Subatomic Research Articles

Radioactivation analysis of a concrete wall in a high-energy electron accelerator facility

ABSTRACT The high-energy electron accelerator facilities for free-electron laser (FEL) generators at Osaka University have been in operation since 1994. The main operations of the accelerators almost ended in 2001. Therefore, decommissioning of the facility has been considered, although there is a problem with radioactive materials. In addition to the activation of the accelerator body, activation of the building is a serious problem. In this study, the radioactivation of a concrete wall in an accelerator room was investigated. Core samples of the concrete wall were collected at certain positions, and their radionuclides were determined using gamma-ray spectrometry. Gamma-ray spectrometry revealed that the major radionuclides were 22Na, 60Co, and 152Eu. The amount of 55Fe was analyzed using liquid scintillation counting. The radioactivity estimated using the nuclear particle transport simulation code was approximately consistent with the results of the radioactivity measurements for 22Na, 55Fe, 60Co, and 152Eu. The amount of 3H was measured by 3H sampling and liquid scintillation counting. The 3H amount was found to be considerably smaller than the amount estimated using the simulation code probability, owing to diffusion in concrete. These results reveal the radioactivity issues in the facility and are expected to aid in its decommissioning.

Quantum food and nutrition: Subatomic approaches to nourishment for health and well-being.

Nutrition science has been represented as biomedical, environmental, societal and economic field, but quantum biology is sidestepped, thereby obscuring cognate problems and solutions. We are generally nourished for health, optimal well-being, longevity and personal security through sustainable livelihoods. Our nourish-ments include not only food and energy but also light from the sun, the firmament and the earth itself, along with information transmitted in subatomic particles and electromagnetic wave forms. We propose 'quantum nutrition' as an approach to reconcile quantum phenomena with nutritional biology. Appreciating quantum nutrition and recognizing its potential applications will provide opportunities for future health and well-being and for planetary habitability.

Convolutional neural network-based neutron and gamma discrimination in EJ-276 for low-energy detection

Organic scintillators are important in advancing nuclear detection and particle physics experiments. Achieving a high signal-to-noise ratio necessitates efficient pulse shape discrimination techniques to accurately distinguish between neutrons, gamma rays, and other particles within scintillator detectors. Although traditional charge comparison methods perform adequately for ∼MeVee particles, their efficacy is significantly reduced in the lower energy region (<200 keVee). This paper introduces a particle identification method that harnesses the power of a convolutional neural network. We focused on the convolutional neural network's exceptional ability to discriminate between neutrons and gamma rays in the low-energy spectrum, utilizing a setup comprising a plastic scintillator EJ-276 and Silicon photomultiplier readout. Our findings reveal remarkable accuracies of 97.3% and 98.6% in the 0 ∼ 100 keVee and 100 ∼ 200 keVee energy ranges, respectively. These results represent substantial improvements of 13.8% and 4.25% over conventional methods. The enhanced discrimination power of the convolutional neural network method opens new frontiers for the application of organic scintillation detectors in low-energy rare event searches, including dark matter and neutrino detection.

The Emergence of Quantum Mechanics from General Relativity Electromagnetism and Charge Quantization

Based on the concept of the Big Bang of the universe being governed by the principles of Minimization of Action and Minimization of rate of Entropy production in a the Very Early Universe, where the expansion of Spacetime was superluminal, both QM (Quantum Mechanics) and electrodynamics can be seen to be emergent rather than foundational with both being a consequence of electric charge quantization and electromagnetism in an expanding spacetime. Postulating the appearance of the “Electrically Entangled” electron charge quanta, which are identified as 5th dimensional vectors in a Kaluza-Klein mathematical framework, both plus and minus, at very Early times in the Big Bang, plus the existence of electromagnetic fields around those charges, the superluminal expansion of spacetime prevents electrodynamics and thus EM radiation. This epoch is postulated to end with the formation of the proton in the Hadron Epoch, with its three quarks forming, with the electron, a Minkowski four vector, and the highly entropic dynamics of the quarks within the proton giving rise to entropy in the EM field under cosmic isothermal conditions with a temperature defined by Electrodynamics of the quarks interior to the proton rather than electrodynamic scattering between widely separated subatomic particles. The appearance of a larger unit of action h, thus mirrors the appearance of a larger unit of stable rest mass, the proton. This correlation is confirmed by the central place of the proton/electron mass ratio in the highly accurate formula derived for α. The emergent character of the quanta of action is suggested to explain the unfeasibility of quantization of GR (General Relativity) to higher orders and with GR and EM with charge quantization being the foundation on which QM is built.

High Entropy Fine-Tuning Achieves Fast Li+ Kinetics in High-Performance Co-Free High-Ni Layered Cathodes.

Co-free high-Ni layered cathode materials LiNixMeyO2 (Me = Mn, Mg, Al, etc.) are a key part of the next-generation high-energy lithium-ion batteries (LIBs) due to their high specific capacity and low cost. However, the hindered Li+ kinetics and the high reactivity of Ni4+ result in poor rate performance and unsatisfied cycling stability. This work designs a promising strategy for designing a high-performance high-entropy doping Co-free high-Ni layered cathode LiNi0.9Mn0.03Mg0.02Ta0.02Mo0.02Na0.01O2 (HE-Ni90-1.557) by elemental screening and compositional fine-tuning. Compositional fine-tuning optimizes the synergistic relationship between the high-entropy dopant elements, thereby significantly suppresses the kinetic hysteresis induced by Li+/Ni2+ mixing. The pillar effect significantly enhances the diffusion kinetics of Li+ at the high state of charge (SOC). Meanwhile, the high-entropy fine-tuning significantly postpones the H2-H3 phase transition and reduces the dissolution of transition metals and the loss of lattice oxygen in the cathodes. Consequently, the diffusion kinetics of Li+ at the atomic and electrode particle scales are significantly enhanced. The HE-Ni90-1.557 cathode exhibits an initial capacity of 225.1 mAh g-1 at 0.2 C and a full cell with a high capacity retention of 83.1% after 1500 cycles at 3C. This work provides a promising avenue for commercializing Co-free high-Ni cathodes for next-generation LIBs.

The border effect in diamond microdosimeters and its impact on hadron therapy applications

Objective.The increasing interest in hadron therapy has heightened the need for accurate and reliable methods to assess radiation quality and the biological effectiveness of particles used in treatment. Microdosimetry has emerged as a key tool for this, demonstrating its potential, reliability, and suitability. In this context, solid-state microdosimeters offer technological advantages over traditional tissue-equivalent proportional counters, and recent advancements have further improved their performance and reliability. However, one critical challenge in solid-state microdosimetry is the so-called 'border effect', which can impact measurement accuracy.Approach.In this study, the border effect in diamond microdosimeters was thoroughly studied using ion beam induced charge analysis. The research, relying on experiments conducted at the Surrey Ion Beam Centre, developed an effective method to characterise and quantify the border effect. Geant4 Monte Carlo simulations were also employed to assess the impact of the border effect under typical proton therapy conditions.Main results. The border effect in diamond microdosimeter was characterised and studied as a function of detector thickness, particle atomic number and particle range. A border effect model was developed and validated to reproduce the border effect in Monte Carlo simulations. The results of its application to the microdosimetry of a proton beam at different depths in water showed potential significant variations of up to 40% iny¯Fand 20% iny¯Dvalues.Significance.The results of this work highlight the importance of accurately characterising the border effect and encouraging further research to mitigate its influence on microdosimetry measurements.

Determination of the degree of sulfonation in cross-linked and non-cross-linked Poly(ether ether ketone) using different analytical techniques.

The degree of sulfonation (DS) is a key property of sulfonated polymers, as it significantly influences their swelling behaviour, conductivity and mechanical properties. Accurately determining the DS is essential for optimizing these materials for various applications. In this work, the DS of sulfonated poly (ether ether ketone) (SPEEK) was evaluated using a combination of analytical techniques, including titration, back titration, Fourier Transform Infrared (FTIR), Ultra-Violet (UV) and proton nuclear magnetic resonance (1H NMR) spectroscopies, Thermogravimetric analysis (TGA), Rutherford backscattering (RBS) and particle induced X-ray emission (PIXE) analysis. Both non-cross-linked and cross-linked SPEEK were examined to assess the advantages and limitations of these methods. Classical approaches, such as titration and back titration are suitable for all sulfonated samples; however, they are limited by challenges like the extended time required for neutralization reaction due to hydrogen bonding between sulfonic acid groups. In contrast, molecular spectroscopic methods particularly UV and 1H NMR spectroscopy, are more efficient for soluble samples. 1H NMR spectroscopy is especially accurate, though it necessities additional steps, such as determining T1 relaxation times to ensure complete magnetization recovery. FTIR spectroscopy emerges as a versatile and effective method for DS determination across all samples types, particularly when enhanced with ATR accessories and calibrated with 1H NMR data. Combining with two-dimensional correlation spectroscopic analysis further improves its reliability.

Structural basis of 5' splice site recognition by the minor spliceosome.

The minor spliceosome catalyzes excision of U12-dependent introns from precursors of eukaryotic messenger RNAs (pre-mRNAs). This process is critical for many cellular functions, but the underlying molecular mechanisms remain elusive. Here, we report a cryoelectron microscopy (cryo-EM) reconstruction of the 13-subunit human U11 small nuclear ribonucleoprotein particle (snRNP) complex in apo and substrate-bound forms, revealing the architecture of the U11 small nuclear RNA (snRNA), five minor spliceosome-specific factors, and the mechanism of the U12-type 5' splice site (5'SS) recognition. SNRNP25 and SNRNP35 specifically recognize U11 snRNA, while PDCD7 bridges SNRNP25 and SNRNP48, located at the distal ends of the particle. SNRNP48 and ZMAT5 are positioned near the 5' end of U11 snRNA and stabilize binding of the incoming 5'SS. Recognition of the U12-type 5'SS is achieved through base-pairing to the 5' end of the U11 snRNA and unexpected, non-canonical base-triple interactions with the U11 snRNA stem-loop 3. Our structures provide mechanistic insights into U12-dependent intron recognition and the evolution of the splicing machinery.

Existence and stability results for time-fractional Schrödinger equations Related to the harmonic oscillator

Abstract The implications of the Schrödinger equation is profound, revealing the wave-particle duality of matter, the concept of superposition, and the probabilistic nature of quantum measurements. Its solutions provide critical insights into the behavior of atoms, molecules, and subatomic particles, forming the foundation for much of modern physics and technology. This article is concerned with the existence and uniqueness of solutions for Schrödinger equation that involve fractional differential equations using the Caputo method with initial conditions, as well as exploring the Hyers-Ulam stability of the Schrödinger equation was investigated when the relevant system has a potential well of finite depth using a fixed-point approach. Finally, we present the graphical representation for the Schrödinger equation related to the harmonic oscillator.

Finding Dark Matter

This article investigates the enigmatic nature of dark matter, hypothesized to make up approximately 70% of the universe's total mass. Despite decades of research using state-of-the-art equipment such as the Large Underground Xenon (LUX) experiment, direct detection of dark matter remains elusive, leading to skepticism and calls to revise existing theoretical frameworks. Rather than abandoning the search, this paper proposes an alternative investigative approach inspired by detective methodologies: using indirect evidence to infer the characteristics of an unseen phenomenon. The hypothesis presented posits that dark matter is a dual-component system comprising a superfluid-like medium and spherical particles. This system facilitates wave propagation, reduces cosmic friction, and supports the dynamic structure of the universe. Drawing analogies from structural engineering and mechanics, the article conceptualizes dark matter as a network of interconnected tunnels that allow the seamless movement of subatomic particles and waves. Finally, the study underscores the continued importance of dark matter research, asserting its pivotal role in explaining cosmic phenomena and the structure of the universe.

Astrophysical study of dust collision using molecular dynamics method: an overview

Abstract Understanding dust collisions in astrophysical environments is essential for comprehending the formation and evolution of cosmic structures, such as planetary rings and interstellar clouds. This article reviews briefly studies on dust collision dynamics using the molecular dynamics (MD) method during the early stages of protoplanet formation. By simulating interactions at the atomic and molecular levels, researchers have actively explored the fundamental processes governing dust aggregation and fragmentation. This method incorporates essential aspects such as surface energy and viscoelastic behavior through interaction potentials between atomic particles. MD simulations cover a wide range of physical conditions, including varying impact velocities, particle sizes, and material compositions, to provide a thorough understanding of collision outcomes. The results identify critical thresholds for sticking, bouncing, and fragmentation, enhancing broader astrophysical models of dust evolution. This work underscores the significance of cohesive forces and material properties in determining collision behavior. The presented model involves the collision of two dust aggregates, each consisting of a few million atomic particles, at impact velocities around the threshold value, known as the bouncing velocity (Vb ), evaluated using the macroscopic Johnson-Kendall-Roberts (JKR) model. The model material mainly consists of silica, as the main material of rocky planets and water, which is widely distributed across the solar system. The findings demonstrate the range of validity of the JKR theory at the atomic scale, influenced by the complexity of the internal structure of the colliding agents. These insights contribute to our understanding of dust growth mechanisms in protoplanetary disks, advancing knowledge of cosmic dust dynamics and its implications for planet formation and the interstellar medium. The simulation data can also refine larger-scale modeling methods, such as granular mechanics.

Sign, Signifier and Signified in Schrödinger's box

This study of the article proposes an interdisciplinary approach, integrating quantum mechanics and structuralism to elucidate the complex dynamics of signification. By paralleling the ambiguous nature of subatomic particles with the linguistic system, the study examines the arbitrary relationship between sign, signifier, and signified through quantum principles. Key concepts from quantum mechanics, such as wave-particle duality, superposition, entanglement, and observer effect, are applied to Saussure's theory of signs, revealing intriguing analogies between the two domains. The research critically examines the uncertain aspects of lingual systems, using Saussure's theory and Schrödinger's cat experiment to illuminate the complex relationships between signs, signifiers, and signifieds.This approach can enhance our understanding of language, cognition, and the human experience by shedding light on the intricate dynamics of meaning-making in human communication.•By applying quantum principles to Saussure's framework of sign, signifier, and signified, the study attempts to understand the intricate mechanisms that govern how meaning is created in human minds.•Exploring the parallels between linguistic ambiguity and quantum theory reveals the complex interplay between language, thought, and reality, and how they influence one another.•This approach not only enhances our understanding of quantum social sciences but also offers new perspectives on how language shapes our perceptions, interactions, and understanding of the world around.

Mallarmé's Poetic Creation and Quantum Physics, Epistemic and Epistemological Similarities

The pioneers of quantum physics have proven that everything is connected to everything in the universe. One of them, Austrian physicist Erwin Schrödinger, has pertinently summarized this reflection in a famous aphorism as follows: “The total number of minds in the universe is one. In fact, consciousness is a singularity phasing within all beings". Such interconnectedness exists not only at the level of subatomic and atomic particles, but also at the macrocosmic and supergalactic level. It can be extended to most disciplines of human knowledge as well. That is why a meticulous study shows that even epistemic areas that seem -aprioristically-incompatible with each other are -factually-cryptically connected. One of the most striking cases of such connectedness is Mallarmé's poetry and quantum physics. Indeed, the major guiding principles inherent in quantum physics are also shared by Mallarmé's poetry: The exceptional power of creative imagination, the indeterministic, probabilistic modus operandi, and quantum non-locality, to mention but a few. In this respect, the goal of our study is to underscore and analyze the kinship between Mallarmé's poetry and quantum physics and decrypt the hermeneutic, heuristic, and epistemological framework that undergirds that kinship. We will use a transdisciplinary approach to knowledge for this specific purpose.

Reducing the diameter of the atomized particles by coating polymer membrane on the inner wall of micro-tapered holes of the ultrasonic mesh atomizers

Atomized inhalation therapy with its rapid efficacy, low side effects and high medicine utilization, has become a crucial method for treating respiratory diseases. The depth of atomized particles deposition in the respiratory tract mainly depends on the particle diameter, making the reducing of the atomized particle size crucial for medicine deposit in lung. In the existing literatures, for the widely used dynamic mesh atomizer, the majority of the researches focused on the mechanical structure and the vibration characteristics of the atomizers. However, there is little researches on the micro-tapered holes of the metal sheet of the atomizer, despite the fact that the diameter of these tapered holes determines the size of the atomized particles. Due to the processing technology, the diameter of the micro-tapered holes cannot be further reduced, which greatly limits the development of the dynamic mesh atomizer in inhalation therapy. In this study, we consider the use of polymer coating on the inner wall of the micro-tapered holes to eliminate burrs, reduce the diameter of the holes, and ultimately reduce the size of the atomized particles. A theoretical model of the initial thickness of the coating polymer membrane and the rupture depth under the uniform air pressure applied to a single tapered hole was established. The metal sheets with different initial coating thicknesses were processed to verify the theoretical model by observing the quality of the inner surface and measuring the diameter of the holes. The particle size measurement experiment results show that when the initial coating thickness was 3 μm and 4.5 μm, the average particle sizes were reduced by 12.5 % and 23.2 %, respectively. Therefore, the proposed method can effectively reduce the atomized particles size, which helps to efficiently deposit atomized drugs in the lungs.

Tailored Interaction between Cellulose Nanowhiskers and Core-Shell Particles Determines the Optical and Mechanical Properties in Hybrid Films.

Hybrid materials of core-shell particles and cellulose nanowhiskers (CNWs) were synthesized to produce opal films with increasing tensile strength. After the incorporation of CNWs into the processed particle films, differences in the mechanical and optical properties were noticeable, which stemmed from the adhesion forces between the cellulose and the particles' shell material. Two different particle compositions were compared, using polystyrene as cores, and either poly(ethyl acrylate) (PEA) or a copolymer of ethyl acrylate and 3 wt % of 2-hydroxyethyl methacrylate (HEMA) as the shell material. Stronger interactions between the particles containing HEMA and the CNWs were displayed via atomic force microscopy particle manipulation experiments, where higher forces were required to deliberately move P(EA-co-HEMA) particles on a CNW substrate compared to PEA particles. The stronger interaction behaviors increased the disorder of the particles within the opal films toward photonic glasses with angle-independent structural colors. Also, the increase in tensile strength from <1 MPa at a cellulose content of 0 wt % to 6 MPa at the optimal CNW content of 15 wt % was more pronounced compared to the particle-cellulose mixture with only PEA in the particle shell. Thus, the presence of the hydroxy groups in the particles' shell material on the molecular level significantly influenced the optical and mechanical properties on the macroscopic level.

Exploring Kink Solitons in the Context of Klein–Gordon Equations via the Extended Direct Algebraic Method

This work employs the Extended Direct Algebraic Method (EDAM) to solve quadratic and cubic nonlinear Klein–Gordon Equations (KGEs), which are standard models in particle and quantum physics that describe the dynamics of scaler particles with spin zero in the framework of Einstein’s theory of relativity. By applying variables-based wave transformations, the targeted KGEs are converted into Nonlinear Ordinary Differential Equations (NODEs). The resultant NODEs are subsequently reduced to a set of nonlinear algebraic equations through the assumption of series-based solutions for them. New families of soliton solutions are obtained in the form of hyperbolic, trigonometric, exponential and rational functions when these systems are solved using Maple. A few soliton solutions are considered for certain values of the given parameters with the help of contour and 3D plots, which indicate that the solitons exist in the form of dark kink, hump kink, lump-like kink, bright kink and cuspon kink solitons. These soliton solutions are relevant to actual physics, for instance, in the context of particle physics and theories of quantum fields. These solutions are useful also for the enhancement of our understanding of the basic particle interactions and wave dynamics at all levels of physics, including but not limited to cosmology, compact matter physics and nonlinear optics.

Detection resolving power of SiC Timepix3 detector to electrons, neutrons, ions and protons

Silicon Carbide is a suitable semiconductor sensor for radiation measurement and nuclear applications. It has been recently implemented as a position-sensitive and radiation imaging device coupled to the Timepix3 ASIC chip in the form of a miniaturized radiation camera MiniPIX-Timepix3 SiC. In this work we systematically evaluate the detection resolving power to different radiation species: electrons, fast neutrons, ions and protons. Experimental calibrations were made at well-defined reference fields in terms of particle type, energy and direction. The spectral-sensitive tracking response and characteristic morphology of the particle tracks are analyzed by pattern recognition algorithms. The low thickness of the radiation sensitive volume (65 μm) of the SiC sensor limits the directional tracking response and angular resolution. Three broad classes of particle-type events are resolved. The detector together with suitable data processing can be used for radiation dosimetry and particle tracking tasks in space, particle therapy, nuclear physics and nuclear reactors and particle accelerator environments.

Study on the influence of aerosol atomization by ultrasonic atomization on coal spontaneous combustion

ABSTRACT Influenced by the complex environment and the nature of process materials in goaf, the prevention and control of spontaneous combustion of coal (CSC) in the deep part of goaf were facing many difficulties. To investigate the performance of ultrasonic atomized aerosols, a series of atomization experiments were conducted using a self-developed ultrasonic atomization device. The main conclusions are as follows: under the same atomization conditions, the atomized particle sizes of several inhibitors (except PAS-W) are concentrated in the <8 μm range, with a content of more than 88%, indicating that the aerosol particles produced by ultrasonic atomization are small in size and uniform in distribution. Compared with water and MgCl2 inhibitors, aerosol particles produced by PAS-W are less likely to pass through the voids of the coal body, and have poorer permeability and diffusivity. As the temperature increases, the viscosity and surface tension of the inhibitor decrease, and the percentage of aerosol particles with particle size <8 μm produced by ultrasonic atomization is more than 88%, indicating that the atomization effect is improved. After increasing the temperature, the contact angle between PAS-W inhibitor and coal reduces from 54.7° to 40.8°, and the wettability is better. Compared with raw coal, the final temperature of the PAS-W aerosol treated coal sample is delayed 21.86°C, and has significant retarding property. When the wind speed is 3 m/s, the effect of PAS-W aerosol particle generation, permeability, and particle size distribution is the best. The results of the study are of great significance in improving the ultrasonic atomized aerosol fire prevention technology and realizing large-scale CSC prevention in goaf.

Mitigating the Kinetic Hysteresis of Co-Free Ni-Rich Cathodes via Gradient Penetration of Nonmagnetic Silicon.

Co-free Ni-rich layered oxides are considered a promising cathode material for next-generation Li-ion batteries due to their cost-effectiveness and high capacity. However, they still suffer from the practical challenges of low discharge capacity and poor rate capability due to the hysteresis of Li-ion diffusion kinetics. Herein, based on the regulation of the lattice magnetic frustration, the Li/Ni intermixing defects as the primary origin of kinetic hysteresis are radically addressed via the doping of the nonmagnetic Si element. Meanwhile, by adopting gradient penetration doping, a robust Si-O surface structure with reversible lattice oxygen evolution and low lattice strain is constructed on Co-free Ni-rich cathodes to suppress the formation of surface dense barrier layer. With the remarkably enhanced Li-ion diffusion kinetics in atomic and electrode particle scales, the as-obtained cathodes (LiNixMn1-xSi0.01O2, 0.6≤x≤0.9) achieve superior performance in discharge capacity, rate capability, and durability. This work highlights the coupling effect of magnetic structure and interfacial chemicals on Li-ion transport properties, and the concept will inspire more researchers to conduct an intensive study.

Mitigating the Kinetic Hysteresis of Co‐Free Ni‐Rich Cathodes via Gradient Penetration of Nonmagnetic Silicon

AbstractCo‐free Ni‐rich layered oxides are considered a promising cathode material for next‐generation Li‐ion batteries due to their cost‐effectiveness and high capacity. However, they still suffer from the practical challenges of low discharge capacity and poor rate capability due to the hysteresis of Li‐ion diffusion kinetics. Herein, based on the regulation of the lattice magnetic frustration, the Li/Ni intermixing defects as the primary origin of kinetic hysteresis are radically addressed via the doping of the nonmagnetic Si element. Meanwhile, by adopting gradient penetration doping, a robust Si−O surface structure with reversible lattice oxygen evolution and low lattice strain is constructed on Co‐free Ni‐rich cathodes to suppress the formation of surface dense barrier layer. With the remarkably enhanced Li‐ion diffusion kinetics in atomic and electrode particle scales, the as‐obtained cathodes (LiNixMn1−xSi0.01O2, 0.6≤x≤0.9) achieve superior performance in discharge capacity, rate capability, and durability. This work highlights the coupling effect of magnetic structure and interfacial chemicals on Li‐ion transport properties, and the concept will inspire more researchers to conduct an intensive study.