• Journal of the Korean Wood Science and Technology
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• 제51권2호
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• pp.69-80
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• 2023

This study conducted scientific analyses on eight objects of wooden lacquerware to understand the manufacturing techniques of wooden lacquerware in the late Joseon Dynasty. The results of lacquer layer analysis with a microscope and scanning electron microscopy-energy dispersive X-ray spectrometry revealed that most samples were composed of 1-3 lacquer layers. Moreover, a red-colored layer was found to be red ocher and cinnabar, and Fourier-transform infrared spectroscopy analysis was carried out to determine the components of the lacquer layer. The detected components were mostly lacquer and partially cashew shell nut liquid.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 가을 학술논문 발표대회
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• pp.170-171
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• 2021

This study compared the characteristics of the newly established JISA 5011-5 coal gasification slag fine aggregate with the characteristics of CGS generated in Korean IGCC through microscopic analysis. As a result of the study, similar results to K_CGS and J_CGS were found

• Applied Microscopy
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• 제30권3호
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• pp.285-293
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• 2000

임신중에 투여된 불소가 흰쥐태아의 법랑질형성에 미치는 영향을 알아보고자 어미흰쥐에게 불소를 음용 시킨 후, 생후 11일이 경과된 어린 흰쥐를 희생하였다. 이후, 하악절치를 발치한 후, 법랑단백질의 종류 및 양적 변화와 법랑질 표면의 형태학적 변화를 관찰하였다. 분비법랑질과 성숙법랑질에서 추출한 법랑단백질을 전기 영동한 결과, 분비법량질에서는 분자량 $22\sim24kDa$의 amelogenin이 확인되었는데, 대조군에서보다 불소투여 농도가 높아질수록 양이 감소하였다. 성숙법랑질에서는 분자량이 68kDa의 enamelin이 확인되었으며, 대조군에 비해 불소투여 농도가 높을수록 양적인 증가가 확인되었다. 그리고 주사전자현미경을 사용하여 법랑질 표면을 관찰한 결과, 대조군에서는 평탄하고 매끄러운 표면인 반면에 불소투여군은 거친 표면과 균열이 심하게 나타났고, 불규칙한 소공이 관찰되었다. 그리고 일부에서는 균열과 함께 주머니 같은 결절과 법랑질 형성부전을 확인하였다. 따라서 본 연구결과, 태아발생과정 중 투여된 불소가 법랑질형성에 관여하는 법랑모세포에 영향을 줌으로써 단백질의 형성과 분비가 지연 또는 억제되며, 수분과 단백질 제거에 관여하는 법랑모세포의 기능을 저하시키는 것으로 사료된다. 이러한 단백질의 비정상적인 형성과 분비는 법랑질 형성부전 등의 법랑질형성에 전반적으로 영향을 미치는 것으로 확인되었다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제33권4호
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• pp.340-349
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• 2007

Free flap transplantation with microvascular anastomosis has been successfully performed by development of surgical technique, materials and postoperative monitoring equipments of flap. But success rate of microvascular anastomosis is influenced by various factors, and failure rate is about 5-10%. The most influential factor for success rate is surgical technique and other factors that influence failure of microvascular anastomosis are ischemic time of free flap, thrombus formation of anastomosis region and vascular spasm. In this study, vascular patency and thrombus formation in experimental micro-venous anastomosis, and endothelial repair were observed with histologic analysis, scanning electron microscopy, transmission electron microscopic examination. The results were obtained as follows: 1. In vascular patency test in 30 minute and 7 days after micro-venous anastomosis with heparin irrigation, all of 12 anastomosis site were good vascular patency. 2. In thrombus formation in 2 weeks group(Experimental I), 2 site of 6 cases were observed thrombus, and in 4 weeks group(Experimental II), 1 site of 6 cases were observed thrombus. 3. In histologic examination, normal vein(Control Group) showed continued internal elastic lamina, well formed thick smooth muscle layer and connective tissue. The group of 2 weeks after microvenous anastomosis(Experimental I) showd locally recovered internal lamina, discontinued internal lamina, disorganized smooth muscle cells and granulation tissue around suture silk. In the group of 4 weeks after micro-venous anastomosis(Experimental II), anastomosis site showed almostly continued internal lamina, disorganized smooth muscle cells and cicartrized tissue around suture silk. 4. In scanning electron microscope examination in 2 weeks(Experimental I) after micro-venous anastomosis, mesh fibrin formation showed near to endothelial cells, and in 4 weeks after micro-venous anastomosis(EXperimental II), numerous blood cells and fibrin mesh formation was seen associated with irregular endothelial cell arrangement. 5. In transmission electron microscope examination in 2 weeks after micro-venous anastomosis(Experimental I), irregular arrangement of smooth muscle cells was seen adjacent to collagenized tissue around suture silk. In 4 weeks after micro-venous anastomosis(Experimental II), denuded venous wall composed of relatively well arranged smooth muscle cells was covered by endothelial cells, but fibroblast cells and foreign body giant cells near to suture silk was remained. From the results obtained in this study, results of good vascular patiency and anti-thrombotic effect of heparin were obtained as a local irrigation solution, and repair of venous endothelial cell was observed in 2 weeks after micro-venous anastomosis.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제32권2호
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• pp.117-128
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• 2006

Free flap transplantation with microvascular anastomosis has been successfully performed by development of surgical technique, materials and postoperative monitoring equipments of flap. But success rate of microvascular anastomosis is influenced by various factors, and failure rate is about 5-10%. The most influential factor for success rate is surgical technique and other factors that influence failure of microvascular anastomosis are ischemic time of free flap, thrombus formation of anastomosis region and vascular spasm. Many studies has been published in microvascular anastomosis with histologic effect for irrigating solution. But local irrigation solution has been used clinically in microvascular anastomosis, the comparison with each solution, microhistological study for endothelial cell repair and vascular patency has not been reported. The heparin which is anti-thrombotic agent, and urokinase which is fibrinolytic agent are used for this study. Vascular patency and thrombus formation in experimental micro-arterial anastomosis, and endothelial repair were observed with histologic analysis, scanning electron microscopy, transmission electron microscopic examination. The results were obtained as follows: 1. In vascular patency test in 30 minute and 7 days after micro-arterial anastomosis, equal effects of good vascular patency were obtained in group of local irrigation with heparin and urokinase. 2. In thrombus formation in 7 days after micro-arterial anastomosis, equal effects of minimal thrombus formation were obtained in group of local irrigation with heparin and urokinase. 3. In toluidin blue staining in 7 days after micro-arterial anastomosis, local destruction of endothelial cell and inner elastic lamina were seen and endothelial repair was not seen. 4. In scanning electron microscope examination in 7 days after micro-arterial anastomosis, endothelial cell was not seen in peripheral to suture materials, thrombus associated fibrin network was observed. 5. In transmission electron microscope examination in 7 days after micro-arterial anastomosis, inflammatory cell was seen within smooth muscle cells in site of endothelial cell destruction, smooth muscle cell around suture material were arranged irregularly, some collagenous change were seen. From the results obtained in this study, same results of good vascular patency and anti-thrombotic effect of heparin and urokinase were obtained as a local irrigation solution, and repair of endothelial cell was not seen in 7 days after micro-arterial anastomosis.

• 한국인터넷방송통신학회논문지
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• 제14권5호
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• pp.215-221
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• 2014

본 논문에서는 RF 고전력 스트레스에 의한 SAW 디바이스의 신뢰성 분석을 위하여 향상된 내전력 시험시스템 및 시험방법을 제안하고 고장분석을 통해 고장메카니즘을 분석하였다. 광학현미경, SEM(Scanning Electron Microscope) 및 EDX(Energy Dispersive X-ray Spectro-scopy)장비를 이용하여 고장 분석한 결과, SAW 디바이스의 고장메카니즘은 고전류 밀도 및 고온 조건에서 줄열에 의한 Electromigration으로 분석하였다. Electromigration은 IDT전극에 void와 hillock을 생성하고, 그 결과로 전극이 단락과 단선되어 삽입손실이 증가하는 것이다. 제안된 내전력 시험시스템과 방법을 이용하여 450MHz CDMA용 SAW 필터의 가속수명시험을 수행하고, 아이링 모델과 와이블 분포를 이용하여 SAW 필터의 $B_{10}$수명은 98,500시간으로 추정하였다.

• 한국재료학회지
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• 제31권12호
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• pp.665-671
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• 2021

A 1.8 ㎛ thick polycrystalline diamond (PCD) thin film layer is prepared on a Si(100) substrate using hot-filament chemical vapor deposition. Thereafter, its thermal conductivity is measured using the conventional laser flash analysis (LFA) method, a LaserPIT-M2 instrument, and the newly proposed light source thermal analysis (LSTA) method. The LSTA method measures the thermal conductivity of the prepared PCD thin film layer using an ultraviolet (UV) lamp with a wavelength of 395 nm as the heat source and a thermocouple installed at a specific distance. In addition, the microstructure and quality of the prepared PCD thin films are evaluated using an optical microscope, a field emission scanning electron microscope, and a micro-Raman spectroscope. The LFA, LaserPIT-M2, and LSTA determine the thermal conductivities of the PCD thin films, which are 1.7, 1430, and 213.43 W/(m·K), respectively, indicating that the LFA method and LaserPIT-M2 are prone to errors. Considering the grain size of PCD, we conclude that the LSTA method is the most reliable one for determining the thermal conductivity of the fabricated PCD thin film layers. Therefore, the proposed LSTA method presents significant potential for the accurate and reliable measurement of the thermal conductivity of PCD thin films.

• 한국광물학회지
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• 제5권1호
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• pp.42-47
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• 1992

해남 성산광산에서 산출되는 명반석에서 나타나는 진동누대구조를 back-scattered electron(BSE) 상과 전자현미분석기를 이용하여 연구하였다. 이런 누대구조는 편광현미경 하에서는 관찰되지 않자만, BSE상에서는 아주 명확히 관찰된다. 전자현미분석에 의하면 이런 누대구조는 명반석 구조 내 A 자리에서 칼륨을 치환하는 나트륨의 양적인 차이에 의하여 생긴다는 것을 지시한다. BSE상에서 밝기가 증가함에 따라 칼륨의 양은 증가하지만, 나트륨의 양은 감소한다. 섬세한 작은 규모의 누대구조와 인접한 zone사이의 명확한 경계는 이런 진동누대구조가 성장하는 명반석 결정주변의 열수용액의 성분의 변화에 기인하여 형성된 것임을 가리킨다. 이러한 변화를 초래한 요인은 1) 유입되는 유체 성분의 변화 및 2) 보다 안정한, 나트륨이 적은 명반석의 따른 침전에 의한 용액성분의 변화일 것으로 생각된다.

• 한국패류학회지
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• 제27권1호
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• pp.55-65
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• 2011

Some characteristics of germ cell differntiations during spermiogenesis and mature sperm ultrastructure in male Phacosoma japonicus were investigated by transmission electron microscope observations. The morphology of the spermatozoon of this species has a primitive type and is similar to those of other species in the subclass Heterodonta. Morphologies of the sperm nucleus and the acrosome of this species are the cylindrical type and cap shape, respectively. The spermatozoon is approximately 45-50 ${\mu}m$ in length, including a long curved sperm nucleus (about $3.70{\mu}m$ long with 45 $^{\circ}$ of the angle of the nucleus, an acrosome (about $0.55{\mu}m$ in length), and tail flagellum (about 42-$47{\mu}m$)The axoneme of the sperm tail shows a 9+2 structure. As some characteristics of the acrosomal vesicle structures, the basal and lateral parts of basal rings show electron opaque part (region), while the anterior apex part of the acrosomal vesicle shows electron lucent part (region). These characteristics of the acrosomal vesicle were found in the family Veneridae and other several families in the subclass Heterodonta. These common characteristics of the acrosomal vesicle in the subclass Heterodonta can be used for phylogenetic and systematic analysis as a taxonomic key or a significant tool. The number of mitochondria in the sperm midpiece of this species are four, as one of common characteristics appear in most species in the family Veneridae and other families in the subclass Heterodonta. However, exceptionally, only three species in Veneridae of the subclass Heterodonta contain 5 mitochondria. The number of mitochondria in the sperm midpiece can be used for the taxonomic analysis of the family or superfamily levels as a systematic key or tools.

• 한국패류학회지
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• 제27권2호
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• pp.121-129
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• 2011

The ultrastructural characteristics of germ cell development during spermatogenesis and mature sperm morphology of in male Scapharca subcrenata were investigated by transmission electron microscope observation. Spermatogonia are located nearest the outer wall of the acinus, while spermatocytes and spermatids are positioned near the accessory cells. The accessory cells, which is in close contact with developing germ cells, contained a large quantity of glycogen particles and lipid droplets in the cytoplasm. Therefore, it is assumed that they are involved in supplying of the nutrients for germ cell development. The morphologies of the sperm nucleus and the acrosome of this species are the oval shape and cone shape, respectively. Spermatozoa are approximately 45-$50{\mu}m$ in length including a sperm nucleus (about $1.30{\mu}m$ in length), an acrosome (about $0.59{\mu}m$ in length), and tail flagellum (about 43-$47{\mu}m$). The axoneme of the sperm tail shows a 9 + 2 structure. As some characteristics of the acrosomal vesicle structures, the right and left basal rings show electron opaque part (region), and also the anterior apex part of the acrosomal vesicle shows electron opaque part (region). These characteristics of the acrosomal vesicle were found in Acinidae and other several families in subclass Pteriomorphia. These common characteristics of the acrosomal vesicle in subclass Pteriomorphia can be used for phylogenetic and taxonomic analysis as a taxonomic key or a significant tool. The number of mitochondria in the midpiece of the sperm of this species are five, as one of common characteristics appear in most species in Arcidae and other families in subclass Pteriomorphia. The acrosomal vesicles of Arcidae species do not contain the axial rod and several transverse bands in acrosome, unlkely as seen in Ostreidae species in subclass Pteriomorphia, These characteristics can be used for the taxonomic analysis of the family or superfamily levels as a systematic key or tools.