In the present work, we synthesize nano-sized ZnO, SnO2, and TiO2 powders by hydrothermal reaction using metal chlorides. We also examine the energy-storage characteristics of the resulting materials to evaluate the potential application of these powders to dye-sensitized solar cells. The control of processing parameters such as pressure, temperature, and the concentration of aqueous solution results in the formation of a variety of powder morphologies with different sizes. Nano-rod, nano-flower, and spherical powders are easily formed with the present method. Heat treatment after the hydrothermal reaction usually increases the size of the powder. At temperatures above 1000oC, a complete collapse of the shape occurs. With regard to the capacity of DSSC materials, the hydrothermally synthesized TiO2 results in the highest current density of 9.1 mA/cm² among the examined oxides. This is attributed to the fine particle size and morphology with large specific surface area.

Using a high pressure homonizer, we report on the electrochemical performance of Li4Ti5O12(LTO) particles manufactured as anode active material for lithium ion battery. High-pressure synthesis processing is performed under conditions in which the mole fraction of Li/Ti is 0.9, the synthesis pressure is 2,000 bar and the numbers of passings-through are 5, 7 and 10. The observed X-ray diffraction patterns show that pure LTO is manufactured when the number of passings-through is 10. It is found from scanning electron microscopy analysis that the average size of synthesized particles decreases as the number of passings-through increases. LiCoO2-based active cathode materials are used to fabricate several coin half/full cells and their battery characteristics such as lifetime, rate capability and charge transfer resistance are then estimated, revealing quite good electrochemical performance of the LTO particles as an effective anode active material for lithium secondary batteries.

전자 주게-전자 받게 (D-A) 구조를 가지는 퀴녹살린 유도체들을 산 촉매하 탈수 반응과 Suzuki coupling 반응을 이용하여 합성하였다. 퀴녹살린을 중심으로 dimethylaminobenzene (DMAB)과 triphenylamine이 수평방향과 수직방향에 각각 위치한 QxN2TPA, 그리고 동일한 구조에 DMAB와 methoxy substituted triphenylamine이 조합된 QxN2TPAOME를 합성하였다. UV-visible 분광법 및 순환 전압 전류법을 이용하여, 합성된 유기 단분자들의 광학 및 전기화학적 특성 분석을 실시하였다. QxN2TPA, QxN2TPAOME의 최대 흡수 파장은 THF 용액에서 각각 308, 313 nm를 나타내었으며, HOMO 및 LUMO 에너지 준위는 각각 QxN2TPA(-5.12, -2.98 eV), QxN2TPAOME(-5.01, -2.98 eV)를 나타내었다. 또한, 합성된 퀴녹살린 유도체들을 다양한 용매에 대하여 우수한 용매 의존 발색 효과를 나타내었는데, 이는 분자 내 전하 전달 과정을 통하여 생성된 큰 극성을 지니는 여기상태의 분자 에너지가 용매의 극성이 증가할수록 안정화되는 전자 주게 및 전자 받게 구조를 갖는 공액 물질의 특성에 기인한다.

Synthetic wood has been widely used in place of wood such as the building exterior materials and/or the floor plate of moving path. However, it has many disadvantages such as relatively low strength, low durability, and heavy weight, etc. In this study, the synthetic wood deck combined with an aluminum profile was suggested to overcome these disadvantages. The flexural strength of the aluminum-synthetic wood deck was obtained through the theoretical equations under three-point bending conditions. In addition, the finite element analyses were also conducted to evaluate the flexural strength of the aluminum-synthetic wood deck.

아연(zinc) 분말은 철의 부식을 막아주는 희생양극의 기능으로 자동차, 선박 및 철구조물의 부식을 방지하 는데 널리 사용되고 있다. 그러나 아연 분말은 높은 비중 때문에 수지나 용매 내에서 분산성이 저하되고 빠르게 침전이 일어나는 단점을 가진다. 본 연구에서는 실리카(SiOx)를 미세 아연분말의 표면에 코팅함으로써 아연분말의 물성 및 기능을 개선하고자 하였다. 아연분말의 실리카 표면코팅은 졸-겔법을 사용하였고 SEM/EDS의 표면 및 성분분석과 TEM 단면분석을 통하여 불순물이 잔존하지 않는 실리카 코팅이 성공적으로 형성됨과 그 코팅의 두께를 확인 할 수 있었다. 한편 코팅공정의 반복회수와 평균입도 변화와의 관계를 측정하여 2회까지의 반복코팅이 분산안정성을 유지하는데 효과적임을 확인하였다. 이 밖에 실리카 코팅 아연분말의 진비중(true density) 측정을 통해 코팅 공정에 의해 비중이 20% 이상 감소함을 확인하였고 제타포텐셜 측정으로 실리카 코팅에 의해 아연분말의 분산안정성이 4배까지 증가함을 확인하였다. 마지막으로 질산수용액 담지를 통해 실리카 코팅 아연분말의 내산성 향상 또한 확인하였다. 따라서 본 연구에서 제조된 실리카 코팅 아연분말은 방청 안료의 원료로 적합할 것으로 기대된다.

픽셀 아트는 낮은 해상도와 제한된 색 팔레트를 가지고 영상을 표현한다. 픽셀 아트는 낮은 연 산 성능과 적은 저장 공간을 가지는 초기 컴퓨터 게임에서 주로 사용되었다. 현대에 이르러, 픽셀 아트는 예술이나 퍼즐, 게임과 같은 다양한 분야에서 찾아볼 수 있게 되었다. 본 논문에서는 게임 캐릭터 영상을 입력으로 받는 픽셀 아트 생성 모델을 제안한다. 기존 방법 과는 달리, 합성곱 신경망(CNN:Convolutional-Neural Network)를 픽셀 아트 생성 목적에 맞게 변형하여 이를 이용하는 방법을 제시한다. 기존의 합성곱 연산 후에 upsampling 과정을 추가하여 픽셀 아트가 생성될 수 있도록 하였다. 네트워크는 ground truth와 생성된 픽셀 아트와의 평균 오차 제곱(MSE:Mean Squared Error)을 최소화해나가며 학습을 수행한다. Ground truth는 실제 아티스트가 생성하도록 하였고, 이미지 회전과 반전 기법을 이용하여 augumentation을 수행하였다. 생성된 데이터 집합은 학습, 검증, 시험 데이터로 나누었다. 이러한 데이터 집합을 기반으로 감독 학습을 실시하여 픽셀 아트 생성 네트워크를 학습하였다. 학습 모델의 학습 과정과 학습 정확도를 제시하고, 시험 데이터 뿐만 아니라 다양한 영상에 대한 픽셀 아트 결과도 함께 제시한다.

Graphene is an interesting material because it has remarkable properties, such as high intrinsic carrier mobility, good thermal conductivity, large specific surface area, high transparency, and high Young’s modulus values. It is produced by mechanical and chemical exfoliation, chemical vapor deposition (CVD), and epitaxial growth. In particular, large-area and uniform single- and few-layer growth of graphene is possible using transition metals via a thermal CVD process. In this study, we utilize polystyrene and boron oxide, which are a carbon precursor and a doping source, respectively, for synthesis of pristine graphene and boron doped graphene. We confirm the graphene grown by the polystyrene and the boron oxide by the optical microscope and the Raman spectra. Raman spectra of boron doped graphene is shifted to the right compared with pristine graphene and the crystal quality of boron doped graphene is recovered when the synthesis time is 15 min. Sheet resistance decreases from approximately 2000 Ω/sq to 300Ω/sq with an increasing synthesis time for the boron doped graphene.

Hydrothermal synthesis of highly crystalline TiO2 nanorods is a well-developed technique and the nanorods have been widely used as the template for growth of various core-shell nanorod structures. Magneli/CdS core-shell nanorod structures are fabricated for the photoelectrochemical cell (PEC) electrode to achieve enhanced carrier transport along the metallic magneli phase nanorod template. However, the long and thin TiO2 nanorods may form a high resistance path to the electrons transferred from the CdS layer. TiO2 nanorods synthesized are reduced to magneli phases, TixO2x-1, by heat treatment in a hydrogen environment. Two types of magneli phase nanorods of Ti4O7 and Ti3O5 are synthesized. Structural morphology and X-ray diffraction analyses are carried out. CdS nano-films are deposited on the magneli nanorods for the main light absorption layer to form a photoanode, and the PEC performance is measured under simulated sunlight irradiation and compared with the conventional TiO2/CdS core-shell nanorod electrode. A higher photocurrent is observed from the stand-alone Ti3O5/CdS coreshell nanorod structure in which the nanorods are grown on both sides of the seed layer.

Purpose: This study was aimed to provide in-depth understanding of male nurses’ work adaptation experience and suggest future directions for nursing interventions for them by synthesizing individual qualitative findings. Methods: Qualitative meta-synthesis method suggested by Sandelowski and Barroso was utilized. A total of 6 qualitative studies’ findings were synthesized to describe male nurses’ experience of work adaptation in clinical settings. Results: The major task regarding male nurses’ work adaptation was ‘planting himself in the workplace.’ Its contextual and related factors to the task include: extraordinary choice for men, female-centered hierarchical work culture, gender difference vs. interindividual difference, stereotyped view on ‘male’ nurses, strengthening work identity of nursing profession, and dim future even after many years of experience. Conclusion: The findings illuminated the necessity of orchestrated efforts from both female and male nurses to form work environments overcoming gender bias and promoting adaptation of male nurses in clinical settings.

New three emitting compounds, AK-1, AK-2 and AK-3 including diazocine moiety were synthesized through Suzuki-coupling reaction. Physical properties such as optical, electroluminescent properties were investigated. UV-visible spectrum of AK-1, AK-2 and AK-3 in film state showed maximum 392, 393 and 401 nm. PL spectrum of AK-1, AK-2 and AK-3 showed maximum emission wavelength of 472, 473 and 435 nm. Three compounds were used as EML in OLED device: ITO/2-TNATA (60 nm)/NPB (15 nm)/EML (35 nm)/Alq3 (20 nm)/LiF (1 nm)/Al (200 nm). AK-3 OLED device showed C.I.E value of (0.18, 0.26) and luminance efficiency of 0.51 cd/A at 10 mA/cm2. New derivatives including diazocine moiety were introduced as OLED emitting material and the EL efficiency was increased by the proper combination of core and side group.

4-methyl-7-(10-(pyren-1-yl)anthracen-9-yl)-2H-chromen-2-one (PAC), 7,7’-(anthracene-9,10-diyl)bis(4- methyl-2H-chromen-2-one) (CAC), 7-Anthracen-9-yl-4-methyl-chromen-2-one(AC), and 7-(naphthalen-1-yl)-2Hchromen-2-one (NC) were synthesized through Suzuki aryl-aryl coupling reaction. Optical and electroluminescence (EL) properties were evaluated by UV-visible absorption, photoluminescence (PL) spectra, and EL devices. Synthesized compounds were used as an emitting layer (EML) in non-doped device with the following structures: ITO/2-TNATA (60 nm)/NPB (15 nm)/synthesized compounds (35 nm)/Alq3 (20 nm)/LiF (1 nm)/Al (200 nm). Non-doped devices showed luminance efficiency (L.E.) of 1.38, 1.03, 1.12, and 0.39 cd/A at a current density of 10 mA/cm2.

Two new synergists are proposed for pigment dispersion in pigment ink. Benzoic acid was applied to Pigment Yellow 74 (PY-74) and Pigment Yellow 150 (PY-150) as a hydrophilic functional group to synthesize (E)-4-(((3-(2-(2-methoxy-4-nitrophenyl)hydrazono)-4-oxopent-1-en-2-yl)(2-methoxyph enyl)am-ino)methyl)benzoic acid (PY-74BA) and (E)-4-((2,4,6-trioxo-5-((2,4,6-trioxohexahydropyrimidin-5-yl)di-azenyl)tetrahydropyrimidin-1(2H)-yl)methyl)ben zoic acid (PY-150BA). Whereas pigment showed extremely low solubility in water and organic solvents like DMSO, DMF and methanol, two synergists were found to have higher solubility than pigment. This result can be interpreted as reduction of particle aggregation by increased polarity. Two synergists applied to pigment ink are expected to improve dispersion property and storage stability of ink.

Three new compounds are synthesized as color filter dyes by substituting a pyridine group into 1,4-position, 1,5-position, and 1,8-position of anthraquinone core moiety. Changes in physical properties of the synthesized compounds according to the substitution position are systematically investigated in terms of optical properties and thermal properties. The extinction coefficient value (ε) of the synthesized materials is extremely high and is above 4.22 in a log scale, and Td is above 300°C with high thermal stability.

Two emitting compounds, 9,10-bis-[1,1;3,1]terphenyl-5-yl-1,5-di-o-tolyl- anthracene [TP-DTA-TP] and 9,10-bis-phenyl[1,1;3,1]triphenyl-5-yl-1,5-di-o- tolylanthracene[ TPB-DTA-TPB] based on newtwisted core moiety were synthesized through boration, Suzuki reaction, and Sandmeyer reactions. EL performance was improved by varying the chemical structure of the side group. Physical properties such as optical, electrochemical, and electroluminescent properties were investigated. Synthesized compounds were used as an EML in OLED device: ITO/2-TNATA (60 nm)/NPB (15 nm)/TP-DTA-TP or TPB-DTA-TPB (35 nm)/Alq3 (20 nm)/LiF (1 nm)/Al (200 nm). It was found that TPB-DTA-TPB showed higher luminance efficiency and better C.I.E. value than TP-DTA-TP device.

We present a high-performance polymeric membrane based on self-cross-linkable poly(glycidyl methacrylate-g-poly-(propylene glycol))-co-poly(oxyethylene methacrylate) (PGP-POEM) graft copolymer for CO2/N2 separation. The self-cross-linked membranes can be easily prepared under mild conditions without any additional cross-linking agents or catalyst. We investigated the gas separation performance of the membranes as a function of POEM content in the copolymer. The self-cross-linked PGP-POEM membranes showed an improvement in both permeance and selectivity with increasing POEM content up to 51.2 wt %. The best performance of the membrane was achieved by optimizing membrane thickness, showing a CO2 permeance of 500 GPU (1 GPU = 10-6 cm3 (STP)/(s cm2 cmHg)) and CO2/N2 selectivity of 22.4.

For facilitated olefin/paraffin separation, poly(ethylene-alt-maleic anhydride)-g-O-(2-aminopropyl)-O′-(2-methoxyethyl) polypropylene glycol (PEMA-g-PPG) is reported by facile, cheap and moderate-condition synthesis. PEMA-g-PPG provided effective polymer matrix for partially polarized silver nanoparticles (AgNPs) and 7,7,8,8-tetracyanoquinodimethane (TCNQ). AgNPs could facilitate olefin transport through π-complexation, while TCNQ activated surface of AgNPs for partial polarization as a strong electron acceptor. The FT-IR and TEM image supported improved interactions between PEMA-g-PPG and AgNPs. The best separation performance was obtained with 1:3 wt ratio of PEMA-g-PPG:AgNPs, showing 7.8 GPU for mixed gas permeance and 17.5 selectivity for propylene/propane.

Polymer electrolyte membrane fuel cells (PEMFCs) have attracted particular interest as alternative and enviromentally friendly energy source for both mobile and stationary application. The perfluorosulfonic acid membranes, such as Nafion® are most used PEMs because of their good chemical and electrochemical stability. However they have drawbacks such as high cost, low application temperature, insufficient durability. Sulfonated poly (arylene ether)s, poly (phenylene ether)s, poly (arylene ether ketone)s have beem developed. This work is an attempt to synthesize sulfonated poly (arylene ether)s contained phosphinate moiety which is pendant phenyl structure. Sulfonated poly (arylene ether)s membranes were prepared from DOPO-BPA, 4,4’-sulfonyl diphenol(SFDPS), 1,4-bis(4-fluoro benzoyl)benzene(1,4-FBB).

Current petrochemical product mainly comes from light olefin, such as ethylene and propylene. these olefins can be obtained as mixture form of olefin/paraffin, which is co-product of naphtha cracking process. However, the mixture of light olefin and paraffin is considerably difficult to separate because they have similar physicochemical properties such as density, boiling point, and molecular weight. Cryogenic distillation is currently utilized, but still suffered from high operating cost. Membrane separation with polyimide-based material is a promising alternative due to its lower energy cost and modular operation. Here, we synthesized composite membrane with metal-organic framework (MOF) based on polyimide exhibiting high permeability and selectivity in propylene/propane separation, as well as simple preparation and high stability.

The anion exchange membrane (AEM) has a structure having a group of positively charged ions inside, and selectively permeates the anion of the electrolyte. In addition, excellent ion conductivity and chemical durability, and highly reliable electrochemical performance are required. However, commercially available AEMs have a hydrocarbon-based backbone. It is difficult to make the thin film because of low solubility. As a result, it has low ionic conductivity and high area resistivity and shows limitations in electrochemical applications. In this study, a perfluorinated ionomer-based anion exchange membrane with excellent chemical stability is prepared and shows enhanced anion conductivity in electrochemical applications.