• 멤브레인
• /
• 제33권3호
• /
• pp.137-147
• /
• 2023

본 연구에서는 현탁중합을 통해 이온교환입자를 합성하였다. 또한 음이온 교환막을 제조하기 위해 brominated poly(phenylene oxide) (Br-PPO)로 교환막 합성을 진행하였으며, 합성한 이온교환입자를 Br-PPO에 첨가하여 음이온 교환막에 성능을 향상시키고자 하였고, 이를 적용하여 음이온 교환막 연료전지 시스템의 성능 평가를 진행했다. 이온교환입자는 FT-IR, TGA 및 UTM을 통해 구조 분석, 열적 기계적 특성을 평가하였다. Br-PPO는 NMR을 통해 화학적 구조 분석 및 합성여부를 확인하였고, 음이온 교환막 연료 전지 셀 테스트를 진행하기 전 이온전도도와 이온교환용량, 팽윤도 및 수분함수율을 측정해 연구되고 있는 다른 음이온 교환막들과 비교를 통해 성능을 평가했다. 최종적으로 가장 성능이 우수했던 이온교환입자를 0.7 wt%를 첨가한 Br-PPO-TMA- SDV 음이온 교환막을 연료전지 시스템에 도입하여 상용 막인 FAA-3-50과 성능을 비교했다.

• 한국환경보건학회지
• /
• 제50권3호
• /
• pp.201-211
• /
• 2024

Background: Organic ultraviolet (UV) filters are widely used in sunscreen products and have been identified as an emerging contaminant. Organic UV filters co-exist with multiple components, but their mixture toxicity remains largely unknown. Objectives: We investigated the toxicity of single and binary mixtures of commonly used UV-filters using the human adrenocarcinoma (H295R) cell line. Methods: After exposure to non-cytotoxic concentrations of avobenzone (AVO), homosalate (HS), octisalate (OS), octinoxate (OMC), and octocrylene (OC), the levels of testosterone (T) and 17β-estradiol (E2) were measured. The median effective concentration (EC₅₀) values for the E2 of the individual substances were used to determine the mixture effect of four binary combinations: OMC+AVB, OMC+HS, OMC+OS, and OMC+OC. The synergistic, additive, and antagonistic effects of the mixture were determined by calculating toxic units (TU). To examine the mechanism of mixture toxicity, eight genes involved in steroidogenesis were analyzed using the real-time polymerase chain reaction. Results: The significant increase in E2 in H295R cells exposed to AVO, HS, OS, OMC, and OC suggest an estrogenic effect of the tested UV-filters. A significant decrease in T was observed in cells exposed to HS and OS. EC₅₀ values for E2 increase were 105 nM for AVO, 110 nM for HS, 120 nM for OS, 55 nM for OMC, and 80 nM for OC. Both binary mixtures consisting of OMC+HS and OMC+OS have synergistic effects. Conclusions: Our results showed that five types of UV-filter substances increase E2 in H295R cells. We examined the mixture toxicity in terms of increased estrogenicity and confirmed that E2 significantly increased when OMC was mixed with a salicylate-based UV-filters. These findings highlight the importance of determining the impact of UV filter mixtures.

• 농업과학연구
• /
• 제3권1호
• /
• pp.77-84
• /
• 1976

최근(最近)에 사료(飼料)의 요구량(要求量)이 급증(急增)되고 사료용(飼料用) 호박이 도입(導入) 재배(裁培)되므로서 호박의 사료화(飼料化)에 대(對)한 관심(關心)이 많아졌다. 이에 본시험(本試驗)은 사료용(飼料用) 호박으로 Mammoth pumpkin(C. Maxima), Queensland blue pumpkin(C. Maxima), Korean pumpkin(C. Moschata)으로 부터 밀기울을 0, 10, 20%씩 각각(各各) 첨가(添加)하면서 Silage 제조(製造) 하였으며, 제조후(製造後) 40~60일(日) 사이에 화학적(化學的) 조성분(組成分), pH, 유기산함량(有機酸含量)을 분석(分折)하고 산란계(産卵鷄)에 대(對)한 급여시험(給與試驗)을 하여 호박의 사료적(飼料的) 가치(價値) 및 이용성등(利用性等)을 조사(調査)하고 그 결과(結果)를 아래와 같이 요약(要約)하였다. 1. Silage의 수분함량(水分含量)은 재료(材料)인 호박의 수분함량(水分含量)이 Mammoth pumpkin의 경우(境遇) 약(約) 97%, Queensland pumpkin이 94%, Korean pumpkin이 91%였던 관계(關係)로 상당히 높았으며 Silige제조후(製造後) 성분변화(成分變化)는 가용무질소량(可溶無窒素量)이 약간(約間) 감소(減少)하였을 뿐, 기타(其他)의 성분(成分)은 변화(變化)가 없는 것으로 나타났다. 또한 밀기울을 첨가(添加)하므로서 수분(水分)을 조절(調節)할 수 있었고 영양분(營養分)도 증가(增加)되었으나 이는 단지 밀기울의 성분함량(成分含量)에 좌우(左右)되었다. 또한 Silage의 성분손실량(成分損失量)은 제조후(製造後) 2주(週)에서 1개월(個月)사이에 10%정도(程度)였으며 그후(後) 약간씩 감소(減少)하여 6개월후(個月後)에는 15%정도(程度)였는데 호박을 그대로 저장(貯藏)했을 시(時)는 9월(月)부터 12월(月)사이에는 수분함량(水分含量)이 특(特)히 많은 Mammoth pumpkin을 제외(除外)하고 그 감량(減量)이 심(甚)하지 않았으나 월동(越冬)을 한 2월(月)에는 3종(種)의 호박 거의가 사료가치(飼料價値)를 상실(喪失)하였다. 2. Silage의 품질(品質) 또한 처리구간(處理區問)에는 특별(特別)한 차이(差異)가 없이 pH가 3.8~4.1, 유기산중(有機酸中) 유산(乳酸)이 2.09~2.93%였고 초산(醋酸)이 0.68~1.71%, 낙산(酪酸)은 0%로서 Flieg씨(氏) 평점법(評點法)에 의(依)하면 모두 98~100점(點)으로 양질(良質)의 Silage가 제조(製造)되었다. 3. Mammoth pumpkin silage를 산란계(産卵鷄)에 급여(給與)하여 사료섭취율(飼料攝取率), 산란율(産卵率), 난중(卵重) 및 Haugh unit등(等)을 측정(測定)한 결과(結果), 고형물기준(固形物基準)으로 Silage를 5.0%와 7.5%급여구(給與區)가 가장 좋았고 다음이 2.5%구(區)였으며 10%급여구(給與區)는 대조구(對照區)보다 떨어졌다. (P<0.01). 이는 호박 Sil-age가 신선(新鮮)하므로 기호성(嗜好性)을 증진(增進)시켰고 Vitamin등(等) 풍부(豊富)하여 산란(産卵)을 촉진(促進)시키는 것으로 사료(恩料)되나 10%이상(以上)의 급여(給與)는 양(量)이 너무 많아 효과적(效果的)인 급여(給與)가 못되는 것으로 생각된다. 4. 호박을 이용(利用)하여 양질(良質)의 Silage를 제조(製造)할 수 있었고 또한 산란계(産卵鷄)에 급여(給與)한 결과(結果) 산란율(産卵率)도 증진(增進)되었으나 수분함량(水分含量)이 너무 많은 관계(關係)로 다량(多量)의 Silage가 요구(要求)되므로 가축(家畜)의 기본사료(基本飼料)로는 적당치 않고 단지 사료가치(飼料價値)가 떨어지는 타사료(他飼料)와 혼합(混合)하여 Silage를 제조(製造) 이용(利用)하므로서 타사료(他飼料)의 기호성(嗜好性)을 향상(向上)시켜 사료가치(飼料價値)를 증진(增進)시키고 아울러 Vitamin을 공급(供給)할 수 있는 방향(方向)으로 Silage를 제조(製造) 이용(利用)함이 적당할 것으로 사료(思料)된다.

• 한국윤활학회:학술대회논문집
• /
• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
• /
• pp.139-140
• /
• 2002

This paper discusses the effect of plating condition on the mechanical property of electroplated Cu film. Current density, the amount of the organic additives was found to affect the residual stress of electroplated copper film. The result show that, in the case of residual stress, the copper film deposited at higher additive result in lower residual stress and plating current by $15mA/cm^2$ induced a better result than any other ones.

• 한국세라믹학회지
• /
• 제49권5호
• /
• pp.423-426
• /
• 2012

$Al_2O_3$/NiO powder was obtained through hydrolysis-condensation reactions and thermal treatments. An organic additive, triblock copolymer surfactant P123, was added to the starting materials to control the surface area and morphology. The synthesized powder was characterized by X-ray diffractometry (XRD), field-emission scanning electron microscopy (FE-SEM) and a Brunner-Emmett-Teller surface analysis (BET). The heterogeneous catalytic activity of this powder was applied to an epoxidation reaction of styrene and was monitored using a gas chromatograph with mass spectrophotometry (GC/MS).

• International Journal of Concrete Structures and Materials
• /
• 제3권2호
• /
• pp.97-101
• /
• 2009

It has been known that acid-resistant concretes on the liquid glass basis have high porosity (up to 18${\sim}$20%), low strength and insufficient water resistance. Therefore they can not be used as materials for load-bearing structural elements. Significant increasing of silicate matrix strength and density was carried out by incorporation of special liquid organic alkali-soluble silicate additives, which block of superficial pores and reduces concrete shrinkage deformation. It was demonstrated that introduction of tetrafurfuryloxisilane additive sharply increases strength, durability and shock resistance of silicate polymer concrete in aggressive media. This effect is attributable to hardening of contacts between silicate binder gel globes and modification of alkaline component owing to "inoculation" of the furan radical. The optimal concrete composition with the increased strength, chemical resistance in the aggressive environments, density and crack resistance was obtained.

• 펄프종이기술
• /
• 제40권2호
• /
• pp.1-7
• /
• 2008

The trend of using more hardwood and recycled fibers, and closing more tightly of the paper mill white water system has resulted in build-up of fines as well as organic and inorganic contaminants in the white water. This changes in papermaking wet end requires developing chemical additive system that provides good fiber retention and drainage in closed white water system. In this study the effect of charge densities and chemical characteristics of microparticle systems consisted of cationic guar gums and anionic colloidal silica sols on drainage and retention have been examined. Results showed that higher charge density of cationic guar gum and anionic colloidal silica sol gave better retention and drainage. Particularly highly structured silica gave greater retention efficiency.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
• /
• pp.392.1-392.1
• /
• 2014

Isoindigo based small molecules have attracted much attention in the field of optoelectronic devices due to their broad absorbance and high charge carrier mobilitiies. Herein, we investigate the field effect transistor characteristics of a series of isoindigo based donor-acceptor-donor (D-A-D) small molecules containing a variable number of thiophene moieties (named IDT, ID2T, and ID3T) which form pi-bridges between the D and A moieites and a different donor moiety (IDED). In order to improve the carrier mobility, 1-chloronaphthalene (CN) and 1,8-diiodooctane (DIO) as solvent additives were used. The film morphology, crystallinity and optical properties of the materials processed with various concentrations of solvent additives were investigated through atomic force microscopy (AFM), X-ray diffraction (XRD) and UV-vis absorption spectroscopy.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
• /
• pp.655-657
• /
• 2002

The carbon nanotube emitters for field emission displays were fabricated by screen printing techniques. The pastes for screen printing are composed of organic binders, carbon nanotubes, and some additive materials. Then the pastes were printed on Cr-coated/Ag-printed soda-lime glass substrates. From the I-V characteristics, the turn-on field of SWNT was lower than that of MWNT. The decrease in the mesh size of screen masks resulted in decreasing the turn-on field and increasing the electron emission current. When the carbon nanotubes were mixed with glass frit, glass frit appeared to contribute to the vertically aligning of carbon nanotubes on glass.

• 한국염색가공학회지
• /
• 제20권4호
• /
• pp.1-7
• /
• 2008

Methacryloxypropyl trimethoxysilane (MAPTMS), a hybrid organic-inorganic monomer, was photografted onto PET fabric using benzophenone (BP) as a photoinitiator. It was found that a UV energy of 43.2J/$cm^2$ was required to optimally photograft the MAPTMS onto PET fabrics which was applied with an aqueous formulation of 10% MAPTMS, 20% BP and 0.5% N-Methyldiethanol amine (MDEA). The MDEA additive was efficient in reducing atmospheric oxygen inhibition of polymer radicals which eliminated compulsory nitrogen inerting. The surface grafting of PET fabrics was verified by fourier transform infrared spectroscopy (FT-IR) and scanning electron spectroscopy (SEM). The grafted PET fabrics with the hybrid monomer showed higher thermal stability due to the introduced silane component in the monomer as ascertained by higher char content at 800$^{\circ}C$, which increased to 14.5% for the 15.8% grafting compared to 8.2% for the untreated.