bluuebunny/crossref_metadata_2025 huggingface dataset:
Modifications of astrophysical ices induced by cosmic rays
Authors: Mejía C. , de Barros A. L. F. , Domaracka A. , Boduch P. , Rothard H. , da Silveira E. F.
Published: May 2024

Aims. Astrophysical ices on dust grain mantles in the interstellar medium (ISM) and dense circumstellar envelopes (CSEs) are continuously exposed to galactic cosmic rays (GCRs). In a laboratory setting, we studied the physical and chemical modifications of ice layers induced by energetic heavy ions as GCR analogues. The ice layers used have a molecular composition similar to that of icy grain mantles.

Methods. Mixtures of H2O:CO:CH3OH molecules (percentages 73:24:3, 68:30:3, and 58:38:3) were condensed on a substrate at 15 K and irradiated with 40 MeV 58Ni11+ ion beams. Irradiation-induced modifications were followed using the mid-infrared absorption spectroscopy technique.

Results. We observed the evolution of infrared bands of CO2, HCO, HCOOH, CH4, H2CO,H2O2, and more complex synthesised molecules. From the molecular column densities, cross-sections and sputtering yields were determined and compared to published results of water and carbon monoxide. Analysis of the chemical modifications reveals that the precursors are easily destroyed when they are in a molecular mixture, while others are desorbed.

Conclusions. The main radiolitic modifications induced by GCR irradiations are molecular decomposition and sputtering. Extrapolation to astrophysical radiation conditions shows a strong dependence on the intensity of the GCR distributions at low energies, which allows the analysis of the ice evolution at timescales comparable to those of the ISM and CSE.
Filament eruption by multiple reconnections
Authors: Liu Y. , Ruan G. P. , Schmieder B. , Guo J. H. , Chen Y. , Zheng R. S. , Su J. T. , Wang B.
Published: May 2024

Context. Filament eruption is a common phenomenon in solar activity, but the triggering mechanism is not well understood.

Aims. We focus our study on a filament eruption located in a complex nest of three active regions close to a coronal hole.

Methods. The filament eruption is observed at multiple wavelengths: by the Global Oscillation Network Group (GONG), the Solar Terrestrial Relations Observatory (STEREO), the Solar Upper Transition Region Imager (SUTRI), and the Atmospheric Imaging Assembly (AIA) and Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamic Observatory (SDO). Thanks to high-temporal-resolution observations, we were able to analyze the evolution of the fine structure of the filament in detail. The filament changes direction during the eruption, which is followed by a halo coronal mass ejection detected by the Large Angle Spectrometric Coronagraph (LASCO) on board the Solar and Heliospheric Observatory (SOHO). A Type III radio burst was also registered at the time of the eruption. To investigate the process of the eruption, we analyzed the magnetic topology of the filament region adopting a nonlinear force-free-field (NLFFF) extrapolation method and the polytropic global magnetohydrodynamic (MHD) modeling. We modeled the filament by embedding a twisted flux rope with the regularized Biot-Savart Laws (RBSL) method in the ambient magnetic field.

Results. The extrapolation results show that magnetic reconnection occurs in a fan-spine configuration resulting in a circular flare ribbon. The global modeling of the corona demonstrates that there was an interaction between the filament and open field lines, causing a deflection of the filament in the direction of the observed CME eruption and dimming area.

Conclusions. The modeling supports the following scenario: magnetic reconnection not only occurs with the filament itself (the flux rope) but also with the background magnetic field lines and open field lines of the coronal hole located to the east of the flux rope. This multiwavelength analysis indicates that the filament undergoes multiple magnetic reconnections on small and large scales with a drifting of the flux rope.
Jet collimation and acceleration in the flat spectrum radio quasar 1928+738
Authors: Yi Kunwoo , Park Jongho , Nakamura Masanori , Hada Kazuhiro , Trippe Sascha
Published: May 2024

Using time-resolved multifrequency Very Long Baseline Array data and new KaVA (KVN and VERA Array) observations, we study the structure and kinematics of the jet of the flat spectrum radio quasar (FSRQ) 1928+738. We find two distinct jet geometries as a function of distance from the central black hole, with the inner jet having a parabolic shape, indicating collimation, and the outer jet having a conical shape, indicating free expansion of the jet plasma. Jet component speeds display a gradual outward acceleration up to a bulk Lorentz factor Γmax ≈ 10 followed by a deceleration further downstream. The location of the acceleration zone matches the region where the jet collimation occurs. Therefore, this is the first direct observation of an acceleration and collimation zone (ACZ) in an FSRQ. The ACZ terminates approximately at a distance of 5.6 × 106 gravitational radii, which is in good agreement with the sphere of gravitational influence of the supermassive black hole, implying that the physical extent of the ACZ is controlled by the black hole gravity. Our results suggest that confinement by an external medium is responsible for the jet collimation and that the jet is accelerated by converting Poynting flux energy to kinetic energy.
Rapid optical flare in the extreme teraelectronvolt blazar 1ES 0229+200 on intraday timescales with the Transiting Exoplanet Survey Satellite
Authors: Kishore S. , Gupta A. C. , Wiita P. J. , Tiwari S. N.
Published: May 2024

Context.The extreme teraelectronvolt (TeV) blazar 1ES 0229+200 is a high-frequency-peaked BL Lacertae object. It has not shown intraday variability in extensive optical and X-ray observations, nor has it shown any significant variability on any measurable timescale in the 1–100 GeV energy range over a 14-year span; however, variations in the source flux around its average are present in the energy range above 200 GeV.

Aims.We aim to search for intraday optical variability in 1ES 0229+200 as part of an ongoing project to search for variability and quasi-periodic oscillations in the high-cadence (2 min), nearly uniformly sampled optical light curves of blazars provided by the Transiting Exoplanet Survey Satellite (TESS).

Methods.1ES 0229+200 was monitored by TESS in its Sectors 42, 43, and 44. We analysed the data of all these three sectors both with the TESS-providedlightkurvesoftware and theeleanorreduction pipeline. We detected a strong, essentially symmetric flare that lasted about 6 h in Sector 42. We fitted the flare’s rising and declining phases to exponential functions. We also analysed the light curve of Sector 42 using the Lomb-Scargle periodogram (LSP) and continuous auto-regressive moving average (CARMA) methods.

Results.The optical light curve of Sector 42 of the TESS observations displayed in the present work provides the first evidence of a strong, rapid, short-lived optical flare on the intraday timescale in the TeV blazar 1ES 0229+200. The variability timescale of the flare provides the upper limit for the size of the emission region to be within (3.3 ± 0.2–8.3 ± 0.5)×1015cm. Away from the flare, the slope of the periodogram’s power spectrum is fairly typical of many blazars (α < 2), but the nominal slopes for the flaring regions are very steep (α ∼ 4.3), which may indicate that the electron distribution undergoes a sudden change. We discuss possible emission mechanisms that could explain this substantial and rapid flare.
Updated model of cosmic-ray-induced ionization in the atmosphere (CRAC:CRII_v3): Improved yield function and lookup tables
Authors: Usoskin I.G. , Kovaltsov G.A. , Mishev A.L.
Published: May 2024

Cosmic rays, including galactic cosmic rays and solar energetic particles, form the main source of ionization of the low and middle atmosphere, which is important for various chemical and physical effects in the atmosphere. Realistic models able to compute the cosmic-ray-induced ionization (CRII) are used as inputs for chemistry-climate models. One of the most commonly used atmospheric ionization models is CRAC:CRII (Cosmic-Ray Atmospheric Cascade: application to CRII) initially developed in 2004–2006 (version 1) and significantly improved in 2010–2011 (version 2). Here, a new updated version 3 of the CRAC:CRII model is presented which offers a higher accuracy for the middle-upper atmosphere and lower-energy cosmic rays. This is particularly important for studies of the atmospheric effects of solar particle storms. Detailed lookup tables of the ionization yield function are provided for the primary cosmic ray protons and α-particles (the latter representing also heavier cosmic-ray species) along with a practical recipe for their numerical use.
Abdominal Wall Reconstruction in Abdominal Wall Endometriosis: A Case Report and Literature Review
Authors: van Varsseveld Otis C. , Koeijers Gustavo G. , Rodriguez Vitoria Juan M. , Gomes Bravio Igor
Published: May 2024

Abdominal wall endometriosis (AWE) is a rare condition representing 1% of patients operated for endometriosis. We describe a case of a 26-year-old woman, with a history of cesarean delivery, who presented with cyclical pain and a subcutaneous mass in the lower abdomen. Where most AWE lesions may be surgically managed by a single surgeon, imaging revealed an unusually large lesion (13x4x10cm) involving the rectus abdominis muscle. Plastic, gynecologic and general surgeons combined their expertise to conduct AWE excision combined with mini-abdominoplasty in a single procedure. After resection, a retrorectus mesh (Rives-Stoppa technique) reinforced the primarily closed posterior rectus sheath and an inlay mesh bridged the defect left in the anterior rectus sheath. The patient was discharged three days postoperatively, had minimal pain complaints and was satisfied with cosmetic results at one-month follow up. One year postoperatively, she gave uncomplicated vaginal birth. We conclude that, in select cases, management of a large, symptomatic AWE may benefit from a multidisciplinary approach, where symptom relief and an aesthetically pleasing result for the patient can be achieved in a single procedure. We distinctively describe double mesh repair as a viable consideration for reconstruction in AWE and review current considerations in mesh repair of the abdominal wall. Further studies into this topic are warranted.
Inflammatory biomarkers are correlated with thrombus burden in cerebral venous sinus thrombosis
Authors: Yaman Kula Aslı , Kurtoğlu Ahmet Volkan , Güzel Vildan , Balsak Serdar , Yabacı Tak Ayşegül , Asil Talip
Published: May 2024

Background Increasing evidence suggests that inflammatory biomarkers play a significant role in cerebral venous sinus thrombosis (CVST). The neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and monocyte-to-lymphocyte ratio (MLR) are related to thrombotic conditions and indicators of systemic inflammation.

Objective To analyze the correlation between inflammatory biomarkers and the extent of thrombus, determined by the CVST-Score.

Methods A total of 40 patients with CVST (24 female subjects; 60%) and 40 age- and sex-matched healthy controls were retrospectively evaluated. Inflammatory biomarkers, including C-reactive protein (CRP), PLR, NLR, MLR, and the CVST-Score, were recorded to assess the relationship between biomarkers and thrombus burden. The patients were grouped according to symptom duration (group 1: 0–3 days; group 2: 4–7 days; and group 3: 8–30 days) to compare biomarker levels.

Results The CRP, NLR, and PLR were significantly higher in the CVST group (p < 0.001; p = 0.003; p = 0.014 respectively). The NLR and PLR presented a significant positive correlation with the CVST-Score (p = 0.003, r = 0.464; p = 0.040, r = 0.326 respectively). The NLR was significantly higher in group 1 compared with groups 2 and 3 (p = 0.016 and p = 0.014 respectively). In group 1, there was a stronger positive correlation between the CVST-Score and the NLR (p = 0.026, r = 0.591) and the PLR (p = 0.012, r = 0.648). The multiple linear regression analysis revealed that the NLR is a key factor in predicting the CVST-Score (p = 0.019).

Conclusion The NLR and PLR are associated with thrombus burden in CVST, especially in patients admitted to the hospital in the early stages. The NLR is an independent factor to predict the thrombus burden in CVST.
Linking crises: inter-crisis learning and the European Commission’s approach to the National Recovery and Resilience Plans
Authors: Angelou Angelos
Published: May 2024

The article examines potential linkages between the management of the Eurozone crisis and the EU’s economic response to the COVID-19 pandemic. It does so by focusing on the Commission and its approach to conditionality-based lending. The analysis employs the concept of inter-crisis learning to argue that the lessons the Commission drew from the Eurozone crisis informed its conditionality-related proposals for the National Recovery and Resilience Plans (NRRPs). By using qualitative data, including eight elite interviews, the article suggests that the Commission derived lessons regarding the design, negotiation, implementation, and monitoring of conditionality programs. These lessons led to cognitive changes within the organisation and to behavioral changes that were reflected in its proposals regarding the conditionality attached to NRRPs. The article contributes to the literature examining the EU’s economic response to the pandemic by discussing the Commission’s drivers and preferences during that period. It also complements the literature on coordinative Europeanisation by offering insights on how the European Commission shapes its proposals on conditionality-based lending; a central element of its relationship with member states when it comes to crisis management. Finally, it discusses the implications of the article’s main thesis for the process of European integration.
Homotopy of periodic 2 × 2 matrices
Authors: Avron Joseph E. , Turner Ari M.
Published: May 2024

We describe the homotopy classes of loops in the space of 2 × 2 simple (=non-degenerate) matrices with various symmetries. This turns out to be an elementary exercise in the homotopy of closed curves in R3/{0}. Since closed curves in R3/{0} can be readily visualized, no advanced tools of algebraic topology are needed. The matrices represent gapped Bloch Hamiltonians in 1D with a two dimensional Hilbert space per unit cell.
Long-range superconducting proximity effect in YBa2Cu3O7/La0.7Ca0.3MnO3 weak-link arrays
Authors: Sanchez-Manzano D. , Mesoraca S. , Rodriguez-Corvillo S. , Lagarrigue A. , Gallego F. , Cuellar F. A. , Sander A. , Rivera-Calzada A. , Valencia S. , Villegas J. E. , Leon C. , Santamaria J.
Published: May 2024

The interplay between ferromagnetism and superconductivity has attracted substantial interest due to its potential for exotic quantum phenomena and advanced electronic devices. Although ferromagnetism and superconductivity are antagonistic phenomena, ferromagnets (F) can host spin-triplet superconductivity induced via proximity with superconductors (S). To date, most of the experimental effort has been focused on single S/F/S junctions. Here, we have found the fingerprints of long-range superconducting proximity effect in micrometric weak-link arrays, formed by embedding YBa2Cu3O7 superconducting islands in a half-metallic ferromagnet La0.7Ca0.3MnO3 film. These arrays show magnetoresistance oscillations that appear at temperatures below the critical temperature of YBa2Cu3O7 for currents below a threshold, indicating their superconducting origin. This realization paves the way for device architectures displaying macroscopic quantum interference effects, which are of interest for field sensing applications, among others.
Electronic energy transfer in molecular wire: Coherences in the presence of anharmonicity
Authors: Sindhu Aarti , Jain Amber
Published: May 2024

Electronic energy transfer in molecular wires is usually theoretically investigated with a harmonic bath to model the environment. The present study is a continuation of our previous work [A. Sindhu and A. Jain, Chem. Phys. Chem. 23, e2022003 (2022)] on studying the dynamics of molecular wires using surface hopping simulations. We extend our study to a 7-site model Hamiltonian and investigate the effects of an anharmonic bath on coherent energy transfer in molecular wires. We show that oscillatory and coherent population dynamics remain intact even in the presence of the anharmonic bath and further highlight the multiple channels available for energy flow in molecular wires.
Bexcitonics: Quasiparticle approach to open quantum dynamics
Authors: Chen Xinxian , Franco Ignacio
Published: May 2024

We develop a quasiparticle approach to capture the dynamics of open quantum systems coupled to bosonic thermal baths of arbitrary complexity based on the Hierarchical Equations of Motion (HEOM). This is done by generalizing the HEOM dynamics and mapping it into that of the system in interaction with a few bosonic fictitious quasiparticles that we call bexcitons. Bexcitons arise from a decomposition of the bath correlation function into discrete features. Specifically, bexciton creation and annihilation couple the auxiliary density matrices in the HEOM. The approach provides a systematic strategy to construct exact quantum master equations that include the system–bath coupling to all orders even for non-Markovian environments. Specifically, by introducing different metrics and representations for the bexcitons it is possible to straightforwardly generate different variants of the HEOM, demonstrating that all these variants share a common underlying quasiparticle picture. Bexcitonic properties, while unphysical, offer a coarse-grained view of the correlated system–bath dynamics and its numerical convergence. For instance, we use it to analyze the instability of the HEOM when the bath is composed of underdamped oscillators and show that it leads to the creation of highly excited bexcitons. The bexcitonic picture can also be used to develop more efficient approaches to propagate the HEOM. As an example, we use the particle-like nature of the bexcitons to introduce mode-combination of bexcitons in both number and coordinate representation that uses the multi-configuration time-dependent Hartree to efficiently propagate the HEOM dynamics.
Reverse distribution of self-driven photocurrent response hotspots in layer-dependent MoS2 devices
Authors: Yuan Youneng , Xin Rui , Huang Zhengdong , Huang Zhaoyang , Xia Hui , Li Tianxin
Published: May 2024

In van der Waals materials, the electronic property, including the bandgap as well as the charge carrier mobility and lifetime, significantly changes as its thickness shrinks to the monolayer limit. While such characteristic brings additional freedom and convenience in regard to device design and fabrication, it also raises uncertainty in terms of the semiconductor device functionality due to the competing roles of those factors in tuning the charge carrier transport. In this work, we perform scanning photocurrent microscopy experiments on different sets of MoS2 homojunctions under zero bias voltage and show the reverse photocurrent distribution among them. Specifically, in the combination of 1L–3L MoS2, the band offset is large and thus dominates the photocarrier separation. In the combination of 3L–7L MoS2, by contrast, the effect of band offset is negligible, and the mismatch in minority carrier diffusion length takes charge of the photoresponse. The authors hope that the findings presented here offer a perspective on the current transport and thus functionality realization in layered materials.
ANNaMo: Coarse-grained modeling for folding and assembly of RNA and DNA systems
Authors: Tosti Guerra F. , Poppleton E. , Šulc P. , Rovigatti L.
Published: May 2024

The folding of RNA and DNA strands plays crucial roles in biological systems and bionanotechnology. However, studying these processes with high-resolution numerical models is beyond current computational capabilities due to the timescales and system sizes involved. In this article, we present a new coarse-grained model for investigating the folding dynamics of nucleic acids. Our model represents three nucleotides with a patchy particle and is parameterized using well-established nearest-neighbor models. Thanks to the reduction of degrees of freedom and to a bond-swapping mechanism, our model allows for simulations at timescales and length scales that are currently inaccessible to more detailed models. To validate the performance of our model, we conducted extensive simulations of various systems: We examined the thermodynamics of DNA hairpins, capturing their stability and structural transitions, the folding of an MMTV pseudoknot, which is a complex RNA structure involved in viral replication, and also explored the folding of an RNA tile containing a k-type pseudoknot. Finally, we evaluated the performance of the new model in reproducing the melting temperatures of oligomers and the dependence on the toehold length of the displacement rate in toehold-mediated displacement processes, a key reaction used in molecular computing. All in all, the successful reproduction of experimental data and favorable comparisons with existing coarse-grained models validate the effectiveness of the new model.
Using a multistate mapping approach to surface hopping to predict the ultrafast electron diffraction signal of gas-phase cyclobutanone
Authors: Hutton Lewis , Moreno Carrascosa Andrés , Prentice Andrew W. , Simmermacher Mats , Runeson Johan E. , Paterson Martin J. , Kirrander Adam
Published: May 2024

Using the recently developed multistate mapping approach to surface hopping (multistate MASH) method combined with SA(3)-CASSCF(12,12)/aug-cc-pVDZ electronic structure calculations, the gas-phase isotropic ultrafast electron diffraction (UED) of cyclobutanone is predicted and analyzed. After excitation into the n-3s Rydberg state (S2), cyclobutanone can relax through two S2/S1 conical intersections, one characterized by compression of the CO bond and the other by dissociation of the α–CC bond. Subsequent transfer into the ground state (S0) is then achieved via two additional S1/S0 conical intersections that lead to three reaction pathways: α ring-opening, ethene/ketene production, and CO liberation. The isotropic gas-phase UED signal is predicted from the multistate MASH simulations, allowing for a direct comparison to the experimental data. This work, which is a contribution to the cyclobutanone prediction challenge, facilitates the identification of the main photoproducts in the UED signal and thereby emphasizes the importance of dynamics simulations for the interpretation of ultrafast experiments.
Study on dark current suppression of HgCdTe avalanche photodiodes for low flux photon detection
Authors: Xie Hao , Guo Huijun , Shen Chuan , Yang Liao , Chen Lu , He Li
Published: May 2024

Mid-wavelength infrared HgCdTe electron-initiated avalanche photodiodes (e-APDs) have presented excellent performances on resolving and counting photons. Aiming at low flux, the readout integrated circuit noise can be significantly reduced by certain device gain, and very low excess noise of HgCdTe e-APDs gives the opportunity for noise equivalent photon (NEPh) to be 1. Therefore, the main issue for signal-to-noise ratio of HgCdTe APD is gain normalized dark current density (GNDCD) at high reverse bias. In this work, the electric field distribution is optimized by designing the mesa device structure to suppress the tunneling current at high operating voltage. Furthermore, etching technology combining dry etching and wet etching and passivation technology based on plasma enhanced atomic layer deposition were used to reduce surface leakage current. Finally, 20 μm pitch 128 × 128 array HgCdTe APDs for cutoff wavelength 4.32 μm at 80 K corresponding to compositions xCd = 0.326 were fabricated, the measured GNDCD of the test unit is about 1.5–10 × 10−9 A/cm2 at 0–13 V, and very low excess noise guaranteed the NEPh to be 2.0 at gain = 93 and 1.6 at gain = 193.
The effect of surface orientation on band alignment and carrier transfer at WS2/CdS interface: Insight from first-principles calculations
Authors: Cheng Kai , Wu Peng , Hu Wenbo , Wu Lifan , Guo Xu , Guo Sandong , Su Yan
Published: May 2024

Loading of WS2 can greatly improve water splitting H2 generation efficiency of CdS in experiments. Here, we constructed WS2/CdS(100) and WS2/CdS(110) heterostructures with smaller mismatches and explored their interaction energy and band offset by first-principles calculations. Our calculation suggests that the WS2/CdS(100) interface with a stronger binding energy is more active in experiments, while the WS2/CdS(110) interface is metastable. The band alignment between CdS and WS2 is highly dependent on the orientation of the interfaces, and WS2/CdS(100) and WS2/CdS(110) belong to type-I and type-II band alignments, respectively. Therefore, a metal electrode and hole scavenger may be essential in experiments to help WS2/CdS(100) efficiently trap electrons, and a suitable substrate and an appropriate growth temperature are also needed to composite the CdS(110) surface to achieve a higher photocatalytic efficiency. In addition, we performed a detailed analysis of the macroscopic average potential and found that the calculated accuracy of potential difference across the heterostructures due to slab thickness is less than 80 meV at WS2/CdS interfaces. In total, our calculations not only explain the physical reasons for the increased efficiency of WS2/CdS, but also provide a detailed guideline for the design of a more efficient synergistic catalyst.
Controllable magnon Hanle effect in easy-plane antiferromagnets
Authors: Su Yichen , Huang Lin , Pan Feng , Song Cheng
Published: May 2024

Magnon Hanle effect in easy-plane antiferromagnets allows us to obtain different output spin states without switching the Néel vector, which opens up a different path for the construction of future magnonic devices. This effect originates from the precession of the pseudospin and is sensitive to the basic magnetic parameters, such as magnetic anisotropy, so that a precise control of magnon Hanle effect is needed. Here, we manipulate the magnon Hanle effect in easy-plane antiferromagnetic α-Fe2O3 with different film thicknesses and the resultant different strain and easy-plane anisotropy. The Hanle peak shifts to the lower magnetic field when the film thickness increase is associated with decreasing easy-plane anisotropy. The anisotropy–thickness relationship can be attributed to the strain relaxation by interfacial dislocations, which varies with film thickness. Our finding builds a bridge between magnon transport and material microstructures and provides a different perspective for the control of magnon Hanle effect and future magnonic devices.
Human resource management practices on Irish dairy farms: an exploratory study
Authors: Lawton Thomas , Gorman Monica , Beecher Marion
Published: May 2024

Context Managing people outside the farm family unit is a new issue for many Irish dairy farmers. In the context of rapid growth, the demand for employees has increased, creating the need for Irish dairy farmers to have human resource management (HRM) skills. Aims This paper explores the extent and type of HRM practices adopted by Irish dairy farmers and the factors that influence their adoption. Methods A questionnaire was developed, piloted, and issued to farmers on the basis of herd size and location. Data from 203 dairy farmers who employ people were analysed to examine the adoption of different HRM practices and the influence of farm characteristics, farmer demographics and farmer attitudes on their adoption. HRM practices included compliance with employment legislation, health and safety, different approaches to recruitment, workforce management and retention. The questionnaire included one or more variables for each of these HRM practices. Where more than one variable was included, an aggregate variable was developed for that practice. Key results Whereas, overall, there was a low level of adoption of best HRM practices, farm characteristics such as herd size and number of employees had a significant influence on farmers’ adoption of compliance with employment legislation, health and safety, recruitment, workforce management and retention practices. Demographic factors such as age, level of education, and average hours worked influenced farmers compliance with employment law legislation, workforce management practices and retention practices. Conclusions The study highlighted an overall low compliance with employment legislation and low adoption of best practices in managing staff among dairy farmers in Ireland. Implications This study highlighted that improvement is needed in all areas of HRM on Irish dairy farms. The findings of this study would be useful to farm advisors who support dairy farmers in improving their management of their businesses. Overall, this study has contributed to a greater understanding of the challenges in managing people in agriculture and how certain factors influences the adoption of HRM practices on dairy farms.
Accumulation of organic carbon was limited to the surface of a duplex soil in the mixed farming zone of south-eastern Australia
Authors: Conyers Mark K. , Li Guangdi D. , Poile Graeme J. , Oates Albert , Helyar Keith R. , Rohan Maheswaran
Published: May 2024

Context The goal of increasing sequestration of carbon (C) in soil assumes that management factors can be as influential as intrinsic factors such as climate and parent material. Aim The hypotheses tested in this study were (i) that soil C would increase more in limed than in unlimed pasture treatments, and (ii) that well-managed perennial pasture treatments would accumulate soil C to a greater depth than annual pasture treatments. Method An 18-year field experiment was conducted on a duplex soil in the mixed farming zone of south-eastern Australia. The experiment contained four treatment contrasts: limed and unlimed perennial and annual pasture systems. Soils samples to 120 cm were taken annually and analysed for C and nitrogen (N) concentrations. Soil C and N stocks were calculated. Key results The four treatments produced a similar annual rate of increase in soil C concentration and C stocks. The increase in C stock was confined to the surface 30 cm of soil in all four treatments, leading to the rejection of both hypotheses. Nitrogen concentration and N stocks to 30 cm depth increased significantly over the 18 years, with no difference among treatments. Conclusion Pasture land use increased soil C storage by ~700 kg ha−1 year−1; however, the increase was confined to the surface soil. Implication The soil C sequestered in this duplex soil is vulnerable to erosion. The co-retained N might have more value from both production and environmental perspectives.
High night temperature stress on rice (Oryza sativa) – insights from phenomics to physiology. A review
Authors: Riaz Awais , Thomas Julie , Ali Hafiz Haider , Zaheer Muhammad Saqlain , Ahmad Naushad , Pereira Andy
Published: May 2024

Rice (Oryza sativa) faces challenges to yield and quality due to urbanisation, deforestation and climate change, which has exacerbated high night temperature (HNT). This review explores the impacts of HNT on the physiological, molecular and agronomic aspects of rice growth. Rise in minimum temperature threatens a potential 41% reduction in rice yield by 2100. HNT disrupts rice growth stages, causing reduced seed germination, biomass, spikelet sterility and poor grain development. Recent findings indicate a 4.4% yield decline for every 1°C increase beyond 27°C, with japonica ecotypes exhibiting higher sensitivity than indica. We examine the relationships between elevated CO2, nitrogen regimes and HNT, showing that the complexity of balancing positive CO2 effects on biomass with HNT challenges. Nitrogen enrichment proves crucial during the vegetative stage but causes disruption to reproductive stages, affecting grain yield and starch synthesis. Additionally, we elucidate the impact of HNT on plant respiration, emphasising mitochondrial respiration, photorespiration and antioxidant responses. Genomic techniques, including CRISPR-Cas9, offer potential for manipulating genes for HNT tolerance. Plant hormones and carbohydrate enzymatic activities are explored, revealing their intricate roles in spikelet fertility, grain size and starch metabolism under HNT. Gaps in understanding genetic factors influencing heat tolerance and potential trade-offs associated with hormone applications remain. The importance of interdisciplinary collaboration is needed to provide a holistic approach. Research priorities include the study of regulatory mechanisms, post-anthesis effects, cumulative HNT exposure and the interaction between climate variability and HNT impact to provide a research direction to enhance rice resilience in a changing climate.
In vivo whole-cortex marker of excitation-inhibition ratio indexes cortical maturation and cognitive ability in youth
Authors: Zhang Shaoshi , Larsen Bart , Sydnor Valerie J. , Zeng Tianchu , An Lijun , Yan Xiaoxuan , Kong Ru , Kong Xiaolu , Gur Ruben C. , Gur Raquel E. , Moore Tyler M. , Wolf Daniel H. , Holmes Avram J. , Xie Yapei , Zhou Juan Helen , Fortier Marielle V. , Tan Ai Peng , Gluckman Peter , Chong Yap Seng , Meaney Michael J. , Deco Gustavo , Satterthwaite Theodore D. , Yeo B. T. Thomas
Published: May 2024

A balanced excitation-inhibition ratio (E/I ratio) is critical for healthy brain function. Normative development of cortex-wide E/I ratio remains unknown. Here, we noninvasively estimate a putative marker of whole-cortex E/I ratio by fitting a large-scale biophysically plausible circuit model to resting-state functional MRI (fMRI) data. We first confirm that our model generates realistic brain dynamics in the Human Connectome Project. Next, we show that the estimated E/I ratio marker is sensitive to the gamma-aminobutyric acid (GABA) agonist benzodiazepine alprazolam during fMRI. Alprazolam-induced E/I changes are spatially consistent with positron emission tomography measurement of benzodiazepine receptor density. We then investigate the relationship between the E/I ratio marker and neurodevelopment. We find that the E/I ratio marker declines heterogeneously across the cerebral cortex during youth, with the greatest reduction occurring in sensorimotor systems relative to association systems. Importantly, among children with the same chronological age, a lower E/I ratio marker (especially in the association cortex) is linked to better cognitive performance. This result is replicated across North American (8.2 to 23.0 y old) and Asian (7.2 to 7.9 y old) cohorts, suggesting that a more mature E/I ratio indexes improved cognition during normative development. Overall, our findings open the door to studying how disrupted E/I trajectories may lead to cognitive dysfunction in psychopathology that emerges during youth.
Word segmentation granularity in Korean
Authors: Park Jungyeul , Kim Mija
Published: May 2024

This paper describes word segmentation granularity in Korean language processing. From a word separated by blank
space, which is termed an eojeol, to a sequence of morphemes in Korean, there are multiple possible levels of word segmentation
granularity in Korean. For specific language processing and corpus annotation tasks, several different granularity levels have
been proposed and utilized, because the agglutinative languages including Korean language have a one-to-one mapping between
functional morpheme and syntactic category. Thus, we analyze these different granularity levels, presenting the examples of Korean
language processing systems for future reference. Interestingly, the granularity by separating only functional morphemes including
case markers and verbal endings, and keeping other suffixes for morphological derivation results in the optimal performance for
phrase structure parsing. This contradicts previous best practices for Korean language processing, which has been the de facto
standard for various applications that require separating all morphemes.
Analytical model and precise evaluation of multi-layer magnetic shielding performances considering ultra-weak magnetic properties
Authors: Xu Xueping , Wu Weiwei , Zhao Zhenkai , Liu Wei , Sun Jinji
Published: May 2024

Regarding the vast difference between the design index and the actual performance of magnetic shielding devices, this paper proposes a novel method of using precise permeability under a specific weak magnetic field, aiming to improve the design accuracy of shielding performance. Firstly, the relative permeability of the permalloy is measured under the applied magnetic field from the geomagnetic field down to 1 nT. Next, the precise shielding coefficient formulas of the single- and double-layer spherical shells are derived. For the double-layer spherical shells, the deviation of remanence between considering the ultra-weak magnetic properties and using the constant permeability is 24.3%. This clarifies the necessity of considering the ultra-weak magnetic properties in multi-layer structures. Then, a new accurate method of the shielding coefficient for the finite-length magnetic shielding cylinder is proposed, with a deviation of less than 5%. Finally, this method has been validated again by remanence measurement of the three-layer magnetic shielding cylinders. The deviation between simulation and experiment is 4.03% when considering the ultra-weak magnetic properties. While using the constant permeability, the deviation is as high as 19.31%. Therefore, considering the ultra-weak magnetic properties in multi-layer structures can significantly improve the accuracy of the performance evaluation.
Fault identification of centrifugal pump using WGAN-GP method with unbalanced datasets based on kinematics simulation and experimental case
Authors: Li Qing , Chu Liying , Sun Qiang , Tang Yanning , Zhang Yaping
Published: May 2024

In practical engineering applications, the accuracy and stability of fault identification for centrifugal pump will be significantly reduced due to unbalanced distribution between normal and fault datasets, i.e., the number of normal working samples is far more than the fault samples. To alleviate this bottleneck issue, this paper explores the fault identification of centrifugal pump based on Wasserstein generative adversarial network with gradient penalty (WGAN-GP) through combining kinematics simulation and experimental case. Specifically, ideal unbalanced vibration datasets from failure patterns such as damaged impeller of centrifugal pump are simulated and collected by prototype ADAMS software, then the unbalanced vibration signals are transformed into 2D grey-scale images. Furtherly, the generated grey-scale image datasets are feed into the original grey-scale image dataset as new datasets for training when the Nash equilibrium of the WGAN-GP model is reached. Eventually, the fault patterns of centrifugal pump are identified using confusion matrix graph. Meanwhile, another public dataset of centrifugal pump is employed for verifying the accuracy of the WGAN-GP model. Results indicate that fault identification accuracies with 95.07% and 98.0% of both kinematics simulation and experimental case are obtained, respectively, and the issues of unbalanced distribution and insufficient dataset can be overcome effectively.
Advancements in bearing remaining useful life prediction methods: a comprehensive review
Authors: Song Liuyang , Lin Tianjiao , Jin Ye , Zhao Shengkai , Li Ye , Wang Huaqing
Published: May 2024

This paper presents a comprehensive review of the state-of-the-art techniques for predicting the remaining useful life (RUL) of rolling bearings. Four key aspects of bearing RUL prediction are considered: data acquiring, construction of health indicators, development of RUL prediction algorithms, and evaluation of prediction results. Additionally, publicly available datasets that can be used to validate bearing prediction algorithms are described. The existing RUL prediction algorithms are categorized into three types and have been comprehensively reviewed: physical-based, statistical-based, and data-driven. In particular, the progress made in data-driven prediction methods is summarized, and typical methods such as rerrent neural network, convolutional network, graph convolutional network, Transformer, and transfer learning-based methods are introduced in detail. Finally, the challenges faced by data-driven methods in RUL prediction for bearings are discussed.
Nonlinear optical properties of KnCl (n = 2–7) superalkali clusters
Authors: Şentürk Şükrü , Fardad Fraidoon , Ekincioğlu Yavuz
Published: May 2024

The lowest energy structures along with the low lying isomer, stabilities, electronic properties, optical properties and nonlinear optical responses of KnCl (n = 2–7) clusters were studied within the density functional theory. The second order energy difference, dissociation energy and GH-L (HOMO–LUMO gap) point out that KnCl (n = 3, 5, 7) clusters are more stable. The calculated adiabatic ionization energies (AIE) for the KnCl (n = 2–6) clusters are in agreement with the measured ionization energies. The optical properties, namely optical electronegativity and refractive index, depends on the GH-L energy values. The K atom capped planar rhombus geometry of the K4Cl causes the noticeable vibrational frequency shift compared to the rest of IR spectra of the clusters. The first static hyperpolarizability (β
o) values are in the range of 2.33 × 103
–2.87 × 104 au and the second static hyperpolarizability varies between 5.74 × 106 au and 38.9 × 106 au for the cluster. The nonlinear optical response is due to the superalkali nature of KnCl (n = 2–7) clusters. From computed β
vec values, the hyperpolarizability has projection on the dipole moment vector for the superalkalis except the K2Cl and K5Cl. The absorption spectra point out that KnCl (n = 6–7) clusters can be suitable as a NLO material since they have transparency in the deep UV region (λ< 300 nm).
Hybrid minigrid system comprising energy storage systems with optimal frequency control empowering the new Egypt large optical telescope site
Authors: Abdelkareem Mohamed , Abdelghany A M , Azzam Yosry Ahmed , Ebrahim Mohamed Ahmed , Abdelghany M A
Published: May 2024

Proposed hybrid minigrid two area system simulation model encompassing Photo Voltaic (PV) system, Wind Turbines (WT), diesel generators and Energy Storage Systems with intelligent based optimal Frequency Controllers (FCs) empowering the new Egypt large optical telescope (ELOT) site is presented in this research. Technical study and specifications for a PV solar system of 1000 Kw is introduced. Intelligent fine optimized Proportional Integral Derivative (PID) and Fuzzy self-tuned PID (FSTPID) controllers are designed through applying Harris Hawk optimizer (HHO). The proposed HHO employed method performance is validated under number of eventualities which include vacillations of load, sun radiation and wind speed. The objective function and control parameters are the integral time summation of absolute deviations and the parameters of controllers, consecutively. The system dynamic response and simulation results show that the proposed HHO based FSTPID type FCs are effective in reducing frequency and tie line power signals’ deviations in a diminutive time for such minigrid hybrid system. For supplemental validations, simulation results obtained are compared with genetic algorithm to get the proposed controllers’ gains.
One-dimensional quantum scattering from multiple Dirac δ − potentials: a Python-based solution
Authors: Keshavarz Erfan , Mazharimousavi S Habib
Published: May 2024

In this research, we present a Python-based solution designed to simulate a one-dimensional quantum system that incorporates multiple Dirac δ − potentials. The primary aim of this research is to investigate the scattering problem within such a system. By developing this program, we can generate wave functions throughout the system and compute transmission and reflection amplitudes analytically and numerically for an infinite range of combinations involving potential strengths, potential separations, and the number of potential centers in the form of the Dirac δ − functions. Furthermore, by modifying the code, we investigate the so-called ‘transmission resonances’ which yields the energy of the quantum particles undergoing a perfect transmission. Subsequently, our research is extended by considering impurities in the system.
A novel semi-supervised deep learning method for enhancing discriminability and diversity in EEG-based emotion recognition task
Authors: Waleed Al-Asadi Ahmed , Salehpour Pedram , Aghdasi Hadi S
Published: May 2024

Numerous deep learning models have been introduced for EEG-based Emotion recognition tasks. Nevertheless, the majority of these models are fully supervised, demanding substantial amounts of labeled EEG signals. The labeling process of EEG signals is both time-intensive and costly, involving numerous trials and meticulous analysis by experts. Recently, some advanced semi-supervised algorithms that can achieve a competitive performance with fully-supervised methods by using only a small set of labeled data have been presented. However, these algorithms are primarily developed for the image data type, and naïve adaptation of them for EEG applications results in unsatisfactory performance. To address this issue, we present a robust semi-supervised EEG-based method that exploits the best techniques from advanced semi-supervised algorithms in the computer vision domain enriched with novel regularization terms for unlabeled signals. The proposed regularization terms improve both the discriminability and diversity of the model’s predictions and effectively leverage prior knowledge about the class distributions, thereby achieving a superior performance compared to the distribution alignment techniques in state-of-the-art methods. We evaluate our method on the DEAP dataset for cross-subject valence/arousal emotion recognition tasks, and on the SEED in a cross-session setting. The results indicate that the proposed method consistently surpasses the peer methods at different numbers of labeled data by a large margin.
Friction stir additive manufactured AA 6061/TiC/GS composite: assessment of microstructural and mechanical properties
Authors: Maurya Manish , Kumar Sudhir , Maurya Ambrish
Published: May 2024

Friction stir additive manufacturing (FSAM) technique was used to fabricate the composite. Present investigation deals with the additive manufacturing of three AA 6061 sheets filled with TiC/GS particles in a groove with the variation reinforcement wt-%. Micro-structural investigation of the fabricated sample was conducted through optical microscopy, SEM and EDS. Optical and SEM results depict the uniform dispersal of the TiC and GS particles in the processed zone. Due to hard TiC and GS particles embedded in AA 6061, an improvement in hardness by 37.2% was observed for AA 6061/4 wt-%TiC/6 wt-%GS composite. Tensile and compressive strength was enhanced by 25.8% and 11% for the developed material. Corrosion test and thermal expansion behavior was investigated for the fabricated composite. 0.2 gm was the weight loss observed for the sample kept in NaCl solution for 72 h. Negligible amount of thermal expansion was noticed for the prepared material. TiC and GS particles, observed in the fractographic image shows the brittle fracture. EDS analysis confirmed the existence of elements like Al, Mg, Mn etc in the surface of the specimens. The present experimental results were also compared from the previous published work by the various academicians.