Energy Spectrum Research Articles

Exploration of crystal structure, supramolecular organization, and computational studies of a novel pyrazole derivative: A structural and theoretical perspectives

An eminent challenge in contemporary medicine and pharmacy is the identification of powerful, biologically active, and benign anti-COVID drugs. The objective of this work is to synthesize 3-chloro-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxylic acid to investigate its properties using different spectroscopic methods. The crystal structure of the compound is determined using single-crystal X-ray diffraction methodology. Hirshfeld surface analysis was employed to evaluate the impact of intermolecular interactions on crystal packing. The interactions were visually depicted using 2D fingerprint plots, which highlighted the specific surface area associated with each interactant. Indications suggest that the crystal packing is mostly governed by C-H...O and N-H...O interactions, resulting in the formation of S(7) self-motif and R44(24) synthon, which greatly improve crystal stability. Density functional theory (DFT) was employed to better examine the structural and electrical characteristics. Computations were conducted at the 6–311+G(d,p) level to determine the optimal geometry, total energy, HOMO-LUMO gap, and vibrational spectra. The results showed a HOMO-LUMO gap of 3.092 eV, suggesting a moderate amount of stability. Bader et al. employed reduced density gradient (RDG) techniques and topological analysis, taking into account the quantum theory of atoms in molecules (QTAIM), to examine noncovalent interactions. Additionally, the molecule satisfies Lipinski's rule of five and exhibits encouraging pharmacokinetic activities. Additional in-silico investigations, including molecular docking, were conducted on the SARS-CoV-2 spike protein variation to assist in the advancement of enhanced vaccines and therapeutics.

Computer simulation of the electrical properties of carbon nanotubes encapsulated with alkali metal iodide crystals

The progress of modern electronics largely depends on the discovery and use of new materials with unique properties. One of such promising materials is carbon nanotubes. Their outstanding mechanical, thermal, and electrical properties open up new possibilities for creating small-sized electronic devices and improving the characteristics of existing materials by improving their manufacturing and processing technologies. One of the unique features of carbon nanotubes is their ability to encapsulate other atoms or molecules within their structure. This property can be used to create nanocontainers capable of protecting and transporting active substances or to change the electronic properties of nanotubes depending on the encapsulated substance. In this work, crystals of alkali metal iodides MI were encapsulated in carbon nanotubes with different structures and characteristics. The results obtained in terms of energy and density spectra of the state indicate the characteristics of conductivity due to an increase in energy and high peaks in the Fermi level. Thus, carbon nanotubes represent an important material for future developments in the field of nanoelectronics and nanotechnology.

A Twin Spiral Coil Phase Transfer Heat Exchanger for Storing Heat Should Be Designed and Tested in The Lab.

Abstract This in-depth study of thermal energy storage (TES) systems examines their function in resolving time, temperature, power, and location problems within the immense energy system design. With its incredible growth, TES creates a shadow over the future, projecting optimism for a better economy and more reliable energy infrastructure. The study is concentrated on a state-of-the-art heat exchanger that has circular double coils with various diameters, with a reliance on charging process amplification. The trial stage is decorated like a well-coordinated ensemble, integrating shell-and-tube design together with intense evaluation of varied tube morphologies, HTF flow designs, and protecting processes. The TES device effortlessly reveals its many components, such as a gas heater, control valves, a pump, a circular container with spiral HTF tubes, and a chorus of music. The PCM heat storage unit’s performance improved in two resonant cases that evaluated the effect of the HTF input temperature and coil charge in great detail. Case 2 and Case 1’s connections exhibit the significant heat absorption and PCM liquification by creating a web of various temperature differences while charging. With its improved temperature performance and straightforward design, Case 2 displays rapid removal and quicker charging periods. In addition, the study examines the HTF input parameters, which cast light on the constant HTF departure temperatures and demonstrate the importance of temperature during the charging opera. While the total energy storage rate rises with increasing temperatures, the expected scores are in accord with the mood fluctuations at the beginning and end of HTF. This review functions as a folder of vital insights, analyzing notes towards constructing PCM charging processes for higher energy storage efficiency - ultimately placing a limelight on the endless possibilities that TES systems predict in the present spectrum of energy uses.

Nonlinear light-output calibration of the oxygenated xylene scintillators used in OMEGA neutron time-of-flight spectrometers.

Neutron time-of-flight (nTOF) spectrometers are essential instruments for measuring and evaluating the performance of inertial confinement fusion implosions. The neutron spectrometers utilized for the OMEGA laser include two liquid-based scintillators, each consisting of a large volume filled with xylene that is coupled to four photomultiplier tubes. Analysis of the signal from these detectors requires detailed knowledge of the scintillator's light output, which is needed to fit the nTOF spectrum, from which the neutron energy spectrum is informed. The light output is nonlinearly proportional to the neutron energy, which, in turn, affects the interpretation of the neutron energy spectrum from a TOF signal. A recent campaign on OMEGA was performed to calibrate the xylene detectors and infer the shape of the light-output curve. The campaign utilized materials with increasing Z placed in the OMEGA target chamber to initiate scattering events with the 14MeV fusion neutrons. This process leads to the production of backscatter neutrons of varying energies that appear as peaks in the nTOF data. Simulations using a neutron transport code were combined with the measured deuterium-tritium neutron yields to calculate the expected backscattered neutron yields from the well-known scattering cross sections of each material. The neutron-energy dependent light output of the scintillator inferred from the experiment is compared to the light-output curve simulated with a neutron transport code for the following neutron energies: 1.5, 2.5, 6, and 14MeV.

Development of a compact magnetic spectrometer for use at the OMEGA Laser Facility and the National Ignition Facility.

Measurement of proton spectra is an important diagnostic for a variety of high energy density physics experiments. Current diagnostics are either not designed to capture the spectrum of low-energy protons or are unsuitable for high debris experiments. To bridge the gap, a new CR-39 based compact magnetic spectrometer (MagSpec) has been developed to measure proton spectra in the 1-20MeV energy range, with a particular focus on the low-energy (1-6MeV) spectrum, for use in experiments at the OMEGA Laser Facility and the National Ignition Facility (NIF). In the MagSpec diagnostic, protons of different energies are dispersed as they pass through a magnetic field before impinging on a differentially filtered CR-39 surface, resulting in a spatial distribution of CR-39 tracks that corresponds to the energy spectrum. In this paper, we discuss details of the design and implementation of MagSpec on the NIF and OMEGA.

Eddy viscosity enhanced temporal direct deconvolution model for temporal large-eddy simulation of turbulent channel flow

In this work, a novel eddy viscosity enhanced temporal direct deconvolution model (TDDM) is proposed for temporal large-eddy simulation (TLES) of turbulent channel flow at large filter widths. To improve the accuracy of the constant eddy viscosity (CEV) model, particularly in the near-wall region, a damping function is incorporated to refine its performance. Moreover, a spatial filtering strategy is introduced to reduce the aliasing errors associated with the computation of subfilter-scale (SFS) stress, thereby enhancing numerical stability. In the a posteriori study, the accuracy of the CEV model is assessed comprehensively by comparing the TLES results with corresponding temporally filtered direct numerical simulation data. The results demonstrate that the CEV-enhanced TDDM provides accurate predictions across various statistical properties of velocity, instantaneous flow structures, kinetic energy spectra, and SFS energy fluxes. The coefficient sensitivity analysis of the CEV model reveals that the model coefficient significantly influences low Reynolds number flows, while its impact on high Reynolds number flows is relatively small. TLES on coarse grids demonstrate that the CEV-enhanced TDDM exhibits strong robustness and accuracy at different grid resolutions. Additionally, the CEV-enhanced TDDM in high Reynolds number flows is stable and accurate at remarkably large filter widths.

Precise Measurements of TeV Halos around Geminga and Monogem Pulsars with HAWC

We present the most precise measurements to date for the spatial extension and energy spectrum of the γ-ray region between a pulsar’s wind nebula and the interstellar medium, better known as the halo, present around Geminga and PSR B0656+14 (Monogem) using ∼2398 days of >1 TeV data collected by the HAWC observatory. We interpret the data using a physically motivated model for the diffuse γ-ray emission generated from positrons and electrons (e±) injected by the pulsar wind nebula and inverse Compton scattering with interstellar radiation fields. We find the morphologies of the regions inside these halos are characterized by an inhibited diffusion that are approximately three orders of magnitudes smaller than the Galactic average. We also obtain the e± emission efficiencies of 6.6% and 5.1%, respectively, for Geminga and Monogem. These results have remarkable consequences for the study of the particle diffusion in the region between the pulsar wind nebulae and the interstellar medium, and for the interpretation of the flux of positrons measured by the AMS-02 experiment above 10 GeV.

Novel Synergistic Mechanism of Oxalic Acid -CMC at the Solid-Liquid Interface: For Selective Depression of Talc from Chalcopyrite

Flotation separation of chalcopyrite and talc is challenging due to their surface hydrophobicity, requiring a selective depressant for talc to achieve high-quality copper concentrate. This study is the first to use oxalic acid (OA) and carboxymethyl cellulose (CMC) as combined depressants for talc, and investigated the depression mechanism through flotation tests and various analysis techniques. Mixed minerals-flotation results showed that with 60+60 mg/L OA+CMC, talc was strongly depressed (10.16% recovery) with slight chalcopyrite (86.54% recovery) impact. The selective depression effect of OA+CMC was further verified through actual ore flotation experiments. Contact angle and zeta potential test indicated that OA+CMC significantly increased the hydrophobicity difference between talc and chalcopyrite surfaces. Adsorption capacity and atomic force microscope(AFM) results further confirmed that OA promotes CMC adsorption on talc surface, forming a dense CMC layer, whereas CMC adsorption on chalcopyrite was relatively low. Scanning electron microscope energy spectrum spectroscopy (SEM-EDS), fourier transform infrared Spectroscopy(FTIR), and molecular dynamics (MD) results indicate that the synergistic depression mechanism of OA and CMC involves the formation of multiple adsorption layers at the solid-liquid interface, leading to an increased presence of hydrophilic groups on the talc surface, which results in its depression.

The fracture and perforation failure analysis of downhole tubes

：The downhole tubes were fractured and perforated after 5 years of shut-in due to high water cuts. This study employs a comprehensive array of analytical techniques to investigate the mechanisms behind fractures and perforations. Utilizing non-destructive testing (NDT), direct reading spectrometer, tensile strength testing machine, impact testing machine, optical microscope (OM), macroscopic fracture morphology observation, scanning electron microscope (SEM) and energy spectrum analysis (EDS), and sulfide stress corrosion cracking (SSCC) was studied. The reason for the fracture of the tubing is that under the condition of low pH value, high hydrogen sulfide environment, the tubing is fractured due to stress concentration caused by cracks in the outer thread relief groove. The perforation of the inner tube wall was caused by gradual wall thickness reduction under the influence of H2S, CO2, and Cl−, resulting in fouling and eventual perforation. To prevent tube corrosion during long-term shut-in, it is recommended to inject crude oil or diesel into the well.

Theory and simulation of the electrothermal instability in pulsed power electrode plasmas

Linear theory of the electrothermal instability is rederived and applied to conditions expected in pulsed power electrode surface plasmas comprised of either hydrogen or carbon. The analysis includes losses due to Coulomb collisions, inelastic processes derived from a collisional radiative model, and thermal conduction. The predicted growth rates are relevant for pulse durations typical of pulsed power devices. Linear theory reveals that the growth rate peaks at a characteristic wavenumber kmax, which is dependent on electron current density Je, number density ne, and temperature Te. Analysis of nonlinear simulations finds that saturation occurs as a result of Coulomb collisions, which limit the electron temperature to go no lower than the ion temperature such that Te≳Ti. When the instability is driven by a perturbation with broadband sinusoidal content, the peak in the energy spectrum nonlinearly shifts away from kmax toward smaller wavenumbers (or longer wavelengths) during saturation. The ETI is shown to be capable of driving plasma filaments with perturbed current densities and electron temperatures that exceed the initial, steady-state values.

Short baseline neutrino anomalies at stopped pion experiments

Stopped-pion experiments that measure coherent elastic neutrino-nucleus scattering (CEνNS) are sensitive to sterile neutrinos via disappearance. Using timing and energy spectra to perform flavor decomposition, we show that the delayed electron neutrino component provides an independent test of short-baseline anomalies that hint at ~ eV-mass sterile neutrinos. Dedicated experiments will be sensitive to nearly the entire sterile neutrino parameter space consistent with short-baseline data.

Quasi-monoenergetic ion acceleration and neutron generation from laser-driven transverse collisionless shocks

Experiments using the OMEGA EP laser system were performed to study collisionless shock acceleration of ions driven by the interaction of a relativistically intense laser pulse with underdense plasma. The energy spectrum of accelerated ions in the direction transverse to laser propagation is measured to have several narrow-band peaks which are quasi-monoenergetic with a typical energy bandwidth of 3%. In deuterium plasmas, these ions generate a significant number of fast fusion neutrons. Particle-in-cell simulations confirm that these ions were accelerated by the interaction of transverse shocks and that the appearance of quasi-monoenergetic spectral features depends on the growth of an ion-electron two-stream instability during the interaction.

Energetic seed particles in self-consistent particle acceleration modeling at interplanetary shock waves

Aims. The study investigates the relevance of the seed particle population in the results of particle acceleration in interplanetary shock waves, when wave–particle interactions are treated self-consistently. Methods. We employed the SOLar Particle Acceleration in Coronal Shocks (SOLPACS) model, which is a proton acceleration simulation in shocks with self-consistent nonlinear wave–particle interactions. We compared a suprathermal monoenergetic injection with a two-component injection, including the suprathermal monoenergetic component and a broad-spectrum energetic component corresponding to the observed background particle spectrum. Energetic particles in the beginning of the simulation could increase the local wave intensities sufficiently to increase the rate of acceleration for injected particles and even reshape the resulting particle energy spectra and spatial distributions. The resulting particle energy spectra, particle spatial distributions, and wave intensity spectra are compared to observations made by Solar Orbiter’s instrument suite of the 2021 October 30 energetic storm particle (ESP) event to evaluate the relevance of the seed particle population in the acceleration model. Results. The energetic component of the seed particle population shortens the needed acceleration time for particles and enhances the tail of the spectrum to a level that matches the observations. The highest compared energies (> 1 MeV) match only when an energetic component is included in the seed particle population. The wave intensities and spatial distributions, on the other hand, showed no significant differences with the monoenergetic and two-component injection. While the simulated and observed wave intensities match within five minutes before the shock passing, the simulated wave field is too intense farther out from the shock, probably due to a lack of wave damping and/or decay processes in the simulation, leading to particles being slightly overly trapped to regions closer to the shock.

SiO2 sputtering by low-energy Ar+, Kr+, and Xe+ ions in plasma conditions

Modern plasma technologies applied for nm-size devices require localizing ions’ impact within up to atomic layer to avoid uncontrollable damage of underlying structures. The decrease in energy of ions incident on a surface is one of the ways to achieve this. In this work, SiO2 sputtering by Ar+, Kr+, and Xe+ ions at energies of 20–200 eV was studies in the low-pressure ICP-discharge at a plasma density typical for plasma processing. The rf-bias waveform tailoring due to high discharge asymmetry allowed generating and controlling ion narrow energy spectrum with FWHM 5±2 eV. Real time in-situ control over ion composition and flux as well as sputtering rate provided accurate determination of the SiO2 sputtering yield, . It is shown that at ion energy above ∼70 eV, the “classical” kinetic sputtering mechanism prevails. In this case, rapidly grows with ion energy, while decreasing with the decrease in ion mass. Below ∼70 eV, the change of is strongly slow down while the sputtering yield still stays high enough (>10-3), demonstrating the plasma impact on the sputtering mechanism. The obtained trends of under the plasma exposure are discussed in light of possible SiO2 surface modification studied by AFM and angular XPS analysis.

Study on Characteristics of Epoxy Resin-Based Plastic Scintillators for Detectors with Simulation Using Monte Carlo Code

Abstract To determine the presence of radioactive materials emitting gamma rays entering or exiting nuclear facilities, ports, airports, international borders, or other strategic locations, radiation portal monitors (RPMs) capable of detecting such gamma radiation need to be installed in these places. National Research and Innovation Agency of Indonesia (BRIN) is currently developing RPMs with detector components made of plastic scintillator based on epoxy resin and augmented with aromatic fluorescent materials to produce visible light, which is the working range of the photomultiplier tube (PMT) or silicon photomultiplier (SiPM). This research aims to study the characteristics of the gamma photon radiation energy spectrum from Co-60, Cs-137, and Ir-192 sources in an epoxy resin plastic scintillator and study the absorbed dose of the scintillator to gamma photon radiation energy from Co-60, Cs-137, and Ir-192 sources as a function of source distance and incidence angle of gamma rays with simulations using the MCNPX code. The scintillator is modeled in the form of a cylinder with a diameter of 5 cm and a height of 5 cm. To simulate the gamma photon radiation energy spectrum in the scintillator, the F4 tally was used and to simulate the scintillator absorbed dose, the F6 tally was used. This simulation used gamma sources of Co-60, Cs-137, and Ir-192 of 1 mCi each. These characteristics of the epoxy resin plastic scintillator have been successfully simulated. Data on the characteristics of epoxy resin plastic scintillators is important to know and study as supporting data in making plastic detectors as part of the manufacture and development of RPM.

Contributions of Cosmic-Ray Components to the HPGe Gamma Spectrometer Background Spectrum within the 0°-45° Zenith Angle Range

This study investigates the contributions of various cosmic-ray-induced components to the energy response of a High-Purity Germanium (HPGe) gamma spectrometer within the 0°-45° zenith angle range. The analysis focuses on muons, neutrons, protons, electrons, positrons, and photons. It also examines the impact of particle showers induced by muons interacting with the lead chamber and reaching the HPGe detector. Utilizing the GEANT4 simulation toolkit, we provide a detailed examination of these components' influence on the spectrum. The results confirm that within this zenith angle range, muons account for approximately 91% of the recorded cosmic-ray induced energy spectrum and contribute 54.6% to the overall cosmic-ray-induced background spectrum. The study also highlights the significant role of showers, especially those resulting from muon interactions with the lead shielding, in shaping the low-energy spectrum below 3 MeV.

Correlation of pinch voltage with ion angular emission characteristics at varying D2 gas filling pressures in a low energy plasma focus device

Acceleration of deuterium ions to high energies and their anisotropic emission has been tried to be understood from pinch voltage (Vp) perspectives using 3.1 kJ plasma focus device. The D2 gas filling pressure was varied from 2 to 4 mbar at an operating energy of 1.1 kJ (10 μF, 15 kV). The pinch voltage was seen to be varying with filling pressure and it was found to be maximum 16.26 ± 0.56 kVat 3 mbar. The most probable energy (MPE) of deuterium ions followed the pinch voltage and maximum 11.36 ± 0.68 keV and 6.82 ± 0.41 keV were measured in the axial and radial direction respectively at 3 mbar. Maximum energies of deuterium ions were observed to be in the range of 700 to 1000 keV. Correspondence between MPE and the pinch voltage as well as higher measured maximum energy than the value eVp suggested m=0 sausage instability might be the principal mechanism of ion acceleration coexisting with other acceleration mechanism. The energy spectrum suggested that number of high energetic deuterium ions decreases faster in the axial direction than in the radial direction. This report discusses in details about the experimental observations and various other aspects of the measurements.

Very High-energy Gamma-Ray Episodic Activity of Radio Galaxy NGC 1275 in 2022–2023 Measured with MACE

The radio galaxy NGC 1275, located at the central region of Perseus cluster, is a well-known very high-energy (VHE) gamma-ray emitter. The Major Atmospheric Cherenkov Experiment Telescope has detected two distinct episodes of VHE (E > 80 GeV) gamma-ray emission from NGC 1275 during 2022 December and 2023 January. The second outburst, observed on 2023 January 10, was the more intense of the two, with flux reaching 58% of the Crab Nebula flux above 80 GeV. The differential energy spectrum measured between 80 GeV and 1.5ṪeV can be described by a power law with a spectral index of Γ = −2.90 ± 0.16stat for both flaring events. The broadband spectral energy distribution derived from these flares, along with quasisimultaneous low-energy counterparts, suggests that the observed gamma-ray emission can be explained using a homogeneous single-zone synchrotron self-Compton model. The physical parameters derived from this model for both flaring states are similar. The intermediate state observed between two flaring episodes is explained by a lower Doppler factor or magnetic field, which subsequently returned to its previous value during the high-activity state observed on 2023 January 10.

Hydrodynamic energy flux in a many-particle system

In this letter, we demonstrate energy transfers and thermalization in an isolated ensemble of realistic gas particles. We perform a grid-free classical molecular dynamics simulation of two-dimensional Lenard-Jones gas. We start our simulation with a large-scale vortex akin to a hydrodynamic flow and study its non-equilibrium behavior till it attains thermal equilibrium. In the intermediate phases, small wavenumbers (k) exhibit E(k)∝k−3 kinetic energy spectrum, whereas large wavenumbers exhibit E(k)∝k spectrum. Asymptotically, E(k)∝k for the whole range of k, thus indicating thermalization. These results are akin to those of Euler turbulence despite complex collisions and interactions among the particles.

Biological effectiveness of combined exposure to neutrons and gamma radiation applied in two orders of sequence: Relevance for biological dosimetry after nuclear emergencies

ObjectiveAfter a nuclear detonation, people will be exposed to varying mixtures of neutrons and gamma radiation and the biological effectiveness of mixed beams is not well known. Additionally, it is not known how far both radiation types interact, a question that is relevant for generating calibration curves for the purpose of biological dosimetry. The objective of this study was to investigate the potential impact of two different combinations of neutron and gamma radiation on gene expression and dicentric chromosomes in peripheral blood mononuclear cells (PBMC). MethodsWhole blood from 3 human donors was exposed to neutrons with an energy spectrum similar to that of the Hiroshima uranium bomb, to gamma radiation from a 60Co source and to a 50:50 combination of both radiations, given in two orders of sequence. In all cases the total doses were 0.5, 0.75 and 1.0 Gy. Dicentric chromosomes were analyzed by light microscopy and the expression of six known radiation-responsive genes BBC3, CDKN1A, FDXR, GADD45A, MDM2, and XPC were analyzed by RT-qPCR. ResultsPer unit dose, exposure to neutrons lead to a higher level of dicentrics and gene expression as compared to gamma radiation. Dose-response relationships for both endpoints were linear, allowing calculating the expected outcome of combined exposure by arithmetic. For dicentric chromosomes, the RBE values for 60Co→neutrons, neutrons→60Co and neutrons were 4.05, 3.62 and 7.30 respectively. For gene expression the RBE values were gene-specific, but showed values in the range of 1.14–3.01 for 60Co→neutrons, 1.33–2.68 for neutrons→60Co and 1.39–3.91 for neutrons. ConclusionsThe results demonstrate that combined exposure to neutrons and gamma radiation, regardless of the order of sequence, leads to an additive response at both endpoints. This indicates that calibration curves for mixed beams can be constructed from dose response relationships of the single beam components.