bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of entransy loss analysis and the first law of thermodynamics in the optimization of organic Rankine cycle coupled with parabolic trough collector
Authors: Faghih Saeed , Pourshaghaghy Alireza , Maroufi Arman
Published: October 2024

Due to the numerous environmental issues associated with fossil fuel power plants, using solar energy to generate electricity is a viable alternative. The organic Rankine cycle (ORC) is a thermodynamic process used to convert low- and medium-temperature heat sources into electricity, often utilizing organic fluids as the working medium. Entransy is a relatively new concept that many readers may not be familiar with. Moreover, entransy loss (Ġloss) is derived from the entransy concept, which quantifies the inefficiency in transferring thermal energy through a system. In this study, (Ġloss) is used for the first time when designing an ORC cycle coupled with parabolic trough collectors. The entransy loss relations were driven with assumption that the heat capacity is a function of temperature. A genetic algorithm is a search heuristic inspired by natural selection. It is used to find optimal or near-optimal solutions to complex problems by evolving a population of candidate solutions. Two scenarios utilized the genetic algorithm in MATLAB to optimize the system (scenario 1: maximizing the output power and scenario 2: maximizing the Ġloss). In addition, the optimization parameters included turbine inlet temperature (Ttur), boiler pressure (Pboil), condenser pressure (Pcond), and the temperature of the collector fluid at the boiler outlet (Thf,out). This optimization was performed for the temperature of the collector fluid at the boiler inlet (Thf,in) in the range 310–400 °C at 10 °C intervals with four working fluids (i.e., toluene, cyclohexane, MM, and water). The land area and the beam solar radiation were considered to be 100 hectares and 800 W/m2, respectively. The results indicated that according to scenario one, at temperatures of 310–320 °C, the maximum power was obtained for the case of toluene fluid with values 59.8 and 63.5 MW. For the collector fluid temperature from 330 to 400 °C, water had the most optimal power with values ranging from 66.2 to 88.2 MW. Furthermore, toluene exhibited superiority to two other organic fluids in the 330–400 °C temperature range after water, with net power values ranged between 65.7 and 76.3 MW. The results indicated that the maximum entransy loss does not correspond to the maximum output power because the application preconditions of the entransy loss concept are not all satisfied. Across all working fluids and Thf,in, scenario 2 resulted in lower optimal output power, cycle efficiency, and system efficiency compared to scenario 1.
Predicting creep behavior in composites from microstructural features using deep learning
Authors: Gu Aijun , Sang Sheng
Published: October 2024

This study uses a multilayer perceptron deep learning model to predict creep strain vs time curves in composite materials based on their microstructural features. Finite element simulations generate ground truth data for model training and validation. The multilayer perceptron model, trained on this comprehensive dataset, effectively captures the complex relationships between the microstructure and creep behavior, achieving high accuracy. Comparative analysis with traditional models shows the multilayer perceptron model’s superior performance. This demonstrates the model’s potential for reliable application in various engineering fields, offering improved predictions of composite material behavior under creep conditions.
Simultaneously measuring microwave electric fields at different frequencies by Rydberg-atom-based electrometry with Zeeman-resolved Autler–Townes splitting
Authors: Wang Yuxiang , Liu Yuqing , Zhang Qianyi , Gong Pengwei , Xie Wen , Wu Zinan , Jia Fengdong , Zhong Zhi-Ping
Published: October 2024

We provide the simultaneous traceable measurements of microwave electric fields at two different frequencies by the electromagnetically induced transparency (EIT) and Autler–Townes (AT) splitting. A static magnetic field working together with a linearly polarized probe and coupling light prepares Rydberg atoms in Zeeman sublevels with maximal |mJ| in an atomic vapor cell. Using the EIT-AT splitting of these two maximal |mJ| states, the microwave electric fields at two different frequencies are simultaneously measured, in which their frequency difference can be adjustable within the linear range of magnetic field-induced level shifts. The proposed method provides a promising prospect for calibrating multiple microwave frequencies simultaneously in the future.
Physics, AI, and the future of discovery
Authors: Córdova France , Browning Valerie , Copan Walter , Gousev Evgeni , Thaler Jesse
Published: October 2024

Leaders from industry, government, and academia discuss the potential impact of AI on physics—including neutrinos, exoplanets, term papers, outreach, and workforce gaps—and of physics on AI.
Multi-word units in neural machine translation
Authors: Colson Jean-Pierre
Published: October 2024

Neural machine translation (NMT) has recently made significant progress in improving the quality of
the texts it produces. New features of NMT include the fluidity of translations and the successful handling of
multi-word units. In this paper we first report the results of an automated evaluation of the percentage of
phraseology in the translations produced by Google Translate and DeepL. A corpus-based approach makes it possible to
estimate that both NMT systems succeed in producing an average percentage of phraseology that is quite reasonable and
sometimes even higher than in natural language production by native speakers. However, a closer look at some
problematic cases shows that the ability of NMT systems to treat phraseological units can be deceptive, as they are
often unable to cope with contextual complexity and low-frequency idioms.
Evaluating the Italian-English machine translation quality of MWUs in the domain of archaeology
Authors: Speranza Giulia , Monti Johanna
Published: October 2024

Multiword units (MWUs) represent a challenging and problematic linguistic issue in the field of
Natural Language Processing (NLP) due to their idiosyncratic nature. This paper investigates the quality of Neural
Machine Translation (NMT) outputs when dealing with MWUs in the domain of archaeology. As a case study, a dataset of
100 MWUs is used as a Gold Standard to evaluate out-of-context and in-context translation outputs from three
state-of-the-art NMT systems for the Italian-English language pair: Google Translate, DeepL, and Microsoft Bing
Translator. MT outputs are manually evaluated with reference to the Gold Standard, namely out-of-context and
in-context human English translations of the selected 100 MWUs. Results show that terminology is still a problematic
category for MT quality and that MWUs translation may vary, and sometimes even improve, when further context is
provided.
Verb collocations and their semantics in the specialized language of science
Authors: Jiménez-Navarro Eva Lucía
Published: October 2024

This chapter is concerned with verb collocations in the specialized language of science. I pay
attention to their semanticity, since my main objective is to discover the topics evoked in terms of their integrating
elements. The methodology applied is as follows: first, I compile a specialized corpus of research articles; second, I
automatically extract a list of collocation candidates, which is manually revised; third, the selected collocations
are semantically classified. As this work is motivated by a previous study on noun collocations, I perform a
comparative analysis. The findings are that noun and verb collocations share similar semantic frames, although the
method employed in each study yields different, but complementary, results.
Negative–positive adjective pairing in travel journalism in English, Italian, and Polish
Authors: Brett David , Pinna Antonio , Loranc Barbara
Published: October 2024

Adjectives play a particular role in the language of tourism and often contribute to the formation
of recurrent phraseologies (Manca, 2008). The combination of adjectives
bearing negative and positive connotation is widely reported in the literature (Dann, 1996; Edo Marzá, 2011, 2012). Durán-Muñoz (2019) focuses on the ADJ+but+ADJ pattern in
an English language corpus of Adventure Tourism texts. This contribution examines the same pattern in 1M word corpora
of travel journalism, examining examples in English, but also extending the analysis to Italian and Polish, to
determine whether the pattern is limited to one language, or whether it is widely used as a discourse strategy within
the same register, regardless of the code adopted.
Irony in American-English tweets
Authors: Martín-Gascón Beatriz
Published: October 2024

The present study examines verbal irony from a cognitive linguistics perspective, based on Ruiz de Mendoza’s (2017) development of the echoic account and on big data.
Built on previous research on the detection of Spanish ironic utterances in Twitter (Martín-Gascón, 2019),1 this investigation aims to
analyze how American-English speakers conceptualize and express irony and compares findings to the Spanish ones. The
dataset, initially consisting of 1,157,773,379 tweets from 248 countries and 66 languages, was first reduced to 27,517
tweets from English-speaking users in the United States using the words “irony”, “ironies”, and “ironic”, then to 605
containing the words as hashtag and finally to 495 tweets evincing implicit and explicit-echoic irony. An in-depth
cognitive and qualitative analysis of the sample revealed the complexities of perceiving irony in written discourse
and, therefore, the relevance of adding contextual ironic markers, such as hashtags, emojis, interjections, laughter
typing and ironic phraseology, among others. In line with Martín-Gascón’s
(2019) study, findings showed a higher use of positive and explicit-echoic irony as compared to implicit
and negative irony. By drawing attention to the similarities and differences in the expression of irony, we expect to
offer preliminary informed options for the design of pedagogical proposals that enhance not only the learners’
linguistic and ironic competencies, but also their intercultural awareness.
Vocabulary sophistication in children’s L2 school writing
Authors: Durrant Philip , Dirdal Hildegunn , Tveitan Veronica Dahlby
Published: October 2024

This paper tests three hypotheses about written vocabulary in child L2 English. Specifically, as children mature,
(1) the mean frequency values of the nouns they use increase; (2) the mean frequencies of other parts-of-speech decrease; (3) the
use of academic vocabulary increases only in certain types of writing. Using a corpus of writing by children in Norway, hypothesis
1 was confirmed up to the mid-teenage years. The mean frequency values of nouns then decreased. Analysis showed that the early
increase is due to decreased repetition of low-frequency topic words. After age 15, frequencies drop as the main source of
vocabulary moves from a region around the 150th most frequent lemma to one around the 550th. Hypotheses 2 and 3 were partially
confirmed. Mean frequencies of non-nouns decreased in non-stories after Year 9. Non-stories became more academic across school
years. Stories had much lower scores overall but also showed an increase at Year 10.
Artificial Intelligence and Linguistic Landscape research
Authors: Voss Erik
Published: October 2024

This article explores applications of artificial intelligence (AI) technologies in Linguistic Landscape research.
Traditionally, LL research has relied on manual data collection and analysis, often involving photographs of public signage,
advertisements, and other visual language displays. However, this manual approach can present challenges, including time-consuming
data collection, inconsistent data quality, and potential researcher bias. Two AI technologies in particular hold promise for
addressing these challenges in LL research: computer vision (CV) and large language models (LLMs). CV automates the identification
and extraction of text from images, improving data accuracy and enabling large-scale image analysis. LLMs, based on natural
language processing, can detect, translate, and interpret multilingual text. This article explores the affordances and challenges
of using AI technologies in LL research and discusses methods to improve data collection, enhance accuracy, and support the
analysis of multilingual environments. It also raises ethical issues and limitations of the technologies.
Chapter 4. Investigating reply relations on Wikipedia talk pages to reconstruct interactional strategies of Wikipedia authors
Authors: Herzberg Laura , Lüngen Harald
Published: October 2024

This chapter presents the annotation and analysis of interpretative reply relations on Wikipedia talk pages using data from the WikiDemoCorpus (WDC). Building on an approach of annotating interpretative reply relations to analyze these relations in Wikipedia talk page posts, the chapter presents nine reply relation categories found in the German WDC. Additionally, linguistic cues for each category and the Wikipedia discussion pages overall are explained in detail, illustrated through reply relation targets. The results of the linguistic annotation are threefold: First, we provide an annotation scheme that can be used by third parties to produce more data according to their needs. Second, we shed light on and quantify the numerous ways Wikipedia authors reply to each other’s posts on talk pages. Finally, we provide richly annotated data that can be used for further analyses, such as identifying interactional relations on higher levels or training tasks in machine learning algorithms.
Chapter 7. Live exploration of Wikipedia editing dynamics with visual analytics
Authors: Flöck Fabian , Ulloa Roberto , Acosta Maribel
Published: October 2024

The revision histories of Wikipedia articles are a rich source of data about the interactions of editors with each other and with the content, yet they are not straightforward to mine or understand. We describe two tools for visual analytics that support this effort: (i) An interactive browser extension to study word authorship, age, and conflict dynamics, which provides an overlay on live Wikipedia articles; and (ii) a novel interactive Jupyter Notebook package that allows us to run analyses of editorial dynamics out-of-the-box and is easily modifiable. Both leverage live data for any article on demand from several Web APIs, centering on our own WikiWho service, providing the most accurate mining of live word-level changes currently available. We show how these tools enable the exploration of the survival of content, productivity of editors, conflict dynamics, and other metrics through low-barrier interfaces while providing the opportunity for more quantitative investigations via access to the notebooks’ underlying data structures.
Chapter 9. To each their own truth
Authors: Carbou Guillaume , Ho-Dac Lydia-Mai , Poudat Céline , Sahut Gilles
Published: October 2024

This chapter presents five epistemic regimes we defined for characterizing the conception of “truth” that underpin debates amongst Wikipedian editors on talk pages. The chapter starts by defining each epistemic regime and how it could be understood according to the Wikipedia rules. Then, we propose a method to evaluate the operationality of these regimes from a corpus standpoint and to analyse to what extent these regimes are adopted by Wikipedians. The analysis of the annotation of 324 posts extracted from the French WikiDemoCorpus largely supports our epistemic model and provides new insights into the ideological backgrounds of Wikipedians.
Basophils: Regulators of lung inflammation over space and time
Authors: Joulia Régis , Lloyd Clare M.
Published: October 2024

In this issue of JEM, Schuijs et al. (https://doi.org/10.1084/jem.20240103) highlight a novel role for basophils during allergic immune responses to house dust mites (HDM). They reveal that interleukin-33 (IL-33)-activated basophils facilitate the recruitment and extravasation of Th2 cells into the lungs during a specific time frame via their interactions with pulmonary endothelial cells.
Generation of Circularly Polarized Strong-Field Terahertz Waves
Authors: Li 李 Jiang-Hao 江皓 , Xiong 熊 Hong-Ting 虹婷 , Kong 孔 De-Yin 德胤 , Zhao 赵 Wei-Peng 蔚鹏 , Liu 刘 Shao-Jie 少杰 , Quan 全 Bao-Gang 保刚 , Wu 吴 Xiao-Jun 晓君
Published: October 2024

Terahertz (THz) circular dichroism (TCD) spectroscopy is extensively used to examine the chiral properties of biological macromolecules and other materials. The rapid advancements in strong-field THz generation and field-modulated techniques highlights the importance of advancing tunable strong-field TCD spectroscopy technology. In this study, we designed and implemented an integrated strong-field TCD spectroscopy system. By using a tilted-pulse-front technique, we generated linearly polarized strong-field THz radiation and achieved linear-to-circular polarization conversion via a reflective metasurface. The resulting circularly polarized THz radiation exhibited an ellipticity greater than 0.9 in the frequency range of 0.38–0.61 THz, achieving a linear-to-circular conversion efficiency exceeding 90%. Additionally, the peak electric field strength of the circularly polarized THz radiation exceeded 100 kV/cm. The proposed system is expected to be instrumental in investigating the chiral characteristics of materials under strong field conditions and in examining how these characteristics vary under different field conditions.
A new Marshall-Olkin generalized-k family of distributions with applications
Authors: Naz Sidra , Tahir M H , Jamal Farrukh , Elgarhy Mohammed , Shafiq Shakaiba , Alsadat Najwan , Nagarjuna Vasili B V
Published: October 2024

In this article, we describe a new Marshall-Olkin family of distributions based on the Marshall-Olkin family of distributions by employing a different generator. We have derived several statistical properties of the new Marshall-Olkin family, including survival function, hazard rate function, quantile function, moments, and linear representation. We have taken the Weibull distribution as a baseline distribution and found that the new Marshall-Olkin Weibull distribution exhibits a variety of shapes for its hazard rates and densities. We have tested the performance of various estimation methods for the new Marshall-Olkin family of distributions, including eight different estimation methods. Additionally, we conducted extensive simulations to assess the robustness of the estimation methods across various scenarios and determine which methods are most effective for varying sample sizes. To further validate the new Marshall-Olkin Weibull distribution, we have used two different data sets to compare the fitted new Marshall-Olkin Weibull distribution with the well-known comparative models. By testing the performance of different estimation methods and using multiple data sets, we can demonstrate the versatility and usefulness of the new Marshall-Olkin family of distributions for modeling a wide range of phenomena.
Study on the uniaxial tensile mechanical behavior of two-dimensional single-crystal aluminum nitride
Authors: He Yan , Wang Kaiyuan , Tang Meiling , Fan Lin , Sun Jingting , Gao Xingjun
Published: October 2024

To investigate the tensile behavior and mechanical properties of single-crystal aluminum nitride (AlN) at the microscopic level, molecular dynamics simulations were used to study the effects of crystal orientation, strain rate, environmental temperature, and hole defect size on fracture strength, fracture mechanism, and potential energy during uniaxial tensile. The results show that the tensile strength of AlN in the [100] crystal direction is stronger. The anisotropic behavior characteristics of Al-N bonds fracture mechanism, crack growth rate, and cracking degree are significant when stretched along the [100], [010], and [110] crystal directions. Under high temperature condition, the lattice structure undergoes changes, causing grain boundaries to move and slip. This facilitates the breaking of bonds, leading to a decrease in tensile strength and a reduction in stored potential energy. Hole defects cause more lattice damage, reducing the energy required for Al-N bonds breakage and facilitating the propagation of microcracks. Additionally, it was found that the strain rate affects the stress–strain behavior of the model. An increase in strain rate leads to an increase in breaking stress, and the rapid deformation of AlN results in more energy being stored in the lattice in the form of potential energy. Therefore, the tensile strength and potential energy are improved.
Implementation of adders using XOR gates in quantum-dot cellular automata with physical verification
Authors: Shaw Rohit Kumar , Khan Angshuman
Published: October 2024

This paper presents a promising approach to nanoscale computing, offering significant advantages through the QCA technology. It suggests a highly efficient, scalable, and reliable multilayered QCA half and full adder circuits, leveraging a three-input QCA XOR gate. The proposed full adder layout demonstrates significant improvements in various parameters, including area, latency, and energy dissipation. In particular, it offers 17% greater area efficiency and utilizes 14 fewer cells compared to the best work existing work. We thoroughly evaluated energy dissipation using the QCADesigner-E tool. We also examined the cost functions, with a QCA-specific cost of 22 units, which is ∼37% better than earlier designs. The architecture is strategically designed with externally accessible input and output nodes to ensure seamless scalability. Physical reliability is ensured through kink energy calculations for the suitability of higher-order circuit designs. Practical applications of the proposed blocks include their use in arithmetic logic units (ALUs), digital signal processors, and other modern processing and computing systems. This work sets a new benchmark for future developments in QCA technology, offering a robust, efficient, and versatile solution for advanced nano-processing and computing systems.
The electromagnetic field of a circular parallel plate capacitor excited by an AC current and AC voltage supply
Authors: Han Shejiao , He Jiaqi , Li Cunzhi
Published: October 2024

This study investigates the electromagnetic field (EMF) distribution of an ideal circular parallel plate capacitor excited by a time-harmonic power source. Considering the lead wire and capacitor as a charged whole, we formulate the boundary value problems of the Helmholtz equation for the EMF in the lead wire space and capacitor space, respectively. First, we solve for the EMF generated by the total current in the lead wire space of an AC current. Following this, we solve for the EMF boundary value problem of a capacitor filled with linear, uniform, isotropic, and non-magnetic lossy dielectric under an AC current excitation, using the continuity of the total current as a basis. Second, the EMF distributions in the capacitor space and the lead wire space under an AC voltage excitation are provided, following the principles of the generalized Helmholtz theorem. Third, the EMF distribution is discussed when the electromagnetic ‘standing-wave phenomenon’ occurs in the ideal dielectric capacitor, and identify the ‘resonance phenomenon’ and the ‘current-stopping phenomenon’ of the capacitor's EMF when excited by an AC current and AC voltage, respectively. We also present the corresponding ‘resonance frequency’ and ‘current-stopping frequency’. Finally, we explore the quasi-stable solution of the capacitor's EMF under low-frequency condition and the static solutions of the electric and magnetic fields under DC excitation and static voltage excitation. Our findings suggest that the existing formula for the capacitor's EMF approximates our analytical solution under quasi-stable condition.
Electric trucks pantograph-catenary interaction condition monitoring method based on semantic segmentation network and linear fitting
Authors: Li Fan , Chen Zhichao , Yang Jie , Feng Zhicheng
Published: October 2024

The pantograph-catenary system (PCS) in dual-source electric trucks is crucial for maintaining a stable connection to the power grid, which directly impacts power quality. Ensuring reliable contact between the pantograph and catenary requires accurate detection of the contact point (CPT). However, existing CPT detection methods designed for trains are not well-suited for electric trucks due to differences in structural design. To address this challenge, this paper proposes a novel CPT detection method that integrates semantic segmentation and linear fitting techniques. Firstly, we introduce a lightweight Pantograph and Contact Line Segmentation Network (PCSN), which accurately extracts the regions of the pantograph and contact line. Secondly, a position correction algorithm combined with a least-squares linear fitting technique is employed to detect the CPT of electric trucks. Experimental results demonstrate that the proposed method achieves a detection error within ±5 pixels. In terms of processing speed, it reaches 76.9 FPS on an RTX 3080 GPU, 47.13 FPS on an Intel I9-12900 CPU, and 11.63 FPS on an embedded Jetson TX2 device.
THz biosensing for early detection of influenza and coronaviruses using dielectric metamaterials
Authors: Patri Upender , Kumar Amarjit
Published: October 2024

The world has faced a significant challenge since December 2019, when coronavirus (COVID-19) was found. Viruses of this type are causing pandemics all over the world right now. For this purpose, a biosensor is designed to operate based on metamaterial (MM) incorporated and can detect different coronaviruses. The proposed metamaterial absorber (MMA) includes two bands with perfect absorption characteristics and a narrow absorption bandwidth: 4.093 THz and 3.647 THz. The circuit model’s transmission line technique is another approach to verifying the absorber’s functionality. The proposed design consists of a square-shaped graphene ring (SGR) and a silicon-based square ring resonator (SSRR) to provide unique and narrow band absorption characteristics. Changing the graphene’s chemical potential suggests MMA tuneability and control capability. The suggested MMA can detect several coronaviruses because of its extremely narrow absorption spectrum behavior. It has unique features such as ultra-narrow absorption bandwidth, polarization insensitivity, and simplicity. The MMA is designed with a compact structure, good sensitivity (s), exceptional figure of Merit (FOM), and superior Quality factor (Q) values.
Metal-to-insulator phase transition of molybdenum oxide for reversible writing and erasing information encryption
Authors: Zhao Jianxing , Zhou Yao , Zhang Gong , Zhou Jianhong
Published: October 2024

Recent research on structural color manipulation is focusing on integrating phase change material (PCM) in plasmonic structures. Commonly reported PCM integrated plasmonic structures can only achieve information manipulation by switching images between different colors. In this paper, we have reported a theoretical design of reversibly switching colored information between visible and invisible simply using a MoOx based two layered structure. In our design, the MoOx layer can be switched between two phases, i.e., metallic MoO2 and insulating MoO3. The phase transition of MoOx possesses very complicated processes, which makes it advantageous for information encryption. Generally, in the proposed structure with metallic MoO2, various colors can be generated due to the F-P enhanced absorption at wavelengths where construction interference occurs. However, owing to the low loss of insulating MoO3 in visible region, the absorption is low though out the whole visible region. Thus all colors can be erased to white. Therefore, the colored information can be written and erased with our proposed structure by switching MoOx between metallic MoO2 and insulating MoO3. Utilizing the designed structure, we presented two kinds of devices possessing the functions of image ‘writing and erasing’ to verify the possibility of application in information encryption. The proposed image encryption device can be acquired easily by masking and coating processes. We believe our results provides a new way in designing encryption devices.
Effects of anode geometry on DC magnetron sputtering of copper oxide films deposition
Authors: Kakwan Athar Mumtaz , Ali Syed Rizwan
Published: October 2024

Effects of anode shape are examined in a custom-made DC magnetron sputtering system. Polycrystalline copper-oxide (CuO) films are deposited using wedge, ring and disc shaped anodes. Current–voltage (I-V) characteristics of the discharge were fitted with models of plasma discharge. Above 700 V a notable rise in average plasma impedance, from approximately 2 kΩ to 7 kΩ, was observed. Scanning electron microscope (SEM) images reveal uniform and porous film growth. The deposition increased significantly with increasing the anode surface area due to decrease in gas density in cathode sheath. For all the anode shapes tested, the deposition rates were higher in magnetron sputtering compared to DC sputtering mode. X-ray diffraction (XRD) of the films deposited with the disk anode revealed polycrystalline films with predominant CuO phase. With increasing sputtering power, average crystallite size vary from 11 nm to 21 nm, dislocation density vary from approximately

8.4
×

10

−
3

nm−2 to

2.3
×

10

−
3

nm−2 and micro strain from approximately

3.3
×

10

−
3

to

1.7
×

10

−
3

.

This indicate that higher sputtering at higher powers produce higher quality films. Atomic force microscopy revealed that the rms roughness of the samples is about 4 nm.
Cosmological Bell tests with decoherence effects
Authors: Sou Chon Man , Wang Junqi , Wang Yi
Published: October 2024

The inflationary universe creates particle pairs, which are entangled in their momenta due to momentum conservation. Operators involving the momenta of the fluctuations can be rewritten into pseudo-spin operators, such as the Gour-Khanna-Mann-Revzen (GKMR) pseudo-spin. Making use of these pseudo-spin operators, cosmological Bell inequalities can be formulated. The violation of these Bell inequalities indicates the quantum nature of primordial fluctuations.

In this work, we focus on primordial curvature perturbations. Since curvature perturbations arise from gravity, their action includes the Gibbons-Hawking-York boundary term. We clarify the role of the boundary term in selecting suitable initial conditions for linear perturbations.

After that, we proceed to the interactions of cosmological perturbations, including the bulk and boundary interaction terms, which introduce decoherence effects. These decoherence effects change the expectation value of the Bell operator, and gradually restore the Bell inequality. We describe this process by a “Bell test curve”, which offers a window around 5 e-folds for testing the quantum origin of cosmological perturbations. We also explore the possibility of extracting the information of the decoherence rate and the structure of primordial interactions from the Bell test curve.
Implications of in-ice volume scattering for radio-frequency neutrino experiments
Authors: Nozdrina A. , Besson D.
Published: October 2024

Over the last three decades, several experimental initiatives have been launched with the goal of observing radio-frequency signals produced by ultra-high energy neutrinos (UHEN) interacting in solid media. Observed neutrino event signatures comprise impulsive signals with duration of order the inverse of the antenna+system bandwidth (∼10 ns), superimposed upon an incoherent (typically white noise) thermal noise spectrum. Whereas bulk volume scattering (VS) of radio-frequency (RF) signals is well-studied within the radio-glaciological communities, polar ice-based neutrino-detection experiments have thus far neglected VS in their signal projections. As discussed herein, coherent volume scattering (CVS, for which the phase of the incident signal is preserved during scattering) generated by in-ice neutrino interactions may similarly produce short-duration signal-like power, albeit with a slightly extended time structure, and thereby enhance neutrino detection rates, whereas incoherent (randomized phase) volume scattering (IVS) will persist for O(100 ns), appearing similar to thermal white noise and therefore reducing the measured Signal-to-Noise Ratio (SNR) of neutrino signals. Herein, we present the expected voltage profiles resulting from in-ice volume scattering as a function of the molecular scattering cross-section, for both CVS and IVS, and assess their impact on UHEN experiments. VS contributions are currently only weakly constrained by extant data; stronger limits may be obtained with dedicated calibration experiments.
Catalog-level blinding on the bispectrum for DESI-like galaxy surveys
Authors: Novell-Masot Sergi , Gil-Marín Héctor , Verde Licia , Aguilar J. , Ahlen S. , Brieden S. , Brooks D. , Claybaugh T. , de la Macorra A. , Forero-Romero J.E. , Gaztañaga E. , Gontcho S.Gontcho A. , Gutierrez G. , Honscheid K. , Howlett C. , Kehoe R. , Kisner T. , Lambert A. , Levi M.E. , Manera M. , Meisner A. , Miquel R. , Niz G. , Prada F. , Rossi G. , Sanchez E. , Schubnell M. , Seo H. , Sprayberry D. , Tarlé G. , Weaver B.A.
Published: October 2024

We evaluate the performance of the catalog-level blind analysis technique (blinding) presented in Brieden et al. (2020) in the context of a fixed template power spectrum and bispectrum analysis. This blinding scheme, which is tailored for galaxy redshift surveys similar to the Dark Energy Spectroscopic Instrument (DESI), has two components: the so-called “AP blinding” (concerning the dilation parameters α
∥, α
⊥) and “RSD blinding” (redshift space distortions, affecting the growth rate parameter f). Through extensive testing, including checks for the RSD part in cubic boxes, the impact of AP blinding on mocks with realistic survey sky coverage, and the implementation of a full AP+RSD blinding pipeline, our analysis demonstrates the effectiveness of the technique in preserving the integrity of cosmological parameter estimation when the analysis includes the bispectrum statistic. We emphasize the critical role of sophisticated — and difficult to accidentally unblind — blinding methods in precision cosmology.
Testing the standardizability of, and deriving cosmological constraints from, a new Amati-correlated gamma-ray burst data compilation
Authors: Cao Shulei , Ratra Bharat
Published: October 2024

By using gamma-ray burst (GRB) data to simultaneously constrain Amati correlation
parameters and cosmological parameters in six spatially flat and nonflat dark energy cosmological
models, we show that an updated 220 GRB version of the Jia et al. [1] GRB data
compilation are standardizable through the Amati correlation and so can be used for cosmological
analyses. However, the resulting GRB data constraints on the current value of the nonrelativistic
matter density parameter, Ω
m

0, are in > 2σ tension with those from a joint
analysis of better-established Hubble parameter [H(z)] and baryon acoustic oscillation (BAO)
data for most of the cosmological models we consider, indicating that these GRB data cannot be
jointly used with better-established H(z) + BAO data to constrain cosmological parameters.
Ultrahigh-resolution atomic localization via superposition of standing waves
Authors: Idrees Muhammad , Hendy Ahmed S , Khan Zareen A
Published: October 2024

In this study we theoretically demonstrate ultrahigh-resolution two-dimensional atomic localization within a three-level λ-type atomic medium via superposition of asymmetric and symmetric standing wave fields. Our analysis provides an understanding of the precise spatial localization of atomic positions at the atomic level, utilizing advanced theoretical approaches and principles of quantum mechanics. The dynamical behavior of a three-level atomic system is thoroughly analyzed using the density matrix formalism within the realm of quantum mechanics. A theoretical approach is constructed to describe the interaction between the system and external fields, specifically a control field and a probe field. The absorption spectrum of the probe field is thoroughly examined to clarify the spatial localization of the atom within the proposed configuration. A theoretical investigation found that symmetric and asymmetric superposition phenomena significantly influence the localized peaks within a two-dimensional spatial domain. Specifically, the emergence of one and two sharp localized peaks was observed within a one-wavelength domain. We observed notable influences of the intensity of the control field, probe field detuning and decay rates on atomic localization. Ultimately, we have achieved an unprecedented level of ultrahigh resolution and precision in localizing an atom within an area smaller than λ/35 × λ/35. These findings hold promise for potential applications in fields such as Bose–Einstein condensation, nanolithography, laser cooling, trapping of neutral atoms and the measurement of center-of-mass wave functions.
A physical memristor model for Pavlovian associative memory
Authors: Lu 卢 Jiale 家乐 , Ran 冉 Haofeng 皓丰 , Xie 谢 Dirui 頔睿 , Zhou 周 Guangdong 广东 , Hu 胡 Xiaofang 小方
Published: October 2024

Brain-inspired intelligence is considered to be a computational model with the most promising potential to overcome the shortcomings of the von Neumann architecture, making it a current research hotspot. Due to advantages such as nonvolatility, high density, low power consumption, and high response ratio, memristors are regarded as devices with promising applications in brain-inspired intelligence. This paper proposes a physical Ag/HfO
x
/FeO
x
/Pt memristor model. The Ag/HfO
x
/FeO
x
/Pt memristor is first fabricated using magnetron sputtering, and its internal principles and characteristics are then thoroughly analyzed. Furthermore, we construct a corresponding physical memristor model which achieves a simulation accuracy of up to 99.72% for the physical memristor. We design a fully functional Pavlovian associative memory circuit, realizing functions including generalization, primary differentiation, secondary differentiation, and forgetting. Finally, the circuit is validated through PSPICE simulation and analysis.
Modeling the Covariance Matrix for the Power Spectra Before and After the BAO Reconstruction
Authors: Zhao Ruiyang , Koyama Kazuya , Wang Yuting , Zhao Gong-Bo
Published: October 2024

The baryon acoustic oscillations (BAO) reconstruction plays a crucial role in cosmological analysis for spectroscopic galaxy surveys because it can make the density field effectively more linear and more Gaussian. The combination of the power spectra before and after the BAO reconstruction helps break degeneracies among parameters, then improves the constraints on cosmological parameters. It is therefore important to estimate the covariance matrix between pre- and post-reconstructed power spectra. In this work, we use perturbation theory to estimate the covariance matrix of the related power spectra multipoles, and check the accuracy of the derived covariance model using a large suite of dark matter halo catalogs at z = 0.5. We find that the diagonal part of the auto covariance is well described by the Gaussian prediction, while the cross covariance deviates from the Gaussian prediction quickly when k > 0.1 h Mpc−1. Additionally, we find the non-Gaussian effect in the non-diagonal part of the cross covariance is comparable to, or even stronger than, the pre-reconstruction covariance. By adding the non-Gaussian contribution, we obtain good agreement between analytical and numerical covariance matrices in the non-diagonal part up to k ≃ 0.15 h Mpc−1. The agreement in the diagonal part is also improved, but still under-predicts the correlation in the cross covariance block.
Wide-angle simulated artificial vision enhances spatial navigation and object interaction in a naturalistic environment
Authors: Hinrichs Sandrine , Placidet Louise , Duret Antonin , Authié Colas , Arleo Angelo , Ghezzi Diego
Published: October 2024

Objective. Vision restoration approaches, such as prosthetics and optogenetics, provide visual perception to blind individuals in clinical settings. Yet their effectiveness in daily life remains a challenge. Stereotyped quantitative tests used in clinical trials often fail to translate into practical, everyday applications. On the one hand, assessing real-life benefits during clinical trials is complicated by environmental complexity, reproducibility issues, and safety concerns. On the other hand, predicting behavioral benefits of restorative therapies in naturalistic environments may be a crucial step before starting clinical trials to minimize patient discomfort and unmet expectations. Approach. To address this, we leverage advancements in virtual reality technology to conduct a fully immersive and ecologically valid task within a physical artificial street environment. As a case study, we assess the impact of the visual field size in simulated artificial vision for common outdoor tasks. Main results. We show that a wide visual angle (45°) enhances participants’ ability to navigate and solve tasks more effectively, safely, and efficiently. Moreover, it promotes their learning and generalization capability. Concurrently, it changes the visual exploration behavior and facilitates a more accurate mental representation of the environment. Further increasing the visual angle beyond this value does not yield significant additional improvements in most metrics. Significance. We present a methodology combining augmented reality with a naturalistic environment, enabling participants to perceive the world as patients with retinal implants would and to interact physically with it. Combining augmented reality in naturalistic environments is a valuable framework for low vision and vision restoration research.
Numerical study on the optimization of the two-way passage division pier and the energy loss in the pumping device
Authors: Lei Shuaihao , Yang Weixing , Pan Weifeng , Cheng Li
Published: October 2024

The widespread utilization of the Two-way passage pumping device (TPPD) in riverside areas notwithstanding, there exists a notable inadequacy in quantitative research pertaining to its energy and hydraulic characteristics. On the basis of division pier optimization, the entropy production theory (EPT) with computational fluid dynamics is applied to analyse the energy loss characteristic of TPPD. The results show that after the optimization of the two-way passage division pier, the flow pattern in passages is improved, the vortex structure scale in passages is obviously reduced, and the hydraulic performance is improved. The predominant cause of energy loss within TPPD stems from turbulent dissipation due to fluctuations within the impeller, leading to the formation of irregular areas with heightened entropy production (EP) along the blade surface and within the impeller channel. Moreover, the energy loss within passages is predominantly localized near the centre of the pump unit.
Study on Turbulent Taylor-Couette Flow with High Reynolds Number and Large Radius Ratio in High-Speed Canned Motor Pump Internals
Authors: Zhang Yuhan , He Xinxiang , Wu Dazhuan , Shen Yuzhe , Lu Yu , Xu Rui
Published: October 2024

The Taylor-Couette flow, a prevalent flow pattern in fluid machinery. This study investigates turbulent Taylor-Couette flow within the internal flow of a shield pump through numerical simulations. The study encompasses a range of radius ratios (0.934 to 0.977) and inner cylinder frequencies (50 to 383 Hz). Our findings reveal a significant positive correlation between torque magnitude and radius ratio within the studied parameter range. Additionally, an exponential relationship between non-dimensional torque and Taylor number was identified through fitting. Moreover, the study elucidates that larger radius ratios lead to an earlier transition to the final turbulent region with increasing Taylor numbers. Furthermore, detailed analysis of the flow field vortex structure demonstrates the profound influence of radius ratio on the number of Taylor vortices.
Hydraulic and axial force characteristics of large axial flow pumps under different flow conditions
Authors: Wang Yuqi , Cheng Li
Published: October 2024

Axial flow pumps often experience uneven distribution of axial force on the blades when deviating from design conditions, which can easily lead to local damage to the pump blades. In response to this issue, this article conducts a detailed study on the hydraulic and axial force characteristics of large vertical axial flow pumping stations in China based on constant and non-constant numerical simulation research methods. Research has found that under biased operating conditions, due to the angle between the water flow direction inside the impeller and the impeller blades, the water body collides with the blades, resulting in concentrated pressure distribution on both sides of the inlet side of the impeller blades. Under low flow conditions, the high axial force area of the impeller blade is concentrated in the middle and rear position of the suction surface, while under high flow conditions, the high axial force area is widely distributed. Under the conditions of 0.8 Q to 1.4 Q, the fluctuation of axial force on the impeller blades is mainly affected by the rotation of the impeller blades. However, under low flow conditions, due to the turbulence of the flow state, there is no obvious pattern of axial force variation on the impeller blades. In addition, under different flow conditions, there is no obvious pattern in the fluctuation of axial force on the guide vanes. This also proves that there are problems such as uneven axial force distribution and no periodic changes in the impeller blades under low flow conditions, which can easily lead to damage to the impeller blades. The above analysis can provide some reference for the design of impeller blades.
Influence of Maximum Airfoil Camber Position on Hydrofoil Cavitation Performance
Authors: Yang Chenglin , Tang Fangping
Published: October 2024

This study’s primary goal is to investigate how various airfoils’ maximum camber positions affect hydrofoil cavitation performance. Through numerical simulation, the cavitation low properties of hydrofoils with various maximum camber positions are compared. The accuracy of the modi ied turbulence viscosity and SST k-ω turbulence model on the temporal and spatial evolution characteristics of cavitation near the hydrofoil is evaluated by combining it with the model test. Analysis is done on the cavitation low ield of four airfoils at two distinct design angles of attack (+4° and +6°) with varying maximum camber locations (fmax = 35%C, 40%C, 50%C, and 60%C). The indings indicate that at 35%C, the hydrofoil’s maximum camber position has improved cavitation performance. The hydrofoil’s cloud cavitation evolution time is shorter than that of the original hydrofoil, and during the same time period, more cavitation is generated. The lift-to-drag ratio and lift coef icient of the cavitation low ield are signi icantly improved at both angles of attack. At the same time, the vorticity distribution and entropy generation distribution can be effectively reduced under the design angle of attack and high angle of attack cavitation, and the hydraulic loss in the cavitation low ield can be reduced. This research can serve as a guide for optimizing the hydrofoil’s cavitation performance and designing the impeller of the axial low pump that follows.