Net Electric Charge Research Articles

Modeling net-charge fluctuations in heavy-ion collisions at the LHC

Abstract The analysis of Pb+Pb data for net-charge fluctuations at LHC energies
within the HYDJET++ model is presented. The strongly intensive
quantities $D$ and $\Sigma$ are used to get rid of the effects related
to volume fluctuations of the system. We employ two versions of the
HYDJET++ for the analysis. The first one is the standard or default
version, whereas the second one represents its further modification,
which takes into account explicit event-by-event conservation of the
electric net-charge of produced particles. Inclusion of the canonical
net-charge conservation in the model allows one for better description
of the experimental data obtained by the ALICE and the CMS
Collaborations. Comparison with calculations of other models is also
presented.

Water-Polymer Slide Electrification in Polyethylene Films Coated with Amphiphilic Compounds and Its Connection to Surface Properties Dependent on Water-Polymer Interactions.

Slide electrification experiments were performed on low-density polyethylene films (PE) and PE sprayed with five amphiphilic compounds, including antistatic and slip additives. Drops of aqueous solutions were delivered on the films and after sliding spontaneously acquired a net electrical charge (Qdrop), which is dependent on the pH and ionic strength. The slide electrification was detected in pristine PE films and those with five additives. An acid-base equilibrium model, based on the adsorption of hydroxides and protons on surface sites, accounted for the dependence of Qdrop on pH, allowing recovery of the acid-base equilibrium constants and the density of adsorption sites. The model was modified to account for ionic strength effects through activity factors. The surface conductivity, wettability, and friction coefficients were strongly modified by the additives. However, the observed trends are different from those observed in slide electrification, which better correlated with zeta potential determinations. This suggests that the interaction mechanisms among surface water, the considered additives, and the polymer, which are involved in slide electrification and the generation of zeta potential, are different from those associated with other surface processes involving surface water. Although additives are required for changing surface resistivity, friction coefficients, and wettability, the generation of sliding electrical charges in polyethylene is a spontaneous and highly effective process. For one specific additive, a simultaneous decrease in friction coefficients, zeta potential, and Qdrop was observed, assigned to the blockade of hydroxide adsorption sites and water repulsion by the compound.

Strangeness-correlations on the pseudocritical line in ( 2+1 )-flavor QCD

We present some lattice QCD results on first (χ1i) and second (χ2i) cumulants of and correlations (χ11ij) among net baryon-number (B), strangeness (S) and electric charge (Q) along the pseudocritical line [Tpc(μB)] in the temperature (T)–baryon chemical potential (μB) phase diagram of (2+1)-flavor QCD. We point out that violations of sum rules among second order cumulants, which hold in the isospin symmetric limit of vanishing electric charge chemical potential, are small along the Tpc(μB) for the entire range of μB covered in the RHIC beam energy scan. For the strangeness neutral matter produced in heavy-ion collisions this leads to a close relation between χ11BS and χ11QS. We compare lattice QCD results for χ11BS/χ2S along the Tpc(μB) line with preliminary experimental measurements of χ11BS/χ2S for collision energies 7.7 GeV≤sNN≤62.4 GeV. While we find good agreements for sNN≥39 GeV, differences are sizeable at smaller values of sNN. Moreover, we compare lattice QCD results for the ratio of the strangeness (μS) to baryon (μB) chemical potentials, which define a strangeness neutral system with fixed electric charge to baryon number density, with experimental results obtained by the STAR collaboration for μS/μB using strange baryon yields on the freeze-out line. Finally, we determine the baryon chemical potential at the freeze-out (μBf) by comparing χ1B/χ2B along the Tpc(μB) with the experimentally measured net-proton cumulants χ1p/χ2p. We find that {μBf,Tpc(μBf)} are consistent with the freeze-out parameters of the statistical-model fits to experimentally measured hadron yields for sNN≥11.5 GeV. Published by the American Physical Society 2024

Measurements of higher-order cumulants of multiplicity and net-electric charge distributions in inelastic proton–proton interactions by NA61/SHINE

This paper presents the energy dependence of multiplicity and net-electric charge fluctuations in p+p interactions at beam momenta 20, 31, 40, 80, and 158 GeV/c\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ ext{ Ge }\\hspace{-1.00006pt}\ ext{ V }\\!/\\!c$$\\end{document}. Results are corrected for the experimental biases and quantified with the use of cumulants and factorial cumulants. Cumulant ratios are an essential tool in the search for the critical point of strongly interacting matter in heavy ion collisions. Measurements performed in p+p interactions provide a vital baseline estimation in these studies. The measured signals are compared with the string hadronic models Epos1.99 and FTFP-BERT.

Fluctuations and Correlations of Conserved Charges Serving as Signals for QGP Production: An Overview from Polyakov Loop Enhanced Nambu–Jona-Lasinio Model

Quark–Gluon plasma driven by the strong force is subject to the conservativeness of the baryon number, net electric charge, strangeness, etc. However, the fluctuations around their mean values at specific temperatures and chemical potentials can provide viable signals for the production of Quark–Gluon plasma. These fluctuations can be captured theoretically as moments of different orders in the expansion of pressure or the thermodynamic potential of the system under concern. Here, we look for possible explanations in the methodologies used for capturing them by using the framework of the Polyakov–Nambu–Jona-Lasinio (PNJL) model under the 2 + 1 flavor consideration with mean-field approximation. The various quantities thus explored can act to signify meaningfully near the phase transitions. Justifications are also made for some of the quantities capable of serving necessarily under experimental scenarios. Additionally, variations in certain quantities are also made for the different collision energies explored in the high-energy experiments. Rectification of the quantitative accuracy, especially in the low-temperature hadronic sector, is of prime concern, and it is also addressed. It was found that most of the observables stay in close proximity with the existing lattice QCD results at the continuum limit, with some artifacts still remaining, especially in the strange sector, which needs further attention.

Partial MOF-derived BiFeO3 from Fe/Bi-BDC framework for efficient piezo-photocatalytic reduction of Cr(VI) and N2 fixation under visible light

Due to the synergistic properties of piezoelectric and photocatalysis, piezo-photocatalysts provide a new solution for the charge carriers produced during the reaction and can show higher efficiency in reducing environmental pollutants. The new aspect of photocatalysis is that photocatalysis uses sunlight to convert toxic mineral species into less dangerous ones. Also, the new aspect of piezoelectricity is that when the piezoelectric material is subjected to mechanical stress, the induced displacement of ions creates net electric charges throughout the material. In this paper, the calcined bimetallic sample (CBM-150) is a sample of BiFeO3 prepared at low temperature, that is partially derived from the Fe/Bi-BDC framework. The innovation of the used CBM-150 catalyst is that this catalyst was able to provide a new strategy to increase the charge separation efficiency of electron/hole pairs produced during the reaction through the synergy of piezoelectric and photocatalytic properties. The innovation of the CBM-150 catalyst is such that it was able to show 89% and 91% efficiency for Cr(VI) reduction in 40 minutes at neutral pH with a 20 W Xenon lamp and sunlight irradiation. CBM-150 also successfully produced 109.04 µmol.L-1.g-1.h-1 green ammonia through nitrogen fixation reaction. Finally, CBM-150 is an effective and low-cost piezo-photocatalyst that can be a promising candidate for the Cr(VI) reduction and efficient green ammonia production.

Baryon Electric Charge Correlation as a Magnetometer of QCD.

The correlation between net baryon number and electric charge, χ_{11}^{BQ}, can serve as a magnetometer of QCD. This is demonstrated by lattice QCD computations using the highly improved staggered quarks with physical pion mass of M_{π}=135 MeV on N_{τ}=8 and 12 lattices. We find that χ_{11}^{BQ} along the transition line starts to increase rapidly with magnetic field strength eB≳2M_{π}^{2} and by a factor 2 at eB≃8M_{π}^{2}. Furthermore, the ratio of electric charge chemical potential to baryon chemical potential, μ_{Q}/μ_{B}, shows significant dependence on the magnetic field strength and varies from the ratio of electric charge to baryon number in the colliding nuclei in heavy ion collisions. These results can provide baselines for effective theory and model studies, and both χ_{11}^{BQ} and μ_{Q}/μ_{B} could be useful probes for the detection of magnetic fields in relativistic heavy ion collision experiments as compared with corresponding results from the hadron resonance gas model.

Understanding the Effect of Conserved Charges on the Coalescence Sum Rule of Directed Flow

Recently, the rapidity-odd directed flow (v1) of produced hadrons (K−, ϕ, p¯, Λ¯, Ξ¯+, Ω−, and Ω¯+) has been studied. Several combinations of these produced hadrons, with very small mass differences but differences in the net electric charge (Δq) and net strangeness (ΔS) on the two sides, have been considered. A difference in v1 between the two sides of these combinations (Δv1) has been proposed as a consequence of the electromagnetic field produced in relativistic heavy-ion collisions, especially if Δv1 increases with Δq. Our study is performed to understand the effect of the coalescence sum rule (CSR) on Δv1. We point out that the CSR leads to Δv1=cqΔq+cSΔS, where the coefficients cq and cS reflect the Δv1 of produced quarks. Equivalently, one can write Δv1=cqΔq+cBΔB, involving the difference in the net baryon number ΔB, where the CSR gives cB=−3cS. We then propose two methods to extract the coefficients for the Δq and ΔS dependences of Δv1.

Electrically mediated self-assembly and manipulation of drops at an interface.

The fluid-fluid interface is a complex environment for a floating object where the statics and dynamics may be governed by capillarity, gravity, inertia, and other external body forces. Yet, the alignment of these forces in intricate ways may result in beautiful pattern formation and self-assembly of these objects, as in the case of crystalline order observed with bubble rafts or colloidal particles. While interfacial self-assembly has been explored widely, controlled manipulation of floating objects, e.g. drops, at the fluid-fluid interface still remains a challenge largely unexplored. In this work, we reveal the self-assembly and manipulation of water drops floating at an oil-air interface. We show that the assembly occurs due to electrostatic interactions between the drops and their environment. We highlight the role of the boundary surrounding the system by showing that even drops with a net zero electric charge can self-assemble under certain conditions. Using experiments and theory, we show that the depth of the oil bath plays an important role in setting the distance between the self-assembled drops. Furthermore, we demonstrate ways to manipulate the drops actively and passively at the interface.

Визначення водневого показника в точці нульового поверхневого заряду для гумінової кислоти бурого вугілля

Humic acids are a complex mixture of high molecular weight aromatic oxycarboxylic acids that act as polyelectrolytes. Their structure includes aromatic nuclei, side chains, and functional groups, resulting in a variation of physicochemical properties such as solubility and stability. Carboxylic and phenolic groups impart acidic properties, while amino groups cause amphotericity, which is related to the isoelectric point (pI). The amphiphilic character contributes to the formation of micelle-like structures in neutral and acidic environments. Humic acids form supramolecular colloids connected by hydrogen bonds. It is known that the pH at the zero charge point of different humic acids varies from 0.5 to 9.3, reflecting their chemical diversity. In our experiments humic acids were obtained by alkaline extraction from lignite with a carbon content of 40.5% and an ash content of 40%. The zero charge point (the pH at which a molecule carries no net electrical charge or is electrically neutral in the statistical mean) was determined by two methods using a pH titration procedure. These methods showed quite close pH values (2.0 and 1.6) at which the surface of humic acid has a net zero surface charge. This allows us to have information about the protonation state and charge dynamics of humic acid under different pH conditions. The data obtained helps to determine the solubility of the acid depending on the pH of the medium, which is important at the stage of acid precipitation in the process of its production, because of the zero charge point value can affect the solubility of a molecule at a given pH. Keywords: lignite, humic acids, composition, extraction, zero surface charge, pH indicator, acid-base titration. Corresponding author Savchenko V.V., e-mail: korbinity@gmail.com

Tracing baryon and electric charge transport in isobar collisions

It is of fundamental interest to understand the carrier of conserved quantum charges within protons and nuclei at high energy. Preliminary data from isobar collisions at RHIC reveal a scaled net-baryon to net-electric charge ratio (B/ΔQ × ΔZ/A) at midrapidity between 1.2 and 2, consistent with string junction model predictions. Here, we compute the initial stage scaled net-baryon to net-electric charge ratio for isobar collisions. Our model incorporates a realization of the string junction model and models the nuclear structure. Our predictions identify the baseline expectations for such measurement and quantify the impact of the nuclear structure.

Exploring the role of electrostatic deposition on inhaled aerosols in alveolated microchannels

Large amounts of net electrical charge are known to accumulate on inhaled aerosols during their generation using commonly-available inhalers. This effect often leads to superfluous deposition in the extra-thoracic airways at the cost of more efficient inhalation therapy. Since the electrostatic force is inversely proportional to the square of the distance between an aerosol and the airway wall, its role has long been recognized as potentially significant in the deep lungs. Yet, with the complexity of exploring such phenomenon directly at the acinar scales, in vitro experiments have been largely limited to upper airways models. Here, we devise a microfluidic alveolated airway channel coated with conductive material to quantify in vitro the significance of electrostatic effects on inhaled aerosol deposition. Specifically, our aerosol exposure assays showcase inhaled spherical particles of 0.2, 0.5, and 1.1 μm that are recognized to reach the acinar regions, whereby deposition is typically attributed to the leading roles of diffusion and sedimentation. In our experiments, electrostatic effects are observed to largely prevent aerosols from depositing inside alveolar cavities. Rather, deposition is overwhelmingly biased along the inter-alveolar septal spaces, even when aerosols are charged with only a few elementary charges. Our observations give new insight into the role of electrostatics at the acinar scales and emphasize how charged particles under 2 µm may rapidly overshadow the traditionally accepted dominance of diffusion or sedimentation when considering aerosol deposition phenomena in the deep lungs.

Thermally stabilized chondroitin sulfate-hemoglobin nanoparticles and their interaction with bioactive compounds

The preparation of nanoparticles (NPs) based on hemoglobin (Hb) with a fully biocompatible methodology is presented. The spontaneous formation of electrostatic complexes of Hb with chondroitin sulfate (CS) at pH 4 in the polysaccharide/protein mass ratio regime where charge neutrality is met leads to spherical nanostructures with monomodal hydrodynamic radii distribution in the range of 50–100 nm. The integrity of the electrostatic complexes is disturbed at pH 7 as the net electric charge of Hb is very low. Treating the NPs at mildly elevated temperature stabilizes them against the pH increase taking advantage of Hb's ability of unfolding and self-associating upon thermal treatment. The NPs surface charge is pH-tunable and changes from positive to strongly negative upon pH increase to 7 proving the presence of negative surface patches of Hb and CS segments in their exterior. The α-helix content of Hb does not change significantly by thermal treatment. The NPs are found to bind the bioactive compounds curcumin and β-carotene and are stable in solutions with high salt content. This investigation introduces a straightforward method to formulate Hb in NPs with possibilities in the nanodelivery of nutrients and drugs.

Electroactive Materials Surface Charge Impacts Neuron Viability and Maturation in 2D Cultures.

Since neurons were first cultured outside a living organism more than a century ago, a number of experimental techniques for their in vitro maintenance have been developed. These methods have been further adapted and refined to study specific neurobiological processes under controlled experimental conditions. Despite their limitations, the simplicity and visual accessibility of 2D cultures have enabled the study of the effects of trophic factors, adhesion molecules, and biophysical stimuli on neuron function and morphology. Nevertheless, the impact of fundamental properties of the surfaces to which neurons adhere when cultured in vitro has not been sufficiently considered. Here, we used an electroactive polymer with different electric poling states leading to different surface charges to evaluate the impact of the net electric surface charge on the behavior of primary neurons. Average negative and positive surface charges promote increased metabolic activity and enhance the maturation of primary neurons, demonstrating the relevance of considering the composition and electric charge of the culture surfaces. These findings further pave the way for the development of novel therapeutic strategies for the regeneration of neural tissues, particularly based on dynamic surface charge variation that can be induced in the electroactive films through mechanical solicitation.

Asymmetries in triboelectric charging: Generalizing mosaic models to different-material samples and sliding contacts

Nominally identical materials exchange net electric charge during contact through a mechanism that is still debated. `Mosaic models', in which surfaces are presumed to consist of a random patchwork of microscopic donor/acceptor sites, offer an appealing explanation for this phenomenon. However, recent experiments have shown that global differences persist even between same-material samples, which the standard mosaic framework does not account for. Here, we expand the mosaic framework by incorporating global differences in the densities of donor/acceptor sites. We develop an analytical model, backed by numerical simulations, that smoothly connects the global and deterministic charge transfer of different materials to the local and stochastic mosaic picture normally associated with identical materials. Going further, we extend our model to explain the effect of contact asymmetries during sliding, providing a plausible explanation for reversal of charging sign that has been observed experimentally.

Magnetized Black Holes: Interplay between Charge and Rotation

Already in the cornerstone works on astrophysical black holes published as early as in the 1970s, Ruffini and collaborators have revealed the potential importance of an intricate interaction between the effects of strong gravitational and electromagnetic fields. Close to the event horizon of the black hole, magnetic and electric lines of force become distorted and dragged even in a purely electro-vacuum system. Moreover, as the plasma effects inevitably arise in any astrophysically realistic environment, particles of different electric charges can separate from each other, become accelerated away from the black hole or accreted onto it, and contribute to the net electric charge of the black hole. From the point of principle, the case of super-strong magnetic fields is of particular interest, as the electromagnetic field can act as a source of gravity and influence spacetime geometry. In a brief celebratory note, we revisit aspects of rotation and charge within the framework of exact (asymptotically non-flat) solutions of mutually coupled Einstein–Maxwell equations that describe magnetized, rotating black holes.

The Universe: Search for Neutrino on Earth

Our planet is bombarded with trillions of particles, from Space from all direction called “Cosmic Rays”. The cosmic rays are made of tiny ‘elementary” particles such as photon, He, Neutrinos, Hydrogen and atomic nuclei have wide range of energies. Cosmic rays high energies suggest that they must be produced in the most energetic processes in the universe. As the cosmic rays particles have net electric charges they get deflected due to presence of geomagnetic fields during their travel and therefore do not travel in straight line. Cosmic rays particles can interact with matter and radiates at the sources to produced extremely particles called neutrino. Gamma rays radio Bursts of Electromagnetic energy in the form of gamma rays are the absolute, most energetic sources of energy known in the universe. The amount of energy that gamma ray bursts puts out in a few seconds is more than the Sun. every will in its entire life time.The neutrino, a fundamental elementary particles of nature, was born out of necessity to keep the conversvation of energy principle. In observed alpha,beta,and gamma decay. Although neutrinos are mot massless like photon of light, they have very special property. Neutrino are omnipresent in nature pass through every square centimeter of bodies without ever notice. Neutrino originate from events in the Universe such as Colloding of Black Holes,Gamma Ray Bursts from exploding stars and or violent event at core of distant Glaxies. A high energy of particles neutrino transform in to it’s particles lepton(electron,muon,ortauon).most accelerated Neutrino beam can also called muons , and few can create tauons. A detector which distinguished among these leptons can reveal the flavor of neutrino incident to charged particle current interaction because interaction involves the exchange of Boson the ‘target’ particle also change (e.g. neutron-proton).Netrinos detectors is a physics apparatus which is degined to study neutrinos, because neutrinos only weakly interact with other particles of matter, neutrino detector must very large to detect significant number of neutrinos. Confirmed extraterrestrial sources such as Sun,Super Nova1987A,

Flight Demonstration of Net Electric Charge Control of Aircraft Using Corona Discharge

This article reports on a flight experiment demonstrating the ability to control the net electrical charge of a small unmanned aircraft using ion emission from a corona discharge. The charging mechanism is based on the advection of ions produced by the corona discharge, leaving charge of the opposite polarity on the aircraft. An onboard high voltage power supply of up to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\pm$</tex-math></inline-formula> 15 kV was remotely operated to control the level of charging. The high voltage terminal of the power supply was connected to two thin corona wires placed above the aft surface of the wing in the spanwise direction, whereas the low voltage terminal was connected to the conductive airframe. Using this strategy, electric potentials of up to −30 and +23 kV relative to the environment were acquired by the aircraft, using positive and negative corona discharges, respectively. The study addresses the dependencies with power supply bias and wind speed. Possible applications of net charge control include risk reduction of aircraft-triggered lightning strikes, as explored by the authors in prior work, as well as a means of compensating for precipitation static and other sources of charging.

Study of a realistic model for electrically charged anisotropic stars with a simplest non-interacting quark matter equation of state

In this article a self bound quark star model that possesses some net electric charge is introduced. The quarks considered here are deconfined non-interacting Fermi gas. The solution has been found by solving Einstein-Maxwell field equations through MIT-bag equation of state and a metric potential. The obtained solution is further use to present a comparative studies of four compact stars 4U 1820-30, PSR J1903 + 327, Vela X-1 and PSR J1614-2230. The models are free from singularity, fulfil energy conditions, stability criteria and far within Buchdahl-Andreasson limit. Finally, we have predicted radii of these four compact objects.

Electrolyte adsorption in graphene and hexagonal boron nitride nanochannels

Understanding the dynamics of confined electrolytes through graphene-based channels is essential in multiple fields of science including: (a) developing novel artificial membranes for drug delivery, DNA sequencing and water desalination and (b) developing quantum nanoelectronic devices. In this work, All-Atom molecular dynamics simulations are used to study the adsorption of confined NaCl electrolyte solutions in graphene (GR), hexagonal boron nitride (hBN) and combined GR-hBN-GR nano-channels over a wide range of electrolyte concentrations c∈(0.1,2) M. The behavior of electrolytes confined between these surfaces is analyzed by evaluating the ionic density profiles, Potential of Mean Force (PMF), net charge density and integrated charge. Although neither graphene nor hBN has net electric charge, we observed significant changes in the ionic structure including the enhanced accumulation of sodium and the depletion in chloride density close to the hBN interfaces at low salt concentration. However, increasing the salt concentration leads to accumulation of chloride close to hBN surfaces. Two different types of hBN-GR junctions are considered in this study: a) shuffle (zigzag bonds) and (b) glide (parallel bonds). High adsorption of sodium and chloride ions near shuffle GR-hBN-GR surfaces is observed due to electrostatic attraction forces between the sodium and nitrogen atoms and between chloride and boron atoms at hBN–graphene junctions across zigzag bonds. This study reveals that GR-hBN-GR with shuffle interface is highly advantageous in adsorbing sodium and chloride ions than graphene and hBN alone. To the best of our knowledge, this is the first study that elucidates the interaction between monovalent electrolytes and GR-hBN-GR heterostructures in a confined medium.