bluuebunny/crossref_metadata_2025 huggingface dataset:
A comparison study of superovulation strategies for C57BL/6J and B6D2F1 mice in CRISPR-Cas9 mediated genome editing
Authors: Zhao Xue , Huang Johnny X. , Zhang Hailong , Gong Xueyang , Dong Jinhua , Ren Hong-Lin , Liu Zengshan
Published: November 2021

Reproductive techniques such as superovulation and in vitro fertilisation (IVF) have been widely used in generating genetically modified animals. The current gold standard for superovulation in mice is using coherent treatments of equine chorionic gonadotropin (eCG) and human chorionic gonadotropin (hCG). An alternative method using inhibin antiserum (IAS) instead of eCG has been recently reported. Here, we evaluate different superovulation strategies in C57BL/6J and B6D2F1 mice. Firstly, we found that using 5-week-old C57BL/6J and 4-week-old B6D2F1 donors could achieve better superovulation outcomes. Then, we compared eCG–hCG, IAS–hCG and eCG–IAS–hCG with different dosages in both mouse strains. Significantly increased numbers of oocytes were obtained by using IAS–hCG and eCG–IAS–hCG methods. However, low fertilisation rates (36.3–38.8%) were observed when natural mating was applied. We then confirmed that IVF could dramatically ameliorate the fertilisation rates up to 89.1%. Finally, we performed CRISPR-Cas9 mediated genome editing targeting Scn11a and Kcnh1 loci, and successfully obtained mutant pups using eCG–hCG and IAS–hCG induced zygotes, which were fertilised by either natural mating or IVF. Our results showed that IAS is a promising superovulation reagent, and the efficiency of genome editing is unlikely to be affected by using IAS-induced zygotes.
The
Shh
/
Gli3
gene regulatory network precedes the origin of paired fins and reveals the deep homology between distal fins and digits
Authors: Letelier Joaquín , Naranjo Silvia , Sospedra-Arrufat Ismael , Martinez-Morales Juan Ramón , Lopez-Rios Javier , Shubin Neil , Gómez-Skarmeta José Luis
Published: November 2021

Significance

In this study, we show that the inactivation of the
gli3
gene in medaka fish results in the formation of larger dorsal and paired fins. These mutant fins display multiple radial bones and fin rays which resemble polydactyly in
Gli3
-deficient mice. Our molecular and genetic analyses indicate that the size of fish fins is controlled by an ancient mechanism mediated by SHH-GLI signaling that appeared prior to the evolutionary appearance of paired fins. We also show that the key regulatory networks that mediate the expansion of digit progenitor cells in tetrapods were already in place in the fins of the last common ancestor between ray and lobe-finned fishes, suggesting an ancient similarity between distal fins and digits.
Magmatic thickening of crust in non–plate tectonic settings initiated the subaerial rise of Earth’s first continents 3.3 to 3.2 billion years ago
Authors: Chowdhury Priyadarshi , Mulder Jacob A. , Cawood Peter A. , Bhattacharjee Surjyendu , Roy Subhajit , Wainwright Ashlea N. , Nebel Oliver , Mukherjee Subham
Published: November 2021

Significance

Understanding when and how subaerial continental crust first formed is crucial, as it likely played a critical role in establishing Earth’s habitability. Although debated, the broad consensus is that the subaerial rise of continents began ∼2.5 billion years ago and was driven by plate tectonics. Here, we integrate the igneous and sedimentary history of Archean cratons to demonstrate that stable continental landmasses started to emerge above sea level 3.3 to 3.2 billion years ago (i.e., over 700 million years earlier than most models predict). We also demonstrate that these initial episodes of continental emersion were driven by voluminous granitoid magmatism in non–plate tectonic settings that formed ∼50-km-thick, silica-rich crust, which rose above the oceans due to isostasy.
Active math and grammar learning engages overlapping brain networks
Authors: Stillesjö Sara , Karlsson Wirebring Linnea , Andersson Micael , Granberg Carina , Lithner Johan , Jonsson Bert , Nyberg Lars , Wiklund-Hörnqvist Carola
Published: November 2021

We here demonstrate common neurocognitive long-term memory effects of active learning that generalize over course subjects (mathematics and vocabulary) by the use of fMRI. One week after active learning, relative to more passive learning, performance and fronto-parietal brain activity was significantly higher during retesting, possibly related to the formation and reactivation of semantic representations. These observations indicate that active learning conditions stimulate common processes that become part of the representations and can be reactivated during retrieval to support performance. Our findings are of broad interest and educational significance related to the emerging consensus of active learning as critical in promoting good long-term retention.
Is there a dative alternation in Romanian?
Authors: Cornilescu Alexandra , Tigău Alina
Published: November 2021

Against recent claims that Romance languages lack a genuine dative alternation since they lack a genuine Prepositional Dative Construction (e.g., Pineda 2012), we bring evidence that, in Romanian, even in Recipient ditransitive constructions, datives manifest either DP or PP properties. In order to establish this result, we examine both the (internal) structure of the Romanian inflectional dative, and the prepositional dative, marked by the preposition la “at”/“to” and show that both forms require a ‘dual categorial analysis’, in order to allow licensing of their case and person features. While the default interpretation of datives in Recipient ditransitive constructions is that of DPs (whence the possibility of clitic doubling (CD)), there is a class of contexts (e.g., double datives, featuring a possessive dative and a Goal/Recipient dative), where the Recipient must be projected as a PP, since otherwise it cannot be licensed. The dual categorization of the Recipient as a DP/PP proves the existence of a genuine dative alternation in Romanian.
Dative clitics in Romanian ditransitives
Authors: Tigău Alina , von Heusinger Klaus
Published: November 2021

This chapter presents a novel analysis for Romanian ditransitives. Based on empirical findings, we develop a derivational account building on the internal make-up of the two internal arguments. The account departs from the observation that clitic doubling (CD) of indirect objects (IO) and Differential Object Marking (DOM) of direct objects (DO) interact in an interesting and unexpected way: while unmarked DOs bind IOs irrespective of Clitic Doubling of IOs, counterparts where DOM-ed DOs bind CD-ed IOs are degraded; however, CD-ed+DOM-ed DOs fare much better. These facts seem to arise as a consequence of the interaction between DOM-ed DOs and CD-ed IOs which have similar internal make-up (they both carry a [Person] feature) and compete for the same probe, with the closer blocking agreement of the other. When DO cliticizes, these intervention effects no longer arise.
New metric reconstruction scheme for gravitational self-force calculations
Authors: Toomani Vahid , Zimmerman Peter , Spiers Andrew , Hollands Stefan , Pound Adam , Green Stephen R
Published: November 2021

Inspirals of stellar-mass objects into massive black holes will be important sources for the space-based gravitational-wave detector LISA. Modelling these systems requires calculating the metric perturbation due to a point particle orbiting a Kerr black hole. Currently, the linear perturbation is obtained with a metric reconstruction procedure that puts it in a ‘no-string’ radiation gauge which is singular on a surface surrounding the central black hole. Calculating dynamical quantities in this gauge involves a subtle procedure of ‘gauge completion’ as well as cancellations of very large numbers. The singularities in the gauge also lead to pathological field equations at second perturbative order. In this paper we re-analyze the point-particle problem in Kerr using the corrector-field reconstruction formalism of Green, Hollands, and Zimmerman (GHZ). We clarify the relationship between the GHZ formalism and previous reconstruction methods, showing that it provides a simple formula for the ‘gauge completion’. We then use it to develop a new method of computing the metric in a more regular gauge: a Teukolsky puncture scheme. This scheme should ameliorate the problem of large cancellations, and by constructing the linear metric perturbation in a sufficiently regular gauge, it should provide a first step toward second-order self-force calculations in Kerr. Our methods are developed in generality in Kerr, but we illustrate some key ideas and demonstrate our puncture scheme in the simple setting of a static particle in Minkowski spacetime.
Scanning tunneling microscopy study of CaF2 on Si(111): observation of metastable reconstructions
Authors: Galbiati Miriam , Scarselli Manuela , Arciprete Fabrizio , De Crescenzi Maurizio , Camilli Luca
Published: November 2021

The deposition of calcium fluoride (CaF2) on Si(111) at temperatures above 570 °C has been studied with scanning tunneling microscopy. At such temperatures, triangular calcium fluoride islands are formed both on terraces and along the phase domain boundaries of the (7 × 7) reconstruction of the Si(111) substrate. In addition to the formation of islands, we observe that CaF2 molecules react with the substrate inducing large areas of its surface to reconstruct into (√3 × √3) and c(2 × 4) phases. Upon annealing at 600 °C, the abovementioned areas of (√3 × √3) and c(2 × 4) turn into the stable (3 × 1) phase upon desorption of fluorine. Calcium fluoride islands are stable at this temperature. Depositions of calcium fluoride performed with Si substrate kept at higher temperature, namely at 680 °C, lead directly to the formation of (3 × 1) phase due to the complete desorption of fluorine, without passing through the formation of the metastable (√3 × √3) and c(2 × 4) phases. If CaF2/Si(111) is brought at even higher temperatures, Ca also starts desorbing and the (7 × 7)-Si(111) reconstruction can eventually be restored.
VMD based trigonometric entropy measure: a simple and effective tool for dynamic degradation monitoring of rolling element bearing
Authors: Kumar Anil , Gandhi C P , Vashishtha Govind , Kundu Pradeep , Tang Hesheng , Glowacz Adam , Shukla Rajendra Kumar , Xiang Jiawei
Published: November 2021

Early identification of rolling element defects is always a topic of interest for researchers and the industry. For early fault identification, a simple and effective dynamic degradation monitoring method using variational mode decomposition (VMD) based trigonometric entropy measure is developed. First, vibration signals are obtained and are further decomposed using VMD to obtain various frequency modes. Second, a trigonometric entropy measure is developed to monitor the dynamic change occurring in the health of bearing. Third, trigonometric entropy measure of various VMD modes is computed. Fourth, the variance of measure is computed and two modes having the highest variance are selected for principal component analysis (PCA). Thereafter, PCA of selected measures is carried out. Finally, dynamic degradation monitoring is carried out by observing the trend in the principal component having the highest diverse information. The testing of newly developed VMD based trigonometric entropy measure is carried out on the two different types of data set. One is from XJTU-SY Bearing datasets and another is from the Centre for Intelligent Maintenance Systems. The experimental study reveals that the proposed method is capable of raising the alarm about the initiation of defects at a very early stage. Compared to existing indicators such as kurtosis, RMS, and Shannon entropy, the proposed method is superior while carrying out defect degradation monitoring.
Development of a dynamic pressure standard of low amplitudes and frequencies
Authors: Díaz Tey Alberto Juan , Govaere Vicarioli Georges
Published: November 2021

The height of the gravitational wave is an influential magnitude in the estimation of its energy content, a very important parameter in the design of maritime structures such as piers and breakwaters; however, there are reasonable doubts among researchers regarding the quality of its measurement. The objective of the present work was to demonstrate that a stationary calibrated pressure transmitter allows the indirect calculation of the wave height with satisfactory accuracy despite the fact that it is a dynamic event as long as its frequency range is low, as is the case with the gravitational waves of the Costa Rican central Pacific Ocean: between 0.05 and 0.39 Hz. In the absence of a primary standard of periodic pressure disturbances, an alternate path was developed based on the characterization of the parameters of the differential equation characteristic of a pressure measurement system in a shock tube prototype from normal shock wave theory and subsequent verification in a periodic disturbance generator that its attenuation and delay are practically negligible at the frequency of 0.1 Hz. The effect of the different geometry of the chamber of the pressure measurement system used in the sea was evaluated pneumatically by comparison with the dynamic pressure standard in the prototype of the periodic disturbance generator, while the effect of the compressibility of the fluid was evaluated in water in the wave channel of the Laboratory of Maritime Engineering, Rivers and Estuaries of the University of Costa Rica. The results show that the pressure measured from the least-squared adjustment coefficients of an electric current transmitter obtained by stationary calibration is acceptable to estimate the climatology of the gravitational wave characteristic of the Costa Rican central Pacific Ocean with maximum errors of 136 mm in waves of height up to 1.4 m.
DOX-loaded silver nanotriangles and photothermal therapy exert a synergistic antibreast cancer effect via ROS/ERK1/2 signaling pathway
Authors: Li Fan , Yang Huiquan , Cao Yuyu , Li Dongdong , Ma Jing , Liu Peidang
Published: November 2021

The combination of multiple therapies has been proved to be more effective than a single therapy for many cancers. This study aimed to investigate the synergistic antibreast cancer effect of doxorubicin-loaded silver nanotriangles (DOX-AgNTs) combined with near-infrared (NIR) irradiation and explore the underlying mechanism. AgNTs were prepared by a chemical method and DOX was loaded via electrostatic adsorption. Characterization was performed by transmission electron microscopy, ultraviolet–visible spectroscopy and dynamic light scattering. The viability of MDA-MB-231 cells was detected by using MTT assay to evaluate the synergistic anticancer effect of DOX-AgNTs combined with NIR irradiation. The intracellular reactive oxygen species (ROS) level and cell apoptosis were analyzed by flow cytometry. Mitochondrial membrane potential (MMP) was measured with fluorescence microscopy. The mechanism was further investigated with ROS scavenger N-acetylcysteine and specific inhibitors of extracellular signal-regulated kinase 1/2 (ERK1/2), C-jun N-terminal kinase and p38 pathways. Characterization results revealed that the prepared AgNTs were mostly triangular and the mean edge length was about 126 nm. The combination of DOX-AgNTs and NIR exhibited a superior synergistic anticancer effect over single DOX-AgNTs or photothermal therapy (PTT). N-acetylcysteine and ERK1/2 inhibitor U0126 were found to significantly rescue the decreased cell viability, declined MMP and increased apoptosis induced by the combined treatment. Our results suggested that DOX-AgNTs combined with PTT performed a synergistic antibreast cancer effect. The synergy might be closely associated with the excessive production of ROS, changed MMP and the activation of ERK1/2 signaling pathway. These findings might provide a new perspective for the development of breast cancer treatments with excellent efficacy.
Asymptotically exact photonic approximations of chiral symmetric topological tight-binding models
Authors: Palmer S , Ignatov Y , Craster R V , Makwana M
Published: November 2021

Topological photonic edge states, protected by chiral symmetry, are attractive for guiding wave energy as they can allow for more robust guiding and greater control of light than alternatives; however, for photonics, chiral symmetry is often broken by long-range interactions. We look to overcome this difficulty by exploiting the topology of networks, consisting of voids and narrow connecting channels, formed by the spaces between closely spaced perfect conductors. In the limit of low frequencies and narrow channels, these void–channel systems have a direct mapping to analogous discrete mass–spring systems in an asymptotically rigorous manner and therefore only have short-range interactions. We demonstrate that topological tight-binding models that are protected by chiral symmetries, such as the SSH model and square-root semimetals, are reproduced for these void–channel networks with appropriate boundary conditions. We anticipate, moving forward, that this paper provides a basis from which to explore continuum photonic topological systems, in an asymptotically exact manner, through the lens of a simplified tight-binding model.
The dominant eigenvector of a noisy quantum state
Authors: Koczor Bálint
Published: November 2021

Although near-term quantum devices have no comprehensive solution for correcting errors, numerous techniques have been proposed for achieving practical value. Two works have recently introduced the very promising error suppression by derangements (ESD) and virtual distillation (VD) techniques. The approach exponentially suppresses errors and ultimately allows one to measure expectation values in the pure state as the dominant eigenvector of the noisy quantum state. Interestingly this dominant eigenvector is, however, different than the ideal computational state and it is the aim of the present work to comprehensively explore the following fundamental question: how significantly different are these two pure states? The motivation for this work is two-fold. First, comprehensively understanding the effect of this coherent mismatch is of fundamental importance for the successful exploitation of noisy quantum devices. As such, the present work rigorously establishes that in practically relevant scenarios the coherent mismatch is exponentially less severe than the incoherent decay of the fidelity—where the latter can be suppressed exponentially via the ESD/VD technique. Second, the above question is closely related to central problems in mathematics, such as bounding eigenvalues of a sum of two matrices (Weyl inequalities)—solving of which was a major breakthrough. The present work can be viewed as a first step towards extending the Weyl inequalities to eigenvectors of a sum of two matrices—and completely resolves this problem for the special case of the considered density matrices.
Anomaly in the electron orbital g-factor: analysis of data on Ar, Ne and He
Authors: Awobode A M
Published: November 2021

Deviations from the exact value 1, of the electron orbital g-factor

g

L

,

are determined from the measured

g

J

ratios of some states of the noble gas atoms He, Ne and Ar. The calculated values are compared with those previously found from the ratio of the Lande g-factors measured on the atoms of In, Ga and Na. The anomalies obtained from some of the rare gas atoms are, at least, one order of magnitude higher, in absolute value, than those from the one-valence-electron atoms. Configuration interactions and perturbations are considered for the atomic states analyzed and are found to be negligible. Thus, the electron’s orbital g-factor appears significantly anomalous. The implications for QED and the structure of the electron are discussed.
Analysis, circuit implementation and synchronization control of a hyperchaotic system
Authors: Yan Shaohui , Wang Ertong , Wang Qiyu , Sun Xi , Ren Yu
Published: November 2021

A four-dimensional autonomous hyperchaotic system is constructed, and the basic characteristics of the system are studied by the power spectrum, Poincaré maps, 0–1 test and Lyapunov exponents. The system has rich dynamical behaviors, such as bursting oscillations, offset boosting, transient chaos, intermittent chaos and coexistence of attractors. In addition, by studying the coexisting phenomenon and spectral entropy (SE) complexity of different initial values, an initial value that is more suitable for chaotic secure communication is selected. The circuit simulation of the system using Multisim and then the actual hardware implementation of the system by Field Programmable Gate Array (FPGA), these prove the practical existence of the system. Finally, combining the methods of backstepping control, multi-switching synchronization and synchronization of different systems, a set of controllers are proposed which can realize the backstepping multi-switching synchronization of this system with a memristive chaotic system.
Multifunctional performance and ferroelectric phase characteristic of BCTH-Eu ceramics prepared by low-temperature sintering via LiBO2 doping
Authors: Fang Bijun , Zhou Yu , Zhang Shanshan , Zhang Shuai , Ding Jianning
Published: November 2021

Multifunctional performance [(Ba0.85Ca0.15)0.995Eu0.005](Ti0.9Hf0.1)O3 (BCTH-Eu) ceramics were prepared by conventional solid-state low-temperature sintering method via LiBO2 doping, in which the sintering aid LiBO2 was introduced into the calcined perovskite precursor powder through liquid phase coating technique. Phase-pure perovskite structure BCTH-Eu ceramics are obtained by the method, and the sintering temperature is decreased about 150 °C as compared with the conventional method whose sintering temperature is normally above 1450 °C. The ceramics present rather high density, uniform distribution of grains and elementals, and have submicron meter grain size. Due to complex substitution of cations at A-site and B-site of the perovskite structure, the LiBO2-doped BCTH-Eu ceramics exhibit displacive driven normal ferroelectrics accompanied by apparent diffused relaxation characteristic. The 1340 °C sintered LiBO2-doped BCTH-Eu ceramics present maximum piezoelectric constant d33 value of 314 pC/N poled under 20 kV cm−1, and the ceramics sintered between 1320 °C–1330 °C exhibit excellent comprehensive electrical properties and multifunctional performance. Such excellent multifunctional properties obtained in this work can be partially attributed to the coexistence of multi-ferroelectric phases, which is confirmed by dielectric response fitting and Raman Gaussian fitting.
Multiscale time-bin analysis of delayed gamma-ray spectra of fission products
Authors: Elmaghraby Elsayed K , Tohamy M , Comsan M N H
Published: November 2021

The present work provides an analysis scheme of delayed gamma-ray spectra based on multiscale time-bin measurements in order to draw conclusions on the association of observed gamma-lines to certain nuclides, especially following the fission process to serve nuclear safeguards and security. The provided time-bin analysis scheme focuses on estimating post-irradiation decays of fission products with interfering gamma-ray lines having energies within the resolution of the used gamma detector. Being a source of deviation, instead of the fixed values of cooling time before each measurement, pinning down the accurate time for each time-bin that should be assigned to each radionuclide in each measurement had been determined independently. This scheme had enabled multiscale of the time-bin analysis ranging from a minute to hours. Experimental measurements were carried out on a natural uranium dioxide sample irradiated in a mixed field of water moderated neutrons. A stable neutron flux from a 5 Ci Am-Be source was used. Results showed great potential for the use of identification and assessment of the contents. The multiscale time-bin analysis scheme was able to resolve the 74 keV gamma-band to obtain the cross-section for 238U(n,γ)239U reaction, the 884.09 keV gamma-line of 134I/ 134Te, the 306.8 keV gamma-line from 101Tc/101Mo, and the 658 keV gamma-line of 97Nb/97Zr. Time-bin analysis showed that 134I, 101Tc, and 97Nb are not, by themselves, primary fission products, but rather they are the daughters of their high-yield parent fission products (134Te, 101Mo, and 97Zr). In the article, the mathematics of the proposed multiscale time-bin analysis is thoroughly outlined.
Axion-photon conversion in strongly magnetised plasmas
Authors: Millar Alexander J. , Baum Sebastian , Lawson Matthew , Marsh M.C. David
Published: November 2021

Axion dark matter can resonantly convert to photons in the magnetosphere of neutron stars, possibly giving rise to radio signals observable on Earth. This method for the indirect detection of axion dark matter has recently received significant attention in the literature. The calculation of the radio signal is complicated by a number of effects; most importantly, the gravitational infall of the axions onto the neutron star accelerates them to semi-relativistic speed, and the neutron star magnetosphere is highly anisotropic. Both of these factors complicate the calculation of the conversion of axions to photons. In this work, we present the first fully three-dimensional calculation of the axion-photon conversion in highly magnetised anisotropic media. Depending on the axion trajectory, this calculation leads to orders-of-magnitude differences in the conversion compared to the simplified one-dimensional calculation used so far in the literature, altering the directionality of the produced photons. Our results will have important implications for the radio signal one would observe in a telescope.
A test of the standard cosmological model with geometry and growth
Authors: Andrade Uendert , Anbajagane Dhayaa , von Marttens Rodrigo , Huterer Dragan , Alcaniz Jailson
Published: November 2021

We perform a general test of the ΛCDM and wCDM cosmological models by comparing constraints on the geometry of the expansion history to those on the growth of structure. Specifically, we split the total matter energy density, Ω
M
, and (for wCDM) dark energy equation of state, w, into two parameters each: one that captures the geometry, and another that captures the growth. We constrain our split models using current cosmological data, including type Ia supernovae, baryon acoustic oscillations, redshift space distortions, gravitational lensing, and cosmic microwave background (CMB) anisotropies. We focus on two tasks: (i) constraining deviations from the standard model, captured by the parameters ΔΩ
M
 ≡ Ω
M

grow-Ω
M

geom and Δw ≡ w
grow-w
geom, and (ii) investigating whether the S
8 tension between the CMB and weak lensing can be translated into a tension between geometry and growth, i.e. ΔΩ
M
 ≠ 0, Δw ≠ 0. In both the split ΛCDM and wCDM cases, our results from combining all data are consistent with ΔΩ
M
= 0 and Δ w = 0.
If we omit BAO/RSD data and constrain the split wCDM cosmology, we find the data prefers Δw < 0 at 3.6σ significance and ΔΩ
M
 > 0 at 4.2σ evidence.
We also find that for both CMB and weak lensing, ΔΩ
M
and S
8 are correlated, with CMB showing a slightly stronger correlation. The general broadening of the contours in our extended model does alleviate the S
8 tension, but the allowed nonzero values of ΔΩ
M
do not encompass the S
8 values that would point toward a mismatch between geometry and growth as the origin of the tension.
Acausality in superfluid dark matter and MOND-like theories
Authors: Hertzberg Mark P. , Litterer Jacob A. , Shah Neil
Published: November 2021

There has been much interest in novel models of dark matter that exhibit interesting behavior on galactic scales. A primary motivation is the observed Baryonic Tully-Fisher Relation in which the mass of galaxies increases as the quartic power of rotation speed. This scaling is not obviously accounted for by standard cold dark matter. This has prompted the development of dark matter models that exhibit some form of so-called MONDian phenomenology to account for this galactic scaling, while also recovering the success of cold dark matter on large scales. A beautiful example of this are the so-called superfluid dark matter models, in which a complex bosonic field undergoes spontaneous symmetry breaking on galactic scales, entering a superfluid phase with a 3/2 kinetic scaling in the low energy effective theory, that mediates a long-ranged MONDian force. In this work we examine the causality and locality properties of these and other related models. We show that the Lorentz invariant completions of the superfluid models exhibit high energy perturbations that violate global hyperbolicity of the equations of motion in the MOND regime and can be superluminal in other parts of phase space. We also examine a range of alternate models, finding that they also exhibit forms of non-locality.
Low scale leptogenesis and dark matter in the presence of primordial black holes
Authors: Das Suruj Jyoti , Mahanta Devabrat , Borah Debasish
Published: November 2021

We study the possibility of low scale leptogenesis along with dark matter (DM) in the presence of primordial black holes (PBH). For a common setup to study both leptogenesis and DM we consider the minimal scotogenic model which also explains light neutrino mass at radiative level. While PBH in the mass range of 0.1–105 g can, in principle, affect leptogenesis, the required initial PBH fraction usually leads to overproduction of scalar doublet DM whose thermal freeze-out occurs before PBH evaporation. PBH can lead to non-thermal source of leptogenesis as well as dilution of thermally generated lepton asymmetry via entropy injection, with the latter being dominant. The parameter space of scotogenic model which leads to overproduction of baryon or lepton asymmetry in standard cosmology can be made consistent in the presence of PBH with appropriate initial mass and energy fraction. On the other hand, for such PBH parameters, the scalar DM is constrained to be in light mass regime where its freeze-out occurs after PBH evaporation. We then discuss the possibility of fermion singlet DM with N
2 leptogenesis in the same model where due to singlet nature of DM, its connection with PBH parameters and hence leptogenesis becomes stronger compared to the previous case.
Investigation of aerodynamics and heat transfer of the modular jet recuperator
Authors: Alekseev P D , Leukhin Yu L
Published: November 2021

A study of the aerodynamics and heat transfer of a jet modular recuperator with a change in its geometric characteristics has been carried out. The influence of the in-line and staggered arrangement of the blowing holes, as well as the diameter of the perforated pipe is considered. In all considered variants, the number of holes, their diameter and gas flow rate through the recuperator remained unchanged. Numerical modeling of the problem was carried out in a three-dimensional setting using the ANSYS Fluent 15.0 software package. It was found that with the in-line arrangement of the blowing holes, secondary flows are formed between their longitudinal rows in the form of swirling jets of opposite rotation directed towards the outlet section of the recuperative device, through which the main part of the heated air flows out. With the staggered arrangement of the blowing holes, the formation of spiral vortices is disturbed, the air flow is carried out along the entire cross section of the annular channel, increasing the drift effect of the flow on the impact jets, which leads to a decrease in the intensity of heat transfer and its uniformity along the length of the working surface. An increase in the diameter of the inner perforated pipe leads to a decrease in the drift effect of the cocurrent flow on the jets, an increase in the distribution uniformity of the heat flux along the length of the heat transfer surface, and an increase in the heat transfer coefficient.
Numerical simulation of a separated flow in a ribbed channel by the RANS and LES methods
Authors: Barsukov A V , Terekhov V V , Terekhov V I
Published: November 2021

The results of numerical simulation of a turbulent flow in a flat channel in the presence of vortex generators in the form of periodic solid ribs by the RANS and LES method are presented. The Reynolds number calculated by the rib height and the average flow rate is Re = 12600. The influence of the distance between the ribs on the flow structure is investigated. The boundaries of different types of roughness and their influence on the heat transfer intensity are shown.
Heat transfer and skin-friction in a nonequilibrium adverse pressure gradient
Authors: Kiselev N A , Vinogradov Yu A , Zditovets A G
Published: November 2021

The paper presents the results of an experimental study of influence of a weak and moderate nonequilibrium adverse pressure gradient (APG) on the parameters of the dynamic and thermal boundary layers. The Reynolds number based on the momentum thickness at the beginning of the APG region was Re **=5500. The section of the channel with APG was a slotted channel with an opening angle of the upper wall of 0-14°. The values of the relative (referred to the parameters in a zero pressure gradient flow at the same Re **) friction and heat transfer coefficients, as well as the Reynolds analogy factor depending on the longitudinal pressure gradient, are obtained. The values of the relative friction coefficient decreased to cf/cf0
=0.7 and those of the heat transfer to St/St0=0.9. A maximum value of the Reynolds analogy factor (St/St0)/(cf/cf0
)=1.16 was reached for the pressure gradient parameter β=2.9. The ratio of the heat transfer and drag coefficients of the dimpled to smooth surfaces remained approximately constant regardless of the presence or magnitude of a adverse pressure gradient.
Heat transfer enhancement in superheated hydrocarbon fluids due to traces of water
Authors: Lukianov K V , Kotov A N , Starostin A A
Published: November 2021

For the specific mode of pulse heating of a wire probe immersed in a test liquid (saturated hydrocarbon), the effect of enhancement of the heat transfer through the probe surface has been revealed. The characteristic heating time is from 10 to 20 ms. The objects of research are n-hexane, n-decane, and n-hexadecane. It is shown that the addition of 0.003% water increases the heat transfer to 10% in the course of approaching the boiling-up temperature of liquid. Simulation of the experimental conditions shows the possibility of microconvection in the most heated boundary layer of a liquid about 10 μm thick.
Study of the Leidenfrost Effect on Heterogeneous Surfaces of Complex Structure
Authors: Makarov P G , Artamonov A V , Dmitriev A S
Published: November 2021

This work is devoted to a research of water droplets that are put in-between two parallel metal strings the distance between which is comparable to linear size of the droplet. Strings are heated by Joule heating to temperatures that exceed critical temperatures of nucleate and film boiling. Different configurations of strings’ side surface have been tested: smooth and with winding made of the same material (intermittent and uninterrupted). Experiments have shown that droplets on these types of surface do not boil away quickly or fall down. Instead they displayed behavior that can be described as floating, either stable or with directed motion, depending on surface structure or relief. Multiple experiments have shown that it is quite similar to Leidenfrost effect demonstrated on a flat overheated surface by liquids.
Effect of dustiness in atmospheric air on the formation and characteristics of condensation aerosol
Authors: Mayorov V O , Yastrebov A K , Yu Levashov V
Published: November 2021

In this work, the simulation of the formation process of condensation aerosol in atmospheric air is carried out. The influence of the initial supersaturation ratio and dustiness content on the formation mechanism and macroscopic characteristics of the aerosol is investigated.
Development of an automated system for experimental investigation of thermal processes in a hydrogen-oxygen steam generator
Authors: Molotov I M , Schastlivtsev A I , Yamshchikova L V , Molotova I A
Published: November 2021

The paper presents the results of the development and creation of an automated system of scientific research (ASSR). It provides experimental studies of heat and mass transfer processes in a hydrogen-oxygen steam generator (HOSG). The most relevant fields of application of hydrogen-oxygen steam generators are considered. The paper discusses the most relevant areas of application of hydrogen-oxygen steam generators, scientific and technical barriers to the introduction of technology and the features of the construction of ASSR for experimental research. The schematic diagram of the primary measuring transducers and the control mechanisms of the experimental stand are described. The choice of the configuration of the automated control and measurement system is justified from the point of view of completeness and reliability of the obtained data.
Effect of high-temperature oxidation on the surface properties as applied to quenching of high-temperature bodies
Authors: Molotova I A , Zabirov A R , Yagov V V , Terentyev E V , Antonov N N , Molotov I M , Tumarkin A V , Kharkov M M
Published: November 2021

This paper contains the results of studying the surface properties before and after high-temperature oxidation. For this, the plate zirconium samples with chromium, gold and silver coatings were prepared. Cut profiles of the samples were obtained to study the structure of coatings and the thickness of the oxide layer. The measurements of contact angles were carried out. The results showed that a porous heterogeneous oxide layer was formed on the samples after high-temperature oxidation. At the same time, the wettability of the samples was improved. The thickness of the oxide layer on the chrome-coated zirconium sample was the smallest. Using of electroplated silver coating for experiments involving heating to high temperatures seems inappropriate because it was damaged after the oxidation tests. It is assumed that the main factor which influence on the rise of the transition temperature to the intensive cooling regime during quenching is the appearance of the oxide layer, rather than the improved wettability and wickability. High-temperature oxidation leads to the simultaneous formation of an oxide layer with a low thermal effusivity and to an improvement in wettability, therefore the contribution of each of these two effects on quenching can be confused or overestimated.
Experimental study of the adiabatic wall temperature of a cylinder in a supersonic cross flow
Authors: Popovich S S , Kiselev N A , Zditovets A G , Vinogradov Y A
Published: November 2021

The results of an experimental study of the adiabatic wall temperature for a supersonic air flow across the cylinder are presented. The temperature was measured contactlessly using an InfraTEC ImageIR 8855 thermal imager through a ZnSe infrared illuminator. The freestream Mach number was 3.0, input flow total temperature was 295 K, and the total pressure 615 kPa. The Reynolds number calculated from the cylinder diameter (30 mm) was about 106. It is shown that it is possible in principle to determine the high-speed flow total temperature by defining the maximum temperature of a cylindrical probe at the front critical point. Thermograms of the wall temperature distribution along the profile of the cylinder were obtained. The research was performed at the experimental facilities of the Institute of Mechanics of Lomonosov Moscow State University.
Enhancement of heat transfer for boiling in nanofluid
Authors: Sapozhnikov S Z , Yu Mityakov V , Pavlov A V , Bobylev P G , Andreev Yu V , Proskurin V M , Vinogradov M D
Published: November 2021

The paper considers heat transfer during boiling of subcooled water with suspended nanoparticles Al2O3 using a suspension from 0.32% to 4%. On a spherical model, the local heat flux per unit area was measured by the method of gradient heatmetry for model temperature of 464 °C and water temperature of 64 °C. The results are compared with the data obtained at the same temperature conditions for pure water. Enchancement of heat transfer was revealed in the entire concentration range - with a maximum at a particle concentration close to 1%.
Heat transfer enhancement during condensation of water steam on inclined pipe
Authors: Sapozhnikov S Z , Yu Mityakov V , Mityakov A V , Yu Babich A , Zainullina E R
Published: November 2021

This paper presents experimental study of heat transfer during film condensation of saturated water steam on the outer surface of the inclined pipe by gradient heatmetry. Heat flux per unit area was measured by gradient heat flux sensors made of a single-crystal bismuth. The experimental results are presented in the graphs of heat flux per unit area dependence on time and azimuthal angle. The highest average heat transfer coefficient during condensation of α = 6.94 kW/(m2 • K) was observed when the pipe was inclined at the angle of ψ = 20 °. This value exceeds one obtained on a vertical pipe by 14.9 %. Heat transfer enhancement during condensation of saturated water steam on inclined pipe is associated with changes in condensate film flow. Another part of experiments was made by simultaneously using of gradient heatmetry and condensate flow visualization. Experimental results confirmed the applicability and high informative content of proposed comprehensive method. Comprehensive study of heat transfer during condensation confirmed that heat flux per unit area pulsations may be explained by the formation of individual drops, their coalescence, and drainage from the sensor surface.
A map of regimes of evaporation and boiling in the horizontal liquid layer on the modified surface
Authors: Shvetsov D A , Pavlenko A N , Brester A E , Zhukov V I
Published: November 2021

The paper presents the results of the study of the evaporation and boiling regimes in thin horizontal layers of liquid on a modified surface in a wide range of changes in the pressure and height of the liquid layer. Depending on the heat flux, pressure, and height of the liquid layer, the formation of various structures was observed. In this paper, maps of the evaporation and boiling regimes are obtained, which show the heat fluxes from the natural convection regime up to the boiling crisis, depending on the height of the liquid layer. The results are compared with the calculation dependencies.
International Conference “Advanced Element Base of Micro- and Nano-Electronics with Using of To-Date Achievements of Theoretical Physics” 20-23 April 2021, Moscow, Russia
Authors: Belyaev V V , Chausov D N , Kuznetsov M M
Published: November 2021

A brief description of scientific program and papers of International Conference “Advanced Element Base of Micro- and Nano-Electronics with Using of To-Date Achievements of Theoretical Physics” is presented. It is an annual conference of Moscow Region State University (MRSU).

List of Organizing Committee, Program Committee are available in this pdf.
A software package for modeling the propagation of dynamic wave disturbances in heterogeneous multi-scale media
Authors: Khokhlov N.
Published: November 2021

The paper considers a software package designed to simulate the propagation of dynamic wave disturbances in heterogeneous media. One of the main features of the considered software package is numerical algorithms with an explicit selection of inhomogeneities. Within the framework of the work, such inhomogeneities as pores, fractures and interfaces between media (contact boundaries) are considered. The considered algorithms make it possible to perform calculations in different scale settings in micro and macro sizes. The mathematical model is based on the equations of the linear theory of elasticity. For the calculation, block structural meshes are used. The software package is parallelized using MPI and OpenMP technologies. Separate parts of the algorithm are parallelized using graphics accelerators such as GPGPU. The paper describes the features of the algorithms under consideration and provides examples of calculations that demonstrate the capabilities of the algorithm.
Diagnostics of atomic- molecular interactions in nano-compositions organics-inorganics by means of infrared spectroscopy
Authors: Azhgalieva A S , Klassen N V , Likhter A M , Pokidov A P , Fursova T N , Tsebruk I S
Published: November 2021

This paper prolongs our studies of the formation and properties of the organic-inorganic scintillating compositions from activated polystyrene and inorganic nanoparticles from cesium iodid and sulfate. The compositions from the solution of polystyrene in benzene and nano- or micro-particles of cesium iodide were solidified in the form of thin films. Then some of the films were subjected to rolling. The variations of the infrared transmission spectra of the compositions were measured either during their solidification or after the solidification and rolling. The new absorption band was revealed in the process of the solidification and disappeared after it. The fractal-like structures of parallel rows were formed in the films. Quasi-periodical oscillations of the transmission spectra were found in several infrared regions ascribed to the interaction of the infrared radiation with the fractal super-structure of the films. The modifications of the absorption spectra found in our experiments are attributed to the interactions of polystyrene molecules with benzene molecules and nanoparticles of cesium iodide.
Synthesis of rare-earth nanosized phosphors using microwave processing
Authors: Vlasenko A B , Bakhmetyev V V
Published: November 2021

Nanomaterials find permanently extending applications in various areas of life. In particular, nanosized phosphors can be used as pharmaceutical carriers capable of emitting ultraviolet or visible light that activates a photosensitizer, thus significantly expanding the possibilities of photodynamic therapy in the treatment of oncological, bacterial and viral diseases. The conditions required for the use of nanosized phosphors in medicine include their fine dispersion and effective luminescence in the red region of visible light spectrum upon stimulation by X-ray radiation of the range accepted for medical applications, particularly for diagnostic and therapeutic purposes in many diseases. The aim of this work was to study the effect of microwave treatment of Y2O3:Eu phosphors prepared by hydrothermal synthesis in ethylene glycol at 230 °C for 6 hours, involving the decomposition of mixed acetate. In order to reduce the aggregation and growth of the resulting particles, Aerosil A300 with average particle size 7 nm was added to the reaction mixture in the course of hydrothermal synthesis in the ratio 1:1 relating to the obtained phosphor. The microwave treatment was carried out at 800 °C for 5 minutes. The developed method provided Y2O3:Eu phosphor samples featuring with increased luminescence intensity in the region 610…700 nm compared to similar phosphors earlier prepared using the rapid thermal annealing (RTA) procedure.
Anomalous transport of electrons in an electric discharge with transverse magnetic field
Authors: Kirdyashev K P
Published: November 2021

The experimental data showing the relationship of excitation of microwave oscillations with abnormally transport of electrons across the magnetic field in turbulent plasma are presented. The mechanism of the formation of the discharge current due to scattering of drift electrons in the near-electrode layers of the electric discharges on microwave oscillations has been substantiated. The conditions for the manifestation of the turbulent mechanism of anomalous electron transport through the magnetic barrier at the boundary of the toroidal electric discharge have been studied most fully. The mobility of electrons across a magnetic field is one of the main parameters of electric discharges that use crossed electric and magnetic fields for technological purposes.