bluuebunny/crossref_metadata_2025 huggingface dataset:
System Analysis of a 100kW Internal Combustion Engine (ICE) Solid Oxide Fuel Cell (SOFC) Hybrid Configuration
Authors: Colón Rodríguez José , Harun Nor Farida , Zhou Nana , Sabolsky Edward , Tucker David
Published: October 2020

Due to the intermittent nature of the renewable power plants and the rigid operation of existing plans, the need for flexible power production is eminent. Hybrid energy systems have shown potential for flexible power production capable to fulfill the power demands and maintain the efficiency. This work studies different design cases of a 100kW Internal Combustion Engine (ICE) and Solid Oxide Fuel Cell (SOFC) hybrid system.

Anode off-gas from the fuel cell stack provided the chemical energy to run the ICE. Heat management of the anode exhaust was considered to attain the operational limits of the ICE in the present configuration. A turbocharger was used to deliver the necessary air flow for both the fuel cell stack and the engine. A series of 25 design cases were chosen to analyze the performance and the potential flexibility of this cycle. The 25-design points resulted from a matrix composed of the variation of fuel utilization and reformer operating temperature, ranging from 70% to 90% and 600K to 1000K, respectively. At each design point, hardware was re-sized to match the desired conditions.

The cycle performance and fuel cell distributed profiles are discussed in this paper. It is discovered that the system efficiency increases as the fuel utilization increases following a nearly linear behavior. The highest efficiency attained is 62% at a reformer operating temperature of 800K and a 90% fuel utilization. The minimum external fuel required to maintain turbocharger in operation decreases with the increase on the reformer temperature. Power contribution between ICE and SOFC follows a linear behavior closely overlapping each trend at different reforming operational temperatures. The impact of external reforming and internal on-anode reforming is also discussed. It is found that there is an optimal balance between the external and internal reforming. The optimal methane content in this work is shown to be around ∼18 vol%.
A Comprehensive Framework for Distributed Energy Resource Aggregators
Authors: Campbell Nicolas A. , Peinado-Guerrero Miguel A. , Phelan Patrick E. , Villalobos Jesus R.
Published: October 2020

An operational framework is proposed for managing aggregated distributed energy resources (DERs). Currently, aggregators partake in the energy market with minimal coordination or exchange of information with the concerned parties. In particular, demand response (DR) has yet to offer its potential value to the grid. It continues to be utilized as a bulk service for peak-shaving, served with little regard or accountability of the additional effects it brings. This has led to numerous issues surrounding DR events, mainly concerning the distribution system. In both practice and literature, there lacks a structured method for aggregators to operate optimally while addressing the issues observed. Most of the research found in literature pertains to a singular problem, for example, aggregating electric vehicles (EV), optimal bidding strategies, optimal scheduling, and congestion management using DR. The integration of these large concepts is not found in literature but is important in understanding the practical effects additional technical and financial constraints have on finding a practical, close-to-optimal solution. The framework proposed is comprehensive, containing all the components believed to be necessary for an aggregator to operate with respect to the distribution constraints. It is also conceptual and meant to emphasize the benefits the individual components and the complete framework offer.
Digitalisation of Biomass Exploration: A Case Study of Biomass Feedstock Classification
Authors: Olatunji Obafemi O. , Madushele Nkosinathi , Adedeji Paul A. , Akinlabi Stephen
Published: October 2020

Biomass is one of the renewable energy (RE) sources with high prospects in the clean energy strata. The diversity of its application and sources have made digitalisation of its exploration presents an array of attractive opportunity to deploy different categories of biomass in a manner that mitigates climate change, advances economies and reduces power dependency. This study discusses the drivers of digitalisation in bioenergy exploration with the associated opportunities and challenges along the bioenergy value chain. As proof of concept, a case study based on the intelligent classification perspective of digitalisation of biomass was discussed. Two classifiers: Sparse Random Error-Correcting Output-based Support Vector Machine (SRECO-SVM) and Euclidean distance-based k-Nearest Neighbour (KNN-EUM) were elaborated while the procedures for the model development were highlighted. Relevant performance indices were applied to evaluate the models developed. Most significantly, the Accuracy, Sensitivity, Specificity were 0.77, 0.81, 0.97 respectively for SRECO-SVM at the computational time (CT) of 20.41 secs while 0.55, 0.56, 0.96 respectively were reported for KNN-EUM at the computational time (CT) of 20.40 secs. Some other composite metrics, which include G-means, F1-score, Mathews correlation coefficient (MCC), Discriminant power (DP) were reported. On the overall, a synergistic relationship is needed between the data analytics, artificial intelligence and other blockchain technologies in order to unleash the full benefits of digitalisation.
Numerical Investigation of Heat Transfer Characteristics of Different Nanoparticles Using Modified Eulerian-Eulerian Model
Authors: Hussain Muzafar , Tahir Shahbaz
Published: October 2020

Nanofluids are widely adopted nowadays to enhance the heat transfer characteristics in the solar applications because of their excellent thermophysical properties. In this paper, a modified Eulerian-Eulerian model recently developed based on experiments was validated numerically to account for the deviations from the experimental data. The modified Eulerian-Eulerian model is compared with the single-phase model, Eulerian-Eulerian models for TiO2-water at different operating conditions and deviation from the experimental data for each of the model was documented. However, the modified Eulerian-Eulerian model gave much closer results when compared to the experimental data. For the further extension of work, the modified Eulerian-Eulerian model was applied to different nanofluids in order to investigate their heat transfer characteristics. Three different nanoparticles were investigated namely Cu, MgO, and Ag and their heat transfer characteristics is calculated based on the modified Eulerian-Eulerian model as well as the single-phase model for the comparison. For lower values of Reynolds numbers, the average heat transfer coefficient was almost identical for both models with small percentage of error but for higher Reynolds numbers, the deviation got larger. Therefore, single-phase model is not appropriate for higher Reynolds numbers and modified Eulerian-Eulerian model should be used to accurately predict the heat transfer characteristics of the nanofluids at higher Reynolds numbers. From the analysis it is found that the Ag-water nanofluid have the highest heat transfer characteristics among others and can be employed in the solar heat exchangers to enhance the heat transfer characteristics and to further improve the efficiency.
Micromixers and Hydrogen Enrichment: The Future Combustion Technology in Zero-Emission Power Plants
Authors: Hussain Muzafar , Abdelhafez Ahmed , Nemitallah Medhat A. , Habib Mohamed A.
Published: October 2020

The stable and flexible micromixer (MM) gas-turbine technology is coupled with hydrogen (H2) enrichment to present an oxy-methane combustor that can sustain highly diluted flames for application in the Allam cycle for zero-emission power production. MMs have never been tested under oxy-fuel conditions, which highlights the novelty of the present study. The operability window was quantified over ranges of fuel hydrogen fraction (HF) and oxidizer oxygen fraction OF. The MM showed superior stability, allowing for reducing OF down to 21% (by vol.) without H2 enrichment, which satisfies the dilution requirements (23%) of the primary reaction zone within the Allam-cycle combustor. By comparison, swirl-based burners from past studies exhibited a ∼30% minimum threshold. Enriching the fuel with H2 boosted flame stability and allowed for reducing OF further down to a record-low value of 13% at HF = 65% (by vol.) in fuel mixture. Under these highly diluted conditions, the adiabatic flame temperature is 990°C (1800°F), which is substantially lower than the lean blowout limit of most known technologies of lean premixed air-fuel combustion in gas-turbine applications. The results also showed that H2 enrichment has minimal effect on the adiabatic flame temperature and combustor power density (MW/m3/atm), which facilitates great operational flexibility in adjusting HF to sustain flame stability without influencing the Allam cycle peak temperature or affecting the turbine health. MM combustion with H2 enrichment is thus a recommended technology for controlled-emission, fuel/oxidizer-flexible combustion in gas turbines.
Building Energy Prediction Using Artificial Neural Networks (LSTM)
Authors: Goswami Sankhanil
Published: October 2020

Modern buildings account for a significant proportion of global energy consumption worldwide. Therefore, accurate energy use forecast is necessary for energy management and conservation. With the advent of smart sensors, a large amount of accurate energy data is available. Also, with the advancements in data analytics and machine learning, there have been numerous studies on developing data-driven prediction models based on Artificial Neural Networks (ANNs). In this work a type of ANN called Large Short-Term Memory (LSTM) is used to predict the energy use and cooling load of an existing building. A university administrative building was chosen for its typical commercial environment. The network was trained with one year of data and was used to predict the energy consumption and cooling load of the following year. The mean absolute testing error for the energy consumption and the cooling load were 0.105 and 0.05. The percentage mean accuracy was found to be 92.8% and 96.1%. The process was applied to several other buildings in the university and similar results were obtained. This indicates the model can successfully predict the energy consumption and cooling load for the buildings studied. The further improvement and application of this technique for optimizing building performance are also explored.
HRSG Fleet Integrity Management: Lessons Learned From the Field
Authors: Fabricius Andreas , Malloy James , Taylor Mark , Jackson Peter , Moelling David
Published: October 2020

This paper presents key lessons learned from hundreds of field missions for assessing the condition of HRSGs at sites around the world. These involved field inspections, root cause of failure analyses and performance assessments on HRSGs of nearly every design, fuel type and operating mode. Statistics on degradation and failure risk areas are presented. Analysis techniques used in both preparing for field work and in assessing field examination results are also discussed. Trends in the evolution of the principal damage mechanisms over the years are examined, and predictions of future problem areas are considered with a view to guiding asset management actions. The impact on HRSG integrity of changes in unit designs, such as the move to flexible operation in response to the increasing contribution from renewables, is also assessed, and likely future trends are outlined. The use of qualitative and quantitative risk-based methods is also discussed and compared to the use of condition-based inspection methods as a basis for a fleet wide management strategy. A case study including a large IPP with several generating assets in its portfolio is presented and the most cost-effective method with respect to current corporate strategy is discussed. Recommendations for fleet management strategies are made.
Optimization and System Identification of a Variable Pico-Scale Hydro Turbine for Pressure Regulation
Authors: Yu Shi Miao , Ko Youngmok , Hu Han , Seo Jun , Bilton Amy M.
Published: October 2020

Recent studies from the European Commission estimate that more than 20% of global energy is consumed by pumping systems. Significant research has focused on increasing pump efficiency to lower energy consumption; however, few have looked at the energy lost in use of pressure regulating devices (PRDs). This paper proposes a novel pico-scale hydro turbine that could effectively replace PRDs and generate power while regulating pressure. The proposed hydro turbine has an outer diameter of 4″ and a total length of 5.4″. The turbine uses 14 rotating guide vanes and is attached to a generator with a variable load. To maximize power recovery and pressure control range of the turbine, a non-dominated sorting genetic algorithm was used for multi-objective geometry optimization. Then, to build a dynamic model for control system design, parameter identification was conducted using a Gaussian process surrogate model and stochastic search algorithms: particle swarm optimization and genetic algorithm. The optimized turbine showed good agreement between simulated and experimental results and achieved a power output of 120 W, pressure drop range of 6 to 27 psi, and maximum hydraulic efficiency of 75% at the rated flow rate of 27 GPM. The optimized turbine shows the potential of pico-turbines for pressure regulation.
A Review of Cryogenics Applications for Power and Energy
Authors: Rehman Wajiha , Farhan Muhammad , Rehman Fatima
Published: October 2020

Cryogenic technologies use cryogens such as natural gas, nitrogen, helium, hydrogen, argon, and oxygen as main working fluids. These cryogenic technologies and cryogens are emerging in the fields of energy storage, power generation, and eco-friendly fuels. Recently, researchers have proposed to integrate cryogenic systems with power generation systems including Nuclear power plants and wind turbines, to store surplus energy during the off-peak hours and use it during peak hours. The basic idea is to convert air or some other cryogen into liquid during the off-peak hours and expand it during the peak hours to run turbines. Whereas in the shipping industry; LNG is being considered as an alternative fuel to gasoline to meet the future emissions criteria of IMO. LNG not only reduces the vessel’s emissions but it is also cheaper than heavy fuel oils. As every technology has some pros and cons, the efficiency of cryogenics power generation systems is low; about 25%, but work is being done to improve its efficiency and to find alternative applications.

This article discusses the applications, advantages, and drawbacks of cryogenics technologies and fuels for energy generation and storage applications. It also focuses on the challenges which are being faced by this technology and possible ways to overcome them.
HERON As a Tool for Light Water Reactor Market Interaction in a Deregulated Market
Authors: Talbot Paul W. , Gairola Abhinav , Frick Konor , Rabiti Cristian
Published: October 2020

This paper reports the development of HERON (Holistic Energy Resource Optimization Network), a newly-developed RAVEN (Risk Analysis Virtual ENvironment) plugin for grid and capacity optimization, to technoeconomic analysis in a deregulated market. A short description of the HERON plugin is provided, and the release process is described. HERON as a plugin enables RAVEN to perform stochastic technoeconomic analysis of grid-energy systems in a generic approach. The primary function of HERON is to generate the complex RAVEN workflows necessary to optimize component capacities under stochastic systems. HERON is capable of analyzing systems with complex components transferring a variety of commodities, including production components and varied markets. HERON is capable of optimizing high-resolution dispatch for such systems and guiding stochastic optimization algorithms in RAVEN for finding optimal component capacities. In particular, this document demonstrates the application of HERON to systems with deregulated markets. A system including a hyrdogen market, an electricity market, hydrogen storage, a hydrogen producer, and a nuclear power plant is considered. Stochastic histories for electricity prices at the electricity market are employed to perform stochastic analysis for ideal sizing of the hydrogen production facility and hydrogen storage unit. The impact of hydrogen market price and volatility of electricity price are also shown.
Adjusting the Levelized Cost of Energy for Different Rates of Compensation for Solar Generation: A Case Study
Authors: Schwarz Peter , Goudarzi Navid , Camadan Ercument
Published: October 2020

The levelized cost of energy (LCOE) was developed for conventional, non-renewable energy sources, and can be misleading for renewable sources. The intermittent nature of renewable energy resources requires further refining the LCOE definition to prevent overvaluing renewables. Utilities must consider revenues as well as costs in comparing renewables to each other, as well as to conventional, non-renewable fuels. This paper explores the utility net revenues from solar energy — revenues from customer grid purchases net of payments made for solar generation by the customer exported to the utility — under three rate alternatives: Net Metering, Net Purchasing, and Gross Metering. Using individual customer data from Austin Energy for solar customers for the year of 2018, the net revenues to the utility under these three mechanisms were studied for two cases: increasing block rates and flat rates. The results demonstrate that even though the levelized cost of solar adoption is unaffected by the choice of rate, solar adoption by the utility is generally most favorable under gross metering, and least favorable under net metering. Moreover, the outcome can differ on whether the utility uses flat rates or increasing block rates, and on the customer’s level of consumption. This work provides a broader system-level understanding of renewable energy technologies that can be used by engineers, researchers, and government agencies when studying the life-cycle cost of power-generating systems.
Performance and Emissions of Drop-in Aviation Biofuels in a Lab Scale Gas Turbine Combustor
Authors: Feser Joseph S. , Gupta Ashwani K.
Published: October 2020

There is a growing need for drop-in biofuels for gas turbines for enhanced energy security and sustainability. Several fuels are currently being developed and tested to reduce dependency on fossil fuels while maintaining performance, particularly in the aviation industry. The transition from traditional fossil fuels to sustainable biofuels is much desired for reducing the rapidly rising CO2 levels in the environment. This requires biofuels to be drop-in ready, where there are no adverse effects on performance and emissions upon replacement. In this study the performance and emissions of four different aviation drop-in biofuels was evaluated. They include: UOP HEFA-SPK, Gevo ATJ, Amyris Farnesane, and SB-JP-8. These aviation biofuels are currently being produced and tested to be ready for full or partial drop-in fuels as the replacement of traditional jet fuels. The characteristic performance of each fuel from the prevaporized liquid fuels was performed in a high intensity (20 MW/m3-atm) reverse flow combustor. The NO emissions showed near unity ppm levels for each of the fuels examined with a minimum at an equivalence ratio of ∼0.6, while CO levels were in the range of 1000–1300 ppm depending on the fuel at an equivalence ratio between 0.75–0.8. For an equivalence ratio range between 0.4 and 0.6, NO and CO emissions remained very low (between 1–2ppm NO and 2400–2900ppm CO) depending on the fuel. The examined biofuels did not show any instability over a wide range of equivalence ratios from lean to near stoichiometric condition. These results provide promising results on the behavior of these drop-in aviation biofuels for use in high intensity gas turbine combustors providing stability and cleaner performance without any modification to the combustor design.
Articulatory tongue shape analysis of Mandarin alveolar–retroflex contrast
Authors: Luo Shan
Published: October 2020

As existing descriptions are likely too narrow to reflect a broader range of articulatory variability in Mandarin production, this study is undertaken to explore qualitative and quantitative tongue shape analysis in Mandarin sibilants. Tongue movement data are collected from 18 adult Mandarin speakers producing six sibilants in three vowel contexts. Acoustic information is also analyzed to establish the articulatory–acoustic correspondence. In addition to the common retroflex and bunched shapes, the results discovered a humped shape (e.g., a single, posterior lingual constriction) in most of Mandarin retroflex tokens. This shape is one variant of North American English /r/, but yet identified in Mandarin production. The humped shape adds to the literature and expands existing descriptions of Mandarin retroflex tongue configurations. Despite the shape differences, the general many-to-one articulatory-acoustic mappings also holds true for Mandarin retroflexes. However, while curvature analyses based on Cartesian coordinates significantly differentiated contrastive shapes in retroflex production, these analyses were not equally reliable in separating the alveolar–retroflex distinction, likely due to individual differences. The tongue contour changes in the place contrast were instead quantified by calculations with polar coordinates. The preliminary findings on Mandarin retroflexes are discussed in terms of vocal tract morphology, with possible lip protrusion.
The influence of irregular terrain on infrasonic propagation in the troposphere
Authors: Blom Philip
Published: October 2020

The relations describing the reflection of three-dimensional acoustic ray paths impinging on a non-flat surface are derived and used to approximate the propagation of infrasonic signals over irregular terrain in the geometric limit. The influence of non-flat ground is strongest for those paths that reflect off the surface multiple times, such as those in the tropospheric waveguide; however, notable differences in source and receiver elevations for stratospheric and thermospheric paths can produce notable differences in travel times and arrival amplitudes. The interaction of ray paths with topographical features is investigated using a simple hill to demonstrate the impact of topography on propagation within an azimuthal plane, as well as cases in which the ground surface interaction deflects the path out of the azimuthal plane. Finally, broadband waveform predictions are compared with observations for an event in the western U.S., and a statistical analysis of scattering losses due to interaction with topography in the limit of geometric acoustics is used to improve the agreement between predicted and observed infrasonic signals.
Site-Specific Mutations of GalR Affect Galactose Metabolism in Streptococcus pneumoniae
Authors: McLean Kimberley T. , Tikhomirova Alexandra , Brazel Erin B. , Legendre Salomé , Haasbroek Gian , Minhas Vikrant , Paton James C. , Trappetti Claudia
Published: October 2020

Pneumococcal survival in the host and capacity to transition from a commensal to a pathogenic lifestyle are closely linked to the organism’s ability to utilize specific nutrients in distinct niches. Galactose is a major carbon source for pneumococci in the upper respiratory tract. We have shown that both the Leloir and tagatose 6-phosphate pathways are necessary for pneumococcal growth in galactose and demonstrated GalR-mediated interplay between the two pathways. Moreover, the three putative phosphorylation sites in the transcriptional regulator GalR play a critical role in galactose metabolism and are important for pneumococcal colonization of the nasopharynx, middle ear, and lungs.
High-Resolution Mapping of Human Norovirus Antigens via Genomic Phage Display Library Selections and Deep Sequencing
Authors: Huang Wanzhi , Soeung Victoria , Boragine David M. , Hu Liya , Prasad B. V. Venkataram , Estes Mary K. , Atmar Robert L. , Palzkill Timothy
Published: October 2020

NoV infections are a leading cause of gastroenteritis in the United States. Human NoVs exhibit extensive genetic and antigenic diversity, which makes it challenging to design a vaccine that provides broad protection against infection. Antibodies developed during the immune response play an important role in the control of NoV infections. Neutralizing antibodies that act by sterically blocking the site on the virus used to bind human cells have been identified. Identification of other antibody binding sites associated with virus neutralization is therefore of interest. Here, we use a high-resolution method to map multiple antibody binding sites simultaneously from complex serum samples. The results show that a relatively small number of sites on the virus bind a large number of independently generated antibodies, suggesting that immunodominance plays a role in the humoral immune response to NoV infections.
Haemorrhage rates of ruptured and unruptured brain arteriovenous malformation after radiosurgery: a nationwide population-based cohort study
Authors: Chye Cien-Leong , Wang Kuo-Wei , Chen Han-Jung , Yeh Shyh-An , Tang James Taoqian , Liang Cheng-Loong
Published: October 2020

Objectives

The present nationwide population-based cohort study aims to assess the effectiveness of gamma knife radiosurgery (GKS) on ruptured and unruptured brain arteriovenous malformations (AVMs) by evaluating the haemorrhage rates.

Design

A nationwide, retrospective cohort study.

Setting

Taiwan National Health Insurance Research Database (NHIRD).

Participants

An observational study of 1515 patients who were diagnosed with brain AVMs between 1997 and 2013 from the Taiwan NHIRD.

Primary outcome and secondary outcome measures

We performed a survival analysis using the Kaplan-Meier method. Multivariate Cox proportional hazards regression models were used to explore the relationship between treatment modalities (GKS vs non-GKS) and haemorrhage, adjusted for age and sex.

Results

The GKS and non-GKS groups included 317 and 1198 patients, respectively. Patients in the GKS group (mean±SD, 33.08±15.48 years of age) tended to be younger than those in the non-GKS group (37.40±17.62) (p<0.001). The 15-year follow-up revealed that the rate of bleeding risk was lower in the GKS group than in the non-GKRS group (adjusted HR (aHR) 0.61; 95% CI 0.40 to 0.92). The bleeding risk of ruptured AVMs was significantly lower in GKS group than in the non-GKS group (aHR 0.34; 95% CI 0.19 to 0.62). On the other hand, the bleeding risk of unruptured AVMs was higher in the GKS group than in the non-GKS group (aHR 1.95; 95% CI 1.04 to 3.65). In the unruptured AVM group, the incidence of bleeding was significantly higher among patients in the GKS group that were of >40 years of age (aHR 3.21; 95% CI 1.12 to 9.14).

Conclusions

GKS is safe and it reduces the risk of haemorrhage in patients with ruptured AVMs. The administration of GKS to patients with unruptured AVMs who are above the age of 40 years old male might increase the risk of haemorrhage.
Do lifestyle measures to counter COVID-19 affect frailty rates in elderly community dwelling? Protocol for cross-sectional and cohort study
Authors: Shinohara Tomoyuki , Saida Kosuke , Tanaka Shigeya , Murayama Akihiko
Published: October 2020

Introduction

Local activities that functioned to prevent frailty in the elderly have been suspended or reduced as a countermeasure against COVID-19. As a result, frailty rates are expected to increase, and frailty is expected to worsen as a secondary problem associated with COVID-19 countermeasures. Therefore, this study aims to determine the extent of frailty in the elderly associated with lifestyle changes implemented as COVID-19 countermeasures, to ascertain actual lifestyle changes and clarify the existence of Corona-Frailty. We will also conduct Corona-Frailty screening to verify the effect of support provided as feedback to supporters of the elderly.

Methods and analysis

The survey target area is Takasaki City, Gunma Prefecture, Japan. Phase I aims to verify the short-term effects of COVID-19. A questionnaire will be distributed to 465 community-dwelling elderly people, and responses will be obtained by post. Frailty will be evaluated using the Frailty Screening Index. Respondents who are frail and have had many changes in their lifestyle will be screened as high-risk people, and feedback will be provided to local supporters. The aim of Phase II will be to verify the long-term effects of COVID-19 and the effect of screening. A similar survey will be distributed twice after the first survey, once after 6 months and again after 1 year and the frailty rate will be tested. Furthermore, out of the subjects identified with frailty in Phase I, the progress of those who were screened and those who were not screened will be compared between groups.

Ethics and dissemination

This study has been approved by the Research Ethics Committee of the Takasaki University of Health and Welfare (approval number: 2009). The results of this study will be reported to the policymaker, presented at academic conferences and published in peer-reviewed journals.

Trial registration number

UMIN000040335.
Findings and lessons learnt from early termination of a pragmatic comparative effectiveness trial of video consultations in home-based palliative care
Authors: Nguyen Huong Q. , McMullen Carmit , Haupt Eric C , Wang Susan E , Werch Henry , Edwards Paula E , Andres Gina M , Reinke Lynn , Mittman Brian S , Shen Ernest , Mularski Richard A
Published: October 2020

Background

Health systems need evidence about how best to deliver home-based palliative care (HBPC) to meet the growing needs of seriously ill patients. We hypothesised that a tech-supported model that aimed to promote timely inter-professional team coordination using video consultation with a remote physician while a nurse is in the patient’s home would be non-inferior compared with a standard model that includes routine home visits by nurses and physicians.

Methods

We conducted a pragmatic, cluster randomised non-inferiority trial across 14 sites (HomePal Study). Registered nurses (n=111) were randomised to the two models so that approximately half of the patients with any serious illness admitted to HBPC and their caregivers were enrolled in each study arm. Process measures (video and home visits and satisfaction) were tracked. The primary outcomes for patients and caregivers were symptom burden and caregiving preparedness at 1–2 months.

Results

The study was stopped early after 12 months of enrolment (patients=3533; caregivers=463) due to a combination of low video visit uptake (31%), limited substitution of video for home visits, and the health system’s decision to expand telehealth use in response to changes in telehealth payment policies, the latter of which was incompatible with the randomised design. Implementation barriers included persistent workforce shortages and inadequate systems that contributed to scheduling and coordination challenges and unreliable technology and connectivity.

Conclusions

We encountered multiple challenges to feasibility, relevance and value of conducting large, multiyear pragmatic randomised trials with seriously ill patients in the real-world settings where care delivery, regulatory and payment policies are constantly shifting.
Do private German health insurers invest their capital reserves of €353 billion according to environmental, social and governance criteria?
Authors: Schneider Frederick , Gogolewska Julia , Ahrend Klaus-Michael , Hohendorf Gerrit , Schneider Gerhard , Busse Reinhard , Schulz Christian M
Published: October 2020

Background

To prevent the planet from catastrophic global warming a reduction of greenhouse gas emissions to net zero is required. Thus, divestment from fossil fuels must be a strategic interest for health insurers. The aim of this study was to analyse the implementation of environmental, social and governance (ESG) criteria in German private health insurers’ investments.

Methods

In 2019 a survey about ESG strategies was sent to German private health insurance companies. The survey evaluated investment strategies and thresholds for the exclusion of sectors and business practices, as well as company strategies for sustainable business development.

Findings

Given their business reports, German private health insurers manage assets of more than €350 billion. 11 of 40 insurance companies provided quantitative data, 10 refused to answer. According to quantitative data, €66 billion of assets is managed according to any ESG criteria; this equals an average of 76% of each company’s bonds. None of these insurers excluded the production and sale of fossil fuels. All excluded coal mining but only at high thresholds. For €226 billion, no data were provided.

Interpretation

The findings are in contrast to the expected intrinsic economic interest of the insurers to stop global warming and improve public health. The majority of assets are managed in a highly problematic manner, especially the absence of capital allocated in fields contrary to medical ethics (eg, firearms, armour) cannot be presumed. Lack of transparency is a major problem that limits clients in choosing the insurer who has the most advanced ESG criteria.
New Crassigyrinus-like fibula from the Tournaisian (earliest Carboniferous) of Nova Scotia
Authors: Lennie Kendra I. , Mansky Chris F. , Anderson Jason S.
Published: October 2020

The transition between the Devonian and Carboniferous is important for tetrapod vertebrates. By the end of the Devonian the first limbs are present in aquatic animals, and by the mid Carboniferous fully terrestrial tetrapods have diversified. Knowledge of the fin-to-limb transition is sparse because few fossils from the earliest Carboniferous (Tournaisian) are known. Blue Beach Nova Scotia, in addition to a small number of sites in Scotland and Australia, is an exception to this global trend. Previous reports from Blue Beach identified fossils from a variety of Devonian-like and Carboniferous-like tetrapod body forms, making it a valuable site for studying the fin-to-limb transition. Here we report on a new left fibula from Blue Beach, which we attribute to the later occurring Visean-aged (early Carboniferous) Crassigyrinidae. Recent investigations of deposits in Scotland, similar in age to the Tournaisian exposed at Blue Beach, have found Crassigyrinus-like elements as well, reinforcing this 20-million-year lineage extension.
$$\varLambda $$ and $$\varSigma $$ Excitations and the Quark Model
Authors: Klempt E. , Burkert V. , Thoma U. , Tiator L. , Workman R. ,   The Baryon@PDG Group
Published: October 2020

The spectrum of$$\varLambda $$Λand$$\varSigma $$Σexcitations is reviewed taking into account (nearly) all hyperon resonances which were seen in early analyses or in one of the recent partial-wave analyses. The spectrum is compared with the old Isgur–Karl model and the Bonn model. These models allows us to discuss the SU(3) structure of the observed resonances. The SU(3) decomposition is compared with SU(6) relations between the different decay modes. Seven$$\varLambda $$Λstates are proposed to be classified as SU(3) singlet states. The hyperon spectrum is compared with the spectrum ofNand$$\varDelta $$Δresonances.
Masses and electric charges: gauge anomalies and anomalous thresholds
Authors: Gómez César , Letschka Raoul
Published: October 2020

We work out in the forward limit and up to order $$e^6$$

e
6

in perturbation theory the collinear divergences. In this kinematical regime we discover new collinear divergences that we argue can be only cancelled using quantum interference with processes contributing to the gauge anomaly. This rules out the possibility of a quantum consistent and anomaly free theory with massless charges and long range interactions. We use the anomalous threshold singularities to derive a gravitational lower bound on the mass of the lightest charged fermion.
Decay properties of $$P_c$$ states through the Fierz rearrangement
Authors: Chen Hua-Xing
Published: October 2020

We systematically study hidden-charm pentaquark currents with the quark configurations$$[\bar{c} u][u d c]$$[c¯u][udc],$$[\bar{c} d][u u c]$$[c¯d][uuc], and$$[\bar{c} c][u u d]$$[c¯c][uud]. Some of their relations are derived using the Fierz rearrangement of the Dirac and color indices, and the obtained results are used to study strong decay properties of$$P_c$$Pcstates as$$\bar{D}^{(*)} \varSigma _c$$D¯(∗)Σchadronic molecules. We calculate their relative branching ratios for the$$J/\psi p$$J/ψp,$$\eta _c p$$ηcp,$$\chi _{c0} p$$χc0p,$$\chi _{c1} p$$χc1p,$$\bar{D}^{(*)0} \varLambda _c^+$$D¯(∗)0Λc+,$$\bar{D}^{0} \varSigma _c^{+}$$D¯0Σc+, and$$\bar{D}^{-} \varSigma _c^{++}$$D¯-Σc++decay channels. We propose to search for the$$P_c(4312)$$Pc(4312)in the$$\eta _c p$$ηcpchannel and the$$P_c(4440)/P_c(4457)$$Pc(4440)/Pc(4457)in the$$\bar{D}^{0} \varLambda _c^+$$D¯0Λc+channel.
Super Edge-Connected Linear Hypergraphs
Authors: Lin Shangwei , Pei Jianfeng , Li Chunfang
Published: October 2020

A connected graph [Formula: see text] is super edge-connected, if every minimum edge-cut of [Formula: see text] is the set of edges incident with a vertex. In this paper, the concept of super edge-connectivity of graphs is generalized to hypergraphs and a necessary and sufficient condition for an [Formula: see text]-uniform and linear hypergraph with diameter at most 2 to be super edge-connected is given.
Association between Vitamin D Levels and Fertility Outcomes in Patients Undergoing IVF/ICSI
Authors: Ha Anh N. , Pham Toan D. , Vuong Lan N.
Published: October 2020

Background: Several studies have demonstrated that vitamin D (vitD) might play an important role in the reproductive system due to expression of vitD receptor and vitD-metabolizing enzymes in many reproductive tissues. VitD deficiency has been associated with increased risk of obstetric complications. However, the effect of vitD levels on in vitro fertilization (IVF)/ICSI outcomes is not fully understood. Evidence shows that women with adequate vitD levels might have higher pregnancy rates. This study evaluated the association between serum vitD levels and IVF/ICSI outcomes.

Methods: This multicenter, retrospective cohort study was conducted at IVFMD, My Duc Hospital and IVFMDPN, My Duc Phu Nhuan Hospital, Ho Chi Minh City, Vietnam between November 2017 and July 2019. Vietnamese patients aged 18–40 years with serum vitD (25(OH)D) samples collected before starting controlled ovarian stimulation and undergoing embryo transfer were eligible. Patients were divided into four groups based on 25(OH)D levels: <10 ng/mL, 10 to <20 ng/mL, 20 to <30 ng/mL, and [Formula: see text]30 ng/mL. The primary outcome was ongoing pregnancy rate.

Results: Of 3779 patients recruited, 25(OH)D levels were <10 ng/mL in 564 (14.9%), 10 to <20 ng/mL in 436 (11.5%), 20 to <30 in 1,142 (30.2%), and [Formula: see text]30 ng/mL in 1,637 (43.3%). Ongoing pregnancy rates were similar across the four subgroups (36%, 40%, 36%, and 36%, respectively; p = 0.409). The number of oocytes retrieved, embryos, clinical pregnancy, implantation, and miscarriage rates did not differ significantly between subgroups.

Conclusions: In this analysis, serum vitD levels did not appear to be correlated with pregnancy outcomes in patients undergoing IVF/ICSI.
Review—Thermal Safety Management in Li-Ion Batteries: Current Issues and Perspectives
Authors: Srinivasan Rengaswamy , Demirev Plamen A. , Carkhuff Bliss G. , Santhanagopalan Shriram , Jeevarajan Judith A. , Barrera Thomas P.
Published: October 2020

Approaches for thermal management of lithium-ion (Li-ion) batteries do not always keep pace with advances in energy storage and power delivering capabilities. Root-cause analysis and empirical evidence indicate that thermal runaway (TR) in cells and cell-to-cell thermal propagation are due to adverse changes in physical and chemical characteristics internal to the cell. However, industry widely uses battery management systems (BMS) originally designed for aqueous-based batteries to manage Li-ion batteries. Even the “best” BMS that monitor both voltage and outside-surface temperature of each cell are not capable of preventing TR or TR propagation, because voltage and surface-mounted temperature sensors do not track fast-emerging adverse events inside a cell. Most BMS typically include a few thermistors mounted on select cells to monitor their surface temperature. Technology to track intra-cell changes that are TR precursors is becoming available. Simultaneously, the complex pathways resulting in cell-to-cell TR propagation are being successfully modelled and mapped. Innovative solutions to prevent TR and thermal propagation are being advanced. These include modern BMS for rapid monitoring the internal health of each individual cell and physical as well as chemical methods to reduce the deleterious effects of rapid cell-to-cell heat and material transport in case of TR.
Effect of Reduced Graphene Oxide on the Ta2O5-IrO2 Electrocatalyst for Water Splitting
Authors: Salverda Allison , Dondapati Jesse S. , Thiruppathi Antony R. , Chen Aicheng
Published: October 2020

There is a great interest in the development of advanced electrocatalysts for efficient water splitting. A tantalum iridium oxide (Ta2O5-IrO2) coating is considered to be one of the best electrocatalysts for the oxygen evolution reaction (OER) in acidic media. In the present study, novel Ta2O5-IrO2-rGO coatings with varying loads of reduced graphene oxide (rGO) were designed to investigate the effects of rGO on the catalytic activity and stability of the Ta2O5-IrO2 coating for the OER. Five different electrodes comprised of Ta2O5-IrO2-rGO on a titanium substrate were fabricated with incremental weight percentages of rGO (0.0 wt.%, 1.0 wt.%, 2.0 wt.%, 5.0 wt.% and 7.5 wt.%) using a facile thermal decomposition method. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and energy dispersive X-ray spectroscopy (EDS) were employed to characterize the morphology and composition of the prepared Ta2O5-IrO2-rGO coatings. Longevity tests revealed that the incorporation of rGO into the oxide layer strongly affected the stability of the Ta2O5-IrO2-rGO electrodes. The electrochemical activities of the prepared Ta2O5-IrO2-rGO electrodes were characterized by cyclic voltammetry (CV), linear sweep voltammetry (LSV), and electrochemical impedance spectroscopy (EIS). The Ta2O5-IrO2-rGO coating containing 1.0 wt.% rGO exhibited the greatest stability, along with enhanced OER activity.
Antiplane Fracture Problem of Three Nanocracks Emanating from an Electrically Permeable Hexagonal Nanohole in One-Dimensional Hexagonal Piezoelectric Quasicrystals
Authors: Yang Dongsheng , Liu Guanting
Published: October 2020

Based on the Gurtin-Murdoch surface/interface model and complex potential theory, by constructing a new conformal mapping, the electrically permeable boundary condition with surface effect is established, and the antiplane fracture problem of three nanocracks emanating from a hexagonal nanohole in one-dimensional hexagonal piezoelectric quasicrystals with surface effect is studied. The exact solutions of the stress intensity factor of the phonon field and the phason field, the electric displacement intensity factor, and the energy release rate are obtained under the two electrically permeable and the electrically impermeable boundary conditions. The numerical examples show the influence of surface effect on the stress intensity factors of the phonon field and the phason field, the electric displacement intensity factor, and the energy release rate under the two boundary conditions. It can be seen that the surface effect leads to the coupling of the phonon field, phason field, and electric field, and with the decrease of cavity size, the influence of surface effect is more obvious.
Preoperative Estimation of Endodontic Working Length with Cone‐Beam Computed Tomography and Standardized Paralleling Technique in comparison to Its Real Length
Authors: Faraj Bestoon Mohammed
Published: October 2020

An accurate estimation of the working canal length is essential for successful root canal treatment. This study is aimed at investigating the diagnostic accuracy of root canal length estimation on cone‐beam computed tomography (CBCT) scans and digital paralleling radiographs (PAs), using the real canal length as a gold standard, and at evaluating the influence of canal curvature on this estimation. Sixty extracted human premolar teeth were selected for this study. Root canal length measurement was performed on CBCT scans (NewTom, Giano, Verona, Italy) and digital paralleling radiography (EzRay Air W; Vatech, Korea). The real working length was established by subtracting 0.5 mm from the actual canal length. No significant difference was found between CBCT and digital paralleling radiography. There was a tendency for underestimation of the root canal length measured on the CBCT images in 52 (86.7%) of the examined teeth and overestimation in 5 teeth (8.3%). All the digital radiographs slightly overestimated the real canal length. The analysis revealed a strong correlation between the estimation from moderate to severe curvature for digital radiography and CBCT images. Preoperative working length estimation can be made closest to its real clinical canal length on the standardized paralleling technique, using a long (16‐inch) target‐receptor distance.
A Posteriori Error Analysis for a New Fully Mixed Isotropic Discretization of the Stationary Stokes-Darcy Coupled Problem
Authors: Wilfrid Houédanou Koffi , Jamal Adetola , Mohamed Allaoui
Published: October 2020

In this paper, we develop an a posteriori error analysis for the stationary Stokes-Darcy coupled problem approximated by conforming the finite element method on isotropic meshes inℝd,d∈2,3. The approach utilizes a new robust stabilized fully mixed discretization. The a posteriori error estimate is based on a suitable evaluation on the residual of the finite element solution plus the stabilization terms. It is proven that the a posteriori error estimate provided in this paper is both reliable and efficient.
Research on the Stress Distribution Law of Fully Anchored Bolt and Analysis of Influencing Factors under the Condition of Surrounding Rock Deformation
Authors: Zhao Chengxing , Li Yingming , Liu Gang , Chen Dengguo , Meng Xiangrui
Published: October 2020

As the mining depth increases, the deformation of the roadway becomes more difficult to control. As a main supporting structure for maintaining the stability of roadway, the fully anchored bolt is widely used to reinforce deep mine. At the same time, the analysis of the stress distribution law of fully anchored bolt is the basic work to optimize anchor design. Therefore, this paper establishes a fully anchored bolt‐surrounding rock interaction model based on the law of surrounding rock deformation and derives the analytical expressions for the axial force and shear stress of the fully anchored bolt during normal support and critical failure. At the same time, the effects of surrounding rock properties, support resistance, and bolt length on the stress distribution of fully anchored bolt are analyzed. The results show that the stress distribution of fully anchored bolt is consistent with the “neutral point” theory and the most important is the fact that the conditions of surrounding rock, the supporting resistance, and the length of bolt affect the actual stress distribution of the fully anchored bolt. It provides a certain theoretical basis for the design and development of anchoring and supporting technology.