bluuebunny/crossref_metadata_2025 huggingface dataset:
Predicted quality benefits of achievable performance benchmarks of chronic heart failure care in China: results from a nationwide observational study
Authors: Yin Chang , Li Xi , Wang Chao , Li Jingkun , Bao Xiaoqiang , Zhang Qiuju , Wang Yupeng , Ma Xudong , Liu Meina
Published: September 2020

Objectives

This study aimed to set a data-driven achievable performance benchmark, explore the process–outcome association and speculate about the net gain in quality improvement with benchmarking.

Design

Observational study.

Setting

Patient survey conducted at 466 secondary and tertiary hospitals across 31 provinces, autonomous regions and municipalities in China.

Participants

183 334 patients diagnosed with chronic heart failure (CHF) who were treated at 466 Chinese hospitals from January 2011 through May 2017.

Primary independent variables

Hospital process composite performance (HPCP).

Secondary independent variables

Patient-level and hospital-level characteristics.

Primary outcome measure

Patients getting better or recovered after treatment, in-hospital mortality, length of hospital stay (LOS) and medical cost.

Methods

HPCP was calculated using denominator-based weights. Mixed random-intercept models were used to evaluate the contributions of HPCP on patient outcomes and to speculate quality improvement after adjusting HPCP to benchmark level.

Results

When all hospitals were to operate at the benchmark level, the proportion of patients getting better or recovered after treatment would increase in most hospitals, particularly those with low baseline rates. However, there was no evidence for lowering in-hospital mortality, significant savings in cost or shortening LOS.

Conclusions

Increasing the adherence rate of CHF care and closing the gap in HPCP between hospitals have important implications for improving patient condition.
Patients’ and caregivers’ perspectives on access to kidney replacement therapy in rural communities: systematic review of qualitative studies
Authors: Scholes-Robertson Nicole Jane , Howell Martin , Gutman Talia , Baumgart Amanda , SInka Victoria , Tunnicliffe David J , May Stephen , Chalmers Rachel , Craig Jonathan , Tong Allison
Published: September 2020

Objective

Patients with chronic kidney disease (CKD) requiring kidney replacement therapy (KRT) in rural communities encounter many barriers in accessing equitable care and have worse outcomes compared with patients in urban areas. This study aims to describe the perspectives of patients and caregivers on access to KRT in rural communities to inform strategies to maximise access to quality care, and thereby reduce disadvantage, inequity and improve health outcomes.

Setting

18 studies (n=593 participants) conducted across eight countries (Australia, Canada, the UK, New Zealand, Ghana, the USA, Tanzania and India).

Results

We identified five themes: uncertainty in navigating healthcare services (with subthemes of struggling to absorb information, without familiarity and exposure to options, grieving former roles and yearning for cultural safety); fearing separation from family and home (anguish of homesickness, unable to fulfil family roles and preserving sense of belonging in community); intense burden of travel and cost (poverty of time, exposure to risks and hazards, and taking a financial toll); making life-changing sacrifices; guilt and worry in receiving care (shame in taking resources from others, harbouring concerns for living donor, and coping and managing in isolation).

Conclusion

Patients with CKD in rural areas face profound and inequitable challenges of displacement, financial burden and separation from family in accessing KRT, which can have severe consequences on their well-being and outcomes. Strategies are needed to improve access and reduce the burden of obtaining appropriate KRT in rural communities.
A journey to a new stable state—further development of the postoperative recovery concept from day surgical perspective: a qualitative study
Authors: Nilsson Ulrica , Jaensson Maria , Hugelius Karin , Arakelian Erebouni , Dahlberg Karuna
Published: September 2020

Objective

This study aims to further develop the concept analysis by Allvin et al in 2007 and Lundmark et al in 2016 from the perspective of day-surgery patients. Also, to describe how patients experience postoperative recovery in relation to the identified dimensions and subdimensions and to interpret the findings in order to get a deeper understanding of the concept postoperative recovery.

Design

Descriptive qualitative design with a theoretical thematic analysis.

Setting

Six day-surgery departments in Sweden.

Participants

Thirty-eight adult participants who had undergone day surgery in Sweden. Participants were purposively selected.

Results

Four dimensions—physical, psychological, social and habitual—were confirmed. A total of eight subdimensions were also confirmed, two from Allvin et al’s study and six from Lundmark et al’s study. Recovery included physical symptoms and challenges coping with and regaining control over symptoms and bodily functions. Both positive and negative emotions were present, and strategies on how to handle emotions and achieve well-being were established. Patients became dependent on others. They coped with and adapted to the recovery process and gradually stabilised, reaching a new stable state.

Conclusion

Postoperative recovery was described as a process with a clear starting point, and as a dynamic and individual process leading to an experience of a new stable state. The recovery process included physical symptoms, emotions and social and habitual consequences that challenges them. To follow-up and measure all four dimensions of postoperative recovery in order to support and understand the process of postoperative recovery is, therefore, recommended.
Patients’ preferences for health insurance coverage of new technologies for treating chronic diseases in China: a discrete choice experiment
Authors: Geng Jinsong , Chen Xiaowei , Bao Haini , Qian Danmin , Shao Yuting , Yu Hao
Published: September 2020

Objectives

Our study aimed to inform insurance decision-making in China by investigating patients’ preferences for insurance coverage of new technologies for treating chronic diseases.

Design

We identified six attributes of new medical technologies for treating chronic diseases and used Bayesian-efficient design to generate choice sets for a discrete choice experiment (DCE). After conducting the DCE, we analysed the data by mixed logit regression to examine patient-reported preferences for each attribute.

Setting

The DCE was conducted with patients in six tertiary hospitals from four cities in Jiangsu province.

Participants

Patients aged 18 years or older with a history of diabetes or hypertension and taking medications regularly for more than 1 year were recruited (n=408).

Results

The technology attributes regarding expected gains in health outcomes from the treatment, high likelihood of effective treatment and low incidence of serious adverse events were significant, positive predictors of choice by the study patients (p<0.01). The out-of-pocket cost was a significant, negative attribute for the entire study sample (β = −0.258, p<0.01) and for the patients with Urban-Rural Residents Basic Medical Insurance (URRBMI) (β = −0.511, p<0.01), but not for all the patients with Urban Employees Basic Medical Insurance (UEBMI) (β = −0.071, p>0.05). The severity of target disease was valued by patients with lower EQ-5D-5L index value as well as URRBMI enrollees.

Conclusions

Patients highly valued the health benefits and risks of new technologies, which were closely linked to their feelings of disease and perceptions of health-related quality of life. However, there existed heterogeneity in preferences between URRBMI and UEBMI patients. Further efforts should be made to reduce the gap between insurance schemes and make safe and cost-effective new technologies as a priority for health insurance reimbursement.
Value of dynamic clinical and biomarker data for mortality risk prediction in COVID-19: a multicentre retrospective cohort study
Authors: Berzuini Carlo , Hannan Cathal , King Andrew , Vail Andy , O'Leary Claire , Brough David , Galea James , Ogungbenro Kayode , Wright Megan , Pathmanaban Omar , Hulme Sharon , Allan Stuart , Bernardinelli Luisa , Patel Hiren C
Published: September 2020

Objectives

Being able to predict which patients with COVID-19 are going to deteriorate is important to help identify patients for clinical and research practice. Clinical prediction models play a critical role in this process, but current models are of limited value because they are typically restricted to baseline predictors and do not always use contemporary statistical methods. We sought to explore the benefits of incorporating dynamic changes in routinely measured biomarkers, non-linear effects and applying ‘state-of-the-art’ statistical methods in the development of a prognostic model to predict death in hospitalised patients with COVID-19.

Design

The data were analysed from admissions with COVID-19 to three hospital sites. Exploratory data analysis included a graphical approach to partial correlations. Dynamic biomarkers were considered up to 5 days following admission rather than depending solely on baseline or single time-point data. Marked departures from linear effects of covariates were identified by employing smoothing splines within a generalised additive modelling framework.

Setting

3 secondary and tertiary level centres in Greater Manchester, the UK.

Participants

392 hospitalised patients with a diagnosis of COVID-19.

Results

392 patients with a COVID-19 diagnosis were identified. Area under the receiver operating characteristic curve increased from 0.73 using admission data alone to 0.75 when also considering results of baseline blood samples and to 0.83 when considering dynamic values of routinely collected markers. There was clear non-linearity in the association of age with patient outcome.

Conclusions

This study shows that clinical prediction models to predict death in hospitalised patients with COVID-19 can be improved by taking into account both non-linear effects in covariates such as age and dynamic changes in values of biomarkers.
Childhood correlates of adult positive mental well-being in three British longitudinal studies
Authors: Wood Natasha , Hardy Rebecca , Bann David , Gale Catharine , Stafford Mai
Published: September 2020

Background

Previous evidence has shown how experiences within childhood, such as parenting and socioeconomic conditions, are associated later on in life with adult mental well-being. However, these studies tend to focus on childhood experiences in isolation, and fewer studies have investigated how multiple aspects of the childhood environment, including both socioeconomic and psychosocial aspects, are associated with adult positive mental well-being. Using data from three British birth cohort studies, we investigated how prospective measures of the childhood environment up to the age of 16 years were associated with midlife adult mental well-being and whether similar associations were replicated across different generations.

Methods

Childhood environment comprised socioeconomic circumstances, psychosocial factors (child-rearing and parenting, family instability) and parental health. The Warwick-Edinburgh Mental Wellbeing Scale, a validated instrument measuring both hedonic and eudaemonic aspects of well-being, was administered in mid-life. We modelled associations between childhood environment domains and well-being.

Results

Despite changes in social context in all three studies, poorer quality parent–child relationships and poor parental mental health were strongly and independently associated with poorer adult mental well-being. Socioeconomic circumstances were also associated with adult mental well-being, but the association was weaker than for the measures of parenting or parental mental health.

Conclusion

These findings confirm that parenting and parental mental health, as well as socioeconomic circumstances, are important for adult mental well-being. Interventions in early childhood aimed at reducing socioeconomic adversity and offering support to parents might be warranted, to enhance adult mental well-being later on in the life course.
Occupational factors in the COVID-19 pandemic in Italy: compensation claims applications support establishing an occupational surveillance system
Authors: Marinaccio Alessandro , Boccuni Fabio , Rondinone Bruna Maria , Brusco Adelina , D'Amario Silvia , Iavicoli Sergio
Published: September 2020

Introduction

The SARS-CoV-2 pandemic is an impacting challenge for occupational health. Epidemiological surveillance of COVID-19 includes systematic tracking and reporting of the total cases and deaths, but suitable experiences of surveillance systems for identifying the occupational risk factors involved in the COVID-19 pandemic are still missing, despite the interest for occupational safety and health.

Methods

A methodological approach has been implemented in Italy to estimate the occupational risk of infection, classifying each economic sector as at low, medium-low, medium-high and high risk, based on three parameters: exposure probability, proximity index and aggregation factor. Furthermore, during the epidemic emergency, the Italian Workers’ Compensation Authority introduced the notation of COVID-19 work-related infection as an occupational injury and collected compensation claims of workers from the entire national territory.

Results

According to compensation claims applications, COVID-19 infection in Italy has been acquired at the workplace in a substantial portion of the total cases (19.4%). The distribution of the economic sectors involved is coherent with the activities classified at risk in the lockdown period. The economic sectors mostly involved were human health and social work activities, but occupational compensation claims also include cases in meat and poultry processing plants workers, store clerks, postal workers, pharmacists and cleaning workers.

Conclusions

There is a need to go towards an occupational surveillance system for COVID-19 cases, including an individual anamnestic analysis of the circumstances in which the infection is acquired, for the prevention of occupational infectious risk, supporting insurance system effectiveness and managing vaccination policies.
Memory complaints in the epilepsy clinic
Authors: Baxendale Sallie , Heaney Dominic
Published: September 2020

Cognitive complaints in people with epilepsy are usually multifactorial in their nature and origin. While antiepileptic medications are an important consideration, we explore other ways in which neurologists can address cognitive problems in this population. It is never too early to ask about cognitive impairment, and the answers can have diagnostic significance. Understanding and accepting that cognitive problems may result, at least in part, from the same pathological process that generates seizures is an important part of the rehabilitation process. Patients referred for neurorehabilitation for cognitive difficulties who have realistic expectations and goals tend to benefit more from the intervention than those expecting a cure. Developing an understanding of this and managing patient expectations should start in the neurology clinic. Although we focus primarily on memory function, the principles we discuss in this paper apply to the broad spectrum of cognitive and neurobehavioral problems that accompany the many diagnoses of epilepsy.
Boosting the Tobacco Control Vaccine: recognizing the role of the retail environment in addressing tobacco use and disparities
Authors: Kong Amanda Y. , King Brian A.
Published: September 2020

Much of the progress in reducing cigarette smoking and tobacco-related morbidity and mortality among youth and adults is attributable to population-level strategies previously described in the context of the Tobacco Control Vaccine. The retail environment is used heavily by the tobacco industry to promote and advertise its products, and variations in exposure to and characteristics of the retail environment exist across demographic groups. It is therefore also an essential environment for further reducing smoking, as well as ameliorating racial, ethnic and socioeconomic tobacco-related disparities. This commentary provides an overview of the importance of incorporating strategies focused on the tobacco retailer environment (availability; pricing and promotion; advertising and display; age of sale; and retail licensure) as part of a comprehensive approach to tobacco prevention and control. To reach tobacco endgame targets, such innovative strategies are a complement to, but not a replacement for, long-standing evidence-based components of the Tobacco Control Vaccine.
Adipose‐derived autologous mesenchymal stem cell transfusion for the treatment of feline chronic gingivostomatitis in a domestic shorthair cat
Authors: Dye Charlotte
Published: September 2020

This report describes a successful outcome following the use of adipose‐derived autologous mesenchymal stem cell therapy for the treatment of refractory feline chronic gingivostomatitis in a domestic shorthair cat.
Boundary restricted genetic algorithm for multi-layer equivalent dielectric parameters retrieval of artificial gradient structure
Authors: Guo Shaojun , Shen Tongsheng , Zou Chunrong
Published: September 2020

With the equivalent dielectric parameters of an artificial gradient structure consisting of a kind of dielectric material as inputs of FDTD multi-layer equivalent simulation, there are big nonuniform differences between the S-curve of retrieval methods and the corresponding full structure. In order to decease these differences, here, a boundary restricted genetic algorithm is proposed. In our method, Smith S method is employed to find the rough values of dielectric parameters, and at the same time, the up and low limit cases are introduced to calculate the boundary parameter values for each layer of the artificial structure and form the searching areas for genetic algorithm to get high-precision inversion of S-curve. The FDTD S-curve of the retrieval parameters and full structure of cone gradient and moth eye were performed experimentally, the maximum deviation of inversion S21 curves corresponding to the cone and moth eye with full structure is limited within 0.0028 and 0.0024 in the X-band (8–12[Formula: see text]GHz) range, respectively, which shows us the promising application of our method in dielectric parameter retrieval and may be helpful for electromagnetic field analysis.
Fractional oscillator noise and its applications
Authors: Fa Kwok Sau
Published: September 2020

It is shown that a fractional oscillator (FO) noise, which is a generalization of the ordinary overdamped linear oscillator driven by the white noise may be ‘applied to diverse systems; its stationary correlation function presents

power-law-like function, exponential-like function, exponential function, and oscillatory decays. The model may be employed to describe the fluctuation of the distance between a fluorescein–tyrosine pair within a single protein complex and the internal dynamics of a lysozyme molecule in solution. It also has the possibility of describing a Brownian particle in an oscillatory viscoelastic shear flow.
Poisson’s ratio in the all-inorganic perovskite monolayers
Authors: Liu Kaijun , Zeng Weihao , Liu Danyang , Quhe Ruge
Published: September 2020

Poisson’s ratios of two-dimensional (2D) all-inorganic perovskites Cs2PbX4 (X = Cl, Br, I) have been calculated by the first-principles calculations. The contribution of each geometric parameter (bond length [Formula: see text], bond angle [Formula: see text], rotation angle [Formula: see text], and tilt angle [Formula: see text]) to Poisson’s ratio is obtained analytically. Through a comprehensive analysis of the geometric deformations of the perovskite under the uniaxial strain, we find that Poisson’s ratios of the perovskites are sensitive to the change of the bond length [Formula: see text] and the bond angle [Formula: see text]. In addition, the value of the bond angle [Formula: see text] in the strain-free structure mainly determines the high in-plane anisotropy of Poisson’s ratios in Cs2PbX4.
Universal Optimization Strategies for Object Detection Networks
Authors: Shi Ziyu , Gao Haichang , Tang Yiwen , Zheng Han , Kang Shuai , Liu Yi
Published: September 2020

With the development of deep learning technologies, object detection algorithms have made significant progress in terms of detection speed and detection performance. However, the detection speed of current detection networks still does not meet the requirements of real-world applications in some scenarios. In this paper, we propose a faster non-maximum suppression (FNMS) algorithm that reduces the processing time by a large margin while achieving the same detection precision compared with the traditional non-maximum suppression (NMS) algorithm. Moreover, an attempt is made to adopt additional lightweight network structures to improve the speed of the detection network. By combining our FNMS algorithm with other network optimization strategies, we are able to improve the detection speed of YOLO v3 on the DOTA dataset by 165%.
Black hole entropy from soft hair
Authors: Perry Malcolm J.
Published: September 2020

We start by looking at why we believe that black holes have entropy. According to Boltzmann, the entropy is a measure of the number of microstates of a system. We suggest here that the entropy arises from a holographic conformal field theory on the black hole horizon. Finally, we discuss some of the implications for the information paradox.
Mass-spin relation of black holes obtained by twin high-frequency quasi-periodic oscillations
Authors: Stefanov Ivan Zhivkov
Published: September 2020

The paper studies the uniqueness and the monotonicity of the mass-spin relation of black holes (BHs) the X-ray power density spectra of which contain twin high-frequency quasi-periodic oscillations in 3:2 ratio. Some of the results are valid for a relatively large class of models — the geodesic models, which attribute the observed pair of HF QPOs to the frequencies of epicyclic motion of inhomogeneities in the accretion disk surrounding the black hole, treated as point particles, or to simple linear combinations of them. It is found that for geodesic models the properties of the mass-spin relation are independent of the observed frequencies, i.e. they are independent of the particular object. For concreteness two of the most commonly used geodesic models are studied here – the 3:1 nonlinear epicyclic resonance model and its Keplerian version.
Release characteristics of different diameter ultrafine fibers as antibacterial materials
Authors: Wei Zhiqiang , Liu Erniao , Li Hao , Wei Zhimei , lv Zhi
Published: September 2020

Although the electrospinning technique has been devoted to promoting therapeutic purposes as a drug carrier, however, there are still many fundamental problems in this area. This work focuses on a comparison of various diameter polyethersulfone (PES) electrospun ultrafine fibers as antimicrobial materials. The fibrous morphology, antimicrobial agent distribution, thermally property, and biocompatibility evaluation of PES-based ultrafine fibers were systematically investigated. The results demonstrated that the PES-based ultrafine fibers were suitable as antimicrobial material. Furthermore, the drug release behavior and mechanism were studied through total immersion. The release mechanism was confirmed to Fickian diffusion. It was revealed that the drug max release amount (71.5%) and release rate (7.71) are the highest for the smallest diameter ultrafine fibers. Meanwhile, the antimicrobial activity of PES ultrafine fibers is also inversely correlated with the diameter of fiber. The electrospun PES fibers would control their release behavior through the diameter and have a potential application in the wound dressings, such as chronic osteomyelitis and exposure injury.
The local partition dimension of graphs
Authors: Alfarisi Ridho , Kristiana Arika Indah , Dafik
Published: September 2020

All graphs in this paper are undirected and connected graphs. An ordered k-partition set [Formula: see text] where [Formula: see text], the representation of a vertex [Formula: see text] of [Formula: see text] with respect to [Formula: see text] is [Formula: see text] where [Formula: see text] is the distance between the vertex v and the set [Formula: see text] with [Formula: see text] for [Formula: see text]. The partition set [Formula: see text] is a local resolving partition of [Formula: see text] if [Formula: see text] for [Formula: see text] adjacent to [Formula: see text] of [Formula: see text]. The minimum local resolving partition [Formula: see text] is a local partition dimension of [Formula: see text], denoted by [Formula: see text]. In our paper, we found the sharp bounds of the local partition dimension of [Formula: see text] and determine the exact value of some special graph.
Strong α-cut and associated membership-based modeling for fuzzy time series forecasting
Authors: Goyal Gunjan , Bisht Dinesh C. S.
Published: September 2020

In this paper, a method is proposed to deal with factors affecting the fuzzy time series forecasting. A new fuzzification process is used by considering all the fuzzy sets with nonzero membership values corresponding to the data points. A strong alpha-cut based method is presented to select appropriate fuzzy logical relationships that carry importance in analyzing the trend of time series. Further, a unique defuzzification approach based on weights is proposed to get crisp variation. This obtained variation is finally converted to the forecasted value. The presented method is tested on the benchmark enrolment dataset of Alabama University and seven datasets of the Taiwan Capitalization Weighted Stock Index. On comparing the results, it is observed that the presented method performs better than the existing methods. Also, the statistical measures indicate the good forecasting results of the presented method.
Influence of film stretching on crystalline phases and dielectric properties of a 70/30 mol% poly(vinylidenefluoride-tetrafluoroethylene) copolymer
Authors: Venkatesan Thulasinath Raman , Gulyakova Anna A. , Gerhard Reimund
Published: September 2020

Polyvinylidene fluoride (PVDF)-based copolymers with tetrafluoroethylene (P(VDF-TFE)), trifluoroethylene (P(VDF-TrFE)) or hexafluoropropylene (P(VDF-HFP)) are of strong interest due to the underlying fundamental mechanisms and the potential ferro-, pyro- and piezo-electrical applications. Their flexibility and their adaptability to various shapes are advantageous in comparison to inorganic ferroelectrics. Here, we study the influence of stretching temperature on the crystalline phases and the dielectric properties in P(VDF-TFE) films by means of Dielectric Relaxation Spectroscopy (DRS), Fourier-Transform InfraRed spectroscopy (FTIR), Wide-Angle X-ray Diffraction (WAXD), Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA). Especially, the effect of stretching and the influence of the temperature of stretching on the mid-temperature ([Formula: see text] transition are studied in detail. The results show that stretching has a similar effect as that on PVDF, and we observe an increase in the fraction of ferroelectric [Formula: see text]-phase with a simultaneous increment in both melting point ([Formula: see text] and crystallinity ([Formula: see text] of the copolymer. While an increase in the stretching temperature does not have a profound impact on the amount of ferroelectric phase, the stability of the ferroelectric phase seems to improve — as seen in the reduction of the Full Width at Half Maximum (FWHM) of the WAXD peaks in both parallel and perpendicular directions to the molecular chain axis. The observation is also supported by the reduction of dissipation losses with an increase in stretching temperature — as seen in DRS measurements. Finally, both stretching itself and the temperature of stretching affect the various molecular processes taking place in the temperature range of the [Formula: see text] transition.
Policy Note: Policy Responses to Ensure Access to Water and Sanitation Services During COVID-19: Snapshots from the Environment for Development (EfD) Network
Authors: Amaechina Ebele , Amoah Anthony , Amuakwa-Mensah Franklin , Amuakwa-Mensah Salome , Bbaale Edward , Bonilla Jorge A. , Brühl Johanna , Cook Joseph , Chukwuone Nnaemeka , Fuente David , Madrigal-Ballestero Róger , Marín Rolando , Nam Pham Khanh , Otieno Jackson , Ponce Roberto , Saldarriaga Carlos A. , Lavin Felipe Vasquez , Viguera Bárbara , Visser Martine
Published: September 2020

This policy note provides a snapshot of water and sanitation measures implemented by governments in response to the COVID-19 pandemic in 14 countries in the Global South: Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, Chile, Colombia, Ghana, Kenya, Nigeria, Panama, South Africa, Uganda and Vietnam. We find that many countries have taken action to stop utility disconnections due to non-payment. With the exception of Ghana and Vietnam, few countries are instituting new water subsidy programs, and are instead choosing to defer customers’ bills for future payment, presumably when the pandemic recedes and households will be able to pay their bills. It is easier for the utilities’ COVID-relief policies to target customers with piped connections who regularly receive bills. However, the situation for unconnected households appears more dire. Some countries (e.g., Ghana, Kenya, South Africa and Uganda) are attempting to provide unconnected households temporary access to water, but these households remain the most vulnerable. This health crisis has accentuated the importance of strong governance structures and resilient water service providers for dealing with external health, environmental and economic shocks.
Imaging in Three-Dimensional Waveguides with Partial Aperture Data
Authors: Papadimitropoulos Symeon , Mitsoudis Dimitrios A. , Tsogka Chrysoula
Published: September 2020

We consider the problem of imaging extended reflectors in three-dimensional acoustic waveguides using a planar array that is parallel to the waveguide’s cross-section. Our data consist of the multiple-frequency array response matrix. To form an image, we back-propagate a projection of the data on the propagating modes in the waveguide. The projection operator is adequately defined for any array-aperture size and shape that cover fully or partially the waveguide cross-section. The properties of the imaging method are analyzed theoretically and its effectiveness is assessed by numerical experiments for scatterers and arrays of varying shape and size.
We Are All Stakeholders in an AI-supplemented World
Authors: Bitas Basil C. , Harjani Manoj
Published: September 2020

Artificial Intelligence (AI) is moving into a new phase where it is demonstrating the ability to supplement or replace humans across a range of decision-making activities. The transformative power of AI will require sensible regulation and heightened ethical sensitivity to ensure that it enhances rather than undermines human capabilities and values. The successful management of AI will necessitate coordination at the national, international and supranational levels among stakeholders of all types. Moreover, the shape of an AI-supplemented world will be heavily influenced by the rivalry between China and the United States as the world’s leading economic and AI powers. This paper will weave together the above themes to outline the relevant issues and stakes and the manner in which they can be managed to yield a productive AI-supplemented future, wherein AI’s promise is maximized and its potential perils avoided or mitigated.
Religiosity and Long-Run Productivity Growth
Authors: Herzer Dierk , Strulik Holger
Published: September 2020

In this paper, we show, using a panel of developed countries, that there is a long-run negative association between church attendance and total factor productivity (TFP) with predictive causality running from declining church attendance to increasing factor productivity. According to our preferred estimate, about 18% of the increase in TFP from 1950 to 1990 can be motivated by declining religiosity. In order to explain this phenomenon, we integrate into standard R&D-based growth theory a micro-foundation of individual cognitive style, which is either intuitive-believing or reflective-analytical. Under the assumption that R&D productivity is positively influenced by a reflective-analytical cognitive style, we find that secularisation leads to an increasing labour share in R&D and gradually increasing productivity growth. We use these insights to reflect on the trends in religiosity and R&D-based growth in the very long run, from Enlightenment to the present day.
Pt-TiO2 Nanocomposite PEFC Electrocatalysts for High Potential Cycle Durability
Authors: Tonosako Tetsuya , Noda Zhiyun , Matsuda Junko , Nishihara Masamichi , Hayashi Akari , Sasaki Kazunari
Published: September 2020

Pt/C is widely used as the electrocatalyst for PEFCs, while durability is still an important issue associated with e.g. detachment and aggregation of Pt nanocatalysts. As oxide-supported electrocatalysts exhibit high durability against potential cycling, Pt-TiO2 nanocomposite electrocatalysts with a maximum contact area between Pt and TiO2 are developed for further improving their durability. X-ray diffraction (XRD) and microstructural observation by scanning transmission electron microscopy (STEM) confirmed the preparation of Pt-TiO2 nanocomposite electrocatalysts. Optimal preparation conditions are considered by varying the volume ratio of Pt to TiO2. Possible advantages and remaining issues of this nanocomposite concept are discussed.
P-Doped SnO2 Powder as a Support for PEFC Cathode
Authors: Inoue Yuta , Matsuzawa Koichi , MA Yongbing , Ohgi Yoshiro , Nagai Takaaki , Kuroda Yoshiyuki , Yamamoto Shunya , Ishihara Akimitsu
Published: September 2020

The possibility of commercial P-doped SnO2 was evaluated as a non-carbon support for PEFC cathodes. The effect of heat-treatment under various conditions on the physical properties of the P-doped SnO2 was investigated. The P-doped SnO2 was sensitive by the heat-treatment in reductive atmosphere, 4%H2/Ar. The surface area was hardly affected by the heat-treatment in air or Ar even at high temperature such as 900℃. On the other hand, the conductivity was dramatically affected by the atmosphere during the heat-treatment. The heat-treatment in Ar at higher temperature rather increased in the conductivity, whereas the heat-treatment in air caused the drastic decrease in the conductivity. This difference might be responsible for the formation and extinction of the oxygen vacancies.
(Invited) Electrochemical Energy Storage and Conversion Devices Incorporating C2-Protected Polybenzimidazoliums and Polyimidazoliums
Authors: Wei Qiliang , Chen Binyu , Cassegrain Simon , Holdcroft Steven
Published: September 2020

Alkaline anion exchange membranes (AAEMs) which are capable of conducting hydroxide ions have been investigated in various alkaline based electrochemical energy storage and conversion technologies. Electrochemical systems relying on alkaline-based active components possess unique advantages over their acidic counterparts but at the same time are associated with significant challenges. In our research, we have been investigating C2-protected polybenzimidazolium and polyimidazolium polymers as hydroxide ion conducting polymers, for membranes and ionomer in catalyst layers, because of their stability in caustic conditions, scalability in synthesis, and mechanical strength. As an example of this work, we report on the performance of C2-protected hexamethylterphenyl-polybenzimidazole-based fuel cells in which the content and surface of the carbon support in the cathode catalyst layer is functionalized. We demonstrate that the composition of the cathode catalyst layer plays a large role in determining the performance of these particular anion exchange polymers.
Investigation on Methanol Tolerance of Pt/C Cathode Catalyst with Heteroatom-Doped Carbon Layer for Direct Methanol Fuel Cell
Authors: Choi Jung-goo , Ham Kahyun , Lee Jaeyoung
Published: September 2020

One of the challenging problems of direct methanol fuel cell is methanol crossover, permeating methanol from anode to cathode and leading to voltage drop. Pt-based catalyst is known as an excellent cathode catalyst despite the harsh pH condition, but it can also react with methanol. Thus, it is crucial to design a methanol-tolerant Pt-based catalyst to increase the ORR selectivity at the cathode. In this study, we synthesized Pt/C with P-doped carbon layer. Since the P-doped carbon layer could block the diffusion of methanol, Pt/C covered by P-doped carbon layer showed similar ORR activity but extremely low activity in the methanol oxidation reaction than pristine Pt/C.
Saline Water Electrolysis Membranes Prepared via the Simultaneous Irradiation of Electron-Beam
Authors: Park In Kee , Cha Woo Ju , Lee Chang Hyun
Published: September 2020

Saline water electrolysis (SWE) is a representative electrochemical conversion process that produces hydrogen (H2), chlorine (Cl2), and sodium hydroxide (NaOH) at the same time, by applying electricity to saline water. SWE has been suffering from overpotentials much higher than its theoretical voltage of 2.2 V. The overpotentials come from high membrane resistance and/or interfacial resistance between its membrane and electrodes in zero-gap type. To solve this problem, water-soluble sulfonated polystyrene was chemically incorporated on both surface of chemically durable sulfonated poly (arylene ether sulfone) random copolymer via the simultaneous irradiation of electron-beam. The resulting membranes exhibited SWE performance superior to that of a commercially available Aciplex-F® membrane, owing to the synergistic effect of improved Na+ conductivity and reduced interfacial resistance.
Durability Analysis on PEM Water Electrolyzers against the Voltage Fluctuation of Wind Power
Authors: Honsho Yusuke , Nagayama Mayumi , Sasaki Kazunari , Hayashi Akari
Published: September 2020

For the future combined system of the renewable and hydrogen energy, the actual voltage fluctuation from wind power was applied to a single PEM water electrolysis cell, whose durability was studied. I-V performance of the water electrolysis cell increased up to 96-hour voltage fluctuation and slightly decreased after that. One of the reasons for such initial increase was found to decrease in activation overvoltage owing to increase in electrochemical active surface area of IrO2 through redox cycles derived by voltage fluctuation. Regarding to decrease in I-V performance after 96 h, increase in concentration overvoltage derived by temporary accumulation of produced gas inside the small pores of the electrode was a main reason. Furthermore, suppression of degradation of IrO2 was found when the voltage fluctuates lower than 1.5 V, indicating a potential of the water electrolysis system directly using renewable energy in the future.
Perfluorinated Anion Exchange Membranes for Alkaline Water Electrolysis
Authors: Nguyen Quynh-Mai , Jung Sung Yoon , Hwang Jin Pyo , Ahn Juhee , Lim Jun Hyun , Jang Wongi , Lee Chang Hyun
Published: September 2020

Anion exchange membranes (AEMs) have been getting great attraction in the field of alkaline water electrolysis because of their excellent barrier properties to hydrogen and oxygen. Here, we synthesized a perfluorinated AEM ionomer via one-step polycondensation reaction of a perfluorinated sulfonyl fluoride (PF-SO2F) precursor with the chemical architecture identical to Nafion® using N-phenylhydroxylamine (HPA). The synthesized NR-HPA ionomer was homogenously dispersed in an aqueous alcohol media via a supercritical fluid technique for AEM fabrication. The resulting AEM membrane has high OH- conductivity (e.g., 81 mS cm-1 at 90oC) and excellent chemical durability (e.g., ~200 hours at 80oC) even at the elevated temperatures. The electrochemical single cell performance was comparable to that of the state-of-the art alkaline membrane Zirfon® in the same measurement condition of 2 M KOH at 80oC.
Selective Permeation of Neodymium Through an Alloy Diaphragm in Molten Chloride Systems
Authors: Oishi Tetsuo , Yaguchi Miki , Katasho Yumi , Nohira Toshiyuki
Published: September 2020

As part of an ongoing study of a new recycling process for Nd-Fe-B permanent magnets, selective permeation of Nd through an RE-Ni (RE=Nd and Dy) alloy diaphragm was investigated in LiCl-KCl eutectic melts containing NdCl3 and DyCl3 or LaCl3 at 450°C. Selective permeation of Nd was achieved by controlling the potential of the alloy diaphragm, which functions as a bipolar electrode. Interestingly, EDX analysis revealed that the molar ratio of Nd/Dy in the alloy diaphragm was less than 0.05, which is two orders of magnitude lower than that of the permeated amount. These results suggest that the transportation rate of Nd atoms in the alloy diaphragm was extremely high compared to that of Dy. In order to obtain further insight into the transportation mechanism of RE atoms in the alloy diaphragm, STEM observations were also carried out. The results suggested that the transportation of RE atoms cannot be explained by simple grain boundary diffusion.
A Comparative Study of Imidazolium-Based Ionic Liquid-Single-Walled Carbon Nanotube Composites with Enhanced Conductivity Properties for Supercapacitor Applications
Authors: Hemraj-Benny Tirandai , Lall-Ramnarine Sharon I. , Suarez Sophia , Paterno Domenec , Ramdihal Jasodra D. , Sumner Rawlric , Urena Katelyn , Wishart James F.
Published: September 2020

Mixtures of ionic liquids (ILs) containing single-walled carbon nanotubes (SWCNTs) were prepared and characterized to obtain electrolytes with optimized transport properties for use in energy storage devices such as supercapacitors. Imidazolium ILs bearing cations with side chains of different functionality, coupled with bis(trifluoromethylsulfonyl)amide (NTf2
-) or bis(fluorosulfonyl)amide (FSA-) anions, were used in mixtures containing up to 5 wt% SWCNTs. At and above 2 wt% nanotube loading, the mixtures exhibited higher conductivities than the pure ILs, in spite of the extremely high viscosities. Loadings of 5 wt% produced very high conductivities, and studies of the temperature dependence indicated a change in the charge transport mechanism between 2 and 5 wt% loading. At 5 wt% loading, the highest conductivities (up to 540 mS/cm at 25°C) were obtained for the ILs containing the NTf2
- anion. These results can significantly contribute to the development of improved energy storage devices.
Conductivity of 1-Ethyl-3-Methylimidazolium Chloride (EMIC) and Aluminum Chloride (AlCl3) Ionic Liquids at Different Temperatures and AlCl3 Mole Fractions
Authors: Shinde Pravin , Ahmed Aninda N. , Nahian Md K. , Peng Yuxiang , Reddy Ramana G.
Published: September 2020

The conductivity (k) of ionic liquid (IL) comprising a melt of 1-ethyl-3-methylimidazolium chloride (EMIC) and aluminum chloride (AlCl3) with different AlCl3 mole fractions (XAl) and temperatures (343-383 K) are reported. XAl values of 0.6, 0.643, and 0.667 in EMIC-AlCl3 IL are selected to maintain the desired Lewis acidity. Precise and fast conductivity measurements and the behavior of anion species in IL are studied using electrochemical impedance spectroscopy (EIS). The measured k data followed the Arrhenius law using which the activation energies (E
a) of conduction are determined. The conductivity of EMIC-AlCl3 IL decreased with the higher XAl. EMIC-AlCl3 with XAl=0.6 exhibited higher k (5.58 S m–1) at 383 K and lowest E
a (4.25 KJ mol–1) among studied parameters. Based on the thermodynamic calculations, the differences in conductivities are attributed to the interplay of anion concentration, the molecular structure, cation-anion interactions, and hydrogen bonds in the IL.
Electrodeposition of Tungsten from Molten KF–KCl–WO3 and CsF–CsCl–WO3
Authors: Nohira Toshiyuki , Meng Xianduo , Ide Tatsuya , Norikawa Yutaro , Yasuda Kouji
Published: September 2020

The electrodeposition of W films was investigated in KF–KCl eutectic melts after adding 0.5–2.0 mol% of WO3 at 923 K. Cyclic voltammetry at a Ag electrode suggested that the electrodeposition of W from W(VI) ions proceeds from 1.65 V vs. K+/K. Electrodeposition of α-W was confirmed by XRD analysis. The effect of current density and added amount of WO3 on the morphology of W films was investigated by surface and cross-sectional SEM, which indicated that the best W film having thickness of ca. 15 μm was obtained at 12.5 mA cm−2 and 2.0 mol% of WO3. Although the film thickness was increased to ca. 30 μm by increasing the charge density, the surface roughness was significantly increased. To suppress the growth of crystal grains, electrodeposition of W was also investigated in CsF–CsCl eutectic melts at lower temperature of 873 K. The XRD confirmed the existences of both α-W and β-W in the W films. The SEM observations revealed that dense and smooth W films having thickness of ca. 30 μm was successfully obtained.
Anodic Behavior of MoSi2 in Molten MgCl2-NaCl-CaCl2 Containing Oxide Ions
Authors: Miyoshi Takamasa , Morishige Taiki , Takenaka Toshihide
Published: September 2020

The anodic behavior of MoSi2 in molten MgCl2-NaCl-CaCl2 containing oxide ions has been investigated in this study to aim at developing an inert anode in this melt. A sharp anodic current peak appeared around 1.8V (vs. Mg / Mg2+) in a cyclic voltammogram, which suggested that MoSi2 was passivated in the melt with oxide ions. An oxide film consisting of SiO2 and MgSiO3 was formed on MoSi2 by potentio-static electrolysis more positively than 1.6V (vs. Mg / Mg2+), and gas bubbles kept generating during the electrolysis. The current contributions assuming the dissolution of Mo and the formation of MgSiO3 were estimated from the weight change and the film thickness after potentio-static electrolysis. The current contribution other than the Mo dissolution and oxide film formation enlarged with the increase in the electrolysis duration and the raise in the electrolysis potential, and became above 90%. These results imply that MoSi2 is potential as an inert anode in molten MgCl2-NaCl-CaCl2 containing oxide ions.
Application of Phosphate Precipitation for Removing Strontium and Barium from Alkali Chloride Based Melts
Authors: Ivanov Alexander B. , Byzova Elizaveta D. , Volkovich Vladimir A. , Chukin Andrey V. , Griffiths Trevor R.
Published: September 2020

The reaction of solutions of barium and strontium chlorides in LiCl–KCl, NaCl–KCl, and NaCl–KCl–CsCl based melts with sodium orthophosphate was studied at 450 and 750oC. The initial phosphate-to-alkaline earth molar ratio varied from 0.5 to 14 and the excess of phosphate required for the complete conversion of AECl2 (AE = Sr, Ba) to phosphates as well as phase composition of the phosphates produced were determined. Normal orthophosphates alongside with lithium phosphate were formed in lithium chloride containing melts, whilst double alkali–alkaline earth phosphates and chloro-phosphates were obtained in NaCl–KCl and NaCl–KCl–CsCl based melts. Size of the particles comprising solid precipitates was determined; the values varied from 0.1 to tens microns. Increasing the initial PO4
3– : AE2+ molar ratio did not have a pronounced effect on the particle size.
Corrosion of Metallic Materials in 3LiCl-2KCl and 3LiCl-2KCl-UCl3
Authors: Alimgulov Ruslan R. , Trubcheninova Anastasia I. , Abramov Aleksandr V. , Zhilyakov Arkadiy Yu. , Belikov Sergey V. , Rebrin Oleg I. , Polovov Ilya B.
Published: September 2020

The corrosion of various metallic materials was investigated in 3LiCl–2KCl and 3LiCl–2KCl–UCl3 (5 wt. % U) melts under inert atmosphere. Metallic tantalum and molybdenum, nickel-chromium-molybdenum alloys (VDM® Alloy C-4, Hastelloy® G-35®, and specially designed KhN62M alloy) were investigated. The corrosion tests run for 100 h, and the temperature was varied from 450 to 750°C. The corrosion rates were determined by gravimetric technique and chemical analysis of quenched melts.