bluuebunny/crossref_metadata_2025 huggingface dataset:
Multiscale computational framework to investigate integrin mechanosensing and cell adhesion
Authors: Montes Andre R. , Gutierrez Gabriela , Buganza Tepole Adrian , Mofrad Mohammad R. K.
Published: September 2023

Integrin mechanosensing plays an instrumental role in cell behavior, phenotype, and fate by transmitting mechanical signals that trigger downstream molecular and cellular changes. For instance, force transfer along key amino acid residues can mediate cell adhesion. Disrupting key binding sites within α5β1 integrin’s binding partner, fibronectin (FN) diminishes adhesive strength. While past studies have shown the importance of these residues in cell adhesion, the relationship between the dynamics of these residues and how integrin distributes force across the cell surface remains less explored. Here, we present a multiscale mechanical model to investigate the mechanical coupling between integrin nanoscale dynamics and whole-cell adhesion mechanics. Our framework leverages molecular dynamics simulations to investigate residues within α5β1-FN during stretching and the finite element method to visualize the whole-cell adhesion mechanics. The forces per integrin across the cell surface of the whole-cell model were consistent with past atomic force microscopy and Förster resonance energy transfer measurements from the literature. The molecular dynamics simulations also confirmed past studies that implicate two key sites within FN that maintain cell adhesion: the synergy site and arginine-glycine-aspartic acid (RGD) motif. Our study contributed to our understanding of molecular mechanisms by which these sites collaborate to mediate whole-cell integrin adhesion dynamics. Specifically, we showed how FN unfolding, residue binding/unbinding, and molecular structure contribute to α5β1-FN’s nonlinear force–extension behavior during stretching. Our computational framework could be used to explain how the dynamics of key residues influence cell differentiation or how uniquely designed protein structures could dynamically limit the spread of metastatic cells.
Blockage ratio and Reynolds number effects on flows around a rectangular prism
Authors: Abdul-Salam Fati Bio , Fang Xingjun , Tachie Mark Francis
Published: September 2023

The combined effects of blockage ratio (BR) and Reynolds number (Re) on the spatiotemporal characteristics of turbulent flow separation around a rectangular prism with depth-to-thickness ratio of 3 were investigated using a time-resolved particle image velocimetry. Four different blockage ratios (BR = 2.5%, 5%, 10%, and 15%) were examined at Reynolds numbers of 3000, 7500, and 15000. Two regimes (unattached and reattached) were identified; however, the boundary between these regimes shows a complex dependency on BR and Re. The mean flow does not reattach onto the prism at low BR and Re but tends to reattach when BR and Re increase. The wake vortices are relatively larger for the unattached test cases. The separation bubbles over and in the wake of the prism are dynamically coupled for prisms in the unattached regime but independent of each other in the reattached regime. Spectral analyses of the velocity fluctuations and coefficient of the first proper orthogonal decomposition mode pair reveal a single dominant peak at the same fundamental shedding frequency for the reattached test cases, whereas multiple competing frequencies are observed for test cases in the unattached regime. The Kelvin–Helmholtz frequency increases with an increase in BR and Re. The vortical structures are more organized for prisms in the reattached regime, and their convective velocities in the wake are comparatively higher.
Short range extension delineating the north-eastern limit, and use of atypical habitat by highland Leadbeater’s possum
Authors: Macak Phoebe V. , Nelson Jenny L. , Durkin Louise K. , Cripps Jemma K. , White Matt D. , Emerson Luke D. , Lumsden Lindy F.
Published: September 2023

Within its core highland range, Leadbeater’s possum (Gymnobelideus leadbeateri) occurs predominantly in tall montane ash forest dominated by Eucalyptus regnans, E. delegatensis and E. nitens. To improve predictive modelling of suitable habitat, we surveyed ash/non-ash ecotones and also explored the species’ recently extended eastern distribution. We detected Leadbeater’s possums at 19 sites, including six in non-ash forest dominated by E. dalrympleana, E. viminalis or E. kybeanensis. This extends its known distribution by 5.5 km and appears to delineate the north-eastern limit of its range. Our results add to previous findings indicating Leadbeater’s possums have slightly broader range limits and habitat flexibility than previously thought.
Molecular and cellular programs underlying the development of bovine pre-implantation embryos
Authors: Jiang Zongliang
Published: September 2023

Early embryonic mortality is a major cause of infertility in cattle, yet the underlying molecular causes remain a mystery. Over the past half century, assisted reproductive technologies such as in vitro fertilisation and somatic cell nuclear transfer have been used to improve cattle reproductive efficiency; however, reduced embryo developmental potential is seen compared to their in vivo counterparts. Recent years have seen exciting progress across bovine embryo research, including genomic profiling of embryogenesis, new methods for improving embryo competence, and experimenting on building bovine embryos from stem cell cultures. These advances are beginning to define bovine embryo molecular and cellular programs and could potentially lead to improved embryo health. Here, I highlight the current status of molecular determinants and cellular programs of bovine embryo development and new opportunities to improve the bovine embryo health.
Degradation of conventional, biodegradable and oxo-degradable microplastics in a soil using a δ13C technique
Authors: Huo Yuxin , Dijkstra Feike A. , Possell Malcolm , Dong Andrew Zi , Singh Balwant
Published: September 2023

Context A significant amount of conventional plastics waste, especially in the form of microplastics (MPs), has accumulated in soils due to its limited degradation. Oxo-degradable and biodegradable plastics have also contributed to MP contamination in soils. Aims In this study, we examined the degradation of a conventional plastic [fruit and vegetable (F&V) bag], two biodegradable plastics (bin liner and mulch film) and an oxo-degradable plastic (drinking straw). Methods These plastics (5 mm) were mixed into a soil and incubated in the laboratory at 37 ± 1°C for 185 days. The CO2-carbon (C) mineralisation of the four plastics was determined using a δ13C technique, because the difference in the δ13C values of studied plastics and the experimental soil was ≥10‰. Key results Bin liner showed the greatest C mineralisation (5.7%), followed by mulch film (4.1%), straw (0.4%) and F&V bag (0.3%) at the end of the incubation period. All plastics, except the mulch film for 23–77 days of incubation, caused a positive priming effect on soil organic carbon (SOC). Fourier transform infra-red spectroscopy and scanning electron microscopy analyses were consistent with the C mineralisation data. Conclusions This study determines the degradation of various MPs in soil using a reliable and practical δ13C method, which has been lacking in this field of study. The priming effect of various MPs on SOC is a significant finding. Implications The lack of consideration of priming effect on SOC may overestimate the mineralisation of plastics in soil.
Measuring the long-term costs of uncharacteristic wildfire: a case study of the 2010 Schultz Fire in Northern Arizona
Authors: Hjerpe Evan E. , Colavito Melanie M. , Edgeley Catrin M. , Burnett Jack T. , Combrink Thomas , Vosick Diane , Sánchez Meador Andrew
Published: September 2023

Background Wildfires often have long-lasting costs that are difficult to document and are rarely captured in full. Aims We provide an example for measuring the full costs of a single wildfire over time, using a case study from the 2010 Schultz Fire near Flagstaff, Arizona, to enhance our understanding of the long-term costs of uncharacteristic wildfire. Methods We conducted a partial remeasurement of a 2013 study on the costs of the Schultz Fire by updating government and utility expenditures, conducting a survey of affected homeowners, estimating costs to ecosystem services and updating costs to real 2021 US dollars. Key results Costs associated with the Schultz Fire continued to accrue over 10 years, particularly those associated with post-wildfire flooding, totalling between US$109 and US$114 million. Suppression costs represented only 10% of total costs. Conclusions This study is the first of its kind to include a remeasurement of wildfire costs and to provide a long-term assessment of the same wildfire over a 10-year period. Implications Our results and lessons learned can help standardise approaches for full cost accounting of wildfire and illuminate the breadth of typically latent and indirect economic costs of wildfire such as post-wildfire flooding.
Pathogenic bacteria exploit transferrin receptor transcytosis to penetrate the blood–brain barrier
Authors: Cheng Zhihui , Zheng Yangyang , Yang Wen , Sun Hongmin , Zhou Fangyu , Huang Chuangjie , Zhang Shuwen , Song Yingying , Liang Qi’an , Yang Nan , Li Meifang , Liu Bin , Feng Lu , Wang Lei
Published: September 2023

The human blood–brain barrier (BBB) comprises a single layer of brain microvascular endothelial cells (HBMECs) protecting the brain from bloodborne pathogens. Meningitis is among the most serious diseases, but the mechanisms by which major meningitis-causing bacterial pathogens cross the BBB to reach the brain remain poorly understood. We found that
Streptococcus pneumoniae
, group B
Streptococcus
, and neonatal meningitis
Escherichia coli
commonly exploit a unique vesicle fusion mechanism to hitchhike on transferrin receptor (TfR) transcytosis to cross the BBB and illustrated the details of this process in human BBB model in vitro and mouse model. Toll-like receptor signals emanating from bacteria-containing vesicles (BCVs) trigger K33-linked polyubiquitination at Lys168 and Lys181 of the innate immune regulator TRAF3 and then activate the formation of a protein complex containing the guanine nucleotide exchange factor RCC2, the small GTPase RalA and exocyst subcomplex I (SC I) on BCVs. The distinct function of SEC6 in SC I, interacting directly with RalA on BCVs and the SNARE protein SNAP23 on TfR vesicles, tethers these two vesicles and initiates the fusion. Our results reveal that innate immunity triggers a unique modification of TRAF3 and the formation of the HBMEC-specific protein complex on BCVs to authenticate the precise recognition and selection of TfR vesicles to fuse with and facilitate bacterial penetration of the BBB.
Small molecule activators of TAK1 promotes its activity-dependent ubiquitination and TRAIL-mediated tumor cell death
Authors: Sun Weimin , Wu Guowei , Tian Xinyu , Qi Chunting , Liu Jingli , Tong Yilun , Zhang Mengmeng , Gao Jiayang , Cao Ze , Zhang Yuchao , Liu Zhijun , Tian Xiaoxu , Wu Ping , Peng Chao , Li Jingwen , Tan Li , Shan Bing , Liu Jianping , Li Ying , Yuan Junying
Published: September 2023

TAK1 is a key modulator of both NF-κB signaling and RIPK1. In TNF signaling pathway, activation of TAK1 directly mediates the phosphorylation of IKK complex and RIPK1. In a search for small molecule activators of RIPK1-mediated necroptosis, we found R406/R788, two small molecule analogs that could promote sustained activation of TAK1. Treatment with R406 sensitized cells to TNF-mediated necroptosis and RIPK1-dependent apoptosis by promoting sustained RIPK1 activation. Using click chemistry and multiple biochemical binding assays, we showed that treatment with R406 promotes the activation of TAK1 by directly binding to TAK1, independent of its original target Syk kinase. Treatment with R406 promoted the ubiquitination of TAK1 and the interaction of activated TAK1 with ubiquitinated RIPK1. Finally, we showed that R406/R788 could promote the cancer-killing activities of TRAIL in vitro and in mouse models. Our studies demonstrate the possibility of developing small molecule TAK1 activators to potentiate the effect of TRAIL as anticancer therapies.
The Lasker~Koshland Special Achievement Award in Medical Science awarded to Piet Borst
Authors: Nusse Roel , Shapiro Lucy
Published: September 2023

These are no ordinary times and Piet Borst is no ordinary scientist. In a world challenged by existential threats such as pandemics, climate change and the consequent upsurge in populism, flagrant disinformation, and the global distrust of science and technology, the statesman scientist is a necessary and rare being. Piet Borst has embraced that role for most of his life while remaining a superb biochemist. Borst is this year’s winner of the Lasker~Koshland Special Achievement Award in Medical Science “for research accomplishments and scientific statesmanship that engender the deepest feelings of awe and respect”.
Inducible CRISPR-targeted “knockdown” of human gut
Bacteroides
in gnotobiotic mice discloses glycan utilization strategies
Authors: Beller Zachary W. , Wesener Darryl A. , Seebeck Timothy R. , Guruge Janaki L. , Byrne Alexandra E. , Henrissat Suzanne , Terrapon Nicolas , Henrissat Bernard , Rodionov Dmitry A. , Osterman Andrei L. , Suarez Chris , Bacalzo Nikita P. , Chen Ye , Couture Garret , Lebrilla Carlito B. , Zhang Zhigang , Eastlund Erik R. , McCann Caitlin H. , Davis Gregory D. , Gordon Jeffrey I.
Published: September 2023

Understanding how members of the human gut microbiota prioritize nutrient resources is one component of a larger effort to decipher the mechanisms defining microbial community robustness and resiliency in health and disease. This knowledge is foundational for development of microbiota-directed therapeutics. To model how bacteria prioritize glycans in the gut, germfree mice were colonized with 13 human gut bacterial strains, including seven saccharolytic
Bacteroidaceae
species. Animals were fed a Western diet supplemented with pea fiber. After community assembly, an inducible CRISPR-based system was used to selectively and temporarily reduce the absolute abundance of
Bacteroides thetaiotaomicron
or
B. cellulosilyticus
by 10- to 60-fold. Each knockdown resulted in specific, reproducible increases in the abundances of other
Bacteroidaceae
and dynamic alterations in their expression of genes involved in glycan utilization. Emergence of these “alternate consumers” was associated with preservation of community saccharolytic activity. Using an inducible system for CRISPR base editing in vitro, we disrupted translation of transporters critical for utilizing dietary polysaccharides in
Phocaeicola vulgatus
, a
B. cellulosilyticus
knockdown-responsive taxon. In vitro and in vivo tests of the resulting
P. vulgatus
mutants allowed us to further characterize mechanisms associated with its increased fitness after knockdown. In principle, the approach described can be applied to study utilization of a range of nutrients and to preclinical efforts designed to develop therapeutic strategies for precision manipulation of microbial communities.
Implementation of a two-stage algorithm for NG-GMAW seam tracking and oscillation width adaptation in pipeline welding
Authors: Liu Hongsheng , Xue Ruilei , Zhou Jianping , Bao Yang , Li Xiaojuan
Published: September 2023

Seam tracking and oscillation width adaptation could effectively reduce the sidewall fusion defects in automatic narrow-gap gas metal arc welding (NG-GMAW). This study proposes a two-stage algorithm to realise seam tracking and oscillation width adaptation in NG-GMAW pipeline welding. The first stage involves using the principal component analysis (PCA) eigenvectors to adjust the oscillating centre, enabling seam tracking and oscillation width adaptation for the hot and fill layer. In the second stage, dataset was prepared based on the tracking data from the first stage, which can guide the welding torch trajectory for the cap layer. Experimental results show that the proposed scheme achieves seam tracking and oscillation width adaptation with an accuracy of 0.1 mm.
Nucleolar condensates: A cellular machinery necessary for T cell activation
Authors: Sharma Monica , Shaw Andrey S.
Published: September 2023

Naive T cells must shift from a state of quiescence to an active metabolic state. To do this, T cells must ramp up their production of ribosomes. In this issue, Zhou et al. (2023. J. Cell Biol.https://doi.org/10.1083/jcb.202201096) identify DDB1 and Cul4-associated factor 13 (DCAF13) as a T cell activation–induced nucleolar protein that functions to enhance ribosome biosynthesis. DCAF13 binds to nucleophosmin 1 (NPM1) to form a biomolecular condensate that functions, in part, by recruiting the endonuclease UTP23 into the nucleolus.
Physically viable rotating mass solutions surrounding Kerr black holes
Authors: Viaggiu S
Published: September 2023

There exists in literature an increasing interest in the study of mass distributions surrounding black holes as describing dark matter halo in spiral galaxies. Motivated by this interest, we study a very recent new class of rotating solutions that are suitable to build anisotropic matter sources surrounding rotating black holes. Contrary to the mainstream approach, instead of use the so called regular black holes as central objects, we perform a smooth matching between the aforementioned anisotropic matter and a central vacuum Kerr black hole. In this framework, we study in full generality energy conditions near the matching surface. As a result, we found that, after imposing the vanishing of the energy density E at the matching surface, if weak and dominant energy conditions (WEC,DEC) are satisfied, then unavoidable strong energy conditions is violated, i.e. near the event horizon only matter with dark energy-like features is allowed. As an application, we present two solutions everywhere satisfying DEC. The first one is asymptotically flat and equipped with a non vanishing electric charge, while the second solution presented is equipped with a non-vanishing energy flow around the symmetry axis and it is not asymptotically flat.
Gauge-invariant gravitational waves in matter beyond linearized gravity
Authors: Garg Deepen , Dodin I Y
Published: September 2023

Modeling the propagation of gravitational waves (GWs) in media other than vacuum is complicated by the gauge freedom of linearized gravity in that, once nonlinearities are taken into consideration, gauge artifacts can cause spurious acceleration of the matter. To eliminate these artifacts, we propose how to keep the theory of dispersive GWs gauge-invariant beyond the linear approximation and, in particular, obtain an unambiguous gauge-invariant expression for the energy–momentum of a GW in a dispersive medium. Using analytic tools from plasma physics, we propose an exactly gauge-invariant ‘quasilinear’ theory, in which GWs are governed by linear equations and also affect the background metric on scales large compared to their wavelength. As a corollary, the gauge-invariant geometrical optics of linear dispersive GWs in a general background is formulated. As an example, we show how the well-known properties of vacuum GWs are naturally and concisely yielded by our theory in a manifestly gauge-invariant form. We also show how the gauge invariance can be maintained within a given accuracy to an arbitrary order in the GW amplitude. These results are intended to form a physically meaningful framework for studying dispersive GWs in matter.
An autoencoder compression approach for accelerating large-scale inverse problems
Authors: Wittmer Jonathan , Badger Jacob , Sundar Hari , Bui-Thanh Tan
Published: September 2023

Partial differential equation (PDE)-constrained inverse problems are some of the most challenging and computationally demanding problems in computational science today. Fine meshes required to accurately compute the PDE solution introduce an enormous number of parameters and require large-scale computing resources such as more processors and more memory to solve such systems in a reasonable time. For inverse problems constrained by time-dependent PDEs, the adjoint method often employed to compute gradients and higher order derivatives efficiently requires solving a time-reversed, so-called adjoint PDE that depends on the forward PDE solution at each timestep. This necessitates the storage of a high-dimensional forward solution vector at every timestep. Such a procedure quickly exhausts the available memory resources. Several approaches that trade additional computation for reduced memory footprint have been proposed to mitigate the memory bottleneck, including checkpointing and compression strategies. In this work, we propose a close-to-ideal scalable compression approach using autoencoders to eliminate the need for checkpointing and substantial memory storage, thereby reducing the time-to-solution and memory requirements. We compare our approach with checkpointing and an off-the-shelf compression approach on an earth-scale ill-posed seismic inverse problem. The results verify the expected close-to-ideal speedup for the gradient and Hessian-vector product using the proposed autoencoder compression approach. To highlight the usefulness of the proposed approach, we combine the autoencoder compression with the data-informed active subspace (DIAS) prior showing how the DIAS method can be affordably extended to large-scale problems without the need for checkpointing and large memory.
An ultrasonic in-line inspection data processing method considering invalid data caused by sensor failure
Authors: Wu Zhenning , Huang Hanyang , Zhang Runjiang , Liu Jinhai , Tang Jianhua
Published: September 2023

Ultrasonic in-line inspection is one of the most widely adopted nondestructive testing methods for defect detection in pipelines. In practical industrial scenes, pipeline specification varies, sensor failure occurs frequently, and the number of pipeline defect samples is scarce. How to detect defects without false detection caused by invalid data and with limited labeled samples is a challenging problem in this area. An ultrasonic in-line inspection data processing method considering invalid data caused by sensor failure is proposed in this paper to enhance the accuracy of the defect and its profile detection. Firstly, the multi-channel data is aggregated according to sampling time. The data dimension is reduced, and the accuracy of the invalid waveform detection adopting isolation forest arithmetic is improved. The methods are adopted for the invalid waveforms replacement with two-dimensional cubic spline interpolation using adjacent sensors. Secondly, a natural breakpoint method is adopted to locate the echo peaks. Residual wall thickness is evaluated by calculating the time difference between the echo peaks. A fast pseudo-colorization method based on sliding windows and a morphological image processing method are proposed to detect defects and their profiles efficiently utilizing the residual wall thickness. Finally, practical in-line inspection data is utilized to evaluate the performance. The experiment results illustrate that the detection accuracy is enhanced on different sizes of pipelines without requiring labeled samples.
Reducing the risk of hallucinations with interpretable deep learning models for low-dose CT denoising: comparative performance analysis
Authors: Patwari Mayank , Gutjahr Ralf , Marcus Roy , Thali Yannick , Calvarons Adria F , Raupach Rainer , Maier Andreas
Published: September 2023

Objective. Reducing CT radiation dose is an often proposed measure to enhance patient safety, which, however results in increased image noise, translating into degradation of clinical image quality. Several deep learning methods have been proposed for low-dose CT (LDCT) denoising. The high risks posed by possible hallucinations in clinical images necessitate methods which aid the interpretation of deep learning networks. In this study, we aim to use qualitative reader studies and quantitative radiomics studies to assess the perceived quality, signal preservation and statistical feature preservation of LDCT volumes denoised by deep learning. We aim to compare interpretable deep learning methods with classical deep neural networks in clinical denoising performance. Approach. We conducted an image quality analysis study to assess the image quality of the denoised volumes based on four criteria to assess the perceived image quality. We subsequently conduct a lesion detection/segmentation study to assess the impact of denoising on signal detectability. Finally, a radiomic analysis study was performed to observe the quantitative and statistical similarity of the denoised images to standard dose CT (SDCT) images. Main results. The use of specific deep learning based algorithms generate denoised volumes which are qualitatively inferior to SDCT volumes(p < 0.05). Contrary to previous literature, denoising the volumes did not reduce the accuracy of the segmentation (p > 0.05). The denoised volumes, in most cases, generated radiomics features which were statistically similar to those generated from SDCT volumes (p > 0.05). Significance. Our results show that the denoised volumes have a lower perceived quality than SDCT volumes. Noise and denoising do not significantly affect detectability of the abdominal lesions. Denoised volumes also contain statistically identical features to SDCT volumes.
Evaluation of the transfer matrix of a plasma ramp with squared cosine shape via an approximate solution of Mathieu differential equation
Authors: Romeo S , Biagioni A , Crincoli L , Del Dotto A , Ferrario M , Giribono A , Parise G , Rossi A R , Silvi G J , Vaccarezza C
Published: September 2023

The high longitudinal electric fields generated in plasma wakefields are very attractive for a new generation of high gradient plasma based accelerators. On the other hand, the strong transverse fields increase the demand for a proper matching device in order to avoid the spoiling of beam transverse quality. A solution can be provided by the use of a plasma ramp, a region at the plasma injection/extraction with smoothly increasing/decreasing plasma density. The transport of a beam inside a plasma ramp, beside its parameters, depends on the profile of the ramp itself. Establishing the transfer matrix for a plasma ramp represent a very useful tool in order to evaluate the beam evolution in the plasma. In this paper a study of a cosine squared ramp is presented. An approximate solution of the transverse equation of motion is evaluated and exploited to provide a simple transfer matrix for the plasma ramp. The transfer matrix is then employed to demonstrate that this kind of ramp has the effect to minimize the emittance growth due to betatron dephasing. The behavior of a squared cosine plasma ramp will be compared with an experimentally measured plasma ramp profile in order to validate the applicability of the transfer matrix to real cases.
MOSFET-based HTS flux pump
Authors: Jurčo Róbert , Vaskuri Anna , Curé Benoit , Dudarev Alexey , Mentink Matthias
Published: September 2023

We have developed a high-temperature superconducting (HTS) flux pump using high-power metal-oxide-semiconductor field-effect transistors (MOSFETs) for switching. For its primary coil, two commercial transformers are utilized, each consisting of two copper coils wound on a single iron core, which enables changing the load current over primary current ratio (101 or 194) between the primary and secondary coils. Full-wave rectification is achieved with two half-wave secondary circuits, each of them having six HTS one-turn coils to lower the resistance. Each secondary coil is composed out of nickel-reinforced BSCCO tapes, where 12 MOSFETs have been soldered in parallel straight to the tapes and controlled with analog electronics. Secondary coils are clamped to custom-made copper-stabilized HTS current leads. A support structure for keeping the HTS coils in place was 3D-printed using cryogenic-compatible composite material PETG-CF20. Resistances of the two secondary circuits were measured to be 4

μ
Ω

and 7

μ
Ω

at 77 K with a total critical current of 980 A. We successfully ramped up a 50 µH Conductor on Round Core solenoid at 77 K using our HTS flux pump with 50 Hz AC voltage source. We achieved a maximal load current of 900 A and exceeded the 715 A critical current of the solenoid. During the thermal runaway of the magnet, the increased load voltage limits the maximum load current supplied by the flux pump.
Robust and scalable rf spectroscopy in first-order magnetic sensitive states at second-long coherence time
Authors: Yeh C-H , Grensemann K C , Dreissen L S , Fürst H A , Mehlstäubler T E
Published: September 2023

Trapped-ion quantum sensors have become highly sensitive tools for the search of physics beyond the Standard Model. Recently, stringent tests of local Lorentz-invariance (LLI) have been conducted with precision spectroscopy in trapped ions (Pruttivarasin et al 2015 Nature
517 592–5, Megidish et al 2019 Phys. Rev. Lett.
122 123605, Sanner et al 2019 Nature
567 204–8, Dreissen et al 2022 Nat. Commun.
13 1–6) . We here elaborate on robust radio-frequency composite-pulse spectroscopy at second long coherence times in the magnetic sublevels of the long-lived

2

F

7

/

2

state of a trapped 172Yb+ ion which is scalable to spatially extended multi-ion systems. We compare two Ramsey-type composite rf pulse sequences, a generalized spin-echo (GSE) sequence (Shaniv et al 2018 Phys. Rev. Lett.
120 103202) and a sequence based on universal rotations with 10 rephasing pulses (UR10) (Genov et al 2017 Phys. Rev. Lett.
118 133202) that decouple the energy levels from magnetic field noise, enabling robust and accurate spectroscopy. Both sequences are characterized theoretically and experimentally in the spin-

1

/

2

2

S

1

/

2

electronic ground state of 172Yb+ and results show that the UR10 sequence is 38 (13) times more robust against pulse duration (frequency detuning) errors than the GSE sequence. We extend our simulations to the eight-level manifold of the

2

F

7

/

2

state, which is highly sensitive to a possible violation of LLI, and show that the UR10 sequence can be used for high-fidelity Ramsey spectroscopy in noisy environments. The UR10 sequence is implemented experimentally in the

2

F

7

/

2

manifold and a coherent signal of up to 2.5 s is reached. In (Dreissen et al 2022 Nat. Commun.
13 1–6) we have implemented this sequence and used it to perform the most stringent test of LLI in the electron–photon sector to date with a single Yb+ ion. Due to the high robustness of the UR10 sequence, it can be applied on larger ion crystals to improve tests of Lorentz symmetry further. We demonstrate that the sequence can also be used to extract the quadrupole moment of the meta-stable

2

F

7

/

2

state, obtaining a value of

Θ
=
−
0.0298
(
38
)
e

a

0

2

which is in agreement with the value deduced from clock measurements (Lange et al 2020 Phys. Rev. Lett.
125 143201).
Insight into conduction band density of states at c-Si/TiO2 interface for efficient heterojunction solar cell
Authors: Bagade Sonal Santosh , Patel Piyush K
Published: September 2023

Carrier selective solar cell has become one of the hot spots in the area of Si solar cell. The proposed architecture FTO/TiO2/c-Si/i-a-Si:H/Cu2O/back contact studied through simulation demonstrates a power conversion efficiency of 20.03%. This study is the first to report detailed exploration of effect of the conduction band density of states on the efficiency of Si solar cell. Through optimization, the conduction band density of state (1017 cm-3) drastically increases the power conversion efficiency from 18% (at 1021 cm-3) to 21.25% (at 1017 cm-3) i.e., an improvement of 18% relatively. Along with this, the parameters like absorber layer thickness, absorber’s defect density, thickness of electron transport layer and interface defect density are also optimized. Moreover, the charge transport properties and the impact of the Schottky barrier height at c-Si/TiO2 interface on band alignment is studied. After optimization of various physical parameters such as thickness (100 μm), conduction band density of states (1017 cm-3) and defect concentration (1010 cm−3) of c-Si layer, thickness of TiO2 layer (20 nm) and interface defect density at c-Si/TiO2 junction (1010 cm−2), a short-circuit current of 38.11 mA cm−2, open-circuit voltage of 0.84 V, fill factor of 85.99% is obtained, leading to an enhanced theoretical power conversion efficiency of 27.77%.
Optical soliton solutions of the stochastic perturbed Radhakrishnan-Kundu-Lakshmanan equation via Itô Calculus
Authors: Bayram Mustafa
Published: September 2023

This study presents, for the first time, optical solitons of the stochastic perturbed Radhakrishnan-Kundu-Lakshmanan equation with Kerr law nonlinearity in the presence of chromatic and spatio-temporal dispersions. The stochastic form involves multiplicative white noise in the Ito sense, besides; the Kudryashov and the new Kudryashov methods are picked to analyze. The analysis of the stochastic soliton solutions of the Radhakrishnan-Kundu-Lakshmanan equation and the impact of noise on these solitons are the primary motivations for choosing both of these techniques rather than obtaining many solitons. Therefore, the first goal is to obtain the most basic soliton types, bright and dark solitons, and the second goal is to observe the white noise effect on these solitons. By applying the proposed methods, bright and dark solitons are obtained, and the noise effect on these solitons is illustrated using both 3D and 2D graphic presentations, along with necessary comments. The presentation of the examined model for the first time in this article reflects its originality in terms of contributing both the study and the obtained results to the literature.
Effect of laser-irradiation on some significant physical properties of SeTeIn glass-ceramic
Authors: Chandel N , Elsaeedy H I , Mehta N
Published: September 2023

Laser irradiation on the samples of electronic/optical materials is a versatile tool to modify the structural morphology without changing their composition. We have explored the micro-structural changes (e.g., crystal size, defect state density, etc) induced by the He-Ne laser in Se80Te10In10 alloy. A systematic and detailed investigation of the laser-induced effects in Se80Te10In10 alloy has been undertaken using combinations of microscopic and macroscopic probe techniques like Differential Scanning Calorimeter (DSC), x-ray diffractometer (XRD), Scanning electron microscope (SEM), Transmission electron microscope (TEM). Investigations of the structural, thermal, electrical, and spectroscopic characterization of the Se80Te10In10 alloy have been compared before and after laser exposure. The glass transition/crystallization enthalpies and dielectric constant/loss are significantly increased after laser exposure. The results of structural characterization show that exposure to laser light causes crystal growth which plays a major role in modifying other characteristics of Se80Te10In10 alloy. The comparison of the present results with the literature confirms that laser exposure is a more effective way than the compositional variation approach for tailoring the dielectric properties of the present glass-ceramic sample.
Effect of coating thickness on microstructural and mechanical properties of titanium coated aluminum alloy deposited by vacuum arc melting method
Authors: Suresh Gudala , Zagulyaev Dmitry , Shlyarov Vitaly , Ivanov Yuriy F
Published: September 2023

This study aims to investigate the effects of titanium coatings on aluminum alloy’s tribological and fatigue properties. In this investigation, aluminum alloy samples were coated with 1 μm, 3 μm, and 5 μm using the vacuum arc melting method. The morphological and mechanical features of the samples were characterized with SEM, microhardness, contact nanoprofilometer, and calotest methods. The increase in coating thickness resulted in improved adhesion properties and achieved better surface hardness. Further, hard sub-surface layers on the aluminum alloy substrate increased fatigue resistance. The superior mechanical properties, such as microhardness, lower surface roughness, and good bonding at the interface, are critical factors in increasing the fatigue and wear resistance of the aluminum alloy. No traces of defects, such as microcracks and porosity, were found on the coated samples. The microhardness of the coated sample increased by 3.69 times that of the AK5M2 aluminum alloy. The fatigue lifetime of the 5 μm coated samples was increased by 21%. The wear resistance of titanium-coated samples showed better wear resistance against the steel counter body than other coated and uncoated samples.
A Study of Six Extreme Low Mass Ratio Contact Binary Systems
Authors: Wadhwa Surjit S. , Arbutina Bojan , Petrović Jelena , Filipović Miroslav D. , De Horta Ain Y. , Tothill Nick F. H. , Djurašević Gojko
Published: September 2023

Multi-band (B, V and R) photometric and spectroscopic observations of six poorly studied contact binaries carried out at the Western Sydney University and Las Cumbres Observatory were analyzed using a recent version of the Wilson–Devenney code. All six were found to be of extreme low mass ratio ranging from 0.073 to 0.149. All are of F spectral class with the mass of the primary component ranging from 1.05M
☉ to 1.48M
☉. None show light curve features of enhanced choromospheric activity (O’Connel Effect) however five of the six do have significant ultraviolet excess indicating the presence of increased magnetic and chromospheric activity. Period analysis based on available survey data suggests two systems have a slowly increasing period suggesting mass transfer from the secondary to the primary, two have a slow declining period with likely mass transfer from primary to the secondary, while one shows a steady period, and one undergoing transition from a declining to increasing period suggesting possible mass transfer reversal. We also compare light curve solutions against theoretical markers of orbital stability and show that three of the six systems have mass ratios within the theoretical instability limit and may be regarded as potential merger candidates.
Adsorption Properties of Pb2+ by Ferric Hydroxide Loaded White Rot Fungi
Authors: Li Ningjie , Jiang Hong , Liu Jie , Yang Rui
Published: September 2023

In order to explore the environmental effect of white rot fungi in the formation process of iron hydroxide, white rot fungi loaded with iron hydroxide were used as adsorbent to study the adsorption performance of lead simulated wastewater. The results showed that the iron hydroxide products formed by the mineralization of white rot fungi significantly improved the adsorption effect of heavy metals on the fungus balls. The optimal adsorption conditions were obtained as follows: pH value of 6 at room temperature, initial lead ion concentration of 700 mg/L, adsorbent dosage of 1 g. The adsorption kinetics study shows that when the Pb2+ concentration is less than 1000 mg/L, the quasi-first-order kinetic equation can be used to fit better. When the Pb2+ concentration is 1000 mg/L, the main velocity control process is the quasi-second-order kinetic equation. SEM-EDS was used to characterize the microspheres before and after adsorption. It was found that the surface morphology of white rot fungi loaded with iron oxides changed from uneven to massive mass after adsorption of Pb2+, and the upper layer was covered with a layer of dense spherical lead particles. The different pH conditions also have an effect on the morphology of the microsphere surface, which will make its surface form into clusters of columns.
The Quasi-Phase Matching of Airy Beam
Authors: Zhang Hongwei , Lin Haibo , Wang Jinbao , Yang Jianxi
Published: September 2023

We demonstrate the Airy beam, propagating through a periodically poled nonlinear crystal, could significantly increase the conversion efficiency during the quasi-phase-matched (QPM) process. Meanwhile, the so-called co-Airy beams can be signed as a conjunction of two Airy beams by binding their collinear lateral lobes with appropriate parameters. With the help of the phase-matched modulation, the two Airy beams are united and compressed by the parameters. The set of parameters determines the direction of the “force” that the structure distribution of the co-Airy beams be pressed. We hope that our work will contribute to the generation of multi-Airy beams and further enhancement of research on Airy beam control using quasi-phase-matched crystals.
Research on Source Load Interaction Mode Supporting New Power System
Authors: Xue Yiming , Wang Jie , Sun Beibei , Chen Siqi , Ma Runpeng
Published: September 2023

The construction of a new power system will face challenges such as a high proportion of new energy consumption and a sustainable and reliable power supply. It is urgent to fully tap the potential of demand-side regulation, make up for the shortage of flexible regulation resources of the source side caused by a high proportion of new energy connected to the grid, and promote the transformation of power system operation to the mode of “source load interaction.” One of the effective ways to solve the above problem is to introduce a Hierarchical Load Response Center (HLRC) and establish a load regulation market, effectively promoting user participation in load regulation through market-oriented means. In this paper, the operation framework of “Dispatching Center + Trading Center + Hierarchical Load Response Center” is proposed to support the interaction of source and load under the new power system and the coordination and cooperation relationship of LRC in the operation of the load control market is analyzed. Based on this, the source load interaction mode led by HLRC is analyzed, and the source load interaction modes in the primary and secondary markets are proposed, respectively.
Optimization of thermal link for a conduction-cooled superconducting magnet system
Authors: Liang Qing , Fang Chunliu , Han Xinxin , Zhang Dan , Zhao Weilong , Liu Jing , Liu Jianfei
Published: September 2023

The thermal link between the second stage of cryocooler and
the superconducting magnet has a significant influence on the
initial cooldown time of conduction-cooled superconducting
magnet. In this paper, a numerical investigation is carried out on
the initial cooldown characteristics of a superconducting magnet
system used flexible copper strap as the thermal link. The optimal
shape ratio (cross-sectional area to length) of the copper strap is
obtained to minimize the cooldown time. The results show that
optimal shape ratio decreases with increasing the length. In
addition, the effect of copper purity on the cooldown time is little
at the optimal shape ratio or at RRR (Residual Resistive Ratio) > 
100.
Design of an out-of-tank neutron beam line for prompt gamma neutron activation analysis at low-power Miniature Neutron Source Reactor
Authors: Rahmati E. , Salehi Barough M. , Choopan Dastjerdi M.H. , Mokhtari J.
Published: September 2023

Research reactors are strong and stable neutrons sources,
and various researches and applications were carried out using their
neutron and gamma beamlines. Some research reactors, such as
Miniature Neutron Source (MNSR) Reactors, do not have beam tube in
their original design, which can be considered as a
disadvantage. The design and installation of beamlines can develop
their applications. In this research, the design and optimization of
a suitable neutron beamline for PGNAA is done at Isfahan
MNSR. Designs are done to reach the appropriate neutron beam
parameters and taking into account the geometrical limitations of
the MNSR. Neutron beam parameters including thermal neutron flux,
thermal to total neutron flux, and thermal neutron flux to gamma
dose ratio are considered. For this, vertical beamlines with
different diameters are simulated and the optimal diameter is
determined. Also, for optimization of beam parameters, a thermal
column and gamma filter are considered and optimal conditions are
determined.
A techno-economic assessment on biomass waste-to-energy potential in Cameroon
Authors: Longfor Nkweauseh Reginald , Dong Liang , Wang Jian , Qian Xuepeng
Published: September 2023

Biomass waste-to-energy (WtE) offers a critical solution to carbon neutrality through improving the resource recycling and recovery. This study comprehensively assessed how WtE can be implemented in generating electricity for Cameroon with an estimation to the energy potential of anaerobic digestion of three organic waste streams including municipal solid waste, wastewater sludge, and livestock manure. We assessed the energy potential in terms of the theoretical, technical, and economic potentials. The findings highlighted a theoretical energy potential of 936.37 TWh yr−1 in Cameroon. If only applied to a fraction of organic wastes, the technical potential could reach 48.64 TWh yr−1. Furthermore, considering the economic costs of technology installation, 17.06 TWh yr−1 could be generated, and this economic generation potential could supply to 38.9% of the country’s current electricity demand. This study implies that WtE would significantly reduce fossil fuels consumption and greenhouse gases emissions from poorly disposed wastes, to enable decarbonization transition and improve human health in African countries.
Entanglement capacity of fermionic Gaussian states
Authors: Huang Youyi , Wei Lu
Published: September 2023

We study the capacity of entanglement as an alternative to entanglement entropies in estimating the degree of entanglement of quantum bipartite systems over fermionic Gaussian states. In particular, we derive the exact and asymptotic formulas of average capacity of two different cases—with and without particle number constraints. For the later case, the obtained formulas generalize some partial results of average capacity in the literature. The key ingredient in deriving the results is a set of new tools for simplifying finite summations developed very recently in the study of entanglement entropy of fermionic Gaussian states.
Godbillon-Vey invariants of Non-Lorentzian spacetimes and Aristotelian hydrodynamics
Authors: Marotta Vincenzo Emilio , Szabo Richard J
Published: September 2023

We study the geometry of foliated non-Lorentzian spacetimes in terms of the Godbillon-Vey class of the foliation. We relate the intrinsic torsion of a foliated Aristotelian manifold to its Godbillon-Vey class, and interpret it as a measure of the local spin of the spatial leaves in the time direction. With this characterisation, the Godbillon-Vey class is an obstruction to integrability of the

G

-structure defining the Aristotelian spacetime. We use these notions to formulate a new geometric approach to hydrodynamics of fluid flows by endowing them with Aristotelian structures. We establish conditions under which the Godbillon-Vey class represents an obstruction to steady flow of the fluid and prove new conservation laws.
Entanglement witnessing with untrusted detectors
Authors: Viola Giuseppe , Miklin Nikolai , Gachechiladze Mariami , Pawłowski Marcin
Published: September 2023

We consider the problem of entanglement detection in the presence of faulty, potentially malicious detectors. A common—and, as of yet, the only—approach to this problem is to perform a Bell test in order to identify nonlocality of the measured entangled state. However, there are two significant drawbacks in this approach: the requirement to exceed a critical, and often high, detection efficiency, and much lower noise tolerance. In this paper, we propose an alternative approach to this problem, which is resilient to the detection loophole and is based on the standard tool of entanglement witness. We discuss how the two main techniques to detection losses, namely the discard and assignment strategies, apply to entanglement witnessing. We demonstrate using the example of a two-qubit Bell state that the critical detection efficiency can be significantly reduced compared to the Bell test approach.