Experimental Verification for Practical Application of Inductive Power Transfer System for Railway

Inductive Power Transfer systems (IPT systems) for moving Electrical Vehicles (EVs) are often discussed. However, an IPT system for moving railway vehicles has not been sufficiently examined. In order to employ the IPT system for railway vehicles, this paper examines the characteristics of railway IPT systems, such as efficiency, temperature rise, and durability. Because the required characteristics of the IPT system for railway are different from those of EV, one example of a railway IPT system is proposed, and the verification items for practical use are examined. Moreover, we manufactured test equipment that can imitate the field environment in order to verify these items before practical use in the field. The test procedure and test results demonstrate the possibility of practical use of a railway IPT system.     

Study of the composition and structure of ion-conducting membranes based on polyvinyl alcohol by 1H NMR spectroscopy

One of the alternative types of proton-conducting membranes for a hydrogen-air solid polymer fuel cell is the type of hybrid membranes based on polyvinyl alcohol (PVA) crosslinked with aldehyde, modified by sulfonic acid. Earlier, for the first time, we obtained new ion – conducting membranes based on furfural-crosslinked PVA modified aminosulfonic acid (ASA) and tetraethoxysilane (TEOS), as well as membranes not crosslinked with furfural (FUR) or unmodified ASA and TEOS, by a liquid-phase synthesis method, in an organic medium-dimethyl sulfoxide. The values of their ionic conductivity and the degree of swelling in water are presented. In this work, the composition and structure of the obtained ion-conducting membranes are studied using liquid-phase nuclear magnetic resonance (NMR) spectroscopy on ¹H nuclei. In the ¹H NMR spectrum of an ion – conducting membrane not cross-linked with the «PVA/ASA», the signal of free OH groups of PVA is observed to disappear, but at the same time a characteristic triplet at 7.1 ppm. is preserved, having a constant of ～51 Hz and components of the same intensity (1:1:1), which corresponds to protons of ¹⁴NH₄⁺ hydrolyzed ASA. The disappearance of the expanded signal at 9.6 m. d. of protons of the free sulfo group of ASA and a narrow singlet signal at 5.8 m. d. of free protons of the NH₂ group of ASA indicates the interaction of ASA with OH groups of PVA. In the ¹H NMR spectrum of an ion – conducting membrane crosslinked with FUR – «PVA/ASA/FUR», signals of protons of the furan ring of FUR and a signal of its aldehyde group are observed, which is shifted to a strong field, which is determined by the formation of a chemical bond between FUR and the polymer chain of PVA. In the ¹H NMR spectra of all membranes modified by ASA, the appearance of a second weaker-field ¹⁴NH₄⁺ triplet is observed, and in the spectra of a number of ion – conducting hybrid membranes modified by TEOS – «PVA/ASA/FUR/TEOS», signals of the third type of ¹⁴NH₄⁺ triplets shifted in a strong field relative to the other two ¹⁴NH₄⁺ triplets were detected. The appearance of additional ¹⁴NH₄⁺ triplets indicates the formation of several bound forms of the ammonium ion.     

Iron oxide-Palladium core-shell nanospheres for ferromagnetic resonance-based hydrogen gas sensing

Interfaces of ferromagnetic transition metals such as Iron, Cobalt, and Nickel with non-magnetic palladium are of interest due to their unique magnetic and spintronic properties. These interfaces enable ferromagnetic resonance (FMR) based sensing of hydrogen gas. In the present work, we synthesized Fe₃O₄–Pd core-shell nanospheres via a one-pot synthesis method using the thermal decomposition of Fe³⁺ acetylacetonate in the presence of a reducing agent to produce the Fe₃O₄ core, followed by the reduction of a Pd²⁺ precursor to form the pure Pd shell. We found that our in-situ synthesized core-shell nanostructure is magnetically active and shows excellent H₂ gas sensing properties. The effect of reversible hydrogen gas absorption on the magnetism of Fe₃O₄–Pd core-shell nanospheres was investigated. The hydrogen-induced ferromagnetic-resonance (FMR) peak shift amounted to 30% of the peak linewidth for the virgin state of the sample. In addition, in the presence of hydrogen gas, we observed a fully reversible decrease in the FMR peak linewidth by about two times. This was accompanied by a nearly doubling of the FMR peak height. Response and recovery times of about 2 and 50 s, respectively, were extracted from the measurements. All the data was collected using a mix of just 3% hydrogen in a nitrogen carrier gas.     

Prediction models for the cross-sectional areas of lower lumbar intervertebral discs and vertebral endplates

Current approaches to obtain lumbar morphometry data usually require expensive medical imaging technology, long processing time, and are often limited by small sample size. This study develops regression models for the cross-sectional areas (CSAs) of the lower lumbar (i.e., from L3/L4 to L5/S1 level) intervertebral discs (IVDs) and vertebral endplates (EPs) using both simple and complex anthropometric variables. CSAs were measured using OsiriX^© software, based on 3T magnetic resonance imaging (MRI) scans from a sample of 13 females and 22 males, aged between 20 and 40, and asymptomatic of low back disorders. Comprehensive body anthropometry data were collected and included in the regression analyses. Several multiple regression models were developed with varying levels of complexity. Subject stature, elbow dimensions, and ankle dimensions were statistically significant predictors for the CSAs of IVDs and EPs. Gender exhibited a more predictive relationship with the CSAs when compared to body weight and age. In general, regression models using newly proposed best subset procedure resulted in smaller prediction errors, compared to the models using easy-to-measure variables (i.e., gender, age, height, and weight). However, simple regression models are still worthy of investigation given the low cost, ease of data collection, and satisfactory model performance.     

All thermal-evaporated surface plasmon enhanced organic solar cells by Au nanoparticles

Au nanoparticles (NPs) are fabricated on indium-tin-oxide substrates by a thermal evaporation method and incorporated to an efficient small molecule organic solar cell (OSC). This renders an all thermal evaporated surface plasmon enhanced OSC. The optimized device shows a power conversion efficiency of 3.40%, which is 14% higher than that of the reference device without Au NPs. The improvement is mainly contributed to the increased short-circuit current which resulted from the enhanced light harvesting due to localized surface plasmon resonance of Au NPs and the increased conductivity of the device.     

大规模光伏并网系统谐振机理及稳定性分析

在弱电网下或者装机容量增加时,大规模光伏并网系统易引发谐波谐振,危及光伏电站的正常稳定运行。针对上述问题,以大规模光伏并网系统为研究对象,分别从系统阻尼、闭环控制等角度揭示了大型光伏电站和电网之间的谐振机理。研究结果表明:LCL滤波器自身的有源阻尼策略并不会导致大规模光伏并网系统引发谐振,引发谐振的关键因素在于并网逆变器自身的稳定裕度。电网阻抗、装机容量、系统参数设计、控制策略等因素的综合效应可以使并网逆变器在某一特定条件下运行到临界稳定状态附近而引发谐振,谐振将导致入网电流在相应谐振频段产生大量谐波。如果稳定裕度进一步减小,系统将逐步由谐振状态过渡到振荡、发散等不稳定状态。仿真与实验结果验证了理论分析的正确性。     

Characterisation and in vitro cytotoxicity of toxic and degradation compounds in bamboo shoots (Dendrocalamus Sinicus) during traditional fermentation

Fermentation has been historically applied to reduce bamboo shoot (BS) toxicity. However, the underlying degradation pathway of the toxic compounds remains unknown. In this work, the cytotoxicity of BS against the BRL-3A cells was evaluated, and the changes in chemical constituents were determined to reveal the influence of fermentation on BS. The in vitro toxic evaluation revealed fermentation time was crucial in decreasing the toxicity. The main compounds in fresh and fermented were qualitatively and quantitatively determined and were further targeted isolated and identified. A mathematical model to describe the change rate as a function of fermentation time was formulated. Dynamic profiling revealed that taxiphyllin 1 , p-hydroxybenzaldehyde 2 and methyl-p-hydroxybenzoate 3 decreased and transformed into intermediate compounds (p-hydroxybenzoic acid 4 and p-hydroxybenzyl alcohol 5 ), finally converting into p-hydroxytoluene 6 during fermentation. The results provided basis on the chemical components for practical fermentation and the quality control of BS products.     

Effect of Axial Slit on Metallic Tube for Wireless Power Transfer via Magnetic Resonance Coupling

Wireless power transfer using a metallic tube with an axial slit was attempted to demonstrate the wireless power transfer using magnetic resonance coupling to the diagnostics infrastructure. The transmission efficiency with variable distance was measured using the transmission and receiver resonators in the tube. Besides, the transmission and receiver resonators were, respectively, set outside and inside the tube. These experiments are carried out in the computational study using FDTD method.