bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling the Mg I from the NUV to MIR
Authors: Peralta J. I. , Vieytes M. C. , Mendez A. M. P. , Mitnik D. M.
Published: June 2023

Context. Reliable atomic data are mandatory ingredients to obtain a realistic semiempirical model of any stellar atmosphere. Due to their importance, we further improved our recently published Mg I atomic model.

Aims. We tested the new atomic model using atmospheric models of stars of different spectral types: the Sun (dG2), HD 22049 (dK2, Epsilon Eridani), GJ 832 (dM2), and GJ 581 (dM3).

Methods. Significant improvements have been included in the atomic model, mainly to the electron impact excitation (ϒij) values. We used new Breit-Pauli distorted-wave (DW) multiconfiguration calculations, which proved to be relevant for many transitions in the mid-infrared (MIR) range. The new atomic model of Mg I includes the following: (i) recomputed (ϒij) data through the DW method, including the superlevels. (ii) For the nonlocal thermodynamic equilibrium (NLTE) population calculations, 5676 theoretical transitions were added (3001 term-to-term). (iii) All of these improvements were studied in the Sun and the stars listed above. Comparisons for the distribution of magnesium among the first ionization states and the formation of molecules, as well as for the population of the different energy levels and atmospheric heights, were carried out. Several lines, representative of the spectral ranges, were selected to analyze the changes that were produced. In particular, we exemplify these results with the problematic line 2853.0 Å, a transition between the third level and the ground state.

Results. The magnesium distribution between ionization states for stars with different effective temperatures was compared. For the Sun and Epsilon Eridani, Mg II predominates with more than 95%, while for GJ 832 and GJ 581, Mg I represents more than 72% of the population. Moreover, in the latter stars, the amount of magnesium forming molecules in their atmosphere is at least two orders of magnitude higher. Regarding the NLTE population, a noticeable lower variability in the departure coefficients was found, indicating a better population coupling for the new model. Comparing the synthetic spectrum calculated with the older and new Mg I atomic model, these results show minimal differences in the visible range but they are stronger in the infrared (IR) for all of the stars. This aspect should be considered when using lines from this region as indicators. Nevertheless, some changes in the spectral type were found, also emphasizing the need to test the atomic models in different atmospheric conditions. The most noticeable changes occurred in the far-ultraviolet (FUV) and near-ultraviolet (NUV), obtaining a higher flux for the new atomic model regardless of the spectral type. The new model did not prevent the formation of the core emission in the synthetic NUV line 2853.0 Å. However, by including other observations, we could note that the emission indeed exists, although with a much lower intensity. Further tests have shown that to reduce the emission, the population of its upper level (3s3p 1P) should be reduced by a factor of about 100.
Quasi-periodic eruptions from impacts between the secondary and a rigidly precessing accretion disc in an extreme mass-ratio inspiral system
Authors: Franchini Alessia , Bonetti Matteo , Lupi Alessandro , Miniutti Giovanni , Bortolas Elisa , Giustini Margherita , Dotti Massimo , Sesana Alberto , Arcodia Riccardo , Ryu Taeho
Published: June 2023

X-ray quasi-periodic eruptions (QPEs) represent a recently discovered example of extreme X-ray variability associated with supermassive black holes. These are high-amplitude bursts recurring every few hours that are detected in the soft X-ray band from the nuclei of nearby galaxies whose optical spectra lack the broad emission lines typically observed in unobscured active galaxies. The physical origin of this new X-ray variability phenomenon is still unknown and several theoretical models have been presented. However, no attempt has been made so far to account for the varying QPE recurrence time and luminosity in individual sources, nor for the diversity of the QPE phenomenology in the different known erupters. We present a semi-analytical model based on an extreme mass-ratio inspiral (EMRI) system where the secondary intersects, along its orbit, a rigidly precessing accretion disc surrounding the primary. We assume that QPEs result from emission from an adiabatically expanding, initially optically thick gas cloud expelled from the disc plane at each impact. We produced synthetic X-ray light curves, which we then compared with X-ray data from four QPE sources: GSN 069, eRO-QPE1, eRO-QPE2, and RX J1301.9+2747. Our model aptly reproduces the diversity of QPE properties between the considered objects and it is also able to naturally account for the varying QPE amplitudes and recurrence times in individual sources. Future implementations will enable us to refine the match with the data and to estimate the system parameters precisely, making additional use of multi-epoch QPE data. We briefly discuss the nature of the secondary object, as well as the possible implications of our findings for the EMRI population at large.
X-ray properties of the white dwarf pulsar eRASSU J191213.9−441044
Authors: Schwope A. , Marsh T. R. , Standke A. , Pelisoli I. , Potter S. , Buckley D. , Munday J. , Dhillon V.
Published: June 2023

We report X-ray observations of the newly discovered pulsating white dwarf eRASSU J191213.9−441044 with Spectrum Roentgen Gamma and eROSITA (SRG/eROSITA) and XMM-Newton. The new source was discovered during the first eROSITA all-sky survey at a flux level of fX(0.2 − 2.3 keV) = 3.3 × 10−13 erg cm−2 s−1 and found to be spatially coincident with a G = 17.1 stellar Gaia-source at a distance of 237 pc. The flux dropped to about fX = 1 × 10−13 erg cm−2 s−1 during the three following eROSITA all-sky surveys and remained at this lower level during dedicated XMM-Newton observations performed in September 2022. With XMM-Newton, pulsations with a period of 319 s were found at X-ray and ultraviolet wavelengths occurring simultaneously in time, thus confirming the nature of eRASSU J191213.9−441044 as the second white-dwarf pulsar. The X-ray and UV-pulses correspond to broad optical pulses. Narrow optical pulses that occurred occasionally during simultaneous XMM-Newton/ULTRACAM observations have no X-ray counterpart. The orbital variability of the X-ray signal with a roughly sinusoidal shape was observed with a pulsed fraction of ∼28% and maximum emission at orbital phase ∼0.25. The ultraviolet light curve peaks at around binary phase 0.45. The X-ray spectrum can be described with the sum of a power law spectrum and a thermal component with a mean X-ray luminosity of LX(0.2 − 10 keV) = 1.4 × 1030 erg s−1. The spectral and variability properties could indicate some residual accretion, in contrast to the case of the prototypical object AR Sco.
Ketogenic Diet in Neonates with Drug-Resistant Epilepsy: Efficacy and Side Effects—A Single Center's Initial Experience
Authors: Falsaperla Raffaele , Sortino Vincenzo , Collotta Ausilia Desiree , Privitera Grete Francesca , Palmeri Antonio , Mauceri Laura , Ruggieri Martino
Published: June 2023

Background For patients with pharmacoresistant epilepsy, a therapeutic option is ketogenic diet. Currently, data on young infants are scarce, particularly during hospitalization in the neonatal intensive care unit (NICU).

Objective The aim of the present study was to evaluate the short-term (3-month) efficacy and side effects of ketogenic diet in infants with “drugs-resistant” epilepsy treated during NICU stay.

Methods This retrospective study included infants aged under 2 months started on ketogenic diet during NICU hospitalization to treat drug-resistant epilepsy from April 2018 to November 2022.

Results Thirteen term-born infants were included, three (23.1%) of whom were excluded because they did not respond to the ketogenic diet. Finally, we included 10 infants. Six (60%) patients took three antiepileptics before starting the ketogenic diet, while four (40%) took more drugs. Diet had a good response in four (40%) patients. In four patients, the ketogenic diet was suspended because of the onset of serious side effects. The emetic levels of sodium, potassium, and chlorine, pH, and onset of diarrhea, constipation, and gastroesophageal reflux showed significant differences. Ketonuria was higher and blood pH lower in the group that took more than three drugs than in the group taking fewer than three drugs.

Conclusion The ketogenic diet is efficacious and safe in infants, but the early and aggressive management of adverse reactions is important to improve the safety and effectiveness of the ketogenic treatment.
Expert Review on Spontaneous Pneumothorax: Advances, Controversies, and New Directions
Authors: Barton Eleanor C. , Maskell Nick A. , Walker Steven P.
Published: June 2023

For decades, there has been scanty evidence, most of which is of poor quality, to guide clinicians in the assessment and management of pneumothorax. A recent surge in pneumothorax research has begun to address controversies surrounding the topic and change the face of pneumothorax management. In this article, we review controversies concerning the etiology, pathogenesis, and classification of pneumothorax, and discuss recent advances in its management, including conservative and ambulatory management. We review the evidence base for the challenges of managing pneumothorax, including persistent air leak, and suggest new directions for future research that can help provide patient-centered, evidence-based management for this challenging cohort of patients.
Factors Influencing Anti-Xa Assays: A Multicenter Prospective Study in Critically Ill and Noncritically Ill Patients Receiving Unfractionated Heparin
Authors: Lasne Dominique , Toussaint-Hacquard Marie , Delassasseigne Céline , Bauters Anne , Flaujac Claire , Savard Philippe , Mouton Christine , De Maistre Emmanuel , Stepanian Alain , Eschwège Valérie , Delrue Maxime , Georges Jean-Louis , Gros Antoine , Mansour Alexandre , Leroy Guillaume , Jouffroy Romain , Mattei Matthieu , Beurton Antoine , Pontis Adeline , Neuwirth Marie , Nedelec-Gac Fabienne , Lecompte Thomas , Curis Emmanuel , Siguret Virginie , Gouin-Thibault Isabelle
Published: June 2023

Background The presence of dextran sulfate (DS) in reagents and the type of blood collection tube (citrate/citrated-theophylline-adenosine-dipyridamole [CTAD]) can lead to discrepancies between unfractionated heparin (UFH) anti-Xa levels.

Objectives To evaluate the extent of the effect (1) of different reagents containing or not containing DS and (2) of the blood collection tubes, on UFH anti-Xa levels, in various clinical situations (NCT04700670).

Methods We prospectively included patients from eight centers: group (G)1, cardiopulmonary bypass (CPB) after heparin neutralization (n = 39); G2, cardiothoracic intensive care unit (ICU) after CPB (n = 35); G3, medical ICU (n = 53); G4, other medical inpatients (n = 38). Blood was collected into citrated and CTAD tubes. Chromogenic anti-Xa assays were centrally performed, using seven reagent/analyzer combinations including two without DS. The association between anti-Xa levels and covariates was tested using a linear mixed-effects model.

Results We analyzed 4,546 anti-Xa values from 165 patients. Median anti-Xa levels were systematically higher with reagents containing DS, whatever the patient group, with the greatest effect observed in G1 (0.32 vs. 0.05 IU/mL). Anti-Xa levels were slightly higher in CTAD than in citrate samples, irrespective of the assay. The model showed: (1) a significant dextran–patient group interaction (p < 0.0001), the effect of DS on anti-Xa levels varying from 30.9% in G4 to 296% in G1, and (2) a significant effect of CTAD, varying between patient groups (p = 0.0302).

Conclusion The variability of anti-Xa levels with a great overestimation of the values, using a reagent containing DS, can lead to different treatment decisions, especially after heparin neutralization by protamine. Clinical consequences of these differences remain to be demonstrated.
Exploring weak spots in cutting-edge lithography for microchip manufacturing
Authors: Ikenson Ben
Published: June 2023

Integrated circuit pattern anomalies may stem from the same stochastic phenomenon
Hybrid material Gradia-HZ exhibits tunable semiconducting and metallic properties
Authors: Liebendorfer Adam
Published: June 2023

Simulations demonstrate the graphite-diamond hybrid’s versatility, transitioning from semimetal to semiconductor and metal, with carrier mobility matching silicon.
Microfluidics based bioimaging with cost-efficient fabrication of multi-level micrometer-sized trenches
Authors: Anilkumar Anand , Batra Abhilasha , Talukder Santanu , Sharma Rati
Published: June 2023

Microfluidic devices, through their vast applicability as tools for miniaturized experimental setups, have become indispensable for cutting edge research and diagnostics. However, the high operational cost and the requirement of sophisticated equipment and clean room facility for the fabrication of these devices make their use unfeasible for many research laboratories in resource limited settings. Therefore, with the aim of increasing accessibility, in this article, we report a novel, cost-effective micro-fabrication technique for fabricating multi-layer microfluidic devices using only common wet-lab facilities, thereby significantly lowering the cost. Our proposed process-flow-design eliminates the need for a mastermold, does not require any sophisticated lithography tools, and can be executed successfully outside a clean room. In this work, we also optimized the critical steps (such as spin coating and wet etching) of our fabrication process and validated the process flow and the device by trapping and imaging Caenorhabditis elegans. The fabricated devices are effective in conducting lifetime assays and flushing out larvae, which are, in general, manually picked from Petri dishes or separated using sieves. Our technique is not only cost effective but also scalable, as it can be used to fabricate devices with multiple layers of confinements ranging from 0.6 to more than 50 μm, thus enabling the study of unicellular and multicellular organisms. This technique, therefore, has the potential to be adopted widely by many research laboratories for a variety of applications.
4D Light-sheet imaging and interactive analysis of cardiac contractility in zebrafish larvae
Authors: Zhang Xinyuan , Almasian Milad , Hassan Sohail S. , Jotheesh Rosemary , Kadam Vinay A. , Polk Austin R. , Saberigarakani Alireza , Rahat Aayan , Yuan Jie , Lee Juhyun , Carroll Kelli , Ding Yichen
Published: June 2023

Despite ongoing efforts in cardiovascular research, the acquisition of high-resolution and high-speed images for the purpose of assessing cardiac contraction remains challenging. Light-sheet fluorescence microscopy (LSFM) offers superior spatiotemporal resolution and minimal photodamage, providing an indispensable opportunity for the in vivo study of cardiac micro-structure and contractile function in zebrafish larvae. To track the myocardial architecture and contractility, we have developed an imaging strategy ranging from LSFM system construction, retrospective synchronization, single cell tracking, to user-directed virtual reality (VR) analysis. Our system enables the four-dimensional (4D) investigation of individual cardiomyocytes across the entire atrium and ventricle during multiple cardiac cycles in a zebrafish larva at the cellular resolution. To enhance the throughput of our model reconstruction and assessment, we have developed a parallel computing-assisted algorithm for 4D synchronization, resulting in a nearly tenfold enhancement of reconstruction efficiency. The machine learning-based nuclei segmentation and VR-based interaction further allow us to quantify cellular dynamics in the myocardium from end-systole to end-diastole. Collectively, our strategy facilitates noninvasive cardiac imaging and user-directed data interpretation with improved efficiency and accuracy, holding great promise to characterize functional changes and regional mechanics at the single cell level during cardiac development and regeneration.
BatMap – authoritative distribution maps for Australian bats
Authors: Milne Damian J. , Reardon Terry B. , Ford Greg
Published: June 2023

BatMap is a project that has enabled the development of spatial distribution maps for all mainland Australian and Tasmanian bat species. The distribution maps were developed by bat experts and are actively updated and maintained by utilising the collective knowledge of the members of the Australasian Bat Society. Distribution maps are the most accurate maps that are currently available for Australian bat species. The distribution maps are freely available on-line in a variety of formats. The distribution maps have been used for a variety of purposes, including the assessment of the spatial and taxonomic accuracy of bat records from ecological datasets, particularly datasets that are managed by the Atlas of Living Australia, which are considered by many to be the key source of spatial information for bats. BatMap enables better conservation outcomes for Australian bat fauna through the provision of authoritative, readily accessible and usable maps that can be used to increase the accuracy and reliability of bat records that contribute to decision making processes for conservation purposes.
GPS-derived foraging behaviour of red deer and liveweight gain of red deer and wapiti crossbred sire lines on contrasting winter forage types
Authors: Thompson B. R. , Stevens D. R. , Bennett C. , O’Neill K. T. , Miller P. , Green P. , Ward J. F.
Published: June 2023

Context It is common practice to manage red deer on highly digestible easily harvested forage during winter on New Zealand deer farms, particularly in areas that experience low or no pasture growth during this period. However, not all individuals within these production systems perform equally. Aims To investigate foraging behaviour of young red deer and liveweight gain of young red deer and wapiti crossbred sire lines when offered two contrasting winter forage diets. Methods One hundred and sixty-three rising 1-year-old female red deer and red deer wapiti crossbreds representing five red deer and two wapiti sires, were split into two management groups balanced by sire and liveweight and managed on either an easily harvested highly digestible diet (forage kale) or a harder-to-harvest more poorly digestible diet (pasture) for a 6-week period during winter. Foraging behaviour was monitored on 95 red deer yearlings by using GPS collars over a 2-week period. Liveweights were recorded at the start and end of the 6-week period. Key results Progeny managed on the kale treatment exhibited an extended activity period during the dawn period and a suppressed activity period during the middle of the day. Progeny managed on the pasture treatment exhibited frequent shorter activity periods from dawn to dusk. Time spent foraging and the number of foraging bouts greater than 5 min in duration were different among progeny of different sires. These differences in behaviour did not affect liveweight gain. Liveweight gain over the 6-week trial period was significantly higher for progeny from one wapiti sire than for all red deer sire progeny while being managed on the kale diet (P < 0.001), but there were no differences among progeny on the pasture diet. Conclusion Foraging behaviour varied considerably between sire lines and appeared to vary between forage type, but there were no correlations between behaviour and liveweight gain in this trial. Implications Forage type offered to young red deer may alter their foraging behaviour. Offering an easier to harvest high digestible forage diet may increase liveweight gain of progeny that have a higher genetic potential to grow during the winter period.
Synthesis of hydrogels incorporating core–shell structured Fe3O4@ZIF-8 as bio-nanocomposite carriers for drug delivery
Authors: Mekrattanachai Pagasukon , Setthaya Naruemon , Chindawong Chakkresit , Yotnoi Bunlawee , Song Wei Guo , Manaspon Chawan
Published: June 2023

Due to its high porosity and excellent pH-sensitive breakdown, the zeolitic imidazolate framework-8 (ZIF-8) has been investigated as a drug delivery vehicle. To increase the magnetic property of ZIF-8 nanoparticles, Fe3O4 nanoparticles (Fe3O4 NPs) were encapsulated to form a core–shell structure (Fe3O4@ZIF-8). The core–shell particles were then incorporated into a hydrogel to increase biocompatibility. The Fe3O4@ZIF-8-incorporated hydrogel nanocomposite (Fe3O4@ZIF-8 hydrogel) was then studied for in vitro cytotoxicity for drug delivery applications. Transmission electron microscopy images confirmed the core–shell structure of the synthesized Fe3O4@ZIF-8 with a central Fe3O4 core and a shell of nano-sized ZIF-8. The specific surface area of the obtained Fe3O4@ZIF-8 was 821 m2 g–1 with a pore volume of 0.36 cm3 g–1. The effect of the prepared Fe3O4@ZIF-8 on cell viability (mouse fibroblast, L929 cell line) was investigated using an MTT (3-(4,5-dimethylthiazolyl-2-yl)-2,5-diphenyltetrazolium bromide) assay. The Fe3O4@ZIF-8 and pure ZIF-8 showed a 50% inhibitory concentration at 28.2 + 1.0 and 11.2 + 6.6 µg mL–1, respectively. A chitosan/pluronic F-127 hydrogel incorporating Fe3O4@ZIF-8 was successfully prepared and showed over 75% cell viability compared to the fresh culture medium. Overall results indicated the safety of using chitosan/pluronic F-127 vehicles containing Fe3O4@ZIF-8 as a carrier for drug delivery systems.
Trachymyrmex septentrionalis
ants promote fungus garden hygiene using
Trichoderma
-derived metabolite cues
Authors: Kyle Kathleen E. , Puckett Sara P. , Caraballo-Rodríguez Andrés Mauricio , Rivera-Chávez José , Samples Robert M. , Earp Cody E. , Raja Huzefa A. , Pearce Cedric J. , Ernst Madeleine , van der Hooft Justin J. J. , Adams Madison E. , Oberlies Nicholas H. , Dorrestein Pieter C. , Klassen Jonathan L. , Balunas Marcy J.
Published: June 2023

Fungus-growing ants depend on a fungal mutualist that can fall prey to fungal pathogens. This mutualist is cultivated by these ants in structures called fungus gardens. Ants exhibit weeding behaviors that keep their fungus gardens healthy by physically removing compromised pieces. However, how ants detect diseases of their fungus gardens is unknown. Here, we applied the logic of Koch’s postulates using environmental fungal community gene sequencing, fungal isolation, and laboratory infection experiments to establish that
Trichoderma
spp. can act as previously unrecognized pathogens of
Trachymyrmex septentrionalis
fungus gardens. Our environmental data showed that
Trichoderma
are the most abundant noncultivar fungi in wild
T. septentrionalis
fungus gardens. We further determined that metabolites produced by
Trichoderma
induce an ant weeding response that mirrors their response to live
Trichoderma
. Combining ant behavioral experiments with bioactivity-guided fractionation and statistical prioritization of metabolites in
Trichoderma
extracts demonstrated that
T. septentrionalis
ants weed in response to peptaibols, a specific class of secondary metabolites known to be produced by
Trichoderma
fungi. Similar assays conducted using purified peptaibols, including the two previously undescribed peptaibols trichokindins VIII and IX, suggested that weeding is likely induced by peptaibols as a class rather than by a single peptaibol metabolite. In addition to their presence in laboratory experiments, we detected peptaibols in wild fungus gardens. Our combination of environmental data and laboratory infection experiments strongly support that peptaibols act as chemical cues of
Trichoderma
pathogenesis in
T. septentrionalis
fungus gardens.
Strategies for new word formation in NGT
Authors: van der Kooij Els , Zwitserlood Inge , Crasborn Onno
Published: June 2023

How do new words arise in a sign language? We present an empirical study of newly formed words in Sign Language of
the Netherlands (NGT). Five signers were asked to create new forms for known concepts for which word forms exist in NGT.
Participants used sequential strategies for word formation, also found in spoken languages. More frequently, however, they used
simultaneous strategies, some of which are unique for the visual-manual modality. We describe and discuss each strategy and focus
on the most prominent of these, namely the simultaneous combination of meaningful form elements (Form-Meaning Units or FMUs). The
abundance of simultaneous combinations of FMUs in our data cannot be explained in terms of concatenative morphology. We propose an
account for word formation phenomena in NGT that uses the phonological segment as the template for simultaneous combinations of
FMUs. This study shows that the FMUs function as basic building blocks for words and accordingly can be considered morphemes.
Given the large set of FMUs in NGT and their frequent occurrence in the newly formed lexical words in our data, we argue for the
acknowledgement of more morphological complexity within the lexicon of sign languages and for a re-evaluation of the relation
between sign language phonology, morphology, and syntax.
Teaching the art of “judicious” translators’ interventions
Authors: Jaccomard Hélène
Published: June 2023

In the capstone unit of a Master of Translation, students were required to write “judicious” interventions (Lefevere 1996) by way of peritextual commentary, be it an introduction, a preface, or a postface. Such interventions are at heart a reaction against the well-documented translators’ invisibility. The hope is that studying patterns of published translators’ interventions of this type and teaching trainee translators to write their own will foster self-reflexivity, confidence and “the virtues of courage and determination” (Chesterman 2001). The article describes how learners were encouraged to meet this outcome, the tasks involved, and how some students in the 2020 cohort fared. It concludes with some suggestions on how to promote best practice in teaching to combat translators’ invisibility.
Analysis of optical channel waveguides composed of bianisotropic materials with a strong magnetoelectric effect using a transmission-line formulation
Authors: Balaei Elham , Shahabadi Mahmoud , Talebi Nahid
Published: June 2023

Optical modes in channel waveguides composed of lossy bianisotropic magnetoelectric (ME) materials have been theoretically investigated here. In this study, a semi-analytical method based on the Fourier expansion technique, a well-known transmission-line formulation, is generalized to ME materials in a general case. Using this method, the dispersion diagram, including both phase and attenuation constants, and the field profile of the guided modes in channel waveguides such as rib waveguides are obtained. The presence of ME materials changes the polarization of guided modes in the structure. In all stages of the analysis, the numerical results are calculated and compared with those generated by commercial electromagnetic solvers to verify the computational efficiency and accuracy of the proposed method.
Electrical and optical properties of C, Ge-doped armchair silicene nanoribbons applied in optoelectronics
Authors: Ngoc Hoang Van , Thuy Huynh Thi Phuong
Published: June 2023

With the continuous development of nanotechnology, the search for new material structures plays a crucial role. Silicene nanoribbons (SiNRs) are one-dimensional materials that hold promise for numerous potential applications in the future. The electric and optical properties of C, Ge-doped armchair SiNRs are investigated in this study using density functional theory. All the doped configurations are stable and maintain the honeycomb hexagonal structure after optimization. Doping with C yields flatter structures, while doping with Ge yields larger buckling heights. The C 1–1 doping configuration is highlighted because its band gap is extended up to 2.35 eV, making it an ideal candidate for potential optoelectronic applications. The charge distribution, charge density difference, and hybridization of multiple orbitals are also systematically studied. The optical properties reveal the differences between C and Ge doping, with a clear anisotropy observed. Strong absorption occurs at high electromagnetic wave energies, while the absorption coefficient rapidly decreases in the long-wavelength range. The study of electron–hole density shows good agreement with the energy band structure, where electron–hole pairs only exist when the excitation energy is greater than the bandgap width, and not all excitation energy values give rise to electron–hole pairs. This study contributes a small part to creating potential applications in nanotechnology.
Study on driving noise of quartz flexible accelerometer torquer
Authors: Zhang Zhigang , Zhao Dongxue , He Huiyong , Tang Lijun , He Qian
Published: June 2023

The distributed capacitance inside the quartz flexible accelerometer (QFA) coupled the high frequency voltage excitation signal in the differential capacitance detection circuit to the torquer coil, and superimposes the torquer driving current to form the driving noise. In this study, the values of the distributed capacitance inside the QFA were simulated. According to the formation mechanism of the QFA driving noise, the equivalent circuit model of the driving noise is established, and the driving noise characteristics of the detection circuit with single excitation and double excitation source are analyzed. The theoretical and experimental results show that the electric field coupled driving noise transmission system is a first-order system with high-pass characteristics. The driving noise of the single excitation detection circuit is larger than that of the dual excitation detection circuit (DEDC), and the DEDC can reduce the driving noise by 39.77% when the QFA shell is grounded. The equivalent acceleration of the electric field coupled driving noise is between tens of μg to hundreds of mg, which is one of the important noise sources that affect the measurement accuracy of the QFA. A measure was proposed to suppress the high-frequency driving noise by adding a low-pass filter after the sampling output of the driving current, which can reduce the driving noise to 1.85 μg and effectively reduce the influence of the driving noise on the measurement accuracy of the QFA.
A high-performance multilayer cylindrical magnetic shielding with a varying layer spacing for NMR sensors
Authors: Jie Shaofeng , Li Jianli , Liu Zhanchao , Mao Yunkai
Published: June 2023

A stable inner working environment is essential for nuclear magnetic resonance sensors, which requires the absence of remnant magnetic fields and fluctuations caused by the surrounding magnetic fields. In this study, we utilized analytical formulations to derive transverse and longitudinal magnetic shielding factors for multilayer cylindrical magnetic shielding. Subsequently, we proposed a novel method for designing and improving the shielding factor by optimizing the spacing of every pair of adjacent layers within a limited volume. The final design result of the multilayer cylindrical magnetic shielding features optimally designed varying layer spacings, which are associated with a specific length and diameter. After optimization, the transverse shielding factor increased by 5.53%, 8.99%, and 13.51% for the three-, four-, and five-layer shields, respectively, compared to traditional magnetic shielding. The opening in the axial center of the magnetic shielding barrel may cause leakage of the magnetic flux and inhomogeneous remnant magnetic induction. We introduced a stovepipe to the end cap of the axial shield based on the finite element method, resulting in an improvement in the homogeneity of remnant magnetic induction. This modification widened the axial uniform region of the innermost shielding layer by approximately 9 cm within 52.5 cm in our simulation. To implement our proposed optimization method, we established and manufactured a four-layer cylindrical magnetic shielding with stovepipes and varying layer spacings. Moreover, the results indicate that this optimal method works for other applications in which multilayer magnetic shielding is required.
Detection of Be dopant pairing in VLS grown GaAs nanowires with twinning superlattices
Authors: Mead Christopher , Huang Chunyi , Isik Goktas Nebile , Fiordaliso Elisabetta Maria , LaPierre Ray R , Lauhon Lincoln J
Published: June 2023

Control over the distribution of dopants in nanowires is essential for regulating their electronic properties, but perturbations in nanowire microstructure may affect doping. Conversely, dopants may be used to control nanowire microstructure including the generation of twinning superlattices (TSLs)—periodic arrays of twin planes. Here the spatial distribution of Be dopants in a GaAs nanowire with a TSL is investigated using atom probe tomography. Homogeneous dopant distributions in both the radial and axial directions are observed, indicating a decoupling of the dopant distribution from the nanowire microstructure. Although the dopant distribution is microscopically homogenous, radial distribution function analysis discovered that 1% of the Be atoms occur in substitutional-interstitial pairs. The pairing confirms theoretical predictions based on the low defect formation energy. These findings indicate that using dopants to engineer microstructure does not necessarily imply that the dopant distribution is non-uniform.
Vortex solutions for pseudo-relativistic Hartree equations
Authors: Yang Jinge , Yang Jianfu
Published: June 2023

In this paper, we study k-vortex solutions of the form

ψ
(
t
,
x
)
=

e

i
(
μ
t
+
k
θ
(

x
1

,

x
2

)
)

u
(
x
)

of the pseudo-relativistic Hartree equation
1

i

ψ
t

(
x
,
t
)
=
(

−
Δ
+

m
2

−
m
)
ψ
(
x
,
t
)
−
(

|

x

|

−
1

∗

|

ψ

|

2

)
ψ
(
x
,
t
)
,
 
 
(
x
,
t
)
∈

R

3

×

R

,

under the constraint

∫

R

3

|

u

|

2

d
x
=
N
.

Such solutions are obtained as minimizers of the problem
2

e
k

(
N
)
=
inf
{

E
k

(
u
)
:
u
∈

H
s

∖
{
0
}
,

∫

ℝ
3

|

u
(
x
,
0
)

|
2

d
x
=
N
>
0
}

with the associated functional

E
k

(
u
)

of (1). We show that there is a threshold value

N
c

(
k
)
>
0

such that problem (2) admits a nonnegative minimizer u

N
if

0
<
N
<

N
c

(
k
)

, and there exists no minimizer for

e
k

(
N
)

if

N
⩾

N
c

(
k
)

. Moreover, the stability of the vortex solution is considered, and the limiting behavior of the minimizer u

N
as

N
→

N
c

(
k

)
−

is described.
Reduced-order particle-in-cell simulations of a high-power magnetically shielded Hall thruster
Authors: Reza M , Faraji F , Knoll A , Piragino A , Andreussi T , Misuri T
Published: June 2023

High-power magnetically shielded Hall thrusters have emerged in recent years to meet the needs of the next-generation on-orbit servicing and exploration missions. Even though a few such thrusters are currently undergoing their late-stage development and qualification campaigns, many unanswered questions yet exist concerning the behavior and evolution of the plasma in these large-size thrusters that feature an unconventional magnetic field topology. Noting the complex, multi-dimensional nature of plasma processes in Hall thrusters, high-fidelity particle-in-cell (PIC) simulations are optimal tools to study the intricate plasma behavior. Nonetheless, the significant computational cost of traditional multi-dimensional PIC schemes renders simulating the high-power thrusters without any physics-altering speed-up factors unfeasible. The novel reduced-order ‘quasi-2D’ PIC scheme enables a significant reduction in the computational cost requirement of the PIC simulations. Thus, in this article, we demonstrate the applicability of the reduced-order PIC for a cost-efficient, self-consistent study of the physics in high-power Hall thrusters by performing simulations of a 20 kW-class magnetically shielded Hall thruster along the axial-azimuthal and radial-azimuthal coordinates. The axial-azimuthal quasi-2D simulations are performed for three operating conditions in a rather simplified representation of the thruster’s inherently 3D configuration. Nevertheless, we have resolved self-consistently an unprecedented 650 µs of the discharge evolution without any ad-hoc electron mobility model, capturing several breathing cycles and approximating the experimental performance parameters with an accuracy of 70%–80% across the operating conditions. The radial-azimuthal simulations, carried out at three cross-sections corresponding to different axial locations within the discharge channel, have casted further light on the evolution of the azimuthal instabilities and the resulting variations in the electrons’ cross-field mobility and the plasma-wall interactions. Particularly, we observed the development of a long-wavelength, relatively low-frequency wave mode near the exit plane of the thruster’s channel that induces a notable electron transport and a significant ion heating.
Degradation mechanism differences between TiN- and TaN-electrode HZO-based FeRAMs analyzed by current mechanism fitting
Authors: Yeh Yu-Hsuan , Chen Wen-Chung , Chang Ting-Chang , Tan Yung-Fang , Wu Chung-Wei , Zhang Yong-Ci , Lee Ya-Huan , Lin Chao Cheng , Huang Hui-Chun , Sze Simon M
Published: June 2023

This paper investigates the difference in electrical performance and reliability arising from using either titanium nitride (TiN) or tantalum nitride (TaN) as the electrode in ferroelectric random access memories. Because the lattice constant of TaN is better matched to HZO, the TaN-electrode device exhibits better characteristic. However, the leakage of TaN-electrode device increases significantly after wake up. To figure out this phenomenon, current fitting is implemented. According to the fitting results of conduction mechanisms, the existence of oxygen vacancies in the TaN-electrode device provides a reliable explanation to propose models to clarify the degradation mechanisms observed from the TiN- and TaN-electode devices.
Study and simulation of the effects of geometry and materials on the detection potential of tapered fiber sensors
Authors: Adouane Azzedine , Ghoumazi Mehdi , Bouchaour Mounir , Guermat Abdelhak
Published: June 2023

In this paper, we have proposed three types of taper structures called L.C.C (L : linear, C : concave and C : convex) that form at the end of the optical fibers in order to use them for detection in order to improve the formation of evanescence waves on the surface of the fiber We studied on these three types of structure four materials such as: silicon (Si), glass (SiO2), sapphire (Al2O3) and zircon (ZrSiO4) with refractive indices 1.45, 1.52, 1.77 and 1.92, respectively. First, three tapered shaped structures were designed with a length ‘L’ set at 50 μm and a diameter ‘D’ equal to 10 μm. Then, they shrink to 1 μm in diameter ‘from the end of their structures. We used an optical DC source with a power amplitude of 1 Vm−1. We also simulated these ‘L.C.C’ structures with the OptiFDTD simulation software, which is based on the finite difference time domain (FDTD) method. The numerical results obtained are: the transverse electric (TE) distribution of the evanescent wave (EW) and the leakage wave (LW) from the left end of the tip for the proposed taper structures. Finally, we presented the transmission. The results obtained showed that the geometric shape (such as the shape of the taper structure) and the type of material (such as the refractive index ‘n’) are very important. These play a crucial role in creating the evanescent waves in the tapered region of the sensor for sensing, which can be used to demonstrate the application of the desired sensor.
Entanglement masquerading in the CMB
Authors: Adil Arsalan , Albrecht Andreas , Baunach Rose , Holman R. , Ribeiro Raquel H. , Richard Benoit J.
Published: June 2023

The simplest single-field inflation models capture all the relevant contributions to the
patterns in the Cosmic Microwave Background (CMB) observed today. A key assumption in these
models is that the quantum inflationary fluctuations that source such patterns are generated by a
particular quantum state — the Bunch-Davies (BD) state. While this is a well-motivated choice
from a theoretical perspective, the question arises of whether current data can rule out other,
also well motivated, choices of states. In particular, as we previously demonstrated
in [1], entanglement is naturally and inevitably dynamically generated
during inflation given the presence of a “rolling” spectator scalar field — and the resulting
entangled state will yield a primordial power spectrum with potentially measurable deviations
compared to the canonical BD result. For this work we developed a perturbative framework to allow
a systematic exploration of constraints on (or detection of) entangled states with Planck CMB data
using Monte Carlo techniques. We have found that most entangled states accessible with our
framework are consistent with the data. One would have to expand the framework to allow a greater
variety of entangled states in order to saturate the Planck constraints and more systematically
explore any preferences the data may have among the different possibilities.
Birth of baby universes from gravitational collapse in a modified-gravity scenario
Authors: Masó-Ferrando Andreu , Sanchis-Gual Nicolas , Font José A. , Olmo Gonzalo J.
Published: June 2023

We consider equilibrium models of spherical boson stars in Palatinif(ℛ) = ℛ +ξℛ2gravity and study their collapse when perturbed. The Einstein-Klein-Gordon system is solved using a recently established correspondence in an Einstein frame representation. We find that, in that frame, the endpoint is a nonrotating black hole surrounded by a quasi-stationary cloud of scalar field. However, the dynamics in thef(ℛ) frame is dramatically different. The innermost region of the collapsing object exhibits the formation of a finite-size, exponentially-expandingbaby universeconnected with the outer (parent) universe via a minimal area surface (a throat or umbilical cord). Our simulations indicate that this surface is at all times hidden inside a horizon, causally disconnecting the baby universe from observers above the horizon. The implications of our findings in other areas of gravitational physics are also discussed.
More on half-wormholes and ensemble averages
Authors: Tian Jia , Yang Yingyu
Published: June 2023

We continue our studyHalf-Wormholes and Ensemble Averagesabout the half-wormhole proposal. By generalizing the original proposal of the half-wormhole, we propose a new way to detect half-wormholes. The crucial idea is to decompose the observables into self-averaged sectors and non-self-averaged sectors. We find the contributions from different sectors have interesting statistics in the semi-classical limit. In particular, dominant sectors tend to condense and the condensation explains the emergence of half-wormholes and we expect that the appearance of condensation is a signal of possible bulk description. We also initiate the study of multi-linked half-wormholes using our approach.
Revisiting p-11B fusion cross section and reactivity, and their analytic approximations
Authors: Tentori Alessandro , Belloni Fabio
Published: June 2023

Proton-boron fusion is experiencing a renewed interest as a possible energy source. The reaction is aneutronic and does not involve radioactive species. It has recently been induced by means of high-power lasers. Ignition of H-11B fuel, however, remains challenging because of the low reactivity and high radiative losses of the plasma at temperatures attainable in present-day fusion devices. Ideal ignition has been demonstrated only lately (and marginally), thanks to revisited cross section data. Reliable, agreed and fit-for-use cross section and reactivity data remain indispensable for further progress in the field. We propose a reference p-11B fusion cross section up to 10 MeV, mostly on the basis of recent measurements. We have developed an analytic approximation for the cross section and, through that, calculated the thermal reactivity. We also provide an analytic approximation for the reactivity, in the temperature range 10–500 keV, which is intended to update that of Nevins and Swain (2000 Nucl. Fusion
40 865), generally taken as a reference. Above 30 keV, our reactivity is substantially higher than that of Nevins and Swain. The gap increases with temperature, reaching e.g. 12% at 100 keV and 50% at 500 keV. Considering also the suprathermal contribution elicited by the fusion-born α’s, we anticipate a potential 50% increase already at 300 keV. Such a higher reactivity is expected to appreciably relax the ideal ignition temperature of H-11B fuel.
Correlation between magnetic and dielectric anomalies arising due to spin-chain arrangements in the paramagnetic phase of 1D Ca3Co1.9Bi0.1O6
Authors: Bisht Gajendra Singh , Pal D.
Published: June 2023

We showed that the ferromagnetic correlation extended far into what was thought to be the paramagnetic phase for pristine Ca3Co2O6 in our Bi-substituted compound and found a correlation between magnetic and dielectric anomaly in this region. We have observed enhancement of dielectric property (dielectric constant 200 with a loss factor 0.01 at 1 MHz), which is attributed to the high ionic polarizability of Bi. The dielectric response curve indicates two stages in the relaxation process, which is confirmed by the two peaks in the loss tangent (tanδ) plot. Higher relaxation time (8.9 × 10−10 s) obtained from analyzing the dielectric response curve using Arrhenius law suggested a collective dielectric relaxation process in this system.
Electrical, Optical and Magnetic Studies of Flower Shaped Fe3O4@Bi2S3 core shell Hierarchical Structure
Authors: khamari S. , Mohapatra N.
Published: June 2023

In this study, we have successfully synthesized the Fe3O4@Bi2S3 core shell hierarchical by a simple and quick sono chemical method. The structural and morphological studies of the prepared core shell structure show presence of single phase with flower shaped like structure. The crystalline grain size of prepared core shell structure is obtained as ∼16 nm from the Scherrer’s equation. The UV-Vis Spectroscopy study and IV characterization of the synthesized core shell material is performed to investigate its optical and electrical behavior. The RAMAN analysis exhibits its crystal orientation, phase and binding energy of these synthesized structure. The magnetic characterization of the core shell nanostructure shows a superparamagnetic behavior with a saturation magnetization of 33.5emu/gm at 5K temperature. These prepared core shell structures may act as promising material for broad spectral photo detection, optoelectronic devices and energy storage application.
Modulating via External Electric Field an Electronic Band Gaps in 2D 1T-PdS2 monolayer
Authors: Raval Dhara , Gupta S. K. , Gajjar P. N.
Published: June 2023

We have examined structural stability and electronics properties of 2D 1T-PdS2 monolayer within the Density Functional Theory (DFT). 1T-PdS2 monolayer has indirect narrow band gap of 1.16 eV along the wave vector path of Γ-M-K-Γ in first Brillouin zone. The positive phonon dispersion curves at gamma point confirmed the dynamic stability of the 1T-PdS2 monolayer. Under the external electric field

E
→

effect, the diverting nature has seen in the electronic band gaps within the intensity span of -5.0 V/Å to +5.0 V/Å along ±Z-direction. Hence, we could modulate the band gaps of semiconductor by applying external electric field, which is helpful for band engineering application. In this way, the semiconductor 2D 1T-PdS2 monolayer is capable candidate for nanoelectronics devices.