• Animal Bioscience
• /
• v.37 no.2
• /
• pp.274-283
• /
• 2024

Objective: The aim of the study was to evaluate the physicochemical properties (nutrient composition, pH, water content and activity, sorption properties) and mechanical properties (compression force and energy) of granulated feed mixtures with various inclusion levels of crude fibre concentrates ARBOCEL and VITACEL for broiler chickens, i.e. +0.0% (control group - group C), +0.3%, +0.8%, +1.0%, +1.2%. Methods: The feed mixtures were analyzed for their physicochemical properties (nutrient composition by near-infrared spectroscopy, pH with the use a CP-401 pH meter with an IJ-44C glass electrode, water content was determined with the drying method and activity was determined with the Aqua Lab Series 3, sorption properties was determined with the static method) and mechanical properties (compression force and energy with the use TA-HD plus texture analyzer). The Guggenheim-Anderson-de Boer (GAB) model applied in the study correctly described the sorption properties of the analyzed feed mixtures in terms of water activity. Results: The fibre concentrate type affected the specific surface area of the adsorbent and equilibrium water content in the GAB monolayer (p≤0.05) (significantly statistical). The type and dose of the fibre concentrate influenced the dimensionless C and k parameters of the GAB model related to the properties of the monolayer and multilayers, respectively (p≤0.05). They also affected the pH value of the analyzed feed mixtures (p≤0.05). In addition, crude fibre type influenced water activity (p≤0.05) as well as compression energy (J) and compression force (N) (p≤0.001) (highly significantly statistical) of the feed mixtures. Conclusion: The physicochemical analyses of feed mixtures with various inclusion levels (0.3%, 0.8%, 1.0%, 1.2%) of crude fiber concentrates ARBOCEL or VITACEL demonstrated that both crude fiber types may be used in the feed industry as a feedstuff material to produce starter type mixtures for broiler chickens.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.32 no.1
• /
• pp.39-47
• /
• 2024

In this study, LiDAR-detective black material is synthesized by recycling silicon sludge (SS) that is generated from semiconductor manufacturing process, and its recognition is confirmed using two types of LiDAR sensors (MEMS and Rotating LiDAR). In detail, metal impurities on the surface of SS is removed, followed by coating of titanium dioxide (TiO₂) and subsequent chemical reduction to obtain SS-derived black TiO₂ (SS/bTiO₂) material. As-prepared SS/bTiO₂ is mixed with transparent paint to prepare hydrophilic black paints and applied to a glass substrate using a spray gun. SS/bTiO₂-based paint shows similar blackness (L^*=15.7) compared to commercial carbon black-based paint, and remarkable NIR reflectance (26.5R%, 905nm). Furthermore, MEMS and Rotating LiDAR have successfully detected the SS/bTiO₂-based paint. This is attributed to the occurrence of high reflection of light at the interface between the black TiO₂ and the silicon sludge according to the Fresnel's reflection principle. Hence, the new application field to effectively recycle silicon sludge generated in the semiconductor manufacturing process has been presented.

• Journal of Space Technology and Applications
• /
• v.4 no.1
• /
• pp.48-61
• /
• 2024

In this paper, we introduce the concept of the cube satellite Chungnam National University Laser Unity Bus (CLUB), which can provide an integrated infrastructure for various ground-space laser applications. With the advent of the new space era, the rapid expansion of space utilization has begun to reveal the limitations of conventional radio frequencies. As space missions diversify, lasers are garnering attention as a viable alternative. Between ground and space, lasers are applied in various fields including satellite laser ranging (SLR), laser weapons, and laser communication. However, laser used between the ground and space are significantly influenced by the Earth's atmosphere. Consequently, understanding the atmospheric effects on laser propagation is crucial. In particular, atmospheric turbulence, which refracts and distorts laser beams, intensifies closer to the Earth's surface, exerting a greater impact on the uplink than on the downlink. While downlink verification is facilitated by ground detection, verifying the uplink poses challenges due to the necessity of space-based detection. In response to these challenges, we propose the idea of cube satellite as a means to enhance understanding and verification of laser propagation in the uplink. Additionally, we present the results of conceptual design by analyzing requirements, focusing on mission design of the CLUB cube satellite, following the stages of systems engineering for systematic cube satellite development.

• Journal of the Korean earth science society
• /
• v.45 no.3
• /
• pp.173-191
• /
• 2024

Typhoons are significant meteorological phenomena that cause interactions among the ocean, atmosphere, and land within Earth's system. In particular, wind speed, a key characteristic of typhoons, is influenced by various factors such as central pressure, trajectory, and sea surface temperature. Therefore, a comprehensive understanding based on actual observational data is essential. In the 2015 revised secondary school textbooks, typhoon wind speed is presented through text and illustrations; hence, exploratory activities that promote a deeper understanding of wind speed are necessary. In this study, we developed a data visualization program with a graphical user interface (GUI) to facilitate the understanding of typhoon wind speeds with simple operations during the teaching-learning process. The program utilizes red-green-blue (RGB) image data of Typhoons Mawar, Guchol, and Bolaven -which occurred in 2023- from the Korean geostationary satellite GEO-KOMPSAT-2A (GK-2A) as the input data. The program is designed to calculate typhoon wind speeds by inputting cloud movement coordinates around the typhoon and visualizes the wind speed distribution by inputting parameters such as central pressure, storm radius, and maximum wind speed. The GUI-based program developed in this study can be applied to typhoons observed by GK-2A without errors and enables scientific exploration based on actual observations beyond the limitations of textbooks. This allows students and teachers to collect, process, analyze, and visualize real observational data without needing a paid program or professional coding knowledge. This approach is expected to foster digital literacy, an essential competency for the future.

• Applied Chemistry for Engineering
• /
• v.35 no.3
• /
• pp.248-254
• /
• 2024

In this study, functional substances with antibacterial properties were extracted from the needles of Abies holophylla and Pinus koraiensis, and optimized using the central composite design-response surface methodology (CCD-RSM). The optimal extraction conditions for Abies holophylla were an extraction temperature of 59.5 ℃ and an ethanol/ultrapure water volume ratio of 69.5 vol.%, resulting in an extraction yield of 13.5% and inhibition diameters of 11.6 mm against Escherichia coli (E. coli) and 9.3 mm against Staphylococcus aureus (S. aureus). For Pinus koraiensis, the optimal extraction conditions were an extraction temperature of 59.2 ℃ and an ethanol/ultrapure water volume ratio of 67.8 vol.%, resulting in an extraction yield of 4.8% and inhibition diameters of 7.9 mm against E. coli and 12.5 mm against S. aureus. The actual experimental results under these optimal conditions showed that an extraction yield from Abies holophylla needles was 13.0% and an inhibition diameter of 11.7 mm against E. coli and 9.2 mm against S. aureus, indicating an error rate of approximately ± 2.3%. For Pinus koraiensis needles, the extraction yield was 5.1%, with inhibition diameters of 7.5 mm against E. coli and 12.3 mm against S. aureus, indicating an error rate of ± 4.23%.

• Applied Chemistry for Engineering
• /
• v.35 no.3
• /
• pp.192-199
• /
• 2024

In this study, carbamazepine (CBZ) imprinted starch/PVA-based biomaterials were prepared by the casting method and UV irradiation, and their physicochemical properties, CBZ adsorption ability, and release properties were investigated. The surface properties of the prepared biomaterials were characterized using FE-SEM, while the stability of CBZ under UV irradiation and the functional groups of the biomaterials were characterized using FT-IR analysis. The adsorption properties of CBZ on the biomaterials were evaluated by binding isotherm and Scatchard plot. Results indicate that CBZ imprinted biomaterials possess a specific binding site of CBZ. To evaluate the applicability of the transdermal drug delivery system, the release properties of CBZ from prepared biomaterials using various pH buffers and artificial skin at 36.5 ℃ were investigated. Results indicated that the CBZ release at high pH was faster than at low pH. In addition, CBZ was released continuously for 12 h in the artificial skin test. The drug release mechanism of CBZ followed a pseudo-Fickian diffusion mechanism in buffer solution, whereas the release from artificial skin exhibited a non-Fickian diffusion mechanism.

• Applied Chemistry for Engineering
• /
• v.35 no.4
• /
• pp.316-320
• /
• 2024

To optimize the emulsion stability and antibacterial activity against Escherichia coli (E. coli) of cosmeceuticals using Scutellaria baicalensis extracts and olive wax as natural emulsifiers, we conducted a study. The independent variables were the amounts of Scutellaria baicalensis extracts and olive wax added. The response variables included the emulsion stability index (ESI) of the cosmeceuticals product and the inhibition diameter against E. coli. Through central composite design-response surface methodology (CCD-RSM), we obtained a statistically significant and reliable regression equation within a 95% confidence interval. By optimizing multiple responses, we determined that the optimal emulsification conditions that satisfied both ESI and E. coli inhibition diameter were 3.7 wt% of Scutellaria baicalensis extracts and 2.7 wt% of olive wax. The predicted ESI and E. coli inhibition diameter were 97.9% and 9.7 mm, respectively. When actual experiments were conducted under the optimal conditions, the measured ESI and E. coli inhibition diameter were 95.0% and 9.4 mm, respectively, with an average error rate of 3.2 ± 0.4%.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.17 no.2
• /
• pp.73-80
• /
• 2009

Biofilters use porous solid media to support microorganisms and allow access to the contaminants in the airflow. The characteristics of media used in biofilters vary greatly, and therefore it is important to select the appropriate media in order to obtain a large enough surface attachment area and uniform pore. This study was performed to compare hydrogen sulfide ($H_2S$) removal efficiencies of three biofilter media; coconut fiber, ceramic, and polyurethane. The biofilter packed with coconut fiber showed stable removal activity when inlet loading was changeable, and was restored rapidly when the moisture content decreased. However, the coconut fiber suffered from low durability. To cope with this problem a media of fibrinous polypropylene was developed to strengthen the durability of the coconut fiber. Biofilter column experiments using the fibrinous polypropylene media demonstrated over 99% of removal efficiencies at pH as low as 3 and 6 seconds of EBRT (empty bed gas residence time). Due to its superior physical characteristics, it is expected that the $H_2S$ treatment performance will increase when the new fibrinous polypropylne media is applied in commercial biofilter systems.

• International Journal of Stem Cells
• /
• v.15 no.4
• /
• pp.405-414
• /
• 2022

Background and Objectives: Chronic inflammation of bone tissue often results in bone defects and hazards to tissue repair and regeneration. Cannabidiol (CBD) is a natural cannabinoid with multiple biological activities, including anti-inflammatory and osteogenic potential. This study aimed to investigate the efficacy and mechanisms of CBD in the promotion of bone marrow mesenchymal stem cells (BMSCs) osteogenic differentiation in the inflammatory microenvironment. Methods and Results: BMSCs isolated from C57BL/6 mice, expressed stem cell characteristic surface markers and presented multidirectional differentiation potential. The CCK-8 assay was applied to evaluate the effects of CBD on BMSCs' vitality, and demonstrating the safety of CBD on BMSCs. Then, BMSCs were stimulated with lipopolysaccharide (LPS) to induce inflammatory microenvironment. We found that CBD intervention down-regulated mRNA expression levels of inflammatory cytokines and promoted cells proliferation in LPS-treated BMSCs, also reversed the protein and mRNA levels downregulation of osteogenic markers caused by LPS treatment. Moreover, CBD intervention activated the cannabinoid receptor 2 (CB2) and the p38 mitogen-activated protein kinase (MAPK) signaling pathway. While AM630, a selective CB2 inhibitor, reduced phosphorylated (p)-p38 levels. In addition, AM630 and SB530689, a selective p38 MAPK inhibitor, attenuated the enhancement of osteogenic markers expression levels by CBD in inflammatory microenvironment, respectively. Conclusions: CBD promoted osteogenic differentiation of BMSCs via the CB2/p38 MAPK signaling pathway in the inflammatory microenvironment.

• Applied Chemistry for Engineering
• /
• v.34 no.6
• /
• pp.613-618
• /
• 2023

Modern society spends more than 80% of its daily life indoors, emphasizing the need for attention to indoor air pollution due to the improvement in living standards. In this study, the performance and reaction characteristics of the Pt/TiO₂ catalysts prepared by liquid-phase reduction for the removal of formaldehyde (HCHO), one of the indoor air pollutants, at room temperature without the need for additional light or heat were investigated. As a result, it showed that catalysts prepared by the same method showed approximately 40~80% various activities depending on the type of TiO₂. XRD, BET, and XPS analyses were performed to investigate the particle size, crystal structure, specific surface area, and O/Ti molar ratio of the support material, and it revealed that the correlation between the properties and performance was insignificant. To explore the oxidation reaction pathway of formaldehyde (HCHO), in situ DRIFT analysis using carbon monoxide and H₂-TPR was perfomed. The results revealed that the performance was demonstrated by the oxidation state of the active metal and the adsorption-desorption characteristics of the adsorbate species.