• Title/Summary/Keyword: Dense plasma

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Crystal Orientation of Thin Films Prepared by Facing Targets Sputtering (대향타겟스퍼터링으로 제작된 박막의 결정 배향성)

  • 김경환;손인환;송기봉;신촌수양;중천무수;직강정언
    • Journal of the Korean institute of surface engineering
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    • v.31 no.4
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    • pp.217-222
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    • 1998
  • The Facing Targets Sputtering(FTS) system has several advantages for preparing films over a wide range of working gas pressure on plasma-free substrates. Co-Cr thin films seem to be one of the most promising media for perpendicular magnetic recording system. In this study, the capabillities of the system fordepositing C0-Cr films have been investigated. Under various Ar gas pressure, films with morphologically dense microstructure and good c-axis orientation were deposited, even when the incident angle $\psi_x$ of sputtered part icles to the film plane was below abount $50^{\circ}C$. this may imply that the shadowing effect by obique incidence of particle can be compensated by rapid surface diffusion owing to the high kinetic energy of particles arriving at the growing film. It has been confirmed that the FTS system is very useful for perparing Co-Cr thin films recorging media.

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A Case of Immunoglobulin G4-Related Disease Presenting as a Pleural Mass

  • Kim, Dong Hyun;Koh, Kyu Han;Oh, Hyeon Sik;Kim, Se Joong;Kang, Sae Han;Jung, Byung Wook;Song, Jun Gyu;Cheon, Mi Ju;Yoon, Seon Bin;Park, Yong Won;Ko, Young Min;Lee, Seung Hyeun
    • Tuberculosis and Respiratory Diseases
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    • v.76 no.1
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    • pp.38-41
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    • 2014
  • Immunoglobulin G4 (IgG4)-related disease is a newly recognized condition characterized by fibroinflammatory lesions with dense lymphoplasmacytic infiltration, storiform-type fibrosis and obliterative phlebitis. The pathogenesis is not fully understood but multiple immune-mediated mechanisms are believed to contribute. This rare disease can involve various organs and pleural involvement is even rarer. We report a case of IgG4-related disease involving pleura. A 66-year-old man presented with cough and sputum production for a week. Chest radiography revealed consolidation and a pleural mass at right hemithorax. Treatment with antibiotics resolved the consolidation and respiratory symptoms disappeared, but the pleural mass was unchanged. Video-assisted thoracoscopic surgery was performed. Histopathology revealed dense lymphoplasmacytic infiltration and storiform fibrosis with numerous IgG4-bearing plasma cells. The serum IgG4 level was also elevated. Further examination ruled out the involvement of any other organ. The patient was discharged without further treatment and there is no evidence of recurrence to date.

Ultrastructural characteristics of the pancreatic acinar cells in the diabetes-prone BB rat (BB랫드의 췌장 샘포세포의 미세구조적 특징)

  • Jeong, Young-gil;Kim, Kil-soo;Lee, Chul-ho;Won, Moo-ho;Cho, Sung-whan;Kim, Moo-kang
    • Korean Journal of Veterinary Research
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    • v.36 no.1
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    • pp.1-9
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    • 1996
  • Functional and morphological characteristics of the exocrine pancreas in genetic model BB rat of insulin dependent diabetes medllitus(IDDM) were carried out. Wistar rat was used as control animal. Flow rate of pancreatic juice, output of amylase and protein, and plasma glucose and insulin levess were examined. Also light and ultrastructural characteristics of the exocrine pancreas were observed. Pancreatic flow rate, output of amylase and protein, and insulin level were lower;glucose level was higher comparing with those of the control Wistar rat. In Wistar rat, exocrine pancreas was typical light microscopically. Zymogen granules and cell organelles were well developed in fine structure. Cell size of the periinsular acini was larger, and number of zymogen granules were more than those of the teleinsular acini. Most acinar cells were dark cells which containe well-developed RER in their cytoplasm. On the other hand, some light cells which have the dilated RER cisterns were found. In BB rat exocrine pancreas, cell size of per-and tele-insular acini similar to that of Wistar rat. The number of light cells occupied 40-50% compairing with that of Wistar rat. Zymogen granules were lower in number than that of Wistar rat and divied into three types in morphological characteristics ; type I showing normal structure, type II showing the wide hallo and small electron dense core in center of the zymogen granule and type III not having the electron dense core in the zymogen granule. The present ratio of type I, type II and type III are less than 5%, 30-40% and more than 50%, respectively.

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Ultrastructural Study on Connective Tissue-Epithelial Junctions in Anagen Hair Follicle of Human Fetus (사람태아 성장기 모낭에서 결합조직-상피 경계부의 미세구조에 관한 연구)

  • Kim, Baik-Yoon;Park, Min-Ah;Nam, Kwang-Il
    • Applied Microscopy
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    • v.27 no.3
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    • pp.321-332
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    • 1997
  • The dermal papilla is known to playa major role in influencing the form and dynamics of the hair follicle, which probably involves regulatory substances crossing the basal lamina. But little is known about the junctions between the dermal papilla and the surrounding epithelial cells of the hair bulb, or between the connective tissue and the epithelial cells on the outside of the hair follicle. This study was performed to identify the ultrastructural differences between dermoepidermal junction of the skin and connective tissue-epithelial junctions on the outside of the hair follicle and around the dermal papilla of normal anagen hair follicles in the human fetal scalp skin. Electron microscopic findings of dermoepidermal junction in scalp skin showed that basal lamina was very irregular and undulated, and it contained many attachment plaques of hemidesmosomes with sub-basal dense plates, tonofilaments, and anchoring filaments. Also invaginations of plasma membrane of basal keratinocytes were seen. There were clear differences both on the outside of the follicle and around the dermal papilla as compared with similar junction in the skin. In particular, neither hemidesmosomes nor tonofilaments, as seen in dermoepidermal junction, were observed in the dermal papilla. Also attachment plaque, sub-basal dense plate and anchoring filaments were not observed at the junction on the outside of the follicle and the dermal papilla. There were some differences between connective tissue-epithelial junctions on the outside of the hair follicle and around the dermal papilla, ie, smoothness of basal lamina and orthogonal arrangement of collagen fibers were seen in the outside of hair follicle, but not in the dermal papilla. These results indicate that the mechanical connection between the hair follicle and the connective tissue component is much weaker than that between the corresponding components in skin, and it reflects the dynamic processes during the anagen phase of the hair follicle compared to the relatively permanent state of the epidermis.

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ALD-assisted Hybrid Processes for improved Corrosion Resistance of Hard coatings

  • Wan, Zhixin;Kwon, Se-Hun
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2016.11a
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    • pp.105-105
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    • 2016
  • Recently, high power impulse magnetron sputtering (HIPIMS) has attracted considerable attentions due to its high potential for industrial applications. By pulsing the sputtering target with high power density and short duration pulses, a high plasma density and high ionization of the sputtered species can be obtained. HIPIMS has exhibited several merits such as increased coating density, good adhesion, microparticle-free and smooth surface, which make the HIPIMS technique desirable for synthesizing hard coatings. However, hard coatings present intrinsic defects (columnar structures, pinholes, pores, discontinuities) which can affect the corrosion behavior, especially when substrates are active alloys like steel or in a wear-corrosion process. Atomic layer deposition (ALD), a CVD derived method with a broad spectrum of applications, has shown great potential for corrosion protection of high-precision metallic parts or systems. In ALD deposition, the growth proceeds through cyclic repetition of self-limiting surface reactions, which leads to the thin films possess high quality, low defect density, uniformity, low-temperature processing and exquisite thickness control. These merits make ALD an ideal candidate for the fabrication of excellent oxide barrier layer which can block the pinhole and other defects left in the coating structure to improve the corrosion protection of hard coatings. In this work, CrN/Al2O3/CrN multilayered coatings were synthesized by a hybrid process of HIPIMS and ALD techniques, aiming to improve the CrN hard coating properties. The influence of the Al2O3 interlayer addition, the thickness and intercalation position of the Al2O3 layer in the coatings on the microstructure, surface roughness, mechanical properties and corrosion behaviors were investigated. The results indicated that the dense Al2O3 interlayer addition by ALD lead to a significant decrease of the average grain size and surface roughness and greatly improved the mechanical properties and corrosion resistance of the CrN coatings. The thickness increase of the Al2O3 layer and intercalation position change to near the coating surface resulted in improved mechanical properties and corrosion resistance. The mechanism can be explained by that the dense Al2O3 interlayer acted as an excellent barrier for dislocation motion and diffusion of the corrosive substance.

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Effects of Gas Chemistries on Poly-Si Plasma Etching with I-Line and DUV Resist (I-Line과 DUV Resist에서 Poly-Si 플라즈마 식각시 미치는 개스의 영향)

  • 신기수;김재영
    • Journal of the Korean Vacuum Society
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    • v.7 no.2
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    • pp.155-160
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    • 1998
  • It is necessary to use Arc layer and DUV resist to define 0.25 $\mu \textrm{m}$ line and space for 256 MDRAM devices. Poly-Si etching with Arc layer and different resists has been performed in a TCP-9408 etcher with variation of gas chemistries; $Cl_2/O_2, Cl_2/N_2, Cl_2$/HBr . DUV resist causes more positive etch profile and CD gain compared to I-line resist because the sidewall passivation is more stimulated by increasing polymerization through the loss of resist. When Arc layer is applied, CD hain also increases due to the polymeric mask formed after thching Arc layer. From the point of gas chemistry effects, the etch profile and CD gain is not improved using $Cl_2/O_2$ gas, since polymerization is accelerated in this gas. however, the vertical profile and less CD gain is obtained using $Cl_2$/HBr gas. Furthermore, HBr gas is very effective to suppress the difference of profile and CD variation between dense pattern and isolated pattern by minimizing non-uniformity of side wall passivation with pattern density.

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Anti-thrombotic effects of ginsenoside Rk3 by regulating cAMP and PI3K/MAPK pathway on human platelets

  • Hyuk-Woo Kwon ;Jung-Hae Shin ;Man Hee Rhee ;Chang-Eun Park ;Dong-Ha Lee
    • Journal of Ginseng Research
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    • v.47 no.6
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    • pp.706-713
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    • 2023
  • Background and objective: The ability to inhibit aggregation has been demonstrated with synthetically derived ginsenoside compounds G-Rp (1, 3, and 4) and ginsenosides naturally found in Panax ginseng 20(S)-Rg3, Rg6, F4, and Ro. Among these compounds, Rk3 (G-Rk3) from Panax ginseng needs to be further explored in order to reveal the mechanisms of action during inhibition. Methodology: Our study focused to investigate the action of G-Rk3 on agonist-stimulated human platelet aggregation, inhibition of platelet signaling molecules such as fibrinogen binding with integrin αIIbβ3 using flow cytometry, intracellular calcium mobilization, dense granule secretion, and thromboxane B2 secretion. In addition, we checked the regulation of phosphorylation on PI3K/MAPK pathway, and thrombin-induced clot retraction was also observed in platelets rich plasma. Key Results: G-Rk3 significantly increased amounts of cyclic adenosine monophosphate (cAMP) and led to significant phosphorylation of cAMP-dependent kinase substrates vasodilator-stimulated phosphoprotein (VASP) and inositol 1,4,5-trisphosphate receptor (IP3R). In the presence of G-Rk3, dense tubular system Ca2+ was inhibited, and platelet activity was lowered by inactivating the integrin αIIb/β3 and reducing the binding of fibrinogen. Furthermore, the effect of G-Rk3 extended to the inhibition of MAPK and PI3K/Akt phosphorylation resulting in the reduced secretion of intracellular granules and reduced production of TXA2. Lastly, G-Rk3 inhibited platelet aggregation and thrombus formation via fibrin clot. Conclusions and implications: These results suggest that when dealing with cardiovascular diseases brought upon by faulty aggregation among platelets or through the formation of a thrombus, the G-Rk3 compound can play a role as an effective prophylactic or therapeutic agent.

Characteristics of (Ca,Sr)-doped LaCrO3 Coating Layer for Ceramic Interconnect of Solid Oxide Fuel Cell (고체산화물 연료전지용 (Ca,Sr)도핑된 LaCrO3계 세라믹 연결재 코팅층의 특성 연구)

  • Lee, Gil-Yong;Peck, Dong-Hyun;Song, Rak-Hyun
    • Journal of the Korean Electrochemical Society
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    • v.8 no.4
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    • pp.162-167
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    • 2005
  • Using Pechini method, we synthesized the $La_{0.6}Ca_{0.41}CrO_3$ (LCC41) and $La_{0.8}Sr_{0.05}Ca_{0.15}CrO_3$ (LSCC) powders for slurry dip coating, and $La_{0.75}Ca_{0.27}CrO_3$ (LCC27) powder for air plasma spray coating. The sintering property of the powders and their coating properties were investigated. The average particle sizes of the LCC41, LSCC, LCC27 were 0.6, 0.9, $1.5{\mu}m$, respectively. The relative density of LCC41 bulk was to be found about 98%. The LSCC coating on anode support prevented Ca migration of the coated LCC41 on the anode some or less, which was confirmed from EDS result. The air plasma spray-coated LCC27 with the dip-coated LCC41 were more dense and showed better electrical conductivity than those of the air plasma spray-coated LCC27 and the dip-coated LSCC and LSCC41. The LCC41 and LCC27 showed good electrical conductivities, but the LSCC had a poor electrical conductivity probably due to low sinterability

Comparative Studies of Different Thermal Consolidation Techniques on Thermoelectric Properties of BiTeSe Alloy (BiTeSe 합금의 열적성형방법에 따른 열전특성)

  • Sharief, P.;Dharmaiah, P.;Lee, C.H.;Ahn, S.S.;Lee, S.H;Son, H.T;Hong, S.J.
    • Journal of the Korean Society for Heat Treatment
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    • v.31 no.3
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    • pp.126-134
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    • 2018
  • In this research, we produced polycrystalline n-type $Bi_2Te_{2.7}Se_{0.3}$ powder using water atomization. To obtain full benefit through water atomized powder, we have implemented spark plasma sintering and hot extrusion for powder compaction. The microstructure and thermoelectric properties were investigated and compared. The average grain size of SPS and extruded bulks were 3.08 and $3.86{\mu}m$ respectively. The extruded material microstructure contains layered grains with less grain boundaries and its counter-part SPS displays dense packed grains with high grain boundaries. Among both bulks, extrusion sample exhibited high power factor (PF) of $2.96{\times}10^{-3}Wm^{-1}K^{-2}$ which is 38% higher than SPS ($2.14{\times}10^{-3}$) bulk sample. Due to variations in grain size and grain boundaries, the SPS bulk shows low thermal conductivity than extruded bulk. However, the extruded bulk sample exhibited a peak ZT of 0.69 at 400 K, which is 19% higher than SPS bulk sample, due to its higher power factor.

Effect of SiC and WC additon on Oxidation Behavior of Spark-Plasma-Sintered ZrB2

  • Kim, Chang-Yeoul;Choi, Jae-Seok;Choi, Sung-Churl
    • Journal of Powder Materials
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    • v.26 no.6
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    • pp.455-462
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    • 2019
  • ZrB2 ceramic and ZrB2 ceramic composites with the addition of SiC, WC, and SiC/WC are successfully synthesized by a spark plasma sintering method. During high-temperature oxidation, SiC additive form a SiO2 amorphous outer scale layer and SiC-deplete ZrO2 scale layer, which decrease the oxidation rate. WC addition forms WO3 during the oxidation process to result in a ZrO2/WO3 liquid sintering layer, which is known to improve the anti-oxidation effect. The addition of SiC and WC to ZrB2 reduces the oxygen effective diffusivity by one-fifth of that of ZrB2. The addition of both SiC and WC shows the formation of a SiO2 outer dense glass layer and ZrO2/WO3 layer so that the anti-oxidation effect is improved three times as much as that of ZrB2. Therefore, SiC- and WC-added ZrB2 has a lower two-order oxygen effective diffusivity than ZrB2; it improves the anti-oxidation performance 3 times as much as that of ZrB2.