Three Temperature Model for Nonequilibrium Energy Transfer in Semiconductor Films Irradiated with Short Pulse Lasers

Lee, Seong Hyuk,Sim, Hyung Sub,Lee, Junghee,Kim, Jong Min,Shin, Young Eui The Japan Institute of Metals 2006 MATERIALS TRANSACTIONS Vol.47 No.11

<P>This article investigates numerically carrier-phonon interaction and nonequilibrium energy transfer in direct and indirect bandgap semiconductors during sub-picosecond pulse laser irradiation and also examines the recombination effects on energy transport from the microscopic viewpoint. In addition, the influence of laser fluence and pulse duration is studied by using the self-consistent three-temperature model, which involves carriers, longitudinal optical phonons, and acoustic phonons. It is found that a substantial non-equilibrium state exists between carriers and phonons during short pulse laser irradiation because of time scale difference between the relaxation time and the pulse duration. It is clear that the two-peak structure in carrier temperature exists and it depends mainly on laser pulses, fluences, and recombination processes. During laser irradiation, in particular, the Auger recombination for Si becomes dominant due to the increase in the carrier number density, whereas for GaAs, the Auger recombination process can be ignored due to an abrupt increase in SRH recombination rates at the initial stages of laser exposure.</P>

Shelf Life Determination of Precooked Frozen Meat Dumplings

Lee, Young-Chun,Yang, Hyung-Sub,Kim, Dong-Ho 한국산업식품공학회 2002 산업 식품공학 Vol.6 No.3

Quality of frozen foods is significantly affected by the storage temperature and tie, and the consumers' demand for safe quality frozen foods is increasing. The objective of this research was to estimate the shelf life of frozen cooked meat dumplings, based on the changes in the selected physico-chemical and sensory quality attributes. Precooked frozen meat dumplings sampled from the same lot produced at a frozen food company in Seoul were stored at -10, -15, and -20℃. The meat dumplings sampled at 3- to 4-week intervals were subjected to the determination of volatile basic nitrogen (VBN), thiobarbituric acid (TBA), peroxide value (POV), surface color and shear value after thawing at 5℃ for 15 h. High quality life (HQL) was determined through the triangle test and practical quality life (PQL) through the scoring test. VBN, TBA and POV increased as the storage period was increased. HQL of the frozen meat dumplings were 189 and 252 days at -10 and -15℃, respectively. The estimated PQL were 349, 475, and 491 days at -10, -15, and -20 ℃, respectively. Statistical analysis indicated that there were significant relationships between sensory scores and VBN and POV of the stored meat dumplings. VBN was selected as the most reliable objective quality index for the shelf life determination (PQL) of the precooked frozen meat dumplings.

Experimental investigation of macroscopic material nonlinear behavior and microscopic void volume fraction change for porous materials under uniaxial compression

Lee, Eun Sun,Goh, Tae Sik,Lee, Jung Sub,Heo, Jin-Young,Kim, Gi-Baek,Lee, Chi-Seung Elsevier 2019 Composites Part B, Engineering Vol.163 No.-

<P><B>Abstract</B></P> <P>The purpose of this study was to simultaneously analyze the nonlinear behavior and the void volume fraction change of polyurethane foam (PUF) under a uniaxial compressive load through micro-scale and macro-scale viewpoints. The influence of micro-scale factors on the macroscopic properties of PUF was analyzed, along with the interrelationships between micro-scale and macroscopic properties. The microstructure of PUF was observed by analyzing the density. Various micro-analyses were also conducted, including those for energy absorption, Young's modulus, and recovery behaviors. Internal structure changes such as those in density and degree of compressive strain were analyzed by measuring the void volume fraction of each region in the specimen under a uniaxial compressive load. The elastic, plateau, densification, and fracture regions of the compressive test stress-strain curve were divided, analyzed, and compared with microscopic analysis results. Based on the results of the macro-micro-scale experiment, we analyzed influence and change process of microstructures on the compressive behavior of the PUF specimen in detail. This study shows that internal and overall changes in the compression process of various porous materials can be predicted under a uniaxial compressive load.</P>

2,4-bis (p-hydroxyphenyl)-2-butenal (HPB242) induces apoptosis via modulating E7 expression and inhibition of PI3K/Akt pathway in SiHa human cervical cancer cells.

Kim, Man Sub,Kim, Jung Hee,Bak, Yesol,Park, Yun Sun,Lee, Dong Hun,Kang, Jeong Woo,Shim, Jung-Hyun,Jeong, Heon Sang,Hong, Jin Tae,Yoon, Do Young Lawrence Erlbaum Associates, Publishers [etc.] 2012 Nutrition and cancer Vol.64 No.8

<P>The Maillard reaction is a chemical reaction occurring between an amino acid and a reducing sugar, usually requiring thermal processing. Maillard reaction products (MRPs) have antioxidant, antimutagenic, and antibacterial effects, and although 2,4-bis (p-hydroxyphenyl)-2-butenal (HPB242), a fructose-tyrosine MRP, appears to inhibit proliferation of cancer cells, its mechanism of action has not been studied in detail. We found that HPB242 treatment modulated expression of cyclins and tumor suppressor genes in SiHa human cervical cancer cell lines: cyclins and phospho-pRB were downregulated, whereas the expression of CDK inhibitors and p53 was enhanced. HPB242 induced apoptosis dose-dependently by suppressing E7 expression and leading to sub-G1 cell-cycle arrest in SiHa cell lines; treatment also led to the proteolytic cleavage of caspase-3, -9, and poly (ADP-ribose) polymerase. Moreover, HPB242 upregulated Fas expression, altered expressions of pro- and antiapoptotic factors, and also inhibited nuclear translocation of nuclear factor κB and phosphorylation of IκB. HPB242 treatment decreased phosphatidyl inositol-3 kinase and p-Akt expression levels, demonstrating that this survival pathway may also be inhibited by HPB242. Cumulatively, HPB242 promotes apoptosis by influencing E7 expression, inducing cell-cycle arrest at sub-G1 phase, and promoting both intrinsic (mitochondrial) and extrinsic (Fas-dependent) apoptosis in SiHa human cervical cancer cells.</P>

Al - Ferrite의 Mossbauer 분광학적 연구

이충섭(Choong-Sub Lee),주한식(Han-Sik Joo),이찬영(Chan-Young Lee),서정철(Jung-Chul Sur) 한국자기학회 1998 韓國磁氣學會誌 Vol.8 No.4

We have studied Al_xFe_(3-x)O₄ produced by direct composition method using X-ray diffraction and Mssbauer spectroscopy. The cation distribution for Al_xFe_(3-x)O₄ was determined by the ratio of sub-spectra absorption area. The charge state of Fe atoms in octahedral site(B-site) is Fe^(2.5+) based on electron hopping, Fe²+ ↔ (Fe³+, Al³+) without dependency of substituted Al amounts.

철도시스템분야 실무적용을 위한 RAM Guidance 개발에 관한 연구

이중섭(Joong Sub31 Lee),백영구(Young Goo Baek),이진(Jin Lee),한미정(Mi Jung Han),김성환(Sung Hwan Kim) 한국철도학회 2015 한국철도학회 학술발표대회논문집 Vol.2015 No.10

철도시스템 기술 고도화 및 복잡성의 증대와 더불어 발주기관으로부터 시스템의 성능보증과 안전성 확보가 요구되고 있는 실정이다. 또한 국내 철도안전법 강화로 인하여 시스템 보증활동의 중요성이 증가되고 있다. 본 논문에서는 국제철도관련 규격을 바탕으로 철도시스템의 RAM 업무에 대한 절차를 정의하고, 해당 철도 프로젝트에서 RAM 업무를 원활히 수행할 수 있도록 관련된 국제 규격 및 유사시스템 적용 사례에 기반하여 철도시스템 개발 특성을 고려한 RAM 업무 수행 지침(Guidance)을 개발하였다. Performance and safety assurances for the railway system are required by the client because of the high degree of technology and increased complexity. In addition, as a result of reinforced domestic railway safety laws, the importance of system assurance activity has been growing steadily. This paper defines the task of the RAM process based on international railway industry standards for RAMS engineers to work efficiently and develops the RAM guidance considering the railway system characteristics based on domestic standards and application cases of railway systems.

A Synthetic Naringenin Derivative, 5-Hydroxy-7,4′-diacetyloxyflavanone-<i>N</i>-phenyl Hydrazone (N101-43), Induces Apoptosis through Up-regulation of Fas/FasL Expression and Inhibition of PI3K/Akt Signaling Pathways in Non-Small-Cell Lung Cancer Cells

Bak, Yesol,Kim, Heejong,Kang, Jeong-Woo,Lee, Dong Hun,Kim, Man Sub,Park, Yun Sun,Kim, Jung-Hee,Jung, Kang-Yeoun,Lim, Yoongho,Hong, Jintae,Yoon, Do-Young American Chemical Society 2011 Journal of agricultural and food chemistry Vol.59 No.18

<P>Naringenin, a well-known naturally occurring flavonone, demonstrates cytotoxicity in a variety of human cancer cell lines; its inhibitory effects on tumor growth have spurred interest in its therapeutic application. In this study, naringenin was derivatized to produce more effective small-molecule inhibitors of cancer cell proliferation, and the anticancer effects of its derivative, 5-hydroxy-7,4′-diacetyloxyflavanone-<I>N</I>-phenyl hydrazone (N101-43), in non-small-cell lung cancer (NSCLC) cell lines NCI-H460, A549, and NCI-H1299 were investigated. Naringenin itself possesses no cytotoxicity against lung cancer cells. In contrast, N101-43 inhibits proliferation of both NCI-H460 and A549 cell lines; this capacity is lost in p53-lacking NCI-H1299 cells. N101-43 induces apoptosis via sub-G<SUB>1</SUB> cell-cycle arrest in NCI-H460 and via G<SUB>0</SUB>/G<SUB>1</SUB> arrest in A549 cells. Expression of apoptosis and cell-cycle regulatory factors is altered: Cyclins A and D1 and phospho-pRb are down-regulated, but expression of CDK inhibitors such as p21, p27, and p53 is enhanced by N101-43 treatment; N101-43 also increases expression levels of the extrinsic death receptor Fas and its binding partner FasL. Furthermore, N101-43 treatment diminishes levels of cell survival factors such as PI3K and p-Akt dose-dependently, and N101-43 additionally induces cleavage of the pro-apoptotic factors caspase-3, caspase-8, and poly ADP-ribose polymerase (PARP). Cumulatively, these investigations show that the naringenin derivative N101-43 induces apoptosis via up-regulation of Fas/FasL expression, activation of caspase cascades, and inhibition of PI3K/Akt survival signaling pathways in NCI-H460 and A549 cells. In conclusion, these data indicate that N101-43 may have potential as an anticancer agent in NSCLC.</P>

서울의 Penicillinase Producing Neisseria Gonorrhoeae 발생빈도(1994)

김재홍,안진균,정성재,김영태,김중환,김시영,이석종,이홍렬,서호석,김경훈,권혁진,정우권,고우석,이용석,안필수,오준규,오용섭 대한화학요법학회 1996 대한화학요법학회지 Vol.14 No.1

Background : In recent years gonorrhoea has been panendemic and remains one of the most common Sexually Transmitted Diseases in the world, especially in developing countries. Objective & Method : For the detection of a more effective therapeutic regimen and assessing the prevalence of Penicillinase Producing Neisseria Gonorrhoeae(PPNG), Ive have been trying to study the patients who have visited the VD Clinic of Choong-Ku Public Health Center in Seoul since 1980 by means of the chromogenic cephalosporin method. Results : In 1994, 168 strains of N. gonorrhoeae were isolated, among which 109 (64,9% ) were PPNG. Conclustion : Our results suggests that the prevalence of PPNG in Seoul is still increasing.

일부 직업인의 건강증진생활양식에 영향을 미치는 요인 연구

이은경,안병상,유택수,김성천,정재열,박용신,장두섭,송용선,이기남,Lee Eun-Kyoung,An Byung-Sang,Yu Taek-Su,Kim Seoung-Cheon,Jeung Jea-Yeal,Park Young-Shin,Jahng Doo-Sub,Song Yung-Sun,Lee Ki-Nam 대한예방한의학회 2000 대한예방한의학회지 Vol.4 No.2

The current industrial health service is shifting to health improvement business with 1st primary prevention-focused service from secondary and tertiary prevention-focused business, and Oriental medicine can provide such primary prevention-focused service due to the characteristics of its science. In particular, the advanced concept of health improvement can match the science of health care of Oriental medicine. Notably, what is most important in health improvement is our lifestyle, This does not underestimate the socio-environmental factors, which have lessened their importance due to modernism. The approach of Oriental medicine weighs more individuals' lifestyle and health care through self-cultivation. This matches the new model of advanced health business. Oriental medicine is less systemized than Western medicine, but it can provide ample contents that enhance health. If we conceive health-improvement program based on the advantages provided by these two medical systems, this will influence workers to the benefit of their health. Also, health Program needs to define factors that determine individual lives, and to provide information and technologies essential to our lives. The Oriental medicine approach puts more stress on a subject's capabilities than it does on the effect his surrounding environment can have. This needs to be supported theoretically by not only defining the relations between an individual's health state and his lifestyle, but also identifying the degree to which an individual in the industrial work place practices health improvement lifestyle . This is the first step toward initiating health-improvement business . In order to do this, this researcher conducted a survey by taking random samplings from workers, and can draw the following conclusions from it. 1 The sampled group is categorized into', by sender, female 6.6%, and male 93.4%, with males dominant; by marriage status , unmarried 43.9% and married 55.6%, with both similar percentage, and, by age, below 30, 48.4%, between 30 and 39, 27.4%, between 40 and 49, 18.2%, and over 50, 6.0%. The group further is categorized into; by education, middle school or under 1.7%, high school 30.5%, and junior college or higher 65.8% with high school and higher dominant: and by income, below 1.7 million won 24.2%, below 2.4 million won 14.8%, and above 2.4 million 6.3% Still, the group by job is categorized into collegians with 23.9%, office worker with 10.3%, and professionals with 65.8% , and this group does not include workers engaged in production that are needed for this research, but mostly office workers . 2. The subjects selected for this survey show their degree of practicing health-improvement lifestyle at an average of 2.63, health management pattern at 2.64, and health-related awareness at 2.62 The sub-divisions of health-improvement lifestyle show social emotion (2.87), food (2.66). favorite food (2.59), and leisure activities (2.52), in this order for higher points. It further shows health awareness (2.47) and safety awareness (2.40), lower points than those in health management pattern . 3. In the area of using leisure time for health-improvement, males, older people, married, and people with higher income earn higher marks. And, in the area of food management, the older and married earn higher marks . In the area of favorite food management, females, lower-income bracket, and lower-educated show higher degree of practice , while in the area of social emotion management, the older. married, and higher-income bracket show higher marks. In addition, in the area of health awareness, the older, married, and people with higher-income show higher degree of practice. 4. To look at correlation by overall and divisional health-improvement practice degree , this researcher has analyzed the data using Person's correlation coefficient. The lifestyle shows significant correlation with its six sub-divisions, and use of leisure time, food, and health awareness al

[논문]보양조건 및 타설주기를 고려한 매스 콘크리트 구조물의 수화열 해석

이영호,서기영,최덕락,엄장섭,진치섭* 釜山大學校生産技術硏究所 2004 生産技術硏究所論文集 Vol.63 No.-

콘크리트 구조물의 공용수명은 콘크리트 재료의 초기에 발생하는 수화열에 의해 아주 큰 영향을 받는다. 수화열은 콘크리트의 열전달 및 열응력 특성으로 결정되어지는 온도균열지수를 통해 분석되고 있다. 본 연구에서는 이러한 온도균열 지수의 분석을 통해 매스 콘크리트 구조물의 시공시 적절한 시벤트 종류, 보양방법,타설주기 및 타설높이 둥 최적의 시공방안 구하는데 도움을 주어 향후 시공 예정인 매스 콘크리트 구조물에 발생 가능한 온도균열을 미리 예측하여 이를 방지하기 위한 시공 방안을 제안하는데 그 목적을 두고 있다.