bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of Three-Dimensional Placement of Built-in Catalytic Partial Oxidation Catalyst in an Anode-Supported Honeycomb SOFC
Authors: Higa Tasuku , Nakajima Hironori
Published: July 2021

Honeycomb solid oxide fuel cells (SOFCs) can achieve high power density with improved thermo-mechanical durability at high temperatures [1]. In this study, a compact SOFC with catalytic partial oxidation reforming catalyst embedded in the flow channels of a porous honeycomb anode support has been fabricated and evaluated. I-V measurements and gas chromatography for the outlet gas were carried out while methane/air mixture gas was fed as fuel. I-V measurements were performed to compare the performance of the two configurations: one with fuel supplied from the central channel and discharged from the surrounding four channels, and the other with fuel supplied from the four channels and discharged from the central channel. As a result, the effect of concentration overpotential was smaller in the latter case. The gas chromatograph detected hydrogen in the reformed gas for both cases.

Acknowledgments

Thanks are offered to Professor Kohei Ito of Kyushu University for valuable discussions.

References

H. Nakajima, S. Murakami, S. Ikeda, and T. Kitahara, Heat Mass Transfer, 54, 2545 (2018).
Electrical Conductivity of La0.9Sr0.1Ga0.8Mg0.2O3-D/La1.55Sr0.45Ga3O7+D Composite Electrolyte
Authors: Fujimoto Talita Gishitomi , Steil Marlu Cesar , Muccillo Eliana Navarro dos Santos
Published: July 2021

Doped lanthanum gallate constitutes a family of solid electrolytes with high ionic conductivity, wide electrolytic domain and good chemical stability. The combination of their properties turns some compounds of this family, promising candidates for application in solid oxide fuel cells operating at intermediate temperatures. In this work, La0.9Sr0.1Ga0.8Mg0.2O3-δ - x La1.55Sr0.45Ga3O7+δ, with x = 0, 1 and 5 wt.% were investigated aiming to obtain a composite solid electrolyte with optimized properties compared to the parent material. Composite electrolytes were prepared by solid state reaction method and evaluated for densification, phase content and microstructure. Electrical conductivity measurements were carried out as a function of temperature and oxygen partial pressure.

Increase on densification and microstructural homogeneity were obtained with increasing fraction of the melillite phase. The electrical conductivity determined by impedance spectroscopy revealed a decrease of the grain resistivity for increasing amounts of La1.55Sr0.45Ga3O7+δ.
Influence of Sr2+ Concentration and A-Site Deficiency on Surface Stability of (La1
-
ySry)xCr0.5Mn0.45 Ni0.05O3
-δ
Authors: Kivi Indrek , Korjus Ove , Moeller Prit , Aruväli Jaan , Nurk Gunnar
Published: July 2021

(La1–
xSrx)yCr0.5Mn0.45Ni0.05O3–

δ
(LSCMN) is a perovskite (ABO3) type mixed ionic-electronic conductive (MIEC) oxide and has been proposed as an electrode material for high temperature fuel cell [1]. The material is catalytically active for oxidation of hydrogen and hydrocarbons [2]. A significant amount of attention has been paid to clarify the dependence between crystallographic and electrical properties of LSCM-based materials [1, 3]. Some papers also deal with stability issues if the material is used as an anode in a solid oxide fuel cell [3, 4]. So far, there is a lack of information about the dependence between A-site stoichiometry and stability of chemical composition- and electrochemical performance of LSCMN surface.

In this work, La/Sr ratio and deficiency of A-site, i.e. A-site stoichiometry of (La1–
xSrx)yCr0.5Mn0.45 Ni0.05O3–δ
were varied and chemical composition of LSCMN surface and electrochemical performance was monitored. The electrochemical measurements of symmetric cells (100 h tests) show that small stochiometric changes in A-site significantly influence the activity and initial degradation rate of the electrode. The chemical and structural changes of the material surface (segregation of some LSCMN components onto the surface and decomposition of perovskite phase) have a key role in the electrochemical performance of the electrode [3].

The electrode materials were analysed using XRD, TOF SIMS and electrochemical methods. XRD results for studied electrode powders showed significant dependence on the lattice parameters on the A-site composition. Materials were treated in two different gas environments – in synthetic air and in H2 environment, both at 1123 K for one hundred hours. TOF SIMS analysis demonstrated the dependence of the surface stoichiometry on the A-site stoichiometry of bulk electrode as well as on gas environment during heat treatment. The results from impedance spectroscopy (measured at temperatures from 973 to 1123 K in H2 environment, at OCV) demonstrate a significant influence of the A-site deficiency and La/Sr ratio on the series- and polarization resistance of the electrode. The electrochemical activity and surface compositions were correlated and reasons of relative stoichiometric changes of the surface compared with bulk were discussed.

Yue and J.T.S. Irvine, Solid State Ionics, 225, 131 (2012).

Bidrawn, G. Kim, G. Corre, J.T.S. Irvine, J.M. Vohs, R.J. Gorte, Electrochem. Solid-State Lett. 11, B167 (2008).

Korjus, J. Aruväli, P. Paiste, K.Kooser, S. Granroth, H. Mändar, M. Kodu, R. Härmas, M. Maide, M. Ainsar, E. Lust, G. Nurk, Fuel Cell, 20, 6, 741 (2020).

C. Lu, J. H. Zhu, Solid State Ionics, 178, 1467 (2007).
Microstructure and Performance Analysis of Low-Temperature Solid Oxide Fuel Cells Synthesized on Inert Al2O3 Substrates
Authors: Solovyev Andrey , Shipilova Anna , Smolyanskiy Egor , Rabotkin Sergey , Semenov Vyacheslav , Matveev Danila
Published: July 2021

In order to lower the SOFCs operating temperatures new electrolyte materials should be used instead of yttria-stabilized zirconia (YSZ) and the thickness of electrolyte should be decreased to the low micrometer range. To prepare the thin electrolyte, physical vapour deposition methods, such as magnetron sputtering, leading to dense, pinhole-free thin films, are ideal. If, additionally, also the anode and cathode materials are kept thin, low-temperature cells are obtained, also called micro-SOFCs.

To demonstrate the possibility of creating such thin-film layers, model anodes and anode/electrolyte systems were prepared on porous anodic aluminum oxide (AAO) substrates. As electrolyte material, Ce0.8Gd0.2O1.9-x (GDC) was used. The composite consisted of NiO and GDC was used as anode. The main advantage of GDC electrolyte for solid oxide fuel cells is four to five times higher ionic conductivity compared to YSZ in the temperature range 500-800°C.

The microstructure of NiO-GDC thin-film anode after reduction in hydrogen at temperatures of 450 and 600°С was studied. It was found that at these temperatures there is also agglomeration of Ni particles and segregation on the film surface in the form of small particles as in [1] at 850°C. It is also shown that annealing of the deposited NiO-GDC anode layer at 1000°С allows stabilizing its structure and excluding subsequent agglomeration of Ni particles during operation in a hydrogen atmosphere. Figure 1 shows the microstructure of NiO anode/GDC electrolyte system deposited on AAO substrate.

Button cells with a diameter of 13 mm and with different thicknesses of the anode and electrolyte were fabricated. A La0.6Sr0.4CoO3 cathode (Kceracell Co., Korea) was screen printed on the electrolyte surface and sintered in situ during cell testing in temperature range of 500–600°C. First investigations showed promising results, namely high open-circuit voltage values (0.8 V) and a power density up to 100 mW/cm² at 550°C in pure hydrogen. However, the impedance analysis of the cells points out that further anode and cathode optimization would be beneficial for the overall cell performance.

[1] F.J. Garcia-Garcia et al., Int. J. Hydrog. Energy, 40(23), 7382 (2015)

Figure 1: The microstructure of anode/electrolyte system deposited on AAO substrate (scanning electron microscopy)

Figure 1
Optimization of a Natural Gas Fuel Cell Power Plant without Carbon Capture
Authors: Noring Alexander , Zamarripa-Perez Miguel , Iyengar Arun , Burgard Anthony , Bao Jie , Wang Dewei , Xu Zhijie , Koeppel Brian , Miller David
Published: July 2021

This work aims to optimize a solid oxide fuel cell (SOFC)-based natural gas fuel cell (NGFC) system with the potential for higher heating value (HHV) efficiencies as high as 70 percent. This work leverages the IDAES Integrated Platform (IDAES), an equation-oriented tool for the nonlinear optimization of advanced energy systems, which enables a broader exploration of the potential design space than convention case-based analyses. The NGFC system model without carbon capture consists of a natural gas reformer, SOFC power island, and steam turbine bottoming cycle. The mass and energy balances are modeled with first principles models, while the SOFC behavior is captured utilizing a machine learning-based reduced order model (ROM) developed from a validated, high fidelity CFD stack model. The objective of the study is to find the optimal NGFC configuration and operating conditions that maximize the system efficiency and reduce carbon dioxide emissions. The results of the optimization to date have led to improved system performance (higher efficiency). Further work will focus on analyzing different potential configurations to increase efficiency and reduce CO2 emissions.
Gas Containment Systems for Stationary and Mobile Applications
Authors: Nunic Radisa
Published: July 2021

While green hydrogen production should remain the main target toward Zero Emissions Society, it would be prudent to maximize the utilization of easily accessible energy carries available already today in abundance.

Compressed Natural Gas (CNG) represents a widely available energy carrier. Approximately 4.000 CNG/LNG car filling stations are available, thus enabling CNG to be used as fuel for
commercial and personal vehicles based on the SOFC technology. Employing SOFC up to 30% higher efficiency can be achieved in comparison with conventional combustion engines. The
SOFC based vehicles fueled by CNG can thus represent a perfect intermediate solution toward CO2 reduction and elimination of NOx emissions.

Decentral power and heat generation via SOFC in combination with CNG offers yet another pathway to reach CO2 targets set by the European Union. Conditions for continued, more rapid growth of SOFC technology are favorable as global demand seeks different clean emissions heat and power generation solutions.

Worthington as a center of excellence is focused on the design and production of high-pressure cylinders and onboard fueling systems for mobile applications, like vehicle integration, gas transport containers and stationary storage solutions. Ensuring easier fuel storage and transport, application and commercialization of SOFC based systems for mobile application can be accelerated.

Worthington Industries is a global value-added steel processing company with headquarters in Columbus, Ohio, USA and production sites in Austria, Poland, and Portugal dedicated to pressure cylinder solutions for sustainable mobility. In addition to an overview of our approach to advancement of SOFC utilization, we intend to cover, as well, the availability of gas street components, system integration, safety, maintenance and product lifetime of proposed onboard fueling systems.
(Plenary) The Status of SOFC and SOEC R&D in the European Fuel Cell and Hydrogen Joint Undertaking Programme
Authors: Atanasiu Mirela , Tsimis Dionisis , Aguilo-Rullan Antonio , Lymperopoulos Nikolaos , Dirmiki Dimitra
Published: July 2021

The Fuel Cells and Hydrogen Joint Undertaking (FCH JU) was set up in 2008 to accelerate the development of fuel cells and hydrogen technologies in Europe towards commercialization from 2020 onwards. To reach this target the FCH JU brings together resources under a cohesive public-private partnership to ensure commercial focus, to match RTD activities to industry's needs and expectations and to scale-up and intensify links between the Industry Community and the Research Community. Supported topics cover all fuel cell technologies, SOFC being mostly developed for the stationary heat and power applications, while SOEC technologies are considered for the hydrogen production applications.

There are different groups working in Europe on the SOFC/SOEC technologies and supported partially by the FCH JU. So far, around €218 million have been allocated to support 58 projects, which address specifically SOFC or SOEC technologies. Support to Solid Oxide technologies represents 40-50% of the support provided to energy-related projects. Largely thanks to this support, the EU is now a world leader on SOFC and SOEC technology with a well-established supply and value chain. In addition, a number of EU companies have commenced their efforts to increase their manufacturing capabilities with views to introduce their products beyond Europe. The FCH JU presentation will cover the status of R&D in Solid Oxide technologies in Europe including an overview of the European competiveness in this sector.

Occurences of publications, conferences, patents for the period 2010-2021 for SOFCs (right) and SOECs (left) – source: Tools for Innovation Monitoring (TIM) Too, Joint Research Centre

Figure 1
An Optimized Strategy for Fuel Cell Degradation Control in SOFC Power Systems
Authors: Zhu Jianzhong , Wu Xintao , Sun Kaihua , Han Minfang
Published: July 2021

Solid Oxide Fuel Cell (SOFC) is an attractive energy conversion device due to its high efficiency and fuel flexibility. Key operation parameters such as current, temperature and fuel utilization are critical variables in SOFC systems that directly impact efficiency and longevity. The degradation of the SOFC performance not only limits the operating temperature range of the SOFC stack in the system, but also simultaneously generates Joule heat, which further causes the stack to deviate from its initial thermal balance.

In this paper, a semi-empirical SOFC dynamic model with degradation is proposed and validated by experiment data. The degradation in the above model is developed based on current density, temperature and fuel utilization to simulate cell performance decay over time due to ohmic loss growth and the heat generation by cell resistance. The coupling between key parameters, stack performance and degradation during long-term load following and the impact of stack degradation on the entire system long-term performance is discussed and investigated. An optimized strategy uses both feedback and feed-forward control law is designed to track the desired power demand with the aim of mitigating the degradation and compensating the time differences between dynamics at different time-scale.

References

1. Shi W, Zhu J, Han M, et al. Operating limitation and degradation modeling of micro solid oxide fuel cell-combined heat and power system[J]. Applied Energy, 2019, 252: 113444.

2. Zaccaria V, Tucker D, Traverso A, et al. Active Control of Fuel Cell Degradation in an SOFC/GT Hybrid System[C], Turbo Expo: Power for Land, Sea, and Air. American Society of Mechanical Engineers, 2017, 50831: V003T06A035.

3. Murshed A K M M, Huang B, Nandakumar K. Control relevant modeling of planer solid oxide fuel cell system[J]. Journal of Power Sources, 2007, 163(2): 830-845.

4. Das T, Weisman R. A feedback based load shaping strategy for fuel utilization control in sofc systems[C], 2009 American Control Conference. IEEE, 2009: 2767-2772.

5. Spivey B J, Hedengren J D, Edgar T F. Constrained control and optimization of tubular solid oxide fuel cells for extending cell lifetime[C], 2012 American Control Conference (ACC). IEEE, 2012: 1356-1361.

6. Sreedhar I, Agarwal B, Goyal P, et al. An overview of degradation in solid oxide fuel cells-potential clean power sources[J]. Journal of Solid State Electrochemistry, 2020, 24: 1239-1270.

Figure 1
LSCo/LSCF Composite Material As Cr-Gettering Materials for Solid Oxide Fuel Cells
Authors: Chou Yeong-Shyung , Canfield Nathan L , Jin Tongan , Bonnett Jeff , Choi Jung Pyung , Hardy John S
Published: July 2021

Chromium poisoning has been identified as the main cause for degradation when metallic parts are used in SOFC. Early mitigation was focused on protective coatings. Recently, Cr-gettering materials have been explored either in upstream or on-cell applications. In previous work, we have shown LSCF can readily trap Cr volatile species at elevated temperatures. In this work we propose LSCo/LSCF composite as a candidate for on-cell Cr-gettering materials. LSCo will be mixed with base material of LSCF4628 at 10, 20, and 30 v%, because of its high electrical conductivity. Mixed powders will be pressed and sintered as pellets and rods. Sintered rods will be tested for CTE. Measured CTE will be compared with predictions from rule of mixtures. XRD will be used to characterize crystalline phases to assess chemical compatibility. The sintered pellets will also be measured electrical conductivity at 650-900oC in the as-sintered and 1000h aged state. Selected sample microstructures will be characterized by SEM/EDS and EPMA. Bulk strength will also be determined by diametral compression. Finally, candidate LSCo/LSCF4628 will be tested as on-cell in a generic stack test fixture at 800oC for 1000h with Cr volatile species, along with baseline cell. Post-mortem microstructure analysis will be conducted to assess the validity of on-cell gettering.
Structural Stability of Nickel Electrodes in Solid Oxide Cells
Authors: Yashiro Keiji , Furuhashi Ron , Kawada Tatsuya
Published: July 2021

1. Introduction

Long-term durability is an issue of solid oxide cells (SOCs). Degradation of SOCs is most pronounced in a fuel electrode, where length of three-phase boundary, that is active reaction site, decreases. The major cause of the decrease in the three-phase boundary is nickel aggregation. The mechanism of Ni aggregation has been proposed to be Ni transport through the gas phase by nickel hydroxide. However, experimental facts did not support the hypothesis, suggesting that Ni transport through the gas phase should not be major factor [2].

Because Ni-YSZ fuel electrode has a complex three-dimensional structure, it has been difficult to elucidate the mechanism of Ni transport. Therefore, it is natural to use nickel model electrode to simplify the evaluation of microstructure change of nickel, which will lead to the elucidation of the degradation behavior. Jiao et al. observed the microstructure change of Ni using Ni grid electrodes [3]. The structural change of Ni was attributed to change in wettability of Ni by applied voltage, where the wettability increased under anodic polarization and decreased under cathodic polarization.

In this study, we aim to establish a method to observe the structure change of Ni inside the electrodes by modeling the complex structure of Ni-YSZ porous electrodes using patterned electrodes.

2. Experimental

Fig. 1 (a) shows the simulated cross section of a symmetrical Ni-YSZ porous electrode cell. To model the cross section of porous Ni-YSZ fuel electrode, dense nickel-film patterned electrodes were fabricated on the YSZ substrate as shown in Fig. 1 (b) and (c). In this model cell, YSZ locating between two opposed nickel electrodes simulates the electrolyte, while the comb-shaped Ni pattern electrode simulates the porous Ni; YSZ surface between Ni fingers represents porous YSZ. Using this cell, transport of Ni in the direction of the electrode cross-section can be observed from top. After certain period of polarization to the cell, microstructure change of nickel was observed by microscope.

3. Results and discussion

After SOFC operation, the cross-sectional area of nickel electrode was the largest at the tip of the model electrode, suggesting that Ni migrated toward the tip. On the other hand, after SOEC operation, the cross-sectional area was larger toward the root, suggesting that Ni migrated toward the root. These migration directions were consistent with those assumed by wettability. The results confirmed that wettability contributed to Ni migration in the model electrode and that wettability-induced Ni migration also occurred in the porous electrode.

References

[1] M. Trini et al., J. Power Sources, 450, 227599 (2020).

[2] Z. Jiao et al., J. Electrochem. Soc, 167, 024516 (2020).

Figure 1
Student perceptions on synchronous virtual versus face-to-face teaching for leader-centered and participant-centered postgraduate activities during COVID-19
Authors: Chandran Dinu S. , Kaur Simran , Deepak Kishore Kumar
Published: July 2021

Consequent to the unprecedented COVID-19 pandemic, pedagogic changes were introduced in postgraduate courses in Physiology, where face-to-face teaching was replaced with synchronous virtual mode for leader-centered (seminar, symposium) and participant-centered (journal club, group discussion) academic activities. We hypothesized that the effectiveness of virtual and face-to-face modes as perceived by postgraduate students in terms of facilitating their overall learning may differ across the spectrum of leader-centered and participant-centered activities. To assess the same, we designed and administered a comprehensive, structured, and validated feedback questionnaire. Postgraduate students ( n = 29) rated virtual sessions significantly more convenient, but less attentive and comprehensible, and reported better audiovisual experience during face-to-face sessions. Students rated flexibility to attend, self-paced learning, ability to revise, lookup for information in real time, and accessibility to distant expertise as important features of virtual sessions and instant feedback, eye-to-eye contact, and ability to interact in the group for face-to-face sessions. Virtual and face-to-face sessions were perceived as equally effective in facilitating their overall learning for the conduct of leader-centered seminars and symposia. However, face-to-face sessions were considered more effective for the conduct of participant-centered group discussions and journal clubs. During the pandemic, students perceive the synchronous virtual mode as an equally effective alternative for the conduct of leader-centered academic activities, but face-to-face teaching is still preferred for the conduct of participant-centered academic activities.
SPP1 Regulates Radiotherapy Sensitivity of Gastric Adenocarcinoma via the Wnt/Beta-Catenin Pathway
Authors: Sun Gangyi , Shang Ziyi , Liu Wenjia
Published: July 2021

Purpose. Radiotherapy has been widely applied for the treatment of locally advanced and metastatic gastric adenocarcinoma (GAC). The aberrant expression of secreted phosphoprotein 1 (SPP1) is involved in radiosensitivity in a variety of cancers. The present study aims to characterize the clinical significance of SPP1 expression in GAC and its role and underlying mechanism of radiosensitivity. Methods. The SPP1 expression in GAC tissues and pericarcinomatous tissues was determined by QRT-PCR and immunohistochemistry, and the SPP1 expression in GAC cell lines (BGC823, AGS, and SGC7901) and normal human gastric epithelial cell line (GES-1) was determined by western blot. T-test, one-way ANOVA, Cox regression model, and Kaplan–Meier plotter were applied to further assess the association between SPP1 expression and the prognosis of the patients with GAC. After irradiation and transfection with si-SPP1 combined with or without Wnt/β-catenin pathway inhibitor (XAV939), western blot, transwell, flow cytometry, and TOP-flash reporter assay were applied to detect DNA damage, invasion, apoptosis, cell cycle, and activation of Wnt/β-catenin pathway, respectively. Results. SPP1 mRNA and protein levels in GAC tissues were both dramatically higher than those in pericarcinomatous tissues. SPP1 overexpression was positively associated with tumor size, nodal status, and histological grade of GAC patients. SPP1 overexpression, depth of invasion, and nodal status were independent prognostic factors for the patients. High SPP1 expression was negatively related to the overall survival in patients with GAC. We found that SPP1 knockdown enhanced the radiosensitivity of GAC cell lines (AGS and SGC7901). Increasing H2AX phosphorylation, apoptosis and G2/M phase arrest, and decreasing invasion were observed after the administration of si-SPP1 and irradiation. Radiosensitivity of SPP1 was mainly dependent on the Wnt/β-catenin signal pathway. XAV939 could enhance these phenomena induced by irradiation combined with SPP1 knockdown. Conclusion. This study demonstrates that SPP1 suppresses Wnt/β-catenin signaling to enhance the radiosensitivity of GAC via inhibiting invasion and accelerating DNA damage, G2/M phase arrest, and apoptosis.
Numerical Investigation of Fractional-Order Differential Equations via
φ
-Haar-Wavelet Method
Authors: Alharbi F. M. , Zidan A. M. , Naeem Muhammad , Shah Rasool , Nonlaopon Kamsing
Published: July 2021

In this paper, we propose a novel and efficient numerical technique for solving linear and nonlinear fractional differential equations (FDEs) with the

φ

-Caputo fractional derivative. Our approach is based on a new operational matrix of integration, namely, the

φ

-Haar-wavelet operational matrix of fractional integration. In this paper, we derived an explicit formula for the

φ

-fractional integral of the Haar-wavelet by utilizing the

φ

-fractional integral operator. We also extended our method to nonlinear

φ

-FDEs. The nonlinear problems are first linearized by applying the technique of quasilinearization, and then, the proposed method is applied to get a numerical solution of the linearized problems. The current technique is an effective and simple mathematical tool for solving nonlinear

φ

-FDEs. In the context of error analysis, an exact upper bound of the error for the suggested technique is given, which shows convergence of the proposed method. Finally, some numerical examples that demonstrate the efficiency of our technique are discussed.
Prediction‐Based Maintenance of Existing Bridges Using Neural Network and Sensitivity Analysis
Authors: Miao Pengyong
Published: July 2021

Bridge deterioration is affected by various factors. However, neither the relationships between these factors and deterioration are explicitly determined, nor the relative effect of each factor on deterioration is well understood. This study proposed a methodology to resolve these issues by integrating an artificial neural network (ANN) and sensitivity analysis method. The ANN was used to predict deterioration, and the sensitivity analysis method was applied to evaluate the influence of each factor on deterioration. Testing the methodology with 3,368 bridge inspection data pieces indicates that (1) the developed ANN obtained an accuracy of about 65%; and (2) seven factors were identified affecting deterioration. The established ANN model has equivalent performance for three deterioration grades and four types of bridges. Two sensitivity analysis (the Shapley value and the Sobol indices) methods were compared, and they identified the same five most important factors. Consequently, the methodology can effectively avoid the uncertainty of factors on deterioration by providing a relative importance list of factors. The methodology’s predictive ability and factor importance identification ability make it suitable for decision‐makers to understand the deterioration situations and to schedule a further inspection and corresponding maintenance strategies.
Predicting Nanobinder-Improved Unsaturated Soil Consistency Limits Using Genetic Programming and Artificial Neural Networks
Authors: Ebid Ahmed M. , Nwobia Light I. , Onyelowe Kennedy C. , Aneke Frank I.
Published: July 2021

Unsaturated soils used as compacted subgrade, backfill, or foundation materials react unfavorably under hydraulically bound environments due to swell and shrink cycles in response to seasonal changes. To overcome these undesirable conditions, additive stabilization processes are used to improve the volume change phenomenon in soils. However, the use of supplementary binders made from solid waste base powder materials has become necessary to deal with the hazards of greenhouse due to ordinary cement use. Meanwhile, several studies are being carried out to design infrastructures even with the limitations of insufficient or lack of equipment needed for efficient design performance. Intelligent prediction techniques have been used to overcome this shortcoming as the primary purpose of this research work. Therefore, in this work, genetic programming (GP) and artificial neural network (ANN) have been used to predict the consistency limits, i.e., liquid limits, plastic limit, and plasticity index of unsaturated soil treated with a composite binder known as hybrid cement (HC) made from blending nanostructured quarry fines (NQF) and hydrated-lime-activated nanostructured rice husk ash (HANRHA). The database needed for the prediction operation was generated from several experiments corresponding with treatment dosages of HANRHA between 0 and 12% at a rate of 0.1%. The results of the stabilization exercise showed substantial development on the soil properties examined, while the prediction exercise showed that ANN outclassed GP in terms of performance evaluation, which was conducted using sum of squared error (SSE) and coefficient of determination (R2) indices. Generally, nanostructuring of the component binder material has contributed to the success achieved in both soil improvement and efficiency of the models predicted.
Energy Loss Calculation of Low Voltage Distribution Area Based on Variational Mode Decomposition and Least Squares Support Vector Machine
Authors: Liu Keyan , Jia Dongli , Zhao Fengzhan , Zhang Qicheng , Hao Shuai , Zhang Shuai
Published: July 2021

In order to improve the accuracy of theoretical energy loss calculation in low voltage distribution area (LV-area), this paper proposes a new prediction method based on variational mode decomposition (VMD) and particle swarm optimization (PSO) least squares support vector machine (LSSVM). Firstly, the main influencing factors of energy loss calculation in LV-area are determined by the grey correlation method, which reflects the data-driven characteristic of the method and ensures the objectivity of the prediction results and the generalization of the calculation model. Secondly, the trend component and fluctuation component are obtained by VMD of daily energy loss series in the LV-area. The variable set of main influencing factors of energy losses is used as the input variable of LSSVM, and the VMD result of the energy loss sequence is used as the output. The theoretical energy loss training and calculation model of LV-area is established. Compared with the traditional calculation model, this model has more accurate calculation accuracy by taking into account the frequency characteristics of energy losses in different frequency bands. PSO is used to optimize the parameters of LSSVM for the purpose of improving the accuracy of LSSVM. Finally, an example of 252 LV-area in a city in northern China is given to verify the validity of the proposed method. The results indicate that the proposed method generates more accurate results.
Causes and Five-Year Proportion of New Irreversible Visual Impairment in Jinshan District, Shanghai, from 2009–2018
Authors: Li Tao , Zhou Xiaodong
Published: July 2021

Purpose. To describe the age distribution and main causes of new registered irreversible visual impairment (VI) and to compare the five-year proportion of VI in Jinshan district, Shanghai, from 2009 to 2018. Methods. The new irreversible VI data were collected in the registry system from the Disabled Persons’ Federation in Jinshan district from January 1, 2009, to December 31, 2018. Age, gender, and causes of VI were included, and the 5-year proportion of VI was calculated. Results. The peak occurrence of blindness occurred in the 50–59 yrs group in 2009–2013 and in the ≥70 yrs group in 2014–2018. The peak occurrence of low vision occurred in the 40–49 yrs group in 2009–2013 and in the 50–59 yrs group in 2014–2018. Myopic macular degeneration (MMD, 15.5%), diabetic retinopathy (DR, 14.3%), and other optic nerve atrophy (ONA, 14.3%) were the three leading causes of blindness in 2009-2013, whereas MMD (21.3%), age-related macular degeneration (AMD, 19.6%), ONA (14.9%) were the three leading causes of blindness in 2014–2018. MMD (39.2%), DR (9.6%), ONA (8.8%) were the three leading causes of low vision in 2009–2013, whereas MMD (38.7%), AMD (23.3%), ONA (7.4%) were the three leading causes of low vision in 2014–2018. The proportions of blindness and low vision caused by AMD were higher in 2014–2018 than those in 2009–2013 (

P
=
0.034

and

P
<
0.001

, respectively). Conclusion. The present study demonstrated an increasing trend in the number of irreversibly visually impaired individuals from 2009 to 2018. More attention should be paid to people with high myopia and old age.
RT-SAD: Real-Time Sketch-Based Adaptive DDoS Detection for ISP Network
Authors: Shi Haibin , Cheng Guang , Hu Ying , Wang Fuzhou , Ding Haoxuan
Published: July 2021

With the great changes in network scale and network topology, the difficulty of DDoS attack detection increases significantly. Most of the methods proposed in the past rarely considered the real-time, adaptive ability, and other practical issues in the real-world network attack detection environment. In this paper, we proposed a real-time adaptive DDoS attack detection method RT-SAD, based on the response to the external network when attacked. We designed a feature extraction method based on sketch and an adaptive updating algorithm, which makes the method suitable for the high-speed network environment. Experiment results show that our method can detect DDoS attacks using sampled Netflowunder high-speed network environment, with good real-time performance, low resource consumption, and high detection accuracy.
Roles of MicroRNAs in Peripheral Artery In‐Stent Restenosis after Endovascular Treatment
Authors: Wang Mo , Zhang Weichang , Zhang Lei , Wang Lunchang , Li Jiehua , Shu Chang , Li Xin
Published: July 2021

Endovascular repair including percutaneous transluminal angioplasty (PTA) and stent implantation has become the standard approach for the treatment of peripheral arterial disease; however, restenosis is still the main limited complication for the long‐term success of the endovascular repair. Endothelial denudation and regeneration, inflammatory response, and neointimal hyperplasia are major pathological processes occurring during in‐stent restenosis (ISR). MicroRNAs exhibit great potential in regulating several vascular biological events in different cell types and have been identified as novel therapeutic targets as well as biomarkers for ISR prevention. This review summarized recent experimental and clinical studies on the role of miRNAs in ISR modification, with the aim of unraveling the underlying mechanism and potential therapeutic strategy of ISR.
Evaluation of Effect of Curcumin on Psychological State of Patients with Pulmonary Hypertension by Magnetic Resonance Image under Deep Learning
Authors: Ma Tingting , Ma Ziyuan , Zhang Xiuping , Zhou Fubo
Published: July 2021

This research aimed to evaluate the right ventricular segmentation ability of magnetic resonance imaging (MRI) images based on deep learning and evaluate the influence of curcumin (Cur) on the psychological state of patients with pulmonary hypertension (PH). The heart MRI images were detected based on the You Only Look Once (YOLO) algorithm, and then the MRI image right ventricle segmentation algorithm was established based on the convolutional neural network (CNN) algorithm. The segmentation effect of the right ventricle in cardiac MRI images was evaluated regarding intersection-over-union (IOU), Dice coefficient, accuracy, and Jaccard coefficient. 30 cases of PH patients were taken as the research object. According to different treatments, they were rolled into control group (conventional treatment) and Cur group (conventional treatment + Cur), with 15 cases in each group. Changes in the scores of the self-rating anxiety scale (SAS) and self-rating depression scale (SDS) of the two groups of patients before and after treatment were analyzed. It was found that the average IOU of the heart target detection frame of the MRI image and the true bounding box before correction was 0.7023, and the IOU after correction was 0.9016. The Loss of the MRI image processed by the CNN algorithm was 0.05, which was greatly smaller than those processed by other algorithms. The Dice coefficient, Jaccard coefficient, and accuracy of the MRI image processed by CNN were 0.89, 0.881, and 0.994, respectively. The MRI images of PH patients showed that the anterior wall of the right ventricle was notably thickened, and the main pulmonary artery was greatly widened. After treatment, the SAR and SDS scores of the two groups were lower than those before treatment (

P
<
0.05

), and the SAR and SDS scores of the curcumin group were lower than those of the control group (

P
<
0.05

). To sum up, the right ventricular segmentation ability of MRI images based on deep learning was improved, and Cur can remarkably alleviate the psychological state of PH patients, which provided a reference for the diagnosis and treatment for PH patients.
Identification of Prognostic Genes in Neuroblastoma in Children by Weighted Gene Coexpression Network Analysis
Authors: Yang Jun , Zhang Ying , Zhou Jiaying , Wang Shaohua
Published: July 2021

Background. Neuroblastoma is a malignant neuroendocrine tumor from the sympathetic nervous system, the most common extracranial tumor in children. Identifying potential prognostic markers of neuroblastoma can provide clues for early diagnosis, recurrence, and treatment. Methods. RNA sequence data and clinical features of 147 neuroblastomas were obtained from the TARGET (Therapeutically Applicable Research to Generate Effective Treatments project) database. Application weighted gene coexpression network analysis (WGCNA) was used to construct a free-scale gene coexpression network, to study the interrelationship between its potential modules and clinical features, and to identify hub genes in the module. We performed Lasso regression and Cox regression analyses to identify the three most important genes and develop a new prognostic model. Data from the GSE85047 cohort verified the predictive accuracy of the prognostic model. Results. 14 coexpression modules were constructed using WGCNA. Brown coexpression modules were found to be significantly associated with disease survival status. Multivariate Cox analysis was performed on genes from univariate Cox regression and Lasso regression analyses using the Cox proportional hazards regression model. Finally, we constructed a three-gene prognostic model: risk score = (0.003812659

∗

CKB) + (−0.152376975

∗

expDST) + (0.032032815

∗

expDUT). The prognosis of samples in the high-risk group was significantly poorer than that of samples in the low-risk group (

P
=
1.225
e
−
06

). The risk model was also regarded as an independent predictor of prognosis (HR = 1.632; 95% CI = 1.391–1.934;

P
<
0.001

). Conclusion. Our study constructed a neuroblastoma coexpressing gene module and identified a prognostic potential risk model for prognosis in neuroblastoma.
Weak-Strong Uniqueness for Compressible Magnetohydrodynamic Equations with Coulomb Force
Authors: He Lianhua , Zhou Yonghui
Published: July 2021

In this paper, we consider the two-dimensional compressible magnetohydrodynamic system with Coulomb force. We apply the method of relative entropy to establish the weak-strong uniqueness property of this system.
Dysregulated Diurnal Cortisol Pattern and Heightened Night-Time Cortisol in Individuals with Bipolar Disorder
Authors: Mukherjee Dahlia , Weissenkampen J. Dylan , Wasserman Emily , Krishnamurthy Venkatesh Basappa , Millett Caitlin E. , Conway Stephen , Saunders Erika F.H.
Published: July 2021

Introduction: Hypothalamic-pituitary-adrenal (HPA) axis dysregulation may contribute to the symptom burden in bipolar disorder (BD). Further characterization of cortisol secretion is needed to improve understanding of the connection between mood, sleep, and the HPA axis. Here, we observe diurnal cortisol patterns in individuals with BD and healthy controls (HCs) to determine time points where differences may occur. Methods: Salivary cortisol was measured at 6 time points (wake, 15, 30, and 45 min after wake, between 2:00 and 4:00 p.m. and 10:00 p.m.) for 3 consecutive days in individuals with symptomatic BD (N = 27) and HC participants (N = 31). A general linear model with correlated errors was utilized to determine if salivary cortisol changed differently throughout the day between the 2 study groups. Results: A significant interaction (F = 2.74, df = 5, and p = 0.02) was observed between the time of day and the study group (BD vs. HC) when modeling salivary cortisol over time, indicating that salivary cortisol levels throughout the day significantly differed between the study groups. Specifically, salivary cortisol in BD was elevated compared to HCs at the 10:00 p.m. time point (p = 0.01). Conclusion: Significantly higher levels of cortisol in participants with BD in the night-time suggest that the attenuation of cortisol observed in healthy individuals may be impaired in those with BD. Reregulation of cortisol levels may be a target of further study and treatment intervention for individuals with BD.
Role of Up-Front Primary Tumor Resection and Tumor Sidedness in the Survival of Synchronous Metastatic Colon Cancer Patients
Authors: van der Kruijssen Dave E.W. , van Rooijen Karlijn L. , Kurk Sophie A. , de Wilt Johannes H.W. , Punt Cornelis J.A. , Vink Geraldine R. , Elias Sjoerd G. , Koopman Miriam
Published: July 2021

Introduction: Uncertainty exists about a possible survival benefit of primary tumor resection (PTR) in synchronous metastatic colon cancer (mCC). Since sidedness of the primary tumor is regarded as an important prognostic factor, our objective was to study the interaction between PTR and sidedness in synchronous mCC. Methods: In this retrospective study, we used data from 2 first-line phase 3 randomized controlled trials (RCTs). A mixed Cox regression model was used to study the multiplicative interaction between PTR and sidedness. We adjusted for age, treatment arm, WHO performance status, number of affected organs by metastases, serum lactate dehydrogenase, and year of enrollment. Results: We found that PTR is associated with better survival in both right-sided (hazard ratio [HR] 0.59 [95% confidence interval 0.42–0.8 2]) and left-sided mCC (HR 0.70 [95% confidence interval 0.52–0.93]). The interaction between PTR and sidedness was not significant (p = 0.45). Conclusion: Our data suggest that the prognostic value of PTR is independent of sidedness. Validation of these results will be performed in ongoing RCTs.
Renal Outcomes of Dialysis-Dependent Acute Kidney Injury in Noncritically Ill Patients: A Retrospective Study
Authors: Esposito Pasquale , Avella Alessandro , Ferrari Fiorenza , Bruno Giancarlo , Libetta Carmelo , Battaglia Yuri , De Silvestri Annalisa , Bianzina Stefania , Rampino Teresa
Published: July 2021

Introduction: Acute kidney injury (AKI) is a common complication among hospitalized patients, potentially affecting short- and long-term clinical outcomes. In this retrospective study, we evaluated renal outcomes in noncritically ill patients who required acute hemodialysis (HD) because of an AKI episode occurring during hospitalization. Methods: Sixty-three hemodynamically stable patients with AKI undergoing acute intermittent HD were included. Kidney function was evaluated at baseline control (pre-AKI), at AKI diagnosis and during the follow-up. According to serum creatinine and the estimated glomerular filtration rate (eGFR), we defined three clinical conditions: renal recovery, different stages of acute kidney disease (AKD), and chronic kidney disease (CKD). Results: Among the 63 patients evaluated, 34 patients (54%) had a history of CKD. Six patients (10%) presented early full renal recovery. HD treatment was stopped in 38 patients (60%), while 25 patients (40%) required maintenance HD. Dialysis-independent patients presented lower comorbidity and higher baseline eGFR and delta creatinine, compared to dialysis-dependent patients. Baseline CKD, previous AKI episodes, and parenchymal causes of AKI were associated with a significant risk of dialysis dependence. At 1-month control, 15 patients (39%) presented AKD stage 0, 6 patients (16%) AKD stage 1, and 17 patients (44%) AKD stage 2–3. At 3-month control, 29 out of 38 patients recovering from AKI (76%) presented CKD. AKD stage was significantly correlated with the risk of CKD development, which, resulted higher in patients with lower baseline eGFR. Conclusions: AKI might represent a risk factor for the development of chronic kidney damage, even in noncritically ill patients.
NFκB1 Dichotomously Regulates Pro-Inflammatory and Antiviral Responses in Asthma
Authors: Menzel Mandy , Akbarshahi Hamid , Mahmutovic Persson Irma , Andersson Cecilia , Puthia Manoj , Uller Lena
Published: July 2021

Asthma exacerbations are commonly triggered by rhinovirus infections. Viruses can activate the NFκB pathway resulting in airway inflammation and increased Th2 cytokine expression. NFκB signaling is also involved in early activation of IFNβ, which is a central mediator of antiviral responses to rhinovirus infection. Using a mouse model, this study tests our hypothesis that NFκB signaling is involved in impaired IFNβ production at viral-induced asthma exacerbations. C57BL/6 wild-type and NFκB1−/− mice were challenged with house dust mite for 3 weeks and were subsequently stimulated with the rhinoviral mimic poly(I:C). General lung inflammatory parameters and levels of the Th2 upstream cytokine IL-33 were measured after allergen challenge. At exacerbation, production of IFNβ and antiviral proteins as well as gene expression of pattern recognition receptors and IRF3/IRF7 was assessed. In the asthma exacerbation mouse model, lack of NFκB1 resulted in lower levels of IL-33 after allergen challenge alone and was associated with reduced eosinophilia. At exacerbation, mice deficient in NFκB1 exhibited enhanced expression of IFNβ and antiviral proteins. This was accompanied by increased IRF3/IRF7 expression and induction of pattern recognition receptor expression. In a human asthma dataset, a negative correlation between IRF3 and NFκB1 expression was observed. NFκB may impair antiviral responses at exacerbation, possibly by reducing expression of the transcription factors IRF3/IRF7. These findings suggest a therapeutic potential for targeting NFκB pathways at viral infection-induced exacerbations.