bluuebunny/crossref_metadata_2025 huggingface dataset:
Strategic equilibrium of economic dispatch in smart grid with a bi‐level game approach
Authors: Yang Jie , Guo Wenbo , Ma Kai , Tian Zhenhua , Dou Chunxia
Published: January 2020

It is necessary to design an economic dispatch mechanism to ensure the stability of the electricity market and the equilibrium of pricing strategy in a smart grid with real‐time pricing. In this study, the pricing strategy in the smart grid is analysed by modelling the economic dispatch problem as a bi‐level game in the electricity market, including the wholesale market and the retail market. In the wholesale market, the negotiation of the wholesale price between the generation company and multiple utility companies is formulated as a Nash bargaining problem. In order to guarantee the profit of the generation company and the social welfare of the utility companies simultaneously, the Nash bargaining solution is adopted to find an optimal wholesale price. In the retail market, the Shapley value is utilised to achieve profit distribution among the utility companies, and then a distributed gradient algorithm is proposed to search for the optimal retail price. Numerical results demonstrate the effectiveness of the proposed algorithm and the superiority of the economic dispatch strategy.
Screening potential and continuum lowering in a dense plasma under solar-interior conditions
Authors: Zeng Jiaolong , Li Yongjun , Gao Cheng , Yuan Jianmin
Published: January 2020

An accurate description of the screening potential induced by a hot, dense plasma is a fundamental problem in atomic physics and plasma physics, and it plays a pivotal role in the investigation of microscopic atomic processes and the determination of macroscopic physical properties, such as opacities and equations of state as well as nuclear fusion cross sections. Recent experimental studies show that currently available analytical models of plasma screening have difficulty in accurately describing the ionization-potential depression, which is directly determined by the screening potential. Here, we propose a consistent approach to determine the screening potential in dense plasmas under solar-interior conditions from the free-electron micro-space distribution. It is assumed that the screening potential for an ion embedded in a dense plasma is predominately determined by the free electrons in the plasma. The free-electron density is obtained by solving the ionization-equilibrium equation for an average-atom model to obtain the average degree of ionization of the plasma. The proposed model was validated by comparing the theoretically predicted ionization-potential depression of a solid-density Si plasma with recent experiments. Our approach was applied to investigate the screening potential and ionization-potential depression of Si plasmas under solar-interior conditions over a temperature range of 150–500 eV and an electron-density range of 5.88 × 1022–3.25 × 1024 cm−3. It can be easily incorporated into atomic-structure codes and used to investigate basic atomic processes, such as photoionization, electron-ion collisional excitation and ionization, and Auger decay, in a dense plasma.
The Effect of Different Processing Techniques in Sweet Potato (Ipomoea batatas) of Content Nutrition
Authors: Triasih Dyah , Utami Fitri Dwi
Published: January 2020

The objective of this study is to define the quality of sweet potato nutrition content in different processing techniques. Processing techniques were roasted, steamed, fried, and boiled. The research method was to experiment complete randomized design with four treatments and five replications for each treatment . The variables chemical quality test were water content, fat content, protein content, ash content, carbohydrate content, and total energy. The result of the chemical quality test showed processing techniques of sweet potato were significant influence water content, fat content, protein content, carbohydrate content, and analysis of total energy (P<0,05). The conclusion roasted processing techniques have higher levels of protein, carbohydrate content, and overall energy than others but have low on fat content, water content, and ash content.
Somatic-embryogenesis derived leaf-rust-tolerant clones of arabica coffee to deal with climate change
Authors: Arimarsetiowati Rina , Prastowo Erwin
Published: January 2020

The high-altitude coffee growing, Arabica, is likely subject to the global warming effect as they are prone to leaf-rust attacks at a higher temperature. It supplied 70% of world coffee production for its popularity concerning its delicacy and aromatic flavor. Utilization of, genetically, superior planting materials, i.e. leaf-rust-tolerant Arabica, has become an essential point, as may provide the potential solution to prevent the lost production due to leaf-rust attack. Andungsari 2K (AS 2K), S795, AS1, and Sigararutang are some of the potential leaf-rust-tolerant Arabica clones in Indonesia. Vegetative propagation by somatic embryogenesis may support the availability of superior plant materials quickly. The major aim of this experiment was to study the effect of different clones on germination step after the preliminary stage of direct-embryogenesis from leaf explants with combinations of medium between auxin (2,4-D) and cytokinin (2-ip). Embryo germination stage where embryoid was transferred to the germination medium consisting of MS medium without hormones. The results revealed that the growth location and texture of callus, as well as growth patterns and colour of embryogenic callus, were significantly influenced through the different combinations of medium and clones. The clone of S795 exhibits the highest embryo germination percentage of up to 100% within 8 weeks experiment period.
Development of a driftless Johnson noise thermometer for nuclear applications
Authors: Pearce Jonathan V. , Bramley Paul , Cruickshank David
Published: January 2020

Existing temperature sensors such as thermocouples and platinum resistance thermometers suffer from calibration drift, especially in harsh environments, due to mechanical and chemical changes (and transmutation in the case of nuclear applications). A solution to the drift problem is to use temperature sensors based on fundamental thermometry (primary thermometers) where the measured property is related to absolute temperature by a fundamental physical law. A Johnson noise thermometer is such a sensor and uses the measurement of the extremely small thermal voltage noise signals generated by any resistive element to determine temperature using the Johnson-Nyquist equation. A Johnson noise thermometer never needs calibration and is insensitive to the condition of the sensor material, which makes it ideally suited to long-term temperature measurement in harsh environments. These can include reactor coolant circuits, in-pile measurements, nuclear waste management and storage, and severe accident monitoring. There have been a number of previous attempts to develop a Johnson noise thermometer for the nuclear industry, but none have achieved commercialization because of technical difficulties. We describe the results of a collaboration between the National Physical Laboratory and Metrosol Limited, which has led to a new technique for measuring Johnson noise that overcomes the previous problems that have prevented commercialization. The results from a proof-of-principle prototype that demonstrates performance commensurate with the needs of nuclear applications is presented, together with details of progress towards the commercialization of the technology. The development partners have effected a step change in the application of primary thermometry to industrial applications and seek partners for field trials and further exploitation.
Development of a High Temperature Neutron Flux Detector
Authors: Martin Shaw , Campbell Bradley , Ballantine James , Roberts Kevin
Published: January 2020

Ultra Electronics, Energy is currently the supplier of neutron flux instrumentation to the UKs Advanced Gas Cooled Reactor (AGR) fleet. Neutron flux instrumentation provides a safety critical function, giving operators the fastest indication of any transient power behaviour in a nuclear reactor.

The operating requirements for these sensors in an AGR reactor are higher than those for equivalent instrumentation in a Pressurised Water Reactor (PWR) or Boiling Water Reactor (BWR). Whilst the underlying physics of these devices is the same, the engineering challenges for AGR instrumentation are different. Design and manufacturing processes have to be more precise due to susceptibility of device performance to a number of factors post installation.

The AGR sensor therefore provides a sound engineering platform for the development of an equivalent device for the harsh environments expected in Generation IV reactors.

This paper discusses the capabilities of the Ultra Electronics neutron flux detector manufacturing facility and how these capabilities are being expanded to cover the anticipated operating conditions for Generation IV reactor designs.

A prototype design has been manufactured and mechanically tested, the sensitive coating process has been developed and the Mineral Insulated (MI) signal cable has been tested at elevated temperature.
Predicting Ex-core Detector Response in a PWR
with Monte Carlo Neutron Transport Methods
Authors: Goričanec Tanja , Kotnik Domen , Štancar Žiga , Snoj Luka , Kromar Marjan
Published: January 2020

An approach for calculating ex-core detector response using Monte Carlo code MCNP was developed. As a first step towards ex-core detector response prediction a detailed MCNP model of the reactor core was made. A script called McCord was developed as a link between deterministic program package CORD-2 and Monte Carlo code MCNP. It automatically generates an MCNP input from the CORD-2 data. A detailed MCNP core model was used to calculate 3D power distributions inside the core. Calculated power distributions were verified by comparison to the CORD-2 calculations, which is currently used for core design calculation verification of the Krško nuclea power plant. For the hot zero power configuration, the deviations are within 3 % for majority of fuel assemblies and slightly higher for fuel assemblies located at the core periphery. The computational model was further verified by comparing the calculated control rod worth to the CORD-2 results. The deviations were within 50 pcm and considered acceptable. The research will in future be supplemented with the in-core and ex-core detector signal calculations and neutron transport outside the reactor core.
Non-Destructive Examination Development for the JHR Material Testing Reactor
Authors: Cornu B. , Roure C. , Moulin D. , Estre N. , Tisseur D. , Ferroud-Plattet M-P. , Kinnunen P. , Kotiluoto P. , Revuelta A.
Published: January 2020

The Jules Horowitz Reactor (JHR) is a European material testing reactor (MTR) under construction at the CEA Cadarache centre. It will be dedicated to material and fuel irradiation tests, as well as to the production of medical isotopes. Gamma and X-Ray benches will be implemented in the reactor pool (RER), the irradiated component storage pool (EPI) and in a shielded hot cell for measuring either the whole underwater test device still containing the experimental sample or just the experimental sample before its extraction in the hot cell.

The CEA/Cadarache Nuclear Measurement Laboratory (LMN) has been working in collaboration with VTT (Technical Research Centre in Finland Ltd.) since 2008 under a Finnish in-kind contribution agreement. This agreement focuses on the development of NDE systems implementing gamma-ray spectroscopy and high-energy X-ray imaging of the sample and irradiation device with the highest definition possible (resolution of 100 μm). The CEA-VTT technical specifications led to a European call for tenders launched by VTT. The contract was awarded to the Spanish company IDOM for the design, manufacturing, assembly and commissioning of: - Underwater gamma and X-ray (UGXR) mechanical benches and their associated gamma and X-ray collimation systems for the RER and EPI pools - Hot cell gamma and X-ray (HGXR) bench in the JHR NDE hot cell.

The Final Design Reviews (FDR) of the UGXR and HGXR systems were completed in 2016. The design phase has been an iterative process in order to manage interfacing specifications and constraints: - Challenging experimental requirements, mainly to cover the wide diversity of sample shapes, sample activity levels and measurement processes, but also to achieve a level of mechanical accuracy to reach the ambitious geometrical resolution target in X-ray imaging, - Environmental constraints (immersion, radiation, compactness, limited accessibility for maintenance), - Nuclear safety constraints (seism, radiation protection).

The whole design process has produced a number of elaborate and innovative mechatronic systems, which is rather unusual in nuclear applications since the resulting solutions have benefited from IDOM’s technological expertise in designing and commissioning large telescopes for the astronomy sector.

Once the manufacturing phase and assembly finalised, the site acceptance tests for the UGXR and HGXR mechanical systems will be performed in 2019-2020 in the TOTEM facility at the CEA Cadarache center. The underwater benches will be tested in the CESARINE pool to check their requirements.
Nuclear heating measurements by gamma and neutron thermometers
Authors: Van Nieuwenhove R. , Vermeeren L.
Published: January 2020

A gamma thermometer suitable for very high gamma heating levels (up to 20 W/g) has been designed and modelled by means of detailed finite element calculations. Based on a sensitivity analysis, the predicted accuracy of this gamma thermometer is better than 5 %. A novel miniaturized gamma thermometer is proposed in which a single thermocouple is used as the gamma absorption element, allowing a reduction of the sensor diameter down to 3 mm.

Monte Carlo calculations (by MCNP) have been performed to assess the relative contribution of neutrons to the nuclear heating in a gamma thermometer. Calculations have been performed for gamma thermometers with an inner body made of various materials, such as stainless steel, tungsten, molybdenum and rhodium. By using gamma thermometers made of different materials, it will be possible to deduce the nuclear heating rates in these materials and also to separate out the neutron and gamma heating contributions. The Monte Carlo calculations show that nuclear heating of rhodium is mainly due to neutrons, converting the rhodium gamma thermometer effectively in a neutron thermometer. The sensitivities of the gamma thermometers with W, Mo or Rh as heated materials have been modelled by finite element calculations. It is found that both the Mo and the Rh based sensor have a very linear response up to a nuclear heating of 20 W/g.
Neutron noise experiments in the AKR-2 and CROCUS reactors for the European project CORTEX
Authors: Lamirand Vincent , Rais Adolfo , Hübner Sebastian , Lange Carsten , Pohlus Joachim , Paquee Uwe , Pohl Christoph , Pakari Oskari , Frajtag Pavel , Godat Daniel , Hursin Mathieu , Laureau Axel , Perret Grégory , Fiorina Carlo , Pautz Andreas
Published: January 2020

The present article gives an overview of the first experimental campaigns carried out in the AKR-2 and CROCUS reactors within the framework of the Horizon 2020 European project CORTEX. CORTEX aims at developing innovative core monitoring techniques that allow detecting anomalies in nuclear reactors, e.g. excessive vibrations of core internals. The technique will be mainly based on using the fluctuations in neutron flux, i.e. noise analysis. The project will result in a deepened understanding of the physical processes involved. This will allow utilities to detect operational problems at a very early stage, and to take proper actions before such problems have any adverse effect on plant safety and reliability. The purpose of the experimental campaigns in the AKR-2 and CROCUS reactors is to produce noise-specific experimental data for the validation of the neutron noise computational models developed within this framework. The first campaigns at both facilities consisted in measurements at reference static states, and with the addition of mechanical perturbations. In the AKR-2 reactor, perturbations were induced by two devices: a rotating absorber and a vibrating absorber, both sets in experimental channels close to the core. In CROCUS, the project benefited from the COLIBRI experimental program: 18 periphery fuel rods were oscillated at a maximum of ±2 mm around their central position in the Hz range. The present article documents the experimental setups and measurements for each facility and perturbation type.
Remote monitoring of Molten Core-Concrete Interaction experiment with Optical Fibre Sensors & perspectives to improve nuclear safety – DISCOMS project
Authors: Maurin L. , Ferdinand P. , Bouyer V. , Denoix A. , Jouvin G. , Rougeault S. , Journeau C. , Molina D. , Tena P. , Ouerdane Y.
Published: January 2020

The DISCOMS project (Distributed Sensing for Corium Monitoring and Safety) aimed at providing innovative solutions not requiring local electrical power supplies, for remote monitoring of a severe nuclear accident. The solutions are based on both long length SPNDs (Self Powered Neutron Detectors) and on distributed OFSs (Optical Fibre Sensors) capable to detect the onset of a severe accident, the corium pouring on the containment building concrete basemat, and its interaction with the concrete floor under the reactor vessel, until it spreads in the core catcher (EPR case). This paper mainly focuses on these last three detection targets achievable with distributed OFSs. It is based on the results of a Molten Core & Concrete Interaction (MCCI) experiment, namely VULCANO, held in June 2018 with a concrete crucible equipped with overall ~ 180 m long optical fibre sensing cables. This small scale experiment (50 kg of prototypical corium) has demonstrated the ability of distributed OFSs to remotely provide useful data during the MCCI run: i) temperature profiles images up to about 580°C (single wavelength Raman DTS reflectometer) until cooling down to room temperature, ii) high spatial-resolution frequency shifts profiles, due to combined (non-selective) strain and temperature influences (Rayleigh OFDR and Brillouin reflectometers), and iii) cables lengths ablated by the corium on sections weakened by the temperature (Raman DTS, Rayleigh OFDR, telecom and photon counting reflectometers).
The Potential of Photon Activation and Neutron Activation Techniques for Fast Soil Characterization
Authors: Sari Adrien , Garti Sara , Lainé Frédéric , Carrel Frédérick , Dumazert Jonathan , Makil Hamid , Dufour Nicolas , Mougel Caroline , Masset Adeline , Mondon Lucile , Boutillon Laurent , Lejeune Jean-Pierre
Published: January 2020

In the frame of a partnership between CEA and VINCI, various measurement techniques are applied to soil analysis and tested in different laboratories located at CEA Saclay (France). This paper deals with two nuclear measurement techniques assessed in this project. More specifically, this paper presents the feasibility study carried out for two non-destructive active methods: photon activation and neutron activation. First, some atomic nuclides are activated either by photons or neutrons. Secondly, gamma-rays of specific energies are emitted by activated nuclides and gamma-ray spectrometry enables to identify these activated nuclides. Calibration of the full measurement system with reference samples would enable to quantify the mass of activated nuclides. Irradiations performed for photon activation measurements were conducted using a linear electron accelerator (linac) as the latter enables to generate high-energy photons byBremsstrahlungthanks to its conversion target. Furthermore, irradiations performed for neutron activation measurements were also conducted with a linac. Indeed, photons may be converted to neutrons by photonuclear reactions using a secondary target. In the frame of this project, experiments were carried out at the SAPHIR platform (CEA Saclay) with a Linatron-M9 VARIAN linac. The electron energy was either 6 or 9 MeV. For neutron activation measurements, a secondary target made of heavy water has been used as neutron source and a polyethylene cell enabled to thermalize neutrons and increase the number of reactions of interest. In this paper, we present the different experimental setups and the measurement protocols established for this feasibility study. We show experimental results obtained with raw material samples coming from three construction sites.
High-Performance Optimization of Algorithms Used in the BM@N Experiment of the NICA Project
Authors: Merts Sergei , Nemnyugin Sergei , Roudnev Vladimir , Stepanova Margarita
Published: January 2020

Results of high-performance optimization of BmnRoot software modules are
presented. The BmnRoot package used in the BM@N experiment of the NICA project plays a crucial role in the simulation and event reconstruction so its performance should be maximized to make the data processing efficient. Results of performance analysis on representative testcases are given and bottlenecks are localized. Most suitable approaches to BmnRoot optimization are chosen and numerical estimates of the scalability of the parallelized modules for event reconstruction are presented.
Quo vadis 116117? Bundesweiter Überblick über den Status quo und aktuelle Veränderungen
Authors: Breckner Amanda , Roth Catharina , Wensing Michel , Paulus Jan
Published: January 2020

Hintergrund Der ärztliche Bereitschaftsdienst (ÄBD) ist seit 2012 unter der bundeseinheitlichen Rufnummer 116117 erreichbar. Die Rufnummer ist dennoch in Deutschland noch nicht weitreichend bekannt. Eine Literaturrecherche zum Themengebiet der ambulanten Notfallversorgung hat gezeigt, dass Informationen lückenhaft und teilweise unübersichtlich sind. Ziel dieser Arbeit ist es den Status Quo der Strukturen der 116117 auf Länderebene zu erfassen.

Methode Im Februar 2019 wurden alle 17 KV-Bezirke schriftlich zur Beantwortung einer Online-Befragung eingeladen. Der Online-Fragebogen basiert auf einer ausgedehnten Literaturrecherche zum Themengebiet ambulante Notfallversorgung und ÄBD auf Länderebene innerhalb Deutschlands. Der Fragebogen umfasst mehrere Bereiche, hier wird auf die Rufnummer 116117 eingegangen. Die Daten wurden deskriptiv ausgewertet.

Ergebnis Die Organisation und das Leistungsspektrum sowie die Qualifikationen der Mitarbeiter der 116117 sind in den Bundesländern unterschiedlich strukturiert. Leistungen der 116117 umfassen die Vermittlung von Hausbesuchen, sowie an eine Bereitschaftsdienstpraxis, Beratung und die Weiterleitung an die 112. Das eingesetzte Personal reicht von MFAs über Pflegepersonal und Rettungsdienstpersonal bis hinzu Ärzten.

Schlussfolgerung Einheitliche Regelungen des Leistungsangebots und der eingesetzten Mitarbeiter können die Transparenz der 116117 auf Seiten der Patienten verbessern. Die geplante Erweiterung der 116117 um eine standardisierte medizinische Ersteinschätzung und die 24/7 Erreichbarkeit kann den Patienten die Zugangswege zu einer adäquaten medizinischen Versorgung erleichtern.
Two Case Reports of Integrated Management of Antibiotic-Resistant Urinary Tract Infection
Authors: Chand Kusum S. , Kapoor Priya
Published: January 2020

Background Urinary tract infections (UTIs) are frequent in women. Cystitis after intercourse (post-coital cystitis) accounts for 60% of recurrent cases. Most physicians treat recurrent UTIs (R-UTIs) with multiple courses of antibiotics. The high prevalence indicates that this bacteria-oriented approach in the long term is ineffective for many women. A change in clinical behavior regarding use of antibiotics and recognizing the importance of a patient’s self-defense mechanisms are important considerations in combating antimicrobial resistance.

Methods The intervention for each of two women with R-UTI was integrated treatment with a non-conventional and tailor-made homeopathy regimen, addressing multiple levels of disease simultaneously, for the prevention of recurrence as well as for treatment. Assessment of causal attribution of homeopathy treatment effect was carried out using the Modified Naranjo Criteria.

Results Case 1 presented with chronic multi-morbid conditions, including R-UTI which had become multi-drug resistant. With regular homeopathic treatment, her antibiotic use reduced, her diabetic profile improved, and she did not need prophylactic antibiotics. Case 2 suffered from R-UTI with post-coital cystitis and burning sensation, despite following all conventional advice for treatment and prophylaxis. Addition of homeopathy improved her quality of life and prevented relapses. The Modified Naranjo Criteria total score for each patient was +10/13 and +9/13, respectively.

Conclusions Addition of homeopathy can be an effective approach in integrated management of antibiotic-resistant R-UTIs. Controlled research on the topic is thus indicated.
Angiographic profile of coronary arteries in Keralite population
Authors: P. Apsara M
Published: January 2020

Background and aims: The incidence of Coronary Artery Disease (CAD) has reached alanning proportions in India. The pathological hall mark of CAD is myocardial ischemia resulting from the atherosclerotic narrowing of coronary arteries. In this era of advanced interventions and cardiac surgery, a thorough knowledge of normal and variant anatomy of coronary arteries is of prime significance and of great use both to the clinicians and anatomists. Materials and methods: One hundred coronary angiograms of patients free of disease were studied in detail in different profiles. The data obtained was quantified according to their frequencies. The relation between the length of left main coronary artery and coronary artery dominance was statistically analyzed using the 'Chi Square test for Trend'. Results: This study highlighted some interesting findings such as the origin of Sino- atrial nodal artery from the second segment of right coronary artery in 3% of cases, double right marginal artery in 4% cases. Other variations such as Mouchet's posterior recurrent interventricular artery, origin of circumflex artery from the right coronary artery and abnormal communication between the terminal parts of right coronary artery and circumflex artery were each noticed in 1 % of cases. Conclusions: Coronary arteries and their branches are prone to variations in their course and morphology. Prior knowledge about this is important for the interpretation of coronary angiograms and surgical myocardial revascularization. The present work on normal and variant pattern of coronary arteries will help in gathering momentum to the already advancing research work in this field.
Evaluation of Graft Tensioning Effects in Anterior Cruciate Ligament Reconstruction between Hamstring and Bone–Patellar Tendon Bone Autografts
Authors: DeFroda Steven F. , Karamchedu Naga Padmini , Budacki Ross , Wiley Taylor , Fadale Paul D. , Hulstyn Michael J. , Shalvoy Robert M. , Badger Gary J. , Fleming Braden C. , Owens Brett D.
Published: January 2020

This article investigates the clinical, functional, and radiographic outcomes in anterior cruciate ligament (ACL) reconstruction patients over 7 years to determine the effects of initial graft tension on outcomes when using patellar tendon (bone–tendon–bone [BTB]) and hamstring tendon (HS) autografts. Ninety patients, reconstructed with BTB or HS, were randomized using two initial graft tension protocols: (1) normal anteroposterior (AP) laxity (“low-tension”; n = 46) and (2) AP laxity overconstrained by 2 mm (“high-tension”; n = 44). Seventy-two patients had data available at 7 years, with 9 excluded for graft failure. Outcomes included the Knee Injury and Osteoarthritis Outcome Score, Short-Form-36 (SF-36), and Tegner activity scale. Clinical outcomes included KT-1000S and International Knee Documentation Committee examination score; and functional outcomes included 1-leg hop distance and peak knee extensor torque. Imaging outcomes included medial joint space width, Osteoarthritis Research Society International radiographic score, and Whole-Organ Magnetic Resonance Score. There were significantly improved outcomes in the high-tension compared with the low-tension HS group for SF-36 subset scores for bodily pain (p = 0.012), social functioning (p = 0.004), and mental health (p = 0.014) 84 months postsurgery. No significant differences in any outcome were found within the BTB groups. Tegner activity scores were also significantly higher for the high-tension HS group compared with the low-tension (6.0 vs. 3.8, p = 0.016). Patients with HS autografts placed in high tension had better outcomes relative to low tension for Tegner activity score and SF-36 subset scores for bodily pain, social functioning, and mental health. For this reason, we recommend that graft fixation be performed with the knee at 30-degree flexion (“high-tension” condition) when reconstructing the ACL with HS autograft.
Effect of Needle Exchange Program on Maternal Hepatitis C Virus Prevalence
Authors: Rossi Robert M. , Brady Matthew J. , Hall Eric S. , Warshak Carri R.
Published: January 2020

Objective This study aimed to quantify the prevalence of maternal hepatitis C virus (HCV) before and after implementation of the needle exchange program (NEP) in Scioto County, Ohio.

Study Design We conducted a population-based retrospective cohort study of all live births in Ohio (2006–2015). Frequency of maternal HCV was compared before (2006–2011) and after (2012–2015) the implementation of an NEP (2011) in Portsmouth, Ohio (Scioto County). Trends in maternal HCV prevalence in neighboring counties both physically adjacent and regional to Scioto County were also evaluated before and after NEP implementation.

Results During the study period, there were 7,069 reported cases of maternal HCV infection at the time of delivery among 1,463,506 (0.5%) live births in Ohio. The rate of maternal HCV infection increased 137% in Scioto County between 2006 and 2011. After initiation of the NEP in Portsmouth, Ohio, in 2011, the rate of increase in the following 4 years (2012–2015) was 12%. The rate of increase in maternal HCV declined precipitously in counties physically adjacent to Scioto County, whereas regional counties continued to have substantial increases in maternal HCV.

Conclusion Rate of maternal HCV infection increased 137% versus 12% (rate difference: 125%) between pre- and post-NEP implementation time periods in Scioto County.
The Role of Gender in Ophthalmology Resident Evaluations
Authors: Birnbaum Faith A. , Chandramouli Shivram , Thomas Mridul K. , Rosdahl Jullia A.
Published: January 2020

Background Gender affects various aspects of medical training. Prior research in surgical specialties has shown that female residents are given less positive feedback, granted less autonomy in the operating room, perform fewer procedures, and achieve competency milestones at a slower rate as compared with their male counterparts.

Purpose The purpose of this research is to evaluate whether gender affects ophthalmology resident evaluations at a single institution.

Methods Ophthalmology resident evaluations at a single residency program from 2010 to 2018 were reviewed. Data were collected on faculty gender, resident gender, and year of resident training. A linear mixed-effects model was utilized to analyze the degree to which differences in evaluation scores could be predicted from demographic data, while accounting for multiple sources of nonindependence of data.

Results A total of 490 evaluations for 43 residents by 34 faculty were analyzed. Evaluations consisted of up to 23 questions graded on a scale from 0 (poor) to 9 (excellent). Female residents received marginally higher scores than male residents on average (coefficient of male residents = −0.2). Both male and female residents received marginally lower scores from male faculty than from female faculty on average (coefficient of male faculty = −0.21). Male faculty also appeared to have scored male residents lower to a greater degree than did female faculty (coefficient of male faculty by male resident interaction = −0.14), though this result was sensitive to model specifications. There was no significant interaction between year of resident training and gender.

Conclusion In contrast to other procedural specialties, female residents appear to have been graded at a similar level or higher than male residents on average. Male faculty gave slightly lower scores to both male and female residents than female faculty did. Male faculty also may have graded male residents marginally lower than female residents to a greater degree than female faculty did.
Correction to: Bringing corporate governance into internalization theory: State ownership and foreign entry strategies
Authors: Grøgaard Birgitte , Rygh Asmund , Benito Gabriel R. G.
Published: January 2020

The article Bringing corporate governance into internalization theory.
The interaction effect of online review language style and product type on consumers’ purchase intentions
Authors: Liu Zhen , Lei Shao-hui , Guo Yu-lang , Zhou Zhi-ang
Published: January 2020

Previous research has proved that online reviews on purchased goods can observably affect consumers’ evaluation of products, purchase decisions, and purchase behaviors. This study classify online reviews into literal reviews and figurative reviews according to content features and language style. Product type is taken as a moderator to explore the impact of language style of online reviews on consumers’ purchase intentions from the perspective of social presence. Based on two studies in China, the matching between online language style and product type is explored, which has an interactive effect on consumers’ purchase intention. Social presence plays a mediating role. When purchasing search products, literal (vs. figurative) online reviews give consumers stronger social presence, resulting in higher purchase intentions. When purchasing experience products, consumers have stronger social presence because of figurative (vs. literal) online reviews, thus enhancing purchase intentions. The results not only expand the antecedent of social presence, but also offer several practical implications for online practitioners.
Quivers from Higgs bundles over P1 and quiver gauge theory
Authors: Hu Zhi , Huang Pengfei
Published: January 2020

In this paper, we associate a Higgs bundle over P1 with a Higgs quiver. We need to consider the Higgs representation of Higgs quivers, where the difference of Higgs representation from the usual linear representation is putting an OP1-module at each vertex in the quiver, and then changing the Higgs field on the underlying vector bundle is equivalent to changing the Higgs representations. We can also treat the space of Higgs fields as a space of the representations of the so-called Higgs structure quiver with the action of a reductive group. We produce some new quivers from the Higgs structure quiver and its representations, such as double quivers and Bogomol’nyi–Prasad–Sommerfield quivers related to quiver gauge theory, and study some topology of moduli space of corresponding stable representations, encoded in the structure of a Higgs bundle. We also introduce some algebraic structures on some vector spaces constructed from the Higgs structure quiver as the generalizations of classical Hall algebra and cohomological Hall algebra via bipartite quivers; the complexities of these algebraic structures are reflected in the nonassociativity of multiplications arising from preservation of some (Z2)r-graded structure.
Temperature-independent giant dielectric response in transitional BaTiO3 thin films
Authors: Everhardt Arnoud S. , Denneulin Thibaud , Grünebohm Anna , Shao Yu-Tsun , Ondrejkovic Petr , Zhou Silang , Domingo Neus , Catalan Gustau , Hlinka Jiří , Zuo Jian-Min , Matzen Sylvia , Noheda Beatriz
Published: January 2020

Ferroelectric materials exhibit the largest dielectric permittivities and piezoelectric responses in nature, making them invaluable in applications from supercapacitors or sensors to actuators or electromechanical transducers. The origin of this behavior is their proximity to phase transitions. However, the largest possible responses are most often not utilized due to the impracticality of using temperature as a control parameter and to operate at phase transitions. This has motivated the design of solid solutions with morphotropic phase boundaries between different polar phases that are tuned by composition and that are weakly dependent on temperature. Thus far, the best piezoelectrics have been achieved in materials with intermediate (bridging or adaptive) phases. But so far, complex chemistry or an intricate microstructure has been required to achieve temperature-independent phase-transition boundaries. Here, we report such a temperature-independent bridging state in thin films of chemically simple BaTiO3. A coexistence among tetragonal, orthorhombic, and their bridging low-symmetry phases are shown to induce continuous vertical polarization rotation, which recreates a smear in-transition state and leads to a giant temperature-independent dielectric response. The current material contains a ferroelectric state that is distinct from those at morphotropic phase boundaries and cannot be considered as ferroelectric crystals. We believe that other materials can be engineered in a similar way to contain a ferroelectric state with gradual change of structure, forming a class of transitional ferroelectrics. Similar mechanisms could be utilized in other materials to design low-power ferroelectrics, piezoelectrics, dielectrics, or shape-memory alloys, as well as efficient electro- and magnetocalorics.
Dirac energy spectrum and inverted bandgap in metamorphic InAsSb/InSb superlattices
Authors: Suchalkin Sergey , Ermolaev Maksim , Valla Tonica , Kipshidze Gela , Smirnov Dmitry , Moon Seongphill , Ozerov Mykhaylo , Jiang Zhigang , Jiang Yuxuan , Svensson Stefan P. , Sarney Wendy L. , Belenky Gregory
Published: January 2020

A Dirac-type energy spectrum was demonstrated in gapless ultrashort-period metamorphic InAsSb/InSb superlattices by angle-resolved photoemission spectroscopy (ARPES) measurements. The Fermi velocity value of 7.4 × 105 m/s in a gapless superlattice with a period of 6.2 nm is in good agreement with the results of magnetoabsorption experiments. An “inverted” bandgap opens in the center of the Brillouin zone at higher temperatures and in the superlattice with a larger period. The ARPES data indicate the presence of a surface electron accumulation layer.
The maximum likelihood climate change for global warming under the influence of greenhouse effect and Lévy noise
Authors: Zheng Yayun , Yang Fang , Duan Jinqiao , Sun Xu , Fu Ling , Kurths Jürgen
Published: January 2020

An abrupt climatic transition could be triggered by a single extreme event, and an α-stable non-Gaussian Lévy noise is regarded as a type of noise to generate such extreme events. In contrast with the classic Gaussian noise, a comprehensive approach of the most probable transition path for systems under α-stable Lévy noise is still lacking. We develop here a probabilistic framework, based on the nonlocal Fokker-Planck equation, to investigate the maximum likelihood climate change for an energy balance system under the influence of greenhouse effect and Lévy fluctuations. We find that a period of the cold climate state can be interrupted by a sharp shift to the warmer one due to larger noise jumps with low frequency. Additionally, the climate change for warming 1.5°C under an enhanced greenhouse effect generates a steplike growth process. These results provide important insights into the underlying mechanisms of abrupt climate transitions triggered by a Lévy process.
Investigation of nitride lateral Schottky barrier diodes based on InGaN channel heterostructures
Authors: Zhang Yachao , Wang Zhizhe , Zhao Shenglei , Xu Shengrui , Zhang Jincheng , Hao Yue
Published: January 2020

In this work, nitride lateral Schottky barrier diodes (SBDs) are manufactured on InGaN channel heterostructures, and the superior performances are investigated in detail. Due to the decent electron confinement of InGaN channel heterostructures, a high current on/off ratio of 107 is achieved for the SBDs. In addition, the turn-on voltage (Von) of lateral InGaN channel SBDs is as low as 0.55 V owing to the employment of a low work function tungsten (W) anode. Particularly, the excellent thermal stability of the InGaN channel SBDs is demonstrated. At 150 °C, the maximum forward anode current (Imax) reaches 63% of the value at room temperature, and the reverse leakage current only degenerates by 3.5 times compared to the room temperature value, which are evidently better than the results of traditional GaN channel SBDs. Moreover, the high linearity of InGaN channel SBDs at both room temperature and elevated temperature is revealed. These results demonstrate the great promise of lateral InGaN channel SBDs in high power and wideband electronics fields in the future.
Non-reciprocal acoustic transmission via space-time modulated membranes
Authors: Zhu Xiaohui , Li Junfei , Shen Chen , Peng Xiuyuan , Song Ailing , Li Longqiu , Cummer Steven A.
Published: January 2020

Non-reciprocity has recently attracted considerable attention as it enables new possibilities in wave manipulation and control. Here, we propose and analyze theoretically and numerically a waveguide system consisting of two membranes whose surface tensions are time-modulated with a phase difference between them. Strong non-reciprocity and low insertion loss can result for waves transmitted through the structure. An analytic approach is developed to calculate the harmonics generation in the system. Based on this approach, the optimal design of a two-membrane system for non-reciprocal wave behavior is then discussed. By suitably choosing the modulation parameters, the isolation factor for waves incident from opposite sides can reach as high as 19.8 dB and an insertion loss of only 2.8 dB, with an overall dimension being less than 1/3 wavelength. These theoretical results are verified by time-dependent finite element simulations. Our work provides a feasible way to design acoustic non-reciprocal devices.
Effects of hydrogen ion implantation dose on physical and electrical properties of Ge-on-insulator layers fabricated by the smart-cut process
Authors: Lim C.-M. , Zhao Z. , Sumita K. , Toprasertpong K. , Takenaka M. , Takagi S.
Published: January 2020

We experimentally evaluate the influence of a hydrogen ion implantation (I/I) dose on the physical and electrical properties of Ge-on-insulator (GOI) films fabricated by the smart-cut process with the two doses of 1 × 1017 cm−2 and 4 × 1016 cm−2. It is found that thermal annealing is effective in improving the crystallinity of the GOI layers and that the defect-less GOI layers can be realized under the optimized annealing temperature of 550 °C, irrespective of the I/I dose. However, the reduction of Hall hole mobility is observed in GOI substrates fabricated with higher I/I dose condition. This mobility reduction is not observed for GOI p-channel metal-oxide-semiconductor field-effect transistors (pMOSFETs) under the back-gate operation. On the other hand, n-channel MOSFETs fabricated on the smart-cut GOI substrates with As-doped S/D junctions are found to exhibit the higher effective electron mobility for the low I/I dose than that for the high I/I dose. As a result, it can be concluded that the high H+ I/I dose of 1 × 1017 cm−2 causes the degradation in the mobility of smart-cut GOI substrates and that the choice of the hydrogen I/I dose is important in the fabrication of GOI wafers for MOSFET applications.
Strong charge-density-wave order of large-area 2D metallic VSe2 nanosheets discovered by temperature-dependent Raman spectra
Authors: Jin Zhen , Zhou Jiaoyan , Xie Mingzhang , Ji Huan , Ye Yan , Jiang Kai , Shang Liyan , Zhang Jinzhong , Hu Zhigao , Chu Junhao
Published: January 2020

High-quality and large-area 1T-VSe2 nanosheets with different thicknesses on flat mica substrates are grown by ambient-pressure chemical vapor deposition. Temperature-dependent Raman spectra between 90 and 350 K have been performed to investigate the phenomena of the charge density wave (CDW) order. It can be found that the frequency of the A1g mode increases with the decreasing temperature. When the temperature reaches 110 K, the A1g mode abruptly converts to a low wavenumber. This phenomenon proves the CDW formation of VSe2 with the 5 nm thickness. It can be interpreted as arising from an enhanced electron–phonon coupling mechanism. Moreover, variable temperature-dependent Raman spectra for VSe2 with different thicknesses showed that the phase transition temperature gradually increased with the thickness. In addition, the CDW phase transition has also been detected by the abrupt change of the resistance, and its slope is located at about 112 K. The present results can be helpful for the potential applications of VSe2 crystals, such as spintronics devices and supercapacitors.
Tuning to more compressible phase in TiZrHfNb high entropy alloy by pressure
Authors: Zhang Kai , Peng Shang , Li Nana , Liu Xuqiang , Zhang Mingjian , Wu Yi-Dong , Yang Yanping , Greenberg Eran , Prakapenka Vitali B. , Hui Xidong , Wang Yandong , Yang Wenge
Published: January 2020

In this work, the starting nominal Ti25Zr25Hf25Nb25 high entropy alloy (HEA) has two body centered cubic (BCC) phases with a volume percentage about 100:1, with the primary phase having a much larger bulk modulus (incompressible) than the uniform single-phase HEA. We found that these two phases merged into one single BCC phase at pressures beyond 36 GPa, whose bulk modulus dropped to that of the normal homogeneous HEA. After decompressing, the new phase can be sustained to ambient conditions. This abnormal pressure-induced softening was largely related to the lattice distortion evolution and interfacial energy during compression.
Spatially multi-scale artificial neural network model for large eddy simulation of compressible isotropic turbulence
Authors: Xie Chenyue , Wang Jianchun , Li Hui , Wan Minping , Chen Shiyi
Published: January 2020

In this work, subgrid-scale (SGS) stress and SGS heat flux of compressible isotropic turbulence are reconstructed by a spatially multi-scale artificial neural network (SMSANN). The input features of the SMSANN model are based on the first order derivatives of the primary and secondary filtered variables at different spatial locations. The SMSANN model performs much better than the gradient model in the a priori test, including the correlation coefficients and relative errors. Specifically, the correlation coefficients of the SGS stress and SGS heat flux can be larger than 0.997 and the relative errors of the SGS stress and SGS heat flux can be smaller than 0.08 for the SMSANN model. In an a posteriori analysis, the performance of the SMSANN model has been evaluated by a detailed comparison of the results of the SMSANN model and the dynamic mixed model (DMM) at a grid resolution of 643 with the Taylor Reynolds number Reλ ranging from 180 to 250. The SMSANN model shows an advantage over the DMM in the prediction of the spectra of velocity and temperature. Besides, the SMSANN model can accurately reconstruct the statistical properties of velocity and temperature and the instantaneous flow structures. An artificial neural network with consideration of spatial multiscale can deepen our understanding of large eddy simulation modeling.