低周波 電磁場 속에서 불활성 기체 원자에 의한 電子의 산란단면적

정경복,장차익,최승평 조선대학교 기초과학연구소 1997 自然科學硏究 Vol.20 No.1

The scattering cross section is the physical quantity which is susceptible of a reasonably direct experimental measurement and which at the same time lends itself readily to calculation, and which establish contact between scattering theory and scattering experiment to assist each other. We have calculated one-photon free-free absorption cross sections without target distortion at the frequencies of the CO_2, Nd, and ruby lasers, for targets consisting of the ground states of He, Ne, Ar. The calculations yield total cross sections averaged over all orientations of the polarzation, which is taken to be linear. Electron energies are in the range up to about 13 eV. The atomic potential used to represent the interaction of the atom in our calculation is the same one that is replaced atom by the potential used by Robinsion and Geltman in the evaluation of photodetachment cross-sections. We used the Numerov method for numerical integration of our differential equations. This method appears to be most efficient numerical intergration scheme available for second-order differential equations with the first derivative absent.

라만분광학의 바이오메디컬 응용

정경복 한국물리학회 2017 새물리 Vol.67 No.6

Raman spectroscopy has attracted great interest as a powerful analytical tool that can be used to detect changes in the structure and the composition of biological samples (cells, tissues, biofluids, etc.) at the molecular level. Its high sensitivity and specificity, a small amount of sample preparation, and non- or minimally-invasive use have recently led to an increase in the number of biomedical applications of Raman spectroscopy. This paper reviews the recent biomedical applications of Raman spectroscopy, which are considered to be multi-functional and powerful toolkits for probing the biochemical properties of biomedical samples in medical science. The basic principles of Raman spectroscopy and surface-enhanced Raman scattering (SERS) are briefly introduced. Furthermore, the biomedical applications of Raman spectroscopy, including diagnostic assessment (orthodontic tooth movement), pharmacotherapy (antibiotic effect, cytotoxicity of tissue adhesive), medical device therapy (collagen cross-linking treatment for the restrain of progressive myopia), and finally in-vivo Raman diagnosis, are described. 라만 분광법은 분자수준에서 바이오 샘플 (세포, 조직, 체액 등)의 구조 및 조성 변화를 감지하는데 사용할 수 있는 강력한 분석 도구로써 매우 큰 관심을 모으고 있다. 높은 민감도와 특이성, 적은 양의 샘플준비, 비침습성 방법은 최근 라만 분광학의 바이오메디칼 응용의 증가로 이어졌다. 본 논문에서는 바이오 샘플의 생화학적 특성을 조사하기 위하여 다기능적이고 강력한 툴킷으로 간주되는 라만 분광학의 바이오메디칼 응용을 리뷰하였다. 라만 분광법과 표면증강라만산란 (surface enhanced Raman scattering, SERS)의 기본 원리를 소개하였고, 이를 이용한 바이오메디칼 응용: 진단 (치아교정 과정에서의 치아이동), 약물평가 (항생제 효과, 생체접착제의 세포 독성) 및 의료기기 요법 (근시 억제를 위한 콜라겐 교차 결합 치료), 라만진단 등의 라만분광학의 다양한 바이오메디칼 응용을 논하였다.

Physicochemical and surface properties of acrylic intraocular lenses and their clinical significance

정경복,진경현,박헌국 한국약제학회 2017 Journal of Pharmaceutical Investigation Vol.47 No.5

To analyze and compare several commercially available acrylic intraocular lenses (IOLs) with particular regard to their clinical significance, we examined the physicochemical and surface properties of four currently available acrylic IOLs using static water contact angle, atomic force microscopy (AFM), Raman spectroscopy, and differential scanning calorimetry (DSC) measurements. The hydrophobic acrylic IOLs, ZA9003, and MA60BM, had contact angles ranging from 77.9° ± 0.65° to 84.4° ± 0.09°. The contact angles in the hydrophilic acrylic (970C) and heparin-surface-modified (HSM) hydrophilic acrylic IOLs (BioVue) were 61.8° ± 0.45° and 69.7° ± 0.76°, respectively. The roughness of the IOL optic surface differed depending on the type of IOL (p < 0.001). The surface roughness of BioVue had the lowest value: 5.87 ± 1.26 nm. This suggests that the BioVue IOL may lead to reduced cellular adhesion compared to the unmodified IOLs. All IOLs including those composed of acrylic optic materials from different manufacturers showed distinct Raman spectra peaks. The glass transition temperatures ( Tg) for the hydrophobic acrylic IOLs were between 12.5 and 13.8 °C. These results suggest that the intraoperative and postoperative behavior of an IOL can be predicted. This information is also expected to contribute greatly to the industrial production of reliable biocompatible IOLs.

Label-free Noninvasive Characterization of Osteoclast Differentiation Using Raman Spectroscopy Coupled with Multivariate Analysis

정경복,강인순,이영주,김도현,박헌국,이기자,김채균 한국광학회 2017 Current Optics and Photonics Vol.1 No.4

Multinucleated bone resorptive osteoclasts differentiate from bone marrow-derived monocyte/macrophageprecursor cells. During osteoclast differentiation, mononuclear pre-osteoclasts change their morphology andbiochemical characteristics. In this study, Raman spectroscopy with multivariate techniques such asPrincipal Component Analysis (PCA) and Linear Discriminant Analysis (LDA) were used to extractbiochemical information related to various cellular events during osteoclastogenesis. This technique allowedfor label-free and noninvasive monitoring of differentiating cells, and clearly discriminated four differenttime points during osteoclast differentiation. The Raman band intensity showed significant time-dependentchanges that increased up to day 4. The results of Raman spectroscopy agreed with results from atomicforce microscopy (AFM) and tartrate-resistant acid phosphatase (TRAP) staining, a conventional biologicalassay. Under AFM, normal spindle-like mononuclear pre-osteoclasts became round and smaller at day 2after treatment with a receptor activator of nuclear factor-κB ligand and they formed multinucleated giantcells at day 4. Thus, Raman spectroscopy, in combination with PCA-LDA, may be useful for noninvasivelabel-free quality assessment of cell status during osteoclast differentiation, enabling more efficientoptimization of the bioprocesses.

Types of Polyunsaturated Fatty Acids in Epididymal Adipose Tissue Are Distinguishable Using Raman Spectroscopy and Multivariate Analysis

정경복,김도현,신의철,하정헌 한국식품영양과학회 2023 Journal of medicinal food Vol.26 No.5

Biological polyunsaturated fatty acids (PUFAs) are important precursors of secondary messengers that modulate inflammatory responses, cellular growth, and cholesterol metabolism. The optimal n-6/n-3 ratio is extremely important for maintaining normal homeostasis because n-3 and n-6 PUFAs are competitively metabolized. To date, a widely accepted analytical method to determine the biological n-6/n-3 ratio is gas chromatography-mass spectrometry (GC-MS) on dried whole blood samples. However, this technique has several drawbacks, including the intrusive nature of collecting blood samples, high expenses involved, and length of time required to use the GC/MS instrument. To overcome these limitations, we introduced Raman spectroscopy (RS) to distinguish PUFAs present in the epididymal adipose tissue (EAT) isolated from experimental rats that were fed three different high-fat diets (HFDs) with multivariate analysis, including principal component analysis (PCA) and linear discriminant analysis (LDA). The diets comprised HFD, HFD + perilla oil (HFD + PO [n-3 rich oil]), and HFD + corn oil (HFD + CO [n-6 rich oil]). This method allows for quantitative, label-free, noninvasive, and rapid monitoring of biochemical changes in the EAT with high sensitivity. In RS, the Raman bands of the EAT from three different diet groups (HFD, HFD + PO, and HFD + CO) detected and distinguished peaks at 1079 (C–C stretching vibration), 1300 (CH2 deformation), 1439 (CH2 deformation), 1654 (amide I), 1746 (C = O stretching vibration), and 2879 cm−1 (–C–H stretching vibration). The PCA-LDA analysis results showed that PUFAs in the EAT of animals receiving the three different dietary interventions can be determined according to the three groups (HFD, HFD + PO, and HFD + CO). In conclusion, we investigated the possibility of determining PUFA profiles in specimens using RS.

패션페인팅(Fashion Painting)을 이용한 의상디자인 연구

정경복 ( Kyung Bock Jung ),이정희 ( Jung Hi Rhee ) 복식문화학회 2010 服飾文化硏究 Vol.18 No.1

패션페인팅(Fashion Painting)을 이용한 의상디자인 연구

정경복,이정희 복식문화학회 2010 服飾文化硏究 Vol.18 No.1

In modern society as people adapt to social and cultural changes, people prefer high-scarcity designed products rather than standardized ones. Consequently, this adaptation lays a foundation in art and cultural domains to express uniqueness and individuality. The purpose of this study is to develop fashion designs by fusing fashion painting and handicraft techniques through creative and various artistic expressions. The researchers studied the sociocultural background of modern handicraft fashion using document-based research methods. Based on the characteristics of modern handicraft, we produced six garments that applied fashion painting techniques. In this study, the origin of fashion painting was found in ornaments such as tattoo or body-painting. We determined that modern designers were using various fashion painting techniques and motives as unique and advanced ornamentary skills. Harmonizing various handicraft techniques(dyeing, embroidery, quilt, patchwork, beads, fashion painting, etc.) centered on fashion painting enabled creation of unique fashion design through varieties of artistic expressions.

Eu3+ 농도 및 열처리 온도에 따른 CaTiO3: Eu3+ 페로브스카이트 형광체 분말의 광학적 특성

김다영,정경복 한국물리학회 2022 새물리 Vol.72 No.7

The Eu3+-doped CaTiO3 (CaTiO3:Eu3+) perovskite phosphorus powders were synthesized using high-energy ball-milling (HEBM). Their crystal structure, surface morphology, and photoluminescence properties were investigated as a function of the europium concentration and annealing temperature. The X-ray diffraction (XRD) peaks of the CaTiO3:Eu3+ powders were good matches with the standard XRD peaks of the orthorhombic CaTiO3 phase without impurities. The field emission scanning electron microscopy (FE-SEM) images of CaTiO3:Eu3+ powders show that the particles increased in size and agglomerated as the annealing temperature increased. The Fourier transform infrared (FT-IR) spectrum confirmed that the absorption bands of CaTiO3:Eu3+ and CaTiO3 were in good agreement, which confirmed that Eu3+ ions were effectively doped into CaTiO3. The highest photoluminescence (PL) emission intensity was observed at an annealing temperature of 1200 °C and a Eu3+ concentration of 6 mol%. The PL spectra showed the strong characteristic peak at 614 nm of the 5D0 → 7F2 electric dipole transition of Eu3+ at an excitation wavelength of 398 nm. These results suggest that the PL emission intensity of CaTiO3:Eu3+ perovskite phosphorus powder can be controlled by Eu3+ concentration and annealing temperature. Eu3+이 첨가된 CaTiO3 페로브스카이트 형광체 분말을 고에너지 볼밀링 (high-energy ball-milling; HEBM) 방법을 이용하여 상온에서 합성하였으며, Eu3+의 농도 변화 및 열처리 온도 변화에 따른 형광체의 결정구조, 표면형상, 발광특성을 분석하였다. X-선 회절 패턴을 분석한 결과 합성한 CaTiO3:Eu3+ 페로브스카이트 형광체는 CaTiO3와 동일한 사방정계 (orthorhombic)의 결정성을 보였다. 전계방사형 주사전자현미경 (FE-SEM)을 통하여 열처리 온도가 증가함에 따라 입자의 크기가 커지고 응집되는 것을 확인할 수 있었다. CaTiO3:Eu3+ 페로브스카이트 형광체 분말은 Eu3+ 농도 6 mol%, 열처리 온도 1200~°C에서 가장 강한 발광 특성이 나타났으며, 여기 파장 398 nm에서 Eu3+의 5D0 → 7F2 (614 nm) 전기 쌍극자 전이에 의한 적색의 최대 발광 스펙트럼을 보였다. 본 연구를 통하여 Eu3+의 농도 변화와 열처리 온도 변화를 조절함으로써 CaTiO3:Eu3+ 페로브스카이트 형광체 분말의 적색 발광의 세기를 제어할 수 있음을 보았다.

Effects of Pr Concentration and Annealing Temperature on the Structural and Optical Properties of Y2O3:Pr3+ Nanopowders by High-energy Ball-milling

조기표,정경복 한국물리학회 2021 New Physics: Sae Mulli Vol.71 No.7

Pr3+-doped Y2O3 powders were synthesized using high-energy ball milling. Their structural and photoluminescence properties were investigated as functions of the concentration of the praseodymium and the annealing temperatures. The X-ray diffraction peaks of the Y2O3:Pr3+ powders matched the standard X-ray diffraction(XRD) peaks of the cubic Y2O3 phase without impurities well. The intensity of the XRD peak increased with increasing annealing temperature, as did the photoluminescence emission intensity. These results indicate that the crystallinity of the powder improved with increasng annealing temperature. The highest PL emission intensity was observed at an annealing temperature of 1200 ◦C and Pr3+ concentration of 0.1 mol%. The PL spectra showed characteristic peaks at 618 (3P0 ! 3H6), 630 (2D1 ! 3H4), 644 (3P0 ! 3F2), and 509 nm (3P0 ! 3H5) at an excitation wavelength of 285 nm.

선박교통관제(VTS)·상황실·경비세력 간 협업 강화 및 연안VTS 업무 내실화 방안

김종진,정경복 한국항해항만학회 2021 한국항해항만학회 학술대회논문집 Vol.2021 No.5