• Journal of the Korean Chemical Society
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• v.29 no.2
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• pp.178-182
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• 1985

The purpose of this study was to develop a separation method of Zn(II), Cu(II) and Mg(II), by ion exchange chromatography using cation exchange resion (Dowex 50w${\times}$8, 80-100 mesh) and anion exchange (Amberlite IRA-400). Ion exchange resions were packed into 25 ${\times}$ 2cm ID column and flow rate was controlled to 0.30 ml/min. Good eluents for separation of nonferrous metal ions such as Zn(II), Cu(II), Mg(II) were as follow: 0.5M $NaNO_3$ (pH 3.1), 0.2~0.5M HCl + 50~60% Acetone, and 1M HAc + 0.1M NaAcf(pH 3.7) aqueous solution. The mixed solution of 0.1M NaAc(pH 3.7), 0.5M HCl + 50% Acetone were found to be the best eluent for step elution. Analysis of metals were determined by atomic absorption spectrophotometer. In addition, separated Zn(II) fraction was obtained by eluted with 0.12N HCl and 1.5N $NH_4OH$ aqueous solution. This solution was titrated by the E. D. T. A.

• Clinics in Shoulder and Elbow
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• v.20 no.3
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• pp.153-161
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• 2017

Background: This study was conducted to compare the clinical and radiological outcomes of the locking hook plate fixation (HP) technique and the single tight rope (TR) technique applied for acute high-grade acromioclavicular (AC) joint separations. Methods: Between 2009 and 2014, 135 consecutive patients with acute AC joint separation Rockwood types III, IV, and V were subjected to surgical reconstruction. One hundred fourteen patients (84.4%) were available for retrospective evaluation. Of them, 62 and 52 were treated using the single TR group and clavicular HP group techniques, respectively. The visual analogue scale, Constant, American Shoulder and Elbow Surgeons (ASES), and Taft scores were used for clinical assessment. Postoperative shoulder range of motion was also assessed. An anteroposterior radiograph of the coracoclavicular distance (CCD) was obtained to evaluate the radiographic signs of recurrence. Results: The TR group patients had better Constant, ASES, and Taft scores than the HP group patients. The loss of reduction in terms of the CCD did not differ between groups. Subacromial osteolysis was observed in 34.6% of the cases in the HP group. However, there were no significant differences in the clinical outcomes between the patients with and without osteolysis in the HP group. Subcoracoid osteolysis, drill tunnel widening, and metal displacement were observed in 3.2%, 22.6%, and 4.8% of the cases in the TR group, respectively. Conclusions: The single TR technique was relatively more effective at treating acute high-grade AC joint injuries than the HP fixation technique (level of evidence: therapeutic; retrospective comparative study, Level III).

• Clinics in Shoulder and Elbow
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• v.24 no.4
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• pp.209-214
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• 2021

Background: The treatment for acromioclavicular joint injuries (ACJI) ranges from a conservative approach to extensive surgical reconstruction, and the decision on how to manage these injuries depends on the grade of acromioclavicular (AC) joint separation, resources, and skill availability. After a thorough review of the literature, the researchers adopted a simple cost-effective technique of AC joint reconstruction for acute ACJI requiring surgery. Methods: This was a prospective single-center study conducted between April 2017 and April 2018. For patients with acute ACJI more than Rockwood grade 3, the researchers performed open coracoclavicular ligament reconstruction using synthetic sutures along with an Endobutton and a figure of 8 button plate. This was followed by AC ligament repair augmenting it with temporary percutaneous AC K-wires. Clinical outcomes were evaluated using the Constant Murley shoulder score. Results: Seventeen patients underwent surgery. The immediate postoperative radiograph showed an anatomical reduction of the AC joint dislocation in all patients. During follow-up, one patient developed subluxation but was asymptomatic. The mean follow-up period was 30 months (range, 24-35 months). The mean Constant score at 24 months was 95. No AC joint degeneration was noted in follow-up X-rays. The follow-up X-rays showed significant infra-clavicular calcification in 11 of the 17 patients, which was an evidence of a healed coracoclavicular ligament post-surgery. Conclusions: This study presents a simple cost-effective technique with a short learning curve for anatomic reconstruction of acute ACJI. The preliminary results have been very encouraging.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.529-532
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• 2004

The spatio-temporal variation of Infra Red(IR) emission images were obtained from a real 3-dimensional discharge space of a surface discharge type, alternating current plasma display panel(AC PDP) cell with the Ne-Xe(4%) 400Torr gas mixture. IR emissions were observed in each period of the ADS(Address and Display Separation) driving scheme with ramp initializing waveform using an images intensified charge coupled device(ICCD) camera. The roles of each electrode were identified and it was compared with the results of the discharge simulation and of the wall charge distributions measured by the electro-optic technique.

• Proceedings of the KSR Conference
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• 2000.11a
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• pp.712-719
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• 2000

This paper presents a new algorithm to analyze a train voltages of multi-trains in auto-transformer-fed AC railway systems, using electrical equivalent change. The train current will be divided into circulation and return currents, and these current values are the same. By evaluating each current independently, the result will be more precise. The train current flows through the all auto-transformer corresponding to track impedance. In analyzing the railway system, the algorithm is based on the K.C.L, K.V.L, superposition and circuit separation method. Multi-train's voltages are determined by calculating the catenary voltage at each train's position and adding up these train's voltage drop. Case studies use a field operational data, show that tile proposed method is easily applied.

• 한국정보디스플레이학회:학술대회논문집
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• 2000.01a
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• pp.97-98
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• 2000

This paper deals with the relationship between the addressing and the display in ac-PDP. Especially, deals with the transfer probability of surface discharge according to addressing voltage (Va), blocking voltage(Vg) in addressing period and the characteristics of luminance according to sustain voltage(Vs) in sustaining period with ADS(Address Display period Separation) driving method.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.149-152
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• 2000

AC impedance measurements on poly-p-phenylenevinylene (PPV) LEDs in the frequency range between 10 Hz and 10$\^$6/ Hz were carried out. The complex-plane impedance spectra indicate that PPV devices can be represented by equivalent circuits that corresponds to the bulk and interfacial regions at high and low frequencies, respectively. As a result of complex impedance analysis through the separation of bulk and interfacial region impedances, increase of forward bias in Al/PPV/ITO devices gave rise to relative decrease of the interfacial region impedance. Above the electric field of 10$\^$6/ V/cm the PPV device showed a space charge limited current (SCLC) conduction. The dependence of the transport mechanism and dielectric properties on the applied bias voltage is discussed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.5
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• pp.800-805
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• 2017

The accelerated thermal ageing of CSPE (chlorosulfonated polyethylene) was carried out for 16.82, 50.45, and 84.09 days at $110^{\circ}C$, equivalent to 20, 60, and 100 years of ageing at $50^{\circ}C$ in nuclear power plants, respectively. As the accelerated thermally aged years increase, the insulation resistance and resistivity of the CSPE decrease, and the capacitance, relative permittivity and dissipation factor of those increase at the measured frequency, respectively. As the accelerated thermally aged years and the measured frequency increase, the phase degree of response voltage vs excitation voltage of the CSPE increase but the phase degree of response current vs excitation voltage decrease, respectively. As the accelerated thermally aged years increase, the apparent density, glass transition temperature and the melting temperature of the CSPE increase but the percent elongation and % crystallinity decrease, respectively. The differential temperatures of those are $0.013-0.037^{\circ}C$ and, $0.034-0.061^{\circ}C$ after the AC and DC voltages are applied to CSPE-0y and CSPE-20y, respectively; the differential temperatures of those are $0.011-0.038^{\circ}C$ and $0.002-0.028^{\circ}C$ after the AC and DC voltages are applied to CSPE-60y and CSPE-100y, respectively. The variations in temperature for the AC voltage are higher than those for the DC voltage when an AC voltage is applied to CSPE. It is found that the dielectric loss owing to the dissipation factor($tan{\delta}$) is related to the electric dipole conduction current. It is ascertained that the ionic (electron or hole) leakage current is increased by the partial separation of the branch chain of CSPE polymer as a result of thermal stress due to accelerated thermal ageing.

• 한국초전도학회:학술대회논문집
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• v.14
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• pp.34-34
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• 2004

• Journal of the Korea Concrete Institute
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• v.24 no.4
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• pp.445-452
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• 2012

In this study, experimental research was carried out to evaluate the structural performance of the reinforced concrete beam using strengthening materials (embedded FRP rod, metal fittings) in existing reinforced concrete buildings. Seven reinforced concrete beams comprised of retrofitted embedded FRP rod (BCR series), embedded FRP rod with metal fittings (BCR-AC series), and standard specimen (BSS) were constructed and tested under monotonic loading. Design parameters of test specimens were amount of embedded FRP rod and metal fittings. The test results showed that the maximum load carrying capacity of specimens with embedded FRP rod (BCR series) and embedded FRP rod with metal fittings (BCR-AC series) increased by 21~55% and 21~63%, respectively, in comparison with the standard specimen BSS. BCR series test specimens failed by the adhesion slip and concrete cover separation. BCR-AC series test specimens failed by the adhesion slip due to the confining effect of metal fittings.