier function of blood vessels. However, whether the alteration of endothelial TJs were involved in pathogenesis of SS was still unknown. Here, the ultrastructure and function of endothelial TJs in submandibular glands (SMGs) were detected by transmission electron microscopy and in vivo paracellular permeability assay in different aged NOD mouse model for SS. CFSE-labeled lymphocytes were injected into tail vein to trace the infiltration, while claudin-5 expression and distribution were detected by immunofluorescence, qRT-PCR, and western blot. Results showed that the stimulated salivary flow rate was gradually decreased and lymphocytic infiltration was found as age increased in 12- and 21-week-old NOD mice, but not 7-week-old NOD mice. Blood vessels were dilated, while endothelial TJ width and paracellular tracer transport were increased in 12-week-old NOD mice. Moreover, the injected CFSE-labeled lymphocytes were observed in SMGs of 12-week-old NOD mice. Claudin-5 level was increased and relocalized from the apical portion of neighboring endothelial cells to lateral membranes and cytoplasm in 12-week-old NOD mice. Additionally, the alteration of claudin-5 expression and distribution was further confirmed in labial salivary glands and bilateral parotid glands from SS patients. In cultured human microvessel endothelial cell line (HMEC-1), IFN-γ stimulation significantly increased claudin-5 expression. Taken together, we identified that the endothelial TJ barrier was disrupted and contributed to the development of salivary hyposecretion and lymphocytic infiltration in SS.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Endothelial tight junction barrier is disrupted in hyposecretory submandibular glands from Sjögren's syndrome mouse model </LI> <LI> The disrupted salivary endothelial barrier is linked with lymphocytic infiltration in Sjögren's syndrome mouse model </LI> <LI> The redistribution of claudin-5 is responsible for disrupted endothelial barrier in salivary glands from Sjögren's syndrome </LI> </UL> </P>

Influence of backbone modification of difluoroquinoxaline-based copolymers on the interchain packing, blend morphology and photovoltaic properties of nonfullerene organic solar cells

Li, Yuxiang,Kim, Minseok,Wu, Ziang,Lee, Changyeon,Lee, Young Woong,Lee, Jin-Woo,Lee, Young Jun,Wang, Ergang,Kim, Bumjoon J.,Woo, Han Young The Royal Society of Chemistry 2019 Journal of Materials Chemistry C Vol.7 No.6

<P>In order to understand the influence of molecular ordering and orientation on the performance of nonfullerene (NF) solar cells, we synthesized a series of difluoroquinoxaline-based alternating copolymers: starting from poly(2,2′-bithiophene-<I>alt</I>-(2,3-bis(3,4-bis(octyloxy)phenyl)-6,7-difluoroquinoxaline)) (PDFQx-2T), we modified the polymeric backbone by incorporating fluorine atoms (PDFQx-2T2F) or thiophene (PDFQx-3T) or a benzene ring (PDFQx-2TB) in the bithiophene comonomeric unit. The structure modification significantly affected the photovoltaic performance with power conversion efficiencies (PCEs) of 3.95% for PDFQx-2TB:ITIC, 4.82% for PDFQx-2T:ITIC, 4.93% for PDFQx-2T2F:ITIC and 8.13% for PDFQx-3T:ITIC. The dramatic increase in the PCE of PDFQx-3T:ITIC was attributed to improvements in the short-circuit current density (<I>J</I>SC) and fill factor (FF). From the resonant soft X-ray scattering and grazing incidence X-ray scattering measurements, the PDFQx-3T polymers had well-developed, face-on oriented crystallites, allowing the formation of face-to-face alignment with the face-on ordered ITIC molecules at the interfaces. Also, the PDFQx-3T:ITIC blend films exhibited well intermixed blend morphology with smaller domain spacings. These combined features contributed to efficient charge generation with the highest exciton dissociation probability among the four different polymer:ITIC systems. In addition, dominant face-on orientation of both PDFQx-3T polymers and ITIC acceptors with a balanced crystalline coherence length ratio (CCLpolymer/CCLITIC) (0.87, based on the out-of-plane (010) diffraction peaks of PDFQx polymers and ITIC acceptors) led to a more balanced charge mobility than other blends, explaining the highest <I>J</I>SC and FF in the PDFQx-3T:ITIC NF devices.</P>