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We have studied the electron–electron interactions in the system composed of two metallic one-dimensional point contact and zero-sized wires, in the applied electric field and exposed to the influence of the external Zeeman magnetic field. The interactions between the electrons within wires have been taken into account within the usual Hubbard model. We have considered different limits of particle-filling on the atomic lattice site positions. We show the existence of the excitonic pairing in this one-dimensional system in different limits of the electron–electron interactions, magnetic field, and temperature. We demonstrate that the usual Hubbard- U interaction leads to strong electron localization, which enhances the local antiferromagnetic order in the system. [ABSTRACT FROM AUTHOR]

Additive manufacturing has the potential to repair damaged parts, but the performance of additive materials under high strain rate loading is still uncertain—especially with the added complexity of an interface with an existing wrought material. In this work, 304L stainless steel samples were intentionally damaged and then repaired with wire-fed laser additive manufacturing. The samples were subjected to shock loading to generate incipient spall. Velocimetry and post-mortem metallography results show that when the additive repair process parameters are optimized to reduce porosity and match the equation of state of the original material, the influence of the repair region on the shock propagation is negligible. The free-surface velocity profile and internal damage morphology of the repaired sample are shown to be practically identical to the pristine material. [ABSTRACT FROM AUTHOR]

Electrothermal instability and its effect on the uniformity of discharge channels during underwater electrical wire explosions at different energy deposition rates have been investigated. According to the liquid–vapor transition mechanism, we classified underwater electrical explosion into "phase explosion mode" and "supercritical mode." Two sets of experiments corresponding to the two modes were conducted, and the exploding wires were observed by a shadow imaging system. Results showed that a bamboo-shaped discharge channel was formed in the phase explosion mode, whereas the discharge channel in the supercritical mode was a uniform cylinder. Self-consistent magnetohydrodynamic simulation results indicated that exploding wires transfer into liquid–vapor coexistence phase in the phase explosion mode, accompanied by a rapid increase in the density perturbation and the formation of bamboo-shaped structures. Moreover, a small perturbation model was derived to analyze the electrothermal instability in different thermodynamic states. It was indicated that the density perturbation is easier to grow in the liquid–vapor coexistence state than the supercritical state, which provides a theoretical explanation for the differences between the two electrical explosion modes. [ABSTRACT FROM AUTHOR]

Due to the advantages of both the metallic and glass fiber qualities, glass fiber reinforced metal layers are one of the best impact resistant materials. Shape memory alloys have also been thought to be effective materials for equipping the traditional impact-exposed materials due to their high impact damping capabilities. The modal response (natural frequencies, damping, and vibration amplitude) of the laminate composite constructions that incorporate shape memory wires was experimentally investigated in this article. The goal of the current research is to ascertain how the modal responses are impacted by three production parameters: wire diameter, wire location, and wire number. Using an experimental design plan and a central composite design, hybrid specimens were planned. The results showed that the manufacturing variables influence all the modal responses in different proportions. Regarding the innovations in the construction of this type of hybrid composite, this study could be used in the design of mechanical and airspace structures. [ABSTRACT FROM AUTHOR]

In the present work, a high-pressure spherical vessel was fabricated from Ti–4Al–3V titanium alloy using wire-feed electron beam additive manufacturing and characterized for tightness at high pressure. Studies have been carried out to characterize the microstructures and properties of the vessel's material in four states: as-built (BM), annealed at 940 °C with cooling in air (HT1 treatment), quenched in water from 940 °C (HT2 treatment), and quenched with subsequent annealing at 540 °C (HT3 treatment). The microstructure of the as-built (BM) samples was composed of grain boundary α-Ti and α/β lath colonies located within the columnar primary β-Ti grain boundaries. The ultimate tensile strength of the as-built material was in the range of 582 to 632 MPa, i.e., significantly lower than that of the source Ti–4Al–3V alloy wire. The subtransus HT1 heat treatment allowed β→α″ transformation, while both HT2 and HT3 resulted in improved tensile strength due to the transformation of β-Ti into α/α′-Ti and the decomposition of α′ into α/β structures, respectively. [ABSTRACT FROM AUTHOR]

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Traditionally, structural wire is characterized by a homogeneous microstructure, where the average grain size in different parts of the wire is uniform. According to the classical Hall–Petch relationship, a homogeneous polycrystalline metal can be strengthened by decreasing the average grain size since an increase in the volume fraction of grain boundaries will further impede the motion of dislocations. However, a decrease in the grain size inevitably leads to a decrease in the ductility and deformability of the material due to limited dislocation mobility. Putting a gradient microstructure into the wire has promising potential for overcoming the compromise between strength and ductility. This is proposed a new combined technology in this paper in order to obtain a gradient microstructure. This technology consists of deforming the wire in a rotating equal-channel step die and subsequent traditional drawing. Deformation of copper wire with a diameter of 6.5 mm to a diameter of 5.0 mm was carried out in three passes at room temperature. As a result of such processing, a gradient microstructure with a surface nanostructured layer (grain size ~400 nm) with a gradual increase in grain size towards the center of the wire was obtained. As a result, the microhardness in the surface zone was 1150 MPa, 770 Mpa in the neutral zone, and 685 MPa in the central zone of the wire. Such a symmetrical spread of microhardness, observed over the entire cross-section of the rod, is a direct confirmation of the presence of a gradient microstructure in deformed materials. The strength characteristics of the wire were doubled: the tensile strength increased from 335 MPa to 675 MPa, and the yield strength from 230 MPa to 445 MPa. At the same time, the relative elongation decreased from 20% to 16%, and the relative contraction from 28% to 23%. Despite the fact that the ductility of copper is decreased after cyclic deformation, its values remain at a fairly high level. The validity of all results is confirmed by numerous experiments using a complex of traditional and modern research methods, which include optical, scanning, and transmission microscopy; determination of mechanical properties under tension; and measurement of hardness and electrical resistance. These methods allow reliable interpretation of the fine microstructure of the wire and provide information on its strength, plastic, and electrical properties. [ABSTRACT FROM AUTHOR]

The focus of the present study is to rigidize the toroidal member of an inflatable space antenna using a novel rigidization technique. This technique involves embedding heat-actuated Shape Memory Alloy (SMA) wires between laminated Kapton layers to provide structural strength. Finite Element Analysis (FEA) is performed to assess the strength of the torus under a heating environment. The analysis considers the approach of constraining torus deployment in all directions, simulating the conditions it would experience during deployment and operation. By subjecting the torus to a heating environment, the behavior of the SMA wires can be observed, which in turn affects the rigidity and strength of the structure. In addition to the numerical analysis, experiments are conducted to verify the feasibility of the design and strategy. The material properties of the involved materials, such as Kapton and SMA wires, have been determined through separate experimental investigations and incorporated into the FEA tool as input parameters. Furthermore, a parametric study is conducted to examine the impact of design and material parameters on the strength of the toroidal structure. The study demonstrates that a 1-meter diameter toroidal structure based on SMA wires can offer structural strength during partial or complete venting scenarios. [ABSTRACT FROM AUTHOR]

The evaluation of available Look-Up Tables for prediction of heat transfer coefficient distribution in rod bundles cooled by supercritical water with the aim of their further use in computational analyses of various Fuel Assembles of Supercritical Water-Cooled Reactors is made. The comparison between the calculations based on Look-Up Tables with the values from empirical correlations and experimental data for smooth and wire-wrapped rod bundles was presented. The obtained results showed that Look-Up Table of the University of Ottawa, which was created to describe improved and deteriorated heat transfer regimes in round tubes, allows describing available data points with 30 % of the mean square deviation. It is noted that the presence of wire intensifies heat transfer exchange near pseudocritical temperature region but existing versions of Look-Up Tables cannot take into account this effect. Nevertheless, there is potential for further improvement in predicting the heat transfer coefficient using Look-Up Table by introducing additional correction factors.

The dynamics of wire frame particles in concentrated suspension are studied by means of a 2D model and compared to those of rod-like particles. The wire frames have bent or branched structures constructed from infinitely thin, rigid rods. In the model, a particle is surrounded by diffusing points that it cannot cross. We derive a formal expression for the mean squared displacement (MSD) and, by using a self-consistent approximation, we find markedly different dynamics for wire frames and rods. For wire frames, there exists a critical concentration of points above which they become frozen with the long time MSD reaching a plateau. Rods, on the other hand, always diffuse by reptation. We also study the rheology through the elastic stress, and more striking differences are found: the initial magnitude of the stress for wire frames is much larger than for rods, scaling such as the square of the point concentration, and above the critical concentration, the stress for wire frames appears to persist indefinitely while for rods it always decays. [ABSTRACT FROM AUTHOR]

An array of Rashba-coupled semiconducting nanowires lying in proximity to an s -wave superconducting substrate, with weak inter-wire coupling, in the presence of an external magnetic field shows even–odd effect in the differential conductance over a chosen parameter space. Such an effect is a direct consequence of end Majoranas in each nanowire hybridizing into bonding and anti-bonding states. In the present work, we study in detail the impact of tilting of external magnetic field on the differential conductance of an array of both uncoupled and weakly coupled wires. The phase diagram evolution with various control parameters including the tilt angle of the magnetic field has also been presented. From detailed analysis of the field-angle dependence of the odd–even effect, and the evolution of the same over a large parameter space we summarize that the results can be used to exploit magnetic-field angle in an array of Rashba-coupled semiconducting nanowires on a superconducting substrate as an important tuning parameter to investigate zero-bias conductance peak arising from Majorana edge modes vis-a-vis that arising from a non-topological origin. [ABSTRACT FROM AUTHOR]

This article contains an advanced analysis of the properties of solid wire electrical contacts produced by ultrasonic welding, both with and without varnish. The main disadvantage of ultrasonic welding of thin wires is the inability to achieve acceptable peel force and tensile strength, which is mainly due to the deformation and thinning of the wires. This study deals with ultrasonic welding using a ring of thin solid copper wires that minimises the deformation and thinning of the wires. The influence of welding parameters such as energy, pressure and amplitude were systematically analysed. Based on these parameters, the optimum welding programme and control method was determined to weld unvarnished and varnished wires. The investigations included electrical resistance tests, optical microscopy, micro-hardness measurements, peel tests and tensile tests, and the measurement of energy consumption. The results showed no significant differences in microstructure and hardness between varnished and unvarnished joints. Ultrasonic joints of varnished wires achieved lower electrical conductivity (by 38%), lower tensile strength (by 3%) and higher peel strength (by 7%), while the welding process was more sustainable in terms of energy (by 6.6%) and time consumption (without preprocessing). [ABSTRACT FROM AUTHOR]

The wire coating method is an engineering development to cover a wire for wadding, motorized forte and ecological protection. In wire coating analysis, moreover, the polymer extruded on the wire is hauled into interior of a die occupied with melted polymer. By considering this significance, the magneto-hydrodynamic flow and heat transmission of Oldroyd-8 constant fluid with suspension of nanoparticles in the wire coating development had been investigated. The fluid with fixed viscosity is considered in porous medium. The flow is conducted with uniform magnetic field. The arising physical governing system is modelled mathematically. The mathematical model is executed by incorporation of thermal radiation and nanoparticles (Embedded in water + hematite nanoparticles). The wire coating is scrutinized mathematically with four cases ((Ω = 0. 5 , ∅ = 0) , Ω = 0. 5 , ∅ = 0. 0 5 , Ω = − 0. 5 , ∅ = 0 , Ω = − 0. 5 , ∅ = 0. 0 5) with constant viscosity and also included in the Reynolds model for constant viscosity. The subsequent flow and heat transmission system were elucidated via the Runge–Kutta technique and the possessions of appropriate governing factors are presented in graphically. The outcome of the current investigation was equated with the previous available outcomes as a specific situation. The results were executed with nanofluid and without nanofluid as well as with positive and negative pressure gradients (Ω = 0. 5 , ∅ = 0) , Ω = 0. 5 , ∅ = 0. 0 5 , Ω = − 0. 5 , ∅ = 0 , Ω = − 0. 5 , ∅ = 0. 0. It is seen that the temperature circulation is augmented due to the upsurge in magnetic parameter M. It is interesting to note that the positive pressure gradient with nanofluid has less momentum distribution compared to rest of the cases. It is also noted that the with negative pressure gradient, the distribution is more compared to positive pressure gradient case. [ABSTRACT FROM AUTHOR]

The paper presents the findings of research on the production of wire from 850 and 585 platinum-based alloys intended for use in jewelry chains. The chemical compositions of two novel jewelry alloys of 585 platinum-containing modifying additives of rhodium and ruthenium are proposed and patented. An analysis was carried out to evaluate the existing section rolling and drawing schedules for the three platinum alloys to identify more efficient drafting methods, with a focus on reducing the labor intensity of metal deformation processes and minimizing the force parameters. A computer model of section rolling for the studied jewelry alloys, based on 850 and 585 platinum, was developed to analyze the shape variation and force parameters of the process and to propose a new deformation schedule for the studied alloys with the accepted reduction distribution per pass. The new deformation schedule was characterized by a more uniform reduction distribution per pass than that observed in the existing schedule, allowing the number of rolling passes to be reduced due to their redistribution. In order to determine the rolling force and to model the process, an approximation formula was used to calculate the time resistance, which is dependent on the total degree of compression. By using proprietary software and computer simulation, the parameters of wire drawing with a diameter of up to 0.25 mm from the studied alloys were calculated, which allowed the deformation and force parameters to be assessed when implementing the proposed drafting schedule. In addition, it was established that the drawing process exhibits a sufficiently high safety factor and low power consumption. It is therefore recommended that the process be subjected to industrial testing. The findings of this research can be recommended for improving the technology of wire manufacturing from the 850 and 585 platinum alloys intended for jewelry chains. [ABSTRACT FROM AUTHOR]

The article is devoted to the complex challenges associated with the development of welding wire for welding high-strength steel in shielding gases. In the development of welding wire, it is essential to address a number of considerations related to the resistance of welded joints to hot and cold cracking, wire production technology, the regulatory level of mechanical properties, the manufacturability of the welding process, and the environmentally friendly working conditions of welders. These factors should be taken into account when determining the chemical composition of the wire. This is a challenging and multifactorial task related to optimizing the chemical composition of the wire in order to ensure compliance with all of the aforementioned requirements. The formation of cold cracks in welded joints of steels that have undergone electroslag remelting can be prevented by increasing the austenitic stability of the weld metal. This can be achieved by increasing the nickel content in the welding wire. However, this results in a decrease in the resistance of the weld metal to the formation of hot cracks and a reduction in hot ductility. This makes the technology of metal rolling for wire manufacture more challenging. To enhance the resistance of the weld metal to the formation of hot cracks, it is necessary to increase the chromium content in the welding wire. However, this approach results in an increase in the ferritic phase within the weld, which subsequently leads to a reduction in the resistance of the welded joint to the formation of cold cracks. The results of the research on the effect of the chemical composition of welding wire, when varying the Creq/Nieq ratio, on the indicators of technological strength were used to optimize the composition of the new welding wire. The experimental data on the properties of welded joints of high-strength steels made with a new welding wire demonstrated an advantage over serial joints manufactured with the Sv-08Kh20N9G7T grade wire. Furthermore, the studies of the welding aerosol showed a 6.6-fold reduction in the content of toxic manganese oxides when welding with the new wire in comparison to the conventional Sv-08Kh20N9G7T. [ABSTRACT FROM AUTHOR]

In the present context of the exponential development of green energy obtained through photovoltaic panels or wind turbines, one of the immediate and essential requirements is the transport of this energy over long or very long distances. The only existing and efficient method is the use of copper or aluminum metal conductors. In this context, worldwide requirements are extremely high and the production of electric cables is already contracted for the next 2,3 years by the producers in the field. The operation of wire drawing installations is based on the general use of medium or large machines in which translational or rotational movements are carried out with a high risk of injury. In this sense, this work presents the latest improvements regarding the reduction of the risks of accidents of existing machines in such an industry. These improvements primarily help to eliminate the risks of injury to human personnel as well as to achieve a continuous production, with as little risk of interruption as possible and thus obtain a high work productivity. [ABSTRACT FROM AUTHOR]

The use of drawn tungsten wire marked a breakthrough in electric lighting which led to a significant advancement in human society and technology. Nowadays, thermal light sources using tungsten filaments are being more and more replaced by semiconductor‐based light‐emitting diodes (LEDs). Despite the lower visibility of incandescent lamps in everyday life, new markets and applications for drawn tungsten wires are opening up, which makes this complex material a highly‐studied subject. One of these applications is the use of heavily drawn tungsten wires as high‐performance reinforcement fibers for new composites that can withstand the extreme environment present in a nuclear fusion reactor. The main advantage of tungsten wires for this class of composites is their ductility and high strength. The wires can be used to increase the high‐temperature strength of copper‐based heat sink materials as well as the fracture toughness of bulk tungsten considered for the use of highly loaded reactor wall components. These new applications for tungsten wire have also given new impetus to the study of their fundamental properties. [ABSTRACT FROM AUTHOR]

To investigate the problems of overload and excessive thermal insulation associated with building electrical fires caused by wires, a theoretical model of wire heat transfer is established, and the pyrolysis and combustion phenomena of the insulation layer are analyzed. The results showed that the temperature evolution of the wire underwent three stages: constant temperature, insulation heating, and high‐temperature pyrolysis. The insulation layer experiences bulging, exhausting, carbonization, dripping, and burning in sequence, and insulation layer dripping requires at least 160 A of current. As the current increases, the temperature increase rate of the wire increases gradually, and the fusing time of the wire gradually decreases. Under the same current, 160°C is the turning point at which the temperature increases. The temperature increase rate of the copper wire is greater than that of the aluminum alloy wire, and the temperature increase rate of the bare wire is greater than that of the insulated wire. The fusing time of an aluminum alloy wire is less than that of a copper wire, and the fusing time of a bare wire is less than that of an insulated wire. The research results provide theoretical guidance for the prevention and investigation of building electrical fires. [ABSTRACT FROM AUTHOR]

Steel cords are a reinforcing phase of the rubber-steel-canvas composite, and their properties, including strength, depend on the quality of the wires. The novelty of the work is a multi-parameter analysis of the cord production process, which showed that there is a relationship between the rheological properties of the lubricating emulsion, the friction conditions and deformation of the brass coating, and the properties of the wires and their resistance to cracking when braiding into a steel cord. It was shown that the friction conditions depend on the wire temperature and the rheological properties of the emulsion. As the drawing speed increases, the emulsion viscosity improves. The grease reaches its optimum at a specific drawing speed depending on the type of emulsion and the type of wire. Further increases in drawing speed result in an increase in temperature at the material/tool interface. This leads to a decrease in the viscosity of the emulsion and the breakdown of the lubricant film in the contact zone. Inappropriate selection of wet drawing speed contributes to a decrease in plastic properties and a reduction in the number of twists and bends of the wire, which leads not only to wire breakage at the stage of cord braiding but also to its premature breaking during the tensile test. [ABSTRACT FROM AUTHOR]

Tungsten carbides are important materials used in ceramic cements, machining tools, catalysts, sensors, and for hydrogen generation. Bulk W–C structures are highly complex; fundamental fully carburized WC and semi-carburized W 2 C are accompanied by structural transitions depending on the composition and temperature. The relationship between the structures, compositions, and temperatures is summarized in the W–C phase diagram. However, the high-temperature, stable, and single-crystalline nanoparticles related to the WC 1-x and W 2 C phases formed via energetic reactions accompanied by rapid cooling rates are not easy to determine considering the bulk phase diagram, and lead to fundamental questions regarding the origin of the nanophases. In this study, we propose a draft for the W–C nanophase diagram composed of the surface and gas-phase WC, WC 1-x , and W 2 C nanophases according to the composition and temperature. The model undergoes the process of a vapor–nanoliquid–nanophase starting from the gas-phase nucleation induced by an extremely high-temperature electrical explosion. In addition, the high-temperature reactivity and quenched nanophase, including its unique nanostructure, are related to the post-melt rheology, physical morphology, and steric hindrance of the solid matrix during an electrical explosion. [ABSTRACT FROM AUTHOR]

A computational study of the inception of positive wire-cylinder corona discharges in low-pressure air in crossed electric and magnetic fields is performed. The inception voltages are calculated for a wide range of gas densities, wire radii, and applied magnetic fields. Conditions are considered when the reduced electric fields at wire electrodes reach extremely high values of about 10 kTd. An expression applicable at such strong fields for the ionization coefficient, which is a key parameter of the corona inception model, is presented against the values of electric and magnetic fields. Calculated inception voltages agree with a large quantity of available experimental data on low-pressure positive corona discharges, obtained both with and without the application of magnetic fields. The calculation results describe specific details of the non-monotonous dependence of the inception voltages on the magnetic field values, similar to those obtained in experiments. [ABSTRACT FROM AUTHOR]

This article presents the results of research on a new combined process involving multi-cycle wire-drawing and subsequent cryogenic cooling after each deformation stage. For theoretical research, modeling in the Deform software was performed. The analysis of temperature fields and the martensitic component in all models showed that for both considered thicknesses, the most effective option is a low deformation velocity and the conduct of a process without heating. The least effective option is to use an increased thickness of the workpiece at an increased deformation velocity and the conduct of a process without of heating to ambient temperature, which acts as a local cooling of the axial zone of the workpiece with an increase in the workpiece thickness. An analysis of laboratory studies on this combined process revealed that in the absence of intermediate heating of a wire between deformation cycles, 100% martensite is formed in the structure. However, if intermediate heating to 20 °C between deformation cycles is carried out, a gradient distribution of martensite can be obtained. And, since the wire has a circular cross-section, in all cases, martensite is distributed symmetrically about the center of the workpiece. [ABSTRACT FROM AUTHOR]

One of the promising and little-studied methods for obtaining an ultrafine-grained structure and enhanced mechanical properties is the so-called cryogenic deformation - deformation at temperatures below 120K. It is assumed that low deformation temperatures suppress recovery processes, thus contributing to the accumulation of an extremely high dislocation density and increase internal stresses, as well as activate deformation twinning, which together will accelerate grain refinement. In this regard, in this work, we studied the drawing of steel wire under cryogenic cooling in liquid nitrogen. The results of the laboratory experiment show that the application of cryogenic deformation treatment after wire drawing improves mechanical properties compared to conventional wire drawing. In this case, after two cycles of deformation, the relative contraction after stretching decreases by 8 %, the ultimate strength increases by 40 %, and the conditional yield strength by 26 %. The results show that the deformation conditions during cryogenic drawing are an additional factor for the realization of structural resources of steel wire physical and mechanical properties optimizing. [ABSTRACT FROM AUTHOR]

This work is a study aimed at optimizing the process of superarc metallization, with a focus on the effect of voltage on the properties of the spraying coatings. In this work, 30HGSA grade steel wire was used for the coating of 45 steel, widely used in mechanical engineering. The use of supersonic arc metallizer SX-600 allowed to obtain coatings at different voltages (32 V, 38 V and 44 V) and the same current strength. Various metallization process parameters such as material feed rate, voltage, current, distance and nozzle geometry are discussed in this paper. Using various analytical techniques including X-ray diffraction analysis, microscopy, microhardness and corrosion resistance tests, the qualities of the coatings were evaluated. Particular attention was paid to analyzing the phase composition of the coatings, porosity, substrate bond strength and tribological characteristics. It was found that the voltage during the supersonic arc metallization process has a significant effect on these characteristics. The selected optimum voltage allows to obtain dense and homogeneous coatings with improved performance properties. The results of the study revealed that the best physical and mechanical properties were exhibited by the sample processed at 38 V, which showed lower porosity and improved strength characteristics compared to the other samples. These findings can be used to improve manufacturing processes in industries such as automotive and mechanical engineering, where restoration and improved performance of worn parts is required. [ABSTRACT FROM AUTHOR]

Purpose of Review: The radiologist's role is integral in the diagnosis and preoperative management of breast cancer patients. The pre-surgical localization of non-palpable breast masses has been achieved using wire-guided devices for decades. Despite being widely regarded as the gold standard for their proven effectiveness and cost-effectiveness, wire-guided localization (WGL) techniques have been associated with several drawbacks. These drawbacks include patient discomfort, the possibility of displacement prior to resection, and the requirement for placement on the same day as surgery. This review aims to outline non-wire localization (NWL) devices and techniques available as alternatives to WGL, including their benefits and limitations. Recent Findings: No significant differences have been found with surgical outcomes between WGL and NWL. Between 2013 and 2018, the use of WGL has decreased from 75 to 32%, and the use of radioactive seed localization has increased from 16 to 61%. Summary: A multidisciplinary approach that considers the patient, provider, and healthcare institution and current research on surgical outcomes must be utilized to determine the optimal course of action for preoperative localization of non-palpable breast masses. [ABSTRACT FROM AUTHOR]

A position-sensitive detector, which is a neutron target at the same time, is presented to study the interaction reactions of fast neutrons of above 1 MeV with light nuclei, in particular, with the 10B nucleus. It contains two boron-10 layers and a system of wire electrodes to identify secondary nuclei, in particular 3H and 4He, and to determine energy loss and departure angle. Thus the neutron energy can be determined. [ABSTRACT FROM AUTHOR]

New technology is presented in the work for copper wire processing. This technology consists of deforming wire in a rotating equal-channel stepped die and subsequent drawing. The die rotates around the axis of the wire and creates stress due to equal-channel angular broaching and twisting within the die. Results of a laboratory experiment show that after deformation an ultrafine grained graded microstructure with a high content of high-angle grain boundaries is obtained. Tensile strength of deformed copper wire in comparison with undeformed wire increases from 302 to 635 MPa, and yield strength increases from 196 to 406 MPa. [ABSTRACT FROM AUTHOR]

A submersible annular linear induction pump (ALIP) design with an outer diameter of 66.8 mm with appropriate materials is developed for circulating molten lead and alkali liquid metals of sodium and sodium-potassium-78 (NaK-78) alloy in test loops at temperatures up to 500°C. These loops investigate the compatibility of these liquid coolants with nuclear fuel and structure materials to support the development of advanced, Generation IV nuclear reactors. The present ALIP, which employs high-temperature ceramic-insulated coil wires and Hiperco-50 center core and stators, fits in Type 316 stainless steel, 2.5-in. standard schedule 5 pipe. This pipe, considered for the riser tube of the Versatile Test Reactor (VTR) in-pile test cartridge loop, has an inner diameter of 68.8 mm permitting 1.0-mm radial clearance for the present ALIP. An improved equivalent circuit model (ECM) is developed to analyze the performance of the present ALIP design. The accuracy of the model predictions is successfully validated using reported experimental measurements by other investigators for a low liquid sodium flow ALIP at 200°C and 330°C. The improved ECM calculates the performance characteristics of the present ALIP design and investigates the effects of varying the terminal voltage, current frequency, winding wire diameter, center core length, width of the liquid flow annulus, and working fluid properties and temperature on the pump operation. For circulating molten lead, the calculated peak efficiency of the present ALIP design of 6.7% occurs at a flow rate of 9.5 kg/s and pumping pressure of 263 kPa. The calculated peak efficiency for circulating liquid sodium is much higher, 26.3%, and occurs at a lower flow rate of 2.2 kg/s but a higher pumping pressure of 364 kPa. The calculated peak efficiency for circulating NaK-78 (23%) is lower than for sodium and occurs at a lower flow rate and pumping pressure of 1.9 kg/s and 310 kPa, respectively. [ABSTRACT FROM AUTHOR]

The article focuses on the impact of rising gold wire costs on semiconductor packaging and the advancements in gold wire bonding technology. Topics include the challenges of wire-lifting and surface degradation, the development of micro-tensile tests to assess thermomechanical properties, and the use of finite element methods combined with optimization tools to improve thermal reliability in extreme environments.

In this work, wire arc additive manufactured (WAAM-ed) Inconel 617- and 625-wmo grade alloys are characterized in detail for the type and distribution of precipitates in as-built and heat-treated conditions. The analyses are carried out near (~1 mm) and away (~10 mm) from the substrate along the build direction to investigate the effect of the substrate on the nature of precipitate formation. For each analysis location, morphological and chemical information of at least 400 precipitate features was identified and classified using stoichiometric analysis of SEM-EDS data combined with feature analytics. Carbides and carbonitrides are present in both Inconel 600 series alloys but Laves phase precipitates are identified only in the case of Inconel 625 wmo alloy. It is observed that the nature of precipitates size distribution is not altered significantly when compared between the two analysed locations for a particular grade. Furthermore, Laves phase precipitates closer to the substrate (1 mm) are richer in iron because of the effect of mild steel substrate on precipitation characteristics in Inconel 625 alloy. Our novel characterization approach will pave the way for comparing the microstructures of additively manufactured samples printed using different process parameters and variations. [ABSTRACT FROM AUTHOR]

10CrNi3Mo alloy steel has the characteristics of high hardness and wear resistance, and is widely used in aircraft and spacecraft, shipbuilding and so on. However, its conventional processing method has high tool loss. Wire Electrical Discharge Machining (WEDM) technology is based on electrode pulse discharge to corrode materials. There is no direct contact between the tool and the workpiece, so it is suitable for processing materials with complex shapes, such as high hardness and high brittleness. The focus of this study is to investigate the effects of different electrical parameters such as pulse width, pulse gap, current, and wire feeding speed on the recast layer thickness (RCL) and surface roughness (SR) of 10CrNi3Mo alloy steel processed by wire discharge machining using orthogonal experiments. The gray correlation method was used to optimize the above two process indicators, and seeking optimal processing parameters. The optimized recast layer thickness was 8.65 μ m. The surface roughness is 1.932 μ m. Achieve expected goals. [ABSTRACT FROM AUTHOR]

Strength and electrical conductivity (EC) are key properties for heat-resistant Al-Zr-based alloy wires used as overhead transmission lines. Developing high-strength conductors with EC over 61.0% IACS has been a long-standing issue for heat-resistant Al conductive wires. In this work, a new design idea involving the coupling design of deformation and ageing was innovatively proposed to produce ultra-heat-resistant Al-0.2Zr-0.06Sc wires. The desired combination of high strength (195 ± 2 MPa) and good EC (61.2% IACS) was successfully achieved without annealing treatment. The strength residual rate of cold-drawn Al-0.2Zr-0.06Sc wire is as high as 94.0% after heat exposure of 280°C/1 h. [ABSTRACT FROM AUTHOR]

Incorporating silver wires into propellant has emerged as a highly effective strategy for enhancing propellant burning rates, a technique extensively deployed in the construction of numerous fielded sounding rockets and tactical missiles. Our research, employing a multi-faceted approach encompassing thermogravimetric-differential scanning calorimetry measurements (TG-DSC), combustion diagnoses, burning rate tests, and meticulous collection of condensed combustion products, sought to elucidate how variations in silver wire quantity and winding configuration impact the combustion properties of propellants. Our findings underscore the remarkable efficacy of double tightly twisted silver wire in significantly boosting propellant burning rates under ambient conditions. Moreover, at lower temperatures, the reduced gap between the propellant and silver wire further magnifies the influence of silver wire on burning rates. However, it is noteworthy that the relationship between burning speed and combustion efficiency is not deterministic. While a smaller cone angle of the burning surface contributes to heightened burning rates, it concurrently exacerbates the polymerization effect of vapor phase aluminum particles, consequently diminishing propellant combustion efficiency. Conversely, propellants configured with sparsely twinned silver wires exhibit notable enhancements in combustion efficiency, despite a less pronounced impact on the burning rate attributed to the larger cone angle of the burning surface. Remarkably, these trends persist at lower temperatures. Based on the principle of heat transfer balance, a theoretical model for the combustion of propellants with wire inserts is developed. The reliability of this theoretical model is validated through a comparison of calculated values with experimental data. Our research outcomes carry significant implications for guiding the application and advancement of the silver wire method in solid propellants for solid rocket motors, offering valuable insights to inform future research and development endeavors in this domain. [ABSTRACT FROM AUTHOR]

Using computer simulations, we have studied the percolation and the electrical conductance of two-dimensional, random percolating networks of curved, zero-width metallic nanowires. We mimicked the curved nanowires using circular arcs. The percolation threshold decreased as the aspect ratio of the arcs increased. Comparison with published data on the percolation threshold of symmetric quadratic Bézier curves suggests that when the percolation of slightly curved wires is simulated, the particular choice of curve to mimic the shape of real-world wires is of little importance. Considering the electrical properties, we took into account both the nanowire resistance per unit length and the junction (nanowire/nanowire contact) resistance. Using mean-field approximation (MFA), we derived the total electrical conductance of nanowire-based networks as a function of their geometrical and physical parameters. The MFA predictions have been confirmed by our Monte Carlo numerical simulations. For our random homogeneous and isotropic systems of conductive curved wires, the electric conductance decreased as the wire shape changed from a stick to a ring when the wire length remained fixed. [ABSTRACT FROM AUTHOR]

The diamagnetic susceptibility and binding energy (BE) of a hydrogenic donor confined in a GaAs/AlGaAs QWW were theoretically studied in this paper under the influences of the applied laser field, QWW geometry, and non-parabolicity using variation technique combined with effective mass approximation. In the first part, the diamagnetic susceptibility and BE of the donor at the ground state are studied as a function of the size of the QWW, geometry, and applied laser field. The results reveal that changing the geometry of QWW enhances the quantum confinement effects. However, increasing the laser field reduces the BE by adding screening effects to the Coulomb interactions. Further, the diamagnetic susceptibility is available with the stability information about the carrier–parent donor system based on the mean square separation between them. It also demonstrates that susceptibility may remain stable regardless of the change in geometry and applied laser field. Thus, the diamagnetic behavior can serve as a better tool to evaluate the stability and Mott transition of donors in QWW. In the second section, the consequences of laser field and geometry on the SMT of confined donors in QWW have been studied. It is observed that the BE of donors remains constant until N ∼ 1 0 1 5  cm − 1 beyond which it starts to decrease gradually and vanishes exactly at critical concentration ( N c). However, the diamagnetic susceptibility of the donor has remained constant until reaching N c , beyond which it turned into a drastic fall, which manifested the SMT in the system. The current work is expected to add a few noteworthy points to the SMT phenomena in nanostructures. [ABSTRACT FROM AUTHOR]

A novel arc additive manufacturing process using cable-type welding wire (CWW) and ER1070 Al wire was used for the first time to successfully fabricate Alx-Co-Cr-Ni (x = 0–29) high entropy alloy with a variation in Al concentration along the building direction. Microstructure and mechanical properties of the in-situ prepared Alx-Co-Cr-Ni compositionally graded high-entropy alloys were investigated. Results indicate that a continuous transition from a single-phase FCC to FCC + B2 dual-phase was achieved, benefiting from the special structure of the CWW and repeating thermal cycles during deposition. With the increase in Al content, microstructure changed from columnar grains to dendrites, and Al-Ni rich B2 phase precipitated in the inter-dendritic region. A lamellar eutectic microstructure was observed in the interface of Al-19 HEA and Al-29 HEA. The mechanical properties of the alloy showed a gradient significant change with increase in Al concentration, with (i) microhardness increasing from 170 to 450 HV (ii) yield strength increasing from 257 to 640 MPa (iii) change in fracture mode from ductile (Al-0) to brittle (Al-29) due to excess B2 phase precipitation. From microstructure-properties relationship, the significant enhancement in mechanical properties along the build direction is identified to be due to solid solution strengthening and second phase strengthening brought forth by the presence of compositionally gradient Al. [ABSTRACT FROM AUTHOR]

Wire icing seriously threatens the safety and reliability of power systems. Strengthening the simulation study of icing thickness is crucial for disaster prevention and mitigation, as well as the adjustment of power system operation strategies. The meteorological elements, including air temperature, precipitation and wind speed, are the key factors affecting wire icing. In this study, the meteorological elements related to icing thickness are obtained by numerical models, and the relationship between these elements and icing thickness observations is established to develop a model for simulating icing thickness. The model is applied to study typical icing in Yunnan Province, China. The results indicate that the deviation of the simulated icing thickness is about 2 mm, smaller than that from the traditional model. Batch experiments demonstrate that the new model developed in this research is applicable to the vast majority of 238 observation stations in Yunnan Province for icing thickness simulation, and the method can yield lower simulation deviations. [ABSTRACT FROM AUTHOR]