bluuebunny/crossref_metadata_2025 huggingface dataset:
Small basis set density functional theory method for cost-efficient, large-scale condensed matter simulations
Authors: Keller Elisabeth , Morgenstein Jack , Reuter Karsten , Margraf Johannes T.
Published: August 2024

We present an efficient first-principles based method geared toward reliably predicting the structures of solid materials across the Periodic Table. To this end, we use a density functional theory baseline with a compact, near-minimal min+s basis set, yielding low computational costs and memory demands. Since the use of such a small basis set leads to systematic errors in chemical bond lengths, we develop a linear pairwise correction, available for elements Z = 1–86 (excluding the lanthanide series), parameterized for use with the Perdew–Burke–Ernzerhof exchange–correlation functional. We demonstrate the reliability of this corrected approach for equilibrium volumes across the Periodic Table and the transferability to differently coordinated environments and multi-elemental crystals. We examine relative energies, forces, and stresses in geometry optimizations and molecular dynamics simulations.
Non-adiabatic dynamics studies of the C+(2P1/2, 3/2) + H2 reaction: Based on global diabatic potential energy surfaces of CH2+
Authors: Li Wentao , Dong Bin , Niu Xianghong , Wang Meishan , Zhang Yong
Published: August 2024

Global diabatic potential energy surfaces (PESs) of CH2+ are constructed using the neural network method with a specific function based on 18 213 ab initio points. The multi-reference configuration interaction method with the aug-cc-pVQZ basis set is adopted to perform the ab initio calculations. The topographical properties of the diabatic PESs are examined in detail. In general, the diabatic PESs provide an accurate quasi-diabatic representation. To validate the diabatic PESs, the dynamics studies of the C+(2P1/2, 3/2) + H2 (v0 = 0, j0 = 0) → H + CH+(X1Σ+) reaction are performed using the time-dependent wave packet method. The reaction probabilities, integral cross sections, differential cross sections, and rate constants are calculated and compared with the experimental and theoretical results. Non-adiabatic dynamics results are in good agreement with experimental data. In addition, the non-adiabatic effect in the C+(2P1/2, 3/2) + H2 reaction is significant due to the non-adiabatic results being obviously larger than adiabatic values. The reasonable non-adiabatic dynamics results indicate that present diabatic PESs can be recommended for any type of dynamics study.
Quantum state engineering in a five-state chainwise system by generalized coincident pulse technique
Authors: Zhang Jiahui
Published: August 2024

In this paper, an exact analytical solution is presented for achieving coherent population transfer and creating arbitrary coherent superposition states in a five-state chainwise system by a train of coincident pulses. We show that the solution of a five-state chainwise system can be reduced to an equivalent three-state Λ-type one with the simplest resonant coupling under the assumption of adiabatic elimination together with a requirement of the relation among the four coincident pulses. In this method, the four coincident pulses at each step all have the same time dependence, but with specific magnitudes. The results show that, by using a train of appropriately coincident pulses, this technique not only enables complete population transfer, but also creates any desired coherent superposition between the initial and final states, while the population in all intermediate states is effectively suppressed. Furthermore, this technique can also exhibit a one-way population transfer behavior. The results are of potential interest in applications where high-fidelity multi-state quantum control is essential, e.g., quantum information, atom optics, formation of ultracold molecules, cavity QED, nuclear coherent population transfer, and light transfer in waveguide arrays.
Structural diversity in condensed matter: A general characterization of crystals, amorphous solids, and the structures between
Authors: Wang Yueran , Harrowell Peter
Published: August 2024

A definition of structural diversity, adapted from the biodiversity literature, is introduced to provide a general characterization of structures of condensed matter. Using the favored local structure lattice model as a testbed, the diversity measure is found to effectively filter extrinsic noise and provide a useful differentiation between crystal and amorphous structures. We identify an interesting class of structures intermediate between crystals and glasses that are characterized by a complex combination of short-range ordering and long-range disorder. We demonstrate how the diversity can be used as an order parameter to organize various scenarios by structure change in response to increasing diversity.
Improving equations of state calibrations in the toroidal DAC—The case study of molybdenum
Authors: Zurkowski C. C. , Lim R. E. , Pardo O. S. , O’ Bannon E. F. , Glazyrin K. , Söderlind P. , Jenei Zs.
Published: August 2024

We report an updated isothermal equation of state (EoS) of molybdenum (Mo) obtained by compression in beveled and toroidal diamond-anvil cells (DACs). For an improved compression environment, we developed a copper (Cu) pressure-transmitting medium (PTM) for the toroidal diamond-anvil cell samples, as it is a soft metal compared to Mo with a well calibrated EoS. A Ne PTM was used for the conventional beveled DAC samples. The unit-cell volumes of Mo were measured to 336(1) GPa in the Cu PTM and 231.2(6) GPa in the Ne PTM at room temperature. We additionally calculated elastic stiffness and compliance constants and evaluated the uniaxial stress of Mo and Cu with pressure. A new EoS for Mo is presented from data collected in all sample environments and compared to our theoretical predictions as well as previous compression studies of Mo. The (200) lattice plane of Mo produced the lowest volumes across the pressure range of this study for all compression environments, suggesting that it is less affected by nonhydrostatic stresses in the DAC compared to the other observed diffraction planes. The presented Mo EoS is compatible with extrapolations of EoS fits of Mo in helium (He) within ∼1% at 330 GPa. Results from this work demonstrate that compressing a sample in a softer metal in the toroidal DAC can improve the compression environment and result in measured sample volumes comparable to those collected in noble-gas media at multi-megabar conditions.
Improving dementia and palliative care through the co-design of an integrated model of care
Authors: Triandafilidis Zoi , Goodwin Nicholas , Hutchinson Karen , Jeong Sarah Yeun-Sim , Lewis Suzanne , Hodyl Nicolette , Quick Georgie , Hensby Jacinta , Montague Andrew
Published: August 2024

A need exists to improve end-of-life care for people with advanced dementia, by integrating available services. Stakeholders on the Central Coast of New South Wales united to co-design an improved model of care that would integrate care across care settings. The aim of this project was to co-design a model of integrated, person-centred palliative care for people with dementia at the end of life. This case study describes seven co-design workshops which took place in 2023 to develop a program logic model. Workshops were run in a hybrid format, with stakeholders attending in person and online. Workshops were attended by an average of 26 stakeholders including people and carers with lived experience of dementia, healthcare workers from hospital and community-based services (public and private), primary care clinicians, and participants from the not-for-profit sector and academia. Stakeholders developed a shared mission and purpose and identified priority areas for improving palliative care for people with advanced dementia. This led to the development of a program logic model, which included components relating to education for people with dementia, carers, and professionals, care coordination and referrals, and regular multidisciplinary case conferences. Feedback on the model from a new audience identified areas for improvement. The stakeholder group participated in a survey to evaluate the effectiveness of the co-design. The survey found that stakeholders were satisfied with the model of care the group developed. This project highlighted the value of adopting a co-design approach with stakeholders to develop a new model of care.
Islands in the sky – could complex topography help us rewild beyond the fence?
Authors: Brewster Rob , Jameson Tom , Roncolato Francesca , Crowther Mathew S. , Finnerty Patrick B. , Newsome Thomas M.
Published: August 2024

Context The protection of threatened species in fenced safe havens has become a vital component of conservation management in Australia. However, despite their success, fenced safe havens face several ecological and economic constraints. There is a need to explore additional approaches to restore species beyond the fence. Aims To explore naturally occurring mesas as potential ‘sky-island safe havens’, created by natural barriers in elevation and relief, which may restrict the movement of introduced predators and other mammals. Methods We examined species occurrences at a mesa site (Mt. Talaterang in south-east NSW, Australia) as well as a nearby lower-lying site (Little Forest Plateau). We then provide a geospatial analysis of other mesas in NSW to investigate the number of potential sky-island safe havens in the state. Key results Species assemblages differed between the two sites, with red foxes (Vulpes vulpes), dingoes/domestic dogs (Canis dingo/familiaris), and European rabbits (Oryctolagus cuniculus) absent from the mesa site, while Antechinus spp. were not detected from the lower-lying site. Feral cats (Felis catus) occurred at significantly lower densities on the mesa site compared to the lower-lying site. In NSW, we identified 91 other mesas of ≥10 ha with similar topology as Mt. Talaterang. Conclusions Although differences in species assemblages are expected between different habitats, the absence of red foxes and lower number of feral cat detections at the mesa site suggest the need to further explore the potential for mesas in conservation initiatives. Implications Our findings introduce a supplementary conservation strategy that could augment existing fenced safe haven approaches.
Phase retrieval and phaseless inverse scattering with background information
Authors: Hohage Thorsten , Novikov Roman G , Sivkin Vladimir N
Published: August 2024

We consider the problem of finding a compactly supported potential in the multidimensional Schrödinger equation from its differential scattering cross section (squared modulus of the scattering amplitude) at fixed energy. In the Born approximation this problem simplifies to the phase retrieval problem of reconstructing the potential from the absolute value of its Fourier transform on a ball. To compensate for the missing phase information we use the method of a priori known background scatterers. In particular, we propose an iterative scheme for finding the potential from measurements of a single differential scattering cross section corresponding to the sum of the unknown potential and a known background potential, which is sufficiently disjoint. If this condition is relaxed, then we give similar results for finding the potential from additional monochromatic measurements of the differential scattering cross section of the unknown potential without the background potential. The performance of the proposed algorithms is demonstrated in numerical examples. In the present work we significantly advance theoretically and numerically studies of Agaltsov et al (2019 Inverse Problems
35 24001) and Novikov and Sivkin (2021 Inverse Problems
37 055011).
Rational design of the 6e thiolate-protected Au24(SR)18 nanocluster
Authors: Zhai Hongsheng , Liu Man , Wang Endong , Liu Yufang
Published: August 2024

The growth mechanism of thiolate-protected gold nanoclusters (AuNCs) has been advanced, but precise crystal structure information is lacking. Recent mass spectrometry and nuclear magnetic resonance analysis experiments traced the Au24(SR)18 cluster as a non-negligible byproduct intermediate during the reaction between [Au25(SR)18]−, the flagship cluster of the remarkable nanocluster ship, and Au25(SR)19, a cluster with 25 Au atoms but featuring a completely different structure than the [Au25(SR)18]− cluster. However, the precise structure of the Au24(SR)18 cluster is unknown. In this study, a total of seven Au24(SR)18 isomers were constructed using the grand unified model. Density functional theory calculations demonstrated that two of them could be considered quasi-degenerate suggesting that both might coexist in experiments. Geometrical features, electronic structures, and absorption spectra were calculated for potential future comparisons. This work contributes to fully interpreting the growth mechanism of AuNCs .
Cathodoluminescence of polarization-induced energy states at AlGaN/GaN interface
Authors: Chahshouri Fatemeh , Taleb Masoud , Black Maximilian , Mensing Michael , Talebi Nahid
Published: August 2024

Recent progress in manufacturing high-electron-mobility transistors and optoelectronic devices highlights the necessity of understanding the charge dynamics and its impact on the optical properties inside heterostructures. Herein, we study the optical properties of

GaN

/

A

l

0.23

G

a

0.77

N

/

GaN

heterostructures using cathodoluminescence (CL) and photoluminescence (PL) spectroscopy. We explore the influence of generated secondary carriers after electron illumination and their penetration depth on the luminescence spectra. Our findings indicate that a higher laser power intensifies the PL response and establishes Fabry–Perot-like resonances. Furthermore, the intensity of the CL response shows a linear behavior versus the acceleration voltage and the current of electron beams for the yellow luminescence peak. A near-infrared CL peak (740 nm) is observed only when illuminating the sample with high currents that is attributed to the trapping of the secondary electrons within the Schottky barrier and the manipulation of the two-dimensional electron gas and the quantum-confined states within the barrier. Self-consistent Poisson–Schrödinger simulations verify this aspect. This research unveils the intricate charge dynamics associated with the interaction of electron beams with heterostructure systems, paving the way for innovative optoelectronic applications in semiconductor devices.
Tuning the thermal conductivity of silicon nanowires by surface passivation
Authors: Ruscher Céline , Cortes-Huerto Robinson , Hannebauer Robert , Mukherji Debashish , Nojeh Alireza , Srikantha Phani A
Published: August 2024

Using large scale molecular dynamics simulations, we study the thermal conductivity of bare and surface passivated silicon nanowires (SiNWs). For the cross–sectional widths

w
⩽
2

nm, SiNWs become unstable because of the surface amorphization and also due to the evaporation of a certain fraction of Si atoms. The observed surface (in–)stability is related to a large excess energy Δ of the surface Si atoms with respect to the bulk Si, resulting from the surface atoms being less coordinated and having dangling bonds. We first propose a practically relevant method that uses Δ as a guiding tool to passivate these dangling bonds with hydrogen or oxygen, stabilizing the SiNWs. These passivated SiNWs are used to calculate the thermal conductivity coefficient κ. While the expected trend of

κ
∝
w

is observed for all SiNWs, surface passivation provides an added flexibility of tuning κ with the surface coverage concentration c of passivated atoms. Indeed, with respect to the bulk κ, passivation of SiNW reduces κ by 75%–80% for

c
→
50
%

and increases it by 50% for the fully passivated samples. Analyzing the phonon band structures via spectral energy density, we discuss separate contributions from the surface and the core to κ. Our results also reveal that surface passivation increases SiNW stiffness, contributing to the tunability in κ.
Evaluation of plasma process-induced mechanical property change in SiN films using a cyclic nanoindentation technique
Authors: Goya Takahiro , Urabe Keiichiro , Eriguchi Koji
Published: August 2024

Recently, plasma process-induced damage (PID) has garnered significant interest in the design of thin dielectric films implemented in semiconductor devices. Silicon nitride (SiN) films, a material of interest in strain engineering, are found to suffer from PID because they are exposed to various plasmas during device manufacturing processes. Only a limited amount of experimental evidence is available at present regarding plasma-induced mechanical property changes of SiN films. In this study, we investigated the mechanical property change in SiN and SiO2 films using a cyclic nanoindentation technique. We focused on the contact stiffness (S) as the principal mechanical property parameter. Firstly, a single loading/unloading test confirmed an increase in S after Ar and He plasma exposures. Subsequently, we examined the time-dependent features of damaged SiN and SiO2 films under cyclic loading/unloading. From the cyclic test, an increase in S was seen with the number of loading/unloading cycles (N) for both SiN and SiO2 films. A larger increase in S was observed for the damaged SiN, while no significant increase was seen for the damaged SiO2 films. The observed increase in S and its time dependence are attributed to the strain developed by the created defects (e.g. interstitial species) and the reconstruction and stabilization of plasma-damaged Si–N networks with created defects, respectively. The time-dependent S analysis under cyclic loading/unloading is useful for evaluating the effects of PID on the mechanical properties of thin films.
Reversed self-steepening in Si3N4-organic hybrid slot waveguides with engineered nonlinearity
Authors: Zhai Yuke , Xu Lijuan , Ren Kexin , Zhang Lin
Published: August 2024

Dispersion of nonlinearity greatly influences both temporal and spectral evolutions for ultrashort pulses, although difficult to be tailored in a wide spectral range. Here, we show the hardly observable reversed self-steepening in an on-chip Si3N4-organic hybrid slot waveguide with sophisticated dispersion and an increased nonlinear coefficient with wavelength. An octave-spanning supercontinuum with significant red-shift spectral broadening and a rectangle-shaped pulse waveform with a sharp rising edge of 13 fs can be generated. We study the robustness of reversed self-steepening under different operating conditions and reveal its nonlinear dynamics. This deepens the understanding on the dispersion of nonlinearity and helps develop novel nonlinearity-engineered devices for on-chip optical shock formation, pulse shaping, and signal processing in the future.
EM optimization of microwave filter based on long short-term memory–feedforward neural network and transfer functions
Authors: Zhang Xin , Wu Jian , Chai Yong-Qiang , Liu Shui , Peng Yuan
Published: August 2024

An electromagnetic optimization technique based on a long short-term memory–feedforward neural network (LSTM-FNN) and transfer functions is proposed for microwave filter design. The proposed optimization method addresses the situation where a neuro-transfer function model repeatedly trains at each optimization iteration process. The proposed surrogate model combines the LSTM-FNN and polynomial model to map nonlinear relationships between geometric variables and transfer functions. Firstly, by combining the gate mechanism of LSTM with the high generalization ability of an FNN, the proposed LSTM-FNN effectively learns nonlinear relationships between geometric variables and frequency responses at specific frequencies. Secondly, the transfer functions can be accurately approximated via polynomial fitting. Frequency responses at any interesting frequency range can be accurately expressed using the transfer functions. Finally, the trained surrogate model, exploiting the trust-region algorithm, can accurately and efficiently achieve optimization convergence. An example of a low-pass filter (LPF) is adopted to validate the proposed optimization method.
Light-induced fading effects on TL and OSL signals and feasibility of dose re-assessment with PTTL signals in BeO dosimeters
Authors: Aşlar Engin
Published: August 2024

This study aims to investigate both light-induced fading effects on thermoluminescence (TL) and optically stimulated luminescence (OSL) signals under three different light sources (fluorescent, UV-254 and daylight) and dose reassessment with phototransferred TL (PTTL) signals in Beryllium oxide dosimeters. TL and OSL signals were deconvoluted for each light source. Accordingly, variations in the maximum peak temperature, activation energy, peak area value for the TL signal, and intensity and lifetime values for the OSL signal were monitored. Each peak, OSL component, and total area value exhibited different behaviors depending on the light source. Considering the total area condition, the TL intensity decreased by ∼90%, ∼80%, and ∼70% in UV-254, daylight, and fluorescent light exposure, respectively, at the end of the 120 min. On the other hand, the OSL total area intensity faded quickly for both UV-254 and daylight, while it decreased by ∼45% for fluorescent light. According to these results, regardless of TL and OSL measurements, the dosimeters should be kept primarily away from daylight and fluorescent light after irradiation, instead of UV-254, which is rarely encountered in daily life. The feasibility of dose reassessment using PTTL signals under UV-254 light was investigated within a wide dose range from 0.1 to 128 Gy. It is feasible to reassess doses between 0.5 and 32 Gy considering the total area intensity of PTTL signals. In conclusion, PTTL signals can be easily used in fields of the order of Gy, such as in reevaluating doses in radiotherapy applications.
Flavor identification based on olfactory-taste synesthesia model and hybrid convolutional neural network-random forest
Authors: Zheng Wenbo , Pan Guangyuan , Zhu Fengzeng , Zhang Ancai
Published: August 2024

The bionic-based electronic nose (e-nose) and electronic tongue (e-tongue) show satisfactory performance in flavor analysis. Traditional flavor analysis of the e-nose and e-tongue systems focuses on data fusion, and the effects of the bionic characteristics on the flavor analysis performance are rarely studied. Motivated by this, a method, including an olfactory-taste synesthesia model (OTSM) and a convolutional neural network-random forest (CNN-RF), is proposed for the effective identification of flavor substances. The OTSM is developed for human nerve conduction mechanisms to enhance the bionic characteristics of the e-nose and e-tongue systems and is combined with a CNN-RF model for flavor identification. The results show that, first, when stimulated by e-nose and e-tongue data, physiological 1/f characteristics and synchronization are shown using the OTSM. The enhancement effects on the bionic characteristics of the fusion system are validated using the 1/f characteristics and synchronization. Second, the fully connected layer for the CNN is replaced by RF to improve the identification performance of flavor substances. Finally, CNN-RF is evaluated in comparison with other flavor recognition models and ablation studies to confirm its effectiveness. By comparison, the best recognition performance, including the accuracies of 96.67%, 96.67%, and 95.00%, the F1-scores of 96.65%, 96.66%, and 94.95%, and the kappa coefficients of 96.03%, 96.10%, and 93.44%, for five beers, five apples, and four mixed solutions, respectively, is obtained by CNN-RF. In conclusion, excellent flavor identification for the fusion system is achieved using the OTSM and CNN-RF models.
DFT analysis of Re-modified WSe2 monolayers for adsorption of CO, C2H2, and C2H4
Authors: Sarkar Suman , Debnath Papiya , De Debashis , Chanda Manash
Published: August 2024

The sensing performances of the Rhenium (Re) doped Tungsten Diselenide (WSe2) monolayer for detecting small gas molecules such as carbon monoxide (CO), acetylene (C2H2), and ethylene (C2H4) have been analyzed in this paper. Density functional theory and non-equilibrium Green’s function have been used to examine the electrical and geometric structures of re-adorned WSe2 monolayer when subjected to dissolved gas analysis gases in the transformer oil. Hence, the electrochemical characteristics like Band diagram and density of states are detailed. Adsorption systems’ recovery capabilities, Mulliken population, and adsorption energy have been examined to determine their stability. Studies also show that Re-doped WSe2 monolayer exerts deformation and as a result, the band gap narrowed down. At ambient temperature (273 K–300 K), the Re-doped WSe2 exhibits better adsorption of C2H4 over C2H2 and CO as the C2H4 has higher adsorption energy compared to the C2H2 and CO. Besides, V–I characteristics of the Re doped WSe2 layer after adsorption of the CO, C2H2, and C2H4 are detailed which signifies the efficacy of the Re doped WSe2 monolayer.
A coupled crystal inelasticity-phase field model for crack growth in polycrystalline nitinol microstructures
Authors: Maloth Thirupathi , Appel Pheobe , Erlebacher Jonah , Ghosh Somnath
Published: August 2024

This paper introduces a comprehensive computational framework, comprising a finite deformation crystal inelasticity constitutive model and phase field model, for modeling crack growth in superelastic nitinol polycrystalline microstructures. The crystal inelasticity model represents crystal stretching and lattice rotation from elastic mechanisms, as well as local inelastic deformation due to austenite-martensite phase transformation. The phase field formulation decomposes the Helmholtz free energy density into stored elastic energy, phase transformation energy, and crack surface energy components. The elastic energy accounts for tension-compression asymmetry with the formation of the crack through a spectral decomposition. Kinetic Monte Carlo simulations generate equilibrium area fractions of different surface orientations, which serve as weights for the surface energy. An adaptive wavelet-enhanced hierarchical finite element (FE) model is introduced to alleviate high computational overhead in phase field crack simulations. Simulations with the coupled inelasticity phase field model are conducted under various loading conditions including Mode-I tension, a quasi-static Kalthoff experiment, and cyclic loading of polycrystalline microstructures. Crack propagation is effectively predicted by this model, providing valuable insights into the material mechanical behavior with growing cracks.
Tensile strength prediction of steel sheets: an insight into data-driven models, dimensionality reduction, and feature importance
Authors: Millner Gerfried , Mücke Manfred , Romaner Lorenz , Scheiber Daniel
Published: August 2024

In this work we apply data-driven models for predicting tensile strength of steel coils from chemical composition and process parameters. The data originates from steel production and includes a full chemical analysis, as well as many process parameters and the resulting strength properties from tensile tests. We establish a data pre-processing pipeline, where we apply data cleaning and feature engineering to create a machine-readable dataset suitable for various modeling tasks. We compare prediction quality, complexity and interpretability of pure machine learning (ML) models, either with the full feature set or a reduced one. Dimensionality reduction methods are used to reduce the number of features and therefore reduce complexity, either with a smart selection method or feature encoding, where features are combined and the included information is preserved. In order to determine key features of our models, we are investigating feature importance ratings, which can be used as a feature selection criteria. Furthermore, we are highlighting methods to explain predictions and determine the impact of every feature in every observation applicable for any ML model.
Dark-field microscopy studies of single silicon nanoparticles fabricated by e-beam evaporation technique: effect of thermal annealing, polarization of light and deposition parameters
Authors: Sahoo Sibanisankar , Naik Aadesh M , Laha Ranjit , Dantham Venkata R
Published: August 2024

Herein, we report the dark-field microscopy studies on single silicon nanoparticles (SiNPs) fabricated using different deposition parameters in the electron beam evaporation technique. The morphology of the fabricated SiNPs is studied using the Atomic Force Microscope. Later, for the first time, the effect of thermal annealing and deposition parameters (i.e. beam current and deposition time) on the far-field scattering images and spectra of single SiNPs is studied using a transmission-mode dark-field optical microscope to estimate the wavelength locations and full-width at half maxima of the optical resonances of single SiNPs. Finally, the role of polarization of incident light on the optical resonances of single SiNPs is also studied by recording their scattering images and spectra.
Nanoengineered pure Fe in a citrate matrix (Fe–CIT) with significant and tunable magnetic properties
Authors: Getahun Yohannes , Das Debabrata , Ramana C V , El-Gendy Ahmed A
Published: August 2024

This work demonstrates the synthesis and characterization of Fe nanoparticles surrounded by a citrate (CIT) matrix prepared at various temperatures and concentrations of metal, capping agent and reducing agent at standard conditions. We study the effect of reactant ratio and reaction temperature on the magnetization of the produced nanoparticles and their crystal structure. We found that for optimal metal concentrations, magnetic saturation increases with increase in the concentration of capping and reducing agents but decreases as the temperature of the reaction increases. Synthesis conditions were tailored to reveal nucleation of particles with average sizes ranging from 24 to 105 nm and a spherical shape. The ultra-high saturation magnetization of 228 emu g−1 obtained for samples prepared at a metal precursor concentration of 27.8 mol l−1 was attributed to the formation of small magnetic domains. Energy band gap measurements revealed a band gap energy for the Fe nanoparticles in the CIT matrix which is associated with CIT concentration and/or possible formation of a few thin layers of iron oxide shell and does not have a significant effect on the magnetic properties of the samples. Herein, we demonstrate that the synthesis parameters are crucial for the nucleation of Fe-CIT nanoparticles tailoring their magnetizatic properties as well as their potential for different applications.
Nucleic acid-functionalized gold nanoparticles as intelligent photothermal therapy agents for precise cancer treatment
Authors: Tang Hongmei , Zhang Xuetao , Bao Yuyan , Shen Huazhen , Fan Minglan , Wang Yangchen , Xiang Siyun , Ran Xiang
Published: August 2024

We present an intelligent photothermal therapy agents by functionalizing gold nanoparticles with specific nucleic acid sequences. Hairpin nucleic acids are modified to the nanoparticles, forming AuNPs-1 and AuNPs-2. Upon infiltrating cancer cells, these nanoparticles undergo catalytic hairpin assembly in the presence of target miRNA, leading to aggregation and subsequent photothermal conversion. Under near-infrared laser irradiation, aggregated gold nanoparticles exhibit efficient photothermal conversion, selectively damaging cancer cells. This approach offers heightened selectivity, as nanoparticles only aggregate in environments with cancer biomarkers present, sparing normal cells. Cytotoxicity assays confirm minimal toxicity to normal cells. In vivo studies on mice bearing solid tumors validate the system’s efficacy in tumor regression. Overall, this study highlights the potential of nucleic acid-functionalized gold nanoparticles in intelligent and selective cancer photothermal therapy, offering insights for targeted diagnosis and treatment development.
Construction of CDs@β-CD@CCM ratiometric fluorescence probe for FRET-based ClO–-sensing
Authors: Xu Ruoqian , Hu Zhongfei , Dong Xuemei , Xiao Xuan , Ding Yujie
Published: August 2024

β-Cyclodextrin (β-CD)—functionalized carbon quantum dots (CDs) loaded with curcumin (CCM) were used for ClO– sensing with high sensitivity and selectivity. This fluorescence resonance energy transfer (FRET)-based sensor was created through attaching CCM to the CDs via β-CD linker. CCM could get into the interior of β-CD triggering the FRET from CDs to CCM, providing an ‘off’ state of the CDs. However, the effect of FRET was weakened by the ClO–, because the o-methoxyphenol structure from CCM was oxidized to be benzoquinone. The fluorescence intensity of CDs@β-CD@CCM at 440 nm can be heightened and 520 nm from CCM can decrease along with the increased ClO–. Therefore, a ratiometric fluorescence probe for ClO– sensing is successfully constructed. It conforms to a polynomial curve equation which is I440/I520 = −0.0268 + 0.0315 CClO
–+ 0.0055[CClO
–]2 (R
2 = 0.9958) between 0 and 18.4 μM ClO–. Furthermore, we also obtain excellent results using this spectrophotometric method for ClO–-sensing in pure water and commercial disinfectants, which afford potential in the environment monitoring area. We expect this sensing platform could be helpful in other analogous probes in relevant fields.
Scatter estimation and correction using time-of-flight and deconvolution in x-ray medical imaging
Authors: Rossignol Julien , Bélanger Gabriel , Fromont Maëlle , C Therrien Audrey , Fontaine Réjean , Bérubé-Lauzière Yves
Published: August 2024

Objective. Time-of-flight (TOF) scatter rejection requires a total timing jitter, including the detector timing jitter and the x-ray source’s pulses width, of 50 ps or less to mitigate most of the effects of scattered photons in radiography and CT imaging. However, since the total contribution of the source and detector to the timing jitter can be retrieved during an acquisition with nothing between the source and detector, it can be demonstrated that this contribution may be partially removed to improve the image quality. Approach. A scatter correction method using iterative deconvolution of the measured time point-spread function estimates the number of scattered photons detected in each pixel. To evaluate the quality of the estimation, GATE was used to simulate the radiography of a water cylinder with bone inserts, and a head and torso in a system with total timing jitters from 100 ps up to 500 ps full-width-at-half-maximum (FWHM). Main results. With a total timing jitter of 200 ps FWHM, 89% of the contrast degradation caused by scattered photons was recovered in a head and torso radiography, compared to 28% with a simple time threshold method. Corrected images using the estimation have a percent root-mean square error between 2% and 14% in both phantoms with timing jitters from 100 to 500 ps FWHM which is lower than the error achieved with scatter rejection alone at 100 ps FWHM. Significance. TOF x-ray imaging has the potential to mitigate the effects of the scattering contribution and offers an alternative to anti-scatter grids that avoids loss of primary photons. Compare to simple TOF scatter rejection using only a threshold, the deconvolution estimation approach has lower requirements on both the source and detector. These requirements are now within reach of state-of-the-art systems.
Gain enhancement of mm-wave antenna using graded index lens integrated frequency selective surface for 5G NR FR2 applications
Authors: Babu K Vasu , Sree Gorre Naga Jyothi , Das Sudipta , Ali Wael , Altameem Torki , El-Shafai Walid
Published: August 2024

In this study, the gain of a printed antenna is boosted for utilization in 5G systems by employing a phase-oriented graded index-type lens system. In the prescribed design, various metamaterial unit cells are arranged as arrays with radial phases for the graded meta lens to optimize transmission characteristics. The suggested arrangement creates a meta lens with spatially varying surface impedance and locally varying refractive index, allowing the conversion of spherical wavefronts into planar wavefronts for beam collimation in the 5G band. The focal length-to-diameter ratio (f/d) is fixed at 0.38 in this prescribed design. The integration of the FSS structure with the patch antenna enhances the efficiency above 98% and increases gain by 2.635dBi owing to the focusing effect of the properly placed lens. The prescribed planar lens is easy to realize during manufacturing compared to 3D lenses. The meta lens integrated patch yields a gain of around 8.936dBi at 29 GHz. The performance of the lens antenna is evaluated through simulation studies and then validation of results is performed with experimental arrangement to ensure accuracy and reliability of the suggested methodology for gain enhancement of the functioning antenna at FR2 5G spectrum.
Lattice stick number 15 is unattainable for non-splittable links
Authors: Huh Youngsik , No Sungjong , Oh Seungsang
Published: August 2024

In this paper, we explore mathematical links, defined as closed curves embedded in 3D space. Knot theory studies these structures, which also occur in real-world biopolymers like DNA. Lattice links are links in the cubic lattice. For scientific simulations or statistical studies, links are simplified to lattice links. The lattice stick number, denoted as s

L
(K), is the minimum number of lattice sticks needed to represent a link K in the cubic lattice. In previous study, it was shown that only two non-trivial knots and six non-splittable links have s

L
≤ 14: specifically,

s

L

(

2

1

2

)
=
8

,

s

L

(

3

1

)
=

s

L

(

2

1

2

♯

2

1

2

)

=

s

L

(

6

2

3

)

=

s

L

(

6

3

3

)
=
12

,

s

L

(

4

1

2

)
=
13

, and

s

L

(

4

1

)
=

s

L

(

5

1

2

)
=
14

. Recent study has further revealed that no knot can have s

L
= 15. In this paper, we prove that lattice stick number 15 is not attainable for non-splittable links. As a corollary, eleven non-splittable links with s

L
=16 are presented.
Asymptotic behavior of the indicator function in the inverse problem of the wave equation for media with multiple types of cavities
Authors: Kawashita Mishio , Kawashita Wakako
Published: August 2024

This paper discusses an inverse problem of recovering information about cavities by measuring the solutions of a wave equation. When the medium has multiple types of cavities and the distances from the observation site to the ‘positive cavity’ and to the ‘negative cavity’ coincide, the sign of the indicator function of the enclosure method cannot be determined. Thus, sign cancellation may occur, and information may be lost. In this study, by using an asymptotic solution and examining the top term of the indicator function in detail, it is shown that the shortest distance to the cavity can be obtained, even in the above case.
Destriping model for adaptive removal of arbitrary oriented stripes in remote sensing images
Authors: Hamadouche Sid Ahmed , Boutemedjet Ayoub , Bouaraba Azzedine
Published: August 2024

Destriping in remote sensing image processing remains a challenging problem, particularly when dealing with stripe noise of arbitrary orientations. Conventional methods struggle to eliminate oblique stripes, leaving a crucial gap in the production of higher-level remote sensing products. In response, we propose a novel destriping model, the Adaptive Stripe Noise Removal (ASNR) Method, designed to adapt to different orientations of stripe noise, aiming for accuracy, robustness, speed, and simplicity. The paper first addresses the conventional challenges in stripe removal, emphasizing the unintended loss of information during the process. To overcome this, we conduct a detailed study of stripe noise characteristics, employing traditional Fast Fourier Transform (FFT) for stripe orientation approximation. However, conventional techniques using spatial representations risk damaging detailed structures. To go beyond these limitations, the proposed method combines spectral processing technology with an image guidance mechanism. This approach aims to generate a guided image that retains both denoised features and important details. In the frequency domain, the method corrects the stripe image by estimating a guidance image. Experimental results, both qualitative and quantitative, demonstrate the superiority and stability of the proposed method in removing stripe noise and preserving image details without introducing artifacts. The novel approach fills a critical gap in destriping methods, offering a fast, accurate, and adaptable solution for arbitrary orientations of stripe noise in remote sensing images.
A theoretical approach to study oxide-based perovskite materials XTiO3 (X = Be, Mg, Ca, Sr and Ba) for photovoltaic applications
Authors: Das Shayeri , Dey Sujoy Kumar , Ranjan Prabhat , Chakraborty Tanmoy
Published: August 2024

Oxide-based perovskite materials have a large application in fuel and hydrogen sensors, non-volatile random access memory devices, semiconductor fabrications, optoelectronic, thermoelectric and photovoltaic devices. In this report, equilibrium geometries, and optoelectronic properties of oxide-perovskite materials XTiO3 (X = Be, Mg, Ca, Sr and Ba) are investigated through Conceptual Density Functional Theory (CDFT) technique. The HOMO–LUMO energy gap obtained from functional B3LYP/LANL2DZ and B3PW91/LANL2DZ are observed in the range of 1.201 eV–4.647 eV and 1.519 eV–4.903 eV respectively, which justifies their applications in solar cells and optoelectronic devices. HOMO–LUMO energy gap shows a downward trend when materials travel from Be to Mg to Ca to Sr to Ba, except for BaTiO3 in B3PW91/LANL2DZ. BeTiO3 displays the maximum value of HOMO–LUMO gap, hardness and electronegativity value. Hardness and softness of these substances are found between 0.600–2.452 eV and 0.204–0.788 eV respectively whereas refractive index and dielectric constant of XTiO3 are observed in the range of 2.017–3.684 and 4.067–13.574 respectively. Across all relationships, XTiO3’s dielectric constant and refractive index show a rising pattern from Be to Mg to Ca to Sr to Ba, except for BaTiO3 computed using B3PW91/LANL2DZ. The lowest refractive index and dielectric constant are displayed by the BeTiO3. TD-DFT calculation is performed to understand the absorption spectra of these materials. Optical transition energy and wavelength of XTiO3 are found between 0.339–3.535 eV and 350.68–3656.15 nm respectively. An interesting relationship is established between HOMO–LUMO energy gap, optical transition energy and wavelength of XTiO3 materials. The investigated compounds exhibit a linear pattern between HOMO–LUMO energy gap and optical transition energy whereas wavelength shows an inverse trend. MEP of these compounds are also discussed.
Effect of layering sequence and jujube fruit seed addition on the mechanical, water absorption and bio-degradation properties of Indian almond/peepal hybrid composites
Authors: Srinivasan R , Jayaraman M
Published: August 2024

Hybrid composite comprised fibers like peepal and Indian almond was fabricated, with the addition of natural filler such as jujube fruit seed particles aimed at enhancing composite performance. The impact of jujube fruit seed particles and layering sequence on the mechanical properties, water absorption and bio-degradation of the composites was investigated. Initially, two composite types, IA/P/IA (Indian almond/Peepal/Indian almond) and P/IA/P (Peepal/Indian almond/Peepal), were produced using hand layup practice, altering layering sequence of fibers. Based on tensile test results, the P/IA/P composite emerged as the optimal choice due to the denser packing of high-strength peepal fiber. Subsequently, jujube fruit seed particles were incorporated into the P/IA/P composite at varying weight percentages ranging from 2.5 to 10 with a step size of 2.5. The effect of jujube fruit seed particles on the performance of the P/IA/P composite was examined. The P/IA/P/7.5 wt% jujube composite demonstrated superior tensile, flexural, impact, and hardness properties, recording values of 82 MPa, 98 MPa, 5.2 kJ m−2, and 86 shore-d, respectively. These values were 15.4%, 22.5%, 20.9%, and 4.8% higher than those of the P/IA/P composite. The P/IA/P/10 wt% jujube composite demonstrated minimal water absorption, with only 8% recorded over a 12-day period, as well as limited mass loss, totaling 27% over 60 days. Consequently, this research suggests that the P/IA/P/7.5 wt% composite holds promise for industrial applications.
Aloe vera-synthesized Ag nanoparticles loaded on PVA/chitosan as biodegradable and antibacterial film for food storage
Authors: Tran Nhung Thi
Published: August 2024

We have developed a novel, eco-friendly, and active food packaging film by incorporating green-synthesized silver nanoparticles (AgNPs) into polyvinyl alcohol (PVA) and chitosan matrices. The AgNPs were in situ and green synthesized in high-yield by using Aloe vera extract as a reducing agent and chitosan as a stabilizing agent at high temperature. The obtained AgNPs exhibit quasi-spherical shapes and tunable size in the range 20 ∼ 30 nm by controlling the content of AgNO3 precursor in the growth solution. The in situ synthesis enables the homogeneous distribution of AgNPs throughout the films and eliminates the need for purification. The effect of the loaded amounts of Aloe vera-synthesized AgNPs on the film characteristics was investigated. The results show that the obtained AgNPs-loaded films exhibit excellent mechanical properties (tensile strength of 36.7 MPa and elongation at break of 213.9%) and superior bacterial killing and inhibition effects against E. coli. Moreover, the incorporation of green-synthesized AgNPs into the polymeric films also results in a significant improvement in the contact angles formed between the film surface and glycerol droplets, enhanced thermal stability, and a reduction in water swelling and water solubility. All these results highlight the great potential of these biodegradable and antibacterial membranes as an alternative to petroleum-based plastics in food packaging and preservation.