유동화 재순환 반응기에서 석유의 수소첨가 반응시 이탈된 온도제어

이창우,홍영호,함영민 한국산업안전학회 1998 한국안전학회지 Vol.13 No.2

This study was carried out to investigate the effect of on temperature control from actuating method, recycling ratio and the position (top, middle and bottom) of set and controlled temperature within the reactor in adiabatic ebullated recycling condition, when the disturbance was occured. Estimation of the solution were performed numerically using the finite difference method. It was assumed that the reaction is in constant with heat of reaction and the physical properties (density, heat capacity and viscosity, etc) of the reactants are same condition within the reactor.

A Model for Computer-Aided Process Planning System in Flexible Manufacturing Systems

Kang, Young-Sig,Hahm, Hyo-Joon,Rim, Suk-Chul,Kim, Seung-Baum The Korean Society for Quality Management 1994 품질경영학회지 Vol.22 No.1

Most of computer-aided process planning(CAPP) systems have been developed to automate the process planning function. In this paper, we describe an analytical model for a CAPP system in order to improve the performance of production system in flexible manufacturing systems(FMSs) for computer intergrated manufacturing(CIM) architecture. This paper proposes an optimal process planning that minimizes the load time by minimizing the cycle time and the number of workstations using Kang and Hahm's heuristic approach so as to improve the performance of production system under the batch production of discrete products. We also perform simulation using SIMAN language to campare the line utilization of each for various product types. The proposed algorithm can be implemented in existing FMSs for on-line control of product quantity using programmable logic controllers(PLC) and communication devices.

한국과 일본 대학생의 스포츠상황에 대한 도덕적 가치판단수준 비교

함정혜(Chung Hae Hahm) 한국여성체육학회 2013 한국여성체육학회지 Vol.27 No.1

The purpose of this study was to compare the differences of moral reasoning among general students, sports related majors students, and student athletes in Korea and Japan University. We collected total 612 out of 700 (315 from Korea, 297 from Japan) and 88 questionnaires were excluded questionnaire due to incompleteness and unreliable data. For this study, Hahm-Bellar Values Choice Inventory-16(HBVCI-16), which is a Moral Reasoning Questionnaire on Sports Activities, was used. The collected data was analyzed by t-test, one way ANOVA and two way ANOVA with using SPSS Var. 17.0 statistical package program and result were as follow. First, the Japan student`s overall score of moral reasoning were lower compare to Korean university students. Second, there were 1 % higher score of moral reasoning in woman against man and in younger subjects. Sports majored university students presented 1% higher score against other related students and higher grade students presented 5% higher score against lower grade students. Third, among student athletes of Korea and Japan, although there were no significant differences, it was 0.1% higher among those who engaged in individual sports and 5% higher score in those who have less sports career.

Effects of the Hinge Region of Cecropin A(1-8)-Melittin 2(1-12),a Synthetic Antimicrobial Peptide on Antibacterial, Antitumor, and Vesicle-Disrupting Activity

Hahm,Kyung-Soo,Kim,Kii Lyong,Shin,Song Yub,Kang,Joo Hyun,Jang,So Yun The Korea Science and Technology Center 1999 BMB Reports Vol.32 No.6

CA(1-8)-ME(1-12) [CA-ME], composed of cecropin A(1-8) and melittin(1-12), is a synthetic antimicrobial peptide having potent antibacterial and antitumor activities with minimal hemolytic activity. In order to investigate the effects of the flexible hinge sequence, Gly-Ile-Gly, of CA-ME on antibiotic activity, CA-ME and three analogues, CA-ME1, CA-ME2 ,and CA-ME3, were synthesized. The Gly-Ile-Gly sequence of Ca-ME was deleted in CA-ME1 and replaced with Pro and Gly-Pro-Gly in CA-ME2 and CA-ME3, respectively. CA-ME1 and CA-ME3 showed a significant decrease in antitumor activity and phospholipid vesicle-disrupting ability. However, CA-ME2 showed similar antitumor and vesicle-disrupting activities, as compared with CA-ME. These results suggest that the flexibility or β-turn induced by Gly-Ile-Gly or Pro in the central part of CA-ME may be important in the electrostatic interaction of the N-terminus cationic α-helical region with the cell membrane surface and the hydrophobic interaction of the C-terminus amphipathic α-helical region with the hydrophobic acyl chains in the cell membrane. CA-ME3 exhibited lower antitumor and vesicle-disrupting activities than CA-ME and CA-ME2. This result suggests that the excessive β-turn structure caused by the Gly-Pro-Gly sequence in CA-ME3 seems to interrupt ion channel/pore formation in the lipid bilayer. We concluded that the appropriate flexibility or bilayer. We concluded that the appropriate flexibility or β-turn structure provided by the central hinge is responsible for the effective antibiotic activity of the antimicrobial peptides with the helix-hinge-helix structure.

Who participates in the gastric cancer screening and on-time rescreening in the National Cancer Screening Program? A population-based study in Korea.

Hahm, Myung-Il,Choi, Kui Son,Lee, Hoo-Yeon,Jun, Jae Kwan,Oh, Dongkwan,Park, Eun-Cheol Japanese Cancer Association 2011 Cancer Science Vol.102 No.12

<P>Gastric cancer (GC) screening is a major challenge in countries where the disease is highly prevalent. This study was conducted to identify the factors associated with participation in GC screening and on-time rescreening among the average-risk population in Korea. The study population was derived from the National Cancer Screening Program database. The population for this study was 22 913 618 individuals aged ???40 years who had been invited to participate in a GC screening program from 2005 to 2006. We determined whether these individuals had attended the GC screening program and which method - an upper gastrointestinal series (UGIS) or endoscopy-they underwent. We followed the participants to determine whether they had a second GC screening after 2 years. The overall participation rate in the GC screening was 20.5%. More people underwent UGIS than endoscopy. Individuals who had been screened by endoscopy rather than UGIS were more likely to be younger, male, or those who were National Health Insurance (NHI) beneficiaries with a higher premium rate. Of those who underwent baseline screening, 59.4% participated in a rescreening program 2 years later. NHI beneficiaries with a higher premium rate were significantly more likely to be rescreened than medical aid recipients. The results from this study showed that the UGIS were more commonly used in organized GC screenings in Korea, and those who underwent UGIS were more likely to return for subsequent screening compared to those who underwent an endoscopy.</P>

Phosphorylation of GLUT4-containing Low Density Microsome Proteins by Insulin

Hahm, Kyung-Hee,Hah, Jongsik,Hur, Kyu Chung 이화여자대학교 생명과학연구소 1995 생명과학연구논문집 Vol.6 No.-

To understand a possible insulin mediated translocation mechanism of the insulin dependent glucose trnaspoter(GLUT4) from the intracellular vesicles to the plasma membrane, we investigated the phosphorylation of membrane proteins in GLUT40containing vesicles by the kinases which are related to the Ras signalling system. When 3T3-L1 adipocytes were treated with insulin, the increase of GLUT4 translocation from the intracellular vesicle to the pllasma membrane was observed by immunofluorescence microscioy. In the anti-Ras immunopreciptates from the 3T3-L1 adipocytes, there was no change in the amount of GAP and ERK by insulin trearement. However, the tyrosine phosppphorylation of the GAP and ERK was increased in the anti-Ras immunoprecupitates from the insulin trated cells. In case of MEK, the amount was increased by the insulin treatment. Severla components of the immunopurified LDM proteins(62, 46, 42, and 33.5 kDa) were phosphorylated when LDM was incubated with the anti-Ras immunoprecipitates. Inaddition, the amount of ^32P-incorporation into each component was increased when LDM was phosphorylated with the insulin-treated anti-Ras imunoprecipitates. Theses results suggest that the phosphorylation of LDM components by activated Ras associated kinases may have role on the insulin-regulated translocation of GLUT4 molecules from the intracellular vesicle to the plasma membrane.

8-Oxoguanine: from oxidative damage to epigenetic and epitranscriptional modification

Hahm Ja Young,Park Jongyeun,Jang Eun-Sook,Chi Sung Wook 생화학분자생물학회 2022 Experimental and molecular medicine Vol.54 No.-

In pathophysiology, reactive oxygen species control diverse cellular phenotypes by oxidizing biomolecules. Among these, the guanine base in nucleic acids is the most vulnerable to producing 8-oxoguanine, which can pair with adenine. Because of this feature, 8-oxoguanine in DNA (8-oxo-dG) induces a G > T (C > A) mutation in cancers, which can be deleterious and thus actively repaired by DNA repair pathways. 8-Oxoguanine in RNA (o8G) causes problems in aberrant quality and translational fidelity, thereby it is subjected to the RNA decay pathway. In addition to oxidative damage, 8-oxo-dG serves as an epigenetic modification that affects transcriptional regulatory elements and other epigenetic modifications. With the ability of o8G•A in base pairing, o8G alters structural and functional RNA–RNA interactions, enabling redirection of posttranscriptional regulation. Here, we address the production, regulation, and function of 8-oxo-dG and o8G under oxidative stress. Primarily, we focus on the epigenetic and epitranscriptional roles of 8-oxoguanine, which highlights the significance of oxidative modification in redox-mediated control of gene expression.

The molecular mechanisms of vitamin C on cell cycle regulation in B16F10 murine melanoma

Hahm, Eunsil,Jin, Dong-Hoon,Kang, Jae Seung,Kim, Young-In,Hong, Seung-Woo,Lee, Seung Koo,Kim, Ha Na,Jung, Da Jung,Kim, Jee Eun,Shin, Dong Hoon,Hwang, Young Il,Kim, Yeong Seok,Hur, Dae Young,Yang, Yool Wiley Subscription Services, Inc., A Wiley Company 2007 Journal of cellular biochemistry Vol.102 No.4

<P>Vitamin C has inconsistent effects on malignant tumor cells, which vary from growth stimulation to apoptosis induction. It is well known that melanoma cells are more susceptible to vitamin C than any other tumor cells, but the precise mechanism remains to be elucidated. In the present study, the proliferation of B16F10 melanoma cells was suppressed by vitamin C, which induced growth arrest in a dose-dependent manner without cytotoxic effects. Therefore, we investigated the changes in cell cycle distribution of B16F10 melanoma cells by staining DNAs with propidium iodide (PI). The growth inhibition of B16F10 melanoma by vitamin C was associated with an arrest of cell cycle distribution at G1 stage. In addition, the levels of p53-p21<SUP>Waf1/Cip1</SUP> increased during G1 arrest, which were essential for vitamin C-induced cell cycle arrest. The increased p21<SUP>Waf1/Cip1</SUP> inhibited CDK2. Moreover, the activity of p53-p21<SUP>Waf1/Cip1</SUP> pathway was closely related with the activation of checkpoint kinase 2 (Chk2). Inhibitor of the PI3K-family, LY294002 and the ATM/ATR inhibitor, caffeine, blocked vitamin C-induced growth arrest in B16F10 melanoma cells. These results suggest that vitamin C might be a potent agent to inhibit proliferative activity of melanoma cells via the regulation of Chk2-p53-p21<SUP>Waf1/Cip1</SUP> pathway. J. Cell. Biochem. 102: 1002–1010, 2007. © 2007 Wiley-Liss, Inc.</P>

함병춘 유고논문 Korean Perception of America

hahm, pyong-choon 단국대사학회 1983 史學志 Vol.17 No.1

High‐Performance n‐Channel Thin‐Film Field‐Effect Transistors Based on a Nanowire‐Forming Polymer

Hahm, Suk Gyu,Rho, Yecheol,Jung, Jungwoon,Kim, Se Hyun,Sajoto, Tissa,Kim, Felix S.,Barlow, Stephen,Park, Chan Eon,Jenekhe, Samson A.,Marder, Seth R.,Ree, Moonhor WILEY‐VCH Verlag 2013 Advanced functional materials Vol.23 No.16

<P><B>Abstract</B></P><P>A new electrontransport polymer, poly{[<I>N,N′</I>‐dioctylperylene‐3,4,9,10‐bis(dicarboximide)‐1,7(6)‐diyl]‐<I>alt</I>‐[(2,5‐bis(2‐ethyl‐hexyl)‐1,4‐phenylene)bis(ethyn‐2,1‐diyl]} (PDIC8‐EB), is synthesized. In chloroform, the polymer undergoes self‐assembly, forming a nanowire suspension. The nanowire's optical and electrochemical properties, morphological structure, and field‐effect transistor (FET) characteristics are investigated. Thin films fabricated from a PDIC8‐EB nanowire suspension are composed of ordered nanowires and ordered and amorphous non‐nanowire phases, whereas films prepared from a homogeneous PDIC8‐EB solution consist of only the ordered and amorphous non‐nanowire phases. X‐ray scattering experiments suggest that in both nanowires and ordered phases, the PDIC8 units are laterally stacked in an edge‐on manner with respect to the film plane, with full interdigitation of the octyl chains, and with the polymer backbones preferentially oriented within the film plane. The ordering and orientations are significantly enhanced through thermal annealing at 200 °C under inert conditions. The polymer film with high degree of structural ordering and strong orientation yields a high electron mobility (0.10 ± 0.05 cm<SUP>2</SUP> V<SUP>−1</SUP> s<SUP>−1</SUP>), with a high on/off ratio (3.7 × 10<SUP>6</SUP>), a low threshold voltage (8 V), and negligible hysteresis (0.5 V). This study demonstrates that the polymer in the nanowire suspension provides a suitable material for fabricating the active layers of high‐performance n‐channel FET devices via a solution coating process.</P>