Charged Mass Research Articles

Symmetric multipath branching as a layout design strategy for blast-resilient tunnel structures

Explosions can result in massive fatalities and severe damage to structures and facilities in tunnels. Therefore, it is of crucial importance to incorporate disaster mitigation strategies against potential blast scenarios in the design of such structures and implement viable solutions to attenuate the destructive effect of blast waves caused by explosions. To this end, we propose an innovative layout design strategy called symmetric multi-path branching, where multiple closed-end paths with relatively small cross-sectional areas branch out laterally from the sides of a straight and prismatic tunnel. To exploit the neutralizing effect of colliding pressure waves, a reflective symmetry with respect to the longitudinal mid-plane of the tunnel is considered in the layout design. To examine the effectiveness and efficiency of this strategy in reducing the effect of the pressure wave caused by the explosion, a series of layout designs are produced and investigated numerically and experimentally. After verifying the simulation method, the effect of the branching angles, cross-sectional geometry, drilling depth, and location of the branches, as well as the mass of the explosive charge, are studied systematically. The results illustrate an acceptable match between the numerical and the scaled experimental test methods. Moreover, it is shown that using three pairs of branches with an appropriate geometry and branching angles can attenuate the pressure waves passing through the tunnel up to 50% without obstructing the main route. The findings of this study can be applied to designing blast-resilient layouts in the development of underground tunnels and other corridor-like structures.

Extended Ginzburg-Landau theory of superconductivity from generalized momentum operator and position-dependent mass

The concept of generalized momentum operator which is motivated from the generalized uncertainty principle has been extensively investigated in quantum mechanics and various aspects of theoretical and applied physics. In this study, we have applied this formalism to Ginzburg-Landau theory of superconductvity and Abrikosov vortex lattice in type II-superconductors. After deriving the extended Ginzburg-Landau equations, we have discussed several independent structures of the auxiliary function of position operator in the generalized momentum operator and we have analyzed their features in both Ginzburg-Landau and London theories. Comparable properties to the basic formalism have been obtained even without the presence of the cubic nonlinear term in Ginzburg-Landau equations. However, not all structures of the auxiliary function of position operator result on the exclusion of the magnetic field from a superconductor when it's below its critical temperature. But, only specific forms may succeed to eliminate the magnetic field. This approach has been generalized by considered a position-dependent mass of the electric charge. Amazingly, for a position-dependent mass of hyperbolic soliton-like structure, the extended Ginzburg-Landau wave function is identical to the result obtained in the conventional formalism and besides, for specific correlations between the auxiliary function of the position operator and position-dependent mass, the exclusion of the magnetic field is conceivable. We have also discussed the Abrikosov vortex lattice solution based on the extended Ginzburg-Landau formalism with position-dependent mass of the electric charge. It was observed that, for a specific structure of the position-dependent mass and for a quantum number n=0, a transition between a type-II and type-I superconductor takes place if the Ginzburg-Landau parameter is κ=121+257≈2.0634. For large n, the problem depends on the asymptotic form of the Hermite polynomial and periodicity occurs if the electric charge is quantized. Further details are obtained and analyzed.

Roughness Factors of Electrodeposited Nanostructured Copper Foams

Copper-based electrocatalytic materials play a critical role in various electrocatalytic processes, including the electroreduction of carbon dioxide and nitrate. Three-dimensional nanostructured electrodes are particularly advantageous for electrocatalytic applications due to their large surface area, which facilitates charge transfer and mass transport. However, the real surface area (RSA) of electrocatalysts is a crucial parameter that is often overlooked in experimental studies of high-surface-area copper electrodes. In this study, we investigate the roughness factors of electrodeposited copper foams with varying thicknesses and morphologies, obtained using the hydrogen bubble dynamic template technique. Underpotential deposition (UPD) of metal adatoms is one of the most reliable methods for estimating the RSA of highly dispersed catalysts. We aim to illustrate the applicability of UPD of lead for the determination of the RSA of copper deposits with hierarchical porosity. To find the appropriate experimental conditions that allow for efficient minimization of the limitations related to the slow diffusion of lead ions in the pores of the material and background currents of the reduction of traces of oxygen, we explore the effect of lead ion concentration, stirring rate, scan rate, monolayer deposition time and solution pH on the accuracy of RSA estimates. Under the optimized measurement conditions, Pb UPD allowed to estimate roughness factors as high as 400 for 100 µm thick foams, which translates into a specific surface area of ~6 m2·g−1. The proposed measurement protocol may be further applied to estimate the RSA of copper deposits with similar or higher roughness.

Enhanced stability and efficiency of 2-MAQ|Fc redox flow battery with a microemulsion electrolyte

Microemulsion-based redox flow batteries (RFBs) are gaining popularity due to the characteristics of microemulsions that decouple the solubility of redox species and ionic conductivity, affording a fantastic opportunity to simultaneously extend the electrochemical window and increase the ionic conductivity of electrolytes. In this work, we report a novel microemulsion-based RFB employing with 2-methylanthraquinone and ferrocene as anolyte and catholyte, respectively. Molecular dynamics and density function theory analysis investigated the electrochemical mechanism of redox species, including the intricate process of interface mass transport. The redox flow chemistry exhibits outstanding charge transfer rates and mass diffusion as well as good cycling stability under both cyclic voltammetry and linear sweep voltammetry. The flow cell demonstrated a coulombic efficiency of 96 %, voltage efficiency of 80 % and energy efficiency of 76.6 % after 300 cycles, making it one of the most stable and high-efficiency microemulsion-based RFBs reported so far. Although more advancement is still required to spark practical interest, this study opens a promising pathway to raise the energy density for redox flow batteries and is anticipated to inspire more in-depth studies of stable and high-efficient microemulsion-based RFBs.

Enhancing performance of molten carbonate electrolysis cell via deposition of gold nanoparticles on anode

The power-to-gas method utilizing electrolysis has attracted attention for ecofriendly and efficient energy storage. The use of a molten carbonate electrolysis cell (MCEC) allows the production of a large amount of hydrogen using carbonate electrolytes. However, compared with conventional fossil-fuel-based production methods, the use of MCECs involves higher costs and a lower efficiency, necessitating the exploration of strategies to improve MCECs performance. To this end, herein, an AuNP-deposited anode is proposed for improving the performance of MCECs. Au nanoparticles (AuNPs) can enhance the oxygen evolution reaction (OER) activity, increase the reaction surface area, and increase the electrical conductivity of the anode. Additionally, because of their oxygen molecule desorption properties, AuNPs are suitable anode catalyst materials for MCECs. By depositing AuNPs on the anode, the conductivity was increased, reducing the Ohmic resistance, and the charge transfer resistance and mass transfer resistance due to the characteristics of the OER and oxygen gas desorption were significantly reduced.

Entrance channel dependence of quasi fission in reactions leading to 206Po compound nucleus

The evaporation residue (ER) cross sections for the reaction F19+187Re→206Po⁎ are measured, in the excitation energy range of 86.1 to 118.4 MeV. The measured cross sections are compared with that of 30Si + 176Yb reaction populating the same compound nucleus. Theoretical calculations are performed using the coupled - channels calculations for the capture cross sections and statistical model calculations for the ER cross sections. The dependence of quasi fission on entrance channel parameters such as charge product (Z1Z2), mass asymmetry (α), target deformation (β2) and effective fissility (χeff) are studied.

The influence of ball collision charging on carbon recovery of fly ash triboelectrostatic separation

ABSTRACT The recovery of unburned carbon particles from fly ash by triboelectrostatic separation can realize energy conservation and solid waste recycling. Collision charging by metal ball has been proposed to enhance the particle charging and improve the unburned carbon recovery efficiency. It can increase the particle contact area, shorten the contact time, and improve the charge–mass ratio of particles. The charging model of ball collision was established. The collision charging process between particles and ball was simulated by CFD-DEM coupling method. The influence of ball material and gas velocity on the charge–mass ratio was studied, and that of gas velocity and voltage on separation was evaluated by experiments. The results showed that the collision charge between particles and metal ball was greater than that between particles. With the gas velocity of 30 m/s, Cu ball collisions obtained a relative maximum charge–mass ratio of 0.393nC/g and 0.275nC/g for carbon and ash particles, respectively. The reasonable experimental conditions were gas velocity of 20 m/s and voltage of 15kV. The loss on ignition of 14.3% and carbon recovery of 90.36% were obtained. Compared with the no-ball system, the ball collision improved the carbon recovery rate by 55.20%.

Numerical investigation on the influence of geometrical parameters on the temperature distribution in marine hydrogen storage tanks during filling

This paper established a two-dimensional axisymmetric model with a marine high-pressure hydrogen storage tank as the research object. Using numerical simulation, the effects of different aspect ratios, inlet diameters, and inlet pipe lengths on the temperature rise of the hydrogen storage tank during the filling process were studied. As the L/D ratio of the hydrogen storage tank increases, the momentum of the hydrogen gas reaching the bottom of the tank gradually decreases, making it easier to form localized high-temperature regions. For a hydrogen storage tank with an L/D of 6.0, the difference between the maximum and average temperature at the end of filling was 155.85 K. In contrast, the temperature difference of the tank with an L/D of 3.6 was only 32.81 K. In addition, the inlet pipe delivers the hydrogen deep into the tank and reduces the obstructing effect of the existing hydrogen in the tank on the newly filled hydrogen. For smaller L/D hydrogen storage tanks, the inlet pipe may backfire and create a high-temperature zone at the shoulder of the tank. In contrast, for larger L/D hydrogen storage tanks, a suitable length of inlet pipe can deliver the hydrogen deep into the tank. This will enhance the gas flow inside the tank, facilitating heat exchange and avoiding the formation of localized high-temperature areas at the bottom of the tank. However, excessively long inlet pipes can also lead to high-temperature areas on the shoulders. At a specific charge mass flow rate, the lower the inlet diameter, the higher the hydrogen flow rate. The larger flow rate helped promote uniform hydrogen mixing in the tank and made it challenging to form localized high-temperature regions.

3D printing of combustive inks for hierarchically porous electrochemical electrodes

Monolithic porous metals have attracted great interest due to their excellent material properties such as high specific surface area, low density and good electrical conductivity. Herein, a novel 3D printing approach is proposed to construct self-supporting nickel electrodes with digitally programmable macropores and combustion-induced nanopores through a facile “direct ink writing and combustion synthesis” strategy. The pore size distribution and composition of the electrodes can be adjusted by carefully designing the combustive ink composition and controlling the parameters of the combustion process. Chain-like nickel microstructures generated by combustion act as “bridges” to give the electrodes robust mechanical and electrical properties and simultaneously increase electrochemical active sites. In addition, the hierarchical porosity promotes charge transfer and mass transfer at the NiFe nanosheet electrode, with overpotentials of ∼289 mV and 131 mV for oxygen and hydrogen evolution reactions, respectively, at 30 mA·cm-2. This work highlights a new 3D printing strategy for fabricating hierarchically porous structures, which can be applied to energy storage and conversion, catalysis, adsorption, gas sensing, and separation.

Gauged SU(3)F and loop induced quark and lepton masses

We investigate a local SU(3)F flavour symmetry for its viability in generating the masses for the quarks and charged leptons of the first two families through radiative corrections. Only the third-generation fermions get tree-level masses due to specific choice of the field content and their gauge charges. Unprotected by symmetry, the remaining fermions acquire non-vanishing masses through the quantum corrections induced by the gauge bosons of broken SU(3)F. We show that inter-generational hierarchy between the masses of the first two families arises if the flavour symmetry is broken with an intermediate SU(2) leading to a specific ordering in the masses of the gauge bosons. Based on this scheme, we construct an explicit and predictive model and show its viability in reproducing the realistic charged fermion masses and quark mixing parameters in terms of not-so-hierarchical fundamental couplings. The model leads to the strange quark mass, ms ≈ 16 MeV at MZ, which is ~2.4σ away from its current central value. Large flavour violations are a generic prediction of the scheme which pushes the masses of the new gauge bosons to 103 TeV or higher.

The role of U(1) A symmetry breaking in the QCD corrections to the pion mass difference

The charged and neutral pion mass difference can be attributed to both the quantum electrodynamics and QCD contributions. The current quark mass difference (Δm) is the source of the QCD contribution. Here, in a two-flavour non-local Nambu–Jona-Lasinio model, we try to estimate the QCD contribution. Interestingly, we find that the strength of the symmetry-breaking parameter c plays a crucial role in obtaining the pion mass difference while intertwined with the current quark mass difference. To obtain the QCD contribution for the pion mass difference, we scan the parameter space in {Δm, c}, and by comparing this with the existing results, we constrained the parameter space. Further, using a fitted value of c, we determine the allowed range for the Δm in the model. The model estimated Δm ranges enable us to extract the chiral perturbation theory low energy constant, l 7 and verify the dependence of the pion mass difference on Δm. We also find out its dependence on c—it increases with the decreasing value of c, i.e. toward an axial anomaly restored phase.

PdNi alloys with surface segregation of Pd@hydrophilic N, O doped carbons toward hydrogen production with high current densities

A series of catalysts, which consist of PdNi alloy cores and N, O co-doped carbon (NOC) shells, are developed by pyrolysis of metal–organic framework (PdNi) for hydrogen production with high current densities. The bulk or surface Pd compositions (Pd/(Pd + Ni) molar ratios) of PdNi alloys can be well controlled by the fed ones. Meanwhile, some structural features that are favorable to HER activity, especially to achieving high HER current densities under low overpotentials, are further adjusted by the Pd compositions, including d-band center (εd) of PdNi alloy affected by surface segregation of Pd, hydrophilicity of NOC shell, and charge transfer and mass diffusion efficiency of an entire catalyst. When the bulk Pd/(Pd + Ni) molar ratio is ∼ 0.21, Pd0.21Ni0.79@NOC has a moderate εd, the highest hydrophilicity, the highest charge transfer and mass diffusion efficiency, and finally the highest electric double-layer capacitance (or electrochemical active surface area). Accordingly, it affords the optimal apparent or specific activity for hydrogen production with high current densities under low overpotentials in 0.5 M H2SO4, including a low apparent η1000 of ∼ 240 mV or specific η2500(BET) of ∼ 240.9 mV, and a high current density of ∼ 1590 mA cm−2 at only ∼ 242 mV.

Effect of load details of the successive explosions on the blast behaviors of reinforced concrete beams

SummaryThe objective of this study was to study the effect of load details of successive explosions on the blast behaviors of reinforced concrete (RC) beams. First, the effect of the successive loading of two identical explosions was discussed by considering the influences of standoff distance, charge mass on the failure states, and structural responses (displacement and support reaction force). And keeping the total TNT charge mass of 1 kg unchanged, the effect of loading numbers was investigated by loading two 0.5 kg TNT successively and a single 1 kg TNT on RC beams, respectively. Besides, the successive loading of two different explosions was also considered by investigating the effects of loading sequences and the first explosion induced pre‐damage on the ultimate accumulated damage of RC beams. At last, based on the reaction force and displacement responses, a nonlinear relationship between the dynamic residual load‐carrying capacity and the accumulated residual displacement was obtained to assess the damage states of the tested beams. The results show that the local failure range along the beam span direction (length of peeling‐off and length of spallation) caused by the first blast load did not apparently increase when the damaged beams were subjected to another blast load. With the increase in explosion numbers, depth of compressive crushing increases gradually. At the same stand‐off distance (from 0.25 to 0.45 m), due to the damage accumulation effect, successive loading of two 0.5 kg TNT can trigger more severe local failure but smaller accumulated residual deflection to beams than the single loading of a 1 kg TNT. Besides, when two different blast loads are loaded on tested beams, the loading sequence of the larger one first and then the smaller one (1 kg TNT/0.5 kg TNT at h = 0.45 m) can trigger larger damage to beams than the opposite loading sequence (0.5 kg TNT/1 kg TNT at h = 0.45 m). And for the beams subjected to a smaller blast load first and then a larger one, a stiffer behavior may be triggered by the second blast load on the beam after the first loading of the smaller blast load due to the residual strain in longitudinal reinforcement. Furthermore, based on the nonlinear relationship between residual load‐carrying capacity and residual displacement, the accumulated damage of RC beams was divided into mainly four phases.

Electrogravity Field of a Charged Mass Object

Electrogravity Field of a Charged Mass Object

A recurrent neural network model for structural response to underwater shock

Simulating the dynamic response of structures to shock involves numerical models that can require significant effort and computational resources to create and solve. This can make accurate naval platform vulnerability analyses involving a large number of simulations impractical and motivates the development of efficient surrogate models for shock and blast effects. This paper presents a novel approach to predicting the response of a floating structure to underwater shock based on machine learning (ML). Velocity time-series for a rigid floating plate subjected to underwater shock and cavitation effects are calculated for a range of charge mass, standoff distance and plate mass per unit area values using a coupled Eulerian–Lagrangian (CEL) numerical model. The computed motions are used to train a recurrent neural network (RNN) to predict the plate response including the effect of reloading due to the cavitation closure pulse. The RNN predicts plate responses from a test set of CEL model instances with a mean value of mean-squared errors between the ML and CEL model velocities, normalized with respect to the velocity ranges, of 1.5 × 10-4.

Asymmetrical braneworlds and the charged lepton mass spectrum

A braneworld mechanism for explaining the mass spectrum of the charged leptons is proposed. Based on the existence of an asymmetric warp factor for a 5+1-dim braneworld scenario, the proper fractions between the masses of the electron, muon and tauon are achieved. As a straightforward consequence, our results coincide with the Koide's mass formula.

Degradation of polysorbate investigated by a high-performance liquid chromatography multi-detector system with charged aerosol and mass detection

Polysorbate 80 is widely used as a formulation component in biopharmaceutical drug products. Recent studies have shown that polysorbate 80 is readily degraded either through direct or indirect means. The degradation of polysorbate 80 causes a concern for the long-term stability of biopharmaceutical drug product, as the breakdown products of polysorbate 80 have been shown to cause adverse effects, such as formation of sub-visible and visible particles and mAb aggregation. Understanding the path and extent of degradation is of a paramount importance for the formulator during formulation development. A multi-detector HPLC system using charged aerosol and mass detection was developed and optimized for the characterization of polysorbate 80 standards. The system included a post-column make-up flow, i.e. an inverse gradient, that enabled constant eluent composition at the detectors. The inverse gradient eliminated the main source of variability for the charged aerosol detector response, thereby enabling the calculation of the mass balance between polysorbate components with different degrees of esterification. Extracted ion chromatograms of the mass detector combined with their respective retention times were used to qualitatively characterize the polysorbate samples down to the individual components. The system was applied to study the degradation of several polysorbate standards which occurred by enzymatic digestion or long-term storage. The system provided detailed information on the mechanism of degradation without the need for additional orthogonal analytical techniques.

Mixed potential type methanol gas sensor based on Gd2Zr2O7 solid state electrolyte and ZnSb2O6 sensing electrode

With the development of methanol fuel cell vehicles, the hidden danger of methanol leakage has become a safety problem that cannot be ignored. The timely and effective detection of methanol is the premise to ensure safety. Herein, a mixed potential type methanol sensor was developed using Gd2Zr2O7 solid state electrolyte and ZnSb2O6 sensing electrode. The fabricated sensor can realize effective detection in a wide range of 0.2–1000 ppm with the sensitivities of − 4.7 mV/ppm and − 55.9 mV/decade to 0.2–5 ppm and 5–1000 ppm methanol. The sensing behavior of the sensor is explained based on mixed potential sensing mechanism in two cases of charge transfer-limiting and mass transport limiting processes. By comparing the sensing behavior under illumination conditions, it is found that the sensing performance of the mixed potential sensor can be improved by adjusting the wavelength and intensity of excitation light. The sensor possessed good repeatability, selectivity and stability in the systematic and detailed evaluation of sensing performances, which proves its potential and reliability for practical application in methanol fuel vehicles.

Chemical deposition from a liquid crystal template: A highly active mesoporous nickel phosphate electrocatalyst for hydrogen green production via urea electro-oxidation in an alkaline solution

Recently the urea and urinated wastewater electrolysis process has shown promising technology for hydrogen fuel green production in addition to denitrification of wastewater. However, to make the process economically valuable, the electrocatalysts nanoarchitecture, nanometer size, shape, facets, and composition need to be engineered to boost the urea oxidation reaction (UOR). This work demonstrates a simple and novel approach to the synthesis of mesoporous nickel phosphate nanoparticles (meso-NiPO) via chemical deposition from a surfactant liquid crystal template. Typically, the nickel ions dissolved in the aqueous domain of the hexagonal liquid crystalline phase of the Brij®78 template were chemically reacted with the sodium phosphate solution to precipitate the mesoporous nickel phosphate nanoarchitecture after washing up the surfactant. The physicochemical characterizations show the meso-NiPO exhibits an amorphous highly mesoporous structure with a higher specific surface area (43.50 m2/g) compared to the bare nickel phosphate (bare-NiPO, 4.26 m2/g) prepared in the absence of surfactant. The electrochemical performance of meso-NiPO electrocatalyst for the urea oxidation reaction in alkaline solution exhibits superior activity including a lower oxidation onset potential (0.30 V vs. Ag/AgCl), charge transfer resistance (3.35 O) and mass activity of 700.7 mA/cm2 mg at the oxidation potential of 0.6 V vs. Ag/AgCl. Moreover, the meso-NiPO reveals long-term stability, and 97.5% of the steady-state oxidation current was maintained after the 3-hour urea electrolysis test. Using an H-shape urea electrolyzer, the corresponding cathodic hydrogen production rate reached 415 µmol/h and a Faradic efficiency of 96.8 % at an applied bias of 2.0 V. The electroactivity high performance of the mesoporous nickel phosphate is ascribed to the high specific surface area and mesoporous architecture that provide efficient charge transfer, as well as mass transport of the electroactive species. The chemical deposition from a surfactant liquid crystal template has the advantages of a one-pot template, applicable to the synthesis of a wide range of nanomaterials with various compositions and nanoarchitectures at room temperature for application in electrochemical energy production and storage systems.

Tri-Bi-Maximal flavor pattern deviation using equivalent class

We assume that the neutrino mass matrix Mν, in the model-independent context, is diagonalized by the Tri-Bi-Maximal (TBM) pattern. In the following, we explore the TBM mixing pattern deviation by considering different textures for the charged lepton matrix, which are classified into equivalence classes that allow us to reproduce the experimental data on neutrino oscillation. Our target is on the charged lepton matrix with the minimum number of free parameters, i.e., the maximum number of zeros of the texture that allows us to correctly reproduce the value of the reactor mixing angle θ13. We show a deviation from the TBM pattern in terms of the charged leptonic masses, which provides a prediction value for the phase factors in the charged lepton mass matrices. These are related to the “Dirac-like” CP and “Majorana-like” phase factors. For the last type of phase, we show its phenomenological implications through effective Majorana mass in the neutrinoless double-beta decay.