Particles Of Different Nature Research Articles

Proof-of-Principle Direct Measurement of Particle Statistical Phase

The symmetrization postulate in quantum mechanics is formally reflected in the appearance of an exchange phase governing the symmetry of identical-particle global states under particle swapping. Many indirect measurements of this fundamental phase have been reported thus far, but a direct observation has been achieved only recently for photons. Here, we propose a general scheme capable of directly measuring the exchange phase of any type of particle (bosons, fermions, or anyons), exploiting the operational framework of spatially localized operations and classical communication. We experimentally implement it on an all-optical platform, providing a proof of principle for different simulated exchange phases. As a by-product, we supply a direct measurement of the real bosonic exchange phase of photons. Additionally, we analyze the performance of the proposed scheme when mixtures of particles of different nature are injected. Our results confirm the symmetrization tenet and provide a tool to explore it in various scenarios. Finally, we show that the proposed setup is suited to generating indistinguishability-driven $\mathrm{NOON}$ states useful for quantum-enhanced phase estimation.

Study of Marine Particles Using Submersible Digital Holographic Camera during the Arctic Expedition

The paper presents the results of in situ studies of marine particles of different nature using a submersible digital holographic camera (DHC) during the Arctic expedition. It also describes the features, performance specifications, and possibilities of the DHC and the DHC technology. The DHC technology can be used for noninvasive automatic evaluation of spatial and temporal characteristics of plankton, including the distribution of plankton concentrations. The comparison of quantitative analysis of zooplankton net samples and classification results using the DHC revealed that the error of the DHC classification of mesoplankton at the level of the main systematic orders was about 30%. The results of determining the data on the medium, such as water turbidity, according to the radiation shielding factor (degree) by the particles of the Suspension taxon using the DHC technology are presented; the prospects for studying the size of gas bubbles and their volume content according to the Bubble taxon data are shown. The use of holographic data for in situ point estimates is considered.

A global marine particle size distribution dataset obtained with the Underwater Vision Profiler 5

Abstract. Marine particles of different nature are found throughout the global ocean. The term “marine particles” describes detritus aggregates and fecal pellets as well as bacterioplankton, phytoplankton, zooplankton and nekton. Here, we present a global particle size distribution dataset obtained with several Underwater Vision Profiler 5 (UVP5) camera systems. Overall, within the 64 µm to about 50 mm size range covered by the UVP5, detrital particles are the most abundant component of all marine particles; thus, measurements of the particle size distribution with the UVP5 can yield important information on detrital particle dynamics. During deployment, which is possible down to 6000 m depth, the UVP5 images a volume of about 1 L at a frequency of 6 to 20 Hz. Each image is segmented in real time, and size measurements of particles are automatically stored. All UVP5 units used to generate the dataset presented here were inter-calibrated using a UVP5 high-definition unit as reference. Our consistent particle size distribution dataset contains 8805 vertical profiles collected between 19 June 2008 and 23 November 2020. All major ocean basins, as well as the Mediterranean Sea and the Baltic Sea, were sampled. A total of 19 % of all profiles had a maximum sampling depth shallower than 200 dbar, 38 % sampled at least the upper 1000 dbar depth range and 11 % went down to at least 3000 dbar depth. First analysis of the particle size distribution dataset shows that particle abundance is found to be high at high latitudes and in coastal areas where surface productivity or continental inputs are elevated. The lowest values are found in the deep ocean and in the oceanic gyres. Our dataset should be valuable for more in-depth studies that focus on the analysis of regional, temporal and global patterns of particle size distribution and flux as well as for the development and adjustment of regional and global biogeochemical models. The marine particle size distribution dataset (Kiko et al., 2021) is available at https://doi.org/10.1594/PANGAEA.924375.

STRUCTURE FORMATION OF DISPERSED-REINFORCED BUILDING COMPOSITES

Abstract. The results of the study of the mechanism of structure formation of cement compositions reinforced with finely dispersed monofilament are presented in the article. The mechanism of microstructure organization of construction composites was studied on models of dispersed systems, with different qualitative and quantitative composition of linear and dispersed particles. At the same time, restrictions had been placed on particle size – fiber diameter and diameter of dispersed particles are proportional to each other. Study of cracking formation kinetics was carried out on disk-shaped samples made of water-clay and water-cement compositions. Physical and mechanical characteristics of dispersed-reinforced cement stone, including non-reinforced stone, have been defined on prisms-shaped samples of square section with size 40×40×160 mm. The analysis of physical models showed that cluster structures filling with particles of various nature and shape increases structural diversity of entire dispersed system. An inserting of linear particles changes nature of system structure formation. Depending on the characteristics, structural components of the system, substructures are formed, which differ in the periods of their formation and geometric parameters. It has been established that dispersed particles of different nature are structured in different ways into clusters with discrete fibers of different length. Linear particles were more active in the creation of structural aggregates (clusters) comparing to dispersed grains. The impact of highly dispersed fibers on the structure organization of the binder compositions was quantified by the damage coefficient determined on samples of different types. The presence of discrete fibers in the composition of the material leads to modify the qualitative characteristic of compositions cracking formation. Improvement of physical and mechanical properties of the dispersed-reinforced composite confirms the ability of the fiber to change a mechanism of material destruction due to a probable deposition of hydration products on monofilaments, to densify and strengthen the interfacial transitional zone.

Features of methods for monitoring the fuel cladding tightness in lead-cooled fast breeder reactors

To timely detect failed fuel elements, a reactor plant should be equipped with a fuel cladding tightness monitoring system (FCTMS). In reactors using a heavy liquid-metal coolant (HLMC), the most efficient way to monitor the fuel cladding tightness is by detecting gaseous fission products (GFP). The article describes the basic principles of constructing a FCTMS in liquid-metal-cooled reactors based on the detection of fission products and delayed neutrons. It is noted that in a reactor plant using a HLMC the fuel cladding tightness is the most efficiently monitored by detecting GFPs. The authors analyze various aspects of the behavior of fission products in a liquid-metal-cooled reactor, such as the movement of GFPs in dissolved and bubble form along the circuit, the sorption of volatile FPs in the lead coolant (LC) and on the surfaces of structural elements, degassing of the GFPs dissolved in the LC, and filtration of cover gas from aerosol particles of different nature. In addition, a general description is given of the conditions for the transfer of GFPs in a LC environment of the reactor being developed. Finally, a mathematical model is presented that makes it possible to determine the calculated activity of reference radionuclides in each reactor unit at any time after the fuel element tightness failure. Based on this model, methods for monitoring the fuel cladding tightness by the gas activity in the gas volumes of the reactor plant will be proposed.

Human adipose tissue-derived mesenchymal stromal cells and their phagocytic capacity.

Mesenchymal stromal cells (MSCs) have evidenced considerable therapeutic potential in numerous clinical fields, especially in tissue regeneration. The immunological characteristics of this cell population include the expression of Toll‐like receptors and mannose receptors, among others. The study objective was to determine whether MSCs have phagocytic capacity against different target particles. We isolated and characterized three human adipose tissue MSC (HAT‐MSC) lines from three patients and analysed their phagocytic capacity by flow cytometry, using fluorescent latex beads, and by transmission electron microscopy, using Escherichia coli, Staphylococcus aureus and Candida albicans as biological materials and latex beads as non‐biological material. The results demonstrate that HAT‐MSCs can phagocyte particles of different nature and size. The percentage of phagocytic cells ranged between 33.8% and 56.2% (mean of 44.37% ± 11.253) according to the cell line, and a high phagocytic index was observed. The high phagocytic capacity observed in MSCs, which have known regenerative potential, may offer an advance in the approach to certain local and systemic infections.

Fabrication of Ring-Shaped Deposits of Polystyrene Microparticles Driven by Thermocapillary Mechanism.

Fabrication of ring-shaped deposits of microparticles on solid surfaces with the desired length scales and morphology of particle arrangements is of great importance when developing modern optical and electronic resonators, chemical sensors, touch screens, field-emission displays, porous materials, and coatings with various functional properties. However, the controlled formation of ring-shaped patterns scaling from a few millimeters up to centimeters with simultaneous control of particle arrangement at the microscale is one of the most challenging problems in advanced materials science and technology. Here, we report a fabrication approach for ring-shaped structures of microparticles on a glass surface that relied on a local thermal impact produced by the subsurface heater and heat sink. Thermocapillary convection in the liquid covering microparticles in combination with evaporative lithography is responsible for the particle transport and the assembling into the ring-shaped patterns. An advantageous feature of this approach is based on the control of thermocapillary flow direction, achieved by changing the sign of the temperature gradient in the liquid, switching between heating and cooling modes. That allows for changing the particle transfer direction to create the ring-shaped deposits and dynamically tune their size and density distribution. We have studied the influence of the power applied to the heat source/sink and the duration of the applied thermal field on the rate of the ring fabrication, the sizes of the ring and the profile of the particle distribution in the ring. The proposed method is flexible to control simultaneously the centimeter scale and microscale processes of transfer and arrangements of particles and can be applied to the fabrication of ring structures of particles of different nature and shape.

Relativistic quantum bouncing particles in a homogeneous gravitational field

In this paper, we study the relativistic effect on the wave functions for a bouncing particle in a gravitational field. Motivated by the equivalence principle, we investigate the Klein–Gordon and Dirac equations in Rindler coordinates with the boundary conditions mimicking a uniformly accelerated mirror in Minkowski space. In the nonrelativistic limit, all these models in the comoving frame reduce to the familiar eigenvalue problem for the Schrödinger equation with a fixed floor in a linear gravitational potential, as expected. We find that the transition frequency between two energy levels of a bouncing Dirac particle is greater than the counterpart of a Klein–Gordon particle, while both are greater than their nonrelativistic limit. The different corrections to eigen-energies of particles of different nature are associated with the different behaviors of their wave functions around the mirror boundary.

From titania nanoparticles to decahedral anatase particles: Photocatalytic activity of TiO2/zeolite hybrids for VOCs oxidation

In this work, zeolite/TiO2 hybrid photocatalysts based on TiO2 particles of different nature for photooxidation of VOCs in air have been developed. TiO2 with different morphologies, namely, TiO2 nanoparticles (Ti-NP) and decahedral anatase particles (DAPs), have been synthetized and characterized. A commercial TiO2 (Ti-C) catalyst has been used as a reference. Titania has been incorporated on ZSM-5 by different techniques: incipient wetness impregnation, freeze-drying, or mechanical mixing from a TiO2 sol, DAPs, or commercial TiO2. The TiO2 and hybridized photocatalysts were characterized by SEM, TEM, XRD, UV–vis spectroscopy, N2 adsorption-desorption and electrophoretic migration. Moreover, the formaldehyde or trichloroethylene adsorption ability of the composites has been analysed. The photocatalytic performance for the HCHO or C2HCl3 photooxidation under UV-A irradiation and continuous air flow has been evaluated. TiO2 nanoparticles of 5 nm, DAPs of ca. 100 nm, and 1.0 μm clusters of TiO2 made of 15 nm mean particle size characterized the three types of TiO2. These characteristics are maintained in the zeolite/TiO2 composites. In spite of the lower BET area, DAPs presented the highest VOCs reaction rate comparing to the other TiO2. The incorporation of titanium oxide to the microporous material results in the improvement of the photocatalytic performance, regardless of the actual nature of the TiO2 particles. Nevertheless, a relationship between the particle size and the improvement of the photocatalytic performance can be established. Thus, the incorporation of TiO2-NP into the zeolitic material, lead to composites with around ten times more photoactivity that the single titania particles. This effect is less pronounced for larger TiO2 particles such as DAPs and less evident for TiO2 aggregates present in commercial material. TiO2 nanoparticles homogeneous distributed on the hierarchical material shows the highest VOCs photooxidation and CO2 formation rates of the series.

Speciation of actinides in groundwater samples collected near deep nuclear waste repositories

Actinide binding to colloidal particles of different nature was studied under oxic and anoxic conditions of an underground nuclear waste disposal site using successive micro- and ultrafiltration techniques. According to the actinide redox speciation, under oxic conditions they were present in high oxidation states except for plutonium, for which a significant part was found in the tetravalent state. In case of the anoxic conditions, the share of An (IV) was proportional to the total U(IV) concentration. This indicated formation of intrinsic U(IV) hydroxocolloids, which bound other actinides. Formation of the intrinsic actinide colloids was proven by the secondary ion mass spectrometry (SIMS) with the submicron resolution. In contrast, under the oxic conditions uranium and plutonium were sorbed by natural colloids (amorphous hydrous ferric oxide and Mn oxides).

The investigation of the structure and operation of a multi-channel cyclone, separating fine solid particles from an aggressive dispersed gas and vapour flow

A multi-channel cyclone is a new-generation cleaning device, which purifies a gas flow by removing fine dispersion solid particles of 2 μm and larger in diameter from it. An aggressive dispersed gas flow can be formed under various conditions, for example, in combustion and processing of various products such as drying of chemical compounds, etc., at high temperature and/or high humidity. Multi-channel cyclones of a new generation have a number of advantages over the most widely used equipment for separating the particulate matter from the air flow such as electrostatic and bag filters, which are rather expensive, difficult to maintain and to be used for separating sticky and moist particles from the aggressive gas flow. The paper examines wood and lignin solid particles of different nature and properties present in a gas-vapour flow. Their adhesion and cohesion, depending on the time of the multi-channel cyclone operation aimed at purifying a dusted gas-vapour flow at high gas-vapour temperature and humidity are investigated. The research is aimed at determining the optimal separation efficiency and the aerodynamic parameters of a multi-channel cyclone and their variation by creating an aggressive dispersed gas flow. It assesses the detrimental effect of the deposition of wood and lignin solid particles on its interior surfaces, their cohesion and adhesion and clogging the system. The efficiency of the cyclone's operation is investigated for the flow, moving at medium rates and containing solid particles of various sizes. The highest cyclone's efficiency is determined for its separation of medium- and small-size solid particles. The theoretical study of kinematic and dynamic gas flow viscosity and the calculation of its coefficients as well as the dew point temperature of the flow are performed and the relationships between them are determined. The obtained results are presented and some recommendations for improving the structure of a multi-channel cyclone for separating sticky and moist particles from a humid and hot gas flow are provided.

Field-flow fractionation of microparticles in a rotating coiled column for the preparative separation of sorption materials

It is demonstrated that field-flow fractionation using a rotating coiled column (RCC) can be used for the separation and purification of the polydisperse sorbents based on polystyrene–divinylbenzene. The behavior of the sorbent at different operating parameters of RCC was studied. The mobile phase composition, column rotation speed, and the initial flow rate of the mobile phase were selected, optimized for the isolation of a monodisperse fraction with the particle size 4.5 µm and the separation of particles 0.5–2 µm in size, particle fragments, and residues of sorbent synthesis. It is shown that a 15-mL analytical RCC ensures the efficient fractionation of 100 mg of the sorbent in one experiment taking less than one hour with the yield of the desired fraction greater than 95%. The perspectives for scaling up the fractionation in RCC are evaluated; the possibility of using the method for the preparative separation of particles of different nature is discussed.

Manipulations of Submicro-fibers of Culex Pipiens with the Help of Nano-tweezers with Shape Memory Effect into Vacuum Chamber of FIB

In recent years, a record small mechanical tools based on composites with shape memory effect (SME) were created [1-4]. Application of the technology of selective ion etching allowed for the creation of two-layer composite actuators and tools based on rapidly quenched nonmagnetic alloys with SME, such as Ti2NiCu [1]. These composite actuators can change their shape reversely and produce mechanical work using only “one-way” SME of the alloy [2]. Currently in the field of manipulation and manufacturing at the nanoscale, there is an urgent need to develop new functional materials in order to fill the gap between the dimensions of modern MEMS and real size of nano-objects to be manipulated. Recently the operation of nano-tweezers using layered composites based on alloy with SME driven by thermal actuation has been demonstrated [1-3]. The operation of the Ti2NiCu/Pt composite actuator driven by heating was demonstrated, with an overall volume of the actuator of less than 1 μm3 and thickness of active layer of the T2NiCu alloy being down to 70 nm [1]. These achievements of nanotechnology can be used certainly in various branches of biology. Developed technique allow to hold, move and manipulate of animate or inanimate objects of submicron and nanometer sizes, for example, carbon nanotubes, graphene sheets, bacteria, viruses, biological particles of different nature. The purpose of this paper is description of experiments on preparation of insect’s fibers of submicron sizes into a vacuum chamber of FIB.

RESEARCH INTO THE CLEANING EFFICIENCY OF 300 M3/H MAINTAINED BY THE SPIRAL MULTI-CHANNEL CYCLONE IN THE PROCESS OF REMOVING SOLID PARTICLES OF <20 ΜM / 300 M3/H NAŠUMO SPIRALINIO DAUGIAKANALIO CIKLONO VALYMO EFEKTYVUMO TYRIMAS, ŠALINANT < 20 ΜM KIETĄSIAS

Tests on the cleaning efficiency of an experimental spiral cyclone have been conducted to determine the removal efficiency of the solid particles the dispersion of which makes <20 µm in the streamlined multi-channel cyclone. The introduced device is adapted to removing ultrafine particulate matter from contaminated air (gas) flow. A multi-channel cyclone with spiral casing has been designed at the Department of Environmental Protection (DEP) of Vilnius Gediminas Technical University. Experimental studies have disclosed that air (gas) flow cleaning efficiency of the spiral multi-cyclone (capacity 300 m3) depend on the internal structure of the device, i.e. on the number of channels and air (gas) flow distribution ratio of transit and peripheral channels. Also, the treatment efficiency of the applied equipment has been evaluated removing solid particles of different nature. AFA-VP-20 filters have been employed for conducting experimental tests. The obtained results have disclosed that solid granite particles – 95.1%, glass – 91.4% and wood – 92.2% are removed most effectively. Eksperimentiniai spiralinio ciklono valymo efektyvumo tyrimai atliekami siekiant nustatyti kietųjų dalelių, kurių dispersija x < 20 μm, pašalinimo efektyvumą patobulintame daugiakanaliame ciklone. Minėtas įrenginys pritaikytas itin smulkioms kietosioms dalelėms iš užteršto oro (dujų) srauto pašalinti. Daugiakanalis ciklonas, turintis spiralinį korpusą, sukurtas Vilniaus Gedimino technikos universiteto (VGTU) Aplinkos apsaugos katedroje (AAK). Eksperimentinių tyrimų metu nustatytas spiralinio daugiakanalio ciklono (našumas 300 m3/h) oro (dujų) srauto valymo efektyvumas priklausomai nuo vidinės įrenginio konstrukcijos, t. y. nuo kanalų skaičiaus ir oro (dujų) srauto pasiskirstymo į tranzitinį ir periferinį kanalus santykio. Taip pat įvertintas įrenginio valymo efektyvumas, šalinant skirtingos prigimties kietąsias daleles. Eksperimentiniams bandymams atlikti naudoti AFA-VP-20 filtrai. Remiantis bandymų rezultatais, nustatyta, kad efektyviausiai šalinamos granito kietosios dalelės – 95,1 %, stiklas – 91,4 %, mediena – 92,2 %.

Interaction of waves with a birefringent medium moving with acceleration

Recent experiments demonstrated that the energy of a neutron traversing an accelerated sample of a refractive medium changes. Later, it was realized that such an accelerated-medium effect (AME) is quite a general phenomenon characteristic of waves and particles of different nature. This paper discusses some special features of the effect for a birefringent medium. In this case, AME shows quite new features. In neutron optics, where birefringence is due to the spin dependence of the refractive index, AME results in a nonstationary state with a precessing spin. In the case of the propagation of a two-flavor neutrino through an accelerated layer of matter, AME affects substantially the ensuing evolution of a neutrino flavor state as it propagates through a free space.

Attenuation of radioactive releases from NPP under accident conditions: An experimental research on risk-dominant scenarios

Accident scenarios in which a nuclear power plant (NPP) containment is by-passed, may become a significant contribution to the NPP risk. The reason is the direct access to the environment that any radioactive material escaping from a degrading core would have. This is the case of steam generator tube rupture (SGTR) severe accident sequences in pressurized water reactors (PWRs), in which tube breaches in the steam generator communicate the primary system of the nuclear reactor and the environment.This paper presents the major results of an experimental investigation aimed to assess and characterize the mitigation of radioactive releases when flowing through the secondary side of a steam generator during SGTR severe accident sequences. A set of experiments performed in a mock-up tube bundle scaled from a real steam generator has demonstrated that particles are significantly retained in the region around the breach, even in the total absence of water. The tests explored the anticipated conditions in the scenario: gas jet injection, micron particles of different nature (dense spheres vs. aggregates) and tube breach types (guillotine vs. fish-mouth). The main variable affecting retention is the particle nature. The collection efficiency reached 75–95% in the case of dense spheres. The influence of natural aerosol mechanisms like inertial impaction, turbulent deposition, resuspension and fragmentation are discussed in the paper.

Uranium (VI) in natural waters: Study of occurrence forms

A comparative study of U(VI) occurrence forms in natural waters has been conducted on the basis of experimental determination of the faction of U(VI) soluble and colloidal forms and the calculation of the specified forms by using the known stability constants. It was shown that the forms of U(VI) radionuclide in aqueous media could considerably change depending on the concentration of U(VI), carbonate ions, and suspended particles of different nature. It has been found out that uranium U(VI) at the level of its typical concentrations (several micrograms and less) occurs in natural waters in soluble different-metal and carbonate forms.

Creation of two vortex-entangled beams in a vortex-beam collision with a plane wave

Physics of photons and electrons carrying orbital angular momentum (OAM) is an exciting field of research in quantum optics and electron microscopy. Usually, one considers propagation of these vortex beams in a medium or external fields and their absorption or scattering on fixed targets. Here we consider instead a beam-beam collision. We show that elastic scattering of a Bessel vortex beam with a counterpropagating plane wave naturally leads to two vortex-entangled outgoing beams. The vortex entanglement implies that the two final particles are entangled not only in their orbital helicities but also in opening angles of their momentum cones. Our results are driven by kinematics of vortex-beam scattering and apply to particle pairs of any nature: e-gamma, e^+e^-, ep, etc. This collisional vortex entanglement can be used to create pairs of OAM-entangled particles of different nature, and to transfer a phase vortex, for example, from low-energy electrons to high-energy protons.

On the lattice Boltzmann method for phonon transport

The lattice Boltzmann method is a discrete representation of the Boltzmann transport equation that has been employed for modeling transport of particles of different nature. In the present work, we describe the lattice Boltzmann methodology and implementation techniques for the phonon transport modeling in crystalline materials. We show that some phonon physical properties, e.g., mean free path and group velocity, should be corrected to their effective values for one- and two-dimensional simulations, if one uses the isotropic approximation. We find that use of the D2Q9 lattice for phonon transport leads to erroneous results in transient ballistic simulations, and the D2Q7 lattice should be employed for two-dimensional simulations. Furthermore, we show that at the ballistic regime, the effect of direction discretization becomes apparent in two dimensions, regardless of the lattice used. Numerical methodology, lattice structure, and implementation of initial and different boundary conditions for the D2Q7 lattice are discussed in detail.

The rigidity dependence of characteristic decay time and mean free path in SCR events

Combination of data on declined intensities of particles of different nature (e, p, and α) into a single dependence of characteristic decline time τ on particle rigidity in a wide range of R reveals the diversity of forms of τ(R) in different events: regular increase, decrease, and independence of R, as well as the presence in some events of maxima and minima. The problem of studying τ(R) has something in common with long standing problem of the rigidity dependence of mean free path λ(R). The considered set of forms of τ(R) allows one to conclude that at present there is no uniform dependence τ(R), as well as λ(R), and, therefore, no their common model interpretation in a wide range of rigidities exists.