bluuebunny/crossref_metadata_2025 huggingface dataset:
Acoustic streaming in water induced by an asymmetric dielectric-barrier-discharge plasma actuator at the initiation stage
Authors: Zhang Xin , Cui Yong-dong , Qu Feng , Li Hua-xing
Published: January 2022

When acoustic waves with broadband frequency and high amplitude pass through a medium, it absorbs their momentum to induce a quasi-steady flow, which is commonly referred to as acoustic streaming (AS). The acoustic energy in AS is clean energy, and actuators that release acoustic energy by AS can control flow without contacting the controlled object and have considerable potential in microfluidic systems for enhancing transport and mixing. Recently, AS was observed to be induced in quiescent air by a dielectric-barrier-discharge plasma actuator. However, a normal AS flow and a tangential wall jet can be created by the plasma actuator in quiescent air. The AS flow suffers unavoidably from the induced wall jet. For example, the location of the production of the AS flow moves downstream of the upper electrode under the influence of the induced wall jet. In addition, whether the plasma actuator can generate AS in a liquid is the key to applying AS in biomedicine and remains unknown. Here, an asymmetric dielectric-barrier-discharge plasma actuator during the first sinusoidal high-voltage cycle when the induced flow field and the effect of the heating are not significant is suspended over the surface of distilled water but not in contact with the water. Importantly, AS in distilled water produced by a plasma actuator and causing depressions in the liquid surface is first observed by using the highly accurate phase-locked image-freezing schlieren technique. Based on the results, the formation process for AS in distilled water is proposed.
Image features of a splashing drop on a solid surface extracted using a feedforward neural network
Authors: Yee Jingzu , Yamanaka Akinori , Tagawa Yoshiyuki
Published: January 2022

This article reports nonintuitive characteristic of a splashing drop on a solid surface discovered through extracting image features using a feedforward neural network (FNN). Ethanol of area-equivalent radius about 1.29 mm was dropped from impact heights ranging from 4 cm to 60 cm (splashing threshold 20 cm) and impacted on a hydrophilic surface. The images captured when half of the drop impacted the surface were labeled according to their outcome, splashing or nonsplashing, and were used to train an FNN. A classification accuracy ≥96% was achieved. To extract the image features identified by the FNN for classification, the weight matrix of the trained FNN for identifying splashing drops was visualized. Remarkably, the visualization showed that the trained FNN identified the contour height of the main body of the impacting drop as an important characteristic differentiating between splashing and nonsplashing drops, which has not been reported in previous studies. This feature was found throughout the impact, even when one and three-quarters of the drop impacted the surface. To confirm the importance of this image feature, the FNN was retrained to classify using only the main body without checking for the presence of ejected secondary droplets. The accuracy was still ≥82%, confirming that the contour height is an important feature distinguishing splashing from nonsplashing drops. Several aspects of drop impact are analyzed and discussed with the aim of identifying the possible mechanism underlying the difference in contour height between splashing and nonsplashing drops.
Transient performance analysis of a novel design of portable magnetic refrigeration system
Authors: Kashyap Uddip , Kumar Ashish , Sardespande Vishal , Saha Sandip K.
Published: January 2022

The widely used ice chamber-based cold storage for the transportation and storage of vaccines has several disadvantages, including uncontrolled overall temperature, water accumulation, and frequent ice pack renewal. Therefore, in this work, we numerically studied a novel vaccine storage system by coupling magnetic refrigeration and ice packs developed by conserving the advantages of an ice-based system. A two-dimensional numerical model is developed to analyze the magnetohydrodynamic natural convection in the storage chamber. Gadolinium of 0.08 kg is used to produce a cooling power of 31.514 W and a coefficient of performance of 1.3. With the constant heat leaked of 0.828 W into the system with dimensions of (0.1 × 0.1) m, the average life of the ice pack of 0.75 kg is 1.03 h. By introducing the magnetocaloric effect, the life of the same ice pack can be infinite with no load. The dynamic mode decomposition analysis reveals that the most dominant fluid interaction occurs between the cooled gadolinium plate and the adjacent fluid, resulting in efficient cooling of the air chamber. The developed vaccine chamber design will significantly improve the existing ice pack system with a nominal increase in cost and system weight.
Design and modeling of a single-balanced high-Tc superconducting Josephson-junction terahertz mixer
Authors: Gao Xiang , Li Huanxin , Du Jia , Zhang Ting , Song Jinpeng , Bu Xiangyuan , An Jianping , Liu Heng
Published: January 2022

High-Tc superconducting (HTS) receivers are promising candidates for terahertz (THz) communication applications due to their superior sensitivity and the cooling attainability with a miniature cryogenic system. Nevertheless, currently reported HTS mixers are mostly single-junction devices, and a more complicated architecture like the balanced configuration has not been investigated. This paper presents the design of a 600-GHz single-balanced HTS mixer, where detailed electromagnetic simulations are carried out to optimize the coupling efficiency and port isolation, as well as desired amplitude and phase relationship. To predict the noise and conversion performance, we present an innovative multiport network interleaving-based modeling method that enables powerful simulation verifications for single-balanced HTS Josephson mixers. Simulation results show that the presented device exhibits very good HTS mixer performance at the 600-GHz band, which validates the effectiveness of the design and the potential of the mixer for THz communication applications.
The transition to turbulence in rarefaction-driven Rayleigh–Taylor mixing: Effects of diffuse interface
Authors: Wang Rui , Song Yang , Ma Zongqiang , Ma Dongjun , Wang Lili , Wang Pei
Published: January 2022

Effects of interface diffusion on the transition to turbulence in rarefaction-driven flows are numerically investigated via Implicit Large-Eddy simulation. Three-dimensional, multimode perturbations are imposed on the diffuse interface between Air and SF6, with various diffusion layer thicknesses. A non-constant acceleration ranging from 103g0 to 104g0, where g0 is the acceleration due to gravity, is generated by the interaction between the interface and a rarefaction wave. Evolution of first- and second-order statistics, instantaneous flow structures, and the power spectrum of turbulent kinetic energy as well as spatial distributions of energy budget are evaluated, in order to confirm the accuracy and robustness of the mixed mass transition criterion proposed here. Meanwhile, it turns out that transitional behaviors are mainly governed by Reynolds normal stresses in the plane perpendicular to the streamwise direction. Furthermore, as interface diffuses, the decrease in peak values of pressure and advection components dominated in the laminar regimes, particularly at the bubble tips, eventually leads to transition delay.
Measuring infectious SARS-CoV-2 in clinical samples reveals a higher viral titer:RNA ratio for Delta and Epsilon vs. Alpha variants
Authors: Despres Hannah W. , Mills Margaret G. , Shirley David J. , Schmidt Madaline M. , Huang Meei-Li , Roychoudhury Pavitra , Jerome Keith R. , Greninger Alexander L. , Bruce Emily A.
Published: January 2022

Novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants pose a challenge to controlling the COVID-19 pandemic. Previous studies indicate that clinical samples collected from individuals infected with the Delta variant may contain higher levels of RNA than previous variants, but the relationship between levels of viral RNA and infectious virus for individual variants is unknown. We measured infectious viral titer (using a microfocus-forming assay) and total and subgenomic viral RNA levels (using RT-PCR) in a set of 162 clinical samples containing SARS-CoV-2 Alpha, Delta, and Epsilon variants that were collected in identical swab kits from outpatient test sites and processed soon after collection. We observed a high degree of variation in the relationship between viral titers and RNA levels. Despite this, the overall infectivity differed among the three variants. Both Delta and Epsilon had significantly higher infectivity than Alpha, as measured by the number of infectious units per quantity of viral E gene RNA (5.9- and 3.0-fold increase;
P
< 0.0001,
P
= 0.014, respectively) or subgenomic E RNA (14.3- and 6.9-fold increase;
P
< 0.0001,
P
= 0.004, respectively). In addition to higher viral RNA levels reported for the Delta variant, the infectivity (amount of replication competent virus per viral genome copy) may be increased compared to Alpha. Measuring the relationship between live virus and viral RNA is an important step in assessing the infectivity of novel SARS-CoV-2 variants. An increase in the infectivity for Delta may further explain increased spread, suggesting a need for increased measures to prevent viral transmission.
A compensatory link between cleavage/polyadenylation and mRNA turnover regulates steady-state mRNA levels in yeast
Authors: Moqtaderi Zarmik , Geisberg Joseph V. , Struhl Kevin
Published: January 2022

Significance

Cells coordinate the rates of major biological processes in response to environmental conditions such as nutrient availability and temperature. Coordination mechanisms in which effects on one process are compensated for by effects on another process maintain an appropriate cellular balance. Here, we uncover a compensatory link between cleavage/polyadenylation, which generates poly(A) tails at mRNA 3′ ends, and mRNA decay. This compensatory link suggests that during cleavage/polyadenylation in the nucleus, mRNA isoforms are marked in a manner that persists upon translocation to the cytoplasm. This mark affects the activity of mRNA degradation machinery, thus influencing mRNA stability and allowing cells to maintain relatively similar levels of mRNA isoforms even when cleavage/polyadenylation rates change in response to environmental conditions.
Modeling damage to the solid electrolyte matrix in composite electrodes: role of ionic conductivity
Authors: Shang Shuaipeng , Chen Zhipeng , Wang Fenghui
Published: January 2022

Solid composite electrodes play a critical role in all-solid-sate-batteries, but intercalation-induced expansion of the active materials will cause damage in the matrix and affect the performance of battery. In this work, damage evolution in the solid electrolyte (SE) matrix related to migration of ions/electrons in SE matrix, transport of species in electrode particles, local current densities at the SE/active materials interface, and mechanical deformation of the structure is investigated based on the non-local damage approach. The influence of mechanical damage on the electrochemical performance is modeled by coupling the damage variable and ionic conductivity of the SE. The results indicate that for low ionic conductivity, the damage of the SE matrix is inhomogeneous across the composite electrodes, while for high ionic conductivity, the damage of the SE matrix is uniform. We also investigate the effect of damage on the electrochemical performance of battery and it is shown that capacity loss is significant for low ionic conductivity, but shows little variation under high ionic conductivity.
Exploring the biotoxicity of carbon boride nanosheets (BC3) based on the villin headpiece protein model
Authors: Jia Xiao , Liu Yang , Yang Yanmei , Zhang Chao , Qu Yuanyuan , Li Yong-Qiang , Liu Xiangdong , Li Weifeng
Published: January 2022

The recently synthesized single-layer carbon boride (BC3), has been explored for biomedical applications. However, the interaction between BC3 and biomolecules needs to be further explored to evaluate its potential toxicity to biological systems. Here, using the villin headpiece (HP35) as a representative protein model, the binding behavior of proteins to BC3 and the structure evolution of proteins were studied by molecular dynamics simulation. Our data revealed that HP35 can quickly load and form stable binding to BC3 surface. The BC3 caused moderate destruction of the HP35 by destroying its native hydrogen bonds and unwinding its helices. The BC3/HP35 interaction strength is linearly correlated with the contact number between BC3 and HP35. HP35 forms binds to BC3 mainly through van der Waals interactions and π-π stacking. Compared to graphene, the polarized nature of BC3 can slightly strengthen the binding between BC3 and HP35. BC3 still faces the problem of potential cytotoxicity to biological system. These findings shed light on the biological effects of BC3 at the molecular level and guide the future application of BC3-based devices in biomedicine.
Surface structure of magnetite (111) under oxidizing and reducing conditions
Authors: Creutzburg Marcus , Sellschopp Kai , Gleißner Robert , Arndt Björn , Vonbun-Feldbauer Gregor B , Vonk Vedran , Noei Heshmat , Stierle Andreas
Published: January 2022

We report on differences in the magnetite (111) surface structure when prepared under oxidizing and reducing conditions. Both preparations were done under UHV conditions at elevated temperatures, but in one case the sample was cooled down while keeping it in an oxygen atmosphere. Scanning tunneling microscopy after each of the preparations showed a different apparent morphology, which is discussed to be an electronic effect and which is reflected in the necessity of using opposite bias tunneling voltages in order to obtain good images. Surface x-ray diffraction revealed that both preparations lead to Fe vacancies, leading to local O-terminations, the relative fraction of which depending on the preparation. The preparation under reducing conditions lead to a larger fraction of Fe-termination. The geometric structure of the two different terminations was found to be identical for both treatments, even though the surface and near-surface regions exhibit small compositional differences; after the oxidizing treatment they are iron deficient. Further evidence for the dependence of iron vs oxygen fractional surface terminations on preparation conditions comes from Fourier transform infrared reflection-absorption spectroscopy, which is used to study the adsorption of formic acid. These molecules dissociate and adsorb in chelating and bidentate bridging geometries on the Fe-terminated areas and the signal of typical infrared absorption bands is stronger after the preparation under reducing conditions, which results in a higher fraction of Fe-termination. The adsorption of formic acid induced an atomic roughening of the magnetite (111) surface which we conclude from the quantitative analysis of the crystal truncation rod data. The roughening process is initiated by atomic hydrogen, which results from the dissociation of formic acid after its adsorption on the surface. Atomic hydrogen adsorbs at surface oxygen and after recombination with another H this surface hydroxyl can form H2O, which may desorb from the surface, while iron ions diffuse into interstitial sites in the bulk.
Single-wall carbon nanotube mechanical behavior using the modified embedded atom method with bond order (MEAM-BO)
Authors: Ababtin Sultana , Adibi Sara , Mun Sungkwang , Carino Ricolindo L , Dickel Doyl E , Gwaltney Steven R , Novotny M A , Baskes M I , Horstemeyer M F
Published: January 2022

We report the capability of the modified embedded atom method with bond order (MEAM-BO) potential to capture single-wall carbon nanotube (SWCNT) mechanical properties accurately by calculating the wavenumber of the radial breathing mode (RBM), elastic properties, and folding energy (ΔE), which are all associated with bond curvature. We find that the existing MEAM-BO potential gives results that correlate well with experimental and density functional theory (DFT) results with the exception of the folding energy. The MEAM-BO potential parameters are updated to produce a MEAM-BO* potential for the SWCNT system. Interestingly, including the SWCNT data base, improved the previous fit of the C-H binary system. Previous studies in the literature concluded that the CNTs diameter, d, was inversely proportional to the RBM wavenumber and folding energy. When comparing MEAM-BO*, MEAM-BO, REBO, and ReaxFF with DFT results, we found that MEAM-BO* gave the closest results to DFT for the RBM wavenumbers, folding energy, and SWCNT Young’s modulus, especially for small diameter SWCNTs. We conclude that MEAM-BO* captures SWCNT curvature effects and unsaturated hydrocarbons bond behavior.
Dislocation structure analysis in the strain gradient of torsion loading: a comparison between modelling and experiment
Authors: Stricker Markus , Ziemann Michael , Walter Mario , Weygand Sabine M , Gruber Patric , Weygand Daniel
Published: January 2022

Complex stress states due to torsion lead to dislocation structures characteristic for the chosen torsion axis. The formation mechanism of these structures and the link to the overall plastic deformation are unclear. Experiments allow the analysis of cross sections only ex situ or are limited in spacial resolution which prohibits the identification of the substructures which form within the volume. Discrete dislocation dynamics simulations give full access to the dislocation structure and their evolution in time. By combining both approaches and comparing similar measures the dislocation structure formation in torsion loading of micro wires is explained. For the ⟨100⟩ torsion axis, slip traces spanning the entire sample in both simulation and experiment are observed. They are caused by collective motion of dislocations on adjacent slip planes. Thus these slip traces are not atomically sharp. Torsion loading around a ⟨111⟩ axis favors plasticity on the primary slip planes perpendicular to the torsion axis and dislocation storage through cross-slip and subsequent collinear junction formation. Resulting hexagonal dislocation networks patches are small angle grain boundaries. Both, experiments and discrete dislocation simulations show that dislocations cross the neutral fiber. This feature is discussed in light of the limits of continuum descriptions of plasticity.
A simple modular kit for various wave optic experiments using 3D printed cubes for education
Authors: Haverkamp Nils , Pusch Alexander , Heusler Stefan , Gregor Markus
Published: January 2022

Quantum technology is an emerging field of physics and engineering and important applications are expected in quantum computing, quantum sensing, quantum cryptography, quantum simulation, and quantum metrology. Thus the need for education in this field is increasing, while still remaining challenging. While the need for basic education in quantum physics is accepted in many countries, the possibilities still are limited. Concerning fundamental topics such as the superposition principle and complementarity, on the one hand, a large variety of simulations and animations are available. However, single-photon experiments are still beyond reach for any school, due to costs and technical difficulties. A promising approach seems to be a combination of cheap, easy-to-use and modular experimental kits for school which allow for wave optical experiments, in combination with quantum optical simulations. In the present article, we focus on the modularity and accessibility of an experimental kit based on 3D-printed ‘Optic Cubes’, which allow for a large variety of experiments in high school.
Demonstration experiment in the study of Fresnel diffraction
Authors: Grebenev I V , Kazarin P V
Published: January 2022

The article describes a methodology for studying Fresnel diffraction with the active involvement of students in discussing the results of a demonstration experiment. To create a clearly visible model of Fresnel zones, a centimeter radio wave range was chosen, in which the first zone is about 10 cm in size. This makes visible the created combinations of open and closed sections of the wavefront and allows students to predict the results of demonstrations. To maintain the cognitive activity of students, the method of creating and resolving educational contradictions, problem situations is used.
Comparison of forces for the Crookes and Hettner radiometers
Authors: Williams Hollis
Published: January 2022

The Crookes radiometer (also known as a light mill) is a fascinating sunlight-powered device, in which a set of vanes is placed inside a glass bulb within which a partial vacuum has been pulled. The vanes then rotate when sunlight shines on the bulb. The reason for the turning of the vanes was subject to intense debate and many students still have an incorrect understanding of the device. We analyse the forces involved in a much less well-known radiometer (called the Hettner radiometer) and show that this can help us to understand the forces involved in the Crookes radiometer in a more unified way.
Comprehensive observations on pendulum oscillation using stereo vision
Authors: Ristanto Sigit , Nugroho Waskito , Sulistya Eko , Suparta Gede B
Published: January 2022

We have developed a stereo vision system for observing real objects for experimental physics demonstration. The stereo vision observes objects from two different points of view. An observer can identify the distance and velocity of an object based on at least two different points of view. This paper demonstrates our comprehensive observation in a pendulum oscillation experiment to test the stereo vision system where a stereo camera is in a forward view position. The stereo camera produces stereo images. We use automatic object tracking techniques to obtain the 3D position of the pendulum in real space based on the sequential stereo images of the pendulum movement. The experimental results in a 3D graph that shows the trajectory of the pendulum oscillation. We confirm the common understanding of the oscillation movement by obtaining the graph of the pendulum oscillation as a function of time. We can obtain the oscillation motion parameters such as amplitude, angular frequency, frequency, period, and initial phase. Also, we can show the damping oscillation phenomena and the damping factor.
System for characterizing the electromechanical properties of REBCO coated conductors through simultaneous measurements of critical current and mechanical load
Authors: Diaz Mark Angelo , De Leon Michael , Shin Hyung-Seop , Mean Byeong-Jin , Lee Jae-Hun
Published: January 2022

Various test techniques have been established to investigate the electromechanical properties (EMPs) of coated conductor (CC) tapes under external loads. The most conventional method is to examine variations in a critical current, I
c, by repeatedly measuring the V–I curves while intermittently applying a load or deformation to the CC tape. Conventional methods for obtaining EMPs, such as the reversible limits for I
c degradation, require repeated measures of I
c in a loading–unloading scheme, and this entails considerable time and effort, therefore, they must be improved for practical and engineering reasons. We recently developed an easy-to-use system that can continuously measure variations in I
c while applying a load or deformation to the CC tape, thereby evaluating its EMPs. The main advantages of the new measurement system are real-time monitoring of I
c behaviors during loading and allowing reduced the test time. While it uses a conventional test configuration, this new system continuously measures I
c through effective feedback control of the electrical-field voltage induced in the CC tape specimen during loading. Through this feedback control system, the I
c degradation behaviors in CC tapes resulting from possible cracking in the superconducting layer during loading are depicted. The reversible limits for I
c degradation were also determined. To assess the effectiveness of this newly developed measuring system, the applicability of the method was identified by evaluating the EMPs of various commercially available CC tapes. By comparing the results with those achieved using conventional testing, we found this to effectively evaluate the EMPs of CC tapes. The results showed that this system provides a simple way of evaluating the EMPs of high-temperature superconductor CC tapes by simultaneously measuring variations in I
c under load or deformation. It is much faster at depicting I
c degradation behaviors, and it elaborately determines the reversible limits of I
c induced in the CC tape during testing.
Dark matter produced from neutrinos
Authors: Hufnagel Marco , Xu Xun-Jie
Published: January 2022

In the presence of interactions between neutrinos and dark matter (DM), DM can potentially be produced via freeze-in from the neutrino sector. We investigate the implications of such a scenario for the evolution of both DM and neutrinos in the early Universe, and show that the future cosmic neutrino detection experiment PTOLEMY might be sensitive to neutrino signals that originate from DM annihilation in this model.
Comparison of measurement and simulation of ATLAS cavern radiation background
Authors: Heijne E. , Koi T. , Leroy C. , Oberlack H. , Pospisil S. , Sherwood P. , Shupe M. , Solc J. , Suk M. , Takai H. , Turecek D. , Vykydal Z. , Young Ch.
Published: January 2022

Sixteen Medipix2 pixel detector based (MPX) devices were
operated at various positions within the ATLAS detector and cavern
continuously from early 2008 up to 2013. In addition to photons,
each MPX detector is capable to detect charged particles, and
neutrons as it is covered with a mask of converter materials
dividing its area into regions sensitive to thermal or fast
neutrons. The MPX detector network was effectively used for
real-time measurements of the spectral characteristics and
composition of complex radiation fields in ATLAS. This article
reports comparison of the results of measurements performed with MPX
detectors during the LHC operation period in 2010 and 2011 with
Monte Carlo simulations results from the FLUGG and GCALOR codes. For
the purpose of this comparison, the MPX detectors were operated in
tracking mode with low threshold (8–10 keV) allowing one to
distinguish among particle categories based on the recognition of
track patterns left by the particles in the MPX sensitive layer. The
comparison of measurements with simulations shows that the agreement
between measured and simulated data is satisfactory in most cases
within a factor of two.
A 30 m global map of elevation with forests and buildings removed
Authors: Hawker Laurence , Uhe Peter , Paulo Luntadila , Sosa Jeison , Savage James , Sampson Christopher , Neal Jeffrey
Published: January 2022

Elevation data are fundamental to many applications, especially in geosciences. The latest global elevation data contains forest and building artifacts that limit its usefulness for applications that require precise terrain heights, in particular flood simulation. Here, we use machine learning to remove buildings and forests from the Copernicus Digital Elevation Model to produce, for the first time, a global map of elevation with buildings and forests removed at 1 arc second (∼30 m) grid spacing. We train our correction algorithm on a unique set of reference elevation data from 12 countries, covering a wide range of climate zones and urban extents. Hence, this approach has much wider applicability compared to previous DEMs trained on data from a single country. Our method reduces mean absolute vertical error in built-up areas from 1.61 to 1.12 m, and in forests from 5.15 to 2.88 m. The new elevation map is more accurate than existing global elevation maps and will strengthen applications and models where high quality global terrain information is required.
Intensive milk production technologies on a modern complex
Authors: Lyashenko V V , Kaeshova I V , Gubina A V , Chupsheva N Y
Published: January 2022

The article presents the results of research confirming the influence of intensive technologies used in modern dairy complexes on the level of reproduction and productivity of milking herds. It is noted that when heifers are bred intensively in the specialized farm, at the first successful insemination the animals reach a high live weight (350-360 kg) at the age of 330-340 days. A high efficiency of intensive technology of dairy herd reproduction using sexed semen has been established. Thus, the pregnancy rate of heifers from the first insemination was 61.5% and that of cows of the first lactation, taking into account their health condition and the diseases they had undergone, was 41.1%. During calving, 82.9 - 94.3% of replacement heifers were obtained from the control stock of heifers and cows of the first lactation. Researches have shown that intensive technologies of the maintenance, feeding and reproduction herd realized on modern dairy complex provide high milk productivity of animals (the level of milk yield 10,240 kg of milk, mass fraction of fat in milk - 3.98% and that of protein - 3.17%). In the herd more than 3% of animals completed the sixth lactation (the level of milk yield - 9,940 kg of milk, the mass fraction of fat in milk - 4.35% and protein - 3.2%), which demonstrates the prospects of forming the dairy herd with a long period of economic use of cows. Consequently, intensive milk production technologies in modern complexes contribute to the increase of productivity of young cattle and milking cows, ensure high efficiency of reproduction of the dairy herd and, to a certain extent, increase the duration of productive use of animals.
Biological characteristics of Russian black pied cattle
Authors: Shishkina T V , Guseva T A , Nikishova N V , Naumov A A
Published: January 2022

The biological characteristics of farm animals depend on their species and breed differences, but at the same time they are subject to certain variability due to individual heredity. In this regard, from the number of first-calf cows (daughters of different bulls) eight groups of the same age cows were organized and examined. In addition, a group of 65 animals was formed to assess the exterior by the method of random sampling without taking into account their heredity. The current research is aimed to evaluate the first-calf cows in the following options: milk productivity, functional properties of the udder, body type and the main disadvantages of the exterior. As a result of the analysis, Alta Genetics cows showed the best milk productivity among other breeds. The cows of Alta Gost and Alta Samuari breeds turned out to have the best indicators for a number of economically useful traits. The AltaGost cows were characterized by the best milk yield. When assessing the exterior features and constitution, it was found that the greatest number of conformation defects is associated with the limbs: close hocks (35%); wide interdigital cleft (71%); narrow hoof (22%). Nevertheless, a visual assessment of a complex of features allows to refer all the examined cows to a good body type.
Characteristics of the adaptive properties of winter soft wheat varieties in the conditions of the Middle Volga region
Authors: Koshelyaev V V , Koshelyaeva I P , Karpova L V , Karpova G A
Published: January 2022

The paper deals with the obtained results of examining the adaptive properties of winter wheat varieties cultivated in the seventh (Middle Volga) region of the Russian Federation. The following varieties were taken as the object of the current research: Bezenchukskaya 380, Nemchinovskaya 57, Scepter, Moskovskaya 56, Fotinya, Klaudia 2. This research was carried out with the aim to improve the efficiency of grain production. The chosen varieties had been studying at six levels of mineral nutrition over three years. The indicators obtained by years of research (without fertilization), characterizing the attitude of genotypes to the conditions prevailing during the growing season of crops, were considered as the influence of unregulated environmental factors. The indicators obtained during the application of fertilizers were assessed as controlled environmental factors. The adaptive properties of winter wheat varieties were assessed by indicators characterizing potential adaptability or potential productivity, resistance to stress and the intensity of reaction to favorable environmental conditions. Taking into consideration the adaptive properties of the winter wheat varieties, it was found that they are mainly potentially productive forms, but varieties differ significantly in stress resistance and reaction to favorable environmental conditions. As a result of a comprehensive assessment, conclusions were made about the advisability of using a particular variety in technologies with different levels of cultivation intensity. Firstly, the varieties such as Bezenchukskaya 380, Fotinya and Claudia 2 should be used in technologies of moderate intensity. Secondly, it would be more efficient to cultivate the varieties Nemchinovskaya 57 and Scepter using intensive technologies. Thirdly, the variety Moskovskaya 56 could be cultivated with applying both moderate and high-intensity technologies.
Achieving the balance of macronutrients with the No-till technology in the cultivation of agricultural crops with microbiological fertilizers
Authors: Chekaev N P , Blinokhvatova Yu V , Nushtaeva A V , Kuznetsov A Yu
Published: January 2022

The current research provides data on the change in the agrochemical parameters of soils with the No-till technology. The results, obtained from the agrochemical examination of the farm’s soils, show that the No-till technology reduces the degradation processes in the soils. In the soils of land plots where the No-till technology is applied, the nutrients are differentiated according to the conditions, while an increase in the content of macronutrients in the upper fifteen-centimeter soil layer is observed. In terms of the content of microelements, no clear differentiation in soil depth was found over a ten-year period. An analysis of the data obtained on the application of microbiological fertilizers on the content of nutrients in plants during the period of their maximum accumulation suggests that there is a slight increase in the nitrogen content in plants. The greatest effect on this indicator was revealed with the combined application of the following fertilizers: Azotovit, Fosfotovit (an increase of 0.51%), and BioAzFK (an increase of 0.22%). The yields of spring wheat with the application of microbiological fertilizers increased by 12.0-45.0%. Under the conditions of the pesticidal seed treatment with the fertilizers containing tebuconazole, fluxapiroxade, and thiamethoxam, the yields increased by 19.0-38.0%.
Biological resources of water bodies in the Volga region, formed by water retaining structures as exemplified by the Gorodskoye water reservoir in Penza region
Authors: Asanov A Y , Galiullin A A , Kalinichev E A
Published: January 2022

Along with classic reservoirs and ponds located on middle and small streams of the Volga region, there is a large number of partially regulated river channels formed by water retaining structures and other artificial obstacles, which differ significantly from natural channels by morphometric and hydrological parameters, which allows to classify them into a separate type of water bodies - channel-type water reservoirs. The article considers the condition of aquatic bioresources in such reservoirs on the example of the largest in the Penza region - “Gorodskoye” on the river Sura in comparison with the classic reservoir Surskoye (Penzenskoye) (on the river Sura) and the natural riverbed itself. The analysis of fish production by food components showed that with equal depth per hectare the highest fish production by “soft” zoobenthos, mollusks, zooplankton is observed in the Gorodskoye reservoir, by phytoplankton - in the Surskoye reservoir. Taking into account the average depth of reservoirs, where the Gorodskoye reservoir is in the middle position, it is not much inferior to the Surskoye reservoir in terms of fish food production. Ichthyomass of fishery stock of the Gorodskoye reservoir is three times higher than that of the Sura river channel and 25% lower than that of the Surskoye reservoir with its large fattening areas and depths. Accordingly, the channel impoundments are close to classic reservoirs in terms of aquatic bioresources status and therefore cannot be considered alongside natural river channels. They require a separate study, use and special fishery status. Accounting for aquatic bioresources in such reservoirs and carrying out reproductive measures makes it possible to significantly increase catch quotas for commercial fish species in such low-water regions as Penza region.
The microorganisms natural consortia effectiveness in the white cabbage crop cultivation
Authors: Markarova A E , Markarova M Yu , Razin O A , Nadezhkin S M
Published: January 2022

The research on effectiveness of microbial consortia with growth-regulating and anti-pathogenic functions on the yield and quality of white cabbage had been carried out in the field conditions for 2 years. It was obtained that under N90P120K150, the use of the experimental biofungicide Tridem promoted an increase in nitrogen-fixing activity in the soil and a decrease in the infectious conditions in the rhizosphere under cabbage hybrids. The use of the experimental microbial complex BIS provided an increase in the mass of heads of cabbage, the accumulation of biologically active substances in them, and contributed to an increase in the biodiversity of soil microbiota. The combined use of the biofungicide Tridem and the microbial complex BIS stimulated an increase in yield, had a positive effect on the quality of cabbage and contributed to a decrease in the number of pathogenic fungi and bacteria in the soil under cabbage.
Changes in soil fertility and productivity of agricultural crops under the aftereffect of urban sewage sludge and zeolite
Authors: Kuzin E N , Arefiev A N , Kuzina E E , Vlasova T A
Published: January 2022

The current research deals with the influence of the aftereffect of zeolite-containing agro-ore, sewage sludge from the city of Penza and their combinations on the total carbon content, agronomically valuable water-resistant aggregates in the arable layer, the efficiency of moisture use by plants and the productivity of agricultural crops. It was determined that the highest effect on meadow-chernozemic low-humus medium-thick leached soil in this case was provided by the aftereffect of increased rates of precipitation of urban wastewater (160-180 t/ha) in combination with zeolite-containing agro-ore. The content of total carbon in the arable layer in these variants of the experiment in the agrocenosis of winter wheat (2020) was 3.109-3.121%, significantly exceeding the initial values by 0.157-0.169%. The number of agronomically valuable water-resistant aggregates in the arable layer under observed conditions was equal to 59.6-60.5% at the end of the research, exceeding the initial values by 21.0-22.0%. The water consumption coefficient in the oat agrocenosis was 544.7-547.2 m3/t, in the pea agrocenosis 683.8-686.9 m3/t, in the winter wheat agrocenosis 558.1-560.8 m3/t, exceeded the control in 2018 by 162.2-164.7 m3/t, in 2019 by 260.7-263.8 m3/t, in 2020 by 141.7-144.4 m3/t. The total productivity of Konkur oats, Jackpot peas, Moskovskaya 56 winter wheat variety under the aftereffect of urban wastewater precipitation at rates of 160 and 180 t/ha was 12.83-12.91 t/ha per unit, exceeding the control by 3.64-3.72 t/ha per unit, or 39.6-40.5%.
Comparison of fatigue damage criteria for a CFRP aeronautical joint subjected to random fatigue load
Authors: Castriota A , Dattoma V , Nobile R
Published: January 2022

The fatigue life prediction of components in CFRP subjected to random fatigue load was carried out considering different fatigue damage models. The selected component is a filled hole tension specimen, which is representative of the typical aeronautical riveted joint. The stress state of the riveted section was determined through a FEM model, created with CODE ASTER. Subsequently, the fatigue load history was introduced, calculating the stress field for the different load levels. Applying the constant life diagrams, fatigue cycles were counted and the damage was evaluated. Finally, the damage that occurs in the different ply of the specimen was calculated using different fatigue damage criteria present in literature. The creation of a parametric FEM model offers the possibility of optimizing the study and constitutes a useful tool in order to choose the most suitable damage criteria for the particular geometry and loading mode of the component. Moreover, different severity of the load history and different load sequence were introduced to show their effect in the fatigue failure.
A comparison on the Energy Release between traditional and Additive Manufactured AISI 316L steel during static tensile test
Authors: D’Andrea D , Guglielmino E , Risitano G , Santonocito D
Published: January 2022

Additive Manufacturing (AM) allows the creation of mechanical components and biomechanical devices with low weight and reduced material consumption compared to traditional manufacturing techniques. Despite design opportunities increase, on the other hand, also the process parameters to consider when dealing with AM are relevant on the mechanical performance. It is of fundamental importance to assure the structural integrity and reliability of such components. Energy release could give relevant information on the mechanical performance of the material; hence the Static Thermographic Method (STM) has been proposed as a rapid test procedure to assess the initiation of damage within the material monitoring the temperature evolution during static tensile tests. The aim of the present work is to compare the energy release of a stainless steel during static tensile tests. Specimens made of AISI 316L were produced with the same geometry, both with traditional and AM techniques. A comparison on the microstructure has been also performed in order to assess the possible cause of failure under static loads.
A first quantitative approach for detecting volumetric defects in additive manufactured metal samples by using active thermographic technique
Authors: D’Accardi Ester , Palumbo Davide , Errico Vito , Fusco Andrea , Galietti Umberto
Published: January 2022

This work is focused on the quantitative analysis of defects produced in metal samples of AISI 316L with Laser Powder Bed Fusion (L-PBF) additive manufacturing (AM) process by means of active thermographic techniques. A simple and common set-up with 2 flash lamps and a cooled sensor has been used to analyse the differences between planar and volumetric defects. In particular, the presence of imprinted spheres containing inside non-sintered metallic powder has been compared with those of similar cylinders in size and depth, induced in similar samples. Furthermore, the differences in terms of thermal contrasts have been studied between the cylinder manufactured as an internal defect with powder inside, against the same geometry, but with a small channel for the discharge of the non-melted material. The analysis of the thermal signal and the application of post processing algorithms allowed us to identify the thermal features suitable for describing the behaviour of different kind of defects, typical of the process.
Finite element design of the connection of barriers for the protection of crowded places
Authors: Arcieri E V , Baragetti S
Published: January 2022

The terrorist attacks in Europe have highlighted the problem of safety in public places. It is enough to run a vehicle at high speed towards the crowd to cause a large number of injuries and victims. In response to these phenomena, the Municipalities have perimetered sensitive areas with protection tools. The authors of this work have already designed a mobile anti-terrorism barrier capable of stopping 3500 kg and 7500 kg vehicles with a speed of 64 km/h in a few meters. In this work, the connection of two barriers by ropes is designed using Finite Element (FE) method to perimeter large areas with a small number of devices. Steel and Dyneema® ropes are studied, discussing the number of ropes and the dimensions needed.
The contact problem in FEM analysis of filiform structure for large deployable reflectors
Authors: Guglielmini R , Marotta E , Salvini P
Published: January 2022

Space reflectors need a continuous increase of size to improve the quality of the communication. Considering the small space available in launchers, the antenna must be assembled within the vector and deployed in the space environment. The antenna requires a thin metallic mesh sustained by an appropriate net structure. The best reflector efficiency is reached when all the metallic wires keep in stable contact, allowing the electrical field to be homogeneous. The number of wires involved is enormous, so that, the modelling requires a simple structural approach connected to a reliable contact tool. Single wires can be modelled by beams, but this opens a non-trivial contact managing. As a matter of fact, the wires describe a thin surface, but the contact is realized by 3D crossing. This point is the main objective of the present work which suggests a way to overcome the crossing while maintaining the structure modelling in a 2D field. The contact efficiency needs that the wires do not exceed the elastic strength, causing a lowering of loading contacts due to irreversible deformations. Taking advantage of the present approach, an investigation over the percentage of active contacts in a full mesh is performed, so that optimally applied tensile loads are identified.
Holistic eco-design tool within automotive field
Authors: Antonacci A , Del Pero F , Baldanzini N , Delogu M
Published: January 2022

In the last decades, sustainability has become a critical issue for the vehicle industry. Today automotive manufacturers are subjected to several government regulations aimed at making the industry more environmentally sustainable. In this context, many research and industrial activities are focused on the eco-design field by developing innovative materials, novel manufacturing technologies, and new methodology; the main objective is to combine the best design performance with increased environmental responsibility. In this paper, a holistic design and sustainability analysis method based on a multi-criteria approach is presented to support the designer in the early conceptual phase finding the best trade-off in terms of performance and sustainability. The new methodology generates a single-score index (SSI) based on product design/sustainability metrics; data normalization, weighting, and aggregation processes are also included in the evaluation method. This method is integrated into an eco-design framework developed through HyperWorks and MATLAB software tools. A case study, based on a reference geometry, a load case, and a list of materials and processes chosen by the designer, is described to show the potential of the proposed methodology. Finally, a critical review and concluding remarks are described following the SSI results; suggestions for further improvements are made.