• Title, Summary, Keyword: BR

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Synthesis of 5-bromouracil-$Br^{82}$ by Isotopic Exchange Method (Isotopic Exchange 에 依한 5-bromouracil-$Br^{82}$의 合成)

  • Pyun, Hyung-Chick;Kim, Jae-Rock
    • Journal of the Korean Chemical Society
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    • v.8 no.2
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    • pp.39-42
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    • 1964
  • As the bromination method with $Br_2^{82}$ for the synthesis of 5-bromouracil-$Br^{82}$ gave products with considerable impurities, e. g. uracil etc. an attempt to produce pure one by isotopic exchange method was performed. Bromide-82 ion such as $NH_4Br^{82}$ or $HBr^{82}$ undergoes no isotopic exchange with 5-bromouracil-Br. However, isotopic exchange between $NH_4Br^{82}$ and $Br_2$, and between $Br_2^{82}$ and 5-bromouracil-Br were too fast to determine the rate. The result indicated that this method can be used in the production of pure 5-bromouracil-$Br^{82}$. It was also found that the use of reducing agent to maintain $Br^{82}$ as bromide form was unnecessary on $NH_4Br^{82}$ production from reactor.

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A Study on the Friction and Anti-abrasion Properties of Rubber Blends for Shoes Outsole (신발 밑창용 고무 블렌드물의 마찰 및 내마모 특성에 대한 연구)

  • Pyo, Kyung-Duk;Park, Cha-Cheol
    • Elastomers and Composites
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    • v.46 no.4
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    • pp.324-328
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    • 2011
  • Blends were prepared by mixing BR, SBR and NBR to CIIR, which is used for outsole, at various mixing ratio, and effect of the mixing ratio on abrasion resistance and coefficient of friction was analyzed. CIIR interferes the crystalline formation of BR in BR/CIIR blends and this could be one of the factors that rapidly decreases abrasion resistance of BR/CIIR blends. $Tan{\delta}$ peak area of CIIR/BR blends decreased as the amount of BR present in the blends increased, and similarly, the coefficient of friction tended to decrease. Stress relaxation rate and rebound resilience of CIIR/BR blends decreased with increasing BR content, and it was presumed that their rebound resilience was affected by stress relaxation rate.

Influence of Initial States of Test Sheets on Adhesion of NR/NR, BR/BR, and NR/BR (시험편의 초기 상태가 NR/NR, BR/BR, 그리고 NR/BR 접착에 미치는 영향)

  • Choi, Sung-Seen;Kim, Jong-Chul;Woo, Chang-Su
    • Elastomers and Composites
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    • v.42 no.2
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    • pp.107-111
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    • 2007
  • Adhesion of NR and BR composites with different initial states of precured or uncured conditions was studied. Adhesion between the NR and BR sheets as well as adhesion between the same rubber sheets was investigated. Adhesion forces of the uncured/uncured specimens were larger than those of the cured/uncured and cured/cured ones. The cured/cured samples and uncured NR/cured BR specimen were fully peeled out by the peel test. When one sheet was broken during the peel test, the sheet having the higher crosslink density was broken irrespective of the rubber types. Adhesion forces of the same rubber sheets were higher than those of the different ones and adhesion force of the cured NR/uncured BR sample was higher than that of the uncured NR/cured BR one. The experimental results were explained with the crosslink density and interdiffusion of rubber chains.

Photodissociation of C3H5Br and C4H7Br at 234 nm

  • Kim, Hyun-Kook;Paul, Dababrata;Hong, Ki-Ryong;Cho, Ha-Na;Lee, Kyoung-Seok;Kim, Tae-Kyu
    • Bulletin of the Korean Chemical Society
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    • v.33 no.1
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    • pp.143-148
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    • 2012
  • The photodissociation dynamics of cyclopropyl bromide ($C_3H_5Br$) and cyclobutyl bromide ($C_4H_7Br$) at 234 nm was investigated. A two-dimensional photofragment ion-imaging technique coupled with a [2+1] resonanceenhanced multiphoton ionization scheme was utilized to obtain speed and angular distributions of the nascent $Br(^2P_{3/2})$ and $Br^*(^2P_{1/2})$ atoms. The recoil anisotropies for the Br and $Br^*$ channels were measured to be ${\beta}_{Br}=0.92{\pm}0.03$ and ${\beta}_{Br^*}=1.52{\pm}0.04$ for $C_3H_5Br$ and ${\beta}_{Br}=1.10{\pm}0.03$ and ${\beta}_{Br^*}=1.49{\pm}0.05$ for $C_4H_7Br$. The relative quantum yield for Br was found to be ${\Phi}_{Br}=0.13{\pm}0.03$ and for $C_3H_5Br$ and $C_4H_7Br$, respectively. The soft radical limit of the impulsive model adequately modeled the related energy partitioning. The nonadiabatic transition probability from the 3A' and 4A' potential energy surfaces was estimated and discussed.

Growth and Scintillation Characteristics of CsI(Br) Single Crystals (CsI(Br) 단결정의 육성과 섬광특성)

  • Oh, M.Y.;Jung, Y.J.;Lee, W.G.;Doh, S.H.;Kang, K.J.;Kim, D.S.;Kim, W.;Kang, H.D.
    • Journal of Sensor Science and Technology
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    • v.9 no.5
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    • pp.341-349
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    • 2000
  • CsI(Br) single crystals doped with 1, 3, 5 or 10 mole% $Br^-$ ions, as an activator, were grown by Czochralski method. The lattice structure of grown CsI(Br) single crystal was bcc and its lattice constant was $4.568\;{\AA}$. The absorption edge of the CsI(Br) single crystals was observed at 243 nm. The spectral range of the luminescence excited by 243 nm of wavelength was $300{\sim}600\;nm$, and its peak emission appeared at 440 nm. The luminescence intensity was maximum when CsI(Br) was doped with 3 mole % $Br^-$ ions. The energy resolutions of the CsI(Br) scintillator doped with 3 mole % $Br^-$ ions were 15.0% for $^{137}Cs$(662 keV), 13.1% for $^{54}Mn$(835 keV), and 18.0% and 6.3% for $^{22}Na$(511 keV and 1275 keV), respectively. The decay curves had fast and slow components, and the fast component was about 41 ns independent on the concentration of the $Br^-$ ions. The time resolution of CsI(Br) scintillators decreased with increasing of the concentration of $Br^-$ ions.

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A Study on Improvement of the Physical Properties of 4 Component Working Fluid in Gas Fired Absorption Chillers (가스흡수식 냉방기용 4성분계 작동매체의 물성 향상 연구)

  • Baek, Young-Soon;Oh, Young-Sam;Lee, Yong-Won;Park, Dal-Ryung;Koo, Ki-Kap
    • Applied Chemistry for Engineering
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    • v.10 no.3
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    • pp.400-406
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    • 1999
  • In an effort to obtain high efficiency in gas fired absorption chillers, a new working fluid has been developed with thc addition of the component of $LiNO_3$, LiCl and LiI to the conventional solution of $LiBr-H_2O$. The solubility and vapor pressure of the 4 component working fluid developed in this work were measured and compared to the results of $LiBr-H_2O$ solution. It was observed that there exists an optimal mole ratio of the inorganic salts in terms of solubility. The mole ratio of LiBr, $LiNO_3$ and LiCl was found to be around 5:1:1~2 in the $LiBr-LiNO_3-LiCl-H_2O$ mixture, and in the case of $LiBr-LiO_3-Lil-H_2O$ and $LiBr-Lil-LiCl-H_2O$ mixtures, the mole ratio of LiBr, $LiNO_3$ and Lil/ LiBr, LiI and LiCl were found to be around 5:1:1 and 5:1:0.5~1 respectively. The vapor pressure of the 4 component working fluid of the optimal mole ratio was increascd with adding the component of $LiNO_3$, LiCl and LiI except for $LiBr-LiNO_3-LiCl-H_2O$ mixture. The absorption capacity of $LiBr-LiNO_3-LiCl-H_2O$ mixture was obtained higher than that of $LiBr-H_2O$ mixture.

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A Study on Friction-induced Surface Fracture Behaviors of Thermoplastic Polyurethane (TPU)/Rubber Blends (열가소성 폴리우레탄 (TPU)/고무 블렌드의 마찰에 의한 표면 파괴 거동)

  • Jeon, Jun-Ha;Park, Sang-Min;Um, Gi-Yong;Bea, Jong-Woo
    • Journal of Adhesion and Interface
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    • v.14 no.3
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    • pp.121-127
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    • 2013
  • In this work, the thermoplastic polyurethane (TPU) was melt-blended with EPDM, NBR and BR to form TPU/Rubber blend films, their composition and friction-induced surface fracture relationship was investigated. TPU/EPDM and TPU/BR blends exhibited the improved friction-induced surface fracture, especially the effect of BR was excellent. With addition of more than 10 wt% BR, TPU/BR blends exhibited the improved friction-induced surface fracture. The increase of the soft segment with increasing BR content, which was confirmed by scanning electron microscopy (SEM) analysis enabled us to estimate the improved friction-induced surface fracture.

The Complex Formation of Gallium Bromide with i-Butyl Bromide in Nitrobenzene) (니트로벤젠용액내에서의 브롬화갈륨과 i-브롬화부틸과의 착물형성에 관한 연구)

  • Gwon, O Cheon;NamGung, Jin Hui;Choe, Gi Jun
    • Journal of the Korean Chemical Society
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    • v.38 no.3
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    • pp.208-213
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    • 1994
  • The solubility of i-butyl bromide in nitrobenzene have been measured at 19, 25 and $40^{\circ}C$ in the presence and absence of gallium bromide. In the presence of gallium bromide, 1 : 1 complex, $i-C_4H_9Br{\cdot}GaBr_3$ is formed in the solution. The instability constant K of the complex formation was evaluated from the following equilibrium equation. $i-C_4H_9Br{\cdot}GaBr_3{\rightleftharpoons}C_4H_9Br + 1/2Ga_2Br_6.$ From these result, it seems that the stabilities of the complex formation, gallium bromide with alkyl bromide, are directly related with those of the carbonium ions of alkyl bromide.

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Vibration-Vibration Energy Transfer between $H^{79}Br\;and\;H^{81}Br$ ($H^{79}Br$$H^{81}Br$간의 진동 ${\to}$ 진동에너지 이동)

  • Chang Soon Lee;Yoo Hang Kim;Hyung Kyu Shin
    • Journal of the Korean Chemical Society
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    • v.28 no.6
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    • pp.361-365
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    • 1984
  • The long-lived collision model has been applied to the resonant vibration-vibration energy exchange process $H^{79}$Br(v = 1) + $H^{81}Br$(v = 0) ${\to}$ $H^{79}Br$(v = 0) + $H^{81}Br$(v = 1) + ${\Delta}E\;=\;0.38 cm^{-1}$ The energy exchange probabilities have been calculated over the temperature range from 200 to 800K. They show negative temperature dependence (P ${\propto}\;T^{-1.8}$) and agree with the available experimental data better than those calculated from other theories.

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Anatomical study on The Arm Greater Yang Small Intestine Meridian Muscle in Human (수태양소장경근(手太陽小腸經筋)의 해부학적(解剖學的) 연구(硏究))

  • Park, Kyoung-Sik
    • Journal of Pharmacopuncture
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    • v.7 no.2
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    • pp.57-64
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    • 2004
  • This study was carried to identify the component of Small Intestine Meridian Muscle in human, dividing the regional muscle group into outer, middle, and inner layer. the inner part of body surface were opened widely to demonstrate muscles, nerve, blood vessels and the others, displaying the inner structure of Small Intestine Meridian Muscle. We obtained the results as follows; 1. Small Intestine Meridian Muscle is composed of the muscle, nerve and blood vessels. 2. In human anatomy, it is present the difference between a term of nerve or blood vessels which control the muscle of Meridian Muscle and those which pass near by Meridian Muscle. 3. The inner composition of meridian muscle in human arm is as follows ; 1) Muscle ; Abd. digiti minimi muscle(SI-2, 3, 4), pisometacarpal lig.(SI-4), ext. retinaculum. ext. carpi ulnaris m. tendon.(SI-5, 6), ulnar collateral lig.(SI-5), ext. digiti minimi m. tendon(SI-6), ext. carpi ulnaris(SI-7), triceps brachii(SI-9), teres major(SI-9), deltoid(SI-10), infraspinatus(SI-10, 11), trapezius(Sl-12, 13, 14, 15), supraspinatus(SI-12, 13), lesser rhomboid(SI-14), erector spinae(SI-14, 15), levator scapular(SI-15), sternocleidomastoid(SI-16, 17), splenius capitis(SI-16), semispinalis capitis(SI-16), digasuicus(SI-17), zygomaticus major(Il-18), masseter(SI-18), auriculoris anterior(SI-19) 2) Nerve ; Dorsal branch of ulnar nerve(SI-1, 2, 3, 4, 5, 6), br. of mod. antebrachial cutaneous n.(SI-6, 7), br. of post. antebrachial cutaneous n.(SI-6,7), br. of radial n.(SI-7), ulnar n.(SI-8), br. of axillary n.(SI-9), radial n.(SI-9), subscapular n. br.(SI-9), cutaneous n. br. from C7, 8(SI-10, 14), suprascapular n.(SI-10, 11, 12, 13), intercostal n. br. from T2(SI-11), lat. supraclavicular n. br.(SI-12), intercostal n. br. from C8, T1(SI-12), accessory n. br.(SI-12, 13, 14, 15, 16, 17), intercostal n. br. from T1,2(SI-13), dorsal scapular n.(SI-14, 15), cutaneous n. br. from C6, C7(SI-15), transverse cervical n.(SI-16), lesser occipital n. & great auricular n. from cervical plexus(SI-16), cervical n. from C2,3(SI-16), fascial n. br.(SI-17), great auricular n. br.(SI-17), cervical n. br. from C2(SI-17), vagus n.(SI-17),hypoglossal n.(SI-17), glossopharyngeal n.(SI-17), sympathetic trunk(SI-17), zygomatic br. of fascial n.(SI-18), maxillary n. br.(SI-18), auriculotemporal n.(SI-19), temporal br. of fascial n.(SI-19) 3) Blood vessels ; Dorsal digital vein.(SI-1), dorsal br. of proper palmar digital artery(SI-1), br. of dorsal metacarpal a. & v.(SI-2, 3, 4), dorsal carpal br. of ulnar a.(SI-4, 5), post. interosseous a. br.(SI-6,7), post. ulnar recurrent a.(SI-8), circuirflex scapular a.(SI-9, 11) , post. circumflex humeral a. br.(SI-10), suprascapular a.(SI-10, 11, 12, 13), first intercostal a. br.(SI-12, 14), transverse cervical a. br.(SI-12,13,14,15), second intercostal a. br.(SI-13), dorsal scapular a. br.(SI-13, 14, 15), ext. jugular v.(SI-16, 17), occipital a. br.(SI-16), Ext. jugular v. br.(SI-17), post. auricular a.(SI-17), int. jugular v.(SI-17), int. carotid a.(SI-17), transverse fascial a. & v.(SI-18),maxillary a. br.(SI-18), superficial temporal a. & v.(SI-19).