bluuebunny/crossref_metadata_2025 huggingface dataset:
Strain- and thickness-dependent magnetic properties of epitaxial La0.67Sr0.33CoO3/La0.67Sr0.33MnO3 bilayers
Authors: Feng Mingzhen , Ahlm Nolan J. , Kane Alexander M. , Chiu I-Ting , Sasaki Dayne Y. , Shafer Padraic , N'Diaye Alpha T. , Mehta Apurva , Takamura Yayoi
Published: November 2022

Magnetic properties and interfacial phenomena of epitaxial perovskite oxides depend sensitively on parameters such as film thickness and strain state. In this work, epitaxial La0.67Sr0.33CoO3 (LSCO)/La0.67Sr0.33MnO3 (LSMO) bilayers were grown on NdGaO3 (NGO) and LaAlO3 (LAO) substrates with a fixed LSMO thickness of 6 nm, and LSCO thickness (tLSCO) varying from 2 to 10 nm. Soft x-ray magnetic spectroscopy revealed that magnetically active Co2+ ions that strongly coupled to the LSMO layer were observed below a critical tLSCO for bilayers grown on both substrates. On LAO substrates, this critical thickness was 2 nm, above which the formation of Co2+ ions was quickly suppressed leaving only a soft LSCO layer with mixed valence Co3+/Co4+ ions. The magnetic properties of both LSCO and LSMO layers displayed strong tLSCO dependence. This critical tLSCO increased to 4 nm on NGO substrates, and the magnetic properties of only the LSCO layer displayed tLSCO dependence. A non-magnetic layer characterized by Co3+ ions and with a thickness below 2 nm exists at the LSCO/substrate interface for both substrates. The results contribute to the understanding of interfacial exchange spring behavior needed for applications in next generation spintronic and magnetic memory devices.
Cesium intercalation of graphene: A 2D protective layer on alkali antimonide photocathode
Authors: Biswas Jyoti , Gaowei Mengjia , Liu Ao , Poddar Shashi , Stan Liliana , Smedley John , Sadowski Jerzy T. , Tong Xiao
Published: November 2022

Alkali antimonide photocathodes have wide applications in free-electron lasers and electron cooling. The short lifetime of alkali antimonide photocathodes necessitates frequent replacement of the photocathodes during a beam operation. Furthermore, exposure to mediocre vacuum causes loss of photocathode quantum efficiency due to the chemical reaction with residual gas molecules. Theoretical analyses have shown that covering an alkali antimonide photocathode with a monolayer graphene or hexagonal boron nitride protects it in a coarse vacuum environment due to the inhibition of chemical reactions with residual gas molecules. Alkali antimonide photocathodes require an ultra-high vacuum environment, and depositing a monolayer 2D material on it poses a serious challenge. In the present work, we have incorporated a novel method known as intercalation, in which alkali atoms pass through the defects of a graphene thin film to create a photocathode material underneath. Initially, Sb was deposited on a Si substrate, and a monolayer graphene was transferred on top of the Sb film. Heat cleaning around 550–600 °C effectively removed the Sb oxides, leaving metallic Sb underneath the graphene layer. Depositing Cs on top of a monolayer graphene enabled the intercalation process. Atomic force microscopy, Raman spectroscopy, x-ray photoelectron spectroscopy, low energy electron microscopy, and x-ray diffraction measurements were performed to evaluate photocathode formation underneath the monolayer graphene. Our analysis shows that Cs penetrated the graphene and reacted with Sb and formed Cs3Sb.
High performance ultraviolet photodiode based on thin DPPT-TT donor–acceptor organic polymer
Authors: Liang Haoqi , Cui Jiupeng , Yu Zhihao , Sun Huabin , Wei Heming , Zakaria Rozalina , Li Binhong , Wu Jie , Xu Yong , Tan Chee Leong
Published: November 2022

A high-performance ultraviolet photodetector based on a thin layer DPPT-TT organic material is experimentally demonstrated. The high absorption of DPPT-TT in the ultraviolet band is attributed to the foundation for a high-performance ultraviolet detector. The device's responsivity can be improved by adequately designing the hole-blocking layer HfO2 and the stepped structure at the bottom contact. Due to the self-filtering and optical trapping structure, the device achieves external quantum efficiency above 100%, even with a thin absorption layer (around 50 nm). The maximum spectral responsivity of the device is 383 A/W, and the corresponding maximum specific detection rate is about 2.79 × 1012 at a bias voltage of 0.5 V. Our results advocate that the thin organic ultraviolet photodetector promises excellent potential in low-cost ultraviolet-visible light detection and imaging applications.
Antenna-coupled microbolometer based on VO2's non-linear properties across the metal–insulator transition region
Authors: Chen Shangyi , Lust Mark , Ghalichechian Nima
Published: November 2022

This paper presents an antenna-coupled non-linear vanadium dioxide (VO2) microbolometer operating in the non-linear metal–insulator transition (MIT) region with an ultra-high responsivity of 6.55 × 104 V/W. Sputtered VO2 films used in this device exhibit 104 times change in resistivity between the dielectric and conductive states. The VO2 microbolometer is coupled to a wideband dipole antenna operating at 31–55 GHz and a coplanar waveguide for probed measurement. To enhance the sensitivity, the sensor is suspended in air by micro-electro-mechanical systems process. The large thermal coefficient of resistance of VO2 is utilized by DC biasing the device in the MIT region. Measurements for the fabricated sensor were performed, and a high responsivity was demonstrated, owing to non-linear conductivity change in the transition region. The measured sensitivity is >102 times higher than the state-of-the-art sensors. In addition, the concept of utilizing the proposed VO2 sensor in a mmWave imager was demonstrated by the radiation pattern measurement of a 4 × 4 (16 elements) antenna-coupled VO2 sensor array. The results presented in this work reveal the initial step to employ VO2's MIT for a hyper-sensitive sensor in future mmWave sensing and imaging applications.
Explicit analytical form for memory kernel in the generalized Langevin equation for end-to-end vector of Rouse chains
Authors: Tian Xiaofei , Xu Xiaolei , Chen Ye , Chen Jizhong , Xu Wen-Sheng
Published: November 2022

The generalized Langevin equation (GLE) provides an attractive theoretical framework for investigating the dynamics of conformational fluctuations of polymeric systems. While the memory kernel is a central function in the GLE, explicit analytical forms for this function have been challenging to obtain, even for the simple models of polymer dynamics. Here, we achieve an explicit analytical expression for the memory kernel in the GLE for the end-to-end vector of Rouse chains in the overdamped limit. Our derivation takes advantage of the finding that the dynamics of the end-to-end vector of Rouse chains with both free ends are equivalent to those of Rouse chains with one free end and the other fixed. For the latter model, we first show that the equations of motion of the Rouse modes as well as their statistical properties can be obtained under the boundary conditions where the free end is held fixed temporarily. We then analytically solve the terms associated with intrachain interactions in the GLE. By formally comparing these terms with the GLE based on the Rouse modes, we obtain an explicit expression for the memory kernel, along with analytical forms for the potential field and the random colored noise force. Our analytical memory kernel is confirmed by numerical calculations in the Laplace space and is shown to yield asymptotic behaviors that are consistent with previous studies. Finally, we utilize our analytical result to simulate the cyclization dynamics of Rouse chains and discuss the scaling of the cyclization time with chain length.
Disentangling complex current pathways in a metallic Ru/Co bilayer nanostructure using THz spectroscopy
Authors: Beermann Nicolas S. , Fabretti Savio , Rott Karsten , Hafez Hassan A. , Reiss Günter , Turchinovich Dmitry
Published: November 2022

Many modern spintronic technologies, such as spin valves, spin Hall applications, and spintronic THz emitters, are based on electrons crossing buried internal interfaces within metallic nanostructures. However, the complex current pathways within such nanostructures are difficult to disentangle using conventional experimental methods. Here, we measure the conductivity of a technologically relevant Ru/Co bilayer nanostructure in a contact-free fashion using THz time-domain spectroscopy. By applying an effective resistor network to the data, we resolve the complex current pathways within the nanostructure and determine the degree of electronic transparency of the internal interface between the Ru and Co nanolayers.
An efficient implementation of the graphics processing unit-accelerated single-step and simplified lattice Boltzmann method for irregular fluid domains
Authors: Delgado-Gutiérrez Arturo , Marzocca Pier , Cárdenas-Fuentes Diego , Probst Oliver , Montesinos-Castellanos Alejandro
Published: November 2022

In this article, an efficient implementation of the graphics processing unit (GPU)-accelerated single-step and simplified lattice Boltzmann method for curved (irregular) fluid domains (ISSLBM) is presented, allowing the algorithm to predict the macroscopic flow variables in realistic scenarios, such as the wind flow influenced by complex terrains. The fluid domain is approximated and reconstructed with two- and three-dimensional non-uniform rational B-splines functions, allowing customized refinements for desired regions. The model accuracy is investigated by conducting a two-dimensional flow around a circular profile for cases with low Reynolds numbers (Re = 20 and 40). Furthermore, the model is also used to simulate a highly turbulent wind flow (Re = 10 × 106) around the Bolund hill, located in Denmark. Numerical and experimental results reported in the literature are directly compared with the results from the ISSLBM algorithm, producing results with excellent agreement in all metrics. The computational performance is also analyzed, showing that the GPU-accelerated ISSLBM is significantly faster than other simulations reported in the literature.
Basic of Wind Turbine Aerodynamics
Authors: Bangga Galih
Published: November 2022

The energy extracted from a wind turbine rotor depends strongly upon the energy contained in the wind itself as well as how efficient the turbine could extract it. As already presented shortly in Chap. [REF Prev Chapter], blades are a part of the turbine mainly responsible for extracting the energy. In this chapter, the fundamental aerodynamics of the wind turbine blade will be discussed and presented to the readers. In the first part of the chapter, two-dimensional aerodynamic analysis of the blade section is given. This includes the consideration of the viscous and unsteady effects that may occur during wind turbine operation. Furthermore, three-dimensional effects occurring on the flow surrounding the blade near the blade root and tip areas are to be elaborated in this chapter.
Actuator Methods for Wind Turbine Computations
Authors: Bangga Galih
Published: November 2022

This chapter describes the concept of a combined engineering model with computational fluid dynamics (CFD) approaches, namely actuator methods. The discussion is divided into two different branches: (1) the actuator disk method (ADM), which models the rotor as a permeable surface and (2) actuator line method (ALM), which substitutes the blade with a lifting line approach. The general foundations and formulations of both approaches will be discussed, as well as their physical and numerical implications. Recent developments in the fields are highlighted to present the state-of-the-art modeling trends for the ADM and ALM computations.
Validation of an enzyme immunoassay for the non-invasive measurement of faecal androgen metabolites in spinifex hopping mice (Notomys alexis)
Authors: Williams-Kelly Kelly S. , Robert Kylie A. , Palme Rupert , Fanson Kerry V.
Published: November 2022

Androgens may play a key role in shaping the unique reproductive traits of male spinifex hopping mice (Notomys alexis), but little is known about the reproductive endocrinology of this species. Measurement of faecal androgen metabolites (FAMs) offers a non-invasive tool for monitoring testicular activity. Before applying this tool, physiological validation is required to demonstrate that changes in FAMs reflect changes in circulating testosterone for a given species. The goal of this study was to validate an enzyme immunoassay for monitoring FAMs in Notomys alexis. We compared the performance of two different assays (UVM-T and R156/7) for monitoring changes in FAMs following the administration of human chorionic gonadotropin (hCG) to stimulate androgen production by the testes. Both assays detected a significant increase in FAMs and had similar patterns. The UVM-T assay was more sensitive to changes in testicular activity, with a shorter excretion lag time and greater response magnitude. These findings indicate that we can reliably monitor testicular activity using faecal hormone metabolite analysis in Notomys alexis and can now utilise FAM measurements to better understand the species’ unusual reproductive biology.
Improved laboratory method to test flammability metrics of live plants under dynamic conditions and future implications
Authors: Miller Timothy S. , Filkov Alexander I. , Penman Trent D.
Published: November 2022

The role of live vegetation fuel properties in altering fire behaviour is increasingly being recognised. The techniques utilised to assess how fuel characteristics impact fire behaviour, however, use apparatuses that do not accurately represent the exposure of plants to fire. This study presents a replicable and precise laboratory method of testing flammability metrics in live vegetation, particularly Acacia floribunda, Cassinia arcuata and Pinus radiata. Two heating regimes were tested – a static heat flux to reflect current methods and a dynamic (increasing) heat flux to more accurately replicate an approaching fire front. Piloted ignition and autoignition were used for both heating regimes to test the effect of different ignition mechanisms on flammability metrics. The pilot igniter increased the number of samples that reached flaming ignition, and decreased the time and energy required to reach all flammability metrics. Significant differences were observed between heating regimes, suggesting it is important to test flammability of live plants under a dynamic heating regime that most accurately replicates an approaching fire front. Adoption of this methodology is recommended to ensure more realistic and standardised data on flammability of individual plant species and plant communities. This will lead to better-informed and more accurate wildfire behaviour modelling.
Fire propensity in Amazon savannas and rainforest and effects under future climate change
Authors: Santana Mariana Martins Medeiros de , Vasconcelos Rodrigo Nogueira de , Mariano-Neto Eduardo
Published: November 2022

Background Fire dynamics in the Amazon, while not fully understood, are central to designing fire management strategies and providing a baseline for projecting the effects of climate change. Aims The study investigates the recent fire probabilities in the northeastern Amazon and project future ‘fire niches’ under global warming scenarios, allowing the evaluation of drivers and areas of greatest susceptibility. Methods Using the maximum entropy method, we combined a complex set of predictors with fire occurrences detected during 2000–2020. We estimated changes in fire patterns in the near (2020–2040) and distant (2080–2100) future, under two contrasting scenarios of shared socioeconomic pathways. Key results Based on current conditions, the spatial fire pattern is affected by farming activities and fire is more common in savannas than in forests. Over long time scales, changes toward a warmer and drier climate, independent of land cover change, are expected to create conditions more conducive to burning. Conclusion and implications Our study helps in understanding the multiple ecological and human interactions that result in different fire regimes in the Amazon. Future efforts can improve outcomes through more complex models that couple predictions of land use and land cover changes, shifts in vegetation resulting from climate change and fires, and fuel dynamics.
Resistance of young working-class women in Swiss activation labour market programmes
Authors: Nada Eva
Published: November 2022

Recent studies on active labour-market programmes have shown that welfare beneficiaries exercise agency to resist normative expectations and institutional demands leading to low-paid jobs. This study examines young native and immigrant working-class women’s resistance to labour-market activation policies in French-speaking Switzerland. Using ethnographic data from two activation programmes and interviews with young unemployed women, the results show that the gendered organisation of the programmes contributes to making women and their work invisible. The young native women use their invisibility strategically to develop discreet resistance and fight for their respectability. Immigrant women are more compliant but exercise forms of political agency for emancipation. Using the approach of particularistic resistance, we show that resistance within welfare institutions is not only a way to express individual dissatisfaction but also a form of agency and individual political action. Future studies should examine welfare beneficiaries’ agency in navigating and resisting welfare policies.
SARS-CoV-2 Spike protein suppresses CTL-mediated killing by inhibiting immune synapse assembly
Authors: Onnis Anna , Andreano Emanuele , Cassioli Chiara , Finetti Francesca , Della Bella Chiara , Staufer Oskar , Pantano Elisa , Abbiento Valentina , Marotta Giuseppe , D’Elios Mario Milco , Rappuoli Rino , Baldari Cosima T.
Published: November 2022

CTL-mediated killing of virally infected or malignant cells is orchestrated at the immune synapse (IS). We hypothesized that SARS-CoV-2 may target lytic IS assembly to escape elimination. We show that human CD8+ T cells upregulate the expression of ACE2, the Spike receptor, during differentiation to CTLs. CTL preincubation with the Wuhan or Omicron Spike variants inhibits IS assembly and function, as shown by defective synaptic accumulation of TCRs and tyrosine phosphoproteins as well as defective centrosome and lytic granule polarization to the IS, resulting in impaired target cell killing and cytokine production. These defects were reversed by anti-Spike antibodies interfering with ACE2 binding and reproduced by ACE2 engagement by angiotensin II or anti-ACE2 antibodies, but not by the ACE2 product Ang (1-7). IS defects were also observed ex vivo in CTLs from COVID-19 patients. These results highlight a new strategy of immune evasion by SARS-CoV-2 based on the Spike-dependent, ACE2-mediated targeting of the lytic IS to prevent elimination of infected cells.
Final report on GULFMET supplementary comparison of high current transformer measuring systems (GULFMET.EM-S7)
Authors: Velychko O , Kikalo V , Cayci H , Ayhan B , Qoud Saad Bin
Published: November 2022

Main text

A comparison of high current transformer measuring systems between SE "Ukrmetrteststandard" (Ukraine), TÜBİTAK (Turkey) and NMCC SASO (Saudi Arabia), conducted between December 2020 and December 2021. Current transformer СА535/2 is used as the traveling standard and SE "Ukrmetrteststandard" acted as the pilot laboratory. Measurements were performed at a current from 5 A to 4000 A at frequencies 50 Hz and 60 Hz.

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.

The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Theory of Critical Phenomena with Memory
Authors: Zeng Shaolong , Szeto Sue Ping , Zhong Fan
Published: November 2022

Memory is a ubiquitous characteristic of complex systems, and critical phenomena are one of the most intriguing phenomena in nature. Here, we propose an Ising model with memory, develop a corresponding theory of critical phenomena with memory for complex systems, and discover a series of surprising novel results. We show that a naive theory of a usual Hamiltonian with a direct inclusion of a power-law decaying long-range temporal interaction violates radically a hyperscaling law for all spatial dimensions even at and below the upper critical dimension. This entails both indispensable consideration of the Hamiltonian for dynamics, rather than the usual practice of just focusing on the corresponding dynamic Lagrangian alone, and transformations that result in a correct theory in which space and time are inextricably interwoven, leading to an effective spatial dimension that repairs the hyperscaling law. The theory gives rise to a set of novel mean-field critical exponents, which are different from the usual Landau ones, as well as new universality classes. These exponents are verified by numerical simulations of the Ising model with memory in two and three spatial dimensions.
Influence of discharge polarity on streamer breakdown criterion of ambient air in a non-uniform electric field
Authors: Iqbal Asif , Wozniak Daniel , Rahman Md Ziaur , Banerjee Sneha , Verboncoeur John , Zhang Peng , Jiang Chunqi
Published: November 2022

Streamer breakdown of atmospheric air with non-uniform dc electric field in a needle-to-plate electrode configuration is studied using a semi-analytic model and experimental measurements. A high voltage (either positive or negative) is applied to a hollow needle with

0.51

mm

outer diameter and

0.25

mm

inner diameter separated from a planar ground electrode by a gap distance of 0.1–1.4 cm. Breakdown voltages are recorded for both positive and negative discharge polarities. Empirical relations between the critical avalanche size for streamer breakdown and the gap distance are proposed. Using these empirical relations, a semi-analytic model based on Meek’s criterion for streamer breakdown is developed to accurately predict the measured breakdown voltages. It is found that for

p
d
>
380

 Torr 

cm

(or d

>

0.5 cm at one atmosphere) streamer breakdown of ambient air occurs at a lower applied voltage for a positively biased needle compared to that with a negatively biased needle, referred as the polarity effect. For

p
d
<
380

 Torr 

cm

breakdown is attained at a lower applied voltage with a negatively biased needle compared to that with a positively biased needle, and breakdown mode transits from the polarity effect to the so called inverted polarity effect.
Scanning x-ray excited optical luminescence of heterogeneity in halide perovskite alloys
Authors: Dolan Connor J , Cakan Deniz N , Kumar Rishi E , Kodur Moses , Palmer Jack R , Luo Yanqi , Lai Barry , Fenning David P
Published: November 2022

Understanding the optoelectronic properties of optically active materials at the nanoscale often proves challenging due to the diffraction-limited resolution of visible light probes and the dose sensitivity of many optically active materials to high-energy electron probes. In this study, we demonstrate correlative synchrotron-based scanning x-ray excited optical luminescence (XEOL) and x-ray fluorescence (XRF) to simultaneously probe local composition and optoelectronic properties of halide perovskite thin films of interest for photovoltaic and optoelectronic devices. We find that perovskite XEOL stability, emission redshifting, and peak broadening under hard x-ray irradiation correlates with trends seen in photoluminescence measurements under continuous visible light laser irradiation. The XEOL stability is sufficient under the intense x-ray probe irradiation to permit proof-of-concept correlative mapping. Typical synchrotron XRF and nano-diffraction measurements use acquisition times 10–100x shorter than the 5-second acquisition employed for XEOL scans in this study, suggesting that improving luminescence detection should allow correlative XEOL measurements to be performed successfully with minimal material degradation. Analysis of the XEOL emission from the quartz substrate beneath the perovskite reveals its promise for use as a real-time in-situ x-ray dosimeter, which could provide quantitative metrics for future optimization of XEOL data collection for perovskites and other beam-sensitive materials. Overall, the data suggest that XEOL represents a promising route towards improved resolution in the characterization of nanoscale heterogeneities and defects in optically active materials that may be implemented into x-ray nanoprobes to complement existing x-ray modalities.
Theoretical study on the electronic properties of different types of the donor:acceptor complexes
Authors: Wang Lilong , Wang Haiyan , Li Junhui , Zhang Haitao
Published: November 2022

Non-fullerene organic solar cells can be classified into four forms in line with the different types of donor (D) and acceptor (A) in the active layer: all-polymer (PD:PA), polymer D:small-molecule A (PD:MA), small-molecule D:polymer A (MD:PA), and all-small-molecule (MD:MA). On the basis of having studied the electronic properties of a large number of related monomer molecules and D:A complexes, this work constructed four groups of D:A molecular pairs as described above as examples to investigate their electronic properties with first-principles density functional theory. The results show that the absolute value of the average binding energy of the PD:PA complex D18:P(NDI2HD-T) is larger than others, indicating the structure is relatively more stable. In accordance of the Bader charge analysis, the intra-molecular charge transfer of small-molecule is greater than polymers. For these blends, the intermolecular charge transfer of the all-polymer pair D18:P(NDI2HD-T) is larger, revealing that the PD:PA pair may result in a stronger intermolecular dipole electric field, which is beneficial to facilitate the separation of excitons. In addition, the MD:MA pair DRTB-T:FDICTF-2Cl and the PD:MA complex D18:FDICTF-2Cl all exhibit a larger amount of intra-molecular charge transfer, which indicates that the small-molecule acceptors in D:A complexes are conducive to promoting intra-molecular charge transfer.
GSCV-XGBoost based information reconstruction and fusion method for SINS/DVL integrated navigation system
Authors: Qin Hongmao , Wang Ying , Wang Guangcai , Qin Xiaohui , Bian Yougang
Published: November 2022

An underwater navigation system has specific requirements for reliability. In the frequently used strapdown inertial navigation system/Doppler velocity log (SINS/DVL) integrated navigation system, the process of the DVL measuring velocity is always disturbed in a complex underwater environment. Thus the velocity measurements on acoustic beam directions are prone to get lost, which seriously affects system reliability. This paper proposes a novel information reconstruction and integration algorithm to solve this problem, based on the tree boosting model. The algorithm is mainly divided into two consecutive stages: training and reconstruction. When the DVL velocity in all beam directions is available, the GSCV-XGBoost (extreme gradient boosting based on the grid-search and cross-validation theory) method is used to train the mapping model between DVL velocity and SINS/DVL integrated navigation system velocity. When the DVL velocity is incompletely available, the mapping model, that has been trained in advance, is used to reconstruct the missing DVL velocity measurements and resume normal SINS/DVL integration conditions. Simulation and underwater vehicle-mounted experiments are applied to verify that the proposed algorithm reconstructs more accurate velocity information than traditional XGBoost, which shows great prospects for application and reliability in the SINS/DVL underwater integrated navigation system.
A novel motor fault diagnosis method based on principal component analysis (PCA) with a discrete belief rule base (DBRB) system
Authors: Yu Hang , Gao Haibo , He Yelan , Lin Zhiguo , Xu Xiaobin
Published: November 2022

Motor vibration signal data sets are characteristically random and nonlinear, and its features are difficult to extract for fault identification. To reduce the uncertainty of fault diagnosis, a method based on principal component analysis (PCA) and discrete belief rule base (DBRB) was developed for the first time. Initially, the vibration signal was first denoised using a wavelet threshold algorithm to eliminate interference. Second, overlapping signals were segmented into 15 time windows and a total of 13 typical time domain features and mathematical statistical features were extracted. Third, the dimensions of the features were reduced to three principal components by PCA and were taken as the antecedent attributes of the DBRB. However, the amount of information in each principal component is different, so the variance contribution rate was taken as an antecedent attribute weight to restore the original data characteristics. Fourth, a PCA-DBRB model was established, which effectively avoided the combinatorial explosion problem of rule base in the DBRB model. In addition, to obtain appropriate reference values, the k-means algorithm was introduced to take the cluster centers as reference values. The method was then validated by collecting typical fault data from motor bench experiments. The results demonstrated that compared with other traditional classifiers, this approach is more effective and superior in classification performance and more accurate in diagnosing faults from motor vibration data.
Multi-physics modeling of grain growth during solidification in electron beam additive manufacturing of Inconel 718
Authors: Kamat Shardul , Li Xuxiao , Stump Benjamin , Plotkowski Alex , Tan Wenda
Published: November 2022

While experimental work has shown promising results regarding control of additive manufacturing metal grain structure, the effects of processing parameters on the grain structure is difficult to understand and predict from experiment alone. To this end, a modeling framework is developed which sequentially couples a macro-scale, semi-analytic thermal model, and a meso-scale, cellular automata-based microstructure model. This framework is applied to electron beam additive manufacturing of Inconel 718 using a complex spot scan pattern. The model shows that, with the same scan pattern, variations in the spot time and electron-beam current produce thermal histories with significant spatial and temporal differences, which then produce complex solidification conditions from the interplay between molten pools in the same layer and subsequent layers, resulting in vastly different grain structures. It is noted that the framework can significantly reduce the computational expenses for coupled thermal-metallurgical problems, and has the potential to be used for component level problems.
Plasmonic optical fiber gratings based on few-layer Ta2C MXenes for refractive index sensing
Authors: Liu Runcheng , Yang Wen , Lu Jiajun , Shafi Muhammad , Jiang Mingshun , Jiang Shouzhen
Published: November 2022

Tilted fiber Bragg grating (TFBG) is a widespread approach for developing refractive index (RI) sensors. The unique optoelectronic properties exhibited by MXene are expected to enhance the performance of TFBG-SPR sensors. In this study, a Ta2C coating appropriate for sensing was obtained by optimizing the photo-deposition time, which addressed the challenge of preparing large areas of MXene. The uniform coating of the few-layer Ta2C increases the wavelength sensitivity and FOM of the sensor to 229.5 nm/RIU and 2228.15 respectively. This significant enhancement was attributed to an ordered MXene phase of the grown Ta2C. The energy band theory verified the metallic nature of the Ta2C and the amplification effect on the RI response. Finite element analysis demonstrated that the stronger absorption band of Ta2C facilitated the generation of surface plasmon polariton. Based on the above benefits, the sensor detected melamine in milk with a detection limit of 7.9 × 10−9 M. The TFBG/Au/Ta2C sensor is a promising approach for biochemical analysis and trace detection.
Porous unsupported CuO nanoplates for efficient photothermal CO oxidation
Authors: Liang Rong , Chen Xuehua , Qin Chao , Ye Zhizhen , Zhu Liping , Lou Zirui
Published: November 2022

It is a significant issue for environmental protection and industrial production to eliminate CO, a gas harmful to life and some important reaction sites. Real environmental conditions require catalytic CO oxidation to occur at relatively low temperature. Nowadays, photothermal catalysis has been exploited as a new way to achieve CO elimination, different from thermal catalysis. CuO, as cheap and abundant substitute for precious metals, is considered to have potential in photothermal catalysis. Oxygen vacancies (OV) and lattice oxygen (OL) activity are considered extremely crucial for oxide catalysts in CO oxidation, according to Mars−van Krevelen mechanism. Herein, porous CuO nanoplates with adjustable OV and OL activity were prepared by a facile method via controlling the morphology and phase composition of precursors. The light-off temperature (50% conversion) of the best sample obtained under the optimal conditions was ∼110 °C and an almost complete conversion was reached at ∼150 °C. It also achieved nearly 70% conversion under 6 standard Suns (6 kW cm−2 irradiation) and could work in infrared radiation (IR) regions, which could be attributed to the photo-induced thermal effect and activation effect. The simple synthesis and characterization provide a good example for the future photothermal catalysis.
Improvement of proton beam range uncertainty in breast treatment using tissue samples
Authors: Cui Xiangli , Jee Kyungwook , Hu Man , Bao Jie , Lu Hsiao-Ming
Published: November 2022

Objective. Proton therapy after breast-conserving surgery (BCS) can substantially reduce the dose to lung and cardiac structures. However, these dosimetric benefits are subject to beam range uncertainty in patient. The conversion of the CT-Hounsfield unit (HU) into relative stopping power (RSP) is the primary contribution to range uncertainty. Hence, an accurate HU-RSP conversion is essential. Approach. Real tissue samples, including muscle and adipose, were prepared. The water equivalent path length (WEPL) of these samples was measured under homogeneous conditions using a 12-diode detector array of our time-resolved in vivo range verification system (IRVS). The HU-RSP conversion was improved using the measured WEPL and HU for adipose tissue. The measured WEPL values were compared with the treatment planning calculation results based on the stoichiometric CT-HU calibration technique. The effect was investigated for both with and without adipose tissue in HU-RSP conversion. Main results. The IRVS was calibrated based on the solid water phantom. The relative differences in WEPL (RSP) between measurements and calculations for muscle, adipose, and water was −1.19% (−0.75%), −4.25%(−4%), and −0.23%(−0.07%), respectively. Based on the improved HU-RSP conversion, the relative differences in WEPL was reduced to −0.97%(−0.62%), −1.50%(−1.46%), and −0.22% (0.00%), respectively. Significance. The WEPL deviation of adipose tissue is larger than the testing limit of 3.5% for beam range robustness in current clinical practice. However, the improved HU-RSP conversion reduced this deviation. The main component of breast tissue is adipose. Hence, the proton treatment of BCS can be undershooting if no proper measures are taken against this specific uncertainty.
Tunable broad-band absorber consisted of crossed-oval shape of graphene
Authors: Bagheri Mohammad Kazem , Hosseini Mehdi , Bahadoran Mahdi
Published: November 2022

A three-dimensional broadband absorber structure was proposed based on the crossed-oval shape of graphene (COSG) on a wafer layout. This structure consisted of silicon/gold/silica wafer and a superstrate layer of graphene patterns in the form of crossed-oval placed on top of the wafer. The effect of geometrical parameters on the absorption was studied. Results show that this structure can absorb over 99% of the incoming light over a broad range of THz frequencies. The absorption peaks were fine-tuned by changing the geometrical and physical parameters. This property is vital and desirable in optical detectors, chemical sensors, and other optical devices.
Effect of anisotropic grain boundaries on the surface blistering of tungsten induced by deuterium plasma exposure
Authors: Xia Tongjun , Jiang Zhenyu , Shi Yongzhi , Ren Xinyu , Zhu Kaigui
Published: November 2022

The effect of anisotropic grain boundaries on the surface microstructure changes and deuterium retention behavior in tungsten under deuterium plasma irradiation were studied. The samples named as NDW and RDW were cut from RD × TD plane and TD × ND plane of a rolled W plate (ND: normal direction, RD: rolling direction, TD: transverse direction), respectively. The results suggest that both surface morphology and deuterium retention in the RDW samples are suppressed compared to that of NDW samples for 1 h and 25 h deuterium irradiation. For 1 h exposure, the total deuterium retention in the NDW samples is about 1.6 times as much as that of RDW. However, as the exposure time increased to 25 h, the total deuterium retention in the NDW sample is two times the height of RDW sample. The experimental results show that the special grain structure of RDW can alleviate the surface morphology changes and decrease the deuterium retention in tungsten, which is interpreted by the lateral stress model of blistering.
Fano resonance characteristics of a silicon notched disk metasurface-waveguide system under different polarization conditions
Authors: Chen Ying , Li Meijie , Zhang Min , Ding Zhixin
Published: November 2022

In this paper, we design and theoretically investigate a silicon notched disk metasurface-waveguide (NDMW) system, realizing a new approach to excite Fano resonance by introducing a waveguide layer to generate quasi-guided mode (QGMs) resonances. By comparing the transmission characteristics of the silicon complete disk metasurface (CDM), the silicon complete disk metasurface-waveguide (CDMW) system, and the NDMW system, the formation mechanism of Fano resonances in multiple different excitation modes is analyzed. Furthermore, the Fano resonance characteristics of the NDMW system for different polarization conditions are studied. It can be found that different polarization states can excite different multiple Fano resonances in the NDMW system. Finally, the effects of various structural parameters on the multiple Fano resonances characteristics are investigated. Utilizing the narrow linewidth and significant near-field confinement of the Fano resonances, an optical refractive index sensor can be obtained with the sensitivity of 113 nm RIU−1 and the maximum quality (Q) factor of

2
×

10

5

.

The proposed system opens up an avenue to develop high-performance biological sensors.
Chaotic dynamics in tritrophic interaction with volatile compounds in plants with power law kernel
Authors: Sami Adnan , Saifullah Sayed , Ali Amir , Rahman Mati ur
Published: November 2022

In this article, we study a fractional-order mathematical model representing tritrophic interaction amongst plants, herbivores, and carnivores with Caputo derivative. The existence and uniqueness of the system are investigated by fixed point theory, while the stability is studied by Hyers-Ulam and generalized Hyers-Ulam stability analysis. The Adams-Bashforth-Moulton scheme is used for numerical calculations. From numerical simulations, it is observed that when the fractional order decreases the system converges to a stable state. It is observed that for a small value of fractional order, the system approaches a stable state rapidly as compared to the integer order. The chaotic behaviour of the system is studied using the Lyapunov spectrum. It is noted that two positive exponents of the proposed model show that the system is hyper-chaotic. It is also observed that a small value of attraction constant disrupts the system due to volatile organic compounds.
On the barocaloric properties of non-magnetic materials: application to K
2
TaF
7 and AgI
Authors: de Oliveira N A
Published: November 2022

In this paper, we theoretically discuss the effect of thermal expansion on the entropy change and the barocaloric properties of non-magnetic materials. For this purpose, we use a microscopic model Hamiltonian that takes into account the lattice vibrations beyond the harmonic approximation. The model was applied to calculate the entropy change and the barocaloric quantities ΔS

iso
and ΔT

ad
in the compounds K
2
TaF
7 and AgI.
DeWitt wave function in Hořava-Lifshitz cosmology with tensor perturbation
Authors: Martens Paul , Matsui Hiroki , Mukohyama Shinji
Published: November 2022

We present a well-tempered DeWitt wave function, which vanishes at the classical big-bang singularity, in Hořava-Lifshitz (HL) cosmology with tensor perturbation, both analytically and numerically. In general relativity, the DeWitt wave function is ill-behaved once the tensor perturbation is taken into account. This is essential because the amplitude of the perturbation diverges at the singularity and the perturbative expansion completely breaks down. On the other hand, in HL gravity it is known that the higher dimensional operators required by the perturbative renormalizability render the tensor perturbation scale-invariant and regular all the way up to the singularity. In this paper we analytically show that in d+1 dimensional HL gravity, the DeWitt wave function for tensor perturbation is indeed well-defined around the classical big-bang singularity. Also, we numerically demonstrate the well-behaved DeWitt wave function for tensor perturbation from the singularity to the finite size of the Universe.
MUPHOTEN: A MUlti-band PHOtometry Tool for TElescope Network
Authors: Duverne P. A. , Antier S. , Basa S. , Corre D. , Coughlin M. W. , Filippenko A. V. , Klotz A. , Hello P. , Zheng W.
Published: November 2022

The early and complete temporal characterization of optical, fast, transient sources requires continuous and multiband observations over different timescales (hours to months). For time-domain astronomy, using several telescopes to analyze single objects is the usual method, allowing the acquisition of highly sampled light curves. Taking a series of images each night helps to construct an uninterrupted chain of observations with a high cadence and low duty cycle. Speed is paramount, especially at early times, in order to capture early features in the light curve that help determine the nature of the observed transients and assess their astrophysical properties. However, the problem of rapidly extracting source properties (temporal and color evolution) with a heterogeneous data set remains. Consequently, we present Muphoten, a general and fast-computation photometric pipeline able to address these constraints. It is suitable for extracting transient brightness over multitelescope and multiband networks to create a single homogeneous photometric time series. We show the performance of Muphoten with observations of the optical transient SN 2018cow (from 2018 June to 2018 July), monitored by the GRANDMA network and with the publicly available data of the Liverpool Telescope.
On the correlation of angular distributions of keV ions and trajectory-dependent electronic excitations in transmission channelling geometry
Authors: Holeňák R , Lohmann S , Komander K , Primetzhofer D
Published: November 2022

We use energy discrimination of keV ions transmitted through a thin, single-crystalline silicon membrane to correlate specific angular distribution patterns formed in channelling geometry with trajectory-dependent electronic energy loss. The integral energy and intensity distribution of transmitted ions can thus be dissected into on one side axially channelled projectiles travelling along rather straight trajectories and on the other side dechannelled projectiles predominantly experiencing blocking. Angular distributions of transmitted ions are further simulated with two different Monte-Carlo codes.
Edge dislocations in Ni monocrystalline structure studied by McChasy 2.0 Monte Carlo code
Authors: Mieszczynski Cyprian , Nowicki Lech , Skrobas Kazimierz , Jozwik Przemyslaw , Jagielski Jacek
Published: November 2022

The main goal of the McChasy code, in general, is to reproduce Rutherford Backscattering Spectrometry experimental spectra recorded in channeling direction (RBS/C) by simulating He-ions travelling inside crystalline structures and to calculate the probability of the backscattering process. The 2.0 version of the code provides the possibility to simulate channeling spectra in large (ca. 108 atoms) arbitrary structures that are created based on crystallographic data or Molecular Dynamic (MD) calculations.

In this work, we present the current status of the code and the results of recent investigations of extended structural defects (edge dislocations and dislocation loops) formed inside nickel (Ni) single crystals. Two ways of modelling extended defects are described: one developed using the McChasy code (Peierls-Nabarro approach) and the other one obtained by modification and thermalization of Ni structures by MD (LAMMPS code). The atomic local environment was studied qualitatively and quantitatively by the local projectile-flux density distributions around the defects.
Copper-based surface plasmon coupled emission steering for biosensor applications
Authors: Vijayan Ajeesh P , Sreelakshmi A. , Sharin Fasna , Kannan Pradeesh
Published: November 2022

Surface plasmon coupled emission (PCE) was demonstrated using Copper (Cu) as metal film and Rhodamine B (RhB) dye doped Poly Vinyl Alcohol (PVA) as dielectric layer coupled to a hemicylindrical prism in Reverse Kretschmann (RK) configuration. Emission directionality was observed due to PCE and the dielectric layer thicknesses highly influence PCE emission steering. A correlation of emission directionality and the dielectric layer thickness was achieved. For dielectric with higher thicknesses, PCE tuning was also observed apart from emission steering. Emission steering and a promising PCE tuning in Cu could pave the way for a cost effective PCE based bio-chemical sensor.
Power dependent nonlinear optical characteristics and two-photon absorption of NiO/PVA thin film
Authors: Kumar V Pradeep , Pradeep C , Radhakrishnan P , Mujeeb A
Published: November 2022

The NiO/PVA thin film was prepared by drop-casting the nickel oxide nanoparticles synthesized by the chemical precipitation method. The structural and optical characteristics of the film were investigated using XRD and UV-VIS absorption. The nonlinear optical property of the Nickel oxide thin film was studied by the open aperture Z-scan method at 532 nm. The two-photon absorption coefficient of the film was calculated with different optical intensities. With increasing input intensity, the value of the two-photon absorption coefficient has decreased. This is attributed to the saturation of two-photon absorption mechanism. The NiO/PVA film can be used for optical limiting applications.
Effects of Initial Phase on Silicon Nanoparticles Formation in Femtosecond Laser Ablation
Authors: Kumar Kanaka Ravi , Chandu B. , Bharati M.S.S. , Rao M. Mallikarjuna , Rao S. Venugopal , Rao S.V.S. Nageswara
Published: November 2022

We report on the ultrafast (femtosecond) laser ablation of monocrystalline Si (100), polycrystalline Si, and Si (100) capped with a SiO2 layer. The target material was ablated using femtosecond laser pulses (~50 fs duration, 1 kHz repetition rate, and 800 nm wavelength) with an input energy of ~100 μJ in acetone medium to fabricate Si Nanoparticles (NPs). The average size of NPs produced by Si (100) was found to be less than that of the particles produced by poly Si. Ablation of Si caped with SiO2 resulted in bigger Si NPs together with a low concentration of SiO2 NPs. NPs were found to be of polycrystalline in all three cases irrespective of the initial phase.