bluuebunny/crossref_metadata_2025 huggingface dataset:
Cathodoluminescence of CeO2 doped with Gd2O3 in a high voltage electron microscope
Authors: Seo Pooreun , Yasuda Kazuhiro , Costantini Jean-Marc
Published: April 2024

Ceria (CeO2) doped with Gd2O3 (Ce1−xGdxO2−x/2) is considered a surrogate of a burnable poison-doped nuclear fuel. Oxygen vacancies (VO) are induced in Ce1−xGdxO2−x/2 by the substitution of Gd3+ ions into the Ce4+ sites, and the oxygen deficiency is mainly controlled by the Gd2O3 concentration. Oxygen vacancies can also be generated by elastic collisions with high-energy electrons for recoil energies of oxygen atoms above the threshold displacement energy (Ed,O). Oxygen vacancy formation is a key factor to determine the radiation tolerance since it enhances the recombination of point defects. The behavior of point defects in ceramics is known to depend on their charge states, although there is only limited research on this topic. In this study, in situ cathodoluminescence (CL) spectroscopy is applied to studying the charge states of defects induced in the oxygen-deficient cerium dioxides, Ce1−xGdxO2−x/2, by using a high-voltage electron microscope for electron energies from 400 to 1250 keV. The CL emission bands of Ce3+ − VO, Ce3+, and F+ centers are obtained for Ce1−xGdxO2−x/2 as well as pure ceria. An energy shift and quenching of CL emission in Ce1−xGdxO2−x/2 are observed. Those effects are discussed as a consequence of the generation of extrinsic oxygen vacancies induced by Gd2O3 doping (VO,ext) and the influence of the respective electronic configurations of the Ce3+ ions and VO,ext. A schematic picture of energy levels of defects in the bandgap of Ce1−xGdxO2−x/2 is suggested.
Solar-blind ultraviolet emission-detection monolithic integration of AlGaN multiple-quantum-well diodes via concentric ring-circle configuration
Authors: Chen Yuxuan , Jiang Ke , Wang Bingxiang , Liu Kexi , Wang Xianjun , Ben Jianwei , Zhang Shanli , Lu Shunpeng , Chen Yang , Jia Yuping , Liu Mingrui , Sun Xiaojuan , Li Dabing
Published: April 2024

AlGaN multiple-quantum-well diode-based solar-blind ultraviolet emission-detection monolithic integration system shows great application value due to its advantages of multifunctionality, secure communication, and anti-interference ability. To reduce the lateral optical propagation loss and improve the emitting light detection efficiency, we have proposed a concentric ring-circle configuration for the system, where the out-ring light-emitting diode is the emitter at 253 and 267 nm, and the inner-circle detector is the receiver. The out-ring light-emitting diode exhibits about twice the injection current at the same bias and slightly higher light output power at the same current due to better current spreading and sidewall light extraction compared to the conventional square–square configuration. Simultaneously, the concentric inner-circle detector maximizes the collection of the emitted light flux. Under the emission-detection mode for the monolithic integration system, compared to the conventional square–square configuration, the concentric ring-circle design presents an improvement in the ratio of emitter injection current to detector output photocurrent and higher output signal amplitude under the same transmission work mode, demonstrating the improved system energy and coupling efficiency. This design provides a potential approach to achieve low power consumption and high bandwidth in the monolithic integrated optoelectronic chips.
Quantitative microwave-induced thermoacoustic microscopy
Authors: Chen Yi , Chi Zihui , Du Shuang , Fang Qiuchao , Jiang Huabei
Published: April 2024

Visualization and analysis of microstructure of materials or tissue play a pivotal role in industrial manufacturing and pathological diagnosis. Microwave-induced thermoacoustic microscopy (TAM) enables imaging at the microscopic level. TAM, however, is currently qualitative and cannot quantitatively measure intrinsic electromagnetic parameters of materials/tissue, such as conductivity. Here, we propose a quantitative microwave-induced thermoacoustic microscopy (qTAM) approach capable of quantitatively recovering conductivity using a finite element-based iterative inversion strategy coupled with thermoacoustic measurements. We validate the qTAM approach using tissue-mimicking phantoms, and demonstrate its applications to imaging flexible circuits, ex vivo rabbit bone, and rat brain tissues. The results obtained suggest that qTAM may have the potential to become a quantitative tool for microscopic imaging of materials and tissues.
Self-absorption of emission lines in picosecond-laser-produced gold plasmas
Authors: John Lekha Mary , Tarai Akash Kumar , Gundawar Manoj Kumar , K. K. Anoop
Published: April 2024

Ultrashort laser ablation offers several advantages in various applications compared to traditional nanosecond laser ablation techniques. Despite providing a lower damage threshold, cold ablation with high precision, the impact of self-absorption effects in ultrashort laser-produced plasmas (LPPs) significantly affects the assessment of plasma parameters and analytical outcomes in Laser-Induced Breakdown Spectroscopy (LIBS) analysis. This study investigated the impact of laser energy, analyte concentration, and acquisition gate delay on the self-absorption of emission lines from picosecond LPPs (ps-LPPs) of gold targets at atmospheric pressure. We used four gold targets (24 carat gold, 22 carat gold, 18 carat gold, and Hepatizon) with varying concentrations of gold and copper. To analyze the self-absorption effects in ps-LPP, we examined four neutral emission lines of ps-LIBS spectra (Au I: 267.59 and 627.81 nm; Cu I: 327.98 and 510.55 nm). We observed that with an increase in laser pulse energy, there is a corresponding rise in the self-absorption of emission lines under ambient pressure. This increase in analyte species concentration leads to an elevation in the self-absorption of emission lines. Additionally, as the temporal delay of acquisition extends, self-absorption intensifies.
Strain-induced multi-band spin-wave logic gate based on alligator-type magnonic crystal/PZT structure
Authors: Grachev A. A. , Sheshukova S. E. , Sadovnikov A. V.
Published: April 2024

Here, we report the results of strain-controlled spin-wave propagation regimes in a double-period multiferroic structure. It consists of an alligator-type magnonic crystal with a period of 250 μm and a piezoelectric layer, featuring a periodic counter-pin-type electrode system with a period of 125 μm. Employing microwave measurements, we acquired the transmission and dispersion of spin waves under various external electric field configurations applied to the piezoelectric layer. The formation of bandgaps in the magnon spectrum and the variation of the spin-wave transmission when altering the configurations of the external electric field are demonstrated. A finite element method reveals that the combination of the non-uniformity in the initial internal magnetic field of the magnonic crystal, which is caused by the presence of periodic alligator-type regions, together with elastic deformations, heightens the amplitude of the modulation of the internal magnetic field. Micromagnetic modeling has demonstrated that this modulation enhancement results in the variation of the spin-wave transmission at the frequency of the magnonic bandgap center of the magnonic crystal. The proposed design of the reconfigurable magnonic crystal creates a condition for the nucleation of the spin-wave bandgap, with further enhancement of the spin-wave reflection from the periodic grating induced by strain. We demonstrate the potential use of the proposed device as a multi-band NAND/NXOR spin-wave based logic gate.
Nonlinear coupling of tearing modes in reversed field pinch plasmas with stepped pressure profiles
Authors: Fitzpatrick R.
Published: April 2024

A theory of the three-wave coupling of triplets of tearing modes in toroidal pinches [i.e., either reversed field pinches (RFPs) or tokamaks] was proposed by R. Fitzpatrick [Phys. Plasmas 6, 1168 (1999)]. However, this theory only applies to toroidal pinches with negligible equilibrium plasma pressure gradients. Such a limitation is particularly inappropriate to RFPs. This paper generalizes the analysis of R. Fitzpatrick [Phys. Plasmas 6, 1168 (1999)] in order to take the equilibrium pressure gradient into account. However, for the sake of simplicity, a stepped pressure profile, rather than a continuous profile, is employed. In the limit in which the number of steps becomes very large, the results obtained from the generalized theory are presumably equivalent to those that would have been achieved using a continuous pressure profile. The generalized theory is used to investigate the formation of the characteristic toroidally localized pattern of phase-locked m = 1 and m = 0 tearing modes in RFP plasmas that is known as the “slinky” pattern. The incorporation of the equilibrium plasma pressure into the analysis is found to be of crucial importance when determining the properties of the pattern. This is the case because the plasma pressure controls the number of unstable m = 1 and m = 0 tearing modes, and also significantly affects the strength of three-wave coupling, as well as the phase relation between the phase-locked m = 1 and m = 0 modes.
Improving vertical-axis wind turbine performance through innovative combination of deflector and plasma actuator
Authors: Abbasi Sarallah , Daraee Mohammad Amin
Published: April 2024

Vertical-axis wind turbines (VAWTs) are efficient tools for harvesting wind energy, especially in urban areas; however, aerodynamic losses owing to dynamic stall and negative torque reduce their efficiency. Therefore, it is necessary to use flow-control methods for VAWTs. In the present study, a two-dimensional VAWT is numerically modeled and simulated. Subsequently, a novel combined actuator is proposed to improve the performance of VAWT. This novel combined actuator included plasma actuators and deflector plate as active and passive actuators, respectively. First, 16 cases were examined to determine the optimal deflector angle and distance. In the best case, the deflector with an angle of 45° and a radius ratio of 3.3 increased the power coefficient by 13.37% compared to the open rotor. Then, the effect of the combined use of the deflector and plasma actuator was investigated. The results showed that the activation of the plasma actuator from an azimuth angle of 55° to 145° increased the power coefficient by 45.68% in comparison to the open rotor. Considering the energy consumed by actuators, the net energy produced by the VAWT per rotation cycle increased by 26.72% compared to the open rotor.
Magnetic field-induced interfacial pattern formation in thin ferrofluid drops
Authors: Li Qianping , Li Decai , Zhang Shiting , Hu Yang , Wei Yijian , Yu Wenjuan , Wang Zhibin , Qiao Yajing , Liu Lifen , Niu Xiaodong
Published: April 2024

This study investigates the pattern-forming behavior of ferrofluid droplets under the influence of radial magnetic fields. The experimental setup involves depositing initially circular ferrofluid drops surrounded by an immiscible nonmagnetic fluid on a plate with an electromagnet placed below. Through systematic experimentation and theoretical analysis, we explore the effects of two distinct radial magnetic fields on the outer and inner shapes of the droplets. Results reveal the emergence of various intricate interface patterns, including spike-like structures and fingerlike protrusions, as the magnetic Bond number and droplet initial diameter vary. The experimental observations are supported by theoretical predictions derived from mode-coupling differential equations, which provide insight into the underlying dynamics governing pattern formation. This study sheds light on the complex interplay between magnetic and hydrodynamic effects in ferrofluid systems, with implications for diverse applications ranging from microfluidics to biomedical engineering.
Brownian particles in a soft matter potential: A model for directional drug transport and release in polymer network
Authors: Lu Yu , Hu Guo-Hui
Published: April 2024

Improvement of efficiency in drug release is of profound importance in biomedical engineering. The drift and diffusion of Brownian particles in a flexible and porous medium is a typical model for describing the directional drug release system. The tilted periodic potential, usually referred to as the washboard potential (WBP), is a well-known model for describing the motion of Brownian particles in a complex medium. Considering that the drug cargo, such as hydrogel, is flexible and thermally fluctuating, a soft matter potential (SMP), which allows Brownian particles to actively modify the structure of the soft medium, is proposed to describe the polymer networks. The giant acceleration of diffusion (GAD) and the thermodynamic uncertainty relation (TUR) of Brownian particles are investigated in the SMP and WBP, and it is found that the SMP leads to lower GAD and energy cost ⟨q⟩ for a given precision A of drug directional transport. Furthermore, the results indicate that a more deformable drug cargo can achieve a higher directional transport efficiency, that is, a lower Q=⟨q⟩/A. This is potentially applicable to improve the efficiency of controlled directional drug release.
Healing Right Way randomised control trial enhancing rehabilitation services for Aboriginal people with brain injury in Western Australia: translation principles and activities
Authors: Drew Neil , McAllister Meaghan , Coffin Juli , Robinson Melanie , Katzenellenbogen Judith , Armstrong Elizabeth
Published: April 2024

Background This report provides the theory, method and practice of culturally secure translation and knowledge exchange in the Healing Right Way Clinical Trial (2017–2022), outlining activities to date. Healing Right Way was a stepped wedge cluster randomised controlled trial conducted in Western Australia, aimed at enhancing rehabilitation services and quality of life for Aboriginal Australians following acquired brain injury. The trial translation plan was aspirational and action-oriented, with its implementation iterative and ongoing. Translational activities aimed to inform service and research planning for Aboriginal people with brain injury. Situated in the intercultural space, the work guards against undertaking activities that are monocultural, colonial and appropriating in favour of work that is authentically viewed through the dual lens of whiteness and Aboriginal and Torres Strait Islander ways of knowing, being and doing, and is strengths-based. Methods Three translational and knowledge exchange components were identified, relating to the role of Aboriginal Brain Injury Coordinators, cultural training of hospital staff and the research process itself. Knowledge plans were developed for key audiences, with potential translation products to be monitored for ongoing impact. Results Results demonstrate that translational and knowledge exchange were iteratively embedded throughout the trial life cycle. Data sources included community engagement, partnership meetings and interviews. Activities involved presentations to diverse audiences including bureaucrats, community and participants. Conclusions This report provides a snapshot of the first translation knowledge exchange plan and activities constructed in relation to brain injury rehabilitation services for Aboriginal people. Challenges encountered, as well as successes to date, are discussed.
Call Vietnam mouse-deer ‘cheo cheo’ and let empathy save them from extinction: a conservation review and call for name change
Authors: Vuong Quan-Hoang , Nguyen Minh-Hoang
Published: April 2024

The rediscovery of the silver-backed chevrotain (Tragulus versicolor), an endemic species to Vietnam, in 2019 – after almost 30 years of being lost to science – is a remarkable outcome for conservation. Since its rediscovery, there has been significant concern for the conservation of the species due to hunting for wild meat, a practice deeply rooted in Vietnamese culture. Conservation plans face multiple obstacles as the species has not yet been listed as endangered by the International Union for Conservation of Nature due to the lack of data. Given the limited effectiveness of current conservation measures, we propose that local actions, community cooperation, and empathetic values can help conserve the silver-backed chevrotain through integrating modern technologies (e.g. the Internet, crowdfunding platforms, social media, AI, etc.) with citizen and community science. Communicating conservation information to the community, especially children, must stimulate their thinking and imagination about nature, develop their curiosity and desire to protect wildlife, and eventually build conservation and eco-surplus core values in their mindsets. To successfully awaken human values within the community and incorporate them into conservation endeavours, messages referring to ‘mouse-deer’, ‘chevrotain’, or the scientific name T. versicolor are largely ineffective as they fail to engender feelings of familiarity. Therefore, we suggest calling the mouse-deer ‘cheo cheo’, a local name that can create familiarity and closeness, awaken the environmental conscience, and stimulate thinking and imagination. All these factors encourage conservationists, scientists, and the government to support conservation and the community in building a conservation and eco-surplus culture.
A generic approach to infer community-level fitness of microbial genes
Authors: Wang Teng , Weiss Andrea , You Lingchong
Published: April 2024

The gene content in a metagenomic pool defines the function potential of a microbial community. Natural selection, operating on the level of genomes or genes, shapes the evolution of community functions by enriching some genes while depriving the others. Despite the importance of microbiomes in the environment and health, a general metric to evaluate the community-wide fitness of microbial genes remains lacking. In this work, we adapt the classic neutral model of species and use it to predict how the abundances of different genes will be shaped by selection, regardless of at which level the selection acts. We establish a simple metric that quantitatively infers the average survival capability of each gene in a microbiome. We then experimentally validate the predictions using synthetic communities of barcodedEscherichia colistrains undergoing neutral assembly and competition. We further show that this approach can be applied to publicly available metagenomic datasets to gain insights into the environment-function interplay of natural microbiomes.
The Old English gerund in ‑enne or ‑anne
Authors: Versloot Arjen P.
Published: April 2024

This article discusses the historical form of the gerund in Old English, attested both as ‑enne
and ‑anne. The former is commonly considered to be the historical form, while the latter is thought to have
resulted from analogical levelling on the basis of the infinitive that ended in ‑an. The primacy of
‑enne is based on the assumption that i-mutation in unstressed syllables worked to the same
extent as in stressed ones, but it is argued that the working of sound laws can be dependent on stress and the quality of the
mutation factor. In this paper, I propose that the order should be reversed and that ‑anne is the historical
form, while ‑enne probably shows phonological reduction in word-internal position.
Stationen der frühen nordgermanischen Sprachgeschichte
Authors: Schulte Michael
Published: April 2024

The article presents a new periodization of the language of the older runic inscriptions (until 750 AD) by dividing the whole period into four subperiods instead of two (i.e. in contrast to Krause’s dichotomy ofFrühurnordischandSpäturnordisch). The study focuses on the earliest layers of runic inscriptions in older fuþark, namely the pre-classical and classical group prior to 400/450 AD. The new runic finds from Svingerud in Norway reinforce the notion of an archaic, pre-classical runic layer, starting already c. 1/50 AD. In order to distinguish a pre-classical Nordic period, the nominative singular masculine of the weakn-stems is viewed as a decisive criterion, in particular the masculine nouns in-o. In addition, the article presents a valid diagnostic criterion to distinguish between ‘post-classical’ and ‘transitional’ inscriptions, viz. the phoneme-grapheme-correspondences of the starlike rune. The result of this approach is a quadripartite division of the older-fuþark inscriptions that bridges that span between late North-West Germanic and early Old Norse.
Molecular systematics of five Onchocerca species (Nematoda: Filarioidea) including the human parasite, O. volvulus, suggest sympatric speciation
Authors: Morales-Hojas R. , Cheke R.A. , Post R.J.
Published: April 2024

The genus Onchocerca (Nematoda: Filarioidea) consists of parasites of ungulate mammals with the exception of O. volvulus, which is a human parasite. The relationship between O. volvulus, O. ochengi and O. gibsoni remains unresolved. Based on morphology of the microfilariae and infective larvae, vector transmission and geographical distribution, O. ochengi and O. volvulus have been placed as sister species. Nevertheless, the cuticle morphology and chromosomal data (O. volvulus and O. gibsoni have n=4 while O. ochengi is n=5) suggest that O. gibsoni could be more closely related to O. volvulus than O. ochengi. Sequences from the 12S rRNA, 16S rRNA and ND5 mitochondrial genes have been used to reconstruct the phylogeny of five Onchocerca species including O. volvulus. Analyses with maximum likelihood and maximum parsimony showed that O. ochengi is the sister species of O. volvulus, in accordance with the classification based on morphology and geographical location. The separate specific status of the species O. gutturosa and O. lienalis was supported, although their phylogenetic relationship was not well resolved. The analyses indicated that the basal species was O. gibsoni, a South-East Asian and Australasian species, but this result was not statistically significant. The possible involvement of sympatric speciation in the evolution of this group of parasites is discussed.
Investigation of strategies with potential for producing a phosphorylcholine-free version of the filarial nematode immunomodulator, ES-62
Authors: Houston K.M. , Egan C.A. , García P. , Harnett W.
Published: April 2024

Phosphorylcholine (PC) is found attached to N-type glycans of proteins secreted by filarial nematodes, where it appears to act as an immunomodulator. Based on information on the structure and biosynthesis of the PC-glycan of a major secreted protein, ES-62, strategies were designed with potential for preparing PC-free material to better understand the importance of PC in filarial nematode immunomodulation. The strategies involve either enzymatic removal of PC or inhibition of its attachment during ES-62 synthesis. No method tested was found to be 100% effective although ∼70% removal was obtained by culturing worms in Et18OCH3. Reasons for failure to obtain complete absence of PC moieties are discussed in relation to the structure and synthesis of PC-glycans and in addition PC-glycan biosynthesis is briefly commented on as a target for chemotherapy.
Infectivity of Echinostoma friedi miracidia to different snail species under experimental conditions
Authors: Muñoz-Antoli C. , Trelis M. , Toledo R. , Esteban J.G.
Published: April 2024

The infectivity of Echinostoma friedi (Trematoda: Echinostomatidae) miracidia was studied experimentally in a range of laboratory-reared snails that coexist in the same natural locality, namely Radix peregra, Lymnaea fuscus, L. truncatula (Lymnaeidae), Gyraulus chinensis, Helisoma duryi (Planorbidae) and Physella acuta (Physidae), and snails from different geographical origins acting naturally or experimentally as intermediate hosts of Schistosoma spp., namely Planorbarius metidjensis (from Málaga, Spain), Biomphalaria glabrata (Guadeloupe), B. alexandrina (Egypt) (Planorbidae), Bulinus cernicus (Mauritius), B. globosus (Zambia), B. natalensis (South Africa) and B. truncatus (Niger) (Bulinidae). Six species of snails were found to be susceptible, with the rate of infection ranging from 0 to 36.7%. The highest infection was detected in R. peregra. The low host specificity of E. friedi might have an epidemiological significance as a requisite for a recent establishment in a new geographical area.
Changes in parasite transmission stage excretion after pheasant release
Authors: Villanúa D. , Acevedo P. , Toledo R. , Höfle U. , Rodríguez O. , Gortázar C.
Published: April 2024

The production of parasite transmission stages was investigated in the faeces of 77 farm-bred ring-necked pheasants (Phasianus colchicus). Coccidian oocysts (Eimeria sp.), and nematode eggs (Heterakis sp., and Capillaria-like eggs) were recovered before and after release but all birds were treated prior to release. Treatment with fenbendazole significantly reduced the abundance of transmission-stage excretion for all parasites, and reduced the prevalence in the case of Eimeria sp. and Heterakis sp. Nonetheless, a significant increase in the excretion abundance for all parasites and in the prevalence of Eimeria sp. and Heterakis sp. was found after release. Eggs of Ascaridia sp. were found only after releasing, suggesting infection ocurred in the wild. A negative relationship was found between the pheasant body condition and Heterakis excretion abundance and a higher abundance of Capillaria sp. eggs in female birds. No significant relationship was found between parasite excretion abundance and pheasant survival. Despite this, results suggest that an increase in the excretion of parasite transmission stages follows the release of captive pheasants into the wild. This can in part explain restocking failures, but also means that autochtonous free-living birds may become exposed to new and potentially harmful pathogens. To avoid these risks it is proposed that improved prophylactic measures should be taken.
New Generation of Superattenuator for Einstein Telescope: preliminary studies
Authors: Bertocco A , Bruno M , De Rosa R , Di Fiore L , D’Urso D , Frasconi F , Gennai A , Lucchesi L , Refat M , Pilo F , Rozza D , Ruggi P , Sipala V , Tosta e Melo I , Trozzo L
Published: April 2024

Seismic noise and local disturbances are dominant noise sources for ground-based gravitational waves detectors in the low frequency region (0.1–10 Hz) limiting their sensitivity and duty cycle. With the introduction of high-performance seismic isolation systems based on mechanical pendula, the 2nd generation laser interferometric detectors have reached the scientific goal of the first direct observation of GW signals thanks to the extension of the detection bandwidth down to 10 Hz. Now, the 3rd generation instrument era is approaching, and the Einstein telescope giant interferometer is becoming a reality with the possibility to install the detector in an underground site where seismic noise is 100 times smaller than on surface. Moreover, new available technologies as well as the experience acquired in operating advanced detectors are key points to further extend the detection bandwidth down to 2 Hz with the possibility to suspend cryogenic payload and then mitigating thermal noise too. Here, we present a preliminary study devoted to improving seismic attenuation performance of the advanced VIRGO superattenuator in the low frequency region of about five orders of magnitude. Particular care has been carried on in analyzing the possibility to improve the vertical attenuation performance with a multi-stage pendulum chain equipped with magnetic anti-springs that is hung to a double inverted pendulum in nested configuration. The feedback control requirements and possible strategies to be adopted for this last element will be presented.
Multiphoton single and double ionization of neon in the EUV
Authors: Durkan Stephen M , Richardson Vincent , Forembski Andrew , Varvarezos Lazaros , Cubaynes Denis , Düsterer Stefan , Juranić Pavle , Li Wenbin , Richter Mathias , Tiedtke Kai , Meyer Michael , Nikolopoulos L A A , Costello John T
Published: April 2024

New information demonstrating the importance of both sequential and simultaneous (or direct) multiphoton ionization of inner shell electrons from neon is discussed in this paper. Ne was irradiated with intense 93 eV free electron laser (FEL) pulses at FLASH and studied with the aid of photoelectron spectrometry. This resulted in two and three photon, single and double ionization of neon, removing electrons from 2s and 2p subshells of the neutral Ne atom in multiple different pathways. The spectral features of the photoelectrons were identified through comparison with the NIST database and field averaged time-dependent density matrix theory. The calculations show the direct multiphoton ionization processes to be extremely sensitive to the focused FEL intensity.
Relevance of radon progeny measurements for the assessment of inhalation doses in groundwater utilities
Authors: Tyrväinen Jukka T , Naarala Jonne , Turtiainen Tuukka
Published: April 2024

The high radon concentrations measured in the indoor air of groundwater facilities and the prevalence of the problem have been known for several years. Unlike in other workplaces, in groundwater plants, radon is released into the air from the water treatment processes. During the measurements of this study, the average radon concentrations varied from 500 to 8800 Bq m–3. In addition, the indoor air of the treatment plants is filtered and there are no significant internal aerosol sources. However, only a few published studies on groundwater plants have investigated the properties of the radon progeny aerosol, such as the equilibrium factor (F) or the size distribution of the aerosol, which are important for assessing the dose received by workers. Moreover, the International Commission on Radiological Protection has not provided generic aerosol parameter values for dose assessment in groundwater treatment facilities. In this study, radon and radon progeny measurements were carried out at three groundwater plants. The results indicate surprisingly high unattached fractions (fp
= 0.27–0.58), suggesting a low aerosol concentration in indoor air. The corresponding F values were 0.09–0.42, well below those measured in previous studies. Based on a comparison of the effective dose rate calculations, either the determination of the fp
or, with certain limitations, the measurement of radon is recommended. Dose rate calculation based on the potential alpha energy concentration alone proved unreliable.
Attitude solving aided UWB/IMU integrated algorithm with real-time NLOS suppression
Authors: Han Yu , Tan Xinglong
Published: April 2024

In response to the challenges posed by non-line-of-sight (NLOS) errors and inadequate attitude estimation accuracy in ultra-wideband and inertial measurement unit (UWB/IMU) integrated navigation algorithms in the complex environment, a robust UWB/IMU integrated positioning scheme is proposed. On one hand, the utilization of the robust local weighted regression algorithm (RLWR) is employed to mitigate the impact of NLOS errors on UWB data. RLWR incorporates information from nodes with known pseudo-range within local time intervals into the regression model, enhancing the identification of NLOS errors and improving positioning accuracy. On the other hand, the variational Bayesian filter algorithm based on adaptive conjugate gradient descent (ACGD) is proposed to improve the accuracy of IMU attitude calculation. The algorithm leverages an ACGD approach to optimize the attitude output of the accelerometer and magnetometer. The output is then incorporated into the variational Bayesian filtering system alongside the gyroscopic attitude output compensated by integrated positioning. Compared to conventional quaternion calculation and gradient descent linear filtering methods, the approach exhibits superior precision and stability. The experimental findings demonstrate that the amalgamation of the proposed NLSO identification suppression algorithm and the enhanced attitude computation algorithm confers significant advantages in terms of both localization accuracy and attitude estimation precision in complex environments. Moreover, the robust solution presented in the paper ensures the preservation of filter performance in the event of UWB measurement failure.
Frequency dependence of nanorod self-alignment using microfluidic methods
Authors: Shin Hosan , Hong Lia , Park Woosung , Shin Jeeyoung , Park Jae Byung
Published: April 2024

Dielectrophoresis is a potential candidate for aligning nanorods on electrodes, in which the interplay between electric fields and microfluidics is critically associated with its yield. Despite much of previous work on dielectrophoresis, the impact of frequency modulation on dielectrophoresis-driven nanorod self-assembly is insufficiently understood. In this work, we systematically explore the frequency dependence of the self-alignment of silicon nanorod using a microfluidic channel. We vary the frequency from 1kHz to 1000 kHz and analyze the resulting alignments in conjunction with numerical analysis. Our experiment reveals an optimal alignment yield at approximately 100 kHz, followed by a decrease in alignment efficiency. The nanorod self-alignments are influenced by multiple consequences, including the trapping effect, induced electrical double layer, electrohydrodynamic flow, and particle detachment. This study provides insights into the impact of frequency modulation of electric fields on the alignment of silicon nanorods using dielectrophoresis, broadening its use in various future nanotechnology applications.
Small-data global existence of solutions for the Pitaevskii model of superfluidity
Authors: Jang Juhi , Chaitanya Jayanti Pranava , Kukavica Igor
Published: April 2024

We investigate a micro-scale model of superfluidity derived by Pitaevskii (1959 Sov. Phys. JETP
8 282–7) to describe the interacting dynamics between the superfluid and normal fluid phases of Helium-4. The model involves the nonlinear Schrödinger equation (NLS) and the Navier–Stokes equations, coupled to each other via a bidirectional nonlinear relaxation mechanism. Depending on the nature of the nonlinearity in the NLS, we prove global/almost global existence of solutions to this system in

T

2

—strong in wavefunction and velocity, and weak in density.
Anatomy-guided multi-resolution image reconstruction in PET
Authors: Lesonen P , Wettenhovi V-V , Kolehmainen V , Pulkkinen A , Vauhkonen M
Published: April 2024

Objective. In this paper, we propose positron emission tomography image reconstruction using a multi-resolution triangular mesh. The mesh can be adapted based on patient specific anatomical information that can be in the form of a computed tomography or magnetic resonance imaging image in the hybrid imaging systems. The triangular mesh can be adapted to high resolution in localized anatomical regions of interest (ROI) and made coarser in other regions, leading to an imaging model with high resolution in the ROI with clearly reduced number of degrees of freedom compared to a conventional uniformly dense imaging model. Approach. We compare maximum likelihood expectation maximization reconstructions with the multi-resolution model to reconstructions using a uniformly dense mesh, a sparse mesh and regular rectangular pixel mesh. Two simulated cases are used in the comparison, with the first one using the NEMA image quality phantom and the second the XCAT human phantom. Main results. When compared to the results with the uniform imaging models, the locally refined multi-resolution mesh retains the accuracy of the dense mesh reconstruction in the ROI while being faster to compute than the reconstructions with the uniformly dense mesh. The locally dense multi-resolution model leads also to more accurate reconstruction than the pixel-based mesh or the sparse triangular mesh. Significance. The findings suggest that triangular multi-resolution mesh, which can be made patient and application specific, is a potential alternative for pixel-based reconstruction.
Suppressing label noise in medical image classification using mixup attention and self-supervised learning
Authors: Gao Mengdi , Jiang Hongyang , Hu Yan , Ren Qiushi , Xie Zhaoheng , Liu Jiang
Published: April 2024

Deep neural networks (DNNs) have been widely applied in medical image classification and achieve remarkable classification performance. These achievements heavily depend on large-scale accurately annotated training data. However, label noise is inevitably introduced in the medical image annotation, as the labeling process heavily relies on the expertise and experience of annotators. Meanwhile, DNNs suffer from overfitting noisy labels, degrading the performance of models. Therefore, in this work, we innovatively devise a noise-robust training approach to mitigate the adverse effects of noisy labels in medical image classification. Specifically, we incorporate contrastive learning and intra-group mixup attention strategies into vanilla supervised learning. The contrastive learning for feature extractor helps to enhance visual representation of DNNs. The intra-group mixup attention module constructs groups and assigns self-attention weights for group-wise samples, and subsequently interpolates massive noisy-suppressed samples through weighted mixup operation. We conduct comparative experiments on both synthetic and real-world noisy medical datasets under various noise levels. Rigorous experiments validate that our noise-robust method with contrastive learning and mixup attention can effectively handle with label noise, and is superior to state-of-the-art methods. An ablation study also shows that both components contribute to boost model performance. The proposed method demonstrates its capability of curb label noise and has certain potential toward real-world clinic applications.
Ar(1s5) density in a co-axial argon plasma jet with N2–O2 shielding
Authors: Gonçalves Duarte , Bauville Gérard , Jeanney Pascal , Lino da Silva Mário , Lemos Alves Luís , Pasquiers Stéphane , Santos Sousa João
Published: April 2024

Atmospheric-pressure microplasma jets (µAPPJs) are versatile sources of reactive species with diverse applications. However, understanding the plasma chemistry in these jets is challenging due to plasma-flow interactions in heterogeneous gas mixtures. Spatial metastable density profiles help to understand these physical and chemical mechanisms. This work focuses on controlling the shielding gas around a µAPPJ. We use a dielectric barrier discharge co-axial reactor where a co-flow shields the pure argon jet with different N2–O2 gas mixtures. A voltage pulse (4 kV, 1 µs, 20 kHz) generates a first discharge at the pulse’s rising edge and a second discharge at the falling edge. Tunable diode laser absorption spectroscopy measures the local Ar(1s5) density. A pure N2 (100%N2–0%O2) co-flow leads to less reproducible and lower peak Ar(1s5) density (

5.8
×

10

13

cm

−
3

). Increasing the O2 admixture in the co-flow yields narrower Ar(1s5) absorbance profiles and increases the Ar(1s5) density (

6.9
×

10

13

to

9.1
×

10

13

cm

−
3

). The position of the peak density is closer to the reactor for higher O2 fractions. Absence of N2 results in comparable Ar(1s5) densities between the first and second discharges (maxima of

9.1
×

10

13

and

9.3
×

10

13

cm

−
3

, respectively). Local Ar(1s5) density profiles from pure N2 to pure O2 shielding provide insights into physical and chemical processes. The spatially-resolved data may contribute to optimising argon µAPPJ reactors across the various applications and to validate numerical models.
Behavior of quantum coherence in quantum phase transitions of two-dimensional XY and ising models
Authors: Taghadomi N , Mani A , Bakouei A
Published: April 2024

We investigate the quantum coherence behavior of the ground states of 2D Heisenberg XY model and 2D Ising model with a transverse field on square lattices using the Quantum Renormalization Group (QRG) method. Our analysis focused on the ground state density matrix and its marginal states, revealing non-analytic behavior of quantum coherence (especially two-site coherence) near the critical point. This behavior allowed us to detect quantum phase transitions (QPT) in these models. By examining the scaling behavior of the maximum derivative of quantum coherence with system size, we determined the critical exponent of coherence for both models and the length exponent of the Ising model. Additionally, we investigated the time evolution of coherence in both models. Our results closely align with those obtained from entanglement analysis, that is while quantum coherence requires fewer computational calculations compared to discord and entanglement approaches.
Construction and volumetric benchmarking of quantum computing noise models
Authors: Weber Tom , Borras Kerstin , Jansen Karl , Krücker Dirk , Riebisch Matthias
Published: April 2024

The main challenge of quantum computing on its way to scalability is the erroneous behaviour of current devices. Understanding and predicting their impact on computations is essential to counteract these errors with methods such as quantum error mitigation. Thus, it is necessary to construct and evaluate accurate noise models. However, the evaluation of noise models does not yet follow a systematic approach, making it nearly impossible to estimate the accuracy of a model for a given application. Therefore, we developed and present a systematic approach to benchmarking noise models for quantum computing applications. It compares the results of hardware experiments to predictions of noise models for a representative set of quantum circuits. We also construct a noise model containing five types of quantum noise and optimize its parameters using a series of training circuits. We compare its accuracy to other noise models by volumetric benchmarks involving typical variational quantum circuits. The model can easily be expanded by adding new quantum channels.
Core electron temperature turbulence and transport during sawtooth oscillations in the DIII-D tokamak
Authors: Wang G. , Rhodes T.L. , Pratt Q.T. , Peebles W.A. , Crocker N.A. , Hong R. , Austin M.E. , Van Zeeland M.A. , Smith S.P.
Published: April 2024

Sawteeth are one of the concerning instabilities in ITER and future burning plasma experiments. Sawtooth dynamics and its interaction with broadband plasma turbulence has been a challenge for predictive simulations of core transport in future fusion devices. This study provides new observations of core turbulence behavior during sawtooth oscillations in DIII-D hydrogen L-mode neutral beam injection heated plasmas in an inner wall limited configuration. A strong correlation of electron temperature and density turbulence levels with the sawtooth oscillation phase has been observed at locations inside the T
e inversion radius and/or safety factor q = 1 magnetic surface. The T
e turbulence amplitude in the core during the sawtooth ramp exhibits a critical T
e gradient behavior inside but not near the T
e inversion radius/q = 1 magnetic surface. The most unstable mode calculated from the trapped gyro-landau fluid turbulence simulations reveal a change from low-k ion-type to low-k electron-type modes from pre- to post- sawtooth crash time periods.
Physical Properties of Biochar Produced from Pyrolysis of Arabica Coffee Pulp: The Effect of Pre-Washing Process
Authors: Setiawan A , Muhammad F , Nurjannah S , Riskina S , Muhammad  , Hakim L
Published: April 2024

Coffee pulp is a potential source of biomass which abundantly available in coffee exporter countries such as Brazil, Colombia, Indonesia etc. It is necessary to develop technologies to convert coffee pulp into value-added products. This study aims to investigate the slow pyrolysis process of arabica coffee pulp in a pilot scale reactor and evaluate the properties of resulting biochar. Prior to pyrolysis experiment, some of coffee pulp were soaked in tap water for 20 h with a ratio of water to coffee pulps of 1:5. As comparison, another set of pyrolysis experiment was carried out without soaking and washing of feedstock. The pyrolysis process was carried out in a batch reactor at temperatures within the range of 400 to 420°C. During the run, the reaction temperature versus time was recorded and products yield were quantified. Characterization of biochar product was performed under proximate, bomb calorimeter and density analyses. The yield of biochar and pyrolytic oil, respectively were 33% and 36%. Biochar characterization results suggested a significant decrease in the ash content when washing pretreatment was applied. Increases in the calorific value and bulk density were also observed from pre-washed coffee pulp sample.
Potential Torrefaction of Tropical Forest Fruits Waste
Authors: Prayitno H , Amrul  , Lestari R , Kurniawansah R
Published: April 2024

Biomass torrefaction can improve the quality of raw biomass as fuel. Tropical forest fruit waste that is not managed properly will become waste that contributes to increasing greenhouse gas emissions. Conversion of tropical forest fruit waste into biomass fuel by torrefaction can be used as coal co-firing. In this research, torrefaction was carried out on the biomass from the cocoa pod shell, coffee husks, and mangosteen pod shell. The samples used in this study came from tropical forest fruits in Lampung Province. Samples were chopped and dried using the hot sun. The samples were then torrefied in a tubular reactor at temperatures of 250, 275, and 300°C and their calorific values were tested. Torrefaction at 275°C has increased the calorific value of tropical forest fruit waste to exceed the calorific value of sub-bituminous A. Torrefaction of tropical forest fruit waste has the potential to be used as fuel for co-firing coal in power plants. Thus, it can indirectly reduce the rate of CO2 emissions from power generation and waste accumulation. In addition, it also has the potential to become a competitive sustainable export commodity.
The Effect of Use of Adhesive to Calorific Value Cymbopogon Nardus Waste Briquettes
Authors: Hendri N , Sari D Y , Wagino  , Sakti D , Ramadhan A
Published: April 2024

The consumption of fuel in the community is getting higher day by day so it has an impact on its shortage and scarcity. The search for potential energy sources as alternative fuels is increasingly being developed. In this livelihood, renewable alternative energy is needed. The Cymbopogon nardus plant which has taken its oil through a refining process and eventually becomes waste is still possible for use as briquettes. This study will examine Cymbopogon nardus waste briquettes’ calorific value with the use of tapioca and damar adhesives so that their presence can be applied to the community. The method of making briquettes made from Cymbopogon nardus waste with a concentration ratio of 90%, 80%, 70%, and 60% of the use of adhesives. The combination of raw materials and adhesives is then given a compaction compression process. The result of research, Cymbopogon nardus waste briquettes the calorific value with tapioca adhesive is 9972.55 kJ/kg at a ratio of 90%, while the calorific value with damar adhesive is 11318.84 kJ/kg. The use of adhesives in the process of making Cymbopogon nardus waste briquettes shows the effect of the calorific value. Of course, the hope in the development of briquettes that utilize Cymbopogon nardus waste makes a real opportunity to be applied to the community in efforts to develop renewable energy.