Tuning local chemistry of P2 layered-oxide cathode for high energy and long cycles of sodium-ion battery

Layered transition-metal oxides have attracted intensive interest for cathode materials of sodium-ion batteries. However, they are hindered by the limited capacity and inferior phase transition due to the gliding of transition-metal layers upon Na+ extraction and insertion in the cathode materials. Here, we report that the large-sized K+ is riveted in the prismatic Na+ sites of P2-Na0.612K0.056MnO2 to enable more thermodynamically favorable Na+ vacancies. The Mn-O bonds are reinforced to reduce phase transition during charge and discharge. 0.901 Na+ per formula are reversibly extracted and inserted, in which only the two-phase transition of P2 ↔ P’2 occurs at low voltages. It exhibits the highest specific capacity of 240.5 mAh g−1 and energy density of 654 Wh kg−1 based on the redox of Mn3+/Mn4+, and a capacity retention of 98.2% after 100 cycles. This investigation will shed lights on the tuneable chemical environments of transition-metal oxides for advanced cathode materials and promote the development of sodium-ion batteries

Modeling and Analysis of an Energy-Efficient Mobility Management Scheme in IP-Based Wireless Networks†

An energy-efficient mobility management scheme in IP-based wireless networks is proposed to reduce the battery power consumption of mobile hosts (MHs). The proposed scheme manages seven MH states, including transmitting, receiving, attention/cell-connected, attention/paging area(PA)-connected, idle, off/attached, and detached states, to efficiently manage battery power, radio resources, and network load. We derive the stationary probabilities and steady state probabilities of the seven MH states for the proposed scheme in IP-based wireless networks in compact form. The effects of various input parameters on MH steady state probabilities and power consumption are investigated in the proposed scheme compared to the conventional scheme. Network costs such as cell updates, PA updates, binding-lifetime-based registrations, and paging messages are analyzed in the proposed and conventional schemes. The optimal values of PA size and registration interval are derived to minimize the network cost of the proposed scheme. The combined network and power costs are investigated for the proposed and conventional schemes. The results provide guidelines to select the proper system parameters in IP-based wireless networks

Music Source Separation Using ASPP Based on Coupled U-Net Model

Noise has established itself as one of the factors that interfere with modern human life, and various noise canceling techniques have been studied to prevent noise. While the old era's noise-canceling technique focused on the physical soundproofing technique, multiple studies have been conducted on the active noise canceling technique that removes only the activated noise in the current era. Active noise canceling (ANC) or digital noise-canceling technology is based on the sound source separation method. This leads to sound source separation technology, which refers to the technology to separate individual sound signals from mixture sounds. Most of the source separation technologies focus on improving speech, not noise reduction. This technology makes it possible to obtain desired sound information more accurately and further improves noise-canceling technology by eliminating unwanted sound information. To provide deeper capability and more enhanced sound separation than the existing structure, we are focused on coupled U-Net model and Atrous spatial pyramid pooling technique (ASPP). This paper presents the music source separation method that combined Coupled U-Net structure with Atrous spatial pyramid pooling technique. To prove the proposed source separation method, we compared GNSDR, GSIR, and GSAR using MIR-1K, a data set that can evaluate the performance of the music source separation. Performance results show that the proposed source separation method overcame other methods' disadvantages and strengthened the feature map

Wave Absorption Property of High Entropy Alloy Fabricated by Sol-Gel Process

In this study, the magnetic properties and wave absorption characteristics of high entropy alloys are investigated. The high entropy alloys with FeNiMnCoCu, FeNiMnZnCo, and FeNiZnCoCu compositions were synthesized by the sol-gel method. After the sol-gel process, the annealing process and hydrogen reduction process was performed. FeNiMnCoCu and FeNiZnCoCu were revealed soft magnetic property. The saturation magnetization was 12 emu/g and 36 emu/g, respectively. And The coercive force was –45 Oe and –34 Oe, respectively. The high entropy alloy with these compositions was revealed wave absorption property at above 10 gigahertz frequency region. And it has shown the trend that wave absorption frequency has decreased with the sample thickness increasing

Potential Prebiotic and Anti-Obesity Effects of Codium fragile Extract

Polysaccharides from marine algae exhibit beneficial biological activities. In this study, we examined the effect of Codium fragile extract (CFE) on prebiotic and anti-obesity activity through in vitro experiments. CFE increases the growth of specific beneficial microbial populations with concomitant decrease in pathogenic microbes. Further, total phenolic content (TPC), total flavonoid content (TFC), and DPPH radical scavenging activity (DPPH activity) after fermentation with CFE as the carbon source were higher than for glucose as the control. Moreover, CFE inhibited adipocyte differentiation by inducing differentiation-related factors when the induction of 3T3-L1 preadipocytes into adipocytes was induced. Therefore, we suggest that CFE can be used as a prebiotic material with an anti-obesity effect for human health

Effect of Polyvinylpolypyrrolidone Surfactant on Characteristics of Iron-Oxide Nanoparticles Synthesized by Using Recycled Waste Permanent Magnets

In this study, iron oxide nanoparticles (FeOx NPs) were synthesized by using Fe solution recycled from NdFeB permanent magnet scrap. Furthermore, the effect of polyvinylpolypyrrolidone (PVP) as a surfactant on the characteristics of the FeOx NPs was investigated. Firstly, Fe solution was prepared by using 10% H2SO4 solution and Na2SO4 salt. In addition, three reducing agent solutions were prepared by dissolving PVP in 0.5 M NH4OH solution in distilled (D.I.) water with concentrations of 0 wt%, 1 wt%, and 2 wt%, respectively. Each reducing agent solution was added dropwise into the Fe solution to precipitate three precursors of FeOx NPs, and they were heat-treated at 400 °C to prepare three FeOx NPs samples, P0, P1, and P2. In X-ray diffractometer (XRD) analysis, diffraction peaks of P0 sample are consistent with the Fe3O4 with (311) preferred orientation. The XRD peak shifted from Fe3O4 to Fe2O3 structure as PVP concentration increased, and the crystal structure of P2 sample was transformed to Fe2O3 with (104) preferred orientation. Brunauer, Emmett, and Teller (BET) specific surface area increased in proportional to PVP concentration. HRTEM observation also supported the tendency; the particle size of the P0 sample was less than 40 nm, and particle size decreased as PVP concentration increased, leading to the particle size of the P2 sample being less than 20 nm in width. In addition, particle morphology started to be transformed from particle to rod shape as PVP concentration increased and, in the P2 sample, all the morphology of particles was transformed to a rod shape. Magnetic properties analysis revealed that the P0 sample exhibited the highest value of magnetic moment, 65.6 emu/g, and the magnetic moment was lowered in the P1 sample, and the P2 sample exhibited the lowest value of magnetic moment, 2.4 emu/g

Self-adhesive polyurethane via selective photo-polymerization for biocompatible epidermal soft sensor and thermal heater

Polyurethane (PU) is the most extensively used soft backbone substrate for wearable applications. However, even with biocompatibility and stretchability, PU-based wearable devices are unsuitable for epidermal devices because they lack of adhesive properties. To impart adhesive properties to PU, commercial adhesive additives are required or the mixing ratio of specific materials should be adjusted. Despite PU biocompatibility, additional additives cause skin damage because they are not usually biocompatible due to their toxic ingredient. This study introduces a simple method of fabricating self-adhesive polyurethane (SAPU) without specific adhesive additives for a biocompatible epidermal soft sensor and an attachable epidermal thermal heater. During the selective photo-polymerization of PU resin, the defective crosslinking networks between laser-scanned resin lines enhance the adhesive properties of PU. Adjusting photopolymerization conditions results in self-adhesive polyurethane with high adhesiveness and low Young's modulus comparable to those of human skin. A mouse skin toxicity test confirms the biocompatibility and highly conformal contact of SAPU. SAPU is then further applied for the fabrication of a biocompatible epidermal soft sensor and an attachable epidermal thermal heater with silver nanowire network. The fabricated self-adhesive epidermal soft sensor successfully detects human motion and bio-signals, whereas the self-adhesive epidermal soft heater efficiently transfers heat to the epidermis due to its excellent conformal contact characteristics on the human skin. (c) 2022ElsevierLtd. Allrightsreserved

Reproducible Polybutylene Succinate (PBS)-Degrading Artificial Consortia by Introducing the Least Type of PBS-Degrading Strains

Polybutylene succinate (PBS) stands out as a promising biodegradable polymer, drawing attention for its potential as an eco-friendly alternative to traditional plastics due to its biodegradability and reduced environmental impact. In this study, we aimed to enhance PBS degradation by examining artificial consortia composed of bacterial strains. Specifically, Terribacillus sp. JY49, Bacillus sp. JY35, and Bacillus sp. NR4 were assessed for their capabilities and synergistic effects in PBS degradation. When only two types of strains, Bacillus sp. JY35 and Bacillus sp. NR4, were co-cultured as a consortium, a notable increase in degradation activity toward PBS was observed compared to their activities alone. The consortium of Bacillus sp. JY35 and Bacillus sp. NR4 demonstrated a remarkable degradation yield of 76.5% in PBS after 10 days. The degradation of PBS by the consortium was validated and our findings underscore the potential for enhancing PBS degradation and the possibility of fast degradation by forming artificial consortia, leveraging the synergy between strains with limited PBS degradation activity. Furthermore, this study demonstrated that utilizing only two types of strains in the consortium facilitates easy control and provides reproducible results. This approach mitigates the risk of losing activity and reproducibility issues often associated with natural consortia

Oxygen Activities Governing Structural Reversibility in Industrial Ni-Rich Layered Cathodes

The chemical reactions and phase transitions at high voltages determine the electrochemical properties of high voltage layered cathodes such as Ni-rich rhombohedral materials. Here, we performed a comprehensive and comparative study of the cationic and anionic redox reactions, as well as the structural evolution of a series of industrial Ni-rich layered cathode materials with and without Al doping, which are being utilized in the cells made by LG Energy Solutions Co.. We combined the results from X-ray spectroscopy, operando electrochemical mass spectrometry, and neutron diffraction with electrochemical properties, and revealed the different oxygen activities associated with structural and electrochemical degradations. We show that Al doping suppresses the irreversible oxygen release thereby enhancing the reversible lattice oxygen redox resulting from the interplay between static (doped Al) and dynamic disorders (reversible oxygen redox). With this modulated oxygen activity, the Ni-rich cathode\u27s notorious H2-H3 structural phase transition becomes highly reversible. Our findings disentangle the different oxygen activities during high-voltage cycling and clarify the role of dopants in the Ni-rich layered cathodes in terms of structural and electrochemical stability finally making all the cell makers get back to the fundamental investigation regarding whether high-Ni NCM chemistry (NCM811 or NCM 91/2 1/2) is substantially beneficial compared to its mid-Ni homologues (NCM622)