• 한국전자파학회논문지
• /
• 제28권1호
• /
• pp.69-75
• /
• 2017

본 논문에서는 자기공진형 무선전력전송의 실용화에 있어, 공진기 간 자기결합을 방해하는 그라운드 문제를 해결하기 위해 슬릿 구조를 설계하고, 커패시터를 연결하여 공진기로써의 성능을 기본적인 루프형의 수신 공진기와 비교하였다. 제안된 슬릿 그라운드 공진기(slit ground resonator)는 가로 31 cm, 세로 20.5 cm, 두께 $35{\mu}m$의 구리박판에 넓이 1 cm의 슬릿을 한 방향이 열린 십자 형태로 설계하였으며, 열린 방향 양단에 6.78 MHz에서 공진하도록 최적의 커패시터가 연결되어 공진기 역할이 가능하다. 수신 공진기는 스위치를 연결하여 열림형(open mode)과 닫힘형(short mode)일 때를 측정하고, 최고 전송효율을 표시하였다. 측정 결과, 수신 공진기가 루프 공진기일 때 가장 높은 전송효율을 보였다. 그러나 노트북 모델의 수신부에 그라운드를 삽입했을 때, 전송효율이 0 %에 가깝게 감소하였다. 반면, 슬릿 그라운드 공진기를 수신 공진기로 사용했을 때, 전송효율은 가장 높았던 루프 공진기의 67 % 회복하였다. 제안된 슬릿 그라운드 공진기는 슬릿을 통해 자기장을 통과시키며, 커패시터를 연결이 공진기로 동작하게 하여 주변 공진기 간 자기결합을 통해 전력을 전송해주는 역할을 수행한다.

• Journal of Korean Neurosurgical Society
• /
• 제53권5호
• /
• pp.288-292
• /
• 2013

Objective : Vertebral distraction is routinely performed during anterior cervical discectomy and fusion (ACDF). Overdistraction can injure the facet joints and may cause postoperative neck pain consequently. The purpose of this study was to investigate the clinical relevance of distraction force during ACDF. Methods : This study included 24 consecutive patients with single level cervical disc disease undergoing single level ACDF. We measure the maximum torque just before the the arm of the Caspar retractor was suspended by the rachet mechanism by turning the lever on the movable arm using a torque meter. In order to turn the lever using the torque driver, we made a linear groove on the top of the lever. We compared the neck disability index (NDI) and visual analogue scale (VAS) scores between the high torque group (distraction force>6 $kgf{\cdot}cm$) and the low torque group (distraction force${\leq}6kgf{\cdot}cm$) at routine postoperative intervals of 1, 3, 5 days and 1, 3, 6 months. Results : The VAS scores for posterior neck pain had a linear correlation with torque at postoperative 1st and 3rd days ($y=0.99{\times}-1.1$, $r^2=0.82$; $y=0.77{\times}-0.63$, $r^2=0.73$, respectively). VAS scores for posterior neck pain were lower in the low torque group than in the high torque group on both 1 and 3 days postoperatively ($3.1{\pm}1.3$, $2.6{\pm}1.0$ compared with $6.0{\pm}0.6$, $4.9{\pm}0.8$, p<0.01). However, the difference in NDI scores was not statistically significant in all postoperative periods. Conclusion : Vertebral distraction may cause posterior neck pain in the immediate postoperative days. We recommend not to distract the intervertebral disc space excessively with a force of more than 6.0 $kgf{\cdot}cm$.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2007년도 추계학술대회 논문집
• /
• pp.274-274
• /
• 2007

LTCC 소재로 응용을 위해 Mg-Si-O계 세라믹스에 glass frit을 첨가하여 소결 및 마이크로파 유전특성에 관한 연구를 진행하였다. $Mg_2SiO_4$를 기본조성으로 하고 $B_2O_3-ZnO-Na_2O-SiO_2-Al_2O_3$계 glass를 20~40wt%로 첨가하여 $900^{\circ}C$에서 1시간 소결하였을 때 glass 함량이 증가함에 따라 밀도$(g/cm^3)$ 및 유전율$(\varepsilon_r)$은 증가하였고 품질계수$(Q{\times}f_0)$ 값은 감소하는 경향을 보였다. $900^{\circ}C$에서 1시간 소결한 소결체의 유전특성은 유전율 $(\varepsilon_r)$ = 6.5, 품질계수 $(Q{\times}f_0)$ = 4,000(GHz), 온도계수 $({\tau}_f)={\pm}10ppm/^{\circ}C$로 우수한 특성을 확인하였다. 그리고 Glass Milling 효과에 따른 glass-ceramics 소결체의 미세구조, 마이크로파 유전특성을 비교 고찰하였다.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
• /
• pp.49-49
• /
• 2007

Glass infiltration 방법을 이용하여 '$A_2O_3$/Glass/$Al_2O_3$' 구조의 무수축 LTCC 기판을 제조하였다. Glass infiltration 법에 의한 무수축 기판 제조에 있어 가장 중요한 요소로는 Glass의 점성은 낮고, alumina에 대한 Glass의 젖음성 (wettability)이 좋으며. 낮은 반응성이 요구되기 때문에 Glass의 조성 선정이 무엇보다 중요하다. 본 연구에서는 Na, Pb, Mg 계열의 각기 다른 glass들의 alumina에 대한 젖음성을 평가하여 젖음성 및 치밀성이 우수한 Pb 계열의 Glass를 이용하여 LTCC 기판으로 적용 가능한 온도인 $700{\sim}900^{\circ}C$에서 '$A_2O_3$/Glass/$Al_2O_3$'구조의 glass infiltration 특성을 고찰하였다. 소성 후 수축율은 x-y축 0.2%, Z축 40%, 밑도 $3.8g/cm^3$, 유전율 6.8, 품질계수 552로 무수축 기판으로서의 적용 가능성을 확인하였다.

• Nuclear Engineering and Technology
• /
• 제54권3호
• /
• pp.959-964
• /
• 2022

Lead is an important material, both for fusion or fission reactors. The cross sections of natural lead should be validated because lead is a main component of lithium-lead modules suggested for fusion power plants and it directly affects the crucial variable, tritium breeding ratio. The presented study discusses a validation of the lead transport libraries by dint of the activation of carefully selected activation samples. The high emission standard ²⁵²Cf neutron source was used as a neutron source for the presented validation experiment. In the irradiation setup, the samples were placed behind 5 and 10 cm of the lead material. Samples were measured using a gamma spectrometry to infer the reaction rate and compared with MCNP6 calculations using ENDF/B-VIII.0 lead cross sections. The experiment used validated IRDFF-II dosimetric reactions to validate lead cross sections, namely ¹⁹⁷Au(n, 2n)¹⁹⁶Au, ⁵⁸Ni(n,p)⁵⁸Co, ⁹³Nb(n, 2n)^92mNb, ¹¹⁵In(n,n')^115mIn, ¹¹⁵In(n,γ)^116mIn, ¹⁹⁷Au(n,γ)¹⁹⁸Au and ⁶³Cu(n,γ)⁶⁴Cu reactions. The threshold reactions agree reasonably with calculations; however, the experimental data suggests a higher thermal neutron flux behind lead bricks. The paper also suggests ²⁵²Cf isotropic source as a valuable tool for validation of some cross-sections important for fusion applications, i.e. reactions on structural materials, e.g. Cu, Pb, etc.

• Journal of Korean Neurosurgical Society
• /
• 제66권6호
• /
• pp.703-715
• /
• 2023

Objective : This retrospective study investigated the factors that affect cage obliquity angle despite orthogonal maneuvers performed during oblique lateral interbody fusion (OLIF) and assessed the relationship between cage obliquity angle and radiological outcomes post-surgery. Methods : Twenty-nine males who underwent L4-L5 OLIF for lumbar degenerative disease between 2019 and 2021 with a followup duration greater than 12 months were analyzed. Radiological parameters were measured including psoas muscle volume, total psoas area index (total psoas muscle area [cm²]/height squared [m²]), distance from the iliac artery to the origin of the psoas muscle (DIAPM), angle between the origin of the psoas muscle and the center of the vertebral disc (APCVD), iliac crest height, disc height, lumbar flexibility (lumbar flexion angle minus extension angle), cage location ratio, cage-induced segmental lumbar lordosis (LL) (postoperative index level segmental LL minus used cage angle), foraminal height changes, fusion grade. Results : DIAPM, APCVD, iliac crest height, postoperative index level segmental LL, and cage-induced segmental LL were significantly correlated with OLIF cage obliquity angle. However, other radiological parameters did not correlate with cage obliquity. Based on multiple regression analysis, the predictive equation for the OLIF cage obliquity angle was 13.062-0.318×DIAPM+0.325×1APCVD+0.174×iliac crest height. The greater the cage obliquity, the smaller the segmental LL compared to the cage angle used. Conclusion : At the L4-L5 level, OLIF cage obliquity was affected by DIAPM, APCVD, and iliac crest height, and as the cage obliquity angle increases, LL agnle achievable by the used cage could not be obtained.

• 한국식품과학회지
• /
• 제44권5호
• /
• pp.634-637
• /
• 2012

딸기병해는 생육기 동안 과실의 생산량감소 및 품질저하를 가져오고 있으며, 약제방제의 어려움 등으로 인해 친환경적인 병해 방제법의 개발이 요구된다. 실내에서 자외선(UV-C, 264 nm)조사에 의한 딸기병원균의 균사생장 억제효과를 구명하기 위하여 5종의 딸기병원균을 자외선을 조사하면서 $25^{\circ}C$ 항온실에서 배양한 후 균총의 직경을 측정하였다. 5종의 딸기병원균을 PDA 상에서 배양하면서 자외선을 조사하면, 하루 1시간 조사에 의해서도 생장이 억제되었고 9-12시간을 조사한 균의 생육은 현저하게 억제되었으며 역병균은 생육이 완전하게 억제되었다. 자외선광원과 병원균의 거리에서는 40-50 cm의 거리에서 자외선을 조사한 배양기에서 병원균생장의 억제효과가 크게 나타났다. 배지에 접종한 후 바로 자외선을 처리한 병원균은 모두 2일간 배양한 후 자외선을 접종한 배양기에서보다 생육이 억제되었다. 딸기 탄저병균(C. gloeosprioides)과 시들음병균(F. oxysporum)은 V8A에서 자외선에 의한 균의 생장억제효과가 큰 것으로 나타났다.

• 한국수정란이식학회지
• /
• 제15권3호
• /
• pp.247-253
• /
• 2000

This study was undertaken to optimize enucleation and reconstitution methods for the production of cloned mice by somatic cell nuclear transfer Outbred ICR mouse oocytes at the metapahse- II stage were retrieved from female mice superovulated by PMSG and hCG. In Experiment 1, oocytes were enucleated in medium supplemented with cytochalasin B (CCB) of 3 levels (0, 7.5 or 15 $\mu\textrm{g}$/mL), and higher rate of encleation was obtained at 7.5 and 15 $\mu\textrm{g}$/mL than at $\mu\textrm{g}$/mL. In Experiment 2, oocytes enucleated in 7.5 $\mu\textrm{g}$/mL CCB-containing medium were reconstituted with different types of somatic cell by following methods; 1) cumulus cells by direct cell injection, 2) cumulus cells by electric fusion (1.25 kV/cm, 2 pulses for each 70 $mutextrm{s}$) or 3) STO cells by the electrofusion. Electrofusion of STO cells with enucleated oocytes yielded the greatest (P<0.05) rate of reconstitution without lysis (76%) than any other combinations. Although significant decrease in the rate of somatic cell introduction was found, the electrofusion of cumulus cells yielded better rate of reconstitution than direct injection (0 vs. 18%). In Experiment 3, the duration of electric stimulation for the fusion was changed to either 50 $mutextrm{s}$ or 90 $mutextrm{s}$, but no significant improvement of reconstitution efficacy was obtained. In conclusion, this study showed that ICR mouse oocytes could be used for the production of reconstituted oocytes and a fusion method of 1.25 KV/cm with 2 pulses using 570 cell was the optimal.

• 한국미생물·생명공학회지
• /
• 제16권4호
• /
• pp.275-281
• /
• 1988

호알칼리성 Bacillus sp. F204와 Bacillus sp. K 17간에 원형질체 융합에 의한 cellulase와 xylanase를 동시에 생산하는 균주를 개발하기 위하여 두 균주에 500 $\mu\textrm{g}$/ml NTG를 처리한 후 약제내성변이주 인 S20(Km$^r$, Cm$^r$과 G70(Str$^r$)을 분리하였다. 원형질체 형성율은 균체를 대수증식기 중기까지 배양하여 200$\mu\textrm{g}$/m1 Iysozyme으로 37$^{\circ}C$에서 30-45분간 처리하였을 때 약 95%였다. 재생배지에 0.4-0.5M sodium succinate, 0.5% casamino acid, 1.5% polvinylpyrrolidone, 25mM MgC1$_2$및 50mM CaC1$_2$를 첨가하므로 Bacillus sp. F204와 Bacillus sp. K17의 재생율은 각각 24.9%, 26.2%였다. 50mM $Ca^{++}$을 첨가한 30%의 PEG 6,000용액을 45$^{\circ}C$에서 5분간 융합시킴으로써 6.2$\times$$10^{-6}$ 빈도로 융합주를 얻었다. cellulase, xylanase 및 avicelase를 생산하는 융합주는 모균주와 비교하였다.

• 한국의류학회지
• /
• 제38권5호
• /
• pp.675-689
• /
• 2014

This study developed an ideal jeggings pattern with an improved body fit for 20-24 year old females. The results of the study are as follows. First, samples for wearing test were made using jegging patterns from three manufacturers; subsequently, one pattern with a relatively outstanding body fit was selected from the first test. The selected pattern suggested a tight knee, belly, and crotch, high front waist line, and low back waist line. The side lines were also lean to the front; consequently, the front hip width was extended for 0.5cm for more space around the belly and the extended front knee part for 0.2cm to increase moving suitability to fix the leaning side lines. A 1cm front waist line was extended for 0.5cm to fix it lower; in addition, the back waist line 3.0cm was extended for 0.5cm to heighten it. The crotch width was also extended for 0.5cm to add more space. The second wearing test for the fixed forms were evaluated for their outstanding features in appearance as well as moving functions that were proposed as final jeggings forms. The results of the study suggested a jeggings pattern with a better body fit using manufacturer patterns that can be used as basic data for pant patterns with better fitting using various stretch fabrics.