• 대한건축학회연합논문집
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• 제21권3호
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• pp.87-92
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• 2019

To relieve noise between floors in Korea, recent domestic and overseas studies have been developing materials that have the properties of ceramic, which is an inorganic compound, and polymer, which is an organic compound, to introduce a new function to polymer. This study conducted a bending strength experiment between re-bar and new composite concrete mixing POSS (Polyhedral Oligomeric Silses-quioxanes) nano complex on the inside of concrete, and by assembling the inside of each concrete with 3 and 4 main re-bars as an experiment to supplement various problems that occur by the expression of this strength and the distribution of the reinforcement. The number of the main re-bars. and the direction of laying the concrete were applied as the principal variables of the experiment. Upon experiment, there were no differences in the bond strength based on the location of the main re-bar, and a 2 % increase in the bond strength was shown in the specimen laid in the same direction as the main re-bar in comparison to that of the specimen laid in a different direction from the main re-bar. The experiment results displayed that the composite concrete had uniform performance based on the rapid reaction speed of POSS nano complex.

• Journal of Animal Science and Technology
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• 제64권5호
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• pp.885-896
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• 2022

This experiment was conducted to investigate the effects of three different copper (Cu) sources (one inorganic and two organics) and levels (0, 50, and 100 mg/kg) on the growth performance, Cu digestibility, fecal mineral excretion, serum mineral concentration, jejunal morphology, and serum biochemical profile of growing pigs. A total of 42 male, growing pigs (31.08 ± 1.82 kg) were randomly assigned to seven treatments consisting of one negative control (0 mg/kg of added Cu level) and treatments with copper sulfate (CuSO4), Cu-amino acid complex (CuAA), and Cu-hydroxy-4-methylthio butanoate chelate complex (CuHMB) at 50 and 100 mg/kg each for 28 d. Pigs fed 50 or 100 mg/kg of Cu showed improved (p < 0.05) average daily gain and feed intake. Although Cu excretion decreased (p < 0.01) in pigs fed 100 mg/kg of organic Cu sources compared to those fed CuSO4, there was no difference between the Cu sources in pigs fed 50 mg/kg. However, the apparent total tract digestibility of Cu increased (p < 0.01) in pigs fed organic Cu sources compared with that in pigs fed CuSO4. The addition of CuHMB increased (p < 0.01) serum phosphorus and sulfur concentrations; however, there were no effects of source and level on jejunal morphology and serum biochemical profile. These results suggest that the inclusion (50 mg/kg) of organic Cu sources (CuAA and CuHMB) in the growing pig diet could be beneficial for growth performance and Cu availability and may reduce environmental pollution.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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• pp.499-502
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• 2004

Groundwater chemistry in a coastal region having complex contaminant sources was investigated. Water analysis data for 197 groundwater samples collected from the uniformly distributed sixty-six wells were used. Chemical analysis rand results indicate that groundwaters show wide concentration ranges in major inorganic ions, reflecting complex hydrochemical processes of pollutants. Due to the complexity of groundwater chemistry, Results illustrate that thirty five percent of the wells do not fit for drinking based on nitrate and chloride concentration in the study area. the samples were classified into four groups based on Cl and NO$_3$ concentrations and the processes controlling water chemistry were evaluated based on the reaction stoichiometry. The results explained the importance of mineral weathering, anthropogenic activities (nitrification and oxidation of organic matters), and Cl-salt inputs (seawater, deicer, NaCl, etc.) on groundwater chemistry. It was revealed that mineral dissolution is the major process controlling the water chemistry of the low Cl and NO$_3$ group (Group 1). Groundwaters high in NO$_3$ (Groups 2 and 4) are acidic in nature, and their chemistry is largely influenced by nitrification, oxidation of organic matters and mineral dissolution. In the case of chloride rich waters (Group 3), groundwater chemistry is highly influenced by mineral weathering and seawater intrusion associated with cation-exchange reactions.

• 진공이야기
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• 제2권2호
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• pp.4-11
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• 2015

본 글에서는 광전자 분광 및 역광전자 분광을 이용한 유기분자 시스템의 전자구조 연구에 대하여 기술하였다. 다양한 유기물간의 계면 연구가 급속도로 늘어나고 있으며, 폴리머, 거대 분자 등 기존의 in situ 분석 방법으로 실험이 어려운 물질까지도 연구의 필요성이 늘어나고 있다. Electrospray 증착 방법이 이러한 새로운 물질들의 계면 전자구조 연구를 가능하게 할 수 있음을 살펴보았으며, 다양한 새로운 분석 기법들의 출현을 기대해 본다. 몇 가지 예에서 살펴본 바와 같이 전자구조는 소자 구동 특성을 직접적으로 지배하는 핵심적인 물리량이며, 전자구조의 이해를 통해 전자소자의 구동 원리, 성능 최적화 및 소자 특성 열화의 원인을 파악할 수 있다. 현재, 유기물 소자 관련 기술의 성숙도는 전자구조 분석과 같은 기초 연구 결과 없이는 더 이상 발전할 수 없는 정도에 이르러, 관련 분석 기술에 대한 수요가 더욱 늘어날 것으로 전망된다.

• 공업화학
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• 제21권6호
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• pp.670-675
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• 2010

나노실리카볼 입자를 합성하고 표면에 비닐기를 부여하는 합성 연구를 통해 다양한 크기로 조절이 된 유-무기하이브리드 입자인 비닐-나노실리카볼이 합성되었다. 다양한 크기의 비닐-나노실리카볼 입자를 상업적으로 적용되고 있는 아크릴-멜라민 클리어코트에 후첨시키고 경화시켰을 때, 클리어코트의 광택도 증가 및 유지 특성에 대해 연구하였다. 실리카볼 입자가 250 nm 정도인 경우 Matting effect에 의한 광택도 감소가 관측되었으나 20~30 nm로 작아지면 광택도 유지 효과가 약 7%까지 증가하였다. 나노실리카볼 대신 상업용 친수 실리카 Aerosil 200 (Hydrophilic fumed silica, 평균입도 12 nm, Degussa)을 사용하여 비닐- fumed 실리카 화합물을 합성하여 클리어코트에 적용하면 광택도 유지 효과가 약 2% 정도만 증가하였다.

• 공업화학
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• 제9권1호
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• pp.135-140
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• 1998

제지공정 트러블을 일으키는 침착물과 제품의 품질을 저하시키는 종이내 불순물들의 성분을 기기분석하였다. 우선적으로 퓨리에변환 적외선분광기(FT-IR spectrometer)를 이용하여 이물질의 원형 그대로를 측정하여 예비정보를 얻은 뒤 열분해-가스크로마토그래피-질량분석기(Py-Gc/MS)를 이용해서 불순물들의 유기성분을 분석하였으며, $590^{\circ}C$에서 열분해시키고 난 ash는 에너지분산분광법(EDS)을 이용하여 무기성분을 분석하였다. 초지기 건조부에 침착된 성분은 지방산 에스테르 및 전분 등의 유기 이물질과 탈크, 크레이, 탄산칼슘 등의 무기 이물질로 이루어진 복합적인 피치형태로써 재사용 도공파지 성분에 의한 것이며, 심사이저 메터링로드에 끼인 침착물은 불안정한 alkyl keten dimer(AKD) 성분이 탄산칼슘과 상호작용하여 침착을 일으킨 것으로 분석되었다. 종이내 구멍 성분은 주원료로 사용되는 펄프에서 혼입된 것으로 판단되는 PE및 PP 성분과 초지공정에 사용된 주 부원료들간의 불안정한 상호작용에 의해 응집된 복합적인 피치성분으로 확인되었다. 작업상의 부주의로 완정공정에서 사용되는 hot melt 및 파렛트 받침대로 사용되는 가소제를 첨가하여 유연하게 만든 PVC 성분이 재사용 파지와 함께 혼입되어 종이내 얼룩 및 반점 등을 발생시키기도 하며, 초지기 용구로 사용되는 고분자 물질(와이어 또는 펠트)의 일부가 사고 등에 의해 공정중에 혼입되어 도공시 스트리크를 발생시킬 수도 있음을 알 수 있었다.

• 대한치과기공학회지
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• 제29권1호
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• pp.121-131
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• 2007

A preparation process's conditions of aqueous sol which contains anatase-type nano titania particles with photocatalyic properties was established by using Yoldas process, so called, DCS(Destabilization of Colloidal Solution) process in this study. And crystal size change and phase transformation of titania particles in aqueous titania sol depending on reaction conditions was investigated by a light scattering method and XRD analysis of frozen dried powders, respectively. This sol with photo catalytic nano titania particles was used to the following hydrophilic hybrid coating film's fabrication and its properties was evaluated. Subsequently, for coating film using the above mentioned aqueous titania sol, non-aqueous titania sol was prepared without any chemical additives and its time stability according to aging time was investigate. By using the above mentioned aqueous titania sol and non-aqueous sol, a complex oxide coating sol for metal and ceramic substrate and a organic-inorganic hybrid coating sol for polymer substrate was prepared and it's hydrophilicity depending on UV irradiation conditions was evaluated. As a conclusions, the following results were obtained. (1)Aqueous titania sol The average particle size of titania in formed aqueous titania sol was distributed between 20$\sim$90nm range depending on reaction conditions. And the crystal phase of titania powders obtained by frozen drying method was changed from amorphous state to anatase and subsequently transformed to rutile crystal phase and it is attributed to concentration gradient in aqueous sol. (2)Non-aqueous titania sol Non-aqueous titania sol was prepared using methanol as a solvent and a little distilled water for hydrolysis and nitric acid as a catalyst were used. The obtained non-aqueous titania sol was stable at room temperature for 20 days. Additionally, non-aqueous titania sol with addition of chealating reagent such as acethylaceton and ethylene glycol prolonged the stability of sol by six months. (3)Complex sol and hybrid sol with super hydrophilicity The above mentioned aqueous titania sol as a main photocataylic component and non-aqueous titania sol as a binder for coating process was used to prepare a complex sol used for metal, ceramic and wood material substrate and also to prepare the organic-inorganic hybrid sol for polymer substrate such as polycarbonate and polyethylene, in which process APMS(3-Aminopropyltrimethoxysilane), GPTS(3-Glycidoxypropyl-trimethoxysilane) as a hydrophilic silane compound and HEMA(2-Hydroxyethyl methacrylate) as a forming network in hybrid coating film were used. The hybrid coating film such as prepared through this process showed a superhydrophilicity below 1$10^{\circ}$ depending on processing conditions and a pencil's hardness over 6 H.

• Bulletin of the Korean Chemical Society
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• 제27권10호
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• pp.1587-1592
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• 2006

We report the preparation, structure and magnetic properties of a new pillared complex, copper(II) hydroxy-1,4-butanedisulfonate, $Cu_2(OH)_3(O_3SC_4H_8SO_3)_{1/2}$. The titled compound was obtained by anion exchange, using copper hydroxyl nitrate $(Cu_2(OH)_3NO_3)$ as the starting material. According to the XRD data, this compound exhibits a pillared layered structure with organic layers tilted between the copper hydroxide layers with a tilt angle of $21.8^{\circ}$. FTIR spectroscopy confirms total exchange of nitrate by the sulfonate and indicates that the sulfonate functions are linked to the copper(II) ions with each aliphatic chain bridging the adjacent hydroxide layers. According to the dc and ac magnetic measurements, the title compound is a metamagnet consisting of spin-canted antiferromagnetic layers, with a Neel temperature of 11.8 K.

• Bulletin of the Korean Chemical Society
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• 제35권1호
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• pp.76-82
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• 2014

1-Methylimidazole-2-thiol, as a kind of mercaptans, is a typical organic pollutant which has not been efficiently removed. In this study, titanium dioxide ($TiO_2$) photocatalyst based on magnetic multi-walled carbon nanotubes (MWCNTs) was synthesized via hydrothermal and sol-gel methods. The as-prepared photocatalyst was extensively characterized by X-ray diffraction (XRD), X-ray energy diffraction spectrum (EDS), transmission electron microscope (TEM), Fourier transform infrared (FT-IR) spectra, UV-Vis diffuse reflectance spectra (UV-vis DRS) and vibrating sample magnetometer (VSM). This photocatalyst of $TiO_2$/$Fe_3O_4$/MWCNTs was proved to exhibit high photocatalytic efficiency and the photodegradation rate could reach nearly 82.7% for the degradation of 1-methylimidazole-2-thiol under ultraviolet irradiation. In addition, the results demonstrated that inorganic ions had a negative impact on photodegradation of 1-methylimidazole-2-thiol to varying degrees. Moreover, pH had a great and complex effect on photocatalytic degradation of 1-methylimidazole-2-thiol under ultraviolet irradiation.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
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• pp.233-236
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• 2005

Sewage facilities are positively necessary for environment improvement such as rainwater removal, sewage disposal, preservation of the quality of water and health of the citizens in present-day. Meanwhile, a deterioration of the concrete sewer facilities is increasing rapidly due to the chemical and physical attack and especially biochemical attack that is to say biodeterioration. In this study, to prevent biochemical corrosion of the sewer concrete, surface of the concrete was spread with liquefied organic and inorganic complex antibiotics and then its engineering properties were experimentally investigated