bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal-flow characteristics analysis of a novel resilient capacity ceramic insulated winding dry type transformer
Authors: Li Haomin , Zhang Qirui , Lei Li , Geng Yingsan , Wang Jianhua
Published: April 2024

With the increasing demand for the resilient capacity of transformers in high-proportion renewable energy grids, the overload capacity of transformers and the thermal conductivity of winding insulation materials have been put forward as important requirements. In response to these requirements, a novel ceramic high temperature tolerance insulation winding is proposed in this paper and is applied in a ceramic insulated winding transformer. A combination of simulation and experimentation is used to analyze the thermal-flow characteristics of this transformer. The temperature and flow field distribution characteristics of transformers with both winding insulation methods (ceramic and Nomex paper) are compared. The internal mechanism of reflux near the iron core and high voltage winding under forced air cooling is clarified. A superior outside cooling condition is obtained. A prototype ceramic insulated winding transformer is developed and tested to verify the accuracy of the simulation model. The results show that the hotspot temperature of the ceramic insulated winding transformer under natural cooling is 10.7% lower than that of the Nomex paper insulated winding transformer. With forced air cooling of 2, 3, 4, 5, and 6 m/s applied at the bottom, the hotspot temperature of the ceramic insulated winding transformer is 11.4%, 10.5%, 9.7%, 14.0%, and 17.8% lower than that of the Nomex paper insulation winding transformer, respectively. Under forced air cooling, a reflux phenomenon is observed in both transformers in the vicinity of the iron core and high voltage winding due to the formation of adverse pressure gradient region and wall viscous force blocking. The strength of the reflux is affected by the magnitude of the forced air cooling flow velocity and the construction of the transformer. The optimal range of the external cooling flow velocity for the ceramic insulated winding transformer is 3–4 m/s. The errors between the simulated temperature and the measured temperature at the nine monitoring points of the prototype are all less than 5%, which verifies the effectiveness of the simulation model. The experimental and theoretical basis for the design and application of resilient capacity dry type transformers is provided by this research.
Dynamics of multi-mode nonlinear internal waves in fluids of great depth
Authors: Wang Zi'an , Hu Ganghua , Wang Zhan
Published: April 2024

This paper is mainly concerned with the dynamics of strongly nonlinear internal waves in two-dimensional fluids of great depth. A fully nonlinear model for a three-layer fluid of great depth containing topography, a Miyata–Choi–Camassa (MCC)-type system, is developed based on the generalization of the Ablowitz–Fokas–Musslimani global-relation formulation for free-surface water waves. Mode-1 internal solitary waves are numerically found in the MCC-type equation using the Petviashvili iteration technique and in the full Euler equations based on the boundary integral equation method. The comparison between the results validates the broad applicability of the MCC-type system. Mode-2 internal solitary waves are found in the MCC-type equations and are shown to be a type of gap solitary wave. Using the multi-mode internal solitary-wave solutions in the MCC-type equations, we apply the conformal mapping technique to calculate streamlines and particle trajectories. For unsteady simulations, we propose a pseudo-spectral algorithm to handle the time-coupled equations and investigate the generation mechanism of multi-mode internal solitary waves due to the resonance effect of local protrusion on the rigid wall, as well as their collisions when the wall is flat. For flows past protrusion on the rigid wall, the flow speed can be divided into subcritical, transcritical, and supercritical. The shedding of multi-mode internal solitary waves can occur only in the transcritical region of flow speed. We implement the carving of bifurcation curves with inflection to achieve the regional delimitation and, based on this, the interpretation of the generation mechanism from a physical point of view.
Shoving model and the glass transition in one-component plasma
Authors: Khrapak S. A.
Published: April 2024

A modified shoving model is applied to estimate the location of the glass transition in a one-component plasma. The estimated value of the coupling parameter Γ ≃ 570 at the glass transition is compared with other predictions available in the literature.
New center for quantum sensing focuses on medical applications
Authors: Feder Toni
Published: April 2024

The techniques promise earlier disease detection that can lead to better outcomes.
Overexpression of TaMPK3 enhances freezing tolerance by increasing the expression of ICE-CBF-COR related genes in the Arabidopsis thaliana
Authors: Wang Rui , Yu Mengmeng , Zhao Xin , Xia Jingqiu , Cang Jing , Zhang Da
Published: April 2024

Mitogen-activated protein kinases (MAPKs) play important roles in plant stress response. As a major member of the MAPK family, MPK3 has been reported to participate in the regulation of chilling stress. However, the regulatory function of wheat (Triticum aestivum) mitogen-activated protein kinase TaMPK3 in freezing tolerance remains unknown. Dongnongdongmai No.1 (Dn1) is a winter wheat variety with strong freezing tolerance; therefore, it is important to explore the mechanisms underlying this tolerance. In this study, the expression of TaMPK3 in Dn1 was detected under low temperature and hormone treatment. Gene cloning, bioinformatics and subcellular localisation analyses of TaMPK3 in Dn1 were performed. Overexpressed TaMPK3 in Arabidopsis thaliana was obtained, and freezing tolerance phenotype observations, physiological indices and expression levels of ICE-C-repeat binding factor (CBF)-COR-related genes were determined. In addition, the interaction between TaMPK3 and TaICE41 proteins was detected. We found that TaMPK3 expression responds to low temperatures and hormones, and the TaMPK3 protein is localised in the cytoplasm and nucleus. Overexpression of TaMPK3 in Arabidopsis significantly improves freezing tolerance. TaMPK3 interacts with the TaICE41 protein. In conclusion, TaMPK3 is involved in regulating the ICE-CBF-COR cold resistance module through its interaction with TaICE41, thereby improving freezing tolerance in Dn1 wheat.
Physiological responses of the microalgae Thalassiosira weissflogii to the presence of the herbicide glyphosate in the medium
Authors: Solomonova Ekaterina , Shoman Natalia , Akimov Arkady
Published: April 2024

We evaluated changes in growth, chlorophyll fluorescence and basic physiological and biochemical parameters of the microalgae Thalassiosira weissflogii cells under the influence of the herbicide glyphosate in concentrations 0, 25, 95 and 150 μg L−1. The toxic effect of glyphosate on algae is weakly dependent on the level of cell mineral nutrition. High concentrations of the herbicide do not lead to the death of microalgae but block the process of algae cell division. An increase in the glyphosate concentration in the medium leads to a slowdown or stop of algal growth, a decrease in their final biomass, an increase in the production of reactive oxygen species (ROS), depolarisation of mitochondrial membranes and metabolic activity of algae. Glyphosate inhibits the photosynthetic activity of cells and inhibits the relative rate of electron transport in the photosynthetic apparatus. Glyphosate at the studied concentrations does not affect the size characteristics of cells and the intracellular content of chlorophyll in T. weissflogii. The studied herbicide or products of its decay retain their toxic properties in the environment for at least 9 days. This result shows the need for further in-depth studies to assess the physiological response and possible acclimation changes in the functional state of oxygenic phototrophs in response to the herbicide action. The species specificity of microalgae to the effects of glyphosate in natural conditions is potentially dangerous due to a possible change in the species structure of biocoenoses, in particular, a decrease in the contribution of diatoms.
Negotiating discord in sustainability transformations
Authors: Patterson James J. , Feola Giuseppe , Kim Rakhyun E.
Published: April 2024

Policy action for sustainability transformation faces inherent and ever-present sources of conflict, pushback, and resistance (i.e., discord). However, conceptual frameworks and policy prescriptions for sustainability transformations often reflect an undue image of accord. This involves simplified assumptions about consensus, steering, friction, discreteness, and additiveness of policy action, conferring an unrealistic view of the potential to deliberately realize transformation. Instead, negotiating discord through continuously finding partial political settlements among divided actors needs to become a key focus of policy action for sustainability transformations. Doing so can help to navigate deeply political settings through imperfect but workable steps that loosen deadlock, generate momentum for further policy action, and avoid complete derailment of transformation agendas when discord arises.
Enriching surface-ordered defects on WO
3
for photocatalytic CO
2
-to-CH
4
conversion by water
Authors: Xue Sikang , Wei Changgeng , Shen Min , Liang Xiaocong , Wang Jiali , Yang Can , Xing Wandong , Wang Sibo , Lin Wei , Yu Zhiyang , Hou Yidong , Yu Jimmy C. , Wang Xinchen
Published: April 2024

Defect engineering has been widely applied in semiconductors to improve photocatalytic properties by altering the surface structures. This study is about the transformation of inactive WO
3
nanosheets to a highly effective CO
2
-to-CH
4
conversion photocatalyst by introducing surface-ordered defects in abundance. The nonstoichiometric WO

3-
x

samples were examined by using aberration-corrected electron microscopy. Results unveil abundant surface-ordered terminations derived from the periodic {013} stacking faults with a defect density of 20.2%. The {002} surface-ordered line defects are the active sites for fixation CO
2
, transforming the inactive WO
3
nanosheets into a highly active catalyst (CH
4
: O
2
= 8.2: 16.7 μmol h
−1
). We believe that the formation of the W-O-C-W-O species is a critical step in the catalytic pathways. This work provides an atomic-level comprehension of the structural defects of catalysts for activating small molecules.
Homeland of Karenic languages
Authors: Kato Atsuhiko
Published: April 2024

Comparisons of plant names in Karenic languages reveal that names that can be traced back to Proto-Karen belong to plants that grow in temperate zones, such as bamboo, banyan, and mango. The names for coconut and palmyra palm, which are typical tropical plants, cannot be traced back to Proto-Karen and are borrowings. This suggests that Proto-Karen was spoken in a temperate zone. Meanwhile, the highest diversity of Karenic languages is observed in the area from southern Shan State to Kayah State and northern Karen State in Myanmar. Thus, as per linguistic migration theory, this area may have been the homeland of Karenic languages. Furthermore, the area largely has temperate zones. Hence, we can assume that the homeland of Karenic languages was in this area.
Geolinguistic approach to migration history in the south-eastern edge of the Tibetosphere
Authors: Suzuki Hiroyuki
Published: April 2024

This article examines the migration history of Tibetic language-speaking people in the south-eastern corner of the
Tibetosphere, particularly the origin of Sangdam Tibetan, spoken in Kachin State, Myanmar, by adopting a geolinguistic approach
with linguistic maps. It first presents the current research progress of geolinguistics in the region and then discusses
phonological and lexical features to elucidate the dialect position of Sangdam Tibetan based on the data available in its adjacent
areas, such as Eastern Tibet and Yunnan in China. In addition, this study highlights the geolinguistic method’s potential and
difficulties in addressing migration history.
Reconstructing the decoupling of case and agreement in Old Hungarian
Authors: Halm Tamás
Published: April 2024

The interdependence of accusative case and object agreement has changed dramatically during the history of Ugric languages. While Proto-Ugric exhibited full interdependence (mediated by topicality), this connection has loosened in the extant Ob-Ugric languages (Mansi and Khanty), and it is severed completely in Late to Modern Hungarian. In this paper, I introduce new, hitherto unreported empirical evidence from nicknames and family names that preserve archaic syntactic features for an intermediate stage of Early Old Hungarian (which predates our earliest written records) where case assignment was still a function of topicality but object agreement was already a function of definiteness. In addition to providing insight into an unrecorded stage of Hungarian, my findings also contribute to a more thorough understanding of the connection between case, agreement and information structure in Ugric and beyond.
Case and agreement variation in contact
Authors: Zhang Yi , Yue Ming
Published: April 2024

This study investigates the influence of language contact on morphosyntactic variation in World Englishes, specifically focusing on the joint variation of case and agreement in it-clefts with pronominal clefted constituents. Employing a multifactorial approach within the framework of probabilistic grammar, we examine the distribution of the four relevant it-cleft variants in the GloWbE corpus. We find that language contact, as a language-external factor, impacts the strengths and rankings of language-internal factors but not their directions. Additionally, we observe an intricate interplay between language contact and language-internal factors in shaping morphosyntactic patterns: low-contact varieties tend to display feature-based case and agreement with a high degree of variability, while high-contact varieties tend to exhibit position-based case and agreement with a low degree of variability. These findings shed light on the mechanisms underlying the development of language diversity and structural simplification in World Englishes.
A proposal for a formalized, expandable approach to the taxonomy of writing systems
Authors: Osterkamp Sven , Schreiber Gordian
Published: April 2024

In this paper we propose a formalized and expandable approach to the taxonomy of writing systems. Taking the mixed
nature of writing systems fully into account, our approach focuses on the classification of functionally homogenous subsystems,
which together and in interaction with each other constitute an overall writing system. Such subsystems make use of a script or a
subset of a script, which is understood here as an inventory of graphs that is (conventionally considered to be) graphically
homogeneous. A basic distinction is made into phonographic and morphographic systems, but complemented by an in principle open
number of subtypes, building and expanding on Gnanadesikan (2017) and Poser (1992, 2004) for segmental and syllabic systems
respectively. Types are designated by a notation that employs a set of symbols, relating to both form (boundedness of graphs and
their organization into segmental spaces) and function (mapping type), but by separate means.
Chaos or system?
Authors: Joyce Terry , Masuda Hisashi
Published: April 2024

This paper seeks to reassess the balance between chaos and systematicity within the Japanese writing system (JWS),
which is noted for its complexity. As potential factors for chaos, Section 2 focuses on two
important conventions. The first is the simultaneous use of multiple scripts as components of a largely systematic whole, even
though it also affords considerable levels of graphematic variation. The second convention of dual-readings turns on kanji
graphematically mapping to both Native-Japanese (NJ) and Sino-Japanese (SJ) morphemes, which yields the JWS’s intriguing form of
morphography. However, as a factor that is, to a considerable degree, a major source of systematicity, Section 3 outlines the graphematic representation of SJ compound words. More specifically, starting from the
morphological structures of two-kanji compound words (2KCWs), Section 3 introduces the
dominant morphological patterns of three-kanji (3KCWs) and four-kanji compound words (4KCWs), which underscore the significance of
2KCWs within the Japanese mental lexicon, and concludes by noting Hatano, Kuhara, and Akiyama’s (1981) study about inferring the meanings of SJ compound words.
Koineization and the Pamphylian alphabet
Authors: Selvi Eleonora
Published: April 2024

In the Hellenistic age, contact with the Ionic alphabet used to write koine Greek rapidly changed the Pamphylian
alphabet, initiating the processes of koineization and standardization. The analysis of three case studies (personal names with
-muu̯a; personal names built from the root ϝαναξ-; -αυ and -ευ diphthongs) shows how the need to write
dialectal personal names led to the creation of a ‘local standard’ of spellings suited to the koine alphabetic set. However, some
features of the epichoric alphabet survived in competition with this local standard. It is therefore argued that the process of
standardization of the Pamphylian alphabet in contact with the koine alphabet affected different alphabetic features according to
the social and identity values given to them by the community.
De Sitter-like configurations with asymptotic quintessence environment
Authors: Giambò Roberto , Luongo Orlando
Published: April 2024

We examine a spherically-symmetric class of spacetimes carrying vacuum energy, while considering the influence of an external dark energy environment represented by a non-dynamical quintessence field. Our investigation focuses on a specific set of solutions affected by this field, leading to distinct kinds of spacetime deformations, resulting in regular, singular, and wormhole solutions. We thoroughly discuss the underlying physics associated with each case and demonstrate that more complex deformations are prone to instability. Ultimately, we find that our results lead to anisotropic de Sitter-like solutionthat behaves as a quintessence fluid. To achieve this, we investigate the nature of the corresponding fluid, showing that it cannot provide the sound speed equal to a constant equation of state parameter near the center. Consequently, we reinterpret the fluid as a slow-roll quintessence by investigating its behavior in asymptotic regimes. Further, we explore the potential implications of violating the isotropy condition on the pressures and we finally compare our findings with the de Sitter and Hayward solutions, highlighting both the advantages and disadvantages of our scenarios.
Electrical arc discharge in air between Pt-coated NEMS electrodes at nanoscale separation
Authors: Mamun Md Ataul , Smith Bennett , Horstmann Benjamin , Özgür Ümit , Avrutin Vitaliy
Published: April 2024

A thorough understanding of arc discharge mechanism as well as determination of arc discharge voltage at the nanometer scale remains challenging due to the complexities associated with electrode preparation and precisely maintaining nanoscale separations in experiments. This work addresses this challenge through a novel approach by accurately measuring electric breakdown/discharge voltages between Pt-coated Si electrodes with separations ranging from ∼5 nm to 370 nm using a combination of fixed and flexible nano-electrodes while inherently creating an ideal environment to mitigate the effect of mechanical vibrations on the measurement results. For separations of 10, 100, and 300 nm, the corresponding discharge voltages are ∼15, 75, and 160 V, respectively, with the apparent electric field for the 10 nm separation exceeding 1.5 GV m−1. The results acquired from the investigated electrode configuration closely resembling the laterally actuated nanoelectromechanical system (NEMS) cantilever relays reveals strong agreement with NEMS relay breakdown characteristics, emphasizing the importance of arc discharge considerations while designing micro/nano electromechanical devices. Furthermore, deliberately applied arc discharge is shown to provide electrode nano-welding for realization of configurable NEMS circuits.
Temperature-dependent epitaxial evolution of carbon-free corundum α-Ga2O3 on sapphire
Authors: Dai Lei , Hao Jinggang , Cui Mei , Zhang Yanfang , Kuang Yue , Wang Zhengpeng , Ren Fang-Fang , Gu Shulin , Ye Jiandong
Published: April 2024

Unintentionally doped carbon impurities from organometallic precursors are primary sources of carrier compensation and mobility degradation in wide bandgap semiconductors, leading to lowered performance of power electronic devices. To address this challenge, carbon-free α-Ga2O3 single-crystalline thin films were heteroepitaxially grown on sapphire substrates by using gallium inorganic precursors through a mist chemical vapor deposition technique. Determined through a temperature dependence of growth rates, three distinct growth regimes are identified: the surface reaction limited regime below 480 °C, the mid-temperature mass-transport limited regime (480 °C–530 °C) and the high temperature limited regime related to desorption or phase transition. With an optimized around 530 °C, the densities of screw and edge dislocations are reduced to 7.17 × 106 and 7.60 × 109 cm−2, respectively. Notably, carbon incorporation was eliminated in the α-Ga2O3 grown by inorganic GaCl3, as evidenced by the absence of carbon-related vibrational bands in Raman scattering analysis, while crystalline quality was comparable to that grown with organometallic precursors. The high solubility of GaCl3 in water is expected to enable the rapid growth of high purity α-Ga2O3 with improved electronic transport performances.
A flexible self-cleaning/antibacterial PVDF/T-ZnO fabric based on piezo-photocatalytic coupling effect for smart mask
Authors: Li Qihao , Lin Rui , Tang Zhaoxiang , Liang Shan , Xue Xinyu , Xing Lili
Published: April 2024

A novel flexible composite fabric has been engineered by combining piezoelectric poly (vinylidene fluoride) (PVDF) and tetrapod zinc oxide (T-ZnO) nanostructures, which are integrated onto a nonwoven fabric substrate. This fabric exhibits a wide array of functionalities, notably self-cleaning and antibacterial properties, facilitated by the synergistic piezo-photocatalytic coupling effect. Through the utilization of the piezoelectric effect inherent in PVDF/T-ZnO in tandem with the photocatalytic attributes of T-ZnO nanostructures, the fabric achieves concurrent degradation of organic pollutants and antibacterial efficacy when exposed to mechanical vibration and solar irradiation. The piezo-photocatalytic coupling effect engenders an internal electric field that aids in the effective separation of photo-generated carriers (electrons and holes), thereby diminishing recombination rates and augmenting the efficiency of the photocatalytic degradation process. Notably, organic pollutants such as methylene blue and azithromycin exhibit degradation levels of 96.0% and 92.6%, respectively, within a timeframe of 25 and 60 min. The incorporation of PVDF/T-ZnO results in an approximate 40% enhancement in the degradation rate of organic substances compared to the use of T-ZnO in isolation. Furthermore, the composite fabric showcases exceptional antibacterial efficacy, effectively inhibiting the proliferation of Staphylococcus aureus. Experimental findings reveal that the average antibacterial zone diameter of the PVDF/T-ZnO fabric measures at 7.68 mm, significantly surpassing that of the T-ZnO fabric and nonwoven fabric. Given its remarkable self-cleaning and antibacterial attributes, the PVDF/T-ZnO fabric exhibits substantial potential for diverse applications, including the development of intelligent masks tailored for deployment in healthcare settings and polluted environments.
Numerical simulation of electric field-induced phase transition evolution and boiling characteristics in the evaporative cooling medium C6F12O
Authors: Tian Shuangshuang , Wang Jiahao , Wu Yingyu , Hu Feng , Luo Yongchao , Zhang Chaohai , Gao Shen , Yuan Zian
Published: April 2024

Phase change cooling technology offers high cooling efficiency, safety, and reliability, representing a novel approach to achieving efficient heat dissipation for high-power and large-capacity electrical equipment. The formulation of the cooling medium is pivotal to phase change cooling technology. However, current media exhibit compatibility, stability, economy, and environmental friendliness deficiencies. Consideration could be given to implementing the C6F12O medium due to its superior overall performance and ability to meet the latent heat requirements in phase change cooling equipment. This paper employs a numerical simulation approach that combines the phase field method based on the Cahn-Hilliard equation with the theory of electrohydrodynamics. It investigates the impact of temperature, electric field intensity, and electric field direction on the evolution of bubble motion and the boiling state of the C6F12O medium, considering the interaction of electric-fluid-heat-phase fields. Numerical results indicate that the system undergoes initial nucleate boiling, nucleate boiling, and film boiling stages at T = 330–335 K, T = 335–350 K, and T ⩾ 355 K, respectively. The introduction of an appropriate electric field can enhance the motion evolution of C6F12O bubbles. However, attention must be paid to the formation of bubble channels under high field strength to prevent potential decreases in insulation performance. An inhomogeneous electric field in the vertical direction proves more effective in improving the bubble release rate compared to a uniform electric field. To some extent, an inhomogeneous electric field in the horizontal direction can prevent the mass accumulation of bubbles in regions of high field intensity. This research has the potential to offer theoretical guidance for the engineering application of the C6F12O phase change cooling medium.
Direct growth of highly oriented GaN thin films on silicon by remote plasma CVD
Authors: Watrin Lise , Silva François , Jadaud Cyril , Bulkin Pavel , Vanel Jean-Charles , Muller Dominique , Johnson Erik V , Ouaras Karim , Roca I Cabarrocas Pere
Published: April 2024

We report on low-temperature (500 °C) and low-pressure (0.3 mbar) direct growth of GaN thin films on silicon (100) substrates using remote plasma chemical vapour deposition (RP-CVD). In the custom-designed reactor, an RF inductively coupled plasma is generated remotely from the substrate’s area to facilitate the decomposition of group-V precursor, N2 with added H2, while group-III precursor trimethylgallium (TMGa), is directly injected into the growth chamber mixed with H2 carrier gas. Growth parameters such as RF power, process pressure and gas flow rates have been optimized to achieve a film growth rate of about 0.6 µm h−1. Several characterization techniques were used to investigate the plasma and the properties of the grown thin films in terms of their crystallinity, morphology, topography, and composition. The films are highly textured with a preferential orientation along the c-axis of the wurtzite structure. They present a small roughness in the nanometer range and a columnar microstructure with a grain size of one hundred nanometer, and a gallium polarity (+c plane oriented). Rutherford backscattering spectrometry and nuclear reaction analysis show that the chemical composition is homogeneous through the depth of the layer, with a III/V ratio close to 1, a very low content of oxygen (below the detection limit ∼1%) and a carbon content up to 11%. It was shown that the increase of plasma power helps to reduce this carbon contamination down to 8%. This research paves the way for a growth method compatible with cost reduction of III–V thin film production achieved through reduced gas consumption facilitated by RP-CVD operation at low pressure.
Stimuli-responsive photoluminescent and structural properties of MIL-53(Al) MOF for sensing applications
Authors: Rehman T Ul , Agnello S , Gelardi F M , Calvino M M , Buscarino G , Cannas M
Published: April 2024

Metal–organic frameworks (MOFs) are an intriguing group of porous materials due to their potential influence on the development of indispensable technologies like luminescent sensors and solid-state light devices, luminescent multifunctional nanomaterials. In this research work we explored MIL-53(Al), an exceptional class of MOF that, along with guest adsorption, undergoes structural transitions exhibiting breathing behavior between narrow pore and large pore under temperature and mechanical stress. Therefore, we opted for the time resolved luminescence and FT-Raman spectroscopy to investigate the mechanochromic and thermochromic response of this material under external stimuli. Intriguingly, when subjected to temperature changes, MIL-53(Al) exhibited a ratiometric fluorescence behavior related to the reversible relationship of photoluminescence emission intensity with respect to temperature. Moreover, under higher mechanical stress MIL-53(Al) displayed turn-on behavior in emission intensity, hence offering a thrilling avenue for the application in mechanically deformed-based luminescent sensors and ratiometric fluorescence temperature sensors.
Precise refractive index measurement of fused silica optics
Authors: Jagroop  , Tillo Dakshin , Narayanamurthy C S , Sam Dayala Dev D
Published: April 2024

We have developed an experimental platform that non-destructively and precisely measures the Refractive Index (RI) and dispersion of ultra-polished fused silica optics. Using Total Internal Reflection Digital Holographic Microscopy (TIRDHM), we exploit the phase change of reflected light in Total Internal Reflection (TIR) mode. This phase change depends on the incident angle at the TIR interface and the refractive indices of the involved media. We have optimized a combination of higher TIR phase sensitivity, considerable penetration depth, and minimized phase measurement inaccuracies through simulations to design our experiment. Key features include a custom-made precision Right-Angle Prism (RAP) of Astrositall material, a seamless interface with fused silica optics on TIR interface through optical contact, and single-shot measurement. We have demonstrated the accuracy of measuring fused silica optics through proof of concept and experimental results. Our measurements on two different samples show accuracy better than ±3 × 10−4 compared to those obtained using a commercially available critical angle Refractometer (Metricon). Importantly, the setup offers the advantage of spatially mapping the refractive index, unlike point measurements by available Refractometers.
Prediction of mechanical properties of LPBF built part based on process monitoring and Gaussian process regression
Authors: Yuan Zhenghui , Peng Xiaojun , Ma ChenGuang , Zhang Aoming , Chen Zhangdong , Jiang Zimeng , Zhang Yingjie
Published: April 2024

As a highly promising technology in additive manufacturing, the laser powder bed fusion has only limited application due to its low reproducibility. In this study, the image information of the 316L specimen after laser scanning and powder paving of each layer was acquired by a complementary metal–oxide–semiconductor industrial camera. The important features were selected, extracted and quantificated by analyzing the tensile test results. Finally, combined with the laser power, the quantified features were as input of a Gaussian process regression model based on optimization algorithm of grid search to predict the tensile strength of 316L specimen. The results show that the quantized image features have a significant improvement on the regression effect, and the coefficient of determination (R
2) is improved from 63% to 90.57% compared to using only the laser power as input.
Two-dimensional LSTM soft sensor using noisy process data
Authors: Liu Qiao , Jia Mingwei , Guo Xiaowei , Liu Yi , Gao Zengliang , Xu Liangfeng
Published: April 2024

Establishing a reliable data-based soft sensor still faces a series of challenges, particularly the presence of outliers and different kinds of noise which are non-negligible in process data. To address these challenges, a correntropy-based two-dimensional long short-term memory (TLSTM) model is developed to handle noisy process data. First, the multidimensional time series samples are reconstructed into numerous two-dimensional input matrices in the feature and time directions. Then, the convolution and pooling operations are used to extract useful information in the process variables related to the quality variable. Meanwhile, a gating mechanism is employed to learn the internal representation of time series. Finally, a correntropy-based strategy is utilized to assign relatively small weights to outliers automatically, enabling reliable prediction. Two cases illustrate the reliability and advantages of TLSTM in effectively extracting quality-related features for prediction.
Inter-scanner super-resolution of 3D cine MRI using a transfer-learning network for MRgRT
Authors: Yoon Young Hun , Chun Jaehee , Kiser Kendall , Marasini Shanti , Curcuru Austen , Gach H Michael , Kim Jin Sung , Kim Taeho
Published: April 2024

Objective. Deep-learning networks for super-resolution (SR) reconstruction enhance the spatial-resolution of 3D magnetic resonance imaging (MRI) for MR-guided radiotherapy (MRgRT). However, variations between MRI scanners and patients impact the quality of SR for real-time 3D low-resolution (LR) cine MRI. In this study, we present a personalized super-resolution (psSR) network that incorporates transfer-learning to overcome the challenges in inter-scanner SR of 3D cine MRI. Approach: Development of the proposed psSR network comprises two-stages: (1) a cohort-specific SR (csSR) network using clinical patient datasets, and (2) a psSR network using transfer-learning to target datasets. The csSR network was developed by training on breath-hold and respiratory-gated high-resolution (HR) 3D MRIs and their k-space down-sampled LR MRIs from 53 thoracoabdominal patients scanned at 1.5 T. The psSR network was developed through transfer-learning to retrain the csSR network using a single breath-hold HR MRI and a corresponding 3D cine MRI from 5 healthy volunteers scanned at 0.55 T. Image quality was evaluated using the peak-signal-noise-ratio (PSNR) and the structure-similarity-index-measure (SSIM). The clinical feasibility was assessed by liver contouring on the psSR MRI using an auto-segmentation network and quantified using the dice-similarity-coefficient (DSC). Results. Mean PSNR and SSIM values of psSR MRIs were increased by 57.2% (13.8–21.7) and 94.7% (0.38–0.74) compared to cine MRIs, with the reference 0.55 T breath-hold HR MRI. In the contour evaluation, DSC was increased by 15% (0.79–0.91). Average time consumed for transfer-learning was 90 s, psSR was 4.51 ms per volume, and auto-segmentation was 210 ms, respectively. Significance. The proposed psSR reconstruction substantially increased image and segmentation quality of cine MRI in an average of 215 ms across the scanners and patients with less than 2 min of prerequisite transfer-learning. This approach would be effective in overcoming cohort- and scanner-dependency of deep-learning for MRgRT.
OSLD nanoDot characterization for carbon radiotherapy dosimetry
Authors: Taylor Paige A , Hartzell Shannon , Mirandola Alfredo , Ciocca Mario , Magro Giuseppe , Alvarez Paola , Peterson Christine B , Peeler Christopher R , Koay Eugene J , Howell Rebecca M , Kry Stephen F
Published: April 2024

Objective. This study characterized optically-stimulated luminescent dosimeter (OSLD) nanoDots for use in a therapeutic carbon beam using the Imaging and Radiation Oncology Core (IROC) framework for remote output verification. Approach. The absorbed dose correction factors for OSLD (fading, linearity, beam quality, angularity, and depletion), as defined by AAPM TG 191, were characterized for carbon beams. For the various correction factors, the effect of linear energy transfer (LET) was examined by characterizing in both a low and high LET setting. Main results. Fading was not statistically different between reference photons and carbon, nor between low and high LET beams; thus, the standard IROC-defined exponential function could be used to characterize fading. Dose linearity was characterized with a linear fit; while low and high LET carbon linearity was different, these differences were small and could be rolled into the uncertainty budget if using a single linearity correction. A linear fit between beam quality and dose-averaged LET was determined. The OSLD response at various angles of incidence was not statistically different, thus a correction factor need not be applied. There was a difference in depletion between low and high LET irradiations in a primary carbon beam, but this difference was small over the standard five readings. The largest uncertainty associated with the use of OSLDs in carbon was because of the k
Q correction factor, with an uncertainty of 6.0%. The overall uncertainty budget was 6.3% for standard irradiation conditions. Significance. OSLD nanoDot response was characterized in a therapeutic carbon beam. The uncertainty was larger than for traditional photon applications. These findings enable the use of OSLDs for carbon absorbed dose measurements, but with less accuracy than conventional OSLD audit programs.
Effect of SiC nanoparticles on mechanical and damping properties of epoxy/polysulfide rubber blend composite
Authors: AlHumairee Salwan Hasan , Hunain Mustafa Baqir , Mahmood Ibtihal A
Published: April 2024

Blend polymer matrix composite material are becoming more and more popular due to their promising mechanical properties. In this research, blend polymer mixture was make from epoxy resin (EP) blended with different weight percentages of polysulfide rubber (PSR) (0, 3, 6, 10, 15, and 20%). Then tensile, impact, bending strength and damping ratio were evaluated to get the high quality of mechanical properties for the blend matrix. Due to the requirements to enhance the mechanical properties of this blend; a various weight fraction of carbide silica (SiC) nanoparticle was used as a reinforcement in the ratios of (0, 1, 3, and 5%) by weight to the best ratio of the blended matrix. Tensile, impact, bending and damping ratio tests were also conducted to get the best mechanical properties for the blend materials. Experimental results for the blend matrix showed that adding polysulfide rubber to epoxy resin resulted in a decrease in Young’s modulus, tensile strength, and bending strength; however damping ratio and the impact strength increased. It is found that the weight fraction of 6% of PSR is the Better case, which gave the better mechanical characteristics properties for mixture. Utility of this mixture; it has intermediates between flexible properties of a mixture at the highest rate of PSR and brittle mechanical properties for EP resin. Mechanical and damping properties showed an increasing when the carbide silica (SiC) with a weight fraction of 3% added, then it decreased slightly.
Amplifying the capacity of quantum super dense coding by non-Hermitian operations under phase decoherence source
Authors: Wang Qiong , He Zhi
Published: April 2024

We study the dynamic behavior of quantum super dense coding between two uncoupled qubits, which are immersed in a common Ohmic environment. We examine the validity of local non-Hermitian operations in the amplification of quantum super dense coding. In particular, using analytical and numerical investigations, we show explicitly that the capacity of quantum super dense coding can be greatly amplified with the assistance of a local non-Hermitian operation, i.e. a parity-time symmetric operation. This sheds new light on the protection of quantum super density.
p-wave resonances in the exponential cosine screened Coulomb potential*
Authors: Wang Yuan-Cheng , Jiao Li Guang , Liu Aihua , Ho Yew Kam , Fritzsche Stephan
Published: April 2024

We perform benchmark calculations of the p-wave resonances in the exponentially cosine screened Coulomb potential using the uniform complex-scaling generalized pseudo-spectral method. The present results show significant improvement in calculation accuracy compared to previous predictions and correct the misidentification of resonance electron configuration in previous works. It is found that the resonance states approximately follow an n
2-scaling law which is similar to the bound counterparts. The birth of a new resonance would distort the trajectory of an adjacent higher-lying resonance.
Influence of liquid film shape on evaporation performance of agitated thin film evaporator
Authors: Gu 顾 Xin-Qiang 鑫强 , Huang 黄 Yao 瑶 , Zou 邹 Kun 鲲 , Peng 彭 Yi-Tian 倚天
Published: April 2024

The agitated thin film evaporator (ATFE), which is known for its high efficiency, force the material to form a film through the scraping process of a scraper, followed by evaporation and purification. The complex shape of the liquid film inside the evaporator can significantly affect its evaporation capability. This work explores how change in shape of the liquid films affect the evaporation of the materials with non-Newtonian characteristics, achieved by changing the structure of the scraper. Examining the distribution of circumferential temperature, viscosity, and mass transfer of the flat liquid film shows that the film evaporates rapidly in shear-thinning region. Various wavy liquid films are developed by using shear-thinning theory, emphasizing the flow condition in the thinning area and the factors contributing to the exceptional evaporation capability. Further exploration is conducted on the spread patterns of the wavy liquid film and flat liquid film on the evaporation wall throughout the process. It is noted that breaking the wavy liquid film on the evaporating wall during evaporation is challenging due to its film-forming condition. For which the fundamental causes are demonstrated by acquiring the data regarding the flow rate and temperature of the liquid film. The definitive findings of the analysis reveal a significant improvement in the evaporation capability of the wavy liquid film. This enhancement is attributed to increasing the shear-thinning areas and maintaining the overall shape of the film throughout the entire evaporation process.
Light-emitting devices based on atomically thin MoSe2
Authors: Zhang Xinyu , Zhang Xuewen , Hu Hanwei , Zhang Vanessa Li , Xiao Weidong , Shi Guangchao , Qiao Jingyuan , Huang Nan , Yu Ting , Shang Jingzhi
Published: April 2024

Atomically thin MoSe2 layers, as a core member of the transition metal dichalcogenides (TMDs) family, benefit from their appealing properties, including tunable band gaps, high exciton binding energies, and giant oscillator strengths, thus providing an intriguing platform for optoelectronic applications of light-emitting diodes (LEDs), field-effect transistors (FETs), single-photon emitters (SPEs), and coherent light sources (CLSs). Moreover, these MoSe2 layers can realize strong excitonic emission in the near-infrared wavelengths, which can be combined with the silicon-based integration technologies and further encourage the development of the new generation technologies of on-chip optical interconnection, quantum computing, and quantum information processing. Herein, we overview the state-of-the-art applications of light-emitting devices based on two-dimensional MoSe2 layers. Firstly, we introduce recent developments in excitonic emission features from atomically thin MoSe2 and their dependences on typical physical fields. Next, we focus on the exciton-polaritons and plasmon-exciton polaritons in MoSe2 coupled to the diverse forms of optical microcavities. Then, we highlight the promising applications of LEDs, SPEs, and CLSs based on MoSe2 and their heterostructures. Finally, we summarize the challenges and opportunities for high-quality emission of MoSe2 and high-performance light-emitting devices.
Hybrid bonding of GaAs and Si wafers at low temperature by Ar plasma activation
Authors: Huang Rui , Wang Zhiyong , Wu Kai , Xu Hao , Wang Qing , Guo Yecai
Published: April 2024

High-quality bonding of 4-inch GaAs and Si is achieved using plasma-activated bonding technology. The influence of Ar plasma activation on surface morphology is discussed. When the annealing temperature is 300 ℃, the bonding strength reaches a maximum of 6.2 MPa. In addition, a thermal stress model for GaAs/Si wafers is established based on finite element analysis to obtain the distribution of equivalent stress and deformation variables at different temperatures. The shape variation of the wafer is directly proportional to the annealing temperature. At an annealing temperature of 400 ℃, the maximum protrusion of 4 inches GaAs/Si wafers is 3.6 mm. The interface of GaAs/Si wafers is observed to be dense and defect-free using a transmission electron microscope. The characterization of interface elements by X-ray energy dispersion spectroscopy indicates that the elements at the interface undergo mutual diffusion, which is beneficial for improving the bonding strength of the interface. There is an amorphous transition layer with a thickness of about 5 nm at the bonding interface. The preparation of Si-based GaAs heterojunctions can enrich the types of materials required for the development of integrated circuits, improve the performance of materials and devices, and promote the development of microelectronics technology.
Shoulder viscoelasticity in a raptor-inspired model alleviates instability and enhances passive gust rejection
Authors: Stanton Samuel C
Published: April 2024

Recent experiments with gliding raptors reveal a perplexing dichotomy: remarkably resilient gust rejection, but, at the same time, an exceptionally high degree of longitudinal instability. To resolve this incompatibility, a multiple degree of freedom model is developed with minimal requisite complexity to examine the hypothesis that the bird shoulder joint may embed essential stabilizing and preflexive mechanisms for rejecting rapid perturbations while simplifying and reducing control effort. Thus, the formulation herein is centrally premised upon distinct wing pitch and body pitch angles coupled via a Kelvin–Voigt viscoelastic shoulder joint. The model accurately exhibits empirical gust response of an unstable gliding raptor, generates biologically plausible equilibrium configurations, and the viscoelastic shoulder coupling is shown to drastically alleviate the high degree of instability predicted by conventional linear flight dynamics models. In fact, stability analysis of the model predicts a critical system timescale (the time to double amplitude of a pitch divergence mode) that is commensurate with in vivo measured latency of barn owls (Tyto alba). Active gust mitigation is studied by presupposing the owl behaves as an optimal controller. The system is under-actuated and the feedback control law is resolved in the controllable subspace using a Kalman decomposition. Importantly, control-theoretic analysis precisely identifies what discrete gust frequencies may be rapidly and passively rejected versus disturbances requiring feedback control intervention.