bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of psychological features of anxiety in adolescents and youth in school and university
Authors: Kolyagina Victoria , Yadrov Konstantin , Golubovich Slavitsa , Chebryakova Anastasia , Mityanets Serafima
Published: December 2020

The actual topic of modern psychology is the psychological health of students and youth. In further socialization and adaptation in society, a major role is played by the absence of anxiety in the psychological characteristics of children. It is very important that the future generation enters adulthood without a neurotic history. Therefore, the study of the characteristics of the manifestation of anxiety at school and university, its types and specific manifestations is one of the main aspects of the study of modern psychological science. The purpose of the paper is to consider the characteristics of the manifestation of anxiety in students of the fifth, ninth grades and students of the last courses of university. Materials and methods. The paper analyzes the types of anxiety of schoolchildren and students, the features of its manifestation in various age and gender groups. The study was conducted using psychological tests to identify the dependence of the level of anxiety on gender, age and the influence of the external environment. The research data were processed using mathematical statistics. The results of the study. A study of the manifestation of anxiety features showed that the school anxiety decreases and interpersonal anxiety increases with age. The data indicate the specificity in the gender characteristics of the manifestation of anxiety. High indicators of anxiety show the need to create special conditions for the upbringing and education of children in educational institutions to prevent it and reduce the level of neuroticism in schoolchildren and students. Discussion and conclusions. The results of the study can be useful to teachers, psychologists, and teachers for understanding the psychological component of the development of schoolchildren and students, for their further successful psychological maturation.
Positive psychology in students’ axiological choice situations
Authors: Brizhak Zinaida , Kolesina Karina , Mironenkova Natalya
Published: December 2020

The authors define axiological choice as a touch point between the culture senses and the student’s senses. This touch enables to transform students’ sense predilection. However, according to the multiple nature and character of choice, the latter has a negative side, which is sacrificing one alternative in favor of some other one. Hence it makes sense to apply the positive psychology concept in modelling students’ axiological choice situations. Positive psychology technologies and strategies lend “positive” support in decision making, as well as give a spirit of optimism and confidence in learning activities. This generally facilitates creative abilities and unleashes the personal potential. The article describes the role played by both positive and negative emotions. High concentration of negative emotions erects a communication and sense barrier disturbing sense transaction in learning activities, thus hindering conditions for its development. Defined are positive psychotherapy techniques aimed at the solution of an inner conflict in choice, these techniques are: distancing from the conflict, consideration of the conflict, situational approval, verbalization, enhancement of life goals. The above techniques possess a significant sense potential within the training process in modelling students’ axiological choice situations.
Significance of emotional intelligence for the innovative higher school teachers readiness for a person-centered interaction
Authors: Berberyan Asya
Published: December 2020

The article examines actual problems of the strategy of the educational process in the aspect of humanization of education, which should be based on genuine self-regulation and active self-determination of the student's personality. Inthecontextof the humanistic paradigm of the educational system, an individual approach to students, encouraging the disclosure of personal potential and creative development, the possibility of emotional contact with students are investigated. The purpose of the article is to study the relationship between the innovative readiness of higher education teachers and emotional intelligence. The methodological basis of the research are the works of such researchers in the field of a personality-centered approach to education as K. Rogers, I.V. Abakumova, I.S. Yakimanskaya, V.V. Serikov, E.V. Bondarevskaya, M.A., Andreev V.I. and others, as well as conceptual provisions in the field of emotional intelligence of scientists (J. Meyer, P. Salovey and D. Caruso R. Bar-On and D. Goleman N. Hall). We have chosen as research methods: diagnostics of "emotional intelligence" (N.Hall); questionnaire to identify the level of innovative readiness for personality-centered interaction of university teachers (author's methodology). As a result of the conducted empirical research, the hypothesis put forward by us about the presence of a positive correlation between emotional intelligence and the innovative indicator of the ability for person-centered interaction of higher school teachers was confirmed.
Features of the mentality of generations X, Y, Z
Authors: Pishchik Vlada
Published: December 2020

The article presents a comparative study of the mentality of generations X, Y, Z. The following approaches to the study of mentality are considered: historical, psychogenetic, psycho-physiological, socio-cultural, informational. The socio-psychological approach is recognized as the most significant in comparative research of generations. Generations are carriers of a unique mentality. We have identified four types of mentality: traditional, transitional, innovative, and post-innovative. The structure of the mentality includes: archetypes, image of the world, way of life, styles of thinking, relationships, and interaction of generations. We assume that statistical differences will be found in the components of the mentality of generations. the study involved: 150 schoolchildren from the city of Azov; 210 students and young workers; and 245 working adults from the city of Rostov-on-Don. We used techniques: technique of generational identity; the technique determined the type of mentality. The results showed that mature people identified with the transition generation, students with the information generation, and schoolchildren with the new generation. In the mentality of the transitional generation, archetypes, relationships are traditional; the image of the world, the style of thinking and interaction are in innovation. In the mentality of the information generation, archetypes, image of the world, lifestyle and interaction are in the innovation zone; style of thinking and attitudes in the post-innovation zone. In the mentality of the new generation, the image of the world, lifestyle, style of thinking, interaction are in the innovation zone; archetypes in the transition zone, and relationships in the tradition.
The role of perceptual attitudes of managers in the cognition of employees of the organization
Authors: Belousova Alla , Kozhukhar Galina , Vyshkvyrkina Maria , Ermak Vladislav
Published: December 2020

The article discusses the features of perceptual attitudes in the process of cognition of employees of the organization. Evaluation is understood as a manifestation of the evaluative component of thinking about another, and the perceptual attitude as a person's predisposition to perceive, act and evaluate the subject of interpersonal interaction in a certain way. The features of understanding evaluations in modern psychology are revealed, and the role of the evaluation component in thinking about another person is shown. The article presents socio-demographic professional factors that influence the formation of both employee and employee evaluations by the Manager. The main results of the study are described, indicating that the nature of self-esteem (overestimated or underestimated self-esteem) and the perceptual attitudes of the Manager determine the General trend of employee reflection. The identified trends and features of interpersonal cognition, the preservation of which is provided by setting mechanisms, reflect the attitude to individual qualities that managers have formed in the process of joint activities in terms of their significance for the implementation of the goals of the activity. However, changes in the goals of activities also lead to changes in the direction and nature of assessments from the outside.
Coping strategies and perceived stress in Russian army conscripts
Authors: Ulyanova Natalya , Pravdina Lida , Maximets Sergey
Published: December 2020

The article is devoted to the search for effective patterns of coping with stress in conscripts in different branches of Russian armed forces. The article presents the results of an empirical study of the relationship between coping strategies and the perceived traumatic stress of conscripts (N = 118) serving in the Aerospace, Railway and Air Defense units of the ground forces. Significant differences in indicators of perceived stress and coping among conscripts serving in different types of troops, associated with differences in the conditions of their professional activity, are shown. Multivariate regression analysis revealed the existence of specific coping patterns that involve the rejection of ineffective strategies and the use of effective ones. It is shown that these patterns are not universal, i.e. the effectiveness of the chosen coping strategies differs among ordinary soldiers serving in different branches of the armed forces. Conclusions are drawn about the need to take into account the peculiarities of military service in specific types of units when training and psychological support of conscripts in ways of effective adaptation to the conditions of military service.
Self-esteem of the ambition of Russian and Turkmen students
Authors: Barsukova Oksana , Scherbina Elena , Mozgovaya Natalia , Zhulina Galina , Shestopalopa Olesya
Published: December 2020

The article presents the results of a cross-cultural study of self-assessment of ambition of Russian and Turkmen students. The purpose of the study is to identify the features of self-esteem of ambition and the degree of its expression among students from different countries. The research was carried out using the questionnaire "Ambition" (OV Barsukova). The study involved 166 students aged 17-19 years: 94 Russian students and 72 Turkmen students. The majority of Russian students consider themselves to be more ambitious than ambitious people (48.94%), about a quarter of Russian students consider themselves to be unambitious people (25.53%), and a fifth - more un ambitious than ambitious people (21.28%) ), the minimum number - by undemanding people (4.26%). Most of the Russian students rate their ambition as moderate (51.056%), the minimum part of the students - as low (12.77%). On the whole, Russian students consider themselves ambitious rather than undemanding people and rate their ambition as moderate. The overwhelming majority of Turkmen students consider themselves to be ambitious people (83.33%), an insignificant part of students consider themselves to be more ambitious people than unambitious (11.11%) and undemanding people (5.56%). The majority of Turkmen students rate their ambition as high (61.11%), just over a quarter of them - as low (27.78%), the minimum number - as moderate (11.11%). In general, Turkmen students consider themselves ambitious and rate their ambition as high. A comparative analysis of the self-esteem of the ambition of Russian and Turkmen students was revealed according to the following indicators: the assessment of oneself as ambitious people prevails among Turkmen students, the assessment of oneself as people who are more ambitious than undemanding people prevails among Russian students, and the assessment of their ambition as moderate prevails among Russian students.
Models of information behavior: changes in psychological boundaries of internet users
Authors: Abakumova Irina , Grishina Anastasia , Zvezdina Galina , Zvezdina Ekaterina , Dyakova Elena
Published: December 2020

The authors conducted a study aimed at studying the characteristics of students with different models of information behavior in connection with the changes in psychological boundaries when using Internet technologies. The article reveals the role of information technologies and technical means, which become an important component of the life of a modern person and change his living space. The authors show the influence of information technologies on mental processes and relationships of people and consider the features of information behavior in connection with possible violation of psychological boundaries when using technical means The article analyses the problem of diagnosing information behavior and contains an overview of diagnostic methods of studying Internet addiction. It’s shown that in modern world information behavior is needed to be studied outside the context of addictive behavior. In the empirical part of the study authors distinguish the models of information behavior: entertaining, informational, communicative, productive and pragmatic. The empirical study defines the main behavioral characteristics of the presented information behavior models and investigate the changes in psychological boundaries when using the Internet among students with different models of information behavior. The results of the study allow to reveal the subjective attitude of students to the possibilities and availability of Internet resources in connection with differences in the severity of the expansion of psychological boundaries in communication, in the reflection of violation of boundaries, in changing needs.
Love as a linguacultural space (on the basis of paroemias in the English, Welsh, Gaelic and Scots languages)
Authors: Yevgrafova Yuliya , Gorbacheva Olga , Skripnik Kseniya , Fedorovich Olga
Published: December 2020

The present work explores the feeling of love in linguistic world pictures of different ethnic groups that comprise a single nation. The authors attempted to describe this feeling as a linguacultural space and define its aspects, both universal and nationally specific. The methodology of the research encompassed a comparative method, continuous sampling method, method of structural and semantic analysis and method of contextual analysis. The paper offers the analysis of paroemiological units in English, Welsh, Scottish Gaelic and Scots languages. Qualitative and quantitative characteristics of representation of the concept of Love were defined. Semantic structure of this word was revealed. There were described nationally specific features of representation of “man’s” matter when structuring Love within the framework of linguistic culture in the linguistic world picture. As the result of the study, a generalized scheme of the linguacultural space of Love is revealed at the level of a nation’s linguistic picture of the world, and the idioethnic one at the level of an individual ethnic group. Certain standards and stereotypes contained in this linguacultural space are distinguished as well.
Alien reality in source text and its reflection in translation
Authors: Khukhuni Georgiy , Vekovishcheva Svetlana , Pugina Elena , Kholstinina Tatyana
Published: December 2020

The present paper considers and analyzes one of the most controversial problems of theory and practice of literary translation. This problem is associated with the use and representation in a target text of lexical and phraseological units designating concepts or phenomena that are alien to a particular language and/or culture, within the framework of which the text is composed. Special attention is payed to the issue of the so-called foreignness of a concept for a primary and secondary audience, which stems from the difference in background knowledge of members of each audience in regard to the reality described in a book. The material for the study were fiction works of British writers of the 19th – the first half of the 20th centuries, as well as of Indian authors who either initially wrote in English or translated their own works into English, which was conditioned by the following aspects: 1. The existence of a plethora of colonies, people’s life in which attracted the attention of a significant number of English writers; 2. The diverse nature of the lexical and phraseological layer loaned from other languages; 3. The existence of author's translations into English of those pieces of writing that were initially written in languages of colonized peoples, as well as of original books initially written in English by local authors. 4. A long-term practice of translating such texts into Russian that increases the relevance of the research into means and methods applied for conveying such culture specific concepts. The paper uses methods of philological analysis of an original text and its translation, as well as methods of their comparative study. These methods allow estimating the appropriateness and equivalence of cross-lingual communication.
Tools of distance learning educational process at an Engineering University
Authors: Maksimenko L. , Korobova O. , Kalyuzhin V. , Ivantcivskaya N. , Makarikhina I.
Published: December 2020

The article discusses ways to organize the work of students and teachers in remote work mode. The high efficiency of the point-rating system (PRS) for evaluating independent work in the conditions of distance learning is shown. A study was conducted on the preparation of training and monitoring activities for online classes. The issues of organizing lectures and laboratory classes, as well as conducting training practice during the period of remote work are considered. Internet opens up wide opportunities in the process of electronic textbooks on humanitarian disciplines creating. The technologies’ specifics allow making direct links to resources located in the worldwide network. Many experts believe that Internet technology is a revolutionary breakthrough, surpassing the importance of a personal computer appearance. Currently, there is a significant increase in the share of test passing in remote mode. For the development of electronic tests, there are many software tools that allow you to develop them according to a teacher preference. The important selection criteria are accessibility, the ease of use, the absence of any additional knowledge and skills, as well as the utmost clarity and comprehensibility of the proposed actions
Training of professional and personal development of a manager as a multifunctional psychological practice
Authors: Kriulina Alexandra
Published: December 2020

Training of professional and personal development of a Manager is analyzed as a multifunctional psychological practice. A brief history of changing the status of training in Russia and the attitude of scientists to it is presented. Practical, theoretical and methodological substantiation of the author's point of view on training as a special kind of psychological practice is given. The main functions of the training are described in detail: psychotherapeutic, motivational, developmental, diagnostic, learning. The functions are described using examples from the specific practice of conducting training with adult business school students who have the status of a Manager in their professional field. An original form of determining the quality of managers ' training using training is proposed: development and description of a personal program of personal and professional development for the next two years. The perspective of training research as a psychological practice is outlined.
Quality of education as a requirement of modern society
Authors: Demina Vera , Demina Svetlana , Kozhukalova Oksana , Zayakina Irina
Published: December 2020

The aim of the work is to study the compliance of the quality of education in Russia with the requirements determined by the needs of the Russian society. The article reveals the genesis of such categories as" quality of education "and"quality of products and services". The features of educational services as a public good in the forms of market relations are revealed. The structure and role of various consumers of educational services are defined separately, and a classification of the needs and requirements of consumers to the quality of education is proposed. In the course of the research, such methods as analysis and synthesis, induction and deduction, and statistical methods for studying the economic situation were used. The empirical base of the research is scientific works of Russian and foreign authors on the problems of education quality, National standards of the Russian Federation and International standards in the field of quality, the Federal law "on education in the Russian Federation", Federal state educational standards of the Russian Federation, official data of the Federal Treasury and the Federal state statistics service of the Russian Federation.
Psychological aspects of ensuring the efficiency of professional activity of a project engineers
Authors: Khokhlina Оlena , Pomytkina Lubov , Yakovytska Lada , Lych Oksana , Khokhlin Denys
Published: December 2020

The article presents the results of theoretical and empirical research of the problem of psychological aspects of ensuring the efficiency of professional activity of a Project Engineers in the context of the theory of general and special abilities, the need to take into account the general and individual-typological in the mental development of the subject of labor. The importance of considering professional skills in connection with the intellectual readiness of the subject to the activity and individual style of its implementation is theoretically substantiated. The empirical study revealed the presence of correlations between the efficiency of professional activity, psychological readiness and individual style of activity. The most referent in the description of the professional skills of project engineers are the time of labor tasks performance and individual style of activity, and the organizing factor in the unity of these indicators is the generalization of mental activity, which forms the core of intellectual readiness for work. Correlation analysis of the data allowed us to identify the presence of clear links between: 1) the efficiency of activity by time indicator and ISA: the more ISA corresponds to the reference method, the less time is spent on solving the labor task, and vice versa; 2) between ISA and intellectual readiness for activity; the higher the level of complexity of labor tasks, the higher the level of correlation between these phenomena.
Optical properties in the visible range of two different India ink used as biological phantoms
Authors: Shahin Ali , Bachir Wesam , El-Daher Moustafa Sayem
Published: December 2020

The optical characteristics of two different brands of India ink, Parker Quink and Pelikan, as an absorber used in preparation a tissue-simulating phantom, have been investigated at visible wavelength range. For this purpose, a single integrating sphere system and a spectrophotometric transmission spectroscopy have been used to estimate the radiometric characteristics. Then, inverse adding-doubling algorithm was implemented to retrieve the optical coefficients of pure ink samples. Parker ink's absorption behavior turned out to incompatible with Pelikan over the present wavelength range. Furthermore, scattering property of both two brands has been exhibited and the albedo was calculated. Parker albedo showed a decremental behavior with wavelength and varied between 0.381 and 0.13. A structural profile of albedo was found for Pelikan, which varied between 0.366 and 0.03. This discrepancy might be explained by the variety of two brands composition besides experimental errors. Furthermore, Parker ink absorption variation turned out to be in correspondence to several tissues' absorption feature over broad wavelength ranges. Finally, Parker ink could be regarded as a better candidate to mimic absorption property for several tissues.
Achieving uniform thread load distribution in bolted joints using different pitch values
Authors: Coria Ibai , Abasolo Mikel , Gutiérrez Aitor , Aguirrebeitia Josu
Published: December 2020

Bolted joints are a critical component of machines and structures under cyclic loading. Bolt fatigue failure usually takes place in the first engaged thread for being the most loaded one. In this sense, a uniform thread load distribution improves its mechanical response and consequently the reliability of the joint. For this purpose, different thread pitch values can be used in the bolt and the nut, and there is an optimum value that leads to the most uniform load distribution for each particular joint configuration (geometry, preload level, materials and boundary conditions). Sopwith developed an analytical model to calculate this value, but no validation was carried out. This work presents a semianalytical model to estimate the load distribution for any differential thread spacing, which can also be used to calculate the optimum value. The results of this model are nearly coincident with Finite Element results and more accurate than those obtained from Sopwith model.
Nonlinear stability analysis of a spinning top with an interior liquid-filled cavity
Authors: Galdi Giovanni P. , Mazzone Giusy
Published: December 2020

Consider the motion of the coupled system, 𝒮, constituted by a (non-necessarily symmetric) top, ℬ, with an interior cavity, 𝒞, filled up with a Navier-Stokes liquid, ℒ. A particular steady-state motion [see formula in PDF] (say) of 𝒮, is when ℒ is at rest with respect to ℬ, and 𝒮, as a whole rigid body, spins with a constant angular velocity [see formula in PDF] around a vertical axis passing through its center of massGin its highest position (upright spinning top). We then provide a complete characterization of the nonlinear stability of [see formula in PDF] by showing, roughly speaking, that [see formula in PDF] is stable if and only if [see formula in PDF] is sufficiently large, all other physical parameters being fixed. Moreover we show that, unlike the case when 𝒞 is empty, under the above stability conditions, the top will eventually return to the unperturbed upright configuration.
Dienylation of Unfunctionalized Arenes with 1,6-Diynes via Rhodium-Catalyzed Directing-Group-Free C–H Bond Activation
Authors: Tanaka Ken , Takahashi Hiroto , Honjo Yusaku , Shibata Yu , Nagashima Yuki
Published: December 2020

It has been established that the dienylation of unfunctionalized arenes with 1,6-diynes, possessing aryl groups at the diyne termini, proceeds to give the corresponding dienylated arenes in the presence of a catalytic amount of an electron-deficient cyclopentadienyl rhodium(III) complex, [CpERhCl2]2, and a stoichiometric amount of silver carbonate. Experimental and theoretical mechanistic studies revealed that a CpERh(I) complex generated in situ might catalyze the present dienylation­ reaction.
Chylothorax Associated with Congenital Complete Atrioventricular Block
Authors: Fujino Shuhei , Maruyama Hidehiko , Tsukamoto Keiko , Ono Hiroshi , Isayama Tetsuya , Ito Yushi
Published: December 2020

Introduction Congenital complete atrioventricular block (CCAVB) associated with congenital chylothorax is a rare finding that has been reported in only one case in the literature. We report here the case of an infant with CCAVB complicated by congenital chylothorax.

Patient Report We present the case of a male neonate with a birth weight of 2114 g. Fetal bradycardia and right pleural effusion were detected at gestational age of 22 weeks. Maternal serum levels of anti-Sjögren's-syndrome-related antigen A autoantibody were high (4840 U/mL). The neonate was delivered at gestational age of 33 weeks; a temporary external pacemaker was placed immediately after birth that resulted in an improved cardiac output. Milk-colored pleural effusion increased in volume together with the initiation of breast milk feeding. Lymphocytosis and high triglyceride levels in the pleural fluid led to the diagnosis of chylothorax. The pleural effusion resolved in response to prednisolone, octreotide, and total parenteral nutrition.

Discussion The causal relationship between CCAVB and congenital chylothorax can be explained by considering the damage to the lymphatic vessels secondary to inflammation due to maternal autoantibodies and venous congestion due to bradycardia.

Conclusion In any case of CCAVB associated with atypical pleural effusion, one must consider the possibility of congenital chylothorax.
Implementation of Evidence-Based Cervical Ripening Protocol: Outcomes and Next Steps
Authors: Zakama Arthurine , Sobhani Nasim C. , Lamar Robyn , Rosenstein Melissa G.
Published: December 2020

Objective A prominent randomized controlled trial demonstrated that low-dose misoprostol with the concurrent cervical Foley shortened the median time to delivery when compared with either method alone. Our study aims to address implementation of this protocol and evaluate its impact on time to delivery.

Study Design This was a retrospective before-and-after study of nulliparous women who delivered nonanomalous, term, singletons at the University of California San Francisco (UCSF) in two separate 2-year periods before and after changes in UCSF's cervical ripening protocol. The primary outcome was time from first misoprostol dose to delivery.

Results A total of 1,496 women met inclusion criteria, with 698 in the preimplementation group and 798 in the postimplementation group. There were no statistically significant differences in time to delivery (29 vs. 30 hours, p = 0.69), rate of cesarean delivery (30 vs. 26%, p = 0.09), or cesarean delivery for fetal indications (11 vs. 8%, p = 0.15) between the groups.

Conclusion Implementing evidence-based low-dose misoprostol with the concurrent cervical Foley did not change the time to delivery, time to vaginal-delivery, or likelihood of vaginal delivery in our population. This may be due to differences in labor management practices and incomplete fidelity to the protocol. Real-world effectiveness of these interventions will vary and should be considered when choosing an induction method.
Hybrid quantum computing circuit combines quantum devices with readout amplifier
Authors: Frank Jodi Ackerman
Published: December 2020

Researchers demonstrated a transimpedance amplifier capable of operating at the same cryogenic temperatures as quantum devices.
Revealing the evolving mixture of molecular aggregates during organic film formation using simulations of in situ absorbance
Authors: Sosa Morgan L. , Wong Cathy Y.
Published: December 2020

In this work, we introduce a method for modeling the evolving absorbance spectrum of an organic molecule, pseudoisocyanine (PIC), measured during the process of molecular aggregation. Despite being historically considered a J-aggregate, we find that the absorbance spectrum of PIC cannot be adequately modeled using solely J-aggregates either during molecular aggregation or in the final dry film. The collection of absorbance spectra during solution-casting is particularly difficult since a distribution of aggregates with various sizes and structures can coexist. Here, spectra measured during film formation are fit to a weighted sum of simulated spectra of two aggregate species, revealing the combinations of Coulombic coupling values, Huang–Rhys parameters, and aggregate sizes that provide good fits to measured spectra. The peak intensity ratios and relative peak positions are highly sensitive to the aggregate structure, and fitting only these features enables the rapid comparison of aggregate combinations. We find that the spectra of PIC aggregates cannot be modeled using the Huang–Rhys factor of the PIC monomer, as is typically assumed, leading us to consider models that utilize independent Huang–Rhys factors for each aggregate species. This method of fitting only the key spectral features allows an experimental spectrum to be modeled within 1 h–2 h when using a single Huang–Rhys factor, making the simulation of a series of in situ measurements during aggregation computationally feasible.
Interferometric speckle visibility spectroscopy (ISVS) for human cerebral blood flow monitoring
Authors: Xu Jian , Jahromi Ali K. , Brake Joshua , Robinson J. Elliott , Yang Changhuei
Published: December 2020

Infrared light scattering methods have been developed and employed to non-invasively monitor human cerebral blood flow (CBF). However, the number of reflected photons that interact with the brain is low when detecting blood flow in deep tissue. To tackle this photon-starved problem, we present and demonstrate the idea of interferometric speckle visibility spectroscopy (ISVS). In ISVS, an interferometric detection scheme is used to boost the weak signal light. The blood flow dynamics are inferred from the speckle statistics of a single frame speckle pattern. We experimentally demonstrated the improvement in the measurement of fidelity by introducing interferometric detection when the signal photon number is low. We apply the ISVS system to monitor the human CBF in situations where the light intensity is ∼100-fold less than that in common diffuse correlation spectroscopy (DCS) implementations. Due to the large number of pixels (∼2 × 105) used to capture light in the ISVS system, we are able to collect a similar number of photons within one exposure time as in normal DCS implementations. Our system operates at a sampling rate of 100 Hz. At the exposure time of 2 ms, the average signal photoelectron number is ∼0.95 count/pixel, yielding a single pixel interferometric measurement signal-to-noise ratio (SNR) of ∼0.97. The total ∼2 × 105 pixels provide an expected overall SNR of 436. We successfully demonstrate that the ISVS system is able to monitor the human brain pulsatile blood flow, as well as the blood flow change when a human subject is doing a breath-holding task.
Insights into airfoil response to sinusoidal gusty inflow by oscillating vanes
Authors: Wu Zhenlong , Bangga Galih , Lutz Thorsten , Kampers Gerrit , Hölling Michael
Published: December 2020

Gust response is one of the classic topics in aerodynamics. Two different transfer functions, Sears and Atassi, have been used to model the unsteady lift responses of an airfoil experiencing a sinusoidal gust over the past few decades. However, a significant discrepancy against measured data has consistently been observed. Although the discrepancy at high frequencies was solved by a correct normalization of the lift response of an airfoil [Wei et al., “Insights into the periodic gust response of airfoils,” J. Fluid Mech. 876, 237 (2019)], totally opposite trends emerged between the experimental data and both functions at low frequencies. To clarify the observed discrepancy, both wind-tunnel experiments and numerical simulations are performed in this study to characterize the Sears and Atassi inflow conditions generated by oscillating grid vanes. A scaling law is established for fast determination of the oscillation parameters of the vanes required to generate a specific gust angle. The gust-angle phase shift between the empty-tunnel and test airfoil cases is quantified. A universal transfer function normalization method is proposed for arbitrary sinusoidal gusts and arbitrary airfoil shapes. The discrepancy between the measured and theoretical lift responses at low gust frequencies is found to be related to the dynamic effect of the highly turbulent wakes of the oscillating vanes as well as the large installation angle of the test airfoil.
Pressure-induced octahedral tilting distortion and structural phase transition in columbite structured NiNb2O6
Authors: Karmakar S. , Garg Alka B. , Sahu Mrinmay , Tripathi Anjana , Mukherjee Goutam Dev , Thapa Ranjit , Behera D.
Published: December 2020

High-pressure behavior of the technologically important compound NiNb2O6 adopting a columbite-type orthorhombic structure at ambient pressure and temperature conditions was investigated using synchrotron x-ray powder diffraction, Raman spectroscopic measurements, and first-principles calculations. The x-ray diffraction data indicate the occurrence of irreversible pressure-induced structural phase transition in the studied compound beyond 9 GPa. The high-pressure phase is found to be monoclinic with space group P2/m. The large volume collapse (∼4.4%) at the transition indicates the nature of the transition to be of the first order. There is a change in oxygen anion coordination number around Nb from 6 to 8; however, the coordination number around Ni remains 6. The experimental pressure–volume data when fitted to the Birch−Murnaghan equation of states yield the value of ambient pressure bulk modulus (B0) as 178.7 (17) GPa for the orthorhombic phase and 244 (6) for the high-pressure monoclinic phase. The changes in Raman spectra indicate the distortion of NbO6 octahedra resulting in structural phase transitions. The logarithmic variation of unit cell volume (V) with optical lattice mode frequency (ν) helped us to calculate their respective Grüneisen parameters (γ) and it also supports the instability of the orthorhombic columbite structure of NiNb2O6 beyond 9 GPa, originated due to strong octahedral deformation of NbO6 octahedra. The variation of structural, electronic, and optical properties with pressure has also been discussed through first-principles calculations based on density functional theory using the revised Perdew–Burke–Ernzerh of generalized gradient approximation. The theoretical bandgap collapses and the distortion of NbO6 octahedra through the O chains with pressure are emphasized from the density of states data.
On the role of thermo-transport properties in the convective/absolute transition of heated round jets
Authors: Demange S. , Pinna F.
Published: December 2020

The effect of thermodynamic and transport properties on the convective-to-absolute transition in heated round jets is investigated with the spatio-temporal linear stability theory, by considering three sets of properties with increasing complexity. Present models include (i) a constant property model often used in the literature, (ii) a simplified model with variable properties, and (iii) a more accurate equilibrium air mixture model, accounting for dissociation reactions in the flow. A family of arbitrary single-stream and dual-stream jet profiles, representative of typical configurations studied in the literature, is investigated and adapted to each model. Our results show that considering a variable viscosity and thermal conductivity has a destabilizing effect on absolute instabilities in the viscous regime. Furthermore, this destabilization is stronger for the outer mode in dual-stream jets than for the inner mode or the jet-column mode in single-stream jets. With sufficient heating (S < 0.3), results obtained with the equilibrium model strongly depart from those of calorically perfect gas models and display absolute domains deformed by the chemical activity. For absolute instabilities triggered by the baroclinic torque such as jet-column and inner modes, the convective-to-absolute transition is shifted toward thinner and hotter configurations, while the opposite is observed for the outer mode. Finally, we observe a dependence of the equilibrium model stability properties on the static pressure.
Normal mode analysis of spectral density of FMO trimers: Intra- and intermonomer energy transfer
Authors: Klinger Alexander , Lindorfer Dominik , Müh Frank , Renger Thomas
Published: December 2020

The intermolecular contribution to the spectral density of the exciton-vibrational coupling of the homotrimeric Fenna–Matthews–Olson (FMO) light-harvesting protein of green sulfur bacteria P. aestuarii is analyzed by combining a normal mode analysis of the protein with the charge density coupling method for the calculation of local transition energies of the pigments. Correlations in site energy fluctuations across the whole FMO trimer are found at low vibrational frequencies. Including, additionally, the high-frequency intrapigment part of the spectral density, extracted from line-narrowing spectra, we study intra- and intermonomer exciton transfer. Whereas the intrapigment part of the spectral density is important for fast intramonomer exciton relaxation, the intermolecular contributions (due to pigment-environment coupling) determine the intermonomer exciton transfer. Neither the variations of the local Huang–Rhys factors nor the correlations in site energy fluctuations have a critical influence on energy transfer. At room temperature, the intermonomer transfer in the FMO protein occurs on a 10 ps time scale, whereas intramonomer exciton equilibration is roughly two orders of magnitude faster. At cryogenic temperatures, intermonomer transfer limits the lifetimes of the lowest exciton band. The lifetimes are found to increase between 20 ps in the center of this band up to 100 ps toward lower energies, which is in very good agreement with the estimates from hole burning data. Interestingly, exciton delocalization in the FMO monomers is found to slow down intermonomer energy transfer, at both physiological and cryogenic temperatures.
Large coupling-strength expansion of the Møller–Plesset adiabatic connection: From paradigmatic cases to variational expressions for the leading terms
Authors: Daas Kimberly J. , Grossi Juri , Vuckovic Stefan , Musslimani Ziad H. , Kooi Derk P. , Seidl Michael , Giesbertz Klaas J. H. , Gori-Giorgi Paola
Published: December 2020

We study in detail the first three leading terms of the large coupling-strength limit of the adiabatic connection that has as weak-interaction expansion the Møller–Plesset perturbation theory. We first focus on the H atom, both in the spin-polarized and the spin-unpolarized cases, reporting numerical and analytical results. In particular, we derive an asymptotic equation that turns out to have simple analytical solutions for certain channels. The asymptotic H atom solution for the spin-unpolarized case is then shown to be variationally optimal for the many-electron spin-restricted closed-shell case, providing expressions for the large coupling-strength density functionals up to the third leading order. We also analyze the H2 molecule and the uniform electron gas.
Covalent incorporation of diphenylanthracene in oxotriphenylhexanoate organogels as a quasi-solid photon upconversion matrix
Authors: Barbosa de Mattos Deise F. , Dreos Ambra , Johnstone Mark D. , Runemark August , Sauvée Claire , Gray Victor , Moth-Poulsen Kasper , Sundén Henrik , Abrahamsson Maria
Published: December 2020

Triplet–triplet annihilation photon upconversion (TTA-UC) in solid state assemblies are desirable since they can be easily incorporated into devices such as solar cells, thus utilizing more of the solar spectrum. Realizing this is, however, a significant challenge that must circumvent the need for molecular diffusion, poor exciton migration, and detrimental back energy transfer among other hurdles. Here, we show that the above-mentioned issues can be overcome using the versatile and easily synthesized oxotriphenylhexanoate (OTHO) gelator that allows covalent incorporation of chromophores (or other functional units) at well-defined positions. To study the self-assembly properties as well as its use as a TTA-UC platform, we combine the benchmark couple platinum octaethylporphyrin as a sensitizer and 9,10-diphenylanthracene (DPA) as an annihilator, where DPA is covalently linked to the OTHO gelator at different positions. We show that TTA-UC can be achieved in the chromophore-decorated gels and that the position of attachment affects the photophysical properties as well as triplet energy transfer and triplet–triplet annihilation. This study not only provides proof-of-principle for the covalent approach but also highlights the need for a detailed mechanistic insight into the photophysical processes underpinning solid state TTA-UC.
Dynamics of the supercavitating hydrofoil with cavitator in steady flow field
Authors: Xu Chang , Khoo Boo Cheong
Published: December 2020

Maintaining stability remains a crucial issue for the safety of underwater vehicles, especially during high-speed navigation where flow cavitation may occur. Cavitators are small protrusions on the hydrofoil surface, which can be used to control the patterns of flow cavitation. In this study, we investigate the effect of cavitators on supercavitating flow and hydrodynamic forces for high-speed hydrofoil. The volume of fluid method and the large eddy simulation turbulence model with the Kunz cavitation model are used in the simulations in order to accurately capture the interface between two phases (water and vapor) and the region of flow supercavitation. To validate the numerical method, the time-averaged simulated results of the supercavitating flow over a wedge-shaped hydrofoil are compared and validated against the experimental data by Kermeen (“Experimental investigations of three-dimensional effects on cavitating hydrofoils,” Technical Report No. 47-14, Engineering Division of the California Institute of Technology, Pasadena, CA, 1960). Then, the numerical method is used to simulate the supercavitating flow of two-dimensional and three-dimensional cases with and without the cavitator placed on the lower side of the hydrofoil. The simulations were conducted for the cavitator located at the 1/32, 1/16, 1/8, and 1/4 chord of the hydrofoil at various angles of attack 1°–12° and cavitation numbers at 0.1, 0.2, and 0.4. A detailed analysis is made to examine the relations between cavitation pattern, hydrodynamic forces, and cavitator placement location. Compared to the cases without the cavitator, the supercavitating flow over the hydrofoils controlled by the cavitator demonstrates a significant difference in lift, whereas the drag does not change much. The changes in lift are closely related to the cavitator location. These findings can serve as a good guidance on how to improve the hydrodynamic performance and stability condition of a high-speed hydrofoil/wing using the cavitator.
Electrically tunable detector of THz-frequency signals based on an antiferromagnet
Authors: Safin A. , Puliafito V. , Carpentieri M. , Finocchio G. , Nikitov S. , Stremoukhov P. , Kirilyuk A. , Tyberkevych V. , Slavin A.
Published: December 2020

A concept of an electrically tunable resonance detector of THz-frequency signals based on an antiferromagnetic/heavy metal (AFM/HM) heterostructure is proposed. The conversion of a THz-frequency input signal into DC voltage is done using the inverse spin Hall effect in an (AFM/HM) bilayer. An additional bias DC in the HM layer can be used to vary the effective anisotropy of the AFM and, therefore, to tune the antiferromagnetic resonance (AFMR) frequency. The proposed AFM/HM heterostructure works as a resonance-type quadratic detector, which can be tuned by the bias current in the range of at least 10% of the AFMR frequency, and our estimations show that the sensitivity of this detector could be comparable to that of modern detectors based on the Schottky, Gunn, or graphene-based diodes.
The σ-hole⋯σ-hole stacking interaction: An unrecognized type of noncovalent interaction
Authors: Zhang Yu , Wang Weizhou
Published: December 2020

The σ-hole⋯σ-hole stacking interaction, an unrecognized type of noncovalent interaction, has been found to be present in large quantities in the Cambridge Structural Database. In the σ-hole⋯σ-hole stacking interaction, each of the two interacting σ-holes has the dual electron donor/electron acceptor character; when one σ-hole acts as an electron donor, the other σ-hole acts as an electron acceptor, and vice versa. The σ-hole⋯σ-hole stacking interaction is clearly different from the σ-hole bond in which the charge transfer occurs mainly from the electron donor to the σ-hole. Energy component analysis shows that the σ-hole⋯σ-hole stacking interaction is dominated by the dispersion energy, which is similar to the nature of the aromatic stacking interaction between unsaturated molecules or the σ⋯σ stacking interaction between saturated molecules.