Solid Body Research Articles

Igneous reasons why porphyry Cu–Au deposits are not magmatic

The presence or absence of porphyritic textures in host rocks has no meaning for the genesis of ‘porphyry’ deposits. ‘Magmatic’ quartz, intergrown with K-feldspar and associated with some porphyry mineralisation, is unequivocally hydrothermal. Experiments show that magmas cannot carry concentrations of Cl required to yield fluids that can deposit the metals in porphyry Cu–Au deposits, and this is substantiated by the Cl concentrations in fluid inclusions in both mafic and silicic igneous rocks. Other experiments show that magmas generally have lower Cu concentrations than average crustal rocks. Igneous fractionation cannot produce melts with the required Cl or metal contents. Experiments also show that, if highly saline brines (or halite deposits) were to have been present during crustal melting, the magmas produced would have mineralogical and chemical characteristics most unlike the rocks that commonly host porphyry mineralisation. The metals in porphyry deposits must come from the medium- to far-field wall rocks and were most likely precipitated in veins when the host rocks underwent brittle fracture and fluid decompression. While still cooling, completely solid intrusive bodies can act as thermal eyes in a terrane, setting up hydrothermal circulations with flow toward the intrusions and upward toward shallower levels. The idea that precursor batholiths might be responsible for the supply and concentration of metals and Cl is untenable for numerous reasons. What applies to shallow igneous systems also applies to deeper ones. Thus, if magmas cannot carry the required concentrations of Cu and Cl, this applies to the seen as well as the unseen and potentially non-existent. Economic mineral deposits everywhere represent exceptional phenomena, so it seems likely that there is also something systematically exceptional about the sources of the necessary Cl in fluids that form porphyry deposits. At present, that source remains unidentified, but the possible role of evaporitic rocks needs to be explored.

An Analytical Study of Tsunamis Generated by Submarine Landslides

In this work, the problem of tsunamis generated by underwater landslides is addressed. Two new solutions are derived in the framework of the linear shallow water equations and linear potential wave theory, respectively. Those solutions are analytical (1 + 1D) and another is semi-analytical (2 + 1D). The 1 + 1D model considers a solid body sliding over a sloping beach at a constant speed, and the 2 + 1D model considers a solid landslide that moves at a constant velocity on a flat bottom. The solution 1 + 1D is checked numerically using a different finite scheme. The 2 + 1D model examines the kinematic and geometric features of the landslide at a constant ocean depth and its influence on the generation of tsunamis. Landslide geometry significantly influences run-up height. Our results reveal a power law relationship between normalized run-up and landslide velocity within a realistic range and a negative power law for the landslide length–thickness. Additionally, a critical aspect ratio between the length and width of the sliding body is identified, which enhances the tsunamigenic process. Finally, the results show that the landslide shape does not have a decisive influence on the pattern of tsunami wave generation and propagation.

Jazz Musicians and Their Disabilities: Django Reinhardt, Les Paul, and Michel Petrucciani.

Musicians with physical disabilities who achieved stardom are part of the lore of popular music. Guitarist Django Reinhardt contrived alternate fingering patterns necessitated by burn contractures of his left hand. Les Paul, a legend in the development of the solid body electric guitar and multitrack recording, mangled his right arm in a car wreck so severely that his elbow was set permanently at 90° so he could continue to play guitar. Michel Petrucciani suffered from osteogenesis imperfecta, a condition that stunted his growth to the point where he used a special attachment to reach the sustaining pedals of his piano. Their stories show the force of human genius in music.

Cardiovascular profile of women in cardiac rehabilitation programs and its impact on their functional capacity

Abstract Background The value of cardiac rehabilitation (CR) for patients with a wide spectrum of cardiovascular diseases is supported by a solid body of scientific evidence. It has demonstrated improvement in cardiopulmonary capacity and physical endurance, as well as a reduction in morbidity, mortality and rehospitalization. Despite these benefits, it is an underutilized resource among women. Purpose Our objective was to study the clinical characteristics of women included in our CR program, as well as the evolution of their functional capacity, in comparison to men. Methods A retrospective observational study was conducted and consecutive patients who had participated in the CR program at our center, between the years 2019 and 2022, were included. Clinical characteristics and the evolution of functional capacity throughout the program were assessed, stratified by gender. Results 175 patients were included and subdivided by gender into two groups: 144 males and 31 females. The mean age was slightly higher among the female patients, without reaching statistical significance, and the body mass index was similar in both groups. Ischemic heart disease was the primary reason for inclusion in 80% of cases. Within the female patients, 52% had hypertension (p=0.04) and 20% had diabetes (p=0.09), percentages slightly lower than those in males; a similar percentage of patients had dyslipidemia in both groups (see table). The initial METs in ergometry [7.6 (6.3-10.2) among male patients and 4.6 (4.4-6.9) among female patients], and the final METs [10 (8.1-11.3) and 6.8 (5.6-7.6), respectively], were higher in the male group, with a significant increase in METs at the end of the CR program in both groups. Nonetheless, the absolute increase in METs was similar in both males and females. Conclusions Cardiovascular risk factors are more prevalent among males. CR programs demonstrate an improvement in functional capacity (defined as an increase in METs) in both males and females, with a similar absolute increase in METs for both genders. Therefore, we must increase our efforts to include more women in CR programs.

Influence of explosive type and constant γ in Mott’s stochastic model on terminal-ballistics parameters of high-explosive warheads using numerical simulations

The research examined the use of numerical simulations for high-explosive (HE) munitions. Lagrange and Euler solvers from Ansys Autodyn, whose brief theoretical synopsis is given, were utilized. Numerical program modeling of materials under dynamic loads (explosives and solid bodies) is also explained. The study also provides a brief summary of relevant research works that address numerical simulations of the fragmentation of HE projectiles (warheads). First, using data from other authors, the numerical model in this paper was effectively validated. The original research in the publication included an evaluation of the influence of explosive type on mass distribution, as well as velocity and the kinetic energy of fragments on cylindrical warheads, along with some recommendations and findings. Results show that ordered by values of initial fragment velocity are explosives: Trinitrotoluen (TNT), H6, Comp. B, Octol, PBX-9404-3, and LX-10-1. Explosives LX-10-1 and PBX-9404-3 showed similar performance because both explosives are HMX-based mixtures, with LX-10-1 having 0.5% more Octogen (HMX). The greatest (fastest) expansion of fragments (for the given time frame of 150 µs) is present in the most potent explosives (LX-10-1 and PBX-9404-3) since they have the largest detonation velocities. In the configurations with stronger explosives (Octol, LX-10-1, PBX-9404-3), the front and rear cover of the cylinder is more fragmented than in the case of weaker explosives. The highest number of fragments is obtained with PBX-9404-3 explosive, 142% higher than using TNT charge. Also, as part of the original research in the paper, an assessment of the influence of the constant γ in Mott’s stochastic fragmentation model on the mass distribution of fragments and their kinetic energy was made. Results indicate that constant γ has the greatest influence on the number of very small fragments, which can be used when calibrating this constant with experimental data. The masses of fragments are relatively uniform (for all γ values) up to the mass group of 50–100 g, above which the most massive fragments are obtained when γ = 5. Most of the fragments have relatively high energy where that is, fragments of mass 0.5–2 g have an average kinetic energy of 470–650 J, while fragments of masses 50–100 g have an average kinetic energy of 50–85 kJ. Described numerical simulations are a valuable tool for HE warhead designers, as they can minimize the time and expense associated with optimizing HE munition design and effectiveness evaluation when used in conjunction with available analytical techniques and experimentation procedures.

The use of interphacial energies to estimate the spreading coefficients of organic liquids by the solid polymer surface of polytetrafluoroethylene

In the article, using equations previously obtained by the author, calculations were made of the interfacial energies of a solid polymer – polytetrafluoroethylene in contact with organic liquids and their vapors. Based on the calculation results, the spreading coefficients in the studied systems were calculated. Since Young’s derivation of the equation for the cosine of the contact angle, many researchers have attempted to determine the surface energy of solids, which would, in turn, make it possible to determine the interfacial energy at the solid-melt (liquid) interface. However, on the way to solving this problem there were obstacles associated with various processes that accompany phenomena occurring on the surface of a solid body in the presence of a liquid (melt) of another body on its surface. This is not the place to list all types of processes. They are well known to specialists in the field of surface phenomena. Here are just a few of them that affect the surface properties of bodies: chemical reactions, mutual dissolution of components of solid and liquid phases, deformation of solid phases, etc. In the case of contact of the polymer with organic liquids, such obstacles do not exist. Also, since it is impossible to dwell on all publications devoted to the determination of the surface energy of solids, the article discusses specific works on determining the interfacial energy at contact angles close to or equal to zero. Since the question of the behavior of interfacial energy at a contact angle equal to zero is of fundamental importance, and there are conflicting opinions in the literature on this matter, giving the correct answer to this question is an urgent task. Using examples of calculations of interfacial energies of homologous series of organic liquids on a solid surface of polytetrafluoroethylene, we have shown that only at zero contact angle the interfacial energy is zero. In this article, using interfacial energy values, we are the first to calculate the spreading coefficients of organic liquids over the surface of a solid polymer, which, in our opinion, is also an urgent task.

The process of superdeep penetration of high-speed metallic particles in solid body

An explanation of the effects arising at the collision of a stream of metal particles with a size of 10–100 microns, moving at a speed of 1–3 km/s, with a solid target is proposed. It is assumed that at the moment of impact on the target, the particle loses some electrons and for some time, due to the presence of an oxide shell, retains a positive charge. The flow of electrons passing through the target at the moment of impact generates an electromagnetic field pulse. A particle with a charge of about 10–9 C, having penetrated into a solid target, presses on the channel wall with a force of about 500 MPa and moves in it under the action of forces caused by the polarization of the target substance. The combination of high pressure and displacement leads to a significant reduction in the particle-wall friction force. The proposed hypothesis, if confirmed, can help find ways to protect electronic devices of spacecraft from impacts from streams of fast dust particles.

Tensile strength of a specific specimen determined with a UTM (25KN)

The goal of this experiment is to apply a tensile force to a test specimen until the specimen is pulled to failure. The computer will track the properties during the application of the tensile load and produce a stress/strain curve that will allow for the determination of several values, including the material's modulus of elasticity. Any solid body will bend totally elastically if the load is small enough. As soon as the load is released, a solid that has been elastically deformed will revert to its original shape. On the other hand, the material may become permanently distorted if the load is too great. The first section of the tension curve that can be found as soon as the load is released is called. The aim of this experiment is to draw a test specimen to failure by applying a tensile force to it. The computer will track the properties during the application of the tensile load and produce a stress/strain curve that will allow for the determination of several values, including the material's modulus of elasticity.

Analytical Theory of Reflection of Hydrogen Isotopes of Thermonuclear Energies from Construction Materials

A theoretical description of reflection of hydrogen isotopes from a solid body based on data available in modern literature on the cross sections for elastic and inelastic scattering of ions is presented. The results of the analytical calculation are compared with the results of computer simulation and experimental data. The interaction of hydrogen isotopes with energies from 300 eV to 25 keV with materials in a wide range of atomic numbers, namely Be, C, Ti, Ni, W, Au, is considered. A critical review of existing analytical models of multiple scattering of light ions in solids is performed.

Study of damage progression due to impact of solid bodies on laminated composite plates in water

Study of damage progression due to impact of solid bodies on laminated composite plates in water

The Feasibility of Asynchronous Rotation via Thermal Tides for Diverse Atmospheric Compositions

The equilibrium rotation rate of a planet is determined by the sum of torques acting on its solid body. For planets with atmospheres, the dominant torques are usually the gravitational tide, which acts to slow the planet’s rotation rate, and the atmospheric thermal tide, which acts to spin up the planet. Previous work demonstrated that rocky planets with thick atmospheres may produce strong enough thermal tides to avoid tidal locking, but a study of how the strength of the thermal tide depends on atmospheric properties has not been done. In this work, we use a combination of simulations from a global climate model and analytic theory to explore how the thermal tide depends on the shortwave and longwave optical depth of the atmosphere, the surface pressure, and the absorbed stellar radiation. We find that for planets in the habitable zones of M stars only high-pressure but low-opacity atmospheres permit asynchronous rotation owing to the weakening of the thermal tide at high longwave and shortwave optical depths. We conclude that asynchronous rotation may be very unlikely around low-mass stars, which may limit the potential habitability of planets around M stars.

The Process of Superdeep Penetration of High-Speed Metallic Particles into a Solid Body

The Process of Superdeep Penetration of High-Speed Metallic Particles into a Solid Body

Planetary Geologic Maps: Essential Tools for Scientific Inquiry and Space Exploration

AbstractPlanetary geologic maps are crucial tools for understanding the geological features and processes of solid bodies in the Solar System. Over the past six decades, best practices in planetary geologic mapping have emphasized clear and objective observation, geological interpretation, multi‐sensor fusion, and iterative revision of maps based on new data. We summarize here four ways in which maps serve as indispensable instruments for scientific investigation, from enhancing observations to interrogating surface processes. With respect to space exploration, we underscore the role of planetary geologic maps as tools to link testable, hypothesis‐driven science to exploration goals and provide actionable information for hazard identification, resource evaluation, sample collection, and potential infrastructure development. To further advance the field of planetary geologic mapping, international collaboration is essential. This includes sharing data and maps through FAIR (findable, accessible, interoperable, and reusable) platforms, establishing standardized mapping practices, promoting diverse nomenclature, and fostering continued cooperation in space exploration.

Про стійкість обертання вільної системи двох пружно зв’язаних гіроскопів Лагранжа, один з яких має ідеальну рідину

On the basis of the known equations of motion of the system of coupled gyrostats by P. V. Kharlamov and the state function by S. L. Sobolev, the equations of rotation of a free system of two elastically coupled Lagrange gyroscopes were derived, one of which has an arbitrary axisymmetric cavity completely filled with an ideal incompressible fluid. The rigid bodies are connected by an elastic restoring spherical hinge. A transcendental characteristic equation of the perturbed uniform rotation of the mechanical system under consideration is derived. Taking into account the fundamental tone of the fluid oscillation, a characteristic equation of the fifth order is obtained. On the basis of the Liénard – Chipart criterion written in the inor form, the necessary conditions for the stability of the uniform rotation of the Lagrange gyroscopes and the fluid are written out as a system of four inequalities. With respect to the elasticity coefficient, these inequalities have degrees 1, 3, 6 and 8, respectively. Analytical studies of the leading coefficients of these stability conditions are carried out. It is shown that when the center of mass of the first solid body with liquid or the second does not coincide with the common point of these bodies, then at sufficiently large values of the elasticity coefficient the necessary stability conditions will always be satisfied. In the absence of elasticity in the hinge, the characteristic equation has a double zero root and in this case the stability conditions require additional studies. The obtained stability conditions are exact for an ellipsoidal cavity and approximate for other axisymmetric cavities. To clarify the obtained glass conditions for these voids, it is necessary to take into account additional tones of oscillation of an ideal liquid.

Conrad Wilhelm Roentgen in the Reflection of Commemorative Medals and Coins

Аnnotation In this research article, its author presents the results and analysis of his research devoted to the study of the issue of representing the memory of the famous German scientist, Nobel Prize winner, Conrad Wilhelm Roentgen, in the reflection of such a collecting tool as numismatics - on 45 commemorative medals and coins, issued for circulation and timed to coincide with various events, by a number of countries around the world, in different years. Aim of studyThe purpose of this article is to present the results of the research conducted by the author, thematically dedicated to the issue of reflecting the memory of the German scientist, Nobel Prize (1901) winner in physics, Conrad Wilhelm Roentgen, in such a collecting medium as numismatics, on commemorative medals and commemorative coins, accompanied by their image (obverse and reverse), with accompanying comments. Research objectives 1. Find any sources of information regarding the reflection of the memory of Conrad Wilhelm Roentgen in various collecting media. 2. Select and systematize all found numismatic materials, both commemorative medals and commemorative coins dedicated to this scientist. 3. Convert all found numismatic materials into color and black and white screenshot copies. 4. Conduct an analysis of all the results obtained as a result of the scientific research carried out by the author of the article. with their help, form the text part of this research article. 5. From all the data obtained, both textual and illustrative, form a solid body of this research and author’s article. Hypothesis of the study In the process of starting to prepare for this study, its author came up with the following working hypothesis - there is a fairly large amount of a wide variety of collection materials, not only philatelic and phaleristic, but, first of all, numismatic - on commemorative medals and coins dedicated to the memory, about the life and scientific activities of the famous German physicist and inventor, Conrad Wilhelm Roentgen, in the reflection of numismatic materials, different years of issue and many countries of the world, in the form of commemorative medals and coins dedicated to him.

Алгоритмы группового управления подводными подвижными объектами

The problem of formation control is relevant when searching for objects, surveying a given area, and group monitoring. In the underwater environment, this problem is complicated by restrictions on the frequency of receiving navigation data and the speed of information exchange between underwater robots. The purpose of this article is to develop and study group control algorithms that ensure the given formation and the maintenance of this formation during movement. The article provides an overview of the results in the field of group control of underwater vehicles, provides a mathematical model of the object, navigation system, underwater environment and communication system. The equations of kinematics and dynamics of a solid body in three-dimensional space, supplemented by equations of actuators, are used as a mathematical model. Algorithms for the distribution of moving objects in formation and nonlinear control algorithms for moving in a line are proposed. When constructing the devices, it is assumed that there is a group leader who transmits his coordinates to the rest of the underwater robots. Motion control is synthesized by the method of positional trajectory control in the form of a function of external coordinates. A study was carried out using numerical methods, during which the process of the formation and movement along the trajectory described by straight line segments was studied. The influence of errors in the navigation system and the frequency of data updates on the error of maintaining a given position by a separate underwater robot is investigated.

Archimedean solids in the fifteenth and sixteenth centuries

Several artists, artisans, and mathematicians described fascinating solid bodies in the fifteenth and sixteenth centuries. The knowledge they developed on the subject was so progressive that it is considered a milestone in the history of polyhedra. In the first part of this study we analyze, from a chronological and comparative perspective, the consistent studies developed between 1460 and 1583 on those that came to be recognized as Archimedean Solids. The authors who engaged in such studies were Piero della Francesca, Luca Pacioli, Leonardo da Vinci, Albrecht Dürer, Augustin Hirschvogel, an Anonymous Author who accomplished remarkable studies between 1538 and 1556, Wentzel Jamnitzer, Daniele Barbaro, Lorenz Stöer, Rafael Bombelli, and Simon Stevin. In the second part, we discuss how the revolutionary method of describing solid bodies with planar nets contributed to the rediscovery of the Archimedean Solids. We also present our interpretation of some of the studies by the Anonymous Author and our conclusions on his identity and influence on other authors.

A simple approach to transient-state modeling of nitrogen cooling in the extrusion of light-alloy complex profiles

Abstract Nitrogen cooling has become a popular solution to reduce heat flux between the die and the profile in the hot extrusion process. However, designing effective cooling channels for complex-shape profiles poses challenges, especially when the phase transition of nitrogen significantly impacts heat transfer with solid bodies. To this end, the ability to model both the liquid and the gas phase is instrumental in devising design strategies, yet it should be combined with low computational complexity for industrial applications. The present work is aimed at employing the homogenous-flow approach as a simple, yet representative methodology to consider both phases in the simulations. One-dimensional model of nitrogen was combined with a three-dimensional extrusion model to perform the transient analysis of the whole process, mostly focused on the transition from fully gaseous to fully liquid flow. Validation using extrusion tests on seventeen AA6060 billets demonstrates the model's predictability in comparison with a fully liquid model. The average error associated with Homogeneous Flow Model was evaluated as below 10%, whereas the fully liquid approach yielded 25%. That proved the ability of the proposed model to reproduce the cooling effect, thus supporting the design of the cooling subsystem within the context of the whole extrusion tooling.

Uncollected Solid Waste Detection and Reporting Using Machine-learning and Geotagging

Uncollected solid waste has become an ever-growing threat to our livelihoods, posing many problems that span health risks, environmental pollution, and unpleasant aesthetics. Traditional methods of reporting uncollected solid waste have proven ineffective and we struggle to keep pace in addressing the growing volumes of waste. This study focused on developing a solid waste detection and reporting system based on machine learning and geotagging. The developed system sought to enable solid waste management entities to obtain verified solid waste reports and accurate location details of the uncollected waste instances. A ResNet model was trained on commonly used solid waste image datasets from online sources. The model achieved a provisional accuracy beforescore of seventy percent (70%) though this statistic can be improved by adjusting model parameters. A rapid iterative design approach was employed to facilitate the development of the crowdsourcing app. This enabled the researchers to swiftly build, evaluate, and refine functional prototypes of the system before finalization. The resulting system receives solid waste images together with their location data and verifies the correct image reports using the trained model, before finally visualizing the reports on a map. Overall, the system provides a platform for the general public to collaborate with solid waste management bodies in combatting uncollected solid waste. In the future, the system may be diversified to allow reporting other amenity issues besides uncollected solid waste.

Analysis of the stress-deformed state of the structure of road clothing depending on the location of the load relative to the edges of the combined slab

Abstract. Problem. Cement-concrete coatings are characterized by the complexity of repair work, therefore, for their repair or new construction, it is advisable to use asphalt-concrete coating. This constructive solution during the repair of cement concrete slabs helps to improve their technical and operational condition since the asphalt concrete layer performs the function of a protective or wearresistant layer on cement concrete slabs. The operating conditions of asphalt concrete layers on cement concrete slabs are significantly different from those typical for other structural solutions. The existing methods of calculating the strength of asphalt concrete coatings for hard road wear are not accurate enough, because they take into account only certain criteria of the strength of the asphalt concrete layer. The specifics of the stress-strain state of the asphalt concrete layer on cement concrete slabs under different load conditions, such as the middle of the slab, the edge of the slab, and the corner of the slab, are not taken into account. Given the complex stressstrain state of the asphalt concrete layer on a rigid base, the analysis of the stress-strain state is particularly relevant, aimed at determining the most dangerous variant of the location of the transport load to ensure the strength of the asphalt concrete layer. Goal. The purpose of this article is to determine the stress-deformed state of an asphalt concrete layer on a rigid base with various options for applying a transport load, which will allow the establishment of the most dangerous option for the location of the load. Methodology. General methods of solving problems of the mechanics of a deformed solid body were used to develop a calculation scheme and select a material model. Simulation of the stress-strain state of the road surface was carried out using the finite element method using the ANSYS software complex, investigating three options for placing the transport load: in the center of the slab, on its edge, and in the corner. Results. According to the results of the simulation of the stress-strain state of a combined slab made of an asphalt concrete layer on a rigid base, it was established that the edge of the slab is the most unsafe both in terms of tensile and shear stresses for a cement concrete slab. For the asphalt concrete layer, placing the load in the corner of the slab is the most dangerous both in terms of tangential shear stresses and Mises stresses. Originality. According to the results of the simulation of the stress-strain state of a combined slab made of an asphalt concrete layer on a rigid base, it was established that the edge of the slab is the most unsafe both in terms of tensile and shear stresses for a cement concrete slab. Practical value. Based on the results of modeling the stress-strain state of a combined slab made of an asphalt concrete layer on a rigid base, it was established that the edge of the slab is the most dangerous both in terms of tensile and shear stresses for a cement concrete slab. For the asphalt concrete layer, placing the load in the corner of the slab is the most dangerous both in terms of tangential shear stresses and Mises stresses