• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.11 no.2
• /
• pp.138-145
• /
• 1998

The $(Pb_{0.9}Ca_{0.1})TiO_3$[PCT] thin films have been deposited by sol-gel processing on Si-wafer and ITO glass substrates. The creak-free films have been obtained by rapid thermal annealing at $700^{\circ}C$ for 10 minute and characterized by XRD, SEM and electrical measurements. Their tetragonality c/a was 1.041 and grain size was $0.15{\sim}0.2{\mu}m$. When the electrode system of sample was Au/PCT/ITO(MFM) and film thickness was $0.8{\mu}m$, dielectric constant, dielectric loss and Curie temperature were about 149, 0.085 and $449^{\circ}C$ at 10kHz, respectively. Spontaneous polarization $P_s$, remnant polarization $P_r$ and coercive field $E_c$ were about $5.29{\mu}C/cm^2$, $4.15{\mu}C/cm^2$ and 82kV/cm calculated by hysteresis loop.

• Korean Chemical Engineering Research
• /
• v.59 no.1
• /
• pp.118-126
• /
• 2021

The experiments to produce the vaterite type calcium carbonate were conducted for using the waste oyster shell as the recycling resources. Firstly, the oyster shell were calcinated at 800 ℃ for 24 h. Calcinated oyster shell were reacted with the nitric acid solution, and were diluted to 0.1 M Ca(NO3)2 solution. This solution was mixed with 0.1 M Na2CO3 contained 0.1 mol lysine/1 mol CaO at 20 ℃ and 600 rpm mixing condition for 1 h. The reaction products were identified to vaterite type calcium carbonate (84.5% vaterite, 15.5% calcite) by XRD and SEM analysis. Mean particle diameter was 6.87 ㎛, and the lysine content in calcium carbonate was analyzed to 0.1%.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.15 no.1
• /
• pp.9-14
• /
• 1986

Fuji and Jonathan apples were stored at cold room and at CA storage conditions of $3%O_2-2%CO_2$ for Jonathan and $4%O_2-3%CO_2$ for Fuji for 8 months, and then tranferred to air at $20^{\circ}C$, 70%RH to compare the some factors related to texture of the apples stored at different storage conditions during exposure at $20^{\circ}C$. Total pectin content and firmness of the apples reduced, considerably with concomitant increases of water-soluble pectin content and polygalacturonase activity during exposure at $20^{\circ}C$ after storage. And the changes were much more serious in the first 5 days than any other period and in the apples stored at cold room, especially in Jonathan than the apples stored at CA storage conditions. From the sensory test the apples stored at cold room maintained acceptable quality for 5days after removal from storage condition. The acceptability from the test was lenghtened for more than 5 days in Jonathan and more than 10 days for Fuji stored at CA storage conditions. when compared with those of the apples stored at cold room.

• Proceedings of the Korea Crystallographic Association Conference
• /
• 2000.05a
• /
• pp.14-15
• /
• 2000

• Journal of Korean Society of Water and Wastewater
• /
• v.35 no.2
• /
• pp.113-120
• /
• 2021

High voltage impulse (HVI) has been gained attention as an alternative technique that could control the CaCO₃ scale problems encountered in water main, pipe, cooling tower and heat exchanger vessels. The aim of this study was to investigate the effect of electric field (E) and contact time (t) of HVI on reduction of Ca²⁺ concentration at two different temperatures of 25℃ and 60℃. A kinetic model on the effect of E and t was investigated too. As the E and t increased, the Ca²⁺ concentration decreased more than that of the control (= no HVI). The Ca²⁺ concentration decreased up to 81% at 15 kV/cm at 60℃, which was nearly 2 times greater than the control. With these experimental data-set of reduction of Ca²⁺ concentration under different E and t, the kinetic model was developed. The relationship between E and t required to reduce the concentration of Ca²⁺ by 30% was modeled at each temperature. The empirical model equations were; E^0.83· t = 60.3 at 25℃ and E^0.08· t = 1.1 at 60℃. These equations state the products of Eⁿ and t is always constant, which means that the required contact time can be reduced in accordance with the increment of E and vice versa.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.15 no.2
• /
• pp.116-124
• /
• 2011

Purpose: To establish accurate external quality assurance (EQA) test, cross institutional and modality tests were performed using WHO certificated reference material (CRM) and same pooled patients serum. Materials and Methods: Accuracy and precision were evaluated using CRM and pooled patients' serum for AFP, CEA, PSA, CA 125, CA 19-9, T3, T4, Tg, TSH. To evaluate the accuracy and precision, recover test and coefficient variation were measured. RIA test were performed in major 5 RIA laboratory and EIA (CLIA) test were done in 5 major EIA laboratory. same sample of CRM and pooled serum were delivered to each laboratory. Results: In 2009, mean precision of total tumor marker of RIA was $14.8{\pm}4.2%$ and that of EIA(CLIA) was $19.2{\pm}6.9%$. In 2010, mean precision of 5 tumor marker and T3, T4, Tg, TSH was $13.8{\pm}6.1%$ in RIA and $15.5{\pm}7.7%$ in EIA (CLIA). There was no significant difference between RIA and EIA. In RIA, the coefficient variations (CV) of AFP, CEA, PSA, CA 125, T3, T4, TSH were within 20%. The CV of CA 19-9 was over 20% but there was no significant difference with EIA (CLIA) (p=0.345). In recovery test using CRM, AFP, PSA, T4, TSH showed 92~103% of recovery in RIA. In recovery test using commercial material, CEA, CA 125, CA 19-9 showed relatively lower recovery than CRM but there was no significant difference between RIA and EIA (CLIA). Conclusion: By evaluating the precision and accuracy of each test, EQA test could more accurately measured the quality of each test and performance of laboratory.

• Journal of Chest Surgery
• /
• v.24 no.2
• /
• pp.190-196
• /
• 1991

Clinical experience of 48 acute pericarditis with effusion was reviewed and presented. There were 28 male and 20 female patients ranging from 3 years to 77 years old. Malignant effusion; Twenty patients had underlying malignancy. These etiologies were lung ca[8 patients, 40%], breast ca[7 patients 35%], lymphoma[2 patients, 10%], esophageal ca[1 patients, 5%], stomach ca[1 patient, 5%], ovarian ca[1 patient, 5%]. Uremic effusion; 15 patients with renal failure required surgical intervention. Traumatic effusion; 7 patients had traumatic pericarditis. These etiologies were stab wound [5 patients, 71.4%] and aspiration[2 patients, 28.6%]. Pyogenic effusion: 6 patients had pyogenic pericarditis. These etiologies were empyema thoracis[3 patients, 50%], liver abscess[2 patients, 33.3%], pneumonia[1 patient, 16.7%]. The patients were treated by pericardiocentesis, subxiphoid tube drainage, pericardiectomy: 4 of them underwent pericardiocentesis; 37, subxiphoid tube drainage; 5, pericardiectomy. We conclude that subxiphoid tube pericardial drainage was effective for treatment of pericardial effusion.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2003.09a
• /
• pp.520-523
• /
• 2003

강원도 지역의 대표적인 탄산용출수에 대한 수리지구화학적 연구를 통하여 심부 지열 저장지의 온도와 심부환경을 추정하였다. 탄산용출수는 공통적으로 약산성의 pH와 높은 이온함량으로 특징되지만, 화학적으로는 Na-HCO$_3$형, Ca-Na-HCO$_3$형, 그리고 Ca-HCO$_3$형으로 뚜렷이 구분된다. 심부에서 생성된 탄산용출수가 지표로 상승하는 도중에 수반된 지표수 혼합차이로 인해 이런 화학조성의 차이가 유발된 것으로 판단된다. Na-HCO$_3$형 탄산수는 화학 조성상 ‘mature water’의 특징을 보여주는 반면, 다른 두 유형의 탄산수들은 ‘immature water’에 해당하였다. Na-HCO$_3$ 형 탄산수에 대하여 실리카, Na-K 및 Na-K-Ca 지온계를 적용한 결과, 약 l15-157도의 심부저장지 온도가 산출되었으며, 이 결과는 다성분 평형계를 이용한 추정 온도 (약 140-160도)와도 잘 일치하였다. 반면, Ca-HCO$_3$ 형 탄산수들은 지표수와의 혼합 때문에 상대적으로 낮고 넓은 범위의 추정 온도 (약 60-130도)를 나타내었다. 따라서 연구지역 내 탄산용출수의 심부저장지 온도는 Na-HCO$_3$형에 대해서만 타당하게 적용될 수 있으며, 약 140-160도일 것으로 추정된다.

• Textile Coloration and Finishing
• /
• v.9 no.3
• /
• pp.18-26
• /
• 1997

Polyester microfiber fabrics were decomposed at 100, 110, and 12$0^{\circ}C$ in saturated CaO/ethylene glycol solutions(CaO/EG), and the characteristics of decomposition kinetics were discussed in comparison to those by hot aqueous hydroxide solution(NaOH). The Arrhenius pre-exponential factor(A) was 9.17x $10^{14}$/M $sec^{-1}$and the activation energy($E_{a}$) was 8.19kcal/mol. While the A value was 1.947x $10^{14}$/M $sec^{-1}$ and the ($E_{a}$ value was about 15~19kcal/mol in NaOH-PET decomposition reaction. The much higher A value of the CaO/EG-PET decomposition reaction means that CaO/EG-PET decomposition reaction will occur in a less selective fashion in comparison to the NaOH-PET decomposition reaction. On the other hand, the lower ($E_{a}$) value of the CaO/EG-PET decomposition reaction than that of the NaOH-PET decomposition reaction means that CaO/EG-PET decomposition reaction is less sensitive on the variation of temperature than NaOH-PET decomposition reaction.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.5 no.4
• /
• pp.378-385
• /
• 1995

The growth processes of improved methods for MBE, LPE and $\mu$ - PD methods are discussed taking the oxide materials, especially those of Bi - Sr - Ca - Cu family $LiNbO_3$ and $K_3Li_2Nb_5O_{15}$ family as examples. It is suggested that the crystal growth far from equilibr iu m including composition homogeneity has been achieved to satisfy in understanding and controlling the atomic interfaces.