Nagaoka University

A downflow hanging sponge (DHS) reactor’s performances were evaluated under varying organic loading rates (OLRs) and hydraulic retention times (HRTs) with/without effluent recirculation, using high-strength industrial wastewater. The experiment was conducted for 389 days at 30°C in four main phases. In phase 1, the OLR was increased from 1.5 to 9.7 kg· chemical oxygen demand (COD) m-³·day −1 while HRT decreased from 14.4 to 2.9 h. In Phase 2, half of the sponges were removed, doubling the volumetric OLR. In Phase 3, four sponges were reintroduced (OLR = 6.86 kg· COD m-³·day −1 , HRT = 2.1 h), and in Phase 4, OLR was reduced to 3.77 kg·COD m⁻³·day⁻¹with an HRT of 4.3 h. The organic matter removal was inversely related to the OLR. In the recirculation reactor (R2), the total biochemical oxygen demand (tBOD) and tCOD removals decreased from 87-75% (Phase 1) to 50% (Phase 2). The tCOD removal increased in Phase 4 and reached 74%. NH 4 + -N removal followed a similar pattern, declining from 97% (Phase 1) to 38% (Phase 2) and then recovering to 77% (Phase 4). The R2 demonstrated a higher removal rate, with 85% tBOD and 58% total nitrogen (TN) removal, compared to the R1 (without recirculation) results of 80% tBOD and 52% TN removal. Comamonadaceae and Rhodocyclaceae were prominent in the sponges, though the nitrite-oxidizing bacteria were low. Effluent recirculation significantly enhances nitrogen removal (~20%), while organic matter removal improvements were condition-specific. Recirculation improved oxygen transfer and created favorable conditions for microbes, making the DHS system effective for high-strength organic wastewater treatment. • Organic removal declined at extreme OLRs but recovered at moderate loading. • Recirculation achieved 85% tBOD and 58% TN removal, outperforming the control. • Denitrifying bacteria dominated; low NOB limited complete nitrification. • Recirculation significantly enhanced ammonia removal, but low impact on organic removal

Summary: The 2018 Western Japan floods resulted in numerous fatalities among elderly residents, with many cases of “drowning at home” reported. This study analyzes victim characteristics to explore mitigation strategies for a society experiencing increasing climate-related disasters. We collected cases of home drowning fatalities during the floods in Ehime and Okayama Prefectures through media reports (newspapers and television) and analyzed survival patterns. In Ehime Prefecture, 9 (29.1%) of 32 victims drowned, with 3 (9.7%) drowning at home. All three were over 70 and found on the first floor. In Okayama’s Mabi town, 43 (84.3%) of 51 drowning victims died at home, with 36 (70.6%) being elderly (65+). 42 died on the first floor, one on the second floor. Both prefectures reported cases where surviving elderly residents reached the second floor but failed to convince their spouses to follow, resulting in spouse fatalities. In one case, an elderly couple survived by floating on their bed, which rose with the water level near the ceiling. In Ehime, a family successfully rescued a one-year-old girl and her great-grandmother using a two-seater sofa as flotation. Swimming while clothed is challenging, particularly for elderly individuals with reduced physical strength. Given that most elderly victims drowned on the first floor, the survival probability could increase through flotation strategies. When external evacuation risks are high during indoor flooding, back float and improvised flotation devices (life jackets, coolers, sealed backpacks with clothing) may contribute to survival. This survival technique, internationally known as “Uitemate” (Float and Wait), effectively prevents drowning in various flood disasters and represents a household-level disaster risk reduction strategy.

Chemotherapy-induced nausea and vomiting (CINV) remain major challenges during concurrent chemoradiotherapy (CCRT) for cervical cancer. Mannitol and furosemide are agents widely used to prevent cisplatin-induced nephrotoxicity; however, the differences in their effect on CINV have not been characterized. This study aimed to evaluate the impact of concomitant diuretic administration (mannitol versus furosemide) on the incidence and timing of vomiting in patients with cervical cancer undergoing CCRT. This multicenter, retrospective study evaluated the impact of concomitant diuretic administration on CINV in 485 patients receiving weekly, cisplatin-based CCRT between 2016 and 2024, including 206 who received mannitol and 279 who received furosemide. Vomiting occurred more frequently in the mannitol group than in the furosemide group (18.4% vs. 10.4%). Time-to-event analysis found that vomiting occurred earlier with mannitol during the entire CCRT course. These findings may reflect mannitol's osmotic properties and the increased, intestinal permeability associated with CCRT-related mucosal injury. To the best of our knowledge, this study is the largest investigation to date comparing diuretic agents in this setting. The results suggested that furosemide may be a more appropriate option for patients with a high risk of CINV.

Four optically active dodecen-4-olides (1a-d) with carbon-carbon double bonds at different positions and their cyclopropanated derivatives (2a-d) were synthesized, and the odour characteristics of the racemic and optically active compounds were evaluated. Compounds 1a-d and 2a-d exhibited typical lactone-like nuances, characterized by strong top notes and oily middle notes. The position of the carbon-carbon double bond had a significant effect on the odour profile. All 1a-d compounds exhibited different odour characteristics: 1a showed fruity notes, 1b and 1c exhibited green and fruity notes, and 1d exhibited green and floral notes. Cyclopropanation substantially altered these characteristics. As a result, the odour characteristics of compounds 2, where the carbon-carbon double bonds were converted to cyclopropane rings, differed significantly from those of compounds 1. Conversion of the double bond in 1a to a cyclopropane ring changed the fruity note to green note, while cyclopropanation of 1b changed the green note to fruity. The antimicrobial activities of 1 and 2 against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were also investigated. Only compound (S)-1b exhibited antimicrobial activity against S. aureus.

In this study, a novel rotor structure for V-shaped interior permanent magnet (IPM) motors was proposed. V-shaped magnet arrangement enables the generation of concentrated magnetic flux on the d-axis, resulting in a high torque density. However, reducing the leakage flux generated in the outer bridge was an important design issue. In the proposed motor, trapezoidal magnets were inserted into the rotor core instead of conventional rectangular ones. By gradually narrowing the width of the magnets in the radial direction, the magnets can be supported by the rotor core without outer bridges. In this study, numerical verification was performed to verify its effectiveness. The numerical verification confirmed that the volume of magnets required to obtain the desired torque was reduced by 10.2% compared with that of conventional V-shaped IPM motors. In addition, a prototype was used to demonstrate the effectiveness of numerical verification. It was anticipated that the positional variation of the magnets in the rotor core would be a problem with this structure; however, during prototype production, it was demonstrated that this issue could be resolved by using a jig to fix the magnet position.

3-Monochloropropane-1,2-diol (3-MCPD) esters and glycidyl esters (GE) are process-induced contaminants formed primarily during the high-temperature refining of edible vegetable oils.Increasing regulatory scrutiny and toxicological concerns have made their control a critical challenge for the edible oil industry.This study examines the chemical pathways responsible for the formation of 3-MCPD and glycidyl esters during key refining stages, including degumming, bleaching, and deodorization.The influence of process variables such as temperature, residence time, chloride sources, diacylglycerol content, and the nature of bleaching earth is discussed.Analytical approaches used for the detection and quantification of these contaminants, including gas chromatography and liquid chromatography-mass spectrometry techniques, are briefly reviewed.Furthermore, practical mitigation strategies such as optimization of deodorization conditions, selection of low-chloride raw materials, modification of bleaching practices, and pre-treatment techniques for reducing precursor compounds are evaluated.The findings highlight that preventive process control is more effective than post-refining removal strategies.This paper provides a comprehensive overview of formation mechanisms and industrially feasible mitigation approaches, contributing to improved refining practices and enhanced food safety compliance.

Purpose This study examines how international experiences, both academic and work-based, contribute to the development of global citizenship in engineering students, hypothesizing that each plays a distinct yet complementary role in fostering professional and personal growth. Design/methodology/approach A structured questionnaire was administered to a sample of Mexican engineering students participating in the GIGAKU Global Project – an international program blending academic learning with work-based experiences. The data were analyzed using SPSS to assess the impact on key competence areas. Findings Results indicate that students experienced the greatest development in non-technical skills, followed by attitudinal and technical competencies. Notably, enhanced areas included research skills, learning to learn, collaboration, analytical thinking, global awareness, social responsibility and personal engagement. Research limitations/implications The study's findings are constrained by a small sample limited to Mexican engineering students, which may affect generalizability. Emphasizing European and global frameworks may also limit applicability to other contexts. Broader, comparative studies are recommended. Practical implications The findings offer practical guidance for embedding global competence and sustainability in engineering curricula, informing course design, accreditation and institutional policy. Social implications This research promotes the formation of socially responsible engineers capable of addressing global challenges through inclusive, ethical and sustainable solutions. Originality/value This study presents an original synthesis of global citizenship education (GCE) within engineering by integrating sustainability goals, work-based learning and competency frameworks. It connects conceptual models with applied practices, offering fresh insights into developing globally competent engineers.

This paper proposes an enhanced distributed control scheme with power imbalance compensation for an Input-ParallelOutput-Parallel (IPOP) AC-DC converter featuring a power imbalance compensator that incorporates non-instantaneous values. Power-sharing imbalances are a common issue in parallelconnected cell converters due to wiring resistance between the load and individual cells under conventional droop control. The proposed compensator, placed in the outer loop of the voltage and current feedback loops, effectively mitigates these imbalances. By leveraging non-instantaneous values, the control scheme accepts low-bandwidth communication, enabling the use of low-speed wireless modules and reducing the required signal lines, thus enhancing system flexibility. The experimental validation is conducted using a 7.2-kW prototype comprising six cells with integrated wireless communication modules. The results demonstrate that the proposed method reduces output current imbalance by up to 94% compared to conventional approaches.