bluuebunny/crossref_metadata_2025 huggingface dataset:
Organocatalytic enantioselective Diels–Alder reaction between hydroxymaleimides and in situ generated nitrosoalkenes for direct preparation of chiral hemiketals with 1,2-oxazine skeleton
Authors: Xiang Min , Li Chen-Yi , Zhang Jian , Zou Ying , Li Wen-Sheng , Tian Fang , Wan Wen-Juan , Wang Li-Xin
Published: August 2021

Organocatalytic Enantioselective IEDDA reaction between hydroxymaleimides and in situ generated nitrosoalkenes has been disclosed, a series of chiral hemiketals containing 5,6-dihydro-4H-l,2-oxazines and succinimide frameworks have been prepared.
Honeycomb-like Fe/Fe3C-doped porous carbon with more Fe–Nx active sites for promoting the electrocatalytic activity of oxygen reduction
Authors: Wu Guiming , Shao Chunfeng , Cui Boyang , Chu Hailiang , Qiu Shujun , Zou Yongjin , Xu Fen , Sun Lixian
Published: August 2021

Fe-doped nitrogen-enriched porous carbon with a honeycomb-like structure exhibits high catalytic activity toward electrochemical oxygen reduction due to the presence of Fe nanoparticles and Fe3C species.
Combined description of polymer PVT and relaxation data using a dynamic “SL-TS2” mean-field lattice model
Authors: Ginzburg Valeriy V.
Published: August 2021

We develop a combined model to describe the pressure–volume–temperature (PVT) thermodynamics and the α- and β-relaxation time dynamics in glass-forming amorphous materials.
Bromide–acetate co-mediated high-power density rechargeable aqueous zinc–manganese dioxide batteries
Authors: Wu Jing , Li Yining , Huang Jiaqi , Chi Xiaowei , Yang Jianhua , Liu Yu
Published: August 2021

A new bromide-acetate co-mediated multicomponent metal-ion aqueous electrolyte was for the first time developed to achieve a high specific capacity two-electron transfer reaction between Mn2+ and MnO2 with extremely fast reaction kinetics.
On the secrecy outage analysis of underlay cognitive radio systems with buffer‐aided relaying under Nakagami‐m channels
Authors: Saber Mohammad Javad , Naseri Mohsen , Sadough Seyed Mohammad Sajad
Published: August 2021

In this work, the physical layer security performance of an underlay cognitive buffer‐aided relay network over the general Nakagami‐m fading channel model is addressed, where a primary source communicates with a destination via a decode‐and‐forward relay node in the presence of an eavesdropper and a secondary communication system. The relay is equipped with a finite‐size storage equipment or buffer which can store the sequence of received data packets from source and forward it immediately or subsequently in an adequate time‐slot. In this way, the buffer relay enables to adopt a link selection scheme in order to detect the best available link, (i.e. the one with higher secrecy rate) among the available data at source or at the relay buffer. The closed‐form expression for the secrecy outage probability (SOP), which is a widely adopted performance metric in the considered scenario, is also derived. Numerical results confirm the accuracy of the derived closed‐form analytic expression for SOP and indicates the interaction between secrecy performance and the Nakagami channel parameter m. In particular, it is shown that the SOP experiences a significant drop as the Nakagami channel parameter increases for a predefined target secrecy rate.
Broich, Fränkel und Harke: Geschichte des deutschen rhinologischen Beitrags zur Nasenspülung
Authors: Loennecken Iver Christian
Published: August 2021

Anhand der frei verfügbaren Literatur wird die Entwicklung der Nasenspüler nach Broich, Fränkel und Harke dargestellt. Es wird dabei auf die Nasenspülung als Therapiemaßnahme, die dabei verwendeten Therapeutika und die persönliche Geschichte der jeweiligen Entwickler eingegangen.
Psychophysiologie der Körperhaltung
Authors: Behrens Nicolas
Published: August 2021

Die Psyche drückt sich in der Körperhaltung aus– und ist umgekehrt vom Körper zu beeinflussen. Die Muskeln dienen nicht nur der Bewegung und der dynamischen Stabilisation von Rumpf und Extremitäten, sondern sind mit ihren Rezeptoren auch die Basis unserer Eigenwahrnehmung, der Propriozeption. Sie speichern zudem Emotionen, mit denen wir nicht umgehen konnten, und dienen der Kommunikation.

Auffälligkeiten der Haltung und von Bewegungsabläufen können Therapeuten somato-psychisch verstehen und analysieren. Das System der Akupunktur mit den durch zugehörige Räume und Themen erweiterten Leitbahnachsen ist eine sinnvolle Übersetzungshilfe. Mögliche Therapieoptionen, die den Menschen in seiner inneren Entwicklung und Aufrichtung zu unterstützen, wie zum Beispiel die Akupunktur, aber auch das Kinesio-Taping, bis hin zu körperorientierten Therapieverfahren werden angesprochen.
Prenatal Ultrasound Diagnosis of Biometric changes in the Brain of Growth Restricted Fetuses. A Systematic Review of Literature
Authors: Silva Patrícia Isabel Pereira , Perez Miriam
Published: August 2021

Fetal growth restriction (FGR) occurs when the fetus does not reach its intrauterine potential for growth and development as a result of compromise in placental function. It is a condition that affects 5 to 10% of pregnancies and is the second most common cause of perinatal morbidity and mortality. Children born with FGR are at risk of impaired neurological and cognitive development and cardiovascular or endocrine diseases in adulthood. The purpose of the present revision is to perform a literature search for evidence on the detection and assessment by ultrasound of brain injury linked to FGR during fetal life. Using a systematic approach and quantitative evaluation as study methodology, we reviewed ultrasound studies of the fetal brain structure of growth-restricted fetuses with objective quality measures. A total of eight studies were identified. High quality studies were identified for measurement of brain volumes; corpus callosum; brain fissure depth measurements, and cavum septi pellucidi width measurement. A low-quality study was available for transverse cerebellar diameter measurement in FGR. Further prospective randomized studies are needed to understand the changes that occur in the brain of fetuses with restricted growth, as well as their correlation with the changes in cognitive development observed.
Hepatic Liquoric Cyst as a Complication of Ventriculoperitoneal Shunt Insertion: A Case Report
Authors: Macêdo Lívio Pereira de , Ugulino Netto Arlindo , Franke Kauê , Eugenio Pierre Vansant Oliveira , Freitas Lucas Ribeiro de Moraes , Leone Davi Coutinho Marcelino Guerra , Oliveira Diego Pereira de Melo , Carvalho Júnior Eduardo Vieira de , Faquini Igor Vilela , Almeida Nivaldo S. , Azevedo-Filho Hildo Rocha Cirne
Published: August 2021

Background The ventriculoperitoneal shunt (VPS) procedure is still the most used technique for management of hydrocephalus. This article reports a case of hepatic cerebrospinal fluid (CSF) pseudocyst as a rare, but important, complication of the VPS insertion.

Case Description An 18-year-old male presented to the hospital complaining of temporal headache and visual turbidity for approximately 3 months with a history of VPS insertion for treatment of hydrocephalus and revision of the valve in adolescence. The diagnosis was based on abdominal imaging, demonstrating an extra-axial hepatic CSF pseudocyst free from infection. Following the diagnosis, the management of the case consisted in the removal and repositioning of the catheter on the opposite site of the peritoneum.

Conclusion The hepatic CSF pseudocyst is an infrequent complication of VPS procedure, but it needs to be considered when performing the first evaluation of the patient. Several techniques are considered efficient for the management of this condition, the choice must be made based on the variables of each individual case.
Videolaryngoscopy Findings of the Vocal Health Program in Dysphonic Teachers in the Federal District, Brazil
Authors: Granjeiro Ronaldo Campos , Oliveira Lorena Cássia de Carvalho , Dias Mirela Alves , Oliveira Cristiane Ferraz de , Oliveira Glauce Mara Gomes Ferreira
Published: August 2021

Introduction The high phonatory demand required of teachers is a direct cause of the onset of vocal symptoms and of the development of laryngeal disorders.

Objective To describe the findings of the laryngeal screening performed as part of the Vocal Health Program held in the Federal Distrcit of Brazil in 2014 and 2015.

Methods The study was performed with 361 dysphonic teachers from public schools who attended the laryngeal screening (videolaryngoscopy) part of the program. Data on anamnesis, the degree of dysphonia, the findings of the laryngeal screening, the referrals made after the laryngeal screening, and the result of the assessment of vocal aptitude for work were analyzed from the forms of each participating teacher.

Results The sample of the present study (N = 361) represents 18.23% of the 1,980 teachers that went through the vocal screening of the program in 2014 and 2015. In total, 98 (27.15%) teachers presented mild dysphonia, 221 (61.22%), moderate dysphonia, and 42, (11.63%) severe dysphonia. Regarding the laryngeal screening (videolaryngoscopy exam), 269 teachers (74.52%) presented laryngeal disorders, and the main ones found were vocal nodules (43.87%), signs of laryngopharyngeal reflux (37.17%), hourglass chink (18.22%), vascular dysgenesis (18.22%), midposterior triangular chink (9.67%), and double chink (8.55%).

Conclusion Laryngeal screening through videolaryngoscopy and auditory-perceptual screening of the voice as part of vocal health programs are essential to define the diagnosis and therapeutic conduct for teachers with dysphonia. Together with intervention activities, continuing education and adequate and accessible treatment, the periodic evaluation of vocal health can contribute to reduce absenteeism and improve the quality of life and of the voice of teachers.
Miniature sensor can measure magnetic field in smaller situations
Authors: Patrick Chris
Published: August 2021

A relatively small magneto-inductive sensor can measure the low vector magnetic field for applications where a fluxgate sensor is too large.
Sum-over-state expressions including second-order Herzberg–Teller effects for the calculation of absorption and resonance Raman intensities
Authors: Guthmuller Julien
Published: August 2021

The sum-over-state expressions are derived to calculate the second-order Herzberg–Teller (HT) effects in absorption and resonance Raman spectroscopies. These effects depend on the second derivatives of the transition dipole moment with respect to the vibrational coordinates. The method is applied to the molecule of 1,3-butadiene using density functional theory calculations. It is found that the second-order HT effects are significant for both absorption and resonance Raman intensities, and that the calculated spectra are in good agreement with the experimental data. The second-order HT effects originate from diagonal elements of the second derivatives matrix, whereas non-diagonal elements have a negligible impact on the intensities of 1,3-butadiene.
Local epitaxial-like templating effects and grain size distribution in atomic layer deposited Hf0.5Zr0.5O2 thin film ferroelectric capacitors
Authors: Lombardo S. F. , Tian M. , Chae K. , Hur J. , Tasneem N. , Yu S. , Cho K. , Kummel A. C. , Kacher J. , Khan A. I.
Published: August 2021

The microstructure in fluorite-structure oxide-based ferroelectric thin films, especially when on standard semiconductor manufacturing platforms, is poly-/nano-crystalline, which controls the functionality, performance, and reliability of the device technologies based on them. Understanding the relationships between microstructure, process, and performance for this class of materials has remained challenging. Here, a systematic approach is presented for analyzing and visualizing grains, their size distributions, and interlayer templating effects in ferroelectric thin film systems by utilizing an advanced microscopy technique, namely nanobeam electron diffraction, coupled with dark-field transmission electron microscopy and atomic resolution scanning transmission electron microscopy. A 10 nm TiN/10 nm Hf0.5Zr0.5O2 (HZO)/10 nm TiN ferroelectric heterostructure is probed. A geometric mean of the grain size in HZO of 26.8 nm ranging from 5 to 95 nm with top and bottom TiN layers having a much smaller grain size of approximately 6.8 nm ranging from 3 to 17 nm is observed. Furthermore, there is evidence of templating effects between HZO and TiN grain and domain boundaries showing [111] and [001] growth directions locally for HZO and TiN, respectively.
Ultrahigh-aspect-ratio beam generation with super-resolution spot
Authors: Xu Ning , Liu Guoxuan , Zhao Yanbo , Tan Qiaofeng
Published: August 2021

Focusing to a small spot along a large depth of focus (DOF) beyond the limits imposed by diffraction has attracted extensive theoretical as well as practical interest. The aspect ratio, defined as the DOF divided by the diameter of spot, has been extended by several schemes with reasonable success, but there is no report that enables one to modulate the aspect ratio as long as possible with sidelobe suppression. In this Letter, we propose a method to generate ultrahigh-aspect-ratio beams (UARBs) by introducing an analytic procedure using Zernike polynomials in the modified iterative Fourier-transform algorithm, and a super-resolution spot is also realized to further extend the aspect ratio. We design the diffractive optical elements that generate UARBs with sidelobe suppression and further experimentally demonstrate a stretched 1602:1 aspect ratio of UARBs with a lateral super-resolution spot, suggesting potential applications for further super-resolution imaging or precision fabrication.
Acoustic manipulation on microbubbles along arbitrary trajectories and adjustable destination
Authors: Huang Jie , Zhou Qinxin , Ren Xuemei , Xu Zheng , Liu Xiaojun
Published: August 2021

Non-diffracting Bessel acoustic beam that propagates in three dimensions has the properties of self-healing, self-bending, and self-acceleration, giving them many potential applications. Here, we report a zero-order Bessel-like acoustic beam that propagates along a curved trajectory with a phase-modulating acoustic holographic lens. Its pressure distribution on the transverse section approximately conforms to the zero-order Bessel function, and the self-healing property is found. In addition, the maximum point of acoustic intensity on the beam mainlobe can be adjusted by the change in the acoustic frequency. Microbubbles can be forced toward the maximum point along the predefined curve. Therefore, such a beam can be used for the directional transportation of microbubbles with a predefined curve and an adjustable destination. We have numerically calculated the primary Bjerknes force, including the oscillation of the microbubbles with the shell and experimentally proved the curved trajectory and the adjustable destination of the transportation of microbubbles. The proposed method uses the conservative part of the radiation force, which controls the trajectory of microbubbles by the amplitude gradient. The relatively free design of the transport trajectory and destination makes the approach suitable in vivo.
Low dephasing and robust micromagnet designs for silicon spin qubits
Authors: Dumoulin Stuyck N. I. , Mohiyaddin F. A. , Li R. , Heyns M. , Govoreanu B. , Radu I. P.
Published: August 2021

Using micromagnets to enable electron spin manipulation in silicon qubits has emerged as a very popular method, enabling single-qubit gate fidelities larger than 99.9%. However, these micromagnets also apply stray magnetic field gradients onto the qubits, making the spin states susceptible to electric field noise and limiting their coherence times. We describe here a magnet design that minimizes qubit dephasing, while allowing for fast qubit control and addressability. Specifically, we design and optimize magnet dimensions and positions relative to the quantum dots, minimizing dephasing from magnetic field gradients. The micromagnet-induced dephasing rates with this design are up to three orders of magnitude lower than state-of-the-art implementations, allowing for long coherence times. This design is robust against fabrication errors and can be combined with a wide variety of silicon qubit device geometries, thereby allowing exploration of coherence limiting factors and novel upscaling approaches.
Effect of configuration-dependent multi-body forces on interconversion kinetics of a chiral tetramer model
Authors: Petsev Nikolai D. , Stillinger Frank H. , Debenedetti Pablo G.
Published: August 2021

We describe a reformulation of the four-site molecular model for chiral phenomena introduced by Latinwo et al. [“Molecular model for chirality phenomena,” J. Chem. Phys. 145, 154503 (2016)]. The reformulation includes an additional eight-body force that arises from an explicit configuration-dependent term in the potential energy function, resulting in a coarse-grained energy-conserving force field for molecular dynamics simulations of chirality phenomena. In this model, the coarse-grained interaction energy between two tetramers depends on their respective chiralities and is controlled by a parameter λ, where λ < 0 favors local configurations involving tetramers of opposite chirality and λ > 0 gives energetic preference to configurations involving tetramers of the same chirality. We compute the autocorrelation function for a quantitative chirality metric and demonstrate that the multi-body force modifies the interconversion kinetics such that λ ≠ 0 increases the effective barrier for enantiomer inversion. Our simulations reveal that for λ > 0 and temperatures below a sharply defined threshold value, this effect is dramatic, giving rise to spontaneous chiral symmetry breaking and locking molecules into their chiral identity.
Experimental velocity data estimation for imperfect particle images using machine learning
Authors: Morimoto Masaki , Fukami Kai , Fukagata Koji
Published: August 2021

We propose a method using supervised machine learning to estimate velocity fields from particle images having missing regions due to experimental limitations. As a first example, a velocity field around a square cylinder at the Reynolds number of ReD=300 is considered. To train machine learning models, we utilize artificial particle images (APIs) as the input data, which mimic the images of the particle image velocimetry (PIV). The output data are the velocity fields, and the correct answers for them are given by a direct numerical simulation (DNS). We examine two types of the input data: APIs without missing regions (i.e., full APIs) and APIs with missing regions (lacked APIs). The missing regions in the lacked APIs are assumed following the exact experimental situation in our wind tunnel setup. The velocity fields estimated from both full and lacked APIs are in great agreement with the reference DNS data in terms of various statistical assessments. We further apply these machine learned models trained with the DNS data to experimental particle images so that their applicability to the exact experimental situation can be investigated. The velocity fields estimated by the machine learned models contain approximately 40 fold denser data than that with the conventional cross-correlation method. This finding suggests that we may be able to obtain finer and hidden structures of the flow field, which cannot be resolved with the conventional cross-correlation method. We also find that even the complex flow structures are hidden due to the alignment of two square cylinders, the machine learned model is able to estimate the field in the missing region reasonably well. The present results indicate a great potential of the proposed machine learning-based method as a new data reconstruction method for PIV.
Infrared spectroscopy of carbocations upon electron ionization of ethylene in helium nanodroplets
Authors: Erukala Swetha , Feinberg Alexandra , Singh Amandeep , Vilesov Andrey F.
Published: August 2021

The electron impact ionization of helium droplets doped with ethylene molecules and clusters yields diverse CXHY+ cations embedded in the droplets. The ionization primarily produces C2H2+, C2H3+, C2H4+, and CH2+, whereas larger carbocations are produced upon the reactions of the primary ions with ethylene molecules. The vibrational excitation of the cations leads to the release of bare cations and cations with a few helium atoms attached. The laser excitation spectra of the embedded cations show well resolved vibrational bands with a few wavenumber widths—an order of magnitude less than those previously obtained in solid matrices or molecular beams by tagging techniques. Comparison with the previous studies of free and tagged CH2+, CH3+, C2H2+, C2H3+, and C2H4+ cations shows that the helium matrix typically introduces a shift in the vibrational frequencies of less than about 20 cm−1, enabling direct comparisons with the results of quantum chemical calculations for structure determination. This work demonstrates a facile technique for the production and spectroscopic study of diverse carbocations, which act as important intermediates in gas and condensed phases.
Ionization potentials for the H2CO trimer
Authors: de Souza Gabriel L. C. , Peterson Kirk A.
Published: August 2021

In this work, a computational study on the ionization potentials (IPs) of the formaldehyde trimer, (H2CO)3, is presented. Twelve lowest-lying vertical IPs were determined through the use of the coupled-cluster level of theory using correlation consistent basis sets with extrapolation to the complete basis set limit and consideration of core electron correlation effects. Specifically, the equation-of-motion ionization potential coupled-cluster with single and double excitations method with the aug-cc-pVnZ and aug-cc-pCVnZ (n = D and T) basis sets was used. The Feller–Peterson–Dixon (FPD) composite approach was employed to provide accurate IPs, and eight conformations of (H2CO)3 were considered. The FPD IPs determined for (H2CO)3 were found to be systematically lower than those computed for the dimer and monomer of H2CO in the pattern IP(monomer) > IP(dimer) > IP(trimer) for a given IP. In addition, the IPs calculated when considering only the more stable conformation (C0) are in good agreement with those obtained using the eight conformations of the H2CO trimer, and thus, the actual conformation played only a minor role in determining such properties in the present case. By providing first accurate IP results for the H2CO trimer, we hope to motivate future experimental and computational investigations (e.g., studies involving photoionization) that rely on such quantities.
Evaluation of vibration mode shape using a mechanoluminescent sensor
Authors: Chen Bing , Peng Deng-Feng , Lu Pin , Sheng Zhi-Peng , Yan Ke-Yu , Fu Yu
Published: August 2021

This study proposes a method to measure vibration mode shape on beam structures by using the elastic mechanoluminescent (EML) material SrAl2O4: Eu2+. The EML phenomenon has attracted interest due to its potential for application to strain distribution, crack visualization, and structural health monitoring. In this Letter, the relationship between the distribution of luminous intensity and the vibration mode shape of beam structures is explored and is found to be quadratic. A comparison between the results of experiments and simulations shows that the proposed method can measure a structure's vibration mode shape. The study also shows that experimental parameters, such as the exposure time of the camera and the amplitude of excitation, do not affect the validity of this method. The robustness and convenience of the proposed method make it a more efficient technique than prevalent electrical or optical vibrational methods of analysis.
Global patterns of raptor distribution and protected areas optimal selection to reduce the extinction crises
Authors: Cruz Carlos , Santulli-Sanzo Giulia , Ceballos Gerardo
Published: August 2021

Significance

Current extinction rates are caused by human activities, including habitat destruction. Here we analyze the global patterns of raptor distribution to determine priority areas for conservation. Raptors are top predators that can be used as umbrella species to help the conservation of other species. Our results provide insights into global strategies for conservation of different proportions of the geographic range of raptor species, minimizing socioeconomic conflict. These findings are fundamental to guide conservation actions that may help avert the massive current extinction crises.
PPAR-γ activation enhances myelination and neurological recovery in premature rabbits with intraventricular hemorrhage
Authors: Krishna Sunil , Cheng Bokun , Sharma Deep R. , Yadav Sunita , Stempinski Erin S. , Mamtani Sahil , Shah Elisa , Deo Anjali , Acherjee Trishna , Thomas Teena , Zhang Xusheng , Zhang Jinghang , Iacobas Dumitru A. , Ballabh Praveen
Published: August 2021

Significance

Intraventricular hemorrhage (IVH) is the most common neurological disorder of premature infants and remains a major cause of white matter injury in the survivors. No therapeutic strategy exists to prevent IVH-induced hypomyelination and cerebral palsy in these infants. We showed that pharmacological or genetic activation of peroxisome proliferator activated receptor-γ (PPAR-γ) ameliorated inflammation, oligodendrocyte progenitor cell (OPC) maturation, myelination, and motor function in rabbit kits with IVH. PPAR-γ activation also promoted microglial phagocytosis but did not reduce hydrocephalus. Transcriptomic analyses identified previously unrecognized PPAR-γ–induced genes in the isolated OPCs and microglia, which would reprogram these cells toward reducing inflammation and promoting myelination. The study highlights PPAR-γ–induced reversal of white matter injury in premature newborns with IVH and the underlying mechanisms.
Magnetic properties of the composition of nanocrystals and amorphous matrix in an alloy of the Fe-Nb-Si-B-Cu system
Authors: Golovachev E A , Pakhomova S A
Published: August 2021

It is shown that amorphous alloys of the Fe-Nb-Si-B-Cu system are practically not used as soft-magnetic materials in the initial (freshly quenching) state. It is proposed to perform post-quenching annealing of products to improve the soft-magnetic properties. Annealing modes, which remove winding and quenching stresses are studied. Is established the optimal annealing mode, in which a favorable structure is formed. It is an amorphous alloy-nanocrystal composition. This composition can significantly increase the magnetic permeability, reduce the coercive force and the loss of magnetization reversal. This treatment will provide optimal performance characteristics for the amorphous alloy used. The paper studies and compares the magnetic properties of the amorphous alloy-nanocrystal composition obtained at different annealing temperatures. It is shown that the most significant comparison is the dependence of the magnetic induction B (Tl) by the magnetic field strength H (A/m).
Study of structure and properties of multilayer materials based on titanium alloys
Authors: Plokhikh A I , Putirskiy S V , Wang Tao
Published: August 2021

Abstracts

The article presents the results of the study of the structure and properties of multilayer materials based on titanium alloys of various classes. The selection of initial compositions founded upon the approach previously tested in the development of multilayer materials based on steels is presented. The basic possibility of forming a laminar structure in titanium multilayer materials has been shown. Based on the analysis of the microstructure, especially the interlayer boundaries, the starting composition that is most suitable for this purpose has been proposed. In reliance upon the conducted tensile tests, it was established that multilayer materials based on titanium alloys have a complex of mechanical properties characteristic of this class of materials. The impact hardness tests performed, as well as the subsequent fractographic studies, allowed concluding about the effect of the condition of the interlayer boundary on the increase in the resistance of the material to dynamic fracture.
Bitumen-polymer compositions for asphalt concrete
Authors: Fedorova L V , Tretyakova Z O , Voronina M V
Published: August 2021

Annotation

One of the criteria for the level of development of countries is the condition of the road network. At present, the transport and operational characteristics of the majority of domestic highways lag behind the world level. Therefore, the need to create road surfaces with increased durability is very urgent. As a result of this research bitumen modified with polymers have been investigated. Based on measurements of time-dependent viscosity parameters (melting temperature, penetration and spin-spin relaxation time T2), it was found that at a thiol content of more than 25%, a continuous phase can form, which manifests itself as a sharp change in the properties of bitumen and is associated with phase inversion. A good compatibility of thermoplastic elastomers with a bituminous binder was revealed, and the resulting modified systems have high technical characteristics The proposed method for modifying bitumen can be recommended for obtaining roofing materials.
Investigation of the thermal characteristics of a metal-anisotropic composite contact pair
Authors: Talalaeva P , Bykov L , Ezhov A
Published: August 2021

The tendency to use various composite materials in the production of aircraft components and assemblies determines the relevance of the study of the anisotropic properties of these materials. Ceramic-matrix composites used in aviation rocket and space technology can be assigned certain anisotropic properties already at the production stage. The anisotropy of the material has a significant effect on the thermal characteristics of metal - ceramic-matrix composite contact pairs. This paper presents the results of numerical modelling of the thermal properties of contact interaction with the participation of an anisotropic ceramic matrix composite. It is shown that a change in the orientation of the fibers of the composite matrix with respect to the direction of the heat flux significantly changes the contact thermal resistance.
Numerical estimation of in-service damages’ effect on the load-bearing capacity of composite aircraft structures elements
Authors: Limonin M V , Dudarkov Y I , Levchenko E A
Published: August 2021

Annotation

One of the main problem on the way to the effective integration of polymer composite materials in aircrafts’ primary structures is the high sensitivity to various defects and damages. The main task in design is to create a composite aircraft structure such that any possible damage (defect) does not lead to a decrease in its load-bearing capacity below the limited load level. As a rule, in practice, this problem is solved by performing a large number of tests. The introduction of a “Building Block” approach based on modern numerical methods will reduce the required number of tests. In this paper, we consider the nonlinear numerical analysis to estimate the residual load-bearing capacity of a composite structure. It allows taking into account different progressive failure processes and their interaction within a single model. On an example of the composite panel with a “cut” it is shown that this method results in a sufficiently accurate residual strength prediction. However, due to its complexity, it is unsuitable at the early stages of design development. For this task, we developed a simplified numerical analysis method. The obtained results validated by comparison with the available test data and with more detailed nonlinear analysis.
Dependence of failure envelope on strain rate for unidirectional CFRP
Authors: Liu Hao , Dumansky A M , Alimov M A
Published: August 2021

Abstracts

A unidirectional carbon/epoxy composite was taken as the research subject for analysis of its strength with strain-rate effect. The theory can be further adapted and extended to the prediction of failure and progressive damage of unidirectional laminae under static and dynamic loadings. The significance of this theory is that it simplifies the formula of failure theory and may improve the prediction accuracy.
Study of the winding methods influence on the aramid fibers impregnation degree for high-pressure pipes manufacturing
Authors: Novikov A D , Ignatov P I , Lubyanskiy A O , Morozov S A
Published: August 2021

The purpose of this work is to compare the impregnation degree of samples made from an aramid-polyurethane composite material produced by three methods of winding. The para-aramid impregnation degree assessment was made on the basis of a microscopic examination of a sample’s section, as well as the results of determining the delamination fracture toughness of ring samples. Based on the studies, it was concluded that the best impregnation degree for para-aramid fibers is achieved in case of using binder sputtering assisted dry winding technology. This technology can be used for high-pressure flexible pipes manufacturing to increase their strength, which can lead to the product’s working pressure increasing.
Application of the friction surfacing process for the production of functional gradient layered composition
Authors: Mikheev R S
Published: August 2021

The possibility of applying the friction surfacing process for the production of functional gradient layered compositions for tribotechnical purposes has been considered. The influence of technological parameters of the friction surfacing process: the rod rotation frequency, the longitudinal linear speed of the rod movement and the method of the substrate surface preparation on the deposited layer formation has been shown.
Modeling basalt fibers wetting processes used in the basalt rebar production
Authors: Orlov M A , Nelyub V A , Kalinnikov A N , Borodulin A S
Published: August 2021

The article presents the results of experimental and analytical study of basalt fibers wetting processes with epoxy binders, carried out to improve the quality of basalt rebar. It is revealed that the obtained model of basalt fiber impregnation allows determining the parameters of the binder flow in the porous structure of the monofilament bundle. Numerical results of evaluation of basalt fibers wetting with epoxy binders are presented and their rheological properties are determined.
New effective lubricants for continuous basalt fibers
Authors: Sokolov G S , Shakirov K M , Nelyub V A
Published: August 2021

Abstracts

Trends in the production of new lubricants compositions for basalt and glass fibers are presented. The results of purposeful development of lubricants recipes for basalt fibers that provide high adhesive strength with the epoxy binder, minimal damage during winding and subsequent processing into technical fabrics are given.
Modeling of thermal stresses in thin-walled composite structures with phase transformation
Authors: Dimitrienko Yu I , Sborschikov S V , Egoleva E S , Yakovlev D O
Published: August 2021

An asymptotic theory modified version for calculating thin elastic multilayer plates made of high-temperature composites with multistage phase transformations, considering the composites shear characteristics finite values has been developed. Proposed in this work method version does not contain any assumptions about the kind of the unknown functions and allows ones to find all 6 stress tensor components while ensuring the high mathematical accuracy that symbolic for asymptotic method. Using the developed model, it became possible to calculate temperature non-stationary field and thermal stresses in thin multilayer plates of fabric composite materials on an inorganic binder. For material properties calculation were used multiscale averaging method and finite element modeling for periodical cells. Some change stresses numerical simulation results for composite plate during heating and loading are given.
Optimization of the curing modes of three-layer honeycomb panels
Authors: Yanyang Chen , Malysheva G V
Published: August 2021

In this paper, a method of determining rational regimes of the process of curing structures made of polymer composite materials and honeycomb filler was developed. The subject of the study was a three-layer panel where the top and bottom layers were made from carbon fiber, while the honeycomb filler was made from aluminum foil. The filler was bonded to the top and bottom layers with epoxy film adhesive. Using numerical simulation, temperature state, curing degree, and heat generation rate of all the elements of the three-layer panel were determined. The simulations revealed that the process of curing the considered honeycomb structure was uneven due to uneven temperature distribution. The optimal process modes ensuring the gradients of the degree of cure were established.
Baseline Test Suite Construction of Smoke Test for Extreme Programming
Authors: Tanli Mengqing , Zhang Ying , Jiang Yan , Wang Yulin
Published: August 2021

This paper proposed an approach of construction of baseline test suite in smoke test for extreme programming. According to our investigation, the baseline test suite should firstly embody the thinking of “data-centerlization”, and the baseline test suite in smoke test should be conducted in terms of the true application scheme, so this baseline test suite should be the calibration marking for testing and verification of a baseline product version. As a typical example, in the procedure of construction in smoke test of Product Quality Monitoring Software, data accuracy, kinds of control chart, data range, typical application situation, and further requirement were taken into consideration. In order to improve the testing efficiency and to avoid mistakes, a loading kit was developed.
Competitive Dynamics in Strategic Management
Authors: Giachetti Claudio , Dagnino Giovanni Battista
Published: August 2021

Competitive dynamics inquiry originates from a sequence of attacks and counterattacks among firms in an industry. Firms attack and respond to attacks of rivals in order to strengthen or defend their competitive position within their competitive space. Competitive dynamics research is thus centered on the analysis of how the firm’s actions affect rivals’ reactions and performance. Actually, the nature of competitive dynamics research is the open recognition that firm strategies are “dynamic”: Strategic actions initiated by one firm may trigger a series of actions among rival firms. The new competitive environment in many industries has generated the inception of furious competition, emphasizing flexibility, speed, and innovation in response to fast-changing technological and institutional conditions and temporary competitive advantages.

The key constructs and the intellectual roots of competitive dynamics (i.e., Schumpeter’s theory of creative destruction and industrial organization economics and related oligopoly theories) offer some practical examples of industry and firm cases where competitive dynamics have found their main applications.

The relevant underpinnings of the awareness–motivation–capability (AMC) framework provide an integrative model of the key behavioral drivers that shape a competitive actions and responses framework (i.e., the factors influencing the firm’s awareness of the context; the factors inducing or impeding the motivation of firms to respond to competitors’ action; and the capability-based factors affecting the firm’s ability to undertake actions), the three key attributes (i.e., the specific actions of firms in the industry, the firm’s competitive interdependence, and the antecedents and performance implications of firms’ competitive actions and reactions), and the three main levels of analysis used in competitive dynamics literature (i.e., action-level studies, business-level studies, and corporate-level studies).

Some insights regarding the relationship between dynamic competition and the sources of temporary competitive advantage, coopetition dynamics, as well as the kind of accelerated competition epitomizing early 21st-century digital dynamics settings update the traditional competitive dynamics flavor, as they are connected with firms’ strategic interaction and the pursuit of temporary advantages.
Holistic Leader(ship) Development: An Integrative Process Model of Leader and Leadership Development
Authors: Schwartz H. Michael , Khatija Pooja , Bilimoria Diana
Published: August 2021

The question of how to efficiently, holistically, and successfully develop leaders has been the focus of scholars and practitioners for several decades. Embedding the process of leader development in organizational contexts allows participants to develop and apply leadership knowledge, skills, and identity awareness. Embeddedness facilitates the holistic integration of the interactive processes of leader development (which focuses on increasing the leadership capacity of an individual) and leadership development (which focuses on increasing the leadership capacity of an organization), which is referred to in this article as leader(ship) development (LD). Two sub-processes involved in LD (i.e., general and situational identity development and knowledge/skill/social capital development) and four mechanisms of embeddedness that facilitate holistic LD (i.e., leader identity integration, opportunities to learn and develop in the organization, organizational support and feedback, and helping relationships) will be described. A discussion on the ways by which management education pedagogy can integrate and facilitate embeddedness and provide guidance for future research will follow.
Careless Responding and Insufficient Effort Responding
Authors: Huang Jason L. , Wang Zhonghao
Published: August 2021

Careless responding, also known as insufficient effort responding, refers to survey/test respondents providing random, inattentive, or inconsistent answers to question items due to lack of effort in conforming to instructions, interpreting items, and/or providing accurate responses. Researchers often use these two terms interchangeably to describe deviant behaviors in survey/test responding that threaten data quality. Careless responding threatens the validity of research findings by bringing in random and systematic errors. Specifically, careless responding can reduce measurement reliability, while under specific circumstances it can also inflate the substantive relations between variables. Numerous factors can explain why careless responding happens (or does not happen), such as individual difference characteristics (e.g., conscientiousness), survey characteristics (e.g., survey length), and transient psychological states (e.g., positive and negative affect). To identify potential careless responding, researchers can use procedural detection methods and post hoc statistical methods. For example, researchers can insert detection items (e.g., infrequency items, instructed response items) into the questionnaire, monitor participants’ response time, and compute statistical indices, such as psychometric antonym/synonym, Mahalanobis distance, individual reliability, individual response variability, and model fit statistics. Application of multiple detection methods would be better able to capture careless responding given convergent evidence. Comparison of results based on data with and without careless respondents can help evaluate the degree to which the data are influenced by careless responding. To handle data contaminated by careless responding, researchers may choose to filter out identified careless respondents, recode careless responses as missing data, or include careless responding as a control variable in the analysis. To prevent careless responding, researchers have tried utilizing various deterrence methods developed from motivational and social interaction theories. These methods include giving warning, rewarding, or educational messages, proctoring the process of responding, and designing user-friendly surveys. Interest in careless responding has been growing not only in business and management but also in other related disciplines. Future research and practice on careless responding in the business and management areas can also benefit from findings in other related disciplines.
Masculinities and Teacher Education
Authors: Hucks Darrell Cleveland
Published: August 2021

Teachers’ values and beliefs shape learning environments and reinforce and support their expectations of students’ behaviors. Overtime, students’ behavior undergoes a norming process that influences their understanding of gender roles and gender identity. While there have been political shifts since the early 1980s around gender roles; for many in 2021 these traditional dichotomous notions of gender roles for boys and girls still exist in schools. Many boys are still encouraged to be tough, strong, and emotionally devoid of feelings. For girls, many are encouraged to be polite, sweet, and emotional. Boys are still given a pass for being aggressive, and it is still quite acceptable for girls to be passive. This non-inclusive gender binary continues to damage us as adults and promotes behaviors that do not allow for the complexities regarding gender identity, and then add the factor of race to the mix, and it gets even more complicated and, all of this left unchallenged, can lead to toxic behavior. Various examples of toxic masculinity can be found in the now readily available videos of police officers’ negative engagement with people of color around the globe. Teachers still have tremendous opportunities to intervene and educate students at all levels in ways that embrace difference and create a more empathetic society—will they do it? And what are the implications for changes that must occur in how they are prepared via teacher education programs to work with diverse learners?
Experiences of Queer Students in Residence
Authors: Jagessar Valenshia
Published: August 2021

Over the past two decades, universities have shown commitment to protecting queer students through policy provisions. Undoubtedly, these policies comfort queer students; however, students who claim queer identities still experience unique challenges that often lead to an inability to reach their full academic potential. Internationally, queer students experience different levels of discrimination: sometimes verbal, psychological, and physical. In South Africa, queer students experience systematic exclusion in everyday campus life. Given this context, it is necessary to find alternative ways to forge spaces for diverse existence; universities can create one of those spaces. Transformation in South African universities should be reflected in all aspects of the universities. As such, university residences are significant spaces in which students spend most of their time and begin to explore their identities. However, scholarship is often limited to the experiences of queer students at university at the expense of how these experiences shape their professional identities. Therefore, there is a need to explore students’ experiences living in university residences and to understand how these experiences shape their professional identities.