bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of a prototype of monitor for alpha and beta radiation in water using new silicone-based contamination-safe detectors
Authors: Lunardon Marcello , Sartori Paolo , De Felice Pierino , Stevanato Luca
Published: November 2023

We present here the main results of an experimental activity aimed at the realization of a prototype of monitor for alpha and beta radioactivity in water exploiting a novel type of contamination-safe scintillation detector developed by our research group.

Due to the short path-length of alpha and beta particles in water and the low detection limits needed to be compliant with the international legislations in matter of radiation safety for water, the detectors to be used for such a kind of instruments should have in general large area, very low intrinsic background and avoid any kind of window between the monitored water and the active volume of the detector. Even an extremely low contamination of the surface can therefore destroy the detector performance, while protecting the detector with a layer of passive material will reduce the detection efficiency, in particular for alpha particles, and the passive layer can get contaminated itself, making necessary its substitution and representing an important limitation to the realization of a radioactivity monitor that should work continuously for years.

The novel detectors are large-area silicone-based scintillators developed and produced in our laboratories. The technology we propose is a significant step forward in the direction of the realization of radioactivity monitors for water with high sensitivity and reasonable costs, to be used to improve security and quality of the water distributed to European and worldwide citizens.

The detection performance for alpha and beta particles was first tested in air with standard sources, showing results very close to similar detectors commercially available. Later a number of tests were carried out in the ENEA-INMRI laboratories with the aim to characterize the contamination and decontamination properties. Initial activity of each detector foil was checked by low background radioactivity measurements, then the detectors were immersed for fixed times and constant procedure in a variety of radioactive reference liquid solutions with different radionuclides in different chemical forms. After rinsing with distilled water the detector foils were again measured for residual radioactivity adsorbed on the foils surface.

After this preliminary campaign of contamination measurements carried out on small size samples, several large area detectors were realized and used to build a small demonstrator device for continuous monitoring of the radioactivity in water. The monitor was tested with distilled water (blank) and radioactive aqueous solutions, demonstrating the possibility to realize a new generation of radiation monitors for water with high sensitivity and with the possibility to easily manage the contamination issues.
Pulse shape discrimination of CLYC, CLLBC and EJ-276 with SiPM readout
Authors: Seitz Bjoern , Bennett David , Thomson Frank
Published: November 2023

Solid state detectors for the detection of thermal and fast neutrons find widespread applications. They often operate in a high gamma-radiation field or are required to discriminate between gamma-radiation and neutrons. Organic and in-organic scintillation materials are proposed as detector materials. These materials often exhibit different pulse shapes in their light output, which allows a variety of pulse shape analysis (PSA) techniques to be used to distinguish the two species of radiation. The current maturity of silicon based single photon counters (SiPM) provides a viable visible photon detector alternative to conventional vacuum based photo multiplier tubes (PMT). However, their impact on PSA has not been deeply studied. Three solid state scintillation materials, CLYC, CLLBC and EJ-276 are coupled to an array of SiPM and exposed to neutron and gamma radiation. Their response is characterized using a variety of PSA algorithms and quantified in a Figure of Merit. Conventional charge comparison algorithms perform well for all materials, while a Fourier component analysis shows particular strength for the in-organic materials tested.
Neutron imaging with Micromegas detectors with optical readout
Authors: Cools A. , Aune S. , Brunbauer F.M. , Benoit T. , Corsi A. , Ferrer-Ribas E. , Iguaz F.J. , Mazoin C. , Oliveri E. , Papaevangelou T. , Pollacco E.C. , Potignon M. , Ropelewski L. , Sari A.
Published: November 2023

Optical readout of Micromegas gaseous detectors has been achieved by implementing a Micromegas detector on a glass substrate with a glass anode and a CMOS camera. Efficient X-ray radio-graphy has been demonstrated due to the integrated imaging approach inherent to optical readout. High granularity values have been reached for low-energy X-rays from radioactive sources and X-ray generators taking advantage of image sensors with several megapixel resolution. Detector characterization under X-ray radiography opens the way to different applications from beta imaging to neutron radiography. Here we will focus on one application: neutron imaging for non-destructive examination of highly gamma-ray emitting objects. This article reports the characterization of the detectors when exposed to a low activity neutron source. The response of the detector to thermal neutrons has been studied with different field configurations and gap thicknesses.
Performance comparison of different SiPM arrays coupled to neutron-γ scintillators
Authors: Delgado Jessica , Pino Felix , Moretto Sandra , Corti Daniele , Griggio Alessandro , Pancheri Lucio , Fabris Daniela
Published: November 2023

The market for SiPMs has grown rapidly in recent years, driven by their increasing use in applications such as medical imaging, nuclear and particle physics. Due to the growing demand, many manufacturers are now offering SiPMs, each of them with unique features and performance characteristics. As a result, it is essential to conduct comparative studies to evaluate and compare the performance of different SiPM arrays. Therefore, this work aims to compare the performance of assembled detectors based on two different SiPM arrays (AdvanSiD-NUV hybrid array ASD-NUV4S-P-4x4TD 17 mm x17 mm and the MPPC Hamamatsu S14161-6050HS-04 25 mm x 25 mm) coupled to two organic scintillators, a liquid scintillator EJ-309 (50 mm diameter x 50 mm thickness) and a plastic scintillator EJ-276G (25 mm diameter x 25 mm thickness). The assessment of the performance was made in terms of their energy resolution, time resolution, and capability to discriminate between γ-rays and fast neutrons. The outcomes show that the Hamamatsu SiPM array performs better for all of the characteristics studied, with the best configuration being when it was coupled to the EJ-309 liquid scintillator, obtaining the lowest energy and time resolutions, (0.108±0.004) and (0.599 ± 0.004) ns respectively, and the highest Figure of Merit (2.04 ± 0.01). A good Figure of Merit value that ensures an effective discrimination between fast neutrons and γ-rays.
Design of a reliable numerical model of a plastic scintillation detector for beta spectrometry
Authors: Fleres L. , Venara J. , Cuozzo M. , Mahe C. , Fargier S. , El Haber E. , Carrel F.
Published: November 2023

The accurate measurement of beta emitters is of utmost importance in various fields, including environmental monitoring, radiation protection and dismantling and decommissioning (D&D) operations. Nondestructive measurement techniques are crucial as they enable assessments of radioactivity without causing further harm or releasing additional hazardous materials. Due to the limited range of beta particles in matter, their characterization requires measurements in contact with the source term. In this paper, we present a study on the performance evaluation of a plastic scintillation detector designed for in-situ beta spectrometry measurements. The MCNP6.2 numerical model of the detector is detailed in the measurement configuration with beta, gamma and internal conversion electrons emitting sources. The calibration process and Gaussian Energy Broadening (GEB) parameters evaluation are discussed. Comparisons between the MCNP6.2 simulations and experimental measurements are exposed, both for gamma and beta spectra. While the gamma-ray detector response shows good agreement, greater discrepancies are observed in the beta ray response. To shed light on these discrepancies, a sensitivity analysis considering various sources of uncertainties is planned for future work.
Evaluation of neutron-induced activation gamma-rays creation and transport in a LaBr3 inorganic scintillator with PHITS
Authors: Besnard-Vauterin C. , De Stefano R. , Amoyal G. , Schoepff V. , Angélique J.-C.
Published: November 2023

In the framework of its R&D activities to support the metal industry, the Laboratory for Integration of Systems and Technology of CEA Paris-Saclay started studies with the aim of characterizing scrap metal by means of neutron activation analysis. This involves irradiating samples of scrap metal with a pulsed-neutron source in order to determine the copper composition (mainly Cu-65 and Cu-63). In this scope, the use of a LaBr3 detector with an energy resolution of 14.6 keV at 661 keV is hereby investigated to carry out acquisitions during and between the irradiation pulses. As pointed out in literature, the LaBr3 inorganic scintillator might suffer some damage in a neutron-rich environment. Understanding the degradation of the energy resolution of such detector due to a high dose environment is essential to analyse the recorded signal. In this context, the work described in the present paper explores the coherent creation of neutron induced activation products as well as their respective delayed gamma rays in the quite well established LaBr3 inorganic scintillator by the mean of two steps Monte Carlo simulations performed first with the DCHAIN code, and secondly with the PHITS general purpose Monte Carlo particle transport code. Coherence was shown between neutron-induced activation gamma rays and the isotopes created in the crystal, and between the isotopes created and their decay through time. Thus, this study validate the two-step calculation scheme with PHITS and DCHAIN for both the time and energy aspects.
Fast timing detectors for the muon system of a muon collider experiment
Authors: Aimè C. , Calzaferri S. , Fiorina D. , Riccardi C. , Salvini P. , Vai I. , Vitulo P.
Published: November 2023

The muon collider offers a great discover potential for the future of high energy physics. Indeed, it combines the advantages of a lepton collider, with clean signatures and maximum available center of mass energy, with those of a hadron collider, such as low synchrotron radiation. However, it poses interesting challenges, manly related to the fact that muons decay and their product interact with the material of the machine producing the socalled Beam-induced-Background. For this reason, a careful design of the experiments running at a muon collider must be performed, starting from simulation, and moving to the R&D on dedicated technologies. This contribution will focus on the muon system of a muon collider experiment: the current design limitations will be presented, together with the alternative solutions that are being considered. In particular, we are proposing to use the Picosec Micromegas technology for a dedicated timing layer in the muon system, which will improve the muon reconstruction performance in that region. The R&D on this technology will be discussed and preliminary results will be presented.
The High Efficiency fast-Response GAmma (HERGA) detector based on SiPM readout
Authors: Altomare C. , Cerasole D. , Di Venere L. , Fanchini E. , Gargano F. , Giordano F. , Loparco F. , Loporchio S. , Mastroserio A. , Morichi M. , Pantaleo F.R. , Serini D. , Spinelli P. , Swiderski L.
Published: November 2023

Gamma-ray spectroscopy and gamma-ray imaging are two complementary techniques used for the localization and the identification of radioactive sources containing gamma-ray emitting radioisotopes. The radioactivity monitoring is focused on the detection of both artificial and environmental radioactive sources like Naturally Occurring Radioactive Materials (NORM). This kind of contamination becomes dangerous when the detection of the unwanted substances exhibits a concentration significantly above the environmental radioactive background radiation levels. For this purpose, we have developed, tested and shown a High Efficiency fast-Response GAmma (HERGA) detector useful for the identification of radionuclides and for gamma-ray imaging. A first version of the gamma detector prototype was composed of 16 CsI(Tl) scintillating crystals of 3x3x10 cm3 size, arranged in 4x4 matrix coupled with standard Photomultiplier tubes (PMTs). An image reconstruction of a radioactive gamma emitter source is possible using the coded mask technique, in which a 7x7 mask, made of Plastic and Tungsten tiles, is placed in front of the detector and a pattern recognition algorithm based on classical statistical methods (Kolmogorov Smirnov) is used to reconstruct the source position. The measurements carried out showed a point spread function (PSF) of a few mrad for pointlike sources. The Minimum Detectable Activity (MDA) was also determined in the case of pointlike radioactive sources. In this contribution we will present an update of the HERGA detector prototype in which Silicon Photomultipliers (SiPMs) are used in place of the PMTs. SiPMs provide similar or even better performance compared to the standard PMT sand provide benefits in terms of lower power consumption and reduced cost and compactness. The advantages of the SiPM technology are also characterized by the robustness of the photosensor that makes the new prototype compact, portable, ideal for in-situ and real-time. We will show a comparison between the results obtained with the newest SiPM read-out technology with respect to those obtained with the PMT one, in terms of energy and spatial resolution. The imaging performance is also in phase of testing in order to localize extended radioactive sources such as for example

NORM samples or to detect inaccessible or hidden nuclear waste.
Traumfabrik Physio: Wieder fit für den Film
Authors: Hügler Stephanie
Published: November 2023

Ein Kreuzbandriss drohte den Traum des Schauspielers Klaus Steinbacher zu zerstören. Gezielte Physiotherapie rettete ihn und seine Rolle als Franz Beckenbauer im Film „Der Kaiser“.
Sulfur-Mediated ipso-Cyclization of 4-(p-Methoxyaryl)alk-1-ynes Leading to 3-Thiospiro[4.5]deca-1,6,9-trien-8-ones
Authors: Li Pingfan , Han Meng
Published: November 2023

A new method for the intramolecular electrophilic ipso-cyclization of alkynes with triflic anhydride-activated sulfoxides, followed by demethylation with triethylamine in one pot, is described for the synthesis of 3-thiospiro[4.5]-decatrienones in moderate to good yields. This method provides a facile strategy for assembling the sulfur-substituted spirocyclic compounds.
Radial Midcarpal Instability Treated with Radioscaphocapitate Ligament Recession: A Case Report
Authors: Chin-Yi Liao Janice , Meng Kiat Tan David
Published: November 2023

Background Midcarpal instability is an uncommon entity characterized by pain and clunking as the wrist moves from radial deviation to ulnar deviation. Management is primarily nonoperative. In patients with persistent symptoms, operative treatments are divided into soft tissue reconstruction and limited midcarpal arthrodesis.

Case Description We present a rare case of radial midcarpal instability associated with radioscaphocapitate (RSC) ligament injury. A 20-year-old man presented with radial-sided wrist pain and clunking with radial deviation after a fall. Wrist arthroscopy confirmed the pathology of an RSC ligament injury resulting in an extended posture of the scaphoid and a catch-up clunk from sudden flexion of the scaphoid in radial deviation. His RSC ligament was recessed and he had excellent outcome at 1 year follow-up.

Literature Review Midcarpal instability was reported by Lichtman et al as a painful wrist click in ulnar deviation and classified according to the direction of the subluxation. Radial midcarpal instability was later described by Caputo et al in patients with rotatory subluxation of the scaphoid. We present a previously unreported form of radial midcarpal instability as it does not quite fit into the type III midcarpal instability with ligament laxity of the scaphotrapeziotrapezoid joint and type IV with scapholunate ligament disruption. The painful wrist click occurs in radial deviation as the result of an RSC ligament injury.

Clinical Relevance We performed arthroscopic thermal capsulorrhaphy of the ulnar arcuate ligaments and dorsal capsule and an open proximal recession of the RSC ligament. The elimination of pain and clunking accompanied by the restoration of scaphoid flexion and return to load-bearing activities validates the pathology and suggests the potential of this soft tissue procedure in the treatment of radial midcarpal instability.
Understanding and Addressing the Individualized Emotional Impact of Aphasia: A Framework for Speech-Language Pathologists
Authors: Harmon Tyson G.
Published: November 2023

Emotion plays an integral role in communication and has long been considered relevant to aphasia rehabilitation. Speech-language pathologists (SLPs), however, may sometimes wonder how or whether to address emotional responses. The purpose of this article was to (1) present a framework that clinicians can use to understand individualized emotional responses in aphasia and (2) discuss examples of how the framework informs practical strategies that SLPs can use to provide emotional support to people with aphasia (PWA). Drawing upon a cognitive–motivational–relational theory of emotions perspective combined with emerging research in aphasia, I show that emotion impacts and is impacted by both language processing and social participation, but this impact should be interpreted in light of individual variability. Personal characteristics, environmental conditions, and cognitive appraisal, considered within a specific cultural context, help account for individualized emotional responses. SLPs should consider interactions among emotional response, language processing, and social participation in aphasia while recognizing each person's unique perception of the situation and resources to cope with it. Additionally, the presented framework provides insights about how SLPs could offer emotional support to PWA. Specific examples related to harnessing situational demands to improve communication, employing active listening, facilitating reappraisal, and strengthening social support are discussed.
Association between Sleep Quality and Cardiac Autonomic Modulation in Adolescents: A Cross Sectional Study
Authors: Lins-Filho Ozeas de Lima , Andrade-Lima Aluisio , Torres Auguste Daniel , Oliveira Luciano Machado , Luiz do-Prado Wagner , Ritti-Dias Raphael , Christofaro Diego Giulliano Destro , Farah Breno Quintella
Published: November 2023

Objective To analyze the impact of sleep quality/duration on cardiac autonomic modulation on physically active adolescents with obesity.

Materials and Methods The present cross-sectional study included 1,150 boys with a mean age of 16.6 ± 1.2 years. The assessment of cardiac functions included the frequency domain of heart rate variability (HRV; low frequency – LF; high frequency – HF; and the ratio between these bands –LF/HF –, defined as the sympathovagal balance), and each parameter was categorized as low/high. Physical activity levels and sleep quality/duration were obtained by questionnaires. Abdominal obesity was assessed and defined as waist circumference > 80th percentile.

Results Poor sleep quality resulted in lower HF (odds ratio [OR]: 1.8; 95% confidence interval [95%CI]: 1.01–3.21]) regardless of physical activity and abdominal obesity. Moreover, the study found no association between sleep duration and HRV parameters in adolescents.

Conclusion Sleep quality, not sleep duration, reduces parasympathetic cardiac modulation apart from other factors such as physical activity and abdominal obesity in adolescents.
Performance of the NOSE Questionnaire in Mask Selection for Home CPAP Titration
Authors: Blanco Magalí , Ernst Glenda , Rabino Alberto , Salvado Alejandro , Borsini Eduardo Enrique
Published: November 2023

Introduction Many patients abandon CPAP treatment because they find the mask uncomfortable. Therefore, specialists may benefit from the predictive value of airway assessment tools.

Objective To identify nasal ventilation failure through the Nasal Obstruction Symptom Evaluation (NOSE) scale in patients with obstructive sleep apnea (OSA) who undergo home-based auto-adjusting CPAP titration and to determine whether there is a correlation between NOSE score and the type of mask selected.

Materials and Methods In this prospective correlational study, the NOSE scale was used in terms of mask selection and titration indicators. Patients were classified based on their NOSE score: > or < 50.

Results We included 303 patients; 226 men (74.5%), BMI: 33.2 ± 6.1 kg/m2, neck circumference (cm): 42.8 ± 3.6 and Epworth (ESS) score: 9.2 ± 5.6, mild OSA: 12 (3.9%), moderate OSA: 127 (41.9%), and severe OSA: 164 (54.1%). The mean NOSE score was 24.3 ± 22.8 and 42 patients (13.8%) had NOSE scores > 50. Indicators for both groups were: compliance (5.9 ± 1.3 vs. 5.8 ± 1.4 hours) p: 0.41, therapeutic pressure (9.1 ± 2.0 vs. 8.8 ± 1.6 cm of H2O) p: 0.23, residual AHI (2.3 ± 1.8 vs. 2.8 ± 2.6 events/hour) p: 0.25, and leaks (20.5 ± 10.6 vs. 21.3 ± 10.7 liters/minute) p: 0.64. According to adjusted multiple regression, a NOSE of > 50 was not a predictor of mask selection.

Conclusions A > 50 NOSE score was not a predictor of mask selection, and it was not correlated to titration performance.
Clinical Application of the Multicomponent Grading System for Sleep Apnea Classification and Incident Cardiovascular Mortality
Authors: Jorquera Jorge , Dreyse Jorge , Salas Constanza , Letelier Francisca , Weissglas Bunio , Del-Río Javiera , Henríquez-Beltrán Mario , Labarca Gonzalo , Jorquera-Díaz Jorge
Published: November 2023

Objective To evaluate the clinical utility of the Baveno classification in predicting incident cardiovascular mortality after five years of follow-up in a clinic-based cohort of patients with obstructive sleep apnea (OSA).

Materials and Methods We evaluated the reproducibility of the Baveno classification using data from the Santiago Obstructive Sleep Apnea (SantOSA) study. The groups were labeled Baveno A (minor symptoms and comorbidities), B (severe symptoms and minor comorbidities), C (minor symptoms and severe comorbidities), and D (severe symptoms and comorbidities). Within-group comparisons were performed using analysis of variance (ANOVA) and post hoc tests. The associations between groups and incident cardiovascular mortality were determined through the Mantel-Cox and Cox proportional hazard ratios (HRs) adjusted by covariables.

Results A total of 1,300 OSA patients were included (Baveno A: 27.7%; B: 28%; C: 16.8%; and D: 27.5%). The follow-up was of 5.4 years. Compared to Baveno A, the fully-adjusted risk of cardiovascular mortality with Baveno B presented an HR of 1.38 (95% confidence interval [95%CI]: 0.14–13.5; p = 0.78); with Baveno C, it was of 1.71 (95%CI: 0.18–16.2; p = 0.63); and, with Baveno D, of 1.04 (95%CI: 0.12–9.2; p = 0.98). We found no interactions involving Baveno group, sex and OSA severity.

Discussion Among OSA patients, the Baveno classification can describe different subgroups. However, its utility in identifying incident cardiovascular mortality is unclear. Long-term follow-up studies and the inclusion of demographic variables in the classification could improve its ability to detect a high-risk phenotype associated with cardiovascular mortality.

Conclusion The Baveno classification serves as a valuable method for categorizing varying groups of patients afflicted with OSA. Nevertheless, its precision in identifying occurrence of cardiovascular mortality is still unclear.
Considerations in Forehead Reduction for Men
Authors: Núñez-Castañeda José Miguel , Chang-Grozo Silvana Lucia
Published: November 2023

Although frontal prominence is an infrequent benign defect that causes no sequelae, it gives the patient distress due to its unaesthetic visual aspect. Proper surgical recontouring of the forehead can radically change one's appearance. In consequence, different techniques have been proposed for its management and correction. The aim of this study is to describe a surgical algorithm to treat male patients with forehead reduction to soften the “forceful” look. An observational cross-sectional study was conducted at the head and neck surgery ward of a general hospital between 2019 and 2022. We performed 35 forehead reduction operations on male patients. The median age was 29 years (range, 26–32 years). The forehead reduction procedures performed was categorized as follows: 27 anterior table osteotomy and 8 anterior table osteotomy contouring. Median forehead reduction was 2.7 mm (range, 2–3.2 mm). The average medical follow-up for patients was 6 months, with an interval ranging from 4 to 8 months. Surgery of the forehead in properly selected male patients is sufficiently safe that it can be done for entirely aesthetic reasons. The choice of surgical technique depends on the presence or absence of the pneumatized frontal sinus. If the frontal sinus is not pneumatized, an anterior table contouring is performed and if the frontal sinus is pneumatized, an anterior table osteotomy is preferred.
Vietnamese online media leaders’ and citizens’ perspectives on Vietnam-US relations
Authors: Nguyễn Anh Cường
Published: November 2023

After more than 26 years since the normalization of Vietnam-US relations, cooperation in all fields, including the most sensitive ones, such as military, security, and politics, has significantly advanced. Moreover, the political beliefs of the people and governments of the two nations have at least partially converged. Therefore, it is time for Vietnam to consider the United States’ proposal to elevate their relationship from a comprehensive partnership (2013) to a strategic one. Using qualitative and quantitative methodologies through content analysis, we first focus on particular areas of cooperation between the two countries, especially in development, and clarify the policies and desires to deepen collaboration and relations from both sides. The paper then evaluates Vietnamese public opinion regarding Vietnam-US relations by analyzing online articles in Vietnam. However, it is noteworthy that the announcement made on September 10, 2023, by the respective top leaders of the United States, President Joe Biden, and the Communist Party of Vietnam, General Secretary Nguyen Phu Trong, regarding the elevation of Vietnam-US relations to the utmost level of comprehensive strategic partnership, bypassing the intermediate stage of a strategic partner, has indeed surpassed the anticipations of the Vietnamese populace. Contrarily, this phenomenon can be considered commonplace when examining the escalating dynamics of support from political leaders and the general populace toward Vietnam-US relations.
Numerical simulations of suspensions of rigid spheres in shear-thinning viscoelastic fluids
Authors: Ayar O. , Fernandes C. , Ferrás L. L. , Alves M. A.
Published: November 2023

In multiphase flows, accurately modeling the interaction between the liquid phase of complex fluids and a porous medium of solid spheres poses a fundamental challenge. The dynamics of moderately dense non-colloidal suspensions constituted by static random arrays of mono-disperse spherical particles in non-linear viscoelastic fluids is studied numerically. This numerical study consists of about 9000 different systems, in which the volume fraction ϕ (0.04≤ϕ≤0.2) of the dispersed solid phase, the Reynolds number Re(5≤Re≤50), the solvent viscosity ratio β(0.05≤β≤0.9), the Weissenberg number Wi(0.5≤Wi≤4), and the mobility parameter of the Giesekus model α (0.1≤α≤0.5) were varied to understand the particle's interactions with the viscoelastic suspending fluid. We aim to investigate the relationship between the volume fraction of the dispersed solid phase and the non-linear rheology of shear-thinning viscoelastic fluids with the normalized average drag force ⟨F⟩. In addition, by assessing the flow patterns predicted numerically, we were able to provide a characterization of the velocity and stress fields as a function of the simulation parameters.
Charge state transition levels of Ni in β-Ga2O3 crystals from experiment and theory: An attractive candidate for compensation doping
Authors: Seyidov Palvan , Varley Joel B. , Shen Jimmy-Xuan , Galazka Zbigniew , Chou Ta-Shun , Popp Andreas , Albrecht Martin , Irmscher Klaus , Fiedler Andreas
Published: November 2023

Nickel-doped β-Ga2O3 crystals were investigated by optical absorption and photoconductivity, revealing Ni-related deep levels. The photoconductivity spectra were fitted using the phenomenological Kopylov and Pikhtin model to identify the energy of the zero-phonon transition (thermal ionization), Franck–Condon shift, and effective phonon energy. The resulting values are compared with the predicted ones by first-principle calculations based on the density functional theory (DFT). An acceptor level (0/−) of 1.9 eV and a donor level (+/0) of 1.1 eV above the valence band minimum are consistently determined for NiGa, which preferentially incorporates on the octahedrally coordinated Ga site. Temperature-dependent resistivity measurements yield a thermal activation energy of ∼2.0 eV that agrees well with the determined Ni acceptor level. Conclusively, Ni is an eminently suitable candidate for compensation doping for producing semi-insulating β-Ga2O3 substrates due to the position of the acceptor level (below and close to the mid-bandgap).
Nonreciprocity and chirality hosted by ferromagnetic helical chains: Heat generation vs spin filtering
Authors: Zhang Lin , Tang Yuxin , Zhai Guangwei , Jiang Feng , Zhu Yanyan , Yan Yonghong
Published: November 2023

Motivated by the booming development of spintronics based on chiral helical microstructures, we employed the standard nonequilibrium Green’s function theory to study nonreciprocity and chirality of the heat generation and spin filtering in ferromagnetic helical chains. Our results demonstrate that magnetization, spin–orbit interaction, and nonstep electrostatic potential distribution by bias jointly determine nonreciprocity of the heat generation, and only spin–orbit interaction determines nonreciprocity of the spin-polarized current. Chirality of the heat generation and spin-polarized current is determined by both magnetization and spin–orbit interaction, and some quantitative relationships related to chirality were discovered. However, a transverse field can break these relations and suppress heat generation significantly and modulate nonreciprocity and chirality of the spin-polarized current effectively. By further simulating the critical electrostatic potential distribution, we found with the transverse field applied, compared to the case with zero temperature, that the finite temperature less than one characteristic phonon energy can suppress nonreciprocity of the heat generation while enhancing that of the spin filtering. In terms of chirality, compared to the left-handed helical structure, the right-handed one is more advantageous for designing spin filtering diodes.
Age-dependent seasonal growth cessation in
Populus
Authors: Liao Xiaoli , Su Yunjie , Klintenäs Maria , Li Yue , Sane Shashank , Wu Zhihao , Chen Qihui , Zhang Bo , Nilsson Ove , Ding Jihua
Published: November 2023

In temperate and boreal regions, perennial plants adapt their annual growth cycle to the change of seasons. In natural forests, juvenile seedlings usually display longer growth seasons compared to adult trees to ensure their establishment and survival under canopy shade. However, how trees adjust their annual growth according to their age is not known. In this study, we show that age-dependent seasonal growth cessation is genetically controlled and found that the
miR156-SPL3/5
module, a key regulon of vegetative phase change (VPC), also triggers age-dependent growth cessation in
Populus
trees. We show that
miR156
promotes shoot elongation during vegetative growth, and its targets
SPL3/5s
function in the same pathway but as repressors. We find that the
miR156-SPL3/5s
regulon controls growth cessation in both leaves and shoot apices and through multiple pathways, but with a different mechanism compared to how the
miR156-SPL
regulon controls VPC in annual plants. Taken together, our results reveal an age-dependent genetic network in mediating seasonal growth cessation, a key phenological process in the climate adaptation of perennial trees.
Electronic effects on radiation damage in α-iron: A molecular dynamics study
Authors: Jiang 江 Lin 林 , Li 李 Min 敏 , Fu 付 Bao-Qin 宝勤 , Cui 崔 Jie-Chao 节超 , Hou 侯 Qing 氢
Published: November 2023

Iron (Fe)-based alloys, which have been widely used as structural materials in nuclear reactors, can significantly change their microstructure properties and macroscopic properties under high flux neutron irradiation during operation, thus, the problems associated with the safe operation of nuclear reactors have been put forward naturally. In this work, a molecular dynamics simulation approach combined with electronic effects is developed for investigating the primary radiation damage process in α-Fe. Specifically, the influence of electronic effects on the collision cascade in Fe is systematically evaluated based on two commonly used interatomic potentials for Fe. The simulation results reveal that both electronic stopping (ES) and electron–phonon coupling (EPC) can contribute to the decrease of the number of defects in the thermal spike phase. The application of ES reduces the number of residual defects after the cascade evolution, whereas EPC has a reverse effect. The introduction of electronic effects promotes the formation of the dispersive subcascade: ES significantly changes the geometry of the damaged region in the thermal spike phase, whereas EPC mainly reduces the extent of the damaged region. Furthermore, the incorporation of electronic effects effectively mitigates discrepancies in simulation outcomes when using different interatomic potentials.
Analysis of data for γp → f
1(1285)p photoproduction*
Authors: Wang 王 Ai-Chao 爱超 , Wei 韦 Neng-Chang 能昌 , Huang 黄 Fei 飞
Published: November 2023

The photoproduction of the

meson off the proton target is investigated within an effective Lagrangian approach. The t-channel ρ- and ω-exchange diagrams, u-channel nucleon-exchange diagram, generalized contact term, and s-channel pole diagrams of the nucleon and a minimal number of nucleon resonances are taken into account in constructing the reaction amplitudes to describe the experimental data. Three different models, that is, the Feynman, Regge, and interpolated Regge models, are employed, where the t-channel reaction amplitudes are constructed in Feynman, Regge, and interpolated Regge types, respectively. The results show that neither the Feynman model with two nucleon resonances nor the interpolated Regge model with one nucleon resonance can satisfactorily reproduce the available data for

. Nevertheless, in the Regge model, when any one of the

,

,

,

,

,

,

,

, and

resonances is considered, the data can be well described. The resulting resonance parameters are consistent with those advocated in the Particle Data Group (PDG) review. Further analysis shows that, in the high-energy region, the peaks of

differential cross sections at forward angles are dominated by the contributions from t-channel ρ- and ω-exchange diagrams, while in low-energy region, the s-channel pole diagrams of resonances also provide significant contributions to the

cross sections.
Attentive Simple Recurrent Unit Knowledge Tracing Based on Learning Ability
Authors: Fan Feifan , Xiahou Jianbing , Lin Fan
Published: November 2023

Knowledge tracing can analyze the current knowledge level of students through the data of students’ previous learning activities. However, the existing models usually consider the features of exercises, ignoring the individual differences of students. It is difficult to accurately predict students’ mastery. In this paper, we propose an attentive simple recurrent unit knowledge tracing (SRU-MAKT) based on learning ability. The experimental results show that our model is superior to the existing models, and the AUC increases by 1.6%. We also conduct visualization experiments, which show that SRU-MAKT has interpretability.
Collaborative Disturbance Rejection Voltage Control Technology for Distribution Stations under Distributed Resource Coordination
Authors: Xia Lei , Liu Zhong , Zhou Guozheng , Zhao Peizhi , Yang Lin
Published: November 2023

In order to improve the stability of the voltage in the distribution system, a distributed resource coordination-based coordinated anti-interference voltage control technology for distribution stations is proposed. The study analyzes the anti-interference capabilities of different types of renewable energy, energy storage, electric vehicles, and control distributed photovoltaic grid-connected inverters based on the analysis results. The objective function and constraints of voltage control are set. Voltage control is performed by adjusting the photovoltaic inverter and reactive power compensation device. The experimental results show that the proposed method can achieve stable control of system voltage under both photovoltaic output fluctuations and load fluctuations, indicating that its control effect is good.
Chemical Process Fault Diagnosis Method Based on Deep Learning
Authors: Zhang Han , Xu Bing
Published: November 2023

To address the problem that the traditional fault diagnosis method for chemical processes under big data relies too much on expert experience and fault features are difficult to distinguish, a deep learning-based fault diagnosis method is proposed, which combines convolutional neural network (CNN), long and short-term memory (LSTM) and attention mechanism (AM). In this method, the spatial sequence features of the input signal are extracted by the CNN adaptively, while the LSTM extracts the time-series features of the signal. Finally, the model performance is enhanced by introducing the attention mechanism and using the SoftMax layer as a classifier for fault diagnosis, so that the model can notice the important features of the faults with the interference of noise. Simulation validation of the method in this paper is performed using the TE chemical process data set, and it is demonstrated that the method can be used for chemical process fault diagnosis studies. Finally, compared with other fault diagnosis methods, the method is more accurate and has certain superiority.
Detection of Pine Wood Nematode Infestation Based on Improved YOLOv5
Authors: Miao Jiaming , Zhang Chunhui , Yuan Mengfei , Gu Shenming
Published: November 2023

Pine wilt disease is a destructive forest disease caused by the parasitism of pine wood nematodes inside pine trees. Once infected, pine trees quickly wither and die due to the inability to drain water, hence it is also known as pine tree withering disease. It is mainly spread by pine sawyer beetles, with the characteristics of fast dissemination, rapid onset, and high mortality rate, making it a significant global plant disease. Failure to effectively control the pine wilt disease in a timely manner will result in the massive death of pine trees in a short period of time in forest areas. With the continuous development and popularization of artificial intelligence and UAV (Unmanned Aerial Vehicle) technology, combining various methods can timely detect diseased trees, and performing timely treatment and protection can greatly save the time and personnel costs of biological pest control. While it is also conducive to promoting the work of multiple related disciplines, such as bioengineering and greening engineering. In this paper, we first conducted a large number of aerial surveys on the forest area through UAV, collected relevant data, and preprocessed the obtained data, including data augmentation, cleaning, filtering, deduplication, formatting, etc., to ensure data quality and accuracy. Then, we labeled the data, and made certain improvements to the original YOLOv5. We added a new RRAM (Recurrent Residual Attention Module) to the original network model, which enables the network to timely focus on important information in redundant data, thus improving the network’s performance. Compared with the original YOLOv5, our network has a stronger performance.
Algorithm for Detecting Small Targets Based on Upgraded YOLOv5s
Authors: Tian Chengjun , Liu Haobo , Liu Zhe , Yan Yu , Zhang Jintong
Published: November 2023

Small targets are discovered despite the challenges posed by the limited number of features, low resolution, difficulty in extracting discriminative characteristics, and ease of interference from external influences. A modest target detection technique based on enhanced YOLOv5s is suggested in this research. First, a test storey dedicated to tiny objects is appended to the characteristic fusion part of the algorithm to help the model efficiently acquire features with smaller sensory fields; second, to help the model find features more correctly, a cooperative attention method module is integrated into the characteristic extraction section to eliminate trait redundancy without sacrificing feature information; finally, the Bi-FPN network construction is combined to help the model to locate features more accurately. With the Bi-FPN construction, the characteristic combination process is modified to strengthen the examining capability of small objectives with a characteristic combination. The experimental results demonstrate that the enhanced algorithm increases average detection accuracy over the baseline YOLOv5s method by 6.3%, while also increasing small target detection accuracy and decreasing false and missed detection situations.
The improved quantum genetic algorithm with its application in fault diagnosis
Authors: Xiang Hao
Published: November 2023

In this paper, by analyzing the characteristics of the simulated annealing algorithm (SA) and the real double-chain coding target gradient quantum genetic algorithm (DCQGA), the real double-chain coding target gradient quantum genetic simulated annealing algorithm (DCQGSAA) is proposed. Because the performance of LSSVR is extraordinarily sensitive to its key parameters, the proposed algorithm is used to optimize these parameters, then a hybrid non-parametric prediction model is put forward. This model is used in fault prediction of liquid rocket engine thrust. The simulation results show that the proposed model is effective for small samples and multi-dimensional fault prediction.
The expansion of global LNG trade and its implications for CH4 emissions mitigation
Authors: Gao SiJia , Zhang GuoSheng , Guan ChengHe , Mao HaoRan , Zhang Bo , Liu He
Published: November 2023

In recent years, the global trade in liquefied natural gas (LNG) has experienced significant growth, leading to a rise in the effect of embodied methane (CH4) emissions between economies. This study investigates the spatiotemporal evolution of these CH4 emissions embodied within the global LNG trade and examines the associated network characteristics between the years 2011 and 2021. The findings reveal a substantial increase of 43.3% CH4 emissions embodied in global LNG trade, reaching a peak of 2.75 Tg in 2021, which equates to a monetary value exceeding 5 billion USD in terms of natural gas. Over the study period, these emissions aggregated to a total of 1987.92 Mt CO2-eq and 718.06 Mt CO2-eq, based on the respective global warming potential values over 20 year and 100 year timeframes. Our investigation of this complex network reveals the emergence of multiple robust hub economies, which have exerted significant influence over the dynamics of supply-demand in embodied CH4 trade, as well as the structure of trade communities. Notably, the Asia-Pacific trading community has exhibited exceptional growth and prominence in this market. Such growth is directly related to an increase in embodied CH4 emissions and their overall standing within this community’s network. The US has steadily attained dominance within an export-oriented community, which encompasses economies in South and North America, as well as certain regions of Europe. Moreover, the redistribution of LNG-related CH4 emissions among economies is significantly impacted by the intensity of production emissions and the volume of LNG trade. This reveals the potential of these hub economies to drive substantial reductions in CH4 emissions by implementing targeted energy and climate policies, which they have launched. Reinforcing coalitions and fostering closer collaboration within these communities can provide a robust foundation for technological advancements and transformative changes in trade structures.
Novel fluorescence approach for trace quantification of levonorgestrel in breast milk based on click reaction with benzonitrofurazan azide (NBD-AZ)
Authors: Aref Heba A , Salama Ismail , Aboukhatwa Shaimaa Mohamed , Helal Mohamed A , Kishk Safaa M , Elgawish Mohamed Saleh
Published: November 2023

Although the great importance of oral contraceptive agents in birth control, their existence in breast milk became a cause for concern, since infant exposure to these hormones is associated with many health problems. Consequentially, developing a sensitive bioanalytical method for monitoring their concentrations in breast milk is an urgent demand to examine the safety or the risk of these compounds on infants. Levonorgestrel is one of the most common contraceptive hormones under concern. Despite the high sensitivity of the fluorometric methods, detection of Levonorgestrel by them is confined because its structure does not exhibit any fluorescence. For the first time, we proposed a promising click fluorescent probe, 4-azido-7-nitrobenzoxadiazole to react with the alkyne group of Levonorgestrel, to give a highly fluorescent triazole derivative that exhibited strong signal at wavelength of 544 nm after excitation at 470 nm. Reaction parameters impacting the fluorescence were cautiously studied and optimized. The suggested approach has been successfully applied in Levonorgestrel estimation in breast milk samples with linearity of (0.4–80 ng.ml−1) and low detection limit of 0.12 ng.ml−1 without interferences from any biological components and with mean % recovery of 97.84 ± 2.73. Accuracy, sensitivity, selectivity, simplicity, and low-cost makes this approach a convincing, promising, and appealing alternative over reported analytical methods for Levonorgestrel bioanalysis in different matrices.