Nagaoka University of Technology

Building-integrated photovoltaics (BIPVs) require both high power conversion performance and an aesthetically acceptable appearance, particularly near-white façades that are widely used in architecture. However, conventional whitening methods based on surface-textured glass or highly scattered pigment layers can cause considerable optical losses. In this study, we proposed a scattering layer using nanosized smectite clay and investigated its potential for realizing near-white solar cells with reduced power loss. Organically modified smectite was dispersed in a thermoplastic acrylic resin and spin-coated onto glass to form clay films with controlled clay volume fractions. When applied to Si heterojunction (SHJ) cells, the clay films provide high haze through volume scattering, while maintaining a hemispherical transmittance close to that of flat glass, resulting in very low optical loss. In particular, a 50 vol% clay film achieved a near-white appearance comparable to that of commercial textured glass diffusers, while maintaining an optical loss below 1% with a lightness of 32. We also designed and fabricated hybrid films combining clay with dielectric multilayer films (DMFs), optimized by multi-objective Bayesian optimization. The optimized clay–DMF hybrid films achieved a lightness of approximately 60 with an optical loss of approximately 11%, exhibiting a color tone closer to white. These results demonstrate that nanoclay-based scattering layers and their hybridization with DMFs could offer a promising approach for producing near-white BIPV modules with enhanced aesthetic quality while retaining acceptable power performance. • BIPVs require high power conversion and an aesthetically acceptable appearance. • However, conventional whitening methods can cause considerable optical losses. • Hybrid films that combined nanoclay with dielectric multilayer films were studied. • 50 vol% clay film exhibited near-white appearance with optical loss <1% in SHJ cells. • Optimized clay–DMF hybrid films exhibited L∗ ≈60 at ∼11% optical loss.

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

We report image classification using a diffractive neural network based on the magneto-optical effect (MO-DNN). Diffractive neural networks (DNNs) offer unique advantages such as low power consumption, high-speed computing, and parallel processing. The incorporation of the MO effect into DNNs introduces reconfigurability, nonvolatility, and the potential for compact devices. However, the phase modulation achievable with MO materials is typically smaller than that achievable with liquid crystals. In this study, we focused on the 90° polarization rotation of diffracted light induced by the MO effect and found that an MO-DNN with a single hidden layer and a polarizer achieved 98% classification accuracy for the MNIST handwritten digit dataset. The MO-DNN was physically implemented using a bismuth, gallium-substituted garnet film as the MO medium and a thermomagnetic recording technique. Its performance was demonstrated experimentally with a classification accuracy of 83%, and task switching was achieved by rewriting the MO hidden layer. The MO-DNN demonstrates strong potential for realizing compact, reconfigurable, and energy-efficient photonic computing devices integrated with image sensors.

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.

This study examines how electroencephalography (EEG) signatures are modulated during passive movements induced by electrical muscle stimulation (EMS). Specifically, we focused on three key factors: (1) motor errors, (2) stimulus-driven attention, and (3) cognitive conditions (motor imagery and waiting). We tested how error-related neural responses are modulated by the mismatch between predictions and actual sensory inputs during motor imagery. To this end, we introduced a wrist-movement paradigm combining motor imagery with EMS. Participants either imagined wrist dorsiflexion toward visual targets or passively waited. EMS was then applied to induce passive wrist movements. EMS intensity and presentation rate were manipulated so that the magnitude of stepwise motor error (physical deviation from the target) and stimulation-driven attention varied inversely, allowing us to evaluate their respective neural effects. Event-related potential (ERP) components at approximately 700 ms reflected graded evaluation of motor error. An ERP component at approximately 300 ms was modulated primarily by EMS intensity and presentation rate, consistent with stimulus-driven attention. Mu-band suppression reflected the match between predicted and actual sensory inputs. Theta-band enhancement in the absence of motor imagery suggested increased sensory unpredictability due to the lack of internally generated predictions, whereas beta-band activity may have been related to fluctuations in state prediction. To our knowledge, the proposed motor imagery with the EMS wrist-movement paradigm is the first to investigate how (1) motor errors, (2) stimulus-driven attention, and (3) cognitive conditions shape EEG signatures during passive, electrically induced movements. Understanding how these neural signals vary with mismatch between predictions and actual sensory inputs offers valuable insights into the mechanisms of error processing and sensory prediction in the human brain.

Abstract In the presence of Al(C8H17)3 and [Ph3C][B(C6F5)4], 2-methylbenzimidazole- or phenylbis(benzimidazol-2-yl)methane-ligated nickel dichloride complexes 1 and 2, the former of which was newly synthesized in this study, were found to catalyze the homopolymerization of isoprene (Ip) and styrene (St), respectively. The stereospecificities of the produced polymers (cis-1,4-polyIp; 1: 97%, 2: 95%; isotactic (mm)-enriched-polySt; 1: 42%, 2: 45%) depend on the structures of the complexes. The 1- or 2-catalyzed copolymerization reactions of Ip with St were also investigated. The reactivity ratios between Ip and St were determined from the Fineman–Ross plots (1: rIp = 0.81, rSt = 2.04; 2: rIp = 2.07, rSt = 2.35). These results suggest that complex 1 produces predominantly random copolymers, whereas complex 2 tends to multiblock-like structures of the resultant copolymers.

Alloy films were synthesized using intense hydrogen/oxygen flame heating of an aqueous ethylenediaminetetraacetic acid (EDTA)-(Cu, Zn) (NH 4 ) 2 solution precursor. The substrate type (alumina, A5052, or Si (100)) was varied to control the thermal history. The synthesis of Cu-Zn alloy films from EDTA-(Cu, Zn) (NH 4 ) 2 solution via flame heating is highly sensitive to both the substrate type and the precursor Cu/Zn ratio. Notably, while the substrate affected film composition and oxide formation, increasing the Zn content primarily induced a structural change from dense to porous morphology, without a corresponding dramatic shift in the final alloy's Cu/Zn ratio. The core novelty lies in the synergistic combination of metal-EDTA complexes as a volatile, molecular precursor and the high-intensity, reducing atmosphere of the hydrogen/oxygen-coupled flame for in situ alloying and coating formation. This is a single-step, fast-turnaround process. • Cu-Zn ally films were synthesized on various substrates. • Thermal history was controlled by the substrates. • Changing the Cu/Zn composition ratio affected the film’s composition and morphology.