bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation of a bidirectional DC/DC converter with zero‐voltage switching operation for battery interfaces
Authors: Bhajana Veera Venkata Subrahmanya Kumar , Drabek Pavel , Jara Martin , Popuri Madhuchandra , Iqbal Atif , B. Chitti Babu
Published: January 2021

This paper proposes a bidirectional DC–DC converter with soft‐switching capabilities. The main characteristic of this converter is that it can be operated in both boost and buck modes. The major advantages of this converter are high efficiency and reduced switching loss in high‐power and high‐voltage applications. The soft‐switching capability is obtained by additional dual auxiliary resonant circuits connected to the conventional non‐isolated bidirectional DC–DC converter. Except for the auxiliary switches, all main switches turn on with zero‐voltage switching in this proposed bidirectional DC–DC converter. The auxiliary switches turn off with zero current transition. The principle of operation, theoretical analysis and experimental results of a 175 V/385 V bidirectional DC–DC converter at 2 kW output power with switching frequency of 50 kHz are provided. The experimental results verified the zero‐voltage switching operation for boost and buck modes with efficiencies 96.5% and 96%, respectively, at full load.
Field orientation based three‐coil decoupled wireless transmitter for electric vehicle charging with large lateral receiver misalignment tolerance
Authors: Nie Shuang , Pathmanathan Mehanathan , Yakop Netan , Luo Zhichao , Lehn Peter W.
Published: January 2021

A three‐coil decoupled transmitter is developed for the inductive power transfer system of electric vehicle charging. The three‐coil decoupled transmitter consists of three overlapping rectangular coils with magnetic mutual decoupling and is capable of overcoming large receiver lateral misalignment up to 20 cm. A current optimization method is advanced to derive transmitter coil currents for the multi‐phase system that minimizes the coil loss through optimizing the current distribution among transmitter coils. The optimized current distribution reduces the maximum leakage flux by around 40% compared to the best alternative excitation method. The compensation strategy provides unity power factor for high‐power transfer phases and allows a single set of compensation capacitors to be used regardless of receiver alignment. The three‐coil decoupled transmitter is compatible with a typical three‐phase inverter for industrial practical application, which halves the power electronic switches used with previous topologies. The simulation verification is performed at 3.3 kW, achieving 93.76% efficiency at perfect alignment and 92.54% efficiency at 20 cm misalignment. The experimental verification is implemented at 3.3 kW with 200 mm ground clearance, realizing a 92.97% efficiency at perfect alignment and 90.57% efficiency at 20 cm misalignment.
Experimental efficiency analysis of a solar panel electricity generation system using planar reflection
Authors: Duranay Mehmet , Turmus Ahmet , Tanyildizi Vedat
Published: January 2021

Since energy consumption in all countries of the world is increasing day by day, the demand and interest on renewable energy resources are also increasing at the same rate. Using the current energy in the best way and searching for different energy sources have become an important field of study for countries. Studies on this area also continue in our country, which is lucky in terms of solar energy potential. In this experimental study, where the design and production stages were carried out interactively, the effect of reflected rays on the photovoltaic (PV) panel was observed and the comparison of reflected rays with direct rays was made. The system following the Sun and the system fixed at an appropriate angle was compared. Also, the theoretical and the experimental efficiency as a result of the experimental study of the movable and fixed system were calculated and compared for the direct and reflected radiation. The mechanism presented in this study allows more use of solar radiation by enhancing through reflection from surface‐to‐surface. With this experimental study more solar radiation will be provided with the panel placed on the back, in addition to the panel exposed to direct solar radiation. Thus, it will be possible to use double‐faced panels for a solar tracking system.
Distributed event‐triggered robust automatic generation control for networked power system with wind turbines
Authors: Huo Zhihong
Published: January 2021

This paper proposes an event‐triggered distributed networked control scheme and its robust stability analysis strategy for the automatic generation control of multi‐area interconnected power system with wind turbines. First, for the large‐scale distributed networked control systems, considering the networked control systems with parameters uncertainty, effective transmission bandwidth, and time‐varying networked‐induced delays, a new distributed networked control systems model is proposed. Then, by constructing Lyapunov–Krasovskii functional method, the sufficient conditions for asymptotical stability of the system are obtained, a design method of event‐triggered distributed networked control law based on linear matrix inequality is proposed. In order to verify the effectiveness of the proposed scheme, a multi‐area power system with wind turbines is considered, and the system performance under different load disturbances is simulated. The simulation results show that the scheme has reliable robust performance for multi‐area distributed networked power system and improves the anti‐interference ability of the power system.
ARI and ARID control of virtual synchronous generator for frequency response improvement
Authors: Rathore B. , Chakrabarti S. , Srivastava L.
Published: January 2021

The modern power system is progressing from a centralised generation having synchronous generators to the distributed generation having the large‐scale integration of renewable energy sources. These renewable energy sources are interfaced with the system through the inverter. Due to the inertia‐less nature of inverter, the system becomes prone to frequency instability. The virtual synchronous generator control is used to enhance the frequency stability by introducing virtual inertia in the inverter control. The virtual synchronous generator technique provides flexibility to the researchers to regulate swing equation parameters in real‐time. Based on this concept, this paper proposes an auto‐regulated inertia control as the first contribution to improve the damping effect of virtual synchronous generator control. In the literature, the primary focus is on the inertia control and negligible importance is given to the damping factor control. Therefore, to show the effect of dynamic damping factor, together with dynamic virtual inertia, on the transient stability; an auto‐regulated inertia and damping factor control of virtual synchronous generator is proposed as the second contribution. Simulation results of the proposed techniques are compared with the various virtual inertia control techniques in the real‐time digital simulator environment. The results show that auto‐regulated inertia and damping factor control is the most effective method to provide dynamic frequency support to the microgrid.
Smart electric motor: Evaluation of business potential for digitalisation in the large electric motor industry
Authors: Costello Timothy Joe , Strunz Kai , Müller‐Kirchenbauer Joachim
Published: January 2021

Digitalisation is seen to have contributed to the demise of 50% of the Fortune 500 companies since 2000. The large electric motor segment is not immune to this changing business landscape and must evolve to survive. This sector is experiencing declining revenues as traditional hardware‐sales‐focused business models have proved inadequate to address a reduction in profitability. New business models that exploit new digital value streams are to leverage the value from emerging technologies of the Industrial Internet of Things, Big Data and the associated emerging predictive analytics. These can be optimised via Cloud Computing and delivered utilising Platform as a Service software solutions to reduce cost and support scalability. The missing link in the justification chain for the installation of digitalisation packages on large electric motors is a model to determine if and which package sections return the most customer value and, therefore, sales opportunities for the supplier. In this context, this paper introduces the concept of the smart electric motor. The focus is on the oil and gas industry, where digitalisation is already deeply engrained in practice and shows how risk‐based decisions can deliver a profitable project through new business models and digitalised solutions to reinvigorate this traditional industry.
Image processing and machine learning‐based classification method for hyperspectral images
Authors: Yaman Orhan , Yetiş Hasan , Karaköse Mehmet
Published: January 2021

Hyperspectral images are used to produce effective solutions in many areas due to the number of information they have. However, the number of information they provide may not bring an advantage always, in contrast, it may cause confusion sometimes. In this study, we propose a machine learning‐based classification method on the reduced bands using median and mean filters. The proposed method is tested on Indian Pines, Pavia University and Salinas datasets. After applying normalization, median filter and mathematical morphology for each band in an image, a feature matrix with only one band is achieved. Then, the most significant features are selected by using relief feature selection algorithm. The selected features are used for classification with support vector machine and K nearest neighbourhood. For all methods and datasets, a success rate above 99% in terms of accuracy is achieved. The proposed method has two significant contributions. First, when the proposed method is compared with the similar studies in the literature, it is clearly seen that the features selected by relief algorithm significantly increase the success rate of classification algorithms. Second significant contribution of using relief algorithm is obtaining faster methods by reducing the number of hyperspectral bands.
A neural network-based methodology to select young stellar object candidates from IR surveys
Authors: Cornu D. , Montillaud J.
Published: January 2021

Context. Observed young stellar objects (YSOs) are used to study star formation and characterize star-forming regions. For this purpose, YSO candidate catalogs are compiled from various surveys, especially in the infrared (IR), and simple selection schemes in color-magnitude diagrams (CMDs) are often used to identify and classify YSOs.

Aims. We propose a methodology for YSO classification through machine learning (ML) using Spitzer IR data. We detail our approach in order to ensure reproducibility and provide an in-depth example on how to efficiently apply ML to an astrophysical classification.

Methods. We used feedforward artificial neural networks (ANNs) that use the four IRAC bands (3.6,  4.5,  5.8, and 8 μm) and the 24 μm MIPS band from Spitzer to classify point source objects into CI and CII YSO candidates or as contaminants. We focused on nearby (≲1 kpc) star-forming regions including Orion and NGC 2264, and assessed the generalization capacity of our network from one region to another.

Results. We found that ANNs can be efficiently applied to YSO classification with a contained number of neurons (∼25). Knowledge gathered on one star-forming region has shown to be partly efficient for prediction in new regions. The best generalization capacity was achieved using a combination of several star-forming regions to train the network. Carefully rebalancing the training proportions was necessary to achieve good results. We observed that the predicted YSOs are mainly contaminated by under-constrained rare subclasses like Shocks and polycyclic aromatic hydrocarbons (PAHs), or by the vastly dominant other kinds of stars (mostly on the main sequence). We achieved above 90% and 97% recovery rate for CI and CII YSOs, respectively, with a precision above 80% and 90% for our most general results. We took advantage of the great flexibility of ANNs to define, for each object, an effective membership probability to each output class. Using a threshold in this probability was found to efficiently improve the classification results at a reasonable cost of object exclusion. With this additional selection, we reached 90% and 97% precision on CI and CII YSOs, respectively, for more than half of them. Our catalog of YSO candidates in Orion (365 CI, 2381 CII) and NGC 2264 (101 CI, 469 CII) predicted by our final ANN, along with the class membership probability for each object, is publicly available at the CDS.

Conclusions. Compared to usual CMD selection schemes, ANNs provide a possibility to quantitatively study the properties and quality of the classification. Although some further improvement may be achieved by using more powerful ML methods, we established that the result quality depends mostly on the training set construction. Improvements in YSO identification with IR surveys using ML would require larger and more reliable training catalogs, either by taking advantage of current and future surveys from various facilities like VLA, ALMA, or Chandra, or by synthesizing such catalogs from simulations.
Excitation and evolution of coronal oscillations in self-consistent 3D radiative MHD simulations of the solar atmosphere
Authors: Kohutova P. , Popovas A.
Published: January 2021

Context. Solar coronal loops are commonly subject to oscillations. Observations of coronal oscillations are used to infer physical properties of the coronal plasma using coronal seismology.

Aims. Excitation and evolution of oscillations in coronal loops is typically studied using highly idealised models of magnetic flux tubes. In order to improve our understanding of coronal oscillations, it is necessary to consider the effect of realistic magnetic field topology and evolution.

Methods. We study excitation and evolution of coronal oscillations in three-dimensional (3D) self-consistent simulations of solar atmosphere spanning from the convection zone to the solar corona using the radiation-magnetohydrodynamic (MHD) code Bifrost. We use forward-modelled extreme-ultraviolet emission and 3D tracing of magnetic field to analyse the oscillatory behaviour of individual magnetic loops. We further analyse the evolution of individual plasma velocity components along the loops using wavelet power spectra to capture changes in the oscillation periods.

Results. Various types of oscillations commonly observed in the corona are present in the simulation. We detect standing oscillations in both transverse and longitudinal velocity components, including higher-order oscillation harmonics. We also show that self-consistent simulations reproduce the existence of two distinct regimes of transverse coronal oscillations: rapidly decaying oscillations triggered by impulsive events and sustained small-scale oscillations showing no observable damping. No harmonic drivers are detected at the footpoints of oscillating loops.

Conclusions. Coronal loop oscillations are abundant in self-consistent 3D MHD simulations of the solar atmosphere. The dynamic evolution and variability of individual magnetic loops suggest that we need to re-evaluate our models of monolithic and static coronal loops with constant lengths in favour of more realistic models.
Ergebnisse nach Pankreaseingriffen aus Sicht der Betroffenen: Versorgungsforschung der Selbsthilfegruppe „Arbeitskreis der Pankreatektomierten e. V.“
Authors: Dimopoulos Ioannis , Meyer Gabriele , Elhabash Saleem Ibrahim , Sorleto Michele , Gartung Carsten , Ewald Nils , Fetzner Ulrich Klaus , Otto Lutz , Möhlenbrock Friedhelm , Uhl Waldemar , Gerdes Berthold
Published: January 2021

Hintergrund Im Jahr 1976 gründete sich die Selbsthilfeorganisation „Arbeitskreis der Pankreatektomierten e. V.“ (AdP). Sie ist mit über 1000 Mitgliedern die mit Abstand größte Gruppe von Betroffenen mit Pankreaserkrankungen in Deutschland. AdP-Mitgliedern kommt aufgrund ihrer Betroffenenkompetenz eine bedeutende Unterstützungsfunktion für Ratsuchende zu. Die vorliegende, von Patienten veranlasste Querschnitts- und Versorgungsforschungsstudie hat das Ziel, Ergebnisse nach Pankreasoperationen aus Patientensicht zu erheben.

Methode Allen Mitgliedern des AdP wird seit dem 03.03.2018 ein Fragebogen zu 11 Themenkomplexen zugestellt. Die Daten werden in eine pseudonymisierte Datenbank aufgenommen.

Ergebnisse 625 pankreasoperierte Patienten nahmen an der Studie teil (Rücklaufquote 55,4 %). 57,5 % erhielten Pankreaskopfresektionen, 15,5 % Pankreaslinksresektionen, 23,2 % Pankreatektomien und 4,0 % einen sonstigen oder nicht spezifizierten Eingriff. Bei 37,9 % wurde ein Pankreaskarzinom diagnostiziert, bei 38,2 % ein sonstiger Pankreastumor, bei 25 % eine Pankreatitis, bei 4 % eine Autoimmunpankreatitis und bei 2,7 % andere seltene Erkrankungen. Ein Teil der Patienten hatte mehr als eine Pankreaserkrankung.

Unter den 237 operierten Pankreaskarzinompatienten lebten 82 Patienten länger als 5 Jahre und davon 41 Patienten länger als 10 Jahre. 24,5 % der Karzinompatienten hatten Zweitkarzinome und 13,9 % nahe Verwandte mit einem Pankreaskarzinom.

Nach Pankreasoperationen war der Gewichtsverlust eingriffsabhängig beträchtlich, am größten perioperativ nach Pankreatektomie (17,8 ± 9,5 kg). Die Diabetesprävalenz betrug 54,1 %, die Inzidenz perioperativer Diabetesneuerkrankungen 33,3 %. 91,5 % benötigten postoperativ eine Lipasesubstitution im Mittel von 189 417 IE/Tag. Die Lebensqualität (körperlich/seelisch/sozial) zeigte sich von der Operationsart unabhängig.

Schlussfolgerung Patienten nach komplexen Pankreasresektionen sind zeitlebens mit Einschränkungen im täglichen Leben konfrontiert. Selbsthilfeorganisationen wie der AdP können einen wichtigen, jedoch bislang wenig genutzten Beitrag zur Erforschung dieser Erkrankungen leisten, und zwar einerseits durch den Perspektivwechsel, andererseits durch Generierung großer Patientenkollektive, z. B. die sehr große Gruppe der Langzeitüberlebenden.
Kurative Radiochemotherapie von Kopf-Hals-Tumoren
Authors: Langer Christine , Wittekindt Claus , Jensen Alexandra Désirée
Published: January 2021

Radio- und Chemotherapie stellen sowohl als definitiver Therapieansatz als auch im adjuvanten Setting wesentliche Bestandteile der Behandlung von malignen Kopf-Hals-Tumoren dar. Der Behandlungserfolg ist hier wesentlich abhängig von Auswahl und Dosierung der verwendeten Substanzen sowie vom spezifischen radiotherapeutischen Setting in Bezug auf Fraktionierung, Therapiegesamtdauer und Bestrahlungstechnik.

Hinzu kommen Untersuchungen zur immunologisch basierten Therapie und strahlentherapeutischen Modifikation durch Evaluation der Partikeltherapie innerhalb oder additiv zu etablierten Behandlungskonzepten. Die Therapie HPV-induzierter Tumoren stellt aufgrund der differenten Tumorbiologie und des damit verbundenen verbesserten Gesamtüberlebens eine weitere aktuell untersuchte therapeutische Herausforderung dar.
Management of Deep Spinal Wound Infections Following Instrumentation Surgery with Subfascial Negative Pressure Wound Therapy
Authors: Rickert Marcus , Rauschmann Michael , Latif-Richter Nizar , Arabmotlagh Mohammad , Rahim Tamin , Schmidt Sven , Fleege Christoph
Published: January 2021

Background and Study Aims The treatment of infections following a spine surgery continues to be a challenge. Negative pressure wound therapy (NPWT) has been an effective method in the context of infection therapy, and its use has gained popularity in recent decades. This study aims to analyze the impact of known risk factors for postoperative wound infection on the efficiency and length of NPWT therapy until healing.

Patients and Methods We analyzed 50 cases of NPWT treatment for deep wound infection after posterior and posteroanterior spinal fusion from March 2010 to July 2014 retrospectively. We included 32 women and 18 men with a mean age of 69 years (range, 36–87 years). Individual risk factors for postoperative infection, such as age, gender, obesity, diabetes, immunosuppression, duration of surgery, intraoperative blood loss, and previous surgeries, as well as type and onset (early vs. late) of the infection were analyzed. We assessed the associations between these risk factors and the number of revisions until wound healing.

Results In 42 patients (84%), bacterial pathogens were successfully detected by means of intraoperative swabs and tissue samples during first revision. A total of 19 different pathogens could be identified with a preponderance of Staphylococcus epidermidis (21.4%) and S. aureus (19.0%). Methicillin-resistant S. aureus (MRSA) was recorded in two patients (2.6%). An average of four NPWT revisions was required until the infection was cured. Patients with infections caused by mixed pathogens required a significantly higher number of revisions (5.3 vs. 3.3; p < 0.01) until definitive wound healing. For the risk factors, no significant differences in the number of revisions could be demonstrated when compared with the patients without the respective risk factor.

Conclusion NPWT was an effective therapy for the treatment of wound infections after spinal fusion. All patients in the study had their infections successfully cured, and all spinal implants could be retained. The number of revisions was similar to those reported in the published literature. The present study provides insights regarding the effectiveness of NPWT for the treatment of deep wound infection after spinal fusion. Further investigations on the impact of potential risk factors for postoperative wound healing disorders are required. Better knowledge on the impact of specific risk factors will contribute to a higher effectiveness of prophylaxis for postoperative wound infections considering the patient-specific situation.
Comparison of the Pharmacokinetic Properties of Extended Half-Life and Recombinant Factor VIII Concentrates by In Silico Simulations
Authors: Bukkems Laura H. , Preijers Tim , van Spengler Max W. F. , Leebeek Frank W. G. , Cnossen Marjon H. , Mathôt Ron A. A.
Published: January 2021

Background The pharmacokinetic (PK) properties of extended half-life (EHL) factor VIII (FVIII) concentrates differ, leading to variation in the optimal dosing regimen for the individual patient. The aim of this study was to establish these PK differences for various EHL FVIII concentrates by in silico simulations.

Methods FVIII level over time profiles of rFVIII-SC, BAY 81–8973, rFVIII-Fc, BAX 855, BAY 94–9027, and standard half-life (SHL) rFVIII concentrates were simulated for 1,000 severe hemophilia A patients during steady-state dosing of 40 IU/kg every 72 hours or dosing as advised in the summary of product characteristics (SmPC).

Results Although the elimination half-life values were comparable for rFVIII-FC, BAX 855, and BAY 94–9027, a higher area under the curve (AUC; 2,779 IU/h/dL) for BAY 94–9027 was obtained. During steady-state dosing of 40 IU/kg every 72 hours, 58.5% (rFVIII-SC), 69.3% (BAY 81–8972), 89.0% (rFVIII-Fc), 83.9% (BAX 855), and 93.7% (BAY 94–9027) of the patients maintained a trough level of 1 IU/dL, compared with 56.0% for SHL rFVIII. Following dosing schemes described in the SmPC, between 51.0 and 65.4% or 23.2 and 31.1% of the patients maintained a target trough level of 1 IU/dL or 3 IU/dL, respectively.

Conclusion BAY 94–9027 showed the largest increase of AUC and best target attainment compared with SHL rFVIII, followed closely by BAX 855 and rFVIII-Fc. BAY 81–8973 and rFVIII-SC showed smaller PK improvements. Although our analyses increase insight into the PK of these FVIII concentrates, more studies evaluating the relation between factor levels and bleeding risk are needed.
Stem Cell Treatment for Ischemic Stroke Recovery
Authors: Kondziolka Douglas
Published: January 2021

The role of cellular transplantation to promote functional recovery after stroke has been evaluated over the last two decades. Preclinical studies first established the potential for cultured neuronal cells derived from a teratocarcinoma cell line to be tested for safety and efficacy in the treatment of human stroke. In animal models of stroke that caused reproducible learning and motor deficits, injection of neuronal cells resulted in a return of learning behavior, retention time, and motor function. Clinical trials followed. Additional work with cells derived from a bone marrow neuroprogenitor line, fetal cortical stem cells, and other cell sources showed promise in preclinical studies and then these cells were tested in clinical studies. This report reviews the different biological repair approaches using cell implants, discusses clinical trial design and surgical methods, and the current state of research.
The Initiation of Long-Term Pharmacotherapy in Schizophrenia: Dosage
and Side Effect Comparisons Between Oral and Depot Fluphenazine*
Authors: Schooler Nina R. , Levine J. ,   and the NIMH-PRB Collaborative Fluphenazine Study Group
Published: January 2021

This report focuses on two comparisons between oral and depot fluphenazine
specifically FPZ decanoate: 1) can equivalent dosages for the two drugs be
established and do these equivalencies change over six months of treatment; 2)
what are the side effects seen with the two drugs during the early weeks of
administration.

Patients in the study receive either oral or depot FPZ as the active treatment
but in order to preserve double blind conditions, they are also given the other
treatment in placebo form. No dosage equivalence is established by the protocol,
however, if dosage is adjusted, both forms must be changed and in the same
direction. During the first weeks of treatment there is a linear relationship
between the two dosage forms but a range of relatively low dosages of the oral
compound (5-20 mg) is associated with a single dose (25 mg/q 3 weeks) of FPZ
decanoate. At higher dosages of the oral drug the relationship is linear.

Side effects of some kind are noted in over 60 percent of patients in both
treatment groups after four weeks of treatment, while symptoms of at least
moderate severity occur in almost 40 percent. Only symptoms involving the
extrapyramidal system and sleep disturbance are observed in more than 20 percent
of the patients.

Benztropine was prescribed only if needed and was administered to 65 percent of
patients. In general, those receiving benztropine had more side effects than
those who did not. These differences reached significance for extrapyramidal
symptoms and depression.

Based on these data, we conclude that at the dosages used in this study there are
no side effect differences between these two forms of fluphenazine in the early
weeks of administration. Dosage equivalence between the two drugs can be set
within the range of 5- 60 mg/day oral and 12.5-100 mg/three weeks depot.
Temperature likely has no effect on the transmission of COVID-19
Authors: McConnon Aili
Published: January 2021

Using COVID-19 viral mimicking particles, researchers determine temperature does not impact the spike protein structure or interaction with lung cells
Misalignment of Optical Fibers Allows Manipulation of Single Cells
Authors: Larter Raima
Published: January 2021

Investigators report a device that allows multimodal manipulation of single cells using the forces exerted by two misaligned laser beams.
Electron transport of perovskite oxide BaSnO3 on (110) DyScO3 substrate with channel-recess for ferroelectric field effect transistors
Authors: Cheng Junao , Yang Hao , Combs Nicholas G. , Wu Wangzhou , Kim Honggyu , Chandrasekar Hareesh , Wang Caiyu , Rajan Siddharth , Stemmer Susanne , Lu Wu
Published: January 2021

We report an electron transport study of an La-doped perovskite oxide BaSnO3 thin film grown by molecular beam epitaxy on (110) DyScO3 as a function of electron concentration, by etching the film step-by-step with nanometer precision. Inductively coupled plasma-reactive ion etching with BCl3/Ar plasma is used for etching depth control. The local doping and electron density are experimentally determined after each etching step. The results show that the electron mobility is dominated by threading dislocations if the electron concentration is below 7.8 × 1019 cm−3, while ionized impurities and phonon scattering become more dominant at electron concentrations greater than 1.2 × 1020 cm−3. The charging state of thread dislocations is estimated to be 6.2. Furthermore, using the etch process to control the electron concentration and channel thickness, a gate-recessed ferroelectric field effect transistor is fabricated with 10 nm HfO2 as a gate dielectric. The device exhibits a saturation current of 29.9 mA/mm with a current on/off ratio of Ion/Ioff = 8.3 × 108 and a ferroelectric polarization charge density of 1.9 × 1013 cm−2. Under the forward gate bias sweep, the device operates in the enhancement mode with a threshold voltage of 3 V. Under the reverse gate sweeping bias, the device operates in the depletion mode with a threshold voltage of –1.5 V.
Effect of low-concentration steam on carbon dioxide adsorption by bituminous coal
Authors: Gao Zheng Hong , Wang Jiren
Published: January 2021

A combination of experiments and molecular simulations was used to analyze the influence of different humidity values on the adsorption of CO2 on the surface of bituminous coal. First, the fixed bed dynamic adsorption method was used. A self-developed dynamic humidity control adsorption device was used to measure the penetration curves at different CO2 concentrations in the dry and wet states and to analyze the relevant dynamic processes. Second, molecular simulations were used to construct an amorphous cell model similar to the experimental sample, and the adsorption process and density distribution were simulated and analyzed. Finally, a comparative analysis of experimental and simulated data was performed. The results of the experiment showed that the CO2 adsorption of coal samples increased from 0.0291 mmol g−1 to 0.0871 mmol g−1 upon increasing the CO2 concentration. At low CO2 concentrations, the presence of water vapor inhibited CO2 adsorption on the surface of bituminous coal, advanced the CO2 breakthrough curve, and decreased the adsorption amount. This phenomenon gradually became more apparent upon increasing the CO2 concentration. When the CO2 concentration reached 4%, the adsorption reduction affected by water vapor reached the critical value of 5.5%, the adsorption capacity of the inhibited group was 0.0515 mmol g−1, and then the effect gradually weakened. When the CO2 concentration reached 7%, the adsorption capacity was almost unaffected by water vapor.
An engineering application of Prosperetti and Lezzi equation to solve underwater explosion bubbles
Authors: Zhang Jingxiao , Wang Shushan , Jia Xiyu , Gao Yuan , Ma Feng
Published: January 2021

The dynamic behaviors of underwater explosion bubbles differ for different explosives. The explosive characteristic parameters will result in a greater impact on the motion characteristics of the bubbles. Based on the bubble dynamics equation established by Prosperetti and Lezzi [“Bubble dynamics in a compressible liquid. Part 1. First-order theory,” J. Fluid Mech. 168, 457âĂŞ-478 (1986); “Bubble dynamics in a compressible liquid. Part 2. Second-order theory,” J. Fluid Mech. 185, 289âĂŞ-321 (1987)], we proposed an initial condition and an equation of state (EOS) form applicable for calculating the underwater explosion bubble dynamics of different explosives. With the assumption of instantaneous detonation and initial shock wave formation at the gas–liquid boundary, we calculated the initial state of the bubble boundary and established the initial condition for calculating explosion bubbles. Using the Jones–Wilkins–Lee EOS for different explosives, we constructed an isentropic EOS with a polytropic exponent that varied with density. We calculated and analyzed the differences in the initial expansions and the subsequent oscillations of underwater explosion bubbles with different explosives as well as the effects of different explosive parameters on the explosion bubble dynamics. This study showed that the proposed initial condition and the EOS form with a polytropic exponent that varied with density yielded good calculation accuracy and achieve close association of the underwater explosion bubbles with the properties of the explosive detonation and the characteristics of the detonation products. In addition, the explosion bubbles differed in the initial expansion, where the bubbles produced by explosives with higher densities and greater detonation velocities expanded more rapidly.
A SA-CASSCF and MS-CASPT2 study on the electronic structure of nitrosobenzene and its relation to its dissociation dynamics
Authors: Soto Juan , Peláez Daniel , Otero Juan C.
Published: January 2021

The photodissociation channels of nitrosobenzene (PhNO) induced by a 255 nm photolytic wavelength have been studied using the complete active space self-consistent method and the multistate second-order multiconfigurational perturbation theory. It is found that there exists a triplet route for photodissociation of the molecule. The reaction mechanism consists of a complex cascade of nonadiabatic electronic transitions involving triple and double conical intersections as well as intersystem crossing. Several of the relevant states (S2, S4, and S5 states) correspond to double excitations. It is worth noting that the last step of the photodissociation implies an internal conversion process. The experimentally observed velocity pattern of the NO fragment is a signature of such a conical intersection.
New approach to analyze the band structure characteristics of one-dimensional photonic system
Authors: Sun Lulu , Wu Di , Wei Manli , Ma Ji
Published: January 2021

In this paper, we employ three dimensionless system parameters, induced by the contrast of the wave vector, geometric size, and wave impedance of two materials, to analyze the band structure characteristics of a one-dimensional photonic system. We have obtained the dependence relationships of the bandgap position, width, and depth on the dimensionless system parameters. Moreover, we also work out the relationships between the wave vector and geometric size contrast ratios, which can reveal the occurrence of topological phase transitions. These properties should be especially helpful for manipulating the bandgap in novel devices based on a one-dimensional photonic system.
X-ray photons produced from a plasma-cathode electron beam for radiation biology applications
Authors: Gobet F. , Barberet P. , Courtois L. , Deves G. , Gardelle J. , Leblanc S. , Plawinski L. , Seznec H.
Published: January 2021

A compact low-energy and high-intensity x-ray source for radiation biology applications is presented. A laser-induced plasma moves inside a 30 kV diode and produces a beam of 1014 electrons at the anode location. An aluminum foil converts a part of the energy of these electrons into x-ray photons, which are characterized using filtered imaging plates. The dose that would be deposited by these x-ray photons in C. elegans larvae is calculated from Geant4 simulations. It can be set to a value ranging between 10 μGy and 10 mGy per laser shot by simply changing the aluminum foil thickness and the diode voltage. Therefore, this versatile and compact x-ray source opens a new path to explore the radiation effects induced by dose rates varying over several orders of magnitude.
Investigation of device transport characteristics enhancement of In0.53Ga0.47As MOSFET through in situ NH3/N2 remote-plasma treatment
Authors: Huang P. , Luc Q. H. , Sibaja-Hernandez A. , Hsu C. W. , Wu J. Y. , Ko H. L. , Tran N. A. , Collaert N. , Chang E. Y.
Published: January 2021

In this work, we demonstrated considerable enhancement of the transport characteristics of n-type Al2O3/In0.53Ga0.47As metal-oxide-semiconductor field-effect transistors (n-MOSFETs) with the assistance of in situ NH3/N2 remote-plasma (RP) treatment. According to the measurement and simulation results, the RP treated sample shows superior device performances as compared to the control sample without plasma treatment including (a) improved on-current (Ion) from 8.5 mA/mm to 17 mA/mm, (b) improved transconductance (Gm) from 16.05 mS/mm to 28.52 mS/mm, (c) suppressed subthreshold swing from 189 mV/dec to 170 mV/dec, (d) suppressed drain induced barrier lowering from 36 mV/V to 28 mV/V, (e) intensified peak effective mobility (μeff) from 1896 cm2 V−1 s−1 to 2956 cm2 V−1 s−1, and (f) reduced acceptor-type density of interface trap state (Dit,A) to 44%. By using TCAD simulation, device output performance is found to be dramatically impacted by the trap state (especially acceptor-type) at the Al2O3/InGaAs interface.
Reinterpreting the vibrational structure in the electronic spectrum of the propargyl cation (H2C3H+) using an efficient and accurate quantum model
Authors: Ouyang Zheming , Xie Changjian
Published: January 2021

The B̃1A1 ← X̃1A1 absorption spectra of propargyl cations H2C3H+ and D2C3D+ were simulated by an efficient two-dimensional (2D) quantum model, which includes the C—C stretch (v5) and the C≡C stretch (v3) vibrational modes. The choice of two modes was based on a scheme that can identify the active modes quantitively by examining the normal coordinate displacements (∆Q) directly based on the ab initio equilibrium geometries and frequencies of the X̃1A1 and B̃1A1 states of H2C3H+. The spectrum calculated by the 2D model was found to be very close to those calculated by all the higher three-dimensional (3D) quantum models (including v5, v3, and another one in 12 modes of H2C3H+), which validates the 2D model. The calculated B̃1A1 ← X̃1A1 absorption spectra of both H2C3H+ and D2C3D+ are in fairly good agreement with experimental results.
Ring polymer quantization of the photon field in polariton chemistry
Authors: Chowdhury Sutirtha N. , Mandal Arkajit , Huo Pengfei
Published: January 2021

We use the ring polymer (RP) representation to quantize the radiation field inside an optical cavity to investigate polariton quantum dynamics. Using a charge transfer model coupled to an optical cavity, we demonstrate that the RP quantization of the photon field provides accurate rate constants of the polariton mediated electron transfer reaction compared to Fermi’s golden rule. Because RP quantization uses extended phase space to describe the photon field, it significantly reduces the computational costs compared to the commonly used Fock state description of the radiation field. Compared to the other quasi-classical descriptions of the photon field, such as the classical Wigner based mean-field Ehrenfest model, the RP representation provides a much more accurate description of the polaritonic quantum dynamics because it alleviates the potential quantum distribution leakage problem associated with the photonic degrees of freedom (DOF). This work demonstrates the possibility of using the ring polymer description to treat the quantized radiation field in polariton chemistry, offering an accurate and efficient approach for future investigations in cavity quantum electrodynamics.
Dual-fiber microfluidic chip for multimodal manipulation of single cells
Authors: Huang Liang , Feng Yongxiang , Liang Fei , Zhao Peng , Wang Wenhui
Published: January 2021

On-chip single-cell manipulation is imperative in cell biology and it is desirable for a microfluidic chip to have multimodal manipulation capability. Here, we embedded two counter-propagating optical fibers into the microfluidic chip and configured their relative position in space to produce different misalignments. By doing so, we demonstrated multimodal manipulation of single cells, including capture, stretching, translation, orbital revolution, and spin rotation. The rotational manipulation can be in-plane or out-of-plane, providing flexibility and capability to observe the cells from different angles. Based on out-of-plane rotation, we performed a 3D reconstruction of cell morphology and extracted its five geometric parameters as biophysical features. We envision that this type of microfluidic chip configured with dual optical fibers can be helpful in manipulating cells as the upstream process of single-cell analysis.
Effects of Mn-doping on anti-fatigue and anti-leakage current characteristics in KNN single crystals
Authors: Zhang Yao , Meng Xiangda , Huang Fei , Hu Chengpeng , Tan Peng , Wang Yu , Huang Xiaolin , Zhou Zhongxiang , Tian Hao
Published: January 2021

In this work, we illuminate the influences of Mn doping on the domain structure, ferroelectric properties, and piezoelectric properties of K0.4Na0.46NbO3 (KNN) lead-free single crystals. We simultaneously obtained a low leakage current and high anti-fatigue properties in Mn:KNN single crystals. The valence state of the Mn ion changes after annealing from trivalent to bivalent. The micro-domain structure images show that the domain structure of Mn-doped KNN single crystals is more complex with a smaller size. In addition, the occupying mechanism of Mn in KNN is discussed. Moreover, ion doping is of great significance to the further study of low leakage resistance and good anti-fatigue properties for KNN-based ferroelectric materials.
Rev
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w of Scientific Instruments New Products
Authors: Mandelis Andreas
Published: January 2021

In order to supplement manufacturers’ information, this department will welcome the submission by our readers of brief communications reporting measurements on the physical properties of materials, which supersede earlier data or suggest new research applications.
Time dependence of magnetic moment of strontium-ferrite powder measured with a biaxial vibrating sample magnetometer (VSM)
Authors: Ahmed Tanjina Nasreen , Belduque Maria Camila , Binod D. C. , Tate Jitendra S. , Geerts Wilhelmus J.
Published: January 2021

The magnetic hysteresis and viscosity of SrO(Fe2O3)6/PA-12 filaments with 5wt% and 26wt% was determined with a biaxial VSM. The hysteresis curves indicate that manufactured samples have a flow induced anisotropy with an easy plane perpendicular to the filament’s cylindrical axis. The Mx and My magnetic viscosity signals vary with field and field angle. The Mx magnetic viscosity is maximum in the easy plane and decreases to a factor of two along the macroscopic hard axis of the filament. The My magnetic viscosity is nearly zero along the hard axis and in the easy plane and is maximum for intermediate field angles.
Guidelines for effective evaluation and comparison of wildland fire occurrence prediction models
Authors: Phelps Nathan , Woolford Douglas G.
Published: January 2021

Daily, fine-scale spatially explicit wildland fire occurrence prediction (FOP) models can inform fire management decisions. Many different data-driven modelling methods have been used for FOP. Several studies use multiple modelling methods to develop a set of candidate models for the same region, which are then compared against one another to choose a final model. We demonstrate that the methodologies often used for evaluating and comparing FOP models may lead to selecting a model that is ineffective for operational use. With an emphasis on spatially and temporally explicit FOP modelling for daily fire management operations, we outline and discuss several guidelines for evaluating and comparing data-driven FOP models, including choosing a testing dataset, choosing metrics for model evaluation, using temporal and spatial visualisations to assess model performance, recognising the variability in performance metrics, and collaborating with end users to ensure models meet their operational needs. A case study for human-caused FOP in a provincial fire control zone in the Lac La Biche region of Alberta, Canada, using data from 1996 to 2016 demonstrates the importance of following the suggested guidelines. Our findings indicate that many machine learning FOP models in the historical literature are not well suited for fire management operations.
Seed production.
Authors: Morgan Lynette
Published: January 2021

Seeds are effective and efficient plant reproductive and dispersal structures consisting of an embryo, food supply and protected covering. As the start of the next generation, seeds occupy a critical position in plant life history and in the survival of the species (Black et al., 2000). Seed husbandry formed the basis for early agriculture and eventual civilization. People learned to plant, harvest, and preserve the seeds of certain grasses for winter and they abandoned nomadic life to build permanent settlements (Copeland and McDonald, 2001). Long viability has allowed seeds to be passed from generation to generation, with some, e.g. the Indian lotus (Nelumbo nucifera) remaining viable for as long as 1000 years (Janick, 1986). Seeds are remarkably varied and diverse. The orchid species boasts the smallest known seed, a dust-like particle hardly visible to the naked eye (Copeland and McDonald, 2001). Large perennial plants typically have the heaviest seed size, e.g. coconut.. Shape ranges from round or oval in many seed species, to triangular, elliptic, elongated, spiked, thorned, and hairy or winged, depending on the natural method of disposal. Together with differences in size and shape, seeds are highly diverse in a number of other aspects, many of which are relevant to horticultural production and seed technology which has developed to address such issues as seed dormancy, viability and storage life.
Abuse is not a zero‐sum game! The case for zero tolerance of match official physical and verbal abuse
Authors: Dawson Peter , Webb Tom , Downward Paul
Published: January 2021

Emergent research has investigated the impact of abuse on the decision of match officials to leave their sport. The existing literature is largely descriptive and qualitative. Based on large surveys of football referees in France and the Netherlands, this paper investigates the factors that are associated with the verbal and physical abuse of the referees and also the association of this abuse with the intentions of referees to quit officiating. The associations are investigated by estimating the marginal effects from bivariate probit and probit models respectively. Bivariate probit estimation reveals a strong correlation between each form of abuse. Both, unsurprisingly, are also positively associated with years of experience of referees. Probit estimation reveals that both forms of abuse, as well as intimidation from refereeing certain teams, are associated with an increased consideration of referees to quit. As increased intention to quit is also associated with the experience of the referee it is likely that the effect of abuse on referee considerations of quitting increase through time. The main conclusions are that the alternative forms of abuse are not zero‐sum and both should be targeted by governing bodies to reduce the decline in the number of football referees. The data show that support of referees, for example through mentoring, can offset stated intentions to quit.

Highlights

This study looks at the factors that are associated with verbal and physical abuse of football referees and the association of this abuse with the intentions to quit.

The alternative forms of abuse are not zero‐sum and both should be targeted to reduce the decline in referees.

Support of referees, for example through mentoring, can offset stated intentions to quit.