Earticle

본 연구는 통일신라시대 고선박인 영흥도선 선체 부재의 현 상태를 규명하기 위해, 중앙저판 부재(소나무아속, subgenus Pinus)를 대상으로 미생물 분해 유형과 그 특징을 광학현미경 및 투과형 전자현미경(Transmission electron microscopy, TEM) 관찰을 통해 조사하였다. 외곽 부위와 중앙 부 위에서 각각 시료를 채취하여 비교한 결과, 두 부위 모두에서 세균(bacteria)에 의한 분해 피해가 주요하게 관찰되었으며, 외곽 부위의 분해 피해가 중앙 부위보다 상대적으로 심하게 나타났다. 일부 축방향가도관(axial tracheid)에서는 2차벽에 동공(cavity)을 형성하는 Type-I 연부후(soft rot)가 관찰 되었으나, 그 빈도는 매우 낮았다. TEM 관찰 결과, 축방향가도관에서의 세균 피해는 주로 침식형 분해 세균(erosion bacteria)에 의한 것으로 확인되었으며, 동굴형 분해 세균(tunneling bacteria)과 연 부후균에 의한 피해는 일부에서만 제한적으로 나타났다. 방사조직(ray)을 구성하는 방사가도관(ray tracheid)에서는 침식형 및 동굴형 분해 세균, 연부후균 피해가 모두 관찰되었으나 방사유세포(ray parenchyma cell)에서는 침식형 분해 세균 피해만이 확인되었다. 전반적으로 방사가도관은 축방향가 도관 및 방사유세포에 비해 높은 부후저항성을 나타내었다. 또한 유연벽공 및 교분야벽공의 벽공막 (pit membrane)은 인접한 세포벽에 비해 미생물 분해에 대한 저항성이 높게 나타났다. 이러한 결과는 영흥도선 선채 부재의 미생물학적 열화 양상 및 현 보존 상태를 이해하는 데 기초 자료로 활용될 수 있으며, 향후 체계적인 보존 전략 수립에도 이바지할 수 있을 것이다.

To evaluate the preservation state of the Yeongheungdo-sun’s hull wood, an ancient shipwreck from the Unified Silla period, the types and characteristics of microbial decay in the central bottom board (subgenus Pinus) were examined using light microscopy and transmission electron microscopy (TEM). Samples from the outer and central regions revealed bacterial decay as the predominant form in both areas, with slightly more severe degradation in the outer region. In some axial tracheids, Type-I soft rot, characterized by cavity formation in secondary cell walls, was observed alongside erosion bacterial decay, although it occurred infrequently. TEM confirmed that bacterial degradation was primarily caused by erosion bacteria, whereas tunneling bacteria and soft rot fungi occurred only in a few axial tracheids. In ray tissue, ray tracheids exhibited all three types of microbial decay, similar to axial tracheids, whereas ray parenchyma cells showed only erosion bacterial decay. Overall, ray tracheids were more resistant to microbial degradation than axial tracheids and ray parenchyma cells, and pit membranes generally displayed greater resistance than adjacent cell walls. These findings provide essential data for understanding microbial degradation and the preservation state of Yeongheungdo-sun’s hull wood, supporting the development of future conservation strategies

심희수 초상화 2점의 채색 안료에 대한 분석과 현미경 관찰을 통해 채색 안료의 특성을 조사하였으며 비파괴분석 결과와 비교 검토하였다. 심희수 초상화에 사용된 안료는 색상에 따라 유사한 안료를 사용한 것으로 확인되었다. 적색 안료는 진사/주, 연단을 사용하였으며, 청색 안료는 석청, 녹색 안료는 녹염동광, 백색 안료는 연백을 사용한 것으로 확인되었다. 또한 유사한 형식으로 제작된 17~18세기 조선시대 관복초상화 6점과의 채색 안료를 비교한 결과 제작 시기에 따라 차이를 보였다. 적색 안료의 경우 18세기에 제작된 초상화에서 산화철 계통의 안료가 추가적으로 사용된 특징을 보인다. 청색 안료의 차이점은 18세기 초반까지 사용되지 않았던 회청 안료가 18세기 후반에 제작된 초상화에서 확인된 점이다.

This study analyzed the pigments used in two portraits of Sim Hui-su using scanning electron microscopy/energy dispersive spectroscopy(SEM/EDS), X-ray diffraction(XRD) analysis, and microscopic observation, and then compared the results to those from nondestructive analysis. It was estimated that cinnabar/vermilion and minium were used for the red pigment, azurite for the blue pigment, atacamite for the green pigment, and lead white for the white pigment. These results were compared to the pigments of six portraits with a similar format, full-length official-attire portraits from the 17-18th century Joseon period. It was revealed that the composition of the pigments used in the portraits varied depending on the date of production. Iron oxide, another red pigment, was used in the 18th century. As for the blue colorant, smalt was used in the late 18th century, whereas it was absent until the early 18th century.

Confocal scanning microscopy is a measurement technique used to observe micrometer and sub-micrometer features due to its high resolution, nondestructive properties, and 3D surface profiling capabilities. The design, implementation, and performance test of a confocal scanning microscopy system are presented in this paper. A short-wavelength laser (405 nm) and an objective lens with a high numerical aperture (0.95) were used to achieve the desired high resolution, while the x- and y-axis scans were implemented using an acousto-optic deflector and galvanomirror, respectively. An objective lens with a piezo-actuator was used to scan the z-axis. A spatial resolution of less than 138 nm was achieved, along with successful 3D surface reconstructions.

We propose a single-shot digital holographic microscopy based on computational telecentricity with a single-arm off-axis interferometer (SA-OAI), which is composed of optical recording, computational compensation and retrieving processes. In the optical recording, the object beam is recorded as a hologram pattern with the SA-OAI, where a tube lens is located at the slightly shorter distance than its focal length from the objective lens. Another additional quadratic phase factor (AQPF) is then generated and embedded into the recorded hologram. In the computational compensation process, however, this AQPF can be cancelled out from the recorded hologram with its digitally-generated version, which enables the proposed system operating in a so-called computational telecentricity. Thus, in the numerical retrieving process, phase information of the test object can be reconstructed just from this AQPF-compensated hologram. Wave-optical analysis and experiments with a test half-ball lens confirm the feasibility of the proposed system in the practical application.

This paper proposes a new spatial filtering approach for increasing the depth-of-field (DOF) of imaging systems, which is very useful for obtaining sharp images for a wide range of axial positions of the object. Many different techniques have been reported to increase the depth of field. However the main advantage in our method is its simplicity, since we propose the use of purely absorbing beam-shaping elements, which allows a high focal depth with a minimum modification of the optical architecture. In the filter design, we have used the analogy between the axial behavior of a system with spherical aberration and the transverse impulse response of a 1D defocused system. This allowed us the design of a ring-shaded filter. Finally, experimental verification of the theoretical statements is also provided.

In a scanning electron microscope (SEM), outside acoustic noise causes image noise that distorts observations of the specimen being examined. A SEM that is less sensitive to acoustic noise is highly desirable. This paper investigates the image noise problem by addressing the mode shapes of the base plate and the transmission path of the acoustic noise and vibration. By arranging the position of the rib, a new SEM base plate was developed that had twisting as the 1st and 2nd modes. In those two twisting modes, vibration nodes existed near the center of the base plate where the specimen chamber is placed. Less vibration was transmitted to the chamber and to the specimen by the twisting modes compared to bending ones, which are the 2nd and 3rd modes for a rectangular plain base plate. An SEM with the developed base plate installed exhibited a significant reduction of image noise when exposed to acoustic noises below 250 Hz.

Digital holographic microscopy (DHM) is a three-dimensional (3D) imaging technique that uses the phase information of coherent light. In the reconstruction process of DHM, a narrow region around the positive or negative sideband from the Fourier domain is windowed to avoid noise due to the DC spectrum of the hologram spectrum. However, the limited size of the window also degrades the high-frequency information of the 3D object profile. Although a large window can have more detailed information of the 3D object shape, the noise is increased. To solve this trade-off, we propose phase difference averaging (PDA). The proposed method yields high-frequency information of the specimen while reducing the DC noise. In this paper, we explain the reconstruction algorithm for this method and compare it to various conventional filtering methods including Gaussian, Wiener, average, median, and bilateral filtering methods.

OBJECTIVES : In this study, microstructural components of crumb rubber modified asphalt (CRMA) binder were investigated using environmental scanning electron microscope (ESEM). To clearly understand the elemental composition of the CRMA binder, energy dispersive X-ray spectroscopy (EDX) was employed on the ESEM samples. METHODS : CRMA binders were produced using open blade mixers at $177^{\circ}C$ for 30 min. The binders were artificially aged through a series of accelerated aging processes. Sample preparation was done by making a mold shape on the glass slide. Thereafter, the morphology of the CRMA binder was observed using the ESEM coupled with the EDX. RESULTS : The images captured from the ESEM indicate that the unaged CRMA binder appears to have a single-phase continuous nonuniform structure after the addition of crumb rubber particles, whereas the artificially aged CRMA binder was observed to have two different phases. ESEM coupled with EDX shows detailed internal structure of the modified binders compared to other technologies (i.e., optical microscopy, atomic force microscopy, and conventional scanning electron microscope). CONCLUSIONS : The captured images resemble the internal structures such as the viscous properties of the unaged CRMA binder and the interaction between the rubber particles and the base binder at aged condition. ESEM is a powerful instrument and with the introduction of EDX, it provided more details of the network microstructure of the asphalt binder. ESEM coupled with EDX is recommended for use in future investigation of microstructure of asphalt binders.

We studied the distribution of the current density and its magnetic-field dependence in GdBCO coated conductors with AC bias currents using low temperature scanning Hall probe microscopy. We selectively measured magnetic field profiles from AC signal obtained by Lock-in technique and calculated current distributions by inversion calculation. In order to confirm the AC measurement results, we applied DC current corresponding to RMS value of AC current and compared distribution of AC and DC transport current. We carried out the same measurements at various external DC magnetic fields, and investigated field dependence of AC current distribution. We notice that the AC current distribution unaffected by external magnetic fields and preserved their own path on the contrary to DC current.

The storing ability of information of optical disks directly depends on the physical property of recording unit cells. It means that the degradation of optical disks ultimately causes the loss of the physical and chemical properties of recording unit cells and leads also information, too. We investigated the degradation and life time of optical disks which tell us the longevity of the preservation of information. Optical disks were aged using the accelerated aging system and studied by optical reflectivity spectroscopy and atomic force microscopy(AFM), and the preservation environment of electronic media in National central library of Korea also were analysed. Results show that the double reflective coated optical disks have good preservation of recording information but revealed some deformation of dye area in the AFM images. It means that we should include the mechanical and chemical degradation of the optical disks in the life time expectation evaluation.

We demonstrate the operation of an apparatus that we call the laser scanning confocal microscopy. It is valuable tool of the investigations for imaging process. We measured the thin metal structure through the SCM manufacture. Confocal microscopy offers several advantages including shallow depth of field, elimination of out-of-focus glare, and the ability to collect serial optical sections from thick specimens than conventional optical microscope. This research is manufactured of scanning confocal microscopy and after measured of metal materials structure.

This study utilized scanning electron microscopy (SEM) to analyze the morphological characteristics of hair cut by various methods. In forensic investigations, hair serves as crucial evidence. When the hair root is present, DNA analysis can be employed for individual identification. However, when hair is cut in the middle, DNA analysis becomes challenging, making the morphological analysis of cut marks an essential aspect of forensic examinations. In this study, hair samples were cut using various tools, including a scalpel, utility knife, and scissors. SEM images were then obtained, and the morphological differences between tool-cut hair and hair severed by tensile force were compared and analyzed. The results indicated that tool-cut hair exhibited distinct striation marks on the cross-section, with the cuticle layer shifting in the direction of tool insertion, leaving scratch-like marks. In contrast, hair that was forcibly pulled apart showed no tool marks and displayed an irregular fracture pattern. These findings contribute to the quantitative and qualitative assessment of hair cut marks in forensic investigations and provide fundamental data for expanding the application of morphological hair analysis in criminal cases.