bluuebunny/crossref_metadata_2025 huggingface dataset:
A multi-source data fusion driven power field effect transistor health state assessment and remaining useful life prediction method
Authors: Chen Gaige , Zhang Yuzhe , Huang Jun , Wang Xianzhi , Kong Xianguang
Published: August 2024

The metal oxide semiconductor field effect transistor (MOSFET) is subjected to various stresses due to the external and internal operating environments, leading to ageing and failure of the device. With multiple degradation mechanisms, a single piece of information can no longer fully reflect the health state of MOSFETs, so how to use multi-source data to characterise the state of the device and predict the remaining useful life (RUL) is an issue worth exploring. To address this problem, a method for constructing health indicators (HI) as well as predicting RUL using multi-source data is proposed. In this method, firstly, the features are computed by selecting the appropriate ageing signal from the ageing mechanism. Secondly, the extracted features are filtered using Pearson’s algorithm to find the features that are strongly correlated with longevity. Then, the filtered features are merged by dimensionality reduction using the kernel principal component analysis algorithm and the HI is constructed from the reduced result. Finally, an unsupervised clustering algorithm is used to classify the states based on the data distribution in HI, and the filtered features are used as input to the grey wolf optimisation bidirectional long short-term memory neural network to predict the RUL of the device. In this paper, the proposed method is validated using data from the MOSFET Accelerated Aging Experiment at the NASA Ames Centre of Excellence for Prediction. The results show that the method is able to achieve good results in health state assessment and RUL prediction of MOSFETs. The proposed method is an effective and comprehensive strategy that is more helpful for the operation and maintenance of electronics.
Self-similar blow-up solutions in the generalised Korteweg-de Vries equation: spectral analysis, normal form and asymptotics
Authors: Chapman S Jon , Kavousanakis M , Charalampidis E G , Kevrekidis I G , Kevrekidis P G
Published: August 2024

In the present work we revisit the problem of the generalised Korteweg–de Vries equation parametrically, as a function of the relevant nonlinearity exponent, to examine the emergence of blow-up solutions, as traveling waveforms lose their stability past a critical point of the relevant parameterp, here atp = 5. We provide anormal formof the associated collapse dynamics, and illustrate how this captures the collapsing branch bifurcating from the unstable traveling branch. We also systematically characterise the linearisation spectrum of not only the traveling states, but importantly of the emergent collapsing waveforms in the so-called co-exploding frame where these waveforms are identified as stationary states. This spectrum, in addition to two positive real eigenvalues which are shown to be associated with the symmetries of translation and scaling invariance of the original (non-exploding) frame features complex patterns of negative eigenvalues that we also fully characterise. We show that the phenomenology of the latter is significantly affected by the boundary conditions and is far more complicated than in the corresponding symmetric Laplacian case of the nonlinear Schrödinger problem that has recently been explored. In addition, we explore the dynamics of the unstable solitary waves forp > 5 in the co-exploding frame.
Innovative approach of teaching ray-optics in the classroom
Authors: Rathi Mayank , Shukla Ravi Kant , Tiwari Prashant , Kushwaha Govind , Gupta Priyanshu , Rana Ankush , Garg Amit
Published: August 2024

The present work discusses an innovative approach to teaching ray optics for students of class X. The school students were taught various concepts related to ray optics viz. Reflection, refraction, lateral displacement, mirrors, lenses, their types and terminologies, thin and thick lens, power of a lens, all cases of image formation in lenses, total internal reflection and its applications, human eye, its defects and corrections, making of telescope and microscope through practical demonstrations and hands-on approach using a self-conceived Ray Optics Kit. This activity was done independently in twenty two schools of Delhi, both government and private, with a massive total participation of 1200 students as part of SPIE Optics Outreach Activity. SPIE@ANDC Student Chapter members were trained at the college and they followed ‘Train the Trainer’ approach to create a pool of more than fifteen students who collectively conducted the workshops in teams in each of these schools. The student performance was assessed through a pre and post test as well as using a feedback form. An improvement of 65% in students’ performance was observed as indicated by comparing their pre-test and post-test results. The students as well as teachers gave a highly appreciative feedback of the whole activity. The feedback on their social media pages is a testimony of the success of the activity. Each school was awarded a Ray Optics Kit so as to make teaching and learning of ray optics interesting and engaging for batches in the future academic years.
A novel quantum security multi-party extremum protocol in a d-dimensional quantum system
Authors: Lu Yaohua , Ding Gangyi
Published: August 2024

Secure multi-party extremum computation (SMEC) is a specific application scenario of secure multi-party computation, which allows multiple participants to compute the extremum of data without disclosing private information. The extremum includes maximum, minimum, sum of extremums, and difference of extremums. SMEC has wide applications in financial transactions, market analysis, sports events, healthcare, etc. Current protocol research mainly exists in the classical domain and cannot withstand quantum computing attacks. To address this issue, we propose a novel QSME protocol based on a d-dimensional quantum system, capable of computing the maximum and minimum values among multi-party data under unconditional security, and can compute the sum and difference of extremums without disclosing the maximum and minimum values, to adapt to complex application scenarios. The article proposes a coding method for a d-dimensional quantum system to further enhance security, provides correctness analysis, security analysis, robustness analysis, and comparative analysis, and proposes an experimental method for a d-dimensional quantum system to verify the effectiveness of the protocol, demonstrating strong practicality.
Structural origin of spin-splitting anisotropy in janus dichalcogenides monolayers under pressure
Authors: Caturello Naidel A M S
Published: August 2024

Janus transition-metal dichalcogenides (TMDs) have drawn a great deal of attention because of their mirror plane symmetry breaking that allows the emergence of a built-in out-of-plane dipole which determine superior piezoelectric and spin-related properties. Furthermore, it has been shown in the recent literature that pressure application is capable of modulating spin-related phenomena in this class of materials. Generally, the spin-splitting presence in real systems is explored in terms of point group symmetry reduction using solely group theory arguments. However, we seek to associate the enhancement of spin-splitting in Janus TMDs monolayers by searching the most important local asymmetries responsible for the symmetry lowering that leads the monolayer larger spin-splitting energies. In this sense, we seek to unveil a possible structural descriptor that correlates with subbands splitting magnitude in Janus TMDs. To accomplish this, we performed a detailed first-principles investigation into WSSe Janus monolayers under biaxial in-plane strain to find that pressure induces a symmetry lowering from the C
3v
to the C

s
point group. From these observations, we found that in-plane angle asymmetries between the chalcogens yield a distortion metric that can serve as a descriptor for enhanced spin-splitting in Janus WSSe since it strongly correlates with spin-splitting energies. Hence, our work establishes that, rather than solely global symmetry analysis, specific local distortions provide a key design principle to achieve strong spin-splitting in 2D Janus TMDs.
Bayesian estimation of some reliability characteristics for Nakagami model using adaptive progressive censoring
Authors: Nassar Mazen , Alotaibi Refah , Elshahhat Ahmed
Published: August 2024

The focus of this research is to clarify both conventional and Bayesian parametric estimation methods for the Nakagami distribution making use of adaptive progressive Type II censored data. From a classical estimation perspective, two estimation methods are considered: maximum likelihood and least squares estimations. Along with the model parameters, three reliability metrics are estimated using point and interval estimation. Bayes estimates with gamma and inverse gamma priors are investigated by employing the squared error loss function. The Bayes computations are created using the Markov Chain Monte Carlo technique. Moreover, the classical and Bayesian intervals are also taken into consideration. For evidence of the effectiveness of the given methodologies, a simulation study and three applications from the physics, chemistry, and engineering domains are explored. Lastly three optimality criteria are applied to the stated data sets to pick the best progressive censoring strategy.
Vibration-rotational alternating-parity spectra of even–even nuclei with effective triaxiality
Authors: M S Nadirbekov , Bozarov O A , Kudiratov S N , Minkov N
Published: August 2024

In the present work, a model combining vibration-rotational motion and effective triaxiality is developed for even–even nuclei with quadrupole and octupole deformations. The Davidson potential is used to solve the radial part of the vibration-rotational Schrödinger equation in the axial quadrupole and octupole variables. In an adiabatic approximation the contribution of the angular variable in the components of the moments of inertia is taken as a constant after which the triaxial-rotor energy is obtained. As a result the alternating-parity spectrum and wave functions of the nucleus with quadrupole-octupole degrees of freedom are obtained. The proposed model is used to describe the yrast and first-non-yrast alternating-parity bands of the even–even nuclei 150Nd, 154Sm, 154,160Gd, 156Dy, 162,164Er, 172Yb, 230,232Th, 230,232,234,236,238U and 238,240Pu. The relevance of the model for taking into account the collective quadrupole-octupole modes in a rather complete form is pointed out.
Electron impact excitation of bismuth
Authors: Sahoo Aloka Kumar , Sharma Lalita
Published: August 2024

The present study investigates the electron impact excitation of bismuth from the ground state 6p3
4S3/2 to the excited state 6p27s 4P1/2. Motivated by the latest measurements by Marinković et al [J. Phys. B, 49 23 520 (2016)], relativistic distorted wave calculations are performed to obtain the differential and integrated cross sections for incident electron energies at 10, 20, 40, 60, 80, and 100 eVs. These results are compared with the available experimental data and a good agreement is observed. Our results represent the first theoretical work to provide such a comparison. Additionally, we report the generalized oscillator strengths derived from our calculated differential cross sections.
Impact of charge and non-minimal fluid-geometry coupling on anisotropic interiors
Authors: Naseer Tayyab , Sharif M
Published: August 2024

This paper explores the interior configuration of various charged anisotropic compact models within the framework of

f
(
R
,
T
,

R

λ
η

T

λ
η

)

gravity. The chosen model in this theory is represented by

R
+
γ

R

λ
η

T

λ
η

, where γ is a real-valued parameter. We adopt a static spherical metric to describe the interior of compact strange stars and derive the corresponding field equations. The solution to these equations is then obtained using the Finch-Skea metric and a linear equation of state. Taking the radius and mass of the compact star model 4U 1820-30 as a case study, we investigate the impact of charge and modified corrections on its internal distribution. The stability of the resulting model is also determined within a specific range of γ. Additionally, we determine the values of the model parameter through the vanishing radial pressure constraint, aligning with the experimental data of eight different stars. Our findings indicate that the resulting model adheres to the conditions necessary for physically relevant interiors, particularly in the case of lower charge.
Trapezoidal units for (0,±1) and (±1,0) splitter in the terahertz band
Authors: Huang Yongyuan , Wang Bo , Huang Xu
Published: August 2024

This paper presents a two-dimensional grating splitter based on a trapezoidal array. Under vertical incidence of light in the terahertz band at 2.52 THz, it is possible to suppress the (0,0) order, which has an efficiency of 0.5%, while simultaneously achieving high-efficiency outputs for the (0,±1) and (±1,0) orders, with efficiencies of 25.1% and 24.7%, respectively. And it has good uniformity and extinction rate, where the uniformity (E

U
) is 99.1% and the extinction rate (E

T
) is 0.07 dB. The research process uses the finite element method (FEM) to optimize the grating parameters, and the corresponding grating parameters are the optimal solution when the target diffraction order efficiency is optimal. In order to verify the feasibility of practical applications of gratings, the bandwidth ranges of the grating parameters are discussed, and the results show that the grating parameters all possess a sizable bandwidth range. Therefore, this work has a promising application in the fields of 3D imaging and reconstruction, microscopy technology, and it also provides a new and efficient scheme for modeling 2 × 2 splitters.
DeepOpt: a deep learning optimized privacy preservation framework for cyber-physical systems
Authors: Bindra Sandeep Singh , Aggarwal Alankrita
Published: August 2024

Privacy preservation and security enhancement are the key components of any network architecture due to advanced attack procedures. Cyber-Physical Systems (CPS) also need a mitigation and prevention strategy to deal with cyber threats. The existing approaches majorly deal with attack detection and focus on one or two attacks at a time. With this focus and demand of the CPS, this work proposes a deep learning optimized privacy preservation framework called DeepOpt. This proposed framework prevents the network from attackers and maintains security by classifying multiple attackers simultaneously using deep learning architecture. The proposed framework initializes privacy preservation using the trust-based approach and a hybrid optimization algorithm. In this, the network is divided into different zones, and each zone is secured using trust parameters with additional verification by secure hash function. The hybrid optimization selects the communication path using trust and energy that returns the attack-free path. This proposed architecture is simulated over different network scenarios with or without attacker nodes, and their traces are labeled to train the proposed deep convolutional neural network architecture. Finally, these models are integrated, and their performance is analyzed in different network scenarios and the presence of five different attackers such as blackhole, wormhole, man-in-the-middle attack, spoofing, and distributed denial of service. The simulation results, with improvement in detection accuracy, packet delivery ratio, and other performance factors, indicate the effectiveness of the proposed framework for both prevention and mitigation. Hence, this overall architecture preserves the privacy of CPS even in multifarious dynamic network scenarios.
Polyaniline/reduced graphene oxide nanocomposites for electrochemical and solar cell applications
Authors: Mohan Sonima , Vellakkat Mini , U Reka
Published: August 2024

Polyaniline nanocomposites are synthesized via in situ chemical oxidation method by reinforcing reduced graphene oxide nanoparticles of various weight percentage. Structural, optical, thermal and electrochemical studies are performed to know the significance of introducing reduced graphene oxide into polyaniline and to analyse the importance of filler weight percentage in determining various properties of the nanocomposites. X-ray diffraction peak intensity is appeared to be maximum for nanocomposite doped with 2% filler. This composite shows minimum crystallite size and maximum photoluminescence intensity. Maximum ID/IG ratio obtained for 2% filler added nanocomposite from Raman spectroscopy studies proved that the presence of more surface defects and recombination of charge carriers are the reasons for enhanced photoluminescence. Thermal stability is found to be better for a nanocomposite with 1% reduced graphene oxide and obtained a mass retention of 60% even after heating up-to 600 °C. SEM images give various shapes of nanocomposite such as nanorods, spherical nanoparticles and button shaped nanocomposites for different filler weight percentage. Carbon to oxygen ratio is observed to be decreased as the filler percentage increased from 1% to 4% in SEM-EDAX analysis. Polymer nanocomposite with 1% reinforcement possess maximum UV and visible absorption and is found to be decreased as filler concentration increased from 1 to 4%. Electrochemical analysis is performed for polyaniline and 1% reduced graphene oxide reinforced polyaniline nanocomposite. Specific capacitance of the electrode is obtained as 212 F g−1 and 609 F/g for polyaniline and nanocomposite respectively at a scan rate of 0.01 V/S. Solar cell device performance study shows that power conversion efficiency is 5.54% for 1% reduced graphene oxide nanocomposite, 4.7% for 2% reinforced, 4.16% for 3% filler and 3.61% for 4% nanocomposite.
Ferromagnetism in heavily Fe-doped GaAs: a DFT study
Authors: Zarpellon J , Mosca D H , Varalda J
Published: August 2024

Computational calculations based on density functional theory were carried out to investigate ferromagnetism in gallium arsenide (GaAs) heavily doped with Fe atoms that can substitutionally occupy gallium (Ga) or arsenic (As) sites in the zinc-blende-like crystal structure. The calculations were performed within the spin polarized density functional theory (DFT) and generalized gradient approximation (GGA) with full potential linearized augmented plane wave (FP-LAPW) method. We investigate and discuss the ab initio calculation results focusing on properties intrinsically important for spintronic applications, such as spin polarization and magnetic anisotropy. The density of states (DOS) was calculated with substitution of Fe atoms in the As and Ga sites, giving the electronic properties, as well as the magnetic ground state. According to DFT calculations, heavily doped GaAs with 25 at. % of Fe becomes a ferromagnetic metal with spin polarization as high as 69% at Fermi level. This is corroborated by experimental results previously published in literature.
Controlled lateral positioning of NV centres in diamond by CVD overgrowth
Authors: Lang Nicola , Mathes Niklas , Götze Arne , Reinke Philipp , Schreyvogel Christoph , Iannucci Robert , Giese Christian , Vidal Xavier , Knittel Peter
Published: August 2024

A challenge to this day in the development of diamond devices for quantum applications is the laterally defined and closely spaced positioning of nitrogen-vacancy centres with exceptional coherence properties. Here, we demonstrate a maskless, implantation-free method for the controlled in-plane positioning of NV centres using a combination of focused ion beam (FIB) milling, plasma etching and nitrogen-doped diamond growth. The Ga+ ion beam milling resulted in 1 μm × 1 μm cavities with depths of up to 450 nm, each cavity exhibiting the four [111]-oriented diamond facets after pure hydrogen plasma treatment and a depth of 700 nm. Low-methane, nitrogen-doped chemical vapour deposition (CVD) overgrowth resulted in in situ formation of oriented NV ensembles, exclusively perpendicular to the {111}-planes.
A synergistic approach to synthesize nitrogen-doped nanobiochars with high adsorptive performance
Authors: Hoa Le Thi Thanh , Van Thanh Dang , Khai Nguyen Manh , Nguyen Manh Dung , Hao Pham Van , Nguyen Duc Dung , Tan Cher Ming , Mai Nguyen Thi
Published: August 2024

Developing versatile and energy-efficient processes to synthesize functional nanomaterials is of significant in response to economic concerns, enviroment, and technological challenges. This study presents a synergistic route for the facile, green, and low-cost synthesis of nitrogen-doped nanobiochars (NNBs) from an agriculture waste without any chemical supplements, promoting environmental sustainability. Specifically, rice husk is treated at 800 °C for 5 min in an enclosed reactor, followed by quenching in water and ultrasonic vibration in a water/ethanol mixed solvent. Surface morphology, specific surface area, crystalline structure, phase component, and chemical composition of the NNBs are characterized by electron microscopy, Brunauer–Emmett–Teller, x-ray diffraction, Raman, Fourier transform infrared spectroscopy, and x-ray photoelectron spectroscopy measurements, respectively. The results indicate that the NNBs possess porous structures with a high specific surface area of 303.4 m2/g and a large pore volume of 1.23 cm3 g−1. Moreover, the porous nature and functional groups, including C=NH (55.0%) and N-H (34.35%), in NNBs are harnessed for removing Ciprofloxacin, a common antibiotic pollutant in water, via hydrogen bonding and other interactions. As expected, NNBs demonstrate a high removal efficiency of 72.73% and and adsorption capacity of 7.27 mg g−1 at a pH of 5 and contact time of 150 min. These findings therefore opens new possibilities for scalable production of value-added materials from agriculture wastes for water treatment, enhancing public health and environmental protection.
Non-defective degeneracy in non-Hermitian bipartite system
Authors: Wu Chen-Huan
Published: August 2024

Starting from a Hermitian operator with two distinct eigenvalues, we construct a non-Hermitian bipartite system in Gaussian orthogonal ensemble according to random matrix theory, where we introduce the off-diagonal fluctuations through random eigenkets and realizing the bipartite configuration consisting of two D × D subsystems (with D being the Hilbert space dimension). As required by the global thermalization (chaos), one of the two subsystems is fully ranked, while the other is rank deficient. For the latter (rank-deficient) subsystem, there is a block with non-defective degeneracies that contains non-local symmetries, as well as the accumulation effect of the linear map in adjacent eigenvectors. The maximally mixed state formed by the eigenvectors of this special region does not exhibit thermal ensemble behavior (neither canonical or Gibbs), and displays similar characteristics to the corresponding reduced density, which can be verified through the Loschmidt echo and variance of the imaginary spectrum. This non-defective degeneracy region partially meets the Lemma in 10.1103/PhysRevLett.122.220603 and theorem in 10.1103/PhysRevLett.120.150603. The coexistence of strong entanglement and initial state fidelity in this region make it possible to achieve a maximally mixed density, which, however, does not correspond to a thermal canonical ensemble (with complete insensitivity to the environmental energy or temperature). Outside this region, the collection of eigenstates (reduced density) always exhibit restriction on the corresponding Hilbert space dimension (with, e.g., infinite number of bound states), and thus suppress the global thermalization. There are abundant physics for those densities in Hermitian and non-Hermitian bases, which we investigate separately in this work. For example, the disentangling effect originates from non-Hermitian skin effect where the coherence exists along the direction orthogonal to the entangled boundaries of the Loschmidt echo spectrum in the Hermitian basis, while it originates from the many-body localization with the coherence among echo boundaries in the non-Hermitian basis which is disorder-free.
Hypostomus plecostomus-inspired soft sucker to adsorb slippery tissues: a stabilizing post-valvular cavity and stiffness gradient materials provide excellent adsorption performance
Authors: Xiao Peng , Wang Ziwei , Zhou Kangpeng , Fan Xinwei , Zhang Yuhan , Sun Guangkai , Lianqing Zhu
Published: August 2024

The hard suckers commonly used in surgical operations often cause adsorption extrusion damage to the biological tissue. To tackle this problem, from the perspective of bionics, through in-depth observation and research on the special sucker adsorption process and adsorption mechanism of hypostomus plecostomus (HP), this paper proposes a bionic soft hypostomus plecostomus sucker (BSHPS) with a variable stiffness gradient structure with a good adsorption performance on soft moist irregular biological tissues. The BSHPS comprises a lip disc, a pre-valvular cavity, and a post-valvular cavity. Through the volume changes of the pre- and post-valvular cavities, a pressure difference is generated between the inside and outside of the sucker, enabling the lip disc to remain sealed. The experiments were carried out by an automatic tensile force measurement system equipped with a vacuum pump, and the results showed that in slippery environment, the adsorption performance of the BSHPS is improved by a maximum of 61.9% compared to that in dry environment. On a biological tissue surface, the adsorption force is as high as 13.7765 N. The most important advantage of the proposed BSHPS is that it can be firmly adsorbed the surface of soft moist irregular biological tissues, effectively slowing down or avoiding adsorption extrusion damage to the biological tissue. Therefore, the BSHPS is expected to have good application prospects in modern surgical medicine.
Energy models in service of aquifer specific groundwater irrigation expansion in India
Authors: Ray Sudatta , Benson Sally M
Published: August 2024

Pumping energy is a key component of the groundwater governance challenge, yet it is largely missing in the discourse on agricultural use of groundwater. A sub-category of the literature studying groundwater-energy nexus tends to focus on groundwater depletion hotspots where entrenched interests and long-standing histories restrict the range of feasible energy pricing options. Using an agent-based model, we estimate the expected impact of expanding groundwater irrigation under five different energy provision models in Odisha, an Indian state with among the lowest irrigation coverage, and, therefore, is free of path-dependent policies. We find that aquifer properties play a crucial role in mediating the groundwater-energy nexus. In this study region, on average, the maximum volume of water that can be pumped from a well of a specific depth in an alluvial aquifer is approximately 150 times the volume that can be pumped from a well in a hard-rock aquifer. Therefore, the risk of over-consumption and aquifer depletion is a far greater challenge in alluvial than hard-rock aquifers. Risks of groundwater consumption and depletion can be limited in hard-rock aquifers provided the number and depths of wells can be controlled. Capital subsidies for well construction could be an effective policy to increase irrigated areas as long as economic incentives for digging deeper are not distorted. Our results imply that solar pumps are a relatively safe option for hard-rock regions where deep drawdowns naturally limit the extent of over-extraction. Solar pumps are also estimated to be among the most economical for expanding irrigation. Using a novel data set comprising biophysical and socioeconomic data, we find hard-rock regions to have limited irrigation coverage, high availability of annually replenishable groundwater, and high concentrations of marginalized farmers. Therefore, groundwater irrigation expansion in hard-rock areas could have dual benefits of ensuring future food security and targeting poverty reduction.
Information scrambling and chaos induced by a Hermitian matrix
Authors: Gnutzmann Sven , Smilansky Uzy
Published: August 2024

Given an arbitrary V × V Hermitian matrix H, considered as a finite discrete quantum Hamiltonian, we use methods from graph and ergodic theories to construct a quantum Poincaré map at energy E and a corresponding stochastic classical Poincaré–Markov map at the same energy on an appropriate discrete phase space. This phase space

D

consists of the directed edges of a graph with V vertices that are in one-to-one correspondence with the non-vanishing off-diagonal elements of H. The correspondence between quantum Poincaré map and classical Poincaré–Markov map is an alternative to the standard quantum–classical correspondence based on a classical limit

ℏ
→
0

. Most importantly it can be constructed where no such limit exists. Using standard methods from ergodic theory we then proceed to derive an expression for the Lyapunov exponent

Λ
(
E
)

of the classical map. It measures the rate of loss of classical information in the dynamics and relates it to the separation of stochastic classical trajectories in the phase space. We suggest that loss of information in the underlying classical dynamics is an indicator for quantum information scrambling.
Existence and uniqueness of solutions of the Koopman–von Neumann equation on bounded domains
Authors: Stengl Marian , Gelß Patrick , Klus Stefan , Pokutta Sebastian
Published: August 2024

The Koopman–von Neumann equation describes the evolution of a complex-valued wavefunction corresponding to the probability distribution given by an associated classical Liouville equation. Typically, it is defined on the whole Euclidean space. The investigation of bounded domains, particularly in practical scenarios involving quantum-based simulations of dynamical systems, has received little attention so far. We consider the Koopman–von Neumann equation associated with an ordinary differential equation on a bounded domain whose trajectories are contained in the set’s closure. Our main results are the construction of a strongly continuous semigroup together with the existence and uniqueness of solutions of the associated initial value problem. To this end, a functional-analytic framework connected to Sobolev spaces is proposed and analyzed. Moreover, the connection of the Koopman–von Neumann framework to transport equations is highlighted.
Multi-parameterised surface texture characterisation for ultra-precision machined surfaces
Authors: Guo Pan , Xiong Zhiwen , Dong Zengwen , Zhang Shaojian , Piano Samanta , Liu Mingyu
Published: August 2024

In surface metrology, the multi-parameterised characterisation of surface texture measurement is beneficial not only for surface quality evaluation but also for manufacturing process inspection. To bridge this gap for ultra-precision machined surfaces, a white light interferometer was firstly employed for measuring surface texture generated by orthogonal ultra-precision machining experiments. Next, surface texture was filtered by the zero-order Gaussian regression filter to the limited scale bandwidth. Then, twenty-one surface texture parameters were calculated based on seventy-five S-L surfaces according to the ISO 25178-2. Finally, the outlier effect of surface measurement was investigated by the 95%–99% rule and the Spearman correlation coefficient matrix was proposed to determine their statistical correlation. The results revealed that most of the height parameters (Sp, Sv, Sz, Ssk, and Sku), several function and related parameters (Vmp, Vvv, Spk, and Svk), and the spatial parameter (Str) and hybrid parameter (Sdr) presented a strong sensitivity to the outlier effect. The height parameters (Sa, Sq, Sp, Sv, and Sz), the function and related parameters (Vmp, Vmc, Vvv, Vvc, Spk, Svk, and Sk), and the spatial parameters (Sdq and Sdr) showed a strong correlation to each other, while the miscellaneous parameter Std had a weak correlation to the other parameters. This study provides a systematic multi-parameterised surface texture characterisation for ultra-precision machined surfaces to promote the advancement of nanotechnology and nanometrology.
Synergistic effects of steel fiber and rubberized aggregates on concrete properties
Authors: Tefera Belay Bayu , Tarekegn Abrham Gebre , Ejigu Tsagazeab Yimer
Published: August 2024

The drive for more sustainable and environmentally friendly construction practices has resulted in revolutionary concrete production methods. One way is to include scrap rubber tires (contributing significantly to environmental pollution) into concrete mixtures to increase deformability. This study investigates the impact of surface-treated waste tire rubber (which partially replaces natural coarse aggregates with 5%, 10%, and 15% by weight) and industrial steel fiber (as reinforcement by including 0.5, 1, and 1.5% volume fractions) in concrete. Twelve concrete mixtures were prepared as test specimens. The replacement percentage was then determined using the compressive strength test results for additional surface treatment with three different alkaline solution (NaOH) concentrations (5%, 10%, and 15%) for 72 h. Thus, the hardened concrete properties were analyzed using compressive strength, flexural strength, and toughness; whereas the fresh qualities of equivalent concrete mixtures were evaluated using concrete slump. The findings revealed that, while partial replacement had a negative impact on the mechanical properties of the concrete, it was possible to produce rubberized concrete with better mechanical properties than conventional concrete when the partial replacement was less than 5%, treated with 10% alkaline solution, and reinforced with 1.5% steel fibers. The study’s findings illustrate the potential of these combinations for use in concrete pavement and slab applications.
Technology-enhanced environmental learning: a practical guide to educational areas for urban educators
Authors: Duda Ewa
Published: August 2024

Mobile applications are utilised by urban educators as a means to encourage environmentally friendly behaviours among city dwellers. To enhance their effectiveness, they should meet the needs of their potential users. This qualitative survey research studied urban population of the Tricity metropolitan area intended to identify the perspective of residents regarding the areas that require intervention. It focuses on the potential of mobile applications in promoting pro-environmental education, particularly in areas deemed sensitive by city residents and city users. The research framework is founded on action research. The data collection technique used a survey conducted through a research panel among 821 residents and users of the Tricity metropolitan area. The data was analysed by looking at the relevance of urban challenges and related areas of support. The results of the research were that 12 areas of city functioning perceived as needing improvement were identified and emotionally relevant among the 13 indicators analysed. In conclusion, 12 educational areas of city functioning were identified as relevant for the design of mobile applications related to environmental education. The results may also serve as a basis for developing instructional environmental education for urban educators to support local policies to address the climate crisis and encourage pro-environmental behaviour among urban residents.
Performance assessment of earth-abundant kesterite-based CZTSSe solar cell using graphene oxide as HTL and zinc oxysulfide as ETL
Authors: Yadav Shweta , Chauhan R K , Mishra Rajan
Published: August 2024

This research investigates the optimization of CZTSSe (copper zinc tin sulfide selenide) solar cells through the integration of graphene oxide (GO) in the role of HTL (hole transport layer) also zinc oxysulfide (Zn(O,S)) in the role of ETL (electron transport layer), replacing the conventional cadmium sulfide (CdS) buffer layer. CZTSSe, characterized by an impactful direct energy bandgap (1–1.5 eV) also a high absorption coefficient (>104 cm−1), exhibits prospects for efficient light absorption in the visible range. The study employs simulation characterization to comprehensively analyze the impact of the GO hole transparent layer and Zn (O,S) buffer layer on the optical and electrical attributes of the CZTSSe photovoltaic(PV) cell. Key parameters, such as power conversion efficiency (PCE), short-circuit current (JSC), fill factor (FF), and open-circuit voltage (VOC), are meticulously examined to substantiate the performance of the devices. These parameters include the energy bandgap, variations in thickness, doping concentration, defect density, parasitic resistance, temperature, and generation and recombination processes. The objective is to understand how these factors influence solar cell performances and to enhance light absorption, elevate charge mobility, and minimize carrier recombination losses. The culmination of these efforts results in the CZTSSe solar module achieving its maximum PCE of 28.23% when incorporating a Zn(O,S) ETL along with a GO hole transport layer and ZnO:Al as a window layer.
Yellow and oxidation-resistant derivatives of a monomeric superfolder GFP
Authors: Valbuena Fernando M. , Krahn Adam H. , Tokamov Sherzod A. , Greene Annie C. , Fehon Richard G. , Glick Benjamin S.
Published: August 2024

Fluorescent proteins (FPs) are essential tools in biology. The utility of FPs depends on their brightness, photostability, efficient folding, monomeric state, and compatibility with different cellular environments. Despite the proliferation of available FPs, derivatives of the originally identified Aequorea victoria green fluorescent protein often show superior behavior as fusion tags. We recently generated msGFP2, an optimized monomeric superfolder variant of A. victoria GFP. Here, we describe two derivatives of msGFP2. The monomeric variant msYFP2 is a yellow superfolder FP with high photostability. The monomeric variant moxGFP2 lacks cysteines but retains significant folding stability, so it works well in the lumen of the secretory pathway. These new FPs are useful for common imaging applications.
Long-range white matter fibres and post-stroke verbal and non-verbal cognition
Authors: Roth Rebecca W , Schwen Blackett Deena , Gleichgerrcht Ezequiel , Wilmskoetter Janina , Rorden Chris , Newman-Norlund Roger , Sen Souvik , Fridriksson Julius , Busby Natalie , Bonilha Leonardo
Published: August 2024

Among stroke survivors, linguistic and non-linguistic impairments exhibit substantial inter-individual variability. Stroke lesion volume and location do not sufficiently explain outcomes, and the neural mechanisms underlying the severity of aphasia or non-verbal cognitive deficits remain inadequately understood. Converging evidence supports the idea that white matter is particularly susceptible to ischaemic injury, and long-range fibres are commonly associated with verbal and non-verbal function. Here, we investigated the relationship among post-stroke aphasia severity, cognition, and white matter integrity. Eighty-seven individuals in the chronic stage of stroke underwent diffusion MRI and behavioural testing, including language and cognitive measures. We used whole-brain structural connectomes from each participant to calculate the ratio of long-range fibres to short-range fibres. We found that a higher proportion of long-range fibres was associated with lower aphasia severity, more accurate picture naming, and increased performance on non-verbal semantic memory/processing and non-verbal reasoning while controlling for lesion volume, key damage areas, age, and years post stroke. Our findings corroborate the hypothesis that, after accounting for age and lesion anatomy, inter-individual differences in post-stroke aphasia severity, verbal, and non-verbal cognitive outcomes are related to the preservation of long-range white matter fibres beyond the lesion.
Dissociable effects of mild COVID-19 on short- and long-term memories
Authors: Atkinson Lauren Z , Thom Jude L , Nobre Anna Christina , Zokaei Nahid
Published: August 2024

Recent studies have highlighted the presence of cognitive deficits following COVID-19 that persist beyond acute infection, regardless of the initial disease severity. Impairments in short- and long-term memory are among the core deficits reported by patients and observed in objective tests of memory performance. We aimed to extend previous studies by examining performance in a task that allows us to directly compare and contrast memories at different timescales. More specifically, we assessed both short- and long-term memories for contextual–spatial associations encoded during a common session and probed at different durations using an equivalent task in non-hospitalized individuals recovering from mild COVID-19 compared to healthy controls. The approach equated all aspects of memory materials and response demands, isolating performance changes resulting only from memory timescales and thus allowing us to quantify the impact of COVID-19 on cognition. In addition to providing measures of accuracy and response times, the task also provided a sensitive continuous readout of the precision of memory representations, specifically by examining the resolution with which spatial locations were retained in memory. The results demonstrated selective impairment of long-term memory performance in individuals recovering from mild COVID-19 infection. Short-term memory performance remained comparable to healthy controls. Specifically, poor precision of long-term memory representations was demonstrated, which improved with days since diagnosis. No such relationship was observed for short-term memory performance. Our findings reveal a specific impairment to the precision of spatial–contextual long-term memory representations in individuals recovering from mild COVID-19 and demonstrate evidence of recovery in long-term memory over time. Further, the experimental design provides a carefully controlled and sensitive framework to assess memory across different durations with the potential to provide more detailed phenotyping of memory deficits associated with COVID-19 in general.
Molecular profiling of a cohort with epidermolysis bullosa in India: a single centre experience
Authors: Kumar Anoop , Jamwal Manu , Gupta Smriti , Sharma Ritika , Singh Namrata , Kaushal Laveena , Kumar Sahil , Kumar Vinod , Behera Biswanath , De Dipankar , Handa Sanjeev , Nahar Uma , Chatterjee Debajyoti , Das Reena , Mahajan Rahul
Published: August 2024

Background

Epidermolysis bullosa (EB) encompasses rare hereditary skin conditions marked by skin fragility, nail dystrophy and minor trauma-induced skin blisters.

Objectives

To identify genetic variants in patients with EB in India and to examine the relationship between genotypic and phenotypic manifestations.

Methods

Patients with EB seen consecutively over a period of 5 years at an outpatient department of dermatology (Postgraduate Institute of Medical Education and Research, Chandigarh, India) were included in the study. Baseline demographic data, birth history, family history, skin manifestations at birth, medical history, current cutaneous manifestations and the evolution of the disease were assessed and recorded. Genetic variants were identified using targeted gene panel sequencing for 23 EB-related genes and a genetic–phenotype analysis was performed.

Results

Our study included 65 patients with EB. Among these 65 patients with EB, 38 had dystrophic EB (DEB, 58%), 12 had junctional EB (JEB, 18%), 12 had EB simplex (EBS, 18%) and 3 had Kindler EB (KEB, 5%). Dominant and recessive forms of dystrophic EB accounted for 17% (n = 11) and 42% (n = 27), respectively, of the 65 individuals with EB. We identified 75 genetic variants, 59% (n = 44) newly discovered and 41% (n = 31) previously reported. Compound heterozygous variants were more frequent (56%; 15/27) than homozygous ones (44%; 12/27) in individuals with recessive DEB. Patients with JEB harboured LAMB3 mutations more frequently, whereas patients with EBS harboured KRT5 and KRT14 missense heterozygous mutations. Patients with KEB had homozygous mutations in FERTM1.

Conclusions

Our study has unveiled several novel genetic variants and severe phenotypes associated with nonsense genetic variants. These findings offer valuable insights for future clinical assessments and tailored management strategies.
Patient and caregiver experience of accessing information on hidradenitis suppurativa through social media
Authors: Wolinska Anna , McGrath Barry M , Tobin Anne-Marie
Published: August 2024

This study demonstrates that individuals with hidradenitis suppurativa actively seek information regarding the condition online. It also highlights the valuable contribution of patient support groups and raises the question of whether there is a role for dermatologists to contribute through such channels of communication to support the dissemination of verified information.
Assessing the Impact of Pneumococcal Conjugate Vaccine Immunization Schedule Change From 3+0 to 2+1 in Australian Children: A Retrospective Observational Study
Authors: Jayasinghe Sanjay , Williams Phoebe C M , Macartney Kristine K , Crawford Nigel W , Blyth Christopher C
Published: August 2024

Background

In mid-2018, the Australian childhood 13-valent pneumococcal conjugate vaccine schedule changed from 3+0 to 2+1, moving the third dose to 12 months of age, to address increasing breakthrough cases of invasive pneumococcal disease (IPD), predominantly in children aged >12 months. This study assessed the impact of this change using national IPD surveillance data.

Methods

Pre- and postschedule change 3-dose 13-valent pneumococcal conjugate vaccine breakthrough cases were compared by age group, serotype, and clinical syndrome. Annual rates of breakthrough cases were calculated (per 100 000) using respective birth cohort sizes and 3-dose vaccine coverage. Using time-series modelling, observed IPD rates in children aged <12 years were compared to that expected if the 3+0 schedule were continued.

Findings

Over 2012–2022, rate of 3-dose breakthrough cases in children aged >12 months was 2.8 per 100 000 (n = 557; 11 birth cohorts). Serotype 3 replaced 19A as predominant breakthrough serotype (respectively, 24% and 65% in 2013 to 60% and 20% in 2022) followed by 19F. In breakthrough cases, the most frequent clinical phenotype was bacteremic pneumonia (69%), with meningitis accounting for 3%–4%. In cohorts eligible for 2+1 versus 3+0 schedules, rate of breakthrough cases was lower for all vaccine serotypes, except type 3 (incidence rate ratio, 0.50 [95% confidence interval, .28–.84] and 1.12 [0.71–1.76], respectively). Observed compared to expected IPD was 51.7% lower (95% confidence interval, −60.9 to −40.7%) for vaccine serotypes, but the change for nonvaccine types was not significant 12% (−9.6 to 39.7).

Interpretations

The 2+1 schedule is likely superior to 3+0 for overall IPD control, a finding that may be worth consideration for other countries considering or using 3+0 PCV schedules.