Comparing the chatter characteristic in milling of Ti6Al4V alloy with and without laser assistance

Laser-assisted machining (LAM) is a promising technique to enhance the machinability of difficult-to-cut materials. However, many challenges remain for its practical engineering application, despite extensive research on the material removal mechanism in LAM. One key challenge is to elucidate how the laser affects the machining dynamics (e.g. cutting forces and chatter characteristics) and machined qualities in realistic machining scenarios. Therefore, this study aims to investigate the relationship between chatter characteristics and laser assistance in milling processes. Two sets of milling experiments with different depths of cut were conducted on wedge-shaped Ti6Al4V alloys with and without laser assistance. The milling forces were measured and analyzed using Short-time Fourier transforms and Wavelet transforms to detect chatter in frequency and time-frequency domains. Moreover, four indicators (i.e., standard deviation, Kurtosis, fuzzy entropy, envelope entropy) were extracted to monitor the milling conditions. The results showed that dry milling experienced a transition from stable machining to slight chatter at an axial depth of cut (ADOC) of 1.75 µm and then to severe chatter at ADOC=4.63 µm under the same cutting parameters, while LAM only exhibited slight chatter at ADOC=4.00 µm, demonstrating the specific effect of laser assistance on suppressing chatter. This was further confirmed by the observed surface morphology and roughness

Scotland’s Assets for Epidemic Preparedness : Workshop at the University of Strathclyde

MOSAEC (Mobilising Scotland's Assets in equitable ways for Epidemic Control) seeks to develop interdisciplinary research ideas and teams that will ensure we are better prepared for future epidemics. The focus of this workshop was on Scotland’s assets and how these can be used to improve epidemic preparedness and reduce inequalities. A series of presentations provided context for the diverse assets employed in epidemic response with discussions around previous use of assets, opportunities to employ other assets and the steps needed to operationalise key assets

UK APAP R-matrix electron-impact excitation cross-sections for modelling laboratory and astrophysical plasma

Systematic R-matrix calculations of electron-impact excitation for ions of astrophysical interest have been performed since 2007 for many iso-electronic sequences as part of the UK Atomic Process for Astrophysical Plasma (APAP) network. Rate coefficients for Maxwellian electron distributions have been provided and used extensively in the literature and many databases for astrophysics. Here, we provide averaged collision strengths to be used to model plasma where electrons are non-Maxwellian, which often occurs in laboratory and astrophysical plasma. We also provide many new Maxwellian-averaged collision strengths, which include important corrections to the published values. Recently, we made available the H- and He-like collision strengths. Here, we provide data for ions of the Li-, Be-, B-, C-, N-, O-, Ne-, Na-, and Mg-like sequences

Absolute rate coefficients for dielectronic recombination of sodium-like iron ions : experiment and theory

Absolute dielectronic recombination (DR) rate coefficients for sodium-like Fe15+ forming magnesium-like Fe14+ have been measured using the electron–ion merged-beams technique at the heavy ion storage ring Main Cooler Storage Ring, Lanzhou. The measured DR rate coefficients in the energy range from 0 to 90 eV cover all of the DR resonances due to 3s → 3p and 3s → 3d (Δn = 0) transitions and part of the DR resonances from 3s → 4ℓ (Δn = 1) core excitation. The experimental results are compared with theoretical calculations by using three independent state-of-the-art perturbative techniques: a multiconfiguration Breit–Pauli method using the AUTOSTRUCTURE code, a relativistic configuration interaction method using the Flexible Atomic Code and a multiconfiguration Dirac–Fock method using the Jena Atomic Calculator codes. Our theoretical results show excellent agreement with the experimental data in the energy range of 0–40 eV. However, in the energy range of 40–90 eV, a discrepancy is observed between the experiment and theory. Furthermore, temperature-dependent plasma recombination rate coefficients are derived from the measured DR rate coefficients over the temperature range of 103–108 K and are compared with previously available results in the literature. Within the temperature ranges relevant to photoionized plasmas and collisionally ionized plasmas, our results show good agreement with the experimental result from S. Schippers et al. (2010), as well as with the theoretical data of M. F. Gu (2004) and Z. Altun et al.; however, the earlier theoretical data from M. Arnaud & J. Raymond and P. Mazzotta et al., which are based on LS-coupling calculations, significantly underestimate the plasma rate coefficients in the low-temperature range. The present results provide a benchmark data set for astrophysical modeling

Enhanced interfacial thermal transport in diamond nanothread reinforced polymer nanocomposites : insights from atomistic simulations and density functional theory

Diamond nanothreads (DNTs), a novel class of nanomaterials that outperform traditional carbon-based nanomaterials, are exceptional reinforcers for advanced polymer composites and hold great promise in various applications of composites. In this atomistic simulation study, the novelty lies in the comprehensive exploration of DNT–polymer interfacial thermal conductance and the identification of methyl functionalization as a superior strategy, with clear implications for designing advanced thermal management composites. It is found that DNTs, derived from surface modifications (i.e. hydrogenation and functionalization) of carbon nanotubes (CNTs) with a chirality of (3, 0), demonstrate significantly enhanced interfacial thermal conductance in nanocomposite systems compared to unmodified CNTs. In particular, the incorporation of DNT_C-CH3 achieves the highest interfacial thermal conductance of 0.115 GW m−2 K−1, signifying a 140% improvement over CNTs. Through analyzing the phonon density of states (PDOS) of different reinforcements and a paraffin wax matrix, it is revealed that the low-frequency (0–70 THz) phonons dominate the interfacial thermal conductance due to their more significant contribution compared to the high-frequency (70–120 THz) phonons. Among all interfacial material combinations, DNT_C-CH3/paraffin wax exhibits the best matching in terms of the PDOS overlap, the PDOS peak intensity and the PDOS peak position in the low-frequency regime, which facilitates the most effective phonon transport across the interface and thereby leads to significant enhancement in interfacial thermal conductance. Furthermore, density functional theory (DFT) calculations uncover the optimal molecular electrostatic potential distribution and the highest binding energy of DNT_C-CH3/paraffin wax molecular structures, indicating excellent interfacial compatibility and strong adhesion between the reinforcement and the matrix material, which plays an important role in enhancing the interfacial thermal conductance. The findings of this study not only deepen the understanding of the physical mechanisms governing interfacial thermal conductance but also highlight the great potential of DNT reinforced composites in advanced thermal management applications

Semantic gaussian splatting-enhanced facility management within the framework of IFC-graph

The indoor environment of as-built structures undergo modifications over time, deviating from their original design and complicating facility management. Existing methods struggle to produce high-fidelity 3D models to represent that change. Gaussian splatting, a recent reconstruction technique, enables real-time rendering with high visual quality, offering a promising solution. This paper proposes a method that generates semantic Gaussian splats from panoramic images and integrates them into an IFC-graph for facility management. The approach enhances facility recognition and retrieval while enabling high-fidelity rendering of indoor environments. A case study demonstrates two key applications: semantic-guided facility retrieval and high-fidelity rendering, improving the semantic richness and visual quality of as-built BIM models

A visual editor for marked-up codes with auto-completion

Manual translation of codes and standards into a marked-up and computerised form is not well supported for the code experts who would be expected to undertake this task. This research examines development of a visual LegalRuleML editor built with a deep learning model trained on legal clauses to automate manual translation tasks with intelligent auto-completion. Furthermore, this research aims to evaluate if visual programming languages can provide a viable and user-friendly LegalRuleML representation and whether visual auto-completion with deep learning is an effective feature to streamline the workflow when translating legal clauses. A user study identified that the implemented visual editor provided a user-friendly and intuitive interface that successfully aided users with no prior knowledge within the field in learning and applying LegalRuleML constructs more efficiently

Wall effect on the hydrodynamics of anguilliform swimming in confined space

Three-dimensional numerical simulations are conducted to investigate the wall effect in a tube, focusing on the hydrodynamic performance of anguilliform swimming. By systematically varying the gap G (the distance between the anguilliform swimmer's midline and the tube wall), wall effect on hydrodynamic forces is quantified by analyzing surface pressure distribution and vortex structures. Results indicate that when G ≥ 4.5 the hydrodynamic performance is no longer influenced by wall effect. However, for G < 4.5, the time-averaged thrust and power coefficients increase as G decreases, while the time-averaged lateral force coefficient is almost negligible. And when the gap decreases to G = 1.5, the time-averaged thrust coefficient and power coefficient increase by 25.5 % and 21.4 %, respectively. The study reveals that wall effect primarily enhances thrust by amplifying the surface pressure and intensifying vortex interactions near the wall. At smaller gaps, the flow evolves from stable double-row vortex structures as if in the unbounded domain to unsteady small-scale vortices. These findings provide insights into hydrodynamics of the anguilliform swimmer in the confined tube and offer practical implications for the design of bio-inspired underwater vehicles and the conservation of aquatic habitats

Bridging the divide : assessing the viability of international cooperation on border carbon adjustments

International cooperation on climate change and trade is intensifying, as highlighted by numerous initiatives launched at the multilateral, plurilateral, and bilateral levels. This is an encouraging development, signaling the major role of trade policy in supporting decarbonization efforts and facilitating adaptation to climate change. Yet, at the same time, many of these initiatives eschew one of the most contested issues at the interface of trade and climate policies: Border Carbon Adjustments (BCAs). Europe’s Carbon Border Adjustment Mechanism (CBAM) is unlikely to be the last or only BCA, with various jurisdictions contemplating similar measures as they adopt increasingly ambitious climate change mitigation policies and pursue other policy objectives, such as improved national security or industrial policy. With many jurisdictions pursuing their own BCA designs and implementation strategies, however, comes an increased risk of uncoordinated proliferation of divergent approaches, which in turn can translate into greater uncertainty, higher transaction and administrative costs, and detrimental repercussions for international cooperation, including climate diplomacy. This article argues the case for international cooperation on or relating to BCAs, and assesses the prospects for such cooperation. It applies an analytical framework that examines both the “input legitimacy” and “output legitimacy” of international cooperative initiatives, focusing on three emerging models of cooperation relating to BCAs, namely the G7 Climate Club, the transatlantic talks on a Global Arrangement on Sustainable Steel and Aluminum (GASSA), and the Inclusive Forum on Carbon Mitigation Approaches (IFCMA) launched by the Organisation for Economic Co-operation and Development (OECD)

LIS Sector’s contributions to climate action : indicators for measuring success

A survey was conducted among the public and school libraries in Scotland to gather data on the different kinds of activities being undertaken for achieving and promoting sustainability, and especially Sustainable Development Goal 13 (SDG13) (climate change). These activities were mapped onto the targets and indicators of SDG13 and some targets and indicators of other SDGs that contribute to SDG13. Based on this, two simple templates are proposed for recording and reporting the activities of the library and information science (LIS) sector towards SDG13. Some simple measures for recording the outcomes and impact of some such activities are also proposed