• 한국펄프종이공학회:학술대회논문집
• /
• 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.2
• /
• pp.381-386
• /
• 2006

Many different types of bleaching chemicals and processes have been globally used for deinked pulp. Besides chlorine-free bleaching chemicals, hydrogen peroxide, and sodium dithionite that could be used without restriction for almost all types of fibers, chlorine-containing chemicals such as chlorine dioxide and sodium hypochlorite have also used throughout the world. Even though hydrogen peroxide is commonly used in newsprint, it could not effectively increase brightness. Experimental evaluation on the possibility of using formamidine sulfinic acid (FAS), a reducing agent, for bleaching a wood-containing deinked pulp has been carried out in this study. The effect of bleaching efficiency for FAS on operational conditions and chemical concentrations compaired to hydrogen peroxide in one and two stages was studied. FAS bleaching showed higher brightness at high temperature and low consistency, and vice versa for peroxide one. Bleaching with sodium silicate and DTPA in FAS and peroxide stage showed better results than cases without them. Sodium silicate and chelant seemed minimize the influence of transition metal ions, including manganese and iron ions, which induce both bleaching agents to decompose. As a result, FAS as a reducing agent seems more effective than hydrogen peroxide for increasing brightness and reducing yellowness. FAS and FAS sequence seemed more efficient than the other two stages of bleaching sequences with regard to the best brightness level obtained. When bleaching was conducted with FAS, COD load was just about one-third compared to peroxide, and brightness stability of the bleached pulp appeared better than peroxide after UV light irradiation.

• Restorative Dentistry and Endodontics
• /
• 제49권2호
• /
• pp.14.1-14.13
• /
• 2024

This study aimed to answer the question through a systematic review: Can carbamide peroxide be as effective as hydrogen peroxide and cause less in-office bleaching sensitivity? A literature survey was performed in PubMed/MEDLINE, Embase, Scopus, ISI Web of Science, and gray literature. Primary clinical trials that compared the efficacy or the in-office bleaching sensitivity between carbamide and hydrogen peroxides were included. The risk of bias was evaluated using the RoB2. The certainty of the evidence was assessed using the GRADE approach. DPI training significantly improved the mean scores of the dental undergraduates from 7.53 in the pre-DPI-training test to 9.01 in the post-DPI-training test (p < 0.001). After 6 weeks, the mean scores decreased marginally to 8.87 in the retention test (p = 0.563). DPI training increased their confidence level from 5.68 pre-DPI training to 7.09 post-DPI training. The limited evidence suggests that the 37% carbamide peroxide may be similarly effective to the 35% hydrogen peroxide for bleaching teeth in-office and causes less bleaching sensitivity. However, more well-designed split-mouth clinical trials are necessary to strengthen the evidence.

• 한국항공우주학회지
• /
• 제37권7호
• /
• pp.717-728
• /
• 2009

로켓추진기관에 있어 과산화수소는 단일추진제와 이종추진제의 산화제로 사용되어 왔다. 과산화수소는 추력기용으로 사용된 최초의 단일추진제였으나, 후에 보다 비추력이 높고 저장성이 좋은 하이드라진으로 대체되었고, 터보펌프 구동용으로는 여전히 사용되어지고 있다. 이종추진제의 산화제로서는 1970년대까지 사용되었다. 1990년대에 들어서 저비용, 친환경적인 개발이 중요하게 대두되면서 과산화수소는 다시 개발자들의 관심의 대상이 되었다. 과산화수소의 저장성능이 과거에 비해 크게 개선되었으며, 케로신/과산화수소를 추진제 조합으로 사용하는 경우 케로신/액체산소를 사용하는 경우에 비하여 가속성능은 다소 떨어지나, 높은 추진제밀도와 O/F 비로 인하여 유사한 가속성능을 얻을 수 있으며, 연소생성물 역시 더욱 청정하였다.

• 한국양식학회지
• /
• 제11권2호
• /
• pp.223-230
• /
• 1998

This study was carried out for the purpose of developing environmental friendly and effective chemical treatment method for the disease control in the land-based flounder culture which is industrially popular in the coastal area in Korean. The chemicals such as flounder, Paralichthys olivaceus and their effects on the fish based on the 24hr-$LC_{50}$, $LT_{50}$, 24-hour survival rate at each experimental concentration, recovery rate of the survived individual from chemical treatment, and the histological change of the gill after chemical treatment were investigated and analyzed. The 24hr-$LC_{50}$ was 321.65 ppm for formalin, 419.62 ppm for chlorine dioxide, and 395.97 ppm for hydrogen peroxide, respectively. The $LT_{50}$ was 15-hour for formalin, 17-hour for chlorine dioxide and 24-hour for hydrogen peroxide, respectively. Fishes exposed to the experimental concentration of three chemicals were quickly susceptible in the order of formalin, chlorine dioxide and hydrogen peroxide with a trend of shorter half lethal time at higher concentration. Initial survival rate of the flounder soon after chemical treatment was the highest in the hydrogen peroxide treatment compared with the other two chemicals. The histological damage by the hydrogen peroxide treatment was negligible compared with the other two chemicals. Accordingly, hydrogen peroxide treatment showed the lowest toxicity compared with the other two chemicals to the experimental fishes.

• 생물환경조절학회지
• /
• 제18권3호
• /
• pp.297-301
• /
• 2009

본 연구는 파프리카 재배농가에서 과산화수소를 이용하여 여름철 고온극복에 관한 연구수행 결과이다. 고온기 과산화수소(순도 30%)를 0.3%로 희석하여 5일주기로 살포한 결과 파프리카의 엽이 두꺼워지고 기공저항 속도가 낮아 순조로운 증산작용이 가능하였다. 주당 착과수는 무처리에 비하여 약 2개가 많았다. 또한 과산화수소처리에 따라 엽내 과산화수소량이 증가하는 경향이었고, 항산화효소인 catalase와 peroxidase의 활력이 증가되었다. 여름철 파프리카 재배에서 가장 많이 발생하는 흰가루병 방제를 위하여 농약사용이 불가피한 상황이지만 생산물의 농약잔류 등으로 사용에 많은 제한이 있는 현 상황에서 과산화수소의 주기적인 이용으로 흰가루병을 방제할 수 있고 생산량도 높일 수 있어 금후 파프리카 재배농가의 많은 이용이 기대 된다.

• 전기화학회지
• /
• 제23권3호
• /
• pp.73-80
• /
• 2020

과산화수소를 이용한 펜톤(Fenton)산화법은 수처리 및 토양 복원분야에서 활용되는 친환경 산화방법이다. 이 방법으로 오염물질을 제거할 때, 오염물의 농도에 따라 과산화수소의 농도를 적절하게 조절하는 것이 상당히 중요하다. 이에 본 연구에서는 HRP (horseradish peroxidase) 효소를 이용한 전기화학적 바이오센서를 제조하고 효소의 활성과 과산화수소의 검출 특성에 대한 연구를 수행하였다. SPCE (Screen Printed Carbon Electrode)의 작업 전극 표면에 키토산과 AuNP를 이용하여 HRP를 전착하였다. 이 후, 전위주사법(CV)과 전기화학적 임피던스 분광법(EIS)을 이용하여 효소의 고정화를 확인하였다. 또한 시간대전류법(CA)과 UV 분광법으로부터 HRP 효소의 활성을 확인하였다. 본 연구에서 제조한 바이오센서를 PBS 전해질에 담그고 과산화수소를 적정하여 CA 분석으로부터 전극에서 발생하는 전류를 측정하였다. 발생 전류는 과산화수소의 농도에 대하여 선형적으로 증가하였으며, 전류로부터 과산화수소의 농도를 예측할 수 있는 검정곡선을 도출하였다.

• Journal of Microbiology and Biotechnology
• /
• 제18권5호
• /
• pp.983-989
• /
• 2008

Human insulin is a hormone well-known to regulate the blood glucose level. Recombinant preproinsulin, a precursor of authentic insulin, is typically produced in E. coli as an inactive inclusion body, the solubilization of which needs the addition of reducing agents such as $\beta$-mercaptoethanol. To make authentic insulin, recombinant preproinsulin is modified enzymatically by trypsin and carboxypeptidase B. The effects of $\beta$-mercaptoethanol on the formation of human insulin derivatives were investigated in the enzymatic modification by using commercially available human proinsulin as a substrate. Addition of 1 mM $\beta$-mercaptoethanol induced the formation of various insulin derivatives. Among them, the second major one, impurity 3, was found to be identical to the insulin B chain fragment from $Phe_1$ to $Glu_{21}$. Minimization of the formation of insulin derivatives and concomitant improvement of the production yield of human insulin were achieved by the addition of hydrogen peroxide. Hydrogen peroxide bound with $\beta$-mercaptoethanol and thereby reduced the negative effects of $\beta$-mercaptoethanol considerably. Elimination of the impurity 3 and other derivatives by the addition of over 10 mM hydrogen peroxide in the presence of $\beta$-mercaptoethanolled to a 1.3-fold increase in the recovery efficiency of insulin, compared with those for the case without hydrogen peroxide. The positive effects of hydrogen peroxide were also confirmed with recombinant human preproinsulin expressed in recombinant E. coli as an inclusion body.

• 동의생리병리학회지
• /
• 제20권6호
• /
• pp.1524-1529
• /
• 2006

The fruits of Cornus officinalis have been used in traditional Oriental medicine for treatment of inner ear diseases, such as tinnitus and hearing loss. In the present study, we showed that the ursolic acid obtained from Corni fructus protected HEI-OC1 auditory cells from hydrogen peroxide cytotoxicity in a dose-dependent fashion. In addition, to investigate the protection mechanism of ursolic acid on hydrogen peroxide cytotoxicity toward HEI-OC1, we measured the effects of ursolic acid on lipid peroxidation and activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) in hydrogen peroxide treated cells. Ursolic acid (0.05 - 2 ${\mu}g/ml$) had protective effect against the hydrogen peroxide-induced HEI-OC1 cell damage and reduced lipid peroxidation in a dose-dependent manner. Pre-treatment with ursolic acid significantly attenuated the decrease in activities of CAT and GPX, but SOD activity was not affected by the ursolic acid or hydrogen peroxide. These results indicate that ursolic acid protects hydrogen peroxide-induced HEI-OC1 cell damage through inhibition of lipid peroxidation and induce the antioxidant enzymes CAT and GPX.

• 동의생리병리학회지
• /
• 제25권2호
• /
• pp.294-299
• /
• 2011

The purpose of this study is to investigate effects of Red Ginseng-Ejung-tang (RE) on nitric oxide (NO) and hydrogen peroxide production in RAW 264.7 mouse macrophages induced by lipopolysaccharide (LPS). Cell viability was measured by modified MTT assay. NO production was measured by Griess reagent assay. Hydrogen peroxide production was measured by dihydrorhodamine 123 (DHR) assay. RE did not show cell toxicity against RAW 264.7 for 24 hr incubation at the concentrations of 10, 25, 50, 100, and $200{\mu}g/mL$ in RAW 264.7. RE significantly inhibited NO production for 24 hr incubation at the concentrations of 10, 25, 50, and $100{\mu}g/mL$ in RAW 264.7 (P < 0.05). RE significantly inhibited the LPS-induced production of NO for 24 hr incubation at the concentrations of 10, 25, 50, and $100{\mu}g/mL$ in RAW 264.7 (P < 0.05). RE significantly inhibited the LPS-induced production of hydrogen peroxide for 16, 24, 40, 48, 64, and 72 hr incubation at the concentrations of 50, 100, and $200{\mu}g/mL$ in RAW 264.7 (P < 0.05). These results suggest that RE has anti-inflammatory property related with its inhibition of NO and hydrogen peroxide production in LPS-induced macrophages.

• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2012년도 제38회 춘계학술대회논문집
• /
• pp.100-103
• /
• 2012

친환경 추진제를 사용하는 추력기의 성능 향상을 위해서 미소량의 연료를 첨가하는 블렌딩 기법을 적용하였다. 친환경 추진제로는 90 wt.% 과산화수소를 사용하였으며, 혼합하는 연료는 에탄올을 사용하였다. 혼합비는 98 wt.% 과산화수소의 이론 성능을 상회하는 성능을 갖는 50으로 정하였다. 실험 결과 에탄올 블렌딩한 과산화수소의 반응기 온도가 과산화수소의 단열 분해 온도보다 높았다. 따라서 에탄올 블렌딩을 통해서 성능 증대를 꾀할 수 있었다. 또한 다양한 촉매 및 지지체의 비교를 통해 에탄올 블렌딩한 과산화수소 분해 및 연소에 적합한 촉매 조합을 파악하였다. 실험 결과 백금 촉매가 적합하다고 판단되며 이산화망간 촉매는 재사용 시 불안정성이 증가하였다. 고온 안정성이 높은 ${\alpha}-Al_2O_3$를 지지체로 사용할 경우 촉매의 분해 성능이 낮아 매우 불안정한 성능을 보였다.