bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of hydrogen and oxygen plasma on the photoelectronic current and photo-response time of SnS2 flakes
Authors: Xia Minggang , Hu Ruixue , Wang Min , Liu Shiru , He Shaodan , Cheng Zhaofang 
Published: February 2021

Abstract
The photoelectronic properties of SnS2 flakes have been widely studied due to the abundance and environmentally friendly qualities of this material. However, the defects and residual molecules adsorbed on the SnS2 surface can have a negative influence on the photoelectronic current and photo-response time. In this paper we examine the effects of these two factors on the photoelectronic currents of SnS2 flakes. Defects on a single crystal SnS2 surface are fabricated using hydrogen and oxygen plasma and are characterized by atomic force microscopy, confocal micro-Raman spectroscopy and photoluminescence spectroscopy. Doping by oxygen plasma can be demonstrated by x-ray photoelectron spectroscopy. Both the photoelectronic current and the switching speed (on and off times) are reduced after hydrogen plasma treatment. However, oxygen plasma has two effects on SnS2 thin film transistors. First, oxygen plasma can remove the residual molecules within a short irradiation time. In this case, the photoelectronic current of SnS2 treated with oxygen plasma is enhanced several times. Second, with a longer treatment time oxygen plasma induces many defects and doping on the SnS2 flake surface, as reflected in the reduced photoelectronic current and switching speed. Results of this work have significant practical applications for photoelectronic detection with SnS2 flakes.
Old enemy, new threat: you can’t solve today’s problems with yesterday’s solution
Authors: Rehani Madan M 
Published: February 2021

Abstract
The radiation protection principles of justification, optimization, and dose limitation as enumerated by the International Commission on Radiological Protection have been guiding light for the profession for over three decades. The dose limitation does not apply to medical exposure but keeping patients’ doses low is achieved through optimization, particularly by developing and using diagnostic reference levels (DRLs). There are new findings that demonstrate that despite using the best possible approaches to justification and optimization including as well use of DRLs, a very large number of patients are receiving doses in excess of 100 mSv of effective dose or organ doses exceeding 100 mGy. A non-ignorable fraction of patients is receiving such high doses in a single day. The magnitude of such patients creates the need for a relook into the principles with the intent to understand what can be done to attend to today’s problems. A look at other areas such as approaches, and principles used in the pharmaceutical industry and in traffic management throws some light into what can be learnt from these examples. It appears that the system needs to be enriched to deal with the protection of the individual patient. The currently available approaches and even the principles are largely based on the protection of the population or group of patients. The third level of justification for individual needs further refinement to take into account series of imaging many patients are needing, and cumulative radiation doses involved, many of which happen in a short duration of 1 to 5 years. There is every likelihood of patient radiation doses continuing to increase further that underscores the need for timely attention. This paper provides several suggestions to deal with the situation.
GUI for Bayesian sample size planning in type A uncertainty evaluation
Authors: Martin Jörg , Elster Clemens 
Published: February 2021

Abstract
We present a graphical user interface (GUI) for planning the sample size needed to reach a specified target uncertainty in a Bayesian type A uncertainty evaluation of normal or Poisson distributed data. To this end we build on a criterion previously introduced by Martin and Elster (2020 Stat. Methods Appl. 1–21) and called the variation of the posterior variance criterion. This criterion includes, and extends, standard Bayesian sample size planning procedures. Guidance is provided for the elicitation of the required prior knowledge in a way that makes the approach easily accessible for metrologists. The GUI also includes a menu that performs the Bayesian inference after the experiment has been carried out.
Measurement of boundary layer transition on oscillating airfoil using cntTSP in low-speed wind tunnel
Authors: Ikami Tsubasa , Fujita Koji , Nagai Hiroki , Yorita Daisuke 
Published: February 2021

Abstract
cntTSP is a flow visualization technique that combines temperature-sensitive paint (TSP) and carbon nanotube (CNT). TSP is a sprayable temperature sensor, and CNT is used as a thin inner electric heater for the TSP. The cntTSP technique allows the visualization of the movement of the boundary layer transition on a moving airfoil. In this study, cntTSP was applied to a pitch-oscillating airfoil in a low-speed wind tunnel. Three methods were compared as methods for detecting the boundary layer transition position. The transition position was successfully evaluated using a heat transfer coefficient that was calculated by the surface temperature. Moreover, at a high-reduced frequency, the detected transition positions were different between the pitching-up and pitching-down procedure. Moreover, we observed a hysteresis loop of the transition position.
A reversible and stable doping technique to invert the carrier polarity of MoTe2
Authors: Aftab Sikandar , Samiya Ms , Raza Ali , Iqbal Muhammad Waqas , Haque Hafiz Mansoor Ul , Ramachandraiah Karna , Yousuf Saqlain , Jun Seong Chan , Rehman Atteq Ur , Iqbal Muhammad Zahir 
Published: February 2021

Abstract
Two-dimensional (2D) materials can be implemented in several functional devices for future optoelectronics and electronics applications. Remarkably, recent research on p–n diodes by stacking 2D materials in heterostructures or homostructures (out of plane) has been carried out extensively with novel designs that are impossible with conventional bulk semiconductor materials. However, the insight of a lateral p–n diode through a single nanoflake based on 2D material needs attention to facilitate the miniaturization of device architectures with efficient performance. Here, we have established a physical carrier-type inversion technique to invert the polarity of MoTe2-based field-effect transistors (FETs) with deep ultraviolet (DUV) doping in (oxygen) O2 and (nitrogen) N2 gas environments. A p-type MoTe2 nanoflake transformed its polarity to n-type when irradiated under DUV illumination in an N2 gaseous atmosphere, and it returned to its original state once irradiated in an O2 gaseous environment. Further, Kelvin probe force microscopy (KPFM) measurements were employed to support our findings, where the value of the work function changed from ∼4.8 and ∼4.5 eV when p-type MoTe2 inverted to the n-type, respectively. Also, using this approach, an in-plane homogeneous p–n junction was formed and achieved a diode rectifying ratio (If/Ir) up to ∼3.8 × 104. This effective approach for carrier-type inversion may play an important role in the advancement of functional devices.
Teaching the moment of inertia by measuring the angular speed with a smartphone’s sensors
Authors: Puttharugsa Chokchai , Chatchawaltheerat Theerawat , Teeratchanan Pattanasak 
Published: February 2021

Abstract
This paper demonstrates the use of the sensors of a smartphone in recording experimental data for studying the moment of inertia of a compound pendulum. The smartphone was attached to the beam to record at various points the angular position and angular speed of a compound pendulum. We altered the position of the smartphone along the beam resulting in the change of the system’s moment of inertia. The experimental result agreed with the theoretical calculation. This experiment will stimulate students to conduct such an experiment themselves and helps students understand the relationship between angular speed and its moment of inertia.
Development of a cryogenic indentation tool with in situ optical observation, application to the mechanical characterization of II–VI semiconductors
Authors: Broult T , Kerlain A , Destefanis V , Guinedor P , Bourhis E Le , Patriarche G 
Published: February 2021

Abstract
Infrared detectors based on II–VI semiconductors are cooled from room temperature (RT) to cryogenic temperatures between 80 K and 150 K in order to operate with strong requirements regarding sensor performances for infrared detection. At these cryogenic temperatures, the mechanical properties of II–VI alloys have to be known in detail to improve handling, use and lifetime of infrared sensors. We have developed a cryogenic indentation tool and in situ measured the mechanical properties of CdZnTe alloys at both RT and 90 K. CdZnTe hardness increases by a factor of about 3 when cooling from RT to 90 K, from 0.6 GPa to 1.6 GPa. The plastic flow driving mechanism shows at least two different domains with activation energies around 0.01 eV at low temperatures and around 0.05 eV at RT, showing an increase by a factor of about 5. These two domains might be ‘connected’ by an intermediate domain in the 235 K–290 K temperature range. Radial cracks can be in situ detected. Toughness of CdZnTe alloys also increases dramatically by a factor of about 2 with cooling down to cryogenic temperature from 0.13 MPa.m1/2 at RT to 0.25 MPa.m1/2 at 90 K.
Proton irradiation effects on buffer-free gallium nitride on silicon carbide high electron mobility transistor-based radio frequency power amplifier
Authors: Raut Samriddhi , Sehra Khushwant , Mishra Meena , Rawal D S , Gupta Mridula , Saxena Manoj 
Published: February 2021

Abstract
In this work, a comprehensive technology computer aided design-based investigation of a buffer-free high electron mobility transistor under proton radiation is presented. With a 37.55% thinner architecture (without thick and highly doped Fe buffer) grown on silicon carbide substrate, this device design improves the two-dimensional electron gas (2DEG) confinement and helps to eliminate the various dispersion effects and buffer leakage. To gain better insight into the buffer-free device architecture, direct current (DC), thermal, and radio frequency (RF) studies are carried out. To establish the various prospects of this device in high-power and space applications, the performance of the device under 1.8 MeV proton radiation environment is systematically studied. A comparison demonstrates that the buffer-free structure under proton radiation with fluence

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degradation of 18.68% compared with 72.7% in the case of conventional architecture. The excellent capability of the buffer-free device to confine 2DEG more precisely even under radiation environments can be concluded from the various DC and RF parameters studied. An extensive study of the effects of proton fluences and biases on the RF power amplifier figures of merit was also conducted by carrying out harmonic balance simulations for different radiation setups, which demonstrates excellent performance of the buffer-free structure.
Exploiting ferroelectric and ferroelastic effects in piezoelectric energy harvesting: theoretical studies and parameter optimization
Authors: Behlen Lennart , Warkentin Andreas , Ricoeur Andreas 
Published: February 2021

Abstract
While piezoelectric energy harvesting typically focuses on converting mechanical into electrical energy on the basis of the linear reversible piezoelectric effect, the potential of exploiting the non-linear ferroelectric effect is investigated theoretically in this paper. Due to its dissipative nature, domain switching, on the one hand, is basically avoided in order to prevent mechanical energy from being converted into heat. However, the electrical output, on the other hand, is augmented due to the increased change of electric displacement. In view of these conflicting issues, one main objective in ferroelectric energy harvesting thus is to identify mechanical and electrical process parameters providing appropriate figures of merit. Being an efficient approach to numerically simulate multiphysical polycrystalline material behavior, the so-called condensed method is taken as a basis for the investigation and finally optimization of controllable parameters of ferroelectric energy harvesting cycles. A first idea of a technical implementation taken from literature is considered as cycle of reference, constituting the starting point of the present study, being focused on material aspects rather than on harvesting devices. Different quality assessing parameters are introduced, taking into account general aspects of harvesting efficiency as well as the ratio of irreversible switching-related to reversible piezoelectric contributions. Residual stresses are likewise predicted to give an idea of reliability and the risk of fracture. Two types of cycles and associated optimal process parameters are finally presented.
Calculation of electronic and optical properties of 1550 nm VCSEL based on Group IV elements
Authors: Li Hongqiang , Zhang Sai , Zhang Yikai , Ding Mingjun , Lu Xinyan , Daniel Prades Joan 
Published: February 2021

Abstract
Si/SiGe quantum well (QW) structures show considerable potential in revolutionising Si photonics. This study proposes a novel 1550 nm vertical cavity surface-emitting laser (VCSEL) that is based on Group IV elements and composed of Si/SiO2 distributed Bragg reflectors and Si/Si0.13Ge0.87 QWs. Material composition and QW width in the active region are optimised. The proposed Group IV-based VCSEL can exhibit epitaxial growth on a vertical binary blazed grating coupler and increase coupling efficiency relative to the traditional Group III–V-based VCSEL with an Si waveguide. The proposed VCSEL on Si based on the Group IV element scheme is a cheap, high-yielding and temperature-insensitive on-chip light source that can be used in large-scale, high-density monolithic integration.
New structures for closed-form wave solutions for the dynamical equations model related to the ion sound and Langmuir waves
Authors: Alam Md Nur , Osman M S 
Published: February 2021

Abstract
This treatise analyzes the coupled nonlinear system of the model for the ion sound and Langmuir waves. The modified

(
G
′

/

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)

-expansion procedure is utilized to raise new closed-form wave solutions. Those solutions are investigated through hyperbolic, trigonometric and rational function. The graphical design makes the dynamics of the equations noticeable. It provides the mathematical foundation in diverse sectors of underwater acoustics, electromagnetic wave propagation, design of specific optoelectronic devices and physics quantum mechanics. Herein, we concluded that the studied approach is advanced, meaningful and significant in implementing many solutions of several nonlinear partial differential equations occurring in applied sciences.
Coexistence and fluctuations phenomena with Davidson-like potentials in quadrupole–octupole deformed nuclei
Authors: Hammad M M , Mansour W H , El-Maghraby E M , Motaweh H A , Aly Ayman A 
Published: February 2021

Abstract
The energy spectra of three types of two-dimensional potentials (we will call them ‘Davidson-like potentials’ (DLPs)), characterized by four minima separated by barriers, are investigated. The predictions for spectra and wave functions are obtained by using the nine-point finite-difference method. For these potentials, with the existence of a single configuration, a transition of spectra, as a function of barrier height, is covered from tunneling splitting modes to fluctuations phenomena, with equal peaks wave functions, crossing to the spectra of purely anharmonic oscillator potentials (AOPs). A different type of phase transition occurs when two (or more) configurations coexist. With the change of the parameters, a transition of spectra is covered from coexistence phenomena of two distinct quantum tunneling modes to fluctuations phenomena, with unequal peaks wave functions, crossing to the spectra of purely AOPs. Using DLPs, a particular application of the coherent quadrupole–octupole model to describe energy bands with alternating parity of the nuclei 100Mo, 146,148Nd, 148,150Sm, 220Ra, 220,222Rn, and 220,222Th is presented. The global parametrization of the model for the selected nuclei is achieved.
Axiomatic tests for the Boltzmann distribution
Authors: Cerreia-Vioglio Simone , Maccheroni Fabio , Marinacci Massimo , Rustichini Aldo 
Published: February 2021

Abstract
The Boltzmann distribution family describes a single parameter (temperature) class of probability distributions over a state space; at any given temperature, the ratio of probabilities of two states depends exponentially on their difference in energy. Beyond physics, this distribution family is very popular in many important disciplines, under different names with different interpretations. Such widespread use in diverse fields suggests a common conceptual structure. We identify such a structure on the basis of few natural axioms that can be statistically tested. Our axiomatic characterization thus provides alternative empirical tests of the Boltzmannian modeling theories.
To the issue regarding the content of the future specialists training in the field of modern optics and photonics
Authors: Chulkova G M , Petrova E B 
Published: February 2021

Abstract
The article is a continuation of the authors’ works on the problem of achievements presentation of modern physics to future teachers and physics students. It deals with the issues related to the necessity explanation of the transition from electronic circuits to optical ones and technologies of optical circuits development. Moreover, the article shows the ways to motivate students to study physics and conduct experimental research. One such a way is to involve students to real scientific research. As a result, they can feel the importance of their contribution to the work of the group of researchers and appreciate the benefits of collective forms of work. The authors emphasize that nowadays professors and students have new opportunities associated with the access to new information and computer technologies, as well as greater the availability of rather complex physical equipment. The accessibility is connected with the organization of centers for common usage equipment, remote access to various databases of connected with results scientific research. All of the mentioned issues create favorable conditions for the further attempt to familiarize students with the problems of modern science.
Application of the clustering algorithm in an automated training system
Authors: Popov A A , Ovsyankin A K , Emomaliev M R , Satsuk M M 
Published: February 2021

Abstract
The development of information technologies provides a new, unique opportunity to conduct classes with the introduction of automated training systems for disciplines, which allows the student to choose the time and place for training, makes it possible to use new information technologies in training, and to a certain extent reduces training costs. The problem of improving the quality of the educational process in an educational institution is being solved because of the use of automated systems. This task is the main one in the activities of each educational institution. The development of a high-quality system will provide an increase in the student’s knowledge in the chosen field, and help to form an up-to-date curriculum for training. The purpose of this work is to create an automated training system using the clustering and content ranking algorithm, which can improve the quality of the student’s educational process.
Electronic poster as a way to implement educational activities
Authors: Pinevich E V , Kalinina I M , Abyshkina V V , Tugova Y A 
Published: February 2021

Abstract
The article is devoted to the description of the electronic educational poster created on one of the popular open platforms on the Internet and used as a way to implement educational activities in a distance or mixed (distance–face-to-face) format of teaching Russian to foreign students-masters of technical specialties. Work with the electronic educational poster is presented as an effective method of teaching, since the Russian language for foreign students at technical universities is a way of gaining knowledge on the future specialty, communication in Russian and getting to know Russian culture in general. Like any innovative technique, an electronic educational poster is not the main one that gives fundamental knowledge in the studied discipline, but an auxiliary tool that increases the motivation of students and increases their knowledge in the field of Russian vocabulary and grammar. The authors of the article describe the algorithm for creating an electronic educational poster, and also share practical recommendations for working with it. The article also presents the experiment conducted with master students of the faculty of pre-university training and 1st year students who studied Russian, the scientific style of speech and cultural linguistics using an electronic educational poster; examples of materials and tasks posted on the poster are given. At the end of the article, the results of the experiment are given and the prospects for the use of electronic posters in educational activities are outlined.
Innovative technology for assessing the quality of information security systems in the design of a modern educational environment
Authors: Bulgakov O M , Kadnova A M , Grebennikova N I , Meshcheryakov V A , Belyaev R V 
Published: February 2021

Abstract
The article describes an experimentally-based innovative technology for assessing the performance characteristic «Usability» of the information security system in the automated system of the digital educational environment. This characteristic consists of indicators: the structure of a typical operation, time index and probability rate. On the basis of the obtained results of the assessment of the listed indicators it is possible to choose an information security system for the designed digital educational environment.
Teaching EFL through culture and technologies
Authors: Arkhipova Maria V , Zhulina Elena V , Shutova Natalia V , Orlova Olga A , Medvedeva Elena Y 
Published: February 2021

Abstract
The article refers to the experience of introducing the Country Studies Course into University Baccalaureate curriculum for students majoring in studying English as a foreign language in Minin Nizhny Novgorod State Pedagogical University, Russia. The purpose of the present research is to describe the program of the academic discipline, its objectives, content modules and teaching methods. The course, viewed as a contribution to University curriculum development, proves its effectiveness, helping students understand the countries, people and traditional values, get rid of existing prejudices, and it can be one of the ways contributing to mutual understanding, tolerance, appreciation of history, and culture. Information and communications technology is used as an effective teaching tool, meeting the needs of the modern generation of students. The study is a source of guidance and practical advice for novice and experienced teachers as well as administration seeking to compare existing programs with the aim to introduce the best practice into University education.