bluuebunny/crossref_metadata_2025 huggingface dataset:
Vibration-induced wall–bubble interactions under zero-gravity conditions
Authors: Lyubimov D.V. , Lyubimova T.P. , Meradji S. , Roux B.
Published: August 2024

This work is devoted to a theoretical and numerical study of the dynamics of a two-phase system vapour bubble in equilibrium with its liquid phase under translational vibrations in the absence of gravity. The bubble is initially located in the container centre. The liquid and vapour phases are considered as viscous and incompressible. Analysis focuses on the vibrational conditions used in experiments with the two-phase system SF

$_6$

in the MIR space station and with the two-phase system para-Hydrogen (p-H

$_2$

) under magnetic compensation of Earth's gravity. These conditions correspond to small-amplitude high-frequency vibrations. Under vibrations, additionally to the forced oscillations, an average displacement of the bubble to the wall is observed due to an average vibrational attraction force related to the Bernoulli effect. Vibrational conditions for SF

$_6$

correspond to much smaller average vibrational force (weak vibrations) than for p-H

$_2$

(strong vibrations). For weak vibrations, the role of the initial vibration phase is crucial. The difference in the behaviour at different initial phases is explained using a simple mechanical model. For strong vibrations, the average displacement to the wall stops when the bubble reaches a quasi-equilibrium position where the resulting average force is zero. At large vibration velocity amplitudes this position is near the wall where the bubble performs only forced oscillations. At moderate vibration velocity amplitudes the bubble average displacement stops at a finite distance from the wall, then large-scale damped oscillations around this position accompanied by forced oscillations are observed. Bubble shape oscillations and the parametric resonance of forced oscillations are also studied.
Non-universality and dissipative anomaly in compressible magnetohydrodynamic turbulence
Authors: Li Cheng , Yang Yan , Matthaeus William H. , Jiang Bin , Wan Minping , Chen Shiyi
Published: August 2024

We systematically study the dissipative anomaly in compressible magnetohydrodynamic (MHD) turbulence using direct numerical simulations, and show that the total dissipation remains finite as viscosity diminishes. The dimensionless dissipation rate

$\mathcal {C}_{\varepsilon }$

fits well with the model

$\mathcal {C}_{\varepsilon } = \mathcal {C}_{\varepsilon,\infty } + \mathcal {D}/R_L^-$

for all levels of flow compressibility considered here, where

$R_L^-$

is the generalized large-scale Reynolds number. The asymptotic value

$\mathcal {C}_{\varepsilon,\infty }$

describes the total energy transfer flux, and decreases with increase of the flow compressibility, indicating non-universality of the dimensionless dissipation rate in compressible MHD turbulence. After introducing an empirically modified dissipation rate, the data from compressible cases collapse to a form similar to the incompressible MHD case depending only on the modified Reynolds number.
Time‐Resolved Trigger Processes Leading to the Plinian Eruptions at Sakurajima Volcano, Japan
Authors: Araya Naoki , Nakamura Michihiko , Matsumoto Keiko , Okumura Satoshi
Published: August 2024

Mafic magma recharge of crustal reservoirs and subsequent magma mixing has been considered a direct trigger of volcanic eruptions. However, although recharge frequently occurs in many active volcanoes, it rarely leads to an eruption immediately, making its role as a trigger ambiguous. Sakurajima volcano, Japan, has vigorously erupted three times since the 15th century following a common process; mixed magmas after recharge were once stored in a shallow, thick conduit before each eruption (conduit pre‐charge). We reconstructed the magma migration with a high time resolution by diffusion modeling on orthopyroxene and magnetite. Orthopyroxene phenocrysts recorded prolonged diffusive re‐equilibration timescales of years or more after recharge‐and‐mixing. Magnetite, which has the fastest elemental diffusivity among the phenocrysts examined, predominantly lacks zoning. This demonstrates that the mineral phase was re‐equilibrated with surrounding magma and homogenized via elemental diffusion after the final magmatic perturbation, implying the final repose of the shallow pre‐charged magma body for more than several tens of days. After this shallow stagnation period, the Plinian magmas began to ascend and reached the surface within 55 hr. Mass balance calculations show that crystallization‐driven vesiculation upon pre‐charge can produce overpressure sufficient to cause an eruption. The Sakurajima cases demonstrate the hierarchical timescales of trigger processes leading to the explosive eruptions.
Traveling Light: Arctic Coastal Erosion Releases Mostly Matrix Free, Unprotected Organic Carbon
Authors: van Crimpen F. C. J. , Madaj L. , Whalen D. , Tesi T. , van Genuchten J. M. , Bröder L. , Eglinton T. I. , Haghipour N. , Vonk J. E.
Published: August 2024

The Arctic rapidly warms and sea ice retreats, a large fraction of organic carbon (OC), currently stored in coastal permafrost will be released into the marine system. Once reintroduced into the active carbon cycle, this material will either be decomposed or buried on the shelf depending on its hydrodynamic and chemical properties. Currently, carbon estimates are based on bulk measurements, which does not take the hydrodynamic pathway of different fractions into account. Therefore, eight coastal permafrost locations have been sampled along the Canadian Beaufort Sea Coast, hydrodynamically fractionated and analyzed for their C, N, 13C and 14C content. We found that the matrix‐free fraction (low density <1.8 g/cm3, and high‐density >1.8 g/cm3; <38 μm) account for 77%–98% of the OC. By using a coastal classification combined with field data, our results showed that short coastal segments can become key players in delivering matrix‐free, easily degradable OC to the marine system.
A Mechanistic Study of Inverse Temperature Layer of Water Bodies
Authors: Jing Weiqiang , Wang Jingfeng , Liu Heping , Shen Lian , Zhu Modi
Published: August 2024

The inverse temperature layer (ITL) beneath water‐atmosphere interface within which temperature increases with depth has been observed from measurement of water temperature profile at an inland lake. Strong solar radiation combined with moderate wind‐driven near‐surface turbulence leads to the formation of a pronounced diurnal cycle of the ITL predicted by a physical heat transfer model. The ITL only forms during daytime when solar radiation intensity exceeds a threshold while consistently occurs during nighttime. The largest depth of the ITL is comparable to the e‐fold penetration depth of solar radiation during daytime and at least one order of magnitude deeper during nighttime. The dynamics of the ITL depth variation simulated by a physical model forced by observed water surface solar radiation and temperature is confirmed by the observed water temperature profile in the lake.
Ozone‐Depleting Substances Unintendedly Emitted From Iron and Steel Industry: CFCs, HCFCs, Halons and Halogenated Very Short‐Lived Substances
Authors: Liu Yuzhe , Weng Wenbin , Zhang Qi , Li Qing , Xu Jiaying , Zheng Lixin , Su Yi , Wu Di , Yan Weizhuo , Zhang Jie , Chen Jianmin , Yao Bo
Published: August 2024

Ozone‐depleting substances (ODSs) are well known as primary emission from the production and consumption of traditional industrial sectors. Here, we reported the unintentional emission of ODSs from iron and steel plants as a new source, basing on real‐world measurements of flue gases emitted from their major processes. The sintering was found to be the major emission process of ODSs, including chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), halons, methyl halide (CH3Cl), methyl chloroform, carbon tetrachloride, methyl bromide and halogenated very short‐lived substances. The median emission factors of CFC‐113, CFC‐115, HCFC‐22, and CH3Cl for typical sintering processes are 1.7, 0.7, 44.5 and 237.0 mg/t, respectively. Quantum chemical calculation figures out that the ODS species are mainly formed in the low efficiency combustion process of halogenated materials. Annual amounts of ODS and CFC‐11‐equivalent emissions were estimated to be 1,785 tons and 78 tons in 2019 over mainland China, respectively. Given these findings, this study provides a new prospective on searching for ODS emission sources, especially unintentional sources such as iron and steel industry and other combustion related activities.
Neutralizing and binding antibody responses to SARS-CoV-2 with hybrid immunity in pregnancy
Authors: Li Lin , Matsui Yusuke , Prahl Mary K. , Cassidy Arianna G. , Golan Yarden , Jigmeddagva Unurzul , Ozarslan Nida , Lin Christine Y. , Buarpung Sirirak , Gonzalez Veronica J. , Chidboy Megan A. , Basilio Emilia , Lynch Kara L. , Song Dongli , Jegatheesan Priya , Rai Daljeet S. , Govindaswami Balaji , Needens Jordan , Rincon Monica , Myatt Leslie , Taha Taha Y. , Montano Mauricio , Ott Melanie , Greene Warner C. , Gaw Stephanie L.
Published: August 2024

Hybrid immunity against SARS-CoV-2 has not been well studied in pregnancy. We conducted a comprehensive analysis of neutralizing antibodies (nAb) and binding antibodies in pregnant individuals who received mRNA vaccination, natural infection, or both. A third vaccine dose augmented nAb levels compared to the two-dose regimen or natural infection alone; this effect was more pronounced in hybrid immunity. There was reduced anti-Omicron nAb, but the maternal-fetal transfer efficiency remained comparable to that of other variants. Vaccine-induced nAbs were transferred more efficiently than infection-induced nAbs. Anti-spike receptor binding domain (RBD) IgG was associated with nAb against wild-type (Wuhan-Hu-1) following breakthrough infection. Both vaccination and infection-induced anti-RBD IgA, which was more durable than anti-nucleocapsid IgA. IgA response was attenuated in pregnancy compared to non-pregnant controls. These data provide additional evidence of augmentation of humoral immune responses in hybrid immunity in pregnancy.
GloRESatE: A dataset for global rainfall erosivity derived from multi-source data
Authors: Das Subhankar , Jain Manoj Kumar , Gupta Vivek , McGehee Ryan P. , Yin Shuiqing , de Mello Carlos Rogerio , Azari Mahmood , Borrelli Pasquale , Panagos Panos
Published: August 2024

Numerous hydrological applications, such as soil erosion estimation, water resource management, and rain driven damage assessment, demand accurate and reliable rainfall erosivity data. However, the scarcity of gauge rainfall records and the inherent uncertainty in satellite and reanalysis-based rainfall datasets limit rainfall erosivity assessment globally. Here, we present a new global rainfall erosivity dataset (0.1° × 0.1° spatial resolution) integrating satellite (CMORPH and IMERG) and reanalysis (ERA5-Land) derived rainfall erosivity estimates with gauge rainfall erosivity observations collected from approximately 6,200 locations across the globe. We used a machine learning-based Gaussian Process Regression (GPR) model to assimilate multi-source rainfall erosivity estimates alongside geoclimatic covariates to prepare a unified high-resolution mean annual rainfall erosivity product. It has been shown that the proposed rainfall erosivity product performs well during cross-validation with gauge records and inter-comparison with the existing global rainfall erosivity datasets. Furthermore, this dataset offers a new global rainfall erosivity perspective, addressing the limitations of existing datasets and facilitating large-scale hydrological modelling and soil erosion assessments.
Neural shape completion for personalized Maxillofacial surgery
Authors: Mazzocchetti Stefano , Spezialetti Riccardo , Bevini Mirko , Badiali Giovanni , Lisanti Giuseppe , Salti Samuele , Di Stefano Luigi
Published: August 2024

In this paper, we investigate the effectiveness of shape completion neural networks as clinical aids in maxillofacial surgery planning. We present a pipeline to apply shape completion networks to automatically reconstruct complete eumorphic 3D meshes starting from a partial input mesh, easily obtained from CT data routinely acquired for surgery planning. Most of the existing works introduced solutions to aid the design of implants for cranioplasty, i.e. all the defects are located in the neurocranium. In this work, we focus on reconstructing defects localized on both neurocranium and splanchnocranium. To this end, we introduce a new dataset, specifically designed for this task, derived from publicly available CT scans and subjected to a comprehensive pre-processing procedure. All the scans in the dataset have been manually cleaned and aligned to a common reference system. In addition, we devised a pre-processing stage to automatically extract point clouds from the scans and enrich them with virtual defects. We experimentally compare several state-of-the-art point cloud completion networks and identify the two most promising models. Finally, expert surgeons evaluated the best-performing network on a clinical case. Our results show how casting the creation of personalized implants as a problem of shape completion is a promising approach for automatizing this complex task.
An innovative deformation coordination method for analyzing distortion effects on box girders
Authors: Wang Chenguang , Shi Mingxin , Huang Jianqiang , Zhang Yuanhai , Li Weiwen , Mansour Walid , Ke Linyuwen , Wang Peng
Published: August 2024

A deformation coordination method is proposed in this study to account for the distortion effects on a box girder. The differential equation for distortion in vertical web box girders is derived based on the deformation coordination condition of the distortion angle, considering both external loads and internal forces. Subsequently, a comparative analysis is conducted to explore the similarities and differences between the differential equations derived from the proposed deformation coordination method, the plate element analysis method and the total potential energy variation method. The accuracy of the proposed approach is verified through bench-scale tests and numerical simulations. The findings indicate that the derived governing distortion differential equation and distortion attenuation coefficients in the proposed method align with those obtained from the plate element analysis method and the total potential energy variational method, which enhances the applicability to allow for the distortion equations to be obtained simply by calculating the distortion displacements. The analytical findings regarding the distortion warping normal stresses on the cross-sections of the box girders demonstrate favorable correspondence with the experimental results, displaying an acceptable error ranging from − 0.3% to 5.4%. Moreover, the peak of distortion warping normal stresses on the mid-span cross-section increases with higher span-to-depth ratios and height-to-thickness ratios of the web. Consequently, augmenting the thickness of the box wall proves to be an effective means of reducing the distortion effect in box girders.
Conceptional design for a universal HVDC-HVAC vacuum-interrupter-based circuit breaker
Authors: Wadie Fady , Eliyan Tamer
Published: August 2024

Modern power systems high voltage transmission systems either HVDC or HVAC has mandated the presence of two types of circuit breakers (CB), HVAC-CB and HVDC-CB. That required two different production lines, higher costs and more complicated manufacturing process. A solution is proposed in this paper which is a concept design for a universal HVCB (UHVCB) that is applicable to both HVDC and HVAC system. Such a concept would allow a faster, easier production and more economical unit cost for CBs that would benefit the entire industry from manufacturers to utilities. The design of HVDC-CB was used as the foundation the proposed UHVCB such that L–C branches are used. The UHVCB was tested in both HVAC and HVDC transmission systems. The results showed the reliable performance of UHVCB in both systems. The recorded transient recovery voltage (TRV) was reduced from 750 to 430 kV when UHVCB was used instead of conventional HVCB. The testing included both technical and economic aspects. The performance of the UHVCB was tested by varying the parameters for L–C shunt branches in both systems. That included varying the value of L in range 0.3–1 mH and 10–30 µF for C. The most important conclusion from this paper that a UHVCB that is applicable in HVDC and HVAC systems is achievable and this paper is only an initial step in achieving this goal.
Stachydrine, a pyrrole alkaloid with promising therapeutic potential against metabolic syndrome and associated organ dysfunction
Authors: Ahmed Semim Akhtar , Manna Prasenjit , Borah Jagat Chandra
Published: August 2024

Metabolic syndrome is a multifaceted condition marked by interconnected risk factors, significantly increasing the risk of serious diseases like cardiovascular disease, type 2 diabetes, and stroke.
Novel high-efficiency near-infrared phosphor CaZrTaGaO7:Cr3+ and its application in night vision and anti-counterfeiting
Authors: Meng Xue , Wang Zhijun , Huo Xiaoxue , Zhou Mingxin , Wang Yu , Li Panlai
Published: August 2024

NIR phosphor CaZrTaGaO7:Cr3+ shows high internal quantum efficiency (IQE: 90.7%) and high thermal stability (84.8% at 423 K), enabling it for application in night vision, anti-counterfeiting, etc.
Visible-light-induced copper-catalyzed regiodivergent C(sp3)-sulfonylation of oxime esters with sodium sulfinates
Authors: Ma Ben , Chen Zhiyong , Ma Min , Zhao Zheng , Long Yun'e , Chen Dongping , Yang Jingya
Published: August 2024

A visible-light-induced copper-catalyzed regiodivergent sulfonylation of oxime esters with sodium sulfinates under mild conditions is reported, yielding a range of useful β-ketosulfones and sulfonated pyrrolines with convertible functional groups.
Decatungstate-photocatalyzed radical addition of C(sp3)–H to azauracils
Authors: Qiao Lipeng , Yang Wumeng , Zhao Xiangqian , Li Erqing , Chen Xiaolan , Qu Lingbo , Yu Bing
Published: August 2024

This study presents a gentle and effective decatungstate ([W10O32]4−)-photocatalyzed method for the hydroalkylation of azauracils using a wide range of primary, secondary, and tertiary unreactive C–H bonds of alkanes as the alkylating reagents.
Filamin A regulates platelet shape change and contractile force generation via phosphorylation of the myosin light chain
Authors: Hong Felix , Mollica Molly Y , Golla Kalyan , De Silva Enoli , Sniadecki Nathan J , López José A , Kim Hugh
Published: August 2024

Platelets are critical mediators of hemostasis and thrombosis. Platelets circulate as discs in their resting form but change shape rapidly upon activation by vascular damage and/or soluble agonists such as thrombin. Platelet shape change is driven by a dynamic remodeling of the actin cytoskeleton. Actin filaments interact with the protein myosin, which is phosphorylated on the myosin light chain (MLC) upon platelet activation. Actin-myosin interactions trigger contraction of the actin cytoskeleton, which drives platelet spreading and contractile force generation. Filamin A (FLNA) is an actin-crosslinking protein that stabilizes the attachment between subcortical actin filaments and the cell membrane. In addition, FLNA binds multiple proteins and serves as a critical intracellular signaling scaffold. Here, we used platelets from mice with a megakaryocyte/platelet-specific deletion of FLNA to investigate the role of FLNA in regulating platelet shape change. Relative to controls, FLNA-null platelets exhibited defects in stress fiber formation, contractile force generation, and MLC phosphorylation in response to thrombin stimulation. Blockade of Rho kinase (ROCK) and protein kinase C (PKC) with the inhibitors Y27632 and bisindolylmaleimide (BIM), respectively, also attenuated MLC phosphorylation; our data further indicate that ROCK and PKC promote MLC phosphorylation through independent pathways. Notably, the activity of both ROCK and PKC was diminished in the FLNA-deficient platelets. We conclude that FLNA regulates thrombin-induced MLC phosphorylation and platelet contraction, in a ROCK- and PKC-dependent manner.
Enhancing semi‐supervised contrastive learning through saliency map for diabetic retinopathy grading
Authors: Zhang Jiacheng , Jin Rong , Liu Wenqiang
Published: August 2024

Diabetic retinopathy (DR) is a severe ophthalmic condition that can lead to blindness if not diagnosed and provided timely treatment. Hence, the development of efficient automated DR grading systems is crucial for early screening and treatment. Although progress has been made in DR detection using deep learning techniques, these methods still face challenges in handling the complexity of DR lesion characteristics and the nuances in grading criteria. Moreover, the performance of these algorithms is hampered by the scarcity of large‐scale, high‐quality annotated data. An innovative semi‐supervised fundus image DR grading framework is proposed, employing a saliency estimation map to bolster the model's perception of fundus structures, thereby improving the differentiation between lesions and healthy regions. By integrating semi‐supervised and contrastive learning, the model's ability to recognise inter‐class and intra‐class variations in DR grading is enhanced, allowing for precise discrimination of various lesion features. Experiments conducted on publicly available DR grading datasets, such as EyePACS and Messidor, have validated the effectiveness of our proposed method. Specifically, our approach outperforms the state of the art on the kappa metric by 0.8% on the full EyePACS dataset and by 3.2% on a 10% subset of EyePACS, demonstrating its superiority over previous methodologies. The authors’ code is publicly available at https://github.com/500ZhangJC/SCL‐SEM‐framework‐for‐DR‐Grading.
Multi‐objective multiperiod stable environmental economic power dispatch considering probabilistic wind and solar PV generation
Authors: Ali Aamir , Aslam Sumbal , Mirsaeidi Sohrab , Mugheri Noor Hussain , Memon Riaz Hussain , Abbas Ghulam , Alnuman Hammad
Published: August 2024

The economic‐environmental power dispatch (EEPD) problem, a widely studied bi‐objective non‐linear optimization challenge in power systems, traditionally focuses on the economic dispatch of thermal generators without considering network security constraints. However, environmental sustainability necessitates reducing emissions and increasing the penetration of renewable energy sources (RES) into the electrical grid. The integration of high levels of RES, such as wind and solar PV, introduces stability issues due to their uncertain and intermittent nature. This article addresses these concerns by formulating and solving the economic environmental and stable power dispatch (EESPD) problem, which includes fixed zonal reserve capacity from conventional thermal generators and uncertain reserves from RES. Uncertainties in RES and load demand are modelled using random variable generation techniques, applying Gaussian, Weibull, and log‐normal probability density functions (PDFs) for load demand, wind velocity, and solar irradiance, respectively. The stochastic EESPD problem extends to multiple periods by replicating the single‐period problem for each interval in the planning horizon, linking periods through intertemporal ramping costs, physical ramp rate, and fixed zonal reserve constraints on dispatch variables. Multi‐objective evolutionary algorithms (MOEAs) have gained prominence for solving complex non‐linear problems involving multi‐objective functions. This article applies the latest MOEAs to tackle the proposed EESPD problem, incorporating stochastic wind and solar PV power sources. Network security constraints, such as transmission line capacities and bus voltage limits, are considered along with constraints on generator capabilities and intertemporal spinning reserves, ramp‐up and ramp‐down constraints for thermal generators. A bidirectional coevolutionary‐based multi‐objective evolutionary algorithm is employed, integrating an advanced constraint‐handling technique to ensure compliance with system constraints. The simulation results show that the proposed formulation achieves a better trade‐off between various conflicting objective functions compared to other state‐of‐the‐art MOEAs.
Research on the influence of pulse current parameters on the tooth filling during current-assisted splitting spinning of small module tooth-shaped part
Authors: Xia Qinxiang , Zhou Haoyang , Xiao Gangfeng , Chen Can
Published: August 2024

Current parameters are the main factors influencing the tooth filling of small module tooth-shaped parts (SMTSPs) with characteristics of hollow, thin wall-thickness made of difficult-to-deform metal during current-assisted splitting spinning (CASS). A coupled electrical-thermal-mechanical finite element analysis (FEA) model was established based on the ABAQUS software, and the influence of pulse current parameters, such as current density and duty ratio, on the tooth saturation was investigated. The results show that the tooth saturation increases obviously under pulse current comparing without pulse current, and increases rapidly with the increasing of the current density and duty ratio, but the tooth saturation tends to reach a threshold value when the current density greater than 13.5 A/mm2 and the duty ratio greater than 20%. The relative error of the tooth saturation between simulation and experimental result is less than 2%, which indicates that the established CASS FEA model of SMTSPs is reasonable.
An investigation of multi-pass incremental sheet forming
Authors: Ridland Matthew , Waldram Lawrence , Qin Zhenyuan , Peng Wenxuan , Ou Hengan
Published: August 2024

This study investigates toolpath strategies of multi-pass incremental sheet forming (MSPIF) including a combination of an IN (I) pass where the tool moves inwards and downwards and an OUT (O) pass where the tool moves outward and upward. MSPIF processes (III, IIO, IOI and IOO) were investigated to form cone and dome shapes using experimental testing and finite element (FE) simulation. It was found that any IN pass after the initial IN pass, produced stepped features due to Rigid Body Translation (RBT) of the formed part, with the magnitude of the step being dependent on the both the quantity and position of the IN passes. The IOO strategy was more effective in producing a flat bottom cup (no stepped features), but due to the succession of OUT passes used, sheet thinning occurred near the centre of the formed part. A 4-stage IOOO strategy successfully increased the final maximum draw angle by 23% relative to the maximum wall angle of a single pass. The results have shown that the MSPIF approach can be used as an effective means to improve the formability in incremental sheet forming.
An Algorithmic Framework for Optimizing Submerged Arc Additive Manufacturing Process Parameters for User-Specified Bead Width
Authors: Goala Suraj , Joshi Shrikrishna N.
Published: August 2024

Submerged Arc Additive Manufacturing (SAAM) is a process known for its high material deposition characteristics, and since it is based on Submerged Arc Welding (SAW), it is expected to obtain thicker material depositions. In this work, an algorithmic framework has been developed which helps product designers or the user by taking their expectations of the bead width according to their requirement, and the algorithm suggests the optimal input process parameters which would help obtain an optimal bead width and optimal use of energy, minimizing the need for post-processing. The framework incorporates penetration depth, a critical factor for proper interlayer fusion. The framework was compared with a Genetic Algorithm (GA) output with similar GA parameters for a single run to evaluate its effectiveness. The proposed framework achieves a 93.7% accuracy in bead width prediction and a 27.5% reduction in energy input per unit length compared to the GA. This user-friendly tool empowers novice SAAM users and manufacturers to optimize deposition and energy efficiency.
An analytical review on interfacial reactions in high-temperature die-attach: The insights into the effect of surface metallization and filler materials
Authors: Liu Canyu , Liu Changqing
Published: August 2024

This review aims for a comprehensive insight into the interfacial reactions and the effects of surface metallization in high temperature die-attach, which is critical in governing the reliability of resultant interconnects of power electronic modules. With the emerging high-temperature filler materials, the interfacial interactions and microstructural evolutions exhibit various distinctive features, which demands detailed examination in order to identify suitable surface finishes. The metallization is not always beneficial to improving the quality and reliability of the interconnects, and consideration should also be given to the cost-effectiveness and manufacturability. The intermetallic compounds (IMCs) formed during interfacial reactions are of prime concerns for an extended discussion, together with the formation of solid solution at interfaces which can also be an important topic to explore. In this work, five commonly-encountered high temperature solder fillers are examined, including high-Pb, Au-based, Bi-Ag, Zn-Al solders and nano Ag paste, the emphasises are put on the interactions with different metallized surfaces in die-attach. The effects of metallization on interfacial reactions and formation of interfaces are discussed. Finally, the recommendations of suitable metallization are outlined to enable cost-effective and reliable interconnects for the related applications.
Forming limit of hot-rolled high-strength steels considering sheet thickness effect
Authors: Zhang Shi-Hong , Chen Wei-Jin , Chen Shuai-Feng , Song Hong-Wu , Deng Si-Ying
Published: August 2024

The forming limit curve (FLC) has been commonly used tool to predict the metal forming cracking in engineering. Whereas, based on the assumption of plane stress state, the formability prediction of thick sheet of hot-rolled high-strength steels is quite different from the experimental measurement. Finite element simulation was used to study the effect of sheet thickness. It is found that extra stress along thickness is introduced between inside and outside the instability region, which become larger increased. Additionally, the visco-plastic self-consistent (VPSC) model and the M-K model are combined to establish the VPSC-MK model for investigating the influence of thickness difference. With reasonable capture of thickness stress, accurate prediction of FLC under different sheet thickness of hot rolled high-strength steel (HR-HSS) is well realized via VPSC-MK model. That is, it is revealed that the sheet thickness effect for HR-HSS mainly origins from normal stress induced during necking process.
The effect of different C contents on the microstructure evolution and mechanical properties of Ti45Al6Nb alloy
Authors: Fang Hongze , Li Kexuan , Zhou Lingyan , Liang Jiangshan , Yang Xiaokang , Chen Ruirun
Published: August 2024

The content of C element and in-situ Ti2AlC phase is adjusted to reduce the content of B2 phase in the TiAl matrix, ultimately improving the compressive properties of TiAl alloys. Results show that there is a high content of B2 phase inside the lamellar colony, and the Nb content in the B2 phase is higher than that dissolved in matrix. The addition of C element results in the formation of a round rod like reinforcing phase and refining the lamellar colony. As the C content increases from 0 to 3.0 at. %, the content of in-situ Ti2AlC reinforcing phase increases from 0 to 17.8 vol. %, the content of B2 phase decreases from 10.4 to 1.4 vol. %, and the size of the lamellar colony decreases from 161.3 to 19.5 μm. The decrease in the content of B2 phase is due to the preferential formation of Ti2AlC reinforcing phase in the liquid, Nb will preferentially dissolve in it, resulting in a more uniform distribution of Nb in the solidified structure and reducing the segregation of Nb. Then, Ti2AlC particles act as heterogeneous nucleation, increasing the nucleation sites in the alloy melt and refining the microstructure. According to the results of the compression test, as the C content increases from 0 to 2.5 at. %, the compressive strength increases from 1186.9 to 2154.5 MPa, and the compressive strain increases from 6.5 to 20.2 %. Therefore, the precipitation strengthening effect of Ti2AlC, the grain boundary strengthening effect of refined microstructure, and the decrease in the content of B2 phase jointly contribute to the improvement of the compressive properties at room temperature.
Cryo-compression and annealing hardening of 7075 aluminum alloy
Authors: Sun Hongfei , Zhang Yifan
Published: August 2024

7075 aluminum alloy, as a lightweight, high-strength, and corrosion-resistant structural material, is widely used in the aviation industry. Because 7075 aluminum alloy is commonly used in structural components, its plastic processing ability is highly required by the usage environment. Recent studies have shown that 7075 aluminum alloy exhibits better deformation ability under low temperature conditions. In this paper Cryo-compression experiments on 7075 aluminum alloy under different compression rates (0.001 s-1-0.5 s-1) in a low-temperature environment (soaked in liquid nitrogen for 30 minutes) has been discussed. Annealing process research was conducted on the low-temperature compressed samples, and the optimal annealing process parameters (400Co, insulation for 15 minutes) and optimal deformation amount (16%) were obtained through comparison of microstructure and properties. And it was found that 7075 aluminum alloy exhibited annealing hardening phenomenon when annealed at 250 Co, and the reason was the diffusion segregation of solid solution elements formed during low-temperature forming, which led to the precipitation of the second phase MgZn2 during low-temperature annealing.
A review and framework on the aesthetic design of wearable exoskeleton
Authors: Li Zhi , Wu Hao , Chen Shan , Yu Zhiyuan , Mao Xinyi
Published: August 2024

Since the first documented modern wearable exoskeleton appeared, the development of wearable exoskeleton could be summarized as three stages: germination, exploration, and innovation. This paper has 5 sections. Section 1 briefly introduces the research background of the modern wearable exoskeleton. Section 2 reviews the classical design cases since the emerging of the concepts of wearable exoskeleton. Section 3 provides a detailed integration of the theory developments on the design methodology of the wearable exoskeleton. Section 4 illustrates a framework of the aesthetic design of wearable exoskeleton by combining Total Design methodology (as a design framework core), QFD, TRIZ and Product Semantics. Section 5 gives a conclusion on the discussion of the design framework as well as the future work.
Smart Cities enhancing the lives of people with disabilities
Authors: Pearson Stephen Robert , Shafik Mahmoud
Published: August 2024

Smart cities hold great promise for revolutionising urban living, but their potential to improve the lives of people with disabilities remains underexplored. This paper investigates the challenges faced by individuals with disabilities in everyday urban environments and explores how smart technology can mitigate these challenges. By leveraging data-driven insights, connectivity, and innovative solutions, smart cities can create more inclusive environments that enhance accessibility, mobility, and overall quality of life for people with disabilities. This paper discusses the various issues encountered by individuals with disabilities in towns and cities and proposes strategies for utilising smart technology to address these challenges effectively.
I4.0/5.0 MR training: Investigating MR tools to enhance learning experiences
Authors: Bondin Andrea , Zammit Joseph Paul
Published: August 2024

As the manufacturing industry continues its shift towards highly complex Industry 4.0 production environments, there is an expected exponential increase and change in the demanded skills and qualifications among employees. However, traditional teaching methods may pose challenges when it comes to applying learned skills in real-life engineering situations, given the complexity of these environments. Recent advancements in technologies enabling virtual co-existence have opened up new opportunities for personalised and immersive services in pedagogy. While Mixed Reality (MR) and, more significantly, Metaverse infrastructure are still in their early stages, researchers and educators have the opportunity to lead the exploration of new avenues for reskilling educators and enhancing student learning experiences. This paper presents research conducted at the University of Malta, focusing on exploring the potential transformative pedagogical effects of MR in specialised Industry 4.0/5.0 engineering training. The paper proposes a framework for developing a Virtual Learning Factory (VLF) using MR technology, grounded in established and effective learning methodologies. The envisioned VLF aims to create an immersive experiential learning environment where engineering students can better adapt to the evolving industrial landscape, preparing them to excel in the dynamic era of advanced manufacturing. Additionally, the research delves into the potential impacts of MR-based training on enhancing training precision and efficiency.
Benchtop-AFP: An Exploration of Democratised Automated Fibre Placement
Authors: McArthur Stig , Mehnen Jörn , Bomphray Iain
Published: August 2024

This paper outlines the creation and evaluation of Benchtop-AFP, an innovative approach to producing composite materials akin to Automated Fibre Placement (AFP) but without the high capital expenses typical of traditional AFP methods. This unique technique, with further refinement, could serve as a valuable tool for research and development in automated fibre placement. As a world first, it aims to democratise AFP research, particularly for institutions where access to full-scale AFP facilities is unavailable and limited due to financial, skills, or safety constraints. This article presents the new method and provides examples of samples generated using this technique.
Decoding the diverse landscape of manufacturing execution systems
Authors: Brooks Sam , McFarlane Duncan
Published: August 2024

Manufacturing Execution Systems (MES) are a key software tool used by manufacturers to plan, coordinate and monitor operations. Due to the high integration cost, customisation required, and the impact on operations, choosing an appropriate MES is vital. This study aims to assist in selecting MES by evaluating data and key functions of existing commercial MES. The study reviewed and classified 20 MES based on their functions and their functions and function position in the automation pyramid. The publicly available application program interfaces (APIs) of six MES were further evaluated to identify 58 key data types available from MES. A final evaluation highlighted 15 data types that can address common manufacturing challenges. Worker capabilities were highlighted as the most useful data type from MES to address common challenges; however, labour management functions are often missing from MES. A wide range of available core MES functions and data types were noted in commercial MES; this should be carefully considered when choosing a commercial MES.
An effective MLP model for detecting malicious nodes in PoS permissionless blockchains
Authors: Anthony Njoku ThankGod , Shafik Mahmoud , Atlam Hany F.
Published: August 2024

With the proliferation of blockchain technology, ensuring the security and integrity of permissionless Proof-of-Stake (PoS) blockchain networks has become imperative. This paper addresses the persistent need for an effective system to detect and mitigate malicious nodes in such environments. Leveraging Deep Learning (DL) techniques, specifically Multi-Layer Perceptron (MLP), a novel model is proposed for real-time identification and detection of malicious nodes in PoS blockchain networks. The model integrates components for data collection, feature extraction, and model training using MLP. The proposed model is trained on labelled data representing both benign and malicious node activities, utilising transaction volumes, frequencies, timestamps, and node reputation scores to identify anomalous behaviour indicative of malicious activity. The experimental results validate the efficacy of the proposed model in distinguishing between normal and malicious nodes within blockchain networks. The model demonstrates exceptional performance in classification tasks with an accuracy of 99%, precision, recall, and F1-score values hovering around 0.99 for both classes. The experimental results verify the proposed model as a dependable tool for enhancing the security and integrity of PoS blockchain networks, offering superior performance in real-time detection and mitigation of malicious activities.
Utilising Digital Twins for Smart Maintenance Planning of Fuel Cell in Electric Vehicles
Authors: Amaitik Nasser , Zhang Ming , Xu Yuchun , Clark Tony , Bastin Lucy
Published: August 2024

This paper presents a framework utilising digital twins for predictive maintenance planning of fuel cells in electric vehicles, focusing on real-time condition monitoring and Remaining Useful Lifetime (RUL) prediction. By integrating advanced algorithms, it optimises maintenance schedules to reduce downtime and extend fuel cell lifetime. Despite relying on simulated data, the findings highlight the potential of digital twins to improve fuel cell reliability, and sustainability, illustrating their transformative impact on smart urban transportation systems.
Evaluating the impact of GSCM practices on Organisational performance for SMEs in Vietnam
Authors: Saad Sameh , Khamkham Mohamed , Nguyen Quang Duong
Published: August 2024

Green Supply Chain Management (GSCM) has become one of the key strategies for enhancing enterprises and achieving sustainable improvement. This study aims to evaluate the impact of GSCM practices on the organisational performance of SMEs in Vietnam. This study considers four GSCM practices: green product development and design, green purchasing, green production management and marketing, and green logistics. Whereas the organisation performance elements are operational performance, economic performance, and environmental performance. A set of hypotheses is proposed to evaluate the impact of GSCM practices on organisational performance. A questionnaire survey is used to validate the GSCM practices and performance outcomes. One hundred twenty participants completed the questionnaire and data is collected from the available SMEs and used in the empirical analysis. Multi-linear regression analysis tests the proposed hypotheses and identifies the research outcomes. The results revealed that green practices led to improvement in all elements of organisational performance. However, Green Logistics is the only one that does not positively impact the economy and environmental performance due to inappropriate implementation of the green logistics. The paper provides a clear understanding of various aspects of GSCM implementation and can help practitioners improve their GSCM performance.
Finite element analysis of drilling-induced damage responses on FRP hybrid bio/composite laminates
Authors: Ismail Sikiru O. , Chandru Harshith
Published: August 2024

Machining/drilling is crucial in the joining process of composites. However, drilling composite materials often leads to hole dimensional inaccuracy, surface roughness and delamination, among others. These drilling-induced damage (DID) responses are associated with torque and thrust (principal drilling forces), and rampant in fibre-reinforced polymeric (FRP) hybrid bio/composite laminates. Therefore, a three-dimensional (3D) numerical approach, using finite element method (FEM) was undertaken to analyse the DID responses of FRP hybrid bio/composite laminates. Drilling simulation was performed at spindle velocity and feed rate of 3000 rpm and 5 mm/s, respectively. Both thrust force and torque were produced, computed and interpreted. From the results obtained, it was evident that drilling of synthetic (glass, G and carbon, C) FRP hybrid composites demanded higher or substantial torque and thrust forces, due to their superior strengths, exemplified by the (2G+2F)13 samples, when compared with the weaker natural/plant (flax, F; jute, J and hemp, H) FRP hybrid bio/composites, especially (J+F)27 samples. In addition, the investigation established the advantages of dual layup methods over single arrangements. Carbon and glass FRP hybrid composites exhibited excellent hybridisation properties, but their brittleness necessitated careful management of torque and thrust forces to prevent high DID responses. Summarily, this investigation provided a guide for FRP hybrid bio/composites design and drilling, in addition to opportunities for additional research on other process parameters towards further study.
Twinning the future: Implementing digital twin technology in the optimisation of fibre-reinforced polymers
Authors: Alajmi Abdalrahman
Published: August 2024

Optimisation of fibre-reinforced polymers (FRPs) is critical for engineering a sustainable future. This review paper explores the potential of digital twins (DTs) in enhancing the characteristics, performance, and sustainability of synthetic and sustainable FRPs. DTs provide a virtual space for real-time monitoring and predictive analysis and have revolutionised the traditional limitations of FRP production. Recent case studies, like the FASTIGUE project and advances in fibre-reinforced thermoplastics, showcase the DT’s powerful role in addressing issues during production. The paper also discusses the unique challenges of developing sustainable “green” composites that balance performance with biodegradability to meet the Sustainable Development Goals. It highlights the benefits of utilising DTs to scrutinise the manufacturing processes of both synthetic and natural FRPs. Modern DTs have demonstrated the capacity to optimise the curing kinetics and mechanical properties of these materials. Furthermore, case studies such as the 3D-printed continuous carbon fibre composites, overmoulded fibre-reinforced thermoplastics, and recyclable Elium®-based composites authenticate the capabilities of DTs in enhancing the sustainable manufacturing of FRPs. Acknowledging future challenges, the paper recommends integrating production and sustainability metrics into modern multi-tier DT systems for holistic benefits.
DSIL4IMR: A dual step-based initial localization method for industrial mobile robot
Authors: Li Wenguang , Ou Jishun , Ren Jiying , Huang Panling , Fang Haibo , Han Lu , Zhou Jiehan , Zhou Jun
Published: August 2024

This paper introduces a dual-step based initial localization method for industrial mobile robots (DSIL4IMR) that operates without user intervention at start-up. Utilizing a differential chassis equipped with a radar sensor, the method combines feature extraction and spatial information matching steps to locate the robot’s initial position. A unique metric, degree of stability, is developed to identify a feature map whether it is a dynamic or erroneous feature. DSIL4IMR does not require artificial landmarks and outperforms existing WiFi fingerprinting and map filter methods in both accuracy and efficiency. DSIL4IMR triples the localization efficiency compared to traditional approaches while achieving centimetre-level precision.