Optical spectroscopy of PPV-based block copolymers of nanostructured supramolecular organic semiconductor.

Yang, Q,Battle, R,Zhang, C,Ma, S M,Seo, J T,Tabibi, B,Temple, D,Sun, S,Jung, S S,Namkung, M American Scientific Publishers 2009 Journal of Nanoscience and Nanotechnology Vol.9 No.2

<P>The third-order nonlinearity of a PPV-based nanostructured supramolecular organic semiconductor (DBAB), with an electron donor (D) connected to an electron acceptor (A) via nonconjugated and flexible bridge (B) units, was investigated in this work at both near-resonant (532 nm) and nonresonant (1064 nm) wavelength by using degenerate four-wave mixing. The second hyperpolarizabilities of D, A, and DBAB at 532 nm were found to be approximately 2.42 x 10(-43) m2/V2, 7.75 x 10(-44) m2/V2, and 1.80 x 10(-43) m2/V2 in copolarization geometry, and approximately 1.59 x 10(-43) m2/V2, 2.59 x 10(-44) m2/V2, and 1.18 x 10(-43) m2/V2 in orthogonal polarization geometry, respectively. The second hyperpolarizabilities of DBAB at 1064 nm were approximately 1.66 x 10(-46) m2/V2 and approximately 8.77 x 10(-47) m2/V2 for parallel and orthogonal polarization cases.</P>

Nonlinear optical properties of mushroom-shaped CdSe/CdS coreshells.

Ma, S M,Seo, J T,Yu, W,Yang, Q,Tabibi, B,Temple, D,Namkung, M,Heo, J,Kim, W J,Jung, S S American Scientific Publishers 2009 Journal of Nanoscience and Nanotechnology Vol.9 No.2

<P>The third-order nonlinear optical susceptibilities of mushroom-shaped CdSe/CdS coreshells as a function of concentration have been investigated using polarization- and concentration-resolved degenerate four-wave mixing in a resonant region. The effective third-order nonlinear optical susceptibilities, /chi(3)xxxx/ and /chi(3)xyyx/ of CdSe/CdS coreshells were estimated to be approximately 1.86 x 10(-21)-1.03 x 10(-20) m2/V2, and approximately 0.45 x 10(-21)-6.15 x 10(-21) m2/V2, respectively, for various concentrations of approximately 0.64 x 10(-3)-4.95 x 10(-3) mol/m3. The second hyperpolarizabilities, /<gammah>xxxx/ and /<gammah>xyyx/, of CdSe/CdS coreshells were extracted to be approximately 2.37 x 10(-41) m5/V2 and approximately 1.29 x 10(-41) m5/V2, respectively.</P>

선택성장 내부채널 반도체 레이저 다이오드

안형수,양민,이삼녕,정종제 한국해양대학교 산업기술연구소 2002 연구논문집 Vol.19 No.-

The low threshold current and high power selectively inner-channeled laser (SIC LD) was fabricated and estimated by the selective growth using the low-pressure MOCVD (metal organic chemical vapor deposition) method. The minimum threshold currents in the CW (continuous waves) moes of 8.1mA (cavity=250μm) and 12.9mA (cavity=750μm) were achieved with a stabilized fundamental mode. We could obtain the maximum output powers with the uncoated facets of 100mW at pulsed width and 50mW at continuous waves condition in 250μm cavity length. SIC LD is index-guided laser which has new fabrication techniques different from ridge waveguide structure lasers.

가스분무 및 분무성형법에 의한 Al-Pb 베아링 제조에 관한 연구 (1)

양영석,성장현,박신성,정철민,허태녕,정은 대한금속재료학회(대한금속학회) 1990 대한금속·재료학회지 Vol.28 No.9

Spray Forming technology has been developed at the Department of Materials Science and Engineering, Univ. of Ulsan, for the fabrication of tube, billet and plate of Al-12%Pb alloys. Spray Forming Process involves atomizing a stream of molten metals and collecting the droplets on a substrate before they have solidified, The effects of geometry(orifice diameter and tip design) and position of the metal delivery orifice in atomization device on the pressure characteristics at the tip of orifice have been studied. Mathematical model has been developed to predict the velocity and temperature profiles of the droplets as a function of their flight distances. Microstructural characteristics of Al-12%Pb hyper-monotectic alloys by spray forming process were examined. Dense (~99. 4%) material with fine-grained equiaxed microstructure was spray-formed using nitrogen as the atomizing gas. It was found that lead(Pb) particles existing in the microstructure were homogeneously distributed in the aluminium matrix and along the grain boundaries. The shape of lead particle were approximately spherical and the mean particle size was about 3-4㎛.

중년 남성의 갱년기 증상 유･무에 따른 가족관계와 건강증진행위 비교

강민형,김소영,김하은,안상아,양혜지,이예지,이유진,정수영,최윤영,최지윤,신수진,이민경 이화여자대학교 간호과학대학 2017 이화간호학회지 Vol.- No.51

Purpose: The purpose of this study was to examine the difference of family relationship and health promoting behaviors between two groups depending on presence and absence of climacteric symptoms among middle-aged male. Methods: Samples of 220 men aged between 40 and 64 were recruited from metropolitan areas. The subjects responded to self-report questionnaires on general characteristics, climacteric symptoms, family relationship and health promoting behaviors. Data was collected from September 13, 2016 to September 30, 2016 and analyzed by using t-test, Pearson's correlation efficient, -test, frequency and percentage analysis. Result: In general characteristics of subjects, according to the presence or absence of climacteric symptoms, there were significant differences in occupation( =12.12, p=0.02), average monthly incom ( =11.01, p=0.01), and physical condition( =12.07, p=0.02). Mean scores of family relationship(t=-2.784, p=.008) and health promotion behaviors(t=3.629, p=.000) were significantly higher in climacteric symptom group. Significant positive correlation appeared between family relationship and health promoting behaviors in both presence(r=.493, p=.000) and absence group(r=.698, p=.000). But climacteric symptoms were in negative correlation with family relationship(r=-.187, p=.018) and health promoting behavior(r=-.233, p=.002) only in presence group. Conclusion: This study suggests that family relationship and health promoting behaviors should be considered in developing nursing intervention for climacteric middle–aged males.

CBN 과 WA숫돌에 의한 연삭에서 연산력과 표면거칠기 특성

하만경,곽재섭,양재용,정영득,심성보,류인일 한국공작기계학회 2002 한국생산제조학회지 Vol.11 No.1

In this study an experimental investigation was conducted to find the grinding characteristics of ceramics, STD11 and STS304 materials. The grinding force and the microscopic observation of the workpieces were obtained in surface grinding. Grinding characteristics of ceramics were inspected through the microscopic examination, the cutting force, and the surface roughness. It has been found that the grinding force of ceramics is relatively low as compared to that of steels and that CBN wheel has an excellent performance. The surface roughness was measured according to the feedrate and the depth of cut.

간호대생과 의대생의 간호사 이미지 비교

구민진,김수영,방정민,서아영,양희진,윤소람,이윤재,이재은,이지연,정윤경,최수정 이화여자대학교 간호과학대학 2014 이화간호학회지 Vol.- No.48

Purpose: This study aims to analyze the difference in the perception that nursing students and medical students have regarding the image of nurses. Method: The sampling group for this study was made up of 111 nursing students and 117 medicine students, conducted from the 19th August 2013 to 3rd September 2013. The tool used for this study is the “Nurse Image Scale”. The data is analyzed using the SPSS 21.0 program, technical stats, t-test and ANOVA with Scheffe test. Result: There was a notable difference in the results(t=6.94, p<001), with the average image perception score of nurses at 3.84±0.34 amongst nursing students being higher than the 3.50±0.38 amongst Medicine students. The average score of the 4 areas tested, “Qualification of a Nurse”, “Role of a Nurse”, “Social Participation of a Nurse” and “Interpersonal Skills of a Nurse” were all marked higher by the nursing students than the medicine students. The average score became notably higher as the period of practice became shorter with nursing students (F=4.21, p=.043). Furthermore, the average score for the “Qualification of a Nurse” was notably higher as the period of practice became shorter (F=3.98, p=.049). Medical students gave an average score for the “Qualification of a Nurse”(F=3.72, p=.027) and the “Interpersonal Skills of a Nurse”(F=4.11, p=.019) which was relative to the development of a nurse’s image, while the average score for the “Role of a Nurse” was notably higher with a longer period of practice(F=6.65, p=.011). Conclusion: The results of this study suggest that the image perception of a nurse can vary depending on the experience in period of practice. Therefore, together with this study conducted with nursing students and medicine students, there is a need for further studies conducted on image perception of nurses with various experience in period of practice.

Microphysical characteristics of frozen droplet aggregates from deep convective clouds

Um, Junshik,McFarquhar, Greg M.,Stith, Jeffrey L.,Jung, Chang Hoon,Lee, Seoung Soo,Lee, Ji Yi,Shin, Younghwan,Lee, Yun Gon,Yang, Yiseok Isaac,Yum, Seong Soo,Kim, Byung-Gon,Cha, Joo Wan,Ko, A-Reum Copernicus GmbH 2018 Atmospheric Chemistry and Physics Vol.18 No.23

<P>Abstract. During the 2012 Deep Convective Clouds and Chemistry (DC3) experiment the National Science Foundation/National Center for Atmospheric Research Gulfstream V (GV) aircraft sampled the upper anvils of two storms that developed in eastern Colorado on 6 June 2012. A cloud particle imager (CPI) mounted on the GV aircraft recorded images of ice crystals at altitudes of 12.0 to 12.4 km and temperatures (T) from −61 to −55 ∘C. A total of 22 393 CPI crystal images were analyzed, all with maximum dimension (Dmax⁡)<433 µm and with an average Dmax⁡ of 80.7±45.4 µm. The occurrence of well-defined pristine crystals (e.g., columns and plates) was less than 0.04 % by number. Single frozen droplets and frozen droplet aggregates (FDAs) were the dominant habits with fractions of 73.0 % (by number) and 46.3 % (by projected area), respectively. The relative frequency of occurrence of single frozen droplets and FDAs depended on temperature and position within the anvil cloud. A new algorithm that uses the circle Hough transform technique was developed to automatically identify the number, size, and relative position of element frozen droplets within FDAs. Of the FDAs, 42.0 % had two element frozen droplets with an average of 4.7±5.0 element frozen droplets. The frequency of occurrence gradually decreased with the number of element frozen droplets. Based on the number, size, and relative position of the element frozen droplets within the FDAs, possible three-dimensional (3-D) realizations of FDAs were generated and characterized by two different shape parameters, the aggregation index (AI) and the fractal dimension (Df), that describe 3-D shapes and link to scattering properties with an assumption of spherical shape of element frozen droplets. The AI of FDAs decreased with an increase in the number of element frozen droplets, with larger FDAs with more element frozen droplets having more compact shapes. The Df of FDAs was about 1.20-1.43 smaller than that of black carbon (BC) aggregates (1.53-1.85) determined in previous studies. Such a smaller Df of FDAs indicates that FDAs have more linear chain-like branched shapes than the compact shapes of BC aggregates. Determined morphological characteristics of FDAs along with the proposed reconstructed 3-D representations of FDAs in this study have important implications for improving the calculations of the microphysical (e.g., fall velocity) and radiative (e.g., asymmetry parameter) properties of ice crystals in upper anvil clouds. </P>

Sargassum horneri suppresses particulate matter (PM)-induced oxidative DNA damage in M1/M2-polarized alveolar macrophages (AM) of allergic asthma

Hyo Jin Kim,Jiwon Yang,Kalahe Hewage Iresha Nadeeka M,You-Jin Jeon,Hyun Jung Kim,Youngheun Jee 한국실험동물학회 2023 한국실험동물학회 학술발표대회 논문집 Vol.2023 No.2

Mirror pattern of cerebral artery atherosclerosis in patients with ischaemic stroke

Kim, Y. D.,Choi, H. Y.,Jung, Y. H.,Nam, C. M.,Yang, J. H.,Cho, H. J.,Nam, H. S.,Lee, K-Y.,Heo, J. H. Blackwell Publishing Ltd 2009 European Journal of Neurology Vol.16 No.10

<P>Background and purpose: </P><P>Although it has been suggested that bilateral symmetry of atherosclerosis can be found in paired arteries, including external carotid arteries and femoral arteries, it has remained unknown in intracranial arteries. We determined whether bilateral symmetry (a mirror pattern) of atherosclerosis presents in the entire cerebral arterial system.</P><P>Methods: </P><P>Angiographic findings of 795 consecutive patients with ischaemic stroke, after excluding those with cardiac sources of embolism or other causes of stroke, were reviewed retrospectively. The presence (location) and severity (the degree of stenosis) of atherosclerosis were compared between left and right sides at 26 predetermined arteries/segments.</P><P>Results: </P><P>We found 2230 lesions in predetermined segments/arteries from 669 patients. Amongst 509 patients with atherosclerotic lesions at two or more arteries/segments, mirror patterns were observed in 312 patients (61.3%). The mirror pattern increased steeply as the number of atherosclerotic arteries increased and was most frequently found in the carotid bulb (C1, 26.7%), followed by the middle cerebral artery (M1, 14.1%). The severity of stenosis was also correlated between left and right sides, and the correlation was highest in the C1 (<I>r</I> = 0.40, <I>P </I>< 0.001). Multiple logistic regression analyses revealed that the mirror patterns of atherosclerosis were more obvious in C1 and associated with a past history of ischaemic stroke and the number of stenotic lesions.</P><P>Conclusion: </P><P>Atherosclerosis in cerebral arteries may develop and progress in a mirror pattern. In patients with cerebral artery atherosclerosis, the occurrence and progression of atherosclerosis in the contralateral cerebral artery should be considered during follow-up examination.</P>