bluuebunny/crossref_metadata_2025 huggingface dataset:
Using low-temperature growth to resolve the composition pulling effect of UV-C LEDs
Authors: Yoshikawa Akira , Zhang Ziyi , Kushimoto Maki , Aoto Koji , Sasaoka Chiaki , Amano Hiroshi
Published: November 2023

One approach to improving the output power of ultraviolet (UV-C) light-emitting diodes (LEDs) is to adopt an electron-blocking layer (EBL) with a high barrier. However, the intended effect may not be realized because of the composition pulling effect, which is the unintended occurrence of a gradient layer at an AlGaN/AlGaN hetero-interface with substantial differences in the Al composition. Here, we demonstrate that low-temperature growth (i.e., <1000 °C) can be used to control the unintentional gradient layer at an AlN/AlGaN hetero-interface between a barrier layer and AlN-EBL with a difference in Al compositions of more than 30%. LEDs with an emission wavelength of 265 nm were fabricated, and an AlN-EBL was grown at low temperature to realize an abrupt interface. At an applied current of 100 mA, growing the EBL under low-temperature conditions improved the forward voltage by 0.5 V and remarkably improved the peak luminous intensity by 1.4–1.6 times. Our results can be used to realize UV-C LEDs with a steep EBL and further improve their device characteristics.
Alloy splitting of the FeGa acceptor level in dilute AlxGa1−xN
Authors: Kruszewski P. , Markevich V. P. , Peaker A. R. , Plesiewicz J. , Prystawko P. , Halsall M. P. , Sun L.
Published: November 2023

The results of conventional deep-level transient spectroscopy (DLTS) and high-resolution Laplace DLTS measurements of the FeGa(0/−) acceptor level in dilute AlxGa1−xN layers (x ≤ 0.05) grown by MOVPE technique (metal–organic vapor phase epitaxy) on native ammono-GaN substrates are analyzed and discussed. It is shown that the electron emission signal related to the FeGa acceptor level in AlxGa1−xN splits into individual components due to aluminum fluctuations in the second-nearest neighbor (2NN) shell around the FeGa impurity atoms. The calculations of the probability of finding a given number of aluminum atoms in the 2NN shell of the FeGa defect agree well with the experimental concentrations determined from Laplace DLTS peak intensities. This finding shows that in dilute AlxGa1−xN layers grown by MOVPE, aluminum and iron atoms are randomly distributed in the material. Finally, we demonstrate that the energy level of the FeGa acceptor with no Al atoms in the 2NN shell in the AlxGa1−xN samples shifts linearly with the aluminum content and the shifts are 28 and 55 meV relative to that in GaN for the samples with x = 0.025 and 0.05, respectively.
Impact of fire suppressant on seed germination and seedling emergence of native and introduced flora from a Western Australian eucalypt woodland
Authors: Webber Zoe , Harris Richard , Turner Shane , Pedrini Simone
Published: November 2023

Background Phos-Chek WD881A is a short-term retardant used by fire-fighters in Western Australia to suppress and control the movement of fire across the landscape. It is currently applied at a working concentration of 0.1–1%. Aim Our objective was to assess and quantify the impact of the suppressant on seed germination and seedling emergence across eight native and two weed species commonly found in Eucalyptus wandoo woodland. Methods Seeds were exposed to five Phos-Chek concentrations, from 0 to 10% (v/v), in a germination trial in Petri dishes, and three concentrations of 0, 0.1 and 1% (v/v) in a seedling emergence trial. Key findings Increasing concentrations of Phos-Chek both delayed and reduced germination and emergence for all species except Acacia saligna. The sensitivity to Phos-Chek varied among the tested species. Conclusions Phos-Chek had a significant impact on the germination and emergence of native and invasive species, with irreversible damage to seed viability in one taxa (Allocasuarina humilis). Implications It is recommended that applications of Phos-Chek foam remain closer to the minimum recommended concentration (0.1% v/v) to reduce adverse effects on the recruitment of sensitive species, particularly during dry autumns when leaching of this chemical is likely to be limited.
Massive intein content in
Anaeramoeba
reveals aspects of intein mobility in eukaryotes
Authors: Gallot-Lavallée Lucie , Jerlström-Hultqvist Jon , Zegarra-Vidarte Paula , Salas-Leiva Dayana E. , Stairs Courtney W. , Čepička Ivan , Roger Andrew J. , Archibald John M.
Published: November 2023

Inteins are self-splicing protein elements found in viruses and all three domains of life. How the DNA encoding these selfish elements spreads within and between genomes is poorly understood, particularly in eukaryotes where inteins are scarce. Here, we show that the nuclear genomes of three strains of
Anaeramoeba
encode between 45 and 103 inteins, in stark contrast to four found in the most intein-rich eukaryotic genome described previously. The
Anaeramoeba
inteins reside in a wide range of proteins, only some of which correspond to intein-containing proteins in other eukaryotes, prokaryotes, and viruses. Our data also suggest that viruses have contributed to the spread of inteins in
Anaeramoeba
and the colonization of new alleles. The persistence of
Anaeramoeba
inteins might be partly explained by intragenomic movement of intein-encoding regions from gene to gene. Our intein dataset greatly expands the spectrum of intein-containing proteins and provides insights into the evolution of inteins in eukaryotes.
Variability in excess deaths across countries with different vulnerability during 2020–2023
Authors: Ioannidis John P. A. , Zonta Francesco , Levitt Michael
Published: November 2023

Excess deaths provide total impact estimates of major crises, such as the COVID-19 pandemic. We evaluated excess death trajectories across countries with accurate death registration and population age structure data and assessed relationships with vulnerability indicators. Using the Human Mortality Database on 34 countries, excess deaths were calculated for 2020–2023 (to week 29, 2023) using 2017–2019 as reference, with adjustment for 5 age strata. Countries were divided into less and more vulnerable; the latter had per capita nominal GDP < $30,000, Gini > 0.35 for income inequality and/or at least ≥2.5% of their population living in poverty. Excess deaths (as proportion of expected deaths, p%) were inversely correlated with per capita GDP (
r
= −0.60), correlated with proportion living in poverty (
r
= 0.66), and modestly correlated with income inequality (
r
= 0.45). Incidence rate ratio for deaths was 1.062 (95% CI, 1.038–1.087) in more versus less vulnerable countries. Excess deaths started deviating in the two groups after the first wave. Between-country heterogeneity diminished gradually within each group. Less vulnerable countries had mean p% = −0.8% and 0.4% in 0–64 and >65-y-old strata. More vulnerable countries had mean p% = 7.0% and 7.2%, respectively. Lower death rates were seen in children of age 0–14 y during 2020–2023 versus prepandemic years. While the pandemic hit some countries earlier than others, country vulnerability dominated eventually the cumulative impact. Half the analyzed countries witnessed no substantial excess deaths versus prepandemic levels, while the others suffered major death tolls.
Papaya Mealybug in Kenya: Identification, Management, and Future Outlook
Authors: Makale Fernadis , Kansiime Monica K. , Rwomushana Ivan
Published: November 2023

Papaya mealybug,
Paracoccus marginatus
is the most important and damaging insect pest species attacking papaya in Kenya. In addition, it feeds on various crops, fruits, and ornamental plants, most of which are of high economic value in Kenya’s agricultural sector such as chilli pepper, mango, citrus, cassava, avocado, and coffee. The mealybugs cause damage by inserting their stylets into fruits, leaves, and stems, directly feeding on the plant’s vascular system and depleting the sap. Consequently, this leads to chlorosis, plant stunting, leaf deformation, and, if left uncontrolled, leads to eventual plant death. The control of papaya mealybug on Kenyan farms has primarily depended on the application of chemical pesticides and the implementation of cultural practices, but the effectiveness of these methods has been widely reported as inadequate and burdensome. Biological control using a parasitoid
Acerophagus papayae
offers an alternative and sustainable option for the management of papaya mealybug and simultaneously safeguards the native biodiversity threatened by excessive pesticide use. This case study provides insights into the identification, distribution, impacts, and existing management strategies of papaya mealybug in Kenya. Additionally, it emphasizes ongoing and future research endeavours aimed at enhancing papaya mealybug management techniques.

Information

© The Authors 2023
The improved variational nonlinear chirplet mode decomposition via local maximum synchrosqueezing transform and recursive mode extracting scheme for robust estimation of nonlinear chirplet modes and application to fault detection of rotary machine
Authors: You Guang-Hui , Lv Yong , Ma Yubo , Yi Can-Can , Zhang Yi
Published: November 2023

As an advanced time-frequency (TF) decomposition (TFD) method, variational nonlinear chirplet mode decomposition (VNCMD) decomposes the original signal into a series of nonlinear chirplet modes (NCMs), such that the inherent characteristic information contained in the signal can be revealed effectively. However, the decomposition ability of VNCMD is largely affected by the prior instantaneous frequency (IF) and the pre-set parameters. In practical engineering applications, the presence of noise and interference components often complicates the accurate determination of prior IFs and appropriate decomposition parameters. Considering the above issues, in order to precisely extract the NCMs and realize the effective analysis of mechanical vibration signals, this paper mainly focuses on the drawbacks of accurate prior IF and the decomposition parameters of VNCMD, and proposed an improved version via local maximum synchrosqueezing transform and a recursive mode extracting scheme. The performance of the proposed method is evaluated through simulation cases, and the results demonstrate its effectiveness. Finally, the proposed method is successfully applied to bearing data analysis and rub-impact fault detection.
Research on the examination technology of connector pin skewing according to Blob analysis*
Authors: Pan Ruizhi , Li Chao , Hu Bo , Liu Yumei
Published: November 2023

Pin skew detection is an important means to ensure the reliable operation of connectors. To address the issues of low accuracy and limited applicability in existing research, this paper proposes a connector pin skew detection method based on Blob analysis. Firstly, the image is segmented by incorporating the dimensional features of the tested connector to retain the effective information region in the image, reducing the computational workload for subsequent image processing. The image is preprocessed using an improved median filtering algorithm to effectively mitigate the interference of noise on the detection process. Secondly, a locally adaptive approach is employed to dynamically adjust the threshold, and morphological processing is applied to the pin image to enhance the pin speckle features. Subsequently, Blob analysis is utilized to analyze the connector pin speckles, obtaining data on the pin skew. Different evaluation criteria for pin skew data of various connectors are established to achieve quantitative assessment. Finally, experiments are conducted for pin skew detection of single-hole rectangular, double-hole rectangular, and single-hole circular connectors. The experimental results demonstrate that the proposed connector pin skew detection method can effectively detect various types of pin skew in connectors, with a detection accuracy better than 0.05 mm and a repeatability better than 0.03 mm. This method is suitable for automatic detection scenarios of connector pin skew.
Polymerizable sol–gel synthesis of dark-visible light antibacterial magnetically-recoverable AgBr-loaded iron oxide/alumina nanocomposite
Authors: Panda Mousumi , Bose Ananya , Ganesan Ramakrishnan , Ray Dutta Jayati
Published: November 2023

The demand for a facile approach for synthesizing multifunctional nanocomposites is increasingly vital across diverse applications. In this study, a polymerizable sol–gel synthesis has been reported to obtain nanocomposites of magnetic iron oxide deposited over alumina nanopowder. The synthesis is mediated by the deposition of a calculated amount of iron(III) methacrylate, along with ethylene glycol dimethacrylate crosslinker, over alumina nanopowder, followed by thermally-inducing free radical polymerization at 125 °C for 30 min. The powder thus obtained has been subjected to calcination at 400 °C for 150 min and the resultant nanocomposites were characterized using wide-angle x-ray scattering, attenuated total reflectance—Fourier transform infrared spectroscopy, x-ray photoelectron spectroscopy, field-emission scanning electron microscopy, ultraviolet-diffuse reflectance spectroscopy, vibrating sample magnetometer and Brunauer–Emmett–Teller surface area measurements. The nanocomposites containing 15 and 20 wt% of iron oxide have been found to exhibit a saturation magnetization (M
s) value ranging from 12 to 14 emu g−1. To the nanocomposite containing 20 wt% of iron oxide, 5 wt% of AgBr was loaded through thoroughly mixing a surfactant-based precursor, silver-tetraoctyl ammonium bromide (Ag-TOAB), followed by thermolysis. All the nanocomposites have been studied for their antibacterial activity against a representative gram-negative bacterium, Escherichia coli, under dark and visible light conditions. While a 3 mg ml−1 loading of the AgBr-loaded nanocomposite has exhibited complete clearance of the bacterial growth by 90 min in the dark, a similar activity has been observed in 60 min under light. The study has revealed the multifunctionality and high potential of the AgBr-loaded iron oxide/alumina nanocomposite as a promising dual-mode antibacterial and magnetically recoverable photocatalyst material.
Computer simulation of carbonization and graphitization of coal
Authors: Ugwumadu C , Olson III R , Smith N L , Nepal K , Al-Majali Y , Trembly J , Drabold D A
Published: November 2023

This study describes computer simulations of carbonization and graphite formation, including the effects of hydrogen, nitrogen, oxygen, and sulfur. We introduce a novel technique to simulate carbonization, ‘Simulation of Thermal Emission of Atoms and Molecules (STEAM)’, designed to elucidate volatile outgassing and density variations in the intermediate material during carbonization. The investigation analyzes the functional groups that endure through high-temperature carbonization and examines the graphitization processes in carbon-rich materials containing non-carbon impurity elements. The physical, vibrational, and electronic attributes of impure amorphous graphite are analyzed, and the impact of nitrogen on electronic conduction is investigated.
Tunable Ga2O3 solar-blind photosensing performance via thermal reorder engineering and energy-band modulation
Authors: Xi Zhaoying , Yan Sihan , Liu Zeng , Yang Lili , Zhang Maolin , Guo Yufeng , Tang Weihua
Published: November 2023

As an ultra-wide bandgap semiconductor, gallium oxide (Ga2O3) has been extensively applied in solar-blind photodetectors (PDs) owing to the absorbance cut-off wavelength of shorter than 280 nm, and the optimized technologies of detection performance is seriously essential for its further usages. Herein, a feasible thermal reorder engineering method was performed through annealing Ga2O3 films in vacuum, O2 and oxygen plasma atmospheres, realizing to tune solar-blind photosensing performance of Ga2O3 PDs. Thermal treatment, in fact a crystal reorder process, significantly suppressed the noise in Ga2O3-based PDs and enhanced the photo-sensitivity, with the dark current decreasing from 154.63 pA to 269 fA and photo-to-dark current ratio magically raising from 288 to 2.85 × 104. This achievement is dependent of energy-band modulation in Ga2O3 semiconductor, that is certified by first-principles calculation. Additionally, annealing in oxygen atmospheres notably reduces the concentration of oxygen vacancies in the surface of films, thereby improving the performance of the PDs; the oxygen vacancy is extremely concerned in oxide semiconductors in the view of physics of surface defects. In all, this work could display a promising guidance for modulating the performance of PDs based on wide bandgap oxide semiconductor, especially for hot Ga2O3 issue.
Magnetic ac susceptibility of superconducting Ta films for quantum computing
Authors: Yao Juntao , Zhou Chenyu , Lozano Pedro Mercado , Paone Sarah , Liu Mingzhao , Li Qiang
Published: November 2023

Recently, breakthroughs were reported in the long coherence time (>0.5 ms) transmon qubit using tantalum films (Ta). Identifying the loss mechanism in Ta films will help further improve the performance of Ta-based superconducting qubits. Here, we report a study of superconducting properties in two sets of Ta films grown on c-cut and a-cut sapphires respectively using contact transport and noncontact magnetic ac susceptibility measurements. Although the resistive transition appears to be similar in both films, we found strikingly different responses in their complex magnetic susceptibilities

χ

′

+
i
χ

′
′

.

χ

′
′

in the c-cut films exhibits a sharp peak at superconducting transition T
c and becomes featureless below T
c indicating a strongly coupled superconducting state. In contrast,

χ

′
′

in the a-cut films exhibits a broad peak near T
c and a second peak appears below T
c, indicating granular superconductivity behavior. This second peak in

χ

′
′

is associated with the hysteresis loss at weak-link-type grain boundaries, which is believed to be a leading source of decoherence in the a-cut Ta films. The derived magnetic loss tangent in the a-cut films is about one order of magnitude higher than in the c-cut films. This study demonstrates that ac susceptibility is an excellent probe for characterizing bulk superconducting properties of the constituent superconducting materials used in qubits.
A flux pump driven non-soldering closed-loop HTS magnet and its electromagnetic-thermal semi-analytical modelling method
Authors: Zhu Lingfeng , Wang Yinshun , Gao Hanzhi , Hu Chengyang , Liu Wei , Wang Jiawen , Sun Yudong
Published: November 2023

We propose a new flux pump driven non-soldering closed-loop (NSCL) high temperature superconducting (HTS) magnet free of any soldering joints throughout the magnet for persistent current mode (PCM) operation. All the superconducting parts of the magnet are wound directly with HTS closed-loop ring split from an 8 mm REBCO tape using our new cutting scheme free of any soldering requirements. The magnet contains two single-pancake coils connected in series forming a closed circuit through two parallel bridge branches. Two thermal switches set on the two bridge branches control the on–off of the two bridges. A copper coil with iron core installed around one of the bridges is employed as the flux pump to drive the HTS magnet. An electromagnetic-thermal semi-analytical modelling method is proposed to analyse the pumping process by which the transport current in the magnet is calculated. The theoretical limit equation of the saturation current is improved as well. The proposed method can predict the current of the NSCL HTS magnet during the pumping process and provide results that are close to experiments. Experiments verify both the feasibility of the proposed flux pump driven NSCL HTS magnet and the modelling method. The results show that the NSCL HTS magnet works well in the PCM, which provides inspiration to the design of PCM operation of high field HTS magnets. The proposed modelling method also helps guide the design of different forms of HTS magnets and the flux pumps driving them.
A higher-order collocation method based on Haar wavelets for integro-differential equations with two-point integral condition
Authors: Ahsan Muhammad , Lei Weidong , Alwuthaynani Maher , Ahmad Masood , Nisar Muhammad
Published: November 2023

In this article, the higher-order Haar wavelet collocation method (HCMHW) is investigated to solve linear and nonlinear integro-differential equations (IDEs) with two types of conditions: simple initial condition and the point integral condition. We reproduce and compare the numerical results of the conventional Haar wavelet collocation method (CMHW) with those of HCMHW, demonstrating the superior performance of HCMHW across various conditions. Both methods effectively handle different types of given conditions. However, numerical results reveal that HCMHW exhibits a faster convergence rate than CMHW. To address nonlinear IDEs, we employ the quasi-linearization technique. The computational stability of both methods is evaluated through various experiments. Additionally, the article provides examples to illustrate the overall performance and accuracy of HCMHW compared to CMHW for both linear and nonlinear IDEs.
Specular gloss estimation by measuring the colorimetric data produced by a reflection measurement at 8° of incidence
Authors: Safi Mahdi , Ameri Farhad , Ansari Keivan
Published: November 2023

This paper presents an experimental investigation into the estimation of specular gloss from the colorimetric data. The 28 samples were selected from the Natural Color System (NCS) gloss scale, which had different combinations of lightness and gloss levels. The samples’ spectral reflectance and colorimetric data Y and L* were measured by a d:8° geometry reflectance spectrophotometer in both SCE (Specular Component Excluded) and SCI (Specular Component Included) modes. Additionally, the specular gloss of the samples at three common angles 20◦, 60◦, and 85◦ was measured using a gloss meter. The correlation and relationship between DYSCI-SCE and DL*SCI-SCE and the specular gloss values measured for the samples at different angles were evaluated and analyzed with linear and second-polynomial regression functions. The results were validated with a different set of data acquired from 32 random solid-coated samples. The results showed the best fitting was achieved at 60◦ of gloss measurement with a second-polynomial function. As the specular gloss of DY decreased, like in a matt sample, the estimation error of specular gloss increased with a large error of over 10%.
Characterization of a 5 mm thick CZT-Timepix3 pixel detector for energy-dispersive γ-ray and particle tracking
Authors: Smolyanskiy P , Bergmann B , Burian P , Cherlin A , Jelínek J , Maneuski D , Pospíšil S , O’Shea V
Published: November 2023

The present manuscript describes a comprehensive characterization of a novel highly segmented 5 mm CZT sensor attached to Timepix3. First, the sensor’s IV curve was measured and basic sensor characterization was done with laboratory γ-radiation sources. The sensor resistivity was determined to be (0.155± 0.02) GOhm · cm. The sensor showed decent homogeneity, both for the per-pixel count rate and electron mobility-lifetime product μ
e
τ
e. The latter was measured to be

μ

e

τ

e

¯

= 1.3 × 10−3 cm2/V with a standard deviation σ = 0.4 × 10−3 cm2/V describing the dispersion of values for different pixels. The basic sensor characterization is complemented by measurements at grazing angle in a 120 GeV/c at the CERN’s Super Proton Synchrotron. The penetrating nature of these particles together with the pixelation of the sensor allows for a determination of the charge collection efficiency (CCE), as well as charge carrier drift properties (drift times, lateral charge cloud expansion) as a function of the interaction depths in the sensor. While CCE drops by 30%–40% towards the cathode side of the sensor, from the drift time dependency on interaction depth, the electron mobility μ
e was extracted to be (944.8 ± 1.3) cm2/V/s and τ
e = (1.38 ± 0.31) μs. The spectroscopic performance was assessed in photon fields and extracted from energy loss spectra measured at different angles in the pion beam. While at photon energies below 120 keV incomplete charge collection leads to an underestimation of the photon energy when irradiated from the front-side, at higher energies the relative energy resolution was found to be ∼4.5%, while a relative energy resolution of ∼7.5% was found for the particle energy loss spectra. It is shown that the drift time information can be used to reconstruct particle interactions in the sensor in 3D, providing a spatial resolution of σ
xyz = 241 μm within the sensor volume and a particle trajectory measurement precision Δxyz = 100 μm, at a distance of 1 m from the sensor. We demonstrate by measurement with a 22Na source, that the energy resolution combined with the 3D reconstruction allows for detection of γ-ray source location and polarity using Compton scattering within the sensor (Compton camera and scatter polarimeter).
Stable bulk nanobubbles can be regarded as gaseous analogues of microemulsions
Authors: Chen Changsheng , Zhang Hongguang , Zhang Xianren
Published: November 2023

In our previous work [2022 Phys. Chem. Chem. Phys. 24 9685], we used molecular dynamics simulations to show that bulk nanobubbles can be stabilized by forming a compressed amphiphile monolayer at bubble interfaces. This observation closely matches the origin of stability of microemulsions and inspired us to propose here that, in certain cases, stable bulk nanobubbles can be regarded as gaseous analogues of microemulsions: the nanobubble phase and the bubble-containing solution phase coexist with the external gas phase. This three-phase coexistence is then validated by molecular dynamics simulations. The stability mechanism for bulk nanobubbles is thus given: the formation of a compressed amphiphilic monolayer because of microbubble shrinking leads to a vanishing surface tension, and consequently the curvature energy of the monolayer dominates the thermodynamic stability of bulk nanobubbles. With the monolayer model, we further interpret several strange behaviors of bulk nanobubbles: gas supersaturation is not a prerequisite for nanobubble stability because of the vanishing surface tension, and the typical nanobubble size of 100 nm can be explained through the small bending constant of the monolayer. Finally, through analyzing the compressed amphiphile monolayer model we propose that bulk nanobubbles can exist ubiquitously in aqueous solutions.
A review of the etched terminal structure of a 4H-SiC PiN diode
Authors: Zhou Hang , Yan Jingrong , Li Jialin , Ge Huan , Zhu Tao , Zhang Bingke , Chang Shucheng , Sun Junmin , Bai Xue , Wei Xiaoguang , Yang Fei
Published: November 2023

The comparison of domestic and foreign studies has been utilized to extensively employ junction termination extension (JTE) structures for power devices. However, achieving a gradual doping concentration change in the lateral direction is difficult for SiC devices since the diffusion constants of the implanted aluminum ions in SiC are much less than silicon. Many previously reported studies adopted many new structures to solve this problem. Additionally, the JTE structure is strongly sensitive to the ion implantation dose. Thus, GA-JTE, double-zone etched JTE structures, and SM-JTE with modulation spacing were reported to overcome the above shortcomings of the JTE structure and effectively increase the breakdown voltage. They provided a theoretical basis for fabricating terminal structures of 4H-SiC PiN diodes. This paper summarized the effects of different terminal structures on the electrical properties of SiC devices at home and abroad. Presently, the continuous development and breakthrough of terminal technology have significantly improved the breakdown voltage and terminal efficiency of 4H-SiC PiN power diodes.
Development of a simple two-step lithography fabrication process for resonant tunneling diode using air-bridge technology
Authors: Samanta Swagata , Wang Jue , Wasige Edward
Published: November 2023

This article reports on the development of a simple two-step lithography process for double barrier quantum well (DBQW) InGaAs/AlAs resonant tunneling diode (RTD) on a semi-insulating indium phosphide (InP) substrate using an air-bridge technology. This approach minimizes processing steps, and therefore the processing time as well as the required resources. It is particularly suited for material qualification of new epitaxial layer designs. A DC performance comparison between the proposed process and the conventional process shows approximately the same results. We expect that this novel technique will aid in the recent and continuing rapid advances in RTD technology.
Studies on τ decays at Belle II
Authors: Zani L.
Published: November 2023

Tau leptons are powerful tools to probe physics beyond the Standard Model (SM). The Belle II experiment is installed at the SuperKEKB asymmetric energy electron-positron collider and aims at collecting the world's largest sample of tau pair events e+e-→τ+ τ-.
Direct searches for new invisible mediators, charged lepton flavor violation in τ decays, and tests of the SM via precision measurements of τ lepton properties and couplings are reported in the following article. The results presented here are based on the data collected by Belle II during 2019–2021.
CaloClouds: fast geometry-independent highly-granular calorimeter simulation
Authors: Buhmann Erik , Diefenbacher Sascha , Eren Engin , Gaede Frank , Kasicezka Gregor , Korol Anatolii , Korcari William , Krüger Katja , McKeown Peter
Published: November 2023

Simulating showers of particles in highly-granular detectors
is a key frontier in the application of machine learning to particle
physics. Achieving high accuracy and speed with generative machine
learning models would enable them to augment traditional simulations
and alleviate a major computing constraint. This work achieves a
major breakthrough in this task by, for the first time, directly
generating a point cloud of a few thousand space points with energy
depositions in the detector in 3D space without relying on a
fixed-grid structure. This is made possible by two key innovations:
i) Using recent improvements in generative modeling we apply a
diffusion model to generate photon showers as high-cardinality point
clouds. ii) These point clouds of up to 6,000 space points are
largely geometry-independent as they are down-sampled from initial
even higher-resolution point clouds of up to 40,000 so-called
Geant steps. We showcase the performance of this approach
using the specific example of simulating photon showers in the
planned electromagnetic calorimeter of the International Large
Detector (ILD) and achieve overall good modeling of physically
relevant distributions.
A quantum algorithm for track reconstruction in the LHCb vertex detector
Authors: Nicotra D. , Lucio Martinez M. , de Vries J.A. , Merk M. , Driessens K. , Westra R.L. , Dibenedetto D. , Cámpora Pérez D.H.
Published: November 2023

High-energy physics is facing increasingly demanding computational challenges in real-time event reconstruction for the near-future high-luminosity era. Using the LHCb vertex detector as a use case, we explore a new algorithm for particle track reconstruction based on the minimisation of an Ising-like Hamiltonian with a linear algebra approach. The use of a classical matrix inversion technique results in tracking performance similar to the current state-of-the-art but with worse scaling complexity in time. To solve this problem, we also present an implementation as a quantum algorithm, using the Harrow-Hassadim-Lloyd (HHL) algorithm: this approach can potentially provide an exponential speedup as a function of the number of input hits over its classical counterpart, in spite of limitations due to the well-known HHL Hamiltonian simulation and readout problems. The findings presented in this paper shed light on the potential of leveraging quantum computing for real-time particle track reconstruction in high-energy physics.
Archetypes of social-ecological-technological systems for managing ecological infrastructure
Authors: Wicki Sergio , Black Benjamin , Kurmann Manuel , Grêt-Regamey Adrienne
Published: November 2023

The concept of ecological infrastructure (EI) as a lens for landscape management has the potential to address environmental challenges, such as biodiversity loss and ecosystem degradation, by instrumentalizing Nature’s Contributions to People (NCP). NCPs stems from the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) and refers to the various ways in which the natural world provides benefits, values, and services that directly and indirectly contribute to the well-being, livelihoods, and cultural aspects of human societies. This research explores this potential by proposing an archetype analysis of social-ecological-technological systems (SETS) to manage EI. We derived archetypes using machine learning and clustering on a data-driven SETS framework co-produced with experts in EI management. The archetype analysis was conducted by combining K-means with hierarchical clustering on spatial patterns to generate clusters with similar configurations of social, ecological, and technological subsystems. The approach is illustrated for the canton of Geneva, Switzerland, which experiences high urbanization and ecological pressures. The resulting spatially explicit archetypes of SETS facilitate policy recommendations tailored to multifunctional landscapes, which can be used to derive coherent management strategies for EI. In addition, the approach demonstrates that by taking an integrated landscape approach and engaging with diverse stakeholders, it is possible to develop effective landscape-based management recommendations for promoting the sustainable provision of NCPs and biodiversity within the concept of EI.
Evaluating permafrost definitions for global permafrost area estimates in CMIP6 climate models
Authors: Steinert Norman J , Debolskiy Matvey V , Burke Eleanor J , García-Pereira Félix , Lee Hanna
Published: November 2023

Global permafrost regions are undergoing significant changes due to global warming, whose assessments often rely on permafrost extent estimates derived from climate model simulations. These assessments employ a range of definitions for the presence of permafrost, leading to inconsistencies in the calculation of permafrost area. Here, we present permafrost area calculations using 10 different definitions for detecting permafrost presence based on either ground thermodynamics, soil hydrology, or air–ground coupling from an ensemble of 32 Earth system models. We find that variations between permafrost-presence definitions result in substantial differences of up to 18 million km2, where any given model could both over- or underestimate the present-day permafrost area. Ground-thermodynamic-based definitions are, on average, comparable with observations but are subject to a large inter-model spread. The associated uncertainty of permafrost area estimates is reduced in definitions based on ground–air coupling. However, their representation of permafrost area strongly depends on how each model represents the ground–air coupling processes. The definition-based spread in permafrost area can affect estimates of permafrost-related impacts and feedbacks, such as quantifying permafrost carbon changes. For instance, the definition spread in permafrost area estimates can lead to differences in simulated permafrost-area soil carbon changes of up to 28%. We therefore emphasize the importance of consistent and well-justified permafrost-presence definitions for robust projections and accurate assessments of permafrost from climate model outputs.
Time-independent, paraxial and time-dependent Madelung trajectories near zeros
Authors: Berry Michael
Published: November 2023

The Madelung trajectories associated with a wavefunction are the integral curves (streamlines) of its phase gradient, interpretable in terms of the local velocity (momentum) vector field. The pattern of trajectories provides an immediately visualisable representation of the wave. The patterns can be completely different when the same wave equation describes different physical contexts. For the time-independent Schrödinger or Helmholtz equation, trajectories circulate around the phase singularities (zeros) of the wavefunction; and in the paraxially approximate wave, streamlines spiral slowly in or out of the zeros as well as circulating. But if the paraxial wave equation is reinterpreted as the time-dependent Schrödinger equation, its Madelung trajectories do not circulate around the zeros in spacetime: they undulate while avoiding them, except for isolated trajectories that encounter each zero in a cusp singularity. The different local trajectory geometries are illustrated with two examples; a local model explains the spacetime cusps.
Application of singular spectrum analysis to nonstationary time series in flow-induced vibrations of a circular cylinder
Authors: Shen Linwei , Zhu Qianyun
Published: November 2023

In numerical simulations of flow-induced vibrations (FIV) of a circular cylinder, abundant time series data are available, including cylinder displacement and acting forces. Singular spectrum analysis (SSA) is employed to deal with nonstationary multi-component time series produced in two FIV cases with proper interpretation in physics. In the first case, the cylinder displacement time series is decomposed into two oscillatory components using SSA. The instantaneous frequencies of these two components are obtained by Hilbert transform (HT) and found to be in agreement with the wavelet transform of the cylinder displacement. In the second case, three oscillatory components are extracted from the cylinder displacement time series by SSA. The dominant component is characterized by steady oscillations at the vortex shedding frequency, which suggests a relatively steady vortex shedding process behind the rear cylinder. In contrast, the second component, which is closely associated with the alternate boundary layer separations from the front cylinder, features in the increasing amplitude with time. This implies that the unsteady flow field in the gap might be attributed to the nonstationary cylinder oscillations. This work demonstrates that SSA, in conjunction with HT, enables a comprehensive time-frequency analysis of nonstationary time series obtained in FIV.
Tunable multi-metamaterials intergrated with auxiliary magnetorheological resonators
Authors: Jafari Hamid , Sedaghati Ramin
Published: November 2023

In recent years, there has been a surge in interest in utilizing multi-metamaterials for various purposes, such as vibration control, noise reduction, and wave manipulation. To enhance their performance and tunability, auxiliary resonators and magnetorheological elastomers (MREs) can be effectively integrated into these structures. This research aims to formulate the wave propagation analysis of periodic architected structures integrated with MRE-based auxiliary resonators. For this purpose, cantilever MRE beams are embedded into conventional unit cells of square and hexagonal shapes. Integrating MREs into multi-metamaterial structures allows for real-time tuning of the material properties, which enables the multi-metamaterial to adapt dynamically to changing conditions. The wave propagation in the proposed architected structures is analyzed using the finite element method and Bloch’s theorem. The studied low-frequency region is significant, and the addition of MRE resonators leads to the formation of a mixture of locally resonant and Bragg-type stop bands, whereas the basic structures (pure square and hexagonal) do not exhibit any specific band gaps in the considered region. The effect of different volume fractions and applied magnetic fields on the wave-attenuation performance is also analyzed. It is shown that band gaps depend on the material parameters of the resonators as well as the applied magnetic flux stimuli. Moreover, the area of band gaps changes, and their operating frequency increases by increasing the magnetic flux around the periodic structure, allowing for the tuning of wave propagation areas and filtering regions using external magnetic fields. The findings of this study could serve as a foundation for designing tunable elastic/acoustic metamaterials using MRE resonators that can filter waves in predefined frequency ranges.
A novel method for online prediction of the remaining useful life of rolling bearings based on wavelet power spectrogram and Transformer structure
Authors: Guo Xin , Tu Jiesong , Zhan Shengpeng , Zhang Wulin , Ma Lixin , Jia Dan
Published: November 2023

The vibration signal characteristics of rolling bearings are closely related to the performance decay process, predicting the remaining useful life (RUL) of rolling bearings by vibration signals can effectively prevent the occurrence of bearing failures. In this paper, a deep learning-based method for rolling bearing RUL prediction is proposed. The convolutional neural network (CNN), which is more effective in extracting local information, is combined with the Transformer structure, which is specialized in extracting global information, to deeply explore the complex mapping relationship between signal features in wavelet power spectrogram and bearing RUL. Meanwhile, the method of detecting the first prediction time of rolling bearings based on 3

σ

criteria is improved. The proposed method is validated with the XJTU-SY rolling element bearing accelerated life test datasets, as well as compared with other methods to prove its superiority. The results show that the proposed method can effectively extract bearing degradation information and realize the accurate prediction of rolling bearing RUL. The performance-improved rolling bearing RUL prediction model is highly robust and generalizable, which applies to other mechanical parts performance prediction and can be realized for practical applications in industrial fields.
A Helmholtz-type decomposition for the space of symmetric matrices
Authors: Miller Evan , Sawyer Eric
Published: November 2023

In this paper, we introduce a Helmholtz-type decomposition for the space of square integrable, symmetric-matrix-valued functions analogous to the standard Helmholtz decomposition for vector fields. This decomposition provides a better understanding of the strain constraint space, which is important to the Navier–Stokes regularity problem. In particular, we give a full characterization the orthogonal complement of the strain constraint space and investigate the geometry of the eigenvalue distribution of matrices in the strain constraint space.
Effects of phosphorylation on Drp1 activation by its receptors, actin, and cardiolipin
Authors: Liu Ao , Hatch Anna L. , Higgs Henry N.
Published: November 2023

Drp1 is a dynamin family GTPase required for mitochondrial and peroxisomal division. Oligomerization increases Drp1 GTPase activity through interactions between neighboring GTPase domains. In cells, Drp1 is regulated by several factors including Drp1 receptors, actin filaments, cardiolipin, and phosphorylation at two sites: S579 and S600. Commonly, phosphorylation of S579 is considered activating, while S600 phosphorylation is considered inhibiting. However, direct effects of phosphorylation on Drp1 GTPase activity have not been investigated in detail. Here, we compare effects of S579 and S600 phosphorylation on purified Drp1, using phosphomimetic mutants and in vitro phosphorylation. Both phosphomimetic mutants are shifted toward smaller oligomers. Both phosphomimetic mutations maintain basal GTPase activity, but eliminate GTPase stimulation by actin and decrease GTPase stimulation by cardiolipin, Mff, and MiD49. Phosphorylation of S579 by Erk2 produces similar effects. When mixed with wildtype Drp1, both S579D and S600D phosphomimetic mutants reduce the actin-stimulated GTPase activity of Drp1-WT. Conversely, a Drp1 mutant (K38A) lacking GTPase activity stimulates Drp1-WT GTPase activity under both basal and actin-stimulated conditions. These results suggest that the effect of S579 phosphorylation is not to activate Drp1 directly. In addition, our results suggest that nearest neighbor interactions within the Drp1 oligomer affect catalytic activity.
Thymoma Involved by Small Lymphocytic Lymphoma (SLL): A Rare and Challenging Diagnosis
Authors: Khan J , Mesa H , Segura S , Cramer H M
Published: November 2023

Introduction/Objective

Thymoma is a malignant neoplasm arising from the epithelial cells of the thymus. It usually affects patients between the fourth and sixth decades of life. There is a strong association of thymoma with myasthenia gravis and other paraneoplastic syndromes Thymic epithelial tumors are the most common tumors of the anterior mediastinum; however, lymphomas frequently present as mediastinal masses. Concurrent thymoma and lymphoma affecting the thymus is very rare.

Methods/Case Report

A 79-year-old woman with a history of chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL) presented with night sweats and weight loss. Chest CT revealed small pulmonary nodules, a 3.3 x cm anterior mediastinal mass and enlarged hilar lymph nodes. Fine needle aspiration (FNA) of the mass revealed a mixture of lymphocytes and epithelial cells. Flow cytometry showed a monoclonal B-cell population, and double CD4/CD8-positive T-cells consistent with thymocytes. Core biopsy showed scattered neoplastic epithelial cells interspersed among densely packed small lymphocytes. Scattered and small clusters of epithelial cells were highlighted by the CK AE1/3 immunostain. CD3 and PAX5 showed the thymocytes and infiltrating B-cells, respectively. Based on cytomorphologic, flow cytometric, histopathologic, and immunohistochemical findings, the diagnosis of thymoma, type B2 involved by SLL was rendered.

Results (if a Case Study enter NA)

N/A

Conclusion

A multimodality diagnostic work-up integrating cytomorphology, flow cytometry and immunohistochemistry allowed recognizing this unusual association.
Comparison of immunohistochemical (IHC) staining for BerEp4 and MOC31 in Bowen Disease (BD)
Authors: Brudnik R , Toosi P , Barklow T A , Shurbaji M S , Youngberg G A
Published: November 2023

Introduction/Objective

Ber-EP4 and MOC31 are antibodies that target the epithelial cell adhesion molecule (Ep- CAM). In dermatopathology, BerEP4 IHC is classically used to differentiate between basal cell carcinoma (positive) and primary squamous cell carcinoma of the skin (negative). BerEP4 also stains pagetoid tumor cells in Paget Disease (PD), and can be used as part of a panel to assist in differentiating Paget Disease (positive) and Bowen Disease (presumed negative). However, a published abstract reported the unexpected finding that some cases of BD can stain variably positive for BerEP4, a potential pitfall. This finding was subsequently reported in several publications. Recently, MOC-31 has been proposed to be superior to Ber-Ep4 for use in Mohs surgery on basal cell carcinoma. We investigated whether MOC-31 might also show less positivity than Ber-Ep4 in BD, which would be helpful in the context of BD vs. PD.

Methods/Case Report

Biopsy samples from 20 cases of Bowen Disease were examined immunohistochemically with BerEP4 and MOC31.

Results (if a Case Study enter NA)

In Bowen Disease, we found significant BerEP4 positivity (14/20) compared to MOC31 (5/20).

Conclusion

MOC31 shows less frequent staining of BD than Ber-Ep4, which enhances its utility in a BD vs. PD panel.