bluuebunny/crossref_metadata_2025 huggingface dataset:
The Intersection of Abortion and Criminalization: Abortion Access for People in Prisons
Authors: Paynter Martha J. , Norman Wendy V.
Published: December 2022

Most incarcerated women are of reproductive age, and more than a third of women will have an abortion during their reproductive years. Although women are the fastest growing population in Canadian prisons, no one has studied the effect of their incarceration on access to abortion services. Studies outside of Canada indicate rates of abortion are higher among people experiencing incarceration than in the general population, and that abortion access is often problematic. Although international standards for abortion care among incarcerated populations exist, there conversely appear to be no Canadian guidelines or procedures to facilitate unintended pregnancy prevention or management. Barriers to abortion care inequitably restrict people with unintended pregnancy from attaining education and employment opportunities, cause entrenchment in violent relationships, and prevent people from choosing to parent when they are ready and able. Understanding and facilitating equitable access to abortion care for incarcerated people is critical to address structural, gender-, and race-based reproductive health inequities, and to promote reproductive justice. There is an urgent need for research in this area to direct best practices in clinical care and support policies capable to ensure equal access to abortion care for incarcerated people.
Cardiac muscle cells require fibroblast co-culture to respond to mechanical cues for growth
Authors: Liebendorfer Adam
Published: December 2022

Mechanical signals, rather than paracrine signaling, help fibroblasts chaperone cardiomyocytes into organized tissue.
Frequency division multiplexing readout of a transition edge sensor bolometer array with microstrip-type electrical bias lines
Authors: Wang Q. , Khosropanah P. , van der Kuur J. , de Lange G. , Audley M. D. , Aminaei A. , Ilyas S. , Ridder M. L. , van der Linden A. J. , Bruijn M. P. , van der Tak F. , Gao J. R.
Published: December 2022

We demonstrate multiplexed readout of 43 transition edge sensor (TES) bolometers operating at 90 mK using a frequency division multiplexing (FDM) readout chain with bias frequencies ranging from 1 to 3.5 MHz and a typical frequency spacing of 32 kHz. We improve the previously reported performance of our FDM system by two important steps. First, we replace the coplanar wires with microstrip wires, which minimize the cross talk from mutual inductance. From the measured electrical cross talk (ECT) map, the ECT of all pixels is carrier leakage dominated. Only five pixels show an ECT level higher than 1%. Second, we reduce the thermal response speed of the TES detectors by a factor of 20 by increasing the heat capacity of the TES, which allows us to bias all TES detectors below 50% in transition without oscillations. We compare the current–voltage curves and noise spectra of the TESs measured in single-pixel mode and multiplexing mode. We also compare the noise equivalent power (NEP) and the saturation power of the bolometers in both modes, where 38 pixels show less than 10% difference in NEP and 5% difference in saturation power when measured in the two different modes. The measured noise spectrum is in good agreement with the simulated noise based on measured parameters from an impedance measurement, confirming that our TES is dominated by phonon noise.
Vanishing viscosity limit for concentrated vortex rings
Authors: Buttà Paolo , Cavallaro Guido , Marchioro Carlo
Published: December 2022

We study the time evolution of a viscous incompressible fluid with axial symmetry without swirl when the initial vorticity is very concentrated in N disjoint rings. We show that in a suitable joint limit, in which both the thickness of the rings and the viscosity tend to zero, the vorticity remains concentrated in N disjointed rings, each one of them performing a simple translation along the symmetry axis with constant speed.
Controlling post-impact dynamics of ferrofluid droplets with magnetic field
Authors: Zhou Jin-Xiang , Xiao Hong-Wei , Wang Ya-Ping , Khan Adnan , Niu Xiao-Dong , Wen Ming-Fu , Chen Mu-Feng , Li De-Cai , Yamaguchi Hiroshi
Published: December 2022

Preventing droplets from splashing after impacting a thin layer or liquid pool is crucial in reducing cross-contamination, the spread of pathogens, and rough surfaces in three-dimensional (3D) printing. In this article, we demonstrate that an external magnetic field can be useful to actively control the post-impact dynamics of ferrofluid droplets. A simplified lattice Boltzmann method (SLBM) is applied to simulate the flow field with lower computational cost. For the magnetic field, a self-correcting procedure is coupled with SLBM by setting a permanent magnet of desired magnetic field strength at any location of the computational domain. In this article, four different phenomena are simulated, including static contact angle, dynamic contact angle, splashing droplet on a thin layer, and falling droplet into a pool same liquid. From the first two examples, it is deduced that a vertical non-uniform magnetic field not only controls the spreading diameter and apex height but also the puffy shape appearing at droplet laterals. In examples three and four, even more intricate crown structures and wave propagation are successfully controlled with the help of a permanent magnet. It is also discovered that a magnetic field introduced at an optimal starting moment improves control and speeds up the whole procedure.
Dynamic and giant bandgap renormalization dictates the transient optical response in perovskite quantum dots
Authors: Ren Yinjuan , Huang Zhigao , Wang Yue
Published: December 2022

Transient optical response in perovskite quantum dots (QDs) has remained elusive until now, which hinders their full utilization in optoelectronics. Herein, we reveal that the bandgap renormalization (BGR) dictates the main spectral and dynamical features of transient response in CsPbBr3 QDs. By monitoring the absorption spectral evolution of the monodispersed QDs, the representative BGR is explicitly observed, giving rise to the photoinduced absorption at the higher energy side of the lowest exciton peak in transient absorption spectroscopy. The BGR gradually increases upon photoexcitation as a result of the carrier distribution dependent screening effect. We further demonstrate that the BGR arises from both Coulomb screening and phonon heating under high pump intensities in CsPbBr3 QDs. The synergistic effect leads to the giant BGR energy (ΔE > 60 meV) and the unconventional relationship of ΔE ∝ n1/2, where n is the carrier density. These findings are important for the fundamental understanding and potential applications of the emerging halide perovskite semiconductors.
High gradient off-axis coupled C-band Cu and CuAg accelerating structures
Authors: Schneider Mitchell , Dolgashev Valery , Lewellen John W. , Tantawi Sami G. , Nanni Emilio A. , Zuboraj Muhammed , Fleming Ryan , Gorelov Dmitry , Middendorf Mark , Simakov Evgenya I.
Published: December 2022

We report the high gradient testing results of two single-cell off-axis coupled standing wave accelerating structures. Two brazed standing wave off-axis coupled structures with the same geometry were tested: one made of pure copper (Cu) and one made of a copper–silver (CuAg) alloy with a silver concentration of 0.08%. A peak surface electric field of 450 MV/m was achieved in the CuAg structure for a klystron input power of 14.5 MW and a 1 μs pulse length, which was 25% higher than the peak surface electric field achieved in the Cu structure. The superb high gradient performance was achieved because of the two major optimizations in the cavity's geometry: (1) the shunt impedance of the cavity was maximized for a peak surface electric field to accelerating gradient ratio of ∼2 for a fully relativistic particle, and (2) the peak magnetic field enhancement due to the input coupler was minimized to limit pulse heating. These tests allow us to conclude that C-band accelerating structures can operate at peak fields similar to those at higher frequencies while providing a larger beam iris for improved beam transport.
Effect of inlet leakage flow on the instability in a radial vaneless diffuser
Authors: Fan M. , Dazin A. , Bois G. , Romanò F.
Published: December 2022

The internal flow structures in a vaneless diffuser of a radial pump are experimentally and numerically investigated. Numerical simulations are used for investigating the prominent features of the fluid flow in the vaneless diffuser upon a change of the flow rate and of the impeller-to-diffuser radial gap. Comparisons between experimental and numerical results on the overall pump and diffuser performances are presented and discussed. The influence of inlet diffuser leakages on the development of flow instabilities is specifically addressed, owing to the remarkable impact that a small impeller-to-diffuser radial gap can have on the diffuser flow. Highlights on the rotating instabilities in terms of stall cell number and propagation velocity at design and off-design conditions are the main focus of this study and will be investigated using the numerical and experimental results post-processed by fast Fourier transform and wavelet analysis.
Evolution characteristics of streamwise vortex of crossing shock wave/turbulent boundary layer interaction
Authors: Zhou Yong-yi , Zhao Yi-long , Wang Li-can , Yang Rui , Zhao Yu-xin , Gao Pu-yun
Published: December 2022

The streamwise vortex generated by the crossing shock wave/turbulent boundary layer interaction seriously affects the performance of the hypersonic inlet. The shock structure, vortex core, and vortex intensity in the flowfields of weak, moderate, and strong strength interaction are experimentally and numerically investigated at Mach 2.95. The evolution characteristics of the streamwise vortex are explored. The reflection and intersection of shock waves in the interaction flowfield divide the evolution process of the streamwise vortex into four stages. The typical conical vortex evolutes into two vortexes. The vortex close to the symmetric plane further evolutes into two vortexes in the weak and strong strength flowfields. A separated flow from the focus on the flat plate produces a new streamwise vortex in the strong strength flowfield. The streamwise vortex core trace is almost parallel to the symmetric plane after the pair of streamwise vortexes collide at the symmetric plane. The vorticity intensity of the streamwise vortex increases and then decreases along the flow direction, which is greatly influenced by the interaction strength.
Photosynthesis-related physiology and metabolomics responses of
Authors: Wang Yongsen , Guan Xiaojin , Liu Zongbao , Li Yi , Yu Fangming , Liu Kehui
Published: December 2022

Manganese (Mn) plays an essential role in plant growth; however, excessive Mn is toxic to plants. Polygonum lapathifolium Linn. was tested as a novel Mn-hyperaccumulating species in our previous study, but the underlying mechanisms of this hyperaccumulation are poorly understood. A hydroponic experiment with (8 mmol L−1) and without additional Mn (CK) was established to explore the possible mechanisms through the effects on photosynthesis-related physiological characteristics and metabolomics. The results showed that additional Mn increased plant biomass, photosynthesis, and stomatal conductance related to increases in the effective photochemical quantum yield of photosystem II and relative electron transport rate (P < 0.05). The results from liquid chromatography–mass spectrometry revealed 56 metabolites differentially accumulated between the plants composing these two groups. Metabolites were enriched in 20 metabolic pathways at three levels (environmental information processing, genetic information processing, and metabolism), of which five metabolic pathways were associated with significant or extremely significant changes (P < 0.05). These five enriched pathways were ABC transporters (environmental information processing), aminoacyl-tRNA biosynthesis (genetic information processing), biosynthesis of amino acids, d-arginine and d-ornithine metabolism, and arginine biosynthesis (metabolism). Flavonoids may play a key role in Mn tolerance, as they accumulated more than 490-fold, and the relationship between flavonoids and Mn tolerance needs to be studied in the future.
Structured foraging of soil predators unveils functional responses to bacterial defenses
Authors: Rossine Fernando W. , Vercelli Gabriel T. , Tarnita Corina E. , Gregor Thomas
Published: December 2022

Predators and their foraging strategies often determine ecosystem structure and function. Yet, the role of protozoan predators in microbial soil ecosystems remains elusive despite the importance of these ecosystems to global biogeochemical cycles. In particular, amoebae—the most abundant soil protozoan predator of bacteria—remineralize soil nutrients and shape the bacterial community. However, their foraging strategies and their role as microbial ecosystem engineers remain unknown. Here, we present a multiscale approach, connecting microscopic single-cell analysis and macroscopic whole ecosystem dynamics, to expose a phylogenetically widespread foraging strategy, in which an amoeba population spontaneously partitions between cells with fast, polarized movement and cells with slow, unpolarized movement. Such differentiated motion gives rise to efficient colony expansion and consumption of the bacterial substrate. From these insights, we construct a theoretical model that predicts how disturbances to amoeba growth rate and movement disrupt their predation efficiency. These disturbances correspond to distinct classes of bacterial defenses, which allows us to experimentally validate our predictions. All considered, our characterization of amoeba foraging identifies amoeba mobility, and not amoeba growth, as the core determinant of predation efficiency and a key target for bacterial defense systems.
Contrasting patterns of microbial dominance in the
Arabidopsis thaliana
phyllosphere
Authors: Lundberg Derek S. , de Pedro Jové Roger , Pramoj Na Ayutthaya Pratchaya , Karasov Talia L. , Shalev Or , Poersch Karin , Ding Wei , Bollmann-Giolai Anita , Bezrukov Ilja , Weigel Detlef
Published: December 2022

Sphingomonas
is one of the most abundant bacterial genera in the phyllosphere of wild
Arabidopsis thaliana
, but relative to
Pseudomonas
, the ecology of
Sphingomonas
and its interaction with plants is poorly described. We analyzed the genomic features of over 400
Sphingomonas
isolates collected from local
A. thaliana
populations, which revealed much higher intergenomic diversity than for the considerably more uniform
Pseudomonas
isolates found in the same host populations. Variation in
Sphingomonas
plasmid complements and additional genomic features suggest high adaptability of this genus, and the widespread presence of protein secretion systems hints at frequent biotic interactions. While some of the isolates showed plant-protective phenotypes in lab tests, this was a rare trait. To begin to understand the extent of strain sharing across alternate hosts, we employed amplicon sequencing and a bulk-culturing metagenomics approach on both
A. thaliana
and neighboring plants. Our data reveal that both
Sphingomonas
and
Pseudomonas
thrive on other diverse plant hosts, but that
Sphingomonas
is a poor competitor in dying or dead leaves.
Rapid in situ wetting measurement for nanosolder by electron beam irradiation
Authors: Zhang Xuan , Zhang Wei
Published: December 2022

In nanosoldering, the wettability of nanosolder is a key factor to gauge the contacts’ firmness. Here, a novel in situ wetting measurement method by using electron beam irradiation in transmission electron microscopy has been proposed, which has the crucial advantages of dynamically observing the wetting process between nanosolder and nanomaterial to be soldered, rapidly measuring the contact angle, and greatly avoiding the complex procedures in traditional method. The experimental tests show that the contact angle of a reflowed 97Sn3Cu nanosolder drop on a WO3 nanowire obtained by the new method is consistent with that obtained by the traditional method. This novel wetting measurement method is aimed at promoting the application of nanosolders in nanosoldering.
Parameter choices for sparse regularization with the
ℓ1
norm
*
Authors: Liu Qianru , Wang Rui , Xu Yuesheng , Yan Mingsong
Published: December 2022

We consider a regularization problem whose objective function consists of a convex fidelity term and a regularization term determined by the

ℓ
1

norm composed with a linear transform. Empirical results show that the regularization with the

ℓ
1

norm can promote sparsity of a regularized solution. The goal of this paper is to understand theoretically the effect of the regularization parameter on the sparsity of the regularized solutions. We establish a characterization of the sparsity under the transform matrix of the solution. When the objective function is block-separable or an error bound of the regularized solution to a known function is available, the resulting characterization can be taken as a regularization parameter choice strategy with which the regularization problem has a solution having a sparsity of a certain level. When the objective function is not block-separable, we propose an iterative algorithm which simultaneously determines the regularization parameter and its corresponding solution with a prescribed sparsity level. Moreover, we study choices of the regularization parameter so that the regularization term can alleviate the ill-posedness and promote sparsity of the resulting regularized solution. Numerical experiments demonstrate that the proposed algorithm is effective and efficient, and the choices of the regularization parameters can balance the sparsity of the regularized solution and its approximation to the minimizer of the fidelity function.
Overlapping large polaron tunnelling in lanthanum silicate oxyapatite
Authors: Yadav Ashishkumar , Jha Priyanka A , Jha Pardeep K , Jha Neetu , Singh Prabhakar
Published: December 2022

Amongst the various fast ion conductors, lanthanum excess lanthanum silicate oxyapatite (La

10
−
α

(SiO4)6O

2
+
δ

) has shown higher oxide ion conductivity with lower activation energy. On the other hand, the activation energy increases with La vacancies (La at 4f site). In the present work, La site is altered with Ca to form (La

1
−
x

Ca
x
)9.67(SiO4)6O

2
+
δ

(

x
=
0.0
,
0.05
,
0.10

and 0.15) with minimum oxygen non-stoichiometry and studied the hopping/tunnelling mechanism with the Ca substitution. The elemental content obtained from Rietveld refinement of the x-ray diffractograms suggests La deficiency with minimum oxygen deficiency. Further, XPS and TGA studies confirm the formation of La deficient samples. Temperature and frequency dependent ac conductivity in the temperature range (548–973 K) suggests that the conduction takes place via overlapping large polaron tunnelling. Further, the tunnelling distance and polaron radii as a function of temperature and frequency are observed to be altered with Ca and affecting the ion conducting channel through the elongation of La(6 h) triangles. Our study suggests the phononic contribution play a pivotal role in ionic transport.
A rate-of-rise facility for measuring properties of wick structures
Authors: Elkholy A , Durfee J , Mooney J P , Robinson A J , Kempers R
Published: December 2022

This work details a mass rate-of-rise (mROR) apparatus and analysis method for the accurate and precise determination of capillary wick parameters: permeability, K, effective pore radius, r
eff, and porosity, ϵ. Three factors were examined: (a) the accuracy of the theoretical models and their curve-fitting approaches associated with the mROR technique, (b) the influence of the experimental procedure on repeatability, and (c) how the uncertainty of the experimental input parameters propagates through the data analysis procedure and compounds the overall uncertainty of the wick parameters (K and r
eff). Four models and fittings methods were investigated: the Lucas–Washburn method, the gravity-based dm/dt method, the gravity-based t–m method, and the gravity-based m–t method. It is demonstrated that the m–t method developed here shows the lowest error and, equally importantly, that it is free of user decisions in the context of ‘data scrubbing’ because the entire mROR data set is used in its raw form. To test accuracy and repeatability, a precision-controlled mROR apparatus is proposed. Experiments were performed for commercially available wicks. A robust Monte Carlo error analysis method was developed and applied to quantify the overall uncertainty in the wick parameters as a function of the input uncertainties of all measured quantities.
Bearing fault diagnosis using normalized diagnostic feature-gram and convolutional neural network
Authors: Alsalaet Jaafar K , Hajnayeb Ali , Bahedh Abdulbaseer S
Published: December 2022

Abstract

Accurate fault diagnosis is vital for modern maintenance strategies to improve machinery reliability and efficiency. Automated predictive tools, such as deep learning, are gaining more attention as the need for more general and robust diagnosis algorithms is crucial. In this work, a rotational-speed-independent diagnosis algorithm based on using a novel 2D color-coded map as the input to a deep artificial neural network is proposed. The 2D map is named normalized diagnostic feature-gram (NDFgram). The proposed algorithm is applied for bearing fault diagnosis to investigate its effectiveness. For that purpose, the bearing vibration signals are processed first to obtain the bi-frequency spectral coherence (SCoh) data. Secondly, diagnostic features (DFs) are calculated at specific cyclic frequencies owing to bearing faults by integrating the obtained SCoh data over the spectral frequency domain using a center frequency and frequency range. The calculated DFs are represented by a 2D map against the center frequency and frequency resolution. The maps from different fault features are stacked together to form the diagnostic patterns. Thirdly, a pretrained convolutional neural network (CNN) is applied to learn the feature pattern and diagnose the bearing faults. The CNN is trained using fixed-speed data and then it is applied to diagnose faults in the test data recorded at the same speed. Then, it is also tested using variable-speed data and data of another ball bearing type in order to show the independency on the rotational speed and ball bearing type in practice. The results show a 100% success rate for the constant-speed tests and 98.16% accuracy for the variable-speed testing dataset. The accuracy of diagnosing the faults of the second type of ball bearing is 98.56%. The diagnosis accuracy of the proposed method is still high even when a white noise is artificially added to the signals in the noise insusceptibility test. Comparison with other approaches that use different input features to the CNN shows that the proposed is superior in terms of diagnosis accuracy.
Long-time behaviour for a nonlocal model from directed polymers
Authors: Gu Yu , Henderson Christopher
Published: December 2022

We consider the long time behaviour of solutions to a nonlocal reaction diffusion equation that arises in the study of directed polymers in a random environment. The model is characterized by convolution with a kernel R and an L
2 inner product. In one spatial dimension, we extend a previous result of the authors (arXiv:2002.02799), where only the case

R
=
δ

was considered; in particular, we show that solutions spread according to a

2

/

3

power law consistent with the KPZ scaling conjectured for directed polymers. In the special case when

R
=
δ

, we find the exact profile of the solution in the rescaled coordinates. We also consider the behaviour in higher dimensions. When the dimension is three or larger, we show that the long-time behaviour is the same as the heat equation in the sense that the solution converges to a standard Gaussian. In contrast, when the dimension is two, we construct a non-Gaussian self-similar solution.
Characteristic analysis of magnetorheological fluid porous fabric composite with a novel constitute model
Authors: Li Pingyang , Dong Xiaomin , Wang Kaixiang , Ran Jinchao , Yang Baolin
Published: December 2022

As a novel material, magnetorheological fluid porous fabric composite (MRF-PF) has not been further analyzed and modeled. In this paper, mechanical properties of MRF-PF are analyzed quantitatively and qualitatively with a novel constitute model. Considering the wall slip, viscoelasticity and internal porous network of MRF-PF, a constitute model of MRF-PF is derived firstly which can describe the performance precisely. According to experimental results, mechanical properties of MRF-PF are different from conventional MRF. Shear stress τ decreases first, then increases slowly at off-state. Under low magnetic field, shear stress τ presents the opposite variation. It increases at first, and then decreases rapidly. With the further increase of magnetic field, Shear stress τ increases dramatically at high shear rate. This effect is determined by the internal porous network and absorption degree of MRF-PF. A possible flow mechanism of MRF-PF has been proposed. Comparing with different types of MRF-PFs, pre-immersed MRF-PF without relative rotation has a better performance. The maximum shear stress can reach as high as 62.35 kPa with an increase of 22.37% under the magnetic field of 0.7 T. The corresponding dynamic yield stress τ
y
increases to 55.18 kPa with an increase of 26.6%. What is more, internal porous network can support the particle chains to reinforce the shear-resistance property. The shear thinning effect of MRF-PF can be improved significantly. However, MR effect of MRF-PF decreases largely. These attractive mechanical properties make MRF-PF a potential choice for critical engineering applications.
Study of contact conditions at conductor/insulator interfaces used in space charge distribution measurements
Authors: Zheng Lin , Holé Stéphane
Published: December 2022

Interfaces play a major role on charge injection in dielectrics under high voltage. As a consequence, space charge distribution measurements under high voltage may depend on the chosen interface conditions during the tests. In this paper, it is shown that various mountings of an insulating polymer (polyethylene) in a space charge distribution measurement setup develop very different intrinsic dipoles at the interfaces generating in turn an interface voltage that may interact with energy levels between the electrode and the insulator and thus with injection laws. These dipoles are minimal when the insulating polymer has hot-pressed carbon-loaded polymer electrodes or is coupled with silicone oil to carbon-loaded EVA electrodes. On the contrary aluminum coating or direct contact with aluminum in presence of silicone oil for the coupling generates large dipoles compared to gel coupling or with gold coating. The measurements were carried out with an ultra sensible pressure-wave-propagation measurement setup under very low electric field (±30 V/mm at most) for calibration purpose. Aluminum and stainless steel was used for the setup wave-guide in order to check its influence. Interface voltage up to 5 V could be estimated with an uncoated sample in contact with aluminum through silicone oil.
Generalization of the Guendelman nonlinear electrodynamics model
Authors: Mazharimousavi S Habib
Published: December 2022

In this study, we present a generalized version of the specific nonlinear electrodynamic model introduced by Guendelman [PLB640(2006)201] as a result of spontaneously breaking the scale invariance of Maxwell’s linear theory. The generalized model involves a new integer parameter n so that n = 2 reproduces Guendelman’s model. Although with each n in principle there exist a new model but technically only n = 2 and n = 3 yield a closed analytical expression.
Local delivery of tacrolimus using electrospun poly-ϵ-caprolactone nanofibres suppresses the T-cell response to peripheral nerve allografts
Authors: Roberton V H , Gregory H N , Angkawinitwong U , Mokrane O , Boyd A S , Shipley R J , Williams G R , Phillips J B
Published: December 2022

Objective. Repair of nerve gap injuries can be achieved through nerve autografting, but this approach is restricted by limited tissue supply and donor site morbidity. The use of living nerve allografts would provide an abundant tissue source, improving outcomes following peripheral nerve injury. Currently this approach is not used due to the requirement for systemic immunosuppression, to prevent donor-derived cells within the transplanted nerve causing an immune response, which is associated with severe adverse effects. The aim of this study was to develop a method for delivering immunosuppression locally, then to test its effectiveness in reducing the immune response to transplanted tissue in a rat model of nerve allograft repair. Approach. A coaxial electrospinning approach was used to produce poly-ϵ-caprolactone fibre sheets loaded with the immunosuppressant tacrolimus. The material was characterised in terms of structure and tacrolimus release, then tested in vivo through implantation in a rat sciatic nerve allograft model with immunologically mismatched host and donor tissue. Main results. Following successful drug encapsulation, the fibre sheets showed nanofibrous structure and controlled release of tacrolimus over several weeks. Materials containing tacrolimus (and blank material controls) were implanted around the nerve graft at the time of allograft or autograft repair. The fibre sheets were well tolerated by the animals and tacrolimus release resulted in a significant reduction in lymphocyte infiltration at 3 weeks post-transplantation. Significance. These findings demonstrate proof of concept for a novel nanofibrous biomaterial-based targeted drug delivery strategy for immunosuppression in peripheral nerve allografting.
Study on Mixed Match Method of Factory-incoming Coal in Coal-fired Power Plants from the Perspective of Carbon Emission
Authors: Li Hongji , Wang Li
Published: December 2022

In order to better guide the mixed match of furnace-incoming coal in coal-fired power plants from the perspective of carbon emission, according to national carbon emission accounting guidelines for power generation facilities, regardless of the impact of coal storage on coal quality, we have built a coal quality information database for carbon emissions of factory-incoming coal through analyzing the factory-incoming coal source and industrial analysis data on coal quality in a coal-fired power plant as well as using the element carbon content information estimated by soft measurement of element carbon content verified through the test. Based on this, we have constructed the theoretical method to guide the mixed match of furnace-incoming coal, and obtain the optimized mixed match results through the mixed match analysis.
Research on an SAE-based Substation Noise Monitoring Method
Authors: Ma Yuchao , Wang Xin , Jizhong Fang , Qingming Xiao
Published: December 2022

In the area of transformer noise monitoring research, condition monitoring technology based on the combination of AI technology and modern signal processing methods gradually becomes a hot research topic. General pattern recognition methods often have higher requirements for signal acquisition and processing and are often restricted by the limited generalization ability of the models. In order to solve this problem, a sparse autoencoder-based transformer state recognition method is proposed. The sparse autoencoder (SAE) is trained by FFT spectral signals, and the intrinsic features of big data are adaptively refined into simple feature functions. Intelligent diagnosis of transformer conditions is realized by the expression of feature functions. The experimental results show that, compared with BP (backpropagation) neural network and SVM (support vector machine) classification algorithms, this method can quickly and effectively improve the accuracy of transformer state recognition, which is of great significance for industrial development.
Seismic performance analysis of a UHV converter transformer bushing system
Authors: Liu Zhenlin , Xue Zhihang , Lu Zhicheng , Meng Xianzheng
Published: December 2022

A finite element model of a UHV converter transformer was established to study how the seismic response of bushings and the amplification effect of the transformer tank on its bushing, one AC bushing, and two DC bushings. The frequency of DC bushings was smaller than that of the AC bushing, with the first four frequencies being all the modes of DC bushings. The results of stress and displacement response showed that the AC bushing was more affected by horizontal seismic action, while the two DC bushings were more sensitive to Z-direction seismic excitation. Besides, the stress amplification factor was used to evaluate the seismic amplification effect of the transformer tank on bushings.
An Approach of Malware Detection in Power System
Authors: Han Wei , Cai Deyu , Du Xingwei , Ma Weidong , Guo Pei , Wang Feng , Wang Shuzhou , Zhao Zhibo
Published: December 2022

In recent years, cyber attacks against the power industry have occurred frequently, causing huge losses to national infrastructure construction. As an important carrier of network attacks, malware has a great threat to the power system. This paper proposes an E-Gemini model based on the analysis of binary executable files and traditional malware detection techniques. This model was developed by Gemini [1] and has a stronger analysis ability for malware in power systems. This paper also alleviates the problem of the small size of the current power system malware dataset by pretraining and retraining. Experiments have verified the effectiveness of the E-Gemini model. The results show that the proposed model can achieve a maximum accuracy of 89%, which is significantly improved compared to the baseline method.
Pressure changes of nitrogen blanket transformers under internal short circuit faults
Authors: Li Jiansheng , Yang Xiaoping , Wu Yiming , Wang Shengquan
Published: December 2022

The root cause of the transformer fire is an oil tank crack caused by an internal short circuit fault. The gas layer of the nitrogen blanket transformer helps buffer the pressure change caused by the internal short-circuit fault. Moreover, the pressure change simulation is the basis for the configuration of non-electrical protection. This paper analyzes the relationship between the energy and pressure source of the internal short-circuit fault. Based on finite element simulation, the internal pressure transfer model of the transformer is built, and the pressure of the oil tank is obtained. By comparing with the pressure of conventional transformer, the excellent explosion-proof performance of nitrogen blanket transformer is verified.
Study on Vibration Isolation Design Analysis of 500 kV Indoor Substation
Authors: Meng Xianzheng , Gao Po , Liu Zhenlin , Lin Sen , Sun Yuhan
Published: December 2022

In order to study the applicability of isolation technology for indoor substations, this paper establishes a numerical prototype and isolation structure simulation model of a 500 kV indoor substation building structure by using finite element software. Modal analysis and seismic response analysis are carried out to study the dynamic characteristics and seismic response rules of the building for the prototype and isolation structure. The numerical simulation results show that the higher the floor, the more significant the amplification of the acceleration response, and the acceleration response amplification coefficients of the second and third floors are greater than the 2.0 required by the code. The transverse shear force of the first column is reduced by 78%, the acceleration response of the second and above floors is reduced by 80%, and the seismic fortification intensity of the second and above electrical equipment can be reduced by one degree. The maximum displacement of the isolation bearing is 310.32 mm, which is smaller than the limiting displacement of the minimum type of isolation bearing, which is 330 mm. The performance of the isolation bearing is in the safe and stable region, and the isolation design scheme is more reasonable. Compared with the prototype structure, the isolation design scheme significantly reduces the inter-story displacement of each floor, and the concrete frame of the isolation structure is in the elastic region under the earthquake action, which improves the seismic performance of the building and electrical equipment.
Hardware Platform Construction of Hybrid Modular Multilevel Converter Purely Based on FPGA Controller
Authors: Zhang Jianbin , Hao Quanrui , Li Dong
Published: December 2022

The modular multilevel converter (MMC) hardware platform is of great significance to the research of control and protection before engineering operation. In practical engineering, each bridge arm is composed of many submodules (SMs) cascaded, which brings significant challenges to the research. In this paper, a controller based on a field programmable gate array (FPGA) is designed for hybrid MMC, and a hardware platform is built on this basis. The platform fully uses the parallel characteristics of FPGA to improve the calculation speed of the controller. It optimizes the SM capacitor voltage sorting method to shorten the sorting time significantly. The stability experiment verifies that the hardware platform can be applied to the research of hybrid MMC.
SOC Estimation of Lithium-ion Batteries at Different Temperatures
Authors: Chen Yuhang , Xiong Hongjun , Guo Yi
Published: December 2022

With the development of new energy vehicles, an accurate estimation of SOC was crucial for the battery pack’s safe and dependable functioning. Experiments with the NCR18650B lithium-ion battery were made at different temperatures: low temperature (0°C), room temperature (25°C), and high temperature (45°C). A fractional order model and BP neural network algorithm were adopted to estimate the battery charge state of the lithium-ion battery. The experimental findings indicated that the error could be limited to 10% or below, which essentially satisfied the power battery charge status estimate accuracy criterion.
Double-layer Optimization Study of Virtual Power Plants with Source-load-storage
Authors: Yu Changle , Li Wenwen , Liu Nian , Yang Lin , Zhang Su , Wan Jia
Published: December 2022

In order to effectively solve the supply-demand imbalance of the grid caused by intermittent new energy penetration and improve the scheduling flexibility of virtual power plants, a two-layer optimization model of virtual power plants with source-load-storage is proposed. The upper layer of the model is designed to reduce the forecast error of wind power output and improve the revenue of the virtual power plant. On the basis of the maximum wind power consumption, distributed energy storage and fuel cells are used to coordinate and compensate for the deviation between the planned and actual output of renewable energy. The active output of the upper layer is transferred to the lower layer. The lower layer of the model is solved by using the improved linear decreasing inertia weight particle swarm algorithm for the output of the gas turbine unit. The analysis results show that the model can absorb the excess new energy generation in the grid, achieve the balance of supply and demand regulation in the grid, and effectively reduce the economic operation cost of the system.
Reactive Power Compensation Configuration of Offshore Wind Power Based on Economic Differential Pressure Theory
Authors: Chen Meng , Tang Xiaojun , Chen Dezhi , Chao Wujie , Gao Wenman , Yang Daye , Luo Hongmei , Zou Yucheng , Pei Lijie
Published: December 2022

The conventional reactive power balance analysis method for offshore wind power transmission projects can be used to obtain many feasible solutions for reactive power compensation configuration, which requires a large number of simulation calculations to eliminate unreasonable schemes. The work is tedious and lacks theoretical guidance. In this paper, the main influencing factors, such as the current carrying capacity of offshore wind power and submarine cable, the mode of real-time power generation, and the reactive power output regulation of the wind turbine itself, are considered. The reactive power balance of offshore wind power transmission projects is derived. Combined with the economic differential pressure theory, the sea-side and land-side configuration methods of high reactance and dynamic reactive power compensation are put forward. On the basis of realizing real-time reactive power balance, the recommended reactive power compensation configuration scheme effectively reduces the active power loss of the transmission project, and at the same time, lowers the bus voltage of each node at sea, thus reducing the high risk of the excessive voltage of offshore wind farm. This project is supported by the Science and Technology Project of State Grid Corporation of China under “Research on multiple temporal and spatial coordinated optimal control theory for medium and long-distance large-scale offshore wind power transmission system” (No. 5100-202155305A-0-0-00).
Development of Horizontal Vibration-type Synthetic Electric Field Measurement Prototype
Authors: Zhang Zhenyu , Chen Xiufang , Han Haian , Fang Shubo
Published: December 2022

At present, field grinding measurement devices are mainly adopted for DC synthetic electric field measurement. The sensor unit of the device is of a rotating blade structure, and the surface wind generated by rotation causes ion flow distortion, making it difficult to ensure the accuracy of measurement data. In order to optimize the sensing structure of measuring equipment, the vibration-type synthetic field sensing mode was obtained through selection analysis, the horizontal vibration sensor structure and data acquisition hardware circuit structure were proposed, and a vibration-type synthetic field measuring prototype was developed. Through the simulation comparison of the influence of vibration type and field grinding type on the electric field, it can be known that the internal field intensity of the upper and lower 1 mm planes of the equipment shell is basically uniform, and the field intensity of the square and the corner position of the equipment shell are distorted. The electric field distortion of the upper surface of the field grinding device and vibration device is 2.36-8.55 and 1.9-6.84, respectively. The higher the device is, the greater the distortion of the field intensity near the shell, and the distortion of the field grinding type is larger than that of the vibration type. Vibration equipment has less influence on the background field intensity when measuring the ground composite field intensity.
Bi-level Optimization Model of PMU Fault Recovery Based on Observability
Authors: Xue Fei , Wang Xiaoli , Ma Xin , Li Hongqiang
Published: December 2022

Aiming at the failure of PMU caused by cyber-attacks and extreme natural disasters, a bi-level optimization model of PMU fault recovery based on observability is proposed in this paper. By optimizing the sequential restoration of PMU, the control center can maximize the state observability of the system under the condition of limited recovery resources and adjust the power in real time according to the recovered observable nodes, so as to alleviate the power imbalance caused by a disturbance in the recovery process. The upper optimization model takes the maximum observable branch power flow as the optimization objective, and the lower optimization model is constructed as the DC optimal power flow model with the lowest power generation cost. The upper and lower models are coupled by the branch power flow and the node observation state. Then, the lower model is transformed into KKT conditions through Lagrange multiplication, and the nonlinear objectives and constraints are linearized so that the bi-level model can be transformed into a single-level mixed integer linear programming model for solving. Finally, the effectiveness of the proposed strategy is verified by simulation analysis of IEEE39 standard systems.
Dynamic Aggregation Method of Wind Farms with Virtual Synchronous Generator-Controlled Wind Turbines
Authors: Xie Wanying , Qi Xiaoguang , Chen Changsheng , Zhang Qianmao , Tian Jiahui , Zheng Liwen
Published: December 2022

The frequency and voltage dynamic processes of each wind turbine in the existing wind farm are different, and the available aggregation model of wind farms mainly focuses on the steady-state output power, lacking an effective dynamic aggregation mechanism. Wind turbines usually adopt the virtual synchronous generator method (VSG) to simulate the external characteristics of the traditional synchronous generator. Its frequency dynamic response is mainly affected by the virtual inertia and damping parameters, and the excitation regulator parameters determine the voltage dynamic response. Therefore, the aggregation method of the traditional synchronous generator is also applicable to such wind turbines. Firstly, the dynamic characteristics of the points of wind farms’ point of common coupling (PCC) are discussed. Then, the dynamic aggregation method of the VSG-wind farms is proposed based on the Kuramoto (KM) model and the small signal analysis of the wind turbines. Finally, a wind farm consisting of multiple VSG-wind turbines under disturbances is simulated in PSCAD/EMTDC to verify the effectiveness of the proposed dynamic aggregation method.
Research on DC Line Protection Method of Large PV Plant Based on Transient Direction
Authors: Zhang Yan , Zhu Yongqing , Zhang Zhaofeng , Zhang Pengcheng , Huang Yuhui
Published: December 2022

Due to the complex fault transients associated with DC convergence in photovoltaic (PV) plants and the large number of power electronics used in systems, the protection device is unable to determine the location of faults, and thus the protection is inadequate. This paper proposes a protection scheme for the DC system of a large PV plant. The accurate model of the PV plant is built in consideration of the DC system, including the current limiter. The differential voltage and current are utilized to realize the location of the fault section. The voltage transients are used to locate the fault within the section accurately. Study cases in PSCAD/EMTDC show the proposed protection scheme is effective and practically useful for PV plants.
Research on ultra-reliable and low-latency secure transmission of distribution monitoring communication system
Authors: Li Ruide , Dai Wenxia , Zhang Haomin
Published: December 2022

In the smart distribution network scenario, we investigate the physical layer security performance of power line communication in FBL. The results show that the system secure transmission rate increases with increasing channel block length and eventually converges to a constant value. Compared with the traditional SE maximization algorithm based on FBL, the total secrecy rate is improved by about 13%. Compared with the traditional linear precoder (ZF), the secrecy rate is improved by about 30%. Therefore, the proposed scheme is superior in supporting the power line communication system based on FBL.