bluuebunny/crossref_metadata_2025 huggingface dataset:
How does an athlete’s heart react to studying at university?
Authors: Popova Tatiana , Koriukalov Yurj , Kourova Olga , Gurlev Vladimir , Khomykova Tatiana
Published: November 2020

2 groups of participants have been studied: I – student-athletes; II – students and postgraduate students, not involved in sport. The functional status of the heart has been studied in three conditions: at rest, during the cognitive test, and under local static load (the wrist dynamometer). The electroencephalography has also been applied. Results demonstrated a statistical decrease in wrist endurance in all participants during the academic year. They proved fatigue development. A pronounced increase of heart rate and arterial blood pressure, as well as the increase of heart rate variability mode and stress index under local load and during the cognitive test, proved the development of the heart functional stress, especially in athletes. Electroencephalography data prove the central origin of adaptation reactions both to mental and to local muscular activity. Disease prevention and health improvement measures are necessary for university students actively involved in sport. One of such measures is relaxation exercises aimed at a decrease in functional stress.
Gender differences in the rate of motor activity of senior (older) preschool children
Authors: Voloshina Lyudmila , Kondakov Victor , Kopeikina Evgeniya , Galimskaia Olga , Arseenko Elena
Published: November 2020

The relevance of the research is determined by the search for ways to improve the content of physical education of preschool children and increase its effectiveness in gender-based motor activity. Goal: to identify gender differences in older preschoolers’ motor activity. Research materials: the study involved preschool children aged 5-7 years who attend pre-school in Belgorod. Research methods: study, analysis and comparison of scientific publications of domestic and foreign scientists on the problem of research, pedometer, heart rate monitoring, timing, statistical processing of the results. Results: the features of motor activity of boys and girls aged 5-7 years were studied in such indicators as daily and weekly volume in steps, intensity in organized forms and independent activity. Conclusions: gender differences in the size, structure, and content of motor activity are most noticeable at the age of five. There are no gender differences in motor activity of preschool children aged 6-7 years. Significant gender differences in children aged 5-7 years are only in indicators of motor activity recorded on weekends, outside of classes. The value of motor activity of children aged 5-7 years corresponds to the age norm of average daily motor activity.
Psychophysical adaptation of visually impaired students through Showdown game
Authors: Kokhan Sergey , Grabovskaya Yana , Vinogradova Nina , Nadeina Luiza
Published: November 2020

The article deals with the problem of visual defects compensation for psychophysiological activity and adaptation of students in the process of studying at a university. The aim of the study was to test the effect of showdown training on several indicators of growth in physical activity and capabilities, including psychological adaptation. The data obtained from showdown classes in combination with APE showed a significant decrease in the general experience of students with visual impairment, the quality of interpersonal communication and communication capabilities increased. There was also a significant increase in the range of motion in the joints, an improvement in fine motor skills of the hands, and the rate of hand movements. The results of the experiment show that showdown is a promising effective option for classes and trainings that contribute to the improvement of physical activity, psychological adaptation and a positive effect on physical activity and endurance of students with abnormal vision of students at the university.
Potential of deconcentration of attention methods for use in the information society
Authors: Ermakov Alexey
Published: November 2020

This paper is devoted to the results of our issues exploration increasing efficiency action in extreme circumstances. Long time we study only combat oriented activities but now it is obvious that work with information torrents has the same features of stress as a fight. Our exploration was based on Oleg Bakhtiyarov ideas who study deconcentration of attention phenomenon. We adapted these ideas and combined traditional for our country approaches to hand-to-hand combat and special software. We used two main ideas for experiments. The first one was searching for hidden threats and stealthy attacks with deconcentration and after that was concentration attention on threats and destroying them. This gave us only part-time at deconcentration. We used “plane deconcentration” for searching and “multidimensional deconcentration” for action. The second idea was about using deconcentration for avoiding dangerous situations. That case was about full-time deconcentration. We discovered two types of usage deconcentration indirect or without direct contact with attackers but not only this feature and we need to explore it in the future. We discovered the same features in combat activities and works with information torrents. In addition, the same features were discovered between our data and the other from e-sports. In addition, the same features were discovered between our data and the other from e-sports. All of that gives us opportunities to use the deconcentration of attention methods for tasks that are needed for operators and common people in the information society (searching, detection, distinguishing, and filtration of information torrent) and, of course, for mental hygiene goals.
The muscles’ relaxation characteristics improvement of belt wrestlers using exercises on the basis of the instantaneous simulators
Authors: Valinurov Radik , Denisenko Yuriy , Akhmetov Aydar , Gilmutdinov Irek , Seliverstova Natalya
Published: November 2020

In modern times, qualified athletes reached high level of physical fitness. That’s why, the greater increase in the volume and intensity of the training process becomes difficult task. The first step is to develop the search for new forms of the training process organization. They create optimal conditions for the full-value realization of the adaptive possibilities and the restoration of energy resources. Therefore, it is very important to search for fundamentally new means and methods to improve the physical performance of athletes. One of them is often power simulators, in which the resistance force is formed by a set of brakes that have significant inertia. However, special research and experience in sports practice indicate that the use of traditional strength training equipment, although it contributes to the development of strength quality. At the same time negatively affects the development of speed and endurance. The problem of finding new tools that cannot slow down the development of speed and endurance during the development of strength qualities remains urgent. Among the few tools of this kind, special attention should be paid to exercises that help improve the relaxation characteristics of the muscles. A number of studies showed the beneficial effect of special exercises that improve the relaxation characteristics (relaxation rate) of skeletal muscles, and contribute to improving the effectiveness of special physical performance and improving sports results.
Modeling of physical education in the e-learning system for the physical culture discipline
Authors: Rayzikh Artem , Rayzikh Andrey
Published: November 2020

At the present dynamic development of education, distance learning is increasingly popular due to its mobility and a variety of different information. There are certain difficulties in organizing the educational process using electronic educational resources. The article describes the modeling of the physical education process in non-sports institutes of Udmurt State University. The developed e-learning system at the University based on the Moodle platform allowed us to simulate the process of physical education and create an e-learning course based on it. The training course has a block system for organizing the physical education model. Using the e-learning system in the educational process of higher education allows to modernize the process of students’ physical education non-sports institutions, and lay a solid foundation for further self-education. This material is useful for University teachers who have an electronic educational environment.
Comparative analysis of hemodynamic parameters and heart rate variability in football and hockey players at the stage of sports improvement
Authors: Lavrichenko Vladislav , Lindt Tatiana , Kalinina Irina , Zolotarev Alexander
Published: November 2020

The article presents a multi-year multicenter research material concerning the study of adaptive aspects of hemodynamic and vegetative homeostasis of athletes engaged in football and hockey at the stage of sports improvement. The following was revealed: both groups of athletes were characterized by the formation of a cardiovascular functional system with a state of minimal tension of regulatory mechanisms to maintain hemodynamic homeostasis. The total sum of ICVR indicators in the group of football players was -1 point, which, according to the classification, can be assessed as a state of some functional tension, manifested by the mobilization of protective mechanisms. The hockey players were observed to have an optimal state of the regulation systems tension. It is characteristic of a satisfactory adaptation of the body to environmental conditions (1 point). The vascular type of self-regulation of blood circulation is more optimal in the formation of adaptation to dynamic loads of variable intensity.
Body weight composition and physical fitness of 17-18-year-old agricultural university students with different motor activity amounts
Authors: Blinkov Sergey , Levushkin Sergey , Kosikhin Victor
Published: November 2020

The article presents the comparative analysis results of body weight composition and physical fitness of 17-18-year-old students who are engaged in sports and not engaged in sports. Students with a higher volume of physical activity have a higher content of active cell mass, water in the body (by 1.62 % and 3.31%, respectively), a lower body mass index, and the content of total and visceral fat (by 1.59%, 4.98% and 1.44%, respectively). There is a high correlation with a higher level of physical fitness. For all seven motor tests that characterize the development of basic conditioning and coordination abilities, the indicators of athletes are higher. In general, 27.2 % of female athletes have an above-average level of physical fitness, the average level was found in 54.45 % and below the average in 18.18 %. It is significantly higher than the same indicators for non-sports students.
Synergetic concept of a highly qualified athlete’s socioculturization (in the issue raising order)
Authors: Popova Elena , Popova Anastasia , Bazelyuk Vladimir , Demin Aleksandr
Published: November 2020

The description and algorithmic representation of the highly qualified athlete’s synergetic concept, studying at a University of physical culture, socioculturization is presented in the article. Special attention is paid to the psychological and pedagogical foundations of an individual athlete, aspiring to individual leadership in the chosen sport value potential formation.
An ISFET sensor based on In2O3 nanoribbon for pH detection of micro solutions
Authors: Wu Chuanjian , Wang Yiqing , Yang Min
Published: November 2020

In this paper, an ISFET sensor based on In2O3 nanoribbon is developed for pH detection of micro solutions. A double channel ISFET is designed which includes the In2O3 nanoribbon top channel and silicon substrate bottom channel so as to realize the pH detection of the micro solutions. Through experiments, the sensitivity of the sensor is 70 mV/pH in the range of pH 6 to pH 10, which exceeds the Nernst limit of 59.2 mV/pH (300 K) at room temperature. Taking the detection of cTnI as an example, the pH sensor can be used to detect the concentration of biomarkers
Mobile robot positioning algorithm based on Kalman filtering method in network environment
Authors: Zhang Shuang
Published: November 2020

Positioning is the basic link in a multi-mobile robot control system, and is also a problem that must be solved before completing a specified task. The positioning method can be generally divided into relative positioning and absolute positioning. Absolute positioning method refers to that the robot calculates its current position by acquiring the reference information of some known positions in the outside world, calculating the relationship between itself and the reference information. Absolute positioning generally adopts methods based on beacons, environment map matching, and visual positioning. The relative positioning method mainly uses the inertial navigation system INS. The inertial navigation system directly fixes the inertial measurement unit composed of the gyroscope and the accelerometer to the target device, and uses the inertial devices such as the gyroscope and the accelerometer to measure the triaxial angular velocity and The three-axis acceleration information is measured and integrated, and the mobile robot coordinates are updated in real time. Combined with the initial inertial information of the target device, navigation information such as the attitude, speed, and position of the target device is obtained through integral operation [1-2]. The inertial navigation system does not depend on external information when it is working, and is not easily damaged by interference. As an autonomous navigation system, it has the advantages of high data update rate and high short-term positioning accuracy [3]. However, under the long-term operation of inertial navigation, due to the cumulative error of integration, the positioning accuracy is seriously degraded, so it is necessary to seek an external positioning method to correct its position information [4]
Kinematic Performance Analysis of a Controllable Mechanism Welding Robot with Joint Clearance
Authors: Gong Junjie , Wei Wei , Cai Ganwei , Liu Yixin , Peng Sixu
Published: November 2020

Because the motor and reducer of the conventional tandem welding robot are installed at the revolute joint, the robot has large rotational inertia and long residual vibration time. However, due to the limitation of workspace and other reasons, the current parallel robot is not suitable for all series welding robots. Therefore, based on the concept of "multi-degree-of-freedom controllable mechanism", a new controllable mechanism welding robot is proposed in this paper. The driving motor and reducer, which have great influence on the main and branch chain of the welding robot, are installed on the frame. The advantage of this design is that the inertia of the robot mechanism is significantly reduced, and its dynamic performance is improved. The position errors of the end members of the welding robot moving along the circle, as well as the angle errors of each joints under the circle movements are analysed.
Radiation protection practice of medical doctors of surgical and interventional specialties in Saudi Arabia
Authors: Alshumrani G.
Published: November 2020

This study aimed to evaluate the radiation protection practices of medical doctors of surgical and interventional specialties in different healthcare sectors of Saudi Arabia. A cross-sectional study of medical doctors in Saudi Arabia who utilize radiation to perform interventional procedures and surgical operations was conducted. Data were gathered about the basic demographic background of the respondents, their daily application of radiation protection, and variations among different specialties and institutions regarding radiation protection practices. A total of 182 responses were received from different specialties, including interventional radiology (22%), interventional cardiology (16.5%), orthopedic surgery (14.8%), urology (14.3%), and diagnostic radiology (12.1%). Responses were received from different healthcare sectors, including the Ministry of Health (47%), private sector (26%), and university hospitals (18%). Only 59% of the respondents reported applying the As Low As Reasonably Achievable (ALARA) principle of radiation protection. The specialties with the highest reported lack of the ALARA principle application were orthopedic surgery (89%), urology (69%) and endoscopy (57%). The highest reported non-adherence to the ALARA principle was in the Ministry of Defense hospitals (50%), private hospitals (44%) and Ministry of Health hospitals (43%). The use of a personal dosimeter was reported by 58% of the respondents and only 42% reported having training in radiation protection. The respondents reported a lack of regular checking of x-ray machines (28%) and protection aprons (40%), non-availability of radiation protection guidelines (48%), and a lack of policies for radiation dose monitoring (27%) in their institutions. It was concluded that the compliance with radiation protection practices was variable and generally poor among different specialties and healthcare sectors in Saudi Arabia. Similar poor practices were reported in the international literature of different countries. The concerned authorities worldwide are advised to take further actions in this regard.
Stationsäquivalente Behandlung
Authors: Längle Gerhard , Raschmann Svenja , Holzke Martin
Published: November 2020

In Deutschland herrscht nach wie vor eine strikte Sektorisierung der Versorgungslandschaft. Aufsuchende Akutbehandlung war bislang nur in Modellvorhaben realisiert und nicht bundesweit umsetzbar. Mit dem Inkrafttreten des Gesetzes zur Weiterentwicklung der Versorgung und Vergütung für psychiatrische und psychosomatische Leistungen (PsychVVG) im Jahr 2017, wurde diese Versorgungslücke mit der Stationsäquivalenten Behandlung (StäB) als neuartige Form aufsuchender Akutbehandlung gefüllt. In diesem Beitrag werden die für StäB relevanten rechtlichen Grundlagen und die in der Selbstverwaltung getroffenen Vereinbarungen gebündelt. Bisher bekannte Modelle der Finanzierung werden vorgestellt und der Umgang mit StäB aus Sicht der Krankenhausplanung wird dargelegt. Auch in der Kinder- und Jugendpsychiatrie ergänzt die stationsäquivalente Behandlung die Landschaft psychiatrischer Versorgungsangebote, weshalb deren besondere Anforderungen an die Behandlung im Zuge der StäB gesondert aufgegriffen werden. Aus aktuellem Anlass nimmt der Beitrag Bezug auf die Erfahrungen mit StäB in Zeiten der SARS-CoV-2 Pandemie. StäB wurde während sozialer Kontaktsperren und Quarantäne- und Hygienemaßnahmen an den verschiedenen Zentren unterschiedlich ausgestaltet. Allen gemeinsam waren die erforderlichen Anpassungen an die Hygiene- und Abstandsregelungen, welche nochmals komprimiert dargestellt werden.
Determinanten des subjektiven Rehabilitationsbedürfnisses und der Antragsintention bei Personen mit Rückenschmerzen
Authors: Schmitt Nadine , Fauser David , Golla André , Zimmer Julia-Marie , Bethge Matthias , Mau Wilfried
Published: November 2020

Ziel der Studie Bisher wurden v. a. Einflussfaktoren der Antragstellung und Inanspruchnahme der medizinischen Rehabilitation wegen Rückenschmerzen untersucht. Potentielle Vorstufen der Leistungsbeantragung – Rehabilitationsbedürfnis und Antragsintention – waren bislang weniger Forschungsgegenstand im Kontext des Rehabilitationszugangs bei Rückenschmerzen. Die Studie untersucht deshalb die Häufigkeit und Determinanten dieser beiden Vorstufen.

Methodik Die Daten entstammen einer durch die Deutsche Forschungsgemeinschaft geförderten Kohortenstudie von 45 000 Versicherten der Deutschen Rentenversicherungen Nord und Mitteldeutschland. In die Analysen der Querschnittsdaten zum ersten Befragungszeitpunkt wurden 45- bis 59-jährige Personen mit Rückenschmerzen in den letzten 3 Monaten, ohne Erwerbsminderungsrente und ohne medizinische Rehabilitation in den letzten 4 Jahren eingeschlossen. Determinanten des Rehabilitationsbedürfnisses bzw. der Antragsintention wurden in multivariaten logistischen Regressionsanalysen untersucht.

Ergebnisse Von 6549 Personen mit Rückenschmerzen sahen sich 2348 (36%) als rehabilitationsbedürftig. Hiervon beabsichtigten 774 (33%) einen Antrag auf medizinische Rehabilitation innerhalb der nächsten 12 Monate zu stellen. Bei beiden Zielgrößen bestanden starke Zusammenhänge mit der sozialen Unterstützung durch nahestehende Personen. Das Rehabilitationsbedürfnis wurde zusätzlich durch Vorerfahrungen mit medizinischer Rehabilitation determiniert. Der zweitwichtigste Einflussfaktor auf die Antragsintention war die Unterstützung seitens Ärzt/innen und Therapeut/innen. Weitere Einflussfaktoren wirkten unterschiedlich auf beide Zielgrößen.

Schlussfolgerung Um den bedarfsgerechten Rehabilitationszugang zu verbessern, sollten bereits seine Vorstufen, das subjektive Rehabilitationsbedürfnis und die Antragsintention, mit ihren z. T. unterschiedlichen Determinanten beachtet werden. Dabei ist die Unterstützung durch das private Umfeld sowie Ärzt/innen und Therapeut/innen von großer Bedeutung. Dies ist ein weiterer Hinweis darauf, dass die Information und Einbeziehung dieser Akteure wichtige Bausteine sind, um einen bedarfsgerechten Zugang zu gewährleisten.
Update Breast Cancer 2020 Part 3 – Early Breast Cancer
Authors: Huober Jens , Schneeweiss Andreas , Hartkopf Andreas D. , Müller Volkmar , Lux Michael P. , Janni Wolfgang , Ettl Johannes , Belleville Erik , Thill Marc , Fasching Peter A. , Kolberg Hans-Christian , Schulmeyer Carla E. , Welslau Manfred , Overkamp Friedrich , Tesch Hans , Fehm Tanja N. , Lüftner Diana , Schütz Florian , Wöckel Achim
Published: November 2020

The treatment of patients with early breast cancer has always been characterised by escalation by new therapies and de-escalation through identification of better treatment regimens or introduction of better tools to estimate prognosis. Efforts in some of these areas in the last few years have led to solid data. The results of the large studies of de-escalation through use of multi-gene tests are available, as are the results of some studies that investigated the new anti-HER2 substances T-DM1 and pertuzumab in the early treatment situation. Several large-scale studies examining the role of CDK4/6 inhibitors will soon be concluded so innovations can be anticipated in this area also. This review article will summarise and classify the results of the latest publications.
Not always eosinophilic esophagitis – intramural pseudodiverticulosis of the esophagus – a case report and literature review
Authors: Frieling Thomas , Kreysel Christian , Blank Michael , Mülle Dorothee , Euler Philipp , Melchior Ilka
Published: November 2020

Background Intramural pseudodiverticulosis of the esophagus (EIPD) is a rare disease leading to dysphagia, chest pain, and weight loss. The diagnosis is difficult, and the disease can be confounded with eosinophilic esophagitis (EoE). We present a patient with esophageal intramural pseudodiverticulosis and a literature review.

Case report The 45-year-old white caucasian woman with a history of nicotine and alcohol abuse had progressive hoarseness and severe dysphagia for solid food. Esophagogastroduodenoscopy (EGD) showed proximal esophageal stenosis, thrush esophagitis, and mucosal alteration with trachealization suspicious of EoE. However, repeated bouginage EGD and barium swallow revealed typical signs of esophageal intramural pseudodiverticulosis (EIPD). The patient was treated successfully by bougingage, acid suppression, and antifungal therapy. The literature analysis revealed the characteristics of EIPD according to age, sex, risk factors, and therapy modalities.

Conclusion The case report and the literature overview suggest that EIPD can be confounded with EoE.
Stability of Turoctocog Alfa, a Recombinant Factor VIII Product, during Continuous Infusion In Vitro
Authors: Takeyama Masahiro , Nøhr Anne Mette , Pollard Debra
Published: November 2020

Objective Turoctocog alfa is a recombinant factor VIII (rFVIII) for the prevention and treatment of bleeding in patients with hemophilia A, including those undergoing surgery and invasive medical procedures. This in vitro study evaluated the physical and chemical stability of turoctocog alfa during continuous infusion (CI) over 24 hours at 30°C.

Materials and Methods The study was performed at 30°C ( ± 2°C). A CI system with pump speed set at either 0.6 or 1.5 mL/h was used to evaluate the stability of three turoctocog alfa strengths (500, 1,000, and 3,000 IU), equating to doses of 1.1 to 16.1 IU/h per kilogram of body weight. The following parameters were evaluated at selected time points between 0 and 24 hours: appearance of solution, clarity, pH, potency, purity, content, total high molecular weight proteins (HMWPs), and oxidized rFVIII.

Results The mean potency of turoctocog alfa was maintained within the predefined acceptance criteria during CI for both pump speeds with all three strengths at 6, 12, or 24 hours (500 IU: ≥484 IU/vial; 1,000 IU: ≥1,014 IU/vial; and 3,000 IU: ≥3,029 IU/vial). Furthermore, the appearance of solution, clarity, pH, purity, content of turoctocog alfa, total HMWP, and oxidized forms were also within the predefined limits, and comparable to the reference samples (time = 0 hours) for the pump speeds and product strengths assessed.

Conclusion Physical and chemical stability of turoctocog alfa was maintained during CI over 24 hours. There was only minor degradation or changes in any of the parameters tested. Potency was within the prespecified acceptance limits throughout 24 hours of infusion. These findings confirm the suitability of turoctocog alfa for CI.
Outcomes of Delayed Sternal Closure in Paediatric Cardiac Surgical Patients–A Prospective Single Centre Study
Authors: Vaswani Prateek , Sahu Manoj Kumar , Bipin Challatil , Singh Sarvesh Pal , Rajashekar Palleti , Devagourou Velayoudam , Talwar Sachin
Published: November 2020

Background Delayed sternal closure (DSC) is being increasingly used as an interim support to help the dysfunctional heart in the road to recovery after complex pediatric cardiac surgeries. The purpose of this study was to assess the conduct of DSC at a tertiary care center.

Methods Between 2018 and 2019, 185 consecutive pediatric patients (below 12 years of age) underwent cardiac surgery at a tertiary care center. The incidence and causes of DSC were noted. The various pre, intra and postoperative factors till discharge or demise were noted and analyzed.

Results In this study, DSC was done in 63 patients (34.05%) with a median age and weight of 29 days (18–100 days) and 4 kg (2–12.3 kg), respectively. Transposition of great arteries (TGA) (41.27%) constituted the majority, followed by total anomalous pulmonary venous connection (TAPVC) (26.98%). Myocardial edema (49.21%) was the most common indication for DSC. Mean duration of open chest was 40.75 ± 18.58 hours. All-cause mortality was 19.05% (12/63). On multivariate analysis by logistic regression, the independent predictors of mortality were needed for preoperative mechanical ventilation (OR 42.82, 95% CI = 4.52–406.03, p < 0.001) and development of postoperative sepsis (OR 20.07, 95% CI = 2.12–189.80, p = 0.002).

Conclusions DSC is a safe and effective technique in the management of complex pediatric cardiac surgeries. It provides assistance to the severely dysfunctional myocardium soon after the surgery and helps in stabilization of hemodynamics with avoidance of postoperative mediastinal compression. Early sternal closure should be considered on the basis of cardiovascular function and/or resolution of primary indication for DSC.
14.12.3 Telluropyrylium and Benzotelluropyrylium Salts (Update 2020)
Authors: Tan Q.
Published: November 2020

This chapter is an update to the earlier Science of Synthesis contribution (Section 14.12) describing methods for the synthesis of telluropyrylium and benzotelluropyrylium salts. Recent interest in this area has mainly focused on the preparation of dyes containing telluropyrylium and dibenzotelluropyrylium units.
14.4.19 9H-Xanthen-9-ones (Update 2020)
Authors: Gao W.-C. , Tian J.
Published: November 2020

This chapter is an update to the earlier Science of Synthesis contribution (Section 14.4.10) describing methods for the synthesis of 9H-xanthen-9-ones. The methods come from the literature published in the period 2003–2019.
Development of a flux-film-coated sputtering (FFC-sputtering) method for fabricating c-axis oriented AlN film
Authors: Song Y. , Kawamura F. , Shimamura K. , Ohgaki T. , Ohashi N.
Published: November 2020

In this study, we developed a novel growth method named “Flux-Film-Coated (FFC) sputtering.” In this method, nitrogen radicals were supplied to the Al–Sn flux at around 600 °C followed by the deposition of an Al–Sn metal film on a sapphire substrate as flux, which resulted in the growth of high-quality AlN films. The nitrogen radical, which is the source of nitrogen for the growth of AlN, was generated by the radio frequency plasma in a nitrogen atmosphere. Using a zirconia target in the plasma generation process, nitrogen radicals were easily generated because the zirconia was not etched in a pure nitrogen atmosphere, which enabled us to fabricate the AlN film using the flux method in the sputtering chamber in a single step. The crystallinity of the synthesized AlN determined using the FFC-sputtering method was remarkably improved when compared with that of the AlN film deposited using the reactive sputtering method.
Summary & Notes
Authors: Nelson Jane Bray , Nelson Jim
Published: November 2020

Summary and notes for Teaching About Kinematics: An AAPT/PTRA Resource.
Exploratory Exercises
Authors: Kallard T.
Published: November 2020

Color. The helium-neon laser generates an intense output of red light at the wavelength of 632.8 nanometers (nm). In addition to the red laser light, the helium of the laser produces some incoherent blue and green light.
Scanning a Focused Light Beam Over a Wide Flat Field
Authors: Kallard T.
Published: November 2020

Two front surface mirrors are positioned to intercept the input laser beam and to scan it over field AB. Lens L is positioned in the beam’s path and focuses the beam on a screen or recording medium. Mirrors M1 and M2 are oscillating or continuously rotating in a synchronized manner but the speed of rotation of M1 is double that of M2. The axis of rotation of M1 is equidistant from that of M2 and the center of lens L.
Refractive Index Measurements
Authors: Kallard T.
Published: November 2020

The outline of the glass block is drawn on a piece of graph paper which rests on the lazy susan turntable (see Fig. 75).
Direct Shadow Demonstration (Shadowgraphy)
Authors: Kallard T.
Published: November 2020

This demonstration illustrates a simple ray optic method by which very small changes in the refractive index of air can be made visible. This method of investigating the flow of gases is widely used in the study of ballistics and in aeronautical and combustion engineering.
Laser Beam Generates Conic Sections
Authors: Kallard T.
Published: November 2020

Conography is a new space-age technology which uses conic curves to digitize and store graphic and symbolic information. The sections of a right circular cone (cone sections) are: a) circle, b) ellipse, c) parabola, d) hyperbola. The following exercise shows a method of generating conic sections (or simply “conics”) with a laser beam (see Fig. 84).
Nematic Liquid Crystal Polarization Rotator and Depolarizer
Authors: Kallard T.
Published: November 2020

Conventionally, half-wave retardation plates are used to rotate the plane of polarization through an arbitrary angle. The use of a half-wave plate is limited to the wavelength for which it was manufactured.
Interference and Interferometers
Authors: Kallard T.
Published: November 2020

If light from a source is divided by suitable apparatus into two or more beams which are then superposed, the intensity in the region of superposition is found to vary from point to point. There will be maxima, which exceed the sum of the intensities in the beams, and minima which may be zero. This phenomenon is called optical interference. Interference cannot occur unless the beams are coherent with respect to each other. In the laser we have a very bright source of extremely coherent light.
Interferometer for Measuring Parallelism and Small Wedge Angles
Authors: Kallard T.
Published: November 2020

A simple, easy to use technique is described below for measuring the degree of plane parallelism of two polished surfaces of a transparent material. In this method the displacement of a circular system of two-beam non-localized interference fringe pattern is used to give a direct measure of the parallelism of two surfaces. Wedge angles of a few minutes down to a few seconds of arc can be measured.
Newton’s Rings Demonstration
Authors: Kallard T.
Published: November 2020

Newton’s rings provide the classic illustration of thin film interference of the Fizeau type.

If a shallow convex spherical surface is placed on an optical flat, a system of circular fringes is seen around the point of contact. These are Newton’s rings. The fringes (light or dark) are lines of constant separation between the surfaces. The spacing difference between two adjacent fringes is one-half wavelength of the illuminating light. Thus, the fringe pattern seen can be considered as a contour map of the space between the two surfaces. The ring system is also seen with transmitted light but with a much smaller contrast. These rings are exactly complementary to the reflected ring system.
Thickness Measurement by Interference
Authors: Kallard T.
Published: November 2020

If a transparent wedge of small angle, placed in air, is illuminated with laser light, an interference pattern is created. This pattern consists of a number of straight-line, equidistant fringes, called “lines of equal thickness.”
Vibration Detection Using Laser Speckle
Authors: Kallard T.
Published: November 2020

A filtered and diverging laser beam illuminates the surface of a diffusely reflecting, vibrating surface.
Speckle-shearing Interferometry
Authors: Kallard T.
Published: November 2020

Speckle interferometry involves making a high-resolution double-exposure photograph of an object which is illuminated with coherent light. It is a simple method for measuring displacements. Since the approach is purely optical, there is no physical contact with the specimen. The fringes which depict the derivatives of displacements of the specimen are made visible by spatial filtering technique.
Self-imaging Without Lenses (Fourier Imaging)
Authors: Kallard T.
Published: November 2020

An optical image is the reproduction of an object formed by an optical system. An illuminated object is considered to be composed of an infinite number of adjacent points of light, each of which emits secondary radiation. Conventional optical systems employ a lens to convert the diverging radiation into a converging beam which intersects to form an image of the original object point. Other techniques usually employed would be dependent on interference techniques such as diffraction or self-imaging.
Optical Simulation of the Electron Microscope
Authors: Kallard T.
Published: November 2020

The sketch below illustrates the experimental setup which simulates an electron microscope (EM) imaging a two-dimensional lattice. The same setup can also be used to demonstrate x-ray diffraction effects.
Optical Method for Producing Zone Plates
Authors: Kallard T.
Published: November 2020

The classical Fresnel zone plate, with its alternate opaque and transparent zones, acts as a lens with diffraction rather than refraction serving to deviate the light rays. The Fresnel zone plate is an unusual lens, however, in that it possesses multiple foci and also because it behaves simultaneously as a diverging and a converging lens.
Low-budget Holography
Authors: Kallard T.
Published: November 2020

Contrary to general belief, holograms are not difficult to make and the equipment need not be expensive.
Physics Teaching at Harvard Fifty Years Ago
Authors: Hall Edwin H.
Published: November 2020

The letter of Professor Webster informing me that a committee of which he is chairman had taken action proposing the award which has just been made caused me varied emotions. I was utterly surprised. I was pleased also, of course, for one is never too old to appreciate a compliment, and I regarded this as a very great compliment, a great honor, for which I now thank everyone who has had any part in conferring it. But I could not help having an uneasy feeling that there was some mistake about it, and if I had presently received a second letter or a telegram explaining that someone had blundered and asking me to forget all about the matter, I should have felt less surprised, and less pleased, than I was by the first letter.
RESPONSE
Authors: Crew Henry
Published: November 2020

Galileo has often been called the “Father of Physics,” and those of us who instruct in the field that he sired acknowledge increasingly our debt to the great investigator and experimenter of Pisa, Padua, and Florence. Today, in presenting the Oersted Medal of this Association, we seek to do honor to the “Father of Galileo”—Professor Henry Crew, of North-western University, who through his translation into English of Galileo’s Dialogues concerning two new sciences has done much to bring the works of that doughty pioneer of physics within the reach of us all, and whose long career as a teacher and writer has been an inspiration to many. This man who has contributed steadily to our field of learning over a period of more than 50 years has left many guideposts along his way that “he who runs may read,” and some of these have become permanent landmarks in the field. Professor Crew’s writings have run the gamut from high school textbooks and laboratory manuals to the translations of medieval Latin documents on optics, and they show a depth of scholarship coupled with elegance of style that bespeak the quality of broad classical training that is all too rare in our contemporary streamlined education.
Some Reminiscences of My Teaching Career
Authors: Sommerfeld A.
Published: November 2020

Each year since 1936 the American Association of Physics Teachers, acting through its established committee apparatus, has chosen a physicist deemed to have contributed notably to the teaching of physics, and has sought to do him honor by a public award. This custom has been made possible by the generosity of two of the Association’s members. We have come now to the pleasant annual ceremonial through which this award, the Oersted medal and certificate, are bestowed.
Metaphysics of a Physics Teacher
Authors: Wall C. N.
Published: November 2020

I wish to express my deep gratitude for the honor of being awarded the Oersted Medal. In accepting this award, I can do so in good conscience only if I regard the honor as a reflection on the good works of my former physics students. But I have long felt that the greatest honor should go, not to the recipient of the Oersted Medal, but to the few men of imagination who first conceived the idea of an Association of Physics Teachers and an award for good teaching.
Presentation of Mark W. Zemansky as 1956 Oersted Medalist
Authors: Palmer R. Ronald
Published: November 2020

The Oersted Medal of the American Association of Physics Teachers is awarded annually for “notable contributions to the teaching of physics.” The 1956 medal will be presented at this time to Mark W. Zemansky, Professor of Physics at City College, New York City. This, the twenty-first annual award, maintains a tradition which has gained strength and significance as the roster of names of distinguished medalists has grown.
Francis Weston Sears: Oersted Medalist for 1961
Authors: Olsen Leonard O.
Published: November 2020

The Awards Committee of the American Association of Physics Teachers found its assignment most pleasant and its task exceptionally light. At our summer meeting, I reported to the Committee that an unusual number of our members had written to urge the nomination of Francis Sears. We have ignored the protests of our fellow committeeman, Professor Sears, and the rest of us thus unanimously present Dr. Francis Weston Sears for the Oersted Medal, the highest award of the American Association of Physics Teachers.
Oersted Medal Award Ceremony: 1965
Authors: Morrison Philip
Published: November 2020

Among the great names by which we call units, Oersted’s is the most appropriate for showing a concern with teaching, since his discovery was made during the very course of a lecture. All of us have treasured that happy tale for a long time. It seems that Röntgen, too, might qualify. His work began when he noticed fluorescence, not, to be sure, during a lecture, but while getting ready for one. I doubt that any Ω-resonance will ever be found in the teaching context, though it might be that some extremely generous demonstrator might have discovered, say, the persistent superfluid current while preparing for his show. But there is no dodging it; physics is simply more sophisticated today.
Science and Progress
Authors: Phillips Melba
Published: November 2020

It is indeed a great honor to receive the Oersted Medal, and I thank you, Professor Ford, and the Awards Committee. I am going to take advantage of having lived to be an old timer to thank one other person, Paul E. Klopsteg, without whom there would be no such award. Not only no award, but very likely no AAPT. According to Professor Homer Dodge, who was the first president of the American Association of Physics Teachers, “The tap root of the Association was the insistent interest in teaching that has characterized Dr. Paul Klopsteg.” Professor Dodge traces this insistence as far back as 1916, although the AAPT was not founded until 1930. The annual award for teaching was established by Dr. Klopsteg in 1934. I am grateful for having come to know Paul Klopsteg a little while I lived in Chicago, to share his ongoing interest in AAPT. It has also been a pleasure to admire a few of the opals he has cut and polished so beautifully; and to enjoy (as an outsider to the sport of archery) his papers on the physics of the bow and arrow, a specialty he has pursued in addition to more conventional physics.
Response of the Oersted Medalist
Authors: Crane H. Richard
Published: November 2020

I am indeed greatly pleased and honored to receive the Oersted Medal. I think my reaction on being informed of this may have been typical: What in the deuce will I say that is in line with the purpose of the award? I assume the response ought to have something to do with physics education, since the honor is bestowed by the AAPT. Also, I have been told quite firmly that it should be more than a thank you. So for the next few minutes I will take advantage of this captive audience and make a few comments on problems that I have found intriguing over a long period, and whose solutions seem always to be just around the next corner. The kind of problem that is going to be solved the next time around seems to attract teachers in physics, gold miners, compulsive gamblers, and others, and I guess I am no exception. I have tried a lot of things, but for the most part, to quote our fellow scientist Omar, “Ever I came out by the same door where in I went.” At any rate, I’ll share a few thoughts with you, and if this “response” needs a subtitle, it might be, in current phraseology, “The Real World Connection.”
The Brigalow Catchment Study: V*. Clearing and burning brigalow (Acacia harpophylla) in Queensland, Australia, temporarily increases surface soil fertility prior to nutrient decline under cropping or grazing
Authors: Thornton C. M. , Shrestha K.
Published: November 2020

In the Brigalow Belt bioregion of Australia, clearing of brigalow (Acacia harpophylla) scrub vegetation for agriculture has altered nutrient cycling over millions of hectares. In order to quantify the effect of this vegetation clearing and land use change on soil fertility, the Brigalow Catchment Study commenced in 1965. Initial clearing and burning of brigalow scrub resulted in a temporary increase of mineral nitrogen, total and available phosphorus, total and exchangeable potassium and total sulfur in the surface soil (0–0.1 m) as a result of soil heating and the ash bed effect. Soil pH also increased, but did not peak immediately after burning. Soil fertility declined significantly over the subsequent 32 years. Under cropping, organic carbon declined by 46%, total nitrogen by 55%, total phosphorus by 29%, bicarbonate-extractable phosphorus by 54%, acid-extractable phosphorus by 59%, total sulfur by 49%, total potassium by 9% and exchangeable potassium by 63% from post-burn, pre-cropping concentrations. Fertility also declined under grazing but in a different pattern to that observed under cropping. Organic carbon showed clear fluctuation but it was not until the natural variation in soil fertility over time was separated from the anthropogenic effects of land use change that a significant decline was observed. Total nitrogen declined by 22%. Total phosphorus declined by 14%, equating to only half of the decline under cropping. Bicarbonate-extractable phosphorus declined by 64% and acid-extractable phosphorus by 66%; both greater than the decline observed under cropping. Total sulfur declined by 23%; less than half of the decline under cropping. A similar decline in total potassium was observed under both land uses, with a 10% decline under grazing. Exchangeable potassium declined by 59%. The primary mechanism of nutrient loss depended on the specific land use and nutrient in question.
Self-supported nickel sulfide derived from nickel foam for hydrogen evolution and oxygen evolution reaction: effect of crystal phase switching
Authors: Yang Wenshu , Wang Shuaishuai , Luo Wei , Li Longhua , Hao Jinhui , Shi Weidong
Published: November 2020

Designing and fabricating economically viable, high active and stable electrocatalysts play an important role for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Crystal phase is the crucial factor that governs the electrochemical property and electrocatalytic reaction pathways. Here, a one-step nickel foam derived sulfidation method was presented to synthesize self-supported NiS2 and Ni3S2. The crystal phase-dependent chemical properties related to electrocatalytic behavior were evaluated by a series of advanced characterization and density functional theory calculations. Overall, the self-supported Ni3S2 shows high electrochemical activity towards both HER and OER in alkaline conditions, which afford the current density of 10 mA cm−2 with overpotentials of 245 mV for OER and 123 mV for HER, respectively. When employed the self-supported Ni3S2 as the bifunctional electrocatalysts for overall water splitting, the entire device provides the current density of 10 mA cm−2 at 1.61 V. These results indicate that the electrocatalytic properties can be exert greater improved by controlling the crystal phase, offering the prospect for advanced materials design and development.