bluuebunny/crossref_metadata_2025 huggingface dataset:
Correction: Method for extraction and analysis of per- and poly-fluoroalkyl substances in contaminated asphalt
Authors: Srivastava Prashant , Williams Mike , Du Jun , Navarro Divina , Kookana Rai , Douglas Grant , Bastow Trevor , Davis Greg , Kirby Jason K.
Published: August 2022

Correction for ‘Method for extraction and analysis of per- and poly-fluoroalkyl substances in contaminated asphalt’ by Prashant Srivastava et al., Anal. Methods, 2022, 14, 1678–1689, https://doi.org/10.1039/D2AY00221C.
Cascade reaction of o-enoyl arylisocyanide and o-hydroxy aromatic aldimine: diastereoselective access to a polycyclic spirobenzoxazine chromeno[4,3-b]pyrrole derivative
Authors: Xiao Yao , Peng Xin , Shen Jie , Cui Lei , Lu Shanya , Jia Xueshun , Li Chunju , Li Jian
Published: August 2022

A series of structurally unusual spirobenzoxazine chromeno[4,3-b]pyrrole derivatives have been efficiently constructed. This domino transformation forms successively three new rings and provides a fast and economic strategy.
Planar inorganic five-membered heterocycles with σ + π dual aromaticity in both S0and T1states
Authors: Gu Xiaojiao , Yang Le , Jin Peng
Published: August 2022

Density functional theory calculations reveal that several planar inorganic five-membered rings may have unprecedented adaptive σ + π dual aromaticity.
Gas phase synthesis and adsorption properties of a 3D ZIF-8 CNT composite
Authors: Dönges Inga , Büschges M. Isabelle , Njel Christian , Schneider Jörg J.
Published: August 2022

Gas phase transformation of ZnO on vertically aligned CNTs (VACNTs) into ZIF-8 particles on VACNTs is achieved by direct reaction with 2-methylimidazole. The composite shows attractive gas adsorption properties over a wide pressure regime.
Research progress of modified natural zeolites for removal of typical anions in water
Authors: Lu Wenjing , Zhang Chunhui , Su Peidong , Wang Xinling , Shen Wenlong , Quan Bingxu , Shen Zhelin , Song Lei
Published: August 2022

The mechanism of natural zeolites for modification and the removal of anions.
Photothermal catalytic CO2 oxidative dehydrogenation of propane to propylene over BiOX (X = Cl, Br, I) nanocatalysts
Authors: He Zhen-Hong , Wu Bao-Ting , Wang Zhong-Yu , Yang Shao-Yan , Wang Kuan , Shi Jiao-Jiao , He Meng-Xin , Wang Weitao , Liu Zhao-Tie
Published: August 2022

BiOI nanosheets could catalyze the photothermal catalytic CO2 oxidative dehydrogenation of propane to propylene.
A heterochiral diphenylalanine auxin derivative empowers remarkable mechanical integrity with promising Antiinflammatory and Antimicrobial Performances
Authors: Khan Naureen , Gupta Arindam , Shivhare Vaibhav , Ahuja Rishabh , Varshney Mayank , Basu Anindya , DuttKonar Anita
Published: August 2022

A proteolytically stable, biocompatible hydrogel has been developed with a heterochiral diphenylalanine auxin derivative that displayed excellent mechanical integrity & pharmacological properties at room temperature at physiological pH.
Design of planar-zigzag semiconducting polymers to control chain orientation and electronic structure for organic photovoltaics
Authors: Chen Fengkun , Nakano Kyohei , Kaji Yumiko , Tajima Keisuke
Published: August 2022

The planar-zigzag shape of polymers leads to a face-on orientation of the main chains in thin films which improves the photovoltaic performance through better absorption coefficients, charge carrier generation, and collection efficiency.
Charge transfer complex enabled photoreduction of Wittig phosphonium salts
Authors: Tan Fang , Zheng Peng , Liu Qiang , Chen Xiang-Yu
Published: August 2022

An efficient photoactive charge transfer complex protocol for the (alkoxycarbonyl)methylation reaction of alkenes with phosphonium salts is established.
Rhodium-catalysed regioselective [4 + 2]-type annulation of 1-H-indazoles with propargyl alcohols: direct access to 6-alkenylindazolo[3,2-a]isoquinolines
Authors: Zhao Xiang , Yue Xuelin , Han Zeng , Feng Yadong , Gao Ting , Li Sanshu , Cui Xiuling
Published: August 2022

A method for the synthesis of 6-alkenylindazolo[3,2-a]isoquinolines via Rh(iii)-catalysed C–H bond activation/cyclization has been developed. The title products exhibited favourable fluorescence properties which were verified by relevant experiments.
A sensitive isothermal fluorescence biosensor for microRNA detection coupling primer exchange reaction with catalytic hairpin assembly
Authors: Liu Jiatong , Shen Minzhe , Talap Jadera , Shen Xudan , Song Zihan , Hu Haihong , Zeng Su , Cai Sheng
Published: August 2022

A novel biosensor for sensitive detection of miRNAs was established based on coupling the primer exchange reaction (PER) with catalytic hairpin assembly (CHA).
Model biomolecular condensates have heterogeneous structure quantitatively dependent on the interaction profile of their constituent macromolecules
Authors: Shillcock Julian C. , Lagisquet Clément , Alexandre Jérémy , Vuillon Laurent , Ipsen John H.
Published: August 2022

Model biomolecular condensates have heterogeneous material properties that are tuned by the number and distribution of their constituent proteins’ sticky binding sites.
Correlating light-induced deep defects and phase segregation in mixed-halide perovskites
Authors: Ridzoňová Katarína , Grill Roman , Peter Amalathas Amalraj , Dzurňák Branislav , Neykova Neda , Horák Lukáš , Fiala Peter , Chin Xin Yu , Wolff Christian M. , Jeangros Quentin , Holovský Jakub
Published: August 2022

The correlation between rate of light-induced phase segregation and deep defect formation observed in mixed-halide perovskites. The importance of grain size in determining the rate and terminal phase of segregation was highlighted.
Recent advancements in poly-Si/SiOxpassivating contacts for high-efficiency silicon solar cells: technology review and perspectives
Authors: Zhou Jiakai , Su Xianglin , Huang Qian , Zhang Bike , Yang Jie , Zhao Ying , Hou Guofu
Published: August 2022

The paper provides an outline of the present status in lab and industry of TOPCon structure. Additionally, this review discusses the remaining hurdles and the promise with the aim of providing guidance for the development of TOPCon solar cells.
Mechanically robust all-polymer solar cells enabled by polymerized small molecule acceptors featuring flexible siloxane-spacers
Authors: Lee Jin-Woo , Lee Sun-Woo , Kim Jingwan , Ha Yeon Hee , Sun Cheng , Ngoc-Lan Phan Tan , Lee Seungjin , Wang Cheng , Kim Taek-Soo , Kim Yun-Hi , Kim Bumjoon J.
Published: August 2022

New polymer acceptors (PYSiO-X (X = 0–30%)) containing siloxane-based flexible spacers (SiO-FSs) are developed. The resulting halogen-free solvent processed all-polymer solar cells show high photovoltaic efficiency and mechanical robustness.
Enhanced photodetection and a wider spectral range in the In2S3–ZnO 2D–3D heterojunction: combined optical absorption and enhanced carrier separation at the type-II heterojunction
Authors: Kaur Narinder , Ghosh Abhishek , Bisht Prashant , Kumar Arvind , Kaushik Vishakha , Kodan Nisha , Singh Rajendra , Mehta B. R.
Published: August 2022

The In2S3–ZnO heterojunction with a sandwich geometry shows a high photocurrent density value of 0.25 mA cm−2 at 1 V.
Effect of photoionisation on initial discharge in air under nanosecond pulse voltage
Authors: Li Yutai , Fu Yangyang , Liu Zhigang , Li Handong , Wang Peng , Luo Haiyun , Zou Xiaobing , Wang Xinxin
Published: August 2022

Effects of photoionisation on the development and electron runaway of the initial discharge in atmospheric air under nanosecond pulse voltage were studied via two‐dimensional particle‐in‐cell/Monte Carlo collision simulations. It was found that photoionisation has little effect at the beginning of the initial discharge. However, as the discharge channel gradually develops towards the anode, photoionisation shows greater impacts on the morphology of discharge but has little influence on the velocity of discharge development. Photoionisation does not appear to have a decisive effect on the growth trend of the highest energy of runaway electrons, but it does affect the change rate of the highest energy and overall distribution of electron energy, resulting in a higher proportion of energetic electrons. The difference in the distributions of the electron energy between the two cases, with and without considering photoionisation, can be attributed to the impact of photoionisation on the discharge morphology, which in turn distorted the electric field. The spatial density distributions of the electrons produced by photoionisation further explained the differences. The authors’ results explicitly demonstrate the influence of photoionisation on the development and the electron runaway of the initial discharge under nanosecond pulse voltage, which provides more comprehensive knowledge for the atmospheric air gap nanosecond pulse discharge physics.
Small Modular Reactor-based solutions to enhance grid reliability: impact of modularization of large power plants on frequency stability
Authors: Boudot Charly , Droin Jean-Baptiste , Sciora Pierre , Besanger Yvon , Robisson Bruno , Mazauric Anne-Laure
Published: August 2022

In the current renewable energies’ expansion framework, the increasing part of intermittent electricity production sources (solar or wind farms) in the energy mix and the reducing part of thermal power stations that are nowadays useful to ensure grid stability will lead to a complete paradigm shift concerning the means to ensure grid stability. Nuclear energy, which is carbon-free and dispatchable, may be a sustainable solution to this grid reliability issue if it is adequately designed and implemented on the grid. Several solutions aiming at improving the future nuclear power flexibility are currently under investigation in the literature, among them are those based on Small Modular Reactor (SMR) plants. In order to demonstrate their potential ability to stabilize electric grids, it is necessary to perform electrical dynamic simulations taking into account a spatial and temporal discretization of the grid. In this paper, such calculations are performed using the PowerFactory software. This tool can reproduce electrical grids thanks to models of turbo generators, lines, transformers, loads, I&C systems, etc. The objective is to assess to what extent the innovative SMR features may enhance the frequency control of a grid. For this purpose, a short-circuit event and three frequency stability criteria are firstly defined. Then, a verification of the correct behaviour of the IEEE 39-bus (or New England) grid with regulations is carried out. The relevance of implementing Small Modular Reactors (SMR) instead of large power plants on such frequency stability criteria on this grid is finally assessed, in order to conclude in a preliminary way the possible contribution of small reactors to the future grid’s sustainability.
Design of interdigitated transducers for acoustofluidic applications
Authors: Song Shuren , Wang Qi , Zhou Jia , Riaud Antoine
Published: August 2022

Interdigitated transducers (IDTs) were originally designed as delay lines for radars. Half a century later, they have found new life as actuators for microfluidic systems. By generating strong acoustic fields, they trigger nonlinear effects that enable pumping and mixing of fluids, and moving particles without contact. However, the transition from signal processing to actuators comes with a range of challenges concerning power density and spatial resolution that have spurred exciting developments in solid-state acoustics and especially in IDT design. Assuming some familiarity with acoustofluidics, this paper aims to provide a tutorial for IDT design and characterization for the purpose of acoustofluidic actuation. It is targeted at a diverse audience of researchers in various fields, including fluid mechanics, acoustics, and microelectronics.
Significant quantum yield enhancement for near infrared fluorescence dyes by silica templated silver nanorods
Authors: Xu Jiamin , Morton William , Jones Daniel , Tabish Tanveer A. , Ryan Mary P , Xie Fang
Published: August 2022

Silver's inherent optical properties of low absorption cross section, over a broad wavelength range, makes it an attractive material for use in biosensing. We report herein a unique silica template method to synthesize cetrimonium bromide free silver nanorods (AgNRs). The application of AgNRs in metal enhanced fluorescence (MEF) was explored by immobilizing visible/near-infrared (NIR) fluorescent dyes on AgNR assembled substrates exhibiting broadband optical properties. Theoretical modeling was performed to analyze the nanoscale “chaotic nature” of the AgNR substrates, showing that the plasmon band shifts and broadening were attributed to the resonance coupling between assembled nanorods with different conformations. The quantum yield (QY) of NIR dye Alex Fluor 790 was increased dramatically from 4% to 84%, with total fluorescence enhancement up to two orders of magnitudes. In addition, AgNR substrates can also amplify fluorescence emissions from high quantum yield dyes, nearly 10-fold for Alexa Fluor 647 (QY:33%) and threefold for Alexa Fluor 488 (QY:92%). The AgNR demonstrates the capability of dramatically enhancing NIR dye's QY, holding great potential for building up an ultra-sensitive fluorescence bioassay platform for early diagnosis of diseases.
Enhanced deep-tissue photoacoustics by using microcomposites made of radiofrequency metamaterials and soft polymers: Double- and triple-resonance phenomena
Authors: Abraham-Ekeroth Ricardo Martín
Published: August 2022

Photoacoustic imaging systems offer a platform with high resolution to explore body tissues, food, and artwork. On the other hand, plasmonics constitutes a source of resonant heating and thermal expansion to generate acoustic waves. However, its associated techniques are seriously limited to laser penetration and nonspecific hyperthermia in the sample. To address this issue, the present work adopts a paradigm shift in photoacoustics. By simulating microparticles made of random composites, the calculated pressure can be made similar or superior to that calculated via plasmonic optoacoustics. The improvement is due to a phenomenon called double or triple resonance, which is the excitation of one or both electric and magnetic plasmons within radiofrequency range and the simultaneous excitation of the particle’s acoustic mode. Given that electromagnetic pulses are restricted to nanosecond pulse widths and MHz frequencies, the proposed method overcomes the poor penetration in tissues and reduces thermal damage, thereby offering a noninvasive technique of theragnosis. Moreover, the resonant pressure obtained lasts longer than with conventional photoacoustic pressure, providing a central feature to enhance detection. To fully comprehend the multi-resonance framework, we develop a complete photoacoustic solution. The proposed approach could pave the way to thermoacoustic imaging and manipulation methods for sensitive materials and tissues with micrometer resolution.
ABC-like flows on the 3-torus
Authors: Marciu Mihai , Slobodeanu Radu
Published: August 2022

We introduce a 3-parameter family of vector fields on the 3-torus as a linear combination of unit eigenfields of the curl operator for the eigenvalue 2. For this family reminiscent of the classical ABC flow, we study the existence of stationary points, we give numerical evidence for the existence of chaotic regions, and we present an integrable case. Our main result is that the non-vanishing members of the family are associated with tight contact structures.
Straining of atomically thin WSe2 crystals: Suppressing slippage by thermal annealing
Authors: Hu Wenshuai , Wang Yabin , He Kexin , He Xiaolong , Bai Yan , Liu Chenyang , Zhou Nan , Wang Haolin , Li Peixian , Ma Xiaohua , Xie Yong
Published: August 2022

The atomically thin two-dimensional (2D) transition-metal dichalcogenide (e.g., MoS2) material can withstand large strains up to 11% to change its energy band structure, thereby further tuning its optical, electrical, and other physical properties. However, the slippage of 2D materials on substrate hammers the further strain tuning of the properties of 2D materials. Hereby, a facile three points approach combined with a dry transfer method that can apply uniaxial strain to two-dimensional materials is provided. The slippage of WSe2 on polycarbonate (PC) substrate can be suppressed by thermally annealing WSe2/PC in low pressure Ar atmosphere above 100 °C for 3 h. Straining cycle evolution experiments revealed that the thermal annealing of (1L) WSe2 could suppress slippage from the surface of the PC. The spectral gauge factor of 1L WSe2 is found to be around -60 meV/%. After thermal treatment, WSe2/PC stacking can survive in DI water for at least 24 h without the degradation of the spectral gauge factor. Dome structures are formed after thermal treatments with the interplay of the viscoelasticity and surface tension of the PC and the 0.4% tensile strain on WSe2, and the RMS roughness of WSe2/PC increased from 820 to 1292 pm, indicating that there could be larger lateral friction force to suppress slippage following thermal annealing. Our findings enrich the strain engineering of 2D materials and their device applications.
A new class of approximate analytical solutions of the Pridmore-Brown equation
Authors: Krpensky A. , Hruska V. , Bednarik M.
Published: August 2022

There is only a limited amount of known analytical solutions to the Pridmore-Brown equation, mostly employing asymptotic behavior for a certain frequency limit and specifically chosen flow profiles. In this paper, we show the possibility of transformation of the Pridmore-Brown equation into the Schrödinger-like equation for the case of two-dimensional homentropic mean flow without critical layers. The corresponding potential that depends on the mean flow profile can then be approximated by a quartic polynomial, leading to a triconfluent Heun equation whose solution based on the triconfluent Heun functions is generally known. The quality of this approximation procedure is presented for the case of symmetric polynomial flow profiles for various values of polynomial order and the Mach number. A more detailed example is then shown for a quadratic mean flow profile, where the solution is accurate up to the third order of the Mach number.
Mechanical properties and pore structure of basalt–polypropylene fiber fly ash concrete exposed to high temperatures
Authors: Zheng Qianqian , Zhang Jingshuang
Published: August 2022

The deterioration of concrete structures after fires has been widely concerned. The purpose of this paper is to study the influence of high temperature on the mechanical properties and pore structure of hybrid basalt–polypropylene fiber fly ash concrete. The mechanical properties and damage amount of hybrid basalt–polypropylene fiber concrete with different content of fly ash (FA0, FA10, FA20, and FA30) at different temperatures (20, 200, 400, 600, and 800 °C) were investigated. Additionally, the pore structure test was conducted, and the relationship between pore structure parameters and macromechanical properties was analyzed. The microstructure at different temperatures was observed by scanning electron microscopy (SEM) images. Finally, the main pore structure parameters affecting compressive strength, tensile strength, and damage amount were determined by using the gray correlation entropy method. From the results, after natural cooling at 200 °C, the compressive and tensile strength of concrete was slightly higher than that at room temperature, and it should be noticed that the FA10 concrete specimen showed better mechanical properties at different temperatures compared with other specimens. The increase in air content, spacing factor, and average chord length weakened the strength of concrete, while the increase in specific surface area had a positive impact on the compressive and tensile strength of concrete. The microstructure of FA10 at high temperature was better than that of FA0. The specific surface area was the main factor affecting the compressive and tensile strength, while the main factor affecting the damage amount was the spacing factor, followed by the average chord length.
Learning to transmit images through optical speckle of a multimode fiber with high fidelity
Authors: Tang Pusong , Zheng Kanpei , Yuan Weiming , Pan Tuqiang , Xu Yi , Fu Songnian , Wang Yuncai , Qin Yuwen
Published: August 2022

Multimode fibers provide a unique opportunity for exploring the spatial degrees of freedom for high throughput light transmission. However, the modal dispersion prevents from the straightforward application of multimode fibers for space division multiplexing, such as image transmission. Herein, we propose and experimentally demonstrate a deep neural network termed multimode fiber inverse-scattering net for overcoming the modal dispersion induced scrambling in multimode fibers. Such a network is capable of transmitting grayscale image through the multimode fiber with high fidelity. 256-level grayscale images with 128 × 128 spatial channels encoded in the input wavefront can be retrieved from the output optical speckle patterns, where the average Pearson correlation coefficient and structural similarity index are as large as 0.97 and 0.95, respectively. Our results demonstrate that the proposed deep neural network has an excellent ability for learning the relationship between the input and output optical fields of a multimode fiber, which might facilitate the realization of high throughput space division multiplexing through multimode fibers.
Binary image classification using collective optical modes of an array of nanolasers
Authors: Tirabassi Giulio , Ji Kaiwen , Masoller Cristina , Yacomotti Alejandro M.
Published: August 2022

Recent advancements in nanolaser design and manufacturing open up unprecedented perspectives in terms of high integration densities and ultra-low power consumption, making these devices ideal for high-performance optical computing systems. In this work, we exploit the symmetry properties of the collective modes of a nanolaser array for a simple binary classification task of small digit images. The implementation is based on a 8 × 8 nanolaser array and relies on the activation of a collective optical mode of the array—the so-called “zero-mode”—under spatially modulated pump patterns.
Constrained model calibration of grain structure dependent spall dynamics in shock-loaded tantalum
Authors: Beach Kory , Horwitz Jeremy A. K. , Maich Alyssa , White Elida , Ramos Dane , Crum-Friedman Ryan S. , Akin Minta , Najjar Fady M.
Published: August 2022

We perform a gas gun experiment by shock loading tantalum samples of varying grain structures to assess the suitability of a numerical model for simulating spall behavior. The observed differences in spall strength, as well spallation and re-compression history, are not captured in uncalibrated hydrodynamic simulations. An optimization is performed on the Johnson spall model to determine the best parameters that fit the observed trends. Linear stability analysis is employed to motivate bounds on those parameters. Herein, optimized simulations agree well with the experimental results, reproducing pullback depth and recompression timescales across the different samples tested. Further, the observed pullback time of the single crystal sample was found to imply, via the stability analysis, a percolation threshold in good agreement with the theoretical value for a body centered cubic lattice. Therefore, the combined linear stability and percolation analysis shows promise and may be applied to other materials with diverse microstructures. Collectively, the findings demonstrate that the model is suitable for reproducing spall-induced free surface behavior across various microstructures, but also points to caution in using model coefficients for uncalibrated microstructures.
Onset of convection in internally heated fluids with strongly temperature-dependent viscosity
Authors: Jain C. , Solomatov V. S.
Published: August 2022

We investigate the onset of convection in internally heated fluids with strongly temperature-dependent viscosity by solving numerically a non-linearized system of thermal convection equations in two dimensions for viscosity contrasts up to ∼1035. As the viscosity contrast increases, a high-viscosity stagnant lid develops at the upper surface and convection occurs in a sublayer beneath it. The transition to stagnant-lid convection occurs at about the same viscosity contrast as in Rayleigh–Bénard convection. We obtain asymptotic scaling relationships for the critical Rayleigh number and other parameters in the stagnant-lid regime. We also investigated the possibility of subcritical convection. In contrast to the Rayleigh–Bénard problem, we did not detect a subcritical region for internally heated convection in two-dimensional simulations. The results of this study can help improve our understanding of the conditions under which convection occurs in planetary interiors.
Lock-in phenomenon in the wake flow past an oscillating circular nano-cylinder
Authors: Zhu Yanqi , Jin Hanhui , Guo Yu , Ku Xiaoke , Fan Jianren
Published: August 2022

In this paper, the lock-in/synchronization phenomenon in the wake flow around an oscillating nano-cylinder is studied with molecular dynamics simulation. The results show that the lock-in valley of the velocity fluctuation also occurs in nano-scale. Similar to those in normal scales (usually >1 mm), three regimes of lock-in, transition, and no-lock-in states are also obtained. Unlike in normal scales, the concurrence of the density and velocity fluctuation waves with different phase and the same frequency makes the fluctuation frequency of the lift force different from that of the velocity. The oscillation of the nano-cylinder can intensify the lift force fluctuation, especially in the lock-in state. The intensity of the lift force increases with the amplitude of the nano-cylinder vibration. The lock-in valley of the lift force usually covers a wider range of frequency than that of the velocity. Improving the inflow Reynolds number can reduce the coverage range of the lock-in valley in frequency. The lock-in valley does not vary apparently as the Jz number, which represents the interaction intensity between fluid molecules, increases until it approaches Jz ≈ 1.4. The rise of Kn number can promote the occurrence of the lock-in phenomenon.
Facile synthesis of core–shell structured C/Fe3O4 composite fiber electromagnetic wave absorbing materials with multiple loss mechanisms
Authors: Dai Bushi , Qi Yang , Song Mengjie , Zhang Bowen , Wang Nan , Dai Yuxiang
Published: August 2022

The use of heterostructures in electromagnetic wave absorption applications has been limited by the problem of homogeneous dispersion in composites. In this study, three-dimensional (3D) cross-linked electromagnetic wave absorbing composites with the carbon nanofiber/Fe3O4 (CNF/Fe3O4) core–shell structure were synthesized by expanding the interface of the heterogeneous structure with Fe3O4 nanocrystals uniformly modified on the surface of the carbon nanofiber. The 3D cross-linked structure of the composites contributes to the generation of conductive loss and macroscopic eddy current loss. The heterogeneous interface formed by graphite nanocrystals and amorphous carbon in the carbon nanofiber is identified by high-resolution transmission electron microscopy and Raman spectroscopy as having a strong electromagnetic wave absorption capacity for boundary-type defects. The Fe3O4 nanocrystal particles on the surface of the carbon nanofiber not only have the strong magnetic loss capability of magnetic materials but also form a new heterogeneous interface with the carbon nanofiber surface, which further enhances the interfacial polarization of the composite and improves the electromagnetic wave absorption properties. With the synergistic effects of interfacial polarization, macroscopic and microscopic eddy current losses, conductive losses, and magnetic losses, the electromagnetic wave absorption performance of the composites is further enhanced based on the carbon nanofiber. The reflection loss reaches −51.11, −42.99, and −55.98 dB at 9, 12 (X-band), and 17 GHz (Ku-band), respectively, corresponding to the thicknesses of 2.0, 1.5, and 1.0 mm. In addition, the widest effective absorption bandwidth is 3.3 GHz at 14.7–18 GHz (only 1.09 mm).
Sequence capture data support the taxonomy of
Authors: Schmidt-Lebuhn Alexander N.
Published: August 2022

Variation in breeding systems between species of the same taxonomic group complicates the consistent application of species concepts, and perhaps even the logically consistent circumscription of species. Several genera of arid-zone ephemerals in the Angianthus clade (Asteraceae: Gnaphalieae: Gnaphaliinae) contain both outcrossing and non-outcrossing species. The latter are recognised by producing an order of magnitude fewer pollen grains per anther and an often reduced number of corolla lobes, and they are frequently more widespread than are the former. In its current taxonomy, the genus Pogonolepis comprises an otherwise morphologically indistinguishable pair of one outcrossing and one non-outcrossing species. I generated sequence capture data to test the genetic segregation of P. stricta and P. muelleriana and the utility of sequence capture data for species circumscription and diagnostics. Phylogenetic analysis showed the two species to form two specimen clades, supporting the current taxonomy. Contrary to expectations, non-outcrossing P. muelleriana exhibited lower gene concordance, in line with values expected from recombination, as well as higher heterozygosity than its outcrossing sister species. More research on the breeding system and population structure of the two species may be required to explain these results.
A new perspective on ecological vulnerability and its transformation mechanisms
Authors: Hou Kang , Tao Wendong , He Dan , Li Xuxiang
Published: August 2022

Ecological vulnerability refers to the degree of ecosystem disturbance, system damage, and the ability of system restoration. Although case-specific evaluations of ecological vulnerability are progressing rapidly, they have been carried out mainly in areas with intensive human activities or in harsh natural environments. Using the Web of ScienceTM core collection, this review paper summarized studies on ecological vulnerability published from 2000 to 2022 and analyzed in depth major case studies. It was found that traditional ecological vulnerability research has been addressed largely in terms of assessment models, data processing models, and analysis of influencing factors, however there was a lack of research on the process of vulnerability transformation. Because the vulnerability transformation in a hierarchical vulnerability index system is regulated by multiple factors in a heterogeneous region, it is urgent to understand how the ecological vulnerability in a region evolves from one level to another over time. Therefore this paper put forward the new perspective of research, i.e., applying quantitative analysis to identification of regulating factors and exploring the mechanisms of ecological vulnerability transformation. This new perspective could assist in monitoring the complex spatiotemporal changes in ecological vulnerability and taking necessary measures to prevent from decline of ecological stability.
Solution of an acoustic transmission inverse problem by extended inversion
Authors: Symes William W , Chen Huiyi , Minkoff Susan E
Published: August 2022

Study of a simple single-trace transmission example shows how an extended source formulation of full-waveform inversion can produce an optimization problem without spurious local minima (‘cycle skipping’), hence efficiently solvable via Newton-like local optimization methods. The data consist of a single trace extracted from a causal pressure field, propagating in a homogeneous fluid according to linear acoustics, and recorded at a given distance from a transient point energy source. The source intensity (‘wavelet’) is presumed quasi-impulsive, with zero energy for time lags greater than a specified maximum lag. The inverse problem is: from the recorded trace, recover both the sound velocity or slowness and source wavelet with specified support, so that the data is fit with prescribed RMS relative error. The least-squares objective function has multiple large residual minimizers. The extended inverse problem permits source energy to spread in time, and replaces the maximum lag constraint by a weighted quadratic penalty. A companion paper shows that for proper choice of weight operator, any stationary point of the extended objective produces a good approximation of the global minimizer of the least squares objective, with slowness error bounded by a multiple of the maximum lag and the assumed noise level. This paper summarizes the theory developed in the companion paper and presents numerical experiments demonstrating the accuracy of the predictions in concrete instances. We also show how to dynamically adjust the penalty scale during iterative optimization to improve the accuracy of the slowness estimate.
On the use of nonlinear anisotropic diffusion filters for seismic imaging using the full waveform
Authors: Métivier L , Brossier R
Published: August 2022

Nonlinear anisotropic diffusion filters have been introduced in the field of image processing for image denoising and image restoration. They are based on the solution of partial differential equations involving a nonlinear anisotropic diffusion operator. From a mathematical point of view, these filters enjoy attractive properties, such as minimum–maximum principle, and an inherent decomposition of the images in different scales. We investigate in this study how these filters can be applied to help solving data-fitting inverse problems. We focus on seismic imaging using the full waveform, a well known nonlinear instance of such inverse problems. In this context, we show how the filters can be applied directly to the solution space, to enhance the structural coherence of the parameters representing the subsurface mechanical properties and accelerate the convergence. We also show how they can be applied to the seismic data itself. In the latter case, the method results in an original low-frequency data enhancement technique making it possible to stabilize the inversion process when started from an initial model away from the basin of attraction of the global minimizer. Numerical results on a 2D realistic synthetic full waveform inversion case study illustrate the interesting properties of both approaches.
A new approach to COVID-19 detection from x-ray images using angle transformation with GoogleNet and LSTM
Authors: Kaya Yılmaz , Yiner Züleyha , Kaya Mahmut , Kuncan Fatma
Published: August 2022

Declared a pandemic disease, COVID-19 has affected the lives of millions of people and had significant effects on public health. Despite the development of effective vaccines against COVID-19, cases continue to increase worldwide. According to studies in the literature, artificial intelligence methods are used effectively for the detection of COVID-19. In particular, deep-learning-based approaches have achieved very good results in clinical diagnostic studies and other fields. In this study, a new approach using x-ray images is proposed to detect COVID-19. In the proposed method, the angle transform (AT) method is first applied to the x-ray images. The AT method proposed in this study is an important novelty in the literature, as there is no such approach in previous studies. This transformation uses the angle information created by each pixel on the image with the surrounding pixels. Using the AT approach, eight different images are obtained for each image in the dataset. These images are trained with a hybrid deep learning model, which combines GoogleNet and long short-term memory (LSTM) models, and COVID-19 disease detection is carried out. A dataset from the Mendeley database is used to test the proposed approach. A high classification accuracy of 98.97% is achieved with the AT + GoogleNet + LSTM approach. The results obtained were also compared with other studies in the literature. The presented results reveal that the proposed method is successful for COVID-19 detection using chest x-ray images. Direct transfer methods were also applied to the data set used in the study. However, worse results were observed according to the proposed approach. The proposed approach has the flexibility to be applied effectively to different medical images.
Gas distribution by EIT during PEEP inflation: PEEP response and optimal PEEP with lowest trans-pulmonary driving pressure can be determined without esophageal pressure during a rapid PEEP trial in patients with acute respiratory failure
Authors: Grivans Christina , Stenqvist Ola
Published: August 2022

Objective. Protective ventilation should be based on
lung
mechanics and transpulmonary driving pressure (ΔPTP), as this ‘hits’ the lung directly. Approach. The change in end-expiratory lung volume (ΔEELV) is determined by the size of the PEEP step and the elastic properties of the lung (EL), ΔEELV/ΔPEEP. Consequently, EL can be determined as ΔPEEP/ΔEELV. By calibration of tidal inspiratory impedance change with ventilator inspiratory tidal volume, end-expiratory lung impedance changes were converted to volume changes and lung P/V curves were obtained during a PEEP trial in ten patients with acute respiratory failure. The PEEP level where ΔPTP was lowest (optimal PEEP) was determined as the steepest point of the lung P/V curve. Main results. Over-all EL ranged between 7.0–23.2 cmH2O/L. Optimal PEEP was 12.9 cmH2O (10–16) with ΔPTP of 4.1 cmH2O (2.8–7.6). Patients with highest EL were PEEP non-responders, where EL increased in non-dependent and dependent lung at high PEEP, indicating over-distension in all lung. Patients with lower EL were PEEP responders with decreasing EL in dependent lung when increasing PEEP. Significance. PEEP non-responders could be identified by regional lung P/V curves derived from ventilator calibrated EIT. Optimal PEEP could be determined from the equation for the lung P/V curve.
Blob tracking and formation in edge and SOL plasmas using Q-factor
Authors: Bisai N , Sen A
Published: August 2022

We propose a direct means of identifying and tracking plasma blobs in the tokamak edge and scrape-off layer (SOL) regions through evaluation of a quantity Q that is a measure of the relative contribution from the square of the sheared strain and the square of the vorticity at any spatial location. The sheared strain and vorticity are related to the various velocity gradients in the plasma fluid. The blob formation from the breakup of a streamer structure can be determined from the criterion Q > 0. A blob is associated with a high negative value of Q that is indicative of a stable vortex flow of the local fluid trajectories. The validity of this criterion, obtained from a linear eigenvalue analysis of the stability of fluid trajectories, is supported by nonlinear fluid simulations that clearly identify blobs with regions where Q < 0 and exceeds a threshold value. The parameter Q can be experimentally determined from measurements of local electric field shears using gas puff imaging or Langmuir probe techniques, and the proposed criterion can provide a direct means of tracking plasma blobs. The rotation or spin of a blob in the edge and SOL regions can also be characterized by Q.
Applied method of characteristics on 2nd order linear P.D.E
Authors: Farg Ahmed Saeed , Abd Elbary A. M. , Khalil Tarek A.
Published: August 2022

PDEs are very important in dynamics, aerodynamics, elasticity, heat transfer, waves, electromagnetic theory, transmission lines, quantum mechanics, weather forecasting, prediction of crime places, disasters, how universe behave ……. Etc., second order linear PDEs can be classified according to the characteristic equation into 3 types hyperbolic, parabolic and elliptic; Hyperbolic equations have two distinct families of (real) characteristic curves, parabolic equations have a single family of characteristic curves, and the elliptic equations have none. All the three types of equations can be reduced to its first canonical form finding the general solution or the second canonical form similar to 3 basic PDE models; Hyperbolic equations reduce to a form coinciding with the wave equation in the leading terms, the parabolic equations reduce to a form modeled by the heat equation, and the Laplace’s equation models the canonical form of elliptic equations. Thus, the wave, heat and Laplace’s equations serve as basic canonical models for all second order linear PDEs.
Generalized thermoelastic in a fiber-reinforced medium with cylindrical cavity under G-N theory
Authors: Khader S E , Marrouf A A , Khedr M
Published: August 2022

The present paper is aimed at studying the wave propagation for a problem of cylindrical cavity. The material is assumed to be fiber-reinforced with increased stiffness, strength and load bearing capacity. Using generalized thermoelasticity theory, Green and Nagdhi, with and without energy dissipation. Laplace transform techniques are used to derive the solution in the Laplace transform domain. The inversion process is carried out using a numerical method based on Fourier series expansions. The results obtained are displayed by graphs to clear the phenomena physical meaning and compeer with generalized thermoelasticity theories.
Simulation of Ozone Concentrations Inside Co-60 Industrial Irradiator Using UV Optical Cell
Authors: El Gamel Amal , Noaman Ali
Published: August 2022

ozone concentration in the Co-60 industrial irradiator is controlled by the local exhaust ventilation (LEV). if the event of a ventilation malfunction, the ozone concentration becomes increasingly sensible within the radiation chamber. Ozone (O3) is a toxic gas which can cause tract, asthma, and permanent lung damage. its detrimental effects on humans and corrosion of metal parts within the radiation chamber indicates its importance as a safety factor consideration. The motivation for this work designs a standby system to reduce the ozone concentration within the Co-60 industrial radiator. MATLAB was used to simulate the effect of ultraviolet (254 nm) absorption cells on ozone concentration and calculate the decay time. The simulation illustrated that UV absorption is linearly increasing with increasing ozone concentration. Employing a UV Cell proved to reduce ozone concentrations and their decay time with an efficiency of 99%. This may prevent or significantly reduce the discharge of ozone into the air from the workplace. so it’s recommended that’s using UV (254 nm) in the ozone concentration within the Co-60 industrial as it is cheap and efficient controlling substance.
Utilization of INAA Technique for Studying the Negative Impact of Human Activities on Coral Reefs in the Quseir harbour area
Authors: Mohsen Mohamed Y.M. , El-Taher Atef , Shabib Mohamed , Mohamed Nader M. A. , Ashry H. A. , Abdel-Rahman Mohamed A.E.
Published: August 2022

Coral reef samples collected from the Egyptian Red Sea coast’s Quseir harbour were analysed using the INAA technique for qualitative and quantitative analysis. The concentration of heavy metals, rare earth elements, and elemental contents were measured in coral reefs. The samples were assembled with their standards and irradiated in Egypt’s Second Research Reactor at the same time (ETRR-2). The gamma-ray spectra of an HPGe detector with a 100 percent relative efficiency were studied. The elements determined are: Al, Ti, Na, K, Mg, V, Cl, Ca, Mn, Cr, As, Co, Zn, Fe, Br, Tb, Zr, Hf, Sb, Ba, Sc, Nd, La, Sm, Ce, Eu, Yb, Ta, U, and Th. The present work is worried about the use of INAA to attain an accurate knowledge about the elemental content in coral reef samples in the Quseir harbour area and revealing potential environmental indicators for heavy metals contamination as well as pollution hot spot throughout this area to assess the public health for workers, tourists, and the surrounding population.
A desktop study on fish assemblages in Malaysian lotic habitats
Authors: Cheok T N , Soo C L
Published: August 2022

A desktop study on freshwater fish in Malaysian lotic habitats was conducted to provide an overview of the freshwater fish assemblages in Malaysia. Secondary data was extracted from literature that retrieved from major scientific databases including Google Scholar, ScienceDirect, and SpringerLink. A total of 385 fish species from 49 families were documented in Malaysian lotic habitats based on secondary data analysis. The Cyprinidae family is the most abundant fish family in Malaysia with 88 species recorded, followed by Danionidae (44), Bagridae (27), and Osphronemidae (21). The Cyprinidae family has the top five fish species recorded most frequently in Malaysian lotic habitats, which are present in the majority of Malaysia’s states. Approximately 47% of fish species are restricted to just one state of Malaysia, demonstrating endemism of freshwater fish is high in Malaysian lotic habitats. Fish assemblages were found to be similar in Kedah, Kelantan, Pahang, Perak, Terengganu, and Johor, but very different in Sabah, Sarawak, Penang, Negeri Sembilan, and Selangor. Connectivity between lotic habitats in each state, land use, endemism, and invasive species may all influence the fish assemblages in each Malaysian state. This study revealed that ichthyofaunal research is lacking in several Malaysian states. More research should be done in those states to fill in the research gaps and present the most up-to-date information on Malaysia’s ichthyofaunal study.
The SIR Model for COVID-19 in Malaysia
Authors: Zenian S
Published: August 2022

In March 2020, the World Health Organization (WHO) declared COVID-19 as a global pandemic caused by severe acute respiratory syndrome. This virus is referred to as SARS-CoV-2 and the associated disease is COVID-19. It is an infectious disease that can easily be transmitted via respiratory droplets through direct or indirect contact. This paper presents an epidemiological model of COVID-19 in Malaysia by using Susceptible-Infected-Removed (SIR) as a forecasting model. Forecasting is a technique used to predict or estimate the trend or rate of change for future events. This method can provide a good forecasting result for evaluating public health and social measures in response to the COVID-19 epidemic and also to make timely plans.
Pattern Recognition for Ultraviolet and Fourier Transform Data: A Walkthrough of Techniques and Direction
Authors: Hasbi N H , Bade A , Chee F P
Published: August 2022

Pattern recognition has been a thriving field of research in many applications, particularly spectral data classification requiring vast, complex, and high-dimensional data. It aims to extract patterns from data and distinguish the acquired data in order to create a new type of description and pattern. This study walks over pattern identification algorithms for spectral data, namely Ultraviolet (UV) and Fourier Transform Infrared (FTIR) especially within the past five years. In addition, this article will address the present trend analysis, obstacles, and future methods for the pattern identification field of research, with a specific emphasis on UV and FTIR spectroscopic data.