bluuebunny/crossref_metadata_2025 huggingface dataset:
Block technology of speed and strength training of technical university students in cross-country athletics
Authors: Zyukin Anatoly , Gibadullin Ildus , Kovalchuk Oksana , Sagiev Talgat , Shelkova Lyudmila
Published: November 2020

This article deals with the problem of speed and power training of Omsk state technical University students in athletics classes during the academic year, taking into account their individual initial level of speed and power motor abilities development. The article describes the preparatory, forming and implementation blocks of the author’s developed block technology for building academic classes in cross-country athletics, shows the focus of classes on the development of specific modules. This study also involves testing the effectiveness of the developed block technology in the course of a pedagogical experiment. The author’s technology provides a two-cycle structure, that is, it covers academic classes of the first and second semesters. Significant differences in the planning of the experimental method classes consist in the development of lagging individual aspects of the student’s training, thereby selectively affecting and concentrating the development of speed-power, power and speed parameters of muscle work in running in separate classes. Moreover, the training tools in the forming and implementing blocks EG1, EG2 and CG do not differ, only the content of exercises changes by applying various pedagogical methods of regulating physical activity (changing the amount of burden, duration of work, rest, intensity, mode, character of muscle contraction). The results of research can be used in the educational process with schoolchildren, students of universities, colleges.
Gender based way in initial pre-professional training system of young football players
Authors: Suchilin Anatoly , Yakimovich Viktor , Stolyarchuk Lyudmila
Published: November 2020

The paper considers the gender-based way in initial pre-professional training of young football players (boys and girls) during their training in children’s and youth sport schools. The gender-based way and system analysis using allows us to get a handle on a system of initial training that includes a number of subsystems. All of them have a goal, objectives, program material and technology (methodology) for its implementation. Unlike the well-known studies, this one consists of using the same methodology in initial pre-professional training for joint football classes of boys and girls in age from 6 to 12 years old. This does not contradict their age characteristics and contributes to mutual enrichment in the development of technical and tactical techniques. From the age of 13, boys and girls begin to choose groups and football teams for in-depth pre-professional training to professional men’s and women’s football.
Competitive modelling in speed climbing
Authors: Shunko Andrey , Kravchuk Tatyana
Published: November 2020

The article analyzes the available scientific and methodological literature about training in the discipline of speed climbing. The speed climbing wall is described. It is divided into three parts with different characteristics, to clarify the specifics of the competitive distance. The physiological characteristics of competitive activity in speed climbing were studied.
Physical education of students in the format of distance education
Authors: Listkova Marina
Published: November 2020

The current difficult situation with the spread of the COVID 2019 virus forced us to take a new look at the workflow and rebuild medicine as well as the entire education system. The rapid development of computer technologies over the past ten years allows education to find a reasonable way out of a difficult situation. Thus, the existing system of distance education helped to continue students ‘education during the pandemic. The new format of education forced University lecturers (and other educational institutions) to look for the most appropriate and effective ways to implement the educational process. The Physical culture is not an exception. This article suggests and proves the most rational content of conducting remote physical education classes. They improve physical education help to maintain and strengthen the health of the younger generation.
Ankle joint traumas rehabilitation methods
Authors: Skitnevsky Vitaly , Grigoryeva Elena , Sedov Ivan , Krasilnikova Yulia , Balashova Valentina
Published: November 2020

Traumas of ankle joint are the most common. Ankle injuries account for 20 to 30% of all traumas of the human locomotor system. During the life process, the ankle is subjected to sufficiently heavy loads, therefore joint injuries often occur. Impact injuries, strains and ruptures of ligaments, dislocations, and fractures may be caused by any careless movement. Sedentary lifestyle causes atrophy of muscles and ligaments, their endurance decreases. That is why any improper movement may lead to an ankle trauma. The relevance of this article is determined by the search of ankle joint traumas rehabilitation methods, which in the future may be a solution to the problem of children 12 to 14 years of age recovery. The authors of the article have reviewed rehabilitation methods of ankle injuries and have analyzed the influence of physical activity on the recovery process. The goal of the research is to determine the effect of rehabilitation means aimed at recovery of the ankle joint motor function. We raised a question: how the use of physical rehabilitation means may favor the improvement of functional activity of the ankle joint.
Specifics of the impact of les mills fitness programs on the women’s physical fitness of 30-35 years of different somatotypes
Authors: Romanenko Natalia , Sudar Victoria , Raspopova Victoria , Yurkina Elizabeth , Ostapchuk Anastasia
Published: November 2020

At present, the increasing role of women in all areas of modern society is obvious. In this regard, the issue of preserving their health in the circumstances of a negative environmental situation, the intensification and computerization of labor activity is important and actual. Regular physical activity based on health-improving physical culture helps to improve the physical condition of women. There are some shortcomings in the physical education organization for women of the first Mature age. It leads to a lack of systematic growth in physical fitness indicators, and a decrease in motivation for physical education. It is important to find effective ways to improve the physical training of the first Mature age women and evaluate the effectiveness of various motor activity types. The article discusses the characteristics and influence of fitness programs in the Les Mills direction on the development of women physical qualities, taking into account different somatotypes. The results of the study made it possible to determine the somatotype according to the metric scheme of R. N. Dorokhov, body components, their severity and ratio, the physical capabilities of women 30-35 years old, depending on their somatic characteristics. In order to increase the level of physical fitness for each somatotype of women, fitness programs were selected based on the popular Les Mills direction. As a result of the study, the effectiveness of combining fitness tools that help increase the physical capabilities of women 30-35 years old with various somatotypic parameters was proved.
Formation of a health-preserving environment in preschool educational institutions
Authors: Martynova Victoria , Gazizova Farida , Galich Tatyana
Published: November 2020

The paper considers the use of health-saving environment in preschool educational institutions. The health-preserving environment model allows a child to develop favorably in a preschool educational institution. In the process of testing this model, we used the following research methods: analysis of scientific and methodological literature, morphofunctional indicators, analysis of physical fitness, methods of mathematical statistics. Initial analysis of morphofunctional indicators showed that all indicators meet the standards for this age of children, but the level of these indicators is not high enough. The analysis of physical indicators of preschool children corresponds to the average value for this age, but a large percentage cannot meet these requirements for the level of physical fitness. We obtained positive results in the course of the experiment for all the studied indicators, after the introduction of our model.
Improving the efficiency of planning training hours for cadets’ weapon practice
Authors: Kuznetsova Zinaida , Chaban Aleksey , Kotkova Larisa , Miftakhov Ruslan , Kuznetsov Stanislav
Published: November 2020

Cadets’ weapons practice is one of the important components of professional training. Its success is in the training hours’ distribution and mastering the main tasks at the early stages of military training. The correct distribution of weapon practice means and methods is very important. Planning of all weapon practice means begins with the definition of conditions and logistics. It is important to implement the principles of sports training. The implementation of the sports training basic principles during the school year allows expanding the cadets ’ body adaptation mechanisms to daily physical and mental stress. The development of innovative technologies for planning hours and the implementation of weapon practice tools allows to optimize and improve the effectiveness of cadets’ military training from the first year. Methodological aspects of planning and calculating hours by types of cadets’ weapon practice are presented, taking into account the tasks and direction of the training tools implementation. Difficulties are analyzed and ways to eliminate them in the process of improving the cadets weapon practice are found. The key tasks in the structure of weapon practice and the direction of their implementation are defined. The author’s version of cadets’ weapon practice planning allows to control and adjust both physical and mental loads.
Monte Carlo Method to Uncertainty Evaluation of The Relative Dielectric Constant and Loss Tangent Measured by Split-Cavity Resonator Technique
Authors: Zhao Fei , Pei Jing , Tang Qi , Wang Chengxiang , Kan Jinsong
Published: November 2020

According to the mathematical model of the split-cylinder resonator method, it is impossible to establish a simple equation between the intermediate variables and the relative dielectric constant or the loss tangent. Instead, the measured relative dielectric constant and the loss tangent must be calculated numerically by iterative programming. When evaluating uncertainty according to the Guide to the Expression of Uncertainty in Measurement (GUM), it is impossible to obtain the sensitivity coefficient of each intermediate. Therefore, the reliability of uncertainty evaluation is greatly reduced. ISO/TS15530 states that the most effective method for estimating uncertainty is computer simulation, and more specifically, a Monte Carlo simulation. In this study, Three typical samples with different relative dielectric constant and loss tangent were measured, respectively. The probability density function of each intermediate variable was given, according to which the Monte Carlo simulations were performed by MATLAB programming. Moreover, some of the simulation results are compared with those of the previous literature, and the results show that the measurement uncertainty evaluated by the GUM method was slightly larger, indicating that it was a little bit conservative to assume that each intermediate variable is completely uncorrelated in the GUM method.
Simulation of Electrical Characteristics on Inhomogeneous Strains in Normally-off HEMTs with p-GaN Gate
Authors: Zhou Jing , Chen Hongjun , Wang Yang , Long Xingming
Published: November 2020

Strain is one of the important factors affecting the two-dimensional electron gas (2DEG) transform in AlGaN/GaN material based high electron mobility transistors (HEMTs) by polarization effects. In this paper, the effects of inhomogeneous biaxial strain in different regions of the AlGaN barrier layer on electrical properties of normally-off HEMTs with p-GaN gate were discussed. The results show that biaxial strain applied in three regions has different influence on transfer, output and breakdown characteristics of the device. The strain applied in region under gate has the most significant impact on threshold voltage and drain saturation current with a decreasing of 39% and an increasing of 97% respectively as the strained lattice constant increases from 3.173061Å to 3.187229Å.While, strain applied between gate and drain electrode can improve the off-state breakdown voltage by 12% with the increasing of strained lattice constant.
Accelerated testing of track vehicle torsion bar
Authors: Furch Jan , Nguyen Quy Hung , Stodola Jiri
Published: November 2020

The suspension system of track vehicles is often equipped with torsion bars. The torsion bar is a key element of the vehicle's suspension system. The service life of torsion bars depends primarily on the quality of the material used, the diameter of the torsion bars and the method of attachment and placement. In order to obtain the characteristics of the torsion bar, an experimental test stand was created on which accelerated tests were performed. Furthermore, a virtual model of torsion bar operation was created. The torsion bar was modelled using finite elements (FE part). Dynamic simulation was performed using MSC Adams software. Finally, the values measured in the accelerated tests and the results of simulations were compared. Comparing the values found, it was proved that this difference is not significant. This virtual model can be used to investigate the service life of torsion bars and to predict their service life.
Liquid Biopsy in Breast Cancer
Authors: Banys-Paluchowski Maggie , Krawczyk Natalia , Fehm Tanja
Published: November 2020

In recent years, the blood-based analysis of circulating tumour cells (CTCs) and nucleic acids (DNA/RNA), otherwise known as liquid biopsy, has become increasingly important in breast cancer. Numerous trials have already underscored the high prognostic significance of CTC detection in both early and metastatic stages. Moreover, the changes in CTC levels and circulating tumour DNA (ctDNA) during the course of the disease correlate with the response to treatment. Research currently focuses on liquid-biopsy based therapeutic interventions in metastatic breast cancer. In this context, alpelisib, a PI3K inhibitor, was the first agent to be approved by FDA and EMA.
StäB – eine Einschätzung aus der Betroffenenperspektive
Authors: Prestin Elke
Published: November 2020

Das psychiatrische Hilfesystem muss konsequent an den individuellen Bedürfnissen der psychisch erkrankten Menschen ausgerichtet sein. Die StäB kann auf struktureller Ebene einen wichtigen Baustein komplexer, bedarfsgerecht nutzbarer Angebote bilden. Zentral ist aber eine recovery-orientierte Grundhaltung, die menschliche Fürsorge und Empowerment verbindet.
Der Standstereotyp – Mehr als nur posturale Spannung
Authors: Best Norman , Kreher Andreas , Aurich Matthias
Published: November 2020

Hintergrund Das aufrechte Stehen wird im klinischen Alltag oft nicht als motorischer Stereotyp angesehen. Neben artikulären und myofaszialen Defiziten kann aber auch das Zusammenspiel der Einzelkomponenten gestört sein.

Material und Methoden Beschrieben wurden Tests, die Rückschlüsse zum Bewegungsstereotyp des Stehens zulassen. Ergebnisse Es liegen wenige motorische Testverfahren zur Evaluation des Standstereotyps vor. Die größte Anzahl der Test am Bewegungssystem zielen auf Gelenkfunktion, Muskulatur und Schmerz ab.

Diskussion Die Kombination ausgewählter Motoriktests für den Standstereotyp lassen Rückschlüsse auf diesen Bewegungsstereotyp zu. Nach Berücksichtigung der Diagnostikpfade: Strukturpathologie, Gelenkfunktionsstörung, myofasziale Funktionsstörung, fasziale Funktionsstörung, sind bei therapierefraktären Störungen die motorischen Stereotype zu berücksichtigen. Die angegebenen Testverfahren können zur Weiterevaluation des Bewegungssystems wertvoll sein.

Schlussfolgerungen Durch Nutzung von Testverfahren zur Evaluation des Standstereotyps sind differenziertere Aussagen bei Beschwerden des Bewegungssystems möglich.
Die soziale Lebenswelt im digitalen Raum – DGPPN 2020
Authors: Karow Anne
Published: November 2020

Das Grußwort des DGPPN Kongresses 2020 trägt den Titel
„Psychiatrie und Psychotherapie in der sozialen Lebenswelt“.
Gleichzeitig hält das Coronavirus uns alle weiterhin von Reisen und
Großveranstaltungen ab, die bereits jetzt bis Ende 2020 in weiten Teilen der
Republik abgesagt wurden. Der DGPPN Kongress hat sich bereits vor vielen Monaten
darauf eingestellt und wird vom 26. bis 28. November 2020, wie so viele andere
Veranstaltungen in diesem Jahr, erstmalig als digitales Event stattfinden.
Das qualitative Interview und die notwendige Haltung der Offenheit
Authors: Xyländer Margret
Published: November 2020

Der Beitrag nimmt die in den Rehabilitationswissenschaften häufig verwendete Erhebungsform des qualitativen Interviews und seine praktische Durchführung in den Blick. Einen wesentlichen Aspekt der Interviewführung stellt – neben Merkmalen der Prozesshaftigkeit und Kommunikation – die Haltung der Offenheit dar. Diese umfasst im qualitativen Forschungsprozess mehrere Aspekte, die hier konkret benannt werden. Dies beginnt mit einer methodologischen Offenheit bei der Auswahl und Anwendung geeigneter Methoden für den zu untersuchenden Forschungsgegenstand. Die Haltung der Offenheit setzt sich im Forschungsprozess weiter fort, wenn eventuelle Anpassungen im Vorgehen notwendig werden, die dann auch Gegenstand methodischer Reflexion sein können und sollten. Offenheit bezieht sich damit auf den gesamten Forschungsprozess und seine unvorhergesehenen Ereignisse und Verläufe. Eine Haltung der Offenheit meint aber auch und insbesondere eine Aufgeschlossenheit gegenüber den Befragten wie auch gegenüber der Interviewsituation und ihren Rahmenbedingungen. Nicht zuletzt erfordert dies eine Offenheit gegenüber sich selbst im Sinne einer Reflexion der eigenen Selbstverständlichkeiten, um Interview(nach)fragen möglichst wenig vorzustrukturieren.
Ensemble Learning Approach with LASSO for Predicting Catalytic Reaction Rates
Authors: Yada Akira , Sato Kazuhiko , Matsumura Tarojiro , Ando Yasunobu , Nagata Kenji , Ichinoseki Sakina
Published: November 2020

The prediction of the initial reaction rate in the tungsten-catalyzed epoxidation of alkenes by using a machine learning approach is demonstrated. The ensemble learning framework used in this study consists of random sampling with replacement from the training dataset, the construction of several predictive models (weak learners), and the combination of their outputs. This approach enables us to obtain a reasonable prediction model that avoids the problem of overfitting, even when analyzing a small dataset.
Epilepsy—Definition, Classification, Pathophysiology, and Epidemiology
Authors: Falco-Walter Jessica
Published: November 2020

Seizures affect the lives of 10% of the global population and result in epilepsy in 1 to 2% of people around the world. Current knowledge about etiology, diagnosis, and treatments for epilepsy is constantly evolving. As more is learned, appropriate and updated definitions and classification systems for seizures and epilepsy are of the utmost importance. Without proper definitions and classification, many individuals will be improperly diagnosed and incorrectly treated. It is also essential for research purposes to have proper definitions, so that appropriate populations can be identified and studied. Imprecise definitions, failure to use accepted terminology, or inappropriate use of terminology hamper our ability to study and advance the field of epilepsy. This article begins by discussing the pathophysiology and epidemiology of epilepsy, and then covers the accepted contemporary definitions and classifications of seizures and epilepsies.
Does Intraoperative Diuretic Therapy Affect the Thoracic Fluid Content and Clinical Outcome in Patients Undergoing Mitral Valve Surgery?
Authors: Choudhury Minati , Narula Jitin , Saini Kulbhushan , Kapoor Poonam Malhotra , Kiran Usha
Published: November 2020

Pulmonary congestion is inevitable in valvular heart disease. The condition worsens when a patient undergoes cardiopulmonary bypass (CPB). Thoracic fluid content (TFC) is an indicator of total volume status of lung in health and disease. We hypothesize that intraoperative diuretic therapy can improve the hemodynamic and clinical outcome in patients undergoing mitral valve surgery by decreasing TFC as measured by impedance cardiography (ICG).

Sixty adult patients with critical mitral stenosis scheduled for mitral valve surgery divided into diuretic (Gr D, n = 30) and control (Gr C, n = 30) group. One mg/kg of furosemide was administered before CPB to Gr D and similar volume of normal saline to Gr C. Hemodynamic and TFC measurements were done by index of contractility (ICON), NICOM monitor at baseline, before anesthesia induction (T1), post skin closure (T2), postoperatively at 6th hour (T3), 24th hour (T4), and 48th hour (T5). The duration of mechanical ventilation (hour), intensive care unit stay (day) and inotropic score was significantly higher in Gr C (5.29 ± 1.4 vs. 2.15 ± 1.1; p = 0.001; 2.11 ± 0.64 vs. 1.67 ± 0.57, p = 0.002; 9 ± 5.4 vs. 5.8 ± 3.2, p = 0.05), respectively. Three patients in Gr C developed respiratory complication during their course of hospital stay. The baseline TFC value was comparable (p = 0.08). In Gr C. it gradually increased over time and never reached the baseline value, whereas in Gr D, there was slight increase in TFC till 6th postoperative hour and it came below the baseline value at 48th hour. A significantly higher TFC value in Gr C in comparison with Gr D from 6th to 48th postoperative hour (p = 0.005, 0.000, and 0.005, respectively) was observed.

The ICON had a gradual improvement from 12th over 48th postoperative hour in Gr D in comparison to Gr C. The systemic vascular resistance index was decreased over time in Gr C, whereas in Gr D there was a mild fall at the end of surgery and it came back to near the baseline value at 48th postoperative hour. A continuous decrease in DO2 I except at 6th postoperative hour was seen in Gr C, whereas it remained near the baseline value in Gr D.

Linear regression analysis showed significant direct correlation of TFC with intraoperative fluid balance (r = 0.524, p = 0.001), cumulative fluid balance (r = 0.680, p = 0.000) and both peak and mean airway pressure (r = 0.436, p = 0.001 and r = 0.548, p = 0.001, respectively).

We concluded that TFC is clearly influenced by intraoperative diuretic therapy. A decrease in TFC has an association with better hemodynamic parameters that could find interesting clinical applications in the decision, whether or not to include a diuretic as a routine therapy during intraoperative management in valve surgery patients.
4.4.32.14 Allenylsilanes (Update 2020)
Authors: Krause N. , Arisetti N.
Published: November 2020

This review is an update to the earlier Science of Synthesis coverage of the synthesis of allenylsilanes (Section 4.4.32). It covers the literature published between 2000 and 2020.

The SN2 substitution of propargylic electrophiles (alcohols, oxiranes, carboxylates, sulfonates, phosphates, halides, etc.) is the most frequently used synthetic pathway to allenylsilanes. Hereby, the silyl group is either already bound to the propargylic substrate, or it is introduced using a suitable silyl nucleophile (silylcuprate, silylboronate, etc.). These methods often take advantage of transition-metal (palladium, rhodium, copper, gold, etc.) catalysis. Alternatively, propargylic nucleophiles (boranes, silanes, stannanes) are reacted with suitable electrophiles. Many of these methods can be applied to the diastereo- and/or enantioselective synthesis of allenylsilanes by using stereochemically defined starting materials or suitable chiral ligands. It is also very useful to start with allenes and convert them into allenylsilanes by deprotonation and trapping with silyl electrophiles, or by transition-metal-catalyzed coupling reactions. Conjugated ynones, enynes, and dienes also represent important classes of starting materials for the synthesis of allenylsilanes by different types of addition reactions. Finally, highly reactive substrates and reagents (silylketenes, diazo compounds, cyclopropanes, and cyclopropenes) can be readily transformed into silylallenes by alkenation, insertion, or ring-opening reactions.
Erosion sensor using time-resolved cavity ring-down spectroscopy for Hall thrusters
Authors: Egawa Yusuke , Yamamoto Naoji , Yamaguchi Atsushi , Morita Taichi
Published: November 2020

A high-sensitivity sensor to measure titanium atom density based on time-resolved cavity ring-down spectroscopy (CRDS) was developed to monitor the wall erosion and predict the lifetime of Hall thrusters. The minimum detection limit for the sensor was dependent on the discharge current oscillation in the Hall thruster. A Volterra engine management system was employed for time-resolved measurements to develop the time-resolved CRDS system, which was synchronized to the discharge current oscillation. The results confirmed that the path-integrated number density of sputtered titanium atoms was synchronized with the discharge current oscillation. The minimum detection limit was decreased by ∼30% from 2 × 1012 to 6 × 1011 m−2.
Laser wakefield acceleration driven by a few-terawatt laser pulse in a sub-mm nitrogen gas jet
Authors: Lin M.-W. , Chu T.-Y. , Chen Y.-Z. , Tran D. K. , Chu H.-H. , Chen S.-H. , Wang J.
Published: November 2020

Quasi-monoenergetic electron bunches with energies peaked in 10–20 MeV are generated from laser wakefield acceleration (LWFA) by focusing few-TW laser pulses onto a sub-mm gas jet of dense nitrogen. A 152-μm diameter orifice is used to produce transient (≤20 ms), free-flow nitrogen jets, while the plasma electrons with a 860-μm wide Gaussian density profile and a density up to ∼2.8 × 1019 cm−3 enable self-focusing effect and self-modulation instability to develop on the pump pulse, resulting in a high intensity to drive the LWFA. Meanwhile, this Gaussian nitrogen plasma facilitates ionization-induced injection and density down-ramp injection throughout the acceleration process and consequently improves the energy and charge stabilities of output electrons. When 40-fs, 3.2-TW, 810-nm pump pulses are applied, output electrons with a peak energy ∼11 MeV and a charge ∼20 pC are routinely generated with ≤20% energy and charge stabilities, ∼20 mrad divergence, and ∼10 mrad pointing variation. A large electron energy spread is attributed to the dominant mechanisms of ionization and down-ramp injections. This scheme represents a viable approach for implementing a high-repetition-rate LWFA, from which stable tens-of-MeV electrons can be generated with less than 150 mJ of on-target laser energy.
Fill tube dynamics in inertial confinement fusion implosions with high density carbon ablators
Authors: Baker K. L. , Thomas C. A. , Dittrich T. R. , Landen O. , Kyrala G. , Casey D. T. , Weber C. R. , Milovich J. , Woods D. T. , Schneider M. , Khan S. F. , Spears B. K. , Zylstra A. , Kong C. , Crippen J. , Alfonso N. , Yeamans C. B. , Moody J. D. , Moore A. S. , Meezan N. B. , Pak A. , Fittinghoff D. N. , Volegov P. L. , Hurricane O. , Callahan D. , Patel P. , Amendt P.
Published: November 2020

Plasma jets, such as γ-ray burst jets, Herbig–Haro jets, μ-quasar jets, and active galactic nuclei jets, are found throughout the universe [S. Mendoza et al., Rev. Mex. Astron. Astrofis. 41, 453 (2005)]. Plasma jets are also present in indirect drive inertial confinement fusion experiments originating from the capsule's fill tube and occasionally from divots and voids in the capsules, particles on the exterior of the capsule, or from the tent holding the capsule in the target. This paper looks at two different gas-filled capsule implosions containing a plasma jet resulting from a capsule fill tube and fill channel, both of which utilized high density carbon ablators. Two models were developed, a drag and a snowplow model, which use the time-dependent motion of the injected mass through the hotspot to estimate the mass injected into the hotspot from the fill tube and channel, arriving at an average injected mass of ∼84.5 ± 25.5 ng for the first experiment and 91 ± 20 ng for the second experiment. Unlike previous methods to estimate fill tube injected mass, these techniques do not assume that the mixed mass is in thermal equilibrium with the hotspot or that the x-ray emission is only coming from within the hotspot itself. This paper also discusses the features seen in these experiments which include limb brightening in the shell for undoped ablators and flattening in the ablator from shadowing by the fill tube.
Reconstructing regime-dependent causal relationships from observational time series
Authors: Saggioro Elena , de Wiljes Jana , Kretschmer Marlene , Runge Jakob
Published: November 2020

Inferring causal relations from observational time series data is a key problem across science and engineering whenever experimental interventions are infeasible or unethical. Increasing data availability over the past few decades has spurred the development of a plethora of causal discovery methods, each addressing particular challenges of this difficult task. In this paper, we focus on an important challenge that is at the core of time series causal discovery: regime-dependent causal relations. Often dynamical systems feature transitions depending on some, often persistent, unobserved background regime, and different regimes may exhibit different causal relations. Here, we assume a persistent and discrete regime variable leading to a finite number of regimes within which we may assume stationary causal relations. To detect regime-dependent causal relations, we combine the conditional independence-based PCMCI method [based on a condition-selection step (PC) followed by the momentary conditional independence (MCI) test] with a regime learning optimization approach. PCMCI allows for causal discovery from high-dimensional and highly correlated time series. Our method, Regime-PCMCI, is evaluated on a number of numerical experiments demonstrating that it can distinguish regimes with different causal directions, time lags, and sign of causal links, as well as changes in the variables’ autocorrelation. Furthermore, Regime-PCMCI is employed to observations of El Niño Southern Oscillation and Indian rainfall, demonstrating skill also in real-world datasets.
Transition of charge transport phenomena from 3D to 1D hopping at low temperatures in polyaniline/graphene composites
Authors: Pal Rishi , Goyal Sneh Lata , Rawal Ishpal
Published: November 2020

Here, we present the charge transport properties of polyaniline/graphene composites prepared by a chemical oxidation method in the presence of four different loading concentrations (2, 4, 6, and 8 wt. %) of graphene. The synthesized materials are characterized for surface and chemical bonding analyses through field-emission scanning electron microscopy and Fourier transform infrared spectroscopy techniques, respectively. The change in the chemical structure of the prepared composites with graphene loading concentrations revealed the possible increment in electrical conductivity. The room-temperature dc conductivity of the prepared composites was found to increase from ∼22 to 217 S/cm with an increase in the loading concentration of graphene from 2 to 8 wt. %. The temperature-dependent electrical conduction behavior of the prepared samples is investigated under Mott's variable-range hopping conduction mechanism. It is found that all composite samples follow three-dimensional (3D) hopping in the higher temperature region (>44 K), which transforms into one-dimensional (1D) hopping at lower temperatures (<44 K). A decrease in hopping distance (1.07–0.96 nm) and an increase in density of states (3.20 × 1021–4.95 × 1021 cm−3 eV−1) in three dimensions with an increase in the graphene loading concentration from 2 to 8 wt. % suggest the requirement of lower hopping energy (61.3–55.5 meV) for conduction. The estimated hopping parameters also revealed a nonadiabatic small-polaron hopping conduction mechanism that is followed by the charge carriers in the present samples for both one- and three-dimensional variable range hoppings.
High polarization and fast modulation speed of dual wavelengths electroluminescence from semipolar (20-21) micro light-emitting diodes with indium tin oxide surface grating
Authors: Zhang Haojun , Li Panpan , Li Hongjian , Song Jie , Nakamura Shuji , DenBaars Steven P.
Published: November 2020

We present highly polarized dual wavelength semipolar InGaN micro-light-emitting diodes (μLEDs) by combining an indium tin oxide (ITO) surface grating and Al-coated dual-color surface plasmons (DSPs). The ITO grating DSPs enable a significant enhancement of the polarization ratio (PR) from electrically driven semipolar (20-21) μLEDs with dual emission wavelengths: the overall PR was increased by 1.7-folds and the output power was enhanced by 78% as compared to the conventional semipolar μLEDs at an injection current density of 100 A/cm2. Moreover, a high 3 dB modulation bandwidth of 612 MHz is achieved at ∼1.4 kA/cm2 in a visible-light communication (VLC) system, suggesting a near 1.24 Gbit/s under a non-return-to-zero on-off keying modulation scheme. This design marks significant progress in developing polarized μLEDs with potential applications in various fields, such as displays and VLC.
A terahertz Brewster switch based on superconductor hyperbolic metamaterial
Authors: Sreekanth Kandammathe Valiyaveedu , Mahalakshmi P. , Han Song , Vigneswaran D. , Mani Rajan M. S. , Jha Rajan , Singh Ranjan
Published: November 2020

Active polarization switching devices are important to control the polarization state of light including terahertz (THz) waves that are technologically challenging to manipulate. Here, we propose and numerically demonstrate a hyperbolic metamaterial-based (HMM-based) active Brewster polarization switch for the intensity and phase modulation of THz light. The proposed multilayered HMM consists of alternating thin layers of high temperature superconductors such as yttrium barium copper oxide and dielectric materials such as lanthanum aluminate. The HMM shows elliptical dispersion above the superconducting phase transition temperature and type II hyperbolic dispersion in the superconducting state. By varying the temperature from the dielectric to the superconducting phase of the HMM, we demonstrate above 98% THz intensity modulation and 100% phase tunability (180°) at Brewster’s angle. The proposed HMM can work as an efficient reflective THz modulator by properly selecting the angle of incidence.
Rotational and fine structure of open-shell molecules in nearly degenerate electronic states. II. Interpretation of experimentally determined interstate coupling parameters of alkoxy radicals
Authors: Yan Yi , Sharma Ketan , Miller Terry A. , Liu Jinjun
Published: November 2020

Rotationally and fine-structure resolved B̃←X̃ laser-induced fluorescence (LIF) spectra of alkoxy radicals have been simulated with a “coupled two-states model” [J. Liu, J. Chem. Phys. 148, 124112 (2018)], in which the nearly degenerate X̃ and Ã states are considered together. These two electronic states are separated by the “difference potential” and coupled by the spin–orbit (SO) interaction and the Coriolis interaction. Molecular constants determined in fitting the LIF spectra using the coupled two-states model provide quantitative insight into the SO and Coriolis interactions, as well as other intramolecular dynamics, including the pseudo-Jahn–Teller effect. The spectroscopic model also allows semi-quantitative prediction of effective spin-rotation constants using molecular geometry and SO constants, which can be calculated ab initio with considerable accuracy. The dependence of fit values of molecular constants on the size and conformation of alkoxy radicals is discussed.
Nonequilibrium molecular dynamics study on energy accommodation coefficient on condensing liquid surface—Molecular boundary conditions for heat and mass transfer
Authors: Tokunaga Atsushi , Tsuruta Takaharu
Published: November 2020

Nonequilibrium molecular dynamics (NEMD) studies have been conducted to determine molecular boundary conditions at vapor–liquid interfaces for the kinetic theory of condensation and evaporation. In previous studies, a microscopic formulation of the condensation coefficient was defined as the condensation probability of vapor molecules based on equilibrium molecular dynamics simulations and transition state theory. The condensation coefficient was presented as a function of the translation energy of incoming molecules and surface temperature. Based on this, the velocity distributions of evaporating and reflecting molecules were theoretically expressed under equilibrium conditions. In a practical nonequilibrium situation, the energy transfer by the reflecting molecules is important along with the condensation/evaporation probability. However, it is unclear whether the results obtained under equilibrium conditions can be applied under nonequilibrium conditions. This study, therefore, defines the energy accommodation coefficient of reflecting molecules by comparing the energy transfer due to reflection with that under equilibrium conditions. NEMD simulations are conducted using two surfaces facing each other, an evaporating surface and a condensing surface, for argon molecules under different nonequilibrium conditions. The results show that the velocity distribution of reflecting molecules deviates from those under equilibrium conditions, and the energy accommodation coefficient decreases as nonequilibrium conditions increase. Additionally, an inverted temperature profile is observed. Reflecting molecules play an important role in the sensible heat transfer on the condensing surface, and they are not accommodated on the condensing surface. Thus, they raise the temperature in the vicinity of the condensing surface under nonequilibrium conditions.
Graphene-induced crystal-healing of AlN film by thermal annealing for deep ultraviolet light-emitting diodes
Authors: Chang Hongliang , Liu Bingyao , Liang Dongdong , Gao Yaqi , Yan Jianchang , Liu Zhetong , Liu Zhiqiang , Wang Junxi , Li Jinmin , Gao Peng , Wei Tongbo
Published: November 2020

We achieve stress-free AlN films with low dislocation density by employing Graphene (Gr)-induced crystal-healing via high-temperature annealing (HTA). The N2 plasma-treated Gr effectively facilitates the formation of high-density and small-size AlN grains during the initial quasi-van der Waals epitaxial growth. Thus, it is easier to rotate the inhomogeneous crystal orientation for subsequent AlN epilayers during the HTA process, greatly improving the recrystallization efficiency of AlN. Due to the improved AlN quality, the 283-nm deep ultraviolet light-emitting diode (DUV-LED) on the HT-annealed AlN with Gr shows a significant increase in light output power of 2.3 times at an injection current of 20 mA compared to its counterpart on bare sapphire. This research broadens the applications of Gr in assisting group-III nitride epitaxy and provides a useful strategy for the manufacture of high-quality AlN and high-performance DUV-LEDs.
Study of effect of magnetic field on the axisymmetric vortices produced by a novel vortex generator in a rectangular channel using dynamic mode decomposition
Authors: Kashyap Uddip , Kumar Ashish , Saha Sandip K.
Published: November 2020

The introduction of a magnetic field greatly influences the nanofluid flow in a channel. The current study uses a novel vortex generator (VG) to produce a couple of axisymmetric vortices behind the VG at Re = 6000. These vortices are significantly affected by the strength of the magnetic field. The considered cases are identical and vary only with the change in intensity of the magnetic flux. Initially, at Ha = 5, both vortices P1 and P2 are stretched; however, vortex P2 is stretched significantly in comparison to vortex P1. Such stretching enhances the rotational speed of the vortices resulting in the increment of the overall heat transfer rate by 7.1%, when compared to the case with no magnetic flux. With the increase in magnetic flux, the produced vortices are stretched to such an extent that results in the loss of the majority of its span, leading to the decrement in heat transfer rate from the heated base plate to the flowing fluid. For Ha = 50, the heat transfer rate registers a loss of about 45.4%. Finally, the study of the dynamic mode decomposition reveals that the first dominant mode is 10 times higher than the second and third dominant modes.
An experimental study of respiratory aerosol transport in phantom lung bronchioles
Authors: Mallik Arnab Kumar , Mukherjee Soumalya , Panchagnula Mahesh V.
Published: November 2020

The transport and deposition of micrometer-sized particles in the lung is the primary mechanism for the spread of aerosol borne diseases such as corona virus disease-19 (COVID-19). Considering the current situation, modeling the transport and deposition of drops in human lung bronchioles is of utmost importance to determine their consequences on human health. The current study reports experimental observations on deposition in micro-capillaries, representing distal lung bronchioles, over a wide range of Re that imitates the particle dynamics in the entire lung. The experiment investigated deposition in tubes of diameter ranging from 0.3 mm to 2 mm and over a wide range of Reynolds number (10−2 ⩽ Re ⩽ 103). The range of the tube diameter and Re used in this study is motivated by the dimensions of lung airways and typical breathing flow rates. The aerosol fluid was loaded with boron doped carbon quantum dots as fluorophores. An aerosol plume was generated from this mixture fluid using an ultrasonic nebulizer, producing droplets with 6.5 µm as a mean diameter and over a narrow distribution of sizes. The amount of aerosol deposited on the tube walls was measured using a spectrofluorometer. The experimental results show that dimensionless deposition (δ) varies inversely with the bronchiole aspect ratio (L¯), with the effect of the Reynolds number (Re) being significant only at low L¯. δ also increased with increasing dimensionless bronchiole diameter (D¯), but it is invariant with the particle size based Reynolds number. We show that δL¯∼Re−2 for 10−2 ⩽ Re ⩽ 1, which is typical of a diffusion dominated regime. For Re ⩾ 1, in the impaction dominated regime, δL¯ is shown to be independent of Re. We also show a crossover regime where sedimentation becomes important. The experimental results conclude that lower breathing frequency and higher breath hold time could significantly increase the chances of getting infected with COVID-19 in crowded places.
1989
Authors: Crane H. Richard
Published: November 2020

Wind chill figures will be heard in most radio newscasts this month—at least in the parts of the country that have a winter. If you have a computer and punch in the little program given here, you will be able to check the experts.
1991
Authors: Crane H. Richard
Published: November 2020

More than two years ago Jon Roberts (student) and Dean Hecht (teacher) of Superior Senior High School asked why a fishing spinner spins.
TECHNOLOGY
Authors: Feltyberger Earl R. , Mallmann James , Schmidt Judy M. , Senior Thomas
Published: November 2020

In performing the experiments contained in this workshop, no equipment more sophisticated than a digital multimeter is required. The Radio Shack DMM contained in the equipment list in section 1 makes readings about 5 times every second (has a sampling rate of 5 Hz). So it is suitable for measuring values which do not change, or change slowly.
MODERN PHYSICS
Authors: Feltyberger Earl R. , Mallmann James , Schmidt Judy M. , Senior Thomas
Published: November 2020

Although a very brief discussion of p-type and n-type semiconductors is given in section 2 of this workshop, it is advisable that someone who wishes to present this workshop should possess more knowledge about semiconductors than has been presented here. Below are suggestions for further reading taken from the books in the bibliography contained in section 1 of this workshop.
Front Matter
Authors: Nelson Jane Bray , Nelson Jim
Published: November 2020

Frontmatter and acknowledgments for Teaching About Kinematics: An AAPT/PTRA Resource.
Care and Maintenance of Equipment
Authors: Kallard T.
Published: November 2020

The following suggestions for routine care of the equipment will help to prolong its useful life.
Lazy Susan Optics Table
Authors: Kallard T.
Published: November 2020

Ray diagrams are commonly used to illustrate light paths in optical devices. The illuminating system of the lazy susan optics table allows the observer to see actual paths created by real beams of light as they are reflected and refracted by mirrors, glass blocks, prisms, lenses and combinations of these optical elements.
Lazy Susan Exercises
Authors: Kallard T.
Published: November 2020

Reflectance and Transmittance.

NOTE: All drawings show the setup from above unless otherwise noted.
Optical Lever
Authors: Kallard T.
Published: November 2020

A small mirror is attached to an object. If a laser beam is reflected from this mirror onto a distant wall or screen, any small motion of the object will be greatly magnified in the motion of a bright red spot formed by the reflected beam. This comprises an optical lever.
Visual Display of Sound Dynamics
Authors: Kallard T.
Published: November 2020

The object of the demonstration is to produce a light pattern for each tone or combination of tones presented to the apparatus in the form of time-varying electrical signals which correspond to sound signals.
Curving and Bouncing Laser Beam
Authors: Kallard T.
Published: November 2020

A light beam is deflected by a prism - that is, by a transparent material of uniform refractive index and varying width. A transparent slab of material (glass or plastic) also deflects a light beam, the amount of deflection being a function of the width of the slab. In case of a mirage which forms over hot sand, the light beam is deflected by the refractive index gradient in the air due to the temperature gradient close to the ground. In such cases as the Fata Morgana, or light reflection on a hot road surface, the light rays bend upward.
Recording and Measuring Refractive Index Gradients
Authors: Kallard T.
Published: November 2020

The spatial variation of the refractive index in the mixing zone of two liquids can be determined from the observed and recorded deflection of a laser beam.
The Plane Parallel Plate as an Optical Micrometer
Authors: Kallard T.
Published: November 2020

A laser beam incident at right angles on a rectangular block of glass (or lucite) passes through without displacement. If the block is rotated by an angle ε, the emerging laser beam will undergo a parallel displacement to the incident beam (see Fig. 88).
Voice and TV Picture Transmission Over a Laser Beam
Authors: Kallard T.
Published: November 2020

Communication systems are among the most important applications of the laser. Picture, voice and data transmisssion systems employing a laser beam can be easily demonstrated in the laboratory or classroom.
The “Guest-Host” Effect
Authors: Kallard T.
Published: November 2020

In 1968, G.H. Heilmeier and L.A. Zanoni reported a new electro-optic effect based on “guest-host” interactions in nematic liquid crystals (NLCs). The “guest-host” effect is observed when an electric field acts on a NLC (the host) containing as the additive (the guest) dichroic dye molecules that absorb light anisotropically. The orientation of the guest is controlled by the orientation of its nematic host, provided the additive molecule has an elongated shape.
Liquid Crystal Temperature Detection Device
Authors: Kallard T.
Published: November 2020

Optical activity in mesomorphic media was first observed in derivatives of cholesterol, and media which show this phenomenon are therefore termed cholesteric media.