bluuebunny/crossref_metadata_2025 huggingface dataset:
Molecular-scale kinetic Monte Carlo simulation of pattern formation in photoresist materials for EUV nanolithography
Authors: Fernández Míguez L. , Bobbert P. A. , Coehoorn R.
Published: December 2024

A kinetic Monte Carlo (KMC) simulation tool for modeling the pattern formation process in photoresist materials for extreme ultraviolet (photon energy 92 eV) nanolithography is presented. The availability of such a tool should support the progress toward novel materials and experimental procedures that lead to an improved pattern resolution. The molecular-scale simulations describe the process in a stochastic and mechanistic manner and include the excitation of high-energy electrons upon light absorption, the creation of a charged-particle cloud, electron-induced chemical degradation of the photoresist molecules, the resulting bond formation between neighboring degraded molecules, and a chemical development step after which a pattern of the remaining non-dissolved molecules is obtained. The method is applied to the application-relevant class of Sn-oxocore photoresist materials and uses their known electronic structure and optical electron energy loss function. The validity of the approach is tested by comparing measured and simulated total electron yield spectra and photoelectron spectra. A demonstration of the method is given by calculating the dose and pitch dependent average shape and stochastic variability (line edge roughness) of line patterns that are obtained for rectangular and sine-wave illumination, assuming various scenarios that determine how molecular-scale degradation will lead to bond creation. We show how from these simulations the ultimate pattern resolution can be deduced. The findings are analyzed systematically using results of KMC simulations that reveal the size of the cloud of degraded molecules around a point of absorption (blur length) and that further reveal the sensitivity to uniform illumination (contrast curves), and using percolation theory. We find that KMC modeling captures the consequences of the strong gradients in the density of degraded molecules and of the stochasticity of the patterning process that simplified models do not include, leading to a significantly improved view of the final pattern quality.
Kinetic research and optimized particle size for high-performance of CdS NP photocatalyst
Authors: Wang Mengying , Xue Yongqiang , Du Jianping
Published: December 2024

Metal semiconductors are important materials for photocatalytic technology, and their morphology and size have the great influence on photocatalytic performance. Therefore, the detailed exploration of the size effect is significant for the photocatalytic reaction. Herein, CdS nanoparticles (NPs) with different particle sizes were prepared for photodegradation of methylene blue, and the effects of particle size on photodegradation were studied using CdS NPs as a catalyst. The rate-determining step of photodegradation is determined theoretically by deriving the kinetic order of the photodegradation reaction, and the relationships of size and performance are explored. The results show that the particle size of the CdS NP catalyst has an obvious influence on the photodegradation rate and the rate constant, and the size effects show a “volcano” trend, implying that the catalyst activity is best when the particle size of the catalyst is moderate. The size influences on the adsorption/desorption, light utilization, and carrier efficiency of the catalyst originate from the influence of size on the surface properties and energy band. This study provides a new understanding on the effect of catalyst size on its properties, and this finding of optimum sizes of catalyst possessing better activity is valuable, which has a significant guidance for developing high-performance catalytic materials.
Thermal characteristics of ghosting flame in coal mine dead-end roadway pool fires affected by fire locations
Authors: Wang Jingxin , Qu Baolin , Meng Yu , Zhao Chenguang , Yao Yongzheng , Wu Bing
Published: December 2024

As an important phenomenon in the evolution of fire, the ghosting flame exhibits dynamic and irregular behavior in environments with limited ventilation. By ghosting flame, we mean the phenomenon where the flame separates from the fuel surface under certain conditions. This study investigates the combustion characteristics of the ghosting flame in pool fires within a coal mine dead-end roadway by small-scale experiments. Results indicate that the ghosting flame appears more readily and earlier when the fire source is closer to the heading face or when the oil pan size is larger. Additionally, the fire source's location significantly influences the type of ghosting flame observed. When the fire source is near the heading face, the flame predominantly exhibits horizontal-type ghosting flame; however, when the fire source is at the entrance of the roadway, only the edge-type ghosting flame occurs. Furthermore, dead-end roadway fires easily transition to ventilation-controlled conditions, leading to a continuous increase in the mass loss rate. The occurrence of a ghosting flame does not result in a sudden change in the mass loss rate. Moreover, the transient oxygen volume fraction when the ghosting flame occurs is related to the ghosting flame type and is also affected by ventilation conditions, fuel types, roadway structure, and the location of measurement points. Importantly, the root cause for the occurrence of the ghosting flame lies in the pressure differential generated by the temperature disparity between the two sides of the fire source.
Understanding crystallization and amorphization in liquid Ti cooled at different rates: A molecular dynamics simulation study
Authors: Hazarika Manash Protim , Bordoloi Puja , Tripathi Ajay , Chakraborty Somendra Nath
Published: December 2024

Crystallization and amorphization are important processes and different cooling rates cause these transitions. Obtaining pure metals from their molten state is a challenge unless these two are well understood. Here we study both these transitions in liquid Ti using molecular dynamics simulations wherein Ti is modeled with embedded atom potential. At 1 bar, Ti crystal is melted and then cooled from 2200 to 300 K with cooling rates of 0.1, 1, and 10 K/ps. When cooled at 0.1 and 1 K/ps, molten Ti crystallizes to bcc phase between 1100 and 1000 K, and when cooled at 10 K/ps, it amorphizes between these temperatures. From radial distribution functions and Voronoi tessellation, we observe that liquid to bcc transition takes place through short range distorted hcp/bcc-like structures already present in it. Relaxation dynamics is studied using velocity-autocorrelation functions (VACFs), intermediate scattering function, and dynamic structure factor. For all cooling rates, relaxations in VACFs increase with cooling. However, correlations in them are stronger when the system is cooled at 10 K/ps. Relaxation times decrease and increase between 1100 and 1000 K for crystallization and amorphization, respectively, thereafter they increase again with further cooling. The dynamic structure factor shows stronger damping in thermal diffusive motion when systems are cooled at 0.1 and 1 K/ps and vibration peaks shift to higher frequencies when crystallization take place. Our findings support Binder’s [K. Binder, Proc. Natl. Acad. Sci. U. S. A. 111, 9374 (2014)] argument that if we cool the system faster than the minimum time needed for the liquid to relax, it will amorphize. This also prevents the growth of pre-ordered domains in it to establish long-range order.
Nonmetal-to-metal transition in liquid hydrogen using density functional theory and the Heyd–Scuseria–Ernzerhof exchange-correlation functional
Authors: Bergermann Armin , Kleindienst Lucas , Redmer Ronald
Published: December 2024

We investigate the first-order liquid–liquid phase transition in fluid hydrogen, which is accompanied by a nonmetal-to-metal transition. We use a combination of density functional theory for the electrons and molecular dynamics simulations for the ions. By employing the nonlocal Heyd–Scuseria–Ernzerhof exchange-correlation functional, we accurately determine the equation of state and the corresponding coexistence line. Additionally, we calculate the electrical conductivity using the Kubo–Greenwood formula and find jumps in the coexisting region, which is characteristic of a first-order transition. Our new predictions are compared with previous theoretical results and available experimental data. Thereby, we find that the strongly constrained and appropriately normed exchange-correlation functional provides an excellent balance between computational cost and accuracy.
Four-dimensional flow characteristics of air-entrained turbulent
impinging waterjet onto quiescent water surface
Authors: Ekwonu Michael Chukwuemeka , Park Sang Hwan , Kim Dong
Published: December 2024

This paper presents a time-resolved three-dimensional (4D) flow fields measurement of the continuous phase of a turbulent impinging jet inducing foam formation using the Lagrangian particle tracking velocimetry utilizing the Shake-The-Box algorithm. With the systems equipped with four high-speed cameras, time-series of images of fluid tracer particles were acquired. The Vortex-In-Sharp (VIC#) method was used to reconstruct the Eulerian flow fields of the particle tracks. The impinging jet was characterized as plume-like along the vertical direction with two distinct layers: developing shear and fully developed shear. The streamwise vortex structures of the continuous phase were influenced by the bubble plume motion, and the results showed high amplitude oscillations of the acceleration and deceleration near the jet source resulting in the formation of ring-like vortices, which break down as the jet moves downstream with its momentum dissipated. The flow of the continuous phase of impinging jet was self-similar both at the developed shear layer and the fully developed diffusion layer beneath the water pool and is characterized as homogeneous shear flow with anisotropy turbulence. The classical assumption of self-similarity with Gaussian profiles for continuous phase velocity is verified experimentally. We found that the results show a huge potential of blue energy harvesting from the low frequency (∼2 Hz) dissipating kinetic energy of the turbulent plume-like jet underneath the impinging water surface using triboelectric nanogenerator.
On dynamics of flash boiling bubbles within liquid ammonia systems
Authors: Yin Jiwen , Zhang Ren , Wang Lei , Lian Zifan , Wei Haiqiao , Pan Jiaying
Published: December 2024

It is crucially important to understand the dynamics of flash boiling bubbles of liquid fuels in order to achieve optimal fuel spray and mixing performance in realistic combustion engines. In this study, a modified pseudo-potential lattice Boltzmann method was adopted to capture the dynamics of flash boiling bubbles of liquid ammonia. The critical conditions for the flash boiling state of liquid ammonia were determined using isothermal depressurization techniques. Meanwhile, the evolutions of bubble clusters were investigated, allowing for bubble deformation, coalescence, and collapse in different flash boiling stages. The results show that the evolution of flash boiling bubble clusters presents two main stages, i.e., the early rapid expansion stage and the later slow expansion stage, and both stages are highly sensitive to temperature variations. Low-temperature environments can intensify the competition between bubble coalescence and collapse events, thereby changing the density, pressure, and velocity distribution and delaying the transition of bubbles to the eventual equilibrium state. In addition, the evolution of bubble clusters conforms to the Ostwald ripening mechanism, where large bubbles absorb smaller bubbles, promoting the formation and propagation of pressure waves in liquid ammonia. These pressure waves not only disturb the surrounding fluid to form vortices but also cause significant deformation of adjacent bubbles, thereby affecting the overall efficiency of flash boiling processes.
Combined experimental and computational investigation of the influence of micro vortex generator on incipient cavitation mode
Authors: Chen Jie , Guo Dongwei , Zhang Jiakun , Wang Yong , Liu Taotao , Wu Xian , Hu Changli
Published: December 2024

The objective of this paper is to investigate the effect of a passive control method on the incipient cavitation mode around a hydrofoil. Two micro vortex generators (mVGs) with different positions are installed on the leading edge (LE) of the NACA (National Advisory Committee for Aeronautics) 66 hydrofoil. The mVG-1 has the same structural parameters as the mVG-2, but it is closer to the LE of hydrofoil. A high-speed camera is used to record the transient behavior of the cavitating flow. The large eddy simulation combined with a mass transport model is applied to analyze the influence mechanism of mVG on the incipient cavitation mode. The results show that the three typical incipient cavitation modes are observed on the baseline hydrofoil, i.e., spot cavity, patch cavity, and finger cavity. The mVG induces the generation of vortex shaped like thin strips of fingers at its trailing edge, called the fingerlike vortex cavitation. The neighboring fingerlike vortices constitute a pair of counter-rotating vortices with equal sizes and opposite directions. It influences the near-wall flow state upstream and downstream of mVG and, thus, the incipient cavitation structure. For the mVG-1 hydrofoil, the fingerlike vortex cavitation is a unique form of the incipient cavitation mode, making the cavitation onset position fixed at the mVG tail. For the mVG-2 hydrofoil, the mVG has a significant effect on the incipient cavitation structure at small attack angles, changing both the incipient cavitation mode and position.
Flow field and performance analysis of downhole pipe string in single-well injection-production technology
Authors: Jiang Minghu , Li Xinya , Xing Lei , Zhao Lixin , Wang Fan , Chen Dingwei
Published: December 2024

High water content is a critical issue that must be urgently addressed in the current oilfield development, and the single-well injection-production technology (SWIPT) is an effective approach for achieving economical extraction in high-water-content oilfields. To meet the 5.5-inch casing size requirements, further improve SWIPT performance, and minimize the impact of pump pressurization on the subsequent oil–water separation process, dual-pump suction-SWIPT is proposed and an axial-flow cyclone separation pipe string is designed. A theoretical fluid–solid interaction (FSI) model of the downhole pipe string (DHPS) applicable to SWIPT is established through vibration testing and data analysis. Based on the new FSI model-corrected numerical simulation method, single-factor experiments are performed to analyze the medium transport process and oil–water separation performance within the flow field under structural vibration disturbances. The results indicate that the separation of fluid media within the single-well injection-production DHPS is not significantly affected by structural interference. The simulation results closely matched the experimental data, with the average error of the axial velocity at different test points being within 0.041 m/s. In the transport pipe regions, minor variations in the velocity and pressure fields are observed under vibration conditions. Under an inlet flow rate of 4 m3/h, split ratio of 30%, and oil volume fraction of 1%, the optimal separation efficiency of 97.26% is achieved. This study provides new insights for the development and application of SWIPT.
Imaging of tumor-associated macrophage dynamics during immunotherapy using a CD163-specific nanobody-based immunotracer
Authors: Lauwers Yoline , De Groof Timo W. M. , Vincke Cécile , Van Craenenbroeck Jolien , Jumapili Neema Ahishakiye , Barthelmess Romina Mora , Courtoy Guillaume , Waelput Wim , De Pauw Tessa , Raes Geert , Devoogdt Nick , Van Ginderachter Jo A.
Published: December 2024

Immunotherapies have emerged as an effective treatment option for immune-related diseases, such as cancer and inflammatory diseases. However, variations in patient responsiveness limit the broad applicability and success of these immunotherapies. Noninvasive whole-body imaging of the immune status of individual patients during immunotherapy could enable the prediction and monitoring of the patient’s response, resulting in more personalized treatments. In this study, we developed a nanobody-based immunotracer targeting CD163, a receptor specifically expressed on macrophages. This anti-CD163 immunotracer bound to human and mouse CD163 with high affinity and specificity without competing for ligand binding. Furthermore, the tracer showed no unwanted immune cell activation and was nonimmunogenic. Upon radiolabeling of the anti-CD163 immunotracer, specific imaging of CD163
+
macrophages using micro-single-photon emission computerized tomography/computed tomography or micro-positron emission tomography/CT was performed. The anti-CD163 immunotracer was able to stratify immunotherapy responders from nonresponders (NR) by visualizing differences in the intratumoral CD163
+
TAM distribution in Lewis lung carcinoma-ovalbumin tumor-bearing mice receiving an anti-programmed cell death protein-1 (PD-1)/CSF1R combination treatment. Immunotherapy-responding mice showed a more homogeneous distribution of the PET signal in the middle of the tumor, while CD163
+
TAMs were located at the tumor periphery in NR. As such, visualization of CD163
+
TAM distribution in the tumor microenvironment could allow a prediction or follow-up of therapy response. Altogether, this study describes an immunotracer, specific for CD163
+
macrophages, that allows same-day imaging and follow-up of these immune cells in the tumor microenvironment, providing a good basis for the prediction and follow-up of immunotherapy responses in cancer patients.
Corticosteroids reduce pathological angiogenesis yet compromise reparative vascular remodeling in a model of retinopathy
Authors: Hata Masayuki , Hata Maki , Dejda Agnieszka , Pilon Frédérique , Diaz-Marin Roberto , Fournier Frédérik , Joyal Jean-Sebastien , Cagnone Gael , Ochi Yotaro , Crespo-Garcia Sergio , Wilson Ariel M. , Sapieha Przemyslaw
Published: December 2024

Tissue inflammation is often broadly associated with cellular damage, yet sterile inflammation also plays critical roles in beneficial tissue remodeling. In the central nervous system, this is observed through a predominantly innate immune response in retinal vascular diseases such as age-related macular degeneration, diabetic retinopathy, and retinopathy of prematurity. Here, we set out to elucidate the dynamics of the immune response during progression and regression of pathological neovascularization in retinopathy. In a mouse model of oxygen-induced retinopathy, we report that dexamethasone, a broad-spectrum corticosteroid, suppresses initial formation of pathological preretinal neovascularization in early stages of disease, yet blunts reparative inflammation by impairing distinct myeloid cell populations, and hence reduces beneficial vascular remodeling in later stages of disease. Using genetic depletion of distinct components of the innate immune response, we demonstrate that CX3C chemokine receptor 1-expressing microglia contribute to angiogenesis. Conversely, myeloid cells expressing lysozyme 2 are recruited to sites of damaged blood vessels and pathological neovascularization where they partake in a reparative process that ultimately restores circulatory homeostasis to the retina. Hence, the Janus-faced properties of anti-inflammatory drugs should be considered, particularly in stages associated with persistent neovascularization.
Multi-sensor adaptive fusion and convolutional neural network-based acoustic emission diagnosis for initial damage of the engine
Authors: Han Cong , Liu Tong , Wang Yandong , Li Xin , Kou Ziming , Yang Guoan
Published: December 2024

Aiming at the problems of traditional fault diagnosis means that are difficult to identify initial damage, as well as the poor reliability and fault tolerance with a single sensor, an acoustic emission (AE) diagnosis method for initial damage of the engine based on multi-sensor adaptive fusion and convolutional neural network (CNN) is proposed. Firstly, under the premise of utilizing parametric analysis to characterize the multi-sensor AE signals, the feature parameter entropy is used to determine the primary and secondary relationships between multi-sensor signals, and then the AE feature parameter matrix is formed by adaptive fusion. Secondly, CNN is employed to mine and learn the fault feature combinations from the AE feature parameter matrix by multi-layer fusion to realize the identification and diagnosis for initial damage of the engine. Finally, the proposed method is validated on the engine test bench designed for initial damage identification and is compared with conventional methods in terms of diagnostic performance. The results demonstrate that the proposed method can achieve an identification accuracy of 98.83% for initial damage, and has advantages in various aspects such as TAMSE, K, F1mic and F1mac, which explicitly provides a theoretical and methodological basis for identifying initial faults comprehensively and accurately. This research not only enriches the theory and methods in the field of structural health monitoring, but also provides strong technical support for engine health management, which is expected to play a key role in the maintenance and guarantee of aviation engines in the future.
EDR-YOLOv8: a lightweight target detection model for UAV aerial photography using advanced feature fusion methods
Authors: Hao YongChang , Guo ChenXia , Yang RuiFeng , Zhao YuHui
Published: December 2024

Target detection from the aerial perspective of drones plays a crucial role in various fields. However, due to its unique high-altitude overhead view, images captured often exhibit a high proportion of small-sized targets amidst complex backgrounds and varying scales, posing significant challenges for detection. To address these issues, the EDR-YOLOv8 model has been proposed for drone-based aerial target detection. Firstly, the backbone of YOLOv8l is replaced with the high-resolution visual module EfficientViT, reducing the parameter count while maintaining the model’s capability to express important features. Secondly, the feature fusion network is redesigned with a four-level prediction layer to enhance the detection accuracy of small-sized targets. Additionally, the lightweight dynamic upsampler DySample is introduced to preserve more detailed target information. Finally, we design the feature fusion module C2f_RepGhost, which integrates the RepGhost bottleneck structure with YOLOv8’s C2f, thereby reducing computational complexity. Experimental results demonstrate that EDR-YOLOv8 achieves a 4.1% higher mAP@0.5 compared to the baseline YOLOv8l on the VisDrone2019-DET dataset, with a reduction of 40.5% in model size and 42.0% in parameter count. This illustrates that EDR-YOLOv8 achieves both lightweight modeling and improved detection accuracy.
Observation and characterisation of trapped electron modes in Wendelstein 7-X
Authors: Krämer-Flecken A , Proll J H E , Weir G , Costello P , Fuchert G , Geiger J , Heuraux S , Knieps A , Langenberg A , Vaz Mendes S , Pablant N , Pasch E , Rahbarnia K , Sabot R , Salazar L , Smith H M , Thomsen H , Windisch T , Xiang H M ,   the W7-X-team
Published: December 2024

In the past, quasi coherent (QC) modes were reported for nearly all tokamaks. The general definition describes modes as QC when the magnitude squared coherence is in the range of 0.3 to 0.6. QC modes are observed in the plasma core as well as in the plasma edge and can have quite different physical origins. The one in the core are observed in plasmas with low collisionality, where the electron temperature exceeds the ion temperature in the plasma core. This is the case for electron cyclotron heating in general. The origin of these modes are electrons trapped within a magnetic mirror, as reported in the past from various fusion devices. The so-called trapped-electron modes (TEMs) belong to drift wave instabilities and can be destabilized by electron-temperature gradients in the plasma core. From the diagnostic point of view, QC modes appear as fluctuations in electron density and temperature. Therefore, the microwave reflectometer is very well suited to monitor these modes. This paper describes experiments, conducted at the Wendelstein 7-X stellarator (W7-X), which aim at detecting QC modes at low wave numbers. A poloidal correlation reflectometer installed at W7-X, is able to measure low wave numbers (

k
⊥

⩽

3.5

cm

−
1

). For medium line-averaged densities (

∫

n
e

⩽

6
×

10

19

m

−
2

) the plasma core is accessible for this diagnostic. For different magnetic configurations and plasma parameters, broad QC structures are observed in the coherence spectra. From the analysis of the rotation and the poloidal structure, these QC modes show the properties of electron-temperature-gradient driven TEMs. A linear relation between the mode velocity and the rotation frequency is found. The relation is uniform and confirms the nature of QC-mode observation as TEM in tokamaks, too.
Particle-in-cell methods in edge plasma physics: the PICLS code
Authors: Bottino A , Stier A , Boesl M , Hayward-Schneider T , Bergmann A , Coster D , Brunner S , Giannatale G Di , Villard L
Published: December 2024

Over the past decades, multiple gyrokinetic codes have shown to be able to simulate turbulence and associated transport in the core of Tokamak devices. However, their application to the edge and scrape-off layer (SOL) region presents significant challenges. To date, only few codes and models have been adapted to SOL/edge conditions. To further study the SOL region in particular, with its steep temperature and density gradients as well as large fluctuation amplitudes, the full-f particle-in-cell code PICLS has been developed. PICLS is based on a full-f gyrokinetic model with linearized field equations, considers kinetic electrons and uses logical sheath boundary conditions. In the past, PICLS was verified by applying it to a well-studied 1D parallel transport problem during an edge-localized mode in the SOL under both collisionless and collisional conditions, for which a Lenard–Bernstein collision operator was implemented. PICLS recently was extended towards three spatial dimensions to study turbulence in open-field-line regions in slab and closed-field-line toroidal geometries. In this work, we will focus on the models and methods we used for extending the code towards three spatial dimensions, including validation efforts and comparisons with other existing codes in closed-field-line geometry.
Characterization of the SCR-1 stellarator physics: investigating plasma discharge, MHD equilibrium calculations, and O-X-B mode conversion feasibility
Authors: Solano-Piedra R , Vargas V I , Araya-Solano L A , Vilchez-Coto F
Published: December 2024

The Stellarator de Costa Rica 1 (SCR-1) is a small modular stellarator that serves as a valuable research and training tool for plasma magnetic confinement. This study aimed to analyze the characteristics of SCR-1, including its peripheral systems, technical plasma discharge processes, and advancements in plasma characterization. In addition, this study explored a new heating mechanism and the factors that influence it. The current state of the device and plasma discharge are initially presented. Subsequently, the measurement process was utilized to determine the electronic density and plasma temperature using a single Langmuir probe and the results were compared with theoretical predictions based on the particle and energy balance. Additionally, the VMEC code was employed to calculate magnetic flux surfaces with characteristics such as a low aspect ratio, low beta parameter, negative magnetic shear, and decreasing rotational transform along magnetic flux surfaces. The Mercier criterion was employed to conduct a linear stability analysis, which identified a magnetic well that played a crucial role in the linear stability of the majority of magnetic flux surfaces. Feasibility studies of electron Bernstein waves (EBW) were conducted using the IPF-FMDC full-wave code. The results obtained from the IPF-FMDC full-wave code revealed that the O-X conversion percentage reached a maximum of 63% when considering radiation reflection in the vacuum vessel. Significant effects of plasma curvature on the O-X wave conversion and normalized electron density scale length were observed, while the change in the SCR-1 heating position did not produce a significant impact. Three damping mechanisms affecting O-X conversion were studied, and one of the principal effects was the SX-FX conversion due to steep electron density gradient. Additionally, stochastic electron heating showed a low electron field amplitude, which is important for limiting the EBW propagation.
Influence of irradiation temperature on REBCO tape degradation
Authors: Fischer David X , Devitre Alexis Rustam , Woller Kevin Benjamin , Fisher Zoe L , Whyte Dennis G , Hartwig Zachary
Published: December 2024

Commercial Rare Earth Barium Copper Oxide (REBCO) coated conductor tapes were irradiated at temperatures ranging from 20 K to 300 K with 1.2 MeV protons up to fluences of 1021 m-2. With in situ transport current measurements, we found that self-field critical currents (Ic) and transition temperature (Tc ) degrade in cold (20-200 K) irradiations by a factor of 1.6 faster than in 300 K irradiations. This warrants caution when basing the development of REBCO fusion magnets, which are operated at 20 K, on results from room-temperature irradiations. The degradation of Ic , n-value and Tc for irradiations in the range 20-200 K closely matched each other. However, small annealing effects can already be observed at 80 K, which is a lower threshold than previously thought. The observed Ic recovery increases with annealing temperature and is at 300 K four times higher than at 200 K. And finally, we compared the experimental data from this study with the calculated decrease of superfluid density, and find a surprisingly good correlation, supporting the Eisterer hypothesis for Ic degradation.
Thickness effect on the evolution of superconducting properties in FeSe0.4Te0.6 thin films
Authors: Zhu Yunrui , Zhang Yalin , Li Bin , Liu Jinxiang , Cheng Jie , Liu Shengli , Xing Zhongwen
Published: December 2024

A series of high-quality FeSe0.4Te0.6 epitaxial thin films with different thicknesses were fabricated on CaF2 substrates by pulsed laser deposition. With increasing the film thickness, the superconducting transition temperature is enhanced rapidly but deteriorates gradually in over thick films. The superconducting transition occurs in all films including the 5 nm one, and T
c above 21 K persists in the films with thicknesses from 45 to 180 nm. We find that T
c and the c-axis lattice constant show a nearly linear correlation, suggesting a strong interdependence between T
c and the lattice strain characteristics. The upper critical field, anisotropy and effective pinning energy are studied in detail for the 15, 60, 90 and 180 nm films. These observations provide key insights in understanding the thickness effect on the superconductivity of the FeSe0.4Te0.6 films.
Study on Impact Load Mitigation for High-Speed Water Entry Projectiles Using Aluminum Foam Buffering Structure
Authors: Guo Xiangying , Tian Xiangyu , Nan Tian
Published: December 2024

This paper investigated the fluid-solid coupling nonlinear problem of water entry by a high-speed projectile, considering cavitation, air cushion effect, and water vapor generated by the high-speed relative motion between the projectile and the fluid. To this end, a sandwich structure containing aluminum foam attached piston was studied and designed. The numerical simulation of the entry process was analyzed by LS-DYNA. The results show that the sandwich structure reduces the peak impact load. 87.47% reduction in peak force during water entry and aluminum foam has good cushioning effect.
Analysis of the Goodwin business cycle model with discrete delay and distributed delay in induced investment
Authors: Antonova A.O.
Published: December 2024

In this paper, a Goodwin model of business cycle with both discrete and distributed delays is considered. With the corresponding characteristic equation analyzed, the linear stability of the equilibrium is investigated. Numerical simulations are carried out to study the excitation conditions of the long-periodic Goodwin oscillations.
Group Classification and Numerical Study of Gross-Pitaevskii Systems
Authors: Bozhkov Yuri , Dimas Stylianos , Todorov Michail
Published: December 2024

We carry out a preliminary group classification for the 3+1 Gross-Pitaevskii system and the complete group classification for the 1 + 1 integrable component of the Gross-Pitaevskii system. For the exceptional potentials that the group classification sheds light a numerical study was performed.
On the Power Series Method for Solitons and Peakons of Nonlinear PDE
Authors: Olivares Erika , Vatchev Vesselin
Published: December 2024

In this paper we discuss the power series method to obtain traveling wave solutions of nonlinear PDE in one space variable. The method, including a recursive procedure for the coefficients and error estimate for the partial sums, is presented for the Camassa-Holm equation. Numerical examples of approximate single soliton and single peakon solutions are included.
The Effect of Climate Change on Coastal Morphology Changes in Lhokseumawe City Area
Authors: Hafli T Mudi , Fauzan M , Bustami  , Malasyi Syibral , Sarana David , Cahya Fran
Published: December 2024

The city of Lhokseumawe in Aceh is mostly located on the coast and is vulnerable to annual tidal waves, causing coastal settlements to sink. The rising sea levels in Indonesia, as observed by the IPCC using the TOPEX/POSEIDEN satellite, have reached 7 mm/year. A study was conducted to assess the impact of tidal waves exacerbated by sea level rise on changes in coastal morphology over 25 and 50 years. The study utilized the Delft3D numerical simulation method with various input data such as Topographic Data, bathymetry, tides, discharge, sediment, and waves. The results of the Delft3D modeling showed that erosion is slightly greater in the 25 and 50-year scenarios, with an average minimum erosion of about 12 m and a maximum erosion and retreat of about 18 m. However, in the 50-year scenario, there were points along the coast where sedimentation occurred, leading to the advancement of the coastline by about 36 m. These dynamic morphological changes in the coastal area of Lhokseumawe highlight the need for a coastal protection plan to address this vulnerability.
Public Space Quality Analysis of Putroe Phang Park in Banda Aceh City
Authors: Amri Khairul , Fuady Mirza
Published: December 2024

Green open space in the form of a city park is one of the important urban infrastructures because it not only functions in terms of ecology, aesthetics, and urban identity but also plays a role in increasing people’s happiness. Putroe Phang Park is a public open space located in the center of the city and adjacent to several other tourist attractions that are often visited by the public. Putroe Phang Park is also a city park with historical value in the glory era of the Aceh Sultanate. However, the public rarely visits Putroe Phang Park to enjoy recreation in the park. Therefore, further studies are needed to analyze the quality and usage of Putroe Phang Park as a public open space in accommodating community activities. The research method used is descriptive quantitative, with democratic, responsive, and meaningful variables, which are used to analyze the quality and usage of parks as public open spaces. The results of the study show that the conditions and factors that affect the low intensity of visitors are the unsuitability of facilities, lack of security level, and lack of education about the Pinto Khop Monument as a historical site. These results show the low value of meaningful impressions felt by visitors to Putroe Phang Park. For this reason, this study recommends increasing the quality and usage of Putroe Phang Park as a public open space by periodically updating and maintaining the existing facilities and complementing other park-supporting facilities.
Flexural strength of end-plate connection with several different bolt arrangements
Authors: Panjaitan Arief , Hasibuan Purwandy , Putra Rudiansyah , Afifuddin Mochammad , Fauzi Muhammad , Haiqal Muhammad
Published: December 2024

An end-plate connection is one of the common connections implemented in beam-column joints. This connection used a combination of bolts and welds as the connectors, so it is also specified as a semi-rigid connection. In general, the end-plate connection is applied to withstand the bending moment and to enhance its bending capacity, the connection area of the end-plate is generally enlarged. So far, the studies carried out to obtain the contribution of bolt arrangements to flexural strength are very limited, so maximum flexural capacity has not yet been optimally achieved. This research aims to examine the flexural strength of end-plate connections varied by bolt arrangements and bolt connection areas. The study was first conducted by analytically modeling the end-plate connection in SAP 2000, where the internal forces, i.e., shear force and moment were obtained from this numerical study. The theoretical studies were also carried out by considering internal troops to discover the influence of the bolt configuration on the end-plate connection to the flexural strength. The height of the area connection was also assorted, i.e., 100 mm, 200 mm, and 300 mm. The study revealed that enlarging area connections and increasing the number of bolts, reduce the tensile and shear stress at the maximum rate of 97.6 and 50 %, respectively. However, it can increase the flexural strength up to the rate 15 times from the minimum flexural strength. This result revealed that enlarging the connection area and adding the number of bolts can be suggested to enhance the flexural capacity when the end plate connection deals with a strong bending moment.
Using Multichannel Analysis of Surface Wave to Assess Bedrock Depth in Grand Aceh Baet Residential Area
Authors: Masrurah Zakia , Mufadhillah Putri Aulia , Adianur Rahiel , Mohammed Mustapha Adejo , Amsir Amsir
Published: December 2024

Inadequate foundation studies had over time led to quite a number of mishaps, resulting in loss of lives and properties. To address this issue, a Multichannel Analysis of Surface Wave (MASW) survey was conducted at the proposed Grand Aceh Housing site to characterize the subsurface and determine the depth to the bedrock, ensuring a stable foundation for the Rusunawa construction. The survey was performed along four profile lines using a PASI 16S-24P seismograph. The acquired data were processed with Geopsypack Geopsy and Dinver version 2.5.0 and then modelled into 2D data using Surfer version 13. The results identified four distinct layers with varying depths and thicknesses: the first layer with shear wave velocity ≤175 m/s is classified as soft soil layer (SE), the second layer as medium soil (SD) with Vs 175-350 m/s, the third layer as solid soil and soft rock (SC) with Vs 350-750 m/s, and the fourth layer as rock layer (SB) with Vs 750-1200 m/s. The findings of this study suggest that the fourth layer is bedrock, capable of supporting the Rusunawa foundation.
Vulnerability Study of Existing Office Building Before and After Rehabilitation Using Fragility Curve
Authors: Asri Luthfi Ainy , Masrilayanti  , Kurniawan Ruddy , Setiati Rehni , Pratama Ardi
Published: December 2024

Padang, located in West Sumatra, is an earthquake-prone area, with a major event occurring in 2009 that damaged many important buildings. An existing building was impacted by the earthquake, resulting in cracks and other damages. Subsequently, the building was rehabilitated to enhance its structural strength through jacketing. This study compares the building’s fragility curves before and after rehabilitation using the HAZUS standard and licensed Seismostruct software. The results show that, prior to rehabilitation, the building was vulnerable to damage due to earthquake. After rehabilitation, the structural strength improved more significantly, reducing damage levels from moderate to minor. Given the high seismic risk in Padang, it is crucial that building structures are designed with optimal resilience. The development of an analytical fragility curve is proposed for a more in-depth evaluation of building performance against future earthquakes, facilitating the identification of damage levels and enabling timely preventive and corrective measures.
Effect of ureolytic bacteria Bacillus sp. from local landfill for crack healing on flexural tensile strength of high-strength concrete
Authors: Aulia Teuku Budi , Fitri Lenni , Tanjung Jafril , Jalil Zulkarnain , Handoko Erfan , Badjie Mariama
Published: December 2024

High-strength concrete made with large amount of cement augmented with additives causing high hydration heat and large shrinkage during hardening process, making it susceptible to cracks at early age due to its still low tensile capacity. These cracks must be mitigated early. Self-healing method using ureolytic bacteria Bacillus sp. as concrete crack-healing can be smart solution to overcome this problem. Urease enzyme produced by ureolytic bacteria can hydrolyze urea and Ca2+ (derived from CaCl2) added as precursors to precipitate CaCO3 as concrete cracks closure biologically. This study aims to analyze effect of ureolytic bacteria Bacillus sp. cultivated from local landfill Gampong Jawa, Banda Aceh as crack self-healing on flexural tensile strength of high-strength concrete. Bacteria were immobilized into diatomaceous earth to increase viability during casting and after residing in harsh environment of concrete which used as 10% substitution for fine aggregates. Concentration of bacteria and growth media used were varied by 0%; 0.5%; 0.6%; and 0.7% of cement weight. Specimens were beams measuring 100×100×400mm which was given 1D10 mm tensile reinforcement to prevent brittle failure during testing. First, an initial crack load of 60% of 7 days concrete flexural tensile strength was given, then treatment was carried out for 28 days in water to observe crack healing for 7, 14, 21 and 28 days. After completing crack healing phase, flexural tensile capacity testing was carried out until the specimens collapsed. The results showed that flexural tensile capacity of high-strength concretes was 5.49 ton, 5.69 ton, 5.89 ton and 5.86 ton respectively and the percentage of concrete crack closure after healing phase for 28 days after being initially cracked was 4.76%; 77.90%; 87.09%; and 89.09% each, at variations of Bacillus sp. 0.0%; 0.5%; 0.6%; and 0.7%. Optimum value was obtained at bacterial percentage of 0.7% resulting in an increase both in flexural tensile capacity of 6.74% and in crack healing efficacy of 84.27% compared to non-bacteria concrete.
Modelling the hydraulic performance of an array of centrifugal pumps operating under a variable pressure in a hydro-pneumatic energy storage system
Authors: Cassar Andrea , Sant Tonio , Borg Andrew
Published: December 2024

The large pressure variation in hydro-pneumatic energy storage systems presents a major challenge for maintaining a high operating efficiency of the turbomachinery used in the hydro-electric energy conversion processes. This paper applies numerical modelling to compare the hydraulic performance of two pumping unit variants used for charging an offshore hydro-pneumatic energy storage (HPES) accumulator. The first unit consists of a single large centrifugal pump operated at variable speed while the second pumping unit is made up of an array of smaller, dynamically similar fixed-speed pumps. A number of series/parallel configurations for the latter option were derived in order to optimise the operational efficiency at various states of charge of a gas-charged accumulator, specifically between 80 and 200 bar. A comparative analysis of the operational hydraulic efficiencies for both pumping units shows that using an array of small fixed-speed pumps arranged in series/parallel configurations is more energy efficient than using a single large pump operated at variable speed.
Optimal Global Gravity Field Model for Calculation of local Gravity and Geoid in Indonesia
Authors: Ramdani Dadan , Pahlevi Arsauna , Muthia Harahap Rina
Published: December 2024

This study assesses the accuracy and reliability of 17 Global Gravity Models (GGMs) sourced from ICGEM for geoid and gravity anomaly calculations. Using 980 validation points for geoid calculations and 18 for gravity anomaly calculations, we evaluated the standard deviations of each GGM to determine their precision. The results indicate that the three GGMs with the lowest standard deviations for geoid calculations are SGG-UGM-2 (0.247 m), XGM2019e 2159 (0.205 m), and EGM2008 (0.191 m), while SGG-UGM-1 G exhibited the highest deviation at 10.711 m. For gravity anomaly calculations, XGM2019e 2159 (15.295 mGal), EGM2008 (14.517 mGal), and SGG-UGM-2 (14.396 mGal) demonstrated the highest accuracy. The findings underscore the importance of selecting appropriate GGMs for precise geodetic applications, with models like EGM2008 and XGM2019e 2159 offering superior performance due to their low standard deviations and high reliability. The spatial distribution of validation points further highlights the need for comprehensive evaluation across varied regions and terrains. This study provides critical insights for geodesists in choosing the most suitable GGMs for accurate geodetic results.
Assessing Multi-Hazard Risk through Spatial Analysis: A Geographic Information Systems for Susceptibility Mapping in Java Island, Indonesia
Authors: Meilano I , Virtriana R , Widyastuti R , Salim Z L , Lunardia H R , Arum F S , Maharani K A , Lendra N D
Published: December 2024

The geographic location and population make Java Island a disaster-prone area with various threats, including earthquakes, floods, landslides, and volcanic eruptions. Based on historical data, these four types of disasters caused a total of US$24,303,159,688 in economic losses in the last 50 years. In regard to the big loss, it is considered important to identify potential disaster risks to avoid more sustainable economic losses in the future. By utilizing developments in Geographic Information Systems (GIS) technology, potential disaster risk mapping could be carried out. The process begins with preparing a map of the potential risk of earthquakes, floods, landslides, and volcanic eruptions by referring to the regulatory document of the head of the National Disaster Management Agency (BNPB) Number 2 of 2012 and Indonesian National Standard (SNI). Afterwards, the potential risk map for each type of disaster will be combined to determine the hazard level of each disaster in 1 square kilometer-sized pixels. The merging process uses annual economic loss data over a period of 50 years as a weighting factor. Based on the data, the results show that 11.554% (15.092 square kilometers) of the area of Java Island falls into the high hazard level class, 77.642% (101.413 square kilometers) into the moderate hazard level class, and 10.804% (14.112 square kilometers) into the low hazard level class. The resulting multi-hazard map could be further used for various specific purposes, such as creating an early warning system or estimating direct losses due to disasters.