• Title/Summary/Keyword: Wilkinson

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Catalytic and Stoichiometric Hydroacylation of Olefin Derivatives with 8-Quinolinecarboxaldehyde by Rh(I)

  • Jun, Chul-Ho;Han, Jong-Soo;Kang, Jung-Bu;Kim, Sun-Il
    • Bulletin of the Korean Chemical Society
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    • v.15 no.3
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    • pp.204-209
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    • 1994
  • Catalytic hydroacylation has been achieved by the reaction of 8-quinolinecarboxaldehyde (1) and various vinyl derivatives such as 2a, 2b and 2c with Wilkinson's complex (3) to give linear alkyl ketones, 4a, 4b and 4c, respectively. However, stoichiometric ligand-promoted hydroacylation of 2a and 2b with [$(C_8H_{14})_2RhCl]_2$ (5) resulted in a mixture of the branched alkyl ketones and the linear alkyl ketones in different ratios. Stoichiometric hydroacylation of some other olefin derivatives such as 6, 11, 12 and 26, produced functionalized alkyl ketone compounds.

Hydroiminoacylation of $\alpha,\omega$-diene with Aldimine by Rh(Ⅰ) and Isomerization of the Terminal Olefin to the Internal Olefin

  • Jun, Chul-Ho;Kang, Jung-Bu;Lim, Yeong-Gweon
    • Bulletin of the Korean Chemical Society
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    • v.14 no.2
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    • pp.287-291
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    • 1993
  • Catalytic iminohydroacylation has been achieved by the reaction of aldimine 1 and 1,5-hexadiene (2a) with Wilkinson's complex as catalyst. Compounds 7a, 8a and 9a were obtained as final product after hydrolysis of the resulting iminohydroacylation products 4a, 5a and 6a. Depending on the reactant ratio (2/1), the ratio of products were changed dramatically : As the 2/1 ratio was increased, 7a is the major product after hydrolysis while 8a is the major with an 1/1 ratio of 2/1. The mechanism of the formation of 5a is determined by the reaction of 1 and 2b under the identical reaction conditions. Considering that 5a may not be formed from the hydroiminoacylation of 14a since 5b cannot be formed from that of conjugate diene 14b generated from isomerization of 2b, 5a must be formed from the reaction of 4a and 10 by addition-elimination mechanism.

Hydroiminoacylation of Allyl and Homoallyl Alcohol Derivatives with Benzalimide and Solvolysis of Hydroacylated Products

  • 홍준배;전철호
    • Bulletin of the Korean Chemical Society
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    • v.16 no.4
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    • pp.363-369
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    • 1995
  • Hydroiminoacylations of allyl and homoallyl alcohol and their derivatives with benzaldimine by Wilkinson's complex have been studied. All these terminal alkene derivatives except allyl alcohol were hydroacylated according to anti-Markownikoff's rule to give the corresponding linear alkyl compounds without showing oxygen directing effect, even though hydroiminoacylation of 3-acetoxy-1,5-hexadiene showed strong allyloxy directing effect over homoallyloxy directing effect in a 92:8 ratio. Solvolysis of 4-acetoxy-1-phenylbutan-1-one, previously prepared by hydroiminoacylation, in ethanol led to etherification giving 4-ethoxy-1-phenylbutan-1-one through neighbouring group participation, while that of 5-acetoxy-1-phenylpentan-1-one led to common transesterification giving 5-hydroxy-1-phenylpentan-1-one. Application of branched alkanols such as isopropanol and t-butanolin solvolysis of 4-acetoxy-1-phenylbutan-1-one underwent competition between etherification and transesterification.

GLP Bioanalysis from the US FDA Perspective

  • Wilkinson, Tames M.
    • Proceedings of the Korean Society of Toxicology Conference
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    • 2006.11a
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    • pp.75-79
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    • 2006
  • The United States Food and Drug Administration is responsible for ensuring US residents receive safe and effective medicines. Since blood levels of drugs are correlated with pharmacological effect, FDA closely regulates how those blood levels are measured. The FDA has established requirements for bioanalytical analyses such as minimum method validation, SOP, and reporting criteria. The FDA also has standards for computer validation which must be followed to ensure the data are reliable. Data presented to the Agency are scrutinized to ensure they are accurate and a true reflection of the raw data generated in a study. To verify the quality of data, FDA has developed an inspection program. The specific requirements of the FDA related to bioanalysis will be discussed.

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Yearly Variation and Stability of Yield Characters in Rice Varieties Released in Different fears (육성연대가 다른 벼 품종들의 수량형질 연차간 변이와 안정성)

  • 이점호;정국현;김홍열;양세준;최해춘
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.45 no.6
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    • pp.361-365
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    • 2000
  • This study was carried out to evaluate yearly variation and stability of yield and yield components of fifteen rice varieties. Yield stability and universal variety parameter of rice varieties were utilized for statistical model developed by Stroike, Grafius, and Finlay respectively. The lowest yearly variation based on coefficient of variation was found in Dasanbyeo for number of panicles/hill, in Jodongji for number of grains/panicle, in Yongmoonbyeo for ripened grain ratio, in Nagdongbyeo for 1,000 grain weight, and in Dasanbyeo for grain yield. Stability analysis by Stroike and Johnson's model revealed that Ilpumbyeo, Hwaseongbyeo, Dongjinbyeo in Japonica type, and And-abyeo and Dasanbyeo in Tongil type had the higher stability above average. Universal varieties analyzed by Grafius model were Ilpumbyeo, Dongjinbyeo, Hwaseongbyeo, Nagdongbyeo, and Jodongji in Japonica, and Dasanbyeo and Samgangbyeo in Tongil type. Damageum, Dongjinbyeo, Hwaseongbyeo and Ilpumbyeo in Japonica, and Dasanbyeo and Yongmoonbyeo in Tongil type were found to be highly stable as analyzed by Finlay & Wilkinson's model. In conclusion, with reference to both grain yield and stability based on above three methods, Ilpumbyeo, Hwaseongbyeo, and Dongjinbyeo in Japonica, and Dasanbyeo in Tongil type were evaluated to be highly year-stable and high-yielding.

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Design of 2nd-harmonic Quadrature Mixer for Ultra Wideband(UWB) Systems (2차 고조파를 이용한 UWB 시스템용 쿼드러쳐 혼합기 설계)

  • Jung, Goo-Young;Lim, Jong-Hyuk;Choi, Byung-Hyun;Yun, Tae-Yeoul
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.17 no.12 s.115
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    • pp.1156-1163
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    • 2006
  • This paper presents an ultra wideband(UWB) direct conversion mixer for IEEE 802.15.3a applications with simulation and measurement results. Since the direct conversion mixing causes dc-offset and even-order distortion, the proposed mixer adopts an anti-parallel diode pairs(APDPs) to solve these problems. The proposed mixer consists of an in-phase wilkinson power divider over $3.1{\sim}4.8GHz$, a wideband $45^{\circ}$ power divider over $1.5{\sim}2.4GHz$, and miniatured band pass filters(BPFs) for RF-LO isolations. The conversion loss is optimized with impedance matchings between APDPs and wideband components. The measured mixer shows the conversion loss of 13.5 dB, input third-order intercept-point($IIP_3$) of 7 dBm, and 1-dB gam compression point($P_{1dB}$) of -4 dBm. Quadrature(I/Q) outputs have the magnitude difference of about 1 dB and phase difference of ${\pm}3^{\circ}$.

Design of a 1 × 2 Array Microstrip Antenna for Active Beam Compensation at X-band (X-밴드 능동적 빔 보상 1 × 2 배열 마이크로스트립 안테나 설계)

  • Choi, Yoon-Seon;Woo, Jong-Myung
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.15 no.2
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    • pp.111-118
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    • 2016
  • This paper presents an X-band (9.375 GHz) $1{\times}2$ array microstrip antenna which is capable of active beam compensation for installation of an unmanned aerial vehicle (UAV). First of all, a basic $1{\times}2$ array microstrip antenna incorporated with wilkinson power divider was designed and performance of the array antenna was verified. Next, to verify beam steering performance of the designed array microstrip antenna, we fabricated a phase shifter, and the wilkinson power divider as module structure and measured characteristics of beam steering according to phase shifting. The main lobe is 0.6 dBi at $0^{\circ}$, and the side lobe decreased 18.8 dB. The reliable radiation pattern was achieved. Finally, an active beam steering microstrip array antenna attached with the phase shifter and the power divider on the back side of the antenna was designed and fabricated to install wing of UAV for compactness. The maximum gain is 0.1 dBi. Therefore, we obtained a basic antenna technology for compensating beam error according to wing deformation of an UAV installed array antennas.

New UWB 1:2 Power Divider with Flat In-Band Splitting and Bandpass Filtering Functions

  • Duong, Thai Hoa;Kim, Ihn-Seok
    • Journal of electromagnetic engineering and science
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    • v.10 no.1
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    • pp.28-34
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    • 2010
  • This paper introduces a new U.S. ultra-wideband(UWB: 3.1~10.6 GHz) 1:2 power divider based on a single section Wilkinson type configuration. The divider provides very flat in-band power splitting, high isolation, low insertion loss, sharp roll-off bandpass filtering, and DC blocking characteristics. The circuit consists of a $\lambda$/4 Y resonator, three capacitively coupled $\lambda$/2 short-circuited lines, and a resistor between the two output ports. The circuit structure was simulated with ADS and HFSS, and realized with low-temperature co-fired ceramic(LTCC) green tape, which has a dielectric constant of 7.8. $|S_{11}|$ better than 10 dB, $|S_{21}|$ and $|S_{31}|$ less than 3.2 dB, with both $|S_{22}|$ and $|S_{32}|$ measured as better than 12 dB for the whole UWB band. Measurement results agree closely with HFSS simulation results. The power divider has a compact size of $4\times9\times0.6mm^3$.

Design and fabrication on 2.7-2.9 GHz, 1.5 kW pulsed Solid state power amplifier (1.5 kW, 2.7-2.9 GHz, 반도체 펄스 전력 증폭기 설계 및 제작)

  • Jang, S.M.;Choi, G.W.;Joo, J.H.;Choi, J.J.;Park, D.M.
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2005.11a
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    • pp.91-96
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    • 2005
  • In this paper, describes the design and performance of a 1.5 kW solid-state pulsed power amplifier, operating over 2.7-2.9 GHz at a duty of 10% and with a pulse width of 100 us for radar application. The solid-state pulsed power amplifier configures a series of 8-stage cascaded power amplifier with different RF output power levels. Low loss Wilkinson combiners are used to combine output powers of six 300W high power solid state modules. Tests show peak output power of 1.61 kW, corresponding to PAE of 26.2% over 2.7-2.9 GHz with pulse width of 100 us and a PRF of 1 kHz.

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Dual-Band Stop Filter Using Metamaterial TLs (Metamaterial 전송선을 이용한 이중 대역 저지 필터)

  • Oh, Hee-Seok;Nam, Sang-Wook
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.20 no.2
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    • pp.124-128
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    • 2009
  • This raper proposes a dual-bandstop filter, which is based on a metamaterial transmission line using the composite right/left-handed (CRLH) and dual composite right/left-handed (D-CRLH) structures. The metamaterial structure is used for miniaturization and dual-bandstop operation at the TDMB frequency range (195 MHz) and DVB-T/H frequency range (670 MHz). The size of the proposed filter is $30{\times}15\;mm$, and the -10 dB bandstop fractional bandwidth is approximately 73 % and 50 % at each frequency, respectively.