• Carbon letters
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• 제1권3_4호
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• pp.148-153
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• 2001

The initial irreversible capacity, $Q_i$, is one of the parameters to express the material balancing of the cathode to anode. We introduced new terms, which are the initial intercalation Ah efficiency (IIE) and the initial irreversible specific capacity at the surface ($Q_{is}$), to express precisely the irreversibility of an electrode/electrolyte system. Two terms depended on kinds of active-materials and compositions of the electrode, but did not change with charging state. MPCF had the highest value of IIE and the lowest value of $Q_{is}$ in 1M $LiPE_6$/EC + DEC (1 : 1 volume ratio) electrolyte. IIE value of $LiCoO_2$ electrode was 97-98%, although the preparation condition of the material and the electrolyte were different. $Q_{is}$ value of $LiCoO_2$ was 0~1 mAh/g. MPCF-$LiCoO_2$ cell system had the lowest of the latent capacity. $Q_{is}$ value increased slightly by adding conductive material. IIE and $Q_{is}$ value varied with the electrolyte. By introducing PC to EC+DEC mixed solvent, IIE values were retained, but $Q_{is}$ increased. In case of addition of MP, IIE value increased and $Q_{is}$ value also increased a little.

• KIEE International Transactions on Electrophysics and Applications
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• 제3C권5호
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• pp.189-193
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• 2003

Initial irreversible capacity (IIC) can be defined by means of the initial intercalation Ah efficiency (IIE) and the initial irreversible specific capacity at the surface (IICs) with the linear-fit range of the intercalation so as to precisely express the irreversibility of an electrode-electrolyte system. Their relationship was IIC = Qc - Q$_{D}$ = (IIE$^{-1}$ - 1) Q$_{D}$ + IICs in the linear-fit range of IIE. Here, Qc and Qd signify charge and discharge capacity, respectively, based on a complete lithium ion battery cell. Charge indicates lithium insertion to carbon anode. Two terms of IIE and IICs depended on the types of active materials and compositions of the electrode and electrolyte but did not change with charging state. In an ideal electrode-electrolyte system, IIE and IICs would be 100%, 0 mAh/g for the electrode and mAh for the cell, respectively. These properties can be easily obtained by the Gradual Increasing of State of Charge (GISOC).OC).

• 대한설비공학회지:설비저널
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• 제16권3호
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• pp.305-314
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• 1987

Thermodynamic analysis of a mixed refrigerant refrigeration cycle has been performed by computing thermodynamic properties of various refrigerants. The analyses are carried cut to identify the sources and distribution of the energy degradation by irreversible processes. Heat exchange process with the surroundings produces the entropy and the irreversible loss can be reduced by the mixed refrigerant whose phase change temperature varies during the phase change processes in the evaporator and the condenser. The concept has been applied to find the minimum compression work and thus the minimum energy loss in the overall system, specifically in the case of the mixed refrigerant of R12 and R114. Parametric studies have been added to recognize the various factors affecting the system performance.

• Korean Chemical Engineering Research
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• 제60권2호
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• pp.217-222
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• 2022

고분자 전해질 연료전지(PEMFC) 고분자 막의 전기화학적 내구성을 가속적으로 평가하는 개회로 전위 유지(OCV holding) 과정에서 OCV 변화 거동을 해석하는 것은 매우 중요하다. 본 연구에서는 내구성이 각기 다른 세 종류의 MEA(membrane electrode assembly)의 실험데이터를 이용한 실험식을 만들어 비교 및 검토하였다. 막 내부에 라디칼 제거제가 없는 강화막 MEA의 내구 평가시간은 383 h, 막 내부에 라디칼 제거제가 있는 강화막 MEA의 내구 평가시간은 각각 1,000, 1,650 h이었다. 고분자 막의 열화는 활성화에 의해 회복이 가능한 가역적 열화와 회복이 되지 않은 비가역적 열화로 구분했다. 고분자 막의 비가역적 열화는 수소투과도 증가로 나타나는데 수소투과도 변화가 세 MEA 모두 비가역적 열화 상수 c와 유사한 형태를 보였다. 회복이 되지 않은 비가역적 열화가 시작되는 것은 수소투과도 증가로 나타나고, 수소투과도 증가로 인해 OCV가 회복되지 않아서 OCV 회복선의 기울기가 감소하고 이를 실험식의 상수 c 값의 증가로 확인할 수 있었다.

• Journal of Korean Dental Science
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• 제11권1호
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• pp.21-31
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• 2018

Occlusion may change spontaneously but dental treatment or trauma in the patients with temporomandibular disorders (TMDs) may also alter occlusion. This report presents three cases displaying occlusal changes. Review of literature emphasizes the significance of TMD treatment. Conservative treatment modalities such as counseling, medication, physical therapy and splint therapy may be selected as initial treatment options. Irreversible or invasive treatment, such as orthodontic, prosthodontic, and occlusal adjustment should not be attempted early. In case there is no response to conservative treatment, joint injection, muscle injection, arthrocentesis or arthroscopic surgery might be performed.

• Journal of Chest Surgery
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• 제36권1호
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• pp.39-42
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• 2003

기관지내 지방종은 폐에서 발생하는 양성종양중 매우 드문 것으로 알려져 있다. 대개 서서히 진행되는 기관지 폐색과 함께 증상을 나타나는데, 대부분의 경우 기관지 폐쇄가 일어난 다음에 진단되므로 비가역적 기관지 확장이나 폐실질의 비가역적 손상을 가져온다. 진단은 흠부 기관지경검사나 흉부컴퓨터 단층촬영, 자기공명영상 촬영등으로 할 수 있으나, 흉부컴퓨터 단층촬영이 특히 민감도와 특이도가 높은 것으로 알려져 있으며, 치료는 내시경하 종괴의 제거 또는 개흉술을 통한 종괴의 제거 또는 폐엽절제술을 시행하는 것으로 알려져 있다 본 저자들은 우중엽을 완전히 막고 있으면서, 폐색후 폐실질의 손상을 동반한 기관지내 지방종을 1례 경험하여 문헌고찰과 함께 보고하는 바이다.

• 설비공학논문집
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• 제3권4호
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• pp.241-249
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• 1991

A quasi-three dimensional calculation method is presented on the basis of Wu's idea using finite element methods. In B-B flow the governing equations are cast into a single equation to overcome the restriction of the type of turbomachinery, and Kutta condition is exactly assured by introducing a combination of two kinds of stream functions. In H-S flow a dissipative force which is assumed to be opposed to the relative velocity is added to the governing equation for a consistent loss model. The entropy change along each streamline is then calculated by assuming that the dissipative force may be a force coming from laminar viscous stresses with inviscid velocity distributions. Both the flow solvers are combined to build a three-dimensional flow field through a few iterations. For an effect of the distortion of H-S flow surface the body forces are computed after each B-B flow calculation is finished. Mizuki's centrifugal impellers are tested numerically. The reliability of the numerical solution compared with experimental data is guaranteed.

• 대한정형외과스포츠의학회지
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• 제3권2호
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• pp.93-97
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• 2004

회전근 개의 전층 파열은 운동, 고정, 약물 등의 치료로 재생되기 어렵다. 파열은 시간이 지나면서 격심한 통증은 없어질 수 있으나, 대부분의 환자에서 어깨나 머리 위로 다시 움직일 때 증상이 재발된다. 작은 파열은 진행할 수 있으며, 광범위한 파열 시 통증이 감소될 수 있으나 점진적인 근력 약화가 동반된다. 치료 받지 않은 회전근 개 파열 환자의 일부는 견관절 관절염이 속발될 수 있다. 보존적 방법으로 치료하여도 증상이 지속될 때, 증상을 호전 시키고 기능을 회복시키는 가장 좋은 방법은 수술적 봉합이다.

• Journal of Dental Anesthesia and Pain Medicine
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• 제22권4호
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• pp.305-314
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• 2022

Introduction: This clinical trial aimed to evaluate the anesthetic effect of the addition of 2 mg (4 mg/ml) of dexamethasone to 2% lidocaine (plain or with 1:80,000 epinephrine). The solutions were injected for a primary inferior alveolar nerve block (IANB) to provide mandibular anesthesia for the endodontic treatment of mandibular molars with symptomatic irreversible pulpitis. Methods: In a double-blinded setup, 124 patients randomly received either of the following injections: 2% lidocaine with 1:80,000 epinephrine, 2% lidocaine with 1:80,000 epinephrine mixed with 2 mg dexamethasone, or plain 2% lidocaine mixed with 2 mg dexamethasone, which were injected as a primary IANB. Ten minutes after injection, patients with profound lip numbness underwent electric and thermal pulp sensibility tests. Patients who responded positively to the tests were categorized as "failed" anesthesia and received supplemental anesthesia. The remaining patients underwent endodontic treatment using a rubber dam. Anesthetic success was defined as "no pain or faint/weak/mild pain" during endodontic access preparation and instrumentation (HP visual analog scale score < 55 mm). The effect of the anesthetic solutions on the maximum change in heart rate was also evaluated. The Pearson chi-square test at 5% and 1% significance was used to analyze anesthetic success rates. Results: The 2% lidocaine with 1:80,000 epinephrine, 2% lidocaine with 1:80,000 epinephrine mixed with 2 mg dexamethasone, and plain 2% lidocaine mixed with 2 mg dexamethasone groups had anesthetic success rates of 34%, 59%, and 29%, respectively. The addition of dexamethasone resulted in significantly better results (P < 0.001, 𝛘² = 9.07, df = 2). Conclusions: The addition of dexamethasone to 2% lidocaine with epinephrine, administered as an IANB, can improve the anesthetic success rates during the endodontic management of symptomatic mandibular molars with irreversible pulpitis.

• 한국자기학회지
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• 제16권1호
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• pp.98-101
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• 2006

결정립으로 이루어 진 나노구조 Pb 박막의 전기적 특성을 정상 면저항 측정을 통하여 연구하였다. 나노구조 박막은 저온 상의기판 위에 10nm이하의 두께로 증착되었으며, 1.3K부터 상온까지 박막의 온도를 변화시키면서 정상 면저항의 변화를 측정하였다. 열처리 온도에 따라 정상 면저항은 비 단조적하며 비가역적인 변화를 보였으며, 이러한 변화들은 열처리에 따른 나노구조 박막을 구성하고 있는 Pb 결정립의 크기변화로써 이해할 수 있다.