Distribution Of Secondary Particles Research Articles

개선된 고상 합성법을 통한 LiNi 0.5 Mn 1.5 O 4 양극재 연구

In this study, LiNi 0.5 Mn 1.5 O 4 was synthesized from various raw materials, including NiO, Ni 2 O 3 , MnO 2 , and Mn 3 O 4 . An improved solid-phase synthesis method was then used to reduce impurities through uniform mixing via bead milling and to achieve a consistent secondary particle shape and distribution through spray drying. The LiNi 0.5 Mn 1.5 O 4 was obtained by selecting materials optimized for rate capability and by applying an improved synthesis process. X-ray diffraction and scanning electron microscopy analyses confirmed that LiNi 0.5 Mn 1.5 O 4 successfully synthesized primary and secondary particles. This result showed that LiNi 0.5 Mn 1.5 O 4 , when subjected to an improved solid-phase synthesis, reduces production costs ,enhances its commercial value, and can be applied to lithium-ion secondary batteries to achieve high energy density and high voltage. In short, LiNi 0.5 Mn 1.5 O 4 can be used as an efficient energy storage material.

Tailoring the formability and planar anisotropy of Al-Mg-Si-Cu-Zn alloys via cross hot rolling and two-stage cold rolling

Al-Mg-Si-(Cu) alloys have shown great potential in responding to the growing demand for automotive lightweight, but the limited formability and high planar anisotropy have always hindered their application. The present study designs a novel method for simultaneously improving the formability and planar anisotropy of Al-Mg-Si-Cu-Zn alloys by coupling cross hot rolling and two-stage cold rolling. The results have shown that the multi-scale distribution of secondary particles and strong Brass{011}<112> and S{123}<634> texture are induced by the designed cross hot rolling process, which weakens the recrystallization texture after solution treatment, especially Cube{001}<100> orientation. Meanwhile, the designed two-stage cold rolling process (intermediate cold rolling process with high reduction + final cold rolling process with low reduction) promotes the precipitation of unstable precipitates (Mg2Si and Q phase), and inhibits the formation of Copper{112}<111> orientation, which further weakens the recrystallization texture and results in the dispersion distribution of recrystallization texture. Accordingly, the formability and planar anisotropy of the Al-Mg-Si-Cu-Zn alloy are simultaneously improved without strength loss by coupling the designed cross hot rolling with two-stage cold rolling, and the influence mechanism of texture on r value has been analyzed by Visco-Plastic Self-Consistent (VPSC) model.

Fractural analysis, microstructural, mechanical and tribological behaviour of vanadium trioxide-reinforced copper metal matrix composite by ultrasonic-assisted stir casting technique

In this work, pure copper is reinforced with vanadium trioxide (V2O3) at various weight percentages, such as Cu–0.5V2O3, Cu–1V2O3, Cu–1.5V2O3, and Cu–2V2O3. This copper metal matrix composite (CMMC) with primary copper element and secondary V2O3 is fabricated through an ultrasonic-assisted stir casting technique. The uniform distribution of secondary particles is achieved using ultrasonic waves generated by the probe and mechanical stirrer. The characterization of developed CMMC is done by X-ray diffraction and energy-dispersive X-ray spectroscopy. The samples are subjected to grain measurement using an optical microscope, which showed the relationship between grain size and enhancement of mechanical properties. The fabricated samples are also subjected to mechanical testing to determine their tensile strength, ultimate strength, Vickers hardness and impact strength. Fractography is also done by using a scanning electron microscope to understand the mechanism for the failure of tensile specimens. Dry sliding wear behaviour is also carried out to determine the wear resistance of CMMC. The results of numerous experiments showed that the grain size of CMMC improved with V2O3 addition. The increased strength-to-weight ratio leads to obtaining better properties at low cost. The enhancement in wear behaviour and mechanical properties of CMMC also paves the way for a newly developed material with V2O3 as secondary reinforcement along with copper as the primary element to be used in various applications.

Enhanced in-vitro biodegradation, bioactivity, and mechanical properties of Mg-based biocomposite via addition of calcium-silicate-based bioceramic through friction stir processing as resorbable temporary bone implant

Bioabsorbable Mg and alloys have been used as metallic biomaterials for orthopedic implant applications due to their similar mechanical properties to human natural bone. High biodegradation rate is the main reason for limiting clinical applications of Mg and alloys in biological media. In order to achieve long-lasting bio applications of bioabsorbable WE43 Mg alloy, it is necessary to improve strength and bioactivity and control biodegradation rate of this material. In this study, Mg-based biocomposites are produced using friction stir processing (FSP) by addition of wollastonite (CaSiO3) calcium-silicate-based bioactive reinforcing particle into Mg matrix. The results showed that applied severe plastic deformation during FSP caused formation of ultra-fine grain structure with homogenous distribution of secondary phase particles, which resulted in a remarkable improvement of ductility, strength and load bearing capacity of FSPed Mg matrix. Also, biodegradation behavior of resulting biocomposite was evaluated using electrochemical methods and in-vitro immersion test in simulated body fluid (SBF) and phosphate-buffered saline (PBS) at 37.5 °C. The results revealed that processed bioabsorbable Mg alloy showed a lower biodegradation rate compared to monolithic Mg alloy. Furthermore, the presence of wollastonite bioceramic particles significantly enhanced strength and reduced biodegradation of the Mg-based biocomposite. Moreover, the addition of wollastonite bioceramic particles positively affected the bioactivity of Mg matrix by forming a cauliflower shaped bone-like hydroxyapatite layer on the surface after 28 days of immersion in SBF and stimulate bone tissue regeneration.

Investigation of microstructure, mechanical properties, and corrosion resistance of AZ91-Ca alloy after friction stir back extrusion

ABSTRACT The influence of friction stir back extrusion speed on microstructure evolution, mechanical properties, and corrosion resistance of AZ91-0.6 wt.% Ca alloy was investigated. The friction stir back extrusion was performed using a rotational speed of 800 rpm and extrusion speed of 20–80 mm/min. It was found that after friction stir back extrusion, coarse α-Mg dendrites with continuous secondary phase network at the grain boundary of the cast microstructure turned to equiaxed microstructure with uniform distribution of secondary phase particles. Increasing the extrusion speed from 20 to 60 mm/min decreased grain size from 26.1 ± 2.3 to 22.3 ± 1.9 μm. Although, with decreasing extrusion speed from 60 to 20 mm/min, the texture parameter of the basal and prismatic planes reduced, and the texture parameter of the pyramidal planes increased, a dominant texture was not formed in the extruded samples. The ultimate tensile strength value increased from 375.1 ± 7.45 MPa to 396.1 ± 11.31 MPa by increasing the extrusion speed from 20 to 60 mm/min. The yield strength, ultimate tensile strength, and corrosion resistance of the wires extruded by an extrusion speed of 60 mm/min and rotational speed of 800 rpm have increased by 71, 88, and 44%, respectively, compared to the as-cast base metal.

Study of longitudinal development of air showers in the knee energy range

Ground-based cosmic ray experiments detect cosmic ray mainly by measuring the longitudinal and lateral distribution of secondary particles produced in the extensive air shower (EAS). The EAS of cosmic ray in the knee energy region is simulated via CORSIKA software. Several simulation samples with different energy, composition and zenith angles were carried out to understand the longitudinal development of electron, muon and Cherenkov light in EAS. All the results presented were obtained assuming an observation plane at an altitude of 4400 m a.s.l. The differences of longitudinal development between electron and Cherenkov light were studied, and the reconstruction uncertainty of shower maximum for electron from Cherenkov light was estimated to be 10–15 g/cm2 for nuclei above 1 PeV. The performances of energy measurement and the composition discrimination ability based on longitudinal development were studied and compared with that from lateral distribution. It was found that number of electron per depth at its shower maximum has the smallest shower-to-shower fluctuations, but the shower-to-shower fluctuations of electron density measured at observation level was very close to it when the appropriate zenith angle was employed. The shower-to-shower fluctuations of shower maximum for electron is 50–55 g/cm2 for proton, and 20–25 g/cm2 for iron, but the composition discrimination ability between nuclei from muon density measured at observation level is much better than the shower maximum variable from longitudinal development. The hadronic model dependencies of the longitudinal development and lateral distribution were also discussed.

Transverse Momentum Distribution of Secondary Particles in High-Energy Collisions of Protons and Nuclei and the Possibility of Detecting Dark Matter Particles in the Spectra of Soft Photons

Transverse Momentum Distribution of Secondary Particles in High-Energy Collisions of Protons and Nuclei and the Possibility of Detecting Dark Matter Particles in the Spectra of Soft Photons

Effect of deep cryogenic treatment on the microstructural, mechanical and ballistic properties of AA7075-T6 aluminum alloy

The study focused on investigating the effect of Deep Cryogenic Treatment (DCT) on the mechanical and ballistic properties of AA7075-T6 aluminum alloy. The microstructure, microhardness, tensile strength, and impact strength of the Base Material (BM) and DCT-treated 7075 samples were analyzed through metallographic analysis and mechanical tests. The microstructure of the DCT-treated 7075 samples revealed fine grains and a distribution of secondary phase particles. The tensile strength, impact strength, and microhardness of DCT-treated samples increased by 7.41%, 4%, and 9.68%, respectively, compared to the BM samples. The fractography analysis of the tensile samples showed cleavage facets, microvoids, and dimples in both the samples. The ballistic behavior of the BM and DCT target plates were studied by impacting hard steel core projectiles at a velocity of 750 ± 10 m/s. The target plates failed due to petaling and ductile hole enlargement, and the depth of penetration (DOP) of the DCT target was less than that of the BM target, indicating a higher ballistic resistance. The post-ballistic microstructure examination of the target plates showed the formation of an Adiabatic Shear Band (ASB) without any cracks. It was concluded that the DCT treatment improved the mechanical and ballistic properties of the aluminum alloy due to grain refinement and high dislocation density.

Novel Ultrafine-Grain Mg-Gd/Nd-Y-Ca Alloys with an Increased Ignition Temperature.

Two novel ignition-resistant magnesium alloys, Mg-2Gd-2Y-1Ca and Mg-2Nd-1Y-1Ca, were prepared in the ultrafine-grain condition by equal channel angular pressing (ECAP). In addition, four commercial alloys-AZ31, AX41, AE42 and WE43-were prepared similarly as a reference. The microstructure, mechanical properties and ignition temperature were thoroughly investigated. Both novel alloys exhibited a mean grain size of ~1 µm and dense distribution of small secondary phase particles. The mechanical strength measured by the tensile deformation test showed that the novel alloys are much stronger (~290 MPa) than all commercial alloys except WE43. However, Ca segregation into the grain boundaries caused a significant decrease in ductility (<6%). The ignition temperature of the novel alloys (~950 °C) was considerably improved by the presence of Gd/Nd, Y and Ca. This study showed that both novel alloys exhibit high strength and high ignition temperature in the ultrafine-grain condition.

Microstructure Evolution, Constitutive Modelling, and Superplastic Forming of Experimental 6XXX-Type Alloys Processed with Different Thermomechanical Treatments.

This study focused on the microstructural analysis, superplasticity, modeling of superplastic deformation behavior, and superplastic forming tests of the Al-Mg-Si-Cu-based alloy modified with Fe, Ni, Sc, and Zr. The effect of the thermomechanical treatment with various proportions of hot/cold rolling degrees on the secondary particle distribution and deformation behavior was studied. The increase in hot rolling degree increased the homogeneity of the particle distribution in the aluminum-based solid solution that improved superplastic properties, providing an elongation of ~470-500% at increased strain rates of (0.5-1) × 10-2 s-1. A constitutive model based on Arrhenius and Beckofen equations was used to describe and predict the superplastic flow behavior of the alloy studied. Model complex-shaped parts were processed by superplastic forming at two strain rates. The proposed strain rate of 1 × 10-2 s-1 provided a low thickness variation and a high quality of the experimental parts. The residual cavitation after superplastic forming was also large at the low strain rate of 2 × 10-3 s-1 and significantly smaller at 1 × 10-2 s-1. Coarse Al9FeNi particles did not stimulate the cavitation process and were effective to provide the superplasticity of alloys studied at high strain rates, whereas cavities were predominately observed near coarse Mg2Si particles, which act as nucleation places for cavities during superplastic deformation and forming.

Effects of Thunderstorms Electric Field on the Lateral Distribution of Cosmic Ray Secondary Particles at LHAASO

Effects of Thunderstorms Electric Field on the Lateral Distribution of Cosmic Ray Secondary Particles at LHAASO

Sensitivity of secondary particle emission to hadronic physics models in GATE/Geant4 proton therapy simulations at 100 MeV

Introduction: Proton therapy simulations rely on Monte Carlo techniques, such as the GATE code based on the Geant4 toolkit, to predict dose distribution and secondary particle production. The accuracy of these simulations is heavily influenced by the chosen physics models. Methods: In this study, we analyzed three Geant4 hadronic physics models, BIC, BERT, and INCL++, by calculating the angular and energy distributions of secondary neutrons and gamma particles. We conducted GATE/Geant4 simulations on a water phantom irradiated with a 100 MeV proton beam. Results: Our investigation revealed notable differences in the angular and energy distributions of emitted particles among the three models. Conclusion: This study emphasizes the necessity of carefully selecting a hadronic physics model for GATE/Geant4 simulations in proton therapy.

Effects of Thunderstorms Electric Field on the Lateral Distribution of Cosmic Ray Secondary Particles at LHAASO

Effects of Thunderstorms Electric Field on the Lateral Distribution of Cosmic Ray Secondary Particles at LHAASO

Study of Pseudo-rapidity Distributions of Secondary Particles at High Energies

Study of Pseudo-rapidity Distributions of Secondary Particles at High Energies

Ultra-high energy cosmic rays with the Pierre Auger Observatory

In the era of multi-messenger astronomy, ultra-high energy cosmic rays offer the unique opportunity to investigate the nature of astrophysical sources and of particle interactions in an energy range far beyond that covered by current particle accelerators. The Pierre Auger Observatory, the world’s largest cosmic ray detector, combines in a hybrid design the information from fluorescence telescopes, observing the longitudinal profile of extensive air showers, with a surface array, measuring the lateral distributions of secondary particles at the ground. A review of selected results is presented, focusing on the measurements of energy spectrum and chemical composition and on the search for neutral primary particles. The future prospects will also be discussed in light of the extensive upgrade program being now implemented to further improve the Observatory potential.

Influence of Al3+ Doping on Dispersion and Suspension Stability of Nano CeO2 Particles

ABSRACT For achieving a uniform and stable suspension of CeO2 nanoparticles in aqueous medium, Al3+ was doped into the lattice of CeO2 by hydrothermal treatment. Although the doping will increase the probability of adhesion of primary particles with the size of 7 nm, it can effectively prevent the agglomeration between CeO2 particles, greatly improve the dispersion uniformity and suspension stability of particles, greatly narrow the particle size distribution of secondary particles, and make the degree of particle agglomeration controllable. Meantime, the UV absorption property of the product was improved and the absorption peak was red shifted after Al3+ doping.

Corrosion behavior of severely plastically deformed Mg and Mg alloys

Magnesium (Mg) alloys have several advantages, such as low density, high specific strength and biocompatibility. However, they also suffer weak points, such as high corrosion, low formability and easy ignition, which makes their applications limited. Many studies have been conducted to overcome these disadvantages and further improve the advantages of Mg alloys. Severe plastic deformation (SPD) is one of the most important techniques and has great effects on the microstructure refinement of Mg alloys and improvements in their strength and formability. Several researchers have studied the corrosion behavior of SPD-processed Mg alloys in recent decades. However, these studies have reported some controversial effects of SPD on the corrosion of Mg alloys, which makes the research roadmap ambiguous. Therefore, it is important to review the literature related to the corrosion properties of Mg alloys prepared by SPD and understand the mechanisms controlling their corrosion behavior. Effective grain refinement by SPD improves the corrosion properties of pure Mg and Mg alloys, but control of the processing conditions is a key factor for achieving this goal because texture, dislocation density, size and morphology of secondary phase also importantly affects the corrosion properties of Mg alloys. Reduced grain size in the fine grain-size range can decrease the corrosion rate due to the increased barrier effect of grain boundaries against corrosion and the formation of a stable passivation layer on the surface of fine grains. Basal texture reduces the corrosion rate because basal planes with the highest atomic planar density are more corrosion resistant than other planes. Increased dislocation density after SPD deteriorates the corrosion resistance of the interior grains and thus proper annealing after SPD is important. The fine and uniform distribution of secondary phase particles during SPD is important to minimize the micro-galvanic corrosion effect and retain small grains during annealing treatment for removing dislocations.

Transient Current Analysis of Silicon Carbide Neutron Detector Using SRIM and TCAD

Since neutrons are electrically neutral, the methods used to detect neutrons generally rely on secondary charged particles, which are produced by the interaction of neutrons and neutron conversion materials (such as <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sup> LiF, <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sup> B). In this report, the SRIM code has been used to analyze the ionization properties of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\alpha $ </tex-math></inline-formula> particles and <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> H particles traveling through the Silicon Carbide (SiC) diode, and subsequently, the final Bragg ionization distribution has been obtained. Next, according to the obtained ionization distribution of secondary particles, the linear energy transfer (LET) distribution of the secondary particles is extraced accurately. Finally, based on the distribution of LET, Technology Computer Aided Design (TCAD) simulations are utilized to analyze the transient current pulses of thin-film-coated and trench-type SiC diodes. In addition, the effects of particle energy and applied reverse bias on the output pulse characteristics of SiC diodes are also explored. Essentially, this paper augments the understanding of output response from SiC neutron detectors, and for trench-type detectors, the order of output current pulse amplitude decreases significantly and has a long-tail. Therefore, the trench-type detectors not only need a more advanced fabrication process but also require the design of dedicated readout electronics.

Specific development features of secondary gold mineralization in mature tailings of gold processing plants

The paper studies the development of secondary gold mineralization driven by the interaction of gold-bearing solutions with primary minerals in sulfide and oxidized ore processing tailings, as well as with secondary limonite formed during their long-term storage. Lowtemperature gas adsorption was used to establish that such tailings are characterized by high specific surface areas of up to 20 m2/g. Material surface area may play an important role in the processes of sorption and reduction. Using X-ray photoelectron spectroscopy, it has been established that secondary mineralization gold predominantly occurs in its elemental form, with a subordinate amount of the occluded ionic form of Au(I). It has been shown that Au(III) ions selectively precipitate from solutions at 25 &deg;C and pH 6.9&ndash;7.3 on pyrite, arsenopyrite, and limonite, forming individual metal particles of 30&ndash;1000 nm, as well as mineral aggregates of complex structure and composition, including oxidized antimony minerals, limonite, and nanodispersed gold. Gold precipitation on a mixture of hydrates of iron and manganese oxides was found in samples of oxidized ore processing tailings. The specific morphology and grain-size distribution of secondary gold particles on various carrier minerals and the composition of new formations have been studied. On the secondary limonite, containing calcite (up to 10 wt%) and quartz impurities, the gold particles are up to 500 nm and are uniformly distributed over the entire material surface. This is in contrast to the sulfide and oxidized ore processing tailings, where gold was selectively reduced on certain minerals. The paper considers the potential mechanisms of gold reduction on the surfaces of oxidized minerals.The work patially was carried out within the framework of the state&nbsp;assignment of the Institute of Chemistry and Chemical Technology&nbsp;of the Siberian Branch of the Russian Academy of Sciences (project&nbsp;No. 0287-2021-0014) using the equipment of the Federal Research&nbsp;Center &laquo;Krasnoyarsk Science Center of the Siberian Branch of the&nbsp;Russian Academy of Sciences&raquo;.

Angular dependence of proton-induced single event transient in silicon-germanium heterojunction bipolar transistors

We investigate the angular dependence of proton-induced single event transient (SET) in silicon-germanium heterojunction bipolar transistors. Experimental results show that the overall SET cross section is almost independent of proton incident angle. However, the proportion of SET events with long duration and high integral charge collection grows significantly with the increasing angle. Monte Carlo simulations demonstrate that the integral cross section of proton incident events with high ionizing energy deposition in the sensitive volume tends to be higher at larger incident angles, which is associated with the angular distribution of proton-induced secondary particles and the geometry of sensitive volume.