2주간 간헐적인 저압,저산소 트레이닝이 남녀 지구성선수의 체성분, 유산소성 운동능력 및 혈중 산소포화도에 미치는 영향

남상석 ( S. S. Nam ),이만균 ( M. G. Lee ),선우섭 ( Oo S. Sun ) 한국운동생리학회(구 한국운동과학회) 2011 운동과학 Vol.20 No.3

남상석, 이만균, 선우섭. 2주간 간헐적인 저압·저산소 트레이닝이 남녀 지구성선수의 체성분, 유산소성 운동능력 및 혈중 산소포화도에 미치는 영향. 운동과학, 제20권 제3호. 283-296. 2011. 본 연구에서는 2주간 간헐적(주당 3회)인 저압·저산소 트레이닝이 지구성 운동선수의 체성분, 유산소성 운동능력 및 혈중 산소포화도에 미치는 효과가 성별에 따라 다르게 나타나는지 여부를 규명하고자 하였다. 남자축구선수(n=8명)와 여자 필드하키선수(n=9명)를 대상으로 2,000 m 상당의 저압·저산소 환경에서 2주간, 격일로 총 6회의 트레이닝(자전거타기 30분과 트레드밀 달리기 30분, 총 60분)을 실시하였다. 트레이닝 전후에 해수면 수준과 5,000 m 상당고도에서 각각 사전·사후검사를 실시하였다. 주요 연구결과는 다음과 같다. 1. 체성분의 변화에는 체중을 제외하고 성차가 나타나지 않았다. 2. 해수면 수준에서의 유산소성 운동능력의 변화에는 유의한 성차가 나타나지 않았다. 5,000 m 상당고도에서는 남자선수의 경우 추정된 VO2max를 제외한 모든 변인에서 트레이닝 후 유의하게 증가된 반면, 여자선수의 경우 유의한 변화가 나타나지 않았다. 즉, 5,000 m 상당고도에서의 유산소성 운동능력 변화에는 유의한 성차가 나타났으며, 이는 남녀 간의 근육량의 차이에 일부 기인하는 것으로 확인되었다. 3. 혈중 산소포화도의 변화에는 성차가 나타나지 않았다. 이상의 결과를 종합해 볼 때, 지구성 종목의 남녀 선수를 대상으로 2주간 간헐적인 저압·저산소 트레이닝을 실시한 경우 5,000 m 상당의 높은 고지대 환경에서의 유산소성 운동능력 개선이 여자에 비해 남자에게서 더 크게 나타난 것으로 결론지을 수 있다. This study was designed to investigate the effects of gender on changes of body composition, aerobic exercise capacity, and %SpO2, shown by two weeks of intermittent hypobaric hypoxia training on in endurance athletes. Male soccer players (n=8) and female hockey players (n=9) underwent the exercise training (cycling 30 min & running 30 min, total 60 min) in 2,000 m-simulated hypobaric hypoxia environment every other day (six times) for 2 weeks. Pre-test and post-test were performed in sea level and 5,000 m-simulated hypobaric hypoxia before and after the training, and the data were compared by gender and test. Main results of the study were as follows: 1. No significant gender difference was shown in changes of body composition, except body weight. 2. No significant gender difference was shown in changes of aerobic exercise capacity in sea level. There were significant improvements of aerobic capacity in 5,000 m condition in male athletes, whereas there were no significant changes of the variables in female athletes, indicating that significant gender difference was found in the changes of aerobic capacity in 5,000 m condition. 3. No significant gender difference was shown in changes of %SpO2. It was concluded that the improvement of aerobic exercise capacity in 5,000 m condition shown by short-term intermittent hypobaric hypoxia training was greater in male athletes than in female athletes.

HVOF와 LPPS로 제조된 단층 열차폐 코팅의 고온 물성에 관한 연구

남영민,송요승 한국 항공대학교 항공산업기술연구소 2000 航空宇宙産業技術硏究所 硏究誌 Vol.10 No.-

본 연구에서는 HVOF법과 LPPS법으로 제조된 CoNiCrAlY 단층 열차폐 코팅의 미세구조 분석, 고온산화시험, 그리고 열피로시험 등 종합적인 기계적, 열적 물성을 평가하였다. HVOF법과 LPPS법으로 제조된 피막의 두께는 각각 450∼500μm, 350∼450μm 정도였으며 경도는 각각 350Hv∼400Hv, 370Hv∼420Hv의 분포를 보였고 모재와 코팅층의 경계가 확실히 구분되지 않았다. 단면 관찰결과 두 피막 모두에서 열처리에 의한 확산의 영향으로 Al-rich 상이 나타났으며 코팅층 표면은 β상과 γ상으로 이루어져 있었다. 또한 기공도는 1∼2%정도를 나타내었으며 LPPS 시편에서 더 낮은 기공도를 유지하였다. 고온산화시험에서는 코팅층 표면에 10∼20μm 정도의 두께를 가진 oxide scale이 형성되었으며 산화하기 전에 보이는 Al-rich 상들이 점차적으로 사라지는 것이 발견되었다. 열피로시험 결과 표면과 계면부위에 커다란 기공이 형성되었으며 LPPS 시편이 HVOF 시편보다 더 나은 내열피로 특성을 나타내었다. In this study the evaluations of mechanical and thermal properties of FGM-TBC such as oxidation and fatigue at high temperatures have been conducted. The samples of bond coat produced by High Velocity Oxygen Fuel (HVOF) and Low Pressure Plasma Spray (LPPS) method were used. The thickness values of HVOF coating was about 450μm to 500μm and the hardness of coating was about 350Hv to 400Hv. The thickness values of LPPS coating was about 350μm to 450μm and the hardness number of coating was about 370Hv to 420Hv. The XRD analyzes showed that CoNiCrAlY coating layer of HVOF and LPPS was composed of β and γ phase after spraying. The cross sectional image showed Al-rich phase which was influenced by diffusion. After high temperature oxidation test of HVOF and LPPS, the oxide scale with about 10μm to 20μm thickness at coating surface was appeared and under the oxide scale layer the Al-depleted zone was observed. And, Al-rich phase which showed before oxidation test disappeared gradually. After thermal fatigue test of HVOF and LPPS, coarse pores were observed at the surface and interface area. The thermal fatigue resistance of LPPS coating is better than those of HVOF coating.

The Composition and Productivity of a Grassland in Korea

Kim, Choon M.,Lee, Il K.,Park, Bong k.,Chang, Nam K. 서울대학교 교육대학원 1969 論文集 - 서울대학교 교육대학원 Vol.6 No.-

The vascular florae of the north, northwest and south sides of a stand in the piedmont on the Choon-sung area were composed of 50, 41, and 34 species respectively. The most important of these were Arundinella hirta and Miscanthus sinensis. These two species contributed greatly to the standing crop of live material, which was in excess of 308.66g/m² during the growing season. The peak net productions of organic matter of 61.53g/m, 231.40g/m², and 214.65g/m² for these grasslands were reached in July-August under abundant water conditions, and were largely due to the high productivity of the dominant species such as A. hirta and M. sinensis. The average standing crop of this grassland plant communities was in excess of 571.01g/m² for the one growing season. This value would be increased if the productivity of the moss and algal mats which cover the soil surface during the growing season were included.

Defect reduction of SiN_x embedded m-plane GaN grown by hydride vapor phase epitaxy

Woo, S.,Kim, M.,So, B.,Yoo, G.,Jang, J.,Lee, K.,Nam, O. North-Holland Pub. Co 2014 Journal of crystal growth Vol.407 No.-

Nonpolar (10-10) m-plane GaN has been grown on m-plane sapphire substrates by hydride vapor phase epitaxy (HVPE). We studied the defect reduction of m-GaN with embedded SiN<SUB>x</SUB> interlayers deposited by ex-situ metal organic chemical vapor deposition (MOCVD). The full-width at half-maximum values of the X-ray rocking curves for m-GaN with embedded SiN<SUB>x</SUB> along [11-20]<SUB>GaN</SUB> and [0001]<SUB>GaN</SUB> were reduced to 528 and 1427arcs, respectively, as compared with the respective values of 947 and 3170arcs, of m-GaN without SiN<SUB>x</SUB>. Cross-section transmission electron microscopy revealed that the basal stacking fault density was decreased by approximately one order to 5x10<SUP>4</SUP>cm<SUP>-1</SUP> due to the defect blocking of the embedded SiN<SUB>x</SUB>. As a result, the near band edge emission intensities of the room-temperature and low-temperature photoluminescence showed approximately two-fold and four-fold improvement, respectively.

The influence of flavonoid compounds on the in vitro inhibition study of a human fibroblast collagenase catalytic domain expressed in E. coli

Nguyen, T.T.H.,Moon, Y.H.,Ryu, Y.B.,Kim, Y.M.,Nam, S.H.,Kim, M.S.,Kimura, A.,Kim, D. IPC Science and Technology Press ; Elsevier Scienc 2013 Enzyme and microbial technology Vol.52 No.1

The human fibroblast collagenase catalytic domain (MMP1ca) that is considered a prototype for all interstitial collagenase and plays an important role in the turnover of collagen fibrils in the matrix was expressed as an inclusion body in the Escherichia coli. The purified enzyme displayed activity with substrate Dnp-Pro-Leu-Ala-Leu-Trp-Ala-Arg-OH with a K<SUB>m</SUB> value of 26.61+/-1.42μM. The inhibition activity of the nine flavonoid compounds and gallic acid against MMP1ca was examined. Among the compounds tested, the IC<SUB>50</SUB> of seven flavonoid compounds were determined and ranged from 14.13 to 339.21μM. Epigallocatechin gallate (EGCG) showed the highest inhibition toward MMP1ca with IC<SUB>50</SUB> values of 14.13+/-0.49μM. EGCG showed a competitive inhibition pattern with a K<SUB>i</SUB> value of 10.47+/-0.51μM. The free binding energy of EGCG against MMP1ca was -13.07kcalmol<SUP>-1</SUP>, which was calculated by using Autodock 3.0.5 software and showed numerous hydrophobic and hydrogen bond interactions. The galloyl group of EGCG, gallocatechin gallate and epicatechin gallate was determined to be important for inhibitory activity against MMP1ca.

Optical subthreshold current method for extracting the interface states in MOS systems

Kim, M.S.,Nam, I.C.,Kim, H.T.,Shin, H.T.,Kim, T.E.,Park, H.S.,Kim, K.S.,Kim, K.H.,Choi, J.B.,Min, K.S.,Kim, D.J.,Kang, D.W.,Kim, D.M. IEEE 2004 IEEE electron device letters Vol.25 No.2

Optical subthreshold current method (OSCM) is proposed for characterizing the interface states in MOS systems using the current-voltage characteristics under a photonic excitation. An optical source with a subbandgap (E<SUB>ph</SUB>>E<SUB>g</SUB>) photonic energy (E<SUB>ph</SUB>=0.943 eV, P<SUB>opt</SUB>=+5 dBm), which is less than the silicon bandgap (E<SUB>g</SUB>=1.12;eV), is employed for the optical subthreshold current characterization of interface states in the photoresponsive energy band. We applied the OSCM method under a subbandgap photonic excitation to MOS systems with a poly-Si gate and verified a U-shaped distribution of interface trap density D<SUB>it</SUB>=10<SUP>10</SUP>∼10<SUP>12</SUP> eV<SUP>-1</SUP>cm<SUP>-2</SUP> for n- and p-type MOSFETs with W/L=30 μm/1.2 μm.

Effect of nitrogen addition and annealing temperature on superelastic properties of Ti-Nb-Zr-Ta alloys

Tahara, M.,Kim, H.Y.,Hosoda, H.,Nam, T.h.,Miyazaki, S. Elsevier Sequoia 2010 Materials science & engineering. properties, micro Vol.527 No.26

The composition dependence of the mechanical properties and martensitic transformation behavior of Ti-Nb-4Zr-2Ta-N alloys is investigated. The effect of annealing temperature on the microstructural evolution and superelastic properties in the N-added and N-free alloys is compared. The addition of N decreases M<SUB>s</SUB> of Ti-Nb-4Zr-2Ta alloys by about 200K per 1at.%N and improves the superelastic properties of Ti-Nb-4Zr-2Ta alloys. The dissolution of α phase increases the martensitic transformation start temperature and decreases the superelastic recovery strain for the N-free alloy, whereas it causes opposite effects for the N-added alloy. The different annealing temperature dependences of superelastic properties are discussed on the basis of microstructure observation.

Edge-directed [(M₂)₂L₄] tetragonal metal–organic polyhedra decorated using a square paddle-wheel secondary building unit

Jaya Prakash, M.,Oh, Minhak,Liu, Xinfang,Han, Kwi Nam,Seong, Gi Hun,Lah, Myoung Soo Royal Society of Chemistry 2010 Chemical communications Vol.46 No.12

<P>A general strategy was developed for edge-directed self-assembly of tetragonal metal–organic polyhedra (MOPs) having a <I>C</I><SUB>4</SUB> symmetry Cu<SUP>II</SUP><SUB>2</SUB>(COO)<SUB>4</SUB> paddle-wheel as a secondary building unit, using <I>C</I><SUB>2</SUB> symmetric dicarboxylic ligands as pincer-type primary building units.</P> <P>Graphic Abstract</P><P>Augmented tetragonal metal–organic polyhedra (MOPs) were self-assembled from <I>C</I><SUB>2</SUB> symmetric bidentate ligands based on a Cu(<SMALL>II</SMALL>) paddle-wheel moiety as a secondary building unit, where the ligands occupy the edges of the tetragonal cages. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=b925335a'> </P>

Tissue Culture and Production of Secondary Metabolites of Domestic Medicinal Herbs-Ⅱ. Production of Secondary Metabolites of Pinellia ternata and Melandryum firmum

Yang, M.S.,Choi, S.U.,Nam, S.H.,Kim, L.S. Gyeongsang National University 1991 Plant molecular biology and biotechnology research Vol.1991 No.

Pinellia ternata Thunb. and Melandryum firmum Rohbach used as medicinal herbs were cultured and analyzed secondary metabolites. The saponin contents were the highest level between 25 and 30 culture days. The addition of phenylalanine and methionine in medium effected the ephedrine production in P. ternata. The effective precursors on saponin production were sitosterol and mevalonate in P. ternata and M. firmum. Protocom-like body derived from P. ternata was produced to the most amount of saponin and ephedrine.

대학생의 스마트폰 중독, 불안 및 수면의 질에 대한 연구

김민지,염영은,전지은,조현정,최수민,계향미,김가현,남은재,박신영,박지영 이화여자대학교 간호과학대학 2014 이화간호학회지 Vol.- No.48

Purpose: The purpose of this study was to learn about smartphone addiction level, anxiety, and sleep quality among undergraduate students. Method: In this cross-sectional design study, a convenient sample of 231 undergraduate students were recruited between August and September, 2013. Questionnaires used for this study were the Smartphone addiction proneness scale for adults, the STAI (State-Trait Anxiety Inventory), and the PSQI (Pittsburgh Sleep Quality Index). Data were statistically analyzed using descriptive statistics, t-test, Pearson’s correlation, and ANOVA. Result: About 44 percent of the participants used smartphones in order to communicate with others; SNS (Social Network Service) was the most frequently used function among participants. 59 participants (25.5%) were smartphone addiction potentially risk group and 22 participants (9.5%) were high-risk group. Sex and amount of time used per day had significant influences on smarphone addiction score. There were statistically significant relationships among smartphone addiction level, anxiety, and quality of sleep. The smartphone addiction high-risk group had significantly higher trait anxiety scores compared to the normal group. Conclusion: Smartphone addiction was a risk factor for both anxiety and quality of sleep among undergraduate students. The proposals of this study are as follows: first, in-depth studies are required with regard to the intervention for high frequency of smartphone use and the influence of smartphone addiction as a risk factor of anxiety and mental health. Second, a smartphone addiction treatment program should be supplemented as one of the interventions for anxiety. Third, as an intervention for sleep quality, not only should sleep patterns be considered, but one’s behaviors or habits should be taken into account, particularly at the level of smartphone addiction and anxiety.