bluuebunny/crossref_metadata_2025 huggingface dataset:
Determinanten für die Stressbelastung bei jungen Mädchen mit chronischen Kopfschmerzen
Authors: Bung Simone , Saile Helmut , Laessle Reinhold
Published: June 2022

Chronische Kopfschmerzen bei Kindern und Jugendlichen sind ein häufiges Krankheitsbild, bei dem Stressfaktoren eine bedeutsame Rolle spielen. Aus der empirischen Literatur ergibt sich, dass die Stressbelastung der Jugendlichen erhöht ist, die Jugendlichen aber gleichzeitig nur über sehr eingeschränkte Fertigkeiten zur Bewältigung von Stresssituationen verfügen.

In der vorliegenden Arbeit wurde in einer kontrollierten Querschnittsstudie überprüft, welche Unterschiede sich beim Vergleich von Mädchen mit chronischen Kopfschmerzen mit einer Kontrollgruppe bezüglich Stressbelastung und Stressbewältigung zeigen. Darüber hinaus wurden die psychopathologischen Merkmale Ängstlichkeit und Depressivität erhoben und ein biologischer Indikator für chronischen Stress (die Cortisol-Aufwachreaktion) gemessen.

Mit multiplen linearen Regressionsanalysen wurde geprüft, welche Variablen die erlebte Stressbelastung beeinflussen.

Es wurden insgesamt 148 Mädchen untersucht im Altersbereich zwischen 13 und 17 Jahren. Stressbelastung und Stressbewältigung wurden mit dem SSKJ 3–8 gemessen. Speichelproben zur Bestimmung von Cortisol wurden zu Hause nach dem Aufwachen gesammelt.

Die Ergebnisse belegen eine höhere Stressbelastung der Mädchen mit Kopfschmerzen auf körperlicher und psychischer Ebene und eine größere Empfindlichkeit für die Wahrnehmung einer Situation als stressbezogen. Die Stressbewältigungsstrategien waren signifikant ungünstiger. Spezifisch für die Mädchen mit Kopfschmerzen fand sich eine erhöhte Cortisol-Sekretion nach dem Aufwachen. Als bedeutsame Einflussfaktoren für eine hohe psychologische Stressbelastung erwiesen sich die destruktive Stressverarbeitung sowie ein hohes Ausmaß an Ängstlichkeit und Depressivität. Bisher vorliegende Daten zur stressbezogenen Entstehung und Aufrechterhaltung von Kopfschmerzen bei Jugendlichen konnten bestätigt werden. Die Ergebnisse der Regressionsanalysen sprechen dafür, in der therapeutischen Praxis ein besonderes Augenmerk auf die Einbeziehung von Angst und Depression zu richten.
Interdisziplinarität in der Diagnosefindung häufiger Knochenläsionen im klinischen Alltag
Authors: Hartmann Wolfgang , Vieth Volker , Streitbürger Arne , Hardes Jendrik
Published: June 2022

Einleitung Die interdisziplinäre Zusammenarbeit war und ist insbesondere in der Gegenwart – bedingt durch den enormen Wissensfortschritt in der Medizin – von herausragender
Bedeutung. Die Diagnostik und Therapie von benignen und malignen Knochentumoren stellt alle beteiligten Fachdisziplinen aufgrund der Seltenheit dieser Tumoren häufig vor Herausforderungen.
Das Ziel dieses Artikels ist es, die Bedeutung der Interdisziplinarität in der Diagnosefindung von Knochentumoren herauszuarbeiten.

Methoden Es handelt sich um eine Übersichtsarbeit zur Bedeutung der Interdisziplinarität bei der Diagnostik von Knochentumoren. Aufgrund der nur umschriebenen Literatur zu diesem
Thema veranschaulichen wir anhand von Fallbeispielen die Notwendigkeit der interdisziplinären Zusammenarbeit.

Ergebnisse und Diskussion Dieser Artikel verdeutlicht, dass eine interdisziplinäre klinisch-radiologische Betrachtung von „leave-me-alone lesions“ und eine
klinisch-radiologisch-pathologische Korrelation von biopsierten Knochentumoren erfolgen muss. Alle Befunde müssen im Rahmen einer gemeinsamen interdisziplinären Konferenz in ein
diagnostisches Gesamtbild eingefügt werden, sodass nicht selten die Diagnose am Ende interdisziplinär erarbeitet wird.

Schlussfolgerung Für den „Kliniker“ ist es unabdingbar zu wissen, dass die Diagnose eines Knochentumors oft nicht allein durch den Pathologen gestellt werden kann und zwingend der
interdisziplinären Zusammenarbeit bedarf.
Knowledge Levels, Attitudes, and Behaviors of Health Care Professionals regarding COVID-19 Vaccines
Authors: Uzer Fatih , Yesil Omer , Gokmen Yasin , Sayan Mehmet Reşit , Cengiz Mucahit
Published: June 2022

Background Shortly after the coronavirus disease 2019 (COVID-19) pandemic, vaccines were developed. Vaccination of the society in a short time may be the most important step in the fight against the pandemic. Health workers can be considered role models for society.

Aim We aimed to investigate the COVID-19 vaccination status of health care workers.

Methods The universe of our cross-sectional and descriptive study consisted of doctors, nurses, secretaries, interns, and other health care professionals. In the light of the literature, a questionnaire was prepared that questioned the attitudes and behaviors of the participants about vaccines. Face-to-face interviews were conducted during the visits. SPSS was used for statistical analysis.

Results A total of 806 volunteers, 51.4% (414) male and 48.6% (392) female, with a mean age of 32.7 ± 9.3 years, were included in the study. In total, 4.6% (37) of the participants in the study had not received any COVID-19 vaccine. Male participants were vaccinated statistically significantly more than female participants (p = 0.044). Of those vaccinated against COVID-19, 98.3% (774) had received at least two doses. Also, 26.9% (217) of health care workers had COVID-19 disease. The rate of those whose first-degree relatives had COVID-19 was 42.2% (340). A total of 87.3% (704) of health care workers reported that COVID-19 vaccines were safe. Also, 25.3% (204), 29.5% (238), and 35.0% (282) of the participants reported that state officials' vaccination in front of the media, social media news, and national media news, respectively, affected the decision to vaccinate.

Conclusion Although male health care workers have received more COVID-19 vaccines than female health care workers, vaccination rates of health care workers are at an acceptable level. Health workers comply with the calendar recommended by the ministry.
Approach to the Diagnosis of Hepatoid Adenocarcinoma, an Under-reported Entity: Case Series and Review of Literature
Authors: Chhabra Prerna , Sancheti Sankalp , Sali Akash Pramod , Somal Puneet Kaur , Sharma Aishwarya , Brar Rahat Singh , Gulia Ashish , Kapoor Rakesh
Published: June 2022

Hepatoid adenocarcinoma is a rare type of extra-hepatic adenocarcinoma which exhibits morphological, functional, and immunohistochemical features of hepatocellular carcinoma, hence correct diagnosis poses a challenge. The most frequent site of this tumor is stomach and rarely occurs in ovaries, lung, gallbladder, pancreas, uterus, and other sites. We present four cases of hepatoid adenocarcinoma of our hospital at rare sites like lungs and gallbladder along with literature review and a simplified approach to diagnosis. In absence of adequate immunohistochemistry or radiological findings often this entity is missed or misdiagnosed as metastatic hepatocellular carcinoma. We have analyzed these hepatoid adenocarcinoma cases in terms of various clinical, serological, histo-morphological, and immunohistochemical parameters, and propose a systematic approach to correctly diagnose this entity.
A neutrally buoyant particle captured by vortex in a lid-driven cavity with an internal obstacle
Authors: Zhang Jianghong , Sun Gang , Hu Junjie , Wu Jian , Xu Maosen
Published: June 2022

The flow in the square cavity with internal obstacles exists widely; thus, investigating the effect of the existence of the obstacles on the flow and the motion of the solid particles is important. To understand, predict, and control the motion of the solid particles, the motion of a neutrally buoyant circular particle in a lid-driven square cavity with an internal circular obstacle is studied with the lattice Boltzmann method, where the effects of the obstacle size, obstacle location, initial position of the circular particle, and Reynolds number are investigated. Under the effect of the obstacle, the flow and the motion of the particle are quite different. Especially, under some cases, no limit cycle is observed, and the particle is captured by the secondary vortex at the lower layer of the square cavity, which is insensitive to the initial position of the circular particle. The effect of the Reynolds number on the motion of the particle is significant, with the increase in the Reynolds number, and the motion of the particle is different obviously. At low Reynolds numbers, the motion of the particle is confined by the primary vortex, which moves along the limit cycle at the upper layer of the square cavity. With the increase in the Reynolds number, the effect of the inertia of the particle becomes stronger, and the particle moves from the primary vortex to the secondary vortex until it is captured by the secondary vortex. At relatively high Reynolds numbers, the primary vortex develops, and the particle is confined by the primary vortex again, forming another limit cycle.
The emergence of new varieties of English in North America
Authors: Kretzschmar William A.
Published: June 2022

The emergence of English varieties in North America follows the predictions of complexity science. The complex systems model does not predict the small number of dialects that most scholars assume to be there because of their perception of variation. Instead, complexity science predicts that we should be able to observe varieties at many levels of scale, from the overall scale of “American English” down to varieties found at the scale of different regions or different colonies, and down to varieties found at the scale of every locality. This way of thinking about varieties, not as separate grammars or lexical lists but instead as scalar entities, explains the evidence of variation in North America much better than we understood it before.
Enregisterment processes of American English in nineteenth-century U.S. newspapers
Authors: Paulsen Ingrid
Published: June 2022

The question of when and how American English emerged as a distinct variety of English has recently been addressed again within more general discussions of the emergence and evolution of new varieties of English (Schneider 2007; Kretzschmar 2014, 2015). I argue in this chapter that these discussions would benefit from a clear and consistent differentiation between the emergence of varieties as discourse constructs (‘discursive varieties’) and as distinct structural systems (‘structural varieties’). I propose using the theoretical framework of ‘enregisterment’ (Agha 2003, 2007) to investigate the discursive dimension and I show how enregisterment processes can be studied systematically by providing a case study of metadiscursive activities linking five linguistic forms to stereotypic indexical values in nineteenth-century U.S. newspaper articles.
Canadian English lexis and semantics
Authors: Dollinger Stefan
Published: June 2022

This paper introduces the use of a historical dictionary as a linguistic resource. This dictionary, the Dictionary of Canadianisms on Historical Principles, Second Edition (Dollinger & Fee 2017) affords a new real-time perspective on the Canadian vocabulary. As it is based on an empirical, cross-variational perspective, it instills a comparative perspective into the data. The dictionary’s genesis, benchmarks and entry structure will be explained, before the vocabulary of Canadian English is sketched in four key components: typology, semantic donor domains, compounding as a key word-formation pattern and regionalisms within Canada. This study is intended as an introduction to this open access resource (www.dchp.ca/dchp2) and a first step towards a more sophisticated analysis of lexis over time.
Ground-state and dynamical properties of a spin-S Heisenberg star
Authors: Li Jiaxiu , Wu Ning
Published: June 2022

We generalize the Heisenberg star consisting of a spin-1/2 central spin and a homogeneously coupled spin bath modeled by the XXX ring [Richter J and Voigt A 1994 J. Phys. A: Math. Gen.
27 1139-1149] to the case of arbitrary central-spin size S < N/2, where N is the number of bath spins. We describe how to block-diagonalize the model based on the Bethe ansatz solution of the XXX ring, with the dimension of each block Hamiltonian ≤ 2S + 1. We obtain all the eigenenergies and explicit expressions of the sub-ground states in each l-subspace with l being the total angular momentum of the bath. Both the eigenenergies and the sub-ground states have distinct structures depending whether S ≤ l or l < S. The absolute ground-state energy and the corresponding l as functions of the intrabath coupling are numerically calculated for N = 16 and S = 1, 2, ⋯ ,7 and their behaviors are quantitatively explained in the weak and strong intrabath coupling limits. We then study the dynamics of the antiferromagnetic order within an XXX bath prepared in the Néel state. Effects of the initial state of the central spin, the value of S, and the system-bath coupling strength on the staggered magnetization dynamics are investigated. By including a Zeeman term for the central spin and the anisotropy in the intrabath coupling, we also study the polarization dynamics of the central spin for a bath prepared in the spin coherent state. Under the resonant condition and at the isotropic point of the bath, the polarization dynamics for S > 1/2 exhibit collapse-revival behaviors with fine structures. However, the collapse-revival phenomena are found to be fragile with respect to the anisotropy of the intrabath coupling.
Impact of Al
x
Ga1−x
barrier thickness and Al composition on electrical properties of ferroelectric HfZrO/Al2O3/AlGaN/GaN MFSHEMTs
Authors: Li Yue , Liu Xingpeng , Sun Tangyou , Zhang Fabi , Fu Tao , Wang-yang Peihua , Li Haiou , Chen Yonghe
Published: June 2022

Ferroelectric (FE) HfZrO/Al2O3 gate stack AlGaN/GaN metal-FE-semiconductor heterostructure field-effect transistors (MFSHEMTs) with varying Al
x
Ga1−x
N barrier thickness and Al composition are investigated and compared by TCAD simulation with non-FE HfO2/Al2O3 gate stack metal–insulator–semiconductor heterostructure field-effect transistors (MISHEMTs). Results show that the decrease of the two-dimensional electron gas (2DEG) density with decreasing AlGaN barrier thickness is more effectively suppressed in MFSHEMTs than that in MISHEMTs due to the enhanced FE polarization switching efficiency. The electrical characteristics of MFSHEMTs, including transconductance, subthreshold swing, and on-state current, effectively improve with decreasing AlGaN thickness in MFSHEMTs. High Al composition in AlGaN barrier layers that are under 3-nm thickness plays a great role in enhancing the 2DEG density and FE polarization in MFSHEMTs, improving the transconductance and the on-state current. The subthreshold swing and threshold voltage can be reduced by decreasing the AlGaN thickness and Al composition in MFSHEMTs, affording favorable conditions for further enhancing the device.
Water adsorption performance of UiO-66 modified by MgCl2 for heat transformation applications
Authors: Liu Jia-Li , Fu Guo-Dong , Wu Ping , Liu Shang , Yang Jin-Guang , Zhang Shi-Ping , Wang Li , Xu Min , Huai Xiu-Lan
Published: June 2022

UiO-66 is a potential material for adsorption heat transformation (AHT) with high specific surface area, and excellent thermal and chemical stability. However, the low water adsorption capacity of UiO-66 in the low relative pressure range (0 < P/P
0 < 0.3) limits its application in AHT. We prepare the UiO-66 modified by MgCl2 through using the solvothermal method and impregnation method, and study their water vapor adsorption performances and heat storage capacities. Attributed to the extremely high saturated water uptake and excellent hydrophilicity of MgCl2, the water adsorption performance of UiO-66 is improved, although the introduction of MgCl2 reduces its specific surface area and pore volume. The water adsorption capacity at P/P
0 = 0.3 and the saturated water adsorption capacity of the UiO-66 (with MgCl2 content of 0.57 wt%) modified by the solvothermal method are 0.27 g/g and 0.57 g/g at 298 K, respectively, which are 68.8% and 32.6% higher than the counterparts of pure UiO-66, respectively. Comparing with pure UiO-66, the water adsorption capacity of the UiO-66 (with MgCl2 content of 1.02 wt%) modified by the impregnation method is increased by 56.3% and 14.0% at the same pressure, respectively. During 20 water adsorption/desorption cycles, the above two materials show high heat storage densities (∼ 1293 J/g and 1378 J/g). Therein, the UiO-66 modified by the solvothermal method exhibits the excellent cyclic stability. These results suggest that the introduction of an appropriate amount of MgCl2 makes UiO-66 more suitable for AHT applications.
UAV Landing Aid Hexapod Robot based on ArUco Marker and Sparse Optical Flow
Authors: Yue ZHU , Shuai HE , Xuechao DUAN , Ziqi XU
Published: June 2022

A UAV (Unmanned Aerial Vehicle) landing robot system based on a six-degree-of-freedom hexapod and computer vision with ArUco marker and sparse optical flow is implemented in this paper. By using binocular camera measuring the real-time position and orientation of UAV, a dynamic target tracking method based on ArUco marker and sparse optical flow is proposed. In this method, the ArUco marker is combined with sparse optical flow to improve the accuracy of target detection and the matching error of binocular stereo matching. The binocular vision system with ArUco marker is used to measure and calculate the relative coordinates of markers in the camera coordinate system. Then the UAV contour fitting is conducted in order to obtain the real-time position and orientation of this mobile target. The effectiveness of the novel UAV landing hexapod robot system based on ArUco marker combined with sparse optical flow is verified through the UAV capture experiment.
Research on Connector Assembly System and Control Strategy for Large-scale Panel
Authors: Fan Yang , Changming Hu , Zhanying Feng , Min Liu , Xumin Wang
Published: June 2022

There are technical requirements for the assembly of thousands of separate flange joints on the radar panel. The use of traditional manual assembly has problems such as high labor intensity, low assembly efficiency, and difficulty in uniform assembly quality. Therefore, in response to the above problems, combined with the requirements of high precision of joint assembly position and attitude, and intelligent management and control of the operation process, a set of joint component assembly system based on dual vision positioning, robot + ground rail + multi-axis module drive multi-gripper and electric batch accurate assembly is proposed. The system uses a dual-vision precise guidance control robot + ground rail as the main actuator, and an end effector composed of a multi-gripper assembly module and a lock. Using PLC as the main control center, equipped with robot, host computer, vision and other sub-systems, In this way, a large-scale, high-precision, and high-reliability joint assembly for military products is realized.
Extending the Force Balancing Method of Adjusting Kinematic Parameter to Spatial Mechanisms
Authors: He Ruyi , Borugadda Anil , Zhang Bing , Zhang Wenjun
Published: June 2022

Robotic mechanisms is one that the mechanism includes no less than one variable speed actuator. As for force balancing, which refers to mechanisms with a complete cancelation of the inertia-induced force on the ground (shaking force). A few strategies are accessible for reducing shaking force, including the counterweight (CW), add-of-spring (AOS), add-of-linkage (AOL), and adjusting kinematic parameter (AKP). AKP is only applicable to planar robotic mechanisms when it was developed. The primary goal of the present paper is to extend AKP approach to a spatial mechanism. Considering the complex kinematic characteristics of spatial mechanism, a simple spherical parallel robot (SPR) is used as the research tool. The equations for force balancing of the spherical robotic mechanism using AKP were derived. Simulation verification was performed by a reliable software called SPACAR available in the Matlab environment. The results demonstrated the effectiveness of the AKP method in eliminating the unbalanced force to spatial mechanisms. The main contribution is the provision of a new force balancing method to spatial mechanisms, which will enrich the field of balancing of spatial robotic mechanisms.
Symmetry Weight-sharing for Patch-based Stereo Matching
Authors: Yan Tingman , Yang Xilian , Zhao Qunfei
Published: June 2022

Neural networks are becoming more popular than traditional methods in stereo matching. The networks can be decomposed into four sub-modules: feature extraction / matching cost computation, cost aggregation, disparity computation / optimization, and disparity refinement. A typical design for the feature extraction networks is that the left and right branches share the same weights. However, the Siamese networks are weak at distinguishing neighboring patches because of the interference of geometric distortion on slanted surfaces. This paper proposes symmetry weight-sharing to improve the feature extraction networks. The geometry of feature extraction and patch comparison has been analyzed, which shows that symmetry weight-sharing can fulfill the geometry on slanted surfaces. A half-translation module is proposed to implement symmetry weight-sharing without additional computational costs. Experiments on the KITTI 2012 and KITTI 2015 datasets show that the symmetry weight-sharing networks have better performance than the weight-sharing networks.
Low-light Image Enhancement Algorithm Based on Exposure Prediction and Hybrid Feature Weighted Fusion Strategy
Authors: Hui Yanming , Wang Jue , Shi Ying , Li Bo
Published: June 2022

First, based on a given low-light image, moderately exposed and overexposed images are generated through the Exposure Image Prediction Model (EIPM).Then all three generate feature maps by a Feature Extraction Module (FEM),and then the feature maps of them are denoised. Subsequently, the feature map of the low-light image is fused with the feature maps of the two exposure rates images respectively. Finally, an adaptive weighted fusion method is used to obtain ultimate enhanced image. Experiments show that by comparing with the current SOTA algorithms,the proposed ELLIE algorithm, both in the detail feature retention and in color recovery have been significantly improved, and the subjective and objective evaluation indicators also have obvious advantages.
Review of state of computer vision technologies development in the world and Ukraine
Authors: Valko N V , Osadchyi V V
Published: June 2022

Computer Vision is a multidisciplinary field, a unit of artificial intelligence and machine learning. It includes the specialized methods and general learning algorithms use. More and more scientists are becoming interested in Computer Vision researching. Therefore, it is important to train future professionals in this area and develop special study programs. We reviewed the development of Computer Vision technologies in the world and in Ukraine, considered the challenges facing professionals and gave an example of Computer Vision project development.
Application of image processing programs in color analysis of wood photodegradation
Authors: Plata G J D , delos Santos R M
Published: June 2022

In general, polymer photodegradation is an important aspect of polymer science that is of great interest to chemistry, materials science, biology, and physics students who engage in this field of research. Wood consists of three main polymers, which makes it a good candidate for such photodegradation studies. Aside from structural changes based on chemical analysis, color change assessment can also be employed to check any extent of degradation on wood without the need for sophisticated analytical equipment. This study presents the application of two image processing programs in color analysis of wood photodegradation: ImageJ and Colormath library, which are Java-based and Python-based software, respectively. Images of unexposed and UV-exposed wood samples were taken using a smartphone as an affordable digital camera. RGB channel values from these images were analyzed and quantified by ImageJ software. These values were converted to the corresponding CIEL*a*b* parameters using the Colormath library to calculate the color change, ΔE. For the 3-hour exposed sample, ?E is equal to 4.29. This value indicates appreciable color change, according to the criteria from literature. Regardless of the exposure time, the wood samples become darker as indicated by the negative value in the change in lightness L*
Practice of applying functional approach to the design of digital learning aids
Authors: Bilousova L I , Gryzun L E , Lytvynova S H
Published: June 2022

In accordance with its aim, the paper highlights practical aspects and experience of the functional approach applying to the development of contemporary digital learning aids in the progress of project-driven activity of the pre-service IT specialists at their holistic vocational training. Theoretical framework of the work is made by holistic educational paradigm and functional approach to digital learning aids development. The specific examples of such an experience of the functional approach applying to the design of digital learning aids within project-based activity of the pre-service IT-specialists at their holistic vocational training: project activity on the design of (1) English digital tutorial for schoolchildren and (2) e-guide on the cryptography fundamentals for university students, are depicted in details. The analysis of such an activity is provided from the standpoint of the benefits of holistic and functional approaches. The prospects of following up research are covered.
ICT-based assessment of cognitive load in chemistry learning
Authors: Derkach T M
Published: June 2022

The article is devoted to studying and preventing an excessive increase in the cognitive load of university students studying chemistry using various electronic resources. The experiment involved 49 third-year students of the Faculty of Chemistry who studied organic chemistry. A homemade software was developed to measure the level of cognitive load using the secondary problem method. Cognitive load levels were studied depending on the types of used electronic resources. The studied resource types are texts of different levels of complexity, audio and visual materials in different combinations. The load values were measured for each respondent, expressed in relative quantitative units and averaged over the whole student group. In parallel, the preferred learning styles among the respondents were identified according to the Index of Learning Style of Felder-Soloman. A correlation was established between the preferred learning styles of students and the cognitive load they feel when working with electronic resources. The factors that affect an optimal set of educational resources were identified for student groups with various learning profiles. The results of factor analysis allowed the authors to assess the contribution of different learning styles in the formation of cognitive load in the use of different electronic resources. The techniques described in this article allow one to control cognitive load, predict and prevent its excessive increase.
Development of logical thinking of high school students through a problem-based approach to teaching mathematics
Authors: Lovianova I V , Yu Kaluhin R , Kovalenko D A , Rovenska O G , Krasnoshchok A V
Published: June 2022

This article considers the search for new methodological approaches to teaching high school students mathematics that will promote the development of their logical thinking. Based on the analysis conducted by the authors of the study identified an urgent need to develop the logical thinking of students in mathematics lessons through various methods of solving problems. The authors of the article set out to investigate the factors that will ensure the implementation of a problem-based approach to teaching mathematics. These factors include the choice of a certain type of mathematical problem; selection of a method for solving mathematical problems; compiling a system of problems of one type that require the selection of methods for solving them. The authors reveal the introduction of the problem approach as a method of developing students’ logical thinking in the article on the example of solving irrational equations with parameters. The authors of the study explain the value of problems with parameters by the fact that the process of solving them contributes to the formation of students’ research skills. In the study, the authors focused on the analytical method of solving problems with parameters. Structural analysis of problems allowed the authors to formulate the following didactic requirements for the system of mathematical problems such as compliance with the problems of the course content and the principle of gradual increase in complexity; the rational relationship between the logical and heuristic components of educational activities; the presence of ideological and technical complexity, etc. To confirm the effectiveness of the introduction of the problem-based approach to the educational process, as a method of developing students’ logical thinking, an experiment was conducted. The main objectives of the experiment were to identify the level of logical thinking of students; development and implementation in the educational process of a system of problems with parameters in the study of the topic “Irrational equations”, which contribute to the development of logical thinking of students; analysis of the results of the experiment. The obtained results and their statistical processing confirmed significant differences in the levels of development of logical thinking in the control and experimental groups, respectively. This proved the effectiveness of a problem-based approach to teaching mathematics and the development of logical thinking of students.
Mathematical competence and mathematical abilities: structural relations and development methodology
Authors: Semenets S P , Semenets L M , Andriichuk N M , Lutsyk O M
Published: June 2022

In the presented work, the concept of mathematical abilities is rational as both an essential internal characteristic of mathematical competence and an immanent attribute that prevails in its personal and psychological dimension. In view of the spatial Cartesian implementation the role and place of mathematical abilities in the three-dimensional structure of the internal manifestation of mathematical competence are substantiated. The semantic and system analysis of structural components of the studied phenomenon is made. It is established that complex correlations of four structural components of mathematical abilities (system-forming, coding-formalized, cognitive-generalizing, mnemonic-generalizing) can exist with three dimensions of the external manifestation of mathematical competence (semantic-theoretical, procedural-active, personal-psychological). It is introduced that the development of mathematical abilities is provided by updating the external dimensions of mathematical competence in educational and mathematical activities. The method of developing the mathematical abilities of students is presented according to the results of the implementation of this idea and the principle of developmental continuity. The basis of this technique is the developmental-problem method of teaching mathematics as a four-level problem structure which embodies the methods of mathematical and educational (educational-theoretical) modeling, the method of ascent from the abstract to the concrete, provides a reflection of the process and results of educational and mathematical activities. Due to the problem raised in the work the authors highlight the content and results of a pilot study on the development of mathematical abilities of future mathematics teachers (freshmen and graduates). The effectiveness of the created developmental methods of mathematical education was experimentally tested.
Personal e-Learning Environment of the Maths teacher’ online course as a means of improving ICT competency of a Mathematics teacher
Authors: Vlasenko K V , Chumak O O , Lovianova I V , Achkan V V , Sitak I V
Published: June 2022

The paper studies the issue of increasing the ICT competency of a Maths teacher. The study analyzes the concept of ICT competency of a Maths teacher and considers the possibilities of its formation in different countries. One of the ways to increase the ICT competency of a Maths teacher is to use the “Personal e-learning environment of the Maths teacher” online course. The authors describe the model of the developed course, which is based on the ADDIE model and takes into consideration the key activities of a teacher. The experiment, conducted among master’s students majoring in “Secondary education. Mathematics” showed the positive effects of the developed course on the level of their ICT competency. The redistribution of the percentage of the students towards normative and high levels of ICT competency formation was observed.
Computer addiction as a new way of personal self-realization of student youth
Authors: Yakovytska L S , Pomytkina L V , Synyshyna V M , Ichanska O M , Hordiienko K O
Published: June 2022

The article presents the results of an empirical study of computer addiction of student youth in the context of personal self-realization by parameters: motivation to succeed, volitional self-regulation, development of emotional intelligence. The aim of the article is to analyze the manifestations of computer addiction as a new way of personal self-realization, to empirically investigate the relationship of individual psychological factors of self-realization of personality by parameters: motivation to succeed, volitional self-regulation, development of emotional intelligence with subjective assessment of computer addiction by the student youth. Psychodiagnostic methods were used: test for Internet addiction of K. Young; Shostrom’s personal orientation (short form) in the modification of E. Jones and R. Crandall; N. Hall’s emotional intelligence test, a questionnaire to study the motivation to succeed of T. Ehlers; questionnaire “Study of volitional self-regulation” by A. Zverkov and E. Eidman. The study allowed to obtain significant correlations between computer dependence and the level of self-actualization, volitional self-regulation and its components, self-management of emotions as a component of emotional intelligence. Virtual space for the younger generation in modern conditions serves as a means of meeting those significant needs that are frustrated in real conditions. In particular, personal self-realization in student youth is transferred to cyberspace through new hobbies, acquaintances and attributions of their own “I”. Thus, computer addiction in this study was considered as a new way of personal self-realization of student youth, which is still treated mainly as a form of deviant behavior. Self-realization on the Internet for modern youth is a significant area of personal self-realization in general, which under favorable conditions complements self-realization in reality, and under adverse conditions replaces self-realization in reality. Taking into account these points will allow to build a system of psychological work with different levels of computer addiction of student youth in the context of their personal self-realization.
Preliminary evaluation of inverse scattering-based plasma-profilometry application to fusion plasmas
Authors: Mascali D. , Torrisi G. , Di Donato L. , Sorbello G. , Naselli E. , Pavone S. C. , Ceccuzzi S.
Published: June 2022

A new diagnostic method able to perform plasma profilometry is investigated in this work to retrieve the plasma electron density profile in front of the Ion Cyclotron Range of Frequencies (ICRF) antennas. As a reference scenario for our numerical study, the Divertor Tokamak Test (DTT [1]) ICRF antennas and plasma will be considered. Specifically, the profilometry needs to solve an inverse scattering problem, which is non-linear and ill-posed. In some recent papers [2, 3], plasma imaging profilometry in compact plasma reactors, such as the electron cyclotron ion sources (ECRIS), has been proposed and tested numerically by means of proof-of-concept examples. In particular, proper formulation of electromagnetic inverse scattering techniques have been proposed, requiring measurements of the reflection coefficient in presence of a metallic reflecting surface or, alternatively, both the reflection and transmission coefficients through two antennas facing one each other. In this paper, we would like to investigate this method also for large-size (scale-length) fusion reactors by addressing the profilometry of DTT-like plasma, assuming a very high-frequency probing regime (∼0.5 THz) for the accessibility of both O and X-modes in the DTT plasma (electron density up to 1020 m−3 and magnetic field up to 9 T). To this aim, we adopt COMSOL Wave Optics® module based on beam propagation method (or slowly varying envelope approximation) for simulating the wave propagation and to determine the probing frequencies. A proper formulation allowed to reconstruct a tiny scrape-off plasma layer, approximated as an isotropic medium, thanks to the high probing frequency.
Numerical analysis of radon behavior in radon-suppressed clean room environments
Authors: Di Marcello V. , Ianni A. , Panella G.
Published: June 2022

Radon-free clean rooms are essential for the production and
assembly of components adopted in low-background experiments. In
particular, long-lived radon decay products are often problematic
for rare events searches, such as low energy neutrino interactions,
direct dark matter detection, and neutrinoless double beta decay.
These isotopes can easily deposit onto surfaces exposed to radon,
leading to a residual background that can limit the sensitivity of
experiments. In order to mitigate this background source,
construction of detectors in radon-reduced environments is
essential. In this framework, design and building of
radon-suppressed clean rooms require a deep understanding of the
radon behavior and the different sources of contamination. In the
paper, computation fluid-dynamics (CFD) analyses of the
radon-suppressed clean rooms built for the DarkSide-50 experiment
are reported. The numerical model including the main radon
contributions, such as structural materials, equipment, and
operators activity, provides very promising results in a remarkable
agreement with available experimental data, confirming the validity
of the current modelling approach for future applications.
Sustainable irrigation technologies: a water-energy-food (WEF) nexus perspective towards achieving more crop per drop per joule per hectare
Authors: Taguta Cuthbert , Dirwai Tinashe Lindel , Senzanje Aidan , Sikka Alok , Mabhaudhi Tafadzwanashe
Published: June 2022

Sustainable agricultural intensification requires irrigation methods and strategies to minimize yield penalties while optimizing water, land and energy use efficiencies. We assessed, from a silo-based and integrated water-energy-food (WEF) nexus perspective, the performance of irrigation technologies in different agro-climatic regions. Secondary to this, we assessed the impact of adopting systematic approaches such as the WEF nexus on improving efficiency in irrigated agriculture through irrigation modernization. The evidence-based perspectives of silo-based performances individually considered the metrics of yield (Y), water use efficiency (WUE), and energy productivity (EP). The WEF nexus approach applied sustainability polygons to integrate the three metrics into a nexus index representing the holistic performance of the irrigation technologies. Silo-based performance in temperate regions suggests net gains for WUE (+1.10 kg m−3) and Y (+6.29 ton ha−1) when transitioning from furrow to sprinkler irrigation, with a net loss in EP (−3.82 ton MJ−1). There is potential for a net loss on EP (−3.33 ton MJ−1) when transitioning from furrow to drip system in temperate regions. The best performance of irrigation technologies in dry regions in water, energy and food silos was achieved by sprinkler, drip and furrow irrigation systems, respectively. Thus, appraising irrigation technologies from a silos perspective promotes individual silos, which renders an unsustainable picture of the performance of irrigation systems. The integrative WEF nexus approach successfully highlighted the trade-offs and synergies in the nexus of water, energy and food in irrigated agriculture. Drip irrigation led all irrigation technologies in WEF nexus performance in dry (21.44 unit2), tropical (23.98 unit2), and temperate regions (47.28 unit2). Overall, the irrigation modernization pathway to drip technology from either furrow or sprinkler systems improves irrigated agriculture’s WEF nexus performance in all three regions for more crop per drop per joule per hectare under climate change. This can promote inclusive and sustainable irrigation development within the planetary boundaries.
Development of solid phase extraction with carbon nanoonion-polyaniline composite sorbent followed by microextraction method for the extraction of pesticides residues before gas chromatography
Authors: Shokouhmandi Zahra , Shokrollahi Ardeshir
Published: June 2022

Organophosphate and triazole compounds are among the pesticides and fungicides that are classified as highly toxic materials because of their chronic and dangerous effects at low and moderate oral doses. Therefore, the measurement and extraction of small amounts of these compounds are of great importance for human and environmental health. In the present study, solid-phase extraction (SPE) was performed with carbon nano onion (CNO)-polyaniline (PANI) nanocomposite sorbent for the extraction of residual organic pesticides before gas chromatography (GC), so CNO was synthesized and covered with a layer of PANI for this purpose. The synthesized sorbent was analyzed and studied using different characterization methods. The prepared sorbent was used to extract pesticides from an aqueous medium. Then, for further preconcentration, the eluent of the SPE column was followed by a dispersive liquid-liquid microextraction (DLLME) method that had acceptable repeatability to the point that a wide linear range in 0.1–1000 μg l−1 (R2 > 0.99) was obtained for most analytes. Finally, pesticides determination in rainwater, apple juice, and cherry juice samples was conducted by the developed method.
Preparation and fluorescence properties of MgAl2O4: Tb3+ nanorod-like phosphors
Authors: Lu Yang , Wang Jing , He Lijie , Hao Chunlai , Wang Fudong , Zhang Jiaming
Published: June 2022

A series of MgAl2O4: x% Tb3+ (x = 1.0–6.0) phosphors was prepared by a hydrothermal-assisted light burning method. The crystal structure, morphology and fluorescence properties of the samples were investigated. The results indicated that when the the hydrothermal and light burning temperatures were determined to be 120 °C and 1100 °C, respectively, the crystallinity for Mg4Al2(OH)14 and NH4Al(OH)2CO3 biphasic precursors is the best, conducive to generating pure phase MgAl2O4 nanorod-like phosphors. The entry of Tb3+ into the MgAl2O4 lattice can cause lattice distortion, but the main structure of the spinel does not change. The main emission peaks for the series of phosphors are located in the green light region of 546 nm. The MgAl2O4: 4.0% Tb3+ phosphor has the highest fluorescence intensity and shows the best colour quality. Its CIE coordinates (x, y), CCT and colour purity are determined to be (0.3171, 0.5290), 5845 K and 53.50%, respectively. The series of MgAl2O4: Tb3+ phosphors exhibits typical cold green light emission and have good application prospects in solid-state display devices.
Poly(lactic acid) toughen by aromatic sulfonamide toward balanced rheology processing and mechanical properties
Authors: Chu Wenpeng , Yan Song , Cai Ziqing , Yang Shiwen , Hu Xinghui , Yin Xianze
Published: June 2022

The inherent brittleness of poly(lactic acid) (PLA) usually limits its application in the high ductile requirements sector. To address the above issue, n-ethyl-p-toluenesulfonamide (N-PTSA) as the toughening agent, was utilized to optimize the rheological and mechanical performance of the PLA matrix. The microstructure, thermal stability, rheological behavior, and mechanical properties of PLA/N-PTSA were systematically investigated. A rheological test showed that N-PTSA can reduce the melt processing viscosity of PLA matrix and the decreasing of processing viscosity strongly depended on the N-PTSA content rather than shear rate. Mechanical properties results confirmed that the 14.7% N-PTSA can improve the toughness of PLA/N-PTSA without deteriorating the tensile strength and Yong’s modulus. This reason was ascribed to the reduction of hydrogen bonds of PLA matrix caused by N-PTSA to accelerate the movement of PLA molecular chain meanwhile forming new hydrogen bond between PLA and N-PTSA. By adding N-PTSA, the thermal stability of PLA was decreased. With the synergistic effect of plasticizing and toughening N-PTSA, the rheology and mechanical properties of PLA had been effectively improved.
A robust statistical analysis of the role of hydropower on the system electricity price and price volatility
Authors: Owolabi Olukunle O , Lawson Kathryn , Sengupta Sanhita , Huang Yingsi , Wang Lan , Shen Chaopeng , Getmansky Sherman Mila , Sunter Deborah A
Published: June 2022

Hydroelectric power (hydropower) is unique in that it can function as both a conventional source of electricity and as backup storage (pumped hydroelectric storage and large reservoir storage) for providing energy in times of high demand on the grid (S. Rehman, L M Al-Hadhrami, and M M Alam), (2015 Renewable and Sustainable Energy Reviews, 44, 586–98). This study examines the impact of hydropower on system electricity price and price volatility in the region served by the New England Independent System Operator (ISONE) from 2014-2020 (ISONE, ISO New England Web Services API v1.1.” https://webservices.iso-ne.com/docs/v1.1/, 2021. Accessed: 2021-01-10). We perform a robust holistic analysis of the mean and quantile effects, as well as the marginal contributing effects of hydropower in the presence of solar and wind resources. First, the price data is adjusted for deterministic temporal trends, correcting for seasonal, weekend, and diurnal effects that may obscure actual representative trends in the data. Using multiple linear regression and quantile regression, we observe that hydropower contributes to a reduction in the system electricity price and price volatility. While hydropower has a weak impact on decreasing price and volatility at the mean, it has greater impact at extreme quantiles (>70th percentile). At these higher percentiles, we find that hydropower provides a stabilizing effect on price volatility in the presence of volatile resources such as wind. We conclude with a discussion of the observed relationship between hydropower and system electricity price and volatility.
An extension of a supercongruence of Long and Ramakrishna
Authors: Guo Victor , Liu Ji-Cai , Schlosser Michael
Published: June 2022

We prove two supercongruences for specific truncated hypergeometric series. These include a uniparametric extension of a supercongruence that was recently established by Long and Ramakrishna [Adv. Math. 290 (2016), pp. 773–808]. Our proofs involve special instances of various hypergeometric identities including Whipple’s transformation and the Karlsson–Minton summation.
Well-posedness of mean field games master equations involving non-separable local Hamiltonians
Authors: Ambrose David , Mészáros Alpár
Published: June 2022

In this paper we construct short time classical solutions to a class of master equations in the presence of non-degenerate individual noise arising in the theory of mean field games. The considered Hamiltonians are non-separable and local functions of the measure variable, therefore the equation is restricted to absolutely continuous measures whose densities lie in suitable Sobolev spaces. Our results hold for smooth enough Hamiltonians, without any additional structural conditions as convexity or monotonicity.