• Applied Chemistry for Engineering
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• v.26 no.1
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• pp.92-98
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• 2015

In this study, phenol-based activated carbons (ACs) were fluorinated at various fluorine partial pressures (0.01~0.03 MPa) and the $Cr^{6+}$ ion adsorption of fluorinated ACs was investigated. According to BET and XPS results, the specific surface area and total pore volume of fluorinated ACs increased by 24.7 and 55.8%, respectively, and fluorine functional groups were introduced to AC surface. The most optimized condition of $Cr^{6+}$ ion adsorption was confirmed at the fluorine partial pressure of 0.02 MPa. And also the removal efficiency of $Cr^{6+}$ ion was up to 98% at 300 mg/L of the initial concentration, and these results showed an approximately three-fold increase compared to that of using untreated ACs. Furthermore, the $Cr^{6+}$ ion adsorption of fluorinated ACs was completed in less than 30 min in contrast with untreated ACs, which was expected to be an increase of the affinity between $Cr^{6+}$ ions and ACs surfaces by fluorination.

• 월간 기계설비
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• s.115
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• pp.83-85
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• 2000

이온 스케일 버스터는 독일의 ION사가 지난 `88년 개발, 지난 `94년 세계특허 획득 및 독일 TUV(기술표준협회)로부터 품질인증마크인 GS마크를 획득한 제품으로 기존의 파이프나 스틸 용기 내부에 발생한 스케일 및 녹 등의 제거는 물론 부식발생을 미연에 방지하는 수처리기이다.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.3
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• pp.32-43
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• 2008

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.129-129
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• 2010

플라즈마 처리를 통하여 수직 합성된 다중벽 탄소나노튜브가 원뿔형 다발이 될 수 있으며 원뿔형 탄소나노튜브 다발은 기존의 구조적, 기계적 성질의 향상과 더불어 향상된 전계방출 능력을 가질 것으로 기대되어 이를 X-선원, 전계방출디스플레이(FED), 유기발광다이오드(OLED) 백라이트 등의 전자빔 원으로 적용하기 위한 연구가 진행되고 있다. 원뿔형 탄소나노튜브 다발의 형상 제어를 통하여 전계방출특성을 향상시킬 수 있으며 이를 위해 원뿔형 탄소나노튜브 다발이 생성되는 메커니즘과 조사되는 플라즈마의 역할에 대해서 이해하는 것이 중요하다. 본 연구에서는 플라즈마 생성부와 조사부를 분리한 유도결합형 플라즈마 원을 사용하여 입사되는 이온의 에너지, 조사량, 입자 종을 독립적으로 제어하였고 이를 통하여 원뿔형 탄소나노튜브 다발이 형성되는 메커니즘과 플라즈마의 역할을 밝혀내었다. 알곤 및 수소 플라즈마 처리에서는 원뿔형 탄소나노튜브 다발이 형성되지 않았으나 질소 및 산소 플라즈마 처리에서는 원뿔형 탄소나노튜브 다발이 형성되었다. 특히 산소 플라즈마 처리가 원뿔형 탄소나노튜브 다발 형성에 효과적이었다. 원뿔형 탄소나노튜브 다발의 형성 메커니즘은 탄소나노튜브의 분극과 쉬스 전기장의 상호작용을 이용한 모델을 사용하여 설명하였다. 질소 및 산소 플라즈마 처리에서는 탄소나노튜브 끝단에 생성되는 C-N, C-O 결합에 의해 향상된 유도 쌍극자와 쉬스 전기장에 의해 탄소나노튜브 끝단이 모여 원뿔형 탄소나노튜브 다발이 생성됨을 밝혀내었다. 산소 플라즈마 처리에서 입사되는 이온의 에너지 조절에 의한 쉬스 전기장 조절과 조사량 조절을 독립적으로 수행하여 원뿔형 탄소나노튜브 다발의 직경 및 높이가 쉬스 전기장 및 조사량에 따라 조절 가능함을 보였다. 이로부터 입사되는 이온의 입자 종, 쉬스 전기장 및 조사량 조절 등의 플라즈마 인자 조절을 통하여 원뿔형 탄소나노튜브 다발의 형상 제어가 가능함을 보였다. 탄소나노튜브의 형상 제어와 더불어 세슘 입자 삽입을 통한 탄소나노튜브의 일함수 감소를 통하여 향상된 전계 방출 특성을 갖는 탄소나노튜브 팁의 제조 가능성을 확인하였다.

• Applied Biological Chemistry
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• v.39 no.3
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• pp.218-221
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• 1996

With a view to increase utility of ethanol fractioned fish skin gelatin as a food source, efforts of additives on physical properties of the gelatin were investigated. The physical properties such as gel strength, melting Point, gelling point and viscosity of both ethanol-treated and untreated gelatins were improved by adding ferric ion, sugar and ethanol to the gelatin sol, but were deteriorated by the added sodium chloride and acids. Insignificant difference in effect of physical properties on additives such as sodium chloride, sugar and ethanol between ethanol-treated and untreated gelatins were not observed. However, the effect of ferric ion and acids on the physical properties of ethanol-treated gelatin has a greater than that of untreated gelatin.

• Journal of Life Science
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• v.13 no.4
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• pp.473-480
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• 2003

We analyzed the patterns of mineral ions and growth responses among symbiotic nitrogen fixing legumes by external nitrogen applications under salt gradients. Glycine max, Phaseolus angularis and Albizzia julibrissin showed remarkable growth inhibition above 40 mM NaCl treatments, but Cassia tora did not exhibit any visible injury symptom up to 100 mM NaCl treatments. As to ionic pattern, the $Na^+$ and $Cl^-$contents in leaves of G. max, P. angularis and A. julibrissin progressively increased with higher contents of external salinity. Compared to other plants, C. tora excluded $Na^+$more efficiently and maintained rather constant ionic contents in spite of high salt levels. With a few exception, these 4 legume plants exhibited better growth by the external nitrogen supply rather than the contribution of symbiotic nitrogen fixation only under saline condition.

• Journal of Dental Rehabilitation and Applied Science
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• v.25 no.4
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• pp.361-374
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• 2009

For successful osteogenesis around the implants, interaction between implant surface and surrounding tissue is important. Biomechanical bonding and biochemical bonding are considered to influence the response of adherent cells. But the focus has shifted surface chemistry. The purpose of this study is to evaluate the MC3T3-E1 osteoblast like cell responses of magnesium (Mg) ion implanted titanium surface produced using a plasma source ion implantation method. Commercially pure titanium disc was used as substrates. The discs were prepared to produce four different surface, A: Machine turned surface, B: Mg implanted surface, C: sandblasted surface, D: sandblasted and Mg implanted surface. MC3T3 El osteoblastic like cells were cultured on the disc specimens. Cell adhesion, proliferation, differentiation, and synthesis of extracellular matrix were evaluated. The cell adhesion morphology was evaluated by SEM. RT PCR assay was used for assessment of cell adhesion, proliferation and differentiation. ALP activity was measured for cell differentiation. The results of this study were as follows: 1. SEM showed that cell on Mg ion groups was more proliferative than that of non Mg ion groups. On the machine turned surface, cell showed some degree of contact guidance in aligning with the machining grooves. 2. In RT PCR analysis, osteonectin and c-fos mRNA were more expressed on sandblasted and Mg ion implanted group. 3. ALP activity was not significantly different among all groups. Within the limitations of this study, the following conclusions were drawn: It might indicate Mg ion implanted titanium surface induce better bone response than non Mg ion groups.

• Korean Journal of Environmental Biology
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• v.39 no.4
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• pp.550-558
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• 2021

In a radiotracer study, the bioaccumulation and efflux of metals in earthworms (Eisenia fetida) exposed to soil spiked with ZnO and Ag nanoparticles (AgNP) were compared to those exposed to soil spiked with ionic Zn and Ag. Additionally, the bioavailability and chemical mobility of nano- and ionic metals in the soil were estimated using the sequential extraction method and compared to the bioaccumulation factor(BAF). The BAF for ZnO (0.06) was 31 times lower than that for Zn ions (1.86), suggesting that ZnO was less bioavailable than the ionic form in contaminated soil. In contrast, the BAFs for two types of AgNPs coated with polyvinylpyrrolidone (0.12) or citrate (0.11) were comparable to those of ionic Ag (0.17). The sequential extraction of metals from the soil suggests that the chemically mobile fractions in the Zn ion treatment were higher(35%) than those (<20%) in the Ag ion treatment, which was consistent with the greater BAFs in the former than the latter. However, the chemical mobility in the ZnO treatments did not predict bioavailability. The efflux rates of Ag (3.2-3.8% d^-1) in the worms were 2-3×those(1.2-1.7% d^-1) for Zn.

• ANNALS OF ANIMAL RESOURCE SCIENCES
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• v.30 no.2
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• pp.69-78
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• 2019

The objective of this study was to investigate the quality properties of sausages added with the atmospheric pressure plasma treated extract of Perilla frutescens Britton var. acuta Kudo (red perilla). The lyophilized powder of red perilla extract treated by atmospheric-pressure plasma contained 7.5 g kg^-1 nitrite. Sausage samples were manufactured with the addition of sodium nitrite (Control), celery powder (Celery), or plasma-treated extract of red perilla (PTP) to obtain nitrite concentration of 70 mg kg^-1. The residual nitrite content was the lowest in PTP during storage for 21 days at 4℃ (p<0.05). The total aerobic bacteria counts were higher in PTP than in Control and Celery during storage at 4℃ (p<0.05). Malondialdehyde content of sausages was significantly lower in PTP than in Control and Celery during storage (p<0.05). PTP showed the lowest L^* value and the highest b^* value among the tested sausage samples during storage (p<0.05). PTP received the low scores in all the sensory properties of sausages because of its inherent color and flavor. The results suggested that the plasma-treated extract of red perilla was an unsuitable natural nitrite source for cured meat products because of its adverse effect on sensory quality. However, natural nitrite source with increased nitrite content can be produced by the treatment of the natural plant extract with atmospheric-pressure plasma.

• Journal of Astronomy and Space Sciences
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• v.16 no.2
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• pp.285-292
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• 1999

To determine a geographical position by GPS signal, the effect of the ionosphere must be considered to improve accuracy. This has led us to continuously try to find the TEC of the ionosphere by using the GPS signal. So far the way to find TEC has been developed and the information obtained from this can be used not only to increase the accuracy of determining the position, but also to study the ionosphere. In this research, the TEC MAP over Korea was obtained by using the data collected from eight GPS stations around the Far East Asia, which is the common way to represent TEC over some regional or global region.