bluuebunny/crossref_metadata_2025 huggingface dataset:
Free energy surface of two-step nucleation
Authors: Eaton Dean , Saika-Voivod Ivan , Bowles Richard K. , Poole Peter H.
Published: June 2021

We test the theoretical free energy surface (FES) for two-step nucleation (TSN) proposed by Iwamatsu [J. Chem. Phys. 134, 164508 (2011)] by comparing the predictions of the theory to numerical results for the FES recently reported from Monte Carlo simulations of TSN in a simple lattice system [James et al., J. Chem. Phys. 150, 074501 (2019)]. No adjustable parameters are used to make this comparison. That is, all the parameters of the theory are evaluated directly for the model system, yielding a predicted FES, which we then compare to the FES obtained from simulations. We find that the theoretical FES successfully predicts the numerically evaluated FES over a range of thermodynamic conditions that spans distinct regimes of behavior associated with TSN. All the qualitative features of the FES are captured by the theory, and the quantitative comparison is also very good. Our results demonstrate that Iwamatsu’s extension of classical nucleation theory provides an excellent framework for understanding the thermodynamics of TSN.
Selective observation of transverse optical phonons of Au modes to evaluate free charge carrier parameters in
β
-Ga2O3 substrate and homoepitaxial film
Authors: Onuma Takeyoshi , Sasaki Kohei , Yamaguchi Tomohiro , Honda Tohru , Kuramata Akito , Yamakoshi Shigenobu , Higashiwaki Masataka
Published: June 2021

Polarized infrared reflectance spectra from β-Ga2O3 (001) unintentionally doped (undoped) and Sn-doped substrates were investigated. Spectra from an undoped homoepitaxial film grown on the Sn-doped substrate were also investigated. By setting the electric field vector of the incident light E parallel to the crystallographic b-axis in the s-polarized configuration, the spectra for pure transverse optical phonons of Au modes were well reproduced by the Drude–Lorentz model. Subsequently, the free-carrier concentrations and carrier mobilities were determined to be in reasonable agreement with those determined by Hall-effect measurements, and at the same time, the film thickness was determined for the homoepitaxial layer. The results ensure the validity of the simplified optical model analyses for any arbitrary surface orientations where the b-axis is parallel to the surface only if no birefringence effects are present by choosing as E//b in s-polarized configuration.
Photovoltaic-driven microbial protein production can use land and sunlight more efficiently than conventional crops
Authors: Leger Dorian , Matassa Silvio , Noor Elad , Shepon Alon , Milo Ron , Bar-Even Arren
Published: June 2021

Significance

The cultivation of microbial biomass, which is rich in proteins as well as other nutrients, can play a vital role in achieving food security while mitigating the negative environmental footprint of agriculture. Here, we analyze the efficiency associated with using solar energy for converting atmospheric CO
2
derived from direct air capture into microbial biomass that can feed humans and animals. We show that the production of microbial foods outperforms agricultural cultivation of staple crops in terms of caloric and protein yields per land area at all relevant solar irradiance levels. These results suggest that microbial foods could substantially contribute to feeding a growing population and can assist in allocating future limited land resources.
Dissecting and modeling photic and melanopsin effects to predict sleep disturbances induced by irregular light exposure in mice
Authors: Hubbard Jeffrey , Kobayashi Frisk Mio , Ruppert Elisabeth , Tsai Jessica W. , Fuchs Fanny , Robin-Choteau Ludivine , Husse Jana , Calvel Laurent , Eichele Gregor , Franken Paul , Bourgin Patrice
Published: June 2021

Significance

Light pervasively affects physiology and behavior, especially the sleep–wake cycle (SWc), which is generated by clock signaling in the suprachiasmatic nuclei (SCN). Light synchronizes this clock and additionally exerts direct (circadian-independent) acute effects on sleep. However, it has never been clarified whether longer photic exposure, as experienced daily, might exert long-term sustained direct light effects (SDLE). Recording sleep in mice lacking a functional clock and/or the retinal photopigment melanopsin, we uncovered that circadian-driven input and SDLE equally contribute to SWc. SDLE were primarily mediated through melanopsin, with half relayed through SCN, redefining the latter’s role. Modeling allowed SWc prediction under simulated jet lags, further demonstrating SDLE as an important mechanism to consider when managing health consequences of light exposure.
Polymorphic tandem DNA repeats activate the human telomerase reverse transcriptase gene
Authors: Xu Tao , Cheng De , Zhao Yuanjun , Zhang Jinglong , Zhu Xiaolu , Zhang Fan , Chen Gang , Wang Yang , Yan Xiufeng , Robertson Gavin P. , Gaddameedhi Shobhan , Lazarus Philip , Wang Shuwen , Zhu Jiyue
Published: June 2021

Significance

Repetitive DNA sequences are abundant in the human genome, and their high variabilities contribute to genetic diversity and disease susceptibility. Here, we report that an intronic variable number tandem repeat element, VNTR2-1, is critical for the transcription of the human telomerase reverse transcriptase (
hTERT
) gene in a cell-context–dependent manner. Removal of this element at its native genomic site in cancer cells resulted in telomere shortening, cellular senescence, and impaired tumor growth. VNTR2-1 length, consisting of 53 to 160 copies of 42-bp repeats, varies widely in human populations. hTERT alleles with short VNTR2-1 are underrepresented in African American centenarians, suggesting that hTERT regulation by VNTR2-1 plays a role in human aging and tumorigenesis.
Human intermediate progenitor diversity during cortical development
Authors: Pebworth Mark-Phillip , Ross Jayden , Andrews Madeline , Bhaduri Aparna , Kriegstein Arnold R.
Published: June 2021

Significance

Radial glia (RG) are primary neural stem cells of the cortex, and our current models of human corticogenesis are derived from investigations into the spatiotemporal, transcriptomic, and morphological diversity of human RG. However, it is the progeny of RG, neural intermediate progenitor cells (nIPCs), that directly generate most neurons. As such, nIPCs play an important role in corticogenesis, and yet little is known about human nIPCs. We identified three gaps in our current understanding: when and where human nIPCs appear, what transcriptional subtypes exist, and what their morphological features are. Our results present a more complete view of human nIPCs and serve as a basis for interpreting organoids and other in vitro models of human brain development, evolution, and disease.
Addiction to Golgi-resident PI4P synthesis in chromosome 1q21.3–amplified lung adenocarcinoma cells
Authors: Shi Lei , Tan Xiaochao , Liu Xin , Yu Jiang , Bota-Rabassedas Neus , Niu Yichi , Luo Jiayi , Xi Yuanxin , Zong Chenghang , Creighton Chad J. , Glenn Jeffrey S. , Wang Jing , Kurie Jonathan M.
Published: June 2021

Significance

Our findings identify a type of oncogene addiction process driven by a lipid that controls prosurvival effector protein secretion. The crosstalk between functionally redundant phosphatidylinositol (PI) 4-kinases maintains addiction and can be targeted with small molecule kinase inhibitors that might be applicable to a genetically defined subset of cancers for which there are no effective targeted therapies.
Mapping pollution exposure and chemistry during an extreme air quality event (the 2018 Kīlauea eruption) using a low-cost sensor network
Authors: Crawford Ben , Hagan David H. , Grossman Ilene , Cole Elizabeth , Holland Lacey , Heald Colette L. , Kroll Jesse H.
Published: June 2021

Significance

Poor air quality is a global public health issue, contributing to millions of premature deaths per year worldwide. Low-cost air quality sensors are a promising tool to improve monitoring capabilities. In this study, we built and deployed a low-cost sensor network for emergency response during an extreme air quality event, the 2018 Kīlauea Lower East Rift Zone eruption. This network was used to estimate fine-scale population exposures to multiple pollutants, to measure the chemical transformation of volcanic emissions, and to provide real-time observations as part of emergency management efforts.
Phage-encoded ten-eleven translocation dioxygenase (TET) is active in C5-cytosine hypermodification in DNA
Authors: Burke Evan J. , Rodda Samuel S. , Lund Sean R. , Sun Zhiyi , Zeroka Malcolm R. , O’Toole Katherine H. , Parker Mackenzie J. , Doshi Dharit S. , Guan Chudi , Lee Yan-Jiun , Dai Nan , Hough David M. , Shnider Daria A. , Corrêa Ivan R. , Weigele Peter R. , Saleh Lana
Published: June 2021

Significance

Chemical tailoring of canonical bases expands the functionality of DNA in the same manner that posttranscriptional and -translational modifications enhance functional diversity in RNA and proteins. We describe the activities of ten-eleven translocation dioxygenase (TET)-like iron(II)- and 2-oxo-glutarate–dependent 5mC dioxygenases that are encoded by several bacteriophages to enable hypermodification of C5-methyl cytosine bases in their DNA. Phage TETs act on methylation marks deposited within GpC sequences by functionally-associated cytosine 5-methyltransferases. The hydroxymethyl groups installed are further elaborated by tailoring enzymes, thereby decorating the phage DNA with diverse, complex modifications. These modifications are predicted to have protective roles against host defenses during viral infection.
Lipid droplets in the nervous system
Authors: Ralhan Isha , Chang Chi-Lun , Lippincott-Schwartz Jennifer , Ioannou Maria S.
Published: June 2021

Lipid droplets are dynamic intracellular lipid storage organelles that respond to the physiological state of cells. In addition to controlling cell metabolism, they play a protective role for many cellular stressors, including oxidative stress. Despite prior descriptions of lipid droplets appearing in the brain as early as a century ago, only recently has the role of lipid droplets in cells found in the brain begun to be understood. Lipid droplet functions have now been described for cells of the nervous system in the context of development, aging, and an increasing number of neuropathologies. Here, we review the basic mechanisms of lipid droplet formation, turnover, and function and discuss how these mechanisms enable lipid droplets to function in different cell types of the nervous system under healthy and pathological conditions.
Muscle ankyrin repeat protein 1 (MARP1) locks titin to the sarcomeric thin filament and is a passive force regulator
Authors: van der Pijl Robbert J. , van den Berg Marloes , van de Locht Martijn , Shen Shengyi , Bogaards Sylvia J.P. , Conijn Stefan , Langlais Paul , Hooijman Pleuni E. , Labeit Siegfried , Heunks Leo M.A. , Granzier Henk , Ottenheijm Coen A.C.
Published: June 2021

Muscle ankyrin repeat protein 1 (MARP1) is frequently up-regulated in stressed muscle, but its effect on skeletal muscle function is poorly understood. Here, we focused on its interaction with the titin–N2A element, found in titin’s molecular spring region. We show that MARP1 binds to F-actin, and that this interaction is stronger when MARP1 forms a complex with titin–N2A. Mechanics and super-resolution microscopy revealed that MARP1 “locks” titin–N2A to the sarcomeric thin filament, causing increased extension of titin’s elastic PEVK element and, importantly, increased passive force. In support of this mechanism, removal of thin filaments abolished the effect of MARP1 on passive force. The clinical relevance of this mechanism was established in diaphragm myofibers of mechanically ventilated rats and of critically ill patients. Thus, MARP1 regulates passive force by locking titin to the thin filament. We propose that in stressed muscle, this mechanism protects the sarcomere from mechanical damage.
United States medical preparedness for nuclear and radiological emergencies
Authors: DiCarlo Andrea L , Homer Mary J , Coleman C Norman
Published: June 2021

With the end of the Cold War in 1991, U.S. Government (USG) investments in radiation science and medical preparedness were phased out; however, the events of 11 September, which involved a terroristic attack on American soil, led to the re-establishment of funding for both radiation preparedness and development of approaches to address injuries. Similar activities have also been instituted worldwide, as the global threat of a radiological or nuclear incident continues to be a concern. Much of the USG’s efforts to plan for the unthinkable have centred on establishing clear lines of communication between agencies with responsibility for triage and medical response, and external stakeholders. There have also been strong connections made between those parts of the government that establish policies, fund research, oversee regulatory approval, and purchase and stockpile necessary medical supplies. Progress made in advancing preparedness has involved a number of subject matter meetings and tabletop exercises, publication of guidance documents, assessment of available resources, clear establishment of anticipated concepts of operation for multiple radiation and nuclear scenarios, and identification/mobilization of resources. From a scientific perspective, there were clear research gaps that needed to be addressed, which included the need to identify accurate biomarkers and design biodosimetry devices to triage large numbers of civilians, develop decorporation agents that are more amenable for mass casualty use, and advance candidate products to address injuries caused by radiation exposure and thereby improve survival. Central to all these activities was the development of several different animal constructs, since efficacy testing of these approaches requires extensive work in research models that accurately simulate what would be expected in humans. Recent experiences with COVID-19 have provided an opportunity to revisit aspects of radiation preparedness, and leverage those lessons learned to enhance readiness for a possible future radiation public health emergency.
Remediation of the uranium industry in the Czech Republic: regulation aspects and main technologies
Authors: Jurda Miroslav , Němec Miloslav
Published: June 2021

There is a long history of uranium mining and milling in what is now the Czech Republic, with the main exploitation beginning in the second half of the 19th century. The greatest expansion was during the Cold War, which was then reduced after political changes in eastern Europe in the 1990s. Thereafter, almost all uranium work was stopped, the mines and mills were closed, and plans for decommissioning and remediation of sites and facilities were initiated. The paper describes the application of the regulatory framework for the decommissioning and remediation of the uranium waste sites and facilities in the Czech Republic, illustrated by examples of deep and surface mining, in-situ leaching sites, and ore processing facilities. It builds on information provided as a case study for the Nuclear Energy Agency’s Expert Group on Legacy Management. Some practical experience and lessons learned are presented. The sharing of the lessons and experience is noted as an important mechanism for avoiding the creation of future legacies.
Theoretical study of novel B–C–O compounds with non-diamond isoelectronic
Authors: Liu Chao , Ying Pan
Published: June 2021

Two novel non-isoelectronic with diamond (non-IED) B–C–O phases (tI16-B8C6O2 and mP16-B8C5O3) have been unmasked. The research of the phonon scattering spectra and the independent elastic constants under ambient pressure (AP) and high pressure (HP) proves the stability of these non-IED B–C–O phases. Respective to the common compounds, the research of the formation enthalpies and the relationship with pressure of all non-IED B–C–O phases suggests that HP technology performed in the diamond anvil cell (DAC) or large volume press (LVP) is an important technology for synthesis. Both tI16-B8C6O2 and tI12-B6C4O2 possess electrical conductivity. mP16-B8C5O3 is a small bandgap semiconductor with a 0.530 eV gap. For aP13-B6C2O5, mC20-B2CO2 and tI18-B4CO4 are all large gap semiconductors with gaps of 5.643 eV, 6.113 eV, and 7.105 eV, respectively. The study on the relationship between band gap values and pressure of these six non-IED B–C–O phases states that tI16-B8C6O2 and tI12-B6C4O2 maintain electrical conductivity, mC20-B2CO2 and tI18-B4CO4 have good bandgap stability and are less affected by pressure. The stress-strain simulation reveals that the max strain and stress of 0.4 GPa and 141.9 GPa respectively, can be sustained by tI16-B8C6O2. Studies on their mechanical properties shows that they all possess elasticity moduli and hard character. And pressure has an obvious effect on their mechanical properties, therein toughness of tI12-B6C4O2, aP13-B6C2O5, mC20-B2CO2 and tI18-B4CO4 all increases, and hardness of mP16-B8C5O3 continue to strengthen during the compression. With abundant hardness characteristics and tunable band gaps, extensive attention will be focused on the scientific research of non-IED B–C–O compounds.
Tunable optomechanically induced transparency and fast-slow light in a loop-coupled optomechanical system*
Authors: Liao Qinghong , Wang Xiaoqian , He Gaoqian , Zhou Liangtao
Published: June 2021

We theoretically explore the tunability of optomechanically induced transparency (OMIT) phenomenon and fast–slow light effect in a loop-coupled hybrid optomechanical system in which two optical modes are coupled to a common mechanical mode. In the probe output spectrum, we find that the interference phenomena OMIT caused by the optomechanical interactions and the normal mode splitting (NMS) induced by the strong tunnel coupling between the cavities can be observed. We further observe that the tunnel interaction will affect the distance and the heights of the sideband absorption peaks. The results also show that the switch from absorption to amplification can be realized by tuning the driving strength because of the existence of stability condition. Except from modulating the tunnel interaction, the conversion between slow light and fast light also can be achieved by adjusting the optomechanical interaction in the output field. This study may provide a potential application in the fields of high precision measurement and quantum information processing.
Distributed Ensemble based Deep Learning architecture for Intrusion Detection against Cyber attacks
Authors: Kavitha M , Elamukhil K , Ajeeth R , Ashwin R , Balasubramaniam V
Published: June 2021

The increasing scale and importance of web contact around the Internet has increased the need for improved cyber security defence against cyber attacks. On modelling the machine learning based intrusion detection system, features of the attacks helps to discover, determine and identify unauthorized behaviour. Behaviour modelling has been used as training model to detect the evolving attacks to the servers or learning model has been constructed to build a training model to identify the intrusion in the network on basis of signature of the attacks. However machine learning model fails in handling attacks propagating on the applications with large scale or large dimensional data which further leads to high false alarm rate. In order to tackle those issues, a new distributed ensemble based deep learning architecture has been employed using Convolution Neural Network, Recurrent Neural Network and Multilayer Perceptron towards intrusion detection on cyber attacks on the web servers. Convolution Neural Network, Recurrent Neural Network and Multilayer Perceptron has been modelled as training model to detect the intrusion, trained model will generate best model which acts as classifier or prediction model for cyber attacks. The particular model will be employed further to detect the intrusion propagating in the web server. The proposed ensemble based deep learning architecture is compared to state-of-the-art approaches on performance measures such as precision, recall, and f measure on true positive, false positive, true negative, and false negative computations using the KDD CUP 99 dataset.
Numerical approach for bifurcation and orbital stability analysis of periodic motions of a 2-DOF autonomous Hamiltonian system
Authors: Sukhov E
Published: June 2021

In Spaceflight Dynamics it is often necessary to obtain periodic motions of conservative mechanical systems and analyze their stability and bifurcation. These conservative systems can be described using Hamiltonian equations. We consider bifurcation and orbital stability problem for periodic motions of a 2-DOF autonomous Hamiltonian system. Since it is not possible to obtain analytical solutions to the aforementioned problem for all admissible values of its parameters a two-step numerical approach is proposed. On the first step the so-called base solutions are obtained analytically for particular values of problem’s parameters. The base solutions are then continued to the borders of their existence domains using a numerical algorithm. In course of computation bifurcation points are identified and orbital stability is studied. On the second step new base solutions are identified in the neighborhood of bifurcation points and the continuation process is repeated. Finally, orbital stability and bifurcation diagrams of the resulting families of periodic motions are constructed. Poincare sections are also computed in the neighborhoods of bifurcation points to verify the results. To illustrate this approach, we computed the bifurcation and orbital stability diagrams for families of short-periodic motions originating from Regular precessions of a dynamically-symmetric satellite.
Investigation of the dynamic behavior of CFRP with an embedded smart layer based on fiber-optic sensors
Authors: Tikhonova A , Anoshkin A , Baranov M , Nikiforov A , Sajenkov N , Pisarev P
Published: June 2021

Currently, special interest arises in the use of various systems for monitoring the state of structures during operation. Structures during operation, as a rule, experience dynamic loads. As a result, the monitoring system must correctly and accurately record this response. Most modern monitoring systems use fiber-optic sensors. Embedding fiber optic sensors directly into the structure of composite structures is a difficult task due to the fragility of the fiber. The team of authors has developed a prototype of the Smart-layer, which allows for safe implementation into structures made of carbon fibre reinforced polymer. However, the issue of decrypting the data obtained from the Smart layer is an urgent and laborious task. The paper presents the results of studies on the registration and interpretation of the dynamic response obtained from the Smart-layer embedded in carbon fibre reinforced polymer specimens under dynamic loading of the specimens. The results of field experiments on dynamic loading of samples were compared with model values. In the course of the study, good agreement was found between the model and experimental results.
Technique of considering the material anisotropy in topology optimization of short fibers composite structures
Authors: Kurkin E I , Kishov E A , Lukyanov O E , Espinosa Barcenas O U
Published: June 2021

The use of composite materials in the aerospace industry has been increasing in the past 20 years. The application of short fiber reinforced composite as materials for aerospace components can solve the delamination problem by substituting the laminates, reduce the weight and the cost of the component. The design of short fiber reinforced composite structures requires obtaining the optimal structure geometry which is a function of the injection molding process. The novelty of this work is the development of a topology optimization algorithm that considers the material anisotropy by simulating the injection molding process at intermediate steps of topology optimization on a reduced mesh of the design area. It is shown that the consideration of the material anisotropy within topology optimization leads to a susceptible change in the topology of the structure and made it possible to increase the stiffness of the aerospace bracket molded from short fiber reinforced polymers.
Marketing positioning when choosing strategic alternatives for the aircraft manufacturer product offer development
Authors: Kalugina G A
Published: June 2021

Marketing positioning of the company’s products is an integral part of strategic planning. Many theoretical and scientific works are devoted to positioning issues, but the specific aspects of marketing positioning of knowledge-intensive and high-tech products of aviation-industrial enterprises are not reflected anywhere. The purpose of this study is to reveal specific issues of marketing positioning of civil aircraft. In the study, the methods of a systematic approach, comparative analysis, segmentation and strategic marketing analysis were used, aimed to develop the theory of marketing positioning in terms of industry marketing. Within the framework of the study, the following results were obtained: a critical analysis of the positioning methods supported by examples from the world practice of the of aircraft manufacturers market activity was given, the most important positioning criteria reflecting the specifics of aircraft were identified and classified. According to the results of the study, it is concluded that it is necessary to adapt the methodological approaches of marketing positioning to manage the product offer development in the field of civil aircraft manufacturing.
Parametric investigations of strength of a composite panel after impact damage
Authors: Levchenkov M
Published: June 2021

Results of parametrical investigations of residual strength and buckling of damaged composite panels of civil aircrafts were considered. The investigations were performed on the base of the semi-empirical method developed by the author. The algorithm allows users to carry out the analysis of parameters of stress-strain state and to assess a general buckling behavior of composite panels in the automatic mode. The calculations were performed by using the special parametrical finite element models of composite panels that are typical for current civil aircrafts. The special models of panels consisted of composite laminated skin and different types of stiffeners have zones with reduced stiffness characteristics. The relationship between level of reducing mechanical characteristics of “damaged” zones and residual strength and buckling margins of the panels was determined.
Analysis of stability and bearing capacity of reinforced panels made of composite materials under shear
Authors: Mitrofanov O V , Osman M
Published: June 2021

When performing stress verification analysis of wing spar supported composite walls it is essential to estimate local stability of smooth wall and general stability of orthotropic panel under shear forces. Almost square fragment of spar wall supported with ribs (between two ribs) is examined in this paper. In order to estimate general stability and load-bearing capacity of orthotropic panel geometrically nonlinear problem is examined. When examining linear problem compact expression for critical shear flow definition is explicitly written in order to estimate general stability with ultimate loading. When examining nonlinear problem a system of two equations in deflection amplitude is obtained. Besides nonlinear problem of smooth wall (skin) local stability and postbuckling state estimation with possible geometrically nonlinear behavior is examined. Analytical solution of orthotropic rectangular panel with shear geometrically nonlinear problem is obtained. Based on method of design by postbuckling state with critical shear stress provided with buckling a method of skin thickness definition is suggested. In order to apply obtained solutions to design activities method of orthotropic panels design by stability and postbuckling state with corresponding load level is shown.
Numerical simulation of the effect of aircraft engines impact on the nuclear power plant containment
Authors: Ostrik A , Kim V
Published: June 2021

A new version of the governing equations for concrete is proposed. A numerical algorithm for solving the governing equations proposed has been developed. The developed algorithm is implemented as part of numerical 3D-code for the finite-size particle in cell method. Using the code the simulation of an airliner engine impact on the concrete containment was performed. It was obtained that engines with the speed of 100 m/s significantly damage the containment structure, but without full penetration (the engines stop right inside the protective shield). Nonetheless the total collapse of the central part of spherical dome onto the inner metal shell of the containment is probable when the engine impacts in downward direction.
Development of a methodology for eliminating failures of an FDM 3D printer using a “failure tree” and FMEA analysis
Authors: Zagidullin R , Antipov D , Dmitriev A , Zezin N
Published: June 2021

The article presents a functional structural analysis of the design and software of an FDM 3D printer. On the basis of functional and structural analysis, a “failure tree” of the design of a 3D printer was built. An FMEA analysis was carried out to identify the reasons for the design failures of the 3D printer and develop recommendations for their elimination. The result of the FMEA analysis was the development of a method for eliminating design failures in FDM 3D printers.
Ways to ensure lightning resistance of aviation carbon fiber polymer composite structures containing adhesive compounds
Authors: Salamatin V , Nasonov F
Published: June 2021

This work advances solutions to the problem of insufficient electrical conductivity of adhesive material, the adhesive layer, and, ultimately, the entire adhesive connection. Sufficient electrical conductivity is necessary to ensure the survivability of composite structures under lightning strike conditions. Along the way, solutions to the problem of unhindered flow of static electricity charges which can occur when aircraft not in flight and has catastrophic consequences when interaction occurs in the presence of aviation fuel is proffered.
Design of Wine Grape Mobile Terminal Scheduling Platform Architecture Based on IOT
Authors: Hou Tianlong , Zhang Tao , Huang Haoran
Published: June 2021

At present, China is in the initial stage of the modernization of agriculture 4.0. How to use science and technology to improve the combination of agricultural machinery and agronomy, speeding up the construction of agricultural information technology is the core issue that agricultural production enterprises focus on at the present stage. Therefore, on the basis of analyzing the current situation of agricultural machinery operation in wine grape producing areas, this paper sorted out and studied the literature from three aspects: intelligent scheduling algorithm and intelligent scheduling platform of agricultural machinery equipment and the application of Internet of Things technology in scheduling platform, putting forward a kind of wine grape farm machinery equipment based on IOT moving with intelligent dispatching platform architecture design.
Misconceptions or mental models
Authors: Sands David
Published: June 2021

This paper presents a detailed study of inconsistent thinking by entry-level students on a troublesome question on the Force Concept Inventory. Two cohorts of students separated by three years were asked a series of questions after completing the Force Concept Inventory. The questions were aimed at eliciting their background knowledge of Newton’s laws of motion along with their approach to question 26. For example, were they guessing, eliminating some impossibilities, reasoning the answer, etc. There was no common or even predominant approach and considerable evidence of inconsistent thinking. The results are discussed in the light of recent literature on the nature of thinking and in particular the debate over logical reasoning versus reasoning by mental models. It is argued that the mental-models perspective explains many aspects of the data and moreover is more conducive to teaching approaches than the misconceptions perspective.
Exploring secondary school students’ understanding of basic phenomena relating to wave optics
Authors: Cvenić Karolina Matejak , Ivanjek Lana , Planinić Maja , SušAc Ana , Jeličić Katarina , Hopf Martin , Srnka Christian
Published: June 2021

Interference, diffraction, and polarisation of light are the basic phenomena of wave optics. According to the findings of previous studies on wave optics, these phenomena are the source of many students’ conceptual difficulties. The goal of the present study was to qualitatively investigate and compare Croatian and Austrian secondary school students’ understanding of the main concepts and phenomena of wave optics as a first step that will serve as a preparation for a large-scale study on secondary school students understanding of wave optics. Here we present the preliminary results of six semi-structured demonstration interviews conducted in Croatia and Austria with secondary school students (age 18-19), after regular school instruction on wave optics.
Phase and group velocity: a research-based educational activity driven by students on the topic on waves
Authors: Buongiorno Daniele , Michelini Marisa , Faletič Sergej
Published: June 2021

To create an opportunity for students to re-elaborate their knowledge and offering them a working experience, 145 16-17 years old students from 6 classes from a Scientific Lyceum were involved in a research activity with responsibility in specific tasks involving conceptual learning of pulses and mechanical waves. Experiments by means of classical apparatus and mobile APPs were planned and performed by students themselves aiming at individuating the best way to prepare educational materials for peers. In this framework three different educational proposals were proposed to three different groups of students allowing them to point out weaknesses and strengths of the various approaches. The educational path aimed at clarifying the difference between phase and group velocity.
Project VLAB-FIS: a novel approach to engage students on experimental work in Physics
Authors: Carvalho P Simeâo , Machado N A , Araujo P P
Published: June 2021

Experimental work is very useful for motivating high school students towards science, leverage learning and also for developing procedural skills. Teachers usually provide their students with protocols of the experiments and expect to obtain good results from this practice, but students must be prepared before going to the lab in order to successfully accomplish the experimental work. The project VLAB-FIS is based on introductory videos that give a holistic view of the experimental works, facilitating a prior understanding of the experiments and their corresponding conceptual goals. The approach is complemented by video recordings of the experiments and computational simulations, for an inclusive participation of all students regardless of reading or physical disabilities. The project was presented to physics teachers in a workshop to better understand the feasibility of the project in Portuguese secondary schools from the teachers’ viewpoint. Teachers’ feedback shows that they consider the project useful as support for the preparation of laboratory classes.
Field lines in art and physics
Authors: Stonawski’ Tamás , Fülöp Csilla
Published: June 2021

The physical space surrounding us is not empty, it is filled by objects and fields. Macroscopic objects are visible, but fields can only be detected with sensitive instruments rather than the naked eye. Physicists introduced visual clues (field lines, trajectories, streamlines, equipotential surfaces) based on helpful mathematical concepts to characterize (the mostly invisible) physical fields. These illustrations are used in high school-level physics, but – due to their abstract nature – are not easily understood by students. Most of the confusion is caused by students mistaking the plotted auxiliary concepts for physical reality. We can help their understanding by drawing parallels between the visual representation of fields and the technical methods used by a painter to express the subject.
Beauty and physics — Physics projects based on modern aesthetic and medical treatments
Authors: Nagy Anett
Published: June 2021

As a natural science, physics seeks to answer questions that arise in the world around us. One of the areas of motivation is to show students that a number of devices and treatments used in the beauty industry or for staying healthy apply the laws and phenomena of physics. Examining the physical background of various, modern treatments can be used to raise simple and complicated issues in physics and also provides us the opportunity to carry out qualitative or quantitative experiments. We believe that these projects assist students in a better understanding of physics and also encourage teachers to make the subject more interesting.
Development of inquiry skills at upper secondary level
Authors: Ješková Zuzana , Jurková Veronika , Lukáč Stanislav , Ľubomír Šnajder , Guniš Ján
Published: June 2021

Development of inquiry skills is still in the main focus of science educators in Slovakia. Large effort has been recently put into the implementation of inquiry-based science education. In this research, the current level of development of selected inquiry skills has been monitored and analysed. For this purpose, a multiple-choice test of selected inquiry skills was designed. The tested skills involve formulating hypothesis, designing experiment, transforming results into tables and graphs, determining relationships between variables based on tables and graphs and identifying possible sources of errors. The test was implemented across several thousands of upper secondary school students. The inquiry skills´ test results revealed significant lack of their development. The paper describes the test design as well as it analyses and interpret the test results.
Effect of motion simulation programs in teaching force concept1
Authors: Radnai T , Juhász T Tóthné , Juhász A , Jenei P
Published: June 2021

The most important concept in dynamics is force. Teaching forces in secondary schools has many difficulties, due to the fact that when students start learning dynamics, they have already developed a force concept based on their everyday experiences. This concept is usually simplified and often confused with impulse. However, the concept taught on physics lessons, is a much more complex, based on a vectorial quantity, with a time-dependent direction and magnitude. This confusion of concepts can be largely eliminated by the visualization of force vectors during the motion of an object. This opportunity is available in motion-simulation software, which work as a digital sandbox, allowing users to create their own scenes and display force vectors during the simulations. Connecting kinematics by motion visualization and dynamics by force visualization is a powerful tool that helps students to develop deeper understanding in mechanics. In our educational research, we investigated the positive effect of using such a program. With the participation of 700 students, divided into experimental and reference groups, we measured their development in understanding mechanics. The results proved that students who used the simulation program reach a better functional understanding of the concept of force than those being in the reference group.
How high schools teach quantum physics – a cross-national analysis of curricula in secondary education
Authors: Stadermann H K E , Berg E van den , Goedhart M J
Published: June 2021

Quantum physics (QP) changed our worldview, it brought us modern electronic devices, and its almost mythical image fascinates. Although QP is relatively new in secondary education, it is now part of the national curricula of many countries. To understand the current state of QP content in high schools, we scrutinised upper secondary school physics curriculum documents in 15 countries. In these countries, we identified a similar core curriculum of QP which contains the following seven main categories: discrete atomic energy levels, interactions between light and matter, wave-particle duality, de Broglie wavelength, technical applications, Heisenberg’s uncertainty principle, and the probabilistic nature of QP. We also found differences in the focus of the listed topics of individual countries, which indicate different views on teaching QP. The thematic focus of QP items is related to the underlying goal of science education and to the way students’ knowledge is tested. This overview shows which QP content is generally feasible at a secondary level and which pedagogical perspectives are possible. Therefore this study might lead to reflections on existing QP curricula, and inspire countries that do not have QP in their curriculum yet.
Using a simple scintillator kit to experience gamma ray detection
Authors: Santi Lorenzo , Gervasio Mario , Michelini Marisa , Faletič Sergej
Published: June 2021

A simple scintillator kit developed by Ian Bearden [1] was used to prepare a learning experience on gamma ray detection for secondary students. The goal is to offer an opportunity to collect gamma spectra, analyse data and understand how coincidence measurements are useful in space physics and in many other applications.
Physics and Mathematics university students’ ideas about computer simulations
Authors: Barelli Eleonora
Published: June 2021

In an increasingly complex world, the science of complex systems is well-positioned to provide epistemological lenses and methodological tools to analyse the reality. Among the tools developed, computer simulations have a crucial role, but the ways in which they are conceptualized by graduate and undergraduate students have not been extensively explored. Framed within a wider research about the educational role of simulations of complex systems, the goal of this work is to provide insights into the understanding about simulations of university Physics and Mathematics students. For this purpose, a study has been designed with a group of bachelor and master students within a course of Physics Teaching. The object of this paper is to present the results of the data analysis of the preliminary questionnaires, where 27 students were asked to express their ideas about simulations. The bottom-up process of qualitative analysis has allowed to point out, and organize in categories, different ways in which simulations are conceptualized by the students, in terms of: i) scope for which simulations are used, ii) their relationship with experiments and models, and iii) the examples of simulations they refer to.
Should the third Newton’s law be the first one? A TLS on dynamics for upper secondary school
Authors: Sagastibeltza Mikel , Sarriugarte Paulo , Zuza Kristina , Guisasola Jenaro
Published: June 2021

In this paper we are presenting the design and evaluation process of a Teaching Learning Sequence (TLS) following Design Based Research (DBR) methodology. The TLS was designed for the upper secondary school students on particle dynamics. In this work, we present the very first results of the process. The iterative DBR methodology is presented giving evidences about design decision and tools for evaluation. This TLS was implemented in a post compulsory high school in the Basque Country. The results obtained in the first implementation show that there are improvements in the learning achieved by students in comparison with a control group. The strengths and weaknesses of the TLS will be analyzed for future redesign phase into DBR phases.
Contemporary Experiments and New Devices in Physics Classrooms
Authors: Milner-Bolotin Marina , Milner Valery , Tasnádi Anikó Márta , Weck Hannah Theresa , Groma István , Ispánovity Péter Dusán
Published: June 2021

Classroom demonstrations and experiments have played an important role in physics teaching for centuries. They are important for deepening student knowledge and helping students gain meaningful understanding of physical principles. In addition, experiments can motivate stu-dents and facilitate their active engagement with abstract concepts. In this paper, we present four novel physics experiments and demonstrations that address the pedagogical needs of the 21st century physics teaching. These experiments: (a) employ modern technologies that bring physical phenomena closer to the students; (b) showcase teaching methods that reduce barriers for the students with special needs; and (c) suggest an innovative thermodynamics demonstration related to environmental issues and green energy. The descriptions of the experiments, their applications to secondary school teaching as well as to college-level physics education are thoroughly discussed.
Energy supply only with renewables? Why does Hungary need to extend its nuclear power capacity?
Authors: Gärtner Istvan
Published: June 2021

This presentation showed the results of my study which was connected to a survey in ELTE University in Budapest 8 years ago. The results of my research prompted me to prepare a compilation for high school students. In this work I tried to acquaint them from one side the energetics in general and from the other side the areas of use of the different energy sources, highlighting the natural conditions and the resulting opportunities for the energy production of Hungary. My aim was that the students could get a professionally authentic and understandable information in these topics. According to this I hope they could realize the importance of the energy supply in their future.
The influence of high school teachers on the representations of the role of an “exemplary teacher” according to future physics teachers
Authors: Nardi Roberto , Reis Belíssimo Jéssica dos , Parma Fabiano Willian
Published: June 2021

We highlight here part of a longitudinal study, which sought to follow a group of future physics teachers and explain how research has been introduced in or affected their initial training. We seek to analyse their representations of the role of an ‘exemplary teacher’, considering that some of the graduates affirmed to have chosen a career as a teacher because of the influence of their high school teachers. The data were collected through questionnaires administered at the beginning of the study to students enrolled in the teacher education programme and treated by Discourse Analysis. We compare students’ representations with five dimensions that characterize an “exemplary teacher”. The results show that the characteristics of their high school teachers appear in the discourse of the students when they refer to an “exemplary teacher”.
An instructional method, based on POE (Predict-Observe-Explain), for teaching two basic wave properties and the wave nature of light
Authors: Gkiolmas Aristotelis , Stoumpa Artemisia , Lazos Panagiotis , Skordoulis Constantine , Chalkidis Anthimos , Michalopoulos Vassilis , Balwit John
Published: June 2021

This work presents a series of lessons containing didactic experiments, as well as the related educational research. The series concerns the instruction of prospective primary school teachers who possess a weak Physics background. The main topics of instruction are: basic concepts of wave behavior (mainly interference and diffraction), as well as the wave properties of light. This instruction is based on POE (Predict-Observe-Explain) techniques. It constitutes the basis of a broader effort in the making, which aims at teaching future teachers about wave properties and wave-particle duality. The benefits of teaching such notions of waves to teachers are examined, the learners’ previous knowledge and their views are scrutinised, and their learning progress is monitored. As a further step, the overall outcome of the improvement of learners’ knowledge regarding the given concepts is examined, using educational research tools.