The European Physical Journal Plus最新文献

Naturally occurring radioactive gases like radon and thoron in soil are well known to impact air quality, influencing the resident’s health in that area. This work measured radon and thoron concentrations in soil and the associated radiation hazard indices using CR-39 detector in Kadhimya, Baghdad, Iraq. The mean radon and thoron concentrations in the area under study were determined to be 295.06 ± 4.00 and 1557.2 ± 29.23 Bq/m³, respectively. The average indoor and outdoor annual effective dose, the excess lifetime cancer risk, and lung cancer cases per year per million people due to radon were found to be 7.44 ± 0.10 mSv/y(,) 1.86 ± 0.03 mSv/y, 3.58 ± 0.05, and (167.49 ± 2.27()times {10}^{-6}), respectively, and due to thoron, they were found to be 39.29 ± 0.74 mSv/y, 9.82 ± 0.18 mSv/y, 18.91 ± 0.35, and (883.94 ± 16.59()times {10}^{-6}), respectively. The average annual effective dose to lungs due to exposure to radon was estimated to be 148.88 ± 2.02 mSv/y. The average effective dose in tracheobronchial and pulmonary + pulmonary lymph region, and the effective dose in lungs were found to be 8.93 ± 0.12 mSv/y, 8.93 ± 0.12 mSv/y, and 17.87 ± 0.24 mSv/y, respectively. The total effective equivalent dose caused by radon, thoron, and their progeny tissues ranged from 5.62 to 49.45, with an average value of 15.60 mSv/year. All the evaluated radiation hazard indices exceeded the recommended limits of radiation protection agencies. Radon and its progeny contribute about (44%) to the total annual inhalation dose, whereas thoron and its progeny contribute about (56%) to the total annual inhalation dose. The surpassing of recommended radiation hazard limits for radon and thoron highlights the need for regulatory actions and public health interventions.

This article presents an innovative study that experimentally investigates the role of amylopectin, extracted from kernels, on the mechanical, physical, and durability properties of natural hydraulic lime (NHL) mortars. Polysaccharides of amylopectin play a major role in increasing the workability of the additive-modified mortar. The amylopectin-modified mortar enhances its compressive strength by 1.68 times compared to the reference mortar. The amylopectin-modified mortar improves its mechanical properties without compromising water absorption and porosity, thus preserving the breathability of the restoration mortar. Amylopectin enhances the hydrophobic property of NHL mortar, forming an outer layer that is resistant to water and salt deposition. The modified mortar’s moisture-holding capacity improves carbonation and reduces drying shrinkage. The polysaccharides of amylopectin enhance the carbonation, regulate the growth of calcite crystals, and result in a denser microstructure, leading to enhanced strength gain. We have also studied the microstructure and morphology characteristics of the modified mortar using XRD, FT-IR, and SEM. We can further extend the investigation to examine the crack capacity of this amylopectin-modified NHL mortar.

Polymer composites are an interesting project for optical devices and medical applications. The influence of modified graphene oxide (GO) nanosheets with nano-chitosan (NCS) nanomaterials on two vinyl polymers was investigated. Polyvinyl pyrrolidone (PVP), polyvinyl alcohol (PVA), and polyacrylic acid (PAA) reinforced with nanomaterials to fabricated PVA-PAA/GO@NCS and PVP-PAA/GO@NCS composites. Strong interfacial interaction exhibited by Fourier-transform infrared spectroscopy. X-ray diffraction showed a semi-crystalline structure. A fine dispersion of nanomaterials was exhibited by image scanning electron microscopy. Optical and transmission electron microscopy revealed the PVA composite’s core–shell formulation, whereas the PVA composite and shrimp shell behavior of PVP composites. The dielectric constant results reduced from 18 to 10.36 for PVA composites and 10.4 to 9.3 for PVP composites. For the dielectric loss, the results enhanced from 15.50 to 1.79 and 2 to 1.4, respectively. The real and imaginary optical dielectric constants improved significantly compared with blended polymers, and composites with PVP presented better results than composites with PVA. In the PVA, the electrical conductivity of composites was enhanced compared to that of the PVP group. Interestingly, PVA nanocomposites revealed a better cytotoxic impact of up to 80% instead of 56% of PVP composites of anti-breast cancer (MTTassa). These interesting findings presented interesting materials for optoelectronic and biological applications.

Graphic abstract

Over the past few decades, there has been an increasing trend toward researching novel photocatalysts for water splitting and protecting the environment from pollution using sunlight. One approach promising for converting solar energy into sustainable hydrogen fuel is solar water splitting using silicon carbide photocatalyst. SiC nanostructures have garnered much attention from researchers due to their unique chemical and physical characteristics for solar-water-splitting applications. Water splitting with the use of solar energy is a clean, environmentally beneficial method that can help overcome the energy issue and make a big contribution to environmental preservation. The development, difficulties, and prospects of employing SiC for water-splitting-based hydrogen production are covered and summarized in this paper. Moreover, self-oxidation, photocorrosion, and electron–hole recombination have all been used to analyze SiC’s photocatalytic performance.

Graphical abstract

This paper presents an algorithm, called the double exponential smoothing slime mould algorithm (DeSSMA), which is formulated to train deep learning models for the precise detection of diseases in patients. The DeSSMA is designed by integrating the principles of double exponential smoothing with the slime mould algorithm. The parameters, including energy depletion, link lifetime (LLT), and distance, are considered by the proposed DeSSMA as objectives aimed at optimizing data routing efficiency. In the base station, a deep residual network (DRN) is trained using the proposed DeSSMA algorithm, which is utilized for disease detection following the processes of data preprocessing, augmentation, and feature selection. Finally, performance evaluation of the DeSSMA-DRN framework is conducted using metrics such as energy consumption, LLT, accuracy, sensitivity, specificity, and receiver operating characteristic. The findings reveal that the proposed framework achieved a minimal energy depletion rate of 0.412 (J), an LLT rate of 0.318, an increased accuracy rate of 0.959, a high sensitivity rate of 0.967, and a specificity rate of 0.931.

In this work, it is shown that electrostatic solitons in a plasma with turbulent heating of the electrons through an accelerating electric field can form with very high velocities, reaching up to several order of magnitudes larger than the equilibrium ion-sound speed. The possible parameter regime, where this work may be relevant, can be found in the so-called dead zones of a protoplanetary disk. Though these zones are stable to magnetorotational instability, the resultant turbulence can in fact heat the electrons making them follow a highly non-Maxwellian velocity distribution. We show that these fast-moving solitons can reach very high velocities. With electron velocity distribution described by the Davydov distribution function, we argue that these solitons can be an effective mechanism for energy equilibration in such a situation through soliton decay and radiation.

The resistive switching behaviour and nonvolatile memory effects in zirconium oxide (ZrO₂) and silver nanoparticles (AgNP)-ZrO₂ nanocomposite films have been studied. To explore the role of adding AgNP in resistive switching of the nanocomposite films, fluorine-doped tin oxide (FTO)/AgNP-ZrO₂/silver (Ag) trilayer structure has been fabricated by spray coating of AgNPs-ZrO₂ on FTO with varying AgNP content in the nanocomposite film. X-ray diffraction (XRD) analysis confirms the single-phase ZrO₂ structure, with no additional peaks corresponding to AgNP due to its low concentration. Current (I)–voltage (V) measurement shows a decrease in switching voltage from 1.8 V for the pure ZrO₂ to 0.38 V for 1 wt% AgNP-ZrO₂ nanocomposite film. The cyclic I-V measurement shows an increase in the on–off ratio from 22 for pure ZrO₂ to 32 for 1 wt% AgNP-ZrO₂ nanocomposite devices. The retentivity measurement shows distinct on–off values for pure ZrO₂ and AgNP-ZrO₂ nanocomposite films over time. The temperature-dependent resistivity (R-T) measurements reveal that all devices (pure ZrO₂, 0.5 wt% AgNP-ZrO₂, and 1 wt% AgNP-ZrO₂) exhibit semiconducting behaviour in the high-resistance state, with activation energy decreasing from 87.1 to 48.43 meV as AgNP content increases. In the low-resistance state, all devices show metallic-like conduction. Additionally, the temperature coefficient of resistance (α) increases from 3.54 × 10^–3 K⁻¹ to 5.15 × 10^–2 K⁻¹ with higher AgNP concentration. The value of α is increased for AgNP-ZrO₂ nanocomposite compared to the ZrO₂ device, suggesting that in pure ZrO₂, only oxygen vacancies were involved, whereas, in AgNP-ZrO₂ nanocomposite, both oxygen vacancies and Ag metal nanoparticles participate in the formation of conducting filaments.

Graphical abstract

The two-Higgs-doublet model augmented with a complex scalar singlet (2HDMS) is a well-motivated candidate for Beyond Standard Model (BSM) Physics. We investigate the dark matter phenomenology of the 2HDMS with the complex scalar singlet as the dark matter candidate. We perform a study of the parameter space allowed by existing theoretical and experimental constraints from dark matter, flavour physics and collider searches. Further, we discuss a few benchmark scenarios to test the discovery potential for the 2HDMS at the HL-LHC and at future high-energy (e^+e^-) colliders.

This work carefully examines the variations in chitosan films derived from shrimp and crab shells in terms of their optical characteristics and laser-induced photoluminescence. Chitosan was dissolved in acetic acid and then cast into films to create chitosan films. The functional properties of chitosan generated from crab and prawns were shown to differ in specific spectrum regions due to differences in hydrogen bonding, degree of deacetylation, and structural conformations, as indicated by the FTIR study. Using TD-DFT and TD-DFT/CASTEP simulations, computational studies were carried out to predict the chitosan samples' molecular structures and frequency characteristics. Measurements and analyses were done on the optical characteristics, such as absorbance, refractive index, dielectric constants, and optical conductivity. Chitosan from shrimp shells (chitosan 2) and crab shells (chitosan 1) differed significantly in terms of UV absorbance, refractive index, dielectric constant, and optical conductivity, according to the study. Chitosan 2 showed increased dielectric constant, refractive index, and UV absorbance, indicating higher optical conductivity and a larger capacity for electrical energy storage, making it a better fit for optoelectronic applications. Chitosan's optical and photoluminescence characteristics are greatly influenced by its place of origin. These results emphasize how crucial it is to choose the right source material for a given optical application, especially in domains, where precise control over UV absorption and refractive index is necessary.

In this article, we will explore the collective impact of Starobinsky model and horizon function in the proximity of f(R) the theory of gravity (R is the Ricci scalar) in the dissipative gravitational collapse. Our investigation delves into the radiating stellar model with string density accompanied by an exterior Vaidya spacetime in f(R) gravity. We precisely explain the boundary conditions and non-vanishing radial pressure due to heat flux in the presented model. In the model presented here, we have used the horizon function with Starobinsky and Krori and Barua assumptions in the presence of strings to demonstrate the end states of black hole collapse. Graphical analysis is also presented to strengthen our arguments.