높은 내화학성과 소수성 특성을 갖는 polymethylpentene (PMP) 소재는 polypropylene 소재 대비 결정성이 낮아 dense skin층을 갖는 비대칭 분리막을 제조하기 수월하지만 녹는점이 높아 가공이 용이하지 않다. 본 연구에서는 비용매 유도 상분리법(NIPS)과 열유도 상분리법(TIPS)을 혼합한 N-TIPS 법을 활용하여 polymethylpentene (PMP) 고분자 분리막을 제조 하고 성능과 특성을 평가하였다. Cyclohexane을 용매로 사용하여 PMP 도프용액을 제조하였으며, 상전이조로 물, EtOH, IPA 를 사용하였다. Cyclohexane과 섞이지 않는 물을 비용매로 상전이한 분리막은 TIPS 영향으로 인해 큰 기공과 높은 기체 투과 도를 보였으나, 표면이 거칠고 구조가 불안정한 특성을 보였다. 반면, cyclohexane과 혼합될 수 있는 알코올류(ethanol, isopropanol) 를 상전이조로 사용한 경우 NIPS 효과로 인해 dense skin층이 형성됨을 확인하며, 높은 기계적 강도를 보였다. 추가 적인 기공형성을 위해 polyethylene glycol (PEG)를 첨가한 경우 기체투과도가 높아지는 결과를 얻을 수 있었다.

본 연구는 폴리케톤(PK) 지지체를 이용한 유기용매 역삼투(OSRO) 분리막 제조를 목적으로 하였다. 비용매 유도 상분리 방법(NIPS)을 통해 PK 지지체를 제작하였고, PK 지지체 위에 polyamide layer를 계면 중합하여 thin-film composite (TFC) 형태로 OSRO 분리막을 완성하였다. 이후 OSRO 분리막의 표면과 단면 구조 및 표면의 화학적 구조를 분석하였고 수 투과도와 염 제거율은 각각 약 1.28 LMH/bar와 99.0%의 결과를 얻었다. 또한 OSRO 분리막의 polyamide layer는 유기용매 침지 1일 동안 매우 안정적이었고, 단일 유기용매 투과도 경향성은 유기용매 나노여과(OSN) 분리막의 투과도 모델과 일치하 였다. OSRO 분리막의 MWCO는 MeOH 상에서 240 g/mol이었다. OSRO 분리막의 MeOH-toluene 혼합용액에 대한 투과도 와 separation factor는 상용 OSN 분리막보다 각각 200%와 60%의 높은 결과를 얻었다.

To develop farm-made high effective vinegar, this study prepared apple vinegar using four kinds of acetic acid bacteria isolated from a natural fermentation liquid of ‘Cheongsoo’ grapes and analyzed vinegar samples fermented 93% apple juice and 7% alcohols at 30℃ for 20 days. To accomplish this, quality characteristics such as pH, total acidity, reducing sugar, organic acid, color, total polyphenol contents, and antioxidant activity contents were determined. The pH decreased while total acidity of all samples gradually increased during fermentation period. The vinegar with AP 21 strain tended to increase the total acidity quicker than other stains. Reduced sugar content remained high until the last fermentation day. Furthermore, reduced sugar contents of all vinegars increased as fermentation progressed by decomposing sucrose present in apples. When physiological activities were compared, apple vinegars fermented with AP 21 and 30 strains had higher total polyphenol and flavonoid contents than other samples. However, there was no significant difference in antioxidant activity between samples. These results indicate that strain 21 is the most suitable starter as acetic acid bacteria for producing farm-made vinegar.

이 연구에서는 국내산 중·소경목 이용확대 및 목재마루판으로써 효율적인 활용을 위하여 남양재인 티크, 멀바우와 국내산재인 낙엽송과 백합나무를 혼합적층한 직교형적층패널을 제작하였고, 상온침지 및 내수 침지박리시험을 실시하여 치수안정성과 내수성을 조사하였다. 상온에서 24시간 침지 후 측정한 흡수율은 3.4% - 6.8%의 범위에 있었고, TLa (Teak-Larch)가 가장 높은 값을 나타내었다. 흡수두께팽창률은 TTu (Teak-Tulip tree)가 4.7%로 가장 낮았고, TLa가 7.0%로 가장 높은 값을 나타내었다. TLa를 제외한 모든 시험편이 KS에 고시된 목재제품의 규격과 품질기준 6%이하에 부합하였다. 내수침지박리시험 후의 박리율의 경우, TLa가 1.1%로 가장 낮았고, MLa (Merbau-Larch)가 50%로 가장 높은 값을 나타내었다. MTu (Merbau-Tulip tree)와 TLa는 KS에 고시된 품질기준에 부합하였으나, MLa와 TTu는 고시된 품질기준에 부합하지 못하는 것이 확인되었다. 내수침지박리시험 후의 흡수율과 흡수두께팽창률은 각각 13.3% (TLa) - 29.1% (MTu), 7.5% (TTu) - 9.8% (MTu)의 범위로 흡수율은 4.3배, 흡수두께팽창률은 1.4배 상온침지 후의 그것보다 증가하는 것이 확인되었다.

In this study, we report significant improvements in lithium-ion battery anodes cost and performance, by fabricating nano porous silicon (Si) particles from Si wafer sludge using the metal-assisted chemical etching (MACE) process. To solve the problem of volume expansion of Si during alloying/de-alloying with lithium ions, a layer was formed through nitric acid treatment, and Ag particles were removed at the same time. This layer acts as a core-shell structure that suppresses Si volume expansion. Additionally, the specific surface area of Si increased by controlling the etching time, which corresponds to the volume expansion of Si, showing a synergistic effect with the core-shell. This development not only contributes to the development of high-capacity anode materials, but also highlights the possibility of reducing manufacturing costs by utilizing waste Si wafer sludge. In addition, this method enhances the capacity retention rate of lithium-ion batteries by up to 38 %, marking a significant step forward in performance improvements.

This study focused on improving the solubility of silodosin, a drug poorly soluble in water, by utilizing solid dispersions. Three types of dispersions were examined and compared against the drug powder: surface-attached (SA), solvent-wetted (SW), and solvent-evaporated (SE). Polyvinyl alcohol (PVA) was identified as the most effective polymer in enhancing solubility. These dispersions were prepared using spray-drying techniques with silodosin and PVA as the polymer, employing solvents such as water, ethanol, and a water-acetone mix. The physicochemical properties and solubility of the dispersions were evaluated. The surface-attached dispersions featured the polymer on a crystalline drug surface, the solvent-wetted dispersions had the amorphous drug on the polymer, and the solvent-evaporated dispersions produced nearly round particles with both components amorphous. Testing revealed that the order of improved solubility was: solvent-evaporated, solvent-wetted, and surface-attached. The results demonstrated that the preparation method of the solid dispersions significantly impacted their physicochemical properties and solubility enhancement.

Molten salt reactors represent a promising advancement in nuclear technology due to their potential for enhanced safety, higher efficiency, and reduced nuclear waste. However, the development of structural materials that can survive under severe corrosion environments is crucial. In the present work, pure Ni was deposited on the surface of 316H stainless steel using a directed energy deposition (DED) process. This study aimed to fabricate pure Ni alloy layers on an STS316H alloy substrate. It was observed that low laser power during the deposition of pure Ni on the STS316H substrate could induce stacking defects such as surface irregularities and internal voids, which were confirmed through photographic and SEM analyses. Additionally, the diffusion of Fe and Cr elements from the STS316H substrate into the Ni layers was observed to decrease with increasing Ni deposition height. Analysis of the composition of Cr and Fe components within the Ni deposition structures allows for the prediction of properties such as the corrosion resistance of Ni.

해당 연구는 산업 폐수에서 염료를 효율적으로 제거하기 위한 고급 박막 나노복합체(TFN) 기반 나노여과막을 개 발하여 효과적인 폐수 처리 방법을 제시합니다. 최근 연구의 동향을 보면, 나노카본, 실리카 나노스피어, 금속-유기 프레임워 크(MOF) 및 MoS2와 같은 혁신적인 재료를 포함하는 TFN 막의 제조에 중점을 둡니다. 주요 목표는 염료 제거 효율을 향상 시키고 오염 방지 특성을 개선하며 염료/염 분리에 대한 높은 선택성을 유지하는 것입니다. 이 논문은 넓은 표면적, 기계적 견고성 및 특정 오염 물질 상호 작용 능력을 포함하여 이러한 나노 재료의 뚜렷한 이점을 활용하여 현재 나노여과 기술의 제 한을 극복하고 물 처리 문제에 대한 지속 가능한 솔루션을 제공하는 것을 목표로 합니다.

The objective of this study is to identify the priority of elements for effective implementation of MES in small and medium-sized manufacturing enterprises trying to develop into smart factories. For this purpose, the Delphi method and the Analytic Hierarchy Process(AHP) mothod are applied. As a result of the study, the cooperation of the members in the supply chain is the most important factor for small and medium-sized enterprises in order to survive in the global competitive environment. Therefore, the enterprises need to make various efforts to create synergies through the technical strength of suppliers and the cooperation in the process of introducing and operating MES.

우리나라 제조 소기업은 온실가스 고배출 업종이 많고, 산재사망사고 발생 비중이 높아 수출의존도가 높은 국내 제조 소기업에 대한 ESG 이슈 관리가 점차 중요해 질 것이다. 본 연구는 제조 소기업의 저탄소 활동이 현장 작업자의 안전의식과 산업재해에 미치는 영향을 파악하고, 저탄소 활동이 안전, 고용 등의 영역에서 발생하는 부정적 영향을 감소 시켜 기업의 경쟁력을 향상시킬 수 있는 방안을 모색해 보았다. 연구에서는 제조 소기업의 저탄소 활동(저탄소 전략 및 시스템 활동, 온실가스 및 환경오염 분야 활동, 자원 및 에너 지 분야 활동)이 산업안전 인식 향상에 긍정적(+)인 영향을 미치는 것을 확인하고, 저탄소 활동에 참여한 기업들의 산업재해율이 감소하였으며, 매출과 고용이 증가하는 성과가 나 타난 것을 확인하였다. 따라서 정부는 제조 소기업의 저탄소 활동과 산업안전, 고용창출이 연계될 수 있도록 정책적인 지원을 통해 지속가능한 성장을 위한 핵심 경영 전략으로 자리 잡게 해야 한다.

As environmental concerns escalate, the increase in recycling of aluminum scrap is notable within the aluminum alloy production sector. Precise control of essential components such as Al, Cu, and Si is crucial in aluminum alloy production. However, recycled metal products comprise various metal components, leading to inherent uncertainty in component concentrations. Thus, meticulous determination of input quantities of recycled metal products is necessary to adjust the composition ratio of components. This study proposes a stable input determination heuristic algorithm considering the uncertainty arising from utilizing recycled metal products. The objective is to minimize total costs while satisfying the desired component ratio in aluminum manufacturing processes. The proposed algorithm is designed to handle increased complexity due to introduced uncertainty. Validation of the proposed heuristic algorithm's effectiveness is conducted by comparing its performance with an algorithm mimicking the input determination method used in the field. The proposed heuristic algorithm demonstrates superior results compared to the field-mimicking algorithm and is anticipated to serve as a useful tool for decision-making in realistic scenarios.

This study introduces a novel approach for identifying potential failure risks in missile manufacturing by leveraging Quality Inspection Management (QIM) data to address the challenges presented by a dataset comprising 666 variables and data imbalances. The utilization of the SMOTE for data augmentation and Lasso Regression for dimensionality reduction, followed by the application of a Random Forest model, results in a 99.40% accuracy rate in classifying missiles with a high likelihood of failure. Such measures enable the preemptive identification of missiles at a heightened risk of failure, thereby mitigating the risk of field failures and enhancing missile life. The integration of Lasso Regression and Random Forest is employed to pinpoint critical variables and test items that significantly impact failure, with a particular emphasis on variables related to performance and connection resistance. Moreover, the research highlights the potential for broadening the scope of data-driven decision-making within quality control systems, including the refinement of maintenance strategies and the adjustment of control limits for essential test items.

This study is to manufacture a titanium dioxide (TiO2) photocatalyst by recycling sludge generated using titanium tetrachloride (TiCl4) as a coagulant. Compared to general sewage, a TiCl4 coagulant was applied to dyeing wastewater containing a large amount of non-degradable organic compounds to evaluate its performance. Then the generated sludge was dried and fired to prepare a photocatalyst (TFS). Scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDX), X-ray diffraction (XRD), and nitrogen oxide reduction experiments were conducted to analyze the surface properties and evaluate the photoactive ability of the prepared TFS. After using titanium tetrachloride (TiCl4) as a coagulant in the dyeing wastewater, the water quality characteristics were measured at 84 mg/L of chemical oxygen demand (COD), 10 mg/L of T-N, and 0.9 mg/L of T-P to satisfy the discharge water quality standards. The surface properties of the TFS were investigated and the anatase crystal structure was observed. It was confirmed that the ratio of Ti and O, the main components of TiO2, accounted for more than 90 %. As a result of the nitric oxide (NO) reduction experiment, 1.56 uMol of NO was reduced to confirm a removal rate of 20.60 %. This is judged to be a photocatalytic performance similar to that of the existing P-25. Therefore, by applying TiCl4 to the dyeing wastewater, it is possible to solve the problems of the existing coagulant and to reduce the amount of carbon dioxide generated, using an eco-friendly sludge treatment method. In addition, it is believed that environmental and economic advantages can be obtained by manufacturing TiO2 at an eco-friendly and lower cost than before.

Buckwheat leaves have the best antioxidant properties, including flavonoids, rutin, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging ability compared to common buckwheat and tartary buckwheat. The total dietary fiber content of the powder extracted by mixing buckwheat leaves and sea tangle was 30.5%. To manufacture bread containing mixed buckwheat flour, 10, 20, and 30% buckwheat flour was mixed in to produce buckwheat bread. The bread’s characteristics underwent significant changes with varying levels of buckwheat flour. As the buckwheat content increased, the size of the bread decreased, but its hardness, gumminess, and chewiness tended to increase. The sensory characteristics of the bread were not improved due to the addition of gluten in the case of bread mixed with 20% buckwheat flour. When the buckwheat flour content was mixed at 20%, and the mixed extract of buckwheat leaves and sea tangle were added at 0.4% and 1.0%, there was no significant difference in the appearance of the buckwheat bread. Still, regarding sensory properties, the preference was higher in the sample with 1.0% added buckwheat flour.