• Title/Summary/Keyword: LCO

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LED-based illuminated V-core optical engine

  • Chen, Chin-Chung;Mo, Chi-Neng;Wu, Shih-Min
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.560-563
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    • 2006
  • LED is promising for the application of specialty illumination. Thiscolor management system, V-core, with LED light sources and the structure of V-core for LCoS projector has been proposed to improve the primary saturation, uniformity and contrast. We designed the high efficient LED modules for high brightness requirement. The LED module can operate in narrow-direction indicator, $12^{\circ}$.

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Effect of Extraction Solvent on the Separation of Sulfur Components in Light Cycle Oil (접촉분해경유로부터 산화황화합물의 분리에 관한 추출용매의 영향)

  • Park, Su-Jin;Jeong, Kwang-Eun;Chae, Ho-Jeong;Kim, Chul-Ung;Jeong, Soon-Yong;Koo, Kee-Kahb
    • Korean Chemical Engineering Research
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    • v.46 no.5
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    • pp.965-970
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    • 2008
  • The separation of sulfone components using light cycle oil(LCO) after oxidation was carried out by solvent extraction method using various polar solvents such as water, n-methyl-2-pyrrolidone(NMP), dimethyl sulfoxide, ethyl acetate, acetonitrile, dimethyl formamide, and methyl alcohol. It was found that phase separation between LCO layer and solvent occurred under mixed solvent adding a proper amount of water. The mixture solvent of NMP and water was a promising extraction solvent due to the selective removal and high distribution coefficient of sulfone component in LCO. 99.5% over of sulfur contents in LCO can be removed by 4 stages equilibrium extraction.

Experimental Study of Breakdown Pressure, Acoustic Emission, and Crack Morphology in Liquid CO2 Fracturing (액체 이산화탄소 파쇄법의 파쇄 압력, 음향 방출, 균열 형상에 관한 실험적 연구)

  • Ha, Seong Jun;Yun, Tae Sup
    • Tunnel and Underground Space
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    • v.29 no.3
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    • pp.157-171
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    • 2019
  • The fracturing by liquid carbon dioxide ($LCO_2$) as a fracking fluid has been an alternative to mitigate the environmental issues often caused by the conventional hydraulic fracking since it facilitates the fluid permeation owing to its low viscosity. This study presents how $LCO_2$ injection influences the breakdown pressure, acoustic emission, and fracture morphology. Three fracturing fluids such as $LCO_2$, water, and oil are injected with different pressurization rate to the synthetic and porous mortar specimens. Also, the shale which has been a major target formation in conventional fracking practices is also tested to examine the failure characteristics. The results show that $LCO_2$ injection induces more tortuous and undulated fractures, and particularly the larger fractures are developed in cases of shale specimen. On the other hand, the relationship between the fracturing fluids and the breakdown pressure shows opposite tendency in the tests of mortar and shale specimens.

Photoalignment of Liquid Crystal on Silicon Microdisplay

  • Zhang, Baolong;Li, K. K.;Huang, H. C.;Chigrinov, V.;Kwok, H. S.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.295-298
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    • 2003
  • Reflective mode liquid crystal on silicon (LCoS) microdisplay is the major technology that can produce extremely high-resolution displays. A very large number of pixels can be packed onto the CMOS circuit with integrated drivers that can be projected to any size screen. Large size direct-view thin film transistor (TFT) LCDs becomes very difficult to make and to drive as the information content increases. However, the existing LC alignment technology for the LCoS cell fabrication is still the mechanical rubbing method, which is prone to have minor defects that are not visible normally but can be detrimental if projected to a large screen. In this paper, application of photo-alignment to LCoS fabrication is presented. The alignment is done by three-step exposure process. A MTN $90^{\circ}$ mode is chose as to evaluate the performance of this technique. The comparison with rubbing mode shows the performance of photo-alignment is comparable and even better in some aspect, such as sharper RVC curve and higher contrast ratio.

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Examination on Combustion Quality Analysis of Residue Heavy Fuel Oil and Improvement of Combustion Quality Using Pre-injection (중질 잔사유의 연소성 분석과 보조 분사에 의한 연소성 향상에 관한 검토)

  • Yoo, Dong-Hoon
    • Journal of Power System Engineering
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    • v.18 no.6
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    • pp.113-119
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    • 2014
  • Due to the development of the petroleum refining technology and continuously increased demand from markets, a quantity of gasoline and diesel oil produced from a restricted quantity of crude oil has been increasing, and residual fuel to be used at marine diesel engines has been gradually becoming low quality. As a result, it was recently reported that trouble oils which cause abnormal combustion such as knocking with extreme noise and misfire from internal combustion engines were increasing throughout the world. In this study, an author investigated ignitability and combustion quality by using combustion analyzer with constant volume(FCA, Fuel Combustion Analyzer) and middle speed diesel engine about MDO(Marine Diesel Oil), HFO(Heavy Fuel Oil), LCO(Light Cycle Oil) and Blend-HFO which was blended LCO of 1000 liters with HFO of 600 liters. Moreover, for betterment of ignitability and combustion quality of injected fuels, multi-injection experiment was carried out in the diesel engine using Blend-HFO. According to the results of FCA analysis, ignitability and combustion quality was bad in the order of MDO

Effect of Lithium Ion Concentration on Electrochemical Properties of BF3LiMA-based Self-doping Gel Polymer Electrolytes (BF3LiMA기반 자기-도핑형 겔 고분자 전해질의 전기화학적 특성에 미치는 리튬이온 농도의 영향)

  • Kang, Wan-Chul;Ryu, Sang-Woog
    • Journal of the Korean Electrochemical Society
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    • v.13 no.3
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    • pp.211-216
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    • 2010
  • Boron trifluoride lithium methacrylate ($BF_3$LiMA)-based gel polymer electrolytes (GPEs) were synthesized with various $BF_3$LiMA concentration to elucidate the effect on ionic conductivity and electrochemical stability by a AC impedance and linear sweep voltammetry (LSV). As a result, the highest ionic conductivity reached $5.3{\times}10^{-4}Scm^{-1}$ at $25^{\circ}C$ was obtained for 4 wt% of $BF_3$LiMA. Furthermore, high electrochemical stability up to 4.3 V of the $BF_3$LiMA-based GPE was observed in LSV measurement since the counter anion was immobilized in this self-doped system. On the other hand, it was assumed that there was a rapid decomposition of electrolytes on a lithium metal electrode which results in a high solid electrolyte interface (SEI) resistance. However, a high stability toward graphite or lithium cobalt oxide (LCO) electrode thereby a low SEI resistance was observed from the AC impedance measurement as a function of storage time at $25^{\circ}C$. Consequently, the high ionic conductivity, good electrochemical stability and the good interfacial compatibility with graphite and LCO were achieved in $BF_3$LiMA-based GPE.

Effect of the Head Support on a Change in Muscle Thickness for Longus Colli and Sternocleidomastoid During Cranio-Cervical Flexion Test in Subjects With Forward Head Posture (앞쪽머리자세를 가진 대상자의 머리-목 굽힘 검사 시 머리받침 유무에 따른 긴목근과 목빗근의 근두께 변화량 비교)

  • Park, Jun-sang;Song, Si-jeong;Jung, Hee-seok;Kwon, Oh-yun
    • Physical Therapy Korea
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    • v.23 no.3
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    • pp.11-20
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    • 2016
  • Background: A forward head posture (FHP) is one of the most common types of poor head posture in patients with neck disorder. A prolonged FHP might increase pressure on the posterior cranio-cervical structure and exhibit reduced performance on a cranio-cervical flexion test (CCFT). CCFT is included to activate deep cervical flexor muscles and inhibit excessive activation of superficial cervical flexor muscles. Therefore, the selective activation of deep cervical flexors is needed for effective exercise for FHP. Objects: The purpose of this study was to compare muscle thickness between longus colli (Lco) and sternocleidomastoid (SCM) using ultrasonography in subjects with FHP depending on head support. Methods: This was a cross-sectional, case-control research design study. The ultrasonographic images of Lco and SCM were taken in 17 subjects with FHP during the 5 phases of the CCFT with and without a head support. Towel was used for supporting head to make the neutral head position in supine. Changes in muscle thickness during the test were calculated to infer muscle activation. Data were analyzed using repeated measures of two-way analysis of variance with the significance level of .05. Results: When subjects performed the CCFT with head support, there was a significant difference in muscle thickness of Lco and SCM (p<.05). According to a post hoc paired t-test, change of thickness of Lco was greater at all phases, and change of thickness of SCM muscle was less at phase 4 and 5 in condition with head support (p<.01) compared to condition without head support (p<.01). Conclusion: The result of this study suggest that applying head support for neutral head position during CCFT could be a useful method for activating Lco muscle without excessive activation of SCM muscle.

Separation of 2,6-dimethylnaphthalene in Dimethylnaphthalene Isomers Mixture by Crystallization Operation (결정화 조작에 의한 Dimethylnaphthalene 이성체 혼합물 중의 2,6-dimethylnaphthalene의 분리)

  • Kang, Ho-Cheol;Kim, Su Jin
    • Applied Chemistry for Engineering
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    • v.25 no.1
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    • pp.116-120
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    • 2014
  • Light cycle oil (LCO), one of the by-products of the catalytic cracking gasoline manufacturing process, contains a lot of valuable aromatics. In particular, 2,6-dimethylnaphthalene (2,6-DMN) contained in LCO has been becoming important as the basic material of polyethylene naphthalate plastic and liquid crystal polymer, etc. If it were possible to separate and purify the valuable aromatic hydrocarbons (such as 2,6-DMN) from LCO, which have only been used as fuel mixed with heavy oil, it would be very meaningful in terms of the efficient use of resources. We investigated the high-purity purification of 2,6-DMN by the combined method of melt crystallization (MC) and solute crystallization (SC). The enriched DMN isomer mixtures (concentration of 2,6-DMN : 10.43%) recovered from LCO by distillation-extraction combination and the crystal recovered by MC used as raw materials of MC and SC, respectively. The solvent of SC used was a mixture of methanol and acetone (60 : 40 wt%). The crystal of 2,6-DMN with a high-purity of 99.5% was recovered by MC-SC combination. We confirmed that the MC-SC combination was one of the very useful combinations for the high-purity purification of 2,6-DMN contained in the enriched DMN isomer mixtures.