Constant Energy Research Articles

Regulating Charge Separation Via Periodic Array Nanostructures for Plasmon-Enhanced Water Oxidation.

Plasmonic resonance intensity in metallic nanostructures plays a crucial role in charge generation and separation, directly affecting plasmon-induced photocatalytic activity. Engineering strategies to enhance plasmonic effects involve designing specific nanostructures, such as triangular nanoplates with sharp corners or dimer nanostructures with hot spots. However, these approaches often lead to a trade-off between enhanced plasmonic intensity and resonance energy, which ultimately determines local charge density and photocatalytic performance. Here, inspired by theoretical predications, it is shown that a flexibly controlled plasmonic photocatalyst, consisting of an ordered array of Au nanoparticles on a SrTiO3 surface, exhibits an enhanced surface plasmon resonance (SPR) intensity while maintaining a constant SPR resonant energy, due to the presence of surface lattice resonance. This trade-off results in improved charge separation efficiency and an increase in local charge density at catalytically active sites, as verified by theoretical simulations, surface photovoltage microscopy, and ultrafast transient absorption spectroscopy. Moreover, the optimized periodic photocatalyst shows a 7-fold increase in water oxidation activity over disordered nanostructures. This work provides a novel approach for balancing the intensity and energy of SPR, which will contribute to optimizing photocatalytic activity on plasmonic platforms.

Исследование гидрофильности поверхности металлических материалов, модифицированных ультрафиолетовым лазерным излучением

Introduction. Surface modification using laser radiation is a promising direction in the field of creating new technologies for treatment metal materials, including those for medical purposes. The ability of lasers to change the surface characteristics of a material and, consequently, its interaction with the environment has attracted great interest among researchers. Despite numerous recommendations for the use of laser surface treatment, there is still lack of systematic and detailed studies on the influence of parameters on the structural-phase state and properties of the modified surface, especially concerning ultraviolet laser exposure. The purpose of this work is to study the hydrophilicity of the surface of TiNi alloy and stainless steel after UV laser treatment. Materials and methods of the study: experimental samples made of TiNi (TN-10) alloy and 12KH18N9T (AISI 321) stainless steel were locally (beam diameter 0.5 cm) exposed to a solid-state Nd:YAG laser at the wavelength of 266 nm, with a pulse duration of ~ 5 ns, and pulse repetition rate of 10 Hz. The material was exposed to a constant output radiation energy density of 0.1 J/cm2, with a change in the exposure duration from 10 to 600 s. Before and after UV laser treatment, the wettability of the material surface and free surface energy were determined. The structure, elemental and phase composition, and surface topography of TiNi and steel were studied using scanning electron microscopy with the determination of the elemental composition by energy-dispersive spectroscopy, X-ray phase analysis, and profilometry. Results and discussion. Ultraviolet laser treatment of the surface of TiNi alloy and steel samples leads to an increase in their hydrophilicity. In the initial state, the contact angle of wetting is ≈75° for both materials, and after ultraviolet laser treatment it decreases to ≈11-13° for TiNi and to ≈22° for steel. The phase composition of steel does not change during laser treatment, and phases belonging to oxides are recorded on the surface of TiNi after 420 seconds of treatment. Ultraviolet laser treatment of TiNi alloy and steel leads to an increase in free surface energy, a change in the ratio of its components (a decrease in the dispersed component and a significant increase in the polar component), an increase in the oxygen content on the surface of both materials. With long laser exposure times (more than 300 seconds), microcracking occurs on the surface of the processed material, leading to an increase in roughness. The change in the surface topography (roughness) of TiNi alloy does not have a noticeable effect on the wettability of the surface of metal materials, and for steel samples, there is an insignificant tendency to reduce the contact wetting angle with increasing roughness. The degree of hydrophilicity of metal materials, characterized by the contact wetting angle, increases with an increase in the duration of laser exposure due to saturation of the surface with free oxygen and an increase in free surface energy (its polar component). Based on the studies, it can be concluded that ultraviolet laser treatment is an effective way to change the wettability of metal materials.

Linear and Nonlinear Optical Characteristics of Basic Fuchsin-Doped Polyvinyl Alcohol Films for Flexible Optoelectronics

Abstract Polyvinyl alcohol (PVA) containing different levels of basic fuchsine (BF) was prepared using the solution casting method. Characterization via Fourier-transform infrared spectroscopy detailed changes in functional groups within the PVA/BF composites, indicates the hydrogen bonding between OH group of PVA and BF molecules. Optical investigations spanning the 190-2500 nm range demonstrated UV blocking properties in prepared PVA/BF composites (fromn 2.05 to 2.56 eV and from 4.08 to 6.32 eV). Moreover, the studies on optical band gap indicated a decrease with increased BF concentrations, reflecting altered electronic transitions within the prepared composites. The study also employed the single oscillator model provided by Wemple-DiDomenico to elucidate refractive index variations. After incorporating BF dye into the PVA polymer, the values of the dielectric constant as the frequency approaches infinity (ε∞), the dielectric constant of lattice (εL), dispersion energy (Ed), and oscillator energy (Eo) in PVA/BF composite samples showed an increase. Moreover, the nonlinear optical properties, including optical susceptibility and nonlinear refractive index were investigated and discussed. These findings underscore the versatility of PVA doped with BF for various applications including optical filters, and solar cell devices.

Declined S1 but Constant T1 Energy: Thermally Activated Delayed Fluorescence with Triplet Blocking Effect.

Thermally activated delayed fluorescence (TADF) molecules have been widely investigated in organic light emitting diodes (OLED), organic lasing, etc. Small singlet-triplet energy gap (ΔEST) and high radiative rate constants (kF) are highly desired to utilize triplet excitons efficiently and are beneficial to reduce efficiency roll-off of devices of OLED devices. The prevalent TADF molecules are via donor-acceptor molecular design, for which the decreasing of the ΔEST is often at the expense of reducing the kF. Herein, we demonstrated a new ΔEST modulation approach to construct TADF with high kF, based on triplet blocking effect, i.e., the extension of π-conjugation of a triplet constrainer (IB) leads to a gradually red-shifted S1 but a constant T1 energy and therefore reduced ΔEST controlled from monomer (IB), monomer-linker (IB-BF2), to dimer of IB-BF2-IB. The natural transition orbital analysis indicates that S1 state is delocalized while T1 state is localized as confirmed by time resolved electron paramagnetic resonance spectroscopy. Therefore, the ΔEST is reduced from 0.60 eV, 0.46 eV to 0.25 eV, while keeping faster radiation rate (around 108 s-1) than that of conventional donor-acceptor molecules (106∼107 s-1). As a result, the emission mechanisms are regulated from fluorescence for IB, phosphorescence/TADF dual emissions for IB-BF2 to TADF for IB-BF2-IB. This paper proposed a new approach of ΔEST modulation and a new type of TADF molecule with high radiation rate, which is crucial for fundamental photophysics as well as material science.

Declined S1 but Constant T1 Energy: Thermally Activated Delayed Fluorescence with Triplet Blocking Effect

AbstractThermally activated delayed fluorescence (TADF) molecules have been widely investigated in organic light emitting diodes (OLED), organic lasing, etc. Small singlet‐triplet energy gap (ΔEST) and high radiative rate constants (kF) are highly desired to utilize triplet excitons efficiently and are beneficial to reduce efficiency roll‐off of devices of OLED devices. The prevalent TADF molecules are via donor‐acceptor molecular design, for which the decreasing of the ΔEST is often at the expense of reducing the kF. Herein, we demonstrated a new ΔEST modulation approach to construct TADF with high kF, based on triplet blocking effect, i.e., the extension of π‐conjugation of a triplet constrainer (IB) leads to a gradually red‐shifted S1 but a constant T1 energy and therefore reduced ΔEST controlled from monomer (IB), monomer‐linker (IB‐BF2), to dimer of IB‐BF2‐IB. The natural transition orbital analysis indicates that S1 state is delocalized while T1 state is localized as confirmed by time resolved electron paramagnetic resonance spectroscopy. Therefore, the ΔEST is reduced from 0.60 eV, 0.46 eV to 0.25 eV, while keeping faster radiation rate (around 108 s−1) than that of conventional donor‐acceptor molecules (106∼107 s−1). As a result, the emission mechanisms are regulated from fluorescence for IB, phosphorescence/TADF dual emissions for IB‐BF2 to TADF for IB‐BF2‐IB. This paper proposed a new approach of ΔEST modulation and a new type of TADF molecule with high radiation rate, which is crucial for fundamental photophysics as well as material science.

Estimation of Quantitative Inertia Requirement Based on Effective Inertia Using Historical Operation Data of South Korea Power System

In low-inertia systems with a high penetration of renewable energy, the rotational kinetic energy and inertia constant are significant factors in determining frequency stability. The energy released owing to the frequency decrease during contingency represents a portion of the inertia that a synchronous machine possesses in the normal state. However, when securing inertia or planning additional resources to secure frequency stability, inertia in the normal state is analyzed as the standard rather than the amount of energy released during a fault. Therefore, in this paper, we define the actual energy emitted from a synchronous machine as Effective inertia. In order to evaluate Effective inertia in various operating conditions, we conducted a comprehensive review on approximately 24,627 cases from the years 2019, 2020, and 2021. As a result, in systems with low rotational kinetic energy, both low- and high-frequency nadirs were observed, indicating high uncertainty. However, Effective inertia presented a consistent trend regarding the energy release aligned with the minimum frequency. For instance, the rotational kinetic energy required to satisfy the frequency standard was 23 GWs, while the required Effective inertia was 858 MWs. We emphasize that securing inertia based on rotational kinetic energy includes additional imaginary energy that does not contribute to frequency, resulting in an energy requirement greater than that needed for Effective inertia. Therefore, in order to secure the frequency stability of the future system, the actual required energy amount based on Effective inertia will be presented and utilized in the inertia market and FFR (Fast Frequency Response) resource design.

Enhanced Linear and Nonlinear Optical Characteristics of Cerium (Ce) Doped ZnO Film

ZnO and Ce-doped ZnO films with different doping concentrations (2, 4, and 6 wt%) were produced via SILAR technique, and the influence of the Ce amount on the structural, morphological, linear and nonlinear optical properties were examined in detail. Structural analyses conducted using X-ray diffraction (XRD) and Raman spectroscopy revealed the formation of hexagonal wurtzite pristine ZnO and Ce-doped ZnO nanostructures. The CeO2 phase was observed for only Ce6:ZnO samples by the XRD and Raman analyses. The morphological analyses were performed with a Scanning Electron Microscope (SEM), and it was found that the grain size decreased with Ce doping. The band gap energies decreased from 3.18eV to 2.67eV with increasing dopant (Ce) amount and increasing Urbach energy (EU). The dislocation density values (XRD) were calculated as 1.68x , 2.22x , 4.52x , and 8.65x nm-2 for ZnO, Ce2:ZnO, Ce4:ZnO, and Ce6:ZnO, respectively, which is consistent with the increasing Urbach energy. The optical characteristics such as excitation and absorption coefficient, refractive index, dielectric constant, optical conductivity, the volume (VELF) and surface (SELF) energy loss functions were estimated. The third- order nonlinear susceptibility, and the nonlinear refractive index were calculated using Miller's generalized rule with linear refractive index and Wemple-DiDomenico (W-D) model. The χ(3) and n2 values increased with Ce influence compared to undoped ZnO film. Various methods have been used to obtain Ce:ZnO films, but the low-cost SILAR method has not been reported before, and the films produced via this method showed suitable behaviours for optoelectronic devices and nonlinear applications.

DFT and molecular docking research on the effects of lichen metabolites

Breast cancer remains a significant public health problem worldwide and requires the investigation of new treatment methods. Lichens, symbiotic organisms rich in bioactive compounds, have emerged as promising sources of natural anticancer agents. This study investigates the anticancer effects of lichen metabolites derived from Xanthoparmelia wyomingica on breast cancer cell lines MCF-7 and MDA-MB231. High-performance liquid chromatography (HPLC) was used to measure specific lichen acids in the extract; this revealed the presence of Gyrophoric acid (GA), Norstictic acid (NA), Protocetraric acid (PA), Stictic acid (SA), and Usnic acid (UA). Cytotoxicity analysis showed significant reductions in cell viability, particularly in the MDA-MB231 cell line, with IC50 values ranging from 21.67 to 36.71 µg/mL. Molecular docking studies elucidated the interaction mechanisms between these metabolites and target proteins, highlighting NA as the most promising compound with the lowest binding energy (−9.5 kcal/mol) and inhibition constant (0.108755 μM). ADMET analysis of the molecules was then performed. Molecular electrostatic potential (MEP) and HOMO-LUMO analysis provided further information about the reactivity and electron distribution of the compounds. This study has the potential to provide novel therapeutic agents for breast cancer to tackle the increasing resistance to conventional therapies. Lichen metabolites enable the development of effective therapies in targeting aggressive subtypes such as triple-negative breast cancer with limited treatment options. This research highlights the anticancer properties of lichen metabolites and their potential in the development of innovative strategies for breast cancer treatment. The findings offer a promising avenue to address the urgent need for effective therapies in oncology.

Electronic properties, optical transparency and transport properties of the p-type transparent conductive oxide family Sn2-xPbxNb2O7 (x = 0, 0.5, 1.0, 1.5, and 2.0): a density functional theory study.

Based on density functional theory, we introduce a novel family of p-type transparent conductive oxides, Sn2-xPbxNb2O7 (x = 0, 0.5, 1.0, 1.5, and 2.0), and confirm their thermodynamic and mechanical stabilities through detailed calculations of free energy, mixing enthalpy and elastic constant. We discuss how Pb atom substitution affects the lattice structure, band structure, electronic properties, optical properties, and transport properties of materials in this family and reveal the regulatory mechanisms. The antibonding coupling of Sn-O1 and Pb-O1 contributes to the formation of p-type characteristics. The highly dispersive Sn(Pb)5s(6s) band is formed when the O2-Sn(Pb)-O2 bonding angle is close to 180°, and the large elastic constant and small deformation potential energy all contribute to the high mobility in the system. Based on the evaluation of three empirical criteria, and incorporating the computational analysis of optical and transport properties, we determined that compounds with x = 1.0 and 1.5 are excellent intrinsic p-type transparent conductive materials with high valence band maximum (VBM) positions. The elevated VBM positions in these materials pave the way for significant enhancements in p-type conductivity via acceptor doping techniques.

Thermal degradation of 18 amino acids during pyrolytic processes

Biomass pyrolysis greatly impacts climates, ecosystem dynamics, air quality, human health, global carbon and nitrogen cycle. The emissions of nitrogen-containing compounds from biomass pyrolysis highly depend on the protein nitrogen existing in biomass. However, the quantitative kinetic information, including the rate constant and apparent activation energy of individual amino acid induced by pyrolysis are still yet to be well-constrained. Towards this, we performed a series of controlled pyrolysis experiments where 18 equimolar free amino acids standard mixtures were pyrolyzed under ambient oxygen at temperatures between 160 and 240 °C. Additionally, straw samples were pyrolyzed to understand the mechanism of combined amino acids in protein liberation to free amino acids during pyrolytic processes. Our observations indicated that an increase in heating duration and temperature promote the degradation of free amino acids. Further, the heating stability of the 18 examined amino acids varied, which could be related to the length and functional groups present in their side chains. Our result shows that the degradation processes of all examined 18 amino acids followed irreversible first-order reaction kinetics in air within the given temperature range, with their activation energy ranging from 88.5 to 137.44 kJ mol−1. The distinct distribution patterns of both combined and free amino acids in aerosol samples from straw pyrolytic processes were obtained. The kinetic information of amino acids garnered herein helps to elucidate the transformation mechanisms of nitrogenous compounds during biomass burning.

Enhanced Energy Storage Properties of PP/PA11 Dielectric Composite Films With PP‐g‐MAH as Compatibilizer

ABSTRACTAs an energy storage capacitor film material, polypropylene (PP) suffers from its low dielectric constant and limited energy density. To overcome the defects of pure PP, the PP‐based all‐organic composite films with multiple interfaces have been constructed to enhance the dielectric and energy storage properties. In this research, PA11 was used to blend with PP with polypropylene grafted maleic anhydride (PP‐g‐MAH) as compatibilizer. The prepared PP/PP‐g‐MAH/PA11 composites formed the typical “sea‐island” structure and double interfaces between PP/PP‐g‐MAH and PP‐g‐MAH/PA11. The higher molecular polarity of PP‐g‐MAH, PA11, and interfacial polarization significantly increases the dielectric constant of the composite films. Furthermore, the formation of interface traps suppressed the migration of charge carriers, resulting in lower leakage current and higher breakdown strength of the PP/PP‐g‐MAH/PA11 composite films. Density functional theory (DFT) simulation further proved the confinement of space charges. Energy storage results showed the optimal PP/PP‐g‐MAH/PA11‐2 film achieved high energy density (4.49 J/cm3) and excellent charge/discharge efficiency (97.4%), which behaved good application prospect in the field of thin film capacitors.

Intensification of extraction of bioactive compounds from pomegranate peel using an ultrasound-microwave assisted extraction approach: Parametric optimization, kinetics and thermodynamics

The expansion of fruit processing industries results in a significant amount of by-products, including peels, seeds, skins, pomace, and rinds, which are rich in bioactive compounds like polyphenols, flavonoids, carotenoids, and dietary fiber. These processing by-products are often deemed of minimal value relative to the processed fruit, largely due to the absence of efficient extraction methods. In this study, ultrasound-microwave assisted extraction (UMAE) technology was used to extract bioactive components from pomegranate (Punica granatum L.) peel using ethanol as a solvent. The influence of the combined power (ultrasonic 200 W + microwave 100–300 W), extraction time (10–30 min.), liquid to solid ratio (LSR) (20:1–60:1 mL/g) and solvent concentration (30–70 vol%) on extraction yield, total phenolic content (TPC), total flavonoids content (TFC) and 1,1-diphenyl-2-picrylhydrazyl- radical scavenging activity (DPPH-RSA) was investigated. The optimal conditions using response surface methodology (RSM) for UMAE were found to be an ultrasonic power of 150 W, LSR of 50:1 mL/g, a solvent concentration of 60 %, and an extraction time of 15 min. Under the optimized conditions, 64.964 % of extraction yield, 152.089 mg GAE/g DW of TPC, 38.566 mg QE/g DW and 88.892 % of DPPH-RSA were obtained. The concentration–time data were examined using a second-order rate kinetic model to calculate the extraction constant and activation energy. The thermodynamic analysis indicated that the UMAE process is both spontaneous and endothermic. Scanning electron microscopy (SEM) images, X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectra of resulted extract under optimal conditions revealed a disrupted structural network, analyzed the nature and identified the primary functional groups, respectively. This research showed that using UMAE with ethanol is a quick, effective, and eco-friendly method for extracting pomegranate peel.

Codesign of transmit waveform and reflective beamforming for active reconfigurable intelligent surface-aided MIMO ISAC system

This article discusses the active reconfigurable intelligent surface (ARIS)-aided integrated sensing and communication (ISAC) system for non-line-of-sight (NLoS) target sensing in cluttered environments while performing multi-user communication. To optimize sensing and communication performance simultaneously, we jointly design the shared transmit waveform, ARIS reflection coefficients and radar receive filter by using the multi-user interference and the reciprocal of radar output signal-to-interference-plus-noise ratio as metrics. Limited by practical requirements, the transmit waveform suffers from constant modulus or total energy constraints and the ARIS is subject to both maximum power and amplification gain constraints. Based on these considerations, the proposed codesign is formulated into a nonconvex constrained fractional function minimization problem. To tackle it effectively, we first translate the fractional objective into an integral form by employing Dinkelbach transform and then propose an alternating optimization-based algorithm, where the transmit waveform and ARIS reflection coefficients are respectively optimized by the customized algorithms based on the consensus alternating direction method of multipliers, and the receive filter has a closed-form optimal solution. Numerical results demonstrate that the ARIS-aided ISAC concurrently achieve superior NLoS sensing and communication performance to passive reconfigurable intelligent surface-aided and traditional ISACs in cluttered environments, regardless of waveform constraints and sensing-communication trade-off factor.

Proposal of a quantum version of active particles via a nonunitary quantum walk.

The main aim of the present paper is to define an active particle in a quantum framework as a minimal model of quantum active matter and investigate the differences and similarities of quantum and classical active matter. Although the field of active matter has been expanding, most research has been conducted on classical systems. Here, we propose a truly deterministic quantum active-particle model with a nonunitary quantum walk as the minimal model of quantum active matter. We aim to reproduce results obtained previously with classical active Brownian particles; that is, a Brownian particle, with finite energy take-up, becomes active and climbs up a potential wall. We realize such a system with nonunitary quantum walks. We introduce new internal states, the ground state and the excited state , and a new nonunitary operator N(g) for an asymmetric transition between and . The non-Hermiticity parameter promotes the transition to the excited state; hence, the particle takes up energy from the environment. For our quantum active particle, we successfully observe that the movement of the quantum walker becomes more active in a nontrivial manner as we increase the non-Hermiticity parameter , which is similar to the classical active Brownian particle. We also observe three unique features of quantum walks, namely, ballistic propagation of peaks in one dimension, the walker staying on the constant energy plane in two dimensions, and oscillations originating from the resonant transition between the ground state and the excited state both in one and two dimensions.

Role of sputtered atom and ion energy distribution in films deposited by physical vapor deposition: A molecular dynamics approach

We present a comparative molecular dynamics simulation study of copper film growth between various physical vapor deposition (PVD) techniques: a constant energy neutral beam, thermal evaporation, dc magnetron sputtering, high-power impulse magnetron sputtering (HiPIMS), and bipolar HiPIMS. Experimentally determined energy distribution functions were utilized to model the deposition processes. Our results indicate significant differences in the film quality, growth rate, and substrate erosion. Bipolar HiPIMS shows the potential for an improved film structure under certain conditions, albeit with increased substrate erosion. Bipolar HiPIMS (+180 V and 10% Cu+ ions) exhibited the best film properties in terms of crystallinity and atomic stress among the PVD processes investigated.

The impact of delay on second-order evolution equations

Abstract This article aims to exhibit new instability results on the effects of arbitrary delay on a class of second-order evolution equations involving in a Hilbert space. More precisely, we prove that arbitrary finite, large or small delay might remarkably destroy the stability of a well-behaved (stable) system, that is by driving the resulting system with delay to generate non-trivial periodic solutions with constant energy, solutions with exponential growth rate and solutions with blow-up energy. Also, an interesting new effect of large delay is constructively established. We further supply this study with applications and numerical simulations.

Effect of Ta content on elastic properties and magnetic properties of Zr-Ta binary alloys via first-principles calculation

Abstract β-type Zirconium alloys are promising biomedical implant materials, the elastic and magnetic properties of which are of great importance to be studied. In this work, β-type Zr1-xTax binary alloys (x=0.0625, 0.125, 0.1875, 0.25, 0.3125, 0.375, 0.4375, 0.50, 0.5625, 0.625, 0.6875, 0.75, 0.8125, 0.875, 0.9375) were established. The effects of Ta content on lattice constant, elastic properties and magnetic properties of β-type Zr-Ta alloys were investigated via first-principles calculations, the calculated results were also verified through experiments. The results shown that with the increase of Ta content, the lattice constant and total energy of β-type Zr-Ta alloys gradually decreased, the elastic moduli of E, K and G increased on the whole, and the magnetic moment generally increased first and then decreased. The changing trend of elastic and magnetic properties were consistent between experimental and calculated results. Notably, Zr0.875Ta0.125 exhibited the lowest Young’s modulus and magnetic susceptibility among the β-type Zr-Ta alloys, which was one-third that of Ti-6Al-4V, meeting the requirements for low Young’s modulus and low magnetism, and can be anticipated to be promising biomedical implant materials.

Spatter detection and tracking in high-speed video observations of laser powder bed fusion

Purpose In laser powder bed fusion (L-PBF) additive manufacturing, spatter particles are ejected from the melt pool and can be detrimental to material performance and powder recycling. Quantifying spatter generation with respect to processing conditions is a step toward mitigating spatter and better understanding the phenomenon. This paper reveals process insights of spatter phenomena by automatically annotating spatter particles in high-speed video observations using machine learning. Design/methodology/approach A high-speed camera was used to observe the L-PBF process while varying laser power, laser scan speed and scan strategy on a constant geometry on an EOSM290 using Ti-6Al-4V powder. Two separate convolutional neural networks were trained to segment and track spatter particles in captured high-speed videos for spatter characterization. Findings Spatter generation and ejection angle significantly differ between keyhole and conduction mode melting. High laser powers lead to large ejections at the beginning of scan lines. Slow and fast build rates produce more spatter than moderate build rates at constant energy density. Scan strategies with more scan vectors lead to more spatter. The presence of powder significantly increases the amount of spatter generated during the process. Originality/value With the ability to automatically annotate a large volume of high-speed video data sets with high accuracy, an experimental design of observed parameter changes reveals quantitively stark changes in spatter morphology that can aid process development to mitigate spatter occurrence and impacts on material performance.

Axion production in the η → ππa decay within SU(3) chiral perturbation theory

We study the axion and axion-like particle production from the η → ππa decay within the SU(3) chiral perturbation theory up to the one-loop level. The conventional SU(3) chiral low energy constants are found to be able to reabsorb all the divergences from the chiral loops in the η → ππa decay amplitude, and hence render the amplitude independent of the renormalization scale. The unitarized η → ππa decay amplitudes are constructed to take into account the ππ final-state interactions and also properly reproduce the perturbative results from the chiral perturbation theory. Detailed analyses between the perturbative amplitudes and the unitarized ones are given in the phenomenological discussions. By taking the values of the chiral low energy constants in literature, we predict the Dalitz distributions, the spectra of the ππ and aπ systems, and also the branching ratios of the η → ππa process by varying ma from 0 to mη − 2mπ.

Synthesis of Gold Nanoparticles by Pulsed Laser Ablation and its Study Physical and Mechanical Properties

In this work, the pulsed laser ablation technique was used, which is considered a good and distinctive method. Gold nanoparticles (AuNP) were prepared using an Nd-YAG laser with specific parameters, wavelength 1064 nm, constant ablation energy 1000 mJ, frequency 1 Hz, and different number of pulses (300, 600, and 900 pulse/sec). Deionized water was used as the medium liquid. The purpose of this study was to examine the change in these parameters on AuNP using a variety of Xrd, FESEM, Uv-Vis, force-hardness, and compression measurements. The pure cubic crystal structure of gold nanoparticles was analyzed using XRD. Subsequent FESEM images (average diameters 78.07nm, 49.15nm, 37.67nm) indicate that the particles had highly spherical and quasi-spherical shapes. Using ultraviolet analysis, the absorption band of gold nanoparticles was found and the wavelength was (518, 519, 524) nanometers, respectively. There were three different power gaps (1.895, 2.005, and 2.084) eV. In addition, mechanical property tests were conducted, where 2 ml of gold nanoparticles were mixed with (3 grams) of traditional dental filling. The hardness value increased by (3%). The results also showed an increase in the stress and strain value and an increase in Young’s modulus. Hence, an increase in the compressive strength. This indicates that AuNP affects the mechanical properties and enhances their effectiveness.