In this study, Pitch-derived activated carbon (PAC) pellets were by steam activation for automotive carbon canisters. The crystal structure of PAC was analyzed using X-ray diffraction. The textural properties of PAC were studied by Brunauer– Emmett–Teller (BET), Horvath-Kawazoe (HK), and Non-Localized Density Functional Theory (NLDFT) equations with N2/ 77 K isotherm adsorption/ desorption curves. The butane adsorption capacity of the PAC pellets was analyzed according to the ASTM D5228 standard. With increasing steam activation time, the specific surface area and total pore volume of the PAC increased 650–1950 m2/ g and 0.27–1.02 cm3/ g, respectively. The mesopore ratio of PAC increased with increasing activation time and was observed up to 28.4% at 190 min. The butane adsorption capacity of the PAC increased and was observed to range from 10.86 to 51.55%. A close relationship between butane adsorption capacity and pore size (1.47–2.39 nm) was found. Finally, the butane activity of PAC was found to be 51.55% for the steam activated at 950 ℃ for 190 min; this butane activity is 24% better than that of the coconut-derived activated carbon (41.43%) with a similar specific surface area, indicating that pitch is a suitable material for the activated carbon of automotive carbon canisters.

The coatings based on carbon nanotubes (CNTs) are increasingly developed for their applications, among others, in medicine, in particular for implants in implantology, cardiology, and neurology. The present review paper aims at a detailed demonstration of different preparation methods for such coatings, their performance, and relationships between deposition parameters and microstructure and material, mechanical, physical, chemical, and biological properties. The thermal and electrostatic spraying, electrophoretic and electrocathodic deposition, and laser methods are presented. Characterization of microstructure of coatings, topography, morphology, adhesion of CNTs to a substrate, mechanical behavior, corrosion resistance, wettability, cytotoxicity, bioactivity, and antibacterial protection are reviewed for different deposition methods and parameters. The state-of-the-art in the field of carbon nanotubes shows a considerable number of research performed on CNTs coatings. The different forms of CNTs, deposition methods, parameters, and substrates were applied as process variables. The microstructures and surface homogeneity, chemical and phase compositions, mechanical properties at the micro- and nanoscale such as coating Young`s modulus and hardness, interface adhesion strength and delaminating force, open corrosion potential and corrosion current density, contact angle in wettability assessment, and bioactivity, cytotoxicity, and antibacterial efficiency among biological properties were determined. The summary of so far achievements, strengths and weaknesses, and important future research necessary for clarification of some weak points, development of non-toxic, mechanically and chemically resistant, bioactive, and antibacterial multicomponent coatings based on functionalized CNTs are proposed.

본 연구는 간호대학생의 사회정서역량과 전공만족도, 진로준비행동 간의 관계를 살펴보고, 진로 준비행동에 영향을 미치는 요인을 파악하기 위하여 시도되었다. 자료수집은 2023년 12월 5일부터 2024년 1월 3일까지 S시, C도와 K도에 위치한 대학의 간호대학생(2∼4학년) 197명을 대상으로 실시되었다. 수집 된 자료는 SPSS 29.0 프로그램을 이용하여 descriptive statistics, t-test, ANOVA(사후분석 Scheffe), Pearson’s correlation, Hierarchical multiple regression을 이용하였다. 연구 결과, 간호대학생의 사회정서 역량과 전공만족도, 진로준비행동은 서로 통계적으로 유의한 양의 상관관계를 보였다. 위계적 다중회귀분 석 결과, 진로준비행동에 영향을 미치는 요인으로는 학년, 진로 프로그램 참여, 사회정서역량과 전공만족도 가 있었으며, 진로준비행동에 대한 이들 변수의 설명력은 40.3%로 확인되었다. 본 연구 결과를 토대로, 학 년별 사회정서역량을 강화하기 위한 프로그램 개발 및 적용이 필요하며, 전공만족도를 높이기 위한 진로 교육프로그램이 필요하다.

본 연구는 한국 소재 대학교 석사과정에 재학 중인 우즈베키스탄 여성 3인의 유학 준비 과정과 초기 적응 과정을 질적으로 분석하였다. 연구는 2023년 8월부터 5개월 동안 5회 심층면담을 하였다. 연구결과 첫째, 비 자 발급은 어렵고 복잡하며, 남겨진 채무는 앞으로 갚아야 한다. 둘째, 숙소 구하기 어려움과 배달 음식으로 끼니를 해결한다. 셋째, 숙달치 않 은 한국어 실력으로 인한 학업의 어려움은 극복해야 한다. 넷째, 한국 문 화에 길들고 있지만 한국인들의 편견은 부담이다. 본 연구는 석사과정 유학생 3인이라는 한계를 지니지만, 앞으로 외국인 유학생들을 위한 정 책이나 제도 개선을 위한 자료로 활용될 수 있을 것이다. 대학원 유학생 다수를 대상으로 대학 생활의 변화를 탐색하여 유학생들이 한국 교육을 통한 성장의 발판을 마련할 수 있도록 후속 연구가 진행되기를 바란다.

Pepper cultivation requires a great amount of manual labor, especially for varieties needing support stakes to prevent them bending or breaking in heavy winds or rain. In Korea, it is recommended to secure support stakes and string lines carefully, so as to minimize the risk of damage caused by typhoons. The harvesting of peppers is a labor-intensive process with low rates of mechanization.The removal of stakes is particularly time-consuming during mechanical harvesting, and lodging is a major issue during cultivation and mechanical harvesting. Given increased mechanization during pepper harvesting, it is important to consider these issues when undertaking variety development and cultivation method improvements. Further research and development are required to improve cultivation practices and develop pepper varieties that are more resistant to lodging. Therefore, this study aimed to investigate the impact of different cultivation methods on pepper lodging, thus broadening our knowledge on the desirable architecture of pepper plants required for lodging tolerance.

Porous graphene oxide (P-GO) was successfully synthesized by using a simple glucose mediated hydrothermal method form prepared graphene oxide (GO). Then the P-GO was characterized by X-ray Powder Diffraction (XRD), Fourier-Transform Infrared (FITR), Raman, Brunauer–Emmett–Teller (BET), Field Emission Scanning Electron Microscopy (FESEM) and Transmission Electron Microscopy (TEM) analysis to determine the crystallinity, surface functionality, surface defect, surface area and porous nature of the material. For the comparative properties studies with P-GO, the synthesised GO was also characterised using the aforementioned analytical techniques. The formation of macroporous 2D sheet-like structure of P-GO with pore size diameters of 0.2–0.5 μm was confirmed by FESEM and TEM images. The surface area of P-GO was found to be 1272 m2/ g which is much higher compare to GO (i.e., 172 m2/ g) because of porous structure. P-GO was used for the adsorptive removal of F− ions from water using batch adsorption method. The highest adsorption occurs in the pH range of 5–7 with maximum adsorption capacity of 1272 mg/g. The experimental data revealed that the adsorption process obeys Langmuir monolayer isotherm model. The kinetic analysis revealed that the adsorption procedure is extremely rapid and mainly fit to the Pseudo-second-order (PSO) model. The effect of co-existing ions on fluoride adsorption capacity by P-GO decreases in the following order: PO4 3− > CO3 2− > SO4 2− > HCO3 − > NO3 − > Cl−. The mechanism of adsorption of fluoride onto the P-GO surface includes electrostatic interactions and hydrogen bonding.

The discharge of industrial oily wastewater and oil spill accidents has resulted in significant environmental pollution, creating an urgent need for the treatment of oily wastewater. Nanofiber membranes, known for their high stability, flux, and efficiency, are widely employed in oil–water separation. This study systematically compared the performance of polyacrylonitrile/ graphene oxide (PAN/GO) composite nanofiber membranes prepared through immersion and electrospinning methods for oily wastewater treatment. Experimental findings demonstrated that immersion-prepared membranes achieved high flux (772.9 ± 2.9 L·m−2·h−1, n-hexane/water mixture) and efficiency (98.8%) at a GO concentration of 1.0 g/mL. On the other hand, electrospinning-prepared membranes exhibited superior flux (1500.3 ± 4.4 L·m−2·h−1, n-hexane/water mixture) and efficiency (99.6%) at a higher GO concentration (1.5 g/mL). This membrane displayed excellent stability, maintaining their exceptional performance even after ten cycles of separation. This study compared the advantages and disadvantages of the two methods for preparation of PAN/GO composite nanofiber membrane, offering valuable guidance for practical applications.

본 연구의 목적은 항공서비스 전공 대학생의 전공선택동기를 내재적· 외재적 전공선택동기로 구분하여 전공선택동기가 전공만족도를 매개로 대학생활적응과 진로준비행동에 어떠한 영향을 미치는지를 알아보는데 있다. 이를 위해 충청지역 4년제 J대학의 항공서비스 전공 대학생 236명 을 대상으로 설문조사를 실시하였으며, 본 연구의 결과를 요약하면 다음 과 같다. 첫째, 내재적 전공선택동기는 대학생활적응 및 진로준비행동에 정(+)의 영향을 미치는 것으로 나타났다. 둘째, 외재적 전공선택동기는 전공만족도에 유의한 정(+)의 영향을 미치는 것으로 나타났다. 셋째, 전 공만족도는 대학생활적응과 진로준비행동에 유의한 정(+)의 효과가 있는 것으로 나타났다. 넷째, 매개효과 검증결과 내재적 전공선택동기는 전공 만족도를 매개로 한 간접효과는 없지만, 외재적 전공선택동기는 전공만 족도를 매개로한 간접효과가 있는 것으로 나타났다. 따라서 대학생의 성 공적인 대학생활적응을 위해서 학생들의 전공선택동기를 파악하는 것이 중요하며, 대학생활적응 및 진로준비행동을 향상시키기 위해서는 전공만 족도의 역할이 중요함을 확인할 수 있었다. 이러한 결과를 바탕으로 항 공서비스 전공 대학생의 건강한 대학생활적응을 돕고, 학생들의 진로상 담에 도움이 될 수 있는 기초자료를 제공하고자 한다.

본 연구에서는 역전기투석용 4차 암모늄이온을 음이온교환기로 갖는 폴리아크릴레이트계 광가교형 음이온교환막 을 개발하였다. 역전기투석은 청정 재생에너지 생산 시스템이지만 출력이 낮고 핵심 소재인 분리막의 가격이 비싸다는 단점 으로 인해 상용화에 제한이 있다. 이에, 지지체가 없는 광가교형 음이온교환소재를 제조하였으며 개발한 고분자의 주쇄는 우 수한 물성의 엔지니어링 플라스틱을 기반으로 제조하였다. 제조된 분리막은 우수한 물리적, 화학적, 전기화학적 특성을 보였 으며 상용 음이온교환막인 AMV와 비교하여 약 50% 낮은 분리막 저항을 보였다. 더욱이 CQAPPOA-35는 40 μm의 얇은 분 리막 두께에도 불구하고 상용막과 동등 수준의 선택도를 보이는 것을 확인할 수 있었다. CQAPPOA-35을 적용한 RED 스택 은 최대 2.327 W m-2 (flow rate : 100 mL min-1)의 출력 밀도를 보여 AMV가 도입된 것보다 15% 향상된 성능 특성을 보였 다. 개발된 CQAPPOA-35이 광경화를 통해 쉽고 저렴하게 제조할 수 있으며 RED 스택 특성도 매우 우수하다는 점을 고려할 때, 개발된 CQAPPOA-35은 RED용 음이온교환막으로 상용 활용을 위한 대안이 될 수 있을 것으로 기대된다.

본 실험에서는 α-Al2O3 지지체에 무전해도금을 이용하여 Pd-Ag-Cu 분리막을 제조하였다. Pd, Ag, Cu는 각각 무 전해도금을 통해 지지체 표면에 코팅하였고, 합금의 형성을 위해 무전해도금 중간에 H2, 500°C의 조건에서 18 h 동안 열처리 를 진행하였다. 이를 통해 제조된 Pd-Ag-Cu 분리막은 SEM을 통해 표면을 관찰하였으며, Pd 분리막의 두께는 7.82 μm, Pd-Ag-Cu 분리막의 두께는 3.54 μm로 측정되었다. EDS와 XRD 분석을 통해 Pd-Ag-Cu 합금이 Pd-78%, Ag-8.81%, Cu-13.19%의 조성으로 형성된 것을 확인하였다. 기체투과 실험은 H2 단일가스와 H2/N2 혼합가스에서 실험을 진행하였다. H2 단일가스에서 측정한 수소 분리막의 최대 H2 flux는 Pd 분리막의 경우 450°C, 4 bar에서 74.16 ml/cm2·min이고, Pd-Ag-Cu 분리막의 경우 450°C, 4 bar에서 113.64 ml/cm2·min인 것을 확인하였고, H2/N2 혼합가스에서 측정한 separation factor의 경우 450°C, 4 bar에서 각각 2437, 11032의 separation factor가 측정되었다.

분리막 기술은 해수담수화, 기체분리 등 산업용 분리 정제 공정을 비롯하여 우리 주변의 생활용품, 의료 및 헬스 케어 제품 등에서 쉽게 찾아볼 수 있다. 최근 지속가능한 친환경 분리막 제조 기술 또한 환경오염을 줄이기 위해 연구되고 있으며, 특히 polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), polybutylene succinate (PBS) 등 생분해성 소 재를 활용한 분리막 제조기술이 보고되어 왔다. 기존 분리막 소재와 마찬가지로 생분해성 고분자 소재들 또한 상분리 공정을 통해 다공성 분리막을 제조하는 연구가 이루어지고 있다. 본 총설을 통해 대표적인 생분해성 고분자인 PLA 기반의 상분리 공정을 활용한 분리막 제조 기술 개발 동향을 살펴보고 향후 연구 개발 및 적용 가능성에 대해 고찰해보고자 한다.

This study successfully prepared high-porosity aluminosilicate fibrous porous ceramics through vacuum suction filtration using aluminosilicate fiber as the primary raw material and glass powder as binder, with the appropriate incorporation of glass fiber. The effects of the composition of raw materials and sintering process on the structure and properties of the material were studied. The results show that when the content of glass powder reached 20 wt% and the samples were sintered at the temperature of 1,000 °C, strong bonds were formed between the binder phase and fibers, resulting in a compressive strength of 0.63 MPa. When the sintering temperatures were increased from 1,000 °C to 1,200, the open porosity of the samples decreased from 89.08 % to 82.38 %, while the linear shrinkage increased from 1.13 % to 10.17 %. Meanwhile, during the sintering process, a large amount of cristobalite and mullite were precipitated from the aluminosilicate fibers, which reduced the performance of the aluminosilicate fibers and hindered the comprehensive improvement in sample performance. Based on these conditions, after adding 30 wt% glass fiber and being sintered at 1,000 °C, the sample exhibited higher compressive strength (1.34 MPa), higher open porosity (89.13 %), and lower linear shrinkage (5.26 %). The aluminosilicate fibrous porous ceramic samples exhibited excellent permeability performance due to their high porosity and interconnected three-dimensional pore structures. When the samples were filtered at a flow rate of 150 mL/min, the measured pressure drop and permeability were 0.56 KPa and 0.77 × 10-6 m2 respectively.

본 연구는 중고령 임금근로 장애인의 직무만족도와 일상생활만족도 간 자기효능감의 매개효과와 노후준 비의 조절된 매개효과를 살펴보고자 시도되었다. 본 연구는 2021년의 장애인 고용패널 2차 웨이브 6차조 사 데이터를 사용하여 빈도분석 및 기술통계, 상관관계 분석, 위계적 회귀분석 등을 하였다. 연구대상은 만 45세 이상 중고령 임금근로 장애인 806명이다. 연구결과로는 첫째, 중고령 임금근로 장애인의 직무만 족도는 일상생활만족도에 정적(+)으로 영향을 미치고 있는 것으로 나타났다. 둘째, 자기효능감은 직무만족 도와 일상생활만족도와의 관계에서 부분 매개하는 것으로 나타났다. 셋째, 직무만족도와 일상생활만족도 의 간 자기효능감의 매개효과는 노후준비에 의해 조절되는 것으로 나타났다. 연구결과를 바탕으로 중고령 임금근로 장애인의 직무만족도와 자기효능감을 증진하고 일상생활만족도 향상과 노후준비를 위한 사회복 지 정책과 실천적 방안을 마련하기 위한 시사점을 논의하였다.

In this study, we investigate the impact of Isophorone diisocyanate functionalized graphene oxide (IPDI-GO) on the flame retardancy of rigid polyurethane foam (RPUF). IPDI-GO was synthesized and introduced into the RPUF matrix. The flame retardancy of RPUF was significantly enhanced by the incorporation of IPDI-GO, as evidenced by a reduction in peak heat release rate (PHRR) by 25% and total smoke production (TSP) by 15% in comparison to pure RPUF when IPDI-GO was incorporated at 3 wt%. Scanning electron microscopy (SEM) revealed that IPDI-GO contributed to the formation of a compact, continuous char layer on the RPUF surface. This study underscores the potential of IPDI-GO as a promising flame retardant additive for RPUF.

Exploring cheap and efficient oxygen evolution reaction (OER) catalysts is extremely vital for the commercial application of advanced energy storage and conversion systems. Herein, a self-supporting Co3S4/ S-doped reduced graphene oxide ( Co3S4/S-rGO) film catalyst is successfully prepared by a blade coating coupled with high-temperature annealing strategy, and its morphology, structure and composition are measured and analyzed. It is substantiated that the as-synthesized Co3S4/ S-rGO film possesses unique self-supporting structure, and is composed of uniformly dispersed Co3S4 nanoparticles and highly conductive S-rGO, which benefit the exposure of catalytic sites and electron transfer. By reason of the synergistic effect of the two individual components, the self-supporting Co3S4/ S-rGO film catalyst displays outstanding catalytic performance towards OER. As a consequence, the Co3S4/ S-rGO film catalyst delivers an overpotential of 341 mV at 10 mA cm-2, and the current attenuation rate is only 2.6% after continuous operation for 4 h, verifying excellent catalytic activity and durability. Clearly, our results offers a good example for the construction of high-performance self-supporting carbon-based composite film catalysts for critical electrocatalytic reactions.

In this study, we synthesized a reduced graphene oxide-manganese dioxide (rGO-MnO2) composite material using a one-step hydrothermal method and used it as a transducer layer in solid-state ion-selective electrodes (ISEs) for monitoring potassium and sodium ions in sweat. The rGO-MnO2 composite was characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD), revealing its unique surface morphology and crystalline structures. Electrochemical characterizations, including cyclic voltammetry (CV) and potential response testing, demonstrated the excellent performance of the rGO-MnO2 composite material as a transducer layer in ISEs. The fabricated electrodes displayed good linear responses to potassium and sodium ions, with a voltage response of 36.4 mV and 47.6 mV per unit concentration change, respectively. The electrodes also exhibited improved resistance to gas interference, such as O2, N2, and CO2. We utilized these ISEs to measure changes in potassium and sodium ion concentrations in sweat samples collected over nine days of exercise, demonstrating the practical application of the rGO-MnO2-based ISEs. This work highlights the potential of using graphene/metal oxide composites as solid contact materials in ISEs for cost-effective and stable ion sensing applications.

This article presents the crucial role played by the French underground research laboratory (URL) in initiating the deep geological repository project Cigéo. In January 2023, Andra finalized the license application for the initial construction of Cigéo. Depending on Government’s decision, the construction of Cigéo may be authorized around 2027. Cigéo is the result of a National program, launched in 1991, aiming to safely manage high-level and intermediate level long-lived radioactive wastes. This National program is based on four principles: 1) excellent science and technical knowledge, 2) safety and security as primary goals for waste management, 3) high requirements for environment protection, 4) transparent and openpublic exchanges preceding the democratic decisions and orientations by the Parliament. The research and development (R&D) activities carried out in the URL supported the design and the safety demonstration of the Cigéo project. Moreover, running the URL has provided an opportunity to gain practical experience with regard to the security of underground operations, assessment of environmental impacts, and involvement of the public in the preparation of decisions. The practices implemented have helped gradually build confidence in the Cigéo project.

This study aimed to develop a solid self-nanoemulsifying drug delivery system (solid-SNEDDS) to enhance the formulation of ketoconazole (KTZ), a BCS Class II drug with poor solubility. Ketoconazole, which is insoluble above pH 3, requires solubilization for effective delivery. This SNEDDS comprises oil, surfactant, and co-surfactant, which spontaneously emulsify in the gastrointestinal tract environment to form nanoemulsions with droplet sizes less than 100 nm. The optimal SNE-vehicle composition of oleic acid, TPGS, and PEG 400 at a 10:80:10 weight ratio was determined based on the smallest droplet size achieved. This composition was used to prepare liquid SNEDDS containing ketoconazole. The droplet size and polydispersity index (PDI) of the resulting liquid SNEDDS were analyzed. Subsequently, solid-SNEDDS was fabricated using a spray-drying method with solidifying carriers such as silicon dioxide, crospovidone, and magnesium alumetasilicate. The physicochemical properties of the solid-SNEDDS were characterized by scanning electron microscopy and powder X-ray diffraction, and its solubility, droplet size, and PDI were evaluated. In particular, the solid-SNEDDS containing ketoconazole and crospovidone in a 2:1 weight ratio exhibited significantly enhanced solubility, highlighting its potential for improved medication adherence and dissolution rates.

In this study, Ni-Y2O3 powder was prepared by alloying recomposition oxidation sintering (AROS), solution combustion synthesis (SCS), and conventional mechanical alloying (MA). The microstructure and mechanical properties of the alloys were investigated by spark plasma sintering (SPS). Among the Ni-Y2O3 powders synthesized by the three methods, the AROS powder had approximately 5 nm of Y2O3 crystals uniformly distributed within the Ni particles, whereas the SCS powder contained a mixture of Ni and Y2O3 nanoparticles, and the MA powder formed small Y2O3 crystals on the surface of large Ni particles by milling the mixture of Ni and Y2O3. The average grain size of Y2O3 in the sintered alloys was approximately 15 nm, with the AROS sinter having the smallest, followed by the SCS sinter at 18 nm, and the MA sinter at 22 nm. The yield strength (YS) of the SCS- and MA-sintered alloys were 1511 and 1688 MPa, respectively, which are lower than the YS value of 1697 MPa for the AROS-sintered alloys. The AROS alloy exhibited improved strength compared to the alloys fabricated by SCS and conventional MA methods, primarily because of the increased strengthening from the finer Y2O3 particles and Ni grains.

본 연구는 PEBAX/PVDF 복합막을 제조하고 에탄올/물 혼합액에 대한 투과증발 성능을 평가하였다. 또한 PVDF 지지체 표면에 ZIF-8 층을 형성하여 복합막의 투과증발 성능을 향상시키고자 하였고, PEBAX 선택층 두께에 따른 성능 비교 를 통해 최적의 막을 선정하였다. 제작된 복합막을 물과 에탄올이 95/5 중량비로 혼합된 공급액에 대하여 투과증발 실험을 수행하였다. 그 결과 ZIF-8 충이 형성된 PVDF 지지체를 사용한 복합막의 경우 플럭스 1.98 kg/m2h, 분리 계수 3.88로 일반 PVDF 지지체를 사용한 복합막보다 투과량과 선택도가 모두 높은 값을 나타내었다.