bluuebunny/crossref_metadata_2025 huggingface dataset:
The number of spanning trees in K

n
-chain and ring graphs
Authors: Cheng Sujing , Ge Jun
Published: October 2024

The problem of counting spanning trees of graphs or networks is a fundamental and crucial area of research in combinatorics, while has numerous important applications in statistical physics, network theory and theoretical computer science. Very recently, Kosar, Zaman, Ali and Ullah obtained a nice formula on the number of spanning trees of a K
5-chain network

K

5

ℓ

constructed by connecting ℓcopys of complete graphs K
5. They made extensive use of matrix theory and spectral graph theory, especially the normalized Laplacian of graphs. In this paper, by using a rather simple and more physical treatment (the mesh-star transformation in electrical network) without any linear algebra, we generalize their result to K

n
-chain graphs and K

n
-ring graphs. The results show that there is a simple relation between the number of spanning trees of the K

n
-chain graph

L

n

ℓ

and the K

n
-ring graph

C

n

ℓ

. We also calculate the corresponding tree entropy (or so called ‘the asymptotic growth constant’) and find that the tree entropy of the corresponding K

n
-chain graphs and K

n
-ring graphs are totally the same.
Study of structural, magnetic, and physical properties in nano cobalt ferrite by computational analysis
Authors: Boussaida B , Masrour R , Tamboli Qudsiya Y , Patange Sunil M , Zakde Kranti R
Published: October 2024

Using the DFT+U method, we investigated the structural, magnetic, electronic, mechanical, thermal, optical, thermoelectric, and thermodynamic properties of the CoFe2O4 system. The GGA approximation was employed to calculate the exchange–correlation potential. The CoFe2O4 has a metallic bond and is ductile, as determined by Poisson’s and Pugh’s ratio mathematical calculations. Transport properties such as the figure of merit, thermal (k/τ) and electrical (σ/τ) conductivities, power factor, and Seebeck coefficient were computed to explain the thermal behavior of this spinel. Additionally, optical parameters like energy loss L(ω), absorption coefficient α(ω), dielectric constants ε(ω), optical conductivity σ(ω), reflectivity R(ω), extinction coefficient k(ω), and refractive index n(ω) are investigated. Lastly, we study how the magnetic phase transitions, magnetization, critical temperature, and specific heat capacity of this material are affected by an external magnetic field at constant pressure. Around the critical temperature, magnetic entropy and relative cooling capacity for various external magnetic fields are obtained.
Quantum pairwise-parallel mismatch attack on Kyber
Authors: Wang Yaru , Liu Jianmei
Published: October 2024

Quantum algorithm uses the quantum parallel method to calculate, which can better solve the encryption and decryption problems in cryptography and secure communication. This paper proposeS a quantum pairwise-parallel mismatch attack on Kyber using the quantum binary search method. We first give quantum search methods for finding the secret key and show that our method can be applied to Kyber. Then, According to the proposed quantum search method, we compute the number of queries required and computational complexity for recovering the full key on Kyber. Compared with the existing results, our improved attack significantly reduces the number of queries and computational complexity.
Gas jet target with controllable density via throat diameter of conical nozzle
Authors: Zuo Zebin , Yang Yang , Chen Guanglong , Cao Yunjiu
Published: October 2024

A supersonic gas jet has been a special target in the ultraintense laser interaction field due to its controllable atomic density distribution. This work investigates the spatial atomic density distribution in argon gas jets ejected from conical nozzles with different throat diameters. Both experiment and simulation results show that the atomic density and its distribution can be controlled by changing the throat diameter of the conical nozzle. The quantitative dependence of atomic density on the throat diameter under different backing pressures is obtained. It also agrees with that from the one-dimensional gas dynamics model. However, it is noted that for a large throat diameter at a high gas backing pressure, a radial saddle-shaped atomic density profile is demonstrated experimentally within a few millimeters away from the nozzle outlet. The results are helpful to optimize the density profile in gas-jet targets and to understand the effect of the throat diameter of the conical nozzle on cluster size in Hagena scaling law.
Energy trapping to substitutional and charge compensation defects in persistent luminescent BaAl2O4:Tb3+
Authors: Jayaramu Shivaramu Nagarasanakote , Coetsee Elizabeth , Hölsä Jorma , Swart Hendrik C
Published: October 2024

The holistic approach of the photoluminescence (PL), thermoluminescence (TL), and persistent luminescence properties at room temperature of BaAl2O4:Tb3+ were investigated in detail using a wide range of techniques. Materials were obtained using a solution combustion synthesis. The x-ray powder diffraction patterns of nondoped and Tb3+ doped BaAl2O4 indicated the hexagonal phase, and a Tb4O7 solid solution was observed at 4 and 5 mol% Tb doped aluminate. X-ray photoelectron spectroscopy revealed that Ba occupied one site and that Tb ions occupied this site as Tb3+ as well as TbIV. PL emission in blue, green, and red was observed under an excitation at 228 nm, that originated from the interconfigurational 4f8–4f75d1 transitions of Tb3+. Time-of-flight secondary ion mass spectroscopy, UV–vis diffuse reflectance, and PL revealed the presence of a Cr3+ impurity. The 0.5 mol% Tb3+ doped BaAl2O4 exhibited a strong TL band at 354, 437 and 598 K, which were attributed to the traps formed by Tb3+ doping and subsequent O2− charge compensation. A persistent luminescence mechanism was constructed for the Tb3+ doped BaAl2O4. After the energy was stored in thermally liberated Tb3+ in the Ba2+ substitution sites and charge compensation defects, the Tb3+ was the source of the continuous luminescence.
A chaotic time series prediction model based on the improved dung beetle optimizer and echo state network
Authors: Wang Lei , Lun Shuxian , Li Ming , Lu Xiaodong
Published: October 2024

Echo state network (ESN) possesses advantages such as simple network structure, ease of training, and reliable prediction performance, making them widely applied in the field of time series prediction. Selecting the optimal reservoir parameters is a key issue in ESN research, as it determines the effectiveness of the network prediction, and it is crucial to design an efficient optimization method for parameter optimization. This paper introduces an improved version of the dung beetle optimizer (IDBO), which employs various strategies to enhance population initialization, algorithm optimization capability, and convergence speed. For theoretical function optimization problems, comparing IDBO with other commonly used optimization methods validated its effectiveness and feasibility. Subsequently, combining IDBO with ESN to construct a new model, IDBO-ESN, and conducting time series prediction experiments, the superior performance of this model is verified on two benchmark datasets and one real dataset.
Optimal quantum controls robust against detuning error
Authors: Kukita Shingo , Kiya Haruki , Kondo Yasushi
Published: October 2024

Precise control of quantum systems is one of the most important milestones for achieving practical quantum technologies, such as computation, sensing, and communication. Several factors deteriorate the control precision and thus their suppression is strongly demanded. One of the dominant factors is systematic errors, which are caused by discord between an expected parameter in control and its actual value. Error-robust control sequences, known as composite pulses, have been invented in the field of nuclear magnetic resonance (NMR). These sequences mainly focus on the suppression of errors in one-qubit control. The one-qubit control, which is the most fundamental in a wide range of quantum technologies, often suffers from detuning error. As there are many possible control sequences robust against the detuning error, it will practically be important to find ‘optimal’ robust controls with respect to several cost functions such as time required for operation, and pulse-area during the operation, which corresponds to the energy necessary for control. In this paper, we utilize the Pontryagin’s maximum principle (PMP), a tool for solving optimization problems under inequality constraints, to solve the time and pulse-area optimization problems. We analytically obtain pulse-area optimal controls robust against the detuning error. Moreover, we found that short-CORPSE, which is the shortest known composite pulse so far, is a probable candidate of the time optimal solution according to the PMP. We evaluate the performance of the pulse-area optimal robust control and the short-CORPSE, comparing with that of the direct operation.
Decoherence in electron transport: back-scattering, effect on interference and rectification
Authors: Soori Abhiram , Khanna Udit
Published: October 2024

Decoherence is an undesirable, but ubiquitous phenomenon in quantum systems. Here, we study the effect of partial decoherence, induced via a Büttiker probe, on two-terminal electronic transport across one-dimensional quantum wires and rings, in both the linear and non-linear regimes. We find that dephasing causes backscattering when introduced locally in a ballistic channel. Further, we find that decoherence results in rectification when inversion is broken in the two-terminal transport set-up by a combination of a local dephasing centre and a static impurity. Interestingly, the rectification strength and even its direction varies strongly with the relative distance between the probe and the scatterer. We further analyze how decoherence affects characteristic quantum effects in electronic transport, such as, Fabry-Pérot oscillations in double-barrier setups, and Aharonov–Bohm interference in one-dimensional rings, and find that the amplitude of oscillations in conductance is reduced by decoherence.
Multi-wing chaotic system based on meminductor and its application in image encryption
Authors: Ding Pengfei , Hu Weiwei , Geng Penghui , Yang Le
Published: October 2024

Meminductor is a novel type of nonlinear device following the memristor, characterized by its memory properties. Currently, research on meminductors is still in its infancy, with their physical devices yet to be formally realized. Therefore, conducting fundamental research on their nonlinear circuit properties and applications is of great significance. In this paper, a new multi-wing chaotic system is proposed based on the mathematical model of a magnetically controlled meminductor. By varying the values of its parameters, the system can generate two-wing, three-wing, and four-wing chaotic attractors. Various analytical methods are employed to study the dynamical behaviours of the proposed chaotic system. The results demonstrate that the system is highly sensitive to its initial conditions and control parameters, which makes it suitable for image encryption. Based on the new system, we propose a new algorithm for image encryption that combines the newly established four-dimensional multi-wing chaotic system with bit plane decomposition technique, firstly, the high four-bit planes containing 94% image information are disordered by S-type permutation, then the disordered bit planes perform operation of XOR with the random matrix generated by chaotic sequences, and finally, the encrypted image is obtained by merging the bit planes.
Complexation mechanism and adsorption modes of Cu (II) ions by wool keratin powder
Authors: Li Liang , Zeng Yuan , Ge Beibei , Liu Shuping , Liu Rangtong
Published: October 2024

The excessive presence of Cu (II) ions in wastewater has led to various health problems. Using wool keratin powder adsorbent, the adsorption of Cu (II) ions in wastewater was explored. The adsorption mechanism and efficiency of keratin powder towards Cu (II) ions were characterized by infrared spectroscopy, x-ray diffraction and scanning electron microscopy. The results indicate that the particle size of keratin powder has a significant impact on its adsorption performances. Keratin powder with smaller particle size has more adsorption sites, larger specific surface area, higher porosity and more effective adsorption capacity. After adsorption of Cu (II), the average diameter of keratin powder increased by 11.48 μm. The adsorption capacity reached 58.95 mg g−1, and the adsorption efficiency reached 99.52% after 12 h of contact time. The research results not only provide an effective solution for Cu (II) ion pollution in wastewater, but also explore the resource utilization of waste wool.
Finite element simulations of quartz crystal microbalances (QCM): from Sauerbrey to fractional viscoelasticity under water
Authors: Vélez-Cordero J Rodrigo , Jonguitud Flores Silvia , Yáñez Soto Bernardo
Published: October 2024

2D finite element simulations are performed on QCM working in the thickness-shear mode and loaded with different homogeneous films. They include a purely elastic film, a viscoelastic Maxwellian liquid, viscoelastic-Voigt solid, and the fractional viscoelastic (power-law) version of each case. Unlike single-relaxation kind models, fractional viscoelasticity considers the relaxation-time spectrum often found in polymeric materials. The films are tested in air or covered with liquids of different viscosities. Two substrate thicknesses are tested: 100 nm and 500 nm, the latter being close to the condition that promotes the resonance of the adsorbed film. In all cases the simulations are compared with small-load approximation theory (SLA). The 100 nm films follow the theory closely, although significant deviations of the SLA are observed as the overtone number n increases, even in purely elastic films. We also show that it is possible to identify the viscoelastic ‘fingerprint’ of the 100 nm films in air using raw data and Sauerbrey’s equivalent thickness obtained with the QCM in the 3 < n < 13 range. These numerical data are validated by experimental measurements of crosslinked polydimethylsiloxane films with thicknesses ∼150 nm. In contrast, the 500 nm films deviate notoriously from the SLA, for all viscoelastic models and overtones, with the largest deviation observed in the elastic film. When a liquid layer covers the QCM without an adsorbed film, the only overtone that numerically reproduces the theoretical value is the fundamental, n = 1. For n > 1, strong coupling between the solid and liquid is detected, and the original vibration modes of the crystal are altered by the presence of the liquid. Finally, the numerical simulations suggest that it is possible to detect whether a viscoelastic film is formed under a liquid layer using only the information from n = 1. In these film/liquid systems we also observe the so-called missing-mass effect, although the theory and simulations exhibit different levels of impact of such effect when the liquid viscosity is high.
The Hadamard condition on a Cauchy surface and the renormalized stress-energy tensor
Authors: Juárez-Aubry Benito A. , Kay Bernard S. , Miramontes Tonatiuh , Sudarsky Daniel
Published: October 2024

Given a Cauchy surface in a curved spacetime and a suitably defined quantum state on the CCR algebra of the Klein-Gordon quantum field on that surface, we show, by expanding the squared spacetime geodesic distance and the 'U' and 'V' Hadamard coefficients (and suitable derivatives thereof) in sufficiently accurate covariant Taylor expansions on the surface that the renormalized expectation value of the quantum stress-energy tensor on the surface is determined by the geometry of the surface and the first 4 time derivatives of the metric off the surface, in addition to the Cauchy data for the field's two-point function. This result has been anticipated in and is motivated by a previous investigation by the authors on the initial value problem in semiclassical gravity, for which the geometric initial data corresponds, a priori, to the spatial metric on the surface and up to 3 time derivatives off the surface, but where it was argued that the fourth derivative can be obtained with aid of the field equations on the initial surface.
Impact of the Epoch of Reionization sources on the 21-cm bispectrum
Authors: Noble Leon , Kamran Mohd , Majumdar Suman , Murmu Chandra Shekhar , Ghara Raghunath , Mellema Garrelt , Iliev Ilian T. , Pritchard Jonathan R.
Published: October 2024

The morphology of the 21-cm signal emitted by the neutral hydrogen present in the
intergalactic medium (IGM) during the Epoch of Reionization (EoR) depends both on the properties
of the sources of ionizing radiation and on the underlying physical processes within the
IGM. Variation in the morphology of the IGM 21-cm signal due to the different sources of the EoR
is expected to have a significant impact on the 21-cm bispectrum, which is one of the crucial
observable statistics that can evaluate the non-Gaussianity present in the signal and which can be
estimated from radio interferometric observations of the EoR. Here we present the 21-cm
bispectrum for different reionization scenarios assuming different simulated models for the
sources of reionization. We also demonstrate how well the 21-cm bispectrum can distinguish between
different IGM 21-cm signal morphologies, arising due to the differences in the reionization
scenarios, which will help us shed light on the nature of the sources of ionizing photons. Our
estimated large-scale bispectrum for all unique k-triangle shapes shows a significant difference
in the magnitude and sign across different reionization scenarios. Additionally, our focused
analysis of bispectrum for a few specific k-triangle shapes (e.g. squeezed-limit, linear, and
shapes in the vicinity of the squeezed-limit) shows that the large scale 21-cm bispectrum can
distinguish between reionization scenarios that show inside-out, outside-in and a combination of
inside-out and outside-in morphologies. These results highlight the potential of using the 21-cm
bispectrum for constraining different reionization scenarios.
Gravitational waves from collapse of pressureless matter in the early universe
Authors: Dalianis Ioannis , Kouvaris Chris
Published: October 2024

If an early matter phase of the Universe existed after inflation with the proper power spectrum, enhanced density perturbations can decouple from the Hubble flow, turn around and collapse. In contrast to
what happens in a radiation dominated Universe where pressure nullifies deviations from sphericity in these perturbations, in a matter dominated Universe, the lack of pressure although on the one hand facilitates the gravitational collapse, it allows small deviations from sphericity to grow substantially as the collapse takes place. The subsequent collapse is complicated: initially as non-spherical deviations grow, the collapsing cloud takes the form of a “Zel'dovich pancake”. After that, the more chaotic and nonlinear stage of violent relaxation begins where shells of the cloud cross and the matter is redistributed within a factor of a few of the free fall timescale, reaching a spherical virialized state. During the whole process, strong gravitational waves are emitted due to the anisotropy of the collapse and
the small time interval that the effect takes place. The emission of gravitational waves during the stage of the violent relaxation cannot be easily estimated with an analytical model. We perform an N-body simulation to capture the behaviour of matter during this stage in order to estimate the precise spectrum of gravitational waves produced in this scenario.
Explaining PTA results by metastable cosmic strings from SO(10) GUT
Authors: Antusch Stefan , Hinze Kevin , Saad Shaikh
Published: October 2024

In a recent paper (Phys. Rev. D108 (2023) 095053), we have demonstrated that the 2023 PTA results, which hint at a stochastic gravitational wave (GW) background at nanohertz frequencies, point towards a promising model-building route for realizing SO(10) Grand Unification with embedded inflation. The proposed supersymmetric scenario solves the doublet-triplet splitting without fine-tuning, accounts for charged fermion and neutrino masses, avoids conflicts with current proton decay bounds, and includes only representations no larger than the adjoint. It features multi-step breaking of SO(10) to the Standard Model gauge symmetry, with inflation embedded such that metastable cosmic strings are produced at the end of inflation. This cosmic string network generates a stochastic GW background that can explain the PTA results. In this paper, we provide a detailed analysis of the singled out GUT model class, focusing on how the gauge coupling unification condition affects the scales of multi-step SO(10) breaking and the preferred GW spectra. The lowest breaking scale, linked to inflation, the generation of right-handed neutrino masses for the seesaw mechanism, and metastable cosmic string production, coincides with the range suggested by the PTA results.
Induced gravitational waves: the effect of first order tensor perturbations
Authors: Picard Raphaël , Malik Karim A.
Published: October 2024

Scalar induced gravitational waves contribute to the cosmological gravitational wave background. They can be related to the primordial density power spectrum produced towards the end of inflation and therefore are a convenient new tool to constrain models of inflation. These waves are sourced by terms quadratic in perturbations and hence appear at second order in cosmological perturbation theory. While the focus of research so far was on purely scalar source terms we also study the effect of including first order tensor perturbations as an additional source. This gives rise to two additional source terms: a term quadratic in the tensor perturbations and a cross term involving mixed scalar and tensor perturbations. We present full analytical expressions for the spectral density of these new source terms and discuss their general behaviour. To illustrate the generation mechanism we study two toy models containing a peak on small scales. For these models we show that the scalar-tensor contribution becomes non-negligible compared to the scalar-scalar contribution on smaller scales. We also consider implications for future gravitational wave surveys.
Implications of neutrino species number and summed mass measurements in cosmological observations
Authors: Sasao N. , Yoshimura M. , Tanaka M.
Published: October 2024

We confront measurable neutrino degrees of freedom N
eff 
and summed neutrino mass
in the early universe to particle physics at the energy scale
beyond the standard model (BSM),
in particular including the issue of neutrino mass type distinction.
The Majorana-type of massive neutrino is perfectly acceptable
by Planck observations, while the Dirac-type neutrino
may survive in a restricted class of models that suppresses
extra right-handed contribution to ΔN
eff = N
eff - 3
at a nearly indistinguishable level from the Majorana case.
There is a chance that
supersymmetry energy scale may be identified in
supersymmetric extension of left-right symmetric model
if improved N
eff measurements discover a finite value.
Combined analysis of this quantity with the summed neutrino mass
helps to determine the neutrino mass ordering pattern,
if measurement accuracy of order, 60 – 80 meV, is achieved,
as in CMB-S4.
Modelling study of divertor W leakage for different divertor conditions with Ne seeding in EAST tokamak
Authors: Xu Guoliang , Wang Hui , Ding Rui , Si Hang , Jia Guozhang , Guo Jin , Xie Hai , Yan Rong , Hai Ran , Zhu Dahuan , Chen Junling
Published: October 2024

Sequential SOLPS-ITER and DIVIMP simulations are carried out for tungsten (W) edge transport during neon (Ne) injection in EAST, elucidating the pathway of W impurity leakage from the divertor to the core plasma under different dissipative divertor conditions. Divertor conditions from low-recycling to detachment are generated by modulating the Ne injection rate in the SOLPS simulation. With the drift velocities incorporated in DIVIMP, W transport under the drift effect is investigated. For low-density L-mode plasma conditions with favorable B
t direction, the majority of W source originates from the outer divertor target and leaks upstream through the near-SOL E× B drift reversed region at both inner and outer divertors. The E× B drift is demonstrated to have a significant effect on W leakage and the effect diminishes with the increase of Ne injection rate. Compared to the D2 injection cases, Ne injection helps to achieve a strong dissipative divertor condition at a much lower plasma density, resulting in a higher W leakage ability due to the smaller friction with the background plasma. For Ne injection cases under high-density H-mode conditions, W leaks mostly through the outer divertor region while the inner divertor is fully detached. Compared to the L-mode cases, the shorter power decay lengths in the scrap-off layer (SOL) of the H-mode cases result in smaller parallel E× B drift velocities especially in the middle and far SOL region. With the increase of the Ne injection rate, the decrease of the E× B drift in the middle SOL leads to a wider near-separatrix W leakage path. Therefore, a worse divertor W screening is expected, which is consistent with the previous published experimental observations (Ding et al 2022 Nucl. Mater. Energy
33 101250).
The consequences of tritium mix for simulated ion cyclotron emission spectra from deuterium-tritium plasmas
Authors: Slade-Harajda T.W. , Chapman S.C. , Dendy R.O.
Published: October 2024

Measurements of ion cyclotron emission (ICE) are obtained from most large magnetically confined fusion plasma experiments, and may be used in future to quantify properties of the fusion-born alpha-particle population in deuterium-tritium (DT) plasmas in ITER. ICE is driven by spatially localised, strongly non-Maxwellian, minority energetic ion populations which relax collectively under the magnetoacoustic cyclotron instability. ICE spectral peaks are typically observed at, near, or separated by, integer harmonics of the energetic ion cyclotron frequency. Here, for the first time, we study how simulated ICE spectra from DT plasmas vary with tritium concentration and compare with an observed JET DT ICE spectrum. We incorporate a population of thermal tritons, in addition to thermal deuterons and an energetic minority population of fusion-born alpha-particles, in simulations with the kinetic particle-in-cell code EPOCH. This code has previously been used extensively for interpretation of ICE observations in terms of the self-consistent gyro-resolved collective Maxwell-Lorentz dynamics of tens of millions of simulation particles. Our simulation parameters are relevant to the ICE-generative outer midplane edge region of JET DT plasma 26 148, which included 11% tritium. Quantifying the variation of simulated ICE power spectra with tritium concentration reveals that our simulation with 11% tritium concentration most accurately represents the observed ICE spectrum from this plasma. This outcome is encouraging for the diagnostic application of ICE to fusion plasmas containing two thermal ion species, including future DT plasmas.
Hyaluronic acid modified Cu/Mn-doped metal-organic framework nanocatalyst for chemodynamic therapy
Authors: Guo Xiaohuan , Fang Qi , Leng Nan , Liu Yuan , Cai Bingbing , Zhou Yuzhu , Wen Changchun
Published: October 2024

Chemodynamic therapy (CDT) is a new method for cancer treatment that produces highly toxic reactive oxygen species (ROS) in the tumor microenvironment to induce cancer cell apoptosis or necrosis. However, the therapeutic effect of CDT is often hindered by intracellular H2O2 deficiency and the activity of antioxidants such as glutathione (GSH). In this study, a nano-catalyst HCM was developed using a self-assembled Cu/Mn-doped metal-organic framework, and its surface was modified with hyaluronic acid to construct a tumor-targeting CDT therapeutic agent with improved the efficiency and specificity. Three substances HHTP (2, 3, 6, 7, 10, 11-hexahydroxybenzophenanthrene), Cu2+, and Mn2+ were shown to be decomposed and released under weakly acidic conditions in tumor cells. HHTP produces exogenous H2O2 in the presence of oxygen to increase the H2O2 content in tumors, Cu2+ reduces GSH content and generates Cu+ in the tumor, and Cu+ and Mn2+ catalyze H2O2 to produce ∙OH in a Fenton-like reaction. Together, these three factors change the tumor microenvironment and improve the efficiency of ROS production. HCM showed selective and efficient cytotoxicity to cancer cells, and could effectively inhibit tumor growth in vivo, indicating a good CDT effect.
Experimental overview of nanoferrites: synthesis, characterization and performance evaluation in wastewater treatment
Authors: Akram Aasma , Altaf Muhammad , Yousaf T , Hussain A A , Alsultany F H , Ishaq M , Saadi B M , Saleh Dalia I
Published: October 2024

This study investigates the potential of ferrite nanoparticles (BaFe12O19, MnFe2O4, NiFe2O4, and Co1–0.5Ni0.5Fe2O4) as eco-friendly adsorbents for the removal of heavy metals (Zn2+, Ni2+, Co2+, and Mn2+) from wastewater. Moreover, the adsorption experiments were conducted under varying contact times (30 min, 1 h, 2 h, and 4 h) and pH levels (2, 7, and 12) for five cycles to evaluate their significant dynamic effects on the removal efficiency. All ferrite nanoparticles were synthesized by the co-precipitation method and characterized (XRD, FT-IR, and SEM) to ascertain their crystal structure, morphology, size distribution, and crystallographic structures before wastewater treatments. The results demonstrated that BaFe12O19 had a particle size of 8.65 nm and achieved maximum adsorption ability of 93%, 91%, 94%, and 91% for Zn2+, Ni2+, Co2+, and Mn2+, respectively, at a pH of 7 after 4 h of treatment. Since the neutral pH value affects the binding of heavy metal ions, therefore governing the adsorption efficiency and selectivity. In contrast, NiFe2O4 (1.41 nm) revealed maximum removal of Zn2+, Ni2+, Co2+, and Mn2+ were 78%, 71%, 88%, and 83%, respectively, at a pH of 12 after 4 h. This was attributed to the negatively charged surface leading to stronger electrostatic attractions between the positively charged metal ions and the adsorbent surface, resulting in higher adsorption uptake. Notably, the higher removal rate of ions was observed during initially 1 h, suggesting a decline in efficiency rate with extended treatment time. Additionally, the experimental study over five cycles concluded that the adsorbent could be effectively regenerated and reused.
Sensitivity and energy resolution of the Balqarad clover detector
Authors: Ababneh E , Alzoubi H , Qbelat A S , Al-Bashaish S R
Published: October 2024

This study investigates operational modes and veto techniques using the Balqarad clover system, focusing on energy resolution parameters like Full Width at Half Maximum (FWHM) and Full Width at Tenth Maximum (FWTM). Comparing with the GAMMA-X detector, clover consistently shows lower FWHM values (e.g., 1.08 keV versus 1.45 keV for133Ba), highlighting its higher precision. The clover system also achieves lower Minimum Detectable Activity (MDA) values (ranging from 1.19 to 1.56 Bq for60Co and137Cs in direct and addback modes), underscoring its enhanced performance compared to literature data. Practical MDA calculations using a reference soil sample reinforce the advantage of addback mode over direct mode in achieving more accurate measurements. These findings stress the critical importance of selecting the right measurement system for precise applications like radiation monitoring and nuclear safety assessments.
How animal metaphors increase tourists’ waste classification intention?
Authors: Sun Dajun , Yang Dajun , Wang Jian , Tan Fuqiang
Published: October 2024

Previous researches have shown that animal metaphors play an important role in promoting specific behavioral dispositions of individuals. However, we are not well aware of the role of animal metaphors in tourists’ waste classification intentions. Therefore, this study aimed to investigate the impact of animal metaphors advertising for waste classification in scenic spots (versus non-animal metaphors advertising) on tourists’ waste classification intentions. Four experiments (N = 1051) were conducted in this study to examine the impacts of animal metaphors advertising in scenic spots, on tourists’ waste classification intentions, which enriches the literature on the animal metaphors and tourists’ pro-environmental behaviors. The results show that the animal metaphors advertising about waste classification in scenic spots can effectively increase tourists’ waste classification intentions. We explored the mediating role of tourists’ perceptions of cute animal images in animal metaphors advertising, and the moderating role of visual imagery for animal metaphors advertising, on the relationship between animal metaphors advertising and tourists’ waste classification intentions. The results show that there is a significant interaction effect between visual imagery and animal metaphors advertising. In conclusion, this study reveals the different impacts of animal metaphors, cute images and visual imagery on individual tourists, which provides new insights for scenic spot managers to choose waste classification strategies and the looks of bins.
Source apportionment of airborne volatile organic compounds near unconventional oil and gas development
Authors: Lachenmayer Emily , Ku I-Ting , Hecobian Arsineh , Benedict Katherine B , Zhou Yong , Buck Brent , Collett Jeffrey L
Published: October 2024

Oil and natural gas (ONG) extraction emits volatile organic compounds (VOCs). Certain VOCs are identified as hazardous air pollutants (HAPS) while others contribute to ozone formation. This study examines the impact of ONG operations on VOC levels during the development of multi-well ONG pads in suburban Broomfield, Colorado. From October 2018 to December 2020, weekly VOC measurements were taken at 18 sites across the area. These included spots near well pads, in adjacent neighborhoods, and at a background site, covering various stages of well pad development including drilling, hydraulic fracturing, flowback, and production. Analysis using Positive Matrix Factorization (PMF) identified six factors, including combustion, background/biogenic sources, light and complex alkanes, drilling activities, and ONG acetylene. Factors linked to local ONG activities exhibited clear temporal and spatial correlations with Broomfield well development. Benzene source analysis revealed distinct contribution gradients, with ONG-related sources notably influencing areas near the well pads, particularly in pre-production. ONG-related weekly benzene contributions varied from 9% to 63% at a community background site and 18% to 89% in a neighborhood close to a well pad.
On the definition of the marginal ice zone: a case study with SAR and passive microwave data
Authors: Soleymani Armina , Patel Muhammed , Xu Linlin , Scott K. Andrea
Published: October 2024

Widening and increasing extent of the marginal ice zone (MIZ), a transitional area between the open ocean and the pack ice, underscores the scientific significance of observing the MIZ. In the present study, we employed passive microwave (PM) and synthetic aperture radar (SAR) sea ice concentration (SIC) in the Greenland Sea and Beaufort Sea in November 2021 to detect the MIZ using two different MIZ definitions: SIC threshold-based (MIZ
t
) and SIC anomaly-based (MIZ
σ
). This study is the first to compare the SIC threshold-based with SIC anomaly-based MIZ definition using two different sources of SIC data. Our findings reveal that the SIC anomaly-based definition delineates a spatially extensive MIZ, capturing SIC variation attributed to sea ice growth. We also found that SAR data, compared to PM data, consistently identifies a broader MIZ region and is less sensitive to the threshold for the SIC anomaly standard deviation, underscoring the importance of selecting the appropriate MIZ definition.
A seat at the energy table
Authors: Brown Kristen E , Sharma Bonita
Published: October 2024

Energy injustice persists due to the difficulty of meeting competing interests in a rapidly evolving system. Transformative energy technologies need to fit into existing structures while also improving upon those systems. To aid in complex decisions, this paper provides a simple checklist of four necessary and often missed concepts for energy justice. Energy choices should be Supported, Environmental, Affordable, and Tolerable to provide everyone a SEAT at the energy table, in other words to promote energy justice. For the purposes of this framework, supported indicates that supply chains and infrastructure to meaningfully participate are available, environmental considerations cover climate change and health-affecting pollutants as well as disposal affecting soil and water, affordability rather straight-forwardly requires equal economic access to the energy transition, and tolerable requires personal and political buy-in. This structure is intended to aid anyone that makes decisions, i.e. not only highly specialized academics. Many technologies that address one or two of these concepts are touted as solutions to injustice, but without additional structure, they may have disbenefits in other areas. By using a simple structure to illuminate this consistent difficulty, future research and policy will be better able to promote true justice instead of tangentially addressing it in ways that fail to capture the complexities of the system. The tension between benefits and unintended consequences is explored for several energy technologies at varying stages of implementation, including electric vehicles, cooking, time-of-use pricing, and air conditioning. Existing policy mechanisms that have tried to address only some barriers have not necessarily resulted in an equitable transition. This indicates that equity needs to be considered explicitly, and that all four chair legs need to be evaluated. This method highlights the principles most easily considered in non-specialist decisions and maps them to concepts that are easy to grasp.
Optimizing process parameters and materials for the conversion of plastic waste into hydrogen
Authors: Hossain Sakib Tanvir , Mahmud M A Parvez
Published: October 2024

This study has investigated hydrogen production from waste plastics using pyrolysis, steam methane reforming, and water-gas-shift reactions modelled via Aspen Plus. After evaluating multiple alternatives, polypropylene (PP) was selected as the feedstock. The research has been focused on how reformer temperature, steam-to-fuel ratio (S/F), reformer pressure, and pyrolysis temperature impact syngas composition, heating values, syngas (H2/CO) ratios, and yields of hydrogen (H2), methane (CH4), and carbon dioxide (CO2). Key findings have indicated that raising reformer temperatures to around 1000°C maximizes hydrogen production in syngas, reaching peak levels of 2360 Nm3/Ton and 2525 Nm3/Ton for reformer temperature and steam-to-fuel ratio (S/F) ratios, respectively, via processes like steam methane reforming and the water-gas-shift reaction. Moreover, other parameters like steam-to-fuel (S/F) ratio and reformer pressure have produced the highest amount of hydrogen at 0.25 and 1 atm, respectively. Optimizing reformer temperature and steam-to-fuel ratio (S/F) have been selected as key in hydrogen production, with peak lower heating values (LHV) of 1.15 MJ/kg for temperature and 1.035 MJ/kg for S/F ratios, highlighting the importance of balancing these parameters for efficiency. Additionally, syngas' hydrogen (H2) composition increased with pyrolysis temperature, peaking at 8.5% at 700°C. Finally, this research has provided valuable insights into optimizing process parameters for sustainable hydrogen production. Moreover, the simulation process has provided cost-effective adjustments and informed decision-making for sustainable and scalable technologies, benefiting researchers, investors, engineers, and policymakers involved in innovative hydrogen generation.
Cyclic shift short-distance attention for defect detection of fine etching mesh
Authors: Zou Yuehao , Long Shengrong , Li Zhinong , Chen Faqiang
Published: October 2024

Based on the deficiency of the existing Swin Transformer in the detection of surface defects in metal etched grids, i.e. the isolation of information transmission between different windows, and the limitations of image matrix size and network structure,which make it not suitable for long sequence data processing and dense prediction scenarios, a defect detection method for metal etching nets based on Cyclic shift Long Short Distance Attention (C-LSDA) is proposed. In the proposed method, cross-scale features are used to capture long and short distance relationships,and enhance the feature transfer between windows. Tracking position bias (TPB) is also used to improve relative position bias (RPB), in order to help the model to better understand the spatial relationships in the input data. In addition, the image is downsampled at various scales, so that the proposed method can be suitable for long sequence data processing and dense prediction scenarios. In order to improve the detection accuracy of small targets. a multi-feature fusion pyramid network (MFFPN) for feature fusion is also proposed. The experimental results show that the proposed method is significantly superior to the traditional CNN recognition method and the transformer recognition method. The proposed methodhas good identification accuracy and low computational cost.
A grey relational analysis of the micro arc oxidation process parameters and their effects on Ti-6Al-7Nb coating performance and corrosion resistance for biomedical uses
Authors: Pesode Pralhad , Barve Shivprakash
Published: October 2024

In current investigation micro arc oxidation of Ti6Al7Nb alloy was done to improve its surface properties and corrosion resistance. Mixture of Na2SiO3, Na3PO412H2O and KOH is used as electrolyte. MAO treated Ti6Al7Nb specimens were examined using x-ray diffraction (XRD), energy dispersive spectroscopy (EDS) and scanning electron microscopy (SEM) to examine their morphology and phase composition. It was observed that electrolyte composition is simultaneously included in the growing oxide layer during MAO process. From electrochemical study it was found that corrosion resistance of the Ti6Al7Nb increases during EIS testing in 0.9% NaCl solution. It was found that frequency, duty cycle, current and processing time effect the surface roughness, thickness, hardness and corrosion resistance of coating. Out of above mention parameters frequency and duty cycle has major impact on performance parameters. The objective of current investigation is to find out effects MAO process parameters on coating performance parameters such as coating thickness, hardness, surface roughness and corrosion resistance. At duty cycle of 50%, frequency 500 Hz, current 300 mA and processing duration 7.5 min, highest coating thickness 32.96 μm and surface roughness 3.3680 μm was obtained. Process parameters have the influence on pore size, biggest average pore size 3.8519 μm was obtained at duty cycle of 50%, frequency 500 Hz, current 300 mA and processing duration 7.5 min. Grey relational analysis is done to determine which process variable has the most influence on performance parameters. From grey relational analysis technique, it was observed that duty cycle 50%, frequency 500 Hz, current 300 mA, and processing time 7.5 min are ideal process parameters for higher coating thickness, hardness, surface roughness and better corrosion resistance. From grey relation analysis it was also found that frequency has most significant impact on performance parameters after that duty cycle, then current and at last processing time.
Numerical simulation of the vibration response of the permafrost subgrade under harmonic irregularity in the Qinghai-Tibet Railway
Authors: Tang Chen-Xuan , Zhu Zhan-Yuan , Ma Yong , Zheng Si-Cheng , Yao Zhi , Xie Guang-Ci , Yang Wen-Zha , Xu Jiao
Published: October 2024

Harmonic excitation can significantly increase the dynamic response of wheel-rail interactions when a train passes. In this study, based on the train-track vertical coupled dynamics model (ZL-TNTLM) and ABAQUS, a unified train-track-subgrade coupled dynamics model is established. Field measurement data corroborated its accuracy and reliability. The analysis focused on the dynamic response of the permafrost subgrade of the Qinghai-Tibet Railway (QTR) to harmonic excitation, including the track-sleeper force and vertical dynamic stress. This study examined the influences of the wavelength, wave depth, and railhead depression on the dynamic response of a subgrade. The results indicated that single-harmonic excitation amplifies the track-sleeper forces and the vertical dynamic stress in the subgrade, particularly near the harmonic centre. Additionally, axle load variations and seasonal thawing broaden the dynamic stress range on the subgrade, with harmonic excitation exacerbating this impact, thereby increasing the risk to the stability of the ice-rich permafrost layer. A decrease in wavelength and increase in wave depth result in a greater number of affected sleepers, intensifying the vertical vibrations of the subgrade, especially in the medium- and high-frequency ranges of vertical dynamic stress. Notably, wavelengths between 1 and 2 m significantly exacerbate the adverse effects on the ice-rich permafrost layer. Shorter wavelengths also induce higher-frequency vibrations. These findings offer valuable insights for the design, operation, and maintenance of permafrost subgrade systems under irregular excitation.
A comprehensive review of wire arc additive manufacturing for metallic functionally graded materials
Authors: Dhanola Anil , Prasad Daya Shankar
Published: October 2024

Functionally graded materials are multifunctional materials, which consist of a spatial modification in composition and microstructure for the definite purpose of controlling variations in various functional properties like mechanical, thermal, and structural. They have been widely utilized in aerospace, healthcare, automobile, and various other industrial applications. Emerging additive manufacturing techniques such as wire arc additive manufacturing are capable of manufacturing complex shapes with gradual variations in composition, microstructure, and customized multifunctional material properties in an additive manner. Metal-based functionally graded materials have been extensively explored in recent times to achieve excellent properties, such as excellent strength and plasticity, good thermal stability, and notable anti-oxidation and anti-wear properties and thus additive manufacturing has proven one of the most necessary techniques to fabricate metal functionally graded materials. This paper intends to offer an in-depth survey of the current leading developments in wire arc additive manufacturing for metallic functionally graded materials and line up researchers, engineers, and industry professionals with an extensive understanding of the potentials, challenges, and opportunities related to wire arc additive manufacturing for functionally graded materials. Additionally, it explores the process parameters for optimizing and analysing various mechanical properties, microstructure, and corrosion behaviour of metal-based functionally graded materials. Early research into the potential of using wire arc additive manufacturing to create various alloys and metal combinations in diverse geometries showcases the many advantages of this emerging manufacturing technology, though further research is needed to justify its commercial application. Therefore, future research directions are proposed based on current findings and the challenges came across.