자동차 도료용 수용성 베이스 코트에 관한 연구

조을룡 한국기술교육대학교 2006 論文集 Vol.13 No.1

The water-born polyurethane/acrylic emulsion with core-shell morpology was used to develop water-born base coat for automotive coating. Compared to solvent based base coat, water-born base coat showed good water resistance and rust resistance, excellent appearance, and good workability at spray coating. The increase of polyurethane content in hybridized emulsion yielded improvement of adhesion, chip resistance, and film flexibility. The hardness of film with mole ratio of isocyanate group to hydroxy group increased with increasing isocyanate group. In the rheological measurement, unlike solvent based coating, water-born coating resulted in rapid rise of viscosity with increasing shear rate. The range of 3 to 6 of thixotropy index(TI) with use of thickener showed good storage stability and appearance, excellent orientation of color components.

수용성 도료용 조색제의 배합과 물성에 관한 연구

조을룡 한국기술교육대학교 2006 論文集 Vol.12 No.1

Tint pastes for water-based coatings were formulated and the properties were investigated as water-based coatings is being important due to environmental problems of solvent-based coatings. In the rheological behavior, viscosity of intermediate varies with respect to increased addition of wetting dispersant. The largest viscosity restitution occured at 8% of wetting dispersant when shear stress was removed, and anionic wetting dispersant yielded excellent restitution of viscosity at removal of shear stress. In terms of rheological behavior with pH, we could get the most stable dispersion at pH 8.5. Rheological behavior regarding to amount of dispersing resin showed the most stable pigmented dispersion at 6wt% of it. Particle size of pigment also affected jetness by variation of workability owing to differences of surface area.

폴리아크릴산계 중합체의 감수효과에 대한 연구

조을룡 한국기술교육대학교 2004 論文集 Vol.10 No.2

Acryl monomers such as acrylic acid(AA), methylmethacrylate(MMA), and ethyl acrylate(EA) were polymerized to use as water reducing agent for cement mortar. Acrylic acid was employed to show good final physical properties with polyoxyethylene aklyphenyl ether(Poly-E) and 2-acrylamido-2-methyl-1-propanesulfonic acid(AMPS). All the polymerizations were carried out in water-based solution to obtain environmentally freindly system. The viscosities of the synthesized solutions for the research have less than 800 cps. Especially, copolymer of AA, MMA, AMPS, and Poly-E resulted in high water retention, low bleeding, good dimensional stability, excellent resistance to freeze-thawing, and high compression strength due to hydrogen bonding of amide group of AMPS and ethylene oxide group of Poly-E.

Sol-gel based TiO2 paste applied in screen-printed dye-sensitized solar cells and modules

Mateja Hocˇevar,Ursˇa Opara Krasˇovec,Matevzˇ Bokalic,Marko Topic,Welmoed Veurman,Henning Brandt,Andreas Hinsch 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.5

A simple manufacturing process based on screen-printing is crucial for a successful commercialization of dye-sensitized solar cells (DSSCs). We developed the sol–gel based TiO2 paste in such a way that solely a single step deposition is sufficient to realize a sponge-like structure of the layer assuring its high activity in DSSCs. For the first time the sol–gel based TiO2 paste was screen printed and tested in DSSC masterplates and PV mini-modules. Electroluminescence imaging of the mini-module proved layer homogeneity and no manufacturing defects. The conversion efficiency of the PV mini-module with the active area of 75 cm2 reaches 5.7% at STC.

Evaluation of MgCo2O4 nanoparticles as a gas sensor for the detection of acetone in the diabetic and non-diabetic range

J. P. Morán-Lázaro,F. López-Urías,E. Muñoz-Sandoval,M. Courel-Piedrahita,A. Carreon-Alvarez,V. M. Rodríguez-Betancourtt,I. Zamudio-Torres,E. S. Guillén-López,A. Palafox-Corona 대한금속·재료학회 2023 ELECTRONIC MATERIALS LETTERS Vol.19 No.1

The acetone contained in human breath is of great interest for the health sector as it is a marker that allows to diagnoseand control diabetes in a non-invasive way. However, its concentration is extremely low. Therefore, high-performanceacetone sensors are still a challenge. With this in mind, MgCo 2 O 4 nanoparticles were synthesized using a microwaveassistedcolloidal route with subsequent calcination. Structural and morphological characterizations were done through varioustechniques. The MgCo 2 O 4 sensor was fabricated with the sample calcined at 500 °C. The sensing results showed that thesensor could detect acetone vapors ranging from 0.5 to 50 ppm at an optimum operating temperature of 250 °C with a highresponse, repeatability, stability, and selectivity. These sensing characteristics revealed that MgCo 2 O 4 could be used as a newsensor material to detect acetone in exhaled human breath.

Ab-initio Study of the Structural, Electronic, Elastic and Vibrational Properties of the Intermetallic Pd3V and Pt3V Alloys in the L12 Phase

N. Arlkan,A.Iyigör,A. Candan,M. Özduran,A. Karakoç,S . U ur4,G. Ugur4,A. Bouhemadou,S. Bin-Omran,N. Guechi 대한금속·재료학회 2014 METALS AND MATERIALS International Vol.20 No.4

Pseudopotential plane-wave method based on density functional theory within the generalized gradientapproximation for the exchange-correlation potential has been applied to study the structural, electronic, elasticand vibrational properties of the binary intermetallic Pd3V and Pt3V in the L12 phase. The optimized latticeconstant, bulk modulus and its pressure derivative, independent single-crystal elastic constants and elasticwave velocities in three different directions are evaluated and compared with the available experimental andtheoretical data. The polycrystalline elastic parameters, hardness coefficient, elastic anisotropy, Debye temperatureare estimated. The electronic band structure, electronic total and partial densities of states, and totalmagnetic moment of the Pd3V and Pt3V alloys are computed and analyzed in comparison with the existingtheoretical and experimental findings. Phonon-dispersion curves and their corresponding total and projecteddensities of states were obtained for the first time using a linear-response in the framework of the densityfunctional perturbation theory.

Polyphenol Bioaccessibility and Antioxidant Activity of Pomegranate (Punica granatum) Peel Supplementation in Diet-Induced Obese Rats

Anael Mellado-Negrete,Gloria Itzel Peña-Vázquez,Vania Urías-Orona,Ana Laura de la Garza 한국식품영양과학회 2023 Journal of medicinal food Vol.26 No.8

Fruit by-products are a source of biocompounds with antioxidant properties and potential role in the obesitytreatment. This study aimed to assess the effect of pomegranate (Punica granatum) peel (PP) supplementation on the totalantioxidant capacity (TAC) in diet-induced obese rats. Thus, an in vitro gastrointestinal digestion was performed to evaluatethe total phenolic content (TPC) and the antioxidant capacity of PP. Moreover, 15 male Wistar rats were randomized into threegroups: control diet (CTL; 3.35 kcal/g), cafeteria (CAF) diet (3.72 kcal/g), and CAF diet supplemented with PP (CAF + PP;200 mg/kg body weight; 3.72 kcal/g). Serum TAC was analyzed by ferric reducing antioxidant power and 2,2-Diphenil-1-picrylhydrazil assay. TPC in PP accounted for 8.82 – 0.14 mg GAE/g in undigested samples. However, an in vitro digestionprocess was decreased by 94% the bioaccessibility of PP phenolic compounds in the intestinal phase, while PP supplementationincreased serum TAC in diet-induced obese rats. Therefore, although PP phenolic compounds diminished after anin vitro digestion process, antioxidant effect was found in obese rats supplemented with PP.

Optical and electrical modelling and characterization of dye-sensitized solar cells

Marko Topič,Andrej Cˇ ampa,Miha Filipic,Marko Berginc,Urša Opara Krašovec,Franc Smole 한국물리학회 2010 Current Applied Physics Vol.10 No.3

A route of optical and electrical modeling of dye-sensitized solar cells (DSSCs) has been developed and validated within a set of test structures. The optical model is based on one-dimensional semi-coherent optical simulator SunShine, in which nanoporous active layer was successfully modelled as effective medium layer with effective scattering of light at its front and back surface interface using effective roughness. The electrical model is based on a pseudo-homogeneous active layer using drift–diffusion transport equations for free electron and ion transport. In both models, input parameters have been extracted from measured performance of test devices and main optical and electrical losses have been quantitatively identified for ionic liquid based DSSC structures, having 7 or 14 lm thick active layer.

범죄구성의 논리에 관하여

Urs Kindhä,user,Bonn,하태영 옮김 대검찰청 2013 형사법의 신동향 Vol.0 No.40

본 번역문은 범죄구성에 관한 독일의 최신 자료로서 이 분야 연구에 많은 도움을 줄 것으로 생각한다. 특히 발표자가 지적한 바와 같이 “범죄체계론은 동시에 형사판결문의 체계적인 구성을 위한 기본적인 틀을 제공하여야 한다”는 점에서 판결문 작성의 논리적 구성에도 매우 설득력 있는 자료가 될 것이다. 독일 본(Bonn) 대학교 법과대학 킨드호이저 교수(Prof. Kindhäuser)는 이 논문에서 의도적 행위개념(意圖的 行爲槪念, intentionaler Handlungsbegriff)과 회피가능성(回避可能性, Vermeidbarkeit)을 범죄구성론에서 중심에 두고 설명하고 있다. 그는 규범적-의사소통적 범죄행위모델(規範的-意思疏通的 犯罪行爲體系圖, normativ-kommunikatives Straftatmodell)을 통한 범죄체계론의 재구성을 강조하고 있다. 킨드호이즈 교수에 따르면 “규범에 따라 행동을 하지 않은 행위자는 비난을 받아야 한다. 비록 행위자가 어떤 상황에 처해 있었더라도 마찬가지이다. 여기서 중요한 역할을 하는 인간의 행위(行爲, Handeln)는 오로지 의도한 행위(意圖한 行爲, intentionales Handeln)이다. 시민들은 규범을 준수하기 위해 구성요건이 실현되는 것을 어떤 의도를 갖고 회피(die zielgerichtete Vermeidung der Tatbestandsverwirklichung um der Normbefolgung)해야 한다. 여기서 행위자는 구성요건을 실현하는 행태를 스스로 회피하기 위하여 필요한 행위능력과 동기부여능력(die nötige Handlungs- und Motivationsfähigkeit)을 가져야 한다. 이러한 두 가지 문제에 대해 사법부가 비난을 가할 수 있다면, 행위자(行爲者, Täter)는 형법적으로 책임을 져야 한다”고 설명한다. 회피가능성이론이 형사체계의의 전반을 관통하고 았어 매우 흥미로운 주장이라고 본다.

Effect of OH^- Concentration on the Mechanical and Microstructural Properties of Microarc Oxidatoin Coating Produced on Al7075 Alloy

Ur Rehman, Zeeshan,Lee, Dong-Gun,Koo, Bon Heun Materials Research Society of Korea 2015 한국재료학회지 Vol.25 No.10

In this work, ceramic coatings were prepared on Al7075 aluminum alloy using microarc oxidation (MAO) process in a silicate-fluoride based electrolyte solution. The effect of $OH^-$ concentration, by adding NaOH to the solution on the microstructural and mechanical properties of the coating was investigated. Surface morphology and cross sectional view of the coating was analyzed using SEM while XRD was used to examine the phase compositions of the coatings. From XRD ${\alpha}-Al_2O_3$ phase was found to be increased by adding NaOH to the electrolyte. Thereby, the hardness and the wear properties of the MAO coatings were found to be superior to those of the coatings prepared without NaOH addition or with amount maximum than 2 g/l NaOH. Moreover, the morphology of the coatings was transformed form nodule-based cluster to crater based structure with the addition of NaOH to the MAO electrolyte solution.