Nichia Corporation (Japan)

This study investigates the application of the Nd2Fe17N3 compound with planar magnetocrystalline anisotropy as an electromagnetic wave absorber in the gigahertz (GHz) band. We measured the complex permeabilities of two sheets prepared using single-phase Nd2Fe17N3 powders with particle sizes of 3 and 9 μm, which were synthesized through the reduction-diffusion process using the free-space method from 1 to 330 GHz. We discovered a positive imaginary part of complex permeability (μ″) over an extremely wide bandwidth from 1 to 330 GHz and beyond, which was not observed in other materials. To investigate the factors causing μ″ to be positive over this broad high frequency range, we estimated the natural resonance frequency from the saturation magnetization (Ms) and magnetocrystalline anisotropy fields (μ0Ha1 and μ0Ha2) measurement, in combination with magnetic domain pattern observation. We estimated Ms, μ0Ha1, and μ0Ha2 to be 1.73, 0.14, and 17 T, respectively. The natural resonance frequency calculated from these results was 43–166 GHz. Therefore, we speculate that resonance phenomena in Nd2Fe17N3 at frequencies exceeding 166 GHz arise from mechanisms other than natural resonance.

Alternating irradiation of red and blue light has been reported to promote the growth of several crops, caused by modifications in metabolite biosynthesis. In this study, ten Spinacia accessions, including both cultivated and wild spinach, were grown under alternating and simultaneous red/blue light irradiation, with a white fluorescent lamp used as a control. The results indicated that alternating red and blue light significantly increased fresh weight of most accessions. Additionally, alternating irradiation enhanced accumulation of glutamic acid, glutamine, and aspartic acid. In contrast, the levels of gamma-aminobutyric acid (GABA) and asparagine significantly decreased under alternating red and blue light, while they reached their highest values under simultaneous irradiation. The results suggest that different irradiation regimes influence plant growth by modulating enzyme activity in metabolic processes, leading to the accumulation or depletion of specific amino acids. Among the tested accessions, ‘CGN25120’ exhibited the highest increase in fresh weight when subjected to alternating irradiation, showing a remarkable improvement of 100.3% compared to fluorescent irradiation. Similarly, ‘CGN09511’ experienced a 153.1% increase in fresh weight without a significant reduction in amino acid content. Meanwhile, the wild accession ‘CGN25085’ ( Spinacia tetrandra ) demonstrated exceptionally high amino acid content, suggesting it could be a valuable genetic resource for plant breeding. • Alternating red/blue light significantly enhanced fresh weight in most spinach accessions. • Glutamic acid, glutamine, and aspartic acid accumulated more under alternating light. • Simultaneous red/blue irradiation increased GABA and asparagine levels, showing a contrasting metabolic response. • Hybrid accessions ‘CGN25120’ and ‘CGN14215’ showed strong adaptability to alternating light, making them ideal for plant factories. • Wild accession ‘CGN25085’ ( Spinacia tetrandra ) exhibited high amino acid content, highlighting its breeding potential.

Mobility electrification has been increasing the use of copper in motors, batteries, and other key electric components. This has led to an increased demand for copper processing. Copper has a high optical absorption coefficient in the blue wavelength range. Therefore, a blue laser is a promising candidate as a light source for copper processing due to its high energy efficiency. We have been developing high-power blue laser diode (LD) modules. This module is a fiber-coupled direct diode laser using the techniques of spatial combining and polarization beam combining. We previously reported on the development of an LD module which achieved an output power of over 500W from an optical fiber with a 110μm core diameter. An increase in the number of installed LDs and the output power of each LD helped achieve this high optical output power. To realize high-quality and high-efficiency copper processing and expand the applications of blue laser processing, we have been continuously making progress in the development of high-power blue LD modules. In this paper, we have made further design improvements of both the LDs and the LD module to increase the output power of the LD module. As a result, we have achieved an output power of more than 800W at a 110μm core size. This developed LD module has a brightness of more than 8.4MW/cm² and a BPP of 8.8mm-mrad.

This paper presents an evaluation of the characteristics of an interior permanent magnet synchronous motor (IPMSM) with Sm-Fe-N bonded magnets directly injection molded into the rotor core. Finite element method (FEM) calculations confirmed that the proposed IPMSM achieves torque characteristics that are approximately 93% of those of an IPMSM using Nd-Fe-B sintered magnets. A prototype rotor was then fabricated by injection molding Sm-Fe-N bonded magnets into the rotor core, and the motor characteristics were evaluated through actual measurements. The back EMF of the prototype motor was found to be in good agreement with the FEM calculations. Furthermore, measurements of the current phase angle versus torque characteristics of the prototype motor showed that the measured torque values closely matched the calculated values, demonstrating that the motor was fabricated as designed and confirming the validity of the proposed motor.

Visible-wavelength GaN-based photonic-crystal surface-emitting lasers (PCSELs) have attracted attention for various applications, such as materials processing, high-brightness illuminations, and displays. In this letter, we demonstrate GaN-based PCSELs at green wavelengths. We formed a photonic crystal (PC) in p-GaN and filled holes of the PC with SiO2 to ensure device stability. Through a current injection test under pulsed conditions and spectral analysis, we confirmed that the fabricated device possessed Γ-point single-mode oscillation at wavelengths above 505 nm. Our results have the potential to further expand the applications of PCSELs and semiconductor lasers in visible region.

Magneto-optical (MO) effect-based devices, such as spatial light modulators and optical isolators, have become increasingly prevalent in the fields of optical communication and information processing because of their high-speed response. However, conventional MO devices (e.g., Terbium Gallium Garnet crystals) have poor transparency in the visible range and polarization rotation capability, which constrains the integration of small optical systems. Recently, a silicon carbide spatial light modulator (SiC-SLM) (depicted in Fig. 1(a)) was developed via dressed-photon-phonon (DPP)-assisted annealing of 4H-SiC crystals doped with aluminum atoms [1]. This device exhibited an extremely large MO effect in the visible range, as evidenced by a Verdet constant of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$9.51\times 10^{4}\text{rad}/\mathrm{T}\bullet \mathrm{m}$</tex> near its absorption edge at 457 nm. There are many unknown aspects such as the spatial distribution of the degree of polarization rotation, optimal annealing conditions, and geometrical conditions of the electrode. In this study, the utilization of the SiC-SLM for spectral filtering of imaging technology and the photophysical properties of the SiC-SLM device, especially the phase delay by birefringence, were investigated, and this progress promises a new SLM application.

We synthesized soft magnetic Fe-X powders with different Ni compositions (Ni = 0, 2.2, 4.4, 6.7, and 8.8 at%) on a 1 kg batch scale and investigated the effect of Ni content on their magnetic properties. The coercivity increases as the Ni content decreased. The saturation magnetization was maximum for a Ni content of 4.4 at%. The magnetic properties of the Fe-X powder synthesized in this study on a mass production scale achieved a coercivity of 0.77 Oe and a saturation magnetization of approximately 222 emu/g at a composition of 0.1 at% Mn and 2.2 at% Ni content.

A robot gripper for correction work has been developed to automate rework of frozen foods and other food products. It is not known in advance which part of a food product needs to be reworked. Therefore, we developed a gripper that can rotate the gripped food in two directions in the hand so that the surface to be reworked can be found by rotating the gripped food in various directions.

Due to global population growth and economic development in emerging countries, worldwide meat demand is increasing. While, livestock farming poses various problems, meat alternatives are attracting increasing attention. There are signs that soy meat is becoming especially popular in Japan, reflecting its long cultural familiarity with soybean-based foods and making it a potential model for the promotion of meat alternatives. This study explored Japanese consumers’ motivators related to eating soy meat using logistic regression analysis to reveal a possible key to expanding the market. The results indicate that enhanced food neophilia, environmental consciousness, convenience, and sensory appeal lead to an increase in the frequency with which soy meat is eaten. Among these factors, convenience and sensory appeal can be managed by food companies. Thus, we expect that the market is likely to grow if food companies promote the convenience and sensory appeal of soy meat to Japanese consumers.

Binder-free carbon cloth (CC) cathodes with tunable porosity prepared from Kynol 1500 by CO2 activation at 900 °C with the specific surface area up to 3170 m2g-1 and pore volume up to 2.05 cc g−1 have been tested in Li–S battery prototypes with catholyte solutions containing Li2S8. The capacity of CCs normalized to carbon mass is linearly proportional to the surface area and pore volume values. Capacities of CC cathodes were compared to the capacity of a composite mesoporous carbon (MPC) cathode prepared from MPC powder with PVdF binder and tested in identical conditions as sulfur host. The results indicate that pore volume of the carbon hosts is a key factor which determines the capacity of Li–S cells with lithium polysulfide catholyte solution. The effect of the surface area and pore volume of carbon cathodes on capacity and cycling performance is discussed. The possibility of attaining of a practical level of the areal capacity of 3.4 mAh cm−2 is demonstrated for the activated CC with maximal pore volume. SEM analysis of CC cathodes after prolonged cycling reveals signs of degradation of the carbon fibers' structure. The results of XPS analysis of the surface of the cycled Li anodes is discussed.