bluuebunny/crossref_metadata_2025 huggingface dataset:
Fast, high-quality pseudo random number generators for heterogeneous computing
Authors: Barbone Marco , Gaydadjiev Georgi , Howard Alexander , Luk Wayne , Savvidy George , Savvidy Konstantin , Rose Andrew , Tapper Alexander
Published: May 2024

Random number generation is key to many applications in a wide variety of disciplines. Depending on the application, the quality of the random numbers from a particular generator can directly impact both computational performance and critically the outcome of the calculation. High-energy physics applications use Monte Carlo simulations and machine learning widely, which both require high-quality random numbers. In recent years, to meet increasing performance requirements, many high-energy physics workloads leverage GPU acceleration. While on a CPU, there exist a wide variety of generators with different performance and quality characteristics, the same cannot be stated for GPU and FPGA accelerators. On GPUs, the most common implementation is provided by cuRAND - an NVIDIA library that is not open source or peer reviewed by the scientific community. The highest-quality generator implemented in cuRAND is a version of the Mersenne Twister. Given the availability of better and faster random number generators, high-energy physics moved away from Mersenne Twister several years ago and nowadays MIXMAX is the standard generator in Geant4 via CLHEP. The MIXMAX original design supports parallel streams with a seeding algorithm that makes it especially suited for GPU and FPGA where extreme parallelism is a key factor. In this study we implement the MIXMAX generator on both architectures and analyze its suitability and applicability for accelerator implementations. We evaluated the results against “Mersenne Twister for a Graphic Processor” (MTGP32) on GPUs which resulted in 5, 13 and 14 times higher throughput when a 240, 17 and 8 sized vector space was used respectively. The MIXMAX generator coded in VHDL and implemented on Xilinx Ultrascale+ FPGAs, requires 50% fewer total Look Up Tables (LUTs) compared to a 32-bit Mersenne Twister (MT-19337), or 75% fewer LUTs per output bit. In summary, the state-of-the art MIXMAX pseudo random number generator has been implemented on GPU and FPGA platforms and the performance benchmarked.
Opticks: GPU Optical Photon Simulation via NVIDIA OptiX
Authors: Blyth Simon C.
Published: May 2024

Opticks is an open source project that accelerates optical photon simulation by integrating GPU ray tracing, accessed via the NVIDIA OptiX 7+ API, with Geant4 based simulations. A single NVIDIA Turing GPU from the first RTX generation has been measured to provide optical photon simulation speedup factors exceeding 1500 times single threaded Geant4 with a full JUNO analytic GPU geometry automatically translated from the Geant4 geometry. Optical physics processes of scattering, absorption, scintillator reemission and boundary processes are implemented in CUDA programs based on Geant4. Wavelength-dependent material and surface properties as well as inverse cumulative distribution functions for reemission are interleaved into GPU textures providing fast interpolated property lookup or wavelength generation.

In this work we describe the near complete re-implementation required to adopt the entirely new NVIDIA OptiX 7+ API, with the implementation now directly CUDA based with OptiX usage restricted to providing intersects. The re-implementation features a modular many small header design that enables fine grained testing both on GPU and CPU together with large code reductions from CPU/GPU sharing. Enhanced modularity has enabled CSG tree generalization to support "list-nodes", similar to G4MultiUnion, that improve performance for complex CSG solids. In addition support for interference effects on boundaries with multiple thin layers, such as anti-reflection coatings and photocathodes, using CUDA compatible transfer matrix method (TMM) calculations of reflectance, transmittance and absorptance are reported.
Optimising the Configuration of the CMS GPU Reconstruction
Authors: Ebrahim Abdulla , Bocci Andrea , Elmedany Wael , Al-Ammal Hesham
Published: May 2024

Particle track reconstruction for high energy physics experiments like CMS is computationally demanding but can benefit from GPU acceleration if properly tuned. This work develops an autotuning framework to automatically optimise the throughput of GPU-accelerated CUDA kernels in CMSSW. The proposed system navigates the complex parameter space by generating configurations, benchmarking performance, and leveraging multi-fidelity optimisation from simplified applications. The autotuned launch parameters improved CMSSW tracking throughput over the default settings by finding optimised, GPU-specific configurations. The successful application of autotuning to CMSSW demonstrates both performance portability across diverse accelerators and the potential of the methodology to optimise other HEP codebases.
Performance of Heterogeneous Algorithm Scheduling in CMSSW
Authors: Bocci Andrea , Jones Christopher , Kortelainen Matti J.
Published: May 2024

The CMS experiment started to utilize Graphics Processing Units (GPU) to accelerate the online reconstruction and event selection running on its High Level Trigger (HLT) farm in the 2022 data taking period. The projections of the HLT farm to the High-Luminosity LHC foresee a significant use of compute accelerators in the LHC Run 4 and onwards in order to keep the cost, size, and power budget of the farm under control. This direction of leveraging compute accelerators has synergies with the increasing use of HPC resources in HEP computing, as HPC machines are employing more and more compute accelerators that are predominantly GPUs today. In this work we review the features developed for the CMS data processing framework, CMSSW, to support the effective utilization of both compute accelerators and many-core CPUs within a highly concurrent task-based framework. We measure the impact of various design choices for the scheduling of heterogeneous algorithms on the event processing throughput, using the Run-3 HLT application as a realistic use case.
XkitS：A computational storage framework for high energy physics based on EOS storage system
Authors: Cheng Yaosong , Bi Yujiang , Cheng Yaodong , Li Haibo , Gao Yu , Zhang Minxing
Published: May 2024

Large-scale high-energy physics experiments generate scientific data at the scale of petabytes or even exabytes, requiring high-performance data IO for processing. However, in large computing centers, computing and storage devices are typically separated. Large-scale data transfer has become a bottleneck for some data-intensive computing tasks, such as data encoding and decoding, compression, sorting, etc. The time spent on data transfer can account for 50% of the entire computing task. The larger the amount of data accessed, the more significant this cost becomes. One attractive solution to address this problem is to offload a portion of data processing to the storage layer. However, modifying traditional storage systems to support computation offloading is often cumbersome and requires a broad understanding of their internal principles. Therefore, we have designed a flexible software framework called XkitS, which builds a computable storage system by extending the existing storage system EOS. This framework is deployed on the EOS FTS storage server and offloads computational tasks by invoking the computing capabilities (CPU, FPGA, etc.) on FTS. Currently, it has been tested and applied in the data processing of the Large High Altitude Air Shower Observatory (LHAASO), and the results show that the time spent on data decoding using the computable storage technology is half of that using the original method.
Improving Noisy Hybrid Quantum Graph Neural Networks for Particle Decay Tree Reconstruction
Authors: Strobl Melvin , Kuehn Eileen , Fischer Max , Streit Achim
Published: May 2024

With the emergence of the research field of Quantum Machine Learning, interest in finding advantageous real-world applications is growing as well. However, challenges concerning the number of available qubits on Noisy Intermediate Scale Quantum (NISQ) devices and accuracy losses due to hardware imperfections still remain and limit the applicability of such approaches in real-world scenarios. Therefore, for simplification, most studies assume nearly noise-free conditions as they are expected with logical, i.e. error-corrected, qubits instead of real qubits provided by hardware. However, the number of logical qubits is expected to scale slowly as they require a high number of real qubits for error correction. This is our motivation to deal with noise as an unavoidable, non-negligible problem on NISQ devices. As an application, we use the example of particle decay tree reconstruction as a highly complex combinatoric problem in High Energy Physics. We investigate methods to reduce the noise impact of such devices and propose a hybrid architecture that extends a classical graph neural network by a parameterized quantum circuit. While we have shown that such a hybrid architecture enables a reduction of the amount of trainable parameters compared to the fully classical case, we are now specifically interested in the actual performance in more realistic, i.e. noise prone scenarios. Using simple synthetic Decay Trees, we train the network in classical simulations to allow for efficient optimization of the parameters. The trained parameters are validated in noisy simulations based on devices by "IBM Quantum" and are used in interpretability and significance studies, enabling improvements in the accuracy on real devices.
Umbilical Catheter Extravasation Mimicking Necrotizing Enterocolitis
in a Preterm Neonate: A Diagnostic Challenge
Authors: Armağan Coşkun , Çapıtlı Tevfik , Dilmen Gülsüm , Kefeli Saadet Çağla , Ulusoy Oktay , Erdoğan Funda , Duman Nuray , Özkan Hasan
Published: May 2024

Managing acute abdomen in very low birth weight (VLBW) and premature infants
presents a diagnostic challenge, often necessitating a thorough assessment to
discern underlying causes. Umbilical venous catheters (UVCs), commonly used in
neonatal intensive care, are essential but not without risks. A 29-week
premature male infant, born to a 23-year-old mother, was referred to our clinic
on the 16th day of life with a suspected diagnosis of necrotizing
enterocolitis (NEC). The infant had spent the first day intubated and received
non-invasive respiratory support for 15 days. A 5 French UVC was inserted at the
2nd hour of life, and by the 3rd day of life, the
infant transitioned to minimal enteral feeding. Between the 12th and
16th days of life, the infant initially diagnosed with NEC due to
symptoms such as decreased stool passage and abdominal distension. The patient
had been on a continuous course of antibiotic treatment throughout the entirety
of his life, commencing on the very first day due to suspected early neonatal
sepsis, followed by nosocomial sepsis during the hospitalization, and persisting
with antibiotic therapy for suspected NEC. The case took a unique turn upon
further evaluation after being referred to our unit. Despite a preliminary NEC
diagnosis, further evaluation revealed umbilical catheter complications, leading
to total parenteral nutrition extravasation. Removal of the catheter, drainage,
and antibiotic adjustment resulted in improved clinical outcomes. In neonatal
care, cautious management is vital when dealing with infants exhibiting
abdominal symptoms. A nuanced approach, including differential diagnosis and
careful antibiotic use, is essential.
Effekte einer motivationalen Intervention auf die Wirksamkeit und
Nachhaltigkeit der Sport- und Bewegungstherapie in der stationären
psychiatrischen Versorgung
Authors: Sauer Frank , Schmitz-Buhl Mario , Gouzoulis-Mayfrank Euphrosyne
Published: May 2024

Ziel Verstärkung und Nachhaltigkeit der Sport- und Bewegungstherapie in
der stationären Depressionsbehandlung.

Methodik Randomisierte kontrollierte Studie mit 3 Messzeitpunkten:
t0 Aufnahme in die Studie, t1 nach vier Wochen,
t2 zwei Monate nach Entlassung. Es wurden 96 stationäre Patienten
mit depressiver Störung (ICD-10 F32, F33) randomisiert einer Interventionsgruppe
(IG) oder einer Kontrollgruppe (KG) zugeteilt. Zusätzlich zur Sport- und
Bewegungstherapie (KG) erhielt die IG eine edukative und motivationsfördernde
Sitzung zur Bedeutung von Sport und Bewegung sowie ein motivationsförderndes
Abschlussgespräch.

Ergebnisse Die Ausdauerleistungsfähigkeit und die körperliche Fitness
verbesserten sich über die 3 Messzeitpunkte in der IG deutlicher als in der KG.
Das motivationale Abschlussgespräch wurde als hilfreicher bewertet.

Diskussion Die Intervention wurde von den Patienten gut angenommen und
konnte die Wirkungen der Sport- und Bewegungstherapie teilweise verstärken. Es
wurden nicht nur psychische Aspekte der Depressionsbehandlung beeinflusst,
sondern auch messbare physische Effekte.

Schlussfolgerung Die praxistaugliche und zeiteffiziente motivationale
Intervention kann in der stationären psychiatrischen Versorgung die Sport- und
Bewegungstherapie für depressive Patienten sinnvoll ergänzen.
N-Alkyl-1,2,4-triazole–Borane Complexes as High-Density Hypergolic Materials
Authors: He Chunlin , Jia Hongfu , Ma Wenqi , Chang Jinjie
Published: May 2024

Hydrazine and its derivatives have served as a conventional bipropellant fuel for several decades. However, their extremely acute toxicity and carcinogenicity, high volatility, and environmental impact have attracted significant attention. In order to synthesize green bipropellant fuels with high density, high specific impulse, and good thermal stability, three novel N-alkyl-1,2,4-triazole–borane complexes were successfully synthesized by reacting alkylated 1,2,4-triazole coordinated with sodium borohydride in the presence of ammonium sulfate. During the droplet test with white fuming nitric acid, there was a relatively short ignition delay time of 98 ms. Additionally, these hypergolic fuels possessed a high density exceeding 1.10 g cm–3, and the specific impulse is ranging from 187 to 199 s, and the highest decomposition temperature reaches 153.4 °C. These results demonstrate their great potential as hypergolic fuels or hypergolic ionic liquid additives in the field of hypergolic materials.
Rehabilitation Program for Postlaryngectomy Patients Following Ileocolon Flap Transfer for Voice Reconstruction: An Essential Part of Success
Authors: Lin Kai-Yuan Katie , Huang Chi-wen , Chen Shih-Heng , Lee Jian-Jr , Chen Hung-chi
Published: May 2024

Background Speech restoration is important for communication and social activities after pharyngolaryngectomy in head and neck cancer or corrosive injury. Several techniques of voice restoration have been developed to improve life quality. The aim of this paper was to focus on the microsurgical transfer of ileocolon flap and outcome of further voice rehabilitation.

Patients and Methods From 2010 to 2022, 69 patients had ileocolon flap at our hospital with postoperative speech training and regular follow-up for over 1 year. The patients received deglutition training first, followed by voice rehabilitation. Voice outcomes were evaluated at an interval of 3 months and finally at 12 months of voice training rehabilitation. Among other examinations, the speech function was evaluated using a 4-point Likert scale and senior surgeon (H-c.C.) scoring system.

Results The results showed that speech function reached 13.1% of excellent voice, 65.1% of good voice, 13.1% of fair result, and 8.7% of poor result by Likert scales. Meanwhile, the senior surgeon (H-c.C.) score showed 17.4% of excellent, 63.8% of moderate, and 18.8% of poor results. About voice laboratory results, maximal phonation time was 11.0 seconds, and the average number counted in one breath was 15. Loudness and frequency showed 56.0 dB and 105.0 Hz, respectively.

Conclusion The study showed that after voice reconstruction with ileocolon flap followed by the voice rehabilitation program, the patients would have a better understanding of the altered anatomical structures and practice in a more efficient way. Adequate recommendation by the therapists to plastic surgeons for revision surgeries optimized voice function of the patients.
One-Pot Synthesis of Diverse Anion-Binding Macrocycles
Authors: Madhavan Nandita , Baliarsingh Biswaranjan
Published: May 2024

A one-pot synthetic protocol to access a diverse library of diamide–diester macrocycles from the same starting materials is reported. The molecular symmetry can be readily tuned based on the reaction sequence, while the core structure can be varied using amino acids and aromatic building blocks. The first class of macrocycles with C2 axes in their molecular plane were obtained in 24 h with 40–70% yield, while another class with C2 axes perpendicular to the plane were synthesized in 18 h in 10–30% yield. The phenyl- and serine-derived macrocycles of the first class could bind acetate, chloride, and phosphate ions. These macrocycles can be functionalized with hydrophobic groups and potentially be used as ion transporters.
A Convergent Approach to the Forskolin Skeleton
Authors: Ononiwu Fortune O. , Wang Bo , Totah Nancy I.
Published: May 2024

A convergent approach to the forskolin skeleton is described. Assembly of a simplified tricyclic framework is achieved in a single step via the dihydropyrone Diels–Alder reaction. Selective manipulation of the resulting cycloadduct, in conjunction with an unusual equilibration of the C8 stereocenter, provides access to scaffolds that differ in relative stereochemistry at both the A/B and B/C ring junctions.
Environmental Homeopathy: Homeopathic Potencies Regulate the Toxicity and Growth of Raphidiopsis raciborskii (Cyanobacteria) and can be Tracked Physico-Chemically. Part 1: Biological Results
Authors: Mohammad Suham Nowrooz , Pinto Andreia Adelaide G. , Silva Rodrigo Augusto da , Suffredini Ivana Barbosa , Tournier Alexander L. , Cartwright Steven J. , Yunes João Sarkis , Bonamin Leoni V.
Published: May 2024

Introduction Cyanobacteria are microorganisms found in many parts of the world and several genera, such as Raphidiopsis raciborskii, are producers of cyanotoxins. Homeopathic potencies have been found to modulate toxicity in different biological models, and the present study endeavors to discover whether this might also be the case with cyanobacteria.

Objectives Our objective was to investigate the possible effects of homeopathic potencies on the resilience of Artemia franciscana (brine shrimp) embryos to saxitoxin (STX; cyanotoxin) and on controlling the growth of R. raciborskii in vitro.

Method A. franciscana cysts were cultivated in seawater in 96-well plates to evaluate the hatching rate and vitality, plus the gene expression of heat shock proteins (HSPs), after being challenged with R. raciborskii extract containing 2.5 µg/L of STX and treated with different homeopathic potencies. Untreated wells were used as controls (“base-line”). Potencies were chosen from a screening process based on seven selected homeopathic preparations according to the similitude of STX symptoms (Sulphur, Zincum metallicum, Nitric acidum, Plumbum metallicum, Mercurius solubilis, Phosphoric acidum, Isotherapic from R. raciborskii extract; all at 6cH, 30cH and 200cH). Cultures of R. raciborskii maintained in an artificial seawater medium were equally treated with screened homeopathic potencies selected from the same list but specifically for their growth control as a function of time.

Results A 15% lower rate of hatching of A. franciscana cysts was observed after treatment with Nitric acidum 6cH in comparison with baseline (p = 0.05). A complete toxicity reversal was seen after treatment with Isotherapic 200cH, with a 23-fold increase of Hsp 26 gene expression (p = 0.023) and a 24-fold increase of p26 gene expression (p ≤ 0.001) in relation to baseline. Nitric acidum 200cH and Mercurius solubilis 30cH limited the exponential growth of cyanobacteria up to 95% and 85% respectively (p ≤ 0.003) in relation to baseline. Succussed water presented only a transitory 50% inhibition effect.

Conclusion Isotherapic 200cH improved A. franciscana bioresilience to STX; Nitric acidum 200cH and Mercurius solubilis 30cH showed the optimal performance on limiting R. raciborskii growth. The results point to the potential of homeopathic potencies to mitigate environmental problems related to water quality.
An in-depth exploration of recent advances and promising outlooks in biogas production
Authors: Rodrigues Antonio Felipe da Silva , Sales Misael B. , Braz Ana K. de S. , Bizerra Viviane de C. , Sousa Patrick da S. , Lima Rita K. C. de , Guimarães Artemis P. , Souza Maria C. M. de , Lopes Ada A. S. , Junior Paulo G. de S. , Neto Francisco S. , Melo Rafael L. F. , Valério Roberta B. R. , Cavalcante Antônio L. G. , Lima Ana M. da S. , Serpa Juliana de França , Rios Maria A. de S. , Vale Maria do Socorro , Santos José C. S. dos
Published: May 2024

Biogas is a product composed of a mixture of gases resulting from the biological decomposition of organic material, consisting primarily of methane gas and carbon dioxide, besides smaller amounts of other gases. The current study aims to comprehensively analyze waste-based biogas production to ensure sustainability in the biofuel production process. An advanced systematic bibliometric analysis using keywords, co-citations, and bibliographic coupling analysis was performed on 641 peer-reviewed articles from Web of Science to conclude this goal further. This analysis covers the period from 2000 to 2022, a little more than 20 years. The methodology used reveals several themes that have been identified and addressed in the articles: (1) the importance of the topic in academia by country in which they were analyzed; (2) sectors contributing to biofuel production; (3) equipment used in biofuel production; (4) the most cited waste sources in the database; (5) application purpose of biogas; (6) relevance of other energy sources; (7) areas of interest where biofuels are used; and (8) a comparison between the energy production capacity and the number of publications on the topic by country. Furthermore, the potentials, limitations, perspectives, and future trends highlighted to improve the production process are also considered. Therefore, the conclusion is that organic waste can be used in the sustainable production of goods with added value for society.
h-B12: A cluster-based two-dimensional honeycomb semiconductor
Authors: Li Ni , Qiu Jing-Yi , Liu Zhao , Wang Jing , Liu Ying
Published: May 2024

Icosahedral B12 serves as a fundamental building block for a variety of boron allotropes and plays a crucial role in enhancing the stability of fullerene-like boron nanoclusters. However, progress in the development of two-dimensional (2D) functional assemblies made from icosahedral B12 has been limited. In this context, we propose a 2D semiconducting boron allotrope (h-B12) using icosahedral B12 as a building block. This structure features a stable honeycomb lattice, with its unit cell comprising two mirror-symmetric icosahedral B12 clusters. The results of first-principles calculations indicate that the band structure exhibits Dirac cones and a relatively high group velocity, similar to graphene. Additionally, it is found to be a material with a negative Poisson's ratio and a relatively low Young's modulus. Finally, our calculations reveal that the zigzag nanoribbon constructed from h-B12 displays prominent edge states at both edges, indicating that this structure represents a potential topological electronic material. Our findings shed light on the design and construction of nano-electronic materials via cluster assembly.
4H–SiC vertical magnetotransistor with microtesla detectivity up to 500 °C
Authors: Okeil Hesham , Wachutka Gerhard
Published: May 2024

In this Letter, we demonstrate the operation of an in-plane magnetic field sensitive 4H–SiC vertical magnetotransistor over a wide range of temperatures, ranging from room temperature up to 500 °C. The sensor is realized using the ion-implanted wells of a wafer-scale 4H–SiC Bipolar-CMOS-DMOS technology. We measure and analyze the sensor's DC characteristics, magnetic sensitivity, linearity, and noise performance and determine the achievable magnetic detectivity, which lies in the low μT/Hz regime up to 500 °C. Furthermore, we elaborate on the origin of the observed magnetic sensitivity using TCAD simulations.
Spatially averaged global model of HBr/Cl2 inductively coupled plasma discharges
Authors: Chung Sang-Young , Yook Yeong Geun , Chang Won-Seok , Choi Heechol , Im Yeon Ho , Kwon Deuk-Chul
Published: May 2024

The utilization of HBr/Cl2 mixed gas discharge in semiconductor etching processes has been a subject of analysis both experimentally and through simulations to understand its discharge characteristics. In this study, we have developed a model that extends the previous global model of the HBr/Cl2 plasma. The electron temperature and densities are solved in a self-consistent manner, while previous global model uses the measured electron temperature and electron density. Additionally, we have included further data on electron collision reactions to enhance accuracy. This model was then compared with experimental results obtained from pure HBr, pure Cl2, and HBr/Cl2 plasmas. The calculated results align well with the experimental findings within the margin of error. One notable observation from our study is the occurrence of an unusual phenomenon: as the HBr partial concentration increased, the Br+ ion flux initially increased until the ratio reached 0.5, after which it decreased. This behavior can be attributed to Br+ ions being predominantly produced through collisions between Br atoms and electrons. The dominant mechanisms for Br atom generation involve dissociations by Cl radicals, such as Br2 + Cl → Br + BrCl. Consequently, there exists an optimal flow rate at which the Br+ ion flux is maximized.
Phase transition and polar cluster behavior above Curie temperature in ferroelectric BaTi0.8Zr0.2O3
Authors: Aktas Oktay , Romero Francisco Javier , He Zhengwang , Linyu Gan , Ding Xiangdong , Martín-Olalla José-María , Gallardo María-Carmen , Lookman Turab
Published: May 2024

We study the phase transition behavior of the ferroelectric BaTi0.8Zr0.2O3 in the paraelectric region. The temperature dependencies of thermal, polar, elastic, and dielectric properties indicate the presence of local structures above the paraelectric–ferroelectric transition temperature Tc = 292 K. The non-zero remnant polarization is measured up to a characteristic temperature T* ∼ 350 K, which coincides with the temperature where the dielectric constant deviates from the Curie–Weiss law. Resonant piezoelectric spectroscopy shows that DC field cooling above Tc using fields smaller than the coercive field leads to an elastic response and remnant piezoelectricity below T*, which likely corresponds to the coherence temperature associated with polar nanostructures in ferroelectrics. The observed remnant effect is attributed to the reorientation of polar nanostructures above Tc.
Giant persistent photoconductivity of VO2 device by single-pulse femtosecond laser
Authors: Lee Gi Yong , Lee Hyojeong , Mun Bongjin Simon , Suk Hyyong , Ju Honglyoul
Published: May 2024

The manifestation of giant persistent photoconductivity (GPPC) is demonstrated with a fs (femtosecond) Ti:sapphire laser pulse that has a duration of 40 fs and a central wavelength of 400 nm. The femtosecond laser pulse was irradiated on a two-terminal VO2 device fabricated on a corning glass substrate. Under the applied voltages of 9–12 V, the GPPC takes place within 8.6–15 μs after the laser irradiation. The photocurrent from the GPPC in the VO2 device remains stable with the current decreasing slope of ∼0.003%/minute. With one-dimensional thermal model, the temperature (TIR) of the irradiated area is estimated as a function of time, indicating that TIR is above the insulation-to-metal transition temperature of VO2 thin film prior to the onset of GPPC. The ultrafast onset of GPPC of VO2 device can be utilized for ultrafast optoelectronic switch and memory device.
Polymer optical fiber amplifier based on all-inorganic perovskite quantum dots
Authors: Wang Yue , Kang Chun Hong , Alkhazragi Omar , Guitiérrez-Arzaluz Luis , Li Kuang-Hui , Ng Tien Khee , Mohammed Omar F. , Ooi Boon S.
Published: May 2024

The proliferation of polymer optical fibers (POFs) has opened multiple avenues of optical-based networks and sensing applications in the visible spectral range. However, the lack of efficient amplifiers significantly hinders their utilization in practical scenarios. As emerging gain media, halide perovskites have attracted considerable attention in exploring their practical applications. In this Letter, we investigated the optical gain properties of cesium lead bromide quantum dots (CsPbBr3 QDs), and by facet dip-coating, we realized a polymer optical fiber amplifier. Under a 400-nm, 163-fs Ti:Sapphire laser pumping, the amplified spontaneous emission (ASE) thresholds of 1.6 and 20.1 μJ/cm2 were achieved through stripe pumping of a QDs-thin-film and end-pumping of a polymer-fiber facet dip-coated with the QDs, respectively. A gain coefficient of 232.2 ± 22.8 cm−1 was obtained using the variable stripe length method. By coupling a broadband continuous-wave light source into the POF as the signal, the optical gain behavior was studied with varying pump fluence and signal power density. More than 20 dB optical gain was achieved within the ASE wavelength region of 530–540 nm with a predicted theoretical maximum gain of 33.6 dB. The research verifies the feasibility of amplifying continuous-wave signals in the visible spectrum and potentially closing the research gap in visible-light optical-to-optical amplifiers. This opens the avenue for further research and innovations in practical polymer-based optical amplification for a plethora of applications, including all optical processing chips and short-range interconnects, as well as visible-light and underwater communications.
A numerical modeling study on the impact of particle concentration on the particle sorting in spiral channels
Authors: Van Anh-Duc , Pham Van-Sang
Published: May 2024

This work investigates the influence of concentration on the separation of microparticles in spiral microchannels. Using numerical modeling, we study the impact of the particle concentration on fluid flow pattern, particle trajectory, focusing resolution, and focusing time. Immersed boundary method and a numerical solver are developed in the OpenFOAM framework for modeling of particle motion. Modeling for different particle concentration in both rectangular and trapezoidal spiral channels is conducted to elucidate the particle focusing and separation efficiency in the spiral channels with a large number of particles. The detailed numerical modeling results clarify the configuration of Dean flow with multiple particles, the interaction within the particle cloud, and the impact of particle concentration on the focusing time and sorting process.
Tidal turbine blade design optimization based on coupled deep learning and blade element momentum theory
Authors: Li Changming , Liang Bingchen , Yuan Peng , Liu Bin , Zhao Ming , Zhang Qin , Tan Junzhe , Liu Jiahua
Published: May 2024

The practical design optimization of blade structures is crucial for enhancing the power capture capability of tidal turbines. However, the significant computational costs required for directly optimizing turbine blades through numerical simulations limit the practical application of blade structure optimization. This paper proposes a framework for tidal turbine blade design optimization based on deep learning (DL) and blade element momentum (BEM). This framework employs control points to parameterize the three-dimensional geometric shape of the blades, uses convolutional neural networks to predict the hydrodynamic performance of each hydrofoil section, and couples BEM to forecast the performance of tidal turbine blades. The multi-objective non-dominated sorting genetic algorithm II is employed to optimize the geometric parameters of turbine blades to maximize the power coefficient and minimize the thrust coefficient, aiming to obtain the optimal trade-off solution. The results indicate that the prediction of the DL-BEM model agrees well with experimental data, significantly improving optimization efficiency. The optimized tidal turbine blades exhibit excellent power coefficients and reduced thrust coefficients, achieving a more balanced structural solution. The proposed optimization framework based on DL accurately and rapidly predicts the performance of tidal turbines, facilitating the design optimization of high-performance tidal turbine blades.
Viscous flow and collapse of macroscopic cavities in a granular material
Authors: Sano Osamu
Published: May 2024

The viscous flow in a granular material containing macroscopic cavities (or clear fluid regions) is determined on the basis of the generalized Darcy equation (outside the cavity region) and the Stokes equation (inside the cavity region). A three-dimensional singularity termed a “Darcylet”, which is a fundamental solution in the granular material, is distributed over the surface of a spherical cavity of unit size that surrounds the isolated singularity. The latter is calibrated with the exact solution and applied to describe the interaction between two cavities, which successfully reproduces previous analytic results. The proposed method is applicable to two cavities until they come into contact, thus providing a theoretical explanation of the fundamental collapse-and-merger process of two cavities. Furthermore, we extend this method to the interaction among multiple cavities, which reveals the effect on the flow field of an arbitrary number of cavities in an arbitrary configuration. To demonstrate the potential of the proposed method, we first apply it to a one-dimensional array of cavities of arbitrary orientation and curvature and estimate the convective diffusion of fluid volume, before considering a two-dimensional slightly disordered array of cavities. The results indicate the development and creation of new fluid passages, which may provide clues for predicting the anomalously fast spread of contaminants in inhomogeneous granular material; the formation of waterways, collapse of river banks, and landslides in civil engineering; and fluidization in chemical engineering. Our results may also provide insights into medical engineering techniques for creating new blood veins for micro-circulation (angiogenesis).
A hard energy spectrum in 3D guide-field magnetic reconnection
Authors: Hoshino Masahiro
Published: May 2024

Magnetic reconnection has long been known to be the most important mechanism not only for mixing the plasmas by changing the magnetic field topology but also for releasing the magnetic field energy into the plasma kinetic energy. During magnetic energy release, it is possible for some of the heated plasma to be accelerated to energies much higher than the thermal energy. Recently, the energy partitioning of the thermal and the nonthermal energy has been studied by using particle-in-cell (PIC) simulations, and it has been shown that the acceleration efficiency of nonthermal particles increases with increase in the plasma temperature, and the nonthermal energy density occupies more than 90% in the total heated plasma when the Alfvén velocity is close to the speed of light, c. However, the acceleration efficiency decreases as the guide magnetic field increases. So far, the acceleration efficiency has been mainly studied in two-dimensional systems, but it is interesting to study three-dimensional effects where the patchy and turbulent reconnection can dynamically occur. This study explores the effects of three-dimensional relativistic reconnection on a pair plasma with the guide magnetic field, utilizing three-dimensional (3D) PIC simulations. The results indicate that the decrease in nonthermal particle production is smaller in 3D guide-field reconnection compared to 2D. More importantly, contrary to general expectation, 3D reconnection is capable of maintaining a hard nonthermal energy spectrum even in the presence of a strong guide magnetic field.
Hysteresis in the gyrofluid resistive drift wave turbulence to zonal flow transition
Authors: Grander F. , Locker F. F. , Kendl A.
Published: May 2024

The classical drift-fluid (modified) Hasegawa–Wakatani model for quasi-three-dimensional resistive drift wave turbulence in magnetized plasmas is introduced into a gyrofluid model including consistent finite Larmor radius effects. The transition from a turbulence dominated to a strong zonal flow state through variation of the dissipative coupling strength is re-visited and characterized for warm ions. The resulting zonal flow states show a dependence on initial conditions and intermediate temporary changes of parameters, and feature characteristics of hysteresis, such as longer time scales for the decay of zonal flow states into turbulence than for the formation of flows out of turbulence. Zonal flows in warm ion plasmas are also shown to be able to spontaneously merge into flow states with smaller radial mode number and higher flow energy in simulations with long run times.
Effect of parameter optimization on the flow characteristics of venturi-self-excited oscillation mixer based on response surface model and multi-island genetic algorithm
Authors: Nie Songlin , Zhang Jinli , Hong Ruidong , Ji Hui , Ji Haidong
Published: May 2024

The present study focuses on the development of a novel venturi-based self-excited oscillation mixer that effectively utilizes the venturi effect to facilitate efficient abrasive intake while simultaneously ensuring effective prevention of backflow through the utilization of the systolic section within the venturi tube. It not only ensures uniform mixing of water and abrasive but also transforms the continuous jet into a pulsed one, thereby significantly enhancing exit velocity. The orthogonal experimental design method and single factor experiment method were employed to investigate the effects of inlet water pressure, water nozzle diameter, abrasive inlet angle, aspect ratio of the self-excited oscillation mixer, and abrasive pipe inlet diameter on the inlet pressure of the abrasive pipe and the velocity of the jet exit in the new mixing device. Approximate response surface models for these parameters were constructed using lsight optimization software, combining the results of orthogonal experimental simulation. By employing a multi-island genetic algorithm, we have globally optimized this innovative mixing device to determine its optimal performance parameters. Subsequently, comparative experiments were conducted to validate the performance of different mixing devices in descaling applications. Through experimental verification, it was found that the venturi-self-excited oscillation mixer exhibits excellent rust removal capabilities in steel plate tests compared to traditional self-excited oscillation mixers. These findings provide valuable guidance for the subsequent design and enhancement of abrasive water jet mixers.
Comprehensive evaluation of coal burst risk using optimized linear weighted model
Authors: Jiang Chunlin , Li Xuelong , Wang Feng , Wang Rui
Published: May 2024

The assessment of coal burst risk is a complex and systematic process; the variations among the indicator systems and the stability of the evaluation models used can influence the results. In this study, an index system for the analytic hierarchy process was constructed based on 21 geomechanically influential factors on rock bursts. The multi-weight combination optimization model was used to synthesize the subjective weights derived by the four experts using AHP and the objective weights derived through the inter-criteria correlation method to obtain the unique optimization weights. After normalizing the original evaluation data, the Gram–Schmidt orthogonalization method was employed to eliminate correlations among factors. The optimized factor weights and data were subsequently input into a linearly weighted comprehensive evaluation model to determine the coal burst risk. The proposed method was applied to assess the coal burst risk of a coal seam in the Liang Jia Coal Mine. These results align with those of the actual coal mine scenario. Indeed, the proposed linear weighted comprehensive evaluation model provided enhanced accuracy and reliability with improved practicality compared to previously proposed methods.
Investigation of two patterns of vortex-induced vibration in a 5:1 rectangular section under different parameters
Authors: Wang Jiaying , Wang Feng , Xing Feng , Zheng Xiaodong , Li Jiawu , Zhang Jiupeng , Huang Xiaoming
Published: May 2024

In this study, a 5:1 rectangular section was taken as the research object. An aerodynamic reduced-order model was used to verify whether the rectangular section had a similar oscillation mechanism to a circular section based on the results of two-dimensional unsteady Reynolds-averaged Navier–Stokes calculations. Computational fluid dynamics was used to study the vertical oscillation characteristics of the 5:1 rectangular section under the influence of different parameters. The results showed that the vertical oscillation of the rectangular section could be divided into two patterns according to the oscillation characteristics: “resonance-induced vibration” and “competition-induced vibration.” The resonance-induced vibration shows a quick development in amplitude, while competition-induced vibration has two stages before stabilization. The vibration amplitude, oscillation frequency, and lock-in region were affected by variations in the mass ratio. The damping ratio had less effect on the oscillation frequency and vibration amplitude than the mass ratio. However, a reduction in the damping ratio enlarged the lock-in region at a high reduced velocity. Additionally, the difference in the initial displacement had a considerable influence on the vibration amplitude of competition-induced vibration, while it had little effect on resonance-induced vibration.
Generation of localized, half-frequency spin waves in micron sized ferromagnetic stripes: Experiments and simulations
Authors: Copus M. G. , Hula T. , Heins C. , Flacke L. , Weiler M. , Schultheiss K. , Schultheiss H. , Camley R. E.
Published: May 2024

We demonstrate the nonlinear generation of spin-wave edge modes with half the frequency of the applied oscillating field in a Co25Fe75 ferromagnetic stripe through micromagnetic simulations and experiments. The generation of half-frequency modes depends on the simultaneous presence of resonances near both the driving frequency and the half-frequency in different regions of the material. The half-frequency generation occurs in a system that is thin enough that typical three-magnon decay would not be allowed in a ferromagnetic resonance experiment in an extended film. We find that a limited range of driving frequencies will produce a half-frequency for a given set of system parameters. This range can be tuned by the strength of the oscillating field and the strength of the static external field. Our experimental results agree well with the findings from the simulations.
Milk yield and feeding behaviour responses to two flat-rate levels of concentrate supplementation fed over a period of 8 months to cohorts of grazing dairy cows, differing in genotype, bodyweight, or milk yield
Authors: Raedts Pieter J. M. , Hills James L.
Published: May 2024

Context In most pasture-based herds in Australia, supplementation with concentrates is normally a flat rate, with quantities determined by average cow requirements, rather than individual-cow requirements. Comparisons between flat rate and individual feeding rarely show advantages such as milk yield benefits for either. However, in pasture-based systems little is understood regarding milk production responses or levels of pasture substitution, when different groups of cows within the herd are fed concentrates at higher supplementation levels. Aims To investigate the effect on milk yield, feeding time, and ruminating time, of two flat-rate supplementation levels of concentrate, fed over 8 months to 180 cows selected for one of three different parameters. Methods Cohorts of cows were selected on contrasting differences for either milk production at the start of lactation, bodyweight, or genotype. Each cohort was divided into two balanced groups receiving either 2 or 6 kg DM/cow.day of concentrate, from approximately 12 days in milk onward. All cows remained part of the main milking herd (total herd size 320 spring-calving cows), with a similar opportunity for all cows to graze pasture or feed on supplemented grass silage during periods of pasture shortage. Milk yield was recorded at each milking and feeding behaviour continuously recorded by MooMonitor+ collars. Results were analysed for three seasonal periods of 10, 12 and 10 weeks (P1, P2 and P3 respectively) commencing in spring. Key results Mean marginal milk response (L milk per 1 kg DM extra of concentrate) over the trial period was 0.88 L, increasing from 0.71 L in P1, to 0.92 L in P2 and 1.03 L in P3. The high-concentrate cohorts recorded reduced feeding time per day of 37 min overall (46, 35 and 29 min for P1, P2 and P3 respectively). Significant differences were found for milk yield and feeding time between several contrasting cohorts. The lowest marginal milk response was for cross-breed cows in P1 with 0.18 L and feeding reduced by 65 min/cow.day, with the contrasting cohort of Friesian cows at a larger marginal response of 0.94 L and smaller feeding time reduction of 32 min/cow.day. Conclusions The differences among cohorts demonstrated potential for targeted concentrate feeding to specific groups of cows that respond differently in marginal milk yield and grazing behaviour. Implications When a significant change is made in strategic amounts of concentrate feeding, the impact not only on marginal milk response should be considered, but also on pasture intake.
Translocation of YopJ family effector proteins through the VirB/VirD4 T4SS of
Bartonella
Authors: Fromm Katja , Ortelli Monica , Boegli Alexandra , Dehio Christoph
Published: May 2024

The evolutionary conserved YopJ family comprises numerous type-III-secretion system (T3SS) effectors of diverse mammalian and plant pathogens that acetylate host proteins to dampen immune responses. Acetylation is mediated by a central acetyltransferase domain that is flanked by conserved regulatory sequences, while a nonconserved N-terminal extension encodes the T3SS-specific translocation signal.
Bartonella
spp. are facultative-intracellular pathogens causing intraerythrocytic bacteremia in their mammalian reservoirs and diverse disease manifestations in incidentally infected humans. Bartonellae do not encode a T3SS, but most species possess a type-IV-secretion system (T4SS) to translocate
Bartonella
effector proteins (Beps) into host cells. Here we report that the YopJ homologs present in Bartonellae species represent genuine T4SS effectors. Like YopJ family T3SS effectors of mammalian pathogens, the “
Bartonella
YopJ-like effector A” (ByeA) of
Bartonella taylorii
also targets MAP kinase signaling to dampen proinflammatory responses, however, translocation depends on a functional T4SS. A split NanoLuc luciferase-based translocation assay identified sequences required for T4SS-dependent translocation in conserved regulatory regions at the C-terminus and proximal to the N-terminus of ByeA. The T3SS effectors YopP from
Yersinia enterocolitica
and AvrA from
Salmonella
Typhimurium were also translocated via the
Bartonella
T4SS, while ByeA was not translocated via the
Yersinia
T3SS. Our data suggest that YopJ family T3SS effectors may have evolved from an ancestral T4SS effector, such as ByeA of
Bartonella
. In this evolutionary scenario, the signal for T4SS-dependent translocation encoded by N- and C-terminal sequences remained functional in the derived T3SS effectors due to the essential role these sequences coincidentally play in regulating acetyltransferase activity.