Daegu Gyeongbuk Institute of Science and Technology
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REGENERATIVE PERIPHERAL NERVE INTERFACE AND MANUFACTURING METHOD THEREOF
No full text재생 말초신경 인터페이스 및 그 제조방법이 개시된다. 이 중에서 재생 말초신경 인터페이스는 말초신경으로부터 신경 신호를 획득하는 신경 전극과, 근육조직으로부터 근육 신호를 획득하는 근육 전극과, 신경 전극 및 근육 전극을 회로 단자에 전기적으로 연결하기 위한 채널 전극과, 신경 전극, 근육 전극 및 채널 전극의 적어도 일부를 감싸는 형상기억폴리머를 포함할 수 있다
Edge-Plane-Selective Formation of Mn Vacancies in β-Na0.7MnO2+y for Air-Stable Cathode Materials in Sodium-Ion Batteries
No full textManganese-based P2-type NaxMnO2+y, particularly β-Na0.7MnO2+y, exhibit high reversible capacity but are prone to stability issues, especially hydration-induced degradation when exposed to air. Herein, a significant improvement in the air stability of β-Na0.7MnO2+y cathodes is achieved through a selective transition of their edge planes to α-Na0.7MnO2+z. When β-Na0.7MnO2+y particles are oxidized at a relatively low temperature (350 °C), oxygen is selectively inserted at the edge planes due to the higher energy barrier for oxygen insertion at the basal planes compared with the edge planes. This mild oxidation selectively locally creates manganese vacancies near the edge plane surface, promoting the exclusive formation of α-Na0.7MnO2+z on the edge surface. The α-Na0.7MnO2+z nanolayers on the edge planes effectively suppress H2O insertion during air exposure, eventually mitigating the phase transition of β-Na0.7MnO2+y to NaγMnO2·δH2O birnessite during storage. Moreover, this plane-selective formation of α-Na0.7MnO2+z enhances the electrochemical performance of β-Na0.7MnO2+y, such as stable capacity retention. © 2025 American Chemical Society.FALSEsciescopu
Addressing Fundamental Challenges of Si/Gr Electrodes with High Silicon Contents Using Innovative Bilayer Electrode Structure Design
No full textThe extremely high volume change of Si during alloying and dealloying in the charge/discharge process is a key challenge for increasing the Si content in Si/Gr electrodes. To address these fundamental challenges, a sophisticated bilayer Si/Gr electrode composed of an upper layer with a porous structure and a lower layer with a compact structure to increase the Si content while enhancing the long-term cycling stability of the electrode is designed. The unique structure of the bilayer Si/Gr electrode is achieved by controlling the densities of the upper and lower electrode layers. The porous structure of the upper layer can accommodate the volume expansion of Si, thereby increasing the Si content of the Si/Gr electrode. The compact structure of the lower layer can suppress the delamination of the electrode by the volume expansion of Si due to its high binding strength with the current collector, thus ensuring the long-term stability of the Si/Gr electrode. Consequently, because of the distinct features of the upper and lower layers in the bilayer Si/Gr electrode, superior cyclability is achieved despite an increase in the total Si content to 30 wt% in the Si/Gr electrode, with a specific capacity of 534.8 mAh g−1 after 100 cycles. © 2024 The Author(s). Small Structures published by Wiley-VCH GmbH.TRUEsciescopu
APPARATUS AND METHOD FOR EVALUATING RED BLOOD CELLS BASED ON DEEP-LEARNING
No full text본 개시의 일 실시 예에 따른 적혈구 평가 방법은 각 단계의 적어도 일부가 프로세서에 의해 수행되는 방법으로서, 각 단계의 적어도 일부가 프로세서에 의해 수행되는 방법으로서, 적혈구의 위상 이미지를 제공 받는 단계, 위상 이미지를 컨벌루션 레이어에 기반한 추론 모델에 입력하여 적혈구의 마커 이미지 및 적혈구 분류 이미지를 획득하는 단계 및 적혈구 분류 이미지에 기반하여 생성한 적혈구의 바이너리 마스크 이미지와 마커 이미지에 마커 기반 워터쉐드(watershed) 알고리듬을 적용하여 적혈구의 영역을 구분한 세그먼테이션 정보를 생성하는 단계를 포함할 수 있다
Nucleation-Controlled Doping of II–VI Semiconductor Nanocrystals Mediated by Magic-Sized Clusters
Full text linkDoping quantum-confined semiconductor nanocrystals offers an effective way to tailor their unique properties. However, the inherent challenges of nanoscale doping processes, such as the low probability of successful doping, have hindered their practical applications. Nucleation-controlled doping has emerged as a potential solution, but a comprehensive mechanistic understanding of this process is lacking. Herein, the nucleation-controlled doping process facilitated by magic-sized cluster intermediates is elucidated. This approach enables the synthesis of 2D ZnSe quantum nanoribbons with two distinct doping sites. Remarkably, the identity of the dopants plays a critical role in determining the chemical pathways of nucleation-controlled doping. Substitutional doping of magic-sized clusters with Mn2+ ions leads to successful substitutional doping of the final 2D nanocrystals. Conversely, Co2+ ions, initially occupying substitutional positions in the magic-sized cluster intermediates, relocate to alternative sites, such as interstitial sites, in the final nanocrystals. First-principle calculations of dopant formation energies support these experimental findings, demonstrating the thermodynamic favorability of specific dopant site preferences. Moreover, a consistent tendency is observed in CdSe nanocrystals, suggesting that the proposed doping mechanism is generally applicable to II–VI semiconductors. This study will advance the controlled synthesis of various doped semiconductor nanocrystals using nucleation-controlled doping processes. © 2024 The Author(s). Small Science published by Wiley-VCH GmbH.TRUEscopu
Ion-Beam-Induced Biaxial Tensile Strain Engineering in Nanoscale Zinc Oxide Films on Silicon Dioxide
Full text linkStrain engineering is a powerful tool for adjusting the electrical and optical properties of materials, particularly in 2D materials on flexible polymer substrates. However, current strain-engineering techniques are primarily utilized for thin 2D materials on flexible substrates, with limited research on thicker materials on traditional substrates. In this study, the enhancement in electrical properties resulting from strain effects in 30-nm-thick ZnO films deposited on SiO2 wafers through N2 ion beam irradiation is proposed. The N2 ion beam, at an optimal energy level, induces strain in the underlying SiO2 layer, leading to a 2.5-fold increase in the saturation mobility and charge-carrier density of the overlying ZnO film. Density functional theory calculations reveal that the introduction of N2 molecules into the SiO2 crystal induces biaxial lattice expansion, which, in turn, strains the overlying ZnO film. These findings demonstrate the effective application of strain engineering in films of relatively large thickness, even on traditional substrates. It is anticipated that this strain engineering approach using ion-beam irradiation will significantly broaden the range of applications for strain engineering technology. © 2024 The Author(s). Advanced Functional Materials published by Wiley-VCH GmbH.TRUEsciescopu
Supramolecular Reconstruction of Self-Assembling Photosensitizers for Enhanced Photocatalytic Hydrogen Evolution
No full textNatural photosynthetic systems require spatiotemporal organization to optimize photosensitized reactions and maintain overall efficiency, involving the hierarchical self-assembly of photosynthetic components and their stabilization through synergistic interactions. However, replicating this level of organization is challenging due to the difficulty in efficiently communicating supramolecular nano-assemblies with nanoparticles or biological architectures, owing to their dynamic instability. Herein, we demonstrate that the supramolecular reconstruction of self-assembled amphiphilic rhodamine B nanospheres (RN) through treatment with metal-phenolic coordination complexes results in the formation of a stable hybrid structure. This reconstructed structure enhances electron transfer efficiency, leading to improved photocatalytic performance. Due to the photoluminescence quenching property of RN and its electronic synergy with tannic acid (T) and zirconium (Z), the supramolecular complexes of hybrid nanospheres (RNTxZy) with Pt nanoparticles or a biological workhorse, Shewanella oneidensis MR-1, showed marked improvement in photocatalytic hydrogen production. The supramolecular hybrid particles with a metal-phenolic coordination layer showed 5.6- and 4.0-fold increases, respectively, in the productivities of hydrogen evolution catalyzed by Pt (Pt/RNTxZy) and MR-1 (M/RNTxZy), respectively. These results highlight the potential for further advancements in the structural and photochemical control of supramolecular nanomaterials for energy harvesting and bio-hybrid systems. © 2024 Wiley-VCH GmbH.FALSEsciescopu
Relaxation of the Jahn–Teller stress effect in the P3-type K0.5MnO2 cathode by copper and magnesium co-substitution for high-performance K-ion batteries
No full textThe Mn-based P3-type layered oxide (K0.5MnO2) is a promising cathode material for K-ion batteries (KIBs) because of its low cost, high specific capacity, and simple synthesis. However, it suffers from severe capacity loss and sluggish K+ diffusion kinetics, which are mainly attributed to multiple phase transitions and the Jahn–Teller distortion of Mn3+. To address these challenges, herein, the Mg and Cu co-substitution strategy is proposed to synthesize the P3-type K0.5Mn0.8Mg0.1Cu0.1O2 (P3-KMMCO) as a cathode for KIBs. The presence of divalent Mg2+ and Cu2+ in the crystal structure of P3-KMMCO play the critical functions in regulating the Jahn–Teller-active Mn3+, thereby suppressing the complex phase transitions and improving the K+ diffusion kinetics during charging and discharging. As a result, the P3-KMMCO cathode demonstrates the high reversible capacity, outstanding cycling stability and power capability. A combination study of synchrotron-based X-ray analysis and first-principles calculations is used to validate the enhanced electrochemical K+ storage properties of the P3-KMMCO cathode. © 2024FALSEsciescopu
Surface Composition Impacts Selectivity of ZnTe Photocathodes in Photoelectrochemical CO2 Reduction Reaction
Full text linkLight-driven reduction of CO2 into chemicals using a photoelectrochemical (PEC) approach is considered as a promising way to meet the carbon neutral target. The very top surface of the photoelectrode and semiconductor/electrolyte interface plays a pivotal role in defining the performance for PEC CO2 reduction. However, such impact remains poorly understood. Here, we report an electrodeposition-annealing route for tailoring surface composition of ZnTe photocathodes. Our work demonstrates that a Zn-rich surface on the ZnTe photocathode is essential to impact the CO2 reduction activity and selectivity. In particular, the Zn-rich surface not only facilitated the interfacial charge carrier transfer, but also acted as electrocatalyst for boosting carbon product selectivity and suppressing the hydrogen evolution reaction. This work provides a new avenue to optimize the photocathode, as well as improvement of the CO2RR performance. © 2024 The Authors. Published by American Chemical Society.TRUEsciescopu
APPARATUS AND METHOD FOR MEASURING PULSE TRANSIT TIME
No full text맥파 전달 시간 측정 장치는 초광대역 레이더로부터 사용자의 흉부에 투사되어 반사된 레이더 신호를 수신하는 레이더 신호 수신부, 상기 레이더 신호를 기초로 상기 흉부의 제1 심박파형을 검출하는 제1 심박파형 검출부, 사용자 손목에 착용된 스마트 손목밴드로부터 측정된 사용자의 손목의 제2 심박파형을 수신하는 제2 심박파형 수신부 및 상기 제1 심박파형 및 상기 제2 심박파형을 기초로 맥파 전달 시간을 검출하는 맥파 전달 시간 검출부를 포함한다