139585 research outputs found
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Harvesting or nurturing? Corporate venture capital and startup green innovation
No full textPublisher Copyright: © 2025 The AuthorsCorporate venture capital (CVC) investors now regularly back startups engaged in green innovation, yet their motivations and the causal impact of their investments on startups' green innovation remain unclear. We examine heterogeneous CVC selection and treatment effects on venture green innovation, conditional on corporate parents' green complementary resources. We draw on institutional logics to theorize CVCs as a group, and resource complementarity arguments to explain differences among CVC investors. Utilizing unique matched investment and patenting data (2000–2021) for ventures from 27 European countries funded by VCs during 2004–2019, we employ difference-in-differences models to separate treatment from selection effects and to test the heterogeneity of the treatment effects. We find that CVC investors preferentially select ventures exhibiting higher pre-investment green innovation, an effect driven by those whose parent corporations actively engage in green innovation themselves, indicating substantive rather than symbolic motives behind these investments. Critically, post-investment nurturing of green innovation depends on investor heterogeneity: only CVC investors whose parent corporations possess complementary green innovation resources significantly increase their portfolio ventures' subsequent green innovation.Peer reviewe
Mechanical behaviors and meso analysis of asphalt mixtures under moisture damage induced by hydrodynamic impacts
No full textPublisher Copyright: © 2024 Elsevier LtdMoisture damage significantly affects the performance and integrity of asphalt pavement. The water immersion method commonly used in laboratory is considered as a static water intrusion technique to simulate the moisture damage on asphalt mixtures. However, field conditions mainly involve dynamic water impacting due to moving tires and pressurized pore water. In this study, the in-situ moisture damage induced by repeated traffics was recurred with the Moisture Induced Sensitivity Tester (MIST), and their mechanisms and impacts on the void structure, viscoelastic properties, and fracture performance of the asphalt mixture were assessed. The findings revealed that hydrodynamic impacts with various loading cycle (0, 2000, 4000, 6000 cycles) could lead to an increase in the porosity of the mixture, with isolated voids eventually merged under water intrusion and erosion. The growth rate of the connected voids was more drastic in the initial stage and gradually decreased with the increased loading cycle. Besides, the dynamic water damage could enlarge the overall permeability of the asphalt mixtures and aggrandize the complexity of the water flow paths in a non-linear manner. The dynamic water damage factor (Dm) reflecting the variation of porosity was introduced to characterize the damage severity of the mixture. The results indicated that a severer damage was normally observed for the mixture with a higher initial porosity. Furthermore, significant effects of hydrodynamic damage on the dynamic modulus of the asphalt mixtures, especially in the high temperature (low frequency) domain, were also observed on the MIST-conditioned specimens. The CT-scanning analysis implied that the impaired adhesion between asphalt and aggregates and mechanical damage from pore water pressures were the primary causes of the damage. A degradation in crack resistance is observed from the Semi-Circular Bending (SCB) tests considering the hydrodynamic damage at various MIST-conditioning cycle.Peer reviewe
Nature-based flame-retardant finish for cotton fabric using Banana pseudostem saps
No full textThis study investigated the potential of eco-friendly substances, namely Banana pseudostem sap (BPS) and phytic acid (PA), to enhance the flame-retardant properties of cotton fabric. The process involved applying various concentrations of BPS (100%, 200%, 300% and 400%) to pre-mordanted scoured-bleached cotton fabric. The treated fabrics were then analyzed for vertical flammability and LOI (limiting oxygen index). Results revealed that fabrics treated with a 400% concentration of BPS showed exceptional flame-retardant properties, with an LOI of 27.5%, compared to the control fabric, which had an LOI of 18.3%, representing a significant increase of 1.5 times. In the vertical flammability test, the BPS-treated fabric burned briefly and self-extinguished. In contrast, the control fabric exhibited sustained burning, with the treated fabric burning nearly 5 times slower, propagating at 26.5 mm/min. SEM images showed the deposition of flame-retardant finishes on the fabric surfaces. FTIR and EDX were employed to identify chemical entities in the fabric. Importantly, post-treatment evaluation of tensile strength and breaking elongation indicated no significant changes in the cotton fabrics, reassuring the quality of the fabric. These findings highlighted the potential utility of BPS and phytic acid as effective flame-retardant agents for cotton fabrics, offering promising avenues for sustainable textile manufacturing.Peer reviewe
Experimental study on shear mechanism of a new TU-type connector at HSS-UHPC interface
No full textPublisher Copyright: © 2024 Elsevier LtdTo maximize the benefits of high-strength steel (HSS) and ultra-high performance concrete (UHPC) composite structures, proper connections at HSS-UHPC interfaces are essential. Due to the significant variations in material strengths and component dimensions, traditional shear connectors could be unsuitable for HSS-UHPC interfaces. This study proposes a new TU-type connector (T-shaped rib with U-shaped holes), which has the advantages of high shear and tensile capacity, good slip capacity, low height limitation, and easy installation. Firstly, eighteen push-out tests of HSS TU-type connectors embedded in UHPC were performed to investigate the effect of connector heights and the contribution of connector flanges. The failure process, including the yielding of hole walls, the fracture of connector webs, and the development of fracture surfaces was discussed. Besides, the microstructures involving smooth areas, lamellar structures, and dimples on the fracture surfaces were presented by scanning electron microscope (SEM), and the effect of flange foam blocks on the out-of-plane displacements of UHPC slabs was investigated by digital image correlation (DIC). Secondly, the shear force–displacement curves and the load–strain relations of steel plates and rebars were discussed. In addition, the effects of considered parameters on shear capacity, peak slips, and shear stiffness were investigated. Finally, a strut-and-tie model was established to reveal the shear mechanism of TU-type connectors. Based on the principle of virtual work, the shear capacity equations of TU-type connectors were proposed.Peer reviewe
Matrix-weighted Besov-type and Triebel–Lizorkin-type spaces I : Ap-dimensions of matrix weights and φ-transform characterizations
No full textPublisher Copyright: © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2025.Let s∈R, q∈(0,∞], and τ∈[0,∞). It is well known that Besov-type spaces B˙p,qs,τ with p∈(0,∞] and Triebel–Lizorkin-type spaces F˙p,qs,τ with p∈(0,∞) when τ∈[0,∞) or with p∈(0,∞] when τ=0 on Rn consist of a general family of function spaces that cover not only the well-known Besov and Triebel–Lizorkin spaces B˙p,qs and F˙p,qs (when τ=0) but also several other function spaces of interest, such as Morrey spaces and Q spaces. In three successive articles, the authors develop a complete real-variable theory of matrix-weighted Besov-type spaces B˙p,qs,τ(W) and matrix-weighted Triebel–Lizorkin-type spaces F˙p,qs,τ(W) on Rn, where W is a matrix-valued Muckenhoupt Ap weight. This article is the first one, whose main novelty exists in that the authors introduce the new concept, Ap-dimensions of matrix weights, and intensively study their properties, especially those elaborate properties expressed via reducing operators. The authors then introduce the spaces B˙p,qs,τ(W) and F˙p,qs,τ(W) and, using Ap-dimensions and their nice properties, the authors establish the φ-transform characterization of B˙p,qs,τ(W) and F˙p,qs,τ(W). The Ap-dimensions of matrix weights and their properties also enable the authors to obtain the sharp boundedness of almost diagonal operators on related sequence spaces in the subsequent second article and the optimal characterizations of molecules and wavelets, trace theorems, and the optimal boundedness of pseudo-differential operators and Calderón–Zygmund operators in the subsequent third article.Peer reviewe
A game-based decision-making method for multi-ship collaborative collision avoidance reflecting risk attitudes in open waters
No full textPublisher Copyright: © 2024 Elsevier LtdTo accurately reflect risk attitudes towards ship intentions in multi-ship encounters, this paper develops a novel two-stage collaborative collision avoidance decision-making (CADM) model by incorporating intention prediction and real-time decision-making. We acquire prior knowledge of risk attitudes by analyzing Automatic Identification System (AIS) data and further estimate the probability distributions of encountering ship's risk attitude using Bayesian reasoning. By treating collision avoidance procedure as a static game with incomplete information, a predictive model for collision avoidance intentions is developed by taking account into risk attitude probabilities. Real-time decisions are then implemented according to different stages, and a collaborative CADM model is established by a game-decision cycle. Finally, a multi-ship encounter scenario is simulated under all combinations of risk attitudes, and the results are compared with those obtained under complete information. The results demonstrate that the proposed model can formulate avoidance actions that meet safety requirements under all combinations of risk attitudes. Further comparison with complete information proves the effectiveness of the risk attitude probability model, which is conducive to improving the decision-making flexibility and reducing complexity. The research findings enhance the collaborative decision-making, contributing to the development of autonomous navigation in open waters.Peer reviewe
Reconciliation Through Digital Textiles
No full textPublisher Copyright: © 2025 selection and editorial matter, Rachel Charlotte Smith, Daria Loi, Heike Winschiers-Theophihis, Liesbeth Huybrechts and Jesper Simonsen.This chapter provides a critical reflection on the geopolitics of knowledge mobilisation within an interdisciplinary research project called Mending the New – Reconciliation through digital textiles, which was carried out by a consortium of researchers from Colombia and the United Kingdom working together with four women’s textiles collectives located in different rural areas of Colombia (Bojayá, Quibdó, Mampuján, and Sonsón). This project aimed to generate meeting points and connections between these collectives to understand their use of textiles as a language of memory and care of life during wartime. Through the research, the team used Participatory Design (PD) methods to explore this collective and material mode of documenting and narrating the conflict through textile making and introduced digital technologies as a strategy for engaging the participants in unusual material dialogues; this, in turn, triggered challenging conversations about war and reconciliation from new perspectives. This case presents rich information on the role of Participatory Design in reconciliation, peace, and armed conflict contexts; however, constituting the focus of this chapter, the specific setting of this project shaped and sustained research design work in such a way that geopolitics of knowledge practices considerably marked participation. Awareness of the politics of knowledge production and mobilisation within Global North–Global South research collaborations brings a set of critical challenges that, while not necessarily new to Participatory Design, reconfigure what counts as participation, who participates, and how.Peer reviewe
Extracting valuable metals from zinc sulfide concentrate: A comprehensive simulation-based life cycle assessment study of oxidative pressure leaching
No full textPublisher Copyright: © 2024 Elsevier LtdConsidering the increasing environmental consciousness and the imperative for sustainable development, conventional zinc smelting operations employing the roast-leaching-electrowinning process face growing environmental pressures. Consequently, the oxidative pressure leaching process has emerged as an alternative processing route. This study focuses on recovery of major metals from ZnS concentrate, building a comprehensive model to simulate the oxidative pressure leaching process. The process model built demonstrated that zinc, sulfur, indium, gallium, cadmium, cobalt, germanium, and copper could be recovered effectively, the main chemical inputs being sulfuric acid, oxygen, and lime, while zinc electrowinning constituting over 90 % of the total electricity consumption. The results were used to compile a life cycle inventory, culminating in a gate-to-gate assessment of the environmental impacts of the process. The global warming potential for the treatment of 1 t of ZnS concentrate is approximately 2,000 kg CO2 eq. The primary environmental impacts in the process are from chemical inputs and electricity consumption. Based on these findings, recommendations for sustainable production practices are proposed. These include systematic recovery and reuse of electrolytic off-gas and roasting heat, greater utilization of renewable energy, enhanced iron removal processes, and exploration of alternative chemicals for Ga and Ge recovery.Peer reviewe
Vertically Stacked Boron Nitride/Graphene Heterostructure for Tunable Antiresonant Hollow-Core Fiber
No full textIncorporating atomically thin two-dimensional (2D) materials with optical fibers expands their potential for optoelectronic applications. Recent advancements in chemical vapor deposition have enabled the batch production of these hybrid fibers, paving the way for practical implementation. However, their functionality remains constrained by the integration of a single 2D material, restricting their versatile performance. Here, we introduce a boron nitride/graphene (BN/Gr) heterostructure in the antiresonant hollow-core fiber (ARF) to modulate its optical resonance and thus enhance graphene nonlinearity by controlling the BN thickness. Hydroxyl-rich methanol is employed to improve the flatness and crystallinity of graphene, promoting the vertical epitaxy of BN with a controllable thickness ranging from 5 to 50 nm. The engineered optical resonance notably tunes the light-graphene interaction within the BN/Gr-ARF, increasing the depth of nonlinear optical modulation from 4% to 10% and enhancing all-optical modulation performance by 75%. Our methodology opens possibilities for tunable optical waveguides via the direct growth of functional 2D material-based heterostructures, offering a robust platform for the development of highly integrated photonic devices.Peer reviewe
Modeling thermal effects in atomic layer deposition for trench-shaped structures
No full textPublisher Copyright: © 2025 The Author(s)An atomic layer deposition (ALD) simulation approach is presented for transient diffusion of heat and mass at low Knudsen numbers (Kn<0.1), focusing on thermal effects in trench-shaped structures. Two boundary conditions (BCs) are analyzed: the ‘thin wall’ BC incorporates exothermic reactions with a derived wall heat flux term, and the ‘thick wall’ BC maintains constant wall temperature ranging between 500 K and 800 K. For both BCs, we examine aspect ratios from 1 to 100. The chosen BC significantly impacts reaction kinetics/peak temperatures, with local temperature variations up to 200 K under ‘thin wall’ conditions. The coating time ratio between ‘thin wall’ and ‘thick wall’ ranges from 0.9 to 1.7. Two ‘universal’ functional forms are proposed to explain how surface coverage depends on time and how coating time relates to aspect ratio and diffusion timescale. Results emphasize the crucial role of temperature distribution in ALD, impacting growth per cycle, reactant decomposition/desorption, and potential substrate damage.Peer reviewe