bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantitation of carotenoids and fatty acids from Atlantic salmon using a portable Raman device
Authors: Landry Jeremy D. , Torley Peter J. , Blanch Ewan W.
Published: August 2022

Raman spectra collected using subsurface measurement on a portable device can be used to quantify carotenoid and lipid levels in Atlantic salmon.
Simultaneous photocatalytic H2generation and organic synthesis over crystalline–amorphous Pd nanocube decorated Cs3Bi2Br9
Authors: Wang Chunhua , Weng Bo , Liao Yuhe , Liu Biao , Keshavarz Masoumeh , Ding Yang , Huang Haowei , Verhaeghe Davy , Steele Julian A. , Feng Wenhui , Su Bao-Lian , Hofkens Johan , Roeffaers Maarten B. J.
Published: August 2022

Development of metal halide perovskite photocatalysts that can efficiently perform selective organic oxidations in combination with H2evolution at mild conditions.
Hydrogen phosphates play a critical structural role in amorphous calcium phosphates
Authors: Li Shu-Li , Wang Li-Han , Lin Yi-Tan , Huang Shing-Jong , Chan Jerry Chun Chung
Published: August 2022

Amorphous calcium phosphate (ACP) prepared by different dehydration methods have different speciation of phosphate ions.
H atom scattering from W(110): A benchmark for molecular dynamics with electronic friction.
Authors: Martin-Barrios Raidel , Hertl Nils , Galparsoro Oihana , Kandratsenka Alexander , Wodtke Alec M. , Larrégaray Pascal
Published: August 2022

Molecular dynamics with electronic friction (MDEF) at the level of the local density friction approximation (LDFA) has been applied to describe electronically non-adiabatic energy transfer accompanying H atom collisions with many solid metal surfaces.
Single-site, Ni-modified Wells–Dawson-type polyoxometalate for propylene dimerization
Authors: Magazova Galiya , Cho Yoonrae , Muhlenkamp Jessica A. , Hicks Jason C.
Published: August 2022

Propylene dimerization to linear products on isolated Ni2+sites of modified Wells–Dawson-type polyoxometalates.
Designing fluorine-free electrolytes for stable sodium metal anodes and high-power seawater batteries via SEI reconstruction
Authors: Kim Jinuk , Kim Jioh , Jeong Jooyoung , Park Jiwon , Park Cheol-Young , Park Sewon , Lim Shin Gwon , Lee Kyu Tae , Choi Nam-Soon , Byon Hye Ryung , Jo Changshin , Lee Jinwoo
Published: August 2022

F-free, cost-effective 1 M NaBH4/glyme electrolytes induce SEI reconstruction, which converts the native oxide layer on sodium metal to a NaH-based SEI layer. With 1 M NaBH4/DEGDME, we achieved long-term cycling, high-power seawater batteries.
Symmetry-driven diastereoselective functionalization of simple trianglamine
Authors: Skowronek Paweł , Prusinowska Natalia , Bardziński Mateusz , Janiak Agnieszka
Published: August 2022

A trianglamine macrocycle can be easily derivatized by aliphatic aldehydes. Of the two possible diastereomeric aminal products, only one is obtained in good yield.
Enamine-mediated Mannich reaction of cyclicN,O-acetals and amido acetals: the multigram synthesis of pyrrolidine alkaloid precursors
Authors: Turmanov Rakhymzhan A. , Smolobochkin Andrey V. , Gazizov Almir S. , Rizbayeva Tanzilya S. , Zapylkin Danil D. , Voronina Julia K. , Voloshina Alexandra D. , Syakaev Victor V. , Kurenkov Alexey V. , Burilov Alexander R. , Pudovik Michail A.
Published: August 2022

Anl-proline/Brønsted acid/base organocatalytic system enables gram-scale synthesis of 2-(acylmethylene)pyrrolidines through enamine activation.
Bicyclobutanes: from curiosities to versatile reagents and covalent warheads
Authors: Kelly Christopher B. , Milligan John A. , Tilley Leon J. , Sodano Taylor M.
Published: August 2022

A flurry of reports for preparing, functionalizing, and using bicyclo[1.1.0]butanes (BCBs) have positioned them to be powerful synthons with numerous applications. This review discusses the recent developments regarding this strained carbocycle.
Flexible and adhesive liquid-free ionic conductive elastomers toward human–machine interaction
Authors: Xu Zhenyu , Li Rui , Li Huijing , Gao Guorong , Chen Tao
Published: August 2022

The stretchable and adhesive liquid-free ionic conductive elastomers were developed and assembled into triboelectric nanogenerators for use as human–machine interactive keyboards.
Three‐phase service level agreements and trust management model for monitoring and managing the services by trusted cloud broker
Authors: C Muralidharan , Y Mohamed Sirajudeen , S Shitharth , Alhebaishi Nawaf , Mosli Rayan H. , Alhelou Hassan Haes
Published: August 2022

Cloud computing is an environment where everything is provided as a service based on demand. It follows pay as per the used model in which the service consumer needs to pay for what they have consumed. Due to the increased dependence on digitalization, the number of consumers and providers tends to grow tremendously. The consumer who needs the service from the provider is not sure about the specified service outcome, and it is too hard for them to monitor and manage the service. Hence, a trusted third party called a trusted cloud broker (TCB) is introduced for managing the services. The service level agreements (SLA) management and reputation estimation framework is proposed, which includes three phases such as (i) SLA establishment between the three parties, (ii) violation detection by comparing the observed value of the TCB and (iii) the reputation and penalty estimation of the service. The novel TCB is created to monitor the deployed services, ensuring the achievement of SLA. The TCB observes the values and estimates the reputation value for each service. It is compared with the provider log‐based reputation value and found that the proposed model provides a more precise reputation value for the service providers.
Increasing the raw contrast of VLT/SPHERE with the dark hole technique
Authors: Potier A. , Mazoyer J. , Wahhaj Z. , Baudoz P. , Chauvin G. , Galicher R. , Ruane G.
Published: August 2022

Context. Direct imaging of exoplanets takes advantage of state-of-the-art adaptive optics (AO) systems, coronagraphy, and postprocessing techniques. Coronagraphs attenuate starlight to mitigate the unfavorable flux ratio between an exoplanet and its host star. AO systems provide diffraction-limited images of point sources and minimize optical aberrations that would cause starlight to leak through coronagraphs. Post-processing techniques then estimate and remove residual stellar speckles due to hardware limitations, such as noncommon path aberrations (NCPAs) and diffraction from telescope obscurations, and identify potential companions.

Aims. We aim to demonstrate an efficient method to minimize the speckle intensity due to NCPAs and the underlying stellar diffraction pattern during an observing night on the Spectro-Polarimetric High-contrast Expolanet REsearch (SPHERE) instrument at the Very Large Telescope (VLT) instrument without any hardware modifications.

Methods. We implement an iterative dark-hole (DH) algorithm to remove stellar speckles on-sky before a science observation. It uses a pair-wise probing estimator and a controller based on electric field conjugation, originally developed for space-based application. This work presents the first such on-sky minimization of speckles with a DH technique on SPHERE.

Results. We show the standard deviation of the normalized intensity in the raw images is reduced by a factor of up to five in the corrected region with respect to the current calibration strategy under median conditions for VLT. This level of contrast performance obtained with only 1 min of exposure time reaches median performances on SPHERE that use post-processing methods requiring ~1h-long sequences of observations. The resulting raw contrast improvement provides access to potentially fainter and lower-mass exoplanets closer to their host stars. We also present an alternative a posteriori calibration method that takes advantage of the starlight coherence and improves the post-processed contrast levels rms by a factor of about three with respect to the raw images.

Conclusions. This on-sky demonstration represents a decisive milestone for the future design, development, and observing strategy of the next generation of ground-based exoplanet imagers for 10-m to 40-m telescopes.
Suppliers’ online channel structure strategies under product innovation effect and spillover effect
Authors: Liu Jie , Wu Xiaoli , Yang Bai , Yang Shanxue
Published: August 2022

In this paper, we investigate how spillovers from online sales to offline sales and product innovation jointly affect suppliers’ optimal online channel structure strategies. By comparing equilibrium outcomes of the game between a supplier, an offline retailer and an online retailer in different scenarios, including the scenario without product innovation, the scenario with exogenous product innovation and the scenario with endogenous product innovation, we obtain some novel management implications. There exists a threshold curve such that when the supplier’s marginal operating cost is below the threshold curve, the supplier is better off establishing a direct online channel, otherwise, the supplier should introduce an independent online channel. Nonetheless, the threshold curve is not a monotonic function of the spillover coefficient, but a function that decreases first and then increases with the the spillover coefficient. Exogenous product innovation does not change the supplier’s optimal online channel structure strategy qualitatively, it leads to some quantitative changes, shifting the threshold curve upward. However, endogenous product innovation changes the position and shape of the threshold curve significantly and gives the supplier the flexibility to establish the direct online channel. This paper reveals an underlying trade-off between online channel operational efficiency and channel coordination, providing suppliers managerial suggestions on online channel structure strategies.
“Let us talk”: incorporating the Coordinated Management of Meaning’s communication perspective as part of public diplomacy efforts between government, the private sector, and the foreign public
Authors: Limani Blerim , Limani Emira
Published: August 2022

The present study aims to explore the current model of communication applied between critical stakeholders such as the government and private sector engaged in public diplomacy efforts for promoting or improving the country’s reputation to the foreign public. A literature review shows that the current communication model applied by the mentioned stakeholders is based on the transmission model, which, to be successful, relies on an ideal version of the communication process where the message gets clearly through the channel while assuming the receiver’s understanding is as close as it gets to the sender’s intention. This process, however, omits communication complexities that derive from such a process where new social realities are being co-created by stakeholders. Consequently, the authors argue that there is a need to introduce a communication model that enables stakeholders to achieve a more sustainable coordination-focused outcome that would benefit both government and the private sector. The methodology is based on the Coordinated Management of Meaning (CMM) theoretical framework that helps identify the current transmission-based public diplomacy communication model while recommending a new model based on a communication perspective. Finally, a communication model is created to describe the needed shift from the current traditional public diplomacy communication process (based on the transmission model) to the one suggested by CMM. Further research is needed where the actual CMM-based communication model will be applied by stakeholders and adequately monitored and evaluated.
Elderly chronic diseases and catastrophic health expenditure: an important cause of Borderline Poor Families’ return to poverty in rural China
Authors: Xu Xiaocang , Yang Haoran
Published: August 2022

The huge health expenditure for chronic diseases in the elderly is one of the uncertain factors that may cause the Borderline poor families to return to poverty after China fully lifts itself out of poverty in 2020, especially in rural low-income areas. Based on the latest data released by China Health and Retirement Longitudinal Study, this paper used the two-part model to analyze the impact of elderly chronic diseases on health expenditure and catastrophic health expenditure of Borderline poor families in rural China. Some interesting results were found. For example, elderly chronic diseases such as stroke and hepatic disease have a large impact on the catastrophic health expenditures of families on the edge of poverty in rural China. Therefore, the government should drive middle-aged and elderly people to actively participate in physical exercise and prevent the high incidence of chronic diseases in the elderly. Furthermore, the government should improve the medical insurance system to provide solid support for low-income families and other vulnerable groups to avoid returning to poverty.
Growth rate of a stochastic growth process driven by an exponential Ornstein–Uhlenbeck process
Authors: Pirjol Dan
Published: August 2022

We study the stochastic growth process in discrete time xi+1 = (1 + μi)xi with the growth rate μi=ρeZi−12Var(Zi) proportional to the exponential of an Ornstein–Uhlenbeck (O–U) process dZt = −γZtdt + σdWt sampled on a grid of uniformly spaced times with time step τ. Using large deviation theory, we compute the asymptotic growth rate (Lyapunov exponent) λ=limn→∞1nlogE[xn]. We show that this limit exists, under appropriate scaling of the O–U parameters, and is expressed as the solution of a variational problem. The asymptotic growth rate is equal to the thermodynamical pressure of a one-dimensional lattice gas with attractive exponential potentials. For Zt, a stationary O–U process of the lattice gas coincides with a model considered previously by Kac and Helfand. We derive upper and lower bounds on λ. In the large mean-reversion limit γnτ ≫ 1, the two bounds converge and the growth rate is given by a lattice version of the van der Waals equation of state. The predictions are tested against numerical simulations of the stochastic growth model.
Amplitude response, Melnikov’s criteria, and chaos occurrence in a Duffing’s system subjected to an external periodic excitation with a variable shape
Authors: Ndjomatchoua Frank T. , Djomo Thierry L. M. , Kemwoue Florent F. , Gninzanlong Carlos L. , Kepnang Maxime P. , Siewe Martin S. , Tchawoua Clément , Pedro Sansao A. , Kofane Timoleon C.
Published: August 2022

The present study considers the nonlinear dynamics of a Duffing oscillator under a symmetric potential subjected to a pulse-type excitation with a deformable shape. Our attention is focused on the effects of the external excitation shape parameter r and its period. The frequency response of the system is derived by using a semi-analytical approach. Interestingly, the frequency–response curve displays a large number of resonance peaks and anti-resonance peaks as well. Surprisingly, a resonance phenomenon termed here as shape-induced-resonance is noticed as it occurs solely due to the change in the shape parameter of the external periodic force. The system exhibits amplitude jumps and hysteresis depending on r. The critical driving magnitude for the chaos occurrence is investigated through Melnikov’s method. Numerical analysis based on bifurcation diagrams and Lyapunov exponent is used to show how chaos occurs in the system. It is shown that the threshold amplitude of the excitation to observe chaotic dynamics decreases/increases for small/large values of r. In general, the theoretical estimates match with numerical simulations and electronic simulations as well.
Comparative study on atomically heterogeneous surface with conical arrays of field emitters generated using plasma based low-energy ion beams
Authors: Majumdar Jayashree , Bhattacharjee Sudeep
Published: August 2022

A comparative study of the field emission properties of conical arrays of atomically heterogeneous, self-organized, micro–submicro–nanodimensional structures, irradiated at normal incidence by high flux of 2 keV argon (flux=6.47×1015cm−2s−1) and krypton ions (flux=4.81×1015cm−2s−1) on copper substrates, without employing any external seeding, is presented. The variation in surface structural growths with ion beam fluence is investigated using scanning electron, atomic force, and transmission electron microscopy. The exposed surfaces are atomically heterogeneous due to the presence of embedded argon and krypton ions in the interstitial layers (≈nm) as observed from the x-ray photoelectron spectroscopy analysis. Kelvin probe force microscopy is employed to analyze the variation in local work function caused by surface deformities and implantation of inert gaseous ions. The conical arrays are naturally selected field emitter sources, and their field enhancement factor is calculated from the Fowler–Nordheim equations. The argon ion treated substrate at a fluence of 4.85×1018cm−2 gives rise to uniformly distributed structures and has a low turn-on voltage of 2.76 kV with an electron emission current of 0.58 nA. Among the krypton ion irradiated substrates, the sample irradiated at the highest fluence of 5.12×1018cm−2 produces self-organized conical arrays having uniform dimension, orientation, distribution, and even a higher electron emission current of 0.81 nA with a lower turn-on voltage of 2.12 kV. Thus, it may be concluded that krypton ion irradiation provides better generation of naturally selected arrays of field emitters.
Optimizing protection resource allocation for traffic-driven epidemic spreading
Authors: Chen Jie , Cao Jinde , Li Ming , Hu Maobin
Published: August 2022

Optimizing the allocation of protection resources to control the spreading process in networks is a central problem in public health and network security. In this paper, we propose a comprehensive adjustable resource allocation mechanism in which the over allocation of resources can be also numerically reflected and study the effects of this mechanism on traffic-driven epidemic spreading. We observe that an inappropriate resource allocation scheme can induce epidemic spreading, while an optimized heterogeneous resource allocation scheme can significantly suppress the outbreak of the epidemic. The phenomenon can be explained by the role of nodes induced by the heterogeneous network structure and traffic flow distribution. Theoretical analysis also gives an exact solution to the epidemic threshold and reveals the optimal allocation scheme. Compared to the uniform allocation scheme, the increase in traffic flow will aggravate the decline of the epidemic threshold for the heterogeneous resource allocation scheme. This indicates that the uneven resource allocation makes the network performance of suppressing epidemic degrade with the traffic load level. Finally, it is demonstrated that real-world network topology also confirms the results.
Comprehensive characterization of irradiation induced defects in ceria: Impact of point defects on vibrational and optical properties
Authors: Chauhan Vinay S. , Ferrigno Joshua , Adnan Saqeeb , Pakarinen Janne , He Lingfeng , Hurley David H. , Khafizov Marat
Published: August 2022

Validation of multiscale microstructure evolution models can be improved when standard microstructure characterization tools are coupled with methods sensitive to individual point defects. We demonstrate how electronic and vibrational properties of defects revealed by optical absorption and Raman spectroscopies can be used to compliment transmission electron microscopy (TEM) and x-ray diffraction (XRD) in the characterization of microstructure evolution in ceria under non-equilibrium conditions. Experimental manifestation of non-equilibrium conditions was realized by exposing cerium dioxide (CeO2) to energetic protons at elevated temperature. Two sintered polycrystalline CeO2 samples were bombarded with protons accelerated to a few MeVs. These irradiation conditions produced a microstructure with resolvable extended defects and a significant concentration of point defects. A rate theory (RT) model was parametrized using the results of TEM, XRD, and thermal conductivity measurements to infer point defect concentrations. An abundance of cerium sublattice defects suggested by the RT model is supported by Raman spectroscopy measurements, which show peak shift and broadening of the intrinsic T2g peak and emergence of new defect peaks. Additionally, spectroscopic ellipsometry measurements performed in lieu of optical absorption reveals the presence of Ce3+ ions associated with oxygen vacancies. This work lays the foundation for a coupled approach that considers a multimodal characterization of microstructures to guide and validate complex defect evolution models.
A novel method for measuring latent heat of low-temperature PCM phase transition by oxygen bomb calorimeter
Authors: Meng Fankang , Jiang Zhixin , Yan Minghui
Published: August 2022

The method for the determination on the latent heat of phase change by oxygen bomb calorimetry of low-temperature phase change materials (PCMs) was feasible and validated. Experiments on the solidification of the variable boundary temperature of OP24 (the ratio was 57.5% caprylic acid + 42.5% myristic acid) low-temperature organic PCM, an energy storage medium, were carried out in a modified oxygen bomb calorimeter. In addition, a one-dimensional model of the solid–liquid two-phase cylindrical PCM solidification process was constructed by numerical simulation. Using the measured time-varying data of the PCM axial temperature, the oxygen bomb surface temperature, and the water temperature of the inner cylinder, the model was applied to approximate the latent heat of phase change of OP24 PCM using a cubic polynomial heat balance integration method. The calculated results were accurate for engineering applications when compared to the values obtained by differential scanning calorimetry. Moreover, the invisible phase interface moving with time could be obtained. The calculation process was relatively simple and convenient for engineering applications. Improving the accuracy of water temperature measurements in the inner cylinder could be the way forward to reduce experimental errors in the determination of the latent heat of phase change in low-temperature PCMs using oxygen bomb calorimetry.
Dynamic mode decomposition of mixing characteristics in a T-junction with a rotation impeller
Authors: Huang Kexin , Li Tong , Su Bo , Lin Mei , Wang Qiuwang
Published: August 2022

Coherent structures of turbulent mixing between cold and hot waters in a T-junction with a rotation impeller with varying blade numbers (Np = 2–4) are studied using the dynamic mode decomposition method. Velocity and temperature fields are obtained using large eddy simulation at the deflecting flow pattern classified by momentum ratio (MR = 0.49). Relevant dynamic features of a flow with low frequency mainly appear near the impeller and those with high frequency appear at the upper and bottom walls. The maximum velocity fluctuation increases with the blade number. Vortex shedding occurs at the blade tips. Spatial structures of the temperature field are mainly distributed at the mixing interface of the two fluids and impeller region. At Np = 2 and 3, energetic coherent structures appear at the bottom wall, while at Np = 4, they appear at the upper and bottom walls. The maximum temperature fluctuation first increases and then decreases with increasing blade number. The frequencies of velocity and temperature modes comprise multiple blade passing frequency (BPF) and rotation frequency, and the effect of rotation frequency on the velocity and temperature modes disappears with increasing the blade number. Furthermore, the frequency of the temperature mode is higher than that of velocity at Np ≤ 3 except for the identical BPF; Np = 4, the two frequencies tend to be more synchronous.
Performance of a hardened x-ray streak camera at Lawrence Livermore National Laboratory’s National Ignition Facility
Authors: MacPhee Andrew G. , Bell Perry M. , Boyle Dusty , Carpenter Arthur C. , Claus Liam , Dayton Matthew , Dean Jack , Dymoke-Bradshaw Anthony K. L. , Durand Cassandra , Funsten Brad , Garafalo Anne , Golick Brad P. , Hares Jonathan D. , Hill Jeremy , Kehl Justin M. , Khan Shahab F. , Kilkenny J. D. , MacDonald Mike J. , Maheshwari Devon , Mccubbin Ian J. , Nagel Sabrina R. , Nyholm Peter R. , Palmer Nathan E. , Petre Robert B. , Sanchez Marcos , Schneider Marilyn B. , Schoelmerich Markus O. , Stoupin Stanislav , Welton Adrianne
Published: August 2022

Electron tubes continue to provide the highest speeds possible for recording dynamics of hot high-energy density plasmas. Standard streak camera drive electronics and CCD readout are not compatible with the radiation environment associated with high DT fusion yield inertial confinement fusion experiments >1013 14 MeV DT neutrons or >109 n cm−2 ns−1. We describe a hardened x-ray streak camera developed for the National Ignition Facility and present preliminary results from the first experiment on which it has participated, recording the time-resolved bremsstrahlung spectrum from the core of an inertial confinement fusion implosion at more than 40× the operational neutron yield limit of the previous National Ignition Facility x-ray streak cameras.
V-cavity stabilized quantum cascade laser-based cavity ringdown spectroscopy for rapid detection of radiocarbon below natural abundance
Authors: Terabayashi Ryohei , Saito Keisuke , Sonnenschein Volker , Okuyama Yuki , Iwamoto Kazuki , Mano Kazune , Kawashima Yuta , Furumiya Tetsuo , Tojo Koji , Ninomiya Shinichi , Yoshida Kenji , Tomita Hideki
Published: August 2022

Mid-infrared laser absorption spectroscopy utilizing a high-finesse optical cavity enables high precision trace analysis of gas molecules. In particular, optical detection of radiocarbon (14C) based on cavity ringdown spectroscopy using a quantum cascade laser (QCL) is gaining attention as an alternative to accelerator mass spectrometry. This paper reports a compact-packaged narrow-linewidth QCL system utilizing resonant optical feedback from an external V-shaped cavity. Based on frequency noise analysis, the derived laser linewidth is 44 kHz for 100 μs integration time with the capability to perform seamless frequency scanning around 10 GHz. We installed this laser system within a table-top cavity ringdown spectrometer for 14CO2. A single-shot detection limit of 1.2 × 10−9 cm−1 Hz−1/2 leading to a detectable abundance evaluated from a noise analysis of 0.2 in fraction modern 14C for a 10-s averaging time was achieved. This capability of rapid analysis for 14CO2 is suitable for various applications requiring trace 14C analysis.
An innovative wide and low-frequency bandgap metastructure for vibration isolation
Authors: Annessi A. , Zega V. , Chiariotti P. , Martarelli M. , Castellini P.
Published: August 2022

Engineering the architecture of materials is a new and very promising approach to obtain vibration isolation properties. The biggest challenge for lattice structures exhibiting vibration isolation properties is the trade-off between compactness and wide and low-frequency bandgaps, i.e., frequency ranges where the propagation of elastic or acoustic waves is prohibited. Here, we, both numerically and experimentally, propose and demonstrate a new design concept for compact metamaterials exhibiting extraordinary properties in terms of wide and low frequency bandgap and structural characteristics. With its 4 cm side length unit cell, its bandgap opening frequency of 1478 Hz, its band-stop filter behavior in the range 1.48–15.24 kHz, and its structural characteristics, the proposed 1×1×3 metastructure represents great progress in the field of vibration isolation and a very promising solution for hand-held vibration probes applications that were unattainable so far through conventional materials.
Superconducting materials: Judge and jury of BCS-electron–phonon theory
Authors: Hirsch J. E.
Published: August 2022

By a recent count, there are 32 different classes of superconducting materials [Physica C: Special Issue, “Superconducting materials: conventional, unconventional and undetermined. Dedicated to Theodore H. Geballe on the year of his 95th birthday,” edited by J. E. Hirsch, M. B. Maple, F. Marsiglio (▪, 2015), Vol. 514, pp. 1–444.], only 12 of which are generally believed to be “conventional,” i.e., described by the conventional BCS-electron–phonon theory of superconductivity. In this Perspective, I critically examine the successes and failures of the conventional theory to describe conventional superconductors and discuss what is understood and not understood about hydrogen-rich materials claimed to be high temperature conventional superconductors under high pressure. I argue that the materials' evidence accumulated to date calls for dethroning the conventional theory of its privileged status and seriously explore the alternative possibility that a single theory, different from the conventional theory, may describe superconductivity of all materials in a unified way.
An electrokinetic preconcentration trapping pattern in electromembrane microfluidics
Authors: Chen Qing , Liu Xiangyong , Lei Yanhua , Zhu Hehua
Published: August 2022

Electrokinetic flows near ion-selective membranes, which produce field amplification and electrokinetic preconcentration, have broad applications in preconcentration engineering since almost all electrochemical chips live in saline surroundings. Despite some published work related to electrokinetic molecular concentration, the electrokinetic trapping pattern has not yet been investigated in previous experimental and theoretical studies. By finite element simulations, the paper is concerned with the transition behavior of the trapping pattern in a membrane-embedded microfluidic channel. Regulating the cross-membrane voltage, Debye number, and surface charge, the local interaction of electric field force and electro-osmotic flow distorts the trapping location, resulting in the realization of a series of trapping patterns switches. We find the transition behavior of the trapping pattern in a membrane-embedded microfluidic channel, from a plateau preconcentration plug outside the vortex to a plug with a Gaussian-like distribution and even to a final spike-like pattern of stagnation points inside the vortex. For a small Debye number, the trapping patterns are characterized by stagnation points, an electrokinetic preconcentration pattern formed inside the vortex, and a concentration with spike-like shapes. Upon increasing the cross-membrane voltage and surface charge, the effect of local vortices can modulate the scaling behavior of enrichment factors at the stagnation points, yet the platform preconcentration plug is basically consistent with the existing experimental observations. These intriguing phenomenological patterns have promising applications in separation, desalination, and electrochemistry.
Dynamic simulation of droplet impacting on superhydrophobic surface with cubic protrusion
Authors: Ai Fanbiao , Li Dong , Shang Yuhe , Wang Jiayong , Shen Leihu
Published: August 2022

Droplet impact dynamics on a superhydrophobic surface with a cubic protrusion was simulated by the lattice Boltzmann method and the contact time reduction mechanism due to the fact that the cubic protrusion was explored. In addition, the droplet bouncing behavior was analyzed with the effect of a wide range of Weber numbers (18.28–106.77). The simulated results showed three distinct bouncing modes, which are bouncing with no ring formation, bouncing with ring formation and disappearance, and bouncing with ring formation. The contact time can be sharply reduced by up to 58.41% as the We number exceeds the critical value 67.16, which is induced by the liquid ring bouncing generated by the collision between the inner and outer rims. In addition, no effect can be seen during the spreading stage, and hence, the liquid ring punctured by the cubic protrusion mainly reduces the retraction time of the droplet impact process. Moreover, the retraction distance can be shortened with the increase in We. Symmetrical dynamics during spreading and retraction due to the cubic protrusion can be seen, which is different from the asymmetric behavior on a macroridge. Discussions on the instantaneous velocity field further support the reduction mechanism of the contact time.
Assessing freshwater fish biodiversity of Kumbe River, Papua (Indonesia) through environmental DNA metabarcoding
Authors: Wibowo Arif , Kurniawan Kurniawan , Atminarso Dwi , Prihadi Tri Heru , Baumgartner Lee J. , Rourke Meaghan L. , Nagai Satoshi , Hubert Nicolas , Vasemagi Anti
Published: August 2022

Context The ability to accurately assess biodiversity is a critical first step towards effective conservation and management. However, assessment of biodiversity using conventional monitoring programs is often constrained by high cost and a lack of taxonomic expertise. Environmental DNA (eDNA) metabarcoding may be a useful tool to efficiently catalogue biodiversity in areas that cannot be easily assessed using other methods. Aims Here, we evaluated the potential of eDNA metabarcoding for assessing fish biodiversity and distribution in the Kumbe River, Papua Province, Indonesia. Methods We selected four sampling locations and collected seven eDNA samples from each location. We used eDNA metabarcoding of the Cytochrome-b gene to characterise the fish community. Key results A total of 23 species were detected, three of which comprised 92% of sequence reads detected: Melanotaenia goldiei (32%), Craterocephalus randi (31%), and the invasive tilapia Oreochromis niloticus (29%). Only five species that were previously detected using conventional methods were detected by metabarcoding: M. goldiei, Craterocephalus stercusmuscarum, O. niloticus, Neoarius graeffei, and Arius arius. We detected 18 species (70% native) that have never been recorded from the Kumbe River. Conclusions This work has demonstrated that fish biodiversity is substantially underestimated in the Kumbe River. Environmental DNA metabarcoding is a promising rapid, non-invasive and cost-effective method for assessing fish biodiversity in Papua. Implications The findings support future investment in eDNA metabarcoding to characterise the fish biodiversity in Papua. This will assist in allocating the limited resources for conservation and management to areas most at risk from anthropogenic impacts.
Language use in an English-medium instruction university in Lebanon
Authors: Iliovits Myriam , Harding Luke , Pill John
Published: August 2022

English-medium instruction (EMI) universities in non-English-dominant contexts often use internationally available tests of English (e.g., TOEFL) and/or locally developed tests to assess the academic English-language proficiency of applicants prior to admission. However, little research has been conducted to establish the extent to which either type of test reflects the real-world classroom discourse, and associated communicative demands, within these often multilingual educational contexts. In this paper, we report on one part of a larger study designed to address this research gap in a particular EMI environment – the American University of Beirut (AUB) in Lebanon. We collected and analysed samples of language use at AUB through non-participant ethnographic observations and video recordings of eight undergraduate classes across academic disciplines. Findings indicated that classes were varied in nature, shifted between registers and levels of interaction, involved a range of translanguaging and English as a Lingua Franca-oriented phenomena, and included meta-commentary about language use. We argue that speaking and listening constructs in English-language admissions tests used in EMI contexts ideally need to be localised or locally developed to best match the unique language use characteristics of these settings.
Rift Valley fever virus: Movement of infected humans threatens global public health and agriculture
Authors: Gibson Seth , Linthicum Kenneth J. , Turell Michal J. , Anyamba Assaf
Published: August 2022

Rift Valley fever (RVF) is an acute disease of ungulate livestock and wildlife as well as humans caused by the Rift Valley fever virus (RVFV), which can be transmitted by arthropod vectors such as mosquitoes as well as by direct contact with infected tissues. Outbreaks of this virus may lead to widespread mortality and morbidity in susceptible ungulates and humans, with pronounced economic and agricultural impacts. Humans infected with RVFV can develop extremely high viremias capable of infecting vectors such as mosquitoes. Critically, RVFV has potential for globalization resulting from the movement of infected humans into non-endemic regions containing populations of potentially competent mosquito vectors and susceptible livestock and wildlife hosts that include the US, Asia, and parts of southern Europe. In this review, we explore scenarios of escape of RVFV from its endemic range that could be caused by the movement of infected humans. The risks of globalization of the RVFV pathogen into Europe, Asia, and the Americas is high and increasing each year because of climate change, redistribution and expanding ranges of vector and host species, lack of an approved human vaccine, insecticide resistance, and international travel and commerce. We discuss approaches that could be used to mitigate these avenues of spread that include surveillance targeted by environmental modeling coupled with decisive vector control.
Composition and organization of kinetochores show plasticity in apicomplexan chromosome segregation
Authors: Brusini Lorenzo , Dos Santos Pacheco Nicolas , Tromer Eelco C. , Soldati-Favre Dominique , Brochet Mathieu
Published: August 2022

Kinetochores are multiprotein assemblies directing mitotic spindle attachment and chromosome segregation. In apicomplexan parasites, most known kinetochore components and associated regulators are apparently missing, suggesting a minimal structure with limited control over chromosome segregation. In this study, we use interactomics combined with deep homology searches to identify 13 previously unknown components of kinetochores in Apicomplexa. Apicomplexan kinetochores are highly divergent in sequence and composition from animal and fungal models. The nanoscale organization includes at least four discrete compartments, each displaying different biochemical interactions, subkinetochore localizations and evolutionary rates across the phylum. We reveal alignment of kinetochores at the metaphase plate in both Plasmodium berghei and Toxoplasma gondii, suggestive of a conserved “hold signal” that prevents precocious entry into anaphase. Finally, we show unexpected plasticity in kinetochore composition and segregation between apicomplexan lifecycle stages, suggestive of diverse requirements to maintain fidelity of chromosome segregation across parasite modes of division.
Few-shot rolling bearing fault classification method based on improved relation network
Authors: Kang Shouqiang , Liang Xintao , Wang Yujing , Wang Qingyan , Qiao Chunyang , Mikulovich V I
Published: August 2022

In practical applications, it is difficult to obtain enough fault samples to train a fault classification model for rolling bearings, and the specifications of bearings used in different mechanical equipment may be different. The diagnosis model trained on a certain specification of bearing may not be applicable to another specification. To solve the above problems, a few-shot rolling bearing fault classification method is proposed, based on an improved relation network (RN). First, a Fourier transform is applied to the vibration signals of different specifications of bearings. The data from different specifications are divided into a meta-train set and a meta-test set according to the meta-learning training strategy, and each set is further divided into a support set and a query set. Second, an improved RN is built. The residual shrinkage module and the scaled exponential linear unit activation function are introduced into the embedding module of the RN. The improved embedding module is used to extract the sample features of the support set and query set, and then the features of the two are combined and input into the relation module to get the relation score. The query set samples are classified according to the score. Finally, the rolling bearing fault classification model is obtained after multiple episodes. The experimental results show that, compared with the partial transfer learning and meta-learning methods, the proposed method only needs a few or even a single sample to achieve the fault classification of different specifications of rolling bearings under different loads. In the case of one-shot, the average classification accuracy can reach 93.3%.
Machine learning to support triage of children at risk for epileptic seizures in the pediatric intensive care unit
Authors: Azriel Raphael , Hahn Cecil D , De Cooman Thomas , Van Huffel Sabine , Payne Eric T , McBain Kristin L , Eytan Danny , Behar Joachim A
Published: August 2022

Objective.Epileptic seizures are relatively common in critically-ill children admitted to the pediatric intensive care unit (PICU) and thus serve as an important target for identification and treatment. Most of these seizures have no discernible clinical manifestation but still have a significant impact on morbidity and mortality. Children that are deemed at risk for seizures within the PICU are monitored using continuous-electroencephalogram (cEEG). cEEG monitoring cost is considerable and as the number of available machines is always limited, clinicians need to resort to triaging patients according to perceived risk in order to allocate resources. This research aims to develop a computer aided tool to improve seizures risk assessment in critically-ill children, using an ubiquitously recorded signal in the PICU, namely the electrocardiogram (ECG).Approach.A novel data-driven model was developed at a patient-level approach, based on features extracted from the first hour of ECG recording and the clinical data of the patient.Main results.The most predictive features were the age of the patient, the brain injury as coma etiology and the QRS area. For patients without any prior clinical data, using one hour of ECG recording, the classification performance of the random forest classifier reached an area under the receiver operating characteristic curve (AUROC) score of 0.84. When combining ECG features with the patients clinical history, the AUROC reached 0.87.Significance.Taking a real clinical scenario, we estimated that our clinical decision support triage tool can improve the positive predictive value by more than 59% over the clinical standard.
The possibility of creating narrow beams of high-energy gamma quanta in the process of resonant spontaneous bremsstrahlung radiation of ultrarelativistic electrons on nuclei in strong electromagnetic fields
Authors: Roshchupkin S P , Dubov A V , Starodub S S
Published: August 2022

The production of narrow beams of high-energy gamma quanta in the process of resonant spontaneous bremsstrahlung radiation of ultrarelativistic electrons on nuclei in strong electromagnetic fields is predicted. This effect is realized under special experimental conditions for the frequencies and intensities of the laser installation. Resonant differential cross sections with simultaneous registration of the outgoing angle and the energy of the spontaneous gamma quantum, as well as a small number of absorbed photons of the wave, can exceed the corresponding differential cross section without an external field by 18–19 orders of magnitude. The obtained results can be used to obtain narrow beams of high-energy gamma quanta, as well as to explain high-energy gamma quanta near pulsars and magnetars.
Spectral distortions from axion monodromy inflation
Authors: Henríquez-Ortiz Raúl , Mastache Jorge , Ramos-Sánchez Saúl
Published: August 2022

With the advent of new missions to probe spectral distortions of the cosmic microwave background with unprecedented precision, the study of theoretical predictions of these signals becomes a promising avenue to test our description of the early Universe. Meanwhile, axion monodromy still offers a viable framework to describe cosmic inflation. In order to explore new constraints on inflationary models based on axion monodromy while aiming at falsifying this scenario, we compute the spectral distortions predicted by this model, revealing oscillatory features that are compatible with Planck data. Further, the predicted distortions are up to 10% larger than the signals obtained from the fiducial ΛCDM model and are observable in principle. However, contrasting with the predictions of the simplest power-law inflationary potentials challenges the falsifiability of axion monodromy as it would require to reduce at least 100 times the current forecast error of the PIXIE satellite, which shall be possible at some projected observational setups.
Constraints on horizonless objects after the EHT observation of Sagittarius A*
Authors: Carballo-Rubio Raúl , Di Filippo Francesco , Liberati Stefano , Visser Matt
Published: August 2022

The images of Sagittarius A* recently released by the Event Horizon Telescope collaboration have been accompanied [
Astrophys. J. Lett.
930 (2022) L17]
by an analysis of the constraints on the possible absence of a trapping horizon, i.e. on the possibility that the object at the center of our galaxy is an ultra-compact object with a surface re-emitting incident radiation. Using the observed image size and the broadband spectrum of Sgr A*, it is claimed that the radius of any surface, in which incident radiation is re-emitted thermally, is strongly bounded from above by these latest observations. Herein, we discuss how the reported constraint relies on the extremely strong assumption of perfect balance in the energy exchange between the accretion disk and the central object, and show that this is violated whenever the surface is endowed with any non-zero absorption coefficient. We derive the upper-bound constraints that can be cast on the radius and dimensionless absorption coefficient of the surface. We show that the conclusions of the analysis presented by the EHT collaboration hold only for unnaturally small values of the absorption coefficient (i.e. much lower than 10-14), and thus have to be significantly revised in scenarios with physical significance.
Velocity-dependent annihilation radiation from dark matter subhalos in cosmological simulations
Authors: Piccirillo Erin , Blanchette Keagan , Bozorgnia Nassim , Strigari Louis E. , Frenk Carlos S. , Grand Robert J.J. , Marinacci Federico
Published: August 2022

We use the suite of Milky Way-like galaxies in the Auriga simulations to determine the contribution to annihilation radiation from dark matter subhalos in three velocity-dependent dark matter annihilation models: Sommerfeld, p-wave, and d-wave models. We compare these to the corresponding distribution in the velocity-independent s-wave annihilation model. For both the hydrodynamical and dark-matter-only simulations, only in the case of the Sommerfeld-enhanced annihilation does the total annihilation flux from subhalos exceed the total annihilation flux from the smooth halo component within the virial radius of the halo. Progressing from Sommerfeld to the s, p, and d-wave models, the contribution from the smooth component of the halo becomes more dominant, implying that for the p-wave and d-wave models the smooth component is by far the dominant contribution to the radiation. Comparing to the Galactic center excess observed by Fermi-LAT, for all simulated halos the emission is dominated by the smooth halo contribution. However, it is possible that for Sommerfeld models, extrapolation down to mass scales below the current resolution limit of the simulation would imply a non-negligible contribution to the gamma-ray emission from the Galactic Center region.