bluuebunny/crossref_metadata_2025 huggingface dataset:
Self-consistent approach to the dynamics of excitation energy transfer in multichromophoric systems
Authors: Janković Veljko , Mančal Tomáš
Published: November 2024

Computationally tractable and reliable, albeit approximate, methods for studying exciton transport in molecular aggregates immersed in structured bosonic environments have been actively developed. Going beyond the lowest-order (Born) approximation for the memory kernel of the quantum master equation typically results in complicated and possibly divergent expressions. Starting from the memory kernel in the Born approximation, and recognizing the quantum master equation as the Dyson equation of Green’s functions theory, we formulate the self-consistent Born approximation to resum the memory-kernel perturbation series in powers of the exciton–environment interaction. Our formulation is in the Liouville space and frequency domain and handles arbitrary exciton–environment spectral densities. In a molecular dimer coupled to an overdamped oscillator environment, we conclude that the self-consistent cycle significantly improves the Born-approximation energy-transfer dynamics. The dynamics in the self-consistent Born approximation agree well with the solutions of hierarchical equations of motion over a wide range of parameters, including the most challenging regimes of strong exciton–environment interactions, slow environments, and low temperatures. This is rationalized by the analytical considerations of coherence-dephasing dynamics in the pure-dephasing model. We find that the self-consistent Born approximation is good (poor) at describing energy transfer modulated by an underdamped vibration resonant (off-resonant) with the exciton energy gap. Nevertheless, it reasonably describes exciton dynamics in the seven-site model of the Fenna–Matthews–Olson complex in a realistic environment comprising both an overdamped continuum and underdamped vibrations.
Hot phonon effect in mid-infrared HgTe/CdHgTe quantum wells evaluated by quasi-steady-state photoluminescence
Authors: Kudryavtsev K. E. , Rumyantsev V. V. , Dubinov A. A. , Aleshkin V. Y. , Zholudev M. S. , Mikhailov N. N. , Dvoretsky S. A. , Gavrilenko V. I. , Morozov S. V.
Published: November 2024

Room-temperature photoluminescence (PL) spectra of intensely pumped HgTe/CdHgTe quantum well (QW) heterostructures emitting at around 5 μm wavelength have been investigated. Based on the model description of the PL spectra using a free-electron recombination band approach, effective electronic temperatures were determined depending on the excitation density. Within the quasi-steady-state approximation, we establish the balance between pump-induced heating of the electron gas in the QWs and phonon-mediated dissipation of this excess energy and deduce hot-phonon lifetime of ∼0.47 ps. Maximum operating temperatures for optically pumped HgTe/CdHgTe QW laser heterostructures emitting at around 5 μm are estimated depending on the excitation wavelength, and lasing at Peltier temperatures appears feasible for the pump wavelength of about 3 μm. Thus, the entire 3∼5 μm atmospheric transparency window can be potentially covered by thermoelectrically cooled HgCdTe-based laser sources.
Self-trapped exciton-phonon resonance enhanced nonlinear susceptibility in 2D KNbO2
Authors: Zhou Fei , Yang Zhiyuan , Huang Jingtao , Zheng Xueping , Wei Xianhua , Dai Bo
Published: November 2024

Strong second harmonic generation (SHG) was observed when the two-photon energy matches to the self-trapped exciton resonance states in the lattice inversion symmetric system of two-dimensional (2D) KNbO2 crystals. It is ascribed to the symmetry broken induced by the bending distortion of O−Nb−O in individual octahedrons (low frequency T2g modes) that coupling to the two-photon frequency. The quantum confinement SHG response with more than one orders of enhancement is obtained due to the phonon-exciton-photon interaction with dimension reduction. In addition, the exciton-phonon interaction couples SHG photons to a non-equilibrium energy with a Stokes or anti-Stokes energy splitting of ∼18–21 meV, which is corresponding to the Raman shift of T2g modes.
Strain-induced valley polarization, topological states, and piezomagnetism in two-dimensional altermagnetic V2Te2O, V2STeO, V2SSeO, and V2S2O
Authors: Li Jin-Yang , Fan An-Dong , Wang Yong-Kun , Zhang Ying , Li Si
Published: November 2024

Altermagnets (AM) are a recently discovered third class of collinear magnets and have been attracting significant interest in the field of condensed matter physics. Here, based on first-principles calculations and theoretical analysis, we propose four two-dimensional (2D) magnetic materials—monolayers V2Te2O, V2STeO, V2SSeO, and V2S2O—as candidates for altermagnetic materials. We show that these materials are semiconductors with spin-splitting in their nonrelativistic band structures. Furthermore, in the band structure, there is a pair of Dirac-type valleys located at the time-reversal invariant momenta (TRIM) X and Y points. These two valleys are connected by crystal symmetry instead of time-reversal symmetry. We investigate the strain effect on the band structure and find that uniaxial strain can induce valley polarization, topological states in these monolayer materials. Moreover, piezomagnetism can be realized upon finite doping. Our result reveals interesting valley physics in monolayers V2Te2O, V2STeO, V2SSeO, and V2S2O, suggesting their great potential for valleytronics, spintronics, and multifunctional nanoelectronics applications.
Reducing disorder in Ge quantum wells by using thick SiGe barriers
Authors: Costa Davide , Stehouwer Lucas E. A. , Huang Yi , Martí-Sánchez Sara , Degli Esposti Davide , Arbiol Jordi , Scappucci Giordano
Published: November 2024

We investigate the disorder properties of two-dimensional hole gases in Ge/SiGe heterostructures grown on Ge wafers, using thick SiGe barriers to mitigate the influence of the semiconductor–dielectric interface. Across several heterostructure field effect transistors, we measure an average maximum mobility of (4.4±0.2)×106 cm2/Vs at a saturation density of (1.72±0.03)×1011 cm−2, corresponding to a long mean free path of (30±1)μm. The highest measured mobility is 4.68×106 cm2/Vs. We identify uniform background impurities and interface roughness as the dominant scattering mechanisms limiting mobility in a representative device, and we evaluate a percolation-induced critical density of (4.5±0.1)×109 cm−2. This low-disorder heterostructure, according to simulations, may support the electrostatic confinement of holes in gate-defined quantum dots.
PBLD enhances antiviral innate immunity by promoting the p53–USP4–MAVS signaling axis
Authors: Chu Fengyun , Hou Peili , Zhu Hongchao , Gao Yan , Wang Xiaomeng , He Wenqi , Ren Juan , Li Min , Liu Yu , Chang He Daniel , Wang Hongmei , Gao Yuwei , He Hongbin
Published: November 2024

Phenazine biosynthesis-like domain-containing protein (PBLD) has been reported to be involved in the development of many cancers. However, whether PBLD regulates innate immune responses and viral replication is unclear. In this study, although it was found that the activity of PBLD extends to other PRRs, we focused on the RLR pathway activated via the p53–USP4–MAVS axis in response to virus infections. We found that PBLD deubiquitinates and stabilizes MAVS through ubiquitin-specific protease 4 (USP4) to promote antiviral innate immunity. Mechanistically, PBLD activates the transcription of USP4 via the upregulation of p53. USP4, which is a MAVS-interacting protein, substantially stabilizes the MAVS protein by deconjugating K48-linked ubiquitination chains from the MAVS protein at Lys461 during RNA virus infection. Most intriguingly, RNA virus-infected primary macrophages (peritoneal macrophages, PMs, and bone marrow–derived macrophages, BMDMs) and internal organ cells (lung and liver) from PBLD-deficient mice suppress the IFN-I response and promote viral replication. Notably, PBLD-deficient mice are more susceptible to RNA virus infection than their wild-type littermates. Our findings highlight a unique function of PBLD in antiviral innate immunity through the p53–USP4–MAVS signaling, providing a preliminary basis for research on PBLD as a target molecule for treating RNA virus infection.
Staggered immunization with mRNA vaccines encoding SARS-CoV-2 polymerase or spike antigens broadens the T cell epitope repertoire
Authors: Abt Evan R. , Lam Alex K. , Noguchi Miyako , Rashid Khalid , McLaughlin Jami , Teng Pu-Lin , Tran Wendy , Cheng Donghui , Nesterenko Pavlo A. , Mao Zhiyuan , Creech Amanda L. , Burton Sojo Giselle , Jeyachandran Arjit Vijey , Tam Ying K. , Henley Jill E. , Comai Lucio , Pardi Norbert , Arumugaswami Vaithilingaraja , Witte Owen N. , Radu Caius G. , Wu Ting-Ting
Published: November 2024

Combining a T cell-targeting mRNA vaccine encoding the conserved SARS-CoV-2 RNA-dependent RNA polymerase, RdRp, with a Spike-encoding mRNA vaccine may offer an additional pathway toward COVID-19 protection. Here, we show that a nucleoside-modified RdRp mRNA vaccine raises robust and durable CD8+ T cell responses in mice. Immunization drives a CD8+ T cell response enriched toward a specific RdRp epitope. Unexpectedly, coadministration of mRNA vaccines encoding RdRp or the Spike Receptor Binding Domain (RBD) dampens RBD-specific immune responses. Contralateral administration reduces the suppression of RBD-specific T cell responses while type I interferon signaling blockade restores RBD-specific antibodies. A staggered immunization strategy maintains both RBD vaccine-mediated antibody and T cell responses as well as protection against lethal SARS-CoV-2 challenge in human ACE2 transgenic mice. In HLA-A2.1 transgenic mice, the RdRp vaccine elicits CD8+ T cell responses against HLA-A*02:01-restricted epitopes recognized by human donor T cells. These results highlight RdRp as a candidate antigen for COVID-19 vaccines. The findings also offer insights into crafting effective multivalent mRNA vaccines to broaden CD8+ T cell responses against SARS-CoV-2 and potentially other viruses with pandemic potential.
Early disruption of the CREB pathway drives dendritic morphological alterations in FTD/ALS cortical neurons
Authors: Jean Gregoire Michelle , Sirtori Riccardo , Donatelli Liviana , Morgan Potts Emily , Collins Alicia , Zamor Danielo , Katenka Natallia , Fallini Claudia
Published: November 2024

Synaptic loss and dendritic degeneration are common pathologies in several neurodegenerative diseases characterized by progressive cognitive and/or motor decline, such as Alzheimer’s disease (AD) and frontotemporal dementia/amyotrophic lateral sclerosis (FTD/ALS). An essential regulator of neuronal health, the cAMP-dependent transcription factor CREB positively regulates synaptic growth, learning, and memory. Phosphorylation of CREB by protein kinase A (PKA) and other cellular kinases promotes neuronal survival and maturation via transcriptional activation of a wide range of downstream target genes. CREB pathway dysfunction has been strongly implicated in AD pathogenesis, and recent data suggest that impaired CREB activation may contribute to disease phenotypes in FTD/ALS as well. However, the mechanisms behind reduced CREB activity in FTD/ALS pathology are not clear. In this study, we found that cortical-like neurons derived from iPSC lines carrying the hexanucleotide repeat expansion in the C9ORF72 gene, a common genetic cause of FTD/ALS, displayed a diminished activation of CREB, resulting in decreased dendritic and synaptic health. Importantly, we determined such impairments to be mechanistically linked to an imbalance in the ratio of regulatory and catalytic subunits of the CREB activator PKA and to be conserved in C9-ALS patient’s postmortem tissue. Modulation of cAMP upstream of this impairment allowed for a rescue of CREB activity and an amelioration of dendritic morphology and synaptic protein levels. Our data elucidate the mechanism behind early CREB pathway dysfunction and discern a feasible therapeutic target for the treatment of FTD/ALS and possibly other neurodegenerative diseases.
TMPRSS2-mediated SARS-CoV-2 uptake boosts innate immune activation, enhances cytopathology, and drives convergent virus evolution
Authors: Qu Bingqian , Miskey Csaba , Gömer André , Kleinert Robin D. V. , Ibanez Sara Calvo , Eberle Regina , Ebenig Aileen , Postmus Dylan , Nocke Maximilian K. , Herrmann Maike , Itotia Tabitha K. , Herrmann Simon T. , Heinen Natalie , Höck Sebastian , Hastert Florian D. , von Rhein Christine , Schürmann Christoph , Li Xue , van Zandbergen Ger , Widera Marek , Ciesek Sandra , Schnierle Barbara S. , Tarr Alexander W. , Steinmann Eike , Goffinet Christine , Pfaender Stephanie , Locker Jacomina Krijnse , Mühlebach Michael D. , Todt Daniel , Brown Richard J. P.
Published: November 2024

The accessory protease transmembrane protease serine 2 (TMPRSS2) enhances severe
acute respiratory syndrome coronavirus 2 (SARS-CoV-2) uptake into
ACE2-expressing cells, although how increased entry impacts downstream viral and
host processes remains unclear. To investigate this in more detail, we performed
infection assays in engineered cells promoting ACE2-mediated entry with and
without TMPRSS2 coexpression. Electron microscopy and inhibitor experiments
indicated TMPRSS2-mediated cell entry was associated with increased virion
internalization into endosomes, and partially dependent upon clathrin-mediated
endocytosis. TMPRSS2 increased panvariant uptake efficiency and enhanced early
rates of virus replication, transcription, and secretion, with variant-specific
profiles observed. On the host side, transcriptional profiling confirmed the
magnitude of infection-induced antiviral and proinflammatory responses were
linked to uptake efficiency, with TMPRSS2-assisted entry boosting early
antiviral responses. In addition, TMPRSS2-enhanced infections increased rates of
cytopathology, apoptosis, and necrosis and modulated virus secretion kinetics in
a variant-specific manner. On the virus side, convergent signatures of
cell-uptake-dependent innate immune induction were recorded in viral genomes,
manifesting as switches in dominant coupled Nsp3 residues whose frequencies were
correlated to the magnitude of the cellular response to infection.
Experimentally, we demonstrated that selected Nsp3 mutations conferred enhanced
interferon antagonism. More broadly, we show that TMPRSS2 orthologues from
evolutionarily diverse mammals facilitate panvariant enhancement of cell uptake.
In summary, our study uncovers previously unreported associations, linking cell
entry efficiency to innate immune activation kinetics, cell death rates, virus
secretion dynamics, and convergent selection of viral mutations. These data
expand our understanding of TMPRSS2’s role in the SARS-CoV-2 life cycle
and confirm its broader significance in zoonotic reservoirs and animal models.
Flexible bioelectronic systems with large-scale temperature sensor arrays for monitoring and treatments of localized wound inflammation
Authors: Liu Junhan , Li Zhongzheng , Sun Mubai , Zhou Lianjie , Wu Xiaojun , Lu Yifei , Shao Yuting , Liu Chang , Huang Ningge , Hu Bofan , Wu Zhongyuan , You Chunyu , Li Lizhu , Wang Ming , Tao Ling , Di Zengfeng , Sheng Xing , Mei Yongfeng , Song Enming
Published: November 2024

Continuous monitoring and closed-loop therapy of soft wound tissues is of particular interest in biomedical research and clinical practices. An important focus is on the development of implantable bioelectronics that can measure time-dependent temperature distribution related to localized inflammation over large areas of wound and offer in situ treatment. Existing approaches such as thermometers/thermocouples provide limited spatial resolution, inapplicable to a wearable/implantable format. Here, we report a conformal, scalable device package that integrates a flexible amorphous silicon–based temperature sensor array and drug-loaded hydrogel for the healing process. This system can enable the spatial temperature mapping at submillimeter resolution and high sensitivity of 0.1 °C, for dynamically localizing the inflammation regions associated with temperature change, automatically followed with heat-triggered drug delivery from hydrogel triggered by wearable infrared light-emitting-diodes. We establish the operational principles experimentally and computationally and evaluate system functionalities with a wide range of targets including live animal models and human subjects. As an example of medical utility, this system can yield closed-loop monitoring/treatments by tracking of temperature distribution over wound areas of live rats, in designs that can be integrated with automated wireless control. These findings create broad utilities of these platforms for clinical diagnosis and advanced therapy for wound healthcare.
Synthesizing ordered polar patterns in nonpolar SrTiO
3
nanofilms via wrinkle-induced flexoelectricity
Authors: Shang Hongxing , Sheng Tang , Dong Huiting , Wu Yihan , Ma Qianqian , Zhang Xin , Lv Lingtong , Cao Hongyu , Deng Feng , Liang Xu , Hu Shuling , Shen Shengping
Published: November 2024

Ordered polar structures in oxide nanofilms play a pivotal role in the development of nanoelectronic applications. Hitherto, ordered polar structures have been restricted to a limited number of ferroelectric materials, and there is no effective scheme to induce and manipulate ordered polar patterns in centrosymmetric nonpolar nanofilms due to the absence of spontaneous symmetry breaking. Here, we circumvent these limitations by utilizing the wrinkle-induced strain gradient modulation associated with flexoelectricity as a general means of inducing and manipulating ordered polar patterns in nonpolar nanofilms. Leveraging the surface instability caused by strain mismatch between oxide nanofilms and pre-strained compliant substrate, we successfully fabricate striped SrTiO
3
wrinkles, where well-ordered strain gradients and corresponding periodic polar patterns are readily achieved. Through in-situ piezoresponse force microscopy experiments, we show that the generated polar patterns can be manipulated by varying strain boundaries. Furthermore, the atomistic resolution images and first-principles calculations reveal that such wrinkle-induced ordered polar patterns primarily emerge from the flexoelectric coupling between the local polarization and strain gradients. These findings provide implications for manipulating polar structures by strain gradient and flexoelectric engineering, which in turn enable the realization of nontrivial polar structures in a broader range of materials.
Learning medical terminology in an ESP medical course
Authors: Gaffas Zainab M.
Published: November 2024

This quasi-experimental study investigated the efficacy of two distinct approaches for vocabulary learning, namely
vocabulary notebooks and word lists, specifically in the context of learning medical terms. Sixty first-year undergraduate EFL
students enrolled in an English for Specific Purposes (ESP) medical course were recruited and divided equally into three groups:
one group received guidance on using and maintaining vocabulary notebooks to learn 50 target terms, one group was instructed in
the use of word lists to study the same 50 target words, and the control group did not undergo any intervention. The results
indicate that both treatment approaches yielded significant advancements in vocabulary learning from pretests to posttests.
However, the vocabulary notebook group demonstrated significantly superior performance in long-term effectiveness compared with
the word list group. The findings imply that both approaches should be incorporated in a medical ESP curriculum.
Asymmetric multichannel spin-dependent splitting based on a single-layer dielectric metasurface
Authors: Ke Yougang , Tian Jibo , Zhang Rui , Zeng Kang , Zeng Linzhou , Min Li , Zhou Xinxing
Published: November 2024

Realization of multichannel spin-dependent splitting that allows for wavefront shaping is urgently required in applications based on the photonic spin Hall effect (PSHE). In this paper, we implement the multichannel spin-dependent splitting that supports preset laser modes by using a single-layer dielectric metasurface. This metasurface introduces a dynamic phase and a Pancharatnam–Berry phase simultaneously, which allows for encoding two independent phase distributions to the two orthogonal circular polarizations. We demonstrate that in the proposed multichannel spin-dependent splitting, the intensities of the beams, the locations of the spots, and the number of the spin-dependent channels, can be asymmetric. Consistent results given by the Fresnel diffraction integral formula and the finite difference time domain method reveal the good performance of the implemented multichannel spin-dependent splitting. This paper offers a simple and convenient approach to manipulate spin photons, which may serve the PSHE-based applications in optical information processing, precision metrology, and edge imaging.
Generalized representative structures for atomistic systems
Authors: Goff James M , Mullen Coreen , Yang Shizhong , Starovoytov Oleg N , Wood Mitchell A
Published: November 2024

A new method is presented to generate atomic structures that reproduce the essential characteristics of arbitrary material systems, phases, or ensembles. Previous methods allow one to reproduce the essential characteristics (e.g. the chemical disorder) of a large random alloy within a small crystal structure. The ability to generate small representations of random alloys, along with the restriction to crystal systems, results from using the fixed-lattice cluster correlations to describe structural characteristics. A more general description of the structural characteristics of atomic systems is obtained using complete sets of atomic environment descriptors. These are used within for generating representative atomic structures without restriction to fixed lattices. A general data-driven approach is provided here utilizing the atomic cluster expansion (ACE) basis. The N-body ACE descriptors are a complete set of atomic environment descriptors that span both chemical and spatial degrees of freedom and are used within for describing atomic structures. The generalized representative structure (GRS) method presented within generates small atomic structures that reproduce ACE descriptor distributions corresponding to arbitrary structural and chemical complexity. It is shown that systematically improvable representations of crystalline systems on fixed parent lattices, amorphous materials, liquids, and ensembles of atomic structures may be produced efficiently through optimization algorithms. With the GRS method, we highlight reduced representations of atomistic machine-learning training datasets that contain similar amounts of information and small 40–72 atom representations of liquid phases. The ability to use GRS methodology as a driver for informed novel structure generation is also demonstrated. The advantages over other data-driven methods and state-of-the-art methods restricted to high-symmetry systems are highlighted.
Design and verification of a novel self-powered sensing system for intelligent bearings
Authors: Li Zhen , Yuan Zekun , Wang Dandan , Mao Yuze , Wang Liqin , Shu Kun , Zuo Yichao , Ma Xinxin
Published: November 2024

This paper presents the development of a novel self-powered sensing system for roller bearing NU208. The system was designed based on an analysis of the bearing’s structural parameters and service condition monitoring signals. Through the selection of appropriate hardware and the design of a suitable circuitry, the power supply circuit, the main controller circuit, the parameter monitoring circuit, and the wireless data transmission circuit have been constructed. Additionally, the wireless data receiving module program and the upper computer software interface program have been developed. The upper computer software interface enables the real-time display of bearing vibration, cage speed, inner ring speed, and temperature signals. The self-powered sensing system is integrated and encapsulated within the roller bearing NU208, and its performance is verified on a small bearing test bench. The test results are precise and the data accuracy and output frequency meet the anticipated requirements. The self-powered sensing system developed in this paper fulfills the criteria for intelligent bearings that do not require an external power source or monitoring signals via cable transmission. It has significant scientific value and engineering significance for the study of intelligent bearings’ autonomous decision-making and self-regulation.
Study of spot distance on resistance spot welding quality: a 1DCNN-BiLSTM-Attention-based online inspection method
Authors: Deng Haofeng , Gao Xiangdong , Lv Zigui , Tan Wenzheng , Gao Pengyu
Published: November 2024

Resistance spot welding (RSW) is widely employed in the automotive and home appliance industries due to its high efficiency, low cost, and suitability for automation. However, traditional quality detection methods rely on destructive testing, leading to inefficiencies and resource wastage. This paper presents a novel quality inspection model for RSW that utilizes a one-dimensional convolutional neural network, bidirectional long short-term memory network, and attention mechanism (1DCNN-BiLSTM-Attention) to address the challenges of extracting temporal data under varying spot distances. The model integrates a residual linking mechanism and Kolmogorov–Arnold networks to enhance feature extraction and performance. Experimental results reveal that the model demonstrates strong predictive capabilities across different spot distances, with particularly notable performance at 10 mm spacing, achieving a mean absolute error of 0.0632, a root mean square error of 0.0603, and an R
2 value of 0.7513. These findings underscore the model’s ability to provide high-precision predictions, even under conditions influenced by significant shunt effects.
On the role of cross-slip and collinear annihilation in dynamic recovery
Authors: Madec Ronan , Devincre Benoit , Kubin Ladislas
Published: November 2024

Dynamic recovery (DR) during single crystal stage III is believed to result from cross-slip or at least be triggered by this dislocation mechanism. However, the precise causal chain of events that induces a return to a low hardening value, similar to stage I, after the strong hardening of stage II, remains unclear. Unlike strain hardening, which has been the subject of numerous successful 3D Dislocation Dynamics simulations (3D-DD), DR has been sparsely studied. This is primarily because it requires achieving large strains to reach stage III, which is difficult to obtain in a sufficiently large volume to be statistically meaningful for dislocation modeling, especially under quasi-static loading. However, it is possible to conduct 3D-DD simulations with high dislocation density to approximate conditions close to stage III and attempt to identify the potential causes of recovery. This is what we aimed to do in the present study, with simulations at different dislocation densities and by testing specific dislocation mechanisms separately to determine their exact contributions. Our results, while not definitive, provide insight into the origin of DR. Firstly, we demonstrate that a previously neglected athermal mechanism, i.e. collinear annihilation, plays an important role in DR, being the only forest mechanism that induces virtually no storage. Secondly, we show that plastic instabilities favoring a reduction in the number of active systems are a highly effective way of reducing dislocation storage. Lastly, cross-slip is found to reduce dislocation storage under very specific slip conditions, suggesting that these conditions should exist during Stage III.
On time-periodic solutions to an interaction problem between compressible viscous fluids and viscoelastic beams
Authors: Kreml Ondřej , Mácha Václav , Nečasová Šárka , Trifunović Srđan
Published: November 2024

In this paper, we study a nonlinear fluid-structure interaction problem between a ‘square-root’ viscoelastic beam and a compressible viscous fluid. The beam is immersed in the fluid which fills a two-dimensional rectangular domain with periodic boundary conditions in both directions, while both the beam and the fluid are under the effect of time-periodic forces. By using a decoupling approach, at least one time-periodic weak solution to this problem is constructed which has a bounded energy and a fixed prescribed mass. The lack of a priori energy bounds is overcome by a series of estimates based on a careful choice of parameters. The most challenging one is the pressure estimate, which is obtained by utilizing the specific periodic geometry and the Bogovskiǐ operator on a fixed domain that has a uniform constant. With uniform estimates and improved regularity of the beam as in (Muha and Schwarzacher 2023 Ann. Inst. Henri Poin. Anal. Non Lineaire
39 1369–412), the time-periodic solution is constructed by a series of limit procedures, following the finite-dimensional time-space construction from (Feireisl et al 2012 Arch. Rational Mech. Anal.
204 74586).
Utilizing smartphone proximity sensor to analyse accelerated motion of object in an inclined plane and determine the acceleration and kinetic friction coefficient
Authors: Susanti Eka , Nawiyah Nawiyah , Janna Fadhillah , Angraini Reza , Zahra Nabila , Kariyma Rizqa , Hidayat Rahmat
Published: November 2024

In this work, we launched smartphones with a moving object to analyse the motion on an inclined plane. The data of time versus distance was acquired by utilizing a smartphone proximity sensor to record time intervals between detection objects whose distance had been set beforehand. The plot of time versus distance was used to analyze the characteristics of accelerated motion. Meanwhile, time squared versus distance was used to determine acceleration. The inclination angle was varied to observe the effect on the motion characteristic and acceleration value. Furthermore, kinetic friction coefficient existing along the object’s motion was also calculated.
Exact solutions and bifurcations of the new (3+1)-dimensional generalized Kadomstev-Petviashvili equation
Authors: Meng Hui , Zheng Zhen , Zhang Jing , Wang Zenggui
Published: November 2024

The exact solutions of the new generalized (3+1)-dimensional Kadomtsev-Petviashvili (ngKP) equation by using the modified extended tanh-function method, the improved (

G
′

/

G

) method and the generalized Riccati equation mapping method are considered. Different types of exact traveling wave solutions are obtained, enriching the exact solutions of this equation. In addition, the dynamical behaviors of the different types of solutions obtained by the equation are graphically presented using 3D, 2D and density plots. Then, the phase portraits of the equations are obtained through the bifurcation theory to verify the validity of the previous three methods. Finally, the comparison between our results and the known results is given, it can be concluded that we have provided a large number of new travelling wave solutions to the equation.
The effect of quantum decoherence on inflationary gravitational waves
Authors: de Kruijf Jessie , Bartolo Nicola
Published: November 2024

The theory of inflation provides a mechanism to explain the structures we observe today in the Universe, starting from quantum-mechanically generated fluctuations. However, this leaves the question of: how did the quantum-to-classical transition, occur? During inflation, tensor perturbations interact (at least gravitationally) with other fields, meaning that we need to view these perturbations as an open system that interacts with an environment. In this paper, the evolution of the system is described using a Lindblad equation, which describes the quantum decoherence of the system. This is a possible mechanism for explaining the quantum-to-classical transition. We show that this quantum decoherence during a de Sitter phase leads to a scale-dependent increase of the gravitational wave power spectrum, depending on the strength and time dependence of the interaction between the system and the environment. By using current upper bounds on the gravitational wave power spectrum from inflation, obtained from CMB and the LIGO-Virgo-KAGRA constraints, we find an upper bound on the interaction strength. Furthermore, we compute the decoherence criterion, which indicates the minimal interaction strength needed for a specific scale to have successfully decohered by the end of inflation. Assuming that the CMB modes have completely decohered, we indicate a lower bound on the interaction strength. In addition, this decoherence criterion allows us to look at which scales might not have fully decohered and could still show some relic quantum signatures. Lastly, we use sensitivity forecasts to study how future gravitational-wave detectors, such as LISA and ET, could constrain the decoherence parameter space. Due to the scale-dependence of the power spectrum, LISA could only have a very small impact. However, ET will be able to significantly improve our current constraints for specific decoherence scenarios.
Kerr black hole mimickers sourced by a string fluid
Authors: Brustein Ram , Medved A.J.M. , Simhon Tamar
Published: November 2024

We present rotating solutions of Einstein's gravity coupled to an effective Born-Infeld theory that describes the end of open-string tachyon condensation after the decay of an unstable D-brane or a brane-antibrane system. The geometry of these solutions is that of the rotating frozen star. The solutions are stationary, ultracompact, can be made non-singular via a regularization procedure and their exterior geometry is identical, for all practical purposes, to that of the Kerr solution. The Born-Infeld matter consists of radial electric-flux tubes that emanate from, or end at, the ellipsoidal core of the star. Each end of the flux tubes carries an electric charge, so that the electric field can be viewed as being sourced by an ellipsoidal charge distribution of positive and negative charges near the center of the star. Meanwhile, the star's outer layer is equal and oppositely charged, resulting in a vanishing electric field in the external spacetime. We show that these rotating solutions are ultrastable against radial perturbations, just like their static frozen star counterparts. They are also effectively immune to ergoregion instabilities, as we discuss.
Primordial black holes and scalar induced density perturbations: the effects of probability density functions*
Authors: Zhou 周 Jing-Zhi 敬之 , Kuang 况 Yu-Ting 宇庭 , Chang 常 Zhe 哲 , Zhang 张 Xukun 旭坤 , Zhu 朱 Qing-Hua 庆华
Published: November 2024

We investigate the second order energy density perturbation

induced by small-scale Gaussian and local-type non-Gaussian primordial curvature perturbations. The relative abundance of primordial black holes (PBHs) is calculated in terms of the probability density functions (PDFs) of the total energy density perturbation

. The effects of the second order density perturbation greatly reduce the upper bounds of small-scale power spectra of primordial curvature perturbations by one to two orders of magnitude. For a log-normal primordial power spectrum, its amplitude

is constrained to be approximately

, and for the local-type non-Gaussianity with

, the upper bound of

is approximately

.
Climate shapes baseflows, influencing drought severity
Authors: Zaerpour Masoud , Hatami Shadi , Ballarin André S , Papalexiou Simon Michael , Pietroniro Alain , Adamowski Jan Franklin
Published: November 2024

Baseflow, the sustained flow from groundwater, lakes, and snowmelt, is essential for maintaining surface water flow, particularly during droughts. Amid rising global water demands and climate change impacts, understanding baseflow dynamics is crucial for water resource management. This study offers new insights by assessing baseflow controls at finer temporal scales and examining their relationship with hydrological drought flows. We investigate how climatic factors influence seasonal baseflow in 7138 global catchments across five major climate regions. Our analysis identifies precipitation as the primary driver, affecting 58.3% of catchments, though its impact varies significantly across different climates. In temperate regions, precipitation dominates (61.9% of catchments), while in tropical regions, evaporative demand is the leading factor (47.3%). Snow fraction is particularly crucial in both snow-dominated (20.8%) and polar regions (48.5%). Negative baseflow trends generally emerge where the effects of evaporative demand or snow fraction outweigh those of precipitation. Specifically, in northern regions and the Rocky Mountains, where snow fraction predominantly controls baseflow changes, a negative trend is evident. Similarly, in tropical catchments, where evaporative demand drives baseflow changes, this also leads to a negative trend. Additionally, our findings indicate that baseflow changes are closely linked to hydrologic drought severity, with concurrent trends observed in 69% of catchments. These findings highlight the relationship between baseflow changes, the severity of hydrologic drought and shifts in precipitation, evaporative demand, and snow dynamics. This study provides crucial insights for sustainable water resource planning and climate change adaptation, emphasizing the importance of managing groundwater-fed river flows to mitigate drought impacts.
Diverse impacts of sea ice and ice shelf melting on phytoplankton communities in the Cosmonaut Sea, East Antarctica
Authors: Qi Qianqian , Hao Qiang , Yang Guang , Cao Shunan , Kang Jiawen , Hu Jiashun , Zheng Minfang , Chen Mengya , He Jianfeng , Chen Min
Published: November 2024

Antarctic sea ice and glacier melt profoundly impacts marine ecosystems. Our study in the Cosmonaut Sea summer measures seawater oxygen isotopes, size-fractionated chlorophyll-a, and phytoplankton communities. We quantify sea ice meltwater, meteoric water, and winter water contents using a Bayesian isotope-mixing model. Contrary to common belief, our findings suggest that the reduced net export of sea ice to the north and the basal melting of ice shelves have deepened the mixed layer in coastal waters, altering the survival depth of phytoplankton. Freshwater primarily stimulates phytoplankton growth by supplying dissolved iron rather than by increasing water stability, which influences the size distribution and species composition of the phytoplankton community. These insights highlight the complex interplay between freshwater inputs, nutrient dynamics, and phytoplankton communities, and are crucial for understanding the dynamics of Antarctic ecosystem and its vulnerability to climate change.
Graded colour Lie superalgebras for solving Lévy-Leblond equations
Authors: Ryan Mitchell
Published: November 2024

The Lévy-Leblond equation with free potential admits a symmetry algebra that is a

Z

2

×

Z

2

-graded colour Lie superalgebra (see Aizawa–Kuznetsova–Tanaka–Toppan, 2016). We extend this result in two directions by considering a time-independent version of the Lévy-Leblond equation. First, we construct a

Z

2
3

-graded colour Lie superalgebra containing operators that leave the eigenspaces invariant and demonstrate the utility of this algebra in constructing general solutions for the free equation. Second, we find that the ladder operators for the harmonic oscillator generate a

Z

2

×

Z

2

-graded colour Lie superalgebra and we use the operators from this algebra to compute the spectrum. These results illustrate two points: the Lévy-Leblond equation admits colour Lie superalgebras with gradings higher than

Z

2

×

Z

2

and colour Lie superalgebras appear for potentials besides the free potential.
A review of sugarcane bagasse ash: Characteristics, properties and sustainable applications in concrete
Authors: Goyal Pratyush Kumar , Murmu Meena
Published: November 2024

Concrete is among the most utilized construction materials in the world, with cement as a primary component. Integrating Sugarcane Bagasse Ash (SCBA) into concrete production offers solutions for utilizing this agro-industrial byproduct while reducing environmental impacts. This includes minimizing the need for limestone removal in cement production, thereby lowering carbon dioxide emissions and preserving natural deposits for cement manufacturing. To address this challenge, researchers and practitioners are increasingly exploring sustainable alternatives to traditional concrete components. This review focuses on sustainable applications in concrete, with a specific emphasis on environmentally friendly materials and practices that can reduce the carbon footprint of concrete production and improve its long-term sustainability. Sugarcane bagasse ash (SCBA) is a byproduct of the sugar industry used as a sustainable alternative material in concrete production. A comprehensive review provides an overview of the characteristics and properties of SCBA, as well as its sustainable applications in concrete. This paper examines the physical properties and chemical composition of SCBA, emphasizing its potential as a supplementary cementitious material. Various studies on the use of Sugarcane bagasse ash in concrete mixtures are summarized, focusing on its effects on workability by slump test of concrete may increase or decrease with different SCBA concentrations. Additionally, it explores the effects on mechanical properties, durability evaluated via water absorption tests, and microstructural properties of concrete. Generally, concrete containing SCBA exhibits improved mechanical properties with increased SCBA substitution, with an optimal replacement ratio ranging from 5% to 15%.
Application of the theory of planned behaviour to assess the impact of the intention of architects, designers, and engineers regarding the usage of sustainable construction materials (SCM) in India
Authors: Joshi R , Vashishtha K , Tripathi S , Roy S , Dhankar C
Published: November 2024

The present interdisciplinary (psychology and architecture) study was conducted to assess the impact of intention on the behaviour of architects, designers, and engineers related to the recommendation and usage of sustainable construction materials (SCM). The authors employed the theoretical framework of planned behaviour (TPB) on sustainable construction materials usage by different stakeholders and developed a questionnaire based on the same. Fifty-nine architects/designers and engineers filled out the developed questionnaire after giving their written informed consent. The survey was followed by semi semi-structured interview schedule, developed by the researchers. The results demonstrated that the intention to use SCM was present, but it was not reflected much in the actual behaviour. The semi-structured interview schedules findings like attitude, social norms, perceived effectiveness, and value proved to have influenced intention, which in turn influenced actual behaviour. The results of the study were substantiated by themes generated by semi-structured interviews that were conducted with architects, interior designers, and civil engineers which were lack of adequate research on the development of sustainable construction materials, economic constraints, and lack of skilled labourers for construction with vernacular or traditional construction materials. The findings of the study can be used for comprehension and implications for sustainable construction materials usage. In the present scenario, the findings of the study are important as sustainable construction materials are the need of the hour owing to severe climate damage and for resolving unmet challenges of urbanization.
Imparting concepts of sustainability and green buildings via a case study on an educational building
Authors: Kona Mahesh , Pamu Yashwanth , Bommisetty Jagadeesh , Samarthi Praveen
Published: November 2024

Sustainable building construction is the need of the hour for any developing nation. Sustainable or Green buildings mainly focus on the conservation of energy, water, and other scarce resources. Indian Green Buildings Council (IGBC) and Green Rating for Integrated Habitat Assessment (GRIHA) are two organizations in India which certifies buildings of various categories based on the sustainable practices adopted in the buildings. Certification is given for existing as well as new buildings. This paper attempts to evaluate the sustainable features of an existing school as per IGBC standards. The study revealed that the school under consideration has few sustainable features. Very few points were scored in the most important criteria i.e., water efficiency and energy efficiency, which contributes to more than 50% of the total points. The existing school building can be converted into a green building with certain modifications to the existing school infrastructure. This detailed study on various existing features of the building will help the school authorities to improve the building for a sustainable environment to the school students.
Groundwater remediation techniques around Kodungaiyur dump yard
Authors: Aishwarya R. , Hemamathi A. , Sukumar Binu , Yuvaraj M.
Published: November 2024

The groundwater around the Kodungaiyur dump yard, in Tamil Nadu, India, is polluted due to the percolation of leachate from the dumpsite. This paper proposes three remedial techniques to make the groundwater drinkable for the people living near the Kodungaiyur trash yard. Twelve bore wells around the Kodungaiyur dumpsite provided water samples for which the physicochemical parameters were measured. Moderately high concentrations of Total Hardness (TH), Total Alkalinity (TA), Chloride, Sulphate, Nitrate, Sodium, and Total Dissolved Solids (TDS) are present in the groundwater around the dump yard. The Physicochemical parameters of the samples tend to deviate from the standards prescribed by WHO and BIS. Therefore, remedial measures such as solar distillation, Activated Charcoal, and the Phytoremediation process are suggested to reduce the contaminants in the groundwater. The activated charcoal removes the unpleasant color of the water completely and makes the water clear and transparent through filtration. The solar distillation process does not affect the pH value and is reduced by 4.5% in the phytoremediation technique. Similarly, the level of chlorides is reduced by 99% in solar distillation and by 56% in the phytoremediation technique. Total hardness is reduced by 89.88% in the solar still process and 56.65% in the phytoremediation technique. Sodium is reduced by 99.88% in solar still and 57.03% in the phytoremediation technique. The economical and eco-friendly nature of the suggested techniques makes it sustainable for future generations.
Optimal placement of shear wall in multistorey buildings on sloping ground
Authors: Ghangare N. C. , Meshram S. S. , Wasalwar V. U.
Published: November 2024

High-rise buildings most frequently use shear wall systems as one of their lateral load-resisting techniques. The great plane stiffness and strength of shear walls allow them to withstand significant horizontal loads and gravity stresses, making them particularly valuable in many structural engineering applications. The main objective of this research project is to identify the optimal position for shear walls in multistorey buildings with sloping terrain. A ten-story RCC building located in a zone IV seismically active location and slopes. An earthquake load is calculated using the comparable static technique with IS 1893 (PART–I):2016. The software utilized for these assessments was STAAD Pro V8i. An extensive investigation was carried out to examine several factors, including average displacement, period, story shear, story drift, reinforcement reduction, and G+10 story building on sloping terrain. Including shear walls has become indispensable in multistorey buildings to effectively withstand lateral forces. A comparison between the bare frame structure and the shear wall applied structure is shown.