Fast Li+ Transport via Silica Network-Driven Nanochannels in Ionomer-in-Framework for Lithium Metal Batteries

For the development of all-solid-state lithium metal batteries (LMBs), a high-porous silica aerogel (SA)-reinforced single-Li⁺ conducting nanocomposite polymer electrolyte (NPE) is prepared via two-step selective functionalization. The mesoporous SA is introduced as a mechanical framework for NPE as well as a channel for fast lithium cation migration. Two types of monomers containing weak-binding imide anions and Li⁺ cations are synthesized and used to prepare NPEs, where these monomers are grafted in SA to produce SA-based NPEs (SANPEs) as ionomer-in-framework. This hybrid SANPE exhibits high ionic conductivities (≈10⁻³ S cm⁻¹), high modulus (≈10⁵ Pa), high lithium transference number (0.84), and wide electrochemical window (>4.8 V). The resultant SANPE in the lithium symmetric cell possesses long-term cyclic stability without short-circuiting over 800 h under 0.2 mA cm⁻². Furthermore, the LiFePO₄|SANPE|Li solid-state batteries present a high discharge capacity of 167 mAh g⁻¹ at 0.1 C, good rate capability up to 1 C, wide operating temperatures (from −10 to 40 °C), and a stable cycling performance with 97% capacity retention and 100% coulombic efficiency after 75 cycles at 1 C and 25 °C. The SANPE demonstrates a new design principle for solid-state electrolytes, allowing for a perfect complex between inorganic silica and organic polymer, for high-energy-density LMBs.     

Adaptive wire bow-tie antenna for GPR applications

In this paper, the basic design of an adaptive ground penetrating radar antenna is introduced. The antenna is able to adapt its input impedance to a variation in the antenna elevation and soil type to keep reflections at the antenna's terminal minimum. As a result, energy transfer from the generator to the antenna is maximized, which in turn maximizes the energy radiated by the antenna into the ground for different antenna elevations and soil types. The antenna is based on a wire bow-tie structure with variable flare angle for adjusting the antenna's input impedance. The flare angle variation is realized by short-circuiting the gaps separating the wires from the feed point of the antenna, for which electronic switching devices such as PIN diodes could be used to allow fast and convenient control of the antenna's flare angle.     

Analysis and Design of Improved Antennas for GPR

In this paper a concept of adaptive antennas for ground penetrating radar is introduced. It is demonstrated that antenna adaptation with respect to the antenna feed-point reflection can be achieved for different ground types. This adaptation can be realized using a wire bow-tie antenna with variable flare angle. By varying the flare angle, a minimal feed-point reflection can be obtained for different types of ground. Moreover, the shape and size of the footprint of the bow-tie antenna can be adjusted by changing the flare angle for improving detection/imaging. Furthermore, a novel loading scheme based on a combination of a capacitive and resistive loading is introduced, and applied on a solid bow-tie antenna. It is shown that using this loading scheme an efficient ultra-wideband antenna for ground penetrating radar applications can be realized.     

Catalytic Deoxygenation of Stearic Acid and Palmitic Acid in Semibatch Mode

The deoxygenation experiments of different reactants, i.e., pure palmitic acid, stearic acid, and a technical grade stearic acid containing a mixture of 59% of palmitic and 40% of stearic acid were successfully performed over 4 wt% Pd/C mesoporous catalyst at 300 °C under 17 bar of 5% H₂ in argon. The main product in catalytic deoxygenation of saturated fatty acids, C16 and C18, were aliphatic chain length hydrocarbons containing one less carbon than the corresponding acid. Additionally it was found that the deoxygenation rates of different reactant were independent on carbon chain length of its fatty acids.     

RC-loaded bow-tie antenna for improved pulse radiation

In this paper, a loading technique for improving pulse radiation from bow-tie antennas is introduced. This technique allows transmission of short transient pulses with very small late-time ringing and relatively high radiation efficiency. It makes use of a combination of a constant resistive loading along the antenna and a capacitive loading with linearly increasing reactance toward the antenna ends. The constant resistive loading is applied using volumetric microwave absorbers to cover one side of the antenna and the linear capacitive loading is realized by constructing narrow slots on the antenna surface. Relatively high radiation efficiency is achieved by choosing the location of the slot nearest to the feed point in such a way that radiation from it combines constructively with radiation from the feed point. Using a 0.8-ns monocycle for excitation, the technique results in a level of late-time ringing of lower than -40 dB and at the same time the peak value of the transmitted pulse is 54% higher than that of the same antenna without loading.     

基于形态损伤监测的复合层板弯曲模型

迫切需要研究有效的技术进行结构的健康监测,提高复合结构的安全性和完整性。研究的主要目的是,采用灵敏的压电材料和现代仪器如扫描激光振动计(SLV),以评估基于动力学的复合层板损伤探测技术。采用两个不同的驱动传感器系统测试一个嵌层的E-玻璃/环氧复合板,两个传感器分别为:1)带有PZT(铅-锆酸盐-钛酸盐)调节器的扫描激光振动计(PZT-SLV);2)带有PZT调节器的聚偏二乙烯氟化物(PVDF)传感器。同时进行了有限元分析以补充损伤探测。试验和数值弯曲模型被用于探测剥离的发生、位置和尺寸。采用三种相对新的损伤探测算法(即简化裂隙平滑方法,广义不规则维数方法及应变能方法)分析试验和数值弯曲模型数据以及均荷表面的曲率。损伤探测成果证实PZT-SLV系统更便利和有效,能够扫描到整个试件的大部分点;可直接获得弯曲模型的PZT-PVDF系统,该系统显示对损伤具有良好敏感性。基于三个模式连续利用的GSM,GFD和SEM损伤探测算法及由此引出的ULS曲率,可以成功识别组合板中剥离的发生、位置和相对尺寸。     

Numerical and experimental analysis of circular-end wire bow-tie antennas over a lossy ground

This paper presents a numerical and experimental analysis of a wire bow-tie antenna situated horizontally near a lossy ground. The antenna is basically an array of identical wire dipoles having a common feed point and equal angular separation between two neighboring wires. This antenna is particularly suitable for ultrawide-band applications as it possesses a wideband property and allows a simple realization of resistive loading. It also provides a possibility to easily vary the antenna flare angle for the purpose of antenna matching or to adjust its footprint. In this work a theoretical model of the antenna is developed and verified experimentally. The wires are modeled as a tape-like structure by triangular patches and the antenna is analyzed using a mixed-potential integral equation formulation. Moreover, time-domain solutions are computed using the Fourier transformation, and a time-window technique is employed to calculate the antenna characteristic impedance. Using the model a comprehensive analysis of the antenna performance is carried out.     

An alternative method for fire smoke toxicity assessment using human lung cells

An alternative method for fire smoke toxicity testing using human lung cells has been investigated. A laboratory-scale vertical tube furnace was used for the generation of combustion products. Experiments were conducted under isothermal oxidative non-flaming conditions. A range of building and train interiors including polyethylene (PE), polypropylene (PP), polycarbonate (PC), polyvinyl chloride (PVC), fiberglass reinforced polymer (FRP), and melamine-faced plywood (MFP) were studied. The exposure of combustion toxicants to human lung cells (A549) at the air/liquid interface was acquired using a Harvard Navicyte Chamber. Cytotoxic effects on human cells were assessed based on cell viability using the MTS assay (Promega). Cytotoxicity results were expressed as NOAEC (No Observable Adverse Effect Concentration), IC₁₀ (10% inhibitory concentration), IC₅₀ (50% inhibitory concentration) and total lethal concentration (TLC) values (mg/L). These cytotoxicity results were compared to published combustion toxicity data. Mass loss data and toxic product yield were also determined. The following toxicity ranking was observed from the most toxic to the least toxic: PVC>PE>PP> FRP-10>PC> FRP-16>MFP. The method described here could potentially be an alternative to current fire toxicity standard test methods.