The MBR process, which uses membrane to separate solids instead of secondary clarifier, has the advantage of maintaining high MLSS (Mixed Liquor Suspended Solids) concentration in bioreactors. In this study, three MBR processes combined with chemical phosphorus removal facility were studied: the phase-isolated MBR process with one recirculation pump, the A2O MBR process with two recirculation pumps, and the MBR process without a oxygen depletion reactor with three recirculation pumps. 116 simulations by EQPS (Effluent Quality Prediction System) were performed, under same design influent characteristics and hydraulic retention time, to see the effects of recirculation ratio changes on effluent water quality. The final effluent limits for total nitrogen and phosphorus were set to as 10 ㎎/L or less and 0.2 ㎎/L or less, respectively. AlCl3 was fed at MBR effluent to make 0.2 ㎎/L of total phosphorus precisely by PI (Proportional-Integral) controller in EQPS. This study showed that the phase isolated MBR process (R1 600%) had the highest nitrogen removal efficiency, with a final effluent T-N concentration of 6.765 mg/L. However, the A2O MBR process (R1 400%, R2 100%) required the lowest AlCl3 flow of 0.742 m3/day, which is approximately 59.1% lower than the average AlCl3 flow of the phase-isolated MBR process. It also produced 4,835 kg/day of sludge, the lowest among the studying MBR processes. It seems that A2O MBR process is the most economic method to treat studying wastewater to meet final effluent nutrient limit targets. However, carbon neutrality must be considered to select the best process to treat studying wastewater and it will be presented later.

This review examines the microstructural and mechanical properties of a Ti-6Al-4V alloy produced by wrought processing and powder metallurgy (PM), specifically laser powder bed fusion (LPBF) and hot isostatic pressing. Wrought methods, such as forging and rolling, create equiaxed alpha (α) and beta (β) grain structures with balanced properties, which are ideal for fatigue resistance. In contrast, PM methods, particularly LPBF, often yield a martensitic α′ structure with high microhardness, enabling complex geometries but requiring post-processing to improve its properties and reduce stress. The study evaluated the effects of processing parameters on grain size, phase distribution, and material characteristics, guiding the choice of fabrication techniques for optimizing Ti-6Al-4V performance in aerospace, biomedical, and automotive applications. The analysis emphasizes tailored processing to meet advanced engineering demands.

시멘트 콘크리트 포장의 양생 공정에서는 피막양생제를 살포하는 것이 가장 일반적이며 양생포와 같은 덮개를 콘크리트 포장 위에 덮어 온도와 습도를 유지하는 방법으로 콘크리트 포장의 강도를 발현시키기도 한다. 콘크리트 포장의 미끄럼 저항 및 배수, 주행안전 성을 향상시키기 위해서는 양생 공정 이전에 표면 타이닝 공정을 수행하는 것이 일반적이지만 양생 이후에 그루빙을 실시하기도 한다. 본 연구에서는 콘크리트 포장 품질에 지대한 영향을 주는 양생 작업과 표면 그루빙 작업의 일원화 방법 개발을 위한 기초 연구로써 3D 스케치 프로그램과 3D 프린터를 이용하여 타원형, 삼각형, 사각형 모양의 홈으로 그루빙을 형성하면서 동시에 양생포로 사용이 가 능한 그루빙 양생 플레이트를 설계하여 제작하였다. 그루빙 양생 플레이트의 적용성을 분석하기 위해 콘크리트 공시체를 제작하여 실 내 실험을 수행하였으며 양생 플레이트의 그루빙 홈 형상에 따른 콘크리트 포장 표면 그루빙 형성 상태를 분석하였다.

The condensation phenomenon can affect the product in terms of function and aesthetics, so it is a complaint of many users from the past, and continuous research has been conducted to solve it. A portable instrument panel is installed inside combat vehicles such as tanks and armored vehicles. Due to the nature of the combat vehicle operated in the special situation of battle, the internal heat generation of the instrument panel has increased significantly, which is presumed to be the cause of condensation inside the instrument panel. In this paper, a study on the development of subsequent processes was conducted to reduce the condensation phenomenon of the instrument panel for combat vehicles. In order to reduce the condensation phenomenon, the experiment was carried out by setting baking time and stabilization time as major factors. This paper is considered to be a reference research data for all systems in which similar assemblies are used as well as instrument panels for combat vehicles.

There are two primary sludge drying methods such as the direct heating microwave method and the indirect heating steam one. In this study, the drying treatment facility at sewage treatment plant A applied both of these drying methods. The research aimed to investigate the optimal operation approach for the drying facility, considering the input sludge and the moisture content data after the drying process. Moisture content and removal rate data were executed at the research facility from January 2016 to December 2018. First, the microwave, a direct heating drying method, performed intensive drying only on the outer surface of the sludge by directly applying heat to the sludge using far infrared rays, so effective sludge drying was not achieved. On the other hand, the steam method of the indirect heating method used steam from a gas boiler to maximize the utilization of the heat transfer area and reduce energy of the dryer, resulting in an effective sludge drying efficiency. The sludge moisture content brought into the sludge drying facility was about 80%, but the moisture content of the sludge that went through the drying facility was less than 10% of the design standard. Therefore, the steam method of the indirect heating method is more effective than the microwave method of the previous direct heating method and is more effective for maintenance It has proven that it is an efficient method of operating construction facilities.

Lycium barbarum extract has a high potential to be developed as a health functional food due to the various health-promoting effects of Lycium barbarum. This study analyzed changes in nutritional and functional components depending on the extraction solvent (purified water and a mixture of purified water and alcohol) and the condition of the sample. The nutritional components (carbohydrates, protein, fat, ash), organic acids, amino acids, total phenolic compounds, and total flavonoids of the extract produced during the extraction process were analyzed. The nutritional composition and functional substances of the extracts showed some differences depending on the type of solvent and the condition of the sample. The amounts of crude protein (7.61%), crude fat (1.63%), carbohydrate (90.22%), and ash (0.54%) of dried Lycium barbarum extract using purified water as a solvent were similar to those of the powder sample extract. The highest content of citric acid was 4.31 mg/mL, similar to the case of acetic acid, when the powder sample used a mixture of purified water and alcohol as a solvent. The highest amino acid content was 357.39 mg/mL when the powder sample was mixed with purified water and alcohol as a solvent. The total amount of phenolic compounds was 686.16 g/L when the powder sample was extracted with a mixture of purified water and alcohol as a solvent. The highest total flavonoid content was 111.32 g/L when the powder sample was extracted with a mixture of purified water and alcohol as a solvent.

Graphene quantum dots (GQDs) are zero-dimensional carbonous materials with exceptional physical and chemical properties such as a tuneable band gap, good conductivity, quantum confinement, and edge effect. The introduction of GQDs in various layers of solar cells (SCs) such as hole transport layer (HTL), electron transport materials (ETM), cathode interlayer (CIL), photoanode materials (PAM), counter electrode (CE), and transparent conducting electrode (TCE) could improve the solar energy (SE) harvesting, separation and transportation of electrons and hole, thus ultimately enhance the overall performance and stability of SCs. The incorporation of GQDs in various layers such as HTL, ETM, CIL, PAM, CE, and TCE achieved photo conversion efficiencies (PCEs) of 18.63, 21.1, 12.81, 9.41, 8.1, and 3.66%, respectively. Furthermore, GQDs improved stabilities such as resistance to degradation for HTL (up to 77%), ETM (80%), resistance to UV light for ETM (94%), resistance to temperature in ETM (90%), and bending stabilities after 1000 cycles for HTL (88%) and for TCE (90%). There are reviews focused on the utilization of different carbon-structured materials such as graphene, carbon nanotubes (CNT), fullerenes, and carbon dots in SCs applications. More specifically, the utilization of GQDs for SCs is limited and yet to be explored in greater detail. This review mainly focuses on the recent advancement of various techniques of production of GQDs synthesis, utilization of GQDs in various layers like HTL, ETM, CIL, PAM, CE, and TCE for the enhancement of PCE, and the stability of SCs. As a result, we believe that an exclusive study on GQDs-sensitized solar cells (GQDSSCs) could provide an in-depth analysis of the recent progress, achievements, and challenges.