• Title/Summary/Keyword: Foam patterns

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Thermal post-buckling behavior of GPLRMF cylindrical shells with initial geometrical imperfection

  • Yi-Wen Zhang;Gui-Lin She;Lei-Lei Gan;Yin-Ping Li
    • Geomechanics and Engineering
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    • v.32 no.6
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    • pp.615-625
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    • 2023
  • Initial geometrical imperfection is an important factor affecting the structural characteristics of plate and shell structures. Studying the effect of geometrical imperfection on the structural characteristics of cylindrical shell is beneficial to explore the thermal post-buckling response characteristics of cylindrical shell. Therefore, we devote to investigating the thermal post-buckling behavior of graphene platelets reinforced mental foam (GPLRMF) cylindrical shells with geometrical imperfection. The properties of GPLRMF material with considering three types of graphene platelets (GPLs) distribution patterns are introduced firstly. Subsequently, based on Donnell nonlinear shell theory, the governing equations of cylindrical shell are derived according to Eulerian-Lagrange equations. Taking into account two different boundary conditions namely simply supported (S-S) and clamped supported (C-S), the Galerkin principle is used to solve the governing equations. Finally, the impact of initial geometrical imperfections, the GPLs distribution types, the porosity distribution types, the porosity coefficient as well as the GPLs mass fraction on the thermal post-buckling response of the cylindrical shells are analyzed.

Modification of Functional Properties of Soy Protein Isolate by Proteolytic Enzymes (단백분해효소에 의한 대두단백의 기능적 특성변화)

  • Cha, Myeong-Hwa;Yoon, Sun
    • Korean Journal of Food Science and Technology
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    • v.25 no.1
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    • pp.39-45
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    • 1993
  • The effects of enzymatic modification with pepsin and actinidin was studied on molecular weight distributions and functional properties of hydrolysates from soy protein isolate (SPI) differing in degree of hydrolysis. The hydrolyzed SPI by pepsin showed 41.5% degree of hydrolysis after 5 min, and maximum hydrolysis was obtained after 2 hours. Actinidin hydrolyzed SPI 26.71% degree after 1 hour. On SDS-PAGE, native SPI showed 9 distinguishable bands on SDS-PAGE gel. Pepsin treated SPI showed one broad band in the lower part of gel. This band was shifted further to the bottom of the gel and became faint as hydrolysis time increased. While actinidin treated SPI showed different SDS-PAGE pattern from pepsin. However PAGE patterns were similar with pepsin and actinidin treated groups. With pepsin treatment, solubility of SPI distinctively increased around isoelectric point(pI). Emulsifying activity (EA) and emulsifying stability (ES) showed marked increase over pH range of $3.0{\sim}8.0$. 5 min modified group had most excellent foam expansion (FE). Foam stability (FS) was increased as pepsin treatment time increased at pI. With actinidin treatment, solubility was increased. 60 min modified SPI had the most effective EA at pH 4.5. However ES was not effected by actinidin treatment. 5 min modified group was most effect in FE. FS was higher at alkaline pH.

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A Study on the Improvement of Multi-Layer Coating Method on Concrete Base (성형 콘크리트 복층마감도장 공법 개선에 관한 연구)

  • Kim, Chong-Weon;Choi, In-Sung
    • Journal of the Korea Institute of Building Construction
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    • v.3 no.1
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    • pp.93-105
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    • 2003
  • The Precast Concrete(PC) method was developed for a large production of a structure in Europe. Afterwards, this PC method has been applied to a structure and an outside Coating of buildings extensively. The outside Coating of the building applied this PC method is a method to put tiles or stones to base concrete. And there is a method to use paints for, so the expression of various patterns is possible. The Multi-Layer Coating is one of the methods to use paints. This Multi-Layer Coating method can show various designs of external appearance with Foam when it is made with the PC panel. Also, the paint film of the PC panel enables a splendid appearance, and a protective function of concrete is possible, too. Therefore, it makes good durability of the PC. Besides, maintenance is easy to manage because it is free from pollution when it uses metallic materials, stones, or any other materials. You might have no trouble in applying the Multi-Layer Coating method in order to save a merit of an outside Coating on the PC panel. However, the Multi-Layer Coating method used as a current outside Coating method has pollution and bad working environment because Oil Epoxy Resins have toxicity and flammability. Therefore, a lot of warnings are required for coating work in order to have appropriate quality because working hours are short, and production efficiency is low too. These reasons make the cost of construction of the Multi-Layer Coating method increase. And employers or designers may have problems in selecting this Multi-Layer Coating method. Therefore, the purpose of this study is to get activation of the Multi-Layer Coating method by offering improvement measures about the problems of the existing Multi-Layer Coating method.

Pathology and Classification of Focal Segmental Glomerulosclerosis (초점성 분절성 사구체 경화증의 병리와 분류)

  • Kim, Yong-Jin
    • Childhood Kidney Diseases
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    • v.16 no.1
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    • pp.21-31
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    • 2012
  • Focal segmental glomerulosclerosis (FSGS) is the name of the primary glomerular disease as well as the terminology to describe the secondary phenomena of any other glomerular diseases. It is characterized by sclerosis, hyalinosis, foam cell infiltration, vacuolar change of podocytes, and halo formation in the glomerulus. Throughout the interstitium, lymphocytes infiltration, tubular atrophy and vascular changes are accompanied. Occasionally, IgM and/or C3 depositions are noted in the sclerotic areas. Electron microscopically, diffuse effacement of foot processes are seen in non-sclerotic area like minimal change disease. Podocyte injury patterns including vacuolar changes are frequently examined. Recently, Columbia group has suggested morphologic classification of FSGS and they demonstrated very good prognosis of tip lesion and poor prognosis of both collapsing and cellular types. However, the pathogenetic classification has been suggested by others; hyperfilteration, podocyte injury, genetic lesions etc. Further studies are necessary to understand and treat this disease.

Design and Fabrication of Multiple U-shaped slot Microstrip Antenna for 5.25GHZ Band Wireless LAN (5-25GHZ 대역 무선 LAN 다중 U 슬롯 모양의 마이크로스트립 안테나 설계 및 제작)

  • 윤중한;정계택;최현규;곽경섭
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.6A
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    • pp.414-424
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    • 2003
  • In this paper, a multiple U-shaped slot antenna for 5.25㎓~5.35㎓ is designed, fabricated, and measured. The prototype consists of U-slot and two invert U-slot. To obtain enough bandwidth, the foam layer is inserted between ground plane and substrate. Important parameters in the design are U-slot length, width, position, airgap length, and feed point. From these parameters optimized, a multiple U-shaped slot antenna is fabricated and measured. The measured results of the antenna are compared with its simulated results. The resonant frequency of the fabricated multiple U-shaped slot antenna is 5.25㎓ the bandwidth for approximately 7.4%(VSWR<1.5) and the gain is 2.9~5.3dBi. The experimental far-field patterns are stable across the pass band. The 3dB bandwidth in H-Plane and I-Plane are 62$^{\circ}$ and 50$^{\circ}$, respectively.

A Study on the Design and Fabrication of a Dual-Ground and Broad-band Internal Antenna for 4th-Generation Mobile Communications (4세대 이동통신용 이중접지 내장형 광대역 안테나의 설계와 제작에 관한 연구)

  • Park, Jung-Ryul;Choi, Byoung-Ha;Kong, Jin-Woo;Yun, Hyun-Su;Kim, Gue-Chol
    • Journal of Advanced Navigation Technology
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    • v.12 no.2
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    • pp.100-108
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    • 2008
  • In this paper, the dual-ground, high-gain and broad-band internal antenna has been designed and fabricated for 4th-generation mobile communication applications. The optimized antenna was fabricated using photolithography method. The antenna consist of the patches, antenna and system ground, and a probe. The patch and ground plane were separated by air. In order to prevent the demage due to radiator swaying, the foams(${\varepsilon}_r{\fallingdotseq}1.03$) were used to fix the patches and ground. The conductor for the radiators was 0.05 [mm] thick. The measured input return loss showed less than -10 [dB] at the broadband from 3499 to 4743 [MHz]. It's measured bandwidth was 1244 [MHz]. The radiation patterns measured at 3400, 3600, 3800, 4000 and 4200 [MHz] showed Omni-directional characteristics. The gain in the E-plane and H-plane was 4.7 ~ 6.1 and 2.1 ~ 4.3 [dBi], respectively.

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Influence of surface treatment on the insertion pattern of self-drilling orthodontic mini-implants (표면처리가 교정용 미니 임플랜트의 식립수직력과 토크에 미치는 영향)

  • Kim, Sang-Cheol;Kim, Ho-Young;Lee, Sang-Jae;Kim, Cheol-Moon
    • The korean journal of orthodontics
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    • v.41 no.4
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    • pp.268-279
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    • 2011
  • Objective: The purpose of this study was to compare self-drilling orthodontic mini-implants of different surfaces, namely, machined (untreated), etched (acid-etched), RBM (treated with resorbable blasting media) and hybrid (RBM + machined), with respect to the following criteria: physical appearance of the surface, measurement of surface roughness, and insertion pattern. Methods: Self-drilling orthodontic mini-implants (Osstem implant, Seoul, Korea) with the abovementioned surfaces were obtained. Surface roughness was measured by using a scanning electron microscope and surface-roughness-testing machine, and torque patterns and vertical loadings were measured during continuous insertion of mini-implants into artificial bone (polyurethane foam) by using a torque tester of the driving-motor type (speed, 12 rpm). Results: The mini-implants with the RBM, hybrid, and acid-etched surfaces had slightly increased maximum insertion torque at the final stage ($p$ < 0.05). Implants with the RBM surface had the highest vertical load for insertion ($p$ < 0.05). Testing for surface roughness revealed that the implants with the RBM and hybrid surfaces had higher Ra values than the others ($p$ < 0.05). Scanning electron microscopy showed that the implants with the RBM surface had the roughest surface. Conclusions: Surface-treated, self-drilling orthodontic mini-implants may be clinically acceptable, if controlled appropriately.

Conservation of Iron Dagger & Scabbard Excavated in Daho-ri, Changwon (다호리 출토 칠초철검(漆鞘鐵劍)의 보존)

  • Sim, Myungbo;Lim, Jihyun;Ma, Daewan;Kim, Midori
    • Conservation Science in Museum
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    • v.12
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    • pp.19-24
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    • 2011
  • This study presents an investigation into the conservation process of an iron dagger and scabbard, which are a lacquered scabbard and a dagger inserted in it, excavated in the Daho-ri relic of Changwon by Gimhae National Museum. The bronze dagger whose condition was poor due to corrosion was coated with Incralac, an intensifier, to reveal the surface patterns through a microscope. The lacquered scabbard was removed of foreign substances on the surface and coated with HPC 2%(in water) to protect the film. Applied onto the surface from which foreign substances were removed was Caparol Binder 5%(in water) two to three times to form a protective film and then faced with Korean paper. Once it was fixed in a polyurethane foam in a stable manner, it was turned over to receive the same process on the back. Three layers of Korean paper were attached to the back of the scabbard to support the thin artifact. HPC 2%(in water), which was applied to the scabbard, was also applied to the iron dagger inside for cementing effect. After all the processes were completed, the artifact was put in a transparent acrylic box for future display.

Physicochemical and Functional Properties of Pepsin-modified Myofibrillar protein from Sardine, Sardinops melanostica (Pepsin으로 수식된 정어리 myofibrillar protein의 특성)

  • Kim, Byung-Mook;Kim, Byung-Ryul
    • Korean Journal of Food Science and Technology
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    • v.26 no.2
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    • pp.110-116
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    • 1994
  • In order to study the effects of enzyme modification on the physico-chemical and functional properties of myofibrillar protein prepared from the frozen sardine, Sardinops melanostica, the protein was hydrolyzed with pepsin under the enzyme-substrate ratio 1:100 at $37^{\circ}C$ and pH 1.65 for 1, 4, 8, 12, and 24 hr, respectively. The properties of pepsin-modified sardine myofibriliar protein were determined. The extents of proteolysis with pepsin as a fuction of time was showed a typical enzyme hydorlysis curve with an initial region of 4 hour period followed by plateau region. The SDS-acrylamide slab gel electrophoresis patterns of pepsin-modified proteins showed mainly disappearances of minor protein bands, but no changes of main protein bands. The gel filtration patterns through Sephadex G-75 of sardine myofibrillar protein showed two big peaks and three small peaks. All the small peaks were disappearanced by proteolysis with pepsin in one hour. and during the period of proteolysis the fast big peak became gradually smaller and the late big peak eluted more slowly. By proteolysis, the emulsifying activity and emulsifying capacity of sardine myofibrillar protein were all decreased. The effects of pepsin-modification on emulsifying capacity were greater than those on emulsifying activity of protein. The aeration capacity of the protein was increased about 1.9 folds and the foam stability decreased to 0.6 folds of control by pepsin-modification. The pepsin-modified sardine myofibrillar proteins showed about 0.6 folds of heat coagulation and 1.4 folds of viscosity of control. The pH dependence of solubilities of sardine myofibrillar protein showed two isoelectric areas of pH 5 and 9. The pepsin-modified protein showed more clear pH dependences at the early stage but not at the late stage of proteolysis.

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Broadening the Understanding of Sixteenth-century Real Scenery Landscape Painting: Gyeongpodae Pavilion and Chongseokjeong Pavilion (16세기(十六世紀) 실경산수화(實景山水畫) 이해의 확장 : <경포대도(鏡浦臺圖)>, <총석정도(叢石亭圖)>를 중심으로)

  • Lee, Soomi
    • MISULJARYO - National Museum of Korea Art Journal
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    • v.96
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    • pp.18-53
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    • 2019
  • The paintings Gyeongpodae Pavilion and Chongseokjeong Pavilion were recently donated to the National Museum of Korea and unveiled to the public for the first time at the 2019 special exhibition "Through the Eyes of Joseon Painters: Real Scenery Landscapes of Korea." These two paintings carry significant implications for understanding Joseon art history. Because the fact that they were components of a folding screen produced after a sightseeing tour of the Gwandong regions in 1557 has led to a broadening of our understanding of sixteenth-century landscape painting. This paper explores the art historical meanings of Gyeongpodae Pavilion and Chongseokjeong Pavilion by examining the contents in the two paintings, dating them, analyzing their stylistic characteristics, and comparing them with other works. The production background of Gyeongpodae Pavilion and Chongseokjeong Pavilion can be found in the colophon of Chongseokjeong Pavilion. According to this writing, Sangsanilro, who is presumed to be Park Chung-gan (?-1601) in this paper, and Hong Yeon(?~?) went sightseeing around Geumgangsan Mountain (or Pungaksan Mountain) and the Gwandong region in the spring of 1557, wrote a travelogue, and after some time produced a folding screen depicting several famous scenic spots that they visited. Hong Yeon, whose courtesy name was Deokwon, passed the special civil examination in 1551 and has a record of being active until 1584. Park Chung-gan, whose pen name was Namae, reported the treason of Jeong Yeo-rip in 1589. In recognition of this meritorious deed, he was promoted to the position of Deputy Minister of the Ministry of Punishments, rewarded with the title of first-grade pyeongnan gongsin(meritorious subject who resolved difficulties), and raised to Lord of Sangsan. Based on the colophon to Chongseokjeong Pavilion, I suggest that the two paintings Gyeongpodae Pavilion and Chongseokjeong Pavilion were painted in the late sixteenth century, more specifically after 1557 when Park Chung-gan and Hong Yeon went on their sightseeing trip and after 1571 when Park, who wrote the colophon, was in his 50s or over. The painting style used in depicting the landscapes corresponds to that of the late sixteenth century. The colophon further states that Gyeongpodae Pavilion and Chongseokjeong Pavilion were two paintings of a folding screen. Chongseokjeong Pavilion with its colophon is thought to have been the final panel of this screen. The composition of Gyeongpodae Pavilion recalls the onesided three-layered composition often used in early Joseon landscape paintings in the style of An Gyeon. However, unlike such landscape paintings in the An Gyeon style, Gyeongpodae Pavilion positions and depicts the scenery in a realistic manner. Moreover, diverse perspectives, including a diagonal bird's-eye perspective and frontal perspective, are employed in Gyeongpodae Pavilion to effectively depict the relations among several natural features and the characteristics of the real scenery around Gyeongpodae Pavilion. The shapes of the mountains and the use of moss dots can be also found in Welcoming an Imperial Edict from China and Chinese Envoys at Uisungwan Lodge painted in 1557 and currently housed in the Kyujanggak Institute for Korean Studies at Seoul National University. Furthermore, the application of "cloud-head" texture strokes as well as the texture strokes with short lines and dots used in paintings in the An Gyeon style are transformed into a sense of realism. Compared to the composition of Gyeongpodae Pavilion, which recalls that of traditional Joseon early landscape painting, the composition of Chongseokjeong Pavilion is remarkably unconventional. Stone pillars lined up in layers with the tallest in the center form a triangle. A sense of space is created by dividing the painting into three planes(foreground, middle-ground, and background) and placing the stone pillars in the foreground, Saseonbong Peaks in the middle-ground, and Saseonjeong Pavilion on the cliff in the background. The Saseonbong Peaks in the center occupy an overwhelming proportion of the picture plane. However, the vertical stone pillars fail to form an organic relation and are segmented and flat. The painter of Chongseokjeong Pavilion had not yet developed a three-dimensional or natural spatial perception. The white lower and dark upper portions of the stone pillars emphasize their loftiness. The textures and cracks of the dense stone pillars were rendered by first applying light ink to the surfaces and then adding fine lines in dark ink. Here, the tip of the brush is pressed at an oblique angle and pulled down vertically, which shows an early stage of the development of axe-cut texture strokes. The contrast of black and white and use of vertical texture strokes signal the forthcoming trend toward the Zhe School painting style. Each and every contour and crack on the stone pillars is unique, which indicates an effort to accentuate their actual characteristics. The birds sitting above the stone pillars, waves, and the foam of breaking waves are all vividly described, not simply in repeated brushstrokes. The configuration of natural features shown in the above-mentioned Gyeongpodae Pavilion and Chongseokjeong Pavilion changes in other later paintings of the two scenic spots. In the Gyeongpodae Pavilion, Jukdo Island is depicted in the foreground, Gyeongpoho Lake in the middle-ground, and Gyeongpodae Pavilion and Odaesan Mountain in the background. This composition differs from the typical configuration of other Gyeongpodae Pavilion paintings from the eighteenth century that place Gyeongpodae Pavilion in the foreground and the sea in the upper section. In Chongseokjeong Pavilion, stone pillars are illustrated using a perspective viewing them from the sea, while other paintings depict them while facing upward toward the sea. These changes resulted from the established patterns of compositions used in Jeong Seon(1676~1759) and Kim Hong-do(1745~ after 1806)'s paintings of Gwandong regions. However, the configuration of the sixteenth-century Gyeongpodae Pavilion, which seemed to have no longer been used, was employed again in late Joseon folk paintings such as Gyeongpodae Pavilion in Gangneung. Famous scenic spots in the Gwandong region were painted from early on. According to historical records, they were created by several painters, including Kim Saeng(711~?) from the Goryeo Dynasty and An Gyeon(act. 15th C.) from the early Joseon period, either on a single scroll or over several panels of a folding screen or several leaves of an album. Although many records mention the production of paintings depicting sites around the Gwandong region, there are no other extant examples from this era beyond the paintings of Gyeongpodae Pavilion and Chongseokjeong Pavilion discussed in this paper. These two paintings are thought to be the earliest works depicting the Gwandong regions thus far. Moreover, they hold art historical significance in that they present information on the tradition of producing folding screens on the Gwandong region. In particular, based on the contents of the colophon written for Chongseokjeong Pavilion, the original folding screen is presumed to have consisted of eight panels. This proves that the convention of painting eight views of Gwangdong had been established by the late sixteenth century. All of the existing works mentioned as examples of sixteenth-century real scenery landscape painting show only partial elements of real scenery landscape painting since they were created as depictions of notable social gatherings or as a documentary painting for practical and/or official purposes. However, a primary objective of the paintings of Gyeongpodae Pavilion and Chongseokjeong Pavilion was to portray the ever-changing and striking nature of this real scenery. Moreover, Park Chung-gan wrote a colophon and added a poem on his admiration of the scenery he witnessed during his trip and ruminated over the true character of nature. Thus, unlike other previously known real-scenery landscape paintings, these two are of great significance as examples of real-scenery landscape paintings produced for the simple appreciation of nature. Gyeongpodae Pavilion and Chongseokjeong Pavilion are noteworthy in that they are the earliest remaining examples of the historical tradition of reflecting a sightseeing trip in painting accompanied by poetry. Furthermore, and most importantly, they broaden the understanding of Korean real-scenery landscape painting by presenting varied forms, compositions, and perspectives from sixteenth-century real-scenery landscape paintings that had formerly been unfound.