bluuebunny/crossref_metadata_2025 huggingface dataset:
Structure and low-temperature micromechanical properties of as-cast and SPD-processed high-entropy Co25−xCr25Fe25Ni25Cx alloys
Authors: Levenets A. V. , Rusakova H. V. , Fomenko L. S. , Huang Yi , Kolodiy I. V. , Vasilenko R. L. , Tabachnikova E. D. , Tikhonovsky M. A. , Langdon T. G.
Published: July 2022

The effect of carbon additions on the structure and mechanical properties of high-entropy alloys Co25−xCr25Fe25Ni25Cx (x = 0, 1, 3, at. %) in two structural states, as-cast coarse-grained (CG) samples and nanocrystalline (NC) obtained by severe plastic deformation (SPD), was studied. The SPD was performed by high-pressure torsion at room temperature. The mechanical properties were investigated by microindentation in the temperature range of T = 77−300 K. It was found that in the as-cast state, all alloys had a dendritic microstructure and an inhomogeneous distribution of elements. At x = 0 and x = 1, the dendrites were enriched in iron and nickel, and the interdendrite regions were enriched in chromium. At x = 3, in the interdendrite regions, a eutectic consisting of a multicomponent matrix and fine eutectic dendrites of M7C3 carbide, where M is predominantly chromium, was formed. The main phase in alloys had an fcc lattice, while the solubility of carbon in it was about 1 at. %. SPD led to the effective refinement of the microstructure (the size of the coherent scattering regions was about 30−50 nm), to an increase in the dislocation density up to (1−1.5)⋅1015 m−2 and to an increase in the concentration of stacking faults. The microhardness of CG alloys at room temperature increased monotonically with increasing carbon concentration, while in NC alloys the maximum microhardness HV was achieved at 1 at. % of carbon. The reason for this anomalous behavior of the microhardness of NC alloys is an increase in the grain size and a decrease in the dislocation density in the alloy with x = 3 compared to the alloy with x = 1. As the temperature decreased from room temperature to the temperature of liquid nitrogen, the microhardness of CG and NC alloys increased by about 1.5−1.7 and 1.2−1.5 times, respectively, which indicates the thermally-activated nature of plastic deformation under the indenter. The results obtained indicate that the main role in the hardening of the CG alloys Co25−xCr25Fe25Ni25Cx is due to solid solution and dispersion hardening, while in NC alloys it is hardening due to a decrease in the grain size (according to the Hall-Petch relation) and an increase in the dislocation density (according to the Taylor relation).
Short Notice: Metal-insulator transition in single crystals Y1−zPrzBa2Cu3O7−δ
Authors: Khadzhai G. Ya. , Solovjov A. L. , Panchenko N. G. , Vovk M. R. , Vovk R. V.
Published: July 2022

The aim was to conduct comparative studies of the evolution of conductivity along and across the base ab plane in Y1−zPrzBa2Cu3O7−δ single crystals at different degrees of praseodymium doping in a wide range of concentrations 0≤z≤0.5. It is established that the increase in the degree of praseodymium doping in samples Y1−zPrzBa2Cu3O7−δ leads to increased effects of localization and implementation in the system of metal–insulator type transition, which always precedes the superconducting transition. Increasing the concentration of praseodymium leads to a significant shift in the beginning of the metal–insulator transition at the low temperature region.
Peering into the past and future of cochlear implants as they aid over one million users
Authors: Thompson Avery
Published: July 2022

Looking back at the history of cochlear implant development and towards a roadmap to the future.
Femtosecond laser-induced sub-wavelength plasma inside dielectrics: I. Field enhancement
Authors: Ardaneh Kazem , Meyer Remi , Hassan Mostafa , Giust Remo , Morel Benoit , Couairon Arnaud , Bonnaud Guy , Courvoisier Francois
Published: July 2022

The creation of high-energy-density (≳106 joules per cm3) over-critical plasmas in a large volume has essential applications in the study of warm dense matter, being present in the hot cores of stars and planets. It was recently shown that femtosecond Bessel beams enable creating over-critical plasmas inside sapphire with sub-wavelength radius and several tens of micrometers in length. Here, the dependence of field structure and absorption mechanism on the plasma density transverse profile are investigated by performing self-consistent Particle-In-Cell (PIC) simulations. Two limiting cases are considered: one is a homogeneous step-like profile that can sustain plasmon formation, and the second is an inhomogeneous Gaussian profile, where resonance absorption occurs. Comparing experimental absorption measures to analytical predictions allows determining the plasma parameters used in PIC simulations. The PIC simulation results are in good agreement with experimental diagnostics of total absorption, near-field fluence distribution, and far-field radiation pattern. We show that in each case, an ambipolar field forms at the plasma surface due to the expansion of the hot electrons and that electron sound waves propagate into the over-critical region.
Toward controllable Si-doping in oxide molecular beam epitaxy using a solid SiO source: Application to
β
-Ga2O3
Authors: Ardenghi A. , Bierwagen O. , Falkenstein A. , Hoffmann G. , Lähnemann J. , Martin M. , Mazzolini P.
Published: July 2022

The oxidation-related issues in controlling Si doping from the Si source material in oxide molecular beam epitaxy (MBE) are addressed by using its solid suboxide, SiO, as an alternative source material in a conventional effusion cell. Line-of-sight quadrupole mass spectrometry of the direct SiO-flux (ΦSiO) from the source at different temperatures (TSiO) confirmed SiO molecules to sublime with an activation energy of 3.3 eV. The TSiO-dependent ΦSiO was measured in vacuum before and after subjecting the source material to an O2-background of 10−5 mbar (typical oxide MBE regime). The absence of a significant ΦSiO difference indicates negligible source oxidation in molecular O2. Mounted in an oxygen plasma-assisted MBE, Si-doped β-Ga2O3 layers were grown using this source. The ΦSiO at the substrate was evaluated [from 2.9 × 109 cm−2 s−1 (TSiO = 700 °C) to 5.5 × 1013 cm−2 s−1 (TSiO = 1000 °C)] and Si-concentration in the β-Ga2O3 layers measured by secondary ion mass spectrometry highlighting unprecedented control of continuous Si-doping for oxide MBE, i.e., NSi from 4 × 1017 cm−3 (TSiO = 700 °C) up to 1.7 × 1020 cm−3 (TSiO = 900 °C). For a homoepitaxial β-Ga2O3 layer, a Hall charge carrier concentration of 3 × 1019 cm−3 in line with the provided ΦSiO (TSiO = 800 °C) is demonstrated. No SiO-incorporation difference was found between β-Ga2O3(010) layers homoepitaxially grown at 750 °C and β-Ga2O3(−201) heteroepitaxial layers grown at 550 °C on c-plane sapphire. However, the presence of activated oxygen (plasma) resulted in partial source oxidation and related decrease in doping concentration (particularly at TSiO < 800 °C), which has been tentatively explained with a simple model. Degassing the source at 1100 °C reverted this oxidation. Concepts to reduce source oxidation during MBE-growth are referenced.
Homoclinic orbits in three-dimensional continuous piecewise linear generalized Michelson systems
Authors: Li Zhengkang , Liu Xingbo
Published: July 2022

In this paper, we investigate the homoclinic orbits for the three-dimensional continuous piecewise linear generalized Michelson systems via analytical methods and numerical simulation. Based on the Poincaré map and invariant manifold theory, we discuss the existence of homoclinic orbits connecting the saddle-focus equilibrium. Finally, numerical simulations are presented to illustrate our results.
High thermoelectric performance induced by strong anharmonic effects in monolayer (PbX)2 (X = S, Se, Te)
Authors: Jia Pin-Zhen , Xie Zhong-Xiang , Deng Yuan-Xiang , Zhang Yong , Tang Li-Ming , Zhou Wu-Xing , Chen Ke-Qiu
Published: July 2022

Enhanced thermoelectric performance is restricted greatly by the interaction of various transport parameters, and this bottleneck urgently requires a solution. In this paper, first-principles calculations and Boltzmann transport theory are used to study the thermoelectric performance of two-dimensional (PbX)2 (X=S,Se,Te) monolayers, and it is found that the thermoelectric performance can be enhanced significantly by applying a biaxial tensile strain. The room-temperature ZT values of the p-type (PbS)2, (PbSe)2, and (PbTe)2 in zigzag (armchair) directions are boosted as high as 1.97 (1.35), 2.26 (1.31), and 2.45 (1.59), respectively. The results show that it is mainly attributed to the significantly reduced phonon thermal conductivity. Moreover, the sharply reduced phonon thermal conductivity is mainly due to the enhancement of the phonon scattering rate caused by strong phonon anharmonicity. In addition, the excellent ZT value of the p-type (PbX)2 (X=S, Se, Te) monolayer exhibits their potential application in the thermoelectric field, and the external strain has a good prospect in enhancing the thermoelectric performance.
Solar organic Rankine cycle—Parametric analysis based on exergy vs energy approaches
Authors: N Samuel , A Srinath , Sharma Noble , Tammana Anup Kumar , M Shameer Basha
Published: July 2022

Solar thermal electricity generation is one of the encouraging technologies for reducing scarcity of electricity worldwide in a renewable and sustainable manner. Solar organic Rankine cycles (SORCs) are sustainable and an eco-friendly means of power production at low- and medium-heat source temperatures. The proposed system includes a parabolic trough collector based solar system, which operates with Therminol VP-1 oil, a two-tank direct thermal energy storage unit, and an organic Rankine cycle (ORC) operates with a working fluid Toluene. Improvement in efficiencies of components has a cascading benefit in the performance of SORC, operating costs, and payback period. A comparative energy and exergy analysis study is performed to assess the thermodynamic performance of subcritical non-recuperative solar organic Rankine cycle on the basis of heat source temperatures and ORC operating parameters. Iterative procedure is adapted in the analysis to find optimal operating parameters to maximize efficiency. Maximum energetic and exergetic efficiencies of SORC are calculated at various optimal T5 and pevp. Variations of optimal mass flow rate values with respect to time and ηI, ηII with respect to heat source temperatures are plotted. In all, the energy efficiency of the overall system remained almost the same, when the proposed system is operated at the exergy-based vs energy-based optimal operating conditions. However, significant enhancement of 6.61% and 12.42% in exergetic efficiency of ORC and overall system, respectively, are observed when SORC operates at exergy-based optimal operating conditions.
A nonlinear memductance induced intermittent and anti-phase synchronization
Authors: Paul Asir M. , Sathiyadevi K. , Philominathan P. , Premraj D.
Published: July 2022

We introduce a model to mimic the dynamics of oscillators that are coupled by mean-field nonlinear memductance. Notably, nonlinear memductance produces dynamic nonlinearity, which causes the direction of coupling to change over time. Depending on the parameters, such a dynamic coupling drives the trajectory of oscillators to a synchronization or anti-synchronization manifold. Specifically, depending on the forcing frequency and coupling strength, we find anti-phase and intermittent synchronization. With the increase in coupling magnitude, one can observe a transition from intermittent synchronization to complete synchronization through anti-phase synchronization. The results are validated through numerical simulations. The hypothesis has a huge impact on the study of neuronal networks.
Conductive domain walls in x-cut lithium niobate crystals
Authors: Zhang Yuchen , Qian Yuezhao , Jiao Yuejian , Wang Xiaojie , Gao Feng , Bo Fang , Xu Jingjun , Zhang Guoquan
Published: July 2022

Conductive ferroelectric domain walls have been the focus of intensive studies in nanoelectronics due to their promising electronic properties. Here, both head-to-head and tail-to-tail domain walls with a large inclination angle (≈90°) were fabricated on the surface of x-cut nominally pure congruent lithium niobate crystals. Our results show that both types of domain walls are conductive, while the conductivity of the head-to-head domain walls is larger than that of the tail-to-tail domain walls by about two orders of magnitude at the same inclination angle of domain walls.
The enhancement of DNA fragmentation in a bench top ultrasonic water bath with needle-induced air bubbles: Simulation and experimental investigation
Authors: Sun Lin , Liu Yang , Lehnert Thomas , Gijs Martin A. M. , Li Songjing
Published: July 2022

Shearing DNA to a certain size is the first step in many medical and biological applications, especially in next-generation gene sequencing technology. In this article, we introduced a highly efficient ultrasonic DNA fragmentation method enhanced by needle-induced air bubbles, which is easy to operate with high throughput. The principle of the bubble-enhanced sonication system is introduced and verified by flow field and acoustic simulations and experiments. Lambda DNA long chains and mouse genomic DNA short chains are used in the experiments for testing the performance of the bubble-enhanced ultrasonic DNA fragmentation system. Air bubbles are an effective enhancement agent for ultrasonic DNA fragmentation; they can obviously improve the sound pressure level in the whole solution, thus, achieving better absorption of ultrasound energy. Growing bubbles also have a stretched function on DNA molecule chains and form a huge pressure gradient in the solution, which is beneficial to DNA fragmentation. Purified λDNA is cut from 48.5 to 2 kbp in 5 min and cut to 300 bp in 30 min. Mouse genomic DNA (≈1400 bp) decreases to 400 bp in 5 min and then reduces to 200 bp in 30 min. This bubble-enhanced ultrasonic method enables widespread access to genomic DNA fragmentation in a standard ultrasonic water bath for many virus sequencing demands even without good medical facilities.
Aerosol generation from tear film during non-contact tonometer measurement
Authors: Zhou Qin , Shang Xinglong , Chen Xiaodong , Chen Yanyan , Hu Guoqing
Published: July 2022

Aerosols, generated and expelled during common human physiological activities or medical procedures, become a vital carrier for the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). During non-contact intraocular pressure measurements, aerosols can be produced from the tear film on eyes and potentially convey the SARS-CoV-2 in tears, creating a high risk for eye care practitioners and patients. Herein, we numerically investigate deformation and fragmentation of the tear films with various thicknesses and surface tensions that are impinged by an air jet. Evolution of the tear films manifests several types of breakup mechanisms, including both the bag breakup and ligament breakup of tear film on the eyeball, the ligament breakup of tear film on the eyelid margin, and the sheet breakup near the eyelid margin. The sheet near the eyelid margin is critical for generating large droplets and can be formed only if the jet velocity is high enough and the film is sufficiently thick. A criterion based on Weber number and capillary number is proposed for the breakup of tear film into droplets in which three regions are used to classify the film evolution. Our results indicate that eyes with excessive tears have a greater probability of generating aerosols than eyes under normal conditions. We recommend that enhanced protections should be adopted upon measurement for the patients with watery eyes, and the time interval between two adjacent measurements for the same individual should be also prolonged during the COVID-19 pandemic.
The properties of a tunable terahertz filter based on a photonic crystal with a magnetized plasma defect layer
Authors: Almawgani Abdulkarem H. M. , Alhamss Dana N. , Taya Sofyan A. , Colak Ilhami , Sharma Arvind , Alhawari Adam R. H. , Patel Shobhit K.
Published: July 2022

Tunable terahertz (THz) filtering properties of a single channel filter are investigated. The filter structure is based on a defective photonic crystal. The defect layer is assumed as a magnetized plasma medium. The photonic crystal has the structure of (Dielectric–Dielectric)L Plasma (Dielectric–Dielectric)L, where L is the number of unit cells on both sides of the plasma layer. The tunability of the defect mode is studied for various magnetic fields, plasma densities, and thicknesses of the plasma layer. We found that as the applied magnetic field increases, the defect modes shift to a higher frequency. Moreover, the defect modes shift to a shorter frequency as the plasma density or the plasma layer thickness increases. This article provides the theoretical basis for designing a tunable filter or a sensor depending on the parameters used at the THz range.
Australian health policies related to diagnostic imaging: too much of a good thing?
Authors: Docking Sean , Haddock Rebecca , Buchbinder Rachelle
Published: July 2022

Diagnostic imaging is increasingly being used in Australia to aid clinician diagnostic and therapeutic decision-making. There is concern that this increased use represents an overconsumption of inappropriate health services, which wastes finite resources and may cause direct or indirect harm to the patient. Australian health policies have primarily focused on increasing patient access to diagnostic imaging. While these policies address inequitable access and may lead to timely diagnosis and improved health outcomes, these benefits have not been weighed against the unintended harms. This perspective article will explore the unintended consequences of increasing access to diagnostic imaging as well as provide potential solutions to improve the effectiveness of policies in this area.
Understanding
Authors: Salgado Vanina G. , Grossi Mariana A. , Ribeiro Rogério N. , Proença Carolyn E. B. , Gutiérrez Diego G.
Published: July 2022

The South American genus Praxelis Cass. (Asteraceae, Eupatorieae) includes 18 species and is the second-largest genus of subtribe Praxelinae. It is distributed from Colombia, Venezuela and the Guianas, to central Argentina, southern Brazil and north-western Uruguay. Over the past 40 years, one species, P. clematidea, has invaded several countries around the world. To understand Praxelis and its species, this study provides an updated taxonomy with the re-establishment of P. urticeafolim var. nanum as a synonym of P. ostenii, 16 lectotypifications, clarification of morphology and geographical distribution, brief descriptions, and the first key to all the species in the genus.
Social norms and dishonesty across societies
Authors: Aycinena Diego , Rentschler Lucas , Beranek Benjamin , Schulz Jonathan F.
Published: July 2022

Social norms have long been recognized as an important factor in curtailing antisocial behavior, and stricter prosocial norms are commonly associated with increased prosocial behavior. In this study, we provide evidence that very strict prosocial norms can have a perverse negative relationship with prosocial behavior. In laboratory experiments conducted in 10 countries across 5 continents, we measured the level of honest behavior and elicited injunctive norms of honesty. We find that individuals who hold very strict norms (i.e., those who perceive a small lie to be as socially unacceptable as a large lie) are more likely to lie to the maximal extent possible. This finding is consistent with a simple behavioral rationale. If the perceived norm does not differentiate between the severity of a lie, lying to the full extent is optimal for a norm violator since it maximizes the financial gain, while the perceived costs of the norm violation are unchanged. We show that the relation between very strict prosocial norms and high levels of rule violations generalizes to civic norms related to common moral dilemmas, such as tax evasion, cheating on government benefits, and fare dodging on public transportation. Those with very strict attitudes toward civic norms are more likely to lie to the maximal extent possible. A similar relation holds across countries. Countries with a larger fraction of people with very strict attitudes toward civic norms have a higher society-level prevalence of rule violations.
Biogeochemical fingerprinting of magnetotactic bacterial magnetite
Authors: Pérez-Huerta Alberto , Cappelli Chiara , Jabalera Ylenia , Prozorov Tanya , Jimenez-Lopez Concepcion , Bazylinski Dennis A.
Published: July 2022

Biominerals are important archives of the presence of life and environmental processes in the geological record. However, ascribing a clear biogenic nature to minerals with nanometer-sized dimensions has proven challenging. Identifying hallmark features of biologically controlled mineralization is particularly important for the case of magnetite crystals, resembling those produced by magnetotactic bacteria (MTB), which have been used as evidence of early prokaryotic life on Earth and in meteorites. We show here that magnetite produced by MTB displays a clear coupled C–N signal that is absent in abiogenic and/or biomimetic (protein-mediated) nanometer-sized magnetite. We attribute the presence of this signal to intracrystalline organic components associated with proteins involved in magnetosome formation by MTB. These results demonstrate that we can assign a biogenic origin to nanometer-sized magnetite crystals, and potentially other biominerals of similar dimensions, using unique geochemical signatures directly measured at the nanoscale. This finding is significant for searching for the earliest presence of life in the Earth’s geological record and prokaryotic life on other planets.
Relay interpreting
Authors: Pöchhacker Franz
Published: July 2022

The unique features of interpreting as a situated process and performance to enable communication in real time
make relay interpreting a particularly complex manifestation of indirect translation and a rich area of investigation. Even so,
the great potential of relay interpreting as an object of inquiry in Translation and Interpreting Studies has remained largely
untapped. This article seeks to map out the conceptual territory of relay interpreting as indirect translation with reference to
relevant factors and features. The analysis highlights the great diversity of scenarios that can be subsumed under the heading of
relay interpreting with reference to such key parameters as mode, modality, policy, linguality, multimodality, and technology.
The – regrettably modest – state of the art is reviewed with regard to types of research, topics, and methods; and some areas of
special interest, such as Deaf relay interpreting and speech-to-text interpreting relying on speech recognition technology, are
discussed for their potential to extend the scope of indirect translation to include intralingual and intermodal as well as
technology-based manifestations.
Translational phenomena in the news
Authors: Davier Lucile
Published: July 2022

Studies of news translation and indirect translation have challenged classical concepts of Translation Studies, but the two subfields have taken separate paths. This article applies Assis Rosa, Pięta, and Bueno Maia’s (2017b) classification of indirect translation to data collected via workplace studies conducted in two multilingual news agencies based in Switzerland and one monolingual broadcaster based in Canada. Illustrative examples are provided of the first six types of (in)direct translation in the classification. This typology allows for the inclusion of phenomena that may have been previously disregarded as translation, such as oral mediations and transfers from public-relations agencies to news agencies and other media outlets. However, news translation is a borderline case of translation that pushes Assis Rosa, Pięta, and Bueno Maia’s (2017b) classification to its limits because of the centrality of reported speech in news stories. Indirect translation seems to be able to bridge various subfields of Translation Studies.
Carrier density variation and linewidth enhancement factor in optically injection locked semiconductor lasers
Authors: Al-Hosiny Najm M
Published: July 2022

We theoretically investigate the behavior of carrier density variation in optically injected semiconductor lasers when varying the linewidth enhancement factor. The variation of carrier appears independent of the LEF in the positive detuning side, while decreased in the negative detuning side with any growth in the LEF. This variation is found to be enhanced when the injection level is boosted.
When null energy condition meets ADM mass
Authors: Yang Run-Qiu , Li Li , Cai Rong-Gen
Published: July 2022

We give a conjecture on the lower bound of the ADM mass M by using the null energy condition. The conjecture includes a Penrose-like inequality

3
M
≥
κ


/

(
4
π
)
+



/

4
π

and the Penrose inequality

2
M
≥



/

4
π

with



the event horizon area and κ the surface gravity. Both the conjecture in the static spherically symmetric case and the Penrose inequality for a dynamical spacetime with spherical symmetry are proved by imposing the null energy condition. We then generalize the conjecture to a general dynamical spacetime. Our results raise a new challenge for the famous unsettled question in general relativity: in what general case can the null energy condition replace other energy conditions to ensure the Penrose inequality?
A partial least squares regression model based on variational quantum algorithm
Authors: Hou Yan-Yan , Li Jian , Chen Xiu-Bo , Ye Chong-Qiang
Published: July 2022

Partial least squares regression (PLSR) is an essential multivariate correlation analysis method in machine learning field. In this paper, we propose a variational quantum algorithm for partial least regression (VQPLSR). By exploring the relationship between standard basis states and optimization, we design a cost function that can train regression parameters and weight vectors simultaneously. The VQPLS requires only one copy of variables as input, which reduces the complexity of quantum circuit implementation. Compared with PLSR, the VQPLSR achieves an exponential speed-up in the independent variable dimension n and dependent variable dimension w. Simulation results show that regression parameters and weight vectors can be constructed with the error ∼10−5 for 4 × 2 dimensional variable matrix. This algorithm inspires us to explore more quantum applications in machine learning.
Study of the toxicity of high-silica porous glasses
Authors: Shevchenko D S , Rakhimova O V , Tsyganova T A
Published: July 2022

The toxicity of high-silica porous glasses in relation to Paramecium caudatum was investigated. The test results showed a generally acceptable toxicity range. The toxicity of porous glasses varies depending on the concentration and time of contact of the fine powder with water which may be is associated with the presence of sodium ions, fluoride and phosphate ions in an aqueous solutions.
Effect of different additives on the compressive strength of concrete powder based geopolymer
Authors: Udvardi Bella , Géber Róbert , Kocserha István
Published: July 2022

The aim of the research is to produce geopolymer using secondary raw materials. In this research work concrete powder has been used as a raw material for the production of geopolymers, which belongs to the group of construction and demolition waste (CDW). Beside this various additives (silica fume, aerosil, calcium –stearate, metakaolin, and lime hydrate) have been used to improve mechanical strength. In the study the compressive strength of geopolymers of different compositions (7, 28 and 90 days) was tested, and the geopolymerization processes were identified by FT-IR apparatus. Based on the measurement results the combined mixture of metakaolin and aerosil succeeded in producing the highest compressive strength (=59,64 MPa) geopolymer paste.
Luminescent hybrid materials based on organic phosphors and fluorides in the PbF2-LaF3 system
Authors: Strekalov P , Runina K , Mayakova M , Petrova O , Avetissov I
Published: July 2022

Powder hybrid materials based on 8-hydroxyquinolate lithium organic phosphor and - LaF3 inorganic fluoride matrix PbF2 have been synthesized. Hybrid materials were obtained by co-precipitation from aqueous-alcoholic solutions with ammonium fluoride under various conditions - different concentrations of precursor solutions, Pb/La ratio, and the siquensy of reagents’ mixing. All obtained hybrid materials showed effective broadband luminescence in the region of 390-500 nm. The photoluminescence intensity during reverse deposition was found to be higher than during direct deposition for different concentrations of reagents.
Model of transition zone evolution between coating and substrate under intense short thermal impulse
Authors: Knyazeva A G , Nazarenko N N
Published: July 2022

In the present work a model of the evolution of the composition of the transition zone between the material and the pre-applied coating under conditions of intense short-term thermal impulse is proposed. The pulse times are assumed to be comparable to the relaxation times of the heat and mass fluxes. This led to the need to account for finite rates of heat and mass propagation in the model, leading to hyperbolic transfer equations. The phenomena of thermodiffusion (Soret effect) and diffusive thermal conductivity (Dufour effect) and some possible chemical reactions leading to a change in the transition zone composition are also taken into account. This nonlinear model problem illustrates the necessity of the really coupled problem solution to reveal the feature of cross-effects in irreversible conditions. It was found that due to the wave heating and the wave nature of the movement of elements, chemical reactions can start during the action of a short pulse outside the heating zone expected only due to thermal conductivity.
Surface morphology of nanostructured plasma-polymer thin films deposited under dusty plasma conditions
Authors: Buršík J , Campbell A Charvátová , Havlíček M , Klapetek P , Kelarová Š , Pŕibyl R , Václavik R , Stupavská M , Buršíková V
Published: July 2022

Plasma-polymer thin films were prepared under dusty plasma conditions. Due to their nanocomposite structure, the films showed unique mechanical properties including high elastic recovery resulting in a behaviour similar to superelasticity. The work is mainly focused on the characterization of the films by means of analytical scanning electron microscopy. We observed that variation of the deposition conditions caused substantial changes of surface topography of the deposited films. Consequently, the surface free energy varied in a wide range so it was possible to prepare films with either hydrophilic or hydrophobic properties.
The influence of different types of SCMs on microstructure and macroscopic properties of cementitious materials
Authors: Kopecskó Katalin , Mlinárik Lilla
Published: July 2022

In our study, the influence of different supplementary cementitious materials (SCMs) such as metakaolins, silica fume (microsilica) or filtered coal fly ash on the performance of concrete is discussed. The effects of different types and dosages of the SCMs have been investigated. Centrilit NC (MK1) and Metaver N (mk2) type metakaolins, Microsit® 20 (MS) type filtered coal fly ash or Centrilit Fume SX (SF) silica fume suspension was chosen as the replacement for the CEM I 42.5 N-SR0 sulphate resistant Portland cement. In addition to the two-component mixtures, we also examined the behaviour of the ternary blends, i.e. the combinations of SCMs. For the experiments, mortar prisms and cylindrical mortar specimens were prepared with water to binder ratio of 0.4. The paper presents the test results performed up to two years. The compressive strengths of the mixtures were examined. The most critical property of the cement-bound materials, the chloride migration coefficient of each mixture, was determined. The microstructure of the mixtures was determined by mercury intrusion porosimetry at the age of one year. Our results indicated (i) the best compressive strength was achieved for MK2 and for MK1 with combination of SF; (ii) the pore structure is much finer in the case of MK1 mixtures compared with those of MK2 or MS mixtures; (iii) the whole most frequent pore diameter interval falls into the range of medium capillaries only in case of MK1 (10 w%), for other mixtures the large capillaries are present in different extent. The SCMs greatly influence the extent of the enhancement in chloride migration coefficients with age: the less reduction was found for the mixtures of MK1, and the highest reduction was found for mixtures of MS. There is no direct function between the compressive strength, total porosity, specific surface of porosity or chloride migration coefficients.
Properties of red-mud-based geopolymers in the light of their chemical composition
Authors: Khalaf Ali Abdulhasan , Kopecskó Katalin
Published: July 2022

Utilizing industrial waste materials such as red mud as alternatives to high emissions of CO2materials such as Portland cement will help to produce integrated sustainable construction materials. Statistical analysis has been performed on the major oxides of red mud to understand the relationship between chemical composition and properties (e.g., workability, setting time, compressive strength, etc.) of red mud-based geopolymer composite. Therefore, red mud can be a suitable binder by blending with other geopolymer source materials to achieve the desired fresh and mechanical properties. Moreover, a proposed equation has been derived on the basis of the outcomes from the literature to determine the required extra water that can compensate for the workability loss due to red mud addition.
Investigation of the Energy Absorption of the Aluminium Foam
Authors: Kertész József , Nyikes Zoltán , Pinke Péter , Kovács Tünde Anna
Published: July 2022

To assure safe traffic is a goal of the vehicle manufacturers. The car body elements are usually made from high plasticity metals whiches can deform in the case of an accident. By this deformation way, the car body absorbs the collision energy. Aluminium foam is a special material that can absorb impact energy. The authors wanted to find a rapid and simple test method to investigate the dynamic load effect for the aluminium foam. The Charpy impact test is a suitable and standardized impact test to determine the absorbed energy of the material during the fracture. In this research, the aluminium foam was tested by the Charpy impact test and compared the results with literature data to evaluate the used impact test.
Artemisia vulgaris tincture-assisted synthesis of silver nanoparticles and their antimicrobial activity
Authors: Kaur Harleen , Praakle Kristi , Rosario M. Soares , Rauwel Protima , Rauwel Erwan
Published: July 2022

The present study investigates the synthesis of silver nanoparticles (Ag NP) using Artemisia vulgaris tincture and their enhanced antimicrobial activity against different bacterial strains. The Ag NP were characterized using UV-Vis spectroscopy, FTIR, and XRD. Their antibacterial activity was also assessed against Escherichia coli, Staphylococcus aureus, Streptococcus uberis, Pseudomonas aeruginosa, Listeria monocytogenes and Corynebacterium spp. The results demonstrated that the size of the inhibition zone increased with increase in Ag NP concentration. Additionally, the type of bacterial strain also had an effect on the size of the inhibition zones.
Investigation of the ultrasonic welded stainless steel corrosion resistance
Authors: Schramkó Márton , Nyikes Zoltán , Tóth László , Kovács Tünde Anna
Published: July 2022

This article will present the ultrasonic welding technology of the stainless steel sheets, the joining with agreeing of the material science theory and metal-working rules-based executed experiments. Fusion welding is well understood and investigated in the case of steel. The ultrasonic welding in the case of metals causes different changes in the metals structure. The ultrasonic welding cause complex effect during the welding process. These effects are plastic deformation, heat, and ultrasound vibration. The goal of this research is to show the case of the experimented welded stainless steel (X5CrNi18-10) to determine the corrosion behaviour by non-destructive (visual test and microscopy) inspections. The stainless steel is sensible for all processes even that the cold working, heating and ultrasound effect. These effects can cause a decrease in the corrosion resistance of stainless steel.
Review article: Atmospheric Pressure, Water with Air, Porosity and Strength of Concrete (In memory of Professor László A Gömze)
Authors: Urakov Aleksandr L.
Published: July 2022

The review shows that the gas content in tablets and solutions of medicines can significantly change their physical and chemical properties, qualitative and quantitative characteristics of the mechanism of action of medicines when applied topically, and even allows you to turn “old” and known medicines into “new” medicines with completely new and previously unknown mechanisms of action. Therefore, artificial changes in the gas content in solid and liquid dosage forms were recommended as an original method of developing new drugs. It has been shown that this method is particularly promising for the development of new antiseptic, cosmetic and hygiene products. The fact is that the additional forced introduction of gas into a liquid or into solid through excessive pressure increases their volume, reduces their specific gravity and strength. Moreover, it allows you to “blow up” them by cold boiling. Conversely, the removal of gas from them due to vacuum reduces the volume, increases the specific gravity and strength. By analogy with the change in the physical and chemical properties of liquid and solid medicines, achieved by removing gases from them, it is proposed to reduce the porosity and volume of concrete and increase its specific weight and strength by degassing the water used for wetting cement in the concrete manufacturing process. Due to the fact that under normal conditions, the gas content in the water used for the manufacture of concrete directly depends on the atmospheric pressure, it is concluded that the production of concrete at different atmospheric pressure changes its quality. In particular, low atmospheric pressure can reduce the porosity and volume of concrete, as well as increase the specific gravity and strength of concrete. On the other hand, high air and/or gas pressure can increase the porosity and volume of concrete and reduce the concrete’s specific gravity and strength. Therefore, the amount of atmospheric pressure and/or air and/or gas pressure on concrete during its production should be included in the list of controlled indicators of concrete manufacturing technology.
Modeling of Modulus of elasticity of Nano-Composite Materials: Review and Evaluation
Authors: Kareem Sarah , S.Al-Ansari Luay , Gömze László A.
Published: July 2022

To improve the mechanical properties of polymer, the mineral particles are added to produce composite material. For example, the mineral particles are added to polymer to improve the stiffness of polymer because of the higher stiffness of mineral particles. When the micron-sized particles are used in composite usually cause a reduction in impact resistance. On the other hand, adding the nano scale minerals leads to improve the impact and wear properties of the composite materials (nanocomposites). Several factors effect on the mechanical properties of nanocomposites like adhesion between the polymer and nanoparticles. If the interfacial deboning of particles from the matrix decreases, the tensile strength of the composite could be reduced.

In this article, the micromechanical models dealing with calculating modulus of elasticity of nanocomposite are reviewed and discussed using the comparison between the results of the micromechanical models with experimental data factors effect on the modulus of elasticity of nanocomposite are matrix and filler elastic modulus, volume fraction of filler, aspect ratio of filler, maximum volumetric packing and the thickness and elastic modulus of interphone surrounding the nanoparticles and these factors are studied in each mechanical models.
Effects of hydrogen peroxide on endothelial function in three-dimensional hydrogel vascular model and regulation mechanism of polar protein Par3
Authors: Gao Hongqian , Wang Bo , Chen Ruomeng , Jin Zhen , Ren Lingxuan , Yang Jianjun , Wang Weirong , Zheng Nanbo , Lin Rong
Published: July 2022

Three-dimensional (3D) cell cultures better reflect the function of endothelial cells (ECs) than two-dimensional (2D) cultures. In recent years, studies have found that ECs cultured in a 3D luminal structure can mimic the biological characteristics and phenotypes of vascular ECs, thus making it more suitable for endothelial dysfunction research. In this study, we used a 3D model and 2D tissue culture polystyrene (TCP) to investigate the effects of cell polarity on hydrogen peroxide (H2O2)-induced endothelial dysfunction and its related mechanisms. We observed the cell morphology, oxidative stress, and barrier and endothelial function of human umbilical vein ECs (HUVECs) in 3D and 2D cultures. We then used Illumina to detect the differentially expressed genes (DEGs) in the 3D-cultured HUVEC with and without H2O2 stimulation, using clusterProfiler for Gene Ontology function enrichment analysis and Kyoto Encyclopaedia of Genes and Genomes pathway enrichment analysis of DEGs. Finally, we explored the role and mechanism of polar protein partitioning defective protein 3 (Par3) in the regulation of ECs. ECs were inoculated into the 3D hydrogel channel; after stimulation with H2O2, the morphology of HUVECs changed, the boundary was blurred, the expression of intercellular junction proteins decreased, and the barrier function of the EC layer was damaged. 3D culture increased the oxidative stress response of cells stimulated by H2O2 compared to 2D TCPs. The polarity-related protein Par3 and cell division control protein 42 were screened using bioinformatics analysis, and western blotting was used to verify the results. Par3 knockdown significantly suppressed claudin1 (CLDN1) and vascular endothelial cadherin. These results suggest that the polar protein Par3 can protect H2O2-induced vascular ECs from damage by regulating CLDN1 and VE-cadherin.
Rising temperature threatens China’s cropland
Authors: Wang Jianghao , Zhang Junjie , Zhang Peng
Published: July 2022

The rising demand for calories and protein together with urbanization, pose significant challenges to China’s food security. The determination of policy actions requires accurate estimates of climatic impacts on both crop yields (intensive margin) and cropland area (extensive margin). However, the analysis of the latter has been limited, especially in developing countries. Here, we assess the impact of temperature on land use in China by matching high-resolution satellite data on land use with daily weather data from 1980 to 2010. We find that extremely hot weather (daily average temperature above 30 °C) has a long-lasting effect on reducing cropland in China. Combining climate projections from 39 downscaled climate models, we predict that climate change is likely to reduce China’s cropland area by 2.09%–25.51% under IPCC’s slowest and fastest-warming scenarios by the end of this century. In addition, we find that non-irrigated land is more susceptible to rising temperatures in the short term; however, irrigated land is subject to a similar impact in the long term. This result suggests that the adaptive effect of irrigation could be limited under persistent rising in temperature.
The location of the Fisher zeros and estimates of y
T = 1/ν are found for the Baxter–Wu model
Authors: Monroe James L
Published: July 2022

The Fisher zeros of the Baxter–Wu model are examined for the first time and for two series of finite-sized systems, with ‘spherical’ boundary conditions, their location is found to be extremely simple. They lie on the unit circle in the complex sinh[2βJ
3] plane. This is the same location as the Fisher zeros of the square lattice Ising model with nearest neighbour interactions and Brascamp–Kunz boundary conditions. The Baxter–Wu model is an Ising model with three-site interactions, J
3, on the triangle lattice. From the leading Fisher zeros, using finite-size scaling, accurate estimates of the critical exponent 1/ν are obtained and emphasis is placed on using different variables such as exp[−2βJ
3], exp[−4βJ
3], and sinh[2βJ
3] to enhance the accuracy of estimates. Furthermore, using the imaginary parts of the leading zeros versus the real part of the leading zeros, yields different results. This is similar to results of Janke and Kenna for the nearest neighbour, Ising model on the square lattice and extends this behaviour to a multisite interaction system in a different universality class than the pair-interaction cases.
Temperature sensing using bulk and nanoparticles of Ca0.79Er0.01Yb0.2MoO4 phosphor
Authors: Singh Sachin , Kachhap Santosh , Singh Akhilesh Kumar , Pattnaik Sasank , Singh Sunil Kumar
Published: July 2022

Optical temperature sensing is widely realized by using upconversion (UC) emission in lanthanide-doped phosphors. There are various parameters that are responsible for UC intensity of the phosphor like particle shape and size, type of symmetry that exist at the site position, distribution of lanthanide ions in the phosphor, and so on. However, a comparative study of the bulk and nanostructure on the temperature sensing ability of such phosphor is rare. In the present work, we have taken Ca0.79Er0.01Yb0.2MoO4 phosphors as a model system and synthesized its bulk (via solid-state reaction method, named SCEY) and nanostructures (via solution combustion route, named CCEY). We further studied their phase, crystal structure, phonon frequency, optical excitation, and emission (upconversion & downshifting) properties. Finally, the optical temperature sensing behavior of SCEY and CCEY, in the range 305 K–573 K, have been compared. The maximum relative sensitivity of the phosphor SCEY and CCEY are 0.0061 K−1 at 305 K and 0.0094 K−1 at 299 K, respectively, while, the maximum absolute sensitivities are 0.0150 K−1 at 348 K, and 0.0170 K−1 at 398 K, respectively. We thus conclude that the temperature sensing ability of nanoparticle-based Ca0.79Er0.01Yb0.2MoO4 phosphor is better compared to its bulk phosphor.
Optimising correlative super resolution and atomic force microscopies for investigating the cellular cytoskeleton
Authors: Hargreaves Riley B , Rozario Ashley M , McCoy Thomas M , Meaney Shane P , Funston Alison M , Tabor Rico F , Whelan Donna R , Bell Toby D M
Published: July 2022

Correlative imaging methods can provide greater information for investigations of cellular ultra-structure, with separate analysis methods complementing each other's strengths and covering for deficiencies. Here we present a method for correlative applications of super resolution and atomic force microscopies, optimising the sample preparation for correlative imaging of the cellular cytoskeleton in COS-7 cells. This optimisation determined the order of permeabilisation and fixation, the concentration of Triton X-100 surfactant used and time required for sufficient removal of the cellular membrane while maintaining the microtubule network. Correlative SMLM/AFM imaging revealed the different information that can be obtained through each microscopy. The widths of microtubules and microtubule clusters were determined from both AFM height measurements and Gaussian fitting of SMLM intensity cross sections, these were then compared to determine the orientation of microtubules within larger microtubule bundles. The ordering of microtubules at intersections was determined from the AFM height profiles as each microtubule crosses the other. The combination of both microtubule diameter measurements enabled greater information on their structure to be found than either measurement could individually.