bluuebunny/crossref_metadata_2025 huggingface dataset:
Delineating the genotypic and phenotypic spectrum of HECW2-related neurodevelopmental disorders
Authors: Acharya Anushree , Kavus Haluk , Dunn Patrick , Nasir Abdul , Folk Leandra , Withrow Kara , Wentzensen Ingrid M. , Ruzhnikov Maura R. Z. , Fallot Camille , Smol Thomas , Rama Mélanie , Brown Kathleen , Whalen Sandra , Ziegler Alban , Barth Magali , Chassevent Anna , Smith-Hicks Constance , Afenjar Alexandra , Courtin Thomas , Heide Solveig , Font-Montgomery Esperanza , Heid Caleb , Hamm J. Austin , Love Donald R. , Thabet Farouq , Misra Vinod K. , Cunningham Mitch , Leal Suzanne M. , Jarvela Irma , Normand Elizabeth A. , Zou Fanggeng , Helal Mayada , Keren Boris , Torti Erin , Chung Wendy K. , Schrauwen Isabelle
Published: July 2021

Background

Variants in HECW2 have recently been reported to cause a neurodevelopmental disorder with hypotonia, seizures and impaired language; however, only six variants have been reported and the clinical characteristics have only broadly been defined.

Methods

Molecular and clinical data were collected from clinical and research cohorts. Massive parallel sequencing was performed and identified individuals with a HECW2-related neurodevelopmental disorder.

Results

We identified 13 novel missense variants in HECW2 in 22 unpublished cases, of which 18 were confirmed to have a de novo variant. In addition, we reviewed the genotypes and phenotypes of previously reported and new cases with HECW2 variants (n=35 cases). All variants identified are missense, and the majority of likely pathogenic and pathogenic variants are located in or near the C-terminal HECT domain (88.2%). We identified several clustered variants and four recurrent variants (p.(Arg1191Gln);p.(Asn1199Lys);p.(Phe1327Ser);p.(Arg1330Trp)). Two variants, (p.(Arg1191Gln);p.(Arg1330Trp)), accounted for 22.9% and 20% of cases, respectively. Clinical characterisation suggests complete penetrance for hypotonia with or without spasticity (100%), developmental delay/intellectual disability (100%) and developmental language disorder (100%). Other common features are behavioural problems (88.9%), vision problems (83.9%), motor coordination/movement (75%) and gastrointestinal issues (70%). Seizures were present in 61.3% of individuals. Genotype-phenotype analysis shows that HECT domain variants are more frequently associated with cortical visual impairment and gastrointestinal issues. Seizures were only observed in individuals with variants in or near the HECT domain.

Conclusion

We provide a comprehensive review and expansion of the genotypic and phenotypic spectrum of HECW2 disorders, aiding future molecular and clinical diagnosis and management.
Diagnostic yield of chromosomal microarray and trio whole exome sequencing in cryptogenic cerebral palsy
Authors: Yechieli Michal , Gulsuner Suleyman , Ben-Pazi Hilla , Fattal Aviva , Aran Adi , Kuzminsky Alla , Sagi Liora , Guttman Dafna , Schneebaum Sender Nira , Gross-Tsur Varda , Klopstock Tehila , Walsh Tom , Renbaum Paul , Zeligson Sharon , Shemer Meiri Lilach , Lev Dorit , Shmueli Dorit , Blumkin Luba , Lahad Amnon , King Mary-Claire , Levy Ephrat Lahad , Segel Reeval
Published: July 2021

Objective

To determine the yield of genetic diagnoses using chromosomal microarray (CMA) and trio whole exome sequencing (WES), separately and combined, among patients with cryptogenic cerebral palsy (CP).

Methods

Trio WES of patients with prior CMA analysis for cryptogenic CP, defined as disabling, non-progressive motor symptoms beginning before the age of 3 years without known cause.

Results

Given both CMA analysis and trio WES, clinically significant genetic findings were identified for 58% of patients (26 of 45). Diagnoses were eight large CNVs detected by CMA and 18 point mutations detected by trio WES. None had more than one severe mutation. Approximately half of events (14 of 26) were de novo. Yield was significantly higher in patients with CP with comorbidities (69%, 22 of 32) than in those with pure motor CP (31%, 4 of 13; p=0.02). Among patients with genetic diagnoses, CNVs were more frequent than point mutations among patients with congenital anomalies (OR 7.8, 95% CI 1.2 to 52.4) or major dysmorphic features (OR 10.5, 95% CI 1.4 to 73.7). Clinically significant mutations were identified in 18 different genes: 14 with known involvement in CP-related disorders and 4 responsible for other neurodevelopmental conditions. Three possible new candidate genes for CP were ARGEF10, RTF1 and TAOK3.

Conclusions

Cryptogenic CP is genetically highly heterogeneous. Genomic analysis has a high yield and is warranted in all these patients. Trio WES has higher yield than CMA, except in patients with congenital anomalies or major dysmorphic features, but these methods are complementary. Patients with negative results with one approach should also be tested by the other.
Cardiovascular responses to physical activity during work and leisure
Authors: Quinn Tyler David , Kline Christopher E , Nagle Elizabeth , Radonovich Lewis J , Alansare Abdullah , Barone Gibbs Bethany
Published: July 2021

Objectives

Recent evidence suggests that occupational physical activity (OPA) is associated with adverse cardiovascular health, whereas leisure time physical activity is protective. This study explored explanatory physiological mechanisms.

Methods

Nineteen males (68% white, age=46.6±7.9 years, body mass index=27.9±5.1 kg/m2) with high self-reported OPA wore activity (ActiGraph and activPAL) and heart rate (HR) monitors for 7 days and an ambulatory blood pressure (BP) monitor on one workday and one non-workday. Mixed effects models compared cardiovascular variables (24-hour, nocturnal, waking and non-work time HR and BP) and nocturnal HR variability (HRV) on workdays versus non-workdays. Additional models examined associations of daily activity (steps, light physical activity (LPA) and moderate-to-vigorous physical activity (MVPA)) with cardiovascular variables. Workday by daily activity interactions were examined.

Results

24-hour and waking HR and diastolic BP as well as non-work diastolic BP were significantly higher on workdays versus non-workdays (p<0.05 for all). However, no difference in systolic BP or nocturnal HR or BP was observed between work and non-workdays (p>0.05 for all). Low-frequency and high-frequency power indices of nocturnal HRV were lower on workdays (p<0.05 for both). Daily steps and LPA were positively associated with 24-hour and waking HR on work and non-workdays. Significant interactions suggested MVPA increases HR and lowers nocturnal HRV during workdays, with the opposite effect on non-workdays.

Conclusions

Cardiovascular load was higher on workdays versus non-workdays with no compensatory hypotensive response following workdays. Daily MVPA may differentially affect ambulatory cardiovascular load and nocturnal HRV on workdays versus non-workdays, supporting the physical activity health paradox hypothesis.
Bilateral optic neuritis as a first presentation of lymph node tuberculosis
Authors: Keshavan Ashvini , McAnena Lisa , Acheson James F , Booth Helen , Plant Gordon T , Khaleeli Zhaleh
Published: July 2021

Tuberculosis (TB) may affect the nervous system in many ways. We describe an immunocompetent teenage girl with lymph node TB who had first presented with bilateral optic neuritis. Detailed history identified features inconsistent with immune-mediated optic neuritis. Several unusual features prompted further investigation, including transient visual obscurations without raised intracranial pressure, prominent disc swelling and absence of laboratory findings to support an immune-mediated cause. Whole body PET/MR imaging identified widespread mediastinal and supraclavicular lymphadenopathy. Despite no known TB contacts, a negative interferon gamma release assay and a normal chest X-ray, a targeted lymph node biopsy confirmed TB.
White matter hyperintensities associate with cognitive slowing in patients with systemic lupus erythematosus and neuropsychiatric symptoms
Authors: Monahan Rory Caitlin , Inglese Francesca , Middelkoop Huub , van Buchem Mark , Huizinga Tom WJ , Kloppenburg Margreet , Ronen Itamar , Steup-Beekman Gerda M , de Bresser Jeroen
Published: July 2021

Objective

To compare cognitive function between patients with different phenotypes of neuropsychiatric systemic lupus erythematosus (NPSLE) and assess its association with brain and white matter hyperintensity (WMH) volumes.

Methods

Patients attending the Leiden University Medical Centre NPSLE clinic between 2007 and 2015 without large brain infarcts were included (n=151; 42±13 years, 91% women). In a multidisciplinary consensus meeting, neuropsychiatric symptoms were attributed to systemic lupus erythematosus (SLE) (NPSLE, inflammatory (n=24) or ischaemic (n=12)) or to minor/non-NPSLE (n=115). Multiple regression analyses were performed to compare cognitive function between NPSLE phenotypes and to assess associations between brain and WMH volumes and cognitive function cross-sectionally.

Results

Global cognitive function was impaired in 5%, learning and memory (LM) in 46%, executive function and complex attention (EFCA) in 39% and psychomotor speed (PS) in 46% of all patients. Patients with inflammatory NPSLE showed the most cognitive impairment in all domains (p≤0.05).

Higher WMH volume associated with lower PS in the total group (B: −0.14 (95% CI −0.32 to −0.02)); especially in inflammatory NPSLE (B: −0.36 (95% CI −0.60 to −0.12). In the total group, lower total brain volume and grey matter volume associated with lower cognitive functioning in all domains (all: 0.00/0.01 (0.00;0.01)) and lower white matter volume associated with lower LM, EFCA and PS (all: 0.00/0.01 (0.00;0.01)).

Conclusion

We demonstrated that an association between brain and WMH volumes and cognitive function is present in patients with SLE, but differs between (NP)SLE phenotypes. WMHs associated with PS especially in inflammatory NPSLE, which suggests a different, potentially more severe underlying pathophysiological mechanism of cognitive impairment in this phenotype.
VEGF-mediated angiogenesis in retinopathy of prematurity is co-regulated by miR-17-5p and miR-20a-5p
Authors: Guo Yan , Du Fen , Tan Yi-Lan , Luo Jun , Xiong Dan , Song Wei-Tao
Published: July 2021

The microRNAs miR-17-5p and miR-20a-5p play important roles on angiogenesis; however, it is arguable whether they regulate the formation of retinal blood vessels in retinopathy of prematurity (ROP). We used a mouse model of oxygen-induced retinopathy (OIR) to simulate the development of retinas in mice suffering from ROP, and the expression levels of miR-20a-5p, miR-17-5p, hypoxia-inducible factor 1-alpha (HIF-1α), and vascular endothelial growth factor (VEGF) were measured by RT-qPCR and Western blotting. Cell proliferation, apoptosis, and angiogenesis in the OIR model mice were measured using MTT assays, flow cytometry, and Matrigel assays, respectively. The interaction between HIF-1α/VEGF and miR-20a-5p/miR-17-5p were further validated using dual-luciferase reporter assays, biotin-labeled RNA-pulldown, and RNA immunoprecipitation (RIP) assays. In our OIR model, retinal angiogenesis in the mice was associated with down-regulation of miR-20a-5p and miR-17-5p, as well as up-regulation of HIF-1α and VEGF. In addition, the miR-20a-5p and miR-17-5p inhibited cell proliferation and angiogenesis through regulating HIF-1α and VEGF in the retinal cells of the OIR model mice. Moreover, it was found that miR-20a-5p and miR-17-5p bind to HIF-1α and VEGF at the 3′UTR, and there was a combined effect between miR-20a-5p and miR-17-5p on the regulation of HIF-1α and VEGF. It is worth noting that miR-17-5p and miR-20a-5p can preferentially regulate HIF-1α, then act on VEGF, thereby affecting the angiogenesis associated with ROP.
On systematic effects in the numerical solutions of the JIMWLK equation
Authors: Calì Salvatore , Cichy Krzysztof , Korcyl Piotr , Kotko Piotr , Kutak Krzysztof , Marquet Cyrille
Published: July 2021

In the high energy limit of hadron collisions, the evolution of the gluon density in the longitudinal momentum fraction can be deduced from the Balitsky hierarchy of equations or, equivalently, from the nonlinear Jalilian–Marian–Iancu–McLerran–Weigert–Leonidov–Kovner (JIMWLK) equation. The solutions of the latter can be studied numerically by using its reformulation in terms of a Langevin equation. In this paper, we present a comprehensive study of systematic effects associated with the numerical framework, in particular the ones related to the inclusion of the running coupling. We consider three proposed ways in which the running of the coupling constant can be included: “square root” and “noise” prescriptions and the recent proposal by Hatta and Iancu. We implement them both in position and momentum spaces and we investigate and quantify the differences in the resulting evolved gluon distributions. We find that the systematic differences associated with the implementation technicalities can be of a similar magnitude as differences in running coupling prescriptions in some cases, or much smaller in other cases.
Guglielmo Marconi, Augusto Righi and the invention of wireless telegraphy
Authors: Leone Matteo , Robotti Nadia
Published: July 2021

One of the major accomplishments of the late nineteenth-century applied physics was, as it is well known, the development of wireless telegraphy by Guglielmo Marconi, future Nobel laureate. In this paper, we will explore what scientific debt, if any, Marconi had toward another Italian physicist, internationally well known for his research on electromagnetic waves: Augusto Righi. This question will be pursued through a close analysis of Marconi’s first patent, of Righi’s scientific correspondence and of the specialized and popular press of the time. At the end of this analysis, which includes a brief survey of Marconi and Righi’s activity as senators of the Kingdom of Italy, we will better appreciate what Marconi took from contemporary scientists, what specific contributions he is responsible for and, ultimately, what Marconi and Righi thought of each other.
Periastron precession due to a Janis–Newman–Winicour wormhole in the weak field limit
Authors: Li Weijun , Yang Bo , Ma Cunliang , Zhou Xia , Feng Zhongwen , He Guansheng
Published: July 2021

The precession effect of periastron for a massive test particle in the spacetime of a Janis–Newman–Winicour wormhole is studied in the weak field limit. Based on the metric of this static and spherically symmetric wormhole in harmonic coordinates, we derive the second post-Newtonian dynamics of the particle. The second-order orbital precession of periastron is then obtained via a post-Newtonian iterative technique under the Wagoner–Will–Epstein–Haugan representation. Our result is found to be consistent with the classical precession effect when the asymptotic scalar charge is dropped.
Influence of insulation paper on the hot spot temperature of oil-immersed transformer winding
Authors: Luo Chuan , Zhao Zhen-Gang , Wang Yu-Yuan , Liang Ke , Zhang Jia-Hong , Li Ying-Na , Li Chuan
Published: July 2021

The oil-immersed transformer is a crucial piece of equipment in the power system. Operating at the specified temperature is necessary to ensure the normal operation of the transformer. The insulation paper on the winding surface has a significant impact on the actual temperature of the transformers, which is often overlooked by researchers. The one-dimensional steady-state heat conduction model of the transformer is established by analyzing the heat diffusion process of winding to transformer oil. Atomic force microscope was used to observe the microsurface structure of insulation paper and copper. According to the experiment, the heat transfer resistance in the series process of heat transfer at [Formula: see text]C is 0.0138 m2 K/W. Space thermal circuit model of transformer is established by thermoelectricity analogy method, and the simulation circuit is optimized according to the boundary conditions set up in the actual environment. The results show that the error of the hot spot temperature is closer to the measured temperature and decreases by 2.5% when considering the thermal resistance of insulation paper.
The Microfoundations of Strategic Entrepreneurship: A Middle Management Perspective
Authors: Wang Ruifang , Gibbons Patrick , Heavey Ciaran
Published: July 2021

Strategic entrepreneurship (SE) has attracted increased research attention, given its dual focus on creating competitive advantage and exploiting new opportunities. While research interest in SE has grown at a rapid pace in the past two decades, understanding of its microfoundations is limited. This conceptual paper contributes to the development of understating from a middle management perspective. It argues that middle managers’ five strategic roles serve as the microfoundations to firm’s SE. It also drills down to explore individual differences as antecedents in shaping these roles. This paper develops a research framework along with fine-grained propositions, aimed to shed light on future research and implications for practice.
Definition and Testing of a Skills Framework to Evaluate the Effect of a Pedagogical Program in Entrepreneurship
Authors: Krémer Florence , Jouison Estèle
Published: July 2021

Our work aims at contributing to research on entrepreneurship pedagogy by designing and testing a skills framework to evaluate the outcomes of pedagogical programs in entrepreneurship. A literature review was conducted to clarify the concept of skills. The first part of this article describes the components of the 17 main entrepreneurial skills identified in the literature (both transversal and specific to entrepreneurship). A post hoc experimental plan was chosen so that the results may be replicated. Data were collected online among business students and 444 completed forms were returned. The survey instrument was tested empirically by comparing the experimental group (265 participants of an entrepreneurship seminar) with the control group (179 non-participants). Results show the value of using a complete evaluation grid when evaluating a pedagogical program in entrepreneurship. Indeed, many transversal skills may evolve positively, not just the skills that are specific to entrepreneurship.
The Decision-Making Environment for the Entrepreneurial Student
Authors: Stephens Simon , Lyons Roisin , Cunningham Isobel
Published: July 2021

Entrepreneurs are a product of their social environment. The manner by which they perceive opportunities; access or process information; and make decisions is, influenced by both social interaction, and their social background. Using insights from Socially Situated Cognition (SSC) theory, that posits one’s social environment can have a normative or informative effect on decision-making process we consider proximal social factors influencing the decision-making processes of student entrepreneurs. We propose that entrepreneurial education, networking, and incubation spaces provide direct information to students to aid entrepreneurial decision-making, and indirect informational cues that are situational, synergistic and omnipresent. Noting the multi-faceted and dynamic nature of the entrepreneurial journey of the student, we explore the potential effect of each of these factors on the student decision-making process. We discuss the implications of this inquiry from a researcher and educator perspective, and note the current challenges faced by student entrepreneurs in a socially distanced educational and entrepreneurial context. It is envisaged that this paper will serve as the basis for further thought and empiricism.
Methods—Understanding Porous Electrode Impedance and the Implications for the Impedance Analysis of Li-Ion Battery Electrodes
Authors: Morasch Robert , Keilhofer Josef , Gasteiger Hubert A. , Suthar Bharatkumar
Published: July 2021

Two of the main factors influencing the performance of Li-ion battery (LIB) electrodes are the kinetic losses due to the charge transfer resistance of the active material (

R

ct

) and the ionic transport resistance in the electrolyte phase within the electrode pores (

R

ion

). Seeking to increase the energy density of LIBs, ever higher active material loadings are applied, resulting in thicker electrodes for which

R

ion

becomes dominant. As electrochemical impedance spectroscopy is commonly used to quantify

R

ct

of electrodes, understanding the impact of

R

ion

on the impedance response of thick electrodes is crucial. By use of a simplified transmission line model (TLM), we simulate the impedance response of electrodes as a function of electrode loading. This will be compared to the impedance of graphite anodes (obtained using a micro-reference electrode), demonstrating that their impedance response varies from purely kinetically limited at 0.6 mAh cm−2 to purely transport limited at 7.5 mAh cm−2. We then introduce a simple method with which

R

ct

and

R

ion

can be determined from the electrode impedance, even under transport limited conditions. Finally, we show how the initially homogenous ionic current distribution across porous electrodes under kinetically limited conditions becomes severely inhomogeneous under transport limited conditions.
Quantitative Characterization of the Microstructure-Property Relationships in Ni and MIEC Nanocatalyst-Infiltrated Ni/YSZ Anodes
Authors: Rix Jillian , Mo Boshan , Pal Uday , Gopalan Srikanth , Basu Soumendra
Published: July 2021

The performance of solid oxide fuel cell (SOFC) anodes infiltrated with different nanocatalysts are compared. In traditional Ni/YSZ cermet anodes, reactions occur at triple phase boundaries (TPBs). Infiltration of Ni nanoparticles increases the TPB density. However, unless the added TPBs created by infiltration have electronically conducting pathways to the percolated Ni in the Ni/YSZ cermet, the added TPBs are not electrochemically active. Different strategies to activate these added TPBs by providing such a conducting pathway, have been explored. These include, spreading the Ni nanoparticles to form a percolating network at temperature, co-infiltration of Ni with GDC, a mixed ionic and electronic conducting (MIEC) phase, and doping the YSZ in the Ni/YSZ cermet to promote electronic conductivity between the Ni nanoparticles. Electrochemical I-V and EIS studies of full and symmetric cells, SEM analysis of fracture cross-sections of infiltrated cells, and FIB-SEM based 3-D reconstruction of the infiltrated microstructures will be discussed.
Highly Efficient SOFC System with Mk35x-Stack Module Operated with Gasified Biomass - HieffBioPower -
Authors: Megel Stefan , Schnetter Jens , Hielscher Sebastian , Kusnezoff Mihails , Dumboeck Ortwin , Weissensteiner Stephan , Sallai Christopher , Hauth Martin , Supancic Klaus , Biedermann Friedrich , Brunner Thomas , Obernberger Ingwald
Published: July 2021

A stationary SOFC system utilizing gas from a biomass updraft gasifier is under development within the project “HiEffBioPower” by MAWERA, BIOS, Bosal, AVL, Calida Cleantech, Fraunhofer IKTS, Wuppertal Institute and University Utrecht (European Union Horizon2020 No. 727330). The system is based on Mk352-CFY-stack with Chromium based (CFY) interconnects and electrolyte supported cells. These stacks are robust, redox stable and demonstrated low degradation rates. The stacks are arranged to modules of eight 30-cell stacks and are electrically connected in series. The stack module was pre-tested at the test rig at IKTS and showed performance in accordance with system requirements. Stationary power points were measured to compare the behaviour of the stack module with the system tests at MAWERA. AVL designed and installed the overall SOFC system (heat exchangers, stack, catalytic afterburner, process control and visualisation) with a nominal capacity of 6 kWel. After shipping all parts of the SOFC system to MAWERA in Hard (AT), the coupling of the biomass gasifier, the gas cleaning unit and the SOFC system was conducted. The system is operated by an automated process control. The highest efforts needed the novel gas cleaning unit, consisting of a high temperature filter, a desulphurisation unit as well as a novel catalytic gas reforming stage developed by BIOS.

The biomass gasifier has been operated with wood chips of different quality. The high tar contents of the product gas make a tar cracking essential to reach a high calorific value of the gas for the SOFC system. The novel gas cleaning system shows good performance and reaches the defined SOFC requirements. The SOFC system developed and operated by AVL reached stable conditions for several days. The operating results of the stack module at lab conditions and at the real system are in a good agreement. The SOFC stack module performance in terms of cell voltages, stack temperature distribution and fuel utilization under biomass reformate fuel will be shown and supported by several simulation to get an overall energy balance. Examples of optimization for several components by CFD simulation and component tests will be given.
Influence of Oxygen Partial Pressure on Cathodic Polarization of LaNiO3/GDC Composite Cathode
Authors: Namioka Tomoaki , Hirota Tomohisa , Hashimoto Shin-ichi , Itoh Hibiki
Published: July 2021

LaNiO3/GDC composite is one of the potential cathodic materials for intermediate temperature SOFCs. In order to evaluate its electrochemical performance, influence of oxygen partial pressure on cathodic polarization is examined with an electrolyte supported symmetric cell and a frequency response analyzer. An electrolyte disk made of GDC is used for the electrochemical symmetric cell. The operating temperature was controlled from 773K to 1073K, and the partial pressure was controlled between −4 < log(pO2) atm < 0 in this study.

Polarization resistance increased with decreasing oxygen partial pressure at any temperature. In addition, the characteristic frequency (the summit frequency) of the impedance arc decreased with decreasing oxygen partial pressure. In order to search for the reaction mechanism, the rate-determining step approximation is applied to the experimental results. As a result, a rate-determining step is not dissociative adsorption of oxygen, but apparent oxygen reduction (charge transfer) reaction at temperature in the range from 773K to 973K. However, activation energy of the interfacial conductivity which is a reciprocal of polarization resistance is lower than 100 kJ/mol. Therefore, the rate-determining step is presumably a surface diffusion step, which is a migration step of dissociative oxygen from active point on the LaNiO3 surface to double phase boundary. At 1073K and higher oxygen partial pressure condition, the rate-determination step is still apparent oxygen reduction (charge transfer) reaction. Whereas at 1073K and lower oxygen partial pressure condition, the rate-determining step may be dissociative adsorption of oxygen.
Nanostructuring and Electrochemical Performance of Nb Doped La0.7Sr0.3Co1.XNbxO3-
δ (LCSN) Perovskites for Solid Oxide Fuel Cells
Authors: Dhongde Vicky , Tiwari Pankaj , Anjum Uzma , Basu Suddhasatwa , Haider Mohammad Ali
Published: July 2021

For solid oxide fuel cells (SOFCs), the electrode fabrication with the electrolyte showing a good thermal expansion coefficient (TEC) match at high temperatures is considered a key element in deciding upon the potential of a candidate electrode material. Here, in this work a Nb doped perovskite La0.7Sr0.3Co0.95Nb0.05O3-
δ (LCSN) material is tested for the desired properties of a SOFC cathode. The results are showing improved (TEC) by about 28% for the temperature range of 200 - 2100 K and an increase in ionic conductivity by 19% at 873 K as compared to the base material, La0.7Sr0.3CoO3--
δ (LSC). The material is further fabricated in the form of a nanostructured thin-film electrode using a pulse laser disposition system with thickness varying from 50 nm to 100 nm on a GDC electrolyte. The impedance of the electrode in a symmetric cell is observed to vary with the thickness, suggesting oxygen anion transport, limiting the electrode performance.
Machine Learning Tools Set for Natural Gas Fuel Cell System Design
Authors: Wang Dewei , Bao Jie , Xu Zhijie , Koeppel Brian , Marina Olga A , Noring Alexander , Zamarripa-Perez Miguel , Iyengar Arun , Eggleton Erica , Schwartz Daniel T. , Burgard Anthony , Miller David
Published: July 2021

This study is focusing on leveraging the system design tools set for next-generation solid oxide fuel cell (SOFC) based natural gas fuel cell (NGFC) system. Conventionally, system design and optimization of NGFC systems rely heavily on traditional reduced order model (ROM) techniques and designers’ experience level. For overcoming the technical barriers of system design, multiple multi-physics models and machine learning (ML) tools have been utilized to automate the conceptual design process and enhance the reliability of solutions for the NGFC system. The proposed tools set includes a physics-informed ML tool for automated ROM construction that leverages advances in deep neural networks to significantly reduce ROM prediction error for the NGFC power island compared to traditional approaches. The constructed physics-informed ML ROM can be used in system design and optimization tools set Institute for the Design of Advanced Energy Systems (IDAES) Process Systems Engineering (PSE) framework. The tools set also provides user-friendly graphic user interface built within Jupyter Notebooks, and the whole tools set is open-source public available.
Optimization of SOFC Electrode Microstructures with Long Term Performance Modeling and Machine Learning
Authors: Epting William K , Lei Yinkai , Mason Jerry H , Abernathy Harry W. , Kalapos Thomas , Hackett Gregory A
Published: July 2021

Performance degradation over time is a major barrier to the commercialization of solid oxide fuel cells (SOFCs). A major driver of this degradation is grain coarsening in the 3D microstructure of the porous, composite electrodes. The rate and extent of this microstructural degradation depends on the initial microstructure itself, raising the question of whether an optimal electrode microstructure can be determined for long-term performance. The high dimensionality of parameters that determine the initial microstructure makes parametric optimization challenging. In this work, we present a fully resolved 4D model for simulating microstructural and performance changes over 1,000 hours of cell operation by combining a phase-field coarsening model with spatially resolved microstructural analysis and continuum-level multiphysics performance modeling. The integrated model framework was run in a highly parallelized fashion to simulate the long-term performance of hundreds of LSM-YSZ cathodes and Ni-YSZ anodes. These electrode microstructures were synthetically generated to intentionally span 11 independent initial microstructural parameters. The results of the long-term performance model included electrochemical performance every 100 hours throughout the entire 1,000 hours of operation. Together with a novel figure of merit that accounts for both the initial and long-term performance, this high-dimensional bank of results was used to train a machine learning regression model. The machine learning model was trained to predict the long term performance based on the 11 independent initial microstructural parameters, allowing interpolation to values not included in the fully resolved models, as well as a more robust analysis of each parameter’s influence in this highly dimensional parameter space. A SHAP analysis [1] was performed on the trained machine learning model to determine the relative impact of each of the 11 independent initial microstructural parameters. This demonstrated that, for example, the LSM/YSZ ratio was the most impactful parameter in the cathode microstructure, with lower LSM/YSZ ratios generally leading to more energy produced over the cell’s lifetime. The fully trained model and SHAP analysis are also able to make specific recommendations for changes that would improve existing electrodes, providing a valuable tool for SOFC electrode developers and manufacturers.

[1] S. M. Lundberg, S-I. Lee. A Unified Approach to Interpreting Model Predictions. NIPS 2017.

Figure 1
Elementary Reaction Kinetic Model of an Anode-Supported Syngas Fueled Solid Oxide Fuel Cell Considering the Carbon Deposition Effect
Authors: Zhang Ruiyu , Wang Yuqing , Shi Yixiang , Wang Yinan , Cao Haishan
Published: July 2021

A one-dimensional transient elementary reaction kinetic model of an anode supported solid oxide fuel cell (SOFC) fueled with syngas is developed considering the carbon deposition effect. This model incorporates the coupling effect of heterogeneous elementary chemical and electrochemical reactions, the electrode microstructure and the charge and mass transport processes. The degradation process of the Ni/YSZ anode is considered by a carbon formation mechanism. The model is validated by experimental electrochemical impedance spectra and the simulation results agree reasonably well with the experimental data. The numerical results of carbon deposition simulation indicate that the fuel cell performance and the degradation progress are influenced significantly by the operation temperature and gas compositions. The surface carbon deposition can be decreased by increasing the operating temperature. And the degradation effect can be lessened by reducing carbon dioxide, methane or carbon monoxide in the fuel.
Investigation of the Glass-Ceramic Sealants in SOFC Stacks
Authors: Tan Chao , Han Minfang , Li Haibin , Song Wenwan , Xia Yunfeng
Published: July 2021

The stack sealing is one of the most important factors in planar solid oxide fuel cell (pSOFC) applications. Two sealing approaches were used for the short stacks working under practical conditions, which are rigid bonded sealing with SiO2-BaO-based glass sealant and compressive sealing with ZrO2-based ceramic gasket. The prepared glass was characterized by inductively coupled plasma mass spectrometry (ICP-MS), scanning electron microscopy (SEM), X-ray diffraction (XRD), and dilatometry to determine its component and structural and thermal properties. Once the stack system shut down, the bubble test was used to detect and locate the leak of the stack. Then post-test characterization was conducted to analyze the failure of the sealing. SEM-EDS and XRD were used to analyze the microstructure and the crystallization of the sealant inside and its interface with the interconnect. It was observed that the crystal was formed inside the glass sealant, which strengthened the material. Good adhesion and chromium diffusion were found between the glass sealant and the metal interconnect. Moreover, the lose the sealing glass under overheating was found close to the fuel inlet, which was suggested to lead to the failure of the stack. For the ZrO2-based ceramic sealing, the crack was observed inside the sealant and the airway was obstructed by the sealing material under the compressive force. In summary, the glass sealing was more controllable than the compressive ceramic gasket. However, the glass sealant should be protected from local overtemperature.
Projections for Solid Oxide Electrolysers for Water Electrolysis
Authors: Vora Shailesh , Williams Mark
Published: July 2021

It is shown that lowering area specific resistance (ASR) should lead to lower capital cost, CAPEX, and also to the lowest possible electrical power consumption per hydrogen production rate, OPEX. Based on simple correlations, the CAPEX of the solid oxide electrolysis cell (SOEC) stack could expect to be lowered by 25 percent. In terms of size this low-ASR SOEC stack obviously has the potential to be significantly smaller. Building off the DOE’s progress with SOFC, low-ASR SOEC and SOFC’s are possible with techniques such as sputtering and Atomic Layer Deposition (ALD). This is truly remarkable in that the low per kilowatt SOEC stack cost and low power consumption may make the SOEC an important economically viable SO manifestation.
(Plenary) Update on the SOFC Program at the DOE’s National Energy Technology Laboratory
Authors: Vora Shailesh , Williams Mark , Jesionowski Gary
Published: July 2021

The Solid Oxide Fuel Cell (SOFC) Program, managed by the U.S. Department of Energy (DOE) Office of Fossil Energy (FE) and administered by the FE’s National Energy Technology Laboratory (NETL) is currently developing low-cost SOFC power generation systems. SOFC power systems have the potential to achieve greater than 60 percent efficiency. The SOFC’s operating temperature is lower than combustion-based processes and precludes NOx formation; there are near-zero emissions of CO2, criteria pollutants, and particulates. Furthermore, SOFC power systems require approximately one-third the amount of water relative to conventional combustion-based power systems. The Program includes the testing of SOFC with natural gas in distributed applications, including data centers. In addition to SOFC, there are several projects on various aspects of high temperature solid oxide electrolysis cell (SOEC) for electrolysis of water. The development of efficient systems for hydrogen production is very interesting, especially when supplementary heat is provided from solar or other waste heat sources such as nuclear or coal power plants.
Performance and Stability of Solid Oxide Cell Stacks in CO2-Electrolysis Mode
Authors: Thaler Florian , Fang Qingping , de Haart Ute , De Haart L. G. J. (Bert) , Peters Ralf , Blum Ludger
Published: July 2021

Compared to low temperature electrolysis techniques, solid oxide cell (SOC) technology attracts growing attention in Power-to-X scenarios using renewable energies due to its high efficiency, reversibility and the possibility of converting CO2 and H2O simultaneously into syngas, a chemical precursor for synthetic fuels or intermediates such as methanol. Furthermore, SOCs can also be operated in CO2-electrolysis mode to produce pure CO, which is in great demand for chemical and steel industry. Based on the previous experience on fuel cell, steam- and co-electrolysis operation, the electrochemical performance and durability of planar fuel electrode supported SOC stacks developed in JÜLICH have been investigated with the focus on CO2-electrolysis. The current-voltage characteristics and electrochemical impedance spectroscopy as well as constant current operation for a longer operating time have been performed in both CO2 and co-electrolysis mode. The main aim of these investigations was to gain insights in the electrochemical processes and limitations of the currently used electrodes during CO2-electrolysis and to understand the general degradation mechanisms of the cells under different conditions. With state-of-the-art cells, the stack can be operated at 800 °C with a current density of -1000 mA cm-2 below cell voltages of 1.4 V in a CO2/CO (1:1) mixture. Based on the findings so far, some promising approaches with respect to optimization of fuel electrode microstructure and reaction kinetics to increase performance and durability of the cells under CO2-electrolysis operation are discussed.
1MW-Class Solid Oxide Electrolyser System Prototype for Low-Cost Green Hydrogen
Authors: Harman Jonathan , Hjalmarsson Per , Mermelstein Joshua , Ryley Joshua , Sadler Harry , Selby Mark
Published: July 2021

Ceres has developed a novel and highly differentiated SteelCell™ solid oxide fuel cell technology based upon the use of thick-film ceramics deposited upon a ferritic stainless-steel substrate, using doped ceria as the predominant oxygen-ion conducting ceramic within the cell. The use of ceria allows operation of the SteelCell at lower temperatures (500 - 620 °C) than conventional SOFCs, and the use of a metal support allows much greater mechanical robustness and lower production cost than is typically the case with a planar ceramic SOFC, whilst maintaining the high volumetric power density typical of planar SOFCs.

Ceres Power are now qualifying their SteelCell™ technology for use in steam electrolysis operation with encouraging results. Tests suggest that functional electrochemical and physical processes of the SteelCell are equally efficient in SOFC and SOEC mode meaning there is no major difference in the area specific resistance and degradation within the nominal operating space.

As a next step, the development of a 1MW-class Solid Oxide Electrolysis (SOEL) system is proposed that offers a path to green hydrogen production costs of <$2/kgH2 with equally compelling capital equipment costs enabled by the SteelCell technology. One of the clear advantages of solid oxide electrolysis systems is the ability to thermally integrate with industrial processes such as steel, ammonia and e-fuels production. Integration with existing low pressure “waste” steam feeds available at industrial plants combined with available high grade heat streams may enable system efficiencies of greater than 90% to be achieved. A study of predicted system efficiencies and associated techno-economics of green hydrogen production under various industrial use cases is presented.

The first-of-a-kind 1MW-class Solid Oxide Electrolysis system under consideration will be packaged within a 40ft ISO shipping container and is expected to produce approximately 600 to 800kg of green hydrogen per day. The system will be made up of a number of Electrolysis Cell Modules (ECM). Each ECM will contain an array of Ceres’ standard Gen1B stacks along with hot balance of plant components such as heat exchangers and heaters. This modular approach allows each module to be constructed and tested prior to installation at the demonstration site. It also allows for a high degree of fault tolerance and redundancy that is particularly valuable for prototype systems. Furthermore, it also enables a distributed supply chain to be developed for various elements up and down the system structure.

Finally, a roadmap to the first commercial SOEL systems is presented setting out predicted system CapEx costs, hydrogen production costs and possible arrangements for systems in the 100+ MW range.
Lessons Learned from Operating a Solid Oxide Electrolysis Cell at 1.25 a/cm2 for One Year
Authors: Chen Ming , Tong Xiaofeng , Ovtar Simov
Published: July 2021

Solid oxide electrolysis cells (SOECs) convert electrical energy to chemical energy stored in H2 and/or CO and has a great potential to become a key enabling technology in the transition towards renewables. The key challenges for the successful commercialization of SOEC are the limited long-term durability and cost. To ensure high production rate and hence reduce the investment cost, operation at high current densities needs to be considered. Conventional Ni/yttria stabilized zirconia (YSZ) fuel electrode supported SOEC cells demonstrate acceptable long-term durability when operated at below 1 A/cm2, with a number of tests running for years. These cells suffer however severe degradation when operated at above 1 A/cm2, where the major degradation phenomena are reported to be delamination of the oxygen electrode, crack formation in the YSZ electrolyte, depletion of Ni in the active Ni/YSZ electrode, deterioration of the Ni-YSZ interface, and formation of ZrO2 nano-particles on Ni surface. A large part of the cell resistance increase is associated with the Ni/YSZ electrode. By introducing Ce0.8Gd0.2O2-
d (CGO) nanoparticles into the Ni/YSZ electrode via solution infiltration, we were able to reduce the cell degradation (evaluated based on cell voltages of 0-1000h) from 699 mV/1000h to 66 mV/1000h when operating the cells at 800 oC and 1.25 A/cm2. The CGO nano-particles facilitate the steam splitting reaction at the Ni/YSZ triple phase boundaries (TPB), reduce the electrode polarization and effectively mitigate the microstructural deterioration typically seen in the non-modified Ni/YSZ electrodes. The remaining 66 mV/1000h degradation is mainly associated with formation of a poorly conducting CeAlO3 phase, which is a reaction product between Al2O3 as the sintering aid and the CGO particles on the Ni grains. An effort to break down the CeAlO3 phase was explored, though not successful. Testing the cell with modified Ni/YSZ electrode was extended to one year. A steam supply failure at 4000 h caused certain damage to the cell and resulted in a higher degradation rate in the second half of the one-year test. A counter-balance strategy was successfully tried out by increasing the cell operating temperature to 830 oC eventually. The test was successfully terminated after reaching one year, with cell voltages of 1124 and 1468 mV at the beginning and end of the test, corresponding to an average degradation rate of 40 mV/kh. The current work shows high potential for modifying conventional SOEC cells for use in high current density electrolysis applications.
Development of Highly Efficient Composite Electrodes, CuFe2O4-La(Sr)Fe(Mn)O3, for High-Temperature Co-Electrolysis of CO2-Steam
Authors: Wu Kuan-Ting , Ishihara Tatsumi
Published: July 2021

Solid oxide electrolyzer is expected to be an energy storage device using renewable energy to produce useful fuels. Recently there are strong interests on co-electrolysis of CO2-H2O for producing H2/CO syngas, and even for directly producing liquid fuel or hydrocarbon feedstocks. Further increase in activity and stability of the fuel electrode are required for practical application. In this study, CO2 and CO2-H2O electrolysis were investigated using CuFe2O4 (CFO), La0.6Sr0.4Fe0.8Mn0.2O3 (LSFM) and their composites as cathodes. LaGaO3 based oxide was used for electrolyte and Ba0.6La0.4CoO3 was used for anode. It was found that mixing CFO and LSFM was effective for remarkable improvement of the cell performance in co-electrolysis. Effect of varying CO2/H2O ratio in feed gas was also investigated and the product was always enriched with H2 in comparison with the preset CO2/H2O feed gas due to water-gas-shift reaction (WGS reaction, CO + H2O → CO2 + H2). Since the chemical equilibrium of WGS is thermodynamically preferred to H2 production as decreasing operating temperature, temperature dependence of the co-electrolysis performance using CFO-LSFM composite cathode was also studied. The results indicate that the electrolysis performance was decreased, while the H2 product was increased with decreasing operation temperature. However, considering the cell durability, lowering the operating temperature or the applied electrolysis current density (or working voltage) would be preferable. Degradation of electrolysis performance was also discussed by impedance analysis. Overall, the use of the composite oxides as cathode gives very promising electrochemical performance achieved with excellent Faraday’s efficiency (> 95% of theoretical value), operation stability and reversibility in co-electrolysis.