bluuebunny/crossref_metadata_2025 huggingface dataset:
Estrategias de cortesía y valoraciones negativas en el comercio electrónico
Authors: Peng Shuo , Moreno Carrero Carlos Antonio
Published: December 2021

Las valoraciones negativas escritas por los clientes de productos y servicios adquiridos a través de Internet se han convertido en una poderosa herramienta a favor del consumidor. Gracias a esta, dichos consumidores expresan, generalmente, sus quejas ante la falta de adecuación entre el producto descrito y el producto finalmente obtenido, y que revierte en la imagen de la empresa que las recibe. En el marco de la cortesía lingüística y basándonos en un corpus compuesto por seiscientas opiniones negativas recogidas en la página web de Amazon, el presente trabajo analiza contrastivamente las estrategias de cortesía empleadas en las valoraciones negativas de consumidores chinos y españoles acentuando una perspectiva sociocultural y combinando una metodología tanto cualitativa como cuantitativa. El estudio revelará cómo las estrategias de cortesía chinas están orientadas hacia la construcción de una imagen positiva mientras que las españolas se encaminan a una imagen negativa. También se desprende de la investigación un análisis de algunos cambios en los modelos de cortesía verbal con respecto a la cortesía convencional.
Failures in thymus medulla regeneration during immune recovery cause tolerance loss and prime recipients for auto-GVHD
Authors: Alawam Abdullah S. , Cosway Emilie J. , James Kieran D. , Lucas Beth , Bacon Andrea , Parnell Sonia M. , White Andrea J. , Jenkinson William E. , Anderson Graham
Published: December 2021

Bone marrow transplantation (BMT) is a widely used therapy for blood cancers and primary immunodeficiency. Following transplant, the thymus plays a key role in immune reconstitution by generating a naive αβT cell pool from transplant-derived progenitors. While donor-derived thymopoiesis during the early post-transplant period is well studied, the ability of the thymus to synchronize T cell development with essential tolerance mechanisms is poorly understood. Using a syngeneic mouse transplant model, we analyzed T cell recovery alongside the regeneration and function of intrathymic microenvironments. We report a specific and prolonged failure in the post-transplant recovery of medullary thymic epithelial cells (mTECs). This manifests as loss of medulla-dependent tolerance mechanisms, including failures in Foxp3+ regulatory T cell development and formation of the intrathymic dendritic cell pool. In addition, defective negative selection enables escape of self-reactive conventional αβT cells that promote autoimmunity. Collectively, we show that post-transplant T cell recovery involves an uncoupling of thymopoiesis from thymic tolerance, which results in autoimmune reconstitution caused by failures in thymic medulla regeneration.
Hamiltonian analysis and positivity of a new massive spin-2 model
Authors: dos Santos Alessandro L R , Dalmazi Denis , de Paula Wayne
Published: December 2021

Recently a new model has been proposed to describe free massive spin-2 particles in D dimensions in terms of a non symmetric rank-2 tensor e

μν
and a mixed symmetry tensor B

μ[αβ]. The model is invariant under linearized diffeomorphisms without Stueckelberg fields. It resembles a spin-2 version of the topologically massive spin-1 BF model (Cremmer–Scherk model). Here we apply the Dirac–Bergmann procedure in order to identify all Hamiltonian constraints and perform a complete counting of degrees of freedom. In D = 3 + 1 we find 5 degrees of freedom corresponding to helicities ±2, ±1, 0 as expected. The positivity of the reduced Hamiltonian is proved by using spin projection operators. We have also proposed a parent action that establishes the duality between the Fierz–Pauli and the new model. The equivalence between gauge invariant correlation functions of both theories is demonstrated.
Dynamical effective field model for interacting ferrofluids: II. The proper relaxation time and effects of dynamic correlations
Authors: Fang Angbo
Published: December 2021

The recently proposed dynamical effective field model (DEFM) is quantitatively accurate for ferrofluid dynamics. It is derived in paper I within the framework of dynamical density functional theory (DDFT) along with a phenomenological description of nonadiabatic effects. However, it remains to clarify how the characteristic rotational relaxation time of a dressed particle, denoted by τ

r
, is quantitatively related to that of a bare particle, denoted by

τ

r

0

. By building macro-micro connections via two different routes, I reveal that under some gentle assumptions τ

r
can be identified with the mean time characterizing long-time rotational self-diffusion. I further introduce two simple but useful integrated correlation factors, describing the effects of quasi-static (adiabatic) and dynamic (nonadiabatic) inter-particle correlations, respectively. In terms of both the dynamic magnetic susceptibility is expressed in an illuminating and elegant form. Remarkably, it shows that the macro-micro connection is established via two successive steps: a dynamical coarse-graining with nonadiabatic effects accounted for by the dynamic factor, followed by equilibrium ensemble averaging captured by the static factor. By analyzing data from Brownian dynamics simulations on monodisperse interacting ferrofluids, I find

τ

r

/

τ

r

0

is, somehow unexpectedly, insensitive to changes of particle volume fraction. A physical picture is proposed to explain it. Furthermore, an empirical formula is proposed to characterize the dependence of

τ

r

/

τ

r

0

on dipole-dipole interaction strength. The DEFM supplemented with this formula leads to parameter-free predictions in good agreement with results from Brownian dynamics simulations. The theoretical developments presented in this paper may have important consequences to studies of ferrofluid dynamics in particular and other systems modeled by DDFTs in general.
Electronic structure, phonons and optical properties of baryte type scintillators TlXO4 (X = Cl, Br)
Authors: Mukherjee Supratik , T Aiswarya , Mondal Subrata , Vaitheeswaran G
Published: December 2021

This article thoroughly addresses the structural, mechanical, vibrational, electronic band structure and the optical properties of the unexplored thallous perchlorate and perbromate from ab initio calculations. The zone centered vibrational phonon frequencies shows, there is a blue shift in the mid and high frequency range from Cl → Br due to change in mass and force constant with respect to oxygen atom. From the band structure it is clear that the top of the valence band is due to thallium s states, whereas the bottom of the conduction band is due to halogen s and oxygen p states, showing similar magnitude of dispersion and exhibits a charge transfer character. These characteristics and the band gap obtained are consistent with that of a favourable scintillators. Our findings deliver directions for the design of efficient TlXO4 based scintillators with high performance which are desirable for distinct applications such as medical imaging, high energy physics experiments, nuclear security.
Trimetallic metal-organic frameworks (Fe, Co, Ni-MOF) derived as efficient electrochemical determination for ultra-micro imidacloprid in vegetables
Authors: Shu Hui , Lai Tingrun , Ren Jie , Cui Xiuxiu , Tian Xu , Yang Zhichao , Xiao Xuechun , Wang Yude
Published: December 2021

The excessive use of imidacloprid in agricultural production leads to a large number of residues that seriously threaten human health. Therefore, the detection of imidacloprid has become very important. But how to quantitatively detect imidacloprid at ultra-low levels is the main challenges. In this work, trimetallic metal-organic frameworks Fe, Co, Ni-MOF (FCN-MOF) is in situ prepared on nickel foam (NF) and then used to make an electrochemical sensor in the detection of imidacloprid. FCN-MOF exhibits the characteristics of ultra-micro concentration detection for imidacloprid with high specific surface area and rich active metal centers. The high conductivity and 3D skeleton structure of the NF electrode enhance the contact site with imidacloprid and promote the transmission of electrons efficiently. All results show that the prepared electrochemical sensor has the advantages of ultra-low detection limits (0.1 pM), wide linear detection ranges (1–5 × 107 pM) and good sensitivity (132.91 μA pM‒1 cm‒2), as well as good reproducibility, excellent anti-interference ability, and fantastic stability. Meanwhile, the electrochemical sensor is used to determine imidacloprid in lettuce, tomato, and cucumber samples with excellent recovery (90%–102.7%). The novel electrochemical sensor is successfully applied to the ultra-micro detection of imidacloprid in vegetables, which provides a new way for the efficient monitoring of imidacloprid in agriculture.
Pseudo single domain NiZn-γFe2O3 colloidal superparamagnetic nanoparticles for MRI-guided hyperthermia application
Authors: Kim Ji-Wook , Wang Jie , Kim Hyungsub , Bae Seongtae
Published: December 2021

Magnetic resonance imaging (MRI)-guided magnetic nanofluid hyperthermia (MNFH) is highly desirable in cancer treatment because it can allow for diagnosis, therapeutics, and prognosis simultaneously. However, the application of currently developed iron-oxide based superparamagnetic nanoparticles (IOSPNPs) for an MRI-guided MNFH agent is technically limited by the low AC heat induction power at the physiologically tolerable range of AC magnetic field (H
AC,safe), and the low transverse r
2-relaxivity responsible for the insufficient heating of cancers, and the low resolution of contrast imaging, respectively. Here, pseudo single domain colloidal Ni
x
Zn1−x
–γFe2O3 (x = 0.6) superparamagnetic nanoparticle (NiZn-γFe2O3 PSD-SPNP) physically and theoretically designed at the H
AC,safe, specifically by the applied frequency, is proposed for a highly enhanced MRI-guided MNFH agent application. The NiZn-γFe2O3 PSD-SPNP showed the superparamagnetic characteristics, significantly enhanced AC heat induction performance (ILP = 6.3 nHm2 kg−1), highly improved saturation magnetization (M

s
= 97 emu g−1 Fe, 3.55 × 105 A m−1) and r
2-relaxivity (r
2 = 396 mM−1 s−1) that are desirable for highly efficient MRI-guided MNFH agent applications. According to the analyzed results, the remarkably enhanced effective relaxation time constant and its dependent out-of-phase magnetic susceptibility, as well as the DC/AC magnetic softness optimized by the PSD-SPNP at the H
AC,safe were revealed as the main physical reason for the significance. All the fundamental in vitro and in vivo experimental results demonstrated that the physically designed NiZn-γFe2O3 PSD-SPNP is bio-technically feasible for a highly efficient MRI-guided MNFH agent for future cancer nanomedicine.
Nanoscale engineering of ring-mounted nanostructure around AAO nanopores for highly sensitive and reliable SERS substrates
Authors: Dong Jun , Wang Yan , Wang Qianying , Cao Yi , Han Qingyan , Gao Wei , Wang Yongkai , Qi Jianxia , Sun Mengtao
Published: December 2021

Surface-enhanced Raman scattering (SERS) is recognized as one of the most favored techniques for enhancing Raman signals. The morphology of the SERS substrate profoundly affects molecular Raman spectra. This study aimed to construct a ring-mounted nanostructured substrate via liquid–liquid two-phase self-assembly incorporated with anodic aluminum oxide (AAO) membrane transfer techniques. High-density nanoparticles (NPs) assembled on AAO membranes were ascribed to reduce the diameters of the nanopores, with Au–Ag alloy NPs to regulate the dielectric constant so as to reveal the local surface plasmon resonance tunability. SERS engineered in this way allowed for the fabrication of a ring-mounted nanostructured substrate where the distribution density of NPs and dielectric constant could be independently fine-tuned. High SERS activity of the substrate was revealed by detecting the enhanced factor of crystal violet and rhodamine 6G molecules, which was up to 1.56 × 106. Moreover, SERS of thiram target molecules confirmed the supersensitivity and repeatability of the substrate as a practical application. The results of this study manifested a low-cost but high-efficiency ring-mounted nanostructured SERS substrate that might be suitable in many fields, including biosensing, medical research, environmental monitoring, and optoelectronics.
A regularized shallow-water waves system with slip-wall boundary conditions in a basin: theory and numerical analysis
Authors: Israwi Samer , Kalisch Henrik , Katsaounis Theodoros , Mitsotakis Dimitrios
Published: December 2021

The simulation of long, nonlinear dispersive waves in bounded domains usually requires the use of slip-wall boundary conditions. Boussinesq systems appearing in the literature are generally not well-posed when such boundary conditions are imposed, or if they are well-posed it is very cumbersome to implement the boundary conditions in numerical approximations. In the present paper a new Boussinesq system is proposed for the study of long waves of small amplitude in a basin when slip-wall boundary conditions are required. The new system is derived using asymptotic techniques under the assumption of small bathymetric variations, and a mathematical proof of well-posedness for the new system is developed. The new system is also solved numerically using a Galerkin finite-element method, where the boundary conditions are imposed with the help of Nitsche’s method. Convergence of the numerical method is analysed, and precise error estimates are provided. The method is then implemented, and the convergence is verified using numerical experiments. Numerical simulations for solitary waves shoaling on a plane slope are also presented. The results are compared to experimental data, and excellent agreement is found.
Theoretical studies of low-frequency Alfvén modes in tokamak plasmas
Authors: Ma Ruirui , Chen Liu , Zonca Fulvio , Li Yueyan , Qiu Zhiyong
Published: December 2021

The linear wave properties of the low-frequency Alfvén modes (LFAMs) observed in the DIII-D tokamak experiments with reversed magnetic shear (Heidbrink et al 2021 Nucl. Fusion
61 016029) are theoretically studied and delineated based on the general fishbone-like dispersion relation. By adopting representative experimental equilibrium parameters, it is found that, in the absence of energetic ions, the LFAM is a reactive-type kinetic ballooning mode instability with a dominant Alfvénic polarization. More specifically, due to diamagnetic and trapped particle effects, the LFAM can be coupled with the beta-induced Alfvén-acoustic mode in the low-frequency region (frequency much less than the thermal-ion transit and/or bounce frequency) or with the beta-induced Alfvén eigenmode in the high-frequency region (frequency higher than or comparable to the thermal-ion transit frequency), resulting in reactive-type instabilities. Moreover, the ‘Christmas light’ and ‘mountain peak’ spectral patterns of LFAMs as well as the dependence of instability drive on the electron temperature observed in the experiments can be theoretically interpreted by varying the relevant physical parameters. Conditions for when dissipative-type instabilities may set in are also discussed.
Geometry effects in topologically confined bilayer graphene loops
Authors: Benchtaber Nassima , Sánchez David , Serra Llorenç
Published: December 2021

We investigate the electronic confinement in bilayer graphene by topological loops of different shapes. These loops are created by lateral gates acting via gap inversion on the two graphene sheets. For large-area loops the spectrum is well described by a quantization rule depending only on the loop perimeter. For small sizes, the spectrum depends on the loop shape. We find that zero-energy states exhibit a characteristic pattern that strongly depends on the spatial symmetry. We show this by considering loops of higher to lower symmetry (circle, square, rectangle and irregular polygon). Interestingly, magnetic field causes valley splittings of the states, an asymmetry between energy reversal states, flux periodicities and the emergence of persistent currents.
Probing the Purcell effect without radiative decay: lessons in the frequency and time domains
Authors: Lindel Frieder , Settembrini Francesca Fabiana , Bennett Robert , Buhmann Stefan Yoshi
Published: December 2021

The effect of cavities or plates upon the electromagnetic quantum vacuum are considered in the context of electro-optic sampling (EOS), revealing how they can be directly studied. These modifications are at the heart of e.g. the Casimir force or the Purcell effect such that a link between EOS of the quantum vacuum and environment-induced vacuum effects is forged. Furthermore, we discuss the microscopic processes underlying EOS of quantum-vacuum fluctuations, leading to an interpretation of these experiments in terms of exchange of virtual photons. With this in mind it is shown how one can reveal the dynamics of vacuum fluctuations by resolving them in the frequency and time domains using EOS experiments.
Development of flow control methods in free and impinging jets
Authors: Shevchenko A K , Yakovenko S N
Published: December 2021

Submerged and impinging jets with harmonic perturbations added to the inlet velocity profile and with nozzle vibrations are simulated numerically at different Reynolds (Re) and Strouhal (St) numbers by solving the Navier–Stokes equations. The effects of Re, St and forcing amplitudes on flow behavior and jet splitting phenomena are studied.
Computational and experimental evaluation of heat transfer intensity in channels of complex configuration for gas flow with different levels of turbulence
Authors: Plotnikov L V , Zhilkin B P , Brodov Yu M , Osipov L E
Published: December 2021

Disclosure of the physical mechanism of the influence of the turbulence intensity of gas flows on the heat transfer level in pipes of different configurations is an urgent task in the field of heat and power engineering. A brief overview of the literature on this topic is given in the article. A description of the boundary conditions for modeling is presented. The main characteristics of the experimental stand and measuring instruments are described. The purpose of this study is to study the effect of the initial turbulence level of a stationary gas flow on the heat transfer intensity in long pipes with different cross sections. The study is carried out using numerical simulation. The simulation results are qualitatively confirmed using experimental data. The values of the local heat transfer coefficient are shown to increase from 5 to 17% with increasing turbulence intensity (from 2 to 10%) in pipes with different cross sections. The heat transfer intensity in a triangular pipe is found to increase up to 30% compared to a round pipe. It is revealed that there is an up to 15% suppression of heat transfer in a square pipe compared to a round pipe. The data obtained may be useful for the design of flow paths and gas exchange systems for power machines and installations.
Investigation of the influence of controls on the flow around the UAV model
Authors: Alpatskiy N S , Pavlenko A M , Bykov A V , Zanin B Y
Published: December 2021

Studies of the flow structure were performed on a trapezoidal UAV model. The experiments were carried out in a wind tunnel at subsonic speeds. The method of soot-oil visualization was used to obtain a picture of the flow around the model. The experiments were made at different angles of attack, as well as at different deflections of the ailerons on the model. The peculiarity of the work is that the experiments were conducted at full-scale (flight) Reynolds numbers.
The effect of microtexture on the liquid flow over the sheets
Authors: Perepelitsa B V
Published: December 2021

This work considers the method of the corrugated sheet arrangement near the column wall with the aim to limit liquid fall on the wall and increase liquid concentration in the near-wall area. Experiments were carried out at the corrugated Koch 1Y packing sheets for various liquid flow rates. This report presents experimental results on the character of liquid flow near the edge of corrugated sheets and the effect of the middle sheet shift from the edge of the packing. The ribs of this sheet are directed downward to the edge of the packing. Test was performed for two positions of the middle sheet: to study the effect of microtexture orientation at the sheet, whose ribs are directed downward to the packing edge, on liquid distribution under the packing. Experiments were carried out for liquid flow rates of 1-12 ml/s.
Control of flow separation over a circular cylinder using synthetic jet
Authors: Lebedev A. S. , Sorokin M. I. , Markovich D. M.
Published: December 2021

The development of methods of active separation flow control is of great applied importance for many technical and engineering applications. Understanding the conditions for the flow separation from the surface of a bluff body is essential for the design of aircrafts, cars, hydro and gas turbines, bridges and buildings. Drag, acoustic noise, vibrations and active flow mixing depend drastically on the parameters of the vortex separation process. We investigated the possibility of reducing the longitudinal length of a reverse-flow region using the method of «synthetic jet» active separation flow control. The experiment was carried out on a compact straight-through wind channel with a 1-m long test section of a cross-section of 125x125 mm. The jet was placed at the rear stagnation point of a circular cylinder. The Reynolds number, based on the cylinder diameter and the free-stream velocity, was 5000 and the von Kármán street shedding frequency without the synthetic jet was equal to 64.8 Hz. For the first time, for such a set of parameters, we applied high speed PIV to demonstrate that the injection of the synthetic jet into the cylinder wake region leads to a significant reduction in the longitudinal length of the reverse-flow region.
Ultra-dispersed particles of water-soluble and water-insoluble substances formed from gas-droplet flows
Authors: Prikhodko V G , Yarygin V N , Yarygin I V
Published: December 2021

The work is devoted to the experimental study of the ultra dispersed particles formation process, which is essentially a fundamental problem of heat and mass transfer in gas-droplet flows under phase transformation conditions. Various methods of generating and controlling the gas-droplet flow parameters are considered. The description of the created equipment and diagnostic methods for studying gas-droplet flows is given. The particle size distribution functions are obtained using an aerosol particle spectrometer. The possibility of controlling the parameters of ultrafine particles of water-soluble and water-insoluble substances (medications) formed under evaporation of microdroplets of solutions and suspensions is shown experimentally. An attempt to reconstruct the distribution functions of microdroplets and their average dimension from measurements of the parameters of ultrafine particles formed after complete evaporation of the droplets is made.
Numerical study of cutting transport using aerated drilling fluids
Authors: Zhigarev V A , Zazulya S O , Minakov A V , Neverov A L
Published: December 2021

The paper deals with drilling fluid flow in a horizontal well during its drilling. As part of this work, rheological parameters of water-based drilling fluid with the addition of polymers and a foaming agent were used. Cuttings transport was studied at different degrees of foam aeration. Besides, the paper presents the study of the effects of drilling fluid flow, as well as the rotation of drill pipes on the cuttings transport.
Analysis of different factors on the features of thermal destruction of a fuel pin
Authors: Usov E V , Saikina T A , Chuhno V I
Published: December 2021

The presented work studies the influence of various factors that affect the specific features of fuel pins melting. For this purpose, fuel pins with different geometries and energy release are considered. Numerical simulation of melting is carried out using a program module for calculating the destruction of fuel rods. Comparison with theoretical calculations is made. The analysis of the convergence of calculations with respect to the time step value and the number of calculated cells along the radius and height is carried out. As a result of work with the use of numerical methods, the characteristic times of destruction of fuel elements during an accident with a loss of coolant flow rate (an accident of the ULOF type) and the dependence of weight loss on time are obtained under various conditions.
Measurement and study of thermophysical properties of nanofluids with carbon nanotubes
Authors: Rudyak V Ya , Dashapilov G R , Shupik A A
Published: December 2021

This article is devoted to the study of the thermophysical properties of nanofluids with single-walled and multi-walled carbon nanotubes (CNT). Their weight concentration varied from 0.05 to 0.2%. Nanofluids, based on ethylene glycol and water, were studied. Dispersants were also used. The diffusion of CNT had been systematically investigated by the method of dynamic light scattering and their effective hydrodynamic dimensions were determined. The rheology and viscosity of all nanofluids were studied. It is shown that nanofluids are either pseu-doplastic or viscoplastic. Their rheology changes with increasing CNT concentration and temperature. However, in all cases, the viscosity of nanofluids with single-walled CNTs is signifi-cantly higher than that of nanofluids with multi-walled CNTs. In the last part, the electrical conductivity of all these nanofluids and the dispersants effect on it are investigated.
Degradation processes in tungsten filaments at high temperatures
Authors: Zakharov Y A , Ghots S S , Sharipov T I , Bakhtizin R Z
Published: December 2021

Degradation processes in tungsten filaments of lighting lamps under normal operating conditions are experimentally studied. The duration of each measurement in continuous mode is about 18 hours. To increase the measurement accuracy, subtraction (compensation) of the constant component of the voltage is used. To compensate for the constant component of the voltage, a low noise reference DC voltage source is used. Using this scheme allowed decreasing the influence of the inherent noise of power supplies without suppressing degradation processes. It is shown that the relative change in resistance during the measurement does not exceed 2.8·10−3. It is also shown that the joint influence of voltage fluctuations of power supplies and low noise reference voltage source on the measurement results corresponds to a relative change in a resistance equal to 2.8·10−4. The study of degradation processes can be used to assess the reliability (and durability) of products in electrical engineering and radio electronics.
Numerical study of a case of the free discharge of water through the turbine with a braked runner
Authors: Platonov D V , Minakov A V , Sentyabov A V
Published: December 2021

The paper presents a numerical study of the free discharge of water through the turbine with a braked runner. The simulation was carried out for a unit of a full-scale Francis turbine. The finite volume method was employed for unstructured meshes using the DES method. The simulation results show the flow structures, integral characteristics, and pressure pulsations in the flow path. The analysis of the applicability of this approach to real conditions is carried out.
1D modelling and PID control of helicopter Diesel engine rotational speed in torque changes
Authors: Magryta P
Published: December 2021

The article discusses the results of simulation tests concerning the operation of a diesel engine for a light helicopter. The tests were carried out in the AVL Boost software which is used to analyze dynamic phenomena in internal combustion engines. The research object was a newly designed diesel engine of a V8 structure and a power of 330 kW. This engine was designed to be used in the construction of a light class helicopter. The created one-dimensional simulation model included all the main engine components as well as the connection to the helicopter main transmission and the helicopter rotor. The tests consisted in selecting the P value in the PID controller used to control the amount of fuel injected into the engine. The change in the P value indirectly influenced the reaction of the engine to a change in power and torque during horizontal flight of a helicopter. These changes were introduced by changing thrust torque in the helicopter rotor. The fuel injection regulator was designed to maintain a constant engine rotational speed. The maximum speed deviations from the nominal speed of the engine operation due to both increasing and decreasing speed were analyzed. Additionally, the sum of the deviation values was analyzed until the rotational speed of the tested object stabilized. The results showed that the change of the P parameter affects all the analyzed parameters of the engine operation; however, the minimum deviation values for each parameter occur at non-equal PID settings, which makes it difficult to clearly indicate the appropriate value of the P element.
Internet of Things as an element of the frost protection system in orchards
Authors: Awtoniuk M , Nowakowski T , Chlebowski J , Świętochowski A , Dąbrowska M , Klonowski J , Sypuła M , Strużyk A , Wrona D , Kowalczyk W , Bąk K
Published: December 2021

Frosts cause serious damage to fruit and vegetable crops. In Poland, temperature decreases, and the occurrence of inflow (advective) frosts most often fall during the flowering period, i.e., in a phase extremely important for the development of the plant. For orchards, this causes the inflorescences of early flowering trees (cherries, plums and certain varieties of apple and pear trees) to freeze. A modern idea for reducing frost losses in orchards is to heat the air with mobile heaters. Protection by these machines consists of passing using an agricultural tractor in rows of trees or shrubs and heating and mixing the air. The problem that farmers may encounter during frosts is the awareness of when exactly such a weather condition occurs in their orchard. Weather forecasts are not detailed and usually apply to the entire region. Dangerous temperature declines below the critical minimum can occur locally and are also conditioned by geographical location and terrain diversity. The aim of the article is to present a measuring system that allows the construction of an individualised temperature model taking into account the unique shape of the orchard surface. The system is made in Internet of Things technology using long-range radio communication protocol LoRaWAN. Data from distributed measurement sensors are processed on a network server and displayed as a final application. The task of the system is to monitor the current situation in the orchard and to notify the farmer of the need to initiate a protective procedure. The operation of the system also supports the efficient use of mobile heating machines. The system facilitates the location of the areas in the orchard with the lowest temperature, as well as provides feedback on temperature changes inside the treetops caused by the passage of the mobile heater.
Finite element modeling of coupling characteristics of directional coupler for multiplexer and de-multiplexer application
Authors: Mohammed M
Published: December 2021

Numerical simulation of directional coupler that is based on the finite element method was conducted using the COMSOL Multiphysics software. The distributions of electric field and power flow of light propagates in two cores of directional coupler were analyzed. The results showed the dependencies of coupling length and maximum transfer power between cores on the cores separation and the wavelength, the characteristic of a subwavelength directional coupler can be used for photonic integrated circuits. Asymmetric directional coupler was also designed by changing in the device dimension, as the core width. The variation of coupling length with the core width were analysed. It was found that the power switching between cores is reduced when introducing a small difference in the one core width of directional coupler, followed by increased coupling length. At the same time, the coupling length can be decreased efficiently by increasing the difference in one core width; therefore, a directional coupler with large core width is more convenient to reduce the power switching between cores than the smaller core width. This study is useful for determining the coupling characteristics between the cores that may be used as a platform for future photonic integrated circuits in optical communication systems.
Water efficiency management systems for transport drinking water supply
Authors: Cvelihárová D , Pauliková A
Published: December 2021

The quantity of management systems standards (MSSs) is increasing every year. Standards are significantly associated with common requirements and differences for many providers of services as well as for manufactures. The drinking water supply management system is certainly one of the important services. The aim of this article is to introduce a basic application of management system (MS) using visual management. The standard applied in a model, defined as a complex solitaire or “singlet”, is the Water Efficiency Management Systems (WEMS) standard. Visualised model is built by creating clusters using a software program designated for Small World Networks. This phase is preceded by the compilation of Excel spreadsheets, where requirements are divided into common and specific ones. The resulting cluster of selected areas includes the context of organizations that provide services, considering the common and specific requirements of interesting parties, managing their leadership, planning, support, operation, performance evaluation and improvement. It could be very useful to extend the cluster by another standard depending on the needs of the drinking water supplier and the transport piping systems at the site. This approach to management systems intensively clarifies managerial decision-making processes related to the implementation of the WEMS.
Climate change, fires and their impact on safety
Authors: Heinzová Z , Kubrická K , Podkul M , Pokorný J
Published: December 2021

Our planet is warming due to climate change. Along with this, the incidence of fires is increasing. Fires negatively affect the environment. Fire prevention is one of the safety priorities in the Czech Republic and in the world. One aspect of safety is the evacuation of people, animals and potentially property. The paper will present a case study of escape route ventilation.
Technical condition of sewer networks in the Czech Republic
Authors: Hlustik P , Singrova V
Published: December 2021

This article offers a comparison of the detected defects in sewerage systems operated by water companies and by self-operators, determines their quantity and classifies them into individual categories. The determination of the number of the defects at self-operators is evaluated on the basis of performed camera inspections and compared with data provided by the water company.
Use of vegetation for the removal of pollutants from wastewater as an alternative environmental technique for wastewater treatment
Authors: Junakova N , Junak J
Published: December 2021

The paper focuses on the evaluation of the use of vegetation for the removal of contaminants from wastewater through vegetation-based wastewater treatment plants. Subsequently, the specific efficiencies of wastewater treatment using a selected vegetation-based wastewater treatment plant are evaluated. The results show that vegetation-based wastewater treatment plants generally work at relatively high treatment efficiency, but one of the main factors influencing the treatment efficiency is the values of pollution indicators at the inflow to the wastewater treatment plant.
Fungicidal effects on cement composites with recycled glass from photovoltaic panels
Authors: Kučová K , Máčalová K , Václavík V , Dvorský T , Vašinková M
Published: December 2021

This research was focused on the effects of micromycetes on cement composites with 100% replacement of natural aggregate by the recycled glass from photovoltaic panels. The experiment was performed on samples of small beams measuring 40 x 40 x 8 mm (length x width x height) and cement crumbling with recycled glass from photovoltaic panels in percentages representing 10%, 20% and 40%. The representatives of the selected micromycetes were Aspergillus
niger, A. clavatus, Penicillium
glabrum, Cladosporium sp. and Zygomycetes sp. Biocorrosion causes changes in the properties of the material, mainly as a result of the action of microorganisms. Due to their large production of acids and enzymes, micromycetes are an important part of microscopic consortia involved in biocorrosion. This experiment focused on evaluating the effect of micromycetes on cement composites – solid structure and crumbling, with 100% replacement of natural aggregate with photovoltaic glass recyclate. The results show a high growth of biomass on solid composites, while on cement crumbling, the growth was minimal due to high pH value. Longer monitoring time was used in case of adaptation to the environment.
Waste production and waste management in the EU
Authors: Matušková S , Taušová M , Domaracká L , Tauš P
Published: December 2021

The constant growth of the population increases the demands on raw material resources, which is reflected in increasing pressure on the environment. The impact of mankind on the environment is nowadays an increasingly acute problem, which is being addressed by the governments of individual countries, not only the EU, through legislative interventions. The most addressed areas are the issue of production and subsequent waste management. Waste production in the world has been growing for a long time, which causes considerable problems for individual countries. Each country is currently looking for the optimal way of waste management to reuse it as secondary raw material. In this paper, we analysed twenty-eight EU countries in terms of production and waste management and found significant differences between countries. We looked for factors that lead to different results between countries in the production and management of waste, based on the population, the size of the country to the indicators of living standards, and legislation applicable to those countries.
Wastewater recycling and the possibility of its technical use in practice
Authors: Ondrasik F , Krocova S
Published: December 2021

In real practice, almost half of the water, after its technical or technological use in various degrees of pollution, is drained by sewerage systems to wastewater treatment plants and subsequently discharged into the recipients of rivers and streams. The current and especially the future method of urban and industrial wastewater treatment is at such a high level that the treated water, before its discharge into the recipients, has a higher degree of quality than the flowing surface water in the watercourse. Under these ever-improving conditions and possibilities, it is appropriate to use well-treated wastewater not only for the needs of agriculture, but also as an alternative supply of fire water for fire purposes. The dislocation of wastewater treatment plants (hereinafter WWTP) in territorial cadastres with safe access to the opened level of treated water allows its relatively rapid pumping at any time, especially in conditions where there is no other suitable natural or multipurpose source of fire water. The following article suggests in a basic way how to use the given options without the risk that the treated wastewater will not endanger the health of fire brigades or will not have the negative impact on the environment of the extinguished building and its surroundings in which the fire is extinguished.
Environmental urbanism and sustainable cities
Authors: Ostárek M
Published: December 2021

The paper focuses on the links between sustainability and urbanism with a focus on the environment. In order to achieve the sustainability of cities, it is necessary to monitor the balance between economic, social and environmental interests, and urbanization is closely linked to this. Urbanism with a focus on the environment or ecological urbanism is a type that focuses on projects in ecological aspects, such as humidification, temperature reduction in the city, energy buildings, planting, urban surfaces, etc. Sustainability of cities is also one of the topics of the United Nations which generally addresses Sustainable Development Goals. In order to achieve the goal of sustainable cities, it is necessary to ensure access to trouble-free and affordable housing and services for all citizens by 2030. This development program is set for the time period 2015-2030. As far as the city is concerned, this in itself fundamentally affects the quality of the surrounding environment, especially interventions in undeveloped areas, land use and city administration. Spatial urban development is also focused in detail on searching and regeneration of unused areas which can have a negative impact in the form of slower growth or decline. The newly emerging BIM method, which demonstrably streamlines the management and development of cities, can also contribute to overall sustainability which further leads to the concept of smart cities. It is a concept of smart cities of urban development that moves to the sectors of management, energy, environment, infrastructure and population in an effort to streamline the management and development of cities using new methods. The result of the work is to show cities as the powerful player in reducing of greenhouse gas emissions which can help to build more liveable environment. Cities are not the biggest problem but the biggest opportunity for change.
Microsimulation of pedestrian conflict with other transport modes
Authors: Růžička J , Kruntorád J , Rek R
Published: December 2021

An effective solution of the conflict points of different transport modes is a significant issue at the urban level today. With the permanent increase of traffic in cities, it is necessary to look for suitable and sustainable transport solutions to these situations, so that the traffic flow is smooth and the transport remains safe, ecological and economical. The paper deals with the design of a simple decision-making tool for selecting the solution of pedestrian conflict with other traffic modes (classical pedestrian crossing, controlled pedestrian crossing for defined pedestrian and vehicle flows, based on experimental microsimulation. High pedestrian flows their dependence on the delay time of road users are not properly implemented in Czech legislation. The results are verified in a case study of conflict solution within the reconstruction of a public transport terminal in Prague.
Evaluation of urban water networks - Case study
Authors: Teichmann M , Kuta D , Szeligova N , Kuda F
Published: December 2021

The subject of the paper is the elaboration of the topic of modeling and optimization of the reliability of systems for drinking water supply in the town of Hlucin and the adjacent villages Bobrovniky and Darkovicky. The paper points out modern ways of management and maintenance of these buildings, eg in the form of passportization, unification of various types of documentation, records of failures and accidents, etc. The aim is to point out possible ways to optimize these buildings and overall evaluation of the water supply network, including the suitable renewal schedule design. These practices are essential for the efficient operation of water supply networks, especially nowadays, when there is a shortage of water and it is necessary to promote sustainable urban development through its economical management.
Performance of reservoir computing in a random network of single-walled carbon nanotubes complexed with polyoxometalate
Authors: Akai-Kasaya Megumi , Takeshima Yuki , Kan Shaohua , Nakajima Kohei , Oya Takahide , Asai Tetsuya
Published: December 2021

Molecular neuromorphic devices are composed of a random and extremely dense network of single-walled carbon nanotubes (SWNTs) complexed with polyoxometalate (POM). Such devices are expected to have the rudimentary ability of reservoir computing (RC), which utilizes signal response dynamics and a certain degree of network complexity. In this study, we performed RC using multiple signals collected from a SWNT/POM random network. The signals showed a nonlinear response with wide diversity originating from the network complexity. The performance of RC was evaluated for various tasks such as waveform reconstruction, a nonlinear autoregressive model, and memory capacity. The obtained results indicated its high capability as a nonlinear dynamical system, capable of information processing incorporated into edge computing in future technologies.
AtANN1 and AtANN2 are involved in phototropism of etiolated hypocotyls of Arabidopsis by regulating auxin distribution
Authors: Wang Xiaoxu , Han Lijuan , Yin Hongmin , Zhao Zhenping , Cao Huishu , Shang Zhonglin , Kang Erfang
Published: December 2021

Phototropism is an essential response in some plant organs and features several signalling molecules involved in either photo-sensing or post-sensing responses. Annexins are involved in regulating plant growth and its responses to various stimuli. Here, we provide novel data showing that two members of the Annexin family in Arabidopsis thaliana, AtANN1 and AtANN2, may be involved in the phototropism of etiolated hypocotyls. In wild type, unilateral blue light (BL) induced a strong phototropic response, while red light (RL) only induced a weak response. The responses of single- or double-null mutants of the two annexins, including atann1, atann2 and atann1/atann2, were significantly weaker than those observed in wild type, indicating the involvement of AtANN1 and AtANN2 in BL-induced phototropism. Unilateral BL induced asymmetric distribution of DR5-GFP and PIN3-GFP fluorescence in hypocotyls; notably, fluorescent intensity on the shaded side was markedly stronger than that on the illuminated side. In etiolated atann1, atann2 or atann1/atann2 hypocotyls, unilateral BL-induced asymmetric distributions of DR5-GFP and PIN3-GFP were weakened or impaired. Herein, we suggest that during hypocotyls phototropic response, AtANN1 and AtANN2 may be involved in BL-stimulated signalling by regulating PIN3-charged auxin transport.
Bayesian multivariate probability of success using historical data with type I error rate control
Authors: Alt Ethan M , Psioda Matthew A , Ibrahim Joseph G
Published: December 2021

In clinical trials, it is common to have multiple clinical outcomes (e.g., coprimary endpoints or a primary and multiple secondary endpoints). It is often desirable to establish efficacy in at least one of multiple clinical outcomes, which leads to a multiplicity problem. In the frequentist paradigm, the most popular methods to correct for multiplicity are typically conservative. Moreover, despite guidance from regulators, it is difficult to determine the sample size of a future study with multiple clinical outcomes. In this article, we introduce a Bayesian methodology for multiple testing that asymptotically guarantees type I error control. Using a seemingly unrelated regression model, correlations between outcomes are specifically modeled, which enables inference on the joint posterior distribution of the treatment effects. Simulation results suggest that the proposed Bayesian approach is more powerful than the method of Holm (1979), which is commonly utilized in practice as a more powerful alternative to the ubiquitous Bonferroni correction. We further develop multivariate probability of success, a Bayesian method to robustly determine sample size in the presence of multiple outcomes.