ShinEtsu Chemical (Japan)

Sixth-generation (6G) wireless communication systems impose stringent requirements on antenna performance, including ultra-high data rates, ultra-lowlatency, massive connectivity, high-frequency operation, advanced beamforming, and long-term reliability. Achieving these goals at mm-wave and sub-terahertz frequencies introduces major challenges such as severe path loss, hardware complexity, thermal stress, limited flexibility, and performance degradation under mechanical and environmental variations. This review presents a comprehensive overview of 6G antenna requirements, key antenna technologies, material platforms, fabrication techniques, AI/ML integration, and reliability assessment. Advanced antenna solutions, including hybrid antenna arrays, antenna collocation, metasurfaces and reconfigurable intelligent surfaces, and mm-wave and terahertz antennas are discussed alongside their limitations in flexibility and robustness. Flexible antennas are highlighted as a promising solution, enabled by emerging materials and additive fabrication methods such as inkjet printing, aerosol jet printing, screen printing, and additive manufacturing. In addition, standardized testing and reliability evaluation under harsh environments, such as bending, thermal cycling, humidity, and aging are reviewed. Finally, the integration of artificial intelligence and machine learning for antenna design optimization, fabrication control, and performance enhancement is discussed, outlining future directions for reliable and scalable 6G antenna systems.

AlGaN-based far-ultraviolet C light-emitting diodes (far-UVC LEDs) and ultravioletB (UVB) LEDs have a wide range of applications to kill viruses and bacteria, and a large market is expected. However, the efficiency of far-UVC LEDs is still much lower than that of blue LEDs due to the quite low light-extraction efficiency (LEE) and hole injection efficiency. We investigated the influence of Al-compositionally graded Mg-doped multi-quantum-barrier electron-blocking-layer (Al graded p-MQB EBL) and Al-compositionally graded Mg-doped p-AlGaN hole injection layer (HIL) on the carrier injection toward the active region of UVB LED. The external quantum efficiency (EQE) of the world record 10 % and light output power of 42 mW on bare-wafer under continuouswave operation at room temperature in the absence of standard package, flip-chip, and resin-like lenses are achieved. These improvements are attributed to the use of transparent Al -graded Mg doped p-AlGaN HIL and p-MQB EBL structure for hole transport toward the multi-quantum wells via intra-band tunneling mechanisms. Using Al-graded p-MQB EBL coupled with softly polarized p-AlGaN HIL and the highly reflective 0.4 nm -thick Ni and 200 nm -thick Al p-electrode in the UVB LED were combined effect on EQE. In the case of AlGaN-based far-UVC emission, the influence of the n -AlGaN buffer layer's growth temperature on its relaxation and electrical properties in <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$228{-}$</tex> 230 nm far-UVC LED is also investigated. Quite a low contact resistivity (<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\rho_{c}$</tex>) of 0.05Ω - <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{cm}^{2}$</tex> on the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{n}-\text{AlGaN}$</tex> contact layer was also achieved. The low relaxation ratio is critical for the suppression of transverse magnetic (TM)-mode as well as for promoting transverse electric (TE)-mode emission (along the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$c$</tex>-axis). Finally, the power and EQE were significantly improved to a record value of 2.2 mW and 0.42 % under pulse operation and 1.4 mW and 0.41 % under CW operation on wafer at RT. This is the highest value of EQE in far-UVC LED grown on c-Sapphire.

Taking up Virginia Woolf’s paradigmatic motto “we think back through our mothers if we are women” (Woolf 2015, 57), and bringing Woolf’s thinking into dialogue with contemporary writers, critics, and thinkers, this essay examines the various modes of transmission and reception the motto encapsulates and connects with. Following Erica Delsandro’s article entitled “No More Missed Connections” (2019) and her invitation to read “both forward and backward through feminist history and women’s texts” (90) and to “lean into a feminist historicity in which networks trump icons, in which history flows backward as well as forward, and in which we think through our daughters as much as we do our mothers” (91-92), I explore the constellation-like and paradoxically non-linear modalities of non-patrilineal and feminist transmission that have been conceived in dialogue with and/or through Woolf’s paradigm of “thinking back through our mothers.” Delving into various rethinkings of the mother-daughter dyad, both in its biological, symbolic, and metaphorical senses, I unravel a non-fixed and plural mother-daughter matrix by addressing the following literary and feminist issues: debunking the pro/creation myth, kaleidoscoping and pluralising the mother, unsilencing long lost (fore)mothers, subjectifying (inter)textuality and reclaiming feminine influence, queering matrilineal transmission and reception.

In this study, aiming at developing anti-washout grout for repairing marine structures, experimental investigations were conducted regarding a mix proportion design of grout with high fluidity, which satisfies specifications for anti-washout admixture applied to concrete. As a result, it was possible to present the mix proportion which almost satisfies the specified values in pH, turbidity and strength ratio of specimens made in water and air by means of repeating the prototype.

All-solid-state sodium batteries are attracting intensive attention, and chloride-based solid electrolytes are promising candidates for use in such batteries because of their high chemical stability and low Young's modulus. Here, we report new superionic conductors based on polyanion-added chloride-based materials. Na0.67 Zr(SO4 )0.33 Cl4 showed a high ionic conductivity of 1.6 mS cm-1 at room temperature. X-ray diffraction analysis indicated that the highly conducting materials are mainly a mixture of an amorphous phase and Na2 ZrCl6 . The conductivity might be dominated by the electronegativity of the central atom of the polyanion. Electrochemical measurements reveal that Na0.67 Zr(SO4 )0.33 Cl4 is a sodium ionic conductor and is suitable for use as a solid electrolyte in all-solid-state sodium batteries.

Two-dimensional magnonic crystals (2D MCs) for forward volume spin waves were designed using the finite integration technique. The calculated model consisted of a 170 mm × 170 mm × 0.6 mm substrate with two microstrip lines (MSLs), and a 15 mm × 15 mm × 10 μm yttrium iron garnet (YIG) film placed on top of the MSLs. The 2D MCs consisted of Cu dots with a diameter of 300 μm and a thickness of 1 μm periodically located on the YIG film. Two types of periodic structures, a square configuration and a hexagonal configuration, were fabricated. The reflected spin waves from the edge of the YIG film were suppressed by placing 30-nm thick Au films, and a magnonic bandgap of 2D MCs was observed. In addition, the shift of the magnonic bandgap was obtained when the incident angles of spin waves to 2D MCs were varied.

Previous studies have found that implicit attitudes, in addition to explicit attitudes, toward sports and exercise can help predict health-related behaviors. This study aimed to explore the factors that determine implicit attitudes toward sports and exercise. Using an online experiment, we investigated two types of implicit attitudes toward sports and exercise: desirability and enjoyment. Implicit attitudes toward sports and exercise were measured using two different Implicit Association Test (IAT) for desirability and for joy. We examined the degree to which “sports and exercise” were perceived to be more strongly associated with positive words than “sedentary behaviors.” We hypothesized that past experiences with sports and exercise affect implicit attitudes, and that desirability and enjoyment (positive implicit attitudes) might differ qualitatively. Participants included 318 students (230 male and 88 female, M = 19.62, SD = 1.78) who completed online questionnaires consisting of one of the two types of IAT. The results indicated that male participants have more positive implicit attitudes for both joy and desirability, and people with sports competence tend to have higher positive implicit attitudes concerning joy, but not desirability. Interest in professional sports was related to both IATs, while only the joy IAT was related to self-reported physical competence and the frequency of playing sports. The contributions of this study show that the two types of implicit attitudes toward sports and exercise—desirability and joy—are associated with different behaviors, and perceiving sports and exercise as joyful leads people to lifelong sports participation.

Incorporating appropriate amount of movable cross-links in poly(dimethyl siloxane) (PDMS) resulted in simultanous improvement of Young's modulus and toughness.

Alkoxysilanes are important precursors of silicone materials for which various synthesis methods have been reported. However, these approaches are not without problems, and hence, halogen-free, HF-free, and room-temperature reactions producing alkoxysilanes are required. In this study, we demonstrated a direct low-temperature (∼40 °C) alkoxysilane synthesis method that did not involve halogens or HF. Si, Cu, and ethanol were milled in a planetary ball mill for 2 h, and a 50% yield of tetraethoxysilane (TEOS) was obtained; in addition, analysis revealed negligible contamination (<50 ppm) and a TEOS purity of 99.9%. Gas-, liquid-, and solid-phase mechanochemical products were identified. The alkoxysilane yield depended significantly on the mechanochemical pre-treatment, and seven transition metals were investigated as catalysts. Specifically, mechanochemical pre-treatment of a Si–Cu mixture produced silicide (Cu3Si), which was responsible for the high yields. The alkoxysilane yields and silicide formation mechanism were examined by calculating the local temperature upon impact between colliding balls. We also observed high-volume H2 production and demonstrated that the stainless-steel milling medium acted as a mechanocatalyst. Thus, a near-room-temperature, halogen-free green one-pot synthesis method, involving milling Si and Cu powders in alcohol, was discovered and demonstrated as a novel strategy for high-purity alkoxysilane and H2 production.