bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transformer fault diagnosis based on DBO-BiLSTM algorithm and LIF technology
Authors: Yan Pengcheng , Wang Jingbao , Wang Wenchang , Li Guodong , Zhao Yuting , Wen Ziming 
Published: July 2024

Abstract
In response to the deficiencies of traditional power transformer fault detection techniques, such as low sensitivity and the inability for online monitoring, a novel transformer fault diagnosis model combining laser-induced fluorescence (LIF) technology with deep learning is proposed. Initially, the spectral data of transformer insulation oil is acquired using LIF technology, yielding spectral data for various fault types. Subsequently, MinMaxScaler and standard normalized variate methods are employed for denoising and preprocessing the spectral data. The preprocessed data is then subjected to dimensionality reduction using linear discriminant analysis and T-distributed stochastic neighbor embedding to ensure that the spectral data retains maximal feature information while minimizing its dimensionality. Following this, long short-term memory, bidirectional long short-term memory (BiLSTM), dung beetle optimizer-BiLSTM, convolutional neural network, and support vector machine models are constructed. The reduced-dimensional data is fed into each of the five models for training to facilitate transformer fault diagnosis. Through comparative analysis among the five models, the optimal model is selected. Experimental results indicate that the dung beetle optimization-BiLSTM model is the most suitable for transformer fault diagnosis in this experiment, underscoring its significant implications for ensuring the safety of power systems.
Wm-algebras and fractional powers of difference operators
Authors: Beffa Gloria Marí 
Published: July 2024

AbstractIn this paper we define a Poisson pencil associated to a latticeWm-algebras defined in a recent paper by Izosimov and Marí Beffa (2023Int. Math. Res. Not.202317021–59). We then prove that this Poisson pencil is equal to the one defined in 2013 by Marí Beffa and Wang (2013Nonlinearity262515) and the author using a type of discrete Drinfel’d–Sokolov reduction. We then show that, much as in the continuous case, a family of Hamiltonians defined by fractional powers of difference operators commute with respect to both structures, defining the kernel of one of them and creating an integrable hierarchy in the Liouville sense.
From minimum-viable-products to full models: a step-wise development of diagnostic forward models in support of design, analysis and modelling on the ST40 tokamak
Authors: Sertoli Marco , Alieva A , Buxton P F , Dnestrovskii A , Gemmell M , Lowe H , O’Gorman T , Osin D , Sladkomedova A , Varje J , Willett H V , Wood J , Lomanowski Bart A , Delabie E , Marchuk O , Litherland-Smith E , Collie K , Gadgil S ,   the Tokamak Energy Team
Published: July 2024

Abstract
Like most magnetic confined fusion experiments, the ST40 tokamak started off with a small subset of diagnostics and gradually increased the diagnostic set to include more complex and comprehensive systems. To make the most of each operational phase, forward models of various diagnostics are used and developed to aid design, provide consistency-checks during commissioning, test analysis methods, and build workflows to constrain high-level parameters to inform interpretation, theory and modelling. For new models and new analysis workflows, minimum-viable-products are released early, and their complexity is increased in a step-wise manner, facilitating the support of all programme phases on multiple parallel applications, while enabling learning opportunities and feedback loops. In this contribution we review the philosophy, scope and architecture of the framework under development. We discuss the details of some forward models, with examples on how they are used to aid diagnostic design, to investigate analysis methodologies through synthetic data, and how they are embedded in experimental analysis workflows. We compare previously published experimental results with new, more advanced analysis workflows employing more recent, detailed models and new diagnostic data, providing confirmation of the published material from the 2021–22 experimental campaign.
Variations of plasma potential in RF discharges with DC-grounded electrode
Authors: Hiret Paul , Tognina Patrik , Faudot Eric , Steiner Roland , Dmitriev Artem , Marot Laurent , Meyer Ernst 
Published: July 2024

Abstract
The self-bias voltage

V

bias

and the plasma potential

V

p

are the key parameters to control plasma-wall interactions in radio-frequency (RF) asymmetric plasma discharges. Knowing these two parameters allows to monitor the ion energy distribution on the electrode surface. However, in a direct current (DC) coupled plasma, the plasma potential increased to hundreds of volts while no more

V

bias

developed on the driven electrode. In addition, the plasma potential is strongly impacted by the electrode-wall area ratio. Several analytical or semi-analytical models exist to explain this phenomenon and to approximate the plasma potential, knowing the electrode-wall area ratio considering capacitive sheaths or a combination of resistive and capacitive sheaths. The

V

p

and several other plasma parameters were investigated experimentally with a Langmuir probe and a Retarding field energy analyser for different electrode/wall area ratios in low-temperature RF plasma. The validity of the models was studied for an extensive range of area ratios with different pressures and RF driving amplitude. Moreover, the presence of strong stochastic heating of the plasma for area ratios below 6 was evidenced by an increased ion flux and an increased electron temperature.
SPR based dual parameter wide range curling pot shaped photonic crystal fiber sensor
Authors: Guo Pengxiao , Du Huijing , Li Jianshe , Li Yuxin , Li Shuguang , Yin Zhiyong , Wang Ruiduo , Li Kaifeng , Li Hongwei , Li Xingwei 
Published: July 2024

Abstract
This article proposes a curling pot shaped photonic crystal fiber (PCF) sensor based on surface plasmon resonance (SPR), which utilizes two parallel polished surfaces in the cladding to achieve dual parameter measurements of liquid refractive index (RI) and temperature. The mode characteristics and sensing performance of the designed PCF sensor are studied using the finite element method, and the effects of changes in structural parameters such as pore radius, spacing, and gold film thickness on the resonance spectrum are analyzed. The sensing accuracy of the sensor is insensitive to the change of structural parameters, and it has the characteristics of a wide detection range, high sensitivity, and easy manufacture. When the measured RI is in the range of 1.33∼1.42, the maximum RI sensitivity is 20400 nm RIU−1, and the maximum FOM is 483.3 RIU−1. When the temperature ranges from −10 °C to 100 °C, the maximum sensitivity is 15.4 nm °C−1, and the maximum FOM is 0.43 RIU−1. The tight structure design of the sensor core close to the polishing surface and the anti-spill light design with a uniform arrangement of air holes enhance the SPR effect, which is the essential reason for achieving a wide detection range and high sensitivity.
Investigations for the heat treatment effects on permeability of some semi-permeable membranes
Authors: Abdel-Hai S I , El-Tonsy M M , El-Henawey M I 
Published: July 2024

Abstract
The current study aims to devise a mechanism that can regulate the permeability of semi-permeable membranes, either by enhancing or reducing it, based on their intended application. This approach seeks to offer a straightforward and efficient method for controlling membrane permeability. Cellulose acetate (CA) and cellulose triacetate (CTA) membranes were subjected to two different heat treatment processes. One method involved thermal annealing at relatively high temperatures, while the other method involved freezing the membranes when they were saturated with water. A special osmosis cell was designed and utilized to quantify the flow rates across the treated CA and CTA membranes. Our findings indicate that subjecting the membranes to high-temperature annealing decreased the flow rate. Conversely, the freezing treatment boosted the flow rate, thereby enhancing membrane permeability. This approach could pave the way for numerous applications across various fields.
Effects of nanocutting environments on the electronic structure of armchair-type graphene nanoribbons: the first-principles study
Authors: Tang Meiling , Yuan Zewei , Sun Jingting , He Yan , Ran Di , Wang Ying , Feng Yusen , Zhou Xinbo 
Published: July 2024

Abstract
In order to investigate the effect of nanocutting environment on the electronic structure of armchair-type graphene nanoribbons, this paper adopts a first-principle computational approach to study the effect of different substrates and solutions, such as on the motion of electrons in the middle and outer orbitals of graphene nanoribbons, by observing the energy band structure, the value of the band gap, and the density of the split-wave states. The results show that the adsorption of Si and C atoms at the edge of the nanoribbon leads to a decrease in the band gap value. The adsorption of Al and O atoms at the edges of graphene nanoribbons leads to a decrease in the nanoribbon band gap value to 0 eV. Different substrate atoms mainly affect the p-orbital electron motion in the nanobelt. Bare-edge graphene nanoribbons are indirect bandgap structures, and graphene nanoribbons with H, O and OH atoms adsorbed at the edges of the nanoribbons are direct bandgap structures. Edge O-isation leads to a nanobelt band gap of 0, which exhibits metallic properties. The edge H-isation nanoribbon band gap is higher than the bare edge nanoribbon band gap. Nanoribbon edge OH-isation reduces the nanoribbon band gap value. Nanoribbon edge adsorption of atoms in solution affects p-orbital electron motion. The formation energy of five-ring defects and seven-ring defects is low, and the defects are easier to form. The edges containing defects all reduce the band gap values of graphene nanoribbons. The defects mainly affect the p-orbital electron motion, leading to differences in the band gap values. The bandgap decreases with increasing nanobelt width, and the bandgap value conforms to 3 N+2<3 N<3 N+1, with regular fluctuations in the curve with period 3. The larger the band gap, the smaller the curvature of the curve at the extremes, and the sparser the curve. In this paper, the electronic structures of different edge structures are analysed from a quantum mechanical point of view, and the synthesis of these results will provide theoretical guidance for obtaining high-quality semiconductor nanoribbons by mechanochemical nanocutting.
Cosmological constraints on the background dynamics of a two-field nonsingular bounce model
Authors: Ri Kang Song , Hwang Sin Chol , Ri Hyon Chol 
Published: July 2024

Abstract
In this study, we consider a nonsingular two-field bounce scenario with non-minimal kinetic coupling between two scalar fields. We derive constraints on the model parameters from the finiteness of the physical quantities at the classical level and from the relation between the late-time accelerated expansion and particle production up to the bounce phase. We then determine the allowed parameter space for the model.
Divertor heat load estimates on NSTX and DIII-D using new and open-source 2D inversion analysis code
Authors: Adebayo-Ige P.O. , Gan K.F. , Lasnier C.J. , Maingi R. , Wirth B.D. 
Published: July 2024

Abstract
A thermography inversion algorithm has been developed in the open-source Python-based computer code, HYPERION, to calculate the heat flux incident on plasma-facing components (PFCs) in axisymmetric tokamaks. The chosen mesh size at the surface significantly affects the calculated transient heat flux results. The calculated transient heat flux will exceed the real value when the mesh size tends to zero but will underestimate the real value when the mesh size is large. A criterion for determining the appropriate mesh size for the transient heat flux calculation will be discussed. The numerical scheme for HYPERION uses a 2D fully implicit finite-difference approach, allowing temperature-dependent thermal properties of PFC materials. The inversion algorithm is benchmarked against established heat flux calculation codes, TACO and THEODOR, based on thermography data from NSTX and DIII-D respectively. The primary benefits of HYPERION compared to TACO and THEODOR are that it is open-source and it allows for the optimization of mesh thickness along the substrate. The algorithm also accounts for the thermal properties of thin surface layers that characteristically form on PFCs due to plasma-material interactions. The agreement between HYPERION and THEODOR is excellent, as the percent difference between the codes is ∼5% on average in the case of the DIII-D data for moderate to high heat flux. Verification tests with TACO show slightly higher average percent differences of 8% and 12%. In using HYPERION to study filaments in heat flux, the initial results indicate that small ELMs filaments significantly broaden the divertor heat flux, and decrease divertor peak flux. Compared to the inter-ELM, the small ELM filaments decrease the divertor peak surface temperature. With intermittent divertor filaments, the divertor heat flux width is comparable with that found in L-mode.
Blended lime plasters with biomass ash and natural fibres reinforcement
Authors: Keppert M , Pommer V , Šádková K , Botnari A , Vejmelková E , Koňáková D 
Published: July 2024

Abstract
The possibility to valorise biomass combustion ash in air lime based plaster was evaluated by means of mechanical properties. The possible effect of vegetable fibres (hemp, flax) was examined as well. The biomass ash improved significantly the mechanical properties of plaster. On the other hand, the vegetable fibres are limiting the compressive strength due to lower wettability between fibres and lime. However the fibres had positive effect on bending strength, as it is expected. The surface modification of fibres seems to be necessary in order to improve their performance in the lime system.
Mechanical properties of blended cements affected by impurities in thermally activated clays
Authors: Šádková K. , Pommer V. , Vejmelková E. , Koňáková D. 
Published: July 2024

Abstract
With the scarcity of raw materials, energy intensiveness and environmental burden connected with producing Portland cement, there is a growing need to find substitute binders. Thermally activated clay also appears to be a suitable material for partial cement replacement. However, not all clays are the same. It depends very much on the place of collection, its chemical and phase composition, and the activation temperature. This study compared six different types of clays fired at 600 °C in terms of quantitative phase analysis and mechanical strength results. In addition to the fineness of grinding and firing temperature, the clay composition had an immense impact on mechanical properties. Content of illite up to 20% was found to be beneficial, as this clay reached the highest mechanical strengths. Regarding the quartz, its presence did not harm the overall performance of thermally activated clays and the presence of calcite could cause the improvement of the mechanical strengths. However, the clay with the most miscellaneous composition caused the deterioration of compressive strength but reached much higher bending strength compared to pure cement.
Sol gel synthesis of TiO2@ZnO composites for self-cleaning and antimicrobial coating
Authors: Bruzl D. , Bocian L. , Sokola P. , Másilko J. , Sedlačík M. , Švec J. , Bartoníčková E. , Šoukal F. 
Published: July 2024

Abstract
In recent years, the development of advanced materials for applications in self-cleaning surfaces and antimicrobial coatings has received considerable attention due to its potential impact on environmental sustainability and public health. Among the emerging materials, metal oxide-based photocatalysts have shown promise in addressing these challenges. In this context, the present study focuses on the promise sol-gel synthesis and potential photocatalytic properties of TiO2@ZnO (x = 0.6 - 0.9) nano-scaled particles, with particular emphasis on their applications in self-cleaning and microbial coatings. The choice of TiO2@ZnO (x = 0.6 - 0.9) as the subject of investigation is driven by the advantageous properties of both titanium dioxide (TiO2) and zinc oxide (ZnO). TiO2 is known for its exceptional photocatalytic activity, while ZnO is known for its antimicrobial properties. By combining these two metal oxides in a controlled manner, we aim to harness their synergistic effects to create a multifunctional material with enhanced performance. A titanium (IV) isopropoxide and zinc acetate dihydrate have been used as precursors for the so-gel process. The synthesised powders were evaluated by X-ray diffraction analysis and Raman spectroscopy to determine the allotropy of TiO2 and possible lattice distortions. The optical band gap (Egap) was evaluated by molecular reflection UV-VIS spectroscopy. In addition, size and morphology were determined by scanning electron microscopy (SEM).
Utilization of alternative wood particles for modern thermal insulation products
Authors: Zach J , Peterková J , Novák V , Korjenic A 
Published: July 2024

Abstract
Thermal insulation materials play a vital role in minimising energy loss in building operation and also affect the amount of greenhouse gas emissions associated with heating and cooling. In this context, it is becoming an increasingly important milestone to find suitable thermal insulation materials that not only meet the technical requirements but also minimise their environmental impact. The trend towards the use of eco-friendly materials for thermal insulation reflects the construction industry’s desire to contribute to environmental protection and the transition to more sustainable models of building construction and renovation. For more than 20 years, a number of research teams have been investigating the possibility of replacing synthetically produced materials such as mineral wool and polystyrene foam with natural fibre-based insulation materials. These alternatives include wood as a traditional, easily renewable raw material. This, together with the low energy intensity of processing and manufacturing wood materials, contributes to its low carbon footprint. Compared to traditional synthetic insulation materials, which are often energy intensive to produce, wood is a more environmentally friendly choice. However, with many European countries now facing a potential shortage of higher quality wood, it is necessary to look for alternative sources of wood, including in the field of thermal insulation materials, materials with a lower carbon footprint that can be produced from lower quality wood or from wood waste that would otherwise only have an energy use. The paper is devoted to the study and use of suitable wood waste and secondary raw materials from spruce wood (coarse wood chips, sawdust and wood flour) for the development of modern thermal insulations with the aim of an environmentally friendly and less energy-intensive production process compared to conventional insulants.
Characterization and damage of the historic brick masonry of the Zákupy castle stables
Authors: Frankeová D , Bauerová P , Náhunková P , Slížková Z , Polák A M 
Published: July 2024

Abstract
A chemical-mineralogical analysis and mechanical tests of historical bricks were carried out as part of the construction-technical survey. The objective was to identify the causes of significant masonry decay. The ruined agricultural yard is a national cultural monument. Conservators believe that the historical importance exceeds that of the neighbouring castle. Stables were designed in 1650 by prominent Italian builders Giulio Broggio and Giovanni Domenico Orsi. The building has not been maintained since the conclusion of World War I. After removal from the masonry, the analyzed samples of bricks reached a very high, almost total degree of water saturation - 87-94%. Some bricks are heavily contaminated with nitrates and sulfates, infrared spectrometry analysis showed that calcium nitrate tetrahydrate is the most abundant of the nitrates. The determined average values of physical properties (bulk weight 1764 kg/m3, capillary absorption 13.6% by weight and open porosity 24% by volume) from samples under atmospheric pressure are comparable to the values of masonry bricks produced today. The results of the tests on the bricks from the Zákupy Castle stables construction demonstrate the high manufacturing quality of the masonry elements utilized. Based on the results of the analyses, it can be assumed that three degradation factors contribute to the observed damage to the bricks: high wetting of the masonry (almost total saturation of pores with water), which is most likely long-term lasting, frost cycles - repeated freezing and thawing of water in the bricks during the winter months, and repeated crystallization of water-soluble salts present in pores near the surface.
Constraining future surface air temperature change on the Tibetan Plateau
Authors: Wang Jianyu , Zhai Panmao , Zhou Baiquan , Li Chao , Chen Yang 
Published: July 2024

Abstract
The rapid warming of the Tibetan Plateau (TP) in recent decades has led to severe consequences, including the melting of glaciers and snow cover, which further accelerates warming. Accurately projecting the magnitude of future warming is crucial for effective climate change adaptation. However, the projection of future temperature change is model dependent. In this study, we demonstrate a significant correlation between the historical inter-model warming trend and future temperature change, suggesting this relationship could be used to calibrate the best estimate of projections and reduce the uncertainty by observations. For a high emission scenario, the constraint helps to narrow down the uncertainty range of annual and summer temperature change on the western TP by up to 2 °C and 4 °C, respectively, in the end of this century. The most substantial calibrated increase of future change is in winter by up to 2 °C, followed by autumn with an increase by about 1 °C. Discrepancies of historical warming trend among different observation datasets expose the largest impact on the constrained best estimate compared with emergent relationship derived from different climate models and warming trend in different historical periods.
Low-cost porous transport layers for water electrolysis cells with polymer electrolyte membranes
Authors: Wakayama Hiroaki 
Published: July 2024

Abstract
Proton exchange membrane (PEM) water electrolysis has advantages over other methods of producing green hydrogen such as its excellent response to power input fluctuations; wide operating range of current density; ease of production of high-pressure, high-purity hydrogen; and high durability. However, the conventional precious metal coatings used on the bipolar plates (BPPs) and porous transport layers (PTLs) of the PEM water electrolysis cell to prevent their oxidation are problematic because of their high cost; indeed, the BPPs and PTLs combined are the largest contributor (50%–70%) to the total cost of PEM water electrolysis stacks. Here, the Pt-coated PTL on the oxygen electrode side of a PEM water electrolysis cell was replaced with one with an alternative low-cost material coating (Ti4O7 or NiTiP), and the water electrolysis characteristics of the system were evaluated. We found that Ti4O7, but not NiTiP, functioned as a conductive, corrosion-resistant PTL coating in the PEM water electrolysis cell.