Pukyong National University

Platooning represents a crucial strategy for mitigating emissions from heavy-duty vehicles (HDVs). This study evaluates the effects of platoon composition on the surrounding airflow utilizing a computational fluid dynamics (CFD) model, and quantifies the resultant fuel efficiency and CO 2 emissions. This study examines fuel consumption data reconstructed from field experiments to validate the CFD model’s ability to accurately simulate drag forces within a homogeneous three-truck platoon. The potential for fuel savings was assessed based on CFD-simulated fuel consumption, taking into account various inter-vehicle distances and driving speeds. The model successfully reproduced the fuel consumption observed in a platooning formation comprising lead, middle, and trailing trucks, with an error margin below 6.2%. Fuel consumption analysis shows that while lead and middle trucks consume more fuel with increased inter-vehicle distances, the trailing truck's consumption decreases at specific distance-to-length ratios (D/L), increasing again beyond a D/L of 1.1. Additionally, a significant decrease in total fuel efficiency was noted for D/L ratios exceeding 1.5. Considering the diverse platooning scenarios analyzed, the study anticipates an annual reduction of up to 7 tons of CO 2 equivalent per vehicle. By optimizing platooning configurations, this research contributes to enhancing fuel efficiency and reducing emissions from HDVs.

Novel ACCEPTER units, difluorophenazine, were prepared and used for the synthesis of the conjugated polymers incorporating electron donor–acceptor pairs for organic photovoltaics. The introduction of a fluorine atom into the phenazine moiety led to a lowering of the highest occupied molecular orbital (HOMO) energy levels of the polymers. These acceptor units are likely to enhance electron transfer properties within the polymer structure. Conjugated polymers containing difluorophenazine, bithiophene and benzodithiophene, were synthesized using the Stille polymerization reaction to produce P1 and P2. The HOMO/LUMO energy levels of P1 and P2 were − 5.75/− 3.83 eV and − 5.81/− 3.78 eV, respectively. P2, which incorporates thiophene units into the benzodithiophene backbone, exhibits lower HOMO energy levels to increase the VOC Value. These energy levels are crucial for potentially enhancing the photovoltaic performance of the polymers. Novel accepter units, difluorophenazine, were prepared and used for the synthesis of the conjugated polymers incorporating electron donor-acceptor pairs for organic photovoltaics. P2, which incorporates thiophene units into the benzodithiophene backbone, exhibits lower HOMO energy levels to increase the VOC Value

Interfacial modification using self‐assembled monolayers (SAMs) is crucial for defect passivation and energy level alignment in perovskite solar cells (PSCs), yet scaling SAMs remains a challenge. Organic SAMs are often too thin for large‐area homogeneous layers through spin‐coating and their hydrophobic nature complicates solution‐based perovskite fabrication, hindering uniform film formation. This study introduces SAM based on phenothiazine core that involves synergistic co‐adsorption of a hydrophilic phosphonic acid with phenothiazine core unit for use as a hole transport layer in p‐i‐n PSCs. The PTZ‐PA SAM improves film formation, energy alignment, and hole extraction, achieving a power conversion efficiency above 23.2%. It also maintains stable performance for over 500 h under continuous illumination, indicating its potential for durable PSCs. PTZ‐PA increases surface energy, overcoming non‐wetting issues and enabling the formation of high‐quality perovskite films with improved morphology and crystallinity. The phosphonic acid group coordinates with lead iodide in the perovskite, enhancing electronic charge transfer and mechanical absorption, which facilitates effective p‐type charge‐selective contacts.

Due to the global supply chain crisis, the container supply chain has been characterized by heightened uncertainty, leading to periodic disruptions in the productivity of container flows. To adeptly navigate these challenges, this study provides individual free‐time policy on hinterland container operation systems in the face of uncertainty. The investigation unfolds through the presentation of two analytical models, rooted in both demurrage‐ and detention‐based models with practical implementation. Within these models, we explicitly formulate each optimization problem within a spectrum of scenarios encompassing the tardiness and earliness of container retrieval and return by a consignee. Through extensive numerical analyses, we elucidate the intricate trade‐offs associated with decision variables of container supply chain members, offering a comprehensive understanding of their impact on the level of uncertainty. Employing a comparative approach, we validate the proposed models by providing valuable insights and guidelines pertaining to optimal demurrage and detention processes among uncertain conditions.

Natural products have emerged as a viable source for cancer prevention and therapy, accounting for over 80% of FDA-approved cancer therapies over the last three decades. Pomegranate juice, known for its potential antioxidant action, has been extensively researched, although its use in cancer treatment remains still unexplored. Lactic acid Bacteria (LAB) is one of the beneficial microorganisms that can increase the bioactivity of fermented foods. The objective of this study was to assess the cancer-fighting potential of cell-free fermented pomegranate juice using lactic acid bacteria on HT-29 cancer cell cultures. The two LAB strains were isolated from the infant feces samples and identified as Lactobacillus pentosus ISB1 and Lactobacillus fermentum ISB2 through the 16s rRNA sequencing method. These strains exhibited 98% survivability under simulated digestive conditions and displayed gamma hemolysis. The LAB fermented juice exhibits both strong antibacterial activity and significant cytotoxic effects against HT-29 human colon cancer cells (IC50 = 32.1 µg/mL). Furthermore, the treatment with fermented pomegranate triggered apoptosis, as demonstrated by DNA fragmentation and nuclear morphological changes. The fermented juice also inhibits mitotic cell division, namely in the G2/M phase. These findings suggest that fermented pomegranate juice has substantial antiproliferative and antibacterial properties, potentially benefiting colon cancer prevention and treatment, as well as broader human health improvements.

This study aimed to enhance ethanol production by increasing the galactose consumption rate of recombinant Saccharomyces cerevisiae CEN-PK2 strains, using the CRISPR-Cas9 system from the hydrolysate of the red macroalgae Eucheuma denticulatum. A concentration of 27.7 g/L of monosaccharides was obtained by thermal acid hydrolysis with 10% (w/v) biomass and 300 mM nitric acid at 121 ℃ for 90 min. More monosaccharide (42.0 g/L) was obtained from subsequent enzymatic saccharification using 20 U/mL of commercial enzyme for 72 h. The ethanol fermentation and galactose uptake rate were compared with those of the wild-type strain of S. cerevisiae CEN-PK2, the COX9- and/or MIG1-gene-deleted strains, and the galactose-adapted strain. A similar glucose consumption rate was observed for all tested strains. However, the ΔMIG1 strain exhibited an enhanced galactose consumption and ethanol yield compared to the ΔCOX9 strain and the control. Furthermore, the strain with a double deletion of COX9 and MIG1 (ΔCOX9ΔMIG1) exhibited an enhanced galactose uptake and ethanol production (31.5 g/L, 0.46 g/g yield, and 0.33 g/L/h productivity). An increase in the transcription levels of the GAL regulatory genes was also observed in the ΔCOX9ΔMIG1 strain. This research could significantly impact future energy development and climate change mitigation by enhancing bioenergy efficiency and expanding its industrial applications.

Quantum information processing introduces novel approaches for classical data encoding to encompass the complex patterns of input data of practical computational challenges using basic principles of quantum mechanics. The classification of diabetes is an example of a problem that can be efficiently resolved by using quantum unitary operations and the variational quantum classifier (VQC). This study demonstrates the effects of the number of qubits, types of feature maps, optimizers’ class, and the number of layers in the parametrized circuit, and the number of learnable parameters in ansatz influences the effectiveness of the VQC. In total, 76 variants of VQC are analyzed for four and eight qubits’ cases and their results are compared with six classical machine learning models to predict diabetes. Three different types of feature maps (Pauli, Z, and ZZ) are implemented during analysis in addition to three different optimizers (COBYLA, SPSA and SLSQP). Experiments are performed using the PIMA Indian Diabetes Dataset (PIDD). The results conclude that VQC with six layers embedded with an error correction scaling factor of 0.01 and having ZZ feature map and COBYLA optimizer outperforms other quantum variants. The optimal proposed model attained the accuracy of 0.85 and 0.80 for eight and four qubits’ cases, respectively. In addition, the final quantum model among 76 variants was compared with six classical machine learning models. The results suggest that the proposed VQC model has outperformed four classical models including SVM, random forest (RF), decision tree (DT), and linear regression (LR).

This study investigates the potential antiobesity effects of Neptunea cumingii extract (NCE). Our findings illustrate that NCE effectively reduces lipid accumulation and triglyceride content, while simultaneously increasing free glycerol release. The reduction in lipid accumulation and induction of lipolysis were evidenced by the downregulation of lipogenesis proteins, such as fatty acid synthase and lipoprotein lipase, and the upregulation of hormone-sensitive lipase expression. Furthermore, the downregulation of adipogenic transcription factors, including peroxisome proliferator–activated receptor gamma, CCAAT/enhancer-binding protein α, and sterol regulatory element-binding protein 1, indicates the inhibition of adipocyte differentiation. Additionally, NCE treatment induced brown adipocyte phenotype by upregulating brown adipose tissue–specific proteins, such as uncoupling protein 1 and peroxisome proliferator–activated receptor-gamma coactivator 1α. Moreover, NCE led to the phosphorylation of AMPK, the master regulator of energy homeostasis. Pharmacological inhibition of AMPK using an AMPK inhibitor (Compound C) attenuated the lipogenesis inhibitory effect of NCE and reduced lipolysis and adipocyte browning. This suggests that AMPK activation is involved in these processes. GC–MS analysis reveals that NCE primarily consists of cholest-5-en-3-ol (27.15%) along with an array of fatty acids which possess favorable antiobesity properties. Collectively, these results highlight the potential of NCE as a lipid-lowering agent for the intervention of obesity.

Chitosan (CTS) and graphene (GR) combinations are attracting the interest of drug delivery sectors due to the combined effects of CTS, having exceptional biotic capabilities, and GR, which has excellent physical, chemical, rigid, and spectral properties. CTS and GR composites can be used to create hydrogels, aerogels, scaffolds, films, and nanofibers. The efficiency of CTS/GR composite material in different shapes may be increased even more by including various multifunctional polymeric materials, nano-sized-particles, or proliferation factors due to the ease with which these nanocomposites can be functionalized. Through this context in mind, this chapter describes the most recent discoveries in CTS/GR composites in various forms and compositions in drug delivery applications such as mouth, nostril, eye, oral, lung, sublingual, skin, and anal drug delivery. Future directions for improvement and obstacles for healthcare are also presented.

This study provides foundational research for the domestic development of hydrogen refueling station components by conducting coupled fluid–structure interaction analysis and experiments to evaluate the structural safety of existing hydrogen refueling nozzles. Using fluid-induced pressure as boundary conditions, the analysis assessed equivalent stresses and deformations and derived safety factors based on the yield strength of materials. While the majority of components were found to be structurally safe, a poppet-like component exhibited maximum equivalent stress and structural instability. This was validated by a pressure cycling test conducted according to ISO 19880-3, which revealed damage consistent with the analysis results. Therefore, modifications to the internal flow path of the poppet-like component are necessary.

Vibriosis caused by Vibrio anguillarum has been an important bacterial disease in cultured rainbow trout (Oncorhynchus mykiss). In the present study, we evaluated the protective efficacy of a vaccine that consists of formalin-killed (FK) V. anguillarum and the alr genes knockout auxotrophic-live (AL) V. anguillarum (Δalr1Δalr2 V. anguillarum). Fish were immunized with a high dose of the FK V. anguillarum vaccine or four different combinations of FK and AL V. anguillarum. In the challenge test, fish immunized with 1 × 10⁶ CFU of FK V. anguillarum plus 1 × 10⁴ CFU of AL V. anguillarum (FK-10⁶ + AL-10⁴) showed complete protection (100% RPS) against V. anguillarum. In comparison, fish immunized with 1 × 10⁷ CFU of FK V. anguillarum (FK-10⁷) showed much lower survival rates. In the result of ELISA, the antibody titer of fish immunized with FK-10⁶ + AL-10⁴ was significantly higher than that of the PBS group, but the titer was not higher than FK-10⁷, suggesting that the higher protection by the FK + AL combination vaccine might be mediated by not only humoral immunity but also other protective factors conferred by live bacteria in the combination vaccine. In conclusion, the present FK + AL combination vaccine efficiently protected rainbow trout with approximately 10 times lower doses of bacteria than FK-10⁷, which could lessen the safety problem caused by a high-tittered live bacteria vaccine and the lower immunogenicity problem of killed bacteria vaccine.

Rainfall infiltration analysis has a significant effect on landslide assessment. The investigation of the input parameters of infiltration analysis is limited on the large scale. Therefore, an infiltration analysis using Monte Carlo simulation was proposed to deal with the uncertainty of the input parameters in the infiltration computation process. A sensitivity analysis was performed to assess the contribution of each parameter. Then, the proposed model was applied to Saka town, Hiroshima Prefecture, Japan. The landslide probability map was also computed to validate the proposed model using inventory from 2018 landslides. The results show that both curvature and porosity are the most sensitive, followed by hydraulic conductivity and slope. These parameters were stochastically included when calculating the saturated depth on the large scale. The saturated depth map with and without uncertainty consideration was compared. The results illustrate that the maximum saturated depth at each rainfall duration considering uncertainty is less than without uncertainty consideration. The area under the receiver operating characteristic curve (AUC) was used to validate the landslide probability map. The result indicates the proposed model is fair, with an AUC of 73.8%, while AUC is 70.7% for model without uncertainty consideration. The proposed approach may be utilized to analyze rainfall infiltration-induced landslides in the future.

All-solid-state lithium metal batteries adopting polymer-, oxide-, and sulfide-based solid electrolytes have drawn significant interest due to their potential for enhanced energy density and non-flammable characteristics. Each type of solid electrolyte offers distinct benefits, such as the mechanical flexibility of polymer electrolytes, the thermal stability of oxide electrolytes, and the high ionic conductivity of sulfide electrolytes. However, the unstable interface between metallic Li anode and solid electrolytes remains a major obstacle, leading to issues like dendritic Li growth, increased interfacial resistance, and solid electrolyte degradation. To address these challenges, various strategies focusing on interfacial engineering have been implemented, achieving notable improvements in overall battery performance. This review focuses on strategies to stabilize the interface for each type of electrolyte, detailing principles and key effects of these approaches. In addition, the remaining challenges required for the commercialization of all-solid-state lithium metal batteries are briefly discussed.

This paper presents phase diagrams for Portland cement-slag-fly ash ternary cements. The study investigates various binder combinations of Portland cement, slag and fly ash, ranging from 30–100, 0–50 and 0–50, respectively. The thermodynamic equilibrium of given ternary cement systems was simulated using thermodynamic modeling coupled with simulated degree of reaction of slag and fly ash that vary with the binder compositions. The obtained results suggest that a 56% substitution factor for supplementary cementitious materials is feasible without significantly altering the formation of C–(A)–S–H. Additionally, it is found that ettringite and straetlingite are stable in the same cementitious material combinations, but ettringite becomes unstable in mixtures that favor monosulfate formation. Overall, this study provides a catalogue for selecting an appropriate proportion of binders to create mixes that complement one another, providing characteristics that are specifically tailored to the application. The results may have important implications for designing and optimizing ternary cement compositions.

The effects of the two popular strategies, scapular adduction and depression and scapular posterior tilt, on muscle activity of the trapezius and serratus anterior muscles have not been compared. This study demonstrates the effects of additional scapular adduction and depression or scapular posterior tilt movements on the activation of trapezius and serratus anterior muscles and scapular kinematics during arm raising. Eighteen asymptomatic men performed arm raising tasks with and without additional scapular movements, including scapular adduction and depression or scapular posterior tilt. During all tasks, muscle activity of the upper/middle/lower trapezius and serratus anterior were measured using surface electromyography; scapular upward rotation and posterior tilt angles were measured using a smartphone application. Lower trapezius muscle activity significantly increased during arm raising with scapular adduction and depression (p=0.001) or scapular posterior tilt compared to preferred arm raising (p<0.001). However, arm raising with scapular posterior tilt showed significantly greater serratus anterior muscle activity (p=0.002) and scapular posterior tilt angle (p=0.001) together with lesser upper trapezius muscle activity (p=0.027) compared with those of scapular adduction and depression. Scapular posterior tilt may be effective for increasing lower trapezius and serratus anterior muscle activity while reducing upper trapezius muscle activity.