bluuebunny/crossref_metadata_2025 huggingface dataset:
Pilot Evaluation of Programmatic Elements for First-Generation and
Historically Marginalized Doctoral Students and their Families
Authors: Walsh Bridget A. , Mitchell Sarah , Kyeremeh Addai Emmanuel , Aguirre Matthew , Hambrick Keira
Published: May 2024

While research demonstrates that family support is
essential for doctoral students, research detailing institutional efforts to involve
families is limited. We developed the GAIN Scholars program, consisting of two
3-week-long boot camps for incoming first-generation and historically marginalized
doctoral students. Quantitative data were collected from 38 doctoral students in the
GAIN Scholars program (n = 22) and the control (n = 16). One key component of this
program was family support for doctoral students. Family members (n = 15) were invited
to the opening ceremony, a day of programming, and online activities. Pre- and post-test
measures indicate participants had a greater ability to identify resources, a greater
ability to identify important life values as they impact resource identification
decision-making, and a greater ability to identify complex environments and means for
situational adaption, suggesting the program increased doctoral students’ skills related
to navigating environments, resources, and decision-making. Qualitative findings from
doctoral students and their family members offered praise for the program and
appreciation for the support opportunities. These results indicate that programs such as
this—that foster connections among graduate students and their families—can be
potentially beneficial in helping graduate students not only stay but thrive in their
programs.
SPECTRAL-ACOUSTIC MONITORING OF DAMAGE IN POLYCRYSTALLINE MATERIALS BASED ON A SIMULATION-MECHANICAL MODEL
Authors:   Nizhny Novgorod State Technical University, KHLYBOV A.A. , UGLOV A.L. , RYABOV D.A.
Published: May 2024

In this study, a modified simulation-mechanical model is developed for dispersed damage accumulation in a polycrystalline material based on continuum damage mechanics and physical mesomechanics. The main damaging factors are assumed to be the field of dispersed microcracks in the material and the field of internal stresses arising primarily from linear structural defects. The statistical limit state criterion of a material following from the proposed model is consistent with the known information about the failure conditions of brittle and ductile structural materials. The possible application of the limit state criterion is discussed for typical cases of failure and transition from elastic to elastic-plastic deformation of polycrystalline structural materials. The proposed spectral-acoustic method for material damage assessment is used to analyze elastic pulse propagation in the simulated medium. The existence of some acoustic effects in the damaged medium is substantiated, which can be useful for the instrumental assessment of material damage at any time during loading of a sample or service of a structural element. It is shown that the spectral-acoustic method can provide a basis for a technique of measuring the damage parameters included in the proposed model. Available experimental data confirm the correctness of the damage assessment approach for structural materials. Further experimental studies will develop methods for express monitoring of dispersed damage in metal structures subjected to thermomechanical loads.
EFFECT OF ADDING GRAPHENE OXIDE NANOPLATELETS ON THE ARALDITE ADHESIVE FRACTURE STRENGTH UNDER MIXED-MODE I/II LOADING
Authors:   University of Tabriz, BOLGHAND YA. , CHAKHERLOU T.N. , BIGLARI H.
Published: May 2024

In the present paper, the effect of adding graphene on the fracture strength of the Araldite adhesive was studied. Experimental specimens were made of PMMA and then were bonded using a thin adhesive layer. Different loading modes were created by using the modified Arcan fixture. The effect of adding graphene to the adhesive layer was studied at four different weight ratios of graphene, including 0.00, 0.25, 0.50, and 1.00%. The results derived suggest that the experimental specimens with 0.5 wt % graphene have the highest fracture force. For specimens with the same amount of graphene, the highest fracture force was obtained under the mode II loading condition. The experimental results were compared with the results of the finite element model. The fracture behavior of an adhesive layer was modeled using the cohesive zone model. The maximum nominal stress criterion and the quadratic power law criterion were used for the crack initiation and propagation in the adhesive layer, respectively. The comparison between the numerical and experimental results shows overall good agreement.
TRANSFORMATION OF A LONGITUDINAL ELASTIC WAVE INTO A POCHHAMMER WAVE
Authors:   Institute of Strength Physics and Materials Science SB RAS, KRIVOSHEINA M.N. , TUCH E.V.
Published: May 2024

The finite element method in a dynamic formulation was used to characterize the propagation of longitudinal elastic waves in cylindrical plates and Pochhammer waves in rods. It was shown that in compact bodies first only one longitudinal wave propagates until unloading waves from the side surfaces begin to interact, and then two types of longitudinal elastic waves propagate simultaneously. In rods, a longitudinal elastic wave propagates at the initial stage. Over time, the influence of unloading from the side surfaces of the rod leads to the simultaneous propagation of two types of elastic waves: a longitudinal elastic wave and a Pochhammer wave. Using aluminum as an example, the range of geometric parameters was determined for nearly compact bodies, whose elastic properties cannot be evaluated by ultrasonic methods.
FRACTURE OF 30CRMNSIA STEEL UNDER MIXED LOADING MODES
Authors:   Baikov Institute of Metallurgy and Materials Science RAS, BOTVINA L.R. , BELETSKY E.N. , TYUTIN M.R. , DEMINA YU.A. , SINEV I.O. , BOLOTNIKOV A.I. ,   Bauman Moscow State Technical University
Published: May 2024

Tests were conducted on notched specimens made of 30CrMnSiA steel in loading mode I with the fracture surface perpendicular to the loading direction (90°) and in mode II with shear angles of 45° and 15°. Shear loading was performed using Richard’s grips that allow for a transition from pure mode I to pure mode II by varying the angle of the notch in relation to the direction of the tensile load. Using digital image correlation, the acoustic emission (AE) signals and the strain field were measured during testing, and the damage and microhardness of the polished side face of the specimens were evaluated after failure. The macro- and microscopic research of fracture surfaces revealed that an increase in the shear component during tension leads to changes in the mechanical and acoustic properties and the ductile-to-brittle-transition temperature. This is evidenced by a change of the fracture surface morphology from ductile to brittle at 45° loading direction, accompanied by a change in all estimated acoustic parameters (the total number of events, the angular coefficient of the cumulative distribution of acoustic signals by amplitude-b-value, and the activity of AE signals). An increase in the shear component also leads to a nonlinear dependence of the damage parameters on the load application angle, such as the relative microcrack area S*, average microcrack length lav, and microcrack inclination angle with respect to the loading axis, which correlate with the change in the principal strains estimated by digital image correlation.
COUPLED POROMECHANICS AND ADSORPTION IN MULTIPLE-POROSITY SOLIDS
Authors:   The Pennsylvania State University, ZHANG W. , MEHRABIAN A.
Published: May 2024

This paper presents a general constitutive model to describe the coupling among bulk solid stress, pore fluid pressure, and adsorption in a fluid-saturated multiple-porosity elastic solid. The general case of N coexisting porosities is considered. Each porosity system may contain fluid in the free or adsorbed phase, as well as in both phases. Thus, the utility of the developed constitutive relations extends to materials with complex pore structures, which may involve several scales of pore size. These relations are obtained from the thermodynamic free energy density function for deformation of the porous solid frame while incorporating the surface energy stored at the interface between the pore fluid and solid phase. A number of previously published models for coupled adsorption and poroelasticity in microporous and mesoporous materials are examined as special cases. Possible means of estimating the constitutive model parameters are discussed.
QUANTITATIVE CHARACTERIZATION OF GRAIN BOUNDARIES IN ULTRAFINE-GRAINED AUSTENITIC STAINLESS STEEL BY CLUSTER ANALYSIS
Authors:   Institute of Strength Physics and Materials Science SB RAS, KUZNETSOV P.V. , STOLBOVSKY A.V. , BELYAEVA I.V. ,   M.N. Mikheev Institute of Metal Physics UrB RAS
Published: May 2024

A method is proposed for analyzing the relative energy distributions of boundaries in ultrafine-grained materials measured by grain boundary grooving using scanning tunneling microscopy. The energy distribution of boundaries in a grain boundary ensemble is considered as a superposition of individual distributions (populations), which can be identified by cluster analysis based on statistical criteria and each of which has its own value of average energy, dispersion, and share in the overall distribution. The energy distributions of grain boundaries are analyzed for 12Cr15Mn9NiCu steel with a coarse-grained structure in the as-received state and with an ultrafine-grained structure produced by hot helical rolling and subsequent cold rolling. It is shown that the number of boundary populations and their main characteristics revealed by cluster analysis depend on the steel structure. The results of cluster analysis of experimental distributions are compared with the EBSD measurement data on grain boundary misorientation distributions. Discrepancy between the cluster analysis results for the energy and misorientation distributions of boundaries is discussed taking into account the difference in the nature of the data obtained.
NONADIABATICALLY DRIVEN SUBCRITICAL CRACK NUCLEATION IN SOLIDS
Authors:   Institute of Strength Physics and Materials Science SB RAS, KHON YU.A.
Published: May 2024

This paper discusses a subcritical crack initiation mechanism in a brittle solid within a real range of applied stress. A medium deformed by uniaxial tension is considered as an open nonequilibrium system of nuclei and electrons. Structural relaxation of the medium begins with the excitation of dynamic displacements during nonadiabatic Landau-Zener transitions. Dynamic displacements induce the instability of the medium to the longitudinal displacement wave. The kinetics of structural relaxation is described by two nonlinear parabolic kinetic equations for dynamic order parameters. Conditions are derived for the existence of localized solutions (autosolitons). The excitation of autosolitons leads to a local elongation and cross-sectional reduction of the specimen. The resulting neck is a subcritical crack.
AN INDENTATION STUDY OF THE TEMPERATURE-DEPENDENT PROPERTIES OF MODIFIED POLYURETHANES
Authors:   Ishlinsky Institute for Problems in Mechanics RAS, TORSKAYA E.V. , YAKOVENKO A.A. , SHKALEY I.V. , SVISTKOV A.L. ,   Institute of Continuous Media Mechanics UrB RAS
Published: May 2024

Carbon nanoadditives are widely used as modifiers for various materials. An important issue is the effect of modification on the material properties, including their sensitivity to temperature changes. Here we study the variable temperature indentation of polyurethanes produced by solution technology and modified with fullerenes and carbon nanotubes. It is found that the addition of modifiers not only changes the mechanical and rheological properties of the material, but also makes these properties more temperature dependent. Based on solving an axisymmetric contact problem of the constant velocity indentation of a viscoelastic halfspace, a method is developed for determining material properties from experimental indentation curves obtained at different velocities. The properties of the original and modified polyurethanes are determined at three fixed temperatures. Modifiers produce different effects: nanotubes increase rigidity, while fullerenes reduce it. The effect of ion plasma surface treatment, which leads to the formation of a hard carbonized nanolayer, on the results of indentation at different temperatures is investigated.
HIGH-STRENGTH STATE AND STRENGTHENING MECHANISMS OF ULTRAFINE-GRAINED TITANIUM
Authors:   Ufa University of Science and Technology, USMANOV E.I. , REZYAPOVA L.R. , VALIEV R.Z.
Published: May 2024

This paper discusses the formation of an ultrafine-grained (UFG) structure and nanosized second phase precipitates in commercially pure Grade 4 titanium subjected to severe plastic deformation by torsion at room temperature and subsequent heat treatment. It was found that the combined treatment of Grade 4 titanium produces very high tensile strength (σB ≈ 1500 MPa), which significantly exceeds the previously obtained values for this material. Analysis of the strengthening mechanisms showed that the superstrength of commercially pure titanium is due to several factors: formation of a UFG structure, dispersion strengthening from nanosized second phase particles, high dislocation density, and grain boundary segregation. The contribution of these strengthening mechanisms is evaluated and compared with experimental data.
A STUDY OF DEFORMATION AND FRACTURE OF THE EUTECTIC IN AN ADDITIVELY MANUFACTURED AL-SI COMPOSITE ALLOY
Authors:   Institute of Strength Physics and Materials Science SB RAS, ZEMLYANOV A.V. , GATIYATULLINA D.D. , UTYAGANOVA V.R. , SHAMARIN N.N. , NIKONOV S.YU. , ROMANOVA V.A. , BALOKHONOV R.R.
Published: May 2024

The structure of AlSi12 alloy fabricated by wire-feed electron beam additive manufacturing was studied experimentally. A numerical study was performed to examine the thermomechanical behavior and fracture of a eutectic fragment at the scale of several microns. Boundary dynamic problems were solved under plane strain conditions. The composite structure of the eutectic system consisting of an aluminum matrix and silicon particles was taken into account explicitly in the calculations. Isotropic models of the thermoelastic-plastic matrix and elastic-brittle particles were implemented in ABAQUS/Explicit. Strains in the composite were calculated both with and without allowance for residual stresses caused by cooling after fabrication. It was shown that after the cooling of the eutectic, silicon particles are compressed, and the aluminum matrix is under both bulk compressive and tensile as well as under pure shear stresses. It was found that residual stresses play a negative role at the stages of intense deformation of the composite. The fracture strain of the eutectic strongly depends on the yield stress of the matrix, while the ultimate fracture stress varies little. Favorable morphology of silicon particles was determined which prevents early fracture of the eutectic.
ANALYSIS OF THE PROPERTIES OF A NONLINEAR SHEAR FLOW MODEL OF THIXOTROPIC MEDIA TAKING INTO ACCOUNT THE MUTUAL INFLUENCE OF STRUCTURAL EVOLUTION AND DEFORMATION PROCESS
Authors:   Institute of Mechanics, Lomonosov Moscow State University, KHOKHLOV A.V. , GULIN V.V. ,   Ammosov North-Eastern Federal University,   Moscow Center of Fundamental and Applied Mathematics
Published: May 2024

A systematic analytical study was conducted on the mathematical properties of the previously proposed prototype of a nonlinear Maxwell-type constitutive equation for describing the shear flow of thixotropic media (viscous liquid polymers, viscoelastic melts, concentrated solutions, pastes, emulsions), which takes into account the mutual influence of the deformation process and structural evolution (the kinetics of formation and breaking of intermolecular bonds) on viscosity and shear modulus and the effect of the deformation process on this kinetics. In the uniaxial case, the constitutive equation is governed by a nondecreasing material function and six positive parameters. The equation is reduced to a system of two nonlinear autonomous differential equations for the stress and the structuredness parameter. It is proved that the equilibrium position of this system is unique. The dependences of the position coordinates on all material parameters and on the shear rate for an arbitrary nondecreasing material function are investigated in general form, and all the dependences are proved to be monotonic. Equations for the flow and viscosity curves are derived and investigated. It is proved that the model leads to an increasing dependence of the equilibrium stress on the shear rate and to a decreasing apparent viscosity curve, which reflect the typical properties of the experimental flow curves of pseudoplastic media. Using six arbitrary material parameters and a material function that control the model, we analytically study the phase portrait of the nonlinear system of two differential equations, to which the model is reduced, for dimensionless stress and the degree of structuredness in the vicinity of its only equilibrium position. It is proved that the equilibrium position is always stable and can be of three kinds only: a stable node, a degenerate node, or a stable focus. Criteria for each kind are found in the form of explicit constraints on the material function, model parameters, and shear rate. The existence of a stable focus indicates the nonmonotonicity of the system solutions and the existence of deformation modes with (damped) fluctuations of stress and structuredness when stationary values are reached. The influence of the material parameters and material function on the type of equilibrium point and on the behavior of the model integral curves is analyzed.
COMPARATIVE ANALYSIS OF WELD MICROSTRUCTURE IN TI-6AL-4V SAMPLES PRODUCED BY ROLLING AND WIRE-FEED ELECTRON BEAM ADDITIVE MANUFACTURING
Authors:   Institute of Strength Physics and Materials Science SB RAS, PANIN A.V. , KAZACHENOK M.S. , KRUKOVSKY K.V. , KAZANTSEVA L.A. , MARTYNOV S.A.
Published: May 2024

The microstructure and phase composition of electron beam welded Ti-6Al-4V titanium alloy were studied by optical and scanning electron microscopy, backscattered electron diffraction, and X-ray diffraction analysis. Deep-penetration electron beam welds were made in single pass on rectangular Ti-6Al-4V samples obtained by rolling and wire-feed electron beam additive manufacturing. It was found that the weld width in 3D printed Ti-6Al-4V samples is greater than in the rolled material. The influence of the gas vapor channel on the size, shape and structure of primary β-grains formed in the fusion zone was shown. The variation of the penetration coefficient, volume fraction of the residual β phase, and residual stresses along the weld length was studied for Ti-6Al-4V samples obtained by both rolling and 3D printing.
EFFECT OF LOCAL STRESSES ON THE FRACTURE OF METALLIC MATERIALS WITH DIFFERENT LATTICES UNDER SINGLE LOADS
Authors:   Togliatti State University, KLEVTSOV G.V. , VALIEV R.Z. ,   Institute for Physics of Advanced Materials, Ufa University of Science and Technology, KLEVTSOVA N.A.
Published: May 2024

The study discusses the effect of the local stress field at the crack tip on the fracture behavior of coarseand ultrafine-grained materials with bcc, fcc, and hcp lattices under single loads (impact and static). The local stresses at the crack tip under impact and static loading were assessed by the hmax/t ratio, where hmax is the maximum depth of the plastic zone under the fracture surface and t is the specimen thickness. The depth of plastic zones under the fracture surface was determined using layer-by-layer etching of the surface followed by X-ray diffraction analysis. The study results showed that it is not always possible to establish an unambiguous relationship between the fracture mechanisms of metallic materials and the local stress field at the crack tip. Nevertheless, some particular relationships were established: (i) the cleavage, quasi-cleavage, or intergranular brittle fracture of materials, regardless of lattice type, is indicative of plane strain deformation, (ii) under plane stress, all materials, regardless of lattice type, exhibit ductile fracture with micropitting, and (iii) in the transition from plane strain to plane stress, most fcc materials fracture by a mixed mechanism.
CREEP RESISTANCE AND STRUCTURE OF 10% CR-3% СО-2% W-0.29% CU-0.17% RE STEEL WITH LOW NITROGEN AND HIGH BORON CONTENTS USED IN UNIT COMPONENTS FOR COAL POWER PLANTS
Authors:   Belgorod State University, FEDOSEEVA A.E.
Published: May 2024

The creep resistance and structure of 10% Cr-3% Co-2% W-0.29% Cu-0.17% Re steel with 0.1% carbon, low nitrogen content, and high boron content were investigated in a long-term fracture strength test at 650°C under loads from 200 to 100 MPa applied in increments of 20 MPa. For comparison, 9% Cr steel with 0.1% carbon, 0.05% nitrogen, and 0.005% boron was studied. The steels were subjected to preliminary heat treatment including normalization at 1050°C for 1 hour, tempering at 750-770°C for 3 hours, and cooling in air. The structures of both heat-treated steels exhibited martensite laths with boundaries pinned by М23С6 carbides, and the rearrangement of dislocations was retarded by MX particles. A significant difference between 10% Cr steel and 9% Cr steel was the presence of fine М23С6 carbide particles characterized by orientational relationships with the ferrite matrix and MX carbonitrides, whose volume fraction was 6 times lower. Short-term tensile tests at room temperature showed no differences between the steels, while the long-term tensile strength of 10% Cr steel was 13% higher compared to 9% Cr steel. The creep deformation mechanism of the steels was also different. Structural analysis of 10% Cr steel after creep tests revealed no substantial changes in its lath structure: the lath width increased by only 58% and the dislocation density was reduced by a factor of 2. Comparison with 9% Cr steel showed that the good structural stability of 10% Cr steel during creep is caused by the high coarsening resistance of second-phase particles, whose coarsening rate is 1-2 orders of magnitude lower than that in 9% Cr steel.
EXPERIMENTAL AND NUMERICAL INVESTIGATION OF MESOSCALE DEFORMATION-INDUCED SURFACE ROUGHENING IN POLYCRYSTALLINE METALS AND ALLOYS (REVIEW)
Authors:   Institute of Strength Physics and Materials Science SB RAS, EMELYANOVA E.S. , ZINOVIEVA O.S. , ROMANOVA V.A. , BALOKHONOV R.R. , PISAREV M.
Published: May 2024

The paper provides a review of experimental and numerical studies of deformation-induced free surface roughening in loaded metals and alloys. Various parameters for assessing strain-induced surface roughness, factors influencing the roughness characteristics, and models describing surface roughening in polycrystalline alloys are considered.
DEVELOPMENT OF AN EXPERIMENTAL TECHNIQUE FOR THE ESTIMATION OF FATIGUE CRACK EVOLUTION IN TITANIUM ALLOYS BASED ON AN ENERGY APPROACH
Authors:   Institute of Continuous Media Mechanics UrB RAS, IZIUMOVA A.YU. , VSHIVKOV A.N. , PLEKHOV O.A.
Published: May 2024

This paper presents an experimental study of energy dissipation caused by fatigue crack growth in titanium alloys Ti Grade 2, Ti-1.1Al-0.9Mn, and Ti-4.6Al-1.77V using an original heat flux measurement technique. It is shown that significant structural changes occur in the material under plastic deformation, leading to internal energy evolution. As is known, a large part of the deformation energy is dissipated as heat. The developed experimental technique allows high-accuracy measurements of the heat flux caused by plastic zone development at the crack tip directly in the fatigue experiment. Simultaneous measurements of the crack length and displacements in the stress concentration zone allow estimating the energy balance of the tested specimens. Analysis of the obtained data confirms that the stored strain energy reflecting the structural state of the material can be used as a fracture criterion. A kinetic equation is derived for predicting the fatigue crack growth rate in the Paris regime by energy dissipation rate on the basis of heat flux data.
COMBINATION EFFECT OF TRANSITION METAL IMPURITIES ON THE OXYGEN VACANCY FORMATION ENERGETICS IN TIO2
Authors:   Institute of Strength Physics and Materials Science SB RAS, BAKULIN A.V. , CHUMAKOVA L.S. , KASPARYAN S.O. ,   National Research Tomsk State University, KULKOVA S.E.
Published: May 2024

The combination effect of substitutional impurities of group IVB-VIB transition metals on the oxygen vacancy formation energy in titania with rutile structure was studied by the projector augmented-wave method within the density functional theory. The pair interaction energy of impurity atoms was estimated depending on the interatomic distance. It was shown that the interaction in the Zr + Zr, Hf+Hf and Nb + Ta pairs leads to the energy preference of their orientation along the (100) direction at a distance of the lattice parameter a. The Mo + Mo and Nb + Mo pairs prefer to orient along the [001] direction at a distance of the lattice parameter c. If the impurity atoms are farther than the third neighbors, then their interaction can be neglected. It was found that the change in the formation energy of the oxygen vacancy due to doping with several impurities can be estimated as the sum of the energy changes due to single impurity divided by a coefficient whose value depends on the mutual arrangement of the impurity atoms.
THERMAL CONDUCTIVITY, RHEOLOGY AND ELECTRICAL CONDUCTIVITY OF WATER AND ETHYLENE GLYCOL BASED NANOFLUIDS WITH COPPER AND ALUMINUM PARTICLES
Authors:   Novosibirsk State University of Architecture and Civil Engineering, RUDYAK V.YA. ,   Kutateladze Institute of Thermophysics SB RAS, PRYAZHNIKOV M.I. , MINAKOV A.V. ,   Siberian Federal University
Published: May 2024

Nanoparticles are mesoobjects that occupy an intermediate position in size between ordinary molecules and macroscopic particles. Suspensions with nanoparticles, called nanofluids, are also specific mesoscopic suspensions. Today it is known that their thermophysical and mechanical properties are not described by classical theories. The unusual properties of these dispersed fluids make them extremely popular in a wide variety of applications. However, successful use of nanofluids involves the prediction of their properties, which in turn requires systematic studies. This paper presents an experimental study on the thermophysical properties of water and ethylene glycol based nanofluids with aluminum and copper particles. The thermal conductivity, rheology and electrical conductivity of nanofluids were systematically studied. The weight concentration of nanoparticles varied from 2.5 to 20%. It was shown that the thermal conductivity of these nanofluids significantly exceeds that of nanofluids with oxide particles. Its higher values are determined by the size of the nanoparticles and the thermal conductivity of the base fluid. The nanofluids studied are either pseudoplastic or viscoplastic. Their rheology is determined by the concentration and size of nanoparticles. The smaller the size of nanoparticles and the higher their concentration, the more likely the change in rheology is. Correlation curves were constructed for the rheological parameters of nanofluids versus the concentration and size of nanoparticles. It was found that the electrical conductivity of nanofluids increases almost linearly with increasing nanoparticle concentration and strongly depends on the nanoparticle size. The electrical conductivity mechanisms of nanofluids were discussed. The speed of sound in a nanofluid and its dependence on particle size were measured.
CHANGES IN THE STRUCTURAL-PHASE STATE AND DISLOCATION DENSITY OF TI49.8NI502 ALLOY DEPENDING ON THE ISOCHRONOUS ANNEALING TEMPERATURE AFTER SEVERE PLASTIC DEFORMATION BY ABC PRESSING AT 573 K
Authors:   Institute of Strength Physics and Materials Science SB RAS, MIRONOV YU.P. , LOTKOV A.I. , GRISHKOV V.N. , LAPTEV R.S. , GUSARENKO A.A. , BARMINA E.G.
Published: May 2024

X-ray diffraction studies were conducted to examine changes in the structural-phase state and dislocation density of Ti498Ni50.2 alloy depending on the isochronous annealing temperature after severe plastic deformation by abc pressing at 573 K. The total true strain achieved in the alloy samples during abc pressing was e = 9.55. Isochronous annealing was carried out for 1 hour at 573, 673, 773, 873 and 973 K. Room-temperature analysis of all studied samples revealed the coexistence of R and B19' phases, whose relative fractions varied with annealing temperature. The high-temperature B2 phase was not detected. It was found that the most rapid decrease in the dislocation density, which was measured at 393 K (in the B2 state), occurs after annealing the samples at 673 and 773 K. After annealing at 773 K, the dislocation density reaches a minimum, and its value decreases by more than an order of magnitude compared to the value immediately after abc pressing. In the same temperature range there is a significant decrease in the root-mean-square B2 lattice microdistortions (e2)1/2 and a slight increase in the average size of coherent scattering regions. After abc pressing and after isochronous annealing, the main contribution to the physical peak broadening is made by the B2 lattice microdistortions, while the contribution from coherent scattering regions is insignificant. The obtained results show that intense recrystallization in Ti49 8Ni50.2 alloy after abc pressing at 573 K begins at T > 773 K.
DIFFERENT-SCALE HETEROGENEITIES IN SEGMENTS OF SEISMOGENIC FAULTS AND THEIR INFLUENCE ON SLIP MODES
Authors:   Institute of the Earth’s Crust SB RAS, RUZHICH V.V. , KOCHARYAN G.G. ,   Sadovsky Institute of Geosphere Dynamics RAS, OSTAPCHUK A.A. , SHILKO E.V. ,   Institute of Strength Physics and Materials Science SB RAS
Published: May 2024

The paper presents some multidisciplinary research results on the structure of slip surfaces in segmented sections of tectonic faults in the Baikal region and Mongolia. The properties of subsurface (modern) and deep slip planes that came to the earth’s surface as a result of many-kilometer denudation in the upper part of the earth’s crust are studied at different levels-from macroscale to nanocrystals. Other types of heterogeneities characterizing the structure of fault slip zones are also considered. The presented data indicate a heterogeneous structure of tectonic faults. Their slip zones show both low friction in sections where strong mineral phases are replaced by weak minerals, and potentially unstable patches with high frictional resistance. The results obtained in a comprehensive study of geological conditions, under which different-scale heterogeneities emerge in exhumed fault segments, should be taken into account when developing rock mass models suitable for numerical simulation of earthquake preparation processes at the micro-, mesoand macroscales.
IDENTIFICATION OF THE SPALLATION PROPERTIES AND SPALLATION THRESHOLD OF HETEROGENEOUS MATERIALS IN DYNAMIC PROCESSES
Authors:   Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, KRAUS A.E. , BUZYURKIN A.E. , SHABALIN I.I. , KRAUS E.I.
Published: May 2024

Shock wave loading of heterogeneous materials was numerically investigated using three models: a homogeneous alloy model with experimental parameters, an additive approximation model with parameters calculated from the constants and concentrations of the components, and a discrete numerical model constructed based on a random concentration distribution of components over the sample volume. The verification of the computational schemes was done by calculating the shock wave loading of homogeneous materials. Hugoniot curves were plotted and compared with experimental data to show a less than 5% deviation of the numerical results. A series of numerical simulations of spall fracture in homogeneous plates revealed that the velocity profile of the free surface as a result of spall fracture corresponds to the experimental profile. A relationship was derived to determine the spallation threshold for a heterogeneous medium based on the fracture parameters of its homogeneous components. The found homogeneous material parameters were used to simulate the shock wave loading of plates made of titanium nickelide and tungsten carbide/cobalt cermet constructed with heterogeneous models. It was shown that the heterogeneous models can be effectively applied to problems of shock wave loading with spall fracture, and the deviation between the calculated free surface velocity of a heterogeneous plate and the experimental data does not exceed 10%.
A fiscalização e a operação de trânsito: perspectivas para o direito ao trânsito seguro
Authors: Chaves Gustavo Vinicius Delmondes
Published: May 2024

O presente artigo versa sobre a importância da fiscalização e da operação de trânsito como instrumentos para viabilizar a segurança no trânsito. Nele, aborda-se a questão do sustentáculo ou tripé do trânsito seguro (educação, engenharia e esforço legal) pode contribuir para a execução de ações em cada uma das áreas desse tripé por intermédio da operação e da fiscalização de trânsito.  Há a discussão e o apontamento de como podem ser efetivadas as interações entre essas ferramentas e as áreas do tripé da segurança no trânsito, além de se tratar a abrangência do direito à segurança viária e as medidas a serem tomadas para sua real efetivação. Constatou-se que a fiscalização e a operação de trânsito são meios que podem colaborar para o desenvolvimento da educação, engenharia e esforço legal, consolidando o direito ao trânsito seguro.
Hanseníase: um levantamento de casos no Meio Oeste de Santa Catarina
Authors: Agnoleto Bruna Barbieri , Souza Gabriel Oliveira , Silva Amanda Lavina de Souza da , Zanardo Bruno Vitiritto Ferreira , Gregório Elizama de , Ogoshi Rosana Claudio Silva , Vanz Felipe , Somensi Líncon Bordignon
Published: May 2024

A hanseníase é uma doença infectocontagiosa, de caráter crônico e mais prevalente em áreas de vulnerabilidade socioeconômica. Objetivo: O objetivo foi avaliar a incidência de casos de hanseníase na região do Meio Oeste do estado de Sanda Catarina. Métodos: Trata-se de um estudo descritivo e analítico, que utilizou dados de pacientes diagnosticados com Hanseníase que foram notificados no Sistema de Informação de Agravos de Notificação (SINAN) entre o período de 2011 a 2021. Resultados: A busca resultou em um total de 100 casos notificados na região e período pesquisados, com predomínio de pacientes do sexo masculino (68 casos) e com predominância da faixa etária de 40 a 59 anos (50 casos). A maioria dos pacientes apresentavam ensino fundamental incompleto (56 pessoas). Grande parte dos pacientes no momento do diagnóstico apresentaram baciloscopia positiva, sendo classificados em multibacilares. Conclusão: Neste quadro, notamos a importância do diagnóstico precoce da hanseníase. Em muitos casos, quando diagnosticados, os pacientes já estão com grau de comprometimento avançado (GIF2). Assim, nota-se a relevância do diagnóstico precoce na prevenção e na erradicação da hanseníase.
Uso de corticoide no tratamento da Rinossinusite e da Rinite Alérgica: uma revisão de literatura
Authors: Fuzinatto Suellen Balbinoti , Vaccaro Valentina Skzypek , Martins Maria Julia , Focchesatto Stefani Peruzzo , Silveira Airton Junior da , Conto Rhaina Pagliocchi de , Zancanaro Vilmair
Published: May 2024

A rinossinusite (RS) é caracterizada por uma inflamação da mucosa nasal e dos seios paranasais, sendo uma das afecções mais prevalentes das vias aéreas superiores, ela é subdividida em aguda (viral, não-viral e bacteriana), subaguda e crônica. A partir disso, a Rinite Alérgica (RA) é considerada a doença crônica mais frequente no mundo, com início predominando em adolescentes e adultos jovens. Para atingir o objetivo proposto, realizou-se uma revisão narrativa de literatura e uma análise que permitem a busca por bibliografias indexadas em bases de dados como LILACs, Scielo, MEDLINE. Quanto aos resultados, os corticosteroides representam os medicamentos mais eficazes para a rinite alérgica. Com isso, nas abordagens de revisão, os autores empenham-se em interpretar e analisar criticamente a dinâmica entre o emprego de corticoides no tratamento de rinite alérgica e rinossinusite, com o objetivo de correlacionar os benefícios e os potenciais malefícios destes fármacos. Em até 99% dos casos ocorre resolução espontânea, sendo unicamente constituído de sintomáticos como: lavagem com salina estéril, spray nasal de glicocorticoide, anti-histamínicos e descongestionantes sistêmicos, já em 1% dos casos ocorre persistência dos sintomas para além dos 10 dias com piora clínica, havendo, nesses casos, coinfecção bacteriana. Com este artigo conclui-se que existe uma predominância no uso de corticoides, sejam eles intranasais ou orais, para tratar rinossinusite e rinite alérgica. A maioria dos pacientes relatam que os benefícios são sintomáticos e ajudam no sono, bem estar, ajudando nas atividades diárias. Outrossim, ainda existem controvérsias sobre o uso destes medicamentos.
Avaliação multiescala da Política Nacional de Educação Escolar Indígena (PNEEI) no contexto do Estado do Maranhão, Brasil
Authors: Silva Fabrício Brito , Assunção Ismael Duarte , Pereira Neto Paulo de Jesus , Silva Maria Raimunda Chagas , Melo Maycon Henrique Franzoi de
Published: May 2024

Este estudo avaliou a implementação e o impacto do Plano Nacional de Educação Escolar Indígena (PNEEI) no estado do Maranhão, Brasil, utilizando o Índice de Desenvolvimento da Educação Básica (IDEB) como principal indicador. A análise focou nas variações de desempenho no IDEB entre 2007 e 2019, destacando os avanços e desafios enfrentados pelas escolas indígenas na região. Apesar de melhorias graduais na infraestrutura e na matrícula estudantil, a falta de recursos sustentáveis e políticas governamentais consistentes ameaçam a eficácia do PNEEI. Através de uma metodologia de Avaliação de Impacto, investigamos a relação causal entre a implementação do PNEEI e as melhorias educacionais observadas, oferecendo insights sobre como fatores contextuais e socioeconômicos influenciam a eficácia da política. Os resultados indicam que, enquanto algumas comunidades mostram progresso significativo, outras continuam a enfrentar barreiras que impedem a igualdade no acesso à educação de qualidade. Este estudo contribui para o entendimento de como políticas educacionais direcionadas podem promover a justiça social e a preservação cultural, sugerindo a necessidade de adaptações nas políticas para atender melhor às necessidades específicas das comunidades indígenas maranhenses.
Viroses tropicais: análises clínicas e estratégias de controle
Authors: Duarte Raphaela Silva
Published: May 2024

A falta de acesso à água encanada é um desafio global que afeta milhões de pessoas, especialmente em comunidades marginalizadas. Isso resulta em problemas significativos de saúde pública, como a propagação de viroses transmitidas pela água e via oral-fecal, incluindo hepatite A, rotavírus e norovírus. Esta revisão aborda essas viroses, analisando estudos nas bases de dados Scielo e PubMed. Foram priorizados artigos gratuitos, examinando a relação entre água contaminada, falta de saneamento e viroses gastrointestinais. Dos 26 artigos encontrados, 18 estavam disponíveis gratuitamente, destacando uma concentração de estudos em hepatite A, rotavírus e norovírus, especialmente em centros de controle de viroses tropicais, com foco na população brasileira. A contaminação por esses vírus através da água foi mencionada em 63,6% dos estudos. Embora os estudos sobre rotavírus fossem predominantes, a pesquisa sobre todas essas viroses estava bem distribuída. A prevenção eficaz dessas viroses requer investimentos em saneamento, vacinação, educação em saúde e controle de infecções. Garantir água potável universal, melhorar a infraestrutura de saneamento e promover higiene são medidas cruciais para reduzir o impacto dessas doenças. Esta análise destaca a urgência de enfrentar as disparidades de acesso à água limpa e saneamento para combater as viroses e promover a saúde global.
Currículos de referência do Instituto Federal de São Paulo: um processo construído por muitas mãos
Authors: Lorenzi Carla Cristina Biazi , Silva Hilda Maria Gonçalves da
Published: May 2024

Os Currículos de Referência do Instituto Federal de São Paulo (IFSP) são documentos que agregam os principais elementos que estruturam todos os seus cursos, compreendendo o perfil esperado dos egressos, os objetivos de cada curso e os conhecimentos essenciais que devem fazer parte da formação dos estudantes. Originaram-se da necessidade de se discutir a identidade e a política de formação da instituição. Esse artigo tem como objetivo discorrer sobre as etapas de construção desses currículos e discutir o engajamento da comunidade acadêmica à luz dos princípios da gestão participativa, assim como as conquistas obtidas e os desafios enfrentados no decorrer do processo. Além da materialização dos documentos que servem para direcionar a elaboração e revisão dos projetos pedagógicos dos cursos do IFSP, a construção dos Currículos de Referência possibilitou reflexões importantes sobre a participação de toda a comunidade escolar, bastante necessária para que a diversidade pedagógica e a pluralidade de ideias permaneçam asseguradas no âmbito da instituição.
Cuidados de enfermagem para pacientes com insuficiência renal crônica em hemodiálise: uma revisão integrativa
Authors: Barrozo Michele Alves , Lima Eunara Eugênia Lopes , Pinheiro Maria do Socorro Saraiva , Santana Marttem Costa de , Alves Dayane Ferreira , Santos Vitória Yasmin Silva dos , Damasceno Stálin Santos , Paraguay Celso Ricardo , Santos Adelcio Machado dos , Silva Ricardo Ribamar da , Martins Guilherme Teodoro , Santana Gustavo da Silva , Lages Filho Patriotino Fontinele , Oliveira Érica Anunciação , Meneses Marcela Beatriz Botelho
Published: May 2024

O número de pessoas com doenças renais é crescente em todo o mundo e o Brasil já representa o terceiro maior mercado de hemodiálise, no qual é gasto 10% do orçamento do Ministério da Saúde com essa modalidade de tratamento. A Insuficiência Renal Crônica atinge, aproximadamente, 2 milhões de brasileiros, e destes, 70% tem dificuldades para conseguir atendimento especializado e diagnóstico, 70 mil estão em diálise e 25 mil já foram transplantados. Foi realizada uma pesquisa bibliográfica nas bases de dados acerca do tema em estudo. A qualidade do tratamento dialítico é influenciada pela performance da equipe de enfermagem. Dessa forma, as intervenções de enfermagem direcionadas aos diferentes acontecimentos com o paciente em hemodiálise e a educação permanente da equipe, são fatores que podem proporcionar uma melhor qualidade do cuidado de enfermagem e diminuir os sintomas de intercorrências durante o tratamento. Dessa forma, o enfermeiro precisa compreender como a doença e o tratamento afetam o paciente e como ele as interpreta, e, por meio da detecção de possíveis problemas, implementar as intervenções necessárias, a fim de propiciar a esses pacientes um ambiente mais acolhedor, que os auxilie no enfrentamento da situação vivenciada. Em suma, é possível concluir que os cuidados de enfermagem prioritários ao paciente durante o tratamento hemodialítico são: a monitoração dos sinais vitais; promoção do autocuidado; avaliação das vias de acesso para hemodiálise e realização de curativos, quando necessário; prevenção de infecções; controle da dieta; proporcionar suporte emocional; controle da dor; e, administração dos medicamentos prescritos.
Uso de jogos online para o ensino de enfermagem
Authors: Assis Daniele Costa de , Ferreira Sara Quézia Fonseca , Beserra Eveline Pinheiro , França Débora Feitosa de , Carvalho Francisca Maila Medeiros de , Silva Natália Vieira da , Melo Regina Cláudia de Oliveira , Santos Victor Emmanuell Fernandes Apolonio dos
Published: May 2024

Os jogos online podem ser utilizados como uma metodologia ativa, que visa incluir o aluno em seu processo educacional de forma lúdica e interessante. O objetivo deste relato é descrever a aplicação de jogos online no ensino de procedimentos básicos de Enfermagem. Trata-se de um relato de experiência sobre a elaboração e aplicação de jogos educativos em uma disciplina que aborda procedimentos básicos de Enfermagem do curso de graduação em Enfermagem de uma Universidade Pública. O uso da metodologia se encontrava aliado às monitorias da disciplina. Todos os jogos foram baseados nos conteúdos ministrados na disciplina, apresentavam instruções iniciais e respostas ao final, sendo enviados para os alunos gradativamente de acordo com os conteúdos abordados em sala. Os jogos surgem como facilitadores do processo educativo, como forma de complementar o processo de ensino aprendizagem. Conclui-se que os jogos online apresentam-se como uma ótima ferramenta de apoio ao ensino em Enfermagem.
Classificação do uso e cobertura do solo em uma unidade de conservação usando imagens Sentinel 1
Authors: Carvalho Wesley dos Santos , Oliveira Marcos Vinicius Alves de , Sousa José Hugo Simplicio de , Ávila Maria Eduarda Basílio de , Silva Eduarda Cristina Quevedo da , Guilherme Denilson de Oliveira
Published: May 2024

Compreender o uso e a cobertura do solo é fundamental para analisar uma variedade de fenômenos econômicos, sociais e ambientais na superfície terrestre. As diversas tecnologias atuais de sensoriamento remoto têm fornecido um grande número de sensores de observação terrestre, permitindo o monitoramento de sua dinâmica sob diversos aspectos. Os dados de sensoriamento remoto, especialmente o Sentinel-1 (SAR), são uma fonte importante para o mapeamento do uso e cobertura do solo, pois permitem a obtenção de informações da superfície terrestre em diferentes escalas e condições climáticas. O presente estudo tem por objetivo avaliar a aplicabilidade de dados Sentinel-1 para mapear o uso e cobertura do solo na Área de Proteção Ambiental APA Lajeado, localizada em Campo Grande/MS. O estudo utiliza uma abordagem baseada em múltiplas cenas empilhadas obtidas ao longo do ano para formar um único mapa com o uso e cobertura do solo na área de estudo. Foi testada a combinação das polarizações VV e VH, bem como a aplicação prévia de um filtro de mediana 3x3 nas cenas. Os resultados do estudo indicam que os dados Sentinel-1 são viáveis para mapear o uso e cobertura do solo com precisão, no entanto, ainda apresentam ruídos no resultado final mesmo com filtragem prévia das cenas. A Acurácia Geral variou de 64,26% a 84,53%, verificou-se ainda que o uso combinado das polarizações VV/VH é mais eficiente quando comparado com o uso isolado dessas polarizações.