• Title/Summary/Keyword: External injection

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Time dependent polarization switching properties of injection-locked 1.55-${\mu}m$ VCSEL

  • Deshmukh, Vijay Manohar;Lee, Seoung-Hun;Lee, Min-Hee;Kim, Dong-Wook;Kim, Kyong-Hon
    • Proceedings of the Optical Society of Korea Conference
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    • 2009.10a
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    • pp.359-360
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    • 2009
  • This paper reports experimental results on temporal characteristics of injection-locked polarization switching of a conventional type 1.55-${\mu}m$ wavelength single-mode vertical-cavity surface-emitting laser (VCSEL). The polarization of external injection beam was kept orthogonal to main mode of VCSEL. The relation for variation of intensity of two polarization modes of VCSEL with wavelength detuning for various repetition rates of injection pulse is reported.

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Efficient Organic Light-Emitting Diodes with a use of Hole-injection Buffer Layer

  • Kim, Sang-Keol;Chung, Dong-Hoe;Chung, Taek-Gyun;Kim, Tae-Wan
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.766-769
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    • 2002
  • We have seen the effects of hole-injection buffer layer in organic light-emitting diodes using copper phthalocyanine(CuPc), poly(vinylcarbazole)(PVK), and Poly(3,4-ethylenedioxythiophene):poly(styrene-sulfonate)(PEDOT:PSS) in a device structure of ITO/buffer/TPD/$Alq_3$/Al. Polymer PVK and PEDOT:PSS buffer layer was made using spin casting method and the CuPc layer was made using thermal evaporation. Current-voltage characteristics, luminance-voltage characteristics and efficiency of device were measured at room temperature with a thickness variation of buffer layer. We have obtained an improvement of the external quantum efficiency by a factor of two, four, and two and half when the CuPc, PVK, and PEDOT:PSS buffer layer are used, respectively. The enhancement of the efficiency is attributed to the improved balance of holes and elelctrons due to the use of hole-injection buffer layer. The CuPc and PEDOT:PSS layer functions as a hole-injection supporter and the PVK layer as a hole-blocking one.

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A Design of Sliding Mode Observer for SISO Linear Systems (단일 입.출력 선형시스템에 대한 슬라이딩 모드 관측기 설계)

  • 문형장;권성하;박승규;정은태
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.24-24
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    • 2000
  • This paper proposes a design method of sliding mode observer for SISO linear systems with a disturbance input. We first construct an observer with a constant gain matrix, a feedforward injection map and an external feedforward compensation signal input. Using the second Lyapunov method, we present a sufficient condition for the existence of sliding mode observer. The proposed observer guarantees that the state error trajectories enter a certain region in finite time and remain inside thereafter.

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Hall Effect on Unsteady Hartmann Flow with Heat Transfer Under Exponential Decaying Pressure Gradient

  • Attia Hazem A.
    • Journal of Mechanical Science and Technology
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    • v.20 no.8
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    • pp.1302-1308
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    • 2006
  • The unsteady Hartmann flow of an electrically conducting, viscous, incompressible fluid bounded by two parallel non-conducting porous plates is studied with heat transfer taking the Hall effect into consideration. An external uniform magnetic field and a uniform suction and injection are applied perpendicular to the plates while the fluid motion is subjected to an exponential decaying pressure gradient. The two plates are kept at different but constant temperatures while the Joule and viscous dissipations are included in the energy equation. The effect of the ion slip and the uniform suction and injection on both the velocity and temperature distributions is examined.

Accuracy and Clinical Outcomes of Ultrasound-guided Glenohumeral joint Injection: Acromioclavicular Approach in Patients with Adhesive Capsulitis (초음파를 이용한 견관절 관절강내 주사의 정확성과 임상적 결과: 유착성 관절낭염 환자의 견봉 쇄골 접근법)

  • Lhee, Sang-Hoon;Hwang, Seok-Min
    • The Journal of Korean Orthopaedic Ultrasound Society
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    • v.5 no.1
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    • pp.9-14
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    • 2012
  • Purpose: The purpose of the study was to evaluate the accuracy and clinical outcome of ultrasound-guided glenohumeral joint steroid injection on adhesive capsulitis. Materials and Methods: Patients who were diagnosed as adhesive capsulitis by MRI and physical examination and did not improve their symptom with physical therapy and NSAIDS treatment more than 6 months were included in the study. Patients who showed any other shoulder pathology or history if trauma were excluded from the study. 33 patients including 15 males and 18 females were enrolled in the study, the average age being 55.1 (age 42~72). Cocktail of steroid, lidocaine, saline and contrast medium injected inside shoulder glenohumeral joint using novel approach (which we called acromioclavicular approach) under ultrasound guidance. Clinical outcome was measured through passive range of motion and VAS scoring system. Results: Based on radiographic findings, cases were classified according to the leakage of contrast medium; perfect confinement of contrast-medium inside the capsule, partial leakage of the medium and contrast-medium found at outside the joint. Total 25 cases (76%) out of 33 cases showed perfect confinement of contrast-medium inside the glenohumeral joint. Partial leakage was observed in 6 cases (18%), and contrast medium was observed outside of the glenohumeral joint in 2 cases (6%). Perfect-confinement group showed $111^{\circ}$($80{\sim}140^{\circ}$) of forward flexion and $48^{\circ}$($0{\sim}90^{\circ}$) of external rotation before injection, and improved to $134^{\circ}$($90{\sim}150^{\circ}$) of forward flexion and $70^{\circ}$($30{\sim}90^{\circ}$) of external rotation after injection (p<0.01). Partial leakage showed $120^{\circ}$($90{\sim}150^{\circ}$) of forward flexion and $70^{\circ}$($10{\sim}90^{\circ}$) of external rotation before injection, and improved to $139^{\circ}$($135{\sim}140^{\circ}$) of forward flexion and $78^{\circ}$($50{\sim}90^{\circ}$) of external rotation after injection (p<0.01). VAS score improved from 7.1 (score 3~9) to 2.6 (score 0~5) (p<0.01) in perfect confinement group, from 7.5 (score 7~9) to 3.3 (score 2~4) (p<0.01) in partial leakage group. Two group showed no significant difference. Conclusion: Accuracy of Acromioclavicular approach was 94% which is better than any other methods published so far. Partial leakage of the injection material did not show inferior result compared to perfect injection.

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Determination of Diesel Sprays Characteristics in Real Engine In-Cylinder air Density and Pressure Conditions

  • Payri Raul;Salvador F. J.;Gimeno J;Soare V.
    • Journal of Mechanical Science and Technology
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    • v.19 no.11
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    • pp.2040-2052
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    • 2005
  • The present paper centers on the establishment of a quantified relationship between the macroscopic visual parameters of a Diesel spray and its most influential factors. The factors considered are the ambient gas density, as an external condition relative to the injection system, and nozzle hole diameter and injection pressure as internal ones. The main purpose of this work is to validate and extend the different correlations available in the literature to the present state of the Diesel engine, i.e. high injection pressure, small nozzle holes, severe cavitating conditions, etc. Five mono-orifice, axi-symmetrical nozzles with different diameters have been studied in two different test rigs from which one can reproduce solely the real engine in-cylinder air density, and the other, both the density and the pressure. A parametric study was carried out and it enabled the spray tip penetration to be expressed as a function of nozzle hole diameter, injection pressure and environment gas density. The temporal synchronization of the penetration and injection rate data revealed a possible explanation for the discontinuity observed as well by other authors in the spray's penetration law. The experimental results obtained from both test rigs have shown good agreement with the theoretical analysis. There have been observed small but consistent differences between the two test rigs regarding the spray penetration and cone angle, and thus an analysis of the possible causes for these differences has also been included.

Management of Traumatic Cerebrospinal Fluid Rhinorrhea using External Ethmoidectomy Approach (비외사골동수술법을 이용한 외상성 뇌척수액 비루의 치료)

  • 임상철;조재식
    • Korean Journal of Bronchoesophagology
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    • v.3 no.1
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    • pp.169-173
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    • 1997
  • Cerebrospinal fluid (CSF) rhinorrhea usually occurs as a result of trauma including operation. Unheated CSF rhinorrhea may induce major morbidity such as meningitis and brain abscess, etc. This paper presents a review of four cases of traumatic CSF rhinorrhea Sites of CSF leakage were easily found out by intrathecal fluorescent dye injection. Surgery was performed by external ethmoidectomy approach and dural tear and bone defect was repaired with abdominal fat and free mucosal graft taken from amputated middle turbinates. We conclude that repair using free fat and mucosal graft via external ethmoidectomy approach could be accepted as the intial method of CSF rhinorrhea management.

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Performance of Blowoff Flow for a LPG Fuel Pump with Various Fuel Filters (LPG 펌프에서 필터 종류에 따른 펌프 토출성능에 대한 연구)

  • Lee, Seok-Hwan;Park, Cheol-Woong;Kim, Chang-Up
    • Journal of the Korean Institute of Gas
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    • v.13 no.4
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    • pp.1-7
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    • 2009
  • In recent years, the needs for more fuel-efficient and lower-emission vehicles have driven to use the alternative fuel of LPG(Liquefied Petroleum Gas) which is able to meet the more stringent legislations without many modifications to current engine. LPLi (Liquid Phase LPG Injection) system (the 3rd generation LPG injection system) is the core technology to produce power equivalent to a gasoline engine with less emissions. The LPG fuel pump can supply the compressed LP gas in the liquid phase to engine. The fuel filter is attached in the fuel pump to eliminate the remnants in the liquid phased LP gas and the performance of blowoff flow for a pump can be varied with various filters. In this study, experiments were conducted to investigate the performance and efficiency of the impeller type LPG fuel pump under various filter types of microfiber, double mesh and external filter. And blowoff flow for a LPG fuel pump was measured according to the temperature of the fuel.

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Novel anatomical guidelines for botulinum neurotoxin injection in the mentalis muscle: a review

  • Kyu-Ho Yi;Ji-Hyun Lee;Hye-Won Hu;Hyun-Jun Park;Hyungkyu Bae;Kangwoo Lee;Hee-Jin Kim
    • Anatomy and Cell Biology
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    • v.56 no.3
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    • pp.293-298
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    • 2023
  • The mentalis muscle is a paired muscle originating from the alveolar bone of the mandible. This muscle is the main target muscle for botulinum neurotoxin (BoNT) injection therapy, which aims to treat cobblestone chin caused by mentalis hyperactivity. However, a lack of knowledge on the anatomy of the mentalis muscle and the properties of BoNT can lead to side effects, such as mouth closure insufficiency and smile asymmetry due to ptosis of the lower lip after BoNT injection procedures. Therefore, we have reviewed the anatomical properties associated with BoNT injection into the mentalis muscle. An up-to-date understanding of the localization of the BoNT injection point according to mandibular anatomy leads to better injection localization into the mentalis muscle. Optimal injection sites have been provided for the mentalis muscle and a proper injection technique has been described. We have suggested optimal injection sites based on the external anatomical landmarks of the mandible. The aim of these guidelines is to maximize the effects of BoNT therapy by minimizing the deleterious effects, which can be very useful in clinical settings.

Fundamental study on gene transfer utilizing magnetic force and jet injector

  • Hasegawa, T.;Nakagam, H.;Akiyama, Y.;Nishijima, S.
    • Progress in Superconductivity and Cryogenics
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    • v.19 no.1
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    • pp.9-12
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    • 2017
  • Recently, DNA vaccination is attracting attentions as a new therapeutic method for lifestyle diseases and autoimmune diseases. However, its clinical applications are limited because a safe and efficient gene transfer method has not been established yet. In this study, a new method of gene transfer was proposed which utilizes the jet injection and the magnetic transfection. The jet injection is a method to inject medical liquid by momentary high pressure without needle. The injected liquid diffuses in the bio tissue and the endocytosis is considered to be improved by the diffusion. The magnetic transfection is a method to deliver the conjugates of plasmid DNA and magnetic particles to the desired site by external magnetic field. It is expected that jet injection of the conjugates causes slight membrane disruptions and the traction of the conjugates by magnetic field induces the efficient gene transfer. In conclusion, the possibility of improvement of the gene expression by the combination of jet injection and magnetic transfection was confirmed.