• 제목/요약/키워드: N-IR

검색결과 1,454건 처리시간 0.022초

원격강내조사용 Co-60 선원의 대체용 Ir-192 선원의 조사선량결정 및 선량 등방성조사 (Determination of Exposure Dose Rate and Isotropic Distributions of Substitute High Dose Rate Ir-192 Source for Co-60 Brachytherapy Source)

  • 최태진;원철호;김옥배;김시운;김금배;조운갑;한현수;박경배
    • 한국의학물리학회지:의학물리
    • /
    • 제9권1호
    • /
    • pp.55-64
    • /
    • 1998
  • 고선량률 원격 강내조사 선원은 전량 외국에서 수입되어 왔으며, 최근 Co-60 소선원의 공급부진으로 초기 도입시의 치료시간에 비해 4내지 5배의 시간을 조사하게 되어 대체용 선원의 개발이 크게 요구되고 있다. 이 연구는 국내 하나로 원자로의 중성자를 이용하여 $^{191}$ Ir(n,Υ)$^{192}$ Ir 핵반응을 일으켜 Ir-192 선원 2.87 Ci (밀봉 1.012 Ci)를 생산하고, 고선량률 원격 강내조사선원의 선량특성을 조사하였다. 제작선원에 대한 조사선량률은 아크릴 지지체의 중앙에 아크릴 아프리케이터를 고정하고 선원의 중심으로부터 각각 5, 10, 20 cm 거리에 전리함을 설치하여 일정시간 선원을 노출시켜 측정한 결과 6.36 $\pm$ 0.147 Rm$^2$/GBq-hr (2.350 $\pm$ 0.054 R$cm^2$/mCi-hr)을 결정하였으며, 측정오차는 1$\sigma$ 는 2.2% 였다. 계산선량은 조사선량률 상수 4.69 R$cm^2$/h-mCi 와 Ir-192 에너지 스펙트럼을 이용한 선원자체 및 철에 대한 질량흡수계수를 통해 구했으며, 실제 측정선량과 평균 3.8 % 오차범위에서 일치하였다. 선량 등방성은 선원의 측방향과 축 및 대각선방향으로 전리함을 이용하여 측정한 결과 3 % 이내 균등한 선량을 나타내었으며, 필름선량에서도 균등선량분포를 확인할 수 있었으며, Co-60 선원과 유사한 선량분포를 얻었을 수 있었다. 특히 본 연구의 선량특성조사는 강내조사선량선원 대체용의 선원개발과 선량계획 전산화의 근거가 될 것으로 믿는다.

  • PDF

WRF 모델에서 모의된 2005년 장마 기간 강수의 동조성 연구 (A Study on the Coherence of the Precipitation Simulated by the WRF Model during a Changma Period in 2005)

  • 변재영;원혜영;조천호;최영진
    • 대기
    • /
    • 제17권2호
    • /
    • pp.115-123
    • /
    • 2007
  • The present study uses the GOES IR brightness temperature to examine the temporal and spatial variability of cloud activity over the region $25^{\circ}N-45^{\circ}N$, $105^{\circ}E-135^{\circ}E$ and analyzes the coherence of eastern Asian summer season rainfall in Weather Research and Forecast (WRF) model. Time-longitude diagram of the time period from June to July 2005 shows a signal of eastward propagation in the WRF model and convective index derived from GOES IR data. The rain streaks in time-latitude diagram reveal coherence during the experiment period. Diurnal and synoptic scales are evident in the power spectrum of the time series of convective index and WRF rainfall. The diurnal cycle of early morning rainfall in the WRF model agrees with GOES IR data in the Korean Peninsula, but the afternoon convection observed by satellite observation in China is not consistent with the WRF rainfall which is represented at the dawn. Although there are errors in strength and timing of convection, the model predicts a coherent tendency of rainfall occurrence during summer season.

Color Tuning of OLEDs Using the Ir Complexes of White Emission by Adjusting the Band Gap of Host Materials

  • Seo, Ji-Hyun;Kim, In-June;Seo, Ji-Hoon;Hyung, Gun-Woo;Kim, Young-Sik;Kim, Young-Kwan
    • Journal of Information Display
    • /
    • 제9권2호
    • /
    • pp.18-21
    • /
    • 2008
  • We report on white organic light-emitting diodes (WOLEDs) based on single white dopants, $Ir(pq)_2$($F_2$-ppy) and $Ir(F_2-ppy)_2$(pq), where $F_2$-ppy and pq are 2-(2,4-difluorophenyl) pyridine and 2-phenylquinoline, respectively. The similar phosphorescent lifetime of two ligands lead to luminescence emission in two ligands simultaneously. However, the emission color of the devices was reddish, because the energy was not transferred efficiently from the 4,4,N,N'-dicarbazolebiphenyl (CBP) to the $F_2$-ppy ligand, due to the small band gap of the CBP. Accordingly, we used 1,4-phenylenesis(triphenylsilane) (UGH2) with a large band gap, instead of CBP as the host material. As a result, it was possible to adjust the emission color by the host material. The luminous efficiency of the device with $Ir(F_2-ppy)_2$(pq) doped in UGH2 was about 11 cd/A at 0.06 cd/$m^2$.

Synthesis and Structure of 1,2,3,4,5-Pentamethylcyclopentadienyl-1,4-Diphenyltetraazabutadiene Complexes of Rhodium and Iridium

  • Paek ,Cheolki;Ko, Jaejung;Kang, Sangook;Patrick J.Carrol
    • Bulletin of the Korean Chemical Society
    • /
    • 제15권6호
    • /
    • pp.432-436
    • /
    • 1994
  • Monomeric rhodium and iridium-diaryltetrazene complexes $Cp^*$M(RNN=NNR)($Cp^*$=1,2,3,4,5-pentamethylcyclope ntadienyl; M=Rh, Ir; R=Ph, 4-tolyl) have been synthesized from [$Cp^*MCl_2]_2$(M=Rh, Ir) and 2 equiv. of $[Li(THF)_x]_2(RN_4$R) in benzene. We have determined the crystal structure of (${\eta}^5$-pentamethylcyclopentadienyl)diphenyltetrazene iridium by using graphite-monochromated Mo-$K_a$ radiation. The compound was crystallized in the monoclinic space group $P2_{1/c}$ with a=13.781(3), b=9.035(l), c=17.699(3) ${\AA}$, and ${\beta}=111.93(l)^{\circ}$. An X-ray crystal structure of complex 1 showed a short N(2)-N(3) distance ($1.265 {\AA}$) consistent with the valence tautomer A with Ir(III) rather than Ir(I). All complexes are highly colored and decompose on irradiation at 254 nm. Electrochemical studies show that complex 1 displays a quasi-reversible reduction.

폴리프로필렌에 UV 흡수제를 갖는 말레이미드의 용융그래프팅 (Thermal Melt Grafting of Maleimides Having UV-absorber onto Polypropylene)

  • 김택현;나혜선
    • 폴리머
    • /
    • 제38권1호
    • /
    • pp.49-53
    • /
    • 2014
  • 새로운 단량체형의 자외선흡수제를 triethylamine에서 2,4-dihydroxybenzophenone과 N-4-chlorocarbonyl-phenylmaleimide의 반응을 통하여 합성하였다. 이 자외선흡수제를 폴리프로필렌에 용융반응에 의해 그래프팅하였다. Maleimide의 그래프팅 수율은 IR 분광 데이터를 이용하여 결정하였다. 용융반응의 최적조건을 구하기 위하여 반응온도 및 시간, 단량체의 농도의 변화에 대하여 그래프팅 수율을 구하였다. Weatherometer에서 IR 스펙트럼의 카보닐 지수를 이용하여 그래프트된 폴리프로필렌의 광산화 정도를 조사하였으며, 우수한 광산화 억제작용을 보였다.

Synthesis and Crystal Structure of Blue Phosphorescent mer-Tris(2',6'-difluoro-2,3'-bipyridinato-N,C4') Iridium(III)

  • Jung, Na-Rae;Lee, Eun-Ji;Kim, Jin-Ho;Park, Hyoung-Keun;Park, Ki-Min;Kang, Young-Jin
    • Bulletin of the Korean Chemical Society
    • /
    • 제33권1호
    • /
    • pp.183-188
    • /
    • 2012
  • A blue phosphorescent $Ir(dfpypy)_3$ (dfpypy:fluorinated pyridine-pyridine ligand) complex with meridional configuration has been synthesized by newly developed effective method and its solid state structure and photoluminescence are characterized. For this complex, mer-$Ir(dfpypy)_3$, the glass-transition and decomposition temperatures appear at $160^{\circ}C$ and $384^{\circ}C$ respectively in TGA and DSC experiments, which indicates that this complex has high thermal stability. In a crystalline structure, an average Ir-C bond length of mer-$Ir(dfpypy)_3$ is slightly longer than that of fac-$Ir(dfpypy)_3$, which assumed to be due to the weak trans-influence. The absorption and emission spectra are observed more red-shifted in mer-$Ir(dfpypy)_3$ than fac-$Ir(dfpypy)_3$. In addition, the former is readily oxidized than the latter in electrochemical behavior.

RF-PACVD를 이용한 Hydrogenated Carbon Nitride박막의 합성 및 특성에 관한 연구 (Study on characterization of hydrogenated carbon nitride thin films prebared by Plasma-Assisted Chemical Vapor Deposition)

  • 이철화;김병수;박구범;이상희;진윤영;이덕출
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 1998년도 추계학술대회 논문집 학회본부 C
    • /
    • pp.856-857
    • /
    • 1998
  • Hydrogenated amorphous carbon nitride [a-C:H(N)] films were deposited on pretreated silicon(100) substrate in activated gas phase using. RF plasma-assisted CVD. We measured the FT-IR spectrum to investigate $C{\equiv}N$ stretching mode(nitrile), C-H stretching mode, C-H bending mode, C=C stretching mode C=N(imino) mode, and the EDX to investigate the ratio of N to C(0.25). By the results of FT-IR and EDX spectrum, We confirmed that hydrogenated amorphous carbon nitride films successfully were synthesized by RF-PACVD

  • PDF

Synthesis of N-doped Ethylcyclohexane Plasma Polymer Thin Films with Controlled Ammonia Flow Rate by PECVD Method

  • Seo, Hyunjin;Cho, Sang-Jin;Boo, Jin-Hyo
    • Applied Science and Convergence Technology
    • /
    • 제23권1호
    • /
    • pp.44-47
    • /
    • 2014
  • In this study, we investigated the basic properties of N-doped ethylcyclohexene plasma polymer thin films that deposited by radio frequency (13.56 MHz) plasma-enhanced chemical vapor deposition (PECVD) method with controlled ammonia flow rate. Ethylcyclohexene was used as organic precursor with hydrogen gas as the precursor bubbler gas. Additionally, ammonia ($NH_3$) gas was used as nitrogen dopant. The as-grown polymerized thin films were analyzed using ellipsometry, Fourier-transform infrared [FT-IR] spectroscopy, UV-Visible spectroscopy, and water contact angle measurement. We found that with increasing plasma power, film thickness is gradually increased while optical transmittance is drastically decreased. However, under the same plasma condition, water contact angle is decreased with increasing $NH_3$ flow rate. The FT-IR spectra showed that the N-doped ethylcyclohexene plasma polymer films were completely fragmented and polymerized from ethylcyclohexane.

주짓수 선수의 허리 통증 유무에 따른 엉덩관절 돌림 가동범위 비교 (Comparison of Hip Rotation Range of Motion in Jiu-Jitsu Athletes With and Without Low Back Pain)

  • 양성준;박규남;경문수;김시현
    • 한국전문물리치료학회지
    • /
    • 제25권1호
    • /
    • pp.47-52
    • /
    • 2018
  • Background: A limited hip rotational range of motion (ROM) has been considered to be one of characteristics of low back pain (LBP) in athletes. Although LBP frequently occurs in jiu-jitsu athletes, no previous has compared hip rotational ROM between jiu-jitsu athletes with and without LBP. Objects: The aim of the study was to compare ROM for hip internal rotation (IR) and external rotation (ER), and total hip rotation between jiu-jitsu athletes with and without LBP. Methods: Jiu-jitsu athletes were recruited for the LBP group ($n_1=15$) and control group without LBP ($n_2=15$). IR, ER, and total rotational range of hip joint were measured using a goniometer. Analysis of variance was used to compare the ROM between groups and sides. Results: The LBP group showed a significantly lower range of passive hip IR, passive total rotation, active IR, active ER, and active total rotation than the control group (p<.05). Dominant side of passive hip IR and active IR had a significantly lower ROM than non-dominant side (p<.05). In passive ER ROM, non-dominant side was significantly greater than dominant side (p<.05). Conclusion: Compared to jiu-jitsu athletes without LBP, athletes with LBP exhibit a loss of hip rotational ROM. Based on these results, clinicians and athletic trainers should measure hip rotational ROM when designing the management plan for jiu-jitsu athletes with LBP.