금강경 한역제본에 대한 연구

이건준 보조사상연구원 1998 九山論集 Vol.2 No.-

Inactivation of Escherichia coli, Saccharomyces cerevisiae, and Lactobacillus brevis in Low-fat Milk by Pulsed Electric Field Treatment: A Pilot-scale Study

이건준,한복궁,최혁준,강신호,백승천,이동운 한국축산식품학회 2015 한국축산식품학회지 Vol.35 No.6

We investigated the effects of a pulsed electric field (PEF) treatment on microbial inactivation and the physical properties of low-fat milk. Milk inoculated with Escherichia coli, Saccharomyces cerevisiae, or Lactobacillus brevis was supplied to a pilot-scale PEF treatment system at a flow rate of 30 L/h. Pulses with an electric field strength of 10 kV/cm and a pulse width of 30 µs were applied to the milk with total pulse energies of 50-250 kJ/L achieved by varying the pulse frequency. The inactivation curves of the test microorgan- isms were biphasic with an initial lag phase (or shoulder) followed by a phase of rapid inactivation. PEF treatments with a total pulse energy of 200 kJ/L resulted in a 4.5-log reduction in E. coli, a 4.4-log reduction in L. brevis, and a 6.0-log reduction in S. cerevisiae. Total pulse energies of 200 and 250 kJ/L resulted in greater than 5-log reductions in microbial counts in stored PEF-treated milk, and the growth of surviving microorganisms was slow during storage for 15 d at 4℃. PEF treatment did not change milk physical properties such as pH, color, or particle-size distribution (p<0.05). These results indicate that a relatively low electric-field strength of 10 kV/cm can be used to pasteurize low-fat milk.

Correlation Between Microstructural and Optical-Diffraction Properties in Femtosecond-Laser-Induced Gratings of Amorphous Co2MnSi Film

이건준,윤종승,김전,김정훈,이영백 한국물리학회 2006 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.48 No.6

We studied the correlation between the microstructures and the optical diffraction properties in femtosecond-laser-induced gratings of an amorphous Co2MnSi (a-Co2MnSi) film. The a-Co2MnSi thin film was deposited on a glass substrate by using magnetron sputtering, and the crystallization of the a-Co2MnSi film was performed using two-beam interference of near-infrared femtosecondlaser pulses. For the femtosecond-laser-interference crystallization using two 120-μJ laser beams, the diffraction intensity slowly increased with the laser shot count until it reached a maximum intensity around 25900 laser shots; then, the diffraction intensity gradually decreased. From the cross-sectional and the plan-view transmission-electron-microscopy images of the laser-crystallized Co2MnSi regions, the crystallization reached deeper into the sample film under an optimized fluence condition. Meanwhile, a lower fluence beam resulted in a partially crystallized film, and a higher fluence beam made a partially damaged film. The femtosecond-laser-induced gratings consisted of alternating semicrystalline-Co2MnSi and polycrystalline-Co2MnSi bands with a period of about 2-μm.

Femtosecond Laser Surface Structuring of Amorphous and Crystalline Silicon

이건준,오차환,윤종승,김은규,정현식,장진,손용덕,이영백 한국물리학회 2006 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.48 No.6

The surface structuring of amorphous and crystalline silicon was performed by using femtosecondlaser- induced phase transformations: i) amorphous-to-crystalline and ii) crystalline-to-amorphous. The amorphous silicon (a-Si) films were prepared on glass substrates by using plasma-enhanced chemical-vapor deposition. Two kinds of micropatterns were produced in the a-Si films: i) a twodimensional (2D) pattern (a word ‘q-Psi’) was produced by using the inverse Fourier transform of a computer-generated hologram, and ii) laser-induced gratings (LIGs) were made by means of two-beam interference of near-infrared femtosecond-laser pulses. By using micro-Raman spectroscopy, optical microscopy, scanning electron microscopy, and transmission electron microscopy, the femtosecond-laser pulses were found to induce a localized phase transformation from the amorphous to the crystalline phase, and the spatially-selected crystallization of a-Si was found to be responsible for the formation of patterns such as the LIG and the 2D pattern. Crystalline silicon (c-Si) with a SiO2 capping layer was also periodically modified by femtosecond holography. A micro- Raman study indicated that the LIG formation in c-Si could be ascribed to the spatially-selected amorphization of c-Si. The surface structuring of amorphous and crystalline silicon was performed by using femtosecondlaser-induced phase transformations: i) amorphous-to-crystalline and ii) crystalline-to-amorphous. The amorphous silicon (a-Si) films were prepared on glass substrates by using plasma-enhanced chemical-vapor deposition. Two kinds of micropatterns were produced in the a-Si films: i) a twodimensional (2D) pattern (a word ‘q-Psi’) was produced by using the inverse Fourier transform of a computer-generated hologram, and ii) laser-induced gratings (LIGs) were made by means of two-beam interference of near-infrared femtosecond-laser pulses. By using micro-Raman spectroscopy, optical microscopy, scanning electron microscopy, and transmission electron microscopy, the femtosecond-laser pulses were found to induce a localized phase transformation from the amorphous to the crystalline phase, and the spatially-selected crystallization of a-Si was found to be responsible for the formation of patterns such as the LIG and the 2D pattern. Crystalline silicon (c-Si) with a SiO2 capping layer was also periodically modified by femtosecond holography. A microRaman study indicated that the LIG formation in c-Si could be ascribed to the spatially-selected amorphization of c-Si.

범본 금강경류의 판본에 대한 연구

이건준 보조사상연구원 2000 九山論集 Vol.4 No.-

고조파 억압을 위한 병렬 궤환형 발진기와 주파수 체배기

이건준,고정필,김영식,Lee, Kun-Joon,Ko, Jung-Pil,Kim, Young-Sik 한국통신학회 2005 韓國通信學會論文誌 Vol.30 No.2a

본 논문에서는 고조파 억압 특성 개선을 위한 저잡음 병렬 궤환형 발진기 (Parallel feedback oscillator)와 주파수 체배기 (frequency doubler)를 설계 및 제작하였다. 주파수 체배를 위한 발진기의 기본 주파수를 유전체 공진기 (DR: Dielectric Resonator) 여파기와 능동소자 사이에서 얻음으로써 불요 고조파를 현저히 억압하였다. 발진기의 기본 주파수 신호는 고조파 신호를 억압하기 위한 부가적인 대역 통과 여파기가 필요치 않으며 곧바로 주파수 체배기의 입력단으로 인가되어 주파수 체배기의 입력 정합 회로가 간단하다. 측정된 발진기의 고조파 억압 특성은 -47.7 dBc이고 주파수 체배기를 이용하였을 때 24.0 GHz 에서의 기본 주파수 억압 특성은 -37.5 dBc이다. 위상 잡음 특성은 중심 주파수에서 10 KHz와 100 KHz 떨어진 곳에서 각각 -80.3 dBc/Hz와 -93.5 dBc/Hz이다. In this paper, a low noise parallel feedback oscillator for harmonic suppression and a frequency doubler are designed and implemented. As the fundamental signal of the oscillator for frequency doubling is extracted between the dielectric resonator (DR) filter and the gate device of the active device, the undesired harmonics at the output of the oscillator is remarkably suppressed. The fundamental signal of the oscillator for frequency doubling directly feeds to the frequency doubler without an additional band pass filter for harmonic suppression. The second harmonic suppression of -47.7 dBc at the oscillator output is achieved, while the fundamental suppression of -37.5 dBc at the doubler output is obtained. The phase noise characteristics are -80.3 dBc/Hz and -93.5 dBc/Hz at the offset frequency of 10 KHz and 100 KHz from the carrier, respectively.

Ku-Band용 위상 고정 고조파 발진기 설계

이건준,김영식,Lee Kun-Joon,Kim Young-Sik 한국전자파학회 2005 한국전자파학회논문지 Vol.16 No.1

본 논문에서는 아날로그 위상 고정 루프(PLL: Phase Locked Loop)를 이용한 무선 LAN(Wireless Local Area Network)용 위상 고정 고조파 발진기(PLHO: Phase Locked Harmonic Oscillator)를 설계 및 제작하였다. 이 고조파 발진기는 Ring 공진기, 주파수 동조를 위한 바랙터 다이오드 그리고 위상 고정 루프 회로로 구성된다. 발진기의 8.5 GHz의 기본 주파수는 위상 고정 루프를 위한 귀환 신호로 이용되고 17.0 GHz의 2차 고조파는 출력으로 이용되므로 위상 고정 시스템에서 위상 비교를 위한 주파수 분배기를 한 단계 줄일 수 있다. 위상 비교기로는 샘플링 위상 검출기(SPD: Sampling Phase Detector)를 사용하여 위상고정 루프 회로를 간단히 하였다. 위상고정 고조파 발진기의 발진 출력은 17.0 GHz에서 2.17 dBm, 기본 주파수와 3차 고조파 억압 특성은 각각 -31.5 dBc, -29.0 dBc이다. 위상잡음은 각각 -87.6 dBc/Hz at 1 kHz와 -95.4 dBc/Hz at 10 kHz이다. In this paper, the phase locked harmonic oscillator(PLHO) using the analog PLL(Phase Locked Loop) is designed and implemented for a wireless LAN system. The harmonic oscillator is consisted of a ring resonator, a varactor diode and a PLL circuit. Because the fundamental fiequency of 8.5 GHz is used as the feedback signal for the PLL and the 2nd harmonic of 17.0 GHz is used as the output, a analog frequency divider for the phase comparison in the PLL system can be omitted. For the simple PLL circuit, the SPD(Sampling Phase Detector) as a phase comparator is used. The output power of the phase locked harmonic oscillator is 2.23 dBm at 17 GHz. The fundamental and 3rd harmonic suppressions are -31.5 dBc and -29.0 dBc, respectively. The measured phase noise characteristics are -87.6 dBc/Hz and -95.4 dBc/Hz at the of offset frequency of 1 kHz and 10 kHz from the carrier, respectively.

PIN 다이오드를 이용한 편파 변환 마이크로스트립 원형 패치 안테나

이건준,장태언,김영식,Lee Kun-Joon,Jang Tai-Un,Kim Young-Sik 한국전자파학회 2006 한국전자파학회논문지 Vol.17 No.1

In this paper, a circular microstrip patch antenna for switchable polarization is presented. For the switchable polarization, pairs of tuning stubs and two PIN diodes are utilized. By independently setting the PIN diodes on or off, the antenna produces either linear polarization or circular polarization. From the results, the -10 dB impedance bandwidths of 57.0 MHz($2.4\%$) and 50.0 MHz($2.1\%$) when operated in the linear polarization, and the 3 dB axial ratio bandwidth of $1.3\%$ with minimum of 0.2 and 0.9 dB in the circular polarization have been observed. 본 논문에서는 PIN 다이오드를 이용하여 다양한 편파 변환 특성을 갖는 마이크로스트립 원형 패치 안테나를 제안하였다. 안테나의 방사 패치에 두 개의 튜닝 스터브를 일정 거리를 두어 배치하고 PIN 다이오드로 각각의 튜닝 스터브를 방사 패치에 대하여 전기적으로 단락과 개방으로 스위칭함으로써 편파 변환 특성을 갖도록 하였다. 각각의 PIN 다이오드의 on/off 특성에 따라 안테나의 방사 특성은 두 주파수대의 선형 편파와 원형 편파, 우화전 원형 편파와 좌회전 원형 편파의 특성을 나타내게 된다. PIN 다이오드가 모두 on 또는 모두 off일 때 선형 편파가 발생하게 되고, 둘 중에 하나만 on되면 원형 편파 특성을 나타내게 된다. 안테나 측정 결과, 선형 편파일 경우에는 -10 dB 임피던스 대역폭은 각각 57.0 MHz($2.4\%$)와 50.0 MHz($2.1\%$)이며 방사 패턴에 있어서는 -15 dB 이하의 교차 편차 특성을 나타내었다. 또한, 원편파로 동작하는 경우, 좌${\cdot}$우 회전 편파에 대하여 모두 약 $1.3\%$의 축비 대역폭을 가졌으며 축비의 최소값은 0.2와 0.9 dB로 측정되었다.

Optical and Biological Properties of Plasma-Treated Neurospora crassa Spores as Studied by Absorption, Circular Dichroism, and Raman Spectroscopy

이건준,박경순,최은하 한국물리학회 2017 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.71 No.10

We studied the effect of plasma treatment on the optical, structural and biological properties of Neurospora crassa (N. crassa) spores. An atmospheric-pressure plasma jet (APPJ) was used to generate reactive oxygen and nitrogen species in aqueous solution. The APPJ treatment of N. crassa spores in water significantly reduced the viability of spores. The reduction in the spore viability can be attributed to the reactive species from the plasma itself and those derived from the reaction of plasma radicals with aqueous solution. These structural modifications were contingent on the medium in which N. crassa spores were suspended; plasma treatment of N. crassa spores in PBS did not significantly affect the viability of spores as compared with N. crassa spores in water. Scanning electron microscopy images and circular dichroism spectra indicated that the spore cell wall was damaged by plasma treatment. The optical absorption spectrum of untreated N. crassa spores exhibited two resonance absorption bands at approximately 1 ' 260 nm and 2 ' 472 nm, originating from deoxyribonucleic acid (DNA) and -carotene. The Raman spectrum of untreated N. crassa spores exhibited three main peaks at 1519, 1157 and 1006 cm−1, attributed to -carotene inside the cell wall. The Raman spectra showed that the APPJ treatment of N. crassa spores in water caused degradation of -carotene, affecting the viability of spores.

Photoluminescence and Lasing Properties of ZnO Nanorods

이건준,이영백,임환홍,차명식,Sung Soo Kim,정현식,민선기,한성환 한국물리학회 2010 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.57 No.61

In this study, we investigated the structures, photoluminescence (PL), and lasing characteristics of the ZnO nanorods prepared by using chemical bath deposition. The continuous-wave HeCd laserexcited PL spectra of the ZnO nanorods exhibited two emission bands, one in the UV region and the other in the visible region. The UV emission band has its peak at 3.25 eV with a bandwidth of 160 meV. However, the PL spectra under 355-nm, 35-ps pulse excitation exhibited a spectrally-narrowed UV emission band with a peak at 3.20 eV and a spectral width of 35 meV. The lasing phenomena were ascribed to the amplified spontaneous emission (ASE) caused by coupling of the microcavity effect of ZnO nanorods and the high-intensity excitation. Above the lasing threshold, the ASE peak intensity exhibited a superlinear dependence on the excitation intensity. For an excitation pulse energy of 3 mJ, the ASE peak intensity was increased by enlarging the length of the ZnO nanorods from 1 µm to 4 µm. In addition, the PL spectrum under 800-nm femtosecond pulse excitation exhibited second harmonic generation, as well as the multiphoton absorption-induced UV emission band. In this research, ZnO nanorods were grown on seed layers by using chemical bath deposition in an aqueous solution of Zn(NO3)2 and hexamethyltetramine. The seed layers were prepared on conducting glass substrates by dip coating in an aqueous colloidal dispersion containing 50% 70-nm ZnO nanoparticles. Scanning electron microscopy clearly revealed that ZnO nanorods were successfully grown on the seed layers.