• The Journal of Korean Academy of Prosthodontics
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• v.55 no.2
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• pp.151-155
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• 2017

Purpose: The aim of this study was to evaluate screw removal torque of the two-piece zirconia abutment with the novel titanium component compared to the conventional one-piece titanium abutment in the internal connection implant before and after dynamic cyclic loading. Materials and methods: Two types of the abutment assemblies with internal connection were prepared and divided into the groups; titanium abutment-titanium abutment screw assemblies as control, and zirconia abutment-titanium socket-titanium abutment screw assemblies as experimental group. A total of 12 abutments and implants were used of six assemblies each group. Each assembly was tightened to 30 Ncm. A cyclic load of 300 N at an angle of 30 degrees in reference to the loading axis was applied until one million cycles or failure. The removal torque values (RTVs) of the abutment screws were measured with a digital torque gauge before and after cyclic loading. The RTVs of the pre load and post load were analyzed with t-test, and P-values < .05 were considered statistically significant. Results: The assemblies of both groups survived all after the dynamic cyclic loading test without screw loosening. The statistically significant differences were found between the mean RTVs before and after the cyclic loading in both groups (P < .05). The RTV differences for the control and the experimental group were $-7.25{\pm}1.50Ncm$ and $-7.33{\pm}0.93Ncm$, respectively. Statistical analysis revealed that the RTV differences in both groups were not significantly different from each other (P > .05). Conclusion: Within the limitation of this study, the two-piece zirconia abutment with the titanium component did not show a significant RTV difference of the abutment screw compared to the titanium abutment after dynamic cyclic loading.

• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.4
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• pp.574-579
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• 2010

The baseline wander is most fatal noise, because it obstructs reliable diagnosis of cardiac disorder. Thus, in this paper, the morphology-pair is proposed for estimation of baseline wander except P, T-wave and QRS-complex. Proposed Morphology-pair is able to except P, R, T-wave which have characteristics of local maxima. Likewise Q, S-wave such as local minima are excepted by proposed Morphology-pair. The final baseline wander eliminated ECG signal is deducted by subtraction of original ECG and estimated baseline wander. The experimental results based on the MIT/BIH database show that the proposed algorithms produce promising results.

• International Journal of Highway Engineering
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• v.9 no.3
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• pp.75-82
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• 2007

Washed wastewater generated from the intermittent cleaning process of the three tunnel sites located in the Seoul area showed high concentrations of SS, $COD_{Cr}$, T-N, $NH_3-N$, $NO_3-N$, Zn, Cu, Cr(+6), Mn, Mg, Phenol, $CN^-$ and E-Coli based on the water quality analysis. These characteristics of the deteriorative wastewater depend on the sampling method, cleaning frequency, released amount of washing water, inner material of tunnel wall, traffic volume, and type of drainage systems. Gravitational separation experiment of SS with collected tunnel wastewater showed considerable removal of pollutants such as 80% of $COD_{Cr}$, 30% of T-N and 90% of T-P simultaneously. GAC isotherm test was conducted to remove dissolved portion of the pollutants, and resulted in high removal efficiencies above 80% of $COD_{Cr}$, T-N, Zn, Cu, Mn, Phenol, CN in the experimental condition of GAC dosage of $50g/1/{\ell}$.

• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.1
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• pp.132-137
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• 2003

This study was carried out to investigate removal character of nitrogen and phosphorus with injection time of acetic acid on SBR, which is one of the biological treatment process. Wastewater used in experiment period was swine wastewater with character, relatively lower organic material concentration than nitrogen concentration. In the experiment with injection time of acetic acid, run 1 wasn't injected acetic acid during the anoxic period, and run 2 was injected intermittently acetic acid during the anoxic period of 15 hours. And run 3 was injected intermittently during the anoxic period of 3hours from end of wastewater filling. And filing time of the wastewater was 20hour from run 1 to run 3. In the study, the highest removal efficiency of organic and nitrogen were obtained by the operating condition of Run 2(the ratio of mixing/aeration time : 16.5/5.5, injection time of acetic acid : 15hours) and T-P was obtained by the operation condition of Run 3(the ratio of mixing/aeration time : 16.5/5.5, injection time of acetic acid : 3hours),and removal efficiency of $BOD_5$, $COD_{Mn}$, $COD_{Cr}$, T-N and T-P in the treated water was 96.1%, 87.7%, 90.6%, 86.6% and 84.5%, respectively.

• The Korean Journal of Zoology
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• v.36 no.1
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• pp.109-115
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• 1993

본연구는 북방산개구리 여포난자의 자발적 성숙과 관련된 몇가지 요인들에 대해 조사하였다. 자발적 성숙을 일으키는 여포에서 여포조직을 제거하여 denuded 난자를 만든다음 배양했을 때에는 자발적 성숙을 일으키지 않았다. 이들 denuded 난자에 frog pituitary homogenate(FPH, 0.05 gland/ml)를 처리하여도 역시 성숙이 일어나지 않았으나 progesterone(P4, 0.5 Ig/ml)을 처리하였을 때에는 성숙이 일어났다. 동면기간에 여포들이 생성하는 P4와 testosterone(T)의 양을 측정해본 결과 동면초에는 비슷한 양의 P4와 T를 생성하였으나 후기에는 P4만 생성하고 T는 거의 생성하지 않았다. 배양액에 estradiol을 첨가하면 농도에 의존하여 FPH에 의해 촉진된 P4의 생성을 억제할 뿐 아니라 성숙도 비가역적으로 억제하였다. 배양액에 첨가한 hvpoxanthine은 CAMP와 항진적으로 난자의 성숙을 억제하였다. 이러한 결과들은 자발적 성숙과정에 여포세포와 P4/T 비율의 증가가 중요한 요인이 된다는 것과 일반적인 난자성숙억제제는 자발적 성숙을 역시 억제한다는 것을 보여준다.

• Journal of the Korea Organic Resources Recycling Association
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• v.6 no.1
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• pp.13-20
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• 1998

Rhodospirillum rubrum N-1 was inoculated to manipulated swine wastewater of 20,000 mg/L as Biochemical Oxygen Demand (BOD) to study the effect of aeration on swine wastewater deodorization. Biological and physico-chemical parameters were determined at 1 day interval for 9 days. Removals of BOD, volatile fatty acids (VFAs), and phosphate were 54.6%, 87.0%, and 54.5%, respectively. No significant changes were observed in the concentrations of total nitrogen, total phosphorus, nitrate, nitrite, hydrogen sulfide, and mercaptane.

• Resources Recycling
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• v.7 no.3
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• pp.11-16
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• 1998

Simulated waste liquid containing 50 ppm cobalt ion was t$\xi$sted by precipitate flotation using a sodium lauryl sulfate as a c collector. The effects of initial cobalt ion concentration, pH, surfactant concentration, flotation time, gas flow rate and foreign i ions on removal efficiency of cobalt ion were studied. Pretreatment of the waste liquid with 35% $H_2O_2$, prior to precipitate f flotation made shin of optimal flotation pH from the strong alkalinity to weak alkaline range and made a favorable flotation of c cobalt ion in wide range of pH. For the result of this experiment, 99.8% removal efficiency was obtained on the conditions of initial coball ion concentration 50 ppm, pH 9.5 gas flow rate 70 mllmin, flotation time 30 min. The simulate ion was fanned t to be the most harmful ion against removal of cobalt by precipitate flotation of the species which were tested The presence of 0.1 M of $SO_4^{2-}$ ion decreased remo,때 $\xi$폐iciency of cobalt to 90% while the cobalt were almost entirely removed in the a absence of sulfate ion.

• Korean Journal of Food Science and Technology
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• v.7 no.1
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• pp.30-36
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• 1975

The extraction efficiency of orange-yellow pigment from the Gardenia was greatly depended upon the extraction time, extraction temperature, volume of solvent used and fat contents of the Gardenia. From the experimental results, the amounts of extracted pigment (P) was proportional to the $log\;t^{\;1{\cdot}15}$ of extraction time$(t;\;0{\sim}60\;min.)$, the $log\;T^{3{\cdot}73}$ of extraction temperature$(T;\;5{\sim}60^{\circ}C)$, the $log\;S^{3{\cdot}7}$ of volume of solvent$(S;\;5{\sim}50\;ml)$, and the -4X of fat contexts of sample $(X;\;0{\sim}0.\;15)$ at $18^{\circ}C$ for 10 minutes. Finally, the modified empirical equation was derived as follow; $P{\simeq}1.15\;log\;t+3.73\;log\;T+3.7\;log\;S-4X-6.4$ In addition to that, the most optimum conditions of pigment extraction were determined as 30 minutes of operation time, $40^{\circ}C$ of temperature. Deffated Gardenia was more productive than natural Gardenia in the pigment extraction.

• Journal of environmental and Sanitary engineering
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• v.24 no.1
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• pp.13-24
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• 2009

This study was performed to determine the effect of the influent flow distribution ratio and hydraulic retention time(HRT) on removal of organic matter, nitrogen and phosphorus when domestic sewage was treated by the advanced step aeration(ASA) process. Results of the experiment for the determination of the optimum influent flow distribution ratio between the anaerobic reactor and the anoxic reactor showed BOD removal efficiencies of above 92.0% at all influent flow distribution ratios from 9:1 to 4:6. The highest T-N removal efficiency was 82.6% at the influent flow distribution ratio of 6:4. On the other hand, the highest T-P removal efficiency was 67.8% at the influent flow distribution ratio of 9:1. Considering both the T-N and T-P removal efficiencies, the influent distribution ratio of 6:4 was considered the optimum. Results of the experiment for the determination of the optimum HRT at the optimum influent flow distribution ratio of 6:4 revealed BOD removal efficiencies better than 92.7% at all HRTs from 12hr down to 6hr. The highest T-N and T-P removal efficiency were 82.6% and 59.5%, respectively both at the HRT of 8hr. In conclusion, the optimum influent flow distribution ratio and HRT for treatment of domestic sewage by the ASA process were determined to be 6:4 and 8hr, respectively.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.29 no.1
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• pp.293-298
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• 2005

Lab scale experimental study was carried out for SBR process, to investigate the effects of influent ship sewage organic compound removal and Bacillus sp. state on design parameters. This process was able to remove nitrogen and phosphorus as well as organic matter efficiently. More than 95% of chemical oxygen demand(COD) were removed. In addition, about 97% of total nitrogen (T-N) was reduced. The total phosphorus(T-P) reduction averaged 93%. The performance load of SBR process was shown to be 0.095kg ${\cdot}$ TOC/$m^{3}$ ${\cdot}$ day. The pH was decreased from 8.1 to 7.0 within 30 min and increased to 7.3 at the end of anoxic stage, and these phenomena were explained. The sluge produced in the SBR process is characterized by low generation rate (about 0.36kg ${\cdot}$ MLSS/kg ${\cdot}$ TOC) and excellent settleability. The number of Bacillus sp. in the SBR was 24.2%, indicating that Bacillus sp. was a predominant species in the reactor.